[PATCH 4/5] bpf: Add bpf_get_stack_kfunc
From: Jiri Olsa <jolsa@kernel.org>
Date: 2019-12-29 14:38:04
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 bpf_get_stack_kfunc in BPF_TRACE_FENTRY/BPF_TRACE_FEXIT programs. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- kernel/trace/bpf_trace.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index c8e0709704f5..02979c5d6357 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c@@ -1229,6 +1229,32 @@ static const struct bpf_func_proto bpf_get_stackid_proto_kfunc = { .arg3_type = ARG_ANYTHING, }; +BPF_CALL_4(bpf_get_stack_kfunc, void*, args, + void *, buf, u32, size, u64, flags) +{ + struct pt_regs *regs = get_bpf_kfunc_regs(); + int ret; + + if (IS_ERR(regs)) + return PTR_ERR(regs); + + perf_fetch_caller_regs(regs); + ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf, + (unsigned long) size, flags, 0); + put_bpf_kfunc_regs(); + return ret; +} + +static const struct bpf_func_proto bpf_get_stack_proto_kfunc = { + .func = bpf_get_stack_raw_tp, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, + .arg4_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * kfunc_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) {
@@ -1237,6 +1263,8 @@ kfunc_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_perf_event_output_proto_kfunc; case BPF_FUNC_get_stackid: return &bpf_get_stackid_proto_kfunc; + case BPF_FUNC_get_stack: + return &bpf_get_stack_proto_kfunc; default: return tracing_func_proto(func_id, prog); }
--
2.21.1