Commit Graph

30970 Commits

Author SHA1 Message Date
Navid Emamdoost
96c5c6e6a5 tracing: Have error path in predicate_parse() free its allocated memory
In predicate_parse, there is an error path that is not going to
out_free instead it returns directly which leads to a memory leak.

Link: http://lkml.kernel.org/r/20190920225800.3870-1-navid.emamdoost@gmail.com

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-28 17:13:39 -04:00
Nathan Chancellor
968e517093 tracing: Fix clang -Wint-in-bool-context warnings in IF_ASSIGN macro
After r372664 in clang, the IF_ASSIGN macro causes a couple hundred
warnings along the lines of:

kernel/trace/trace_output.c:1331:2: warning: converting the enum
constant to a boolean [-Wint-in-bool-context]
kernel/trace/trace.h:409:3: note: expanded from macro
'trace_assign_type'
                IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,
                ^
kernel/trace/trace.h:371:14: note: expanded from macro 'IF_ASSIGN'
                WARN_ON(id && (entry)->type != id);     \
                           ^
264 warnings generated.

This warning can catch issues with constructs like:

    if (state == A || B)

where the developer really meant:

    if (state == A || state == B)

This is currently the only occurrence of the warning in the kernel
tree across defconfig, allyesconfig, allmodconfig for arm32, arm64,
and x86_64. Add the implicit '!= 0' to the WARN_ON statement to fix
the warnings and find potential issues in the future.

Link: 28b38c277a
Link: https://github.com/ClangBuiltLinux/linux/issues/686
Link: http://lkml.kernel.org/r/20190926162258.466321-1-natechancellor@gmail.com

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-28 17:13:39 -04:00
Masami Hiramatsu
d2aea95a1a tracing/probe: Fix to check the difference of nr_args before adding probe
Steven reported that a test triggered:

==================================================================
 BUG: KASAN: slab-out-of-bounds in trace_kprobe_create+0xa9e/0xe40
 Read of size 8 at addr ffff8880c4f25a48 by task ftracetest/4798

 CPU: 2 PID: 4798 Comm: ftracetest Not tainted 5.3.0-rc6-test+ #30
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
 Call Trace:
  dump_stack+0x7c/0xc0
  ? trace_kprobe_create+0xa9e/0xe40
  print_address_description+0x6c/0x332
  ? trace_kprobe_create+0xa9e/0xe40
  ? trace_kprobe_create+0xa9e/0xe40
  __kasan_report.cold.6+0x1a/0x3b
  ? trace_kprobe_create+0xa9e/0xe40
  kasan_report+0xe/0x12
  trace_kprobe_create+0xa9e/0xe40
  ? print_kprobe_event+0x280/0x280
  ? match_held_lock+0x1b/0x240
  ? find_held_lock+0xac/0xd0
  ? fs_reclaim_release.part.112+0x5/0x20
  ? lock_downgrade+0x350/0x350
  ? kasan_unpoison_shadow+0x30/0x40
  ? __kasan_kmalloc.constprop.6+0xc1/0xd0
  ? trace_kprobe_create+0xe40/0xe40
  ? trace_kprobe_create+0xe40/0xe40
  create_or_delete_trace_kprobe+0x2e/0x60
  trace_run_command+0xc3/0xe0
  ? trace_panic_handler+0x20/0x20
  ? kasan_unpoison_shadow+0x30/0x40
  trace_parse_run_command+0xdc/0x163
  vfs_write+0xe1/0x240
  ksys_write+0xba/0x150
  ? __ia32_sys_read+0x50/0x50
  ? tracer_hardirqs_on+0x61/0x180
  ? trace_hardirqs_off_caller+0x43/0x110
  ? mark_held_locks+0x29/0xa0
  ? do_syscall_64+0x14/0x260
  do_syscall_64+0x68/0x260

Fix to check the difference of nr_args before adding probe
on existing probes. This also may set the error log index
bigger than the number of command parameters. In that case
it sets the error position is next to the last parameter.

Link: http://lkml.kernel.org/r/156966474783.3478.13217501608215769150.stgit@devnote2

Fixes: ca89bc071d ("tracing/kprobe: Add multi-probe per event support")
Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-28 17:07:53 -04:00
Srikar Dronamraju
f8d7ab2bde tracing/probe: Fix same probe event argument matching
Commit fe60b0ce8e ("tracing/probe: Reject exactly same probe event")
tries to reject a event which matches an already existing probe.

However it currently continues to match arguments and rejects adding a
probe even when the arguments don't match. Fix this by only rejecting a
probe if and only if all the arguments match.

Link: http://lkml.kernel.org/r/20190924114906.14038-1-srikar@linux.vnet.ibm.com

Fixes: fe60b0ce8e ("tracing/probe: Reject exactly same probe event")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-25 06:34:06 -04:00
Masami Hiramatsu
fe60b0ce8e tracing/probe: Reject exactly same probe event
Reject exactly same probe events as existing probes.

Multiprobe allows user to define multiple probes on same
event. If user appends a probe which exactly same definition
(same probe address and same arguments) on existing event,
the event will record same probe information twice.
That can be confusing users, so reject it.

Link: http://lkml.kernel.org/r/156879694602.31056.5533024778165036763.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-19 11:09:16 -04:00
Masami Hiramatsu
44d00dc7ce tracing/probe: Fix to allow user to enable events on unloaded modules
Fix to allow user to enable probe events on unloaded modules.

This operations was allowed before commit 60d53e2c3b ("tracing/probe:
Split trace_event related data from trace_probe"), because if users
need to probe module init functions, they have to enable those probe
events before loading module.

