diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-06-16 10:17:15 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-06-16 10:17:15 +0200 |
| commit | 28638ea4f8adb63f837e4436560ab16ab0388587 (patch) | |
| tree | 2dab7a03d7696697c82ba62a03700d3a2f3639b1 /mm/memory.c | |
| parent | f781b03c4b1c713ac000877c8bbc31fc4164a29b (diff) | |
| parent | 066519068ad2fbe98c7f45552b1f592903a9c8c8 (diff) | |
Merge branch 'linus' into x86/nmitip-x86-nmi-2008-06-16_09.20_Mon
Conflicts:
arch/x86/kernel/nmi_32.c
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index 48c122d42ed7..19e0ae9beecb 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -311,6 +311,21 @@ int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address) if (!new) return -ENOMEM; + /* + * Ensure all pte setup (eg. pte page lock and page clearing) are + * visible before the pte is made visible to other CPUs by being + * put into page tables. + * + * The other side of the story is the pointer chasing in the page + * table walking code (when walking the page table without locking; + * ie. most of the time). Fortunately, these data accesses consist + * of a chain of data-dependent loads, meaning most CPUs (alpha + * being the notable exception) will already guarantee loads are + * seen in-order. See the alpha page table accessors for the + * smp_read_barrier_depends() barriers in page table walking code. + */ + smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */ + spin_lock(&mm->page_table_lock); if (!pmd_present(*pmd)) { /* Has another populated it ? */ mm->nr_ptes++; @@ -329,6 +344,8 @@ int __pte_alloc_kernel(pmd_t *pmd, unsigned long address) if (!new) return -ENOMEM; + smp_wmb(); /* See comment in __pte_alloc */ + spin_lock(&init_mm.page_table_lock); if (!pmd_present(*pmd)) { /* Has another populated it ? */ pmd_populate_kernel(&init_mm, pmd, new); @@ -2278,8 +2295,6 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, vmf.flags = flags; vmf.page = NULL; - BUG_ON(vma->vm_flags & VM_PFNMAP); - ret = vma->vm_ops->fault(vma, &vmf); if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) return ret; @@ -2619,6 +2634,8 @@ int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) if (!new) return -ENOMEM; + smp_wmb(); /* See comment in __pte_alloc */ + spin_lock(&mm->page_table_lock); if (pgd_present(*pgd)) /* Another has populated it */ pud_free(mm, new); @@ -2640,6 +2657,8 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) if (!new) return -ENOMEM; + smp_wmb(); /* See comment in __pte_alloc */ + spin_lock(&mm->page_table_lock); #ifndef __ARCH_HAS_4LEVEL_HACK if (pud_present(*pud)) /* Another has populated it */ |