xref: /linux-6.15/include/linux/btf_ids.h (revision 66cd9d4e)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef _LINUX_BTF_IDS_H
4 #define _LINUX_BTF_IDS_H
5 
6 struct btf_id_set {
7 	u32 cnt;
8 	u32 ids[];
9 };
10 
11 #ifdef CONFIG_DEBUG_INFO_BTF
12 
13 #include <linux/compiler.h> /* for __PASTE */
14 #include <linux/compiler_attributes.h> /* for __maybe_unused */
15 
16 /*
17  * Following macros help to define lists of BTF IDs placed
18  * in .BTF_ids section. They are initially filled with zeros
19  * (during compilation) and resolved later during the
20  * linking phase by resolve_btfids tool.
21  *
22  * Any change in list layout must be reflected in resolve_btfids
23  * tool logic.
24  */
25 
26 #define BTF_IDS_SECTION ".BTF_ids"
27 
28 #define ____BTF_ID(symbol)				\
29 asm(							\
30 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
31 ".local " #symbol " ;                          \n"	\
32 ".type  " #symbol ", STT_OBJECT;               \n"	\
33 ".size  " #symbol ", 4;                        \n"	\
34 #symbol ":                                     \n"	\
35 ".zero 4                                       \n"	\
36 ".popsection;                                  \n");
37 
38 #define __BTF_ID(symbol) \
39 	____BTF_ID(symbol)
40 
41 #define __ID(prefix) \
42 	__PASTE(prefix, __COUNTER__)
43 
44 /*
45  * The BTF_ID defines unique symbol for each ID pointing
46  * to 4 zero bytes.
47  */
48 #define BTF_ID(prefix, name) \
49 	__BTF_ID(__ID(__BTF_ID__##prefix##__##name##__))
50 
51 /*
52  * The BTF_ID_LIST macro defines pure (unsorted) list
53  * of BTF IDs, with following layout:
54  *
55  * BTF_ID_LIST(list1)
56  * BTF_ID(type1, name1)
57  * BTF_ID(type2, name2)
58  *
59  * list1:
60  * __BTF_ID__type1__name1__1:
61  * .zero 4
62  * __BTF_ID__type2__name2__2:
63  * .zero 4
64  *
65  */
66 #define __BTF_ID_LIST(name, scope)			\
67 asm(							\
68 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
69 "." #scope " " #name ";                        \n"	\
70 #name ":;                                      \n"	\
71 ".popsection;                                  \n");
72 
73 #define BTF_ID_LIST(name)				\
74 __BTF_ID_LIST(name, local)				\
75 extern u32 name[];
76 
77 #define BTF_ID_LIST_GLOBAL(name, n)			\
78 __BTF_ID_LIST(name, globl)
79 
80 /* The BTF_ID_LIST_SINGLE macro defines a BTF_ID_LIST with
81  * a single entry.
82  */
83 #define BTF_ID_LIST_SINGLE(name, prefix, typename)	\
84 	BTF_ID_LIST(name) \
85 	BTF_ID(prefix, typename)
86 #define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) \
87 	BTF_ID_LIST_GLOBAL(name, 1)			  \
88 	BTF_ID(prefix, typename)
89 
90 /*
91  * The BTF_ID_UNUSED macro defines 4 zero bytes.
