tools/include/linux/btf_ids.h

Source file repositories/reference/linux-study-clean/tools/include/linux/btf_ids.h

File Facts

System
Linux kernel
Corpus path
tools/include/linux/btf_ids.h
Extension
.h
Size
6110 bytes
Lines
220
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct btf_id_set {
	u32 cnt;
	u32 ids[];
};

struct btf_id_set8 {
	u32 cnt;
	u32 flags;
	struct {
		u32 id;
		u32 flags;
	} pairs[];
};

#ifdef CONFIG_DEBUG_INFO_BTF

#include <linux/compiler.h> /* for __PASTE */

/*
 * Following macros help to define lists of BTF IDs placed
 * in .BTF_ids section. They are initially filled with zeros
 * (during compilation) and resolved later during the
 * linking phase by resolve_btfids tool.
 *
 * Any change in list layout must be reflected in resolve_btfids
 * tool logic.
 */

#define BTF_IDS_SECTION ".BTF_ids"

#define ____BTF_ID(symbol)				\
asm(							\
".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
".local " #symbol " ;                          \n"	\
".type  " #symbol ", STT_OBJECT;               \n"	\
".size  " #symbol ", 4;                        \n"	\
#symbol ":                                     \n"	\
".zero 4                                       \n"	\
".popsection;                                  \n");

#define __BTF_ID(symbol) \
	____BTF_ID(symbol)

#define __ID(prefix) \
	__PASTE(__PASTE(prefix, __COUNTER__), __LINE__)

/*
 * The BTF_ID defines unique symbol for each ID pointing
 * to 4 zero bytes.
 */
#define BTF_ID(prefix, name) \
	__BTF_ID(__ID(__BTF_ID__##prefix##__##name##__))

/*
 * The BTF_ID_LIST macro defines pure (unsorted) list
 * of BTF IDs, with following layout:
 *
 * BTF_ID_LIST(list1)
 * BTF_ID(type1, name1)
 * BTF_ID(type2, name2)
 *
 * list1:
 * __BTF_ID__type1__name1__1:
 * .zero 4
 * __BTF_ID__type2__name2__2:
 * .zero 4
 *
 */
#define __BTF_ID_LIST(name, scope)			\
asm(							\
".pushsection " BTF_IDS_SECTION ",\"a\";       \n"	\
"." #scope " " #name ";                        \n"	\
#name ":;                                      \n"	\
".popsection;                                  \n");

#define BTF_ID_LIST(name)				\
__BTF_ID_LIST(name, local)				\
extern u32 name[];

#define BTF_ID_LIST_GLOBAL(name, n)			\
__BTF_ID_LIST(name, globl)

/* The BTF_ID_LIST_SINGLE macro defines a BTF_ID_LIST with
 * a single entry.
 */
#define BTF_ID_LIST_SINGLE(name, prefix, typename)	\
	BTF_ID_LIST(name) \
	BTF_ID(prefix, typename)
#define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) \
	BTF_ID_LIST_GLOBAL(name, 1)			  \

Annotation

Implementation Notes