From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751401AbWFEUME (ORCPT ); Mon, 5 Jun 2006 16:12:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751404AbWFEUMD (ORCPT ); Mon, 5 Jun 2006 16:12:03 -0400 Received: from xenotime.net ([66.160.160.81]:42463 "HELO xenotime.net") by vger.kernel.org with SMTP id S1751401AbWFEUMB (ORCPT ); Mon, 5 Jun 2006 16:12:01 -0400 Date: Mon, 5 Jun 2006 13:14:47 -0700 From: "Randy.Dunlap" To: Dave Jones Cc: mingo@elte.hu, mbligh@google.com, akpm@osdl.org, apw@shadowen.org, linux-kernel@vger.kernel.org Subject: Re: 2.6.17-rc5-mm3 Message-Id: <20060605131447.4f46bbaf.rdunlap@xenotime.net> In-Reply-To: <20060605200554.GB6143@redhat.com> References: <44845C27.3000006@google.com> <20060605194422.GB14709@elte.hu> <20060605130039.db1ac80c.rdunlap@xenotime.net> <20060605200554.GB6143@redhat.com> Organization: YPO4 X-Mailer: Sylpheed version 2.2.5 (GTK+ 2.8.3; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 5 Jun 2006 16:05:54 -0400 Dave Jones wrote: > On Mon, Jun 05, 2006 at 01:00:39PM -0700, Randy.Dunlap wrote: > > On Mon, 5 Jun 2006 21:44:22 +0200 Ingo Molnar wrote: > > > > > > > > * Martin Bligh wrote: > > > > > > > panic on NUMA-Q during LTP. Was fine in -mm2. > > > > > > > > BUG: unable to handle kernel paging request at virtual address 22222232 > > > > > > > EIP is at check_deadlock+0x19/0xe1 > > > > eax: 00000001 ebx: e4453030 ecx: 00000000 edx: e4008000 > > > > esi: 22222222 edi: 00000001 ebp: 22222222 esp: e47ebec0 > > > > > > again these 0x22222222 entries on the stack. What on earth does this? > > > Andy got a similar crash on x86_64, with a 0x2222222222222222 entry ... > > > > > > nothing of our magic values are 0x22 or 0x222222222. > > > > kernel/mutex-debug.c: > > void debug_mutex_free_waiter(struct mutex_waiter *waiter) > > { > > DEBUG_WARN_ON(!list_empty(&waiter->list)); > > memset(waiter, 0x22, sizeof(*waiter)); > > } > > Documentation/magic-number.txt sounds so promising, but we scatter definitions > of numbers all over the place. (No mention of the slab poison values, > or similar numbers there for eg, and various pointers to _other_ lists > of magic numbers). I have a few more that I can add to include/linux/poison.h, like this one above (only in -mm at present). ./include/linux/libata.h:#define ATA_TAG_POISON 0xfafbfcfdU ./arch/ppc/8260_io/fcc_enet.c:1918: memset((char *)(&(immap->im_dprambase[(mem_addr+64)])), 0x88, 32); ./drivers/usb/mon/mon_text.c:429: memset(mem, 0xe5, sizeof(struct mon_event_text)); ./kernel/mutex-debug.c:384: memset(waiter, 0x11, sizeof(*waiter)); ./kernel/mutex-debug.c:400: memset(waiter, 0x22, sizeof(*waiter)); ./security/keys/key.c:985: memset(&key->payload, 0xbd, sizeof(key->payload)); ./drivers/char/ftape/lowlevel/ftape-ctl.c:738: memset(ft_buffer[i]->address, 0xAA, FT_BUFF_SIZE); ./drivers/block/sx8.c:/* 0xf is just arbitrary, non-zero noise; this is sorta like poisoning */ --- ~Randy