This is a note to let you know that I've just added the patch titled random: initialize the non-blocking pool via add_hwgenerator_randomness() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: random-initialize-the-non-blocking-pool-via-add_hwgenerator_randomness.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 3371f3da08cff4b75c1f2dce742d460539d6566d Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso@xxxxxxx> Date: Sun, 12 Jun 2016 18:11:51 -0400 Subject: random: initialize the non-blocking pool via add_hwgenerator_randomness() From: Theodore Ts'o <tytso@xxxxxxx> 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@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/char/random.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1849,12 +1849,18 @@ void add_hwgenerator_randomness(const ch { 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); } Patches currently in stable-queue which might be from tytso@xxxxxxx are queue-4.4/random-print-a-warning-for-the-first-ten-uninitialized-random-users.patch queue-4.4/random-properly-align-get_random_int_hash.patch queue-4.4/random-initialize-the-non-blocking-pool-via-add_hwgenerator_randomness.patch queue-4.4/random-add-interrupt-callback-to-vmbus-irq-handler.patch queue-4.4/jbd2-make-journal-y2038-safe.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html