From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751774AbaHAJrD (ORCPT ); Fri, 1 Aug 2014 05:47:03 -0400 Received: from e35.co.us.ibm.com ([32.97.110.153]:35222 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750738AbaHAJrB (ORCPT ); Fri, 1 Aug 2014 05:47:01 -0400 Date: Fri, 1 Aug 2014 15:18:44 +0530 From: Ananth N Mavinakayanahalli To: Masami Hiramatsu Cc: Ingo Molnar , linux-kernel@vger.kernel.org, "David S. Miller" Subject: Re: [PATCH -tip ] [BUGFIX] kprobes: Skip kretprobe hit in NMI context to avoid deadlock Message-ID: <20140801094844.GA4329@in.ibm.com> Reply-To: ananth@in.ibm.com References: <20140801084254.12330.64728.stgit@kbuild-fedora.novalocal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140801084254.12330.64728.stgit@kbuild-fedora.novalocal> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14080109-6688-0000-0000-000003B2AC1D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 01, 2014 at 08:42:54AM +0000, Masami Hiramatsu wrote: > Skip kretprobe hit in NMI context, because if an NMI happens > inside the critical section protected by kretprobe_table.lock > and another(or same) kretprobe hit, pre_kretprobe_handler > tries to lock kretprobe_table.lock again. > Normal interrupts have no problem because they are disabled > with the lock. > > Signed-off-by: Masami Hiramatsu Acked-by: Ananth N Mavinakayanahalli