From: Miaohe Lin linmiaohe@huawei.com
commit faeb2ff2c1c5cb60ce0da193580b256c941f99ca upstream.
folio->_mapcount is overloaded in SLAB, so folio_mapped() has to be done after folio_test_slab() is checked. Otherwise slab folio might be treated as a mapped folio leading to false 'Someone maps the hwpoison page' error info.
Link: https://lkml.kernel.org/r/20230727115643.639741-4-linmiaohe@huawei.com Fixes: 230ac719c500 ("mm/hwpoison: don't try to unpoison containment-failed pages") Signed-off-by: Miaohe Lin linmiaohe@huawei.com Reviewed-by: Matthew Wilcox (Oracle) willy@infradead.org Acked-by: Naoya Horiguchi naoya.horiguchi@nec.com Cc: Kefeng Wang wangkefeng.wang@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/memory-failure.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
--- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2502,6 +2502,13 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; }
+ if (folio_test_slab(folio) || PageTable(&folio->page) || folio_test_reserved(folio)) + goto unlock_mutex; + + /* + * Note that folio->_mapcount is overloaded in SLAB, so the simple test + * in folio_mapped() has to be done after folio_test_slab() is checked. + */ if (folio_mapped(folio)) { unpoison_pr_info("Unpoison: Someone maps the hwpoison page %#lx\n", pfn, &unpoison_rs); @@ -2514,9 +2521,6 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; }
- if (folio_test_slab(folio) || PageTable(&folio->page) || folio_test_reserved(folio)) - goto unlock_mutex; - ghp = get_hwpoison_page(p, MF_UNPOISON); if (!ghp) { if (PageHuge(p)) {