at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Jane Chu Subject: mm/memory-failure: teach kill_accessing_process to accept hugetlb tail page pfn Date: Mon, 22 Dec 2025 18:21:12 -0700 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]. Furthermore, for [3] to work correctly in the hugetlb repoisoning case, it's essential to inform VM the precise poisoned page, not the head page. Link: https://lkml.kernel.org/r/20251223012113.370674-2-jane.chu@oracle.com Link: https://lkml.kernel.org/r/20231218135837.3310403-1-willy@infradead.org [1] Link: https://lkml.kernel.org/r/20250224211445.2663312-1-jane.chu@oracle.com [2] Link: https://lore.kernel.org/lkml/20251116013223.1557158-1-jiaqiyan@google.com/ [3] Signed-off-by: Jane Chu Reviewed-by: Liam R. Howlett Cc: "David Hildenbrand (Red Hat)" Cc: David Rientjes Cc: Jiaqi Yan Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song 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(-) --- a/mm/memory-failure.c~mm-memory-failure-teach-kill_accessing_process-to-accept-hugetlb-tail-page-pfn +++ a/mm/memory-failure.c @@ -692,6 +692,8 @@ static int check_hwpoisoned_entry(pte_t 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 pfn = softleaf_to_pfn(entry); } - if (!pfn || pfn != poisoned_pfn) + mask = ~((1UL << (shift - PAGE_SHIFT)) - 1); + if (!pfn || ((pfn & mask) != (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; } @@ -2038,10 +2042,8 @@ retry: return 0; case MF_HUGETLB_ALREADY_POISONED: case MF_HUGETLB_ACC_EXISTING_POISON: - if (flags & MF_ACTION_REQUIRED) { - folio = page_folio(p); - res = kill_accessing_process(current, folio_pfn(folio), flags); - } + if (flags & MF_ACTION_REQUIRED) + res = kill_accessing_process(current, pfn, flags); if (res == MF_HUGETLB_ALREADY_POISONED) action_result(pfn, MF_MSG_ALREADY_POISONED, MF_FAILED); else _ Patches currently in -mm which might be from jane.chu@oracle.com are mm-memory-failure-fix-missing-mf_stats-count-in-hugetlb-poison.patch mm-memory-failure-teach-kill_accessing_process-to-accept-hugetlb-tail-page-pfn.patch+ mm-memory-failure-teach-kill_accessing_process-to-accept-hugetlb-tail-page-pfn.patch added to mm-hotfixes-unstable branchAndrew Morton undefinedmm-commits@vger.kernel.org,willy@infradead.org,william.roche@oracle.com,surenb@google.com,stable@vger.kernel.org,rppt@kernel.org,rientjes@google.com,osalvador@suse.de,muchun.song@linux.dev,mhocko@suse.com,lorenzo.stoakes@oracle.com,linmiaohe@huawei.com,Liam.Howlett@oracle.com,jiaqiyan@google.com,david@kernel.org,jane.chu@oracle.com,akpm@linux-foundation.org undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined