<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux/trace_events.h, branch v6.5.11</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.5.11</id>
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<updated>2023-09-23T09:14:36Z</updated>
<entry>
<title>tracing/synthetic: Fix order of struct trace_dynamic_info</title>
<updated>2023-09-23T09:14:36Z</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2023-09-08T20:39:29Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=0555c44a95d60536e5e5bfd654b8281981677b44'/>
<id>urn:sha1:0555c44a95d60536e5e5bfd654b8281981677b44</id>
<content type='text'>
commit fc52a64416b010c8324e2cb50070faae868521c1 upstream.

To make handling BIG and LITTLE endian better the offset/len of dynamic
fields of the synthetic events was changed into a structure of:

 struct trace_dynamic_info {
 #ifdef CONFIG_CPU_BIG_ENDIAN
	u16	offset;
	u16	len;
 #else
	u16	len;
	u16	offset;
 #endif
 };

to replace the manual changes of:

 data_offset = offset &amp; 0xffff;
 data_offest = len &lt;&lt; 16;

But if you look closely, the above is:

  &lt;len&gt; &lt;&lt; 16 | offset

Which in little endian would be in memory:

 offset_lo offset_hi len_lo len_hi

and in big endian:

 len_hi len_lo offset_hi offset_lo

Which if broken into a structure would be:

 struct trace_dynamic_info {
 #ifdef CONFIG_CPU_BIG_ENDIAN
	u16	len;
	u16	offset;
 #else
	u16	offset;
	u16	len;
 #endif
 };

Which is the opposite of what was defined.

Fix this and just to be safe also add "__packed".

Link: https://lore.kernel.org/all/20230908154417.5172e343@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20230908163929.2c25f3dc@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Tested-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Fixes: ddeea494a16f3 ("tracing/synthetic: Use union instead of casts")
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>bpf: Clear the probe_addr for uprobe</title>
<updated>2023-09-13T07:53:02Z</updated>
<author>
<name>Yafang Shao</name>
<email>laoar.shao@gmail.com</email>
</author>
<published>2023-07-09T02:56:25Z</published>
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<id>urn:sha1:ee55daf6f28519f188fbc719a1e76200239726ad</id>
<content type='text'>
[ Upstream commit 5125e757e62f6c1d5478db4c2b61a744060ddf3f ]

To avoid returning uninitialized or random values when querying the file
descriptor (fd) and accessing probe_addr, it is necessary to clear the
variable prior to its use.

Fixes: 41bdc4b40ed6 ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY")
Signed-off-by: Yafang Shao &lt;laoar.shao@gmail.com&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/r/20230709025630.3735-6-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>tracing/synthetic: Use union instead of casts</title>
<updated>2023-08-16T20:33:27Z</updated>
<author>
<name>Sven Schnelle</name>
<email>svens@linux.ibm.com</email>
</author>
<published>2023-08-16T15:49:26Z</published>
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<id>urn:sha1:ddeea494a16f32522bce16ee65f191d05d4b8282</id>
<content type='text'>
The current code uses a lot of casts to access the fields member in struct
synth_trace_events with different sizes.  This makes the code hard to
read, and had already introduced an endianness bug. Use a union and struct
instead.

Link: https://lkml.kernel.org/r/20230816154928.4171614-2-svens@linux.ibm.com

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Fixes: 00cf3d672a9dd ("tracing: Allow synthetic events to pass around stacktraces")
Signed-off-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>tracing/probes: Add fprobe events for tracing function entry and exit.</title>
<updated>2023-06-06T12:39:55Z</updated>
<author>
<name>Masami Hiramatsu (Google)</name>
<email>mhiramat@kernel.org</email>
</author>
<published>2023-06-06T12:39:55Z</published>
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<id>urn:sha1:334e5519c3757019cc591d4539d5aca199bdb114</id>
<content type='text'>
Add fprobe events for tracing function entry and exit instead of kprobe
events. With this change, we can continue to trace function entry/exit
even if the CONFIG_KPROBES_ON_FTRACE is not available. Since
CONFIG_KPROBES_ON_FTRACE requires the CONFIG_DYNAMIC_FTRACE_WITH_REGS,
it is not available if the architecture only supports
CONFIG_DYNAMIC_FTRACE_WITH_ARGS. And that means kprobe events can not
probe function entry/exit effectively on such architecture.
But this can be solved if the dynamic events supports fprobe events.

The fprobe event is a new dynamic events which is only for the function
(symbol) entry and exit. This event accepts non register fetch arguments
so that user can trace the function arguments and return values.

The fprobe events syntax is here;

 f[:[GRP/][EVENT]] FUNCTION [FETCHARGS]
 f[MAXACTIVE][:[GRP/][EVENT]] FUNCTION%return [FETCHARGS]

E.g.

