From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752118AbdKHK7T (ORCPT ); Wed, 8 Nov 2017 05:59:19 -0500 Received: from terminus.zytor.com ([65.50.211.136]:56161 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750917AbdKHK7S (ORCPT ); Wed, 8 Nov 2017 05:59:18 -0500 Date: Wed, 8 Nov 2017 02:54:34 -0800 From: tip-bot for Frederic Weisbecker Message-ID: Cc: tj@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, tglx@linutronix.de, jiangshanlai@gmail.com, frederic@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, davem@davemloft.net, mingo@kernel.org Reply-To: peterz@infradead.org, torvalds@linux-foundation.org, tglx@linutronix.de, tj@kernel.org, linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, mingo@kernel.org, davem@davemloft.net, jiangshanlai@gmail.com, hpa@zytor.com, frederic@kernel.org In-Reply-To: <1509980490-4285-8-git-send-email-frederic@kernel.org> References: <1509980490-4285-8-git-send-email-frederic@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] x86: Use lockdep to assert IRQs are disabled/enabled Git-Commit-ID: 7a10e2a9190628a4024ea394ce7bd641ae40ffd1 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 7a10e2a9190628a4024ea394ce7bd641ae40ffd1 Gitweb: https://git.kernel.org/tip/7a10e2a9190628a4024ea394ce7bd641ae40ffd1 Author: Frederic Weisbecker AuthorDate: Mon, 6 Nov 2017 16:01:23 +0100 Committer: Ingo Molnar CommitDate: Wed, 8 Nov 2017 11:13:50 +0100 x86: Use lockdep to assert IRQs are disabled/enabled Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. It also makes no more sense to fix the IRQ flags when a bug is detected as the assertion is now pure config-dependent debugging. And to quote Peter Zijlstra: The whole if !disabled, disable logic is uber paranoid programming, but I don't think we've ever seen that WARN trigger, and if it does (and then burns the kernel) we at least know what happend. Signed-off-by: Frederic Weisbecker Acked-by: Thomas Gleixner Cc: David S . Miller Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Tejun Heo Link: http://lkml.kernel.org/r/1509980490-4285-8-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/entry/common.c | 4 +--- arch/x86/kernel/smpboot.c | 2 +- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index eaa0ba6..d7d3cc2 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -186,9 +186,7 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs) addr_limit_user_check(); - if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled())) - local_irq_disable(); - + lockdep_assert_irqs_disabled(); lockdep_sys_exit(); cached_flags = READ_ONCE(ti->flags); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 198416d..4008b6b 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1095,7 +1095,7 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle) unsigned long flags; int err, ret = 0; - WARN_ON(irqs_disabled()); + lockdep_assert_irqs_enabled(); pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);