xref: /linux/kernel/bpf/helpers.c (revision 4a98c2efa613f0b01bc3aa0acb8c3ff7ae29b6f9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3  */
4 #include <linux/bpf.h>
5 #include <linux/btf.h>
6 #include <linux/bpf-cgroup.h>
7 #include <linux/cgroup.h>
8 #include <linux/rcupdate.h>
9 #include <linux/random.h>
10 #include <linux/smp.h>
11 #include <linux/topology.h>
12 #include <linux/ktime.h>
13 #include <linux/sched.h>
14 #include <linux/uidgid.h>
15 #include <linux/filter.h>
16 #include <linux/ctype.h>
17 #include <linux/jiffies.h>
18 #include <linux/pid_namespace.h>
19 #include <linux/poison.h>
20 #include <linux/proc_ns.h>
21 #include <linux/sched/task.h>
22 #include <linux/security.h>
23 #include <linux/btf_ids.h>
24 #include <linux/bpf_mem_alloc.h>
25 #include <linux/kasan.h>
26 #include <linux/bpf_verifier.h>
27 #include <linux/uaccess.h>
28 #include <linux/verification.h>
29 #include <linux/task_work.h>
30 #include <linux/irq_work.h>
31 #include <linux/buildid.h>
32 
33 #include "../../lib/kstrtox.h"
34 
35 /* If kernel subsystem is allowing eBPF programs to call this function,
36  * inside its own verifier_ops->get_func_proto() callback it should return
37  * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
38  *
39  * Different map implementations will rely on rcu in map methods
40  * lookup/update/delete, therefore eBPF programs must run under rcu lock
41  * if program is allowed to access maps, so check rcu_read_lock_held() or
42  * rcu_read_lock_trace_held() in all three functions.
43  */
44 BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
45 {
46 	WARN_ON_ONCE(!bpf_rcu_lock_held());
47 	return (unsigned long) map->ops->map_lookup_elem(map, key);
48 }
49 
50 const struct bpf_func_proto bpf_map_lookup_elem_proto = {
51 	.func		= bpf_map_lookup_elem,
52 	.gpl_only	= false,
53 	.pkt_access	= true,
54 	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
55 	.arg1_type	= ARG_CONST_MAP_PTR,
56 	.arg2_type	= ARG_PTR_TO_MAP_KEY,
57 };
58 
59 BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
60 	   void *, value, u64, flags)
61 {
62 	WARN_ON_ONCE(!bpf_rcu_lock_held());
63 	return map->ops->map_update_elem(map, key, value, flags);
64 }
65 
66 const struct bpf_func_proto bpf_map_update_elem_proto = {
67 	.func		= bpf_map_update_elem,
68 	.gpl_only	= false,
69 	.pkt_access	= true,
70 	.ret_type	= RET_INTEGER,
71 	.arg1_type	= ARG_CONST_MAP_PTR,
72 	.arg2_type	= ARG_PTR_TO_MAP_KEY,
73 	.arg3_type	= ARG_PTR_TO_MAP_VALUE,
74 	.arg4_type	= ARG_ANYTHING,
75 };
76 
77 BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
78 {
79 	WARN_ON_ONCE(!bpf_rcu_lock_held());
80 	return map->ops->map_delete_elem(map, key);
81 }
82 
83 const struct bpf_func_proto bpf_map_delete_elem_proto = {
84 	.func		= bpf_map_delete_elem,
85 	.gpl_only	= false,
86 	.pkt_access	= true,
87 	.ret_type	= RET_INTEGER,
88 	.arg1_type	= ARG_CONST_MAP_PTR,
89 	.arg2_type	= ARG_PTR_TO_MAP_KEY,
90 };
91 
92 BPF_CALL_3(bpf_map_push_elem, struct bpf_map *, map, void *, value, u64, flags)
93 {
94 	return map->ops->map_push_elem(map, value, flags);
95 }
96 
97 const struct bpf_func_proto bpf_map_push_elem_proto = {
98 	.func		= bpf_map_push_elem,
99 	.gpl_only	= false,
100 	.pkt_access	= true,
101 	.ret_type	= RET_INTEGER,
102 	.arg1_type	= ARG_CONST_MAP_PTR,
103 	.arg2_type	= ARG_PTR_TO_MAP_VALUE,
104 	.arg3_type	= ARG_ANYTHING,
105 };
106 
107 BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value)
108 {
109 	return map->ops->map_pop_elem(map, value);
110 }
111 
112 const struct bpf_func_proto bpf_map_pop_elem_proto = {
113 	.func		= bpf_map_pop_elem,
114 	.gpl_only	= false,
115 	.ret_type	= RET_INTEGER,
116 	.arg1_type	= ARG_CONST_MAP_PTR,
117 	.arg2_type	= ARG_PTR_TO_MAP_VALUE | MEM_UNINIT | MEM_WRITE,
118 };
119 
120 BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value)
121 {
122 	return map->ops->map_peek_elem(map, value);
123 }
124 
125 const struct bpf_func_proto bpf_map_peek_elem_proto = {
126 	.func		= bpf_map_peek_elem,
127 	.gpl_only	= false,
128 	.ret_type	= RET_INTEGER,
129 	.arg1_type	= ARG_CONST_MAP_PTR,
130 	.arg2_type	= ARG_PTR_TO_MAP_VALUE | MEM_UNINIT | MEM_WRITE,
131 };
132 
133 BPF_CALL_3(bpf_map_lookup_percpu_elem, struct bpf_map *, map, void *, key, u32, cpu)
134 {
135 	WARN_ON_ONCE(!bpf_rcu_lock_held());
136 	return (unsigned long) map->ops->map_lookup_percpu_elem(map, key, cpu);
137 }
138 
139 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto = {
140 	.func		= bpf_map_lookup_percpu_elem,
141 	.gpl_only	= false,
142 	.pkt_access	= true,
143 	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
144 	.arg1_type	= ARG_CONST_MAP_PTR,
145 	.arg2_type	= ARG_PTR_TO_MAP_KEY,
146 	.arg3_type	= ARG_ANYTHING,
147 };
148 
149 const struct bpf_func_proto bpf_get_prandom_u32_proto = {
150 	.func		= bpf_user_rnd_u32,
151 	.gpl_only	= false,
152 	.ret_type	= RET_INTEGER,
153 };
154 
155 BPF_CALL_0(bpf_get_smp_processor_id)
156 {
157 	return smp_processor_id();
158 }
159 
160 const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
161 	.func		= bpf_get_smp_processor_id,
162 	.gpl_only	= false,
163 	.ret_type	= RET_INTEGER,
164 	.allow_fastcall	= true,
165 };
166 
167 BPF_CALL_0(bpf_get_numa_node_id)
168 {
169 	return numa_node_id();
170 }
171 
172 const struct bpf_func_proto bpf_get_numa_node_id_proto = {
173 	.func		= bpf_get_numa_node_id,
174 	.gpl_only	= false,
175 	.ret_type	= RET_INTEGER,
176 };
177 
178 BPF_CALL_0(bpf_ktime_get_ns)
179 {
180 	/* NMI safe access to clock monotonic */
181 	return ktime_get_mono_fast_ns();
182 }
183 
184 const struct bpf_func_proto bpf_ktime_get_ns_proto = {
185 	.func		= bpf_ktime_get_ns,
186 	.gpl_only	= false,
187 	.ret_type	= RET_INTEGER,
188 };
189 
190 BPF_CALL_0(bpf_ktime_get_boot_ns)
191 {
192 	/* NMI safe access to clock boottime */
193 	return ktime_get_boot_fast_ns();
194 }
195 
196 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = {
197 	.func		= bpf_ktime_get_boot_ns,
198 	.gpl_only	= false,
199 	.ret_type	= RET_INTEGER,
200 };
201 
202 BPF_CALL_0(bpf_ktime_get_coarse_ns)
203 {
204 	return ktime_get_coarse_ns();
205 }
206 
207 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto = {
208 	.func		= bpf_ktime_get_coarse_ns,
209 	.gpl_only	= false,
210 	.ret_type	= RET_INTEGER,
211 };
212 
213 BPF_CALL_0(bpf_ktime_get_tai_ns)
214 {
215 	/* NMI safe access to clock tai */
216 	return ktime_get_tai_fast_ns();
217 }
218 
219 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto = {
220 	.func		= bpf_ktime_get_tai_ns,
221 	.gpl_only	= false,
222 	.ret_type	= RET_INTEGER,
223 };
224 
225 BPF_CALL_0(bpf_get_current_pid_tgid)
226 {
227 	struct task_struct *task = current;
228 
229 	if (unlikely(!task))
230 		return -EINVAL;
231 
232 	return (u64) task->tgid << 32 | task->pid;
233 }
234 
235 const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
236 	.func		= bpf_get_current_pid_tgid,
237 	.gpl_only	= false,
238 	.ret_type	= RET_INTEGER,
239 };
240 
241 BPF_CALL_0(bpf_get_current_uid_gid)
242 {
243 	struct task_struct *task = current;
244 	kuid_t uid;
245 	kgid_t gid;
246 
247 	if (unlikely(!task))
248 		return -EINVAL;
249 
250 	current_uid_gid(&uid, &gid);
251 	return (u64) from_kgid(&init_user_ns, gid) << 32 |
252 		     from_kuid(&init_user_ns, uid);
253 }
254 
255 const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
256 	.func		= bpf_get_current_uid_gid,
257 	.gpl_only	= false,
258 	.ret_type	= RET_INTEGER,
259 };
260 
261 BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size)
262 {
263 	struct task_struct *task = current;
264 
265 	if (unlikely(!task))
266 		goto err_clear;
267 
268 	/* Verifier guarantees that size > 0 */
269 	strscpy_pad(buf, task->comm, size);
270 	return 0;
271 err_clear:
272 	memset(buf, 0, size);
273 	return -EINVAL;
274 }
275 
276 const struct bpf_func_proto bpf_get_current_comm_proto = {
277 	.func		= bpf_get_current_comm,
278 	.gpl_only	= false,
279 	.ret_type	= RET_INTEGER,
280 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
281 	.arg2_type	= ARG_CONST_SIZE,
282 };
283 
284 #if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK)
285 
286 static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
287 {
288 	arch_spinlock_t *l = (void *)lock;
289 	union {
290 		__u32 val;
291 		arch_spinlock_t lock;
292 	} u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED };
293 
294 	compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0");
295 	BUILD_BUG_ON(sizeof(*l) != sizeof(__u32));
296 	BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32));
297 	preempt_disable();
298 	arch_spin_lock(l);
299 }
300 
301 static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
302 {
303 	arch_spinlock_t *l = (void *)lock;
304 
305 	arch_spin_unlock(l);
306 	preempt_enable();
307 }
308 
309 #else
310 
311 static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
312 {
313 	atomic_t *l = (void *)lock;
314 
315 	BUILD_BUG_ON(sizeof(*l) != sizeof(*lock));
316 	do {
317 		atomic_cond_read_relaxed(l, !VAL);
318 	} while (atomic_xchg(l, 1));
319 }
320 
321 static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
322 {
323 	atomic_t *l = (void *)lock;
324 
325 	atomic_set_release(l, 0);
326 }
327 
328 #endif
329 
330 static DEFINE_PER_CPU(unsigned long, irqsave_flags);
331 
332 static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock)
333 {
334 	unsigned long flags;
335 
336 	local_irq_save(flags);
337 	__bpf_spin_lock(lock);
338 	__this_cpu_write(irqsave_flags, flags);
339 }
340 
341 NOTRACE_BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
342 {
343 	__bpf_spin_lock_irqsave(lock);
344 	return 0;
345 }
346 
347 const struct bpf_func_proto bpf_spin_lock_proto = {
348 	.func		= bpf_spin_lock,
349 	.gpl_only	= false,
350 	.ret_type	= RET_VOID,
351 	.arg1_type	= ARG_PTR_TO_SPIN_LOCK,
352 	.arg1_btf_id    = BPF_PTR_POISON,
353 };
354 
355 static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
356 {
357 	unsigned long flags;
358 
359 	flags = __this_cpu_read(irqsave_flags);
360 	__bpf_spin_unlock(lock);
361 	local_irq_restore(flags);
362 }
363 
364 NOTRACE_BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
365 {
366 	__bpf_spin_unlock_irqrestore(lock);
367 	return 0;
368 }
369 
370 const struct bpf_func_proto bpf_spin_unlock_proto = {
371 	.func		= bpf_spin_unlock,
372 	.gpl_only	= false,
373 	.ret_type	= RET_VOID,
374 	.arg1_type	= ARG_PTR_TO_SPIN_LOCK,
375 	.arg1_btf_id    = BPF_PTR_POISON,
376 };
377 
378 void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
379 			   bool lock_src)
380 {
381 	struct bpf_spin_lock *lock;
382 
383 	if (lock_src)
384 		lock = src + map->record->spin_lock_off;
385 	else
386 		lock = dst + map->record->spin_lock_off;
387 	preempt_disable();
388 	__bpf_spin_lock_irqsave(lock);
389 	copy_map_value(map, dst, src);
390 	__bpf_spin_unlock_irqrestore(lock);
391 	preempt_enable();
392 }
393 
394 BPF_CALL_0(bpf_jiffies64)
395 {
396 	return get_jiffies_64();
397 }
398 
399 const struct bpf_func_proto bpf_jiffies64_proto = {
400 	.func		= bpf_jiffies64,
401 	.gpl_only	= false,
402 	.ret_type	= RET_INTEGER,
403 };
404 
405 #ifdef CONFIG_CGROUPS
406 BPF_CALL_0(bpf_get_current_cgroup_id)
407 {
408 	struct cgroup *cgrp;
409 	u64 cgrp_id;
410 
411 	rcu_read_lock();
412 	cgrp = task_dfl_cgroup(current);
413 	cgrp_id = cgroup_id(cgrp);
414 	rcu_read_unlock();
415 
416 	return cgrp_id;
417 }
418 
419 const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
420 	.func		= bpf_get_current_cgroup_id,
421 	.gpl_only	= false,
422 	.ret_type	= RET_INTEGER,
423 };
424 
425 BPF_CALL_1(bpf_get_current_ancestor_cgroup_id, int, ancestor_level)
426 {
427 	struct cgroup *cgrp;
428 	struct cgroup *ancestor;
429 	u64 cgrp_id;
430 
431 	rcu_read_lock();
432 	cgrp = task_dfl_cgroup(current);
433 	ancestor = cgroup_ancestor(cgrp, ancestor_level);
434 	cgrp_id = ancestor ? cgroup_id(ancestor) : 0;
435 	rcu_read_unlock();
436 
437 	return cgrp_id;
438 }
439 
440 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {
441 	.func		= bpf_get_current_ancestor_cgroup_id,
442 	.gpl_only	= false,
443 	.ret_type	= RET_INTEGER,
444 	.arg1_type	= ARG_ANYTHING,
445 };
446 #endif /* CONFIG_CGROUPS */
447 
448 #define BPF_STRTOX_BASE_MASK 0x1F
449 
450 static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
451 			  unsigned long long *res, bool *is_negative)
452 {
453 	unsigned int base = flags & BPF_STRTOX_BASE_MASK;
454 	const char *cur_buf = buf;
455 	size_t cur_len = buf_len;
456 	unsigned int consumed;
457 	size_t val_len;
458 	char str[64];
459 
460 	if (!buf || !buf_len || !res || !is_negative)
461 		return -EINVAL;
462 
463 	if (base != 0 && base != 8 && base != 10 && base != 16)
464 		return -EINVAL;
465 
466 	if (flags & ~BPF_STRTOX_BASE_MASK)
467 		return -EINVAL;
468 
469 	while (cur_buf < buf + buf_len && isspace(*cur_buf))
470 		++cur_buf;
471 
472 	*is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
473 	if (*is_negative)
474 		++cur_buf;
475 
476 	consumed = cur_buf - buf;
477 	cur_len -= consumed;
478 	if (!cur_len)
479 		return -EINVAL;
480 
481 	cur_len = min(cur_len, sizeof(str) - 1);
482 	memcpy(str, cur_buf, cur_len);
483 	str[cur_len] = '\0';
484 	cur_buf = str;
485 
486 	cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
487 	val_len = _parse_integer(cur_buf, base, res);
488 
489 	if (val_len & KSTRTOX_OVERFLOW)
490 		return -ERANGE;
491 
492 	if (val_len == 0)
493 		return -EINVAL;
494 
495 	cur_buf += val_len;
496 	consumed += cur_buf - str;
497 
498 	return consumed;
499 }
500 
501 static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
502 			 long long *res)
503 {
504 	unsigned long long _res;
505 	bool is_negative;
506 	int err;
507 
508 	err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
509 	if (err < 0)
510 		return err;
511 	if (is_negative) {
512 		if ((long long)-_res > 0)
513 			return -ERANGE;
514 		*res = -_res;
515 	} else {
516 		if ((long long)_res < 0)
517 			return -ERANGE;
518 		*res = _res;
519 	}
520 	return err;
521 }
522 
523 BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
524 	   s64 *, res)
525 {
526 	long long _res;
527 	int err;
528 
529 	*res = 0;
530 	err = __bpf_strtoll(buf, buf_len, flags, &_res);
531 	if (err < 0)
532 		return err;
533 	*res = _res;
534 	return err;
535 }
536 
537 const struct bpf_func_proto bpf_strtol_proto = {
538 	.func		= bpf_strtol,
539 	.gpl_only	= false,
540 	.ret_type	= RET_INTEGER,
541 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
542 	.arg2_type	= ARG_CONST_SIZE,
543 	.arg3_type	= ARG_ANYTHING,
544 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
545 	.arg4_size	= sizeof(s64),
546 };
547 
548 BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
549 	   u64 *, res)
550 {
551 	unsigned long long _res;
552 	bool is_negative;
553 	int err;
554 
555 	*res = 0;
556 	err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
557 	if (err < 0)
558 		return err;
559 	if (is_negative)
560 		return -EINVAL;
561 	*res = _res;
562 	return err;
563 }
564 
565 const struct bpf_func_proto bpf_strtoul_proto = {
566 	.func		= bpf_strtoul,
567 	.gpl_only	= false,
568 	.ret_type	= RET_INTEGER,
569 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
570 	.arg2_type	= ARG_CONST_SIZE,
571 	.arg3_type	= ARG_ANYTHING,
572 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
573 	.arg4_size	= sizeof(u64),
574 };
575 
576 BPF_CALL_3(bpf_strncmp, const char *, s1, u32, s1_sz, const char *, s2)
577 {
578 	return strncmp(s1, s2, s1_sz);
579 }
580 
581 static const struct bpf_func_proto bpf_strncmp_proto = {
582 	.func		= bpf_strncmp,
583 	.gpl_only	= false,
584 	.ret_type	= RET_INTEGER,
585 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
586 	.arg2_type	= ARG_CONST_SIZE,
587 	.arg3_type	= ARG_PTR_TO_CONST_STR,
588 };
589 
590 BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
591 	   struct bpf_pidns_info *, nsdata, u32, size)
592 {
593 	struct task_struct *task = current;
594 	struct pid_namespace *pidns;
595 	int err = -EINVAL;
596 
597 	if (unlikely(size != sizeof(struct bpf_pidns_info)))
598 		goto clear;
599 
600 	if (unlikely((u64)(dev_t)dev != dev))
601 		goto clear;
602 
603 	if (unlikely(!task))
604 		goto clear;
605 
606 	pidns = task_active_pid_ns(task);
607 	if (unlikely(!pidns)) {
608 		err = -ENOENT;
609 		goto clear;
610 	}
611 
612 	if (!ns_match(&pidns->ns, (dev_t)dev, ino))
613 		goto clear;
614 
615 	nsdata->pid = task_pid_nr_ns(task, pidns);
616 	nsdata->tgid = task_tgid_nr_ns(task, pidns);
617 	return 0;
618 clear:
619 	memset((void *)nsdata, 0, (size_t) size);
620 	return err;
621 }
622 
623 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
624 	.func		= bpf_get_ns_current_pid_tgid,
625 	.gpl_only	= false,
626 	.ret_type	= RET_INTEGER,
627 	.arg1_type	= ARG_ANYTHING,
628 	.arg2_type	= ARG_ANYTHING,
629 	.arg3_type      = ARG_PTR_TO_UNINIT_MEM,
630 	.arg4_type      = ARG_CONST_SIZE,
631 };
632 
633 static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
634 	.func		= bpf_get_raw_cpu_id,
635 	.gpl_only	= false,
636 	.ret_type	= RET_INTEGER,
637 };
638 
639 BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map,
640 	   u64, flags, void *, data, u64, size)
641 {
642 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
643 		return -EINVAL;
644 
645 	return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
646 }
647 
648 const struct bpf_func_proto bpf_event_output_data_proto =  {
649 	.func		= bpf_event_output_data,
650 	.gpl_only       = true,
651 	.ret_type       = RET_INTEGER,
652 	.arg1_type      = ARG_PTR_TO_CTX,
653 	.arg2_type      = ARG_CONST_MAP_PTR,
654 	.arg3_type      = ARG_ANYTHING,
655 	.arg4_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
656 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
657 };
658 
659 BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size,
660 	   const void __user *, user_ptr)
661 {
662 	int ret = copy_from_user(dst, user_ptr, size);
663 
664 	if (unlikely(ret)) {
665 		memset(dst, 0, size);
666 		ret = -EFAULT;
667 	}
668 
669 	return ret;
670 }
671 
672 const struct bpf_func_proto bpf_copy_from_user_proto = {
673 	.func		= bpf_copy_from_user,
674 	.gpl_only	= false,
675 	.might_sleep	= true,
676 	.ret_type	= RET_INTEGER,
677 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
678 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
679 	.arg3_type	= ARG_ANYTHING,
680 };
681 
682 BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size,
683 	   const void __user *, user_ptr, struct task_struct *, tsk, u64, flags)
684 {
685 	int ret;
686 
687 	/* flags is not used yet */
688 	if (unlikely(flags))
689 		return -EINVAL;
690 
691 	if (unlikely(!size))
692 		return 0;
693 
694 	ret = access_process_vm(tsk, (unsigned long)user_ptr, dst, size, 0);
695 	if (ret == size)
696 		return 0;
697 
698 	memset(dst, 0, size);
699 	/* Return -EFAULT for partial read */
700 	return ret < 0 ? ret : -EFAULT;
701 }
702 
703 const struct bpf_func_proto bpf_copy_from_user_task_proto = {
704 	.func		= bpf_copy_from_user_task,
705 	.gpl_only	= true,
706 	.might_sleep	= true,
707 	.ret_type	= RET_INTEGER,
708 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
709 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
710 	.arg3_type	= ARG_ANYTHING,
711 	.arg4_type	= ARG_PTR_TO_BTF_ID,
712 	.arg4_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
713 	.arg5_type	= ARG_ANYTHING
714 };
715 
716 BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu)
717 {
718 	if (cpu >= nr_cpu_ids)
719 		return (unsigned long)NULL;
720 
721 	return (unsigned long)per_cpu_ptr((const void __percpu *)(const uintptr_t)ptr, cpu);
722 }
723 
724 const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
725 	.func		= bpf_per_cpu_ptr,
726 	.gpl_only	= false,
727 	.ret_type	= RET_PTR_TO_MEM_OR_BTF_ID | PTR_MAYBE_NULL | MEM_RDONLY,
728 	.arg1_type	= ARG_PTR_TO_PERCPU_BTF_ID,
729 	.arg2_type	= ARG_ANYTHING,
730 };
731 
732 BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
733 {
734 	return (unsigned long)this_cpu_ptr((const void __percpu *)(const uintptr_t)percpu_ptr);
735 }
736 
737 const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
738 	.func		= bpf_this_cpu_ptr,
739 	.gpl_only	= false,
740 	.ret_type	= RET_PTR_TO_MEM_OR_BTF_ID | MEM_RDONLY,
741 	.arg1_type	= ARG_PTR_TO_PERCPU_BTF_ID,
742 };
743 
744 static int bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
745 		size_t bufsz)
746 {
747 	void __user *user_ptr = (__force void __user *)unsafe_ptr;
748 
749 	buf[0] = 0;
750 
751 	switch (fmt_ptype) {
752 	case 's':
753 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
754 		if ((unsigned long)unsafe_ptr < TASK_SIZE)
755 			return strncpy_from_user_nofault(buf, user_ptr, bufsz);
756 		fallthrough;
757 #endif
758 	case 'k':
759 		return strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
760 	case 'u':
761 		return strncpy_from_user_nofault(buf, user_ptr, bufsz);
762 	}
763 
764 	return -EINVAL;
765 }
766 
767 /* Support executing three nested bprintf helper calls on a given CPU */
768 #define MAX_BPRINTF_NEST_LEVEL	3
769 
770 static DEFINE_PER_CPU(struct bpf_bprintf_buffers[MAX_BPRINTF_NEST_LEVEL], bpf_bprintf_bufs);
771 static DEFINE_PER_CPU(int, bpf_bprintf_nest_level);
772 
773 int bpf_try_get_buffers(struct bpf_bprintf_buffers **bufs)
774 {
775 	int nest_level;
776 
777 	preempt_disable();
778 	nest_level = this_cpu_inc_return(bpf_bprintf_nest_level);
779 	if (WARN_ON_ONCE(nest_level > MAX_BPRINTF_NEST_LEVEL)) {
780 		this_cpu_dec(bpf_bprintf_nest_level);
781 		preempt_enable();
782 		return -EBUSY;
783 	}
784 	*bufs = this_cpu_ptr(&bpf_bprintf_bufs[nest_level - 1]);
785 
786 	return 0;
787 }
788 
789 void bpf_put_buffers(void)
790 {
791 	if (WARN_ON_ONCE(this_cpu_read(bpf_bprintf_nest_level) == 0))
792 		return;
793 	this_cpu_dec(bpf_bprintf_nest_level);
794 	preempt_enable();
795 }
796 
797 void bpf_bprintf_cleanup(struct bpf_bprintf_data *data)
798 {
799 	if (!data->bin_args && !data->buf)
800 		return;
801 	bpf_put_buffers();
802 }
803 
804 /*
805  * bpf_bprintf_prepare - Generic pass on format strings for bprintf-like helpers
806  *
807  * Returns a negative value if fmt is an invalid format string or 0 otherwise.
