<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel/trace, branch v6.17-rc2</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 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2025-08-03T23:23:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-08-03T23:23:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e991acf1bce7a428794514cbbe216973c9c0a3c8'/>
<id>e991acf1bce7a428794514cbbe216973c9c0a3c8</id>
<content type='text'>
Pull non-MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "squashfs: Remove page-&gt;mapping references" (Matthew Wilcox) gets
     us closer to being able to remove page-&gt;mapping

   - "relayfs: misc changes" (Jason Xing) does some maintenance and
     minor feature addition work in relayfs

   - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
     us from static preallocation of the kdump crashkernel's working
     memory over to dynamic allocation. So the difficulty of a-priori
     estimation of the second kernel's needs is removed and the first
     kernel obtains extra memory

   - "generalize panic_print's dump function to be used by other
     kernel parts" (Feng Tang) implements some consolidation and
     rationalization of the various ways in which a failing kernel
     splats information at the operator

* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
  tools/getdelays: add backward compatibility for taskstats version
  kho: add test for kexec handover
  delaytop: enhance error logging and add PSI feature description
  samples: Kconfig: fix spelling mistake "instancess" -&gt; "instances"
  fat: fix too many log in fat_chain_add()
  scripts/spelling.txt: add notifer||notifier to spelling.txt
  xen/xenbus: fix typo "notifer"
  net: mvneta: fix typo "notifer"
  drm/xe: fix typo "notifer"
  cxl: mce: fix typo "notifer"
  KVM: x86: fix typo "notifer"
  MAINTAINERS: add maintainers for delaytop
  ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
  ucount: fix atomic_long_inc_below() argument type
  kexec: enable CMA based contiguous allocation
  stackdepot: make max number of pools boot-time configurable
  lib/xxhash: remove unused functions
  init/Kconfig: restore CONFIG_BROKEN help text
  lib/raid6: update recov_rvv.c zero page usage
  docs: update docs after introducing delaytop
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull non-MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "squashfs: Remove page-&gt;mapping references" (Matthew Wilcox) gets
     us closer to being able to remove page-&gt;mapping

   - "relayfs: misc changes" (Jason Xing) does some maintenance and
     minor feature addition work in relayfs

   - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
     us from static preallocation of the kdump crashkernel's working
     memory over to dynamic allocation. So the difficulty of a-priori
     estimation of the second kernel's needs is removed and the first
     kernel obtains extra memory

   - "generalize panic_print's dump function to be used by other
     kernel parts" (Feng Tang) implements some consolidation and
     rationalization of the various ways in which a failing kernel
     splats information at the operator

* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
  tools/getdelays: add backward compatibility for taskstats version
  kho: add test for kexec handover
  delaytop: enhance error logging and add PSI feature description
  samples: Kconfig: fix spelling mistake "instancess" -&gt; "instances"
  fat: fix too many log in fat_chain_add()
  scripts/spelling.txt: add notifer||notifier to spelling.txt
  xen/xenbus: fix typo "notifer"
  net: mvneta: fix typo "notifer"
  drm/xe: fix typo "notifer"
  cxl: mce: fix typo "notifer"
  KVM: x86: fix typo "notifer"
  MAINTAINERS: add maintainers for delaytop
  ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
  ucount: fix atomic_long_inc_below() argument type
  kexec: enable CMA based contiguous allocation
  stackdepot: make max number of pools boot-time configurable
  lib/xxhash: remove unused functions
  init/Kconfig: restore CONFIG_BROKEN help text
  lib/raid6: update recov_rvv.c zero page usage
  docs: update docs after introducing delaytop
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'trace-v6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2025-08-03T22:03:04+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-08-03T22:03:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3c4a063b1f8ab71352df1421d9668521acb63cd9'/>
<id>3c4a063b1f8ab71352df1421d9668521acb63cd9</id>
<content type='text'>
Pull more tracing updates from Steven Rostedt:

 - Remove unneeded goto out statements

   Over time, the logic was restructured but left a "goto out" where the
   out label simply did a "return ret;". Instead of jumping to this out
   label, simply return immediately and remove the out label.

