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Linux 4.15.6
[linux/fpc-iii.git] / kernel / bpf / syscall.c
blob5cb783fc8224b3c5acb65bae4d79c0ec74a71c7a
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 #include <linux/cred.h>
27 #include <linux/timekeeping.h>
28 #include <linux/ctype.h>
29
30 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
31 (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
32 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
33 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
34 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
35 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map))
36
37 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY)
38
39 DEFINE_PER_CPU(int, bpf_prog_active);
40 static DEFINE_IDR(prog_idr);
41 static DEFINE_SPINLOCK(prog_idr_lock);
42 static DEFINE_IDR(map_idr);
43 static DEFINE_SPINLOCK(map_idr_lock);
44
45 int sysctl_unprivileged_bpf_disabled __read_mostly;
46
47 static const struct bpf_map_ops * const bpf_map_types[] = {
48 #define BPF_PROG_TYPE(_id, _ops)
49 #define BPF_MAP_TYPE(_id, _ops) \
50 [_id] = &_ops,
51 #include <linux/bpf_types.h>
52 #undef BPF_PROG_TYPE
53 #undef BPF_MAP_TYPE
54 };
55
56 /*
57 * If we're handed a bigger struct than we know of, ensure all the unknown bits
58 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
59 * we don't know about yet.
60 *
61 * There is a ToCToU between this function call and the following
62 * copy_from_user() call. However, this is not a concern since this function is
63 * meant to be a future-proofing of bits.
64 */
65 static int check_uarg_tail_zero(void __user *uaddr,
66 size_t expected_size,
67 size_t actual_size)
68 {
69 unsigned char __user *addr;
70 unsigned char __user *end;
71 unsigned char val;
72 int err;
73
74 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
75 return -E2BIG;
76
77 if (unlikely(!access_ok(VERIFY_READ, uaddr, actual_size)))
78 return -EFAULT;
79
80 if (actual_size <= expected_size)
81 return 0;
82
83 addr = uaddr + expected_size;
84 end = uaddr + actual_size;
85
86 for (; addr < end; addr++) {
87 err = get_user(val, addr);
88 if (err)
89 return err;
90 if (val)
91 return -E2BIG;
92 }
93
94 return 0;
95 }
96
97 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
98 {
99 struct bpf_map *map;
100
101 if (attr->map_type >= ARRAY_SIZE(bpf_map_types) ||
102 !bpf_map_types[attr->map_type])
103 return ERR_PTR(-EINVAL);
104
105 map = bpf_map_types[attr->map_type]->map_alloc(attr);
106 if (IS_ERR(map))
107 return map;
108 map->ops = bpf_map_types[attr->map_type];
109 map->map_type = attr->map_type;
110 return map;
111 }
112
113 void *bpf_map_area_alloc(size_t size, int numa_node)
114 {
115 /* We definitely need __GFP_NORETRY, so OOM killer doesn't
116 * trigger under memory pressure as we really just want to
117 * fail instead.
118 */
119 const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
120 void *area;
121
122 if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
123 area = kmalloc_node(size, GFP_USER | flags, numa_node);
124 if (area != NULL)
125 return area;
126 }
127
128 return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
129 __builtin_return_address(0));
130 }
131
132 void bpf_map_area_free(void *area)
133 {
134 kvfree(area);
135 }
136
137 int bpf_map_precharge_memlock(u32 pages)
138 {
139 struct user_struct *user = get_current_user();
140 unsigned long memlock_limit, cur;
141
142 memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
143 cur = atomic_long_read(&user->locked_vm);
144 free_uid(user);
145 if (cur + pages > memlock_limit)
146 return -EPERM;
147 return 0;
148 }
149
150 static int bpf_map_charge_memlock(struct bpf_map *map)
151 {
152 struct user_struct *user = get_current_user();
153 unsigned long memlock_limit;
154
155 memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
156
157 atomic_long_add(map->pages, &user->locked_vm);
158
159 if (atomic_long_read(&user->locked_vm) > memlock_limit) {
160 atomic_long_sub(map->pages, &user->locked_vm);
161 free_uid(user);
162 return -EPERM;
163 }
164 map->user = user;
165 return 0;
166 }
167
168 static void bpf_map_uncharge_memlock(struct bpf_map *map)
169 {
170 struct user_struct *user = map->user;
171
172 atomic_long_sub(map->pages, &user->locked_vm);
173 free_uid(user);
174 }
175
176 static int bpf_map_alloc_id(struct bpf_map *map)
177 {
178 int id;
179
180 spin_lock_bh(&map_idr_lock);
181 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
182 if (id > 0)
183 map->id = id;
184 spin_unlock_bh(&map_idr_lock);
185
186 if (WARN_ON_ONCE(!id))
187 return -ENOSPC;
188
189 return id > 0 ? 0 : id;
190 }
191
192 static void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
193 {
194 unsigned long flags;
195
196 if (do_idr_lock)
197 spin_lock_irqsave(&map_idr_lock, flags);
198 else
199 __acquire(&map_idr_lock);
200
201 idr_remove(&map_idr, map->id);
202
203 if (do_idr_lock)
204 spin_unlock_irqrestore(&map_idr_lock, flags);
205 else
206 __release(&map_idr_lock);
207 }
208
209 /* called from workqueue */
210 static void bpf_map_free_deferred(struct work_struct *work)
211 {
212 struct bpf_map *map = container_of(work, struct bpf_map, work);
213
214 bpf_map_uncharge_memlock(map);
215 security_bpf_map_free(map);
216 /* implementation dependent freeing */
217 map->ops->map_free(map);
218 }
219
220 static void bpf_map_put_uref(struct bpf_map *map)
221 {
222 if (atomic_dec_and_test(&map->usercnt)) {
223 if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
224 bpf_fd_array_map_clear(map);
225 }
226 }
227
228 /* decrement map refcnt and schedule it for freeing via workqueue
229 * (unrelying map implementation ops->map_free() might sleep)
230 */
231 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
232 {
233 if (atomic_dec_and_test(&map->refcnt)) {
234 /* bpf_map_free_id() must be called first */
235 bpf_map_free_id(map, do_idr_lock);
236 INIT_WORK(&map->work, bpf_map_free_deferred);
237 schedule_work(&map->work);
238 }
239 }
240
241 void bpf_map_put(struct bpf_map *map)
242 {
243 __bpf_map_put(map, true);
244 }
245
246 void bpf_map_put_with_uref(struct bpf_map *map)
247 {
248 bpf_map_put_uref(map);
249 bpf_map_put(map);
250 }
251
252 static int bpf_map_release(struct inode *inode, struct file *filp)
253 {
254 struct bpf_map *map = filp->private_data;
255
256 if (map->ops->map_release)
257 map->ops->map_release(map, filp);
258
259 bpf_map_put_with_uref(map);
260 return 0;
261 }
262
263 #ifdef CONFIG_PROC_FS
264 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
265 {
266 const struct bpf_map *map = filp->private_data;
267 const struct bpf_array *array;
268 u32 owner_prog_type = 0;
269 u32 owner_jited = 0;
270
271 if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
272 array = container_of(map, struct bpf_array, map);
273 owner_prog_type = array->owner_prog_type;
274 owner_jited = array->owner_jited;
275 }
276
277 seq_printf(m,
278 "map_type:\t%u\n"
279 "key_size:\t%u\n"
280 "value_size:\t%u\n"
281 "max_entries:\t%u\n"
282 "map_flags:\t%#x\n"
283 "memlock:\t%llu\n",
284 map->map_type,
285 map->key_size,
286 map->value_size,
287 map->max_entries,
288 map->map_flags,
289 map->pages * 1ULL << PAGE_SHIFT);
290
291 if (owner_prog_type) {
292 seq_printf(m, "owner_prog_type:\t%u\n",
293 owner_prog_type);
294 seq_printf(m, "owner_jited:\t%u\n",
295 owner_jited);
296 }
297 }
298 #endif
299
300 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
301 loff_t *ppos)
302 {
303 /* We need this handler such that alloc_file() enables
304 * f_mode with FMODE_CAN_READ.
