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/bpf_lirc.h>
15 #include <linux/btf.h>
16 #include <linux/syscalls.h>
17 #include <linux/slab.h>
18 #include <linux/sched/signal.h>
19 #include <linux/vmalloc.h>
20 #include <linux/mmzone.h>
21 #include <linux/anon_inodes.h>
22 #include <linux/fdtable.h>
23 #include <linux/file.h>
24 #include <linux/fs.h>
25 #include <linux/license.h>
26 #include <linux/filter.h>
27 #include <linux/version.h>
28 #include <linux/kernel.h>
29 #include <linux/idr.h>
30 #include <linux/cred.h>
31 #include <linux/timekeeping.h>
32 #include <linux/ctype.h>
33 #include <linux/btf.h>
34 #include <linux/nospec.h>
35
36 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
37 (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
38 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
39 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
40 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
41 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map))
42
43 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY)
44
45 DEFINE_PER_CPU(int, bpf_prog_active);
46 static DEFINE_IDR(prog_idr);
47 static DEFINE_SPINLOCK(prog_idr_lock);
48 static DEFINE_IDR(map_idr);
49 static DEFINE_SPINLOCK(map_idr_lock);
50
51 int sysctl_unprivileged_bpf_disabled __read_mostly;
52
53 static const struct bpf_map_ops * const bpf_map_types[] = {
54 #define BPF_PROG_TYPE(_id, _ops)
55 #define BPF_MAP_TYPE(_id, _ops) \
56 [_id] = &_ops,
57 #include <linux/bpf_types.h>
58 #undef BPF_PROG_TYPE
59 #undef BPF_MAP_TYPE
60 };
61
62 /*
63 * If we're handed a bigger struct than we know of, ensure all the unknown bits
64 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
65 * we don't know about yet.
66 *
67 * There is a ToCToU between this function call and the following
68 * copy_from_user() call. However, this is not a concern since this function is
69 * meant to be a future-proofing of bits.
70 */
bpf_check_uarg_tail_zero(void __user * uaddr,size_t expected_size,size_t actual_size)71 int bpf_check_uarg_tail_zero(void __user *uaddr,
72 size_t expected_size,
73 size_t actual_size)
74 {
75 unsigned char __user *addr;
76 unsigned char __user *end;
77 unsigned char val;
78 int err;
79
80 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
81 return -E2BIG;
82
83 if (unlikely(!access_ok(VERIFY_READ, uaddr, actual_size)))
84 return -EFAULT;
85
86 if (actual_size <= expected_size)
87 return 0;
88
89 addr = uaddr + expected_size;
90 end = uaddr + actual_size;
91
92 for (; addr < end; addr++) {
93 err = get_user(val, addr);
94 if (err)
95 return err;
96 if (val)
97 return -E2BIG;
98 }
99
100 return 0;
101 }
102
103 const struct bpf_map_ops bpf_map_offload_ops = {
104 .map_alloc = bpf_map_offload_map_alloc,
105 .map_free = bpf_map_offload_map_free,
106 .map_check_btf = map_check_no_btf,
107 };
108
find_and_alloc_map(union bpf_attr * attr)109 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
110 {
111 const struct bpf_map_ops *ops;
112 u32 type = attr->map_type;
113 struct bpf_map *map;
114 int err;
115
116 if (type >= ARRAY_SIZE(bpf_map_types))
117 return ERR_PTR(-EINVAL);
118 type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
119 ops = bpf_map_types[type];
120 if (!ops)
121 return ERR_PTR(-EINVAL);
122
123 if (ops->map_alloc_check) {
124 err = ops->map_alloc_check(attr);
125 if (err)
126 return ERR_PTR(err);
127 }
128 if (attr->map_ifindex)
129 ops = &bpf_map_offload_ops;
130 map = ops->map_alloc(attr);
131 if (IS_ERR(map))
132 return map;
133 map->ops = ops;
134 map->map_type = type;
135 return map;
136 }
137
bpf_map_area_alloc(size_t size,int numa_node)138 void *bpf_map_area_alloc(size_t size, int numa_node)
139 {
140 /* We definitely need __GFP_NORETRY, so OOM killer doesn't
141 * trigger under memory pressure as we really just want to
142 * fail instead.
