trace: use override credential guard

Use override credential guards for scoped credential override with
automatic restoration on scope exit.

Link: https://patch.msgid.link/20251103-work-creds-guards-prepare_creds-v1-12-b447b82f2c9b@kernel.org
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 28c62149eec52212819637c2ed64819630f4369d..b15854c75d4fbd28ef12da218b933de7437d3384 100644 (file)
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1449,9 +1449,6 @@ static struct trace_event_functions user_event_funcs = {
 
 static int user_event_set_call_visible(struct user_event *user, bool visible)
 {
-       int ret;
-       const struct cred *old_cred;
-
        CLASS(prepare_creds, cred)();
        if (!cred)
                return -ENOMEM;
@@ -1467,16 +1464,12 @@ static int user_event_set_call_visible(struct user_event *user, bool visible)
         */
        cred->fsuid = GLOBAL_ROOT_UID;
 
-       old_cred = override_creds(cred);
-
-       if (visible)
-               ret = trace_add_event_call(&user->call);
-       else
-               ret = trace_remove_event_call(&user->call);
+       scoped_with_creds(cred) {
+               if (visible)
+                       return trace_add_event_call(&user->call);
 
-       revert_creds(old_cred);
-
-       return ret;
+               return trace_remove_event_call(&user->call);
+       }
 }
 
 static int destroy_user_event(struct user_event *user)