This is a note to let you know that I've just added the patch titled
tracing: Check pid filtering when creating events
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracing-check-pid-filtering-when-creating-events.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6cb206508b621a9a0a2c35b60540e399225c8243 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
Date: Fri, 26 Nov 2021 13:35:26 -0500
Subject: tracing: Check pid filtering when creating events
From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
commit 6cb206508b621a9a0a2c35b60540e399225c8243 upstream.
When pid filtering is activated in an instance, all of the events trace
files for that instance has the PID_FILTER flag set. This determines
whether or not pid filtering needs to be done on the event, otherwise the
event is executed as normal.
If pid filtering is enabled when an event is created (via a dynamic event
or modules), its flag is not updated to reflect the current state, and the
events are not filtered properly.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 3fdaf80f4a836 ("tracing: Implement event pid filtering")
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/trace_events.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2255,12 +2255,19 @@ static struct trace_event_file *
trace_create_new_event(struct trace_event_call *call,
struct trace_array *tr)
{
+ struct trace_pid_list *pid_list;
struct trace_event_file *file;
file = kmem_cache_alloc(file_cachep, GFP_TRACE);
if (!file)
return NULL;
+ pid_list = rcu_dereference_protected(tr->filtered_pids,
+ lockdep_is_held(&event_mutex));
+
+ if (pid_list)
+ file->flags |= EVENT_FILE_FL_PID_FILTER;
+
file->event_call = call;
file->tr = tr;
atomic_set(&file->sm_ref, 0);
Patches currently in stable-queue which might be from rostedt@xxxxxxxxxxx are
queue-4.19/tracing-check-pid-filtering-when-creating-events.patch
queue-4.19/tracing-fix-pid-filtering-when-triggers-are-attached.patch
