From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932212AbWGRN5l (ORCPT ); Tue, 18 Jul 2006 09:57:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932218AbWGRN5k (ORCPT ); Tue, 18 Jul 2006 09:57:40 -0400 Received: from orca.ele.uri.edu ([131.128.51.63]:25033 "EHLO orca.ele.uri.edu") by vger.kernel.org with ESMTP id S932212AbWGRN5k (ORCPT ); Tue, 18 Jul 2006 09:57:40 -0400 Date: Tue, 18 Jul 2006 09:58:17 -0400 From: Will Simoneau To: linux-kernel@vger.kernel.org Cc: grsecurity@grsecurity.net Subject: kdeinit causes scheduling while atomic Message-ID: <20060718135817.GA21666@ele.uri.edu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="qDbXVdCdHGoSgWSk" Content-Disposition: inline User-Agent: Mutt/1.5.11 [Linux 2.6.17.6-grsec-b0rg i686] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --qDbXVdCdHGoSgWSk Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable A scheduling while atomic just started showing up in the kernel log on my machine, which unfortunately is running an odd combination of non-vanilla patches. Maybe someone who knows at least some of the code can give me some hints tracking this down? Or maybe the grsecurity folks have an idea? Patches applied on top of 2.6.17.6: grsecurity-2.1.9-2.6.17.4-200607120947 suspend2-2.2.7-for-2.6.17 (without 9920-linus-basic-trace - that plus grsecurity gives rejects on vmlinux.lds.S) System is running Gentoo, the compiler is gcc 3.4.6 with pie & ssp although those features are turned off when compiling a kernel by the specs file. Userland is compiled with -fstack-protector, and I am using SEGMEXEC for userland NX support. I have two different traces and some PaX output, here they all are: ---cut here--- BUG: scheduling while atomic: kdeinit/0x00000002/31816 schedule+0x53e/0x674 schedule_timeout+0x4d/0x9a process_timeout+0x0/0x5 sched_fork+0x51/0x86 copy_process+0x614/0xdea do_fork+0x75/0x1b2 vfs_write+0xec/0x16e sys_clone+0x32/0x36 syscall_call+0x7/0xb init_script_binfmt+0x6/0xa ---end cut---- ---cut here--- BUG: scheduling while atomic: kdeinit/0x00000002/31816 schedule+0x53e/0x674 schedule_timeout+0x4d/0x9a process_timeout+0x0/0x5 sched_fork+0x51/0x86 copy_process+0x614/0xdea do_fork+0x75/0x1b2 sys_clone+0x32/0x36 syscall_call+0x7/0xb irq_entries_start+0xecb/0xef0=20 ---end cut---- ---cut here--- PAX: execution attempt in: , 00000000-00000000 00000000 PAX: terminating task: /usr/kde/3.5/bin/konqueror(konqueror):21177, uid/eui= d: 1000/1000, PC: 00000010, SP: 5953cf80 PAX: bytes at PC: ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? = ??=20 PAX: bytes at SP-4: 00000010 00000003 5953cfb0 00000000 0000000a 0000001c 4= 0488ef8 0000001d 5618e6e0 40083d30 00000000 00000003 55efdb83 40189c00 5610= 8d92 56b09377 5618e6e0 5953d000 00000006 404eadb8 55f2bef8=20 ---end cut---- Call of a null function pointer? Sometimes konqueror is killed by PaX, sometimes it dies on its own (I think with a segfault). I can reproduce this 100% of the time by firing up Konqueror and going to www.wikipedia.org, just before the front page loads the window dissapears and leave those traces behind. Other sites seem to work fine. The process either segfaults or is killed by PaX immediately after causing the scheduling while atomic. In the terminal where I start konqueror I see this (when PaX does the killing): ---cut here--- Try to load libthai dynamically... Error, can't load libthai... zsh: killed konqueror ---end cut---- =2E.. which seems to be an old unsolved bug in qt. Do I or anybody else have any hope of tracking this down? It almost sounds like an interaction of multiple bugs. --qDbXVdCdHGoSgWSk Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.4 (GNU/Linux) iD8DBQFEvOj5LYBaX8VDLLURAlvlAJ9sBXxJpgW/f4CThg1k40S0ZdZBFwCfYgpd wHIKhyEpDw101SkEF0kxl1o= =QrWC -----END PGP SIGNATURE----- --qDbXVdCdHGoSgWSk--