@@ -168,6 +168,15 @@ enum pageflags {
/* Compound pages. Stored in first tail page's flags */
PG_double_map = PG_workingset,
+#ifdef CONFIG_MEMORY_FAILURE
+ /*
+ * Compound pages. Stored in first tail page's flags.
+ * Indicates that at least one subpage is hwpoisoned in the
+ * THP.
+ */
+ PG_has_hwpoisoned = PG_mappedtodisk,
+#endif
+
/* non-lru isolated movable page */
PG_isolated = PG_reclaim,
@@ -700,6 +709,20 @@ PAGEFLAG_FALSE(DoubleMap)
TESTSCFLAG_FALSE(DoubleMap)
#endif
+#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
+/*
+ * PageHasHWPoisoned indicates that at least one subpage is hwpoisoned in the
+ * compound page.
+ *
+ * This flag is set by hwpoison handler. Cleared by THP split or free page.
+ */
+PAGEFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND)
+ TESTSCFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND)
+#else
+PAGEFLAG_FALSE(HasHWPoisoned)
+ TESTSCFLAG_FALSE(HasHWPoisoned)
+#endif
+
/*
* For pages that are never mapped to userspace (and aren't PageSlab),
* page_type may be used. Because it is initialised to -1, we invert the
@@ -2499,6 +2499,8 @@ static void __split_huge_page(struct page *page, struct list_head *list,
/* lock lru list/PageCompound, ref freezed by page_ref_freeze */
lruvec = lock_page_lruvec(head);
+ ClearPageHasHWPoisoned(head);
+
for (i = nr - 1; i >= 1; i--) {
__split_huge_page_tail(head, i, lruvec, list);
/* Some pages can be beyond i_size: drop them from page cache */
@@ -1474,6 +1474,20 @@ int memory_failure(unsigned long pfn, int flags)
}
if (PageTransHuge(hpage)) {
+ /*
+ * The flag must be set after the refcount is bumped
+ * otherwise it may race with THP split.
+ * And the flag can't be set in get_hwpoison_page() since
+ * it is called by soft offline too and it is just called
+ * for !MF_COUNT_INCREASE. So here seems to be the best
+ * place.
+ *
+ * Don't need care about the above error handling paths for
+ * get_hwpoison_page() since they handle either free page
+ * or unhandlable page. The refcount is bumped iff the
+ * page is a valid handlable page.
+ */
+ SetPageHasHWPoisoned(hpage);
if (try_to_split_thp_page(p, "Memory Failure") < 0) {
action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED);
res = -EBUSY;
@@ -3784,6 +3784,15 @@ static vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
if (compound_order(page) != HPAGE_PMD_ORDER)
return ret;
+ /*
+ * Just backoff if any subpage of a THP is corrupted otherwise
+ * the corrupted page may mapped by PMD silently to escape the
+ * check. This kind of THP just can be PTE mapped. Access to
+ * the corrupted subpage should trigger SIGBUS as expected.
+ */
+ if (unlikely(PageHasHWPoisoned(page)))
+ return ret;
+
/*
* Archs like ppc64 need additonal space to store information
* related to pte entry. Use the preallocated table for that.
@@ -1236,8 +1236,10 @@ static __always_inline bool free_pages_prepare(struct page *page,
VM_BUG_ON_PAGE(compound && compound_order(page) != order, page);
- if (compound)
+ if (compound) {
ClearPageDoubleMap(page);
+ ClearPageHasHWPoisoned(page);
+ }
for (i = 1; i < (1 << order); i++) {
if (compound)
bad += free_tail_pages_check(page, page + i);