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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 4522AC33CA8 for ; Mon, 13 Jan 2020 09:26:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2312C24125 for ; Mon, 13 Jan 2020 09:26:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725992AbgAMJ0N (ORCPT ); Mon, 13 Jan 2020 04:26:13 -0500 Received: from mail.sig21.net ([80.244.240.74]:38390 "EHLO mail.sig21.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726480AbgAMJ0N (ORCPT ); Mon, 13 Jan 2020 04:26:13 -0500 Received: from localhorst ([127.0.0.1]) by mail.sig21.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1iqvz6-0006Qo-Ur ; Mon, 13 Jan 2020 10:26:11 +0100 Received: from js by abc.local with local (Exim 4.93) (envelope-from ) id 1iqvz2-00075O-HY; Mon, 13 Jan 2020 10:26:04 +0100 Date: Mon, 13 Jan 2020 10:26:04 +0100 From: Johannes Stezenbach To: linux-pm@vger.kernel.org Cc: "Rafael J. Wysocki" , Alexander Potapenko Subject: Re: init_on_free breaks hibernate Message-ID: <20200113092604.GA26365@sig21.net> References: <20191223211309.GA4609@sig21.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191223211309.GA4609@sig21.net> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi, On Mon, Dec 23, 2019 at 10:13:09PM +0100, Johannes Stezenbach wrote: > I upgraded the kernel on one of my machines to 5.3.18 (from 5.2.x) > and found it failed after resume from hibernate due to what seemed > to be memory corruption. I had a hunch it could be related to > CONFIG_INIT_ON_ALLOC_DEFAULT_ON or CONFIG_INIT_ON_FREE_DEFAULT_ON, > and a quick web search found this which seems to confirm: > https://bbs.archlinux.org/viewtopic.php?pid=1877845#p1877845 > > I rebuilt the kernel with CONFIG_INIT_ON_FREE_DEFAULT_ON disabled, > and hibernate works again. I'm fine with this workaround and > just wanted to share this information. > > The commit that introduces CONFIG_INIT_ON_FREE_DEFAULT_ON: > 6471384af2a6 mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options I tested 5.4.11 and current git master (b07f636fca1c8) in Qemu and was able to reproduce the issue in both. Basically I followed the description here http://ncmiller.github.io/2016/05/14/linux-and-qemu.html to build a minimal image using busybox (I'm using the binary from Debian's busybox-static package), then added s swap image (-drive file=disk.img,if=virtio), do "mkswap /dev/vda" the first time. hibernate: swapon /dev/vda; echo disk >/sys/power/state resume: echo 254:0 >/sys/power/resume Since busybox is very light on memory usage it doesn't trigger immediately, but these commands seem to do it reliably: dmesg | gzip >/dev/null find /sys | bzip2 | sha512sum my initramfs: 6012997 4 drwxr-xr-x 4 js js 4096 Jan 8 21:25 initramfs 6022584 4 drwxr-xr-x 2 js js 4096 Jan 8 21:21 initramfs/dev 5909013 4 -rwxr-xr-x 1 js js 514 Jan 8 21:25 initramfs/init 6012998 4 drwxr-xr-x 2 js js 4096 Jan 8 20:41 initramfs/bin 5909011 1904 -rwxr-xr-x 1 js js 1945856 Apr 1 2019 initramfs/bin/busybox 5909012 0 lrwxrwxrwx 1 js js 7 Feb 14 2018 initramfs/bin/sh -> busybox my /init: #!/bin/sh PATH=/bin export PATH # Create dirs /bin/busybox mkdir -p /proc /sys /etc /tmp /usr /bin/busybox ln -s /bin /sbin /bin/busybox ln -s /bin /usr/bin /bin/busybox ln -s /bin /usr/sbin # Create all the symlinks to busybox /bin/busybox --install -s mount -t proc proc /proc mount -t sysfs sysfs /sys mount -t devtmpfs devtmpfs /dev echo -e "\nBoot took $(cut -d' ' -f1 /proc/uptime) seconds\n" # shell where ^C works setsid busybox cttyhack sh # avoid "PID 1 exited" oops poweroff -f --------- qemu-system-x86_64 -m 128 -enable-kvm \ -kernel ../linux/arch/x86/boot/bzImage \ -initrd initramfs.cpio \ -drive file=disk.img,if=virtio \ -nographic -append "console=ttyS0 init_on_alloc=1 init_on_free=1" Johannes