143 */
144 const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
145 void *area;
146
147 if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
148 area = kmalloc_node(size, GFP_USER | flags, numa_node);
149 if (area != NULL)
150 return area;
151 }
152
153 return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
154 __builtin_return_address(0));
155 }
156
bpf_map_area_free(void * area)157 void bpf_map_area_free(void *area)
158 {
159 kvfree(area);
160 }
161
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)162 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
163 {
164 map->map_type = attr->map_type;
165 map->key_size = attr->key_size;
166 map->value_size = attr->value_size;
167 map->max_entries = attr->max_entries;
168 map->map_flags = attr->map_flags;
169 map->numa_node = bpf_map_attr_numa_node(attr);
170 }
171
bpf_map_precharge_memlock(u32 pages)172 int bpf_map_precharge_memlock(u32 pages)
173 {
174 struct user_struct *user = get_current_user();
175 unsigned long memlock_limit, cur;
176
177 memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
178 cur = atomic_long_read(&user->locked_vm);
179 free_uid(user);
180 if (cur + pages > memlock_limit)
181 return -EPERM;
182 return 0;
183 }
184
bpf_charge_memlock(struct user_struct * user,u32 pages)185 static int bpf_charge_memlock(struct user_struct *user, u32 pages)
186 {
187 unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
188
189 if (atomic_long_add_return(pages, &user->locked_vm) > memlock_limit) {
190 atomic_long_sub(pages, &user->locked_vm);
191 return -EPERM;
192 }
193 return 0;
194 }
195
bpf_uncharge_memlock(struct user_struct * user,u32 pages)196 static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
197 {
198 atomic_long_sub(pages, &user->locked_vm);
199 }
200
bpf_map_init_memlock(struct bpf_map * map)201 static int bpf_map_init_memlock(struct bpf_map *map)
202 {
203 struct user_struct *user = get_current_user();
204 int ret;
205
206 ret = bpf_charge_memlock(user, map->pages);
207 if (ret) {
208 free_uid(user);
209 return ret;
210 }
211 map->user = user;
212 return ret;
213 }
214
bpf_map_release_memlock(struct bpf_map * map)215 static void bpf_map_release_memlock(struct bpf_map *map)
216 {
217 struct user_struct *user = map->user;
218 bpf_uncharge_memlock(user, map->pages);
219 free_uid(user);
220 }
221
bpf_map_charge_memlock(struct bpf_map * map,u32 pages)222 int bpf_map_charge_memlock(struct bpf_map *map, u32 pages)
223 {
224 int ret;
225
226 ret = bpf_charge_memlock(map->user, pages);
227 if (ret)
228 return ret;
229 map->pages += pages;
230 return ret;
231 }
232
bpf_map_uncharge_memlock(struct bpf_map * map,u32 pages)233 void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages)
234 {
235 bpf_uncharge_memlock(map->user, pages);
236 map->pages -= pages;
237 }
238
bpf_map_alloc_id(struct bpf_map * map)239 static int bpf_map_alloc_id(struct bpf_map *map)
240 {
241 int id;
242
243 idr_preload(GFP_KERNEL);
244 spin_lock_bh(&map_idr_lock);
245 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
246 if (id > 0)
247 map->id = id;
248 spin_unlock_bh(&map_idr_lock);
249 idr_preload_end();
250
251 if (WARN_ON_ONCE(!id))
252 return -ENOSPC;
253
254 return id > 0 ? 0 : id;
255 }
256
bpf_map_free_id(struct bpf_map * map,bool do_idr_lock)257 void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
258 {
259 unsigned long flags;
260
261 /* Offloaded maps are removed from the IDR store when their device
262 * disappears - even if someone holds an fd to them they are unusable,
263 * the memory is gone, all ops will fail; they are simply waiting for
264 * refcnt to drop to be freed.
265 */
266 if (!map->id)
267 return;
268
269 if (do_idr_lock)
270 spin_lock_irqsave(&map_idr_lock, flags);
271 else
272 __acquire(&map_idr_lock);
273
274 idr_remove(&map_idr, map->id);
275 map->id = 0;
276
277 if (do_idr_lock)
278 spin_unlock_irqrestore(&map_idr_lock, flags);
279 else
280 __release(&map_idr_lock);
281 }
282
283 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)284 static void bpf_map_free_deferred(struct work_struct *work)
285 {
286 struct bpf_map *map = container_of(work, struct bpf_map, work);
287
288 bpf_map_release_memlock(map);
289 security_bpf_map_free(map);
290 /* implementation dependent freeing */
291 map->ops->map_free(map);
292 }
293
bpf_map_put_uref(struct bpf_map * map)294 static void bpf_map_put_uref(struct bpf_map *map)
295 {
296 if (atomic_dec_and_test(&map->usercnt)) {
297 if (map->ops->map_release_uref)
298 map->ops->map_release_uref(map);
299 }
300 }
301
302 /* decrement map refcnt and schedule it for freeing via workqueue
303 * (unrelying map implementation ops->map_free() might sleep)
304 */
__bpf_map_put(struct bpf_map * map,bool do_idr_lock)305 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
306 {
307 if (atomic_dec_and_test(&map->refcnt)) {
308 /* bpf_map_free_id() must be called first */
309 bpf_map_free_id(map, do_idr_lock);
310 btf_put(map->btf);
311 INIT_WORK(&map->work, bpf_map_free_deferred);
312 schedule_work(&map->work);
313 }
314 }
315
bpf_map_put(struct bpf_map * map)316 void bpf_map_put(struct bpf_map *map)
317 {
318 __bpf_map_put(map, true);
319 }
320 EXPORT_SYMBOL_GPL(bpf_map_put);
321
bpf_map_put_with_uref(struct bpf_map * map)322 void bpf_map_put_with_uref(struct bpf_map *map)
323 {
324 bpf_map_put_uref(map);
325 bpf_map_put(map);
326 }
327
bpf_map_release(struct inode * inode,struct file * filp)328 static int bpf_map_release(struct inode *inode, struct file *filp)
329 {
330 struct bpf_map *map = filp->private_data;
331
332 if (map->ops->map_release)
333 map->ops->map_release(map, filp);
334
335 bpf_map_put_with_uref(map);
336 return 0;
337 }
338
339 #ifdef CONFIG_PROC_FS
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)340 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
341 {
342 const struct bpf_map *map = filp->private_data;
343 const struct bpf_array *array;
344 u32 owner_prog_type = 0;
345 u32 owner_jited = 0;
346
347 if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
348 array = container_of(map, struct bpf_array, map);
349 owner_prog_type = array->owner_prog_type;
350 owner_jited = array->owner_jited;
351 }
352
353 seq_printf(m,
354 "map_type:\t%u\n"
355 "key_size:\t%u\n"
356 "value_size:\t%u\n"
357 "max_entries:\t%u\n"
358 "map_flags:\t%#x\n"
359 "memlock:\t%llu\n"
360 "map_id:\t%u\n",
361 map->map_type,
362 map->key_size,
363 map->value_size,
364 map->max_entries,
365 map->map_flags,
366 map->pages * 1ULL << PAGE_SHIFT,
367 map->id);
368
369 if (owner_prog_type) {
370 seq_printf(m, "owner_prog_type:\t%u\n",
371 owner_prog_type);
372 seq_printf(m, "owner_jited:\t%u\n",
373 owner_jited);
374 }
375 }
376 #endif
377
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)378 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
379 loff_t *ppos)
380 {
381 /* We need this handler such that alloc_file() enables
382 * f_mode with FMODE_CAN_READ.
383 */
384 return -EINVAL;
385 }
386
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)387 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
388 size_t siz, loff_t *ppos)
389 {
390 /* We need this handler such that alloc_file() enables
391 * f_mode with FMODE_CAN_WRITE.