 - Add guard(ring_buffer_nest)

   Some calls to the tracing ring buffer can happen when the ring buffer
   is already being written to at the same context (for example, a
   trace_printk() in between a ring_buffer_lock_reserve() and a
   ring_buffer_unlock_commit()).

   In order to not trigger the recursion detection, these functions use
   ring_buffer_nest_start() and ring_buffer_nest_end(). Create a guard()
   for these functions so that their use cases can be simplified and not
   need to use goto for the release.

 - Clean up the tracing code with guard() and __free() logic

   There were several locations that were prime candidates for using
   guard() and __free() helpers. Switch them over to use them.

 - Fix output of function argument traces for unsigned int values

   The function tracer with "func-args" option set will record up to 6
   argument registers and then use BTF to format them for human
   consumption when the trace file is read. There are several arguments
   that are "unsigned long" and even "unsigned int" that are either and
   address or a mask. It is easier to understand if they were printed
   using hexadecimal instead of decimal. The old method just printed all
   non-pointer values as signed integers, which made it even worse for
   unsigned integers.

   For instance, instead of:

     __local_bh_disable_ip(ip=-2127311112, cnt=256) &lt;-handle_softirqs

   show:

     __local_bh_disable_ip(ip=0xffffffff8133cef8, cnt=0x100) &lt;-handle_softirqs"

* tag 'trace-v6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Have unsigned int function args displayed as hexadecimal
  ring-buffer: Convert ring_buffer_write() to use guard(preempt_notrace)
  tracing: Use __free(kfree) in trace.c to remove gotos
  tracing: Add guard() around locks and mutexes in trace.c
  tracing: Add guard(ring_buffer_nest)
  tracing: Remove unneeded goto out logic
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more tracing updates from Steven Rostedt:

 - Remove unneeded goto out statements

   Over time, the logic was restructured but left a "goto out" where the
   out label simply did a "return ret;". Instead of jumping to this out
   label, simply return immediately and remove the out label.

 - Add guard(ring_buffer_nest)

   Some calls to the tracing ring buffer can happen when the ring buffer
   is already being written to at the same context (for example, a
   trace_printk() in between a ring_buffer_lock_reserve() and a
   ring_buffer_unlock_commit()).

   In order to not trigger the recursion detection, these functions use
   ring_buffer_nest_start() and ring_buffer_nest_end(). Create a guard()
   for these functions so that their use cases can be simplified and not
   need to use goto for the release.

 - Clean up the tracing code with guard() and __free() logic

   There were several locations that were prime candidates for using
   guard() and __free() helpers. Switch them over to use them.

 - Fix output of function argument traces for unsigned int values

   The function tracer with "func-args" option set will record up to 6
   argument registers and then use BTF to format them for human
   consumption when the trace file is read. There are several arguments
   that are "unsigned long" and even "unsigned int" that are either and
   address or a mask. It is easier to understand if they were printed
   using hexadecimal instead of decimal. The old method just printed all
   non-pointer values as signed integers, which made it even worse for
   unsigned integers.

   For instance, instead of:

     __local_bh_disable_ip(ip=-2127311112, cnt=256) &lt;-handle_softirqs

   show:

