[PATCH v2 28/33] mm/vma: slightly rework the anonymous check in __mmap_new_vma()
From: Lorenzo Stoakes <ljs@kernel.org>
Date: 2026-07-10 20:28:20
Also in:
damon, dri-devel, kvm, linux-arm-msm, linux-fsdevel, linux-iommu, linux-mm, linux-perf-users, linux-tegra, lkml, nvdimm
Subsystem:
memory management, memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
Determine if the VMA is anonymous early on, so we separate the logic which invokes callbacks from the rest of the logic. This is in order that a subsequent commit which asserts correct virtual page offset for anonymous mappings correctly asserts this for new anonymous mappings. No functional change intended. Signed-off-by: Lorenzo Stoakes <ljs@kernel.org> --- mm/vma.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/mm/vma.c b/mm/vma.c
index 0699fa07c40f..ec64e179d2f9 100644
--- a/mm/vma.c
+++ b/mm/vma.c@@ -2587,6 +2587,8 @@ static int __mmap_new_file_vma(struct mmap_state *map, static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap, struct mmap_action *action) { + const bool is_anon = !map->file && + !vma_flags_test(&map->vma_flags, VMA_SHARED_BIT); struct vma_iterator *vmi = map->vmi; int error = 0; struct vm_area_struct *vma;
@@ -2601,6 +2603,10 @@ static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap, return -ENOMEM; vma_iter_config(vmi, map->addr, map->end); + + if (is_anon) + vma_set_anonymous(vma); + vma_set_range(vma, map->addr, map->end, map->pgoff); vma->flags = map->vma_flags; vma->vm_page_prot = map->page_prot;
@@ -2610,12 +2616,11 @@ static int __mmap_new_vma(struct mmap_state *map, struct vm_area_struct **vmap, goto free_vma; } + /* Invoke callbacks. */ if (map->file) error = __mmap_new_file_vma(map, vma); - else if (vma_flags_test(&map->vma_flags, VMA_SHARED_BIT)) + else if (!is_anon) error = shmem_zero_setup(vma); - else - vma_set_anonymous(vma); if (error) goto free_iter_vma;
--
2.55.0