[RFC PATCH v5 28/30] perf record: Load all eBPF object into kernel

[Wang Nan <wangnan0@huawei.com>]

This patch utilizes bpf_load_object() provided by libbpf to load all
objects into kernel.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
 tools/perf/builtin-record.c  | 12 ++++++++++++
 tools/perf/util/bpf-loader.c | 19 +++++++++++++++++++
 tools/perf/util/bpf-loader.h |  2 ++
 3 files changed, 33 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index a7c178e..5ce9d4a 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1121,6 +1121,18 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 		return err;
 	}
 
+	/*
+	 * bpf__probe() also calls symbol__init() if there are probe
+	 * events in bpf objects, so calling symbol_exit when failuer
+	 * is safe. If there is no probe event, bpf__load() always
+	 * success.
+	 */
+	err = bpf__load();
+	if (err) {
+		pr_err("Loading BPF programs failed\n");
+		goto out_symbol_exit;
+	}
+
 	symbol__init(NULL);
 
 	if (symbol_conf.kptr_restrict)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 21470f8..ca6cfa3 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -226,3 +226,22 @@ int bpf__probe(void)
 
 	return err < 0 ? err : 0;
 }
+
+int bpf__load(void)
+{
+	struct bpf_object *obj, *tmp;
+	int err = 0;
+
+	bpf_object__for_each(obj, tmp) {
+		err = bpf_object__load(obj);
+		if (err) {
+			pr_err("bpf: load objects failed\n");
+			goto errout;
+		}
+	}
+	return 0;
+errout:
+	bpf_object__for_each(obj, tmp)
+		bpf_object__unload(obj);
+	return err;
+}
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index eed7bdf..2f0a452 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -14,6 +14,7 @@
 int bpf__prepare_load(const char *filename);
 int bpf__probe(void);
 int bpf__unprobe(void);
+int bpf__load(void);
 
 void bpf__clear(void);
 #else
@@ -25,6 +26,7 @@ static inline int bpf__prepare_load(const char *filename __maybe_unused)
 
 static inline int bpf__probe(void) { return 0; }
 static inline int bpf__unprobe(void) { return 0; }
+static inline int bpf__load(void) { return 0; }
 static inline void bpf__clear(void) { }
 #endif
 #endif
-- 
1.8.3.4