xref: /openbmc/linux/kernel/bpf/syscall.c (revision 6b5fc336)
1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
2  *
3  * This program is free software; you can redistribute it and/or
4  * modify it under the terms of version 2 of the GNU General Public
5  * License as published by the Free Software Foundation.
6  *
7  * This program is distributed in the hope that it will be useful, but
8  * WITHOUT ANY WARRANTY; without even the implied warranty of
9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10  * General Public License for more details.
11  */
12 #include <linux/bpf.h>
13 #include <linux/bpf_trace.h>
14 #include <linux/syscalls.h>
15 #include <linux/slab.h>
16 #include <linux/sched/signal.h>
17 #include <linux/vmalloc.h>
18 #include <linux/mmzone.h>
19 #include <linux/anon_inodes.h>
20 #include <linux/file.h>
21 #include <linux/license.h>
22 #include <linux/filter.h>
23 #include <linux/version.h>
24 #include <linux/kernel.h>
25 #include <linux/idr.h>
26 
27 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
28 			   (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
29 			   (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
30 			   (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
31 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
32 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map))
33 
34 DEFINE_PER_CPU(int, bpf_prog_active);
35 static DEFINE_IDR(prog_idr);
36 static DEFINE_SPINLOCK(prog_idr_lock);
37 static DEFINE_IDR(map_idr);
38 static DEFINE_SPINLOCK(map_idr_lock);
39 
40 int sysctl_unprivileged_bpf_disabled __read_mostly;
41 
42 static const struct bpf_map_ops * const bpf_map_types[] = {
43 #define BPF_PROG_TYPE(_id, _ops)
44 #define BPF_MAP_TYPE(_id, _ops) \
45 	[_id] = &_ops,
46 #include <linux/bpf_types.h>
47 #undef BPF_PROG_TYPE
48 #undef BPF_MAP_TYPE
49 };
50 
51 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
52 {
53 	struct bpf_map *map;
54 
55 	if (attr->map_type >= ARRAY_SIZE(bpf_map_types) ||
56 	    !bpf_map_types[attr->map_type])
57 		return ERR_PTR(-EINVAL);
58 
59 	map = bpf_map_types[attr->map_type]->map_alloc(attr);
60 	if (IS_ERR(map))
61 		return map;
62 	map->ops = bpf_map_types[attr->map_type];
63 	map->map_type = attr->map_type;
64 	return map;
65 }
66 
67 void *bpf_map_area_alloc(size_t size)
68 {
69 	/* We definitely need __GFP_NORETRY, so OOM killer doesn't
70 	 * trigger under memory pressure as we really just want to
71 	 * fail instead.
72 	 */
73 	const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
74 	void *area;
75 
76 	if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
77 		area = kmalloc(size, GFP_USER | flags);
78 		if (area != NULL)
79 			return area;
80 	}
81 
82 	return __vmalloc(size, GFP_KERNEL | flags, PAGE_KERNEL);
83 }
84 
85 void bpf_map_area_free(void *area)
86 {
87 	kvfree(area);
88 }
89 
90 int bpf_map_precharge_memlock(u32 pages)
91 {
92 	struct user_struct *user = get_current_user();
93 	unsigned long memlock_limit, cur;
94 
95 	memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
96 	cur = atomic_long_read(&user->locked_vm);
97 	free_uid(user);
98 	if (cur + pages > memlock_limit)
99 		return -EPERM;
100 	return 0;
101 }
102 
103 static int bpf_map_charge_memlock(struct bpf_map *map)
104 {
105 	struct user_struct *user = get_current_user();
106 	unsigned long memlock_limit;
107 
108 	memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
109 
110 	atomic_long_add(map->pages, &user->locked_vm);
111 
112 	if (atomic_long_read(&user->locked_vm) > memlock_limit) {
113 		atomic_long_sub(map->pages, &user->locked_vm);
114 		free_uid(user);
115 		return -EPERM;
116 	}
117 	map->user = user;
118 	return 0;
119 }
120 
121 static void bpf_map_uncharge_memlock(struct bpf_map *map)
122 {
123 	struct user_struct *user = map->user;
124 
125 	atomic_long_sub(map->pages, &user->locked_vm);
126 	free_uid(user);
127 }
128 
129 static int bpf_map_alloc_id(struct bpf_map *map)
130 {
131 	int id;
132 
133 	spin_lock_bh(&map_idr_lock);
134 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
135 	if (id > 0)
136 		map->id = id;
137 	spin_unlock_bh(&map_idr_lock);
138 
139 	if (WARN_ON_ONCE(!id))
140 		return -ENOSPC;
141 
142 	return id > 0 ? 0 : id;
143 }
144 
145 static void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
146 {
147 	if (do_idr_lock)
148 		spin_lock_bh(&map_idr_lock);
149 	else
150 		__acquire(&map_idr_lock);
151 
152 	idr_remove(&map_idr, map->id);
153 
154 	if (do_idr_lock)
155 		spin_unlock_bh(&map_idr_lock);
156 	else
157 		__release(&map_idr_lock);
158 }
159 
160 /* called from workqueue */
161 static void bpf_map_free_deferred(struct work_struct *work)
162 {
163 	struct bpf_map *map = container_of(work, struct bpf_map, work);
164 
165 	bpf_map_uncharge_memlock(map);
166 	/* implementation dependent freeing */
167 	map->ops->map_free(map);
168 }
169 
170 static void bpf_map_put_uref(struct bpf_map *map)
171 {
172 	if (atomic_dec_and_test(&map->usercnt)) {
173 		if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
174 			bpf_fd_array_map_clear(map);
175 	}
176 }
177 
178 /* decrement map refcnt and schedule it for freeing via workqueue
179  * (unrelying map implementation ops->map_free() might sleep)
180  */
181 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
182 {
183 	if (atomic_dec_and_test(&map->refcnt)) {
184 		/* bpf_map_free_id() must be called first */
185 		bpf_map_free_id(map, do_idr_lock);
186 		INIT_WORK(&map->work, bpf_map_free_deferred);
187 		schedule_work(&map->work);
188 	}
189 }
190 
191 void bpf_map_put(struct bpf_map *map)
192 {
193 	__bpf_map_put(map, true);
194 }
195 
196 void bpf_map_put_with_uref(struct bpf_map *map)
197 {
198 	bpf_map_put_uref(map);
199 	bpf_map_put(map);
200 }
201 
202 static int bpf_map_release(struct inode *inode, struct file *filp)
203 {
204 	struct bpf_map *map = filp->private_data;
205 
206 	if (map->ops->map_release)
207 		map->ops->map_release(map, filp);
208 
209 	bpf_map_put_with_uref(map);
210 	return 0;
211 }
212 
213 #ifdef CONFIG_PROC_FS
214 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
215 {
216 	const struct bpf_map *map = filp->private_data;
217 	const struct bpf_array *array;
218 	u32 owner_prog_type = 0;
219 	u32 owner_jited = 0;
220 
221 	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
222 		array = container_of(map, struct bpf_array, map);
223 		owner_prog_type = array->owner_prog_type;
224 		owner_jited = array->owner_jited;
225 	}
226 
227 	seq_printf(m,
228 		   "map_type:\t%u\n"
229 		   "key_size:\t%u\n"
230 		   "value_size:\t%u\n"
231 		   "max_entries:\t%u\n"
232 		   "map_flags:\t%#x\n"
233 		   "memlock:\t%llu\n",
234 		   map->map_type,
235 		   map->key_size,
236 		   map->value_size,
237 		   map->max_entries,
238 		   map->map_flags,
239 		   map->pages * 1ULL << PAGE_SHIFT);
240 
241 	if (owner_prog_type) {
242 		seq_printf(m, "owner_prog_type:\t%u\n",
243 			   owner_prog_type);
244 		seq_printf(m, "owner_jited:\t%u\n",
245 			   owner_jited);
246 	}
247 }
248 #endif
249 
250 static const struct file_operations bpf_map_fops = {
251 #ifdef CONFIG_PROC_FS
252 	.show_fdinfo	= bpf_map_show_fdinfo,
253 #endif
254 	.release	= bpf_map_release,
255 };
256 
257 int bpf_map_new_fd(struct bpf_map *map)
258 {
259 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
260 				O_RDWR | O_CLOEXEC);
261 }
262 
263 /* helper macro to check that unused fields 'union bpf_attr' are zero */
264 #define CHECK_ATTR(CMD) \
265 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
266 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
267 		   sizeof(*attr) - \
268 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
269 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
270 
271 #define BPF_MAP_CREATE_LAST_FIELD inner_map_fd
272 /* called via syscall */
273 static int map_create(union bpf_attr *attr)
274 {
275 	struct bpf_map *map;
276 	int err;
277 
278 	err = CHECK_ATTR(BPF_MAP_CREATE);
279 	if (err)
280 		return -EINVAL;
281 
282 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
283 	map = find_and_alloc_map(attr);
284 	if (IS_ERR(map))
285 		return PTR_ERR(map);
286 
287 	atomic_set(&map->refcnt, 1);
288 	atomic_set(&map->usercnt, 1);
289 
290 	err = bpf_map_charge_memlock(map);
291 	if (err)
292 		goto free_map_nouncharge;
293 
294 	err = bpf_map_alloc_id(map);
295 	if (err)
296 		goto free_map;
297 
298 	err = bpf_map_new_fd(map);
299 	if (err < 0) {
300 		/* failed to allocate fd.
301 		 * bpf_map_put() is needed because the above
302 		 * bpf_map_alloc_id() has published the map
303 		 * to the userspace and the userspace may
304 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
305 		 */
306 		bpf_map_put(map);
307 		return err;
308 	}
309 
310 	trace_bpf_map_create(map, err);
311 	return err;
312 
313 free_map:
314 	bpf_map_uncharge_memlock(map);
315 free_map_nouncharge:
316 	map->ops->map_free(map);
317 	return err;
318 }
319 
320 /* if error is returned, fd is released.
321  * On success caller should complete fd access with matching fdput()
322  */
323 struct bpf_map *__bpf_map_get(struct fd f)
324 {
325 	if (!f.file)
326 		return ERR_PTR(-EBADF);
327 	if (f.file->f_op != &bpf_map_fops) {
328 		fdput(f);
329 		return ERR_PTR(-EINVAL);
330 	}
331 
332 	return f.file->private_data;
333 }
334 
335 /* prog's and map's refcnt limit */
336 #define BPF_MAX_REFCNT 32768
337 
338 struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
339 {
340 	if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
341 		atomic_dec(&map->refcnt);
342 		return ERR_PTR(-EBUSY);
343 	}
344 	if (uref)
345 		atomic_inc(&map->usercnt);
346 	return map;
347 }
348 
349 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
350 {
351 	struct fd f = fdget(ufd);
352 	struct bpf_map *map;
353 
354 	map = __bpf_map_get(f);
355 	if (IS_ERR(map))
356 		return map;
357 
358 	map = bpf_map_inc(map, true);
359 	fdput(f);
360 
361 	return map;
362 }
363 
364 /* map_idr_lock should have been held */
365 static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map,
366 					    bool uref)
367 {
368 	int refold;
369 
370 	refold = __atomic_add_unless(&map->refcnt, 1, 0);
371 
372 	if (refold >= BPF_MAX_REFCNT) {
373 		__bpf_map_put(map, false);
374 		return ERR_PTR(-EBUSY);
375 	}
376 
377 	if (!refold)
378 		return ERR_PTR(-ENOENT);
379 
380 	if (uref)
381 		atomic_inc(&map->usercnt);
382 
383 	return map;
384 }
385 
386 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
387 {
388 	return -ENOTSUPP;
389 }
390 
391 /* last field in 'union bpf_attr' used by this command */
392 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
393 
394 static int map_lookup_elem(union bpf_attr *attr)
395 {
396 	void __user *ukey = u64_to_user_ptr(attr->key);
397 	void __user *uvalue = u64_to_user_ptr(attr->value);
398 	int ufd = attr->map_fd;
399 	struct bpf_map *map;
400 	void *key, *value, *ptr;
401 	u32 value_size;
402 	struct fd f;
403 	int err;
404 
405 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
406 		return -EINVAL;
407 
408 	f = fdget(ufd);
409 	map = __bpf_map_get(f);
410 	if (IS_ERR(map))
411 		return PTR_ERR(map);
412 
413 	key = memdup_user(ukey, map->key_size);
414 	if (IS_ERR(key)) {
415 		err = PTR_ERR(key);
416 		goto err_put;
417 	}
418 
419 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
420 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
421 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
422 		value_size = round_up(map->value_size, 8) * num_possible_cpus();
423 	else if (IS_FD_MAP(map))
424 		value_size = sizeof(u32);
425 	else
426 		value_size = map->value_size;
427 
428 	err = -ENOMEM;
429 	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
430 	if (!value)
431 		goto free_key;
432 
433 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
434 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
435 		err = bpf_percpu_hash_copy(map, key, value);
436 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
437 		err = bpf_percpu_array_copy(map, key, value);
438 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
439 		err = bpf_stackmap_copy(map, key, value);
440 	} else if (IS_FD_ARRAY(map)) {
441 		err = bpf_fd_array_map_lookup_elem(map, key, value);
442 	} else if (IS_FD_HASH(map)) {
443 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
444 	} else {
445 		rcu_read_lock();
446 		ptr = map->ops->map_lookup_elem(map, key);
447 		if (ptr)
448 			memcpy(value, ptr, value_size);
449 		rcu_read_unlock();
450 		err = ptr ? 0 : -ENOENT;
451 	}
452 
453 	if (err)
454 		goto free_value;
455 
456 	err = -EFAULT;
457 	if (copy_to_user(uvalue, value, value_size) != 0)
458 		goto free_value;
459 
460 	trace_bpf_map_lookup_elem(map, ufd, key, value);
461 	err = 0;
462 
463 free_value:
464 	kfree(value);
465 free_key:
466 	kfree(key);
467 err_put:
468 	fdput(f);
469 	return err;
470 }
471 
472 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
473 
474 static int map_update_elem(union bpf_attr *attr)
475 {
476 	void __user *ukey = u64_to_user_ptr(attr->key);
477 	void __user *uvalue = u64_to_user_ptr(attr->value);
478 	int ufd = attr->map_fd;
479 	struct bpf_map *map;
480 	void *key, *value;
481 	u32 value_size;
482 	struct fd f;
483 	int err;
484 
485 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
486 		return -EINVAL;
487 
488 	f = fdget(ufd);
489 	map = __bpf_map_get(f);
490 	if (IS_ERR(map))
491 		return PTR_ERR(map);
492 
493 	key = memdup_user(ukey, map->key_size);
494 	if (IS_ERR(key)) {
495 		err = PTR_ERR(key);
496 		goto err_put;
497 	}
498 
499 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
500 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
501 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
502 		value_size = round_up(map->value_size, 8) * num_possible_cpus();
503 	else
504 		value_size = map->value_size;
505 
506 	err = -ENOMEM;
507 	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
508 	if (!value)
509 		goto free_key;
510 
511 	err = -EFAULT;
512 	if (copy_from_user(value, uvalue, value_size) != 0)
513 		goto free_value;
514 
515 	/* must increment bpf_prog_active to avoid kprobe+bpf triggering from
516 	 * inside bpf map update or delete otherwise deadlocks are possible
517 	 */
518 	preempt_disable();
519 	__this_cpu_inc(bpf_prog_active);
520 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
521 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
522 		err = bpf_percpu_hash_update(map, key, value, attr->flags);
523 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
524 		err = bpf_percpu_array_update(map, key, value, attr->flags);
525 	} else if (map->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY ||
526 		   map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
527 		   map->map_type == BPF_MAP_TYPE_CGROUP_ARRAY ||
528 		   map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) {
529 		rcu_read_lock();
530 		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
531 						   attr->flags);
532 		rcu_read_unlock();
533 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
534 		rcu_read_lock();
535 		err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
536 						  attr->flags);
537 		rcu_read_unlock();
538 	} else {
539 		rcu_read_lock();
540 		err = map->ops->map_update_elem(map, key, value, attr->flags);
541 		rcu_read_unlock();
542 	}
543 	__this_cpu_dec(bpf_prog_active);
544 	preempt_enable();
545 
546 	if (!err)
547 		trace_bpf_map_update_elem(map, ufd, key, value);
548 free_value:
549 	kfree(value);
550 free_key:
551 	kfree(key);
552 err_put:
553 	fdput(f);
554 	return err;
555 }
556 
557 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
558 
559 static int map_delete_elem(union bpf_attr *attr)
560 {
561 	void __user *ukey = u64_to_user_ptr(attr->key);
562 	int ufd = attr->map_fd;
563 	struct bpf_map *map;
564 	struct fd f;
565 	void *key;
566 	int err;
567 
568 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
569 		return -EINVAL;
570 
571 	f = fdget(ufd);
572 	map = __bpf_map_get(f);
573 	if (IS_ERR(map))
574 		return PTR_ERR(map);
575 
576 	key = memdup_user(ukey, map->key_size);
577 	if (IS_ERR(key)) {
578 		err = PTR_ERR(key);
579 		goto err_put;
580 	}
581 
582 	preempt_disable();
583 	__this_cpu_inc(bpf_prog_active);
584 	rcu_read_lock();
585 	err = map->ops->map_delete_elem(map, key);
586 	rcu_read_unlock();
587 	__this_cpu_dec(bpf_prog_active);
588 	preempt_enable();
589 
590 	if (!err)
591 		trace_bpf_map_delete_elem(map, ufd, key);
592 	kfree(key);
593 err_put:
594 	fdput(f);
595 	return err;
596 }
597 
598 /* last field in 'union bpf_attr' used by this command */
599 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
600 
601 static int map_get_next_key(union bpf_attr *attr)
602 {
603 	void __user *ukey = u64_to_user_ptr(attr->key);
604 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
605 	int ufd = attr->map_fd;
606 	struct bpf_map *map;
607 	void *key, *next_key;
608 	struct fd f;
609 	int err;
610 
611 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
612 		return -EINVAL;
613 
614 	f = fdget(ufd);
615 	map = __bpf_map_get(f);
616 	if (IS_ERR(map))
617 		return PTR_ERR(map);
618 
619 	if (ukey) {
620 		key = memdup_user(ukey, map->key_size);
621 		if (IS_ERR(key)) {
622 			err = PTR_ERR(key);
623 			goto err_put;
624 		}
625 	} else {
626 		key = NULL;
627 	}
628 
629 	err = -ENOMEM;
630 	next_key = kmalloc(map->key_size, GFP_USER);
631 	if (!next_key)
632 		goto free_key;
633 
634 	rcu_read_lock();
635 	err = map->ops->map_get_next_key(map, key, next_key);
636 	rcu_read_unlock();
637 	if (err)
638 		goto free_next_key;
639 
640 	err = -EFAULT;
641 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
642 		goto free_next_key;
643 
644 	trace_bpf_map_next_key(map, ufd, key, next_key);
645 	err = 0;
646 
647 free_next_key:
648 	kfree(next_key);
649 free_key:
650 	kfree(key);
651 err_put:
652 	fdput(f);
653 	return err;
654 }
655 
656 static const struct bpf_verifier_ops * const bpf_prog_types[] = {
657 #define BPF_PROG_TYPE(_id, _ops) \
658 	[_id] = &_ops,
659 #define BPF_MAP_TYPE(_id, _ops)
660 #include <linux/bpf_types.h>
661 #undef BPF_PROG_TYPE
662 #undef BPF_MAP_TYPE
663 };
664 
665 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
666 {
667 	if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
668 		return -EINVAL;
669 
670 	prog->aux->ops = bpf_prog_types[type];
671 	prog->type = type;
672 	return 0;
673 }
674 
675 /* drop refcnt on maps used by eBPF program and free auxilary data */
676 static void free_used_maps(struct bpf_prog_aux *aux)
677 {
678 	int i;
679 
680 	for (i = 0; i < aux->used_map_cnt; i++)
681 		bpf_map_put(aux->used_maps[i]);
682 
683 	kfree(aux->used_maps);
684 }
685 
686 int __bpf_prog_charge(struct user_struct *user, u32 pages)
687 {
688 	unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
689 	unsigned long user_bufs;
690 
691 	if (user) {
692 		user_bufs = atomic_long_add_return(pages, &user->locked_vm);
693 		if (user_bufs > memlock_limit) {
694 			atomic_long_sub(pages, &user->locked_vm);
695 			return -EPERM;
696 		}
697 	}
698 
699 	return 0;
700 }
701 
702 void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
703 {
704 	if (user)
705 		atomic_long_sub(pages, &user->locked_vm);
706 }
707 
708 static int bpf_prog_charge_memlock(struct bpf_prog *prog)
709 {
710 	struct user_struct *user = get_current_user();
711 	int ret;
712 
713 	ret = __bpf_prog_charge(user, prog->pages);
714 	if (ret) {
715 		free_uid(user);
716 		return ret;
717 	}
718 
719 	prog->aux->user = user;
720 	return 0;
721 }
722 
723 static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
724 {
725 	struct user_struct *user = prog->aux->user;
726 
727 	__bpf_prog_uncharge(user, prog->pages);
728 	free_uid(user);
729 }
730 
731 static int bpf_prog_alloc_id(struct bpf_prog *prog)
732 {
733 	int id;
734 
735 	spin_lock_bh(&prog_idr_lock);
736 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
737 	if (id > 0)
738 		prog->aux->id = id;
739 	spin_unlock_bh(&prog_idr_lock);
740 
741 	/* id is in [1, INT_MAX) */
742 	if (WARN_ON_ONCE(!id))
743 		return -ENOSPC;
744 
745 	return id > 0 ? 0 : id;
746 }
747 
748 static void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
749 {
750 	/* cBPF to eBPF migrations are currently not in the idr store. */
751 	if (!prog->aux->id)
752 		return;
753 
754 	if (do_idr_lock)
755 		spin_lock_bh(&prog_idr_lock);
756 	else
757 		__acquire(&prog_idr_lock);
758 
759 	idr_remove(&prog_idr, prog->aux->id);
760 
761 	if (do_idr_lock)
762 		spin_unlock_bh(&prog_idr_lock);
763 	else
764 		__release(&prog_idr_lock);
765 }
766 
767 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
768 {
769 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
770 
771 	free_used_maps(aux);
772 	bpf_prog_uncharge_memlock(aux->prog);
773 	bpf_prog_free(aux->prog);
774 }
775 
776 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
777 {
778 	if (atomic_dec_and_test(&prog->aux->refcnt)) {
779 		trace_bpf_prog_put_rcu(prog);
780 		/* bpf_prog_free_id() must be called first */
781 		bpf_prog_free_id(prog, do_idr_lock);
782 		bpf_prog_kallsyms_del(prog);
783 		call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
784 	}
785 }
786 
787 void bpf_prog_put(struct bpf_prog *prog)
788 {
789 	__bpf_prog_put(prog, true);
790 }
791 EXPORT_SYMBOL_GPL(bpf_prog_put);
792 
793 static int bpf_prog_release(struct inode *inode, struct file *filp)
794 {
795 	struct bpf_prog *prog = filp->private_data;
796 
797 	bpf_prog_put(prog);
798 	return 0;
799 }
800 
801 #ifdef CONFIG_PROC_FS
802 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
803 {
804 	const struct bpf_prog *prog = filp->private_data;
805 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
806 
807 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
808 	seq_printf(m,
809 		   "prog_type:\t%u\n"
810 		   "prog_jited:\t%u\n"
811 		   "prog_tag:\t%s\n"
812 		   "memlock:\t%llu\n",
813 		   prog->type,
814 		   prog->jited,
815 		   prog_tag,
816 		   prog->pages * 1ULL << PAGE_SHIFT);
817 }
818 #endif
819 
820 static const struct file_operations bpf_prog_fops = {
821 #ifdef CONFIG_PROC_FS
822 	.show_fdinfo	= bpf_prog_show_fdinfo,
823 #endif
824 	.release	= bpf_prog_release,
825 };
826 
827 int bpf_prog_new_fd(struct bpf_prog *prog)
828 {
829 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
830 				O_RDWR | O_CLOEXEC);
831 }
832 
833 static struct bpf_prog *____bpf_prog_get(struct fd f)
834 {
835 	if (!f.file)
836 		return ERR_PTR(-EBADF);
837 	if (f.file->f_op != &bpf_prog_fops) {
838 		fdput(f);
839 		return ERR_PTR(-EINVAL);
840 	}
841 
842 	return f.file->private_data;
843 }
844 
845 struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
846 {
847 	if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
848 		atomic_sub(i, &prog->aux->refcnt);
849 		return ERR_PTR(-EBUSY);
850 	}
851 	return prog;
852 }
853 EXPORT_SYMBOL_GPL(bpf_prog_add);
854 
855 void bpf_prog_sub(struct bpf_prog *prog, int i)
856 {
857 	/* Only to be used for undoing previous bpf_prog_add() in some
858 	 * error path. We still know that another entity in our call
859 	 * path holds a reference to the program, thus atomic_sub() can
860 	 * be safely used in such cases!
861 	 */
862 	WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
863 }
864 EXPORT_SYMBOL_GPL(bpf_prog_sub);
865 
866 struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
867 {
868 	return bpf_prog_add(prog, 1);
869 }
870 EXPORT_SYMBOL_GPL(bpf_prog_inc);
871 
872 /* prog_idr_lock should have been held */
873 static struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
874 {
875 	int refold;
876 
877 	refold = __atomic_add_unless(&prog->aux->refcnt, 1, 0);
878 
879 	if (refold >= BPF_MAX_REFCNT) {
880 		__bpf_prog_put(prog, false);
881 		return ERR_PTR(-EBUSY);
882 	}
883 
884 	if (!refold)
885 		return ERR_PTR(-ENOENT);
886 
887 	return prog;
888 }
889 
890 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type)
891 {
892 	struct fd f = fdget(ufd);
893 	struct bpf_prog *prog;
894 
895 	prog = ____bpf_prog_get(f);
896 	if (IS_ERR(prog))
897 		return prog;
898 	if (type && prog->type != *type) {
899 		prog = ERR_PTR(-EINVAL);
900 		goto out;
901 	}
902 
903 	prog = bpf_prog_inc(prog);
904 out:
905 	fdput(f);
906 	return prog;
907 }
908 
909 struct bpf_prog *bpf_prog_get(u32 ufd)
910 {
911 	return __bpf_prog_get(ufd, NULL);
912 }
913 
914 struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type)
915 {
916 	struct bpf_prog *prog = __bpf_prog_get(ufd, &type);
917 
918 	if (!IS_ERR(prog))
919 		trace_bpf_prog_get_type(prog);
920 	return prog;
921 }
922 EXPORT_SYMBOL_GPL(bpf_prog_get_type);
923 
924 /* last field in 'union bpf_attr' used by this command */
925 #define	BPF_PROG_LOAD_LAST_FIELD prog_flags
926 
927 static int bpf_prog_load(union bpf_attr *attr)
928 {
929 	enum bpf_prog_type type = attr->prog_type;
930 	struct bpf_prog *prog;
931 	int err;
932 	char license[128];
933 	bool is_gpl;
934 
935 	if (CHECK_ATTR(BPF_PROG_LOAD))
936 		return -EINVAL;
937 
938 	if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
939 		return -EINVAL;
940 
941 	/* copy eBPF program license from user space */
942 	if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
943 			      sizeof(license) - 1) < 0)
944 		return -EFAULT;
945 	license[sizeof(license) - 1] = 0;
946 
947 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
948 	is_gpl = license_is_gpl_compatible(license);
949 
950 	if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
951 		return -E2BIG;
952 
953 	if (type == BPF_PROG_TYPE_KPROBE &&
954 	    attr->kern_version != LINUX_VERSION_CODE)
955 		return -EINVAL;
956 
957 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
958 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
959 	    !capable(CAP_SYS_ADMIN))
960 		return -EPERM;
961 
962 	/* plain bpf_prog allocation */
963 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
964 	if (!prog)
965 		return -ENOMEM;
966 
967 	err = bpf_prog_charge_memlock(prog);
968 	if (err)
969 		goto free_prog_nouncharge;
970 
971 	prog->len = attr->insn_cnt;
972 
973 	err = -EFAULT;
974 	if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
975 			   bpf_prog_insn_size(prog)) != 0)
976 		goto free_prog;
977 
978 	prog->orig_prog = NULL;
979 	prog->jited = 0;
980 
981 	atomic_set(&prog->aux->refcnt, 1);
982 	prog->gpl_compatible = is_gpl ? 1 : 0;
983 
984 	/* find program type: socket_filter vs tracing_filter */
985 	err = find_prog_type(type, prog);
986 	if (err < 0)
987 		goto free_prog;
988 
989 	/* run eBPF verifier */
990 	err = bpf_check(&prog, attr);
991 	if (err < 0)
992 		goto free_used_maps;
993 
994 	/* eBPF program is ready to be JITed */
995 	prog = bpf_prog_select_runtime(prog, &err);
996 	if (err < 0)
997 		goto free_used_maps;
998 
999 	err = bpf_prog_alloc_id(prog);
1000 	if (err)
1001 		goto free_used_maps;
1002 
1003 	err = bpf_prog_new_fd(prog);
1004 	if (err < 0) {
1005 		/* failed to allocate fd.
