mm/mmap: use find_vma_intersection() in do_mmap() for overlap

Using find_vma_intersection() avoids the need for a temporary variable and
makes the code cleaner.

Link: https://lkml.kernel.org/r/20210511014328.2902782-1-Liam.Howlett@Oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
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 d72716f..d8c92ae 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1457,9 +1457,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
                return addr;
 
        if (flags & MAP_FIXED_NOREPLACE) {
-               struct vm_area_struct *vma = find_vma(mm, addr);
-
-               if (vma && vma->vm_start < addr + len)
+               if (find_vma_intersection(mm, addr, addr + len))
                        return -EEXIST;
        }