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mm, hwpoison, hugetlb: Check hugetlb head page hwpoison flag when unpoison page

PATCH In review luofei 1 participant 2 messages Aug 4, 2022

Subsystems (2)
Memory management HWPoison memory failure handling
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luofei

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#0 lore raw

PATCH 1/1 mm, hwpoison, hugetlb: Check hugetlb head page hwpoison flag when unpoison page

When software-poison a huge page, if dissolve_free_huge_page() failed, the huge page will be added to hugepage_freelists. In this case, the head page will hold the hwpoison flag, but the real poisoned tail page hwpoison flag is not set, this will cause unpoison_memory() fail to unpoison the previously poisoned page.

So add a check on hugetlb head page, and also need to ensure the previously poisoned tail page in huge page raw_hwp_list.

Signed-off-by luofei <[email protected]>
---
 mm/memory-failure.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)
mm/memory-failure.c +23 -1
index 14439806b5ef..fc571b0ceb9d 100644
@@ -2293,6 +2293,28 @@ core_initcall(memory_failure_init);
 		pr_info(fmt, pfn);			\
 })
 
+static bool hugetlb_page_head_poison(struct page *hpage, struct page *page)
+{
+	struct llist_head *head;
+	struct llist_node *t, *tnode;
+	struct raw_hwp_page *p;
+
+	if (PageHuge(page) && PageHWPoison(hpage) && HPageFreed(hpage))
+		return false;
+
+	if (HPageRawHwpUnreliable(hpage))
+		return false;
+
+	head = raw_hwp_list_head(hpage);
+	llist_for_each_safe(tnode, t, head->first) {
+		p = container_of(tnode, struct raw_hwp_page, node);
+		if (p->page == page)
+			return true;
+	}
+
+	return false;
+}
+
 /**
  * unpoison_memory - Unpoison a previously poisoned page
  * @pfn: Page number of the to be unpoisoned page

@@ -2330,7 +2352,7 @@ int unpoison_memory(unsigned long pfn)
 		goto unlock_mutex;
 	}
 
-	if (!PageHWPoison(p)) {
+	if (!PageHWPoison(p) && !hugetlb_page_head_poison(page, p)) {
 		unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
 				 pfn, &unpoison_rs);
 		goto unlock_mutex;
Signature · 1 line
2.27.0
author
#1 lore raw

Sorry, wrong patch, please ignore this email.
________________________________________
发件人: 罗飞
发送时间: 2022年8月4日 19:33:08
收件人: [email protected]; [email protected]
抄送: [email protected]; [email protected]; [email protected]; 罗飞 主题: [PATCH] mm, hwpoison, hugetlb: Check hugetlb head page hwpoison flag when unpoison page

When software-poison a huge page, if dissolve_free_huge_page() failed, the huge page will be added to hugepage_freelists. In this case, the head page will hold the hwpoison flag, but the real poisoned tail page hwpoison flag is not set, this will cause unpoison_memory() fail to unpoison the previously poisoned page.

So add a check on hugetlb head page, and also need to ensure the previously poisoned tail page in huge page raw_hwp_list.

Signed-off-by luofei <[email protected]>
---
 mm/memory-failure.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)
mm/memory-failure.c +23 -1
index 14439806b5ef..fc571b0ceb9d 100644
@@ -2293,6 +2293,28 @@ core_initcall(memory_failure_init);
                pr_info(fmt, pfn);                      \
 })
 
+static bool hugetlb_page_head_poison(struct page *hpage, struct page *page)
+{
+       struct llist_head *head;
+       struct llist_node *t, *tnode;
+       struct raw_hwp_page *p;
+
+       if (PageHuge(page) && PageHWPoison(hpage) && HPageFreed(hpage))
+               return false;
+
+       if (HPageRawHwpUnreliable(hpage))
+               return false;
+
+       head = raw_hwp_list_head(hpage);
+       llist_for_each_safe(tnode, t, head->first) {
+               p = container_of(tnode, struct raw_hwp_page, node);
+               if (p->page == page)
+                       return true;
+       }
+
+       return false;
+}
+
 /**
  * unpoison_memory - Unpoison a previously poisoned page
  * @pfn: Page number of the to be unpoisoned page

@@ -2330,7 +2352,7 @@ int unpoison_memory(unsigned long pfn)
                goto unlock_mutex;
        }
 
-       if (!PageHWPoison(p)) {
+       if (!PageHWPoison(p) && !hugetlb_page_head_poison(page, p)) {
                unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
                                 pfn, &unpoison_rs);
                goto unlock_mutex;

--
2.27.0