From d9e79726193346569af7953369a638ee2275ade5 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 3 Mar 2014 15:51:48 -0800 Subject: [PATCH] hwrng: add randomness to system from rng sources When bringing a new RNG source online, it seems like it would make sense to use some of its bytes to make the system entropy pool more random, as done with all sorts of other devices that contain per-device or per-boot differences. Signed-off-by: Kees Cook Reviewed-by: Jason Cooper Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index cf49f1c88f01..7ac96fbc06ed 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -41,6 +41,7 @@ #include #include #include +#include #include @@ -304,6 +305,8 @@ int hwrng_register(struct hwrng *rng) { int err = -EINVAL; struct hwrng *old_rng, *tmp; + unsigned char bytes[16]; + int bytes_read; if (rng->name == NULL || (rng->data_read == NULL && rng->read == NULL)) @@ -344,6 +347,10 @@ int hwrng_register(struct hwrng *rng) } INIT_LIST_HEAD(&rng->list); list_add_tail(&rng->list, &rng_list); + + bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1); + if (bytes_read > 0) + add_device_randomness(bytes, bytes_read); out_unlock: mutex_unlock(&rng_mutex); out: