A function in kernel/bpf/syscall.c which got a bug fix in 'net'
was moved to kernel/bpf/verifier.c in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
I noticed that reading the snapshot file when it is empty no longer gives a
status. It suppose to show the status of the snapshot buffer as well as how
to allocate and use it. For example:
># cat snapshot
# tracer: nop
#
#
# * Snapshot is allocated *
#
# Snapshot commands:
# echo 0 > snapshot : Clears and frees snapshot buffer
# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.
# Takes a snapshot of the main buffer.
# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)
# (Doesn't have to be '2' works with any number that
# is not a '0' or '1')
But instead it just showed an empty buffer:
># cat snapshot
# tracer: nop
#
# entries-in-buffer/entries-written: 0/0 #P:4
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
What happened was that it was using the ring_buffer_iter_empty() function to
see if it was empty, and if it was, it showed the status. But that function
was returning false when it was empty. The reason was that the iter header
page was on the reader page, and the reader page was empty, but so was the
buffer itself. The check only tested to see if the iter was on the commit
page, but the commit page was no longer pointing to the reader page, but as
all pages were empty, the buffer is also.
Cc: stable@vger.kernel.org
Fixes: 651e22f270 ("ring-buffer: Always reset iterator to reader page")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently the snapshot trigger enables the probe and then allocates the
snapshot. If the probe triggers before the allocation, it could cause the
snapshot to fail and turn tracing off. It's best to allocate the snapshot
buffer first, and then enable the trigger. If something goes wrong in the
enabling of the trigger, the snapshot buffer is still allocated, but it can
also be freed by the user by writting zero into the snapshot buffer file.
Also add a check of the return status of alloc_snapshot().
Cc: stable@vger.kernel.org
Fixes: 77fd5c15e3 ("tracing: Add snapshot trigger to function probes")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As nothing outside the tracing directory uses the function probes mechanism,
I'm moving the prototypes out of the include/linux/ftrace.h and into the
local kernel/trace/trace.h header. I plan on making them hook to the
trace_array structure which is local to kernel/trace, and I do not want to
expose it to the rest of the kernel. This requires that the probe functions
must also be local to tracing. But luckily nothing else uses them.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The function-fork option is same as event-fork that it tracks task
fork/exit and set the pid filter properly. This can be useful if user
wants to trace selected tasks including their children only.
Link: http://lkml.kernel.org/r/20170417024430.21194-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When function tracer has a pid filter, it adds a probe to sched_switch
to track if current task can be ignored. The probe checks the
ftrace_ignore_pid from current tr to filter tasks. But it misses to
delete the probe when removing an instance so that it can cause a crash
due to the invalid tr pointer (use-after-free).
This is easily reproducible with the following:
# cd /sys/kernel/debug/tracing
# mkdir instances/buggy
# echo $$ > instances/buggy/set_ftrace_pid
# rmdir instances/buggy
============================================================================
BUG: KASAN: use-after-free in ftrace_filter_pid_sched_switch_probe+0x3d/0x90
Read of size 8 by task kworker/0:1/17
CPU: 0 PID: 17 Comm: kworker/0:1 Tainted: G B 4.11.0-rc3 #198
Call Trace:
dump_stack+0x68/0x9f
kasan_object_err+0x21/0x70
kasan_report.part.1+0x22b/0x500
? ftrace_filter_pid_sched_switch_probe+0x3d/0x90
kasan_report+0x25/0x30
__asan_load8+0x5e/0x70
ftrace_filter_pid_sched_switch_probe+0x3d/0x90
? fpid_start+0x130/0x130
__schedule+0x571/0xce0
...
To fix it, use ftrace_clear_pids() to unregister the probe. As
instance_rmdir() already updated ftrace codes, it can just free the
filter safely.
Link: http://lkml.kernel.org/r/20170417024430.21194-2-namhyung@kernel.org
Fixes: 0c8916c342 ("tracing: Add rmdir to remove multibuffer instances")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The trace_event benchmark thread runs in kernel space in an infinite loop
while also calling cond_resched() in case anything else wants to schedule
in. Unfortunately, on a PREEMPT kernel, that makes it a nop, in which case,
this will never voluntarily schedule. That will cause synchronize_rcu_tasks()
to forever block on this thread, while it is running.
This is exactly what cond_resched_rcu_qs() is for. Use that instead.
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
t_hash_start() does not increment *pos, where as t_next() must. But when
t_next() does increment *pos, it must still pass in the original *pos to
t_hash_start() otherwise it will skip the first instance:
# cd /sys/kernel/debug/tracing
# echo schedule:traceoff > set_ftrace_filter
# echo do_IRQ:traceoff > set_ftrace_filter
# echo call_rcu > set_ftrace_filter
# cat set_ftrace_filter
call_rcu
schedule:traceoff:unlimited
do_IRQ:traceoff:unlimited
The above called t_hash_start() from t_start() as there was only one
function (call_rcu), but if we add another function:
# echo xfrm_policy_destroy_rcu >> set_ftrace_filter
# cat set_ftrace_filter
call_rcu
xfrm_policy_destroy_rcu
do_IRQ:traceoff:unlimited
The "schedule:traceoff" disappears.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Conflicts were simply overlapping changes. In the net/ipv4/route.c
case the code had simply moved around a little bit and the same fix
was made in both 'net' and 'net-next'.
In the net/sched/sch_generic.c case a fix in 'net' happened at
the same time that a new argument was added to qdisc_hash_add().
Signed-off-by: David S. Miller <davem@davemloft.net>
There's no need to have struct bpf_prog_type_list since
it just contains a list_head, the type, and the ops
pointer. Since the types are densely packed and not
actually dynamically registered, it's much easier and
smaller to have an array of type->ops pointer. Also
initialize this array statically to remove code needed
to initialize it.
In order to save duplicating the list, move it to a new
header file and include it in the places needing it.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tracing uses rcu_irq_enter() as a way to make sure that RCU is watching when
it needs to use rcu_read_lock() and friends. This is because tracing can
happen as RCU is about to enter user space, or about to go idle, and RCU
does not watch for RCU read side critical sections as it makes the
transition.
There is a small location within the RCU infrastructure that rcu_irq_enter()
itself will not work. If tracing were to occur in that section it will break
if it tries to use rcu_irq_enter().
Originally, this happens with the stack_tracer, because it will call
save_stack_trace when it encounters stack usage that is greater than any
stack usage it had encountered previously. There was a case where that
happened in the RCU section where rcu_irq_enter() did not work, and lockdep
complained loudly about it. To fix it, stack tracing added a call to be
disabled and RCU would disable stack tracing during the critical section
that rcu_irq_enter() was inoperable. This solution worked, but there are
other cases that use rcu_irq_enter() and it would be a good idea to let RCU
give a way to let others know that rcu_irq_enter() will not work. For
example, in trace events.
Another helpful aspect of this change is that it also moves the per cpu
variable called in the RCU critical section into a cache locale along with
other RCU per cpu variables used in that same location.
I'm keeping the stack_trace_disable() code, as that still could be used in
the future by places that really need to disable it. And since it's only a
static inline, it wont take up any kernel text if it is not used.
Link: http://lkml.kernel.org/r/20170405093207.404f8deb@gandalf.local.home
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In order to eliminate a function call, make "trace_active" into
"disable_stack_tracer" and convert stack_tracer_disable() and friends into
static inline functions.
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There are certain parts of the kernel that cannot let stack tracing
proceed (namely in RCU), because the stack tracer uses RCU, and parts of RCU
internals cannot handle having RCU read side locks taken.
Add stack_tracer_disable() and stack_tracer_enable() functions to let RCU
stop stack tracing on the current CPU when it is in those critical sections.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The updates to the trace_active per cpu variable can be updated with the
__this_cpu_*() functions as it only gets updated on the CPU that the variable
is on.
Thanks to Paul McKenney for suggesting __this_cpu_* instead of this_cpu_*.
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The function tracer needs to be more careful than other subsystems when it
comes to freeing data. Especially if that data is actually executable code.
When a single function is traced, a trampoline can be dynamically allocated
which is called to jump to the function trace callback. When the callback is
no longer needed, the dynamic allocated trampoline needs to be freed. This
is where the issues arise. The dynamically allocated trampoline must not be
used again. As function tracing can trace all subsystems, including
subsystems that are used to serialize aspects of freeing (namely RCU), it
must take extra care when doing the freeing.
Before synchronize_rcu_tasks() was around, there was no way for the function
tracer to know that nothing was using the dynamically allocated trampoline
when CONFIG_PREEMPT was enabled. That's because a task could be indefinitely
preempted while sitting on the trampoline. Now with synchronize_rcu_tasks(),
it will wait till all tasks have either voluntarily scheduled (not on the
trampoline) or goes into userspace (not on the trampoline). Then it is safe
to free the trampoline even with CONFIG_PREEMPT set.
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In case of error, the function kthread_run() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check
should be replaced with IS_ERR().
Link: http://lkml.kernel.org/r/1466184839-14927-1-git-send-email-weiyj_lk@163.com
Cc: stable@vger.kernel.org
Fixes: 6c43e554a ("ring-buffer: Add ring buffer startup selftest")
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When a kretprobe is installed on a kernel function, there is a maximum
limit of how many calls in parallel it can catch (aka "maxactive"). A
kernel module could call register_kretprobe() and initialize maxactive
(see example in samples/kprobes/kretprobe_example.c).
But that is not exposed to userspace and it is currently not possible to
choose maxactive when writing to /sys/kernel/debug/tracing/kprobe_events
The default maxactive can be as low as 1 on single-core with a
non-preemptive kernel. This is too low and we need to increase it not
only for recursive functions, but for functions that sleep or resched.
This patch updates the format of the command that can be written to
kprobe_events so that maxactive can be optionally specified.
I need this for a bpf program attached to the kretprobe of
inet_csk_accept, which can sleep for a long time.
This patch includes a basic selftest:
> # ./ftracetest -v test.d/kprobe/
> === Ftrace unit tests ===
> [1] Kprobe dynamic event - adding and removing [PASS]
> [2] Kprobe dynamic event - busy event check [PASS]
> [3] Kprobe dynamic event with arguments [PASS]
> [4] Kprobes event arguments with types [PASS]
> [5] Kprobe dynamic event with function tracer [PASS]
> [6] Kretprobe dynamic event with arguments [PASS]
> [7] Kretprobe dynamic event with maxactive [PASS]
>
> # of passed: 7
> # of failed: 0
> # of unresolved: 0
> # of untested: 0
> # of unsupported: 0
> # of xfailed: 0
> # of undefined(test bug): 0
BugLink: https://github.com/iovisor/bcc/issues/1072
Link: http://lkml.kernel.org/r/1491215782-15490-1-git-send-email-alban@kinvolk.io
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Relying on free_reserved_area() to call ftrace to free init memory proved to
not be sufficient. The issue is that on x86, when debug_pagealloc is
enabled, the init memory is not freed, but simply set as not present. Since
ftrace was uninformed of this, starting function tracing still tries to
update pages that are not present according to the page tables, causing
ftrace to bug, as well as killing the kernel itself.
Instead of relying on free_reserved_area(), have init/main.c call ftrace
directly just before it frees the init memory. Then it needs to use
__init_begin and __init_end to know where the init memory location is.
Looking at all archs (and testing what I can), it appears that this should
work for each of them.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
I noticed that if I use dd to read the set_ftrace_filter file that the first
hash command is repeated.
# cd /sys/kernel/debug/tracing
# echo schedule > set_ftrace_filter
# echo do_IRQ >> set_ftrace_filter
# echo schedule:traceoff >> set_ftrace_filter
# echo do_IRQ:traceoff >> set_ftrace_filter
# cat set_ftrace_filter
schedule
do_IRQ
schedule:traceoff:unlimited
do_IRQ:traceoff:unlimited
# dd if=set_ftrace_filter bs=1
schedule
do_IRQ
schedule:traceoff:unlimited
schedule:traceoff:unlimited
do_IRQ:traceoff:unlimited
98+0 records in
98+0 records out
98 bytes copied, 0.00265011 s, 37.0 kB/s
This is due to the way t_start() calls t_next() as well as the seq_file
calls t_next() and the state is slightly different between the two. Namely,
t_start() will call t_next() with a local "pos" variable.
By separating out the function listing from t_next() into its own function,
we can have better control of outputting the functions and the hash of
triggers. This simplifies the code.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If all functions are enabled, there's a comment displayed in the file to
denote that:
# cd /sys/kernel/debug/tracing
# cat set_ftrace_filter
#### all functions enabled ####
If a function trigger is set, those are displayed as well:
# echo schedule:traceoff >> /debug/tracing/set_ftrace_filter
# cat set_ftrace_filter
#### all functions enabled ####
schedule:traceoff:unlimited
But if you read that file with dd, the output can change:
# dd if=/debug/tracing/set_ftrace_filter bs=1
#### all functions enabled ####
32+0 records in
32+0 records out
32 bytes copied, 7.0237e-05 s, 456 kB/s
This is because the "pos" variable is updated for the comment, but func_pos
is not. "func_pos" is used by the triggers (or hashes) to know how many
functions were printed and it bases its index from the pos - func_pos.
func_pos should be 1 to count for the comment printed. But since it is not,
t_hash_start() thinks that one trigger was already printed.
The cat gets to t_hash_start() via t_next() and not t_start() which updates
both pos and func_pos.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The loop in t_start() of calling t_next() will call t_hash_start() if the
pos is beyond the functions and enters the hash items. There's no reason to
check if p is NULL and call t_hash_start(), as that would be redundant.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Instead of testing if the hash to use is the filter_hash or the notrace_hash
at each iteration, do the test at open, and set the iter->hash to point to
the corresponding filter or notrace hash. Then use that directly instead of
testing which hash needs to be used each iteration.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The return status check of __seq_open_private() is rather strange:
iter = __seq_open_private();
if (iter) {
/* do stuff */
}
return iter ? 0 : -ENOMEM;
It makes much more sense to do the return of failure right away:
iter = __seq_open_private();
if (!iter)
return -ENOMEM;
/* do stuff */
return 0;
This clean up will make updates to this code a bit nicer.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently trace_handle_return() looks like this:
static inline enum print_line_t trace_handle_return(struct trace_seq *s)
{
return trace_seq_has_overflowed(s) ?
TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
}
Where trace_seq_overflowed(s) is:
static inline bool trace_seq_has_overflowed(struct trace_seq *s)
{
return s->full || seq_buf_has_overflowed(&s->seq);
}
And seq_buf_has_overflowed(&s->seq) is:
static inline bool
seq_buf_has_overflowed(struct seq_buf *s)
{
return s->len > s->size;
}
Making trace_handle_return() into:
return (s->full || (s->seq->len > s->seq->size)) ?
TRACE_TYPE_PARTIAL_LINE :
TRACE_TYPE_HANDLED;
One would think this is not an issue to keep as an inline. But because this
is used in the TRACE_EVENT() macro, it is extended for every tracepoint in
the system. Taking a look at a single tracepoint x86_irq_vector (was the
first one I randomly chosen). As trace_handle_return is used in the
TRACE_EVENT() macro of trace_raw_output_##call() we disassemble
trace_raw_output_x86_irq_vector and do a diff:
- is the original
+ is the out-of-line code
I removed identical lines that were different just due to different
addresses.
--- /tmp/irq-vec-orig 2017-03-16 09:12:48.569384851 -0400
+++ /tmp/irq-vec-ool 2017-03-16 09:13:39.378153385 -0400
@@ -6,27 +6,23 @@
53 push %rbx
48 89 fb mov %rdi,%rbx
4c 8b a7 c0 20 00 00 mov 0x20c0(%rdi),%r12
e8 f7 72 13 00 callq ffffffff81155c80 <trace_raw_output_prep>
83 f8 01 cmp $0x1,%eax
74 05 je ffffffff8101e993 <trace_raw_output_x86_irq_vector+0x23>
5b pop %rbx
41 5c pop %r12
5d pop %rbp
c3 retq
41 8b 54 24 08 mov 0x8(%r12),%edx
- 48 8d bb 98 10 00 00 lea 0x1098(%rbx),%rdi
+ 48 81 c3 98 10 00 00 add $0x1098,%rbx
- 48 c7 c6 7b 8a a0 81 mov $0xffffffff81a08a7b,%rsi
+ 48 c7 c6 ab 8a a0 81 mov $0xffffffff81a08aab,%rsi
- e8 c5 85 13 00 callq ffffffff81156f70 <trace_seq_printf>
=== here's the start of the main difference ===
+ 48 89 df mov %rbx,%rdi
+ e8 62 7e 13 00 callq ffffffff81156810 <trace_seq_printf>
- 8b 93 b8 20 00 00 mov 0x20b8(%rbx),%edx
- 31 c0 xor %eax,%eax
- 85 d2 test %edx,%edx
- 75 11 jne ffffffff8101e9c8 <trace_raw_output_x86_irq_vector+0x58>
- 48 8b 83 a8 20 00 00 mov 0x20a8(%rbx),%rax
- 48 39 83 a0 20 00 00 cmp %rax,0x20a0(%rbx)
- 0f 93 c0 setae %al
+ 48 89 df mov %rbx,%rdi
+ e8 4a c5 12 00 callq ffffffff8114af00 <trace_handle_return>
5b pop %rbx
- 0f b6 c0 movzbl %al,%eax
=== end ===
41 5c pop %r12
5d pop %rbp
c3 retq
If you notice, the original has 22 bytes of text more than the out of line
version. As this is for every TRACE_EVENT() defined in the system, this can
become quite large.
text data bss dec hex filename
8690305 5450490 1298432 15439227 eb957b vmlinux-orig
8681725 5450490 1298432 15430647 eb73f7 vmlinux-handle
This change has a total of 8580 bytes in savings.
$ objdump -dr /tmp/vmlinux-orig | grep '^[0-9a-f]* <trace_raw_output' | wc -l
324
That's 324 tracepoints. But this does not include modules (which contain
many more tracepoints). For an allyesconfig build:
$ objdump -dr vmlinux-allyes-orig | grep '^[0-9a-f]* <trace_raw_output' | wc -l
1401
That's 1401 tracepoints giving us:
text data bss dec hex filename
137920629 140221067 53264384 331406080 13c0db00 vmlinux-allyes-orig
137827709 140221067 53264384 331313160 13bf7008 vmlinux-allyes-handle
92920 bytes in savings!!!
Link: http://lkml.kernel.org/r/20170315021431.13107-2-andi@firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Adding a hook into free_reserve_area() that informs ftrace that boot up init
text is being free, lets ftrace safely remove those init functions from its
records, which keeps ftrace from trying to modify text that no longer
exists.
Note, this still does not allow for tracing .init text of modules, as
modules require different work for freeing its init code.
Link: http://lkml.kernel.org/r/1488502497.7212.24.camel@linux.intel.com
Cc: linux-mm@kvack.org
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Requested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Register the function tracer right after the tracing buffers are initialized
in early boot up. This will allow function tracing to begin early if it is
enabled via the kernel command line.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
As tracing can now be enabled very early in boot up, even before some
critical system services (like scheduling), do not run the tracer selftests
until after early_initcall() is performed. If a tracer is registered before
such time, it is saved off in a list and the test is run when the system is
able to handle more diverse functions.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Create an early_trace_init() function that will initialize the buffers and
allow for ealier use of trace_printk(). This will also allow for future work
to have function tracing start earlier at boot up.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
New features:
- Add 'brstackinsn' field in 'perf script' to reuse the x86 instruction
decoder used in the Intel PT code to study hot paths to samples (Andi Kleen)
Kernel:
- Default UPROBES_EVENTS to Y (Alexei Starovoitov)
- Fix check for kretprobe offset within function entry (Naveen N. Rao)
Infrastructure:
- Introduce util func is_sdt_event() (Ravi Bangoria)
- Make perf_event__synthesize_mmap_events() scale on older kernels where
reading /proc/pid/maps is way slower than reading /proc/pid/task/pid/maps (Stephane Eranian)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-4.12-20170316' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Add 'brstackinsn' field in 'perf script' to reuse the x86 instruction
decoder used in the Intel PT code to study hot paths to samples (Andi Kleen)
Kernel changes:
- Default UPROBES_EVENTS to Y (Alexei Starovoitov)
- Fix check for kretprobe offset within function entry (Naveen N. Rao)
Infrastructure changes:
- Introduce util func is_sdt_event() (Ravi Bangoria)
- Make perf_event__synthesize_mmap_events() scale on older kernels where
reading /proc/pid/maps is way slower than reading /proc/pid/task/pid/maps (Stephane Eranian)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As it is already turned on by most distros, so just flip the default to
Y.
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: David Miller <davem@davemloft.net>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170316005817.GA6805@ast-mbp.thefacebook.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf specifies an offset from _text and since this offset is fed
directly into the arch-specific helper, kprobes tracer rejects
installation of kretprobes through perf. Fix this by looking up the
actual offset from a function for the specified sym+offset.
Refactor and reuse existing routines to limit code duplication -- we
repurpose kprobe_addr() for determining final kprobe address and we
split out the function entry offset determination into a separate
generic helper.
Before patch:
naveen@ubuntu:~/linux/tools/perf$ sudo ./perf probe -v do_open%return
probe-definition(0): do_open%return
symbol:do_open file:(null) line:0 offset:0 return:1 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /boot/vmlinux for symbols
Open Debuginfo file: /boot/vmlinux
Try to find probe point from debuginfo.
Matched function: do_open [2d0c7ff]
Probe point found: do_open+0
Matched function: do_open [35d76dc]
found inline addr: 0xc0000000004ba9c4
Failed to find "do_open%return",
because do_open is an inlined function and has no return point.
An error occurred in debuginfo analysis (-22).
Trying to use symbols.
Opening /sys/kernel/debug/tracing//README write=0
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: r:probe/do_open _text+4469776
Failed to write event: Invalid argument
Error: Failed to add events. Reason: Invalid argument (Code: -22)
naveen@ubuntu:~/linux/tools/perf$ dmesg | tail
<snip>
[ 33.568656] Given offset is not valid for return probe.
After patch:
naveen@ubuntu:~/linux/tools/perf$ sudo ./perf probe -v do_open%return
probe-definition(0): do_open%return
symbol:do_open file:(null) line:0 offset:0 return:1 lazy:(null)
0 arguments
Looking at the vmlinux_path (8 entries long)
Using /boot/vmlinux for symbols
Open Debuginfo file: /boot/vmlinux
Try to find probe point from debuginfo.
Matched function: do_open [2d0c7d6]
Probe point found: do_open+0
Matched function: do_open [35d76b3]
found inline addr: 0xc0000000004ba9e4
Failed to find "do_open%return",
because do_open is an inlined function and has no return point.
An error occurred in debuginfo analysis (-22).
Trying to use symbols.
Opening /sys/kernel/debug/tracing//README write=0
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: r:probe/do_open _text+4469808
Writing event: r:probe/do_open_1 _text+4956344
Added new events:
probe:do_open (on do_open%return)
probe:do_open_1 (on do_open%return)
You can now use it in all perf tools, such as:
perf record -e probe:do_open_1 -aR sleep 1
naveen@ubuntu:~/linux/tools/perf$ sudo cat /sys/kernel/debug/kprobes/list
c000000000041370 k kretprobe_trampoline+0x0 [OPTIMIZED]
c0000000004ba0b8 r do_open+0x8 [DISABLED]
c000000000443430 r do_open+0x0 [DISABLED]
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/d8cd1ef420ec22e3643ac332fdabcffc77319a42.1488961018.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix typos and add the following to the scripts/spelling.txt:
overide||override
While we are here, fix the doubled "address" in the touched line
Documentation/devicetree/bindings/regulator/ti-abb-regulator.txt.
Also, fix the comment block style in the touched hunks in
drivers/media/dvb-frontends/drx39xyj/drx_driver.h.
Link: http://lkml.kernel.org/r/1481573103-11329-21-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf fixes from Ingo Molnar:
"This includes a fix for a crash if certain special addresses are
kprobed, plus does a rename of two Kconfig variables that were a minor
misnomer"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS
kprobes/x86: Fix kernel panic when certain exception-handling addresses are probed
window. Namely powerpc broke as jump labels uses the two LSB bits as flags
in initialization. A check was added to make sure that all jump label
entries were 4 bytes aligned, but powerpc didn't work that way for modules.
Adding an alignment in the module linker script appeared to be the best
solution.
Jump labels also added an anonymous union to access those LSB bits as a
normal long. But because this structure had static initialization, it broke
older compilers that could not statically initialize anonymous unions
without brackets.
The command line parameter for setting function graph filter broke the
"EMPTY_HASH" descriptor by modifying it instead of creating a new hash to
hold the entries.
The command line parameter ftrace_graph_max_depth was added to allow its
setting at boot time. It uses existing code and only the command line hook
was added. This is not really a fix, but as it uses existing code without
affecting anything else, I added it to this release. It was ready before the
merge window closed, but I wanted to let it sit in linux-next for a couple
of days first.
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Merge tag 'trace-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"There was some breakage with the changes for jump labels in the 4.11
merge window:
- powerpc broke as jump labels uses the two LSB bits as flags in
initialization.
A check was added to make sure that all jump label entries were 4
bytes aligned, but powerpc didn't work that way for modules. Adding
an alignment in the module linker script appeared to be the best
solution.
- Jump labels also added an anonymous union to access those LSB bits
as a normal long. But because this structure had static
initialization, it broke older compilers that could not statically
initialize anonymous unions without brackets.
- The command line parameter for setting function graph filter broke
the "EMPTY_HASH" descriptor by modifying it instead of creating a
new hash to hold the entries.
- The command line parameter ftrace_graph_max_depth was added to
allow its setting at boot time. It uses existing code and only the
command line hook was added.
This is not really a fix, but as it uses existing code without
affecting anything else, I added it to this release. It was ready
before the merge window closed, but I wanted to let it sit in
linux-next for a couple of days first"
* tag 'trace-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/graph: Add ftrace_graph_max_depth kernel parameter
tracing: Add #undef to fix compile error
jump_label: Add comment about initialization order for anonymous unions
jump_label: Fix anonymous union initialization
module: set __jump_table alignment to 8
ftrace/graph: Do not modify the EMPTY_HASH for the function_graph filter
tracing: Fix code comment for ftrace_ops_get_func()
New features:
- Allow sorting by symbol_size in 'perf report' and 'perf top' (Charles Baylis)
E.g.:
# perf report -s symbol_size,symbol
Samples: 9K of event 'cycles:k', Event count (approx.): 2870461623
Overhead Symbol size Symbol
14.55% 326 [k] flush_tlb_mm_range
7.20% 1045 [k] filemap_map_pages
5.82% 124 [k] vma_interval_tree_insert
5.18% 2430 [k] unmap_page_range
2.57% 571 [k] vma_interval_tree_remove
1.94% 494 [k] page_add_file_rmap
1.82% 740 [k] page_remove_rmap
1.66% 1017 [k] release_pages
1.57% 1636 [k] update_blocked_averages
1.57% 76 [k] unlock_page
- Add support for -p/--pid, -a/--all-cpus and -C/--cpu in 'perf ftrace' (Namhyung Kim)
Change in behaviour:
- Make system wide (-a) the default option if no target was specified and one
of following conditions is met:
- No workload specified (current behaviour)
- A workload is specified but all requested events are system wide ones,
like uncore ones. (Jiri Olsa)
Fixes:
- Add missing initialization to the instruction decoder used in the
intel PT/BTS code, which was causing lots of failures in 'perf test',
looking for a value when there was none (Adrian Hunter)
Infrastructure:
- Add arch code needed to adopt the kernel's refcount_t to aid in
catching bugs when using atomic_t as a reference counter, basically
cmpxchg related functions (Arnaldo Carvalho de Melo)
- Convert the code using atomic_t as reference counts to refcount_t
(Elena Rashetova)
- Add feature test for sched_getcpu() to more easily check for its
presence in the many libc implementations and accross different
versions of such C libraries (Arnaldo Carvalho de Melo)
- Issue a HW watchdog disable hint in 'perf stat' for when some of the
requested events can't get counted because a PMU counter is taken by that
watchdog (Borislav Petkov).
- Add mapping for Intel's KnightsMill PMU events (Karol Wachowski)
Documentation:
- Clarify the term 'convergence' in:
perf bench numa numa-mem -h --show_convergence (Jiri Olsa)
Kernel code:
- Ensure probe location is at function entry in kretprobes (Naveen N. Rao)
- Allow return probes with offsets and absolute addresses (Naveen N. Rao)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-4.11-20170306' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
New features:
- Allow sorting by symbol_size in 'perf report' and 'perf top' (Charles Baylis)
E.g.:
# perf report -s symbol_size,symbol
Samples: 9K of event 'cycles:k', Event count (approx.): 2870461623
Overhead Symbol size Symbol
14.55% 326 [k] flush_tlb_mm_range
7.20% 1045 [k] filemap_map_pages
5.82% 124 [k] vma_interval_tree_insert
5.18% 2430 [k] unmap_page_range
2.57% 571 [k] vma_interval_tree_remove
1.94% 494 [k] page_add_file_rmap
1.82% 740 [k] page_remove_rmap
1.66% 1017 [k] release_pages
1.57% 1636 [k] update_blocked_averages
1.57% 76 [k] unlock_page
- Add support for -p/--pid, -a/--all-cpus and -C/--cpu in 'perf ftrace' (Namhyung Kim)
Change in behaviour:
- Make system wide (-a) the default option if no target was specified and one
of following conditions is met:
- No workload specified (current behaviour)
- A workload is specified but all requested events are system wide ones,
like uncore ones. (Jiri Olsa)
Fixes:
- Add missing initialization to the instruction decoder used in the
intel PT/BTS code, which was causing lots of failures in 'perf test',
looking for a value when there was none (Adrian Hunter)
Infrastructure changes:
- Add arch code needed to adopt the kernel's refcount_t to aid in
catching bugs when using atomic_t as a reference counter, basically
cmpxchg related functions (Arnaldo Carvalho de Melo)
- Convert the code using atomic_t as reference counts to refcount_t
(Elena Rashetova)
- Add feature test for sched_getcpu() to more easily check for its
presence in the many libc implementations and accross different
versions of such C libraries (Arnaldo Carvalho de Melo)
- Issue a HW watchdog disable hint in 'perf stat' for when some of the
requested events can't get counted because a PMU counter is taken by that
watchdog (Borislav Petkov).
- Add mapping for Intel's KnightsMill PMU events (Karol Wachowski)
Documentation changes:
- Clarify the term 'convergence' in:
perf bench numa numa-mem -h --show_convergence (Jiri Olsa)
Kernel code changes:
- Ensure probe location is at function entry in kretprobes (Naveen N. Rao)
- Allow return probes with offsets and absolute addresses (Naveen N. Rao)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Let's not remove the warning about offsets and return probes when the
offset is invalid.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20170227115204.00f92846@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since the kernel includes many non-global functions with same names, we
will need to use offsets from other symbols (typically _text/_stext) or
absolute addresses to place return probes on specific functions. Also,
the core register_kretprobe() API never forbid use of offsets or
absolute addresses with kretprobes.
Allow its use with the trace infrastructure. To distinguish kernels that
support this, update ftrace README to explicitly call this out.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/183e7ce2921a08c9c755ee9a5da3134febc6695b.1487770934.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Early trace callgraphs can be extremely large on systems with
several seconds of boot time. The max_depth parameter limits how
deep the graph trace goes and reduces the output size. This
parameter is the same as the max_graph_depth file in tracefs.
Link: http://lkml.kernel.org/r/1488499935-23216-1-git-send-email-todd.e.brandt@linux.intel.com
Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com>
[ changed comments about debugfs to tracefs ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
On boot up, if the kernel command line sets a graph funtion with the kernel
command line options "ftrace_graph_filter" or "ftrace_graph_notrace" then it
updates the corresponding function graph hash, ftrace_graph_hash or
ftrace_graph_notrace_hash respectively. Unfortunately, at boot up, these
variables are pointers to the "EMPTY_HASH" which is a constant used as a
placeholder when a hash has no entities. The problem was that the comand
line version to set the hashes updated the actual EMPTY_HASH instead of
creating a new hash for the function graph. This broke the EMPTY_HASH
because not only did it modify a constant (not sure how that was allowed to
happen, except maybe because it was done at early boot, const variables were
still mutable), but it made the filters have functions listed in them when
they were actually empty.
The kernel command line function needs to allocate a new hash for the
function graph filters and assign the necessary variables to that new hash
instead.
Link: http://lkml.kernel.org/r/1488420091.7212.17.camel@linux.intel.com
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: b9b0c831be ("ftrace: Convert graph filter to use hash tables")
Reported-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We don't actually need the full rculist.h header in sched.h anymore,
we will be able to include the smaller rcupdate.h header instead.
But first update code that relied on the implicit header inclusion.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/mm.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
The APIs that are going to be moved first are:
mm_alloc()
__mmdrop()
mmdrop()
mmdrop_async_fn()
mmdrop_async()
mmget_not_zero()
mmput()
mmput_async()
get_task_mm()
mm_access()
mm_release()
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to move scheduler ABI details to <uapi/linux/sched/types.h>,
which will be used from a number of .c files.
Create empty placeholder header that maps to <linux/types.h>.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.
Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We have uses of CONFIG_UPROBE_EVENT and CONFIG_KPROBE_EVENT as
well as CONFIG_UPROBE_EVENTS and CONFIG_KPROBE_EVENTS.
Consistently use the plurals.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: davem@davemloft.net
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20170216060050.20866-1-anton@ozlabs.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
bug that was caused by a race condition in initializing the hwlat
thread. When fixing this code, I realized that it should have been done
differently. Instead of doing the rewrite and sending that to stable,
I just sent the above commit to fix the bug that should be back ported.
This commit is on top of the quick fix commit to rewrite the code the
way it should have been written in the first place.
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Merge tag 'trace-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull another tracing update from Steven Rostedt:
"Commit 79c6f448c8 ("tracing: Fix hwlat kthread migration") fixed a
bug that was caused by a race condition in initializing the hwlat
thread. When fixing this code, I realized that it should have been
done differently. Instead of doing the rewrite and sending that to
stable, I just sent the above commit to fix the bug that should be
back ported.
This commit is on top of the quick fix commit to rewrite the code the
way it should have been written in the first place"
* tag 'trace-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Clean up the hwlat binding code
and small optimizations.
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Merge tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This release has no new tracing features, just clean ups, minor fixes
and small optimizations"
* tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (25 commits)
tracing: Remove outdated ring buffer comment
tracing/probes: Fix a warning message to show correct maximum length
tracing: Fix return value check in trace_benchmark_reg()
tracing: Use modern function declaration
jump_label: Reduce the size of struct static_key
tracing/probe: Show subsystem name in messages
tracing/hwlat: Update old comment about migration
timers: Make flags output in the timer_start tracepoint useful
tracing: Have traceprobe_probes_write() not access userspace unnecessarily
tracing: Have COMM event filter key be treated as a string
ftrace: Have set_graph_function handle multiple functions in one write
ftrace: Do not hold references of ftrace_graph_{notrace_}hash out of graph_lock
tracing: Reset parser->buffer to allow multiple "puts"
ftrace: Have set_graph_functions handle write with RDWR
ftrace: Reset fgd->hash in ftrace_graph_write()
ftrace: Replace (void *)1 with a meaningful macro name FTRACE_GRAPH_EMPTY
ftrace: Create a slight optimization on searching the ftrace_hash
tracing: Add ftrace_hash_key() helper function
ftrace: Convert graph filter to use hash tables
ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip
...
There is no function 'ftrace_ops_recurs_func' existing in the current code,
it was renamed to ftrace_ops_assist_func() in commit c68c0fa293
("ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too").
Update the comment to the correct function name.
Link: http://lkml.kernel.org/r/1487723366-14463-1-git-send-email-chuhu@redhat.com
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull namespace updates from Eric Biederman:
"There is a lot here. A lot of these changes result in subtle user
visible differences in kernel behavior. I don't expect anything will
care but I will revert/fix things immediately if any regressions show
up.
From Seth Forshee there is a continuation of the work to make the vfs
ready for unpriviled mounts. We had thought the previous changes
prevented the creation of files outside of s_user_ns of a filesystem,
but it turns we missed the O_CREAT path. Ooops.
Pavel Tikhomirov and Oleg Nesterov worked together to fix a long
standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only
children that are forked after the prctl are considered and not
children forked before the prctl. The only known user of this prctl
systemd forks all children after the prctl. So no userspace
regressions will occur. Holding earlier forked children to the same
rules as later forked children creates a semantic that is sane enough
to allow checkpoing of processes that use this feature.
There is a long delayed change by Nikolay Borisov to limit inotify
instances inside a user namespace.
Michael Kerrisk extends the API for files used to maniuplate
namespaces with two new trivial ioctls to allow discovery of the
hierachy and properties of namespaces.
Konstantin Khlebnikov with the help of Al Viro adds code that when a
network namespace exits purges it's sysctl entries from the dcache. As
in some circumstances this could use a lot of memory.
Vivek Goyal fixed a bug with stacked filesystems where the permissions
on the wrong inode were being checked.
I continue previous work on ptracing across exec. Allowing a file to
be setuid across exec while being ptraced if the tracer has enough
credentials in the user namespace, and if the process has CAP_SETUID
in it's own namespace. Proc files for setuid or otherwise undumpable
executables are now owned by the root in the user namespace of their
mm. Allowing debugging of setuid applications in containers to work
better.
A bug I introduced with permission checking and automount is now
fixed. The big change is to mark the mounts that the kernel initiates
as a result of an automount. This allows the permission checks in sget
to be safely suppressed for this kind of mount. As the permission
check happened when the original filesystem was mounted.
Finally a special case in the mount namespace is removed preventing
unbounded chains in the mount hash table, and making the semantics
simpler which benefits CRIU.
The vfs fix along with related work in ima and evm I believe makes us
ready to finish developing and merge fully unprivileged mounts of the
fuse filesystem. The cleanups of the mount namespace makes discussing
how to fix the worst case complexity of umount. The stacked filesystem
fixes pave the way for adding multiple mappings for the filesystem
uids so that efficient and safer containers can be implemented"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc/sysctl: Don't grab i_lock under sysctl_lock.
vfs: Use upper filesystem inode in bprm_fill_uid()
proc/sysctl: prune stale dentries during unregistering
mnt: Tuck mounts under others instead of creating shadow/side mounts.
prctl: propagate has_child_subreaper flag to every descendant
introduce the walk_process_tree() helper
nsfs: Add an ioctl() to return owner UID of a userns
fs: Better permission checking for submounts
exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction
vfs: open() with O_CREAT should not create inodes with unknown ids
nsfs: Add an ioctl() to return the namespace type
proc: Better ownership of files for non-dumpable tasks in user namespaces
exec: Remove LSM_UNSAFE_PTRACE_CAP
exec: Test the ptracer's saved cred to see if the tracee can gain caps
exec: Don't reset euid and egid when the tracee has CAP_SETUID
inotify: Convert to using per-namespace limits
Patch series "DAX tracepoints, mm argument simplification", v4.
This contains both my DAX tracepoint code and Dave Jiang's MM argument
simplifications. Dave's code was written with my tracepoint code as a
baseline, so it seemed simplest to keep them together in a single series.
This patch (of 7):
Add __print_flags_u64() and the helper trace_print_flags_seq_u64() in the
same spirit as __print_symbolic_u64() and trace_print_symbols_seq_u64().
These functions allow us to print symbols associated with flags that are
64 bits wide even on 32 bit machines.
These will be used by the DAX code so that we can print the flags set in a
pfn_t such as PFN_SG_CHAIN, PFN_SG_LAST, PFN_DEV and PFN_MAP.
Without this new function I was getting errors like the following when
compiling for i386:
include/linux/pfn_t.h:13:22: warning: large integer implicitly truncated to unsigned type [-Woverflow]
#define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
^
Link: http://lkml.kernel.org/r/1484085142-2297-2-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
"Highlights:
1) Support TX_RING in AF_PACKET TPACKET_V3 mode, from Sowmini
Varadhan.
2) Simplify classifier state on sk_buff in order to shrink it a bit.
From Willem de Bruijn.
3) Introduce SIPHASH and it's usage for secure sequence numbers and
syncookies. From Jason A. Donenfeld.
4) Reduce CPU usage for ICMP replies we are going to limit or
suppress, from Jesper Dangaard Brouer.
5) Introduce Shared Memory Communications socket layer, from Ursula
Braun.
6) Add RACK loss detection and allow it to actually trigger fast
recovery instead of just assisting after other algorithms have
triggered it. From Yuchung Cheng.
7) Add xmit_more and BQL support to mvneta driver, from Simon Guinot.
8) skb_cow_data avoidance in esp4 and esp6, from Steffen Klassert.
9) Export MPLS packet stats via netlink, from Robert Shearman.
10) Significantly improve inet port bind conflict handling, especially
when an application is restarted and changes it's setting of
reuseport. From Josef Bacik.
11) Implement TX batching in vhost_net, from Jason Wang.
12) Extend the dummy device so that VF (virtual function) features,
such as configuration, can be more easily tested. From Phil
Sutter.
13) Avoid two atomic ops per page on x86 in bnx2x driver, from Eric
Dumazet.
14) Add new bpf MAP, implementing a longest prefix match trie. From
Daniel Mack.
15) Packet sample offloading support in mlxsw driver, from Yotam Gigi.
16) Add new aquantia driver, from David VomLehn.
17) Add bpf tracepoints, from Daniel Borkmann.
18) Add support for port mirroring to b53 and bcm_sf2 drivers, from
Florian Fainelli.
19) Remove custom busy polling in many drivers, it is done in the core
networking since 4.5 times. From Eric Dumazet.
20) Support XDP adjust_head in virtio_net, from John Fastabend.
21) Fix several major holes in neighbour entry confirmation, from
Julian Anastasov.
22) Add XDP support to bnxt_en driver, from Michael Chan.
23) VXLAN offloads for enic driver, from Govindarajulu Varadarajan.
24) Add IPVTAP driver (IP-VLAN based tap driver) from Sainath Grandhi.
25) Support GRO in IPSEC protocols, from Steffen Klassert"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1764 commits)
Revert "ath10k: Search SMBIOS for OEM board file extension"
net: socket: fix recvmmsg not returning error from sock_error
bnxt_en: use eth_hw_addr_random()
bpf: fix unlocking of jited image when module ronx not set
arch: add ARCH_HAS_SET_MEMORY config
net: napi_watchdog() can use napi_schedule_irqoff()
tcp: Revert "tcp: tcp_probe: use spin_lock_bh()"
net/hsr: use eth_hw_addr_random()
net: mvpp2: enable building on 64-bit platforms
net: mvpp2: switch to build_skb() in the RX path
net: mvpp2: simplify MVPP2_PRS_RI_* definitions
net: mvpp2: fix indentation of MVPP2_EXT_GLOBAL_CTRL_DEFAULT
net: mvpp2: remove unused register definitions
net: mvpp2: simplify mvpp2_bm_bufs_add()
net: mvpp2: drop useless fields in mvpp2_bm_pool and related code
net: mvpp2: remove unused 'tx_skb' field of 'struct mvpp2_tx_queue'
net: mvpp2: release reference to txq_cpu[] entry after unmapping
net: mvpp2: handle too large value in mvpp2_rx_time_coal_set()
net: mvpp2: handle too large value handling in mvpp2_rx_pkts_coal_set()
net: mvpp2: remove useless arguments in mvpp2_rx_{pkts, time}_coal_set
...
All map types and prog types are registered to the BPF core through
bpf_register_map_type() and bpf_register_prog_type() during init and
remain unchanged thereafter. As by design we don't (and never will)
have any pluggable code that can register to that at any later point
in time, lets mark all the existing bpf_{map,prog}_type_list objects
in the tree as __ro_after_init, so they can be moved to read-only
section from then onwards.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The comment about ring buffer's organization is outdated and the code sits
elsewhere, remove the comment.
Link: http://lkml.kernel.org/r/20170217041058.23904-1-joelaf@google.com
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since tracing/*probe_events will accept a probe definition
up to 4096 - 2 ('\n' and '\0') bytes, it must show 4094 instead
of 4096 in warning message.
Note that there is one possible case of exceed 4094. If user
prepare 4096 bytes null-terminated string and syscall write
it with the count == 4095, then it can be accepted. However,
if user puts a '\n' after that, it must rejected.
So IMHO, the warning message should indicate shorter one,
since it is safer.
Link: http://lkml.kernel.org/r/148673290462.2579.7966778294009665632.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In case of error, the function kthread_run() returns ERR_PTR() and never
returns NULL. The NULL test in the return value check should be replaced
with IS_ERR().
Link: http://lkml.kernel.org/r/20170112135502.28556-1-weiyj.lk@gmail.com
Cc: stable@vger.kernel.org
Fixes: 81dc9f0e ("tracing: Add tracepoint benchmark tracepoint")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We get a lot of harmless warnings about this header file at W=1 level
because of an unusual function declaration:
kernel/trace/trace.h:766:1: error: 'inline' is not at beginning of declaration [-Werror=old-style-declaration]
This moves the inline statement where it normally belongs, avoiding the
warning.
Link: http://lkml.kernel.org/r/20170123122521.3389010-1-arnd@arndb.de
Fixes: 4046bf023b ("ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Show "trace_probe:", "trace_kprobe:" and "trace_uprobe:"
headers for each warning/error/info message. This will
help people to notice that kprobe/uprobe events caused
those messages.
Link: http://lkml.kernel.org/r/148646647813.24658.16705315294927615333.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The code in traceprobe_probes_write() reads up to 4096 bytes from userpace
for each line. If userspace passes in several lines to execute, the code
will do a large read for each line, even though, it is highly likely that
the first read from userspace received all of the lines at once.
I changed the logic to do a single read from userspace, and to only read
from userspace again if not all of the read from userspace made it in.
I tested this by adding printk()s and writing files that would test -1, ==,
and +1 the buffer size, to make sure that there's no overflows and that if a
single line is written with +1 the buffer size, that it fails properly.
Link: http://lkml.kernel.org/r/20170209180458.5c829ab2@gandalf.local.home
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The GLOB operation "~" should be able to work with the COMM filter key in
order to trace programs with a glob. For example
echo 'COMM ~ "systemd*"' > events/syscalls/filter
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The conflict was an interaction between a bug fix in the
netvsc driver in 'net' and an optimization of the RX path
in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Steven suggested to improve trace_print_hex_seq() a bit after commit
2acae0d5b0 ("trace: add variant without spacing in trace_print_hex_seq")
in two ways: i) by adding a kdoc comment for the helper function
itself and ii) by renaming 'spacing' argument into 'concatenate'
to better denote that we don't add spaces between each hex bytes.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, only one function can be written to set_graph_function and
set_graph_notrace. The last function in the list will have saved, even
though other functions will be added then removed.
Change the behavior to be the same as set_ftrace_function as to allow
multiple functions to be written. If any one fails, none of them will be
added. The addition of the functions are done at the end when the file is
closed.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The hashs ftrace_graph_hash and ftrace_graph_notrace_hash are modified
within the graph_lock being held. Holding a pointer to them and passing them
along can lead to a use of a stale pointer (fgd->hash). Move assigning the
pointer and its use to within the holding of the lock. Note, it's an
rcu_sched protected data, and other instances of referencing them are done
with preemption disabled. But the file manipuation code must be protected by
the lock.
