Commit 53eaa14b authored Nov 30, 2019 by Wei Yang Committed by Linus Torvalds Dec 01, 2019

userfaultfd: remove unnecessary WARN_ON() in __mcopy_atomic_hugetlb()

These 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 these warnings will never be triggered.

Link: http://lkml.kernel.org/r/20190927070032.2129-2-richardw.yang@linux.intel.com


Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 4fb07ee6

mm/userfaultfd.c

+0 −5

Original line number	Diff line number	Diff line
		@@ -242,10 +242,6 @@ retry:
		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.
		*/
		@@ -259,7 +255,6 @@ retry:
		pte_t dst_pteval;

		BUG_ON(dst_addr >= dst_start + len);
		VM_BUG_ON(dst_addr & (vma_hpagesize - 1));

		/*
		* Serialize via hugetlb_fault_mutex

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