Link: http://lkml.kernel.org/r/156879693733.31056.9331322616994665167.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 60d53e2c3b ("tracing/probe: Split trace_event related data from trace_probe")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-19 09:55:42 -04:00
Masami Hiramatsu
d59fae6fea tracing/kprobe: Fix NULL pointer access in trace_porbe_unlink()
Fix NULL pointer access in trace_probe_unlink() by initializing
trace_probe.list correctly in trace_probe_init().

In the error case of trace_probe_init(), it can call trace_probe_unlink()
before initializing trace_probe.list member. This causes NULL pointer
dereference at list_del_init() in trace_probe_unlink().

Syzbot reported :

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8633 Comm: syz-executor797 Not tainted 5.3.0-rc8-next-20190915
#0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__list_del_entry_valid+0x85/0xf5 lib/list_debug.c:51
Code: 0f 84 e1 00 00 00 48 b8 22 01 00 00 00 00 ad de 49 39 c4 0f 84 e2 00
00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75
53 49 8b 14 24 4c 39 f2 0f 85 99 00 00 00 49 8d 7d
RSP: 0018:ffff888090a7f9d8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88809b6f90c0 RCX: ffffffff817c0ca9
RDX: 0000000000000000 RSI: ffffffff817c0a73 RDI: ffff88809b6f90c8
RBP: ffff888090a7f9f0 R08: ffff88809a04e600 R09: ffffed1015d26aed
R10: ffffed1015d26aec R11: ffff8880ae935763 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88809b6f90c0 R15: ffff88809b6f90d0
FS:  0000555556f99880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006cc090 CR3: 00000000962b2000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  __list_del_entry include/linux/list.h:131 [inline]
  list_del_init include/linux/list.h:190 [inline]
  trace_probe_unlink+0x1f/0x200 kernel/trace/trace_probe.c:959
  trace_probe_cleanup+0xd3/0x110 kernel/trace/trace_probe.c:973
  trace_probe_init+0x3f2/0x510 kernel/trace/trace_probe.c:1011
  alloc_trace_uprobe+0x5e/0x250 kernel/trace/trace_uprobe.c:353
  create_local_trace_uprobe+0x109/0x4a0 kernel/trace/trace_uprobe.c:1508
  perf_uprobe_init+0x131/0x210 kernel/trace/trace_event_perf.c:314
  perf_uprobe_event_init+0x106/0x1a0 kernel/events/core.c:8898
  perf_try_init_event+0x135/0x590 kernel/events/core.c:10184
  perf_init_event kernel/events/core.c:10228 [inline]
  perf_event_alloc.part.0+0x1b89/0x33d0 kernel/events/core.c:10505
  perf_event_alloc kernel/events/core.c:10887 [inline]
  __do_sys_perf_event_open+0xa2d/0x2d00 kernel/events/core.c:10989
  __se_sys_perf_event_open kernel/events/core.c:10871 [inline]
  __x64_sys_perf_event_open+0xbe/0x150 kernel/events/core.c:10871
  do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: http://lkml.kernel.org/r/156869709721.22406.5153754822203046939.stgit@devnote2

Reported-by: syzbot+2f807f4d3a2a4e87f18f@syzkaller.appspotmail.com
Fixes: ca89bc071d ("tracing/kprobe: Add multi-probe per event support")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-17 11:21:29 -04:00
Tom Zanussi
17f8607a16 tracing: Make sure variable reference alias has correct var_ref_idx
Original changelog from Steve Rostedt (except last sentence which
explains the problem, and the Fixes: tag):

I performed a three way histogram with the following commands:

echo 'irq_lat u64 lat pid_t pid' > synthetic_events
echo 'wake_lat u64 lat u64 irqlat pid_t pid' >> synthetic_events
echo 'hist:keys=common_pid:irqts=common_timestamp.usecs if function == 0xffffffff81200580' > events/timer/hrtimer_start/trigger
echo 'hist:keys=common_pid:lat=common_timestamp.usecs-$irqts:onmatch(timer.hrtimer_start).irq_lat($lat,pid) if common_flags & 1' > events/sched/sched_waking/trigger
echo 'hist:keys=pid:wakets=common_timestamp.usecs,irqlat=lat' > events/synthetic/irq_lat/trigger
echo 'hist:keys=next_pid:lat=common_timestamp.usecs-$wakets,irqlat=$irqlat:onmatch(synthetic.irq_lat).wake_lat($lat,$irqlat,next_pid)' > events/sched/sched_switch/trigger
echo 1 > events/synthetic/wake_lat/enable

Basically I wanted to see:

 hrtimer_start (calling function tick_sched_timer)

Note:

  # grep tick_sched_timer /proc/kallsyms
ffffffff81200580 t tick_sched_timer

And save the time of that, and then record sched_waking if it is called
in interrupt context and with the same pid as the hrtimer_start, it
will record the latency between that and the waking event.

I then look at when the task that is woken is scheduled in, and record
the latency between the wakeup and the task running.

