From: Jianguo Wu <wujianguo@huawei.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: kirill.shutemov@linux.intel.com,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Mel Gorman <mgorman@suse.de>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
qiuxishi <qiuxishi@huawei.com>, Hanjun Guo <guohanjun@huawei.com>
Subject: [PATCH] mm/hugetlb: check for pte NULL pointer in __page_check_address()
Date: Mon, 16 Dec 2013 17:33:49 +0800 [thread overview]
Message-ID: <52AEC8FD.6050200@huawei.com> (raw)
In __page_check_address(), if address's pud is not present,
huge_pte_offset() will return NULL, we should check the return value.
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
---
mm/rmap.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index 55c8b8d..068522d 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -600,7 +600,11 @@ pte_t *__page_check_address(struct page *page, struct mm_struct *mm,
spinlock_t *ptl;
if (unlikely(PageHuge(page))) {
+ /* when pud is not present, pte will be NULL */
pte = huge_pte_offset(mm, address);
+ if (!pte)
+ return NULL;
+
ptl = huge_pte_lockptr(page_hstate(page), mm, pte);
goto check;
}
--
1.7.1
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next reply other threads:[~2013-12-16 9:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-16 9:33 Jianguo Wu [this message]
2013-12-16 14:25 ` [PATCH] mm/hugetlb: check for pte NULL pointer in __page_check_address() Kirill A. Shutemov
2013-12-17 1:07 ` Jianguo Wu
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