mm/madvise: use vma_lookup() instead of find_vma()

Using vma_lookup() verifies the address is contained in the found vma.
This results in easier to read the code.

Link: https://lkml.kernel.org/r/20230404094515.1883552-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/madvise.c b/mm/madvise.c
index 340125d..405a2c4 100644 (file)
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -852,21 +852,9 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
                *prev = NULL; /* mmap_lock has been dropped, prev is stale */
 
                mmap_read_lock(mm);
-               vma = find_vma(mm, start);
+               vma = vma_lookup(mm, start);
                if (!vma)
                        return -ENOMEM;
-               if (start < vma->vm_start) {
-                       /*
-                        * This "vma" under revalidation is the one
-                        * with the lowest vma->vm_start where start
-                        * is also < vma->vm_end. If start <
-                        * vma->vm_start it means an hole materialized
-                        * in the user address space within the
-                        * virtual range passed to MADV_DONTNEED
-                        * or MADV_FREE.
-                        */
-                       return -ENOMEM;
-               }
                /*
                 * Potential end adjustment for hugetlb vma is OK as
                 * the check below keeps end within vma.