hwrng: virtio - ensure reads happen after successful probe
authorAmit Shah <amit.shah@redhat.com>
Thu, 10 Jul 2014 10:12:35 +0000 (15:42 +0530)
committerHerbert Xu <herbert@gondor.apana.org.au>
Mon, 14 Jul 2014 12:48:17 +0000 (20:48 +0800)
commite052dbf554610e2104c5a7518c4d8374bed701bb
treeb765a30d4833a04b7576eae0364bcd2d725ac8d0
parentd3cc7996473a7bdd33256029988ea690754e4e2a
hwrng: virtio - ensure reads happen after successful probe

The hwrng core asks for random data in the hwrng_register() call itself
from commit d9e7972619.  This doesn't play well with virtio -- the
DRIVER_OK bit is only set by virtio core on a successful probe, and
we're not yet out of our probe routine when this call is made.  This
causes the host to not acknowledge any requests we put in the virtqueue,
and the insmod or kernel boot process just waits for data to arrive from
the host, which never happens.

CC: Kees Cook <keescook@chromium.org>
CC: Jason Cooper <jason@lakedaemon.net>
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: <stable@vger.kernel.org> # For v3.15+
Reviewed-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
drivers/char/hw_random/core.c
drivers/char/hw_random/virtio-rng.c