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 ACE0EC433FE for ; Tue, 8 Nov 2022 22:00:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230029AbiKHWAB (ORCPT ); Tue, 8 Nov 2022 17:00:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230032AbiKHV7z (ORCPT ); Tue, 8 Nov 2022 16:59:55 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D88B322BC4 for ; Tue, 8 Nov 2022 13:59:53 -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 7737A617AF for ; Tue, 8 Nov 2022 21:59:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE4F0C433C1; Tue, 8 Nov 2022 21:59:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1667944792; bh=Ye82lchll+d3Qizh2nW7Kgqd0gFfvuKH5LgothN/tVo=; h=Date:To:From:Subject:From; b=QoGiuYwRUGXtgS+qCIKQYM852CH//N1JsPyNV0Ngyso/+LB7N4I3W2npaie0YGr7Y NRa6MnXl5mFt9oBLddsU457zkI5EvoQ3vU9Le9CzBPEDh1NKKJRhceBpTmbXRKDhIy cHkIxsdBe/L7l5zu+Ds0cDzRk7JW7GWz+M81DyA8= Date: Tue, 08 Nov 2022 13:59:52 -0800 To: mm-commits@vger.kernel.org, vbabka@suse.cz, torvalds@linux-foundation.org, rppt@kernel.org, peterx@redhat.com, npiggin@gmail.com, namit@vmware.com, mpe@ellerman.id.au, mgorman@techsingularity.net, hughd@google.com, david@fromorbit.com, anshuman.khandual@arm.com, aarcange@redhat.com, david@redhat.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-mprotect-factor-out-check-whether-manual-pte-write-upgrades-are-required.patch added to mm-unstable branch Message-Id: <20221108215952.CE4F0C433C1@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/mprotect: factor out check whether manual PTE write upgrades are required has been added to the -mm mm-unstable branch. Its filename is mm-mprotect-factor-out-check-whether-manual-pte-write-upgrades-are-required.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mprotect-factor-out-check-whether-manual-pte-write-upgrades-are-required.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: David Hildenbrand Subject: mm/mprotect: factor out check whether manual PTE write upgrades are required Date: Tue, 8 Nov 2022 18:46:49 +0100 Let's factor the check out into vma_wants_manual_pte_write_upgrade(), to be reused in NUMA hinting fault context soon. Link: https://lkml.kernel.org/r/20221108174652.198904-5-david@redhat.com Signed-off-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Anshuman Khandual Cc: Dave Chinner Cc: Hugh Dickins Cc: Linus Torvalds Cc: Mel Gorman Cc: Michael Ellerman Cc: Mike Rapoport Cc: Nadav Amit Cc: Nicholas Piggin Cc: Peter Xu Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/mm.h | 16 ++++++++++++++-- mm/mprotect.c | 17 ++++------------- 2 files changed, 18 insertions(+), 15 deletions(-) --- a/include/linux/mm.h~mm-mprotect-factor-out-check-whether-manual-pte-write-upgrades-are-required +++ a/include/linux/mm.h @@ -2016,6 +2016,20 @@ extern unsigned long move_page_tables(st #define MM_CP_UFFD_WP_ALL (MM_CP_UFFD_WP | \ MM_CP_UFFD_WP_RESOLVE) +int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot); +static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma) +{ + /* + * We want to check manually if we can change individual PTEs writable + * if we can't do that automatically for all PTEs in a mapping. For + * private mappings, that's always the case when we have write + * permissions as we properly have to handle COW. + */ + if (vma->vm_flags & VM_SHARED) + return vma_wants_writenotify(vma, vma->vm_page_prot); + return !!(vma->vm_flags & VM_WRITE); + +} extern unsigned long change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long start, unsigned long end, pgprot_t newprot, @@ -2155,8 +2169,6 @@ static inline int pte_devmap(pte_t pte) } #endif -int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot); - extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl); static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, --- a/mm/mprotect.c~mm-mprotect-factor-out-check-whether-manual-pte-write-upgrades-are-required +++ a/mm/mprotect.c @@ -558,8 +558,8 @@ mprotect_fixup(struct mmu_gather *tlb, s struct mm_struct *mm = vma->vm_mm; unsigned long oldflags = vma->vm_flags; long nrpages = (end - start) >> PAGE_SHIFT; + unsigned int mm_cp_flags = 0; unsigned long charged = 0; - bool try_change_writable; pgoff_t pgoff; int error; @@ -637,20 +637,11 @@ success: * held in write mode. */ vma->vm_flags = newflags; - /* - * We want to check manually if we can change individual PTEs writable - * if we can't do that automatically for all PTEs in a mapping. For - * private mappings, that's always the case when we have write - * permissions as we properly have to handle COW. - */ - if (vma->vm_flags & VM_SHARED) - try_change_writable = vma_wants_writenotify(vma, vma->vm_page_prot); - else - try_change_writable = !!(vma->vm_flags & VM_WRITE); + if (vma_wants_manual_pte_write_upgrade(vma)) + mm_cp_flags |= MM_CP_TRY_CHANGE_WRITABLE; vma_set_page_prot(vma); - change_protection(tlb, vma, start, end, vma->vm_page_prot, - try_change_writable ? MM_CP_TRY_CHANGE_WRITABLE : 0); + change_protection(tlb, vma, start, end, vma->vm_page_prot, mm_cp_flags); /* * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major _ Patches currently in -mm which might be from david@redhat.com are selftests-vm-anon_cow-test-cow-handling-of-anonymous-memory.patch selftests-vm-anon_cow-test-cow-handling-of-anonymous-memory-fix.patch selftests-vm-factor-out-pagemap_is_populated-into-vm_util.patch selftests-vm-anon_cow-thp-tests.patch selftests-vm-anon_cow-hugetlb-tests.patch selftests-vm-anon_cow-add-liburing-test-cases.patch selftests-vm-anon_cow-add-liburing-test-cases-fix.patch mm-gup_test-start-stop-read-functionality-for-pin-longterm-test.patch mm-gup_test-start-stop-read-functionality-for-pin-longterm-test-fix.patch selftests-vm-anon_cow-add-r-o-longterm-tests-via-gup_test.patch selftests-vm-add-ksm-unmerge-tests.patch mm-pagewalk-dont-trigger-test_walk-in-walk_page_vma.patch selftests-vm-add-test-to-measure-madv_unmergeable-performance.patch mm-ksm-simplify-break_ksm-to-not-rely-on-vm_fault_write.patch mm-remove-vm_fault_write.patch mm-ksm-fix-ksm-cow-breaking-with-userfaultfd-wp-via-fault_flag_unshare.patch mm-pagewalk-add-walk_page_range_vma.patch mm-ksm-convert-break_ksm-to-use-walk_page_range_vma.patch mm-gup-remove-foll_migration.patch mm-mprotect-minor-can_change_pte_writable-cleanups.patch mm-huge_memory-try-avoiding-write-faults-when-changing-pmd-protection.patch mm-mprotect-factor-out-check-whether-manual-pte-write-upgrades-are-required.patch mm-autonuma-use-can_change_ptepmd_writable-to-replace-savedwrite.patch mm-remove-unused-savedwrite-infrastructure.patch selftests-vm-anon_cow-add-mprotect-optimization-tests.patch