From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758668Ab0JXAxo (ORCPT ); Sat, 23 Oct 2010 20:53:44 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:35189 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758612Ab0JXAxn (ORCPT ); Sat, 23 Oct 2010 20:53:43 -0400 X-Authority-Analysis: v=1.1 cv=+c36koQ5Dcj/1qolKHjtkYAGXvrVJRRiKMp+84F5sLg= c=1 sm=0 a=LuwKl7ggZIAA:10 a=Q9fys5e9bTEA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=20KFwNOVAAAA:8 a=NReUeh_FT3k6cPml724A:9 a=Mrjqd2x8bkBZVG6EFgGypK_5ResA:4 a=PUjeQqilurYA:10 a=jEp0ucaQiEUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Subject: Re: [PATCH][GIT PULL] tracing: Fix compile issue for trace_sched_wakeup.c From: Steven Rostedt To: Ingo Molnar Cc: Jason Baron , LKML , Andrew Morton , Frederic Weisbecker , Thomas Gleixner , "H. Peter Anvin" , Peter Zijlstra , Arnaldo Carvalho de Melo , masami.hiramatsu.pt@hitachi.com In-Reply-To: <20101023200216.GA19324@elte.hu> References: <1287508282.16971.386.camel@gandalf.stny.rr.com> <20101019184111.GA17266@elte.hu> <20101020154045.GA18353@elte.hu> <20101020164324.GC7348@redhat.com> <20101020183329.GA12666@elte.hu> <20101021110925.GA27219@elte.hu> <20101022175845.GF6498@redhat.com> <20101022182433.GA24637@elte.hu> <20101022183900.GG6498@redhat.com> <20101023200216.GA19324@elte.hu> Content-Type: text/plain; charset="ISO-8859-15" Date: Sat, 23 Oct 2010 20:53:38 -0400 Message-ID: <1287881618.16971.657.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2010-10-23 at 22:02 +0200, Ingo Molnar wrote: > * Jason Baron wrote: > > > > Not the same config, and it's very spurious - i.e. a slightly different -tip > > > version with the same config will boot fine. (this suggests some race) > > > > if possible, can you post that .config? > > I just reproduced it again with tip-1128a72 - config and full bootlog attached. > > The crash picture tends to vary - sometimes it crashes in fork, sometimes in the > timer interrupt. Here's the current one: > > [ 15.384483] Running tests on trace events: > [ 15.388580] Testing event kfree_skb: > [ 15.392381] BUG: unable to handle kernel NULL pointer dereference at (null) > [ 15.395408] IP: [<(null)>] (null) Interesting, the jump was to NULL. I'm thinking it hit a trace point and jumped to a NULL address. I guess there's some strange race here. Is a cache flush missing somewhere. I'll look more into this on Monday. -- Steve > [ 15.395408] *pde = 00000000 > [ 15.395408] Oops: 0000 [#1] SMP > [ 15.395408] last sysfs file: > [ 15.395408] > [ 15.395408] Pid: 2, comm: kthreadd Not tainted 2.6.36-tip-03573-g1128a72-dirty #51926 A8N-E/System Product Name > [ 15.395408] EIP: 0060:[<00000000>] EFLAGS: 00010086 CPU: 0 > [ 15.395408] EIP is at 0x0 > [ 15.395408] EAX: c1049bb5 EBX: 00000286 ECX: 00000000 EDX: 00000000 > [ 15.395408] ESI: 00000000 EDI: f5cd96e0 EBP: 00000063 ESP: f6449f24 > [ 15.395408] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 > [ 15.395408] Process kthreadd (pid: 2, ti=f6448000 task=f64443d0 task.ti=f6448000) > [ 15.395408] Stack: > [ 15.395408] c104d4e6 00800711 00000000 00000000 00000000 00000001 f6a09b00 f64443d0 > [ 15.395408] c188a238 c1dffb00 c1f1f200 00000000 c1049c53 b3420a74 00800711 c1061a4b > [ 15.395408] f6449fc0 f6449f7c c102ea40 00000000 00000000 00000000 00000000 00000000 > [ 15.395408] Call Trace: > [ 15.395408] [] ? do_fork+0x205/0x2aa > [ 15.395408] [] ? dequeue_task+0x97/0xa6 > [ 15.395408] [] ? kthread+0x0/0x68 > [ 15.395408] [] ? kernel_thread+0x77/0x7f > [ 15.395408] [] ? kthread+0x0/0x68 > [ 15.395408] [] ? kernel_thread_helper+0x0/0x10 > [ 15.395408] [] ? kthreadd+0x8d/0xbf > [ 15.395408] [] ? kthreadd+0x0/0xbf > [ 15.395408] [] ? kernel_thread_helper+0x6/0x10 > [ 15.395408] Code: Bad EIP value. > [ 15.395408] EIP: [<00000000>] 0x0 SS:ESP 0068:f6449f24 > [ 15.395408] CR2: 0000000000000000 > [ 15.395408] ---[ end trace 105d75af79111d22 ]--- > > (One possibility would be kernel text corruption perhaps.) > > Thanks, > > Ingo