From 5d16d833cfa1deac05df52d688d85da991b220e0 Mon Sep 17 00:00:00 2001 From: Gabriele Paoloni Date: Fri, 21 Mar 2025 18:08:21 +0100 Subject: [PATCH] tracing: fix return value in __ftrace_event_enable_disable for TRACE_REG_UNREGISTER [ Upstream commit 0c588ac0ca6c22b774d9ad4a6594681fdfa57d9d ] When __ftrace_event_enable_disable invokes the class callback to unregister the event, the return value is not reported up to the caller, hence leading to event unregister failures being silently ignored. This patch assigns the ret variable to the invocation of the event unregister callback, so that its return value is stored and reported to the caller, and it raises a warning in case of error. Link: https://lore.kernel.org/20250321170821.101403-1-gpaoloni@redhat.com Signed-off-by: Gabriele Paoloni Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin --- kernel/trace/trace_events.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 958789fe4cef..77df1e28fa32 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -405,7 +405,9 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file, clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags); } - call->class->reg(call, TRACE_REG_UNREGISTER, file); + ret = call->class->reg(call, TRACE_REG_UNREGISTER, file); + + WARN_ON_ONCE(ret); } /* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */ if (file->flags & EVENT_FILE_FL_SOFT_MODE)