# echo switch_mm:traceoff > /sys/kernel/tracing/set_ftrace_filter
will cause switch_mm to stop tracing by the traceoff command.
# echo -n switch_mm:traceoff > /sys/kernel/tracing/set_ftrace_filter
does nothing.
The reason is that the parsing in the write function only processes
commands if it finished parsing (there is white space written after the
command). That's to handle:
write(fd, "switch_mm:", 10);
write(fd, "traceoff", 8);
cases, where the command is broken over multiple writes.
The problem is if the file descriptor is closed, then the write call is
not processed, and the command needs to be processed in the release code.
The release code can handle matching of functions, but does not handle
commands.
Cc: stable@vger.kernel.org
Fixes: eda1e32855 ("tracing: handle broken names in ftrace filter")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It was reported that a fix to the ring buffer recursion detection would
cause a hung machine when performing suspend / resume testing. The
following backtrace was extracted from debugging that case:
Call Trace:
trace_clock_global+0x91/0xa0
__rb_reserve_next+0x237/0x460
ring_buffer_lock_reserve+0x12a/0x3f0
trace_buffer_lock_reserve+0x10/0x50
__trace_graph_return+0x1f/0x80
trace_graph_return+0xb7/0xf0
? trace_clock_global+0x91/0xa0
ftrace_return_to_handler+0x8b/0xf0
? pv_hash+0xa0/0xa0
return_to_handler+0x15/0x30
? ftrace_graph_caller+0xa0/0xa0
? trace_clock_global+0x91/0xa0
? __rb_reserve_next+0x237/0x460
? ring_buffer_lock_reserve+0x12a/0x3f0
? trace_event_buffer_lock_reserve+0x3c/0x120
? trace_event_buffer_reserve+0x6b/0xc0
? trace_event_raw_event_device_pm_callback_start+0x125/0x2d0
? dpm_run_callback+0x3b/0xc0
? pm_ops_is_empty+0x50/0x50
? platform_get_irq_byname_optional+0x90/0x90
? trace_device_pm_callback_start+0x82/0xd0
? dpm_run_callback+0x49/0xc0
With the following RIP:
RIP: 0010:native_queued_spin_lock_slowpath+0x69/0x200
Since the fix to the recursion detection would allow a single recursion to
happen while tracing, this lead to the trace_clock_global() taking a spin
lock and then trying to take it again:
ring_buffer_lock_reserve() {
trace_clock_global() {
arch_spin_lock() {
queued_spin_lock_slowpath() {
/* lock taken */
(something else gets traced by function graph tracer)
ring_buffer_lock_reserve() {
trace_clock_global() {
arch_spin_lock() {
queued_spin_lock_slowpath() {
/* DEAD LOCK! */
Tracing should *never* block, as it can lead to strange lockups like the
above.
Restructure the trace_clock_global() code to instead of simply taking a
lock to update the recorded "prev_time" simply use it, as two events
happening on two different CPUs that calls this at the same time, really
doesn't matter which one goes first. Use a trylock to grab the lock for
updating the prev_time, and if it fails, simply try again the next time.
If it failed to be taken, that means something else is already updating
it.
Link: https://lkml.kernel.org/r/20210430121758.650b6e8a@gandalf.local.home
Cc: stable@vger.kernel.org
Tested-by: Konstantin Kharlamov <hi-angel@yandex.ru>
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Fixes: b02414c8f0 ("ring-buffer: Fix recursion protection transitions between interrupt context") # started showing the problem
Fixes: 14131f2f98 ("tracing: implement trace_clock_*() APIs") # where the bug happened
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212761
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The default max PID is set by PID_MAX_DEFAULT, and the tracing
infrastructure uses this number to map PIDs to the comm names of the
tasks, such output of the trace can show names from the recorded PIDs in
the ring buffer. This mapping is also exported to user space via the
"saved_cmdlines" file in the tracefs directory.
But currently the mapping expects the PIDs to be less than
PID_MAX_DEFAULT, which is the default maximum and not the real maximum.
Recently, systemd will increases the maximum value of a PID on the system,
and when tasks are traced that have a PID higher than PID_MAX_DEFAULT, its
comm is not recorded. This leads to the entire trace to have "<...>" as
the comm name, which is pretty useless.
Instead, keep the array mapping the size of PID_MAX_DEFAULT, but instead
of just mapping the index to the comm, map a mask of the PID
(PID_MAX_DEFAULT - 1) to the comm, and find the full PID from the
map_cmdline_to_pid array (that already exists).
