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/[email protected]
Signed-off-by: Liam R. Howlett <[email protected]>
Reviewed-by: Laurent Dufour <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Acked-by: Davidlohr Bueso <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 2 insertions, 4 deletions

diff --git a/mm/ksm.c b/mm/ksm.c
index 2f3aaeb34a42..3fa9bc8a67cf 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -521,10 +521,8 @@ static struct vm_area_struct *find_mergeable_vma(struct mm_struct *mm,
 	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;
 }