1	// SPDX-License-Identifier: GPL-2.0
2	/* Copyright (c) 2018 Facebook */
3
4	#include <uapi/linux/btf.h>
5	#include <uapi/linux/bpf.h>
6	#include <uapi/linux/bpf_perf_event.h>
7	#include <uapi/linux/types.h>
8	#include <linux/seq_file.h>
9	#include <linux/compiler.h>
10	#include <linux/ctype.h>
11	#include <linux/errno.h>
12	#include <linux/slab.h>
13	#include <linux/anon_inodes.h>
14	#include <linux/file.h>
15	#include <linux/uaccess.h>
16	#include <linux/kernel.h>
17	#include <linux/idr.h>
18	#include <linux/sort.h>
19	#include <linux/bpf_verifier.h>
20	#include <linux/btf.h>
21	#include <linux/btf_ids.h>
22	#include <linux/bpf_lsm.h>
23	#include <linux/skmsg.h>
24	#include <linux/perf_event.h>
25	#include <linux/bsearch.h>
26	#include <linux/kobject.h>
27	#include <linux/sysfs.h>
28
29	#include <net/netfilter/nf_bpf_link.h>
30
31	#include <net/sock.h>
32	#include <net/xdp.h>
33	#include "../tools/lib/bpf/relo_core.h"
34
35	/* BTF (BPF Type Format) is the meta data format which describes
36	* the data types of BPF program/map. Hence, it basically focus
37	* on the C programming language which the modern BPF is primary
38	* using.
39	*
40	* ELF Section:
41	* ~~~~~~~~~~~
42	* The BTF data is stored under the ".BTF" ELF section
43	*
44	* struct btf_type:
45	* ~~~~~~~~~~~~~~~
46	* Each 'struct btf_type' object describes a C data type.
47	* Depending on the type it is describing, a 'struct btf_type'
48	* object may be followed by more data. F.e.
49	* To describe an array, 'struct btf_type' is followed by
50	* 'struct btf_array'.
51	*
52	* 'struct btf_type' and any extra data following it are
53	* 4 bytes aligned.
54	*
55	* Type section:
56	* ~~~~~~~~~~~~~
57	* The BTF type section contains a list of 'struct btf_type' objects.
58	* Each one describes a C type. Recall from the above section
59	* that a 'struct btf_type' object could be immediately followed by extra
60	* data in order to describe some particular C types.
61	*
62	* type_id:
63	* ~~~~~~~
64	* Each btf_type object is identified by a type_id. The type_id
65	* is implicitly implied by the location of the btf_type object in
66	* the BTF type section. The first one has type_id 1. The second
67	* one has type_id 2...etc. Hence, an earlier btf_type has
68	* a smaller type_id.
69	*
70	* A btf_type object may refer to another btf_type object by using
71	* type_id (i.e. the "type" in the "struct btf_type").
72	*
73	* NOTE that we cannot assume any reference-order.
74	* A btf_type object can refer to an earlier btf_type object
75	* but it can also refer to a later btf_type object.
76	*
77	* For example, to describe "const void *". A btf_type
78	* object describing "const" may refer to another btf_type
79	* object describing "void *". This type-reference is done
80	* by specifying type_id:
81	*
82	* [1] CONST (anon) type_id=2
83	* [2] PTR (anon) type_id=0
84	*
85	* The above is the btf_verifier debug log:
86	* - Each line started with "[?]" is a btf_type object
87	* - [?] is the type_id of the btf_type object.
88	* - CONST/PTR is the BTF_KIND_XXX
89	* - "(anon)" is the name of the type. It just
90	* happens that CONST and PTR has no name.
91	* - type_id=XXX is the 'u32 type' in btf_type
92	*
93	* NOTE: "void" has type_id 0
94	*
95	* String section:
96	* ~~~~~~~~~~~~~~
97	* The BTF string section contains the names used by the type section.
98	* Each string is referred by an "offset" from the beginning of the
99	* string section.
100	*
101	* Each string is '\0' terminated.
102	*
103	* The first character in the string section must be '\0'
104	* which is used to mean 'anonymous'. Some btf_type may not
105	* have a name.
106	*/
107
108	/* BTF verification:
109	*
110	* To verify BTF data, two passes are needed.
111	*
112	* Pass #1
113	* ~~~~~~~
114	* The first pass is to collect all btf_type objects to
115	* an array: "btf->types".
116	*
117	* Depending on the C type that a btf_type is describing,
118	* a btf_type may be followed by extra data. We don't know
119	* how many btf_type is there, and more importantly we don't
120	* know where each btf_type is located in the type section.
121	*
122	* Without knowing the location of each type_id, most verifications
123	* cannot be done. e.g. an earlier btf_type may refer to a later
124	* btf_type (recall the "const void *" above), so we cannot
125	* check this type-reference in the first pass.
126	*
127	* In the first pass, it still does some verifications (e.g.
128	* checking the name is a valid offset to the string section).
129	*
130	* Pass #2
131	* ~~~~~~~
132	* The main focus is to resolve a btf_type that is referring
133	* to another type.
134	*
135	* We have to ensure the referring type:
136	* 1) does exist in the BTF (i.e. in btf->types[])
137	* 2) does not cause a loop:
138	* struct A {
139	* struct B b;
140	* };
141	*
142	* struct B {
143	* struct A a;
144	* };
145	*
146	* btf_type_needs_resolve() decides if a btf_type needs
147	* to be resolved.
148	*
149	* The needs_resolve type implements the "resolve()" ops which
150	* essentially does a DFS and detects backedge.
151	*
152	* During resolve (or DFS), different C types have different
153	* "RESOLVED" conditions.
154	*
155	* When resolving a BTF_KIND_STRUCT, we need to resolve all its
156	* members because a member is always referring to another
157	* type. A struct's member can be treated as "RESOLVED" if
158	* it is referring to a BTF_KIND_PTR. Otherwise, the
159	* following valid C struct would be rejected:
160	*
161	* struct A {
162	* int m;
163	* struct A *a;
164	* };
165	*
166	* When resolving a BTF_KIND_PTR, it needs to keep resolving if
167	* it is referring to another BTF_KIND_PTR. Otherwise, we cannot
168	* detect a pointer loop, e.g.:
169	* BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR +
170	* ^ |
171	* +-----------------------------------------+
172	*
173	*/
174
175	#define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2)
176	#define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1)
177	#define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK)
178	#define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3)
179	#define BITS_ROUNDUP_BYTES(bits) \
180	(BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits))
181
182	#define BTF_INFO_MASK 0x9f00ffff
183	#define BTF_INT_MASK 0x0fffffff
184	#define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE)
185	#define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET)
186
187	/* 16MB for 64k structs and each has 16 members and
188	* a few MB spaces for the string section.
189	* The hard limit is S32_MAX.
190	*/
191	#define BTF_MAX_SIZE (16 * 1024 * 1024)
192
193	#define for_each_member_from(i, from, struct_type, member) \
194	for (i = from, member = btf_type_member(struct_type) + from; \
195	i < btf_type_vlen(struct_type); \
196	i++, member++)
197
198	#define for_each_vsi_from(i, from, struct_type, member) \
199	for (i = from, member = btf_type_var_secinfo(struct_type) + from; \
200	i < btf_type_vlen(struct_type); \
201	i++, member++)
202
203	DEFINE_IDR(btf_idr);
204	DEFINE_SPINLOCK(btf_idr_lock);
205
206	enum btf_kfunc_hook {
207	BTF_KFUNC_HOOK_COMMON,
208	BTF_KFUNC_HOOK_XDP,
209	BTF_KFUNC_HOOK_TC,
210	BTF_KFUNC_HOOK_STRUCT_OPS,
211	BTF_KFUNC_HOOK_TRACING,
212	BTF_KFUNC_HOOK_SYSCALL,
213	BTF_KFUNC_HOOK_FMODRET,
214	BTF_KFUNC_HOOK_CGROUP_SKB,
215	BTF_KFUNC_HOOK_SCHED_ACT,
216	BTF_KFUNC_HOOK_SK_SKB,
217	BTF_KFUNC_HOOK_SOCKET_FILTER,
218	BTF_KFUNC_HOOK_LWT,
219	BTF_KFUNC_HOOK_NETFILTER,
220	BTF_KFUNC_HOOK_MAX,
221	};
222
223	enum {
224	BTF_KFUNC_SET_MAX_CNT = 256,
225	BTF_DTOR_KFUNC_MAX_CNT = 256,
226	BTF_KFUNC_FILTER_MAX_CNT = 16,
227	};
228
229	struct btf_kfunc_hook_filter {
230	btf_kfunc_filter_t filters[BTF_KFUNC_FILTER_MAX_CNT];
231	u32 nr_filters;
232	};
233
234	struct btf_kfunc_set_tab {
235	struct btf_id_set8 *sets[BTF_KFUNC_HOOK_MAX];
236	struct btf_kfunc_hook_filter hook_filters[BTF_KFUNC_HOOK_MAX];
237	};
238
239	struct btf_id_dtor_kfunc_tab {
240	u32 cnt;
241	struct btf_id_dtor_kfunc dtors[];
242	};
243
244	struct btf {
245	void *data;
246	struct btf_type **types;
247	u32 *resolved_ids;
248	u32 *resolved_sizes;
249	const char *strings;
250	void *nohdr_data;
251	struct btf_header hdr;
252	u32 nr_types; /* includes VOID for base BTF */
253	u32 types_size;
254	u32 data_size;
255	refcount_t refcnt;
256	u32 id;
257	struct rcu_head rcu;
258	struct btf_kfunc_set_tab *kfunc_set_tab;
259	struct btf_id_dtor_kfunc_tab *dtor_kfunc_tab;
260	struct btf_struct_metas *struct_meta_tab;
261
262	/* split BTF support */
263	struct btf *base_btf;
264	u32 start_id; /* first type ID in this BTF (0 for base BTF) */
265	u32 start_str_off; /* first string offset (0 for base BTF) */
266	char name[MODULE_NAME_LEN];
267	bool kernel_btf;
268	};
269
270	enum verifier_phase {
271	CHECK_META,
272	CHECK_TYPE,
273	};
274
275	struct resolve_vertex {
276	const struct btf_type *t;
277	u32 type_id;
278	u16 next_member;
279	};
280
281	enum visit_state {
282	NOT_VISITED,
283	VISITED,
284	RESOLVED,
285	};
286
287	enum resolve_mode {
288	RESOLVE_TBD, /* To Be Determined */
289	RESOLVE_PTR, /* Resolving for Pointer */
290	RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union
291	* or array
292	*/
293	};
294
295	#define MAX_RESOLVE_DEPTH 32
296
297	struct btf_sec_info {
298	u32 off;
299	u32 len;
300	};
301
302	struct btf_verifier_env {
303	struct btf *btf;
304	u8 *visit_states;
305	struct resolve_vertex stack[MAX_RESOLVE_DEPTH];
306	struct bpf_verifier_log log;
307	u32 log_type_id;
308	u32 top_stack;
309	enum verifier_phase phase;
310	enum resolve_mode resolve_mode;
311	};
312
313	static const char * const btf_kind_str[NR_BTF_KINDS] = {
314	[BTF_KIND_UNKN] = "UNKNOWN",
315	[BTF_KIND_INT] = "INT",
316	[BTF_KIND_PTR] = "PTR",
317	[BTF_KIND_ARRAY] = "ARRAY",
318	[BTF_KIND_STRUCT] = "STRUCT",
319	[BTF_KIND_UNION] = "UNION",
320	[BTF_KIND_ENUM] = "ENUM",
321	[BTF_KIND_FWD] = "FWD",
322	[BTF_KIND_TYPEDEF] = "TYPEDEF",
323	[BTF_KIND_VOLATILE] = "VOLATILE",
324	[BTF_KIND_CONST] = "CONST",
325	[BTF_KIND_RESTRICT] = "RESTRICT",
326	[BTF_KIND_FUNC] = "FUNC",
327	[BTF_KIND_FUNC_PROTO] = "FUNC_PROTO",
328	[BTF_KIND_VAR] = "VAR",
329	[BTF_KIND_DATASEC] = "DATASEC",
330	[BTF_KIND_FLOAT] = "FLOAT",
331	[BTF_KIND_DECL_TAG] = "DECL_TAG",
332	[BTF_KIND_TYPE_TAG] = "TYPE_TAG",
333	[BTF_KIND_ENUM64] = "ENUM64",
334	};
335
336	const char *btf_type_str(const struct btf_type *t)
337	{
338	return btf_kind_str[BTF_INFO_KIND(t->info)];
339	}
340
341	/* Chunk size we use in safe copy of data to be shown. */
342	#define BTF_SHOW_OBJ_SAFE_SIZE 32
343
344	/*
345	* This is the maximum size of a base type value (equivalent to a
346	* 128-bit int); if we are at the end of our safe buffer and have
347	* less than 16 bytes space we can't be assured of being able
348	* to copy the next type safely, so in such cases we will initiate
349	* a new copy.
350	*/
351	#define BTF_SHOW_OBJ_BASE_TYPE_SIZE 16
352
353	/* Type name size */
354	#define BTF_SHOW_NAME_SIZE 80
355
356	/*
357	* The suffix of a type that indicates it cannot alias another type when
358	* comparing BTF IDs for kfunc invocations.
359	*/
360	#define NOCAST_ALIAS_SUFFIX "___init"
361
362	/*
363	* Common data to all BTF show operations. Private show functions can add
364	* their own data to a structure containing a struct btf_show and consult it
365	* in the show callback. See btf_type_show() below.
366	*
367	* One challenge with showing nested data is we want to skip 0-valued
368	* data, but in order to figure out whether a nested object is all zeros
369	* we need to walk through it. As a result, we need to make two passes
370	* when handling structs, unions and arrays; the first path simply looks
371	* for nonzero data, while the second actually does the display. The first
372	* pass is signalled by show->state.depth_check being set, and if we
373	* encounter a non-zero value we set show->state.depth_to_show to
374	* the depth at which we encountered it. When we have completed the
375	* first pass, we will know if anything needs to be displayed if
376	* depth_to_show > depth. See btf_[struct,array]_show() for the
377	* implementation of this.
378	*
379	* Another problem is we want to ensure the data for display is safe to
380	* access. To support this, the anonymous "struct {} obj" tracks the data
381	* object and our safe copy of it. We copy portions of the data needed
382	* to the object "copy" buffer, but because its size is limited to
383	* BTF_SHOW_OBJ_COPY_LEN bytes, multiple copies may be required as we
384	* traverse larger objects for display.
385	*
386	* The various data type show functions all start with a call to
387	* btf_show_start_type() which returns a pointer to the safe copy
388	* of the data needed (or if BTF_SHOW_UNSAFE is specified, to the
389	* raw data itself). btf_show_obj_safe() is responsible for
390	* using copy_from_kernel_nofault() to update the safe data if necessary
391	* as we traverse the object's data. skbuff-like semantics are
392	* used:
393	*
394	* - obj.head points to the start of the toplevel object for display
395	* - obj.size is the size of the toplevel object
396	* - obj.data points to the current point in the original data at
397	* which our safe data starts. obj.data will advance as we copy
398	* portions of the data.
399	*
400	* In most cases a single copy will suffice, but larger data structures
401	* such as "struct task_struct" will require many copies. The logic in
402	* btf_show_obj_safe() handles the logic that determines if a new
403	* copy_from_kernel_nofault() is needed.
404	*/
405	struct btf_show {
406	u64 flags;
407	void *target; /* target of show operation (seq file, buffer) */
408	void (*showfn)(struct btf_show *show, const char *fmt, va_list args);
409	const struct btf *btf;
410	/* below are used during iteration */
411	struct {
412	u8 depth;
413	u8 depth_to_show;
414	u8 depth_check;
415	u8 array_member:1,
416	array_terminated:1;
417	u16 array_encoding;
418	u32 type_id;
419	int status; /* non-zero for error */
420	const struct btf_type *type;
421	const struct btf_member *member;
422	char name[BTF_SHOW_NAME_SIZE]; /* space for member name/type */
423	} state;
424	struct {
425	u32 size;
426	void *head;
427	void *data;
428	u8 safe[BTF_SHOW_OBJ_SAFE_SIZE];
429	} obj;
430	};
431
432	struct btf_kind_operations {
433	s32 (*check_meta)(struct btf_verifier_env *env,
434	const struct btf_type *t,
435	u32 meta_left);
436	int (*resolve)(struct btf_verifier_env *env,
437	const struct resolve_vertex *v);
438	int (*check_member)(struct btf_verifier_env *env,
439	const struct btf_type *struct_type,
440	const struct btf_member *member,
441	const struct btf_type *member_type);
442	int (*check_kflag_member)(struct btf_verifier_env *env,
443	const struct btf_type *struct_type,
444	const struct btf_member *member,
445	const struct btf_type *member_type);
446	void (*log_details)(struct btf_verifier_env *env,
447	const struct btf_type *t);
448	void (*show)(const struct btf *btf, const struct btf_type *t,
449	u32 type_id, void *data, u8 bits_offsets,
450	struct btf_show *show);
451	};
452
453	static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS];
454	static struct btf_type btf_void;
455
456	static int btf_resolve(struct btf_verifier_env *env,
457	const struct btf_type *t, u32 type_id);
458
459	static int btf_func_check(struct btf_verifier_env *env,
460	const struct btf_type *t);
461
462	static bool btf_type_is_modifier(const struct btf_type *t)
463	{
464	/* Some of them is not strictly a C modifier
465	* but they are grouped into the same bucket
466	* for BTF concern:
467	* A type (t) that refers to another
468	* type through t->type AND its size cannot
469	* be determined without following the t->type.
470	*
471	* ptr does not fall into this bucket
472	* because its size is always sizeof(void *).
473	*/
474	switch (BTF_INFO_KIND(t->info)) {
475	case BTF_KIND_TYPEDEF:
476	case BTF_KIND_VOLATILE:
477	case BTF_KIND_CONST:
478	case BTF_KIND_RESTRICT:
479	case BTF_KIND_TYPE_TAG:
480	return true;
481	}
482
483	return false;
484	}
485
486	bool btf_type_is_void(const struct btf_type *t)
487	{
488	return t == &btf_void;
489	}
490
491	static bool btf_type_is_fwd(const struct btf_type *t)
492	{
493	return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
494	}
495
496	static bool btf_type_is_datasec(const struct btf_type *t)
497	{
498	return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
499	}
500
501	static bool btf_type_is_decl_tag(const struct btf_type *t)
502	{
503	return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG;
504	}
505
506	static bool btf_type_nosize(const struct btf_type *t)
507	{
508	return btf_type_is_void(t) || btf_type_is_fwd(t) ||
509	btf_type_is_func(t) || btf_type_is_func_proto(t) ||
510	btf_type_is_decl_tag(t);
511	}
512
513	static bool btf_type_nosize_or_null(const struct btf_type *t)
514	{
515	return !t || btf_type_nosize(t);
516	}
517
518	static bool btf_type_is_decl_tag_target(const struct btf_type *t)
519	{
520	return btf_type_is_func(t) || btf_type_is_struct(t) ||
521	btf_type_is_var(t) || btf_type_is_typedef(t);
522	}
523
524	u32 btf_nr_types(const struct btf *btf)
525	{
526	u32 total = 0;
527
528	while (btf) {
529	total += btf->nr_types;
530	btf = btf->base_btf;
531	}
532
533	return total;
534	}
535
536	s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind)
537	{
538	const struct btf_type *t;
539	const char *tname;
540	u32 i, total;
541
542	total = btf_nr_types(btf);
543	for (i = 1; i < total; i++) {
544	t = btf_type_by_id(btf, type_id: i);
545	if (BTF_INFO_KIND(t->info) != kind)
546	continue;
547
548	tname = btf_name_by_offset(btf, offset: t->name_off);
549	if (!strcmp(tname, name))
550	return i;
551	}
552
553	return -ENOENT;
554	}
555
556	s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p)
557	{
558	struct btf *btf;
559	s32 ret;
560	int id;
561
562	btf = bpf_get_btf_vmlinux();
563	if (IS_ERR(ptr: btf))
564	return PTR_ERR(ptr: btf);
565	if (!btf)
566	return -EINVAL;
567
568	ret = btf_find_by_name_kind(btf, name, kind);
569	/* ret is never zero, since btf_find_by_name_kind returns
570	* positive btf_id or negative error.
571	*/
572	if (ret > 0) {
573	btf_get(btf);
574	*btf_p = btf;
575	return ret;
576	}
577
578	/* If name is not found in vmlinux's BTF then search in module's BTFs */
579	spin_lock_bh(lock: &btf_idr_lock);
580	idr_for_each_entry(&btf_idr, btf, id) {
581	if (!btf_is_module(btf))
582	continue;
583	/* linear search could be slow hence unlock/lock
584	* the IDR to avoiding holding it for too long
585	*/
586	btf_get(btf);
587	spin_unlock_bh(lock: &btf_idr_lock);
588	ret = btf_find_by_name_kind(btf, name, kind);
589	if (ret > 0) {
590	*btf_p = btf;
591	return ret;
592	}
593	btf_put(btf);
594	spin_lock_bh(lock: &btf_idr_lock);
595	}
596	spin_unlock_bh(lock: &btf_idr_lock);
597	return ret;
598	}
599
600	const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
601	u32 id, u32 *res_id)
602	{
603	const struct btf_type *t = btf_type_by_id(btf, type_id: id);
604
605	while (btf_type_is_modifier(t)) {
606	id = t->type;
607	t = btf_type_by_id(btf, type_id: t->type);
608	}
609
610	if (res_id)
611	*res_id = id;
612
613	return t;
614	}
615
616	const struct btf_type *btf_type_resolve_ptr(const struct btf *btf,
617	u32 id, u32 *res_id)
618	{
619	const struct btf_type *t;
620
621	t = btf_type_skip_modifiers(btf, id, NULL);
622	if (!btf_type_is_ptr(t))
623	return NULL;
624
625	return btf_type_skip_modifiers(btf, id: t->type, res_id);
626	}
627
628	const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
629	u32 id, u32 *res_id)
630	{
631	const struct btf_type *ptype;
632
633	ptype = btf_type_resolve_ptr(btf, id, res_id);
634	if (ptype && btf_type_is_func_proto(t: ptype))
635	return ptype;
636
637	return NULL;
638	}
639
640	/* Types that act only as a source, not sink or intermediate
641	* type when resolving.
642	*/
643	static bool btf_type_is_resolve_source_only(const struct btf_type *t)
644	{
645	return btf_type_is_var(t) ||
646	btf_type_is_decl_tag(t) ||
647	btf_type_is_datasec(t);
648	}
649
650	/* What types need to be resolved?
651	*
652	* btf_type_is_modifier() is an obvious one.
653	*
654	* btf_type_is_struct() because its member refers to
655	* another type (through member->type).
656	*
657	* btf_type_is_var() because the variable refers to
658	* another type. btf_type_is_datasec() holds multiple
659	* btf_type_is_var() types that need resolving.
660	*
661	* btf_type_is_array() because its element (array->type)
662	* refers to another type. Array can be thought of a
663	* special case of struct while array just has the same
664	* member-type repeated by array->nelems of times.
665	*/
666	static bool btf_type_needs_resolve(const struct btf_type *t)
667	{
668	return btf_type_is_modifier(t) ||
669	btf_type_is_ptr(t) ||
670	btf_type_is_struct(t) ||
671	btf_type_is_array(t) ||
672	btf_type_is_var(t) ||
673	btf_type_is_func(t) ||
674	btf_type_is_decl_tag(t) ||
675	btf_type_is_datasec(t);
676	}
677
678	/* t->size can be used */
679	static bool btf_type_has_size(const struct btf_type *t)
680	{
681	switch (BTF_INFO_KIND(t->info)) {
682	case BTF_KIND_INT:
683	case BTF_KIND_STRUCT:
684	case BTF_KIND_UNION:
685	case BTF_KIND_ENUM:
686	case BTF_KIND_DATASEC:
687	case BTF_KIND_FLOAT:
688	case BTF_KIND_ENUM64:
689	return true;
690	}
691
692	return false;
693	}
694
695	static const char *btf_int_encoding_str(u8 encoding)
696	{
697	if (encoding == 0)
698	return "(none)";
699	else if (encoding == BTF_INT_SIGNED)
700	return "SIGNED";
701	else if (encoding == BTF_INT_CHAR)
702	return "CHAR";
703	else if (encoding == BTF_INT_BOOL)
704	return "BOOL";
705	else
706	return "UNKN";
707	}
708
709	static u32 btf_type_int(const struct btf_type *t)
710	{
711	return *(u32 *)(t + 1);
712	}
713
714	static const struct btf_array *btf_type_array(const struct btf_type *t)
715	{
716	return (const struct btf_array *)(t + 1);
717	}
718
719	static const struct btf_enum *btf_type_enum(const struct btf_type *t)
720	{
721	return (const struct btf_enum *)(t + 1);
722	}
723
724	static const struct btf_var *btf_type_var(const struct btf_type *t)
725	{
726	return (const struct btf_var *)(t + 1);
727	}
728
729	static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t)
730	{
731	return (const struct btf_decl_tag *)(t + 1);
732	}
733
734	static const struct btf_enum64 *btf_type_enum64(const struct btf_type *t)
735	{
736	return (const struct btf_enum64 *)(t + 1);
737	}
738
739	static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
740	{
741	return kind_ops[BTF_INFO_KIND(t->info)];
742	}
743
744	static bool btf_name_offset_valid(const struct btf *btf, u32 offset)
745	{
746	if (!BTF_STR_OFFSET_VALID(offset))
747	return false;
748
749	while (offset < btf->start_str_off)
750	btf = btf->base_btf;
751
752	offset -= btf->start_str_off;
753	return offset < btf->hdr.str_len;
754	}
755
756	static bool __btf_name_char_ok(char c, bool first)
757	{
758	if ((first ? !isalpha(c) :
759	!isalnum(c)) &&
760	c != '_' &&
761	c != '.')
762	return false;
763	return true;
764	}
765
766	static const char *btf_str_by_offset(const struct btf *btf, u32 offset)
767	{
768	while (offset < btf->start_str_off)
769	btf = btf->base_btf;
770
771	offset -= btf->start_str_off;
772	if (offset < btf->hdr.str_len)
773	return &btf->strings[offset];
774
775	return NULL;
776	}
777
778	static bool __btf_name_valid(const struct btf *btf, u32 offset)
779	{
780	/* offset must be valid */
781	const char *src = btf_str_by_offset(btf, offset);
782	const char *src_limit;
783
784	if (!__btf_name_char_ok(c: *src, first: true))
785	return false;
786
787	/* set a limit on identifier length */
788	src_limit = src + KSYM_NAME_LEN;
789	src++;
790	while (*src && src < src_limit) {
791	if (!__btf_name_char_ok(c: *src, first: false))
792	return false;
793	src++;
794	}
795
796	return !*src;
797	}
798
799	static bool btf_name_valid_identifier(const struct btf *btf, u32 offset)
800	{
801	return __btf_name_valid(btf, offset);
802	}
803
804	static bool btf_name_valid_section(const struct btf *btf, u32 offset)
805	{
806	return __btf_name_valid(btf, offset);
807	}
808
809	static const char *__btf_name_by_offset(const struct btf *btf, u32 offset)
810	{
811	const char *name;
812
813	if (!offset)
814	return "(anon)";
815
816	name = btf_str_by_offset(btf, offset);
817	return name ?: "(invalid-name-offset)";
818	}
819
820	const char *btf_name_by_offset(const struct btf *btf, u32 offset)
821	{
822	return btf_str_by_offset(btf, offset);
823	}
824
825	const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id)
826	{
827	while (type_id < btf->start_id)
828	btf = btf->base_btf;
829
830	type_id -= btf->start_id;
831	if (type_id >= btf->nr_types)
832	return NULL;
833	return btf->types[type_id];
834	}
835	EXPORT_SYMBOL_GPL(btf_type_by_id);
836
837	/*
838	* Regular int is not a bit field and it must be either
839	* u8/u16/u32/u64 or __int128.
840	*/
841	static bool btf_type_int_is_regular(const struct btf_type *t)
842	{
843	u8 nr_bits, nr_bytes;
844	u32 int_data;
845
846	int_data = btf_type_int(t);
847	nr_bits = BTF_INT_BITS(int_data);
848	nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);
849	if (BITS_PER_BYTE_MASKED(nr_bits) ||
850	BTF_INT_OFFSET(int_data) ||
851	(nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) &&
852	nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) &&
853	nr_bytes != (2 * sizeof(u64)))) {
854	return false;
855	}
856
857	return true;
858	}
859
860	/*
861	* Check that given struct member is a regular int with expected
862	* offset and size.
863	*/
864	bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
865	const struct btf_member *m,
866	u32 expected_offset, u32 expected_size)
867	{
868	const struct btf_type *t;
869	u32 id, int_data;
870	u8 nr_bits;
871
872	id = m->type;
873	t = btf_type_id_size(btf, type_id: &id, NULL);
874	if (!t || !btf_type_is_int(t))
875	return false;
876
877	int_data = btf_type_int(t);
878	nr_bits = BTF_INT_BITS(int_data);
879	if (btf_type_kflag(t: s)) {
880	u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);
881	u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);
882
883	/* if kflag set, int should be a regular int and
884	* bit offset should be at byte boundary.
885	*/
886	return !bitfield_size &&
887	BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&
888	BITS_ROUNDUP_BYTES(nr_bits) == expected_size;
889	}
890
891	if (BTF_INT_OFFSET(int_data) ||
892	BITS_PER_BYTE_MASKED(m->offset) ||
893	BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||
894	BITS_PER_BYTE_MASKED(nr_bits) ||
895	BITS_ROUNDUP_BYTES(nr_bits) != expected_size)
896	return false;
897
898	return true;
899	}
900
901	/* Similar to btf_type_skip_modifiers() but does not skip typedefs. */
902	static const struct btf_type *btf_type_skip_qualifiers(const struct btf *btf,
903	u32 id)
904	{
905	const struct btf_type *t = btf_type_by_id(btf, id);
906
907	while (btf_type_is_modifier(t) &&
908	BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) {
909	t = btf_type_by_id(btf, t->type);
910	}
911
912	return t;
913	}
914
915	#define BTF_SHOW_MAX_ITER 10
916
917	#define BTF_KIND_BIT(kind) (1ULL << kind)
918
919	/*
920	* Populate show->state.name with type name information.
921	* Format of type name is
922	*
923	* [.member_name = ] (type_name)
924	*/
925	static const char *btf_show_name(struct btf_show *show)
926	{
927	/* BTF_MAX_ITER array suffixes "[]" */
928	const char *array_suffixes = "[][][][][][][][][][]";
929	const char *array_suffix = &array_suffixes[strlen(array_suffixes)];
930	/* BTF_MAX_ITER pointer suffixes "*" */
931	const char *ptr_suffixes = "**********";
932	const char *ptr_suffix = &ptr_suffixes[strlen(ptr_suffixes)];
933	const char *name = NULL, *prefix = "", *parens = "";
934	const struct btf_member *m = show->state.member;
935	const struct btf_type *t;
936	const struct btf_array *array;
937	u32 id = show->state.type_id;
938	const char *member = NULL;
939	bool show_member = false;
940	u64 kinds = 0;
941	int i;
942
943	show->state.name[0] = '\0';
944
945	/*
946	* Don't show type name if we're showing an array member;
947	* in that case we show the array type so don't need to repeat
948	* ourselves for each member.
949	*/
950	if (show->state.array_member)
951	return "";
952
953	/* Retrieve member name, if any. */
954	if (m) {
955	member = btf_name_by_offset(btf: show->btf, offset: m->name_off);
956	show_member = strlen(member) > 0;
957	id = m->type;
958	}
959
960	/*
961	* Start with type_id, as we have resolved the struct btf_type *
962	* via btf_modifier_show() past the parent typedef to the child
963	* struct, int etc it is defined as. In such cases, the type_id
964	* still represents the starting type while the struct btf_type *
965	* in our show->state points at the resolved type of the typedef.
966	*/
967	t = btf_type_by_id(show->btf, id);
968	if (!t)
969	return "";
970
971	/*
972	* The goal here is to build up the right number of pointer and
973	* array suffixes while ensuring the type name for a typedef
974	* is represented. Along the way we accumulate a list of
975	* BTF kinds we have encountered, since these will inform later
976	* display; for example, pointer types will not require an
977	* opening "{" for struct, we will just display the pointer value.
978	*
979	* We also want to accumulate the right number of pointer or array
980	* indices in the format string while iterating until we get to
981	* the typedef/pointee/array member target type.
982	*
983	* We start by pointing at the end of pointer and array suffix
984	* strings; as we accumulate pointers and arrays we move the pointer
985	* or array string backwards so it will show the expected number of
986	* '*' or '[]' for the type. BTF_SHOW_MAX_ITER of nesting of pointers
987	* and/or arrays and typedefs are supported as a precaution.
988	*
989	* We also want to get typedef name while proceeding to resolve
990	* type it points to so that we can add parentheses if it is a
991	* "typedef struct" etc.
992	*/
993	for (i = 0; i < BTF_SHOW_MAX_ITER; i++) {
994
995	switch (BTF_INFO_KIND(t->info)) {
996	case BTF_KIND_TYPEDEF:
997	if (!name)
998	name = btf_name_by_offset(btf: show->btf,
999	offset: t->name_off);
1000	kinds |= BTF_KIND_BIT(BTF_KIND_TYPEDEF);
1001	id = t->type;
1002	break;
1003	case BTF_KIND_ARRAY:
1004	kinds |= BTF_KIND_BIT(BTF_KIND_ARRAY);
1005	parens = "[";
1006	if (!t)
1007	return "";
1008	array = btf_type_array(t);
1009	if (array_suffix > array_suffixes)
1010	array_suffix -= 2;
1011	id = array->type;
1012	break;
1013	case BTF_KIND_PTR:
1014	kinds |= BTF_KIND_BIT(BTF_KIND_PTR);
1015	if (ptr_suffix > ptr_suffixes)
1016	ptr_suffix -= 1;
1017	id = t->type;
1018	break;
1019	default:
1020	id = 0;
1021	break;
1022	}
1023	if (!id)
1024	break;
1025	t = btf_type_skip_qualifiers(btf: show->btf, id);
1026	}
1027	/* We may not be able to represent this type; bail to be safe */
1028	if (i == BTF_SHOW_MAX_ITER)
1029	return "";
1030
1031	if (!name)
1032	name = btf_name_by_offset(btf: show->btf, offset: t->name_off);
1033
1034	switch (BTF_INFO_KIND(t->info)) {
1035	case BTF_KIND_STRUCT:
1036	case BTF_KIND_UNION:
1037	prefix = BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT ?
1038	"struct" : "union";
1039	/* if it's an array of struct/union, parens is already set */
1040	if (!(kinds & (BTF_KIND_BIT(BTF_KIND_ARRAY))))
1041	parens = "{";
1042	break;
1043	case BTF_KIND_ENUM:
1044	case BTF_KIND_ENUM64:
1045	prefix = "enum";
1046	break;
1047	default:
1048	break;
1049	}
1050
1051	/* pointer does not require parens */
1052	if (kinds & BTF_KIND_BIT(BTF_KIND_PTR))
1053	parens = "";
1054	/* typedef does not require struct/union/enum prefix */
1055	if (kinds & BTF_KIND_BIT(BTF_KIND_TYPEDEF))
1056	prefix = "";
1057
1058	if (!name)
1059	name = "";
1060
1061	/* Even if we don't want type name info, we want parentheses etc */
1062	if (show->flags & BTF_SHOW_NONAME)
1063	snprintf(buf: show->state.name, size: sizeof(show->state.name), fmt: "%s",
1064	parens);
1065	else
1066	snprintf(buf: show->state.name, size: sizeof(show->state.name),
1067	fmt: "%s%s%s(%s%s%s%s%s%s)%s",
1068	/* first 3 strings comprise ".member = " */
1069	show_member ? "." : "",
1070	show_member ? member : "",
1071	show_member ? " = " : "",
1072	/* ...next is our prefix (struct, enum, etc) */
1073	prefix,
1074	strlen(prefix) > 0 && strlen(name) > 0 ? " " : "",
1075	/* ...this is the type name itself */
1076	name,
1077	/* ...suffixed by the appropriate '*', '[]' suffixes */
1078	strlen(ptr_suffix) > 0 ? " " : "", ptr_suffix,
1079	array_suffix, parens);
1080
1081	return show->state.name;
1082	}
1083
1084	static const char *__btf_show_indent(struct btf_show *show)
1085	{
1086	const char *indents = " ";
1087	const char *indent = &indents[strlen(indents)];
1088
1089	if ((indent - show->state.depth) >= indents)
1090	return indent - show->state.depth;
1091	return indents;
1092	}
1093
1094	static const char *btf_show_indent(struct btf_show *show)
1095	{
1096	return show->flags & BTF_SHOW_COMPACT ? "" : __btf_show_indent(show);
1097	}
1098
1099	static const char *btf_show_newline(struct btf_show *show)
1100	{
1101	return show->flags & BTF_SHOW_COMPACT ? "" : "\n";
1102	}
1103
1104	static const char *btf_show_delim(struct btf_show *show)
1105	{
1106	if (show->state.depth == 0)
1107	return "";
1108
1109	if ((show->flags & BTF_SHOW_COMPACT) && show->state.type &&
1110	BTF_INFO_KIND(show->state.type->info) == BTF_KIND_UNION)
1111	return "|";
1112
1113	return ",";
1114	}
1115
1116	__printf(2, 3) static void btf_show(struct btf_show *show, const char *fmt, ...)
1117	{
1118	va_list args;
1119
1120	if (!show->state.depth_check) {
1121	va_start(args, fmt);
1122	show->showfn(show, fmt, args);
1123	va_end(args);
1124	}
1125	}
1126
1127	/* Macros are used here as btf_show_type_value[s]() prepends and appends
1128	* format specifiers to the format specifier passed in; these do the work of
1129	* adding indentation, delimiters etc while the caller simply has to specify
1130	* the type value(s) in the format specifier + value(s).
1131	*/
1132	#define btf_show_type_value(show, fmt, value) \
1133	do { \
1134	if ((value) != (__typeof__(value))0 || \
1135	(show->flags & BTF_SHOW_ZERO) || \
1136	show->state.depth == 0) { \
1137	btf_show(show, "%s%s" fmt "%s%s", \
1138	btf_show_indent(show), \
1139	btf_show_name(show), \
1140	value, btf_show_delim(show), \
1141	btf_show_newline(show)); \
1142	if (show->state.depth > show->state.depth_to_show) \
1143	show->state.depth_to_show = show->state.depth; \
1144	} \
1145	} while (0)
1146
1147	#define btf_show_type_values(show, fmt, ...) \
1148	do { \
1149	btf_show(show, "%s%s" fmt "%s%s", btf_show_indent(show), \
1150	btf_show_name(show), \
1151	__VA_ARGS__, btf_show_delim(show), \
1152	btf_show_newline(show)); \
1153	if (show->state.depth > show->state.depth_to_show) \
1154	show->state.depth_to_show = show->state.depth; \
1155	} while (0)
1156
1157	/* How much is left to copy to safe buffer after @data? */
1158	static int btf_show_obj_size_left(struct btf_show *show, void *data)
1159	{
1160	return show->obj.head + show->obj.size - data;
1161	}
1162
1163	/* Is object pointed to by @data of @size already copied to our safe buffer? */
1164	static bool btf_show_obj_is_safe(struct btf_show *show, void *data, int size)
1165	{
1166	return data >= show->obj.data &&
1167	(data + size) < (show->obj.data + BTF_SHOW_OBJ_SAFE_SIZE);
1168	}
1169
1170	/*
1171	* If object pointed to by @data of @size falls within our safe buffer, return
1172	* the equivalent pointer to the same safe data. Assumes
1173	* copy_from_kernel_nofault() has already happened and our safe buffer is
1174	* populated.
