Commit 10766dde authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman

[PATCH] USB: set_configuration locking cleanups

I've posted all these before, the only notable change is
treating that one gphoto2 case as warn-and-continue rather
than return-with-failure.


usb_set_configuration() cleanup

 * Remove it from the USB kernel driver API.  No drivers need it now,
   and the sysadmin can change bConfigurationValue using sysfs (say,
   when hotplugging an otherwise problematic device).

 * Simpler/cleaner locking:  caller must own dev->serialize.

 * Access from usbfs now uses usb_reset_configuration() sometimes,
   preventing sysfs thrash, and warns about some dangerous usage
   (which gphoto2 and other programs may be relying on).  (This is
   from Alan Stern, but I morphed an error return into a warning.)

 * Prevent a couple potential "no configuration" oopses. (Alan's?)

 * Remove one broken call from usbcore,  in the "device morphed" path
   of usb_reset_device().  This should be more polite now, hanging
   that one device rather than khubd.
parent 394d7256
......@@ -430,6 +430,8 @@ static int findintfep(struct usb_device *dev, unsigned int ep)
if (ep & ~(USB_DIR_IN|0xf))
return -EINVAL;
if (!dev->actconfig)
return -ESRCH;
for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
iface = dev->actconfig->interface[i];
for (j = 0; j < iface->num_altsetting; j++) {
......@@ -450,6 +452,8 @@ static int findintfif(struct usb_device *dev, unsigned int ifn)
if (ifn & ~0xff)
return -EINVAL;
if (!dev->actconfig)
return -ESRCH;
for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
if (dev->actconfig->interface[i]->
altsetting[0].desc.bInterfaceNumber == ifn)
......@@ -766,10 +770,51 @@ static int proc_setintf(struct dev_state *ps, void __user *arg)
static int proc_setconfig(struct dev_state *ps, void __user *arg)
{
unsigned int u;
int status = 0;
struct usb_host_config *actconfig;
if (get_user(u, (unsigned int __user *)arg))
return -EFAULT;
return usb_set_configuration(ps->dev, u);
down(&ps->dev->serialize);
actconfig = ps->dev->actconfig;
/* Don't touch the device if any interfaces are claimed.
* It could interfere with other drivers' operations, and if
* an interface is claimed by usbfs it could easily deadlock.
*/
if (actconfig) {
int i;
for (i = 0; i < actconfig->desc.bNumInterfaces; ++i) {
if (usb_interface_claimed(actconfig->interface[i])) {
dev_warn (&ps->dev->dev,
"usbfs: interface %d claimed "
"while '%s' sets config #%d\n",
actconfig->interface[i]
->cur_altsetting
->desc.bInterfaceNumber,
current->comm, u);
#if 0 /* FIXME: enable in 2.6.10 or so */
status = -EBUSY;
break;
#endif
}
}
}
/* SET_CONFIGURATION is often abused as a "cheap" driver reset,
* so avoid usb_set_configuration()'s kick to sysfs
*/
if (status == 0) {
if (actconfig && actconfig->desc.bConfigurationValue == u)
status = usb_reset_configuration(ps->dev);
else
status = usb_set_configuration(ps->dev, u);
}
up(&ps->dev->serialize);
return status;
}
static int proc_submiturb(struct dev_state *ps, void __user *arg)
......
......@@ -55,7 +55,9 @@ set_bConfigurationValue (struct device *dev, const char *buf, size_t count)
if (sscanf (buf, "%u", &config) != 1 || config > 255)
return -EINVAL;
down(&udev->serialize);
value = usb_set_configuration (udev, config);
up(&udev->serialize);
return (value < 0) ? value : count;
}
......
......@@ -1299,33 +1299,15 @@ int usb_physical_reset_device(struct usb_device *dev)
kfree(descriptor);
usb_destroy_configuration(dev);
ret = usb_get_device_descriptor(dev, sizeof(dev->descriptor));
