Merge branch 'x86-rdrand-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

* 'x86-rdrand-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  random: Use arch_get_random_int instead of cycle counter if avail

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 6035ab8d5ef7e25e6eae89fbfdc53476f248de8b..85da8740586b3dbe381373d6f7e52d6b348329ac 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -624,8 +624,8 @@ static struct timer_rand_state input_timer_state;
 static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
 {
        struct {
-               cycles_t cycles;
                long jiffies;
+               unsigned cycles;
                unsigned num;
        } sample;
        long delta, delta2, delta3;
@@ -637,7 +637,11 @@ static void add_timer_randomness(struct timer_rand_state *state, unsigned num)
                goto out;
 
        sample.jiffies = jiffies;
-       sample.cycles = get_cycles();
+
+       /* Use arch random value, fall back to cycles */
+       if (!arch_get_random_int(&sample.cycles))
+               sample.cycles = get_cycles();
+
        sample.num = num;
        mix_pool_bytes(&input_pool, &sample, sizeof(sample));