include/linux/btf.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /* Copyright (c) 2018 Facebook */
   3
   4 #ifndef _LINUX_BTF_H
   5 #define _LINUX_BTF_H 1
   6
   7 #include <linux/types.h>
   8
   9 struct btf;
  10 struct btf_type;
  11 union bpf_attr;
  12
  13 extern const struct file_operations btf_fops;
  14
  15 void btf_put(struct btf *btf);
  16 int btf_new_fd(const union bpf_attr *attr);
  17 struct btf *btf_get_by_fd(int fd);
  18 int btf_get_info_by_fd(const struct btf *btf,
  19                        const union bpf_attr *attr,
  20                        union bpf_attr __user *uattr);
  21 /* Figure out the size of a type_id.  If type_id is a modifier
  22  * (e.g. const), it will be resolved to find out the type with size.
  23  *
  24  * For example:
  25  * In describing "const void *",  type_id is "const" and "const"
  26  * refers to "void *".  The return type will be "void *".
  27  *
  28  * If type_id is a simple "int", then return type will be "int".
  29  *
  30  * @btf: struct btf object
  31  * @type_id: Find out the size of type_id. The type_id of the return
  32  *           type is set to *type_id.
  33  * @ret_size: It can be NULL.  If not NULL, the size of the return
  34  *            type is set to *ret_size.
  35  * Return: The btf_type (resolved to another type with size info if needed).
  36  *         NULL is returned if type_id itself does not have size info
  37  *         (e.g. void) or it cannot be resolved to another type that
  38  *         has size info.
  39  *         *type_id and *ret_size will not be changed in the
  40  *         NULL return case.
  41  */
  42 const struct btf_type *btf_type_id_size(const struct btf *btf,
  43                                         u32 *type_id,
  44                                         u32 *ret_size);
  45 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
  46                        struct seq_file *m);
  47 int btf_get_fd_by_id(u32 id);
  48 u32 btf_id(const struct btf *btf);
  49 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
  50 const char *btf_name_by_offset(const struct btf *btf, u32 offset);
  51
  52 #endif