diff options
| author | Eugene Surovegin <ebs@ebshome.net> | 2006-03-28 10:13:12 -0800 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2006-03-29 13:44:15 +1100 |
| commit | bab70a4af737f623de5b034976a311055308ab86 (patch) | |
| tree | f8c0e9463de01323db2cb1a62f4eb83adb5ce7ca /arch/ppc/mm/pgtable.c | |
| parent | bac30d1a78d0f11c613968fc8b351a91ed465386 (diff) | |
[PATCH] lock PTE before updating it in 440/BookE page fault handler
Fix 44x and BookE page fault handler to correctly lock PTE before
trying to pte_update() it, otherwise this PTE might be swapped out
after pte_present() check but before pte_uptdate() call, resulting in
corrupted PTE. This can happen with enabled preemption and low memory
condition.
Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/ppc/mm/pgtable.c')
| -rw-r--r-- | arch/ppc/mm/pgtable.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/ppc/mm/pgtable.c b/arch/ppc/mm/pgtable.c index a1924876cad..706bca8eb14 100644 --- a/arch/ppc/mm/pgtable.c +++ b/arch/ppc/mm/pgtable.c @@ -368,7 +368,7 @@ void __init io_block_mapping(unsigned long virt, phys_addr_t phys, * the PTE pointer is unmodified if PTE is not found. */ int -get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep) +get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) { pgd_t *pgd; pmd_t *pmd; @@ -383,6 +383,8 @@ get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep) if (pte) { retval = 1; *ptep = pte; + if (pmdp) + *pmdp = pmd; /* XXX caller needs to do pte_unmap, yuck */ } } @@ -420,7 +422,7 @@ unsigned long iopa(unsigned long addr) mm = &init_mm; pa = 0; - if (get_pteptr(mm, addr, &pte)) { + if (get_pteptr(mm, addr, &pte, NULL)) { pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); pte_unmap(pte); } |