From: Liam Howlett <liam.howlett@oracle.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Hugh Dickins <hughd@google.com>,
Liam Howlett <liam.howlett@oracle.com>
Subject: [PATCH v3] mm/mmap: Don't unlock VMAs in remap_file_pages()
Date: Tue, 23 Feb 2021 23:50:23 +0000 [thread overview]
Message-ID: <20210223235010.2296915-1-Liam.Howlett@Oracle.com> (raw)
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.
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Hugh Dickins <hughd@google.com>
---
mm/mmap.c | 18 +-----------------
1 file changed, 1 insertion(+), 17 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index dc7206032387c..e22b048733269 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3025,25 +3025,9 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
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);
--
2.30.0
next reply other threads:[~2021-02-23 23:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 23:50 Liam Howlett [this message]
2021-02-24 2:49 ` [PATCH v3] mm/mmap: Don't unlock VMAs in remap_file_pages() Matthew Wilcox
2021-02-24 10:13 ` David Hildenbrand
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