diff options
Diffstat (limited to 'mm/mmu_notifier.c')
| -rw-r--r-- | mm/mmu_notifier.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 96edb33fd09a..eff6b88a993f 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -236,6 +236,37 @@ void __mmu_notifier_invalidate_range(struct mm_struct *mm, } EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range); +/* + * Must be called while holding mm->mmap_sem for either read or write. + * The result is guaranteed to be valid until mm->mmap_sem is dropped. + */ +bool mm_has_blockable_invalidate_notifiers(struct mm_struct *mm) +{ + struct mmu_notifier *mn; + int id; + bool ret = false; + + WARN_ON_ONCE(!rwsem_is_locked(&mm->mmap_sem)); + + if (!mm_has_notifiers(mm)) + return ret; + + id = srcu_read_lock(&srcu); + hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { + if (!mn->ops->invalidate_range && + !mn->ops->invalidate_range_start && + !mn->ops->invalidate_range_end) + continue; + + if (!(mn->ops->flags & MMU_INVALIDATE_DOES_NOT_BLOCK)) { + ret = true; + break; + } + } + srcu_read_unlock(&srcu, id); + return ret; +} + static int do_mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm, int take_mmap_sem) |