<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/Documentation/trace, branch v6.4-rc1</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'trace-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2023-05-05T20:11:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-05-05T20:11:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e919a3f7057b5ca918dea98826b39a38eff9bebb'/>
<id>e919a3f7057b5ca918dea98826b39a38eff9bebb</id>
<content type='text'>
Pull more tracing updates from Steven Rostedt:

 - Make buffer_percent read/write.

   The buffer_percent file is how users can state how long to block on
   the tracing buffer depending on how much is in the buffer. When it
   hits the "buffer_percent" it will wake the task waiting on the
   buffer. For some reason it was set to read-only.

   This was not noticed because testing was done as root without
   SELinux, but with SELinux it will prevent even root to write to it
   without having CAP_DAC_OVERRIDE.

 - The "touched_functions" was added this merge window, but one of the
   reasons for adding it was not implemented.

   That was to show what functions were not only touched, but had either
   a direct trampoline attached to it, or a kprobe or live kernel
   patching that can "hijack" the function to run a different function.
   The point is to know if there's functions in the kernel that may not
   be behaving as the kernel code shows. This can be used for debugging.

   TODO: Add this information to kernel oops too.

* tag 'trace-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ftrace: Add MODIFIED flag to show if IPMODIFY or direct was attached
  tracing: Fix permissions for the buffer_percent file
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more tracing updates from Steven Rostedt:

 - Make buffer_percent read/write.

   The buffer_percent file is how users can state how long to block on
   the tracing buffer depending on how much is in the buffer. When it
   hits the "buffer_percent" it will wake the task waiting on the
   buffer. For some reason it was set to read-only.

   This was not noticed because testing was done as root without
   SELinux, but with SELinux it will prevent even root to write to it
   without having CAP_DAC_OVERRIDE.

 - The "touched_functions" was added this merge window, but one of the
   reasons for adding it was not implemented.

   That was to show what functions were not only touched, but had either
   a direct trampoline attached to it, or a kprobe or live kernel
   patching that can "hijack" the function to run a different function.
   The point is to know if there's functions in the kernel that may not
   be behaving as the kernel code shows. This can be used for debugging.

   TODO: Add this information to kernel oops too.

* tag 'trace-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ftrace: Add MODIFIED flag to show if IPMODIFY or direct was attached
  tracing: Fix permissions for the buffer_percent file
</pre>
</div>
</content>
</entry>
<entry>
<title>ftrace: Add MODIFIED flag to show if IPMODIFY or direct was attached</title>
<updated>2023-05-05T15:09:25+00:00</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2023-05-03T01:32:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6ce2c04fcbcaa5eb086e5142ab359be306cbc3e1'/>
<id>6ce2c04fcbcaa5eb086e5142ab359be306cbc3e1</id>
<content type='text'>
If a function had ever had IPMODIFY or DIRECT attached to it, where this
is how live kernel patching and BPF overrides work, mark them and display
an "M" in the enabled_functions and touched_functions files. This can be
used for debugging. If a function had been modified and later there's a bug
in the code related to that function, this can be used to know if the cause
is possibly from a live kernel patch or a BPF program that changed the
behavior of the code.

Also update the documentation on the enabled_functions and
touched_functions output, as it was missing direct callers and CALL_OPS.
And include this new modify attribute.

Link: https://lore.kernel.org/linux-trace-kernel/20230502213233.004e3ae4@gandalf.local.home

Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If a function had ever had IPMODIFY or DIRECT attached to it, where this
is how live kernel patching and BPF overrides work, mark them and display
an "M" in the enabled_functions and touched_functions files. This can be
used for debugging. If a function had been modified and later there's a bug
in the code related to that function, this can be used to know if the cause
is possibly from a live kernel patch or a BPF program that changed the
behavior of the code.

Also update the documentation on the enabled_functions and
touched_functions output, as it was missing direct callers and CALL_OPS.
And include this new modify attribute.

Link: https://lore.kernel.org/linux-trace-kernel/20230502213233.004e3ae4@gandalf.local.home

Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2023-04-28T22:57:53+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-28T22:57:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d579c468d7ad6e37f5b4290b0244a9a5a7d3c4bf'/>
<id>d579c468d7ad6e37f5b4290b0244a9a5a7d3c4bf</id>
<content type='text'>
Pull tracing updates from Steven Rostedt:

 - User events are finally ready!

