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 | u32 get_random_u32(void); |
42 | u64 get_random_u64(void); |
43 | static inline unsigned int get_random_int(void) |
44 | { |
45 | return get_random_u32(); |
46 | } |
47 | static inline unsigned long get_random_long(void) |
48 | { |
49 | #if BITS_PER_LONG == 64 |
50 | return get_random_u64(); |
51 | #else |
52 | return get_random_u32(); |
53 | #endif |
54 | } |
55 | |
56 | /* |
57 | * On 64-bit architectures, protect against non-terminated C string overflows |
58 | * by zeroing out the first byte of the canary; this leaves 56 bits of entropy. |
59 | */ |
60 | #ifdef CONFIG_64BIT |
61 | # ifdef __LITTLE_ENDIAN |
62 | # define CANARY_MASK 0xffffffffffffff00UL |
63 | # else /* big endian, 64 bits: */ |
64 | # define CANARY_MASK 0x00ffffffffffffffUL |
65 | # endif |
66 | #else /* 32 bits: */ |
67 | # define CANARY_MASK 0xffffffffUL |
68 | #endif |
69 | |
70 | static inline unsigned long get_random_canary(void) |
71 | { |
72 | return get_random_long() & CANARY_MASK; |
73 | } |
74 | |
75 | int __init random_init(const char *command_line); |
76 | bool rng_is_initialized(void); |
77 | int wait_for_random_bytes(void); |
78 | |
79 | /* Calls wait_for_random_bytes() and then calls get_random_bytes(buf, nbytes). |
80 | * Returns the result of the call to wait_for_random_bytes. */ |
81 | static inline int get_random_bytes_wait(void *buf, size_t nbytes) |
82 | { |
83 | int ret = wait_for_random_bytes(); |
84 | get_random_bytes(buf, nbytes); |
85 | return ret; |
86 | } |
87 | |
88 | #define declare_get_random_var_wait(name, ret_type) \ |
89 | static inline int get_random_ ## name ## _wait(ret_type *out) { \ |
90 | int ret = wait_for_random_bytes(); \ |
91 | if (unlikely(ret)) \ |
92 | return ret; \ |
93 | *out = get_random_ ## name(); \ |
94 | return 0; \ |
95 | } |
96 | declare_get_random_var_wait(u32, u32) |
97 | declare_get_random_var_wait(u64, u32) |
98 | declare_get_random_var_wait(int, unsigned int) |
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 | |