Merge remote-tracking branch 'asoc/fix/core' into tmp

[~andy/linux] / lib / random32.c

diff --git a/lib/random32.c b/lib/random32.c
index d1830fade91530fccb5698645e4d664c8b8f46b0..52280d5526be7e8e021dd204c662d3103e6d6726 100644 (file)
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -77,6 +77,55 @@ u32 prandom_u32(void)
 }
 EXPORT_SYMBOL(prandom_u32);
 
+/*
+ *     prandom_bytes_state - get the requested number of pseudo-random bytes
+ *
+ *     @state: pointer to state structure holding seeded state.
+ *     @buf: where to copy the pseudo-random bytes to
+ *     @bytes: the requested number of bytes
+ *
+ *     This is used for pseudo-randomness with no outside seeding.
+ *     For more random results, use prandom_bytes().
+ */
+void prandom_bytes_state(struct rnd_state *state, void *buf, int bytes)
+{
+       unsigned char *p = buf;
+       int i;
+
+       for (i = 0; i < round_down(bytes, sizeof(u32)); i += sizeof(u32)) {
+               u32 random = prandom_u32_state(state);
+               int j;
+
+               for (j = 0; j < sizeof(u32); j++) {
+                       p[i + j] = random;
+                       random >>= BITS_PER_BYTE;
+               }
+       }
+       if (i < bytes) {
+               u32 random = prandom_u32_state(state);
+
+               for (; i < bytes; i++) {
+                       p[i] = random;
+                       random >>= BITS_PER_BYTE;
+               }
+       }
+}
+EXPORT_SYMBOL(prandom_bytes_state);
+
+/**
+ *     prandom_bytes - get the requested number of pseudo-random bytes
+ *     @buf: where to copy the pseudo-random bytes to
+ *     @bytes: the requested number of bytes
+ */
+void prandom_bytes(void *buf, int bytes)
+{
+       struct rnd_state *state = &get_cpu_var(net_rand_state);
+
+       prandom_bytes_state(state, buf, bytes);
+       put_cpu_var(state);
+}
+EXPORT_SYMBOL(prandom_bytes);
+
 /**
  *     prandom_seed - add entropy to pseudo random number generator
  *     @seed: seed value