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_member; 11 struct btf_type; 12 union bpf_attr; 13 14 extern const struct file_operations btf_fops; 15 16 void btf_put(struct btf *btf); 17 int btf_new_fd(const union bpf_attr *attr); 18 struct btf *btf_get_by_fd(int fd); 19 int 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 */ 43 const struct btf_type *btf_type_id_size(const struct btf *btf, 44 u32 *type_id, 45 u32 *ret_size); 46 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, 47 struct seq_file *m); 48 int btf_get_fd_by_id(u32 id); 49 u32 btf_id(const struct btf *btf); 50 bool 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); 53 54 #ifdef CONFIG_BPF_SYSCALL 55 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id); 56 const char *btf_name_by_offset(const struct btf *btf, u32 offset); 57 #else 58 static inline const struct btf_type *btf_type_by_id(const struct btf *btf, 59 u32 type_id) 60 { 61 return NULL; 62 } 63 static inline const char *btf_name_by_offset(const struct btf *btf, 64 u32 offset) 65 { 66 return NULL; 67 } 68 #endif 69 70 #endif 71