From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755371Ab1DZNBt (ORCPT ); Tue, 26 Apr 2011 09:01:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10756 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754929Ab1DZNBs (ORCPT ); Tue, 26 Apr 2011 09:01:48 -0400 From: Jiri Olsa To: masami.hiramatsu.pt@hitachi.com Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, Jiri Olsa Subject: [PATCH] kprobes,x86: disable irq durinr optimized callback Date: Tue, 26 Apr 2011 15:01:31 +0200 Message-Id: <1303822891-8450-1-git-send-email-jolsa@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org hi, attached patch is disabling irqs during optimized callback, so we dont miss any in-irq kprobes as missed. Also I think there's small window where current_kprobe variable could be touched in non-safe way, but I was not able to hit any issue. I'm not sure wether this is a bug or if it was intentional to have irqs enabled during the pre_handler callback. wbr, jirka --- Disabling irqs during optimized callback, so we dont miss any in-irq kprobes as missed. Interrupts are also disabled during non-optimized kprobes callbacks. Signed-off-by: Jiri Olsa --- arch/x86/kernel/kprobes.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index c969fd9..917cb31 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -1183,11 +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; + local_irq_save(flags); preempt_disable(); if (kprobe_running()) { kprobes_inc_nmissed_count(&op->kp); @@ -1208,6 +1210,7 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op, __this_cpu_write(current_kprobe, NULL); } preempt_enable_no_resched(); + local_irq_restore(flags); } static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src) -- 1.7.1