At the end, the wake_lat synthetic event will show the wakeup to
scheduled latency, as well as the irq latency in from hritmer_start to
the wakeup. The problem is that I found this:

          <idle>-0     [007] d...   190.485261: wake_lat: lat=27 irqlat=190485230 pid=698
          <idle>-0     [005] d...   190.485283: wake_lat: lat=40 irqlat=190485239 pid=10
          <idle>-0     [002] d...   190.488327: wake_lat: lat=56 irqlat=190488266 pid=335
          <idle>-0     [005] d...   190.489330: wake_lat: lat=64 irqlat=190489262 pid=10
          <idle>-0     [003] d...   190.490312: wake_lat: lat=43 irqlat=190490265 pid=77
          <idle>-0     [005] d...   190.493322: wake_lat: lat=54 irqlat=190493262 pid=10
          <idle>-0     [005] d...   190.497305: wake_lat: lat=35 irqlat=190497267 pid=10
          <idle>-0     [005] d...   190.501319: wake_lat: lat=50 irqlat=190501264 pid=10

The irqlat seemed quite large! Investigating this further, if I had
enabled the irq_lat synthetic event, I noticed this:

          <idle>-0     [002] d.s.   249.429308: irq_lat: lat=164968 pid=335
          <idle>-0     [002] d...   249.429369: wake_lat: lat=55 irqlat=249429308 pid=335

Notice that the timestamp of the irq_lat "249.429308" is awfully
similar to the reported irqlat variable. In fact, all instances were
like this. It appeared that:

  irqlat=$irqlat

Wasn't assigning the old $irqlat to the new irqlat variable, but
instead was assigning the $irqts to it.

The issue is that assigning the old $irqlat to the new irqlat variable
creates a variable reference alias, but the alias creation code
forgets to make sure the alias uses the same var_ref_idx to access the
reference.

Link: http://lkml.kernel.org/r/1567375321.5282.12.camel@kernel.org

Cc: Linux Trace Devel <linux-trace-devel@vger.kernel.org>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: stable@vger.kernel.org
Fixes: 7e8b88a30b ("tracing: Add hist trigger support for variable reference aliases")
Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-17 11:21:29 -04:00
Andy Shevchenko
119cdbdb95 tracing: Be more clever when dumping hex in __print_hex()
Hex dump as many as 16 bytes at once in trace_print_hex_seq()
instead of byte-by-byte approach.

Link: http://lkml.kernel.org/r/20190806151543.86061-1-andriy.shevchenko@linux.intel.com

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-17 11:21:28 -04:00
Changbin Du
08468754c1 ftrace: Simplify ftrace hash lookup code in clear_func_from_hash()
Function ftrace_lookup_ip() will check empty hash table. So we don't
need extra check outside.

Link: http://lkml.kernel.org/r/20190910143336.13472-1-changbin.du@gmail.com

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-17 11:21:20 -04:00
Zhengjun Xing
ac68154626 tracing: Add "gfp_t" support in synthetic_events
Add "gfp_t" support in synthetic_events, then the "gfp_t" type
parameter in some functions can be traced.

Prints the gfp flags as hex in addition to the human-readable flag
string.  Example output:

  whoopsie-630 [000] ...1 78.969452: testevent: bar=b20 (GFP_ATOMIC|__GFP_ZERO)
    rcuc/0-11  [000] ...1 81.097555: testevent: bar=a20 (GFP_ATOMIC)
    rcuc/0-11  [000] ...1 81.583123: testevent: bar=a20 (GFP_ATOMIC)

Link: http://lkml.kernel.org/r/20190712015308.9908-1-zhengjun.xing@linux.intel.com

Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
[ Added printing of flag names ]
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-09-05 11:35:14 -04:00
Steven Rostedt (VMware)
a47b53e95a tracing: Rename tracing_reset() to tracing_reset_cpu()
The name tracing_reset() was a misnomer, as it really only reset a single
CPU buffer. Rename it to tracing_reset_cpu() and also make it static and
remove the prototype from trace.h, as it is only used in a single function.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:40 -04:00
Steven Rostedt (VMware)
58fe7a87db tracing: Document the stack trace algorithm in the comments
As the max stack tracer algorithm is not that easy to understand from the
code, add comments that explain the algorithm and mentions how
ARCH_FTRACE_SHIFT_STACK_TRACER affects it.

Link: http://lkml.kernel.org/r/20190806123455.487ac02b@gandalf.local.home

Suggested-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:40 -04:00
Steven Rostedt (VMware)
f7edb451fa tracing/arm64: Have max stack tracer handle the case of return address after data
Most archs (well at least x86) store the function call return address on the
stack before storing the local variables for the function. The max stack
tracer depends on this in its algorithm to display the stack size of each
function it finds in the back trace.

Some archs (arm64), may store the return address (from its link register)
just before calling a nested function. There's no reason to save the link
register on leaf functions, as it wont be updated. This breaks the algorithm
of the max stack tracer.

Add a new define ARCH_FTRACE_SHIFT_STACK_TRACER that an architecture may set
if it stores the return address (link register) after it stores the
function's local variables, and have the stack trace shift the values of the
mapped stack size to the appropriate functions.

Link: 20190802094103.163576-1-jiping.ma2@windriver.com

Reported-by: Jiping Ma <jiping.ma2@windriver.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:40 -04:00
Masami Hiramatsu
a42e3c4de9 tracing/probe: Add immediate string parameter support
Add immediate string parameter (\"string") support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching a string from
memory.

This feature looks odd, but imagine that you put a probe
on a code to trace some string data. If the code is
compiled into 2 instructions and 1 instruction has a
string on memory but other has no string since it is
optimized out. In that case, you can not fold those into
one event, even if ftrace supported multiple probes on
one event. With this feature, you can set a dummy string
like foo=\"(optimized)":string instead of something
like foo=+0(+0(%bp)):string.

Link: http://lkml.kernel.org/r/156095691687.28024.13372712423865047991.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:39 -04:00
Masami Hiramatsu
6218bf9f4d tracing/probe: Add immediate parameter support
Add immediate value parameter (\1234) support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching from memory
or register.

This feature looks odd, but imagine when you put a probe
on a code to trace some data. If the code is compiled into
2 instructions and 1 instruction has a value but other has
nothing since it is optimized out.
In that case, you can not fold those into one event, even
if ftrace supported multiple probes on one event.
With this feature, you can set a dummy value like
foo=\deadbeef instead of something like foo=%di.

Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:39 -04:00
Masami Hiramatsu
ab10d69eb7 tracing/uprobe: Add per-probe delete from event
Add per-probe delete method from one event passing the head of
definition. In other words, the events which match the head
N parameters are deleted.

Link: http://lkml.kernel.org/r/156095689811.28024.221706761151739433.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:39 -04:00
Masami Hiramatsu
eb5bf81330 tracing/kprobe: Add per-probe delete from event
Allow user to delete a probe from event. This is done by head
match. For example, if we have 2 probes on an event

$ cat kprobe_events
p:kprobes/testprobe _do_fork r1=%ax r2=%dx
p:kprobes/testprobe idle_fork r1=%ax r2=%cx

Then you can remove one of them by passing the head of definition
which identify the probe.

$ echo "-:kprobes/testprobe idle_fork" >> kprobe_events

Link: http://lkml.kernel.org/r/156095688848.28024.15798690082378432435.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:38 -04:00
Masami Hiramatsu
41af3cf587 tracing/uprobe: Add multi-probe per uprobe event support
Allow user to define several probes on one uprobe event.
Note that this only support appending method. So deleting
event will delete all probes on the event.

Link: http://lkml.kernel.org/r/156095687876.28024.13840331032234992863.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:38 -04:00
Masami Hiramatsu
ca89bc071d tracing/kprobe: Add multi-probe per event support
Add multi-probe per one event support to kprobe events.
User can define several different probes on one trace event
if those events have same "event signature",
e.g.

  # echo p:testevent _do_fork > kprobe_events
  # echo p:testevent fork_idle >> kprobe_events
  # kprobe_events
  p:kprobes/testevent _do_fork
  p:kprobes/testevent fork_idle

The event signature is defined by kprobe type (retprobe or not),
the number of args, argument names, and argument types.

Note that this only support appending method. Delete event
operation will delete all probes on the event.

Link: http://lkml.kernel.org/r/156095686913.28024.9357292202316540742.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:38 -04:00
Masami Hiramatsu
30199137c8 tracing/dynevent: Pass extra arguments to match operation
Pass extra arguments to match operation for checking
exact match. If the event doesn't support exact match,
it will be ignored.

Link: http://lkml.kernel.org/r/156095685930.28024.10405547027475590975.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:38 -04:00
Masami Hiramatsu
cb8e7a8d55 tracing/dynevent: Delete all matched events
When user gives an event name to delete, delete all
matched events instead of the first one.

This means if there are several events which have same
name but different group (subsystem) name, those are
removed if user passed only the event name, e.g.

  # cat kprobe_events
  p:group1/testevent _do_fork
  p:group2/testevent fork_idle
  # echo -:testevent >> kprobe_events
  # cat kprobe_events
  #

Link: http://lkml.kernel.org/r/156095684958.28024.16597826267117453638.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:38 -04:00
Masami Hiramatsu
60d53e2c3b tracing/probe: Split trace_event related data from trace_probe
Split the trace_event related data from trace_probe data structure
and introduce trace_probe_event data structure for its folder.
This trace_probe_event data structure can have multiple trace_probe.

Link: http://lkml.kernel.org/r/156095683995.28024.7552150340561557873.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:38 -04:00
Masami Hiramatsu
0bc11ed5ab kprobes: Allow kprobes coexist with livepatch
Allow kprobes which do not modify regs->ip, coexist with livepatch
by dropping FTRACE_OPS_FL_IPMODIFY from ftrace_ops.

User who wants to modify regs->ip (e.g. function fault injection)
must set a dummy post_handler to its kprobes when registering.
However, if such regs->ip modifying kprobes is set on a function,
that function can not be livepatched.

Link: http://lkml.kernel.org/r/156403587671.30117.5233558741694155985.stgit@devnote2

Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 12:19:10 -04:00
Jakub Kicinski
c68c9ec1c5 tracing: Correct kdoc formats
Fix the following kdoc warnings:

kernel/trace/trace.c:1579: warning: Function parameter or member 'tr' not described in 'update_max_tr_single'
kernel/trace/trace.c:1579: warning: Function parameter or member 'tsk' not described in 'update_max_tr_single'
kernel/trace/trace.c:1579: warning: Function parameter or member 'cpu' not described in 'update_max_tr_single'
kernel/trace/trace.c:1776: warning: Function parameter or member 'type' not described in 'register_tracer'
kernel/trace/trace.c:2239: warning: Function parameter or member 'task' not described in 'tracing_record_taskinfo'
kernel/trace/trace.c:2239: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo'
kernel/trace/trace.c:2269: warning: Function parameter or member 'prev' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:2269: warning: Function parameter or member 'next' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:2269: warning: Function parameter or member 'flags' not described in 'tracing_record_taskinfo_sched_switch'
kernel/trace/trace.c:3078: warning: Function parameter or member 'ip' not described in 'trace_vbprintk'
kernel/trace/trace.c:3078: warning: Function parameter or member 'fmt' not described in 'trace_vbprintk'
kernel/trace/trace.c:3078: warning: Function parameter or member 'args' not described in 'trace_vbprintk'

Link: http://lkml.kernel.org/r/20190828052549.2472-2-jakub.kicinski@netronome.com

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 06:51:56 -04:00
Xinpeng Liu
19a58ce1dc tracing/probe: Fix null pointer dereference
BUG: KASAN: null-ptr-deref in trace_probe_cleanup+0x8d/0xd0
Read of size 8 at addr 0000000000000000 by task syz-executor.0/9746
trace_probe_cleanup+0x8d/0xd0
free_trace_kprobe.part.14+0x15/0x50
alloc_trace_kprobe+0x23e/0x250

Link: http://lkml.kernel.org/r/1565220563-980-1-git-send-email-danielliu861@gmail.com

Fixes: e3dc9f898e ("tracing/probe: Add trace_event_call accesses APIs")
Signed-off-by: Xinpeng Liu <danielliu861@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 06:51:55 -04:00
Denis Efremov
595a438c78 tracing: Make exported ftrace_set_clr_event non-static
The function ftrace_set_clr_event is declared static and marked
EXPORT_SYMBOL_GPL(), which is at best an odd combination. Because the
function was decided to be a part of API, this commit removes the static
attribute and adds the declaration to the header.