   After lots of collaboration between various parties, we finally
   locked down on a stable interface for user events that can also work
   with user space only tracing.

   This is implemented by telling the kernel (or user space library, but
   that part is user space only and not part of this patch set), where
   the variable is that the application uses to know if something is
   listening to the trace.

   There's also an interface to tell the kernel about these events,
   which will show up in the /sys/kernel/tracing/events/user_events/
   directory, where it can be enabled.

   When it's enabled, the kernel will update the variable, to tell the
   application to start writing to the kernel.

   See https://lwn.net/Articles/927595/

 - Cleaned up the direct trampolines code to simplify arm64 addition of
   direct trampolines.

   Direct trampolines use the ftrace interface but instead of jumping to
   the ftrace trampoline, applications (mostly BPF) can register their
   own trampoline for performance reasons.

 - Some updates to the fprobe infrastructure. fprobes are more efficient
   than kprobes, as it does not need to save all the registers that
   kprobes on ftrace do. More work needs to be done before the fprobes
   will be exposed as dynamic events.

 - More updates to references to the obsolete path of
   /sys/kernel/debug/tracing for the new /sys/kernel/tracing path.

 - Add a seq_buf_do_printk() helper to seq_bufs, to print a large buffer
   line by line instead of all at once.

   There are users in production kernels that have a large data dump
   that originally used printk() directly, but the data dump was larger
   than what printk() allowed as a single print.

   Using seq_buf() to do the printing fixes that.

 - Add /sys/kernel/tracing/touched_functions that shows all functions
   that was every traced by ftrace or a direct trampoline. This is used
   for debugging issues where a traced function could have caused a
   crash by a bpf program or live patching.

 - Add a "fields" option that is similar to "raw" but outputs the fields
   of the events. It's easier to read by humans.

 - Some minor fixes and clean ups.

* tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (41 commits)
  ring-buffer: Sync IRQ works before buffer destruction
  tracing: Add missing spaces in trace_print_hex_seq()
  ring-buffer: Ensure proper resetting of atomic variables in ring_buffer_reset_online_cpus
  recordmcount: Fix memory leaks in the uwrite function
  tracing/user_events: Limit max fault-in attempts
  tracing/user_events: Prevent same address and bit per process
  tracing/user_events: Ensure bit is cleared on unregister
  tracing/user_events: Ensure write index cannot be negative
  seq_buf: Add seq_buf_do_printk() helper
  tracing: Fix print_fields() for __dyn_loc/__rel_loc
  tracing/user_events: Set event filter_type from type
  ring-buffer: Clearly check null ptr returned by rb_set_head_page()
  tracing: Unbreak user events
  tracing/user_events: Use print_format_fields() for trace output
  tracing/user_events: Align structs with tabs for readability
  tracing/user_events: Limit global user_event count
  tracing/user_events: Charge event allocs to cgroups
  tracing/user_events: Update documentation for ABI
  tracing/user_events: Use write ABI in example
  tracing/user_events: Add ABI self-test
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull tracing updates from Steven Rostedt:

 - User events are finally ready!

   After lots of collaboration between various parties, we finally
   locked down on a stable interface for user events that can also work
   with user space only tracing.

   This is implemented by telling the kernel (or user space library, but
   that part is user space only and not part of this patch set), where
   the variable is that the application uses to know if something is
   listening to the trace.

   There's also an interface to tell the kernel about these events,
   which will show up in the /sys/kernel/tracing/events/user_events/
   directory, where it can be enabled.

   When it's enabled, the kernel will update the variable, to tell the
   application to start writing to the kernel.

   See https://lwn.net/Articles/927595/

 - Cleaned up the direct trampolines code to simplify arm64 addition of
   direct trampolines.

   Direct trampolines use the ftrace interface but instead of jumping to
   the ftrace trampoline, applications (mostly BPF) can register their
   own trampoline for performance reasons.

 - Some updates to the fprobe infrastructure. fprobes are more efficient
   than kprobes, as it does not need to save all the registers that
   kprobes on ftrace do. More work needs to be done before the fprobes
   will be exposed as dynamic events.

