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From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: linux-mm@kvack.org, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH] mm/memory-failure: fix race with compound page split/merge
Date: Mon, 18 Apr 2016 14:43:45 +0300	[thread overview]
Message-ID: <146097982568.15733.13924990169211134049.stgit@buzz> (raw)

Get_hwpoison_page() must recheck relation between head and tail pages.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
 mm/memory-failure.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 78f5f2641b91..ca5acee53b7a 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -888,7 +888,15 @@ int get_hwpoison_page(struct page *page)
 		}
 	}
 
-	return get_page_unless_zero(head);
+	if (get_page_unless_zero(head)) {
+		if (head == compound_head(page))
+			return 1;
+
+		pr_info("MCE: %#lx cannot catch tail\n", page_to_pfn(page));
+		put_page(head);
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(get_hwpoison_page);
 

WARNING: multiple messages have this Message-ID (diff)
From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: linux-mm@kvack.org, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: linux-kernel@vger.kernel.org,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH] mm/memory-failure: fix race with compound page split/merge
Date: Mon, 18 Apr 2016 14:43:45 +0300	[thread overview]
Message-ID: <146097982568.15733.13924990169211134049.stgit@buzz> (raw)

Get_hwpoison_page() must recheck relation between head and tail pages.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
---
 mm/memory-failure.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 78f5f2641b91..ca5acee53b7a 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -888,7 +888,15 @@ int get_hwpoison_page(struct page *page)
 		}
 	}
 
-	return get_page_unless_zero(head);
+	if (get_page_unless_zero(head)) {
+		if (head == compound_head(page))
+			return 1;
+
+		pr_info("MCE: %#lx cannot catch tail\n", page_to_pfn(page));
+		put_page(head);
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(get_hwpoison_page);
 

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             reply	other threads:[~2016-04-18 11:43 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-18 11:43 Konstantin Khlebnikov [this message]
2016-04-18 11:43 ` [PATCH] mm/memory-failure: fix race with compound page split/merge Konstantin Khlebnikov
2016-04-18 23:15 ` Naoya Horiguchi
2016-04-18 23:15   ` Naoya Horiguchi
2016-04-19  5:54   ` Konstantin Khlebnikov
2016-04-19  5:54     ` Konstantin Khlebnikov
2016-04-21 23:44   ` Andrew Morton
2016-04-21 23:44     ` Andrew Morton

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