92  * It's used when we want to define 'unused' entry
93  * in BTF_ID_LIST, like:
94  *
95  *   BTF_ID_LIST(bpf_skb_output_btf_ids)
96  *   BTF_ID(struct, sk_buff)
97  *   BTF_ID_UNUSED
98  *   BTF_ID(struct, task_struct)
99  */
100 
101 #define BTF_ID_UNUSED					\
102 asm(							\
103 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
104 ".zero 4                                       \n"	\
105 ".popsection;                                  \n");
106 
107 /*
108  * The BTF_SET_START/END macros pair defines sorted list of
109  * BTF IDs plus its members count, with following layout:
110  *
111  * BTF_SET_START(list)
112  * BTF_ID(type1, name1)
113  * BTF_ID(type2, name2)
114  * BTF_SET_END(list)
115  *
116  * __BTF_ID__set__list:
117  * .zero 4
118  * list:
119  * __BTF_ID__type1__name1__3:
120  * .zero 4
121  * __BTF_ID__type2__name2__4:
122  * .zero 4
123  *
124  */
125 #define __BTF_SET_START(name, scope)			\
126 asm(							\
127 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
128 "." #scope " __BTF_ID__set__" #name ";         \n"	\
129 "__BTF_ID__set__" #name ":;                    \n"	\
130 ".zero 4                                       \n"	\
131 ".popsection;                                  \n");
132 
133 #define BTF_SET_START(name)				\
134 __BTF_ID_LIST(name, local)				\
135 __BTF_SET_START(name, local)
136 
137 #define BTF_SET_START_GLOBAL(name)			\
138 __BTF_ID_LIST(name, globl)				\
139 __BTF_SET_START(name, globl)
140 
141 #define BTF_SET_END(name)				\
142 asm(							\
143 ".pushsection " BTF_IDS_SECTION ",\"a\";      \n"	\
144 ".size __BTF_ID__set__" #name ", .-" #name "  \n"	\
145 ".popsection;                                 \n");	\
146 extern struct btf_id_set name;
147 
148 #else
149 
150 #define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
151 #define BTF_ID(prefix, name)
152 #define BTF_ID_UNUSED
153 #define BTF_ID_LIST_GLOBAL(name, n) u32 __maybe_unused name[n];
154 #define BTF_ID_LIST_SINGLE(name, prefix, typename) static u32 __maybe_unused name[1];
155 #define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) u32 __maybe_unused name[1];
156 #define BTF_SET_START(name) static struct btf_id_set __maybe_unused name = { 0 };
157 #define BTF_SET_START_GLOBAL(name) static struct btf_id_set __maybe_unused name = { 0 };
158 #define BTF_SET_END(name)
159 
160 #endif /* CONFIG_DEBUG_INFO_BTF */
161 
162 #ifdef CONFIG_NET
163 /* Define a list of socket types which can be the argument for
164  * skc_to_*_sock() helpers. All these sockets should have
165  * sock_common as the first argument in its memory layout.
166  */
167 #define BTF_SOCK_TYPE_xxx \
168 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET, inet_sock)			\
169 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_CONN, inet_connection_sock)	\
170 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_REQ, inet_request_sock)	\
171 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_TW, inet_timewait_sock)	\
172 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_REQ, request_sock)			\
173 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK, sock)				\
174 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK_COMMON, sock_common)		\
175 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP, tcp_sock)			\
176 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_REQ, tcp_request_sock)		\
177 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock)		\
178 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock)			\
179 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock)			\
180 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock)			\
181 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock)
182 
183 enum {
184 #define BTF_SOCK_TYPE(name, str) name,
185 BTF_SOCK_TYPE_xxx
186 #undef BTF_SOCK_TYPE
187 MAX_BTF_SOCK_TYPE,
188 };
189 
190 extern u32 btf_sock_ids[];
191 #endif
192 
193 #define BTF_TRACING_TYPE_xxx	\
194 	BTF_TRACING_TYPE(BTF_TRACING_TYPE_TASK, task_struct)	\
195 	BTF_TRACING_TYPE(BTF_TRACING_TYPE_FILE, file)		\
196 	BTF_TRACING_TYPE(BTF_TRACING_TYPE_VMA, vm_area_struct)
197 
198 enum {
199 #define BTF_TRACING_TYPE(name, type) name,
200 BTF_TRACING_TYPE_xxx
201 #undef BTF_TRACING_TYPE
202 MAX_BTF_TRACING_TYPE,
203 };
204 
205 extern u32 btf_tracing_ids[];
206 
207 #endif
208