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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E00D8C433EF for ; Fri, 11 Mar 2022 03:02:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234969AbiCKDDs (ORCPT ); Thu, 10 Mar 2022 22:03:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345901AbiCKDDq (ORCPT ); Thu, 10 Mar 2022 22:03:46 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4477EB561D for ; Thu, 10 Mar 2022 19:02:38 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4B35E6127C for ; Fri, 11 Mar 2022 03:02:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99DCFC340EB; Fri, 11 Mar 2022 03:02:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1646967757; bh=pd/+OSuqCF3biaya2IVpDcEf8o/spxImvBRxRzGUIYQ=; h=Date:To:From:Subject:From; b=dEQjbc7PmTyIq83nHlYoHHPulJ/Ut/aCM9DJ8TvZ16rYmZmTGdGFlGURi1zLKzrq8 hiBpb7O0IhlA2fHib9P5B17NovCYvIZ6bHgHBPtf/YnNmfWWiXRwS61KLwcE20I1MW DwssjgXr1T7abFk0k9BSqkh0FZVu4fkfegT7hWTs= Date: Thu, 10 Mar 2022 19:02:36 -0800 To: mm-commits@vger.kernel.org, weixugc@google.com, vbabka@suse.cz, shakeelb@google.com, rientjes@google.com, mhocko@kernel.org, hughd@google.com, gthelen@google.com, edumazet@google.com, mgorman@techsingularity.net, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-page_alloc-check-high-order-pages-for-corruption-during-pcp-operations.patch added to -mm tree Message-Id: <20220311030237.99DCFC340EB@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/page_alloc: check high-order pages for corruption during PCP operations has been added to the -mm tree. Its filename is mm-page_alloc-check-high-order-pages-for-corruption-during-pcp-operations.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-check-high-order-pages-for-corruption-during-pcp-operations.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-check-high-order-pages-for-corruption-during-pcp-operations.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Mel Gorman Subject: mm/page_alloc: check high-order pages for corruption during PCP operations Eric Dumazet pointed out that commit 44042b449872 ("mm/page_alloc: allow high-order pages to be stored on the per-cpu lists") only checks the head page during PCP refill and allocation operations. This was an oversight and all pages should be checked. This will incur a small performance penalty but it's necessary for correctness. Link: https://lkml.kernel.org/r/20220310092456.GJ15701@techsingularity.net Fixes: 44042b449872 ("mm/page_alloc: allow high-order pages to be stored on the per-cpu lists") Signed-off-by: Mel Gorman Reported-by: Eric Dumazet Acked-by: Eric Dumazet Reviewed-by: Shakeel Butt Cc: Vlastimil Babka Cc: Michal Hocko Cc: Wei Xu Cc: Greg Thelen Cc: Hugh Dickins Cc: David Rientjes Signed-off-by: Andrew Morton --- mm/page_alloc.c | 46 +++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-check-high-order-pages-for-corruption-during-pcp-operations +++ a/mm/page_alloc.c @@ -2291,23 +2291,36 @@ static inline int check_new_page(struct return 1; } +static bool check_new_pages(struct page *page, unsigned int order) +{ + int i; + for (i = 0; i < (1 << order); i++) { + struct page *p = page + i; + + if (unlikely(check_new_page(p))) + return true; + } + + return false; +} + #ifdef CONFIG_DEBUG_VM /* * With DEBUG_VM enabled, order-0 pages are checked for expected state when * being allocated from pcp lists. With debug_pagealloc also enabled, they are * also checked when pcp lists are refilled from the free lists. */ -static inline bool check_pcp_refill(struct page *page) +static inline bool check_pcp_refill(struct page *page, unsigned int order) { if (debug_pagealloc_enabled_static()) - return check_new_page(page); + return check_new_pages(page, order); else return false; } -static inline bool check_new_pcp(struct page *page) +static inline bool check_new_pcp(struct page *page, unsigned int order) { - return check_new_page(page); + return check_new_pages(page, order); } #else /* @@ -2315,32 +2328,19 @@ static inline bool check_new_pcp(struct * when pcp lists are being refilled from the free lists. With debug_pagealloc * enabled, they are also checked when being allocated from the pcp lists. */ -static inline bool check_pcp_refill(struct page *page) +static inline bool check_pcp_refill(struct page *page, unsigned int order) { - return check_new_page(page); + return check_new_pages(page, order); } -static inline bool check_new_pcp(struct page *page) +static inline bool check_new_pcp(struct page *page, unsigned int order) { if (debug_pagealloc_enabled_static()) - return check_new_page(page); + return check_new_pages(page, order); else return false; } #endif /* CONFIG_DEBUG_VM */ -static bool check_new_pages(struct page *page, unsigned int order) -{ - int i; - for (i = 0; i < (1 << order); i++) { - struct page *p = page + i; - - if (unlikely(check_new_page(p))) - return true; - } - - return false; -} - inline void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags) { @@ -2982,7 +2982,7 @@ static int rmqueue_bulk(struct zone *zon if (unlikely(page == NULL)) break; - if (unlikely(check_pcp_refill(page))) + if (unlikely(check_pcp_refill(page, order))) continue; /* @@ -3600,7 +3600,7 @@ struct page *__rmqueue_pcplist(struct zo page = list_first_entry(list, struct page, lru); list_del(&page->lru); pcp->count -= 1 << order; - } while (check_new_pcp(page)); + } while (check_new_pcp(page, order)); return page; } _ Patches currently in -mm which might be from mgorman@techsingularity.net are mm-page_alloc-fetch-the-correct-pcp-buddy-during-bulk-free.patch mm-page_alloc-track-range-of-active-pcp-lists-during-bulk-free.patch mm-page_alloc-simplify-how-many-pages-are-selected-per-pcp-list-during-bulk-free.patch mm-page_alloc-drain-the-requested-list-first-during-bulk-free.patch mm-page_alloc-free-pages-in-a-single-pass-during-bulk-free.patch mm-page_alloc-limit-number-of-high-order-pages-on-pcp-during-bulk-free.patch mm-page_alloc-do-not-prefetch-buddies-during-bulk-free.patch mm-page_alloc-check-high-order-pages-for-corruption-during-pcp-operations.patch