     __local_bh_disable_ip(ip=0xffffffff8133cef8, cnt=0x100) &lt;-handle_softirqs"

* tag 'trace-v6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Have unsigned int function args displayed as hexadecimal
  ring-buffer: Convert ring_buffer_write() to use guard(preempt_notrace)
  tracing: Use __free(kfree) in trace.c to remove gotos
  tracing: Add guard() around locks and mutexes in trace.c
  tracing: Add guard(ring_buffer_nest)
  tracing: Remove unneeded goto out logic
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'modules-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux</title>
<updated>2025-08-03T21:16:52+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-08-03T21:16:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8877fcb70fd7ae0a4d5ac73d250dc255f7ff5a2c'/>
<id>8877fcb70fd7ae0a4d5ac73d250dc255f7ff5a2c</id>
<content type='text'>
Pull module updates from Daniel Gomez:
 "This is a small set of changes for modules, primarily to extend module
  users to use the module data structures in combination with the
  already no-op stub module functions, even when support for modules is
  disabled in the kernel configuration. This change follows the kernel's
  coding style for conditional compilation and allows kunit code to drop
  all CONFIG_MODULES ifdefs, which is also part of the changes. This
  should allow others part of the kernel to do the same cleanup.

  The remaining changes include a fix for module name length handling
  which could potentially lead to the removal of an incorrect module,
  and various cleanups"

* tag 'modules-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
  module: Rename MAX_PARAM_PREFIX_LEN to __MODULE_NAME_LEN
  tracing: Replace MAX_PARAM_PREFIX_LEN with MODULE_NAME_LEN
  module: Restore the moduleparam prefix length check
  module: Remove unnecessary +1 from last_unloaded_module::name size
  module: Prevent silent truncation of module name in delete_module(2)
  kunit: test: Drop CONFIG_MODULE ifdeffery
  module: make structure definitions always visible
  module: move 'struct module_use' to internal.h
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull module updates from Daniel Gomez:
 "This is a small set of changes for modules, primarily to extend module
  users to use the module data structures in combination with the
  already no-op stub module functions, even when support for modules is
  disabled in the kernel configuration. This change follows the kernel's
  coding style for conditional compilation and allows kunit code to drop
  all CONFIG_MODULES ifdefs, which is also part of the changes. This
  should allow others part of the kernel to do the same cleanup.

  The remaining changes include a fix for module name length handling
  which could potentially lead to the removal of an incorrect module,
  and various cleanups"

* tag 'modules-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
  module: Rename MAX_PARAM_PREFIX_LEN to __MODULE_NAME_LEN
  tracing: Replace MAX_PARAM_PREFIX_LEN with MODULE_NAME_LEN
  module: Restore the moduleparam prefix length check
  module: Remove unnecessary +1 from last_unloaded_module::name size
  module: Prevent silent truncation of module name in delete_module(2)
  kunit: test: Drop CONFIG_MODULE ifdeffery
  module: make structure definitions always visible
  module: move 'struct module_use' to internal.h
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Have unsigned int function args displayed as hexadecimal</title>
<updated>2025-08-01T23:14:51+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2025-08-01T20:56:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3ca824369b71d4b441e1fdcdee8e66bcb05510a9'/>
<id>3ca824369b71d4b441e1fdcdee8e66bcb05510a9</id>
<content type='text'>
Most function arguments that are passed in as unsigned int or unsigned
long are better displayed as hexadecimal than normal integer. For example,
the functions:

static void __create_object(unsigned long ptr, size_t size,
				int min_count, gfp_t gfp, unsigned int objflags);

static bool stack_access_ok(struct unwind_state *state, unsigned long _addr,
			    size_t len);

void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);

Show up in the trace as:

    __create_object(ptr=-131387050520576, size=4096, min_count=1, gfp=3264, objflags=0) &lt;-kmem_cache_alloc_noprof
    stack_access_ok(state=0xffffc9000233fc98, _addr=-60473102566256, len=8) &lt;-unwind_next_frame
    __local_bh_disable_ip(ip=-2127311112, cnt=256) &lt;-handle_softirqs

Instead, by displaying unsigned as hexadecimal, they look more like this:

    __create_object(ptr=0xffff8881028d2080, size=0x280, min_count=1, gfp=0x82820, objflags=0x0) &lt;-kmem_cache_alloc_node_noprof
    stack_access_ok(state=0xffffc90000003938, _addr=0xffffc90000003930, len=0x8) &lt;-unwind_next_frame
    __local_bh_disable_ip(ip=0xffffffff8133cef8, cnt=0x100) &lt;-handle_softirqs

Which is much easier to understand as most unsigned longs are usually just
pointers. Even the "unsigned int cnt" in __local_bh_disable_ip() looks
better as hexadecimal as a lot of flags are passed as unsigned.

