From owner-freebsd-stable@FreeBSD.ORG Sun Oct 21 18:28:11 2012 Return-Path: Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id E90BECBA for ; Sun, 21 Oct 2012 18:28:11 +0000 (UTC) (envelope-from mavbsd@gmail.com) Received: from mail-lb0-f182.google.com (mail-lb0-f182.google.com [209.85.217.182]) by mx1.freebsd.org (Postfix) with ESMTP id 60E238FC18 for ; Sun, 21 Oct 2012 18:28:11 +0000 (UTC) Received: by mail-lb0-f182.google.com with SMTP id b5so1585817lbd.13 for ; Sun, 21 Oct 2012 11:28:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=X0IeLJGbdcLrmnvWIpmKAcdvZGApZL13ucKwTVgFb28=; b=AimzoKvg4EyLFexvUpH7f+EoJgIMyLtC0LZqBeUdjY/sNWYbBC/AwZbx9ZjG0BgqFY TAEFlww0/Jq+uv0zoRKwzMBlxd1HpUzERs7gj+Y9YHP2xivkIxF3NNeH4sZo+TCAdGC5 k01+YD7M1LKkJI3yw7wtbstS7Tl3qfN9KrSi6hH+QoCOt6iz11q8uwiNdpwIApREUUN+ t5rxdvR99Ty6Q1zXTrjOvskGR1g0sm65BQghVxPzdKMtcP9wBtjD9A+Lj7wJQoWksw4U I2X5llqU4DnmHVKlWi7KiNFKfieRfE5CY2LcliqaYFkiHIyiOeczlOf/CS4Id+XNAghn 2beQ== Received: by 10.152.47.79 with SMTP id b15mr6166749lan.57.1350844089927; Sun, 21 Oct 2012 11:28:09 -0700 (PDT) Received: from mavbook.mavhome.dp.ua (mavhome.mavhome.dp.ua. [213.227.240.37]) by mx.google.com with ESMTPS id gt17sm2314430lab.6.2012.10.21.11.28.08 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 21 Oct 2012 11:28:08 -0700 (PDT) Sender: Alexander Motin Message-ID: <50843EB6.8030407@FreeBSD.org> Date: Sun, 21 Oct 2012 21:28:06 +0300 From: Alexander Motin User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:13.0) Gecko/20120628 Thunderbird/13.0.1 MIME-Version: 1.0 To: David Wolfskill Subject: Re: stable/9 @r241776 panic: REDZONE: Buffer underflow detected... References: <20121020141019.GW1817@albert.catwhisker.org> <20121021121356.GJ35915@deviant.kiev.zoral.com.ua> <20121021163322.GB1730@albert.catwhisker.org> <20121021164634.GC1730@albert.catwhisker.org> <20121021174054.GM35915@deviant.kiev.zoral.com.ua> In-Reply-To: <20121021174054.GM35915@deviant.kiev.zoral.com.ua> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Konstantin Belousov , stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 21 Oct 2012 18:28:12 -0000 On 21.10.2012 20:40, Konstantin Belousov wrote: > On Sun, Oct 21, 2012 at 09:46:34AM -0700, David Wolfskill wrote: >> On Sun, Oct 21, 2012 at 09:33:22AM -0700, David Wolfskill wrote: >>> ... >>> So I tried reverting 241749 ... and I failed to reproduce the problem. >>> >>> Well, one boot out of one, at least. I'll try a few more reality >>> checks, and report back if a correction is in order. But (for now, at >>> least), it looks to me as if 241749 is presenting a problem on this >>> laptop. >>> ... >> >> 5 for 5. I'm convinced that 241749 causes problems on this laptop for >> attempts to boot without a stop is single-user mode first. >> >> (So that sounds like a timing issue, somehow.) >> >> And thanks again, Konstantin! > > I do not know/do not understand the CAM code, the question shall > be addressed to Alexander. It still might be a false positive. I don't see how increasing buffer size by few bytes in mentioned change may cause memory corruption in some other place. I guess change can be just innocent witness that affected some memory placement, moving some existing corruption from one area to another where it was noticed. I am curious, how to interpret phrase "42=94966796 bytes allocated" in log. May be it is just corrupted output, but the number still seems quite big, especially for i386 system, making me think about some integer overflow. David, could you write down that part once more? Having few more lines of "Allocation backtrace:" could also be useful. Could you show your kernel config? I can try to run it on my tests system, hoping to reproduce the problem. -- Alexander Motin