From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D596C4338F for ; Mon, 9 Aug 2021 13:31:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A59260F93 for ; Mon, 9 Aug 2021 13:31:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233076AbhHINcG (ORCPT ); Mon, 9 Aug 2021 09:32:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232697AbhHINcF (ORCPT ); Mon, 9 Aug 2021 09:32:05 -0400 Received: from mail-oi1-x230.google.com (mail-oi1-x230.google.com [IPv6:2607:f8b0:4864:20::230]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DEB4DC061796; Mon, 9 Aug 2021 06:31:44 -0700 (PDT) Received: by mail-oi1-x230.google.com with SMTP id u25so23501896oiv.5; Mon, 09 Aug 2021 06:31:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=tKtCgs9wzH8vQFhcPb9WxXt8+IKB3JL2wXyhSG5vzRo=; b=J2fg2+t4sPFLj1cMvbz6CNMuBaQg7N1Jyf/Ok5LVt3+HSjDIMV6PXNSUjMMZxdLwvi Yu6iyEQ/0KId/td3Pz9onaAmyB9KEgp9OyszAm/oHmE5nf2s1hs9xt84BoCR6Flu5cjn /IXSJw8k3WRwLRPUnWHVFRNOfSwQMDC/qCfnWWYEA77IZy1IXj3AjyGBUGt3fgRDQku+ cFvasW5CPDEwRwDog0uvSS49Jhcg2BiyKbNriQa3MNj1qc3D6qeNaq5UNtKMrx37lo0N CQ20rsccyliCbWqNgkc6KR7e83wuWFWqBXwa+IMAJZ6NemfBbH0Au371i7fiH+DumKmx ezAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=tKtCgs9wzH8vQFhcPb9WxXt8+IKB3JL2wXyhSG5vzRo=; b=hAde8M7mhwS9ulhtGaL7fU/p6qhEjW5epIqmTUvMzAUO/mfXiJw6IILPpWG/T1bp4k 0LjYiQahCBBH/J483alh1AE4959KWH0HerTbDaH3kH7UxIgMchcSBzVsyjYJEQYIw/qH LuUfm+wEd2Z5BdHbKplwiUqfjkrZ8ECN7Epmcy6RnlXpXKEXYhLfmBWYD6y7bY4mW64V /VVjXhZX5+2UnNIsMqKjd24mGslu+TWzwuoGxj9hDtjZjYOHboCJzFu9JRgzGE1SuA3R QuKYSlFvh4fQbPRwJKRRbB492XmgeQVjvwCBy7NBTAlH5rtvCPStIxCUUJI2YFBkeOWD H/bQ== X-Gm-Message-State: AOAM530S9Y+AUhwXStohwrgXulb6qmiCb0BDr4zsFw8MEfGLduGaJTGA nnKSeYPSn58YRJI8Be4q8GqTOldgRZNb8qWF5nI= X-Google-Smtp-Source: ABdhPJy5hTN76hsnz/r6sxWkfpHbCOzkYtie3g0jZCaQRvlHVsnF8fsi5CGvstxwAkZaoX3Naq5v9/U7gy3XRto0yBs= X-Received: by 2002:a05:6808:601:: with SMTP id y1mr14115396oih.27.1628515904272; Mon, 09 Aug 2021 06:31:44 -0700 (PDT) MIME-Version: 1.0 References: <31298797-f791-4ac5-cfda-c95d7c7958a4@linux-m68k.org> <380dd57-4b60-ac9c-508c-826d8ec1b0aa@linux-m68k.org> In-Reply-To: <380dd57-4b60-ac9c-508c-826d8ec1b0aa@linux-m68k.org> From: Mikael Pettersson Date: Mon, 9 Aug 2021 15:31:33 +0200 Message-ID: Subject: Re: [BISECTED][REGRESSION] 5.10.56 longterm kernel breakage on m68k/aranym To: Finn Thain Cc: Linux Kernel list , linux-m68k@lists.linux-m68k.org, stable@vger.kernel.org, Peter Xu Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 9, 2021 at 3:59 AM Finn Thain wrote: > > On Sun, 8 Aug 2021, Mikael Pettersson wrote: > > > On Sun, Aug 8, 2021 at 1:20 AM Finn Thain wrote: > > > > > > On Sat, 7 Aug 2021, Mikael Pettersson wrote: > > > > > > > I updated the 5.10 longterm kernel on one of my m68k/aranym VMs from > > > > 5.10.47 to 5.10.56, and the new kernel failed to boot: > > > > > > > > ARAnyM 1.1.0 > > > > Using config file: 'aranym1.headless.config' > > > > Could not open joystick 0 > > > > ARAnyM RTC Timer: /dev/rtc: Permission denied > > > > ARAnyM LILO: Error loading ramdisk 'root.bin' > > > > Blitter tried to read byte from register ff8a00 at 0077ee > > > > > > > > At this point it kept running, but produced no output to the console, > > > > and would never get to the point of starting user-space. Attaching gdb > > > > to aranym showed nothing interesting, i.e. it seemed to be executing > > > > normally. > > > > > > > > A git bisect identified the following commit between 5.10.52 and > > > > 5.10.53 as the culprit: > > > > # first bad commit: [9e1cf2d1ed37c934c9935f2c0b2f8b15d9355654] > > > > mm/userfaultfd: fix uffd-wp special cases for fork() > > > > > > > > > > That commit appeared in mainline between v5.13 and v5.14-rc1. Is mainline > > > also affected? e.g. v5.14-rc4. > > > > 5.14-rc4 boots fine. I suspect the commit has some dependency that > > hasn't been backported to 5.10 stable. > > > > On mainline, 9e1cf2d1ed3 is known as commit 8f34f1eac382 ("mm/userfaultfd: > fix uffd-wp special cases for fork()"). > > There are differences between the two commits that may be relevant. I > don't know. > > If you checkout 8f34f1eac382 and if that works, it would indicate either > missing dependencies in -stable, or those differences are important. > > OTOH, if 8f34f1eac382 fails in the same way as linux-5.10.y, it would > indicate that -stable is missing a fix that's present in v5.14-rc4. My initial bisect was wrong. I tried reverting 8f34f1eac382 from 5.10.57 but that made no difference, so I re-ran the git bisect with all known good points pre-marked. This landed on: # first bad commit: [ce6ee46e0f39ed97e23ebf7b5a565e0266a8a1a3] mm/page_alloc: fix memory map initialization for descending nodes Reverting _that_ from 5.10.57 does unbreak that kernel. Sorry about the confusion.