From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753597AbcFOIyD (ORCPT ); Wed, 15 Jun 2016 04:54:03 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:33628 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752656AbcFOIx7 (ORCPT ); Wed, 15 Jun 2016 04:53:59 -0400 From: WANG Chao To: Ingo Molnar , Peter Zijlstra Cc: linux-kernel@vger.kernel.org Subject: [PATCH v3] sched: unlikely corrupted stack end Date: Wed, 15 Jun 2016 16:53:50 +0800 Message-Id: <20160615085350.32777-1-wcwxyz@gmail.com> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20160615082554.GA18748@gmail.com> References: <20160615082554.GA18748@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org unlikely() was dropped in commit ce03e4137bb2 ("sched/core: Drop unlikely behind BUG_ON()"), but commit 29d6455178a0 ("sched: panic on corrupted stack end") dropped BUG_ON() and called panic directly. Now we should bring unlikely() back for branch prediction. While we're at it, it's better and cleaner to add unlikely() to task_stack_end_corrupted() macro. Signed-off-by: WANG Chao --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 6e42ada26345..74a02bf30827 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2998,7 +2998,7 @@ static inline unsigned long *end_of_stack(struct task_struct *p) #endif #define task_stack_end_corrupted(task) \ - (*(end_of_stack(task)) != STACK_END_MAGIC) + (unlikely(*(end_of_stack(task)) != STACK_END_MAGIC)) static inline int object_is_on_stack(void *obj) { -- 2.9.0