remap_file_pages: Use vma_lookup() instead of find_vma()

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

Link: https://lkml.kernel.org/r/20210817135234.1550204-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/mmap.c b/mm/mmap.c
index 79f4f8a..52fed23 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2994,14 +2994,11 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
        if (mmap_write_lock_killable(mm))
                return -EINTR;
 
-       vma = find_vma(mm, start);
+       vma = vma_lookup(mm, start);
 
        if (!vma || !(vma->vm_flags & VM_SHARED))
                goto out;
 
-       if (start < vma->vm_start)
-               goto out;
-
        if (start + size > vma->vm_end) {
                struct vm_area_struct *next;