Changes since v2: https://lore.kernel.org/20250801111453.01502861@gandalf.local.home

- Use btf_int_encoding() instead of open coding it (Martin KaFai Lau)

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Douglas Raillard &lt;douglas.raillard@arm.com&gt;
Cc: Martin KaFai Lau &lt;martin.lau@linux.dev&gt;
Link: https://lore.kernel.org/20250801165601.7770d65c@gandalf.local.home
Acked-by: Yonghong Song &lt;yonghong.song@linux.dev&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>
Most function arguments that are passed in as unsigned int or unsigned
long are better displayed as hexadecimal than normal integer. For example,
the functions:

static void __create_object(unsigned long ptr, size_t size,
				int min_count, gfp_t gfp, unsigned int objflags);

static bool stack_access_ok(struct unwind_state *state, unsigned long _addr,
			    size_t len);

void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);

Show up in the trace as:

    __create_object(ptr=-131387050520576, size=4096, min_count=1, gfp=3264, objflags=0) &lt;-kmem_cache_alloc_noprof
    stack_access_ok(state=0xffffc9000233fc98, _addr=-60473102566256, len=8) &lt;-unwind_next_frame
    __local_bh_disable_ip(ip=-2127311112, cnt=256) &lt;-handle_softirqs

Instead, by displaying unsigned as hexadecimal, they look more like this:

    __create_object(ptr=0xffff8881028d2080, size=0x280, min_count=1, gfp=0x82820, objflags=0x0) &lt;-kmem_cache_alloc_node_noprof
    stack_access_ok(state=0xffffc90000003938, _addr=0xffffc90000003930, len=0x8) &lt;-unwind_next_frame
    __local_bh_disable_ip(ip=0xffffffff8133cef8, cnt=0x100) &lt;-handle_softirqs

Which is much easier to understand as most unsigned longs are usually just
pointers. Even the "unsigned int cnt" in __local_bh_disable_ip() looks
better as hexadecimal as a lot of flags are passed as unsigned.

Changes since v2: https://lore.kernel.org/20250801111453.01502861@gandalf.local.home

- Use btf_int_encoding() instead of open coding it (Martin KaFai Lau)

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Douglas Raillard &lt;douglas.raillard@arm.com&gt;
Cc: Martin KaFai Lau &lt;martin.lau@linux.dev&gt;
Link: https://lore.kernel.org/20250801165601.7770d65c@gandalf.local.home
Acked-by: Yonghong Song &lt;yonghong.song@linux.dev&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ring-buffer: Convert ring_buffer_write() to use guard(preempt_notrace)</title>
<updated>2025-08-01T20:49:15+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2025-08-01T20:37:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=db5f0c3e3e60939bb2ecc2dbdea4e6f32252620b'/>
<id>db5f0c3e3e60939bb2ecc2dbdea4e6f32252620b</id>
<content type='text'>
The function ring_buffer_write() has a goto out to only do a
preempt_enable_notrace(). This can be replaced by a guard.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203858.205479143@kernel.org
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 function ring_buffer_write() has a goto out to only do a
preempt_enable_notrace(). This can be replaced by a guard.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203858.205479143@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Use __free(kfree) in trace.c to remove gotos</title>
<updated>2025-08-01T20:49:15+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2025-08-01T20:37:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=12d5189615862a9eb06d4aa7c8a990bcde2ebb01'/>
<id>12d5189615862a9eb06d4aa7c8a990bcde2ebb01</id>
<content type='text'>
There's a couple of locations that have goto out in trace.c for the only
purpose of freeing a variable that was allocated. These can be replaced
with __free(kfree).

