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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 C062AC388F7 for ; Fri, 13 Nov 2020 10:40:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6682D2224D for ; Fri, 13 Nov 2020 10:40:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726379AbgKMKku (ORCPT ); Fri, 13 Nov 2020 05:40:50 -0500 Received: from mx2.suse.de ([195.135.220.15]:39738 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726267AbgKMKkt (ORCPT ); Fri, 13 Nov 2020 05:40:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3AECFAEFB; Fri, 13 Nov 2020 10:40:48 +0000 (UTC) From: Vlastimil Babka To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alexander Potapenko , Kees Cook , Michal Hocko , David Hildenbrand , Mateusz Nosek , Laura Abbott , Vlastimil Babka , "Rafael J . Wysocki" Subject: [PATCH v3 3/5] kernel/power: allow hibernation with page_poison sanity checking Date: Fri, 13 Nov 2020 11:40:31 +0100 Message-Id: <20201113104033.22907-4-vbabka@suse.cz> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201113104033.22907-1-vbabka@suse.cz> References: <20201113104033.22907-1-vbabka@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Page poisoning used to be incompatible with hibernation, as the state of poisoned pages was lost after resume, thus enabling CONFIG_HIBERNATION forces CONFIG_PAGE_POISONING_NO_SANITY. For the same reason, the poisoning with zeroes variant CONFIG_PAGE_POISONING_ZERO used to disable hibernation. The latter restriction was removed by commit 1ad1410f632d ("PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO") and similarly for init_on_free by commit 18451f9f9e58 ("PM: hibernate: fix crashes with init_on_free=1") by making sure free pages are cleared after resume. We can use the same mechanism to instead poison free pages with PAGE_POISON after resume. This covers both zero and 0xAA patterns. Thus we can remove the Kconfig restriction that disables page poison sanity checking when hibernation is enabled. Signed-off-by: Vlastimil Babka Acked-by: Rafael J. Wysocki # for hibernation --- include/linux/mm.h | 1 + kernel/power/hibernate.c | 2 +- kernel/power/power.h | 2 +- kernel/power/snapshot.c | 14 +++++++++++--- mm/Kconfig.debug | 1 - 5 files changed, 14 insertions(+), 6 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 5ab5358be2b3..b15000085ff2 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2891,6 +2891,7 @@ static inline void kernel_unpoison_pages(struct page *page, int numpages) #else static inline bool page_poisoning_enabled(void) { return false; } static inline bool page_poisoning_enabled_static(void) { return false; } +static inline void __kernel_poison_pages(struct page *page, int nunmpages) { } static inline void kernel_poison_pages(struct page *page, int numpages) { } static inline void kernel_unpoison_pages(struct page *page, int numpages) { } #endif diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index d5d48404db37..559acef3fddb 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -329,7 +329,7 @@ static int create_image(int platform_mode) if (!in_suspend) { events_check_enabled = false; - clear_free_pages(); + clear_or_poison_free_pages(); } platform_leave(platform_mode); diff --git a/kernel/power/power.h b/kernel/power/power.h index 24f12d534515..778bf431ec02 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -106,7 +106,7 @@ extern int create_basic_memory_bitmaps(void); extern void free_basic_memory_bitmaps(void); extern int hibernate_preallocate_memory(void); -extern void clear_free_pages(void); +extern void clear_or_poison_free_pages(void); /** * Auxiliary structure used for reading the snapshot image data and diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index af534982062d..64b7aab9aee4 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1178,7 +1178,15 @@ void free_basic_memory_bitmaps(void) pr_debug("Basic memory bitmaps freed\n"); } -void clear_free_pages(void) +static void clear_or_poison_free_page(struct page *page) +{ + if (page_poisoning_enabled_static()) + __kernel_poison_pages(page, 1); + else if (want_init_on_free()) + clear_highpage(page); +} + +void clear_or_poison_free_pages(void) { struct memory_bitmap *bm = free_pages_map; unsigned long pfn; @@ -1186,12 +1194,12 @@ void clear_free_pages(void) if (WARN_ON(!(free_pages_map))) return; - if (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) || want_init_on_free()) { + if (page_poisoning_enabled() || want_init_on_free()) { memory_bm_position_reset(bm); pfn = memory_bm_next_pfn(bm); while (pfn != BM_END_OF_MAP) { if (pfn_valid(pfn)) - clear_highpage(pfn_to_page(pfn)); + clear_or_poison_free_page(pfn_to_page(pfn)); pfn = memory_bm_next_pfn(bm); } diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 864f129f1937..c57786ad5be9 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -64,7 +64,6 @@ config PAGE_OWNER config PAGE_POISONING bool "Poison pages after freeing" - select PAGE_POISONING_NO_SANITY if HIBERNATION help Fill the pages with poison patterns after free_pages() and verify the patterns before alloc_pages. The filling of the memory helps -- 2.29.2