305 */
306 return -EINVAL;
307 }
308
309 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
310 size_t siz, loff_t *ppos)
311 {
312 /* We need this handler such that alloc_file() enables
313 * f_mode with FMODE_CAN_WRITE.
314 */
315 return -EINVAL;
316 }
317
318 const struct file_operations bpf_map_fops = {
319 #ifdef CONFIG_PROC_FS
320 .show_fdinfo = bpf_map_show_fdinfo,
321 #endif
322 .release = bpf_map_release,
323 .read = bpf_dummy_read,
324 .write = bpf_dummy_write,
325 };
326
327 int bpf_map_new_fd(struct bpf_map *map, int flags)
328 {
329 int ret;
330
331 ret = security_bpf_map(map, OPEN_FMODE(flags));
332 if (ret < 0)
333 return ret;
334
335 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
336 flags | O_CLOEXEC);
337 }
338
339 int bpf_get_file_flag(int flags)
340 {
341 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
342 return -EINVAL;
343 if (flags & BPF_F_RDONLY)
344 return O_RDONLY;
345 if (flags & BPF_F_WRONLY)
346 return O_WRONLY;
347 return O_RDWR;
348 }
349
350 /* helper macro to check that unused fields 'union bpf_attr' are zero */
351 #define CHECK_ATTR(CMD) \
352 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
353 sizeof(attr->CMD##_LAST_FIELD), 0, \
354 sizeof(*attr) - \
355 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
356 sizeof(attr->CMD##_LAST_FIELD)) != NULL
357
358 /* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes.
359 * Return 0 on success and < 0 on error.
360 */
361 static int bpf_obj_name_cpy(char *dst, const char *src)
362 {
363 const char *end = src + BPF_OBJ_NAME_LEN;
364
365 memset(dst, 0, BPF_OBJ_NAME_LEN);
366
367 /* Copy all isalnum() and '_' char */
368 while (src < end && *src) {
369 if (!isalnum(*src) && *src != '_')
370 return -EINVAL;
371 *dst++ = *src++;
372 }
373
374 /* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */
375 if (src == end)
376 return -EINVAL;
377
378 return 0;
379 }
380
381 #define BPF_MAP_CREATE_LAST_FIELD map_name
382 /* called via syscall */
383 static int map_create(union bpf_attr *attr)
384 {
385 int numa_node = bpf_map_attr_numa_node(attr);
386 struct bpf_map *map;
387 int f_flags;
388 int err;
389
390 err = CHECK_ATTR(BPF_MAP_CREATE);
391 if (err)
392 return -EINVAL;
393
394 f_flags = bpf_get_file_flag(attr->map_flags);
395 if (f_flags < 0)
396 return f_flags;
397
398 if (numa_node != NUMA_NO_NODE &&
399 ((unsigned int)numa_node >= nr_node_ids ||
400 !node_online(numa_node)))
401 return -EINVAL;
402
403 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
404 map = find_and_alloc_map(attr);
405 if (IS_ERR(map))
406 return PTR_ERR(map);
407
408 err = bpf_obj_name_cpy(map->name, attr->map_name);
409 if (err)
410 goto free_map_nouncharge;
411
412 atomic_set(&map->refcnt, 1);
413 atomic_set(&map->usercnt, 1);
414
415 err = security_bpf_map_alloc(map);
416 if (err)
417 goto free_map_nouncharge;
418
419 err = bpf_map_charge_memlock(map);
420 if (err)
421 goto free_map_sec;
422
423 err = bpf_map_alloc_id(map);
424 if (err)
425 goto free_map;
426
427 err = bpf_map_new_fd(map, f_flags);
428 if (err < 0) {
429 /* failed to allocate fd.
430 * bpf_map_put() is needed because the above
431 * bpf_map_alloc_id() has published the map
432 * to the userspace and the userspace may
433 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
434 */
435 bpf_map_put(map);
436 return err;
437 }
438
439 trace_bpf_map_create(map, err);
440 return err;
441
442 free_map:
443 bpf_map_uncharge_memlock(map);
444 free_map_sec:
445 security_bpf_map_free(map);
446 free_map_nouncharge:
447 map->ops->map_free(map);
448 return err;
449 }
450
451 /* if error is returned, fd is released.