1175	*/
1176	static void *__btf_show_obj_safe(struct btf_show *show, void *data, int size)
1177	{
1178	if (btf_show_obj_is_safe(show, data, size))
1179	return show->obj.safe + (data - show->obj.data);
1180	return NULL;
1181	}
1182
1183	/*
1184	* Return a safe-to-access version of data pointed to by @data.
1185	* We do this by copying the relevant amount of information
1186	* to the struct btf_show obj.safe buffer using copy_from_kernel_nofault().
1187	*
1188	* If BTF_SHOW_UNSAFE is specified, just return data as-is; no
1189	* safe copy is needed.
1190	*
1191	* Otherwise we need to determine if we have the required amount
1192	* of data (determined by the @data pointer and the size of the
1193	* largest base type we can encounter (represented by
1194	* BTF_SHOW_OBJ_BASE_TYPE_SIZE). Having that much data ensures
1195	* that we will be able to print some of the current object,
1196	* and if more is needed a copy will be triggered.
1197	* Some objects such as structs will not fit into the buffer;
1198	* in such cases additional copies when we iterate over their
1199	* members may be needed.
1200	*
1201	* btf_show_obj_safe() is used to return a safe buffer for
1202	* btf_show_start_type(); this ensures that as we recurse into
1203	* nested types we always have safe data for the given type.
1204	* This approach is somewhat wasteful; it's possible for example
1205	* that when iterating over a large union we'll end up copying the
1206	* same data repeatedly, but the goal is safety not performance.
1207	* We use stack data as opposed to per-CPU buffers because the
1208	* iteration over a type can take some time, and preemption handling
1209	* would greatly complicate use of the safe buffer.
1210	*/
1211	static void *btf_show_obj_safe(struct btf_show *show,
1212	const struct btf_type *t,
1213	void *data)
1214	{
1215	const struct btf_type *rt;
1216	int size_left, size;
1217	void *safe = NULL;
1218
1219	if (show->flags & BTF_SHOW_UNSAFE)
1220	return data;
1221
1222	rt = btf_resolve_size(btf: show->btf, type: t, type_size: &size);
1223	if (IS_ERR(ptr: rt)) {
1224	show->state.status = PTR_ERR(ptr: rt);
1225	return NULL;
1226	}
1227
1228	/*
1229	* Is this toplevel object? If so, set total object size and
1230	* initialize pointers. Otherwise check if we still fall within
1231	* our safe object data.
1232	*/
1233	if (show->state.depth == 0) {
1234	show->obj.size = size;
1235	show->obj.head = data;
1236	} else {
1237	/*
1238	* If the size of the current object is > our remaining
1239	* safe buffer we _may_ need to do a new copy. However
1240	* consider the case of a nested struct; it's size pushes
1241	* us over the safe buffer limit, but showing any individual
1242	* struct members does not. In such cases, we don't need
1243	* to initiate a fresh copy yet; however we definitely need
1244	* at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes left
1245	* in our buffer, regardless of the current object size.
1246	* The logic here is that as we resolve types we will
1247	* hit a base type at some point, and we need to be sure
1248	* the next chunk of data is safely available to display
1249	* that type info safely. We cannot rely on the size of
1250	* the current object here because it may be much larger
1251	* than our current buffer (e.g. task_struct is 8k).
1252	* All we want to do here is ensure that we can print the
1253	* next basic type, which we can if either
1254	* - the current type size is within the safe buffer; or
1255	* - at least BTF_SHOW_OBJ_BASE_TYPE_SIZE bytes are left in
1256	* the safe buffer.
1257	*/
1258	safe = __btf_show_obj_safe(show, data,
1259	min(size,
1260	BTF_SHOW_OBJ_BASE_TYPE_SIZE));
1261	}
1262
1263	/*
1264	* We need a new copy to our safe object, either because we haven't
1265	* yet copied and are initializing safe data, or because the data
1266	* we want falls outside the boundaries of the safe object.
1267	*/
1268	if (!safe) {
1269	size_left = btf_show_obj_size_left(show, data);
1270	if (size_left > BTF_SHOW_OBJ_SAFE_SIZE)
1271	size_left = BTF_SHOW_OBJ_SAFE_SIZE;
1272	show->state.status = copy_from_kernel_nofault(dst: show->obj.safe,
1273	src: data, size: size_left);
1274	if (!show->state.status) {
1275	show->obj.data = data;
1276	safe = show->obj.safe;
1277	}
1278	}
1279
1280	return safe;
1281	}
1282
1283	/*
1284	* Set the type we are starting to show and return a safe data pointer
1285	* to be used for showing the associated data.
1286	*/
1287	static void *btf_show_start_type(struct btf_show *show,
1288	const struct btf_type *t,
1289	u32 type_id, void *data)
1290	{
1291	show->state.type = t;
1292	show->state.type_id = type_id;
1293	show->state.name[0] = '\0';
1294
1295	return btf_show_obj_safe(show, t, data);
1296	}
1297
1298	static void btf_show_end_type(struct btf_show *show)
1299	{
1300	show->state.type = NULL;
1301	show->state.type_id = 0;
1302	show->state.name[0] = '\0';
1303	}
1304
1305	static void *btf_show_start_aggr_type(struct btf_show *show,
1306	const struct btf_type *t,
1307	u32 type_id, void *data)
1308	{
1309	void *safe_data = btf_show_start_type(show, t, type_id, data);
1310
1311	if (!safe_data)
1312	return safe_data;
1313
1314	btf_show(show, fmt: "%s%s%s", btf_show_indent(show),
1315	btf_show_name(show),
1316	btf_show_newline(show));
1317	show->state.depth++;
1318	return safe_data;
1319	}
1320
1321	static void btf_show_end_aggr_type(struct btf_show *show,
1322	const char *suffix)
1323	{
1324	show->state.depth--;
1325	btf_show(show, fmt: "%s%s%s%s", btf_show_indent(show), suffix,
1326	btf_show_delim(show), btf_show_newline(show));
1327	btf_show_end_type(show);
1328	}
1329
1330	static void btf_show_start_member(struct btf_show *show,
1331	const struct btf_member *m)
1332	{
1333	show->state.member = m;
1334	}
1335
1336	static void btf_show_start_array_member(struct btf_show *show)
1337	{
1338	show->state.array_member = 1;
1339	btf_show_start_member(show, NULL);
1340	}
1341
1342	static void btf_show_end_member(struct btf_show *show)
1343	{
1344	show->state.member = NULL;
1345	}
1346
1347	static void btf_show_end_array_member(struct btf_show *show)
1348	{
1349	show->state.array_member = 0;
1350	btf_show_end_member(show);
1351	}
1352
1353	static void *btf_show_start_array_type(struct btf_show *show,
1354	const struct btf_type *t,
1355	u32 type_id,
1356	u16 array_encoding,
1357	void *data)
1358	{
1359	show->state.array_encoding = array_encoding;
1360	show->state.array_terminated = 0;
1361	return btf_show_start_aggr_type(show, t, type_id, data);
1362	}
1363
1364	static void btf_show_end_array_type(struct btf_show *show)
1365	{
1366	show->state.array_encoding = 0;
1367	show->state.array_terminated = 0;
1368	btf_show_end_aggr_type(show, suffix: "]");
1369	}
1370
1371	static void *btf_show_start_struct_type(struct btf_show *show,
1372	const struct btf_type *t,
1373	u32 type_id,
1374	void *data)
1375	{
1376	return btf_show_start_aggr_type(show, t, type_id, data);
1377	}
1378
1379	static void btf_show_end_struct_type(struct btf_show *show)
1380	{
1381	btf_show_end_aggr_type(show, suffix: "}");
1382	}
1383
1384	__printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log,
1385	const char *fmt, ...)
1386	{
1387	va_list args;
1388
1389	va_start(args, fmt);
1390	bpf_verifier_vlog(log, fmt, args);
1391	va_end(args);
1392	}
1393
1394	__printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env,
1395	const char *fmt, ...)
1396	{
1397	struct bpf_verifier_log *log = &env->log;
1398	va_list args;
1399
1400	if (!bpf_verifier_log_needed(log))
1401	return;
1402
1403	va_start(args, fmt);
1404	bpf_verifier_vlog(log, fmt, args);
1405	va_end(args);
1406	}
1407
1408	__printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
1409	const struct btf_type *t,
1410	bool log_details,
1411	const char *fmt, ...)
1412	{
1413	struct bpf_verifier_log *log = &env->log;
1414	struct btf *btf = env->btf;
1415	va_list args;
1416
1417	if (!bpf_verifier_log_needed(log))
1418	return;
1419
1420	if (log->level == BPF_LOG_KERNEL) {
1421	/* btf verifier prints all types it is processing via
1422	* btf_verifier_log_type(..., fmt = NULL).
1423	* Skip those prints for in-kernel BTF verification.
1424	*/
1425	if (!fmt)
1426	return;
1427
1428	/* Skip logging when loading module BTF with mismatches permitted */
1429	if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH))
1430	return;
1431	}
1432
1433	__btf_verifier_log(log, fmt: "[%u] %s %s%s",
1434	env->log_type_id,
1435	btf_type_str(t),
1436	__btf_name_by_offset(btf, offset: t->name_off),
1437	log_details ? " " : "");
1438
1439	if (log_details)
1440	btf_type_ops(t)->log_details(env, t);
1441
1442	if (fmt && *fmt) {
1443	__btf_verifier_log(log, fmt: " ");
1444	va_start(args, fmt);
1445	bpf_verifier_vlog(log, fmt, args);
1446	va_end(args);
1447	}
1448
1449	__btf_verifier_log(log, fmt: "\n");
1450	}
1451
1452	#define btf_verifier_log_type(env, t, ...) \
1453	__btf_verifier_log_type((env), (t), true, __VA_ARGS__)
1454	#define btf_verifier_log_basic(env, t, ...) \
1455	__btf_verifier_log_type((env), (t), false, __VA_ARGS__)
1456
1457	__printf(4, 5)
1458	static void btf_verifier_log_member(struct btf_verifier_env *env,
1459	const struct btf_type *struct_type,
1460	const struct btf_member *member,
1461	const char *fmt, ...)
1462	{
1463	struct bpf_verifier_log *log = &env->log;
1464	struct btf *btf = env->btf;
1465	va_list args;
1466
1467	if (!bpf_verifier_log_needed(log))
1468	return;
1469
1470	if (log->level == BPF_LOG_KERNEL) {
1471	if (!fmt)
1472	return;
1473
1474	/* Skip logging when loading module BTF with mismatches permitted */
1475	if (env->btf->base_btf && IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH))
1476	return;
1477	}
1478
1479	/* The CHECK_META phase already did a btf dump.
1480	*
1481	* If member is logged again, it must hit an error in
1482	* parsing this member. It is useful to print out which
1483	* struct this member belongs to.
1484	*/
1485	if (env->phase != CHECK_META)
1486	btf_verifier_log_type(env, struct_type, NULL);
1487
1488	if (btf_type_kflag(t: struct_type))
1489	__btf_verifier_log(log,
1490	fmt: "\t%s type_id=%u bitfield_size=%u bits_offset=%u",
1491	__btf_name_by_offset(btf, offset: member->name_off),
1492	member->type,
1493	BTF_MEMBER_BITFIELD_SIZE(member->offset),
1494	BTF_MEMBER_BIT_OFFSET(member->offset));
1495	else
1496	__btf_verifier_log(log, fmt: "\t%s type_id=%u bits_offset=%u",
1497	__btf_name_by_offset(btf, offset: member->name_off),
1498	member->type, member->offset);
1499
1500	if (fmt && *fmt) {
1501	__btf_verifier_log(log, fmt: " ");
1502	va_start(args, fmt);
1503	bpf_verifier_vlog(log, fmt, args);
1504	va_end(args);
1505	}
1506
1507	__btf_verifier_log(log, fmt: "\n");
1508	}
1509
1510	__printf(4, 5)
1511	static void btf_verifier_log_vsi(struct btf_verifier_env *env,
1512	const struct btf_type *datasec_type,
1513	const struct btf_var_secinfo *vsi,
1514	const char *fmt, ...)
1515	{
1516	struct bpf_verifier_log *log = &env->log;
1517	va_list args;
1518
1519	if (!bpf_verifier_log_needed(log))
1520	return;
1521	if (log->level == BPF_LOG_KERNEL && !fmt)
1522	return;
1523	if (env->phase != CHECK_META)
1524	btf_verifier_log_type(env, datasec_type, NULL);
1525
1526	__btf_verifier_log(log, fmt: "\t type_id=%u offset=%u size=%u",
1527	vsi->type, vsi->offset, vsi->size);
1528	if (fmt && *fmt) {
1529	__btf_verifier_log(log, fmt: " ");
1530	va_start(args, fmt);
1531	bpf_verifier_vlog(log, fmt, args);
1532	va_end(args);
1533	}
1534
1535	__btf_verifier_log(log, fmt: "\n");
1536	}
1537
1538	static void btf_verifier_log_hdr(struct btf_verifier_env *env,
1539	u32 btf_data_size)
1540	{
1541	struct bpf_verifier_log *log = &env->log;
1542	const struct btf *btf = env->btf;
1543	const struct btf_header *hdr;
1544
1545	if (!bpf_verifier_log_needed(log))
1546	return;
1547
1548	if (log->level == BPF_LOG_KERNEL)
1549	return;
1550	hdr = &btf->hdr;
1551	__btf_verifier_log(log, fmt: "magic: 0x%x\n", hdr->magic);
1552	__btf_verifier_log(log, fmt: "version: %u\n", hdr->version);
1553	__btf_verifier_log(log, fmt: "flags: 0x%x\n", hdr->flags);
1554	__btf_verifier_log(log, fmt: "hdr_len: %u\n", hdr->hdr_len);
1555	__btf_verifier_log(log, fmt: "type_off: %u\n", hdr->type_off);
1556	__btf_verifier_log(log, fmt: "type_len: %u\n", hdr->type_len);
1557	__btf_verifier_log(log, fmt: "str_off: %u\n", hdr->str_off);
1558	__btf_verifier_log(log, fmt: "str_len: %u\n", hdr->str_len);
1559	__btf_verifier_log(log, fmt: "btf_total_size: %u\n", btf_data_size);
1560	}
1561
1562	static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t)
1563	{
1564	struct btf *btf = env->btf;
1565
1566	if (btf->types_size == btf->nr_types) {
1567	/* Expand 'types' array */
1568
1569	struct btf_type **new_types;
1570	u32 expand_by, new_size;
1571
1572	if (btf->start_id + btf->types_size == BTF_MAX_TYPE) {
1573	btf_verifier_log(env, fmt: "Exceeded max num of types");
1574	return -E2BIG;
1575	}
1576
1577	expand_by = max_t(u32, btf->types_size >> 2, 16);
1578	new_size = min_t(u32, BTF_MAX_TYPE,
1579	btf->types_size + expand_by);
1580
1581	new_types = kvcalloc(n: new_size, size: sizeof(*new_types),
1582	GFP_KERNEL | __GFP_NOWARN);
1583	if (!new_types)
1584	return -ENOMEM;
1585
1586	if (btf->nr_types == 0) {
1587	if (!btf->base_btf) {
1588	/* lazily init VOID type */
1589	new_types[0] = &btf_void;
1590	btf->nr_types++;
1591	}
1592	} else {
1593	memcpy(new_types, btf->types,
1594	sizeof(*btf->types) * btf->nr_types);
1595	}
1596
1597	kvfree(addr: btf->types);
1598	btf->types = new_types;
1599	btf->types_size = new_size;
1600	}
1601
1602	btf->types[btf->nr_types++] = t;
1603
1604	return 0;
1605	}
1606
1607	static int btf_alloc_id(struct btf *btf)
1608	{
1609	int id;
1610
1611	idr_preload(GFP_KERNEL);
1612	spin_lock_bh(lock: &btf_idr_lock);
1613	id = idr_alloc_cyclic(&btf_idr, ptr: btf, start: 1, INT_MAX, GFP_ATOMIC);
1614	if (id > 0)
1615	btf->id = id;
1616	spin_unlock_bh(lock: &btf_idr_lock);
1617	idr_preload_end();
1618
1619	if (WARN_ON_ONCE(!id))
1620	return -ENOSPC;
1621
1622	return id > 0 ? 0 : id;
1623	}
1624
1625	static void btf_free_id(struct btf *btf)
1626	{
1627	unsigned long flags;
1628
1629	/*
1630	* In map-in-map, calling map_delete_elem() on outer
1631	* map will call bpf_map_put on the inner map.
1632	* It will then eventually call btf_free_id()
1633	* on the inner map. Some of the map_delete_elem()
1634	* implementation may have irq disabled, so
1635	* we need to use the _irqsave() version instead
1636	* of the _bh() version.
1637	*/
1638	spin_lock_irqsave(&btf_idr_lock, flags);
1639	idr_remove(&btf_idr, id: btf->id);
1640	spin_unlock_irqrestore(lock: &btf_idr_lock, flags);
1641	}
1642
1643	static void btf_free_kfunc_set_tab(struct btf *btf)
1644	{
1645	struct btf_kfunc_set_tab *tab = btf->kfunc_set_tab;
1646	int hook;
1647
1648	if (!tab)
1649	return;
1650	/* For module BTF, we directly assign the sets being registered, so
1651	* there is nothing to free except kfunc_set_tab.
1652	*/
1653	if (btf_is_module(btf))
1654	goto free_tab;
1655	for (hook = 0; hook < ARRAY_SIZE(tab->sets); hook++)
1656	kfree(objp: tab->sets[hook]);
1657	free_tab:
1658	kfree(objp: tab);
1659	btf->kfunc_set_tab = NULL;
1660	}
1661
1662	static void btf_free_dtor_kfunc_tab(struct btf *btf)
1663	{
1664	struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab;
1665
1666	if (!tab)
1667	return;
1668	kfree(objp: tab);
1669	btf->dtor_kfunc_tab = NULL;
1670	}
1671
1672	static void btf_struct_metas_free(struct btf_struct_metas *tab)
1673	{
1674	int i;
1675
1676	if (!tab)
1677	return;
1678	for (i = 0; i < tab->cnt; i++)
1679	btf_record_free(rec: tab->types[i].record);
1680	kfree(objp: tab);
1681	}
1682
1683	static void btf_free_struct_meta_tab(struct btf *btf)
1684	{
1685	struct btf_struct_metas *tab = btf->struct_meta_tab;
1686
1687	btf_struct_metas_free(tab);
1688	btf->struct_meta_tab = NULL;
1689	}
1690
1691	static void btf_free(struct btf *btf)
1692	{
1693	btf_free_struct_meta_tab(btf);
1694	btf_free_dtor_kfunc_tab(btf);
1695	btf_free_kfunc_set_tab(btf);
1696	kvfree(addr: btf->types);
1697	kvfree(addr: btf->resolved_sizes);
1698	kvfree(addr: btf->resolved_ids);
1699	kvfree(addr: btf->data);
1700	kfree(objp: btf);
1701	}
1702
1703	static void btf_free_rcu(struct rcu_head *rcu)
1704	{
1705	struct btf *btf = container_of(rcu, struct btf, rcu);
1706
1707	btf_free(btf);
1708	}
1709
1710	void btf_get(struct btf *btf)
1711	{
1712	refcount_inc(r: &btf->refcnt);
1713	}
1714
1715	void btf_put(struct btf *btf)
1716	{
1717	if (btf && refcount_dec_and_test(r: &btf->refcnt)) {
1718	btf_free_id(btf);
1719	call_rcu(head: &btf->rcu, func: btf_free_rcu);
1720	}
1721	}
1722
1723	static int env_resolve_init(struct btf_verifier_env *env)
1724	{
1725	struct btf *btf = env->btf;
1726	u32 nr_types = btf->nr_types;
1727	u32 *resolved_sizes = NULL;
1728	u32 *resolved_ids = NULL;
1729	u8 *visit_states = NULL;
1730
1731	resolved_sizes = kvcalloc(n: nr_types, size: sizeof(*resolved_sizes),
1732	GFP_KERNEL | __GFP_NOWARN);
1733	if (!resolved_sizes)
1734	goto nomem;
1735
1736	resolved_ids = kvcalloc(n: nr_types, size: sizeof(*resolved_ids),
1737	GFP_KERNEL | __GFP_NOWARN);
1738	if (!resolved_ids)
1739	goto nomem;
1740
1741	visit_states = kvcalloc(n: nr_types, size: sizeof(*visit_states),
1742	GFP_KERNEL | __GFP_NOWARN);
1743	if (!visit_states)
1744	goto nomem;
1745
1746	btf->resolved_sizes = resolved_sizes;
1747	btf->resolved_ids = resolved_ids;
1748	env->visit_states = visit_states;
1749
1750	return 0;
1751
1752	nomem:
1753	kvfree(addr: resolved_sizes);
1754	kvfree(addr: resolved_ids);
1755	kvfree(addr: visit_states);
1756	return -ENOMEM;
1757	}
1758
1759	static void btf_verifier_env_free(struct btf_verifier_env *env)
1760	{
1761	kvfree(addr: env->visit_states);
1762	kfree(objp: env);
1763	}
1764
1765	static bool env_type_is_resolve_sink(const struct btf_verifier_env *env,
1766	const struct btf_type *next_type)
1767	{
1768	switch (env->resolve_mode) {
1769	case RESOLVE_TBD:
1770	/* int, enum or void is a sink */
1771	return !btf_type_needs_resolve(t: next_type);
1772	case RESOLVE_PTR:
1773	/* int, enum, void, struct, array, func or func_proto is a sink
1774	* for ptr
1775	*/
1776	return !btf_type_is_modifier(t: next_type) &&
1777	!btf_type_is_ptr(t: next_type);
1778	case RESOLVE_STRUCT_OR_ARRAY:
1779	/* int, enum, void, ptr, func or func_proto is a sink
1780	* for struct and array
1781	*/
1782	return !btf_type_is_modifier(t: next_type) &&
1783	!btf_type_is_array(t: next_type) &&
1784	!btf_type_is_struct(t: next_type);
1785	default:
1786	BUG();
1787	}
1788	}
1789
1790	static bool env_type_is_resolved(const struct btf_verifier_env *env,
1791	u32 type_id)
1792	{
1793	/* base BTF types should be resolved by now */
1794	if (type_id < env->btf->start_id)
1795	return true;
1796
1797	return env->visit_states[type_id - env->btf->start_id] == RESOLVED;
1798	}
1799
1800	static int env_stack_push(struct btf_verifier_env *env,
1801	const struct btf_type *t, u32 type_id)
1802	{
1803	const struct btf *btf = env->btf;
1804	struct resolve_vertex *v;
1805
1806	if (env->top_stack == MAX_RESOLVE_DEPTH)
1807	return -E2BIG;
1808
1809	if (type_id < btf->start_id
1810	|| env->visit_states[type_id - btf->start_id] != NOT_VISITED)
1811	return -EEXIST;
1812
1813	env->visit_states[type_id - btf->start_id] = VISITED;
1814
1815	v = &env->stack[env->top_stack++];
1816	v->t = t;
1817	v->type_id = type_id;
1818	v->next_member = 0;
1819
1820	if (env->resolve_mode == RESOLVE_TBD) {
1821	if (btf_type_is_ptr(t))
1822	env->resolve_mode = RESOLVE_PTR;
1823	else if (btf_type_is_struct(t) || btf_type_is_array(t))
1824	env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY;
1825	}
1826
1827	return 0;
1828	}
1829
1830	static void env_stack_set_next_member(struct btf_verifier_env *env,
1831	u16 next_member)
1832	{
1833	env->stack[env->top_stack - 1].next_member = next_member;
1834	}
1835
1836	static void env_stack_pop_resolved(struct btf_verifier_env *env,
1837	u32 resolved_type_id,
1838	u32 resolved_size)
1839	{
1840	u32 type_id = env->stack[--(env->top_stack)].type_id;
1841	struct btf *btf = env->btf;
1842
1843	type_id -= btf->start_id; /* adjust to local type id */
1844	btf->resolved_sizes[type_id] = resolved_size;
1845	btf->resolved_ids[type_id] = resolved_type_id;
1846	env->visit_states[type_id] = RESOLVED;
1847	}
1848
1849	static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
1850	{
1851	return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
1852	}
1853
1854	/* Resolve the size of a passed-in "type"
1855	*
1856	* type: is an array (e.g. u32 array[x][y])
1857	* return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
1858	* *type_size: (x * y * sizeof(u32)). Hence, *type_size always
1859	* corresponds to the return type.
1860	* *elem_type: u32
1861	* *elem_id: id of u32
1862	* *total_nelems: (x * y). Hence, individual elem size is
1863	* (*type_size / *total_nelems)
1864	* *type_id: id of type if it's changed within the function, 0 if not
1865	*
1866	* type: is not an array (e.g. const struct X)
1867	* return type: type "struct X"
1868	* *type_size: sizeof(struct X)
1869	* *elem_type: same as return type ("struct X")
1870	* *elem_id: 0
1871	* *total_nelems: 1
1872	* *type_id: id of type if it's changed within the function, 0 if not
1873	*/
1874	static const struct btf_type *
1875	__btf_resolve_size(const struct btf *btf, const struct btf_type *type,
1876	u32 *type_size, const struct btf_type **elem_type,
1877	u32 *elem_id, u32 *total_nelems, u32 *type_id)
1878	{
1879	const struct btf_type *array_type = NULL;
1880	const struct btf_array *array = NULL;
1881	u32 i, size, nelems = 1, id = 0;
1882
1883	for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
1884	switch (BTF_INFO_KIND(type->info)) {
1885	/* type->size can be used */
1886	case BTF_KIND_INT:
1887	case BTF_KIND_STRUCT:
1888	case BTF_KIND_UNION:
1889	case BTF_KIND_ENUM:
1890	case BTF_KIND_FLOAT:
1891	case BTF_KIND_ENUM64:
1892	size = type->size;
1893	goto resolved;
1894
1895	case BTF_KIND_PTR:
1896	size = sizeof(void *);
1897	goto resolved;
1898
1899	/* Modifiers */
1900	case BTF_KIND_TYPEDEF:
1901	case BTF_KIND_VOLATILE:
1902	case BTF_KIND_CONST:
1903	case BTF_KIND_RESTRICT:
1904	case BTF_KIND_TYPE_TAG:
1905	id = type->type;
1906	type = btf_type_by_id(btf, type->type);
1907	break;
1908
1909	case BTF_KIND_ARRAY:
1910	if (!array_type)
1911	array_type = type;
1912	array = btf_type_array(t: type);
1913	if (nelems && array->nelems > U32_MAX / nelems)
1914	return ERR_PTR(error: -EINVAL);
1915	nelems *= array->nelems;
1916	type = btf_type_by_id(btf, array->type);
1917	break;
1918
1919	/* type without size */
1920	default:
1921	return ERR_PTR(error: -EINVAL);
1922	}
1923	}
1924
1925	return ERR_PTR(error: -EINVAL);
1926
1927	resolved:
1928	if (nelems && size > U32_MAX / nelems)
1929	return ERR_PTR(error: -EINVAL);
1930
1931	*type_size = nelems * size;
1932	if (total_nelems)
1933	*total_nelems = nelems;
1934	if (elem_type)
1935	*elem_type = type;
1936	if (elem_id)
1937	*elem_id = array ? array->type : 0;
1938	if (type_id && id)
1939	*type_id = id;
1940
1941	return array_type ? : type;
1942	}
1943
1944	const struct btf_type *
1945	btf_resolve_size(const struct btf *btf, const struct btf_type *type,
1946	u32 *type_size)
1947	{
1948	return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);
1949	}
1950
1951	static u32 btf_resolved_type_id(const struct btf *btf, u32 type_id)
1952	{
1953	while (type_id < btf->start_id)
1954	btf = btf->base_btf;
1955
1956	return btf->resolved_ids[type_id - btf->start_id];
1957	}
1958
1959	/* The input param "type_id" must point to a needs_resolve type */
1960	static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
1961	u32 *type_id)
1962	{
1963	*type_id = btf_resolved_type_id(btf, type_id: *type_id);
1964	return btf_type_by_id(btf, *type_id);
1965	}
1966
1967	static u32 btf_resolved_type_size(const struct btf *btf, u32 type_id)
1968	{
1969	while (type_id < btf->start_id)
1970	btf = btf->base_btf;
1971
1972	return btf->resolved_sizes[type_id - btf->start_id];
1973	}
1974
1975	const struct btf_type *btf_type_id_size(const struct btf *btf,
1976	u32 *type_id, u32 *ret_size)
1977	{
1978	const struct btf_type *size_type;
1979	u32 size_type_id = *type_id;
1980	u32 size = 0;
1981
1982	size_type = btf_type_by_id(btf, size_type_id);
1983	if (btf_type_nosize_or_null(t: size_type))
1984	return NULL;
1985
1986	if (btf_type_has_size(t: size_type)) {
1987	size = size_type->size;
1988	} else if (btf_type_is_array(t: size_type)) {
1989	size = btf_resolved_type_size(btf, type_id: size_type_id);
1990	} else if (btf_type_is_ptr(t: size_type)) {
1991	size = sizeof(void *);
1992	} else {
1993	if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
1994	!btf_type_is_var(size_type)))
1995	return NULL;
1996
1997	size_type_id = btf_resolved_type_id(btf, type_id: size_type_id);
1998	size_type = btf_type_by_id(btf, size_type_id);
1999	if (btf_type_nosize_or_null(t: size_type))
2000	return NULL;
2001	else if (btf_type_has_size(t: size_type))
2002	size = size_type->size;
2003	else if (btf_type_is_array(t: size_type))
2004	size = btf_resolved_type_size(btf, type_id: size_type_id);
2005	else if (btf_type_is_ptr(t: size_type))
2006	size = sizeof(void *);
2007	else
2008	return NULL;
2009	}
2010
2011	*type_id = size_type_id;
2012	if (ret_size)
2013	*ret_size = size;
2014
2015	return size_type;
2016	}
2017
2018	static int btf_df_check_member(struct btf_verifier_env *env,
2019	const struct btf_type *struct_type,
2020	const struct btf_member *member,
2021	const struct btf_type *member_type)
2022	{
2023	btf_verifier_log_basic(env, struct_type,
2024	"Unsupported check_member");
2025	return -EINVAL;
2026	}
2027
2028	static int btf_df_check_kflag_member(struct btf_verifier_env *env,
2029	const struct btf_type *struct_type,
2030	const struct btf_member *member,
2031	const struct btf_type *member_type)
2032	{
2033	btf_verifier_log_basic(env, struct_type,
2034	"Unsupported check_kflag_member");
2035	return -EINVAL;
2036	}
2037
2038	/* Used for ptr, array struct/union and float type members.
2039	* int, enum and modifier types have their specific callback functions.
2040	*/
2041	static int btf_generic_check_kflag_member(struct btf_verifier_env *env,
2042	const struct btf_type *struct_type,
2043	const struct btf_member *member,
2044	const struct btf_type *member_type)
2045	{
2046	if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) {
2047	btf_verifier_log_member(env, struct_type, member,
2048	fmt: "Invalid member bitfield_size");
2049	return -EINVAL;
2050	}
2051
2052	/* bitfield size is 0, so member->offset represents bit offset only.
2053	* It is safe to call non kflag check_member variants.
2054	*/
2055	return btf_type_ops(t: member_type)->check_member(env, struct_type,
2056	member,
2057	member_type);
2058	}
2059
2060	static int btf_df_resolve(struct btf_verifier_env *env,
2061	const struct resolve_vertex *v)
2062	{
2063	btf_verifier_log_basic(env, v->t, "Unsupported resolve");
2064	return -EINVAL;
2065	}
2066
2067	static void btf_df_show(const struct btf *btf, const struct btf_type *t,
2068	u32 type_id, void *data, u8 bits_offsets,
2069	struct btf_show *show)
2070	{
2071	btf_show(show, fmt: "<unsupported kind:%u>", BTF_INFO_KIND(t->info));
2072	}
2073
2074	static int btf_int_check_member(struct btf_verifier_env *env,
2075	const struct btf_type *struct_type,
2076	const struct btf_member *member,
2077	const struct btf_type *member_type)
2078	{
2079	u32 int_data = btf_type_int(t: member_type);
2080	u32 struct_bits_off = member->offset;
2081	u32 struct_size = struct_type->size;
2082	u32 nr_copy_bits;
2083	u32 bytes_offset;
2084
2085	if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) {
2086	btf_verifier_log_member(env, struct_type, member,
2087	fmt: "bits_offset exceeds U32_MAX");
2088	return -EINVAL;
2089	}
2090
2091	struct_bits_off += BTF_INT_OFFSET(int_data);
2092	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2093	nr_copy_bits = BTF_INT_BITS(int_data) +
2094	BITS_PER_BYTE_MASKED(struct_bits_off);
2095
2096	if (nr_copy_bits > BITS_PER_U128) {
2097	btf_verifier_log_member(env, struct_type, member,
2098	fmt: "nr_copy_bits exceeds 128");
2099	return -EINVAL;
2100	}
2101
2102	if (struct_size < bytes_offset ||
2103	struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
2104	btf_verifier_log_member(env, struct_type, member,
2105	fmt: "Member exceeds struct_size");
2106	return -EINVAL;
2107	}
2108
2109	return 0;
2110	}
2111
2112	static int btf_int_check_kflag_member(struct btf_verifier_env *env,
2113	const struct btf_type *struct_type,
2114	const struct btf_member *member,
2115	const struct btf_type *member_type)
2116	{
2117	u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset;
2118	u32 int_data = btf_type_int(t: member_type);
2119	u32 struct_size = struct_type->size;
2120	u32 nr_copy_bits;
2121
2122	/* a regular int type is required for the kflag int member */
2123	if (!btf_type_int_is_regular(t: member_type)) {
2124	btf_verifier_log_member(env, struct_type, member,
2125	fmt: "Invalid member base type");
2126	return -EINVAL;
2127	}
2128
2129	/* check sanity of bitfield size */
2130	nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
2131	struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
2132	nr_int_data_bits = BTF_INT_BITS(int_data);
2133	if (!nr_bits) {
2134	/* Not a bitfield member, member offset must be at byte
2135	* boundary.
2136	*/
2137	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2138	btf_verifier_log_member(env, struct_type, member,
2139	fmt: "Invalid member offset");
2140	return -EINVAL;
2141	}
2142
2143	nr_bits = nr_int_data_bits;
2144	} else if (nr_bits > nr_int_data_bits) {
2145	btf_verifier_log_member(env, struct_type, member,
2146	fmt: "Invalid member bitfield_size");
2147	return -EINVAL;
2148	}
2149
2150	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2151	nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off);
2152	if (nr_copy_bits > BITS_PER_U128) {
2153	btf_verifier_log_member(env, struct_type, member,
2154	fmt: "nr_copy_bits exceeds 128");
2155	return -EINVAL;
2156	}
2157
2158	if (struct_size < bytes_offset ||
2159	struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) {
2160	btf_verifier_log_member(env, struct_type, member,
2161	fmt: "Member exceeds struct_size");
2162	return -EINVAL;
2163	}
2164
2165	return 0;
2166	}
2167
2168	static s32 btf_int_check_meta(struct btf_verifier_env *env,
2169	const struct btf_type *t,
2170	u32 meta_left)
2171	{
2172	u32 int_data, nr_bits, meta_needed = sizeof(int_data);
2173	u16 encoding;
2174
2175	if (meta_left < meta_needed) {
2176	btf_verifier_log_basic(env, t,
2177	"meta_left:%u meta_needed:%u",
2178	meta_left, meta_needed);
2179	return -EINVAL;
2180	}
2181
2182	if (btf_type_vlen(t)) {
2183	btf_verifier_log_type(env, t, "vlen != 0");
2184	return -EINVAL;
2185	}
2186
2187	if (btf_type_kflag(t)) {
2188	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2189	return -EINVAL;
2190	}
2191
2192	int_data = btf_type_int(t);
2193	if (int_data & ~BTF_INT_MASK) {
2194	btf_verifier_log_basic(env, t, "Invalid int_data:%x",
2195	int_data);
2196	return -EINVAL;
2197	}
2198
2199	nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data);
2200
2201	if (nr_bits > BITS_PER_U128) {
2202	btf_verifier_log_type(env, t, "nr_bits exceeds %zu",
2203	BITS_PER_U128);
2204	return -EINVAL;
2205	}
2206
2207	if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) {
2208	btf_verifier_log_type(env, t, "nr_bits exceeds type_size");
2209	return -EINVAL;
2210	}
2211
2212	/*
2213	* Only one of the encoding bits is allowed and it
2214	* should be sufficient for the pretty print purpose (i.e. decoding).
2215	* Multiple bits can be allowed later if it is found
2216	* to be insufficient.
2217	*/
2218	encoding = BTF_INT_ENCODING(int_data);
2219	if (encoding &&
2220	encoding != BTF_INT_SIGNED &&
2221	encoding != BTF_INT_CHAR &&
2222	encoding != BTF_INT_BOOL) {
2223	btf_verifier_log_type(env, t, "Unsupported encoding");
2224	return -ENOTSUPP;
2225	}
2226
2227	btf_verifier_log_type(env, t, NULL);
2228
2229	return meta_needed;
2230	}
2231
2232	static void btf_int_log(struct btf_verifier_env *env,
2233	const struct btf_type *t)
2234	{
2235	int int_data = btf_type_int(t);
2236
2237	btf_verifier_log(env,
2238	fmt: "size=%u bits_offset=%u nr_bits=%u encoding=%s",
2239	t->size, BTF_INT_OFFSET(int_data),
2240	BTF_INT_BITS(int_data),
2241	btf_int_encoding_str(BTF_INT_ENCODING(int_data)));
2242	}
2243
2244	static void btf_int128_print(struct btf_show *show, void *data)
2245	{
2246	/* data points to a __int128 number.
