> > Hi Madhavan, > > > >> @@ -245,7 +271,36 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry, > >> fp = thread_saved_fp(task); > >> pc = thread_saved_pc(task); > >> } > >> - unwind(consume_entry, cookie, task, fp, pc); > >> + unwind(consume_entry, cookie, task, fp, pc, false); } > >> + > >> +/* > >> + * arch_stack_walk_reliable() may not be used for livepatch until > >> +all of > >> + * the reliability checks are in place in unwind_consume(). However, > >> + * debug and test code can choose to use it even if all the checks > >> +are not > >> + * in place. > >> + */ > > > > I'm glad to see the long-awaited function :) > > > > Does the above comment mean that this comment will be removed by > > another patch series that about live patch enablement, instead of [PATCH 4/4]? > > > > It seems to take time... But I start thinking about test code. > > > > Yes. This comment will be removed when livepatch will be enabled eventually. > So, AFAICT, there are 4 pieces that are needed: > > - Reliable stack trace in the kernel. I am trying to address that with my patch > series. > > - Mark Rutland's work for making patching safe on ARM64. > > - Objtool (or alternative method) for stack validation. > > - Suraj Jitindar Singh's patch for miscellaneous things needed to enable live patch. > > Once all of these pieces are in place, livepatch can be enabled. > > That said, arch_stack_walk_reliable() can be used for test and debug purposes anytime once this patch series gets accepted. > > Thanks. > > Madhavan Thank you for the information. Keiya
