FAILED: patch "[PATCH] tracing: Dump stacktrace trigger to the corresponding" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ce33c845b030c9cf768370c951bc699470b09fa7 Mon Sep 17 00:00:00 2001
From: Daniel Bristot de Oliveira <[email protected]>
Date: Sun, 20 Feb 2022 23:49:57 +0100
Subject: [PATCH] tracing: Dump stacktrace trigger to the corresponding
instance

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.

index d00fee705f9c..e0d50c9577f3 100644
@@ -1540,7 +1540,12 @@ stacktrace_trigger(struct event_trigger_data *data,
 		   struct trace_buffer *buffer,  void *rec,
 		   struct ring_buffer_event *event)
 {
-	trace_dump_stack(STACK_SKIP);
+	struct trace_event_file *file = data->private_data;
+
+	if (file)
+		__trace_stack(file->tr, tracing_gen_ctx(), STACK_SKIP);
+	else
+		trace_dump_stack(STACK_SKIP);
 }
 
 static void

The following should work for 4.14. Again, 4.9 and earlier requires a lot more work than I have time for.

-- Steve

From: Daniel Bristot de Oliveira <[email protected]>
Date: Sun, 20 Feb 2022 23:49:57 +0100
Subject: [PATCH] tracing: Dump stacktrace trigger to the corresponding
instance

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.

---
 kernel/trace/trace_events_trigger.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

Index: linux-test.git/kernel/trace/trace_events_trigger.c
===================================================================
@@ -1156,7 +1156,14 @@ static __init int register_trigger_snaps
 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

All now queued up, thanks.

greg k-h