808  *
809  * This can be used in two ways:
810  * - Format string verification only: when data->get_bin_args is false
811  * - Arguments preparation: in addition to the above verification, it writes in
812  *   data->bin_args a binary representation of arguments usable by bstr_printf
813  *   where pointers from BPF have been sanitized.
814  *
815  * In argument preparation mode, if 0 is returned, safe temporary buffers are
816  * allocated and bpf_bprintf_cleanup should be called to free them after use.
817  */
818 int bpf_bprintf_prepare(const char *fmt, u32 fmt_size, const u64 *raw_args,
819 			u32 num_args, struct bpf_bprintf_data *data)
820 {
821 	bool get_buffers = (data->get_bin_args && num_args) || data->get_buf;
822 	char *unsafe_ptr = NULL, *tmp_buf = NULL, *tmp_buf_end, *fmt_end;
823 	struct bpf_bprintf_buffers *buffers = NULL;
824 	size_t sizeof_cur_arg, sizeof_cur_ip;
825 	int err, i, num_spec = 0;
826 	u64 cur_arg;
827 	char fmt_ptype, cur_ip[16], ip_spec[] = "%pXX";
828 
829 	fmt_end = strnchr(fmt, fmt_size, 0);
830 	if (!fmt_end)
831 		return -EINVAL;
832 	fmt_size = fmt_end - fmt;
833 
834 	if (get_buffers && bpf_try_get_buffers(&buffers))
835 		return -EBUSY;
836 
837 	if (data->get_bin_args) {
838 		if (num_args)
839 			tmp_buf = buffers->bin_args;
840 		tmp_buf_end = tmp_buf + MAX_BPRINTF_BIN_ARGS;
841 		data->bin_args = (u32 *)tmp_buf;
842 	}
843 
844 	if (data->get_buf)
845 		data->buf = buffers->buf;
846 
847 	for (i = 0; i < fmt_size; i++) {
848 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
849 			err = -EINVAL;
850 			goto out;
851 		}
852 
853 		if (fmt[i] != '%')
854 			continue;
855 
856 		if (fmt[i + 1] == '%') {
857 			i++;
858 			continue;
859 		}
860 
861 		if (num_spec >= num_args) {
862 			err = -EINVAL;
863 			goto out;
864 		}
865 
866 		/* The string is zero-terminated so if fmt[i] != 0, we can
867 		 * always access fmt[i + 1], in the worst case it will be a 0
868 		 */
869 		i++;
870 
871 		/* skip optional "[0 +-][num]" width formatting field */
872 		while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
873 		       fmt[i] == ' ')
874 			i++;
875 		if (fmt[i] >= '1' && fmt[i] <= '9') {
876 			i++;
877 			while (fmt[i] >= '0' && fmt[i] <= '9')
878 				i++;
879 		}
880 
881 		if (fmt[i] == 'p') {
882 			sizeof_cur_arg = sizeof(long);
883 
884 			if (fmt[i + 1] == 0 || isspace(fmt[i + 1]) ||
885 			    ispunct(fmt[i + 1])) {
886 				if (tmp_buf)
887 					cur_arg = raw_args[num_spec];
888 				goto nocopy_fmt;
889 			}
890 
891 			if ((fmt[i + 1] == 'k' || fmt[i + 1] == 'u') &&
892 			    fmt[i + 2] == 's') {
893 				fmt_ptype = fmt[i + 1];
894 				i += 2;
895 				goto fmt_str;
896 			}
897 
898 			if (fmt[i + 1] == 'K' ||
899 			    fmt[i + 1] == 'x' || fmt[i + 1] == 's' ||
900 			    fmt[i + 1] == 'S') {
901 				if (tmp_buf)
902 					cur_arg = raw_args[num_spec];
903 				i++;
904 				goto nocopy_fmt;
905 			}
906 
907 			if (fmt[i + 1] == 'B') {
908 				if (tmp_buf)  {
909 					err = snprintf(tmp_buf,
910 						       (tmp_buf_end - tmp_buf),
911 						       "%pB",
912 						       (void *)(long)raw_args[num_spec]);
913 					tmp_buf += (err + 1);
914 				}
915 
916 				i++;
917 				num_spec++;
918 				continue;
919 			}
920 
921 			/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
922 			if ((fmt[i + 1] != 'i' && fmt[i + 1] != 'I') ||
923 			    (fmt[i + 2] != '4' && fmt[i + 2] != '6')) {
924 				err = -EINVAL;
925 				goto out;
926 			}
927 
928 			i += 2;
929 			if (!tmp_buf)
930 				goto nocopy_fmt;
931 
932 			sizeof_cur_ip = (fmt[i] == '4') ? 4 : 16;
933 			if (tmp_buf_end - tmp_buf < sizeof_cur_ip) {
934 				err = -ENOSPC;
935 				goto out;
936 			}
937 
938 			unsafe_ptr = (char *)(long)raw_args[num_spec];
939 			err = copy_from_kernel_nofault(cur_ip, unsafe_ptr,
940 						       sizeof_cur_ip);
941 			if (err < 0)
942 				memset(cur_ip, 0, sizeof_cur_ip);
943 
944 			/* hack: bstr_printf expects IP addresses to be
945 			 * pre-formatted as strings, ironically, the easiest way
946 			 * to do that is to call snprintf.
947 			 */
948 			ip_spec[2] = fmt[i - 1];
949 			ip_spec[3] = fmt[i];
950 			err = snprintf(tmp_buf, tmp_buf_end - tmp_buf,
951 				       ip_spec, &cur_ip);
952 
953 			tmp_buf += err + 1;
954 			num_spec++;
955 
956 			continue;
957 		} else if (fmt[i] == 's') {
958 			fmt_ptype = fmt[i];
959 fmt_str:
960 			if (fmt[i + 1] != 0 &&
961 			    !isspace(fmt[i + 1]) &&
962 			    !ispunct(fmt[i + 1])) {
963 				err = -EINVAL;
964 				goto out;
965 			}
966 
967 			if (!tmp_buf)
968 				goto nocopy_fmt;
969 
970 			if (tmp_buf_end == tmp_buf) {
971 				err = -ENOSPC;
972 				goto out;
973 			}
974 
975 			unsafe_ptr = (char *)(long)raw_args[num_spec];
976 			err = bpf_trace_copy_string(tmp_buf, unsafe_ptr,
977 						    fmt_ptype,
978 						    tmp_buf_end - tmp_buf);
979 			if (err < 0) {
980 				tmp_buf[0] = '\0';
981 				err = 1;
982 			}
983 
984 			tmp_buf += err;
985 			num_spec++;
986 
987 			continue;
988 		} else if (fmt[i] == 'c') {
989 			if (!tmp_buf)
990 				goto nocopy_fmt;
991 
992 			if (tmp_buf_end == tmp_buf) {
993 				err = -ENOSPC;
994 				goto out;
995 			}
996 
997 			*tmp_buf = raw_args[num_spec];
998 			tmp_buf++;
999 			num_spec++;
1000 
1001 			continue;
1002 		}
1003 
1004 		sizeof_cur_arg = sizeof(int);
1005 
1006 		if (fmt[i] == 'l') {
1007 			sizeof_cur_arg = sizeof(long);
1008 			i++;
1009 		}
1010 		if (fmt[i] == 'l') {
1011 			sizeof_cur_arg = sizeof(long long);
1012 			i++;
1013 		}
1014 
1015 		if (fmt[i] != 'i' && fmt[i] != 'd' && fmt[i] != 'u' &&
1016 		    fmt[i] != 'x' && fmt[i] != 'X') {
1017 			err = -EINVAL;
1018 			goto out;
1019 		}
1020 
1021 		if (tmp_buf)
1022 			cur_arg = raw_args[num_spec];
1023 nocopy_fmt:
1024 		if (tmp_buf) {
1025 			tmp_buf = PTR_ALIGN(tmp_buf, sizeof(u32));
1026 			if (tmp_buf_end - tmp_buf < sizeof_cur_arg) {
1027 				err = -ENOSPC;
1028 				goto out;
1029 			}
1030 
1031 			if (sizeof_cur_arg == 8) {
1032 				*(u32 *)tmp_buf = *(u32 *)&cur_arg;
1033 				*(u32 *)(tmp_buf + 4) = *((u32 *)&cur_arg + 1);
1034 			} else {
1035 				*(u32 *)tmp_buf = (u32)(long)cur_arg;
1036 			}
1037 			tmp_buf += sizeof_cur_arg;
1038 		}
1039 		num_spec++;
1040 	}
1041 
1042 	err = 0;
1043 out:
1044 	if (err)
1045 		bpf_bprintf_cleanup(data);
1046 	return err;
1047 }
1048 
1049 BPF_CALL_5(bpf_snprintf, char *, str, u32, str_size, char *, fmt,
1050 	   const void *, args, u32, data_len)
1051 {
1052 	struct bpf_bprintf_data data = {
1053 		.get_bin_args	= true,
1054 	};
1055 	int err, num_args;
1056 
1057 	if (data_len % 8 || data_len > MAX_BPRINTF_VARARGS * 8 ||
1058 	    (data_len && !args))
1059 		return -EINVAL;
1060 	num_args = data_len / 8;
1061 
1062 	/* ARG_PTR_TO_CONST_STR guarantees that fmt is zero-terminated so we
1063 	 * can safely give an unbounded size.
1064 	 */
1065 	err = bpf_bprintf_prepare(fmt, UINT_MAX, args, num_args, &data);
1066 	if (err < 0)
1067 		return err;
1068 
1069 	err = bstr_printf(str, str_size, fmt, data.bin_args);
1070 
1071 	bpf_bprintf_cleanup(&data);
1072 
1073 	return err + 1;
1074 }
1075 
1076 const struct bpf_func_proto bpf_snprintf_proto = {
1077 	.func		= bpf_snprintf,
1078 	.gpl_only	= true,
1079 	.ret_type	= RET_INTEGER,
1080 	.arg1_type	= ARG_PTR_TO_MEM_OR_NULL | MEM_WRITE,
1081 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1082 	.arg3_type	= ARG_PTR_TO_CONST_STR,
1083 	.arg4_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
1084 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1085 };
1086 
1087 static void *map_key_from_value(struct bpf_map *map, void *value, u32 *arr_idx)
1088 {
1089 	if (map->map_type == BPF_MAP_TYPE_ARRAY) {
1090 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1091 
1092 		*arr_idx = ((char *)value - array->value) / array->elem_size;
1093 		return arr_idx;
1094 	}
1095 	return (void *)value - round_up(map->key_size, 8);
1096 }
1097 
1098 enum bpf_async_type {
1099 	BPF_ASYNC_TYPE_TIMER = 0,
1100 	BPF_ASYNC_TYPE_WQ,
1101 };
1102 
1103 enum bpf_async_op {
1104 	BPF_ASYNC_START,
1105 	BPF_ASYNC_CANCEL
1106 };
1107 
1108 struct bpf_async_cmd {
1109 	struct llist_node node;
1110 	u64 nsec;
1111 	u32 mode;
1112 	enum bpf_async_op op;
1113 };
1114 
1115 struct bpf_async_cb {
1116 	struct bpf_map *map;
1117 	struct bpf_prog *prog;
1118 	void __rcu *callback_fn;
1119 	void *value;
1120 	struct rcu_head rcu;
1121 	u64 flags;
1122 	struct irq_work worker;
1123 	refcount_t refcnt;
1124 	enum bpf_async_type type;
1125 	struct llist_head async_cmds;
1126 };
1127 
1128 /* BPF map elements can contain 'struct bpf_timer'.
1129  * Such map owns all of its BPF timers.
1130  * 'struct bpf_timer' is allocated as part of map element allocation
1131  * and it's zero initialized.
1132  * That space is used to keep 'struct bpf_async_kern'.
1133  * bpf_timer_init() allocates 'struct bpf_hrtimer', inits hrtimer, and
1134  * remembers 'struct bpf_map *' pointer it's part of.
1135  * bpf_timer_set_callback() increments prog refcnt and assign bpf callback_fn.
1136  * bpf_timer_start() arms the timer.
1137  * If user space reference to a map goes to zero at this point
1138  * ops->map_release_uref callback is responsible for cancelling the timers,
1139  * freeing their memory, and decrementing prog's refcnts.
1140  * bpf_timer_cancel() cancels the timer and decrements prog's refcnt.
1141  * Inner maps can contain bpf timers as well. ops->map_release_uref is
1142  * freeing the timers when inner map is replaced or deleted by user space.
1143  */
1144 struct bpf_hrtimer {
1145 	struct bpf_async_cb cb;
1146 	struct hrtimer timer;
1147 	atomic_t cancelling;
1148 };
1149 
1150 struct bpf_work {
1151 	struct bpf_async_cb cb;
1152 	struct work_struct work;
1153 };
1154 
1155 /* the actual struct hidden inside uapi struct bpf_timer and bpf_wq */
1156 struct bpf_async_kern {
1157 	union {
1158 		struct bpf_async_cb *cb;
1159 		struct bpf_hrtimer *timer;
1160 		struct bpf_work *work;
1161 	};
1162 } __attribute__((aligned(8)));
1163 
1164 static DEFINE_PER_CPU(struct bpf_hrtimer *, hrtimer_running);
1165 
1166 static void bpf_async_refcount_put(struct bpf_async_cb *cb);
1167 
1168 static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer)
1169 {
1170 	struct bpf_hrtimer *t = container_of(hrtimer, struct bpf_hrtimer, timer);
1171 	struct bpf_map *map = t->cb.map;
1172 	void *value = t->cb.value;
1173 	bpf_callback_t callback_fn;
1174 	void *key;
1175 	u32 idx;
1176 
1177 	BTF_TYPE_EMIT(struct bpf_timer);
1178 	callback_fn = rcu_dereference_check(t->cb.callback_fn, rcu_read_lock_bh_held());
1179 	if (!callback_fn)
1180 		goto out;
1181 
1182 	/* bpf_timer_cb() runs in hrtimer_run_softirq. It doesn't migrate and
1183 	 * cannot be preempted by another bpf_timer_cb() on the same cpu.
1184 	 * Remember the timer this callback is servicing to prevent
1185 	 * deadlock if callback_fn() calls bpf_timer_cancel() or
1186 	 * bpf_map_delete_elem() on the same timer.
1187 	 */
1188 	this_cpu_write(hrtimer_running, t);
1189 
1190 	key = map_key_from_value(map, value, &idx);
1191 
1192 	callback_fn((u64)(long)map, (u64)(long)key, (u64)(long)value, 0, 0);
1193 	/* The verifier checked that return value is zero. */
1194 
1195 	this_cpu_write(hrtimer_running, NULL);
1196 out:
1197 	return HRTIMER_NORESTART;
1198 }
1199 
1200 static void bpf_wq_work(struct work_struct *work)
1201 {
1202 	struct bpf_work *w = container_of(work, struct bpf_work, work);
1203 	struct bpf_async_cb *cb = &w->cb;
1204 	struct bpf_map *map = cb->map;
1205 	bpf_callback_t callback_fn;
1206 	void *value = cb->value;
1207 	void *key;
1208 	u32 idx;
1209 
1210 	BTF_TYPE_EMIT(struct bpf_wq);
1211 
1212 	callback_fn = READ_ONCE(cb->callback_fn);
1213 	if (!callback_fn)
1214 		return;
1215 
1216 	key = map_key_from_value(map, value, &idx);
1217 
1218         rcu_read_lock_trace();
1219         migrate_disable();
1220 
1221 	callback_fn((u64)(long)map, (u64)(long)key, (u64)(long)value, 0, 0);
1222 
1223 	migrate_enable();
1224 	rcu_read_unlock_trace();
1225 }
1226 
1227 static void bpf_async_cb_rcu_free(struct rcu_head *rcu)
1228 {
1229 	struct bpf_async_cb *cb = container_of(rcu, struct bpf_async_cb, rcu);
1230 
1231 	/*
1232 	 * Drop the last reference to prog only after RCU GP, as set_callback()
1233 	 * may race with cancel_and_free()
1234 	 */
1235 	if (cb->prog)
1236 		bpf_prog_put(cb->prog);
1237 
1238 	kfree_nolock(cb);
1239 }
1240 
1241 /* Callback from call_rcu_tasks_trace, chains to call_rcu for final free */
1242 static void bpf_async_cb_rcu_tasks_trace_free(struct rcu_head *rcu)
1243 {
1244 	struct bpf_async_cb *cb = container_of(rcu, struct bpf_async_cb, rcu);
1245 	struct bpf_hrtimer *t = container_of(cb, struct bpf_hrtimer, cb);
1246 	struct bpf_work *w = container_of(cb, struct bpf_work, cb);
1247 	bool retry = false;
1248 
1249 	/*
1250 	 * bpf_async_cancel_and_free() tried to cancel timer/wq, but it
1251 	 * could have raced with timer/wq_start. Now refcnt is zero and
1252 	 * srcu/rcu GP completed. Cancel timer/wq again.
1253 	 */
1254 	switch (cb->type) {
1255 	case BPF_ASYNC_TYPE_TIMER:
1256 		if (hrtimer_try_to_cancel(&t->timer) < 0)
1257 			retry = true;
1258 		break;
1259 	case BPF_ASYNC_TYPE_WQ:
1260 		if (!cancel_work(&w->work) && work_busy(&w->work))
1261 			retry = true;
1262 		break;
1263 	}
1264 	if (retry) {
1265 		/*
1266 		 * hrtimer or wq callback may still be running. It must be
1267 		 * in rcu_tasks_trace or rcu CS, so wait for GP again.
1268 		 * It won't retry forever, since refcnt zero prevents all
1269 		 * operations on timer/wq.
1270 		 */
1271 		call_rcu_tasks_trace(&cb->rcu, bpf_async_cb_rcu_tasks_trace_free);
1272 		return;
1273 	}
1274 
1275 	/* rcu_trace_implies_rcu_gp() is true and will remain so */
1276 	bpf_async_cb_rcu_free(rcu);
1277 }
1278 
1279 static void worker_for_call_rcu(struct irq_work *work)
1280 {
1281 	struct bpf_async_cb *cb = container_of(work, struct bpf_async_cb, worker);
1282 
1283 	call_rcu_tasks_trace(&cb->rcu, bpf_async_cb_rcu_tasks_trace_free);
1284 }
1285 
1286 static void bpf_async_refcount_put(struct bpf_async_cb *cb)
1287 {
1288 	if (!refcount_dec_and_test(&cb->refcnt))
1289 		return;
1290 
1291 	if (irqs_disabled()) {
1292 		cb->worker = IRQ_WORK_INIT(worker_for_call_rcu);
1293 		irq_work_queue(&cb->worker);
1294 	} else {
1295 		call_rcu_tasks_trace(&cb->rcu, bpf_async_cb_rcu_tasks_trace_free);
1296 	}
1297 }
1298 
1299 static void bpf_async_cancel_and_free(struct bpf_async_kern *async);
1300 static void bpf_async_irq_worker(struct irq_work *work);
1301 
1302 static int __bpf_async_init(struct bpf_async_kern *async, struct bpf_map *map, u64 flags,
1303 			    enum bpf_async_type type)
1304 {
1305 	struct bpf_async_cb *cb, *old_cb;
1306 	struct bpf_hrtimer *t;
1307 	struct bpf_work *w;
1308 	clockid_t clockid;
1309 	size_t size;
1310 
1311 	switch (type) {
1312 	case BPF_ASYNC_TYPE_TIMER:
1313 		size = sizeof(struct bpf_hrtimer);
1314 		break;
1315 	case BPF_ASYNC_TYPE_WQ:
1316 		size = sizeof(struct bpf_work);
1317 		break;
1318 	default:
1319 		return -EINVAL;
1320 	}
1321 
1322 	old_cb = READ_ONCE(async->cb);
1323 	if (old_cb)
1324 		return -EBUSY;
1325 
1326 	cb = bpf_map_kmalloc_nolock(map, size, 0, map->numa_node);
1327 	if (!cb)
1328 		return -ENOMEM;
1329 
1330 	switch (type) {
1331 	case BPF_ASYNC_TYPE_TIMER:
1332 		clockid = flags & (MAX_CLOCKS - 1);
1333 		t = (struct bpf_hrtimer *)cb;
1334 
1335 		atomic_set(&t->cancelling, 0);
1336 		hrtimer_setup(&t->timer, bpf_timer_cb, clockid, HRTIMER_MODE_REL_SOFT);
1337 		cb->value = (void *)async - map->record->timer_off;
1338 		break;
1339 	case BPF_ASYNC_TYPE_WQ:
1340 		w = (struct bpf_work *)cb;
1341 
1342 		INIT_WORK(&w->work, bpf_wq_work);
1343 		cb->value = (void *)async - map->record->wq_off;
1344 		break;
1345 	}
1346 	cb->map = map;
1347 	cb->prog = NULL;
1348 	cb->flags = flags;
1349 	cb->worker = IRQ_WORK_INIT(bpf_async_irq_worker);
1350 	init_llist_head(&cb->async_cmds);
1351 	refcount_set(&cb->refcnt, 1); /* map's reference */
1352 	cb->type = type;
1353 	rcu_assign_pointer(cb->callback_fn, NULL);
1354 
1355 	old_cb = cmpxchg(&async->cb, NULL, cb);
1356 	if (old_cb) {
1357 		/* Lost the race to initialize this bpf_async_kern, drop the allocated object */
1358 		kfree_nolock(cb);
1359 		return -EBUSY;
1360 	}
1361 	/* Guarantee the order between async->cb and map->usercnt. So
1362 	 * when there are concurrent uref release and bpf timer init, either
1363 	 * bpf_timer_cancel_and_free() called by uref release reads a no-NULL
1364 	 * timer or atomic64_read() below returns a zero usercnt.
1365 	 */
1366 	smp_mb();
1367 	if (!atomic64_read(&map->usercnt)) {
1368 		/* maps with timers must be either held by user space
1369 		 * or pinned in bpffs.
