tracing/user_events: Fix incorrect return value for writing operation when events...

The writing operation return the count of writes regardless of whether events
are enabled or disabled. Switch it to return -EBADF to indicates that the event
is disabled.

Link: https://lkml.kernel.org/r/20230626111344.19136-2-sunliming@kylinos.cn
Cc: stable@vger.kernel.org
7f5a08c79df35 ("user_events: Add minimal support for trace_event into ftrace")
Acked-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 8df0550..09f7d91 100644 (file)
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -2096,7 +2096,8 @@ static ssize_t user_events_write_core(struct file *file, struct iov_iter *i)
 
                if (unlikely(faulted))
                        return -EFAULT;
-       }
+       } else
+               return -EBADF;
 
        return ret;
 }