selftests/bpf: Refactor stacktrace_map case with skeleton

The loading method of the stacktrace_map test case looks too outdated,
refactor it with skeleton, and we can use global variable feature in
the next patch.

Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250925175030.1615837-2-chen.dylane@linux.dev

Author: Tao Chen

tools/testing/selftests/bpf/prog_tests/stacktrace_map.c

@@ -1,46 +1,26 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <test_progs.h>
+#include "stacktrace_map.skel.h"
 
 void test_stacktrace_map(void)
 {
+	struct stacktrace_map *skel;
 	int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd;
-	const char *prog_name = "oncpu";
-	int err, prog_fd, stack_trace_len;
-	const char *file = "./test_stacktrace_map.bpf.o";
+	int err, stack_trace_len;
 	__u32 key, val, duration = 0;
-	struct bpf_program *prog;
-	struct bpf_object *obj;
-	struct bpf_link *link;
 
-	err = bpf_prog_test_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
-	if (CHECK(err, "prog_load", "err %d errno %d\n", err, errno))
+	skel = stacktrace_map__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
 		return;
 
-	prog = bpf_object__find_program_by_name(obj, prog_name);
-	if (CHECK(!prog, "find_prog", "prog '%s' not found\n", prog_name))
-		goto close_prog;
-
-	link = bpf_program__attach_tracepoint(prog, "sched", "sched_switch");
-	if (!ASSERT_OK_PTR(link, "attach_tp"))
-		goto close_prog;
-
-	/* find map fds */
-	control_map_fd = bpf_find_map(__func__, obj, "control_map");
-	if (CHECK_FAIL(control_map_fd < 0))
-		goto disable_pmu;
-
-	stackid_hmap_fd = bpf_find_map(__func__, obj, "stackid_hmap");
-	if (CHECK_FAIL(stackid_hmap_fd < 0))
-		goto disable_pmu;
-
-	stackmap_fd = bpf_find_map(__func__, obj, "stackmap");
-	if (CHECK_FAIL(stackmap_fd < 0))
-		goto disable_pmu;
-
-	stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap");
-	if (CHECK_FAIL(stack_amap_fd < 0))
-		goto disable_pmu;
+	control_map_fd = bpf_map__fd(skel->maps.control_map);
+	stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap);
+	stackmap_fd = bpf_map__fd(skel->maps.stackmap);
+	stack_amap_fd = bpf_map__fd(skel->maps.stack_amap);
 
+	err = stacktrace_map__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto out;
 	/* give some time for bpf program run */
 	sleep(1);
 
@@ -55,21 +35,19 @@ void test_stacktrace_map(void)
 	err = compare_map_keys(stackid_hmap_fd, stackmap_fd);
 	if (CHECK(err, "compare_map_keys stackid_hmap vs. stackmap",
 		  "err %d errno %d\n", err, errno))
-		goto disable_pmu;
+		goto out;
 
 	err = compare_map_keys(stackmap_fd, stackid_hmap_fd);
 	if (CHECK(err, "compare_map_keys stackmap vs. stackid_hmap",
 		  "err %d errno %d\n", err, errno))
-		goto disable_pmu;
+		goto out;
 
 	stack_trace_len = PERF_MAX_STACK_DEPTH * sizeof(__u64);
 	err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len);
 	if (CHECK(err, "compare_stack_ips stackmap vs. stack_amap",
 		  "err %d errno %d\n", err, errno))
-		goto disable_pmu;
+		goto out;
 
-disable_pmu:
-	bpf_link__destroy(link);
-close_prog:
-	bpf_object__close(obj);
+out:
+	stacktrace_map__destroy(skel);
 }

tools/testing/selftests/bpf/prog_tests/stacktrace_map_raw_tp.c

@@ -5,7 +5,7 @@ void test_stacktrace_map_raw_tp(void)
 {
 	const char *prog_name = "oncpu";
 	int control_map_fd, stackid_hmap_fd, stackmap_fd;
-	const char *file = "./test_stacktrace_map.bpf.o";
+	const char *file = "./stacktrace_map.bpf.o";
 	__u32 key, val, duration = 0;
 	int err, prog_fd;
 	struct bpf_program *prog;