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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_RED,USER_AGENT_GIT autolearn=unavailable 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 41BB3C4646E for ; Mon, 10 May 2021 12:37:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 192F26145F for ; Mon, 10 May 2021 12:37:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343731AbhEJMgF (ORCPT ); Mon, 10 May 2021 08:36:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:53778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235751AbhEJLNo (ORCPT ); Mon, 10 May 2021 07:13:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7C6276101B; Mon, 10 May 2021 11:10:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620645027; bh=so06xh22x+eOvI3lB5XXERypi5HW9pgp260kwFsvtCs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l5qiTtX+V3Z+S+FWFSlAi94GHMe6DHmf+dYoKE0YH8LNIhphuX5HJQaWCaHzVaa5G lWuJx1ptJ8mzmZ8DcICYZ1dXD+drEeMBw5KW9e5LML7U+gMJAzIvqXzBtTLDLcsBr0 lT1WfpNsbf4D7yUcSM0nBy3vurMbV+hCWJI6dshI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sergei Trofimovich , Vlastimil Babka , David Hildenbrand , Andrey Konovalov , Andrew Morton , Linus Torvalds Subject: [PATCH 5.12 321/384] mm: page_alloc: ignore init_on_free=1 for debug_pagealloc=1 Date: Mon, 10 May 2021 12:21:50 +0200 Message-Id: <20210510102025.378166191@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102014.849075526@linuxfoundation.org> References: <20210510102014.849075526@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sergei Trofimovich commit 9df65f522536719682bccd24245ff94db956256c upstream. On !ARCH_SUPPORTS_DEBUG_PAGEALLOC (like ia64) debug_pagealloc=1 implies page_poison=on: if (page_poisoning_enabled() || (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && debug_pagealloc_enabled())) static_branch_enable(&_page_poisoning_enabled); page_poison=on needs to override init_on_free=1. Before the change it did not work as expected for the following case: - have PAGE_POISONING=y - have page_poison unset - have !ARCH_SUPPORTS_DEBUG_PAGEALLOC arch (like ia64) - have init_on_free=1 - have debug_pagealloc=1 That way we get both keys enabled: - static_branch_enable(&init_on_free); - static_branch_enable(&_page_poisoning_enabled); which leads to poisoned pages returned for __GFP_ZERO pages. After the change we execute only: - static_branch_enable(&_page_poisoning_enabled); and ignore init_on_free=1. Link: https://lkml.kernel.org/r/20210329222555.3077928-1-slyfox@gentoo.org Link: https://lkml.org/lkml/2021/3/26/443 Fixes: 8db26a3d4735 ("mm, page_poison: use static key more efficiently") Signed-off-by: Sergei Trofimovich Acked-by: Vlastimil Babka Reviewed-by: David Hildenbrand Cc: Andrey Konovalov Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/page_alloc.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -764,32 +764,36 @@ static inline void clear_page_guard(stru */ void init_mem_debugging_and_hardening(void) { + bool page_poisoning_requested = false; + +#ifdef CONFIG_PAGE_POISONING + /* + * Page poisoning is debug page alloc for some arches. If + * either of those options are enabled, enable poisoning. + */ + if (page_poisoning_enabled() || + (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && + debug_pagealloc_enabled())) { + static_branch_enable(&_page_poisoning_enabled); + page_poisoning_requested = true; + } +#endif + if (_init_on_alloc_enabled_early) { - if (page_poisoning_enabled()) + 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_enable(&init_on_alloc); } if (_init_on_free_enabled_early) { - if (page_poisoning_enabled()) + 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_enable(&init_on_free); } -#ifdef CONFIG_PAGE_POISONING - /* - * Page poisoning is debug page alloc for some arches. If - * either of those options are enabled, enable poisoning. - */ - if (page_poisoning_enabled() || - (!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) && - debug_pagealloc_enabled())) - static_branch_enable(&_page_poisoning_enabled); -#endif - #ifdef CONFIG_DEBUG_PAGEALLOC if (!debug_pagealloc_enabled()) return;