1370 		 */
1371 		bpf_async_cancel_and_free(async);
1372 		return -EPERM;
1373 	}
1374 
1375 	return 0;
1376 }
1377 
1378 BPF_CALL_3(bpf_timer_init, struct bpf_async_kern *, timer, struct bpf_map *, map,
1379 	   u64, flags)
1380 {
1381 	clock_t clockid = flags & (MAX_CLOCKS - 1);
1382 
1383 	BUILD_BUG_ON(MAX_CLOCKS != 16);
1384 	BUILD_BUG_ON(sizeof(struct bpf_async_kern) > sizeof(struct bpf_timer));
1385 	BUILD_BUG_ON(__alignof__(struct bpf_async_kern) != __alignof__(struct bpf_timer));
1386 
1387 	if (flags >= MAX_CLOCKS ||
1388 	    /* similar to timerfd except _ALARM variants are not supported */
1389 	    (clockid != CLOCK_MONOTONIC &&
1390 	     clockid != CLOCK_REALTIME &&
1391 	     clockid != CLOCK_BOOTTIME))
1392 		return -EINVAL;
1393 
1394 	return __bpf_async_init(timer, map, flags, BPF_ASYNC_TYPE_TIMER);
1395 }
1396 
1397 static const struct bpf_func_proto bpf_timer_init_proto = {
1398 	.func		= bpf_timer_init,
1399 	.gpl_only	= true,
1400 	.ret_type	= RET_INTEGER,
1401 	.arg1_type	= ARG_PTR_TO_TIMER,
1402 	.arg2_type	= ARG_CONST_MAP_PTR,
1403 	.arg3_type	= ARG_ANYTHING,
1404 };
1405 
1406 static int bpf_async_update_prog_callback(struct bpf_async_cb *cb,
1407 					  struct bpf_prog *prog,
1408 					  void *callback_fn)
1409 {
1410 	struct bpf_prog *prev;
1411 
1412 	/* Acquire a guard reference on prog to prevent it from being freed during the loop */
1413 	if (prog) {
1414 		prog = bpf_prog_inc_not_zero(prog);
1415 		if (IS_ERR(prog))
1416 			return PTR_ERR(prog);
1417 	}
1418 
1419 	do {
1420 		if (prog)
1421 			prog = bpf_prog_inc_not_zero(prog);
1422 		prev = xchg(&cb->prog, prog);
1423 		rcu_assign_pointer(cb->callback_fn, callback_fn);
1424 
1425 		/*
1426 		 * Release previous prog, make sure that if other CPU is contending,
1427 		 * to set bpf_prog, references are not leaked as each iteration acquires and
1428 		 * releases one reference.
1429 		 */
1430 		if (prev)
1431 			bpf_prog_put(prev);
1432 
1433 	} while (READ_ONCE(cb->prog) != prog ||
1434 		 (void __force *)READ_ONCE(cb->callback_fn) != callback_fn);
1435 
1436 	if (prog)
1437 		bpf_prog_put(prog);
1438 
1439 	return 0;
1440 }
1441 
1442 static DEFINE_PER_CPU(struct bpf_async_cb *, async_cb_running);
1443 
1444 static int bpf_async_schedule_op(struct bpf_async_cb *cb, enum bpf_async_op op,
1445 				 u64 nsec, u32 timer_mode)
1446 {
1447 	/*
1448 	 * Do not schedule another operation on this cpu if it's in irq_work
1449 	 * callback that is processing async_cmds queue. Otherwise the following
1450 	 * loop is possible:
1451 	 * bpf_timer_start() -> bpf_async_schedule_op() -> irq_work_queue().
1452 	 * irqrestore -> bpf_async_irq_worker() -> tracepoint -> bpf_timer_start().
1453 	 */
1454 	if (this_cpu_read(async_cb_running) == cb) {
1455 		bpf_async_refcount_put(cb);
1456 		return -EDEADLK;
1457 	}
1458 
1459 	struct bpf_async_cmd *cmd = kmalloc_nolock(sizeof(*cmd), 0, NUMA_NO_NODE);
1460 
1461 	if (!cmd) {
1462 		bpf_async_refcount_put(cb);
1463 		return -ENOMEM;
1464 	}
1465 	init_llist_node(&cmd->node);
1466 	cmd->nsec = nsec;
1467 	cmd->mode = timer_mode;
1468 	cmd->op = op;
1469 	if (llist_add(&cmd->node, &cb->async_cmds))
1470 		irq_work_queue(&cb->worker);
1471 	return 0;
1472 }
1473 
1474 static int __bpf_async_set_callback(struct bpf_async_kern *async, void *callback_fn,
1475 				    struct bpf_prog *prog)
1476 {
1477 	struct bpf_async_cb *cb;
1478 
1479 	cb = READ_ONCE(async->cb);
1480 	if (!cb)
1481 		return -EINVAL;
1482 
1483 	return bpf_async_update_prog_callback(cb, prog, callback_fn);
1484 }
1485 
1486 BPF_CALL_3(bpf_timer_set_callback, struct bpf_async_kern *, timer, void *, callback_fn,
1487 	   struct bpf_prog_aux *, aux)
1488 {
1489 	return __bpf_async_set_callback(timer, callback_fn, aux->prog);
1490 }
1491 
1492 static const struct bpf_func_proto bpf_timer_set_callback_proto = {
1493 	.func		= bpf_timer_set_callback,
1494 	.gpl_only	= true,
1495 	.ret_type	= RET_INTEGER,
1496 	.arg1_type	= ARG_PTR_TO_TIMER,
1497 	.arg2_type	= ARG_PTR_TO_FUNC,
1498 };
1499 
1500 static bool defer_timer_wq_op(void)
1501 {
1502 	return in_hardirq() || irqs_disabled();
1503 }
1504 
1505 BPF_CALL_3(bpf_timer_start, struct bpf_async_kern *, async, u64, nsecs, u64, flags)
1506 {
1507 	struct bpf_hrtimer *t;
1508 	u32 mode;
1509 
1510 	if (flags & ~(BPF_F_TIMER_ABS | BPF_F_TIMER_CPU_PIN))
1511 		return -EINVAL;
1512 
1513 	t = READ_ONCE(async->timer);
1514 	if (!t || !READ_ONCE(t->cb.prog))
1515 		return -EINVAL;
1516 
1517 	if (flags & BPF_F_TIMER_ABS)
1518 		mode = HRTIMER_MODE_ABS_SOFT;
1519 	else
1520 		mode = HRTIMER_MODE_REL_SOFT;
1521 
1522 	if (flags & BPF_F_TIMER_CPU_PIN)
1523 		mode |= HRTIMER_MODE_PINNED;
1524 
1525 	/*
1526 	 * bpf_async_cancel_and_free() could have dropped refcnt to zero. In
1527 	 * such case BPF progs are not allowed to arm the timer to prevent UAF.
1528 	 */
1529 	if (!refcount_inc_not_zero(&t->cb.refcnt))
1530 		return -ENOENT;
1531 
1532 	if (!defer_timer_wq_op()) {
1533 		hrtimer_start(&t->timer, ns_to_ktime(nsecs), mode);
1534 		bpf_async_refcount_put(&t->cb);
1535 		return 0;
1536 	} else {
1537 		return bpf_async_schedule_op(&t->cb, BPF_ASYNC_START, nsecs, mode);
1538 	}
1539 }
1540 
1541 static const struct bpf_func_proto bpf_timer_start_proto = {
1542 	.func		= bpf_timer_start,
1543 	.gpl_only	= true,
1544 	.ret_type	= RET_INTEGER,
1545 	.arg1_type	= ARG_PTR_TO_TIMER,
1546 	.arg2_type	= ARG_ANYTHING,
1547 	.arg3_type	= ARG_ANYTHING,
1548 };
1549 
1550 BPF_CALL_1(bpf_timer_cancel, struct bpf_async_kern *, async)
1551 {
1552 	struct bpf_hrtimer *t, *cur_t;
1553 	bool inc = false;
1554 	int ret = 0;
1555 
1556 	if (defer_timer_wq_op())
1557 		return -EOPNOTSUPP;
1558 
1559 	t = READ_ONCE(async->timer);
1560 	if (!t)
1561 		return -EINVAL;
1562 
1563 	cur_t = this_cpu_read(hrtimer_running);
1564 	if (cur_t == t) {
1565 		/* If bpf callback_fn is trying to bpf_timer_cancel()
1566 		 * its own timer the hrtimer_cancel() will deadlock
1567 		 * since it waits for callback_fn to finish.
1568 		 */
1569 		return -EDEADLK;
1570 	}
1571 
1572 	/* Only account in-flight cancellations when invoked from a timer
1573 	 * callback, since we want to avoid waiting only if other _callbacks_
1574 	 * are waiting on us, to avoid introducing lockups. Non-callback paths
1575 	 * are ok, since nobody would synchronously wait for their completion.
1576 	 */
1577 	if (!cur_t)
1578 		goto drop;
1579 	atomic_inc(&t->cancelling);
1580 	/* Need full barrier after relaxed atomic_inc */
1581 	smp_mb__after_atomic();
1582 	inc = true;
1583 	if (atomic_read(&cur_t->cancelling)) {
1584 		/* We're cancelling timer t, while some other timer callback is
1585 		 * attempting to cancel us. In such a case, it might be possible
1586 		 * that timer t belongs to the other callback, or some other
1587 		 * callback waiting upon it (creating transitive dependencies
1588 		 * upon us), and we will enter a deadlock if we continue
1589 		 * cancelling and waiting for it synchronously, since it might
1590 		 * do the same. Bail!
1591 		 */
1592 		atomic_dec(&t->cancelling);
1593 		return -EDEADLK;
1594 	}
1595 drop:
1596 	bpf_async_update_prog_callback(&t->cb, NULL, NULL);
1597 	/* Cancel the timer and wait for associated callback to finish
1598 	 * if it was running.
1599 	 */
1600 	ret = hrtimer_cancel(&t->timer);
1601 	if (inc)
1602 		atomic_dec(&t->cancelling);
1603 	return ret;
1604 }
1605 
1606 static const struct bpf_func_proto bpf_timer_cancel_proto = {
1607 	.func		= bpf_timer_cancel,
1608 	.gpl_only	= true,
1609 	.ret_type	= RET_INTEGER,
1610 	.arg1_type	= ARG_PTR_TO_TIMER,
1611 };
1612 
1613 static void bpf_async_process_op(struct bpf_async_cb *cb, u32 op,
1614 				 u64 timer_nsec, u32 timer_mode)
1615 {
1616 	switch (cb->type) {
1617 	case BPF_ASYNC_TYPE_TIMER: {
1618 		struct bpf_hrtimer *t = container_of(cb, struct bpf_hrtimer, cb);
1619 
1620 		switch (op) {
1621 		case BPF_ASYNC_START:
1622 			hrtimer_start(&t->timer, ns_to_ktime(timer_nsec), timer_mode);
1623 			break;
1624 		case BPF_ASYNC_CANCEL:
1625 			hrtimer_try_to_cancel(&t->timer);
1626 			break;
1627 		}
1628 		break;
1629 	}
1630 	case BPF_ASYNC_TYPE_WQ: {
1631 		struct bpf_work *w = container_of(cb, struct bpf_work, cb);
1632 
1633 		switch (op) {
1634 		case BPF_ASYNC_START:
1635 			schedule_work(&w->work);
1636 			break;
1637 		case BPF_ASYNC_CANCEL:
1638 			cancel_work(&w->work);
1639 			break;
1640 		}
1641 		break;
1642 	}
1643 	}
1644 	bpf_async_refcount_put(cb);
1645 }
1646 
1647 static void bpf_async_irq_worker(struct irq_work *work)
1648 {
1649 	struct bpf_async_cb *cb = container_of(work, struct bpf_async_cb, worker);
1650 	struct llist_node *pos, *n, *list;
1651 
1652 	list = llist_del_all(&cb->async_cmds);
1653 	if (!list)
1654 		return;
1655 
1656 	list = llist_reverse_order(list);
1657 	this_cpu_write(async_cb_running, cb);
1658 	llist_for_each_safe(pos, n, list) {
1659 		struct bpf_async_cmd *cmd;
1660 
1661 		cmd = container_of(pos, struct bpf_async_cmd, node);
1662 		bpf_async_process_op(cb, cmd->op, cmd->nsec, cmd->mode);
1663 		kfree_nolock(cmd);
1664 	}
1665 	this_cpu_write(async_cb_running, NULL);
1666 }
1667 
1668 static void bpf_async_cancel_and_free(struct bpf_async_kern *async)
1669 {
1670 	struct bpf_async_cb *cb;
1671 
1672 	if (!READ_ONCE(async->cb))
1673 		return;
1674 
1675 	cb = xchg(&async->cb, NULL);
1676 	if (!cb)
1677 		return;
1678 
1679 	bpf_async_update_prog_callback(cb, NULL, NULL);
1680 	/*
1681 	 * No refcount_inc_not_zero(&cb->refcnt) here. Dropping the last
1682 	 * refcnt. Either synchronously or asynchronously in irq_work.
1683 	 */
1684 
1685 	if (!defer_timer_wq_op()) {
1686 		bpf_async_process_op(cb, BPF_ASYNC_CANCEL, 0, 0);
1687 	} else {
1688 		(void)bpf_async_schedule_op(cb, BPF_ASYNC_CANCEL, 0, 0);
1689 		/*
1690 		 * bpf_async_schedule_op() either enqueues allocated cmd into llist
1691 		 * or fails with ENOMEM and drop the last refcnt.
1692 		 * This is unlikely, but safe, since bpf_async_cb_rcu_tasks_trace_free()
1693 		 * callback will do additional timer/wq_cancel due to races anyway.
1694 		 */
1695 	}
1696 }
1697 
1698 /*
1699  * This function is called by map_delete/update_elem for individual element and
1700  * by ops->map_release_uref when the user space reference to a map reaches zero.
1701  */
1702 void bpf_timer_cancel_and_free(void *val)
1703 {
1704 	bpf_async_cancel_and_free(val);
1705 }
1706 
1707 /*
1708  * This function is called by map_delete/update_elem for individual element and
1709  * by ops->map_release_uref when the user space reference to a map reaches zero.
1710  */
1711 void bpf_wq_cancel_and_free(void *val)
1712 {
1713 	bpf_async_cancel_and_free(val);
1714 }
1715 
1716 BPF_CALL_2(bpf_kptr_xchg, void *, dst, void *, ptr)
1717 {
1718 	unsigned long *kptr = dst;
1719 
1720 	/* This helper may be inlined by verifier. */
1721 	return xchg(kptr, (unsigned long)ptr);
1722 }
1723 
1724 /* Unlike other PTR_TO_BTF_ID helpers the btf_id in bpf_kptr_xchg()
1725  * helper is determined dynamically by the verifier. Use BPF_PTR_POISON to
1726  * denote type that verifier will determine.
1727  */
1728 static const struct bpf_func_proto bpf_kptr_xchg_proto = {
1729 	.func         = bpf_kptr_xchg,
1730 	.gpl_only     = false,
1731 	.ret_type     = RET_PTR_TO_BTF_ID_OR_NULL,
1732 	.ret_btf_id   = BPF_PTR_POISON,
1733 	.arg1_type    = ARG_KPTR_XCHG_DEST,
1734 	.arg2_type    = ARG_PTR_TO_BTF_ID_OR_NULL | OBJ_RELEASE,
1735 	.arg2_btf_id  = BPF_PTR_POISON,
1736 };
1737 
1738 struct bpf_dynptr_file_impl {
1739 	struct freader freader;
1740 	/* 64 bit offset and size overriding 32 bit ones in bpf_dynptr_kern */
1741 	u64 offset;
1742 	u64 size;
1743 };
1744 
1745 /* Since the upper 8 bits of dynptr->size is reserved, the
1746  * maximum supported size is 2^24 - 1.
1747  */
1748 #define DYNPTR_MAX_SIZE	((1UL << 24) - 1)
1749 #define DYNPTR_TYPE_SHIFT	28
1750 #define DYNPTR_SIZE_MASK	0xFFFFFF
1751 #define DYNPTR_RDONLY_BIT	BIT(31)
1752 
1753 bool __bpf_dynptr_is_rdonly(const struct bpf_dynptr_kern *ptr)
1754 {
1755 	return ptr->size & DYNPTR_RDONLY_BIT;
1756 }
1757 
1758 void bpf_dynptr_set_rdonly(struct bpf_dynptr_kern *ptr)
1759 {
1760 	ptr->size |= DYNPTR_RDONLY_BIT;
1761 }
1762 
1763 static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_type type)
1764 {
1765 	ptr->size |= type << DYNPTR_TYPE_SHIFT;
1766 }
1767 
1768 static enum bpf_dynptr_type bpf_dynptr_get_type(const struct bpf_dynptr_kern *ptr)
1769 {
1770 	return (ptr->size & ~(DYNPTR_RDONLY_BIT)) >> DYNPTR_TYPE_SHIFT;
1771 }
1772 
1773 u64 __bpf_dynptr_size(const struct bpf_dynptr_kern *ptr)
1774 {
1775 	if (bpf_dynptr_get_type(ptr) == BPF_DYNPTR_TYPE_FILE) {
1776 		struct bpf_dynptr_file_impl *df = ptr->data;
1777 
1778 		return df->size;
1779 	}
1780 
1781 	return ptr->size & DYNPTR_SIZE_MASK;
1782 }
1783 
1784 static void bpf_dynptr_advance_offset(struct bpf_dynptr_kern *ptr, u64 off)
1785 {
1786 	if (bpf_dynptr_get_type(ptr) == BPF_DYNPTR_TYPE_FILE) {
1787 		struct bpf_dynptr_file_impl *df = ptr->data;
1788 
1789 		df->offset += off;
1790 		return;
1791 	}
1792 	ptr->offset += off;
1793 }
1794 
1795 static void bpf_dynptr_set_size(struct bpf_dynptr_kern *ptr, u64 new_size)
1796 {
1797 	u32 metadata = ptr->size & ~DYNPTR_SIZE_MASK;
1798 
1799 	if (bpf_dynptr_get_type(ptr) == BPF_DYNPTR_TYPE_FILE) {
1800 		struct bpf_dynptr_file_impl *df = ptr->data;
1801 
1802 		df->size = new_size;
1803 		return;
1804 	}
1805 	ptr->size = (u32)new_size | metadata;
1806 }
1807 
1808 int bpf_dynptr_check_size(u64 size)
1809 {
1810 	return size > DYNPTR_MAX_SIZE ? -E2BIG : 0;
1811 }
1812 
1813 static int bpf_file_fetch_bytes(struct bpf_dynptr_file_impl *df, u64 offset, void *buf, u64 len)
1814 {
1815 	const void *ptr;
1816 
1817 	if (!buf)
1818 		return -EINVAL;
1819 
1820 	df->freader.buf = buf;
1821 	df->freader.buf_sz = len;
1822 	ptr = freader_fetch(&df->freader, offset + df->offset, len);
1823 	if (!ptr)
1824 		return df->freader.err;
1825 
1826 	if (ptr != buf) /* Force copying into the buffer */
1827 		memcpy(buf, ptr, len);
1828 
1829 	return 0;
1830 }
1831 
1832 void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
1833 		     enum bpf_dynptr_type type, u32 offset, u32 size)
1834 {
1835 	ptr->data = data;
1836 	ptr->offset = offset;
1837 	ptr->size = size;
1838 	bpf_dynptr_set_type(ptr, type);
1839 }
1840 
1841 void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr)
1842 {
1843 	memset(ptr, 0, sizeof(*ptr));
1844 }
1845 
1846 BPF_CALL_4(bpf_dynptr_from_mem, void *, data, u64, size, u64, flags, struct bpf_dynptr_kern *, ptr)
1847 {
1848 	int err;
1849 
1850 	BTF_TYPE_EMIT(struct bpf_dynptr);
1851 
1852 	err = bpf_dynptr_check_size(size);
1853 	if (err)
1854 		goto error;
1855 
1856 	/* flags is currently unsupported */
1857 	if (flags) {
1858 		err = -EINVAL;
1859 		goto error;
1860 	}
1861 
1862 	bpf_dynptr_init(ptr, data, BPF_DYNPTR_TYPE_LOCAL, 0, size);
1863 
1864 	return 0;
1865 
1866 error:
1867 	bpf_dynptr_set_null(ptr);
1868 	return err;
1869 }
1870 
1871 static const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
1872 	.func		= bpf_dynptr_from_mem,
1873 	.gpl_only	= false,
1874 	.ret_type	= RET_INTEGER,
1875 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1876 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1877 	.arg3_type	= ARG_ANYTHING,
1878 	.arg4_type	= ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL | MEM_UNINIT | MEM_WRITE,
1879 };
1880 
1881 static int __bpf_dynptr_read(void *dst, u64 len, const struct bpf_dynptr_kern *src,
1882 			     u64 offset, u64 flags)
1883 {
1884 	enum bpf_dynptr_type type;
1885 	int err;
1886 
1887 	if (!src->data || flags)
1888 		return -EINVAL;
1889 
1890 	err = bpf_dynptr_check_off_len(src, offset, len);
1891 	if (err)
1892 		return err;
1893 
1894 	type = bpf_dynptr_get_type(src);
1895 
1896 	switch (type) {
1897 	case BPF_DYNPTR_TYPE_LOCAL:
1898 	case BPF_DYNPTR_TYPE_RINGBUF:
1899 		/* Source and destination may possibly overlap, hence use memmove to
1900 		 * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
1901 		 * pointing to overlapping PTR_TO_MAP_VALUE regions.
1902 		 */
1903 		memmove(dst, src->data + src->offset + offset, len);
1904 		return 0;
1905 	case BPF_DYNPTR_TYPE_SKB:
1906 		return __bpf_skb_load_bytes(src->data, src->offset + offset, dst, len);
1907 	case BPF_DYNPTR_TYPE_XDP:
1908 		return __bpf_xdp_load_bytes(src->data, src->offset + offset, dst, len);
1909 	case BPF_DYNPTR_TYPE_SKB_META:
1910 		memmove(dst, bpf_skb_meta_pointer(src->data, src->offset + offset), len);
1911 		return 0;
1912 	case BPF_DYNPTR_TYPE_FILE:
1913 		return bpf_file_fetch_bytes(src->data, offset, dst, len);
1914 	default:
1915 		WARN_ONCE(true, "bpf_dynptr_read: unknown dynptr type %d\n", type);
1916 		return -EFAULT;
1917 	}
1918 }
1919 
1920 BPF_CALL_5(bpf_dynptr_read, void *, dst, u64, len, const struct bpf_dynptr_kern *, src,
1921 	   u64, offset, u64, flags)
1922 {
1923 	return __bpf_dynptr_read(dst, len, src, offset, flags);
1924 }
1925 
1926 static const struct bpf_func_proto bpf_dynptr_read_proto = {
1927 	.func		= bpf_dynptr_read,
1928 	.gpl_only	= false,
1929 	.ret_type	= RET_INTEGER,
1930 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1931 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1932 	.arg3_type	= ARG_PTR_TO_DYNPTR | MEM_RDONLY,
1933 	.arg4_type	= ARG_ANYTHING,
1934 	.arg5_type	= ARG_ANYTHING,
1935 };
1936 
1937 int __bpf_dynptr_write(const struct bpf_dynptr_kern *dst, u64 offset, void *src,
1938 		       u64 len, u64 flags)
1939 {
1940 	enum bpf_dynptr_type type;
1941 	int err;
1942 
1943 	if (!dst->data || __bpf_dynptr_is_rdonly(dst))
1944 		return -EINVAL;
1945 
1946 	err = bpf_dynptr_check_off_len(dst, offset, len);
1947 	if (err)
1948 		return err;
1949 
1950 	type = bpf_dynptr_get_type(dst);
1951 
1952 	switch (type) {
1953 	case BPF_DYNPTR_TYPE_LOCAL:
1954 	case BPF_DYNPTR_TYPE_RINGBUF:
1955 		if (flags)
1956 			return -EINVAL;
1957 		/* Source and destination may possibly overlap, hence use memmove to
1958 		 * copy the data. E.g. bpf_dynptr_from_mem may create two dynptr
1959 		 * pointing to overlapping PTR_TO_MAP_VALUE regions.
