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 /* SPDX-License-Identifier: GPL-2.0 */
 /* Copyright (c) 2018 Facebook */
 
 #ifndef _LINUX_BTF_H
 #define _LINUX_BTF_H 1
 
 #include <linux/types.h>
 #include <linux/bpfptr.h>
 #include <uapi/linux/btf.h>
 #include <uapi/linux/bpf.h>
 
 #define BTF_TYPE_EMIT(type) ((void)(type *)0)
 #define BTF_TYPE_EMIT_ENUM(enum_val) ((void)enum_val)
 
 /* These need to be macros, as the expressions are used in assembler input */
 #define KF_ACQUIRE  (1 << 0) /* kfunc is an acquire function */
 #define KF_RELEASE  (1 << 1) /* kfunc is a release function */
 #define KF_RET_NULL (1 << 2) /* kfunc returns a pointer that may be NULL */
 #define KF_KPTR_GET (1 << 3) /* kfunc returns reference to a kptr */
 /* Trusted arguments are those which are meant to be referenced arguments with
  * unchanged offset. It is used to enforce that pointers obtained from acquire
  * kfuncs remain unmodified when being passed to helpers taking trusted args.
  *
  * Consider
  *  struct foo {
  *      int data;
  *      struct foo *next;
  *  };
  *
  *  struct bar {
  *      int data;
  *      struct foo f;
  *  };
  *
  *  struct foo *f = alloc_foo(); // Acquire kfunc
  *  struct bar *b = alloc_bar(); // Acquire kfunc
  *
  * If a kfunc set_foo_data() wants to operate only on the allocated object, it
  * will set the KF_TRUSTED_ARGS flag, which will prevent unsafe usage like:
  *
  *  set_foo_data(f, 42);       // Allowed
  *  set_foo_data(f->next, 42); // Rejected, non-referenced pointer
  *  set_foo_data(&f->next, 42);// Rejected, referenced, but wrong type
  *  set_foo_data(&b->f, 42);   // Rejected, referenced, but bad offset
  *
  * In the final case, usually for the purposes of type matching, it is deduced
  * by looking at the type of the member at the offset, but due to the
  * requirement of trusted argument, this deduction will be strict and not done
  * for this case.
  */
 #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer arguments */
 
 struct btf;
 struct btf_member;
 struct btf_type;
 union bpf_attr;
 struct btf_show;
 struct btf_id_set;
 
 struct btf_kfunc_id_set {
     struct module *owner;
     struct btf_id_set8 *set;
 };
 
 struct btf_id_dtor_kfunc {
     u32 btf_id;
     u32 kfunc_btf_id;
 };
 
 typedef void (*btf_dtor_kfunc_t)(void *);
 
 extern const struct file_operations btf_fops;
 
 void btf_get(struct btf *btf);
 void btf_put(struct btf *btf);
 int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr);
 struct btf *btf_get_by_fd(int fd);
 int btf_get_info_by_fd(const struct btf *btf,
                const union bpf_attr *attr,
                union bpf_attr __user *uattr);
 /* Figure out the size of a type_id.  If type_id is a modifier
  * (e.g. const), it will be resolved to find out the type with size.
  *
  * For example:
  * In describing "const void *",  type_id is "const" and "const"
  * refers to "void *".  The return type will be "void *".
  *
  * If type_id is a simple "int", then return type will be "int".
  *
  * @btf: struct btf object
  * @type_id: Find out the size of type_id. The type_id of the return
  *           type is set to *type_id.
  * @ret_size: It can be NULL.  If not NULL, the size of the return
  *            type is set to *ret_size.
  * Return: The btf_type (resolved to another type with size info if needed).
  *         NULL is returned if type_id itself does not have size info
  *         (e.g. void) or it cannot be resolved to another type that
  *         has size info.
  *         *type_id and *ret_size will not be changed in the
  *         NULL return case.
  */
 const struct btf_type *btf_type_id_size(const struct btf *btf,
                     u32 *type_id,
                     u32 *ret_size);
 
 /*
  * Options to control show behaviour.
  *  - BTF_SHOW_COMPACT: no formatting around type information
  *  - BTF_SHOW_NONAME: no struct/union member names/types
  *  - BTF_SHOW_PTR_RAW: show raw (unobfuscated) pointer values;
  *    equivalent to %px.
  *  - BTF_SHOW_ZERO: show zero-valued struct/union members; they
  *    are not displayed by default
  *  - BTF_SHOW_UNSAFE: skip use of bpf_probe_read() to safely read
  *    data before displaying it.
  */
 #define BTF_SHOW_COMPACT    BTF_F_COMPACT
 #define BTF_SHOW_NONAME     BTF_F_NONAME
 #define BTF_SHOW_PTR_RAW    BTF_F_PTR_RAW
 #define BTF_SHOW_ZERO       BTF_F_ZERO
 #define BTF_SHOW_UNSAFE     (1ULL << 4)
 
