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 */ 35