From a890d1c657ecba73a7b28591c92587aef1be1888 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 5 Oct 2022 12:54:38 +0200 Subject: [PATCH] random: clear new batches when bringing new CPUs online The commit that added the new get_random_{u8,u16}() functions neglected to update the code that clears the batches when bringing up a new CPU. It also forgot a few comments and helper defines, so add those in too. Fixes: 585cd5fe9f73 ("random: add 8-bit and 16-bit batches") Signed-off-by: Jason A. Donenfeld --- drivers/char/random.c | 28 ++++++++++++++++------------ include/linux/random.h | 2 ++ 2 files changed, 18 insertions(+), 12 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index a007e3dad80f..01acf235f263 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -96,8 +96,8 @@ MODULE_PARM_DESC(ratelimit_disable, "Disable random ratelimit suppression"); /* * Returns whether or not the input pool has been seeded and thus guaranteed * to supply cryptographically secure random numbers. This applies to: the - * /dev/urandom device, the get_random_bytes function, and the get_random_{u32, - * ,u64,int,long} family of functions. + * /dev/urandom device, the get_random_bytes function, and the get_random_{u8, + * u16,u32,u64,int,long} family of functions. * * Returns: true if the input pool has been seeded. * false if the input pool has not been seeded. @@ -119,9 +119,9 @@ static void try_to_generate_entropy(void); /* * Wait for the input pool to be seeded and thus guaranteed to supply * cryptographically secure random numbers. This applies to: the /dev/urandom - * device, the get_random_bytes function, and the get_random_{u32,u64,int,long} - * family of functions. Using any of these functions without first calling - * this function forfeits the guarantee of security. + * device, the get_random_bytes function, and the get_random_{u8,u16,u32,u64, + * int,long} family of functions. Using any of these functions without first + * calling this function forfeits the guarantee of security. * * Returns: 0 if the input pool has been seeded. * -ERESTARTSYS if the function was interrupted by a signal. @@ -157,6 +157,8 @@ EXPORT_SYMBOL(wait_for_random_bytes); * There are a few exported interfaces for use by other drivers: * * void get_random_bytes(void *buf, size_t len) + * u8 get_random_u8() + * u16 get_random_u16() * u32 get_random_u32() * u64 get_random_u64() * unsigned int get_random_int() @@ -164,10 +166,10 @@ EXPORT_SYMBOL(wait_for_random_bytes); * * These interfaces will return the requested number of random bytes * into the given buffer or as a return value. This is equivalent to - * a read from /dev/urandom. The u32, u64, int, and long family of - * functions may be higher performance for one-off random integers, - * because they do a bit of buffering and do not invoke reseeding - * until the buffer is emptied. + * a read from /dev/urandom. The u8, u16, u32, u64, int, and long + * family of functions may be higher performance for one-off random + * integers, because they do a bit of buffering and do not invoke + * reseeding until the buffer is emptied. * *********************************************************************/ @@ -504,10 +506,10 @@ type get_random_ ##type(void) \ } \ EXPORT_SYMBOL(get_random_ ##type); -DEFINE_BATCHED_ENTROPY(u64) -DEFINE_BATCHED_ENTROPY(u32) -DEFINE_BATCHED_ENTROPY(u16) DEFINE_BATCHED_ENTROPY(u8) +DEFINE_BATCHED_ENTROPY(u16) +DEFINE_BATCHED_ENTROPY(u32) +DEFINE_BATCHED_ENTROPY(u64) #ifdef CONFIG_SMP /* @@ -522,6 +524,8 @@ int __cold random_prepare_cpu(unsigned int cpu) * randomness. */ per_cpu_ptr(&crngs, cpu)->generation = ULONG_MAX; + per_cpu_ptr(&batched_entropy_u8, cpu)->position = UINT_MAX; + per_cpu_ptr(&batched_entropy_u16, cpu)->position = UINT_MAX; per_cpu_ptr(&batched_entropy_u32, cpu)->position = UINT_MAX; per_cpu_ptr(&batched_entropy_u64, cpu)->position = UINT_MAX; return 0; diff --git a/include/linux/random.h b/include/linux/random.h index 2c130f8f18e5..08322f700cdc 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -96,6 +96,8 @@ static inline int get_random_bytes_wait(void *buf, size_t nbytes) *out = get_random_ ## name(); \ return 0; \ } +declare_get_random_var_wait(u8, u8) +declare_get_random_var_wait(u16, u16) declare_get_random_var_wait(u32, u32) declare_get_random_var_wait(u64, u32) declare_get_random_var_wait(int, unsigned int) -- 2.34.1