 # echo 'f vfs_read $arg1'  &gt;&gt; dynamic_events
 # echo 'f vfs_read%return $retval'  &gt;&gt; dynamic_events
 # cat dynamic_events
 f:fprobes/vfs_read__entry vfs_read arg1=$arg1
 f:fprobes/vfs_read__exit vfs_read%return arg1=$retval
 # echo 1 &gt; events/fprobes/enable
 # head -n 20 trace | tail
 #           TASK-PID     CPU#  |||||  TIMESTAMP  FUNCTION
 #              | |         |   |||||     |         |
              sh-142     [005] ...1.   448.386420: vfs_read__entry: (vfs_read+0x4/0x340) arg1=0xffff888007f7c540
              sh-142     [005] .....   448.386436: vfs_read__exit: (ksys_read+0x75/0x100 &lt;- vfs_read) arg1=0x1
              sh-142     [005] ...1.   448.386451: vfs_read__entry: (vfs_read+0x4/0x340) arg1=0xffff888007f7c540
              sh-142     [005] .....   448.386458: vfs_read__exit: (ksys_read+0x75/0x100 &lt;- vfs_read) arg1=0x1
              sh-142     [005] ...1.   448.386469: vfs_read__entry: (vfs_read+0x4/0x340) arg1=0xffff888007f7c540
              sh-142     [005] .....   448.386476: vfs_read__exit: (ksys_read+0x75/0x100 &lt;- vfs_read) arg1=0x1
              sh-142     [005] ...1.   448.602073: vfs_read__entry: (vfs_read+0x4/0x340) arg1=0xffff888007f7c540
              sh-142     [005] .....   448.602089: vfs_read__exit: (ksys_read+0x75/0x100 &lt;- vfs_read) arg1=0x1

Link: https://lore.kernel.org/all/168507469754.913472.6112857614708350210.stgit@mhiramat.roam.corp.google.com/

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Link: https://lore.kernel.org/all/202302011530.7vm4O8Ro-lkp@intel.com/
Signed-off-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
</content>
</entry>
<entry>
<title>tracing: Rename stacktrace field to common_stacktrace</title>
<updated>2023-05-24T03:38:23Z</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2023-05-24T03:09:13Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4b512860bdbdddcf41467ebd394f27cb8dfb528c'/>
<id>urn:sha1:4b512860bdbdddcf41467ebd394f27cb8dfb528c</id>
<content type='text'>
The histogram and synthetic events can use a pseudo event called
"stacktrace" that will create a stacktrace at the time of the event and
use it just like it was a normal field. We have other pseudo events such
as "common_cpu" and "common_timestamp". To stay consistent with that,
convert "stacktrace" to "common_stacktrace". As this was used in older
kernels, to keep backward compatibility, this will act just like
"common_cpu" did with "cpu". That is, "cpu" will be the same as
"common_cpu" unless the event has a "cpu" field. In which case, the
event's field is used. The same is true with "stacktrace".

Also update the documentation to reflect this change.

Link: https://lore.kernel.org/linux-trace-kernel/20230523230913.6860e28d@rorschach.local.home

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Tom Zanussi &lt;zanussi@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>tracing: Fix TASK_COMM_LEN in trace event format file</title>
<updated>2023-02-12T15:23:39Z</updated>
<author>
<name>Yafang Shao</name>
<email>laoar.shao@gmail.com</email>
</author>
<published>2023-02-12T15:13:03Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b6c7abd1c28a63ad633433d037ee15a1bc3023ba'/>
<id>urn:sha1:b6c7abd1c28a63ad633433d037ee15a1bc3023ba</id>
<content type='text'>
After commit 3087c61ed2c4 ("tools/testing/selftests/bpf: replace open-coded 16 with TASK_COMM_LEN"),
the content of the format file under
/sys/kernel/tracing/events/task/task_newtask was changed from
  field:char comm[16];    offset:12;    size:16;    signed:0;
to
  field:char comm[TASK_COMM_LEN];    offset:12;    size:16;    signed:0;

John reported that this change breaks older versions of perfetto.
Then Mathieu pointed out that this behavioral change was caused by the
use of __stringify(_len), which happens to work on macros, but not on enum
labels. And he also gave the suggestion on how to fix it:
  :One possible solution to make this more robust would be to extend
  :struct trace_event_fields with one more field that indicates the length
  :of an array as an actual integer, without storing it in its stringified
  :form in the type, and do the formatting in f_show where it belongs.

