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authorsunliming <sunliming@kylinos.cn>2023-06-06 14:20:24 +0800
committerSteven Rostedt (Google) <rostedt@goodmis.org>2023-06-14 12:41:52 -0400
commit6f05dcabe5c241d066ec472cf38ac8b84f8c9c6f (patch)
tree7c744fd135f87dc8819c77ef9b995ca52ee9aa88 /kernel/trace/trace_events_user.c
parente70bb54d7a51299e7feca9169c07d79f9a3fc01d (diff)
tracing/user_events: Fix the incorrect trace record for empty arguments events
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>
Diffstat (limited to 'kernel/trace/trace_events_user.c')
-rw-r--r--kernel/trace/trace_events_user.c4
1 files changed, 2 insertions, 2 deletions
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) &&