libbpf: Support sysctl hook

Support BPF_PROG_TYPE_CGROUP_SYSCTL program in libbpf: identifying
program and attach types by section name, probe.
Signed-off-by: NAndrey Ignatov <rdna@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

tools/lib/bpf/libbpf.c

@@ -2064,6 +2064,7 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
 	case BPF_PROG_TYPE_TRACEPOINT:
 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
 	case BPF_PROG_TYPE_PERF_EVENT:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
 		return false;
 	case BPF_PROG_TYPE_KPROBE:
 	default:
@@ -3004,6 +3005,8 @@ static const struct {
 						BPF_CGROUP_UDP4_SENDMSG),
 	BPF_EAPROG_SEC("cgroup/sendmsg6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
 						BPF_CGROUP_UDP6_SENDMSG),
+	BPF_EAPROG_SEC("cgroup/sysctl",		BPF_PROG_TYPE_CGROUP_SYSCTL,
+						BPF_CGROUP_SYSCTL),
 };
 
 #undef BPF_PROG_SEC_IMPL

tools/lib/bpf/libbpf_probes.c

@@ -97,6 +97,7 @@ probe_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns,
 	case BPF_PROG_TYPE_LIRC_MODE2:
 	case BPF_PROG_TYPE_SK_REUSEPORT:
 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
+	case BPF_PROG_TYPE_CGROUP_SYSCTL:
 	default:
 		break;
 	}