 - More updates to references to the obsolete path of
   /sys/kernel/debug/tracing for the new /sys/kernel/tracing path.

 - Add a seq_buf_do_printk() helper to seq_bufs, to print a large buffer
   line by line instead of all at once.

   There are users in production kernels that have a large data dump
   that originally used printk() directly, but the data dump was larger
   than what printk() allowed as a single print.

   Using seq_buf() to do the printing fixes that.

 - Add /sys/kernel/tracing/touched_functions that shows all functions
   that was every traced by ftrace or a direct trampoline. This is used
   for debugging issues where a traced function could have caused a
   crash by a bpf program or live patching.

 - Add a "fields" option that is similar to "raw" but outputs the fields
   of the events. It's easier to read by humans.

 - Some minor fixes and clean ups.

* tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (41 commits)
  ring-buffer: Sync IRQ works before buffer destruction
  tracing: Add missing spaces in trace_print_hex_seq()
  ring-buffer: Ensure proper resetting of atomic variables in ring_buffer_reset_online_cpus
  recordmcount: Fix memory leaks in the uwrite function
  tracing/user_events: Limit max fault-in attempts
  tracing/user_events: Prevent same address and bit per process
  tracing/user_events: Ensure bit is cleared on unregister
  tracing/user_events: Ensure write index cannot be negative
  seq_buf: Add seq_buf_do_printk() helper
  tracing: Fix print_fields() for __dyn_loc/__rel_loc
  tracing/user_events: Set event filter_type from type
  ring-buffer: Clearly check null ptr returned by rb_set_head_page()
  tracing: Unbreak user events
  tracing/user_events: Use print_format_fields() for trace output
  tracing/user_events: Align structs with tabs for readability
  tracing/user_events: Limit global user_event count
  tracing/user_events: Charge event allocs to cgroups
  tracing/user_events: Update documentation for ABI
  tracing/user_events: Use write ABI in example
  tracing/user_events: Add ABI self-test
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>docs: trace: Fix typo in ftrace.rst</title>
<updated>2023-04-20T23:53:38+00:00</updated>
<author>
<name>Lin Yu Chen</name>
<email>starpt.official@gmail.com</email>
</author>
<published>2023-04-12T18:37:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c9b951c3136fb04a9bb89deef5bba8e262410f68'/>
<id>c9b951c3136fb04a9bb89deef5bba8e262410f68</id>
<content type='text'>
There is a typo in the sentence "A kernel developer must be
conscience ...". The word conscience should be conscious.
This patch fixes it.

Signed-off-by: Lin Yu Chen &lt;starpt.official@gmail.com&gt;
Acked-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Link: https://lore.kernel.org/r/20230412183739.89894-1-starpt.official@gmail.com
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is a typo in the sentence "A kernel developer must be
conscience ...". The word conscience should be conscious.
This patch fixes it.

Signed-off-by: Lin Yu Chen &lt;starpt.official@gmail.com&gt;
Acked-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Link: https://lore.kernel.org/r/20230412183739.89894-1-starpt.official@gmail.com
Signed-off-by: Jonathan Corbet &lt;corbet@lwn.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing/user_events: Update documentation for ABI</title>
<updated>2023-03-29T10:52:09+00:00</updated>
<author>
<name>Beau Belgrave</name>
<email>beaub@linux.microsoft.com</email>
</author>
<published>2023-03-28T23:52:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=27dc2ae7c8d88a23014a74171b2194f8d47ecca7'/>
<id>27dc2ae7c8d88a23014a74171b2194f8d47ecca7</id>
<content type='text'>
The ABI for user_events has changed from mmap() based to remote writes.
Update the documentation to reflect these changes, add new section for
unregistering events since lifetime is now tied to tasks instead of
files.

Link: https://lkml.kernel.org/r/20230328235219.203-10-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave &lt;beaub@linux.microsoft.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ABI for user_events has changed from mmap() based to remote writes.
Update the documentation to reflect these changes, add new section for
unregistering events since lifetime is now tied to tasks instead of
files.

