<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/trace, branch v5.15.26</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>tracing: Have traceon and traceoff trigger honor the instance</title>
<updated>2022-03-02T10:48:03+00:00</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-02-24T03:38:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9000406481a5a4d7469e021adaf19f7245609cd7'/>
<id>9000406481a5a4d7469e021adaf19f7245609cd7</id>
<content type='text'>
commit 302e9edd54985f584cfc180098f3554774126969 upstream.

If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.

Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Tested-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Reviewed-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 302e9edd54985f584cfc180098f3554774126969 upstream.

If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.

Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Tested-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Reviewed-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Dump stacktrace trigger to the corresponding instance</title>
<updated>2022-03-02T10:48:02+00:00</updated>
<author>
<name>Daniel Bristot de Oliveira</name>
<email>bristot@kernel.org</email>
</author>
<published>2022-02-20T22:49:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7e35b31e2cee9bf4eb080ff2a2acb252e6c3c14f'/>
<id>7e35b31e2cee9bf4eb080ff2a2acb252e6c3c14f</id>
<content type='text'>
commit ce33c845b030c9cf768370c951bc699470b09fa7 upstream.

The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.

Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Tested-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ce33c845b030c9cf768370c951bc699470b09fa7 upstream.

The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.

Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Tested-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Signed-off-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Fix tp_printk option related with tp_printk_stop_on_boot</title>
<updated>2022-02-23T11:03:19+00:00</updated>
<author>
<name>JaeSang Yoo</name>
<email>js.yoo.5b@gmail.com</email>
</author>
<published>2022-02-08T19:54:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eb61dbb192b1e20b2032047a3f26d0bc118e05f8'/>
<id>eb61dbb192b1e20b2032047a3f26d0bc118e05f8</id>
<content type='text'>
[ Upstream commit 3203ce39ac0b2a57a84382ec184c7d4a0bede175 ]

The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is
the same as another kernel parameter "tp_printk". If "tp_printk" setup is
called before the "tp_printk_stop_on_boot", it will override the latter
and keep it from being set.

This is similar to other kernel parameter issues, such as:
  Commit 745a600cf1a6 ("um: console: Ignore console= option")
or init/do_mounts.c:45 (setup function of "ro" kernel param)

Fix it by checking for a "_" right after the "tp_printk" and if that
exists do not process the parameter.

Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@gmail.com

Signed-off-by: JaeSang Yoo &lt;jsyoo5b@gmail.com&gt;
[ Fixed up change log and added space after if condition ]
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.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 3203ce39ac0b2a57a84382ec184c7d4a0bede175 ]

The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is
the same as another kernel parameter "tp_printk". If "tp_printk" setup is
called before the "tp_printk_stop_on_boot", it will override the latter
and keep it from being set.

This is similar to other kernel parameter issues, such as:
  Commit 745a600cf1a6 ("um: console: Ignore console= option")
or init/do_mounts.c:45 (setup function of "ro" kernel param)

Fix it by checking for a "_" right after the "tp_printk" and if that
exists do not process the parameter.

Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@gmail.com

Signed-off-by: JaeSang Yoo &lt;jsyoo5b@gmail.com&gt;
[ Fixed up change log and added space after if condition ]
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Propagate is_signed to expression</title>
<updated>2022-02-16T11:56:08+00:00</updated>
<author>
<name>Tom Zanussi</name>
<email>zanussi@kernel.org</email>
</author>
<published>2022-01-27T21:44:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=78c28fdf1685e5884963018fd3692b0ff6820805'/>
<id>78c28fdf1685e5884963018fd3692b0ff6820805</id>
<content type='text'>
commit 097f1eefedeab528cecbd35586dfe293853ffb17 upstream.

During expression parsing, a new expression field is created which
should inherit the properties of the operands, such as size and
is_signed.

is_signed propagation was missing, causing spurious errors with signed
operands.  Add it in parse_expr() and parse_unary() to fix the problem.

Link: https://lkml.kernel.org/r/f4dac08742fd7a0920bf80a73c6c44042f5eaa40.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers")
Reported-by: Yordan Karadzhov &lt;ykaradzhov@vmware.com&gt;
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215513
Signed-off-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 097f1eefedeab528cecbd35586dfe293853ffb17 upstream.