This bug goes back to the beginning of ftrace, but hasn't been an issue
until user space started increasing the maximum value of PIDs.
Link: https://lkml.kernel.org/r/20210427113207.3c601884@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: bc0c38d139 ("ftrace: latency tracer infrastructure")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The func_repeats event shows the output of the function tracer followed by
a count of the number of repeats the previous function had made, as well
as the timestamp of the last function that was repeated.
The printing of the function should be the same as is for the function it
is displaying. Reuse the code in trace_fn_trace() by making a helper
function print_fn_trace() and use it for trace_func_repeats_print().
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If the option is activated the function tracing record gets
consolidated in the cases when a single function is called number
of times consecutively. Instead of having an identical record for
each call of the function we will record only the first call
following by event showing the number of repeats.
Link: https://lkml.kernel.org/r/20210415181854.147448-7-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently the logic for dealing with the options for function tracing
has two different implementations. One is used when we set the flags
(in "static int func_set_flag()") and another used when we initialize
the tracer (in "static int function_trace_init()"). Those two
implementations are meant to do essentially the same thing and they
are both not very convenient for adding new options. In this patch
we add a helper function that provides a single implementation of
the logic for dealing with the options and we make it such that new
options can be easily added.
Link: https://lkml.kernel.org/r/20210415181854.147448-6-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This patch only provides the implementation of the method.
Later we will used it in a combination with a new option for
function tracing.
Link: https://lkml.kernel.org/r/20210415181854.147448-5-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The field is used to keep track of the consecutive (on the same CPU) calls
of a single function. This information is needed in order to consolidate
the function tracing record in the cases when a single function is called
number of times.
Link: https://lkml.kernel.org/r/20210415181854.147448-4-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The event aims to consolidate the function tracing record in the cases
when a single function is called number of times consecutively.
while (cond)
do_func();
This may happen in various scenarios (busy waiting for example).
The new ftrace event can be used to show repeated function events with
a single event and save space on the ring buffer
Link: https://lkml.kernel.org/r/20210415181854.147448-3-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The part of the code that prints the time of the trace record in
"int trace_print_context()" gets extracted in a static function. This
is done as a preparation for a following patch, in which we will define
a new ftrace event called "func_repeats". The new static method,
defined here, will be used by this new event to print the time of the
last repeat of a function that is consecutively called number of times.
Link: https://lkml.kernel.org/r/20210415181854.147448-2-y.karadz@gmail.com
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Commit b40c6eabfc ("ftrace: Simplify the calculation of page number for
ftrace_page->records") simplified the calculation of the number of pages
needed for each page group without having any empty pages, but it can be
simplified even further.
Link: https://lore.kernel.org/lkml/CAHk-=wjt9b7kxQ2J=aDNKbR1QBMB3Hiqb_hYcZbKsxGRSEb+gQ@mail.gmail.com/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Instead of saving the size of the records field of the ftrace_page, store
the order it uses to allocate the pages, as that is what is needed to know
in order to free the pages. This simplifies the code.
Link: https://lore.kernel.org/lkml/CAHk-=whyMxheOqXAORt9a7JK9gc9eHTgCJ55Pgs4p=X3RrQubQ@mail.gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ change log written by Steven Rostedt ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Needed to merge trace/ftrace/urgent to get:
Commit 59300b36f8 ("ftrace: Check if pages were allocated before calling free_pages()")
To clean up the code that is affected by it as well.
Commit cbc3b92ce0 fixed an issue to modify the macros of the stack trace
event so that user space could parse it properly. Originally the stack
trace format to user space showed that the called stack was a dynamic
array. But it is not actually a dynamic array, in the way that other
dynamic event arrays worked, and this broke user space parsing for it. The
update was to make the array look to have 8 entries in it. Helper
functions were added to make it parse it correctly, as the stack was
dynamic, but was determined by the size of the event stored.
Although this fixed user space on how it read the event, it changed the
internal structure used for the stack trace event. It changed the array
size from [0] to [8] (added 8 entries). This increased the size of the
stack trace event by 8 words. The size reserved on the ring buffer was the
size of the stack trace event plus the number of stack entries found in
the stack trace. That commit caused the amount to be 8 more than what was
needed because it did not expect the caller field to have any size. This
produced 8 entries of garbage (and reading random data) from the stack
trace event:
<idle>-0 [002] d... 1976396.837549: <stack trace>
=> trace_event_raw_event_sched_switch
=> __traceiter_sched_switch
=> __schedule
=> schedule_idle
=> do_idle
=> cpu_startup_entry
=> secondary_startup_64_no_verify
=> 0xc8c5e150ffff93de
=> 0xffff93de
=> 0
=> 0
=> 0xc8c5e17800000000
=> 0x1f30affff93de
=> 0x00000004
=> 0x200000000
Instead, subtract the size of the caller field from the size of the event
to make sure that only the amount needed to store the stack trace is
reserved.
