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-rw-r--r--mm/huge_memory.c7
-rw-r--r--mm/memory-failure.c27
2 files changed, 28 insertions, 6 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index e187454..b6c1ce3 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1162,7 +1162,12 @@ static void __split_huge_page_refcount(struct page *page)
/* after clearing PageTail the gup refcount can be released */
smp_mb();
- page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
+ /*
+ * retain hwpoison flag of the poisoned tail page:
+ * fix for the unsuitable process killed on Guest Machine(KVM)
+ * by the memory-failure.
+ */
+ page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP | __PG_HWPOISON;
page_tail->flags |= (page->flags &
((1L << PG_referenced) |
(1L << PG_swapbacked) |
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 1e9c30b..04158d6 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -854,6 +854,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
int ret;
int kill = 1;
struct page *hpage = compound_head(p);
+ struct page *ppage;
if (PageReserved(p) || PageSlab(p))
return SWAP_SUCCESS;
@@ -894,6 +895,14 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
}
}
+ /*
+ * ppage: poisoned page
+ * if p is regular page(4k page)
+ * ppage == real poisoned page;
+ * else p is hugetlb or THP, ppage == head page.
+ */
+ ppage = hpage;
+
if (PageTransHuge(hpage)) {
/*
* Verify that this isn't a hugetlbfs head page, the check for
@@ -919,6 +928,8 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
BUG_ON(!PageHWPoison(p));
return SWAP_FAIL;
}
+ /* THP is split, so ppage should be the real poisoned page. */
+ ppage = p;
}
}
@@ -931,12 +942,18 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* there's nothing that can be done.
*/
if (kill)
- collect_procs(hpage, &tokill);
+ collect_procs(ppage, &tokill);
- ret = try_to_unmap(hpage, ttu);
+ if (hpage != ppage)
+ lock_page_nosync(ppage);
+
+ ret = try_to_unmap(ppage, ttu);
if (ret != SWAP_SUCCESS)
printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
- pfn, page_mapcount(hpage));
+ pfn, page_mapcount(ppage));
+
+ if (hpage != ppage)
+ unlock_page(ppage);
/*
* Now that the dirty bit has been propagated to the
@@ -947,7 +964,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* use a more force-full uncatchable kill to prevent
* any accesses to the poisoned memory.
*/
- kill_procs_ao(&tokill, !!PageDirty(hpage), trapno,
+ kill_procs_ao(&tokill, !!PageDirty(ppage), trapno,
ret != SWAP_SUCCESS, p, pfn);
return ret;
@@ -1090,7 +1107,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags)
* For error on the tail page, we should set PG_hwpoison
* on the head page to show that the hugepage is hwpoisoned
*/
- if (PageTail(p) && TestSetPageHWPoison(hpage)) {
+ if (PageHuge(p) && PageTail(p) && TestSetPageHWPoison(hpage)) {
action_result(pfn, "hugepage already hardware poisoned",
IGNORED);
unlock_page(hpage);
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