From: Liao Chang <liaochang1@huawei.com>
Date: Fri, 24 Jan 2025 09:38:25 +0000 (+0000)
Subject: uprobes: Remove redundant spinlock in uprobe_deny_signal()
X-Git-Tag: v6.15-rc1~217^2~48
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=eae8a56ae0c74c1cf2f92a6709d215a9f329f60c;p=thirdparty%2Fkernel%2Flinux.git

uprobes: Remove redundant spinlock in uprobe_deny_signal()

Since clearing a bit in thread_info is an atomic operation, the spinlock
is redundant and can be removed, reducing lock contention is good for
performance.

Signed-off-by: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20250124093826.2123675-2-liaochang1@huawei.com
---

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 2ca797cbe465f..33bd6083f7c40 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -2302,9 +2302,7 @@ bool uprobe_deny_signal(void)
 	WARN_ON_ONCE(utask->state != UTASK_SSTEP);
 
 	if (task_sigpending(t)) {
-		spin_lock_irq(&t->sighand->siglock);
 		clear_tsk_thread_flag(t, TIF_SIGPENDING);
-		spin_unlock_irq(&t->sighand->siglock);
 
 		if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) {
 			utask->state = UTASK_SSTEP_TRAPPED;