On Wed, 29 May 2019 05:25:21 -0400 Steven Rostedt <rost...@goodmis.org> wrote:
> On Wed, 29 May 2019 15:47:40 +0900 > Masami Hiramatsu <mhira...@kernel.org> wrote: > > > > Hi Steve, > > > > I found that these interfaces seem tightly coupled with fgraph_ops. But that > > cause a problem when I'm using it from kretprobe. > > I was thinking that the kretprobes could use the fgraph_ops like > kprobes uses ftrace_ops. > > > > > kretprobe has 2 handlers, entry handler and return handler, and both need > > pt_regs. But fgraph_ops's entryfunc and retfunc do not pass the pt_regs. > > That is the biggest issue for me on these APIs. > > Can we expand fgraph_ops with regs parameter? > > Ug. Yeah, of course you need that :-/ > > OK, so this series isn't enough to allow kretprobes to use it yet. OK, > I plan on still keeping it because it does allow for placing function > graph tracer into instances with their own filters. OK, that will be a "regs" extension. > > I'll look into adding a REGS flag like we do with ftrace_ops. > > Does the return need all regs? Or is just the return code good enough? Since it depends on arch, I think all regs we need. And for the entry handler, we need all. Thank you, -- Masami Hiramatsu <mhira...@kernel.org>