1960 		 */
1961 		memmove(dst->data + dst->offset + offset, src, len);
1962 		return 0;
1963 	case BPF_DYNPTR_TYPE_SKB:
1964 		return __bpf_skb_store_bytes(dst->data, dst->offset + offset, src, len,
1965 					     flags);
1966 	case BPF_DYNPTR_TYPE_XDP:
1967 		if (flags)
1968 			return -EINVAL;
1969 		return __bpf_xdp_store_bytes(dst->data, dst->offset + offset, src, len);
1970 	case BPF_DYNPTR_TYPE_SKB_META:
1971 		return __bpf_skb_meta_store_bytes(dst->data, dst->offset + offset, src,
1972 						  len, flags);
1973 	default:
1974 		WARN_ONCE(true, "bpf_dynptr_write: unknown dynptr type %d\n", type);
1975 		return -EFAULT;
1976 	}
1977 }
1978 
1979 BPF_CALL_5(bpf_dynptr_write, const struct bpf_dynptr_kern *, dst, u64, offset, void *, src,
1980 	   u64, len, u64, flags)
1981 {
1982 	return __bpf_dynptr_write(dst, offset, src, len, flags);
1983 }
1984 
1985 static const struct bpf_func_proto bpf_dynptr_write_proto = {
1986 	.func		= bpf_dynptr_write,
1987 	.gpl_only	= false,
1988 	.ret_type	= RET_INTEGER,
1989 	.arg1_type	= ARG_PTR_TO_DYNPTR | MEM_RDONLY,
1990 	.arg2_type	= ARG_ANYTHING,
1991 	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1992 	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
1993 	.arg5_type	= ARG_ANYTHING,
1994 };
1995 
1996 BPF_CALL_3(bpf_dynptr_data, const struct bpf_dynptr_kern *, ptr, u64, offset, u64, len)
1997 {
1998 	enum bpf_dynptr_type type;
1999 	int err;
2000 
2001 	if (!ptr->data)
2002 		return 0;
2003 
2004 	err = bpf_dynptr_check_off_len(ptr, offset, len);
2005 	if (err)
2006 		return 0;
2007 
2008 	if (__bpf_dynptr_is_rdonly(ptr))
2009 		return 0;
2010 
2011 	type = bpf_dynptr_get_type(ptr);
2012 
2013 	switch (type) {
2014 	case BPF_DYNPTR_TYPE_LOCAL:
2015 	case BPF_DYNPTR_TYPE_RINGBUF:
2016 		return (unsigned long)(ptr->data + ptr->offset + offset);
2017 	case BPF_DYNPTR_TYPE_SKB:
2018 	case BPF_DYNPTR_TYPE_XDP:
2019 	case BPF_DYNPTR_TYPE_SKB_META:
2020 		/* skb and xdp dynptrs should use bpf_dynptr_slice / bpf_dynptr_slice_rdwr */
2021 		return 0;
2022 	default:
2023 		WARN_ONCE(true, "bpf_dynptr_data: unknown dynptr type %d\n", type);
2024 		return 0;
2025 	}
2026 }
2027 
2028 static const struct bpf_func_proto bpf_dynptr_data_proto = {
2029 	.func		= bpf_dynptr_data,
2030 	.gpl_only	= false,
2031 	.ret_type	= RET_PTR_TO_DYNPTR_MEM_OR_NULL,
2032 	.arg1_type	= ARG_PTR_TO_DYNPTR | MEM_RDONLY,
2033 	.arg2_type	= ARG_ANYTHING,
2034 	.arg3_type	= ARG_CONST_ALLOC_SIZE_OR_ZERO,
2035 };
2036 
2037 const struct bpf_func_proto bpf_get_current_task_proto __weak;
2038 const struct bpf_func_proto bpf_get_current_task_btf_proto __weak;
2039 const struct bpf_func_proto bpf_probe_read_user_proto __weak;
2040 const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
2041 const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
2042 const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;
2043 const struct bpf_func_proto bpf_task_pt_regs_proto __weak;
2044 const struct bpf_func_proto bpf_perf_event_read_proto __weak;
2045 const struct bpf_func_proto bpf_send_signal_proto __weak;
2046 const struct bpf_func_proto bpf_send_signal_thread_proto __weak;
2047 const struct bpf_func_proto bpf_get_task_stack_sleepable_proto __weak;
2048 const struct bpf_func_proto bpf_get_task_stack_proto __weak;
2049 const struct bpf_func_proto bpf_get_branch_snapshot_proto __weak;
2050 
2051 const struct bpf_func_proto *
2052 bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
2053 {
2054 	switch (func_id) {
2055 	case BPF_FUNC_map_lookup_elem:
2056 		return &bpf_map_lookup_elem_proto;
2057 	case BPF_FUNC_map_update_elem:
2058 		return &bpf_map_update_elem_proto;
2059 	case BPF_FUNC_map_delete_elem:
2060 		return &bpf_map_delete_elem_proto;
2061 	case BPF_FUNC_map_push_elem:
2062 		return &bpf_map_push_elem_proto;
2063 	case BPF_FUNC_map_pop_elem:
2064 		return &bpf_map_pop_elem_proto;
2065 	case BPF_FUNC_map_peek_elem:
2066 		return &bpf_map_peek_elem_proto;
2067 	case BPF_FUNC_map_lookup_percpu_elem:
2068 		return &bpf_map_lookup_percpu_elem_proto;
2069 	case BPF_FUNC_get_prandom_u32:
2070 		return &bpf_get_prandom_u32_proto;
2071 	case BPF_FUNC_get_smp_processor_id:
2072 		return &bpf_get_raw_smp_processor_id_proto;
2073 	case BPF_FUNC_get_numa_node_id:
2074 		return &bpf_get_numa_node_id_proto;
2075 	case BPF_FUNC_tail_call:
2076 		return &bpf_tail_call_proto;
2077 	case BPF_FUNC_ktime_get_ns:
2078 		return &bpf_ktime_get_ns_proto;
2079 	case BPF_FUNC_ktime_get_boot_ns:
2080 		return &bpf_ktime_get_boot_ns_proto;
2081 	case BPF_FUNC_ktime_get_tai_ns:
2082 		return &bpf_ktime_get_tai_ns_proto;
2083 	case BPF_FUNC_ringbuf_output:
2084 		return &bpf_ringbuf_output_proto;
2085 	case BPF_FUNC_ringbuf_reserve:
2086 		return &bpf_ringbuf_reserve_proto;
2087 	case BPF_FUNC_ringbuf_submit:
2088 		return &bpf_ringbuf_submit_proto;
2089 	case BPF_FUNC_ringbuf_discard:
2090 		return &bpf_ringbuf_discard_proto;
2091 	case BPF_FUNC_ringbuf_query:
2092 		return &bpf_ringbuf_query_proto;
2093 	case BPF_FUNC_strncmp:
2094 		return &bpf_strncmp_proto;
2095 	case BPF_FUNC_strtol:
2096 		return &bpf_strtol_proto;
2097 	case BPF_FUNC_strtoul:
2098 		return &bpf_strtoul_proto;
2099 	case BPF_FUNC_get_current_pid_tgid:
2100 		return &bpf_get_current_pid_tgid_proto;
2101 	case BPF_FUNC_get_ns_current_pid_tgid:
2102 		return &bpf_get_ns_current_pid_tgid_proto;
2103 	case BPF_FUNC_get_current_uid_gid:
2104 		return &bpf_get_current_uid_gid_proto;
2105 	default:
2106 		break;
2107 	}
2108 
2109 	if (!bpf_token_capable(prog->aux->token, CAP_BPF))
2110 		return NULL;
2111 
2112 	switch (func_id) {
2113 	case BPF_FUNC_spin_lock:
2114 		return &bpf_spin_lock_proto;
2115 	case BPF_FUNC_spin_unlock:
2116 		return &bpf_spin_unlock_proto;
2117 	case BPF_FUNC_jiffies64:
2118 		return &bpf_jiffies64_proto;
2119 	case BPF_FUNC_per_cpu_ptr:
2120 		return &bpf_per_cpu_ptr_proto;
2121 	case BPF_FUNC_this_cpu_ptr:
2122 		return &bpf_this_cpu_ptr_proto;
2123 	case BPF_FUNC_timer_init:
2124 		return &bpf_timer_init_proto;
2125 	case BPF_FUNC_timer_set_callback:
2126 		return &bpf_timer_set_callback_proto;
2127 	case BPF_FUNC_timer_start:
2128 		return &bpf_timer_start_proto;
2129 	case BPF_FUNC_timer_cancel:
2130 		return &bpf_timer_cancel_proto;
2131 	case BPF_FUNC_kptr_xchg:
2132 		return &bpf_kptr_xchg_proto;
2133 	case BPF_FUNC_for_each_map_elem:
2134 		return &bpf_for_each_map_elem_proto;
2135 	case BPF_FUNC_loop:
2136 		return &bpf_loop_proto;
2137 	case BPF_FUNC_user_ringbuf_drain:
2138 		return &bpf_user_ringbuf_drain_proto;
2139 	case BPF_FUNC_ringbuf_reserve_dynptr:
2140 		return &bpf_ringbuf_reserve_dynptr_proto;
2141 	case BPF_FUNC_ringbuf_submit_dynptr:
2142 		return &bpf_ringbuf_submit_dynptr_proto;
2143 	case BPF_FUNC_ringbuf_discard_dynptr:
2144 		return &bpf_ringbuf_discard_dynptr_proto;
2145 	case BPF_FUNC_dynptr_from_mem:
2146 		return &bpf_dynptr_from_mem_proto;
2147 	case BPF_FUNC_dynptr_read:
2148 		return &bpf_dynptr_read_proto;
2149 	case BPF_FUNC_dynptr_write:
2150 		return &bpf_dynptr_write_proto;
2151 	case BPF_FUNC_dynptr_data:
2152 		return &bpf_dynptr_data_proto;
2153 #ifdef CONFIG_CGROUPS
2154 	case BPF_FUNC_cgrp_storage_get:
2155 		return &bpf_cgrp_storage_get_proto;
2156 	case BPF_FUNC_cgrp_storage_delete:
2157 		return &bpf_cgrp_storage_delete_proto;
2158 	case BPF_FUNC_get_current_cgroup_id:
2159 		return &bpf_get_current_cgroup_id_proto;
2160 	case BPF_FUNC_get_current_ancestor_cgroup_id:
2161 		return &bpf_get_current_ancestor_cgroup_id_proto;
2162 	case BPF_FUNC_current_task_under_cgroup:
2163 		return &bpf_current_task_under_cgroup_proto;
2164 #endif
2165 #ifdef CONFIG_CGROUP_NET_CLASSID
2166 	case BPF_FUNC_get_cgroup_classid:
2167 		return &bpf_get_cgroup_classid_curr_proto;
2168 #endif
2169 	case BPF_FUNC_task_storage_get:
2170 		return &bpf_task_storage_get_proto;
2171 	case BPF_FUNC_task_storage_delete:
2172 		return &bpf_task_storage_delete_proto;
2173 	default:
2174 		break;
2175 	}
2176 
2177 	if (!bpf_token_capable(prog->aux->token, CAP_PERFMON))
2178 		return NULL;
2179 
2180 	switch (func_id) {
2181 	case BPF_FUNC_trace_printk:
2182 		return bpf_get_trace_printk_proto();
2183 	case BPF_FUNC_get_current_task:
2184 		return &bpf_get_current_task_proto;
2185 	case BPF_FUNC_get_current_task_btf:
2186 		return &bpf_get_current_task_btf_proto;
2187 	case BPF_FUNC_get_current_comm:
2188 		return &bpf_get_current_comm_proto;
2189 	case BPF_FUNC_probe_read_user:
2190 		return &bpf_probe_read_user_proto;
2191 	case BPF_FUNC_probe_read_kernel:
2192 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
2193 		       NULL : &bpf_probe_read_kernel_proto;
2194 	case BPF_FUNC_probe_read_user_str:
2195 		return &bpf_probe_read_user_str_proto;
2196 	case BPF_FUNC_probe_read_kernel_str:
2197 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
2198 		       NULL : &bpf_probe_read_kernel_str_proto;
2199 	case BPF_FUNC_copy_from_user:
2200 		return &bpf_copy_from_user_proto;
2201 	case BPF_FUNC_copy_from_user_task:
2202 		return &bpf_copy_from_user_task_proto;
2203 	case BPF_FUNC_snprintf_btf:
2204 		return &bpf_snprintf_btf_proto;
2205 	case BPF_FUNC_snprintf:
2206 		return &bpf_snprintf_proto;
2207 	case BPF_FUNC_task_pt_regs:
2208 		return &bpf_task_pt_regs_proto;
2209 	case BPF_FUNC_trace_vprintk:
2210 		return bpf_get_trace_vprintk_proto();
2211 	case BPF_FUNC_perf_event_read_value:
2212 		return bpf_get_perf_event_read_value_proto();
2213 	case BPF_FUNC_perf_event_read:
2214 		return &bpf_perf_event_read_proto;
2215 	case BPF_FUNC_send_signal:
2216 		return &bpf_send_signal_proto;
2217 	case BPF_FUNC_send_signal_thread:
2218 		return &bpf_send_signal_thread_proto;
2219 	case BPF_FUNC_get_task_stack:
2220 		return prog->sleepable ? &bpf_get_task_stack_sleepable_proto
2221 				       : &bpf_get_task_stack_proto;
2222 	case BPF_FUNC_get_branch_snapshot:
2223 		return &bpf_get_branch_snapshot_proto;
2224 	case BPF_FUNC_find_vma:
2225 		return &bpf_find_vma_proto;
2226 	default:
2227 		return NULL;
2228 	}
2229 }
2230 EXPORT_SYMBOL_GPL(bpf_base_func_proto);
2231 
2232 void bpf_list_head_free(const struct btf_field *field, void *list_head,
2233 			struct bpf_spin_lock *spin_lock)
2234 {
2235 	struct list_head *head = list_head, *orig_head = list_head;
2236 
2237 	BUILD_BUG_ON(sizeof(struct list_head) > sizeof(struct bpf_list_head));
2238 	BUILD_BUG_ON(__alignof__(struct list_head) > __alignof__(struct bpf_list_head));
2239 
2240 	/* Do the actual list draining outside the lock to not hold the lock for
2241 	 * too long, and also prevent deadlocks if tracing programs end up
2242 	 * executing on entry/exit of functions called inside the critical
2243 	 * section, and end up doing map ops that call bpf_list_head_free for
2244 	 * the same map value again.
2245 	 */
2246 	__bpf_spin_lock_irqsave(spin_lock);
2247 	if (!head->next || list_empty(head))
2248 		goto unlock;
2249 	head = head->next;
2250 unlock:
2251 	INIT_LIST_HEAD(orig_head);
2252 	__bpf_spin_unlock_irqrestore(spin_lock);
2253 
2254 	while (head != orig_head) {
2255 		void *obj = head;
2256 
2257 		obj -= field->graph_root.node_offset;
2258 		head = head->next;
2259 		/* The contained type can also have resources, including a
2260 		 * bpf_list_head which needs to be freed.
2261 		 */
2262 		__bpf_obj_drop_impl(obj, field->graph_root.value_rec, false);
2263 	}
2264 }
2265 
2266 /* Like rbtree_postorder_for_each_entry_safe, but 'pos' and 'n' are
2267  * 'rb_node *', so field name of rb_node within containing struct is not
2268  * needed.
2269  *
2270  * Since bpf_rb_tree's node type has a corresponding struct btf_field with
2271  * graph_root.node_offset, it's not necessary to know field name
2272  * or type of node struct
2273  */
2274 #define bpf_rbtree_postorder_for_each_entry_safe(pos, n, root) \
2275 	for (pos = rb_first_postorder(root); \
2276 	    pos && ({ n = rb_next_postorder(pos); 1; }); \
2277 	    pos = n)
2278 
2279 void bpf_rb_root_free(const struct btf_field *field, void *rb_root,
2280 		      struct bpf_spin_lock *spin_lock)
2281 {
2282 	struct rb_root_cached orig_root, *root = rb_root;
2283 	struct rb_node *pos, *n;
2284 	void *obj;
2285 
2286 	BUILD_BUG_ON(sizeof(struct rb_root_cached) > sizeof(struct bpf_rb_root));
2287 	BUILD_BUG_ON(__alignof__(struct rb_root_cached) > __alignof__(struct bpf_rb_root));
2288 
2289 	__bpf_spin_lock_irqsave(spin_lock);
2290 	orig_root = *root;
2291 	*root = RB_ROOT_CACHED;
2292 	__bpf_spin_unlock_irqrestore(spin_lock);
2293 
2294 	bpf_rbtree_postorder_for_each_entry_safe(pos, n, &orig_root.rb_root) {
2295 		obj = pos;
2296 		obj -= field->graph_root.node_offset;
2297 
2298 
2299 		__bpf_obj_drop_impl(obj, field->graph_root.value_rec, false);
2300 	}
2301 }
2302 
2303 __bpf_kfunc_start_defs();
2304 
2305 __bpf_kfunc void *bpf_obj_new_impl(u64 local_type_id__k, void *meta__ign)
2306 {
2307 	struct btf_struct_meta *meta = meta__ign;
2308 	u64 size = local_type_id__k;
2309 	void *p;
2310 
2311 	p = bpf_mem_alloc(&bpf_global_ma, size);
2312 	if (!p)
2313 		return NULL;
2314 	if (meta)
2315 		bpf_obj_init(meta->record, p);
2316 	return p;
2317 }
2318 
2319 __bpf_kfunc void *bpf_percpu_obj_new_impl(u64 local_type_id__k, void *meta__ign)
2320 {
2321 	u64 size = local_type_id__k;
2322 
2323 	/* The verifier has ensured that meta__ign must be NULL */
2324 	return bpf_mem_alloc(&bpf_global_percpu_ma, size);
2325 }
2326 
2327 /* Must be called under migrate_disable(), as required by bpf_mem_free */
2328 void __bpf_obj_drop_impl(void *p, const struct btf_record *rec, bool percpu)
2329 {
2330 	struct bpf_mem_alloc *ma;
2331 
2332 	if (rec && rec->refcount_off >= 0 &&
2333 	    !refcount_dec_and_test((refcount_t *)(p + rec->refcount_off))) {
2334 		/* Object is refcounted and refcount_dec didn't result in 0
2335 		 * refcount. Return without freeing the object
2336 		 */
2337 		return;
2338 	}
2339 
2340 	if (rec)
2341 		bpf_obj_free_fields(rec, p);
2342 
2343 	if (percpu)
2344 		ma = &bpf_global_percpu_ma;
2345 	else
2346 		ma = &bpf_global_ma;
2347 	bpf_mem_free_rcu(ma, p);
2348 }
2349 
2350 __bpf_kfunc void bpf_obj_drop_impl(void *p__alloc, void *meta__ign)
2351 {
2352 	struct btf_struct_meta *meta = meta__ign;
2353 	void *p = p__alloc;
2354 
2355 	__bpf_obj_drop_impl(p, meta ? meta->record : NULL, false);
2356 }
2357 
2358 __bpf_kfunc void bpf_percpu_obj_drop_impl(void *p__alloc, void *meta__ign)
2359 {
2360 	/* The verifier has ensured that meta__ign must be NULL */
2361 	bpf_mem_free_rcu(&bpf_global_percpu_ma, p__alloc);
2362 }
2363 
2364 __bpf_kfunc void *bpf_refcount_acquire_impl(void *p__refcounted_kptr, void *meta__ign)
2365 {
2366 	struct btf_struct_meta *meta = meta__ign;
2367 	struct bpf_refcount *ref;
2368 
2369 	/* Could just cast directly to refcount_t *, but need some code using
2370 	 * bpf_refcount type so that it is emitted in vmlinux BTF
2371 	 */
2372 	ref = (struct bpf_refcount *)(p__refcounted_kptr + meta->record->refcount_off);
2373 	if (!refcount_inc_not_zero((refcount_t *)ref))
2374 		return NULL;
2375 
2376 	/* Verifier strips KF_RET_NULL if input is owned ref, see is_kfunc_ret_null
2377 	 * in verifier.c
2378 	 */
2379 	return (void *)p__refcounted_kptr;
2380 }
2381 
2382 static int __bpf_list_add(struct bpf_list_node_kern *node,
2383 			  struct bpf_list_head *head,
2384 			  bool tail, struct btf_record *rec, u64 off)
2385 {
2386 	struct list_head *n = &node->list_head, *h = (void *)head;
2387 
2388 	/* If list_head was 0-initialized by map, bpf_obj_init_field wasn't
2389 	 * called on its fields, so init here
2390 	 */
2391 	if (unlikely(!h->next))
2392 		INIT_LIST_HEAD(h);
2393 
2394 	/* node->owner != NULL implies !list_empty(n), no need to separately
2395 	 * check the latter
2396 	 */
2397 	if (cmpxchg(&node->owner, NULL, BPF_PTR_POISON)) {
2398 		/* Only called from BPF prog, no need to migrate_disable */
2399 		__bpf_obj_drop_impl((void *)n - off, rec, false);
2400 		return -EINVAL;
2401 	}
2402 
2403 	tail ? list_add_tail(n, h) : list_add(n, h);
2404 	WRITE_ONCE(node->owner, head);
2405 
2406 	return 0;
2407 }
2408 
2409 __bpf_kfunc int bpf_list_push_front_impl(struct bpf_list_head *head,
2410 					 struct bpf_list_node *node,
2411 					 void *meta__ign, u64 off)
2412 {
2413 	struct bpf_list_node_kern *n = (void *)node;
2414 	struct btf_struct_meta *meta = meta__ign;
2415 
2416 	return __bpf_list_add(n, head, false, meta ? meta->record : NULL, off);
2417 }
2418 
2419 __bpf_kfunc int bpf_list_push_back_impl(struct bpf_list_head *head,
2420 					struct bpf_list_node *node,
2421 					void *meta__ign, u64 off)
2422 {
2423 	struct bpf_list_node_kern *n = (void *)node;
2424 	struct btf_struct_meta *meta = meta__ign;
2425 
2426 	return __bpf_list_add(n, head, true, meta ? meta->record : NULL, off);
2427 }
2428 
2429 static struct bpf_list_node *__bpf_list_del(struct bpf_list_head *head, bool tail)
2430 {
2431 	struct list_head *n, *h = (void *)head;
2432 	struct bpf_list_node_kern *node;
2433 
2434 	/* If list_head was 0-initialized by map, bpf_obj_init_field wasn't
2435 	 * called on its fields, so init here
2436 	 */
2437 	if (unlikely(!h->next))
2438 		INIT_LIST_HEAD(h);
2439 	if (list_empty(h))
2440 		return NULL;
2441 
2442 	n = tail ? h->prev : h->next;
2443 	node = container_of(n, struct bpf_list_node_kern, list_head);
2444 	if (WARN_ON_ONCE(READ_ONCE(node->owner) != head))
2445 		return NULL;
2446 
2447 	list_del_init(n);
2448 	WRITE_ONCE(node->owner, NULL);
2449 	return (struct bpf_list_node *)n;
2450 }
2451 
2452 __bpf_kfunc struct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head)
2453 {
2454 	return __bpf_list_del(head, false);
2455 }
2456 
2457 __bpf_kfunc struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head)
2458 {
2459 	return __bpf_list_del(head, true);
2460 }
2461 
2462 __bpf_kfunc struct bpf_list_node *bpf_list_front(struct bpf_list_head *head)
2463 {
2464 	struct list_head *h = (struct list_head *)head;
2465 
2466 	if (list_empty(h) || unlikely(!h->next))
2467 		return NULL;
2468 
2469 	return (struct bpf_list_node *)h->next;
2470 }
2471 
2472 __bpf_kfunc struct bpf_list_node *bpf_list_back(struct bpf_list_head *head)
2473 {
2474 	struct list_head *h = (struct list_head *)head;
2475 
2476 	if (list_empty(h) || unlikely(!h->next))
2477 		return NULL;
2478 
2479 	return (struct bpf_list_node *)h->prev;
2480 }
2481 
2482 __bpf_kfunc struct bpf_rb_node *bpf_rbtree_remove(struct bpf_rb_root *root,
2483 						  struct bpf_rb_node *node)
2484 {
2485 	struct bpf_rb_node_kern *node_internal = (struct bpf_rb_node_kern *)node;
2486 	struct rb_root_cached *r = (struct rb_root_cached *)root;
2487 	struct rb_node *n = &node_internal->rb_node;
2488 
2489 	/* node_internal->owner != root implies either RB_EMPTY_NODE(n) or
2490 	 * n is owned by some other tree. No need to check RB_EMPTY_NODE(n)
2491 	 */
2492 	if (READ_ONCE(node_internal->owner) != root)
2493 		return NULL;
2494 
2495 	rb_erase_cached(n, r);
2496 	RB_CLEAR_NODE(n);
2497 	WRITE_ONCE(node_internal->owner, NULL);
2498 	return (struct bpf_rb_node *)n;
2499 }
2500 
2501 /* Need to copy rbtree_add_cached's logic here because our 'less' is a BPF
2502  * program
2503  */
2504 static int __bpf_rbtree_add(struct bpf_rb_root *root,
2505 			    struct bpf_rb_node_kern *node,
2506 			    void *less, struct btf_record *rec, u64 off)
2507 {
2508 	struct rb_node **link = &((struct rb_root_cached *)root)->rb_root.rb_node;
2509 	struct rb_node *parent = NULL, *n = &node->rb_node;
2510 	bpf_callback_t cb = (bpf_callback_t)less;
2511 	bool leftmost = true;
2512 
2513 	/* node->owner != NULL implies !RB_EMPTY_NODE(n), no need to separately
2514 	 * check the latter
2515 	 */
2516 	if (cmpxchg(&node->owner, NULL, BPF_PTR_POISON)) {
2517 		/* Only called from BPF prog, no need to migrate_disable */
2518 		__bpf_obj_drop_impl((void *)n - off, rec, false);
2519 		return -EINVAL;
2520 	}
2521 
2522 	while (*link) {
2523 		parent = *link;
2524 		if (cb((uintptr_t)node, (uintptr_t)parent, 0, 0, 0)) {
2525 			link = &parent->rb_left;
2526 		} else {
2527 			link = &parent->rb_right;
2528 			leftmost = false;
2529 		}
2530 	}
2531 
2532 	rb_link_node(n, parent, link);
2533 	rb_insert_color_cached(n, (struct rb_root_cached *)root, leftmost);
2534 	WRITE_ONCE(node->owner, root);
2535 	return 0;
2536 }
2537 
2538 __bpf_kfunc int bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *node,
2539 				    bool (less)(struct bpf_rb_node *a, const struct bpf_rb_node *b),
2540 				    void *meta__ign, u64 off)
2541 {
2542 	struct btf_struct_meta *meta = meta__ign;
2543 	struct bpf_rb_node_kern *n = (void *)node;
2544 
2545 	return __bpf_rbtree_add(root, n, (void *)less, meta ? meta->record : NULL, off);
2546 }
2547 
2548 __bpf_kfunc struct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root)
2549 {
2550 	struct rb_root_cached *r = (struct rb_root_cached *)root;
2551 
2552 	return (struct bpf_rb_node *)rb_first_cached(r);
2553 }
2554 
2555 __bpf_kfunc struct bpf_rb_node *bpf_rbtree_root(struct bpf_rb_root *root)
2556 {
2557 	struct rb_root_cached *r = (struct rb_root_cached *)root;
2558 
2559 	return (struct bpf_rb_node *)r->rb_root.rb_node;
2560 }
2561 
2562 __bpf_kfunc struct bpf_rb_node *bpf_rbtree_left(struct bpf_rb_root *root, struct bpf_rb_node *node)
2563 {
2564 	struct bpf_rb_node_kern *node_internal = (struct bpf_rb_node_kern *)node;
2565 
2566 	if (READ_ONCE(node_internal->owner) != root)
2567 		return NULL;
2568 
2569 	return (struct bpf_rb_node *)node_internal->rb_node.rb_left;
2570 }
2571 
2572 __bpf_kfunc struct bpf_rb_node *bpf_rbtree_right(struct bpf_rb_root *root, struct bpf_rb_node *node)
2573 {
2574 	struct bpf_rb_node_kern *node_internal = (struct bpf_rb_node_kern *)node;
2575 
2576 	if (READ_ONCE(node_internal->owner) != root)
2577 		return NULL;
2578 
2579 	return (struct bpf_rb_node *)node_internal->rb_node.rb_right;
2580 }
2581 
2582 /**
2583  * bpf_task_acquire - Acquire a reference to a task. A task acquired by this
2584  * kfunc which is not stored in a map as a kptr, must be released by calling
2585  * bpf_task_release().