if (ret != sizeof(dev->descriptor)) {
if (ret < 0)
err("unable to get device %s descriptor "
"(error=%d)", dev->devpath, ret);
else
err("USB device %s descriptor short read "
"(expected %Zi, got %i)",
dev->devpath,
sizeof(dev->descriptor), ret);
clear_bit(dev->devnum, dev->bus->devmap.devicemap);
dev->devnum = -1;
return -EIO;
}
ret = usb_get_configuration(dev);
if (ret < 0) {
err("unable to get configuration (error=%d)", ret);
usb_destroy_configuration(dev);
clear_bit(dev->devnum, dev->bus->devmap.devicemap);
dev->devnum = -1;
return 1;
}
/* FIXME Linux doesn't yet handle these "device morphed"
* paths. DFU variants need this to work ... and they
* include the "config descriptors changed" case this
* doesn't yet detect!
*/
dev->state = USB_STATE_NOTATTACHED;
dev_err(&dev->dev, "device morphed (DFU?), nyet supported\n");
usb_set_configuration(dev, dev->config[0].desc.bConfigurationValue);
return 1;
return -ENODEV;
}
kfree(descriptor);
......
......@@ -1075,11 +1075,11 @@ int usb_reset_configuration(struct usb_device *dev)
return 0;
}
/**
/*
* usb_set_configuration - Makes a particular device setting be current
* @dev: the device whose configuration is being updated
* @configuration: the configuration being chosen.
* Context: !in_interrupt ()
* Context: !in_interrupt(), caller holds dev->serialize
*
* This is used to enable non-default device modes. Not all devices
* use this kind of configurability; many devices only have one
......@@ -1115,7 +1115,6 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
struct usb_host_config *cp = NULL;
/* dev->serialize guards all config changes */
down(&dev->serialize);
for (i=0; i<dev->descriptor.bNumConfigurations; i++) {
if (dev->config[i].desc.bConfigurationValue == configuration) {
......@@ -1191,7 +1190,6 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
}
out:
up(&dev->serialize);
return ret;
}
......@@ -1300,6 +1298,5 @@ EXPORT_SYMBOL(usb_string);
// synchronous calls that also maintain usbcore state
EXPORT_SYMBOL(usb_clear_halt);
EXPORT_SYMBOL(usb_reset_configuration);
EXPORT_SYMBOL(usb_set_configuration);
EXPORT_SYMBOL(usb_set_interface);
......@@ -1173,10 +1173,13 @@ int usb_new_device(struct usb_device *dev)
usb_show_string(dev, "SerialNumber", dev->descriptor.iSerialNumber);
#endif
down(&dev->serialize);
/* put device-specific files into sysfs */
err = device_add (&dev->dev);
if (err) {
dev_err(&dev->dev, "can't device_add, error %d\n", err);
up(&dev->serialize);
goto fail;
}
usb_create_driverfs_dev_files (dev);
......@@ -1211,6 +1214,7 @@ int usb_new_device(struct usb_device *dev)
dev->descriptor.bNumConfigurations);
}
err = usb_set_configuration(dev, config);
up(&dev->serialize);
if (err) {
dev_err(&dev->dev, "can't set config #%d, error %d\n",
config, err);
......
......@@ -17,6 +17,7 @@ extern void usb_enable_interface (struct usb_device *dev,
extern int usb_get_device_descriptor(struct usb_device *dev,
unsigned int size);
extern int usb_set_configuration(struct usb_device *dev, int configuration);
/* for labeling diagnostics */
extern const char *usbcore_name;
......@@ -904,7 +904,6 @@ extern int usb_string(struct usb_device *dev, int index,
/* wrappers that also update important state inside usbcore */
extern int usb_clear_halt(struct usb_device *dev, int pipe);
extern int usb_reset_configuration(struct usb_device *dev);
extern int usb_set_configuration(struct usb_device *dev, int configuration);
extern int usb_set_interface(struct usb_device *dev, int ifnum, int alternate);
/*
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment