tools/perf/util/bpf-prologue.h

   1 /*
   2  * Copyright (C) 2015, He Kuang <hekuang@huawei.com>
   3  * Copyright (C) 2015, Huawei Inc.
   4  */
   5 #ifndef __BPF_PROLOGUE_H
   6 #define __BPF_PROLOGUE_H
   7
   8 #include <linux/compiler.h>
   9 #include <linux/filter.h>
  10 #include "probe-event.h"
  11
  12 #define BPF_PROLOGUE_MAX_ARGS 3
  13 #define BPF_PROLOGUE_START_ARG_REG BPF_REG_3
  14 #define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2
  15
  16 #ifdef HAVE_BPF_PROLOGUE
  17 int bpf__gen_prologue(struct probe_trace_arg *args, int nargs,
  18                       struct bpf_insn *new_prog, size_t *new_cnt,
  19                       size_t cnt_space);
  20 #else
  21 static inline int
  22 bpf__gen_prologue(struct probe_trace_arg *args __maybe_unused,
  23                   int nargs __maybe_unused,
  24                   struct bpf_insn *new_prog __maybe_unused,
  25                   size_t *new_cnt,
  26                   size_t cnt_space __maybe_unused)
  27 {
  28         if (!new_cnt)
  29                 return -EINVAL;
  30         *new_cnt = 0;
  31         return -ENOTSUP;
  32 }
  33 #endif
  34 #endif /* __BPF_PROLOGUE_H */