xref: /linux/include/linux/btf.h (revision d9104cec3e8fe4b458b74709853231385779001f)
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 #include <linux/bpfptr.h>
9 #include <linux/bsearch.h>
10 #include <linux/btf_ids.h>
11 #include <uapi/linux/btf.h>
12 #include <uapi/linux/bpf.h>
13 
14 #define BTF_TYPE_EMIT(type) ((void)(type *)0)
15 #define BTF_TYPE_EMIT_ENUM(enum_val) ((void)enum_val)
16 
17 /* These need to be macros, as the expressions are used in assembler input */
18 #define KF_ACQUIRE	(1 << 0) /* kfunc is an acquire function */
19 #define KF_RELEASE	(1 << 1) /* kfunc is a release function */
20 #define KF_RET_NULL	(1 << 2) /* kfunc returns a pointer that may be NULL */
21 /* Trusted arguments are those which are guaranteed to be valid when passed to
22  * the kfunc. It is used to enforce that pointers obtained from either acquire
23  * kfuncs, or from the main kernel on a tracepoint or struct_ops callback
24  * invocation, remain unmodified when being passed to helpers taking trusted
25  * args.
26  *
27  * Consider, for example, the following new task tracepoint:
28  *
29  *	SEC("tp_btf/task_newtask")
30  *	int BPF_PROG(new_task_tp, struct task_struct *task, u64 clone_flags)
31  *	{
32  *		...
33  *	}
34  *
35  * And the following kfunc:
36  *
37  *	BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
38  *
39  * All invocations to the kfunc must pass the unmodified, unwalked task:
40  *
41  *	bpf_task_acquire(task);		    // Allowed
42  *	bpf_task_acquire(task->last_wakee); // Rejected, walked task
43  *
44  * Programs may also pass referenced tasks directly to the kfunc:
45  *
46  *	struct task_struct *acquired;
47  *
48  *	acquired = bpf_task_acquire(task);	// Allowed, same as above
49  *	bpf_task_acquire(acquired);		// Allowed
50  *	bpf_task_acquire(task);			// Allowed
51  *	bpf_task_acquire(acquired->last_wakee); // Rejected, walked task
52  *
53  * Programs may _not_, however, pass a task from an arbitrary fentry/fexit, or
54  * kprobe/kretprobe to the kfunc, as BPF cannot guarantee that all of these
55  * pointers are guaranteed to be safe. For example, the following BPF program
56  * would be rejected:
57  *
58  * SEC("kretprobe/free_task")
59  * int BPF_PROG(free_task_probe, struct task_struct *tsk)
60  * {
61  *	struct task_struct *acquired;
62  *
63  *	acquired = bpf_task_acquire(acquired); // Rejected, not a trusted pointer
64  *	bpf_task_release(acquired);
65  *
66  *	return 0;
67  * }
68  */
69 #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer arguments */
70 #define KF_SLEEPABLE    (1 << 5) /* kfunc may sleep */
71 #define KF_DESTRUCTIVE  (1 << 6) /* kfunc performs destructive actions */
72 #define KF_RCU          (1 << 7) /* kfunc takes either rcu or trusted pointer arguments */
73 /* only one of KF_ITER_{NEW,NEXT,DESTROY} could be specified per kfunc */
74 #define KF_ITER_NEW     (1 << 8) /* kfunc implements BPF iter constructor */
75 #define KF_ITER_NEXT    (1 << 9) /* kfunc implements BPF iter next method */
76 #define KF_ITER_DESTROY (1 << 10) /* kfunc implements BPF iter destructor */
77 #define KF_RCU_PROTECTED (1 << 11) /* kfunc should be protected by rcu cs when they are invoked */
78 #define KF_FASTCALL     (1 << 12) /* kfunc supports bpf_fastcall protocol */
79 #define KF_ARENA_RET    (1 << 13) /* kfunc returns an arena pointer */
80 #define KF_ARENA_ARG1   (1 << 14) /* kfunc takes an arena pointer as its first argument */
81 #define KF_ARENA_ARG2   (1 << 15) /* kfunc takes an arena pointer as its second argument */
82 
83 /*
84  * Tag marking a kernel function as a kfunc. This is meant to minimize the
85  * amount of copy-paste that kfunc authors have to include for correctness so
86  * as to avoid issues such as the compiler inlining or eliding either a static
87  * kfunc, or a global kfunc in an LTO build.
