[PATCH 1/2] userfaultfd: remove one unnecessary warn_on in __mcopy_atomic_hugetlb

[Wei Yang <richardw.yang@linux.intel.com>]

The warning here is to make sure address(dst_addr) and length(len -
copied) are huge page size aligned.

While this is ensured by:

    dst_start and len is huge page size aligned
    dst_addr equals to dst_start and increase huge page size each time
    copied increase huge page size each time

This means this warning will never be triggered.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
 mm/userfaultfd.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index c7ae74ce5ff3..7895c715000e 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -243,10 +243,6 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 		vm_shared = dst_vma->vm_flags & VM_SHARED;
 	}
 
-	if (WARN_ON(dst_addr & (vma_hpagesize - 1) ||
-		    (len - copied) & (vma_hpagesize - 1)))
-		goto out_unlock;
-
 	/*
 	 * If not shared, ensure the dst_vma has a anon_vma.
 	 */
-- 
2.17.1