diff options
| -rw-r--r-- | arch/i386/mm/highmem.c | 18 | ||||
| -rw-r--r-- | include/asm-i386/pgtable.h | 7 |
2 files changed, 14 insertions, 11 deletions
diff --git a/arch/i386/mm/highmem.c b/arch/i386/mm/highmem.c index ba44000b906..f9f647cdbc7 100644 --- a/arch/i386/mm/highmem.c +++ b/arch/i386/mm/highmem.c @@ -38,22 +38,19 @@ void *kmap_atomic(struct page *page, enum km_type type) idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); -#ifdef CONFIG_DEBUG_HIGHMEM if (!pte_none(*(kmap_pte-idx))) BUG(); -#endif set_pte(kmap_pte-idx, mk_pte(page, kmap_prot)); - __flush_tlb_one(vaddr); return (void*) vaddr; } void kunmap_atomic(void *kvaddr, enum km_type type) { -#ifdef CONFIG_DEBUG_HIGHMEM unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); +#ifdef CONFIG_DEBUG_HIGHMEM if (vaddr >= PAGE_OFFSET && vaddr < (unsigned long)high_memory) { dec_preempt_count(); preempt_check_resched(); @@ -62,14 +59,14 @@ void kunmap_atomic(void *kvaddr, enum km_type type) if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx)) BUG(); - +#endif /* - * force other mappings to Oops if they'll try to access - * this pte without first remap it + * Force other mappings to Oops if they'll try to access this pte + * without first remap it. Keeping stale mappings around is a bad idea + * also, in case the page changes cacheability attributes or becomes + * a protected page in a hypervisor. */ - pte_clear(&init_mm, vaddr, kmap_pte-idx); - __flush_tlb_one(vaddr); -#endif + kpte_clear_flush(kmap_pte-idx, vaddr); dec_preempt_count(); preempt_check_resched(); @@ -88,7 +85,6 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot)); - __flush_tlb_one(vaddr); return (void*) vaddr; } diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h index 94c87ff4b5a..ee9696d2f67 100644 --- a/include/asm-i386/pgtable.h +++ b/include/asm-i386/pgtable.h @@ -441,6 +441,13 @@ extern pte_t *lookup_address(unsigned long address); #define pte_unmap_nested(pte) do { } while (0) #endif +/* Clear a kernel PTE and flush it from the TLB */ +#define kpte_clear_flush(ptep, vaddr) \ +do { \ + pte_clear(&init_mm, vaddr, ptep); \ + __flush_tlb_one(vaddr); \ +} while (0) + /* * The i386 doesn't have any external MMU info: the kernel page * tables contain all the necessary information. |