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author | Theodore Ts'o <tytso@mit.edu> | 2016-06-12 18:11:51 -0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2016-06-13 11:15:17 -0400 |
commit | 3371f3da08cff4b75c1f2dce742d460539d6566d (patch) | |
tree | b8a4a011ae96dfe7ad41a83367ffc153bd4ad768 /drivers/char/random.c | |
parent | 1a695a905c18548062509178b98bc91e67510864 (diff) | |
download | linux-stable-3371f3da08cff4b75c1f2dce742d460539d6566d.tar.gz linux-stable-3371f3da08cff4b75c1f2dce742d460539d6566d.tar.bz2 linux-stable-3371f3da08cff4b75c1f2dce742d460539d6566d.zip |
random: initialize the non-blocking pool via add_hwgenerator_randomness()
If we have a hardware RNG and are using the in-kernel rngd, we should
use this to initialize the non-blocking pool so that getrandom(2)
doesn't block unnecessarily.
Cc: stable@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r-- | drivers/char/random.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 0158d3bff7e5..4e2627a8d226 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1849,12 +1849,18 @@ void add_hwgenerator_randomness(const char *buffer, size_t count, { struct entropy_store *poolp = &input_pool; - /* Suspend 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. - */ - wait_event_interruptible(random_write_wait, kthread_should_stop() || + if (unlikely(nonblocking_pool.initialized == 0)) + poolp = &nonblocking_pool; + else { + /* Suspend 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. + */ + wait_event_interruptible(random_write_wait, + kthread_should_stop() || ENTROPY_BITS(&input_pool) <= random_write_wakeup_bits); + } mix_pool_bytes(poolp, buffer, count); credit_entropy_bits(poolp, entropy); } |