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Date:   Fri, 21 Oct 2022 16:36:46 +0000
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Subject: [RFC PATCH v2 30/47] hugetlb: add high-granularity check for hwpoison
 in fault path
From:   James Houghton <jthoughton@google.com>
To:     Mike Kravetz <mike.kravetz@oracle.com>,
        Muchun Song <songmuchun@bytedance.com>,
        Peter Xu <peterx@redhat.com>
Cc:     David Hildenbrand <david@redhat.com>,
        David Rientjes <rientjes@google.com>,
        Axel Rasmussen <axelrasmussen@google.com>,
        Mina Almasry <almasrymina@google.com>,
        "Zach O'Keefe" <zokeefe@google.com>,
        Manish Mishra <manish.mishra@nutanix.com>,
        Naoya Horiguchi <naoya.horiguchi@nec.com>,
        "Dr . David Alan Gilbert" <dgilbert@redhat.com>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Baolin Wang <baolin.wang@linux.alibaba.com>,
        Miaohe Lin <linmiaohe@huawei.com>,
        Yang Shi <shy828301@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        James Houghton <jthoughton@google.com>
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Precedence: bulk

Because hwpoison swap entries may be placed beneath the hstate-level
PTE, we need to check for it separately (on top of the hstate-level PTE
check that remains).

Signed-off-by: James Houghton <jthoughton@google.com>
---
 mm/hugetlb.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 8dba8d59ebe5..bb0005d57cab 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6154,6 +6154,11 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 		migration_entry_wait_huge(vma, &hpte);
 		return 0;
+	} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) {
+		hugetlb_vma_unlock_read(vma);
+		mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+		return VM_FAULT_HWPOISON_LARGE |
+			VM_FAULT_SET_HINDEX(hstate_index(h));
 	}
 
 	/* PTE markers should be handled the same way as none pte */
-- 
2.38.0.135.g90850a2211-goog