On Thu, 2019-04-04 at 11:28 +0100, Chris Wilson wrote: > Quoting Janusz Krzysztofik (2019-04-04 11:24:45) > > From: Janusz Krzysztofik <janusz.krzysztofik@xxxxxxxxx> > > > > In case the driver gets unbound while a device is open, kernel > > panic > > may be forced if a list of allocated context IDs is not empty. > > > > When a device is open, the list may happen to be not empty because > > a > > context ID, once allocated by a context ID allocator to a context > > assosiated with that open file descriptor, is released as late as > > on device close. > > > > On the other hand, there is a need to release all allocated context > > IDs > > and destroy the context ID allocator on driver unbind, even if a > > device > > is open, in order to free memory resources consumed and prevent > > from > > memory leaks. The purpose of the forced kernel panic was to > > protect > > the context ID allocator from being silently destroyed if not all > > allocated IDs had been released. > > Those open fd are still pointing into kernel memory where the driver > used to be. The panic is entirely correct, we should not be unloading > the module before those dangling pointers have been made safe. > > This is papering over the symptom. How is the module being unloaded > with > open fd? A user can play with the driver unbind or device remove sysfs interface. Thanks, Janusz > If all the fd have been closed, how have we failed to flush and > retire all requests (thereby unpinning the contexts and all other > pointers). > -Chris > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
