From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: Fri, 26 Jan 2024 09:42:58 +0900
Subject: tracing/trigger: Fix to return error if failed to alloc snapshot
Git-commit: 0958b33ef5a04ed91f61cef4760ac412080c4e08
Patch-mainline: v6.8 or v6.8-rc3 (next release)
References: git-fixes
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@vger.kernel.org
Cc: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Petr Pavlu <petr.pavlu@suse.com>
---
kernel/trace/trace_events_trigger.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 46439e3bcec4..b33c3861fbbb 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1470,8 +1470,10 @@ register_snapshot_trigger(char *glob,
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);
}