On Wed, 9 Mar 2022, Mark Brown wrote: > On Tue, Mar 08, 2022 at 04:00:35PM -0600, Madhavan T. Venkataraman wrote: > > > It is just that patch 11 that defines "select > > HAVE_RELIABLE_STACKTRACE" did not receive any comments from you > > (unless I missed a comment that came from you. That is entirely > > possible. If I missed it, my bad). Since you suggested that change, I > > just wanted to make sure that that patch looks OK to you. > > I think that's more a question for the livepatch people to be honest - > it's not entirely a technical one, there's a bunch of confidence level > stuff going on. For example there was some suggestion that people might > insist on having objtool support, though there's also substantial > pushback on making objtool a requirement for anything from other > quarters. I was hoping that posting that patch would provoke some > discussion about what exactly is needed but that's not happened thus > far. I think everyone will be happy with HAVE_RELIABLE_STACKTRACE on arm64 as long as there is a guarantee that stack traces are really reliable. My understanding is that there is still some work to be done on arm64 arch side (but I may have misunderstood what Mark R. said elsewhere). And yes, then there is a question of objtool. It is one option but not the only one. There have been proposals of implementing guarantees on a compiler side and leaving objtool for x86_64 only (albeit objtool may bring more features to the table... ORC, arch features checking). Madhavan also mentioned that he enhanced objtool and he planned to submit it eventually (https://lore.kernel.org/all/1a0e19db-a7f8-4c8e-0163-398fcd364d54@xxxxxxxxxxxxxxxxxxx/T/#u), so maybe arm64 maintainers could decide on a future direction based on that? Regards Miroslav
