+ mm-memory-failure-avoid-false-hwpoison-page-mapped-error-info.patch added to mm-hotfixes-unstable branch

+ mm-memory-failure-avoid-false-hwpoison-page-mapped-error-info.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: memory-failure: avoid false hwpoison page mapped error info
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-memory-failure-avoid-false-hwpoison-page-mapped-error-info.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory-failure-avoid-false-hwpoison-page-mapped-error-info.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm: memory-failure: avoid false hwpoison page mapped error info
Date: Thu, 27 Jul 2023 19:56:42 +0800

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>
---

 mm/memory-failure.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/mm/memory-failure.c~mm-memory-failure-avoid-false-hwpoison-page-mapped-error-info
+++ a/mm/memory-failure.c
@@ -2499,6 +2499,13 @@ 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);
@@ -2511,9 +2518,6 @@ 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)) {
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-swapfile-fix-wrong-swap-entry-type-for-hwpoisoned-swapcache-page.patch
mm-memory-failure-fix-potential-unexpected-return-value-from-unpoison_memory.patch
mm-memory-failure-avoid-false-hwpoison-page-mapped-error-info.patch
mm-memory-failure-add-pageoffline-check.patch
mm-mm_initc-update-obsolete-comment-in-get_pfn_range_for_nid.patch
mm-memory-failure-fix-unexpected-return-value-in-soft_offline_page.patch
mm-memory-failure-fix-potential-page-refcnt-leak-in-memory_failure.patch
mm-memory-failure-remove-unneeded-page-state-check-in-shake_page.patch
memory-tier-use-helper-function-destroy_memory_type.patch
mm-memory-failure-remove-unneeded-inline-annotation.patch
mm-mm_initc-remove-obsolete-macro-hash_small.patch
mm-page_alloc-avoid-false-page-outside-zone-error-info.patch
memory-tier-rename-destroy_memory_type-to-put_memory_type.patch
mm-remove-obsolete-comment-above-struct-per_cpu_pages.patch
mm-memcg-minor-cleanup-for-mem_cgroup_id_max.patch
mm-memory-failure-remove-unneeded-pagehuge-check.patch
mm-memory-failure-ensure-moving-hwpoison-flag-to-the-raw-error-pages.patch
mm-memory-failure-dont-account-hwpoison_filter-filtered-pages.patch
mm-memory-failure-use-local-variable-huge-to-check-hugetlb-page.patch
mm-memory-failure-remove-unneeded-header-files.patch
mm-memory-failure-minor-cleanup-for-comments-and-codestyle.patch
mm-memory-failure-fetch-compound-head-after-extra-page-refcnt-is-held.patch
mm-memory-failure-fix-race-window-when-trying-to-get-hugetlb-folio.patch
mm-huge_memory-use-rmap_none-when-calling-page_add_anon_rmap.patch
mm-memcg-fix-obsolete-comment-above-mem_cgroup_max_reclaim_loops.patch
mm-memcg-minor-cleanup-for-mc_handle_present_pte.patch
memory-tier-use-helper-macro-__attr_rw.patch
mm-fix-obsolete-function-name-above-debug_pagealloc_enabled_static.patch
mm-mprotect-fix-obsolete-function-name-in-change_pte_range.patch
mm-memcg-fix-obsolete-function-name-in-mem_cgroup_protection.patch