/* 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 24-27: kind (e.g. int, ptr, array...etc) * bits 28-31: unused */ __u32 info; /* "size" is used by INT, ENUM, STRUCT and UNION. * "size" tells the size of the type it is describing. * * "type" is used by PTR, TYPEDEF, VOLATILE, CONST and RESTRICT. * "type" is a type_id referring to another type. */ union { __u32 size; __u32 type; }; }; #define BTF_INFO_KIND(info) (((info) >> 24) & 0x0f) #define BTF_INFO_VLEN(info) ((info) & 0xffff) #define BTF_KIND_UNKN 0 /* Unknown */ #define BTF_KIND_INT 1 /* Integer */ #define BTF_KIND_PTR 2 /* Pointer */ #define BTF_KIND_ARRAY 3 /* Array */ #define BTF_KIND_STRUCT 4 /* Struct */ #define BTF_KIND_UNION 5 /* Union */ #define BTF_KIND_ENUM 6 /* Enumeration */ #define BTF_KIND_FWD 7 /* Forward */ #define BTF_KIND_TYPEDEF 8 /* Typedef */ #define BTF_KIND_VOLATILE 9 /* Volatile */ #define BTF_KIND_CONST 10 /* Const */ #define BTF_KIND_RESTRICT 11 /* Restrict */ #define BTF_KIND_MAX 11 #define NR_BTF_KINDS 12 /* 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; __u32 offset; /* offset in bits */ }; #endif /* __LINUX_BTF_H__ */

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