Merge branch 'cpsw-phy-handle-fixes'
[deliverable/linux.git] / kernel / bpf / syscall.c
CommitLineData
99c55f7d
AS
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/syscalls.h>
14#include <linux/slab.h>
15#include <linux/anon_inodes.h>
db20fd2b 16#include <linux/file.h>
09756af4
AS
17#include <linux/license.h>
18#include <linux/filter.h>
2541517c 19#include <linux/version.h>
99c55f7d 20
b121d1e7
AS
21DEFINE_PER_CPU(int, bpf_prog_active);
22
1be7f75d
AS
23int sysctl_unprivileged_bpf_disabled __read_mostly;
24
99c55f7d
AS
25static LIST_HEAD(bpf_map_types);
26
27static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
28{
29 struct bpf_map_type_list *tl;
30 struct bpf_map *map;
31
32 list_for_each_entry(tl, &bpf_map_types, list_node) {
33 if (tl->type == attr->map_type) {
34 map = tl->ops->map_alloc(attr);
35 if (IS_ERR(map))
36 return map;
37 map->ops = tl->ops;
38 map->map_type = attr->map_type;
39 return map;
40 }
41 }
42 return ERR_PTR(-EINVAL);
43}
44
45/* boot time registration of different map implementations */
46void bpf_register_map_type(struct bpf_map_type_list *tl)
47{
48 list_add(&tl->list_node, &bpf_map_types);
49}
50
6c905981
AS
51int bpf_map_precharge_memlock(u32 pages)
52{
53 struct user_struct *user = get_current_user();
54 unsigned long memlock_limit, cur;
55
56 memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
57 cur = atomic_long_read(&user->locked_vm);
58 free_uid(user);
59 if (cur + pages > memlock_limit)
60 return -EPERM;
61 return 0;
62}
63
aaac3ba9
AS
64static int bpf_map_charge_memlock(struct bpf_map *map)
65{
66 struct user_struct *user = get_current_user();
67 unsigned long memlock_limit;
68
69 memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
70
71 atomic_long_add(map->pages, &user->locked_vm);
72
73 if (atomic_long_read(&user->locked_vm) > memlock_limit) {
74 atomic_long_sub(map->pages, &user->locked_vm);
75 free_uid(user);
76 return -EPERM;
77 }
78 map->user = user;
79 return 0;
80}
81
82static void bpf_map_uncharge_memlock(struct bpf_map *map)
83{
84 struct user_struct *user = map->user;
85
86 atomic_long_sub(map->pages, &user->locked_vm);
87 free_uid(user);
88}
89
99c55f7d
AS
90/* called from workqueue */
91static void bpf_map_free_deferred(struct work_struct *work)
92{
93 struct bpf_map *map = container_of(work, struct bpf_map, work);
94
aaac3ba9 95 bpf_map_uncharge_memlock(map);
99c55f7d
AS
96 /* implementation dependent freeing */
97 map->ops->map_free(map);
98}
99
c9da161c
DB
100static void bpf_map_put_uref(struct bpf_map *map)
101{
102 if (atomic_dec_and_test(&map->usercnt)) {
103 if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
104 bpf_fd_array_map_clear(map);
105 }
106}
107
99c55f7d
AS
108/* decrement map refcnt and schedule it for freeing via workqueue
109 * (unrelying map implementation ops->map_free() might sleep)
110 */
111void bpf_map_put(struct bpf_map *map)
112{
113 if (atomic_dec_and_test(&map->refcnt)) {
114 INIT_WORK(&map->work, bpf_map_free_deferred);
115 schedule_work(&map->work);
116 }
117}
118
c9da161c 119void bpf_map_put_with_uref(struct bpf_map *map)
99c55f7d 120{
c9da161c 121 bpf_map_put_uref(map);
99c55f7d 122 bpf_map_put(map);
c9da161c
DB
123}
124
125static int bpf_map_release(struct inode *inode, struct file *filp)
126{
127 bpf_map_put_with_uref(filp->private_data);
99c55f7d
AS
128 return 0;
129}
130
f99bf205
DB
131#ifdef CONFIG_PROC_FS
132static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
133{
134 const struct bpf_map *map = filp->private_data;
