From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: Re: fuzz testing an ext4fs file system under a 32 bit Linux user mode linux guest let task jbd2/ubda hang Date: Sun, 3 Aug 2014 14:42:10 -0400 Message-ID: <20140803184210.GV24826@thunk.org> References: <53DE3E92.3060304@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-ext4@vger.kernel.org, UML devel To: Toralf =?iso-8859-1?Q?F=F6rster?= Return-path: Received: from imap.thunk.org ([74.207.234.97]:42408 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751562AbaHCSxK (ORCPT ); Sun, 3 Aug 2014 14:53:10 -0400 Content-Disposition: inline In-Reply-To: <53DE3E92.3060304@gmx.de> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Sun, Aug 03, 2014 at 03:52:18PM +0200, Toralf F=F6rster wrote: > Hello, >=20 > fuzzying a 32 bit stable Gentoo x86 linux with trinity (and without e= xcluding the munmap syscall but it might be independed from this) gives= within a 32 bit user mode linux guest : The problem with these sorts of trinity bug reports is that we have no idea which syscall or set of syscalls might have corrupted kernel state to the point where the kernel started malfunctioning. Sometimes, a trinity induced bug is obvious, when it causes a system call to immediately access an illegal memory location. But if it causes some more subtle corruption, possibly in a completely unrelated subsystem, figuring out what actually happened can be close to impossible. So there's not much I can do with this sort of bug report. If you can easily repeat it, and you can dump out the system call stream, we might be able to make a smaller reproduction case, at which point trying to debug this sort of failure would be tractable. Cheers, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XE0u9-00021x-Up for user-mode-linux-devel@lists.sourceforge.net; Sun, 03 Aug 2014 18:53:14 +0000 Received: from imap.thunk.org ([74.207.234.97]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1XE0u8-0007cb-HY for user-mode-linux-devel@lists.sourceforge.net; Sun, 03 Aug 2014 18:53:13 +0000 Date: Sun, 3 Aug 2014 14:42:10 -0400 From: Theodore Ts'o Message-ID: <20140803184210.GV24826@thunk.org> References: <53DE3E92.3060304@gmx.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <53DE3E92.3060304@gmx.de> List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net Subject: Re: [uml-devel] fuzz testing an ext4fs file system under a 32 bit Linux user mode linux guest let task jbd2/ubda hang To: Toralf =?iso-8859-1?Q?F=F6rster?= Cc: linux-ext4@vger.kernel.org, UML devel On Sun, Aug 03, 2014 at 03:52:18PM +0200, Toralf F=F6rster wrote: > Hello, > = > fuzzying a 32 bit stable Gentoo x86 linux with trinity (and without exclu= ding the munmap syscall but it might be independed from this) gives within = a 32 bit user mode linux guest : The problem with these sorts of trinity bug reports is that we have no idea which syscall or set of syscalls might have corrupted kernel state to the point where the kernel started malfunctioning. Sometimes, a trinity induced bug is obvious, when it causes a system call to immediately access an illegal memory location. But if it causes some more subtle corruption, possibly in a completely unrelated subsystem, figuring out what actually happened can be close to impossible. So there's not much I can do with this sort of bug report. If you can easily repeat it, and you can dump out the system call stream, we might be able to make a smaller reproduction case, at which point trying to debug this sort of failure would be tractable. Cheers, - Ted ---------------------------------------------------------------------------= --- Want fast and easy access to all the code in your enterprise? Index and search up to 200,000 lines of code with a free copy of Black Duck Code Sight - the same software that powers the world's largest code search on Ohloh, the Black Duck Open Hub! Try it now. http://p.sf.net/sfu/bds _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel