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s390/mm: fix pmd_huge() usage for kernel mapping

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pmd_huge() will always return 0 on !HUGETLBFS, however we use that helper
function when walking the kernel page tables to decide if we have a
1MB page frame or not.
Since we create 1MB frames for the kernel 1:1 mapping independently of
HUGETLBFS this can lead to incorrect storage accesses since the code
can assume that we have a pointer to a page table instead of a pointer
to a 1MB frame.

Fix this by adding a pmd_large() primitive like other architectures have
it already and remove all references to HUGETLBFS/HUGETLBPAGE from the
code that walks kernel page tables.

Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens
2012-10-01 12:58:34 +02:00
committed by Martin Schwidefsky
parent 521b3d790c
commit 378b1e7a80
3 changed files with 25 additions and 15 deletions
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9
arch/s390/include/asm/pgtable.h
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@@ -507,6 +507,15 @@ static inline int pmd_none(pmd_t pmd)
return (pmd_val(pmd) & _SEGMENT_ENTRY_INV) != 0UL;
}
static inline int pmd_large(pmd_t pmd)
{
#ifdef CONFIG_64BIT
return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
#else
return 0;
#endif
}
static inline int pmd_bad(pmd_t pmd)
{
unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_SEGMENT_ENTRY_INV;