Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760398AbYAVBHv (ORCPT ); Mon, 21 Jan 2008 20:07:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757454AbYAVBHm (ORCPT ); Mon, 21 Jan 2008 20:07:42 -0500 Received: from mga02.intel.com ([134.134.136.20]:11196 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757498AbYAVBHl (ORCPT ); Mon, 21 Jan 2008 20:07:41 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.25,230,1199692800"; d="scan'208";a="254624552" Subject: Re: [PATCH]Fix the order of atomic operations in restore_previous_kprobes on ia64 From: Shaohua Li To: Masami Hiramatsu Cc: "Luck, Tony" , ia64 , LKML , systemtap-ml In-Reply-To: <4790D1DE.8030700@redhat.com> References: <4790D1DE.8030700@redhat.com> Content-Type: text/plain Date: Tue, 22 Jan 2008 09:07:46 +0800 Message-Id: <1200964066.1353.0.camel@sli10-desk.sh.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1757 Lines: 48 On Sat, 2008-01-19 at 00:20 +0800, Masami Hiramatsu wrote: > From: Masami Hiramatsu > > Fix the order of atomic operations to prevent overwriting > prev_kprobe[0]. > To pop values from stack, we must decrement stack index right AFTER > reading values. > > Signed-off-by: Masami Hiramatsu > --- > Details of this issue was reported to > http://sources.redhat.com/bugzilla/show_bug.cgi?id=2071 > > arch/ia64/kernel/kprobes.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > Index: 2.6.24-rc8/arch/ia64/kernel/kprobes.c > =================================================================== > --- 2.6.24-rc8.orig/arch/ia64/kernel/kprobes.c 2008-01-17 > 21:14:01.000000000 -0500 > +++ 2.6.24-rc8/arch/ia64/kernel/kprobes.c 2008-01-17 > 21:14:01.000000000 -0500 > @@ -381,9 +381,10 @@ > static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk > *kcb) > { > unsigned int i; > - i = atomic_sub_return(1, &kcb->prev_kprobe_index); > - __get_cpu_var(current_kprobe) = kcb->prev_kprobe[i].kp; > - kcb->kprobe_status = kcb->prev_kprobe[i].status; > + i = atomic_read(&kcb->prev_kprobe_index); > + __get_cpu_var(current_kprobe) = kcb->prev_kprobe[i-1].kp; > + kcb->kprobe_status = kcb->prev_kprobe[i-1].status; > + atomic_sub(1, &kcb->prev_kprobe_index); > } > > static void __kprobes set_current_kprobe(struct kprobe *p, Acked. Thanks for the patch. Thanks, Shaohua -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/