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The loading method of the stacktrace_map test case looks too outdated,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 replace control_map with control global
variable.

Signed-off-by: Tao Chen <[email protected]>

Author: Tao Chen

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

@@ -1,75 +1,59 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <test_progs.h>
+#include "stacktrace_map.skel.h"
 
 void test_stacktrace_map(void)
 {
-	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";
-	__u32 key, val, duration = 0;
-	struct bpf_program *prog;
-	struct bpf_object *obj;
-	struct bpf_link *link;
+	struct stacktrace_map *skel;
+	int stackid_hmap_fd, stackmap_fd, stack_amap_fd;
+	int err, stack_trace_len;
+	__u32 duration = 0;
 
-	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");
+	stackid_hmap_fd = bpf_map__fd(skel->maps.stackid_hmap);
 	if (CHECK_FAIL(stackid_hmap_fd < 0))
-		goto disable_pmu;
+		goto out;
 
-	stackmap_fd = bpf_find_map(__func__, obj, "stackmap");
+	stackmap_fd = bpf_map__fd(skel->maps.stackmap);
 	if (CHECK_FAIL(stackmap_fd < 0))
-		goto disable_pmu;
+		goto out;
 
-	stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap");
+	stack_amap_fd = bpf_map__fd(skel->maps.stack_amap);
 	if (CHECK_FAIL(stack_amap_fd < 0))
-		goto disable_pmu;
+		goto out;
 
+	err = stacktrace_map__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto out;
 	/* give some time for bpf program run */
 	sleep(1);
 
 	/* disable stack trace collection */
-	key = 0;
-	val = 1;
-	bpf_map_update_elem(control_map_fd, &key, &val, 0);
+	skel->bss->control = 1;
 
 	/* for every element in stackid_hmap, we can find a corresponding one
 	 * in stackmap, and vice versa.
 	 */
 	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/progs/test_stacktrace_map.c renamed to tools/testing/selftests/bpf/progs/stacktrace_map.c

@@ -8,13 +8,6 @@
 #define PERF_MAX_STACK_DEPTH         127
 #endif
 
-struct {
-	__uint(type, BPF_MAP_TYPE_ARRAY);
-	__uint(max_entries, 1);
-	__type(key, __u32);
-	__type(value, __u32);
-} control_map SEC(".maps");
-
 struct {
 	__uint(type, BPF_MAP_TYPE_HASH);
 	__uint(max_entries, 16384);
@@ -50,16 +43,16 @@ struct sched_switch_args {
 	int next_prio;
 };
 
+int control = 0;
 SEC("tracepoint/sched/sched_switch")
 int oncpu(struct sched_switch_args *ctx)
 {
 	__u32 max_len = PERF_MAX_STACK_DEPTH * sizeof(__u64);
-	__u32 key = 0, val = 0, *value_p;
+	__u32 key = 0, val = 0;
 	void *stack_p;
 
-	value_p = bpf_map_lookup_elem(&control_map, &key);
-	if (value_p && *value_p)
-		return 0; /* skip if non-zero *value_p */
+	if (control)
+		return 0;
 
 	/* The size of stackmap and stackid_hmap should be the same */
 	key = bpf_get_stackid(ctx, &stackmap, 0);