452 * On success caller should complete fd access with matching fdput()
453 */
454 struct bpf_map *__bpf_map_get(struct fd f)
455 {
456 if (!f.file)
457 return ERR_PTR(-EBADF);
458 if (f.file->f_op != &bpf_map_fops) {
459 fdput(f);
460 return ERR_PTR(-EINVAL);
461 }
462
463 return f.file->private_data;
464 }
465
466 /* prog's and map's refcnt limit */
467 #define BPF_MAX_REFCNT 32768
468
469 struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
470 {
471 if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
472 atomic_dec(&map->refcnt);
473 return ERR_PTR(-EBUSY);
474 }
475 if (uref)
476 atomic_inc(&map->usercnt);
477 return map;
478 }
479
480 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
481 {
482 struct fd f = fdget(ufd);
483 struct bpf_map *map;
484
485 map = __bpf_map_get(f);
486 if (IS_ERR(map))
487 return map;
488
489 map = bpf_map_inc(map, true);
490 fdput(f);
491
492 return map;
493 }
494
495 /* map_idr_lock should have been held */
496 static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map,
497 bool uref)
498 {
499 int refold;
500
501 refold = __atomic_add_unless(&map->refcnt, 1, 0);
502
503 if (refold >= BPF_MAX_REFCNT) {
504 __bpf_map_put(map, false);
505 return ERR_PTR(-EBUSY);
506 }
507
508 if (!refold)
509 return ERR_PTR(-ENOENT);
510
511 if (uref)
512 atomic_inc(&map->usercnt);
513
514 return map;
515 }
516
517 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
518 {
519 return -ENOTSUPP;
520 }
521
522 /* last field in 'union bpf_attr' used by this command */
523 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
524
525 static int map_lookup_elem(union bpf_attr *attr)
526 {
527 void __user *ukey = u64_to_user_ptr(attr->key);
528 void __user *uvalue = u64_to_user_ptr(attr->value);
529 int ufd = attr->map_fd;
530 struct bpf_map *map;
531 void *key, *value, *ptr;
532 u32 value_size;
533 struct fd f;
534 int err;
535
536 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
537 return -EINVAL;
538
539 f = fdget(ufd);
540 map = __bpf_map_get(f);
541 if (IS_ERR(map))
542 return PTR_ERR(map);
543
544 if (!(f.file->f_mode & FMODE_CAN_READ)) {
545 err = -EPERM;
546 goto err_put;
547 }
548
549 key = memdup_user(ukey, map->key_size);
550 if (IS_ERR(key)) {
551 err = PTR_ERR(key);
552 goto err_put;
553 }
554
555 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
556 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
557 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
558 value_size = round_up(map->value_size, 8) * num_possible_cpus();
559 else if (IS_FD_MAP(map))
560 value_size = sizeof(u32);
561 else
562 value_size = map->value_size;
563
564 err = -ENOMEM;
565 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
566 if (!value)
567 goto free_key;
568
569 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
570 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
571 err = bpf_percpu_hash_copy(map, key, value);
572 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
573 err = bpf_percpu_array_copy(map, key, value);
574 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
575 err = bpf_stackmap_copy(map, key, value);
576 } else if (IS_FD_ARRAY(map)) {
577 err = bpf_fd_array_map_lookup_elem(map, key, value);
578 } else if (IS_FD_HASH(map)) {
579 err = bpf_fd_htab_map_lookup_elem(map, key, value);
580 } else {
581 rcu_read_lock();
582 ptr = map->ops->map_lookup_elem(map, key);
583 if (ptr)
584 memcpy(value, ptr, value_size);
585 rcu_read_unlock();
586 err = ptr ? 0 : -ENOENT;
587 }
588
589 if (err)
590 goto free_value;
591
592 err = -EFAULT;
593 if (copy_to_user(uvalue, value, value_size) != 0)
594 goto free_value;
595
596 trace_bpf_map_lookup_elem(map, ufd, key, value);
597 err = 0;
598
599 free_value:
600 kfree(value);
601 free_key:
602 kfree(key);
603 err_put:
604 fdput(f);
605 return err;
606 }
607
608 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
609
610 static int map_update_elem(union bpf_attr *attr)
611 {
612 void __user *ukey = u64_to_user_ptr(attr->key);
613 void __user *uvalue = u64_to_user_ptr(attr->value);
614 int ufd = attr->map_fd;
615 struct bpf_map *map;
616 void *key, *value;
617 u32 value_size;
618 struct fd f;
619 int err;
620
621 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
622 return -EINVAL;
623
624 f = fdget(ufd);
625 map = __bpf_map_get(f);
626 if (IS_ERR(map))
627 return PTR_ERR(map);
628
629 if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
630 err = -EPERM;
631 goto err_put;
632 }
633
634 key = memdup_user(ukey, map->key_size);
635 if (IS_ERR(key)) {
636 err = PTR_ERR(key);
637 goto err_put;
638 }
639
640 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
641 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
642 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
643 value_size = round_up(map->value_size, 8) * num_possible_cpus();
644 else
645 value_size = map->value_size;
646
647 err = -ENOMEM;
648 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
649 if (!value)
650 goto free_key;
651
652 err = -EFAULT;
653 if (copy_from_user(value, uvalue, value_size) != 0)
654 goto free_value;
655
656 /* Need to create a kthread, thus must support schedule */
657 if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
658 err = map->ops->map_update_elem(map, key, value, attr->flags);
659 goto out;
660 }
661
662 /* must increment bpf_prog_active to avoid kprobe+bpf triggering from
663 * inside bpf map update or delete otherwise deadlocks are possible
664 */
665 preempt_disable();
666 __this_cpu_inc(bpf_prog_active);
667 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
668 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
669 err = bpf_percpu_hash_update(map, key, value, attr->flags);
670 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
671 err = bpf_percpu_array_update(map, key, value, attr->flags);
672 } else if (map->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY ||
673 map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
674 map->map_type == BPF_MAP_TYPE_CGROUP_ARRAY ||
675 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) {
676 rcu_read_lock();
677 err = bpf_fd_array_map_update_elem(map, f.file, key, value,
678 attr->flags);
679 rcu_read_unlock();
680 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
681 rcu_read_lock();
682 err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
683 attr->flags);
684 rcu_read_unlock();
685 } else {
686 rcu_read_lock();
687 err = map->ops->map_update_elem(map, key, value, attr->flags);
688 rcu_read_unlock();
689 }
690 __this_cpu_dec(bpf_prog_active);
691 preempt_enable();
692 out:
693 if (!err)
694 trace_bpf_map_update_elem(map, ufd, key, value);
695 free_value:
696 kfree(value);
697 free_key:
698 kfree(key);
699 err_put:
700 fdput(f);
701 return err;
702 }
703
704 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
705
706 static int map_delete_elem(union bpf_attr *attr)
707 {
708 void __user *ukey = u64_to_user_ptr(attr->key);
709 int ufd = attr->map_fd;
710 struct bpf_map *map;
711 struct fd f;
712 void *key;
713 int err;
714
715 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
716 return -EINVAL;
717
718 f = fdget(ufd);
719 map = __bpf_map_get(f);
720 if (IS_ERR(map))
721 return PTR_ERR(map);
722
723 if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
724 err = -EPERM;
725 goto err_put;
726 }
727
728 key = memdup_user(ukey, map->key_size);
729 if (IS_ERR(key)) {
730 err = PTR_ERR(key);
731 goto err_put;
732 }
733
734 preempt_disable();
735 __this_cpu_inc(bpf_prog_active);
736 rcu_read_lock();
737 err = map->ops->map_delete_elem(map, key);
738 rcu_read_unlock();
739 __this_cpu_dec(bpf_prog_active);
740 preempt_enable();
741
742 if (!err)
743 trace_bpf_map_delete_elem(map, ufd, key);
744 kfree(key);
745 err_put:
746 fdput(f);
747 return err;
748 }
749
750 /* last field in 'union bpf_attr' used by this command */
751 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
752
753 static int map_get_next_key(union bpf_attr *attr)
754 {
755 void __user *ukey = u64_to_user_ptr(attr->key);
756 void __user *unext_key = u64_to_user_ptr(attr->next_key);
757 int ufd = attr->map_fd;
758 struct bpf_map *map;
759 void *key, *next_key;
760 struct fd f;
761 int err;
762
763 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
764 return -EINVAL;
765
766 f = fdget(ufd);
767 map = __bpf_map_get(f);
768 if (IS_ERR(map))
769 return PTR_ERR(map);
770
771 if (!(f.file->f_mode & FMODE_CAN_READ)) {
772 err = -EPERM;
773 goto err_put;
774 }
775
776 if (ukey) {
777 key = memdup_user(ukey, map->key_size);
778 if (IS_ERR(key)) {
779 err = PTR_ERR(key);
780 goto err_put;
781 }
782 } else {
783 key = NULL;
784 }
785
786 err = -ENOMEM;
787 next_key = kmalloc(map->key_size, GFP_USER);
788 if (!next_key)
789 goto free_key;
790
791 rcu_read_lock();
792 err = map->ops->map_get_next_key(map, key, next_key);
793 rcu_read_unlock();
794 if (err)
795 goto free_next_key;
796
797 err = -EFAULT;
798 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
799 goto free_next_key;
800
801 trace_bpf_map_next_key(map, ufd, key, next_key);
802 err = 0;
803
804 free_next_key:
805 kfree(next_key);
806 free_key:
807 kfree(key);
808 err_put:
809 fdput(f);
810 return err;
811 }
812
813 static const struct bpf_prog_ops * const bpf_prog_types[] = {
814 #define BPF_PROG_TYPE(_id, _name) \
815 [_id] = & _name ## _prog_ops,
816 #define BPF_MAP_TYPE(_id, _ops)
817 #include <linux/bpf_types.h>
818 #undef BPF_PROG_TYPE
819 #undef BPF_MAP_TYPE
820 };
821
822 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
823 {
824 if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
825 return -EINVAL;
826
827 if (!bpf_prog_is_dev_bound(prog->aux))
828 prog->aux->ops = bpf_prog_types[type];
829 else
830 prog->aux->ops = &bpf_offload_prog_ops;
831 prog->type = type;
832 return 0;
833 }
834
835 /* drop refcnt on maps used by eBPF program and free auxilary data */
836 static void free_used_maps(struct bpf_prog_aux *aux)
837 {
838 int i;
839
840 for (i = 0; i < aux->used_map_cnt; i++)
841 bpf_map_put(aux->used_maps[i]);
842
843 kfree(aux->used_maps);
844 }
845
846 int __bpf_prog_charge(struct user_struct *user, u32 pages)
847 {
848 unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
849 unsigned long user_bufs;
850
851 if (user) {
852 user_bufs = atomic_long_add_return(pages, &user->locked_vm);
853 if (user_bufs > memlock_limit) {
854 atomic_long_sub(pages, &user->locked_vm);
855 return -EPERM;
856 }
857 }
858
859 return 0;
860 }
861
862 void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
863 {
864 if (user)
865 atomic_long_sub(pages, &user->locked_vm);
866 }
867
868 static int bpf_prog_charge_memlock(struct bpf_prog *prog)
869 {
870 struct user_struct *user = get_current_user();
871 int ret;
872
873 ret = __bpf_prog_charge(user, prog->pages);
874 if (ret) {
875 free_uid(user);
876 return ret;
877 }
878
879 prog->aux->user = user;
880 return 0;
881 }
882
883 static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
884 {
885 struct user_struct *user = prog->aux->user;
886
887 __bpf_prog_uncharge(user, prog->pages);
888 free_uid(user);
889 }
890
891 static int bpf_prog_alloc_id(struct bpf_prog *prog)
892 {
893 int id;
894
895 spin_lock_bh(&prog_idr_lock);
896 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
897 if (id > 0)
898 prog->aux->id = id;
899 spin_unlock_bh(&prog_idr_lock);
900
901 /* id is in [1, INT_MAX) */
902 if (WARN_ON_ONCE(!id))
903 return -ENOSPC;
904
905 return id > 0 ? 0 : id;
906 }
907
908 static void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
909 {
910 /* cBPF to eBPF migrations are currently not in the idr store. */
911 if (!prog->aux->id)
912 return;
913
914 if (do_idr_lock)
915 spin_lock_bh(&prog_idr_lock);
916 else
917 __acquire(&prog_idr_lock);
918
919 idr_remove(&prog_idr, prog->aux->id);
920
921 if (do_idr_lock)
922 spin_unlock_bh(&prog_idr_lock);
923 else
924 __release(&prog_idr_lock);
925 }
926
927 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
928 {
929 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
930
931 free_used_maps(aux);
932 bpf_prog_uncharge_memlock(aux->prog);
933 security_bpf_prog_free(aux);
934 bpf_prog_free(aux->prog);
935 }
936
937 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
938 {
939 if (atomic_dec_and_test(&prog->aux->refcnt)) {
940 trace_bpf_prog_put_rcu(prog);
941 /* bpf_prog_free_id() must be called first */
942 bpf_prog_free_id(prog, do_idr_lock);
943 bpf_prog_kallsyms_del(prog);
944 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
945 }
946 }
947
948 void bpf_prog_put(struct bpf_prog *prog)
949 {
950 __bpf_prog_put(prog, true);
951 }
952 EXPORT_SYMBOL_GPL(bpf_prog_put);
953
954 static int bpf_prog_release(struct inode *inode, struct file *filp)
955 {
956 struct bpf_prog *prog = filp->private_data;
957
958 bpf_prog_put(prog);
959 return 0;
960 }
961
