linux-stable/include/linux/random.h
Jason A. Donenfeld e052a478a7 random: remove rng_has_arch_random()
With arch randomness being used by every distro and enabled in
defconfigs, the distinction between rng_has_arch_random() and
rng_is_initialized() is now rather small. In fact, the places where they
differ are now places where paranoid users and system builders really
don't want arch randomness to be used, in which case we should respect
that choice, or places where arch randomness is known to be broken, in
which case that choice is all the more important. So this commit just
removes the function and its one user.

Reviewed-by: Petr Mladek <pmladek@suse.com> # for vsprintf.c
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-06-10 11:29:48 +02:00

147 lines
4.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_RANDOM_H
#define _LINUX_RANDOM_H
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/once.h>
#include <uapi/linux/random.h>
struct notifier_block;
void add_device_randomness(const void *buf, size_t len);
void __init add_bootloader_randomness(const void *buf, size_t len);
void add_input_randomness(unsigned int type, unsigned int code,
unsigned int value) __latent_entropy;
void add_interrupt_randomness(int irq) __latent_entropy;
void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy);
#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
static inline void add_latent_entropy(void)
{
add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy));
}
#else
static inline void add_latent_entropy(void) { }
#endif
#if IS_ENABLED(CONFIG_VMGENID)
void add_vmfork_randomness(const void *unique_vm_id, size_t len);
int register_random_vmfork_notifier(struct notifier_block *nb);
int unregister_random_vmfork_notifier(struct notifier_block *nb);
#else
static inline int register_random_vmfork_notifier(struct notifier_block *nb) { return 0; }
static inline int unregister_random_vmfork_notifier(struct notifier_block *nb) { return 0; }
#endif
void get_random_bytes(void *buf, size_t len);
u32 get_random_u32(void);
u64 get_random_u64(void);
static inline unsigned int get_random_int(void)
{
return get_random_u32();
}
static inline unsigned long get_random_long(void)
{
#if BITS_PER_LONG == 64
return get_random_u64();
#else
return get_random_u32();
#endif
}
/*
* On 64-bit architectures, protect against non-terminated C string overflows
* by zeroing out the first byte of the canary; this leaves 56 bits of entropy.
*/
#ifdef CONFIG_64BIT
# ifdef __LITTLE_ENDIAN
# define CANARY_MASK 0xffffffffffffff00UL
# else /* big endian, 64 bits: */
# define CANARY_MASK 0x00ffffffffffffffUL
# endif
#else /* 32 bits: */
# define CANARY_MASK 0xffffffffUL
#endif
static inline unsigned long get_random_canary(void)
{
return get_random_long() & CANARY_MASK;
}
int __init random_init(const char *command_line);
bool rng_is_initialized(void);
int wait_for_random_bytes(void);
/* 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, size_t nbytes)
{
int ret = wait_for_random_bytes();
get_random_bytes(buf, nbytes);
return ret;
}
#define declare_get_random_var_wait(name, ret_type) \
static inline int get_random_ ## name ## _wait(ret_type *out) { \
int ret = wait_for_random_bytes(); \
if (unlikely(ret)) \
return ret; \
*out = get_random_ ## name(); \
return 0; \
}
declare_get_random_var_wait(u32, u32)
declare_get_random_var_wait(u64, u32)
declare_get_random_var_wait(int, unsigned int)
declare_get_random_var_wait(long, unsigned long)
#undef declare_get_random_var
/*
* This is designed to be standalone for just prandom
* users, but for now we include it from <linux/random.h>
* for legacy reasons.
*/
#include <linux/prandom.h>
#ifdef CONFIG_ARCH_RANDOM
# include <asm/archrandom.h>
#else
static inline bool __must_check arch_get_random_long(unsigned long *v) { return false; }
static inline bool __must_check arch_get_random_int(unsigned int *v) { return false; }
static inline bool __must_check arch_get_random_seed_long(unsigned long *v) { return false; }
static inline bool __must_check arch_get_random_seed_int(unsigned int *v) { return false; }
#endif
/*
* Called from the boot CPU during startup; not valid to call once
* secondary CPUs are up and preemption is possible.
*/
#ifndef arch_get_random_seed_long_early
static inline bool __init arch_get_random_seed_long_early(unsigned long *v)
{
WARN_ON(system_state != SYSTEM_BOOTING);
return arch_get_random_seed_long(v);
}
#endif
#ifndef arch_get_random_long_early
static inline bool __init arch_get_random_long_early(unsigned long *v)
{
WARN_ON(system_state != SYSTEM_BOOTING);
return arch_get_random_long(v);
}
#endif
#ifdef CONFIG_SMP
int random_prepare_cpu(unsigned int cpu);
int random_online_cpu(unsigned int cpu);
#endif
#ifndef MODULE
extern const struct file_operations random_fops, urandom_fops;
#endif
#endif /* _LINUX_RANDOM_H */