LXR linux/samples/bpf/tracex6

   1#include <linux/ptrace.h>
   2#include <linux/version.h>
   3#include <uapi/linux/bpf.h>
   4#include <bpf/bpf_helpers.h>
   5
   6struct {
   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
  13struct {
  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
  20struct {
  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
  27SEC("kprobe/htab_map_get_next_key")
  28int 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
  48SEC("kprobe/htab_map_lookup_elem")
  49int 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
  68char _license[] SEC("license") = "GPL";
  69u32 _version SEC("version") = LINUX_VERSION_CODE;
  70