88  */
89 #define __bpf_kfunc __used __retain noinline
90 
91 #define __bpf_kfunc_start_defs()					       \
92 	__diag_push();							       \
93 	__diag_ignore_all("-Wmissing-declarations",			       \
94 			  "Global kfuncs as their definitions will be in BTF");\
95 	__diag_ignore_all("-Wmissing-prototypes",			       \
96 			  "Global kfuncs as their definitions will be in BTF")
97 
98 #define __bpf_kfunc_end_defs() __diag_pop()
99 #define __bpf_hook_start() __bpf_kfunc_start_defs()
100 #define __bpf_hook_end() __bpf_kfunc_end_defs()
101 
102 /*
103  * Return the name of the passed struct, if exists, or halt the build if for
104  * example the structure gets renamed. In this way, developers have to revisit
105  * the code using that structure name, and update it accordingly.
106  */
107 #define stringify_struct(x)			\
108 	({ BUILD_BUG_ON(sizeof(struct x) < 0);	\
109 	   __stringify(x); })
110 
111 struct btf;
112 struct btf_member;
113 struct btf_type;
114 union bpf_attr;
115 struct btf_show;
116 struct btf_id_set;
117 struct bpf_prog;
118 
119 typedef int (*btf_kfunc_filter_t)(const struct bpf_prog *prog, u32 kfunc_id);
120 
121 struct btf_kfunc_id_set {
122 	struct module *owner;
123 	struct btf_id_set8 *set;
124 	btf_kfunc_filter_t filter;
125 };
126 
127 struct btf_id_dtor_kfunc {
128 	u32 btf_id;
129 	u32 kfunc_btf_id;
130 };
131 
132 struct btf_struct_meta {
133 	u32 btf_id;
134 	struct btf_record *record;
135 };
136 
137 struct btf_struct_metas {
138 	u32 cnt;
139 	struct btf_struct_meta types[];
140 };
141 
142 extern const struct file_operations btf_fops;
143 
144 const char *btf_get_name(const struct btf *btf);
145 void btf_get(struct btf *btf);
146 void btf_put(struct btf *btf);
147 const struct btf_header *btf_header(const struct btf *btf);
148 int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_sz);
149 struct btf *btf_get_by_fd(int fd);
150 int btf_get_info_by_fd(const struct btf *btf,
151 		       const union bpf_attr *attr,
152 		       union bpf_attr __user *uattr);
153 /* Figure out the size of a type_id.  If type_id is a modifier
154  * (e.g. const), it will be resolved to find out the type with size.
155  *
156  * For example:
157  * In describing "const void *",  type_id is "const" and "const"
158  * refers to "void *".  The return type will be "void *".
159  *
160  * If type_id is a simple "int", then return type will be "int".
161  *
162  * @btf: struct btf object
163  * @type_id: Find out the size of type_id. The type_id of the return
164  *           type is set to *type_id.
165  * @ret_size: It can be NULL.  If not NULL, the size of the return
166  *            type is set to *ret_size.
167  * Return: The btf_type (resolved to another type with size info if needed).
168  *         NULL is returned if type_id itself does not have size info
169  *         (e.g. void) or it cannot be resolved to another type that
170  *         has size info.
171  *         *type_id and *ret_size will not be changed in the
172  *         NULL return case.
173  */
174 const struct btf_type *btf_type_id_size(const struct btf *btf,
175 					u32 *type_id,
176 					u32 *ret_size);
177 
178 /*
179  * Options to control show behaviour.
180  *	- BTF_SHOW_COMPACT: no formatting around type information
181  *	- BTF_SHOW_NONAME: no struct/union member names/types
182  *	- BTF_SHOW_PTR_RAW: show raw (unobfuscated) pointer values;
183  *	  equivalent to %px.
184  *	- BTF_SHOW_ZERO: show zero-valued struct/union members; they
185  *	  are not displayed by default
186  *	- BTF_SHOW_UNSAFE: skip use of bpf_probe_read() to safely read
187  *	  data before displaying it.
