From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751331Ab1GYMGH (ORCPT ); Mon, 25 Jul 2011 08:06:07 -0400 Received: from mail-fx0-f52.google.com ([209.85.161.52]:64808 "EHLO mail-fx0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750864Ab1GYMGC (ORCPT ); Mon, 25 Jul 2011 08:06:02 -0400 Date: Mon, 25 Jul 2011 15:05:14 +0300 From: Sergey Senozhatsky To: Thomas Gleixner Cc: Andrew Morton , x86@kernel.org, Ingo Molnar , "H. Peter Anvin" , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: DEBUG_LOCKS_WARN_ON() within lockdep trace_hardirqs_on_caller() Message-ID: <20110725120514.GA3174@swordfish> 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 Hello, Current 3.1.0-git3 (03873-g2c9c838), x86_64, has triggered an DEBUG_LOCKS_WARN_ON() within trace_hardirqs_on_caller() [ 4364.656167] ------------[ cut here ]------------ [ 4364.656186] WARNING: at kernel/lockdep.c:2532 trace_hardirqs_on_caller+0x6d/0x166() [ 4364.656191] Hardware name: Aspire 5741G [ 4364.656264] Pid: 26796, comm: conftest Not tainted 3.1.0-dbg-03873-g2c9c838-dirty #652 [ 4364.656269] Call Trace: [ 4364.656279] [] warn_slowpath_common+0x7e/0x96 [ 4364.656289] [] ? __bad_area_nosemaphore+0x35/0x1b9 [ 4364.656296] [] warn_slowpath_null+0x15/0x17 [ 4364.656303] [] trace_hardirqs_on_caller+0x6d/0x166 [ 4364.656310] [] trace_hardirqs_on+0xd/0xf [ 4364.656317] [] __bad_area_nosemaphore+0x35/0x1b9 [ 4364.656324] [] bad_area+0x45/0x4c [ 4364.656333] [] do_page_fault+0x2da/0x48a [ 4364.656343] [] ? do_brk+0x24e/0x2a2 [ 4364.656352] [] ? trace_hardirqs_off_thunk+0x3a/0x3c [ 4364.656360] [] page_fault+0x25/0x30 [ 4364.656366] ---[ end trace 9870b4ffc9ea6750 ]--- I guess, local_irq_enable() gets called 2 times in do_page_fault(). First, 1051 if (user_mode_vm(regs)) { 1052 local_irq_enable(); 1053 error_code |= PF_USER; 1054 } else { 1055 if (regs->flags & X86_EFLAGS_IF) 1056 local_irq_enable(); 1057 } and later within one of bad_area-cases, e.g., 1106 vma = find_vma(mm, address); 1107 if (unlikely(!vma)) { 1108 bad_area(regs, error_code, address); 1109 return; 1110 } hitting assertion `!irqs_disabled()' failure in lockdep trace_hardirqs_on_caller(). Sergey