2247	* Suppose
2248	* int128_num = *(__int128 *)data;
2249	* The below formulas shows what upper_num and lower_num represents:
2250	* upper_num = int128_num >> 64;
2251	* lower_num = int128_num & 0xffffffffFFFFFFFFULL;
2252	*/
2253	u64 upper_num, lower_num;
2254
2255	#ifdef __BIG_ENDIAN_BITFIELD
2256	upper_num = *(u64 *)data;
2257	lower_num = *(u64 *)(data + 8);
2258	#else
2259	upper_num = *(u64 *)(data + 8);
2260	lower_num = *(u64 *)data;
2261	#endif
2262	if (upper_num == 0)
2263	btf_show_type_value(show, "0x%llx", lower_num);
2264	else
2265	btf_show_type_values(show, "0x%llx%016llx", upper_num,
2266	lower_num);
2267	}
2268
2269	static void btf_int128_shift(u64 *print_num, u16 left_shift_bits,
2270	u16 right_shift_bits)
2271	{
2272	u64 upper_num, lower_num;
2273
2274	#ifdef __BIG_ENDIAN_BITFIELD
2275	upper_num = print_num[0];
2276	lower_num = print_num[1];
2277	#else
2278	upper_num = print_num[1];
2279	lower_num = print_num[0];
2280	#endif
2281
2282	/* shake out un-needed bits by shift/or operations */
2283	if (left_shift_bits >= 64) {
2284	upper_num = lower_num << (left_shift_bits - 64);
2285	lower_num = 0;
2286	} else {
2287	upper_num = (upper_num << left_shift_bits) |
2288	(lower_num >> (64 - left_shift_bits));
2289	lower_num = lower_num << left_shift_bits;
2290	}
2291
2292	if (right_shift_bits >= 64) {
2293	lower_num = upper_num >> (right_shift_bits - 64);
2294	upper_num = 0;
2295	} else {
2296	lower_num = (lower_num >> right_shift_bits) |
2297	(upper_num << (64 - right_shift_bits));
2298	upper_num = upper_num >> right_shift_bits;
2299	}
2300
2301	#ifdef __BIG_ENDIAN_BITFIELD
2302	print_num[0] = upper_num;
2303	print_num[1] = lower_num;
2304	#else
2305	print_num[0] = lower_num;
2306	print_num[1] = upper_num;
2307	#endif
2308	}
2309
2310	static void btf_bitfield_show(void *data, u8 bits_offset,
2311	u8 nr_bits, struct btf_show *show)
2312	{
2313	u16 left_shift_bits, right_shift_bits;
2314	u8 nr_copy_bytes;
2315	u8 nr_copy_bits;
2316	u64 print_num[2] = {};
2317
2318	nr_copy_bits = nr_bits + bits_offset;
2319	nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits);
2320
2321	memcpy(print_num, data, nr_copy_bytes);
2322
2323	#ifdef __BIG_ENDIAN_BITFIELD
2324	left_shift_bits = bits_offset;
2325	#else
2326	left_shift_bits = BITS_PER_U128 - nr_copy_bits;
2327	#endif
2328	right_shift_bits = BITS_PER_U128 - nr_bits;
2329
2330	btf_int128_shift(print_num, left_shift_bits, right_shift_bits);
2331	btf_int128_print(show, data: print_num);
2332	}
2333
2334
2335	static void btf_int_bits_show(const struct btf *btf,
2336	const struct btf_type *t,
2337	void *data, u8 bits_offset,
2338	struct btf_show *show)
2339	{
2340	u32 int_data = btf_type_int(t);
2341	u8 nr_bits = BTF_INT_BITS(int_data);
2342	u8 total_bits_offset;
2343
2344	/*
2345	* bits_offset is at most 7.
2346	* BTF_INT_OFFSET() cannot exceed 128 bits.
2347	*/
2348	total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data);
2349	data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
2350	bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
2351	btf_bitfield_show(data, bits_offset, nr_bits, show);
2352	}
2353
2354	static void btf_int_show(const struct btf *btf, const struct btf_type *t,
2355	u32 type_id, void *data, u8 bits_offset,
2356	struct btf_show *show)
2357	{
2358	u32 int_data = btf_type_int(t);
2359	u8 encoding = BTF_INT_ENCODING(int_data);
2360	bool sign = encoding & BTF_INT_SIGNED;
2361	u8 nr_bits = BTF_INT_BITS(int_data);
2362	void *safe_data;
2363
2364	safe_data = btf_show_start_type(show, t, type_id, data);
2365	if (!safe_data)
2366	return;
2367
2368	if (bits_offset || BTF_INT_OFFSET(int_data) ||
2369	BITS_PER_BYTE_MASKED(nr_bits)) {
2370	btf_int_bits_show(btf, t, data: safe_data, bits_offset, show);
2371	goto out;
2372	}
2373
2374	switch (nr_bits) {
2375	case 128:
2376	btf_int128_print(show, data: safe_data);
2377	break;
2378	case 64:
2379	if (sign)
2380	btf_show_type_value(show, "%lld", *(s64 *)safe_data);
2381	else
2382	btf_show_type_value(show, "%llu", *(u64 *)safe_data);
2383	break;
2384	case 32:
2385	if (sign)
2386	btf_show_type_value(show, "%d", *(s32 *)safe_data);
2387	else
2388	btf_show_type_value(show, "%u", *(u32 *)safe_data);
2389	break;
2390	case 16:
2391	if (sign)
2392	btf_show_type_value(show, "%d", *(s16 *)safe_data);
2393	else
2394	btf_show_type_value(show, "%u", *(u16 *)safe_data);
2395	break;
2396	case 8:
2397	if (show->state.array_encoding == BTF_INT_CHAR) {
2398	/* check for null terminator */
2399	if (show->state.array_terminated)
2400	break;
2401	if (*(char *)data == '\0') {
2402	show->state.array_terminated = 1;
2403	break;
2404	}
2405	if (isprint(*(char *)data)) {
2406	btf_show_type_value(show, "'%c'",
2407	*(char *)safe_data);
2408	break;
2409	}
2410	}
2411	if (sign)
2412	btf_show_type_value(show, "%d", *(s8 *)safe_data);
2413	else
2414	btf_show_type_value(show, "%u", *(u8 *)safe_data);
2415	break;
2416	default:
2417	btf_int_bits_show(btf, t, data: safe_data, bits_offset, show);
2418	break;
2419	}
2420	out:
2421	btf_show_end_type(show);
2422	}
2423
2424	static const struct btf_kind_operations int_ops = {
2425	.check_meta = btf_int_check_meta,
2426	.resolve = btf_df_resolve,
2427	.check_member = btf_int_check_member,
2428	.check_kflag_member = btf_int_check_kflag_member,
2429	.log_details = btf_int_log,
2430	.show = btf_int_show,
2431	};
2432
2433	static int btf_modifier_check_member(struct btf_verifier_env *env,
2434	const struct btf_type *struct_type,
2435	const struct btf_member *member,
2436	const struct btf_type *member_type)
2437	{
2438	const struct btf_type *resolved_type;
2439	u32 resolved_type_id = member->type;
2440	struct btf_member resolved_member;
2441	struct btf *btf = env->btf;
2442
2443	resolved_type = btf_type_id_size(btf, type_id: &resolved_type_id, NULL);
2444	if (!resolved_type) {
2445	btf_verifier_log_member(env, struct_type, member,
2446	fmt: "Invalid member");
2447	return -EINVAL;
2448	}
2449
2450	resolved_member = *member;
2451	resolved_member.type = resolved_type_id;
2452
2453	return btf_type_ops(t: resolved_type)->check_member(env, struct_type,
2454	&resolved_member,
2455	resolved_type);
2456	}
2457
2458	static int btf_modifier_check_kflag_member(struct btf_verifier_env *env,
2459	const struct btf_type *struct_type,
2460	const struct btf_member *member,
2461	const struct btf_type *member_type)
2462	{
2463	const struct btf_type *resolved_type;
2464	u32 resolved_type_id = member->type;
2465	struct btf_member resolved_member;
2466	struct btf *btf = env->btf;
2467
2468	resolved_type = btf_type_id_size(btf, type_id: &resolved_type_id, NULL);
2469	if (!resolved_type) {
2470	btf_verifier_log_member(env, struct_type, member,
2471	fmt: "Invalid member");
2472	return -EINVAL;
2473	}
2474
2475	resolved_member = *member;
2476	resolved_member.type = resolved_type_id;
2477
2478	return btf_type_ops(t: resolved_type)->check_kflag_member(env, struct_type,
2479	&resolved_member,
2480	resolved_type);
2481	}
2482
2483	static int btf_ptr_check_member(struct btf_verifier_env *env,
2484	const struct btf_type *struct_type,
2485	const struct btf_member *member,
2486	const struct btf_type *member_type)
2487	{
2488	u32 struct_size, struct_bits_off, bytes_offset;
2489
2490	struct_size = struct_type->size;
2491	struct_bits_off = member->offset;
2492	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2493
2494	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2495	btf_verifier_log_member(env, struct_type, member,
2496	fmt: "Member is not byte aligned");
2497	return -EINVAL;
2498	}
2499
2500	if (struct_size - bytes_offset < sizeof(void *)) {
2501	btf_verifier_log_member(env, struct_type, member,
2502	fmt: "Member exceeds struct_size");
2503	return -EINVAL;
2504	}
2505
2506	return 0;
2507	}
2508
2509	static int btf_ref_type_check_meta(struct btf_verifier_env *env,
2510	const struct btf_type *t,
2511	u32 meta_left)
2512	{
2513	const char *value;
2514
2515	if (btf_type_vlen(t)) {
2516	btf_verifier_log_type(env, t, "vlen != 0");
2517	return -EINVAL;
2518	}
2519
2520	if (btf_type_kflag(t)) {
2521	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2522	return -EINVAL;
2523	}
2524
2525	if (!BTF_TYPE_ID_VALID(t->type)) {
2526	btf_verifier_log_type(env, t, "Invalid type_id");
2527	return -EINVAL;
2528	}
2529
2530	/* typedef/type_tag type must have a valid name, and other ref types,
2531	* volatile, const, restrict, should have a null name.
2532	*/
2533	if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) {
2534	if (!t->name_off ||
2535	!btf_name_valid_identifier(btf: env->btf, offset: t->name_off)) {
2536	btf_verifier_log_type(env, t, "Invalid name");
2537	return -EINVAL;
2538	}
2539	} else if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPE_TAG) {
2540	value = btf_name_by_offset(btf: env->btf, offset: t->name_off);
2541	if (!value || !value[0]) {
2542	btf_verifier_log_type(env, t, "Invalid name");
2543	return -EINVAL;
2544	}
2545	} else {
2546	if (t->name_off) {
2547	btf_verifier_log_type(env, t, "Invalid name");
2548	return -EINVAL;
2549	}
2550	}
2551
2552	btf_verifier_log_type(env, t, NULL);
2553
2554	return 0;
2555	}
2556
2557	static int btf_modifier_resolve(struct btf_verifier_env *env,
2558	const struct resolve_vertex *v)
2559	{
2560	const struct btf_type *t = v->t;
2561	const struct btf_type *next_type;
2562	u32 next_type_id = t->type;
2563	struct btf *btf = env->btf;
2564
2565	next_type = btf_type_by_id(btf, next_type_id);
2566	if (!next_type || btf_type_is_resolve_source_only(t: next_type)) {
2567	btf_verifier_log_type(env, v->t, "Invalid type_id");
2568	return -EINVAL;
2569	}
2570
2571	if (!env_type_is_resolve_sink(env, next_type) &&
2572	!env_type_is_resolved(env, type_id: next_type_id))
2573	return env_stack_push(env, t: next_type, type_id: next_type_id);
2574
2575	/* Figure out the resolved next_type_id with size.
2576	* They will be stored in the current modifier's
2577	* resolved_ids and resolved_sizes such that it can
2578	* save us a few type-following when we use it later (e.g. in
2579	* pretty print).
2580	*/
2581	if (!btf_type_id_size(btf, type_id: &next_type_id, NULL)) {
2582	if (env_type_is_resolved(env, type_id: next_type_id))
2583	next_type = btf_type_id_resolve(btf, type_id: &next_type_id);
2584
2585	/* "typedef void new_void", "const void"...etc */
2586	if (!btf_type_is_void(t: next_type) &&
2587	!btf_type_is_fwd(t: next_type) &&
2588	!btf_type_is_func_proto(t: next_type)) {
2589	btf_verifier_log_type(env, v->t, "Invalid type_id");
2590	return -EINVAL;
2591	}
2592	}
2593
2594	env_stack_pop_resolved(env, resolved_type_id: next_type_id, resolved_size: 0);
2595
2596	return 0;
2597	}
2598
2599	static int btf_var_resolve(struct btf_verifier_env *env,
2600	const struct resolve_vertex *v)
2601	{
2602	const struct btf_type *next_type;
2603	const struct btf_type *t = v->t;
2604	u32 next_type_id = t->type;
2605	struct btf *btf = env->btf;
2606
2607	next_type = btf_type_by_id(btf, next_type_id);
2608	if (!next_type || btf_type_is_resolve_source_only(t: next_type)) {
2609	btf_verifier_log_type(env, v->t, "Invalid type_id");
2610	return -EINVAL;
2611	}
2612
2613	if (!env_type_is_resolve_sink(env, next_type) &&
2614	!env_type_is_resolved(env, type_id: next_type_id))
2615	return env_stack_push(env, t: next_type, type_id: next_type_id);
2616
2617	if (btf_type_is_modifier(t: next_type)) {
2618	const struct btf_type *resolved_type;
2619	u32 resolved_type_id;
2620
2621	resolved_type_id = next_type_id;
2622	resolved_type = btf_type_id_resolve(btf, type_id: &resolved_type_id);
2623
2624	if (btf_type_is_ptr(t: resolved_type) &&
2625	!env_type_is_resolve_sink(env, next_type: resolved_type) &&
2626	!env_type_is_resolved(env, type_id: resolved_type_id))
2627	return env_stack_push(env, t: resolved_type,
2628	type_id: resolved_type_id);
2629	}
2630
2631	/* We must resolve to something concrete at this point, no
2632	* forward types or similar that would resolve to size of
2633	* zero is allowed.
2634	*/
2635	if (!btf_type_id_size(btf, type_id: &next_type_id, NULL)) {
2636	btf_verifier_log_type(env, v->t, "Invalid type_id");
2637	return -EINVAL;
2638	}
2639
2640	env_stack_pop_resolved(env, resolved_type_id: next_type_id, resolved_size: 0);
2641
2642	return 0;
2643	}
2644
2645	static int btf_ptr_resolve(struct btf_verifier_env *env,
2646	const struct resolve_vertex *v)
2647	{
2648	const struct btf_type *next_type;
2649	const struct btf_type *t = v->t;
2650	u32 next_type_id = t->type;
2651	struct btf *btf = env->btf;
2652
2653	next_type = btf_type_by_id(btf, next_type_id);
2654	if (!next_type || btf_type_is_resolve_source_only(t: next_type)) {
2655	btf_verifier_log_type(env, v->t, "Invalid type_id");
2656	return -EINVAL;
2657	}
2658
2659	if (!env_type_is_resolve_sink(env, next_type) &&
2660	!env_type_is_resolved(env, type_id: next_type_id))
2661	return env_stack_push(env, t: next_type, type_id: next_type_id);
2662
2663	/* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY,
2664	* the modifier may have stopped resolving when it was resolved
2665	* to a ptr (last-resolved-ptr).
2666	*
2667	* We now need to continue from the last-resolved-ptr to
2668	* ensure the last-resolved-ptr will not referring back to
2669	* the current ptr (t).
2670	*/
2671	if (btf_type_is_modifier(t: next_type)) {
2672	const struct btf_type *resolved_type;
2673	u32 resolved_type_id;
2674
2675	resolved_type_id = next_type_id;
2676	resolved_type = btf_type_id_resolve(btf, type_id: &resolved_type_id);
2677
2678	if (btf_type_is_ptr(t: resolved_type) &&
2679	!env_type_is_resolve_sink(env, next_type: resolved_type) &&
2680	!env_type_is_resolved(env, type_id: resolved_type_id))
2681	return env_stack_push(env, t: resolved_type,
2682	type_id: resolved_type_id);
2683	}
2684
2685	if (!btf_type_id_size(btf, type_id: &next_type_id, NULL)) {
2686	if (env_type_is_resolved(env, type_id: next_type_id))
2687	next_type = btf_type_id_resolve(btf, type_id: &next_type_id);
2688
2689	if (!btf_type_is_void(t: next_type) &&
2690	!btf_type_is_fwd(t: next_type) &&
2691	!btf_type_is_func_proto(t: next_type)) {
2692	btf_verifier_log_type(env, v->t, "Invalid type_id");
2693	return -EINVAL;
2694	}
2695	}
2696
2697	env_stack_pop_resolved(env, resolved_type_id: next_type_id, resolved_size: 0);
2698
2699	return 0;
2700	}
2701
2702	static void btf_modifier_show(const struct btf *btf,
2703	const struct btf_type *t,
2704	u32 type_id, void *data,
2705	u8 bits_offset, struct btf_show *show)
2706	{
2707	if (btf->resolved_ids)
2708	t = btf_type_id_resolve(btf, type_id: &type_id);
2709	else
2710	t = btf_type_skip_modifiers(btf, id: type_id, NULL);
2711
2712	btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
2713	}
2714
2715	static void btf_var_show(const struct btf *btf, const struct btf_type *t,
2716	u32 type_id, void *data, u8 bits_offset,
2717	struct btf_show *show)
2718	{
2719	t = btf_type_id_resolve(btf, type_id: &type_id);
2720
2721	btf_type_ops(t)->show(btf, t, type_id, data, bits_offset, show);
2722	}
2723
2724	static void btf_ptr_show(const struct btf *btf, const struct btf_type *t,
2725	u32 type_id, void *data, u8 bits_offset,
2726	struct btf_show *show)
2727	{
2728	void *safe_data;
2729
2730	safe_data = btf_show_start_type(show, t, type_id, data);
2731	if (!safe_data)
2732	return;
2733
2734	/* It is a hashed value unless BTF_SHOW_PTR_RAW is specified */
2735	if (show->flags & BTF_SHOW_PTR_RAW)
2736	btf_show_type_value(show, "0x%px", *(void **)safe_data);
2737	else
2738	btf_show_type_value(show, "0x%p", *(void **)safe_data);
2739	btf_show_end_type(show);
2740	}
2741
2742	static void btf_ref_type_log(struct btf_verifier_env *env,
2743	const struct btf_type *t)
2744	{
2745	btf_verifier_log(env, fmt: "type_id=%u", t->type);
2746	}
2747
2748	static struct btf_kind_operations modifier_ops = {
2749	.check_meta = btf_ref_type_check_meta,
2750	.resolve = btf_modifier_resolve,
2751	.check_member = btf_modifier_check_member,
2752	.check_kflag_member = btf_modifier_check_kflag_member,
2753	.log_details = btf_ref_type_log,
2754	.show = btf_modifier_show,
2755	};
2756
2757	static struct btf_kind_operations ptr_ops = {
2758	.check_meta = btf_ref_type_check_meta,
2759	.resolve = btf_ptr_resolve,
2760	.check_member = btf_ptr_check_member,
2761	.check_kflag_member = btf_generic_check_kflag_member,
2762	.log_details = btf_ref_type_log,
2763	.show = btf_ptr_show,
2764	};
2765
2766	static s32 btf_fwd_check_meta(struct btf_verifier_env *env,
2767	const struct btf_type *t,
2768	u32 meta_left)
2769	{
2770	if (btf_type_vlen(t)) {
2771	btf_verifier_log_type(env, t, "vlen != 0");
2772	return -EINVAL;
2773	}
2774
2775	if (t->type) {
2776	btf_verifier_log_type(env, t, "type != 0");
2777	return -EINVAL;
2778	}
2779
2780	/* fwd type must have a valid name */
2781	if (!t->name_off ||
2782	!btf_name_valid_identifier(btf: env->btf, offset: t->name_off)) {
2783	btf_verifier_log_type(env, t, "Invalid name");
2784	return -EINVAL;
2785	}
2786
2787	btf_verifier_log_type(env, t, NULL);
2788
2789	return 0;
2790	}
2791
2792	static void btf_fwd_type_log(struct btf_verifier_env *env,
2793	const struct btf_type *t)
2794	{
2795	btf_verifier_log(env, fmt: "%s", btf_type_kflag(t) ? "union" : "struct");
2796	}
2797
2798	static struct btf_kind_operations fwd_ops = {
2799	.check_meta = btf_fwd_check_meta,
2800	.resolve = btf_df_resolve,
2801	.check_member = btf_df_check_member,
2802	.check_kflag_member = btf_df_check_kflag_member,
2803	.log_details = btf_fwd_type_log,
2804	.show = btf_df_show,
2805	};
2806
2807	static int btf_array_check_member(struct btf_verifier_env *env,
2808	const struct btf_type *struct_type,
2809	const struct btf_member *member,
2810	const struct btf_type *member_type)
2811	{
2812	u32 struct_bits_off = member->offset;
2813	u32 struct_size, bytes_offset;
2814	u32 array_type_id, array_size;
2815	struct btf *btf = env->btf;
2816
2817	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
2818	btf_verifier_log_member(env, struct_type, member,
2819	fmt: "Member is not byte aligned");
2820	return -EINVAL;
2821	}
2822
2823	array_type_id = member->type;
2824	btf_type_id_size(btf, type_id: &array_type_id, ret_size: &array_size);
2825	struct_size = struct_type->size;
2826	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
2827	if (struct_size - bytes_offset < array_size) {
2828	btf_verifier_log_member(env, struct_type, member,
2829	fmt: "Member exceeds struct_size");
2830	return -EINVAL;
2831	}
2832
2833	return 0;
2834	}
2835
2836	static s32 btf_array_check_meta(struct btf_verifier_env *env,
2837	const struct btf_type *t,
2838	u32 meta_left)
2839	{
2840	const struct btf_array *array = btf_type_array(t);
2841	u32 meta_needed = sizeof(*array);
2842
2843	if (meta_left < meta_needed) {
2844	btf_verifier_log_basic(env, t,
2845	"meta_left:%u meta_needed:%u",
2846	meta_left, meta_needed);
2847	return -EINVAL;
2848	}
2849
2850	/* array type should not have a name */
2851	if (t->name_off) {
2852	btf_verifier_log_type(env, t, "Invalid name");
2853	return -EINVAL;
2854	}
2855
2856	if (btf_type_vlen(t)) {
2857	btf_verifier_log_type(env, t, "vlen != 0");
2858	return -EINVAL;
2859	}
2860
2861	if (btf_type_kflag(t)) {
2862	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
2863	return -EINVAL;
2864	}
2865
2866	if (t->size) {
2867	btf_verifier_log_type(env, t, "size != 0");
2868	return -EINVAL;
2869	}
2870
2871	/* Array elem type and index type cannot be in type void,
2872	* so !array->type and !array->index_type are not allowed.
2873	*/
2874	if (!array->type || !BTF_TYPE_ID_VALID(array->type)) {
2875	btf_verifier_log_type(env, t, "Invalid elem");
2876	return -EINVAL;
2877	}
2878
2879	if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) {
2880	btf_verifier_log_type(env, t, "Invalid index");
2881	return -EINVAL;
2882	}
2883
2884	btf_verifier_log_type(env, t, NULL);
2885
2886	return meta_needed;
2887	}
2888
2889	static int btf_array_resolve(struct btf_verifier_env *env,
2890	const struct resolve_vertex *v)
2891	{
2892	const struct btf_array *array = btf_type_array(t: v->t);
2893	const struct btf_type *elem_type, *index_type;
2894	u32 elem_type_id, index_type_id;
2895	struct btf *btf = env->btf;
2896	u32 elem_size;
2897
2898	/* Check array->index_type */
2899	index_type_id = array->index_type;
2900	index_type = btf_type_by_id(btf, index_type_id);
2901	if (btf_type_nosize_or_null(t: index_type) ||
2902	btf_type_is_resolve_source_only(t: index_type)) {
2903	btf_verifier_log_type(env, v->t, "Invalid index");
2904	return -EINVAL;
2905	}
2906
2907	if (!env_type_is_resolve_sink(env, next_type: index_type) &&
2908	!env_type_is_resolved(env, type_id: index_type_id))
2909	return env_stack_push(env, t: index_type, type_id: index_type_id);
2910
2911	index_type = btf_type_id_size(btf, type_id: &index_type_id, NULL);
2912	if (!index_type || !btf_type_is_int(t: index_type) ||
2913	!btf_type_int_is_regular(t: index_type)) {
2914	btf_verifier_log_type(env, v->t, "Invalid index");
2915	return -EINVAL;
2916	}
2917
2918	/* Check array->type */
2919	elem_type_id = array->type;
2920	elem_type = btf_type_by_id(btf, elem_type_id);
2921	if (btf_type_nosize_or_null(t: elem_type) ||
2922	btf_type_is_resolve_source_only(t: elem_type)) {
2923	btf_verifier_log_type(env, v->t,
2924	"Invalid elem");
2925	return -EINVAL;
2926	}
2927
2928	if (!env_type_is_resolve_sink(env, next_type: elem_type) &&
2929	!env_type_is_resolved(env, type_id: elem_type_id))
2930	return env_stack_push(env, t: elem_type, type_id: elem_type_id);
2931
2932	elem_type = btf_type_id_size(btf, type_id: &elem_type_id, ret_size: &elem_size);
2933	if (!elem_type) {
2934	btf_verifier_log_type(env, v->t, "Invalid elem");
2935	return -EINVAL;
2936	}
2937
2938	if (btf_type_is_int(t: elem_type) && !btf_type_int_is_regular(t: elem_type)) {
2939	btf_verifier_log_type(env, v->t, "Invalid array of int");
2940	return -EINVAL;
2941	}
2942
2943	if (array->nelems && elem_size > U32_MAX / array->nelems) {
2944	btf_verifier_log_type(env, v->t,
2945	"Array size overflows U32_MAX");
2946	return -EINVAL;
2947	}
2948
2949	env_stack_pop_resolved(env, resolved_type_id: elem_type_id, resolved_size: elem_size * array->nelems);
2950
2951	return 0;
2952	}
2953
2954	static void btf_array_log(struct btf_verifier_env *env,
2955	const struct btf_type *t)
2956	{
2957	const struct btf_array *array = btf_type_array(t);
2958
2959	btf_verifier_log(env, fmt: "type_id=%u index_type_id=%u nr_elems=%u",
2960	array->type, array->index_type, array->nelems);
2961	}
2962
2963	static void __btf_array_show(const struct btf *btf, const struct btf_type *t,
2964	u32 type_id, void *data, u8 bits_offset,
2965	struct btf_show *show)
2966	{
2967	const struct btf_array *array = btf_type_array(t);
2968	const struct btf_kind_operations *elem_ops;
2969	const struct btf_type *elem_type;
2970	u32 i, elem_size = 0, elem_type_id;
2971	u16 encoding = 0;
2972
2973	elem_type_id = array->type;
2974	elem_type = btf_type_skip_modifiers(btf, id: elem_type_id, NULL);
2975	if (elem_type && btf_type_has_size(t: elem_type))
2976	elem_size = elem_type->size;
2977
2978	if (elem_type && btf_type_is_int(t: elem_type)) {
2979	u32 int_type = btf_type_int(t: elem_type);
2980
2981	encoding = BTF_INT_ENCODING(int_type);
2982
2983	/*
2984	* BTF_INT_CHAR encoding never seems to be set for
2985	* char arrays, so if size is 1 and element is
2986	* printable as a char, we'll do that.
2987	*/
2988	if (elem_size == 1)
2989	encoding = BTF_INT_CHAR;
2990	}
2991
2992	if (!btf_show_start_array_type(show, t, type_id, array_encoding: encoding, data))
2993	return;
2994
2995	if (!elem_type)
2996	goto out;
2997	elem_ops = btf_type_ops(t: elem_type);
2998
2999	for (i = 0; i < array->nelems; i++) {
3000
3001	btf_show_start_array_member(show);
3002
3003	elem_ops->show(btf, elem_type, elem_type_id, data,
3004	bits_offset, show);
3005	data += elem_size;
3006
3007	btf_show_end_array_member(show);
3008
3009	if (show->state.array_terminated)
3010	break;
3011	}
3012	out:
3013	btf_show_end_array_type(show);
3014	}
3015
3016	static void btf_array_show(const struct btf *btf, const struct btf_type *t,
3017	u32 type_id, void *data, u8 bits_offset,
3018	struct btf_show *show)
3019	{
3020	const struct btf_member *m = show->state.member;
3021
3022	/*
3023	* First check if any members would be shown (are non-zero).
3024	* See comments above "struct btf_show" definition for more
3025	* details on how this works at a high-level.
3026	*/
3027	if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
3028	if (!show->state.depth_check) {
3029	show->state.depth_check = show->state.depth + 1;
3030	show->state.depth_to_show = 0;
3031	}
3032	__btf_array_show(btf, t, type_id, data, bits_offset, show);
3033	show->state.member = m;
3034
3035	if (show->state.depth_check != show->state.depth + 1)
3036	return;
3037	show->state.depth_check = 0;
3038
3039	if (show->state.depth_to_show <= show->state.depth)
3040	return;
3041	/*
3042	* Reaching here indicates we have recursed and found
3043	* non-zero array member(s).
3044	*/
3045	}
3046	__btf_array_show(btf, t, type_id, data, bits_offset, show);
3047	}
3048
3049	static struct btf_kind_operations array_ops = {
3050	.check_meta = btf_array_check_meta,
3051	.resolve = btf_array_resolve,
3052	.check_member = btf_array_check_member,
3053	.check_kflag_member = btf_generic_check_kflag_member,
3054	.log_details = btf_array_log,
3055	.show = btf_array_show,
3056	};
3057
3058	static int btf_struct_check_member(struct btf_verifier_env *env,
3059	const struct btf_type *struct_type,
3060	const struct btf_member *member,
3061	const struct btf_type *member_type)
3062	{
3063	u32 struct_bits_off = member->offset;
3064	u32 struct_size, bytes_offset;
3065
3066	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
3067	btf_verifier_log_member(env, struct_type, member,
3068	fmt: "Member is not byte aligned");
3069	return -EINVAL;
3070	}
3071
3072	struct_size = struct_type->size;
3073	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
3074	if (struct_size - bytes_offset < member_type->size) {
3075	btf_verifier_log_member(env, struct_type, member,
3076	fmt: "Member exceeds struct_size");
3077	return -EINVAL;
3078	}
3079
3080	return 0;
3081	}
3082
3083	static s32 btf_struct_check_meta(struct btf_verifier_env *env,
3084	const struct btf_type *t,
3085	u32 meta_left)
3086	{
3087	bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION;
3088	const struct btf_member *member;
3089	u32 meta_needed, last_offset;
3090	struct btf *btf = env->btf;
3091	u32 struct_size = t->size;
3092	u32 offset;
3093	u16 i;
3094
3095	meta_needed = btf_type_vlen(t) * sizeof(*member);
3096	if (meta_left < meta_needed) {
3097	btf_verifier_log_basic(env, t,
3098	"meta_left:%u meta_needed:%u",
3099	meta_left, meta_needed);
3100	return -EINVAL;
3101	}
3102
3103	/* struct type either no name or a valid one */
3104	if (t->name_off &&
3105	!btf_name_valid_identifier(btf: env->btf, offset: t->name_off)) {
3106	btf_verifier_log_type(env, t, "Invalid name");
3107	return -EINVAL;
3108	}
3109
3110	btf_verifier_log_type(env, t, NULL);
3111
3112	last_offset = 0;
3113	for_each_member(i, t, member) {
3114	if (!btf_name_offset_valid(btf, offset: member->name_off)) {
3115	btf_verifier_log_member(env, struct_type: t, member,
3116	fmt: "Invalid member name_offset:%u",
3117	member->name_off);
3118	return -EINVAL;
3119	}
3120
3121	/* struct member either no name or a valid one */
3122	if (member->name_off &&
3123	!btf_name_valid_identifier(btf, offset: member->name_off)) {
3124	btf_verifier_log_member(env, struct_type: t, member, fmt: "Invalid name");
3125	return -EINVAL;
3126	}
3127	/* A member cannot be in type void */
3128	if (!member->type || !BTF_TYPE_ID_VALID(member->type)) {
3129	btf_verifier_log_member(env, struct_type: t, member,
3130	fmt: "Invalid type_id");
3131	return -EINVAL;
3132	}
3133
3134	offset = __btf_member_bit_offset(struct_type: t, member);
3135	if (is_union && offset) {
3136	btf_verifier_log_member(env, struct_type: t, member,
3137	fmt: "Invalid member bits_offset");
3138	return -EINVAL;
3139	}
3140
3141	/*
3142	* ">" instead of ">=" because the last member could be
3143	* "char a[0];"
3144	*/
3145	if (last_offset > offset) {
3146	btf_verifier_log_member(env, struct_type: t, member,
3147	fmt: "Invalid member bits_offset");
3148	return -EINVAL;
3149	}
3150
3151	if (BITS_ROUNDUP_BYTES(offset) > struct_size) {
3152	btf_verifier_log_member(env, struct_type: t, member,
3153	fmt: "Member bits_offset exceeds its struct size");
3154	return -EINVAL;
3155	}
3156
3157	btf_verifier_log_member(env, struct_type: t, member, NULL);
3158	last_offset = offset;
3159	}
3160
3161	return meta_needed;
3162	}
3163
3164	static int btf_struct_resolve(struct btf_verifier_env *env,
3165	const struct resolve_vertex *v)
3166	{
3167	const struct btf_member *member;
3168	int err;
3169	u16 i;
3170
3171	/* Before continue resolving the next_member,
3172	* ensure the last member is indeed resolved to a
3173	* type with size info.
