forked from mirrors/linux
		
	'VAL' should be protected by the brackets.
v2:
* Squash the fix for Documentation/bpf/btf.rst
Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Gary Lin <glin@suse.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
		
	
			
		
			
				
	
	
		
			165 lines
		
	
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			165 lines
		
	
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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/* Copyright (c) 2018 Facebook */
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#ifndef _UAPI__LINUX_BTF_H__
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#define _UAPI__LINUX_BTF_H__
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#include <linux/types.h>
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#define BTF_MAGIC	0xeB9F
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#define BTF_VERSION	1
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struct btf_header {
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	__u16	magic;
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	__u8	version;
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	__u8	flags;
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	__u32	hdr_len;
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	/* All offsets are in bytes relative to the end of this header */
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	__u32	type_off;	/* offset of type section	*/
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	__u32	type_len;	/* length of type section	*/
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	__u32	str_off;	/* offset of string section	*/
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	__u32	str_len;	/* length of string section	*/
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};
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/* Max # of type identifier */
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#define BTF_MAX_TYPE	0x0000ffff
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/* Max offset into the string section */
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#define BTF_MAX_NAME_OFFSET	0x0000ffff
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/* Max # of struct/union/enum members or func args */
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#define BTF_MAX_VLEN	0xffff
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struct btf_type {
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	__u32 name_off;
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	/* "info" bits arrangement
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	 * bits  0-15: vlen (e.g. # of struct's members)
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	 * bits 16-23: unused
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	 * bits 24-27: kind (e.g. int, ptr, array...etc)
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	 * bits 28-30: unused
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	 * bit     31: kind_flag, currently used by
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	 *             struct, union and fwd
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	 */
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	__u32 info;
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	/* "size" is used by INT, ENUM, STRUCT, UNION and DATASEC.
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	 * "size" tells the size of the type it is describing.
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	 *
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	 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
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	 * FUNC, FUNC_PROTO and VAR.
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	 * "type" is a type_id referring to another type.
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	 */
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	union {
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		__u32 size;
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		__u32 type;
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	};
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};
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#define BTF_INFO_KIND(info)	(((info) >> 24) & 0x0f)
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#define BTF_INFO_VLEN(info)	((info) & 0xffff)
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#define BTF_INFO_KFLAG(info)	((info) >> 31)
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#define BTF_KIND_UNKN		0	/* Unknown	*/
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#define BTF_KIND_INT		1	/* Integer	*/
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#define BTF_KIND_PTR		2	/* Pointer	*/
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#define BTF_KIND_ARRAY		3	/* Array	*/
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#define BTF_KIND_STRUCT		4	/* Struct	*/
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#define BTF_KIND_UNION		5	/* Union	*/
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#define BTF_KIND_ENUM		6	/* Enumeration	*/
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#define BTF_KIND_FWD		7	/* Forward	*/
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#define BTF_KIND_TYPEDEF	8	/* Typedef	*/
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#define BTF_KIND_VOLATILE	9	/* Volatile	*/
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#define BTF_KIND_CONST		10	/* Const	*/
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#define BTF_KIND_RESTRICT	11	/* Restrict	*/
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#define BTF_KIND_FUNC		12	/* Function	*/
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#define BTF_KIND_FUNC_PROTO	13	/* Function Proto	*/
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#define BTF_KIND_VAR		14	/* Variable	*/
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#define BTF_KIND_DATASEC	15	/* Section	*/
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#define BTF_KIND_MAX		BTF_KIND_DATASEC
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#define NR_BTF_KINDS		(BTF_KIND_MAX + 1)
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/* For some specific BTF_KIND, "struct btf_type" is immediately
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 * followed by extra data.
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 */
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/* BTF_KIND_INT is followed by a u32 and the following
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 * is the 32 bits arrangement:
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 */
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#define BTF_INT_ENCODING(VAL)	(((VAL) & 0x0f000000) >> 24)
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#define BTF_INT_OFFSET(VAL)	(((VAL) & 0x00ff0000) >> 16)
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#define BTF_INT_BITS(VAL)	((VAL)  & 0x000000ff)
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/* Attributes stored in the BTF_INT_ENCODING */
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#define BTF_INT_SIGNED	(1 << 0)
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#define BTF_INT_CHAR	(1 << 1)
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#define BTF_INT_BOOL	(1 << 2)
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/* BTF_KIND_ENUM is followed by multiple "struct btf_enum".
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 * The exact number of btf_enum is stored in the vlen (of the
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 * info in "struct btf_type").
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 */
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struct btf_enum {
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	__u32	name_off;
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	__s32	val;
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};
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/* BTF_KIND_ARRAY is followed by one "struct btf_array" */
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struct btf_array {
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	__u32	type;
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	__u32	index_type;
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	__u32	nelems;
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};
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/* BTF_KIND_STRUCT and BTF_KIND_UNION are followed
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 * by multiple "struct btf_member".  The exact number
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 * of btf_member is stored in the vlen (of the info in
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 * "struct btf_type").
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 */
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struct btf_member {
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	__u32	name_off;
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	__u32	type;
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	/* If the type info kind_flag is set, the btf_member offset
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	 * contains both member bitfield size and bit offset. The
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	 * bitfield size is set for bitfield members. If the type
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	 * info kind_flag is not set, the offset contains only bit
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	 * offset.
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	 */
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	__u32	offset;
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};
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/* If the struct/union type info kind_flag is set, the
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 * following two macros are used to access bitfield_size
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 * and bit_offset from btf_member.offset.
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 */
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#define BTF_MEMBER_BITFIELD_SIZE(val)	((val) >> 24)
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#define BTF_MEMBER_BIT_OFFSET(val)	((val) & 0xffffff)
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/* BTF_KIND_FUNC_PROTO is followed by multiple "struct btf_param".
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 * The exact number of btf_param is stored in the vlen (of the
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 * info in "struct btf_type").
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 */
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struct btf_param {
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	__u32	name_off;
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	__u32	type;
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};
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enum {
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	BTF_VAR_STATIC = 0,
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	BTF_VAR_GLOBAL_ALLOCATED,
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};
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/* BTF_KIND_VAR is followed by a single "struct btf_var" to describe
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 * additional information related to the variable such as its linkage.
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 */
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struct btf_var {
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	__u32	linkage;
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};
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/* BTF_KIND_DATASEC is followed by multiple "struct btf_var_secinfo"
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 * to describe all BTF_KIND_VAR types it contains along with it's
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 * in-section offset as well as size.
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 */
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struct btf_var_secinfo {
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	__u32	type;
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	__u32	offset;
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	__u32	size;
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};
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#endif /* _UAPI__LINUX_BTF_H__ */
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