diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/mm/memory.c b/mm/memory.c index 75e0abda86427..230bcd12a3362 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5127,18 +5127,18 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf) int flags = 0; /* - * The "pte" at this point cannot be used safely without - * validation through pte_unmap_same(). It's of NUMA type but - * the pfn may be screwed if the read is non atomic. + * The pte cannot be used safely until we verify, while holding the page + * table lock, that its contents have not changed during fault handling. */ spin_lock(vmf->ptl); - if (unlikely(!pte_same(ptep_get(vmf->pte), vmf->orig_pte))) { + /* Read the live PTE from the page tables: */ + old_pte = ptep_get(vmf->pte); + + if (unlikely(!pte_same(old_pte, vmf->orig_pte))) { pte_unmap_unlock(vmf->pte, vmf->ptl); goto out; } - /* Get the normal PTE */ - old_pte = ptep_get(vmf->pte); pte = pte_modify(old_pte, vma->vm_page_prot); /* |