The fgd->hash pointer is set to NULL when the lock is being released.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
trace_parser_put() simply frees the allocated parser buffer. But it does not
reset the pointer that was freed. This means that if trace_parser_put() is
called on the same parser more than once, it will corrupt the allocation
system. Setting parser->buffer to NULL after free allows it to be called
more than once without any ill effect.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since reading the set_graph_functions uses seq functions, which sets the
file->private_data pointer to a seq_file descriptor. On writes the
ftrace_graph_data descriptor is set to file->private_data. But if the file
is opened for RDWR, the ftrace_graph_write() will incorrectly use the
file->private_data descriptor instead of
((struct seq_file *)file->private_data)->private pointer, and this can crash
the kernel.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When the set_graph_function or set_graph_notrace contains no records, a
banner is displayed of either "#### all functions enabled ####" or
"#### all functions disabled ####" respectively. To tell the seq operations
to do this, (void *)1 is passed as a return value. Instead of using a
hardcoded meaningless variable, define it as a macro.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This is a micro-optimization, but as it has to deal with a fast path of the
function tracer, these optimizations can be noticed.
The ftrace_lookup_ip() returns true if the given ip is found in the hash. If
it's not found or the hash is NULL, it returns false. But there's some cases
that a NULL hash is a true, and the ftrace_hash_empty() is tested before
calling ftrace_lookup_ip() in those cases. But as ftrace_lookup_ip() tests
that first, that adds a few extra unneeded instructions in those cases.
A new static "always_inlined" function is created that does not perform the
hash empty test. This most only be used by callers that do the check first
anyway, as an empty or NULL hash could cause a crash if a lookup is
performed on it.
Also add kernel doc for the ftrace_lookup_ip() main function.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Replace the couple of use cases that has small logic to produce the ftrace
function key id with a helper function. No need for duplicate code.
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We may already have a directory to put the blktrace stuff in if
1. The disk uses blk-mq
2. CONFIG_BLK_DEBUG_FS is enabled
3. We are tracing the whole disk and not a partition
Instead of hardcoding this very specific case, let's use the new
debugfs_lookup(). If the directory exists, we use it, otherwise we
create one and clean it up later.
Fixes: 07e4fead45 ("blk-mq: create debugfs directory tree")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
When I added the blk-mq debugging information to debugfs, I didn't
notice that blktrace also creates a "block" directory in debugfs. Make
them use the same dentry, now created in the core block code. Based on a
patch from Jens.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
clang complains about "__init" being attached to a struct name:
kernel/trace/trace_kprobe.c:1375:15: error: '__section__' attribute only applies to functions and global variables
The intention must have been to mark the function as __init instead of
the type, so move the attribute there.
Link: http://lkml.kernel.org/r/20170201165826.2625888-1-arnd@arndb.de
Fixes: f18f97ac43 ("tracing/kprobes: Add a helper method to return number of probe hits")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
To support unprivileged users mounting filesystems two permission
checks have to be performed: a test to see if the user allowed to
create a mount in the mount namespace, and a test to see if
the user is allowed to access the specified filesystem.
The automount case is special in that mounting the original filesystem
grants permission to mount the sub-filesystems, to any user who
happens to stumble across the their mountpoint and satisfies the
ordinary filesystem permission checks.
Attempting to handle the automount case by using override_creds
almost works. It preserves the idea that permission to mount
the original filesystem is permission to mount the sub-filesystem.
Unfortunately using override_creds messes up the filesystems
ordinary permission checks.
Solve this by being explicit that a mount is a submount by introducing
vfs_submount, and using it where appropriate.
vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let
sget and friends know that a mount is a submount so they can take appropriate
action.
sget and sget_userns are modified to not perform any permission checks
on submounts.
follow_automount is modified to stop using override_creds as that
has proven problemantic.
do_mount is modified to always remove the new MS_SUBMOUNT flag so
that we know userspace will never by able to specify it.
autofs4 is modified to stop using current_real_cred that was put in
there to handle the previous version of submount permission checking.
cifs is modified to pass the mountpoint all of the way down to vfs_submount.
debugfs is modified to pass the mountpoint all of the way down to
trace_automount by adding a new parameter. To make this change easier
a new typedef debugfs_automount_t is introduced to capture the type of
the debugfs automount function.
Cc: stable@vger.kernel.org
Fixes: 069d5ac9ae ("autofs: Fix automounts by using current_real_cred()->uid")
Fixes: aeaa4a79ff ("fs: Call d_automount with the filesystems creds")
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Instead of initializing the affinity of the hwlat kthread in the thread
itself, simply set up the initial affinity at thread creation. This
simplifies the code.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This can be used to check for fs vs non-fs requests and basically
removes all knowledge of BLOCK_PC specific from the block layer,
as well as preparing for removing the cmd_type field in struct request.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The hwlat tracer creates a kernel thread at start of the tracer. It is
pinned to a single CPU and will move to the next CPU after each period of
running. If the user modifies the migration thread's affinity, it will not
change after that happens.
The original code created the thread at the first instance it was called,
but later was changed to destroy the thread after the tracer was finished,
and would not be created until the next instance of the tracer was
established. The code that initialized the affinity was only called on the
initial instantiation of the tracer. After that, it was not initialized, and
the previous affinity did not match the current newly created one, making
it appear that the user modified the thread's affinity when it did not, and
the thread failed to migrate again.
Cc: stable@vger.kernel.org
Fixes: 0330f7aa8e ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
A couple tweaks to the tracing code:
- trace the request size for all requests
- trace request sector and nr_sectors only for fs requests, enforced by
helpers
- drop SCSI CDB tracing - we have SCSI tracing for this and are going
to me the CDB out of the generic struct request soon.
With this the tracing code stops to know about BLOCK_PC requests entirely,
it's just FS vs passthrough requests now, where the latter includes any
driver-private requests.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
For upcoming tracepoint support for BPF, we want to dump the program's
tag. Format should be similar to __print_hex(), but without spacing.
Add a __print_hex_str() variant for exactly that purpose that reuses
trace_print_hex_seq().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use ftrace_hash instead of a static array of a fixed size. This is
useful when a graph filter pattern matches to a large number of
functions. Now hash lookup is done with preemption disabled to protect
from the hash being changed/freed.
Link: http://lkml.kernel.org/r/20170120024447.26097-3-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It will be used when checking graph filter hashes later.
Link: http://lkml.kernel.org/r/20170120024447.26097-2-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
[ Moved ftrace_hash dec and functions outside of FUNCTION_GRAPH define ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Provide a simple helper with the same semantics of strncpy_from_unsafe():
int bpf_probe_read_str(void *dst, int size, const void *unsafe_addr)
This gives more flexibility to a bpf program. A typical use case is
intercepting a file name during sys_open(). The current approach is:
SEC("kprobe/sys_open")
void bpf_sys_open(struct pt_regs *ctx)
{
char buf[PATHLEN]; // PATHLEN is defined to 256
bpf_probe_read(buf, sizeof(buf), ctx->di);
/* consume buf */
}
This is suboptimal because the size of the string needs to be estimated
at compile time, causing more memory to be copied than often necessary,
and can become more problematic if further processing on buf is done,
for example by pushing it to userspace via bpf_perf_event_output(),
since the real length of the string is unknown and the entire buffer
must be copied (and defining an unrolled strnlen() inside the bpf
program is a very inefficient and unfeasible approach).
With the new helper, the code can easily operate on the actual string
length rather than the buffer size:
SEC("kprobe/sys_open")
void bpf_sys_open(struct pt_regs *ctx)
{
char buf[PATHLEN]; // PATHLEN is defined to 256
int res = bpf_probe_read_str(buf, sizeof(buf), ctx->di);
/* consume buf, for example push it to userspace via
* bpf_perf_event_output(), but this time we can use
* res (the string length) as event size, after checking
* its boundaries.
*/
}
Another useful use case is when parsing individual process arguments or
individual environment variables navigating current->mm->arg_start and
current->mm->env_start: using this helper and the return value, one can
quickly iterate at the right offset of the memory area.
The code changes simply leverage the already existent
strncpy_from_unsafe() kernel function, which is safe to be called from a
bpf program as it is used in bpf_trace_printk().
Signed-off-by: Gianluca Borello <g.borello@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The __ftrace_hash_move() is to allocates properly-sized hash and move
entries in the src ftrace_hash. It will be used to set function graph
filters which has nothing to do with the dyn_ftrace records.
Link: http://lkml.kernel.org/r/20170120024447.26097-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The unlikely/likely branch profiler now gets called even if the if statement
is a constant (always goes in one direction without a compare). Add a value
to denote this in the likely/unlikely tracer as well.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Now that constants are traced, it is useful to see the number of constants
that are traced in the likely/unlikely profiler in order to know if they
should be ignored or not.
The likely/unlikely will display a number after the "correct" number if a
"constant" count exists.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When running the likely/unlikely profiler, one of the results did not look
accurate. It noted that the unlikely() in link_path_walk() was 100%
incorrect. When I added a trace_printk() to see what was happening there, it
became 80% correct! Looking deeper into what whas happening, I found that
gcc split that if statement into two paths. One where the if statement
became a constant, the other path a variable. The other path had the if
statement always hit (making the unlikely there, always false), but since
the #define unlikely() has:
#define unlikely() (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
Where constants are ignored by the branch profiler, the "constant" path
made by the compiler was ignored, even though it was hit 80% of the time.
By just passing the constant value to the __branch_check__() function and
tracing it out of line (as always correct, as likely/unlikely isn't a factor
for constants), then we get back the accurate readings of branches that were
optimized by gcc causing part of the execution to become constant.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Previously, `create_trace_uprobe` found the *first* occurence
of the ':' character when parsing `PATH:OFFSET` for a uprobe.
However, if the path contains a ':' character, then the function
would parse the path incorrectly. Even worse, if the path does not
exist, the subsequent call to `kern_path()` would set `ret` to
`ENOENT`, leading to very cryptic errno values in user space.
The fix is to find the *last* occurence of ':'.
How to repro:: The write fails with "No such file or directory", suggesting
incorrectly that the `uprobe_events` file does not exist.
$ mkdir testing && cd testing
$ cp /bin/bash .
$ cp /bin/bash ./bash:with:colon
$ echo "p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x6" > /sys/kernel/debug/tracing/uprobe_events # this works
$ echo "p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x6" >> /sys/kernel/debug/tracing/uprobe_events # this doesn't
-bash: echo: write error: No such file or directory
With the patch:
$ echo "p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x6" > /sys/kernel/debug/tracing/uprobe_events # this still works
$ echo "p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x6" >> /sys/kernel/debug/tracing/uprobe_events # this works now too!
$ cat /sys/kernel/debug/tracing/uprobe_events
p:uprobes/p__root_testing_bash_0x6 /root/testing/bash:0x0000000000000006
p:uprobes/p__root_testing_bash_with_colon_0x6 /root/testing/bash:with:colon:0x0000000000000006
Link: http://lkml.kernel.org/r/20170113165834.4081016-1-kennyyu@fb.com
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Make sure that ctx cannot potentially be accessed oob by asserting
explicitly that ctx access size into pt_regs for BPF_PROG_TYPE_KPROBE
programs must be within limits. In case some 32bit archs have pt_regs
not being a multiple of 8, then BPF_DW access could cause such access.
BPF_PROG_TYPE_KPROBE progs don't have a ctx conversion function since
there's no extra mapping needed. kprobe_prog_is_valid_access() didn't
enforce sizeof(long) as the only allowed access size, since LLVM can
generate non BPF_W/BPF_DW access to regs from time to time.
For BPF_PROG_TYPE_TRACEPOINT we don't have a ctx conversion either, so
add a BUILD_BUG_ON() check to make sure that BPF_DW access will not be
a similar issue in future (ctx works on event buffer as opposed to
pt_regs there).
Fixes: 2541517c32 ("tracing, perf: Implement BPF programs attached to kprobes")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, when calling convert_ctx_access() callback for the various
program types, we pass in insn->dst_reg, insn->src_reg, insn->off from
the original instruction. This information is needed to rewrite the
instruction that is based on the user ctx structure into a kernel
representation for the ctx. As we'd like to allow access size beyond
just BPF_W, we'd need also insn->code for that in order to decode the
original access size. Given that, lets just pass insn directly to the
convert_ctx_access() callback and work on that to not clutter the
callback with even more arguments we need to pass when everything is
already contained in insn. So lets go through that once, no functional
change.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
since ARG_PTR_TO_STACK is no longer just pointer to stack
rename it to ARG_PTR_TO_MEM and adjust comment.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no point in having an extra type for extra confusion. u64 is
unambiguous.
Conversion was done with the following coccinelle script:
@rem@
@@
-typedef u64 cycle_t;
@fix@
typedef cycle_t;
@@
-cycle_t
+u64
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
o STM can hook into the function tracer
o Function filtering now supports more advance glob matching
o Ftrace selftests updates and added tests
o Softirq tag in traces now show only softirqs
o ARM nop added to non traced locations at compile time
o New trace_marker_raw file that allows for binary input
o Optimizations to the ring buffer
o Removal of kmap in trace_marker
o Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
o Other various fixes and clean ups
Note, there are two patches marked for stable. These were discovered
near the end of the 4.9 rc release cycle. By the time I had them tested
it was just a matter of days before 4.9 would be released, and I
figured I would just submit them in the merge window. They are old
bugs and not critical. Nothing non-root could abuse.
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Merge tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This release has a few updates:
- STM can hook into the function tracer
- Function filtering now supports more advance glob matching
- Ftrace selftests updates and added tests
- Softirq tag in traces now show only softirqs
- ARM nop added to non traced locations at compile time
- New trace_marker_raw file that allows for binary input
- Optimizations to the ring buffer
- Removal of kmap in trace_marker
- Wakeup and irqsoff tracers now adhere to the set_graph_notrace file
- Other various fixes and clean ups"
* tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (42 commits)
selftests: ftrace: Shift down default message verbosity
kprobes/trace: Fix kprobe selftest for newer gcc
tracing/kprobes: Add a helper method to return number of probe hits
tracing/rb: Init the CPU mask on allocation
tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results
tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too
fgraph: Handle a case where a tracer ignores set_graph_notrace
tracing: Replace kmap with copy_from_user() in trace_marker writing
ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it
tracing: Allow benchmark to be enabled at early_initcall()
tracing: Have system enable return error if one of the events fail
tracing: Do not start benchmark on boot up
tracing: Have the reg function allow to fail
ring-buffer: Force rb_end_commit() and rb_set_commit_to_write() inline
ring-buffer: Froce rb_update_write_stamp() to be inlined
ring-buffer: Force inline of hotpath helper functions
tracing: Make __buffer_unlock_commit() always_inline
tracing: Make tracepoint_printk a static_key
ring-buffer: Always inline rb_event_data()
ring-buffer: Make rb_reserve_next_event() always inlined
...
Pull block layer updates from Jens Axboe:
"This is the main block pull request this series. Contrary to previous
release, I've kept the core and driver changes in the same branch. We
always ended up having dependencies between the two for obvious
reasons, so makes more sense to keep them together. That said, I'll
probably try and keep more topical branches going forward, especially
for cycles that end up being as busy as this one.
The major parts of this pull request is:
- Improved support for O_DIRECT on block devices, with a small
private implementation instead of using the pig that is
fs/direct-io.c. From Christoph.
- Request completion tracking in a scalable fashion. This is utilized
by two components in this pull, the new hybrid polling and the
writeback queue throttling code.
- Improved support for polling with O_DIRECT, adding a hybrid mode
that combines pure polling with an initial sleep. From me.
- Support for automatic throttling of writeback queues on the block
side. This uses feedback from the device completion latencies to
scale the queue on the block side up or down. From me.
- Support from SMR drives in the block layer and for SD. From Hannes
and Shaun.
- Multi-connection support for nbd. From Josef.
- Cleanup of request and bio flags, so we have a clear split between
which are bio (or rq) private, and which ones are shared. From
Christoph.
- A set of patches from Bart, that improve how we handle queue
stopping and starting in blk-mq.
- Support for WRITE_ZEROES from Chaitanya.
- Lightnvm updates from Javier/Matias.
- Supoort for FC for the nvme-over-fabrics code. From James Smart.
- A bunch of fixes from a whole slew of people, too many to name
here"
* 'for-4.10/block' of git://git.kernel.dk/linux-block: (182 commits)
blk-stat: fix a few cases of missing batch flushing
blk-flush: run the queue when inserting blk-mq flush
elevator: make the rqhash helpers exported
blk-mq: abstract out blk_mq_dispatch_rq_list() helper
blk-mq: add blk_mq_start_stopped_hw_queue()
block: improve handling of the magic discard payload
blk-wbt: don't throttle discard or write zeroes
nbd: use dev_err_ratelimited in io path
nbd: reset the setup task for NBD_CLEAR_SOCK
nvme-fabrics: Add FC LLDD loopback driver to test FC-NVME
nvme-fabrics: Add target support for FC transport
nvme-fabrics: Add host support for FC transport
nvme-fabrics: Add FC transport LLDD api definitions
nvme-fabrics: Add FC transport FC-NVME definitions
nvme-fabrics: Add FC transport error codes to nvme.h
Add type 0x28 NVME type code to scsi fc headers
nvme-fabrics: patch target code in prep for FC transport support
nvme-fabrics: set sqe.command_id in core not transports
parser: add u64 number parser
nvme-rdma: align to generic ib_event logging helper
...
- Add additional checks for bad platform data
- Remove bounce buffer in console writer
- Protect read/unlink race with a mutex
- Correctly give up during dump locking failures
- Increase ftrace bandwidth by splitting ftrace buffers per CPU
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Merge tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull pstore updates from Kees Cook:
"Improvements and fixes to pstore subsystem:
- add additional checks for bad platform data
- remove bounce buffer in console writer
- protect read/unlink race with a mutex
- correctly give up during dump locking failures
- increase ftrace bandwidth by splitting ftrace buffers per CPU"
* tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
ramoops: add pdata NULL check to ramoops_probe
pstore: Convert console write to use ->write_buf
pstore: Protect unlink with read_mutex
pstore: Use global ftrace filters for function trace filtering
ftrace: Provide API to use global filtering for ftrace ops
pstore: Clarify context field przs as dprzs
pstore: improve error report for failed setup
pstore: Merge per-CPU ftrace records into one
pstore: Add ftrace timestamp counter
ramoops: Split ftrace buffer space into per-CPU zones
pstore: Make ramoops_init_przs generic for other prz arrays
pstore: Allow prz to control need for locking
pstore: Warn on PSTORE_TYPE_PMSG using deprecated function
pstore: Make spinlock per zone instead of global
pstore: Actually give up during locking failure
Pull timer updates from Thomas Gleixner:
"The time/timekeeping/timer folks deliver with this update:
- Fix a reintroduced signed/unsigned issue and cleanup the whole
signed/unsigned mess in the timekeeping core so this wont happen
accidentaly again.
- Add a new trace clock based on boot time
- Prevent injection of random sleep times when PM tracing abuses the
RTC for storage
- Make posix timers configurable for real tiny systems
- Add tracepoints for the alarm timer subsystem so timer based
suspend wakeups can be instrumented
- The usual pile of fixes and updates to core and drivers"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
timekeeping: Use mul_u64_u32_shr() instead of open coding it
timekeeping: Get rid of pointless typecasts
timekeeping: Make the conversion call chain consistently unsigned
timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion
alarmtimer: Add tracepoints for alarm timers
trace: Update documentation for mono, mono_raw and boot clock
trace: Add an option for boot clock as trace clock
timekeeping: Add a fast and NMI safe boot clock
timekeeping/clocksource_cyc2ns: Document intended range limitation
timekeeping: Ignore the bogus sleep time if pm_trace is enabled
selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous"
clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap
clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()
arm64: dts: rockchip: Arch counter doesn't tick in system suspend
clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend
posix-timers: Make them configurable
posix_cpu_timers: Move the add_device_randomness() call to a proper place
timer: Move sys_alarm from timer.c to itimer.c
ptp_clock: Allow for it to be optional
Kconfig: Regenerate *.c_shipped files after previous changes
...
Pull smp hotplug updates from Thomas Gleixner:
"This is the final round of converting the notifier mess to the state
machine. The removal of the notifiers and the related infrastructure
will happen around rc1, as there are conversions outstanding in other
trees.
The whole exercise removed about 2000 lines of code in total and in
course of the conversion several dozen bugs got fixed. The new
mechanism allows to test almost every hotplug step standalone, so
usage sites can exercise all transitions extensively.
There is more room for improvement, like integrating all the
pointlessly different architecture mechanisms of synchronizing,
setting cpus online etc into the core code"
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
tracing/rb: Init the CPU mask on allocation
soc/fsl/qbman: Convert to hotplug state machine
soc/fsl/qbman: Convert to hotplug state machine
zram: Convert to hotplug state machine
KVM/PPC/Book3S HV: Convert to hotplug state machine
arm64/cpuinfo: Convert to hotplug state machine
arm64/cpuinfo: Make hotplug notifier symmetric
mm/compaction: Convert to hotplug state machine
iommu/vt-d: Convert to hotplug state machine
mm/zswap: Convert pool to hotplug state machine
mm/zswap: Convert dst-mem to hotplug state machine
mm/zsmalloc: Convert to hotplug state machine
mm/vmstat: Convert to hotplug state machine
mm/vmstat: Avoid on each online CPU loops
mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
tracing/rb: Convert to hotplug state machine
oprofile/nmi timer: Convert to hotplug state machine
net/iucv: Use explicit clean up labels in iucv_init()
x86/pci/amd-bus: Convert to hotplug state machine
x86/oprofile/nmi: Convert to hotplug state machine
...
Commit 265a5b7ee3 ("kprobes/trace: Fix kprobe selftest for gcc 4.6")
has added __used attribute to kprobe_trace_selftest_target to ensure
that the method is listed in kallsyms table.
However, even though the method remains in the kernel image, the actual
call is optimized away as there are no side effects and the return value
is never checked.
Add a return value check and a 'noinline' attribute to ensure that an
inlined copy of the method is not used by the caller. Also add checks
that verify that the kprobe was really hit, as at the moment the tests
show positive results despite the test method being optimized away.
Finally, add __init annotations to find_trace_probe_file() and
kprobe_trace_selftest_target() as they are only called from within an
__init method.
Link: http://lkml.kernel.org/r/1481293178-3128-2-git-send-email-marcin.nowakowski@imgtec.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The number of probe hits is stored in a percpu variable and therefore
can't be read directly. Add a helper method trace_kprobe_nhit() that
performs the required calculation.
It will be used in a follow-up commit that changes kprobe selftests to
verify the number of probe hits.
Link: http://lkml.kernel.org/r/1481293178-3128-1-git-send-email-marcin.nowakowski@imgtec.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Before commit b32614c034 ("tracing/rb: Convert to hotplug state
machine") the allocated cpumask was initialized to the mask of ONLINE or
POSSIBLE CPUs. After the CPU hotplug changes the buffer initialisation
moved to trace_rb_cpu_prepare() but I forgot to initially set the
cpumask to zero. This is done now.
Link: http://lkml.kernel.org/r/20161207133133.hzkcqfllxcdi3joz@linutronix.de
Fixes: b32614c034 ("tracing/rb: Convert to hotplug state machine")
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The 's' flag is supposed to indicate that a softirq is running. This
can be detected by testing the preempt_count with SOFTIRQ_OFFSET.
The current code tests the preempt_count with SOFTIRQ_MASK, which
would be true even when softirqs are disabled but not serving a
softirq.
Link: http://lkml.kernel.org/r/1481300417-3564-1-git-send-email-pkondeti@codeaurora.org
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently both the wakeup and irqsoff traces do not handle set_graph_notrace
well. The ftrace infrastructure will ignore the return paths of all
functions leaving them hanging without an end:
# echo '*spin*' > set_graph_notrace
# cat trace
[...]
_raw_spin_lock() {
preempt_count_add() {
do_raw_spin_lock() {
update_rq_clock();
Where the '*spin*' functions should have looked like this:
_raw_spin_lock() {
preempt_count_add();
do_raw_spin_lock();
}
update_rq_clock();
Instead, have the wakeup and irqsoff tracers ignore the functions that are
set by the set_graph_notrace like the function_graph tracer does. Move
the logic in the function_graph tracer into a header to allow wakeup and
irqsoff tracers to use it as well.
Cc: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Both the wakeup and irqsoff tracers can use the function graph tracer when
the display-graph option is set. The problem is that they ignore the notrace
file, and record the entry of functions that would be ignored by the
function_graph tracer. This causes the trace->depth to be recorded into the
ring buffer. The set_graph_notrace uses a trick by adding a large negative
number to the trace->depth when a graph function is to be ignored.
On trace output, the graph function uses the depth to record a stack of
functions. But since the depth is negative, it accesses the array with a
negative number and causes an out of bounds access that can cause a kernel
oops or corrupt data.
Have the print functions handle cases where a tracer still records functions
even when they are in set_graph_notrace.
Also add warnings if the depth is below zero before accessing the array.
Note, the function graph logic will still prevent the return of these
functions from being recorded, which means that they will be left hanging
without a return. For example:
# echo '*spin*' > set_graph_notrace
# echo 1 > options/display-graph
# echo wakeup > current_tracer
# cat trace
[...]
_raw_spin_lock() {
preempt_count_add() {
do_raw_spin_lock() {
update_rq_clock();
Where it should look like:
_raw_spin_lock() {
preempt_count_add();
do_raw_spin_lock();
}
update_rq_clock();
Cc: stable@vger.kernel.org
Cc: Namhyung Kim <namhyung.kim@lge.com>
Fixes: 29ad23b004 ("ftrace: Add set_graph_notrace filter")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Instead of using get_user_pages_fast() and kmap_atomic() when writing
to the trace_marker file, just allocate enough space on the ring buffer
directly, and write into it via copy_from_user().
Writing into the trace_marker file use to allocate a temporary buffer
to perform the copy_from_user(), as we didn't want to write into the
ring buffer if the copy failed. But as a trace_marker write is suppose
to be extremely fast, and allocating memory causes other tracepoints to
trigger, Peter Zijlstra suggested using get_user_pages_fast() and
kmap_atomic() to keep the user space pages in memory and reading it
directly. But Henrik Austad had issues with this because it required taking
the mm->mmap_sem and causing long delays with the write.
Instead, just allocate the space in the ring buffer and use
copy_from_user() directly. If it faults, return -EFAULT and write
"<faulted>" into the ring buffer.
Link: http://lkml.kernel.org/r/20161208124018.72dd0f86@gandalf.local.home
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Henrik Austad <henrik@austad.us>
Cc: Peter Zijlstra <peterz@infradead.org>
Updates: d696b58ca2 "tracing: Do not allocate buffer for trace_marker"
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The trace event start up selftests fails when the trace benchmark is
enabled, because it is disabled during boot. It really only needs to be
disabled before scheduling is set up, as it creates a thread.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If one of the events within a system fails to enable when "1" is written
to the system "enable" file, it should return an error. Note, some events
may still be enabled, but the user should know that something did go wrong.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Trace events are enabled very early on boot up via the boot command line
parameter. The benchmark tool creates a new thread to perform the trace
event benchmarking. But at start up, it is called before scheduling is set
up and because it creates a new thread before the init thread is created,
this crashes the kernel.
Have the benchmark fail to register when started via the kernel command
line.
Also, since the registering of a tracepoint now can handle failure cases,
return -ENOMEM instead of warning if the thread cannot be created.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Some tracepoints have a registration function that gets enabled when the
tracepoint is enabled. There may be cases that the registraction function
must fail (for example, can't allocate enough memory). In this case, the
tracepoint should also fail to register, otherwise the user would not know
why the tracepoint is not working.
Cc: David Howells <dhowells@redhat.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Before commit b32614c034 ("tracing/rb: Convert to hotplug state machine")
the allocated cpumask was initialized to the mask of online or possible
CPUs. After the CPU hotplug changes the buffer initialization moved to
trace_rb_cpu_prepare() but the cpumask is allocated with alloc_cpumask()
and therefor has random content. As a consequence the cpu buffers are not
initialized and a later access dereferences a NULL pointer.
Use zalloc_cpumask() instead so trace_rb_cpu_prepare() initializes the
buffers properly.
Fixes: b32614c034 ("tracing/rb: Convert to hotplug state machine")
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20161207133133.hzkcqfllxcdi3joz@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Install the callbacks via the state machine. The notifier in struct
ring_buffer is replaced by the multi instance interface. Upon
__ring_buffer_alloc() invocation, cpuhp_state_add_instance() will invoke
the trace_rb_cpu_prepare() on each CPU.
This callback may now fail. This means __ring_buffer_alloc() will fail and
cleanup (like previously) and during a CPU up event this failure will not
allow the CPU to come up.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161126231350.10321-7-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Unlike monotonic clock, boot clock as a trace clock will account for
time spent in suspend useful for tracing suspend/resume. This uses
earlier introduced infrastructure for using the fast boot clock.
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Link: http://lkml.kernel.org/r/1480372524-15181-7-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Both rb_end_commit() and rb_set_commit_to_write() are in the fast path of
the ring buffer recording. Make sure they are always inlined.
Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The function rb_update_write_stamp() is in the hotpath of the ring buffer
recording. Make sure that it is inlined as well. There's not many places
that call it.
Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There's several small helper functions in ring_buffer.c that are used in the
hot path. For some reason, even though they are marked inline, gcc tends not
to enforce it. Make sure these functions are always inlined.
Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The function __buffer_unlock_commit() is called in a few places outside of
trace.c. But for the most part, it should really be inlined, as it is in the
hot path of the trace_events. For the callers outside of trace.c, create a
new function trace_buffer_unlock_commit_nostack(), as the reason it was used
was to avoid the stack tracing that trace_buffer_unlock_commit() could do.
Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently, when tracepoint_printk is set (enabled by the "tp_printk" kernel
command line), it causes trace events to print via printk(). This is a very
dangerous operation, but is useful for debugging.
The issue is, it's seldom used, but it is always checked even if it's not
enabled by the kernel command line. Instead of having this feature called by
a branch against a variable, turn that variable into a static key, and this
will remove the test and jump.
To simplify things, the functions output_printk() and
trace_event_buffer_commit() were moved from trace_events.c to trace.c.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The rb_event_data() is the fast path of getting the ring buffer data from an
event. Externally, ring_buffer_event_data() is used to access this function.
But unfortunately, rb_event_data() is not inlined, and calling
ring_buffer_event_data() causes that function to be called again. Force
rb_event_data() to be inlined to lower the number of operations needed when
calling ring_buffer_event_data().
Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The function rb_reserved_next_event() is called by two functions:
ring_buffer_lock_reserve() and ring_buffer_write(). This is in a very hot
path of the tracing code, and it is best that they are not functions. The
two callers are basically wrapers for rb_reserver_next_event(). Removing the
function calls can save execution time in the hotpath of tracing.
Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As Andi Kleen pointed out in the Link below, the trace events has quite a
bit of code execution. A lot of that happens to be calling functions, where
some of them should simply be inlined. One of these functions happens to be
trace_buffer_lock_reserve() which is also a global, but it is used
throughout the file it is defined in. Create a __trace_buffer_lock_reserve()
that is always inlined that the file can benefit from.
Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.org
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The creation of the set_event_pid file was assigned to a variable "entry"
but that variable was never used. Ideally, it should be used to check if the
file was created and warn if it was not.
The files header_page, header_event should also be checked and a warning if
they fail to be created.
The "enable" file was moved up, as it is a more crucial file to have and a
hard failure (return -ENOMEM) should be returned if it is not created.
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently Function traces can be only exported to the ring buffer. This
adds a trace_export concept which can process traces and export
them to a registered destination as an addition to the current
one that outputs to Ftrace - i.e. ring buffer.
In this way, if we want function traces to be sent to other destinations
rather than only to the ring buffer, we just need to register a new
trace_export and implement its own .write() function for writing traces to
storage.
With this patch, only function tracing (trace type is TRACE_FN)
is supported.
Link: http://lkml.kernel.org/r/1479715043-6534-2-git-send-email-zhang.chunyan@linaro.org
Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
All conflicts were simple overlapping changes except perhaps
for the Thunder driver.
That driver has a change_mtu method explicitly for sending
a message to the hardware. If that fails it returns an
error.
Normally a driver doesn't need an ndo_change_mtu method becuase those
are usually just range changes, which are now handled generically.
But since this extra operation is needed in the Thunder driver, it has
to stay.
However, if the message send fails we have to restore the original
MTU before the change because the entire call chain expects that if
an error is thrown by ndo_change_mtu then the MTU did not change.
Therefore code is added to nicvf_change_mtu to remember the original
MTU, and to restore it upon nicvf_update_hw_max_frs() failue.
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the global_ops filtering hash is not available to outside users
registering for function tracing. Provide an API for those users to be
able to choose global filtering.
This is in preparation for pstore's ftrace feature to be able to
use the global filters.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
A new file is created:
/sys/kernel/debug/tracing/trace_marker_raw
This allows for appications to create data structures and write the binary
data directly into it, and then read the trace data out from trace_pipe_raw
into the same type of data structure. This saves on converting numbers into
ASCII that would be required by trace_marker.
Suggested-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The trace_events_file.c filter logic can be a bit complex. I copy this into
a userspace program where I can debug it a bit easier. One issue is the op
is defined in most places as an int instead of as an enum, and gdb just
gives the value when debugging. Having the actual op name shown in gdb is
more useful.
This has no functionality change, but helps in debugging when the file is
debugged in user space.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently the filter logic for comparisons (like greater-than and less-than)
are used, they share the same function and a switch statement is used to
jump to the comparison type to perform. This is done in the extreme hot path
of the tracing code, and it does not take much more space to create a
unique comparison function to perform each type of comparison and remove the
switch statement.
Also, a bug was found where the binary and operation for 64 bits could fail
if the resulting bits were greater than 32 bits, because the result was
passed into a 32 bit variable. This was fixed when adding the separate
binary and function.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Use glob_match() to support flexible glob wildcards (*,?)
and character classes ([) for ftrace.
Since the full glob matching is slower than the current
partial matching routines(*pat, pat*, *pat*), this leaves
those routines and just add MATCH_GLOB for complex glob
expression.
e.g.
----
[root@localhost tracing]# echo 'sched*group' > set_ftrace_filter
[root@localhost tracing]# cat set_ftrace_filter
sched_free_group
sched_change_group
sched_create_group
sched_online_group
sched_destroy_group
sched_offline_group
[root@localhost tracing]# echo '[Ss]y[Ss]_*' > set_ftrace_filter
[root@localhost tracing]# head set_ftrace_filter
sys_arch_prctl
sys_rt_sigreturn
sys_ioperm
SyS_iopl
sys_modify_ldt
SyS_mmap
SyS_set_thread_area
SyS_get_thread_area
SyS_set_tid_address
sys_fork
----
Link: http://lkml.kernel.org/r/147566869501.29136.6462645009894738056.stgit@devbox
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When a module is first loaded and its function ip records are added to the
ftrace list of functions to modify, they are set to DISABLED, as their text
is still in a read only state. When the module is fully loaded, and can be
updated, the flag is cleared, and if their's any functions that should be
tracing them, it is updated at that moment.
But there's several locations that do record accounting and should ignore
records that are marked as disabled, or they can cause issues.
Alexei already fixed one location, but others need to be addressed.
Cc: stable@vger.kernel.org
Fixes: b7ffffbb46 "ftrace: Add infrastructure for delayed enabling of module functions"
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
ftrace_shutdown() checks for sanity of ftrace records
and if dyn_ftrace->flags is not zero, it will warn.
It can happen that 'flags' are set to FTRACE_FL_DISABLED at this point,
since some module was loaded, but before ftrace_module_enable()
cleared the flags for this module.
In other words the module.c is doing:
ftrace_module_init(mod); // calls ftrace_update_code() that sets flags=FTRACE_FL_DISABLED
... // here ftrace_shutdown() is called that warns, since
err = prepare_coming_module(mod); // didn't have a chance to clear FTRACE_FL_DISABLED
Fix it by ignoring disabled records.
It's similar to what __ftrace_hash_rec_update() is already doing.
Link: http://lkml.kernel.org/r/1478560460-3818619-1-git-send-email-ast@fb.com
Cc: stable@vger.kernel.org
Fixes: b7ffffbb46 "ftrace: Add infrastructure for delayed enabling of module functions"
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Now that we don't need the common flags to overflow outside the range
of a 32-bit type we can encode them the same way for both the bio and
request fields. This in addition allows us to place the operation
first (and make some room for more ops while we're at it) and to
stop having to shift around the operation values.
In addition this allows passing around only one value in the block layer
instead of two (and eventuall also in the file systems, but we can do
that later) and thus clean up a lot of code.
Last but not least this allows decreasing the size of the cmd_flags
field in struct request to 32-bits. Various functions passing this
value could also be updated, but I'd like to avoid the churn for now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Use case is mainly for soreuseport to select sockets for the local
numa node, but since generic, lets also add this for other networking
and tracing program types.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This affectively reverts commit 377ccbb483 ("Makefile: Mute warning
for __builtin_return_address(>0) for tracing only") because it turns out
that it really isn't tracing only - it's all over the tree.
We already also had the warning disabled separately for mm/usercopy.c
(which this commit also removes), and it turns out that we will also
want to disable it for get_lock_parent_ip(), that is used for at least
TRACE_IRQFLAGS. Which (when enabled) ends up being all over the tree.
Steven Rostedt had a patch that tried to limit it to just the config
options that actually triggered this, but quite frankly, the extra
complexity and abstraction just isn't worth it. We have never actually
had a case where the warning is actually useful, so let's just disable
it globally and not worry about it.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The big change is the addition of the hwlat tracer. It not only detects
SMIs, but also other latency that's caused by the hardware. I have detected
some latency from large boxes having bus contention.
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Merge tag 'trace-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This release cycle is rather small. Just a few fixes to tracing.
The big change is the addition of the hwlat tracer. It not only
detects SMIs, but also other latency that's caused by the hardware. I
have detected some latency from large boxes having bus contention"
* tag 'trace-v4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Call traceoff trigger after event is recorded
ftrace/scripts: Add helper script to bisect function tracing problem functions
tracing: Have max_latency be defined for HWLAT_TRACER as well
tracing: Add NMI tracing in hwlat detector
tracing: Have hwlat trace migrate across tracing_cpumask CPUs
tracing: Add documentation for hwlat_detector tracer
tracing: Added hardware latency tracer
ftrace: Access ret_stack->subtime only in the function profiler
function_graph: Handle TRACE_BPUTS in print_graph_comment
tracing/uprobe: Drop isdigit() check in create_trace_uprobe
Pull networking updates from David Miller:
1) BBR TCP congestion control, from Neal Cardwell, Yuchung Cheng and
co. at Google. https://lwn.net/Articles/701165/
2) Do TCP Small Queues for retransmits, from Eric Dumazet.
3) Support collect_md mode for all IPV4 and IPV6 tunnels, from Alexei
Starovoitov.
4) Allow cls_flower to classify packets in ip tunnels, from Amir Vadai.
5) Support DSA tagging in older mv88e6xxx switches, from Andrew Lunn.
6) Support GMAC protocol in iwlwifi mwm, from Ayala Beker.
7) Support ndo_poll_controller in mlx5, from Calvin Owens.
8) Move VRF processing to an output hook and allow l3mdev to be
loopback, from David Ahern.
9) Support SOCK_DESTROY for UDP sockets. Also from David Ahern.
10) Congestion control in RXRPC, from David Howells.
11) Support geneve RX offload in ixgbe, from Emil Tantilov.
12) When hitting pressure for new incoming TCP data SKBs, perform a
partial rathern than a full purge of the OFO queue (which could be
huge). From Eric Dumazet.
13) Convert XFRM state and policy lookups to RCU, from Florian Westphal.
14) Support RX network flow classification to igb, from Gangfeng Huang.
15) Hardware offloading of eBPF in nfp driver, from Jakub Kicinski.
16) New skbmod packet action, from Jamal Hadi Salim.
17) Remove some inefficiencies in snmp proc output, from Jia He.
18) Add FIB notifications to properly propagate route changes to
hardware which is doing forwarding offloading. From Jiri Pirko.
19) New dsa driver for qca8xxx chips, from John Crispin.
20) Implement RFC7559 ipv6 router solicitation backoff, from Maciej
Żenczykowski.
21) Add L3 mode to ipvlan, from Mahesh Bandewar.
22) Support 802.1ad in mlx4, from Moshe Shemesh.
23) Support hardware LRO in mediatek driver, from Nelson Chang.
24) Add TC offloading to mlx5, from Or Gerlitz.
25) Convert various drivers to ethtool ksettings interfaces, from
Philippe Reynes.
26) TX max rate limiting for cxgb4, from Rahul Lakkireddy.
27) NAPI support for ath10k, from Rajkumar Manoharan.
28) Support XDP in mlx5, from Rana Shahout and Saeed Mahameed.
29) UDP replicast support in TIPC, from Richard Alpe.
30) Per-queue statistics for qed driver, from Sudarsana Reddy Kalluru.
31) Support BQL in thunderx driver, from Sunil Goutham.
32) TSO support in alx driver, from Tobias Regnery.
33) Add stream parser engine and use it in kcm.
34) Support async DHCP replies in ipconfig module, from Uwe
Kleine-König.
35) DSA port fast aging for mv88e6xxx driver, from Vivien Didelot.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1715 commits)
mlxsw: switchx2: Fix misuse of hard_header_len
mlxsw: spectrum: Fix misuse of hard_header_len
net/faraday: Stop NCSI device on shutdown
net/ncsi: Introduce ncsi_stop_dev()
net/ncsi: Rework the channel monitoring
net/ncsi: Allow to extend NCSI request properties
net/ncsi: Rework request index allocation
net/ncsi: Don't probe on the reserved channel ID (0x1f)
net/ncsi: Introduce NCSI_RESERVED_CHANNEL
net/ncsi: Avoid unused-value build warning from ia64-linux-gcc
net: Add netdev all_adj_list refcnt propagation to fix panic
net: phy: Add Edge-rate driver for Microsemi PHYs.
vmxnet3: Wake queue from reset work
i40e: avoid NULL pointer dereference and recursive errors on early PCI error
qed: Add RoCE ll2 & GSI support
qed: Add support for memory registeration verbs
qed: Add support for QP verbs
qed: PD,PKEY and CQ verb support
qed: Add support for RoCE hw init
qede: Add qedr framework
...
Pull low-level x86 updates from Ingo Molnar:
"In this cycle this topic tree has become one of those 'super topics'
that accumulated a lot of changes:
- Add CONFIG_VMAP_STACK=y support to the core kernel and enable it on
x86 - preceded by an array of changes. v4.8 saw preparatory changes
in this area already - this is the rest of the work. Includes the
thread stack caching performance optimization. (Andy Lutomirski)
- switch_to() cleanups and all around enhancements. (Brian Gerst)
- A large number of dumpstack infrastructure enhancements and an
unwinder abstraction. The secret long term plan is safe(r) live
patching plus maybe another attempt at debuginfo based unwinding -
but all these current bits are standalone enhancements in a frame
pointer based debug environment as well. (Josh Poimboeuf)
- More __ro_after_init and const annotations. (Kees Cook)
- Enable KASLR for the vmemmap memory region. (Thomas Garnier)"
[ The virtually mapped stack changes are pretty fundamental, and not
x86-specific per se, even if they are only used on x86 right now. ]
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
x86/asm: Get rid of __read_cr4_safe()
thread_info: Use unsigned long for flags
x86/alternatives: Add stack frame dependency to alternative_call_2()
x86/dumpstack: Fix show_stack() task pointer regression
x86/dumpstack: Remove dump_trace() and related callbacks
x86/dumpstack: Convert show_trace_log_lvl() to use the new unwinder
oprofile/x86: Convert x86_backtrace() to use the new unwinder
x86/stacktrace: Convert save_stack_trace_*() to use the new unwinder
perf/x86: Convert perf_callchain_kernel() to use the new unwinder
x86/unwind: Add new unwind interface and implementations
x86/dumpstack: Remove NULL task pointer convention
fork: Optimize task creation by caching two thread stacks per CPU if CONFIG_VMAP_STACK=y
sched/core: Free the stack early if CONFIG_THREAD_INFO_IN_TASK
lib/syscall: Pin the task stack in collect_syscall()
x86/process: Pin the target stack in get_wchan()
x86/dumpstack: Pin the target stack when dumping it
kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function
sched/core: Add try_get_task_stack() and put_task_stack()
x86/entry/64: Fix a minor comment rebase error
iommu/amd: Don't put completion-wait semaphore on stack
...
Pull perf updates from Ingo Molnar:
"The main kernel side changes were:
- uprobes enhancements (Masami Hiramatsu)
- Uncore group events enhancements (David Carrillo-Cisneros)
- x86 Intel: Add support for Skylake server uncore PMUs (Kan Liang)
- x86 Intel: LBR cleanups and enhancements, for better branch
annotation tracking (Peter Zijlstra)
- x86 Intel: Add support for PTWRITE and power event tracing
(Alexander Shishkin)
- ... various fixes, cleanups and smaller enhancements.
Lots of tooling changes - a couple of highlights:
- Support event group view with hierarchy mode in 'perf top' and
'perf report' (Namhyung Kim)
e.g.:
$ perf record -e '{cycles,instructions}' make
$ perf report --hierarchy --stdio
...
# Overhead Command / Shared Object / Symbol
# ...................... ..................................
...
25.74% 27.18%sh
19.96% 24.14%libc-2.24.so
9.55% 14.64%[.] __strcmp_sse2
1.54% 0.00%[.] __tfind
1.07% 1.13%[.] _int_malloc
0.95% 0.00%[.] __strchr_sse2
0.89% 1.39%[.] __tsearch
0.76% 0.00%[.] strlen
- Add branch stack / basic block info to 'perf annotate --stdio',
where for each branch, we add an asm comment after the instruction
with information on how often it was taken and predicted. See
example with color output at:
http://vger.kernel.org/~acme/perf/annotate_basic_blocks.png
(Peter Zijlstra)
- Add support for using symbols in address filters with Intel PT and
ARM CoreSight (hardware assisted tracing facilities) (Adrian
Hunter, Mathieu Poirier)
- Add support for interacting with Coresight PMU ETMs/PTMs, that are
IP blocks to perform hardware assisted tracing on a ARM CPU core
(Mathieu Poirier)
- Support generating cross arch probes, i.e. if you specify a vmlinux
file for different arch than the one in the host machine,
$ perf probe --definition function_name args
will generate the probe definition string needed to append to the
target machine /sys/kernel/debug/tracing/kprobes_events file, using
scripting (Masami Hiramatsu).
