Adding support to use bpf_get_stackid_kfunc in
BPF_TRACE_FENTRY/BPF_TRACE_FEXIT programs.
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
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 1b270bbd9016..c8e0709704f5 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1203,12 +1203,40 @@ static const struct bpf_func_proto bpf_perf_event_output_proto_kfunc = {
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
+BPF_CALL_3(bpf_get_stackid_kfunc, void*, args,
+ struct bpf_map *, map, 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);
+ /* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
+ ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
+ flags, 0, 0);
+ put_bpf_kfunc_regs();
+ return ret;
+}
+
+static const struct bpf_func_proto bpf_get_stackid_proto_kfunc = {
+ .func = bpf_get_stackid_kfunc,
+ .gpl_only = true,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_CONST_MAP_PTR,
+ .arg3_type = ARG_ANYTHING,
+};
+
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;
+ case BPF_FUNC_get_stackid:
+ return &bpf_get_stackid_proto_kfunc;
default:
return tracing_func_proto(func_id, prog);
}
--
2.21.1
