tools/testing/selftests/bpf/progs/trace_printk.c

   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 }