[v3,3/5] random: Seed pools from arch_get_slow_rng_u64 at startup

Commit Message

Andy Lutomirski July 16, 2014, 9:45 p.m. UTC

This should help solve the problem of guests starting out with
predictable RNG state.

Signed-off-by: Andy Lutomirski <[e-mail]>
---
 drivers/char/random.c | 7 +++++++
 1 file changed, 7 insertions(+)

Patch

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 0a7ac0a..17ad33d 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1261,6 +1261,13 @@  static void init_std_data(struct entropy_store *r)
 		mix_pool_bytes(r, &rv, sizeof(rv), NULL);
 	}
 	mix_pool_bytes(r, utsname(), sizeof(*(utsname())), NULL);
+
+	for (i = 0; i < 4; i++) {
+		u64 rv64;
+
+		if (arch_get_slow_rng_u64(&rv64))
+			mix_pool_bytes(r, &rv64, sizeof(rv64), NULL);
+	}
 }
 
 /*