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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 E3B58C07E99 for ; Mon, 12 Jul 2021 21:58:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 71C116117A for ; Mon, 12 Jul 2021 21:58:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 71C116117A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gentoo.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9B3956B0096; Mon, 12 Jul 2021 17:58:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 995DB6B0098; Mon, 12 Jul 2021 17:58:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 852BF6B0099; Mon, 12 Jul 2021 17:58:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0220.hostedemail.com [216.40.44.220]) by kanga.kvack.org (Postfix) with ESMTP id 5D8A96B0096 for ; Mon, 12 Jul 2021 17:58:27 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 75A9427DF0 for ; Mon, 12 Jul 2021 21:58:26 +0000 (UTC) X-FDA: 78355300212.23.D1DC0F8 Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) by imf24.hostedemail.com (Postfix) with ESMTP id D5214B0000AC for ; Mon, 12 Jul 2021 21:58:25 +0000 (UTC) Received: by sf.home (Postfix, from userid 1000) id 221D538CBE2B; Mon, 12 Jul 2021 22:58:19 +0100 (BST) From: Sergei Trofimovich To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Sergei Trofimovich , Andrew Morton , Kees Cook , Alexander Potapenko , Thomas Gleixner , Vlastimil Babka , bowsingbetee@pm.me Subject: [PATCH] mm: page_alloc: fix page_poison=1 / INIT_ON_ALLOC_DEFAULT_ON interaction Date: Mon, 12 Jul 2021 22:58:16 +0100 Message-Id: <20210712215816.1512739-1-slyfox@gentoo.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712005732.4f9bfa78@zn3> References: <20210712005732.4f9bfa78@zn3> MIME-Version: 1.0 Authentication-Results: imf24.hostedemail.com; dkim=none; spf=pass (imf24.hostedemail.com: domain of slyfox@gentoo.org designates 140.211.166.183 as permitted sender) smtp.mailfrom=slyfox@gentoo.org; dmarc=pass (policy=none) header.from=gentoo.org X-Rspamd-Server: rspam02 X-Stat-Signature: j7u47zdnzx5h4yrq1bdgtctk8iyt6ugp X-Rspamd-Queue-Id: D5214B0000AC X-HE-Tag: 1626127105-691997 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: To reproduce the failure we need the following system: - kernel command: page_poison=3D1 init_on_free=3D0 init_on_alloc=3D0 - kernel config: * CONFIG_INIT_ON_ALLOC_DEFAULT_ON=3Dy * CONFIG_INIT_ON_FREE_DEFAULT_ON=3Dy * CONFIG_PAGE_POISONING=3Dy 0000000085629bdd: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ..= .............. 0000000022861832: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ..= .............. 00000000c597f5b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ..= .............. CPU: 11 PID: 15195 Comm: bash Kdump: loaded Tainted: G U O = 5.13.1-gentoo-x86_64 #1 Hardware name: System manufacturer System Product Name/PRIME Z370-A, = BIOS 2801 01/13/2021 Call Trace: dump_stack+0x64/0x7c __kernel_unpoison_pages.cold+0x48/0x84 post_alloc_hook+0x60/0xa0 get_page_from_freelist+0xdb8/0x1000 __alloc_pages+0x163/0x2b0 __get_free_pages+0xc/0x30 pgd_alloc+0x2e/0x1a0 ? dup_mm+0x37/0x4f0 mm_init+0x185/0x270 dup_mm+0x6b/0x4f0 ? __lock_task_sighand+0x35/0x70 copy_process+0x190d/0x1b10 kernel_clone+0xba/0x3b0 __do_sys_clone+0x8f/0xb0 do_syscall_64+0x68/0x80 ? do_syscall_64+0x11/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Before the 51cba1eb ("init_on_alloc: Optimize static branches") init_on_alloc never enabled static branch by default. It could only be enabed explicitly by init_mem_debugging_and_hardening(). But after the 51cba1eb static branch could already be enabled by default. There was no code to ever disable it. That caused page_poison=3D1 / init_on_free=3D1 conflict. This change extends init_mem_debugging_and_hardening() to also disable static branch disabling. CC: Andrew Morton CC: Kees Cook CC: Alexander Potapenko CC: Thomas Gleixner CC: Vlastimil Babka CC: linux-mm@kvack.org Reported-by: bowsingbetee@pm.me Reported-by: Mikhail Morfikov Fixes: 51cba1eb ("init_on_alloc: Optimize static branches") Signed-off-by: Sergei Trofimovich --- mm/page_alloc.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3b97e17806be..46cb4a9c2b50 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -840,18 +840,22 @@ void init_mem_debugging_and_hardening(void) } #endif =20 - if (_init_on_alloc_enabled_early) { - if (page_poisoning_requested) + if (_init_on_alloc_enabled_early || + IS_ENABLED(CONFIG_INIT_ON_ALLOC_DEFAULT_ON)) { + if (page_poisoning_requested) { pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, " "will take precedence over init_on_alloc\n"); - else + static_branch_disable(&init_on_alloc); + } else static_branch_enable(&init_on_alloc); } - if (_init_on_free_enabled_early) { - if (page_poisoning_requested) + if (_init_on_free_enabled_early || + IS_ENABLED(CONFIG_INIT_ON_FREE_DEFAULT_ON)) { + if (page_poisoning_requested) { pr_info("mem auto-init: CONFIG_PAGE_POISONING is on, " "will take precedence over init_on_free\n"); - else + static_branch_disable(&init_on_free); + } else static_branch_enable(&init_on_free); } =20 --=20 2.32.0