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/rcupdate.h>
8 #include <linux/random.h>
9 #include <linux/smp.h>
10 #include <linux/topology.h>
11 #include <linux/ktime.h>
12 #include <linux/sched.h>
13 #include <linux/uidgid.h>
14 #include <linux/filter.h>
15 #include <linux/ctype.h>
16 #include <linux/jiffies.h>
17 #include <linux/pid_namespace.h>
18 #include <linux/proc_ns.h>
19 #include <linux/security.h>
20 #include <linux/btf_ids.h>
21 
22 #include "../../lib/kstrtox.h"
23 
24 /* If kernel subsystem is allowing eBPF programs to call this function,
25  * inside its own verifier_ops->get_func_proto() callback it should return
26  * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
27  *
28  * Different map implementations will rely on rcu in map methods
29  * lookup/update/delete, therefore eBPF programs must run under rcu lock
30  * if program is allowed to access maps, so check rcu_read_lock_held in
31  * all three functions.
32  */
BPF_CALL_2(bpf_map_lookup_elem,struct bpf_map *,map,void *,key)33 BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
34 {
35 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
36 	return (unsigned long) map->ops->map_lookup_elem(map, key);
37 }
38 
39 const struct bpf_func_proto bpf_map_lookup_elem_proto = {
40 	.func		= bpf_map_lookup_elem,
41 	.gpl_only	= false,
42 	.pkt_access	= true,
43 	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
44 	.arg1_type	= ARG_CONST_MAP_PTR,
45 	.arg2_type	= ARG_PTR_TO_MAP_KEY,
46 };
47 
BPF_CALL_4(bpf_map_update_elem,struct bpf_map *,map,void *,key,void *,value,u64,flags)48 BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
49 	   void *, value, u64, flags)
50 {
51 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
52 	return map->ops->map_update_elem(map, key, value, flags);
53 }
54 
55 const struct bpf_func_proto bpf_map_update_elem_proto = {
56 	.func		= bpf_map_update_elem,
57 	.gpl_only	= false,
58 	.pkt_access	= true,
59 	.ret_type	= RET_INTEGER,
60 	.arg1_type	= ARG_CONST_MAP_PTR,
61 	.arg2_type	= ARG_PTR_TO_MAP_KEY,
62 	.arg3_type	= ARG_PTR_TO_MAP_VALUE,
63 	.arg4_type	= ARG_ANYTHING,
64 };
65 
BPF_CALL_2(bpf_map_delete_elem,struct bpf_map *,map,void *,key)66 BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
67 {
68 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
69 	return map->ops->map_delete_elem(map, key);
70 }
71 
72 const struct bpf_func_proto bpf_map_delete_elem_proto = {
73 	.func		= bpf_map_delete_elem,
74 	.gpl_only	= false,
75 	.pkt_access	= true,
76 	.ret_type	= RET_INTEGER,
77 	.arg1_type	= ARG_CONST_MAP_PTR,
78 	.arg2_type	= ARG_PTR_TO_MAP_KEY,
79 };
80 
BPF_CALL_3(bpf_map_push_elem,struct bpf_map *,map,void *,value,u64,flags)81 BPF_CALL_3(bpf_map_push_elem, struct bpf_map *, map, void *, value, u64, flags)
82 {
83 	return map->ops->map_push_elem(map, value, flags);
84 }
85 
86 const struct bpf_func_proto bpf_map_push_elem_proto = {
87 	.func		= bpf_map_push_elem,
88 	.gpl_only	= false,
89 	.pkt_access	= true,
90 	.ret_type	= RET_INTEGER,
91 	.arg1_type	= ARG_CONST_MAP_PTR,
92 	.arg2_type	= ARG_PTR_TO_MAP_VALUE,
93 	.arg3_type	= ARG_ANYTHING,
94 };
95 
BPF_CALL_2(bpf_map_pop_elem,struct bpf_map *,map,void *,value)96 BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value)
97 {
98 	return map->ops->map_pop_elem(map, value);
99 }
100 
101 const struct bpf_func_proto bpf_map_pop_elem_proto = {
102 	.func		= bpf_map_pop_elem,
103 	.gpl_only	= false,
104 	.ret_type	= RET_INTEGER,
105 	.arg1_type	= ARG_CONST_MAP_PTR,
106 	.arg2_type	= ARG_PTR_TO_MAP_VALUE | MEM_UNINIT,
107 };
108 
BPF_CALL_2(bpf_map_peek_elem,struct bpf_map *,map,void *,value)109 BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value)
110 {
111 	return map->ops->map_peek_elem(map, value);
112 }
113 
114 const struct bpf_func_proto bpf_map_peek_elem_proto = {
115 	.func		= bpf_map_peek_elem,
116 	.gpl_only	= false,
117 	.ret_type	= RET_INTEGER,
118 	.arg1_type	= ARG_CONST_MAP_PTR,
119 	.arg2_type	= ARG_PTR_TO_MAP_VALUE | MEM_UNINIT,
120 };
121 
BPF_CALL_3(bpf_map_lookup_percpu_elem,struct bpf_map *,map,void *,key,u32,cpu)122 BPF_CALL_3(bpf_map_lookup_percpu_elem, struct bpf_map *, map, void *, key, u32, cpu)
123 {
124 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
125 	return (unsigned long) map->ops->map_lookup_percpu_elem(map, key, cpu);
126 }
127 
128 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto = {
129 	.func		= bpf_map_lookup_percpu_elem,
130 	.gpl_only	= false,
131 	.pkt_access	= true,
132 	.ret_type	= RET_PTR_TO_MAP_VALUE_OR_NULL,
133 	.arg1_type	= ARG_CONST_MAP_PTR,
134 	.arg2_type	= ARG_PTR_TO_MAP_KEY,
135 	.arg3_type	= ARG_ANYTHING,
136 };
137 
138 const struct bpf_func_proto bpf_get_prandom_u32_proto = {
139 	.func		= bpf_user_rnd_u32,
140 	.gpl_only	= false,
141 	.ret_type	= RET_INTEGER,
142 };
143 
BPF_CALL_0(bpf_get_smp_processor_id)144 BPF_CALL_0(bpf_get_smp_processor_id)
145 {
146 	return smp_processor_id();
147 }
148 
149 const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
150 	.func		= bpf_get_smp_processor_id,
151 	.gpl_only	= false,
152 	.ret_type	= RET_INTEGER,
153 };
154 
BPF_CALL_0(bpf_get_numa_node_id)155 BPF_CALL_0(bpf_get_numa_node_id)
156 {
157 	return numa_node_id();
158 }
159 
160 const struct bpf_func_proto bpf_get_numa_node_id_proto = {
161 	.func		= bpf_get_numa_node_id,
162 	.gpl_only	= false,
163 	.ret_type	= RET_INTEGER,
164 };
165 
BPF_CALL_0(bpf_ktime_get_ns)166 BPF_CALL_0(bpf_ktime_get_ns)
167 {
168 	/* NMI safe access to clock monotonic */
169 	return ktime_get_mono_fast_ns();
170 }
171 
172 const struct bpf_func_proto bpf_ktime_get_ns_proto = {
173 	.func		= bpf_ktime_get_ns,
174 	.gpl_only	= false,
175 	.ret_type	= RET_INTEGER,
176 };
177 
BPF_CALL_0(bpf_ktime_get_boot_ns)178 BPF_CALL_0(bpf_ktime_get_boot_ns)
179 {
180 	/* NMI safe access to clock boottime */
181 	return ktime_get_boot_fast_ns();
182 }
183 
184 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = {
185 	.func		= bpf_ktime_get_boot_ns,
186 	.gpl_only	= false,
187 	.ret_type	= RET_INTEGER,
188 };
189 
BPF_CALL_0(bpf_ktime_get_coarse_ns)190 BPF_CALL_0(bpf_ktime_get_coarse_ns)
191 {
192 	return ktime_get_coarse_ns();
193 }
194 
195 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto = {
196 	.func		= bpf_ktime_get_coarse_ns,
197 	.gpl_only	= false,
198 	.ret_type	= RET_INTEGER,
199 };
200 
BPF_CALL_0(bpf_get_current_pid_tgid)201 BPF_CALL_0(bpf_get_current_pid_tgid)
202 {
203 	struct task_struct *task = current;
204 
205 	if (unlikely(!task))
206 		return -EINVAL;
207 
208 	return (u64) task->tgid << 32 | task->pid;
209 }
210 
211 const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
212 	.func		= bpf_get_current_pid_tgid,
213 	.gpl_only	= false,
214 	.ret_type	= RET_INTEGER,
215 };
216 
BPF_CALL_0(bpf_get_current_uid_gid)217 BPF_CALL_0(bpf_get_current_uid_gid)
218 {
219 	struct task_struct *task = current;
220 	kuid_t uid;
221 	kgid_t gid;
222 
223 	if (unlikely(!task))
224 		return -EINVAL;
225 
226 	current_uid_gid(&uid, &gid);
227 	return (u64) from_kgid(&init_user_ns, gid) << 32 |
228 		     from_kuid(&init_user_ns, uid);
229 }
230 
231 const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
232 	.func		= bpf_get_current_uid_gid,
233 	.gpl_only	= false,
234 	.ret_type	= RET_INTEGER,
235 };
236 
BPF_CALL_2(bpf_get_current_comm,char *,buf,u32,size)237 BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size)
238 {
239 	struct task_struct *task = current;
240 
241 	if (unlikely(!task))
242 		goto err_clear;
243 
244 	/* Verifier guarantees that size > 0 */
245 	strscpy(buf, task->comm, size);
246 	return 0;
247 err_clear:
248 	memset(buf, 0, size);
249 	return -EINVAL;
250 }
251 
252 const struct bpf_func_proto bpf_get_current_comm_proto = {
253 	.func		= bpf_get_current_comm,
254 	.gpl_only	= false,
255 	.ret_type	= RET_INTEGER,
256 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
257 	.arg2_type	= ARG_CONST_SIZE,
258 };
259 
260 #if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK)
261 
__bpf_spin_lock(struct bpf_spin_lock * lock)262 static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
263 {
264 	arch_spinlock_t *l = (void *)lock;
265 	union {
266 		__u32 val;
267 		arch_spinlock_t lock;
268 	} u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED };
269 
270 	compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0");
271 	BUILD_BUG_ON(sizeof(*l) != sizeof(__u32));
272 	BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32));
273 	arch_spin_lock(l);
274 }
275 
__bpf_spin_unlock(struct bpf_spin_lock * lock)276 static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
277 {
278 	arch_spinlock_t *l = (void *)lock;
279 
280 	arch_spin_unlock(l);
281 }
282 
283 #else
284 
__bpf_spin_lock(struct bpf_spin_lock * lock)285 static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
286 {
287 	atomic_t *l = (void *)lock;
288 
289 	BUILD_BUG_ON(sizeof(*l) != sizeof(*lock));
290 	do {
291 		atomic_cond_read_relaxed(l, !VAL);
292 	} while (atomic_xchg(l, 1));
293 }
294 
__bpf_spin_unlock(struct bpf_spin_lock * lock)295 static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
296 {
297 	atomic_t *l = (void *)lock;
298 
299 	atomic_set_release(l, 0);
300 }
301 
302 #endif
303 
304 static DEFINE_PER_CPU(unsigned long, irqsave_flags);
305 
__bpf_spin_lock_irqsave(struct bpf_spin_lock * lock)306 static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock)
307 {
308 	unsigned long flags;
309 
310 	local_irq_save(flags);
311 	__bpf_spin_lock(lock);
312 	__this_cpu_write(irqsave_flags, flags);
313 }
314 
BPF_CALL_1(bpf_spin_lock,struct bpf_spin_lock *,lock)315 notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
316 {
317 	__bpf_spin_lock_irqsave(lock);
318 	return 0;
319 }
320 
321 const struct bpf_func_proto bpf_spin_lock_proto = {
322 	.func		= bpf_spin_lock,
323 	.gpl_only	= false,
324 	.ret_type	= RET_VOID,
325 	.arg1_type	= ARG_PTR_TO_SPIN_LOCK,
326 };
327 
__bpf_spin_unlock_irqrestore(struct bpf_spin_lock * lock)328 static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock)
329 {
330 	unsigned long flags;
331 
332 	flags = __this_cpu_read(irqsave_flags);
333 	__bpf_spin_unlock(lock);
334 	local_irq_restore(flags);
335 }
336 
BPF_CALL_1(bpf_spin_unlock,struct bpf_spin_lock *,lock)337 notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
338 {
339 	__bpf_spin_unlock_irqrestore(lock);
340 	return 0;
341 }
342 
343 const struct bpf_func_proto bpf_spin_unlock_proto = {
344 	.func		= bpf_spin_unlock,
345 	.gpl_only	= false,
346 	.ret_type	= RET_VOID,
347 	.arg1_type	= ARG_PTR_TO_SPIN_LOCK,
348 };
349 
copy_map_value_locked(struct bpf_map * map,void * dst,void * src,bool lock_src)350 void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
351 			   bool lock_src)
352 {
353 	struct bpf_spin_lock *lock;
354 
355 	if (lock_src)
356 		lock = src + map->spin_lock_off;
357 	else
358 		lock = dst + map->spin_lock_off;
359 	preempt_disable();
360 	__bpf_spin_lock_irqsave(lock);
361 	copy_map_value(map, dst, src);
362 	__bpf_spin_unlock_irqrestore(lock);
363 	preempt_enable();
364 }
365 
BPF_CALL_0(bpf_jiffies64)366 BPF_CALL_0(bpf_jiffies64)
367 {
368 	return get_jiffies_64();
369 }
370 
371 const struct bpf_func_proto bpf_jiffies64_proto = {
372 	.func		= bpf_jiffies64,
373 	.gpl_only	= false,
374 	.ret_type	= RET_INTEGER,
375 };
376 
377 #ifdef CONFIG_CGROUPS
BPF_CALL_0(bpf_get_current_cgroup_id)378 BPF_CALL_0(bpf_get_current_cgroup_id)
379 {
380 	struct cgroup *cgrp;
381 	u64 cgrp_id;
382 
383 	rcu_read_lock();
384 	cgrp = task_dfl_cgroup(current);
385 	cgrp_id = cgroup_id(cgrp);
386 	rcu_read_unlock();
387 
388 	return cgrp_id;
389 }
390 
391 const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
392 	.func		= bpf_get_current_cgroup_id,
393 	.gpl_only	= false,
394 	.ret_type	= RET_INTEGER,
395 };
396 
BPF_CALL_1(bpf_get_current_ancestor_cgroup_id,int,ancestor_level)397 BPF_CALL_1(bpf_get_current_ancestor_cgroup_id, int, ancestor_level)
398 {
399 	struct cgroup *cgrp;
400 	struct cgroup *ancestor;
401 	u64 cgrp_id;
402 
403 	rcu_read_lock();
404 	cgrp = task_dfl_cgroup(current);
405 	ancestor = cgroup_ancestor(cgrp, ancestor_level);
406 	cgrp_id = ancestor ? cgroup_id(ancestor) : 0;
407 	rcu_read_unlock();
408 
409 	return cgrp_id;
410 }
411 
412 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {
413 	.func		= bpf_get_current_ancestor_cgroup_id,
414 	.gpl_only	= false,
415 	.ret_type	= RET_INTEGER,
416 	.arg1_type	= ARG_ANYTHING,
417 };
418 
419 #ifdef CONFIG_CGROUP_BPF
420 
BPF_CALL_2(bpf_get_local_storage,struct bpf_map *,map,u64,flags)421 BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
422 {
423 	/* flags argument is not used now,
424 	 * but provides an ability to extend the API.
425 	 * verifier checks that its value is correct.
426 	 */
427 	enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
428 	struct bpf_cgroup_storage *storage;
429 	struct bpf_cg_run_ctx *ctx;
430 	void *ptr;
431 
432 	/* get current cgroup storage from BPF run context */
433 	ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
434 	storage = ctx->prog_item->cgroup_storage[stype];
435 
436 	if (stype == BPF_CGROUP_STORAGE_SHARED)
437 		ptr = &READ_ONCE(storage->buf)->data[0];
438 	else
439 		ptr = this_cpu_ptr(storage->percpu_buf);
440 
441 	return (unsigned long)ptr;
442 }
443 
444 const struct bpf_func_proto bpf_get_local_storage_proto = {
445 	.func		= bpf_get_local_storage,
446 	.gpl_only	= false,
447 	.ret_type	= RET_PTR_TO_MAP_VALUE,
448 	.arg1_type	= ARG_CONST_MAP_PTR,
449 	.arg2_type	= ARG_ANYTHING,
450 };
451 #endif
452 
453 #define BPF_STRTOX_BASE_MASK 0x1F
454 
__bpf_strtoull(const char * buf,size_t buf_len,u64 flags,unsigned long long * res,bool * is_negative)455 static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
456 			  unsigned long long *res, bool *is_negative)
457 {
458 	unsigned int base = flags & BPF_STRTOX_BASE_MASK;
459 	const char *cur_buf = buf;
460 	size_t cur_len = buf_len;
461 	unsigned int consumed;
462 	size_t val_len;
463 	char str[64];
464 
465 	if (!buf || !buf_len || !res || !is_negative)
466 		return -EINVAL;
467 
468 	if (base != 0 && base != 8 && base != 10 && base != 16)
469 		return -EINVAL;
470 
471 	if (flags & ~BPF_STRTOX_BASE_MASK)
472 		return -EINVAL;
473 
474 	while (cur_buf < buf + buf_len && isspace(*cur_buf))
475 		++cur_buf;
476 
477 	*is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
478 	if (*is_negative)
479 		++cur_buf;
480 
481 	consumed = cur_buf - buf;
482 	cur_len -= consumed;
483 	if (!cur_len)
484 		return -EINVAL;
485 
486 	cur_len = min(cur_len, sizeof(str) - 1);
487 	memcpy(str, cur_buf, cur_len);
488 	str[cur_len] = '\0';
489 	cur_buf = str;
490 
491 	cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
492 	val_len = _parse_integer(cur_buf, base, res);
493 
494 	if (val_len & KSTRTOX_OVERFLOW)
495 		return -ERANGE;
496 
497 	if (val_len == 0)
498 		return -EINVAL;
499 
500 	cur_buf += val_len;
501 	consumed += cur_buf - str;
502 
503 	return consumed;
504 }
505 
__bpf_strtoll(const char * buf,size_t buf_len,u64 flags,long long * res)506 static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
507 			 long long *res)
508 {
509 	unsigned long long _res;
510 	bool is_negative;
511 	int err;
512 
513 	err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
514 	if (err < 0)
515 		return err;
516 	if (is_negative) {
517 		if ((long long)-_res > 0)
518 			return -ERANGE;
519 		*res = -_res;
520 	} else {
521 		if ((long long)_res < 0)
522 			return -ERANGE;
523 		*res = _res;
524 	}
525 	return err;
526 }
527 
BPF_CALL_4(bpf_strtol,const char *,buf,size_t,buf_len,u64,flags,long *,res)528 BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
529 	   long *, res)
530 {
531 	long long _res;
532 	int err;
533 
534 	err = __bpf_strtoll(buf, buf_len, flags, &_res);
535 	if (err < 0)
536 		return err;
537 	if (_res != (long)_res)
538 		return -ERANGE;
539 	*res = _res;
540 	return err;
541 }
542 
543 const struct bpf_func_proto bpf_strtol_proto = {
544 	.func		= bpf_strtol,
545 	.gpl_only	= false,
546 	.ret_type	= RET_INTEGER,
547 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
548 	.arg2_type	= ARG_CONST_SIZE,
549 	.arg3_type	= ARG_ANYTHING,
550 	.arg4_type	= ARG_PTR_TO_LONG,
551 };
552 
BPF_CALL_4(bpf_strtoul,const char *,buf,size_t,buf_len,u64,flags,unsigned long *,res)553 BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
554 	   unsigned long *, res)
555 {
556 	unsigned long long _res;
557 	bool is_negative;
558 	int err;
559 
560 	err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
561 	if (err < 0)
562 		return err;
563 	if (is_negative)
564 		return -EINVAL;
565 	if (_res != (unsigned long)_res)
566 		return -ERANGE;
567 	*res = _res;
568 	return err;
569 }
570 
571 const struct bpf_func_proto bpf_strtoul_proto = {
572 	.func		= bpf_strtoul,
573 	.gpl_only	= false,
574 	.ret_type	= RET_INTEGER,
575 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
576 	.arg2_type	= ARG_CONST_SIZE,
577 	.arg3_type	= ARG_ANYTHING,
578 	.arg4_type	= ARG_PTR_TO_LONG,
579 };
580 #endif
581 
BPF_CALL_3(bpf_strncmp,const char *,s1,u32,s1_sz,const char *,s2)582 BPF_CALL_3(bpf_strncmp, const char *, s1, u32, s1_sz, const char *, s2)
583 {
584 	return strncmp(s1, s2, s1_sz);
585 }
586 
587 const struct bpf_func_proto bpf_strncmp_proto = {
588 	.func		= bpf_strncmp,
589 	.gpl_only	= false,
590 	.ret_type	= RET_INTEGER,
591 	.arg1_type	= ARG_PTR_TO_MEM,
592 	.arg2_type	= ARG_CONST_SIZE,
593 	.arg3_type	= ARG_PTR_TO_CONST_STR,
594 };
595 
BPF_CALL_4(bpf_get_ns_current_pid_tgid,u64,dev,u64,ino,struct bpf_pidns_info *,nsdata,u32,size)596 BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
597 	   struct bpf_pidns_info *, nsdata, u32, size)
598 {
599 	struct task_struct *task = current;
600 	struct pid_namespace *pidns;
601 	int err = -EINVAL;
602 
603 	if (unlikely(size != sizeof(struct bpf_pidns_info)))
604 		goto clear;
605 
606 	if (unlikely((u64)(dev_t)dev != dev))
607 		goto clear;
608 
609 	if (unlikely(!task))
610 		goto clear;
611 
612 	pidns = task_active_pid_ns(task);
613 	if (unlikely(!pidns)) {
614 		err = -ENOENT;
615 		goto clear;
616 	}
617 
618 	if (!ns_match(&pidns->ns, (dev_t)dev, ino))
619 		goto clear;
620 
621 	nsdata->pid = task_pid_nr_ns(task, pidns);
622 	nsdata->tgid = task_tgid_nr_ns(task, pidns);
623 	return 0;
624 clear:
625 	memset((void *)nsdata, 0, (size_t) size);
626 	return err;
627 }
628 
629 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
630 	.func		= bpf_get_ns_current_pid_tgid,
631 	.gpl_only	= false,
632 	.ret_type	= RET_INTEGER,
633 	.arg1_type	= ARG_ANYTHING,
634 	.arg2_type	= ARG_ANYTHING,
635 	.arg3_type      = ARG_PTR_TO_UNINIT_MEM,
636 	.arg4_type      = ARG_CONST_SIZE,
637 };
638 
639 static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
640 	.func		= bpf_get_raw_cpu_id,
641 	.gpl_only	= false,
642 	.ret_type	= RET_INTEGER,
643 };
644 
BPF_CALL_5(bpf_event_output_data,void *,ctx,struct bpf_map *,map,u64,flags,void *,data,u64,size)645 BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map,
646 	   u64, flags, void *, data, u64, size)
647 {
648 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
649 		return -EINVAL;
650 
651 	return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
652 }
653 
654 const struct bpf_func_proto bpf_event_output_data_proto =  {
655 	.func		= bpf_event_output_data,
656 	.gpl_only       = true,
657 	.ret_type       = RET_INTEGER,
658 	.arg1_type      = ARG_PTR_TO_CTX,
659 	.arg2_type      = ARG_CONST_MAP_PTR,
660 	.arg3_type      = ARG_ANYTHING,
661 	.arg4_type      = ARG_PTR_TO_MEM | MEM_RDONLY,
662 	.arg5_type      = ARG_CONST_SIZE_OR_ZERO,
663 };
664 
BPF_CALL_3(bpf_copy_from_user,void *,dst,u32,size,const void __user *,user_ptr)665 BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size,
666 	   const void __user *, user_ptr)
667 {
668 	int ret = copy_from_user(dst, user_ptr, size);
669 
670 	if (unlikely(ret)) {
671 		memset(dst, 0, size);
672 		ret = -EFAULT;
673 	}
674 
675 	return ret;
676 }
677 
678 const struct bpf_func_proto bpf_copy_from_user_proto = {
679 	.func		= bpf_copy_from_user,
680 	.gpl_only	= false,
681 	.ret_type	= RET_INTEGER,
682 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
683 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
684 	.arg3_type	= ARG_ANYTHING,
685 };
686 
BPF_CALL_5(bpf_copy_from_user_task,void *,dst,u32,size,const void __user *,user_ptr,struct task_struct *,tsk,u64,flags)687 BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size,
688 	   const void __user *, user_ptr, struct task_struct *, tsk, u64, flags)
689 {
690 	int ret;
691 
692 	/* flags is not used yet */
693 	if (unlikely(flags))
694 		return -EINVAL;
695 
696 	if (unlikely(!size))
697 		return 0;
698 
699 	ret = access_process_vm(tsk, (unsigned long)user_ptr, dst, size, 0);
700 	if (ret == size)
701 		return 0;
702 
703 	memset(dst, 0, size);
704 	/* Return -EFAULT for partial read */
705 	return ret < 0 ? ret : -EFAULT;
706 }
707 
708 const struct bpf_func_proto bpf_copy_from_user_task_proto = {
709 	.func		= bpf_copy_from_user_task,
710 	.gpl_only	= true,
711 	.ret_type	= RET_INTEGER,
712 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
713 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
714 	.arg3_type	= ARG_ANYTHING,
715 	.arg4_type	= ARG_PTR_TO_BTF_ID,
716 	.arg4_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
717 	.arg5_type	= ARG_ANYTHING
718 };
719 
BPF_CALL_2(bpf_per_cpu_ptr,const void *,ptr,u32,cpu)720 BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu)
721 {
722 	if (cpu >= nr_cpu_ids)
723 		return (unsigned long)NULL;
724 
725 	return (unsigned long)per_cpu_ptr((const void __percpu *)ptr, cpu);
726 }
727 
728 const struct bpf_func_proto bpf_per_cpu_ptr_proto = {
729 	.func		= bpf_per_cpu_ptr,
730 	.gpl_only	= false,
731 	.ret_type	= RET_PTR_TO_MEM_OR_BTF_ID | PTR_MAYBE_NULL | MEM_RDONLY,
732 	.arg1_type	= ARG_PTR_TO_PERCPU_BTF_ID,
733 	.arg2_type	= ARG_ANYTHING,
734 };
735 
BPF_CALL_1(bpf_this_cpu_ptr,const void *,percpu_ptr)736 BPF_CALL_1(bpf_this_cpu_ptr, const void *, percpu_ptr)
737 {
738 	return (unsigned long)this_cpu_ptr((const void __percpu *)percpu_ptr);
739 }
740 
741 const struct bpf_func_proto bpf_this_cpu_ptr_proto = {
742 	.func		= bpf_this_cpu_ptr,
743 	.gpl_only	= false,
744 	.ret_type	= RET_PTR_TO_MEM_OR_BTF_ID | MEM_RDONLY,
745 	.arg1_type	= ARG_PTR_TO_PERCPU_BTF_ID,
746 };
747 
bpf_trace_copy_string(char * buf,void * unsafe_ptr,char fmt_ptype,size_t bufsz)748 static int bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
749 		size_t bufsz)
750 {
751 	void __user *user_ptr = (__force void __user *)unsafe_ptr;
752 
753 	buf[0] = 0;
754 
755 	switch (fmt_ptype) {
756 	case 's':
757 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
758 		if ((unsigned long)unsafe_ptr < TASK_SIZE)
759 			return strncpy_from_user_nofault(buf, user_ptr, bufsz);
760 		fallthrough;
761 #endif
762 	case 'k':
763 		return strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
764 	case 'u':
765 		return strncpy_from_user_nofault(buf, user_ptr, bufsz);
766 	}
767 
768 	return -EINVAL;
769 }
770 
771 /* Per-cpu temp buffers used by printf-like helpers to store the bprintf binary
772  * arguments representation.
773  */
774 #define MAX_BPRINTF_BUF_LEN	512
775 
776 /* Support executing three nested bprintf helper calls on a given CPU */
777 #define MAX_BPRINTF_NEST_LEVEL	3
778 struct bpf_bprintf_buffers {
779 	char tmp_bufs[MAX_BPRINTF_NEST_LEVEL][MAX_BPRINTF_BUF_LEN];
780 };
781 static DEFINE_PER_CPU(struct bpf_bprintf_buffers, bpf_bprintf_bufs);
782 static DEFINE_PER_CPU(int, bpf_bprintf_nest_level);
783 
try_get_fmt_tmp_buf(char ** tmp_buf)784 static int try_get_fmt_tmp_buf(char **tmp_buf)
785 {
786 	struct bpf_bprintf_buffers *bufs;
787 	int nest_level;
788 
789 	preempt_disable();
790 	nest_level = this_cpu_inc_return(bpf_bprintf_nest_level);
791 	if (WARN_ON_ONCE(nest_level > MAX_BPRINTF_NEST_LEVEL)) {
792 		this_cpu_dec(bpf_bprintf_nest_level);
793 		preempt_enable();
794 		return -EBUSY;
795 	}
796 	bufs = this_cpu_ptr(&bpf_bprintf_bufs);
797 	*tmp_buf = bufs->tmp_bufs[nest_level - 1];
798 
799 	return 0;
800 }
801 
bpf_bprintf_cleanup(void)802 void bpf_bprintf_cleanup(void)
803 {
804 	if (this_cpu_read(bpf_bprintf_nest_level)) {
805 		this_cpu_dec(bpf_bprintf_nest_level);
806 		preempt_enable();
807 	}
808 }
809 
810 /*
811  * bpf_bprintf_prepare - Generic pass on format strings for bprintf-like helpers
812  *
813  * Returns a negative value if fmt is an invalid format string or 0 otherwise.
814  *
815  * This can be used in two ways:
816  * - Format string verification only: when bin_args is NULL
817  * - Arguments preparation: in addition to the above verification, it writes in
818  *   bin_args a binary representation of arguments usable by bstr_printf where
819  *   pointers from BPF have been sanitized.
820  *
821  * In argument preparation mode, if 0 is returned, safe temporary buffers are
822  * allocated and bpf_bprintf_cleanup should be called to free them after use.
823  */
bpf_bprintf_prepare(char * fmt,u32 fmt_size,const u64 * raw_args,u32 ** bin_args,u32 num_args)824 int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args,
825 			u32 **bin_args, u32 num_args)
826 {
827 	char *unsafe_ptr = NULL, *tmp_buf = NULL, *tmp_buf_end, *fmt_end;
828 	size_t sizeof_cur_arg, sizeof_cur_ip;
829 	int err, i, num_spec = 0;
830 	u64 cur_arg;
831 	char fmt_ptype, cur_ip[16], ip_spec[] = "%pXX";
832 
833 	fmt_end = strnchr(fmt, fmt_size, 0);
834 	if (!fmt_end)
835 		return -EINVAL;
836 	fmt_size = fmt_end - fmt;
837 
838 	if (bin_args) {
839 		if (num_args && try_get_fmt_tmp_buf(&tmp_buf))
840 			return -EBUSY;
841 
842 		tmp_buf_end = tmp_buf + MAX_BPRINTF_BUF_LEN;
843 		*bin_args = (u32 *)tmp_buf;
844 	}
845 
846 	for (i = 0; i < fmt_size; i++) {
847 		if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
848 			err = -EINVAL;
849 			goto out;
850 		}
851 
852 		if (fmt[i] != '%')
853 			continue;
854 
855 		if (fmt[i + 1] == '%') {
856 			i++;
857 			continue;
858 		}
859 
860 		if (num_spec >= num_args) {
861 			err = -EINVAL;
862 			goto out;
863 		}
864 
865 		/* The string is zero-terminated so if fmt[i] != 0, we can
866 		 * always access fmt[i + 1], in the worst case it will be a 0
867 		 */
868 		i++;
869 
870 		/* skip optional "[0 +-][num]" width formatting field */
871 		while (fmt[i] == '0' || fmt[i] == '+'  || fmt[i] == '-' ||
872 		       fmt[i] == ' ')
873 			i++;
874 		if (fmt[i] >= '1' && fmt[i] <= '9') {
875 			i++;
876 			while (fmt[i] >= '0' && fmt[i] <= '9')
877 				i++;
878 		}
879 
880 		if (fmt[i] == 'p') {
881 			sizeof_cur_arg = sizeof(long);
882 
883 			if ((fmt[i + 1] == 'k' || fmt[i + 1] == 'u') &&
884 			    fmt[i + 2] == 's') {
885 				fmt_ptype = fmt[i + 1];
886 				i += 2;
887 				goto fmt_str;
888 			}
889 
890 			if (fmt[i + 1] == 0 || isspace(fmt[i + 1]) ||
891 			    ispunct(fmt[i + 1]) || fmt[i + 1] == 'K' ||
892 			    fmt[i + 1] == 'x' || fmt[i + 1] == 's' ||
893 			    fmt[i + 1] == 'S') {
894 				/* just kernel pointers */
895 				if (tmp_buf)
896 					cur_arg = raw_args[num_spec];
897 				i++;
898 				goto nocopy_fmt;
899 			}
900 
901 			if (fmt[i + 1] == 'B') {
902 				if (tmp_buf)  {
903 					err = snprintf(tmp_buf,
904 						       (tmp_buf_end - tmp_buf),
905 						       "%pB",
906 						       (void *)(long)raw_args[num_spec]);
907 					tmp_buf += (err + 1);
908 				}
909 
910 				i++;
911 				num_spec++;
912 				continue;
913 			}
914 
915 			/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
916 			if ((fmt[i + 1] != 'i' && fmt[i + 1] != 'I') ||
917 			    (fmt[i + 2] != '4' && fmt[i + 2] != '6')) {
918 				err = -EINVAL;
919 				goto out;
920 			}
921 
922 			i += 2;
923 			if (!tmp_buf)
924 				goto nocopy_fmt;
925 
926 			sizeof_cur_ip = (fmt[i] == '4') ? 4 : 16;
927 			if (tmp_buf_end - tmp_buf < sizeof_cur_ip) {
928 				err = -ENOSPC;
929 				goto out;
930 			}
931 
932 			unsafe_ptr = (char *)(long)raw_args[num_spec];
933 			err = copy_from_kernel_nofault(cur_ip, unsafe_ptr,
934 						       sizeof_cur_ip);
935 			if (err < 0)
936 				memset(cur_ip, 0, sizeof_cur_ip);
937 
938 			/* hack: bstr_printf expects IP addresses to be
939 			 * pre-formatted as strings, ironically, the easiest way
940 			 * to do that is to call snprintf.
941 			 */
942 			ip_spec[2] = fmt[i - 1];
943 			ip_spec[3] = fmt[i];
944 			err = snprintf(tmp_buf, tmp_buf_end - tmp_buf,
945 				       ip_spec, &cur_ip);
946 
947 			tmp_buf += err + 1;
948 			num_spec++;
949 
950 			continue;
951 		} else if (fmt[i] == 's') {
952 			fmt_ptype = fmt[i];
953 fmt_str:
954 			if (fmt[i + 1] != 0 &&
955 			    !isspace(fmt[i + 1]) &&
956 			    !ispunct(fmt[i + 1])) {
957 				err = -EINVAL;
958 				goto out;
959 			}
960 
961 			if (!tmp_buf)
962 				goto nocopy_fmt;
963 
964 			if (tmp_buf_end == tmp_buf) {
965 				err = -ENOSPC;
966 				goto out;
967 			}
968 
969 			unsafe_ptr = (char *)(long)raw_args[num_spec];
970 			err = bpf_trace_copy_string(tmp_buf, unsafe_ptr,
971 						    fmt_ptype,
972 						    tmp_buf_end - tmp_buf);
973 			if (err < 0) {
974 				tmp_buf[0] = '\0';
975 				err = 1;
976 			}
977 
978 			tmp_buf += err;
979 			num_spec++;
980 
981 			continue;
982 		} else if (fmt[i] == 'c') {
983 			if (!tmp_buf)
984 				goto nocopy_fmt;
985 
986 			if (tmp_buf_end == tmp_buf) {
987 				err = -ENOSPC;
988 				goto out;
989 			}
990 
991 			*tmp_buf = raw_args[num_spec];
992 			tmp_buf++;
993 			num_spec++;
994 
995 			continue;
996 		}
997 
998 		sizeof_cur_arg = sizeof(int);
999 
1000 		if (fmt[i] == 'l') {
1001 			sizeof_cur_arg = sizeof(long);
1002 			i++;
1003 		}
1004 		if (fmt[i] == 'l') {
1005 			sizeof_cur_arg = sizeof(long long);
1006 			i++;
1007 		}
1008 
1009 		if (fmt[i] != 'i' && fmt[i] != 'd' && fmt[i] != 'u' &&
1010 		    fmt[i] != 'x' && fmt[i] != 'X') {
1011 			err = -EINVAL;
1012 			goto out;
1013 		}
1014 
1015 		if (tmp_buf)
1016 			cur_arg = raw_args[num_spec];
1017 nocopy_fmt:
1018 		if (tmp_buf) {
1019 			tmp_buf = PTR_ALIGN(tmp_buf, sizeof(u32));
1020 			if (tmp_buf_end - tmp_buf < sizeof_cur_arg) {
1021 				err = -ENOSPC;
1022 				goto out;
1023 			}
1024 
1025 			if (sizeof_cur_arg == 8) {
1026 				*(u32 *)tmp_buf = *(u32 *)&cur_arg;
1027 				*(u32 *)(tmp_buf + 4) = *((u32 *)&cur_arg + 1);
1028 			} else {
1029 				*(u32 *)tmp_buf = (u32)(long)cur_arg;
1030 			}
1031 			tmp_buf += sizeof_cur_arg;
1032 		}
1033 		num_spec++;
1034 	}
1035 
1036 	err = 0;
1037 out:
1038 	if (err)
1039 		bpf_bprintf_cleanup();
1040 	return err;
1041 }
1042 
BPF_CALL_5(bpf_snprintf,char *,str,u32,str_size,char *,fmt,const void *,data,u32,data_len)1043 BPF_CALL_5(bpf_snprintf, char *, str, u32, str_size, char *, fmt,
1044 	   const void *, data, u32, data_len)
1045 {
1046 	int err, num_args;
1047 	u32 *bin_args;
1048 
1049 	if (data_len % 8 || data_len > MAX_BPRINTF_VARARGS * 8 ||
1050 	    (data_len && !data))
1051 		return -EINVAL;
1052 	num_args = data_len / 8;
1053 
1054 	/* ARG_PTR_TO_CONST_STR guarantees that fmt is zero-terminated so we
1055 	 * can safely give an unbounded size.
1056 	 */
1057 	err = bpf_bprintf_prepare(fmt, UINT_MAX, data, &bin_args, num_args);
1058 	if (err < 0)
1059 		return err;
1060 
1061 	err = bstr_printf(str, str_size, fmt, bin_args);
1062 
1063 	bpf_bprintf_cleanup();
1064 
1065 	return err + 1;
1066 }
1067 
1068 const struct bpf_func_proto bpf_snprintf_proto = {
1069 	.func		= bpf_snprintf,
1070 	.gpl_only	= true,
1071 	.ret_type	= RET_INTEGER,
1072 	.arg1_type	= ARG_PTR_TO_MEM_OR_NULL,
1073 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1074 	.arg3_type	= ARG_PTR_TO_CONST_STR,
1075 	.arg4_type	= ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
1076 	.arg5_type	= ARG_CONST_SIZE_OR_ZERO,
1077 };
1078 
1079 /* BPF map elements can contain 'struct bpf_timer'.
1080  * Such map owns all of its BPF timers.
1081  * 'struct bpf_timer' is allocated as part of map element allocation
1082  * and it's zero initialized.
1083  * That space is used to keep 'struct bpf_timer_kern'.
1084  * bpf_timer_init() allocates 'struct bpf_hrtimer', inits hrtimer, and
1085  * remembers 'struct bpf_map *' pointer it's part of.
1086  * bpf_timer_set_callback() increments prog refcnt and assign bpf callback_fn.
1087  * bpf_timer_start() arms the timer.
1088  * If user space reference to a map goes to zero at this point
1089  * ops->map_release_uref callback is responsible for cancelling the timers,
1090  * freeing their memory, and decrementing prog's refcnts.
1091  * bpf_timer_cancel() cancels the timer and decrements prog's refcnt.
1092  * Inner maps can contain bpf timers as well. ops->map_release_uref is
1093  * freeing the timers when inner map is replaced or deleted by user space.
1094  */
1095 struct bpf_hrtimer {
1096 	struct hrtimer timer;
1097 	struct bpf_map *map;
1098 	struct bpf_prog *prog;
1099 	void __rcu *callback_fn;
1100 	void *value;
1101 };
1102 
1103 /* the actual struct hidden inside uapi struct bpf_timer */
1104 struct bpf_timer_kern {
1105 	struct bpf_hrtimer *timer;
1106 	/* bpf_spin_lock is used here instead of spinlock_t to make
1107 	 * sure that it always fits into space reserved by struct bpf_timer
1108 	 * regardless of LOCKDEP and spinlock debug flags.
1109 	 */
1110 	struct bpf_spin_lock lock;
1111 } __attribute__((aligned(8)));
1112 
1113 static DEFINE_PER_CPU(struct bpf_hrtimer *, hrtimer_running);
1114 
bpf_timer_cb(struct hrtimer * hrtimer)1115 static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer)
1116 {
1117 	struct bpf_hrtimer *t = container_of(hrtimer, struct bpf_hrtimer, timer);
1118 	struct bpf_map *map = t->map;
1119 	void *value = t->value;
1120 	bpf_callback_t callback_fn;
1121 	void *key;
1122 	u32 idx;
1123 
1124 	BTF_TYPE_EMIT(struct bpf_timer);
1125 	callback_fn = rcu_dereference_check(t->callback_fn, rcu_read_lock_bh_held());
1126 	if (!callback_fn)
1127 		goto out;
1128 
1129 	/* bpf_timer_cb() runs in hrtimer_run_softirq. It doesn't migrate and
1130 	 * cannot be preempted by another bpf_timer_cb() on the same cpu.
1131 	 * Remember the timer this callback is servicing to prevent
1132 	 * deadlock if callback_fn() calls bpf_timer_cancel() or
1133 	 * bpf_map_delete_elem() on the same timer.
1134 	 */
1135 	this_cpu_write(hrtimer_running, t);
1136 	if (map->map_type == BPF_MAP_TYPE_ARRAY) {
1137 		struct bpf_array *array = container_of(map, struct bpf_array, map);
1138 
1139 		/* compute the key */
1140 		idx = ((char *)value - array->value) / array->elem_size;
1141 		key = &idx;
1142 	} else { /* hash or lru */
1143 		key = value - round_up(map->key_size, 8);
1144 	}
1145 
1146 	callback_fn((u64)(long)map, (u64)(long)key, (u64)(long)value, 0, 0);
1147 	/* The verifier checked that return value is zero. */
1148 
1149 	this_cpu_write(hrtimer_running, NULL);
1150 out:
1151 	return HRTIMER_NORESTART;
1152 }
1153 
BPF_CALL_3(bpf_timer_init,struct bpf_timer_kern *,timer,struct bpf_map *,map,u64,flags)1154 BPF_CALL_3(bpf_timer_init, struct bpf_timer_kern *, timer, struct bpf_map *, map,
1155 	   u64, flags)
1156 {
1157 	clockid_t clockid = flags & (MAX_CLOCKS - 1);
1158 	struct bpf_hrtimer *t;
1159 	int ret = 0;
1160 
1161 	BUILD_BUG_ON(MAX_CLOCKS != 16);
1162 	BUILD_BUG_ON(sizeof(struct bpf_timer_kern) > sizeof(struct bpf_timer));
1163 	BUILD_BUG_ON(__alignof__(struct bpf_timer_kern) != __alignof__(struct bpf_timer));
1164 
1165 	if (in_nmi())
1166 		return -EOPNOTSUPP;
1167 
1168 	if (flags >= MAX_CLOCKS ||
1169 	    /* similar to timerfd except _ALARM variants are not supported */
1170 	    (clockid != CLOCK_MONOTONIC &&
1171 	     clockid != CLOCK_REALTIME &&
1172 	     clockid != CLOCK_BOOTTIME))
1173 		return -EINVAL;
1174 	__bpf_spin_lock_irqsave(&timer->lock);
1175 	t = timer->timer;
1176 	if (t) {
1177 		ret = -EBUSY;
1178 		goto out;
1179 	}
1180 	if (!atomic64_read(&map->usercnt)) {
1181 		/* maps with timers must be either held by user space
1182 		 * or pinned in bpffs.
1183 		 */
1184 		ret = -EPERM;
1185 		goto out;
1186 	}
1187 	/* allocate hrtimer via map_kmalloc to use memcg accounting */
1188 	t = bpf_map_kmalloc_node(map, sizeof(*t), GFP_ATOMIC, map->numa_node);
1189 	if (!t) {
1190 		ret = -ENOMEM;
1191 		goto out;
1192 	}
1193 	t->value = (void *)timer - map->timer_off;
1194 	t->map = map;
1195 	t->prog = NULL;
1196 	rcu_assign_pointer(t->callback_fn, NULL);
1197 	hrtimer_init(&t->timer, clockid, HRTIMER_MODE_REL_SOFT);
1198 	t->timer.function = bpf_timer_cb;
1199 	timer->timer = t;
1200 out:
1201 	__bpf_spin_unlock_irqrestore(&timer->lock);
1202 	return ret;
1203 }
1204 
1205 static const struct bpf_func_proto bpf_timer_init_proto = {
1206 	.func		= bpf_timer_init,
1207 	.gpl_only	= true,
1208 	.ret_type	= RET_INTEGER,
1209 	.arg1_type	= ARG_PTR_TO_TIMER,
1210 	.arg2_type	= ARG_CONST_MAP_PTR,
1211 	.arg3_type	= ARG_ANYTHING,
1212 };
1213 
BPF_CALL_3(bpf_timer_set_callback,struct bpf_timer_kern *,timer,void *,callback_fn,struct bpf_prog_aux *,aux)1214 BPF_CALL_3(bpf_timer_set_callback, struct bpf_timer_kern *, timer, void *, callback_fn,
1215 	   struct bpf_prog_aux *, aux)
1216 {
1217 	struct bpf_prog *prev, *prog = aux->prog;
1218 	struct bpf_hrtimer *t;
1219 	int ret = 0;
1220 
1221 	if (in_nmi())
1222 		return -EOPNOTSUPP;
1223 	__bpf_spin_lock_irqsave(&timer->lock);
1224 	t = timer->timer;
1225 	if (!t) {
1226 		ret = -EINVAL;
1227 		goto out;
1228 	}
1229 	if (!atomic64_read(&t->map->usercnt)) {
1230 		/* maps with timers must be either held by user space
1231 		 * or pinned in bpffs. Otherwise timer might still be
1232 		 * running even when bpf prog is detached and user space
1233 		 * is gone, since map_release_uref won't ever be called.
1234 		 */
1235 		ret = -EPERM;
1236 		goto out;
1237 	}
1238 	prev = t->prog;
1239 	if (prev != prog) {
1240 		/* Bump prog refcnt once. Every bpf_timer_set_callback()
1241 		 * can pick different callback_fn-s within the same prog.
1242 		 */
1243 		prog = bpf_prog_inc_not_zero(prog);
1244 		if (IS_ERR(prog)) {
1245 			ret = PTR_ERR(prog);
1246 			goto out;
1247 		}
1248 		if (prev)
1249 			/* Drop prev prog refcnt when swapping with new prog */
1250 			bpf_prog_put(prev);
1251 		t->prog = prog;
1252 	}
1253 	rcu_assign_pointer(t->callback_fn, callback_fn);
1254 out:
1255 	__bpf_spin_unlock_irqrestore(&timer->lock);
1256 	return ret;
1257 }
1258 
1259 static const struct bpf_func_proto bpf_timer_set_callback_proto = {
1260 	.func		= bpf_timer_set_callback,
1261 	.gpl_only	= true,
1262 	.ret_type	= RET_INTEGER,
1263 	.arg1_type	= ARG_PTR_TO_TIMER,
1264 	.arg2_type	= ARG_PTR_TO_FUNC,
1265 };
1266 
BPF_CALL_3(bpf_timer_start,struct bpf_timer_kern *,timer,u64,nsecs,u64,flags)1267 BPF_CALL_3(bpf_timer_start, struct bpf_timer_kern *, timer, u64, nsecs, u64, flags)
1268 {
1269 	struct bpf_hrtimer *t;
1270 	int ret = 0;
1271 
1272 	if (in_nmi())
1273 		return -EOPNOTSUPP;
1274 	if (flags)
1275 		return -EINVAL;
1276 	__bpf_spin_lock_irqsave(&timer->lock);
1277 	t = timer->timer;
1278 	if (!t || !t->prog) {
1279 		ret = -EINVAL;
1280 		goto out;
1281 	}
1282 	hrtimer_start(&t->timer, ns_to_ktime(nsecs), HRTIMER_MODE_REL_SOFT);
1283 out:
1284 	__bpf_spin_unlock_irqrestore(&timer->lock);
1285 	return ret;
1286 }
1287 
1288 static const struct bpf_func_proto bpf_timer_start_proto = {
1289 	.func		= bpf_timer_start,
1290 	.gpl_only	= true,
1291 	.ret_type	= RET_INTEGER,
1292 	.arg1_type	= ARG_PTR_TO_TIMER,
1293 	.arg2_type	= ARG_ANYTHING,
1294 	.arg3_type	= ARG_ANYTHING,
1295 };
1296 
drop_prog_refcnt(struct bpf_hrtimer * t)1297 static void drop_prog_refcnt(struct bpf_hrtimer *t)
1298 {
1299 	struct bpf_prog *prog = t->prog;
1300 
1301 	if (prog) {
1302 		bpf_prog_put(prog);
1303 		t->prog = NULL;
1304 		rcu_assign_pointer(t->callback_fn, NULL);
1305 	}
1306 }
1307 
BPF_CALL_1(bpf_timer_cancel,struct bpf_timer_kern *,timer)1308 BPF_CALL_1(bpf_timer_cancel, struct bpf_timer_kern *, timer)
1309 {
1310 	struct bpf_hrtimer *t;
1311 	int ret = 0;
1312 
1313 	if (in_nmi())
1314 		return -EOPNOTSUPP;
1315 	__bpf_spin_lock_irqsave(&timer->lock);
1316 	t = timer->timer;
1317 	if (!t) {
1318 		ret = -EINVAL;
1319 		goto out;
1320 	}
1321 	if (this_cpu_read(hrtimer_running) == t) {
1322 		/* If bpf callback_fn is trying to bpf_timer_cancel()
1323 		 * its own timer the hrtimer_cancel() will deadlock
1324 		 * since it waits for callback_fn to finish
1325 		 */
1326 		ret = -EDEADLK;
1327 		goto out;
1328 	}
1329 	drop_prog_refcnt(t);
1330 out:
1331 	__bpf_spin_unlock_irqrestore(&timer->lock);
1332 	/* Cancel the timer and wait for associated callback to finish
1333 	 * if it was running.
1334 	 */
1335 	ret = ret ?: hrtimer_cancel(&t->timer);
1336 	return ret;
1337 }
1338 
1339 static const struct bpf_func_proto bpf_timer_cancel_proto = {
1340 	.func		= bpf_timer_cancel,
1341 	.gpl_only	= true,
1342 	.ret_type	= RET_INTEGER,
1343 	.arg1_type	= ARG_PTR_TO_TIMER,
1344 };
1345 
1346 /* This function is called by map_delete/update_elem for individual element and
1347  * by ops->map_release_uref when the user space reference to a map reaches zero.
1348  */
bpf_timer_cancel_and_free(void * val)1349 void bpf_timer_cancel_and_free(void *val)
1350 {
1351 	struct bpf_timer_kern *timer = val;
1352 	struct bpf_hrtimer *t;
1353 
1354 	/* Performance optimization: read timer->timer without lock first. */
1355 	if (!READ_ONCE(timer->timer))
1356 		return;
1357 
1358 	__bpf_spin_lock_irqsave(&timer->lock);
1359 	/* re-read it under lock */
1360 	t = timer->timer;
1361 	if (!t)
1362 		goto out;
1363 	drop_prog_refcnt(t);
1364 	/* The subsequent bpf_timer_start/cancel() helpers won't be able to use
1365 	 * this timer, since it won't be initialized.
1366 	 */
1367 	timer->timer = NULL;
1368 out:
1369 	__bpf_spin_unlock_irqrestore(&timer->lock);
1370 	if (!t)
1371 		return;
1372 	/* Cancel the timer and wait for callback to complete if it was running.
1373 	 * If hrtimer_cancel() can be safely called it's safe to call kfree(t)
1374 	 * right after for both preallocated and non-preallocated maps.
1375 	 * The timer->timer = NULL was already done and no code path can
1376 	 * see address 't' anymore.
1377 	 *
1378 	 * Check that bpf_map_delete/update_elem() wasn't called from timer
1379 	 * callback_fn. In such case don't call hrtimer_cancel() (since it will
1380 	 * deadlock) and don't call hrtimer_try_to_cancel() (since it will just
1381 	 * return -1). Though callback_fn is still running on this cpu it's
1382 	 * safe to do kfree(t) because bpf_timer_cb() read everything it needed
1383 	 * from 't'. The bpf subprog callback_fn won't be able to access 't',
1384 	 * since timer->timer = NULL was already done. The timer will be
1385 	 * effectively cancelled because bpf_timer_cb() will return
1386 	 * HRTIMER_NORESTART.
1387 	 */
1388 	if (this_cpu_read(hrtimer_running) != t)
1389 		hrtimer_cancel(&t->timer);
1390 	kfree(t);
1391 }
1392 
BPF_CALL_2(bpf_kptr_xchg,void *,map_value,void *,ptr)1393 BPF_CALL_2(bpf_kptr_xchg, void *, map_value, void *, ptr)
1394 {
1395 	unsigned long *kptr = map_value;
1396 
1397 	return xchg(kptr, (unsigned long)ptr);
1398 }
1399 
1400 /* Unlike other PTR_TO_BTF_ID helpers the btf_id in bpf_kptr_xchg()
1401  * helper is determined dynamically by the verifier.
1402  */
1403 #define BPF_PTR_POISON ((void *)((0xeB9FUL << 2) + POISON_POINTER_DELTA))
1404 
1405 const struct bpf_func_proto bpf_kptr_xchg_proto = {
1406 	.func         = bpf_kptr_xchg,
1407 	.gpl_only     = false,
1408 	.ret_type     = RET_PTR_TO_BTF_ID_OR_NULL,
1409 	.ret_btf_id   = BPF_PTR_POISON,
1410 	.arg1_type    = ARG_PTR_TO_KPTR,
1411 	.arg2_type    = ARG_PTR_TO_BTF_ID_OR_NULL | OBJ_RELEASE,
1412 	.arg2_btf_id  = BPF_PTR_POISON,
1413 };
1414 
1415 /* Since the upper 8 bits of dynptr->size is reserved, the
1416  * maximum supported size is 2^24 - 1.
1417  */
1418 #define DYNPTR_MAX_SIZE	((1UL << 24) - 1)
1419 #define DYNPTR_TYPE_SHIFT	28
1420 #define DYNPTR_SIZE_MASK	0xFFFFFF
1421 #define DYNPTR_RDONLY_BIT	BIT(31)
1422 
bpf_dynptr_is_rdonly(struct bpf_dynptr_kern * ptr)1423 static bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr)
1424 {
1425 	return ptr->size & DYNPTR_RDONLY_BIT;
1426 }
1427 
bpf_dynptr_set_type(struct bpf_dynptr_kern * ptr,enum bpf_dynptr_type type)1428 static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_type type)
1429 {
1430 	ptr->size |= type << DYNPTR_TYPE_SHIFT;
1431 }
1432 
bpf_dynptr_get_size(struct bpf_dynptr_kern * ptr)1433 static u32 bpf_dynptr_get_size(struct bpf_dynptr_kern *ptr)
1434 {
1435 	return ptr->size & DYNPTR_SIZE_MASK;
1436 }
1437 
bpf_dynptr_check_size(u32 size)1438 int bpf_dynptr_check_size(u32 size)
1439 {
1440 	return size > DYNPTR_MAX_SIZE ? -E2BIG : 0;
1441 }
1442 
bpf_dynptr_init(struct bpf_dynptr_kern * ptr,void * data,enum bpf_dynptr_type type,u32 offset,u32 size)1443 void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
1444 		     enum bpf_dynptr_type type, u32 offset, u32 size)
1445 {
1446 	ptr->data = data;
1447 	ptr->offset = offset;
1448 	ptr->size = size;
1449 	bpf_dynptr_set_type(ptr, type);
1450 }
1451 
bpf_dynptr_set_null(struct bpf_dynptr_kern * ptr)1452 void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr)
1453 {
1454 	memset(ptr, 0, sizeof(*ptr));
1455 }
1456 
bpf_dynptr_check_off_len(struct bpf_dynptr_kern * ptr,u32 offset,u32 len)1457 static int bpf_dynptr_check_off_len(struct bpf_dynptr_kern *ptr, u32 offset, u32 len)
1458 {
1459 	u32 size = bpf_dynptr_get_size(ptr);
1460 
1461 	if (len > size || offset > size - len)
1462 		return -E2BIG;
1463 
1464 	return 0;
1465 }
1466 
BPF_CALL_4(bpf_dynptr_from_mem,void *,data,u32,size,u64,flags,struct bpf_dynptr_kern *,ptr)1467 BPF_CALL_4(bpf_dynptr_from_mem, void *, data, u32, size, u64, flags, struct bpf_dynptr_kern *, ptr)
1468 {
1469 	int err;
1470 
1471 	err = bpf_dynptr_check_size(size);
1472 	if (err)
1473 		goto error;
1474 
1475 	/* flags is currently unsupported */
1476 	if (flags) {
1477 		err = -EINVAL;
1478 		goto error;
1479 	}
1480 
1481 	bpf_dynptr_init(ptr, data, BPF_DYNPTR_TYPE_LOCAL, 0, size);
1482 
1483 	return 0;
1484 
1485 error:
1486 	bpf_dynptr_set_null(ptr);
1487 	return err;
1488 }
1489 
1490 const struct bpf_func_proto bpf_dynptr_from_mem_proto = {
1491 	.func		= bpf_dynptr_from_mem,
1492 	.gpl_only	= false,
1493 	.ret_type	= RET_INTEGER,
1494 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1495 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1496 	.arg3_type	= ARG_ANYTHING,
1497 	.arg4_type	= ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL | MEM_UNINIT,
1498 };
1499 
BPF_CALL_5(bpf_dynptr_read,void *,dst,u32,len,struct bpf_dynptr_kern *,src,u32,offset,u64,flags)1500 BPF_CALL_5(bpf_dynptr_read, void *, dst, u32, len, struct bpf_dynptr_kern *, src,
1501 	   u32, offset, u64, flags)
1502 {
1503 	int err;
1504 
1505 	if (!src->data || flags)
1506 		return -EINVAL;
1507 
1508 	err = bpf_dynptr_check_off_len(src, offset, len);
1509 	if (err)
1510 		return err;
1511 
1512 	memcpy(dst, src->data + src->offset + offset, len);
1513 
1514 	return 0;
1515 }
1516 
1517 const struct bpf_func_proto bpf_dynptr_read_proto = {
1518 	.func		= bpf_dynptr_read,
1519 	.gpl_only	= false,
1520 	.ret_type	= RET_INTEGER,
1521 	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
1522 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
1523 	.arg3_type	= ARG_PTR_TO_DYNPTR,
1524 	.arg4_type	= ARG_ANYTHING,
1525 	.arg5_type	= ARG_ANYTHING,
1526 };
1527 
