[PATCH 2/6] bpf: Add bpf_perf_event_output_kfunc
From: Jiri Olsa <jolsa@kernel.org>
Date: 2020-01-21 12:05:29
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [security & lsm] (security audit and enforcement using bpf), bpf [tracing], the rest, tracing · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, KP Singh, Matt Bobrowski, Song Liu, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Adding support to use perf_event_output in BPF_TRACE_FENTRY/BPF_TRACE_FEXIT programs. Using nesting regs array from raw tracepoint helpers. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- kernel/trace/bpf_trace.c | 41 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 19e793aa441a..6a18e2ae6e30 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c@@ -1172,6 +1172,43 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) } } +BPF_CALL_5(bpf_perf_event_output_kfunc, void *, ctx, struct bpf_map *, map, + u64, flags, void *, data, u64, size) +{ + struct pt_regs *regs = get_bpf_raw_tp_regs(); + int ret; + + if (IS_ERR(regs)) + return PTR_ERR(regs); + + perf_fetch_caller_regs(regs); + ret = ____bpf_perf_event_output(regs, map, flags, data, size); + put_bpf_raw_tp_regs(); + return ret; +} + +static const struct bpf_func_proto bpf_perf_event_output_proto_kfunc = { + .func = bpf_perf_event_output_kfunc, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_PTR_TO_MEM, + .arg5_type = ARG_CONST_SIZE_OR_ZERO, +}; + +static const struct bpf_func_proto * +kfunc_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +{ + switch (func_id) { + case BPF_FUNC_perf_event_output: + return &bpf_perf_event_output_proto_kfunc; + default: + return tracing_func_proto(func_id, prog); + } +} + static const struct bpf_func_proto * tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) {
@@ -1181,6 +1218,10 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_skb_output_proto; #endif default: + if (prog->expected_attach_type == BPF_TRACE_FENTRY || + prog->expected_attach_type == BPF_TRACE_FEXIT) + return kfunc_prog_func_proto(func_id, prog); + return raw_tp_prog_func_proto(func_id, prog); } }
--
2.24.1