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 long get_random_long(void) 46 { 47 #if BITS_PER_LONG == 64 48 return get_random_u64(); 49 #else 50 return get_random_u32(); 51 #endif 52 } 53 54 /* 55 * On 64-bit architectures, protect against non-terminated C string overflows 56 * by zeroing out the first byte of the canary; this leaves 56 bits of entropy. 57 */ 58 #ifdef CONFIG_64BIT 59 # ifdef __LITTLE_ENDIAN 60 # define CANARY_MASK 0xffffffffffffff00UL 61 # else /* big endian, 64 bits: */ 62 # define CANARY_MASK 0x00ffffffffffffffUL 63 # endif 64 #else /* 32 bits: */ 65 # define CANARY_MASK 0xffffffffUL 66 #endif 67 68 static inline unsigned long get_random_canary(void) 69 { 70 return get_random_long() & CANARY_MASK; 71 } 72 73 void __init random_init_early(const char *command_line); 74 void __init random_init(void); 75 bool rng_is_initialized(void); 76 int wait_for_random_bytes(void); 77 78 /* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes). 79 * Returns the result of the call to wait_for_random_bytes. */ 80 static inline int get_random_bytes_wait(void *buf, size_t nbytes) 81 { 82 int ret = wait_for_random_bytes(); 83 get_random_bytes(buf, nbytes); 84 return ret; 85 } 86 87 #define declare_get_random_var_wait(name, ret_type) \ 88 static inline int get_random_ ## name ## _wait(ret_type *out) { \ 89 int ret = wait_for_random_bytes(); \ 90 if (unlikely(ret)) \ 91 return ret; \ 92 *out = get_random_ ## name(); \ 93 return 0; \ 94 } 95 declare_get_random_var_wait(u8, u8) 96 declare_get_random_var_wait(u16, u16) 97 declare_get_random_var_wait(u32, u32) 98 declare_get_random_var_wait(u64, u32) 99 declare_get_random_var_wait(long, unsigned long) 100 #undef declare_get_random_var 101 102 /* 103 * This is designed to be standalone for just prandom 104 * users, but for now we include it from <linux/random.h> 105 * for legacy reasons. 106 */ 107 #include <linux/prandom.h> 108 109 #include <asm/archrandom.h> 110 111 /* 112 * Called from the boot CPU during startup; not valid to call once 113 * secondary CPUs are up and preemption is possible. 114 */ 115 #ifndef arch_get_random_seed_longs_early 116 static inline size_t __init arch_get_random_seed_longs_early(unsigned long *v, size_t max_longs) 117 { 118 WARN_ON(system_state != SYSTEM_BOOTING); 119 return arch_get_random_seed_longs(v, max_longs); 120 } 121 #endif 122 123 #ifndef arch_get_random_longs_early 124 static inline bool __init arch_get_random_longs_early(unsigned long *v, size_t max_longs) 125 { 126 WARN_ON(system_state != SYSTEM_BOOTING); 127 return arch_get_random_longs(v, max_longs); 128 } 129 #endif 130 131 #ifdef CONFIG_SMP 132 int random_prepare_cpu(unsigned int cpu); 133 int random_online_cpu(unsigned int cpu); 134 #endif 135 136 #ifndef MODULE 137 extern const struct file_operations random_fops, urandom_fops; 138 #endif 139 140 #endif /* _LINUX_RANDOM_H */ 141