<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/perf, branch v6.1.136</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>perf tools: annotate asm_pure_loop.S</title>
<updated>2025-04-10T12:33:37+00:00</updated>
<author>
<name>Marcus Meissner</name>
<email>meissner@suse.de</email>
</author>
<published>2025-03-23T08:53:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=546685793f4cbd3ae66c552329878dc5e60e320a'/>
<id>546685793f4cbd3ae66c552329878dc5e60e320a</id>
<content type='text'>
[ Upstream commit 9a352a90e88a041f4b26d359493e12a7f5ae1a6a ]

Annotate so it is built with non-executable stack.

Fixes: 8b97519711c3 ("perf test: Add asm pureloop test tool")
Signed-off-by: Marcus Meissner &lt;meissner@suse.de&gt;
Reviewed-by: Leo Yan &lt;leo.yan@arm.com&gt;
Link: https://lore.kernel.org/r/20250323085410.23751-1-meissner@suse.de
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 9a352a90e88a041f4b26d359493e12a7f5ae1a6a ]

Annotate so it is built with non-executable stack.

Fixes: 8b97519711c3 ("perf test: Add asm pureloop test tool")
Signed-off-by: Marcus Meissner &lt;meissner@suse.de&gt;
Reviewed-by: Leo Yan &lt;leo.yan@arm.com&gt;
Link: https://lore.kernel.org/r/20250323085410.23751-1-meissner@suse.de
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf python: Check if there is space to copy all the event</title>
<updated>2025-04-10T12:33:37+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2025-03-12T20:31:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c8b28c1276241834f94bd6993724cb3588fe1e33'/>
<id>c8b28c1276241834f94bd6993724cb3588fe1e33</id>
<content type='text'>
[ Upstream commit 89aaeaf84231157288035b366cb6300c1c6cac64 ]

The pyrf_event__new() method copies the event obtained from the perf
ring buffer to a structure that will then be turned into a python object
for further consumption, so it copies perf_event.header.size bytes to
its 'event' member:

  $ pahole -C pyrf_event /tmp/build/perf-tools-next/python/perf.cpython-312-x86_64-linux-gnu.so
  struct pyrf_event {
  	PyObject                   ob_base;              /*     0    16 */
  	struct evsel *             evsel;                /*    16     8 */
  	struct perf_sample         sample;               /*    24   312 */

  	/* XXX last struct has 7 bytes of padding, 2 holes */

  	/* --- cacheline 5 boundary (320 bytes) was 16 bytes ago --- */
  	union perf_event           event;                /*   336  4168 */

  	/* size: 4504, cachelines: 71, members: 4 */
  	/* member types with holes: 1, total: 2 */
  	/* paddings: 1, sum paddings: 7 */
  	/* last cacheline: 24 bytes */
  };

  $

It was doing so without checking if the event just obtained has more
than that space, fix it.

This isn't a proper, final solution, as we need to support larger
events, but for the time being we at least bounds check and document it.

Fixes: 877108e42b1b9ba6 ("perf tools: Initial python binding")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20250312203141.285263-7-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 89aaeaf84231157288035b366cb6300c1c6cac64 ]

The pyrf_event__new() method copies the event obtained from the perf
ring buffer to a structure that will then be turned into a python object
for further consumption, so it copies perf_event.header.size bytes to
its 'event' member:

  $ pahole -C pyrf_event /tmp/build/perf-tools-next/python/perf.cpython-312-x86_64-linux-gnu.so
  struct pyrf_event {
  	PyObject                   ob_base;              /*     0    16 */
  	struct evsel *             evsel;                /*    16     8 */
  	struct perf_sample         sample;               /*    24   312 */

  	/* XXX last struct has 7 bytes of padding, 2 holes */

  	/* --- cacheline 5 boundary (320 bytes) was 16 bytes ago --- */
  	union perf_event           event;                /*   336  4168 */

  	/* size: 4504, cachelines: 71, members: 4 */
  	/* member types with holes: 1, total: 2 */
  	/* paddings: 1, sum paddings: 7 */
  	/* last cacheline: 24 bytes */
  };

  $

It was doing so without checking if the event just obtained has more
than that space, fix it.

This isn't a proper, final solution, as we need to support larger
events, but for the time being we at least bounds check and document it.

