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 #ifdef CONFIG_DEBUG_INFO_BTF
   7
   8 #include <linux/compiler.h> /* for __PASTE */
   9
  10 /*
  11  * Following macros help to define lists of BTF IDs placed
  12  * in .BTF_ids section. They are initially filled with zeros
  13  * (during compilation) and resolved later during the
  14  * linking phase by resolve_btfids tool.
  15  *
  16  * Any change in list layout must be reflected in resolve_btfids
  17  * tool logic.
  18  */
  19
  20 #define BTF_IDS_SECTION ".BTF_ids"
  21
  22 #define ____BTF_ID(symbol)                              \
  23 asm(                                                    \
  24 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"      \
  25 ".local " #symbol " ;                          \n"      \
  26 ".type  " #symbol ", STT_OBJECT;               \n"      \
  27 ".size  " #symbol ", 4;                        \n"      \
  28 #symbol ":                                     \n"      \
  29 ".zero 4                                       \n"      \
  30 ".popsection;                                  \n");
  31
  32 #define __BTF_ID(symbol) \
  33         ____BTF_ID(symbol)
  34
  35 #define __ID(prefix) \
  36         __PASTE(prefix, __COUNTER__)
  37
  38 /*
  39  * The BTF_ID defines unique symbol for each ID pointing
  40  * to 4 zero bytes.
  41  */
  42 #define BTF_ID(prefix, name) \
  43         __BTF_ID(__ID(__BTF_ID__##prefix##__##name##__))
  44
  45 /*
  46  * The BTF_ID_LIST macro defines pure (unsorted) list
  47  * of BTF IDs, with following layout:
  48  *
  49  * BTF_ID_LIST(list1)
  50  * BTF_ID(type1, name1)
  51  * BTF_ID(type2, name2)
  52  *
  53  * list1:
  54  * __BTF_ID__type1__name1__1:
  55  * .zero 4
  56  * __BTF_ID__type2__name2__2:
  57  * .zero 4
  58  *
  59  */
  60 #define __BTF_ID_LIST(name, scope)                      \
  61 asm(                                                    \
  62 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"      \
  63 "." #scope " " #name ";                        \n"      \
  64 #name ":;                                      \n"      \
  65 ".popsection;                                  \n");    \
  66
  67 #define BTF_ID_LIST(name)                               \
  68 __BTF_ID_LIST(name, local)                              \
  69 extern u32 name[];
  70
  71 #define BTF_ID_LIST_GLOBAL(name)                        \
  72 __BTF_ID_LIST(name, globl)
  73
  74 /*
  75  * The BTF_ID_UNUSED macro defines 4 zero bytes.
  76  * It's used when we want to define 'unused' entry
  77  * in BTF_ID_LIST, like:
  78  *
  79  *   BTF_ID_LIST(bpf_skb_output_btf_ids)
  80  *   BTF_ID(struct, sk_buff)
  81  *   BTF_ID_UNUSED
  82  *   BTF_ID(struct, task_struct)
  83  */
  84
  85 #define BTF_ID_UNUSED                                   \
  86 asm(                                                    \
  87 ".pushsection " BTF_IDS_SECTION ",\"a\";       \n"      \
  88 ".zero 4                                       \n"      \
  89 ".popsection;                                  \n");
  90
  91 #else
  92
  93 #define BTF_ID_LIST(name) static u32 name[5];
  94 #define BTF_ID(prefix, name)
  95 #define BTF_ID_UNUSED
  96 #define BTF_ID_LIST_GLOBAL(name) u32 name[1];
  97
  98 #endif /* CONFIG_DEBUG_INFO_BTF */
  99
 100 #ifdef CONFIG_NET
 101 /* Define a list of socket types which can be the argument for
 102  * skc_to_*_sock() helpers. All these sockets should have
 103  * sock_common as the first argument in its memory layout.
 104  */
 105 #define BTF_SOCK_TYPE_xxx \
 106         BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET, inet_sock)                    \
 107         BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_CONN, inet_connection_sock)    \
 108         BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_REQ, inet_request_sock)        \
 109         BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_TW, inet_timewait_sock)        \
 110         BTF_SOCK_TYPE(BTF_SOCK_TYPE_REQ, request_sock)                  \
 111         BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK, sock)                         \
 112         BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK_COMMON, sock_common)           \
 113         BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP, tcp_sock)                      \
 114         BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_REQ, tcp_request_sock)          \
 115         BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock)          \
 116         BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock)                    \
 117         BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock)                      \
 118         BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock)
 119
 120 enum {
 121 #define BTF_SOCK_TYPE(name, str) name,
 122 BTF_SOCK_TYPE_xxx
 123 #undef BTF_SOCK_TYPE
 124 MAX_BTF_SOCK_TYPE,
 125 };
 126
 127 extern u32 btf_sock_ids[];
 128 #endif
 129
 130 #endif