3174	*/
3175	if (v->next_member) {
3176	const struct btf_type *last_member_type;
3177	const struct btf_member *last_member;
3178	u32 last_member_type_id;
3179
3180	last_member = btf_type_member(t: v->t) + v->next_member - 1;
3181	last_member_type_id = last_member->type;
3182	if (WARN_ON_ONCE(!env_type_is_resolved(env,
3183	last_member_type_id)))
3184	return -EINVAL;
3185
3186	last_member_type = btf_type_by_id(env->btf,
3187	last_member_type_id);
3188	if (btf_type_kflag(t: v->t))
3189	err = btf_type_ops(t: last_member_type)->check_kflag_member(env, v->t,
3190	last_member,
3191	last_member_type);
3192	else
3193	err = btf_type_ops(t: last_member_type)->check_member(env, v->t,
3194	last_member,
3195	last_member_type);
3196	if (err)
3197	return err;
3198	}
3199
3200	for_each_member_from(i, v->next_member, v->t, member) {
3201	u32 member_type_id = member->type;
3202	const struct btf_type *member_type = btf_type_by_id(env->btf,
3203	member_type_id);
3204
3205	if (btf_type_nosize_or_null(t: member_type) ||
3206	btf_type_is_resolve_source_only(t: member_type)) {
3207	btf_verifier_log_member(env, struct_type: v->t, member,
3208	fmt: "Invalid member");
3209	return -EINVAL;
3210	}
3211
3212	if (!env_type_is_resolve_sink(env, next_type: member_type) &&
3213	!env_type_is_resolved(env, type_id: member_type_id)) {
3214	env_stack_set_next_member(env, next_member: i + 1);
3215	return env_stack_push(env, t: member_type, type_id: member_type_id);
3216	}
3217
3218	if (btf_type_kflag(t: v->t))
3219	err = btf_type_ops(t: member_type)->check_kflag_member(env, v->t,
3220	member,
3221	member_type);
3222	else
3223	err = btf_type_ops(t: member_type)->check_member(env, v->t,
3224	member,
3225	member_type);
3226	if (err)
3227	return err;
3228	}
3229
3230	env_stack_pop_resolved(env, resolved_type_id: 0, resolved_size: 0);
3231
3232	return 0;
3233	}
3234
3235	static void btf_struct_log(struct btf_verifier_env *env,
3236	const struct btf_type *t)
3237	{
3238	btf_verifier_log(env, fmt: "size=%u vlen=%u", t->size, btf_type_vlen(t));
3239	}
3240
3241	enum {
3242	BTF_FIELD_IGNORE = 0,
3243	BTF_FIELD_FOUND = 1,
3244	};
3245
3246	struct btf_field_info {
3247	enum btf_field_type type;
3248	u32 off;
3249	union {
3250	struct {
3251	u32 type_id;
3252	} kptr;
3253	struct {
3254	const char *node_name;
3255	u32 value_btf_id;
3256	} graph_root;
3257	};
3258	};
3259
3260	static int btf_find_struct(const struct btf *btf, const struct btf_type *t,
3261	u32 off, int sz, enum btf_field_type field_type,
3262	struct btf_field_info *info)
3263	{
3264	if (!__btf_type_is_struct(t))
3265	return BTF_FIELD_IGNORE;
3266	if (t->size != sz)
3267	return BTF_FIELD_IGNORE;
3268	info->type = field_type;
3269	info->off = off;
3270	return BTF_FIELD_FOUND;
3271	}
3272
3273	static int btf_find_kptr(const struct btf *btf, const struct btf_type *t,
3274	u32 off, int sz, struct btf_field_info *info)
3275	{
3276	enum btf_field_type type;
3277	u32 res_id;
3278
3279	/* Permit modifiers on the pointer itself */
3280	if (btf_type_is_volatile(t))
3281	t = btf_type_by_id(btf, t->type);
3282	/* For PTR, sz is always == 8 */
3283	if (!btf_type_is_ptr(t))
3284	return BTF_FIELD_IGNORE;
3285	t = btf_type_by_id(btf, t->type);
3286
3287	if (!btf_type_is_type_tag(t))
3288	return BTF_FIELD_IGNORE;
3289	/* Reject extra tags */
3290	if (btf_type_is_type_tag(t: btf_type_by_id(btf, t->type)))
3291	return -EINVAL;
3292	if (!strcmp("kptr_untrusted", __btf_name_by_offset(btf, offset: t->name_off)))
3293	type = BPF_KPTR_UNREF;
3294	else if (!strcmp("kptr", __btf_name_by_offset(btf, offset: t->name_off)))
3295	type = BPF_KPTR_REF;
3296	else if (!strcmp("percpu_kptr", __btf_name_by_offset(btf, offset: t->name_off)))
3297	type = BPF_KPTR_PERCPU;
3298	else
3299	return -EINVAL;
3300
3301	/* Get the base type */
3302	t = btf_type_skip_modifiers(btf, id: t->type, res_id: &res_id);
3303	/* Only pointer to struct is allowed */
3304	if (!__btf_type_is_struct(t))
3305	return -EINVAL;
3306
3307	info->type = type;
3308	info->off = off;
3309	info->kptr.type_id = res_id;
3310	return BTF_FIELD_FOUND;
3311	}
3312
3313	const char *btf_find_decl_tag_value(const struct btf *btf, const struct btf_type *pt,
3314	int comp_idx, const char *tag_key)
3315	{
3316	const char *value = NULL;
3317	int i;
3318
3319	for (i = 1; i < btf_nr_types(btf); i++) {
3320	const struct btf_type *t = btf_type_by_id(btf, i);
3321	int len = strlen(tag_key);
3322
3323	if (!btf_type_is_decl_tag(t))
3324	continue;
3325	if (pt != btf_type_by_id(btf, t->type) ||
3326	btf_type_decl_tag(t)->component_idx != comp_idx)
3327	continue;
3328	if (strncmp(__btf_name_by_offset(btf, offset: t->name_off), tag_key, len))
3329	continue;
3330	/* Prevent duplicate entries for same type */
3331	if (value)
3332	return ERR_PTR(error: -EEXIST);
3333	value = __btf_name_by_offset(btf, offset: t->name_off) + len;
3334	}
3335	if (!value)
3336	return ERR_PTR(error: -ENOENT);
3337	return value;
3338	}
3339
3340	static int
3341	btf_find_graph_root(const struct btf *btf, const struct btf_type *pt,
3342	const struct btf_type *t, int comp_idx, u32 off,
3343	int sz, struct btf_field_info *info,
3344	enum btf_field_type head_type)
3345	{
3346	const char *node_field_name;
3347	const char *value_type;
3348	s32 id;
3349
3350	if (!__btf_type_is_struct(t))
3351	return BTF_FIELD_IGNORE;
3352	if (t->size != sz)
3353	return BTF_FIELD_IGNORE;
3354	value_type = btf_find_decl_tag_value(btf, pt, comp_idx, tag_key: "contains:");
3355	if (IS_ERR(ptr: value_type))
3356	return -EINVAL;
3357	node_field_name = strstr(value_type, ":");
3358	if (!node_field_name)
3359	return -EINVAL;
3360	value_type = kstrndup(s: value_type, len: node_field_name - value_type, GFP_KERNEL | __GFP_NOWARN);
3361	if (!value_type)
3362	return -ENOMEM;
3363	id = btf_find_by_name_kind(btf, name: value_type, kind: BTF_KIND_STRUCT);
3364	kfree(objp: value_type);
3365	if (id < 0)
3366	return id;
3367	node_field_name++;
3368	if (str_is_empty(s: node_field_name))
3369	return -EINVAL;
3370	info->type = head_type;
3371	info->off = off;
3372	info->graph_root.value_btf_id = id;
3373	info->graph_root.node_name = node_field_name;
3374	return BTF_FIELD_FOUND;
3375	}
3376
3377	#define field_mask_test_name(field_type, field_type_str) \
3378	if (field_mask & field_type && !strcmp(name, field_type_str)) { \
3379	type = field_type; \
3380	goto end; \
3381	}
3382
3383	static int btf_get_field_type(const char *name, u32 field_mask, u32 *seen_mask,
3384	int *align, int *sz)
3385	{
3386	int type = 0;
3387
3388	if (field_mask & BPF_SPIN_LOCK) {
3389	if (!strcmp(name, "bpf_spin_lock")) {
3390	if (*seen_mask & BPF_SPIN_LOCK)
3391	return -E2BIG;
3392	*seen_mask |= BPF_SPIN_LOCK;
3393	type = BPF_SPIN_LOCK;
3394	goto end;
3395	}
3396	}
3397	if (field_mask & BPF_TIMER) {
3398	if (!strcmp(name, "bpf_timer")) {
3399	if (*seen_mask & BPF_TIMER)
3400	return -E2BIG;
3401	*seen_mask |= BPF_TIMER;
3402	type = BPF_TIMER;
3403	goto end;
3404	}
3405	}
3406	field_mask_test_name(BPF_LIST_HEAD, "bpf_list_head");
3407	field_mask_test_name(BPF_LIST_NODE, "bpf_list_node");
3408	field_mask_test_name(BPF_RB_ROOT, "bpf_rb_root");
3409	field_mask_test_name(BPF_RB_NODE, "bpf_rb_node");
3410	field_mask_test_name(BPF_REFCOUNT, "bpf_refcount");
3411
3412	/* Only return BPF_KPTR when all other types with matchable names fail */
3413	if (field_mask & BPF_KPTR) {
3414	type = BPF_KPTR_REF;
3415	goto end;
3416	}
3417	return 0;
3418	end:
3419	*sz = btf_field_type_size(type);
3420	*align = btf_field_type_align(type);
3421	return type;
3422	}
3423
3424	#undef field_mask_test_name
3425
3426	static int btf_find_struct_field(const struct btf *btf,
3427	const struct btf_type *t, u32 field_mask,
3428	struct btf_field_info *info, int info_cnt)
3429	{
3430	int ret, idx = 0, align, sz, field_type;
3431	const struct btf_member *member;
3432	struct btf_field_info tmp;
3433	u32 i, off, seen_mask = 0;
3434
3435	for_each_member(i, t, member) {
3436	const struct btf_type *member_type = btf_type_by_id(btf,
3437	member->type);
3438
3439	field_type = btf_get_field_type(name: __btf_name_by_offset(btf, offset: member_type->name_off),
3440	field_mask, seen_mask: &seen_mask, align: &align, sz: &sz);
3441	if (field_type == 0)
3442	continue;
3443	if (field_type < 0)
3444	return field_type;
3445
3446	off = __btf_member_bit_offset(struct_type: t, member);
3447	if (off % 8)
3448	/* valid C code cannot generate such BTF */
3449	return -EINVAL;
3450	off /= 8;
3451	if (off % align)
3452	continue;
3453
3454	switch (field_type) {
3455	case BPF_SPIN_LOCK:
3456	case BPF_TIMER:
3457	case BPF_LIST_NODE:
3458	case BPF_RB_NODE:
3459	case BPF_REFCOUNT:
3460	ret = btf_find_struct(btf, t: member_type, off, sz, field_type,
3461	info: idx < info_cnt ? &info[idx] : &tmp);
3462	if (ret < 0)
3463	return ret;
3464	break;
3465	case BPF_KPTR_UNREF:
3466	case BPF_KPTR_REF:
3467	case BPF_KPTR_PERCPU:
3468	ret = btf_find_kptr(btf, t: member_type, off, sz,
3469	info: idx < info_cnt ? &info[idx] : &tmp);
3470	if (ret < 0)
3471	return ret;
3472	break;
3473	case BPF_LIST_HEAD:
3474	case BPF_RB_ROOT:
3475	ret = btf_find_graph_root(btf, pt: t, t: member_type,
3476	comp_idx: i, off, sz,
3477	info: idx < info_cnt ? &info[idx] : &tmp,
3478	head_type: field_type);
3479	if (ret < 0)
3480	return ret;
3481	break;
3482	default:
3483	return -EFAULT;
3484	}
3485
3486	if (ret == BTF_FIELD_IGNORE)
3487	continue;
3488	if (idx >= info_cnt)
3489	return -E2BIG;
3490	++idx;
3491	}
3492	return idx;
3493	}
3494
3495	static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t,
3496	u32 field_mask, struct btf_field_info *info,
3497	int info_cnt)
3498	{
3499	int ret, idx = 0, align, sz, field_type;
3500	const struct btf_var_secinfo *vsi;
3501	struct btf_field_info tmp;
3502	u32 i, off, seen_mask = 0;
3503
3504	for_each_vsi(i, t, vsi) {
3505	const struct btf_type *var = btf_type_by_id(btf, vsi->type);
3506	const struct btf_type *var_type = btf_type_by_id(btf, var->type);
3507
3508	field_type = btf_get_field_type(name: __btf_name_by_offset(btf, offset: var_type->name_off),
3509	field_mask, seen_mask: &seen_mask, align: &align, sz: &sz);
3510	if (field_type == 0)
3511	continue;
3512	if (field_type < 0)
3513	return field_type;
3514
3515	off = vsi->offset;
3516	if (vsi->size != sz)
3517	continue;
3518	if (off % align)
3519	continue;
3520
3521	switch (field_type) {
3522	case BPF_SPIN_LOCK:
3523	case BPF_TIMER:
3524	case BPF_LIST_NODE:
3525	case BPF_RB_NODE:
3526	case BPF_REFCOUNT:
3527	ret = btf_find_struct(btf, t: var_type, off, sz, field_type,
3528	info: idx < info_cnt ? &info[idx] : &tmp);
3529	if (ret < 0)
3530	return ret;
3531	break;
3532	case BPF_KPTR_UNREF:
3533	case BPF_KPTR_REF:
3534	case BPF_KPTR_PERCPU:
3535	ret = btf_find_kptr(btf, t: var_type, off, sz,
3536	info: idx < info_cnt ? &info[idx] : &tmp);
3537	if (ret < 0)
3538	return ret;
3539	break;
3540	case BPF_LIST_HEAD:
3541	case BPF_RB_ROOT:
3542	ret = btf_find_graph_root(btf, pt: var, t: var_type,
3543	comp_idx: -1, off, sz,
3544	info: idx < info_cnt ? &info[idx] : &tmp,
3545	head_type: field_type);
3546	if (ret < 0)
3547	return ret;
3548	break;
3549	default:
3550	return -EFAULT;
3551	}
3552
3553	if (ret == BTF_FIELD_IGNORE)
3554	continue;
3555	if (idx >= info_cnt)
3556	return -E2BIG;
3557	++idx;
3558	}
3559	return idx;
3560	}
3561
3562	static int btf_find_field(const struct btf *btf, const struct btf_type *t,
3563	u32 field_mask, struct btf_field_info *info,
3564	int info_cnt)
3565	{
3566	if (__btf_type_is_struct(t))
3567	return btf_find_struct_field(btf, t, field_mask, info, info_cnt);
3568	else if (btf_type_is_datasec(t))
3569	return btf_find_datasec_var(btf, t, field_mask, info, info_cnt);
3570	return -EINVAL;
3571	}
3572
3573	static int btf_parse_kptr(const struct btf *btf, struct btf_field *field,
3574	struct btf_field_info *info)
3575	{
3576	struct module *mod = NULL;
3577	const struct btf_type *t;
3578	/* If a matching btf type is found in kernel or module BTFs, kptr_ref
3579	* is that BTF, otherwise it's program BTF
3580	*/
3581	struct btf *kptr_btf;
3582	int ret;
3583	s32 id;
3584
3585	/* Find type in map BTF, and use it to look up the matching type
3586	* in vmlinux or module BTFs, by name and kind.
3587	*/
3588	t = btf_type_by_id(btf, info->kptr.type_id);
3589	id = bpf_find_btf_id(name: __btf_name_by_offset(btf, offset: t->name_off), BTF_INFO_KIND(t->info),
3590	btf_p: &kptr_btf);
3591	if (id == -ENOENT) {
3592	/* btf_parse_kptr should only be called w/ btf = program BTF */
3593	WARN_ON_ONCE(btf_is_kernel(btf));
3594
3595	/* Type exists only in program BTF. Assume that it's a MEM_ALLOC
3596	* kptr allocated via bpf_obj_new
3597	*/
3598	field->kptr.dtor = NULL;
3599	id = info->kptr.type_id;
3600	kptr_btf = (struct btf *)btf;
3601	btf_get(btf: kptr_btf);
3602	goto found_dtor;
3603	}
3604	if (id < 0)
3605	return id;
3606
3607	/* Find and stash the function pointer for the destruction function that
3608	* needs to be eventually invoked from the map free path.
3609	*/
3610	if (info->type == BPF_KPTR_REF) {
3611	const struct btf_type *dtor_func;
3612	const char *dtor_func_name;
3613	unsigned long addr;
3614	s32 dtor_btf_id;
3615
3616	/* This call also serves as a whitelist of allowed objects that
3617	* can be used as a referenced pointer and be stored in a map at
3618	* the same time.
3619	*/
3620	dtor_btf_id = btf_find_dtor_kfunc(btf: kptr_btf, btf_id: id);
3621	if (dtor_btf_id < 0) {
3622	ret = dtor_btf_id;
3623	goto end_btf;
3624	}
3625
3626	dtor_func = btf_type_by_id(kptr_btf, dtor_btf_id);
3627	if (!dtor_func) {
3628	ret = -ENOENT;
3629	goto end_btf;
3630	}
3631
3632	if (btf_is_module(btf: kptr_btf)) {
3633	mod = btf_try_get_module(btf: kptr_btf);
3634	if (!mod) {
3635	ret = -ENXIO;
3636	goto end_btf;
3637	}
3638	}
3639
3640	/* We already verified dtor_func to be btf_type_is_func
3641	* in register_btf_id_dtor_kfuncs.
3642	*/
3643	dtor_func_name = __btf_name_by_offset(btf: kptr_btf, offset: dtor_func->name_off);
3644	addr = kallsyms_lookup_name(name: dtor_func_name);
3645	if (!addr) {
3646	ret = -EINVAL;
3647	goto end_mod;
3648	}
3649	field->kptr.dtor = (void *)addr;
3650	}
3651
3652	found_dtor:
3653	field->kptr.btf_id = id;
3654	field->kptr.btf = kptr_btf;
3655	field->kptr.module = mod;
3656	return 0;
3657	end_mod:
3658	module_put(module: mod);
3659	end_btf:
3660	btf_put(btf: kptr_btf);
3661	return ret;
3662	}
3663
3664	static int btf_parse_graph_root(const struct btf *btf,
3665	struct btf_field *field,
3666	struct btf_field_info *info,
3667	const char *node_type_name,
3668	size_t node_type_align)
3669	{
3670	const struct btf_type *t, *n = NULL;
3671	const struct btf_member *member;
3672	u32 offset;
3673	int i;
3674
3675	t = btf_type_by_id(btf, info->graph_root.value_btf_id);
3676	/* We've already checked that value_btf_id is a struct type. We
3677	* just need to figure out the offset of the list_node, and
3678	* verify its type.
3679	*/
3680	for_each_member(i, t, member) {
3681	if (strcmp(info->graph_root.node_name,
3682	__btf_name_by_offset(btf, offset: member->name_off)))
3683	continue;
3684	/* Invalid BTF, two members with same name */
3685	if (n)
3686	return -EINVAL;
3687	n = btf_type_by_id(btf, member->type);
3688	if (!__btf_type_is_struct(t: n))
3689	return -EINVAL;
3690	if (strcmp(node_type_name, __btf_name_by_offset(btf, offset: n->name_off)))
3691	return -EINVAL;
3692	offset = __btf_member_bit_offset(struct_type: n, member);
3693	if (offset % 8)
3694	return -EINVAL;
3695	offset /= 8;
3696	if (offset % node_type_align)
3697	return -EINVAL;
3698
3699	field->graph_root.btf = (struct btf *)btf;
3700	field->graph_root.value_btf_id = info->graph_root.value_btf_id;
3701	field->graph_root.node_offset = offset;
3702	}
3703	if (!n)
3704	return -ENOENT;
3705	return 0;
3706	}
3707
3708	static int btf_parse_list_head(const struct btf *btf, struct btf_field *field,
3709	struct btf_field_info *info)
3710	{
3711	return btf_parse_graph_root(btf, field, info, node_type_name: "bpf_list_node",
3712	node_type_align: __alignof__(struct bpf_list_node));
3713	}
3714
3715	static int btf_parse_rb_root(const struct btf *btf, struct btf_field *field,
3716	struct btf_field_info *info)
3717	{
3718	return btf_parse_graph_root(btf, field, info, node_type_name: "bpf_rb_node",
3719	node_type_align: __alignof__(struct bpf_rb_node));
3720	}
3721
3722	static int btf_field_cmp(const void *_a, const void *_b, const void *priv)
3723	{
3724	const struct btf_field *a = (const struct btf_field *)_a;
3725	const struct btf_field *b = (const struct btf_field *)_b;
3726
3727	if (a->offset < b->offset)
3728	return -1;
3729	else if (a->offset > b->offset)
3730	return 1;
3731	return 0;
3732	}
3733
3734	struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
3735	u32 field_mask, u32 value_size)
3736	{
3737	struct btf_field_info info_arr[BTF_FIELDS_MAX];
3738	u32 next_off = 0, field_type_size;
3739	struct btf_record *rec;
3740	int ret, i, cnt;
3741
3742	ret = btf_find_field(btf, t, field_mask, info: info_arr, ARRAY_SIZE(info_arr));
3743	if (ret < 0)
3744	return ERR_PTR(error: ret);
3745	if (!ret)
3746	return NULL;
3747
3748	cnt = ret;
3749	/* This needs to be kzalloc to zero out padding and unused fields, see
3750	* comment in btf_record_equal.
3751	*/
3752	rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN);
3753	if (!rec)
3754	return ERR_PTR(error: -ENOMEM);
3755
3756	rec->spin_lock_off = -EINVAL;
3757	rec->timer_off = -EINVAL;
3758	rec->refcount_off = -EINVAL;
3759	for (i = 0; i < cnt; i++) {
3760	field_type_size = btf_field_type_size(type: info_arr[i].type);
3761	if (info_arr[i].off + field_type_size > value_size) {
3762	WARN_ONCE(1, "verifier bug off %d size %d", info_arr[i].off, value_size);
3763	ret = -EFAULT;
3764	goto end;
3765	}
3766	if (info_arr[i].off < next_off) {
3767	ret = -EEXIST;
3768	goto end;
3769	}
3770	next_off = info_arr[i].off + field_type_size;
3771
3772	rec->field_mask |= info_arr[i].type;
3773	rec->fields[i].offset = info_arr[i].off;
3774	rec->fields[i].type = info_arr[i].type;
3775	rec->fields[i].size = field_type_size;
3776
3777	switch (info_arr[i].type) {
3778	case BPF_SPIN_LOCK:
3779	WARN_ON_ONCE(rec->spin_lock_off >= 0);
3780	/* Cache offset for faster lookup at runtime */
3781	rec->spin_lock_off = rec->fields[i].offset;
3782	break;
3783	case BPF_TIMER:
3784	WARN_ON_ONCE(rec->timer_off >= 0);
3785	/* Cache offset for faster lookup at runtime */
3786	rec->timer_off = rec->fields[i].offset;
3787	break;
3788	case BPF_REFCOUNT:
3789	WARN_ON_ONCE(rec->refcount_off >= 0);
3790	/* Cache offset for faster lookup at runtime */
3791	rec->refcount_off = rec->fields[i].offset;
3792	break;
3793	case BPF_KPTR_UNREF:
3794	case BPF_KPTR_REF:
3795	case BPF_KPTR_PERCPU:
3796	ret = btf_parse_kptr(btf, field: &rec->fields[i], info: &info_arr[i]);
3797	if (ret < 0)
3798	goto end;
3799	break;
3800	case BPF_LIST_HEAD:
3801	ret = btf_parse_list_head(btf, field: &rec->fields[i], info: &info_arr[i]);
3802	if (ret < 0)
3803	goto end;
3804	break;
3805	case BPF_RB_ROOT:
3806	ret = btf_parse_rb_root(btf, field: &rec->fields[i], info: &info_arr[i]);
3807	if (ret < 0)
3808	goto end;
3809	break;
3810	case BPF_LIST_NODE:
3811	case BPF_RB_NODE:
3812	break;
3813	default:
3814	ret = -EFAULT;
3815	goto end;
3816	}
3817	rec->cnt++;
3818	}
3819
3820	/* bpf_{list_head, rb_node} require bpf_spin_lock */
3821	if ((btf_record_has_field(rec, type: BPF_LIST_HEAD) ||
3822	btf_record_has_field(rec, type: BPF_RB_ROOT)) && rec->spin_lock_off < 0) {
3823	ret = -EINVAL;
3824	goto end;
3825	}
3826
3827	if (rec->refcount_off < 0 &&
3828	btf_record_has_field(rec, type: BPF_LIST_NODE) &&
3829	btf_record_has_field(rec, type: BPF_RB_NODE)) {
3830	ret = -EINVAL;
3831	goto end;
3832	}
3833
3834	sort_r(base: rec->fields, num: rec->cnt, size: sizeof(struct btf_field), cmp_func: btf_field_cmp,
3835	NULL, priv: rec);
3836
3837	return rec;
3838	end:
3839	btf_record_free(rec);
3840	return ERR_PTR(error: ret);
3841	}
3842
3843	#define GRAPH_ROOT_MASK (BPF_LIST_HEAD | BPF_RB_ROOT)
3844	#define GRAPH_NODE_MASK (BPF_LIST_NODE | BPF_RB_NODE)
3845
3846	int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
3847	{
3848	int i;
3849
3850	/* There are three types that signify ownership of some other type:
3851	* kptr_ref, bpf_list_head, bpf_rb_root.
3852	* kptr_ref only supports storing kernel types, which can't store
3853	* references to program allocated local types.
3854	*
3855	* Hence we only need to ensure that bpf_{list_head,rb_root} ownership
3856	* does not form cycles.
3857	*/
3858	if (IS_ERR_OR_NULL(ptr: rec) || !(rec->field_mask & GRAPH_ROOT_MASK))
3859	return 0;
3860	for (i = 0; i < rec->cnt; i++) {
3861	struct btf_struct_meta *meta;
3862	u32 btf_id;
3863
3864	if (!(rec->fields[i].type & GRAPH_ROOT_MASK))
3865	continue;
3866	btf_id = rec->fields[i].graph_root.value_btf_id;
3867	meta = btf_find_struct_meta(btf, btf_id);
3868	if (!meta)
3869	return -EFAULT;
3870	rec->fields[i].graph_root.value_rec = meta->record;
3871
3872	/* We need to set value_rec for all root types, but no need
3873	* to check ownership cycle for a type unless it's also a
3874	* node type.
3875	*/
3876	if (!(rec->field_mask & GRAPH_NODE_MASK))
3877	continue;
3878
3879	/* We need to ensure ownership acyclicity among all types. The
3880	* proper way to do it would be to topologically sort all BTF
3881	* IDs based on the ownership edges, since there can be multiple
3882	* bpf_{list_head,rb_node} in a type. Instead, we use the
3883	* following resaoning:
3884	*
3885	* - A type can only be owned by another type in user BTF if it
3886	* has a bpf_{list,rb}_node. Let's call these node types.
3887	* - A type can only _own_ another type in user BTF if it has a
3888	* bpf_{list_head,rb_root}. Let's call these root types.
3889	*
3890	* We ensure that if a type is both a root and node, its
3891	* element types cannot be root types.
3892	*
3893	* To ensure acyclicity:
3894	*
3895	* When A is an root type but not a node, its ownership
3896	* chain can be:
3897	* A -> B -> C
3898	* Where:
3899	* - A is an root, e.g. has bpf_rb_root.
3900	* - B is both a root and node, e.g. has bpf_rb_node and
3901	* bpf_list_head.
3902	* - C is only an root, e.g. has bpf_list_node
3903	*
3904	* When A is both a root and node, some other type already
3905	* owns it in the BTF domain, hence it can not own
3906	* another root type through any of the ownership edges.
3907	* A -> B
3908	* Where:
3909	* - A is both an root and node.
3910	* - B is only an node.
3911	*/
3912	if (meta->record->field_mask & GRAPH_ROOT_MASK)
3913	return -ELOOP;
3914	}
3915	return 0;
3916	}
3917
3918	static void __btf_struct_show(const struct btf *btf, const struct btf_type *t,
3919	u32 type_id, void *data, u8 bits_offset,
3920	struct btf_show *show)
3921	{
3922	const struct btf_member *member;
3923	void *safe_data;
3924	u32 i;
3925
3926	safe_data = btf_show_start_struct_type(show, t, type_id, data);
3927	if (!safe_data)
3928	return;
3929
3930	for_each_member(i, t, member) {
3931	const struct btf_type *member_type = btf_type_by_id(btf,
3932	member->type);
3933	const struct btf_kind_operations *ops;
3934	u32 member_offset, bitfield_size;
3935	u32 bytes_offset;
3936	u8 bits8_offset;
3937
3938	btf_show_start_member(show, m: member);
3939
3940	member_offset = __btf_member_bit_offset(struct_type: t, member);
3941	bitfield_size = __btf_member_bitfield_size(struct_type: t, member);
3942	bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset);
3943	bits8_offset = BITS_PER_BYTE_MASKED(member_offset);
3944	if (bitfield_size) {
3945	safe_data = btf_show_start_type(show, t: member_type,
3946	type_id: member->type,
3947	data: data + bytes_offset);
3948	if (safe_data)
3949	btf_bitfield_show(data: safe_data,
3950	bits_offset: bits8_offset,
3951	nr_bits: bitfield_size, show);
3952	btf_show_end_type(show);
3953	} else {
3954	ops = btf_type_ops(t: member_type);
3955	ops->show(btf, member_type, member->type,
3956	data + bytes_offset, bits8_offset, show);
3957	}
3958
3959	btf_show_end_member(show);
3960	}
3961
3962	btf_show_end_struct_type(show);
3963	}
3964
3965	static void btf_struct_show(const struct btf *btf, const struct btf_type *t,
3966	u32 type_id, void *data, u8 bits_offset,
3967	struct btf_show *show)
3968	{
3969	const struct btf_member *m = show->state.member;
3970
3971	/*
3972	* First check if any members would be shown (are non-zero).
3973	* See comments above "struct btf_show" definition for more
3974	* details on how this works at a high-level.
3975	*/
3976	if (show->state.depth > 0 && !(show->flags & BTF_SHOW_ZERO)) {
3977	if (!show->state.depth_check) {
3978	show->state.depth_check = show->state.depth + 1;
3979	show->state.depth_to_show = 0;
3980	}
3981	__btf_struct_show(btf, t, type_id, data, bits_offset, show);
3982	/* Restore saved member data here */
3983	show->state.member = m;
3984	if (show->state.depth_check != show->state.depth + 1)
3985	return;
3986	show->state.depth_check = 0;
3987
3988	if (show->state.depth_to_show <= show->state.depth)
3989	return;
3990	/*
3991	* Reaching here indicates we have recursed and found
3992	* non-zero child values.
3993	*/
3994	}
3995
3996	__btf_struct_show(btf, t, type_id, data, bits_offset, show);
3997	}
3998
3999	static struct btf_kind_operations struct_ops = {
4000	.check_meta = btf_struct_check_meta,
4001	.resolve = btf_struct_resolve,
4002	.check_member = btf_struct_check_member,
4003	.check_kflag_member = btf_generic_check_kflag_member,
4004	.log_details = btf_struct_log,
4005	.show = btf_struct_show,
4006	};
4007
4008	static int btf_enum_check_member(struct btf_verifier_env *env,
4009	const struct btf_type *struct_type,
4010	const struct btf_member *member,
4011	const struct btf_type *member_type)
4012	{
4013	u32 struct_bits_off = member->offset;
4014	u32 struct_size, bytes_offset;
4015
4016	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
4017	btf_verifier_log_member(env, struct_type, member,
4018	fmt: "Member is not byte aligned");
4019	return -EINVAL;
4020	}
4021
4022	struct_size = struct_type->size;
4023	bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off);
4024	if (struct_size - bytes_offset < member_type->size) {
4025	btf_verifier_log_member(env, struct_type, member,
4026	fmt: "Member exceeds struct_size");
4027	return -EINVAL;
4028	}
4029
4030	return 0;
4031	}
4032
4033	static int btf_enum_check_kflag_member(struct btf_verifier_env *env,
4034	const struct btf_type *struct_type,
4035	const struct btf_member *member,
4036	const struct btf_type *member_type)
4037	{
4038	u32 struct_bits_off, nr_bits, bytes_end, struct_size;
4039	u32 int_bitsize = sizeof(int) * BITS_PER_BYTE;
4040
4041	struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset);
4042	nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset);
4043	if (!nr_bits) {
4044	if (BITS_PER_BYTE_MASKED(struct_bits_off)) {
4045	btf_verifier_log_member(env, struct_type, member,
4046	fmt: "Member is not byte aligned");
4047	return -EINVAL;
4048	}
4049
4050	nr_bits = int_bitsize;
4051	} else if (nr_bits > int_bitsize) {
4052	btf_verifier_log_member(env, struct_type, member,
4053	fmt: "Invalid member bitfield_size");
4054	return -EINVAL;
4055	}
4056
4057	struct_size = struct_type->size;
4058	bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits);
4059	if (struct_size < bytes_end) {
4060	btf_verifier_log_member(env, struct_type, member,
4061	fmt: "Member exceeds struct_size");
4062	return -EINVAL;
4063	}
4064
4065	return 0;
4066	}
4067
4068	static s32 btf_enum_check_meta(struct btf_verifier_env *env,
4069	const struct btf_type *t,
4070	u32 meta_left)
4071	{
4072	const struct btf_enum *enums = btf_type_enum(t);
4073	struct btf *btf = env->btf;
4074	const char *fmt_str;
4075	u16 i, nr_enums;
4076	u32 meta_needed;
4077
4078	nr_enums = btf_type_vlen(t);
4079	meta_needed = nr_enums * sizeof(*enums);
4080
4081	if (meta_left < meta_needed) {
4082	btf_verifier_log_basic(env, t,
4083	"meta_left:%u meta_needed:%u",
4084	meta_left, meta_needed);
4085	return -EINVAL;
4086	}
4087
4088	if (t->size > 8 || !is_power_of_2(n: t->size)) {
4089	btf_verifier_log_type(env, t, "Unexpected size");
4090	return -EINVAL;
4091	}
4092
4093	/* enum type either no name or a valid one */
4094	if (t->name_off &&
4095	!btf_name_valid_identifier(btf: env->btf, offset: t->name_off)) {
4096	btf_verifier_log_type(env, t, "Invalid name");
4097	return -EINVAL;
4098	}
4099
4100	btf_verifier_log_type(env, t, NULL);
4101
4102	for (i = 0; i < nr_enums; i++) {
4103	if (!btf_name_offset_valid(btf, offset: enums[i].name_off)) {
4104	btf_verifier_log(env, fmt: "\tInvalid name_offset:%u",
4105	enums[i].name_off);
4106	return -EINVAL;
4107	}
4108
4109	/* enum member must have a valid name */
4110	if (!enums[i].name_off ||
4111	!btf_name_valid_identifier(btf, offset: enums[i].name_off)) {
4112	btf_verifier_log_type(env, t, "Invalid name");
4113	return -EINVAL;
4114	}
4115
4116	if (env->log.level == BPF_LOG_KERNEL)
4117	continue;
4118	fmt_str = btf_type_kflag(t) ? "\t%s val=%d\n" : "\t%s val=%u\n";
4119	btf_verifier_log(env, fmt: fmt_str,
4120	__btf_name_by_offset(btf, offset: enums[i].name_off),
4121	enums[i].val);
4122	}
4123
4124	return meta_needed;
4125	}
4126
4127	static void btf_enum_log(struct btf_verifier_env *env,
4128	const struct btf_type *t)
4129	{
4130	btf_verifier_log(env, fmt: "size=%u vlen=%u", t->size, btf_type_vlen(t));
4131	}
4132
4133	static void btf_enum_show(const struct btf *btf, const struct btf_type *t,
4134	u32 type_id, void *data, u8 bits_offset,
4135	struct btf_show *show)
4136	{
4137	const struct btf_enum *enums = btf_type_enum(t);
4138	u32 i, nr_enums = btf_type_vlen(t);
4139	void *safe_data;
4140	int v;
4141
4142	safe_data = btf_show_start_type(show, t, type_id, data);
4143	if (!safe_data)
4144	return;
4145
4146	v = *(int *)safe_data;
4147
4148	for (i = 0; i < nr_enums; i++) {
4149	if (v != enums[i].val)
4150	continue;
4151
4152	btf_show_type_value(show, "%s",
4153	__btf_name_by_offset(btf,
4154	enums[i].name_off));
4155
4156	btf_show_end_type(show);
4157	return;
4158	}
4159
4160	if (btf_type_kflag(t))
4161	btf_show_type_value(show, "%d", v);
4162	else
4163	btf_show_type_value(show, "%u", v);
4164	btf_show_end_type(show);
4165	}
4166
4167	static struct btf_kind_operations enum_ops = {
4168	.check_meta = btf_enum_check_meta,
4169	.resolve = btf_df_resolve,
4170	.check_member = btf_enum_check_member,
4171	.check_kflag_member = btf_enum_check_kflag_member,
4172	.log_details = btf_enum_log,
4173	.show = btf_enum_show,
4174	};
4175
4176	static s32 btf_enum64_check_meta(struct btf_verifier_env *env,
4177	const struct btf_type *t,
4178	u32 meta_left)
4179	{
4180	const struct btf_enum64 *enums = btf_type_enum64(t);
4181	struct btf *btf = env->btf;
4182	const char *fmt_str;
4183	u16 i, nr_enums;
4184	u32 meta_needed;
4185
4186	nr_enums = btf_type_vlen(t);
4187	meta_needed = nr_enums * sizeof(*enums);
4188
4189	if (meta_left < meta_needed) {
4190	btf_verifier_log_basic(env, t,
4191	"meta_left:%u meta_needed:%u",
4192	meta_left, meta_needed);
4193	return -EINVAL;
4194	}
4195
4196	if (t->size > 8 || !is_power_of_2(n: t->size)) {
4197	btf_verifier_log_type(env, t, "Unexpected size");
4198	return -EINVAL;
4199	}
4200
4201	/* enum type either no name or a valid one */
4202	if (t->name_off &&
4203	!btf_name_valid_identifier(btf: env->btf, offset: t->name_off)) {
4204	btf_verifier_log_type(env, t, "Invalid name");
4205	return -EINVAL;
4206	}
4207
4208	btf_verifier_log_type(env, t, NULL);
4209
4210	for (i = 0; i < nr_enums; i++) {
4211	if (!btf_name_offset_valid(btf, offset: enums[i].name_off)) {
4212	btf_verifier_log(env, fmt: "\tInvalid name_offset:%u",
4213	enums[i].name_off);
4214	return -EINVAL;
4215	}
4216
4217	/* enum member must have a valid name */
4218	if (!enums[i].name_off ||
4219	!btf_name_valid_identifier(btf, offset: enums[i].name_off)) {
4220	btf_verifier_log_type(env, t, "Invalid name");
4221	return -EINVAL;
4222	}
4223
4224	if (env->log.level == BPF_LOG_KERNEL)
4225	continue;
4226
4227	fmt_str = btf_type_kflag(t) ? "\t%s val=%lld\n" : "\t%s val=%llu\n";
4228	btf_verifier_log(env, fmt: fmt_str,
4229	__btf_name_by_offset(btf, offset: enums[i].name_off),
4230	btf_enum64_value(e: enums + i));
4231	}
4232
4233	return meta_needed;
4234	}
4235
4236	static void btf_enum64_show(const struct btf *btf, const struct btf_type *t,
4237	u32 type_id, void *data, u8 bits_offset,
4238	struct btf_show *show)
4239	{
4240	const struct btf_enum64 *enums = btf_type_enum64(t);
4241	u32 i, nr_enums = btf_type_vlen(t);
4242	void *safe_data;
4243	s64 v;
4244
4245	safe_data = btf_show_start_type(show, t, type_id, data);
4246	if (!safe_data)
4247	return;
4248
4249	v = *(u64 *)safe_data;
4250
4251	for (i = 0; i < nr_enums; i++) {
4252	if (v != btf_enum64_value(e: enums + i))
4253	continue;
4254
4255	btf_show_type_value(show, "%s",
4256	__btf_name_by_offset(btf,
4257	enums[i].name_off));
4258
4259	btf_show_end_type(show);
4260	return;
4261	}
4262
4263	if (btf_type_kflag(t))
4264	btf_show_type_value(show, "%lld", v);
4265	else
4266	btf_show_type_value(show, "%llu", v);
4267	btf_show_end_type(show);
4268	}
4269
4270	static struct btf_kind_operations enum64_ops = {
4271	.check_meta = btf_enum64_check_meta,
4272	.resolve = btf_df_resolve,
4273	.check_member = btf_enum_check_member,
4274	.check_kflag_member = btf_enum_check_kflag_member,
4275	.log_details = btf_enum_log,
4276	.show = btf_enum64_show,
4277	};
4278
4279	static s32 btf_func_proto_check_meta(struct btf_verifier_env *env,
4280	const struct btf_type *t,
4281	u32 meta_left)
4282	{
4283	u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param);
4284
4285	if (meta_left < meta_needed) {
4286	btf_verifier_log_basic(env, t,
4287	"meta_left:%u meta_needed:%u",
4288	meta_left, meta_needed);
4289	return -EINVAL;
4290	}
4291
4292	if (t->name_off) {
4293	btf_verifier_log_type(env, t, "Invalid name");
4294	return -EINVAL;
4295	}
4296
4297	if (btf_type_kflag(t)) {
4298	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4299	return -EINVAL;
4300	}
4301
4302	btf_verifier_log_type(env, t, NULL);
4303
4304	return meta_needed;
4305	}
4306
4307	static void btf_func_proto_log(struct btf_verifier_env *env,
4308	const struct btf_type *t)
4309	{
4310	const struct btf_param *args = (const struct btf_param *)(t + 1);
4311	u16 nr_args = btf_type_vlen(t), i;
4312
4313	btf_verifier_log(env, fmt: "return=%u args=(", t->type);
4314	if (!nr_args) {
4315	btf_verifier_log(env, fmt: "void");
4316	goto done;
4317	}
4318
4319	if (nr_args == 1 && !args[0].type) {
4320	/* Only one vararg */
4321	btf_verifier_log(env, fmt: "vararg");
4322	goto done;
4323	}
4324
4325	btf_verifier_log(env, fmt: "%u %s", args[0].type,
4326	__btf_name_by_offset(btf: env->btf,
4327	offset: args[0].name_off));
4328	for (i = 1; i < nr_args - 1; i++)
4329	btf_verifier_log(env, fmt: ", %u %s", args[i].type,
4330	__btf_name_by_offset(btf: env->btf,
4331	offset: args[i].name_off));
4332
4333	if (nr_args > 1) {
4334	const struct btf_param *last_arg = &args[nr_args - 1];
4335
4336	if (last_arg->type)
4337	btf_verifier_log(env, fmt: ", %u %s", last_arg->type,
4338	__btf_name_by_offset(btf: env->btf,
4339	offset: last_arg->name_off));
4340	else
4341	btf_verifier_log(env, fmt: ", vararg");
4342	}
4343
4344	done:
4345	btf_verifier_log(env, fmt: ")");
4346	}
4347
4348	static struct btf_kind_operations func_proto_ops = {
4349	.check_meta = btf_func_proto_check_meta,
4350	.resolve = btf_df_resolve,
4351	/*
4352	* BTF_KIND_FUNC_PROTO cannot be directly referred by
4353	* a struct's member.
4354	*
4355	* It should be a function pointer instead.
4356	* (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO)
4357	*
4358	* Hence, there is no btf_func_check_member().
