On Sat, Aug 12, 2023 at 7:36 AM Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> wrote: > > Hi, > > Here is the 3rd version of RFC series to use ftrace_regs instead of pt_regs. > The previous version is here; > > https://lore.kernel.org/all/169139090386.324433.6412259486776991296.stgit@devnote2/ > > This also includes the generic part and minimum modifications of arch > dependent code. (e.g. not including rethook for arm64.) I think that one aspect that's missing from the discussion (and maybe the series) so far is plans to actually save partial registers in the existing rethook trampolines. For now the series makes everything called by the rethook trampolines handle the possibility of having a sparse ftrace_regs but the rethook trampolines still save full ftrace_regs. I think that to rip the full benefits of this series, we should have the rethook trampolines save the equivalent ftrace_regs as the light "args" version of the ftrace trampoline.
