tools/perf/util/bpf-prologue.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2015, He Kuang <hekuang@huawei.com>
   4  * Copyright (C) 2015, Huawei Inc.
   5  */
   6 #ifndef __BPF_PROLOGUE_H
   7 #define __BPF_PROLOGUE_H
   8
   9 struct probe_trace_arg;
  10 struct bpf_insn;
  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 #include <linux/compiler.h>
  22 #include <errno.h>
  23
  24 static inline int
  25 bpf__gen_prologue(struct probe_trace_arg *args __maybe_unused,
  26                   int nargs __maybe_unused,
  27                   struct bpf_insn *new_prog __maybe_unused,
  28                   size_t *new_cnt,
  29                   size_t cnt_space __maybe_unused)
  30 {
  31         if (!new_cnt)
  32                 return -EINVAL;
  33         *new_cnt = 0;
  34         return -ENOTSUP;
  35 }
  36 #endif
  37 #endif /* __BPF_PROLOGUE_H */