[PATCH 1/3] fs/userfaultfd.c: remove a redundant check on end

From: Wei Yang
Date: Thu Sep 12 2019 - 17:31:58 EST


For the ending vma, there is a check to make sure the end is huge page
aligned.

The *if* check makes sure vm_start < end <= vm_end. While the first half
is not necessary, because the *for* clause makes sure vm_start < end.

This patch just removes it.

Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
---
fs/userfaultfd.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 653d8f7c453c..9ce09ac619a2 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1402,8 +1402,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
* If this vma contains ending address, and huge pages
* check alignment.
*/
- if (is_vm_hugetlb_page(cur) && end <= cur->vm_end &&
- end > cur->vm_start) {
+ if (is_vm_hugetlb_page(cur) && end <= cur->vm_end) {
unsigned long vma_hpagesize = vma_kernel_pagesize(cur);

ret = -EINVAL;
--
2.17.1