<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/kernel/trace, branch v4.19.240</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.19.240</id>
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<updated>2022-04-27T11:39:42Z</updated>
<entry>
<title>tracing: Dump stacktrace trigger to the corresponding instance</title>
<updated>2022-04-27T11:39:42Z</updated>
<author>
<name>Daniel Bristot de Oliveira</name>
<email>bristot@kernel.org</email>
</author>
<published>2022-02-20T22:49:57Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2e40a481bc3655e151f75362d6de17ac26fc9e14'/>
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<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>
</entry>
<entry>
<title>tracing: Ensure trace buffer is at least 4096 bytes large</title>
<updated>2022-03-16T12:20:27Z</updated>
<author>
<name>Sven Schnelle</name>
<email>svens@linux.ibm.com</email>
</author>
<published>2022-02-14T13:44:56Z</published>
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<content type='text'>
[ Upstream commit 7acf3a127bb7c65ff39099afd78960e77b2ca5de ]

Booting the kernel with 'trace_buf_size=1' give a warning at
boot during the ftrace selftests:

[    0.892809] Running postponed tracer tests:
[    0.892893] Testing tracer function:
[    0.901899] Callback from call_rcu_tasks_trace() invoked.
[    0.983829] Callback from call_rcu_tasks_rude() invoked.
[    1.072003] .. bad ring buffer .. corrupted trace buffer ..
[    1.091944] Callback from call_rcu_tasks() invoked.
[    1.097695] PASSED
[    1.097701] Testing dynamic ftrace: .. filter failed count=0 ..FAILED!
[    1.353474] ------------[ cut here ]------------
[    1.353478] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1951 run_tracer_selftest+0x13c/0x1b0

Therefore enforce a minimum of 4096 bytes to make the selftest pass.

Link: https://lkml.kernel.org/r/20220214134456.1751749-1-svens@linux.ibm.com

Signed-off-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>tracing/histogram: Fix sorting on old "cpu" value</title>
<updated>2022-03-08T18:04:10Z</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-03-02T03:29:04Z</published>
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<id>urn:sha1:44a99561718d5e1d8471162c0f3f842f8e63c248</id>
<content type='text'>
commit 1d1898f65616c4601208963c3376c1d828cbf2c7 upstream.

When trying to add a histogram against an event with the "cpu" field, it
was impossible due to "cpu" being a keyword to key off of the running CPU.
So to fix this, it was changed to "common_cpu" to match the other generic
fields (like "common_pid"). But since some scripts used "cpu" for keying
off of the CPU (for events that did not have "cpu" as a field, which is
most of them), a backward compatibility trick was added such that if "cpu"
was used as a key, and the event did not have "cpu" as a field name, then
it would fallback and switch over to "common_cpu".

This fix has a couple of subtle bugs. One was that when switching over to
"common_cpu", it did not change the field name, it just set a flag. But
the code still found a "cpu" field. The "cpu" field is used for filtering
and is returned when the event does not have a "cpu" field.

This was found by:

  # cd /sys/kernel/tracing
  # echo hist:key=cpu,pid:sort=cpu &gt; events/sched/sched_wakeup/trigger
  # cat events/sched/sched_wakeup/hist

Which showed the histogram unsorted:

{ cpu:         19, pid:       1175 } hitcount:          1
{ cpu:          6, pid:        239 } hitcount:          2
{ cpu:         23, pid:       1186 } hitcount:         14
{ cpu:         12, pid:        249 } hitcount:          2
{ cpu:          3, pid:        994 } hitcount:          5

Instead of hard coding the "cpu" checks, take advantage of the fact that
trace_event_field_field() returns a special field for "cpu" and "CPU" if
the event does not have "cpu" as a field. This special field has the
"filter_type" of "FILTER_CPU". Check that to test if the returned field is
of the CPU type instead of doing the string compare.

Also, fix the sorting bug by testing for the hist_field flag of
HIST_FIELD_FL_CPU when setting up the sort routine. Otherwise it will use
the special CPU field to know what compare routine to use, and since that
special field does not have a size, it returns tracing_map_cmp_none.

Cc: stable@vger.kernel.org
Fixes: 1e3bac71c505 ("tracing/histogram: Rename "cpu" to "common_cpu"")
Reported-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>
</entry>
<entry>
<title>tracing: Have traceon and traceoff trigger honor the instance</title>
<updated>2022-03-02T10:38:15Z</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-02-24T03:38:37Z</published>
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<id>urn:sha1:e6a2e27cc946567728374b881196ee4eace9683f</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>
</entry>
<entry>
<title>tracing: Fix tp_printk option related with tp_printk_stop_on_boot</title>
<updated>2022-02-23T10:58:42Z</updated>
<author>
<name>JaeSang Yoo</name>
<email>js.yoo.5b@gmail.com</email>
</author>
<published>2022-02-08T19:54:22Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8f8c9e71e192823e4d76fdc53b4391642291bafc'/>
<id>urn:sha1:8f8c9e71e192823e4d76fdc53b4391642291bafc</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>
</entry>
<entry>
<title>tracing: Tag trace_percpu_buffer as a percpu pointer</title>
<updated>2022-01-11T12:58:49Z</updated>
<author>
<name>Naveen N. Rao</name>
<email>naveen.n.rao@linux.vnet.ibm.com</email>
</author>
<published>2021-12-23T10:34:39Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=e9c3f28e2b9eaff371db65e4bd7ee170616147b4'/>
<id>urn:sha1:e9c3f28e2b9eaff371db65e4bd7ee170616147b4</id>
<content type='text'>
commit f28439db470cca8b6b082239314e9fd10bd39034 upstream.

