linux-toradex.git/kernel/trace/trace_functions_graph.c, branch v6.19-rc2

Merge tag 'ftrace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-12-05T18:13:04+00:00

Pull ftrace updates from Steven Rostedt:

 - Fix regression of pid filtering of function graph tracer

   When the function graph tracer allowed multiple instances of graph
   tracing using subops, the filtering by pid broke.

   The ftrace_ops->private that was used for pid filtering wasn't
   updated on creation.

   The wrong function entry callback was used when pid filtering was
   enabled when the function graph tracer started, which meant that
   the pid filtering wasn't happening.

 - Remove no longer needed ftrace_trace_task()

   With PID filtering working via ftrace_pids_enabled() and
   fgraph_pid_func(), the coarse-grained ftrace_trace_task()
   check in graph_entry() is obsolete.

   It was only a fallback for uninitialized op->private (now fixed),
   and its removal ensures consistent PID filtering with standard
   function tracing.

* tag 'ftrace-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  fgraph: Remove coarse PID filtering from graph_entry()
  fgraph: Check ftrace_pids_enabled on registration for early filtering
  fgraph: Initialize ftrace_ops->private for function graph ops

fgraph: Remove coarse PID filtering from graph_entry()

2025-11-26T20:41:35+00:00

With PID filtering working via ftrace_pids_enabled() and fgraph_pid_func,
the coarse-grained ftrace_trace_task() check in graph_entry() is obsolete.

It was only a fallback for uninitialized op->private (now fixed), and its
removal ensures consistent PID filtering with standard function tracing.

Also remove unused ftrace_trace_task() definition from trace.h.

Cc: 
Cc: 
Cc: 
Cc: 
Cc: 
Cc: 
Link: https://patch.msgid.link/20251126173552333XoJZN20143fWbsdTEtWoU@zte.com.cn
Signed-off-by: Shengming Hu 
Signed-off-by: Steven Rostedt (Google)

function_graph: Enable funcgraph-args and funcgraph-retaddr to work simultaneously

2025-11-26T20:13:30+00:00

Currently, the funcgraph-args and funcgraph-retaddr features are
mutually exclusive. This patch resolves this limitation by allowing
funcgraph-retaddr to have an args array.

To verify the change, use perf to trace vfs_write with both options
enabled:

Before:
 # perf ftrace -G vfs_write --graph-opts args,retaddr
   ......
   down_read() { /* <-n_tty_write+0xa3/0x540 */
     __cond_resched(); /* <-down_read+0x12/0x160 */
     preempt_count_add(); /* <-down_read+0x3b/0x160 */
     preempt_count_sub(); /* <-down_read+0x8b/0x160 */
   }

After:
 # perf ftrace -G vfs_write --graph-opts args,retaddr
   ......
   down_read(sem=0xffff8880100bea78) { /* <-n_tty_write+0xa3/0x540 */
     __cond_resched(); /* <-down_read+0x12/0x160 */
     preempt_count_add(val=1); /* <-down_read+0x3b/0x160 */
     preempt_count_sub(val=1); /* <-down_read+0x8b/0x160 */
   }

Cc: Steven Rostedt (Google) 
Cc: Sven Schnelle 
Cc: Masami Hiramatsu 
Cc: Xiaoqin Zhang 
Link: https://patch.msgid.link/20251125093425.2563849-1-dolinux.peng@gmail.com
Signed-off-by: pengdonglin 
Signed-off-by: Steven Rostedt (Google)

fgraph: Make fgraph_no_sleep_time signed

2025-11-26T20:13:28+00:00

The variable fgraph_no_sleep_time changed from being a boolean to being a
counter. A check is made to make sure that it never goes below zero. But
the variable being unsigned makes the check always fail even if it does go
below zero.

Make the variable a signed int so that checking it going below zero still
works.

Cc: Masami Hiramatsu 
Cc: Mathieu Desnoyers 
Link: https://patch.msgid.link/20251125104751.4c9c7f28@gandalf.local.home
Fixes: 5abb6ccb58f0 ("tracing: Have function graph tracer option sleep-time be per instance")
Reported-by: Dan Carpenter 
Closes: https://lore.kernel.org/all/aR1yRQxDmlfLZzoo@stanley.mountain/
Signed-off-by: Steven Rostedt (Google)

tracing: Convert function graph set_flags() to use a switch() statement

2025-11-14T19:30:55+00:00

Currently the set_flags() of the function graph tracer has a bunch of:

  if (bit == FLAG1) {
	[..]
  }

  if (bit == FLAG2) {
	[..]
  }

To clean it up a bit, convert it over to a switch statement.