135
136 seq_printf(m,
137 "map_type:\t%u\n"
138 "key_size:\t%u\n"
139 "value_size:\t%u\n"
322cea2f
DB
140 "max_entries:\t%u\n"
141 "map_flags:\t%#x\n",
f99bf205
DB
142 map->map_type,
143 map->key_size,
144 map->value_size,
322cea2f
DB
145 map->max_entries,
146 map->map_flags);
f99bf205
DB
147}
148#endif
149
99c55f7d 150static const struct file_operations bpf_map_fops = {
f99bf205
DB
151#ifdef CONFIG_PROC_FS
152 .show_fdinfo = bpf_map_show_fdinfo,
153#endif
154 .release = bpf_map_release,
99c55f7d
AS
155};
156
b2197755 157int bpf_map_new_fd(struct bpf_map *map)
aa79781b
DB
158{
159 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
160 O_RDWR | O_CLOEXEC);
161}
162
99c55f7d
AS
163/* helper macro to check that unused fields 'union bpf_attr' are zero */
164#define CHECK_ATTR(CMD) \
165 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
166 sizeof(attr->CMD##_LAST_FIELD), 0, \
167 sizeof(*attr) - \
168 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
169 sizeof(attr->CMD##_LAST_FIELD)) != NULL
170
6c905981 171#define BPF_MAP_CREATE_LAST_FIELD map_flags
99c55f7d
AS
172/* called via syscall */
173static int map_create(union bpf_attr *attr)
174{
175 struct bpf_map *map;
176 int err;
177
178 err = CHECK_ATTR(BPF_MAP_CREATE);
179 if (err)
180 return -EINVAL;
181
182 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
183 map = find_and_alloc_map(attr);
184 if (IS_ERR(map))
185 return PTR_ERR(map);
186
187 atomic_set(&map->refcnt, 1);
c9da161c 188 atomic_set(&map->usercnt, 1);
99c55f7d 189
aaac3ba9
AS
190 err = bpf_map_charge_memlock(map);
191 if (err)
192 goto free_map;
193
aa79781b 194 err = bpf_map_new_fd(map);
99c55f7d
AS
195 if (err < 0)
196 /* failed to allocate fd */
197 goto free_map;
198
199 return err;
200
201free_map:
202 map->ops->map_free(map);
203 return err;
204}
205
db20fd2b
AS
206/* if error is returned, fd is released.
207 * On success caller should complete fd access with matching fdput()
208 */
c2101297 209struct bpf_map *__bpf_map_get(struct fd f)
db20fd2b 210{
db20fd2b
AS
211 if (!f.file)
212 return ERR_PTR(-EBADF);
db20fd2b
AS
213 if (f.file->f_op != &bpf_map_fops) {
214 fdput(f);
215 return ERR_PTR(-EINVAL);
216 }
217
c2101297
DB
218 return f.file->private_data;
219}
220
c9da161c
DB
221void bpf_map_inc(struct bpf_map *map, bool uref)
222{
223 atomic_inc(&map->refcnt);
224 if (uref)
225 atomic_inc(&map->usercnt);
226}
227
228struct bpf_map *bpf_map_get_with_uref(u32 ufd)
c2101297
DB
229{
230 struct fd f = fdget(ufd);
231 struct bpf_map *map;
232
233 map = __bpf_map_get(f);
234 if (IS_ERR(map))
235 return map;
236
c9da161c 237 bpf_map_inc(map, true);
c2101297 238 fdput(f);
db20fd2b
AS
239
240 return map;
241}
242
243/* helper to convert user pointers passed inside __aligned_u64 fields */
244static void __user *u64_to_ptr(__u64 val)
245{
246 return (void __user *) (unsigned long) val;
247}
248
b8cdc051
AS
249int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
250{
251 return -ENOTSUPP;
252}
253
db20fd2b
AS
254/* last field in 'union bpf_attr' used by this command */
255#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
256
257static int map_lookup_elem(union bpf_attr *attr)
258{
259 void __user *ukey = u64_to_ptr(attr->key);
260 void __user *uvalue = u64_to_ptr(attr->value);
261 int ufd = attr->map_fd;
db20fd2b 262 struct bpf_map *map;
8ebe667c 263 void *key, *value, *ptr;
15a07b33 264 u32 value_size;
592867bf 265 struct fd f;
db20fd2b
AS
266 int err;
267
268 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
269 return -EINVAL;
270
592867bf 271 f = fdget(ufd);
c2101297 272 map = __bpf_map_get(f);
db20fd2b
AS
273 if (IS_ERR(map))
274 return PTR_ERR(map);
275
276 err = -ENOMEM;
277 key = kmalloc(map->key_size, GFP_USER);
278 if (!key)
279 goto err_put;
280
281 err = -EFAULT;
282 if (copy_from_user(key, ukey, map->key_size) != 0)
283 goto free_key;
284
15a07b33
AS
285 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
286 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
287 value_size = round_up(map->value_size, 8) * num_possible_cpus();
288 else
289 value_size = map->value_size;
290
8ebe667c 291 err = -ENOMEM;
15a07b33 292 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
db20fd2b 293 if (!value)
8ebe667c
AS
294 goto free_key;
295
15a07b33
AS
296 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH) {
297 err = bpf_percpu_hash_copy(map, key, value);
298 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
299 err = bpf_percpu_array_copy(map, key, value);
557c0c6e
AS
300 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
301 err = bpf_stackmap_copy(map, key, value);
15a07b33
AS
302 } else {
303 rcu_read_lock();
304 ptr = map->ops->map_lookup_elem(map, key);
305 if (ptr)
306 memcpy(value, ptr, value_size);
307 rcu_read_unlock();
308 err = ptr ? 0 : -ENOENT;
309 }
8ebe667c 310
15a07b33 311 if (err)
8ebe667c 312 goto free_value;
db20fd2b
AS
313
314 err = -EFAULT;
15a07b33 315 if (copy_to_user(uvalue, value, value_size) != 0)
8ebe667c 316 goto free_value;
db20fd2b
AS
317
318 err = 0;
319
8ebe667c
AS
320free_value:
321 kfree(value);
db20fd2b
AS
322free_key:
323 kfree(key);
324err_put:
325 fdput(f);
326 return err;
327}
328
3274f520 329#define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
db20fd2b
AS
330
331static int map_update_elem(union bpf_attr *attr)
332{
333 void __user *ukey = u64_to_ptr(attr->key);
334 void __user *uvalue = u64_to_ptr(attr->value);
335 int ufd = attr->map_fd;
db20fd2b
AS
336 struct bpf_map *map;
337 void *key, *value;
15a07b33 338 u32 value_size;
592867bf 339 struct fd f;
db20fd2b
AS
340 int err;
341
342 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
343 return -EINVAL;
344
592867bf 345 f = fdget(ufd);
c2101297 346 map = __bpf_map_get(f);
db20fd2b
AS
347 if (IS_ERR(map))
348 return PTR_ERR(map);
349
350 err = -ENOMEM;
351 key = kmalloc(map->key_size, GFP_USER);
352 if (!key)
353 goto err_put;
354
355 err = -EFAULT;
356 if (copy_from_user(key, ukey, map->key_size) != 0)
357 goto free_key;
358
15a07b33
AS
359 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
360 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
361 value_size = round_up(map->value_size, 8) * num_possible_cpus();
362 else
363 value_size = map->value_size;
364
db20fd2b 365 err = -ENOMEM;
15a07b33 366 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
db20fd2b
AS
367 if (!value)
368 goto free_key;
369
370 err = -EFAULT;
15a07b33 371 if (copy_from_user(value, uvalue, value_size) != 0)
db20fd2b
AS
372 goto free_value;
373
b121d1e7
AS
374 /* must increment bpf_prog_active to avoid kprobe+bpf triggering from
375 * inside bpf map update or delete otherwise deadlocks are possible
376 */
377 preempt_disable();
378 __this_cpu_inc(bpf_prog_active);
15a07b33
AS
379 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH) {
380 err = bpf_percpu_hash_update(map, key, value, attr->flags);
381 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
382 err = bpf_percpu_array_update(map, key, value, attr->flags);
383 } else {
