From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:32811) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UZkAJ-0001qb-3g for qemu-devel@nongnu.org; Tue, 07 May 2013 11:50:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UZkAG-0000hW-Tw for qemu-devel@nongnu.org; Tue, 07 May 2013 11:50:54 -0400 Received: from hall.aurel32.net ([2001:470:1f15:c4f::1]:52127) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UZkAG-0000hD-KG for qemu-devel@nongnu.org; Tue, 07 May 2013 11:50:52 -0400 Date: Tue, 7 May 2013 17:50:48 +0200 From: Aurelien Jarno Message-ID: <20130507155048.GN5000@ohm.aurel32.net> References: <8661yvqasu.fsf@shell.gmplib.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <8661yvqasu.fsf@shell.gmplib.org> Subject: Re: [Qemu-devel] Reporting Heisenbugs in qemu List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Torbjorn Granlund Cc: qemu-devel@nongnu.org On Tue, May 07, 2013 at 01:38:57PM +0200, Torbjorn Granlund wrote: > I am trying to use qemu to > > 1. cover more of the assembly code in GMP > 2. check configuration logic of GMP > > but I am not as successful as I would like to be. > > The 2nd table of http://gmplib.org/devel/testsystems.html shows all > emulated systems I am using, most of which are qemu-based. > > Unfortunately, several of the qemu-based systems experience intermittent > but common segfaults: > > 1. Linux mips64eb 2.6.32-5-5kc-malta #1 Sun Sep 23 12:29:36 UTC 2012 mips64 GNU/Linux > 2. Linux mips64el 2.6.32-5-5kc-malta #1 Fri Feb 15 21:38:11 UTC 2013 mips64 GNU/Linux > 3. Linux kick.gmplib.org 2.6.18-6-sparc32 #1 Sat Dec 27 09:13:12 UTC 2008 sparc GNU/Linux > > An example of a failure is: > > gmp/tests/cxx/t-ops2.cc: In function 'void checkz()': > gmp/tests/cxx/t-ops2.cc:86: internal compiler error: Segmentation fault > Please submit a full bug report, > with preprocessed source if appropriate. > See for instructions. > For Debian GNU/Linux specific bug reporting instructions, > see . > The bug is not reproducible, so it is likely a hardware or OS problem. > > (This was from the sparc32 system.) > > rootrem.c: In function 'mpn_rootrem_internal': > rootrem.c:120:1: internal compiler error: Segmentation fault > Please submit a full bug report, > with preprocessed source if appropriate. > See for instructions. > The bug is not reproducible, so it is likely a hardware or OS problem. > > (From the mips64eb system.) > > I am aware of that these systems don't exactly use the > kernel-of-the-week. Newer kernels I have tried cause non-boot. (I > don't think I've tried any newer sparc kernel, as building that would > require a stable sparc system...) > > I realise that linux might have been debugged until it works on real > hardware, but that qemu might trigger untested linux execution paths. > > Yesterday, I disabled GMP testing on these qemu systems, as I got tired > of the many false alarms, and since GMP looked bad. Is there any hope > that these qemu systems will become stable? Or aren't these problems > qemu's fault? > Which version of QEMU are you using? This looks like a bug that has appeared in version 1.3.0 and fixed in version 1.4.1. The corresponding commit in master is 52ae646d4a3ebdcdcc973492c6a56f2c49b6578f -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurelien@aurel32.net http://www.aurel32.net