188  */
189 #define BTF_SHOW_COMPACT	BTF_F_COMPACT
190 #define BTF_SHOW_NONAME		BTF_F_NONAME
191 #define BTF_SHOW_PTR_RAW	BTF_F_PTR_RAW
192 #define BTF_SHOW_ZERO		BTF_F_ZERO
193 #define BTF_SHOW_UNSAFE		(1ULL << 4)
194 
195 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
196 		       struct seq_file *m);
197 int btf_type_seq_show_flags(const struct btf *btf, u32 type_id, void *obj,
198 			    struct seq_file *m, u64 flags);
199 
200 /*
201  * Copy len bytes of string representation of obj of BTF type_id into buf.
202  *
203  * @btf: struct btf object
204  * @type_id: type id of type obj points to
205  * @obj: pointer to typed data
206  * @buf: buffer to write to
207  * @len: maximum length to write to buf
208  * @flags: show options (see above)
209  *
210  * Return: length that would have been/was copied as per snprintf, or
211  *	   negative error.
212  */
213 int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
214 			   char *buf, int len, u64 flags);
215 
216 int btf_get_fd_by_id(u32 id);
217 u32 btf_obj_id(const struct btf *btf);
218 bool btf_is_kernel(const struct btf *btf);
219 bool btf_is_module(const struct btf *btf);
220 bool btf_is_vmlinux(const struct btf *btf);
221 struct module *btf_try_get_module(const struct btf *btf);
222 u32 btf_nr_types(const struct btf *btf);
223 struct btf *btf_base_btf(const struct btf *btf);
224 bool btf_type_is_i32(const struct btf_type *t);
225 bool btf_type_is_i64(const struct btf_type *t);
226 bool btf_type_is_primitive(const struct btf_type *t);
227 bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
228 			   const struct btf_member *m,
229 			   u32 expected_offset, u32 expected_size);
230 struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
231 				    u32 field_mask, u32 value_size);
232 int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec);
233 bool btf_type_is_void(const struct btf_type *t);
234 s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
235 s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p);
236 const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
237 					       u32 id, u32 *res_id);
238 const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
239 					    u32 id, u32 *res_id);
240 const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
241 						 u32 id, u32 *res_id);
242 const struct btf_type *
243 btf_resolve_size(const struct btf *btf, const struct btf_type *type,
244 		 u32 *type_size);
245 const char *btf_type_str(const struct btf_type *t);
246 
247 #define for_each_member(i, struct_type, member)			\
248 	for (i = 0, member = btf_type_member(struct_type);	\
249 	     i < btf_type_vlen(struct_type);			\
250 	     i++, member++)
251 
252 #define for_each_vsi(i, datasec_type, member)			\
253 	for (i = 0, member = btf_type_var_secinfo(datasec_type);	\
254 	     i < btf_type_vlen(datasec_type);			\
255 	     i++, member++)
256 
btf_type_is_ptr(const struct btf_type * t)257 static inline bool btf_type_is_ptr(const struct btf_type *t)
258 {
259 	return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
260 }
261 
btf_type_is_int(const struct btf_type * t)262 static inline bool btf_type_is_int(const struct btf_type *t)
263 {
264 	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
265 }
266 
btf_type_is_small_int(const struct btf_type * t)267 static inline bool btf_type_is_small_int(const struct btf_type *t)
268 {
269 	return btf_type_is_int(t) && t->size <= sizeof(u64);
270 }
271 
btf_int_encoding(const struct btf_type * t)272 static inline u8 btf_int_encoding(const struct btf_type *t)
273 {
274 	return BTF_INT_ENCODING(*(u32 *)(t + 1));
275 }
276 
btf_type_is_signed_int(const struct btf_type * t)277 static inline bool btf_type_is_signed_int(const struct btf_type *t)
278 {
279 	return btf_type_is_int(t) && (btf_int_encoding(t) & BTF_INT_SIGNED);
280 }
281 
btf_type_is_enum(const struct btf_type * t)282 static inline bool btf_type_is_enum(const struct btf_type *t)
283 {
284 	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM;
285 }
286 
btf_is_any_enum(const struct btf_type * t)287 static inline bool btf_is_any_enum(const struct btf_type *t)
288 {
289 	return BTF_INFO_KIND(t->info) == BTF_KIND_ENUM ||
290 	       BTF_INFO_KIND(t->info) == BTF_KIND_ENUM64;
291 }
292 
btf_kind_core_compat(const struct btf_type * t1,const struct btf_type * t2)293 static inline bool btf_kind_core_compat(const struct btf_type *t1,
294 					const struct btf_type *t2)
295 {
296 	return BTF_INFO_KIND(t1->info) == BTF_INFO_KIND(t2->info) ||
297 	       (btf_is_any_enum(t1) && btf_is_any_enum(t2));
298 }
299 
str_is_empty(const char * s)300 static inline bool str_is_empty(const char *s)
301 {
302 	return !s || !s[0];
303 }
304 
btf_kind(const struct btf_type * t)305 static inline u16 btf_kind(const struct btf_type *t)
306 {
307 	return BTF_INFO_KIND(t->info);
308 }
309 
btf_is_enum(const struct btf_type * t)310 static inline bool btf_is_enum(const struct btf_type *t)
311 {
312 	return btf_kind(t) == BTF_KIND_ENUM;
313 }
314 
btf_is_enum64(const struct btf_type * t)315 static inline bool btf_is_enum64(const struct btf_type *t)
316 {
317 	return btf_kind(t) == BTF_KIND_ENUM64;
318 }
319 
btf_enum64_value(const struct btf_enum64 * e)320 static inline u64 btf_enum64_value(const struct btf_enum64 *e)
321 {
322 	return ((u64)e->val_hi32 << 32) | e->val_lo32;
323 }
324 
btf_is_composite(const struct btf_type * t)325 static inline bool btf_is_composite(const struct btf_type *t)
326 {
327 	u16 kind = btf_kind(t);
328 
329 	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
330 }
331 
btf_is_array(const struct btf_type * t)332 static inline bool btf_is_array(const struct btf_type *t)
333 {
334 	return btf_kind(t) == BTF_KIND_ARRAY;
335 }
336 
btf_is_int(const struct btf_type * t)337 static inline bool btf_is_int(const struct btf_type *t)
338 {
339 	return btf_kind(t) == BTF_KIND_INT;
340 }
341 
btf_is_ptr(const struct btf_type * t)342 static inline bool btf_is_ptr(const struct btf_type *t)
343 {
344 	return btf_kind(t) == BTF_KIND_PTR;
345 }
346 
btf_int_offset(const struct btf_type * t)347 static inline u8 btf_int_offset(const struct btf_type *t)
348 {
349 	return BTF_INT_OFFSET(*(u32 *)(t + 1));
350 }
351 
btf_int_bits(const struct btf_type * t)352 static inline __u8 btf_int_bits(const struct btf_type *t)
353 {
354 	return BTF_INT_BITS(*(__u32 *)(t + 1));
355 }
356 
btf_type_is_scalar(const struct btf_type * t)357 static inline bool btf_type_is_scalar(const struct btf_type *t)
358 {
359 	return btf_type_is_int(t) || btf_type_is_enum(t);
360 }
361 
btf_type_is_fwd(const struct btf_type * t)362 static inline bool btf_type_is_fwd(const struct btf_type *t)
363 {
364 	return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
365 }
366 
btf_type_is_typedef(const struct btf_type * t)367 static inline bool btf_type_is_typedef(const struct btf_type *t)
368 {
369 	return BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF;
370 }
371 
btf_type_is_volatile(const struct btf_type * t)372 static inline bool btf_type_is_volatile(const struct btf_type *t)
373 {
374 	return BTF_INFO_KIND(t->info) == BTF_KIND_VOLATILE;
375 }
376 
btf_type_is_func(const struct btf_type * t)377 static inline bool btf_type_is_func(const struct btf_type *t)
378 {
379 	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
380 }
381 
btf_type_is_func_proto(const struct btf_type * t)382 static inline bool btf_type_is_func_proto(const struct btf_type *t)
383 {
384 	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
385 }
386 
btf_type_is_var(const struct btf_type * t)387 static inline bool btf_type_is_var(const struct btf_type *t)
388 {
389 	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
390 }
391 