384 rcu_read_lock();
385 err = map->ops->map_update_elem(map, key, value, attr->flags);
386 rcu_read_unlock();
387 }
b121d1e7
AS
388 __this_cpu_dec(bpf_prog_active);
389 preempt_enable();
db20fd2b
AS
390
391free_value:
392 kfree(value);
393free_key:
394 kfree(key);
395err_put:
396 fdput(f);
397 return err;
398}
399
400#define BPF_MAP_DELETE_ELEM_LAST_FIELD key
401
402static int map_delete_elem(union bpf_attr *attr)
403{
404 void __user *ukey = u64_to_ptr(attr->key);
405 int ufd = attr->map_fd;
db20fd2b 406 struct bpf_map *map;
592867bf 407 struct fd f;
db20fd2b
AS
408 void *key;
409 int err;
410
411 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
412 return -EINVAL;
413
592867bf 414 f = fdget(ufd);
c2101297 415 map = __bpf_map_get(f);
db20fd2b
AS
416 if (IS_ERR(map))
417 return PTR_ERR(map);
418
419 err = -ENOMEM;
420 key = kmalloc(map->key_size, GFP_USER);
421 if (!key)
422 goto err_put;
423
424 err = -EFAULT;
425 if (copy_from_user(key, ukey, map->key_size) != 0)
426 goto free_key;
427
b121d1e7
AS
428 preempt_disable();
429 __this_cpu_inc(bpf_prog_active);
db20fd2b
AS
430 rcu_read_lock();
431 err = map->ops->map_delete_elem(map, key);
432 rcu_read_unlock();
b121d1e7
AS
433 __this_cpu_dec(bpf_prog_active);
434 preempt_enable();
db20fd2b
AS
435
436free_key:
437 kfree(key);
438err_put:
439 fdput(f);
440 return err;
441}
442
443/* last field in 'union bpf_attr' used by this command */
444#define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
445
446static int map_get_next_key(union bpf_attr *attr)
447{
448 void __user *ukey = u64_to_ptr(attr->key);
449 void __user *unext_key = u64_to_ptr(attr->next_key);
450 int ufd = attr->map_fd;
db20fd2b
AS
451 struct bpf_map *map;
452 void *key, *next_key;
592867bf 453 struct fd f;
db20fd2b
AS
454 int err;
455
456 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
457 return -EINVAL;
458
592867bf 459 f = fdget(ufd);
c2101297 460 map = __bpf_map_get(f);
db20fd2b
AS
461 if (IS_ERR(map))
462 return PTR_ERR(map);
463
464 err = -ENOMEM;
465 key = kmalloc(map->key_size, GFP_USER);
466 if (!key)
467 goto err_put;
468
469 err = -EFAULT;
470 if (copy_from_user(key, ukey, map->key_size) != 0)
471 goto free_key;
472
473 err = -ENOMEM;
474 next_key = kmalloc(map->key_size, GFP_USER);
475 if (!next_key)
476 goto free_key;
477
478 rcu_read_lock();
479 err = map->ops->map_get_next_key(map, key, next_key);
480 rcu_read_unlock();
481 if (err)
482 goto free_next_key;
483
484 err = -EFAULT;
485 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
486 goto free_next_key;
487
488 err = 0;
489
490free_next_key:
491 kfree(next_key);
492free_key:
493 kfree(key);
494err_put:
495 fdput(f);
496 return err;
497}
498
09756af4
AS
499static LIST_HEAD(bpf_prog_types);
500
501static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
502{
503 struct bpf_prog_type_list *tl;
504
505 list_for_each_entry(tl, &bpf_prog_types, list_node) {
506 if (tl->type == type) {
507 prog->aux->ops = tl->ops;
24701ece 508 prog->type = type;
09756af4
AS
509 return 0;
510 }
511 }
24701ece 512
09756af4
AS
513 return -EINVAL;
514}
515
516void bpf_register_prog_type(struct bpf_prog_type_list *tl)
517{
518 list_add(&tl->list_node, &bpf_prog_types);
519}
520
0a542a86
AS
521/* fixup insn->imm field of bpf_call instructions:
522 * if (insn->imm == BPF_FUNC_map_lookup_elem)
523 * insn->imm = bpf_map_lookup_elem - __bpf_call_base;
524 * else if (insn->imm == BPF_FUNC_map_update_elem)
525 * insn->imm = bpf_map_update_elem - __bpf_call_base;
526 * else ...
