samples/bpf/tracex6_kern.c

   1 #include <linux/ptrace.h>
   2 #include <linux/version.h>
   3 #include <uapi/linux/bpf.h>
   4 #include "bpf_helpers.h"
   5
   6 struct bpf_map_def SEC("maps") counters = {
   7         .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
   8         .key_size = sizeof(int),
   9         .value_size = sizeof(u32),
  10         .max_entries = 64,
  11 };
  12 struct bpf_map_def SEC("maps") values = {
  13         .type = BPF_MAP_TYPE_HASH,
  14         .key_size = sizeof(int),
  15         .value_size = sizeof(u64),
  16         .max_entries = 64,
  17 };
  18 struct bpf_map_def SEC("maps") values2 = {
  19         .type = BPF_MAP_TYPE_HASH,
  20         .key_size = sizeof(int),
  21         .value_size = sizeof(struct bpf_perf_event_value),
  22         .max_entries = 64,
  23 };
  24
  25 SEC("kprobe/htab_map_get_next_key")
  26 int bpf_prog1(struct pt_regs *ctx)
  27 {
  28         u32 key = bpf_get_smp_processor_id();
  29         u64 count, *val;
  30         s64 error;
  31
  32         count = bpf_perf_event_read(&counters, key);
  33         error = (s64)count;
  34         if (error <= -2 && error >= -22)
  35                 return 0;
  36
  37         val = bpf_map_lookup_elem(&values, &key);
  38         if (val)
  39                 *val = count;
  40         else
  41                 bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
  42
  43         return 0;
  44 }
  45
  46 SEC("kprobe/htab_map_lookup_elem")
  47 int bpf_prog2(struct pt_regs *ctx)
  48 {
  49         u32 key = bpf_get_smp_processor_id();
  50         struct bpf_perf_event_value *val, buf;
  51         int error;
  52
  53         error = bpf_perf_event_read_value(&counters, key, &buf, sizeof(buf));
  54         if (error)
  55                 return 0;
  56
  57         val = bpf_map_lookup_elem(&values2, &key);
  58         if (val)
  59                 *val = buf;
  60         else
  61                 bpf_map_update_elem(&values2, &key, &buf, BPF_NOEXIST);
  62
  63         return 0;
  64 }
  65
  66 char _license[] SEC("license") = "GPL";
  67 u32 _version SEC("version") = LINUX_VERSION_CODE;