During expression parsing, a new expression field is created which
should inherit the properties of the operands, such as size and
is_signed.

is_signed propagation was missing, causing spurious errors with signed
operands.  Add it in parse_expr() and parse_unary() to fix the problem.

Link: https://lkml.kernel.org/r/f4dac08742fd7a0920bf80a73c6c44042f5eaa40.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers")
Reported-by: Yordan Karadzhov &lt;ykaradzhov@vmware.com&gt;
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215513
Signed-off-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Don't inc err_log entry count if entry allocation fails</title>
<updated>2022-02-01T16:27:00+00:00</updated>
<author>
<name>Tom Zanussi</name>
<email>zanussi@kernel.org</email>
</author>
<published>2022-01-27T21:44:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e5dcbedd48dcce9a02e035684a6765035a08da7'/>
<id>4e5dcbedd48dcce9a02e035684a6765035a08da7</id>
<content type='text'>
commit 67ab5eb71b37b55f7c5522d080a1b42823351776 upstream.

tr-&gt;n_err_log_entries should only be increased if entry allocation
succeeds.

Doing it when it fails won't cause any problems other than wasting an
entry, but should be fixed anyway.

Link: https://lkml.kernel.org/r/cad1ab28f75968db0f466925e7cba5970cec6c29.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 2f754e771b1a6 ("tracing: Don't inc err_log entry count if entry allocation fails")
Signed-off-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 67ab5eb71b37b55f7c5522d080a1b42823351776 upstream.

tr-&gt;n_err_log_entries should only be increased if entry allocation
succeeds.

Doing it when it fails won't cause any problems other than wasting an
entry, but should be fixed anyway.

Link: https://lkml.kernel.org/r/cad1ab28f75968db0f466925e7cba5970cec6c29.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 2f754e771b1a6 ("tracing: Don't inc err_log entry count if entry allocation fails")
Signed-off-by: Tom Zanussi &lt;zanussi@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing/histogram: Fix a potential memory leak for kstrdup()</title>
<updated>2022-02-01T16:27:00+00:00</updated>
<author>
<name>Xiaoke Wang</name>
<email>xkernel.wang@foxmail.com</email>
</author>
<published>2022-01-25T04:07:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e33fa4a46ee22de88a700e2e3d033da8214a5175'/>
<id>e33fa4a46ee22de88a700e2e3d033da8214a5175</id>
<content type='text'>
commit e629e7b525a179e29d53463d992bdee759c950fb upstream.

kfree() is missing on an error path to free the memory allocated by
kstrdup():

  p = param = kstrdup(data-&gt;params[i], GFP_KERNEL);

So it is better to free it via kfree(p).

Link: https://lkml.kernel.org/r/tencent_C52895FD37802832A3E5B272D05008866F0A@qq.com

Cc: stable@vger.kernel.org
Fixes: d380dcde9a07c ("tracing: Fix now invalid var_ref_vals assumption in trace action")
Signed-off-by: Xiaoke Wang &lt;xkernel.wang@foxmail.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e629e7b525a179e29d53463d992bdee759c950fb upstream.

kfree() is missing on an error path to free the memory allocated by
kstrdup():

  p = param = kstrdup(data-&gt;params[i], GFP_KERNEL);

So it is better to free it via kfree(p).

Link: https://lkml.kernel.org/r/tencent_C52895FD37802832A3E5B272D05008866F0A@qq.com

Cc: stable@vger.kernel.org
Fixes: d380dcde9a07c ("tracing: Fix now invalid var_ref_vals assumption in trace action")
Signed-off-by: Xiaoke Wang &lt;xkernel.wang@foxmail.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails</title>
<updated>2022-01-27T10:05:18+00:00</updated>
<author>
<name>Nikita Yushchenko</name>
<email>nikita.yushchenko@virtuozzo.com</email>
</author>
<published>2022-01-09T15:34:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cb77c81d347980f029e2e1ccdb80eb550d50eaf1'/>
<id>cb77c81d347980f029e2e1ccdb80eb550d50eaf1</id>
<content type='text'>
commit 0878355b51f5f26632e652c848a8e174bb02d22d upstream.

