On Sun, Dec 29, 2019 at 03:37:37PM +0100, Jiri Olsa wrote:
> Adding support to use perf_event_output in
> BPF_TRACE_FENTRY/BPF_TRACE_FEXIT programs.
>
> There are no pt_regs available in the trampoline,
> so getting one via bpf_kfunc_regs array.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> kernel/trace/bpf_trace.c | 67 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 67 insertions(+)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index e5ef4ae9edb5..1b270bbd9016 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1151,6 +1151,69 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> }
> }
>
> +struct bpf_kfunc_regs {
> + struct pt_regs regs[3];
> +};
> +
> +static DEFINE_PER_CPU(struct bpf_kfunc_regs, bpf_kfunc_regs);
> +static DEFINE_PER_CPU(int, bpf_kfunc_nest_level);
Thanks a bunch for working on it.
I don't understand why new regs array and nest level is needed.
Can raw_tp_prog_func_proto() be reused as-is?
Instead of patches 2,3,4 ?
