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 { |
12 | __u16 ; |
13 | __u8 ; |
14 | __u8 ; |
15 | __u32 ; |
16 | |
17 | /* All offsets are in bytes relative to the end of this header */ |
18 | __u32 ; /* offset of type section */ |
19 | __u32 ; /* length of type section */ |
20 | __u32 ; /* offset of string section */ |
21 | __u32 ; /* 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__ */ |
201 | |