Tag trace_percpu_buffer as a percpu pointer to resolve warnings
reported by sparse:
  /linux/kernel/trace/trace.c:3218:46: warning: incorrect type in initializer (different address spaces)
  /linux/kernel/trace/trace.c:3218:46:    expected void const [noderef] __percpu *__vpp_verify
  /linux/kernel/trace/trace.c:3218:46:    got struct trace_buffer_struct *
  /linux/kernel/trace/trace.c:3234:9: warning: incorrect type in initializer (different address spaces)
  /linux/kernel/trace/trace.c:3234:9:    expected void const [noderef] __percpu *__vpp_verify
  /linux/kernel/trace/trace.c:3234:9:    got int *

Link: https://lkml.kernel.org/r/ebabd3f23101d89cb75671b68b6f819f5edc830b.1640255304.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Fixes: 07d777fe8c398 ("tracing: Add percpu buffers for trace_printk()")
Signed-off-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tracing: Fix check for trace_percpu_buffer validity in get_trace_buf()</title>
<updated>2022-01-11T12:58:49Z</updated>
<author>
<name>Naveen N. Rao</name>
<email>naveen.n.rao@linux.vnet.ibm.com</email>
</author>
<published>2021-12-23T10:34:38Z</published>
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<id>urn:sha1:24bb91f9536f79a13f85cfaae59be41fc8d9380d</id>
<content type='text'>
commit 823e670f7ed616d0ce993075c8afe0217885f79d upstream.

With the new osnoise tracer, we are seeing the below splat:
    Kernel attempted to read user page (c7d880000) - exploit attempt? (uid: 0)
    BUG: Unable to handle kernel data access on read at 0xc7d880000
    Faulting instruction address: 0xc0000000002ffa10
    Oops: Kernel access of bad area, sig: 11 [#1]
    LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
    ...
    NIP [c0000000002ffa10] __trace_array_vprintk.part.0+0x70/0x2f0
    LR [c0000000002ff9fc] __trace_array_vprintk.part.0+0x5c/0x2f0
    Call Trace:
    [c0000008bdd73b80] [c0000000001c49cc] put_prev_task_fair+0x3c/0x60 (unreliable)
    [c0000008bdd73be0] [c000000000301430] trace_array_printk_buf+0x70/0x90
    [c0000008bdd73c00] [c0000000003178b0] trace_sched_switch_callback+0x250/0x290
    [c0000008bdd73c90] [c000000000e70d60] __schedule+0x410/0x710
    [c0000008bdd73d40] [c000000000e710c0] schedule+0x60/0x130
    [c0000008bdd73d70] [c000000000030614] interrupt_exit_user_prepare_main+0x264/0x270
    [c0000008bdd73de0] [c000000000030a70] syscall_exit_prepare+0x150/0x180
    [c0000008bdd73e10] [c00000000000c174] system_call_vectored_common+0xf4/0x278

osnoise tracer on ppc64le is triggering osnoise_taint() for negative
duration in get_int_safe_duration() called from
trace_sched_switch_callback()-&gt;thread_exit().

The problem though is that the check for a valid trace_percpu_buffer is
incorrect in get_trace_buf(). The check is being done after calculating
the pointer for the current cpu, rather than on the main percpu pointer.
Fix the check to be against trace_percpu_buffer.

Link: https://lkml.kernel.org/r/a920e4272e0b0635cf20c444707cbce1b2c8973d.1640255304.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: e2ace001176dc9 ("tracing: Choose static tp_printk buffer by explicit nesting count")
Signed-off-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tracing: Fix a kmemleak false positive in tracing_map</title>
<updated>2021-12-22T08:19:00Z</updated>
<author>
<name>Chen Jun</name>
<email>chenjun102@huawei.com</email>
</author>
<published>2021-11-24T14:08:01Z</published>
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<id>urn:sha1:a501f2500fe2e54fc2b0b013b94e94dc97b73678</id>
<content type='text'>
[ Upstream commit f25667e5980a4333729cac3101e5de1bb851f71a ]

Doing the command:
  echo 'hist:key=common_pid.execname,common_timestamp' &gt; /sys/kernel/debug/tracing/events/xxx/trigger

Triggers many kmemleak reports:

unreferenced object 0xffff0000c7ea4980 (size 128):
  comm "bash", pid 338, jiffies 4294912626 (age 9339.324s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [&lt;00000000f3469921&gt;] kmem_cache_alloc_trace+0x4c0/0x6f0
    [&lt;0000000054ca40c3&gt;] hist_trigger_elt_data_alloc+0x140/0x178
    [&lt;00000000633bd154&gt;] tracing_map_init+0x1f8/0x268
    [&lt;000000007e814ab9&gt;] event_hist_trigger_func+0xca0/0x1ad0
    [&lt;00000000bf8520ed&gt;] trigger_process_regex+0xd4/0x128
    [&lt;00000000f549355a&gt;] event_trigger_write+0x7c/0x120
    [&lt;00000000b80f898d&gt;] vfs_write+0xc4/0x380
    [&lt;00000000823e1055&gt;] ksys_write+0x74/0xf8
    [&lt;000000008a9374aa&gt;] __arm64_sys_write+0x24/0x30
    [&lt;0000000087124017&gt;] do_el0_svc+0x88/0x1c0
    [&lt;00000000efd0dcd1&gt;] el0_svc+0x1c/0x28
    [&lt;00000000dbfba9b3&gt;] el0_sync_handler+0x88/0xc0
    [&lt;00000000e7399680&gt;] el0_sync+0x148/0x180
unreferenced object 0xffff0000c7ea4980 (size 128):
  comm "bash", pid 338, jiffies 4294912626 (age 9339.324s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [&lt;00000000f3469921&gt;] kmem_cache_alloc_trace+0x4c0/0x6f0
    [&lt;0000000054ca40c3&gt;] hist_trigger_elt_data_alloc+0x140/0x178
    [&lt;00000000633bd154&gt;] tracing_map_init+0x1f8/0x268
    [&lt;000000007e814ab9&gt;] event_hist_trigger_func+0xca0/0x1ad0
    [&lt;00000000bf8520ed&gt;] trigger_process_regex+0xd4/0x128
    [&lt;00000000f549355a&gt;] event_trigger_write+0x7c/0x120
    [&lt;00000000b80f898d&gt;] vfs_write+0xc4/0x380
    [&lt;00000000823e1055&gt;] ksys_write+0x74/0xf8
    [&lt;000000008a9374aa&gt;] __arm64_sys_write+0x24/0x30
    [&lt;0000000087124017&gt;] do_el0_svc+0x88/0x1c0
    [&lt;00000000efd0dcd1&gt;] el0_svc+0x1c/0x28
    [&lt;00000000dbfba9b3&gt;] el0_sync_handler+0x88/0xc0
    [&lt;00000000e7399680&gt;] el0_sync+0x148/0x180

The reason is elts-&gt;pages[i] is alloced by get_zeroed_page.
and kmemleak will not scan the area alloced by get_zeroed_page.
The address stored in elts-&gt;pages will be regarded as leaked.

That is, the elts-&gt;pages[i] will have pointers loaded onto it as well, and
without telling kmemleak about it, those pointers will look like memory
without a reference.

To fix this, call kmemleak_alloc to tell kmemleak to scan elts-&gt;pages[i]

Link: https://lkml.kernel.org/r/20211124140801.87121-1-chenjun102@huawei.com

Signed-off-by: Chen Jun &lt;chenjun102@huawei.com&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>tracing: Check pid filtering when creating events</title>
<updated>2021-12-01T08:27:43Z</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2021-11-26T18:35:26Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2692931d92d83afaa636703e95203d53629ca7c1'/>
<id>urn:sha1:2692931d92d83afaa636703e95203d53629ca7c1</id>
<content type='text'>
commit 6cb206508b621a9a0a2c35b60540e399225c8243 upstream.

When pid filtering is activated in an instance, all of the events trace
files for that instance has the PID_FILTER flag set. This determines
whether or not pid filtering needs to be done on the event, otherwise the
event is executed as normal.

If pid filtering is enabled when an event is created (via a dynamic event
or modules), its flag is not updated to reflect the current state, and the
events are not filtered properly.

Cc: stable@vger.kernel.org
Fixes: 3fdaf80f4a836 ("tracing: Implement event pid filtering")
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tracing: Fix pid filtering when triggers are attached</title>
<updated>2021-12-01T08:27:39Z</updated>
<author>
<name>Steven Rostedt (VMware)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2021-11-26T22:34:42Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=bbaf4fe5ec34e7931af9a03a60b4071c2bc01ae0'/>
<id>urn:sha1:bbaf4fe5ec34e7931af9a03a60b4071c2bc01ae0</id>
<content type='text'>
commit a55f224ff5f238013de8762c4287117e47b86e22 upstream.

If a event is filtered by pid and a trigger that requires processing of
the event to happen is a attached to the event, the discard portion does
not take the pid filtering into account, and the event will then be
recorded when it should not have been.

Cc: stable@vger.kernel.org
Fixes: 3fdaf80f4a836 ("tracing: Implement event pid filtering")
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