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203858.040892777@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There's a couple of locations that have goto out in trace.c for the only
purpose of freeing a variable that was allocated. These can be replaced
with __free(kfree).

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203858.040892777@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Add guard() around locks and mutexes in trace.c</title>
<updated>2025-08-01T20:49:15+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2025-08-01T20:37:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=debe57fbe12cb16881b2db1f1787eb9673a8b8b0'/>
<id>debe57fbe12cb16881b2db1f1787eb9673a8b8b0</id>
<content type='text'>
There's several locations in trace.c that can be simplified by using
guards around raw_spin_lock_irqsave, mutexes and preempt disabling.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203857.879085376@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There's several locations in trace.c that can be simplified by using
guards around raw_spin_lock_irqsave, mutexes and preempt disabling.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203857.879085376@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Add guard(ring_buffer_nest)</title>
<updated>2025-08-01T20:49:15+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2025-08-01T20:37:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=788fa4b47cdcd9b3d8c2d02ac0b3cd2540305f18'/>
<id>788fa4b47cdcd9b3d8c2d02ac0b3cd2540305f18</id>
<content type='text'>
Some calls to the tracing ring buffer can happen when the ring buffer is
already being written to by the same context (for example, a
trace_printk() in between a ring_buffer_lock_reserve() and a
ring_buffer_unlock_commit()).

In order to not trigger the recursion detection, these functions use
ring_buffer_nest_start() and ring_buffer_nest_end(). Create a guard() for
these functions so that their use cases can be simplified and not need to
use goto for the release.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203857.710501021@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some calls to the tracing ring buffer can happen when the ring buffer is
already being written to by the same context (for example, a
trace_printk() in between a ring_buffer_lock_reserve() and a
ring_buffer_unlock_commit()).

In order to not trigger the recursion detection, these functions use
ring_buffer_nest_start() and ring_buffer_nest_end(). Create a guard() for
these functions so that their use cases can be simplified and not need to
use goto for the release.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203857.710501021@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Remove unneeded goto out logic</title>
<updated>2025-08-01T20:49:14+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2025-08-01T20:37:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c89504a703fb779052213add0e8ed642f4a4f1c8'/>
<id>c89504a703fb779052213add0e8ed642f4a4f1c8</id>
<content type='text'>
Several places in the trace.c file there's a goto out where the out is
simply a return. There's no reason to jump to the out label if it's not
doing any more logic but simply returning from the function.

Replace the goto outs with a return and remove the out labels.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203857.538726745@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Several places in the trace.c file there's a goto out where the out is
simply a return. There's no reason to jump to the out label if it's not
doing any more logic but simply returning from the function.

Replace the goto outs with a return and remove the out labels.

Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Link: https://lore.kernel.org/20250801203857.538726745@kernel.org
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'trace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2025-08-01T17:29:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-08-01T17:29:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d6f38c12396397e48092ad9e8a4d7be4de51b942'/>
<id>d6f38c12396397e48092ad9e8a4d7be4de51b942</id>
<content type='text'>
Pull tracing updates from Steven Rostedt:

 - Deprecate auto-mounting tracefs to /sys/kernel/debug/tracing

   When tracefs was first introduced back in 2014, the directory
   /sys/kernel/tracing was added and is the designated location to mount
   tracefs. To keep backward compatibility, tracefs was auto-mounted in
   /sys/kernel/debug/tracing as well.

   All distros now mount tracefs on /sys/kernel/tracing. Having it seen
   in two different locations has lead to various issues and
   inconsistencies.

   The VFS folks have to also maintain debugfs_create_automount() for
   this single user.

   It's been over 10 years. Tooling and scripts should start replacing
   the debugfs location with the tracefs one. The reason tracefs was
   created in the first place was to allow access to the tracing
   facilities without the need to configure debugfs into the kernel.
   Using tracefs should now be more robust.

