4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> commit 0958b33ef5a04ed91f61cef4760ac412080c4e08 upstream. Fix register_snapshot_trigger() to return error code if it failed to allocate a snapshot instead of 0 (success). Unless that, it will register snapshot trigger without an error. Link: https://lore.kernel.org/linux-trace-kernel/170622977792.270660.2789298642759362200.stgit@devnote2 Fixes: 0bbe7f719985 ("tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation") Cc: stable@xxxxxxxxxxxxxxx Cc: Vincent Donnefort <vdonnefort@xxxxxxxxxx> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/trace_events_trigger.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1133,8 +1133,10 @@ register_snapshot_trigger(char *glob, st struct event_trigger_data *data, struct trace_event_file *file) { - if (tracing_alloc_snapshot_instance(file->tr) != 0) - return 0; + int ret = tracing_alloc_snapshot_instance(file->tr); + + if (ret < 0) + return ret; return register_trigger(glob, ops, data, file); }