- Allow configuring the default 'perf report -s' sort order in
~/.perfconfig, for instance, "sym,dso" may be more fitting for
kernel developers. (Arnaldo Carvalho de Melo)
- ... plus lots of other changes, refactorings, features and fixes"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (149 commits)
perf tests: Add dwarf unwind test for powerpc
perf probe: Match linkage name with mangled name
perf probe: Fix to cut off incompatible chars from group name
perf probe: Skip if the function address is 0
perf probe: Ignore the error of finding inline instance
perf intel-pt: Fix decoding when there are address filters
perf intel-pt: Enable decoder to handle TIP.PGD with missing IP
perf intel-pt: Read address filter from AUXTRACE_INFO event
perf intel-pt: Record address filter in AUXTRACE_INFO event
perf intel-pt: Add a helper function for processing AUXTRACE_INFO
perf intel-pt: Fix missing error codes processing auxtrace_info
perf intel-pt: Add support for recording the max non-turbo ratio
perf intel-pt: Fix snapshot overlap detection decoder errors
perf probe: Increase debug level of SDT debug messages
perf record: Add support for using symbols in address filters
perf symbols: Add dso__last_symbol()
perf record: Fix error paths
perf record: Rename label 'out_symbol_exit'
perf script: Fix vanished idle symbols
perf evsel: Add support for address filters
...
pr_info message spans two lines and the literal string is missing
a white space between words. Add the white space.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
some issues. This contains one fix by me and one by Al. I'm sure that
he'll come up with more but for now I tested these patches and they
don't appear to have any negative impact on tracing.
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Merge tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracefs fixes from Steven Rostedt:
"Al Viro has been looking at the tracefs code, and has pointed out some
issues. This contains one fix by me and one by Al. I'm sure that
he'll come up with more but for now I tested these patches and they
don't appear to have any negative impact on tracing"
* tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
fix memory leaks in tracing_buffers_splice_read()
tracing: Move mutex to protect against resetting of seq data
The iter->seq can be reset outside the protection of the mutex. So can
reading of user data. Move the mutex up to the beginning of the function.
Fixes: d7350c3f45 ("tracing/core: make the read callbacks reentrants")
Cc: stable@vger.kernel.org # 2.6.30+
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Call traceoff trigger after the event is recorded.
Since current traceoff trigger is called before recording
the event, we can not know what event stopped tracing.
Typical usecase of traceoff/traceon trigger is tracing
function calls and trace events between a pair of events.
For example, trace function calls between syscall entry/exit.
In that case, it is useful if we can see the return code
of the target syscall.
Link: http://lkml.kernel.org/r/147335074530.12462.4526186083406015005.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The hwlat tracer uses tr->max_latency, and if it's the only tracer enabled
that uses it, the build will fail. Add max_latency and its file when the
hwlat tracer is enabled.
Link: http://lkml.kernel.org/r/d6c3b7eb-ba95-1ffa-0453-464e1e24262a@infradead.org
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This work adds BPF_CALL_<n>() macros and converts all the eBPF helper functions
to use them, in a similar fashion like we do with SYSCALL_DEFINE<n>() macros
that are used today. Motivation for this is to hide all the register handling
and all necessary casts from the user, so that it is done automatically in the
background when adding a BPF_CALL_<n>() call.
This makes current helpers easier to review, eases to write future helpers,
avoids getting the casting mess wrong, and allows for extending all helpers at
once (f.e. build time checks, etc). It also helps detecting more easily in
code reviews that unused registers are not instrumented in the code by accident,
breaking compatibility with existing programs.
BPF_CALL_<n>() internals are quite similar to SYSCALL_DEFINE<n>() ones with some
fundamental differences, for example, for generating the actual helper function
that carries all u64 regs, we need to fill unused regs, so that we always end up
with 5 u64 regs as an argument.
I reviewed several 0-5 generated BPF_CALL_<n>() variants of the .i results and
they look all as expected. No sparse issue spotted. We let this also sit for a
few days with Fengguang's kbuild test robot, and there were no issues seen. On
s390, it barked on the "uses dynamic stack allocation" notice, which is an old
one from bpf_perf_event_output{,_tp}() reappearing here due to the conversion
to the call wrapper, just telling that the perf raw record/frag sits on stack
(gcc with s390's -mwarn-dynamicstack), but that's all. Did various runtime tests
and they were fine as well. All eBPF helpers are now converted to use these
macros, getting rid of a good chunk of all the raw castings.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add BPF_SIZEOF() and BPF_FIELD_SIZEOF() macros to improve the code a bit
which otherwise often result in overly long bytes_to_bpf_size(sizeof())
and bytes_to_bpf_size(FIELD_SIZEOF()) lines. So place them into a macro
helper instead. Moreover, we currently have a BUILD_BUG_ON(BPF_FIELD_SIZEOF())
check in convert_bpf_extensions(), but we should rather make that generic
as well and add a BUILD_BUG_ON() test in all BPF_SIZEOF()/BPF_FIELD_SIZEOF()
users to detect any rewriter size issues at compile time. Note, there are
currently none, but we want to assert that it stays this way.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce BPF_PROG_TYPE_PERF_EVENT programs that can be attached to
HW and SW perf events (PERF_TYPE_HARDWARE and PERF_TYPE_SOFTWARE
correspondingly in uapi/linux/perf_event.h)
The program visible context meta structure is
struct bpf_perf_event_data {
struct pt_regs regs;
__u64 sample_period;
};
which is accessible directly from the program:
int bpf_prog(struct bpf_perf_event_data *ctx)
{
... ctx->sample_period ...
... ctx->regs.ip ...
}
The bpf verifier rewrites the accesses into kernel internal
struct bpf_perf_event_data_kern which allows changing
struct perf_sample_data without affecting bpf programs.
New fields can be added to the end of struct bpf_perf_event_data
in the future.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
As NMIs can also cause latency when interrupts are disabled, the hwlat
detectory has no way to know if the latency it detects is from an NMI or an
SMI or some other hardware glitch.
As ftrace_nmi_enter/exit() funtions are no longer used (except for sh, which
isn't supported anymore), I converted those to "arch_ftrace_nmi_enter/exit"
and use ftrace_nmi_enter/exit() to check if hwlat detector is tracing or
not, and if so, it calls into the hwlat utility.
Since the hwlat detector only has a single kthread that is spinning with
interrupts disabled, it marks what CPU it is on, and if the NMI callback
happens on that CPU, it records the time spent in that NMI. This is added to
the output that is generated by the hwlat detector as:
#3 inner/outer(us): 9/9 ts:1470836488.206734548
#4 inner/outer(us): 0/8 ts:1470836497.140808588
#5 inner/outer(us): 0/6 ts:1470836499.140825168 nmi-total:5 nmi-count:1
#6 inner/outer(us): 9/9 ts:1470836501.140841748
All time is still tracked in microseconds.
The NMI information is only shown when an NMI occurred during the sample.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Instead of having the hwlat detector thread stay on one CPU, have it migrate
across all the CPUs specified by tracing_cpumask. If the user modifies the
thread's CPU affinity, the migration will stop until the next instance that
the tracer is instantiated. The migration happens at the end of each window
(period).
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The hardware latency tracer has been in the PREEMPT_RT patch for some time.
It is used to detect possible SMIs or any other hardware interruptions that
the kernel is unaware of. Note, NMIs may also be detected, but that may be
good to note as well.
The logic is pretty simple. It simply creates a thread that spins on a
single CPU for a specified amount of time (width) within a periodic window
(window). These numbers may be adjusted by their cooresponding names in
/sys/kernel/tracing/hwlat_detector/
The defaults are window = 1000000 us (1 second)
width = 500000 us (1/2 second)
The loop consists of:
t1 = trace_clock_local();
t2 = trace_clock_local();
Where trace_clock_local() is a variant of sched_clock().
The difference of t2 - t1 is recorded as the "inner" timestamp and also the
timestamp t1 - prev_t2 is recorded as the "outer" timestamp. If either of
these differences are greater than the time denoted in
/sys/kernel/tracing/tracing_thresh then it records the event.
When this tracer is started, and tracing_thresh is zero, it changes to the
default threshold of 10 us.
The hwlat tracer in the PREEMPT_RT patch was originally written by
Jon Masters. I have modified it quite a bit and turned it into a
tracer.
Based-on-code-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The subtime is used only for function profiler with function graph
tracer enabled. Move the definition of subtime under
CONFIG_FUNCTION_PROFILER to reduce the memory usage. Also move the
initialization of subtime into the graph entry callback.
Link: http://lkml.kernel.org/r/20160831025529.24018-1-namhyung@kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It missed to handle TRACE_BPUTS so messages recorded by trace_bputs()
will be shown with symbol info unnecessarily.
You can see it with the trace_printk sample code:
# cd /sys/kernel/tracing/
# echo sys_sync > set_graph_function
# echo 1 > options/sym-offset
# echo function_graph > current_tracer
Note that the sys_sync filter was there to prevent recording other
functions and the sym-offset option was needed since the first message
was called from a module init function so kallsyms doesn't have the
symbol and omitted in the output.
# cd ~/build/kernel
# insmod samples/trace_printk/trace-printk.ko
# cd -
# head trace
Before:
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
1) | /* 0xffffffffa0002000: This is a static string that will use trace_bputs */
1) | /* This is a dynamic string that will use trace_puts */
1) | /* trace_printk_irq_work+0x5/0x7b [trace_printk]: (irq) This is a static string that will use trace_bputs */
1) | /* (irq) This is a dynamic string that will use trace_puts */
1) | /* (irq) This is a static string that will use trace_bprintk() */
1) | /* (irq) This is a dynamic string that will use trace_printk */
After:
# tracer: function_graph
#
# CPU DURATION FUNCTION CALLS
# | | | | | | |
1) | /* This is a static string that will use trace_bputs */
1) | /* This is a dynamic string that will use trace_puts */
1) | /* (irq) This is a static string that will use trace_bputs */
1) | /* (irq) This is a dynamic string that will use trace_puts */
1) | /* (irq) This is a static string that will use trace_bprintk() */
1) | /* (irq) This is a dynamic string that will use trace_printk */
Link: http://lkml.kernel.org/r/20160901024354.13720-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When function graph tracing is enabled for a function, ftrace modifies
the stack by replacing the original return address with the address of a
hook function (return_to_handler).
Stack unwinders need a way to get the original return address. Add an
arch-independent helper function for that named ftrace_graph_ret_addr().
This adds two variations of the function: one depends on
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, and the other relies on an index state
variable.
The former is recommended because, in some cases, the latter can cause
problems when the unwinder skips stack frames. It can get out of sync
with the ret_stack index and wrong addresses can be reported for the
stack trace.
Once all arches have been ported to use
HAVE_FUNCTION_GRAPH_RET_ADDR_PTR, we can get rid of the distinction.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/36bd90f762fc5e5af3929e3797a68a64906421cf.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Storing this value will help prevent unwinders from getting out of sync
with the function graph tracer ret_stack. Now instead of needing a
stateful iterator, they can compare the return address pointer to find
the right ret_stack entry.
Note that an array of 50 ftrace_ret_stack structs is allocated for every
task. So when an arch implements this, it will add either 200 or 400
bytes of memory usage per task (depending on whether it's a 32-bit or
64-bit platform).
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This saves some memory when HAVE_FUNCTION_GRAPH_FP_TEST isn't defined.
On x86_64 with newer versions of gcc which have -mfentry, it saves 400
bytes per task.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/5c7747d9ea7b5cb47ef0a8ce8a6cea6bf7aa94bf.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Make HAVE_FUNCTION_GRAPH_FP_TEST a normal define, independent from
kconfig. This removes some config file pollution and simplifies the
checking for the fp test.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2c4e5f05054d6d367f702fd153af7a0109dd5c81.1471607358.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change kprobe/uprobe-tracer to show the arguments type-casted
with u8/u16/u32/u64 in decimal digits instead of hexadecimal.
To minimize compatibility issue, the arguments without type
casting are typed by x64 (or x32 for 32bit arch) by default.
Note: all arguments set by old perf probe without types are
shown in decimal by default.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naohiro Aota <naohiro.aota@hgst.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/147151076135.12957.14684546093034343894.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add README entries for kprobe-events and uprobe-events.
This allows user to check what options can be acceptable
for running kernel.
E.g. perf tools can choose correct types for the kernel.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naohiro Aota <naohiro.aota@hgst.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/147151069524.12957.12957179170304055028.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add x8/x16/x32/x64 for hexadecimal type casting to kprobe/uprobe event
tracer.
These type casts can be used for integer arguments for explicitly
showing them in hexadecimal digits in formatted text.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naohiro Aota <naohiro.aota@hgst.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/147151067029.12957.11591314629326414783.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Minor overlapping changes for both merge conflicts.
Resolution work done by Stephen Rothwell was used
as a reference.
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 288dab8a35 ("block: add a separate operation type for secure
erase") split REQ_OP_SECURE_ERASE from REQ_OP_DISCARD without considering
all the places REQ_OP_DISCARD was being used to mean either. Fix those.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: 288dab8a35 ("block: add a separate operation type for secure erase")
Signed-off-by: Jens Axboe <axboe@fb.com>
bpf_get_prandom_u32() was initially introduced for socket filters
and later requested numberous times to be added to tracing bpf programs
for the same reason as in socket filters: to be able to randomly
select incoming events.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds a bpf helper that's similar to the skb_in_cgroup helper to check
whether the probe is currently executing in the context of a specific
subset of the cgroupsv2 hierarchy. It does this based on membership test
for a cgroup arraymap. It is invalid to call this in an interrupt, and
it'll return an error. The helper is primarily to be used in debugging
activities for containers, where you may have multiple programs running in
a given top-level "container".
Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 63a4cc2486, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.
No intended functional changes in this commit.
Signed-off-by: Jens Axboe <axboe@fb.com>
. Move the suppressing of the __builtin_return_address >0 warning to the
tracing directory only.
. metag recordmcount fix for newer glibc's
. Two tracing histogram fixes that were reported by KASAN
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Merge tag 'trace-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"A few updates and fixes:
- move the suppressing of the __builtin_return_address >0 warning to
the tracing directory only.
- metag recordmcount fix for newer glibc's
- two tracing histogram fixes that were reported by KASAN"
* tag 'trace-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix use-after-free in hist_register_trigger()
tracing: Fix use-after-free in hist_unreg_all/hist_enable_unreg_all
Makefile: Mute warning for __builtin_return_address(>0) for tracing only
ftrace/recordmcount: Work around for addition of metag magic but not relocations
While running tools/testing/selftests test suite with KASAN, Dmitry
Vyukov hit the following use-after-free report:
==================================================================
BUG: KASAN: use-after-free in hist_unreg_all+0x1a1/0x1d0 at addr
ffff880031632cc0
Read of size 8 by task ftracetest/7413
==================================================================
BUG kmalloc-128 (Not tainted): kasan: bad access detected
------------------------------------------------------------------
This fixes the problem, along with the same problem in
hist_enable_unreg_all().
Link: http://lkml.kernel.org/r/c3d05b79e42555b6e36a3a99aae0e37315ee5304.1467247517.git.tom.zanussi@linux.intel.com
Cc: Dmitry Vyukov <dvyukov@google.com>
[Copied Steve's hist_enable_unreg_all() fix to hist_unreg_all()]
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
With the latest gcc compilers, they give a warning if
__builtin_return_address() parameter is greater than 0. That is because if
it is used by a function called by a top level function (or in the case of
the kernel, by assembly), it can try to access stack frames outside the
stack and crash the system.
The tracing system uses __builtin_return_address() of up to 2! But it is
well aware of the dangers that it may have, and has even added precautions
to protect against it (see the thunk code in arch/x86/entry/thunk*.S)
Linus originally added KBUILD_CFLAGS that would suppress the warning for the
entire kernel, as simply adding KBUILD_CFLAGS to the tracing directory
wouldn't work. The tracing directory plays a bit with the CFLAGS and
requires a little more logic.
This adds that special logic to only suppress the warning for the tracing
directory. If it is used anywhere else outside of tracing, the warning will
still be triggered.
Link: http://lkml.kernel.org/r/20160728223043.51996267@grimm.local.home
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
changes are:
. The function pid code uses the event pid filtering logic
. [ku]probe events have access to current->comm
. trace_printk now has sample code
. PCI devices now trace physical addresses
. stack tracing has less unnessary functions traced
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Merge tag 'trace-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This is mostly clean ups and small fixes. Some of the more visible
changes are:
- The function pid code uses the event pid filtering logic
- [ku]probe events have access to current->comm
- trace_printk now has sample code
- PCI devices now trace physical addresses
- stack tracing has less unnessary functions traced"
* tag 'trace-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
printk, tracing: Avoiding unneeded blank lines
tracing: Use __get_str() when manipulating strings
tracing, RAS: Cleanup on __get_str() usage
tracing: Use outer () on __get_str() definition
ftrace: Reduce size of function graph entries
tracing: Have HIST_TRIGGERS select TRACING
tracing: Using for_each_set_bit() to simplify trace_pid_write()
ftrace: Move toplevel init out of ftrace_init_tracefs()
tracing/function_graph: Fix filters for function_graph threshold
tracing: Skip more functions when doing stack tracing of events
tracing: Expose CPU physical addresses (resource values) for PCI devices
tracing: Show the preempt count of when the event was called
tracing: Add trace_printk sample code
tracing: Choose static tp_printk buffer by explicit nesting count
tracing: expose current->comm to [ku]probe events
ftrace: Have set_ftrace_pid use the bitmap like events do
tracing: Move pid_list write processing into its own function
tracing: Move the pid_list seq_file functions to be global
tracing: Move filtered_pid helper functions into trace.c
tracing: Make the pid filtering helper functions global
Pull networking updates from David Miller:
1) Unified UDP encapsulation offload methods for drivers, from
Alexander Duyck.
2) Make DSA binding more sane, from Andrew Lunn.
3) Support QCA9888 chips in ath10k, from Anilkumar Kolli.
4) Several workqueue usage cleanups, from Bhaktipriya Shridhar.
5) Add XDP (eXpress Data Path), essentially running BPF programs on RX
packets as soon as the device sees them, with the option to mirror
the packet on TX via the same interface. From Brenden Blanco and
others.
6) Allow qdisc/class stats dumps to run lockless, from Eric Dumazet.
7) Add VLAN support to b53 and bcm_sf2, from Florian Fainelli.
8) Simplify netlink conntrack entry layout, from Florian Westphal.
9) Add ipv4 forwarding support to mlxsw spectrum driver, from Ido
Schimmel, Yotam Gigi, and Jiri Pirko.
10) Add SKB array infrastructure and convert tun and macvtap over to it.
From Michael S Tsirkin and Jason Wang.
11) Support qdisc packet injection in pktgen, from John Fastabend.
12) Add neighbour monitoring framework to TIPC, from Jon Paul Maloy.
13) Add NV congestion control support to TCP, from Lawrence Brakmo.
14) Add GSO support to SCTP, from Marcelo Ricardo Leitner.
15) Allow GRO and RPS to function on macsec devices, from Paolo Abeni.
16) Support MPLS over IPV4, from Simon Horman.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1622 commits)
xgene: Fix build warning with ACPI disabled.
be2net: perform temperature query in adapter regardless of its interface state
l2tp: Correctly return -EBADF from pppol2tp_getname.
net/mlx5_core/health: Remove deprecated create_singlethread_workqueue
net: ipmr/ip6mr: update lastuse on entry change
macsec: ensure rx_sa is set when validation is disabled
tipc: dump monitor attributes
tipc: add a function to get the bearer name
tipc: get monitor threshold for the cluster
tipc: make cluster size threshold for monitoring configurable
tipc: introduce constants for tipc address validation
net: neigh: disallow transition to NUD_STALE if lladdr is unchanged in neigh_update()
MAINTAINERS: xgene: Add driver and documentation path
Documentation: dtb: xgene: Add MDIO node
dtb: xgene: Add MDIO node
drivers: net: xgene: ethtool: Use phy_ethtool_gset and sset
drivers: net: xgene: Use exported functions
drivers: net: xgene: Enable MDIO driver
drivers: net: xgene: Add backward compatibility
drivers: net: phy: xgene: Add MDIO driver
...
Pull block driver updates from Jens Axboe:
"This branch also contains core changes. I've come to the conclusion
that from 4.9 and forward, I'll be doing just a single branch. We
often have dependencies between core and drivers, and it's hard to
always split them up appropriately without pulling core into drivers
when that happens.
That said, this contains:
- separate secure erase type for the core block layer, from
Christoph.
- set of discard fixes, from Christoph.
- bio shrinking fixes from Christoph, as a followup up to the
op/flags change in the core branch.
- map and append request fixes from Christoph.
- NVMeF (NVMe over Fabrics) code from Christoph. This is pretty
exciting!
- nvme-loop fixes from Arnd.
- removal of ->driverfs_dev from Dan, after providing a
device_add_disk() helper.
- bcache fixes from Bhaktipriya and Yijing.
- cdrom subchannel read fix from Vchannaiah.
- set of lightnvm updates from Wenwei, Matias, Johannes, and Javier.
- set of drbd updates and fixes from Fabian, Lars, and Philipp.
- mg_disk error path fix from Bart.
- user notification for failed device add for loop, from Minfei.
- NVMe in general:
+ NVMe delay quirk from Guilherme.
+ SR-IOV support and command retry limits from Keith.
+ fix for memory-less NUMA node from Masayoshi.
+ use UINT_MAX for discard sectors, from Minfei.
+ cancel IO fixes from Ming.
+ don't allocate unused major, from Neil.
+ error code fixup from Dan.
+ use constants for PSDT/FUSE from James.
+ variable init fix from Jay.
+ fabrics fixes from Ming, Sagi, and Wei.
+ various fixes"
* 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits)
nvme/pci: Provide SR-IOV support
nvme: initialize variable before logical OR'ing it
block: unexport various bio mapping helpers
scsi/osd: open code blk_make_request
target: stop using blk_make_request
block: simplify and export blk_rq_append_bio
block: ensure bios return from blk_get_request are properly initialized
virtio_blk: use blk_rq_map_kern
memstick: don't allow REQ_TYPE_BLOCK_PC requests
block: shrink bio size again
block: simplify and cleanup bvec pool handling
block: get rid of bio_rw and READA
block: don't ignore -EOPNOTSUPP blkdev_issue_write_same
block: introduce BLKDEV_DISCARD_ZERO to fix zeroout
NVMe: don't allocate unused nvme_major
nvme: avoid crashes when node 0 is memoryless node.
nvme: Limit command retries
loop: Make user notify for adding loop device failed
nvme-loop: fix nvme-loop Kconfig dependencies
nvmet: fix return value check in nvmet_subsys_alloc()
...
Pull core block updates from Jens Axboe:
- the big change is the cleanup from Mike Christie, cleaning up our
uses of command types and modified flags. This is what will throw
some merge conflicts
- regression fix for the above for btrfs, from Vincent
- following up to the above, better packing of struct request from
Christoph
- a 2038 fix for blktrace from Arnd
- a few trivial/spelling fixes from Bart Van Assche
- a front merge check fix from Damien, which could cause issues on
SMR drives
- Atari partition fix from Gabriel
- convert cfq to highres timers, since jiffies isn't granular enough
for some devices these days. From Jan and Jeff
- CFQ priority boost fix idle classes, from me
- cleanup series from Ming, improving our bio/bvec iteration
- a direct issue fix for blk-mq from Omar
- fix for plug merging not involving the IO scheduler, like we do for
other types of merges. From Tahsin
- expose DAX type internally and through sysfs. From Toshi and Yigal
* 'for-4.8/core' of git://git.kernel.dk/linux-block: (76 commits)
block: Fix front merge check
block: do not merge requests without consulting with io scheduler
block: Fix spelling in a source code comment
block: expose QUEUE_FLAG_DAX in sysfs
block: add QUEUE_FLAG_DAX for devices to advertise their DAX support
Btrfs: fix comparison in __btrfs_map_block()
block: atari: Return early for unsupported sector size
Doc: block: Fix a typo in queue-sysfs.txt
cfq-iosched: Charge at least 1 jiffie instead of 1 ns
cfq-iosched: Fix regression in bonnie++ rewrite performance
cfq-iosched: Convert slice_resid from u64 to s64
block: Convert fifo_time from ulong to u64
blktrace: avoid using timespec
block/blk-cgroup.c: Declare local symbols static
block/bio-integrity.c: Add #include "blk.h"
block/partition-generic.c: Remove a set-but-not-used variable
block: bio: kill BIO_MAX_SIZE
cfq-iosched: temporarily boost queue priority for idle classes
block: drbd: avoid to use BIO_MAX_SIZE
block: bio: remove BIO_MAX_SECTORS
...
This allows user memory to be written to during the course of a kprobe.
It shouldn't be used to implement any kind of security mechanism
because of TOC-TOU attacks, but rather to debug, divert, and
manipulate execution of semi-cooperative processes.
Although it uses probe_kernel_write, we limit the address space
the probe can write into by checking the space with access_ok.
We do this as opposed to calling copy_to_user directly, in order
to avoid sleeping. In addition we ensure the threads's current fs
/ segment is USER_DS and the thread isn't exiting nor a kernel thread.
Given this feature is meant for experiments, and it has a risk of
crashing the system, and running programs, we print a warning on
when a proglet that attempts to use this helper is installed,
along with the pid and process name.
Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
kernel/trace/bpf_trace.c: In function 'bpf_event_output':
kernel/trace/bpf_trace.c:312: error: unknown field 'next' specified in initializer
kernel/trace/bpf_trace.c:312: warning: missing braces around initializer
kernel/trace/bpf_trace.c:312: warning: (near initialization for 'raw.frag.<anonymous>')
Fixes: 555c8a8623 ("bpf: avoid stack copy and use skb ctx for event output")
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This work addresses a couple of issues bpf_skb_event_output()
helper currently has: i) We need two copies instead of just a
single one for the skb data when it should be part of a sample.
The data can be non-linear and thus needs to be extracted via
bpf_skb_load_bytes() helper first, and then copied once again
into the ring buffer slot. ii) Since bpf_skb_load_bytes()
currently needs to be used first, the helper needs to see a
constant size on the passed stack buffer to make sure BPF
verifier can do sanity checks on it during verification time.
Thus, just passing skb->len (or any other non-constant value)
wouldn't work, but changing bpf_skb_load_bytes() is also not
the proper solution, since the two copies are generally still
needed. iii) bpf_skb_load_bytes() is just for rather small
buffers like headers, since they need to sit on the limited
BPF stack anyway. Instead of working around in bpf_skb_load_bytes(),
this work improves the bpf_skb_event_output() helper to address
all 3 at once.
We can make use of the passed in skb context that we have in
the helper anyway, and use some of the reserved flag bits as
a length argument. The helper will use the new __output_custom()
facility from perf side with bpf_skb_copy() as callback helper
to walk and extract the data. It will pass the data for setup
to bpf_event_output(), which generates and pushes the raw record
with an additional frag part. The linear data used in the first
frag of the record serves as programmatically defined meta data
passed along with the appended sample.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Split the bpf_perf_event_output() helper as a preparation into
two parts. The new bpf_perf_event_output() will prepare the raw
record itself and test for unknown flags from BPF trace context,
where the __bpf_perf_event_output() does the core work. The
latter will be reused later on from bpf_event_output() directly.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support for non-linear data on raw records. It
extends raw records to have one or multiple fragments that will
be written linearly into the ring slot, where each fragment can
optionally have a custom callback handler to walk and extract
complex, possibly non-linear data.
If a callback handler is provided for a fragment, then the new
__output_custom() will be used instead of __output_copy() for
the perf_output_sample() part. perf_prepare_sample() does all
the size calculation only once, so perf_output_sample() doesn't
need to redo the same work anymore, meaning real_size and padding
will be cached in the raw record. The raw record becomes 32 bytes
in size without holes; to not increase it further and to avoid
doing unnecessary recalculations in fast-path, we can reuse
next pointer of the last fragment, idea here is borrowed from
ZERO_OR_NULL_PTR(), which should keep the perf_output_sample()
path for PERF_SAMPLE_RAW minimal.
This facility is needed for BPF's event output helper as a first
user that will, in a follow-up, add an additional perf_raw_frag
to its perf_raw_record in order to be able to more efficiently
dump skb context after a linear head meta data related to it.
skbs can be non-linear and thus need a custom output function to
dump buffers. Currently, the skb data needs to be copied twice;
with the help of __output_custom() this work only needs to be
done once. Future users could be things like XDP/BPF programs
that work on different context though and would thus also have
a different callback function.
The few users of raw records are adapted to initialize their frag
data from the raw record itself, no change in behavior for them.
The code is based upon a PoC diff provided by Peter Zijlstra [1].
[1] http://thread.gmane.org/gmane.linux.network/421294
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
over time there were multiple requests to access different data
structures and fields of task_struct current, so finally add
the helper to access 'current' as-is. Tracing bpf programs will do
the rest of walking the pointers via bpf_probe_read().
Note that current can be null and bpf program has to deal it with,
but even dumb passing null into bpf_probe_read() is still safe.
Suggested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently ftrace_graph_ent{,_entry} and ftrace_graph_ret{,_entry} struct
can have padding bytes at the end due to alignment in 64-bit data type.
As these data are recorded so frequently, those paddings waste
non-negligible space. As the ring buffer maintains alignment properly
for each architecture, just to remove the extra padding using 'packed'
attribute.
ftrace_graph_ent_entry: 24 -> 20
ftrace_graph_ret_entry: 48 -> 44
Also I moved the 'overrun' field in struct ftrace_graph_ret to minimize
the padding in the middle.
Tested on x86_64 only.
Link: http://lkml.kernel.org/r/1467197808-13578-1-git-send-email-namhyung@kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The kbuild test robot reported a compile error if HIST_TRIGGERS was
enabled but nothing else that selected TRACING was configured in.
HIST_TRIGGERS should directly select it and not rely on anything else
to do it.
Link: http://lkml.kernel.org/r/57791866.8080505@linux.intel.com
Reported-by: kbuild test robot <fennguang.wu@intel.com>
Fixes: 7ef224d1d0 ("tracing: Add 'hist' event trigger command")
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Commit 345ddcc882 ("ftrace: Have set_ftrace_pid use the bitmap like events
do") placed ftrace_init_tracefs into the instance creation, and encapsulated
the top level updating with an if conditional, as the top level only gets
updated at boot up. Unfortunately, this triggers section mismatch errors as
the init functions are called from a function that can be called later, and
the section mismatch logic is unaware of the if conditional that would
prevent it from happening at run time.
To make everyone happy, create a separate ftrace_init_tracefs_toplevel()
routine that only gets called by init functions, and this will be what calls
other init functions for the toplevel directory.
Link: http://lkml.kernel.org/r/20160704102139.19cbc0d9@gandalf.local.home
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 345ddcc882 ("ftrace: Have set_ftrace_pid use the bitmap like events do")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Follow-up commit to 1e33759c78 ("bpf, trace: add BPF_F_CURRENT_CPU
flag for bpf_perf_event_output") to add the same functionality into
bpf_perf_event_read() helper. The split of index into flags and index
component is also safe here, since such large maps are rejected during
map allocation time.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently have two invocations, which is unnecessary. Fetch it only
once and use the smp_processor_id() variant, so we also get preemption
checks along with it when DEBUG_PREEMPT is set.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some minor cleanups: i) Remove the unlikely() from fd array map lookups
and let the CPU branch predictor do its job, scenarios where there is not
always a map entry are very well valid. ii) Move the attribute type check
in the bpf_perf_event_read() helper a bit earlier so it's consistent wrt
checks with bpf_perf_event_output() helper as well. iii) remove some
comments that are self-documenting in kprobe_prog_is_valid_access() and
therefore make it consistent to tp_prog_is_valid_access() as well.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several cases of overlapping changes, except the packet scheduler
conflicts which deal with the addition of the free list parameter
to qdisc_enqueue().
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
"I've been traveling so this accumulates more than week or so of bug
fixing. It perhaps looks a little worse than it really is.
1) Fix deadlock in ath10k driver, from Ben Greear.
2) Increase scan timeout in iwlwifi, from Luca Coelho.
3) Unbreak STP by properly reinjecting STP packets back into the
stack. Regression fix from Ido Schimmel.
4) Mediatek driver fixes (missing malloc failure checks, leaking of
scratch memory, wrong indexing when mapping TX buffers, etc.) from
John Crispin.
5) Fix endianness bug in icmpv6_err() handler, from Hannes Frederic
Sowa.
6) Fix hashing of flows in UDP in the ruseport case, from Xuemin Su.
7) Fix netlink notifications in ovs for tunnels, delete link messages
are never emitted because of how the device registry state is
handled. From Nicolas Dichtel.
8) Conntrack module leaks kmemcache on unload, from Florian Westphal.
9) Prevent endless jump loops in nft rules, from Liping Zhang and
Pablo Neira Ayuso.
10) Not early enough spinlock initialization in mlx4, from Eric
Dumazet.
11) Bind refcount leak in act_ipt, from Cong WANG.
12) Missing RCU locking in HTB scheduler, from Florian Westphal.
13) Several small MACSEC bug fixes from Sabrina Dubroca (missing RCU
barrier, using heap for SG and IV, and erroneous use of async flag
when allocating AEAD conext.)
14) RCU handling fix in TIPC, from Ying Xue.
15) Pass correct protocol down into ipv4_{update_pmtu,redirect}() in
SIT driver, from Simon Horman.
16) Socket timer deadlock fix in TIPC from Jon Paul Maloy.
17) Fix potential deadlock in team enslave, from Ido Schimmel.
18) Memory leak in KCM procfs handling, from Jiri Slaby.
19) ESN generation fix in ipv4 ESP, from Herbert Xu.
20) Fix GFP_KERNEL allocations with locks held in act_ife, from Cong
WANG.
21) Use after free in netem, from Eric Dumazet.
22) Uninitialized last assert time in multicast router code, from Tom
Goff.
23) Skip raw sockets in sock_diag destruction broadcast, from Willem
de Bruijn.
24) Fix link status reporting in thunderx, from Sunil Goutham.
25) Limit resegmentation of retransmit queue so that we do not
retransmit too large GSO frames. From Eric Dumazet.
26) Delay bpf program release after grace period, from Daniel
Borkmann"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (141 commits)
openvswitch: fix conntrack netlink event delivery
qed: Protect the doorbell BAR with the write barriers.
neigh: Explicitly declare RCU-bh read side critical section in neigh_xmit()
e1000e: keep VLAN interfaces functional after rxvlan off
cfg80211: fix proto in ieee80211_data_to_8023 for frames without LLC header
qlcnic: use the correct ring in qlcnic_83xx_process_rcv_ring_diag()
bpf, perf: delay release of BPF prog after grace period
net: bridge: fix vlan stats continue counter
tcp: do not send too big packets at retransmit time
ibmvnic: fix to use list_for_each_safe() when delete items
net: thunderx: Fix TL4 configuration for secondary Qsets
net: thunderx: Fix link status reporting
net/mlx5e: Reorganize ethtool statistics
net/mlx5e: Fix number of PFC counters reported to ethtool
net/mlx5e: Prevent adding the same vxlan port
net/mlx5e: Check for BlueFlame capability before allocating SQ uar
net/mlx5e: Change enum to better reflect usage
net/mlx5: Add ConnectX-5 PCIe 4.0 to list of supported devices
net/mlx5: Update command strings
net: marvell: Add separate config ANEG function for Marvell 88E1111
...
Function graph tracer currently ignores filters if tracing_thresh is set.
For example, even if set_ftrace_pid is set, then its ignored if tracing_thresh
set, resulting in all processes being traced.
To fix this, we reuse the same entry function as when tracing_thresh is not
set and do everything as in the regular case except for writing the function entry
to the ring buffer.
Link: http://lkml.kernel.org/r/1466228694-2677-1-git-send-email-agnel.joel@gmail.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <agnel.joel@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
# echo 1 > options/stacktrace
# echo 1 > events/sched/sched_switch/enable
# cat trace
<idle>-0 [002] d..2 1982.525169: <stack trace>
=> save_stack_trace
=> __ftrace_trace_stack
=> trace_buffer_unlock_commit_regs
=> event_trigger_unlock_commit
=> trace_event_buffer_commit
=> trace_event_raw_event_sched_switch
=> __schedule
=> schedule
=> schedule_preempt_disabled
=> cpu_startup_entry
=> start_secondary
The above shows that we are seeing 6 functions before ever making it to the
caller of the sched_switch event.
# echo stacktrace > events/sched/sched_switch/trigger
# cat trace
<idle>-0 [002] d..3 2146.335208: <stack trace>
=> trace_event_buffer_commit
=> trace_event_raw_event_sched_switch
=> __schedule
=> schedule
=> schedule_preempt_disabled
=> cpu_startup_entry
=> start_secondary
The stacktrace trigger isn't as bad, because it adds its own skip to the
stacktracing, but still has two events extra.
One issue is that if the stacktrace passes its own "regs" then there should
be no addition to the skip, as the regs will not include the functions being
called. This was an issue that was fixed by commit 7717c6be69 ("tracing:
Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()" as adding
the skip number for kprobes made the probes not have any stack at all.
But since this is only an issue when regs is being used, a skip should be
added if regs is NULL. Now we have:
# echo 1 > options/stacktrace
# echo 1 > events/sched/sched_switch/enable
# cat trace
<idle>-0 [000] d..2 1297.676333: <stack trace>
=> __schedule
=> schedule
=> schedule_preempt_disabled
=> cpu_startup_entry
=> rest_init
=> start_kernel
=> x86_64_start_reservations
=> x86_64_start_kernel
# echo stacktrace > events/sched/sched_switch/trigger
# cat trace
<idle>-0 [002] d..3 1370.759745: <stack trace>
=> __schedule
=> schedule
=> schedule_preempt_disabled
=> cpu_startup_entry
=> start_secondary
And kprobes are not touched.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Previously, mmio_print_pcidev() put "user" addresses in the trace buffer.
On most architectures, these are the same as CPU physical addresses, but on
microblaze, mips, powerpc, and sparc, they may be something else, typically
a raw BAR value (a bus address as opposed to a CPU address).
Always expose the CPU physical address to avoid this arch-dependent
behavior.
This change should have no user-visible effect because this file currently
depends on CONFIG_HAVE_MMIOTRACE_SUPPORT, which is only defined for x86,
and pci_resource_to_user() is a no-op on x86.
Link: http://lkml.kernel.org/r/20160511190657.5898.4248.stgit@bhelgaas-glaptop2.roam.corp.google.com
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Because tracepoint callbacks are done with preemption enabled, the trace
events are always called with preempt disable due to the
rcu_read_lock_sched_notrace() in __DO_TRACE(). This causes the preempt count
shown in the recorded trace event to be inaccurate. It is always one more
that what the preempt_count was when the tracepoint was called.
If CONFIG_PREEMPT is enabled, subtract 1 from the preempt_count before
recording it in the trace buffer.
Link: http://lkml.kernel.org/r/20160525132537.GA10808@linutronix.de
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently, the trace_printk code chooses which static buffer to use based
on what type of atomic context (NMI, IRQ, etc) it's in. Simplify the
code and make it more robust: simply count the nesting depth and choose
a buffer based on the current nesting depth.
The new code will only drop an event if we nest more than 4 deep,
and the old code was guaranteed to malfunction if that happened.
Link: http://lkml.kernel.org/r/07ab03aecfba25fcce8f9a211b14c9c5e2865c58.1464289095.git.luto@kernel.org
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
ftrace is very quick to give up on saving the task command line (see
`trace_save_cmdline()`). The workaround for events which really care
about the command line is to explicitly assign it as part of the entry.
However, this doesn't work for kprobe events, as there's no
straightforward way to get access to current->comm. Add a kprobe/uprobe
event variable $comm which provides exactly that.
Link: http://lkml.kernel.org/r/f59b472033b943a370f5f48d0af37698f409108f.1465435894.git.osandov@fb.com
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Convert set_ftrace_pid to use the bitmap like set_event_pid does. This
allows for instances to use the pid filtering as well, and will allow for
function-fork option to set if the children of a traced function should be
traced or not.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The addition of PIDs into a pid_list via the write operation of
set_event_pid is a bit complex. The same operation will be needed for
function tracing pids. Move the code into its own generic function in
trace.c, so that we can avoid duplication of this code.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
To allow other aspects of ftrace to use the pid_list logic, we need to reuse
the seq_file functions. Making the generic part into functions that can be
called by other files will help in this regard.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As the filtered_pid functions are going to be used by function tracer as
well as trace_events, move the code into the generic trace.c file.
The functions moved are:
trace_find_filtered_pid()
trace_ignore_this_task()
trace_filter_add_remove_task()
Kernel Doc text was also added.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make the functions used for pid filtering global for tracing, such that the
function tracer can use the pid code as well.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If a task uses a non constant string for the format parameter in
trace_printk(), then the trace_printk_fmt variable is set to NULL. This
variable is then saved in the __trace_printk_fmt section.
The function hold_module_trace_bprintk_format() checks to see if duplicate
formats are used by modules, and reuses them if so (saves them to the list
if it is new). But this function calls lookup_format() that does a strcmp()
to the value (which is now NULL) and can cause a kernel oops.
This wasn't an issue till 3debb0a9dd ("tracing: Fix trace_printk() to print
when not using bprintk()") which added "__used" to the trace_printk_fmt
variable, and before that, the kernel simply optimized it out (no NULL value
was saved).
The fix is simply to handle the NULL pointer in lookup_format() and have the
caller ignore the value if it was NULL.
Link: http://lkml.kernel.org/r/1464769870-18344-1-git-send-email-zhengjun.xing@intel.com
Reported-by: xingzhen <zhengjun.xing@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Fixes: 3debb0a9dd ("tracing: Fix trace_printk() to print when not using bprintk()")
Cc: stable@vger.kernel.org # v3.5+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The blktrace code stores the current time in a 32-bit word in its
user interface. This is a bad idea because 32-bit seconds overflow
at some point.
We probably have until 2106 before this one overflows, as it seems
to use an 'unsigned' variable, but we should confirm that user
space treats it the same way.
Aside from this, we want to stop using 'struct timespec' here,
so I'm adding a comment about the overflow and change the code
to use timespec64 instead to make the loss of range more obvious.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
The behavior of perf event arrays are quite different from all
others as they are tightly coupled to perf event fds, f.e. shown
recently by commit e03e7ee34f ("perf/bpf: Convert perf_event_array
to use struct file") to make refcounting on perf event more robust.
A remaining issue that the current code still has is that since
additions to the perf event array take a reference on the struct
file via perf_event_get() and are only released via fput() (that
cleans up the perf event eventually via perf_event_release_kernel())
when the element is either manually removed from the map from user
space or automatically when the last reference on the perf event
map is dropped. However, this leads us to dangling struct file's
when the map gets pinned after the application owning the perf
event descriptor exits, and since the struct file reference will
in such case only be manually dropped or via pinned file removal,
it leads to the perf event living longer than necessary, consuming
needlessly resources for that time.
Relations between perf event fds and bpf perf event map fds can be
rather complex. F.e. maps can act as demuxers among different perf
event fds that can possibly be owned by different threads and based
on the index selection from the program, events get dispatched to
one of the per-cpu fd endpoints. One perf event fd (or, rather a
per-cpu set of them) can also live in multiple perf event maps at
the same time, listening for events. Also, another requirement is
that perf event fds can get closed from application side after they
have been attached to the perf event map, so that on exit perf event
map will take care of dropping their references eventually. Likewise,
when such maps are pinned, the intended behavior is that a user
application does bpf_obj_get(), puts its fds in there and on exit
when fd is released, they are dropped from the map again, so the map
acts rather as connector endpoint. This also makes perf event maps
inherently different from program arrays as described in more detail
in commit c9da161c65 ("bpf: fix clearing on persistent program
array maps").
To tackle this, map entries are marked by the map struct file that
added the element to the map. And when the last reference to that map
struct file is released from user space, then the tracked entries
are purged from the map. This is okay, because new map struct files
instances resp. frontends to the anon inode are provided via
bpf_map_new_fd() that is called when we invoke bpf_obj_get_user()
for retrieving a pinned map, but also when an initial instance is
created via map_create(). The rest is resolved by the vfs layer
automatically for us by keeping reference count on the map's struct
file. Any concurrent updates on the map slot are fine as well, it
just means that perf_event_fd_array_release() needs to delete less
of its own entires.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
similar to bpf_perf_event_output() the bpf_perf_event_read() helper
needs to check the type of the perf_event before reading the counter.
Fixes: a43eec3042 ("bpf: introduce bpf_perf_event_output() helper")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ctx structure passed into bpf programs is different depending on bpf
program type. The verifier incorrectly marked ctx->data and ctx->data_end
access based on ctx offset only. That caused loads in tracing programs
int bpf_prog(struct pt_regs *ctx) { .. ctx->ax .. }
to be incorrectly marked as PTR_TO_PACKET which later caused verifier
to reject the program that was actually valid in tracing context.
Fix this by doing program type specific matching of ctx offsets.
Fixes: 969bf05eb3 ("bpf: direct packet access")
Reported-by: Sasha Goldshtein <goldshtn@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of overloading the discard support with the REQ_SECURE flag.
Use the opportunity to rename the queue flag as well, and remove the
dead checks for this flag in the RAID 1 and RAID 10 drivers that don't
claim support for secure erase.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
In bpf_perf_event_read() and bpf_perf_event_output(), we must use
READ_ONCE() for fetching the struct file pointer, which could get
updated concurrently, so we must prevent the compiler from potential
refetching.
We already do this with tail calls for fetching the related bpf_prog,
but not so on stored perf events. Semantics for both are the same
with regards to updates.
Fixes: a43eec3042 ("bpf: introduce bpf_perf_event_output() helper")
Fixes: 35578d7984 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This adds a REQ_OP_FLUSH operation that is sent to request_fn
based drivers by the block layer's flush code, instead of
sending requests with the request->cmd_flags REQ_FLUSH bit set.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Have blktrace use the req/bio op accessor to get the REQ_OP.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
1) I forgot that I had another selftest to stress test the ftrace
instance creation. It was actually suppose to go into the 4.6
merge window, but I never committed it. I almost forgot about it
again, but noticed it was missing from your tree.
2) Soumya PN sent me a clean up patch to not disable interrupts when
taking the tasklist_lock for read, as it's unnecessary because
that lock is never taken for write in irq context.
3) Newer gcc's can cause the jump in the function_graph code to the
global ftrace_stub label to be a short jump instead of a long one.
As that jump is dynamically converted to jump to the trace code to
do function graph tracing, and that conversion expects a long jump
it can corrupt the ftrace_stub itself (it's directly after that call).
One way to prevent gcc from using a short jump is to declare the
ftrace_stub as a weak function, which we do here to keep gcc from
optimizing too much.
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Merge tag 'trace-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull motr tracing updates from Steven Rostedt:
"Three more changes.
- I forgot that I had another selftest to stress test the ftrace
instance creation. It was actually suppose to go into the 4.6
merge window, but I never committed it. I almost forgot about it
again, but noticed it was missing from your tree.
- Soumya PN sent me a clean up patch to not disable interrupts when
taking the tasklist_lock for read, as it's unnecessary because that
lock is never taken for write in irq context.
- Newer gcc's can cause the jump in the function_graph code to the
global ftrace_stub label to be a short jump instead of a long one.