   A new config is created: CONFIG_TRACEFS_AUTOMOUNT_DEPRECATED which is
   default y, so that the kernel is still built with the automount. This
   config allows those that want to remove the automount from debugfs to
   do so.

   When tracefs is accessed from /sys/kernel/debug/tracing, the
   following printk is triggerd:

     pr_warn("NOTICE: Automounting of tracing to debugfs is deprecated and will be removed in 2030\n");

   This gives users another 5 years to fix their scripts.

 - Use queue_rcu_work() instead of call_rcu() for freeing event filters

   The number of filters to be free can be many depending on the number
   of events within an event system. Freeing them from softirq context
   can potentially cause undesired latency. Use the RCU workqueue to
   free them instead.

 - Remove pointless memory barriers in latency code

   Memory barriers were added to some of the latency code a long time
   ago with the idea of "making them visible", but that's not what
   memory barriers are for. They are to synchronize access between
   different variables. There was no synchronization here making them
   pointless.

 - Remove "__attribute__()" from the type field of event format

   When LLVM is used to compile the kernel with CONFIG_DEBUG_INFO_BTF=y
   and PAHOLE_HAS_BTF_TAG=y, some of the format fields get expanded with
   the following:

     field:const char * filename;      offset:24;      size:8; signed:0;

   Turns into:

     field:const char __attribute__((btf_type_tag("user"))) * filename;      offset:24;      size:8; signed:0;

   This confuses parsers. Add code to strip these tags from the strings.

 - Add eprobe config option CONFIG_EPROBE_EVENTS

   Eprobes were added back in 5.15 but were only enabled when another
   probe was enabled (kprobe, fprobe, uprobe, etc). The eprobes had no
   config option of their own. Add one as they should be a separate
   entity.

   It's default y to keep with the old kernels but still has
   dependencies on TRACING and HAVE_REGS_AND_STACK_ACCESS_API.

 - Add eprobe documentation

   When eprobes were added back in 5.15 no documentation was added to
   describe them. This needs to be rectified.

 - Replace open coded cpumask_next_wrap() in move_to_next_cpu()

 - Have preemptirq_delay_run() use off-stack CPU mask

 - Remove obsolete comment about pelt_cfs event

   DECLARE_TRACE() appends "_tp" to trace events now, but the comment
   above pelt_cfs still mentioned appending it manually.

 - Remove EVENT_FILE_FL_SOFT_MODE flag

   The SOFT_MODE flag was required when the soft enabling and disabling
   of trace events was first introduced. But there was a bug with this
   approach as it only worked for a single instance. When multiple users
   required soft disabling and disabling the code was changed to have a
   ref count. The SOFT_MODE flag is now set iff the ref count is non
   zero. This is redundant and just reading the ref count is good
   enough.

 - Fix typo in comment

* tag 'trace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Add documentation about eprobes
  tracing: Have eprobes have their own config option
  tracing: Remove "__attribute__()" from the type field of event format
  tracing: Deprecate auto-mounting tracefs in debugfs
  tracing: Fix comment in trace_module_remove_events()
  tracing: Remove EVENT_FILE_FL_SOFT_MODE flag
  tracing: Remove pointless memory barriers
  tracing/sched: Remove obsolete comment on suffixes
  kernel: trace: preemptirq_delay_test: use offstack cpu mask
  tracing: Use queue_rcu_work() to free filters
  tracing: Replace opencoded cpumask_next_wrap() in move_to_next_cpu()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull tracing updates from Steven Rostedt:

 - Deprecate auto-mounting tracefs to /sys/kernel/debug/tracing

   When tracefs was first introduced back in 2014, the directory
   /sys/kernel/tracing was added and is the designated location to mount
   tracefs. To keep backward compatibility, tracefs was auto-mounted in
   /sys/kernel/debug/tracing as well.

   All distros now mount tracefs on /sys/kernel/tracing. Having it seen
   in two different locations has lead to various issues and
   inconsistencies.