962 #ifdef CONFIG_PROC_FS
963 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
964 {
965 const struct bpf_prog *prog = filp->private_data;
966 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
967
968 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
969 seq_printf(m,
970 "prog_type:\t%u\n"
971 "prog_jited:\t%u\n"
972 "prog_tag:\t%s\n"
973 "memlock:\t%llu\n",
974 prog->type,
975 prog->jited,
976 prog_tag,
977 prog->pages * 1ULL << PAGE_SHIFT);
978 }
979 #endif
980
981 const struct file_operations bpf_prog_fops = {
982 #ifdef CONFIG_PROC_FS
983 .show_fdinfo = bpf_prog_show_fdinfo,
984 #endif
985 .release = bpf_prog_release,
986 .read = bpf_dummy_read,
987 .write = bpf_dummy_write,
988 };
989
990 int bpf_prog_new_fd(struct bpf_prog *prog)
991 {
992 int ret;
993
994 ret = security_bpf_prog(prog);
995 if (ret < 0)
996 return ret;
997
998 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
999 O_RDWR | O_CLOEXEC);
1000 }
1001
1002 static struct bpf_prog *____bpf_prog_get(struct fd f)
1003 {
1004 if (!f.file)
1005 return ERR_PTR(-EBADF);
1006 if (f.file->f_op != &bpf_prog_fops) {
1007 fdput(f);
1008 return ERR_PTR(-EINVAL);
1009 }
1010
1011 return f.file->private_data;
1012 }
1013
1014 struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
1015 {
1016 if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
1017 atomic_sub(i, &prog->aux->refcnt);
1018 return ERR_PTR(-EBUSY);
1019 }
1020 return prog;
1021 }
1022 EXPORT_SYMBOL_GPL(bpf_prog_add);
1023
1024 void bpf_prog_sub(struct bpf_prog *prog, int i)
1025 {
1026 /* Only to be used for undoing previous bpf_prog_add() in some
1027 * error path. We still know that another entity in our call
1028 * path holds a reference to the program, thus atomic_sub() can
1029 * be safely used in such cases!
1030 */
1031 WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
1032 }
1033 EXPORT_SYMBOL_GPL(bpf_prog_sub);
1034
1035 struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
1036 {
1037 return bpf_prog_add(prog, 1);
1038 }
1039 EXPORT_SYMBOL_GPL(bpf_prog_inc);
1040
1041 /* prog_idr_lock should have been held */
1042 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
1043 {
1044 int refold;
1045
1046 refold = __atomic_add_unless(&prog->aux->refcnt, 1, 0);
1047
1048 if (refold >= BPF_MAX_REFCNT) {
1049 __bpf_prog_put(prog, false);
1050 return ERR_PTR(-EBUSY);
1051 }
1052
1053 if (!refold)
1054 return ERR_PTR(-ENOENT);
1055
1056 return prog;
1057 }
1058 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
1059
1060 bool bpf_prog_get_ok(struct bpf_prog *prog,
1061 enum bpf_prog_type *attach_type, bool attach_drv)
1062 {
1063 /* not an attachment, just a refcount inc, always allow */
1064 if (!attach_type)
1065 return true;
1066
1067 if (prog->type != *attach_type)
1068 return false;
1069 if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
1070 return false;
1071
1072 return true;
1073 }
1074
1075 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
1076 bool attach_drv)
1077 {
1078 struct fd f = fdget(ufd);
1079 struct bpf_prog *prog;
1080
1081 prog = ____bpf_prog_get(f);
1082 if (IS_ERR(prog))
1083 return prog;
1084 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
1085 prog = ERR_PTR(-EINVAL);
1086 goto out;
1087 }
1088
1089 prog = bpf_prog_inc(prog);
1090 out:
1091 fdput(f);
1092 return prog;
1093 }
1094
1095 struct bpf_prog *bpf_prog_get(u32 ufd)
1096 {
1097 return __bpf_prog_get(ufd, NULL, false);
1098 }
1099
1100 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
1101 bool attach_drv)
1102 {
1103 struct bpf_prog *prog = __bpf_prog_get(ufd, &type, attach_drv);
1104
1105 if (!IS_ERR(prog))
1106 trace_bpf_prog_get_type(prog);
1107 return prog;
1108 }
1109 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
1110
1111 /* last field in 'union bpf_attr' used by this command */
1112 #define BPF_PROG_LOAD_LAST_FIELD prog_ifindex
1113
1114 static int bpf_prog_load(union bpf_attr *attr)
1115 {
1116 enum bpf_prog_type type = attr->prog_type;
1117 struct bpf_prog *prog;
1118 int err;
1119 char license[128];
1120 bool is_gpl;
1121
1122 if (CHECK_ATTR(BPF_PROG_LOAD))
1123 return -EINVAL;
1124
1125 if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
1126 return -EINVAL;
1127
1128 /* copy eBPF program license from user space */
1129 if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
1130 sizeof(license) - 1) < 0)
1131 return -EFAULT;
1132 license[sizeof(license) - 1] = 0;
1133
1134 /* eBPF programs must be GPL compatible to use GPL-ed functions */
1135 is_gpl = license_is_gpl_compatible(license);
1136
1137 if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
1138 return -E2BIG;
1139
1140 if (type == BPF_PROG_TYPE_KPROBE &&
1141 attr->kern_version != LINUX_VERSION_CODE)
1142 return -EINVAL;
1143
1144 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
1145 type != BPF_PROG_TYPE_CGROUP_SKB &&
1146 !capable(CAP_SYS_ADMIN))
1147 return -EPERM;
1148
1149 /* plain bpf_prog allocation */
1150 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
1151 if (!prog)
1152 return -ENOMEM;
1153
1154 err = security_bpf_prog_alloc(prog->aux);
1155 if (err)
1156 goto free_prog_nouncharge;
1157
1158 err = bpf_prog_charge_memlock(prog);
1159 if (err)
1160 goto free_prog_sec;
1161
1162 prog->len = attr->insn_cnt;
1163
1164 err = -EFAULT;
1165 if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
1166 bpf_prog_insn_size(prog)) != 0)
1167 goto free_prog;
1168
1169 prog->orig_prog = NULL;
1170 prog->jited = 0;
1171
1172 atomic_set(&prog->aux->refcnt, 1);
1173 prog->gpl_compatible = is_gpl ? 1 : 0;
1174
1175 if (attr->prog_ifindex) {
1176 err = bpf_prog_offload_init(prog, attr);
1177 if (err)
1178 goto free_prog;
1179 }
1180
1181 /* find program type: socket_filter vs tracing_filter */
1182 err = find_prog_type(type, prog);
1183 if (err < 0)
1184 goto free_prog;
1185
1186 prog->aux->load_time = ktime_get_boot_ns();
1187 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name);
1188 if (err)
1189 goto free_prog;
1190
1191 /* run eBPF verifier */
1192 err = bpf_check(&prog, attr);
1193 if (err < 0)
1194 goto free_used_maps;
1195
1196 /* eBPF program is ready to be JITed */
1197 prog = bpf_prog_select_runtime(prog, &err);
1198 if (err < 0)
1199 goto free_used_maps;
1200
1201 err = bpf_prog_alloc_id(prog);
1202 if (err)
1203 goto free_used_maps;
1204
1205 err = bpf_prog_new_fd(prog);
1206 if (err < 0) {
1207 /* failed to allocate fd.
