From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:60941) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UXamv-0004at-GT for qemu-devel@nongnu.org; Wed, 01 May 2013 13:25:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UXamu-00080H-1V for qemu-devel@nongnu.org; Wed, 01 May 2013 13:25:53 -0400 Received: from e24smtp04.br.ibm.com ([32.104.18.25]:45621) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UXamt-000805-GN for qemu-devel@nongnu.org; Wed, 01 May 2013 13:25:51 -0400 Received: from /spool/local by e24smtp04.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 1 May 2013 14:25:48 -0300 Received: from d24relay01.br.ibm.com (d24relay01.br.ibm.com [9.8.31.16]) by d24dlp02.br.ibm.com (Postfix) with ESMTP id A72C11DC006A for ; Wed, 1 May 2013 13:25:45 -0400 (EDT) Received: from d24av02.br.ibm.com (d24av02.br.ibm.com [9.8.31.93]) by d24relay01.br.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r41HMuXH2424842 for ; Wed, 1 May 2013 14:22:57 -0300 Received: from d24av02.br.ibm.com (loopback [127.0.0.1]) by d24av02.br.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r41HPiI8019870 for ; Wed, 1 May 2013 14:25:44 -0300 Message-ID: <51815017.50909@linux.vnet.ibm.com> Date: Wed, 01 May 2013 14:25:43 -0300 From: Eduardo Otubo MIME-Version: 1.0 References: <517AC9E5.3050204@linux.vnet.ibm.com> <7515044.dYPbKXmJQB@sifl> <517EEB8A.7040700@linux.vnet.ibm.com> <3720772.nm306DgS3l@sifl> In-Reply-To: <3720772.nm306DgS3l@sifl> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC] Continuous work on sandboxing List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Moore Cc: Paolo Bonzini , Corey Bryant , qemu-devel@nongnu.org, Eric Paris On 04/30/2013 12:24 PM, Paul Moore wrote: > On Monday, April 29, 2013 05:52:10 PM Corey Bryant wrote: >> On 04/26/2013 05:07 PM, Paul Moore wrote: >>> [snip] >>> >>>>> 3. Debugging and/or learning mode - third party libraries still have the >>>>> problem of interfering in the Qemu's signal mask. According to some >>>>> previous discussions, perhaps patch all external libraries that mass up >>>>> with this mask (spice, for example) is a way to solve it. But not sure >>>>> if it worth the time spent. Would like to hear you guys. >>> >>> I think patching all the libraries is a losing battle, I think we need to >>> pursue alternate debugging techniques. >> >> I agree. It would be nice to have some sort of learning mode that >> reported all denied syscalls on a single run, but signal handlers >> doesn't seem like the right way. Maybe we could improve on this >> approach, since it never gained traction: https://lkml.org/lkml/2013/1/7/313 >> >> At least we can get a single denied syscall at a time today via the >> audit log that the kernel issues. Eduardo, you may want to see if >> there's a good place to document that for QEMU so that people know where >> to look. > > Lately I've been using the fact that the seccomp BPF filter result generates > an audit log; it either dumps to syslog or the audit log (depending on your > configuration) and seems to accomplish most of what we wanted with > SECCOMP_RET_INFO. > > I'm always open to new/better ideas, but this has been working reasonably well > for me for the past few months. I think this feature would fits well on Qemu if we could have a "normal" signal handling. But external libraries interfere a lot on this matter. Paolo, am I the first one to complain about signal handling on Qemu (being interfered by other libraries)? I believe this may cause some trouble in other parts of the project as well. Wouldn't be this a good time to, perhaps, just think about a signal handling refactoring? Regards, -- Eduardo Otubo IBM Linux Technology Center