2586  * @p: The task on which a reference is being acquired.
2587  */
2588 __bpf_kfunc struct task_struct *bpf_task_acquire(struct task_struct *p)
2589 {
2590 	if (refcount_inc_not_zero(&p->rcu_users))
2591 		return p;
2592 	return NULL;
2593 }
2594 
2595 /**
2596  * bpf_task_release - Release the reference acquired on a task.
2597  * @p: The task on which a reference is being released.
2598  */
2599 __bpf_kfunc void bpf_task_release(struct task_struct *p)
2600 {
2601 	put_task_struct_rcu_user(p);
2602 }
2603 
2604 __bpf_kfunc void bpf_task_release_dtor(void *p)
2605 {
2606 	put_task_struct_rcu_user(p);
2607 }
2608 CFI_NOSEAL(bpf_task_release_dtor);
2609 
2610 #ifdef CONFIG_CGROUPS
2611 /**
2612  * bpf_cgroup_acquire - Acquire a reference to a cgroup. A cgroup acquired by
2613  * this kfunc which is not stored in a map as a kptr, must be released by
2614  * calling bpf_cgroup_release().
2615  * @cgrp: The cgroup on which a reference is being acquired.
2616  */
2617 __bpf_kfunc struct cgroup *bpf_cgroup_acquire(struct cgroup *cgrp)
2618 {
2619 	return cgroup_tryget(cgrp) ? cgrp : NULL;
2620 }
2621 
2622 /**
2623  * bpf_cgroup_release - Release the reference acquired on a cgroup.
2624  * If this kfunc is invoked in an RCU read region, the cgroup is guaranteed to
2625  * not be freed until the current grace period has ended, even if its refcount
2626  * drops to 0.
2627  * @cgrp: The cgroup on which a reference is being released.
2628  */
2629 __bpf_kfunc void bpf_cgroup_release(struct cgroup *cgrp)
2630 {
2631 	cgroup_put(cgrp);
2632 }
2633 
2634 __bpf_kfunc void bpf_cgroup_release_dtor(void *cgrp)
2635 {
2636 	cgroup_put(cgrp);
2637 }
2638 CFI_NOSEAL(bpf_cgroup_release_dtor);
2639 
2640 /**
2641  * bpf_cgroup_ancestor - Perform a lookup on an entry in a cgroup's ancestor
2642  * array. A cgroup returned by this kfunc which is not subsequently stored in a
2643  * map, must be released by calling bpf_cgroup_release().
2644  * @cgrp: The cgroup for which we're performing a lookup.
2645  * @level: The level of ancestor to look up.
2646  */
2647 __bpf_kfunc struct cgroup *bpf_cgroup_ancestor(struct cgroup *cgrp, int level)
2648 {
2649 	struct cgroup *ancestor;
2650 
2651 	if (level > cgrp->level || level < 0)
2652 		return NULL;
2653 
2654 	/* cgrp's refcnt could be 0 here, but ancestors can still be accessed */
2655 	ancestor = cgrp->ancestors[level];
2656 	if (!cgroup_tryget(ancestor))
2657 		return NULL;
2658 	return ancestor;
2659 }
2660 
2661 /**
2662  * bpf_cgroup_from_id - Find a cgroup from its ID. A cgroup returned by this
2663  * kfunc which is not subsequently stored in a map, must be released by calling
2664  * bpf_cgroup_release().
2665  * @cgid: cgroup id.
2666  */
2667 __bpf_kfunc struct cgroup *bpf_cgroup_from_id(u64 cgid)
2668 {
2669 	struct cgroup *cgrp;
2670 
2671 	cgrp = __cgroup_get_from_id(cgid);
2672 	if (IS_ERR(cgrp))
2673 		return NULL;
2674 	return cgrp;
2675 }
2676 
2677 /**
2678  * bpf_task_under_cgroup - wrap task_under_cgroup_hierarchy() as a kfunc, test
2679  * task's membership of cgroup ancestry.
2680  * @task: the task to be tested
2681  * @ancestor: possible ancestor of @task's cgroup
2682  *
2683  * Tests whether @task's default cgroup hierarchy is a descendant of @ancestor.
2684  * It follows all the same rules as cgroup_is_descendant, and only applies
2685  * to the default hierarchy.
2686  */
2687 __bpf_kfunc long bpf_task_under_cgroup(struct task_struct *task,
2688 				       struct cgroup *ancestor)
2689 {
2690 	long ret;
2691 
2692 	rcu_read_lock();
2693 	ret = task_under_cgroup_hierarchy(task, ancestor);
2694 	rcu_read_unlock();
2695 	return ret;
2696 }
2697 
2698 BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
2699 {
2700 	struct bpf_array *array = container_of(map, struct bpf_array, map);
2701 	struct cgroup *cgrp;
2702 
2703 	if (unlikely(idx >= array->map.max_entries))
2704 		return -E2BIG;
2705 
2706 	cgrp = READ_ONCE(array->ptrs[idx]);
2707 	if (unlikely(!cgrp))
2708 		return -EAGAIN;
2709 
2710 	return task_under_cgroup_hierarchy(current, cgrp);
2711 }
2712 
2713 const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
2714 	.func           = bpf_current_task_under_cgroup,
2715 	.gpl_only       = false,
2716 	.ret_type       = RET_INTEGER,
2717 	.arg1_type      = ARG_CONST_MAP_PTR,
2718 	.arg2_type      = ARG_ANYTHING,
2719 };
2720 
2721 /**
2722  * bpf_task_get_cgroup1 - Acquires the associated cgroup of a task within a
2723  * specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its
2724  * hierarchy ID.
2725  * @task: The target task
2726  * @hierarchy_id: The ID of a cgroup1 hierarchy
2727  *
2728  * On success, the cgroup is returen. On failure, NULL is returned.
2729  */
2730 __bpf_kfunc struct cgroup *
2731 bpf_task_get_cgroup1(struct task_struct *task, int hierarchy_id)
2732 {
2733 	struct cgroup *cgrp = task_get_cgroup1(task, hierarchy_id);
2734 
2735 	if (IS_ERR(cgrp))
2736 		return NULL;
2737 	return cgrp;
2738 }
2739 #endif /* CONFIG_CGROUPS */
2740 
2741 /**
2742  * bpf_task_from_pid - Find a struct task_struct from its pid by looking it up
2743  * in the root pid namespace idr. If a task is returned, it must either be
2744  * stored in a map, or released with bpf_task_release().
2745  * @pid: The pid of the task being looked up.
2746  */
2747 __bpf_kfunc struct task_struct *bpf_task_from_pid(s32 pid)
2748 {
2749 	struct task_struct *p;
2750 
2751 	rcu_read_lock();
2752 	p = find_task_by_pid_ns(pid, &init_pid_ns);
2753 	if (p)
2754 		p = bpf_task_acquire(p);
2755 	rcu_read_unlock();
2756 
2757 	return p;
2758 }
2759 
2760 /**
2761  * bpf_task_from_vpid - Find a struct task_struct from its vpid by looking it up
2762  * in the pid namespace of the current task. If a task is returned, it must
2763  * either be stored in a map, or released with bpf_task_release().
2764  * @vpid: The vpid of the task being looked up.
2765  */
2766 __bpf_kfunc struct task_struct *bpf_task_from_vpid(s32 vpid)
2767 {
2768 	struct task_struct *p;
2769 
2770 	rcu_read_lock();
2771 	p = find_task_by_vpid(vpid);
2772 	if (p)
2773 		p = bpf_task_acquire(p);
2774 	rcu_read_unlock();
2775 
2776 	return p;
2777 }
2778 
2779 /**
2780  * bpf_dynptr_slice() - Obtain a read-only pointer to the dynptr data.
2781  * @p: The dynptr whose data slice to retrieve
2782  * @offset: Offset into the dynptr
2783  * @buffer__nullable: User-provided buffer to copy contents into.  May be NULL
2784  * @buffer__szk: Size (in bytes) of the buffer if present. This is the
2785  *               length of the requested slice. This must be a constant.
2786  *
2787  * For non-skb and non-xdp type dynptrs, there is no difference between
2788  * bpf_dynptr_slice and bpf_dynptr_data.
2789  *
2790  *  If buffer__nullable is NULL, the call will fail if buffer_opt was needed.
2791  *
2792  * If the intention is to write to the data slice, please use
2793  * bpf_dynptr_slice_rdwr.
2794  *
2795  * The user must check that the returned pointer is not null before using it.
2796  *
2797  * Please note that in the case of skb and xdp dynptrs, bpf_dynptr_slice
2798  * does not change the underlying packet data pointers, so a call to
2799  * bpf_dynptr_slice will not invalidate any ctx->data/data_end pointers in
2800  * the bpf program.
2801  *
2802  * Return: NULL if the call failed (eg invalid dynptr), pointer to a read-only
2803  * data slice (can be either direct pointer to the data or a pointer to the user
2804  * provided buffer, with its contents containing the data, if unable to obtain
2805  * direct pointer)
2806  */
2807 __bpf_kfunc void *bpf_dynptr_slice(const struct bpf_dynptr *p, u64 offset,
2808 				   void *buffer__nullable, u64 buffer__szk)
2809 {
2810 	const struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
2811 	enum bpf_dynptr_type type;
2812 	u64 len = buffer__szk;
2813 	int err;
2814 
2815 	if (!ptr->data)
2816 		return NULL;
2817 
2818 	err = bpf_dynptr_check_off_len(ptr, offset, len);
2819 	if (err)
2820 		return NULL;
2821 
2822 	type = bpf_dynptr_get_type(ptr);
2823 
2824 	switch (type) {
2825 	case BPF_DYNPTR_TYPE_LOCAL:
2826 	case BPF_DYNPTR_TYPE_RINGBUF:
2827 		return ptr->data + ptr->offset + offset;
2828 	case BPF_DYNPTR_TYPE_SKB:
2829 		if (buffer__nullable)
2830 			return skb_header_pointer(ptr->data, ptr->offset + offset, len, buffer__nullable);
2831 		else
2832 			return skb_pointer_if_linear(ptr->data, ptr->offset + offset, len);
2833 	case BPF_DYNPTR_TYPE_XDP:
2834 	{
2835 		void *xdp_ptr = bpf_xdp_pointer(ptr->data, ptr->offset + offset, len);
2836 		if (!IS_ERR_OR_NULL(xdp_ptr))
2837 			return xdp_ptr;
2838 
2839 		if (!buffer__nullable)
2840 			return NULL;
2841 		bpf_xdp_copy_buf(ptr->data, ptr->offset + offset, buffer__nullable, len, false);
2842 		return buffer__nullable;
2843 	}
2844 	case BPF_DYNPTR_TYPE_SKB_META:
2845 		return bpf_skb_meta_pointer(ptr->data, ptr->offset + offset);
2846 	case BPF_DYNPTR_TYPE_FILE:
2847 		err = bpf_file_fetch_bytes(ptr->data, offset, buffer__nullable, buffer__szk);
2848 		return err ? NULL : buffer__nullable;
2849 	default:
2850 		WARN_ONCE(true, "unknown dynptr type %d\n", type);
2851 		return NULL;
2852 	}
2853 }
2854 
2855 /**
2856  * bpf_dynptr_slice_rdwr() - Obtain a writable pointer to the dynptr data.
2857  * @p: The dynptr whose data slice to retrieve
2858  * @offset: Offset into the dynptr
2859  * @buffer__nullable: User-provided buffer to copy contents into. May be NULL
2860  * @buffer__szk: Size (in bytes) of the buffer if present. This is the
2861  *               length of the requested slice. This must be a constant.
2862  *
2863  * For non-skb and non-xdp type dynptrs, there is no difference between
2864  * bpf_dynptr_slice and bpf_dynptr_data.
2865  *
2866  * If buffer__nullable is NULL, the call will fail if buffer_opt was needed.
2867  *
2868  * The returned pointer is writable and may point to either directly the dynptr
2869  * data at the requested offset or to the buffer if unable to obtain a direct
2870  * data pointer to (example: the requested slice is to the paged area of an skb
2871  * packet). In the case where the returned pointer is to the buffer, the user
2872  * is responsible for persisting writes through calling bpf_dynptr_write(). This
2873  * usually looks something like this pattern:
2874  *
2875  * struct eth_hdr *eth = bpf_dynptr_slice_rdwr(&dynptr, 0, buffer, sizeof(buffer));
2876  * if (!eth)
2877  *	return TC_ACT_SHOT;
2878  *
2879  * // mutate eth header //
2880  *
2881  * if (eth == buffer)
2882  *	bpf_dynptr_write(&ptr, 0, buffer, sizeof(buffer), 0);
2883  *
2884  * Please note that, as in the example above, the user must check that the
2885  * returned pointer is not null before using it.
2886  *
2887  * Please also note that in the case of skb and xdp dynptrs, bpf_dynptr_slice_rdwr
2888  * does not change the underlying packet data pointers, so a call to
2889  * bpf_dynptr_slice_rdwr will not invalidate any ctx->data/data_end pointers in
2890  * the bpf program.
2891  *
2892  * Return: NULL if the call failed (eg invalid dynptr), pointer to a
2893  * data slice (can be either direct pointer to the data or a pointer to the user
2894  * provided buffer, with its contents containing the data, if unable to obtain
2895  * direct pointer)
2896  */
2897 __bpf_kfunc void *bpf_dynptr_slice_rdwr(const struct bpf_dynptr *p, u64 offset,
2898 					void *buffer__nullable, u64 buffer__szk)
2899 {
2900 	const struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
2901 
2902 	if (!ptr->data || __bpf_dynptr_is_rdonly(ptr))
2903 		return NULL;
2904 
2905 	/* bpf_dynptr_slice_rdwr is the same logic as bpf_dynptr_slice.
2906 	 *
2907 	 * For skb-type dynptrs, it is safe to write into the returned pointer
2908 	 * if the bpf program allows skb data writes. There are two possibilities
2909 	 * that may occur when calling bpf_dynptr_slice_rdwr:
2910 	 *
2911 	 * 1) The requested slice is in the head of the skb. In this case, the
2912 	 * returned pointer is directly to skb data, and if the skb is cloned, the
2913 	 * verifier will have uncloned it (see bpf_unclone_prologue()) already.
2914 	 * The pointer can be directly written into.
2915 	 *
2916 	 * 2) Some portion of the requested slice is in the paged buffer area.
2917 	 * In this case, the requested data will be copied out into the buffer
2918 	 * and the returned pointer will be a pointer to the buffer. The skb
2919 	 * will not be pulled. To persist the write, the user will need to call
2920 	 * bpf_dynptr_write(), which will pull the skb and commit the write.
2921 	 *
2922 	 * Similarly for xdp programs, if the requested slice is not across xdp
2923 	 * fragments, then a direct pointer will be returned, otherwise the data
2924 	 * will be copied out into the buffer and the user will need to call
2925 	 * bpf_dynptr_write() to commit changes.
2926 	 */
2927 	return bpf_dynptr_slice(p, offset, buffer__nullable, buffer__szk);
2928 }
2929 
2930 __bpf_kfunc int bpf_dynptr_adjust(const struct bpf_dynptr *p, u64 start, u64 end)
2931 {
2932 	struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
2933 	u64 size;
2934 
2935 	if (!ptr->data || start > end)
2936 		return -EINVAL;
2937 
2938 	size = __bpf_dynptr_size(ptr);
2939 
2940 	if (start > size || end > size)
2941 		return -ERANGE;
2942 
2943 	bpf_dynptr_advance_offset(ptr, start);
2944 	bpf_dynptr_set_size(ptr, end - start);
2945 
2946 	return 0;
2947 }
2948 
2949 __bpf_kfunc bool bpf_dynptr_is_null(const struct bpf_dynptr *p)
2950 {
2951 	struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
2952 
2953 	return !ptr->data;
2954 }
2955 
2956 __bpf_kfunc bool bpf_dynptr_is_rdonly(const struct bpf_dynptr *p)
2957 {
2958 	struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
2959 
2960 	if (!ptr->data)
2961 		return false;
2962 
2963 	return __bpf_dynptr_is_rdonly(ptr);
2964 }
2965 
2966 __bpf_kfunc u64 bpf_dynptr_size(const struct bpf_dynptr *p)
2967 {
2968 	struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
2969 
2970 	if (!ptr->data)
2971 		return -EINVAL;
2972 
2973 	return __bpf_dynptr_size(ptr);
2974 }
2975 
2976 __bpf_kfunc int bpf_dynptr_clone(const struct bpf_dynptr *p,
2977 				 struct bpf_dynptr *clone__uninit)
2978 {
2979 	struct bpf_dynptr_kern *clone = (struct bpf_dynptr_kern *)clone__uninit;
2980 	struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
2981 
2982 	if (!ptr->data) {
2983 		bpf_dynptr_set_null(clone);
2984 		return -EINVAL;
2985 	}
2986 
2987 	*clone = *ptr;
2988 
2989 	return 0;
2990 }
2991 
2992 /**
2993  * bpf_dynptr_copy() - Copy data from one dynptr to another.
2994  * @dst_ptr: Destination dynptr - where data should be copied to
2995  * @dst_off: Offset into the destination dynptr
2996  * @src_ptr: Source dynptr - where data should be copied from
2997  * @src_off: Offset into the source dynptr
2998  * @size: Length of the data to copy from source to destination
2999  *
3000  * Copies data from source dynptr to destination dynptr.
3001  * Returns 0 on success; negative error, otherwise.
3002  */
3003 __bpf_kfunc int bpf_dynptr_copy(struct bpf_dynptr *dst_ptr, u64 dst_off,
3004 				struct bpf_dynptr *src_ptr, u64 src_off, u64 size)
3005 {
3006 	struct bpf_dynptr_kern *dst = (struct bpf_dynptr_kern *)dst_ptr;
3007 	struct bpf_dynptr_kern *src = (struct bpf_dynptr_kern *)src_ptr;
3008 	void *src_slice, *dst_slice;
3009 	char buf[256];
3010 	u64 off;
3011 
3012 	src_slice = bpf_dynptr_slice(src_ptr, src_off, NULL, size);
3013 	dst_slice = bpf_dynptr_slice_rdwr(dst_ptr, dst_off, NULL, size);
3014 
3015 	if (src_slice && dst_slice) {
3016 		memmove(dst_slice, src_slice, size);
3017 		return 0;
3018 	}
3019 
3020 	if (src_slice)
3021 		return __bpf_dynptr_write(dst, dst_off, src_slice, size, 0);
3022 
3023 	if (dst_slice)
3024 		return __bpf_dynptr_read(dst_slice, size, src, src_off, 0);
3025 
3026 	if (bpf_dynptr_check_off_len(dst, dst_off, size) ||
3027 	    bpf_dynptr_check_off_len(src, src_off, size))
3028 		return -E2BIG;
3029 
3030 	off = 0;
3031 	while (off < size) {
3032 		u64 chunk_sz = min_t(u64, sizeof(buf), size - off);
3033 		int err;
3034 
3035 		err = __bpf_dynptr_read(buf, chunk_sz, src, src_off + off, 0);
3036 		if (err)
3037 			return err;
3038 		err = __bpf_dynptr_write(dst, dst_off + off, buf, chunk_sz, 0);
3039 		if (err)
3040 			return err;
3041 
3042 		off += chunk_sz;
3043 	}
3044 	return 0;
3045 }
3046 
3047 /**
3048  * bpf_dynptr_memset() - Fill dynptr memory with a constant byte.
3049  * @p: Destination dynptr - where data will be filled
3050  * @offset: Offset into the dynptr to start filling from
3051  * @size: Number of bytes to fill
3052  * @val: Constant byte to fill the memory with
3053  *
3054  * Fills the @size bytes of the memory area pointed to by @p
3055  * at @offset with the constant byte @val.
3056  * Returns 0 on success; negative error, otherwise.
3057  */
3058 __bpf_kfunc int bpf_dynptr_memset(struct bpf_dynptr *p, u64 offset, u64 size, u8 val)
3059 {
3060 	struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)p;
3061 	u64 chunk_sz, write_off;
3062 	char buf[256];
3063 	void* slice;
3064 	int err;
3065 
3066 	slice = bpf_dynptr_slice_rdwr(p, offset, NULL, size);
3067 	if (likely(slice)) {
3068 		memset(slice, val, size);
3069 		return 0;
3070 	}
3071 
3072 	if (__bpf_dynptr_is_rdonly(ptr))
3073 		return -EINVAL;
3074 
3075 	err = bpf_dynptr_check_off_len(ptr, offset, size);
3076 	if (err)
3077 		return err;
3078 
3079 	/* Non-linear data under the dynptr, write from a local buffer */
3080 	chunk_sz = min_t(u64, sizeof(buf), size);
3081 	memset(buf, val, chunk_sz);
3082 
3083 	for (write_off = 0; write_off < size; write_off += chunk_sz) {
3084 		chunk_sz = min_t(u64, sizeof(buf), size - write_off);
3085 		err = __bpf_dynptr_write(ptr, offset + write_off, buf, chunk_sz, 0);
3086 		if (err)
3087 			return err;
3088 	}
3089 
3090 	return 0;
3091 }
3092 
3093 __bpf_kfunc void *bpf_cast_to_kern_ctx(void *obj)
3094 {
3095 	return obj;
3096 }
3097 
3098 __bpf_kfunc void *bpf_rdonly_cast(const void *obj__ign, u32 btf_id__k)
3099 {
3100 	return (void *)obj__ign;
3101 }
3102 
3103 __bpf_kfunc void bpf_rcu_read_lock(void)
3104 {
3105 	rcu_read_lock();
3106 }
3107 
3108 __bpf_kfunc void bpf_rcu_read_unlock(void)
3109 {
3110 	rcu_read_unlock();
3111 }
3112 
3113 struct bpf_throw_ctx {
3114 	struct bpf_prog_aux *aux;
3115 	u64 sp;
3116 	u64 bp;
3117 	int cnt;
3118 };
3119 
3120 static bool bpf_stack_walker(void *cookie, u64 ip, u64 sp, u64 bp)
3121 {
3122 	struct bpf_throw_ctx *ctx = cookie;
3123 	struct bpf_prog *prog;
3124 
3125 	/*
3126 	 * The RCU read lock is held to safely traverse the latch tree, but we
3127 	 * don't need its protection when accessing the prog, since it has an
3128 	 * active stack frame on the current stack trace, and won't disappear.
