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authorAkinobu Mita <akinobu.mita@gmail.com>2012-12-17 19:04:23 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-17 20:15:26 -0500
commit496f2f93b1cc286f5a4f4f9acdc1e5314978683f (patch)
tree464fa6bd115ad4e3bedc02a0b0796a9f9e055ccc /lib/random32.c
parent31279b1457f992f24eee8d45ddd647f5fce42cf6 (diff)
random32: rename random32 to prandom
This renames all random32 functions to have 'prandom_' prefix as follows: void prandom_seed(u32 seed); /* rename from srandom32() */ u32 prandom_u32(void); /* rename from random32() */ void prandom_seed_state(struct rnd_state *state, u64 seed); /* rename from prandom32_seed() */ u32 prandom_u32_state(struct rnd_state *state); /* rename from prandom32() */ The purpose of this renaming is to prevent some kernel developers from assuming that prandom32() and random32() might imply that only prandom32() was the one using a pseudo-random number generator by prandom32's "p", and the result may be a very embarassing security exposure. This concern was expressed by Theodore Ts'o. And furthermore, I'm going to introduce new functions for getting the requested number of pseudo-random bytes. If I continue to use both prandom32 and random32 prefixes for these functions, the confusion is getting worse. As a result of this renaming, "prandom_" is the common prefix for pseudo-random number library. Currently, srandom32() and random32() are preserved because it is difficult to rename too many users at once. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Robert Love <robert.w.love@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu> Cc: David Laight <david.laight@aculab.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Artem Bityutskiy <dedekind1@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/random32.c')
-rw-r--r--lib/random32.c48
1 files changed, 24 insertions, 24 deletions
diff --git a/lib/random32.c b/lib/random32.c
index 938bde5876ac..d1830fade915 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -42,13 +42,13 @@
42static DEFINE_PER_CPU(struct rnd_state, net_rand_state); 42static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
43 43
44/** 44/**
45 * prandom32 - seeded pseudo-random number generator. 45 * prandom_u32_state - seeded pseudo-random number generator.
46 * @state: pointer to state structure holding seeded state. 46 * @state: pointer to state structure holding seeded state.
47 * 47 *
48 * This is used for pseudo-randomness with no outside seeding. 48 * This is used for pseudo-randomness with no outside seeding.
49 * For more random results, use random32(). 49 * For more random results, use prandom_u32().
50 */ 50 */
51u32 prandom32(struct rnd_state *state) 51u32 prandom_u32_state(struct rnd_state *state)
52{ 52{
53#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b) 53#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
54 54
@@ -58,32 +58,32 @@ u32 prandom32(struct rnd_state *state)
58 58
59 return (state->s1 ^ state->s2 ^ state->s3); 59 return (state->s1 ^ state->s2 ^ state->s3);
60} 60}
61EXPORT_SYMBOL(prandom32); 61EXPORT_SYMBOL(prandom_u32_state);
62 62
63/** 63/**
64 * random32 - pseudo random number generator 64 * prandom_u32 - pseudo random number generator
65 * 65 *
66 * A 32 bit pseudo-random number is generated using a fast 66 * A 32 bit pseudo-random number is generated using a fast
67 * algorithm suitable for simulation. This algorithm is NOT 67 * algorithm suitable for simulation. This algorithm is NOT
68 * considered safe for cryptographic use. 68 * considered safe for cryptographic use.
69 */ 69 */
70u32 random32(void) 70u32 prandom_u32(void)
71{ 71{
72 unsigned long r; 72 unsigned long r;
73 struct rnd_state *state = &get_cpu_var(net_rand_state); 73 struct rnd_state *state = &get_cpu_var(net_rand_state);
74 r = prandom32(state); 74 r = prandom_u32_state(state);
75 put_cpu_var(state); 75 put_cpu_var(state);
76 return r; 76 return r;
77} 77}
78EXPORT_SYMBOL(random32); 78EXPORT_SYMBOL(prandom_u32);
79 79
80/** 80/**
81 * srandom32 - add entropy to pseudo random number generator 81 * prandom_seed - add entropy to pseudo random number generator
82 * @seed: seed value 82 * @seed: seed value
83 * 83 *
84 * Add some additional seeding to the random32() pool. 84 * Add some additional seeding to the prandom pool.
85 */ 85 */
86void srandom32(u32 entropy) 86void prandom_seed(u32 entropy)
87{ 87{
88 int i; 88 int i;
89 /* 89 /*
@@ -95,13 +95,13 @@ void srandom32(u32 entropy)
95 state->s1 = __seed(state->s1 ^ entropy, 1); 95 state->s1 = __seed(state->s1 ^ entropy, 1);
96 } 96 }
97} 97}
98EXPORT_SYMBOL(srandom32); 98EXPORT_SYMBOL(prandom_seed);
99 99
100/* 100/*
101 * Generate some initially weak seeding values to allow 101 * Generate some initially weak seeding values to allow
102 * to start the random32() engine. 102 * to start the prandom_u32() engine.
103 */ 103 */
104static int __init random32_init(void) 104static int __init prandom_init(void)
105{ 105{
106 int i; 106 int i;
107 107
@@ -114,22 +114,22 @@ static int __init random32_init(void)
114 state->s3 = __seed(LCG(state->s2), 15); 114 state->s3 = __seed(LCG(state->s2), 15);
115 115
116 /* "warm it up" */ 116 /* "warm it up" */
117 prandom32(state); 117 prandom_u32_state(state);
118 prandom32(state); 118 prandom_u32_state(state);
119 prandom32(state); 119 prandom_u32_state(state);
120 prandom32(state); 120 prandom_u32_state(state);
121 prandom32(state); 121 prandom_u32_state(state);
122 prandom32(state); 122 prandom_u32_state(state);
123 } 123 }
124 return 0; 124 return 0;
125} 125}
126core_initcall(random32_init); 126core_initcall(prandom_init);
127 127
128/* 128/*
129 * Generate better values after random number generator 129 * Generate better values after random number generator
130 * is fully initialized. 130 * is fully initialized.
131 */ 131 */
132static int __init random32_reseed(void) 132static int __init prandom_reseed(void)
133{ 133{
134 int i; 134 int i;
135 135
@@ -143,8 +143,8 @@ static int __init random32_reseed(void)
143 state->s3 = __seed(seeds[2], 15); 143 state->s3 = __seed(seeds[2], 15);
144 144
145 /* mix it in */ 145 /* mix it in */
146 prandom32(state); 146 prandom_u32_state(state);
147 } 147 }
148 return 0; 148 return 0;
149} 149}
150late_initcall(random32_reseed); 150late_initcall(prandom_reseed);