Link: https://lore.kernel.org/lkml/your-ad-here.call-01617191565-ext-9692@work.hours/
Cc: stable@vger.kernel.org
Fixes: cbc3b92ce0 ("tracing: Set kernel_stack's caller size properly")
Reported-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It is possible that on error pg->size can be zero when getting its order,
which would return a -1 value. It is dangerous to pass in an order of -1
to free_pages(). Check if order is greater than or equal to zero before
calling free_pages().
Link: https://lore.kernel.org/lkml/20210330093916.432697c7@gandalf.local.home/
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It is a common mistake for someone writing a trace event to save a pointer
to a string in the TP_fast_assign() and then display that string pointer
in the TP_printk() with %s. The problem is that those two events may happen
a long time apart, where the source of the string may no longer exist.
The proper way to handle displaying any string that is not guaranteed to be
in the kernel core rodata section, is to copy it into the ring buffer via
the __string(), __assign_str() and __get_str() helper macros.
Add a check at run time while displaying the TP_printk() of events to make
sure that every %s referenced is safe to dereference, and if it is not,
trigger a warning and only show the address of the pointer, and the
dereferenced string if it can be safely retrieved with a
strncpy_from_kernel_nofault() call.
In order to not have to copy the parsing of vsnprintf() formats, or even
exporting its code, the verifier relies on vsnprintf() being able to
modify the va_list that is passed to it, and it remains modified after it
is called. This is the case for some architectures like x86_64, but other
architectures like x86_32 pass the va_list to vsnprintf() as a value not a
reference, and the verifier can not use it to parse the non string
arguments. Thus, at boot up, it is checked if vsnprintf() modifies the
passed in va_list or not, and a static branch will disable the verifier if
it's not compatible.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Trace events record data into the ring buffer at the time of the event. The
trace event has a printf logic to display the recorded data at a much later
time when the user reads the trace file. This makes using dereferencing
pointers unsafe if the dereferenced pointer points to the original source.
The safe way to handle this is to create an array within the trace event and
copy the source into the array. Then the dereference pointer may point to
that array.
As this is a easy mistake to make, a check is added to examine all trace
event print fmts to make sure that they are safe to use. This only checks
the various %p* dereferenced pointers like %pB, %pR, etc. It does not handle
dereferencing of strings, as there are some use cases that are OK to
dereference the source. That will be dealt with differently.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a tracing_event_time_stamp() API that checks if the event passed in is
not on the ring buffer but a pointer to the per CPU trace_buffered_event
which does not have its time stamp set yet.
If it is a pointer to the trace_buffered_event, then just return the
current time stamp that the ring buffer would produce.
Otherwise, return the time stamp from the event.
Link: https://lkml.kernel.org/r/20210316164114.131996180@goodmis.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The ring_buffer_event_time_stamp() must be only called by an event that has
not been committed yet, and is on the buffer that is passed in. This was
used to help debug converting the histogram logic over to using the new
time stamp code, and was proven to be very useful.
Add a verifier that can check that this is the case, and extra WARN_ONs to
catch unexpected use cases.
Link: https://lkml.kernel.org/r/20210316164113.987294354@goodmis.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently, the trace histograms relies on it using absolute time stamps to
trigger the tracing to not use the temp buffer if filters are set. That's
because the histograms need the full timestamp that is saved in the ring
buffer. That is no longer the case, as the ring_buffer_event_time_stamp()
can now return the time stamp for all events without all triggering a full
absolute time stamp.
Now that the absolute time stamp is an unrelated dependency to not using
the filters. There's nothing about having absolute timestamps to keep from
using the filter buffer. Instead, change the interface to explicitly state
to disable filter buffering that the histogram logic can use.
Link: https://lkml.kernel.org/r/20210316164113.847886563@goodmis.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Currently, ring_buffer_event_time_stamp() only returns an accurate time
stamp of the event if it has an absolute extended time stamp attached to
it. To make it more robust, use the event_stamp() in case the event does
not have an absolute value attached to it.
