include/linux/btf_ids.h

   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