Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | /* |
| 3 | * include/linux/random.h |
| 4 | * |
| 5 | * Include file for the random number generator. |
| 6 | */ |
| 7 | #ifndef _LINUX_RANDOM_H |
| 8 | #define _LINUX_RANDOM_H |
| 9 | |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 10 | #include <linux/bug.h> |
| 11 | #include <linux/kernel.h> |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 12 | #include <linux/list.h> |
| 13 | #include <linux/once.h> |
| 14 | |
| 15 | #include <uapi/linux/random.h> |
| 16 | |
| 17 | struct random_ready_callback { |
| 18 | struct list_head list; |
| 19 | void (*func)(struct random_ready_callback *rdy); |
| 20 | struct module *owner; |
| 21 | }; |
| 22 | |
| 23 | extern void add_device_randomness(const void *, unsigned int); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 24 | extern void add_bootloader_randomness(const void *, unsigned int); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 25 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 26 | #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 27 | static inline void add_latent_entropy(void) |
| 28 | { |
| 29 | add_device_randomness((const void *)&latent_entropy, |
| 30 | sizeof(latent_entropy)); |
| 31 | } |
| 32 | #else |
| 33 | static inline void add_latent_entropy(void) {} |
| 34 | #endif |
| 35 | |
| 36 | extern void add_input_randomness(unsigned int type, unsigned int code, |
| 37 | unsigned int value) __latent_entropy; |
| 38 | extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy; |
| 39 | |
| 40 | extern void get_random_bytes(void *buf, int nbytes); |
| 41 | extern int wait_for_random_bytes(void); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 42 | extern int __init rand_initialize(void); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 43 | extern bool rng_is_initialized(void); |
| 44 | extern int add_random_ready_callback(struct random_ready_callback *rdy); |
| 45 | extern void del_random_ready_callback(struct random_ready_callback *rdy); |
| 46 | extern int __must_check get_random_bytes_arch(void *buf, int nbytes); |
| 47 | |
| 48 | #ifndef MODULE |
| 49 | extern const struct file_operations random_fops, urandom_fops; |
| 50 | #endif |
| 51 | |
| 52 | u32 get_random_u32(void); |
| 53 | u64 get_random_u64(void); |
| 54 | static inline unsigned int get_random_int(void) |
| 55 | { |
| 56 | return get_random_u32(); |
| 57 | } |
| 58 | static inline unsigned long get_random_long(void) |
| 59 | { |
| 60 | #if BITS_PER_LONG == 64 |
| 61 | return get_random_u64(); |
| 62 | #else |
| 63 | return get_random_u32(); |
| 64 | #endif |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * On 64-bit architectures, protect against non-terminated C string overflows |
| 69 | * by zeroing out the first byte of the canary; this leaves 56 bits of entropy. |
| 70 | */ |
| 71 | #ifdef CONFIG_64BIT |
| 72 | # ifdef __LITTLE_ENDIAN |
| 73 | # define CANARY_MASK 0xffffffffffffff00UL |
| 74 | # else /* big endian, 64 bits: */ |
| 75 | # define CANARY_MASK 0x00ffffffffffffffUL |
| 76 | # endif |
| 77 | #else /* 32 bits: */ |
| 78 | # define CANARY_MASK 0xffffffffUL |
| 79 | #endif |
| 80 | |
| 81 | static inline unsigned long get_random_canary(void) |
| 82 | { |
| 83 | unsigned long val = get_random_long(); |
| 84 | |
| 85 | return val & CANARY_MASK; |
| 86 | } |
| 87 | |
| 88 | /* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes). |
| 89 | * Returns the result of the call to wait_for_random_bytes. */ |
| 90 | static inline int get_random_bytes_wait(void *buf, int nbytes) |
| 91 | { |
| 92 | int ret = wait_for_random_bytes(); |
| 93 | get_random_bytes(buf, nbytes); |
| 94 | return ret; |
| 95 | } |
| 96 | |
| 97 | #define declare_get_random_var_wait(var) \ |
| 98 | static inline int get_random_ ## var ## _wait(var *out) { \ |
| 99 | int ret = wait_for_random_bytes(); \ |
| 100 | if (unlikely(ret)) \ |
| 101 | return ret; \ |
| 102 | *out = get_random_ ## var(); \ |
| 103 | return 0; \ |
| 104 | } |
| 105 | declare_get_random_var_wait(u32) |
| 106 | declare_get_random_var_wait(u64) |
| 107 | declare_get_random_var_wait(int) |
| 108 | declare_get_random_var_wait(long) |
| 109 | #undef declare_get_random_var |
| 110 | |
| 111 | unsigned long randomize_page(unsigned long start, unsigned long range); |
| 112 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 113 | /* |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame] | 114 | * This is designed to be standalone for just prandom |
| 115 | * users, but for now we include it from <linux/random.h> |
| 116 | * for legacy reasons. |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 117 | */ |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame] | 118 | #include <linux/prandom.h> |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 119 | |
| 120 | #ifdef CONFIG_ARCH_RANDOM |
| 121 | # include <asm/archrandom.h> |
| 122 | #else |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 123 | static inline bool __must_check arch_get_random_long(unsigned long *v) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 124 | { |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 125 | return false; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 126 | } |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 127 | static inline bool __must_check arch_get_random_int(unsigned int *v) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 128 | { |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 129 | return false; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 130 | } |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 131 | static inline bool __must_check arch_get_random_seed_long(unsigned long *v) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 132 | { |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 133 | return false; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 134 | } |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 135 | static inline bool __must_check arch_get_random_seed_int(unsigned int *v) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 136 | { |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 137 | return false; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 138 | } |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 139 | #endif |
| 140 | |
| 141 | /* |
| 142 | * Called from the boot CPU during startup; not valid to call once |
| 143 | * secondary CPUs are up and preemption is possible. |
| 144 | */ |
| 145 | #ifndef arch_get_random_seed_long_early |
| 146 | static inline bool __init arch_get_random_seed_long_early(unsigned long *v) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 147 | { |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 148 | WARN_ON(system_state != SYSTEM_BOOTING); |
| 149 | return arch_get_random_seed_long(v); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 150 | } |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 151 | #endif |
| 152 | |
| 153 | #ifndef arch_get_random_long_early |
| 154 | static inline bool __init arch_get_random_long_early(unsigned long *v) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 155 | { |
Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 156 | WARN_ON(system_state != SYSTEM_BOOTING); |
| 157 | return arch_get_random_long(v); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 158 | } |
| 159 | #endif |
| 160 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 161 | #endif /* _LINUX_RANDOM_H */ |