@@ -69,8 +69,10 @@ static void add_early_randomness(struct hwrng *rng)
mutex_lock(&reading_mutex);
bytes_read = rng_get_data(rng, rng_fillbuf, 32, 0);
mutex_unlock(&reading_mutex);
- if (bytes_read > 0)
- add_device_randomness(rng_fillbuf, bytes_read);
+ if (bytes_read > 0) {
+ size_t entropy = bytes_read * 8 * rng->quality / 1024;
+ add_hwgenerator_randomness(rng_fillbuf, bytes_read, entropy);
+ }
}
static inline void cleanup_rng(struct kref *kref)
@@ -499,6 +501,7 @@ static int hwrng_fillfn(void *unused)
while (!kthread_should_stop()) {
unsigned short quality;
struct hwrng *rng;
+ unsigned long sleep;
rng = get_current_rng();
if (IS_ERR(rng) || !rng)
@@ -527,8 +530,10 @@ static int hwrng_fillfn(void *unused)
entropy_credit = entropy;
/* Outside lock, sure, but y'know: randomness. */
- add_hwgenerator_randomness((void *)rng_fillbuf, rc,
- entropy >> 10);
+ sleep = add_hwgenerator_randomness((void *)rng_fillbuf, rc,
+ entropy >> 10);
+ if (sleep)
+ hwrng_msleep(rng, jiffies_to_msecs(sleep));
}
hwrng_fill = NULL;
return 0;
@@ -893,9 +893,9 @@ EXPORT_SYMBOL(add_device_randomness);
/*
* Interface for in-kernel drivers of true hardware RNGs.
* Those devices may produce endless random bits and will be throttled
- * when our pool is full.
+ * when our pool is full. Returns suggested sleep time in jiffies.
*/
-void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy)
+unsigned long add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy)
{
mix_pool_bytes(buf, len);
credit_init_bits(entropy);
@@ -904,8 +904,9 @@ void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy)
* Throttle writing to once every reseed interval, unless we're not yet
* initialized or no entropy is credited.
*/
- if (!kthread_should_stop() && (crng_ready() || !entropy))
- schedule_timeout_interruptible(crng_reseed_interval());
+ if (crng_ready() || !entropy)
+ return crng_reseed_interval();
+ return 0;
}
EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
@@ -17,7 +17,7 @@ void __init add_bootloader_randomness(const void *buf, size_t len);
void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value) __latent_entropy;
void add_interrupt_randomness(int irq) __latent_entropy;
-void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy);
+unsigned long add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy);
#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
static inline void add_latent_entropy(void)
Rather than calling add_device_randomness(), the add_early_randomness() function should use add_hwgenerator_randomness(), so that the early entropy can be potentially credited, which allows for the RNG to initialize earlier without having to wait for the kthread to come up. Since we don't want to sleep from add_early_randomness(), we also refactor the API a bit so that hw_random/core.c can do the sleep, this time using the correct function, hwrng_msleep, rather than having random.c awkwardly do it. Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> --- drivers/char/hw_random/core.c | 13 +++++++++---- drivers/char/random.c | 9 +++++---- include/linux/random.h | 2 +- 3 files changed, 15 insertions(+), 9 deletions(-)