From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: mm: hwpoison_user_mappings() try_to_unmap() with TTU_SYNC TTU_SYNC prevents an unlikely race, when try_to_unmap() returns shortly before the page is accounted as unmapped. It is unlikely to coincide with hwpoisoning, but now that we have the flag, hwpoison_user_mappings() would do well to use it. Link: https://lkml.kernel.org/r/329c28ed-95df-9a2c-8893-b444d8a6d340@xxxxxxxxxx Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> Cc: Alistair Popple <apopple@xxxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: Jue Wang <juew@xxxxxxxxxx> Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxx> Cc: Peter Xu <peterx@xxxxxxxxxx> Cc: Ralph Campbell <rcampbell@xxxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Wang Yugui <wangyugui@xxxxxxxxxxxx> Cc: Yang Shi <shy828301@xxxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory-failure.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory-failure.c~mm-hwpoison_user_mappings-try_to_unmap-with-ttu_sync +++ a/mm/memory-failure.c @@ -1266,7 +1266,7 @@ static int get_hwpoison_page(struct page static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, int flags, struct page **hpagep) { - enum ttu_flags ttu = TTU_IGNORE_MLOCK; + enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC; struct address_space *mapping; LIST_HEAD(tokill); bool unmap_success; _
