From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751055AbcBKP40 (ORCPT ); Thu, 11 Feb 2016 10:56:26 -0500 Received: from tiger.mobileactivedefense.com ([217.174.251.109]:46879 "EHLO tiger.mobileactivedefense.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750725AbcBKP4Y (ORCPT ); Thu, 11 Feb 2016 10:56:24 -0500 From: Rainer Weikusat To: Philipp Hahn Cc: Hannes Frederic Sowa , Sasha Levin , Rainer Weikusat , "David S. Miller" , linux-kernel@vger.kernel.org, Karolin Seeger , Jason Baron , Ben Hutchings , Greg Kroah-Hartman , Arvid Requate , Stefan Gohmann Subject: Re: Bug 4.1.16: self-detected stall in net/unix/? In-Reply-To: <56BC90E7.7040007@pmhahn.de> (Philipp Hahn's message of "Thu, 11 Feb 2016 14:47:19 +0100") References: <56B4BF9D.9070609@pmhahn.de> <56BC90E7.7040007@pmhahn.de> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux) Date: Thu, 11 Feb 2016 15:55:42 +0000 Message-ID: <87fuwzkzr5.fsf@doppelsaurus.mobileactivedefense.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.4.3 (tiger.mobileactivedefense.com [217.174.251.109]); Thu, 11 Feb 2016 15:55:50 +0000 (GMT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Philipp Hahn writes: [...] > Probably the same bug was also reported to samba-technical by Karolin > Seeger; she filed the bug for 3.19-ckt with Ubuntu: > > > > Running the Samba test suite reproduces the problem; see bug for > details. JFTR: The oops in this bug report is for 3.13.0-77 and the patch you reverted for 4.1 is not part of that (at least not of the upstream 3.13). [...] >> [ 598.492559] ===================================== >> [ 598.502646] [ BUG: bad unlock balance detected! ] >> [ 598.512874] 4.1.16+ #24 Not tainted >> [ 598.523134] ------------------------------------- >> [ 598.533592] smbd/8659 is trying to release lock (&(&u->lock)->rlock) at: >> [ 598.544429] [] spin_unlock+0x9/0x10 >> [ 598.555148] but there are no more locks to release! >> [ 598.565892] >> [ 598.565892] other info that might help us debug this: >> [ 598.586936] no locks held by smbd/8659. >> [ 598.597478] >> [ 598.597478] stack backtrace: >> [ 598.618275] CPU: 3 PID: 8659 Comm: smbd Not tainted 4.1.16+ #24 >> [ 598.628820] Hardware name: System manufacturer System Product Name/P7F-X Series, BIOS 0703 09/24/2010 >> [ 598.650020] ffffffff815d1319 ffff8800b8efbb88 ffffffff8163ee73 0000000000000000 >> [ 598.661051] ffff880034fc4110 ffff8800b8efbbb8 ffffffff810db540 ffff880034fc4110 >> [ 598.671990] ffff880034fc4110 ffff88023206bd40 ffffffff815d1319 ffff8800b8efbc08 >> [ 598.682736] Call Trace: >> [ 598.693187] [] ? spin_unlock+0x9/0x10 >> [ 598.703798] [] dump_stack+0x4c/0x65 >> [ 598.714223] [] print_unlock_imbalance_bug+0x100/0x110 >> [ 598.724611] [] ? spin_unlock+0x9/0x10 >> [ 598.734763] [] lock_release+0x2be/0x430 >> [ 598.744636] [] _raw_spin_unlock+0x23/0x40 >> [ 598.754230] [] ? unix_dgram_sendmsg+0x288/0x6f0 >> [ 598.763840] [] spin_unlock+0x9/0x10 >> [ 598.773126] [] unix_dgram_sendmsg+0x2c7/0x6f0 >> [ 598.782209] [] sock_sendmsg+0x4d/0x60 >> [ 598.791313] [] ___sys_sendmsg+0x2db/0x2f0 >> [ 598.800369] [] ? kmem_cache_free+0x328/0x360 >> [ 598.809383] [] ? locks_free_lock+0x50/0x60 >> [ 598.818157] [] __sys_sendmsg+0x49/0x90 >> [ 598.826742] [] SyS_sendmsg+0x12/0x20 >> [ 598.835110] [] system_call_fastpath+0x16/0x7a >> [ 598.843546] ------------[ cut here ]------------ >> [ 598.851999] WARNING: CPU: 3 PID: 8659 at net/core/skbuff.c:691 skb_release_head_state+0xaa/0xb0() Could you send your disassembled unix_dgram_sendmsg (objdump -d)? This would be enormously helpful wrt determining which unlock is involved here.