5.4-stable review patch. If anyone has any objections, please let me know.
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From: Gabriele Paoloni gpaoloni@redhat.com
[ 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 gpaoloni@redhat.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 958789fe4cef7..77df1e28fa329 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)