1006 		 * bpf_prog_put() is needed because the above
1007 		 * bpf_prog_alloc_id() has published the prog
1008 		 * to the userspace and the userspace may
1009 		 * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
1010 		 */
1011 		bpf_prog_put(prog);
1012 		return err;
1013 	}
1014 
1015 	bpf_prog_kallsyms_add(prog);
1016 	trace_bpf_prog_load(prog, err);
1017 	return err;
1018 
1019 free_used_maps:
1020 	free_used_maps(prog->aux);
1021 free_prog:
1022 	bpf_prog_uncharge_memlock(prog);
1023 free_prog_nouncharge:
1024 	bpf_prog_free(prog);
1025 	return err;
1026 }
1027 
1028 #define BPF_OBJ_LAST_FIELD bpf_fd
1029 
1030 static int bpf_obj_pin(const union bpf_attr *attr)
1031 {
1032 	if (CHECK_ATTR(BPF_OBJ))
1033 		return -EINVAL;
1034 
1035 	return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
1036 }
1037 
1038 static int bpf_obj_get(const union bpf_attr *attr)
1039 {
1040 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0)
1041 		return -EINVAL;
1042 
1043 	return bpf_obj_get_user(u64_to_user_ptr(attr->pathname));
1044 }
1045 
1046 #ifdef CONFIG_CGROUP_BPF
1047 
1048 #define BPF_PROG_ATTACH_LAST_FIELD attach_flags
1049 
1050 static int bpf_prog_attach(const union bpf_attr *attr)
1051 {
1052 	enum bpf_prog_type ptype;
1053 	struct bpf_prog *prog;
1054 	struct cgroup *cgrp;
1055 	int ret;
1056 
1057 	if (!capable(CAP_NET_ADMIN))
1058 		return -EPERM;
1059 
1060 	if (CHECK_ATTR(BPF_PROG_ATTACH))
1061 		return -EINVAL;
1062 
1063 	if (attr->attach_flags & ~BPF_F_ALLOW_OVERRIDE)
1064 		return -EINVAL;
1065 
1066 	switch (attr->attach_type) {
1067 	case BPF_CGROUP_INET_INGRESS:
1068 	case BPF_CGROUP_INET_EGRESS:
1069 		ptype = BPF_PROG_TYPE_CGROUP_SKB;
1070 		break;
1071 	case BPF_CGROUP_INET_SOCK_CREATE:
1072 		ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1073 		break;
1074 	case BPF_CGROUP_SOCK_OPS:
1075 		ptype = BPF_PROG_TYPE_SOCK_OPS;
1076 		break;
1077 	default:
1078 		return -EINVAL;
1079 	}
1080 
1081 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1082 	if (IS_ERR(prog))
1083 		return PTR_ERR(prog);
1084 
1085 	cgrp = cgroup_get_from_fd(attr->target_fd);
1086 	if (IS_ERR(cgrp)) {
1087 		bpf_prog_put(prog);
1088 		return PTR_ERR(cgrp);
1089 	}
1090 
1091 	ret = cgroup_bpf_update(cgrp, prog, attr->attach_type,
1092 				attr->attach_flags & BPF_F_ALLOW_OVERRIDE);
1093 	if (ret)
1094 		bpf_prog_put(prog);
1095 	cgroup_put(cgrp);
1096 
1097 	return ret;
1098 }
1099 
1100 #define BPF_PROG_DETACH_LAST_FIELD attach_type
1101 
1102 static int bpf_prog_detach(const union bpf_attr *attr)
1103 {
1104 	struct cgroup *cgrp;
1105 	int ret;
1106 
1107 	if (!capable(CAP_NET_ADMIN))
1108 		return -EPERM;
1109 
1110 	if (CHECK_ATTR(BPF_PROG_DETACH))
1111 		return -EINVAL;
1112 
1113 	switch (attr->attach_type) {
1114 	case BPF_CGROUP_INET_INGRESS:
1115 	case BPF_CGROUP_INET_EGRESS:
1116 	case BPF_CGROUP_INET_SOCK_CREATE:
1117 	case BPF_CGROUP_SOCK_OPS:
1118 		cgrp = cgroup_get_from_fd(attr->target_fd);
1119 		if (IS_ERR(cgrp))
1120 			return PTR_ERR(cgrp);
1121 
1122 		ret = cgroup_bpf_update(cgrp, NULL, attr->attach_type, false);
1123 		cgroup_put(cgrp);
1124 		break;
1125 
1126 	default:
1127 		return -EINVAL;
1128 	}
1129 
1130 	return ret;
1131 }
1132 
1133 #endif /* CONFIG_CGROUP_BPF */
1134 
1135 #define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
1136 
1137 static int bpf_prog_test_run(const union bpf_attr *attr,
1138 			     union bpf_attr __user *uattr)
1139 {
1140 	struct bpf_prog *prog;
1141 	int ret = -ENOTSUPP;
1142 
1143 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
1144 		return -EINVAL;
1145 
1146 	prog = bpf_prog_get(attr->test.prog_fd);
1147 	if (IS_ERR(prog))
1148 		return PTR_ERR(prog);
1149 
1150 	if (prog->aux->ops->test_run)
1151 		ret = prog->aux->ops->test_run(prog, attr, uattr);
1152 
1153 	bpf_prog_put(prog);
1154 	return ret;
1155 }
1156 
1157 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
1158 
1159 static int bpf_obj_get_next_id(const union bpf_attr *attr,
1160 			       union bpf_attr __user *uattr,
1161 			       struct idr *idr,
1162 			       spinlock_t *lock)
1163 {