This will allow ring_buffer_event_time_stamp() to be used in more cases
than just histograms, and it will also allow histograms to not require
including absolute values all the time.
Link: https://lkml.kernel.org/r/20210316164113.704830885@goodmis.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The ring_buffer_event_time_stamp() is going to be updated to extract the
time stamp for the event without needing it to be set to have absolute
values for all events. But to do so, it needs the buffer that the event is
on as the buffer saves information for the event before it is committed to
the buffer.
If the trace buffer is disabled, a temporary buffer is used, and there's
no access to this buffer from the current histogram triggers, even though
it is passed to the trace event code.
Pass the buffer that the event is on all the way down to the histogram
triggers.
Link: https://lkml.kernel.org/r/20210316164113.542448131@goodmis.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a place to save the current event time stamp for each level of nesting.
This will be used to retrieve the time stamp of the current event before it
is committed.
Link: https://lkml.kernel.org/r/20210316164113.399089673@goodmis.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The exported use of ring_buffer_event_time_stamp() is going to become
different than how it is used internally. Move the internal logic out into a
static function called rb_event_time_stamp(), and have the internal callers
call that instead.
Link: https://lkml.kernel.org/r/20210316164113.257790481@goodmis.org
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Doing a
prctl(PR_SET_MM, PR_SET_MM_AUXV, addr, 1);
will copy 1 byte from userspace to (quite big) on-stack array
and then stash everything to mm->saved_auxv.
AT_NULL terminator will be inserted at the very end.
/proc/*/auxv handler will find that AT_NULL terminator
and copy original stack contents to userspace.
This devious scheme requires CAP_SYS_RESOURCE.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Make the GENERIC_IRQ_MULTI_HANDLER configuration correct
- Add a missing DT compatible string fir tge Ingenic driver
- Remove the pointless debugfs_file pointer from struct irqdomain
-----BEGIN PGP SIGNATURE-----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=PG58
-----END PGP SIGNATURE-----
Merge tag 'irq-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"A set of irqchip updates:
- Make the GENERIC_IRQ_MULTI_HANDLER configuration correct
- Add a missing DT compatible string for the Ingenic driver
- Remove the pointless debugfs_file pointer from struct irqdomain"
* tag 'irq-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/ingenic: Add support for the JZ4760
dt-bindings/irq: Add compatible string for the JZ4760B
irqchip: Do not blindly select CONFIG_GENERIC_IRQ_MULTI_HANDLER
ARM: ep93xx: Select GENERIC_IRQ_MULTI_HANDLER directly
irqdomain: Remove debugfs_file from struct irq_domain
lack of reevaluation of the timers which expire in softirq context under
certain circumstances, e.g. when the clock was set.
-----BEGIN PGP SIGNATURE-----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=GZmg
-----END PGP SIGNATURE-----
Merge tag 'timers-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
"A single fix in for hrtimers to prevent an interrupt storm caused by
the lack of reevaluation of the timers which expire in softirq context
under certain circumstances, e.g. when the clock was set"
* tag 'timers-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimer: Update softirq_expires_next correctly after __hrtimer_get_next_event()
- Prevent a NULL pointer dereference in the migration_stop_cpu()
mechanims
- Prevent self concurrency of affine_move_task()
- Small fixes and cleanups related to task migration/affinity setting
- Ensure that sync_runqueues_membarrier_state() is invoked on the current
CPU when it is in the cpu mask
-----BEGIN PGP SIGNATURE-----
iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmBOLHQTHHRnbHhAbGlu
dXRyb25peC5kZQAKCRCmGPVMDXSYoWqTEACQLldMda63sEBPzEh4s0y+s4BqUsUM
Pn5wVK1J91PZg1ofv4vLjIzKfjNuIbNNTswhux9kfb29LO0/KBd9BTYi442q4A+P
chMi0Amfp4AGYlwo5+RNwEFNDFr33TD2Ax83cJ6FIDlJzLj8DRfzyxtwBvXfBG5R
EZLTtKL30g20Y8N3nmQjvCInGvh0J1igr4lWXKtmvist7Ie3hW5jpvc8hF+VI0f+
C1JfHg6GRw2eSCVFaF9EEeqX8+Wce+MrWIjwwB363vIX82lc/XC2XVbvrsgpA2P8
sJaZz4KsOcXJLg9DWcN/OrpiMsgjnpKdMMsa3H2Uza8V3URtshpacb0wBWUpa1IA
R55oCv4aRst6hNcCW1ayOLSEOcR2A2qAW2/ktiWYDqerIqkSCezMktunmrOc/vrW
