From: Liam Howlett <liam.howlett@xxxxxxxxxx> Subject: mm/ksm: use vma_lookup() in find_mergeable_vma() 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/20210521174745.2219620-19-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/ksm.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/mm/ksm.c~mm-ksm-use-vma_lookup-in-find_mergeable_vma +++ a/mm/ksm.c @@ -521,10 +521,8 @@ static struct vm_area_struct *find_merge struct vm_area_struct *vma; if (ksm_test_exit(mm)) return NULL; - vma = find_vma(mm, addr); - if (!vma || vma->vm_start > addr) - return NULL; - if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma) + vma = vma_lookup(mm, addr); + if (!vma || !(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma) return NULL; return vma; } _