Link: http://lkml.kernel.org/r/20190704172110.27041-1-efremov@linux.com

Fixes: f45d1225ad ("tracing: Kernel access to Ftrace instances")
Reviewed-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31 06:51:49 -04:00
Naveen N. Rao
5b0022dd32 ftrace: Check for successful allocation of hash
In register_ftrace_function_probe(), we are not checking the return
value of alloc_and_copy_ftrace_hash(). The subsequent call to
ftrace_match_records() may end up dereferencing the same. Add a check to
ensure this doesn't happen.

Link: http://lkml.kernel.org/r/26e92574f25ad23e7cafa3cf5f7a819de1832cbe.1562249521.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: 1ec3a81a0c ("ftrace: Have each function probe use its own ftrace_ops")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-30 16:49:07 -04:00
Steven Rostedt (VMware)
372e0d01da ftrace: Check for empty hash and comment the race with registering probes
The race between adding a function probe and reading the probes that exist
is very subtle. It needs a comment. Also, the issue can also happen if the
probe has has the EMPTY_HASH as its func_hash.

Cc: stable@vger.kernel.org
Fixes: 7b60f3d876 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-30 16:30:01 -04:00
Naveen N. Rao
7bd46644ea ftrace: Fix NULL pointer dereference in t_probe_next()
LTP testsuite on powerpc results in the below crash:

  Unable to handle kernel paging request for data at address 0x00000000
  Faulting instruction address: 0xc00000000029d800
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE SMP NR_CPUS=2048 NUMA PowerNV
  ...
  CPU: 68 PID: 96584 Comm: cat Kdump: loaded Tainted: G        W
  NIP:  c00000000029d800 LR: c00000000029dac4 CTR: c0000000001e6ad0
  REGS: c0002017fae8ba10 TRAP: 0300   Tainted: G        W
  MSR:  9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 28022422  XER: 20040000
  CFAR: c00000000029d90c DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 0
  ...
  NIP [c00000000029d800] t_probe_next+0x60/0x180
  LR [c00000000029dac4] t_mod_start+0x1a4/0x1f0
  Call Trace:
  [c0002017fae8bc90] [c000000000cdbc40] _cond_resched+0x10/0xb0 (unreliable)
  [c0002017fae8bce0] [c0000000002a15b0] t_start+0xf0/0x1c0
  [c0002017fae8bd30] [c0000000004ec2b4] seq_read+0x184/0x640
  [c0002017fae8bdd0] [c0000000004a57bc] sys_read+0x10c/0x300
  [c0002017fae8be30] [c00000000000b388] system_call+0x5c/0x70

The test (ftrace_set_ftrace_filter.sh) is part of ftrace stress tests
and the crash happens when the test does 'cat
$TRACING_PATH/set_ftrace_filter'.

The address points to the second line below, in t_probe_next(), where
filter_hash is dereferenced:
  hash = iter->probe->ops.func_hash->filter_hash;
  size = 1 << hash->size_bits;

This happens due to a race with register_ftrace_function_probe(). A new
ftrace_func_probe is created and added into the func_probes list in
trace_array under ftrace_lock. However, before initializing the filter,
we drop ftrace_lock, and re-acquire it after acquiring regex_lock. If
another process is trying to read set_ftrace_filter, it will be able to
acquire ftrace_lock during this window and it will end up seeing a NULL
filter_hash.

Fix this by just checking for a NULL filter_hash in t_probe_next(). If
the filter_hash is NULL, then this probe is just being added and we can
simply return from here.

Link: http://lkml.kernel.org/r/05e021f757625cbbb006fad41380323dbe4e3b43.1562249521.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: 7b60f3d876 ("ftrace: Dynamically create the probe ftrace_ops for the trace_array")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-30 16:23:47 -04:00
Linus Torvalds
5a13fc3d8b Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timekeeping fix from Thomas Gleixner:
 "A single fix for a regression caused by the generic VDSO
  implementation where a math overflow causes CLOCK_BOOTTIME to become a
  random number generator"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping/vsyscall: Prevent math overflow in BOOTTIME update
2019-08-25 10:08:01 -07:00
Linus Torvalds
8a04c2ee62 Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
 "Handle the worker management in situations where a task is scheduled
  out on a PI lock contention correctly and schedule a new worker if
  possible"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Schedule new worker even if PI-blocked
2019-08-25 10:06:12 -07:00
Linus Torvalds
05bbb9360a Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "Two small fixes for kprobes and perf:

   - Prevent a deadlock in kprobe_optimizer() causes by reverse lock
     ordering

   - Fix a comment typo"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kprobes: Fix potential deadlock in kprobe_optimizer()
  perf/x86: Fix typo in comment
2019-08-25 10:03:32 -07:00
Linus Torvalds
44c471e436 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Thomas Gleixner:
 "A single fix for a imbalanced kobject operation in the irq decriptor
  code which was unearthed by the new warnings in the kobject code"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Properly pair kobject_del() with kobject_add()
2019-08-25 10:00:21 -07:00
Linus Torvalds
f47edb59bb Merge branch 'akpm' (patches from Andrew)
Mergr misc fixes from Andrew Morton:
 "11 fixes"

