From 16b369a91d0dd80be214b7f7801fbc51875454cc Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Mon, 25 May 2015 15:08:47 +0200 Subject: random: Blocking API for accessing nonblocking_pool The added API calls provide a synchronous function call get_blocking_random_bytes where the caller is blocked until the nonblocking_pool is initialized. CC: Andreas Steffen CC: Theodore Ts'o CC: Sandy Harris Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu --- drivers/char/random.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/char/random.c') diff --git a/drivers/char/random.c b/drivers/char/random.c index 8b8c46b5fd5c..159d0700f7d8 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1244,6 +1244,18 @@ void get_random_bytes(void *buf, int nbytes) } EXPORT_SYMBOL(get_random_bytes); +/* + * Equivalent function to get_random_bytes with the difference that this + * function blocks the request until the nonblocking_pool is initialized. + */ +void get_blocking_random_bytes(void *buf, int nbytes) +{ + if (unlikely(nonblocking_pool.initialized == 0)) + wait_event(urandom_init_wait, nonblocking_pool.initialized); + extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0); +} +EXPORT_SYMBOL(get_blocking_random_bytes); + /* * This function will use the architecture-specific hardware random * number generator if it is available. The arch-specific hw RNG will -- cgit