527 *
528 * this function is called after eBPF program passed verification
529 */
530static void fixup_bpf_calls(struct bpf_prog *prog)
531{
532 const struct bpf_func_proto *fn;
533 int i;
534
535 for (i = 0; i < prog->len; i++) {
536 struct bpf_insn *insn = &prog->insnsi[i];
537
538 if (insn->code == (BPF_JMP | BPF_CALL)) {
539 /* we reach here when program has bpf_call instructions
540 * and it passed bpf_check(), means that
541 * ops->get_func_proto must have been supplied, check it
542 */
543 BUG_ON(!prog->aux->ops->get_func_proto);
544
c46646d0
DB
545 if (insn->imm == BPF_FUNC_get_route_realm)
546 prog->dst_needed = 1;
3ad00405
DB
547 if (insn->imm == BPF_FUNC_get_prandom_u32)
548 bpf_user_rnd_init_once();
04fd61ab
AS
549 if (insn->imm == BPF_FUNC_tail_call) {
550 /* mark bpf_tail_call as different opcode
551 * to avoid conditional branch in
552 * interpeter for every normal call
553 * and to prevent accidental JITing by
554 * JIT compiler that doesn't support
555 * bpf_tail_call yet
556 */
557 insn->imm = 0;
558 insn->code |= BPF_X;
559 continue;
560 }
561
0a542a86
AS
562 fn = prog->aux->ops->get_func_proto(insn->imm);
563 /* all functions that have prototype and verifier allowed
564 * programs to call them, must be real in-kernel functions
565 */
566 BUG_ON(!fn->func);
567 insn->imm = fn->func - __bpf_call_base;
568 }
569 }
570}
571
09756af4
AS
572/* drop refcnt on maps used by eBPF program and free auxilary data */
573static void free_used_maps(struct bpf_prog_aux *aux)
574{
575 int i;
576
577 for (i = 0; i < aux->used_map_cnt; i++)
578 bpf_map_put(aux->used_maps[i]);
579
580 kfree(aux->used_maps);
581}
582
aaac3ba9
AS
583static int bpf_prog_charge_memlock(struct bpf_prog *prog)
584{
585 struct user_struct *user = get_current_user();
586 unsigned long memlock_limit;
587
588 memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
589
590 atomic_long_add(prog->pages, &user->locked_vm);
591 if (atomic_long_read(&user->locked_vm) > memlock_limit) {
592 atomic_long_sub(prog->pages, &user->locked_vm);
593 free_uid(user);
594 return -EPERM;
595 }
596 prog->aux->user = user;
597 return 0;
598}
599
600static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
601{
602 struct user_struct *user = prog->aux->user;
603
604 atomic_long_sub(prog->pages, &user->locked_vm);
605 free_uid(user);
606}
607
e9d8afa9 608static void __prog_put_common(struct rcu_head *rcu)
abf2e7d6
AS
609{
610 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
611
612 free_used_maps(aux);
aaac3ba9 613 bpf_prog_uncharge_memlock(aux->prog);
abf2e7d6
AS
614 bpf_prog_free(aux->prog);
615}
616
617/* version of bpf_prog_put() that is called after a grace period */
618void bpf_prog_put_rcu(struct bpf_prog *prog)
619{
e9d8afa9
DB
620 if (atomic_dec_and_test(&prog->aux->refcnt))
621 call_rcu(&prog->aux->rcu, __prog_put_common);
abf2e7d6
AS
622}
623
09756af4
AS
624void bpf_prog_put(struct bpf_prog *prog)
625{
e9d8afa9
DB
626 if (atomic_dec_and_test(&prog->aux->refcnt))
627 __prog_put_common(&prog->aux->rcu);
09756af4 628}
