path: root/drivers/char/random.c
diff options
authorStephan Mueller <smueller@chronox.de>2015-05-25 15:08:47 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2015-05-27 17:51:53 +0800
commit16b369a91d0dd80be214b7f7801fbc51875454cc (patch)
tree651637281b51655197049065eeba784d3404ac6b /drivers/char/random.c
parent1d9de44e268d880cbe2d0bd3be1ef0661f93fd34 (diff)
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 <andreas.steffen@strongswan.org> CC: Theodore Ts'o <tytso@mit.edu> CC: Sandy Harris <sandyinchina@gmail.com> Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char/random.c')
1 files changed, 12 insertions, 0 deletions
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
@@ -1245,6 +1245,18 @@ void get_random_bytes(void *buf, int nbytes)
+ * 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);
* This function will use the architecture-specific hardware random
* number generator if it is available. The arch-specific hw RNG will
* almost certainly be faster than what we can do in software, but it