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 d0309de2f84fea5bfce5cbe4a8321be92c547057..4bc90965abb25f0cedd6c1cd3319377aa1b18dc2 100644 (file)
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1219,7 +1219,14 @@ static void
 stacktrace_trigger(struct event_trigger_data *data, void *rec,
                   struct ring_buffer_event *event)
 {
-       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