diff options
Diffstat (limited to 'drivers/usb/class/usbtmc.c')
| -rw-r--r-- | drivers/usb/class/usbtmc.c | 56 |
1 files changed, 51 insertions, 5 deletions
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index b09a527f7341..40ef4da786d8 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -86,6 +86,8 @@ struct usbtmc_device_data { bool TermCharEnabled; bool auto_abort; + bool zombie; /* fd of disconnected device */ + struct usbtmc_dev_capabilities capabilities; struct kref kref; struct mutex io_mutex; /* only one i/o function running at a time */ @@ -367,13 +369,13 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf, { struct usbtmc_device_data *data; struct device *dev; - unsigned long int n_characters; + u32 n_characters; u8 *buffer; int actual; - int done; - int remaining; + size_t done; + size_t remaining; int retval; - int this_part; + size_t this_part; /* Get pointer to private data structure */ data = filp->private_data; @@ -384,6 +386,10 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf, return -ENOMEM; mutex_lock(&data->io_mutex); + if (data->zombie) { + retval = -ENODEV; + goto exit; + } remaining = count; done = 0; @@ -455,6 +461,18 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf, (buffer[6] << 16) + (buffer[7] << 24); + /* Ensure the instrument doesn't lie about it */ + if(n_characters > actual - 12) { + dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12); + n_characters = actual - 12; + } + + /* Ensure the instrument doesn't send more back than requested */ + if(n_characters > this_part) { + dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part); + n_characters = this_part; + } + /* Copy buffer to user space */ if (copy_to_user(buf + done, &buffer[12], n_characters)) { /* There must have been an addressing problem */ @@ -465,6 +483,8 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf, done += n_characters; if (n_characters < USBTMC_SIZE_IOBUFFER) remaining = 0; + else + remaining -= n_characters; } /* Update file position value */ @@ -496,6 +516,10 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf, return -ENOMEM; mutex_lock(&data->io_mutex); + if (data->zombie) { + retval = -ENODEV; + goto exit; + } remaining = count; done = 0; @@ -925,6 +949,10 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) data = file->private_data; mutex_lock(&data->io_mutex); + if (data->zombie) { + retval = -ENODEV; + goto skip_io_on_zombie; + } switch (cmd) { case USBTMC_IOCTL_CLEAR_OUT_HALT: @@ -952,6 +980,7 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) break; } +skip_io_on_zombie: mutex_unlock(&data->io_mutex); return retval; } @@ -995,6 +1024,7 @@ static int usbtmc_probe(struct usb_interface *intf, usb_set_intfdata(intf, data); kref_init(&data->kref); mutex_init(&data->io_mutex); + data->zombie = 0; /* Initialize USBTMC bTag and other fields */ data->bTag = 1; @@ -1065,14 +1095,30 @@ static void usbtmc_disconnect(struct usb_interface *intf) usb_deregister_dev(intf, &usbtmc_class); sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp); sysfs_remove_group(&intf->dev.kobj, &data_attr_grp); + mutex_lock(&data->io_mutex); + data->zombie = 1; + mutex_unlock(&data->io_mutex); kref_put(&data->kref, usbtmc_delete); } +static int usbtmc_suspend (struct usb_interface *intf, pm_message_t message) +{ + /* this driver does not have pending URBs */ + return 0; +} + +static int usbtmc_resume (struct usb_interface *intf) +{ + return 0; +} + static struct usb_driver usbtmc_driver = { .name = "usbtmc", .id_table = usbtmc_devices, .probe = usbtmc_probe, - .disconnect = usbtmc_disconnect + .disconnect = usbtmc_disconnect, + .suspend = usbtmc_suspend, + .resume = usbtmc_resume, }; static int __init usbtmc_init(void) |