diff options
| author | Chris Metcalf <[email protected]> | 2012-05-10 13:01:44 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2012-05-10 15:06:44 -0700 |
| commit | 4998a6c0edce7fae9c0a5463f6ec3fa585258ee7 (patch) | |
| tree | d19a02785d8a5793abefb0ec3edb435c77e96a7e | |
| parent | 93278814d3590eba0ee360b8d69a35c7f2203ea8 (diff) | |
hugetlb: prevent BUG_ON in hugetlb_fault() -> hugetlb_cow()
Commit 66aebce747eaf ("hugetlb: fix race condition in hugetlb_fault()")
added code to avoid a race condition by elevating the page refcount in
hugetlb_fault() while calling hugetlb_cow().
However, one code path in hugetlb_cow() includes an assertion that the
page count is 1, whereas it may now also have the value 2 in this path.
The consensus is that this BUG_ON has served its purpose, so rather than
extending it to cover both cases, we just remove it.
Signed-off-by: Chris Metcalf <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Acked-by: Hillf Danton <[email protected]>
Acked-by: Hugh Dickins <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: <[email protected]> [3.0.29+, 3.2.16+, 3.3.3+]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | mm/hugetlb.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5a16423a512c..ae8f708e3d75 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2498,7 +2498,6 @@ retry_avoidcopy: if (outside_reserve) { BUG_ON(huge_pte_none(pte)); if (unmap_ref_private(mm, vma, old_page, address)) { - BUG_ON(page_count(old_page) != 1); BUG_ON(huge_pte_none(pte)); spin_lock(&mm->page_table_lock); ptep = huge_pte_offset(mm, address & huge_page_mask(h)); |