Fixes: 877108e42b1b9ba6 ("perf tools: Initial python binding")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20250312203141.285263-7-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf python: Don't keep a raw_data pointer to consumed ring buffer space</title>
<updated>2025-04-10T12:33:37+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2025-03-12T20:31:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5a393187e5a9c651d9efa9645bc13da4f7f7af3d'/>
<id>5a393187e5a9c651d9efa9645bc13da4f7f7af3d</id>
<content type='text'>
[ Upstream commit f3fed3ae34d606819d87a63d970cc3092a5be7ab ]

When processing tracepoints the perf python binding was parsing the
event before calling perf_mmap__consume(&amp;md-&gt;core) in
pyrf_evlist__read_on_cpu().

But part of this event parsing was to set the perf_sample-&gt;raw_data
pointer to the payload of the event, which then could be overwritten by
other event before tracepoint fields were asked for via event.prev_comm
in a python program, for instance.

This also happened with other fields, but strings were were problems
were surfacing, as there is UTF-8 validation for the potentially garbled
data.

This ended up showing up as (with some added debugging messages):

  ( field 'prev_comm' ret=0x7f7c31f65110, raw_size=68 )  ( field 'prev_pid' ret=0x7f7c23b1bed0, raw_size=68 )  ( field 'prev_prio' ret=0x7f7c239c0030, raw_size=68 )  ( field 'prev_state' ret=0x7f7c239c0250, raw_size=68 ) time 14771421785867 prev_comm= prev_pid=1919907691 prev_prio=796026219 prev_state=0x303a32313175 ==&gt;
  ( XXX '��' len=16, raw_size=68)  ( field 'next_comm' ret=(nil), raw_size=68 ) Traceback (most recent call last):
   File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 51, in &lt;module&gt;
     main()
   File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 46, in main
     event.next_comm,
     ^^^^^^^^^^^^^^^
  AttributeError: 'perf.sample_event' object has no attribute 'next_comm'

When event.next_comm was asked for, the PyUnicode_FromString() python
API would fail and that tracepoint field wouldn't be available, stopping
the tools/perf/python/tracepoint.py test tool.

But, since we already do a copy of the whole event in pyrf_event__new,
just use it and while at it remove what was done in in e8968e654191390a
("perf python: Fix pyrf_evlist__read_on_cpu event consuming") because we
don't really need to wait for parsing the sample before declaring the
event as consumed.

This copy is questionable as is now, as it limits the maximum event +
sample_type and tracepoint payload to sizeof(union perf_event), this all
has been "working" because 'struct perf_event_mmap2', the largest entry
in 'union perf_event' is:

  $ pahole -C perf_event ~/bin/perf | grep mmap2
	struct perf_record_mmap2   mmap2;              /*     0  4168 */
  $

Fixes: bae57e3825a3dded ("perf python: Add support to resolve tracepoint fields")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20250312203141.285263-6-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f3fed3ae34d606819d87a63d970cc3092a5be7ab ]

When processing tracepoints the perf python binding was parsing the
event before calling perf_mmap__consume(&amp;md-&gt;core) in
pyrf_evlist__read_on_cpu().

But part of this event parsing was to set the perf_sample-&gt;raw_data
pointer to the payload of the event, which then could be overwritten by
other event before tracepoint fields were asked for via event.prev_comm
in a python program, for instance.

This also happened with other fields, but strings were were problems
were surfacing, as there is UTF-8 validation for the potentially garbled
data.

This ended up showing up as (with some added debugging messages):

  ( field 'prev_comm' ret=0x7f7c31f65110, raw_size=68 )  ( field 'prev_pid' ret=0x7f7c23b1bed0, raw_size=68 )  ( field 'prev_prio' ret=0x7f7c239c0030, raw_size=68 )  ( field 'prev_state' ret=0x7f7c239c0250, raw_size=68 ) time 14771421785867 prev_comm= prev_pid=1919907691 prev_prio=796026219 prev_state=0x303a32313175 ==&gt;
  ( XXX '��' len=16, raw_size=68)  ( field 'next_comm' ret=(nil), raw_size=68 ) Traceback (most recent call last):
   File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 51, in &lt;module&gt;
     main()
   File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 46, in main
     event.next_comm,
     ^^^^^^^^^^^^^^^
  AttributeError: 'perf.sample_event' object has no attribute 'next_comm'

When event.next_comm was asked for, the PyUnicode_FromString() python
API would fail and that tracepoint field wouldn't be available, stopping
the tools/perf/python/tracepoint.py test tool.

But, since we already do a copy of the whole event in pyrf_event__new,
just use it and while at it remove what was done in in e8968e654191390a
("perf python: Fix pyrf_evlist__read_on_cpu event consuming") because we
don't really need to wait for parsing the sample before declaring the
event as consumed.

This copy is questionable as is now, as it limits the maximum event +
sample_type and tracepoint payload to sizeof(union perf_event), this all
has been "working" because 'struct perf_event_mmap2', the largest entry
in 'union perf_event' is:

  $ pahole -C perf_event ~/bin/perf | grep mmap2
	struct perf_record_mmap2   mmap2;              /*     0  4168 */
  $

Fixes: bae57e3825a3dded ("perf python: Add support to resolve tracepoint fields")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20250312203141.285263-6-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf python: Decrement the refcount of just created event on failure</title>
<updated>2025-04-10T12:33:37+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2025-03-12T20:31:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5cf553ae38377facad7711c1ce69066fbbc8072c'/>
<id>5cf553ae38377facad7711c1ce69066fbbc8072c</id>
<content type='text'>
[ Upstream commit 3de5a2bf5b4847f7a59a184568f969f8fe05d57f ]

To avoid a leak if we have the python object but then something happens
and we need to return the operation, decrement the offset of the newly
created object.

Fixes: 377f698db12150a1 ("perf python: Add struct evsel into struct pyrf_event")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20250312203141.285263-5-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3de5a2bf5b4847f7a59a184568f969f8fe05d57f ]

To avoid a leak if we have the python object but then something happens
and we need to return the operation, decrement the offset of the newly
created object.

Fixes: 377f698db12150a1 ("perf python: Add struct evsel into struct pyrf_event")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20250312203141.285263-5-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf python: Fixup description of sample.id event member</title>
<updated>2025-04-10T12:33:36+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2025-03-12T20:31:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e95f1c106d3d37b5f36d528ac57df1871bf95491'/>
<id>e95f1c106d3d37b5f36d528ac57df1871bf95491</id>
<content type='text'>
[ Upstream commit 1376c195e8ad327bb9f2d32e0acc5ac39e7cb30a ]

Some old cut'n'paste error, its "ip", so the description should be
"event ip", not "event type".

Fixes: 877108e42b1b9ba6 ("perf tools: Initial python binding")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20250312203141.285263-2-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 1376c195e8ad327bb9f2d32e0acc5ac39e7cb30a ]

Some old cut'n'paste error, its "ip", so the description should be
"event ip", not "event type".

Fixes: 877108e42b1b9ba6 ("perf tools: Initial python binding")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20250312203141.285263-2-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf units: Fix insufficient array space</title>
<updated>2025-04-10T12:33:36+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2025-03-10T19:45:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=314f8fb911e85757f8553e8f1759eada5629dbfe'/>
<id>314f8fb911e85757f8553e8f1759eada5629dbfe</id>
<content type='text'>
[ Upstream commit cf67629f7f637fb988228abdb3aae46d0c1748fe ]

No need to specify the array size, let the compiler figure that out.

This addresses this compiler warning that was noticed while build
testing on fedora rawhide:

  31    15.81 fedora:rawhide                : FAIL gcc version 15.0.1 20250225 (Red Hat 15.0.1-0) (GCC)
    util/units.c: In function 'unit_number__scnprintf':
    util/units.c:67:24: error: initializer-string for array of 'char' is too long [-Werror=unterminated-string-initialization]
       67 |         char unit[4] = "BKMG";
          |                        ^~~~~~
    cc1: all warnings being treated as errors

Fixes: 9808143ba2e54818 ("perf tools: Add unit_number__scnprintf function")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: https://lore.kernel.org/r/20250310194534.265487-3-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit cf67629f7f637fb988228abdb3aae46d0c1748fe ]

No need to specify the array size, let the compiler figure that out.

