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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */2/* Copyright (c) 2018 Facebook */3#ifndef _UAPI__LINUX_BTF_H__4#define _UAPI__LINUX_BTF_H__5 6#include <linux/types.h>7 8#define BTF_MAGIC 0xeB9F9#define BTF_VERSION 110 11struct btf_header {12 __u16 magic;13 __u8 version;14 __u8 flags;15 __u32 hdr_len;16 17 /* All offsets are in bytes relative to the end of this header */18 __u32 type_off; /* offset of type section */19 __u32 type_len; /* length of type section */20 __u32 str_off; /* offset of string section */21 __u32 str_len; /* length of string section */22};23 24/* Max # of type identifier */25#define BTF_MAX_TYPE 0x000fffff26/* Max offset into the string section */27#define BTF_MAX_NAME_OFFSET 0x00ffffff28/* Max # of struct/union/enum members or func args */29#define BTF_MAX_VLEN 0xffff30 31struct btf_type {32 __u32 name_off;33 /* "info" bits arrangement34 * bits 0-15: vlen (e.g. # of struct's members)35 * bits 16-23: unused36 * bits 24-28: kind (e.g. int, ptr, array...etc)37 * bits 29-30: unused38 * bit 31: kind_flag, currently used by39 * struct, union, enum, fwd and enum6440 */41 __u32 info;42 /* "size" is used by INT, ENUM, STRUCT, UNION, DATASEC and ENUM64.43 * "size" tells the size of the type it is describing.44 *45 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,46 * FUNC, FUNC_PROTO, VAR, DECL_TAG and TYPE_TAG.47 * "type" is a type_id referring to another type.48 */49 union {50 __u32 size;51 __u32 type;52 };53};54 55#define BTF_INFO_KIND(info) (((info) >> 24) & 0x1f)56#define BTF_INFO_VLEN(info) ((info) & 0xffff)57#define BTF_INFO_KFLAG(info) ((info) >> 31)58 59enum {60 BTF_KIND_UNKN = 0, /* Unknown */61 BTF_KIND_INT = 1, /* Integer */62 BTF_KIND_PTR = 2, /* Pointer */63 BTF_KIND_ARRAY = 3, /* Array */64 BTF_KIND_STRUCT = 4, /* Struct */65 BTF_KIND_UNION = 5, /* Union */66 BTF_KIND_ENUM = 6, /* Enumeration up to 32-bit values */67 BTF_KIND_FWD = 7, /* Forward */68 BTF_KIND_TYPEDEF = 8, /* Typedef */69 BTF_KIND_VOLATILE = 9, /* Volatile */70 BTF_KIND_CONST = 10, /* Const */71 BTF_KIND_RESTRICT = 11, /* Restrict */72 BTF_KIND_FUNC = 12, /* Function */73 BTF_KIND_FUNC_PROTO = 13, /* Function Proto */74 BTF_KIND_VAR = 14, /* Variable */75 BTF_KIND_DATASEC = 15, /* Section */76 BTF_KIND_FLOAT = 16, /* Floating point */77 BTF_KIND_DECL_TAG = 17, /* Decl Tag */78 BTF_KIND_TYPE_TAG = 18, /* Type Tag */79 BTF_KIND_ENUM64 = 19, /* Enumeration up to 64-bit values */80 81 NR_BTF_KINDS,82 BTF_KIND_MAX = NR_BTF_KINDS - 1,83};84 85/* For some specific BTF_KIND, "struct btf_type" is immediately86 * followed by extra data.87 */88 89/* BTF_KIND_INT is followed by a u32 and the following90 * is the 32 bits arrangement:91 */92#define BTF_INT_ENCODING(VAL) (((VAL) & 0x0f000000) >> 24)93#define BTF_INT_OFFSET(VAL) (((VAL) & 0x00ff0000) >> 16)94#define BTF_INT_BITS(VAL) ((VAL) & 0x000000ff)95 96/* Attributes stored in the BTF_INT_ENCODING */97#define BTF_INT_SIGNED (1 << 0)98#define BTF_INT_CHAR (1 << 1)99#define BTF_INT_BOOL (1 << 2)100 101/* BTF_KIND_ENUM is followed by multiple "struct btf_enum".102 * The exact number of btf_enum is stored in the vlen (of the103 * info in "struct btf_type").104 */105struct btf_enum {106 __u32 name_off;107 __s32 val;108};109 110/* BTF_KIND_ARRAY is followed by one "struct btf_array" */111struct btf_array {112 __u32 type;113 __u32 index_type;114 __u32 nelems;115};116 117/* BTF_KIND_STRUCT and BTF_KIND_UNION are followed118 * by multiple "struct btf_member". The exact number119 * of btf_member is stored in the vlen (of the info in120 * "struct btf_type").121 */122struct btf_member {123 __u32 name_off;124 __u32 type;125 /* If the type info kind_flag is set, the btf_member offset126 * contains both member bitfield size and bit offset. The127 * bitfield size is set for bitfield members. If the type128 * info kind_flag is not set, the offset contains only bit129 * offset.130 */131 __u32 offset;132};133 134/* If the struct/union type info kind_flag is set, the135 * following two macros are used to access bitfield_size136 * and bit_offset from btf_member.offset.137 */138#define BTF_MEMBER_BITFIELD_SIZE(val) ((val) >> 24)139#define BTF_MEMBER_BIT_OFFSET(val) ((val) & 0xffffff)140 141/* BTF_KIND_FUNC_PROTO is followed by multiple "struct btf_param".142 * The exact number of btf_param is stored in the vlen (of the143 * info in "struct btf_type").144 */145struct btf_param {146 __u32 name_off;147 __u32 type;148};149 150enum {151 BTF_VAR_STATIC = 0,152 BTF_VAR_GLOBAL_ALLOCATED = 1,153 BTF_VAR_GLOBAL_EXTERN = 2,154};155 156enum btf_func_linkage {157 BTF_FUNC_STATIC = 0,158 BTF_FUNC_GLOBAL = 1,159 BTF_FUNC_EXTERN = 2,160};161 162/* BTF_KIND_VAR is followed by a single "struct btf_var" to describe163 * additional information related to the variable such as its linkage.164 */165struct btf_var {166 __u32 linkage;167};168 169/* BTF_KIND_DATASEC is followed by multiple "struct btf_var_secinfo"170 * to describe all BTF_KIND_VAR types it contains along with it's171 * in-section offset as well as size.172 */173struct btf_var_secinfo {174 __u32 type;175 __u32 offset;176 __u32 size;177};178 179/* BTF_KIND_DECL_TAG is followed by a single "struct btf_decl_tag" to describe180 * additional information related to the tag applied location.181 * If component_idx == -1, the tag is applied to a struct, union,182 * variable or function. Otherwise, it is applied to a struct/union183 * member or a func argument, and component_idx indicates which member184 * or argument (0 ... vlen-1).185 */186struct btf_decl_tag {187 __s32 component_idx;188};189 190/* BTF_KIND_ENUM64 is followed by multiple "struct btf_enum64".191 * The exact number of btf_enum64 is stored in the vlen (of the192 * info in "struct btf_type").193 */194struct btf_enum64 {195 __u32 name_off;196 __u32 val_lo32;197 __u32 val_hi32;198};199 200#endif /* _UAPI__LINUX_BTF_H__ */201