Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756205Ab0GMOTH (ORCPT ); Tue, 13 Jul 2010 10:19:07 -0400 Received: from anguilla.debian.or.at ([86.59.21.37]:40962 "EHLO anguilla.debian.or.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752460Ab0GMOTF (ORCPT ); Tue, 13 Jul 2010 10:19:05 -0400 Date: Tue, 13 Jul 2010 16:19:02 +0200 From: Peter Palfrader To: Avi Kivity Cc: Greg KH , linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Glauber Costa , Zachary Amsden , Jeremy Fitzhardinge , Marcelo Tosatti Subject: Re: [patch 134/149] x86, paravirt: Add a global synchronization point for pvclock Message-ID: <20100713141902.GB15122@anguilla.noreply.org> Mail-Followup-To: Peter Palfrader , Avi Kivity , Greg KH , linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Glauber Costa , Zachary Amsden , Jeremy Fitzhardinge , Marcelo Tosatti References: <20100701175144.GA2116@kroah.com> <20100701173218.125822294@clark.site> <20100707124731.GJ15122@anguilla.noreply.org> <4C359D5A.1050906@redhat.com> <20100713102350.GW15122@anguilla.noreply.org> <4C3C68C8.4060409@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <4C3C68C8.4060409@redhat.com> X-PGP: 1024D/94C09C7F 5B00 C96D 5D54 AEE1 206B AF84 DE7A AF6E 94C0 9C7F X-Request-PGP: http://www.palfrader.org/keys/94C09C7F.asc X-Accept-Language: de, en User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1620 Lines: 40 On Tue, 13 Jul 2010, Avi Kivity wrote: >> BUG: unable to handle kernel paging request at ffffffff81712e80 >> IP: [] pvclock_clocksource_read+0x83/0xc0 >> PGD 1003067 PUD 1007063 PMD 7e8b1063 PTE 8000000001712161 > Read-only pte >> Oops: 0003 [#2] SMP > Write fault. >> Code: 78 4f 44 89 e1 48 d3 e0 44 89 f2 48 f7 e2 48 0f ac d0 20 4a 8d 0c 38 44 39 03 75 a4 48 8b 15 15 df 6b 00 48 39 ca 77 17 48 89 d0 48 0f b1 0d 04 df 6b 00 48 39 c1 48 89 c2 75 e7 48 89 ca 48 >> RIP [] pvclock_clocksource_read+0x83/0xc0 > --> lock cmpxchg %rcx,0x6bdf04(%rip) >> static atomic64_t last_value = ATOMIC64_INIT(0); >> >> cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src) >> last = atomic64_cmpxchg(&last_value, last, ret); > So it looks like last_value was placed in a read only section. Please > post your System.map somewhere. weasel@intrepid:~$ publish System.map http://asteria.noreply.org/~weasel/volatile/2010-07-13-mbm2xEdd8Q4/System.map weasel@intrepid:~$ grep -i last_value System.map ffffffff81712e80 r last_value ffffffff81b05240 b last_value.26163 Cheers, Peter -- | .''`. ** Debian GNU/Linux ** Peter Palfrader | : :' : The universal http://www.palfrader.org/ | `. `' Operating System | `- http://www.debian.org/ -- 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/