Commit 4dc59be5 authored by David Miller's avatar David Miller Committed by Greg Kroah-Hartman

mm: Fix generic hugetlb pte check return type.

[ Upstream commit 26794942 ]

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: default avatarGurudas Pai <gurudas.pai@oracle.com>
Tested-by: default avatarGurudas Pai <gurudas.pai@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 04e7d3c0
......@@ -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);
}
......
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