Link: https://lkml.kernel.org/r/20230328235219.203-10-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave &lt;beaub@linux.microsoft.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Add "fields" option to show raw trace event fields</title>
<updated>2023-03-29T10:52:08+00:00</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2023-03-28T18:51:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=80a76994b2d88161697bd92b8b6367d9040dbe2a'/>
<id>80a76994b2d88161697bd92b8b6367d9040dbe2a</id>
<content type='text'>
The hex, raw and bin formats come from the old PREEMPT_RT patch set
latency tracer. That actually gave real alternatives to reading the ascii
buffer. But they have started to bit rot and they do not give a good
representation of the tracing data.

Add "fields" option that will read the trace event fields and parse the
data from how the fields are defined:

With "fields" = 0 (default)

 echo 1 &gt; events/sched/sched_switch/enable
 cat trace
         &lt;idle&gt;-0       [003] d..2.   540.078653: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==&gt; next_comm=kworker/3:1 next_pid=83 next_prio=120
     kworker/3:1-83      [003] d..2.   540.078860: sched_switch: prev_comm=kworker/3:1 prev_pid=83 prev_prio=120 prev_state=I ==&gt; next_comm=swapper/3 next_pid=0 next_prio=120
          &lt;idle&gt;-0       [003] d..2.   540.206423: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==&gt; next_comm=sshd next_pid=807 next_prio=120
            sshd-807     [003] d..2.   540.206531: sched_switch: prev_comm=sshd prev_pid=807 prev_prio=120 prev_state=S ==&gt; next_comm=swapper/3 next_pid=0 next_prio=120
          &lt;idle&gt;-0       [001] d..2.   540.206597: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=R ==&gt; next_comm=kworker/u16:4 next_pid=58 next_prio=120
   kworker/u16:4-58      [001] d..2.   540.206617: sched_switch: prev_comm=kworker/u16:4 prev_pid=58 prev_prio=120 prev_state=I ==&gt; next_comm=bash next_pid=830 next_prio=120
            bash-830     [001] d..2.   540.206678: sched_switch: prev_comm=bash prev_pid=830 prev_prio=120 prev_state=R ==&gt; next_comm=kworker/u16:4 next_pid=58 next_prio=120
   kworker/u16:4-58      [001] d..2.   540.206696: sched_switch: prev_comm=kworker/u16:4 prev_pid=58 prev_prio=120 prev_state=I ==&gt; next_comm=bash next_pid=830 next_prio=120
            bash-830     [001] d..2.   540.206713: sched_switch: prev_comm=bash prev_pid=830 prev_prio=120 prev_state=R ==&gt; next_comm=kworker/u16:4 next_pid=58 next_prio=120

 echo 1 &gt; options/fields
           &lt;...&gt;-998     [002] d..2.   538.643732: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/2 prev_state=0x20 (32) prev_prio=0x78 (120) prev_pid=0x3e6 (998) prev_comm=trace-cmd
          &lt;idle&gt;-0       [001] d..2.   538.643806: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x0 (0) prev_comm=swapper/1
            bash-830     [001] d..2.   538.644106: sched_switch: next_prio=0x78 (120) next_pid=0x3a (58) next_comm=kworker/u16:4 prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
   kworker/u16:4-58      [001] d..2.   538.644130: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x80 (128) prev_prio=0x78 (120) prev_pid=0x3a (58) prev_comm=kworker/u16:4
            bash-830     [001] d..2.   538.644180: sched_switch: next_prio=0x78 (120) next_pid=0x3a (58) next_comm=kworker/u16:4 prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
   kworker/u16:4-58      [001] d..2.   538.644185: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x80 (128) prev_prio=0x78 (120) prev_pid=0x3a (58) prev_comm=kworker/u16:4
            bash-830     [001] d..2.   538.644204: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/1 prev_state=0x1 (1) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
          &lt;idle&gt;-0       [003] d..2.   538.644211: sched_switch: next_prio=0x78 (120) next_pid=0x327 (807) next_comm=sshd prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x0 (0) prev_comm=swapper/3
            sshd-807     [003] d..2.   538.644340: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/3 prev_state=0x1 (1) prev_prio=0x78 (120) prev_pid=0x327 (807) prev_comm=sshd

It traces the data safely without using the trace print formatting.

