perf bpf: Save BTF in a rbtree in perf_env

BTF contains information necessary to annotate BPF programs. This patch
saves BTF for BPF programs loaded in the system.

Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: kernel-team@fb.com
Link: http://lkml.kernel.org/r/20190312053051.2690567-9-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 37ee4e2a728a..a4fc52b4ffae 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -34,6 +34,28 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
 	return 0;
 }
 
+static int perf_env__fetch_btf(struct perf_env *env,
+			       u32 btf_id,
+			       struct btf *btf)
+{
+	struct btf_node *node;
+	u32 data_size;
+	const void *data;
+
+	data = btf__get_raw_data(btf, &data_size);
+
+	node = malloc(data_size + sizeof(struct btf_node));
+	if (!node)
+		return -1;
+
+	node->id = btf_id;
+	node->data_size = data_size;
+	memcpy(node->data, data, data_size);
+
+	perf_env__insert_btf(env, node);
+	return 0;
+}
+
 /*
  * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
  * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
@@ -113,6 +135,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 			goto out;
 		}
 		has_btf = true;
+		perf_env__fetch_btf(env, info->btf_id, btf);
 	}
 
 	/* Synthesize PERF_RECORD_KSYMBOL */