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 #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         BTF_SOCK_TYPE(BTF_SOCK_TYPE_MPTCP, mptcp_sock)
 183
 184 enum {
 185 #define BTF_SOCK_TYPE(name, str) name,
 186 BTF_SOCK_TYPE_xxx
 187 #undef BTF_SOCK_TYPE
 188 MAX_BTF_SOCK_TYPE,
 189 };
 190
 191 extern u32 btf_sock_ids[];
 192 #endif
 193
 194 #define BTF_TRACING_TYPE_xxx    \
 195         BTF_TRACING_TYPE(BTF_TRACING_TYPE_TASK, task_struct)    \
 196         BTF_TRACING_TYPE(BTF_TRACING_TYPE_FILE, file)           \
 197         BTF_TRACING_TYPE(BTF_TRACING_TYPE_VMA, vm_area_struct)
 198
 199 enum {
 200 #define BTF_TRACING_TYPE(name, type) name,
 201 BTF_TRACING_TYPE_xxx
 202 #undef BTF_TRACING_TYPE
 203 MAX_BTF_TRACING_TYPE,
 204 };
 205
 206 extern u32 btf_tracing_ids[];
 207
 208 #endif