[PATCH v6 1/5] random: Blocking API for accessing nonblocking_pool
From: Stephan Mueller <hidden>
Date: 2015-05-13 19:58:03
Also in:
lkml
Subsystem:
random number driver, the rest · Maintainers:
"Theodore Ts'o", Jason A. Donenfeld, Linus Torvalds
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 <redacted> CC: Theodore Ts'o <tytso@mit.edu> CC: Sandy Harris <redacted> Signed-off-by: Stephan Mueller <redacted> --- drivers/char/random.c | 14 ++++++++++++++ include/linux/random.h | 1 + 2 files changed, 15 insertions(+)
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 9cd6968..6f71354 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c@@ -1245,6 +1245,20 @@ 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_interruptible(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 * almost certainly be faster than what we can do in software, but it
diff --git a/include/linux/random.h b/include/linux/random.h
index b05856e..0926d78 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h@@ -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 void 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);
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2.1.0