e2e9b654 629EXPORT_SYMBOL_GPL(bpf_prog_put);
09756af4
AS
630
631static int bpf_prog_release(struct inode *inode, struct file *filp)
632{
633 struct bpf_prog *prog = filp->private_data;
634
abf2e7d6 635 bpf_prog_put_rcu(prog);
09756af4
AS
636 return 0;
637}
638
639static const struct file_operations bpf_prog_fops = {
640 .release = bpf_prog_release,
641};
642
b2197755 643int bpf_prog_new_fd(struct bpf_prog *prog)
aa79781b
DB
644{
645 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
646 O_RDWR | O_CLOEXEC);
647}
648
c2101297 649static struct bpf_prog *__bpf_prog_get(struct fd f)
09756af4 650{
09756af4
AS
651 if (!f.file)
652 return ERR_PTR(-EBADF);
09756af4
AS
653 if (f.file->f_op != &bpf_prog_fops) {
654 fdput(f);
655 return ERR_PTR(-EINVAL);
656 }
657
c2101297 658 return f.file->private_data;
09756af4
AS
659}
660
661/* called by sockets/tracing/seccomp before attaching program to an event
662 * pairs with bpf_prog_put()
663 */
664struct bpf_prog *bpf_prog_get(u32 ufd)
665{
666 struct fd f = fdget(ufd);
667 struct bpf_prog *prog;
668
c2101297 669 prog = __bpf_prog_get(f);
09756af4
AS
670 if (IS_ERR(prog))
671 return prog;
672
673 atomic_inc(&prog->aux->refcnt);
674 fdput(f);
c2101297 675
09756af4
AS
676 return prog;
677}
e2e9b654 678EXPORT_SYMBOL_GPL(bpf_prog_get);
09756af4
AS
679
680/* last field in 'union bpf_attr' used by this command */
2541517c 681#define BPF_PROG_LOAD_LAST_FIELD kern_version
09756af4
AS
682
683static int bpf_prog_load(union bpf_attr *attr)
684{
685 enum bpf_prog_type type = attr->prog_type;
686 struct bpf_prog *prog;
687 int err;
688 char license[128];
689 bool is_gpl;
690
691 if (CHECK_ATTR(BPF_PROG_LOAD))
692 return -EINVAL;
693
694 /* copy eBPF program license from user space */
695 if (strncpy_from_user(license, u64_to_ptr(attr->license),
696 sizeof(license) - 1) < 0)
697 return -EFAULT;
698 license[sizeof(license) - 1] = 0;
699
700 /* eBPF programs must be GPL compatible to use GPL-ed functions */
701 is_gpl = license_is_gpl_compatible(license);
702
703 if (attr->insn_cnt >= BPF_MAXINSNS)
704 return -EINVAL;
705
2541517c
AS
706 if (type == BPF_PROG_TYPE_KPROBE &&
707 attr->kern_version != LINUX_VERSION_CODE)
708 return -EINVAL;
709
1be7f75d
AS
710 if (type != BPF_PROG_TYPE_SOCKET_FILTER && !capable(CAP_SYS_ADMIN))
711 return -EPERM;
712
09756af4
AS
713 /* plain bpf_prog allocation */
714 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
715 if (!prog)
716 return -ENOMEM;
717
aaac3ba9
AS
718 err = bpf_prog_charge_memlock(prog);
719 if (err)
720 goto free_prog_nouncharge;
721
09756af4
AS
722 prog->len = attr->insn_cnt;
723
724 err = -EFAULT;
725 if (copy_from_user(prog->insns, u64_to_ptr(attr->insns),
726 prog->len * sizeof(struct bpf_insn)) != 0)
727 goto free_prog;
728
729 prog->orig_prog = NULL;
a91263d5 730 prog->jited = 0;
09756af4
AS
731
732 atomic_set(&prog->aux->refcnt, 1);
a91263d5 733 prog->gpl_compatible = is_gpl ? 1 : 0;
09756af4
AS
734
735 /* find program type: socket_filter vs tracing_filter */
736 err = find_prog_type(type, prog);
737 if (err < 0)
