On Fri, 9 Dec 2016 15:36:04 +0100 Stanislav Kozina <skozina@xxxxxxxxxx> wrote: > >>>> The question is how to provide a similar guarantee if a different way? > >>> As a tool to aid distro reviewers, modversions has some value, but the > >>> debug info parsing tools that have been mentioned in this thread seem > >>> superior (not that I've tested them). > >> On the other hand the big advantage of modversions is that it also > >> verifies the checksum during runtime (module loading). In other words, I > >> believe that any other solution should still generate some form of > >> checksum/watermark which can be easily checked for compatibility on > >> module load. > >> It should not be hard to add to the DWARF based tools though. We'd just > >> parse DWARF data instead of the C code. > > A runtime check is still done, with per-module vermagic which distros > > can change when they bump the ABI version. Is it really necessary to > > have more than that (i.e., per-symbol versioning)? > > From my point of view, it is. We need to allow changing ABI for some > modules while maintaining it for others. > In fact I think that there should be version not only for every exported > symbol (in the EXPORT_SYMBOL() sense), but also for every public type > (in the sense of eg. structure defined in the public header file). Well the distro can just append _v2, _v3 to the name of the function or type if it has to break compat for some reason. Would that be enough? Thanks, Nick -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
