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>
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 0158d3b..4e2627a 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1849,12 +1849,18 @@
{
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);
}