1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2020, Oracle and/or its affiliates.
3 
4 #include "vmlinux.h"
5 #include <bpf/bpf_helpers.h>
6 #include <bpf/bpf_tracing.h>
7 #include "bpf_misc.h"
8 
9 char _license[] SEC("license") = "GPL";
10 
11 int trace_printk_ret = 0;
12 int trace_printk_ran = 0;
13 
14 const char fmt[] = "Testing,testing %d\n";
15 
16 SEC("fentry/" SYS_PREFIX "sys_nanosleep")
sys_enter(void * ctx)17 int sys_enter(void *ctx)
18 {
19 	trace_printk_ret = bpf_trace_printk(fmt, sizeof(fmt),
20 					    ++trace_printk_ran);
21 	return 0;
22 }
23