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") 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