diff options
| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2022-01-25 21:14:57 +0100 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-02-04 19:22:32 +0100 |
| commit | c321e907aa4803d562d6e70ebed9444ad082f953 (patch) | |
| tree | 716a3613f8cb1540f947a4aece0ae81bb960904a /drivers/char | |
| parent | d2a02e3c8bb6b347818518edff5a4b40ff52d6d8 (diff) | |
random: continually use hwgenerator randomness
The rngd kernel thread may sleep indefinitely if the entropy count is
kept above random_write_wakeup_bits by other entropy sources. To make
best use of multiple sources of randomness, mix entropy from hardware
RNGs into the pool at least once within CRNG_RESEED_INTERVAL.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/random.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 68613f0b6887..3e133d9583a0 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -2205,13 +2205,15 @@ void add_hwgenerator_randomness(const char *buffer, size_t count, return; } - /* Suspend writing if we're above the trickle threshold. + /* Throttle writing if we're above the trickle threshold. * We'll be woken up again once below random_write_wakeup_thresh, - * or when the calling thread is about to terminate. + * when the calling thread is about to terminate, or once + * CRNG_RESEED_INTERVAL has lapsed. */ - wait_event_interruptible(random_write_wait, + wait_event_interruptible_timeout(random_write_wait, !system_wq || kthread_should_stop() || - POOL_ENTROPY_BITS() <= random_write_wakeup_bits); + POOL_ENTROPY_BITS() <= random_write_wakeup_bits, + CRNG_RESEED_INTERVAL); mix_pool_bytes(buffer, count); credit_entropy_bits(entropy); } |