tree 64b7488c4046b15c39b6874380cba7207e91e5a1
parent 8d63d99a5dfbdb997d12dd3c07b2070ca723db3b
author Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 1429139595 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1429140917 -0700

mm/migrate: check-before-clear PageSwapCache

With the page flag sanitization patchset, an invalid usage of
ClearPageSwapCache() is detected in migration_page_copy().
migrate_page_copy() is shared by both normal and hugepage (both thp and
hugetlb) code path, so let's check PageSwapCache() and clear it if it's
set to avoid misuse of the invalid clear operation.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>