diff options
Diffstat (limited to 'drivers/char')
-rw-r--r-- | drivers/char/random.c | 67 |
1 files changed, 19 insertions, 48 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index bc2a4f7e3655..aa7bc9a3a864 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -83,8 +83,8 @@ static int crng_init = 0; /* Various types of waiters for crng_init->2 transition. */ static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait); static struct fasync_struct *fasync; -static DEFINE_SPINLOCK(random_ready_list_lock); -static LIST_HEAD(random_ready_list); +static DEFINE_SPINLOCK(random_ready_chain_lock); +static RAW_NOTIFIER_HEAD(random_ready_chain); /* Control how we warn userspace. */ static struct ratelimit_state unseeded_warning = @@ -144,72 +144,43 @@ EXPORT_SYMBOL(wait_for_random_bytes); * * returns: 0 if callback is successfully added * -EALREADY if pool is already initialised (callback not called) - * -ENOENT if module for callback is not alive */ -int add_random_ready_callback(struct random_ready_callback *rdy) +int register_random_ready_notifier(struct notifier_block *nb) { - struct module *owner; unsigned long flags; - int err = -EALREADY; + int ret = -EALREADY; if (crng_ready()) - return err; - - owner = rdy->owner; - if (!try_module_get(owner)) - return -ENOENT; - - spin_lock_irqsave(&random_ready_list_lock, flags); - if (crng_ready()) - goto out; - - owner = NULL; - - list_add(&rdy->list, &random_ready_list); - err = 0; - -out: - spin_unlock_irqrestore(&random_ready_list_lock, flags); - - module_put(owner); + return ret; - return err; + spin_lock_irqsave(&random_ready_chain_lock, flags); + if (!crng_ready()) + ret = raw_notifier_chain_register(&random_ready_chain, nb); + spin_unlock_irqrestore(&random_ready_chain_lock, flags); + return ret; } -EXPORT_SYMBOL(add_random_ready_callback); /* * Delete a previously registered readiness callback function. */ -void del_random_ready_callback(struct random_ready_callback *rdy) +int unregister_random_ready_notifier(struct notifier_block *nb) { unsigned long flags; - struct module *owner = NULL; - - spin_lock_irqsave(&random_ready_list_lock, flags); - if (!list_empty(&rdy->list)) { - list_del_init(&rdy->list); - owner = rdy->owner; - } - spin_unlock_irqrestore(&random_ready_list_lock, flags); + int ret; - module_put(owner); + spin_lock_irqsave(&random_ready_chain_lock, flags); + ret = raw_notifier_chain_unregister(&random_ready_chain, nb); + spin_unlock_irqrestore(&random_ready_chain_lock, flags); + return ret; } -EXPORT_SYMBOL(del_random_ready_callback); static void process_random_ready_list(void) { unsigned long flags; - struct random_ready_callback *rdy, *tmp; - spin_lock_irqsave(&random_ready_list_lock, flags); - list_for_each_entry_safe(rdy, tmp, &random_ready_list, list) { - struct module *owner = rdy->owner; - - list_del_init(&rdy->list); - rdy->func(rdy); - module_put(owner); - } - spin_unlock_irqrestore(&random_ready_list_lock, flags); + spin_lock_irqsave(&random_ready_chain_lock, flags); + raw_notifier_call_chain(&random_ready_chain, 0, NULL); + spin_unlock_irqrestore(&random_ready_chain_lock, flags); } #define warn_unseeded_randomness(previous) \ |