From: Liam Howlett <liam.howlett@xxxxxxxxxx> Subject: mm/memory.c: use vma_lookup() in __access_remote_vm() Use vma_lookup() to find the VMA at a specific address. As vma_lookup() will return NULL if the address is not within any VMA, the start address no longer needs to be validated. Link: https://lkml.kernel.org/r/20210521174745.2219620-22-Liam.Howlett@xxxxxxxxxx Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Reviewed-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Acked-by: Davidlohr Bueso <dbueso@xxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/memory.c~mm-memoryc-use-vma_lookup-in-__access_remote_vm +++ a/mm/memory.c @@ -4994,8 +4994,8 @@ int __access_remote_vm(struct mm_struct * Check if this is a VM_IO | VM_PFNMAP VMA, which * we can access using slightly different code. */ - vma = find_vma(mm, addr); - if (!vma || vma->vm_start > addr) + vma = vma_lookup(mm, addr); + if (!vma) break; if (vma->vm_ops && vma->vm_ops->access) ret = vma->vm_ops->access(vma, addr, buf, _
