[PATCH 35/39] mm: avoid use of VMA_SPECIAL_FLAGS in migrate_vma_setup()
From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
Date: 2026-09-08 20:19:08
Also in:
bpf, dri-devel, fuse-devel, kvm, kvm-riscv, kvmarm, linux-arch, linux-doc, linux-fsdevel, linux-mm, linux-perf-users, linux-rdma, linux-s390, linux-scsi, linux-sound, linux-trace-kernel, linux-usb, linuxppc-dev, lkml, selinux, sparclinux
Subsystem:
memory management, memory management - memory policy and migration, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
Now we have the expressive vma_is_kernel_owned() and vma_is_fixed_mapping() predicates, use them to determine whether to proceed with migration. This drops the VMA_IO_BIT test, which is safe as only kernel-owned mappings may set it. hugetlb mappings remain excluded, as they are fixed mappings. No functional change intended. Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> --- mm/migrate_device.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/mm/migrate_device.c b/mm/migrate_device.c
index b9c453c28795..b74c0ae42768 100644
--- a/mm/migrate_device.c
+++ b/mm/migrate_device.c@@ -739,19 +739,21 @@ static void migrate_vma_unmap(struct migrate_vma *migrate) */ int migrate_vma_setup(struct migrate_vma *args) { + const struct vm_area_struct *vma = args->vma; long nr_pages = (args->end - args->start) >> PAGE_SHIFT; args->start &= PAGE_MASK; args->end &= PAGE_MASK; - if (!args->vma || vma_test_any_mask(args->vma, VMA_SPECIAL_FLAGS) || - vma_is_dax(args->vma)) + if (!vma) + return -EINVAL; + if (vma_is_kernel_owned(vma) || vma_is_fixed_mapping(vma) || + vma_is_dax(vma)) return -EINVAL; if (nr_pages <= 0) return -EINVAL; - if (args->start < args->vma->vm_start || - args->start >= args->vma->vm_end) + if (args->start < vma->vm_start || args->start >= vma->vm_end) return -EINVAL; - if (args->end <= args->vma->vm_start || args->end > args->vma->vm_end) + if (args->end <= vma->vm_start || args->end > vma->vm_end) return -EINVAL; if (!args->src || !args->dst) return -EINVAL;
--
2.55.0