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
  19 SEC("kprobe/htab_map_get_next_key")
  20 int bpf_prog1(struct pt_regs *ctx)
  21 {
  22         u32 key = bpf_get_smp_processor_id();
  23         u64 count, *val;
  24         s64 error;
  25
  26         count = bpf_perf_event_read(&counters, key);
  27         error = (s64)count;
  28         if (error <= -2 && error >= -22)
  29                 return 0;
  30
  31         val = bpf_map_lookup_elem(&values, &key);
  32         if (val)
  33                 *val = count;
  34         else
  35                 bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
  36
  37         return 0;
  38 }
  39
  40 char _license[] SEC("license") = "GPL";
  41 u32 _version SEC("version") = LINUX_VERSION_CODE;