As that jump is dynamically converted to jump to the trace code to
do function graph tracing, and that conversion expects a long jump
it can corrupt the ftrace_stub itself (it's directly after that
call). One way to prevent gcc from using a short jump is to
declare the ftrace_stub as a weak function, which we do here to
keep gcc from optimizing too much"
* tag 'trace-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/x86: Set ftrace_stub to weak to prevent gcc from using short jumps to it
ftrace: Don't disable irqs when taking the tasklist_lock read_lock
ftracetest: Add instance created, delete, read and enable event test
In ftrace.c inside the function alloc_retstack_tasklist() (which will be
invoked when function_graph tracing is on) the tasklist_lock is being
held as reader while iterating through a list of threads. Here the lock
is being held as reader with irqs disabled. The tasklist_lock is never
write_locked in interrupt context so it is safe to not disable interrupts
for the duration of read_lock in this block which, can be significant,
given the block of code iterates through all threads. Hence changing the
code to call read_lock() and read_unlock() instead of read_lock_irqsave()
and read_unlock_irqrestore().
A similar change was made in commits: 8063e41d2f ("tracing: Change
syscall_*regfunc() to check PF_KTHREAD and use for_each_process_thread()")'
and 3472eaa1f1 ("sched: normalize_rt_tasks(): Don't use _irqsave for
tasklist_lock, use task_rq_lock()")'
Link: http://lkml.kernel.org/r/1463500874-77480-1-git-send-email-soumya.p.n@hpe.com
Signed-off-by: Soumya PN <soumya.p.n@hpe.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Highlights:
- Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V
- Live patching support for ppc64le (also merged via livepatching.git)
Various cleanups & minor fixes from:
- Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie, Lennart
Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Michael
Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras, Rashmica Gupta,
Russell Currey, Suraj Jitindar Singh, Thiago Jung Bauermann, Valentin
Rothberg, Vipin K Parashar.
General:
- Update LMB associativity index during DLPAR add/remove from Nathan Fontenot
- Fix branching to OOL handlers in relocatable kernel from Hari Bathini
- Add support for userspace Power9 copy/paste from Chris Smart
- Always use STRICT_MM_TYPECHECKS from Michael Ellerman
- Add mask of possible MMU features from Michael Ellerman
PCI:
- Enable pass through of NVLink to guests from Alexey Kardashevskiy
- Cleanups in preparation for powernv PCI hotplug from Gavin Shan
- Don't report error in eeh_pe_reset_and_recover() from Gavin Shan
- Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan
- Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" from Guilherme G. Piccoli
- Remove the dependency on EEH struct in DDW mechanism from Guilherme G. Piccoli
selftests:
- Test cp_abort during context switch from Chris Smart
- Add several tests for transactional memory support from Rashmica Gupta
perf:
- Add support for sampling interrupt register state from Anju T
- Add support for unwinding perf-stackdump from Chandan Kumar
cxl:
- Configure the PSL for two CAPI ports on POWER8NVL from Philippe Bergheaud
- Allow initialization on timebase sync failures from Frederic Barrat
- Increase timeout for detection of AFU mmio hang from Frederic Barrat
- Handle num_of_processes larger than can fit in the SPA from Ian Munsie
- Ensure PSL interrupt is configured for contexts with no AFU IRQs from Ian Munsie
- Add kernel API to allow a context to operate with relocate disabled from Ian Munsie
- Check periodically the coherent platform function's state from Christophe Lombard
Freescale:
- Updates from Scott: "Contains 86xx fixes, minor device tree fixes, an erratum
workaround, and a kconfig dependency fix."
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Merge tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Highlights:
- Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V
- Live patching support for ppc64le (also merged via livepatching.git)
Various cleanups & minor fixes from:
- Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie,
Lennart Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring,
Michael Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras,
Rashmica Gupta, Russell Currey, Suraj Jitindar Singh, Thiago Jung
Bauermann, Valentin Rothberg, Vipin K Parashar.
General:
- Update LMB associativity index during DLPAR add/remove from Nathan
Fontenot
- Fix branching to OOL handlers in relocatable kernel from Hari Bathini
- Add support for userspace Power9 copy/paste from Chris Smart
- Always use STRICT_MM_TYPECHECKS from Michael Ellerman
- Add mask of possible MMU features from Michael Ellerman
PCI:
- Enable pass through of NVLink to guests from Alexey Kardashevskiy
- Cleanups in preparation for powernv PCI hotplug from Gavin Shan
- Don't report error in eeh_pe_reset_and_recover() from Gavin Shan
- Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan
- Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
from Guilherme G Piccoli
- Remove the dependency on EEH struct in DDW mechanism from Guilherme
G Piccoli
selftests:
- Test cp_abort during context switch from Chris Smart
- Add several tests for transactional memory support from Rashmica
Gupta
perf:
- Add support for sampling interrupt register state from Anju T
- Add support for unwinding perf-stackdump from Chandan Kumar
cxl:
- Configure the PSL for two CAPI ports on POWER8NVL from Philippe
Bergheaud
- Allow initialization on timebase sync failures from Frederic Barrat
- Increase timeout for detection of AFU mmio hang from Frederic
Barrat
- Handle num_of_processes larger than can fit in the SPA from Ian
Munsie
- Ensure PSL interrupt is configured for contexts with no AFU IRQs
from Ian Munsie
- Add kernel API to allow a context to operate with relocate disabled
from Ian Munsie
- Check periodically the coherent platform function's state from
Christophe Lombard
Freescale:
- Updates from Scott: "Contains 86xx fixes, minor device tree fixes,
an erratum workaround, and a kconfig dependency fix."
* tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (192 commits)
powerpc/86xx: Fix PCI interrupt map definition
powerpc/86xx: Move pci1 definition to the include file
powerpc/fsl: Fix build of the dtb embedded kernel images
powerpc/fsl: Fix rcpm compatible string
powerpc/fsl: Remove FSL_SOC dependency from FSL_LBC
powerpc/fsl-pci: Add a workaround for PCI 5 errata
powerpc/fsl: Fix SPI compatible on t208xrdb and t1040rdb
powerpc/powernv/npu: Add PE to PHB's list
powerpc/powernv: Fix insufficient memory allocation
powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism
Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
powerpc/eeh: Drop unnecessary label in eeh_pe_change_owner()
powerpc/eeh: Ignore handlers in eeh_pe_reset_and_recover()
powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover()
powerpc/eeh: Don't report error in eeh_pe_reset_and_recover()
Revert "powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()"
powerpc/powernv/npu: Enable NVLink pass through
powerpc/powernv/npu: Rework TCE Kill handling
powerpc/powernv/npu: Add set/unset window helpers
powerpc/powernv/ioda2: Export debug helper pe_level_printk()
...
1) With the changing of the code for filtering events by pid, from
a list of pids to a bitmask, we can now easily implement following
forks. With a new tracing option "event-fork" which, when set, will
have tasks with pids in set_event_pid, when they fork, to have their
child pids added to set_event_pid and the child will be traced as well.
Note, if "event-fork" is set and a task with its pid in set_event_pid
exits, its pid will be removed from set_event_pid
2) The addition of Tom Zanussi's hist triggers. This includes a very
thorough documentatino on how to use the hist triggers with events.
This introduces a quick and easy way to get histogram data from
events and their fields.
Some other cleanups and updates were added as well. Like Masami Hiramatsu
added test cases for the event trigger and hist triggers. Also I added
a speed up of filtering by using a temp buffer when filters are set.
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Merge tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This includes two new updates for the ftrace infrastructure.
- With the changing of the code for filtering events by pid, from a
list of pids to a bitmask, we can now easily implement following
forks. With a new tracing option "event-fork" which, when set,
will have tasks with pids in set_event_pid, when they fork, to have
their child pids added to set_event_pid and the child will be
traced as well.
Note, if "event-fork" is set and a task with its pid in
set_event_pid exits, its pid will be removed from set_event_pid
- The addition of Tom Zanussi's hist triggers. This includes a very
thorough documentatino on how to use the hist triggers with events.
This introduces a quick and easy way to get histogram data from
events and their fields.
Some other cleanups and updates were added as well. Like Masami
Hiramatsu added test cases for the event trigger and hist triggers.
Also I added a speed up of filtering by using a temp buffer when
filters are set"
* tag 'trace-v4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits)
tracing: Use temp buffer when filtering events
tracing: Remove TRACE_EVENT_FL_USE_CALL_FILTER logic
tracing: Remove unused function trace_current_buffer_lock_reserve()
tracing: Remove one use of trace_current_buffer_lock_reserve()
tracing: Have trace_buffer_unlock_commit() call the _regs version with NULL
tracing: Remove unused function trace_current_buffer_discard_commit()
tracing: Move trace_buffer_unlock_commit{_regs}() to local header
tracing: Fold filter_check_discard() into its only user
tracing: Make filter_check_discard() local
tracing: Move event_trigger_unlock_commit{_regs}() to local header
tracing: Don't use the address of the buffer array name in copy_from_user
tracing: Handle tracing_map_alloc_elts() error path correctly
tracing: Add check for NULL event field when creating hist field
tracing: checking for NULL instead of IS_ERR()
tracing: Do not inherit event-fork option for instances
tracing: Fix unsigned comparison to zero in hist trigger code
kselftests/ftrace: Add a test for log2 modifier of hist trigger
tracing: Add hist trigger 'log2' modifier
kselftests/ftrace: Add hist trigger testcases
kselftests/ftrace : Add event trigger testcases
...
Pull livepatching updates from Jiri Kosina:
- remove of our own implementation of architecture-specific relocation
code and leveraging existing code in the module loader to perform
arch-dependent work, from Jessica Yu.
The relevant patches have been acked by Rusty (for module.c) and
Heiko (for s390).
- live patching support for ppc64le, which is a joint work of Michael
Ellerman and Torsten Duwe. This is coming from topic branch that is
share between livepatching.git and ppc tree.
- addition of livepatching documentation from Petr Mladek
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: make object/func-walking helpers more robust
livepatch: Add some basic livepatch documentation
powerpc/livepatch: Add live patching support on ppc64le
powerpc/livepatch: Add livepatch stack to struct thread_info
powerpc/livepatch: Add livepatch header
livepatch: Allow architectures to specify an alternate ftrace location
ftrace: Make ftrace_location_range() global
livepatch: robustify klp_register_patch() API error checking
Documentation: livepatch: outline Elf format and requirements for patch modules
livepatch: reuse module loader code to write relocations
module: s390: keep mod_arch_specific for livepatch modules
module: preserve Elf information for livepatch modules
Elf: add livepatch-specific Elf constants
Pull networking updates from David Miller:
"Highlights:
1) Support SPI based w5100 devices, from Akinobu Mita.
2) Partial Segmentation Offload, from Alexander Duyck.
3) Add GMAC4 support to stmmac driver, from Alexandre TORGUE.
4) Allow cls_flower stats offload, from Amir Vadai.
5) Implement bpf blinding, from Daniel Borkmann.
6) Optimize _ASYNC_ bit twiddling on sockets, unless the socket is
actually using FASYNC these atomics are superfluous. From Eric
Dumazet.
7) Run TCP more preemptibly, also from Eric Dumazet.
8) Support LED blinking, EEPROM dumps, and rxvlan offloading in mlx5e
driver, from Gal Pressman.
9) Allow creating ppp devices via rtnetlink, from Guillaume Nault.
10) Improve BPF usage documentation, from Jesper Dangaard Brouer.
11) Support tunneling offloads in qed, from Manish Chopra.
12) aRFS offloading in mlx5e, from Maor Gottlieb.
13) Add RFS and RPS support to SCTP protocol, from Marcelo Ricardo
Leitner.
14) Add MSG_EOR support to TCP, this allows controlling packet
coalescing on application record boundaries for more accurate
socket timestamp sampling. From Martin KaFai Lau.
15) Fix alignment of 64-bit netlink attributes across the board, from
Nicolas Dichtel.
16) Per-vlan stats in bridging, from Nikolay Aleksandrov.
17) Several conversions of drivers to ethtool ksettings, from Philippe
Reynes.
18) Checksum neutral ILA in ipv6, from Tom Herbert.
19) Factorize all of the various marvell dsa drivers into one, from
Vivien Didelot
20) Add VF support to qed driver, from Yuval Mintz"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1649 commits)
Revert "phy dp83867: Fix compilation with CONFIG_OF_MDIO=m"
Revert "phy dp83867: Make rgmii parameters optional"
r8169: default to 64-bit DMA on recent PCIe chips
phy dp83867: Make rgmii parameters optional
phy dp83867: Fix compilation with CONFIG_OF_MDIO=m
bpf: arm64: remove callee-save registers use for tmp registers
asix: Fix offset calculation in asix_rx_fixup() causing slow transmissions
switchdev: pass pointer to fib_info instead of copy
net_sched: close another race condition in tcf_mirred_release()
tipc: fix nametable publication field in nl compat
drivers: net: Don't print unpopulated net_device name
qed: add support for dcbx.
ravb: Add missing free_irq() calls to ravb_close()
qed: Remove a stray tab
net: ethernet: fec-mpc52xx: use phy_ethtool_{get|set}_link_ksettings
net: ethernet: fec-mpc52xx: use phydev from struct net_device
bpf, doc: fix typo on bpf_asm descriptions
stmmac: hardware TX COE doesn't work when force_thresh_dma_mode is set
net: ethernet: fs-enet: use phy_ethtool_{get|set}_link_ksettings
net: ethernet: fs-enet: use phydev from struct net_device
...
Pull core block layer updates from Jens Axboe:
"This is the core block IO changes for this merge window. Nothing
earth shattering in here, it's mostly just fixes. In detail:
- Fix for a long standing issue where wrong ordering in blk-mq caused
order_to_size() to spew a warning. From Bart.
- Async discard support from Christoph. Basically just splitting our
sync interface into a submit + wait part.
- Add a cleaner interface for flagging whether a device has a write
back cache or not. We've previously overloaded blk_queue_flush()
with this, but let's make it more explicit. Drivers cleaned up and
updated in the drivers pull request. From me.
- Fix for a double check for whether IO accounting is enabled or not.
From Michael Callahan.
- Fix for the async discard from Mike Snitzer, reinstating the early
EOPNOTSUPP return if the device doesn't support discards.
- Also from Mike, export bio_inc_remaining() so dm can drop it's
private copy of it.
- From Ming Lin, add support for passing in an offset for request
payloads.
- Tag function export from Sagi, which will be used in NVMe in the
drivers pull.
- Two blktrace related fixes from Shaohua.
- Propagate NOMERGE flag when making a request from a bio, also from
Shaohua.
- An optimization to not parse cgroup paths in blk-throttle, if we
don't need to. From Shaohua"
* 'for-4.7/core' of git://git.kernel.dk/linux-block:
blk-mq: fix undefined behaviour in order_to_size()
blk-throttle: don't parse cgroup path if trace isn't enabled
blktrace: add missed mask name
blktrace: delete garbage for message trace
block: make bio_inc_remaining() interface accessible again
block: reinstate early return of -EOPNOTSUPP from blkdev_issue_discard
block: Minor blk_account_io_start usage cleanup
block: add __blkdev_issue_discard
block: remove struct bio_batch
block: copy NOMERGE flag from bio to request
block: add ability to flag write back caching on a device
blk-mq: Export tagset iter function
block: add offset in blk_add_request_payload()
writeback: Fix performance regression in wb_over_bg_thresh()
unsigned numbers in the ring-buffer code.
https://bugzilla.kernel.org/show_bug.cgi?id=118001
At first I did not think this was too much of an issue, because the
overflow would be caught later when either too much data was allocated
or it would trigger RB_WARN_ON() which shuts down the ring buffer.
But looking closer into it, I found that the right settings could bypass
the checks and crash the kernel. Luckily, this is only accessible
by root.
The first fix is to convert all the variables into long, such that
we don't get into issues between 32 bit variables being assigned 64 bit
ones. This fixes the RB_WARN_ON() triggering.
The next fix is to get rid of a duplicate DIV_ROUND_UP() that when called
twice with the right value, can cause a kernel crash.
The first DIV_ROUND_UP() is to normalize the input and it is checked
against the minimum allowable value. But then DIV_ROUND_UP() is called
again, which can overflow due to the (a + b - 1)/b, logic. The first
called upped the value, the second can overflow (with the +b part).
The second call to DIV_ROUND_UP() came in via a second change a while ago
and the code is cleaned up to remove it.
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Merge tag 'trace-fixes-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing ring-buffer fixes from Steven Rostedt:
"Hao Qin reported an integer overflow possibility with signed and
unsigned numbers in the ring-buffer code.
https://bugzilla.kernel.org/show_bug.cgi?id=118001
At first I did not think this was too much of an issue, because the
overflow would be caught later when either too much data was allocated
or it would trigger RB_WARN_ON() which shuts down the ring buffer.
But looking closer into it, I found that the right settings could
bypass the checks and crash the kernel. Luckily, this is only
accessible by root.
The first fix is to convert all the variables into long, such that we
don't get into issues between 32 bit variables being assigned 64 bit
ones. This fixes the RB_WARN_ON() triggering.
The next fix is to get rid of a duplicate DIV_ROUND_UP() that when
called twice with the right value, can cause a kernel crash.
The first DIV_ROUND_UP() is to normalize the input and it is checked
against the minimum allowable value. But then DIV_ROUND_UP() is
called again, which can overflow due to the (a + b - 1)/b, logic. The
first called upped the value, the second can overflow (with the +b
part).
The second call to DIV_ROUND_UP() came in via a second change a while
ago and the code is cleaned up to remove it"
* tag 'trace-fixes-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ring-buffer: Prevent overflow of size in ring_buffer_resize()
ring-buffer: Use long for nr_pages to avoid overflow failures
- New cpufreq "schedutil" governor (making decisions based on CPU
utilization information provided by the scheduler and capable of
switching CPU frequencies right away if the underlying driver
supports that) and support for fast frequency switching in the
acpi-cpufreq driver (Rafael Wysocki).
- Consolidation of CPU frequency management on ARM platforms allowing
them to get rid of some platform-specific boilerplate code if they
are going to use the cpufreq-dt driver (Viresh Kumar, Finley Xiao,
Marc Gonzalez).
- Support for ACPI _PPC and CPU frequency limits in the intel_pstate
driver (Srinivas Pandruvada).
- Fixes and cleanups in the cpufreq core and generic governor code
(Rafael Wysocki, Sai Gurrappadi).
- intel_pstate driver optimizations and cleanups (Rafael Wysocki,
Philippe Longepe, Chen Yu, Joe Perches).
- cpufreq powernv driver fixes and cleanups (Akshay Adiga, Shilpasri
Bhat).
- cpufreq qoriq driver fixes and cleanups (Jia Hongtao).
- ACPI cpufreq driver cleanups (Viresh Kumar).
- Assorted cpufreq driver updates (Ashwin Chaugule, Geliang Tang,
Javier Martinez Canillas, Paul Gortmaker, Sudeep Holla).
- Assorted cpufreq fixes and cleanups (Joe Perches, Arnd Bergmann).
- Fixes and cleanups in the OPP (Operating Performance Points)
framework, mostly related to OPP sharing, and reorganization of
OF-dependent code in it (Viresh Kumar, Arnd Bergmann, Sudeep Holla).
- New "passive" governor for devfreq (for SoC subsystems that will
rely on someone else for the management of their power resources)
and consolidation of devfreq support for Exynos platforms, coding
style and typo fixes for devfreq (Chanwoo Choi, MyungJoo Ham).
- PM core fixes and cleanups, mostly to make it work better with the
generic power domains (genpd) framework, and updates for that
framework (Ulf Hansson, Thierry Reding, Colin Ian King).
- Intel Broxton support for the intel_idle driver (Len Brown).
- cpuidle core optimization and fix (Daniel Lezcano, Dave Gerlach).
- ARM cpuidle cleanups (Jisheng Zhang).
- Intel Kabylake support for the RAPL power capping driver (Jacob Pan).
- AVS (Adaptive Voltage Switching) rockchip-io driver update (Heiko
Stuebner).
- Updates for the cpupower tool (Arjun Sreedharan, Colin Ian King,
Mattia Dongili, Thomas Renninger).
/
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Merge tag 'pm-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
"The majority of changes go into the cpufreq subsystem this time.
To me, quite obviously, the biggest ticket item is the new "schedutil"
governor. Interestingly enough, it's the first new cpufreq governor
since the beginning of the git era (except for some out-of-the-tree
ones).
There are two main differences between it and the existing governors.
First, it uses the information provided by the scheduler directly for
making its decisions, so it doesn't have to track anything by itself.
Second, it can invoke drivers (supporting that feature) to adjust CPU
performance right away without having to spawn work items to be
executed in process context or similar. Currently, the acpi-cpufreq
driver is the only one supporting that mode of operation, but then it
is used on a large number of systems.
The "schedutil" governor as included here is very simple and mostly
regarded as a foundation for future work on the integration of the
scheduler with CPU power management (in fact, there is work in
progress on top of it already). Nevertheless it works and the
preliminary results obtained with it are encouraging.
There also is some consolidation of CPU frequency management for ARM
platforms that can add their machine IDs the the new stub dt-platdev
driver now and that will take care of creating the requisite platform
device for cpufreq-dt, so it is not necessary to do that in platform
code any more. Several ARM platforms are switched over to using this
generic mechanism.
In addition to that, the intel_pstate driver is now going to respect
CPU frequency limits set by the platform firmware (or a BMC) and
provided via the ACPI _PPC object.
The devfreq subsystem is getting a new "passive" governor for SoCs
subsystems that will depend on somebody else to manage their voltage
rails and its support for Samsung Exynos SoCs is consolidated.
The rest is support for new hardware (Intel Broxton support in
intel_idle for one example), bug fixes, optimizations and cleanups in
a number of places.
Specifics:
- New cpufreq "schedutil" governor (making decisions based on CPU
utilization information provided by the scheduler and capable of
switching CPU frequencies right away if the underlying driver
supports that) and support for fast frequency switching in the
acpi-cpufreq driver (Rafael Wysocki)
- Consolidation of CPU frequency management on ARM platforms allowing
them to get rid of some platform-specific boilerplate code if they
are going to use the cpufreq-dt driver (Viresh Kumar, Finley Xiao,
Marc Gonzalez)
- Support for ACPI _PPC and CPU frequency limits in the intel_pstate
driver (Srinivas Pandruvada)
- Fixes and cleanups in the cpufreq core and generic governor code
(Rafael Wysocki, Sai Gurrappadi)
- intel_pstate driver optimizations and cleanups (Rafael Wysocki,
Philippe Longepe, Chen Yu, Joe Perches)
- cpufreq powernv driver fixes and cleanups (Akshay Adiga, Shilpasri
Bhat)
- cpufreq qoriq driver fixes and cleanups (Jia Hongtao)
- ACPI cpufreq driver cleanups (Viresh Kumar)
- Assorted cpufreq driver updates (Ashwin Chaugule, Geliang Tang,
Javier Martinez Canillas, Paul Gortmaker, Sudeep Holla)
- Assorted cpufreq fixes and cleanups (Joe Perches, Arnd Bergmann)
- Fixes and cleanups in the OPP (Operating Performance Points)
framework, mostly related to OPP sharing, and reorganization of
OF-dependent code in it (Viresh Kumar, Arnd Bergmann, Sudeep Holla)
- New "passive" governor for devfreq (for SoC subsystems that will
rely on someone else for the management of their power resources)
and consolidation of devfreq support for Exynos platforms, coding
style and typo fixes for devfreq (Chanwoo Choi, MyungJoo Ham)
- PM core fixes and cleanups, mostly to make it work better with the
generic power domains (genpd) framework, and updates for that
framework (Ulf Hansson, Thierry Reding, Colin Ian King)
- Intel Broxton support for the intel_idle driver (Len Brown)
- cpuidle core optimization and fix (Daniel Lezcano, Dave Gerlach)
- ARM cpuidle cleanups (Jisheng Zhang)
- Intel Kabylake support for the RAPL power capping driver (Jacob
Pan)
- AVS (Adaptive Voltage Switching) rockchip-io driver update (Heiko
Stuebner)
- Updates for the cpupower tool (Arjun Sreedharan, Colin Ian King,
Mattia Dongili, Thomas Renninger)"
* tag 'pm-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (112 commits)
intel_pstate: Clean up get_target_pstate_use_performance()
intel_pstate: Use sample.core_avg_perf in get_avg_pstate()
intel_pstate: Clarify average performance computation
intel_pstate: Avoid unnecessary synchronize_sched() during initialization
cpufreq: schedutil: Make default depend on CONFIG_SMP
cpufreq: powernv: del_timer_sync when global and local pstate are equal
cpufreq: powernv: Move smp_call_function_any() out of irq safe block
intel_pstate: Clean up intel_pstate_get()
cpufreq: schedutil: Make it depend on CONFIG_SMP
cpufreq: governor: Fix handling of special cases in dbs_update()
PM / OPP: Move CONFIG_OF dependent code in a separate file
cpufreq: intel_pstate: Ignore _PPC processing under HWP
cpufreq: arm_big_little: use generic OPP functions for {init, free}_opp_table
PM / OPP: add non-OF versions of dev_pm_opp_{cpumask_, }remove_table
cpufreq: tango: Use generic platdev driver
PM / OPP: pass cpumask by reference
cpufreq: Fix GOV_LIMITS handling for the userspace governor
cpupower: fix potential memory leak
PM / devfreq: style/typo fixes
PM / devfreq: exynos: Add the detailed correlation for Exynos5422 bus
..
* pm-cpufreq: (63 commits)
intel_pstate: Clean up get_target_pstate_use_performance()
intel_pstate: Use sample.core_avg_perf in get_avg_pstate()
intel_pstate: Clarify average performance computation
intel_pstate: Avoid unnecessary synchronize_sched() during initialization
cpufreq: schedutil: Make default depend on CONFIG_SMP
cpufreq: powernv: del_timer_sync when global and local pstate are equal
cpufreq: powernv: Move smp_call_function_any() out of irq safe block
intel_pstate: Clean up intel_pstate_get()
cpufreq: schedutil: Make it depend on CONFIG_SMP
cpufreq: governor: Fix handling of special cases in dbs_update()
cpufreq: intel_pstate: Ignore _PPC processing under HWP
cpufreq: arm_big_little: use generic OPP functions for {init, free}_opp_table
cpufreq: tango: Use generic platdev driver
cpufreq: Fix GOV_LIMITS handling for the userspace governor
cpufreq: mvebu: Move cpufreq code into drivers/cpufreq/
cpufreq: dt: Kill platform-data
mvebu: Use dev_pm_opp_set_sharing_cpus() to mark OPP tables as shared
cpufreq: dt: Identify cpu-sharing for platforms without operating-points-v2
cpufreq: governor: Change confusing struct field and variable names
cpufreq: intel_pstate: Enable PPC enforcement for servers
...
If the size passed to ring_buffer_resize() is greater than MAX_LONG - BUF_PAGE_SIZE
then the DIV_ROUND_UP() will return zero.
Here's the details:
# echo 18014398509481980 > /sys/kernel/debug/tracing/buffer_size_kb
tracing_entries_write() processes this and converts kb to bytes.
18014398509481980 << 10 = 18446744073709547520
and this is passed to ring_buffer_resize() as unsigned long size.
size = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
Where DIV_ROUND_UP(a, b) is (a + b - 1)/b
BUF_PAGE_SIZE is 4080 and here
18446744073709547520 + 4080 - 1 = 18446744073709551599
where 18446744073709551599 is still smaller than 2^64
2^64 - 18446744073709551599 = 17
But now 18446744073709551599 / 4080 = 4521260802379792
and size = size * 4080 = 18446744073709551360
This is checked to make sure its still greater than 2 * 4080,
which it is.
Then we convert to the number of buffer pages needed.
nr_page = DIV_ROUND_UP(size, BUF_PAGE_SIZE)
but this time size is 18446744073709551360 and
2^64 - (18446744073709551360 + 4080 - 1) = -3823
Thus it overflows and the resulting number is less than 4080, which makes
3823 / 4080 = 0
an nr_pages is set to this. As we already checked against the minimum that
nr_pages may be, this causes the logic to fail as well, and we crash the
kernel.
There's no reason to have the two DIV_ROUND_UP() (that's just result of
historical code changes), clean up the code and fix this bug.
Cc: stable@vger.kernel.org # 3.5+
Fixes: 83f40318da ("ring-buffer: Make removal of ring buffer pages atomic")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The size variable to change the ring buffer in ftrace is a long. The
nr_pages used to update the ring buffer based on the size is int. On 64 bit
machines this can cause an overflow problem.
For example, the following will cause the ring buffer to crash:
# cd /sys/kernel/debug/tracing
# echo 10 > buffer_size_kb
# echo 8556384240 > buffer_size_kb
Then you get the warning of:
WARNING: CPU: 1 PID: 318 at kernel/trace/ring_buffer.c:1527 rb_update_pages+0x22f/0x260
Which is:
RB_WARN_ON(cpu_buffer, nr_removed);
Note each ring buffer page holds 4080 bytes.
This is because:
1) 10 causes the ring buffer to have 3 pages.
(10kb requires 3 * 4080 pages to hold)
2) (2^31 / 2^10 + 1) * 4080 = 8556384240
The value written into buffer_size_kb is shifted by 10 and then passed
to ring_buffer_resize(). 8556384240 * 2^10 = 8761737461760
3) The size passed to ring_buffer_resize() is then divided by BUF_PAGE_SIZE
which is 4080. 8761737461760 / 4080 = 2147484672
4) nr_pages is subtracted from the current nr_pages (3) and we get:
2147484669. This value is saved in a signed integer nr_pages_to_update
5) 2147484669 is greater than 2^31 but smaller than 2^32, a signed int
turns into the value of -2147482627
6) As the value is a negative number, in update_pages_handler() it is
negated and passed to rb_remove_pages() and 2147482627 pages will
be removed, which is much larger than 3 and it causes the warning
because not all the pages asked to be removed were removed.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=118001
Cc: stable@vger.kernel.org # 2.6.28+
Fixes: 7a8e76a382 ("tracing: unified trace buffer")
Reported-by: Hao Qin <QEver.cn@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
BLK_TC_NOTIFY is missed in mask_maps, so we can't print out notify or
set mask with 'notify' name.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
commit f4a1d08ce6 introduces a regression. Originally for
BLK_TN_MESSAGE, we add message in trace and return. The commit ignores
the early return and add garbage info.
Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
In netdevice.h we removed the structure in net-next that is being
changes in 'net'. In macsec.c and rtnetlink.c we have overlaps
between fixes in 'net' and the u64 attribute changes in 'net-next'.
The mlx5 conflicts have to do with vxlan support dependencies.
Signed-off-by: David S. Miller <davem@davemloft.net>
Filtering of events requires the data to be written to the ring buffer
before it can be decided to filter or not. This is because the parameters of
the filter are based on the result that is written to the ring buffer and
not on the parameters that are passed into the trace functions.
The ftrace ring buffer is optimized for writing into the ring buffer and
committing. The discard procedure used when filtering decides the event
should be discarded is much more heavy weight. Thus, using a temporary
filter when filtering events can speed things up drastically.
Without a temp buffer we have:
# trace-cmd start -p nop
# perf stat -r 10 hackbench 50
0.790706626 seconds time elapsed ( +- 0.71% )
# trace-cmd start -e all
# perf stat -r 10 hackbench 50
1.566904059 seconds time elapsed ( +- 0.27% )
# trace-cmd start -e all -f 'common_preempt_count==20'
# perf stat -r 10 hackbench 50
1.690598511 seconds time elapsed ( +- 0.19% )
# trace-cmd start -e all -f 'common_preempt_count!=20'
# perf stat -r 10 hackbench 50
1.707486364 seconds time elapsed ( +- 0.30% )
The first run above is without any tracing, just to get a based figure.
hackbench takes ~0.79 seconds to run on the system.
The second run enables tracing all events where nothing is filtered. This
increases the time by 100% and hackbench takes 1.57 seconds to run.
The third run filters all events where the preempt count will equal "20"
(this should never happen) thus all events are discarded. This takes 1.69
seconds to run. This is 10% slower than just committing the events!
The last run enables all events and filters where the filter will commit all
events, and this takes 1.70 seconds to run. The filtering overhead is
approximately 10%. Thus, the discard and commit of an event from the ring
buffer may be about the same time.
With this patch, the numbers change:
# trace-cmd start -p nop
# perf stat -r 10 hackbench 50
0.778233033 seconds time elapsed ( +- 0.38% )
# trace-cmd start -e all
# perf stat -r 10 hackbench 50
1.582102692 seconds time elapsed ( +- 0.28% )
# trace-cmd start -e all -f 'common_preempt_count==20'
# perf stat -r 10 hackbench 50
1.309230710 seconds time elapsed ( +- 0.22% )
# trace-cmd start -e all -f 'common_preempt_count!=20'
# perf stat -r 10 hackbench 50
1.786001924 seconds time elapsed ( +- 0.20% )
The first run is again the base with no tracing.
The second run is all tracing with no filtering. It is a little slower, but
that may be well within the noise.
The third run shows that discarding all events only took 1.3 seconds. This
is a speed up of 23%! The discard is much faster than even the commit.
The one downside is shown in the last run. Events that are not discarded by
the filter will take longer to add, this is due to the extra copy of the
event.
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently register functions for events will be called
through the 'reg' field of event class directly without
any check when seting up triggers.
Triggers for events that don't support register through
debug fs (events under events/ftrace are for trace-cmd to
read event format, and most of them don't have a register
function except events/ftrace/functionx) can't be enabled
at all, and an oops will be hit when setting up trigger
for those events, so just not creating them is an easy way
to avoid the oops.
Link: http://lkml.kernel.org/r/1462275274-3911-1-git-send-email-chuhu@redhat.com
Cc: stable@vger.kernel.org # 3.14+
Fixes: 85f2b08268 ("tracing: Add basic event trigger framework")
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The only user of trace_current_buffer_lock_reserve() is in the boot up self
tests. Restructure the code a little to have that code use what everything
else uses: trace_event_buffer_lock_reserve().
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There's no real difference between trace_buffer_unlock_commit() and
trace_buffer_unlock_commit_regs() except that the former passes NULL to
ftrace_stack_trace() instead of regs. Have the former be a static inline of
the latter which passes NULL for regs.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The functions trace_buffer_unlock_commit() and the _regs() version are only
used within the kernel/trace directory. Move them to the local header and
remove the export as well.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The function filter_check_discard() is small and only called by one user,
its code can be folded into that one caller and make the code a bit less
comlplex.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Nothing outside of the tracing directory calls filter_check_discard() or
check_filter_check_discard(). They should not be called by modules. Move
their prototypes into the local tracing header and remove their
EXPORT_SYMBOL() macros.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The functions event_trigger_unlock_commit() and
event_trigger_unlock_commit_regs() are no longer used outside the tracing
system. Move them out of the generic headers and into the local one.
Along with __event_trigger_test_discard() that is only used by them.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In the ppc64 big endian ABI, function symbols point to function
descriptors. The symbols which point to the function entry points
have a dot in front of the function name. Consequently, when the
ftrace filter mechanism searches for the symbol corresponding to
an entry point address, it gets the dot symbol.
As a result, ftrace filter users have to be aware of this ABI detail on
ppc64 and prepend a dot to the function name when setting the filter.
The perf probe command insulates the user from this by ignoring the dot
in front of the symbol name when matching function names to symbols,
but the sysfs interface does not. This patch makes the ftrace filter
mechanism do the same when searching symbols.
Fixes the following failure in ftracetest's kprobe_ftrace.tc:
.../kprobe_ftrace.tc: line 9: echo: write error: Invalid argument
That failure is on this line of kprobe_ftrace.tc:
echo _do_fork > set_ftrace_filter
This is because there's no _do_fork entry in the functions list:
# cat available_filter_functions | grep _do_fork
._do_fork
This change introduces no regressions on the perf and ftracetest
testsuite results.
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With the following code snippet:
...
char buf[64];
...
if (copy_from_user(&buf, ubuf, cnt))
...
Even though the value of "&buf" equals "buf", but there is no need
to get the address of the "buf" again. Use "buf" instead of "&buf".
Link: http://lkml.kernel.org/r/20160418152329.18b72bea@debian
Signed-off-by: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If tracing_map_elt_alloc() fails, it will return ERR_PTR() instead of
NULL, so change the check to IS_ERROR(). We also need to set the
failed entry in the map->elts array to NULL instead of ERR_PTR() so
tracing_map_free_elts() doesn't try freeing an ERR_PTR().
tracing_map_free_elts() should also zero out what it frees so a
reentrant call won't find previously freed elements.
Link: http://lkml.kernel.org/r/f29d03b00bce3aac8cf151a8a30e6c83e5fee66d.1461610073.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Smatch flagged create_hist_field() as possibly being able to
dereference a NULL pointer, although the current code exits in all
cases where the event field could be NULL, so it's not actually a
problem.
Still, to prevent future changes to the code from overlooking new
cases, make the NULL pointer check explicit and warn once in that
case.
Link: http://lkml.kernel.org/r/cfbc003f534a3e441b4313272fd412310aba6336.1461610073.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As the event-fork option requires doing work when enabled and disabled, it
can not be passed down to created instances. The instance must clear this
flag when it is created, and must clear it when its removed.
As more options may be created with this need, a macro ZEROED_TRACE_FLAGS is
created that holds the flags that must not be inherited by the top level
instance, and must be cleared on removal of instances.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch adds a new helper for cls/act programs that can push events
to user space applications. For networking, this can be f.e. for sampling,
debugging, logging purposes or pushing of arbitrary wake-up events. The
idea is similar to a43eec3042 ("bpf: introduce bpf_perf_event_output()
helper") and 39111695b1 ("samples: bpf: add bpf_perf_event_output example").
The eBPF program utilizes a perf event array map that user space populates
with fds from perf_event_open(), the eBPF program calls into the helper
f.e. as skb_event_output(skb, &my_map, BPF_F_CURRENT_CPU, raw, sizeof(raw))
so that the raw data is pushed into the fd f.e. at the map index of the
current CPU.
User space can poll/mmap/etc on this and has a data channel for receiving
events that can be post-processed. The nice thing is that since the eBPF
program and user space application making use of it are tightly coupled,
they can define their own arbitrary raw data format and what/when they
want to push.
While f.e. packet headers could be one part of the meta data that is being
pushed, this is not a substitute for things like packet sockets as whole
packet is not being pushed and push is only done in a single direction.
Intention is more of a generically usable, efficient event pipe to applications.
Workflow is that tc can pin the map and applications can attach themselves
e.g. after cls/act setup to one or multiple map slots, demuxing is done by
the eBPF program.
Adding this facility is with minimal effort, it reuses the helper
introduced in a43eec3042 ("bpf: introduce bpf_perf_event_output() helper")
and we get its functionality for free by overloading its BPF_FUNC_ identifier
for cls/act programs, ctx is currently unused, but will be made use of in
future. Example will be added to iproute2's BPF example files.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a BPF_F_CURRENT_CPU flag to optimize the use-case where user space has
per-CPU ring buffers and the eBPF program pushes the data into the current
CPU's ring buffer which saves us an extra helper function call in eBPF.
Also, make sure to properly reserve the remaining flags which are not used.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fengguang Wu's bot found two comparisons of unsigned integers to zero. These
were real bugs, as it would miss error conditions returned to zero.
trace_events_hist.c:426:6-9: WARNING: Unsigned expression compared with zero: idx < 0
trace_events_hist.c:568:5-14: WARNING: Unsigned expression compared with zero: n_entries < 0
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to define 'named' hist triggers. All triggers created
with the same 'name=xxx' option will update the same shared histogram
data.
This expands the hist trigger syntax from this:
# echo hist:keys=xxx ... [ if filter] > event/trigger
to this:
# echo hist:name=xxx:keys=xxx ... [ if filter] > event/trigger
Named histograms must use a 'compatible' set of keys and values, which
means each event added to a set of named triggers must have the same
names and types.
Reading the 'hist' file of any of the participating events will
produce the same output as any other participating event, which is to
be expected since they share the same data.
Link: http://lkml.kernel.org/r/1dbc84ee3322a75daaf5b3ef1d0cc0a2fb682fc7.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Named triggers are sets of triggers that share a common set of trigger
data. An example of functionality that could benefit from this type
of capability would be a set of inlined probes that would each
contribute event counts, for example, to a shared counter data
structure.
The first named trigger registered with a given name owns the common
trigger data that the others subsequently registered with the same
name will reference. The functions defined here allow users to add,
delete, and find named triggers.
It also adds functions to pause and unpause named triggers; since
named triggers act upon common data, they should also be paused and
unpaused as a group.
Link: http://lkml.kernel.org/r/c09ff648360f65b10a3e321eddafe18060b4a04f.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to define any number of hist triggers per trace event.
Any number of hist triggers may be added for a given event, which may
differ by key, value, or filter.
Reading the event's 'hist' file will display the output of all the
hist triggers defined on an event concatenated in the order they were
defined.
Link: http://lkml.kernel.org/r/48a0c8dd34c344571de880fb35e211c6d9a28961.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Similar to enable_event/disable_event triggers, these triggers enable
and disable the aggregation of events into maps rather than enabling
and disabling their writing into the trace buffer.
They can be used to automatically start and stop hist triggers based
on a matching filter condition.
If there's a paused hist trigger on system:event, the following would
start it when the filter condition was hit:
# echo enable_hist:system:event [ if filter] > event/trigger
And the following would disable a running system:event hist trigger:
# echo disable_hist:system:event [ if filter] > event/trigger
See Documentation/trace/events.txt for real examples.
Link: http://lkml.kernel.org/r/f812f086e52c8b7c8ad5443487375e03c96a601f.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If we assume the maximum size for a string field, we don't have to
worry about its position. Since we only allow two keys in a compound
key and having more than one string key in a given compound key
doesn't make much sense anyway, trading a bit of extra space instead
of introducing an arbitrary restriction makes more sense.
We also need to use the event field size for static strings when
copying the contents, otherwise we get random garbage in the key.
Also, cast string return values to avoid warnings on 32-bit compiles.
Finally, rearrange the code without changing any functionality by
moving the compound key updating code into a separate function.
Link: http://lkml.kernel.org/r/8976e1ab04b66bc2700ad1ed0768a2de85ac1983.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The string in a trace event is usually recorded as dynamic array which
is variable length. But current hist code only support fixed length
array so it cannot support most strings.
This patch fixes it by checking filter_type of the field and get
proper pointer with it. With this, it can get a histogram of exec()
based on filenames like below:
# cd /sys/kernel/tracing/events/sched/sched_process_exec
# cat 'hist:key=filename' > trigger
# ps
PID TTY TIME CMD
1 ? 00:00:00 init
29 ? 00:00:00 sh
38 ? 00:00:00 ps
# ls
enable filter format hist id trigger
# cat hist
# trigger info: hist:keys=filename:vals=hitcount:sort=hitcount:size=2048 [active]
{ filename: /usr/bin/ps } hitcount: 1
{ filename: /usr/bin/ls } hitcount: 1
{ filename: /usr/bin/cat } hitcount: 1
Totals:
Hits: 3
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/610180d6df0cfdf11ee205452f3b241dea657233.1457029949.git.tom.zanussi@linux.intel.com
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ Added (unsigned long) typecast to fix compile warning ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It's often useful to be able to use a stacktrace as a hash key, for
keeping a count of the number of times a particular call path resulted
in a trace event, for instance. Add a special key named 'stacktrace'
which can be used as key in a 'keys=' param for this purpose:
# echo hist:keys=stacktrace ... \
[ if filter] > event/trigger
Link: http://lkml.kernel.org/r/87515e90b3785232a874a12156174635a348edb1.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to have syscall id fields displayed as syscall names in
the output by appending '.syscall' to field names:
# echo hist:keys=aaa.syscall ... \
[ if filter] > event/trigger
Link: http://lkml.kernel.org/r/2bab1e59933d76a14b545bd2e02f80b8b08ac4d3.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to have common_pid field values displayed as program names
in the output by appending '.execname' to a common_pid field name:
# echo hist:keys=common_pid.execname ... \
[ if filter] > event/trigger
Link: http://lkml.kernel.org/r/e172e81f10f5b8d1f08450e3763c850f39fbf698.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to have address fields displayed as symbols in the output
by appending '.sym' or 'sym-offset' to field names:
# echo hist:keys=aaa.sym,bbb.sym-offset ... \
[ if filter] > event/trigger
Link: http://lkml.kernel.org/r/87d4935821491c0275513f0fbfb9bab8d3d3f079.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to have numeric fields displayed as hex values in the
output by appending '.hex' to field names:
# echo hist:keys=aaa,bbb.hex:vals=ccc.hex ... \
[ if filter] > event/trigger
Link: http://lkml.kernel.org/r/67bd431edda2af5798d7694818f7e8d71b6b3463.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to append 'clear' to an existing trigger in order to have
the hash table cleared.
This expands the hist trigger syntax from this:
# echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont \
[ if filter] >> event/trigger
to this:
# echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont/clear \
[ if filter] >> event/trigger
Link: http://lkml.kernel.org/r/ae15dd0d9b2f7af07a37c1ff682063e2dbcdf160.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to append 'pause' or 'continue' to an existing trigger in
order to have it paused or to have a paused trace continue.
This expands the hist trigger syntax from this:
# echo hist:keys=xxx:vals=yyy:sort=zzz.descending \
[ if filter] >> event/trigger
to this:
# echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause or cont \
[ if filter] >> event/trigger
Link: http://lkml.kernel.org/r/b672a92c14702cb924cdf6fc27ea1809bed04907.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to specify keys and/or values to sort on. With this
addition, keys and values specified using the 'keys=' and 'vals='
keywords can be used to sort the hist trigger output via a new 'sort='
keyword. If multiple sort keys are specified, the output will be
sorted using the second key as a secondary sort key, etc. The default
sort order is ascending; if the user wants a different sort order,
'.descending' can be appended to the specific sort key. Before this
addition, output was always sorted by 'hitcount' in ascending order.
This expands the hist trigger syntax from this:
# echo hist:keys=xxx:vals=yyy \
[ if filter] > event/trigger
to this:
# echo hist:keys=xxx:vals=yyy:sort=zzz.descending \
[ if filter] > event/trigger
Link: http://lkml.kernel.org/r/b30a41db66ba486979c4f987aff5fab500ea53b3.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to specify multiple trace event fields to use in keys by
allowing multiple fields in the 'keys=' keyword. With this addition,
any unique combination of any of the fields named in the 'keys'
keyword will result in a new entry being added to the hash table.
Link: http://lkml.kernel.org/r/0cfa24e6ac3b0dcece7737d94aa1f322ae3afc4b.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow users to specify trace event fields to use in aggregated sums
via a new 'vals=' keyword. Before this addition, the only aggregated
sum supported was the implied value 'hitcount'. With this addition,
'hitcount' is also supported as an explicit value field, as is any
numeric trace event field.
This expands the hist trigger syntax from this:
# echo hist:keys=xxx [ if filter] > event/trigger
to this:
# echo hist:keys=xxx:vals=yyy [ if filter] > event/trigger
Link: http://lkml.kernel.org/r/2a5d1adb5ba6c65d7bb2148e379f2fed47f29a68.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make it clear exactly how many keys and values are supported through
better defines, and add 1 to the vals count, since normally clients
want support for at least a hitcount and two other values.
Also, note the error return value for tracing_map_add_key/val_field()
in the comments.
Link: http://lkml.kernel.org/r/6696fa02ebc716aa344c27a571a2afaa25e5b4d4.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The config option for TRACING_MAP has "default n", which is not needed
because the default of configs is 'n'.
Also, since the TRACING_MAP has no config prompt, there's no reason to
include "If in doubt, say N" in the help text.