1208 * bpf_prog_put() is needed because the above
1209 * bpf_prog_alloc_id() has published the prog
1210 * to the userspace and the userspace may
1211 * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
1212 */
1213 bpf_prog_put(prog);
1214 return err;
1215 }
1216
1217 bpf_prog_kallsyms_add(prog);
1218 trace_bpf_prog_load(prog, err);
1219 return err;
1220
1221 free_used_maps:
1222 free_used_maps(prog->aux);
1223 free_prog:
1224 bpf_prog_uncharge_memlock(prog);
1225 free_prog_sec:
1226 security_bpf_prog_free(prog->aux);
1227 free_prog_nouncharge:
1228 bpf_prog_free(prog);
1229 return err;
1230 }
1231
1232 #define BPF_OBJ_LAST_FIELD file_flags
1233
1234 static int bpf_obj_pin(const union bpf_attr *attr)
1235 {
1236 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
1237 return -EINVAL;
1238
1239 return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
1240 }
1241
1242 static int bpf_obj_get(const union bpf_attr *attr)
1243 {
1244 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
1245 attr->file_flags & ~BPF_OBJ_FLAG_MASK)
1246 return -EINVAL;
1247
1248 return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
1249 attr->file_flags);
1250 }
1251
1252 #ifdef CONFIG_CGROUP_BPF
1253
1254 #define BPF_PROG_ATTACH_LAST_FIELD attach_flags
1255
1256 static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach)
1257 {
1258 struct bpf_prog *prog = NULL;
1259 int ufd = attr->target_fd;
1260 struct bpf_map *map;
1261 struct fd f;
1262 int err;
1263
1264 f = fdget(ufd);
1265 map = __bpf_map_get(f);
1266 if (IS_ERR(map))
1267 return PTR_ERR(map);
1268
1269 if (attach) {
1270 prog = bpf_prog_get_type(attr->attach_bpf_fd,
1271 BPF_PROG_TYPE_SK_SKB);
1272 if (IS_ERR(prog)) {
1273 fdput(f);
1274 return PTR_ERR(prog);
1275 }
1276 }
1277
1278 err = sock_map_prog(map, prog, attr->attach_type);
1279 if (err) {
1280 fdput(f);
1281 if (prog)
1282 bpf_prog_put(prog);
1283 return err;
1284 }
1285
1286 fdput(f);
1287 return 0;
1288 }
1289
1290 #define BPF_F_ATTACH_MASK \
1291 (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
1292
1293 static int bpf_prog_attach(const union bpf_attr *attr)
1294 {
1295 enum bpf_prog_type ptype;
1296 struct bpf_prog *prog;
1297 struct cgroup *cgrp;
1298 int ret;
1299
1300 if (!capable(CAP_NET_ADMIN))
1301 return -EPERM;
1302
1303 if (CHECK_ATTR(BPF_PROG_ATTACH))
1304 return -EINVAL;
1305
1306 if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
1307 return -EINVAL;
1308
1309 switch (attr->attach_type) {
1310 case BPF_CGROUP_INET_INGRESS:
1311 case BPF_CGROUP_INET_EGRESS:
1312 ptype = BPF_PROG_TYPE_CGROUP_SKB;
1313 break;
1314 case BPF_CGROUP_INET_SOCK_CREATE:
1315 ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1316 break;
1317 case BPF_CGROUP_SOCK_OPS:
1318 ptype = BPF_PROG_TYPE_SOCK_OPS;
1319 break;
1320 case BPF_CGROUP_DEVICE:
1321 ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1322 break;
1323 case BPF_SK_SKB_STREAM_PARSER:
1324 case BPF_SK_SKB_STREAM_VERDICT:
1325 return sockmap_get_from_fd(attr, true);
1326 default:
1327 return -EINVAL;
1328 }
1329
1330 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1331 if (IS_ERR(prog))
1332 return PTR_ERR(prog);
1333
1334 cgrp = cgroup_get_from_fd(attr->target_fd);
1335 if (IS_ERR(cgrp)) {
1336 bpf_prog_put(prog);
1337 return PTR_ERR(cgrp);
1338 }
1339
1340 ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type,
1341 attr->attach_flags);
1342 if (ret)
1343 bpf_prog_put(prog);
1344 cgroup_put(cgrp);
1345
1346 return ret;
1347 }
1348
1349 #define BPF_PROG_DETACH_LAST_FIELD attach_type
1350
1351 static int bpf_prog_detach(const union bpf_attr *attr)
1352 {
1353 enum bpf_prog_type ptype;
1354 struct bpf_prog *prog;
1355 struct cgroup *cgrp;
1356 int ret;
1357
1358 if (!capable(CAP_NET_ADMIN))
1359 return -EPERM;
1360
1361 if (CHECK_ATTR(BPF_PROG_DETACH))
1362 return -EINVAL;
1363
1364 switch (attr->attach_type) {
1365 case BPF_CGROUP_INET_INGRESS:
1366 case BPF_CGROUP_INET_EGRESS:
1367 ptype = BPF_PROG_TYPE_CGROUP_SKB;
1368 break;
1369 case BPF_CGROUP_INET_SOCK_CREATE:
1370 ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1371 break;
1372 case BPF_CGROUP_SOCK_OPS:
1373 ptype = BPF_PROG_TYPE_SOCK_OPS;
1374 break;
1375 case BPF_CGROUP_DEVICE:
1376 ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1377 break;
1378 case BPF_SK_SKB_STREAM_PARSER:
1379 case BPF_SK_SKB_STREAM_VERDICT:
1380 return sockmap_get_from_fd(attr, false);
1381 default:
1382 return -EINVAL;
1383 }
1384
1385 cgrp = cgroup_get_from_fd(attr->target_fd);
1386 if (IS_ERR(cgrp))
1387 return PTR_ERR(cgrp);
1388
1389 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1390 if (IS_ERR(prog))
1391 prog = NULL;
1392
1393 ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0);
1394 if (prog)
1395 bpf_prog_put(prog);
1396 cgroup_put(cgrp);
1397 return ret;
1398 }
