The patch titled
Subject: mm/mmap.c: logic of find_vma_intersection repeated in __do_munmap
has been added to the -mm tree. Its filename is
mm-mmapc-logic-of-find_vma_intersection-repeated-in-__do_munmap.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-mmapc-logic-of-find_vma_intersection-repeated-in-__do_munmap.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-mmapc-logic-of-find_vma_intersection-repeated-in-__do_munmap.patch
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------------------------------------------------------
From: Gonzalo Matias Juarez Tello <gmjuareztello@xxxxxxxxx>
Subject: mm/mmap.c: logic of find_vma_intersection repeated in __do_munmap
Logic of find_vma_intersection() is repeated in __do_munmap().
Also, prev is assigned a value before checking vma->vm_start >= end which
might end up on a return statement making that assignment useless.
Calling find_vma_intersection() checks that condition and returns NULL if
no vma is found, hence only the !vma check is needed in __do_munmap().
Link: https://lkml.kernel.org/r/20210409162129.18313-1-gmjuareztello@xxxxxxxxx
Signed-off-by: Gonzalo Matias Juarez Tello <gmjuareztello@xxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
--- a/mm/mmap.c~mm-mmapc-logic-of-find_vma_intersection-repeated-in-__do_munmap
+++ a/mm/mmap.c
@@ -2828,16 +2828,11 @@ int __do_munmap(struct mm_struct *mm, un
*/
arch_unmap(mm, start, end);
- /* Find the first overlapping VMA */
- vma = find_vma(mm, start);
+ /* Find the first overlapping VMA where start < vma->vm_end */
+ vma = find_vma_intersection(mm, start, end);
if (!vma)
return 0;
prev = vma->vm_prev;
- /* we have start < vma->vm_end */
-
- /* if it doesn't overlap, we have nothing.. */
- if (vma->vm_start >= end)
- return 0;
/*
* If we need to split any vma, do it now to save pain later.
_
Patches currently in -mm which might be from gmjuareztello@xxxxxxxxx are
mm-mmapc-logic-of-find_vma_intersection-repeated-in-__do_munmap.patch
