Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755649Ab3JJIFq (ORCPT ); Thu, 10 Oct 2013 04:05:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12130 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755281Ab3JJIFm (ORCPT ); Thu, 10 Oct 2013 04:05:42 -0400 Date: Thu, 10 Oct 2013 10:04:57 +0200 From: Jakub Jelinek To: Ingo Molnar Cc: Peter Zijlstra , Oleg Nesterov , Fengguang Wu , Linus Torvalds , Linux Kernel Mailing List , Richard Henderson Subject: Re: [x86] BUG: unable to handle kernel paging request at 00740060 Message-ID: <20131010080457.GC21875@tucnak.zalov.cz> Reply-To: Jakub Jelinek References: <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> <20131009190851.GX30970@tucnak.zalov.cz> <20131010062238.GB9853@gmail.com> <20131010065104.GY30970@tucnak.zalov.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131010065104.GY30970@tucnak.zalov.cz> 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: 815 Lines: 24 On Thu, Oct 10, 2013 at 08:51:04AM +0200, Jakub Jelinek wrote: > @@ -8,6 +8,7 @@ foo (int a, int b) > asm volatile goto ("bts $1, %0; jc %l[lab]" : : "m" (b) : "memory" : lab); > return 0; > lab: > + asm (""); > return 0; > } Or alternatively put the asm (""); right after asm goto, asm volatile goto ("bts $1, %0; jc %l[lab]" : : "m" (b) : "memory" : lab); asm (""); return ...; lab; return ...; What generates better code remains to be tested. In any case, please conditionalize the hacks on non-fixed compilers once the fix is released. 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/