1399
1400 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
1401
1402 static int bpf_prog_query(const union bpf_attr *attr,
1403 union bpf_attr __user *uattr)
1404 {
1405 struct cgroup *cgrp;
1406 int ret;
1407
1408 if (!capable(CAP_NET_ADMIN))
1409 return -EPERM;
1410 if (CHECK_ATTR(BPF_PROG_QUERY))
1411 return -EINVAL;
1412 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
1413 return -EINVAL;
1414
1415 switch (attr->query.attach_type) {
1416 case BPF_CGROUP_INET_INGRESS:
1417 case BPF_CGROUP_INET_EGRESS:
1418 case BPF_CGROUP_INET_SOCK_CREATE:
1419 case BPF_CGROUP_SOCK_OPS:
1420 case BPF_CGROUP_DEVICE:
1421 break;
1422 default:
1423 return -EINVAL;
1424 }
1425 cgrp = cgroup_get_from_fd(attr->query.target_fd);
1426 if (IS_ERR(cgrp))
1427 return PTR_ERR(cgrp);
1428 ret = cgroup_bpf_query(cgrp, attr, uattr);
1429 cgroup_put(cgrp);
1430 return ret;
1431 }
1432 #endif /* CONFIG_CGROUP_BPF */
1433
1434 #define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
1435
1436 static int bpf_prog_test_run(const union bpf_attr *attr,
1437 union bpf_attr __user *uattr)
1438 {
1439 struct bpf_prog *prog;
1440 int ret = -ENOTSUPP;
1441
1442 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
1443 return -EINVAL;
1444
1445 prog = bpf_prog_get(attr->test.prog_fd);
1446 if (IS_ERR(prog))
1447 return PTR_ERR(prog);
1448
1449 if (prog->aux->ops->test_run)
1450 ret = prog->aux->ops->test_run(prog, attr, uattr);
1451
1452 bpf_prog_put(prog);
1453 return ret;
1454 }
1455
1456 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
1457
1458 static int bpf_obj_get_next_id(const union bpf_attr *attr,
1459 union bpf_attr __user *uattr,
1460 struct idr *idr,
1461 spinlock_t *lock)
1462 {
1463 u32 next_id = attr->start_id;
1464 int err = 0;
1465
1466 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
1467 return -EINVAL;
1468
1469 if (!capable(CAP_SYS_ADMIN))
1470 return -EPERM;
1471
1472 next_id++;
1473 spin_lock_bh(lock);
1474 if (!idr_get_next(idr, &next_id))
1475 err = -ENOENT;
1476 spin_unlock_bh(lock);
1477
1478 if (!err)
1479 err = put_user(next_id, &uattr->next_id);
1480
1481 return err;
1482 }
1483
1484 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
1485
1486 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
1487 {
1488 struct bpf_prog *prog;
1489 u32 id = attr->prog_id;
1490 int fd;
1491
1492 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
1493 return -EINVAL;
1494
1495 if (!capable(CAP_SYS_ADMIN))
1496 return -EPERM;
1497
1498 spin_lock_bh(&prog_idr_lock);
1499 prog = idr_find(&prog_idr, id);
1500 if (prog)
1501 prog = bpf_prog_inc_not_zero(prog);
1502 else
1503 prog = ERR_PTR(-ENOENT);
1504 spin_unlock_bh(&prog_idr_lock);
1505
1506 if (IS_ERR(prog))
1507 return PTR_ERR(prog);
1508
1509 fd = bpf_prog_new_fd(prog);
1510 if (fd < 0)
1511 bpf_prog_put(prog);
1512
1513 return fd;
1514 }
1515
1516 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
1517
1518 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
1519 {
1520 struct bpf_map *map;
1521 u32 id = attr->map_id;
1522 int f_flags;
1523 int fd;
1524
1525 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
1526 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
1527 return -EINVAL;
1528
1529 if (!capable(CAP_SYS_ADMIN))
1530 return -EPERM;
1531
1532 f_flags = bpf_get_file_flag(attr->open_flags);
1533 if (f_flags < 0)
1534 return f_flags;
1535
1536 spin_lock_bh(&map_idr_lock);
1537 map = idr_find(&map_idr, id);
1538 if (map)
1539 map = bpf_map_inc_not_zero(map, true);
1540 else
1541 map = ERR_PTR(-ENOENT);
1542 spin_unlock_bh(&map_idr_lock);
1543
1544 if (IS_ERR(map))
1545 return PTR_ERR(map);
1546
1547 fd = bpf_map_new_fd(map, f_flags);
1548 if (fd < 0)
1549 bpf_map_put(map);
1550
1551 return fd;
1552 }
1553
1554 static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
1555 const union bpf_attr *attr,
1556 union bpf_attr __user *uattr)
1557 {
1558 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1559 struct bpf_prog_info info = {};
1560 u32 info_len = attr->info.info_len;
1561 char __user *uinsns;
1562 u32 ulen;
1563 int err;
1564
1565 err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1566 if (err)
1567 return err;
1568 info_len = min_t(u32, sizeof(info), info_len);
1569
1570 if (copy_from_user(&info, uinfo, info_len))
1571 return -EFAULT;
1572
1573 info.type = prog->type;
1574 info.id = prog->aux->id;
1575 info.load_time = prog->aux->load_time;
1576 info.created_by_uid = from_kuid_munged(current_user_ns(),
1577 prog->aux->user->uid);
1578
1579 memcpy(info.tag, prog->tag, sizeof(prog->tag));
1580 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
1581
1582 ulen = info.nr_map_ids;
1583 info.nr_map_ids = prog->aux->used_map_cnt;
1584 ulen = min_t(u32, info.nr_map_ids, ulen);
1585 if (ulen) {
1586 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