4359	*/
4360	.check_member = btf_df_check_member,
4361	.check_kflag_member = btf_df_check_kflag_member,
4362	.log_details = btf_func_proto_log,
4363	.show = btf_df_show,
4364	};
4365
4366	static s32 btf_func_check_meta(struct btf_verifier_env *env,
4367	const struct btf_type *t,
4368	u32 meta_left)
4369	{
4370	if (!t->name_off ||
4371	!btf_name_valid_identifier(btf: env->btf, offset: t->name_off)) {
4372	btf_verifier_log_type(env, t, "Invalid name");
4373	return -EINVAL;
4374	}
4375
4376	if (btf_type_vlen(t) > BTF_FUNC_GLOBAL) {
4377	btf_verifier_log_type(env, t, "Invalid func linkage");
4378	return -EINVAL;
4379	}
4380
4381	if (btf_type_kflag(t)) {
4382	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4383	return -EINVAL;
4384	}
4385
4386	btf_verifier_log_type(env, t, NULL);
4387
4388	return 0;
4389	}
4390
4391	static int btf_func_resolve(struct btf_verifier_env *env,
4392	const struct resolve_vertex *v)
4393	{
4394	const struct btf_type *t = v->t;
4395	u32 next_type_id = t->type;
4396	int err;
4397
4398	err = btf_func_check(env, t);
4399	if (err)
4400	return err;
4401
4402	env_stack_pop_resolved(env, resolved_type_id: next_type_id, resolved_size: 0);
4403	return 0;
4404	}
4405
4406	static struct btf_kind_operations func_ops = {
4407	.check_meta = btf_func_check_meta,
4408	.resolve = btf_func_resolve,
4409	.check_member = btf_df_check_member,
4410	.check_kflag_member = btf_df_check_kflag_member,
4411	.log_details = btf_ref_type_log,
4412	.show = btf_df_show,
4413	};
4414
4415	static s32 btf_var_check_meta(struct btf_verifier_env *env,
4416	const struct btf_type *t,
4417	u32 meta_left)
4418	{
4419	const struct btf_var *var;
4420	u32 meta_needed = sizeof(*var);
4421
4422	if (meta_left < meta_needed) {
4423	btf_verifier_log_basic(env, t,
4424	"meta_left:%u meta_needed:%u",
4425	meta_left, meta_needed);
4426	return -EINVAL;
4427	}
4428
4429	if (btf_type_vlen(t)) {
4430	btf_verifier_log_type(env, t, "vlen != 0");
4431	return -EINVAL;
4432	}
4433
4434	if (btf_type_kflag(t)) {
4435	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4436	return -EINVAL;
4437	}
4438
4439	if (!t->name_off ||
4440	!__btf_name_valid(btf: env->btf, offset: t->name_off)) {
4441	btf_verifier_log_type(env, t, "Invalid name");
4442	return -EINVAL;
4443	}
4444
4445	/* A var cannot be in type void */
4446	if (!t->type || !BTF_TYPE_ID_VALID(t->type)) {
4447	btf_verifier_log_type(env, t, "Invalid type_id");
4448	return -EINVAL;
4449	}
4450
4451	var = btf_type_var(t);
4452	if (var->linkage != BTF_VAR_STATIC &&
4453	var->linkage != BTF_VAR_GLOBAL_ALLOCATED) {
4454	btf_verifier_log_type(env, t, "Linkage not supported");
4455	return -EINVAL;
4456	}
4457
4458	btf_verifier_log_type(env, t, NULL);
4459
4460	return meta_needed;
4461	}
4462
4463	static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t)
4464	{
4465	const struct btf_var *var = btf_type_var(t);
4466
4467	btf_verifier_log(env, fmt: "type_id=%u linkage=%u", t->type, var->linkage);
4468	}
4469
4470	static const struct btf_kind_operations var_ops = {
4471	.check_meta = btf_var_check_meta,
4472	.resolve = btf_var_resolve,
4473	.check_member = btf_df_check_member,
4474	.check_kflag_member = btf_df_check_kflag_member,
4475	.log_details = btf_var_log,
4476	.show = btf_var_show,
4477	};
4478
4479	static s32 btf_datasec_check_meta(struct btf_verifier_env *env,
4480	const struct btf_type *t,
4481	u32 meta_left)
4482	{
4483	const struct btf_var_secinfo *vsi;
4484	u64 last_vsi_end_off = 0, sum = 0;
4485	u32 i, meta_needed;
4486
4487	meta_needed = btf_type_vlen(t) * sizeof(*vsi);
4488	if (meta_left < meta_needed) {
4489	btf_verifier_log_basic(env, t,
4490	"meta_left:%u meta_needed:%u",
4491	meta_left, meta_needed);
4492	return -EINVAL;
4493	}
4494
4495	if (!t->size) {
4496	btf_verifier_log_type(env, t, "size == 0");
4497	return -EINVAL;
4498	}
4499
4500	if (btf_type_kflag(t)) {
4501	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4502	return -EINVAL;
4503	}
4504
4505	if (!t->name_off ||
4506	!btf_name_valid_section(btf: env->btf, offset: t->name_off)) {
4507	btf_verifier_log_type(env, t, "Invalid name");
4508	return -EINVAL;
4509	}
4510
4511	btf_verifier_log_type(env, t, NULL);
4512
4513	for_each_vsi(i, t, vsi) {
4514	/* A var cannot be in type void */
4515	if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) {
4516	btf_verifier_log_vsi(env, datasec_type: t, vsi,
4517	fmt: "Invalid type_id");
4518	return -EINVAL;
4519	}
4520
4521	if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) {
4522	btf_verifier_log_vsi(env, datasec_type: t, vsi,
4523	fmt: "Invalid offset");
4524	return -EINVAL;
4525	}
4526
4527	if (!vsi->size || vsi->size > t->size) {
4528	btf_verifier_log_vsi(env, datasec_type: t, vsi,
4529	fmt: "Invalid size");
4530	return -EINVAL;
4531	}
4532
4533	last_vsi_end_off = vsi->offset + vsi->size;
4534	if (last_vsi_end_off > t->size) {
4535	btf_verifier_log_vsi(env, datasec_type: t, vsi,
4536	fmt: "Invalid offset+size");
4537	return -EINVAL;
4538	}
4539
4540	btf_verifier_log_vsi(env, datasec_type: t, vsi, NULL);
4541	sum += vsi->size;
4542	}
4543
4544	if (t->size < sum) {
4545	btf_verifier_log_type(env, t, "Invalid btf_info size");
4546	return -EINVAL;
4547	}
4548
4549	return meta_needed;
4550	}
4551
4552	static int btf_datasec_resolve(struct btf_verifier_env *env,
4553	const struct resolve_vertex *v)
4554	{
4555	const struct btf_var_secinfo *vsi;
4556	struct btf *btf = env->btf;
4557	u16 i;
4558
4559	env->resolve_mode = RESOLVE_TBD;
4560	for_each_vsi_from(i, v->next_member, v->t, vsi) {
4561	u32 var_type_id = vsi->type, type_id, type_size = 0;
4562	const struct btf_type *var_type = btf_type_by_id(env->btf,
4563	var_type_id);
4564	if (!var_type || !btf_type_is_var(t: var_type)) {
4565	btf_verifier_log_vsi(env, datasec_type: v->t, vsi,
4566	fmt: "Not a VAR kind member");
4567	return -EINVAL;
4568	}
4569
4570	if (!env_type_is_resolve_sink(env, next_type: var_type) &&
4571	!env_type_is_resolved(env, type_id: var_type_id)) {
4572	env_stack_set_next_member(env, next_member: i + 1);
4573	return env_stack_push(env, t: var_type, type_id: var_type_id);
4574	}
4575
4576	type_id = var_type->type;
4577	if (!btf_type_id_size(btf, type_id: &type_id, ret_size: &type_size)) {
4578	btf_verifier_log_vsi(env, datasec_type: v->t, vsi, fmt: "Invalid type");
4579	return -EINVAL;
4580	}
4581
4582	if (vsi->size < type_size) {
4583	btf_verifier_log_vsi(env, datasec_type: v->t, vsi, fmt: "Invalid size");
4584	return -EINVAL;
4585	}
4586	}
4587
4588	env_stack_pop_resolved(env, resolved_type_id: 0, resolved_size: 0);
4589	return 0;
4590	}
4591
4592	static void btf_datasec_log(struct btf_verifier_env *env,
4593	const struct btf_type *t)
4594	{
4595	btf_verifier_log(env, fmt: "size=%u vlen=%u", t->size, btf_type_vlen(t));
4596	}
4597
4598	static void btf_datasec_show(const struct btf *btf,
4599	const struct btf_type *t, u32 type_id,
4600	void *data, u8 bits_offset,
4601	struct btf_show *show)
4602	{
4603	const struct btf_var_secinfo *vsi;
4604	const struct btf_type *var;
4605	u32 i;
4606
4607	if (!btf_show_start_type(show, t, type_id, data))
4608	return;
4609
4610	btf_show_type_value(show, "section (\"%s\") = {",
4611	__btf_name_by_offset(btf, t->name_off));
4612	for_each_vsi(i, t, vsi) {
4613	var = btf_type_by_id(btf, vsi->type);
4614	if (i)
4615	btf_show(show, fmt: ",");
4616	btf_type_ops(t: var)->show(btf, var, vsi->type,
4617	data + vsi->offset, bits_offset, show);
4618	}
4619	btf_show_end_type(show);
4620	}
4621
4622	static const struct btf_kind_operations datasec_ops = {
4623	.check_meta = btf_datasec_check_meta,
4624	.resolve = btf_datasec_resolve,
4625	.check_member = btf_df_check_member,
4626	.check_kflag_member = btf_df_check_kflag_member,
4627	.log_details = btf_datasec_log,
4628	.show = btf_datasec_show,
4629	};
4630
4631	static s32 btf_float_check_meta(struct btf_verifier_env *env,
4632	const struct btf_type *t,
4633	u32 meta_left)
4634	{
4635	if (btf_type_vlen(t)) {
4636	btf_verifier_log_type(env, t, "vlen != 0");
4637	return -EINVAL;
4638	}
4639
4640	if (btf_type_kflag(t)) {
4641	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4642	return -EINVAL;
4643	}
4644
4645	if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 &&
4646	t->size != 16) {
4647	btf_verifier_log_type(env, t, "Invalid type_size");
4648	return -EINVAL;
4649	}
4650
4651	btf_verifier_log_type(env, t, NULL);
4652
4653	return 0;
4654	}
4655
4656	static int btf_float_check_member(struct btf_verifier_env *env,
4657	const struct btf_type *struct_type,
4658	const struct btf_member *member,
4659	const struct btf_type *member_type)
4660	{
4661	u64 start_offset_bytes;
4662	u64 end_offset_bytes;
4663	u64 misalign_bits;
4664	u64 align_bytes;
4665	u64 align_bits;
4666
4667	/* Different architectures have different alignment requirements, so
4668	* here we check only for the reasonable minimum. This way we ensure
4669	* that types after CO-RE can pass the kernel BTF verifier.
4670	*/
4671	align_bytes = min_t(u64, sizeof(void *), member_type->size);
4672	align_bits = align_bytes * BITS_PER_BYTE;
4673	div64_u64_rem(dividend: member->offset, divisor: align_bits, remainder: &misalign_bits);
4674	if (misalign_bits) {
4675	btf_verifier_log_member(env, struct_type, member,
4676	fmt: "Member is not properly aligned");
4677	return -EINVAL;
4678	}
4679
4680	start_offset_bytes = member->offset / BITS_PER_BYTE;
4681	end_offset_bytes = start_offset_bytes + member_type->size;
4682	if (end_offset_bytes > struct_type->size) {
4683	btf_verifier_log_member(env, struct_type, member,
4684	fmt: "Member exceeds struct_size");
4685	return -EINVAL;
4686	}
4687
4688	return 0;
4689	}
4690
4691	static void btf_float_log(struct btf_verifier_env *env,
4692	const struct btf_type *t)
4693	{
4694	btf_verifier_log(env, fmt: "size=%u", t->size);
4695	}
4696
4697	static const struct btf_kind_operations float_ops = {
4698	.check_meta = btf_float_check_meta,
4699	.resolve = btf_df_resolve,
4700	.check_member = btf_float_check_member,
4701	.check_kflag_member = btf_generic_check_kflag_member,
4702	.log_details = btf_float_log,
4703	.show = btf_df_show,
4704	};
4705
4706	static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env,
4707	const struct btf_type *t,
4708	u32 meta_left)
4709	{
4710	const struct btf_decl_tag *tag;
4711	u32 meta_needed = sizeof(*tag);
4712	s32 component_idx;
4713	const char *value;
4714
4715	if (meta_left < meta_needed) {
4716	btf_verifier_log_basic(env, t,
4717	"meta_left:%u meta_needed:%u",
4718	meta_left, meta_needed);
4719	return -EINVAL;
4720	}
4721
4722	value = btf_name_by_offset(btf: env->btf, offset: t->name_off);
4723	if (!value || !value[0]) {
4724	btf_verifier_log_type(env, t, "Invalid value");
4725	return -EINVAL;
4726	}
4727
4728	if (btf_type_vlen(t)) {
4729	btf_verifier_log_type(env, t, "vlen != 0");
4730	return -EINVAL;
4731	}
4732
4733	if (btf_type_kflag(t)) {
4734	btf_verifier_log_type(env, t, "Invalid btf_info kind_flag");
4735	return -EINVAL;
4736	}
4737
4738	component_idx = btf_type_decl_tag(t)->component_idx;
4739	if (component_idx < -1) {
4740	btf_verifier_log_type(env, t, "Invalid component_idx");
4741	return -EINVAL;
4742	}
4743
4744	btf_verifier_log_type(env, t, NULL);
4745
4746	return meta_needed;
4747	}
4748
4749	static int btf_decl_tag_resolve(struct btf_verifier_env *env,
4750	const struct resolve_vertex *v)
4751	{
4752	const struct btf_type *next_type;
4753	const struct btf_type *t = v->t;
4754	u32 next_type_id = t->type;
4755	struct btf *btf = env->btf;
4756	s32 component_idx;
4757	u32 vlen;
4758
4759	next_type = btf_type_by_id(btf, next_type_id);
4760	if (!next_type || !btf_type_is_decl_tag_target(t: next_type)) {
4761	btf_verifier_log_type(env, v->t, "Invalid type_id");
4762	return -EINVAL;
4763	}
4764
4765	if (!env_type_is_resolve_sink(env, next_type) &&
4766	!env_type_is_resolved(env, type_id: next_type_id))
4767	return env_stack_push(env, t: next_type, type_id: next_type_id);
4768
4769	component_idx = btf_type_decl_tag(t)->component_idx;
4770	if (component_idx != -1) {
4771	if (btf_type_is_var(t: next_type) || btf_type_is_typedef(t: next_type)) {
4772	btf_verifier_log_type(env, v->t, "Invalid component_idx");
4773	return -EINVAL;
4774	}
4775
4776	if (btf_type_is_struct(t: next_type)) {
4777	vlen = btf_type_vlen(t: next_type);
4778	} else {
4779	/* next_type should be a function */
4780	next_type = btf_type_by_id(btf, next_type->type);
4781	vlen = btf_type_vlen(t: next_type);
4782	}
4783
4784	if ((u32)component_idx >= vlen) {
4785	btf_verifier_log_type(env, v->t, "Invalid component_idx");
4786	return -EINVAL;
4787	}
4788	}
4789
4790	env_stack_pop_resolved(env, resolved_type_id: next_type_id, resolved_size: 0);
4791
4792	return 0;
4793	}
4794
4795	static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t)
4796	{
4797	btf_verifier_log(env, fmt: "type=%u component_idx=%d", t->type,
4798	btf_type_decl_tag(t)->component_idx);
4799	}
4800
4801	static const struct btf_kind_operations decl_tag_ops = {
4802	.check_meta = btf_decl_tag_check_meta,
4803	.resolve = btf_decl_tag_resolve,
4804	.check_member = btf_df_check_member,
4805	.check_kflag_member = btf_df_check_kflag_member,
4806	.log_details = btf_decl_tag_log,
4807	.show = btf_df_show,
4808	};
4809
4810	static int btf_func_proto_check(struct btf_verifier_env *env,
4811	const struct btf_type *t)
4812	{
4813	const struct btf_type *ret_type;
4814	const struct btf_param *args;
4815	const struct btf *btf;
4816	u16 nr_args, i;
4817	int err;
4818
4819	btf = env->btf;
4820	args = (const struct btf_param *)(t + 1);
4821	nr_args = btf_type_vlen(t);
4822
4823	/* Check func return type which could be "void" (t->type == 0) */
4824	if (t->type) {
4825	u32 ret_type_id = t->type;
4826
4827	ret_type = btf_type_by_id(btf, ret_type_id);
4828	if (!ret_type) {
4829	btf_verifier_log_type(env, t, "Invalid return type");
4830	return -EINVAL;
4831	}
4832
4833	if (btf_type_is_resolve_source_only(t: ret_type)) {
4834	btf_verifier_log_type(env, t, "Invalid return type");
4835	return -EINVAL;
4836	}
4837
4838	if (btf_type_needs_resolve(t: ret_type) &&
4839	!env_type_is_resolved(env, type_id: ret_type_id)) {
4840	err = btf_resolve(env, t: ret_type, type_id: ret_type_id);
4841	if (err)
4842	return err;
4843	}
4844
4845	/* Ensure the return type is a type that has a size */
4846	if (!btf_type_id_size(btf, type_id: &ret_type_id, NULL)) {
4847	btf_verifier_log_type(env, t, "Invalid return type");
4848	return -EINVAL;
4849	}
4850	}
4851
4852	if (!nr_args)
4853	return 0;
4854
4855	/* Last func arg type_id could be 0 if it is a vararg */
4856	if (!args[nr_args - 1].type) {
4857	if (args[nr_args - 1].name_off) {
4858	btf_verifier_log_type(env, t, "Invalid arg#%u",
4859	nr_args);
4860	return -EINVAL;
4861	}
4862	nr_args--;
4863	}
4864
4865	for (i = 0; i < nr_args; i++) {
4866	const struct btf_type *arg_type;
4867	u32 arg_type_id;
4868
4869	arg_type_id = args[i].type;
4870	arg_type = btf_type_by_id(btf, arg_type_id);
4871	if (!arg_type) {
4872	btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
4873	return -EINVAL;
4874	}
4875
4876	if (btf_type_is_resolve_source_only(t: arg_type)) {
4877	btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
4878	return -EINVAL;
4879	}
4880
4881	if (args[i].name_off &&
4882	(!btf_name_offset_valid(btf, offset: args[i].name_off) ||
4883	!btf_name_valid_identifier(btf, offset: args[i].name_off))) {
4884	btf_verifier_log_type(env, t,
4885	"Invalid arg#%u", i + 1);
4886	return -EINVAL;
4887	}
4888
4889	if (btf_type_needs_resolve(t: arg_type) &&
4890	!env_type_is_resolved(env, type_id: arg_type_id)) {
4891	err = btf_resolve(env, t: arg_type, type_id: arg_type_id);
4892	if (err)
4893	return err;
4894	}
4895
4896	if (!btf_type_id_size(btf, type_id: &arg_type_id, NULL)) {
4897	btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
4898	return -EINVAL;
4899	}
4900	}
4901
4902	return 0;
4903	}
4904
4905	static int btf_func_check(struct btf_verifier_env *env,
4906	const struct btf_type *t)
4907	{
4908	const struct btf_type *proto_type;
4909	const struct btf_param *args;
4910	const struct btf *btf;
4911	u16 nr_args, i;
4912
4913	btf = env->btf;
4914	proto_type = btf_type_by_id(btf, t->type);
4915
4916	if (!proto_type || !btf_type_is_func_proto(t: proto_type)) {
4917	btf_verifier_log_type(env, t, "Invalid type_id");
4918	return -EINVAL;
4919	}
4920
4921	args = (const struct btf_param *)(proto_type + 1);
4922	nr_args = btf_type_vlen(t: proto_type);
4923	for (i = 0; i < nr_args; i++) {
4924	if (!args[i].name_off && args[i].type) {
4925	btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
4926	return -EINVAL;
4927	}
4928	}
4929
4930	return 0;
4931	}
4932
4933	static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
4934	[BTF_KIND_INT] = &int_ops,
4935	[BTF_KIND_PTR] = &ptr_ops,
4936	[BTF_KIND_ARRAY] = &array_ops,
4937	[BTF_KIND_STRUCT] = &struct_ops,
4938	[BTF_KIND_UNION] = &struct_ops,
4939	[BTF_KIND_ENUM] = &enum_ops,
4940	[BTF_KIND_FWD] = &fwd_ops,
4941	[BTF_KIND_TYPEDEF] = &modifier_ops,
4942	[BTF_KIND_VOLATILE] = &modifier_ops,
4943	[BTF_KIND_CONST] = &modifier_ops,
4944	[BTF_KIND_RESTRICT] = &modifier_ops,
4945	[BTF_KIND_FUNC] = &func_ops,
4946	[BTF_KIND_FUNC_PROTO] = &func_proto_ops,
4947	[BTF_KIND_VAR] = &var_ops,
4948	[BTF_KIND_DATASEC] = &datasec_ops,
4949	[BTF_KIND_FLOAT] = &float_ops,
4950	[BTF_KIND_DECL_TAG] = &decl_tag_ops,
4951	[BTF_KIND_TYPE_TAG] = &modifier_ops,
4952	[BTF_KIND_ENUM64] = &enum64_ops,
4953	};
4954
4955	static s32 btf_check_meta(struct btf_verifier_env *env,
4956	const struct btf_type *t,
4957	u32 meta_left)
4958	{
4959	u32 saved_meta_left = meta_left;
4960	s32 var_meta_size;
4961
4962	if (meta_left < sizeof(*t)) {
4963	btf_verifier_log(env, fmt: "[%u] meta_left:%u meta_needed:%zu",
4964	env->log_type_id, meta_left, sizeof(*t));
4965	return -EINVAL;
4966	}
4967	meta_left -= sizeof(*t);
4968
4969	if (t->info & ~BTF_INFO_MASK) {
4970	btf_verifier_log(env, fmt: "[%u] Invalid btf_info:%x",
4971	env->log_type_id, t->info);
4972	return -EINVAL;
4973	}
4974
4975	if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX ||
4976	BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) {
4977	btf_verifier_log(env, fmt: "[%u] Invalid kind:%u",
4978	env->log_type_id, BTF_INFO_KIND(t->info));
4979	return -EINVAL;
4980	}
4981
4982	if (!btf_name_offset_valid(btf: env->btf, offset: t->name_off)) {
4983	btf_verifier_log(env, fmt: "[%u] Invalid name_offset:%u",
4984	env->log_type_id, t->name_off);
4985	return -EINVAL;
4986	}
4987
4988	var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left);
4989	if (var_meta_size < 0)
4990	return var_meta_size;
4991
4992	meta_left -= var_meta_size;
4993
4994	return saved_meta_left - meta_left;
4995	}
4996
4997	static int btf_check_all_metas(struct btf_verifier_env *env)
4998	{
4999	struct btf *btf = env->btf;
5000	struct btf_header *hdr;
5001	void *cur, *end;
5002
5003	hdr = &btf->hdr;
5004	cur = btf->nohdr_data + hdr->type_off;
5005	end = cur + hdr->type_len;
5006
5007	env->log_type_id = btf->base_btf ? btf->start_id : 1;
5008	while (cur < end) {
5009	struct btf_type *t = cur;
5010	s32 meta_size;
5011
5012	meta_size = btf_check_meta(env, t, meta_left: end - cur);
5013	if (meta_size < 0)
5014	return meta_size;
5015
5016	btf_add_type(env, t);
5017	cur += meta_size;
5018	env->log_type_id++;
5019	}
5020
5021	return 0;
5022	}
5023
5024	static bool btf_resolve_valid(struct btf_verifier_env *env,
5025	const struct btf_type *t,
5026	u32 type_id)
5027	{
5028	struct btf *btf = env->btf;
5029
5030	if (!env_type_is_resolved(env, type_id))
5031	return false;
5032
5033	if (btf_type_is_struct(t) || btf_type_is_datasec(t))
5034	return !btf_resolved_type_id(btf, type_id) &&
5035	!btf_resolved_type_size(btf, type_id);
5036
5037	if (btf_type_is_decl_tag(t) || btf_type_is_func(t))
5038	return btf_resolved_type_id(btf, type_id) &&
5039	!btf_resolved_type_size(btf, type_id);
5040
5041	if (btf_type_is_modifier(t) || btf_type_is_ptr(t) ||
5042	btf_type_is_var(t)) {
5043	t = btf_type_id_resolve(btf, type_id: &type_id);
5044	return t &&
5045	!btf_type_is_modifier(t) &&
5046	!btf_type_is_var(t) &&
5047	!btf_type_is_datasec(t);
5048	}
5049
5050	if (btf_type_is_array(t)) {
5051	const struct btf_array *array = btf_type_array(t);
5052	const struct btf_type *elem_type;
5053	u32 elem_type_id = array->type;
5054	u32 elem_size;
5055
5056	elem_type = btf_type_id_size(btf, type_id: &elem_type_id, ret_size: &elem_size);
5057	return elem_type && !btf_type_is_modifier(t: elem_type) &&
5058	(array->nelems * elem_size ==
5059	btf_resolved_type_size(btf, type_id));
5060	}
5061
5062	return false;
5063	}
5064
5065	static int btf_resolve(struct btf_verifier_env *env,
5066	const struct btf_type *t, u32 type_id)
5067	{
5068	u32 save_log_type_id = env->log_type_id;
5069	const struct resolve_vertex *v;
5070	int err = 0;
5071
5072	env->resolve_mode = RESOLVE_TBD;
5073	env_stack_push(env, t, type_id);
5074	while (!err && (v = env_stack_peak(env))) {
5075	env->log_type_id = v->type_id;
5076	err = btf_type_ops(t: v->t)->resolve(env, v);
5077	}
5078
5079	env->log_type_id = type_id;
5080	if (err == -E2BIG) {
5081	btf_verifier_log_type(env, t,
5082	"Exceeded max resolving depth:%u",
5083	MAX_RESOLVE_DEPTH);
5084	} else if (err == -EEXIST) {
5085	btf_verifier_log_type(env, t, "Loop detected");
5086	}
5087
5088	/* Final sanity check */
5089	if (!err && !btf_resolve_valid(env, t, type_id)) {
5090	btf_verifier_log_type(env, t, "Invalid resolve state");
5091	err = -EINVAL;
5092	}
5093
5094	env->log_type_id = save_log_type_id;
5095	return err;
5096	}
5097
5098	static int btf_check_all_types(struct btf_verifier_env *env)
5099	{
5100	struct btf *btf = env->btf;
5101	const struct btf_type *t;
5102	u32 type_id, i;
5103	int err;
5104
5105	err = env_resolve_init(env);
5106	if (err)
5107	return err;
5108
5109	env->phase++;
5110	for (i = btf->base_btf ? 0 : 1; i < btf->nr_types; i++) {
5111	type_id = btf->start_id + i;
5112	t = btf_type_by_id(btf, type_id);
5113
5114	env->log_type_id = type_id;
5115	if (btf_type_needs_resolve(t) &&
5116	!env_type_is_resolved(env, type_id)) {
5117	err = btf_resolve(env, t, type_id);
5118	if (err)
5119	return err;
5120	}
5121
5122	if (btf_type_is_func_proto(t)) {
5123	err = btf_func_proto_check(env, t);
5124	if (err)
5125	return err;
5126	}
5127	}
5128
5129	return 0;
5130	}
5131
5132	static int btf_parse_type_sec(struct btf_verifier_env *env)
5133	{
5134	const struct btf_header *hdr = &env->btf->hdr;
5135	int err;
5136
5137	/* Type section must align to 4 bytes */
5138	if (hdr->type_off & (sizeof(u32) - 1)) {
5139	btf_verifier_log(env, fmt: "Unaligned type_off");
5140	return -EINVAL;
5141	}
5142
5143	if (!env->btf->base_btf && !hdr->type_len) {
5144	btf_verifier_log(env, fmt: "No type found");
5145	return -EINVAL;
5146	}
5147
5148	err = btf_check_all_metas(env);
5149	if (err)
5150	return err;
5151
5152	return btf_check_all_types(env);
5153	}
5154
5155	static int btf_parse_str_sec(struct btf_verifier_env *env)
5156	{
5157	const struct btf_header *hdr;
5158	struct btf *btf = env->btf;
5159	const char *start, *end;
5160
5161	hdr = &btf->hdr;
5162	start = btf->nohdr_data + hdr->str_off;
5163	end = start + hdr->str_len;
5164
5165	if (end != btf->data + btf->data_size) {
5166	btf_verifier_log(env, fmt: "String section is not at the end");
5167	return -EINVAL;
5168	}
5169
5170	btf->strings = start;
5171
5172	if (btf->base_btf && !hdr->str_len)
5173	return 0;
5174	if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || end[-1]) {
5175	btf_verifier_log(env, fmt: "Invalid string section");
5176	return -EINVAL;
5177	}
5178	if (!btf->base_btf && start[0]) {
5179	btf_verifier_log(env, fmt: "Invalid string section");
5180	return -EINVAL;
5181	}
5182
5183	return 0;
5184	}
5185
5186	static const size_t btf_sec_info_offset[] = {
5187	offsetof(struct btf_header, type_off),
5188	offsetof(struct btf_header, str_off),
5189	};
5190
5191	static int btf_sec_info_cmp(const void *a, const void *b)
5192	{
5193	const struct btf_sec_info *x = a;
5194	const struct btf_sec_info *y = b;
5195
5196	return (int)(x->off - y->off) ? : (int)(x->len - y->len);
5197	}
5198
5199	static int btf_check_sec_info(struct btf_verifier_env *env,
5200	u32 btf_data_size)
5201	{
5202	struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
5203	u32 total, expected_total, i;
5204	const struct btf_header *hdr;
5205	const struct btf *btf;
5206
5207	btf = env->btf;
5208	hdr = &btf->hdr;
5209
5210	/* Populate the secs from hdr */
5211	for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
5212	secs[i] = *(struct btf_sec_info *)((void *)hdr +
5213	btf_sec_info_offset[i]);
5214
5215	sort(base: secs, ARRAY_SIZE(btf_sec_info_offset),
5216	size: sizeof(struct btf_sec_info), cmp_func: btf_sec_info_cmp, NULL);
5217
5218	/* Check for gaps and overlap among sections */
5219	total = 0;
5220	expected_total = btf_data_size - hdr->hdr_len;
5221	for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
5222	if (expected_total < secs[i].off) {
5223	btf_verifier_log(env, fmt: "Invalid section offset");
5224	return -EINVAL;
5225	}
5226	if (total < secs[i].off) {
5227	/* gap */
5228	btf_verifier_log(env, fmt: "Unsupported section found");
5229	return -EINVAL;
5230	}
5231	if (total > secs[i].off) {
5232	btf_verifier_log(env, fmt: "Section overlap found");
5233	return -EINVAL;
5234	}
5235	if (expected_total - total < secs[i].len) {
5236	btf_verifier_log(env,
5237	fmt: "Total section length too long");
5238	return -EINVAL;
5239	}
5240	total += secs[i].len;
5241	}
5242
5243	/* There is data other than hdr and known sections */
5244	if (expected_total != total) {
5245	btf_verifier_log(env, fmt: "Unsupported section found");
5246	return -EINVAL;
5247	}
5248
5249	return 0;
5250	}
5251
5252	static int btf_parse_hdr(struct btf_verifier_env *env)
5253	{
5254	u32 hdr_len, hdr_copy, btf_data_size;
5255	const struct btf_header *hdr;
5256	struct btf *btf;
5257
5258	btf = env->btf;
5259	btf_data_size = btf->data_size;
5260
5261	if (btf_data_size < offsetofend(struct btf_header, hdr_len)) {
5262	btf_verifier_log(env, fmt: "hdr_len not found");
5263	return -EINVAL;
5264	}
5265
5266	hdr = btf->data;
5267	hdr_len = hdr->hdr_len;
5268	if (btf_data_size < hdr_len) {
5269	btf_verifier_log(env, fmt: "btf_header not found");
5270	return -EINVAL;
5271	}
5272
5273	/* Ensure the unsupported header fields are zero */
5274	if (hdr_len > sizeof(btf->hdr)) {
5275	u8 *expected_zero = btf->data + sizeof(btf->hdr);
5276	u8 *end = btf->data + hdr_len;
5277
5278	for (; expected_zero < end; expected_zero++) {
5279	if (*expected_zero) {
5280	btf_verifier_log(env, fmt: "Unsupported btf_header");
5281	return -E2BIG;
5282	}
5283	}
5284	}
5285
5286	hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
5287	memcpy(&btf->hdr, btf->data, hdr_copy);
5288
5289	hdr = &btf->hdr;
5290
5291	btf_verifier_log_hdr(env, btf_data_size);
5292
5293	if (hdr->magic != BTF_MAGIC) {
5294	btf_verifier_log(env, fmt: "Invalid magic");
5295	return -EINVAL;
5296	}
5297
5298	if (hdr->version != BTF_VERSION) {
5299	btf_verifier_log(env, fmt: "Unsupported version");
5300	return -ENOTSUPP;
5301	}
5302
5303	if (hdr->flags) {
5304	btf_verifier_log(env, fmt: "Unsupported flags");
5305	return -ENOTSUPP;
5306	}
5307
5308	if (!btf->base_btf && btf_data_size == hdr->hdr_len) {
5309	btf_verifier_log(env, fmt: "No data");
5310	return -EINVAL;
5311	}
5312
5313	return btf_check_sec_info(env, btf_data_size);
5314	}
5315
5316	static const char *alloc_obj_fields[] = {
5317	"bpf_spin_lock",
5318	"bpf_list_head",
5319	"bpf_list_node",
5320	"bpf_rb_root",
5321	"bpf_rb_node",
5322	"bpf_refcount",
5323	};
5324
5325	static struct btf_struct_metas *
5326	btf_parse_struct_metas(struct bpf_verifier_log *log, struct btf *btf)
5327	{
5328	union {
5329	struct btf_id_set set;
5330	struct {
5331	u32 _cnt;
5332	u32 _ids[ARRAY_SIZE(alloc_obj_fields)];
5333	} _arr;
5334	} aof;
5335	struct btf_struct_metas *tab = NULL;
5336	int i, n, id, ret;
5337
5338	BUILD_BUG_ON(offsetof(struct btf_id_set, cnt) != 0);
5339	BUILD_BUG_ON(sizeof(struct btf_id_set) != sizeof(u32));
5340
5341	memset(&aof, 0, sizeof(aof));
5342	for (i = 0; i < ARRAY_SIZE(alloc_obj_fields); i++) {
5343	/* Try to find whether this special type exists in user BTF, and
5344	* if so remember its ID so we can easily find it among members
5345	* of structs that we iterate in the next loop.