If start_per_cpu_kthreads() called from osnoise_workload_start() returns
error, event hooks are left in broken state: unhook_irq_events() called
but unhook_thread_events() and unhook_softirq_events() not called, and
trace_osnoise_callback_enabled flag not cleared.

On the next tracer enable, hooks get not installed due to
trace_osnoise_callback_enabled flag.

And on the further tracer disable an attempt to remove non-installed
hooks happened, hitting a WARN_ON_ONCE() in tracepoint_remove_func().

Fix the error path by adding the missing part of cleanup.
While at this, introduce osnoise_unhook_events() to avoid code
duplication between this error path and normal tracer disable.

Link: https://lkml.kernel.org/r/20220109153459.3701773-1-nikita.yushchenko@virtuozzo.com

Cc: stable@vger.kernel.org
Fixes: bce29ac9ce0b ("trace: Add osnoise tracer")
Acked-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Signed-off-by: Nikita Yushchenko &lt;nikita.yushchenko@virtuozzo.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0878355b51f5f26632e652c848a8e174bb02d22d upstream.

If start_per_cpu_kthreads() called from osnoise_workload_start() returns
error, event hooks are left in broken state: unhook_irq_events() called
but unhook_thread_events() and unhook_softirq_events() not called, and
trace_osnoise_callback_enabled flag not cleared.

On the next tracer enable, hooks get not installed due to
trace_osnoise_callback_enabled flag.

And on the further tracer disable an attempt to remove non-installed
hooks happened, hitting a WARN_ON_ONCE() in tracepoint_remove_func().

Fix the error path by adding the missing part of cleanup.
While at this, introduce osnoise_unhook_events() to avoid code
duplication between this error path and normal tracer disable.

Link: https://lkml.kernel.org/r/20220109153459.3701773-1-nikita.yushchenko@virtuozzo.com

Cc: stable@vger.kernel.org
Fixes: bce29ac9ce0b ("trace: Add osnoise tracer")
Acked-by: Daniel Bristot de Oliveira &lt;bristot@kernel.org&gt;
Signed-off-by: Nikita Yushchenko &lt;nikita.yushchenko@virtuozzo.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Have syscall trace events use trace_event_buffer_lock_reserve()</title>
<updated>2022-01-27T10:05:09+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-01-07T22:56:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=74c0c6483b63c528b3da39bf689e30fb4f45ae5f'/>
<id>74c0c6483b63c528b3da39bf689e30fb4f45ae5f</id>
<content type='text'>
commit 3e2a56e6f639492311e0a8533f0a7aed60816308 upstream.

Currently, the syscall trace events call trace_buffer_lock_reserve()
directly, which means that it misses out on some of the filtering
optimizations provided by the helper function
trace_event_buffer_lock_reserve(). Have the syscall trace events call that
instead, as it was missed when adding the update to use the temp buffer
when filtering.

Link: https://lkml.kernel.org/r/20220107225839.823118570@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Tom Zanussi &lt;zanussi@kernel.org&gt;
Reviewed-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Fixes: 0fc1b09ff1ff4 ("tracing: Use temp buffer when filtering events")
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3e2a56e6f639492311e0a8533f0a7aed60816308 upstream.

Currently, the syscall trace events call trace_buffer_lock_reserve()
directly, which means that it misses out on some of the filtering
optimizations provided by the helper function
trace_event_buffer_lock_reserve(). Have the syscall trace events call that
instead, as it was missed when adding the update to use the temp buffer
when filtering.

Link: https://lkml.kernel.org/r/20220107225839.823118570@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Tom Zanussi &lt;zanussi@kernel.org&gt;
Reviewed-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Fixes: 0fc1b09ff1ff4 ("tracing: Use temp buffer when filtering events")
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing/kprobes: 'nmissed' not showed correctly for kretprobe</title>
<updated>2022-01-27T10:05:09+00:00</updated>
<author>
<name>Xiangyang Zhang</name>
<email>xyz.sun.ok@gmail.com</email>
</author>
<published>2022-01-07T15:02:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=40022b3682d527908946f699df09849d366065bc'/>
<id>40022b3682d527908946f699df09849d366065bc</id>
<content type='text'>
commit dfea08a2116fe327f79d8f4d4b2cf6e0c88be11f upstream.

