evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

random: initialize the non-blocking pool via add_hwgenerator_randomness()

Browse source 
commit 3371f3da08cff4b75c1f2dce742d460539d6566d upstream.

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.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Theodore Ts'o 2016-06-12 18:11:51 -04:00 • committed by Greg Kroah-Hartman
parent adc58bfd4d
commit f41fc0bfed
1 changed files with 11 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
drivers/char/random.c
View file

@ -1847,12 +1847,18 @@ void add_hwgenerator_randomness(const char *buffer, size_t count,
{ {
struct entropy_store *poolp = &input_pool; struct entropy_store *poolp = &input_pool;
/* Suspend writing if we're above the trickle threshold. if (unlikely(nonblocking_pool.initialized == 0))
* We'll be woken up again once below random_write_wakeup_thresh, poolp = &nonblocking_pool;
* or when the calling thread is about to terminate. else {
*/ /* Suspend writing if we're above the trickle
wait_event_interruptible(random_write_wait, kthread_should_stop() || * 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); ENTROPY_BITS(&input_pool) <= random_write_wakeup_bits);
}
mix_pool_bytes(poolp, buffer, count); mix_pool_bytes(poolp, buffer, count);
credit_entropy_bits(poolp, entropy); credit_entropy_bits(poolp, entropy);
} }