perf test: Add 'perf test BPF'

This patch adds BPF testcase for testing BPF event filtering.

By utilizing the result of 'perf test LLVM', this patch compiles the
eBPF sample program then test its ability. The BPF script in 'perf test
LLVM' lets only 50% samples generated by epoll_pwait() to be captured.
This patch runs that system call for 111 times, so the result should
contain 56 samples.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446817783-86722-8-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index e3afa1b60bb5..4c50411371db 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -34,10 +34,32 @@ struct bpf_prog_priv {
 	struct perf_probe_event pev;
 };
 
+static bool libbpf_initialized;
+
+struct bpf_object *
+bpf__prepare_load_buffer(void *obj_buf, size_t obj_buf_sz, const char *name)
+{
+	struct bpf_object *obj;
+
+	if (!libbpf_initialized) {
+		libbpf_set_print(libbpf_warning,
+				 libbpf_info,
+				 libbpf_debug);
+		libbpf_initialized = true;
+	}
+
+	obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, name);
+	if (IS_ERR(obj)) {
+		pr_debug("bpf: failed to load buffer\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	return obj;
+}
+
 struct bpf_object *bpf__prepare_load(const char *filename, bool source)
 {
 	struct bpf_object *obj;
-	static bool libbpf_initialized;
 
 	if (!libbpf_initialized) {
 		libbpf_set_print(libbpf_warning,