diff options
Diffstat (limited to 'drivers/char/hw_random/core.c')
-rw-r--r-- | drivers/char/hw_random/core.c | 55 |
1 files changed, 25 insertions, 30 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 16f227b995e8..cc002b0c2f0c 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -52,7 +52,7 @@ MODULE_PARM_DESC(default_quality, static void drop_current_rng(void); static int hwrng_init(struct hwrng *rng); -static void hwrng_manage_rngd(struct hwrng *rng); +static int hwrng_fillfn(void *unused); static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, int wait); @@ -96,6 +96,15 @@ static int set_current_rng(struct hwrng *rng) drop_current_rng(); current_rng = rng; + /* if necessary, start hwrng thread */ + if (!hwrng_fill) { + hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng"); + if (IS_ERR(hwrng_fill)) { + pr_err("hwrng_fill thread creation failed\n"); + hwrng_fill = NULL; + } + } + return 0; } @@ -167,8 +176,6 @@ skip_init: rng->quality = 1024; current_quality = rng->quality; /* obsolete */ - hwrng_manage_rngd(rng); - return 0; } @@ -454,10 +461,6 @@ static ssize_t rng_quality_store(struct device *dev, /* the best available RNG may have changed */ ret = enable_best_rng(); - /* start/stop rngd if necessary */ - if (current_rng) - hwrng_manage_rngd(current_rng); - out: mutex_unlock(&rng_mutex); return ret ? ret : len; @@ -507,16 +510,14 @@ static int hwrng_fillfn(void *unused) rng->quality = current_quality; /* obsolete */ quality = rng->quality; mutex_unlock(&reading_mutex); - put_rng(rng); - if (!quality) - break; + if (rc <= 0) + hwrng_msleep(rng, 10000); - if (rc <= 0) { - pr_warn("hwrng: no data available\n"); - msleep_interruptible(10000); + put_rng(rng); + + if (rc <= 0) continue; - } /* If we cannot credit at least one bit of entropy, * keep track of the remainder for the next iteration @@ -533,22 +534,6 @@ static int hwrng_fillfn(void *unused) return 0; } -static void hwrng_manage_rngd(struct hwrng *rng) -{ - if (WARN_ON(!mutex_is_locked(&rng_mutex))) - return; - - if (rng->quality == 0 && hwrng_fill) - kthread_stop(hwrng_fill); - if (rng->quality > 0 && !hwrng_fill) { - hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng"); - if (IS_ERR(hwrng_fill)) { - pr_err("hwrng_fill thread creation failed\n"); - hwrng_fill = NULL; - } - } -} - int hwrng_register(struct hwrng *rng) { int err = -EINVAL; @@ -570,6 +555,7 @@ int hwrng_register(struct hwrng *rng) init_completion(&rng->cleanup_done); complete(&rng->cleanup_done); + init_completion(&rng->dying); if (!current_rng || (!cur_rng_set_by_user && rng->quality > current_rng->quality)) { @@ -617,6 +603,7 @@ void hwrng_unregister(struct hwrng *rng) old_rng = current_rng; list_del(&rng->list); + complete_all(&rng->dying); if (current_rng == rng) { err = enable_best_rng(); if (err) { @@ -685,6 +672,14 @@ void devm_hwrng_unregister(struct device *dev, struct hwrng *rng) } EXPORT_SYMBOL_GPL(devm_hwrng_unregister); +long hwrng_msleep(struct hwrng *rng, unsigned int msecs) +{ + unsigned long timeout = msecs_to_jiffies(msecs) + 1; + + return wait_for_completion_interruptible_timeout(&rng->dying, timeout); +} +EXPORT_SYMBOL_GPL(hwrng_msleep); + static int __init hwrng_modinit(void) { int ret; |