On Thu, Jun 24, 2004 at 02:42:13PM -0400, Alan Stern wrote: > Greg: > > This patch plugs a major hole in USB device locking. Whenever a new > driver is loaded and the matching unbound interfaces are probed, no > devices are locked! Similarly, when a driver is unloaded and its > interfaces are unbound, nothing is locked. > > The patch fixes the problem by introducing a new rwsem and encapsulating > the locking procedures. To lock a single device, the new routine > usb_lock_device() gets a readlock on the rwsem and a lock on the device's > ->serialize. When drivers are loaded or removed, all devices are > effectively locked by getting a writelock on the rwsem. The rwsem is > also writelocked in one other oddball circumstance: when telling the > driver-model core to reprobe all the unbound interfaces on a bus. > > Details of the patch: > > Implement usb_lock_device(), usb_unlock_device(), > usb_lock_all_devices(), usb_unlock_all_devices(), and > usb_trylock_device(). > > Call usb_(un)lock_all_devices() when registering and > deregistering USB drivers and when calling bus_rescan_devices(). > > Convert all existing places that access usbdev->serialize > directly to make them call the appropriate locking routine. > > Add comments warning about the need to use the new routines, > and change the terminology in existing comments to talk about > locking a device rather than owning usbdev->serialize. > > Add proper locking to usb_find_device() and match_device(), > to protect against topology changes while scanning the > device tree. > > With this change, the USB device locking model is almost complete. There > remains only the need for appropriate locking for routines that call > usb_reset_device(). That patch will come next. > > Please apply.
Applied, thanks. greg k-h ------------------------------------------------------- This SF.Net email sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
