From owner-freebsd-stable@freebsd.org Tue Apr 17 15:24:34 2018 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 03F1DF83660 for ; Tue, 17 Apr 2018 15:24:34 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A8C488591F for ; Tue, 17 Apr 2018 15:24:33 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: from mail-lf0-f51.google.com (mail-lf0-f51.google.com [209.85.215.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) (Authenticated sender: kevans) by smtp.freebsd.org (Postfix) with ESMTPSA id 5FE8AEF0C for ; Tue, 17 Apr 2018 15:24:33 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: by mail-lf0-f51.google.com with SMTP id m202-v6so10669330lfe.8 for ; Tue, 17 Apr 2018 08:24:33 -0700 (PDT) X-Gm-Message-State: ALQs6tAIM/5DWctFD6AJobkF1VpThEyZZVTtF7JxQXPJbkR983nKMzBp HlG1V6swKDf+gi0OSJ2jFNhxxtoxuebqFBkaeYQ= X-Google-Smtp-Source: AIpwx4/vPNT7guMEFJBCl4ZOBz5PLc5wW+T3Arw/VDGBqb6J9dkemYVaW3m6i2cfrOjAY3TXa0s6P3f5MPGsb5K0MvQ= X-Received: by 10.46.153.147 with SMTP id w19mr1858635lji.93.1523978671899; Tue, 17 Apr 2018 08:24:31 -0700 (PDT) MIME-Version: 1.0 Received: by 10.46.129.90 with HTTP; Tue, 17 Apr 2018 08:24:11 -0700 (PDT) In-Reply-To: <4EE33A98-C010-4D79-A502-19D009384B0D@gmail.com> References: <4EE33A98-C010-4D79-A502-19D009384B0D@gmail.com> From: Kyle Evans Date: Tue, 17 Apr 2018 10:24:11 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: amd64 kernel crash introduced between 20180329 & 20180408 To: Dan Allen Cc: FreeBSD-STABLE Mailing List Content-Type: text/plain; charset="UTF-8" X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Apr 2018 15:24:34 -0000 On Tue, Apr 17, 2018 at 10:18 AM, Dan Allen wrote: > > >> On 17 Apr 2018, at 8:49 AM, Kyle Evans wrote: >> >> As "the guy most likely to have broken boot code in stable," may I ask >> what leads you specifically to amd64 boot code? Mostly curious if >> there's something beyond "i386 works well" that lead you to this >> conclusion. > > It is partly just a hunch. > > I installed 11.0 for use with qemu a while ago. I did binary upgrades for patches using > freebsd-update. When 11.1 came out, it would not work correctly, again with the same > kind of behavior. Then, I got some later snapshots that worked again, notably the 20180329 > build. When the next snapshot came out, things broke. I also tried my own builds, same story. > > I even got both source trees together - 20180329 and 20180408 - and did a diff on the entire > trees, and I noticed activity in the boot & kernel code. It could just as likely be something in the > kernel as well, but none of this happens with the i386 build. > >> When you say it crashes and does a kernel dump- you're landing at a >> ddb prompt, yeah? What does executing bt at that prompt look like? > > No, I am not ever given a prompt. I get to watch a mini-dump happen and then an automatic > reboot. It is a kernel panic. Here is what I see: > Ahh, fun. =) I'm inclined to think it's probably not a boot code problem, but it is suspicious. Can you set vm.pmap.pti=0 at the loader prompt and see if this affects your situation at all, just to rule that out?