From 660b3c3bc8a7e571ff496dad5a94dae599a1c03b Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Mon, 18 Dec 2023 13:58:36 +0000 Subject: [PATCH] mm/memory-failure: check the mapcount of the precise page [ Upstream commit c79c5a0a00a9457718056b588f312baadf44e471 ] A process may map only some of the pages in a folio, and might be missed if it maps the poisoned page but not the head page. Or it might be unnecessarily hit if it maps the head page, but not the poisoned page. Link: https://lkml.kernel.org/r/20231218135837.3310403-3-willy@infradead.org Fixes: 7af446a841a2 ("HWPOISON, hugetlb: enable error handling path for hugepage") Signed-off-by: Matthew Wilcox (Oracle) Cc: Dan Williams Cc: Naoya Horiguchi Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- mm/memory-failure.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index bcd71d8736be..1f23baa98ee9 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1331,7 +1331,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, * This check implies we don't kill processes if their pages * are in the swap cache early. Those are always late kills. */ - if (!page_mapped(hpage)) + if (!page_mapped(p)) return true; if (PageKsm(p)) { @@ -1397,10 +1397,10 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, } } - unmap_success = !page_mapped(hpage); + unmap_success = !page_mapped(p); if (!unmap_success) pr_err("Memory failure: %#lx: failed to unmap page (mapcount=%d)\n", - pfn, page_mapcount(hpage)); + pfn, page_mapcount(p)); /* * try_to_unmap() might put mlocked page in lru cache, so call