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-rw-r--r--include/uapi/linux/btf.h200
1 files changed, 200 insertions, 0 deletions
diff --git a/include/uapi/linux/btf.h b/include/uapi/linux/btf.h
new file mode 100644
index 0000000..426daf5
--- /dev/null
+++ b/include/uapi/linux/btf.h
@@ -0,0 +1,200 @@
+/* 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__ */