5346	*/
5347	id = btf_find_by_name_kind(btf, name: alloc_obj_fields[i], kind: BTF_KIND_STRUCT);
5348	if (id < 0)
5349	continue;
5350	aof.set.ids[aof.set.cnt++] = id;
5351	}
5352
5353	if (!aof.set.cnt)
5354	return NULL;
5355	sort(base: &aof.set.ids, num: aof.set.cnt, size: sizeof(aof.set.ids[0]), cmp_func: btf_id_cmp_func, NULL);
5356
5357	n = btf_nr_types(btf);
5358	for (i = 1; i < n; i++) {
5359	struct btf_struct_metas *new_tab;
5360	const struct btf_member *member;
5361	struct btf_struct_meta *type;
5362	struct btf_record *record;
5363	const struct btf_type *t;
5364	int j, tab_cnt;
5365
5366	t = btf_type_by_id(btf, i);
5367	if (!t) {
5368	ret = -EINVAL;
5369	goto free;
5370	}
5371	if (!__btf_type_is_struct(t))
5372	continue;
5373
5374	cond_resched();
5375
5376	for_each_member(j, t, member) {
5377	if (btf_id_set_contains(set: &aof.set, id: member->type))
5378	goto parse;
5379	}
5380	continue;
5381	parse:
5382	tab_cnt = tab ? tab->cnt : 0;
5383	new_tab = krealloc(objp: tab, offsetof(struct btf_struct_metas, types[tab_cnt + 1]),
5384	GFP_KERNEL | __GFP_NOWARN);
5385	if (!new_tab) {
5386	ret = -ENOMEM;
5387	goto free;
5388	}
5389	if (!tab)
5390	new_tab->cnt = 0;
5391	tab = new_tab;
5392
5393	type = &tab->types[tab->cnt];
5394	type->btf_id = i;
5395	record = btf_parse_fields(btf, t, field_mask: BPF_SPIN_LOCK | BPF_LIST_HEAD | BPF_LIST_NODE |
5396	BPF_RB_ROOT | BPF_RB_NODE | BPF_REFCOUNT, value_size: t->size);
5397	/* The record cannot be unset, treat it as an error if so */
5398	if (IS_ERR_OR_NULL(ptr: record)) {
5399	ret = PTR_ERR_OR_ZERO(ptr: record) ?: -EFAULT;
5400	goto free;
5401	}
5402	type->record = record;
5403	tab->cnt++;
5404	}
5405	return tab;
5406	free:
5407	btf_struct_metas_free(tab);
5408	return ERR_PTR(error: ret);
5409	}
5410
5411	struct btf_struct_meta *btf_find_struct_meta(const struct btf *btf, u32 btf_id)
5412	{
5413	struct btf_struct_metas *tab;
5414
5415	BUILD_BUG_ON(offsetof(struct btf_struct_meta, btf_id) != 0);
5416	tab = btf->struct_meta_tab;
5417	if (!tab)
5418	return NULL;
5419	return bsearch(key: &btf_id, base: tab->types, num: tab->cnt, size: sizeof(tab->types[0]), cmp: btf_id_cmp_func);
5420	}
5421
5422	static int btf_check_type_tags(struct btf_verifier_env *env,
5423	struct btf *btf, int start_id)
5424	{
5425	int i, n, good_id = start_id - 1;
5426	bool in_tags;
5427
5428	n = btf_nr_types(btf);
5429	for (i = start_id; i < n; i++) {
5430	const struct btf_type *t;
5431	int chain_limit = 32;
5432	u32 cur_id = i;
5433
5434	t = btf_type_by_id(btf, i);
5435	if (!t)
5436	return -EINVAL;
5437	if (!btf_type_is_modifier(t))
5438	continue;
5439
5440	cond_resched();
5441
5442	in_tags = btf_type_is_type_tag(t);
5443	while (btf_type_is_modifier(t)) {
5444	if (!chain_limit--) {
5445	btf_verifier_log(env, fmt: "Max chain length or cycle detected");
5446	return -ELOOP;
5447	}
5448	if (btf_type_is_type_tag(t)) {
5449	if (!in_tags) {
5450	btf_verifier_log(env, fmt: "Type tags don't precede modifiers");
5451	return -EINVAL;
5452	}
5453	} else if (in_tags) {
5454	in_tags = false;
5455	}
5456	if (cur_id <= good_id)
5457	break;
5458	/* Move to next type */
5459	cur_id = t->type;
5460	t = btf_type_by_id(btf, cur_id);
5461	if (!t)
5462	return -EINVAL;
5463	}
5464	good_id = i;
5465	}
5466	return 0;
5467	}
5468
5469	static int finalize_log(struct bpf_verifier_log *log, bpfptr_t uattr, u32 uattr_size)
5470	{
5471	u32 log_true_size;
5472	int err;
5473
5474	err = bpf_vlog_finalize(log, log_size_actual: &log_true_size);
5475
5476	if (uattr_size >= offsetofend(union bpf_attr, btf_log_true_size) &&
5477	copy_to_bpfptr_offset(dst: uattr, offsetof(union bpf_attr, btf_log_true_size),
5478	src: &log_true_size, size: sizeof(log_true_size)))
5479	err = -EFAULT;
5480
5481	return err;
5482	}
5483
5484	static struct btf *btf_parse(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
5485	{
5486	bpfptr_t btf_data = make_bpfptr(addr: attr->btf, is_kernel: uattr.is_kernel);
5487	char __user *log_ubuf = u64_to_user_ptr(attr->btf_log_buf);
5488	struct btf_struct_metas *struct_meta_tab;
5489	struct btf_verifier_env *env = NULL;
5490	struct btf *btf = NULL;
5491	u8 *data;
5492	int err, ret;
5493
5494	if (attr->btf_size > BTF_MAX_SIZE)
5495	return ERR_PTR(error: -E2BIG);
5496
5497	env = kzalloc(size: sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
5498	if (!env)
5499	return ERR_PTR(error: -ENOMEM);
5500
5501	/* user could have requested verbose verifier output
5502	* and supplied buffer to store the verification trace
5503	*/
5504	err = bpf_vlog_init(log: &env->log, log_level: attr->btf_log_level,
5505	log_buf: log_ubuf, log_size: attr->btf_log_size);
5506	if (err)
5507	goto errout_free;
5508
5509	btf = kzalloc(size: sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
5510	if (!btf) {
5511	err = -ENOMEM;
5512	goto errout;
5513	}
5514	env->btf = btf;
5515
5516	data = kvmalloc(size: attr->btf_size, GFP_KERNEL | __GFP_NOWARN);
5517	if (!data) {
5518	err = -ENOMEM;
5519	goto errout;
5520	}
5521
5522	btf->data = data;
5523	btf->data_size = attr->btf_size;
5524
5525	if (copy_from_bpfptr(dst: data, src: btf_data, size: attr->btf_size)) {
5526	err = -EFAULT;
5527	goto errout;
5528	}
5529
5530	err = btf_parse_hdr(env);
5531	if (err)
5532	goto errout;
5533
5534	btf->nohdr_data = btf->data + btf->hdr.hdr_len;
5535
5536	err = btf_parse_str_sec(env);
5537	if (err)
5538	goto errout;
5539
5540	err = btf_parse_type_sec(env);
5541	if (err)
5542	goto errout;
5543
5544	err = btf_check_type_tags(env, btf, start_id: 1);
5545	if (err)
5546	goto errout;
5547
5548	struct_meta_tab = btf_parse_struct_metas(log: &env->log, btf);
5549	if (IS_ERR(ptr: struct_meta_tab)) {
5550	err = PTR_ERR(ptr: struct_meta_tab);
5551	goto errout;
5552	}
5553	btf->struct_meta_tab = struct_meta_tab;
5554
5555	if (struct_meta_tab) {
5556	int i;
5557
5558	for (i = 0; i < struct_meta_tab->cnt; i++) {
5559	err = btf_check_and_fixup_fields(btf, rec: struct_meta_tab->types[i].record);
5560	if (err < 0)
5561	goto errout_meta;
5562	}
5563	}
5564
5565	err = finalize_log(log: &env->log, uattr, uattr_size);
5566	if (err)
5567	goto errout_free;
5568
5569	btf_verifier_env_free(env);
5570	refcount_set(r: &btf->refcnt, n: 1);
5571	return btf;
5572
5573	errout_meta:
5574	btf_free_struct_meta_tab(btf);
5575	errout:
5576	/* overwrite err with -ENOSPC or -EFAULT */
5577	ret = finalize_log(log: &env->log, uattr, uattr_size);
5578	if (ret)
5579	err = ret;
5580	errout_free:
5581	btf_verifier_env_free(env);
5582	if (btf)
5583	btf_free(btf);
5584	return ERR_PTR(error: err);
5585	}
5586
5587	extern char __weak __start_BTF[];
5588	extern char __weak __stop_BTF[];
5589	extern struct btf *btf_vmlinux;
5590
5591	#define BPF_MAP_TYPE(_id, _ops)
5592	#define BPF_LINK_TYPE(_id, _name)
5593	static union {
5594	struct bpf_ctx_convert {
5595	#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
5596	prog_ctx_type _id##_prog; \
5597	kern_ctx_type _id##_kern;
5598	#include <linux/bpf_types.h>
5599	#undef BPF_PROG_TYPE
5600	} *__t;
5601	/* 't' is written once under lock. Read many times. */
5602	const struct btf_type *t;
5603	} bpf_ctx_convert;
5604	enum {
5605	#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
5606	__ctx_convert##_id,
5607	#include <linux/bpf_types.h>
5608	#undef BPF_PROG_TYPE
5609	__ctx_convert_unused, /* to avoid empty enum in extreme .config */
5610	};
5611	static u8 bpf_ctx_convert_map[] = {
5612	#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
5613	[_id] = __ctx_convert##_id,
5614	#include <linux/bpf_types.h>
5615	#undef BPF_PROG_TYPE
5616	0, /* avoid empty array */
5617	};
5618	#undef BPF_MAP_TYPE
5619	#undef BPF_LINK_TYPE
5620
5621	const struct btf_member *
5622	btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
5623	const struct btf_type *t, enum bpf_prog_type prog_type,
5624	int arg)
5625	{
5626	const struct btf_type *conv_struct;
5627	const struct btf_type *ctx_struct;
5628	const struct btf_member *ctx_type;
5629	const char *tname, *ctx_tname;
5630
5631	conv_struct = bpf_ctx_convert.t;
5632	if (!conv_struct) {
5633	bpf_log(log, fmt: "btf_vmlinux is malformed\n");
5634	return NULL;
5635	}
5636	t = btf_type_by_id(btf, t->type);
5637	while (btf_type_is_modifier(t))
5638	t = btf_type_by_id(btf, t->type);
5639	if (!btf_type_is_struct(t)) {
5640	/* Only pointer to struct is supported for now.
5641	* That means that BPF_PROG_TYPE_TRACEPOINT with BTF
5642	* is not supported yet.
5643	* BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
5644	*/
5645	return NULL;
5646	}
5647	tname = btf_name_by_offset(btf, offset: t->name_off);
5648	if (!tname) {
5649	bpf_log(log, fmt: "arg#%d struct doesn't have a name\n", arg);
5650	return NULL;
5651	}
5652	/* prog_type is valid bpf program type. No need for bounds check. */
5653	ctx_type = btf_type_member(t: conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
5654	/* ctx_struct is a pointer to prog_ctx_type in vmlinux.
5655	* Like 'struct __sk_buff'
5656	*/
5657	ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
5658	if (!ctx_struct)
5659	/* should not happen */
5660	return NULL;
5661	again:
5662	ctx_tname = btf_name_by_offset(btf: btf_vmlinux, offset: ctx_struct->name_off);
5663	if (!ctx_tname) {
5664	/* should not happen */
5665	bpf_log(log, fmt: "Please fix kernel include/linux/bpf_types.h\n");
5666	return NULL;
5667	}
5668	/* only compare that prog's ctx type name is the same as
5669	* kernel expects. No need to compare field by field.
5670	* It's ok for bpf prog to do:
5671	* struct __sk_buff {};
5672	* int socket_filter_bpf_prog(struct __sk_buff *skb)
5673	* { // no fields of skb are ever used }
5674	*/
5675	if (strcmp(ctx_tname, "__sk_buff") == 0 && strcmp(tname, "sk_buff") == 0)
5676	return ctx_type;
5677	if (strcmp(ctx_tname, "xdp_md") == 0 && strcmp(tname, "xdp_buff") == 0)
5678	return ctx_type;
5679	if (strcmp(ctx_tname, tname)) {
5680	/* bpf_user_pt_regs_t is a typedef, so resolve it to
5681	* underlying struct and check name again
5682	*/
5683	if (!btf_type_is_modifier(t: ctx_struct))
5684	return NULL;
5685	while (btf_type_is_modifier(t: ctx_struct))
5686	ctx_struct = btf_type_by_id(btf_vmlinux, ctx_struct->type);
5687	goto again;
5688	}
5689	return ctx_type;
5690	}
5691
5692	static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
5693	struct btf *btf,
5694	const struct btf_type *t,
5695	enum bpf_prog_type prog_type,
5696	int arg)
5697	{
5698	const struct btf_member *prog_ctx_type, *kern_ctx_type;
5699
5700	prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type, arg);
5701	if (!prog_ctx_type)
5702	return -ENOENT;
5703	kern_ctx_type = prog_ctx_type + 1;
5704	return kern_ctx_type->type;
5705	}
5706
5707	int get_kern_ctx_btf_id(struct bpf_verifier_log *log, enum bpf_prog_type prog_type)
5708	{
5709	const struct btf_member *kctx_member;
5710	const struct btf_type *conv_struct;
5711	const struct btf_type *kctx_type;
5712	u32 kctx_type_id;
5713
5714	conv_struct = bpf_ctx_convert.t;
5715	/* get member for kernel ctx type */
5716	kctx_member = btf_type_member(t: conv_struct) + bpf_ctx_convert_map[prog_type] * 2 + 1;
5717	kctx_type_id = kctx_member->type;
5718	kctx_type = btf_type_by_id(btf_vmlinux, kctx_type_id);
5719	if (!btf_type_is_struct(t: kctx_type)) {
5720	bpf_log(log, fmt: "kern ctx type id %u is not a struct\n", kctx_type_id);
5721	return -EINVAL;
5722	}
5723
5724	return kctx_type_id;
5725	}
5726
5727	BTF_ID_LIST(bpf_ctx_convert_btf_id)
5728	BTF_ID(struct, bpf_ctx_convert)
5729
5730	struct btf *btf_parse_vmlinux(void)
5731	{
5732	struct btf_verifier_env *env = NULL;
5733	struct bpf_verifier_log *log;
5734	struct btf *btf = NULL;
5735	int err;
5736
5737	env = kzalloc(size: sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
5738	if (!env)
5739	return ERR_PTR(error: -ENOMEM);
5740
5741	log = &env->log;
5742	log->level = BPF_LOG_KERNEL;
5743
5744	btf = kzalloc(size: sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
5745	if (!btf) {
5746	err = -ENOMEM;
5747	goto errout;
5748	}
5749	env->btf = btf;
5750
5751	btf->data = __start_BTF;
5752	btf->data_size = __stop_BTF - __start_BTF;
5753	btf->kernel_btf = true;
5754	snprintf(buf: btf->name, size: sizeof(btf->name), fmt: "vmlinux");
5755
5756	err = btf_parse_hdr(env);
5757	if (err)
5758	goto errout;
5759
5760	btf->nohdr_data = btf->data + btf->hdr.hdr_len;
5761
5762	err = btf_parse_str_sec(env);
5763	if (err)
5764	goto errout;
5765
5766	err = btf_check_all_metas(env);
5767	if (err)
5768	goto errout;
5769
5770	err = btf_check_type_tags(env, btf, start_id: 1);
5771	if (err)
5772	goto errout;
5773
5774	/* btf_parse_vmlinux() runs under bpf_verifier_lock */
5775	bpf_ctx_convert.t = btf_type_by_id(btf, bpf_ctx_convert_btf_id[0]);
5776
5777	bpf_struct_ops_init(btf, log);
5778
5779	refcount_set(r: &btf->refcnt, n: 1);
5780
5781	err = btf_alloc_id(btf);
5782	if (err)
5783	goto errout;
5784
5785	btf_verifier_env_free(env);
5786	return btf;
5787
5788	errout:
5789	btf_verifier_env_free(env);
5790	if (btf) {
5791	kvfree(addr: btf->types);
5792	kfree(objp: btf);
5793	}
5794	return ERR_PTR(error: err);
5795	}
5796
5797	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
5798
5799	static struct btf *btf_parse_module(const char *module_name, const void *data, unsigned int data_size)
5800	{
5801	struct btf_verifier_env *env = NULL;
5802	struct bpf_verifier_log *log;
5803	struct btf *btf = NULL, *base_btf;
5804	int err;
5805
5806	base_btf = bpf_get_btf_vmlinux();
5807	if (IS_ERR(base_btf))
5808	return base_btf;
5809	if (!base_btf)
5810	return ERR_PTR(-EINVAL);
5811
5812	env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
5813	if (!env)
5814	return ERR_PTR(-ENOMEM);
5815
5816	log = &env->log;
5817	log->level = BPF_LOG_KERNEL;
5818
5819	btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
5820	if (!btf) {
5821	err = -ENOMEM;
5822	goto errout;
5823	}
5824	env->btf = btf;
5825
5826	btf->base_btf = base_btf;
5827	btf->start_id = base_btf->nr_types;
5828	btf->start_str_off = base_btf->hdr.str_len;
5829	btf->kernel_btf = true;
5830	snprintf(btf->name, sizeof(btf->name), "%s", module_name);
5831
5832	btf->data = kvmalloc(data_size, GFP_KERNEL | __GFP_NOWARN);
5833	if (!btf->data) {
5834	err = -ENOMEM;
5835	goto errout;
5836	}
5837	memcpy(btf->data, data, data_size);
5838	btf->data_size = data_size;
5839
5840	err = btf_parse_hdr(env);
5841	if (err)
5842	goto errout;
5843
5844	btf->nohdr_data = btf->data + btf->hdr.hdr_len;
5845
5846	err = btf_parse_str_sec(env);
5847	if (err)
5848	goto errout;
5849
5850	err = btf_check_all_metas(env);
5851	if (err)
5852	goto errout;
5853
5854	err = btf_check_type_tags(env, btf, btf_nr_types(base_btf));
5855	if (err)
5856	goto errout;
5857
5858	btf_verifier_env_free(env);
5859	refcount_set(&btf->refcnt, 1);
5860	return btf;
5861
5862	errout:
5863	btf_verifier_env_free(env);
5864	if (btf) {
5865	kvfree(btf->data);
5866	kvfree(btf->types);
5867	kfree(btf);
5868	}
5869	return ERR_PTR(err);
5870	}
5871
5872	#endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
5873
5874	struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
5875	{
5876	struct bpf_prog *tgt_prog = prog->aux->dst_prog;
5877
5878	if (tgt_prog)
5879	return tgt_prog->aux->btf;
5880	else
5881	return prog->aux->attach_btf;
5882	}
5883
5884	static bool is_int_ptr(struct btf *btf, const struct btf_type *t)
5885	{
5886	/* skip modifiers */
5887	t = btf_type_skip_modifiers(btf, id: t->type, NULL);
5888
5889	return btf_type_is_int(t);
5890	}
5891
5892	static u32 get_ctx_arg_idx(struct btf *btf, const struct btf_type *func_proto,
5893	int off)
5894	{
5895	const struct btf_param *args;
5896	const struct btf_type *t;
5897	u32 offset = 0, nr_args;
5898	int i;
5899
5900	if (!func_proto)
5901	return off / 8;
5902
5903	nr_args = btf_type_vlen(t: func_proto);
5904	args = (const struct btf_param *)(func_proto + 1);
5905	for (i = 0; i < nr_args; i++) {
5906	t = btf_type_skip_modifiers(btf, id: args[i].type, NULL);
5907	offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8);
5908	if (off < offset)
5909	return i;
5910	}
5911
5912	t = btf_type_skip_modifiers(btf, id: func_proto->type, NULL);
5913	offset += btf_type_is_ptr(t) ? 8 : roundup(t->size, 8);
5914	if (off < offset)
5915	return nr_args;
5916
5917	return nr_args + 1;
5918	}
5919
5920	static bool prog_args_trusted(const struct bpf_prog *prog)
5921	{
5922	enum bpf_attach_type atype = prog->expected_attach_type;
5923
5924	switch (prog->type) {
5925	case BPF_PROG_TYPE_TRACING:
5926	return atype == BPF_TRACE_RAW_TP || atype == BPF_TRACE_ITER;
5927	case BPF_PROG_TYPE_LSM:
5928	return bpf_lsm_is_trusted(prog);
5929	case BPF_PROG_TYPE_STRUCT_OPS:
5930	return true;
5931	default:
5932	return false;
5933	}
5934	}
5935
5936	bool btf_ctx_access(int off, int size, enum bpf_access_type type,
5937	const struct bpf_prog *prog,
5938	struct bpf_insn_access_aux *info)
5939	{
5940	const struct btf_type *t = prog->aux->attach_func_proto;
5941	struct bpf_prog *tgt_prog = prog->aux->dst_prog;
5942	struct btf *btf = bpf_prog_get_target_btf(prog);
5943	const char *tname = prog->aux->attach_func_name;
5944	struct bpf_verifier_log *log = info->log;
5945	const struct btf_param *args;
5946	const char *tag_value;
5947	u32 nr_args, arg;
5948	int i, ret;
5949
5950	if (off % 8) {
5951	bpf_log(log, fmt: "func '%s' offset %d is not multiple of 8\n",
5952	tname, off);
5953	return false;
5954	}
5955	arg = get_ctx_arg_idx(btf, func_proto: t, off);
5956	args = (const struct btf_param *)(t + 1);
5957	/* if (t == NULL) Fall back to default BPF prog with
5958	* MAX_BPF_FUNC_REG_ARGS u64 arguments.
5959	*/
5960	nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REG_ARGS;
5961	if (prog->aux->attach_btf_trace) {
5962	/* skip first 'void *__data' argument in btf_trace_##name typedef */
5963	args++;
5964	nr_args--;
5965	}
5966
5967	if (arg > nr_args) {
5968	bpf_log(log, fmt: "func '%s' doesn't have %d-th argument\n",
5969	tname, arg + 1);
5970	return false;
5971	}
5972
5973	if (arg == nr_args) {
5974	switch (prog->expected_attach_type) {
5975	case BPF_LSM_CGROUP:
5976	case BPF_LSM_MAC:
5977	case BPF_TRACE_FEXIT:
5978	/* When LSM programs are attached to void LSM hooks
5979	* they use FEXIT trampolines and when attached to
5980	* int LSM hooks, they use MODIFY_RETURN trampolines.
5981	*
5982	* While the LSM programs are BPF_MODIFY_RETURN-like
5983	* the check:
5984	*
5985	* if (ret_type != 'int')
5986	* return -EINVAL;
5987	*
5988	* is _not_ done here. This is still safe as LSM hooks
5989	* have only void and int return types.
5990	*/
5991	if (!t)
5992	return true;
5993	t = btf_type_by_id(btf, t->type);
5994	break;
5995	case BPF_MODIFY_RETURN:
5996	/* For now the BPF_MODIFY_RETURN can only be attached to
5997	* functions that return an int.
5998	*/
5999	if (!t)
6000	return false;
6001
6002	t = btf_type_skip_modifiers(btf, id: t->type, NULL);
6003	if (!btf_type_is_small_int(t)) {
6004	bpf_log(log,
6005	fmt: "ret type %s not allowed for fmod_ret\n",
6006	btf_type_str(t));
6007	return false;
6008	}
6009	break;
6010	default:
6011	bpf_log(log, fmt: "func '%s' doesn't have %d-th argument\n",
6012	tname, arg + 1);
6013	return false;
6014	}
6015	} else {
6016	if (!t)
6017	/* Default prog with MAX_BPF_FUNC_REG_ARGS args */
6018	return true;
6019	t = btf_type_by_id(btf, args[arg].type);
6020	}
6021
6022	/* skip modifiers */
6023	while (btf_type_is_modifier(t))
6024	t = btf_type_by_id(btf, t->type);
6025	if (btf_type_is_small_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t))
6026	/* accessing a scalar */
6027	return true;
6028	if (!btf_type_is_ptr(t)) {
6029	bpf_log(log,
6030	fmt: "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
6031	tname, arg,
6032	__btf_name_by_offset(btf, offset: t->name_off),
6033	btf_type_str(t));
6034	return false;
6035	}
6036
6037	/* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */
6038	for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
6039	const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
6040	u32 type, flag;
6041
6042	type = base_type(type: ctx_arg_info->reg_type);
6043	flag = type_flag(type: ctx_arg_info->reg_type);
6044	if (ctx_arg_info->offset == off && type == PTR_TO_BUF &&
6045	(flag & PTR_MAYBE_NULL)) {
6046	info->reg_type = ctx_arg_info->reg_type;
6047	return true;
6048	}
6049	}
6050
6051	if (t->type == 0)
6052	/* This is a pointer to void.
6053	* It is the same as scalar from the verifier safety pov.
6054	* No further pointer walking is allowed.
6055	*/
6056	return true;
6057
6058	if (is_int_ptr(btf, t))
6059	return true;
6060
6061	/* this is a pointer to another type */
6062	for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
6063	const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
6064
6065	if (ctx_arg_info->offset == off) {
6066	if (!ctx_arg_info->btf_id) {
6067	bpf_log(log,fmt: "invalid btf_id for context argument offset %u\n", off);
6068	return false;
6069	}
6070
6071	info->reg_type = ctx_arg_info->reg_type;
6072	info->btf = btf_vmlinux;
6073	info->btf_id = ctx_arg_info->btf_id;
6074	return true;
6075	}
6076	}
6077
6078	info->reg_type = PTR_TO_BTF_ID;
6079	if (prog_args_trusted(prog))
6080	info->reg_type |= PTR_TRUSTED;
6081
6082	if (tgt_prog) {
6083	enum bpf_prog_type tgt_type;
6084
6085	if (tgt_prog->type == BPF_PROG_TYPE_EXT)
6086	tgt_type = tgt_prog->aux->saved_dst_prog_type;
6087	else
6088	tgt_type = tgt_prog->type;
6089
6090	ret = btf_translate_to_vmlinux(log, btf, t, prog_type: tgt_type, arg);
6091	if (ret > 0) {
6092	info->btf = btf_vmlinux;
6093	info->btf_id = ret;
6094	return true;
6095	} else {
6096	return false;
6097	}
6098	}
6099
6100	info->btf = btf;
6101	info->btf_id = t->type;
6102	t = btf_type_by_id(btf, t->type);
6103
6104	if (btf_type_is_type_tag(t)) {
6105	tag_value = __btf_name_by_offset(btf, offset: t->name_off);
6106	if (strcmp(tag_value, "user") == 0)
6107	info->reg_type |= MEM_USER;
6108	if (strcmp(tag_value, "percpu") == 0)
6109	info->reg_type |= MEM_PERCPU;
6110	}
6111
6112	/* skip modifiers */
6113	while (btf_type_is_modifier(t)) {
6114	info->btf_id = t->type;
6115	t = btf_type_by_id(btf, t->type);
6116	}
6117	if (!btf_type_is_struct(t)) {
6118	bpf_log(log,
6119	fmt: "func '%s' arg%d type %s is not a struct\n",
6120	tname, arg, btf_type_str(t));
6121	return false;
6122	}
6123	bpf_log(log, fmt: "func '%s' arg%d has btf_id %d type %s '%s'\n",
6124	tname, arg, info->btf_id, btf_type_str(t),
6125	__btf_name_by_offset(btf, offset: t->name_off));
6126	return true;
6127	}
6128
6129	enum bpf_struct_walk_result {
6130	/* < 0 error */
6131	WALK_SCALAR = 0,
6132	WALK_PTR,
6133	WALK_STRUCT,
6134	};
6135
6136	static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf,
6137	const struct btf_type *t, int off, int size,
6138	u32 *next_btf_id, enum bpf_type_flag *flag,
6139	const char **field_name)
6140	{
6141	u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
6142	const struct btf_type *mtype, *elem_type = NULL;
6143	const struct btf_member *member;
6144	const char *tname, *mname, *tag_value;
6145	u32 vlen, elem_id, mid;
6146
6147	again:
6148	if (btf_type_is_modifier(t))
6149	t = btf_type_skip_modifiers(btf, id: t->type, NULL);
6150	tname = __btf_name_by_offset(btf, offset: t->name_off);
6151	if (!btf_type_is_struct(t)) {
6152	bpf_log(log, fmt: "Type '%s' is not a struct\n", tname);
6153	return -EINVAL;
6154	}
6155
6156	vlen = btf_type_vlen(t);
6157	if (BTF_INFO_KIND(t->info) == BTF_KIND_UNION && vlen != 1 && !(*flag & PTR_UNTRUSTED))
6158	/*
6159	* walking unions yields untrusted pointers
6160	* with exception of __bpf_md_ptr and other
6161	* unions with a single member
6162	*/
6163	*flag |= PTR_UNTRUSTED;
6164
6165	if (off + size > t->size) {
6166	/* If the last element is a variable size array, we may
6167	* need to relax the rule.
6168	*/
6169	struct btf_array *array_elem;
6170
6171	if (vlen == 0)
6172	goto error;
6173
6174	member = btf_type_member(t) + vlen - 1;
6175	mtype = btf_type_skip_modifiers(btf, id: member->type,
6176	NULL);
6177	if (!btf_type_is_array(t: mtype))
6178	goto error;
6179
6180	array_elem = (struct btf_array *)(mtype + 1);
6181	if (array_elem->nelems != 0)
6182	goto error;
6183
6184	moff = __btf_member_bit_offset(struct_type: t, member) / 8;
6185	if (off < moff)
6186	goto error;
6187
6188	/* allow structure and integer */
6189	t = btf_type_skip_modifiers(btf, id: array_elem->type,
6190	NULL);
6191
6192	if (btf_type_is_int(t))
6193	return WALK_SCALAR;
6194
6195	if (!btf_type_is_struct(t))
6196	goto error;
6197
6198	off = (off - moff) % t->size;
6199	goto again;
6200
6201	error:
6202	bpf_log(log, fmt: "access beyond struct %s at off %u size %u\n",
6203	tname, off, size);
6204	return -EACCES;
6205	}
6206
6207	for_each_member(i, t, member) {
6208	/* offset of the field in bytes */
6209	moff = __btf_member_bit_offset(struct_type: t, member) / 8;
6210	if (off + size <= moff)
6211	/* won't find anything, field is already too far */
6212	break;
6213
6214	if (__btf_member_bitfield_size(struct_type: t, member)) {
6215	u32 end_bit = __btf_member_bit_offset(struct_type: t, member) +
6216	__btf_member_bitfield_size(struct_type: t, member);
6217
6218	/* off <= moff instead of off == moff because clang
6219	* does not generate a BTF member for anonymous
6220	* bitfield like the ":16" here:
6221	* struct {
6222	* int :16;
6223	* int x:8;
6224	* };
6225	*/
6226	if (off <= moff &&
6227	BITS_ROUNDUP_BYTES(end_bit) <= off + size)
6228	return WALK_SCALAR;
6229
6230	/* off may be accessing a following member
6231	*
6232	* or
6233	*
6234	* Doing partial access at either end of this
6235	* bitfield. Continue on this case also to
6236	* treat it as not accessing this bitfield
6237	* and eventually error out as field not
6238	* found to keep it simple.
6239	* It could be relaxed if there was a legit
6240	* partial access case later.
6241	*/
6242	continue;
6243	}
6244
6245	/* In case of "off" is pointing to holes of a struct */
6246	if (off < moff)
6247	break;
6248
6249	/* type of the field */
6250	mid = member->type;
6251	mtype = btf_type_by_id(btf, member->type);
6252	mname = __btf_name_by_offset(btf, offset: member->name_off);
6253
6254	mtype = __btf_resolve_size(btf, type: mtype, type_size: &msize,
6255	elem_type: &elem_type, elem_id: &elem_id, total_nelems: &total_nelems,
6256	type_id: &mid);
6257	if (IS_ERR(ptr: mtype)) {
6258	bpf_log(log, fmt: "field %s doesn't have size\n", mname);
6259	return -EFAULT;
6260	}
6261
6262	mtrue_end = moff + msize;
6263	if (off >= mtrue_end)
6264	/* no overlap with member, keep iterating */
6265	continue;
6266
6267	if (btf_type_is_array(t: mtype)) {
6268	u32 elem_idx;
6269
6270	/* __btf_resolve_size() above helps to
6271	* linearize a multi-dimensional array.
6272	*
6273	* The logic here is treating an array
6274	* in a struct as the following way:
6275	*
6276	* struct outer {
6277	* struct inner array[2][2];
6278	* };
6279	*
6280	* looks like:
6281	*
6282	* struct outer {
6283	* struct inner array_elem0;
6284	* struct inner array_elem1;
6285	* struct inner array_elem2;
6286	* struct inner array_elem3;
6287	* };
6288	*
6289	* When accessing outer->array[1][0], it moves
6290	* moff to "array_elem2", set mtype to
6291	* "struct inner", and msize also becomes
6292	* sizeof(struct inner). Then most of the
6293	* remaining logic will fall through without
6294	* caring the current member is an array or
6295	* not.
6296	*
6297	* Unlike mtype/msize/moff, mtrue_end does not
6298	* change. The naming difference ("_true") tells
6299	* that it is not always corresponding to
6300	* the current mtype/msize/moff.
6301	* It is the true end of the current
6302	* member (i.e. array in this case). That
6303	* will allow an int array to be accessed like
6304	* a scratch space,
6305	* i.e. allow access beyond the size of
6306	* the array's element as long as it is
6307	* within the mtrue_end boundary.
6308	*/
6309
6310	/* skip empty array */
6311	if (moff == mtrue_end)
6312	continue;
6313
6314	msize /= total_nelems;
6315	elem_idx = (off - moff) / msize;
6316	moff += elem_idx * msize;
6317	mtype = elem_type;
6318	mid = elem_id;
6319	}
6320
6321	/* the 'off' we're looking for is either equal to start
6322	* of this field or inside of this struct
6323	*/
6324	if (btf_type_is_struct(t: mtype)) {
6325	/* our field must be inside that union or struct */
6326	t = mtype;
6327
6328	/* return if the offset matches the member offset */
6329	if (off == moff) {
6330	*next_btf_id = mid;
6331	return WALK_STRUCT;
6332	}
6333
6334	/* adjust offset we're looking for */
6335	off -= moff;
6336	goto again;
6337	}
6338
6339	if (btf_type_is_ptr(t: mtype)) {
6340	const struct btf_type *stype, *t;
6341	enum bpf_type_flag tmp_flag = 0;
6342	u32 id;
6343
6344	if (msize != size || off != moff) {
6345	bpf_log(log,
6346	fmt: "cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
6347	mname, moff, tname, off, size);
6348	return -EACCES;
6349	}
6350
6351	/* check type tag */
6352	t = btf_type_by_id(btf, mtype->type);
6353	if (btf_type_is_type_tag(t)) {
6354	tag_value = __btf_name_by_offset(btf, offset: t->name_off);
6355	/* check __user tag */
6356	if (strcmp(tag_value, "user") == 0)
6357	tmp_flag = MEM_USER;
6358	/* check __percpu tag */
6359	if (strcmp(tag_value, "percpu") == 0)
6360	tmp_flag = MEM_PERCPU;
6361	/* check __rcu tag */
6362	if (strcmp(tag_value, "rcu") == 0)
6363	tmp_flag = MEM_RCU;
6364	}
6365
6366	stype = btf_type_skip_modifiers(btf, id: mtype->type, res_id: &id);
6367	if (btf_type_is_struct(t: stype)) {
6368	*next_btf_id = id;
6369	*flag |= tmp_flag;
6370	if (field_name)
6371	*field_name = mname;
6372	return WALK_PTR;
6373	}
6374	}
6375
6376	/* Allow more flexible access within an int as long as
6377	* it is within mtrue_end.
6378	* Since mtrue_end could be the end of an array,
6379	* that also allows using an array of int as a scratch
6380	* space. e.g. skb->cb[].
6381	*/
6382	if (off + size > mtrue_end && !(*flag & PTR_UNTRUSTED)) {
6383	bpf_log(log,
6384	fmt: "access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
6385	mname, mtrue_end, tname, off, size);
6386	return -EACCES;
6387	}
6388
6389	return WALK_SCALAR;
6390	}
6391	bpf_log(log, fmt: "struct %s doesn't have field at offset %d\n", tname, off);
6392	return -EINVAL;
6393	}
6394
6395	int btf_struct_access(struct bpf_verifier_log *log,
6396	const struct bpf_reg_state *reg,
6397	int off, int size, enum bpf_access_type atype __maybe_unused,
6398	u32 *next_btf_id, enum bpf_type_flag *flag,
6399	const char **field_name)
6400	{
6401	const struct btf *btf = reg->btf;
6402	enum bpf_type_flag tmp_flag = 0;
6403	const struct btf_type *t;
6404	u32 id = reg->btf_id;
6405	int err;
6406
6407	while (type_is_alloc(type: reg->type)) {
6408	struct btf_struct_meta *meta;
6409	struct btf_record *rec;
6410	int i;
6411
6412	meta = btf_find_struct_meta(btf, btf_id: id);
6413	if (!meta)
6414	break;
6415	rec = meta->record;
6416	for (i = 0; i < rec->cnt; i++) {
6417	struct btf_field *field = &rec->fields[i];
6418	u32 offset = field->offset;
6419	if (off < offset + btf_field_type_size(type: field->type) && offset < off + size) {
6420	bpf_log(log,
6421	fmt: "direct access to %s is disallowed\n",
6422	btf_field_type_name(type: field->type));
6423	return -EACCES;
6424	}
6425	}
6426	break;
6427	}
6428
6429	t = btf_type_by_id(btf, id);
6430	do {
6431	err = btf_struct_walk(log, btf, t, off, size, next_btf_id: &id, flag: &tmp_flag, field_name);
6432
6433	switch (err) {
6434	case WALK_PTR:
6435	/* For local types, the destination register cannot
6436	* become a pointer again.
6437	*/
6438	if (type_is_alloc(type: reg->type))
6439	return SCALAR_VALUE;
6440	/* If we found the pointer or scalar on t+off,
6441	* we're done.
6442	*/
6443	*next_btf_id = id;
6444	*flag = tmp_flag;
6445	return PTR_TO_BTF_ID;
6446	case WALK_SCALAR:
6447	return SCALAR_VALUE;
6448	case WALK_STRUCT:
6449	/* We found nested struct, so continue the search
6450	* by diving in it. At this point the offset is
6451	* aligned with the new type, so set it to 0.
6452	*/
6453	t = btf_type_by_id(btf, id);
6454	off = 0;
6455	break;
6456	default:
6457	/* It's either error or unknown return value..
6458	* scream and leave.
6459	*/
6460	if (WARN_ONCE(err > 0, "unknown btf_struct_walk return value"))
6461	return -EINVAL;
6462	return err;
6463	}
6464	} while (t);
6465
6466	return -EINVAL;
6467	}
6468
6469	/* Check that two BTF types, each specified as an BTF object + id, are exactly
6470	* the same. Trivial ID check is not enough due to module BTFs, because we can
6471	* end up with two different module BTFs, but IDs point to the common type in
6472	* vmlinux BTF.
6473	*/
6474	bool btf_types_are_same(const struct btf *btf1, u32 id1,
6475	const struct btf *btf2, u32 id2)
6476	{
6477	if (id1 != id2)
6478	return false;
6479	if (btf1 == btf2)
6480	return true;
6481	return btf_type_by_id(btf1, id1) == btf_type_by_id(btf2, id2);
6482	}
6483
6484	bool btf_struct_ids_match(struct bpf_verifier_log *log,
6485	const struct btf *btf, u32 id, int off,
6486	const struct btf *need_btf, u32 need_type_id,
6487	bool strict)
6488	{
6489	const struct btf_type *type;
6490	enum bpf_type_flag flag = 0;
6491	int err;
6492
6493	/* Are we already done? */
6494	if (off == 0 && btf_types_are_same(btf1: btf, id1: id, btf2: need_btf, id2: need_type_id))
6495	return true;
6496	/* In case of strict type match, we do not walk struct, the top level
6497	* type match must succeed. When strict is true, off should have already
6498	* been 0.
6499	*/
6500	if (strict)
6501	return false;
6502	again:
6503	type = btf_type_by_id(btf, id);
6504	if (!type)
6505	return false;
6506	err = btf_struct_walk(log, btf, t: type, off, size: 1, next_btf_id: &id, flag: &flag, NULL);
6507	if (err != WALK_STRUCT)
6508	return false;
6509
6510	/* We found nested struct object. If it matches
6511	* the requested ID, we're done. Otherwise let's
6512	* continue the search with offset 0 in the new
6513	* type.
6514	*/
6515	if (!btf_types_are_same(btf1: btf, id1: id, btf2: need_btf, id2: need_type_id)) {
6516	off = 0;
6517	goto again;
6518	}
6519
6520	return true;
6521	}
6522
6523	static int __get_type_size(struct btf *btf, u32 btf_id,
6524	const struct btf_type **ret_type)
6525	{
6526	const struct btf_type *t;
6527
6528	*ret_type = btf_type_by_id(btf, 0);
6529	if (!btf_id)
6530	/* void */
6531	return 0;
6532	t = btf_type_by_id(btf, btf_id);
6533	while (t && btf_type_is_modifier(t))
6534	t = btf_type_by_id(btf, t->type);
6535	if (!t)
6536	return -EINVAL;
6537	*ret_type = t;
6538	if (btf_type_is_ptr(t))
6539	/* kernel size of pointer. Not BPF's size of pointer*/
6540	return sizeof(void *);
6541	if (btf_type_is_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t))
6542	return t->size;
6543	return -EINVAL;
6544	}
6545
6546	static u8 __get_type_fmodel_flags(const struct btf_type *t)
6547	{
6548	u8 flags = 0;
6549
6550	if (__btf_type_is_struct(t))
6551	flags |= BTF_FMODEL_STRUCT_ARG;
6552	if (btf_type_is_signed_int(t))
6553	flags |= BTF_FMODEL_SIGNED_ARG;
6554
6555	return flags;
6556	}
6557
6558	int btf_distill_func_proto(struct bpf_verifier_log *log,
6559	struct btf *btf,
6560	const struct btf_type *func,
6561	const char *tname,
6562	struct btf_func_model *m)
6563	{
6564	const struct btf_param *args;
6565	const struct btf_type *t;
6566	u32 i, nargs;
6567	int ret;
6568
6569	if (!func) {
6570	/* BTF function prototype doesn't match the verifier types.
6571	* Fall back to MAX_BPF_FUNC_REG_ARGS u64 args.
