Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755003Ab3JITJf (ORCPT ); Wed, 9 Oct 2013 15:09:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28312 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752357Ab3JITJe (ORCPT ); Wed, 9 Oct 2013 15:09:34 -0400 Date: Wed, 9 Oct 2013 21:08:51 +0200 From: Jakub Jelinek To: Peter Zijlstra Cc: Oleg Nesterov , Fengguang Wu , Linus Torvalds , Ingo Molnar , Linux Kernel Mailing List , Richard Henderson Subject: Re: [x86] BUG: unable to handle kernel paging request at 00740060 Message-ID: <20131009190851.GX30970@tucnak.zalov.cz> Reply-To: Jakub Jelinek References: <20131005234430.GA22485@localhost> <20131008143400.GA14721@redhat.com> <20131009080459.GA2298@localhost> <20131009124310.GA11769@redhat.com> <20131009140734.GH3081@twins.programming.kicks-ass.net> <20131009143359.GU26785@twins.programming.kicks-ass.net> <20131009144656.GV26785@twins.programming.kicks-ass.net> <20131009181613.GW30970@tucnak.zalov.cz> <20131009190231.GI13848@laptop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131009190231.GI13848@laptop.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1035 Lines: 22 On Wed, Oct 09, 2013 at 09:02:31PM +0200, Peter Zijlstra wrote: > On Wed, Oct 09, 2013 at 08:16:13PM +0200, Jakub Jelinek wrote: > > Confirmed as gcc bug, filed http://gcc.gnu.org/PR58670 > > Seems all of 4.[6-9] miscompile it. Will have a look tomorrow > > unless somebody beats me to it. But historically, the case where > > asm goto labels jump to fallthru basic block had numerous problems in the > > past. > > That bug lists the component as middle end; this suggests x86_64 would > be vulnerable too, can you confirm? So far we've only observed the wrong > code on i386 targets, x86_64 targets appeared correct. Any target, the testcase in the bugzilla aborts on x86_64 with -O2, and even say on ppc64 (sure, one would have to rewrite the asm to have it fail at runtime). Jakub -- 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/