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The loading method of the stacktrace_map test case looks too outdated,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

1 files changed, 76 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/stacktrace_map.c b/tools/testing/selftests/bpf/progs/stacktrace_map.c
new file mode 100644
index 000000000000..47568007b668
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/stacktrace_map.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Facebook
+
+#include <vmlinux.h>
+#include <bpf/bpf_helpers.h>
+
+#ifndef PERF_MAX_STACK_DEPTH
+#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);
+	__type(key, __u32);
+	__type(value, __u32);
+} stackid_hmap SEC(".maps");
+
+typedef __u64 stack_trace_t[PERF_MAX_STACK_DEPTH];
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(max_entries, 16384);
+	__type(key, __u32);
+	__type(value, stack_trace_t);
+} stackmap SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 16384);
+	__type(key, __u32);
+	__type(value, stack_trace_t);
+} stack_amap SEC(".maps");
+
+/* taken from /sys/kernel/tracing/events/sched/sched_switch/format */
+struct sched_switch_args {
+	unsigned long long pad;
+	char prev_comm[TASK_COMM_LEN];
+	int prev_pid;
+	int prev_prio;
+	long long prev_state;
+	char next_comm[TASK_COMM_LEN];
+	int next_pid;
+	int next_prio;
+};
+
+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;
+	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 */
+
+	/* The size of stackmap and stackid_hmap should be the same */
+	key = bpf_get_stackid(ctx, &stackmap, 0);
+	if ((int)key >= 0) {
+		bpf_map_update_elem(&stackid_hmap, &key, &val, 0);
+		stack_p = bpf_map_lookup_elem(&stack_amap, &key);
+		if (stack_p)
+			bpf_get_stack(ctx, stack_p, max_len, 0);
+	}
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";