6572	*/
6573	for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) {
6574	m->arg_size[i] = 8;
6575	m->arg_flags[i] = 0;
6576	}
6577	m->ret_size = 8;
6578	m->ret_flags = 0;
6579	m->nr_args = MAX_BPF_FUNC_REG_ARGS;
6580	return 0;
6581	}
6582	args = (const struct btf_param *)(func + 1);
6583	nargs = btf_type_vlen(t: func);
6584	if (nargs > MAX_BPF_FUNC_ARGS) {
6585	bpf_log(log,
6586	fmt: "The function %s has %d arguments. Too many.\n",
6587	tname, nargs);
6588	return -EINVAL;
6589	}
6590	ret = __get_type_size(btf, btf_id: func->type, ret_type: &t);
6591	if (ret < 0 || __btf_type_is_struct(t)) {
6592	bpf_log(log,
6593	fmt: "The function %s return type %s is unsupported.\n",
6594	tname, btf_type_str(t));
6595	return -EINVAL;
6596	}
6597	m->ret_size = ret;
6598	m->ret_flags = __get_type_fmodel_flags(t);
6599
6600	for (i = 0; i < nargs; i++) {
6601	if (i == nargs - 1 && args[i].type == 0) {
6602	bpf_log(log,
6603	fmt: "The function %s with variable args is unsupported.\n",
6604	tname);
6605	return -EINVAL;
6606	}
6607	ret = __get_type_size(btf, btf_id: args[i].type, ret_type: &t);
6608
6609	/* No support of struct argument size greater than 16 bytes */
6610	if (ret < 0 || ret > 16) {
6611	bpf_log(log,
6612	fmt: "The function %s arg%d type %s is unsupported.\n",
6613	tname, i, btf_type_str(t));
6614	return -EINVAL;
6615	}
6616	if (ret == 0) {
6617	bpf_log(log,
6618	fmt: "The function %s has malformed void argument.\n",
6619	tname);
6620	return -EINVAL;
6621	}
6622	m->arg_size[i] = ret;
6623	m->arg_flags[i] = __get_type_fmodel_flags(t);
6624	}
6625	m->nr_args = nargs;
6626	return 0;
6627	}
6628
6629	/* Compare BTFs of two functions assuming only scalars and pointers to context.
6630	* t1 points to BTF_KIND_FUNC in btf1
6631	* t2 points to BTF_KIND_FUNC in btf2
6632	* Returns:
6633	* EINVAL - function prototype mismatch
6634	* EFAULT - verifier bug
6635	* 0 - 99% match. The last 1% is validated by the verifier.
6636	*/
6637	static int btf_check_func_type_match(struct bpf_verifier_log *log,
6638	struct btf *btf1, const struct btf_type *t1,
6639	struct btf *btf2, const struct btf_type *t2)
6640	{
6641	const struct btf_param *args1, *args2;
6642	const char *fn1, *fn2, *s1, *s2;
6643	u32 nargs1, nargs2, i;
6644
6645	fn1 = btf_name_by_offset(btf: btf1, offset: t1->name_off);
6646	fn2 = btf_name_by_offset(btf: btf2, offset: t2->name_off);
6647
6648	if (btf_func_linkage(t: t1) != BTF_FUNC_GLOBAL) {
6649	bpf_log(log, fmt: "%s() is not a global function\n", fn1);
6650	return -EINVAL;
6651	}
6652	if (btf_func_linkage(t: t2) != BTF_FUNC_GLOBAL) {
6653	bpf_log(log, fmt: "%s() is not a global function\n", fn2);
6654	return -EINVAL;
6655	}
6656
6657	t1 = btf_type_by_id(btf1, t1->type);
6658	if (!t1 || !btf_type_is_func_proto(t: t1))
6659	return -EFAULT;
6660	t2 = btf_type_by_id(btf2, t2->type);
6661	if (!t2 || !btf_type_is_func_proto(t: t2))
6662	return -EFAULT;
6663
6664	args1 = (const struct btf_param *)(t1 + 1);
6665	nargs1 = btf_type_vlen(t: t1);
6666	args2 = (const struct btf_param *)(t2 + 1);
6667	nargs2 = btf_type_vlen(t: t2);
6668
6669	if (nargs1 != nargs2) {
6670	bpf_log(log, fmt: "%s() has %d args while %s() has %d args\n",
6671	fn1, nargs1, fn2, nargs2);
6672	return -EINVAL;
6673	}
6674
6675	t1 = btf_type_skip_modifiers(btf: btf1, id: t1->type, NULL);
6676	t2 = btf_type_skip_modifiers(btf: btf2, id: t2->type, NULL);
6677	if (t1->info != t2->info) {
6678	bpf_log(log,
6679	fmt: "Return type %s of %s() doesn't match type %s of %s()\n",
6680	btf_type_str(t: t1), fn1,
6681	btf_type_str(t: t2), fn2);
6682	return -EINVAL;
6683	}
6684
6685	for (i = 0; i < nargs1; i++) {
6686	t1 = btf_type_skip_modifiers(btf: btf1, id: args1[i].type, NULL);
6687	t2 = btf_type_skip_modifiers(btf: btf2, id: args2[i].type, NULL);
6688
6689	if (t1->info != t2->info) {
6690	bpf_log(log, fmt: "arg%d in %s() is %s while %s() has %s\n",
6691	i, fn1, btf_type_str(t: t1),
6692	fn2, btf_type_str(t: t2));
6693	return -EINVAL;
6694	}
6695	if (btf_type_has_size(t: t1) && t1->size != t2->size) {
6696	bpf_log(log,
6697	fmt: "arg%d in %s() has size %d while %s() has %d\n",
6698	i, fn1, t1->size,
6699	fn2, t2->size);
6700	return -EINVAL;
6701	}
6702
6703	/* global functions are validated with scalars and pointers
6704	* to context only. And only global functions can be replaced.
6705	* Hence type check only those types.
6706	*/
6707	if (btf_type_is_int(t: t1) || btf_is_any_enum(t: t1))
6708	continue;
6709	if (!btf_type_is_ptr(t: t1)) {
6710	bpf_log(log,
6711	fmt: "arg%d in %s() has unrecognized type\n",
6712	i, fn1);
6713	return -EINVAL;
6714	}
6715	t1 = btf_type_skip_modifiers(btf: btf1, id: t1->type, NULL);
6716	t2 = btf_type_skip_modifiers(btf: btf2, id: t2->type, NULL);
6717	if (!btf_type_is_struct(t: t1)) {
6718	bpf_log(log,
6719	fmt: "arg%d in %s() is not a pointer to context\n",
6720	i, fn1);
6721	return -EINVAL;
6722	}
6723	if (!btf_type_is_struct(t: t2)) {
6724	bpf_log(log,
6725	fmt: "arg%d in %s() is not a pointer to context\n",
6726	i, fn2);
6727	return -EINVAL;
6728	}
6729	/* This is an optional check to make program writing easier.
6730	* Compare names of structs and report an error to the user.
6731	* btf_prepare_func_args() already checked that t2 struct
6732	* is a context type. btf_prepare_func_args() will check
6733	* later that t1 struct is a context type as well.
6734	*/
6735	s1 = btf_name_by_offset(btf: btf1, offset: t1->name_off);
6736	s2 = btf_name_by_offset(btf: btf2, offset: t2->name_off);
6737	if (strcmp(s1, s2)) {
6738	bpf_log(log,
6739	fmt: "arg%d %s(struct %s *) doesn't match %s(struct %s *)\n",
6740	i, fn1, s1, fn2, s2);
6741	return -EINVAL;
6742	}
6743	}
6744	return 0;
6745	}
6746
6747	/* Compare BTFs of given program with BTF of target program */
6748	int btf_check_type_match(struct bpf_verifier_log *log, const struct bpf_prog *prog,
6749	struct btf *btf2, const struct btf_type *t2)
6750	{
6751	struct btf *btf1 = prog->aux->btf;
6752	const struct btf_type *t1;
6753	u32 btf_id = 0;
6754
6755	if (!prog->aux->func_info) {
6756	bpf_log(log, fmt: "Program extension requires BTF\n");
6757	return -EINVAL;
6758	}
6759
6760	btf_id = prog->aux->func_info[0].type_id;
6761	if (!btf_id)
6762	return -EFAULT;
6763
6764	t1 = btf_type_by_id(btf1, btf_id);
6765	if (!t1 || !btf_type_is_func(t: t1))
6766	return -EFAULT;
6767
6768	return btf_check_func_type_match(log, btf1, t1, btf2, t2);
6769	}
6770
6771	static int btf_check_func_arg_match(struct bpf_verifier_env *env,
6772	const struct btf *btf, u32 func_id,
6773	struct bpf_reg_state *regs,
6774	bool ptr_to_mem_ok,
6775	bool processing_call)
6776	{
6777	enum bpf_prog_type prog_type = resolve_prog_type(prog: env->prog);
6778	struct bpf_verifier_log *log = &env->log;
6779	const char *func_name, *ref_tname;
6780	const struct btf_type *t, *ref_t;
6781	const struct btf_param *args;
6782	u32 i, nargs, ref_id;
6783	int ret;
6784
6785	t = btf_type_by_id(btf, func_id);
6786	if (!t || !btf_type_is_func(t)) {
6787	/* These checks were already done by the verifier while loading
6788	* struct bpf_func_info or in add_kfunc_call().
6789	*/
6790	bpf_log(log, fmt: "BTF of func_id %u doesn't point to KIND_FUNC\n",
6791	func_id);
6792	return -EFAULT;
6793	}
6794	func_name = btf_name_by_offset(btf, offset: t->name_off);
6795
6796	t = btf_type_by_id(btf, t->type);
6797	if (!t || !btf_type_is_func_proto(t)) {
6798	bpf_log(log, fmt: "Invalid BTF of func %s\n", func_name);
6799	return -EFAULT;
6800	}
6801	args = (const struct btf_param *)(t + 1);
6802	nargs = btf_type_vlen(t);
6803	if (nargs > MAX_BPF_FUNC_REG_ARGS) {
6804	bpf_log(log, fmt: "Function %s has %d > %d args\n", func_name, nargs,
6805	MAX_BPF_FUNC_REG_ARGS);
6806	return -EINVAL;
6807	}
6808
6809	/* check that BTF function arguments match actual types that the
6810	* verifier sees.
6811	*/
6812	for (i = 0; i < nargs; i++) {
6813	enum bpf_arg_type arg_type = ARG_DONTCARE;
6814	u32 regno = i + 1;
6815	struct bpf_reg_state *reg = &regs[regno];
6816
6817	t = btf_type_skip_modifiers(btf, id: args[i].type, NULL);
6818	if (btf_type_is_scalar(t)) {
6819	if (reg->type == SCALAR_VALUE)
6820	continue;
6821	bpf_log(log, fmt: "R%d is not a scalar\n", regno);
6822	return -EINVAL;
6823	}
6824
6825	if (!btf_type_is_ptr(t)) {
6826	bpf_log(log, fmt: "Unrecognized arg#%d type %s\n",
6827	i, btf_type_str(t));
6828	return -EINVAL;
6829	}
6830
6831	ref_t = btf_type_skip_modifiers(btf, id: t->type, res_id: &ref_id);
6832	ref_tname = btf_name_by_offset(btf, offset: ref_t->name_off);
6833
6834	ret = check_func_arg_reg_off(env, reg, regno, arg_type);
6835	if (ret < 0)
6836	return ret;
6837
6838	if (btf_get_prog_ctx_type(log, btf, t, prog_type, arg: i)) {
6839	/* If function expects ctx type in BTF check that caller
6840	* is passing PTR_TO_CTX.
6841	*/
6842	if (reg->type != PTR_TO_CTX) {
6843	bpf_log(log,
6844	fmt: "arg#%d expected pointer to ctx, but got %s\n",
6845	i, btf_type_str(t));
6846	return -EINVAL;
6847	}
6848	} else if (ptr_to_mem_ok && processing_call) {
6849	const struct btf_type *resolve_ret;
6850	u32 type_size;
6851
6852	resolve_ret = btf_resolve_size(btf, type: ref_t, type_size: &type_size);
6853	if (IS_ERR(ptr: resolve_ret)) {
6854	bpf_log(log,
6855	fmt: "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
6856	i, btf_type_str(t: ref_t), ref_tname,
6857	PTR_ERR(ptr: resolve_ret));
6858	return -EINVAL;
6859	}
6860
6861	if (check_mem_reg(env, reg, regno, mem_size: type_size))
6862	return -EINVAL;
6863	} else {
6864	bpf_log(log, fmt: "reg type unsupported for arg#%d function %s#%d\n", i,
6865	func_name, func_id);
6866	return -EINVAL;
6867	}
6868	}
6869
6870	return 0;
6871	}
6872
6873	/* Compare BTF of a function declaration with given bpf_reg_state.
6874	* Returns:
6875	* EFAULT - there is a verifier bug. Abort verification.
6876	* EINVAL - there is a type mismatch or BTF is not available.
6877	* 0 - BTF matches with what bpf_reg_state expects.
6878	* Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
6879	*/
6880	int btf_check_subprog_arg_match(struct bpf_verifier_env *env, int subprog,
6881	struct bpf_reg_state *regs)
6882	{
6883	struct bpf_prog *prog = env->prog;
6884	struct btf *btf = prog->aux->btf;
6885	bool is_global;
6886	u32 btf_id;
6887	int err;
6888
6889	if (!prog->aux->func_info)
6890	return -EINVAL;
6891
6892	btf_id = prog->aux->func_info[subprog].type_id;
6893	if (!btf_id)
6894	return -EFAULT;
6895
6896	if (prog->aux->func_info_aux[subprog].unreliable)
6897	return -EINVAL;
6898
6899	is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
6900	err = btf_check_func_arg_match(env, btf, func_id: btf_id, regs, ptr_to_mem_ok: is_global, processing_call: false);
6901
6902	/* Compiler optimizations can remove arguments from static functions
6903	* or mismatched type can be passed into a global function.
6904	* In such cases mark the function as unreliable from BTF point of view.
6905	*/
6906	if (err)
6907	prog->aux->func_info_aux[subprog].unreliable = true;
6908	return err;
6909	}
6910
6911	/* Compare BTF of a function call with given bpf_reg_state.
6912	* Returns:
6913	* EFAULT - there is a verifier bug. Abort verification.
6914	* EINVAL - there is a type mismatch or BTF is not available.
6915	* 0 - BTF matches with what bpf_reg_state expects.
6916	* Only PTR_TO_CTX and SCALAR_VALUE states are recognized.
6917	*
6918	* NOTE: the code is duplicated from btf_check_subprog_arg_match()
6919	* because btf_check_func_arg_match() is still doing both. Once that
6920	* function is split in 2, we can call from here btf_check_subprog_arg_match()
6921	* first, and then treat the calling part in a new code path.
6922	*/
6923	int btf_check_subprog_call(struct bpf_verifier_env *env, int subprog,
6924	struct bpf_reg_state *regs)
6925	{
6926	struct bpf_prog *prog = env->prog;
6927	struct btf *btf = prog->aux->btf;
6928	bool is_global;
6929	u32 btf_id;
6930	int err;
6931
6932	if (!prog->aux->func_info)
6933	return -EINVAL;
6934
6935	btf_id = prog->aux->func_info[subprog].type_id;
6936	if (!btf_id)
6937	return -EFAULT;
6938
6939	if (prog->aux->func_info_aux[subprog].unreliable)
6940	return -EINVAL;
6941
6942	is_global = prog->aux->func_info_aux[subprog].linkage == BTF_FUNC_GLOBAL;
6943	err = btf_check_func_arg_match(env, btf, func_id: btf_id, regs, ptr_to_mem_ok: is_global, processing_call: true);
6944
6945	/* Compiler optimizations can remove arguments from static functions
6946	* or mismatched type can be passed into a global function.
6947	* In such cases mark the function as unreliable from BTF point of view.
6948	*/
6949	if (err)
6950	prog->aux->func_info_aux[subprog].unreliable = true;
6951	return err;
6952	}
6953
6954	/* Convert BTF of a function into bpf_reg_state if possible
6955	* Returns:
6956	* EFAULT - there is a verifier bug. Abort verification.
6957	* EINVAL - cannot convert BTF.
6958	* 0 - Successfully converted BTF into bpf_reg_state
6959	* (either PTR_TO_CTX or SCALAR_VALUE).
6960	*/
6961	int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
6962	struct bpf_reg_state *regs, bool is_ex_cb)
6963	{
6964	struct bpf_verifier_log *log = &env->log;
6965	struct bpf_prog *prog = env->prog;
6966	enum bpf_prog_type prog_type = prog->type;
6967	struct btf *btf = prog->aux->btf;
6968	const struct btf_param *args;
6969	const struct btf_type *t, *ref_t;
6970	u32 i, nargs, btf_id;
6971	const char *tname;
6972
6973	if (!prog->aux->func_info ||
6974	prog->aux->func_info_aux[subprog].linkage != BTF_FUNC_GLOBAL) {
6975	bpf_log(log, fmt: "Verifier bug\n");
6976	return -EFAULT;
6977	}
6978
6979	btf_id = prog->aux->func_info[subprog].type_id;
6980	if (!btf_id) {
6981	bpf_log(log, fmt: "Global functions need valid BTF\n");
6982	return -EFAULT;
6983	}
6984
6985	t = btf_type_by_id(btf, btf_id);
6986	if (!t || !btf_type_is_func(t)) {
6987	/* These checks were already done by the verifier while loading
6988	* struct bpf_func_info
6989	*/
6990	bpf_log(log, fmt: "BTF of func#%d doesn't point to KIND_FUNC\n",
6991	subprog);
6992	return -EFAULT;
6993	}
6994	tname = btf_name_by_offset(btf, offset: t->name_off);
6995
6996	if (log->level & BPF_LOG_LEVEL)
6997	bpf_log(log, fmt: "Validating %s() func#%d...\n",
6998	tname, subprog);
6999
7000	if (prog->aux->func_info_aux[subprog].unreliable) {
7001	bpf_log(log, fmt: "Verifier bug in function %s()\n", tname);
7002	return -EFAULT;
7003	}
7004	if (prog_type == BPF_PROG_TYPE_EXT)
7005	prog_type = prog->aux->dst_prog->type;
7006
7007	t = btf_type_by_id(btf, t->type);
7008	if (!t || !btf_type_is_func_proto(t)) {
7009	bpf_log(log, fmt: "Invalid type of function %s()\n", tname);
7010	return -EFAULT;
7011	}
7012	args = (const struct btf_param *)(t + 1);
7013	nargs = btf_type_vlen(t);
7014	if (nargs > MAX_BPF_FUNC_REG_ARGS) {
7015	bpf_log(log, fmt: "Global function %s() with %d > %d args. Buggy compiler.\n",
7016	tname, nargs, MAX_BPF_FUNC_REG_ARGS);
7017	return -EINVAL;
7018	}
7019	/* check that function returns int, exception cb also requires this */
7020	t = btf_type_by_id(btf, t->type);
7021	while (btf_type_is_modifier(t))
7022	t = btf_type_by_id(btf, t->type);
7023	if (!btf_type_is_int(t) && !btf_is_any_enum(t)) {
7024	bpf_log(log,
7025	fmt: "Global function %s() doesn't return scalar. Only those are supported.\n",
7026	tname);
7027	return -EINVAL;
7028	}
7029	/* Convert BTF function arguments into verifier types.
7030	* Only PTR_TO_CTX and SCALAR are supported atm.
7031	*/
7032	for (i = 0; i < nargs; i++) {
7033	struct bpf_reg_state *reg = &regs[i + 1];
7034
7035	t = btf_type_by_id(btf, args[i].type);
7036	while (btf_type_is_modifier(t))
7037	t = btf_type_by_id(btf, t->type);
7038	if (btf_type_is_int(t) || btf_is_any_enum(t)) {
7039	reg->type = SCALAR_VALUE;
7040	continue;
7041	}
7042	if (btf_type_is_ptr(t)) {
7043	if (btf_get_prog_ctx_type(log, btf, t, prog_type, arg: i)) {
7044	reg->type = PTR_TO_CTX;
7045	continue;
7046	}
7047
7048	t = btf_type_skip_modifiers(btf, id: t->type, NULL);
7049
7050	ref_t = btf_resolve_size(btf, type: t, type_size: &reg->mem_size);
7051	if (IS_ERR(ptr: ref_t)) {
7052	bpf_log(log,
7053	fmt: "arg#%d reference type('%s %s') size cannot be determined: %ld\n",
7054	i, btf_type_str(t), btf_name_by_offset(btf, offset: t->name_off),
7055	PTR_ERR(ptr: ref_t));
7056	return -EINVAL;
7057	}
7058
7059	reg->type = PTR_TO_MEM | PTR_MAYBE_NULL;
7060	reg->id = ++env->id_gen;
7061
7062	continue;
7063	}
7064	bpf_log(log, fmt: "Arg#%d type %s in %s() is not supported yet.\n",
7065	i, btf_type_str(t), tname);
7066	return -EINVAL;
7067	}
7068	/* We have already ensured that the callback returns an integer, just
7069	* like all global subprogs. We need to determine it only has a single
7070	* scalar argument.
7071	*/
7072	if (is_ex_cb && (nargs != 1 || regs[BPF_REG_1].type != SCALAR_VALUE)) {
7073	bpf_log(log, fmt: "exception cb only supports single integer argument\n");
7074	return -EINVAL;
7075	}
7076	return 0;
7077	}
7078
7079	static void btf_type_show(const struct btf *btf, u32 type_id, void *obj,
7080	struct btf_show *show)
7081	{
7082	const struct btf_type *t = btf_type_by_id(btf, type_id);
7083
7084	show->btf = btf;
7085	memset(&show->state, 0, sizeof(show->state));
7086	memset(&show->obj, 0, sizeof(show->obj));
7087
7088	btf_type_ops(t)->show(btf, t, type_id, obj, 0, show);
7089	}
7090
7091	static void btf_seq_show(struct btf_show *show, const char *fmt,
7092	va_list args)
7093	{
7094	seq_vprintf(m: (struct seq_file *)show->target, fmt, args);
7095	}
7096
7097	int btf_type_seq_show_flags(const struct btf *btf, u32 type_id,
7098	void *obj, struct seq_file *m, u64 flags)
7099	{
7100	struct btf_show sseq;
7101
7102	sseq.target = m;
7103	sseq.showfn = btf_seq_show;
7104	sseq.flags = flags;
7105
7106	btf_type_show(btf, type_id, obj, show: &sseq);
7107
7108	return sseq.state.status;
7109	}
7110
7111	void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
7112	struct seq_file *m)
7113	{
7114	(void) btf_type_seq_show_flags(btf, type_id, obj, m,
7115	BTF_SHOW_NONAME | BTF_SHOW_COMPACT |
7116	BTF_SHOW_ZERO | BTF_SHOW_UNSAFE);
7117	}
7118
7119	struct btf_show_snprintf {
7120	struct btf_show show;
7121	int len_left; /* space left in string */
7122	int len; /* length we would have written */
7123	};
7124
7125	static void btf_snprintf_show(struct btf_show *show, const char *fmt,
7126	va_list args)
7127	{
7128	struct btf_show_snprintf *ssnprintf = (struct btf_show_snprintf *)show;
7129	int len;
7130
7131	len = vsnprintf(buf: show->target, size: ssnprintf->len_left, fmt, args);
7132
7133	if (len < 0) {
7134	ssnprintf->len_left = 0;
7135	ssnprintf->len = len;
7136	} else if (len >= ssnprintf->len_left) {
7137	/* no space, drive on to get length we would have written */
7138	ssnprintf->len_left = 0;
7139	ssnprintf->len += len;
7140	} else {
7141	ssnprintf->len_left -= len;
7142	ssnprintf->len += len;
7143	show->target += len;
7144	}
7145	}
7146
7147	int btf_type_snprintf_show(const struct btf *btf, u32 type_id, void *obj,
7148	char *buf, int len, u64 flags)
7149	{
7150	struct btf_show_snprintf ssnprintf;
7151
7152	ssnprintf.show.target = buf;
7153	ssnprintf.show.flags = flags;
7154	ssnprintf.show.showfn = btf_snprintf_show;
7155	ssnprintf.len_left = len;
7156	ssnprintf.len = 0;
7157
7158	btf_type_show(btf, type_id, obj, show: (struct btf_show *)&ssnprintf);
7159
7160	/* If we encountered an error, return it. */
7161	if (ssnprintf.show.state.status)
7162	return ssnprintf.show.state.status;
7163
7164	/* Otherwise return length we would have written */
7165	return ssnprintf.len;
7166	}
7167
7168	#ifdef CONFIG_PROC_FS
7169	static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp)
7170	{
7171	const struct btf *btf = filp->private_data;
7172
7173	seq_printf(m, fmt: "btf_id:\t%u\n", btf->id);
7174	}
7175	#endif
7176
7177	static int btf_release(struct inode *inode, struct file *filp)
7178	{
7179	btf_put(btf: filp->private_data);
7180	return 0;
7181	}
7182
7183	const struct file_operations btf_fops = {
7184	#ifdef CONFIG_PROC_FS
7185	.show_fdinfo = bpf_btf_show_fdinfo,
7186	#endif
7187	.release = btf_release,
7188	};
7189
7190	static int __btf_new_fd(struct btf *btf)
7191	{
7192	return anon_inode_getfd(name: "btf", fops: &btf_fops, priv: btf, O_RDONLY | O_CLOEXEC);
7193	}
7194
7195	int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
7196	{
7197	struct btf *btf;
7198	int ret;
7199
7200	btf = btf_parse(attr, uattr, uattr_size);
7201	if (IS_ERR(ptr: btf))
7202	return PTR_ERR(ptr: btf);
7203
7204	ret = btf_alloc_id(btf);
7205	if (ret) {
7206	btf_free(btf);
7207	return ret;
7208	}
7209
7210	/*
7211	* The BTF ID is published to the userspace.
7212	* All BTF free must go through call_rcu() from
7213	* now on (i.e. free by calling btf_put()).
7214	*/
7215
7216	ret = __btf_new_fd(btf);
7217	if (ret < 0)
7218	btf_put(btf);
7219
7220	return ret;
7221	}
7222
7223	struct btf *btf_get_by_fd(int fd)
7224	{
7225	struct btf *btf;
7226	struct fd f;
7227
7228	f = fdget(fd);
7229
7230	if (!f.file)
7231	return ERR_PTR(error: -EBADF);
7232
7233	if (f.file->f_op != &btf_fops) {
7234	fdput(fd: f);
7235	return ERR_PTR(error: -EINVAL);
7236	}
7237
7238	btf = f.file->private_data;
7239	refcount_inc(r: &btf->refcnt);
7240	fdput(fd: f);
7241
7242	return btf;
7243	}
7244
7245	int btf_get_info_by_fd(const struct btf *btf,
7246	const union bpf_attr *attr,
7247	union bpf_attr __user *uattr)
7248	{
7249	struct bpf_btf_info __user *uinfo;
7250	struct bpf_btf_info info;
7251	u32 info_copy, btf_copy;
7252	void __user *ubtf;
7253	char __user *uname;
7254	u32 uinfo_len, uname_len, name_len;
7255	int ret = 0;
7256
7257	uinfo = u64_to_user_ptr(attr->info.info);
7258	uinfo_len = attr->info.info_len;
7259
7260	info_copy = min_t(u32, uinfo_len, sizeof(info));
7261	memset(&info, 0, sizeof(info));
7262	if (copy_from_user(to: &info, from: uinfo, n: info_copy))
7263	return -EFAULT;
7264
7265	info.id = btf->id;
7266	ubtf = u64_to_user_ptr(info.btf);
7267	btf_copy = min_t(u32, btf->data_size, info.btf_size);
7268	if (copy_to_user(to: ubtf, from: btf->data, n: btf_copy))
7269	return -EFAULT;
7270	info.btf_size = btf->data_size;
7271
7272	info.kernel_btf = btf->kernel_btf;
7273
7274	uname = u64_to_user_ptr(info.name);
7275	uname_len = info.name_len;
7276	if (!uname ^ !uname_len)
7277	return -EINVAL;
7278
7279	name_len = strlen(btf->name);
7280	info.name_len = name_len;
7281
7282	if (uname) {
7283	if (uname_len >= name_len + 1) {
7284	if (copy_to_user(to: uname, from: btf->name, n: name_len + 1))
7285	return -EFAULT;
7286	} else {
7287	char zero = '\0';
7288
7289	if (copy_to_user(to: uname, from: btf->name, n: uname_len - 1))
7290	return -EFAULT;
7291	if (put_user(zero, uname + uname_len - 1))
7292	return -EFAULT;
7293	/* let user-space know about too short buffer */
7294	ret = -ENOSPC;
7295	}
7296	}
7297
7298	if (copy_to_user(to: uinfo, from: &info, n: info_copy) ||
7299	put_user(info_copy, &uattr->info.info_len))
7300	return -EFAULT;
7301
7302	return ret;
7303	}
7304
7305	int btf_get_fd_by_id(u32 id)
7306	{
7307	struct btf *btf;
7308	int fd;
7309
7310	rcu_read_lock();
7311	btf = idr_find(&btf_idr, id);
7312	if (!btf || !refcount_inc_not_zero(r: &btf->refcnt))
7313	btf = ERR_PTR(error: -ENOENT);
7314	rcu_read_unlock();
7315
7316	if (IS_ERR(ptr: btf))
7317	return PTR_ERR(ptr: btf);
7318
7319	fd = __btf_new_fd(btf);
7320	if (fd < 0)
7321	btf_put(btf);
7322
7323	return fd;
7324	}
7325
7326	u32 btf_obj_id(const struct btf *btf)
7327	{
7328	return btf->id;
7329	}
7330
7331	bool btf_is_kernel(const struct btf *btf)
7332	{
7333	return btf->kernel_btf;
7334	}
7335
7336	bool btf_is_module(const struct btf *btf)
7337	{
7338	return btf->kernel_btf && strcmp(btf->name, "vmlinux") != 0;
7339	}
7340
7341	enum {
7342	BTF_MODULE_F_LIVE = (1 << 0),
7343	};
7344
7345	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
7346	struct btf_module {
7347	struct list_head list;
7348	struct module *module;
7349	struct btf *btf;
7350	struct bin_attribute *sysfs_attr;
7351	int flags;
7352	};
7353
7354	static LIST_HEAD(btf_modules);
7355	static DEFINE_MUTEX(btf_module_mutex);
7356
7357	static ssize_t
7358	btf_module_read(struct file *file, struct kobject *kobj,
7359	struct bin_attribute *bin_attr,
7360	char *buf, loff_t off, size_t len)
7361	{
7362	const struct btf *btf = bin_attr->private;
7363
7364	memcpy(buf, btf->data + off, len);
7365	return len;
7366	}
7367
7368	static void purge_cand_cache(struct btf *btf);
7369
7370	static int btf_module_notify(struct notifier_block *nb, unsigned long op,
7371	void *module)
7372	{
7373	struct btf_module *btf_mod, *tmp;
7374	struct module *mod = module;
7375	struct btf *btf;
7376	int err = 0;
7377
7378	if (mod->btf_data_size == 0 ||
7379	(op != MODULE_STATE_COMING && op != MODULE_STATE_LIVE &&
7380	op != MODULE_STATE_GOING))
7381	goto out;
7382
7383	switch (op) {
7384	case MODULE_STATE_COMING:
7385	btf_mod = kzalloc(sizeof(*btf_mod), GFP_KERNEL);
7386	if (!btf_mod) {
7387	err = -ENOMEM;
7388	goto out;
7389	}
7390	btf = btf_parse_module(mod->name, mod->btf_data, mod->btf_data_size);
7391	if (IS_ERR(btf)) {
7392	kfree(btf_mod);
7393	if (!IS_ENABLED(CONFIG_MODULE_ALLOW_BTF_MISMATCH)) {
7394	pr_warn("failed to validate module [%s] BTF: %ld\n",
7395	mod->name, PTR_ERR(btf));
7396	err = PTR_ERR(btf);
7397	} else {
7398	pr_warn_once("Kernel module BTF mismatch detected, BTF debug info may be unavailable for some modules\n");
7399	}
7400	goto out;
7401	}
7402	err = btf_alloc_id(btf);
7403	if (err) {
7404	btf_free(btf);
7405	kfree(btf_mod);
7406	goto out;
7407	}
7408
7409	purge_cand_cache(NULL);
7410	mutex_lock(&btf_module_mutex);
7411	btf_mod->module = module;
7412	btf_mod->btf = btf;
7413	list_add(&btf_mod->list, &btf_modules);
7414	mutex_unlock(&btf_module_mutex);
7415
7416	if (IS_ENABLED(CONFIG_SYSFS)) {
7417	struct bin_attribute *attr;
7418
7419	attr = kzalloc(sizeof(*attr), GFP_KERNEL);
7420	if (!attr)
7421	goto out;
7422
7423	sysfs_bin_attr_init(attr);
7424	attr->attr.name = btf->name;
7425	attr->attr.mode = 0444;
7426	attr->size = btf->data_size;
7427	attr->private = btf;
7428	attr->read = btf_module_read;
7429
7430	err = sysfs_create_bin_file(btf_kobj, attr);
7431	if (err) {
7432	pr_warn("failed to register module [%s] BTF in sysfs: %d\n",
7433	mod->name, err);
7434	kfree(attr);
7435	err = 0;
7436	goto out;
7437	}
7438
7439	btf_mod->sysfs_attr = attr;
7440	}
7441
7442	break;
7443	case MODULE_STATE_LIVE:
7444	mutex_lock(&btf_module_mutex);
7445	list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
7446	if (btf_mod->module != module)
7447	continue;
7448
7449	btf_mod->flags |= BTF_MODULE_F_LIVE;
7450	break;
7451	}
7452	mutex_unlock(&btf_module_mutex);
7453	break;
7454	case MODULE_STATE_GOING:
7455	mutex_lock(&btf_module_mutex);
7456	list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
7457	if (btf_mod->module != module)
7458	continue;
7459
7460	list_del(&btf_mod->list);
7461	if (btf_mod->sysfs_attr)
7462	sysfs_remove_bin_file(btf_kobj, btf_mod->sysfs_attr);
7463	purge_cand_cache(btf_mod->btf);
7464	btf_put(btf_mod->btf);
7465	kfree(btf_mod->sysfs_attr);
7466	kfree(btf_mod);
7467	break;
7468	}
7469	mutex_unlock(&btf_module_mutex);
7470	break;
7471	}
7472	out:
7473	return notifier_from_errno(err);
7474	}
7475
7476	static struct notifier_block btf_module_nb = {
7477	.notifier_call = btf_module_notify,
7478	};
7479
7480	static int __init btf_module_init(void)
7481	{
7482	register_module_notifier(&btf_module_nb);
7483	return 0;
7484	}
7485
7486	fs_initcall(btf_module_init);
7487	#endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
7488
7489	struct module *btf_try_get_module(const struct btf *btf)
7490	{
7491	struct module *res = NULL;
7492	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
7493	struct btf_module *btf_mod, *tmp;
7494
7495	mutex_lock(&btf_module_mutex);
7496	list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
7497	if (btf_mod->btf != btf)
7498	continue;
7499
7500	/* We must only consider module whose __init routine has
7501	* finished, hence we must check for BTF_MODULE_F_LIVE flag,
7502	* which is set from the notifier callback for
7503	* MODULE_STATE_LIVE.
7504	*/
7505	if ((btf_mod->flags & BTF_MODULE_F_LIVE) && try_module_get(btf_mod->module))
7506	res = btf_mod->module;
7507
7508	break;
7509	}
7510	mutex_unlock(&btf_module_mutex);
7511	#endif
7512
7513	return res;
7514	}
7515
7516	/* Returns struct btf corresponding to the struct module.
7517	* This function can return NULL or ERR_PTR.
7518	*/
7519	static struct btf *btf_get_module_btf(const struct module *module)
7520	{
7521	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
7522	struct btf_module *btf_mod, *tmp;
7523	#endif
7524	struct btf *btf = NULL;
7525
7526	if (!module) {
7527	btf = bpf_get_btf_vmlinux();
7528	if (!IS_ERR_OR_NULL(ptr: btf))
7529	btf_get(btf);
7530	return btf;
7531	}
7532
7533	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
7534	mutex_lock(&btf_module_mutex);
7535	list_for_each_entry_safe(btf_mod, tmp, &btf_modules, list) {
7536	if (btf_mod->module != module)
7537	continue;
7538
7539	btf_get(btf_mod->btf);
7540	btf = btf_mod->btf;
7541	break;
7542	}
7543	mutex_unlock(&btf_module_mutex);
7544	#endif
7545
7546	return btf;
7547	}
7548
7549	BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags)
7550	{
7551	struct btf *btf = NULL;
7552	int btf_obj_fd = 0;
7553	long ret;
7554
7555	if (flags)
7556	return -EINVAL;
7557
7558	if (name_sz <= 1 || name[name_sz - 1])
7559	return -EINVAL;
7560
7561	ret = bpf_find_btf_id(name, kind, btf_p: &btf);
7562	if (ret > 0 && btf_is_module(btf)) {
7563	btf_obj_fd = __btf_new_fd(btf);
7564	if (btf_obj_fd < 0) {
7565	btf_put(btf);
7566	return btf_obj_fd;
7567	}
7568	return ret | (((u64)btf_obj_fd) << 32);
7569	}
7570	if (ret > 0)
7571	btf_put(btf);
7572	return ret;
7573	}
7574
7575	const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = {
7576	.func = bpf_btf_find_by_name_kind,
7577	.gpl_only = false,
7578	.ret_type = RET_INTEGER,
7579	.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
7580	.arg2_type = ARG_CONST_SIZE,
7581	.arg3_type = ARG_ANYTHING,
7582	.arg4_type = ARG_ANYTHING,
7583	};
7584
7585	BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE)
7586	#define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type)
7587	BTF_TRACING_TYPE_xxx
7588	#undef BTF_TRACING_TYPE
7589
7590	static int btf_check_iter_kfuncs(struct btf *btf, const char *func_name,
7591	const struct btf_type *func, u32 func_flags)
7592	{
7593	u32 flags = func_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY);
7594	const char *name, *sfx, *iter_name;
7595	const struct btf_param *arg;
7596	const struct btf_type *t;
7597	char exp_name[128];
7598	u32 nr_args;
7599
7600	/* exactly one of KF_ITER_{NEW,NEXT,DESTROY} can be set */
7601	if (!flags || (flags & (flags - 1)))
7602	return -EINVAL;
7603
7604	/* any BPF iter kfunc should have `struct bpf_iter_<type> *` first arg */
7605	nr_args = btf_type_vlen(t: func);
7606	if (nr_args < 1)
7607	return -EINVAL;
7608
7609	arg = &btf_params(t: func)[0];
7610	t = btf_type_skip_modifiers(btf, id: arg->type, NULL);
7611	if (!t || !btf_type_is_ptr(t))
7612	return -EINVAL;
7613	t = btf_type_skip_modifiers(btf, id: t->type, NULL);
7614	if (!t || !__btf_type_is_struct(t))
7615	return -EINVAL;
7616
7617	name = btf_name_by_offset(btf, offset: t->name_off);
7618	if (!name || strncmp(name, ITER_PREFIX, sizeof(ITER_PREFIX) - 1))
7619	return -EINVAL;
7620
7621	/* sizeof(struct bpf_iter_<type>) should be a multiple of 8 to
7622	* fit nicely in stack slots
7623	*/
7624	if (t->size == 0 || (t->size % 8))
7625	return -EINVAL;
7626
7627	/* validate bpf_iter_<type>_{new,next,destroy}(struct bpf_iter_<type> *)
7628	* naming pattern
7629	*/
7630	iter_name = name + sizeof(ITER_PREFIX) - 1;
7631	if (flags & KF_ITER_NEW)
7632	sfx = "new";
7633	else if (flags & KF_ITER_NEXT)
7634	sfx = "next";
7635	else /* (flags & KF_ITER_DESTROY) */
7636	sfx = "destroy";
7637
7638	snprintf(buf: exp_name, size: sizeof(exp_name), fmt: "bpf_iter_%s_%s", iter_name, sfx);
7639	if (strcmp(func_name, exp_name))
7640	return -EINVAL;
7641
7642	/* only iter constructor should have extra arguments */
7643	if (!(flags & KF_ITER_NEW) && nr_args != 1)
7644	return -EINVAL;
7645
7646	if (flags & KF_ITER_NEXT) {
7647	/* bpf_iter_<type>_next() should return pointer */
7648	t = btf_type_skip_modifiers(btf, id: func->type, NULL);
7649	if (!t || !btf_type_is_ptr(t))
7650	return -EINVAL;
7651	}
7652
7653	if (flags & KF_ITER_DESTROY) {
7654	/* bpf_iter_<type>_destroy() should return void */
7655	t = btf_type_by_id(btf, func->type);
7656	if (!t || !btf_type_is_void(t))
7657	return -EINVAL;
7658	}
7659
7660	return 0;
7661	}
7662
7663	static int btf_check_kfunc_protos(struct btf *btf, u32 func_id, u32 func_flags)
7664	{
7665	const struct btf_type *func;
7666	const char *func_name;
7667	int err;
7668
7669	/* any kfunc should be FUNC -> FUNC_PROTO */
7670	func = btf_type_by_id(btf, func_id);
7671	if (!func || !btf_type_is_func(t: func))
7672	return -EINVAL;
7673
7674	/* sanity check kfunc name */
7675	func_name = btf_name_by_offset(btf, offset: func->name_off);
7676	if (!func_name || !func_name[0])
7677	return -EINVAL;
7678
7679	func = btf_type_by_id(btf, func->type);
7680	if (!func || !btf_type_is_func_proto(t: func))
7681	return -EINVAL;
7682
7683	if (func_flags & (KF_ITER_NEW | KF_ITER_NEXT | KF_ITER_DESTROY)) {
7684	err = btf_check_iter_kfuncs(btf, func_name, func, func_flags);
7685	if (err)
7686	return err;
7687	}
7688
7689	return 0;
7690	}
7691
7692	/* Kernel Function (kfunc) BTF ID set registration API */
7693
7694	static int btf_populate_kfunc_set(struct btf *btf, enum btf_kfunc_hook hook,
7695	const struct btf_kfunc_id_set *kset)
7696	{
7697	struct btf_kfunc_hook_filter *hook_filter;
7698	struct btf_id_set8 *add_set = kset->set;
7699	bool vmlinux_set = !btf_is_module(btf);
7700	bool add_filter = !!kset->filter;
7701	struct btf_kfunc_set_tab *tab;
7702	struct btf_id_set8 *set;
7703	u32 set_cnt;
7704	int ret;
7705
7706	if (hook >= BTF_KFUNC_HOOK_MAX) {
7707	ret = -EINVAL;
7708	goto end;
7709	}
7710
7711	if (!add_set->cnt)
7712	return 0;
7713
7714	tab = btf->kfunc_set_tab;
7715
7716	if (tab && add_filter) {
7717	u32 i;
7718
7719	hook_filter = &tab->hook_filters[hook];
7720	for (i = 0; i < hook_filter->nr_filters; i++) {
7721	if (hook_filter->filters[i] == kset->filter) {
7722	add_filter = false;
7723	break;
7724	}
7725	}
7726
7727	if (add_filter && hook_filter->nr_filters == BTF_KFUNC_FILTER_MAX_CNT) {
7728	ret = -E2BIG;
7729	goto end;
7730	}
7731	}
7732
7733	if (!tab) {
7734	tab = kzalloc(size: sizeof(*tab), GFP_KERNEL | __GFP_NOWARN);
7735	if (!tab)
7736	return -ENOMEM;
7737	btf->kfunc_set_tab = tab;
7738	}
7739
7740	set = tab->sets[hook];
7741	/* Warn when register_btf_kfunc_id_set is called twice for the same hook
7742	* for module sets.