Fixed a typo in the comments of tracing_map.h.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add tracing_map, a special-purpose lock-free map for tracing.
tracing_map is designed to aggregate or 'sum' one or more values
associated with a specific object of type tracing_map_elt, which
is associated by the map to a given key.
It provides various hooks allowing per-tracer customization and is
separated out into a separate file in order to allow it to be shared
between multiple tracers, but isn't meant to be generally used outside
of that context.
The tracing_map implementation was inspired by lock-free map
algorithms originated by Dr. Cliff Click:
http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtablehttp://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf
Link: http://lkml.kernel.org/r/b43d68d1add33582a396f553c8ef705a33a6a748.1449767187.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add the infrastructure needed to have the PIDs in set_event_pid to
automatically add PIDs of the children of the tasks that have their PIDs in
set_event_pid. This will also remove PIDs from set_event_pid when a task
exits
This is implemented by adding hooks into the fork and exit tracepoints. On
fork, the PIDs are added to the list, and on exit, they are removed.
Add a new option called event_fork that when set, PIDs in set_event_pid will
automatically get their children PIDs added when they fork, as well as any
task that exits will have its PID removed from set_event_pid.
This works for instances as well.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In order to add the ability to let tasks that are filtered by the events
have their children also be traced on fork (and then not traced on exit),
convert the array into a pid bitmask. Most of the time the number of pids is
only 32768 pids or a 4k bitmask, which is the same size as the default list
currently is, and that list could grow if more pids are listed.
This also greatly simplifies the code.
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "check_ignore_pid" is confusing in trying to figure out if the pid
should be ignored or not. Rename it to "ignore_this_task" which is pretty
straight forward, as a task (not a pid) is passed in, and should if true
should be ignored.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Two new functions in bpf contain a cast from a 'u64' to a
pointer. This works on 64-bit architectures but causes a warning
on all 32-bit architectures:
kernel/trace/bpf_trace.c: In function 'bpf_perf_event_output_tp':
kernel/trace/bpf_trace.c:350:13: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
u64 ctx = *(long *)r1;
This changes the cast to first convert the u64 argument into a uintptr_t,
which is guaranteed to be the same size as a pointer.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 9940d67c93 ("bpf: support bpf_get_stackid() and bpf_perf_event_output() in tracepoint programs")
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch converts all helpers that can use ARG_PTR_TO_RAW_STACK as argument
type. For tc programs this is bpf_skb_load_bytes(), bpf_skb_get_tunnel_key(),
bpf_skb_get_tunnel_opt(). For tracing, this optimizes bpf_get_current_comm()
and bpf_probe_read(). The check in bpf_skb_load_bytes() for MAX_BPF_STACK can
also be removed since the verifier already makes sure we stay within bounds
on stack buffers.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to support live patching on powerpc we would like to call
ftrace_location_range(), so make it global.
Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
during bpf program loading remember the last byte of ctx access
and at the time of attaching the program to tracepoint check that
the program doesn't access bytes beyond defined in tracepoint fields
This also disallows access to __dynamic_array fields, but can be
relaxed in the future.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
needs two wrapper functions to fetch 'struct pt_regs *' to convert
tracepoint bpf context into kprobe bpf context to reuse existing
helper functions
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
register tracepoint bpf program type and let it call the same set
of helper functions as BPF_PROG_TYPE_KPROBE
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
split allows to move expensive update of 'struct trace_entry' to later phase.
Repurpose unused 1st argument of perf_tp_event() to indicate event type.
While splitting use temp variable 'rctx' instead of '*rctx' to avoid
unnecessary loads done by the compiler due to -fno-strict-aliasing
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
avoid memset in perf_fetch_caller_regs, since it's the critical path of all tracepoints.
It's called from perf_sw_event_sched, perf_event_task_sched_in and all of perf_trace_##call
with this_cpu_ptr(&__perf_regs[..]) which are zero initialized by perpcu init logic and
subsequent call to perf_arch_fetch_caller_regs initializes the same fields on all archs,
so we can safely drop memset from all of the above cases and move it into
perf_ftrace_function_call that calls it with stack allocated pt_regs.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new cpufreq scaling governor, called "schedutil", that uses
scheduler-provided CPU utilization information as input for making
its decisions.
Doing that is possible after commit 34e2c555f3 (cpufreq: Add
mechanism for registering utilization update callbacks) that
introduced cpufreq_update_util() called by the scheduler on
utilization changes (from CFS) and RT/DL task status updates.
In particular, CPU frequency scaling decisions may be based on
the the utilization data passed to cpufreq_update_util() by CFS.
The new governor is relatively simple.
The frequency selection formula used by it depends on whether or not
the utilization is frequency-invariant. In the frequency-invariant
case the new CPU frequency is given by
next_freq = 1.25 * max_freq * util / max
where util and max are the last two arguments of cpufreq_update_util().
In turn, if util is not frequency-invariant, the maximum frequency in
the above formula is replaced with the current frequency of the CPU:
next_freq = 1.25 * curr_freq * util / max
The coefficient 1.25 corresponds to the frequency tipping point at
(util / max) = 0.8.
All of the computations are carried out in the utilization update
handlers provided by the new governor. One of those handlers is
used for cpufreq policies shared between multiple CPUs and the other
one is for policies with one CPU only (and therefore it doesn't need
to use any extra synchronization means).
The governor supports fast frequency switching if that is supported
by the cpufreq driver in use and possible for the given policy.
In the fast switching case, all operations of the governor take
place in its utilization update handlers. If fast switching cannot
be used, the frequency switch operations are carried out with the
help of a work item which only calls __cpufreq_driver_target()
(under a mutex) to trigger a frequency update (to a value already
computed beforehand in one of the utilization update handlers).
Currently, the governor treats all of the RT and DL tasks as
"unknown utilization" and sets the frequency to the allowed
maximum when updated from the RT or DL sched classes. That
heavy-handed approach should be replaced with something more
subtle and specifically targeted at RT and DL tasks.
The governor shares some tunables management code with the
"ondemand" and "conservative" governors and uses some common
definitions from cpufreq_governor.h, but apart from that it
is stand-alone.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Currently we check sample type for ftrace:function events
even if it's not created as a sampling event. That prevents
creating ftrace_function event in counting mode.
Make sure we check sample types only for sampling events.
Before:
$ sudo perf stat -e ftrace:function ls
...
Performance counter stats for 'ls':
<not supported> ftrace:function
0.001983662 seconds time elapsed
After:
$ sudo perf stat -e ftrace:function ls
...
Performance counter stats for 'ls':
44,498 ftrace:function
0.037534722 seconds time elapsed
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1458138873-1553-2-git-send-email-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.
Move the definition of __irq_entry to <linux/interrupt.h> so that the
users don't need to pull in <linux/ftrace.h>. Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some visible changes:
A new flag was added to distinguish traces done in NMI context.
Preempt tracer now shows functions where preemption is disabled but
interrupts are still enabled.
Other notes:
Updates were done to function tracing to allow better performance
with perf.
Infrastructure code has been added to allow for a new histogram
feature for recording live trace event histograms that can be
configured by simple user commands. The feature itself was just
finished, but needs a round in linux-next before being pulled.
This only includes some infrastructure changes that will be needed.
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Merge tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"Nothing major this round. Mostly small clean ups and fixes.
Some visible changes:
- A new flag was added to distinguish traces done in NMI context.
- Preempt tracer now shows functions where preemption is disabled but
interrupts are still enabled.
Other notes:
- Updates were done to function tracing to allow better performance
with perf.
- Infrastructure code has been added to allow for a new histogram
feature for recording live trace event histograms that can be
configured by simple user commands. The feature itself was just
finished, but needs a round in linux-next before being pulled.
This only includes some infrastructure changes that will be needed"
* tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (22 commits)
tracing: Record and show NMI state
tracing: Fix trace_printk() to print when not using bprintk()
tracing: Remove redundant reset per-CPU buff in irqsoff tracer
x86: ftrace: Fix the misleading comment for arch/x86/kernel/ftrace.c
tracing: Fix crash from reading trace_pipe with sendfile
tracing: Have preempt(irqs)off trace preempt disabled functions
tracing: Fix return while holding a lock in register_tracer()
ftrace: Use kasprintf() in ftrace_profile_tracefs()
ftrace: Update dynamic ftrace calls only if necessary
ftrace: Make ftrace_hash_rec_enable return update bool
tracing: Fix typoes in code comment and printk in trace_nop.c
tracing, writeback: Replace cgroup path to cgroup ino
tracing: Use flags instead of bool in trigger structure
tracing: Add an unreg_all() callback to trigger commands
tracing: Add needs_rec flag to event triggers
tracing: Add a per-event-trigger 'paused' field
tracing: Add get_syscall_name()
tracing: Add event record param to trigger_ops.func()
tracing: Make event trigger functions available
tracing: Make ftrace_event_field checking functions available
...
Use the more common logging method with the eventual goal of removing
pr_warning altogether.
Miscellanea:
- Realign arguments
- Coalesce formats
- Add missing space between a few coalesced formats
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [kernel/power/suspend.c]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The latency tracer format has a nice column to indicate IRQ state, but
this is not able to tell us about NMI state.
When tracing perf interrupt handlers (which often run in NMI context)
it is very useful to see how the events nest.
Link: http://lkml.kernel.org/r/20160318153022.105068893@infradead.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The trace_printk() code will allocate extra buffers if the compile detects
that a trace_printk() is used. To do this, the format of the trace_printk()
is saved to the __trace_printk_fmt section, and if that section is bigger
than zero, the buffers are allocated (along with a message that this has
happened).
If trace_printk() uses a format that is not a constant, and thus something
not guaranteed to be around when the print happens, the compiler optimizes
the fmt out, as it is not used, and the __trace_printk_fmt section is not
filled. This means the kernel will not allocate the special buffers needed
for the trace_printk() and the trace_printk() will not write anything to the
tracing buffer.
Adding a "__used" to the variable in the __trace_printk_fmt section will
keep it around, even though it is set to NULL. This will keep the string
from being printed in the debugfs/tracing/printk_formats section as it is
not needed.
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 07d777fe8c "tracing: Add percpu buffers for trace_printk()"
Cc: stable@vger.kernel.org # v3.5+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull networking updates from David Miller:
"Highlights:
1) Support more Realtek wireless chips, from Jes Sorenson.
2) New BPF types for per-cpu hash and arrap maps, from Alexei
Starovoitov.
3) Make several TCP sysctls per-namespace, from Nikolay Borisov.
4) Allow the use of SO_REUSEPORT in order to do per-thread processing
of incoming TCP/UDP connections. The muxing can be done using a
BPF program which hashes the incoming packet. From Craig Gallek.
5) Add a multiplexer for TCP streams, to provide a messaged based
interface. BPF programs can be used to determine the message
boundaries. From Tom Herbert.
6) Add 802.1AE MACSEC support, from Sabrina Dubroca.
7) Avoid factorial complexity when taking down an inetdev interface
with lots of configured addresses. We were doing things like
traversing the entire address less for each address removed, and
flushing the entire netfilter conntrack table for every address as
well.
8) Add and use SKB bulk free infrastructure, from Jesper Brouer.
9) Allow offloading u32 classifiers to hardware, and implement for
ixgbe, from John Fastabend.
10) Allow configuring IRQ coalescing parameters on a per-queue basis,
from Kan Liang.
11) Extend ethtool so that larger link mode masks can be supported.
From David Decotigny.
12) Introduce devlink, which can be used to configure port link types
(ethernet vs Infiniband, etc.), port splitting, and switch device
level attributes as a whole. From Jiri Pirko.
13) Hardware offload support for flower classifiers, from Amir Vadai.
14) Add "Local Checksum Offload". Basically, for a tunneled packet
the checksum of the outer header is 'constant' (because with the
checksum field filled into the inner protocol header, the payload
of the outer frame checksums to 'zero'), and we can take advantage
of that in various ways. From Edward Cree"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits)
bonding: fix bond_get_stats()
net: bcmgenet: fix dma api length mismatch
net/mlx4_core: Fix backward compatibility on VFs
phy: mdio-thunder: Fix some Kconfig typos
lan78xx: add ndo_get_stats64
lan78xx: handle statistics counter rollover
RDS: TCP: Remove unused constant
RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket
net: smc911x: convert pxa dma to dmaengine
team: remove duplicate set of flag IFF_MULTICAST
bonding: remove duplicate set of flag IFF_MULTICAST
net: fix a comment typo
ethernet: micrel: fix some error codes
ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it
bpf, dst: add and use dst_tclassid helper
bpf: make skb->tc_classid also readable
net: mvneta: bm: clarify dependencies
cls_bpf: reset class and reuse major in da
ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c
ldmvsw: Add ldmvsw.c driver code
...
There is no reason to do it twice: from commit b6f11df26f
("trace: Call tracing_reset_online_cpus before tracer->init()")
resetting of per-CPU buffers done before tracer->init() call.
tracer->init() calls {irqs,preempt,preemptirqs}off_tracer_init() and it
calls __irqsoff_tracer_init(), which resets per-CPU ringbuffer second
time.
It's slowpath, but anyway.
Link: http://lkml.kernel.org/r/1445278226-16187-1-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If tracing contains data and the trace_pipe file is read with sendfile(),
then it can trigger a NULL pointer dereference and various BUG_ON within the
VM code.
There's a patch to fix this in the splice_to_pipe() code, but it's also a
good idea to not let that happen from trace_pipe either.
Link: http://lkml.kernel.org/r/1457641146-9068-1-git-send-email-rabin@rab.in
Cc: stable@vger.kernel.org # 2.6.30+
Reported-by: Rabin Vincent <rabin.vincent@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Joel Fernandes reported that the function tracing of preempt disabled
sections was not being reported when running either the preemptirqsoff or
preemptoff tracers. This was due to the fact that the function tracer
callback for those tracers checked if irqs were disabled before tracing. But
this fails when we want to trace preempt off locations as well.
Joel explained that he wanted to see funcitons where interrupts are enabled
but preemption was disabled. The expected output he wanted:
<...>-2265 1d.h1 3419us : preempt_count_sub <-irq_exit
<...>-2265 1d..1 3419us : __do_softirq <-irq_exit
<...>-2265 1d..1 3419us : msecs_to_jiffies <-__do_softirq
<...>-2265 1d..1 3420us : irqtime_account_irq <-__do_softirq
<...>-2265 1d..1 3420us : __local_bh_disable_ip <-__do_softirq
<...>-2265 1..s1 3421us : run_timer_softirq <-__do_softirq
<...>-2265 1..s1 3421us : hrtimer_run_pending <-run_timer_softirq
<...>-2265 1..s1 3421us : _raw_spin_lock_irq <-run_timer_softirq
<...>-2265 1d.s1 3422us : preempt_count_add <-_raw_spin_lock_irq
<...>-2265 1d.s2 3422us : _raw_spin_unlock_irq <-run_timer_softirq
<...>-2265 1..s2 3422us : preempt_count_sub <-_raw_spin_unlock_irq
<...>-2265 1..s1 3423us : rcu_bh_qs <-__do_softirq
<...>-2265 1d.s1 3423us : irqtime_account_irq <-__do_softirq
<...>-2265 1d.s1 3423us : __local_bh_enable <-__do_softirq
There's a comment saying that the irq disabled check is because there's a
possible race that tracing_cpu may be set when the function is executed. But
I don't remember that race. For now, I added a check for preemption being
enabled too to not record the function, as there would be no race if that
was the case. I need to re-investigate this, as I'm now thinking that the
tracing_cpu will always be correct. But no harm in keeping the check for
now, except for the slight performance hit.
Link: http://lkml.kernel.org/r/1457770386-88717-1-git-send-email-agnel.joel@gmail.com
Fixes: 5e6d2b9cfa "tracing: Use one prologue for the preempt irqs off tracer function tracers"
Cc: stable@vget.kernel.org # 2.6.37+
Reported-by: Joel Fernandes <agnel.joel@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
commit d39cdd2036 ("tracing: Make tracer_flags use the right set_flag
callback") introduces a potential mutex deadlock issue, as it forgets to
free the mutex when allocaing the tracer_flags gets fail.
The issue was found by Dan Carpenter through Smatch static code check tool.
Link: http://lkml.kernel.org/r/1457958941-30265-1-git-send-email-chuhu@redhat.com
Fixes: d39cdd2036 ("tracing: Make tracer_flags use the right set_flag callback")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently dynamic ftrace calls are updated any time
the ftrace_ops is un/registered. If we do this update
only when it's needed, we save lot of time for perf
system wide ftrace function sampling/counting.
The reason is that for system wide sampling/counting,
perf creates event for each cpu in the system.
Each event then registers separate copy of ftrace_ops,
which ends up in FTRACE_UPDATE_CALLS updates. On servers
with many cpus that means serious stall (240 cpus server):
Counting:
# time ./perf stat -e ftrace:function -a sleep 1
Performance counter stats for 'system wide':
370,663 ftrace:function
1.401427505 seconds time elapsed
real 3m51.743s
user 0m0.023s
sys 3m48.569s
Sampling:
# time ./perf record -e ftrace:function -a sleep 1
[ perf record: Woken up 0 times to write data ]
Warning:
Processed 141200 events and lost 5 chunks!
[ perf record: Captured and wrote 10.703 MB perf.data (135950 samples) ]
real 2m31.429s
user 0m0.213s
sys 2m29.494s
There's no reason to do the FTRACE_UPDATE_CALLS update
for each event in perf case, because all the ftrace_ops
always share the same filter, so the updated calls are
always the same.
It's required that only first ftrace_ops registration
does the FTRACE_UPDATE_CALLS update (also sometimes
the second if the first one used the trampoline), but
the rest can be only cheaply linked into the ftrace_ops
list.
Counting:
# time ./perf stat -e ftrace:function -a sleep 1
Performance counter stats for 'system wide':
398,571 ftrace:function
1.377503733 seconds time elapsed
real 0m2.787s
user 0m0.005s
sys 0m1.883s
Sampling:
# time ./perf record -e ftrace:function -a sleep 1
[ perf record: Woken up 0 times to write data ]
Warning:
Processed 261730 events and lost 9 chunks!
[ perf record: Captured and wrote 19.907 MB perf.data (256293 samples) ]
real 1m31.948s
user 0m0.309s
sys 1m32.051s
Link: http://lkml.kernel.org/r/1458138873-1553-6-git-send-email-jolsa@kernel.org
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Change __ftrace_hash_rec_update to return true in case
we need to update dynamic ftrace call records. It return
false in case no update is needed.
Link: http://lkml.kernel.org/r/1458138873-1553-5-git-send-email-jolsa@kernel.org
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
- Redesign of cpufreq governors and the intel_pstate driver to
make them use callbacks invoked by the scheduler to trigger CPU
frequency evaluation instead of using per-CPU deferrable timers
for that purpose (Rafael Wysocki).
- Reorganization and cleanup of cpufreq governor code to make it
more straightforward and fix some concurrency problems in it
(Rafael Wysocki, Viresh Kumar).
- Cleanup and improvements of locking in the cpufreq core (Viresh
Kumar).
- Assorted cleanups in the cpufreq core (Rafael Wysocki, Viresh
Kumar, Eric Biggers).
- intel_pstate driver updates including fixes, optimizations and a
modification to make it enable enable hardware-coordinated P-state
selection (HWP) by default if supported by the processor (Philippe
Longepe, Srinivas Pandruvada, Rafael Wysocki, Viresh Kumar, Felipe
Franciosi).
- Operating Performance Points (OPP) framework updates to improve
its handling of voltage regulators and device clocks and updates
of the cpufreq-dt driver on top of that (Viresh Kumar, Jon Hunter).
- Updates of the powernv cpufreq driver to fix initialization
and cleanup problems in it and correct its worker thread handling
with respect to CPU offline, new powernv_throttle tracepoint
(Shilpasri Bhat).
- ACPI cpufreq driver optimization and cleanup (Rafael Wysocki).
- ACPICA updates including one fix for a regression introduced
by previos changes in the ACPICA code (Bob Moore, Lv Zheng,
David Box, Colin Ian King).
- Support for installing ACPI tables from initrd (Lv Zheng).
- Optimizations of the ACPI CPPC code (Prashanth Prakash, Ashwin
Chaugule).
- Support for _HID(ACPI0010) devices (ACPI processor containers)
and ACPI processor driver cleanups (Sudeep Holla).
- Support for ACPI-based enumeration of the AMBA bus (Graeme Gregory,
Aleksey Makarov).
- Modification of the ACPI PCI IRQ management code to make it treat
255 in the Interrupt Line register as "not connected" on x86 (as
per the specification) and avoid attempts to use that value as
a valid interrupt vector (Chen Fan).
- ACPI APEI fixes related to resource leaks (Josh Hunt).
- Removal of modularity from a few ACPI drivers (BGRT, GHES,
intel_pmic_crc) that cannot be built as modules in practice (Paul
Gortmaker).
- PNP framework update to make it treat ACPI_RESOURCE_TYPE_SERIAL_BUS
as a valid resource type (Harb Abdulhamid).
- New device ID (future AMD I2C controller) in the ACPI driver for
AMD SoCs (APD) and in the designware I2C driver (Xiangliang Yu).
- Assorted ACPI cleanups (Colin Ian King, Kaiyen Chang, Oleg Drokin).
- cpuidle menu governor optimization to avoid a square root
computation in it (Rasmus Villemoes).
- Fix for potential use-after-free in the generic device properties
framework (Heikki Krogerus).
- Updates of the generic power domains (genpd) framework including
support for multiple power states of a domain, fixes and debugfs
output improvements (Axel Haslam, Jon Hunter, Laurent Pinchart,
Geert Uytterhoeven).
- Intel RAPL power capping driver updates to reduce IPI overhead in
it (Jacob Pan).
- System suspend/hibernation code cleanups (Eric Biggers, Saurabh
Sengar).
- Year 2038 fix for the process freezer (Abhilash Jindal).
- turbostat utility updates including new features (decoding of more
registers and CPUID fields, sub-second intervals support, GFX MHz
and RC6 printout, --out command line option), fixes (syscall jitter
detection and workaround, reductioin of the number of syscalls made,
fixes related to Xeon x200 processors, compiler warning fixes) and
cleanups (Len Brown, Hubert Chrzaniuk, Chen Yu).
/
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Merge tag 'pm+acpi-4.6-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI updates from Rafael Wysocki:
"This time the majority of changes go into cpufreq and they are
significant.
First off, the way CPU frequency updates are triggered is different
now. Instead of having to set up and manage a deferrable timer for
each CPU in the system to evaluate and possibly change its frequency
periodically, cpufreq governors set up callbacks to be invoked by the
scheduler on a regular basis (basically on utilization updates). The
"old" governors, "ondemand" and "conservative", still do all of their
work in process context (although that is triggered by the scheduler
now), but intel_pstate does it all in the callback invoked by the
scheduler with no need for any additional asynchronous processing.
Of course, this eliminates the overhead related to the management of
all those timers, but also it allows the cpufreq governor code to be
simplified quite a bit. On top of that, the common code and data
structures used by the "ondemand" and "conservative" governors are
cleaned up and made more straightforward and some long-standing and
quite annoying problems are addressed. In particular, the handling of
governor sysfs attributes is modified and the related locking becomes
more fine grained which allows some concurrency problems to be avoided
(particularly deadlocks with the core cpufreq code).
In principle, the new mechanism for triggering frequency updates
allows utilization information to be passed from the scheduler to
cpufreq. Although the current code doesn't make use of it, in the
works is a new cpufreq governor that will make decisions based on the
scheduler's utilization data. That should allow the scheduler and
cpufreq to work more closely together in the long run.
In addition to the core and governor changes, cpufreq drivers are
updated too. Fixes and optimizations go into intel_pstate, the
cpufreq-dt driver is updated on top of some modification in the
Operating Performance Points (OPP) framework and there are fixes and
other updates in the powernv cpufreq driver.
Apart from the cpufreq updates there is some new ACPICA material,
including a fix for a problem introduced by previous ACPICA updates,
and some less significant changes in the ACPI code, like CPPC code
optimizations, ACPI processor driver cleanups and support for loading
ACPI tables from initrd.
Also updated are the generic power domains framework, the Intel RAPL
power capping driver and the turbostat utility and we have a bunch of
traditional assorted fixes and cleanups.
Specifics:
- Redesign of cpufreq governors and the intel_pstate driver to make
them use callbacks invoked by the scheduler to trigger CPU
frequency evaluation instead of using per-CPU deferrable timers for
that purpose (Rafael Wysocki).
- Reorganization and cleanup of cpufreq governor code to make it more
straightforward and fix some concurrency problems in it (Rafael
Wysocki, Viresh Kumar).
- Cleanup and improvements of locking in the cpufreq core (Viresh
Kumar).
- Assorted cleanups in the cpufreq core (Rafael Wysocki, Viresh
Kumar, Eric Biggers).
- intel_pstate driver updates including fixes, optimizations and a
modification to make it enable enable hardware-coordinated P-state
selection (HWP) by default if supported by the processor (Philippe
Longepe, Srinivas Pandruvada, Rafael Wysocki, Viresh Kumar, Felipe
Franciosi).
- Operating Performance Points (OPP) framework updates to improve its
handling of voltage regulators and device clocks and updates of the
cpufreq-dt driver on top of that (Viresh Kumar, Jon Hunter).
- Updates of the powernv cpufreq driver to fix initialization and
cleanup problems in it and correct its worker thread handling with
respect to CPU offline, new powernv_throttle tracepoint (Shilpasri
Bhat).
- ACPI cpufreq driver optimization and cleanup (Rafael Wysocki).
- ACPICA updates including one fix for a regression introduced by
previos changes in the ACPICA code (Bob Moore, Lv Zheng, David Box,
Colin Ian King).
- Support for installing ACPI tables from initrd (Lv Zheng).
- Optimizations of the ACPI CPPC code (Prashanth Prakash, Ashwin
Chaugule).
- Support for _HID(ACPI0010) devices (ACPI processor containers) and
ACPI processor driver cleanups (Sudeep Holla).
- Support for ACPI-based enumeration of the AMBA bus (Graeme Gregory,
Aleksey Makarov).
- Modification of the ACPI PCI IRQ management code to make it treat
255 in the Interrupt Line register as "not connected" on x86 (as
per the specification) and avoid attempts to use that value as a
valid interrupt vector (Chen Fan).
- ACPI APEI fixes related to resource leaks (Josh Hunt).
- Removal of modularity from a few ACPI drivers (BGRT, GHES,
intel_pmic_crc) that cannot be built as modules in practice (Paul
Gortmaker).
- PNP framework update to make it treat ACPI_RESOURCE_TYPE_SERIAL_BUS
as a valid resource type (Harb Abdulhamid).
- New device ID (future AMD I2C controller) in the ACPI driver for
AMD SoCs (APD) and in the designware I2C driver (Xiangliang Yu).
- Assorted ACPI cleanups (Colin Ian King, Kaiyen Chang, Oleg Drokin).
- cpuidle menu governor optimization to avoid a square root
computation in it (Rasmus Villemoes).
- Fix for potential use-after-free in the generic device properties
framework (Heikki Krogerus).
- Updates of the generic power domains (genpd) framework including
support for multiple power states of a domain, fixes and debugfs
output improvements (Axel Haslam, Jon Hunter, Laurent Pinchart,
Geert Uytterhoeven).
- Intel RAPL power capping driver updates to reduce IPI overhead in
it (Jacob Pan).
- System suspend/hibernation code cleanups (Eric Biggers, Saurabh
Sengar).
- Year 2038 fix for the process freezer (Abhilash Jindal).
- turbostat utility updates including new features (decoding of more
registers and CPUID fields, sub-second intervals support, GFX MHz
and RC6 printout, --out command line option), fixes (syscall jitter
detection and workaround, reductioin of the number of syscalls
made, fixes related to Xeon x200 processors, compiler warning
fixes) and cleanups (Len Brown, Hubert Chrzaniuk, Chen Yu)"
* tag 'pm+acpi-4.6-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (182 commits)
tools/power turbostat: bugfix: TDP MSRs print bits fixing
tools/power turbostat: correct output for MSR_NHM_SNB_PKG_CST_CFG_CTL dump
tools/power turbostat: call __cpuid() instead of __get_cpuid()
tools/power turbostat: indicate SMX and SGX support
tools/power turbostat: detect and work around syscall jitter
tools/power turbostat: show GFX%rc6
tools/power turbostat: show GFXMHz
tools/power turbostat: show IRQs per CPU
tools/power turbostat: make fewer systems calls
tools/power turbostat: fix compiler warnings
tools/power turbostat: add --out option for saving output in a file
tools/power turbostat: re-name "%Busy" field to "Busy%"
tools/power turbostat: Intel Xeon x200: fix turbo-ratio decoding
tools/power turbostat: Intel Xeon x200: fix erroneous bclk value
tools/power turbostat: allow sub-sec intervals
ACPI / APEI: ERST: Fixed leaked resources in erst_init
ACPI / APEI: Fix leaked resources
intel_pstate: Do not skip samples partially
intel_pstate: Remove freq calculation from intel_pstate_calc_busy()
intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance()
...
Pull perf updates from Ingo Molnar:
"Main kernel side changes:
- Big reorganization of the x86 perf support code. The old code grew
organically deep inside arch/x86/kernel/cpu/perf* and its naming
became somewhat messy.
The new location is under arch/x86/events/, using the following
cleaner hierarchy of source code files:
perf/x86: Move perf_event.c .................. => x86/events/core.c
perf/x86: Move perf_event_amd.c .............. => x86/events/amd/core.c
perf/x86: Move perf_event_amd_ibs.c .......... => x86/events/amd/ibs.c
perf/x86: Move perf_event_amd_iommu.[ch] ..... => x86/events/amd/iommu.[ch]
perf/x86: Move perf_event_amd_uncore.c ....... => x86/events/amd/uncore.c
perf/x86: Move perf_event_intel_bts.c ........ => x86/events/intel/bts.c
perf/x86: Move perf_event_intel.c ............ => x86/events/intel/core.c
perf/x86: Move perf_event_intel_cqm.c ........ => x86/events/intel/cqm.c
perf/x86: Move perf_event_intel_cstate.c ..... => x86/events/intel/cstate.c
perf/x86: Move perf_event_intel_ds.c ......... => x86/events/intel/ds.c
perf/x86: Move perf_event_intel_lbr.c ........ => x86/events/intel/lbr.c
perf/x86: Move perf_event_intel_pt.[ch] ...... => x86/events/intel/pt.[ch]
perf/x86: Move perf_event_intel_rapl.c ....... => x86/events/intel/rapl.c
perf/x86: Move perf_event_intel_uncore.[ch] .. => x86/events/intel/uncore.[ch]
perf/x86: Move perf_event_intel_uncore_nhmex.c => x86/events/intel/uncore_nmhex.c
perf/x86: Move perf_event_intel_uncore_snb.c => x86/events/intel/uncore_snb.c
perf/x86: Move perf_event_intel_uncore_snbep.c => x86/events/intel/uncore_snbep.c
perf/x86: Move perf_event_knc.c .............. => x86/events/intel/knc.c
perf/x86: Move perf_event_p4.c ............... => x86/events/intel/p4.c
perf/x86: Move perf_event_p6.c ............... => x86/events/intel/p6.c
perf/x86: Move perf_event_msr.c .............. => x86/events/msr.c
(Borislav Petkov)
- Update various x86 PMU constraint and hw support details (Stephane
Eranian)
- Optimize kprobes for BPF execution (Martin KaFai Lau)
- Rewrite, refactor and fix the Intel uncore PMU driver code (Thomas
Gleixner)
- Rewrite, refactor and fix the Intel RAPL PMU code (Thomas Gleixner)
- Various fixes and smaller cleanups.
There are lots of perf tooling updates as well. A few highlights:
perf report/top:
- Hierarchy histogram mode for 'perf top' and 'perf report',
showing multiple levels, one per --sort entry: (Namhyung Kim)
On a mostly idle system:
# perf top --hierarchy -s comm,dso
Then expand some levels and use 'P' to take a snapshot:
# cat perf.hist.0
- 92.32% perf
58.20% perf
22.29% libc-2.22.so
5.97% [kernel]
4.18% libelf-0.165.so
1.69% [unknown]
- 4.71% qemu-system-x86
3.10% [kernel]
1.60% qemu-system-x86_64 (deleted)
+ 2.97% swapper
#
- Add 'L' hotkey to dynamicly set the percent threshold for
histogram entries and callchains, i.e. dynamicly do what the
--percent-limit command line option to 'top' and 'report' does.
(Namhyung Kim)
perf mem:
- Allow specifying events via -e in 'perf mem record', also listing
what events can be specified via 'perf mem record -e list' (Jiri
Olsa)
perf record:
- Add 'perf record' --all-user/--all-kernel options, so that one
can tell that all the events in the command line should be
restricted to the user or kernel levels (Jiri Olsa), i.e.:
perf record -e cycles:u,instructions:u
is equivalent to:
perf record --all-user -e cycles,instructions
- Make 'perf record' collect CPU cache info in the perf.data file header:
$ perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.017 MB perf.data (7 samples) ]
$ perf report --header-only -I | tail -10 | head -8
# CPU cache info:
# L1 Data 32K [0-1]
# L1 Instruction 32K [0-1]
# L1 Data 32K [2-3]
# L1 Instruction 32K [2-3]
# L2 Unified 256K [0-1]
# L2 Unified 256K [2-3]
# L3 Unified 4096K [0-3]
Will be used in 'perf c2c' and eventually in 'perf diff' to
allow, for instance running the same workload in multiple
machines and then when using 'diff' show the hardware difference.
(Jiri Olsa)
- Improved support for Java, using the JVMTI agent library to do
jitdumps that then will be inserted in synthesized
PERF_RECORD_MMAP2 events via 'perf inject' pointed to synthesized
ELF files stored in ~/.debug and keyed with build-ids, to allow
symbol resolution and even annotation with source line info, see
the changeset comments to see how to use it (Stephane Eranian)
perf script/trace:
- Decode data_src values (e.g. perf.data files generated by 'perf
mem record') in 'perf script': (Jiri Olsa)
# perf script
perf 693 [1] 4.088652: 1 cpu/mem-loads,ldlat=30/P: ffff88007d0b0f40 68100142 L1 hit|SNP None|TLB L1 or L2 hit|LCK No <SNIP>
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- Improve support to 'data_src', 'weight' and 'addr' fields in
'perf script' (Jiri Olsa)
- Handle empty print fmts in 'perf script -s' i.e. when running
python or perl scripts (Taeung Song)
perf stat:
- 'perf stat' now shows shadow metrics (insn per cycle, etc) in
interval mode too. E.g:
# perf stat -I 1000 -e instructions,cycles sleep 1
# time counts unit events
1.000215928 519,620 instructions # 0.69 insn per cycle
1.000215928 752,003 cycles
<SNIP>
- Port 'perf kvm stat' to PowerPC (Hemant Kumar)
- Implement CSV metrics output in 'perf stat' (Andi Kleen)
perf BPF support:
- Support converting data from bpf events in 'perf data' (Wang Nan)
- Print bpf-output events in 'perf script': (Wang Nan).
# perf record -e bpf-output/no-inherit,name=evt/ -e ./test_bpf_output_3.c/map:channel.event=evt/ usleep 1000
# perf script
usleep 4882 21384.532523: evt: ffffffff810e97d1 sys_nanosleep ([kernel.kallsyms])
BPF output: 0000: 52 61 69 73 65 20 61 20 Raise a
0008: 42 50 46 20 65 76 65 6e BPF even
0010: 74 21 00 00 t!..
BPF string: "Raise a BPF event!"
#
- Add API to set values of map entries in a BPF object, be it
individual map slots or ranges (Wang Nan)
- Introduce support for the 'bpf-output' event (Wang Nan)
- Add glue to read perf events in a BPF program (Wang Nan)
- Improve support for bpf-output events in 'perf trace' (Wang Nan)
... and tons of other changes as well - see the shortlog and git log
for details!"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (342 commits)
perf stat: Add --metric-only support for -A
perf stat: Implement --metric-only mode
perf stat: Document CSV format in manpage
perf hists browser: Check sort keys before hot key actions
perf hists browser: Allow thread filtering for comm sort key
perf tools: Add sort__has_comm variable
perf tools: Recalc total periods using top-level entries in hierarchy
perf tools: Remove nr_sort_keys field
perf hists browser: Cleanup hist_browser__fprintf_hierarchy_entry()
perf tools: Remove hist_entry->fmt field
perf tools: Fix command line filters in hierarchy mode
perf tools: Add more sort entry check functions
perf tools: Fix hist_entry__filter() for hierarchy
perf jitdump: Build only on supported archs
tools lib traceevent: Add '~' operation within arg_num_eval()
perf tools: Omit unnecessary cast in perf_pmu__parse_scale
perf tools: Pass perf_hpp_list all the way through setup_sort_list
perf tools: Fix perf script python database export crash
perf jitdump: DWARF is also needed
perf bench mem: Prepare the x86-64 build for upstream memcpy_mcsafe() changes
...
* pm-cpufreq: (94 commits)
intel_pstate: Do not skip samples partially
intel_pstate: Remove freq calculation from intel_pstate_calc_busy()
intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance()
intel_pstate: Optimize calculation for max/min_perf_adj
intel_pstate: Remove extra conversions in pid calculation
cpufreq: Move scheduler-related code to the sched directory
Revert "cpufreq: postfix policy directory with the first CPU in related_cpus"
cpufreq: Reduce cpufreq_update_util() overhead a bit
cpufreq: Select IRQ_WORK if CPU_FREQ_GOV_COMMON is set
cpufreq: Remove 'policy->governor_enabled'
cpufreq: Rename __cpufreq_governor() to cpufreq_governor()
cpufreq: Relocate handle_update() to kill its declaration
cpufreq: governor: Drop unnecessary checks from show() and store()
cpufreq: governor: Fix race in dbs_update_util_handler()
cpufreq: governor: Make gov_set_update_util() static
cpufreq: governor: Narrow down the dbs_data_mutex coverage
cpufreq: governor: Make dbs_data_mutex static
cpufreq: governor: Relocate definitions of tuners structures
cpufreq: governor: Move per-CPU data to the common code
cpufreq: governor: Make governor private data per-policy
...
if kprobe is placed within update or delete hash map helpers
that hold bucket spin lock and triggered bpf program is trying to
grab the spinlock for the same bucket on the same cpu, it will
deadlock.
Fix it by extending existing recursion prevention mechanism.
Note, map_lookup and other tracing helpers don't have this problem,
since they don't hold any locks and don't modify global data.
bpf_trace_printk has its own recursive check and ok as well.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Several cases of overlapping changes, as well as one instance
(vxlan) of a bug fix in 'net' overlapping with code movement
in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
echo nop > /sys/kernel/debug/tracing/options/current_tracer
echo 1 > /sys/kernel/debug/tracing/options/test_nop_accept
echo 0 > /sys/kernel/debug/tracing/options/test_nop_accept
echo 1 > /sys/kernel/debug/tracing/options/test_nop_refuse
Before the fix, the dmesg is a bit ugly since a align issue.
[ 191.973081] nop_test_accept flag set to 1: we accept. Now cat trace_options to see the result
[ 195.156942] nop_test_refuse flag set to 1: we refuse.Now cat trace_options to see the result
After the fix, the dmesg will show aligned log for nop_test_refuse and nop_test_accept.
[ 2718.032413] nop_test_refuse flag set to 1: we refuse. Now cat trace_options to see the result
[ 2734.253360] nop_test_accept flag set to 1: we accept. Now cat trace_options to see the result
Link: http://lkml.kernel.org/r/1457444222-8654-2-git-send-email-chuhu@redhat.com
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
gcc isn't known for handling bool in structures. Instead of using bool, use
an integer mask and use bit flags instead.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a new unreg_all() callback that can be used to remove all
command-specific triggers from an event and arrange to have it called
whenever a trigger file is opened with O_TRUNC set.
Commands that don't want truncate semantics, or existing commands that
don't implement this function simply do nothing and their triggers
remain intact.
Link: http://lkml.kernel.org/r/2b7d62854d01f28c19185e1bbb8f826f385edfba.1449767187.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a new needs_rec flag for triggers that require unconditional
access to trace records in order to function.
Normally a trigger requires access to the contents of a trace record
only if it has a filter associated with it (since filters need the
contents of a record in order to make a filtering decision). Some
types of triggers, such as 'hist' triggers, require access to trace
record contents independent of the presence of filters, so add a new
flag for those triggers.
Link: http://lkml.kernel.org/r/7be8fa38f9b90fdb6c47ca0f98d20a07b9fd512b.1449767187.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a simple per-trigger 'paused' flag, allowing individual triggers
to pause. We could leave it to individual triggers that need this
functionality to do it themselves, but we also want to allow other
events to control pausing, so add it to the trigger data.
Link: http://lkml.kernel.org/r/fed37e4879684d7dcc57fe00ce0cbf170032b06d.1449767187.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Some triggers may need access to the trace event, so pass it in. Also
fix up the existing trigger funcs and their callers.
Link: http://lkml.kernel.org/r/543e31e9fc445ef61077421ab219033401c39846.1449767187.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make various event trigger utility functions available outside of
trace_events_trigger.c so that new triggers can be defined outside of
that file.
Link: http://lkml.kernel.org/r/4a40c1695dd43cac6cd475d72e13ffe30ba84bff.1449767187.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make is_string_field() and is_function_field() accessible outside of
trace_event_filters.c for other users of ftrace_event_fields.
Link: http://lkml.kernel.org/r/2d3f00d3311702e556e82eed7754bae6f017939f.1449767187.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When I was updating the ftrace_stress test of ltp. I encountered
a strange phenomemon, excute following steps:
echo nop > /sys/kernel/debug/tracing/current_tracer
echo 0 > /sys/kernel/debug/tracing/options/funcgraph-cpu
bash: echo: write error: Invalid argument
check dmesg:
[ 1024.903855] nop_test_refuse flag set to 0: we refuse.Now cat trace_options to see the result
The reason is that the trace option test will randomly setup trace
option under tracing/options no matter what the current_tracer is.
but the set_tracer_option is always using the set_flag callback
from the current_tracer. This patch adds a pointer to tracer_flags
and make it point to the tracer it belongs to. When the option is
setup, the set_flag of the right tracer will be used no matter
what the the current_tracer is.
And the old dummy_tracer_flags is used for all the tracers which
doesn't have a tracer_flags, having issue to use it to save the
pointer of a tracer. So remove it and use dynamic dummy tracer_flags
for tracers needing a dummy tracer_flags, as a result, there are no
tracers sharing tracer_flags, so remove the check code.
And save the current tracer to trace_option_dentry seems not good as
it may waste mem space when mount the debug/trace fs more than one time.
Link: http://lkml.kernel.org/r/1457444222-8654-1-git-send-email-chuhu@redhat.com
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
[ Fixed up function tracer options to work with the change ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
a tasks "comm" field. But this prevented filtering on a comm field that
is within a trace event (like sched_migrate_task).
When trying to filter on when a program migrated, this change prevented
the filtering of the sched_migrate_task.
To fix this, the event fields are examined first, and then the extra fields
like "comm" and "cpu" are examined. Also, instead of testing to assign
the comm filter function based on the field's name, the generic comm field
is given a new filter type (FILTER_COMM). When this field is used to filter
the type is checked. The same is done for the cpu filter field.
Two new special filter types are added: "COMM" and "CPU". This allows users
to still filter the tasks comm for events that have "comm" as one of their
fields, in cases that users would like to filter sched_migrate_task on the
comm of the task that called the event, and not the comm of the task that
is being migrated.
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Merge tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"A feature was added in 4.3 that allowed users to filter trace points
on a tasks "comm" field. But this prevented filtering on a comm field
that is within a trace event (like sched_migrate_task).
When trying to filter on when a program migrated, this change
prevented the filtering of the sched_migrate_task.
To fix this, the event fields are examined first, and then the extra
fields like "comm" and "cpu" are examined. Also, instead of testing
to assign the comm filter function based on the field's name, the
generic comm field is given a new filter type (FILTER_COMM). When
this field is used to filter the type is checked. The same is done
for the cpu filter field.
Two new special filter types are added: "COMM" and "CPU". This allows
users to still filter the tasks comm for events that have "comm" as
one of their fields, in cases that users would like to filter
sched_migrate_task on the comm of the task that called the event, and
not the comm of the task that is being migrated"
* tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Do not have 'comm' filter override event 'comm' field
Commit 9f61668073 "tracing: Allow triggers to filter for CPU ids and
process names" added a 'comm' filter that will filter events based on the
current tasks struct 'comm'. But this now hides the ability to filter events
that have a 'comm' field too. For example, sched_migrate_task trace event.
That has a 'comm' field of the task to be migrated.
echo 'comm == "bash"' > events/sched_migrate_task/filter
will now filter all sched_migrate_task events for tasks named "bash" that
migrates other tasks (in interrupt context), instead of seeing when "bash"
itself gets migrated.
This fix requires a couple of changes.
1) Change the look up order for filter predicates to look at the events
fields before looking at the generic filters.
2) Instead of basing the filter function off of the "comm" name, have the
generic "comm" filter have its own filter_type (FILTER_COMM). Test
against the type instead of the name to assign the filter function.
3) Add a new "COMM" filter that works just like "comm" but will filter based
on the current task, even if the trace event contains a "comm" field.
Do the same for "cpu" field, adding a FILTER_CPU and a filter "CPU".
Cc: stable@vger.kernel.org # v4.3+
Fixes: 9f61668073 "tracing: Allow triggers to filter for CPU ids and process names"
Reported-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Some tracepoint have multiple fields with the same name, "nr", the first
one is a unique syscall ID, the other is a syscall argument:
# cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
name: sys_enter_io_getevents
ID: 747
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:int nr; offset:8; size:4; signed:1;
field:aio_context_t ctx_id; offset:16; size:8; signed:0;
field:long min_nr; offset:24; size:8; signed:0;
field:long nr; offset:32; size:8; signed:0;
field:struct io_event * events; offset:40; size:8; signed:0;
field:struct timespec * timeout; offset:48; size:8; signed:0;
print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events: 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))
#
Fix it by renaming the "/format" common tracepoint field "nr" to "__syscall_nr".
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
[ Do not rename the struct member, just the '/format' field name ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160226132301.3ae065a4@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When perf added a "reg" function to the function tracing event (not a
tracepoint), it caused that event to be displayed as a tracepoint and
could cause errors in tracepoint handling. That was solved by adding a
flag to ignore ftrace non-tracepoint events. But that flag was missed
when displaying events in available_events, which should only contain
tracepoint events.
This broke a documented way to enable all events with:
cat available_events > set_event
As the function non-tracepoint event would cause that to error out.
The commit here fixes that by having the available_events file not list
events that have the ignore flag set.
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Merge tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Another small bug reported to me by Chunyu Hu.
When perf added a "reg" function to the function tracing event (not a
tracepoint), it caused that event to be displayed as a tracepoint and
could cause errors in tracepoint handling. That was solved by adding
a flag to ignore ftrace non-tracepoint events. But that flag was
missed when displaying events in available_events, which should only
contain tracepoint events.
This broke a documented way to enable all events with:
cat available_events > set_event
As the function non-tracepoint event would cause that to error out.