   The VFS folks have to also maintain debugfs_create_automount() for
   this single user.

   It's been over 10 years. Tooling and scripts should start replacing
   the debugfs location with the tracefs one. The reason tracefs was
   created in the first place was to allow access to the tracing
   facilities without the need to configure debugfs into the kernel.
   Using tracefs should now be more robust.

   A new config is created: CONFIG_TRACEFS_AUTOMOUNT_DEPRECATED which is
   default y, so that the kernel is still built with the automount. This
   config allows those that want to remove the automount from debugfs to
   do so.

   When tracefs is accessed from /sys/kernel/debug/tracing, the
   following printk is triggerd:

     pr_warn("NOTICE: Automounting of tracing to debugfs is deprecated and will be removed in 2030\n");

   This gives users another 5 years to fix their scripts.

 - Use queue_rcu_work() instead of call_rcu() for freeing event filters

   The number of filters to be free can be many depending on the number
   of events within an event system. Freeing them from softirq context
   can potentially cause undesired latency. Use the RCU workqueue to
   free them instead.

 - Remove pointless memory barriers in latency code

   Memory barriers were added to some of the latency code a long time
   ago with the idea of "making them visible", but that's not what
   memory barriers are for. They are to synchronize access between
   different variables. There was no synchronization here making them
   pointless.

 - Remove "__attribute__()" from the type field of event format

   When LLVM is used to compile the kernel with CONFIG_DEBUG_INFO_BTF=y
   and PAHOLE_HAS_BTF_TAG=y, some of the format fields get expanded with
   the following:

     field:const char * filename;      offset:24;      size:8; signed:0;

   Turns into:

     field:const char __attribute__((btf_type_tag("user"))) * filename;      offset:24;      size:8; signed:0;

   This confuses parsers. Add code to strip these tags from the strings.

 - Add eprobe config option CONFIG_EPROBE_EVENTS

   Eprobes were added back in 5.15 but were only enabled when another
   probe was enabled (kprobe, fprobe, uprobe, etc). The eprobes had no
   config option of their own. Add one as they should be a separate
   entity.

   It's default y to keep with the old kernels but still has
   dependencies on TRACING and HAVE_REGS_AND_STACK_ACCESS_API.

 - Add eprobe documentation

   When eprobes were added back in 5.15 no documentation was added to
   describe them. This needs to be rectified.

 - Replace open coded cpumask_next_wrap() in move_to_next_cpu()

 - Have preemptirq_delay_run() use off-stack CPU mask

 - Remove obsolete comment about pelt_cfs event

   DECLARE_TRACE() appends "_tp" to trace events now, but the comment
   above pelt_cfs still mentioned appending it manually.

 - Remove EVENT_FILE_FL_SOFT_MODE flag

   The SOFT_MODE flag was required when the soft enabling and disabling
   of trace events was first introduced. But there was a bug with this
   approach as it only worked for a single instance. When multiple users
   required soft disabling and disabling the code was changed to have a
   ref count. The SOFT_MODE flag is now set iff the ref count is non
   zero. This is redundant and just reading the ref count is good
   enough.

 - Fix typo in comment

* tag 'trace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Add documentation about eprobes
  tracing: Have eprobes have their own config option
  tracing: Remove "__attribute__()" from the type field of event format
  tracing: Deprecate auto-mounting tracefs in debugfs
  tracing: Fix comment in trace_module_remove_events()
  tracing: Remove EVENT_FILE_FL_SOFT_MODE flag
  tracing: Remove pointless memory barriers
  tracing/sched: Remove obsolete comment on suffixes
  kernel: trace: preemptirq_delay_test: use offstack cpu mask
  tracing: Use queue_rcu_work() to free filters
  tracing: Replace opencoded cpumask_next_wrap() in move_to_next_cpu()
</pre>
</div>
</content>
</entry>
</feed>