1164 	u32 next_id = attr->start_id;
1165 	int err = 0;
1166 
1167 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
1168 		return -EINVAL;
1169 
1170 	if (!capable(CAP_SYS_ADMIN))
1171 		return -EPERM;
1172 
1173 	next_id++;
1174 	spin_lock_bh(lock);
1175 	if (!idr_get_next(idr, &next_id))
1176 		err = -ENOENT;
1177 	spin_unlock_bh(lock);
1178 
1179 	if (!err)
1180 		err = put_user(next_id, &uattr->next_id);
1181 
1182 	return err;
1183 }
1184 
1185 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
1186 
1187 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
1188 {
1189 	struct bpf_prog *prog;
1190 	u32 id = attr->prog_id;
1191 	int fd;
1192 
1193 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
1194 		return -EINVAL;
1195 
1196 	if (!capable(CAP_SYS_ADMIN))
1197 		return -EPERM;
1198 
1199 	spin_lock_bh(&prog_idr_lock);
1200 	prog = idr_find(&prog_idr, id);
1201 	if (prog)
1202 		prog = bpf_prog_inc_not_zero(prog);
1203 	else
1204 		prog = ERR_PTR(-ENOENT);
1205 	spin_unlock_bh(&prog_idr_lock);
1206 
1207 	if (IS_ERR(prog))
1208 		return PTR_ERR(prog);
1209 
1210 	fd = bpf_prog_new_fd(prog);
1211 	if (fd < 0)
1212 		bpf_prog_put(prog);
1213 
1214 	return fd;
1215 }
1216 
1217 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD map_id
1218 
1219 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
1220 {
1221 	struct bpf_map *map;
1222 	u32 id = attr->map_id;
1223 	int fd;
1224 
1225 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID))
1226 		return -EINVAL;
1227 
1228 	if (!capable(CAP_SYS_ADMIN))
1229 		return -EPERM;
1230 
1231 	spin_lock_bh(&map_idr_lock);
1232 	map = idr_find(&map_idr, id);
1233 	if (map)
1234 		map = bpf_map_inc_not_zero(map, true);
1235 	else
1236 		map = ERR_PTR(-ENOENT);
1237 	spin_unlock_bh(&map_idr_lock);
1238 
1239 	if (IS_ERR(map))
1240 		return PTR_ERR(map);
1241 
1242 	fd = bpf_map_new_fd(map);
1243 	if (fd < 0)
1244 		bpf_map_put(map);
1245 
1246 	return fd;
1247 }
1248 
1249 static int check_uarg_tail_zero(void __user *uaddr,
1250 				size_t expected_size,
1251 				size_t actual_size)
1252 {
1253 	unsigned char __user *addr;
1254 	unsigned char __user *end;
1255 	unsigned char val;
1256 	int err;
1257 
1258 	if (actual_size <= expected_size)
1259 		return 0;
1260 
1261 	addr = uaddr + expected_size;
1262 	end  = uaddr + actual_size;
1263 
1264 	for (; addr < end; addr++) {
1265 		err = get_user(val, addr);
1266 		if (err)
1267 			return err;
1268 		if (val)
1269 			return -E2BIG;
1270 	}
1271 
1272 	return 0;
1273 }
1274 
1275 static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
1276 				   const union bpf_attr *attr,
1277 				   union bpf_attr __user *uattr)
1278 {
1279 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1280 	struct bpf_prog_info info = {};
1281 	u32 info_len = attr->info.info_len;
1282 	char __user *uinsns;
1283 	u32 ulen;
1284 	int err;
1285 
1286 	err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1287 	if (err)
1288 		return err;
1289 	info_len = min_t(u32, sizeof(info), info_len);
1290 
1291 	if (copy_from_user(&info, uinfo, info_len))
1292 		return -EFAULT;
1293 
1294 	info.type = prog->type;
1295 	info.id = prog->aux->id;
1296 
1297 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
1298 
1299 	if (!capable(CAP_SYS_ADMIN)) {
1300 		info.jited_prog_len = 0;
1301 		info.xlated_prog_len = 0;
1302 		goto done;
1303 	}
1304 
1305 	ulen = info.jited_prog_len;
1306 	info.jited_prog_len = prog->jited_len;
1307 	if (info.jited_prog_len && ulen) {
1308 		uinsns = u64_to_user_ptr(info.jited_prog_insns);
1309 		ulen = min_t(u32, info.jited_prog_len, ulen);
1310 		if (copy_to_user(uinsns, prog->bpf_func, ulen))
1311 			return -EFAULT;
1312 	}
1313 
1314 	ulen = info.xlated_prog_len;
1315 	info.xlated_prog_len = bpf_prog_insn_size(prog);
1316 	if (info.xlated_prog_len && ulen) {
1317 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
1318 		ulen = min_t(u32, info.xlated_prog_len, ulen);
1319 		if (copy_to_user(uinsns, prog->insnsi, ulen))
1320 			return -EFAULT;
1321 	}
1322 
1323 done:
1324 	if (copy_to_user(uinfo, &info, info_len) ||
1325 	    put_user(info_len, &uattr->info.info_len))
