use execsnoop-kernel which btf is not requested

execsnoop-kernel/execsnoop_share.cpp

@@ -0,0 +1,83 @@
+
+#include <signal.h>
+#include <bpf/libbpf.h>
+#include <sys/resource.h>
+#include "execsnoop_kern_skel.h"
+#include "execsnoop_share.h"
+
+namespace CGPROXY::EXECSNOOP {
+
+#define PERF_BUFFER_PAGES 64
+#define TASK_COMM_LEN 16
+struct event {
+	char comm[TASK_COMM_LEN];
+	pid_t pid;
+	pid_t tgid;
+	pid_t ppid;
+	uid_t uid;
+};
+
+function<int(int)> callback = NULL;
+promise<void> status;
+
+static void handle_event(void *ctx, int cpu, void *data, __u32 size) {
+  	auto e = static_cast<event*>(data);
+  	if (callback) callback(e->pid);
+}
+
+void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt) {
+	fprintf(stderr, "Lost %llu events on CPU #%d!\n", lost_cnt, cpu);
+}
+
+int bump_memlock_rlimit(void) {
+	struct rlimit rlim_new = { RLIM_INFINITY, RLIM_INFINITY };
+	return setrlimit(RLIMIT_MEMLOCK, &rlim_new);
+}
+
+int execsnoop() {
+	struct perf_buffer_opts pb_opts = {};
+	struct perf_buffer *pb;
+	int err;
+	
+	err = bump_memlock_rlimit();
+	if (err) {
+		fprintf(stderr, "failed to increase rlimit: %d\n", err);
+		return 1;
+	}
+	
+	struct execsnoop_kern *obj=execsnoop_kern__open_and_load();
+	if (!obj) {
+		fprintf(stderr, "failed to open and/or load BPF object\n");
+		return 1;
+	}
+
+	err = execsnoop_kern__attach(obj);
+	if (err) {
+		fprintf(stderr, "failed to attach BPF programs\n");
+		return err;
+	}
+
+	pb_opts.sample_cb = handle_event;
+	pb_opts.lost_cb = handle_lost_events;
+	pb = perf_buffer__new(bpf_map__fd(obj->maps.perf_events), PERF_BUFFER_PAGES, &pb_opts);
+	err = libbpf_get_error(pb);
+	if (err) {
+		printf("failed to setup perf_buffer: %d\n", err);
+		return 1;
+	}
+
+	// notify
+  	status.set_value();
+
+	while ((err = perf_buffer__poll(pb, -1)) >= 0) {}
+	kill(0, SIGINT);
+	return err;
+}
+
+void startThread(function<int(int)> c, promise<void> _status) {
+  status = move(_status);
+  callback = c;
+  execsnoop();
+}
+
+}