1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2015, He Kuang <hekuang@huawei.com>
4*4882a593Smuzhiyun * Copyright (C) 2015, Huawei Inc.
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun #ifndef __BPF_PROLOGUE_H
7*4882a593Smuzhiyun #define __BPF_PROLOGUE_H
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <linux/compiler.h>
10*4882a593Smuzhiyun #include <linux/filter.h>
11*4882a593Smuzhiyun #include "probe-event.h"
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #define BPF_PROLOGUE_MAX_ARGS 3
14*4882a593Smuzhiyun #define BPF_PROLOGUE_START_ARG_REG BPF_REG_3
15*4882a593Smuzhiyun #define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun #ifdef HAVE_BPF_PROLOGUE
18*4882a593Smuzhiyun int bpf__gen_prologue(struct probe_trace_arg *args, int nargs,
19*4882a593Smuzhiyun struct bpf_insn *new_prog, size_t *new_cnt,
20*4882a593Smuzhiyun size_t cnt_space);
21*4882a593Smuzhiyun #else
22*4882a593Smuzhiyun #include <errno.h>
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun 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)25*4882a593Smuzhiyun bpf__gen_prologue(struct probe_trace_arg *args __maybe_unused,
26*4882a593Smuzhiyun int nargs __maybe_unused,
27*4882a593Smuzhiyun struct bpf_insn *new_prog __maybe_unused,
28*4882a593Smuzhiyun size_t *new_cnt,
29*4882a593Smuzhiyun size_t cnt_space __maybe_unused)
30*4882a593Smuzhiyun {
31*4882a593Smuzhiyun if (!new_cnt)
32*4882a593Smuzhiyun return -EINVAL;
33*4882a593Smuzhiyun *new_cnt = 0;
34*4882a593Smuzhiyun return -ENOTSUP;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun #endif
37*4882a593Smuzhiyun #endif /* __BPF_PROLOGUE_H */
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