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author | Andy Whitcroft <apw@shadowen.org> | 2008-06-26 09:55:58 (GMT) |
---|---|---|
committer | Paul Mackerras <paulus@samba.org> | 2008-07-01 01:28:56 (GMT) |
commit | 016b33c4958681c24056abed8ec95844a0da80a3 (patch) | |
tree | 67ba81cb6bc980119fab4eee15f09488e5777012 /include/asm-powerpc/pgtable-ppc32.h | |
parent | 03d70617b8a789c3721afaafde06fcbba7c7ebf1 (diff) | |
download | linux-fsl-qoriq-016b33c4958681c24056abed8ec95844a0da80a3.tar.xz |
powerpc: Add 64 bit version of huge_ptep_set_wrprotect
The implementation of huge_ptep_set_wrprotect() directly calls
ptep_set_wrprotect() to mark a hugepte write protected. However this
call is not appropriate on ppc64 kernels as this is a small page only
implementation. This can lead to the hash not being flushed correctly
when a mapping is being converted to COW, allowing processes to continue
using the original copy.
Currently huge_ptep_set_wrprotect() unconditionally calls
ptep_set_wrprotect(). This is fine on ppc32 kernels as this call is
generic. On 64 bit this is implemented as:
pte_update(mm, addr, ptep, _PAGE_RW, 0);
On ppc64 this last parameter is the page size and is passed directly on
to hpte_need_flush():
hpte_need_flush(mm, addr, ptep, old, huge);
And this directly affects the page size we pass to flush_hash_page():
flush_hash_page(vaddr, rpte, psize, ssize, 0);
As this changes the way the hash is calculated we will flush the wrong
pages, potentially leaving live hashes to the original page.
Move the definition of huge_ptep_set_wrprotect() to the 32/64 bit specific
headers.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'include/asm-powerpc/pgtable-ppc32.h')
-rw-r--r-- | include/asm-powerpc/pgtable-ppc32.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/asm-powerpc/pgtable-ppc32.h b/include/asm-powerpc/pgtable-ppc32.h index dde466b..e1d2bb5 100644 --- a/include/asm-powerpc/pgtable-ppc32.h +++ b/include/asm-powerpc/pgtable-ppc32.h @@ -652,6 +652,12 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, { pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), 0); } +static inline void huge_ptep_set_wrprotect(struct mm_struct *mm, + unsigned long addr, pte_t *ptep) +{ + ptep_set_wrprotect(mm, addr, ptep); +} + #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty) |