bpf-prologue.h

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/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2015, He Kuang <hekuang@huawei.com>
 * Copyright (C) 2015, Huawei Inc.
 */
#ifndef __BPF_PROLOGUE_H
#define __BPF_PROLOGUE_H

#include <linux/compiler.h>
#include <linux/filter.h>
#include "probe-event.h"

#define BPF_PROLOGUE_MAX_ARGS 3
#define BPF_PROLOGUE_START_ARG_REG BPF_REG_3
#define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2

#ifdef HAVE_BPF_PROLOGUE
int bpf__gen_prologue(struct probe_trace_arg *args, int nargs,
              struct bpf_insn *new_prog, size_t *new_cnt,
              size_t cnt_space);
#else
#include <errno.h>

static inline int
bpf__gen_prologue(struct probe_trace_arg *args __maybe_unused,
          int nargs __maybe_unused,
          struct bpf_insn *new_prog __maybe_unused,
          size_t *new_cnt,
          size_t cnt_space __maybe_unused)
{
    if (!new_cnt)
        return -EINVAL;
    *new_cnt = 0;
    return -ENOTSUP;
}
#endif
#endif /* __BPF_PROLOGUE_H */