From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 CB6EA449B23 for ; Mon, 20 Jul 2026 19:48:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784576913; cv=none; b=rkgyJR7CPtVa9NeoofGf/qy/3haErVC/WEm8Esh3H608dhiMFzupWU+EBH/8cA5arRwwsy2WF2Kasz9WBlFiKelI8BjEPI+lLPakjtH2LFcJ9cUNURGSt56m41eEHOrNrvKXgckqTvA+l1gVvr+BIpka7zL4WiCx0VGKEQop0aU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784576913; c=relaxed/simple; bh=Gm90TC3mj80Hy836NzasWGW8FPaTkBQcNcUvw//n0m4=; h=Date:To:From:Subject:Message-Id; b=FRFO4jUardTtc2+bdyOGKyy28RcHqfLWvUPXAf5vtkyDtjTyZ3HjnnZBc9VKPAhQrBeU0J39nVBM6W2sMg/A/q9Xb/NQXzsA74NWeB+H4wcjL/tVLjleqMslDGMAhqxjQqrnPGPVY+Ia2m/vIc63c9Q2UO0oAB2z8eIGzWf2mRA= 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=i8ejcFli; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="i8ejcFli" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A024F1F000E9; Mon, 20 Jul 2026 19:48:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1784576911; bh=TDHskh7JTCmx3rAvWeppCH0jppzRO8OtHNZ7IVr5r44=; h=Date:To:From:Subject; b=i8ejcFliQ/n0fIDtYJ1P6HR2uAH/NXRGAaU5S72qsqwmdJrh0F9xrD7uGbS0QBG71 6fWxjoKI7cpRXGAoaxX4msYvcCV46Jvo24OkfAxAqmZVq3mQMMXIaznGqauk7H9U9A TUP3DHtLlJQM1ocnNvMApvPm5Jc9AIVp0gpO0x8A= Date: Mon, 20 Jul 2026 12:48:31 -0700 To: mm-commits@vger.kernel.org,ljs@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-introduce-linear_virt_page_index.patch added to mm-new branch Message-Id: <20260720194831.A024F1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: introduce linear_virt_page_index() has been added to the -mm mm-new branch. Its filename is mm-introduce-linear_virt_page_index.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-introduce-linear_virt_page_index.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next 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 various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "Lorenzo Stoakes (ARM)" Subject: mm: introduce linear_virt_page_index() Date: Mon, 20 Jul 2026 15:38:28 +0100 This function provides the virtual equivalent of linear_page_index(), instead offsetting based on the virtual page offset of the VMA. It is valid only for anonymous or MAP_PRIVATE file-backed mappings. It must not be called for shared file-backed mappings. For pure anon VMAs, this will be equal to linear_page_index(). We implement the algorithm in __linear_virt_page_index(), which is provided for internal mm code that might be interacting with shared VMAs. In linear_virt_page_index() we assert that both of these invariants are true. Note that MAP_PRIVATE-/dev/zero mappings will satisfy vma_is_anonymous() but not fulfill this invariant, so when asserting this we check vma->vm_file to account for this. We do not update callsites yet, so no functional change intended. Also const-ify vma_is_anonymous() to make it compatible with the const-ified linear_virt_page_index(). VMA userland tests are updated accordingly. Link: https://lore.kernel.org/20260720-b4-scalable-cow-virt-pgoff-v2-2-2d549757a76f@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) Cc: Alistair Popple Cc: Arnd Bergmann Cc: Baolin Wang Cc: Barry Song Cc: Byungchul Park Cc: Chengming Zhou Cc: David Hildenbrand Cc: Dev Jain Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: "Huang, Ying" Cc: Jan Kara Cc: Jann Horn Cc: Joshua Hahn Cc: Kees Cook Cc: Lance Yang Cc: Liam R. Howlett Cc: Matthew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Naoya Horiguchi Cc: Nico Pache Cc: Pedro Falcato Cc: Peter Xu Cc: Rakie Kim Cc: Rik van Riel Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: xu xin Cc: Zi Yan Signed-off-by: Andrew Morton --- include/linux/mm.h | 2 - include/linux/pagemap.h | 42 ++++++++++++++++++++++++++++++ tools/testing/vma/include/dup.h | 25 +++++++++++++++++ 3 files changed, 67 insertions(+), 2 deletions(-) --- a/include/linux/mm.h~mm-introduce-linear_virt_page_index +++ a/include/linux/mm.h @@ -1556,7 +1556,7 @@ static inline void vma_desc_set_anonymou desc->vm_ops = NULL; } -static inline bool vma_is_anonymous(struct vm_area_struct *vma) +static inline bool vma_is_anonymous(const struct vm_area_struct *vma) { return !vma->vm_ops; } --- a/include/linux/pagemap.h~mm-introduce-linear_virt_page_index +++ a/include/linux/pagemap.h @@ -1101,6 +1101,48 @@ static inline pgoff_t linear_page_index( return pgoff; } +static inline pgoff_t __linear_virt_page_index(const struct vm_area_struct *vma, + const unsigned long address) +{ + pgoff_t pgoff; + + pgoff = linear_page_delta(vma, address); + pgoff += vma_start_virt_pgoff(vma); + return pgoff; +} + +/** + * linear_virt_page_index() - Determine the absolute virtual page offset of + * @address within @vma. + * @vma: An anonymous or MAP_PRIVATE file-backed VMA in which @address resides. + * @address: The address whose absolute page offset is required. + * + * This returns the virtual page offset of @address, which is the page offset + * the address possessed at the time the VMA was first faulted. + * + * For anonymous mappings, this returns the same value as linear_page_index(). + * + * For MAP_PRIVATE file-backed mappings, this returns the virtual page offset of + * @address, which is the page offset the address possessed at the time the VMA + * was first faulted. + * + * It is not valid to call this function for shared file-backed mappings. + * + * Returns: The absolute virtual page offset of @address within @vma. + */ +static inline pgoff_t linear_virt_page_index(const struct vm_area_struct *vma, + const unsigned long address) +{ + const pgoff_t pgoff = __linear_virt_page_index(vma, address); + + VM_WARN_ON_ONCE(vma_test(vma, VMA_SHARED_BIT)); + /* Account for MAP_PRIVATE-/dev/zero which is only semi-anonymous. */ + if (vma_is_anonymous(vma) && !vma->vm_file) + VM_WARN_ON_ONCE(pgoff != linear_page_index(vma, address)); + + return pgoff; +} + struct wait_page_key { struct folio *folio; int bit_nr; --- a/tools/testing/vma/include/dup.h~mm-introduce-linear_virt_page_index +++ a/tools/testing/vma/include/dup.h @@ -1417,7 +1417,7 @@ static inline void vma_iter_set(struct v mas_set(&vmi->mas, addr); } -static inline bool vma_is_anonymous(struct vm_area_struct *vma) +static inline bool vma_is_anonymous(const struct vm_area_struct *vma) { return !vma->vm_ops; } @@ -1608,3 +1608,26 @@ static inline pgprot_t vma_get_page_prot { return vma_flags_to_page_prot(vma->flags); } + +static inline pgoff_t __linear_virt_page_index(const struct vm_area_struct *vma, + const unsigned long address) +{ + pgoff_t pgoff; + + pgoff = linear_page_delta(vma, address); + pgoff += vma_start_virt_pgoff(vma); + return pgoff; +} + +static inline pgoff_t linear_virt_page_index(const struct vm_area_struct *vma, + const unsigned long address) +{ + const pgoff_t pgoff = __linear_virt_page_index(vma, address); + + VM_WARN_ON_ONCE(vma_test(vma, VMA_SHARED_BIT)); + /* Account for MAP_PRIVATE-/dev/zero which is only semi-anonymous. */ + if (vma_is_anonymous(vma) && !vma->vm_file) + VM_WARN_ON_ONCE(pgoff != linear_page_index(vma, address)); + + return pgoff; +} _ Patches currently in -mm which might be from ljs@kernel.org are mm-vmalloc-acquire-init_mm-lock-on-huge-vmap-to-avoid-ptdump-uaf.patch x86-mm-pat-acquire-init_mm-write-lock-on-collapse-to-avoid-uaf.patch x86-mm-pat-acquire-init_mm-read-lock-on-attribute-change-to-avoid-uaf.patch mm-ptdump-always-stabilise-against-page-table-freeing-using-init_mm.patch arm64-remove-redundant-concurrent-ptdump-uaf-mitigation.patch