392 */
393 return -EINVAL;
394 }
395
396 const struct file_operations bpf_map_fops = {
397 #ifdef CONFIG_PROC_FS
398 .show_fdinfo = bpf_map_show_fdinfo,
399 #endif
400 .release = bpf_map_release,
401 .read = bpf_dummy_read,
402 .write = bpf_dummy_write,
403 };
404
bpf_map_new_fd(struct bpf_map * map,int flags)405 int bpf_map_new_fd(struct bpf_map *map, int flags)
406 {
407 int ret;
408
409 ret = security_bpf_map(map, OPEN_FMODE(flags));
410 if (ret < 0)
411 return ret;
412
413 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
414 flags | O_CLOEXEC);
415 }
416
bpf_get_file_flag(int flags)417 int bpf_get_file_flag(int flags)
418 {
419 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
420 return -EINVAL;
421 if (flags & BPF_F_RDONLY)
422 return O_RDONLY;
423 if (flags & BPF_F_WRONLY)
424 return O_WRONLY;
425 return O_RDWR;
426 }
427
428 /* helper macro to check that unused fields 'union bpf_attr' are zero */
429 #define CHECK_ATTR(CMD) \
430 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
431 sizeof(attr->CMD##_LAST_FIELD), 0, \
432 sizeof(*attr) - \
433 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
434 sizeof(attr->CMD##_LAST_FIELD)) != NULL
435
436 /* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes.
437 * Return 0 on success and < 0 on error.
438 */
bpf_obj_name_cpy(char * dst,const char * src)439 static int bpf_obj_name_cpy(char *dst, const char *src)
440 {
441 const char *end = src + BPF_OBJ_NAME_LEN;
442
443 memset(dst, 0, BPF_OBJ_NAME_LEN);
444
445 /* Copy all isalnum() and '_' char */
446 while (src < end && *src) {
447 if (!isalnum(*src) && *src != '_')
448 return -EINVAL;
449 *dst++ = *src++;
450 }
451
452 /* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */
453 if (src == end)
454 return -EINVAL;
455
456 return 0;
457 }
458
map_check_no_btf(const struct bpf_map * map,const struct btf_type * key_type,const struct btf_type * value_type)459 int map_check_no_btf(const struct bpf_map *map,
460 const struct btf_type *key_type,
461 const struct btf_type *value_type)
462 {
463 return -ENOTSUPP;
464 }
465
map_check_btf(const struct bpf_map * map,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)466 static int map_check_btf(const struct bpf_map *map, const struct btf *btf,
467 u32 btf_key_id, u32 btf_value_id)
468 {
469 const struct btf_type *key_type, *value_type;
470 u32 key_size, value_size;
471 int ret = 0;
472
473 key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
474 if (!key_type || key_size != map->key_size)
475 return -EINVAL;
476
477 value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
478 if (!value_type || value_size != map->value_size)
479 return -EINVAL;
480
481 if (map->ops->map_check_btf)
482 ret = map->ops->map_check_btf(map, key_type, value_type);
483
484 return ret;
485 }
486
487 #define BPF_MAP_CREATE_LAST_FIELD btf_value_type_id
488 /* called via syscall */
map_create(union bpf_attr * attr)489 static int map_create(union bpf_attr *attr)
490 {
491 int numa_node = bpf_map_attr_numa_node(attr);
492 struct bpf_map *map;
493 int f_flags;
494 int err;
495
496 err = CHECK_ATTR(BPF_MAP_CREATE);
497 if (err)
498 return -EINVAL;
499
500 f_flags = bpf_get_file_flag(attr->map_flags);
501 if (f_flags < 0)
502 return f_flags;
503
504 if (numa_node != NUMA_NO_NODE &&
505 ((unsigned int)numa_node >= nr_node_ids ||
506 !node_online(numa_node)))
507 return -EINVAL;
508
509 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
510 map = find_and_alloc_map(attr);
511 if (IS_ERR(map))
512 return PTR_ERR(map);
513
514 err = bpf_obj_name_cpy(map->name, attr->map_name);
515 if (err)
516 goto free_map_nouncharge;
517
518 atomic_set(&map->refcnt, 1);
519 atomic_set(&map->usercnt, 1);
520
521 if (attr->btf_key_type_id || attr->btf_value_type_id) {
522 struct btf *btf;
523
524 if (!attr->btf_key_type_id || !attr->btf_value_type_id) {
525 err = -EINVAL;
526 goto free_map_nouncharge;
527 }
528
529 btf = btf_get_by_fd(attr->btf_fd);
530 if (IS_ERR(btf)) {
531 err = PTR_ERR(btf);
532 goto free_map_nouncharge;
533 }
534
535 err = map_check_btf(map, btf, attr->btf_key_type_id,
536 attr->btf_value_type_id);
537 if (err) {
538 btf_put(btf);
539 goto free_map_nouncharge;
540 }
541
542 map->btf = btf;
543 map->btf_key_type_id = attr->btf_key_type_id;
544 map->btf_value_type_id = attr->btf_value_type_id;
545 }
546
547 err = security_bpf_map_alloc(map);
548 if (err)
549 goto free_map_nouncharge;
550
551 err = bpf_map_init_memlock(map);
552 if (err)
553 goto free_map_sec;
554
555 err = bpf_map_alloc_id(map);
556 if (err)
557 goto free_map;
558
559 err = bpf_map_new_fd(map, f_flags);
560 if (err < 0) {
561 /* failed to allocate fd.