tmnEjlkYf0TNV54XREQ0Hr6OEnSIxqc9WrjbHUFbpv50YURqOCaHr19L0aOsemMJ
g1pJCNkQhv4gZSenM6Fgo5ucbWB2Nvzu/Y6g7B2VFcpa3K7fmRJZW2uU5FvhwbeQ
3ngvEwxMf3Rb6D7SpJyU41TYV9SqdOmoO4/UAFJ8YOlKp8biHCPmGh4+/QYza4Ky
BIfPKtpr7MnSuYayo0wYYcKG0nE+rRJrj0Y0MAtz+6SfRCEc5Vd0NfIPQeAxDTvp
oAITUrOuePiBrA==
=WSUq
-----END PGP SIGNATURE-----
Merge tag 'sched-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
"A set of scheduler updates:
- Prevent a NULL pointer dereference in the migration_stop_cpu()
mechanims
- Prevent self concurrency of affine_move_task()
- Small fixes and cleanups related to task migration/affinity setting
- Ensure that sync_runqueues_membarrier_state() is invoked on the
current CPU when it is in the cpu mask"
* tag 'sched-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/membarrier: fix missing local execution of ipi_sync_rq_state()
sched: Simplify set_affinity_pending refcounts
sched: Fix affine_move_task() self-concurrency
sched: Optimize migration_cpu_stop()
sched: Collate affine_move_task() stoppers
sched: Simplify migration_cpu_stop()
sched: Fix migration_cpu_stop() requeueing
- A fix for the static_call mechanism so it handles unaligned
addresses correctly.
- Make u64_stats_init() a macro so every instance gets a seperate lockdep
key.
- Make seqcount_latch_init() a macro as well to preserve the static
variable which is used for the lockdep key.
-----BEGIN PGP SIGNATURE-----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=iE+t
-----END PGP SIGNATURE-----
Merge tag 'locking-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
"A couple of locking fixes:
- A fix for the static_call mechanism so it handles unaligned
addresses correctly.
- Make u64_stats_init() a macro so every instance gets a seperate
lockdep key.
- Make seqcount_latch_init() a macro as well to preserve the static
variable which is used for the lockdep key"
* tag 'locking-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
seqlock,lockdep: Fix seqcount_latch_init()
u64_stats,lockdep: Fix u64_stats_init() vs lockdep
static_call: Fix the module key fixup
properly handle PID/TID for large PEBS.
- Handle the case properly when there's no PMU and therefore return an
empty list of perf MSRs for VMX to switch instead of reading random
garbage from the stack.
-----BEGIN PGP SIGNATURE-----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=djiL
-----END PGP SIGNATURE-----
Merge tag 'perf_urgent_for_v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
- Make sure PMU internal buffers are flushed for per-CPU events too and
properly handle PID/TID for large PEBS.
- Handle the case properly when there's no PMU and therefore return an
empty list of perf MSRs for VMX to switch instead of reading random
garbage from the stack.
* tag 'perf_urgent_for_v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/perf: Use RET0 as default for guest_get_msrs to handle "no PMU" case
perf/x86/intel: Set PERF_ATTACH_SCHED_CB for large PEBS and LBR
perf/core: Flush PMU internal buffers for per-CPU events
Merge misc fixes from Andrew Morton:
"28 patches.
Subsystems affected by this series: mm (memblock, pagealloc, hugetlb,
highmem, kfence, oom-kill, madvise, kasan, userfaultfd, memcg, and
zram), core-kernel, kconfig, fork, binfmt, MAINTAINERS, kbuild, and
ia64"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (28 commits)
zram: fix broken page writeback
zram: fix return value on writeback_store
mm/memcg: set memcg when splitting page
mm/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg and add nr_pages argument
ia64: fix ptrace(PTRACE_SYSCALL_INFO_EXIT) sign
ia64: fix ia64_syscall_get_set_arguments() for break-based syscalls
mm/userfaultfd: fix memory corruption due to writeprotect
kasan: fix KASAN_STACK dependency for HW_TAGS
kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC
mm/madvise: replace ptrace attach requirement for process_madvise
include/linux/sched/mm.h: use rcu_dereference in in_vfork()
kfence: fix reports if constant function prefixes exist
kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations
kfence: fix printk format for ptrdiff_t
linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP*
MAINTAINERS: exclude uapi directories in API/ABI section
binfmt_misc: fix possible deadlock in bm_register_write
mm/highmem.c: fix zero_user_segments() with start > end
hugetlb: do early cow when page pinned on src mm
mm: use is_cow_mapping() across tree where proper
...
