diff options
| -rw-r--r-- | drivers/char/hw_random/core.c | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 787ef42a77b9..32a8a867f7f8 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -71,6 +71,7 @@ MODULE_PARM_DESC(default_quality, "default entropy content of hwrng per mill"); static void drop_current_rng(void); +static int hwrng_init(struct hwrng *rng); static void start_khwrngd(void); static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, @@ -103,11 +104,20 @@ static inline void cleanup_rng(struct kref *kref) complete(&rng->cleanup_done); } -static void set_current_rng(struct hwrng *rng) +static int set_current_rng(struct hwrng *rng) { + int err; + BUG_ON(!mutex_is_locked(&rng_mutex)); + + err = hwrng_init(rng); + if (err) + return err; + drop_current_rng(); current_rng = rng; + + return 0; } static void drop_current_rng(void) @@ -149,7 +159,7 @@ static void put_rng(struct hwrng *rng) mutex_unlock(&rng_mutex); } -static inline int hwrng_init(struct hwrng *rng) +static int hwrng_init(struct hwrng *rng) { if (kref_get_unless_zero(&rng->ref)) goto skip_init; @@ -310,15 +320,9 @@ static ssize_t hwrng_attr_current_store(struct device *dev, err = -ENODEV; list_for_each_entry(rng, &rng_list, list) { if (strcmp(rng->name, buf) == 0) { - if (rng == current_rng) { - err = 0; - break; - } - err = hwrng_init(rng); - if (err) - break; - set_current_rng(rng); err = 0; + if (rng != current_rng) + err = set_current_rng(rng); break; } } @@ -481,10 +485,9 @@ int hwrng_register(struct hwrng *rng) old_rng = current_rng; err = 0; if (!old_rng) { - err = hwrng_init(rng); + err = set_current_rng(rng); if (err) goto out_unlock; - set_current_rng(rng); } list_add_tail(&rng->list, &rng_list); @@ -518,8 +521,7 @@ void hwrng_unregister(struct hwrng *rng) tail = list_entry(rng_list.prev, struct hwrng, list); - if (hwrng_init(tail) == 0) - set_current_rng(tail); + set_current_rng(tail); } } |