/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ /* Copyright (c) 2018 Facebook */ #ifndef __LINUX_BTF_H__ #define __LINUX_BTF_H__ #include <linux/types.h> #define BTF_MAGIC 0xeB9F #define BTF_VERSION 1 struct btf_header { __u16 magic; __u8 version; __u8 flags; __u32 hdr_len; /* All offsets are in bytes relative to the end of this header */ __u32 type_off; /* offset of type section */ __u32 type_len; /* length of type section */ __u32 str_off; /* offset of string section */ __u32 str_len; /* length of string section */ }; /* Max # of type identifier */ #define BTF_MAX_TYPE 0x000fffff /* Max offset into the string section */ #define BTF_MAX_NAME_OFFSET 0x00ffffff /* Max # of struct/union/enum members or func args */ #define BTF_MAX_VLEN 0xffff struct btf_type { __u32 name_off; /* "info" bits arrangement * bits 0-15: vlen (e.g. # of struct's members) * bits 16-23: unused * bits 24-28: kind (e.g. int, ptr, array...etc) * bits 29-30: unused * bit 31: kind_flag, currently used by * struct, union, enum, fwd and enum64 */ __u32 info; /* "size" is used by INT, ENUM, STRUCT, UNION, DATASEC and ENUM64. * "size" tells the size of the type it is describing. * * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT, * FUNC, FUNC_PROTO, VAR, DECL_TAG and TYPE_TAG. * "type" is a type_id referring to another type. */ union { __u32 size; __u32 type; }; }; #define BTF_INFO_KIND(info) (((info) >> 24) & 0x1f) #define BTF_INFO_VLEN(info) ((info) & 0xffff) #define BTF_INFO_KFLAG(info) ((info) >> 31) enum { BTF_KIND_UNKN = 0, /* Unknown */ BTF_KIND_INT = 1, /* Integer */ BTF_KIND_PTR = 2, /* Pointer */ BTF_KIND_ARRAY = 3, /* Array */ BTF_KIND_STRUCT = 4, /* Struct */ BTF_KIND_UNION = 5, /* Union */ BTF_KIND_ENUM = 6, /* Enumeration up to 32-bit values */ BTF_KIND_FWD = 7, /* Forward */ BTF_KIND_TYPEDEF = 8, /* Typedef */ BTF_KIND_VOLATILE = 9, /* Volatile */ BTF_KIND_CONST = 10, /* Const */ BTF_KIND_RESTRICT = 11, /* Restrict */ BTF_KIND_FUNC = 12, /* Function */ BTF_KIND_FUNC_PROTO = 13, /* Function Proto */ BTF_KIND_VAR = 14, /* Variable */ BTF_KIND_DATASEC = 15, /* Section */ BTF_KIND_FLOAT = 16, /* Floating point */ BTF_KIND_DECL_TAG = 17, /* Decl Tag */ BTF_KIND_TYPE_TAG = 18, /* Type Tag */ BTF_KIND_ENUM64 = 19, /* Enumeration up to 64-bit values */ NR_BTF_KINDS, BTF_KIND_MAX = NR_BTF_KINDS - 1, }; /* For some specific BTF_KIND, "struct btf_type" is immediately * followed by extra data. */ /* BTF_KIND_INT is followed by a u32 and the following * is the 32 bits arrangement: */ #define BTF_INT_ENCODING(VAL) (((VAL) & 0x0f000000) >> 24) #define BTF_INT_OFFSET(VAL) (((VAL) & 0x00ff0000) >> 16) #define BTF_INT_BITS(VAL) ((VAL) & 0x000000ff) /* Attributes stored in the BTF_INT_ENCODING */ #define BTF_INT_SIGNED (1 << 0) #define BTF_INT_CHAR (1 << 1) #define BTF_INT_BOOL (1 << 2) /* BTF_KIND_ENUM is followed by multiple "struct btf_enum". * The exact number of btf_enum is stored in the vlen (of the * info in "struct btf_type"). */ struct btf_enum { __u32 name_off; __s32 val; }; /* BTF_KIND_ARRAY is followed by one "struct btf_array" */ struct btf_array { __u32 type; __u32 index_type; __u32 nelems; }; /* BTF_KIND_STRUCT and BTF_KIND_UNION are followed * by multiple "struct btf_member". The exact number * of btf_member is stored in the vlen (of the info in * "struct btf_type"). */ struct btf_member { __u32 name_off; __u32 type; /* If the type info kind_flag is set, the btf_member offset * contains both member bitfield size and bit offset. The * bitfield size is set for bitfield members. If the type * info kind_flag is not set, the offset contains only bit * offset. */ __u32 offset; }; /* If the struct/union type info kind_flag is set, the * following two macros are used to access bitfield_size * and bit_offset from btf_member.offset. */ #define BTF_MEMBER_BITFIELD_SIZE(val) ((val) >> 24) #define BTF_MEMBER_BIT_OFFSET(val) ((val) & 0xffffff) /* BTF_KIND_FUNC_PROTO is followed by multiple "struct btf_param". * The exact number of btf_param is stored in the vlen (of the * info in "struct btf_type"). */ struct btf_param { __u32 name_off; __u32 type; }; enum { BTF_VAR_STATIC = 0, BTF_VAR_GLOBAL_ALLOCATED = 1, BTF_VAR_GLOBAL_EXTERN = 2, }; enum btf_func_linkage { BTF_FUNC_STATIC = 0, BTF_FUNC_GLOBAL = 1, BTF_FUNC_EXTERN = 2, }; /* BTF_KIND_VAR is followed by a single "struct btf_var" to describe * additional information related to the variable such as its linkage. */ struct btf_var { __u32 linkage; }; /* BTF_KIND_DATASEC is followed by multiple "struct btf_var_secinfo" * to describe all BTF_KIND_VAR types it contains along with it's * in-section offset as well as size. */ struct btf_var_secinfo { __u32 type; __u32 offset; __u32 size; }; /* BTF_KIND_DECL_TAG is followed by a single "struct btf_decl_tag" to describe * additional information related to the tag applied location. * If component_idx == -1, the tag is applied to a struct, union, * variable or function. Otherwise, it is applied to a struct/union * member or a func argument, and component_idx indicates which member * or argument (0 ... vlen-1). */ struct btf_decl_tag { __s32 component_idx; }; /* BTF_KIND_ENUM64 is followed by multiple "struct btf_enum64". * The exact number of btf_enum64 is stored in the vlen (of the * info in "struct btf_type"). */ struct btf_enum64 { __u32 name_off; __u32 val_lo32; __u32 val_hi32; }; #endif /* __LINUX_BTF_H__ */