This addresses this compiler warning that was noticed while build
testing on fedora rawhide:

  31    15.81 fedora:rawhide                : FAIL gcc version 15.0.1 20250225 (Red Hat 15.0.1-0) (GCC)
    util/units.c: In function 'unit_number__scnprintf':
    util/units.c:67:24: error: initializer-string for array of 'char' is too long [-Werror=unterminated-string-initialization]
       67 |         char unit[4] = "BKMG";
          |                        ^~~~~~
    cc1: all warnings being treated as errors

Fixes: 9808143ba2e54818 ("perf tools: Add unit_number__scnprintf function")
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: https://lore.kernel.org/r/20250310194534.265487-3-acme@kernel.org
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf evlist: Add success path to evlist__create_syswide_maps</title>
<updated>2025-04-10T12:33:36+00:00</updated>
<author>
<name>Ian Rogers</name>
<email>irogers@google.com</email>
</author>
<published>2025-02-28T22:22:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b303aff1c5e7b467fec25149e03124f512e99589'/>
<id>b303aff1c5e7b467fec25149e03124f512e99589</id>
<content type='text'>
[ Upstream commit fe0ce8a9d85a48642880c9b78944cb0d23e779c5 ]

Over various refactorings evlist__create_syswide_maps has been made to
only ever return with -ENOMEM. Fix this so that when
perf_evlist__set_maps is successfully called, 0 is returned.

Reviewed-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Reviewed-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: https://lore.kernel.org/r/20250228222308.626803-3-irogers@google.com
Fixes: 8c0498b6891d7ca5 ("perf evlist: Fix create_syswide_maps() not propagating maps")
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fe0ce8a9d85a48642880c9b78944cb0d23e779c5 ]

Over various refactorings evlist__create_syswide_maps has been made to
only ever return with -ENOMEM. Fix this so that when
perf_evlist__set_maps is successfully called, 0 is returned.

Reviewed-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Reviewed-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: https://lore.kernel.org/r/20250228222308.626803-3-irogers@google.com
Fixes: 8c0498b6891d7ca5 ("perf evlist: Fix create_syswide_maps() not propagating maps")
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf trace: Avoid garbage when not printing a syscall's arguments</title>
<updated>2024-12-14T18:53:46+00:00</updated>
<author>
<name>Benjamin Peterson</name>
<email>benjamin@engflow.com</email>
</author>
<published>2024-11-07T23:21:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=57ef7705a3e485d9b14bfd6a3c1cd4e4b5a3dadf'/>
<id>57ef7705a3e485d9b14bfd6a3c1cd4e4b5a3dadf</id>
<content type='text'>
[ Upstream commit 1302e352b26f34991b619b5d0b621b76d20a3883 ]

syscall__scnprintf_args may not place anything in the output buffer
(e.g., because the arguments are all zero). If that happened in
trace__fprintf_sys_enter, its fprintf would receive an unitialized
buffer leading to garbage output.

Fix the problem by passing the (possibly zero) bounds of the argument
buffer to the output fprintf.

Fixes: a98392bb1e169a04 ("perf trace: Use beautifiers on syscalls:sys_enter_ handlers")
Signed-off-by: Benjamin Peterson &lt;benjamin@engflow.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241107232128.108981-2-benjamin@engflow.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 1302e352b26f34991b619b5d0b621b76d20a3883 ]

syscall__scnprintf_args may not place anything in the output buffer
(e.g., because the arguments are all zero). If that happened in
trace__fprintf_sys_enter, its fprintf would receive an unitialized
buffer leading to garbage output.

Fix the problem by passing the (possibly zero) bounds of the argument
buffer to the output fprintf.

Fixes: a98392bb1e169a04 ("perf trace: Use beautifiers on syscalls:sys_enter_ handlers")
Signed-off-by: Benjamin Peterson &lt;benjamin@engflow.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241107232128.108981-2-benjamin@engflow.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf trace: Do not lose last events in a race</title>
<updated>2024-12-14T18:53:46+00:00</updated>
<author>
<name>Benjamin Peterson</name>
<email>benjamin@engflow.com</email>
</author>
<published>2024-11-07T23:21:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8b601e05c43b7226fe595018c0d22c86d7f1cd92'/>
<id>8b601e05c43b7226fe595018c0d22c86d7f1cd92</id>
<content type='text'>
[ Upstream commit 3fd7c36973a250e17a4ee305a31545a9426021f4 ]

If a perf trace event selector specifies a maximum number of events to output
(i.e., "/nr=N/" syntax), the event printing handler, trace__event_handler,
disables the event selector after the maximum number events are
printed.

Furthermore, trace__event_handler checked if the event selector was
disabled before doing any work. This avoided exceeding the maximum
number of events to print if more events were in the buffer before the
selector was disabled.

However, the event selector can be disabled for reasons other than
exceeding the maximum number of events. In particular, when the traced
subprocess exits, the main loop disables all event selectors. This meant
the last events of a traced subprocess might be lost to the printing
handler's short-circuiting logic.

This nondeterministic problem could be seen by running the following many times:

  $ perf trace -e syscalls:sys_enter_exit_group true

trace__event_handler should simply check for exceeding the maximum number of
events to print rather than the state of the event selector.

Fixes: a9c5e6c1e9bff42c ("perf trace: Introduce per-event maximum number of events property")
Signed-off-by: Benjamin Peterson &lt;benjamin@engflow.com&gt;
Tested-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241107232128.108981-1-benjamin@engflow.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3fd7c36973a250e17a4ee305a31545a9426021f4 ]

If a perf trace event selector specifies a maximum number of events to output
(i.e., "/nr=N/" syntax), the event printing handler, trace__event_handler,
disables the event selector after the maximum number events are
printed.

Furthermore, trace__event_handler checked if the event selector was
disabled before doing any work. This avoided exceeding the maximum
number of events to print if more events were in the buffer before the
selector was disabled.

However, the event selector can be disabled for reasons other than
exceeding the maximum number of events. In particular, when the traced
subprocess exits, the main loop disables all event selectors. This meant
the last events of a traced subprocess might be lost to the printing
handler's short-circuiting logic.

This nondeterministic problem could be seen by running the following many times:

  $ perf trace -e syscalls:sys_enter_exit_group true

trace__event_handler should simply check for exceeding the maximum number of
events to print rather than the state of the event selector.

Fixes: a9c5e6c1e9bff42c ("perf trace: Introduce per-event maximum number of events property")
Signed-off-by: Benjamin Peterson &lt;benjamin@engflow.com&gt;
Tested-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241107232128.108981-1-benjamin@engflow.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf trace: avoid garbage when not printing a trace event's arguments</title>
<updated>2024-12-14T18:53:46+00:00</updated>
<author>
<name>Benjamin Peterson</name>
<email>benjamin@engflow.com</email>
</author>
<published>2024-11-03T20:48:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6ac0ea38a85b61d11ebb0f55579205ff85aeacc7'/>
<id>6ac0ea38a85b61d11ebb0f55579205ff85aeacc7</id>
<content type='text'>
[ Upstream commit 5fb8e56542a3cf469fdf25d77f50e21cbff3ae7e ]

trace__fprintf_tp_fields may not print any tracepoint arguments. E.g., if the
argument values are all zero. Previously, this would result in a totally
uninitialized buffer being passed to fprintf, which could lead to garbage on the
console. Fix the problem by passing the number of initialized bytes fprintf.

Fixes: f11b2803bb88 ("perf trace: Allow choosing how to augment the tracepoint arguments")
Signed-off-by: Benjamin Peterson &lt;benjamin@engflow.com&gt;
Tested-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: https://lore.kernel.org/r/20241103204816.7834-1-benjamin@engflow.com
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5fb8e56542a3cf469fdf25d77f50e21cbff3ae7e ]

trace__fprintf_tp_fields may not print any tracepoint arguments. E.g., if the
argument values are all zero. Previously, this would result in a totally
uninitialized buffer being passed to fprintf, which could lead to garbage on the
console. Fix the problem by passing the number of initialized bytes fprintf.

Fixes: f11b2803bb88 ("perf trace: Allow choosing how to augment the tracepoint arguments")
Signed-off-by: Benjamin Peterson &lt;benjamin@engflow.com&gt;
Tested-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: https://lore.kernel.org/r/20241103204816.7834-1-benjamin@engflow.com
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
