On Wed, Apr 24, 2019 at 04:13:59PM -0300, Joao Moreira wrote: > > > Future Work > > > ----------- > > > > > > I don't see an easy way to support multiple homonym <object, name> > > > symbols with unique <position> values in the current livepatch module > > > Elf format. The only solutions that come to mind right now include > > > renaming homonym symbols somehow to retain the relocation->symbol > > > relationship when separate object files are combined. Perhaps an > > > intermediate linker step could make annotated symbols unique in some way > > > to achieve this. /thinking out loud > > > > I'd set this aside for now and we can return to it later. I think it could > > be quite rare in practice. > > > > I was thinking about renaming the symbol too. We can extend the symbol > > naming convention we have now and deal with it in klp_resolve_symbols(), > > but maybe Josh will come up with something clever and cleaner. > > I think this could work well, but (sorry if I understood Joe's idea wrongly) > not as a linker step. Instead of modifying the linker, I think we could > create another tool and plug it into the kbuild pipeline prior to the > livepatch module linking. This way, we would parse the .o elf files, check > for homonyms and rename them based on a convention that is later understood > by klp-convert, as suggested. > > If I am not missing something, this would fix the case where we have > homonyms pointing to the same or different positions, without additional > user intervention other then adding the SYMPOS annotations. > > If you consider this to be useful I can start experiencing. I tend to agree with Miroslav that it's probably ok to ignore this issue for now, as long as klp-convert can detect it and spit out an error. I assume the patch author could work around it with a kallsyms hack. If we encounter it much in the real world then we could figure out a solution at that point. -- Josh
