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| 1 | +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
| 2 | +/* Copyright (c) 2018 Facebook */ |
| 3 | +#ifndef _UAPI__LINUX_BTF_H__ |
| 4 | +#define _UAPI__LINUX_BTF_H__ |
| 5 | + |
| 6 | +#include <linux/types.h> |
| 7 | + |
| 8 | +#define BTF_MAGIC 0xeB9F |
| 9 | +#define BTF_VERSION 1 |
| 10 | + |
| 11 | +struct btf_header { |
| 12 | + __u16 magic; |
| 13 | + __u8 version; |
| 14 | + __u8 flags; |
| 15 | + __u32 hdr_len; |
| 16 | + |
| 17 | + /* All offsets are in bytes relative to the end of this header */ |
| 18 | + __u32 type_off; /* offset of type section */ |
| 19 | + __u32 type_len; /* length of type section */ |
| 20 | + __u32 str_off; /* offset of string section */ |
| 21 | + __u32 str_len; /* length of string section */ |
| 22 | +}; |
| 23 | + |
| 24 | +/* Max # of type identifier */ |
| 25 | +#define BTF_MAX_TYPE 0x000fffff |
| 26 | +/* Max offset into the string section */ |
| 27 | +#define BTF_MAX_NAME_OFFSET 0x00ffffff |
| 28 | +/* Max # of struct/union/enum members or func args */ |
| 29 | +#define BTF_MAX_VLEN 0xffff |
| 30 | + |
| 31 | +struct btf_type { |
| 32 | + __u32 name_off; |
| 33 | + /* "info" bits arrangement |
| 34 | + * bits 0-15: vlen (e.g. # of struct's members) |
| 35 | + * bits 16-23: unused |
| 36 | + * bits 24-28: kind (e.g. int, ptr, array...etc) |
| 37 | + * bits 29-30: unused |
| 38 | + * bit 31: kind_flag, currently used by |
| 39 | + * struct, union, enum, fwd and enum64 |
| 40 | + */ |
| 41 | + __u32 info; |
| 42 | + /* "size" is used by INT, ENUM, STRUCT, UNION, DATASEC and ENUM64. |
| 43 | + * "size" tells the size of the type it is describing. |
| 44 | + * |
| 45 | + * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT, |
| 46 | + * FUNC, FUNC_PROTO, VAR, DECL_TAG and TYPE_TAG. |
| 47 | + * "type" is a type_id referring to another type. |
| 48 | + */ |
| 49 | + union { |
| 50 | + __u32 size; |
| 51 | + __u32 type; |
| 52 | + }; |
| 53 | +}; |
| 54 | + |
| 55 | +#define BTF_INFO_KIND(info) (((info) >> 24) & 0x1f) |
| 56 | +#define BTF_INFO_VLEN(info) ((info) & 0xffff) |
| 57 | +#define BTF_INFO_KFLAG(info) ((info) >> 31) |
| 58 | + |
| 59 | +enum { |
| 60 | + BTF_KIND_UNKN = 0, /* Unknown */ |
| 61 | + BTF_KIND_INT = 1, /* Integer */ |
| 62 | + BTF_KIND_PTR = 2, /* Pointer */ |
| 63 | + BTF_KIND_ARRAY = 3, /* Array */ |
| 64 | + BTF_KIND_STRUCT = 4, /* Struct */ |
| 65 | + BTF_KIND_UNION = 5, /* Union */ |
| 66 | + BTF_KIND_ENUM = 6, /* Enumeration up to 32-bit values */ |
| 67 | + BTF_KIND_FWD = 7, /* Forward */ |
| 68 | + BTF_KIND_TYPEDEF = 8, /* Typedef */ |
| 69 | + BTF_KIND_VOLATILE = 9, /* Volatile */ |
| 70 | + BTF_KIND_CONST = 10, /* Const */ |
| 71 | + BTF_KIND_RESTRICT = 11, /* Restrict */ |
| 72 | + BTF_KIND_FUNC = 12, /* Function */ |
| 73 | + BTF_KIND_FUNC_PROTO = 13, /* Function Proto */ |
| 74 | + BTF_KIND_VAR = 14, /* Variable */ |
| 75 | + BTF_KIND_DATASEC = 15, /* Section */ |
| 76 | + BTF_KIND_FLOAT = 16, /* Floating point */ |
| 77 | + BTF_KIND_DECL_TAG = 17, /* Decl Tag */ |
| 78 | + BTF_KIND_TYPE_TAG = 18, /* Type Tag */ |
| 79 | + BTF_KIND_ENUM64 = 19, /* Enumeration up to 64-bit values */ |
| 80 | + |
| 81 | + NR_BTF_KINDS, |
| 82 | + BTF_KIND_MAX = NR_BTF_KINDS - 1, |
| 83 | +}; |
| 84 | + |
| 85 | +/* For some specific BTF_KIND, "struct btf_type" is immediately |
| 86 | + * followed by extra data. |
| 87 | + */ |
| 88 | + |
| 89 | +/* BTF_KIND_INT is followed by a u32 and the following |
| 90 | + * is the 32 bits arrangement: |
| 91 | + */ |
| 92 | +#define BTF_INT_ENCODING(VAL) (((VAL) & 0x0f000000) >> 24) |
| 93 | +#define BTF_INT_OFFSET(VAL) (((VAL) & 0x00ff0000) >> 16) |
| 94 | +#define BTF_INT_BITS(VAL) ((VAL) & 0x000000ff) |
| 95 | + |
| 96 | +/* Attributes stored in the BTF_INT_ENCODING */ |
| 97 | +#define BTF_INT_SIGNED (1 << 0) |
| 98 | +#define BTF_INT_CHAR (1 << 1) |
