[RFC PATCH 3/3] Revert "virtio: rng: ensure reads happen after successful probe"

From: Amit Shah
Date: Mon Jul 14 2014 - 00:36:43 EST


This reverts commit ceb5d72a2e27e95bc9570ce259c45b35f0e23462.

This commit was added for -stable so systems with virtio-rng don't
freeze at boot-time.

With the addition of the previous commits that delay the request for
initial randomness after probe() is successful, this is no longer
needed.

CC: Kees Cook <keescook@xxxxxxxxxxxx>
CC: Jason Cooper <jason@xxxxxxxxxxxxxx>
CC: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx>
---
drivers/char/hw_random/core.c | 6 ------
drivers/char/hw_random/virtio-rng.c | 10 ----------
2 files changed, 16 deletions(-)

diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 2a765fd..148d9be 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -68,12 +68,6 @@ static void get_early_randomness(struct hwrng *rng)
unsigned char bytes[16];
int bytes_read;

- /*
- * Currently only virtio-rng cannot return data during device
- * probe, and that's handled in virtio-rng.c itself. If there
- * are more such devices, this call to rng_get_data can be
- * made conditional here instead of doing it per-device.
- */
bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1);
if (bytes_read > 0)
add_device_randomness(bytes, bytes_read);
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index f53f1e8..f7d1573 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -37,8 +37,6 @@ struct virtrng_info {
int index;
};

-static bool probe_done;
-
static void random_recv_done(struct virtqueue *vq)
{
struct virtrng_info *vi = vq->vdev->priv;
@@ -68,13 +66,6 @@ static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
int ret;
struct virtrng_info *vi = (struct virtrng_info *)rng->priv;

- /*
- * Don't ask host for data till we're setup. This call can
- * happen during hwrng_register(), after commit d9e7972619.
- */
- if (unlikely(!probe_done))
- return 0;
-
if (!vi->busy) {
vi->busy = true;
init_completion(&vi->have_data);
@@ -146,7 +137,6 @@ static int probe_common(struct virtio_device *vdev)
return err;
}

- probe_done = true;
return 0;
}

--
1.9.3

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