When a new mm is created, its PASID should be cleared, i.e. the PASID is
initialized to its init state 0 on both ARM and X86.
This patch was part of the series introducing mm->pasid, but got lost
along the way [1]. It still makes sense to have it, because each address
space has a different PASID. And the IOMMU code in
iommu_sva_alloc_pasid() expects the pasid field of a new mm struct to be
cleared.
[1] https://lore.kernel.org/linux-iommu/YDgh53AcQHT+T3L0@otcwcpicx3.sc.intel.com/
Link: https://lkml.kernel.org/r/20210302103837.2562625-1-jean-philippe@linaro.org
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-----BEGIN PGP SIGNATURE-----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=40h0
-----END PGP SIGNATURE-----
Merge tag 'io_uring-5.12-2021-03-12' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
"Not quite as small this week as I had hoped, but at least this should
be the end of it. All the little known issues have been ironed out -
most of it little stuff, but cancelations being the bigger part. Only
minor tweaks and/or regular fixes expected beyond this point.
- Fix the creds tracking for async (io-wq and SQPOLL)
- Various SQPOLL fixes related to parking, sharing, forking, IOPOLL,
completions, and life times. Much simpler now.
- Make IO threads unfreezable by default, on account of a bug report
that had them spinning on resume. Honestly not quite sure why
thawing leaves us with a perpetual signal pending (causing the
spin), but for now make them unfreezable like there were in 5.11
and prior.
- Move personality_idr to xarray, solving a use-after-free related to
removing an entry from the iterator callback. Buffer idr needs the
same treatment.
- Re-org around and task vs context tracking, enabling the fixing of
cancelations, and then cancelation fixes on top.
- Various little bits of cleanups and hardening, and removal of now
dead parts"
* tag 'io_uring-5.12-2021-03-12' of git://git.kernel.dk/linux-block: (34 commits)
io_uring: fix OP_ASYNC_CANCEL across tasks
io_uring: cancel sqpoll via task_work
io_uring: prevent racy sqd->thread checks
io_uring: remove useless ->startup completion
io_uring: cancel deferred requests in try_cancel
io_uring: perform IOPOLL reaping if canceler is thread itself
io_uring: force creation of separate context for ATTACH_WQ and non-threads
io_uring: remove indirect ctx into sqo injection
io_uring: fix invalid ctx->sq_thread_idle
kernel: make IO threads unfreezable by default
io_uring: always wait for sqd exited when stopping SQPOLL thread
io_uring: remove unneeded variable 'ret'
io_uring: move all io_kiocb init early in io_init_req()
io-wq: fix ref leak for req in case of exit cancelations
io_uring: fix complete_post races for linked req
io_uring: add io_disarm_next() helper
io_uring: fix io_sq_offload_create error handling
io-wq: remove unused 'user' member of io_wq
io_uring: Convert personality_idr to XArray
io_uring: clean R_DISABLED startup mess
...
The io-wq threads were already marked as no-freeze, but the manager was
not. On resume, we perpetually have signal_pending() being true, and
hence the manager will loop and spin 100% of the time.
Just mark the tasks created by create_io_thread() as PF_NOFREEZE by
default, and remove any knowledge of it in io-wq and io_uring.
Reported-by: Kevin Locke <kevin@kevinlocke.name>
Tested-by: Kevin Locke <kevin@kevinlocke.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull networking fixes from David Miller:
1) Fix transmissions in dynamic SMPS mode in ath9k, from Felix Fietkau.
2) TX skb error handling fix in mt76 driver, also from Felix.
3) Fix BPF_FETCH atomic in x86 JIT, from Brendan Jackman.
4) Avoid double free of percpu pointers when freeing a cloned bpf prog.
From Cong Wang.
5) Use correct printf format for dma_addr_t in ath11k, from Geert
Uytterhoeven.
6) Fix resolve_btfids build with older toolchains, from Kun-Chuan
Hsieh.
7) Don't report truncated frames to mac80211 in mt76 driver, from
Lorenzop Bianconi.
8) Fix watcdog timeout on suspend/resume of stmmac, from Joakim Zhang.