| 99 | +#define BTF_INT_BOOL (1 << 2) |
| 100 | + |
| 101 | +/* BTF_KIND_ENUM is followed by multiple "struct btf_enum". |
| 102 | + * The exact number of btf_enum is stored in the vlen (of the |
| 103 | + * info in "struct btf_type"). |
| 104 | + */ |
| 105 | +struct btf_enum { |
| 106 | + __u32 name_off; |
| 107 | + __s32 val; |
| 108 | +}; |
| 109 | + |
| 110 | +/* BTF_KIND_ARRAY is followed by one "struct btf_array" */ |
| 111 | +struct btf_array { |
| 112 | + __u32 type; |
| 113 | + __u32 index_type; |
| 114 | + __u32 nelems; |
| 115 | +}; |
| 116 | + |
| 117 | +/* BTF_KIND_STRUCT and BTF_KIND_UNION are followed |
| 118 | + * by multiple "struct btf_member". The exact number |
| 119 | + * of btf_member is stored in the vlen (of the info in |
| 120 | + * "struct btf_type"). |
| 121 | + */ |
| 122 | +struct btf_member { |
| 123 | + __u32 name_off; |
| 124 | + __u32 type; |
| 125 | + /* If the type info kind_flag is set, the btf_member offset |
| 126 | + * contains both member bitfield size and bit offset. The |
| 127 | + * bitfield size is set for bitfield members. If the type |
| 128 | + * info kind_flag is not set, the offset contains only bit |
| 129 | + * offset. |
| 130 | + */ |
| 131 | + __u32 offset; |
| 132 | +}; |
| 133 | + |
| 134 | +/* If the struct/union type info kind_flag is set, the |
| 135 | + * following two macros are used to access bitfield_size |
| 136 | + * and bit_offset from btf_member.offset. |
| 137 | + */ |
| 138 | +#define BTF_MEMBER_BITFIELD_SIZE(val) ((val) >> 24) |
| 139 | +#define BTF_MEMBER_BIT_OFFSET(val) ((val) & 0xffffff) |
| 140 | + |
| 141 | +/* BTF_KIND_FUNC_PROTO is followed by multiple "struct btf_param". |
| 142 | + * The exact number of btf_param is stored in the vlen (of the |
| 143 | + * info in "struct btf_type"). |
| 144 | + */ |
| 145 | +struct btf_param { |
| 146 | + __u32 name_off; |
| 147 | + __u32 type; |
| 148 | +}; |
| 149 | + |
| 150 | +enum { |
| 151 | + BTF_VAR_STATIC = 0, |
| 152 | + BTF_VAR_GLOBAL_ALLOCATED = 1, |
| 153 | + BTF_VAR_GLOBAL_EXTERN = 2, |
| 154 | +}; |
| 155 | + |
| 156 | +enum btf_func_linkage { |
| 157 | + BTF_FUNC_STATIC = 0, |
| 158 | + BTF_FUNC_GLOBAL = 1, |
| 159 | + BTF_FUNC_EXTERN = 2, |
| 160 | +}; |
| 161 | + |
| 162 | +/* BTF_KIND_VAR is followed by a single "struct btf_var" to describe |
| 163 | + * additional information related to the variable such as its linkage. |
| 164 | + */ |
| 165 | +struct btf_var { |
| 166 | + __u32 linkage; |
| 167 | +}; |
| 168 | + |
| 169 | +/* BTF_KIND_DATASEC is followed by multiple "struct btf_var_secinfo" |
| 170 | + * to describe all BTF_KIND_VAR types it contains along with it's |
| 171 | + * in-section offset as well as size. |
| 172 | + */ |
| 173 | +struct btf_var_secinfo { |
| 174 | + __u32 type; |
| 175 | + __u32 offset; |
| 176 | + __u32 size; |
| 177 | +}; |
| 178 | + |
| 179 | +/* BTF_KIND_DECL_TAG is followed by a single "struct btf_decl_tag" to describe |
| 180 | + * additional information related to the tag applied location. |
| 181 | + * If component_idx == -1, the tag is applied to a struct, union, |
| 182 | + * variable or function. Otherwise, it is applied to a struct/union |
| 183 | + * member or a func argument, and component_idx indicates which member |
| 184 | + * or argument (0 ... vlen-1). |
| 185 | + */ |
| 186 | +struct btf_decl_tag { |
| 187 | + __s32 component_idx; |
| 188 | +}; |
| 189 | + |
| 190 | +/* BTF_KIND_ENUM64 is followed by multiple "struct btf_enum64". |
| 191 | + * The exact number of btf_enum64 is stored in the vlen (of the |
| 192 | + * info in "struct btf_type"). |
| 193 | + */ |
| 194 | +struct btf_enum64 { |
| 195 | + __u32 name_off; |
| 196 | + __u32 val_lo32; |
| 197 | + __u32 val_hi32; |
| 198 | +}; |
| 199 | + |
| 200 | +#endif /* _UAPI__LINUX_BTF_H__ */ |
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