From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752869AbZHTIAX (ORCPT ); Thu, 20 Aug 2009 04:00:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752775AbZHTIAV (ORCPT ); Thu, 20 Aug 2009 04:00:21 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:52811 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752001AbZHTIAQ convert rfc822-to-8bit (ORCPT ); Thu, 20 Aug 2009 04:00:16 -0400 To: Dave Young Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Linus Torvalds , Alan Cox , Greg Kroah-Hartman References: From: ebiederm@xmission.com (Eric W. Biederman) Date: Thu, 20 Aug 2009 01:00:06 -0700 In-Reply-To: (Dave Young's message of "Thu\, 20 Aug 2009 15\:54\:53 +0800") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Rcpt-To: hidave.darkstar@gmail.com, gregkh@suse.de, alan@lxorguk.ukuu.org.uk, torvalds@linux-foundation.org, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Dave Young X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 XM_SPF_Neutral SPF-Neutral * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay Subject: Re: v2.6.31-rc6: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dave Young writes: > On Thu, Aug 20, 2009 at 2:07 PM, Eric W. Biederman wrote: >> >> ebiederm@xmission.com (Eric W. Biederman) writes: >> >>> I'm not certain who I should route this too, but I just had 2.6.31-rc6 >>> fall over on me.  I don't know how reproducible this will be but >>> I have a full crash dump if someone is interested in looking into this. >> >> Looks like I was wrong.  This is appears trivial to reproduce, >> I have just reproduced it two more times in a row.  I think >> the problem is pty related. >> >> I was looking into a change in behavior on 2.6.31-rc6 where >> data was being lost, and it appears one variant of my test program >> kills the kernel. >> >> The following program run as an unprivileged user causes a kernel >> panic in about a minute: >> >> aka >> >> while :; do ./KernelTtyTest ; done > > The test app failed for me: > > read failed: Input/output error > lastbytes: '\r\nprocess_cmd read failed: Interrupted system > call\r\necho _2_\r\n' > Aborted Oh. It definitely fails. I just found that when it failed about 600 times in a row it took my kernel with it. I was developing it to understand tty interactions, and when I realized that the version I had was killing my kernel I sent it out as it was a nice self contained test case. Eric