1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/bpf.h>
 3#include <bpf/bpf_helpers.h>
 4
 5struct __bpf_stdout__ {
 6	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
 7	__type(key, int);
 8	__type(value, __u32);
 9	__uint(max_entries, __NR_CPUS__);
10} __bpf_stdout__ SEC(".maps");
11
12#define puts(from) \
13	({ const int __len = sizeof(from); \
14	   char __from[sizeof(from)] = from;			\
15	   bpf_perf_event_output(args, &__bpf_stdout__, BPF_F_CURRENT_CPU, \
16			  &__from, __len & (sizeof(from) - 1)); })
17
18struct syscall_enter_args;
19
20SEC("raw_syscalls:sys_enter")
21int sys_enter(struct syscall_enter_args *args)
22{
23	puts("Hello, world\n");
24	return 0;
25}
26
27char _license[] SEC("license") = "GPL";