From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 27 Oct 2025 08:44:31 +0000 (+0100)
Subject: rseq: Avoid CPU/MM CID updates when no event pending
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=566d8015f7eef11d82cd63dc4e1f620fcfc2a394;p=thirdparty%2Flinux.git

rseq: Avoid CPU/MM CID updates when no event pending

There is no need to update these values unconditionally if there is no
event pending.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251027084306.462964916@linutronix.de
---

diff --git a/kernel/rseq.c b/kernel/rseq.c
index 01e711383e052..81dddafa2f2e7 100644
--- a/kernel/rseq.c
+++ b/kernel/rseq.c
@@ -464,11 +464,12 @@ void __rseq_handle_notify_resume(struct ksignal *ksig, struct pt_regs *regs)
 		t->rseq_event_pending = false;
 	}
 
-	if (IS_ENABLED(CONFIG_DEBUG_RSEQ) || event) {
-		ret = rseq_ip_fixup(regs, event);
-		if (unlikely(ret < 0))
-			goto error;
-	}
+	if (!IS_ENABLED(CONFIG_DEBUG_RSEQ) && !event)
+		return;
+
+	ret = rseq_ip_fixup(regs, event);
+	if (unlikely(ret < 0))
+		goto error;
 
 	if (unlikely(rseq_update_cpu_node_id(t)))
 		goto error;