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=-3.8 required=3.0 tests=BAYES_00, 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 28C59C47082 for ; Tue, 8 Jun 2021 16:52:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0370C6127A for ; Tue, 8 Jun 2021 16:52:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0370C6127A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=dominikbrodowski.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 95BD86B006E; Tue, 8 Jun 2021 12:52:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 932D46B0070; Tue, 8 Jun 2021 12:52:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 822106B0071; Tue, 8 Jun 2021 12:52:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0066.hostedemail.com [216.40.44.66]) by kanga.kvack.org (Postfix) with ESMTP id 52F7D6B006E for ; Tue, 8 Jun 2021 12:52:23 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id E80018778 for ; Tue, 8 Jun 2021 16:52:22 +0000 (UTC) X-FDA: 78231149724.04.8DA076D Received: from isilmar-4.linta.de (isilmar-4.linta.de [136.243.71.142]) by imf06.hostedemail.com (Postfix) with ESMTP id 25DD7C00F785 for ; Tue, 8 Jun 2021 16:52:19 +0000 (UTC) X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES Received: from light.dominikbrodowski.net (brodo.linta [10.2.0.102]) by isilmar-4.linta.de (Postfix) with ESMTPSA id 2237F20002B; Tue, 8 Jun 2021 16:52:20 +0000 (UTC) Received: by light.dominikbrodowski.net (Postfix, from userid 1000) id 64253210DA; Tue, 8 Jun 2021 18:50:56 +0200 (CEST) Date: Tue, 8 Jun 2021 18:50:56 +0200 From: Dominik Brodowski To: keescook@chromium.org, andreyknvl@google.com Cc: linux-hardening@vger.kernel.org, linux-mm@kvack.org, tglx@linutronix.de, glider@google.com, vbabka@suse.cz Subject: regresion v5.13-rc1+ - page_poison broken since 51cba1ebc60d Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Authentication-Results: imf06.hostedemail.com; dkim=none; spf=none (imf06.hostedemail.com: domain of linux@dominikbrodowski.net has no SPF policy when checking 136.243.71.142) smtp.mailfrom=linux@dominikbrodowski.net; dmarc=none X-Stat-Signature: tpr1pwecgz9udinfeuy36ex8mcwhtggb X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 25DD7C00F785 X-HE-Tag: 1623171139-621818 X-Bogosity: Ham, tests=bogofilter, spamicity=0.016540, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Kees, Andrey, a "git bisect" points to commit 51cba1ebc60d ("init_on_alloc: Optimize static branches") as breaking page poisoning ("page_poison=on"). Starting with this commit, booting -- with this option enabled on the kernel command line -- hangs quite early, before anything meaningful is printed. Booting 51cba1ebc60d without this option proceeds just fine. Since 1bb5eab30d68 ("kasan, mm: integrate page_alloc init with HW_TAGS") the behaviour becomes different: Since that commit, booting with "page_poison=on" and "slub_debug=P" continues up to the initramfs stage, but then fails quite spectacularly with a large number of page poisonings being reported. While "page_poision=on slub_debug=P" doesn't seem to be necessary any longer if CONFIG_INIT_ON_ALLOC_DEFAULT_ON and CONFIG_INIT_ON_FREE_DEFAULT_ON are enabled[*], this still looks like a regression. Thanks, Dominik [*] https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings