From 057a6f2632c956483e2b2628477f0fcd1cd8a844 Mon Sep 17 00:00:00 2001 From: Jane Chu Date: Tue, 20 Jan 2026 16:22:34 -0700 Subject: [PATCH] mm/memory-failure: teach kill_accessing_process to accept hugetlb tail page pfn When a hugetlb folio is being poisoned again, try_memory_failure_hugetlb() passed head pfn to kill_accessing_process(), that is not right. The precise pfn of the poisoned page should be used in order to determine the precise vaddr as the SIGBUS payload. This issue has already been taken care of in the normal path, that is, hwpoison_user_mappings(), see [1][2]. Further more, for [3] to work correctly in the hugetlb repoisoning case, it's essential to inform VM the precise poisoned page, not the head page. [1] https://lkml.kernel.org/r/20231218135837.3310403-1-willy@infradead.org [2] https://lkml.kernel.org/r/20250224211445.2663312-1-jane.chu@oracle.com [3] https://lore.kernel.org/lkml/20251116013223.1557158-1-jiaqiyan@google.com/ Link: https://lkml.kernel.org/r/20260120232234.3462258-2-jane.chu@oracle.com Signed-off-by: Jane Chu Reviewed-by: Liam R. Howlett Acked-by: Miaohe Lin Cc: Chris Mason Cc: David Hildenbrand Cc: David Rientjes Cc: Jiaqi Yan Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naoya Horiguchi Cc: Oscar Salvador Cc: Suren Baghdasaryan Cc: William Roche Cc: Signed-off-by: Andrew Morton --- mm/memory-failure.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 473204359e1f..cf0d526e6d41 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -692,6 +692,8 @@ static int check_hwpoisoned_entry(pte_t pte, unsigned long addr, short shift, unsigned long poisoned_pfn, struct to_kill *tk) { unsigned long pfn = 0; + unsigned long hwpoison_vaddr; + unsigned long mask; if (pte_present(pte)) { pfn = pte_pfn(pte); @@ -702,10 +704,12 @@ static int check_hwpoisoned_entry(pte_t pte, unsigned long addr, short shift, pfn = softleaf_to_pfn(entry); } - if (!pfn || pfn != poisoned_pfn) + mask = ~((1UL << (shift - PAGE_SHIFT)) - 1); + if (!pfn || pfn != (poisoned_pfn & mask)) return 0; - set_to_kill(tk, addr, shift); + hwpoison_vaddr = addr + ((poisoned_pfn - pfn) << PAGE_SHIFT); + set_to_kill(tk, hwpoison_vaddr, shift); return 1; } @@ -2052,10 +2056,8 @@ retry: case MF_HUGETLB_FOLIO_PRE_POISONED: case MF_HUGETLB_PAGE_PRE_POISONED: rv = -EHWPOISON; - if (flags & MF_ACTION_REQUIRED) { - folio = page_folio(p); - rv = kill_accessing_process(current, folio_pfn(folio), flags); - } + if (flags & MF_ACTION_REQUIRED) + rv = kill_accessing_process(current, pfn, flags); if (res == MF_HUGETLB_PAGE_PRE_POISONED) action_result(pfn, MF_MSG_ALREADY_POISONED, MF_FAILED); else -- 2.47.3