The commit here fixes that by having the available_events file not
list events that have the ignore flag set"
* tag 'trace-fixes-v4.5-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix showing function event in available_events
The ftrace:function event is only displayed for parsing the function tracer
data. It is not used to enable function tracing, and does not include an
"enable" file in its event directory.
Originally, this event was kept separate from other events because it did
not have a ->reg parameter. But perf added a "reg" parameter for its use
which caused issues, because it made the event available to functions where
it was not compatible for.
Commit 9b63776fa3 "tracing: Do not enable function event with enable"
added a TRACE_EVENT_FL_IGNORE_ENABLE flag that prevented the function event
from being enabled by normal trace events. But this commit missed keeping
the function event from being displayed by the "available_events" directory,
which is used to show what events can be enabled by set_event.
One documented way to enable all events is to:
cat available_events > set_event
But because the function event is displayed in the available_events, this
now causes an INVALID error:
cat: write error: Invalid argument
Reported-by: Chunyu Hu <chuhu@redhat.com>
Fixes: 9b63776fa3 "tracing: Do not enable function event with enable"
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Conflicts:
drivers/net/phy/bcm7xxx.c
drivers/net/phy/marvell.c
drivers/net/vxlan.c
All three conflicts were cases of simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
stack made by the stack tracer. As the stack tracer scans the entire
kernel stack, KASAN triggers seeing it as a "stack out of bounds" error.
As the scan is looking at the contents of the stack from parent functions.
The NOCHECK() tells KASAN that this is done on purpose, and is not some
kind of stack overflow.
The second fix is to the ftrace selftests, to retrieve the PID of executed
commands from the shell with "$!" and not by parsing "jobs".
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Merge tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Two more small fixes.
One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
stack made by the stack tracer. As the stack tracer scans the entire
kernel stack, KASAN triggers seeing it as a "stack out of bounds"
error. As the scan is looking at the contents of the stack from
parent functions. The NOCHECK() tells KASAN that this is done on
purpose, and is not some kind of stack overflow.
The second fix is to the ftrace selftests, to retrieve the PID of
executed commands from the shell with '$!' and not by parsing 'jobs'"
* tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing, kasan: Silence Kasan warning in check_stack of stack_tracer
ftracetest: Fix instance test to use proper shell command for pids
add new map type to store stack traces and corresponding helper
bpf_get_stackid(ctx, map, flags) - walk user or kernel stack and return id
@ctx: struct pt_regs*
@map: pointer to stack_trace map
@flags: bits 0-7 - numer of stack frames to skip
bit 8 - collect user stack instead of kernel
bit 9 - compare stacks by hash only
bit 10 - if two different stacks hash into the same stackid
discard old
other bits - reserved
Return: >= 0 stackid on success or negative error
stackid is a 32-bit integer handle that can be further combined with
other data (including other stackid) and used as a key into maps.
Userspace will access stackmap using standard lookup/delete syscall commands to
retrieve full stack trace for given stackid.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull livepatching fixes from Jiri Kosina:
- regression (from 4.4) fix for ordering issue, introduced by an
earlier ftrace change, that broke live patching of modules.
The fix replaces the ftrace module notifier by direct call in order
to make the ordering guaranteed and well-defined. The patch, from
Jessica Yu, has been acked both by Steven and Rusty
- error message fix from Miroslav Benes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
ftrace/module: remove ftrace module notifier
livepatch: change the error message in asm/livepatch.h header files
Remove the ftrace module notifier in favor of directly calling
ftrace_module_enable() and ftrace_release_mod() in the module loader.
Hard-coding the function calls directly in the module loader removes
dependence on the module notifier call chain and provides better
visibility and control over what gets called when, which is important
to kernel utilities such as livepatch.
This fixes a notifier ordering issue in which the ftrace module notifier
(and hence ftrace_module_enable()) for coming modules was being called
after klp_module_notify(), which caused livepatch modules to initialize
incorrectly. This patch removes dependence on the module notifier call
chain in favor of hard coding the corresponding function calls in the
module loader. This ensures that ftrace and livepatch code get called in
the correct order on patch module load and unload.
Fixes: 5156dca34a ("ftrace: Fix the race between ftrace and insmod")
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This patch adds the powernv_throttle tracepoint to trace the CPU
frequency throttling event, which is used by the powernv-cpufreq
driver in POWER8.
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Here's a simple fix to correct that issue.
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Merge tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"A cleanup to the stack tracer broke stack tracing on s390. Here's a
simple fix to correct that issue"
* tag 'trace-v4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/stacktrace: Show entire trace if passed in function not found
Pull perf fixes from Thomas Gleixner:
"This is much bigger than typical fixes, but Peter found a category of
races that spurred more fixes and more debugging enhancements. Work
started before the merge window, but got finished only now.
Aside of that this contains the usual small fixes to perf and tools.
Nothing particular exciting"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
perf: Remove/simplify lockdep annotation
perf: Synchronously clean up child events
perf: Untangle 'owner' confusion
perf: Add flags argument to perf_remove_from_context()
perf: Clean up sync_child_event()
perf: Robustify event->owner usage and SMP ordering
perf: Fix STATE_EXIT usage
perf: Update locking order
perf: Remove __free_event()
perf/bpf: Convert perf_event_array to use struct file
perf: Fix NULL deref
perf/x86: De-obfuscate code
perf/x86: Fix uninitialized value usage
perf: Fix race in perf_event_exit_task_context()
perf: Fix orphan hole
perf stat: Do not clean event's private stats
perf hists: Fix HISTC_MEM_DCACHELINE width setting
perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed
perf tests: Remove wrong semicolon in while loop in CQM test
perf: Synchronously free aux pages in case of allocation failure
...
When a max stack trace is discovered, the stack dump is saved. In order to
not record the overhead of the stack tracer, the ip of the traced function
is looked for within the dump. The trace is started from the location of
that function. But if for some reason the ip is not found, the entire stack
trace is then truncated. That's not very useful. Instead, print everything
if the ip of the traced function is not found within the trace.
This issue showed up on s390.
Link: http://lkml.kernel.org/r/20160129102241.1b3c9c04@gandalf.local.home
Fixes: 72ac426a5b ("tracing: Clean up stack tracing and fix fentry updates")
Cc: stable@vger.kernel.org # v4.3+
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The first is a cut and paste issue that changed the amount of stack
to skip when tracing a stack dump from 0 to 6, which basically made
the stack disappear for small stack traces.
The second fix is just removing an unused field in a struct that is no
longer used, and currently just wastes space.
The third is another cut-and-paste fix that had a tracepoint recording
the wrong field (it was recording the previous field a second time).
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Merge tag 'trace-v4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull minor tracing fixes from Steven Rostedt:
"This includes three minor fixes, mostly due to cut-and-paste issues.
The first is a cut and paste issue that changed the amount of stack to
skip when tracing a stack dump from 0 to 6, which basically made the
stack disappear for small stack traces.
The second fix is just removing an unused field in a struct that is no
longer used, and currently just wastes space.
The third is another cut-and-paste fix that had a tracepoint recording
the wrong field (it was recording the previous field a second time)"
* tag 'trace-v4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/dma-buf/fence: Fix timeline str value on fence_annotate_wait_on
ftrace: Remove unused nr_trampolines var
tracing: Fix stacktrace skip depth in trace_buffer_unlock_commit_regs()
minor fixes.
Here's what else is new:
o A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
those that want both.
o New selftest to test the instance create and delete
o Better debug output when ftrace fails
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Merge tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"Not much new with tracing for this release. Mostly just clean ups and
minor fixes.
Here's what else is new:
- A new TRACE_EVENT_FN_COND macro, combining both _FN and _COND for
those that want both.
- New selftest to test the instance create and delete
- Better debug output when ftrace fails"
* tag 'trace-v4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
ftrace: Fix the race between ftrace and insmod
ftrace: Add infrastructure for delayed enabling of module functions
x86: ftrace: Fix the comments for ftrace_modify_code_direct()
tracing: Fix comment to use tracing_on over tracing_enable
metag: ftrace: Fix the comments for ftrace_modify_code
sh: ftrace: Fix the comments for ftrace_modify_code()
ia64: ftrace: Fix the comments for ftrace_modify_code()
ftrace: Clean up ftrace_module_init() code
ftrace: Join functions ftrace_module_init() and ftrace_init_module()
tracing: Introduce TRACE_EVENT_FN_COND macro
tracing: Use seq_buf_used() in seq_buf_to_user() instead of len
bpf: Constify bpf_verifier_ops structure
ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too
ftrace: Remove use of control list and ops
ftrace: Fix output of enabled_functions for showing tramp
ftrace: Fix a typo in comment
ftrace: Show all tramps registered to a record on ftrace_bug()
ftrace: Add variable ftrace_expected for archs to show expected code
ftrace: Add new type to distinguish what kind of ftrace_bug()
tracing: Update cond flag when enabling or disabling a trigger
...
Pull misc vfs updates from Al Viro:
"All kinds of stuff. That probably should've been 5 or 6 separate
branches, but by the time I'd realized how large and mixed that bag
had become it had been too close to -final to play with rebasing.
Some fs/namei.c cleanups there, memdup_user_nul() introduction and
switching open-coded instances, burying long-dead code, whack-a-mole
of various kinds, several new helpers for ->llseek(), assorted
cleanups and fixes from various people, etc.
One piece probably deserves special mention - Neil's
lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets
called without ->i_mutex and tries to avoid ever taking it. That, of
course, means that it's not useful for any directory modifications,
but things like getting inode attributes in nfds readdirplus are fine
with that. I really should've asked for moratorium on lookup-related
changes this cycle, but since I hadn't done that early enough... I
*am* asking for that for the coming cycle, though - I'm going to try
and get conversion of i_mutex to rwsem with ->lookup() done under lock
taken shared.
There will be a patch closer to the end of the window, along the lines
of the one Linus had posted last May - mechanical conversion of
->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
inode_is_locked()/inode_lock_nested(). To quote Linus back then:
-----
| This is an automated patch using
|
| sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
| sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
| sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
| sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
| sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
|
| with a very few manual fixups
-----
I'm going to send that once the ->i_mutex-affecting stuff in -next
gets mostly merged (or when Linus says he's about to stop taking
merges)"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
nfsd: don't hold i_mutex over userspace upcalls
fs:affs:Replace time_t with time64_t
fs/9p: use fscache mutex rather than spinlock
proc: add a reschedule point in proc_readfd_common()
logfs: constify logfs_block_ops structures
fcntl: allow to set O_DIRECT flag on pipe
fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
fs: xattr: Use kvfree()
[s390] page_to_phys() always returns a multiple of PAGE_SIZE
nbd: use ->compat_ioctl()
fs: use block_device name vsprintf helper
lib/vsprintf: add %*pg format specifier
fs: use gendisk->disk_name where possible
poll: plug an unused argument to do_poll
amdkfd: don't open-code memdup_user()
cdrom: don't open-code memdup_user()
rsxx: don't open-code memdup_user()
mtip32xx: don't open-code memdup_user()
[um] mconsole: don't open-code memdup_user_nul()
[um] hostaudio: don't open-code memdup_user()
...
We hit ftrace_bug report when booting Android on a 64bit ATOM SOC chip.
Basically, there is a race between insmod and ftrace_run_update_code.
After load_module=>ftrace_module_init, another thread jumps in to call
ftrace_run_update_code=>ftrace_arch_code_modify_prepare
=>set_all_modules_text_rw, to change all modules
as RW. Since the new module is at MODULE_STATE_UNFORMED, the text attribute
is not changed. Then, the 2nd thread goes ahead to change codes.
However, load_module continues to call complete_formation=>set_section_ro_nx,
then 2nd thread would fail when probing the module's TEXT.
The patch fixes it by using notifier to delay the enabling of ftrace
records to the time when module is at state MODULE_STATE_COMING.
Link: http://lkml.kernel.org/r/567CE628.3000609@intel.com
Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Qiu Peiyang pointed out that there's a race when enabling function tracing
and loading a module. In order to make the modifications of converting nops
in the prologue of functions into callbacks, the text needs to be converted
from read-only to read-write. When enabling function tracing, the text
permission is updated, the functions are modified, and then they are put
back.
When loading a module, the updates to convert function calls to mcount is
done before the module text is set to read-only. But after it is done, the
module text is visible by the function tracer. Thus we have the following
race:
CPU 0 CPU 1
----- -----
start function tracing
set text to read-write
load_module
add functions to ftrace
set module text read-only
update all functions to callbacks
modify module functions too
< Can't it's read-only >
When this happens, ftrace detects the issue and disables itself till the
next reboot.
To fix this, a new DISABLED flag is added for ftrace records, which all
module functions get when they are added. Then later, after the module code
is all set, the records will have the DISABLED flag cleared, and they will
be enabled if any callback wants all functions to be traced.
Note, this doesn't add the delay to later. It simply changes the
ftrace_module_init() to do both the setting of DISABLED records, and then
immediately calls the enable code. This helps with testing this new code as
it has the same behavior as previously. Another change will come after this
to have the ftrace_module_enable() called after the text is set to
read-only.
Cc: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel
panic at t_show.
general protection fault: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 2957 Comm: sh Tainted: G W O 3.14.55-x86_64-01062-gd4acdc7 #2
RIP: 0010:[<ffffffff811375b2>]
[<ffffffff811375b2>] t_show+0x22/0xe0
RSP: 0000:ffff88002b4ebe80 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004
RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1
RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec
R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0
R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570
FS: 0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0
Call Trace:
[<ffffffff811dc076>] seq_read+0x2f6/0x3e0
[<ffffffff811b749b>] vfs_read+0x9b/0x160
[<ffffffff811b7f69>] SyS_read+0x49/0xb0
[<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13
---[ end trace 5bd9eb630614861e ]---
Kernel panic - not syncing: Fatal exception
When the first time find_next calls find_next_mod_format, it should
iterate the trace_bprintk_fmt_list to find the first print format of
the module. However in current code, start_index is smaller than *pos
at first, and code will not iterate the list. Latter container_of will
get the wrong address with former v, which will cause mod_fmt be a
meaningless object and so is the returned mod_fmt->fmt.
This patch will fix it by correcting the start_index. After fixed,
when the first time calls find_next_mod_format, start_index will be
equal to *pos, and code will iterate the trace_bprintk_fmt_list to
get the right module printk format, so is the returned mod_fmt->fmt.
Link: http://lkml.kernel.org/r/5684B900.9000309@intel.com
Cc: stable@vger.kernel.org # 3.12+
Fixes: 102c9323c3 "tracing: Add __tracepoint_string() to export string pointers"
Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The file tracing_enable is obsolete and does not exist anymore. Replace
the comment that references it with the proper tracing_on file.
Link: http://lkml.kernel.org/r/1450787141-45544-1-git-send-email-chuhu@redhat.com
Signed-off-by: Chuyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The start and end variables were only used when ftrace_module_init() was
split up into multiple functions. No need to keep them around after the
merger.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This bpf_verifier_ops structure is never modified, like the other
bpf_verifier_ops structures, so declare it as const.
Done with the help of Coccinelle.
Link: http://lkml.kernel.org/r/1449855359-13724-1-git-send-email-Julia.Lawall@lip6.fr
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Jiri Olsa noted that the change to replace the control_ops did not update
the trampoline for when running perf on a single CPU and with CONFIG_PREEMPT
disabled (where dynamic ops, like perf, can use trampolines directly). The
result was that perf function could be called when RCU is not watching as
well as not handle the ftrace_local_disable().
Modify the ftrace_ops_get_func() to also check the RCU and PER_CPU ops flags
and use the recursive function if they are set. The recursive function is
modified to check those flags and execute the appropriate checks if they are
set.
Link: http://lkml.kernel.org/r/20151201134213.GA14155@krava.brq.redhat.com
Reported-by: Jiri Olsa <jolsa@redhat.com>
Patch-fixed-up-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently perf has its own list function within the ftrace infrastructure
that seems to be used only to allow for it to have per-cpu disabling as well
as a check to make sure that it's not called while RCU is not watching. It
uses something called the "control_ops" which is used to iterate over ops
under it with the control_list_func().
The problem is that this control_ops and control_list_func unnecessarily
complicates the code. By replacing FTRACE_OPS_FL_CONTROL with two new flags
(FTRACE_OPS_FL_RCU and FTRACE_OPS_FL_PER_CPU) we can remove all the code
that is special with the control ops and add the needed checks within the
generic ftrace_list_func().
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When showing all tramps registered to a ftrace record in the file
enabled_functions, it exits the loop with ops == NULL. But then it is
suppose to show the function on the ops->trampoline and
add_trampoline_func() is called with the given ops. But because ops is now
NULL (to exit the loop), it always shows the static trampoline instead of
the one that is really registered to the record.
The call to add_trampoline_func() that shows the trampoline for the given
ops needs to be called at every iteration.
Fixes: 39daa7b9e8 "ftrace: Show all tramps registered to a record on ftrace_bug()"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull perf fixes from Ingo Molnar:
"This tree includes four core perf fixes for misc bugs, three fixes to
x86 PMU drivers, and two updates to old email addresses"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Do not send exit event twice
perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macro
perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on Haswell
perf: Fix PERF_EVENT_IOC_PERIOD deadlock
treewide: Remove old email address
perf/x86: Fix LBR call stack save/restore
perf: Update email address in MAINTAINERS
perf/core: Robustify the perf_cgroup_from_task() RCU checks
perf/core: Fix RCU problem with cgroup context switching code
The set_event_pid filter relies on attaching to the sched_switch and
sched_wakeup tracepoints to see if it should filter the tracing on schedule
tracepoints. By adding the callbacks to sched_wakeup, pids in the
set_event_pid file will trace the wakeups of those tasks with those pids.
But sched_wakeup_new and sched_waking were missed. These two should also be
traced. Luckily, these tracepoints share the same class as sched_wakeup
which means they can use the same pre and post callbacks as sched_wakeup
does.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When an anomaly is detected in the function call modification code,
ftrace_bug() is called to disable function tracing as well as give any
information that may help debug the problem. Currently, only the first found
trampoline that is attached to the failed record is reported. Instead, show
all trampolines that are hooked to it.
Also, not only show the ops pointer but also report the function it calls.
While at it, add this info to the enabled_functions debug file too.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When an anomaly is found while modifying function code, ftrace_bug() is
called which disables the function tracing infrastructure and reports
information about what failed. If the code that is to be replaced does not
match what is expected, then actual code is shown. Currently there is no
arch generic way to show what was expected.
Add a new variable pointer calld ftrace_expected that the arch code can set
to point to what it expected so that ftrace_bug() can report the actual text
as well as the text that was expected to be there.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ftrace function hook utility has several internal checks to make sure
that whatever it modifies is exactly what it expects to be modifying. This
is essential as modifying running code can be extremely dangerous to the
system.
When an anomaly is detected, ftrace_bug() is called which sends a splat to
the console and disables function tracing. There's some extra information
that is printed to help diagnose the issue.
One thing that is missing though is output of what ftrace was doing at the
time of the crash. Was it updating a call site or perhaps converting a call
site to a nop? A new global enum variable is created to state what ftrace
was doing at the time of the anomaly, and this is reported in ftrace_bug().
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When a trigger is enabled, the cond flag should be set beforehand,
otherwise a trigger that's expecting to process a trace record
(e.g. one with post_trigger set) could be invoked without one.
Likewise a trigger's cond flag should be reset after it's disabled,
not before.
Link: http://lkml.kernel.org/r/a420b52a67b1c2d3cab017914362d153255acb99.1448303214.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When crossing over to a new page, commit the current work. This will allow
readers to get data with less latency, and also simplifies the work to get
timestamps working for interrupted events.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The first commit of a buffer page updates the timestamp of that page. No
need to have the update to the next page add the timestamp too. It will only
be replaced by the first commit on that page anyway.
Only update to a page if it contains an event.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As cpu_buffer->tail_page may be modified by interrupts at almost any time,
the flow of logic is very important. Do not let gcc get smart with
re-reading cpu_buffer->tail_page by adding READ_ONCE() around most of its
accesses.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Commit fcc742eaad "ring-buffer: Add event descriptor to simplify passing
data" added a descriptor that holds various data instead of passing around
several variables through parameters. The problem was that one of the
parameters was modified in a function and the code was designed not to have
an effect on that modified parameter. Now that the parameter is a
descriptor and any modifications to it are non-volatile, the size of the
data could be unnecessarily expanded.
Remove the extra space added if a timestamp was added and the event went
across the page.
Cc: stable@vger.kernel.org # 4.3+
Fixes: fcc742eaad "ring-buffer: Add event descriptor to simplify passing data"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Do not update the read stamp after swapping out the reader page from the
write buffer. If the reader page is swapped out of the buffer before an
event is written to it, then the read_stamp may get an out of date
timestamp, as the page timestamp is updated on the first commit to that
page.
rb_get_reader_page() only returns a page if it has an event on it, otherwise
it will return NULL. At that point, check if the page being returned has
events and has not been read yet. Then at that point update the read_stamp
to match the time stamp of the reader page.
Cc: stable@vger.kernel.org # 2.6.30+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There were still a number of references to my old Red Hat email
address in the kernel source. Remove these while keeping the
Red Hat copyright notices intact.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
One patch is needed to make tracing work without debugfs now that tracing
uses its own tracefs.
The second is removing an unused variable.
The third is fixing a warning about unused variables when MAX_TRACER is
not configured. Note, this warning shows up in gcc 6.0, but does not show
up in gcc 4.9, as it seems that gcc does not complain about constants
not being used.
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Merge tag 'trace-v4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull trace cleanups from Steven Rostedt:
"This contains three more clean up patches.
One patch is needed to make tracing work without debugfs now that
tracing uses its own tracefs.
The second is removing an unused variable.
The third is fixing a warning about unused variables when MAX_TRACER
is not configured. Note, this warning shows up in gcc 6.0, but does
not show up in gcc 4.9, as it seems that gcc does not complain about
constants not being used"
* tag 'trace-v4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: #ifdef out uses of max trace when CONFIG_TRACER_MAX_TRACE is not set
tracing: Remove unused ftrace_cpu_disabled per cpu variable
tracing: Make tracing work when debugfs is not configured in
Pull networking fixes from David Miller:
1) Fix null deref in xt_TEE netfilter module, from Eric Dumazet.
2) Several spots need to get to the original listner for SYN-ACK
packets, most spots got this ok but some were not. Whilst covering
the remaining cases, create a helper to do this. From Eric Dumazet.
3) Missiing check of return value from alloc_netdev() in CAIF SPI code,
from Rasmus Villemoes.
4) Don't sleep while != TASK_RUNNING in macvtap, from Vlad Yasevich.
5) Use after free in mvneta driver, from Justin Maggard.
6) Fix race on dst->flags access in dst_release(), from Eric Dumazet.
7) Add missing ZLIB_INFLATE dependency for new qed driver. From Arnd
Bergmann.
8) Fix multicast getsockopt deadlock, from WANG Cong.
9) Fix deadlock in btusb, from Kuba Pawlak.
10) Some ipv6_add_dev() failure paths were not cleaning up the SNMP6
counter state. From Sabrina Dubroca.
11) Fix packet_bind() race, which can cause lost notifications, from
Francesco Ruggeri.
12) Fix MAC restoration in qlcnic driver during bonding mode changes,
from Jarod Wilson.
13) Revert bridging forward delay change which broke libvirt and other
userspace things, from Vlad Yasevich.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
Revert "bridge: Allow forward delay to be cfgd when STP enabled"
bpf_trace: Make dependent on PERF_EVENTS
qed: select ZLIB_INFLATE
net: fix a race in dst_release()
net: mvneta: Fix memory use after free.
net: Documentation: Fix default value tcp_limit_output_bytes
macvtap: Resolve possible __might_sleep warning in macvtap_do_read()
mvneta: add FIXED_PHY dependency
net: caif: check return value of alloc_netdev
net: hisilicon: NET_VENDOR_HISILICON should depend on HAS_DMA
drivers: net: xgene: fix RGMII 10/100Mb mode
netfilter: nft_meta: use skb_to_full_sk() helper
net_sched: em_meta: use skb_to_full_sk() helper
sched: cls_flow: use skb_to_full_sk() helper
netfilter: xt_owner: use skb_to_full_sk() helper
smack: use skb_to_full_sk() helper
net: add skb_to_full_sk() helper and use it in selinux_netlbl_skbuff_setsid()
bpf: doc: correct arch list for supported eBPF JIT
dwc_eth_qos: Delete an unnecessary check before the function call "of_node_put"
bonding: fix panic on non-ARPHRD_ETHER enslave failure
...
Arnd Bergmann reported:
In my ARM randconfig tests, I'm getting a build error for
newly added code in bpf_perf_event_read and bpf_perf_event_output
whenever CONFIG_PERF_EVENTS is disabled:
kernel/trace/bpf_trace.c: In function 'bpf_perf_event_read':
kernel/trace/bpf_trace.c:203:11: error: 'struct perf_event' has no member named 'oncpu'
if (event->oncpu != smp_processor_id() ||
^
kernel/trace/bpf_trace.c:204:11: error: 'struct perf_event' has no member named 'pmu'
event->pmu->count)
This can happen when UPROBE_EVENT is enabled but KPROBE_EVENT
is disabled. I'm not sure if that is a configuration we care
about, otherwise we could prevent this case from occuring by
adding Kconfig dependencies.
Looking at this further, it's really that UPROBE_EVENT enables PERF_EVENTS.
By just having BPF_EVENTS depend on PERF_EVENTS, then all is fine.
Link: http://lkml.kernel.org/r/4525348.Aq9YoXkChv@wuerfel
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
tracing_max_lat_fops is used only when TRACER_MAX_TRACE enabled, so also
swith the related code. The related warning with defconfig under x86_64:
CC kernel/trace/trace.o
kernel/trace/trace.c:5466:37: warning: ‘tracing_max_lat_fops’ defined but not used [-Wunused-const-variable]
static const struct file_operations tracing_max_lat_fops = {
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since the ring buffer is lockless, there is no need to disable ftrace on
CPU. And no one doing so: after commit 68179686ac ("tracing: Remove
ftrace_disable/enable_cpu()") ftrace_cpu_disabled stays the same after
initialization, nothing changes it.
ftrace_cpu_disabled shouldn't be used by any external module since it
disables only function and graph_function tracers but not any other
tracer.
Link: http://lkml.kernel.org/r/1446836846-22239-1-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
stable tags to them. I searched through my INBOX just as the merge window
opened and found lots of patches to pull. I ran them through all my tests
and they were in linux-next for a few days.
Features added this release:
----------------------------
o Module globbing. You can now filter function tracing to several
modules. # echo '*:mod:*snd*' > set_ftrace_filter (Dmitry Safonov)
o Tracer specific options are now visible even when the tracer is not
active. It was rather annoying that you can only see and modify tracer
options after enabling the tracer. Now they are in the options/ directory
even when the tracer is not active. Although they are still only visible
when the tracer is active in the trace_options file.
o Trace options are now per instance (although some of the tracer specific
options are global)
o New tracefs file: set_event_pid. If any pid is added to this file, then
all events in the instance will filter out events that are not part of
this pid. sched_switch and sched_wakeup events handle next and the wakee
pids.
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Merge tag 'trace-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracking updates from Steven Rostedt:
"Most of the changes are clean ups and small fixes. Some of them have
stable tags to them. I searched through my INBOX just as the merge
window opened and found lots of patches to pull. I ran them through
all my tests and they were in linux-next for a few days.
Features added this release:
----------------------------
- Module globbing. You can now filter function tracing to several
modules. # echo '*:mod:*snd*' > set_ftrace_filter (Dmitry Safonov)
- Tracer specific options are now visible even when the tracer is not
active. It was rather annoying that you can only see and modify
tracer options after enabling the tracer. Now they are in the
options/ directory even when the tracer is not active. Although
they are still only visible when the tracer is active in the
trace_options file.
- Trace options are now per instance (although some of the tracer
specific options are global)
- New tracefs file: set_event_pid. If any pid is added to this file,
then all events in the instance will filter out events that are not
part of this pid. sched_switch and sched_wakeup events handle next
and the wakee pids"
* tag 'trace-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (68 commits)
tracefs: Fix refcount imbalance in start_creating()
tracing: Put back comma for empty fields in boot string parsing
tracing: Apply tracer specific options from kernel command line.
tracing: Add some documentation about set_event_pid
ring_buffer: Remove unneeded smp_wmb() before wakeup of reader benchmark
tracing: Allow dumping traces without tracking trace started cpus
ring_buffer: Fix more races when terminating the producer in the benchmark
ring_buffer: Do no not complete benchmark reader too early
tracing: Remove redundant TP_ARGS redefining
tracing: Rename max_stack_lock to stack_trace_max_lock
tracing: Allow arch-specific stack tracer
recordmcount: arm64: Replace the ignored mcount call into nop
recordmcount: Fix endianness handling bug for nop_mcount
tracepoints: Fix documentation of RCU lockdep checks
tracing: ftrace_event_is_function() can return boolean
tracing: is_legal_op() can return boolean
ring-buffer: rb_event_is_commit() can return boolean
ring-buffer: rb_per_cpu_empty() can return boolean
ring_buffer: ring_buffer_empty{cpu}() can return boolean
ring-buffer: rb_is_reader_page() can return boolean
...
Currently tracing_init_dentry() returns -ENODEV when debugfs is not
configured in, which causes tracefs not populated with tracing files and
directories, so we will get an empty directory even after we manually
mount tracefs.
We can make tracing_init_dentry() return NULL if debugfs is not
configured in and can manually mount tracefs. But return -ENODEV
if debugfs is configured in but not initialized or failed to create
automount point as that would break backward compatibility with older
tools.
Link: http://lkml.kernel.org/r/1446797056-11683-1-git-send-email-hello.wjx@gmail.com
Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull core block updates from Jens Axboe:
"This is the core block pull request for 4.4. I've got a few more
topic branches this time around, some of them will layer on top of the
core+drivers changes and will come in a separate round. So not a huge
chunk of changes in this round.
This pull request contains:
- Enable blk-mq page allocation tracking with kmemleak, from Catalin.
- Unused prototype removal in blk-mq from Christoph.
- Cleanup of the q->blk_trace exchange, using cmpxchg instead of two
xchg()'s, from Davidlohr.
- A plug flush fix from Jeff.
- Also from Jeff, a fix that means we don't have to update shared tag
sets at init time unless we do a state change. This cuts down boot
times on thousands of devices a lot with scsi/blk-mq.
- blk-mq waitqueue barrier fix from Kosuke.
- Various fixes from Ming:
- Fixes for segment merging and splitting, and checks, for
the old core and blk-mq.
- Potential blk-mq speedup by marking ctx pending at the end
of a plug insertion batch in blk-mq.
- direct-io no page dirty on kernel direct reads.
- A WRITE_SYNC fix for mpage from Roman"
* 'for-4.4/core' of git://git.kernel.dk/linux-block:
blk-mq: avoid excessive boot delays with large lun counts
blktrace: re-write setting q->blk_trace
blk-mq: mark ctx as pending at batch in flush plug path
blk-mq: fix for trace_block_plug()
block: check bio_mergeable() early before merging
blk-mq: check bio_mergeable() early before merging
block: avoid to merge splitted bio
block: setup bi_phys_segments after splitting
block: fix plug list flushing for nomerge queues
blk-mq: remove unused blk_mq_clone_flush_request prototype
blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read
fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
block: kmemleak: Track the page allocations for struct request
Pull networking updates from David Miller:
Changes of note:
1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell.
2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from
David Ahern.
3) Allow the user to ask for the statistics to be filtered out of
ipv4/ipv6 address netlink dumps. From Sowmini Varadhan.
4) More work to pass the network namespace context around deep into
various packet path APIs, starting with the netfilter hooks. From
Eric W Biederman.
5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas
Richter.
6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng.
7) Support Very High Throughput in wireless MESH code, from Bob
Copeland.
8) Allow setting the ageing_time in switchdev/rocker. From Scott
Feldman.
9) Properly autoload L2TP type modules, from Stephen Hemminger.
10) Fix and enable offload features by default in 8139cp driver, from
David Woodhouse.
11) Support both ipv4 and ipv6 sockets in a single vxlan device, from
Jiri Benc.
12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning
Opstad.
13) Fix IPSEC flowcache overflows on large systems, from Steffen
Klassert.
14) Convert bridging to track VLANs using rhashtable entries rather than
a bitmap. From Nikolay Aleksandrov.
15) Make TCP listener handling completely lockless, this is a major
accomplishment. Incoming request sockets now live in the
established hash table just like any other socket too.
From Eric Dumazet.
15) Provide more bridging attributes to netlink, from Nikolay
Aleksandrov.
16) Use hash based algorithm for ipv4 multipath routing, this was very
long overdue. From Peter Nørlund.
17) Several y2038 cures, mostly avoiding timespec. From Arnd Bergmann.
18) Allow non-root execution of EBPF programs, from Alexei Starovoitov.
19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet. This
influences the port binding selection logic used by SO_REUSEPORT.
20) Add ipv6 support to VRF, from David Ahern.
21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko.
22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen.
23) Implement RACK loss recovery in TCP, from Yuchung Cheng.
24) Support multipath routes in MPLS, from Roopa Prabhu.
25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric
Dumazet.
26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and
Sudarsana Kalluru.
27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic
Sowa.
28) Support ipv6 geneve tunnels, from John W Linville.
29) Add flood control support to switchdev layer, from Ido Schimmel.
30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from
Hannes Frederic Sowa.
31) Support persistent maps and progs in bpf, from Daniel Borkmann.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits)
sh_eth: use DMA barriers
switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion
net: sched: kill dead code in sch_choke.c
irda: Delete an unnecessary check before the function call "irlmp_unregister_service"
net: dsa: mv88e6xxx: include DSA ports in VLANs
net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports
net/core: fix for_each_netdev_feature
vlan: Invoke driver vlan hooks only if device is present
arcnet/com20020: add LEDS_CLASS dependency
bpf, verifier: annotate verbose printer with __printf
dp83640: Only wait for timestamps for packets with timestamping enabled.
ptp: Change ptp_class to a proper bitmask
dp83640: Prune rx timestamp list before reading from it
dp83640: Delay scheduled work.
dp83640: Include hash in timestamp/packet matching
ipv6: fix tunnel error handling
net/mlx5e: Fix LSO vlan insertion
net/mlx5e: Re-eanble client vlan TX acceleration
net/mlx5e: Return error in case mlx5e_set_features() fails
net/mlx5e: Don't allow more than max supported channels
...
Both early_enable_events() and apply_trace_boot_options() parse a boot
string that may get parsed later on. They both use strsep() which converts a
comma into a nul character. To still allow the boot string to be parsed
again the same way, the nul character gets converted back to a comma after
the token is processed.
The problem is that these two functions check for an empty parameter (two
commas in a row ",,"), and continue the loop if the parameter is empty, but
fails to place the comma back. In this case, the second parsing will end at
this blank field, and not process fields afterward.
In most cases, users should not have an empty field, but if its going to be
checked, the code might as well be correct.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently, the trace_options parameter is only applied in
tracer_alloc_buffers() when global_trace.current_trace is nop_trace,
so a tracer specific option will not be applied even when the specific
tracer is also enabled from kernel command line. For example, the
'func_stack_trace' option can't be enabled with the following kernel
parameter:
ftrace=function ftrace_filter=kfree trace_options=func_stack_trace
We can enable tracer specific options by simply apply the options again
if the specific tracer is also supplied from command line and started
in register_tracer().
To make trace_boot_options_buf can be parsed again, a comma and a space
is put back if they were replaced by strsep and strstrip respectively.
Also make register_tracer() be __init to access the __init data, and
in fact register_tracer is only called from __init code.
Link: http://lkml.kernel.org/r/1446599669-9294-1-git-send-email-hello.wjx@gmail.com
Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull scheduler changes from Ingo Molnar:
"The main changes in this cycle were:
- sched/fair load tracking fixes and cleanups (Byungchul Park)
- Make load tracking frequency scale invariant (Dietmar Eggemann)
- sched/deadline updates (Juri Lelli)
- stop machine fixes, cleanups and enhancements for bugs triggered by
CPU hotplug stress testing (Oleg Nesterov)
- scheduler preemption code rework: remove PREEMPT_ACTIVE and related
cleanups (Peter Zijlstra)
- Rework the sched_info::run_delay code to fix races (Peter Zijlstra)
- Optimize per entity utilization tracking (Peter Zijlstra)
- ... misc other fixes, cleanups and smaller updates"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS
sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
sched: Start stopper early
stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark()
stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled
stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works()
stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
sched/x86: Fix typo in __switch_to() comments
sched/core: Remove a parameter in the migrate_task_rq() function
sched/core: Drop unlikely behind BUG_ON()
sched/core: Fix task and run queue sched_info::run_delay inconsistencies
sched/numa: Fix task_tick_fair() from disabling numa_balancing
sched/core: Add preempt_count invariant check
sched/core: More notrace annotations
sched/core: Kill PREEMPT_ACTIVE
sched/core, sched/x86: Kill thread_info::saved_preempt_count
sched/core: Simplify preempt_count tests
sched/core: Robustify preemption leak checks
sched/core: Stop setting PREEMPT_ACTIVE
...
wake_up_process() has a memory barrier before doing anything, thus adding a
memory barrier before calling it is redundant.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
We don't init iter->started when dumping the ftrace buffer, and there's no
real need to do so - so allow skipping that check if the iter doesn't have
an initialized ->started cpumask.
Link: http://lkml.kernel.org/r/1441385156-27279-1-git-send-email-sasha.levin@oracle.com
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The commit b44754d826 ("ring_buffer: Allow to exit the ring
buffer benchmark immediately") added a hack into ring_buffer_producer()
that set @kill_test when kthread_should_stop() returned true. It improved
the situation a lot. It stopped the kthread in most cases because
the producer spent most of the time in the patched while cycle.
But there are still few possible races when kthread_should_stop()
is set outside of the cycle. Then we do not set @kill_test and
some other checks pass.
This patch adds a better fix. It renames @test_kill/TEST_KILL() into
a better descriptive @test_error/TEST_ERROR(). Also it introduces
break_test() function that checks for both @test_error and
kthread_should_stop().
The new function is used in the producer when the check for @test_error
is not enough. It is not used in the consumer because its state
is manipulated by the producer via the "reader_finish" variable.
Also we add a missing check into ring_buffer_producer_thread()
between setting TASK_INTERRUPTIBLE and calling schedule_timeout().
Otherwise, we might miss a wakeup from kthread_stop().
Link: http://lkml.kernel.org/r/1441629518-32712-3-git-send-email-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It seems that complete(&read_done) might be called too early
in some situations.
1st scenario:
-------------
CPU0 CPU1
ring_buffer_producer_thread()
wake_up_process(consumer);
wait_for_completion(&read_start);
ring_buffer_consumer_thread()
complete(&read_start);
ring_buffer_producer()
# producing data in
# the do-while cycle
ring_buffer_consumer();
# reading data
# got error
# set kill_test = 1;
set_current_state(
TASK_INTERRUPTIBLE);
if (reader_finish) # false
schedule();
# producer still in the middle of
# do-while cycle
if (consumer && !(cnt % wakeup_interval))
wake_up_process(consumer);
# spurious wakeup
while (!reader_finish &&
!kill_test)
# leaving because
# kill_test == 1
reader_finish = 0;
complete(&read_done);
1st BANG: We might access uninitialized "read_done" if this is the
the first round.
# producer finally leaving
# the do-while cycle because kill_test == 1;
if (consumer) {
reader_finish = 1;
wake_up_process(consumer);
wait_for_completion(&read_done);
2nd BANG: This will never complete because consumer already did
the completion.
2nd scenario:
-------------
CPU0 CPU1
ring_buffer_producer_thread()
wake_up_process(consumer);
wait_for_completion(&read_start);
ring_buffer_consumer_thread()
complete(&read_start);
ring_buffer_producer()
# CPU3 removes the module <--- difference from
# and stops producer <--- the 1st scenario
if (kthread_should_stop())
kill_test = 1;
ring_buffer_consumer();
while (!reader_finish &&
!kill_test)
# kill_test == 1 => we never go
# into the top level while()
reader_finish = 0;
complete(&read_done);
# producer still in the middle of
# do-while cycle
if (consumer && !(cnt % wakeup_interval))
wake_up_process(consumer);
# spurious wakeup
while (!reader_finish &&
!kill_test)
# leaving because kill_test == 1
reader_finish = 0;
complete(&read_done);
BANG: We are in the same "bang" situations as in the 1st scenario.
Root of the problem:
--------------------
ring_buffer_consumer() must complete "read_done" only when "reader_finish"
variable is set. It must not be skipped due to other conditions.
Note that we still must keep the check for "reader_finish" in a loop
because there might be spurious wakeups as described in the
above scenarios.
Solution:
----------
The top level cycle in ring_buffer_consumer() will finish only when
"reader_finish" is set. The data will be read in "while-do" cycle
so that they are not read after an error (kill_test == 1)
or a spurious wake up.
In addition, "reader_finish" is manipulated by the producer thread.
Therefore we add READ_ONCE() to make sure that the fresh value is
read in each cycle. Also we add the corresponding barrier
to synchronize the sleep check.
Next we set the state back to TASK_RUNNING for the situation where we
did not sleep.
Just from paranoid reasons, we initialize both completions statically.
This is safer, in case there are other races that we are unaware of.
As a side effect we could remove the memory barrier from
ring_buffer_producer_thread(). IMHO, this was the reason for
the barrier. ring_buffer_reset() uses spin locks that should
provide the needed memory barrier for using the buffer.
Link: http://lkml.kernel.org/r/1441629518-32712-2-git-send-email-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
TP_ARGS is not used anywhere in trace.h nor trace_entries.h
Firstly, I left just #undef TP_ARGS and had no errors - remove it.
Link: http://lkml.kernel.org/r/1446576560-14085-1-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Now that max_stack_lock is a global variable, it requires a naming
convention that is unlikely to collide. Rename it to the same naming
convention that the other stack_trace variables have.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A stack frame may be used in a different way depending on cpu architecture.
Thus it is not always appropriate to slurp the stack contents, as current
check_stack() does, in order to calcurate a stack index (height) at a given
function call. At least not on arm64.
In addition, there is a possibility that we will mistakenly detect a stale
stack frame which has not been overwritten.
This patch makes check_stack() a weak function so as to later implement
arch-specific version.
Link: http://lkml.kernel.org/r/1446182741-31019-5-git-send-email-takahiro.akashi@linaro.org
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make ftrace_event_is_function() return bool to improve readability
due to this particular function only using either one or zero as its
return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-9-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make is_legal_op() return bool to improve readability due to this particular
function only using either one or zero as its return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-8-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make rb_event_is_commit() return bool to improve readability
due to this particular function only using either one or zero as its
return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-7-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make rb_is_reader_page() return bool to improve readability due to this
particular function only using either true or false as its return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-4-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch makes report_latency return bool due to this
particular function only using either one or zero as its
return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-3-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch makes report_latency return bool to improve readability,
indicating whether this new latency should be reported/recorded.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-2-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Update instancd_rmdir to use tracefs_remove_recursive instead of
debugfs_remove_recursive.This was left in the transition from debugfs
to tracefs.
Link: http://lkml.kernel.org/r/1445169490-18315-2-git-send-email-hello.wjx@gmail.com
Cc: stable@vger.kernel.org # 4.1+
Fixes: 8434dc9340 ("tracing: Convert the tracing facility over to use tracefs")
Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There's no need to record the time tracepoints take when tracing is off.
This is because:
1) We cannot see these records since ring_buffer record is off at that
moment.
2) If tracing is off and benchmark tracepoint is enabled, the time
tracepoint takes is fewer than the same situation when tracing is on,
since the tracepoints need to be wrote into ring_buffer, it would
take more time. If turn on tracing at this moment, the average and
standard deviation cannot exactly present the time that tracepoints
take to write data into ring_buffer.
Link: http://lkml.kernel.org/r/1445947933-27955-1-git-send-email-zhang.chunyan@linaro.org
Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
For the case where pids are already in set_event_pid, and one is added or
removed then each CPU should be checked to make sure that the new or old pid
is on or not on a CPU.
For example:
# echo 123 >> set_event_pid
or
# echo '!123' >> set_event_pid
Link: http://lkml.kernel.org/r/20151030061643.GA19480@cac
Suggested-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This is really about simplifying the double xchg patterns into
a single cmpxchg, with the same logic. Other than the immediate
cleanup, there are some subtleties this change deals with:
(i) While the load of the old bt is fully ordered wrt everything,
ie:
old_bt = xchg(&q->blk_trace, bt); [barrier]
if (old_bt)
(void) xchg(&q->blk_trace, old_bt); [barrier]
blk_trace could still be changed between the xchg and the old_bt
load. Note that this description is merely theoretical and afaict
very small, but doing everything in a single context with cmpxchg
closes this potential race.
(ii) Ordering guarantees are obviously kept with cmpxchg.
(iii) Gets rid of the hacky-by-nature (void)xchg pattern.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
eviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
exported perf symbols are GPL only, mark eBPF helper functions
used in tracing as GPL only as well.
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix safety checks for bpf_perf_event_read():
- only non-inherited events can be added to perf_event_array map
(do this check statically at map insertion time)
- dynamically check that event is local and !pmu->count
Otherwise buggy bpf program can cause kernel splat.
Also fix error path after perf_event_attrs()
and remove redundant 'extern'.
Fixes: 35578d7984 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
p_start() and p_stop() are seq_file functions that match. Teach sparse to
know that rcu_read_lock_sched() that is taken by p_start() is released by
p_stop.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
My tests found that if a task is running but not filtered when set_event_pid
is modified, then it can still be traced.
Call on_each_cpu() to check if the current running task should be filtered
and update the per cpu flags of tr->data appropriately.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add the necessary hooks to use the pids loaded in set_event_pid to filter
all the events enabled in the tracing instance that match the pids listed.
Two probes are added to both sched_switch and sched_wakeup tracepoints to be
called before other probes are called and after the other probes are called.
The first is used to set the necessary flags to let the probes know to test
if they should be traced or not.
The sched_switch pre probe will set the "ignore_pid" flag if neither the
previous or next task has a matching pid.
The sched_switch probe will set the "ignore_pid" flag if the next task
does not match the matching pid.
The pre probe allows for probes tracing sched_switch to be traced if
necessary.
The sched_wakeup pre probe will set the "ignore_pid" flag if neither the
current task nor the wakee task has a matching pid.
The sched_wakeup post probe will set the "ignore_pid" flag if the current
task does not have a matching pid.
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Create a tracing directory called set_event_pid, which currently has no
function, but will be used to filter all events for the tracing instance or
the pids that are added to the file.
The reason no functionality is added with this commit is that this commit
focuses on the creation and removal of the pids in a safe manner. And tests
can be made against this change to make sure things are correct before
hooking features to the list of pids.
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This helper is used to send raw data from eBPF program into
special PERF_TYPE_SOFTWARE/PERF_COUNT_SW_BPF_OUTPUT perf_event.
User space needs to perf_event_open() it (either for one or all cpus) and
store FD into perf_event_array (similar to bpf_perf_event_read() helper)
before eBPF program can send data into it.