btf_type_is_type_tag(const struct btf_type * t)392 static inline bool btf_type_is_type_tag(const struct btf_type *t)
393 {
394 	return BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG;
395 }
396 
397 /* union is only a special case of struct:
398  * all its offsetof(member) == 0
399  */
btf_type_is_struct(const struct btf_type * t)400 static inline bool btf_type_is_struct(const struct btf_type *t)
401 {
402 	u8 kind = BTF_INFO_KIND(t->info);
403 
404 	return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION;
405 }
406 
__btf_type_is_struct(const struct btf_type * t)407 static inline bool __btf_type_is_struct(const struct btf_type *t)
408 {
409 	return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT;
410 }
411 
btf_type_is_array(const struct btf_type * t)412 static inline bool btf_type_is_array(const struct btf_type *t)
413 {
414 	return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
415 }
416 
btf_type_vlen(const struct btf_type * t)417 static inline u16 btf_type_vlen(const struct btf_type *t)
418 {
419 	return BTF_INFO_VLEN(t->info);
420 }
421 
btf_vlen(const struct btf_type * t)422 static inline u16 btf_vlen(const struct btf_type *t)
423 {
424 	return btf_type_vlen(t);
425 }
426 
btf_func_linkage(const struct btf_type * t)427 static inline u16 btf_func_linkage(const struct btf_type *t)
428 {
429 	return BTF_INFO_VLEN(t->info);
430 }
431 
btf_type_kflag(const struct btf_type * t)432 static inline bool btf_type_kflag(const struct btf_type *t)
433 {
434 	return BTF_INFO_KFLAG(t->info);
435 }
436 
__btf_member_bit_offset(const struct btf_type * struct_type,const struct btf_member * member)437 static inline u32 __btf_member_bit_offset(const struct btf_type *struct_type,
438 					  const struct btf_member *member)
439 {
440 	return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset)
441 					   : member->offset;
442 }
443 
__btf_member_bitfield_size(const struct btf_type * struct_type,const struct btf_member * member)444 static inline u32 __btf_member_bitfield_size(const struct btf_type *struct_type,
445 					     const struct btf_member *member)
446 {
447 	return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset)
448 					   : 0;
449 }
450 
btf_members(const struct btf_type * t)451 static inline struct btf_member *btf_members(const struct btf_type *t)
452 {
453 	return (struct btf_member *)(t + 1);
454 }
455 
btf_member_bit_offset(const struct btf_type * t,u32 member_idx)456 static inline u32 btf_member_bit_offset(const struct btf_type *t, u32 member_idx)
457 {
458 	const struct btf_member *m = btf_members(t) + member_idx;
459 
460 	return __btf_member_bit_offset(t, m);
461 }
462 
btf_member_bitfield_size(const struct btf_type * t,u32 member_idx)463 static inline u32 btf_member_bitfield_size(const struct btf_type *t, u32 member_idx)
464 {
465 	const struct btf_member *m = btf_members(t) + member_idx;
466 
467 	return __btf_member_bitfield_size(t, m);
468 }
469 
btf_type_member(const struct btf_type * t)470 static inline const struct btf_member *btf_type_member(const struct btf_type *t)
471 {
472 	return (const struct btf_member *)(t + 1);
473 }
474 
btf_array(const struct btf_type * t)475 static inline struct btf_array *btf_array(const struct btf_type *t)
476 {
477 	return (struct btf_array *)(t + 1);
478 }
479 
btf_enum(const struct btf_type * t)480 static inline struct btf_enum *btf_enum(const struct btf_type *t)
481 {
482 	return (struct btf_enum *)(t + 1);
483 }
484 
btf_enum64(const struct btf_type * t)485 static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
486 {
487 	return (struct btf_enum64 *)(t + 1);
488 }
489 
btf_type_var_secinfo(const struct btf_type * t)490 static inline const struct btf_var_secinfo *btf_type_var_secinfo(
491 		const struct btf_type *t)
492 {
493 	return (const struct btf_var_secinfo *)(t + 1);
494 }
495 
btf_params(const struct btf_type * t)496 static inline struct btf_param *btf_params(const struct btf_type *t)
