1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 #ifndef _LINUX_RANDOM_H 4 #define _LINUX_RANDOM_H 5 6 #include <linux/bug.h> 7 #include <linux/kernel.h> 8 #include <linux/list.h> 9 #include <linux/once.h> 10 11 #include <uapi/linux/random.h> 12 13 struct notifier_block; 14 15 void add_device_randomness(const void *buf, size_t len); 16 void __init add_bootloader_randomness(const void *buf, size_t len); 17 void add_input_randomness(unsigned int type, unsigned int code, 18 unsigned int value) __latent_entropy; 19 void add_interrupt_randomness(int irq) __latent_entropy; 20 void add_hwgenerator_randomness(const void *buf, size_t len, size_t entropy); 21 22 #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) 23 static inline void add_latent_entropy(void) 24 { 25 add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy)); 26 } 27 #else 28 static inline void add_latent_entropy(void) { } 29 #endif 30 31 #if IS_ENABLED(CONFIG_VMGENID) 32 void add_vmfork_randomness(const void *unique_vm_id, size_t len); 33 int register_random_vmfork_notifier(struct notifier_block *nb); 34 int unregister_random_vmfork_notifier(struct notifier_block *nb); 35 #else 36 static inline int register_random_vmfork_notifier(struct notifier_block *nb) { return 0; } 37 static inline int unregister_random_vmfork_notifier(struct notifier_block *nb) { return 0; } 38 #endif 39 40 void get_random_bytes(void *buf, size_t len); 41 u8 get_random_u8(void); 42 u16 get_random_u16(void); 43 u32 get_random_u32(void); 44 u64 get_random_u64(void); 45 static inline unsigned int get_random_int(void) 46 { 47 return get_random_u32(); 48 } 49 static inline unsigned long get_random_long(void) 50 { 51 #if BITS_PER_LONG == 64 52 return get_random_u64(); 53 #else 54 return get_random_u32(); 55 #endif 56 } 57 58 /* 59 * On 64-bit architectures, protect against non-terminated C string overflows 60 * by zeroing out the first byte of the canary; this leaves 56 bits of entropy. 61 */ 62 #ifdef CONFIG_64BIT 63 # ifdef __LITTLE_ENDIAN 64 # define CANARY_MASK 0xffffffffffffff00UL 65 # else /* big endian, 64 bits: */ 66 # define CANARY_MASK 0x00ffffffffffffffUL 67 # endif 68 #else /* 32 bits: */ 69 # define CANARY_MASK 0xffffffffUL 70 #endif 71 72 static inline unsigned long get_random_canary(void) 73 { 74 return get_random_long() & CANARY_MASK; 75 } 76 77 void __init random_init_early(const char *command_line); 78 void __init random_init(void); 79 bool rng_is_initialized(void); 80 int wait_for_random_bytes(void); 81 82 /* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes). 83 * Returns the result of the call to wait_for_random_bytes. */ 84 static inline int get_random_bytes_wait(void *buf, size_t nbytes) 85 { 86 int ret = wait_for_random_bytes(); 87 get_random_bytes(buf, nbytes); 88 return ret; 89 } 90 91 #define declare_get_random_var_wait(name, ret_type) \ 92 static inline int get_random_ ## name ## _wait(ret_type *out) { \ 93 int ret = wait_for_random_bytes(); \ 94 if (unlikely(ret)) \ 95 return ret; \ 96 *out = get_random_ ## name(); \ 97 return 0; \ 98 } 99 declare_get_random_var_wait(u32, u32) 100 declare_get_random_var_wait(u64, u32) 101 declare_get_random_var_wait(int, unsigned int) 102 declare_get_random_var_wait(long, unsigned long) 103 #undef declare_get_random_var 104 105 /* 106 * This is designed to be standalone for just prandom 107 * users, but for now we include it from <linux/random.h> 108 * for legacy reasons. 109 */ 110 #include <linux/prandom.h> 111 112 #include <asm/archrandom.h> 113 114 /* 115 * Called from the boot CPU during startup; not valid to call once 116 * secondary CPUs are up and preemption is possible. 117 */ 118 #ifndef arch_get_random_seed_longs_early 119 static inline size_t __init arch_get_random_seed_longs_early(unsigned long *v, size_t max_longs) 120 { 121 WARN_ON(system_state != SYSTEM_BOOTING); 122 return arch_get_random_seed_longs(v, max_longs); 123 } 124 #endif 125 126 #ifndef arch_get_random_longs_early 127 static inline bool __init arch_get_random_longs_early(unsigned long *v, size_t max_longs) 128 { 129 WARN_ON(system_state != SYSTEM_BOOTING); 130 return arch_get_random_longs(v, max_longs); 131 } 132 #endif 133 134 #ifdef CONFIG_SMP 135 int random_prepare_cpu(unsigned int cpu); 136 int random_online_cpu(unsigned int cpu); 137 #endif 138 139 #ifndef MODULE 140 extern const struct file_operations random_fops, urandom_fops; 141 #endif 142 143 #endif /* _LINUX_RANDOM_H */ 144