diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c index d8aebc52265f..649e7d440bd7 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3195,7 +3195,16 @@ static int handle_pte_fault(struct mm_struct *mm, pte_t entry; spinlock_t *ptl; - entry = ACCESS_ONCE(*pte); + /* + * some architectures can have larger ptes than wordsize, + * e.g.ppc44x-defconfig has CONFIG_PTE_64BIT=y and CONFIG_32BIT=y, + * so READ_ONCE or ACCESS_ONCE cannot guarantee atomic accesses. + * The code below just needs a consistent view for the ifs and + * we later double check anyway with the ptl lock held. So here + * a barrier will do. + */ + entry = *pte; + barrier(); if (!pte_present(entry)) { if (pte_none(entry)) { if (vma->vm_ops) { |