497 {
498 	return (struct btf_param *)(t + 1);
499 }
500 
btf_decl_tag(const struct btf_type * t)501 static inline struct btf_decl_tag *btf_decl_tag(const struct btf_type *t)
502 {
503 	return (struct btf_decl_tag *)(t + 1);
504 }
505 
btf_id_cmp_func(const void * a,const void * b)506 static inline int btf_id_cmp_func(const void *a, const void *b)
507 {
508 	const int *pa = a, *pb = b;
509 
510 	return *pa - *pb;
511 }
512 
btf_id_set_contains(const struct btf_id_set * set,u32 id)513 static inline bool btf_id_set_contains(const struct btf_id_set *set, u32 id)
514 {
515 	return bsearch(&id, set->ids, set->cnt, sizeof(u32), btf_id_cmp_func) != NULL;
516 }
517 
btf_id_set8_contains(const struct btf_id_set8 * set,u32 id)518 static inline void *btf_id_set8_contains(const struct btf_id_set8 *set, u32 id)
519 {
520 	return bsearch(&id, set->pairs, set->cnt, sizeof(set->pairs[0]), btf_id_cmp_func);
521 }
522 
523 bool btf_param_match_suffix(const struct btf *btf,
524 			    const struct btf_param *arg,
525 			    const char *suffix);
526 int btf_ctx_arg_offset(const struct btf *btf, const struct btf_type *func_proto,
527 		       u32 arg_no);
528 u32 btf_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto, int off);
529 
530 struct bpf_verifier_log;
531 
532 #if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL)
533 struct bpf_struct_ops;
534 int __register_bpf_struct_ops(struct bpf_struct_ops *st_ops);
535 const struct bpf_struct_ops_desc *bpf_struct_ops_find_value(struct btf *btf, u32 value_id);
536 const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id);
537 #else
bpf_struct_ops_find(struct btf * btf,u32 type_id)538 static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id)
539 {
540 	return NULL;
541 }
542 #endif
543 
544 enum btf_field_iter_kind {
545 	BTF_FIELD_ITER_IDS,
546 	BTF_FIELD_ITER_STRS,
547 };
548 
549 struct btf_field_desc {
550 	/* once-per-type offsets */
551 	int t_off_cnt, t_offs[2];
552 	/* member struct size, or zero, if no members */
553 	int m_sz;
554 	/* repeated per-member offsets */
555 	int m_off_cnt, m_offs[1];
556 };
557 
558 struct btf_field_iter {
559 	struct btf_field_desc desc;
560 	void *p;
561 	int m_idx;
562 	int off_idx;
563 	int vlen;
564 };
565 
566 #ifdef CONFIG_BPF_SYSCALL
567 const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);
568 void btf_set_base_btf(struct btf *btf, const struct btf *base_btf);
569 int btf_relocate(struct btf *btf, const struct btf *base_btf, __u32 **map_ids);
570 int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t,
571 			enum btf_field_iter_kind iter_kind);
572 __u32 *btf_field_iter_next(struct btf_field_iter *it);
573 
574 const char *btf_name_by_offset(const struct btf *btf, u32 offset);
575 const char *btf_str_by_offset(const struct btf *btf, u32 offset);
576 struct btf *btf_parse_vmlinux(void);
577 struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog);
578 u32 *btf_kfunc_id_set_contains(const struct btf *btf, u32 kfunc_btf_id,
579 			       const struct bpf_prog *prog);
580 u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id,
581 				const struct bpf_prog *prog);
582 int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
583 			      const struct btf_kfunc_id_set *s);
584 int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset);
585 s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id);
586 int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt,
587 				struct module *owner);
588 struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id);
589 bool btf_is_projection_of(const char *pname, const char *tname);
590 bool btf_is_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
591 			   const struct btf_type *t, enum bpf_prog_type prog_type,
592 			   int arg);
593 int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type);
