From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 55CB52356DA for ; Tue, 12 Aug 2025 06:01:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754978485; cv=none; b=m3qQBZckRc0Bxcv+TqB0Q6fUojigG67w1jmzWGMv2BzZf2kc8wFmoDDvIdWqSA1zthwn7ZZYTqx1CcJ+Pi7xidvVizFx2hlNT7s2aQkFj9+KpetmtVM3SmxWVSYsRkIrln1uslN02cyRmZuqRG9imcCZJ3RUqd2yAsu3dBNjdS0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754978485; c=relaxed/simple; bh=S4pGazGBLvVXjjNTIqr1/ZLtc6jveiGfk905Xpbcu9M=; h=Date:To:From:Subject:Message-Id; b=ilxTXPEGKPWYm6g8Ys9Ku629W13+55PNjQpQf3ATGz14a88JGG5LuSUHbGJfEdevlru/1LoDI+zmFLSIR8FZvhxH52U1F3WX2FENzmDuCNRPahnR9w5qJhIA4JdztVVBvzmNV3dGtXwNfs0F5QqRTsDXkptGi99YBYV1FR3ICYs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=1z8CScop; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="1z8CScop" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9344C4CEF0; Tue, 12 Aug 2025 06:01:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1754978484; bh=S4pGazGBLvVXjjNTIqr1/ZLtc6jveiGfk905Xpbcu9M=; h=Date:To:From:Subject:From; b=1z8CScop7r5NJw9+ce2U+89qMkIcgVK7gxYPyk1ItP2VlFgoVgrlPOqqlL5DsIabu kLwIZPsJHKqbGm0MjCtFucaWwfMHC4ZIPn4pMq4jqaOsjqIypopig/mHfn+dQffYRy M+lj7o0DUwnY2A36mK6KTLObdWSrPEBvlbd1b1Qw= Date: Mon, 11 Aug 2025 23:01:24 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,yangyicong@hisilicon.com,yang@os.amperecomputing.com,willy@infradead.org,will@kernel.org,vbabka@suse.cz,ryan.roberts@arm.com,quic_zhenhuah@quicinc.com,peterx@redhat.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,kevin.brodsky@arm.com,joey.gouly@arm.com,jannh@google.com,ioworker0@gmail.com,hughd@google.com,david@redhat.com,christophe.leroy@csgroup.eu,catalin.marinas@arm.com,baohua@kernel.org,anshuman.khandual@arm.com,dev.jain@arm.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-pass-page-directly-instead-of-using-folio_page.patch removed from -mm tree Message-Id: <20250812060124.C9344C4CEF0@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: pass page directly instead of using folio_page has been removed from the -mm tree. Its filename was mm-pass-page-directly-instead-of-using-folio_page.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Dev Jain Subject: mm: pass page directly instead of using folio_page Date: Wed, 6 Aug 2025 20:26:11 +0530 In commit_anon_folio_batch(), we iterate over all pages pointed to by the PTE batch. Therefore we need to know the first page of the batch; currently we derive that via folio_page(folio, 0), but, that takes us to the first (head) page of the folio instead - our PTE batch may lie in the middle of the folio, leading to incorrectness. Bite the bullet and throw away the micro-optimization of reusing the folio in favour of code simplicity. Derive the page and the folio in change_pte_range, and pass the page too to commit_anon_folio_batch to fix the aforementioned issue. Link: https://lkml.kernel.org/r/20250806145611.3962-1-dev.jain@arm.com Fixes: cac1db8c3aad ("mm: optimize mprotect() by PTE batching") Reported-by: syzbot+57bcc752f0df8bb1365c@syzkaller.appspotmail.com Signed-off-by: Dev Jain Reviewed-by: Lorenzo Stoakes Debugged-by: David Hildenbrand Acked-by: David Hildenbrand Cc: Anshuman Khandual Cc: Barry Song Cc: Catalin Marinas Cc: Christophe Leroy Cc: Hugh Dickins Cc: Jann Horn Cc: Joey Gouly Cc: Kevin Brodsky Cc: Lance Yang Cc: Liam Howlett Cc: Matthew Wilcox (Oracle) Cc: Peter Xu Cc: Ryan Roberts Cc: Vlastimil Babka Cc: Will Deacon Cc: Yang Shi Cc: Yicong Yang Cc: Zhenhua Huang Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/mprotect.