mm-move-alloc-tag-to-mm.patch mm-move-vma_start_pgoff-into-mmh-and-clean-up.patch mm-add-kdoc-comments-for-vma_start-last_pgoff.patch tools-testing-vma-use-vma_start_pgoff-in-merge-tests.patch mm-introduce-and-use-vma_end_pgoff.patch mm-rmap-update-mm-interval_treec-comments.patch mm-rmap-parameterise-vma_interval_tree_-by-address_space.patch mm-rmap-elide-unnecessary-static-inlines-in-interval_treec.patch mm-rmap-rename-vma_interval_tree_-to-mapping_rmap_tree_.patch mm-rmap-parameterise-anon_vma_interval_tree_-by-anon_vma.patch mm-rmap-rename-anon_vma_interval_tree_-params-and-use-pgoff_t.patch mm-rmap-rename-anon_vma_interval_tree_-to-anon_rmap_tree_.patch maintainers-move-mm-interval_treec-to-rmap-section.patch mm-vma-introduce-and-use-vmg_pages-vmg__pgoff.patch mm-vma-clean-up-anon_vma_compatible.patch mm-vma-refactor-vmg_adjust_set_range-for-clarity.patch mm-vma-minor-cleanup-of-expand_.patch mm-introduce-and-use-linear_page_delta.patch mm-vma-use-vma_start_pgoff-linear_page_index-in-mm-code.patch mm-prefer-vma__pgoff-to-vma-vm_pgoff-in-kernel.patch mm-vma-remove-duplicative-vma_pgoff_offset-helper.patch mm-use-linear_page_-consistently.patch mm-vma-introduce-vma_assert_can_modify.patch mm-vma-add-and-use-vma__pgoff.patch mm-vma-move-__install_special_mapping-to-vmac.patch mm-vma-make-vma_set_range-static-drop-insert_vm_struct-decl.patch mm-vma-update-vma_shrink-to-not-pass-start-pgoff-parameters.patch mm-vma-update-vmg_adjust_set_range-to-offset-pgoff-instead.patch mm-vma-slightly-rework-the-anonymous-check-in-__mmap_new_vma.patch mm-vma-introduce-and-use-vma_set_pgoff.patch mm-vma-correct-incorrect-vmah-inclusion.patch mm-vma-use-guard-clauses-in-can_vma_merge_.patch tools-testing-vma-default-vma-mm-flag-bits-to-64-bit.patch tools-testing-vma-output-compared-expression-on-assert_.patch mm-introduce-vma_flags_can_grow-and-vma_can_grow.patch mm-vma-update-do_mmap-to-use-vma_flags_t.patch mm-convert-__get_unmapped_area-to-use-vma_flags_t.patch mm-update-generic_get_unmapped_area-to-use-vma_flags_t.patch mm-prefer-mm-def_vma_flags-in-mm-logic.patch mm-vma-convert-vm_pgprot_modify-to-use-vma_flags_t-and-rename.patch mm-vma-rename-vma_get_page_prot-to-vma_flags_to_page_prot.patch mm-introduce-vma_get_page_prot-and-use-it.patch mm-vma-update-create_init_stack_vma-to-use-vma_flags_t.patch mm-vma-convert-miscellaneous-uses-of-vma-flags-in-core-mm.patch mm-mlock-convert-mlock-code-to-use-vma_flags_t.patch mm-mprotect-convert-mprotect-code-to-use-vma_flags_t.patch mm-mremap-convert-mremap-code-to-use-vma_flags_t.patch mm-mseal-remove-superfluous-comments-fix-confusion-around-mm.patch mm-mseal-limit-scope-of-mseal-address-zero-to-address-zero.patch mm-mseal-remove-further-superfluous-comments-do_mseal.patch mm-vma-introduce-vma-virtual-page-offset-field-and-add-helpers.patch mm-introduce-linear_virt_page_index.patch mm-abstract-vma_address-and-introduce-vma_anon_address.patch mm-update-print_bad_page_map-to-show-virtual-page-index.patch mm-introduce-and-use-vma_filebacked_address.patch mm-propagate-vma-virtual-page-offset-on-map-remap-split-merge.patch mm-rmap-track-whether-the-page-vma-mapped-walk-is-anonymous.patch mm-introduce-and-use-linear_folio_page_index.patch mm-rmap-use-virt-pgoff-for-map_private-file-backed-anon-folios.patch tools-testing-vma-expand-vma-merge-tests-to-assert-virt-pgoff.patch tools-testing-selftests-mm-test-virtual-page-offset-merge-behaviour.patch mm-vma-only-permit-map_private-dev-zero-to-be-mapped-anonymous.patch mm-vma-make-map_private-mapped-dev-zero-mappings-truly-anonymous.patch tools-testing-vma-add-test-to-assert-map_private-dev-zero-is-anon.patch tools-testing-selftests-mm-add-map_private-dev-zero-merge-tests.patch