1587 u32 i;
1588
1589 for (i = 0; i < ulen; i++)
1590 if (put_user(prog->aux->used_maps[i]->id,
1591 &user_map_ids[i]))
1592 return -EFAULT;
1593 }
1594
1595 if (!capable(CAP_SYS_ADMIN)) {
1596 info.jited_prog_len = 0;
1597 info.xlated_prog_len = 0;
1598 goto done;
1599 }
1600
1601 ulen = info.jited_prog_len;
1602 info.jited_prog_len = prog->jited_len;
1603 if (info.jited_prog_len && ulen) {
1604 uinsns = u64_to_user_ptr(info.jited_prog_insns);
1605 ulen = min_t(u32, info.jited_prog_len, ulen);
1606 if (copy_to_user(uinsns, prog->bpf_func, ulen))
1607 return -EFAULT;
1608 }
1609
1610 ulen = info.xlated_prog_len;
1611 info.xlated_prog_len = bpf_prog_insn_size(prog);
1612 if (info.xlated_prog_len && ulen) {
1613 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
1614 ulen = min_t(u32, info.xlated_prog_len, ulen);
1615 if (copy_to_user(uinsns, prog->insnsi, ulen))
1616 return -EFAULT;
1617 }
1618
1619 done:
1620 if (copy_to_user(uinfo, &info, info_len) ||
1621 put_user(info_len, &uattr->info.info_len))
1622 return -EFAULT;
1623
1624 return 0;
1625 }
1626
1627 static int bpf_map_get_info_by_fd(struct bpf_map *map,
1628 const union bpf_attr *attr,
1629 union bpf_attr __user *uattr)
1630 {
1631 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1632 struct bpf_map_info info = {};
1633 u32 info_len = attr->info.info_len;
1634 int err;
1635
1636 err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1637 if (err)
1638 return err;
1639 info_len = min_t(u32, sizeof(info), info_len);
1640
1641 info.type = map->map_type;
1642 info.id = map->id;
1643 info.key_size = map->key_size;
1644 info.value_size = map->value_size;
1645 info.max_entries = map->max_entries;
1646 info.map_flags = map->map_flags;
1647 memcpy(info.name, map->name, sizeof(map->name));
1648
1649 if (copy_to_user(uinfo, &info, info_len) ||
1650 put_user(info_len, &uattr->info.info_len))
1651 return -EFAULT;
1652
1653 return 0;
1654 }
1655
1656 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
1657
1658 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
1659 union bpf_attr __user *uattr)
1660 {
1661 int ufd = attr->info.bpf_fd;
1662 struct fd f;
1663 int err;
1664
1665 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
1666 return -EINVAL;
1667
1668 f = fdget(ufd);
1669 if (!f.file)
1670 return -EBADFD;
1671
1672 if (f.file->f_op == &bpf_prog_fops)
1673 err = bpf_prog_get_info_by_fd(f.file->private_data, attr,
1674 uattr);
1675 else if (f.file->f_op == &bpf_map_fops)
1676 err = bpf_map_get_info_by_fd(f.file->private_data, attr,
1677 uattr);
1678 else
1679 err = -EINVAL;
1680
1681 fdput(f);
1682 return err;
1683 }
1684
1685 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
1686 {
1687 union bpf_attr attr = {};
1688 int err;
1689
1690 if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled)
1691 return -EPERM;
1692
1693 err = check_uarg_tail_zero(uattr, sizeof(attr), size);
1694 if (err)
1695 return err;
1696 size = min_t(u32, size, sizeof(attr));
1697
1698 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
1699 if (copy_from_user(&attr, uattr, size) != 0)
1700 return -EFAULT;
1701
1702 err = security_bpf(cmd, &attr, size);
1703 if (err < 0)
1704 return err;
1705
1706 switch (cmd) {
1707 case BPF_MAP_CREATE:
1708 err = map_create(&attr);
1709 break;
1710 case BPF_MAP_LOOKUP_ELEM:
1711 err = map_lookup_elem(&attr);
1712 break;
1713 case BPF_MAP_UPDATE_ELEM:
1714 err = map_update_elem(&attr);
1715 break;
1716 case BPF_MAP_DELETE_ELEM:
1717 err = map_delete_elem(&attr);
1718 break;
1719 case BPF_MAP_GET_NEXT_KEY:
1720 err = map_get_next_key(&attr);
1721 break;
1722 case BPF_PROG_LOAD:
1723 err = bpf_prog_load(&attr);
1724 break;
1725 case BPF_OBJ_PIN:
1726 err = bpf_obj_pin(&attr);
1727 break;
1728 case BPF_OBJ_GET:
1729 err = bpf_obj_get(&attr);
1730 break;
1731 #ifdef CONFIG_CGROUP_BPF
1732 case BPF_PROG_ATTACH:
1733 err = bpf_prog_attach(&attr);
1734 break;
1735 case BPF_PROG_DETACH:
1736 err = bpf_prog_detach(&attr);
1737 break;
1738 case BPF_PROG_QUERY:
1739 err = bpf_prog_query(&attr, uattr);
1740 break;
1741 #endif
1742 case BPF_PROG_TEST_RUN:
1743 err = bpf_prog_test_run(&attr, uattr);
1744 break;
1745 case BPF_PROG_GET_NEXT_ID:
1746 err = bpf_obj_get_next_id(&attr, uattr,
1747 &prog_idr, &prog_idr_lock);
1748 break;
1749 case BPF_MAP_GET_NEXT_ID:
1750 err = bpf_obj_get_next_id(&attr, uattr,
1751 &map_idr, &map_idr_lock);
1752 break;
1753 case BPF_PROG_GET_FD_BY_ID:
1754 err = bpf_prog_get_fd_by_id(&attr);
1755 break;
1756 case BPF_MAP_GET_FD_BY_ID:
1757 err = bpf_map_get_fd_by_id(&attr);
1758 break;
1759 case BPF_OBJ_GET_INFO_BY_FD:
1760 err = bpf_obj_get_info_by_fd(&attr, uattr);
1761 break;
1762 default:
1763 err = -EINVAL;
1764 break;
1765 }
1766
1767 return err;
1768 }
Linux with added FPC-III support