1326 		return -EFAULT;
1327 
1328 	return 0;
1329 }
1330 
1331 static int bpf_map_get_info_by_fd(struct bpf_map *map,
1332 				  const union bpf_attr *attr,
1333 				  union bpf_attr __user *uattr)
1334 {
1335 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1336 	struct bpf_map_info info = {};
1337 	u32 info_len = attr->info.info_len;
1338 	int err;
1339 
1340 	err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1341 	if (err)
1342 		return err;
1343 	info_len = min_t(u32, sizeof(info), info_len);
1344 
1345 	info.type = map->map_type;
1346 	info.id = map->id;
1347 	info.key_size = map->key_size;
1348 	info.value_size = map->value_size;
1349 	info.max_entries = map->max_entries;
1350 	info.map_flags = map->map_flags;
1351 
1352 	if (copy_to_user(uinfo, &info, info_len) ||
1353 	    put_user(info_len, &uattr->info.info_len))
1354 		return -EFAULT;
1355 
1356 	return 0;
1357 }
1358 
1359 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
1360 
1361 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
1362 				  union bpf_attr __user *uattr)
1363 {
1364 	int ufd = attr->info.bpf_fd;
1365 	struct fd f;
1366 	int err;
1367 
1368 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
1369 		return -EINVAL;
1370 
1371 	f = fdget(ufd);
1372 	if (!f.file)
1373 		return -EBADFD;
1374 
1375 	if (f.file->f_op == &bpf_prog_fops)
1376 		err = bpf_prog_get_info_by_fd(f.file->private_data, attr,
1377 					      uattr);
1378 	else if (f.file->f_op == &bpf_map_fops)
1379 		err = bpf_map_get_info_by_fd(f.file->private_data, attr,
1380 					     uattr);
1381 	else
1382 		err = -EINVAL;
1383 
1384 	fdput(f);
1385 	return err;
1386 }
1387 
1388 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
1389 {
1390 	union bpf_attr attr = {};
1391 	int err;
1392 
1393 	if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled)
1394 		return -EPERM;
1395 
1396 	if (!access_ok(VERIFY_READ, uattr, 1))
1397 		return -EFAULT;
1398 
1399 	if (size > PAGE_SIZE)	/* silly large */
1400 		return -E2BIG;
1401 
1402 	/* If we're handed a bigger struct than we know of,
1403 	 * ensure all the unknown bits are 0 - i.e. new
1404 	 * user-space does not rely on any kernel feature
1405 	 * extensions we dont know about yet.
1406 	 */
1407 	err = check_uarg_tail_zero(uattr, sizeof(attr), size);
1408 	if (err)
1409 		return err;
1410 	size = min_t(u32, size, sizeof(attr));
1411 
1412 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
1413 	if (copy_from_user(&attr, uattr, size) != 0)
1414 		return -EFAULT;
1415 
1416 	switch (cmd) {
1417 	case BPF_MAP_CREATE:
1418 		err = map_create(&attr);
1419 		break;
1420 	case BPF_MAP_LOOKUP_ELEM:
1421 		err = map_lookup_elem(&attr);
1422 		break;
1423 	case BPF_MAP_UPDATE_ELEM:
1424 		err = map_update_elem(&attr);
1425 		break;
1426 	case BPF_MAP_DELETE_ELEM:
1427 		err = map_delete_elem(&attr);
1428 		break;
1429 	case BPF_MAP_GET_NEXT_KEY:
1430 		err = map_get_next_key(&attr);
1431 		break;
1432 	case BPF_PROG_LOAD:
1433 		err = bpf_prog_load(&attr);
1434 		break;
1435 	case BPF_OBJ_PIN:
1436 		err = bpf_obj_pin(&attr);
1437 		break;
1438 	case BPF_OBJ_GET:
1439 		err = bpf_obj_get(&attr);
1440 		break;
1441 #ifdef CONFIG_CGROUP_BPF
1442 	case BPF_PROG_ATTACH:
1443 		err = bpf_prog_attach(&attr);
1444 		break;
1445 	case BPF_PROG_DETACH:
1446 		err = bpf_prog_detach(&attr);
1447 		break;
1448 #endif
1449 	case BPF_PROG_TEST_RUN:
1450 		err = bpf_prog_test_run(&attr, uattr);
1451 		break;
1452 	case BPF_PROG_GET_NEXT_ID:
1453 		err = bpf_obj_get_next_id(&attr, uattr,
1454 					  &prog_idr, &prog_idr_lock);
1455 		break;
1456 	case BPF_MAP_GET_NEXT_ID:
1457 		err = bpf_obj_get_next_id(&attr, uattr,
1458 					  &map_idr, &map_idr_lock);
1459 		break;
1460 	case BPF_PROG_GET_FD_BY_ID:
1461 		err = bpf_prog_get_fd_by_id(&attr);
1462 		break;
1463 	case BPF_MAP_GET_FD_BY_ID:
1464 		err = bpf_map_get_fd_by_id(&attr);
1465 		break;
1466 	case BPF_OBJ_GET_INFO_BY_FD:
1467 		err = bpf_obj_get_info_by_fd(&attr, uattr);
1468 		break;
1469 	default:
1470 		err = -EINVAL;
1471 		break;
1472 	}
1473 
1474 	return err;
1475 }
1476