Today the programs triggered by kprobe collect the data and either store
it into the maps or print it via bpf_trace_printk() where latter is the debug
facility and not suitable to stream the data. This new helper replaces
such bpf_trace_printk() usage and allows programs to have dedicated
channel into user space for post-processing of the raw data collected.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both start_branch_trace() and stop_branch_trace() are used in only one
location, and are both static. As they are small functions there is no
need to keep them separated out.
Link: http://lkml.kernel.org/r/1445000689-32596-1-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a new options to trace Kconfig, CONFIG_TRACING_EVENTS_GPIO, that is
used for enabling/disabling compilation of gpio function trace events.
Link: http://lkml.kernel.org/r/1438432079-11704-4-git-send-email-tal.shorer@gmail.com
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The code in stack tracer should not be executed within an NMI as it grabs
spinlocks and stack tracing an NMI gives the possibility of causing a
deadlock. Although this is safe on x86_64, because it does not perform stack
traces when the task struct stack is not in use (interrupts and NMIs), it
may be an issue for NMIs on i386 and other archs that use the same stack as
the NMI.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Extend module command for function filter selection with globbing.
It uses the same globbing as function filter.
sh# echo '*alloc*:mod:*' > set_ftrace_filter
Will trace any function with the letters 'alloc' in the name in any
module but not in kernel.
sh# echo '!*alloc*:mod:ipv6' >> set_ftrace_filter
Will prevent from tracing functions with 'alloc' in the name from module
ipv6 (do not forget to append to set_ftrace_filter file).
sh# echo '*alloc*:mod:!ipv6' > set_ftrace_filter
Will trace functions with 'alloc' in the name from kernel and any
module except ipv6.
sh# echo '*alloc*:mod:!*' > set_ftrace_filter
Will trace any function with the letters 'alloc' in the name only from
kernel, but not from any module.
sh# echo '*:mod:!*' > set_ftrace_filter
or
sh# echo ':mod:!' > set_ftrace_filter
Will trace every function in the kernel, but will not trace functions
from any module.
sh# echo '*:mod:*' > set_ftrace_filter
or
sh# echo ':mod:' > set_ftrace_filter
As the opposite will trace all functions from all modules, but not from
kernel.
sh# echo '*:mod:*snd*' > set_ftrace_filter
Will trace your sound drivers only (if any).
Link: http://lkml.kernel.org/r/1443545176-3215-4-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ Made format changes ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
ftrace_match parameters are very related and I reduce the number of local
variables & parameters with it.
This is also preparation for module globbing as it would introduce more
realated variables & parameters.
Link: http://lkml.kernel.org/r/1443545176-3215-3-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ Made some formatting changes ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The stack tracer was triggering the WARN_ON() in module.c:
static void module_assert_mutex_or_preempt(void)
{
#ifdef CONFIG_LOCKDEP
if (unlikely(!debug_locks))
return;
WARN_ON(!rcu_read_lock_sched_held() &&
!lockdep_is_held(&module_mutex));
#endif
}
The reason is that the stack tracer traces all function calls, and some of
those calls happen while exiting or entering user space and idle. Some of
these functions are called after RCU had already stopped watching, as RCU
does not watch userspace or idle CPUs.
If a max stack is hit, then the save_stack_trace() is called, which will
check module addresses and call module_assert_mutex_or_preempt(), and then
trigger the warning. Sad part is, the warning itself will also do a stack
trace and tigger the same warning. That probably should be fixed.
The warning was added by 0be964be0d "module: Sanitize RCU usage and
locking" but this bug has probably been around longer. But it's unlikely to
cause much harm, but the new warning causes the system to lock up.
Cc: stable@vger.kernel.org # 4.2+
Cc: Peter Zijlstra <peterz@infradead.org>
Cc:"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
"Not" is too abstract variable name - changed to clear_filter.
Removed ftrace_match_module_records function: comparison with !* or *
not does the general code in filter_parse_regex() as it works without
mod command for
sh# echo '!*' > /sys/kernel/debug/tracing/set_ftrace_filter
Link: http://lkml.kernel.org/r/1443545176-3215-2-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
By now there isn't any subcommand for mod.
Before:
sh$ echo '*:mod:ipv6:a' > set_ftrace_filter
sh$ echo '*:mod:ipv6' > set_ftrace_filter
had the same results, but now first will result in:
sh$ echo '*:mod:ipv6:a' > set_ftrace_filter
-bash: echo: write error: Invalid argument
Also, I clarified ftrace_mod_callback code a little.
Link: http://lkml.kernel.org/r/1443545176-3215-1-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
[ converted 'if (ret == 0)' to 'if (!ret)' ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
__trace_sched_switch_state() is the last remaining PREEMPT_ACTIVE
user, move trace_sched_switch() from prepare_task_switch() to
__schedule() and propagate the @preempt argument.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
To cover the common case of sorting an array of pointers, Daniel
Wagner recently modified the library sort() to use a specific swap
function for size==8, in addition to the size==4 case which was
already handled. Since sizeof(long) is either 4 or 8,
ftrace_swap_ips() is redundant and we can just let sort() pick an
appropriate and fast swap callback.
Link: http://lkml.kernel.org/r/1441834023-13130-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The kernel now has kstrdup_const/kfree_const for reusing .rodata
(typically string literals) when possible; there's no reason to
duplicate that logic in the tracing system. Moreover, as the comment
above core_kernel_data states, it may not always return true for
.rodata - that is for example the case on x86_64, where we thus end up
kstrdup'ing all the passed-in strings.
Arguably, testing for .rodata explicitly (as kstrdup_const does) is
also more correct: I don't think one is supposed to be able to change
the name after creating the event_subsystem by passing the address of
a static char (but non-const) array.
Link: http://lkml.kernel.org/r/1441833841-12955-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add the tracer options to instances options directory as well. Only add the
options for tracers that are allowed to be enabled by an instance. But note,
that tracer options are global. That is, tracer options enabled in an
instance, also take affect at the top level and in other instances.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow instances to have their own options, at least for the core options
(non tracer specific ones). There are a few global options that should not
be added to instances, like enabling of trace_printk, and the sched comm
recording, which do not have a specific trace instance associated to them.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In preparation for the multi buffer instances to have their own trace_flags,
the check in ftrace_trace_stack() needs to test the trace_array descriptor
flag that is for the current event, not the global_trace descriptor.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In preparation of having the multi buffer instances having their own trace
option flags, the trace option files needs a way to not only pass in the
flag they represent, but also the trace_array descriptor.
A new field is added to the trace_array descriptor called trace_flags_index,
which is a 32 byte character array representing a bit. This array is simply
filled with the index of the array, where
index_array[n] = n;
Then the address of this array is passed to the file callbacks instead of
the index of the flag index. Then to retrieve both the flag index and the
trace_array descriptor:
data is the passed in argument.
index = *(unsigned char *)data;
data -= index;
/* Now data points to the address of the array in the trace_array */
tr = container_of(data, struct trace_array, trace_flags_index);
Suggested-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In preparation to make trace options per instance, the global trace_flags
needs to be moved from being a global variable to a field within the trace
instance trace_array structure.
There's still more work to do, as there's some functions that use
trace_flags without passing in a way to get to the current_trace array. For
those, the global_trace is used directly (from trace.c). This includes
setting and clearing the trace_flags. This means that when a new instance is
created, it just gets the trace_flags of the global_trace and will not be
able to modify them. Depending on the functions that have access to the
trace_array, the flags of an instance may not affect parts of its trace,
where the global_trace is used. These will be fixed in future changes.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The sleep-time and graph-time options are only for the function graph tracer
and are not used by anything else. As tracer options are now visible when
the tracer is not activated, its better to move the function graph specific
tracer options into the function graph tracer.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In the effort to move the global trace_flags to the tracing instances, the
direct access to trace_flags must be removed from trace_printk.c
Instead, add a new trace_printk_enabled boolean that is set by a new access
function trace_printk_control(), that will enable or disable trace_printk.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a enum that denotes the last bit of the trace_flags and have a
BUILD_BUG_ON(last_bit > 32).
If we add more bits than we have in trace_flags, the kernel wont build.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There are options that are unique to a specific tracer (like function and
function graph). Currently, these options are only visible in the options
directory when the tracer is enabled.
This has been a pain, especially for something like the func_stack_trace
option that if used inappropriately, could bring the system to a crawl. But
the only way to see it, is to enable the function tracer.
For example, if one had done:
# cd /sys/kernel/tracing
# echo __schedule > set_ftrace_filter
# echo 1 > options/func_stack_trace
# echo function > current_tracer
The __schedule call will be traced and a stack trace will also be recorded
there. Now when you were done, you may do...
# echo nop > current_tracer
# echo > set_ftrace_filter
But you forgot to disable the func_stack_trace. The only way to disable it
is to re-enable function tracing first. If you do not add a filter to
set_ftrace_filter and just do:
# echo function > current_tracer
Now you would be performing a stack trace on *every* function! On some
systems, that causes a live lock. Others may take a few minutes to fix your
mistake.
Having the func_stack_trace option visible allows you to check it and
disable it before enabling the funtion tracer.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Only create the stacktrace trace option when CONFIG_STACKTRACE is
configured.
Cleaned up the ftrace_trace_stack() function call a little to allow better
encapsulation of the stacktrace trace flag.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When the function tracer is not compiled in, do not create the option files
for it.
Fix up both the sched_wakeup and irqsoff tracers to handle the change.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Use a cute little macro trick to keep the names of the trace flags file
guaranteed to match the corresponding masks.
The macro TRACE_FLAGS is defined as a serious of enum names followed by
the string name of the file that matches it. For example:
#define TRACE_FLAGS \
C(PRINT_PARENT, "print-parent"), \
C(SYM_OFFSET, "sym-offset"), \
C(SYM_ADDR, "sym-addr"), \
C(VERBOSE, "verbose"),
Now we can define the following:
#undef C
#define C(a, b) TRACE_ITER_##a##_BIT
enum trace_iterator_bits { TRACE_FLAGS };
The above creates:
enum trace_iterator_bits {
TRACE_ITER_PRINT_PARENT_BIT,
TRACE_ITER_SYM_OFFSET_BIT,
TRACE_ITER_SYM_ADDR_BIT,
TRACE_ITER_VERBOSE_BIT,
};
Then we can redefine C as:
#undef C
#define C(a, b) TRACE_ITER_##a = (1 << TRACE_ITER_##a##_BIT)
enum trace_iterator_flags { TRACE_FLAGS };
Which creates:
enum trace_iterator_flags {
TRACE_ITER_PRINT_PARENT = (1 << TRACE_ITER_PRINT_PARENT_BIT),
TRACE_ITER_SYM_OFFSET = (1 << TRACE_ITER_SYM_OFFSET_BIT),
TRACE_ITER_SYM_ADDR = (1 << TRACE_ITER_SYM_ADDR_BIT),
TRACE_ITER_VERBOSE = (1 << TRACE_ITER_VERBOSE_BIT),
};
Then finally we can create the list of file names:
#undef C
#define C(a, b) b
static const char *trace_options[] = {
TRACE_FLAGS
NULL
};
Which creates:
static const char *trace_options[] = {
"print-parent",
"sym-offset",
"sym-addr",
"verbose",
NULL
};
The importance of this is that the strings match the bit index.
trace_options[TRACE_ITER_SYM_ADDR_BIT] == "sym-addr"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Using enums with FLAG_BIT and then defining a FLAG = (1 << FLAG_BIT), is a
bit more robust as we require that there are no bits out of order or skipped
to match the file names that represent the bits.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There was a time where the function tracing would disable interrupts unless
specifically told not to, where it would only disable preemption. With the
new lockless code, the function tracing never disalbes interrupts and just
uses disabling of preemption. Remove the option "ftrace_preempt" as it does
nothing anyway.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In order to facilitate making all tracer options visible even when the
tracer is not active, we need to get rid of duplicate options. Any option
that is shared between multiple tracers really should be a main option.
As the wakeup and irqsoff tracers both use the "display-graph" option, and
use it exactly the same way, move that option from the tracer options to the
main options and consolidate them.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
seq_print_user_ip() is used in only one location in one file. Turn it into a
static function. We could inject its code into the caller, but that would
make the code a bit too complex. Keep the code separate.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
seq_print_userip_objs() is used only in one location, in one file. Instead
of having it as an external function, go one further than making it static,
but inject is code into its only user. It doesn't make the calling function
much more complex.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In preparation for having trace options be per instance, the trace_array
needs to be passed to the trace_buffer_unlock_commit(). The
trace_event_buffer_lock_reserve() already passes in the trace_event_file
where the trace_array can be derived from.
Also added a "__init" to the boot up test event plus function tracing
function function_test_events_call().
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
ftrace_trace_stack_regs() is used in only one place, and because that is
such a simple function, just move its code into the location that it was
used in (trace_buffer_unlock_commit_regs()).
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch makes is_good_name return bool to improve readability
due to this particular function only using either one or zero as its
return value.
No functional change.
Link: http://lkml.kernel.org/r/1442929393-4753-2-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The changes with more meat are:
o Allowing the trace event filters to filter on CPU number and process ids
o Two new markers for trace output latency were added
(10 and 100 msec latencies)
o Have tracing_thresh filter function profiling time
I also worked on modifying the ring buffer code for some future
work, and moved the adding of the timestamp around. One of my changes
caused a regression, and since other changes were built on top of it
and already tested, I had to operate a revert of that change. Instead
of rebasing, this change set has the code that caused a regression
as well as the code to revert that change without touching the other
changes that were made on top of it.
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Merge tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing update from Steven Rostedt:
"Mostly this is just clean ups and micro optimizations.
The changes with more meat are:
- Allowing the trace event filters to filter on CPU number and
process ids
- Two new markers for trace output latency were added (10 and 100
msec latencies)
- Have tracing_thresh filter function profiling time
I also worked on modifying the ring buffer code for some future work,
and moved the adding of the timestamp around. One of my changes
caused a regression, and since other changes were built on top of it
and already tested, I had to operate a revert of that change. Instead
of rebasing, this change set has the code that caused a regression as
well as the code to revert that change without touching the other
changes that were made on top of it"
* tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ring-buffer: Revert "ring-buffer: Get timestamp after event is allocated"
tracing: Don't make assumptions about length of string on task rename
tracing: Allow triggers to filter for CPU ids and process names
ftrace: Format MCOUNT_ADDR address as type unsigned long
tracing: Introduce two additional marks for delay
ftrace: Fix function_graph duration spacing with 7-digits
ftrace: add tracing_thresh to function profile
tracing: Clean up stack tracing and fix fentry updates
ring-buffer: Reorganize function locations
ring-buffer: Make sure event has enough room for extend and padding
ring-buffer: Get timestamp after event is allocated
ring-buffer: Move the adding of the extended timestamp out of line
ring-buffer: Add event descriptor to simplify passing data
ftrace: correct the counter increment for trace_buffer data
tracing: Fix for non-continuous cpu ids
tracing: Prefer kcalloc over kzalloc with multiply
Pull networking updates from David Miller:
"Another merge window, another set of networking changes. I've heard
rumblings that the lightweight tunnels infrastructure has been voted
networking change of the year. But what do I know?
1) Add conntrack support to openvswitch, from Joe Stringer.
2) Initial support for VRF (Virtual Routing and Forwarding), which
allows the segmentation of routing paths without using multiple
devices. There are some semantic kinks to work out still, but
this is a reasonably strong foundation. From David Ahern.
3) Remove spinlock fro act_bpf fast path, from Alexei Starovoitov.
4) Ignore route nexthops with a link down state in ipv6, just like
ipv4. From Andy Gospodarek.
5) Remove spinlock from fast path of act_gact and act_mirred, from
Eric Dumazet.
6) Document the DSA layer, from Florian Fainelli.
7) Add netconsole support to bcmgenet, systemport, and DSA. Also
from Florian Fainelli.
8) Add Mellanox Switch Driver and core infrastructure, from Jiri
Pirko.
9) Add support for "light weight tunnels", which allow for
encapsulation and decapsulation without bearing the overhead of a
full blown netdevice. From Thomas Graf, Jiri Benc, and a cast of
others.
10) Add Identifier Locator Addressing support for ipv6, from Tom
Herbert.
11) Support fragmented SKBs in iwlwifi, from Johannes Berg.
12) Allow perf PMUs to be accessed from eBPF programs, from Kaixu Xia.
13) Add BQL support to 3c59x driver, from Loganaden Velvindron.
14) Stop using a zero TX queue length to mean that a device shouldn't
have a qdisc attached, use an explicit flag instead. From Phil
Sutter.
15) Use generic geneve netdevice infrastructure in openvswitch, from
Pravin B Shelar.
16) Add infrastructure to avoid re-forwarding a packet in software
that was already forwarded by a hardware switch. From Scott
Feldman.
17) Allow AF_PACKET fanout function to be implemented in a bpf
program, from Willem de Bruijn"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1458 commits)
netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled
net: fec: clear receive interrupts before processing a packet
ipv6: fix exthdrs offload registration in out_rt path
xen-netback: add support for multicast control
bgmac: Update fixed_phy_register()
sock, diag: fix panic in sock_diag_put_filterinfo
flow_dissector: Use 'const' where possible.
flow_dissector: Fix function argument ordering dependency
ixgbe: Resolve "initialized field overwritten" warnings
ixgbe: Remove bimodal SR-IOV disabling
ixgbe: Add support for reporting 2.5G link speed
ixgbe: fix bounds checking in ixgbe_setup_tc for 82598
ixgbe: support for ethtool set_rxfh
ixgbe: Avoid needless PHY access on copper phys
ixgbe: cleanup to use cached mask value
ixgbe: Remove second instance of lan_id variable
ixgbe: use kzalloc for allocating one thing
flow: Move __get_hash_from_flowi{4,6} into flow_dissector.c
ixgbe: Remove unused PCI bus types
...
The commit a4543a2fa9 "ring-buffer: Get timestamp after event is
allocated" is needed for some future work. But after adding it, there is a
race somewhere that causes the saved timestamp to have a slight shift, and
get ahead of the actual timestamp and make it look like time goes backwards.
I'm still looking into why this happens, but in the mean time, this is
holding up other work to get in. I'm reverting the change for now (which
makes the problem go away), and will add it back after I know what is wrong
and fix it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull core block updates from Jens Axboe:
"This first core part of the block IO changes contains:
- Cleanup of the bio IO error signaling from Christoph. We used to
rely on the uptodate bit and passing around of an error, now we
store the error in the bio itself.
- Improvement of the above from myself, by shrinking the bio size
down again to fit in two cachelines on x86-64.
- Revert of the max_hw_sectors cap removal from a revision again,
from Jeff Moyer. This caused performance regressions in various
tests. Reinstate the limit, bump it to a more reasonable size
instead.
- Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me.
Most devices have huge trim limits, which can cause nasty latencies
when deleting files. Enable the admin to configure the size down.
We will look into having a more sane default instead of UINT_MAX
sectors.
- Improvement of the SGP gaps logic from Keith Busch.
- Enable the block core to handle arbitrarily sized bios, which
enables a nice simplification of bio_add_page() (which is an IO hot
path). From Kent.
- Improvements to the partition io stats accounting, making it
faster. From Ming Lei.
- Also from Ming Lei, a basic fixup for overflow of the sysfs pending
file in blk-mq, as well as a fix for a blk-mq timeout race
condition.
- Ming Lin has been carrying Kents above mentioned patches forward
for a while, and testing them. Ming also did a few fixes around
that.
- Sasha Levin found and fixed a use-after-free problem introduced by
the bio->bi_error changes from Christoph.
- Small blk cgroup cleanup from Viresh Kumar"
* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
blk: Fix bio_io_vec index when checking bvec gaps
block: Replace SG_GAPS with new queue limits mask
block: bump BLK_DEF_MAX_SECTORS to 2560
Revert "block: remove artifical max_hw_sectors cap"
blk-mq: fix race between timeout and freeing request
blk-mq: fix buffer overflow when reading sysfs file of 'pending'
Documentation: update notes in biovecs about arbitrarily sized bios
block: remove bio_get_nr_vecs()
fs: use helper bio_add_page() instead of open coding on bi_io_vec
block: kill merge_bvec_fn() completely
md/raid5: get rid of bio_fits_rdev()
md/raid5: split bio for chunk_aligned_read
block: remove split code in blkdev_issue_{discard,write_same}
btrfs: remove bio splitting and merge_bvec_fn() calls
bcache: remove driver private bio splitting code
block: simplify bio_add_page()
block: make generic_make_request handle arbitrarily sized bios
blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
block: don't access bio->bi_error after bio_put()
block: shrink struct bio down to 2 cache lines again
...
Pull scheduler updates from Ingo Molnar:
"The biggest change in this cycle is the rewrite of the main SMP load
balancing metric: the CPU load/utilization. The main goal was to make
the metric more precise and more representative - see the changelog of
this commit for the gory details:
9d89c257df ("sched/fair: Rewrite runnable load and utilization average tracking")
It is done in a way that significantly reduces complexity of the code:
5 files changed, 249 insertions(+), 494 deletions(-)
and the performance testing results are encouraging. Nevertheless we
need to keep an eye on potential regressions, since this potentially
affects every SMP workload in existence.
This work comes from Yuyang Du.
Other changes:
- SCHED_DL updates. (Andrea Parri)
- Simplify architecture callbacks by removing finish_arch_switch().
(Peter Zijlstra et al)
- cputime accounting: guarantee stime + utime == rtime. (Peter
Zijlstra)
- optimize idle CPU wakeups some more - inspired by Facebook server
loads. (Mike Galbraith)
- stop_machine fixes and updates. (Oleg Nesterov)
- Introduce the 'trace_sched_waking' tracepoint. (Peter Zijlstra)
- sched/numa tweaks. (Srikar Dronamraju)
- misc fixes and small cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
sched/deadline: Fix comment in enqueue_task_dl()
sched/deadline: Fix comment in push_dl_tasks()
sched: Change the sched_class::set_cpus_allowed() calling context
sched: Make sched_class::set_cpus_allowed() unconditional
sched: Fix a race between __kthread_bind() and sched_setaffinity()
sched: Ensure a task has a non-normalized vruntime when returning back to CFS
sched/numa: Fix NUMA_DIRECT topology identification
tile: Reorganize _switch_to()
sched, sparc32: Update scheduler comments in copy_thread()
sched: Remove finish_arch_switch()
sched, tile: Remove finish_arch_switch
sched, sh: Fold finish_arch_switch() into switch_to()
sched, score: Remove finish_arch_switch()
sched, avr32: Remove finish_arch_switch()
sched, MIPS: Get rid of finish_arch_switch()
sched, arm: Remove finish_arch_switch()
sched/fair: Clean up load average references
sched/fair: Provide runnable_load_avg back to cfs_rq
sched/fair: Remove task and group entity load when they are dead
sched/fair: Init cfs_rq's sched_entity load average
...
generalize FETCH_FUNC_NAME(memory, string) into
strncpy_from_unsafe() and fix sparse warnings that were
present in original implementation.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
By extending the filter rules by more generic fields
we can write triggers filters like
echo 'stacktrace if cpu == 1' > \
/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
or
echo 'stacktrace if comm == sshd' > \
/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
CPU and COMM are not part of struct trace_entry. We could add the two
new fields to ftrace_common_field list and fix up all depending
sides. But that looks pretty ugly. Another thing I would like to
avoid that the 'format' file contents changes.
All this can be avoided by introducing another list which contains
non field members of struct trace_entry.
Link: http://lkml.kernel.org/r/1439210146-24707-1-git-send-email-daniel.wagner@bmw-carit.de
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
According to the perf_event_map_fd and index, the function
bpf_perf_event_read() can convert the corresponding map
value to the pointer to struct perf_event and return the
Hardware PMU counter value.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
By copying BPF related operation to uprobe processing path, this patch
allow users attach BPF programs to uprobes like what they are already
doing on kprobes.
After this patch, users are allowed to use PERF_EVENT_IOC_SET_BPF on a
uprobe perf event. Which make it possible to profile user space programs
and kernel events together using BPF.
Because of this patch, CONFIG_BPF_EVENTS should be selected by
CONFIG_UPROBE_EVENT to ensure trace_call_bpf() is compiled even if
KPROBE_EVENT is not set.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Mathieu reported that since 317f394160 ("sched: Move the second half
of ttwu() to the remote cpu") trace_sched_wakeup() can happen out of
context of the waker.
This is a problem when you want to analyse wakeup paths because it is
now very hard to correlate the wakeup event to whoever issued the
wakeup.
OTOH trace_sched_wakeup() is issued at the point where we set
p->state = TASK_RUNNING, which is right were we hand the task off to
the scheduler, so this is an important point when looking at
scheduling behaviour, up to here its been the wakeup path everything
hereafter is due to scheduler policy.
To bridge this gap, introduce a second tracepoint: trace_sched_waking.
It is guaranteed to be called in the waker context.
Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Francis Giraldeau <francis.giraldeau@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150609091336.GQ3644@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently we have two different ways to signal an I/O error on a BIO:
(1) by clearing the BIO_UPTODATE flag
(2) by returning a Linux errno value to the bi_end_io callback
The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario. Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.
So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Commit 4104d326b6 ("ftrace: Remove global function list and call function
directly") simplified the ftrace code by removing the global_ops list with a
new design. But this cleanup also broke the filtering of PIDs that are added
to the set_ftrace_pid file.
Add back the proper hooks to have pid filtering working once again.
Cc: stable@vger.kernel.org # 3.16+
Reported-by: Matt Fleming <matt@console-pimps.org>
Reported-by: Richard Weinberger <richard.weinberger@gmail.com>
Tested-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A fine granulity support for delay would be very useful when profiling
VM logics, such as page allocation including page reclaim and memory
compaction with function graph.
Thus, this patch adds two additional marks with two changes.
- An equal sign in mark selection function is removed to align code
behavior with comments and documentation.
- The function graph example related to delay in ftrace.txt is updated
to cover all supported marks.
Link: http://lkml.kernel.org/r/1436626300-1679-3-git-send-email-jungseoklee85@gmail.com
Cc: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Jungseok Lee noticed the following:
Currently, row's width of 7-digit duration numbers not aligned with
other cases like the following example.
3) $ 3999884 us | }
3) | finish_task_switch() {
3) 0.365 us | _raw_spin_unlock_irq();
3) 3.333 us | }
3) $ 3999976 us | }
3) $ 3999979 us | } /* schedule */
As adding a single white space in case of 7-digit numbers, the format
could be unified easily as follows.
3) $ 2237472 us | }
3) | finish_task_switch() {
3) 0.364 us | _raw_spin_unlock_irq();
3) 3.125 us | }
3) $ 2237556 us | }
3) $ 2237559 us | } /* schedule */
Instead of making a special case for 7-digit numbers, the logic
of the len and the space loop is slightly modified to make the
two cases have the same format.
Link: http://lkml.kernel.org/r/1436626300-1679-2-git-send-email-jungseoklee85@gmail.com
Reported-by: Jungseok Lee <jungseoklee85@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch extends tracing_thresh functionality to function profile tracer.
If tracing_thresh is set, print those entries only,
whose average is > tracing thresh.
Link: http://lkml.kernel.org/r/1434972488-8571-1-git-send-email-umesh.t@samsung.com
Signed-off-by: Umesh Tiwari <umesh.t@samsung.com>
[ Removed unnecessary 'moved' comment ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Akashi Takahiro was porting the stack tracer to arm64 and found some
issues with it. One was that it repeats the top function, due to the
stack frame added by the mcount caller and added by itself. This
was added when fentry came in, and before fentry created its own stack
frame. But x86's fentry now creates its own stack frame, and there's
no need to insert the function again.
This also cleans up the code a bit, where it doesn't need to do something
special for fentry, and doesn't include insertion of a duplicate
entry for the called function being traced.
Link: http://lkml.kernel.org/r/55A646EE.6030402@linaro.org
Some-suggestions-by: Jungseok Lee <jungseoklee85@gmail.com>
Some-suggestions-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Functions in ring-buffer.c have gotten interleaved between different
use cases. Move the functions around to get like functions closer
together. This may or may not help gcc keep cache locality, but it
makes it a little easier to work with the code.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Now that events only add time extends after it is committed, in case
an event comes in before it can discard the allocated event, the time
extend needs to be stored within the event. If the event is bigger
than then size needed for the time extend, padding must be added.
The minimum padding size is 8 bytes. Thus if the event is 12 bytes
(size of time extend + 4), there will not be enough room to add both
the time extend and padding. Make sure all events are either 8 bytes
or 16 or more bytes.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Move the capturing of the timestamp to after an event is allocated.
If the event is not a commit (where it is an event that preempted
another event), then no timestamp is needed, because the delta of
nested events is always zero.
If the event starts on a new page, no delta needs to be calculated
as the full timestamp will be added to the page header, and the
event will have a delta of zero.
Now if the event requires a time extend (the delta does not fit
in the 27 bit delta slot in the header), then the event is discarded,
the length is extended to hold the TIME_EXTEND event that allows for
a 59 bit delta, and the commit is tried again.
If the event can't be discarded (another event came in after it),
then the TIME_EXTEND is added directly to the allocated event and
the rest of the event is given padding.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Requiring a extended time stamp is an uncommon occurrence, and it is
best to do it out of line when needed.
Add a noinline function that handles the extended timestamp and
have it called with an unlikely to completely move it out of the
fast path.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add rb_event_info descriptor to pass event info to functions a bit
easier than using a bunch of parameters. This will also allow for
changing the code around a bit to find better fast paths.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In ftrace_dump, for disabling buffer, iter.tr->trace_buffer.data is used.
But for enabling, iter.trace_buffer->data is used.
Even though, both point to same buffer, for readability, same convention
should be used.
Link: http://lkml.kernel.org/r/1434972306-20043-1-git-send-email-umesh.t@samsung.com
Signed-off-by: Umesh Tiwari <umesh.t@samsung.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently exception occures due to access beyond buffer_iter
range while using index of cpu bigger than num_possible_cpus().
Below there is an example for such exception when we use
cpus 0,1,16,17.
In order to fix buffer allocation size for non-continuous cpu ids
we allocate according to the max cpu id and not according to the
amount of possible cpus.
Example:
$ cat /sys/kernel/debug/tracing/per_cpu/cpu1/trace
Path: /bin/busybox
CPU: 0 PID: 82 Comm: cat Not tainted 4.0.0 #29
task: 80734c80 ti: 80012000 task.ti: 80012000
[ECR ]: 0x00220100 => Invalid Read @ 0x00000000 by insn @ 0x800abafc
[EFA ]: 0x00000000
[BLINK ]: ring_buffer_read_finish+0x24/0x64
[ERET ]: rb_check_pages+0x20/0x188
[STAT32]: 0x00001a00 :
BTA: 0x800abafc SP: 0x80013f0c FP: 0x57719cf8
LPS: 0x200036b4 LPE: 0x200036b8 LPC: 0x00000000
r00: 0x8002aca0 r01: 0x00001606 r02: 0x00000000
r03: 0x00000001 r04: 0x00000000 r05: 0x804b4954
r06: 0x00030003 r07: 0x8002a260 r08: 0x00000286
r09: 0x00080002 r10: 0x00001006 r11: 0x807351a4
r12: 0x00000001
Stack Trace:
rb_check_pages+0x20/0x188
ring_buffer_read_finish+0x24/0x64
tracing_release+0x4e/0x170
__fput+0x62/0x158
task_work_run+0xa2/0xd4
do_notify_resume+0x52/0x7c
resume_user_mode_begin+0xdc/0xe0
Link: http://lkml.kernel.org/r/1433835155-6894-3-git-send-email-gilf@ezchip.com
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Gil Fruchter <gilf@ezchip.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Use kcalloc for allocating an array instead of kzalloc with multiply,
as that is what kcalloc is used for.
Found with checkpatch.
Link: http://lkml.kernel.org/r/1433835155-6894-2-git-send-email-gilf@ezchip.com
Signed-off-by: Gil Fruchter <gilf@ezchip.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Fengguang Wu's tests triggered a bug in the branch tracer's start up
test when CONFIG_DEBUG_PREEMPT set. This was because that config
adds some debug logic in the per cpu field, which calls back into
the branch tracer.
The branch tracer has its own recursive checks, but uses a per cpu
variable to implement it. If retrieving the per cpu variable calls
back into the branch tracer, you can see how things will break.
Instead of using a per cpu variable, use the trace_recursion field
of the current task struct. Simply set a bit when entering the
branch tracing and clear it when leaving. If the bit is set on
entry, just don't do the tracing.
There's also the case with lockdep, as the local_irq_save() called
before the recursion can also trigger code that can call back into
the function. Changing that to a raw_local_irq_save() will protect
that as well.
This prevents the recursion and the inevitable crash that follows.
Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.com
Cc: stable@vger.kernel.org # 3.10+
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
"monitonic raw". Also some enhancements to make the ring buffer even
faster. But the biggest and most noticeable change is the renaming of
the ftrace* files, structures and variables that have to deal with
trace events.
Over the years I've had several developers tell me about their confusion
with what ftrace is compared to events. Technically, "ftrace" is the
infrastructure to do the function hooks, which include tracing and also
helps with live kernel patching. But the trace events are a separate
entity altogether, and the files that affect the trace events should
not be named "ftrace". These include:
include/trace/ftrace.h -> include/trace/trace_events.h
include/linux/ftrace_event.h -> include/linux/trace_events.h
Also, functions that are specific for trace events have also been renamed:
ftrace_print_*() -> trace_print_*()
(un)register_ftrace_event() -> (un)register_trace_event()
ftrace_event_name() -> trace_event_name()
ftrace_trigger_soft_disabled()-> trace_trigger_soft_disabled()
ftrace_define_fields_##call() -> trace_define_fields_##call()
ftrace_get_offsets_##call() -> trace_get_offsets_##call()
Structures have been renamed:
ftrace_event_file -> trace_event_file
ftrace_event_{call,class} -> trace_event_{call,class}
ftrace_event_buffer -> trace_event_buffer
ftrace_subsystem_dir -> trace_subsystem_dir
ftrace_event_raw_##call -> trace_event_raw_##call
ftrace_event_data_offset_##call-> trace_event_data_offset_##call
ftrace_event_type_funcs_##call -> trace_event_type_funcs_##call
And a few various variables and flags have also been updated.
This has been sitting in linux-next for some time, and I have not heard
a single complaint about this rename breaking anything. Mostly because
these functions, variables and structures are mostly internal to the
tracing system and are seldom (if ever) used by anything external to that.
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Merge tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This patch series contains several clean ups and even a new trace
clock "monitonic raw". Also some enhancements to make the ring buffer
even faster. But the biggest and most noticeable change is the
renaming of the ftrace* files, structures and variables that have to
deal with trace events.
Over the years I've had several developers tell me about their
confusion with what ftrace is compared to events. Technically,
"ftrace" is the infrastructure to do the function hooks, which include
tracing and also helps with live kernel patching. But the trace
events are a separate entity altogether, and the files that affect the
trace events should not be named "ftrace". These include:
include/trace/ftrace.h -> include/trace/trace_events.h
include/linux/ftrace_event.h -> include/linux/trace_events.h
Also, functions that are specific for trace events have also been renamed:
ftrace_print_*() -> trace_print_*()
(un)register_ftrace_event() -> (un)register_trace_event()
ftrace_event_name() -> trace_event_name()
ftrace_trigger_soft_disabled() -> trace_trigger_soft_disabled()
ftrace_define_fields_##call() -> trace_define_fields_##call()
ftrace_get_offsets_##call() -> trace_get_offsets_##call()
Structures have been renamed:
ftrace_event_file -> trace_event_file
ftrace_event_{call,class} -> trace_event_{call,class}
ftrace_event_buffer -> trace_event_buffer
ftrace_subsystem_dir -> trace_subsystem_dir
ftrace_event_raw_##call -> trace_event_raw_##call
ftrace_event_data_offset_##call-> trace_event_data_offset_##call
ftrace_event_type_funcs_##call -> trace_event_type_funcs_##call
And a few various variables and flags have also been updated.
This has been sitting in linux-next for some time, and I have not
heard a single complaint about this rename breaking anything. Mostly
because these functions, variables and structures are mostly internal
to the tracing system and are seldom (if ever) used by anything
external to that"
* tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
ring_buffer: Allow to exit the ring buffer benchmark immediately
ring-buffer-benchmark: Fix the wrong type
ring-buffer-benchmark: Fix the wrong param in module_param
ring-buffer: Add enum names for the context levels
ring-buffer: Remove useless unused tracing_off_permanent()
ring-buffer: Give NMIs a chance to lock the reader_lock
ring-buffer: Add trace_recursive checks to ring_buffer_write()
ring-buffer: Allways do the trace_recursive checks
ring-buffer: Move recursive check to per_cpu descriptor
ring-buffer: Add unlikelys to make fast path the default
tracing: Rename ftrace_get_offsets_##call() to trace_event_get_offsets_##call()
tracing: Rename ftrace_define_fields_##call() to trace_event_define_fields_##call()
tracing: Rename ftrace_event_type_funcs_##call to trace_event_type_funcs_##call
tracing: Rename ftrace_data_offset_##call to trace_event_data_offset_##call
tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##call
tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled()
tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_*
tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dir
tracing: Rename ftrace_event_name() to trace_event_name()
tracing: Rename FTRACE_MAX_EVENT to TRACE_EVENT_TYPE_MAX
...
I could not come up with a situation where the operand counter (cnt)
could go below zero, so I added a WARN_ON_ONCE(cnt < 0). Vince was
able to trigger that warn on with his fuzzer test, but didn't have
a filter input that caused it.
Later, Sasha Levin was able to trigger that same warning, and was
able to give me the filter string that triggered it. It was simply
a single operation ">".
I wrapped the filtering code in a userspace program such that I could
single step through the logic. With a single operator the operand
counter can legitimately go below zero, and should be reported to the
user as an error, but should not produce a kernel warning. The
WARN_ON_ONCE(cnt < 0) should be just a "if (cnt < 0) break;" and the
code following it will produce the error message for the user.
While debugging this, I found that there was another bug that let
the pointer to the filter string go beyond the filter string.
This too was fixed.
Finally, there was a typo in a stub function that only gets compiled
if trace events is disabled but tracing is enabled (I'm not even sure
that's possible).
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Merge tag 'trace-fixes-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This isn't my 4.2 pull request (yet). I found a few more bugs that I
would have sent to fix 4.1, but since 4.1 is already out, I'm sending
this before sending my 4.2 request (which is ready to go).
After fixing the previous filter issue reported by Vince Weaver, I
could not come up with a situation where the operand counter (cnt)
could go below zero, so I added a WARN_ON_ONCE(cnt < 0). Vince was
able to trigger that warn on with his fuzzer test, but didn't have a
filter input that caused it.
Later, Sasha Levin was able to trigger that same warning, and was able
to give me the filter string that triggered it. It was simply a
single operation ">".
I wrapped the filtering code in a userspace program such that I could
single step through the logic. With a single operator the operand
counter can legitimately go below zero, and should be reported to the
user as an error, but should not produce a kernel warning. The
WARN_ON_ONCE(cnt < 0) should be just a "if (cnt < 0) break;" and the
code following it will produce the error message for the user.
While debugging this, I found that there was another bug that let the
pointer to the filter string go beyond the filter string. This too
was fixed.
Finally, there was a typo in a stub function that only gets compiled
if trace events is disabled but tracing is enabled (I'm not even sure
that's possible)"
* tag 'trace-fixes-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix typo from "static inlin" to "static inline"
tracing/filter: Do not allow infix to exceed end of string
tracing/filter: Do not WARN on operand count going below zero
Part of the disassembly of do_blk_trace_setup:
231b: e8 00 00 00 00 callq 2320 <do_blk_trace_setup+0x50>
231c: R_X86_64_PC32 strlen+0xfffffffffffffffc
2320: eb 0a jmp 232c <do_blk_trace_setup+0x5c>
2322: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
2328: 48 83 c3 01 add $0x1,%rbx
232c: 48 39 d8 cmp %rbx,%rax
232f: 76 47 jbe 2378 <do_blk_trace_setup+0xa8>
2331: 41 80 3c 1c 2f cmpb $0x2f,(%r12,%rbx,1)
2336: 75 f0 jne 2328 <do_blk_trace_setup+0x58>
2338: 41 c6 04 1c 5f movb $0x5f,(%r12,%rbx,1)
233d: 4c 89 e7 mov %r12,%rdi
2340: e8 00 00 00 00 callq 2345 <do_blk_trace_setup+0x75>
2341: R_X86_64_PC32 strlen+0xfffffffffffffffc
2345: eb e1 jmp 2328 <do_blk_trace_setup+0x58>
Yep, that's right: gcc isn't smart enough to realize that replacing '/' by
'_' cannot change the strlen(), so we call it again and again (at least
when a '/' is found). Even if gcc were that smart, this construction
would still loop over the string twice, once for the initial strlen() call
and then the open-coded loop.
Let's simply use strreplace() instead.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Liked-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's no point in starting over every time we see a ','...
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The trace.h header when called without CONFIG_EVENT_TRACING enabled
(seldom done), will not compile because of a typo in the protocol
of trace_event_enum_update().
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
While debugging a WARN_ON() for filtering, I found that it is possible
for the filter string to be referenced after its end. With the filter:
# echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter
The filter_parse() function can call infix_get_op() which calls
infix_advance() that updates the infix filter pointers for the cnt
and tail without checking if the filter is already at the end, which
will put the cnt to zero and the tail beyond the end. The loop then calls
infix_next() that has
ps->infix.cnt--;
return ps->infix.string[ps->infix.tail++];
The cnt will now be below zero, and the tail that is returned is
already passed the end of the filter string. So far the allocation
of the filter string usually has some buffer that is zeroed out, but
if the filter string is of the exact size of the allocated buffer
there's no guarantee that the charater after the nul terminating
character will be zero.
Luckily, only root can write to the filter.
Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When testing the fix for the trace filter, I could not come up with
a scenario where the operand count goes below zero, so I added a
WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case
that it can happen (although the filter would be wrong).
# echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter
That is, a single operation without any operands will hit the path
where the WARN_ON_ONCE() can trigger. Although this is harmless,
and the filter is reported as a error. But instead of spitting out
a warning to the kernel dmesg, just fail nicely and report it via
the proper channels.
Link: http://lkml.kernel.org/r/558C6082.90608@oracle.com
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull networking updates from David Miller:
1) Add TX fast path in mac80211, from Johannes Berg.
2) Add TSO/GRO support to ibmveth, from Thomas Falcon
3) Move away from cached routes in ipv6, just like ipv4, from Martin
KaFai Lau.
4) Lots of new rhashtable tests, from Thomas Graf.
5) Run ingress qdisc lockless, from Alexei Starovoitov.
6) Allow servers to fetch TCP packet headers for SYN packets of new
connections, for fingerprinting. From Eric Dumazet.
7) Add mode parameter to pktgen, for testing receive. From Alexei
Starovoitov.
8) Cache access optimizations via simplifications of build_skb(), from
Alexander Duyck.
9) Move page frag allocator under mm/, also from Alexander.
10) Add xmit_more support to hv_netvsc, from KY Srinivasan.
11) Add a counter guard in case we try to perform endless reclassify
loops in the packet scheduler.
12) Extern flow dissector to be programmable and use it in new "Flower"
classifier. From Jiri Pirko.
13) AF_PACKET fanout rollover fixes, performance improvements, and new
statistics. From Willem de Bruijn.
14) Add netdev driver for GENEVE tunnels, from John W Linville.
15) Add ingress netfilter hooks and filtering, from Pablo Neira Ayuso.
16) Fix handling of epoll edge triggers in TCP, from Eric Dumazet.
17) Add an ECN retry fallback for the initial TCP handshake, from Daniel
Borkmann.
18) Add tail call support to BPF, from Alexei Starovoitov.
19) Add several pktgen helper scripts, from Jesper Dangaard Brouer.
20) Add zerocopy support to AF_UNIX, from Hannes Frederic Sowa.
21) Favor even port numbers for allocation to connect() requests, and
odd port numbers for bind(0), in an effort to help avoid
ip_local_port_range exhaustion. From Eric Dumazet.
22) Add Cavium ThunderX driver, from Sunil Goutham.
23) Allow bpf programs to access skb_iif and dev->ifindex SKB metadata,
from Alexei Starovoitov.
24) Add support for T6 chips in cxgb4vf driver, from Hariprasad Shenai.
25) Double TCP Small Queues default to 256K to accomodate situations
like the XEN driver and wireless aggregation. From Wei Liu.
26) Add more entropy inputs to flow dissector, from Tom Herbert.
27) Add CDG congestion control algorithm to TCP, from Kenneth Klette
Jonassen.
28) Convert ipset over to RCU locking, from Jozsef Kadlecsik.
29) Track and act upon link status of ipv4 route nexthops, from Andy
Gospodarek.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1670 commits)
bridge: vlan: flush the dynamically learned entries on port vlan delete
bridge: multicast: add a comment to br_port_state_selection about blocking state
net: inet_diag: export IPV6_V6ONLY sockopt
stmmac: troubleshoot unexpected bits in des0 & des1
net: ipv4 sysctl option to ignore routes when nexthop link is down
net: track link-status of ipv4 nexthops
net: switchdev: ignore unsupported bridge flags
net: Cavium: Fix MAC address setting in shutdown state
drivers: net: xgene: fix for ACPI support without ACPI
ip: report the original address of ICMP messages
net/mlx5e: Prefetch skb data on RX
net/mlx5e: Pop cq outside mlx5e_get_cqe
net/mlx5e: Remove mlx5e_cq.sqrq back-pointer
net/mlx5e: Remove extra spaces
net/mlx5e: Avoid TX CQE generation if more xmit packets expected
net/mlx5e: Avoid redundant dev_kfree_skb() upon NOP completion
net/mlx5e: Remove re-assignment of wq type in mlx5e_enable_rq()
net/mlx5e: Use skb_shinfo(skb)->gso_segs rather than counting them
net/mlx5e: Static mapping of netdev priv resources to/from netdev TX queues
net/mlx4_en: Use HW counters for rx/tx bytes/packets in PF device
...
When the following filter is used it causes a warning to trigger:
# cd /sys/kernel/debug/tracing
# echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter
-bash: echo: write error: Invalid argument
# cat events/ext4/ext4_truncate_exit/filter
((dev==1)blocks==2)
^
parse_error: No error
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1223 at kernel/trace/trace_events_filter.c:1640 replace_preds+0x3c5/0x990()
Modules linked in: bnep lockd grace bluetooth ...
