From: Miaohe Lin <linmiaohe@xxxxxxxxxx> 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@xxxxxxxxxx Fixes: 230ac719c500 ("mm/hwpoison: don't try to unpoison containment-failed pages") Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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)) {