The result as follows after this change,
$ cat /sys/kernel/tracing/events/task/task_newtask/format
        field:char comm[16];    offset:12;      size:16;        signed:0;

Link: https://lore.kernel.org/lkml/Y+QaZtz55LIirsUO@google.com/
Link: https://lore.kernel.org/linux-trace-kernel/20230210155921.4610-1-laoar.shao@gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20230212151303.12353-1-laoar.shao@gmail.com

Cc: stable@vger.kernel.org
Cc: Alexei Starovoitov &lt;alexei.starovoitov@gmail.com&gt;
Cc: Kajetan Puchalski &lt;kajetan.puchalski@arm.com&gt;
CC: Qais Yousef &lt;qyousef@layalina.io&gt;
Fixes: 3087c61ed2c4 ("tools/testing/selftests/bpf: replace open-coded 16 with TASK_COMM_LEN")
Reported-by: John Stultz &lt;jstultz@google.com&gt;
Debugged-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Suggested-by: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Suggested-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Yafang Shao &lt;laoar.shao@gmail.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>tracing: Fix some checker warnings</title>
<updated>2022-12-10T18:36:05Z</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2022-12-05T10:21:52Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=bfd5a5e82d22da43afa0e2bb9fb72339aa79c6cc'/>
<id>urn:sha1:bfd5a5e82d22da43afa0e2bb9fb72339aa79c6cc</id>
<content type='text'>
Fix some checker warnings in the trace code by adding __printf attributes
to a number of trace functions and their declarations.

Changes:
========
ver #2)
 - Dropped the fix for the unconditional tracing_max_lat_fops decl[1].

Link: https://lore.kernel.org/r/20221205180617.9b9d3971cbe06ee536603523@kernel.org/ [1]
Link: https://lore.kernel.org/r/166992525941.1716618.13740663757583361463.stgit@warthog.procyon.org.uk/ # v1
Link: https://lkml.kernel.org/r/167023571258.382307.15314866482834835192.stgit@warthog.procyon.org.uk

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>tracing: Optimize event type allocation with IDA</title>
<updated>2022-11-24T00:08:31Z</updated>
<author>
<name>Zheng Yejian</name>
<email>zhengyejian1@huawei.com</email>
</author>
<published>2022-11-10T02:03:19Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=96e6122cb79616c622ae0d025eb9f981120b568d'/>
<id>urn:sha1:96e6122cb79616c622ae0d025eb9f981120b568d</id>
<content type='text'>
After commit 060fa5c83e67 ("tracing/events: reuse trace event ids after
 overflow"), trace events with dynamic type are linked up in list
'ftrace_event_list' through field 'trace_event.list'. Then when max
event type number used up, it's possible to reuse type number of some
freed one by traversing 'ftrace_event_list'.

As instead, using IDA to manage available type numbers can make codes
simpler and then the field 'trace_event.list' can be dropped.

Since 'struct trace_event' is used in static tracepoints, drop
'trace_event.list' can make vmlinux smaller. Local test with about 2000
tracepoints, vmlinux reduced about 64KB:
  before：-rwxrwxr-x 1 root root 76669448 Nov  8 17:14 vmlinux
  after： -rwxrwxr-x 1 root root 76604176 Nov  8 17:15 vmlinux

Link: https://lkml.kernel.org/r/20221110020319.1259291-1-zhengyejian1@huawei.com

Signed-off-by: Zheng Yejian &lt;zhengyejian1@huawei.com&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>tracing: Wake up ring buffer waiters on closing of the file</title>
<updated>2022-09-29T00:28:13Z</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-09-27T23:15:27Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=f3ddb74ad0790030c9592229fb14d8c451f4e9a8'/>
<id>urn:sha1:f3ddb74ad0790030c9592229fb14d8c451f4e9a8</id>
<content type='text'>
When the file that represents the ring buffer is closed, there may be
waiters waiting on more input from the ring buffer. Call
ring_buffer_wake_waiters() to wake up any waiters when the file is
closed.

Link: https://lkml.kernel.org/r/20220927231825.182416969@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice")
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
</entry>
<entry>
<title>tracing: Define the is_signed_type() macro once</title>
<updated>2022-08-29T20:29:40Z</updated>
<author>
<name>Bart Van Assche</name>
<email>bvanassche@acm.org</email>
</author>
<published>2022-08-23T19:59:25Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=dcf8e5633e2e69ad60b730ab5905608b756a032f'/>
<id>urn:sha1:dcf8e5633e2e69ad60b730ab5905608b756a032f</id>
<content type='text'>
There are two definitions of the is_signed_type() macro: one in
&lt;linux/overflow.h&gt; and a second definition in &lt;linux/trace_events.h&gt;.

As suggested by Linus, move the definition of the is_signed_type() macro
into the &lt;linux/compiler.h&gt; header file.  Change the definition of the
is_signed_type() macro to make sure that it does not trigger any sparse
warnings with future versions of sparse for bitwise types.

Link: https://lore.kernel.org/all/CAHk-=whjH6p+qzwUdx5SOVVHjS3WvzJQr6mDUwhEyTf6pJWzaQ@mail.gmail.com/
Link: https://lore.kernel.org/all/CAHk-=wjQGnVfb4jehFR0XyZikdQvCZouE96xR_nnf5kqaM5qqQ@mail.gmail.com/
Cc: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Bart Van Assche &lt;bvanassche@acm.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