Mostly VM fixes, one psi polling fix, and one parisc build fix.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm/kasan: fix false positive invalid-free reports with CONFIG_KASAN_SW_TAGS=y
  mm/zsmalloc.c: fix race condition in zs_destroy_pool
  mm/zsmalloc.c: migration can leave pages in ZS_EMPTY indefinitely
  mm, page_owner: handle THP splits correctly
  userfaultfd_release: always remove uffd flags and clear vm_userfaultfd_ctx
  psi: get poll_work to run when calling poll syscall next time
  mm: memcontrol: flush percpu vmevents before releasing memcg
  mm: memcontrol: flush percpu vmstats before releasing memcg
  parisc: fix compilation errrors
  mm, page_alloc: move_freepages should not examine struct page of reserved memory
  mm/z3fold.c: fix race between migration and destruction
2019-08-25 09:56:27 -07:00
Linus Torvalds
e67095fd2f dma-mapping fixes for 5.3-rc
Two fixes for regressions in this merge window:
 
  - select the Kconfig symbols for the noncoherent dma arch helpers
    on arm if swiotlb is selected, not just for LPAE to not break then
    Xen build, that uses swiotlb indirectly through swiotlb-xen
  - fix the page allocator fallback in dma_alloc_contiguous if the CMA
    allocation fails
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Merge tag 'dma-mapping-5.3-5' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:
 "Two fixes for regressions in this merge window:

   - select the Kconfig symbols for the noncoherent dma arch helpers on
     arm if swiotlb is selected, not just for LPAE to not break then Xen
     build, that uses swiotlb indirectly through swiotlb-xen

   - fix the page allocator fallback in dma_alloc_contiguous if the CMA
     allocation fails"

* tag 'dma-mapping-5.3-5' of git://git.infradead.org/users/hch/dma-mapping:
  dma-direct: fix zone selection after an unaddressable CMA allocation
  arm: select the dma-noncoherent symbols for all swiotlb builds
2019-08-24 20:00:11 -07:00
Jason Xing
7b2b55da1d psi: get poll_work to run when calling poll syscall next time
Only when calling the poll syscall the first time can user receive
POLLPRI correctly.  After that, user always fails to acquire the event
signal.

Reproduce case:
 1. Get the monitor code in Documentation/accounting/psi.txt
 2. Run it, and wait for the event triggered.
 3. Kill and restart the process.

The question is why we can end up with poll_scheduled = 1 but the work
not running (which would reset it to 0).  And the answer is because the
scheduling side sees group->poll_kworker under RCU protection and then
schedules it, but here we cancel the work and destroy the worker.  The
cancel needs to pair with resetting the poll_scheduled flag.

Link: http://lkml.kernel.org/r/1566357985-97781-1-git-send-email-joseph.qi@linux.alibaba.com
Signed-off-by: Jason Xing <kerneljasonxing@linux.alibaba.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Caspar Zhang <caspar@linux.alibaba.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-08-24 19:48:42 -07:00
Linus Torvalds
e3fb13b7e4 Modules fixes for v5.3-rc6
- Fix BUG_ON() being triggered in frob_text() due to non-page-aligned module
   sections
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules fixes from Jessica Yu:
 "Fix BUG_ON() being triggered in frob_text() due to non-page-aligned
  module sections"

* tag 'modules-for-v5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  modules: page-align module section allocations only for arches supporting strict module rwx
  modules: always page-align module section allocations
2019-08-23 09:22:00 -07:00
Thomas Gleixner
b99328a60a timekeeping/vsyscall: Prevent math overflow in BOOTTIME update
The VDSO update for CLOCK_BOOTTIME has a overflow issue as it shifts the
nanoseconds based boot time offset left by the clocksource shift. That
overflows once the boot time offset becomes large enough. As a consequence
CLOCK_BOOTTIME in the VDSO becomes a random number causing applications to
misbehave.

Fix it by storing a timespec64 representation of the offset when boot time
is adjusted and add that to the MONOTONIC base time value in the vdso data
page. Using the timespec64 representation avoids a 64bit division in the
update code.

Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Reported-by: Chris Clayton <chris2553@googlemail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908221257580.1983@nanos.tec.linutronix.de
2019-08-23 02:12:11 +02:00
He Zhe
3b5be16c7e modules: page-align module section allocations only for arches supporting strict module rwx
We should keep the case of "#define debug_align(X) (X)" for all arches
without CONFIG_HAS_STRICT_MODULE_RWX ability, which would save people, who
are sensitive to system size, a lot of memory when using modules,
especially for embedded systems. This is also the intention of the
original #ifdef... statement and still valid for now.

Note that this still keeps the effect of the fix of the following commit,
38f054d549 ("modules: always page-align module section allocations"),
since when CONFIG_ARCH_HAS_STRICT_MODULE_RWX is enabled, module pages are
aligned.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
2019-08-21 10:43:56 +02:00
Christoph Hellwig
90ae409f9e dma-direct: fix zone selection after an unaddressable CMA allocation
The new dma_alloc_contiguous hides if we allocate CMA or regular
pages, and thus fails to retry a ZONE_NORMAL allocation if the CMA
allocation succeeds but isn't addressable.  That means we either fail
outright or dip into a small zone that might not succeed either.

Thanks to Hillf Danton for debugging this issue.

