[$] How to unbreak LTTng

Back in February, the kernel community discussed the removal of a couple of functionsthat could be used by loadable modules to gain access to symbols (functionsand data structures) that were not meant to be available to them. Thatchange was mergedduring the 5.7 merge window. This change will break a number of externalmodules that depended on the removed functions; since many of those modulesare proprietary, this fact does not cause a great deal of anguish in thekernel community. But there are a few out-of-tree modules withGPL-compatible licenses that are also affected by this change; one of thoseis LTTng. Fixing LTTng may not beentirely straightforward.