LXR linux/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
   9struct btf;
  10struct btf_member;
  11struct btf_type;
  12union bpf_attr;
  13
  14extern const struct file_operations btf_fops;
  15
  16void btf_put(struct btf *btf);
  17int btf_new_fd(const union bpf_attr *attr);
  18struct btf *btf_get_by_fd(int fd);
  19int btf_get_info_by_fd(const struct btf *btf,
  20                       const union bpf_attr *attr,
  21                       union bpf_attr __user *uattr);
  22/* Figure out the size of a type_id.  If type_id is a modifier
  23 * (e.g. const), it will be resolved to find out the type with size.
  24 *
  25 * For example:
  26 * In describing "const void *",  type_id is "const" and "const"
  27 * refers to "void *".  The return type will be "void *".
  28 *
  29 * If type_id is a simple "int", then return type will be "int".
  30 *
  31 * @btf: struct btf object
  32 * @type_id: Find out the size of type_id. The type_id of the return
  33 *           type is set to *type_id.
  34 * @ret_size: It can be NULL.  If not NULL, the size of the return
  35 *            type is set to *ret_size.
  36 * Return: The btf_type (resolved to another type with size info if needed).
  37 *         NULL is returned if type_id itself does not have size info
  38 *         (e.g. void) or it cannot be resolved to another type that
  39 *         has size info.
  40 *         *type_id and *ret_size will not be changed in the
  41 *         NULL return case.
  42 */
  43const struct btf_type *btf_type_id_size(const struct btf *btf,
  44                                        u32 *type_id,
  45                                        u32 *ret_size);
  46void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
  47                       struct seq_file *m);
  48int btf_get_fd_by_id(u32 id);
  49u32 btf_id(const struct btf *btf);
  50bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
  51                           const struct btf_member *m,
  52                           u32 expected_offset, u32 expected_size);
  53int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t);
  54bool btf_type_is_void(const struct btf_type *t);
  55
  56#ifdef CONFIG_BPF_SYSCALL
  57const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
  58const char *btf_name_by_offset(const struct btf *btf, u32 offset);
  59#else
  60static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
  61                                                    u32 type_id)
  62{
  63        return NULL;
  64}
  65static inline const char *btf_name_by_offset(const struct btf *btf,
  66                                             u32 offset)
  67{
  68        return NULL;
  69}
  70#endif
  71
  72#endif
  73