Fixes: b1d2dc009d ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
2019-08-21 07:14:10 +09:00
Linus Torvalds
287c55ed7d Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull kernel thread signal handling fix from Eric Biederman:
 "I overlooked the fact that kernel threads are created with all signals
  set to SIG_IGN, and accidentally caused a regression in cifs and drbd
  when replacing force_sig with send_sig.

  This is my fix for that regression. I add a new function
  allow_kernel_signal which allows kernel threads to receive signals
  sent from the kernel, but continues to ignore all signals sent from
  userspace. This ensures the user space interface for cifs and drbd
  remain the same.

  These kernel threads depend on blocking networking calls which block
  until something is received or a signal is pending. Making receiving
  of signals somewhat necessary for these kernel threads.

  Perhaps someday we can cleanup those interfaces and remove
  allow_kernel_signal. If not allow_kernel_signal is pretty trivial and
  clearly documents what is going on so I don't think we will mind
  carrying it"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Allow cifs and drbd to receive their terminating signals
2019-08-19 16:17:59 -07:00
Michael Kelley
d0ff14fdc9 genirq: Properly pair kobject_del() with kobject_add()
If alloc_descs() fails before irq_sysfs_init() has run, free_desc() in the
cleanup path will call kobject_del() even though the kobject has not been
added with kobject_add().

Fix this by making the call to kobject_del() conditional on whether
irq_sysfs_init() has run.

This problem surfaced because commit aa30f47cf6 ("kobject: Add support
for default attribute groups to kobj_type") makes kobject_del() stricter
about pairing with kobject_add(). If the pairing is incorrrect, a WARNING
and backtrace occur in sysfs_remove_group() because there is no parent.

[ tglx: Add a comment to the code and make it work with CONFIG_SYSFS=n ]

Fixes: ecb3f394c5 ("genirq: Expose interrupt information through sysfs")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1564703564-4116-1-git-send-email-mikelley@microsoft.com
2019-08-19 21:41:19 +02:00
Eric W. Biederman
33da8e7c81 signal: Allow cifs and drbd to receive their terminating signals
My recent to change to only use force_sig for a synchronous events
wound up breaking signal reception cifs and drbd.  I had overlooked
the fact that by default kthreads start out with all signals set to
SIG_IGN.  So a change I thought was safe turned out to have made it
impossible for those kernel thread to catch their signals.

Reverting the work on force_sig is a bad idea because what the code
was doing was very much a misuse of force_sig.  As the way force_sig
ultimately allowed the signal to happen was to change the signal
handler to SIG_DFL.  Which after the first signal will allow userspace
to send signals to these kernel threads.  At least for
wake_ack_receiver in drbd that does not appear actively wrong.

So correct this problem by adding allow_kernel_signal that will allow
signals whose siginfo reports they were sent by the kernel through,
but will not allow userspace generated signals, and update cifs and
drbd to call allow_kernel_signal in an appropriate place so that their
thread can receive this signal.

Fixing things this way ensures that userspace won't be able to send
signals and cause problems, that it is clear which signals the
threads are expecting to receive, and it guarantees that nothing
else in the system will be affected.

This change was partly inspired by similar cifs and drbd patches that
added allow_signal.

Reported-by: ronnie sahlberg <ronniesahlberg@gmail.com>
Reported-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Tested-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Cc: Steve French <smfrench@gmail.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Fixes: 247bc9470b ("cifs: fix rmmod regression in cifs.ko caused by force_sig changes")
Fixes: 72abe3bcf0 ("signal/cifs: Fix cifs_put_tcp_session to call send_sig instead of force_sig")
Fixes: fee109901f ("signal/drbd: Use send_sig not force_sig")
Fixes: 3cf5d076fb ("signal: Remove task parameter from force_sig")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-08-19 06:34:13 -05:00
Andrea Righi
f1c6ece237 kprobes: Fix potential deadlock in kprobe_optimizer()
lockdep reports the following deadlock scenario:

 WARNING: possible circular locking dependency detected

 kworker/1:1/48 is trying to acquire lock:
 000000008d7a62b2 (text_mutex){+.+.}, at: kprobe_optimizer+0x163/0x290

 but task is already holding lock:
 00000000850b5e2d (module_mutex){+.+.}, at: kprobe_optimizer+0x31/0x290

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (module_mutex){+.+.}:
        __mutex_lock+0xac/0x9f0
        mutex_lock_nested+0x1b/0x20
        set_all_modules_text_rw+0x22/0x90
        ftrace_arch_code_modify_prepare+0x1c/0x20
        ftrace_run_update_code+0xe/0x30
        ftrace_startup_enable+0x2e/0x50
        ftrace_startup+0xa7/0x100
        register_ftrace_function+0x27/0x70
        arm_kprobe+0xb3/0x130
        enable_kprobe+0x83/0xa0
        enable_trace_kprobe.part.0+0x2e/0x80
        kprobe_register+0x6f/0xc0
        perf_trace_event_init+0x16b/0x270
        perf_kprobe_init+0xa7/0xe0
        perf_kprobe_event_init+0x3e/0x70
        perf_try_init_event+0x4a/0x140
        perf_event_alloc+0x93a/0xde0
        __do_sys_perf_event_open+0x19f/0xf30
        __x64_sys_perf_event_open+0x20/0x30
        do_syscall_64+0x65/0x1d0
        entry_SYSCALL_64_after_hwframe+0x49/0xbe

 -> #0 (text_mutex){+.+.}:
        __lock_acquire+0xfcb/0x1b60
        lock_acquire+0xca/0x1d0
        __mutex_lock+0xac/0x9f0
        mutex_lock_nested+0x1b/0x20
        kprobe_optimizer+0x163/0x290
        process_one_work+0x22b/0x560
        worker_thread+0x50/0x3c0
        kthread+0x112/0x150
        ret_from_fork+0x3a/0x50

 other info that might help us debug this:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(module_mutex);
                                lock(text_mutex);
                                lock(module_mutex);
   lock(text_mutex);

  *** DEADLOCK ***

As a reproducer I've been using bcc's funccount.py
(https://github.com/iovisor/bcc/blob/master/tools/funccount.py),
for example:

 # ./funccount.py '*interrupt*'

That immediately triggers the lockdep splat.