3129 	 */
3130 	rcu_read_lock();
3131 	prog = bpf_prog_ksym_find(ip);
3132 	rcu_read_unlock();
3133 	if (!prog)
3134 		return !ctx->cnt;
3135 	ctx->cnt++;
3136 	if (bpf_is_subprog(prog))
3137 		return true;
3138 	ctx->aux = prog->aux;
3139 	ctx->sp = sp;
3140 	ctx->bp = bp;
3141 	return false;
3142 }
3143 
3144 __bpf_kfunc void bpf_throw(u64 cookie)
3145 {
3146 	struct bpf_throw_ctx ctx = {};
3147 
3148 	arch_bpf_stack_walk(bpf_stack_walker, &ctx);
3149 	WARN_ON_ONCE(!ctx.aux);
3150 	if (ctx.aux)
3151 		WARN_ON_ONCE(!ctx.aux->exception_boundary);
3152 	WARN_ON_ONCE(!ctx.bp);
3153 	WARN_ON_ONCE(!ctx.cnt);
3154 	/* Prevent KASAN false positives for CONFIG_KASAN_STACK by unpoisoning
3155 	 * deeper stack depths than ctx.sp as we do not return from bpf_throw,
3156 	 * which skips compiler generated instrumentation to do the same.
3157 	 */
3158 	kasan_unpoison_task_stack_below((void *)(long)ctx.sp);
3159 	ctx.aux->bpf_exception_cb(cookie, ctx.sp, ctx.bp, 0, 0);
3160 	WARN(1, "A call to BPF exception callback should never return\n");
3161 }
3162 
3163 __bpf_kfunc int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags)
3164 {
3165 	struct bpf_async_kern *async = (struct bpf_async_kern *)wq;
3166 	struct bpf_map *map = p__map;
3167 
3168 	BUILD_BUG_ON(sizeof(struct bpf_async_kern) > sizeof(struct bpf_wq));
3169 	BUILD_BUG_ON(__alignof__(struct bpf_async_kern) != __alignof__(struct bpf_wq));
3170 
3171 	if (flags)
3172 		return -EINVAL;
3173 
3174 	return __bpf_async_init(async, map, flags, BPF_ASYNC_TYPE_WQ);
3175 }
3176 
3177 __bpf_kfunc int bpf_wq_start(struct bpf_wq *wq, unsigned int flags)
3178 {
3179 	struct bpf_async_kern *async = (struct bpf_async_kern *)wq;
3180 	struct bpf_work *w;
3181 
3182 	if (flags)
3183 		return -EINVAL;
3184 
3185 	w = READ_ONCE(async->work);
3186 	if (!w || !READ_ONCE(w->cb.prog))
3187 		return -EINVAL;
3188 
3189 	if (!refcount_inc_not_zero(&w->cb.refcnt))
3190 		return -ENOENT;
3191 
3192 	if (!defer_timer_wq_op()) {
3193 		schedule_work(&w->work);
3194 		bpf_async_refcount_put(&w->cb);
3195 		return 0;
3196 	} else {
3197 		return bpf_async_schedule_op(&w->cb, BPF_ASYNC_START, 0, 0);
3198 	}
3199 }
3200 
3201 __bpf_kfunc int bpf_wq_set_callback(struct bpf_wq *wq,
3202 				    int (callback_fn)(void *map, int *key, void *value),
3203 				    unsigned int flags,
3204 				    struct bpf_prog_aux *aux)
3205 {
3206 	struct bpf_async_kern *async = (struct bpf_async_kern *)wq;
3207 
3208 	if (flags)
3209 		return -EINVAL;
3210 
3211 	return __bpf_async_set_callback(async, callback_fn, aux->prog);
3212 }
3213 
3214 __bpf_kfunc void bpf_preempt_disable(void)
3215 {
3216 	preempt_disable();
3217 }
3218 
3219 __bpf_kfunc void bpf_preempt_enable(void)
3220 {
3221 	preempt_enable();
3222 }
3223 
3224 struct bpf_iter_bits {
3225 	__u64 __opaque[2];
3226 } __aligned(8);
3227 
3228 #define BITS_ITER_NR_WORDS_MAX 511
3229 
3230 struct bpf_iter_bits_kern {
3231 	union {
3232 		__u64 *bits;
3233 		__u64 bits_copy;
3234 	};
3235 	int nr_bits;
3236 	int bit;
3237 } __aligned(8);
3238 
3239 /* On 64-bit hosts, unsigned long and u64 have the same size, so passing
3240  * a u64 pointer and an unsigned long pointer to find_next_bit() will
3241  * return the same result, as both point to the same 8-byte area.
3242  *
3243  * For 32-bit little-endian hosts, using a u64 pointer or unsigned long
3244  * pointer also makes no difference. This is because the first iterated
3245  * unsigned long is composed of bits 0-31 of the u64 and the second unsigned
3246  * long is composed of bits 32-63 of the u64.
3247  *
3248  * However, for 32-bit big-endian hosts, this is not the case. The first
3249  * iterated unsigned long will be bits 32-63 of the u64, so swap these two
3250  * ulong values within the u64.
3251  */
3252 static void swap_ulong_in_u64(u64 *bits, unsigned int nr)
3253 {
3254 #if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN)
3255 	unsigned int i;
3256 
3257 	for (i = 0; i < nr; i++)
3258 		bits[i] = (bits[i] >> 32) | ((u64)(u32)bits[i] << 32);
3259 #endif
3260 }
3261 
3262 /**
3263  * bpf_iter_bits_new() - Initialize a new bits iterator for a given memory area
3264  * @it: The new bpf_iter_bits to be created
3265  * @unsafe_ptr__ign: A pointer pointing to a memory area to be iterated over
3266  * @nr_words: The size of the specified memory area, measured in 8-byte units.
3267  * The maximum value of @nr_words is @BITS_ITER_NR_WORDS_MAX. This limit may be
3268  * further reduced by the BPF memory allocator implementation.
3269  *
3270  * This function initializes a new bpf_iter_bits structure for iterating over
3271  * a memory area which is specified by the @unsafe_ptr__ign and @nr_words. It
3272  * copies the data of the memory area to the newly created bpf_iter_bits @it for
3273  * subsequent iteration operations.
3274  *
3275  * On success, 0 is returned. On failure, ERR is returned.
3276  */
3277 __bpf_kfunc int
3278 bpf_iter_bits_new(struct bpf_iter_bits *it, const u64 *unsafe_ptr__ign, u32 nr_words)
3279 {
3280 	struct bpf_iter_bits_kern *kit = (void *)it;
3281 	u32 nr_bytes = nr_words * sizeof(u64);
3282 	u32 nr_bits = BYTES_TO_BITS(nr_bytes);
3283 	int err;
3284 
3285 	BUILD_BUG_ON(sizeof(struct bpf_iter_bits_kern) != sizeof(struct bpf_iter_bits));
3286 	BUILD_BUG_ON(__alignof__(struct bpf_iter_bits_kern) !=
3287 		     __alignof__(struct bpf_iter_bits));
3288 
3289 	kit->nr_bits = 0;
3290 	kit->bits_copy = 0;
3291 	kit->bit = -1;
3292 
3293 	if (!unsafe_ptr__ign || !nr_words)
3294 		return -EINVAL;
3295 	if (nr_words > BITS_ITER_NR_WORDS_MAX)
3296 		return -E2BIG;
3297 
3298 	/* Optimization for u64 mask */
3299 	if (nr_bits == 64) {
3300 		err = bpf_probe_read_kernel_common(&kit->bits_copy, nr_bytes, unsafe_ptr__ign);
3301 		if (err)
3302 			return -EFAULT;
3303 
3304 		swap_ulong_in_u64(&kit->bits_copy, nr_words);
3305 
3306 		kit->nr_bits = nr_bits;
3307 		return 0;
3308 	}
3309 
3310 	if (bpf_mem_alloc_check_size(false, nr_bytes))
3311 		return -E2BIG;
3312 
3313 	/* Fallback to memalloc */
3314 	kit->bits = bpf_mem_alloc(&bpf_global_ma, nr_bytes);
3315 	if (!kit->bits)
3316 		return -ENOMEM;
3317 
3318 	err = bpf_probe_read_kernel_common(kit->bits, nr_bytes, unsafe_ptr__ign);
3319 	if (err) {
3320 		bpf_mem_free(&bpf_global_ma, kit->bits);
3321 		return err;
3322 	}
3323 
3324 	swap_ulong_in_u64(kit->bits, nr_words);
3325 
3326 	kit->nr_bits = nr_bits;
3327 	return 0;
3328 }
3329 
3330 /**
3331  * bpf_iter_bits_next() - Get the next bit in a bpf_iter_bits
3332  * @it: The bpf_iter_bits to be checked
3333  *
3334  * This function returns a pointer to a number representing the value of the
3335  * next bit in the bits.
3336  *
3337  * If there are no further bits available, it returns NULL.
3338  */
3339 __bpf_kfunc int *bpf_iter_bits_next(struct bpf_iter_bits *it)
3340 {
3341 	struct bpf_iter_bits_kern *kit = (void *)it;
3342 	int bit = kit->bit, nr_bits = kit->nr_bits;
3343 	const void *bits;
3344 
3345 	if (!nr_bits || bit >= nr_bits)
3346 		return NULL;
3347 
3348 	bits = nr_bits == 64 ? &kit->bits_copy : kit->bits;
3349 	bit = find_next_bit(bits, nr_bits, bit + 1);
3350 	if (bit >= nr_bits) {
3351 		kit->bit = bit;
3352 		return NULL;
3353 	}
3354 
3355 	kit->bit = bit;
3356 	return &kit->bit;
3357 }
3358 
3359 /**
3360  * bpf_iter_bits_destroy() - Destroy a bpf_iter_bits
3361  * @it: The bpf_iter_bits to be destroyed
3362  *
3363  * Destroy the resource associated with the bpf_iter_bits.
3364  */
3365 __bpf_kfunc void bpf_iter_bits_destroy(struct bpf_iter_bits *it)
3366 {
3367 	struct bpf_iter_bits_kern *kit = (void *)it;
3368 
3369 	if (kit->nr_bits <= 64)
3370 		return;
3371 	bpf_mem_free(&bpf_global_ma, kit->bits);
3372 }
3373 
3374 /**
3375  * bpf_copy_from_user_str() - Copy a string from an unsafe user address
3376  * @dst:             Destination address, in kernel space.  This buffer must be
3377  *                   at least @dst__sz bytes long.
3378  * @dst__sz:         Maximum number of bytes to copy, includes the trailing NUL.
3379  * @unsafe_ptr__ign: Source address, in user space.
3380  * @flags:           The only supported flag is BPF_F_PAD_ZEROS
3381  *
3382  * Copies a NUL-terminated string from userspace to BPF space. If user string is
3383  * too long this will still ensure zero termination in the dst buffer unless
3384  * buffer size is 0.
3385  *
3386  * If BPF_F_PAD_ZEROS flag is set, memset the tail of @dst to 0 on success and
3387  * memset all of @dst on failure.
3388  */
3389 __bpf_kfunc int bpf_copy_from_user_str(void *dst, u32 dst__sz, const void __user *unsafe_ptr__ign, u64 flags)
3390 {
3391 	int ret;
3392 
3393 	if (unlikely(flags & ~BPF_F_PAD_ZEROS))
3394 		return -EINVAL;
3395 
3396 	if (unlikely(!dst__sz))
3397 		return 0;
3398 
3399 	ret = strncpy_from_user(dst, unsafe_ptr__ign, dst__sz - 1);
3400 	if (ret < 0) {
3401 		if (flags & BPF_F_PAD_ZEROS)
3402 			memset((char *)dst, 0, dst__sz);
3403 
3404 		return ret;
3405 	}
3406 
3407 	if (flags & BPF_F_PAD_ZEROS)
3408 		memset((char *)dst + ret, 0, dst__sz - ret);
3409 	else
3410 		((char *)dst)[ret] = '\0';
3411 
3412 	return ret + 1;
3413 }
3414 
3415 /**
3416  * bpf_copy_from_user_task_str() - Copy a string from an task's address space
3417  * @dst:             Destination address, in kernel space.  This buffer must be
3418  *                   at least @dst__sz bytes long.
3419  * @dst__sz:         Maximum number of bytes to copy, includes the trailing NUL.
3420  * @unsafe_ptr__ign: Source address in the task's address space.
3421  * @tsk:             The task whose address space will be used
3422  * @flags:           The only supported flag is BPF_F_PAD_ZEROS
3423  *
3424  * Copies a NUL terminated string from a task's address space to @dst__sz
3425  * buffer. If user string is too long this will still ensure zero termination
3426  * in the @dst__sz buffer unless buffer size is 0.
3427  *
3428  * If BPF_F_PAD_ZEROS flag is set, memset the tail of @dst__sz to 0 on success
3429  * and memset all of @dst__sz on failure.
3430  *
3431  * Return: The number of copied bytes on success including the NUL terminator.
3432  * A negative error code on failure.
3433  */
3434 __bpf_kfunc int bpf_copy_from_user_task_str(void *dst, u32 dst__sz,
3435 					    const void __user *unsafe_ptr__ign,
3436 					    struct task_struct *tsk, u64 flags)
3437 {
3438 	int ret;
3439 
3440 	if (unlikely(flags & ~BPF_F_PAD_ZEROS))
3441 		return -EINVAL;
3442 
3443 	if (unlikely(dst__sz == 0))
3444 		return 0;
3445 
3446 	ret = copy_remote_vm_str(tsk, (unsigned long)unsafe_ptr__ign, dst, dst__sz, 0);
3447 	if (ret < 0) {
3448 		if (flags & BPF_F_PAD_ZEROS)
3449 			memset(dst, 0, dst__sz);
3450 		return ret;
3451 	}
3452 
3453 	if (flags & BPF_F_PAD_ZEROS)
3454 		memset(dst + ret, 0, dst__sz - ret);
3455 
3456 	return ret + 1;
3457 }
3458 
3459 /* Keep unsinged long in prototype so that kfunc is usable when emitted to
3460  * vmlinux.h in BPF programs directly, but note that while in BPF prog, the
3461  * unsigned long always points to 8-byte region on stack, the kernel may only
3462  * read and write the 4-bytes on 32-bit.
3463  */
3464 __bpf_kfunc void bpf_local_irq_save(unsigned long *flags__irq_flag)
3465 {
3466 	local_irq_save(*flags__irq_flag);
3467 }
3468 
3469 __bpf_kfunc void bpf_local_irq_restore(unsigned long *flags__irq_flag)
3470 {
3471 	local_irq_restore(*flags__irq_flag);
3472 }
3473 
3474 __bpf_kfunc void __bpf_trap(void)
3475 {
3476 }
3477 
3478 /*
3479  * Kfuncs for string operations.
3480  *
3481  * Since strings are not necessarily %NUL-terminated, we cannot directly call
3482  * in-kernel implementations. Instead, we open-code the implementations using
3483  * __get_kernel_nofault instead of plain dereference to make them safe.
3484  */
3485 
3486 static int __bpf_strncasecmp(const char *s1, const char *s2, bool ignore_case, size_t len)
3487 {
3488 	char c1, c2;
3489 	int i;
3490 
3491 	if (!copy_from_kernel_nofault_allowed(s1, 1) ||
3492 	    !copy_from_kernel_nofault_allowed(s2, 1)) {
3493 		return -ERANGE;
3494 	}
3495 
3496 	guard(pagefault)();
3497 	for (i = 0; i < len && i < XATTR_SIZE_MAX; i++) {
3498 		__get_kernel_nofault(&c1, s1, char, err_out);
3499 		__get_kernel_nofault(&c2, s2, char, err_out);
3500 		if (ignore_case) {
3501 			c1 = tolower(c1);
3502 			c2 = tolower(c2);
3503 		}
3504 		if (c1 != c2)
3505 			return c1 < c2 ? -1 : 1;
3506 		if (c1 == '\0')
3507 			return 0;
3508 		s1++;
3509 		s2++;
3510 	}
3511 	return i == XATTR_SIZE_MAX ? -E2BIG : 0;
3512 err_out:
3513 	return -EFAULT;
3514 }
3515 
3516 /**
3517  * bpf_strcmp - Compare two strings
3518  * @s1__ign: One string
3519  * @s2__ign: Another string
3520  *
3521  * Return:
3522  * * %0       - Strings are equal
3523  * * %-1      - @s1__ign is smaller
3524  * * %1       - @s2__ign is smaller
3525  * * %-EFAULT - Cannot read one of the strings
3526  * * %-E2BIG  - One of strings is too large
3527  * * %-ERANGE - One of strings is outside of kernel address space
3528  */
3529 __bpf_kfunc int bpf_strcmp(const char *s1__ign, const char *s2__ign)
3530 {
3531 	return __bpf_strncasecmp(s1__ign, s2__ign, false, XATTR_SIZE_MAX);
3532 }
3533 
3534 /**
3535  * bpf_strcasecmp - Compare two strings, ignoring the case of the characters
3536  * @s1__ign: One string
3537  * @s2__ign: Another string
3538  *
3539  * Return:
3540  * * %0       - Strings are equal
3541  * * %-1      - @s1__ign is smaller
3542  * * %1       - @s2__ign is smaller
3543  * * %-EFAULT - Cannot read one of the strings
3544  * * %-E2BIG  - One of strings is too large
3545  * * %-ERANGE - One of strings is outside of kernel address space
3546  */
3547 __bpf_kfunc int bpf_strcasecmp(const char *s1__ign, const char *s2__ign)
3548 {
3549 	return __bpf_strncasecmp(s1__ign, s2__ign, true, XATTR_SIZE_MAX);
3550 }
3551 
3552 /*
3553  * bpf_strncasecmp - Compare two length-limited strings, ignoring case
3554  * @s1__ign: One string
3555  * @s2__ign: Another string
3556  * @len: The maximum number of characters to compare
3557  *
3558  * Return:
3559  * * %0       - Strings are equal
3560  * * %-1      - @s1__ign is smaller
3561  * * %1       - @s2__ign is smaller
3562  * * %-EFAULT - Cannot read one of the strings
3563  * * %-E2BIG  - One of strings is too large
3564  * * %-ERANGE - One of strings is outside of kernel address space
3565  */
3566 __bpf_kfunc int bpf_strncasecmp(const char *s1__ign, const char *s2__ign, size_t len)
3567 {
3568 	return __bpf_strncasecmp(s1__ign, s2__ign, true, len);
3569 }
3570 
3571 /**
3572  * bpf_strnchr - Find a character in a length limited string
3573  * @s__ign: The string to be searched
3574  * @count: The number of characters to be searched
3575  * @c: The character to search for
3576  *
3577  * Note that the %NUL-terminator is considered part of the string, and can
3578  * be searched for.
3579  *
3580  * Return:
3581  * * >=0      - Index of the first occurrence of @c within @s__ign
3582  * * %-ENOENT - @c not found in the first @count characters of @s__ign
3583  * * %-EFAULT - Cannot read @s__ign
3584  * * %-E2BIG  - @s__ign is too large
3585  * * %-ERANGE - @s__ign is outside of kernel address space
3586  */
3587 __bpf_kfunc int bpf_strnchr(const char *s__ign, size_t count, char c)
3588 {
3589 	char sc;
3590 	int i;
3591 
3592 	if (!copy_from_kernel_nofault_allowed(s__ign, 1))
3593 		return -ERANGE;
3594 
3595 	guard(pagefault)();
3596 	for (i = 0; i < count && i < XATTR_SIZE_MAX; i++) {
3597 		__get_kernel_nofault(&sc, s__ign, char, err_out);
3598 		if (sc == c)
3599 			return i;
3600 		if (sc == '\0')
3601 			return -ENOENT;
3602 		s__ign++;
3603 	}
3604 	return i == XATTR_SIZE_MAX ? -E2BIG : -ENOENT;
3605 err_out:
3606 	return -EFAULT;
3607 }
3608 
3609 /**
3610  * bpf_strchr - Find the first occurrence of a character in a string
3611  * @s__ign: The string to be searched
3612  * @c: The character to search for
3613  *
3614  * Note that the %NUL-terminator is considered part of the string, and can
3615  * be searched for.
