samples/bpf: Stop using bpf_object__find_program_by_title API.

bpf_object__find_program_by_title is going to be deprecated.
Replace use cases of bpf_object__find_program_by_title in samples/bpf/
with bpf_object__for_each_program.
Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211214035931.1148209-3-kuifeng@fb.com

samples/bpf/hbm.c

@@ -120,6 +120,9 @@ static void do_error(char *msg, bool errno_flag)
 
 static int prog_load(char *prog)
 {
+	struct bpf_program *pos;
+	const char *sec_name;
+
 	obj = bpf_object__open_file(prog, NULL);
 	if (libbpf_get_error(obj)) {
 		printf("ERROR: opening BPF object file failed\n");
@@ -132,7 +135,13 @@ static int prog_load(char *prog)
 		goto err;
 	}
 
-	bpf_prog = bpf_object__find_program_by_title(obj, "cgroup_skb/egress");
+	bpf_object__for_each_program(pos, obj) {
+		sec_name = bpf_program__section_name(pos);
+		if (sec_name && !strcmp(sec_name, "cgroup_skb/egress")) {
+			bpf_prog = pos;
+			break;
+		}
+	}
 	if (!bpf_prog) {
 		printf("ERROR: finding a prog in obj file failed\n");
 		goto err;

samples/bpf/xdp_fwd_user.c

@@ -79,7 +79,9 @@ int main(int argc, char **argv)
 		.prog_type	= BPF_PROG_TYPE_XDP,
 	};
 	const char *prog_name = "xdp_fwd";
-	struct bpf_program *prog;
+	struct bpf_program *prog = NULL;
+	struct bpf_program *pos;
+	const char *sec_name;
 	int prog_fd, map_fd = -1;
 	char filename[PATH_MAX];
 	struct bpf_object *obj;
@@ -134,7 +136,13 @@ int main(int argc, char **argv)
 			return 1;
 		}
 
-		prog = bpf_object__find_program_by_title(obj, prog_name);
+		bpf_object__for_each_program(pos, obj) {
+			sec_name = bpf_program__section_name(pos);
+			if (sec_name && !strcmp(sec_name, prog_name)) {
+				prog = pos;
+				break;
+			}
+		}
 		prog_fd = bpf_program__fd(prog);
 		if (prog_fd < 0) {
 			printf("program not found: %s\n", strerror(prog_fd));