The 'nmissed' column of the 'kprobe_profile' file for kretprobe is
not showed correctly, kretprobe can be skipped by two reasons,
shortage of kretprobe_instance which is counted by tk-&gt;rp.nmissed,
and kprobe itself is missed by some reason, so to show the sum.

Link: https://lkml.kernel.org/r/20220107150242.5019-1-xyz.sun.ok@gmail.com

Cc: stable@vger.kernel.org
Fixes: 4a846b443b4e ("tracing/kprobes: Cleanup kprobe tracer code")
Acked-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Signed-off-by: Xiangyang Zhang &lt;xyz.sun.ok@gmail.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit dfea08a2116fe327f79d8f4d4b2cf6e0c88be11f upstream.

The 'nmissed' column of the 'kprobe_profile' file for kretprobe is
not showed correctly, kretprobe can be skipped by two reasons,
shortage of kretprobe_instance which is counted by tk-&gt;rp.nmissed,
and kprobe itself is missed by some reason, so to show the sum.

Link: https://lkml.kernel.org/r/20220107150242.5019-1-xyz.sun.ok@gmail.com

Cc: stable@vger.kernel.org
Fixes: 4a846b443b4e ("tracing/kprobes: Cleanup kprobe tracer code")
Acked-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Signed-off-by: Xiangyang Zhang &lt;xyz.sun.ok@gmail.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Remove config check to enable bpf support for branch records</title>
<updated>2022-01-27T10:03:28+00:00</updated>
<author>
<name>Kajol Jain</name>
<email>kjain@linux.ibm.com</email>
</author>
<published>2021-12-06T07:33:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=33fcd00e0aa04b1efbf3b4b09153560a0dab3176'/>
<id>33fcd00e0aa04b1efbf3b4b09153560a0dab3176</id>
<content type='text'>
[ Upstream commit db52f57211b4e45f0ebb274e2c877b211dc18591 ]

Branch data available to BPF programs can be very useful to get stack traces
out of userspace application.

Commit fff7b64355ea ("bpf: Add bpf_read_branch_records() helper") added BPF
support to capture branch records in x86. Enable this feature also for other
architectures as well by removing checks specific to x86.

If an architecture doesn't support branch records, bpf_read_branch_records()
still has appropriate checks and it will return an -EINVAL in that scenario.
Based on UAPI helper doc in include/uapi/linux/bpf.h, unsupported architectures
should return -ENOENT in such case. Hence, update the appropriate check to
return -ENOENT instead.

Selftest 'perf_branches' result on power9 machine which has the branch stacks
support:

 - Before this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:FAIL
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:FAIL
  Summary: 0/1 PASSED, 0 SKIPPED, 1 FAILED

 - After this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:OK
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:OK
  Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED

Selftest 'perf_branches' result on power9 machine which doesn't have branch
stack report:

 - After this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:SKIP
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:OK
  Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED

Fixes: fff7b64355eac ("bpf: Add bpf_read_branch_records() helper")
Suggested-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20211206073315.77432-1-kjain@linux.ibm.com
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 db52f57211b4e45f0ebb274e2c877b211dc18591 ]

Branch data available to BPF programs can be very useful to get stack traces
out of userspace application.

Commit fff7b64355ea ("bpf: Add bpf_read_branch_records() helper") added BPF
support to capture branch records in x86. Enable this feature also for other
architectures as well by removing checks specific to x86.

If an architecture doesn't support branch records, bpf_read_branch_records()
still has appropriate checks and it will return an -EINVAL in that scenario.
Based on UAPI helper doc in include/uapi/linux/bpf.h, unsupported architectures
should return -ENOENT in such case. Hence, update the appropriate check to
return -ENOENT instead.

Selftest 'perf_branches' result on power9 machine which has the branch stacks
support:

 - Before this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:FAIL
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:FAIL
  Summary: 0/1 PASSED, 0 SKIPPED, 1 FAILED

 - After this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:OK
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:OK
  Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED

Selftest 'perf_branches' result on power9 machine which doesn't have branch
stack report:

 - After this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:SKIP
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:OK
  Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED

Fixes: fff7b64355eac ("bpf: Add bpf_read_branch_records() helper")
Suggested-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20211206073315.77432-1-kjain@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
