diff --git a/crypto/drbg.c b/crypto/drbg.c index 4bb5f93c94cd..7f772c2de45d 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1390,12 +1390,13 @@ static int drbg_generate_long(struct drbg_state *drbg, return 0; } -static void drbg_schedule_async_seed(struct random_ready_callback *rdy) +static int drbg_schedule_async_seed(struct notifier_block *nb, unsigned long action, void *data) { - struct drbg_state *drbg = container_of(rdy, struct drbg_state, + struct drbg_state *drbg = container_of(nb, struct drbg_state, random_ready); schedule_work(&drbg->seed_work); + return 0; } static int drbg_prepare_hrng(struct drbg_state *drbg) @@ -1408,10 +1409,8 @@ static int drbg_prepare_hrng(struct drbg_state *drbg) INIT_WORK(&drbg->seed_work, drbg_async_seed); - drbg->random_ready.owner = THIS_MODULE; - drbg->random_ready.func = drbg_schedule_async_seed; - - err = add_random_ready_callback(&drbg->random_ready); + drbg->random_ready.notifier_call = drbg_schedule_async_seed; + err = register_random_ready_notifier(&drbg->random_ready); switch (err) { case 0: @@ -1422,7 +1421,7 @@ static int drbg_prepare_hrng(struct drbg_state *drbg) /* fall through */ default: - drbg->random_ready.func = NULL; + drbg->random_ready.notifier_call = NULL; return err; } @@ -1528,8 +1527,8 @@ static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers, */ static int drbg_uninstantiate(struct drbg_state *drbg) { - if (drbg->random_ready.func) { - del_random_ready_callback(&drbg->random_ready); + if (drbg->random_ready.notifier_call) { + unregister_random_ready_notifier(&drbg->random_ready); cancel_work_sync(&drbg->seed_work); crypto_free_rng(drbg->jent); drbg->jent = NULL; diff --git a/drivers/char/random.c b/drivers/char/random.c index 753630718c6b..b451bb0255e4 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -84,8 +84,8 @@ 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 = @@ -148,72 +148,45 @@ 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; + return ret; - 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 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); +EXPORT_SYMBOL(register_random_ready_notifier); /* * 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; + int ret; - 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); - - 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); +EXPORT_SYMBOL(unregister_random_ready_notifier); 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) \ diff --git a/include/crypto/drbg.h b/include/crypto/drbg.h index 22f884c97387..53a008b7bfe9 100644 --- a/include/crypto/drbg.h +++ b/include/crypto/drbg.h @@ -136,7 +136,7 @@ struct drbg_state { const struct drbg_state_ops *d_ops; const struct drbg_core *core; struct drbg_string test_data; - struct random_ready_callback random_ready; + struct notifier_block random_ready; }; static inline __u8 drbg_statelen(struct drbg_state *drbg) diff --git a/include/linux/random.h b/include/linux/random.h index 5598f8105eff..b039f7cfa46a 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -10,11 +10,7 @@ #include -struct random_ready_callback { - struct list_head list; - void (*func)(struct random_ready_callback *rdy); - struct module *owner; -}; +struct notifier_block; extern void add_device_randomness(const void *, size_t); extern void add_bootloader_randomness(const void *, size_t); @@ -39,8 +35,8 @@ extern void get_random_bytes(void *buf, size_t nbytes); extern int wait_for_random_bytes(void); extern int __init rand_initialize(void); extern bool rng_is_initialized(void); -extern int add_random_ready_callback(struct random_ready_callback *rdy); -extern void del_random_ready_callback(struct random_ready_callback *rdy); +extern int register_random_ready_notifier(struct notifier_block *nb); +extern int unregister_random_ready_notifier(struct notifier_block *nb); extern size_t __must_check get_random_bytes_arch(void *buf, size_t nbytes); #ifndef MODULE diff --git a/lib/random32.c b/lib/random32.c index 464cad475f54..7e630025cbc3 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -39,6 +39,7 @@ #include #include #include +#include #include /** @@ -545,9 +546,11 @@ static void prandom_reseed(unsigned long dontcare) * To avoid worrying about whether it's safe to delay that interrupt * long enough to seed all CPUs, just schedule an immediate timer event. */ -static void prandom_timer_start(struct random_ready_callback *unused) +static int prandom_timer_start(struct notifier_block *nb, + unsigned long action, void *data) { mod_timer(&seed_timer, jiffies); + return 0; } /* @@ -556,13 +559,13 @@ static void prandom_timer_start(struct random_ready_callback *unused) */ static int __init prandom_init_late(void) { - static struct random_ready_callback random_ready = { - .func = prandom_timer_start + static struct notifier_block random_ready = { + .notifier_call = prandom_timer_start }; - int ret = add_random_ready_callback(&random_ready); + int ret = register_random_ready_notifier(&random_ready); if (ret == -EALREADY) { - prandom_timer_start(&random_ready); + prandom_timer_start(&random_ready, 0, NULL); ret = 0; } return ret;