tracing: Dump stacktrace trigger to the corresponding instance

commit ce33c845b030c9cf768370c951bc699470b09fa7 upstream.

The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.

Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org
Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 33c66fac1a31d33c8e5d65e5d1e72c7905c14e00..40c1a2dd48f0f317535ce068eb694941a33f953b 100644 (file)
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1196,7 +1196,14 @@ static __init int register_trigger_snapshot_cmd(void) { return 0; }
 static void
 stacktrace_trigger(struct event_trigger_data *data, void *rec)
 {
-       trace_dump_stack(STACK_SKIP);
+       struct trace_event_file *file = data->private_data;
+       unsigned long flags;
+
+       if (file) {
+               local_save_flags(flags);
+               __trace_stack(file->tr, flags, STACK_SKIP, preempt_count());
+       } else
+               trace_dump_stack(STACK_SKIP);
 }
 
 static void