diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 479a1e751a73..8a5ac8c686b0 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -196,28 +196,28 @@ static int do_mmu_notifier_register(struct mmu_notifier *mn, BUG_ON(atomic_read(&mm->mm_users) <= 0); /* - * Verify that mmu_notifier_init() already run and the global srcu is - * initialized. - */ + * Verify that mmu_notifier_init() already run and the global srcu is + * initialized. + */ BUG_ON(!srcu.per_cpu_ref); + ret = -ENOMEM; + mmu_notifier_mm = kmalloc(sizeof(struct mmu_notifier_mm), GFP_KERNEL); + if (unlikely(!mmu_notifier_mm)) + goto out; + if (take_mmap_sem) down_write(&mm->mmap_sem); ret = mm_take_all_locks(mm); if (unlikely(ret)) - goto out; + goto out_clean; if (!mm_has_notifiers(mm)) { - mmu_notifier_mm = kmalloc(sizeof(struct mmu_notifier_mm), - GFP_KERNEL); - if (unlikely(!mmu_notifier_mm)) { - ret = -ENOMEM; - goto out_of_mem; - } INIT_HLIST_HEAD(&mmu_notifier_mm->list); spin_lock_init(&mmu_notifier_mm->lock); mm->mmu_notifier_mm = mmu_notifier_mm; + mmu_notifier_mm = NULL; } atomic_inc(&mm->mm_count); @@ -233,12 +233,12 @@ static int do_mmu_notifier_register(struct mmu_notifier *mn, hlist_add_head(&mn->hlist, &mm->mmu_notifier_mm->list); spin_unlock(&mm->mmu_notifier_mm->lock); -out_of_mem: mm_drop_all_locks(mm); -out: +out_clean: if (take_mmap_sem) up_write(&mm->mmap_sem); - + kfree(mmu_notifier_mm); +out: BUG_ON(atomic_read(&mm->mm_users) <= 0); return ret; }