mm/mmap: leave adjust_next as virtual address instead of page frame number
Instead of converting adjust_next between bytes and pages number, let's
just store the virtual address into adjust_next.
Also, this patch fixes one typo in the comment of vma_adjust_trans_huge().
[vbabka@suse.cz: changelog tweak]
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Link: http://lkml.kernel.org/r/20200828081031.11306-1-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mmap.c b/mm/mmap.c
index 0f3ca52..57de816 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -758,7 +758,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
* vma expands, overlapping part of the next:
* mprotect case 5 shifting the boundary up.
*/
- adjust_next = (end - next->vm_start) >> PAGE_SHIFT;
+ adjust_next = (end - next->vm_start);
exporter = next;
importer = vma;
VM_WARN_ON(expand != importer);
@@ -768,7 +768,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
* split_vma inserting another: so it must be
* mprotect case 4 shifting the boundary down.
*/
- adjust_next = -((vma->vm_end - end) >> PAGE_SHIFT);
+ adjust_next = -(vma->vm_end - end);
exporter = vma;
importer = next;
VM_WARN_ON(expand != importer);
@@ -840,8 +840,8 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
}
vma->vm_pgoff = pgoff;
if (adjust_next) {
- next->vm_start += adjust_next << PAGE_SHIFT;
- next->vm_pgoff += adjust_next;
+ next->vm_start += adjust_next;
+ next->vm_pgoff += adjust_next >> PAGE_SHIFT;
}
if (root) {