From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751079Ab3KMVMC (ORCPT ); Wed, 13 Nov 2013 16:12:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:1747 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750895Ab3KMVLz (ORCPT ); Wed, 13 Nov 2013 16:11:55 -0500 Date: Wed, 13 Nov 2013 16:11:47 -0500 From: Dave Jones To: Al Viro Cc: Linux Kernel Subject: recursive locking (coredump/vfs_write) Message-ID: <20131113211147.GA30263@redhat.com> Mail-Followup-To: Dave Jones , Al Viro , Linux Kernel MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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 Hey Al, here's another one.. ============================================= [ INFO: possible recursive locking detected ] 3.12.0+ #2 Not tainted --------------------------------------------- trinity-child3/13302 is trying to acquire lock: (sb_writers#5){.+.+.+}, at: [] vfs_write+0x173/0x1f0 but task is already holding lock: (sb_writers#5){.+.+.+}, at: [] do_coredump+0xf1d/0x1070 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sb_writers#5); lock(sb_writers#5); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by trinity-child3/13302: #0: (sb_writers#5){.+.+.+}, at: [] do_coredump+0xf1d/0x1070 stack backtrace: CPU: 3 PID: 13302 Comm: trinity-child3 Not tainted 3.12.0+ #2 ffffffff82526e10 ffff8801b54af820 ffffffff8171b3dc ffffffff82526e10 ffff8801b54af8e0 ffffffff810d722b 00007f93d6ce5000 0000000000000000 ffff880154b3f200 ffff880100000000 00000000004da26d ffffffff821b3901 Call Trace: [] dump_stack+0x4e/0x7a [] __lock_acquire+0x19ab/0x19f0 [] ? __do_page_fault+0x264/0x610 [] ? native_sched_clock+0x24/0x80 [] ? trace_hardirqs_off_caller+0x1f/0xc0 [] lock_acquire+0x93/0x1c0 [] ? vfs_write+0x173/0x1f0 [] __sb_start_write+0xc9/0x1a0 [] ? vfs_write+0x173/0x1f0 [] ? vfs_write+0x173/0x1f0 [] ? security_file_permission+0x23/0xa0 [] vfs_write+0x173/0x1f0 [] dump_emit+0x92/0xd0 [] elf_core_dump+0xde0/0x1740 [] ? elf_core_dump+0x8c2/0x1740 [] do_coredump+0xc9e/0x1070 [] ? __slab_free+0x191/0x35d [] get_signal_to_deliver+0x2c8/0x930 [] do_signal+0x48/0x610 [] ? get_lock_stats+0x19/0x60 [] ? put_lock_stats.isra.28+0xe/0x30 [] ? pagefault_enable+0xe/0x21 [] ? context_tracking_user_exit+0x4e/0x190 [] ? trace_hardirqs_on_caller+0x115/0x1e0 [] do_notify_resume+0x5c/0xa0 [] retint_signal+0x46/0x90