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_helpers.h"
   7
   8 struct {
   9         __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
  10         __uint(key_size, sizeof(int));
  11         __uint(value_size, sizeof(int));
  12 } perf_buf_map SEC(".maps");
  13
  14 SEC("kprobe/sys_nanosleep")
  15 int handle_sys_nanosleep_entry(struct pt_regs *ctx)
  16 {
  17         int cpu = bpf_get_smp_processor_id();
  18
  19         bpf_perf_event_output(ctx, &perf_buf_map, BPF_F_CURRENT_CPU,
  20                               &cpu, sizeof(cpu));
  21         return 0;
  22 }
  23
  24 char _license[] SEC("license") = "GPL";
  25 __u32 _version SEC("version") = 1;