738 goto free_prog;
739
740 /* run eBPF verifier */
9bac3d6d 741 err = bpf_check(&prog, attr);
09756af4
AS
742 if (err < 0)
743 goto free_used_maps;
744
0a542a86
AS
745 /* fixup BPF_CALL->imm field */
746 fixup_bpf_calls(prog);
747
09756af4 748 /* eBPF program is ready to be JITed */
04fd61ab
AS
749 err = bpf_prog_select_runtime(prog);
750 if (err < 0)
751 goto free_used_maps;
09756af4 752
aa79781b 753 err = bpf_prog_new_fd(prog);
09756af4
AS
754 if (err < 0)
755 /* failed to allocate fd */
756 goto free_used_maps;
757
758 return err;
759
760free_used_maps:
761 free_used_maps(prog->aux);
762free_prog:
aaac3ba9
AS
763 bpf_prog_uncharge_memlock(prog);
764free_prog_nouncharge:
09756af4
AS
765 bpf_prog_free(prog);
766 return err;
767}
768
b2197755
DB
769#define BPF_OBJ_LAST_FIELD bpf_fd
770
771static int bpf_obj_pin(const union bpf_attr *attr)
772{
773 if (CHECK_ATTR(BPF_OBJ))
774 return -EINVAL;
775
776 return bpf_obj_pin_user(attr->bpf_fd, u64_to_ptr(attr->pathname));
777}
778
779static int bpf_obj_get(const union bpf_attr *attr)
780{
781 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0)
782 return -EINVAL;
783
784 return bpf_obj_get_user(u64_to_ptr(attr->pathname));
785}
786
99c55f7d
AS
787SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
788{
789 union bpf_attr attr = {};
790 int err;
791
1be7f75d 792 if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled)
99c55f7d
AS
793 return -EPERM;
794
795 if (!access_ok(VERIFY_READ, uattr, 1))
796 return -EFAULT;
797
798 if (size > PAGE_SIZE) /* silly large */
799 return -E2BIG;
800
801 /* If we're handed a bigger struct than we know of,
802 * ensure all the unknown bits are 0 - i.e. new
803 * user-space does not rely on any kernel feature
804 * extensions we dont know about yet.
805 */
806 if (size > sizeof(attr)) {
807 unsigned char __user *addr;
808 unsigned char __user *end;
809 unsigned char val;
810
811 addr = (void __user *)uattr + sizeof(attr);
812 end = (void __user *)uattr + size;
813
814 for (; addr < end; addr++) {
815 err = get_user(val, addr);
816 if (err)
817 return err;
818 if (val)
819 return -E2BIG;
820 }
821 size = sizeof(attr);
822 }
823
824 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
825 if (copy_from_user(&attr, uattr, size) != 0)
826 return -EFAULT;
827
828 switch (cmd) {
829 case BPF_MAP_CREATE:
830 err = map_create(&attr);
831 break;
db20fd2b
AS
832 case BPF_MAP_LOOKUP_ELEM:
833 err = map_lookup_elem(&attr);
834 break;
835 case BPF_MAP_UPDATE_ELEM:
836 err = map_update_elem(&attr);
837 break;
838 case BPF_MAP_DELETE_ELEM:
839 err = map_delete_elem(&attr);
840 break;
841 case BPF_MAP_GET_NEXT_KEY:
842 err = map_get_next_key(&attr);
843 break;
09756af4
AS
844 case BPF_PROG_LOAD:
845 err = bpf_prog_load(&attr);
846 break;
b2197755
DB
847 case BPF_OBJ_PIN:
848 err = bpf_obj_pin(&attr);
849 break;
850 case BPF_OBJ_GET:
851 err = bpf_obj_get(&attr);
852 break;
99c55f7d
AS
853 default:
854 err = -EINVAL;
855 break;
856 }
857
858 return err;
859}
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