9) mscc ocelot needs NET_DEVLINK selct in Kconfig, from Arnd Bergmann.
10) Fix sign comparison bug in TCP_ZEROCOPY_RECEIVE getsockopt(), from
Arjun Roy.
11) Ignore routes with deleted nexthop object in mlxsw, from Ido
Schimmel.
12) Need to undo tcp early demux lookup sometimes in nf_nat, from
Florian Westphal.
13) Fix gro aggregation for udp encaps with zero csum, from Daniel
Borkmann.
14) Make sure to always use imp*_ndo_send when necessaey, from Jason A.
Donenfeld.
15) Fix TRSCER masks in sh_eth driver from Sergey Shtylyov.
16) prevent overly huge skb allocationsd in qrtr, from Pavel Skripkin.
17) Prevent rx ring copnsumer index loss of sync in enetc, from Vladimir
Oltean.
18) Make sure textsearch copntrol block is large enough, from Wilem de
Bruijn.
19) Revert MAC changes to r8152 leading to instability, from Hates Wang.
20) Advance iov in 9p even for empty reads, from Jissheng Zhang.
21) Double hook unregister in nftables, from PabloNeira Ayuso.
22) Fix memleak in ixgbe, fropm Dinghao Liu.
23) Avoid dups in pkt scheduler class dumps, from Maximilian Heyne.
24) Various mptcp fixes from Florian Westphal, Paolo Abeni, and Geliang
Tang.
25) Fix DOI refcount bugs in cipso, from Paul Moore.
26) One too many irqsave in ibmvnic, from Junlin Yang.
27) Fix infinite loop with MPLS gso segmenting via virtio_net, from
Balazs Nemeth.
* git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net: (164 commits)
s390/qeth: fix notification for pending buffers during teardown
s390/qeth: schedule TX NAPI on QAOB completion
s390/qeth: improve completion of pending TX buffers
s390/qeth: fix memory leak after failed TX Buffer allocation
net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0
net: check if protocol extracted by virtio_net_hdr_set_proto is correct
net: dsa: xrs700x: check if partner is same as port in hsr join
net: lapbether: Remove netif_start_queue / netif_stop_queue
atm: idt77252: fix null-ptr-dereference
atm: uPD98402: fix incorrect allocation
atm: fix a typo in the struct description
net: qrtr: fix error return code of qrtr_sendmsg()
mptcp: fix length of ADD_ADDR with port sub-option
net: bonding: fix error return code of bond_neigh_init()
net: enetc: allow hardware timestamping on TX queues with tc-etf enabled
net: enetc: set MAC RX FIFO to recommended value
net: davicom: Use platform_get_irq_optional()
net: davicom: Fix regulator not turned off on driver removal
net: davicom: Fix regulator not turned off on failed probe
net: dsa: fix switchdev objects on bridge master mistakenly being applied on ports
...
There's no need to keep around a dentry pointer to a simple file that
debugfs itself can look up when we need to remove it from the system.
So simplify the code by deleting the variable and cleaning up the logic
around the debugfs file.
Cc: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/YCvYV53ZdzQSWY6w@kroah.com
hrtimer_force_reprogram() and hrtimer_interrupt() invokes
__hrtimer_get_next_event() to find the earliest expiry time of hrtimer
bases. __hrtimer_get_next_event() does not update
cpu_base::[softirq_]_expires_next to preserve reprogramming logic. That
needs to be done at the callsites.
hrtimer_force_reprogram() updates cpu_base::softirq_expires_next only when
the first expiring timer is a softirq timer and the soft interrupt is not
activated. That's wrong because cpu_base::softirq_expires_next is left
stale when the first expiring timer of all bases is a timer which expires
in hard interrupt context. hrtimer_interrupt() does never update
cpu_base::softirq_expires_next which is wrong too.
That becomes a problem when clock_settime() sets CLOCK_REALTIME forward and
the first soft expiring timer is in the CLOCK_REALTIME_SOFT base. Setting
CLOCK_REALTIME forward moves the clock MONOTONIC based expiry time of that
timer before the stale cpu_base::softirq_expires_next.
cpu_base::softirq_expires_next is cached to make the check for raising the
soft interrupt fast. In the above case the soft interrupt won't be raised
until clock monotonic reaches the stale cpu_base::softirq_expires_next
value. That's incorrect, but what's worse it that if the softirq timer
becomes the first expiring timer of all clock bases after the hard expiry
timer has been handled the reprogramming of the clockevent from
hrtimer_interrupt() will result in an interrupt storm. That happens because
the reprogramming does not use cpu_base::softirq_expires_next, it uses
__hrtimer_get_next_event() which returns the actual expiry time. Once clock
MONOTONIC reaches cpu_base::softirq_expires_next the soft interrupt is
raised and the storm subsides.