 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
                struct seq_file *m);
 int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, void *obj,
                 struct seq_file *m, u64 flags);
 
 /*
  * Copy len bytes of string representation of obj of BTF type_id into buf.
  *
  * @btf: struct btf object
  * @type_id: type id of type obj points to
  * @obj: pointer to typed data
  * @buf: buffer to write to
  * @len: maximum length to write to buf
  * @flags: show options (see above)
  *
  * Return: length that would have been/was copied as per snprintf, or
  *     negative error.
  */
 int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
                char *buf, int len, u64 flags);
 
 int btf_get_fd_by_id(u32 id);
 u32 btf_obj_id(const struct btf *btf);
 bool btf_is_kernel(const struct btf *btf);
 bool btf_is_module(const struct btf *btf);
 struct module *btf_try_get_module(const struct btf *btf);
 u32 btf_nr_types(const struct btf *btf);
 bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
                const struct btf_member *m,
                u32 expected_offset, u32 expected_size);
 int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
 int btf_find_timer(const struct btf *btf, const struct btf_type *t);
 struct bpf_map_value_off *btf_parse_kptrs(const struct btf *btf,
                       const struct btf_type *t);
 bool btf_type_is_void(const struct btf_type *t);
 s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
 const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
                            u32 id, u32 *res_id);
 const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
                         u32 id, u32 *res_id);
 const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
                          u32 id, u32 *res_id);
 const struct btf_type *
 btf_resolve_size(const struct btf *btf, const struct btf_type *type,
          u32 *type_size);
 const char *btf_type_str(const struct btf_type *t);
 
 #define for_each_member(i, struct_type, member)         \
     for (i = 0, member = btf_type_member(struct_type);  \
          i < btf_type_vlen(struct_type);            \
          i++, member++)
 
 #define for_each_vsi(i, datasec_type, member)           \
     for (i = 0, member = btf_type_var_secinfo(datasec_type);    \
          i < btf_type_vlen(datasec_type);           \
          i++, member++)
 
 static inline bool btf_type_is_ptr(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
 }
 
 static inline bool btf_type_is_int(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
 }
 
 static inline bool btf_type_is_small_int(const struct btf_type *t)
 {
     return btf_type_is_int(t) && t->size <= sizeof(u64);
 }
 
 static inline bool btf_type_is_enum(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
 }
 
 static inline bool btf_is_any_enum(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM ||
            BTF_INFO_KIND(t->info) == BTF_KIND_ENUM64;
 }
 
 static inline bool btf_kind_core_compat(const struct btf_type *t1,
                     const struct btf_type *t2)
 {
     return BTF_INFO_KIND(t1->info) == BTF_INFO_KIND(t2->info) ||
            (btf_is_any_enum(t1) && btf_is_any_enum(t2));
 }
 
 static inline bool str_is_empty(const char *s)
 {
     return !s || !s[0];
 }
 
 static inline u16 btf_kind(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info);
 }
 
 static inline bool btf_is_enum(const struct btf_type *t)
 {
     return btf_kind(t) == BTF_KIND_ENUM;
 }
 
 static inline bool btf_is_enum64(const struct btf_type *t)
 {
     return btf_kind(t) == BTF_KIND_ENUM64;
 }
 
 static inline u64 btf_enum64_value(const struct btf_enum64 *e)
 {
     return ((u64)e->val_hi32 << 32) | e->val_lo32;
 }
 
 static inline bool btf_is_composite(const struct btf_type *t)
 {
     u16 kind = btf_kind(t);
 
     return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
 }
 
 static inline bool btf_is_array(const struct btf_type *t)
 {
     return btf_kind(t) == BTF_KIND_ARRAY;
 }
 
 static inline bool btf_is_int(const struct btf_type *t)
 {
     return btf_kind(t) == BTF_KIND_INT;
 }
 
 static inline bool btf_is_ptr(const struct btf_type *t)
 {
     return btf_kind(t) == BTF_KIND_PTR;
 }
 
 static inline u8 btf_int_offset(const struct btf_type *t)
 {
     return BTF_INT_OFFSET(*(u32 *)(t + 1));
 }
 