7743	*/
7744	if (WARN_ON_ONCE(set && !vmlinux_set)) {
7745	ret = -EINVAL;
7746	goto end;
7747	}
7748
7749	/* We don't need to allocate, concatenate, and sort module sets, because
7750	* only one is allowed per hook. Hence, we can directly assign the
7751	* pointer and return.
7752	*/
7753	if (!vmlinux_set) {
7754	tab->sets[hook] = add_set;
7755	goto do_add_filter;
7756	}
7757
7758	/* In case of vmlinux sets, there may be more than one set being
7759	* registered per hook. To create a unified set, we allocate a new set
7760	* and concatenate all individual sets being registered. While each set
7761	* is individually sorted, they may become unsorted when concatenated,
7762	* hence re-sorting the final set again is required to make binary
7763	* searching the set using btf_id_set8_contains function work.
7764	*/
7765	set_cnt = set ? set->cnt : 0;
7766
7767	if (set_cnt > U32_MAX - add_set->cnt) {
7768	ret = -EOVERFLOW;
7769	goto end;
7770	}
7771
7772	if (set_cnt + add_set->cnt > BTF_KFUNC_SET_MAX_CNT) {
7773	ret = -E2BIG;
7774	goto end;
7775	}
7776
7777	/* Grow set */
7778	set = krealloc(objp: tab->sets[hook],
7779	offsetof(struct btf_id_set8, pairs[set_cnt + add_set->cnt]),
7780	GFP_KERNEL | __GFP_NOWARN);
7781	if (!set) {
7782	ret = -ENOMEM;
7783	goto end;
7784	}
7785
7786	/* For newly allocated set, initialize set->cnt to 0 */
7787	if (!tab->sets[hook])
7788	set->cnt = 0;
7789	tab->sets[hook] = set;
7790
7791	/* Concatenate the two sets */
7792	memcpy(set->pairs + set->cnt, add_set->pairs, add_set->cnt * sizeof(set->pairs[0]));
7793	set->cnt += add_set->cnt;
7794
7795	sort(base: set->pairs, num: set->cnt, size: sizeof(set->pairs[0]), cmp_func: btf_id_cmp_func, NULL);
7796
7797	do_add_filter:
7798	if (add_filter) {
7799	hook_filter = &tab->hook_filters[hook];
7800	hook_filter->filters[hook_filter->nr_filters++] = kset->filter;
7801	}
7802	return 0;
7803	end:
7804	btf_free_kfunc_set_tab(btf);
7805	return ret;
7806	}
7807
7808	static u32 *__btf_kfunc_id_set_contains(const struct btf *btf,
7809	enum btf_kfunc_hook hook,
7810	u32 kfunc_btf_id,
7811	const struct bpf_prog *prog)
7812	{
7813	struct btf_kfunc_hook_filter *hook_filter;
7814	struct btf_id_set8 *set;
7815	u32 *id, i;
7816
7817	if (hook >= BTF_KFUNC_HOOK_MAX)
7818	return NULL;
7819	if (!btf->kfunc_set_tab)
7820	return NULL;
7821	hook_filter = &btf->kfunc_set_tab->hook_filters[hook];
7822	for (i = 0; i < hook_filter->nr_filters; i++) {
7823	if (hook_filter->filters[i](prog, kfunc_btf_id))
7824	return NULL;
7825	}
7826	set = btf->kfunc_set_tab->sets[hook];
7827	if (!set)
7828	return NULL;
7829	id = btf_id_set8_contains(set, id: kfunc_btf_id);
7830	if (!id)
7831	return NULL;
7832	/* The flags for BTF ID are located next to it */
7833	return id + 1;
7834	}
7835
7836	static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)
7837	{
7838	switch (prog_type) {
7839	case BPF_PROG_TYPE_UNSPEC:
7840	return BTF_KFUNC_HOOK_COMMON;
7841	case BPF_PROG_TYPE_XDP:
7842	return BTF_KFUNC_HOOK_XDP;
7843	case BPF_PROG_TYPE_SCHED_CLS:
7844	return BTF_KFUNC_HOOK_TC;
7845	case BPF_PROG_TYPE_STRUCT_OPS:
7846	return BTF_KFUNC_HOOK_STRUCT_OPS;
7847	case BPF_PROG_TYPE_TRACING:
7848	case BPF_PROG_TYPE_LSM:
7849	return BTF_KFUNC_HOOK_TRACING;
7850	case BPF_PROG_TYPE_SYSCALL:
7851	return BTF_KFUNC_HOOK_SYSCALL;
7852	case BPF_PROG_TYPE_CGROUP_SKB:
7853	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
7854	return BTF_KFUNC_HOOK_CGROUP_SKB;
7855	case BPF_PROG_TYPE_SCHED_ACT:
7856	return BTF_KFUNC_HOOK_SCHED_ACT;
7857	case BPF_PROG_TYPE_SK_SKB:
7858	return BTF_KFUNC_HOOK_SK_SKB;
7859	case BPF_PROG_TYPE_SOCKET_FILTER:
7860	return BTF_KFUNC_HOOK_SOCKET_FILTER;
7861	case BPF_PROG_TYPE_LWT_OUT:
7862	case BPF_PROG_TYPE_LWT_IN:
7863	case BPF_PROG_TYPE_LWT_XMIT:
7864	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
7865	return BTF_KFUNC_HOOK_LWT;
7866	case BPF_PROG_TYPE_NETFILTER:
7867	return BTF_KFUNC_HOOK_NETFILTER;
7868	default:
7869	return BTF_KFUNC_HOOK_MAX;
7870	}
7871	}
7872
7873	/* Caution:
7874	* Reference to the module (obtained using btf_try_get_module) corresponding to
7875	* the struct btf *MUST* be held when calling this function from verifier
7876	* context. This is usually true as we stash references in prog's kfunc_btf_tab;
7877	* keeping the reference for the duration of the call provides the necessary
7878	* protection for looking up a well-formed btf->kfunc_set_tab.
7879	*/
7880	u32 *btf_kfunc_id_set_contains(const struct btf *btf,
7881	u32 kfunc_btf_id,
7882	const struct bpf_prog *prog)
7883	{
7884	enum bpf_prog_type prog_type = resolve_prog_type(prog);
7885	enum btf_kfunc_hook hook;
7886	u32 *kfunc_flags;
7887
7888	kfunc_flags = __btf_kfunc_id_set_contains(btf, hook: BTF_KFUNC_HOOK_COMMON, kfunc_btf_id, prog);
7889	if (kfunc_flags)
7890	return kfunc_flags;
7891
7892	hook = bpf_prog_type_to_kfunc_hook(prog_type);
7893	return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id, prog);
7894	}
7895
7896	u32 *btf_kfunc_is_modify_return(const struct btf *btf, u32 kfunc_btf_id,
7897	const struct bpf_prog *prog)
7898	{
7899	return __btf_kfunc_id_set_contains(btf, hook: BTF_KFUNC_HOOK_FMODRET, kfunc_btf_id, prog);
7900	}
7901
7902	static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
7903	const struct btf_kfunc_id_set *kset)
7904	{
7905	struct btf *btf;
7906	int ret, i;
7907
7908	btf = btf_get_module_btf(module: kset->owner);
7909	if (!btf) {
7910	if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
7911	pr_err("missing vmlinux BTF, cannot register kfuncs\n");
7912	return -ENOENT;
7913	}
7914	if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES))
7915	pr_warn("missing module BTF, cannot register kfuncs\n");
7916	return 0;
7917	}
7918	if (IS_ERR(ptr: btf))
7919	return PTR_ERR(ptr: btf);
7920
7921	for (i = 0; i < kset->set->cnt; i++) {
7922	ret = btf_check_kfunc_protos(btf, func_id: kset->set->pairs[i].id,
7923	func_flags: kset->set->pairs[i].flags);
7924	if (ret)
7925	goto err_out;
7926	}
7927
7928	ret = btf_populate_kfunc_set(btf, hook, kset);
7929
7930	err_out:
7931	btf_put(btf);
7932	return ret;
7933	}
7934
7935	/* This function must be invoked only from initcalls/module init functions */
7936	int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
7937	const struct btf_kfunc_id_set *kset)
7938	{
7939	enum btf_kfunc_hook hook;
7940
7941	hook = bpf_prog_type_to_kfunc_hook(prog_type);
7942	return __register_btf_kfunc_id_set(hook, kset);
7943	}
7944	EXPORT_SYMBOL_GPL(register_btf_kfunc_id_set);
7945
7946	/* This function must be invoked only from initcalls/module init functions */
7947	int register_btf_fmodret_id_set(const struct btf_kfunc_id_set *kset)
7948	{
7949	return __register_btf_kfunc_id_set(hook: BTF_KFUNC_HOOK_FMODRET, kset);
7950	}
7951	EXPORT_SYMBOL_GPL(register_btf_fmodret_id_set);
7952
7953	s32 btf_find_dtor_kfunc(struct btf *btf, u32 btf_id)
7954	{
7955	struct btf_id_dtor_kfunc_tab *tab = btf->dtor_kfunc_tab;
7956	struct btf_id_dtor_kfunc *dtor;
7957
7958	if (!tab)
7959	return -ENOENT;
7960	/* Even though the size of tab->dtors[0] is > sizeof(u32), we only need
7961	* to compare the first u32 with btf_id, so we can reuse btf_id_cmp_func.
7962	*/
7963	BUILD_BUG_ON(offsetof(struct btf_id_dtor_kfunc, btf_id) != 0);
7964	dtor = bsearch(key: &btf_id, base: tab->dtors, num: tab->cnt, size: sizeof(tab->dtors[0]), cmp: btf_id_cmp_func);
7965	if (!dtor)
7966	return -ENOENT;
7967	return dtor->kfunc_btf_id;
7968	}
7969
7970	static int btf_check_dtor_kfuncs(struct btf *btf, const struct btf_id_dtor_kfunc *dtors, u32 cnt)
7971	{
7972	const struct btf_type *dtor_func, *dtor_func_proto, *t;
7973	const struct btf_param *args;
7974	s32 dtor_btf_id;
7975	u32 nr_args, i;
7976
7977	for (i = 0; i < cnt; i++) {
7978	dtor_btf_id = dtors[i].kfunc_btf_id;
7979
7980	dtor_func = btf_type_by_id(btf, dtor_btf_id);
7981	if (!dtor_func || !btf_type_is_func(t: dtor_func))
7982	return -EINVAL;
7983
7984	dtor_func_proto = btf_type_by_id(btf, dtor_func->type);
7985	if (!dtor_func_proto || !btf_type_is_func_proto(t: dtor_func_proto))
7986	return -EINVAL;
7987
7988	/* Make sure the prototype of the destructor kfunc is 'void func(type *)' */
7989	t = btf_type_by_id(btf, dtor_func_proto->type);
7990	if (!t || !btf_type_is_void(t))
7991	return -EINVAL;
7992
7993	nr_args = btf_type_vlen(t: dtor_func_proto);
7994	if (nr_args != 1)
7995	return -EINVAL;
7996	args = btf_params(t: dtor_func_proto);
7997	t = btf_type_by_id(btf, args[0].type);
7998	/* Allow any pointer type, as width on targets Linux supports
7999	* will be same for all pointer types (i.e. sizeof(void *))
8000	*/
8001	if (!t || !btf_type_is_ptr(t))
8002	return -EINVAL;
8003	}
8004	return 0;
8005	}
8006
8007	/* This function must be invoked only from initcalls/module init functions */
8008	int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_cnt,
8009	struct module *owner)
8010	{
8011	struct btf_id_dtor_kfunc_tab *tab;
8012	struct btf *btf;
8013	u32 tab_cnt;
8014	int ret;
8015
8016	btf = btf_get_module_btf(module: owner);
8017	if (!btf) {
8018	if (!owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
8019	pr_err("missing vmlinux BTF, cannot register dtor kfuncs\n");
8020	return -ENOENT;
8021	}
8022	if (owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) {
8023	pr_err("missing module BTF, cannot register dtor kfuncs\n");
8024	return -ENOENT;
8025	}
8026	return 0;
8027	}
8028	if (IS_ERR(ptr: btf))
8029	return PTR_ERR(ptr: btf);
8030
8031	if (add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) {
8032	pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT);
8033	ret = -E2BIG;
8034	goto end;
8035	}
8036
8037	/* Ensure that the prototype of dtor kfuncs being registered is sane */
8038	ret = btf_check_dtor_kfuncs(btf, dtors, cnt: add_cnt);
8039	if (ret < 0)
8040	goto end;
8041
8042	tab = btf->dtor_kfunc_tab;
8043	/* Only one call allowed for modules */
8044	if (WARN_ON_ONCE(tab && btf_is_module(btf))) {
8045	ret = -EINVAL;
8046	goto end;
8047	}
8048
8049	tab_cnt = tab ? tab->cnt : 0;
8050	if (tab_cnt > U32_MAX - add_cnt) {
8051	ret = -EOVERFLOW;
8052	goto end;
8053	}
8054	if (tab_cnt + add_cnt >= BTF_DTOR_KFUNC_MAX_CNT) {
8055	pr_err("cannot register more than %d kfunc destructors\n", BTF_DTOR_KFUNC_MAX_CNT);
8056	ret = -E2BIG;
8057	goto end;
8058	}
8059
8060	tab = krealloc(objp: btf->dtor_kfunc_tab,
8061	offsetof(struct btf_id_dtor_kfunc_tab, dtors[tab_cnt + add_cnt]),
8062	GFP_KERNEL | __GFP_NOWARN);
8063	if (!tab) {
8064	ret = -ENOMEM;
8065	goto end;
8066	}
8067
8068	if (!btf->dtor_kfunc_tab)
8069	tab->cnt = 0;
8070	btf->dtor_kfunc_tab = tab;
8071
8072	memcpy(tab->dtors + tab->cnt, dtors, add_cnt * sizeof(tab->dtors[0]));
8073	tab->cnt += add_cnt;
8074
8075	sort(base: tab->dtors, num: tab->cnt, size: sizeof(tab->dtors[0]), cmp_func: btf_id_cmp_func, NULL);
8076
8077	end:
8078	if (ret)
8079	btf_free_dtor_kfunc_tab(btf);
8080	btf_put(btf);
8081	return ret;
8082	}
8083	EXPORT_SYMBOL_GPL(register_btf_id_dtor_kfuncs);
8084
8085	#define MAX_TYPES_ARE_COMPAT_DEPTH 2
8086
8087	/* Check local and target types for compatibility. This check is used for
8088	* type-based CO-RE relocations and follow slightly different rules than
8089	* field-based relocations. This function assumes that root types were already
8090	* checked for name match. Beyond that initial root-level name check, names
8091	* are completely ignored. Compatibility rules are as follows:
8092	* - any two STRUCTs/UNIONs/FWDs/ENUMs/INTs/ENUM64s are considered compatible, but
8093	* kind should match for local and target types (i.e., STRUCT is not
8094	* compatible with UNION);
8095	* - for ENUMs/ENUM64s, the size is ignored;
8096	* - for INT, size and signedness are ignored;
8097	* - for ARRAY, dimensionality is ignored, element types are checked for
8098	* compatibility recursively;
8099	* - CONST/VOLATILE/RESTRICT modifiers are ignored;
8100	* - TYPEDEFs/PTRs are compatible if types they pointing to are compatible;
8101	* - FUNC_PROTOs are compatible if they have compatible signature: same
8102	* number of input args and compatible return and argument types.
8103	* These rules are not set in stone and probably will be adjusted as we get
8104	* more experience with using BPF CO-RE relocations.
8105	*/
8106	int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id,
8107	const struct btf *targ_btf, __u32 targ_id)
8108	{
8109	return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id,
8110	MAX_TYPES_ARE_COMPAT_DEPTH);
8111	}
8112
8113	#define MAX_TYPES_MATCH_DEPTH 2
8114
8115	int bpf_core_types_match(const struct btf *local_btf, u32 local_id,
8116	const struct btf *targ_btf, u32 targ_id)
8117	{
8118	return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, behind_ptr: false,
8119	MAX_TYPES_MATCH_DEPTH);
8120	}
8121
8122	static bool bpf_core_is_flavor_sep(const char *s)
8123	{
8124	/* check X___Y name pattern, where X and Y are not underscores */
8125	return s[0] != '_' && /* X */
8126	s[1] == '_' && s[2] == '_' && s[3] == '_' && /* ___ */
8127	s[4] != '_'; /* Y */
8128	}
8129
8130	size_t bpf_core_essential_name_len(const char *name)
8131	{
8132	size_t n = strlen(name);
8133	int i;
8134
8135	for (i = n - 5; i >= 0; i--) {
8136	if (bpf_core_is_flavor_sep(s: name + i))
8137	return i + 1;
8138	}
8139	return n;
8140	}
8141
8142	struct bpf_cand_cache {
8143	const char *name;
8144	u32 name_len;
8145	u16 kind;
8146	u16 cnt;
8147	struct {
8148	const struct btf *btf;
8149	u32 id;
8150	} cands[];
8151	};
8152
8153	static void bpf_free_cands(struct bpf_cand_cache *cands)
8154	{
8155	if (!cands->cnt)
8156	/* empty candidate array was allocated on stack */
8157	return;
8158	kfree(objp: cands);
8159	}
8160
8161	static void bpf_free_cands_from_cache(struct bpf_cand_cache *cands)
8162	{
8163	kfree(objp: cands->name);
8164	kfree(objp: cands);
8165	}
8166
8167	#define VMLINUX_CAND_CACHE_SIZE 31
8168	static struct bpf_cand_cache *vmlinux_cand_cache[VMLINUX_CAND_CACHE_SIZE];
8169
8170	#define MODULE_CAND_CACHE_SIZE 31
8171	static struct bpf_cand_cache *module_cand_cache[MODULE_CAND_CACHE_SIZE];
8172
8173	static DEFINE_MUTEX(cand_cache_mutex);
8174
8175	static void __print_cand_cache(struct bpf_verifier_log *log,
8176	struct bpf_cand_cache **cache,
8177	int cache_size)
8178	{
8179	struct bpf_cand_cache *cc;
8180	int i, j;
8181
8182	for (i = 0; i < cache_size; i++) {
8183	cc = cache[i];
8184	if (!cc)
8185	continue;
8186	bpf_log(log, fmt: "[%d]%s(", i, cc->name);
8187	for (j = 0; j < cc->cnt; j++) {
8188	bpf_log(log, fmt: "%d", cc->cands[j].id);
8189	if (j < cc->cnt - 1)
8190	bpf_log(log, fmt: " ");
8191	}
8192	bpf_log(log, fmt: "), ");
8193	}
8194	}
8195
8196	static void print_cand_cache(struct bpf_verifier_log *log)
8197	{
8198	mutex_lock(&cand_cache_mutex);
8199	bpf_log(log, fmt: "vmlinux_cand_cache:");
8200	__print_cand_cache(log, cache: vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE);
8201	bpf_log(log, fmt: "\nmodule_cand_cache:");
8202	__print_cand_cache(log, cache: module_cand_cache, MODULE_CAND_CACHE_SIZE);
8203	bpf_log(log, fmt: "\n");
8204	mutex_unlock(lock: &cand_cache_mutex);
8205	}
8206
8207	static u32 hash_cands(struct bpf_cand_cache *cands)
8208	{
8209	return jhash(key: cands->name, length: cands->name_len, initval: 0);
8210	}
8211
8212	static struct bpf_cand_cache *check_cand_cache(struct bpf_cand_cache *cands,
8213	struct bpf_cand_cache **cache,
8214	int cache_size)
8215	{
8216	struct bpf_cand_cache *cc = cache[hash_cands(cands) % cache_size];
8217
8218	if (cc && cc->name_len == cands->name_len &&
8219	!strncmp(cc->name, cands->name, cands->name_len))
8220	return cc;
8221	return NULL;
8222	}
8223
8224	static size_t sizeof_cands(int cnt)
8225	{
8226	return offsetof(struct bpf_cand_cache, cands[cnt]);
8227	}
8228
8229	static struct bpf_cand_cache *populate_cand_cache(struct bpf_cand_cache *cands,
8230	struct bpf_cand_cache **cache,
8231	int cache_size)
8232	{
8233	struct bpf_cand_cache **cc = &cache[hash_cands(cands) % cache_size], *new_cands;
8234
8235	if (*cc) {
8236	bpf_free_cands_from_cache(cands: *cc);
8237	*cc = NULL;
8238	}
8239	new_cands = kmemdup(p: cands, size: sizeof_cands(cnt: cands->cnt), GFP_KERNEL);
8240	if (!new_cands) {
8241	bpf_free_cands(cands);
8242	return ERR_PTR(error: -ENOMEM);
8243	}
8244	/* strdup the name, since it will stay in cache.
8245	* the cands->name points to strings in prog's BTF and the prog can be unloaded.
8246	*/
8247	new_cands->name = kmemdup_nul(s: cands->name, len: cands->name_len, GFP_KERNEL);
8248	bpf_free_cands(cands);
8249	if (!new_cands->name) {
8250	kfree(objp: new_cands);
8251	return ERR_PTR(error: -ENOMEM);
8252	}
8253	*cc = new_cands;
8254	return new_cands;
8255	}
8256
8257	#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
8258	static void __purge_cand_cache(struct btf *btf, struct bpf_cand_cache **cache,
8259	int cache_size)
8260	{
8261	struct bpf_cand_cache *cc;
8262	int i, j;
8263
8264	for (i = 0; i < cache_size; i++) {
8265	cc = cache[i];
8266	if (!cc)
8267	continue;
8268	if (!btf) {
8269	/* when new module is loaded purge all of module_cand_cache,
8270	* since new module might have candidates with the name
8271	* that matches cached cands.
8272	*/
8273	bpf_free_cands_from_cache(cc);
8274	cache[i] = NULL;
8275	continue;
8276	}
8277	/* when module is unloaded purge cache entries
8278	* that match module's btf
8279	*/
8280	for (j = 0; j < cc->cnt; j++)
8281	if (cc->cands[j].btf == btf) {
8282	bpf_free_cands_from_cache(cc);
8283	cache[i] = NULL;
8284	break;
8285	}
8286	}
8287
8288	}
8289
8290	static void purge_cand_cache(struct btf *btf)
8291	{
8292	mutex_lock(&cand_cache_mutex);
8293	__purge_cand_cache(btf, module_cand_cache, MODULE_CAND_CACHE_SIZE);
8294	mutex_unlock(&cand_cache_mutex);
8295	}
8296	#endif
8297
8298	static struct bpf_cand_cache *
8299	bpf_core_add_cands(struct bpf_cand_cache *cands, const struct btf *targ_btf,
8300	int targ_start_id)
8301	{
8302	struct bpf_cand_cache *new_cands;
8303	const struct btf_type *t;
8304	const char *targ_name;
8305	size_t targ_essent_len;
8306	int n, i;
8307
8308	n = btf_nr_types(btf: targ_btf);
8309	for (i = targ_start_id; i < n; i++) {
8310	t = btf_type_by_id(targ_btf, i);
8311	if (btf_kind(t) != cands->kind)
8312	continue;
8313
8314	targ_name = btf_name_by_offset(btf: targ_btf, offset: t->name_off);
8315	if (!targ_name)
8316	continue;
8317
8318	/* the resched point is before strncmp to make sure that search
8319	* for non-existing name will have a chance to schedule().
8320	*/
8321	cond_resched();
8322
8323	if (strncmp(cands->name, targ_name, cands->name_len) != 0)
8324	continue;
8325
8326	targ_essent_len = bpf_core_essential_name_len(name: targ_name);
8327	if (targ_essent_len != cands->name_len)
8328	continue;
8329
8330	/* most of the time there is only one candidate for a given kind+name pair */
8331	new_cands = kmalloc(size: sizeof_cands(cnt: cands->cnt + 1), GFP_KERNEL);
8332	if (!new_cands) {
8333	bpf_free_cands(cands);
8334	return ERR_PTR(error: -ENOMEM);
8335	}
8336
8337	memcpy(new_cands, cands, sizeof_cands(cands->cnt));
8338	bpf_free_cands(cands);
8339	cands = new_cands;
8340	cands->cands[cands->cnt].btf = targ_btf;
8341	cands->cands[cands->cnt].id = i;
8342	cands->cnt++;
8343	}
8344	return cands;
8345	}
8346
8347	static struct bpf_cand_cache *
8348	bpf_core_find_cands(struct bpf_core_ctx *ctx, u32 local_type_id)
8349	{
8350	struct bpf_cand_cache *cands, *cc, local_cand = {};
8351	const struct btf *local_btf = ctx->btf;
8352	const struct btf_type *local_type;
8353	const struct btf *main_btf;
8354	size_t local_essent_len;
8355	struct btf *mod_btf;
8356	const char *name;
8357	int id;
8358
8359	main_btf = bpf_get_btf_vmlinux();
8360	if (IS_ERR(ptr: main_btf))
8361	return ERR_CAST(ptr: main_btf);
8362	if (!main_btf)
8363	return ERR_PTR(error: -EINVAL);
8364
8365	local_type = btf_type_by_id(local_btf, local_type_id);
8366	if (!local_type)
8367	return ERR_PTR(error: -EINVAL);
8368
8369	name = btf_name_by_offset(btf: local_btf, offset: local_type->name_off);
8370	if (str_is_empty(s: name))
8371	return ERR_PTR(error: -EINVAL);
8372	local_essent_len = bpf_core_essential_name_len(name);
8373
8374	cands = &local_cand;
8375	cands->name = name;
8376	cands->kind = btf_kind(t: local_type);
8377	cands->name_len = local_essent_len;
8378
8379	cc = check_cand_cache(cands, cache: vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE);
8380	/* cands is a pointer to stack here */
8381	if (cc) {
8382	if (cc->cnt)
8383	return cc;
8384	goto check_modules;
8385	}
8386
8387	/* Attempt to find target candidates in vmlinux BTF first */
8388	cands = bpf_core_add_cands(cands, targ_btf: main_btf, targ_start_id: 1);
8389	if (IS_ERR(ptr: cands))
8390	return ERR_CAST(ptr: cands);
8391
8392	/* cands is a pointer to kmalloced memory here if cands->cnt > 0 */
8393
8394	/* populate cache even when cands->cnt == 0 */
8395	cc = populate_cand_cache(cands, cache: vmlinux_cand_cache, VMLINUX_CAND_CACHE_SIZE);
8396	if (IS_ERR(ptr: cc))
8397	return ERR_CAST(ptr: cc);
8398
8399	/* if vmlinux BTF has any candidate, don't go for module BTFs */
8400	if (cc->cnt)
8401	return cc;
8402
8403	check_modules:
8404	/* cands is a pointer to stack here and cands->cnt == 0 */
8405	cc = check_cand_cache(cands, cache: module_cand_cache, MODULE_CAND_CACHE_SIZE);
8406	if (cc)
8407	/* if cache has it return it even if cc->cnt == 0 */
8408	return cc;
8409
8410	/* If candidate is not found in vmlinux's BTF then search in module's BTFs */
8411	spin_lock_bh(lock: &btf_idr_lock);
8412	idr_for_each_entry(&btf_idr, mod_btf, id) {
8413	if (!btf_is_module(btf: mod_btf))
8414	continue;
8415	/* linear search could be slow hence unlock/lock
8416	* the IDR to avoiding holding it for too long
8417	*/
8418	btf_get(btf: mod_btf);
8419	spin_unlock_bh(lock: &btf_idr_lock);
8420	cands = bpf_core_add_cands(cands, targ_btf: mod_btf, targ_start_id: btf_nr_types(btf: main_btf));
8421	btf_put(btf: mod_btf);
8422	if (IS_ERR(ptr: cands))
8423	return ERR_CAST(ptr: cands);
8424	spin_lock_bh(lock: &btf_idr_lock);
8425	}
8426	spin_unlock_bh(lock: &btf_idr_lock);
8427	/* cands is a pointer to kmalloced memory here if cands->cnt > 0
8428	* or pointer to stack if cands->cnd == 0.
8429	* Copy it into the cache even when cands->cnt == 0 and
8430	* return the result.
8431	*/
8432	return populate_cand_cache(cands, cache: module_cand_cache, MODULE_CAND_CACHE_SIZE);
8433	}
8434
8435	int bpf_core_apply(struct bpf_core_ctx *ctx, const struct bpf_core_relo *relo,
8436	int relo_idx, void *insn)
8437	{
8438	bool need_cands = relo->kind != BPF_CORE_TYPE_ID_LOCAL;
8439	struct bpf_core_cand_list cands = {};
8440	struct bpf_core_relo_res targ_res;
8441	struct bpf_core_spec *specs;
8442	int err;
8443
8444	/* ~4k of temp memory necessary to convert LLVM spec like "0:1:0:5"
8445	* into arrays of btf_ids of struct fields and array indices.
8446	*/
8447	specs = kcalloc(n: 3, size: sizeof(*specs), GFP_KERNEL);
8448	if (!specs)
8449	return -ENOMEM;
8450
8451	if (need_cands) {
8452	struct bpf_cand_cache *cc;
8453	int i;
8454
8455	mutex_lock(&cand_cache_mutex);
8456	cc = bpf_core_find_cands(ctx, local_type_id: relo->type_id);
8457	if (IS_ERR(ptr: cc)) {
8458	bpf_log(log: ctx->log, fmt: "target candidate search failed for %d\n",
8459	relo->type_id);
8460	err = PTR_ERR(ptr: cc);
8461	goto out;
8462	}
8463	if (cc->cnt) {
8464	cands.cands = kcalloc(n: cc->cnt, size: sizeof(*cands.cands), GFP_KERNEL);
8465	if (!cands.cands) {
8466	err = -ENOMEM;
8467	goto out;
8468	}
8469	}
8470	for (i = 0; i < cc->cnt; i++) {
8471	bpf_log(log: ctx->log,
8472	fmt: "CO-RE relocating %s %s: found target candidate [%d]\n",
8473	btf_kind_str[cc->kind], cc->name, cc->cands[i].id);
8474	cands.cands[i].btf = cc->cands[i].btf;
8475	cands.cands[i].id = cc->cands[i].id;
8476	}
8477	cands.len = cc->cnt;
8478	/* cand_cache_mutex needs to span the cache lookup and
8479	* copy of btf pointer into bpf_core_cand_list,
8480	* since module can be unloaded while bpf_core_calc_relo_insn
8481	* is working with module's btf.
8482	*/
8483	}
8484
8485	err = bpf_core_calc_relo_insn(prog_name: (void *)ctx->log, relo, relo_idx, local_btf: ctx->btf, cands: &cands, specs_scratch: specs,
8486	targ_res: &targ_res);
8487	if (err)
8488	goto out;
8489
8490	err = bpf_core_patch_insn(prog_name: (void *)ctx->log, insn, insn_idx: relo->insn_off / 8, relo, relo_idx,
8491	res: &targ_res);
8492
8493	out:
8494	kfree(objp: specs);
8495	if (need_cands) {
8496	kfree(objp: cands.cands);
8497	mutex_unlock(lock: &cand_cache_mutex);
8498	if (ctx->log->level & BPF_LOG_LEVEL2)
8499	print_cand_cache(log: ctx->log);
8500	}
8501	return err;
8502	}
8503
8504	bool btf_nested_type_is_trusted(struct bpf_verifier_log *log,
8505	const struct bpf_reg_state *reg,
8506	const char *field_name, u32 btf_id, const char *suffix)
8507	{
8508	struct btf *btf = reg->btf;
8509	const struct btf_type *walk_type, *safe_type;
8510	const char *tname;
8511	char safe_tname[64];
8512	long ret, safe_id;
8513	const struct btf_member *member;
8514	u32 i;
8515
8516	walk_type = btf_type_by_id(btf, reg->btf_id);
8517	if (!walk_type)
8518	return false;
8519
8520	tname = btf_name_by_offset(btf, offset: walk_type->name_off);
8521
8522	ret = snprintf(buf: safe_tname, size: sizeof(safe_tname), fmt: "%s%s", tname, suffix);
8523	if (ret >= sizeof(safe_tname))
8524	return false;
8525
8526	safe_id = btf_find_by_name_kind(btf, name: safe_tname, BTF_INFO_KIND(walk_type->info));
8527	if (safe_id < 0)
8528	return false;
8529
8530	safe_type = btf_type_by_id(btf, safe_id);
8531	if (!safe_type)
8532	return false;
8533
8534	for_each_member(i, safe_type, member) {
8535	const char *m_name = __btf_name_by_offset(btf, offset: member->name_off);
8536	const struct btf_type *mtype = btf_type_by_id(btf, member->type);
8537	u32 id;
8538
8539	if (!btf_type_is_ptr(t: mtype))
8540	continue;
8541
8542	btf_type_skip_modifiers(btf, id: mtype->type, res_id: &id);
8543	/* If we match on both type and name, the field is considered trusted. */
8544	if (btf_id == id && !strcmp(field_name, m_name))
8545	return true;
8546	}
8547
8548	return false;
8549	}
8550
8551	bool btf_type_ids_nocast_alias(struct bpf_verifier_log *log,
8552	const struct btf *reg_btf, u32 reg_id,
8553	const struct btf *arg_btf, u32 arg_id)
8554	{
8555	const char *reg_name, *arg_name, *search_needle;
8556	const struct btf_type *reg_type, *arg_type;
8557	int reg_len, arg_len, cmp_len;
8558	size_t pattern_len = sizeof(NOCAST_ALIAS_SUFFIX) - sizeof(char);
8559
8560	reg_type = btf_type_by_id(reg_btf, reg_id);
8561	if (!reg_type)
8562	return false;
8563
8564	arg_type = btf_type_by_id(arg_btf, arg_id);
8565	if (!arg_type)
8566	return false;
8567
8568	reg_name = btf_name_by_offset(btf: reg_btf, offset: reg_type->name_off);
8569	arg_name = btf_name_by_offset(btf: arg_btf, offset: arg_type->name_off);
8570
8571	reg_len = strlen(reg_name);
8572	arg_len = strlen(arg_name);
8573
8574	/* Exactly one of the two type names may be suffixed with ___init, so
8575	* if the strings are the same size, they can't possibly be no-cast
8576	* aliases of one another. If you have two of the same type names, e.g.
8577	* they're both nf_conn___init, it would be improper to return true
8578	* because they are _not_ no-cast aliases, they are the same type.
8579	*/
8580	if (reg_len == arg_len)
8581	return false;
8582
8583	/* Either of the two names must be the other name, suffixed with ___init. */
8584	if ((reg_len != arg_len + pattern_len) &&
8585	(arg_len != reg_len + pattern_len))
8586	return false;
8587
8588	if (reg_len < arg_len) {
8589	search_needle = strstr(arg_name, NOCAST_ALIAS_SUFFIX);
8590	cmp_len = reg_len;
8591	} else {
8592	search_needle = strstr(reg_name, NOCAST_ALIAS_SUFFIX);
8593	cmp_len = arg_len;
8594	}
8595
8596	if (!search_needle)
8597	return false;
8598
8599	/* ___init suffix must come at the end of the name */
8600	if (*(search_needle + pattern_len) != '\0')
8601	return false;
8602
8603	return !strncmp(reg_name, arg_name, cmp_len);
8604	}
8605