samples/bpf/tracex6_kern.c

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