[merged mm-stable] mm-vma-add-and-use-vma__pgoff.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The quilt patch titled
     Subject: mm/vma: add and use vma_[add/sub]_pgoff()
has been removed from the -mm tree.  Its filename was
     mm-vma-add-and-use-vma__pgoff.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Lorenzo Stoakes <ljs@kernel.org>
Subject: mm/vma: add and use vma_[add/sub]_pgoff()
Date: Fri, 10 Jul 2026 21:17:04 +0100

Add helpers for adding or subtracting to a VMA's page offset, exposed
internally for VMA users within mm in mm/vma.h.

This is to lay the foundations for tracking anonymous page offset for
MAP_PRIVATE file-backed mappings, where adding and subtracting from this
value must be reflected in both the file and anonymous offsets.

These are used on VMA split and downward stack expansion.

No functional change intended.

[akpm@linux-foundation.org: use linear_page_delta() in __split_vma(), per Vlastimal & Lorenzo]
Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-23-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Ackerley Tng <ackerleytng@google.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Kai Huang <kai.huang@intel.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: SJ Park <sj@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/nommu.c |    6 ++++--
 mm/vma.c   |    6 +++---
 mm/vma.h   |   12 ++++++++++++
 3 files changed, 19 insertions(+), 5 deletions(-)

--- a/mm/nommu.c~mm-vma-add-and-use-vma__pgoff
+++ a/mm/nommu.c
@@ -41,6 +41,7 @@
 #include <asm/tlbflush.h>
 #include <asm/mmu_context.h>
 #include "internal.h"
+#include "vma.h"
 
 unsigned long highest_memmap_pfn;
 int heap_stack_gap = 0;
@@ -1361,7 +1362,8 @@ static int split_vma(struct vma_iterator
 		region->vm_top = region->vm_end = new->vm_end = addr;
 	} else {
 		region->vm_start = new->vm_start = addr;
-		region->vm_pgoff = new->vm_pgoff += npages;
+		vma_add_pgoff(new, npages);
+		region->vm_pgoff = vma_start_pgoff(new);
 	}
 
 	vma_iter_config(vmi, new->vm_start, new->vm_end);
@@ -1378,7 +1380,7 @@ static int split_vma(struct vma_iterator
 	delete_nommu_region(vma->vm_region);
 	if (new_below) {
 		vma->vm_region->vm_start = vma->vm_start = addr;
-		vma->vm_pgoff += npages;
+		vma_add_pgoff(vma, npages);
 		vma->vm_region->vm_pgoff = vma_start_pgoff(vma);
 	} else {
 		vma->vm_region->vm_end = vma->vm_end = addr;
--- a/mm/vma.c~mm-vma-add-and-use-vma__pgoff
+++ a/mm/vma.c
@@ -517,7 +517,7 @@ __split_vma(struct vma_iterator *vmi, st
 		new->vm_end = addr;
 	} else {
 		new->vm_start = addr;
-		new->vm_pgoff += linear_page_delta(vma, addr);
+		vma_add_pgoff(new, linear_page_delta(vma, addr));
 	}
 
 	err = -ENOMEM;
@@ -556,7 +556,7 @@ __split_vma(struct vma_iterator *vmi, st
 
 	if (new_below) {
 		vma->vm_start = addr;
-		vma->vm_pgoff += (addr - new->vm_start) >> PAGE_SHIFT;
+		vma_add_pgoff(vma, linear_page_delta(new, addr));
 	} else {
 		vma->vm_end = addr;
 	}
@@ -3305,7 +3305,7 @@ int expand_downwards(struct vm_area_stru
 				vm_stat_account(mm, vma->vm_flags, grow);
 				anon_rmap_tree_pre_update_vma(vma);
 				vma->vm_start = address;
-				vma->vm_pgoff -= grow;
+				vma_sub_pgoff(vma, grow);
 				/* Overwrite old entry in mtree. */
 				vma_iter_store_overwrite(&vmi, vma);
 				anon_rmap_tree_post_update_vma(vma);
--- a/mm/vma.h~mm-vma-add-and-use-vma__pgoff
+++ a/mm/vma.h
@@ -247,6 +247,18 @@ static inline pgoff_t vmg_end_pgoff(cons
 	return vmg_start_pgoff(vmg) + vmg_pages(vmg);
 }
 
+static inline void vma_add_pgoff(struct vm_area_struct *vma, pgoff_t delta)
+{
+	vma_assert_can_modify(vma);
+	vma->vm_pgoff += delta;
+}
+
+static inline void vma_sub_pgoff(struct vm_area_struct *vma, pgoff_t delta)
+{
+	vma_assert_can_modify(vma);
+	vma->vm_pgoff -= delta;
+}
+
 #define VMG_STATE(name, mm_, vmi_, start_, end_, vma_flags_, pgoff_)	\
 	struct vma_merge_struct name = {				\
 		.mm = mm_,						\
_

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
mm-ptdump-always-stabilise-against-page-table-freeing-using-init_mm.patch
arm64-remove-redundant-concurrent-ptdump-uaf-mitigation.patch
mm-huge_memory-fix-huge_zero_pfn-race.patch
mm-huge_memory-separate-out-config_persistent_huge_zero_folio-logic.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
x86-mm-pat-allocate-split-page-tables-as-kernel-page-tables.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
mm-add-some-missing-includes-to-mm-local-headers.patch