Cc: Masami Hiramatsu 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20251114192319.117123664@kernel.org
Signed-off-by: Steven Rostedt (Google)

tracing: Have function graph tracer option sleep-time be per instance

2025-11-14T19:30:55+00:00

Currently the option to have function graph tracer to ignore time spent
when a task is sleeping is global when the interface is per-instance.
Changing the value in one instance will affect the results of another
instance that is also running the function graph tracer. This can lead to
confusing results.

Cc: Masami Hiramatsu 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20251114192318.950255167@kernel.org
Fixes: c132be2c4fcc1 ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Steven Rostedt (Google)

tracing: Move graph-time out of function graph options

2025-11-14T19:30:55+00:00

The option "graph-time" affects the function profiler when it is using the
function graph infrastructure. It has nothing to do with the function
graph tracer itself. The option only affects the global function profiler
and does nothing to the function graph tracer.

Move it out of the function graph tracer options and make it a global
option that is only available at the top level instance.

Cc: Masami Hiramatsu 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20251114192318.781711154@kernel.org
Signed-off-by: Steven Rostedt (Google)

tracing: Have function graph tracer option funcgraph-irqs be per instance

2025-11-14T19:30:54+00:00

Currently the option to trace interrupts in the function graph tracer is
global when the interface is per-instance. Changing the value in one
instance will affect the results of another instance that is also running
the function graph tracer. This can lead to confusing results.

Cc: Masami Hiramatsu 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20251114192318.613867934@kernel.org
Fixes: c132be2c4fcc1 ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Steven Rostedt (Google)

tracing: Have function graph tracer define options per instance

2025-11-13T20:08:17+00:00

Currently the function graph tracer's options are saved via a global mask
when it should be per instance. Use the new infrastructure to define a
"default_flags" field in the tracer structure that is used for the top
level instance as well as new ones.

Currently the global mask causes confusion:

  # cd /sys/kernel/tracing
  # mkdir instances/foo
  # echo function_graph > instances/foo/current_tracer
  # echo 1 > options/funcgraph-args
  # echo function_graph > current_tracer
  # cat trace
[..]
 2)               |          _raw_spin_lock_irq(lock=0xffff96b97dea16c0) {
 2)   0.422 us    |            do_raw_spin_lock(lock=0xffff96b97dea16c0);
 7)               |              rcu_sched_clock_irq(user=0) {
 2)   1.478 us    |          }
 7)   0.758 us    |                rcu_is_cpu_rrupt_from_idle();
 2)   0.647 us    |          enqueue_hrtimer(timer=0xffff96b97dea2058, base=0xffff96b97dea1740, mode=0);
 # cat instances/foo/options/funcgraph-args
 1
 # cat instances/foo/trace
[..]
 4)               |  __x64_sys_read() {
 4)               |    ksys_read() {
 4)   0.755 us    |      fdget_pos();
 4)               |      vfs_read() {
 4)               |        rw_verify_area() {
 4)               |          security_file_permission() {
 4)               |            apparmor_file_permission() {
 4)               |              common_file_perm() {
 4)               |                aa_file_perm() {
 4)               |                  rcu_read_lock_held() {
[..]

The above shows that updating the "funcgraph-args" option at the top level
instance also updates the "funcgraph-args" option in the instance but
because the update is only done by the instance that gets changed (as it
should), it's confusing to see that the option is already set in the other
instance.

Cc: Masami Hiramatsu 
Cc: Mark Rutland 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://patch.msgid.link/20251111232429.641030027@kernel.org
Fixes: c132be2c4fcc1 ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Steven Rostedt (Google)

tracing: Allow tracer to add more than 32 options

2025-11-04T12:44:00+00:00

Since enum trace_iterator_flags is 32bit, the max number of the
option flags is limited to 32 and it is fully used now. To add
a new option, we need to expand it.

So replace the TRACE_ITER_##flag with TRACE_ITER(flag) macro which
is 64bit bitmask.

Link: https://lore.kernel.org/all/176187877103.994619.166076000668757232.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google)