Fix by acquiring text_mutex before module_mutex in kprobe_optimizer().

Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: d5b844a2cf ("ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()")
Link: http://lkml.kernel.org/r/20190812184302.GA7010@xps-13
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-08-19 12:22:19 +02:00
Sebastian Andrzej Siewior
b0fdc01354 sched/core: Schedule new worker even if PI-blocked
If a task is PI-blocked (blocking on sleeping spinlock) then we don't want to
schedule a new kworker if we schedule out due to lock contention because !RT
does not do that as well. A spinning spinlock disables preemption and a worker
does not schedule out on lock contention (but spin).

On RT the RW-semaphore implementation uses an rtmutex so
tsk_is_pi_blocked() will return true if a task blocks on it. In this case we
will now start a new worker which may deadlock if one worker is waiting on
progress from another worker. Since a RW-semaphore starts a new worker on !RT,
we should do the same on RT.

XFS is able to trigger this deadlock.

Allow to schedule new worker if the current worker is PI-blocked.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190816160626.12742-1-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-08-19 10:57:26 +02:00
Linus Torvalds
5bba5c9c86 SPDX fixes for 5.3-rc5
Here are 4 small SPDX fixes for 5.3-rc5.  A few style fixes for some
 SPDX comments, added an SPDX tag for one file, and fix up some GPL
 boilerplate for another file.
 
 All of these have been in linux-next for a few weeks with no reported
 issues (they are comment changes only, so that's to be expected...)
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

Pull SPDX fixes from Greg KH:
 "Here are four small SPDX fixes for 5.3-rc5.

  A few style fixes for some SPDX comments, added an SPDX tag for one
  file, and fix up some GPL boilerplate for another file.

  All of these have been in linux-next for a few weeks with no reported
  issues (they are comment changes only, so that's to be expected...)"

* tag 'spdx-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
  i2c: stm32: Use the correct style for SPDX License Identifier
  intel_th: Use the correct style for SPDX License Identifier
  coccinelle: api/atomic_as_refcounter: add SPDX License Identifier
  kernel/configs: Replace GPL boilerplate code with SPDX identifier
2019-08-18 09:26:16 -07:00
Linus Torvalds
2d63ba3e41 Power management fixes for 5.3-rc5
- Disable NVMe power optimization related to suspend-to-idle added
    recently on systems where PCIe ASPM is not able to put PCIe links
    into low-power states to prevent excess power from being drawn by
    the system while suspended (Rafael Wysocki).
 
  - Make the schedutil governor handle frequency limits changes
    properly in all cases (Viresh Kumar).
 
  - Prevent the cpufreq core from treating positive values returned
    by dev_pm_qos_update_request() as errors (Viresh Kumar).
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Merge tag 'pm-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These add a check to avoid recent suspend-to-idle power regression on
  systems with NVMe drives where the PCIe ASPM policy is "performance"
  (or when the kernel is built without ASPM support), fix an issue
  related to frequency limits in the schedutil cpufreq governor and fix
  a mistake related to the PM QoS usage in the cpufreq core introduced
  recently.

  Specifics:

   - Disable NVMe power optimization related to suspend-to-idle added
     recently on systems where PCIe ASPM is not able to put PCIe links
     into low-power states to prevent excess power from being drawn by
     the system while suspended (Rafael Wysocki).

   - Make the schedutil governor handle frequency limits changes
     properly in all cases (Viresh Kumar).

   - Prevent the cpufreq core from treating positive values returned by
     dev_pm_qos_update_request() as errors (Viresh Kumar)"

* tag 'pm-5.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled
  PCI/ASPM: Add pcie_aspm_enabled()
  cpufreq: schedutil: Don't skip freq update when limits change
  cpufreq: dev_pm_qos_update_request() can return 1 on success
2019-08-16 09:13:16 -07:00
Rafael J. Wysocki
a3ee2477c4 Merge branch 'pm-cpufreq'
* pm-cpufreq:
  cpufreq: schedutil: Don't skip freq update when limits change
  cpufreq: dev_pm_qos_update_request() can return 1 on success
2019-08-16 14:24:51 +02:00
Linus Torvalds
e83b009c5c dma-mapping fixes for 5.3-rc
- fix the handling of the bus_dma_mask in dma_get_required_mask, which
    caused a regression in this merge window (Lucas Stach)
  - fix a regression in the handling of DMA_ATTR_NO_KERNEL_MAPPING (me)
  - fix dma_mmap_coherent to not cause page attribute mismatches on
    coherent architectures like x86 (me)
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Merge tag 'dma-mapping-5.3-4' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - fix the handling of the bus_dma_mask in dma_get_required_mask, which
   caused a regression in this merge window (Lucas Stach)

 - fix a regression in the handling of DMA_ATTR_NO_KERNEL_MAPPING (me)

 - fix dma_mmap_coherent to not cause page attribute mismatches on
   coherent architectures like x86 (me)

* tag 'dma-mapping-5.3-4' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: fix page attributes for dma_mmap_*
  dma-direct: don't truncate dma_required_mask to bus addressing capabilities
  dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING
2019-08-14 10:31:11 -07:00