3616  *
3617  * Return:
3618  * * >=0      - The index of the first occurrence of @c within @s__ign
3619  * * %-ENOENT - @c not found in @s__ign
3620  * * %-EFAULT - Cannot read @s__ign
3621  * * %-E2BIG  - @s__ign is too large
3622  * * %-ERANGE - @s__ign is outside of kernel address space
3623  */
3624 __bpf_kfunc int bpf_strchr(const char *s__ign, char c)
3625 {
3626 	return bpf_strnchr(s__ign, XATTR_SIZE_MAX, c);
3627 }
3628 
3629 /**
3630  * bpf_strchrnul - Find and return a character in a string, or end of string
3631  * @s__ign: The string to be searched
3632  * @c: The character to search for
3633  *
3634  * Return:
3635  * * >=0      - Index of the first occurrence of @c within @s__ign or index of
3636  *              the null byte at the end of @s__ign when @c is not found
3637  * * %-EFAULT - Cannot read @s__ign
3638  * * %-E2BIG  - @s__ign is too large
3639  * * %-ERANGE - @s__ign is outside of kernel address space
3640  */
3641 __bpf_kfunc int bpf_strchrnul(const char *s__ign, char c)
3642 {
3643 	char sc;
3644 	int i;
3645 
3646 	if (!copy_from_kernel_nofault_allowed(s__ign, 1))
3647 		return -ERANGE;
3648 
3649 	guard(pagefault)();
3650 	for (i = 0; i < XATTR_SIZE_MAX; i++) {
3651 		__get_kernel_nofault(&sc, s__ign, char, err_out);
3652 		if (sc == '\0' || sc == c)
3653 			return i;
3654 		s__ign++;
3655 	}
3656 	return -E2BIG;
3657 err_out:
3658 	return -EFAULT;
3659 }
3660 
3661 /**
3662  * bpf_strrchr - Find the last occurrence of a character in a string
3663  * @s__ign: The string to be searched
3664  * @c: The character to search for
3665  *
3666  * Return:
3667  * * >=0      - Index of the last occurrence of @c within @s__ign
3668  * * %-ENOENT - @c not found in @s__ign
3669  * * %-EFAULT - Cannot read @s__ign
3670  * * %-E2BIG  - @s__ign is too large
3671  * * %-ERANGE - @s__ign is outside of kernel address space
3672  */
3673 __bpf_kfunc int bpf_strrchr(const char *s__ign, int c)
3674 {
3675 	char sc;
3676 	int i, last = -ENOENT;
3677 
3678 	if (!copy_from_kernel_nofault_allowed(s__ign, 1))
3679 		return -ERANGE;
3680 
3681 	guard(pagefault)();
3682 	for (i = 0; i < XATTR_SIZE_MAX; i++) {
3683 		__get_kernel_nofault(&sc, s__ign, char, err_out);
3684 		if (sc == c)
3685 			last = i;
3686 		if (sc == '\0')
3687 			return last;
3688 		s__ign++;
3689 	}
3690 	return -E2BIG;
3691 err_out:
3692 	return -EFAULT;
3693 }
3694 
3695 /**
3696  * bpf_strnlen - Calculate the length of a length-limited string
3697  * @s__ign: The string
3698  * @count: The maximum number of characters to count
3699  *
3700  * Return:
3701  * * >=0      - The length of @s__ign
3702  * * %-EFAULT - Cannot read @s__ign
3703  * * %-E2BIG  - @s__ign is too large
3704  * * %-ERANGE - @s__ign is outside of kernel address space
3705  */
3706 __bpf_kfunc int bpf_strnlen(const char *s__ign, size_t count)
3707 {
3708 	char c;
3709 	int i;
3710 
3711 	if (!copy_from_kernel_nofault_allowed(s__ign, 1))
3712 		return -ERANGE;
3713 
3714 	guard(pagefault)();
3715 	for (i = 0; i < count && i < XATTR_SIZE_MAX; i++) {
3716 		__get_kernel_nofault(&c, s__ign, char, err_out);
3717 		if (c == '\0')
3718 			return i;
3719 		s__ign++;
3720 	}
3721 	return i == XATTR_SIZE_MAX ? -E2BIG : i;
3722 err_out:
3723 	return -EFAULT;
3724 }
3725 
3726 /**
3727  * bpf_strlen - Calculate the length of a string
3728  * @s__ign: The string
3729  *
3730  * Return:
3731  * * >=0      - The length of @s__ign
3732  * * %-EFAULT - Cannot read @s__ign
3733  * * %-E2BIG  - @s__ign is too large
3734  * * %-ERANGE - @s__ign is outside of kernel address space
3735  */
3736 __bpf_kfunc int bpf_strlen(const char *s__ign)
3737 {
3738 	return bpf_strnlen(s__ign, XATTR_SIZE_MAX);
3739 }
3740 
3741 /**
3742  * bpf_strspn - Calculate the length of the initial substring of @s__ign which
3743  *              only contains letters in @accept__ign
3744  * @s__ign: The string to be searched
3745  * @accept__ign: The string to search for
3746  *
3747  * Return:
3748  * * >=0      - The length of the initial substring of @s__ign which only
3749  *              contains letters from @accept__ign
3750  * * %-EFAULT - Cannot read one of the strings
3751  * * %-E2BIG  - One of the strings is too large
3752  * * %-ERANGE - One of the strings is outside of kernel address space
3753  */
3754 __bpf_kfunc int bpf_strspn(const char *s__ign, const char *accept__ign)
3755 {
3756 	char cs, ca;
3757 	int i, j;
3758 
3759 	if (!copy_from_kernel_nofault_allowed(s__ign, 1) ||
3760 	    !copy_from_kernel_nofault_allowed(accept__ign, 1)) {
3761 		return -ERANGE;
3762 	}
3763 
3764 	guard(pagefault)();
3765 	for (i = 0; i < XATTR_SIZE_MAX; i++) {
3766 		__get_kernel_nofault(&cs, s__ign, char, err_out);
3767 		if (cs == '\0')
3768 			return i;
3769 		for (j = 0; j < XATTR_SIZE_MAX; j++) {
3770 			__get_kernel_nofault(&ca, accept__ign + j, char, err_out);
3771 			if (cs == ca || ca == '\0')
3772 				break;
3773 		}
3774 		if (j == XATTR_SIZE_MAX)
3775 			return -E2BIG;
3776 		if (ca == '\0')
3777 			return i;
3778 		s__ign++;
3779 	}
3780 	return -E2BIG;
3781 err_out:
3782 	return -EFAULT;
3783 }
3784 
3785 /**
3786  * bpf_strcspn - Calculate the length of the initial substring of @s__ign which
3787  *               does not contain letters in @reject__ign
3788  * @s__ign: The string to be searched
3789  * @reject__ign: The string to search for
3790  *
3791  * Return:
3792  * * >=0      - The length of the initial substring of @s__ign which does not
3793  *              contain letters from @reject__ign
3794  * * %-EFAULT - Cannot read one of the strings
3795  * * %-E2BIG  - One of the strings is too large
3796  * * %-ERANGE - One of the strings is outside of kernel address space
3797  */
3798 __bpf_kfunc int bpf_strcspn(const char *s__ign, const char *reject__ign)
3799 {
3800 	char cs, cr;
3801 	int i, j;
3802 
3803 	if (!copy_from_kernel_nofault_allowed(s__ign, 1) ||
3804 	    !copy_from_kernel_nofault_allowed(reject__ign, 1)) {
3805 		return -ERANGE;
3806 	}
3807 
3808 	guard(pagefault)();
3809 	for (i = 0; i < XATTR_SIZE_MAX; i++) {
3810 		__get_kernel_nofault(&cs, s__ign, char, err_out);
3811 		if (cs == '\0')
3812 			return i;
3813 		for (j = 0; j < XATTR_SIZE_MAX; j++) {
3814 			__get_kernel_nofault(&cr, reject__ign + j, char, err_out);
3815 			if (cs == cr || cr == '\0')
3816 				break;
3817 		}
3818 		if (j == XATTR_SIZE_MAX)
3819 			return -E2BIG;
3820 		if (cr != '\0')
3821 			return i;
3822 		s__ign++;
3823 	}
3824 	return -E2BIG;
3825 err_out:
3826 	return -EFAULT;
3827 }
3828 
3829 static int __bpf_strnstr(const char *s1, const char *s2, size_t len,
3830 			 bool ignore_case)
3831 {
3832 	char c1, c2;
3833 	int i, j;
3834 
3835 	if (!copy_from_kernel_nofault_allowed(s1, 1) ||
3836 	    !copy_from_kernel_nofault_allowed(s2, 1)) {
3837 		return -ERANGE;
3838 	}
3839 
3840 	guard(pagefault)();
3841 	for (i = 0; i < XATTR_SIZE_MAX; i++) {
3842 		for (j = 0; i + j <= len && j < XATTR_SIZE_MAX; j++) {
3843 			__get_kernel_nofault(&c2, s2 + j, char, err_out);
3844 			if (c2 == '\0')
3845 				return i;
3846 			/*
3847 			 * We allow reading an extra byte from s2 (note the
3848 			 * `i + j <= len` above) to cover the case when s2 is
3849 			 * a suffix of the first len chars of s1.
3850 			 */
3851 			if (i + j == len)
3852 				break;
3853 			__get_kernel_nofault(&c1, s1 + j, char, err_out);
3854 
3855 			if (ignore_case) {
3856 				c1 = tolower(c1);
3857 				c2 = tolower(c2);
3858 			}
3859 
3860 			if (c1 == '\0')
3861 				return -ENOENT;
3862 			if (c1 != c2)
3863 				break;
3864 		}
3865 		if (j == XATTR_SIZE_MAX)
3866 			return -E2BIG;
3867 		if (i + j == len)
3868 			return -ENOENT;
3869 		s1++;
3870 	}
3871 	return -E2BIG;
3872 err_out:
3873 	return -EFAULT;
3874 }
3875 
3876 /**
3877  * bpf_strstr - Find the first substring in a string
3878  * @s1__ign: The string to be searched
3879  * @s2__ign: The string to search for
3880  *
3881  * Return:
3882  * * >=0      - Index of the first character of the first occurrence of @s2__ign
3883  *              within @s1__ign
3884  * * %-ENOENT - @s2__ign is not a substring of @s1__ign
3885  * * %-EFAULT - Cannot read one of the strings
3886  * * %-E2BIG  - One of the strings is too large
3887  * * %-ERANGE - One of the strings is outside of kernel address space
3888  */
3889 __bpf_kfunc int bpf_strstr(const char *s1__ign, const char *s2__ign)
3890 {
3891 	return __bpf_strnstr(s1__ign, s2__ign, XATTR_SIZE_MAX, false);
3892 }
3893 
3894 /**
3895  * bpf_strcasestr - Find the first substring in a string, ignoring the case of
3896  *                  the characters
3897  * @s1__ign: The string to be searched
3898  * @s2__ign: The string to search for
3899  *
3900  * Return:
3901  * * >=0      - Index of the first character of the first occurrence of @s2__ign
3902  *              within @s1__ign
3903  * * %-ENOENT - @s2__ign is not a substring of @s1__ign
3904  * * %-EFAULT - Cannot read one of the strings
3905  * * %-E2BIG  - One of the strings is too large
3906  * * %-ERANGE - One of the strings is outside of kernel address space
3907  */
3908 __bpf_kfunc int bpf_strcasestr(const char *s1__ign, const char *s2__ign)
3909 {
3910 	return __bpf_strnstr(s1__ign, s2__ign, XATTR_SIZE_MAX, true);
3911 }
3912 
3913 /**
3914  * bpf_strnstr - Find the first substring in a length-limited string
3915  * @s1__ign: The string to be searched
3916  * @s2__ign: The string to search for
3917  * @len: the maximum number of characters to search
3918  *
3919  * Return:
3920  * * >=0      - Index of the first character of the first occurrence of @s2__ign
3921  *              within the first @len characters of @s1__ign
3922  * * %-ENOENT - @s2__ign not found in the first @len characters of @s1__ign
3923  * * %-EFAULT - Cannot read one of the strings
3924  * * %-E2BIG  - One of the strings is too large
3925  * * %-ERANGE - One of the strings is outside of kernel address space
3926  */
3927 __bpf_kfunc int bpf_strnstr(const char *s1__ign, const char *s2__ign,
3928 			    size_t len)
3929 {
3930 	return __bpf_strnstr(s1__ign, s2__ign, len, false);
3931 }
3932 
3933 /**
3934  * bpf_strncasestr - Find the first substring in a length-limited string,
3935  *                   ignoring the case of the characters
3936  * @s1__ign: The string to be searched
3937  * @s2__ign: The string to search for
3938  * @len: the maximum number of characters to search
3939  *
3940  * Return:
3941  * * >=0      - Index of the first character of the first occurrence of @s2__ign
3942  *              within the first @len characters of @s1__ign
3943  * * %-ENOENT - @s2__ign not found in the first @len characters of @s1__ign
3944  * * %-EFAULT - Cannot read one of the strings
3945  * * %-E2BIG  - One of the strings is too large
3946  * * %-ERANGE - One of the strings is outside of kernel address space
3947  */
3948 __bpf_kfunc int bpf_strncasestr(const char *s1__ign, const char *s2__ign,
3949 				size_t len)
3950 {
3951 	return __bpf_strnstr(s1__ign, s2__ign, len, true);
3952 }
3953 
3954 #ifdef CONFIG_KEYS
3955 /**
3956  * bpf_lookup_user_key - lookup a key by its serial
3957  * @serial: key handle serial number
3958  * @flags: lookup-specific flags
3959  *
3960  * Search a key with a given *serial* and the provided *flags*.
3961  * If found, increment the reference count of the key by one, and
3962  * return it in the bpf_key structure.
3963  *
3964  * The bpf_key structure must be passed to bpf_key_put() when done
3965  * with it, so that the key reference count is decremented and the
3966  * bpf_key structure is freed.
3967  *
3968  * Permission checks are deferred to the time the key is used by
3969  * one of the available key-specific kfuncs.
3970  *
3971  * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
3972  * special keyring (e.g. session keyring), if it doesn't yet exist.
3973  * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
3974  * for the key construction, and to retrieve uninstantiated keys (keys
3975  * without data attached to them).
3976  *
3977  * Return: a bpf_key pointer with a valid key pointer if the key is found, a
3978  *         NULL pointer otherwise.
3979  */
3980 __bpf_kfunc struct bpf_key *bpf_lookup_user_key(s32 serial, u64 flags)
3981 {
3982 	key_ref_t key_ref;
3983 	struct bpf_key *bkey;
3984 
3985 	if (flags & ~KEY_LOOKUP_ALL)
3986 		return NULL;
3987 
3988 	/*
3989 	 * Permission check is deferred until the key is used, as the
3990 	 * intent of the caller is unknown here.
3991 	 */
3992 	key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
3993 	if (IS_ERR(key_ref))
3994 		return NULL;
3995 
3996 	bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
3997 	if (!bkey) {
3998 		key_put(key_ref_to_ptr(key_ref));
3999 		return NULL;
4000 	}
4001 
4002 	bkey->key = key_ref_to_ptr(key_ref);
4003 	bkey->has_ref = true;
4004 
4005 	return bkey;
4006 }
4007 
4008 /**
4009  * bpf_lookup_system_key - lookup a key by a system-defined ID
4010  * @id: key ID
4011  *
4012  * Obtain a bpf_key structure with a key pointer set to the passed key ID.
4013  * The key pointer is marked as invalid, to prevent bpf_key_put() from
4014  * attempting to decrement the key reference count on that pointer. The key
4015  * pointer set in such way is currently understood only by
4016  * verify_pkcs7_signature().
4017  *
4018  * Set *id* to one of the values defined in include/linux/verification.h:
4019  * 0 for the primary keyring (immutable keyring of system keys);
4020  * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
4021  * (where keys can be added only if they are vouched for by existing keys
4022  * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
4023  * keyring (primarily used by the integrity subsystem to verify a kexec'ed
4024  * kerned image and, possibly, the initramfs signature).
4025  *
4026  * Return: a bpf_key pointer with an invalid key pointer set from the
4027  *         pre-determined ID on success, a NULL pointer otherwise
4028  */
4029 __bpf_kfunc struct bpf_key *bpf_lookup_system_key(u64 id)
4030 {
4031 	struct bpf_key *bkey;
4032 
4033 	if (system_keyring_id_check(id) < 0)
4034 		return NULL;
4035 
4036 	bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
4037 	if (!bkey)
4038 		return NULL;
4039 
4040 	bkey->key = (struct key *)(unsigned long)id;
4041 	bkey->has_ref = false;
4042 
4043 	return bkey;
4044 }
4045 
4046 /**
4047  * bpf_key_put - decrement key reference count if key is valid and free bpf_key
4048  * @bkey: bpf_key structure
4049  *
4050  * Decrement the reference count of the key inside *bkey*, if the pointer
4051  * is valid, and free *bkey*.
4052  */
4053 __bpf_kfunc void bpf_key_put(struct bpf_key *bkey)
4054 {
4055 	if (bkey->has_ref)
4056 		key_put(bkey->key);
4057 
4058 	kfree(bkey);
4059 }
4060 
4061 /**
4062  * bpf_verify_pkcs7_signature - verify a PKCS#7 signature
4063  * @data_p: data to verify
4064  * @sig_p: signature of the data
4065  * @trusted_keyring: keyring with keys trusted for signature verification
4066  *
4067  * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
4068  * with keys in a keyring referenced by *trusted_keyring*.
4069  *
4070  * Return: 0 on success, a negative value on error.
4071  */
4072 __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_p,
4073 			       struct bpf_dynptr *sig_p,
4074 			       struct bpf_key *trusted_keyring)
4075 {
4076 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
4077 	struct bpf_dynptr_kern *data_ptr = (struct bpf_dynptr_kern *)data_p;
4078 	struct bpf_dynptr_kern *sig_ptr = (struct bpf_dynptr_kern *)sig_p;
4079 	const void *data, *sig;
4080 	u32 data_len, sig_len;
4081 	int ret;
4082 
4083 	if (trusted_keyring->has_ref) {
4084 		/*
4085 		 * Do the permission check deferred in bpf_lookup_user_key().
4086 		 * See bpf_lookup_user_key() for more details.
4087 		 *
4088 		 * A call to key_task_permission() here would be redundant, as
4089 		 * it is already done by keyring_search() called by
4090 		 * find_asymmetric_key().
4091 		 */
4092 		ret = key_validate(trusted_keyring->key);
4093 		if (ret < 0)
4094 			return ret;
4095 	}
4096 
4097 	data_len = __bpf_dynptr_size(data_ptr);
4098 	data = __bpf_dynptr_data(data_ptr, data_len);
4099 	sig_len = __bpf_dynptr_size(sig_ptr);
4100 	sig = __bpf_dynptr_data(sig_ptr, sig_len);
4101 
4102 	return verify_pkcs7_signature(data, data_len, sig, sig_len,
4103 				      trusted_keyring->key,
4104 				      VERIFYING_BPF_SIGNATURE, NULL,
4105 				      NULL);
4106 #else
4107 	return -EOPNOTSUPP;
4108 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
4109 }
4110 #endif /* CONFIG_KEYS */
4111 
4112 typedef int (*bpf_task_work_callback_t)(struct bpf_map *map, void *key, void *value);
4113 
4114 enum bpf_task_work_state {
4115 	/* bpf_task_work is ready to be used */
4116 	BPF_TW_STANDBY = 0,
4117 	/* irq work scheduling in progress */
4118 	BPF_TW_PENDING,
4119 	/* task work scheduling in progress */
4120 	BPF_TW_SCHEDULING,
4121 	/* task work is scheduled successfully */
4122 	BPF_TW_SCHEDULED,
4123 	/* callback is running */
4124 	BPF_TW_RUNNING,
4125 	/* associated BPF map value is deleted */
4126 	BPF_TW_FREED,
4127 };
4128 
4129 struct bpf_task_work_ctx {
4130 	enum bpf_task_work_state state;
4131 	refcount_t refcnt;
4132 	struct callback_head work;
4133 	struct irq_work irq_work;
4134 	/* bpf_prog that schedules task work */
4135 	struct bpf_prog *prog;
4136 	/* task for which callback is scheduled */
4137 	struct task_struct *task;
4138 	/* the map and map value associated with this context */
4139 	struct bpf_map *map;
4140 	void *map_val;
4141 	enum task_work_notify_mode mode;
4142 	bpf_task_work_callback_t callback_fn;
4143 	struct rcu_head rcu;
4144 } __aligned(8);
4145 
4146 /* Actual type for struct bpf_task_work */
4147 struct bpf_task_work_kern {
4148 	struct bpf_task_work_ctx *ctx;
4149 };
4150 
4151 static void bpf_task_work_ctx_reset(struct bpf_task_work_ctx *ctx)
4152 {
4153 	if (ctx->prog) {
4154 		bpf_prog_put(ctx->prog);
4155 		ctx->prog = NULL;
4156 	}
4157 	if (ctx->task) {
4158 		bpf_task_release(ctx->task);
4159 		ctx->task = NULL;
4160 	}
4161 }
4162 
4163 static bool bpf_task_work_ctx_tryget(struct bpf_task_work_ctx *ctx)
4164 {
4165 	return refcount_inc_not_zero(&ctx->refcnt);
4166 }
4167 
4168 static void bpf_task_work_ctx_put(struct bpf_task_work_ctx *ctx)
4169 {
4170 	if (!refcount_dec_and_test(&ctx->refcnt))
4171 		return;
4172 
4173 	bpf_task_work_ctx_reset(ctx);
4174 
4175 	/* bpf_mem_free expects migration to be disabled */
4176 	migrate_disable();
4177 	bpf_mem_free(&bpf_global_ma, ctx);
4178 	migrate_enable();
4179 }
4180 
4181 static void bpf_task_work_cancel(struct bpf_task_work_ctx *ctx)
4182 {
4183 	/*
4184 	 * Scheduled task_work callback holds ctx ref, so if we successfully
4185 	 * cancelled, we put that ref on callback's behalf. If we couldn't
4186 	 * cancel, callback will inevitably run or has already completed
4187 	 * running, and it would have taken care of its ctx ref itself.
4188 	 */
4189 	if (task_work_cancel(ctx->task, &ctx->work))
4190 		bpf_task_work_ctx_put(ctx);
4191 }
4192 
4193 static void bpf_task_work_callback(struct callback_head *cb)
4194 {
4195 	struct bpf_task_work_ctx *ctx = container_of(cb, struct bpf_task_work_ctx, work);
4196 	enum bpf_task_work_state state;
4197 	u32 idx;
4198 	void *key;
4199 
4200 	/* Read lock is needed to protect ctx and map key/value access */
4201 	guard(rcu_tasks_trace)();
4202 	/*
4203 	 * This callback may start running before bpf_task_work_irq() switched to
4204 	 * SCHEDULED state, so handle both transition variants SCHEDULING|SCHEDULED -> RUNNING.
4205 	 */
4206 	state = cmpxchg(&ctx->state, BPF_TW_SCHEDULING, BPF_TW_RUNNING);
4207 	if (state == BPF_TW_SCHEDULED)
4208 		state = cmpxchg(&ctx->state, BPF_TW_SCHEDULED, BPF_TW_RUNNING);
4209 	if (state == BPF_TW_FREED) {
4210 		bpf_task_work_ctx_put(ctx);
4211 		return;
4212 	}
4213 
4214 	key = (void *)map_key_from_value(ctx->map, ctx->map_val, &idx);
4215 
4216 	migrate_disable();
4217 	ctx->callback_fn(ctx->map, key, ctx->map_val);
4218 	migrate_enable();
4219 
4220 	bpf_task_work_ctx_reset(ctx);
4221 	(void)cmpxchg(&ctx->state, BPF_TW_RUNNING, BPF_TW_STANDBY);
4222 
4223 	bpf_task_work_ctx_put(ctx);
4224 }
4225 
4226 static void bpf_task_work_irq(struct irq_work *irq_work)
4227 {
4228 	struct bpf_task_work_ctx *ctx = container_of(irq_work, struct bpf_task_work_ctx, irq_work);
4229 	enum bpf_task_work_state state;
4230 	int err;
4231 
4232 	guard(rcu_tasks_trace)();
4233 
4234 	if (cmpxchg(&ctx->state, BPF_TW_PENDING, BPF_TW_SCHEDULING) != BPF_TW_PENDING) {
4235 		bpf_task_work_ctx_put(ctx);
4236 		return;
4237 	}
4238 
4239 	err = task_work_add(ctx->task, &ctx->work, ctx->mode);
4240 	if (err) {
4241 		bpf_task_work_ctx_reset(ctx);
4242 		/*
4243 		 * try to switch back to STANDBY for another task_work reuse, but we might have
4244 		 * gone to FREED already, which is fine as we already cleaned up after ourselves
4245 		 */
4246 		(void)cmpxchg(&ctx->state, BPF_TW_SCHEDULING, BPF_TW_STANDBY);
4247 		bpf_task_work_ctx_put(ctx);
4248 		return;
4249 	}
4250 
4251 	/*
4252 	 * It's technically possible for just scheduled task_work callback to
4253 	 * complete running by now, going SCHEDULING -> RUNNING and then
4254 	 * dropping its ctx refcount. Instead of capturing extra ref just to
4255 	 * protected below ctx->state access, we rely on RCU protection to
4256 	 * perform below SCHEDULING -> SCHEDULED attempt.
4257 	 */
4258 	state = cmpxchg(&ctx->state, BPF_TW_SCHEDULING, BPF_TW_SCHEDULED);
4259 	if (state == BPF_TW_FREED)
4260 		bpf_task_work_cancel(ctx); /* clean up if we switched into FREED state */
4261 }
4262 
4263 static struct bpf_task_work_ctx *bpf_task_work_fetch_ctx(struct bpf_task_work *tw,
4264 							 struct bpf_map *map)
4265 {
4266 	struct bpf_task_work_kern *twk = (void *)tw;
4267 	struct bpf_task_work_ctx *ctx, *old_ctx;
4268 
4269 	ctx = READ_ONCE(twk->ctx);
4270 	if (ctx)
4271 		return ctx;
4272 
4273 	ctx = bpf_mem_alloc(&bpf_global_ma, sizeof(struct bpf_task_work_ctx));
4274 	if (!ctx)
4275 		return ERR_PTR(-ENOMEM);
4276 
4277 	memset(ctx, 0, sizeof(*ctx));
4278 	refcount_set(&ctx->refcnt, 1); /* map's own ref */
4279 	ctx->state = BPF_TW_STANDBY;
4280 
4281 	old_ctx = cmpxchg(&twk->ctx, NULL, ctx);
4282 	if (old_ctx) {
4283 		/*
4284 		 * tw->ctx is set by concurrent BPF program, release allocated
4285 		 * memory and try to reuse already set context.
4286 		 */
4287 		bpf_mem_free(&bpf_global_ma, ctx);
4288 		return old_ctx;
4289 	}
4290 
4291 	return ctx; /* Success */
4292 }
4293 
4294 static struct bpf_task_work_ctx *bpf_task_work_acquire_ctx(struct bpf_task_work *tw,
4295 							   struct bpf_map *map)
4296 {
4297 	struct bpf_task_work_ctx *ctx;
4298 
4299 	ctx = bpf_task_work_fetch_ctx(tw, map);
4300 	if (IS_ERR(ctx))
4301 		return ctx;
4302 
4303 	/* try to get ref for task_work callback to hold */
4304 	if (!bpf_task_work_ctx_tryget(ctx))
4305 		return ERR_PTR(-EBUSY);
4306 
4307 	if (cmpxchg(&ctx->state, BPF_TW_STANDBY, BPF_TW_PENDING) != BPF_TW_STANDBY) {
4308 		/* lost acquiring race or map_release_uref() stole it from us, put ref and bail */
4309 		bpf_task_work_ctx_put(ctx);
4310 		return ERR_PTR(-EBUSY);
4311 	}
4312 
4313 	/*
4314 	 * If no process or bpffs is holding a reference to the map, no new callbacks should be
4315 	 * scheduled. This does not address any race or correctness issue, but rather is a policy
4316 	 * choice: dropping user references should stop everything.
