From: Steven Rostedt <rostedt@goodmis.org>
Date: Mon, 28 Oct 2024 07:12:29 +0000 (-0400)
Subject: fgraph: Use guard(mutex)(&ftrace_lock) for unregister_ftrace_graph()
X-Git-Tag: v6.13-rc1~163^2~5
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6348a3fa723a4fa2e5651b0b93fbcddd5293e92b;p=thirdparty%2Fkernel%2Flinux.git

fgraph: Use guard(mutex)(&ftrace_lock) for unregister_ftrace_graph()

The ftrace_lock is held throughout unregister_ftrace_graph(), use a guard
to simplify the error paths.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20241028071307.770550792@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---

diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 001abf376c0c2..0bf78517b5d4c 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -1381,17 +1381,17 @@ void unregister_ftrace_graph(struct fgraph_ops *gops)
 {
 	int command = 0;
 
-	mutex_lock(&ftrace_lock);
+	guard(mutex)(&ftrace_lock);
 
 	if (unlikely(!ftrace_graph_active))
-		goto out;
+		return;
 
 	if (unlikely(gops->idx < 0 || gops->idx >= FGRAPH_ARRAY_SIZE ||
 		     fgraph_array[gops->idx] != gops))
-		goto out;
+		return;
 
 	if (fgraph_lru_release_index(gops->idx) < 0)
-		goto out;
+		return;
 
 	fgraph_array[gops->idx] = &fgraph_stub;
 
@@ -1413,7 +1413,5 @@ void unregister_ftrace_graph(struct fgraph_ops *gops)
 		unregister_pm_notifier(&ftrace_suspend_notifier);
 		unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL);
 	}
- out:
 	gops->saved_func = NULL;
-	mutex_unlock(&ftrace_lock);
 }