From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH] KVM guest: prevent tracing recursion with kvmclock Date: Tue, 15 Nov 2011 15:01:15 +0200 Message-ID: <1321362075-27115-1-git-send-email-avi@redhat.com> Cc: Steven Rostedt To: kvm@vger.kernel.org, Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:16772 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750746Ab1KONB2 (ORCPT ); Tue, 15 Nov 2011 08:01:28 -0500 Sender: kvm-owner@vger.kernel.org List-ID: Stop tracing when we read the clock, since tracing will also want to read the clock, and recurse indefinitely. Based on a similar patch for Xen from Jeremy Fitzhardinge. Signed-off-by: Avi Kivity --- arch/x86/kernel/kvmclock.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index c1a0188..44842d7 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -74,9 +74,10 @@ static cycle_t kvm_clock_read(void) struct pvclock_vcpu_time_info *src; cycle_t ret; - src = &get_cpu_var(hv_clock); + preempt_disable_notrace(); + src = &__get_cpu_var(hv_clock); ret = pvclock_clocksource_read(src); - put_cpu_var(hv_clock); + preempt_enable_notrace(); return ret; } -- 1.7.7.1