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| author | David Miller <davem@davemloft.net> | 2013-10-02 14:25:09 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-13 18:14:30 -0700 |
| commit | b8a118efef12f11e6f726d46b9d918200d59e479 (patch) | |
| tree | 3d41c27b93380770f548b7a1a3bece1e1f4e5900 | |
| parent | 8e810c7aabe8a9c7451a7ef2fd2fe09ad6fafae5 (diff) | |
| download | lwn-b8a118efef12f11e6f726d46b9d918200d59e479.tar.gz lwn-b8a118efef12f11e6f726d46b9d918200d59e479.zip | |
mm: Fix generic hugetlb pte check return type.
[ Upstream commit 26794942461f438a6bc725ec7294b08a6bd782c4 ]
The include/asm-generic/hugetlb.h stubs that just vector huge_pte_*()
calls to the pte_*() implementations won't work in certain situations.
x86 and sparc, for example, return "unsigned long" from the bit
checks, and just go "return pte_val(pte) & PTE_BIT_FOO;"
But since huge_pte_*() returns 'int', if any high bits on 64-bit are
relevant, they get chopped off.
The net effect is that we can loop forever trying to COW a huge page,
because the huge_pte_write() check signals false all the time.
Reported-by: Gurudas Pai <gurudas.pai@oracle.com>
Tested-by: Gurudas Pai <gurudas.pai@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/asm-generic/hugetlb.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h index d06079c774a0..99b490b4d05a 100644 --- a/include/asm-generic/hugetlb.h +++ b/include/asm-generic/hugetlb.h @@ -6,12 +6,12 @@ static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot) return mk_pte(page, pgprot); } -static inline int huge_pte_write(pte_t pte) +static inline unsigned long huge_pte_write(pte_t pte) { return pte_write(pte); } -static inline int huge_pte_dirty(pte_t pte) +static inline unsigned long huge_pte_dirty(pte_t pte) { return pte_dirty(pte); } |