diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/mm/pgtable_64.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c index 59daa5eeec25..6bfadf1aa5cb 100644 --- a/arch/powerpc/mm/pgtable_64.c +++ b/arch/powerpc/mm/pgtable_64.c @@ -839,6 +839,17 @@ pmd_t pmdp_get_and_clear(struct mm_struct *mm, * hash fault look at them. */ memset(pgtable, 0, PTE_FRAG_SIZE); + /* + * Serialize against find_linux_pte_or_hugepte which does lock-less + * lookup in page tables with local interrupts disabled. For huge pages + * it casts pmd_t to pte_t. Since format of pte_t is different from + * pmd_t we want to prevent transit from pmd pointing to page table + * to pmd pointing to huge page (and back) while interrupts are disabled. + * We clear pmd to possibly replace it with page table pointer in + * different code paths. So make sure we wait for the parallel + * find_linux_pte_or_hugepage to finish. + */ + kick_all_cpus_sync(); return old_pmd; } |