594 bool btf_types_are_same(const struct btf *btf1, u32 id1,
595 			const struct btf *btf2, u32 id2);
596 int btf_check_iter_arg(struct btf *btf, const struct btf_type *func, int arg_idx);
597 
btf_type_is_struct_ptr(struct btf * btf,const struct btf_type * t)598 static inline bool btf_type_is_struct_ptr(struct btf *btf, const struct btf_type *t)
599 {
600 	if (!btf_type_is_ptr(t))
601 		return false;
602 
603 	t = btf_type_skip_modifiers(btf, t->type, NULL);
604 
605 	return btf_type_is_struct(t);
606 }
607 #else
btf_type_by_id(const struct btf * btf,u32 type_id)608 static inline const struct btf_type *btf_type_by_id(const struct btf *btf,
609 						    u32 type_id)
610 {
611 	return NULL;
612 }
613 
btf_set_base_btf(struct btf * btf,const struct btf * base_btf)614 static inline void btf_set_base_btf(struct btf *btf, const struct btf *base_btf)
615 {
616 }
617 
btf_relocate(void * log,struct btf * btf,const struct btf * base_btf,__u32 ** map_ids)618 static inline int btf_relocate(void *log, struct btf *btf, const struct btf *base_btf,
619 			       __u32 **map_ids)
620 {
621 	return -EOPNOTSUPP;
622 }
623 
btf_field_iter_init(struct btf_field_iter * it,struct btf_type * t,enum btf_field_iter_kind iter_kind)624 static inline int btf_field_iter_init(struct btf_field_iter *it, struct btf_type *t,
625 				      enum btf_field_iter_kind iter_kind)
626 {
627 	return -EOPNOTSUPP;
628 }
629 
btf_field_iter_next(struct btf_field_iter * it)630 static inline __u32 *btf_field_iter_next(struct btf_field_iter *it)
631 {
632 	return NULL;
633 }
634 
btf_name_by_offset(const struct btf * btf,u32 offset)635 static inline const char *btf_name_by_offset(const struct btf *btf,
636 					     u32 offset)
637 {
638 	return NULL;
639 }
btf_kfunc_id_set_contains(const struct btf * btf,u32 kfunc_btf_id,struct bpf_prog * prog)640 static inline u32 *btf_kfunc_id_set_contains(const struct btf *btf,
641 					     u32 kfunc_btf_id,
642 					     struct bpf_prog *prog)
643 
644 {
645 	return NULL;
646 }
register_btf_kfunc_id_set(enum bpf_prog_type prog_type,const struct btf_kfunc_id_set * s)647 static inline int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
648 					    const struct btf_kfunc_id_set *s)
649 {
650 	return 0;
651 }
btf_find_dtor_kfunc(struct btf * btf,u32 btf_id)652 static inline s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id)
653 {
654 	return -ENOENT;
655 }
register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc * dtors,u32 add_cnt,struct module * owner)656 static inline int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors,
657 					      u32 add_cnt, struct module *owner)
658 {
659 	return 0;
660 }
btf_find_struct_meta(const struct btf * btf,u32 btf_id)661 static inline struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id)
662 {
663 	return NULL;
664 }
665 static inline bool
btf_is_prog_ctx_type(struct bpf_verifier_log * log,const struct btf * btf,const struct btf_type * t,enum bpf_prog_type prog_type,int arg)666 btf_is_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
667 		     const struct btf_type *t, enum bpf_prog_type prog_type,
668 		     int arg)
669 {
670 	return false;
671 }
get_kern_ctx_btf_id(struct bpf_verifier_log * log,enum bpf_prog_type prog_type)672 static inline int get_kern_ctx_btf_id(struct bpf_verifier_log *log,
673 				      enum bpf_prog_type prog_type) {
674 	return -EINVAL;
675 }
btf_types_are_same(const struct btf * btf1,u32 id1,const struct btf * btf2,u32 id2)676 static inline bool btf_types_are_same(const struct btf *btf1, u32 id1,
677 				      const struct btf *btf2, u32 id2)
678 {
679 	return false;
680 }
btf_check_iter_arg(struct btf * btf,const struct btf_type * func,int arg_idx)681 static inline int btf_check_iter_arg(struct btf *btf, const struct btf_type *func, int arg_idx)
682 {
683 	return -EOPNOTSUPP;
684 }
685 #endif
686 #endif
687