From f49819560f53b7f3a596a8ea2e6764dc86695b62 Mon Sep 17 00:00:00 2001 From: Amos Kong Date: Thu, 11 Sep 2014 22:21:53 +0930 Subject: [PATCH] virtio-rng: skip reading when we start to remove the device Before we really unregister the hwrng device, reading will get stuck if the virtio device is reset. We should return error for reading when we start to remove the device. Signed-off-by: Amos Kong Reviewed-by: Amit Shah Cc: stable@vger.kernel.org Signed-off-by: Rusty Russell --- drivers/char/hw_random/virtio-rng.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 849b22877196..132c9ccfdc62 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -36,6 +36,7 @@ struct virtrng_info { int index; bool busy; bool hwrng_register_done; + bool hwrng_removed; }; @@ -68,6 +69,9 @@ 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; + if (vi->hwrng_removed) + return -ENODEV; + if (!vi->busy) { vi->busy = true; init_completion(&vi->have_data); @@ -137,6 +141,7 @@ static void remove_common(struct virtio_device *vdev) { struct virtrng_info *vi = vdev->priv; + vi->hwrng_removed = true; vi->data_avail = 0; complete(&vi->have_data); vdev->config->reset(vdev);