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authorKees Cook <keescook@chromium.org>2014-03-03 15:51:48 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2014-03-10 20:17:06 +0800
commitd9e79726193346569af7953369a638ee2275ade5 (patch)
tree8818f3e2b0c63d1e9eca6336e9448d29523c0d6c /drivers/char/hw_random/core.c
parent04d088cc0b19a4cb14680b92205fd4600470c46f (diff)
downloadblackbird-op-linux-d9e79726193346569af7953369a638ee2275ade5.tar.gz
blackbird-op-linux-d9e79726193346569af7953369a638ee2275ade5.zip
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 <keescook@chromium.org> Reviewed-by: Jason Cooper <jason@lakedaemon.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char/hw_random/core.c')
-rw-r--r--drivers/char/hw_random/core.c7
1 files changed, 7 insertions, 0 deletions
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 <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/slab.h>
+#include <linux/random.h>
#include <asm/uaccess.h>
@@ -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:
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