From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754599Ab0K3W17 (ORCPT ); Tue, 30 Nov 2010 17:27:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:11682 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753999Ab0K3W15 (ORCPT ); Tue, 30 Nov 2010 17:27:57 -0500 From: Don Zickus To: Ingo Molnar Cc: Peter Zijlstra , Robert Richter , ying.huang@intel.com, Andi Kleen , gorcunov@gmail.com, LKML , Don Zickus Subject: [PATCH 6/9] x86: only call smp_processor_id in non-preempt cases Date: Tue, 30 Nov 2010 17:27:27 -0500 Message-Id: <1291156050-4482-7-git-send-email-dzickus@redhat.com> In-Reply-To: <1291156050-4482-1-git-send-email-dzickus@redhat.com> References: <1291156050-4482-1-git-send-email-dzickus@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are some paths that walk the die_chain with preemption on. Make sure we are in an NMI call before we start doing anything. This was triggered by do_general_protection calling notify_die with DIE_GPF. Reported-by: Jan Kiszka Signed-off-by: Don Zickus --- arch/x86/kernel/apic/hw_nmi.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c index 82bff25..ddb29bf 100644 --- a/arch/x86/kernel/apic/hw_nmi.c +++ b/arch/x86/kernel/apic/hw_nmi.c @@ -59,7 +59,7 @@ arch_trigger_all_cpu_backtrace_handler(struct notifier_block *self, { struct die_args *args = __args; struct pt_regs *regs; - int cpu = smp_processor_id(); + int cpu; switch (cmd) { case DIE_NMI: @@ -70,6 +70,7 @@ arch_trigger_all_cpu_backtrace_handler(struct notifier_block *self, } regs = args->regs; + cpu = smp_processor_id(); if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) { static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED; -- 1.7.3.2