From e297a783e41560b44e3c14f38e420cba518113b8 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 7 Jun 2017 19:58:56 -0400 Subject: random: add wait_for_random_bytes() API This enables users of get_random_{bytes,u32,u64,int,long} to wait until the pool is ready before using this function, in case they actually want to have reliable randomness. Signed-off-by: Jason A. Donenfeld Signed-off-by: Theodore Ts'o --- include/linux/random.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/random.h b/include/linux/random.h index ed5c3838780d..e29929347c95 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -34,6 +34,7 @@ extern void add_input_randomness(unsigned int type, unsigned int code, extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy; extern void get_random_bytes(void *buf, int nbytes); +extern int wait_for_random_bytes(void); extern int add_random_ready_callback(struct random_ready_callback *rdy); extern void del_random_ready_callback(struct random_ready_callback *rdy); extern void get_random_bytes_arch(void *buf, int nbytes); -- cgit v1.2.3-58-ga151 From da9ba564bd683374b8d319756f312821b8265b06 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 7 Jun 2017 20:05:02 -0400 Subject: random: add get_random_{bytes,u32,u64,int,long,once}_wait family These functions are simple convenience wrappers that call wait_for_random_bytes before calling the respective get_random_* function. Signed-off-by: Jason A. Donenfeld Signed-off-by: Theodore Ts'o --- include/linux/net.h | 2 ++ include/linux/once.h | 2 ++ include/linux/random.h | 25 +++++++++++++++++++++++++ 3 files changed, 29 insertions(+) (limited to 'include') diff --git a/include/linux/net.h b/include/linux/net.h index abcfa46a2bd9..dda2cc939a53 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -274,6 +274,8 @@ do { \ #define net_get_random_once(buf, nbytes) \ get_random_once((buf), (nbytes)) +#define net_get_random_once_wait(buf, nbytes) \ + get_random_once_wait((buf), (nbytes)) int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, size_t num, size_t len); diff --git a/include/linux/once.h b/include/linux/once.h index 285f12cb40e6..9c98aaa87cbc 100644 --- a/include/linux/once.h +++ b/include/linux/once.h @@ -53,5 +53,7 @@ void __do_once_done(bool *done, struct static_key *once_key, #define get_random_once(buf, nbytes) \ DO_ONCE(get_random_bytes, (buf), (nbytes)) +#define get_random_once_wait(buf, nbytes) \ + DO_ONCE(get_random_bytes_wait, (buf), (nbytes)) \ #endif /* _LINUX_ONCE_H */ diff --git a/include/linux/random.h b/include/linux/random.h index e29929347c95..4aecc339558d 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -58,6 +58,31 @@ static inline unsigned long get_random_long(void) #endif } +/* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes). + * Returns the result of the call to wait_for_random_bytes. */ +static inline int get_random_bytes_wait(void *buf, int nbytes) +{ + int ret = wait_for_random_bytes(); + if (unlikely(ret)) + return ret; + get_random_bytes(buf, nbytes); + return 0; +} + +#define declare_get_random_var_wait(var) \ + static inline int get_random_ ## var ## _wait(var *out) { \ + int ret = wait_for_random_bytes(); \ + if (unlikely(ret)) \ + return ret; \ + *out = get_random_ ## var(); \ + return 0; \ + } +declare_get_random_var_wait(u32) +declare_get_random_var_wait(u64) +declare_get_random_var_wait(int) +declare_get_random_var_wait(long) +#undef declare_get_random_var + unsigned long randomize_page(unsigned long start, unsigned long range); u32 prandom_u32(void); -- cgit v1.2.3-58-ga151