562 * bpf_map_put() is needed because the above
563 * bpf_map_alloc_id() has published the map
564 * to the userspace and the userspace may
565 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
566 */
567 bpf_map_put(map);
568 return err;
569 }
570
571 return err;
572
573 free_map:
574 bpf_map_release_memlock(map);
575 free_map_sec:
576 security_bpf_map_free(map);
577 free_map_nouncharge:
578 btf_put(map->btf);
579 map->ops->map_free(map);
580 return err;
581 }
582
583 /* if error is returned, fd is released.
584 * On success caller should complete fd access with matching fdput()
585 */
__bpf_map_get(struct fd f)586 struct bpf_map *__bpf_map_get(struct fd f)
587 {
588 if (!f.file)
589 return ERR_PTR(-EBADF);
590 if (f.file->f_op != &bpf_map_fops) {
591 fdput(f);
592 return ERR_PTR(-EINVAL);
593 }
594
595 return f.file->private_data;
596 }
597
598 /* prog's and map's refcnt limit */
599 #define BPF_MAX_REFCNT 32768
600
bpf_map_inc(struct bpf_map * map,bool uref)601 struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
602 {
603 if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
604 atomic_dec(&map->refcnt);
605 return ERR_PTR(-EBUSY);
606 }
607 if (uref)
608 atomic_inc(&map->usercnt);
609 return map;
610 }
611 EXPORT_SYMBOL_GPL(bpf_map_inc);
612
bpf_map_get_with_uref(u32 ufd)613 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
614 {
615 struct fd f = fdget(ufd);
616 struct bpf_map *map;
617
618 map = __bpf_map_get(f);
619 if (IS_ERR(map))
620 return map;
621
622 map = bpf_map_inc(map, true);
623 fdput(f);
624
625 return map;
626 }
627
628 /* map_idr_lock should have been held */
bpf_map_inc_not_zero(struct bpf_map * map,bool uref)629 static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map,
630 bool uref)
631 {
632 int refold;
633
634 refold = atomic_fetch_add_unless(&map->refcnt, 1, 0);
635
636 if (refold >= BPF_MAX_REFCNT) {
637 __bpf_map_put(map, false);
638 return ERR_PTR(-EBUSY);
639 }
640
641 if (!refold)
642 return ERR_PTR(-ENOENT);
643
644 if (uref)
645 atomic_inc(&map->usercnt);
646
647 return map;
648 }
649
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)650 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
651 {
652 return -ENOTSUPP;
653 }
654
655 /* last field in 'union bpf_attr' used by this command */
656 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
657
map_lookup_elem(union bpf_attr * attr)658 static int map_lookup_elem(union bpf_attr *attr)
659 {
660 void __user *ukey = u64_to_user_ptr(attr->key);
661 void __user *uvalue = u64_to_user_ptr(attr->value);
662 int ufd = attr->map_fd;
663 struct bpf_map *map;
664 void *key, *value, *ptr;
665 u32 value_size;
666 struct fd f;
667 int err;
668
669 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
670 return -EINVAL;
671
672 f = fdget(ufd);
673 map = __bpf_map_get(f);
674 if (IS_ERR(map))
675 return PTR_ERR(map);
676
677 if (!(f.file->f_mode & FMODE_CAN_READ)) {
678 err = -EPERM;
679 goto err_put;
680 }
681
682 key = memdup_user(ukey, map->key_size);
683 if (IS_ERR(key)) {
684 err = PTR_ERR(key);
685 goto err_put;
686 }
687
688 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
689 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
690 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
691 value_size = round_up(map->value_size, 8) * num_possible_cpus();
692 else if (IS_FD_MAP(map))
693 value_size = sizeof(u32);
694 else
695 value_size = map->value_size;
696
697 err = -ENOMEM;
698 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
699 if (!value)
700 goto free_key;
701
702 if (bpf_map_is_dev_bound(map)) {
703 err = bpf_map_offload_lookup_elem(map, key, value);
704 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
705 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
706 err = bpf_percpu_hash_copy(map, key, value);
707 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