Link: https://lore.kernel.org/linux-trace-kernel/20230328145156.497651be@gandalf.local.home

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Beau Belgrave &lt;beaub@linux.microsoft.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The hex, raw and bin formats come from the old PREEMPT_RT patch set
latency tracer. That actually gave real alternatives to reading the ascii
buffer. But they have started to bit rot and they do not give a good
representation of the tracing data.

Add "fields" option that will read the trace event fields and parse the
data from how the fields are defined:

With "fields" = 0 (default)

 echo 1 &gt; events/sched/sched_switch/enable
 cat trace
         &lt;idle&gt;-0       [003] d..2.   540.078653: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==&gt; next_comm=kworker/3:1 next_pid=83 next_prio=120
     kworker/3:1-83      [003] d..2.   540.078860: sched_switch: prev_comm=kworker/3:1 prev_pid=83 prev_prio=120 prev_state=I ==&gt; next_comm=swapper/3 next_pid=0 next_prio=120
          &lt;idle&gt;-0       [003] d..2.   540.206423: sched_switch: prev_comm=swapper/3 prev_pid=0 prev_prio=120 prev_state=R ==&gt; next_comm=sshd next_pid=807 next_prio=120
            sshd-807     [003] d..2.   540.206531: sched_switch: prev_comm=sshd prev_pid=807 prev_prio=120 prev_state=S ==&gt; next_comm=swapper/3 next_pid=0 next_prio=120
          &lt;idle&gt;-0       [001] d..2.   540.206597: sched_switch: prev_comm=swapper/1 prev_pid=0 prev_prio=120 prev_state=R ==&gt; next_comm=kworker/u16:4 next_pid=58 next_prio=120
   kworker/u16:4-58      [001] d..2.   540.206617: sched_switch: prev_comm=kworker/u16:4 prev_pid=58 prev_prio=120 prev_state=I ==&gt; next_comm=bash next_pid=830 next_prio=120
            bash-830     [001] d..2.   540.206678: sched_switch: prev_comm=bash prev_pid=830 prev_prio=120 prev_state=R ==&gt; next_comm=kworker/u16:4 next_pid=58 next_prio=120
   kworker/u16:4-58      [001] d..2.   540.206696: sched_switch: prev_comm=kworker/u16:4 prev_pid=58 prev_prio=120 prev_state=I ==&gt; next_comm=bash next_pid=830 next_prio=120
            bash-830     [001] d..2.   540.206713: sched_switch: prev_comm=bash prev_pid=830 prev_prio=120 prev_state=R ==&gt; next_comm=kworker/u16:4 next_pid=58 next_prio=120

 echo 1 &gt; options/fields
           &lt;...&gt;-998     [002] d..2.   538.643732: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/2 prev_state=0x20 (32) prev_prio=0x78 (120) prev_pid=0x3e6 (998) prev_comm=trace-cmd
          &lt;idle&gt;-0       [001] d..2.   538.643806: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x0 (0) prev_comm=swapper/1
            bash-830     [001] d..2.   538.644106: sched_switch: next_prio=0x78 (120) next_pid=0x3a (58) next_comm=kworker/u16:4 prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
   kworker/u16:4-58      [001] d..2.   538.644130: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x80 (128) prev_prio=0x78 (120) prev_pid=0x3a (58) prev_comm=kworker/u16:4
            bash-830     [001] d..2.   538.644180: sched_switch: next_prio=0x78 (120) next_pid=0x3a (58) next_comm=kworker/u16:4 prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
   kworker/u16:4-58      [001] d..2.   538.644185: sched_switch: next_prio=0x78 (120) next_pid=0x33e (830) next_comm=bash prev_state=0x80 (128) prev_prio=0x78 (120) prev_pid=0x3a (58) prev_comm=kworker/u16:4
            bash-830     [001] d..2.   538.644204: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/1 prev_state=0x1 (1) prev_prio=0x78 (120) prev_pid=0x33e (830) prev_comm=bash
          &lt;idle&gt;-0       [003] d..2.   538.644211: sched_switch: next_prio=0x78 (120) next_pid=0x327 (807) next_comm=sshd prev_state=0x0 (0) prev_prio=0x78 (120) prev_pid=0x0 (0) prev_comm=swapper/3
            sshd-807     [003] d..2.   538.644340: sched_switch: next_prio=0x78 (120) next_pid=0x0 (0) next_comm=swapper/3 prev_state=0x1 (1) prev_prio=0x78 (120) prev_pid=0x327 (807) prev_comm=sshd

It traces the data safely without using the trace print formatting.

