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

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2019 Facebook
   3
   4 #include <linux/ptrace.h>
   5 #include <linux/bpf.h>
   6 #include <bpf/bpf_helpers.h>
   7 #include "bpf_trace_helpers.h"
   8
   9 struct {
  10         __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
  11         __uint(key_size, sizeof(int));
  12         __uint(value_size, sizeof(int));
  13 } perf_buf_map SEC(".maps");
  14
  15 SEC("kprobe/sys_nanosleep")
  16 int BPF_KPROBE(handle_sys_nanosleep_entry)
  17 {
  18         int cpu = bpf_get_smp_processor_id();
  19
  20         bpf_perf_event_output(ctx, &perf_buf_map, BPF_F_CURRENT_CPU,
  21                               &cpu, sizeof(cpu));
  22         return 0;
  23 }
  24
  25 char _license[] SEC("license") = "GPL";