LXR linux/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#include <linux/compiler.h>
  10#include <linux/filter.h>
  11#include "probe-event.h"
  12
  13#define BPF_PROLOGUE_MAX_ARGS 3
  14#define BPF_PROLOGUE_START_ARG_REG BPF_REG_3
  15#define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2
  16
  17#ifdef HAVE_BPF_PROLOGUE
  18int bpf__gen_prologue(struct probe_trace_arg *args, int nargs,
  19                      struct bpf_insn *new_prog, size_t *new_cnt,
  20                      size_t cnt_space);
  21#else
  22#include <errno.h>
  23
  24static inline int
  25bpf__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 */
  38