Link: https://lore.kernel.org/linux-trace-kernel/20230328145156.497651be@gandalf.local.home

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Beau Belgrave &lt;beaub@linux.microsoft.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>docs: tracing: Update fprobe documentation</title>
<updated>2023-03-28T22:52:23+00:00</updated>
<author>
<name>Masami Hiramatsu (Google)</name>
<email>mhiramat@kernel.org</email>
</author>
<published>2023-02-01T15:56:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8be098a9eb2710bc5381ba1ebaac660f8d9b6963'/>
<id>8be098a9eb2710bc5381ba1ebaac660f8d9b6963</id>
<content type='text'>
Update fprobe.rst for
 - the private entry_data argument
 - the return value of the entry handler
 - the nr_rethook_node field.

Link: https://lkml.kernel.org/r/167526701579.433354.3057889264263546659.stgit@mhiramat.roam.corp.google.com

Cc: Florent Revest &lt;revest@chromium.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Update fprobe.rst for
 - the private entry_data argument
 - the return value of the entry handler
 - the nr_rethook_node field.

Link: https://lkml.kernel.org/r/167526701579.433354.3057889264263546659.stgit@mhiramat.roam.corp.google.com

Cc: Florent Revest &lt;revest@chromium.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'char-misc-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc</title>
<updated>2023-02-24T20:47:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-24T20:47:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=693fed981eb9bf6e70bfda66bb872e2bb8155671'/>
<id>693fed981eb9bf6e70bfda66bb872e2bb8155671</id>
<content type='text'>
Pull char/misc and other driver subsystem updates from Greg KH:
 "Here is the large set of driver changes for char/misc drivers and
  other smaller driver subsystems that flow through this git tree.

  Included in here are:

   - New IIO drivers and features and improvments in that subsystem

   - New hwtracing drivers and additions to that subsystem

   - lots of interconnect changes and new drivers as that subsystem
     seems under very active development recently. This required also
     merging in the icc subsystem changes through this tree.

   - FPGA driver updates

   - counter subsystem and driver updates

   - MHI driver updates

   - nvmem driver updates

   - documentation updates

   - Other smaller driver updates and fixes, full details in the
     shortlog

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'char-misc-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (223 commits)
  scripts/tags.sh: fix incompatibility with PCRE2
  firmware: coreboot: Remove GOOGLE_COREBOOT_TABLE_ACPI/OF Kconfig entries
  mei: lower the log level for non-fatal failed messages
  mei: bus: disallow driver match while dismantling device
  misc: vmw_balloon: fix memory leak with using debugfs_lookup()
  nvmem: stm32: fix OPTEE dependency
  dt-bindings: nvmem: qfprom: add IPQ8074 compatible
  nvmem: qcom-spmi-sdam: register at device init time
  nvmem: rave-sp-eeprm: fix kernel-doc bad line warning
  nvmem: stm32: detect bsec pta presence for STM32MP15x
  nvmem: stm32: add OP-TEE support for STM32MP13x
  nvmem: core: use nvmem_add_one_cell() in nvmem_add_cells_from_of()
  nvmem: core: add nvmem_add_one_cell()
  nvmem: core: drop the removal of the cells in nvmem_add_cells()
  nvmem: core: move struct nvmem_cell_info to nvmem-provider.h
  nvmem: core: add an index parameter to the cell
  of: property: add #nvmem-cell-cells property
  of: property: make #.*-cells optional for simple props
  of: base: add of_parse_phandle_with_optional_args()
  net: add helper eth_addr_add()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull char/misc and other driver subsystem updates from Greg KH:
 "Here is the large set of driver changes for char/misc drivers and
  other smaller driver subsystems that flow through this git tree.

  Included in here are:

   - New IIO drivers and features and improvments in that subsystem

   - New hwtracing drivers and additions to that subsystem

   - lots of interconnect changes and new drivers as that subsystem
     seems under very active development recently. This required also
     merging in the icc subsystem changes through this tree.