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) --- a/mm/mprotect.c~mm-pass-page-directly-instead-of-using-folio_page +++ a/mm/mprotect.c @@ -120,9 +120,8 @@ static int mprotect_folio_pte_batch(stru static bool prot_numa_skip(struct vm_area_struct *vma, unsigned long addr, pte_t oldpte, pte_t *pte, int target_node, - struct folio **foliop) + struct folio *folio) { - struct folio *folio = NULL; bool ret = true; bool toptier; int nid; @@ -131,7 +130,6 @@ static bool prot_numa_skip(struct vm_are if (pte_protnone(oldpte)) goto skip; - folio = vm_normal_folio(vma, addr, oldpte); if (!folio) goto skip; @@ -173,7 +171,6 @@ static bool prot_numa_skip(struct vm_are folio_xchg_access_time(folio, jiffies_to_msecs(jiffies)); skip: - *foliop = folio; return ret; } @@ -231,10 +228,9 @@ static int page_anon_exclusive_sub_batch * retrieve sub-batches. */ static void commit_anon_folio_batch(struct vm_area_struct *vma, - struct folio *folio, unsigned long addr, pte_t *ptep, + struct folio *folio, struct page *first_page, unsigned long addr, pte_t *ptep, pte_t oldpte, pte_t ptent, int nr_ptes, struct mmu_gather *tlb) { - struct page *first_page = folio_page(folio, 0); bool expected_anon_exclusive; int sub_batch_idx = 0; int len; @@ -251,7 +247,7 @@ static void commit_anon_folio_batch(stru } static void set_write_prot_commit_flush_ptes(struct vm_area_struct *vma, - struct folio *folio, unsigned long addr, pte_t *ptep, + struct folio *folio, struct page *page, unsigned long addr, pte_t *ptep, pte_t oldpte, pte_t ptent, int nr_ptes, struct mmu_gather *tlb) { bool set_write; @@ -270,7 +266,7 @@ static void set_write_prot_commit_flush_ /* idx = */ 0, set_write, tlb); return; } - commit_anon_folio_batch(vma, folio, addr, ptep, oldpte, ptent, nr_ptes, tlb); + commit_anon_folio_batch(vma, folio, page, addr, ptep, oldpte, ptent, nr_ptes, tlb); } static long change_pte_range(struct mmu_gather *tlb, @@ -305,15 +301,19 @@ static long change_pte_range(struct mmu_ const fpb_t flags = FPB_RESPECT_SOFT_DIRTY | FPB_RESPECT_WRITE; int max_nr_ptes = (end - addr) >> PAGE_SHIFT; struct folio *folio = NULL; + struct page *page; pte_t ptent; + page = vm_normal_page(vma, addr, oldpte); + if (page) + folio = page_folio(page); /* * Avoid trapping faults against the zero or KSM * pages. See similar comment in change_huge_pmd. */ if (prot_numa) { int ret = prot_numa_skip(vma, addr, oldpte, pte, - target_node, &folio); + target_node, folio); if (ret) { /* determine batch to skip */ @@ -323,9 +323,6 @@ static long change_pte_range(struct mmu_ } } - if (!folio) - folio = vm_normal_folio(vma, addr, oldpte); - nr_ptes = mprotect_folio_pte_batch(folio, pte, oldpte, max_nr_ptes, flags); oldpte = modify_prot_start_ptes(vma, addr, pte, nr_ptes); @@ -351,7 +348,7 @@ static long change_pte_range(struct mmu_ */ if ((cp_flags & MM_CP_TRY_CHANGE_WRITABLE) && !pte_write(ptent)) - set_write_prot_commit_flush_ptes(vma, folio, + set_write_prot_commit_flush_ptes(vma, folio, page, addr, pte, oldpte, ptent, nr_ptes, tlb); else prot_commit_flush_ptes(vma, addr, pte, oldpte, ptent, _ Patches currently in -mm which might be from dev.jain@arm.com are