LXR linux/tools/perf/util/bpf_skel/bperf

   1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2// Copyright (c) 2021 Facebook
   3#include <linux/bpf.h>
   4#include <linux/perf_event.h>
   5#include <bpf/bpf_helpers.h>
   6#include <bpf/bpf_tracing.h>
   7#include "bperf.h"
   8#include "bperf_u.h"
   9
  10reading_map diff_readings SEC(".maps");
  11reading_map accum_readings SEC(".maps");
  12
  13struct {
  14        __uint(type, BPF_MAP_TYPE_HASH);
  15        __uint(key_size, sizeof(__u32));
  16        __uint(value_size, sizeof(__u32));
  17} filter SEC(".maps");
  18
  19enum bperf_filter_type type = 0;
  20int enabled = 0;
  21
  22SEC("fexit/XXX")
  23int BPF_PROG(fexit_XXX)
  24{
  25        struct bpf_perf_event_value *diff_val, *accum_val;
  26        __u32 filter_key, zero = 0;
  27        __u32 *accum_key;
  28
  29        if (!enabled)
  30                return 0;
  31
  32        switch (type) {
  33        case BPERF_FILTER_GLOBAL:
  34                accum_key = &zero;
  35                goto do_add;
  36        case BPERF_FILTER_CPU:
  37                filter_key = bpf_get_smp_processor_id();
  38                break;
  39        case BPERF_FILTER_PID:
  40                filter_key = bpf_get_current_pid_tgid() & 0xffffffff;
  41                break;
  42        case BPERF_FILTER_TGID:
  43                filter_key = bpf_get_current_pid_tgid() >> 32;
  44                break;
  45        default:
  46                return 0;
  47        }
  48
  49        accum_key = bpf_map_lookup_elem(&filter, &filter_key);
  50        if (!accum_key)
  51                return 0;
  52
  53do_add:
  54        diff_val = bpf_map_lookup_elem(&diff_readings, &zero);
  55        if (!diff_val)
  56                return 0;
  57
  58        accum_val = bpf_map_lookup_elem(&accum_readings, accum_key);
  59        if (!accum_val)
  60                return 0;
  61
  62        accum_val->counter += diff_val->counter;
  63        accum_val->enabled += diff_val->enabled;
  64        accum_val->running += diff_val->running;
  65
  66        return 0;
  67}
  68
  69char LICENSE[] SEC("license") = "Dual BSD/GPL";
  70