   - FPGA driver updates

   - counter subsystem and driver updates

   - MHI driver updates

   - nvmem driver updates

   - documentation updates

   - Other smaller driver updates and fixes, full details in the
     shortlog

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'char-misc-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (223 commits)
  scripts/tags.sh: fix incompatibility with PCRE2
  firmware: coreboot: Remove GOOGLE_COREBOOT_TABLE_ACPI/OF Kconfig entries
  mei: lower the log level for non-fatal failed messages
  mei: bus: disallow driver match while dismantling device
  misc: vmw_balloon: fix memory leak with using debugfs_lookup()
  nvmem: stm32: fix OPTEE dependency
  dt-bindings: nvmem: qfprom: add IPQ8074 compatible
  nvmem: qcom-spmi-sdam: register at device init time
  nvmem: rave-sp-eeprm: fix kernel-doc bad line warning
  nvmem: stm32: detect bsec pta presence for STM32MP15x
  nvmem: stm32: add OP-TEE support for STM32MP13x
  nvmem: core: use nvmem_add_one_cell() in nvmem_add_cells_from_of()
  nvmem: core: add nvmem_add_one_cell()
  nvmem: core: drop the removal of the cells in nvmem_add_cells()
  nvmem: core: move struct nvmem_cell_info to nvmem-provider.h
  nvmem: core: add an index parameter to the cell
  of: property: add #nvmem-cell-cells property
  of: property: make #.*-cells optional for simple props
  of: base: add of_parse_phandle_with_optional_args()
  net: add helper eth_addr_add()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'probes-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2023-02-23T21:03:08+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-23T21:03:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=2b79eb73e2c4b362a2a261b7b2f718385fb478e4'/>
<id>2b79eb73e2c4b362a2a261b7b2f718385fb478e4</id>
<content type='text'>
Pull kprobes updates from Masami Hiramatsu:

 - Skip negative return code check for snprintf in eprobe

 - Add recursive call test cases for kprobe unit test

 - Add 'char' type to probe events to show it as the character instead
   of value

 - Update kselftest kprobe-event testcase to ignore '__pfx_' symbols

 - Fix kselftest to check filter on eprobe event correctly

 - Add filter on eprobe to the README file in tracefs

 - Fix optprobes to check whether there is 'under unoptimizing' optprobe
   when optimizing another kprobe correctly

 - Fix optprobe to check whether there is 'under unoptimizing' optprobe
   when fetching the original instruction correctly

 - Fix optprobe to free 'forcibly unoptimized' optprobe correctly

* tag 'probes-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/eprobe: no need to check for negative ret value for snprintf
  test_kprobes: Add recursed kprobe test case
  tracing/probe: add a char type to show the character value of traced arguments
  selftests/ftrace: Fix probepoint testcase to ignore __pfx_* symbols
  selftests/ftrace: Fix eprobe syntax test case to check filter support
  tracing/eprobe: Fix to add filter on eprobe description in README file
  x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range
  x86/kprobes: Fix __recover_optprobed_insn check optimizing logic
  kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull kprobes updates from Masami Hiramatsu:

 - Skip negative return code check for snprintf in eprobe

 - Add recursive call test cases for kprobe unit test

 - Add 'char' type to probe events to show it as the character instead
   of value

 - Update kselftest kprobe-event testcase to ignore '__pfx_' symbols

 - Fix kselftest to check filter on eprobe event correctly

 - Add filter on eprobe to the README file in tracefs

 - Fix optprobes to check whether there is 'under unoptimizing' optprobe
   when optimizing another kprobe correctly

 - Fix optprobe to check whether there is 'under unoptimizing' optprobe
   when fetching the original instruction correctly

 - Fix optprobe to free 'forcibly unoptimized' optprobe correctly

* tag 'probes-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/eprobe: no need to check for negative ret value for snprintf
  test_kprobes: Add recursed kprobe test case
  tracing/probe: add a char type to show the character value of traced arguments
  selftests/ftrace: Fix probepoint testcase to ignore __pfx_* symbols
  selftests/ftrace: Fix eprobe syntax test case to check filter support
  tracing/eprobe: Fix to add filter on eprobe description in README file
  x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range
  x86/kprobes: Fix __recover_optprobed_insn check optimizing logic
  kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'trace-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2023-02-23T18:20:49+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-23T18:20:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b72b5fecc1b8a2e595bd03d7d257c88ea3f9fd45'/>
<id>b72b5fecc1b8a2e595bd03d7d257c88ea3f9fd45</id>
<content type='text'>
Pull tracing updates from Steven Rostedt:

 - Add function names as a way to filter function addresses

 - Add sample module to test ftrace ops and dynamic trampolines

 - Allow stack traces to be passed from beginning event to end event for
   synthetic events. This will allow seeing the stack trace of when a
   task is scheduled out and recorded when it gets scheduled back in.

 - Add trace event helper __get_buf() to use as a temporary buffer when
   printing out trace event output.

 - Add kernel command line to create trace instances on boot up.

 - Add enabling of events to instances created at boot up.

 - Add trace_array_puts() to write into instances.

 - Allow boot instances to take a snapshot at the end of boot up.

 - Allow live patch modules to include trace events

 - Minor fixes and clean ups

* tag 'trace-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
  tracing: Remove unnecessary NULL assignment
  tracepoint: Allow livepatch module add trace event
  tracing: Always use canonical ftrace path
  tracing/histogram: Fix stacktrace histogram Documententation
  tracing/histogram: Fix stacktrace key
  tracing/histogram: Fix a few problems with stacktrace variable printing
  tracing: Add BUILD_BUG() to make sure stacktrace fits in strings
  tracing/histogram: Don't use strlen to find length of stacktrace variables
  tracing: Allow boot instances to have snapshot buffers
  tracing: Add trace_array_puts() to write into instance
  tracing: Add enabling of events to boot instances
  tracing: Add creation of instances at boot command line
  tracing: Fix trace_event_raw_event_synth() if else statement
  samples: ftrace: Make some global variables static
  ftrace: sample: avoid open-coded 64-bit division
  samples: ftrace: Include the nospec-branch.h only for x86
  tracing: Acquire buffer from temparary trace sequence
  tracing/histogram: Wrap remaining shell snippets in code blocks
  tracing/osnoise: No need for schedule_hrtimeout range
  bpf/tracing: Use stage6 of tracing to not duplicate macros
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull tracing updates from Steven Rostedt:

 - Add function names as a way to filter function addresses

 - Add sample module to test ftrace ops and dynamic trampolines

 - Allow stack traces to be passed from beginning event to end event for
   synthetic events. This will allow seeing the stack trace of when a
   task is scheduled out and recorded when it gets scheduled back in.

 - Add trace event helper __get_buf() to use as a temporary buffer when
   printing out trace event output.

 - Add kernel command line to create trace instances on boot up.

 - Add enabling of events to instances created at boot up.

 - Add trace_array_puts() to write into instances.

 - Allow boot instances to take a snapshot at the end of boot up.

 - Allow live patch modules to include trace events

 - Minor fixes and clean ups

* tag 'trace-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (31 commits)
  tracing: Remove unnecessary NULL assignment
  tracepoint: Allow livepatch module add trace event
  tracing: Always use canonical ftrace path
  tracing/histogram: Fix stacktrace histogram Documententation
  tracing/histogram: Fix stacktrace key
  tracing/histogram: Fix a few problems with stacktrace variable printing
  tracing: Add BUILD_BUG() to make sure stacktrace fits in strings
  tracing/histogram: Don't use strlen to find length of stacktrace variables
  tracing: Allow boot instances to have snapshot buffers
  tracing: Add trace_array_puts() to write into instance
  tracing: Add enabling of events to boot instances
  tracing: Add creation of instances at boot command line
  tracing: Fix trace_event_raw_event_synth() if else statement
  samples: ftrace: Make some global variables static
  ftrace: sample: avoid open-coded 64-bit division
  samples: ftrace: Include the nospec-branch.h only for x86
  tracing: Acquire buffer from temparary trace sequence
  tracing/histogram: Wrap remaining shell snippets in code blocks
  tracing/osnoise: No need for schedule_hrtimeout range
  bpf/tracing: Use stage6 of tracing to not duplicate macros
  ...
</pre>
</div>
</content>
</entry>
</feed>
