diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/hw_random/virtio-rng.c | 86 | ||||
| -rw-r--r-- | drivers/char/virtio_console.c | 9 |
2 files changed, 74 insertions, 21 deletions
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index a90001e02bf7..0a7dde135db1 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -18,13 +18,20 @@ static DEFINE_IDA(rng_index_ida); struct virtrng_info { struct hwrng hwrng; struct virtqueue *vq; - struct completion have_data; char name[25]; - unsigned int data_avail; int index; - bool busy; bool hwrng_register_done; bool hwrng_removed; + /* data transfer */ + struct completion have_data; + unsigned int data_avail; + unsigned int data_idx; + /* minimal size returned by rng_buffer_size() */ +#if SMP_CACHE_BYTES < 32 + u8 data[32]; +#else + u8 data[SMP_CACHE_BYTES]; +#endif }; static void random_recv_done(struct virtqueue *vq) @@ -35,54 +42,88 @@ static void random_recv_done(struct virtqueue *vq) if (!virtqueue_get_buf(vi->vq, &vi->data_avail)) return; + vi->data_idx = 0; + complete(&vi->have_data); } -/* The host will fill any buffer we give it with sweet, sweet randomness. */ -static void register_buffer(struct virtrng_info *vi, u8 *buf, size_t size) +static void request_entropy(struct virtrng_info *vi) { struct scatterlist sg; - sg_init_one(&sg, buf, size); + reinit_completion(&vi->have_data); + vi->data_avail = 0; + vi->data_idx = 0; + + sg_init_one(&sg, vi->data, sizeof(vi->data)); /* There should always be room for one buffer. */ - virtqueue_add_inbuf(vi->vq, &sg, 1, buf, GFP_KERNEL); + virtqueue_add_inbuf(vi->vq, &sg, 1, vi->data, GFP_KERNEL); virtqueue_kick(vi->vq); } +static unsigned int copy_data(struct virtrng_info *vi, void *buf, + unsigned int size) +{ + size = min_t(unsigned int, size, vi->data_avail); + memcpy(buf, vi->data + vi->data_idx, size); + vi->data_idx += size; + vi->data_avail -= size; + if (vi->data_avail == 0) + request_entropy(vi); + return size; +} + 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; + unsigned int chunk; + size_t read; if (vi->hwrng_removed) return -ENODEV; - if (!vi->busy) { - vi->busy = true; - reinit_completion(&vi->have_data); - register_buffer(vi, buf, size); + read = 0; + + /* copy available data */ + if (vi->data_avail) { + chunk = copy_data(vi, buf, size); + size -= chunk; + read += chunk; } if (!wait) - return 0; - - ret = wait_for_completion_killable(&vi->have_data); - if (ret < 0) - return ret; + return read; + + /* We have already copied available entropy, + * so either size is 0 or data_avail is 0 + */ + while (size != 0) { + /* data_avail is 0 but a request is pending */ + ret = wait_for_completion_killable(&vi->have_data); + if (ret < 0) + return ret; + /* if vi->data_avail is 0, we have been interrupted + * by a cleanup, but buffer stays in the queue + */ + if (vi->data_avail == 0) + return read; - vi->busy = false; + chunk = copy_data(vi, buf + read, size); + size -= chunk; + read += chunk; + } - return vi->data_avail; + return read; } static void virtio_cleanup(struct hwrng *rng) { struct virtrng_info *vi = (struct virtrng_info *)rng->priv; - if (vi->busy) - wait_for_completion(&vi->have_data); + complete(&vi->have_data); } static int probe_common(struct virtio_device *vdev) @@ -118,6 +159,9 @@ static int probe_common(struct virtio_device *vdev) goto err_find; } + /* we always have a pending entropy request */ + request_entropy(vi); + return 0; err_find: @@ -133,9 +177,9 @@ static void remove_common(struct virtio_device *vdev) vi->hwrng_removed = true; vi->data_avail = 0; + vi->data_idx = 0; complete(&vi->have_data); vdev->config->reset(vdev); - vi->busy = false; if (vi->hwrng_register_done) hwrng_unregister(&vi->hwrng); vdev->config->del_vqs(vdev); diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7eaf303a7a86..660c5c388c29 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -28,6 +28,7 @@ #include "../tty/hvc/hvc_console.h" #define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC) +#define VIRTCONS_MAX_PORTS 0x8000 /* * This is a global struct for storing common data for all the devices @@ -2036,6 +2037,14 @@ static int virtcons_probe(struct virtio_device *vdev) virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT, struct virtio_console_config, max_nr_ports, &portdev->max_nr_ports) == 0) { + if (portdev->max_nr_ports == 0 || + portdev->max_nr_ports > VIRTCONS_MAX_PORTS) { + dev_err(&vdev->dev, + "Invalidate max_nr_ports %d", + portdev->max_nr_ports); + err = -EINVAL; + goto free; + } multiport = true; } |