From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757389Ab1EKQYZ (ORCPT ); Wed, 11 May 2011 12:24:25 -0400 Received: from hera.kernel.org ([140.211.167.34]:54372 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932410Ab1EKQQs (ORCPT ); Wed, 11 May 2011 12:16:48 -0400 Date: Wed, 11 May 2011 13:10:01 GMT From: tip-bot for Jiri Olsa Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, masami.hiramatsu.pt@hitachi.com, tglx@linutronix.de, mingo@elte.hu, jolsa@redhat.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, masami.hiramatsu.pt@hitachi.com, tglx@linutronix.de, jolsa@redhat.com, mingo@elte.hu In-Reply-To: <20110511110613.GB2390@jolsa.brq.redhat.com> References: <20110511110613.GB2390@jolsa.brq.redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] kprobes, x86: Disable irqs during optimized callback Git-Commit-ID: 9bbeacf52f66d165739a4bbe9c018d17493a74b5 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Wed, 11 May 2011 13:10:02 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 9bbeacf52f66d165739a4bbe9c018d17493a74b5 Gitweb: http://git.kernel.org/tip/9bbeacf52f66d165739a4bbe9c018d17493a74b5 Author: Jiri Olsa AuthorDate: Wed, 11 May 2011 13:06:13 +0200 Committer: Ingo Molnar CommitDate: Wed, 11 May 2011 13:21:23 +0200 kprobes, x86: Disable irqs during optimized callback Disable irqs during optimized callback, so we dont miss any in-irq kprobes. The following commands: # cd /debug/tracing/ # echo "p mutex_unlock" >> kprobe_events # echo "p _raw_spin_lock" >> kprobe_events # echo "p smp_apic_timer_interrupt" >> ./kprobe_events # echo 1 > events/enable Cause the optimized kprobes to be missed. None is missed with the fix applied. Signed-off-by: Jiri Olsa Acked-by: Masami Hiramatsu Link: http://lkml.kernel.org/r/20110511110613.GB2390@jolsa.brq.redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/kprobes.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index c969fd9..f1a6244 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -1183,12 +1183,13 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + unsigned long flags; /* This is possible if op is under delayed unoptimizing */ if (kprobe_disabled(&op->kp)) return; - preempt_disable(); + local_irq_save(flags); if (kprobe_running()) { kprobes_inc_nmissed_count(&op->kp); } else { @@ -1207,7 +1208,7 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op, opt_pre_handler(&op->kp, regs); __this_cpu_write(current_kprobe, NULL); } - preempt_enable_no_resched(); + local_irq_restore(flags); } static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src)