diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/virtio_console.c | 70 |
1 files changed, 48 insertions, 22 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 1b456fe9b87a..fc45567ad3ac 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -272,9 +272,12 @@ static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev, unsigned long flags; spin_lock_irqsave(&portdev->ports_lock, flags); - list_for_each_entry(port, &portdev->ports, list) - if (port->cdev->dev == dev) + list_for_each_entry(port, &portdev->ports, list) { + if (port->cdev->dev == dev) { + kref_get(&port->kref); goto out; + } + } port = NULL; out: spin_unlock_irqrestore(&portdev->ports_lock, flags); @@ -746,6 +749,10 @@ static ssize_t port_fops_read(struct file *filp, char __user *ubuf, port = filp->private_data; + /* Port is hot-unplugged. */ + if (!port->guest_connected) + return -ENODEV; + if (!port_has_data(port)) { /* * If nothing's connected on the host just return 0 in @@ -762,7 +769,7 @@ static ssize_t port_fops_read(struct file *filp, char __user *ubuf, if (ret < 0) return ret; } - /* Port got hot-unplugged. */ + /* Port got hot-unplugged while we were waiting above. */ if (!port->guest_connected) return -ENODEV; /* @@ -932,13 +939,25 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe, if (is_rproc_serial(port->out_vq->vdev)) return -EINVAL; + /* + * pipe->nrbufs == 0 means there are no data to transfer, + * so this returns just 0 for no data. + */ + pipe_lock(pipe); + if (!pipe->nrbufs) { + ret = 0; + goto error_out; + } + ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK); if (ret < 0) - return ret; + goto error_out; buf = alloc_buf(port->out_vq, 0, pipe->nrbufs); - if (!buf) - return -ENOMEM; + if (!buf) { + ret = -ENOMEM; + goto error_out; + } sgl.n = 0; sgl.len = 0; @@ -946,12 +965,17 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe, sgl.sg = buf->sg; sg_init_table(sgl.sg, sgl.size); ret = __splice_from_pipe(pipe, &sd, pipe_to_sg); + pipe_unlock(pipe); if (likely(ret > 0)) ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true); if (unlikely(ret <= 0)) free_buf(buf, true); return ret; + +error_out: + pipe_unlock(pipe); + return ret; } static unsigned int port_fops_poll(struct file *filp, poll_table *wait) @@ -1019,14 +1043,14 @@ static int port_fops_open(struct inode *inode, struct file *filp) struct port *port; int ret; + /* We get the port with a kref here */ port = find_port_by_devt(cdev->dev); + if (!port) { + /* Port was unplugged before we could proceed */ + return -ENXIO; + } filp->private_data = port; - /* Prevent against a port getting hot-unplugged at the same time */ - spin_lock_irq(&port->portdev->ports_lock); - kref_get(&port->kref); - spin_unlock_irq(&port->portdev->ports_lock); - /* * Don't allow opening of console port devices -- that's done * via /dev/hvc @@ -1498,14 +1522,6 @@ static void remove_port(struct kref *kref) port = container_of(kref, struct port, kref); - sysfs_remove_group(&port->dev->kobj, &port_attribute_group); - device_destroy(pdrvdata.class, port->dev->devt); - cdev_del(port->cdev); - - kfree(port->name); - - debugfs_remove(port->debugfs_file); - kfree(port); } @@ -1539,12 +1555,14 @@ static void unplug_port(struct port *port) spin_unlock_irq(&port->portdev->ports_lock); if (port->guest_connected) { + /* Let the app know the port is going down. */ + send_sigio_to_port(port); + + /* Do this after sigio is actually sent */ port->guest_connected = false; port->host_connected = false; - wake_up_interruptible(&port->waitqueue); - /* Let the app know the port is going down. */ - send_sigio_to_port(port); + wake_up_interruptible(&port->waitqueue); } if (is_console_port(port)) { @@ -1563,6 +1581,14 @@ static void unplug_port(struct port *port) */ port->portdev = NULL; + sysfs_remove_group(&port->dev->kobj, &port_attribute_group); + device_destroy(pdrvdata.class, port->dev->devt); + cdev_del(port->cdev); + + kfree(port->name); + + debugfs_remove(port->debugfs_file); + /* * Locks around here are not necessary - a port can't be * opened after we removed the port struct from ports_list |