On Sat, Mar 30, 2024 at 10:52 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote: > > On Sat, Mar 30, 2024 at 08:27:55AM -0400, Steven Rostedt wrote: > > On Fri, 29 Mar 2024 16:28:33 -0700 > > Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > > > > I thought I'll just ask instead of digging through code, sorry for > > > being lazy :) Is there any way to pass pt_regs/ftrace_regs captured > > > before function execution to a return probe (fexit/kretprobe)? I.e., > > > how hard is it to pass input function arguments to a kretprobe? That's > > > the biggest advantage of fexit over kretprobe, and if we can make > > > these original pt_regs/ftrace_regs available to kretprobe, then > > > multi-kretprobe will effectively be this multi-fexit. > > > > This should be possible with the updates that Masami is doing with the > > fgraph code. > > yes, I have bpf kprobe-multi link support for that [0] (it's on top of > Masami's fprobe-over-fgraph changes) we discussed that in [1] Sorry, I forgot the regs/args part, mostly remembering we discussed session cookie ideas. Thanks for reminder! > > jirka > > [0] https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git/log/?h=bpf/session_data > [1] https://lore.kernel.org/bpf/20240228090242.4040210-1-jolsa@xxxxxxxxxx/