Change the logic in hrtimer_force_reprogram() to evaluate the soft and hard
bases seperately, update softirq_expires_next and handle the case when a
soft expiring timer is the first of all bases by comparing the expiry times
and updating the required cpu base fields. Split this functionality into a
separate function to be able to use it in hrtimer_interrupt() as well
without copy paste.
Fixes: 5da7016046 ("hrtimer: Implement support for softirq based hrtimers")
Reported-by: Mikael Beckius <mikael.beckius@windriver.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mikael Beckius <mikael.beckius@windriver.com>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210223160240.27518-1-anna-maria@linutronix.de
Sometimes the PMU internal buffers have to be flushed for per-CPU events
during a context switch, e.g., large PEBS. Otherwise, the perf tool may
report samples in locations that do not belong to the process where the
samples are processed in, because PEBS does not tag samples with PID/TID.
The current code only flush the buffers for a per-task event. It doesn't
check a per-CPU event.
Add a new event state flag, PERF_ATTACH_SCHED_CB, to indicate that the
PMU internal buffers have to be flushed for this event during a context
switch.
Add sched_cb_entry and perf_sched_cb_usages back to track the PMU/cpuctx
which is required to be flushed.
Only need to invoke the sched_task() for per-CPU events in this patch.
The per-task events have been handled in perf_event_context_sched_in/out
already.
Fixes: 9c964efa43 ("perf/x86/intel: Drain the PEBS buffer during context switches")
Reported-by: Gabriel Marin <gmx@google.com>
Originally-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20201130193842.10569-1-kan.liang@linux.intel.com
Provided the target address of a R_X86_64_PC32 relocation is aligned,
the low two bits should be invariant between the relative and absolute
value.
Turns out the address is not aligned and things go sideways, ensure we
transfer the bits in the absolute form when fixing up the key address.
Fixes: 73f44fe19d ("static_call: Allow module use without exposing static_call_key")
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20210225220351.GE4746@worktop.programming.kicks-ass.net
The function sync_runqueues_membarrier_state() should copy the
membarrier state from the @mm received as parameter to each runqueue
currently running tasks using that mm.
However, the use of smp_call_function_many() skips the current runqueue,
which is unintended. Replace by a call to on_each_cpu_mask().
Fixes: 227a4aadc7 ("sched/membarrier: Fix p->mm->membarrier_state racy load")
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org # 5.4.x+
Link: https://lore.kernel.org/r/74F1E842-4A84-47BF-B6C2-5407DFDD4A4A@gmail.com
Now that we have set_affinity_pending::stop_pending to indicate if a
stopper is in progress, and we have the guarantee that if that stopper
exists, it will (eventually) complete our @pending we can simplify the
refcount scheme by no longer counting the stopper thread.
Fixes: 6d337eab04 ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()")
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224131355.724130207@infradead.org
Consider:
sched_setaffinity(p, X); sched_setaffinity(p, Y);
Then the first will install p->migration_pending = &my_pending; and
issue stop_one_cpu_nowait(pending); and the second one will read
p->migration_pending and _also_ issue: stop_one_cpu_nowait(pending),
the _SAME_ @pending.
This causes stopper list corruption.
Add set_affinity_pending::stop_pending, to indicate if a stopper is in
progress.
Fixes: 6d337eab04 ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()")
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224131355.649146419@infradead.org
When the purpose of migration_cpu_stop() is to migrate the task to
'any' valid CPU, don't migrate the task when it's already running on a
valid CPU.
Fixes: 6d337eab04 ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()")
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224131355.569238629@infradead.org
The SCA_MIGRATE_ENABLE and task_running() cases are almost identical,
collapse them to avoid further duplication.
Fixes: 6d337eab04 ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()")
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224131355.500108964@infradead.org
When affine_move_task() issues a migration_cpu_stop(), the purpose of
that function is to complete that @pending, not any random other
p->migration_pending that might have gotten installed since.
This realization much simplifies migration_cpu_stop() and allows
further necessary steps to fix all this as it provides the guarantee
that @pending's stopper will complete @pending (and not some random
other @pending).
Fixes: 6d337eab04 ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()")
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224131355.430014682@infradead.org
