Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932459AbaJVTUz (ORCPT ); Wed, 22 Oct 2014 15:20:55 -0400 Received: from mail-la0-f49.google.com ([209.85.215.49]:39977 "EHLO mail-la0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751342AbaJVTUy (ORCPT ); Wed, 22 Oct 2014 15:20:54 -0400 MIME-Version: 1.0 In-Reply-To: <20141022191643.GU15532@madcap2.tricolour.ca> References: <1414002190.30946.95.camel@localhost> <5447FF10.3060506@amacapital.net> <20141022191643.GU15532@madcap2.tricolour.ca> From: Andy Lutomirski Date: Wed, 22 Oct 2014 12:20:31 -0700 Message-ID: Subject: Re: Regression: audit: x86: drop arch from __audit_syscall_entry() interface To: Richard Guy Briggs Cc: Eric Paris , Paulo Zanoni , linux-audit@redhat.com, Intel Graphics Development , X86 ML , "linux-kernel@vger.kernel.org" , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 22, 2014 at 12:16 PM, Richard Guy Briggs wrote: > On 14/10/22, Andy Lutomirski wrote: >> On 10/22/2014 11:23 AM, Eric Paris wrote: >> > That's really serious. Looking now. >> > >> > On Wed, 2014-10-22 at 16:08 -0200, Paulo Zanoni wrote: >> >> Hi >> >> >> >> (Cc'ing everybody mentioned in the original patch) >> >> >> >> I work for Intel, on our Linux Graphics driver - aka i915.ko - and our >> >> QA team recently reported a regression on: >> >> >> >> commit b4f0d3755c5e9cc86292d5fd78261903b4f23d4a >> >> Author: Richard Guy Briggs >> >> Date: Tue Mar 4 10:38:06 2014 -0500 >> >> audit: x86: drop arch from __audit_syscall_entry() interface >> >> >> >> According to our QA, their i386 machine doesn't boot anymore. I tried >> >> to write my own revert for the patch, asked QA to test, and they >> >> confirmed it "solves" the problem. >> >> >> >> Here are the details of QA' s bug report: >> >> https://bugs.freedesktop.org/show_bug.cgi?id=85277 . >> >> >> >> The trees our QA tests are the development trees from i915.ko: >> >> http://cgit.freedesktop.org/drm-intel?h=drm-intel-fixes . >> >> >> >> I tried searching for other bug reports on the same patch, but >> >> couldn't find any. Forgive me if this bug was already reported. >> >> >> >> Feel free to continue this discussion on the bugzilla report if you want. >> >> This piece: >> >> movl %esi,4(%esp) /* 5th arg: 4th syscall arg */ >> movl %edx,(%esp) /* 4th arg: 3rd syscall arg */ >> >> looks like it's overwriting syscall arguments. >> >> This is clearly fixable, but an even better fix would be to drop the asm >> entirely and switch to two-phase tracing. Want to do it? I can test >> the seccomp bits if you switch over the asm :) > > Like what you did for x86_64. That sounds worth investigating. > > I'll have a look at the asm, but I'm being distracted by a gunman loose > 2km from me and my wife and kids under lockdown in two different > locations on the other side of the shooting site. Had to cancel lunch > today with two work colleagues 1/2km away from that site. ...not been a > productive day. > That's putting it mildly. Stay safe. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/