 static inline u8 btf_int_encoding(const struct btf_type *t)
 {
     return BTF_INT_ENCODING(*(u32 *)(t + 1));
 }
 
 static inline bool btf_type_is_scalar(const struct btf_type *t)
 {
     return btf_type_is_int(t) || btf_type_is_enum(t);
 }
 
 static inline bool btf_type_is_typedef(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF;
 }
 
 static inline bool btf_type_is_func(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
 }
 
 static inline bool btf_type_is_func_proto(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
 }
 
 static inline bool btf_type_is_var(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
 }
 
 static inline bool btf_type_is_type_tag(const struct btf_type *t)
 {
     return BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG;
 }
 
 /* union is only a special case of struct:
  * all its offsetof(member) == 0
  */
 static inline bool btf_type_is_struct(const struct btf_type *t)
 {
     u8 kind = BTF_INFO_KIND(t->info);
 
     return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
 }
 
 static inline u16 btf_type_vlen(const struct btf_type *t)
 {
     return BTF_INFO_VLEN(t->info);
 }
 
 static inline u16 btf_vlen(const struct btf_type *t)
 {
     return btf_type_vlen(t);
 }
 
 static inline u16 btf_func_linkage(const struct btf_type *t)
 {
     return BTF_INFO_VLEN(t->info);
 }
 
 static inline bool btf_type_kflag(const struct btf_type *t)
 {
     return BTF_INFO_KFLAG(t->info);
 }
 
 static inline u32 __btf_member_bit_offset(const struct btf_type *struct_type,
                       const struct btf_member *member)
 {
     return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
                        : member->offset;
 }
 
 static inline u32 __btf_member_bitfield_size(const struct btf_type *struct_type,
                          const struct btf_member *member)
 {
     return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
                        : 0;
 }
 
 static inline struct btf_member *btf_members(const struct btf_type *t)
 {
     return (struct btf_member *)(t + 1);
 }
 
 static inline u32 btf_member_bit_offset(const struct btf_type *t, u32 member_idx)
 {
     const struct btf_member *m = btf_members(t) + member_idx;
 
     return __btf_member_bit_offset(t, m);
 }
 
 static inline u32 btf_member_bitfield_size(const struct btf_type *t, u32 member_idx)
 {
     const struct btf_member *m = btf_members(t) + member_idx;
 
     return __btf_member_bitfield_size(t, m);
 }
 
 static inline const struct btf_member *btf_type_member(const struct btf_type *t)
 {
     return (const struct btf_member *)(t + 1);
 }
 
 static inline struct btf_array *btf_array(const struct btf_type *t)
 {
     return (struct btf_array *)(t + 1);
 }
 
 static inline struct btf_enum *btf_enum(const struct btf_type *t)
 {
     return (struct btf_enum *)(t + 1);
 }
 
 static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
 {
     return (struct btf_enum64 *)(t + 1);
 }
 
 static inline const struct btf_var_secinfo *btf_type_var_secinfo(
         const struct btf_type *t)
 {
     return (const struct btf_var_secinfo *)(t + 1);
 }
 
 static inline struct btf_param *btf_params(const struct btf_type *t)
 {
     return (struct btf_param *)(t + 1);
 }
 
 #ifdef CONFIG_BPF_SYSCALL
 struct bpf_prog;
 
 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
 const char *btf_name_by_offset(const struct btf *btf, u32 offset);
 struct btf *btf_parse_vmlinux(void);
 struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
 u32 *btf_kfunc_id_set_contains(const struct btf *btf,
                    enum bpf_prog_type prog_type,
                    u32 kfunc_btf_id);
 int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
                   const struct btf_kfunc_id_set *s);
 s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id);
 int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt,
                 struct module *owner);
 #else
 static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
                             u32 type_id)
 {
     return NULL;
 }
 static inline const char *btf_name_by_offset(const struct btf *btf,
                          u32 offset)
 {
     return NULL;
 }
 static inline u32 *btf_kfunc_id_set_contains(const struct btf *btf,
                          enum bpf_prog_type prog_type,
                          u32 kfunc_btf_id)
 {
     return NULL;
 }
 static inline int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
                         const struct btf_kfunc_id_set *s)
 {
     return 0;
 }
 static inline s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id)
 {
     return -ENOENT;
 }
 static inline int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors,
                           u32 add_cnt, struct module *owner)
 {
     return 0;
 }
 #endif
 
 #endif

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