xref: /linux/tools/include/linux/btf_ids.h (revision e3b9626f09d429788d929c9b9000a069fcfc056e)
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 
15 /*
16  * Following macros help to define lists of BTF IDs placed
17  * in .BTF_ids section. They are initially filled with zeros
18  * (during compilation) and resolved later during the
19  * linking phase by resolve_btfids tool.
20  *
21  * Any change in list layout must be reflected in resolve_btfids
22  * tool logic.
23  */
24 
25 #define BTF_IDS_SECTION ".BTF_ids"
26 
27 #define ____BTF_ID(symbol)				\
28 asm(							\
29 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
30 ".local " #symbol " ;                          \n"	\
31 ".type  " #symbol ", STT_OBJECT;               \n"	\
32 ".size  " #symbol ", 4;                        \n"	\
33 #symbol ":                                     \n"	\
34 ".zero 4                                       \n"	\
35 ".popsection;                                  \n");
36 
37 #define __BTF_ID(symbol) \
38 	____BTF_ID(symbol)
39 
40 #define __ID(prefix) \
41 	__PASTE(prefix, __COUNTER__)
42 
43 /*
44  * The BTF_ID defines unique symbol for each ID pointing
45  * to 4 zero bytes.
46  */
47 #define BTF_ID(prefix, name) \
48 	__BTF_ID(__ID(__BTF_ID__##prefix##__##name##__))
49 
50 /*
51  * The BTF_ID_LIST macro defines pure (unsorted) list
52  * of BTF IDs, with following layout:
53  *
54  * BTF_ID_LIST(list1)
55  * BTF_ID(type1, name1)
56  * BTF_ID(type2, name2)
57  *
58  * list1:
59  * __BTF_ID__type1__name1__1:
60  * .zero 4
61  * __BTF_ID__type2__name2__2:
62  * .zero 4
63  *
64  */
65 #define __BTF_ID_LIST(name, scope)			\
66 asm(							\
67 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
68 "." #scope " " #name ";                        \n"	\
69 #name ":;                                      \n"	\
70 ".popsection;                                  \n");
71 
72 #define BTF_ID_LIST(name)				\
73 __BTF_ID_LIST(name, local)				\
74 extern u32 name[];
75 
76 #define BTF_ID_LIST_GLOBAL(name)			\
77 __BTF_ID_LIST(name, globl)
78 
79 /*
80  * The BTF_ID_UNUSED macro defines 4 zero bytes.
81  * It's used when we want to define 'unused' entry
82  * in BTF_ID_LIST, like:
83  *
84  *   BTF_ID_LIST(bpf_skb_output_btf_ids)
85  *   BTF_ID(struct, sk_buff)
86  *   BTF_ID_UNUSED
87  *   BTF_ID(struct, task_struct)
88  */
89 
90 #define BTF_ID_UNUSED					\
91 asm(							\
92 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
93 ".zero 4                                       \n"	\
94 ".popsection;                                  \n");
95 
96 /*
97  * The BTF_SET_START/END macros pair defines sorted list of
98  * BTF IDs plus its members count, with following layout:
99  *
100  * BTF_SET_START(list)
101  * BTF_ID(type1, name1)
102  * BTF_ID(type2, name2)
103  * BTF_SET_END(list)
104  *
105  * __BTF_ID__set__list:
106  * .zero 4
107  * list:
108  * __BTF_ID__type1__name1__3:
109  * .zero 4
110  * __BTF_ID__type2__name2__4:
111  * .zero 4
112  *
113  */
114 #define __BTF_SET_START(name, scope)			\
115 asm(							\
116 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
117 "." #scope " __BTF_ID__set__" #name ";         \n"	\
118 "__BTF_ID__set__" #name ":;                    \n"	\
119 ".zero 4                                       \n"	\
120 ".popsection;                                  \n");
121 
122 #define BTF_SET_START(name)				\
123 __BTF_ID_LIST(name, local)				\
124 __BTF_SET_START(name, local)
125 
126 #define BTF_SET_START_GLOBAL(name)			\
127 __BTF_ID_LIST(name, globl)				\
128 __BTF_SET_START(name, globl)
129 
130 #define BTF_SET_END(name)				\
131 asm(							\
132 ".pushsection " BTF_IDS_SECTION ",\"a\";      \n"	\
133 ".size __BTF_ID__set__" #name ", .-" #name "  \n"	\
134 ".popsection;                                 \n");	\
135 extern struct btf_id_set name;
136 
137 #else
138 
139 #define BTF_ID_LIST(name) static u32 name[5];
140 #define BTF_ID(prefix, name)
141 #define BTF_ID_UNUSED
142 #define BTF_ID_LIST_GLOBAL(name) u32 name[1];
143 #define BTF_SET_START(name) static struct btf_id_set name = { 0 };
144 #define BTF_SET_START_GLOBAL(name) static struct btf_id_set name = { 0 };
145 #define BTF_SET_END(name)
146 
147 #endif /* CONFIG_DEBUG_INFO_BTF */
148 
149 #ifdef CONFIG_NET
150 /* Define a list of socket types which can be the argument for
151  * skc_to_*_sock() helpers. All these sockets should have
152  * sock_common as the first argument in its memory layout.
153  */
154 #define BTF_SOCK_TYPE_xxx \
155 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET, inet_sock)			\
156 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_CONN, inet_connection_sock)	\
157 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_REQ, inet_request_sock)	\
158 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_TW, inet_timewait_sock)	\
159 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_REQ, request_sock)			\
160 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK, sock)				\
161 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK_COMMON, sock_common)		\
162 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP, tcp_sock)			\
163 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_REQ, tcp_request_sock)		\
164 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock)		\
165 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock)			\
166 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock)			\
167 	BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock)
168 
169 enum {
170 #define BTF_SOCK_TYPE(name, str) name,
171 BTF_SOCK_TYPE_xxx
172 #undef BTF_SOCK_TYPE
173 MAX_BTF_SOCK_TYPE,
174 };
175 
176 extern u32 btf_sock_ids[];
177 #endif
178 
179 #endif
180