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path: root/drivers/char/virtio_console.c
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Diffstat (limited to 'drivers/char/virtio_console.c')
-rw-r--r--drivers/char/virtio_console.c93
1 files changed, 62 insertions, 31 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 1b456fe9b87a..b79cf3e1b793 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);
}
@@ -1513,18 +1529,22 @@ static void remove_port_data(struct port *port)
{
struct port_buffer *buf;
+ spin_lock_irq(&port->inbuf_lock);
/* Remove unused data this port might have received. */
discard_port_data(port);
- reclaim_consumed_buffers(port);
-
/* Remove buffers we queued up for the Host to send us data in. */
while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
free_buf(buf, true);
+ spin_unlock_irq(&port->inbuf_lock);
+
+ spin_lock_irq(&port->outvq_lock);
+ reclaim_consumed_buffers(port);
/* Free pending buffers from the out-queue. */
while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
free_buf(buf, true);
+ spin_unlock_irq(&port->outvq_lock);
}
/*
@@ -1538,14 +1558,18 @@ static void unplug_port(struct port *port)
list_del(&port->list);
spin_unlock_irq(&port->portdev->ports_lock);
+ spin_lock_irq(&port->inbuf_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);
}
+ spin_unlock_irq(&port->inbuf_lock);
if (is_console_port(port)) {
spin_lock_irq(&pdrvdata_lock);
@@ -1563,6 +1587,13 @@ 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);
+
+ debugfs_remove(port->debugfs_file);
+ kfree(port->name);
+
/*
* Locks around here are not necessary - a port can't be
* opened after we removed the port struct from ports_list
@@ -1655,7 +1686,9 @@ static void handle_control_message(struct ports_device *portdev,
* If the guest is connected, it'll be interested in
* knowing the host connection state changed.
*/
+ spin_lock_irq(&port->inbuf_lock);
send_sigio_to_port(port);
+ spin_unlock_irq(&port->inbuf_lock);
break;
case VIRTIO_CONSOLE_PORT_NAME:
/*
@@ -1775,13 +1808,13 @@ static void in_intr(struct virtqueue *vq)
if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
discard_port_data(port);
+ /* Send a SIGIO indicating new data in case the process asked for it */
+ send_sigio_to_port(port);
+
spin_unlock_irqrestore(&port->inbuf_lock, flags);
wake_up_interruptible(&port->waitqueue);
- /* Send a SIGIO indicating new data in case the process asked for it */
- send_sigio_to_port(port);
-
if (is_console_port(port) && hvc_poll(port->cons.hvc))
hvc_kick();
}
@@ -2215,10 +2248,8 @@ static int __init init(void)
}
pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
- if (!pdrvdata.debugfs_dir) {
- pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
- PTR_ERR(pdrvdata.debugfs_dir));
- }
+ if (!pdrvdata.debugfs_dir)
+ pr_warning("Error creating debugfs dir for virtio-ports\n");
INIT_LIST_HEAD(&pdrvdata.consoles);
INIT_LIST_HEAD(&pdrvdata.portdevs);
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-30 13:14:06 +0000