From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753005Ab2HCKDK (ORCPT <rfc822;w@1wt.eu>);
	Fri, 3 Aug 2012 06:03:10 -0400
Received: from zeniv.linux.org.uk ([195.92.253.2]:42942 "EHLO
	ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752337Ab2HCKDH (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 3 Aug 2012 06:03:07 -0400
Date: Fri, 3 Aug 2012 11:03:06 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: [signal:execve2] BUG: sleeping function called from sys_brk
Message-ID: <20120803100305.GC23464@ZenIV.linux.org.uk>
References: <20120803051412.GA10870@localhost>
 <20120803093028.GA16195@localhost>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20120803093028.GA16195@localhost>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, Aug 03, 2012 at 05:30:28PM +0800, Fengguang Wu wrote:
> Hi Al,
> 
> > I got a boot warning on commit
> > 
> > tree:   git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal.git execve2
> > head:   1ade99215ed3c334a544b9e1773602ff0f0251ab
> > commit: 1ade99215ed3c334a544b9e1773602ff0f0251ab [9/9] x86: switch to generic sys_execve and kernel_execve
> 
> The same commit triggers other warnings (new config and dmesg attached):
> 
> [   18.315125] debug: unmapping init [mem 0x816b6000-0x81852fff]
> [   18.318178] BUG: sleeping function called from invalid context at /c/kernel-tests/src/stable/kernel/rwsem.c:47
> [   18.318243] in_atomic(): 0, irqs_disabled(): 1, pid: 1, name: init
> [   18.318243] no locks held by init/1.
> [   18.318243] Pid: 1, comm: init Not tainted 3.5.0-01258-g1ade992 #182
> [   18.318243] Call Trace:
> [   18.318243]  [<8109e07d>] __might_sleep+0x13d/0x170
> [   18.318243]  [<813cea7c>] down_write+0x2c/0xd0
> [   18.318243]  [<81166ae9>] sys_brk+0x29/0x1f0
> [   18.318243]  [<813d22d0>] syscall_call+0x7/0xb

Ow...  I think I understand what happened here, and I really don't like the
picture ;-/  Could you check if slapping regs->flags = X86_EFLAGS_IF;
in process_32.c:start__thread() gets rid of that?