ARM: 8161/1: footbridge: select machine dir based on ARCH_FOOTBRIDGE

[pandora-kernel.git] / lib / random32.c

diff --git a/lib/random32.c b/lib/random32.c
index fa5da61..c9b6bf3 100644 (file)
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -40,6 +40,10 @@
 
 #ifdef CONFIG_RANDOM32_SELFTEST
 static void __init prandom_state_selftest(void);
+#else
+static inline void prandom_state_selftest(void)
+{
+}
 #endif
 
 static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
@@ -53,8 +57,7 @@ static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
  */
 u32 prandom_u32_state(struct rnd_state *state)
 {
-#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
-
+#define TAUSWORTHE(s, a, b, c, d) ((s & c) << d) ^ (((s << a) ^ s) >> b)
        state->s1 = TAUSWORTHE(state->s1,  6U, 13U, 4294967294U, 18U);
        state->s2 = TAUSWORTHE(state->s2,  2U, 27U, 4294967288U,  2U);
        state->s3 = TAUSWORTHE(state->s3, 13U, 21U, 4294967280U,  7U);
@@ -147,21 +150,25 @@ static void prandom_warmup(struct rnd_state *state)
        prandom_u32_state(state);
 }
 
-static void prandom_seed_very_weak(struct rnd_state *state, u32 seed)
+static u32 __extract_hwseed(void)
 {
-       /* Note: This sort of seeding is ONLY used in test cases and
-        * during boot at the time from core_initcall until late_initcall
-        * as we don't have a stronger entropy source available yet.
-        * After late_initcall, we reseed entire state, we have to (!),
-        * otherwise an attacker just needs to search 32 bit space to
-        * probe for our internal 128 bit state if he knows a couple
-        * of prandom32 outputs!
-        */
-#define LCG(x) ((x) * 69069U)  /* super-duper LCG */
-       state->s1 = __seed(LCG(seed),        2U);
-       state->s2 = __seed(LCG(state->s1),   8U);
-       state->s3 = __seed(LCG(state->s2),  16U);
-       state->s4 = __seed(LCG(state->s3), 128U);
+       u32 val = 0;
+
+       (void)(arch_get_random_seed_int(&val) ||
+              arch_get_random_int(&val));
+
+       return val;
+}
+
+static void prandom_seed_early(struct rnd_state *state, u32 seed,
+                              bool mix_with_hwseed)
+{
+#define LCG(x)  ((x) * 69069U) /* super-duper LCG */
+#define HWSEED() (mix_with_hwseed ? __extract_hwseed() : 0)
+       state->s1 = __seed(HWSEED() ^ LCG(seed),        2U);
+       state->s2 = __seed(HWSEED() ^ LCG(state->s1),   8U);
+       state->s3 = __seed(HWSEED() ^ LCG(state->s2),  16U);
+       state->s4 = __seed(HWSEED() ^ LCG(state->s3), 128U);
 }
 
 /**
@@ -194,14 +201,13 @@ static int __init prandom_init(void)
 {
        int i;
 
-#ifdef CONFIG_RANDOM32_SELFTEST
        prandom_state_selftest();
-#endif
 
        for_each_possible_cpu(i) {
                struct rnd_state *state = &per_cpu(net_rand_state,i);
+               u32 weak_seed = (i + jiffies) ^ random_get_entropy();
 
-               prandom_seed_very_weak(state, (i + jiffies) ^ random_get_entropy());
+               prandom_seed_early(state, weak_seed, true);
                prandom_warmup(state);
        }
 
@@ -210,6 +216,7 @@ static int __init prandom_init(void)
 core_initcall(prandom_init);
 
 static void __prandom_timer(unsigned long dontcare);
+
 static DEFINE_TIMER(seed_timer, __prandom_timer, 0, 0);
 
 static void __prandom_timer(unsigned long dontcare)
@@ -419,7 +426,7 @@ static void __init prandom_state_selftest(void)
        for (i = 0; i < ARRAY_SIZE(test1); i++) {
                struct rnd_state state;
 
-               prandom_seed_very_weak(&state, test1[i].seed);
+               prandom_seed_early(&state, test1[i].seed, false);
                prandom_warmup(&state);
 
                if (test1[i].result != prandom_u32_state(&state))
@@ -434,7 +441,7 @@ static void __init prandom_state_selftest(void)
        for (i = 0; i < ARRAY_SIZE(test2); i++) {
                struct rnd_state state;
 
-               prandom_seed_very_weak(&state, test2[i].seed);
+               prandom_seed_early(&state, test2[i].seed, false);
                prandom_warmup(&state);
 
                for (j = 0; j < test2[i].iteration - 1; j++)