On Sat, 2 Dec 2006, Pavel Machek wrote: > Hi! > > > > We send fake signals to them, so they enter get_signal_to_deliver() and they > > > call try_to_freeze() from there. > > > > Well then, see, you're doing exactly what you said should never happen -- > > you are freezing a user thread while it might be holding a lock that the > > unfreezable usb-storage thread needs. > > > I do not think it is okay to call get_signal_to_deliver with *any* > lock held... Or do you have example when that is broken? Is get_signal_to_deliver() ever called at any time other than when the CPU is about to switch back into user mode? If not then there shouldn't be any problem. The routines I was talking about earlier hold the USB device locks while running in kernel mode, but they release them before returning to user mode. Alan Stern