CPU: 3 PID: 1223 Comm: bash Tainted: G W 4.1.0-rc3-test+ #450
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
0000000000000668 ffff8800c106bc98 ffffffff816ed4f9 ffff88011ead0cf0
0000000000000000 ffff8800c106bcd8 ffffffff8107fb07 ffffffff8136b46c
ffff8800c7d81d48 ffff8800d4c2bc00 ffff8800d4d4f920 00000000ffffffea
Call Trace:
[<ffffffff816ed4f9>] dump_stack+0x4c/0x6e
[<ffffffff8107fb07>] warn_slowpath_common+0x97/0xe0
[<ffffffff8136b46c>] ? _kstrtoull+0x2c/0x80
[<ffffffff8107fb6a>] warn_slowpath_null+0x1a/0x20
[<ffffffff81159065>] replace_preds+0x3c5/0x990
[<ffffffff811596b2>] create_filter+0x82/0xb0
[<ffffffff81159944>] apply_event_filter+0xd4/0x180
[<ffffffff81152bbf>] event_filter_write+0x8f/0x120
[<ffffffff811db2a8>] __vfs_write+0x28/0xe0
[<ffffffff811dda43>] ? __sb_start_write+0x53/0xf0
[<ffffffff812e51e0>] ? security_file_permission+0x30/0xc0
[<ffffffff811dc408>] vfs_write+0xb8/0x1b0
[<ffffffff811dc72f>] SyS_write+0x4f/0xb0
[<ffffffff816f5217>] system_call_fastpath+0x12/0x6a
---[ end trace e11028bd95818dcd ]---
Worse yet, reading the error message (the filter again) it says that
there was no error, when there clearly was. The issue is that the
code that checks the input does not check for balanced ops. That is,
having an op between a closed parenthesis and the next token.
This would only cause a warning, and fail out before doing any real
harm, but it should still not caues a warning, and the error reported
should work:
# cd /sys/kernel/debug/tracing
# echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter
-bash: echo: write error: Invalid argument
# cat events/ext4/ext4_truncate_exit/filter
((dev==1)blocks==2)
^
parse_error: Meaningless filter expression
And give no kernel warning.
Link: http://lkml.kernel.org/r/20150615175025.7e809215@gandalf.local.home
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: stable@vger.kernel.org # 2.6.31+
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It's useful to do per-cpu histograms.
Suggested-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf_trace_printk() is a helper function used to debug eBPF programs.
Let socket and TC programs use it as well.
Note, it's DEBUG ONLY helper. If it's used in the program,
the kernel will print warning banner to make sure users don't use
it in production.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
eBPF programs attached to kprobes need to filter based on
current->pid, uid and other fields, so introduce helper functions:
u64 bpf_get_current_pid_tgid(void)
Return: current->tgid << 32 | current->pid
u64 bpf_get_current_uid_gid(void)
Return: current_gid << 32 | current_uid
bpf_get_current_comm(char *buf, int size_of_buf)
stores current->comm into buf
They can be used from the programs attached to TC as well to classify packets
based on current task fields.
Update tracex2 example to print histogram of write syscalls for each process
instead of aggregated for all.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It takes a while until the ring_buffer_benchmark module is removed
when the ring buffer hammer is running. It is because it takes
few seconds and kthread_should_stop() is not being checked.
This patch adds the check for kthread termination into the producer.
It uses the existing @kill_test flag to finish the kthreads as
cleanly as possible.
It disables printing the "ERROR" message when the kthread is going.
It makes sure that producer does not go into the 10sec sleep
when it is being killed.
Finally, it does not call wait_to_die() when kthread_should_stop()
already returns true.
Link: http://lkml.kernel.org/r/20150615155428.GD3135@pathway.suse.cz
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The macro 'module_param' shows that the type of the
variable disable_reader and write_iteration is unsigned
integer. so, we change their type form int to unsigned int.
Link: http://lkml.kernel.org/r/1433923927-67782-1-git-send-email-long.wanglong@huawei.com
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The {producer|consumer}_{nice|fifo} parameters are integer
type, we should use 'int' as the second param in module_param.
For example(consumer_fifo):
the default value of consumer_fifo is -1.
Without this patch:
# cat /sys/module/ring_buffer_benchmark/parameters/consumer_fifo
4294967295
With this patch:
# cat /sys/module/ring_buffer_benchmark/parameters/consumer_fifo
-1
Link: http://lkml.kernel.org/r/1433923873-67712-1-git-send-email-long.wanglong@huawei.com
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As this is already exported from tracing side via commit d9847d310a
("tracing: Allow BPF programs to call bpf_ktime_get_ns()"), we might
as well want to move it to the core, so also networking users can make
use of it, e.g. to measure diffs for certain flows from ingress/egress.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The tracing_off_permanent() call is a way to disable all ring_buffers.
Nothing uses it and nothing should use it, as tracing_off() and
friends are better, as they disable the ring buffers related to
tracing. The tracing_off_permanent() even disabled non tracing
ring buffers. This is a bit drastic, and was added to handle NMIs
doing outputs that could corrupt the ring buffer when only tracing
used them. It is now obsolete and adds a little overhead, it should
be removed.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently, if an NMI does a dump of a ring buffer, it disables
all ring buffers from ever doing any writes again. This is because
it wont take the locks for the cpu_buffer and this can cause
corruption if it preempted a read, or a read happens on another
CPU for the current cpu buffer. This is a bit overkill.
First, it should at least try to take the lock, and if it fails
then disable it. Also, there's no need to disable all ring
buffers, even those that are unrelated to what is being read.
Only disable the per cpu ring buffer that is being read if
it can not get the lock for it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ring_buffer_write() function isn't protected by the trace recursive
writes. Luckily, this function is not used as much and is unlikely
to ever recurse. But it should still have the protection, because
even a call to ring_buffer_lock_reserve() could cause ring buffer
corruption if called when ring_buffer_write() is being used.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently the trace_recursive checks are only done if CONFIG_TRACING
is enabled. That was because there use to be a dependency with tracing
for the recursive checks (it used the task_struct trace recursive
variable). But now it uses its own variable and there is no dependency.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Instead of using a global per_cpu variable to perform the recursive
checks into the ring buffer, use the already existing per_cpu descriptor
that is part of the ring buffer itself.
Not only does this simplify the code, it also allows for one ring buffer
to be used within the guts of the use of another ring buffer. For example
trace_printk() can now be used within the ring buffer to record changes
done by an instance into the main ring buffer. The recursion checks
will prevent the trace_printk() itself from causing recursive issues
with the main ring buffer (it is just ignored), but the recursive
checks wont prevent the trace_printk() from recording other ring buffers.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
introduce bpf_tail_call(ctx, &jmp_table, index) helper function
which can be used from BPF programs like:
int bpf_prog(struct pt_regs *ctx)
{
...
bpf_tail_call(ctx, &jmp_table, index);
...
}
that is roughly equivalent to:
int bpf_prog(struct pt_regs *ctx)
{
...
if (jmp_table[index])
return (*jmp_table[index])(ctx);
...
}
The important detail that it's not a normal call, but a tail call.
The kernel stack is precious, so this helper reuses the current
stack frame and jumps into another BPF program without adding
extra call frame.
It's trivially done in interpreter and a bit trickier in JITs.
In case of x64 JIT the bigger part of generated assembler prologue
is common for all programs, so it is simply skipped while jumping.
Other JITs can do similar prologue-skipping optimization or
do stack unwind before jumping into the next program.
bpf_tail_call() arguments:
ctx - context pointer
jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table
index - index in the jump table
Since all BPF programs are idenitified by file descriptor, user space
need to populate the jmp_table with FDs of other BPF programs.
If jmp_table[index] is empty the bpf_tail_call() doesn't jump anywhere
and program execution continues as normal.
New BPF_MAP_TYPE_PROG_ARRAY map type is introduced so that user space can
populate this jmp_table array with FDs of other bpf programs.
Programs can share the same jmp_table array or use multiple jmp_tables.
The chain of tail calls can form unpredictable dynamic loops therefore
tail_call_cnt is used to limit the number of calls and currently is set to 32.
Use cases:
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
==========
- simplify complex programs by splitting them into a sequence of small programs
- dispatch routine
For tracing and future seccomp the program may be triggered on all system
calls, but processing of syscall arguments will be different. It's more
efficient to implement them as:
int syscall_entry(struct seccomp_data *ctx)
{
bpf_tail_call(ctx, &syscall_jmp_table, ctx->nr /* syscall number */);
... default: process unknown syscall ...
}
int sys_write_event(struct seccomp_data *ctx) {...}
int sys_read_event(struct seccomp_data *ctx) {...}
syscall_jmp_table[__NR_write] = sys_write_event;
syscall_jmp_table[__NR_read] = sys_read_event;
For networking the program may call into different parsers depending on
packet format, like:
int packet_parser(struct __sk_buff *skb)
{
... parse L2, L3 here ...
__u8 ipproto = load_byte(skb, ... offsetof(struct iphdr, protocol));
bpf_tail_call(skb, &ipproto_jmp_table, ipproto);
... default: process unknown protocol ...
}
int parse_tcp(struct __sk_buff *skb) {...}
int parse_udp(struct __sk_buff *skb) {...}
ipproto_jmp_table[IPPROTO_TCP] = parse_tcp;
ipproto_jmp_table[IPPROTO_UDP] = parse_udp;
- for TC use case, bpf_tail_call() allows to implement reclassify-like logic
- bpf_map_update_elem/delete calls into BPF_MAP_TYPE_PROG_ARRAY jump table
are atomic, so user space can build chains of BPF programs on the fly
Implementation details:
=======================
- high performance of bpf_tail_call() is the goal.
It could have been implemented without JIT changes as a wrapper on top of
BPF_PROG_RUN() macro, but with two downsides:
. all programs would have to pay performance penalty for this feature and
tail call itself would be slower, since mandatory stack unwind, return,
stack allocate would be done for every tailcall.
. tailcall would be limited to programs running preempt_disabled, since
generic 'void *ctx' doesn't have room for 'tail_call_cnt' and it would
need to be either global per_cpu variable accessed by helper and by wrapper
or global variable protected by locks.
In this implementation x64 JIT bypasses stack unwind and jumps into the
callee program after prologue.
- bpf_prog_array_compatible() ensures that prog_type of callee and caller
are the same and JITed/non-JITed flag is the same, since calling JITed
program from non-JITed is invalid, since stack frames are different.
Similarly calling kprobe type program from socket type program is invalid.
- jump table is implemented as BPF_MAP_TYPE_PROG_ARRAY to reuse 'map'
abstraction, its user space API and all of verifier logic.
It's in the existing arraymap.c file, since several functions are
shared with regular array map.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_raw_##call structures are built
by macros for trace events. They have nothing to do with function tracing.
Rename them.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_trigger_soft_disabled() tests if a
trace_event is soft disabled (called but not traced), and returns true if
it is. It has nothing to do with function tracing and should be renamed.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The FTRACE_EVENT_FL_* flags are flags to
do with the trace_event files in the tracefs directory. They are not related
to function tracing. Rename them to a more descriptive name.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structure ftrace_subsystem_dir holds
the information about trace event subsystems. It should not be named
ftrace, rename it to trace_subsystem_dir.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. ftrace_event_name() returns the name of
an event tracepoint, has nothing to do with function tracing. Rename it
to trace_event_name().
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. Rename the max trace_event type size to
something more descriptive and appropriate.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_output_*() and ftrace_raw_output_*()
functions represent the trace_event code. Rename them to just trace_output
or trace_raw_output.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The ftrace_event_buffer functions and data
structures are for trace_events and not for function hooks. Rename them
to trace_event_buffer*.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structures ftrace_event_call and
ftrace_event_class have nothing to do with the function hooks, and are
really trace_event structures. Rename ftrace_event_* to trace_event_*.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The structure ftrace_event_file is really
about trace events and not "ftrace". Rename it to trace_event_file.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The functions (un)register_ftrace_event() is
really about trace_events, and the name should be register_trace_event()
instead.
Also renamed ftrace_event_reg() to trace_event_reg() for the same reason.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The name "ftrace" really refers to the function hook infrastructure. It
is not about the trace_events. The functions ftrace_print_*() are not part of
the function infrastructure, and the names can be confusing. Rename them
to be trace_print_*().
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The term "ftrace" is really the infrastructure of the function hooks,
and not the trace events. Rename ftrace_event.h to trace_events.h to
represent the trace_event infrastructure and decouple the term ftrace
from it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Expose the NMI safe accessor to the monotonic raw clock to the
tracer. The mono clock was added with commit
1b3e5c0936. The advantage of the
monotonic raw clock is that it will advance more constantly than the
monotonic clock.
Imagine someone is trying to optimize a particular program to reduce
instructions executed for a given workload while minimizing the effect
on runtime. Also suppose that NTP is running and potentially making
larger adjustments to the monotonic clock. If NTP is adjusting the
monotonic clock to advance more rapidly, the program will appear to
use fewer instructions per second but run longer than if the monotonic
raw clock had been used. The total number of instructions observed
would be the same regardless of the clock source used, but how it's
attributed to time would be affected.
Conversely if NTP is adjusting the monotonic clock to advance more
slowly, the program will appear to use more instructions per second
but run more quickly. Of course there are many sources that can cause
jitter in performance measurements on modern processors, but let's
remove NTP from the list.
The monotonic raw clock can also be useful for tracing early boot,
e.g. when debugging issues with NTP.
Link: http://lkml.kernel.org/r/20150508143037.GB1276@dreric01-Precision-T1650
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Drew Richardson <drew.richardson@arm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Critical tracepoint hooks should never call anything that takes a lock,
so they are unable to call getrawmonotonic() or ktime_get().
Export the rest of the tracing clock functions so can be used in
tracepoint hooks.
Background: We have a customer that adds their own module and registers
a tracepoint hook to sched_wakeup. They were using ktime_get() for a
time source, but it grabs a seq lock and caused a deadlock to occur.
Link: http://lkml.kernel.org/r/1430406624-22609-1-git-send-email-jsnitsel@redhat.com
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The only caller to this function (__print_array) was getting it wrong by
passing the array length instead of buffer length. As the element size
was already being passed for other reasons it seems reasonable to push
the calculation of buffer length into the function.
Link: http://lkml.kernel.org/r/1430320727-14582-1-git-send-email-alex.bennee@linaro.org
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull fourth vfs update from Al Viro:
"d_inode() annotations from David Howells (sat in for-next since before
the beginning of merge window) + four assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
RCU pathwalk breakage when running into a symlink overmounting something
fix I_DIO_WAKEUP definition
direct-io: only inc/dec inode->i_dio_count for file systems
fs/9p: fix readdir()
VFS: assorted d_backing_inode() annotations
VFS: fs/inode.c helpers: d_inode() annotations
VFS: fs/cachefiles: d_backing_inode() annotations
VFS: fs library helpers: d_inode() annotations
VFS: assorted weird filesystems: d_inode() annotations
VFS: normal filesystems (and lustre): d_inode() annotations
VFS: security/: d_inode() annotations
VFS: security/: d_backing_inode() annotations
VFS: net/: d_inode() annotations
VFS: net/unix: d_backing_inode() annotations
VFS: kernel/: d_inode() annotations
VFS: audit: d_backing_inode() annotations
VFS: Fix up some ->d_inode accesses in the chelsio driver
VFS: Cachefiles should perform fs modifications on the top layer only
VFS: AF_UNIX sockets should call mknod on the top layer only
The first is a bug when ftrace_dump_on_oops is triggered in atomic context
and function graph tracer is the tracer that is being reported.
The second fix is bad parsing of the trace_events from the kernel
command line, where it would ignore specific events if the system
name is used with defining the event(it enables all events within the
system).
The last one is a fix to the TRACE_DEFINE_ENUM(), where a check was missing
to see if the ptr was incremented to the end of the string, but the loop
increments it again and can miss the nul delimiter to stop processing.
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Merge tag 'trace-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This adds three fixes for the tracing code.
The first is a bug when ftrace_dump_on_oops is triggered in atomic
context and function graph tracer is the tracer that is being
reported.
The second fix is bad parsing of the trace_events from the kernel
command line, where it would ignore specific events if the system name
is used with defining the event(it enables all events within the
system).
The last one is a fix to the TRACE_DEFINE_ENUM(), where a check was
missing to see if the ptr was incremented to the end of the string,
but the loop increments it again and can miss the nul delimiter to
stop processing"
* tag 'trace-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix possible out of bounds memory access when parsing enums
tracing: Fix incorrect enabling of trace events by boot cmdline
tracing: Handle ftrace_dump() atomic context in graph_trace_open()
The code that replaces the enum names with the enum values in the
tracepoints' format files could possible miss the end of string nul
character. This was caused by processing things like backslashes, quotes
and other tokens. After processing the tokens, a check for the nul
character needed to be done before continuing the loop, because the loop
incremented the pointer before doing the check, which could bypass the nul
character.
Link: http://lkml.kernel.org/r/552E661D.5060502@oracle.com
Reported-by: Sasha Levin <sasha.levin@oracle.com> # via KASan
Tested-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Fixes: 0c564a538a "tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There is a problem that trace events are not properly enabled with
boot cmdline. The problem is that if we pass "trace_event=kmem:mm_page_alloc"
to the boot cmdline, it enables all kmem trace events, and not just
the page_alloc event.
This is caused by the parsing mechanism. When we parse the cmdline, the buffer
contents is modified due to tokenization. And, if we use this buffer
again, we will get the wrong result.
Unfortunately, this buffer is be accessed three times to set trace events
properly at boot time. So, we need to handle this situation.
There is already code handling ",", but we need another for ":".
This patch adds it.
Link: http://lkml.kernel.org/r/1429159484-22977-1-git-send-email-iamjoonsoo.kim@lge.com
Cc: stable@vger.kernel.org # 3.19+
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
[ added missing return ret; ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The seq_printf return value, because it's frequently misused,
will eventually be converted to void.
See: commit 1f33c41c03 ("seq_file: Rename seq_overflow() to
seq_has_overflowed() and make public")
Miscellanea:
o Remove unused return value from trace_lookup_stack
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
relayfs and tracefs are dealing with inodes of their own;
those two act as filesystem drivers
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull perf changes from Ingo Molnar:
"Core kernel changes:
- One of the more interesting features in this cycle is the ability
to attach eBPF programs (user-defined, sandboxed bytecode executed
by the kernel) to kprobes.
This allows user-defined instrumentation on a live kernel image
that can never crash, hang or interfere with the kernel negatively.
(Right now it's limited to root-only, but in the future we might
allow unprivileged use as well.)
(Alexei Starovoitov)
- Another non-trivial feature is per event clockid support: this
allows, amongst other things, the selection of different clock
sources for event timestamps traced via perf.
This feature is sought by people who'd like to merge perf generated
events with external events that were measured with different
clocks:
- cluster wide profiling
- for system wide tracing with user-space events,
- JIT profiling events
etc. Matching perf tooling support is added as well, available via
the -k, --clockid <clockid> parameter to perf record et al.
(Peter Zijlstra)
Hardware enablement kernel changes:
- x86 Intel Processor Trace (PT) support: which is a hardware tracer
on steroids, available on Broadwell CPUs.
The hardware trace stream is directly output into the user-space
ring-buffer, using the 'AUX' data format extension that was added
to the perf core to support hardware constraints such as the
necessity to have the tracing buffer physically contiguous.
This patch-set was developed for two years and this is the result.
A simple way to make use of this is to use BTS tracing, the PT
driver emulates BTS output - available via the 'intel_bts' PMU.
More explicit PT specific tooling support is in the works as well -
will probably be ready by 4.2.
(Alexander Shishkin, Peter Zijlstra)
- x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
feature of Intel Xeon CPUs that allows the measurement and
allocation/partitioning of caches to individual workloads.
These kernel changes expose the measurement side as a new PMU
driver, which exposes various QoS related PMU events. (The
partitioning change is work in progress and is planned to be merged
as a cgroup extension.)
(Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
Waskiewicz Jr)
- x86 Intel Haswell LBR call stack support: this is a new Haswell
feature that allows the hardware recording of call chains, plus
tooling support. To activate this feature you have to enable it
via the new 'lbr' call-graph recording option:
perf record --call-graph lbr
perf report
or:
perf top --call-graph lbr
This hardware feature is a lot faster than stack walk or dwarf
based unwinding, but has some limitations:
- It reuses the current LBR facility, so LBR call stack and
branch record can not be enabled at the same time.
- It is only available for user-space callchains.
(Yan, Zheng)
- x86 Intel Broadwell CPU support and various event constraints and
event table fixes for earlier models.
(Andi Kleen)
- x86 Intel HT CPUs event scheduling workarounds. This is a complex
CPU bug affecting the SNB,IVB,HSW families that results in counter
value corruption. The mitigation code is automatically enabled and
is transparent.
(Maria Dimakopoulou, Stephane Eranian)
The perf tooling side had a ton of changes in this cycle as well, so
I'm only able to list the user visible changes here, in addition to
the tooling changes outlined above:
User visible changes affecting all tools:
- Improve support of compressed kernel modules (Jiri Olsa)
- Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
- Bash completion for subcommands (Yunlong Song)
- Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
- Support missing -f to override perf.data file ownership. (Yunlong Song)
- Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)
User visible changes in individual tools:
'perf data':
New tool for converting perf.data to other formats, initially
for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
Sebastian Siewior)
'perf diff':
Add --kallsyms option (David Ahern)
'perf list':
Allow listing events with 'tracepoint' prefix (Yunlong Song)
Sort the output of the command (Yunlong Song)
'perf kmem':
Respect -i option (Jiri Olsa)
Print big numbers using thousands' group (Namhyung Kim)
Allow -v option (Namhyung Kim)
Fix alignment of slab result table (Namhyung Kim)
'perf probe':
Support multiple probes on different binaries on the same command line (Masami Hiramatsu)
Support unnamed union/structure members data collection. (Masami Hiramatsu)
Check kprobes blacklist when adding new events. (Masami Hiramatsu)
'perf record':
Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)
Support recording running/enabled time (Andi Kleen)
'perf sched':
Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)
'perf report' and 'perf top':
Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)
Indicate which callchain entries are annotated in the
TUI hists browser (Arnaldo Carvalho de Melo)
Add pid/tid filtering to 'report' and 'script' commands (David Ahern)
Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
events (Arnaldo Carvalho de Melo)
'perf stat':
Report unsupported events properly (Suzuki K. Poulose)
Output running time and run/enabled ratio in CSV mode (Andi Kleen)
'perf trace':
Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)
Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)
Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)
Dump stack on segfaults (Arnaldo Carvalho de Melo)
No need to explicitely enable evsels for workload started from perf, let it
be enabled via perf_event_attr.enable_on_exec, removing some events that take
place in the 'perf trace' before a workload is really started by it.
(Arnaldo Carvalho de Melo)
Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)
There's also been a ton of infrastructure work done, such as the
split-out of perf's build system into tools/build/ and other changes -
see the shortlog and changelog for details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
perf evlist: Fix type for references to data_head/tail
perf probe: Check the orphaned -x option
perf probe: Support multiple probes on different binaries
perf buildid-list: Fix segfault when show DSOs with hits
perf tools: Fix cross-endian analysis
perf tools: Fix error path to do closedir() when synthesizing threads
perf tools: Fix synthesizing fork_event.ppid for non-main thread
perf tools: Add 'I' event modifier for exclude_idle bit
perf report: Don't call map__kmap if map is NULL.
perf tests: Fix attr tests
perf probe: Fix ARM 32 building error
perf tools: Merge all perf_event_attr print functions
perf record: Add clockid parameter
perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
perf sched replay: Support using -f to override perf.data file ownership
perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
...
of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.
Tracepoints have helper functions for the TP_printk() called
__print_symbolic() and __print_flags() that lets a numeric number be
displayed as a a human comprehensible text. What is placed in the
TP_printk() is also shown in the tracepoint format file such that
user space tools like perf and trace-cmd can parse the binary data
and express the values too. Unfortunately, the way the TRACE_EVENT()
macro works, anything placed in the TP_printk() will be shown pretty
much exactly as is. The problem arises when enums are used. That's
because unlike macros, enums will not be changed into their values
by the C pre-processor. Thus, the enum string is exported to the
format file, and this makes it useless for user space tools.
The TRACE_DEFINE_ENUM() solves this by converting the enum strings
in the TP_printk() format into their number, and that is what is
shown to user space. For example, the tracepoint tlb_flush currently
has this in its format file:
__print_symbolic(REC->reason,
{ TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
{ TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
{ TLB_LOCAL_SHOOTDOWN, "local shootdown" },
{ TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })
After adding:
TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);
Its format file will contain this:
__print_symbolic(REC->reason,
{ 0, "flush on task switch" },
{ 1, "remote shootdown" },
{ 2, "local shootdown" },
{ 3, "local mm shootdown" })
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Merge tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"Some clean ups and small fixes, but the biggest change is the addition
of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.
Tracepoints have helper functions for the TP_printk() called
__print_symbolic() and __print_flags() that lets a numeric number be
displayed as a a human comprehensible text. What is placed in the
TP_printk() is also shown in the tracepoint format file such that user
space tools like perf and trace-cmd can parse the binary data and
express the values too. Unfortunately, the way the TRACE_EVENT()
macro works, anything placed in the TP_printk() will be shown pretty
much exactly as is. The problem arises when enums are used. That's
because unlike macros, enums will not be changed into their values by
the C pre-processor. Thus, the enum string is exported to the format
file, and this makes it useless for user space tools.
The TRACE_DEFINE_ENUM() solves this by converting the enum strings in
the TP_printk() format into their number, and that is what is shown to
user space. For example, the tracepoint tlb_flush currently has this
in its format file:
__print_symbolic(REC->reason,
{ TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
{ TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
{ TLB_LOCAL_SHOOTDOWN, "local shootdown" },
{ TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })
After adding:
TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);
Its format file will contain this:
__print_symbolic(REC->reason,
{ 0, "flush on task switch" },
{ 1, "remote shootdown" },
{ 2, "local shootdown" },
{ 3, "local mm shootdown" })"
* tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
tracing: Add enum_map file to show enums that have been mapped
writeback: Export enums used by tracepoint to user space
v4l: Export enums used by tracepoints to user space
SUNRPC: Export enums in tracepoints to user space
mm: tracing: Export enums in tracepoints to user space
irq/tracing: Export enums in tracepoints to user space
f2fs: Export the enums in the tracepoints to userspace
net/9p/tracing: Export enums in tracepoints to userspace
x86/tlb/trace: Export enums in used by tlb_flush tracepoint
tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()
tracing: Allow for modules to convert their enums to values
tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values
tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation
tracing: Give system name a pointer
brcmsmac: Move each system tracepoints to their own header
iwlwifi: Move each system tracepoints to their own header
mac80211: Move message tracepoints to their own header
tracing: Add TRACE_SYSTEM_VAR to xhci-hcd
tracing: Add TRACE_SYSTEM_VAR to kvm-s390
tracing: Add TRACE_SYSTEM_VAR to intel-sst
...
more than one release, as I had it ready for the 4.0 merge window, but
a last minute thing that needed to go into Linux first had to be done.
That was that perf hard coded the file system number when reading
/sys/kernel/debugfs/tracing directory making sure that the path had
the debugfs mount # before it would parse the tracing file. This broke
other use cases of perf, and the check is removed.
Now when mounting /sys/kernel/debug, tracefs is automatically mounted
in /sys/kernel/debug/tracing such that old tools will still see that
path as expected. But now system admins can mount tracefs directly
and not need to mount debugfs, which can expose security issues.
A new directory is created when tracefs is configured such that
system admins can now mount it separately (/sys/kernel/tracing).
This branch is based off of Al Viro's vfs debugfs_automount branch
at commit 163f9eb95a
debugfs: Provide a file creation function that also takes an initial size
to get the debugfs_create_automount() operation.
I just noticed that Al rebased the pull to add his Signed-off-by to
that commit, and the commit is now e59b4e9187.
I did a git diff of those two and see they are the same. Only the
latter has Al's SOB.
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Merge tag 'trace-4.1-tracefs' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracefs from Steven Rostedt:
"This adds the new tracefs file system.
This has been in linux-next for more than one release, as I had it
ready for the 4.0 merge window, but a last minute thing that needed to
go into Linux first had to be done. That was that perf hard coded the
file system number when reading /sys/kernel/debugfs/tracing directory
making sure that the path had the debugfs mount # before it would
parse the tracing file. This broke other use cases of perf, and the
check is removed.
Now when mounting /sys/kernel/debug, tracefs is automatically mounted
in /sys/kernel/debug/tracing such that old tools will still see that
path as expected. But now system admins can mount tracefs directly
and not need to mount debugfs, which can expose security issues. A
new directory is created when tracefs is configured such that system
admins can now mount it separately (/sys/kernel/tracing)"
* tag 'trace-4.1-tracefs' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Have mkdir and rmdir be part of tracefs
tracefs: Add directory /sys/kernel/tracing
tracing: Automatically mount tracefs on debugfs/tracing
tracing: Convert the tracing facility over to use tracefs
tracefs: Add new tracefs file system
tracing: Create cmdline tracer options on tracing fs init
tracing: Only create tracer options files if directory exists
debugfs: Provide a file creation function that also takes an initial size
Add a enum_map file in the tracing directory to see what enums have been
saved to convert in the print fmt files.
As this requires the enum mapping to be persistent in memory, it is only
created if the new config option CONFIG_TRACE_ENUM_MAP_FILE is enabled.
This is for debugging and will increase the persistent memory footprint
of the kernel.
Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Update the infrastructure such that modules that declare TRACE_DEFINE_ENUM()
will have those enums converted into their values in the tracepoint
print fmt strings.
Link: http://lkml.kernel.org/r/87vbhjp74q.fsf@rustcorp.com.au
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Several tracepoints use the helper functions __print_symbolic() or
__print_flags() and pass in enums that do the mapping between the
binary data stored and the value to print. This works well for reading
the ASCII trace files, but when the data is read via userspace tools
such as perf and trace-cmd, the conversion of the binary value to a
human string format is lost if an enum is used, as userspace does not
have access to what the ENUM is.
For example, the tracepoint trace_tlb_flush() has:
__print_symbolic(REC->reason,
{ TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
{ TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
{ TLB_LOCAL_SHOOTDOWN, "local shootdown" },
{ TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })
Which maps the enum values to the strings they represent. But perf and
trace-cmd do no know what value TLB_LOCAL_MM_SHOOTDOWN is, and would
not be able to map it.
With TRACE_DEFINE_ENUM(), developers can place these in the event header
files and ftrace will convert the enums to their values:
By adding:
TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);
$ cat /sys/kernel/debug/tracing/events/tlb/tlb_flush/format
[...]
__print_symbolic(REC->reason,
{ 0, "flush on task switch" },
{ 1, "remote shootdown" },
{ 2, "local shootdown" },
{ 3, "local mm shootdown" })
The above is what userspace expects to see, and tools do not need to
be modified to parse them.
Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org
Cc: Guilherme Cox <cox@computer.org>
Cc: Tony Luck <tony.luck@gmail.com>
Cc: Xie XiuQi <xiexiuqi@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Dynamically allocated trampolines call ftrace_ops_get_func to get the
function which they should call. For dynamic fops (FTRACE_OPS_FL_DYNAMIC
flag is set) ftrace_ops_list_func is always returned. This is reasonable
for static trampolines but goes against the main advantage of dynamic
ones, that is avoidance of going through the list of all registered
callbacks for functions that are only being traced by a single callback.
We can fix it by returning ops->func (or recursion safe version) from
ftrace_ops_get_func whenever it is possible for dynamic trampolines.
Note that dynamic trampolines are not allowed for dynamic fops if
CONFIG_PREEMPT=y.
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1501291023000.25445@pobox.suse.cz
Link: http://lkml.kernel.org/r/1424357773-13536-1-git-send-email-mbenes@suse.cz
Reported-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
So bpf_tracing.o depends on CONFIG_BPF_SYSCALL - but that's not its only
dependency, it also depends on the tracing infrastructure and on kprobes,
without which it will fail to build with:
In file included from kernel/trace/bpf_trace.c:14:0:
kernel/trace/trace.h: In function ‘trace_test_and_set_recursion’:
kernel/trace/trace.h:491:28: error: ‘struct task_struct’ has no member named ‘trace_recursion’
unsigned int val = current->trace_recursion;
[...]
It took quite some time to trigger this build failure, because right now
BPF_SYSCALL is very obscure, depends on CONFIG_EXPERT. So also make BPF_SYSCALL
more configurable, not just under CONFIG_EXPERT.
If BPF_SYSCALL, tracing and kprobes are enabled then enable the bpf_tracing
gateway as well.
We might want to make this an interactive option later on, although
I'd not complicate it unnecessarily: enabling BPF_SYSCALL is enough of
an indicator that the user wants BPF support.
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Debugging of BPF programs needs some form of printk from the
program, so let programs call limited trace_printk() with %d %u
%x %p modifiers only.
Similar to kernel modules, during program load verifier checks
whether program is calling bpf_trace_printk() and if so, kernel
allocates trace_printk buffers and emits big 'this is debug
only' banner.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-6-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
bpf_ktime_get_ns() is used by programs to compute time delta
between events or as a timestamp
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-5-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
BPF programs, attached to kprobes, provide a safe way to execute
user-defined BPF byte-code programs without being able to crash or
hang the kernel in any way. The BPF engine makes sure that such
programs have a finite execution time and that they cannot break
out of their sandbox.
The user interface is to attach to a kprobe via the perf syscall:
struct perf_event_attr attr = {
.type = PERF_TYPE_TRACEPOINT,
.config = event_id,
...
};
event_fd = perf_event_open(&attr,...);
ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
'prog_fd' is a file descriptor associated with BPF program
previously loaded.
'event_id' is an ID of the kprobe created.
Closing 'event_fd':
close(event_fd);
... automatically detaches BPF program from it.
BPF programs can call in-kernel helper functions to:
- lookup/update/delete elements in maps
- probe_read - wraper of probe_kernel_read() used to access any
kernel data structures
BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is
architecture dependent) and return 0 to ignore the event and 1 to store
kprobe event into the ring buffer.
Note, kprobes are a fundamentally _not_ a stable kernel ABI,
so BPF programs attached to kprobes must be recompiled for
every kernel version and user must supply correct LINUX_VERSION_CODE
in attr.kern_version during bpf_prog_load() call.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
add TRACE_EVENT_FL_KPROBE flag to differentiate kprobe type of
tracepoints, since bpf programs can only be attached to kprobe
type of PERF_TYPE_TRACEPOINT perf events.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-3-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A clean up of the recursive protection code changed
val = this_cpu_read(current_context);
val--;
val &= this_cpu_read(current_context);
to
val = this_cpu_read(current_context);
val &= val & (val - 1);
Which has a duplicate use of '&' as the above is the same as
val = val & (val - 1);
Actually, it would be best to remove that line altogether and
just add it to where it is used.
And Christoph even mentioned that it can be further compacted to
just a single line:
__this_cpu_and(current_context, __this_cpu_read(current_context) - 1);
Link: http://lkml.kernel.org/alpine.DEB.2.11.1503271423580.23114@gentwo.org
Suggested-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The commit that added a check for this to checkpatch says:
"Using weak declarations can have unintended link defects. The __weak on
the declaration causes non-weak definitions to become weak."
In this case, when a PowerPC kernel is built with CONFIG_KPROBE_EVENT
but not CONFIG_UPROBE_EVENT, it generates the following warning:
WARNING: 1 bad relocations
c0000000014f2190 R_PPC64_ADDR64 uprobes_fetch_type_table
This is fixed by passing the fetch_table arrays to
traceprobe_parse_probe_arg() which also means that they can never be NULL.
Link: http://lkml.kernel.org/r/20150312165834.4482cb48@canb.auug.org.au
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
TRACE_EVENT_FL_USE_CALL_FILTER flag in ftrace:functon event can be
removed. This flag was first introduced in commit
f306cc82a9 ("tracing: Update event filters for multibuffer").
Now, the only place uses this flag is ftrace:function, but the filter of
ftrace:function has a different code path with events/syscalls and
events/tracepoints. It uses ftrace_filter_write() and perf's
ftrace_profile_set_filter() to set the filter, the functionality of file
'tracing/events/ftrace/function/filter' is bypassed in function
init_pred(), in which case, neither call->filter nor file->filter is
used.
So we can safely remove TRACE_EVENT_FL_USE_CALL_FILTER flag from
ftrace:function events.
Link: http://lkml.kernel.org/r/1425367294-27852-1-git-send-email-hekuang@huawei.com
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It has come to my attention that this_cpu_read/write are horrible on
architectures other than x86. Worse yet, they actually disable
preemption or interrupts! This caused some unexpected tracing results
on ARM.
101.356868: preempt_count_add <-ring_buffer_lock_reserve
101.356870: preempt_count_sub <-ring_buffer_lock_reserve
The ring_buffer_lock_reserve has recursion protection that requires
accessing a per cpu variable. But since preempt_disable() is traced, it
too got traced while accessing the variable that is suppose to prevent
recursion like this.
The generic version of this_cpu_read() and write() are:
#define this_cpu_generic_read(pcp) \
({ typeof(pcp) ret__; \
preempt_disable(); \
ret__ = *this_cpu_ptr(&(pcp)); \
preempt_enable(); \
ret__; \
})
#define this_cpu_generic_to_op(pcp, val, op) \
do { \
unsigned long flags; \
raw_local_irq_save(flags); \
*__this_cpu_ptr(&(pcp)) op val; \
raw_local_irq_restore(flags); \
} while (0)
Which is unacceptable for locations that know they are within preempt
disabled or interrupt disabled locations.
Paul McKenney stated that __this_cpu_() versions produce much better code on
other architectures than this_cpu_() does, if we know that the call is done in
a preempt disabled location.
I also changed the recursive_unlock() to use two local variables instead
of accessing the per_cpu variable twice.
Link: http://lkml.kernel.org/r/20150317114411.GE3589@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/20150317104038.312e73d1@gandalf.local.home
Cc: stable@vger.kernel.org
Acked-by: Christoph Lameter <cl@linux.com>
Reported-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Tested-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Some archs (specifically PowerPC), are sensitive with the ordering of
the enabling of the calls to function tracing and setting of the
function to use to be traced.
That is, update_ftrace_function() sets what function the ftrace_caller
trampoline should call. Some archs require this to be set before
calling ftrace_run_update_code().
Another bug was discovered, that ftrace_startup_sysctl() called
ftrace_run_update_code() directly. If the function the ftrace_caller
trampoline changes, then it will not be updated. Instead a call
to ftrace_startup_enable() should be called because it tests to see
if the callback changed since the code was disabled, and will
tell the arch to update appropriately. Most archs do not need this
notification, but PowerPC does.
The problem could be seen by the following commands:
# echo 0 > /proc/sys/kernel/ftrace_enabled
# echo function > /sys/kernel/debug/tracing/current_tracer
# echo 1 > /proc/sys/kernel/ftrace_enabled
# cat /sys/kernel/debug/tracing/trace
The trace will show that function tracing was not active.
Cc: stable@vger.kernel.org # 2.6.27+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When ftrace is enabled globally through the proc interface, we must check if
ftrace_graph_active is set. If it is set, then we should also pass the
FTRACE_START_FUNC_RET command to ftrace_run_update_code(). Similarly, when
ftrace is disabled globally through the proc interface, we must check if
ftrace_graph_active is set. If it is set, then we should also pass the
FTRACE_STOP_FUNC_RET command to ftrace_run_update_code().
Consider the following situation.
# echo 0 > /proc/sys/kernel/ftrace_enabled
After this ftrace_enabled = 0.
# echo function_graph > /sys/kernel/debug/tracing/current_tracer
Since ftrace_enabled = 0, ftrace_enable_ftrace_graph_caller() is never
called.
# echo 1 > /proc/sys/kernel/ftrace_enabled
Now ftrace_enabled will be set to true, but still
ftrace_enable_ftrace_graph_caller() will not be called, which is not
desired.
Further if we execute the following after this:
# echo nop > /sys/kernel/debug/tracing/current_tracer
Now since ftrace_enabled is set it will call
ftrace_disable_ftrace_graph_caller(), which causes a kernel warning on
the ARM platform.
On the ARM platform, when ftrace_enable_ftrace_graph_caller() is called,
it checks whether the old instruction is a nop or not. If it's not a nop,
then it returns an error. If it is a nop then it replaces instruction at
that address with a branch to ftrace_graph_caller.
ftrace_disable_ftrace_graph_caller() behaves just the opposite. Therefore,
if generic ftrace code ever calls either ftrace_enable_ftrace_graph_caller()
or ftrace_disable_ftrace_graph_caller() consecutively two times in a row,
then it will return an error, which will cause the generic ftrace code to
raise a warning.
Note, x86 does not have an issue with this because the architecture
specific code for ftrace_enable_ftrace_graph_caller() and
ftrace_disable_ftrace_graph_caller() does not check the previous state,
and calling either of these functions twice in a row has no ill effect.
Link: http://lkml.kernel.org/r/e4fbe64cdac0dd0e86a3bf914b0f83c0b419f146.1425666454.git.panand@redhat.com
Cc: stable@vger.kernel.org # 2.6.31+
Signed-off-by: Pratyush Anand <panand@redhat.com>
[
removed extra if (ftrace_start_up) and defined ftrace_graph_active as 0
if CONFIG_FUNCTION_GRAPH_TRACER is not set.
]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When /proc/sys/kernel/ftrace_enabled is set to zero, all function
tracing is disabled. But the records that represent the functions
still hold information about the ftrace_ops that are hooked to them.
ftrace_ops may request "REGS" (have a full set of pt_regs passed to
the callback), or "TRAMP" (the ops has its own trampoline to use).
When the record is updated to represent the state of the ops hooked
to it, it sets "REGS_EN" and/or "TRAMP_EN" to state that the callback
points to the correct trampoline (REGS has its own trampoline).
When ftrace_enabled is set to zero, all ftrace locations are a nop,
so they do not point to any trampoline. But the _EN flags are still
set. This can cause the accounting to go wrong when ftrace_enabled
is cleared and an ops that has a trampoline is registered or unregistered.
For example, the following will cause ftrace to crash:
# echo function_graph > /sys/kernel/debug/tracing/current_tracer
# echo 0 > /proc/sys/kernel/ftrace_enabled
# echo nop > /sys/kernel/debug/tracing/current_tracer
# echo 1 > /proc/sys/kernel/ftrace_enabled
# echo function_graph > /sys/kernel/debug/tracing/current_tracer
As function_graph uses a trampoline, when ftrace_enabled is set to zero
the updates to the record are not done. When enabling function_graph
again, the record will still have the TRAMP_EN flag set, and it will
look for an op that has a trampoline other than the function_graph
ops, and fail to find one.
Cc: stable@vger.kernel.org # 3.17+
Reported-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
printk and friends can now format bitmaps using '%*pb[l]'. cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
o Several clean ups to the code
One such clean up was to convert to 64 bit time keeping, in the
ring buffer benchmark code.
o Adding of __print_array() helper macro for TRACE_EVENT()
o Updating the sample/trace_events/ to add samples of different ways to
make trace events. Lots of features have been added since the sample
code was made, and these features are mostly unknown. Developers
have been making their own hacks to do things that are already available.
o Performance improvements. Most notably, I found a performance bug where
a waiter that is waiting for a full page from the ring buffer will
see that a full page is not available, and go to sleep. The sched
event caused by it going to sleep would cause it to wake up again.
It would see that there was still not a full page, and go back to sleep
again, and that would wake it up again, until finally it would see a
full page. This change has been marked for stable.
Other improvements include removing global locks from fast paths.
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Merge tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"The updates included in this pull request for ftrace are:
o Several clean ups to the code
One such clean up was to convert to 64 bit time keeping, in the
ring buffer benchmark code.
o Adding of __print_array() helper macro for TRACE_EVENT()
o Updating the sample/trace_events/ to add samples of different ways
to make trace events. Lots of features have been added since the
sample code was made, and these features are mostly unknown.
Developers have been making their own hacks to do things that are
already available.
o Performance improvements. Most notably, I found a performance bug
where a waiter that is waiting for a full page from the ring buffer
will see that a full page is not available, and go to sleep. The
sched event caused by it going to sleep would cause it to wake up
again. It would see that there was still not a full page, and go
back to sleep again, and that would wake it up again, until finally
it would see a full page. This change has been marked for stable.
Other improvements include removing global locks from fast paths"
* tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ring-buffer: Do not wake up a splice waiter when page is not full
tracing: Fix unmapping loop in tracing_mark_write
tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT()
tracing: Add TRACE_EVENT_FN example
tracing: Add TRACE_EVENT_CONDITION sample
tracing: Update the TRACE_EVENT fields available in the sample code
tracing: Separate out initializing top level dir from instances
tracing: Make tracing_init_dentry_tr() static
trace: Use 64-bit timekeeping
tracing: Add array printing helper
tracing: Remove newline from trace_printk warning banner
tracing: Use IS_ERR() check for return value of tracing_init_dentry()
tracing: Remove unneeded includes of debugfs.h and fs.h
tracing: Remove taking of trace_types_lock in pipe files
tracing: Add ref count to tracer for when they are being read by pipe
Pull s390 updates from Martin Schwidefsky:
- The remaining patches for the z13 machine support: kernel build
option for z13, the cache synonym avoidance, SMT support,
compare-and-delay for spinloops and the CES5S crypto adapater.
- The ftrace support for function tracing with the gcc hotpatch option.
This touches common code Makefiles, Steven is ok with the changes.
- The hypfs file system gets an extension to access diagnose 0x0c data
in user space for performance analysis for Linux running under z/VM.
- The iucv hvc console gets wildcard spport for the user id filtering.
- The cacheinfo code is converted to use the generic infrastructure.
- Cleanup and bug fixes.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits)
s390/process: free vx save area when releasing tasks
s390/hypfs: Eliminate hypfs interval
s390/hypfs: Add diagnose 0c support
s390/cacheinfo: don't use smp_processor_id() in preemptible context
s390/zcrypt: fixed domain scanning problem (again)
s390/smp: increase maximum value of NR_CPUS to 512
s390/jump label: use different nop instruction
s390/jump label: add sanity checks
s390/mm: correct missing space when reporting user process faults
s390/dasd: cleanup profiling
s390/dasd: add locking for global_profile access
s390/ftrace: hotpatch support for function tracing
ftrace: let notrace function attribute disable hotpatching if necessary
ftrace: allow architectures to specify ftrace compile options
s390: reintroduce diag 44 calls for cpu_relax()
s390/zcrypt: Add support for new crypto express (CEX5S) adapter.
s390/zcrypt: Number of supported ap domains is not retrievable.
s390/spinlock: add compare-and-delay to lock wait loops
s390/tape: remove redundant if statement
s390/hvc_iucv: add simple wildcard matches to the iucv allow filter
...
When an application connects to the ring buffer via splice, it can only
read full pages. Splice does not work with partial pages. If there is
not enough data to fill a page, the splice command will either block
or return -EAGAIN (if set to nonblock).
Code was added where if the page is not full, to just sleep again.
The problem is, it will get woken up again on the next event. That
is, when something is written into the ring buffer, if there is a waiter
it will wake it up. The waiter would then check the buffer, see that
it still does not have enough data to fill a page and go back to sleep.
To make matters worse, when the waiter goes back to sleep, it could
cause another event, which would wake it back up again to see it
doesn't have enough data and sleep again. This produces a tremendous
overhead and fills the ring buffer with noise.
For example, recording sched_switch on an idle system for 10 seconds
produces 25,350,475 events!!!
Create another wait queue for those waiters wanting full pages.
When an event is written, it only wakes up waiters if there's a full
page of data. It does not wake up the waiter if the page is not yet
full.
After this change, recording sched_switch on an idle system for 10
seconds produces only 800 events. Getting rid of 25,349,675 useless
events (99.9969% of events!!), is something to take seriously.
Cc: stable@vger.kernel.org # 3.16+
Cc: Rabin Vincent <rabin@rab.in>
Fixes: e30f53aad2 "tracing: Do not busy wait in buffer splice"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
