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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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2
arch/s390/mm/pageattr.c
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@@ -21,7 +21,7 @@ static void change_page_attr(unsigned long addr, int numpages,
pgdp = pgd_offset(&init_mm, addr);
pudp = pud_offset(pgdp, addr);
pmdp = pmd_offset(pudp, addr);
if (pmd_huge(*pmdp)) {
if (pmd_large(*pmdp)) {
WARN_ON_ONCE(1);
continue;
}