diff mbox series

[for-linus,05/15] tracing/user_events: Fix the incorrect trace record for empty arguments events

Message ID 20230615133415.683635706@goodmis.org
State New
Headers
Series tracing: Updates for 6.4 |

Commit Message

Steven Rostedt June 15, 2023, 1:05 p.m. UTC 
  From: sunliming <sunliming@kylinos.cn>

The user_events support events that has empty arguments. But the trace event
is discarded and not really committed when the arguments is empty. Fix this
by not attempting to copy in zero-length data.

Link: https://lkml.kernel.org/r/20230606062027.1008398-2-sunliming@kylinos.cn

Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_user.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index afe61dc86543..49914b6cb651 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1432,7 +1432,7 @@  static void user_event_ftrace(struct user_event *user, struct iov_iter *i,
 	if (unlikely(!entry))
 		return;
 
-	if (unlikely(!copy_nofault(entry + 1, i->count, i)))
+	if (unlikely(i->count != 0 && !copy_nofault(entry + 1, i->count, i)))
 		goto discard;
 
 	if (!list_empty(&user->validators) &&
@@ -1473,7 +1473,7 @@  static void user_event_perf(struct user_event *user, struct iov_iter *i,
 
 		perf_fetch_caller_regs(regs);
 
-		if (unlikely(!copy_nofault(perf_entry + 1, i->count, i)))
+		if (unlikely(i->count != 0 && !copy_nofault(perf_entry + 1, i->count, i)))
 			goto discard;
 
 		if (!list_empty(&user->validators) &&