+ mm-introduce-linear_virt_page_index.patch added to mm-new branch
Andrew Morton <[email protected]>
| Newsgroups | org.kernel.vger.mm-commits |
|---|---|
| Message-ID | <[email protected]> |
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
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------------------------------------------------------
From: "Lorenzo Stoakes (ARM)" <[email protected]>
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/[email protected]
Signed-off-by: Lorenzo Stoakes (ARM) <[email protected]>
Cc: Alistair Popple <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Baolin Wang <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Byungchul Park <[email protected]>
Cc: Chengming Zhou <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Dev Jain <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Gregory Price <[email protected]>
Cc: Harry Yoo <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Joshua Hahn <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Matthew Brost <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Nico Pache <[email protected]>
Cc: Pedro Falcato <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Rakie Kim <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: xu xin <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
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 [email protected] 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