4317 	 */
4318 	if (!atomic64_read(&map->usercnt)) {
4319 		/* drop ref we just got for task_work callback itself */
4320 		bpf_task_work_ctx_put(ctx);
4321 		/* transfer map's ref into cancel_and_free() */
4322 		bpf_task_work_cancel_and_free(tw);
4323 		return ERR_PTR(-EBUSY);
4324 	}
4325 
4326 	return ctx;
4327 }
4328 
4329 static int bpf_task_work_schedule(struct task_struct *task, struct bpf_task_work *tw,
4330 				  struct bpf_map *map, bpf_task_work_callback_t callback_fn,
4331 				  struct bpf_prog_aux *aux, enum task_work_notify_mode mode)
4332 {
4333 	struct bpf_prog *prog;
4334 	struct bpf_task_work_ctx *ctx;
4335 	int err;
4336 
4337 	BTF_TYPE_EMIT(struct bpf_task_work);
4338 
4339 	prog = bpf_prog_inc_not_zero(aux->prog);
4340 	if (IS_ERR(prog))
4341 		return -EBADF;
4342 	task = bpf_task_acquire(task);
4343 	if (!task) {
4344 		err = -EBADF;
4345 		goto release_prog;
4346 	}
4347 
4348 	ctx = bpf_task_work_acquire_ctx(tw, map);
4349 	if (IS_ERR(ctx)) {
4350 		err = PTR_ERR(ctx);
4351 		goto release_all;
4352 	}
4353 
4354 	ctx->task = task;
4355 	ctx->callback_fn = callback_fn;
4356 	ctx->prog = prog;
4357 	ctx->mode = mode;
4358 	ctx->map = map;
4359 	ctx->map_val = (void *)tw - map->record->task_work_off;
4360 	init_task_work(&ctx->work, bpf_task_work_callback);
4361 	init_irq_work(&ctx->irq_work, bpf_task_work_irq);
4362 
4363 	irq_work_queue(&ctx->irq_work);
4364 	return 0;
4365 
4366 release_all:
4367 	bpf_task_release(task);
4368 release_prog:
4369 	bpf_prog_put(prog);
4370 	return err;
4371 }
4372 
4373 /**
4374  * bpf_task_work_schedule_signal - Schedule BPF callback using task_work_add with TWA_SIGNAL
4375  * mode
4376  * @task: Task struct for which callback should be scheduled
4377  * @tw: Pointer to struct bpf_task_work in BPF map value for internal bookkeeping
4378  * @map__map: bpf_map that embeds struct bpf_task_work in the values
4379  * @callback: pointer to BPF subprogram to call
4380  * @aux: pointer to bpf_prog_aux of the caller BPF program, implicitly set by the verifier
4381  *
4382  * Return: 0 if task work has been scheduled successfully, negative error code otherwise
4383  */
4384 __bpf_kfunc int bpf_task_work_schedule_signal(struct task_struct *task, struct bpf_task_work *tw,
4385 					      void *map__map, bpf_task_work_callback_t callback,
4386 					      struct bpf_prog_aux *aux)
4387 {
4388 	return bpf_task_work_schedule(task, tw, map__map, callback, aux, TWA_SIGNAL);
4389 }
4390 
4391 /**
4392  * bpf_task_work_schedule_resume - Schedule BPF callback using task_work_add with TWA_RESUME
4393  * mode
4394  * @task: Task struct for which callback should be scheduled
4395  * @tw: Pointer to struct bpf_task_work in BPF map value for internal bookkeeping
4396  * @map__map: bpf_map that embeds struct bpf_task_work in the values
4397  * @callback: pointer to BPF subprogram to call
4398  * @aux: pointer to bpf_prog_aux of the caller BPF program, implicitly set by the verifier
4399  *
4400  * Return: 0 if task work has been scheduled successfully, negative error code otherwise
4401  */
4402 __bpf_kfunc int bpf_task_work_schedule_resume(struct task_struct *task, struct bpf_task_work *tw,
4403 					      void *map__map, bpf_task_work_callback_t callback,
4404 					      struct bpf_prog_aux *aux)
4405 {
4406 	return bpf_task_work_schedule(task, tw, map__map, callback, aux, TWA_RESUME);
4407 }
4408 
4409 static int make_file_dynptr(struct file *file, u32 flags, bool may_sleep,
4410 			    struct bpf_dynptr_kern *ptr)
4411 {
4412 	struct bpf_dynptr_file_impl *state;
4413 
4414 	/* flags is currently unsupported */
4415 	if (flags) {
4416 		bpf_dynptr_set_null(ptr);
4417 		return -EINVAL;
4418 	}
4419 
4420 	state = bpf_mem_alloc(&bpf_global_ma, sizeof(struct bpf_dynptr_file_impl));
4421 	if (!state) {
4422 		bpf_dynptr_set_null(ptr);
4423 		return -ENOMEM;
4424 	}
4425 	state->offset = 0;
4426 	state->size = U64_MAX; /* Don't restrict size, as file may change anyways */
4427 	freader_init_from_file(&state->freader, NULL, 0, file, may_sleep);
4428 	bpf_dynptr_init(ptr, state, BPF_DYNPTR_TYPE_FILE, 0, 0);
4429 	bpf_dynptr_set_rdonly(ptr);
4430 	return 0;
4431 }
4432 
4433 __bpf_kfunc int bpf_dynptr_from_file(struct file *file, u32 flags, struct bpf_dynptr *ptr__uninit)
4434 {
4435 	return make_file_dynptr(file, flags, false, (struct bpf_dynptr_kern *)ptr__uninit);
4436 }
4437 
4438 int bpf_dynptr_from_file_sleepable(struct file *file, u32 flags, struct bpf_dynptr *ptr__uninit)
4439 {
4440 	return make_file_dynptr(file, flags, true, (struct bpf_dynptr_kern *)ptr__uninit);
4441 }
4442 
4443 __bpf_kfunc int bpf_dynptr_file_discard(struct bpf_dynptr *dynptr)
4444 {
4445 	struct bpf_dynptr_kern *ptr = (struct bpf_dynptr_kern *)dynptr;
4446 	struct bpf_dynptr_file_impl *df = ptr->data;
4447 
4448 	if (!df)
4449 		return 0;
4450 
4451 	freader_cleanup(&df->freader);
4452 	bpf_mem_free(&bpf_global_ma, df);
4453 	bpf_dynptr_set_null(ptr);
4454 	return 0;
4455 }
4456 
4457 /**
4458  * bpf_timer_cancel_async - try to deactivate a timer
4459  * @timer:	bpf_timer to stop
4460  *
4461  * Returns:
4462  *
4463  *  *  0 when the timer was not active
4464  *  *  1 when the timer was active
4465  *  * -1 when the timer is currently executing the callback function and
4466  *       cannot be stopped
4467  *  * -ECANCELED when the timer will be cancelled asynchronously
4468  *  * -ENOMEM when out of memory
4469  *  * -EINVAL when the timer was not initialized
4470  *  * -ENOENT when this kfunc is racing with timer deletion
4471  */
4472 __bpf_kfunc int bpf_timer_cancel_async(struct bpf_timer *timer)
4473 {
4474 	struct bpf_async_kern *async = (void *)timer;
4475 	struct bpf_async_cb *cb;
4476 	int ret;
4477 
4478 	cb = READ_ONCE(async->cb);
4479 	if (!cb)
4480 		return -EINVAL;
4481 
4482 	/*
4483 	 * Unlike hrtimer_start() it's ok to synchronously call
4484 	 * hrtimer_try_to_cancel() when refcnt reached zero, but deferring to
4485 	 * irq_work is not, since irq callback may execute after RCU GP and
4486 	 * cb could be freed at that time. Check for refcnt zero for
4487 	 * consistency.
4488 	 */
4489 	if (!refcount_inc_not_zero(&cb->refcnt))
4490 		return -ENOENT;
4491 
4492 	if (!defer_timer_wq_op()) {
4493 		struct bpf_hrtimer *t = container_of(cb, struct bpf_hrtimer, cb);
4494 
4495 		ret = hrtimer_try_to_cancel(&t->timer);
4496 		bpf_async_refcount_put(cb);
4497 		return ret;
4498 	} else {
4499 		ret = bpf_async_schedule_op(cb, BPF_ASYNC_CANCEL, 0, 0);
4500 		return ret ? ret : -ECANCELED;
4501 	}
4502 }
4503 
4504 __bpf_kfunc_end_defs();
4505 
4506 static void bpf_task_work_cancel_scheduled(struct irq_work *irq_work)
4507 {
4508 	struct bpf_task_work_ctx *ctx = container_of(irq_work, struct bpf_task_work_ctx, irq_work);
4509 
4510 	bpf_task_work_cancel(ctx); /* this might put task_work callback's ref */
4511 	bpf_task_work_ctx_put(ctx); /* and here we put map's own ref that was transferred to us */
4512 }
4513 
4514 void bpf_task_work_cancel_and_free(void *val)
4515 {
4516 	struct bpf_task_work_kern *twk = val;
4517 	struct bpf_task_work_ctx *ctx;
4518 	enum bpf_task_work_state state;
4519 
4520 	ctx = xchg(&twk->ctx, NULL);
4521 	if (!ctx)
4522 		return;
4523 
4524 	state = xchg(&ctx->state, BPF_TW_FREED);
4525 	if (state == BPF_TW_SCHEDULED) {
4526 		/* run in irq_work to avoid locks in NMI */
4527 		init_irq_work(&ctx->irq_work, bpf_task_work_cancel_scheduled);
4528 		irq_work_queue(&ctx->irq_work);
4529 		return;
4530 	}
4531 
4532 	bpf_task_work_ctx_put(ctx); /* put bpf map's ref */
4533 }
4534 
4535 BTF_KFUNCS_START(generic_btf_ids)
4536 #ifdef CONFIG_CRASH_DUMP
4537 BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
4538 #endif
4539 BTF_ID_FLAGS(func, bpf_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
4540 BTF_ID_FLAGS(func, bpf_percpu_obj_new_impl, KF_ACQUIRE | KF_RET_NULL)
4541 BTF_ID_FLAGS(func, bpf_obj_drop_impl, KF_RELEASE)
4542 BTF_ID_FLAGS(func, bpf_percpu_obj_drop_impl, KF_RELEASE)
4543 BTF_ID_FLAGS(func, bpf_refcount_acquire_impl, KF_ACQUIRE | KF_RET_NULL | KF_RCU)
4544 BTF_ID_FLAGS(func, bpf_list_push_front_impl)
4545 BTF_ID_FLAGS(func, bpf_list_push_back_impl)
4546 BTF_ID_FLAGS(func, bpf_list_pop_front, KF_ACQUIRE | KF_RET_NULL)
4547 BTF_ID_FLAGS(func, bpf_list_pop_back, KF_ACQUIRE | KF_RET_NULL)
4548 BTF_ID_FLAGS(func, bpf_list_front, KF_RET_NULL)
4549 BTF_ID_FLAGS(func, bpf_list_back, KF_RET_NULL)
4550 BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
4551 BTF_ID_FLAGS(func, bpf_task_release, KF_RELEASE)
4552 BTF_ID_FLAGS(func, bpf_rbtree_remove, KF_ACQUIRE | KF_RET_NULL)
4553 BTF_ID_FLAGS(func, bpf_rbtree_add_impl)
4554 BTF_ID_FLAGS(func, bpf_rbtree_first, KF_RET_NULL)
4555 BTF_ID_FLAGS(func, bpf_rbtree_root, KF_RET_NULL)
4556 BTF_ID_FLAGS(func, bpf_rbtree_left, KF_RET_NULL)
4557 BTF_ID_FLAGS(func, bpf_rbtree_right, KF_RET_NULL)
4558 
4559 #ifdef CONFIG_CGROUPS
4560 BTF_ID_FLAGS(func, bpf_cgroup_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
4561 BTF_ID_FLAGS(func, bpf_cgroup_release, KF_RELEASE)
4562 BTF_ID_FLAGS(func, bpf_cgroup_ancestor, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
4563 BTF_ID_FLAGS(func, bpf_cgroup_from_id, KF_ACQUIRE | KF_RET_NULL)
4564 BTF_ID_FLAGS(func, bpf_task_under_cgroup, KF_RCU)
4565 BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
4566 #endif
4567 BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
4568 BTF_ID_FLAGS(func, bpf_task_from_vpid, KF_ACQUIRE | KF_RET_NULL)
4569 BTF_ID_FLAGS(func, bpf_throw)
4570 #ifdef CONFIG_BPF_EVENTS
4571 BTF_ID_FLAGS(func, bpf_send_signal_task)
4572 #endif
4573 #ifdef CONFIG_KEYS
4574 BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
4575 BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
4576 BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
4577 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
4578 BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
4579 #endif
4580 #endif
4581 BTF_KFUNCS_END(generic_btf_ids)
4582 
4583 static const struct btf_kfunc_id_set generic_kfunc_set = {
4584 	.owner = THIS_MODULE,
4585 	.set   = &generic_btf_ids,
4586 };
4587 
4588 
4589 BTF_ID_LIST(generic_dtor_ids)
4590 BTF_ID(struct, task_struct)
4591 BTF_ID(func, bpf_task_release_dtor)
4592 #ifdef CONFIG_CGROUPS
4593 BTF_ID(struct, cgroup)
4594 BTF_ID(func, bpf_cgroup_release_dtor)
4595 #endif
4596 
4597 BTF_KFUNCS_START(common_btf_ids)
4598 BTF_ID_FLAGS(func, bpf_cast_to_kern_ctx, KF_FASTCALL)
4599 BTF_ID_FLAGS(func, bpf_rdonly_cast, KF_FASTCALL)
4600 BTF_ID_FLAGS(func, bpf_rcu_read_lock)
4601 BTF_ID_FLAGS(func, bpf_rcu_read_unlock)
4602 BTF_ID_FLAGS(func, bpf_dynptr_slice, KF_RET_NULL)
4603 BTF_ID_FLAGS(func, bpf_dynptr_slice_rdwr, KF_RET_NULL)
4604 BTF_ID_FLAGS(func, bpf_iter_num_new, KF_ITER_NEW)
4605 BTF_ID_FLAGS(func, bpf_iter_num_next, KF_ITER_NEXT | KF_RET_NULL)
4606 BTF_ID_FLAGS(func, bpf_iter_num_destroy, KF_ITER_DESTROY)
4607 BTF_ID_FLAGS(func, bpf_iter_task_vma_new, KF_ITER_NEW | KF_RCU)
4608 BTF_ID_FLAGS(func, bpf_iter_task_vma_next, KF_ITER_NEXT | KF_RET_NULL)
4609 BTF_ID_FLAGS(func, bpf_iter_task_vma_destroy, KF_ITER_DESTROY)
4610 #ifdef CONFIG_CGROUPS
4611 BTF_ID_FLAGS(func, bpf_iter_css_task_new, KF_ITER_NEW)
4612 BTF_ID_FLAGS(func, bpf_iter_css_task_next, KF_ITER_NEXT | KF_RET_NULL)
4613 BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY)
4614 BTF_ID_FLAGS(func, bpf_iter_css_new, KF_ITER_NEW | KF_RCU_PROTECTED)
4615 BTF_ID_FLAGS(func, bpf_iter_css_next, KF_ITER_NEXT | KF_RET_NULL)
4616 BTF_ID_FLAGS(func, bpf_iter_css_destroy, KF_ITER_DESTROY)
4617 #endif
4618 BTF_ID_FLAGS(func, bpf_iter_task_new, KF_ITER_NEW | KF_RCU_PROTECTED)
4619 BTF_ID_FLAGS(func, bpf_iter_task_next, KF_ITER_NEXT | KF_RET_NULL)
4620 BTF_ID_FLAGS(func, bpf_iter_task_destroy, KF_ITER_DESTROY)
4621 BTF_ID_FLAGS(func, bpf_dynptr_adjust)
4622 BTF_ID_FLAGS(func, bpf_dynptr_is_null)
4623 BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
4624 BTF_ID_FLAGS(func, bpf_dynptr_size)
4625 BTF_ID_FLAGS(func, bpf_dynptr_clone)
4626 BTF_ID_FLAGS(func, bpf_dynptr_copy)
4627 BTF_ID_FLAGS(func, bpf_dynptr_memset)
4628 #ifdef CONFIG_NET
4629 BTF_ID_FLAGS(func, bpf_modify_return_test_tp)
4630 #endif
4631 BTF_ID_FLAGS(func, bpf_wq_init)
4632 BTF_ID_FLAGS(func, bpf_wq_set_callback, KF_IMPLICIT_ARGS)
4633 BTF_ID_FLAGS(func, bpf_wq_start)
4634 BTF_ID_FLAGS(func, bpf_preempt_disable)
4635 BTF_ID_FLAGS(func, bpf_preempt_enable)
4636 BTF_ID_FLAGS(func, bpf_iter_bits_new, KF_ITER_NEW)
4637 BTF_ID_FLAGS(func, bpf_iter_bits_next, KF_ITER_NEXT | KF_RET_NULL)
4638 BTF_ID_FLAGS(func, bpf_iter_bits_destroy, KF_ITER_DESTROY)
4639 BTF_ID_FLAGS(func, bpf_copy_from_user_str, KF_SLEEPABLE)
4640 BTF_ID_FLAGS(func, bpf_copy_from_user_task_str, KF_SLEEPABLE)
4641 BTF_ID_FLAGS(func, bpf_get_kmem_cache)
4642 BTF_ID_FLAGS(func, bpf_iter_kmem_cache_new, KF_ITER_NEW | KF_SLEEPABLE)
4643 BTF_ID_FLAGS(func, bpf_iter_kmem_cache_next, KF_ITER_NEXT | KF_RET_NULL | KF_SLEEPABLE)
4644 BTF_ID_FLAGS(func, bpf_iter_kmem_cache_destroy, KF_ITER_DESTROY | KF_SLEEPABLE)
4645 BTF_ID_FLAGS(func, bpf_local_irq_save)
4646 BTF_ID_FLAGS(func, bpf_local_irq_restore)
4647 #ifdef CONFIG_BPF_EVENTS
4648 BTF_ID_FLAGS(func, bpf_probe_read_user_dynptr)
4649 BTF_ID_FLAGS(func, bpf_probe_read_kernel_dynptr)
4650 BTF_ID_FLAGS(func, bpf_probe_read_user_str_dynptr)
4651 BTF_ID_FLAGS(func, bpf_probe_read_kernel_str_dynptr)
4652 BTF_ID_FLAGS(func, bpf_copy_from_user_dynptr, KF_SLEEPABLE)
4653 BTF_ID_FLAGS(func, bpf_copy_from_user_str_dynptr, KF_SLEEPABLE)
4654 BTF_ID_FLAGS(func, bpf_copy_from_user_task_dynptr, KF_SLEEPABLE)
4655 BTF_ID_FLAGS(func, bpf_copy_from_user_task_str_dynptr, KF_SLEEPABLE)
4656 #endif
4657 #ifdef CONFIG_DMA_SHARED_BUFFER
4658 BTF_ID_FLAGS(func, bpf_iter_dmabuf_new, KF_ITER_NEW | KF_SLEEPABLE)
4659 BTF_ID_FLAGS(func, bpf_iter_dmabuf_next, KF_ITER_NEXT | KF_RET_NULL | KF_SLEEPABLE)
4660 BTF_ID_FLAGS(func, bpf_iter_dmabuf_destroy, KF_ITER_DESTROY | KF_SLEEPABLE)
4661 #endif
4662 BTF_ID_FLAGS(func, __bpf_trap)
4663 BTF_ID_FLAGS(func, bpf_strcmp);
4664 BTF_ID_FLAGS(func, bpf_strcasecmp);
4665 BTF_ID_FLAGS(func, bpf_strncasecmp);
4666 BTF_ID_FLAGS(func, bpf_strchr);
4667 BTF_ID_FLAGS(func, bpf_strchrnul);
4668 BTF_ID_FLAGS(func, bpf_strnchr);
4669 BTF_ID_FLAGS(func, bpf_strrchr);
4670 BTF_ID_FLAGS(func, bpf_strlen);
4671 BTF_ID_FLAGS(func, bpf_strnlen);
4672 BTF_ID_FLAGS(func, bpf_strspn);
4673 BTF_ID_FLAGS(func, bpf_strcspn);
4674 BTF_ID_FLAGS(func, bpf_strstr);
4675 BTF_ID_FLAGS(func, bpf_strcasestr);
4676 BTF_ID_FLAGS(func, bpf_strnstr);
4677 BTF_ID_FLAGS(func, bpf_strncasestr);
4678 #if defined(CONFIG_BPF_LSM) && defined(CONFIG_CGROUPS)
4679 BTF_ID_FLAGS(func, bpf_cgroup_read_xattr, KF_RCU)
4680 #endif
4681 BTF_ID_FLAGS(func, bpf_stream_vprintk, KF_IMPLICIT_ARGS)
4682 BTF_ID_FLAGS(func, bpf_stream_print_stack, KF_IMPLICIT_ARGS)
4683 BTF_ID_FLAGS(func, bpf_task_work_schedule_signal, KF_IMPLICIT_ARGS)
4684 BTF_ID_FLAGS(func, bpf_task_work_schedule_resume, KF_IMPLICIT_ARGS)
4685 BTF_ID_FLAGS(func, bpf_dynptr_from_file)
4686 BTF_ID_FLAGS(func, bpf_dynptr_file_discard)
4687 BTF_ID_FLAGS(func, bpf_timer_cancel_async)
4688 BTF_KFUNCS_END(common_btf_ids)
4689 
4690 static const struct btf_kfunc_id_set common_kfunc_set = {
4691 	.owner = THIS_MODULE,
4692 	.set   = &common_btf_ids,
4693 };
4694 
4695 static int __init kfunc_init(void)
4696 {
4697 	int ret;
4698 	const struct btf_id_dtor_kfunc generic_dtors[] = {
4699 		{
4700 			.btf_id       = generic_dtor_ids[0],
4701 			.kfunc_btf_id = generic_dtor_ids[1]
4702 		},
4703 #ifdef CONFIG_CGROUPS
4704 		{
4705 			.btf_id       = generic_dtor_ids[2],
4706 			.kfunc_btf_id = generic_dtor_ids[3]
4707 		},
4708 #endif
4709 	};
4710 
4711 	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set);
4712 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &generic_kfunc_set);
4713 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &generic_kfunc_set);
4714 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);
4715 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &generic_kfunc_set);
4716 	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SKB, &generic_kfunc_set);
4717 	ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,
4718 						  ARRAY_SIZE(generic_dtors),
4719 						  THIS_MODULE);
4720 	return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &common_kfunc_set);
4721 }
4722 
4723 late_initcall(kfunc_init);
4724 
4725 /* Get a pointer to dynptr data up to len bytes for read only access. If
4726  * the dynptr doesn't have continuous data up to len bytes, return NULL.
4727  */
4728 const void *__bpf_dynptr_data(const struct bpf_dynptr_kern *ptr, u64 len)
4729 {
4730 	const struct bpf_dynptr *p = (struct bpf_dynptr *)ptr;
4731 
4732 	return bpf_dynptr_slice(p, 0, NULL, len);
4733 }
4734 
4735 /* Get a pointer to dynptr data up to len bytes for read write access. If
4736  * the dynptr doesn't have continuous data up to len bytes, or the dynptr
4737  * is read only, return NULL.
4738  */
4739 void *__bpf_dynptr_data_rw(const struct bpf_dynptr_kern *ptr, u64 len)
4740 {
4741 	if (__bpf_dynptr_is_rdonly(ptr))
4742 		return NULL;
4743 	return (void *)__bpf_dynptr_data(ptr, len);
4744 }
4745 
4746 void bpf_map_free_internal_structs(struct bpf_map *map, void *val)
4747 {
4748 	if (btf_record_has_field(map->record, BPF_TIMER))
4749 		bpf_obj_free_timer(map->record, val);
4750 	if (btf_record_has_field(map->record, BPF_WORKQUEUE))
4751 		bpf_obj_free_workqueue(map->record, val);
4752 	if (btf_record_has_field(map->record, BPF_TASK_WORK))
4753 		bpf_obj_free_task_work(map->record, val);
4754 }
4755