From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752547Ab2LYWbB (ORCPT ); Tue, 25 Dec 2012 17:31:01 -0500 Received: from mail.skyhub.de ([78.46.96.112]:38741 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751145Ab2LYWa6 (ORCPT ); Tue, 25 Dec 2012 17:30:58 -0500 Date: Tue, 25 Dec 2012 23:30:45 +0100 From: Borislav Petkov To: kvm list , x86@kernel.org Cc: lkml Subject: kvm lockdep splat with 3.8-rc1+ Message-ID: <20121225223045.GA23445@liondog.tnic> Mail-Followup-To: Borislav Petkov , kvm list , x86@kernel.org, lkml MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, just saw this in dmesg while running -rc1 + tip/master: [ 6983.694615] ============================================= [ 6983.694617] [ INFO: possible recursive locking detected ] [ 6983.694620] 3.8.0-rc1+ #26 Not tainted [ 6983.694621] --------------------------------------------- [ 6983.694623] kvm/20461 is trying to acquire lock: [ 6983.694625] (&anon_vma->rwsem){++++..}, at: [] mm_take_all_locks+0x148/0x1a0 [ 6983.694636] [ 6983.694636] but task is already holding lock: [ 6983.694638] (&anon_vma->rwsem){++++..}, at: [] mm_take_all_locks+0x148/0x1a0 [ 6983.694645] [ 6983.694645] other info that might help us debug this: [ 6983.694647] Possible unsafe locking scenario: [ 6983.694647] [ 6983.694649] CPU0 [ 6983.694650] ---- [ 6983.694651] lock(&anon_vma->rwsem); [ 6983.694654] lock(&anon_vma->rwsem); [ 6983.694657] [ 6983.694657] *** DEADLOCK *** [ 6983.694657] [ 6983.694659] May be due to missing lock nesting notation [ 6983.694659] [ 6983.694661] 4 locks held by kvm/20461: [ 6983.694663] #0: (&mm->mmap_sem){++++++}, at: [] do_mmu_notifier_register+0x153/0x180 [ 6983.694670] #1: (mm_all_locks_mutex){+.+...}, at: [] mm_take_all_locks+0x3c/0x1a0 [ 6983.694678] #2: (&mapping->i_mmap_mutex){+.+...}, at: [] mm_take_all_locks+0xcd/0x1a0 [ 6983.694686] #3: (&anon_vma->rwsem){++++..}, at: [] mm_take_all_locks+0x148/0x1a0 [ 6983.694694] [ 6983.694694] stack backtrace: [ 6983.694696] Pid: 20461, comm: kvm Not tainted 3.8.0-rc1+ #26 [ 6983.694698] Call Trace: [ 6983.694704] [] __lock_acquire+0x89a/0x1f30 [ 6983.694708] [] ? trace_hardirqs_off+0xd/0x10 [ 6983.694711] [] ? mark_held_locks+0x8d/0x110 [ 6983.694714] [] ? mm_take_all_locks+0xcd/0x1a0 [ 6983.694718] [] lock_acquire+0x9e/0x1f0 [ 6983.694720] [] ? mm_take_all_locks+0x148/0x1a0 [ 6983.694724] [] ? put_lock_stats.isra.17+0xe/0x40 [ 6983.694728] [] down_write+0x49/0x90 [ 6983.694731] [] ? mm_take_all_locks+0x148/0x1a0 [ 6983.694734] [] mm_take_all_locks+0x148/0x1a0 [ 6983.694737] [] ? do_mmu_notifier_register+0x153/0x180 [ 6983.694740] [] do_mmu_notifier_register+0x7f/0x180 [ 6983.694742] [] mmu_notifier_register+0x13/0x20 [ 6983.694765] [] kvm_dev_ioctl+0x3cd/0x4f0 [kvm] [ 6983.694768] [] do_vfs_ioctl+0x90/0x570 [ 6983.694772] [] ? fget_light+0x323/0x4c0 [ 6983.694775] [] sys_ioctl+0x50/0x90 [ 6983.694781] [] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 6983.694785] [] system_call_fastpath+0x16/0x1b -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --