On Mon, Jun 14, 2010 at 12:15:41PM +0100, Andy Whitcroft wrote: > With the introduction of wireless USB hubs the product, manufacturer, > and serial number are now mutable. Changable by whom? The device itself? This has always been the case, although it is usually very rare for a device to do this. > This necessitates new locking in the gconsumers of these values > including the sysfs read routines in order to prevent use-after-free > acces to these values. Who would access them after they go away? > These extra locks create significant lock contention leading to > increased boot times (0.3s for an example Atom based system). Who is doing all of the deauthorization at boot time that this would ever matter at all? > Move update of these values to RCU based locking. Ick. What has changed that necessitates this? You discuss a variety of different things in this bug report: > BugLink: http://bugs.launchpad.net/bugs/510937 Which would have been nice to dicuss with the people on these lists. I really don't think this is the correct fix, as a normal boot path shouldn't be having non-authorized usb devices, right? And from that bug, once the machine is up and running, there is no contention here, right? not convinced, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
