libbpf: Support detecting writable tracepoint program

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4H3JT
CVE: NA

---------------------------

Identify writable tracepoint program by section prefix
raw_tracepoint.w/.

The correct way is back-porting from commit ccaf12d6
("libbpf: Support detecting and attaching of writable tracepoint program"),
but the refactoring of libbpf makes it hard, so using the same section
prefix as ccaf12d6 and post a home-made patch instead.
Signed-off-by: NHou Tao <houtao1@huawei.com>
Reviewed-by: NKuohai Xu <xukuohai@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

tools/lib/bpf/libbpf.c

@@ -2119,6 +2119,7 @@ static const struct {
 	BPF_PROG_SEC("action",		BPF_PROG_TYPE_SCHED_ACT),
 	BPF_PROG_SEC("tracepoint/",	BPF_PROG_TYPE_TRACEPOINT),
 	BPF_PROG_SEC("raw_tracepoint/",	BPF_PROG_TYPE_RAW_TRACEPOINT),
+	BPF_PROG_SEC("raw_tracepoint.w/", BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE),
 	BPF_PROG_SEC("xdp",		BPF_PROG_TYPE_XDP),
 	BPF_PROG_SEC("perf_event",	BPF_PROG_TYPE_PERF_EVENT),
 	BPF_PROG_SEC("cgroup/skb",	BPF_PROG_TYPE_CGROUP_SKB),