On Tue, Oct 15, 2019 at 06:27:05PM -0400, Steven Rostedt wrote: > (7) Seventh session, titled "klp-convert and livepatch relocations", was led > by Joe Lawrence. > > Joe started the session with problem statement: accessing non exported / > static > symbols from inside the patch module. One possible workardound is manually via > kallsyms. Second workaround is klp-convert, which actually creates proper > relocations inside the livepatch module from the symbol database during the > final .ko link. > Currently module loader looks for special livepatch relocations and resolves > those during runtime; kernel support for these relocations have so far been > added for x86 only. Special livepatch relocations are supported and processed > also on other architectures. Special quirks/sections are not yet supported. > Plus klp-convert would still be needed even with late module patching update. > vmlinux or modules could have ambiguous static symbols. > > It turns out that the features / bugs below have to be resolved before we > can claim the klp-convert support for relocation complete: > - handle all the corner cases (jump labels, static keys, ...) properly and > have a good regression tests in place
I suppose all the patches in this series-of-series here will make life harder for KLP, static_call() and 2 byte jumps etc.. > - one day we might (or might not) add support for out-of-tree modules > which > need klp-convert > - BFD bug 24456 (multiple relocations to the same .text section)
