From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1FKPFG-0001AK-Fb for user-mode-linux-devel@lists.sourceforge.net; Fri, 17 Mar 2006 16:24:38 -0800 Received: from smtp009.mail.ukl.yahoo.com ([217.12.11.63]) by mail.sourceforge.net with smtp (Exim 4.44) id 1FKPFB-0003RD-Vc for user-mode-linux-devel@lists.sourceforge.net; Fri, 17 Mar 2006 16:24:38 -0800 From: Blaisorblade Subject: Re: [uml-devel] kernel BUG at drivers/block/loop.c:621 References: <200603171912.12082.rob@landley.net> In-Reply-To: <200603171912.12082.rob@landley.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200603180124.19077.blaisorblade@yahoo.it> Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sat, 18 Mar 2006 01:24:18 +0100 To: user-mode-linux-devel@lists.sourceforge.net Cc: Rob Landley , linux-kernel@vger.kernel.org On Saturday 18 March 2006 01:12, Rob Landley wrote: > I can reproduce the following in 2.6.16-rc5, User Mode Linux: > > kernel BUG at drivers/block/loop.c:621! > Kernel panic - not syncing: BUG! > > EIP: 0073:[] CPU: 0 Not tainted ESP: 007b:b7de1f9c EFLAGS: > 00200246 Not tainted > EAX: 00000000 EBX: 000018be ECX: 00000013 EDX: 000018be > ESI: 000018bb EDI: 00000011 EBP: b7de1fb8 DS: 007b ES: 007b > 09b87bb4: [<0806c762>] show_regs+0x102/0x110 > 09b87bd0: [<0805b6fc>] panic_exit+0x2c/0x50 > 09b87be0: [<0807ff7d>] notifier_call_chain+0x2d/0x50 > 09b87c00: [<08071095>] panic+0x75/0x120 > 09b87c20: [<0812e181>] loop_thread+0x151/0x160 > 09b87c4c: [<08065297>] run_kernel_thread+0x37/0x60 > 09b87cfc: [<0805bbd1>] new_thread_handler+0x91/0xc0 The below is strange - GCC is putting disks in the .text section or kallsyms has some bug. > 09b87d20: [] disks+0xf7e7ec84/0x4 > The reproduction sequence is a bit involved (my mount regression test and > the current svn snapshot of busybox are involved), and running the > following sequence of commands: > > mount; mount -a; mount; mount /dev/loop1 /images/vfat.dir ; > losetup /dev/loop1; ls; vi /etc/fstab; cat /etc/fstab; losetup /dev/loop0; > mount /images/vfat.img /images/vfat.dir -o ro > > The current busybox mount is still broken in a couple of known places > (hence the testing; I'm fixing it). But it probably shouldn't panic the > kernel... *) Is this reproducible on host? *) I don't understand yet what UML may be doing wrong. *) look at: that spin_lock (SMP kernel? SPINLOCK_DEBUG? Try enabling the latter and see what happens). (a bio is a block I/O request) *) given what the code says, on that line bio is NULL, i.e. loop_get_bio returned NULL, i.e. (I guess) wait_for_completion_interruptible returned, because someone else (loop_make_request) did "complete" on its param, but incorrectly as the "someone else" hadn't filled the lo->lo_bio. -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Messenger with Voice: chiama da PC a telefono a tariffe esclusive http://it.messenger.yahoo.com ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel