@@ -1245,6 +1245,26 @@ 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.
+ */
+int get_blocking_random_bytes(void *buf, int nbytes)
+{
+ int rc = 0;
+
+ if (unlikely(nonblocking_pool.initialized == 0))
+ rc = wait_event_interruptible(urandom_init_wait,
+ nonblocking_pool.initialized);
+ if (rc)
+ return rc;
+
+ extract_entropy(&nonblocking_pool, buf, nbytes, 0, 0);
+
+ return 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
* almost certainly be faster than what we can do in software, but it
@@ -14,6 +14,7 @@ extern void add_input_randomness(unsigned int type, unsigned int code,
extern void add_interrupt_randomness(int irq, int irq_flags);
extern void get_random_bytes(void *buf, int nbytes);
+extern int get_blocking_random_bytes(void *buf, int nbytes);
extern void get_random_bytes_arch(void *buf, int nbytes);
void generate_random_uuid(unsigned char uuid_out[16]);
extern int random_int_secret_init(void);
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> --- drivers/char/random.c | 20 ++++++++++++++++++++ include/linux/random.h | 1 + 2 files changed, 21 insertions(+)