The patch titled
Subject: mm/mmap.c: don't unlock VMAs in remap_file_pages()
has been added to the -mm tree. Its filename is
mm-mmap-dont-unlock-vmas-in-remap_file_pages.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-mmap-dont-unlock-vmas-in-remap_file_pages.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-mmap-dont-unlock-vmas-in-remap_file_pages.patch
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------------------------------------------------------
From: Liam Howlett <liam.howlett@xxxxxxxxxx>
Subject: mm/mmap.c: don't unlock VMAs in remap_file_pages()
Since this call uses MAP_FIXED, do_mmap() will munlock the necessary
range. There is also an error in the loop test expression which will
evaluate as false and the loop body has never execute.
Link: https://lkml.kernel.org/r/20210223235010.2296915-1-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 18 +-----------------
1 file changed, 1 insertion(+), 17 deletions(-)
--- a/mm/mmap.c~mm-mmap-dont-unlock-vmas-in-remap_file_pages
+++ a/mm/mmap.c
@@ -3038,25 +3038,9 @@ SYSCALL_DEFINE5(remap_file_pages, unsign
flags &= MAP_NONBLOCK;
flags |= MAP_SHARED | MAP_FIXED | MAP_POPULATE;
- if (vma->vm_flags & VM_LOCKED) {
- struct vm_area_struct *tmp;
+ if (vma->vm_flags & VM_LOCKED)
flags |= MAP_LOCKED;
- /* drop PG_Mlocked flag for over-mapped range */
- for (tmp = vma; tmp->vm_start >= start + size;
- tmp = tmp->vm_next) {
- /*
- * Split pmd and munlock page on the border
- * of the range.
- */
- vma_adjust_trans_huge(tmp, start, start + size, 0);
-
- munlock_vma_pages_range(tmp,
- max(tmp->vm_start, start),
- min(tmp->vm_end, start + size));
- }
- }
-
file = get_file(vma->vm_file);
ret = do_mmap(vma->vm_file, start, size,
prot, flags, pgoff, &populate, NULL);
_
Patches currently in -mm which might be from liam.howlett@xxxxxxxxxx are
mm-mmap-dont-unlock-vmas-in-remap_file_pages.patch