BPF_CALL_5(bpf_dynptr_write,struct bpf_dynptr_kern *,dst,u32,offset,void *,src,u32,len,u64,flags)1528 BPF_CALL_5(bpf_dynptr_write, struct bpf_dynptr_kern *, dst, u32, offset, void *, src,
1529 	   u32, len, u64, flags)
1530 {
1531 	int err;
1532 
1533 	if (!dst->data || flags || bpf_dynptr_is_rdonly(dst))
1534 		return -EINVAL;
1535 
1536 	err = bpf_dynptr_check_off_len(dst, offset, len);
1537 	if (err)
1538 		return err;
1539 
1540 	memcpy(dst->data + dst->offset + offset, src, len);
1541 
1542 	return 0;
1543 }
1544 
1545 const struct bpf_func_proto bpf_dynptr_write_proto = {
1546 	.func		= bpf_dynptr_write,
1547 	.gpl_only	= false,
1548 	.ret_type	= RET_INTEGER,
1549 	.arg1_type	= ARG_PTR_TO_DYNPTR,
1550 	.arg2_type	= ARG_ANYTHING,
1551 	.arg3_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
1552 	.arg4_type	= ARG_CONST_SIZE_OR_ZERO,
1553 	.arg5_type	= ARG_ANYTHING,
1554 };
1555 
BPF_CALL_3(bpf_dynptr_data,struct bpf_dynptr_kern *,ptr,u32,offset,u32,len)1556 BPF_CALL_3(bpf_dynptr_data, struct bpf_dynptr_kern *, ptr, u32, offset, u32, len)
1557 {
1558 	int err;
1559 
1560 	if (!ptr->data)
1561 		return 0;
1562 
1563 	err = bpf_dynptr_check_off_len(ptr, offset, len);
1564 	if (err)
1565 		return 0;
1566 
1567 	if (bpf_dynptr_is_rdonly(ptr))
1568 		return 0;
1569 
1570 	return (unsigned long)(ptr->data + ptr->offset + offset);
1571 }
1572 
1573 const struct bpf_func_proto bpf_dynptr_data_proto = {
1574 	.func		= bpf_dynptr_data,
1575 	.gpl_only	= false,
1576 	.ret_type	= RET_PTR_TO_DYNPTR_MEM_OR_NULL,
1577 	.arg1_type	= ARG_PTR_TO_DYNPTR,
1578 	.arg2_type	= ARG_ANYTHING,
1579 	.arg3_type	= ARG_CONST_ALLOC_SIZE_OR_ZERO,
1580 };
1581 
1582 const struct bpf_func_proto bpf_get_current_task_proto __weak;
1583 const struct bpf_func_proto bpf_get_current_task_btf_proto __weak;
1584 const struct bpf_func_proto bpf_probe_read_user_proto __weak;
1585 const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
1586 const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
1587 const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;
1588 const struct bpf_func_proto bpf_task_pt_regs_proto __weak;
1589 
1590 const struct bpf_func_proto *
bpf_base_func_proto(enum bpf_func_id func_id)1591 bpf_base_func_proto(enum bpf_func_id func_id)
1592 {
1593 	switch (func_id) {
1594 	case BPF_FUNC_map_lookup_elem:
1595 		return &bpf_map_lookup_elem_proto;
1596 	case BPF_FUNC_map_update_elem:
1597 		return &bpf_map_update_elem_proto;
1598 	case BPF_FUNC_map_delete_elem:
1599 		return &bpf_map_delete_elem_proto;
1600 	case BPF_FUNC_map_push_elem:
1601 		return &bpf_map_push_elem_proto;
1602 	case BPF_FUNC_map_pop_elem:
1603 		return &bpf_map_pop_elem_proto;
1604 	case BPF_FUNC_map_peek_elem:
1605 		return &bpf_map_peek_elem_proto;
1606 	case BPF_FUNC_map_lookup_percpu_elem:
1607 		return &bpf_map_lookup_percpu_elem_proto;
1608 	case BPF_FUNC_get_prandom_u32:
1609 		return &bpf_get_prandom_u32_proto;
1610 	case BPF_FUNC_get_smp_processor_id:
1611 		return &bpf_get_raw_smp_processor_id_proto;
1612 	case BPF_FUNC_get_numa_node_id:
1613 		return &bpf_get_numa_node_id_proto;
1614 	case BPF_FUNC_tail_call:
1615 		return &bpf_tail_call_proto;
1616 	case BPF_FUNC_ktime_get_ns:
1617 		return &bpf_ktime_get_ns_proto;
1618 	case BPF_FUNC_ktime_get_boot_ns:
1619 		return &bpf_ktime_get_boot_ns_proto;
1620 	case BPF_FUNC_ringbuf_output:
1621 		return &bpf_ringbuf_output_proto;
1622 	case BPF_FUNC_ringbuf_reserve:
1623 		return &bpf_ringbuf_reserve_proto;
1624 	case BPF_FUNC_ringbuf_submit:
1625 		return &bpf_ringbuf_submit_proto;
1626 	case BPF_FUNC_ringbuf_discard:
1627 		return &bpf_ringbuf_discard_proto;
1628 	case BPF_FUNC_ringbuf_query:
1629 		return &bpf_ringbuf_query_proto;
1630 	case BPF_FUNC_ringbuf_reserve_dynptr:
1631 		return &bpf_ringbuf_reserve_dynptr_proto;
1632 	case BPF_FUNC_ringbuf_submit_dynptr:
1633 		return &bpf_ringbuf_submit_dynptr_proto;
1634 	case BPF_FUNC_ringbuf_discard_dynptr:
1635 		return &bpf_ringbuf_discard_dynptr_proto;
1636 	case BPF_FUNC_for_each_map_elem:
1637 		return &bpf_for_each_map_elem_proto;
1638 	case BPF_FUNC_loop:
1639 		return &bpf_loop_proto;
1640 	case BPF_FUNC_strncmp:
1641 		return &bpf_strncmp_proto;
1642 	case BPF_FUNC_dynptr_from_mem:
1643 		return &bpf_dynptr_from_mem_proto;
1644 	case BPF_FUNC_dynptr_read:
1645 		return &bpf_dynptr_read_proto;
1646 	case BPF_FUNC_dynptr_write:
1647 		return &bpf_dynptr_write_proto;
1648 	case BPF_FUNC_dynptr_data:
1649 		return &bpf_dynptr_data_proto;
1650 	default:
1651 		break;
1652 	}
1653 
1654 	if (!bpf_capable())
1655 		return NULL;
1656 
1657 	switch (func_id) {
1658 	case BPF_FUNC_spin_lock:
1659 		return &bpf_spin_lock_proto;
1660 	case BPF_FUNC_spin_unlock:
1661 		return &bpf_spin_unlock_proto;
1662 	case BPF_FUNC_jiffies64:
1663 		return &bpf_jiffies64_proto;
1664 	case BPF_FUNC_per_cpu_ptr:
1665 		return &bpf_per_cpu_ptr_proto;
1666 	case BPF_FUNC_this_cpu_ptr:
1667 		return &bpf_this_cpu_ptr_proto;
1668 	case BPF_FUNC_timer_init:
1669 		return &bpf_timer_init_proto;
1670 	case BPF_FUNC_timer_set_callback:
1671 		return &bpf_timer_set_callback_proto;
1672 	case BPF_FUNC_timer_start:
1673 		return &bpf_timer_start_proto;
1674 	case BPF_FUNC_timer_cancel:
1675 		return &bpf_timer_cancel_proto;
1676 	case BPF_FUNC_kptr_xchg:
1677 		return &bpf_kptr_xchg_proto;
1678 	default:
1679 		break;
1680 	}
1681 
1682 	if (!perfmon_capable())
1683 		return NULL;
1684 
1685 	switch (func_id) {
1686 	case BPF_FUNC_trace_printk:
1687 		return bpf_get_trace_printk_proto();
1688 	case BPF_FUNC_get_current_task:
1689 		return &bpf_get_current_task_proto;
1690 	case BPF_FUNC_get_current_task_btf:
1691 		return &bpf_get_current_task_btf_proto;
1692 	case BPF_FUNC_probe_read_user:
1693 		return &bpf_probe_read_user_proto;
1694 	case BPF_FUNC_probe_read_kernel:
1695 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1696 		       NULL : &bpf_probe_read_kernel_proto;
1697 	case BPF_FUNC_probe_read_user_str:
1698 		return &bpf_probe_read_user_str_proto;
1699 	case BPF_FUNC_probe_read_kernel_str:
1700 		return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
1701 		       NULL : &bpf_probe_read_kernel_str_proto;
1702 	case BPF_FUNC_snprintf_btf:
1703 		return &bpf_snprintf_btf_proto;
1704 	case BPF_FUNC_snprintf:
1705 		return &bpf_snprintf_proto;
1706 	case BPF_FUNC_task_pt_regs:
1707 		return &bpf_task_pt_regs_proto;
1708 	case BPF_FUNC_trace_vprintk:
1709 		return bpf_get_trace_vprintk_proto();
1710 	default:
1711 		return NULL;
1712 	}
1713 }
1714