On Wed, Jun 12, 2019 at 09:10:23AM -0400, Steven Rostedt wrote: > On Tue, 11 Jun 2019 22:05:01 -0500 > Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > > > Right now, ftrace has a special hook in the ORC unwinder > > (orc_ftrace_find). It would be great if we could get rid of that in > > favor of the "always use frame pointers" approach. I'll hold off on > > doing the kpatch/kprobe trampoline conversions in my patches since it > > would conflict with yours. > > Basically, IIUC, what you are saying is that the ftrace trampoline > should always store the %sp in %rb even when CONFIG_FRAME_POINTER is not > enabled? And this can allow you to remove the ftrace specific code from > the orc unwinder? Basically, yes. Though the frame pointer encoding which Peter is adding to the ftrace/kprobes trampolines might complicate things a bit. -- Josh