708 err = bpf_percpu_array_copy(map, key, value);
709 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
710 err = bpf_stackmap_copy(map, key, value);
711 } else if (IS_FD_ARRAY(map)) {
712 err = bpf_fd_array_map_lookup_elem(map, key, value);
713 } else if (IS_FD_HASH(map)) {
714 err = bpf_fd_htab_map_lookup_elem(map, key, value);
715 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
716 err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
717 } else {
718 rcu_read_lock();
719 ptr = map->ops->map_lookup_elem(map, key);
720 if (ptr)
721 memcpy(value, ptr, value_size);
722 rcu_read_unlock();
723 err = ptr ? 0 : -ENOENT;
724 }
725
726 if (err)
727 goto free_value;
728
729 err = -EFAULT;
730 if (copy_to_user(uvalue, value, value_size) != 0)
731 goto free_value;
732
733 err = 0;
734
735 free_value:
736 kfree(value);
737 free_key:
738 kfree(key);
739 err_put:
740 fdput(f);
741 return err;
742 }
743
744 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
745
map_update_elem(union bpf_attr * attr)746 static int map_update_elem(union bpf_attr *attr)
747 {
748 void __user *ukey = u64_to_user_ptr(attr->key);
749 void __user *uvalue = u64_to_user_ptr(attr->value);
750 int ufd = attr->map_fd;
751 struct bpf_map *map;
752 void *key, *value;
753 u32 value_size;
754 struct fd f;
755 int err;
756
757 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
758 return -EINVAL;
759
760 f = fdget(ufd);
761 map = __bpf_map_get(f);
762 if (IS_ERR(map))
763 return PTR_ERR(map);
764
765 if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
766 err = -EPERM;
767 goto err_put;
768 }
769
770 key = memdup_user(ukey, map->key_size);
771 if (IS_ERR(key)) {
772 err = PTR_ERR(key);
773 goto err_put;
774 }
775
776 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
777 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
778 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
779 value_size = round_up(map->value_size, 8) * num_possible_cpus();
780 else
781 value_size = map->value_size;
782
783 err = -ENOMEM;
784 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
785 if (!value)
786 goto free_key;
787
788 err = -EFAULT;
789 if (copy_from_user(value, uvalue, value_size) != 0)
790 goto free_value;
791
792 /* Need to create a kthread, thus must support schedule */
793 if (bpf_map_is_dev_bound(map)) {
794 err = bpf_map_offload_update_elem(map, key, value, attr->flags);
795 goto out;
796 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
797 map->map_type == BPF_MAP_TYPE_SOCKHASH ||
798 map->map_type == BPF_MAP_TYPE_SOCKMAP) {
799 err = map->ops->map_update_elem(map, key, value, attr->flags);
800 goto out;
801 }
802
803 /* must increment bpf_prog_active to avoid kprobe+bpf triggering from
804 * inside bpf map update or delete otherwise deadlocks are possible
805 */
806 preempt_disable();
807 __this_cpu_inc(bpf_prog_active);
808 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
809 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
810 err = bpf_percpu_hash_update(map, key, value, attr->flags);
811 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
812 err = bpf_percpu_array_update(map, key, value, attr->flags);
813 } else if (IS_FD_ARRAY(map)) {
814 rcu_read_lock();
815 err = bpf_fd_array_map_update_elem(map, f.file, key, value,
816 attr->flags);
817 rcu_read_unlock();
818 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
819 rcu_read_lock();
820 err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
821 attr->flags);
822 rcu_read_unlock();
823 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
824 /* rcu_read_lock() is not needed */
825 err = bpf_fd_reuseport_array_update_elem(map, key, value,
826 attr->flags);
827 } else {
828 rcu_read_lock();
829 err = map->ops->map_update_elem(map, key, value, attr->flags);
830 rcu_read_unlock();
831 }
832 __this_cpu_dec(bpf_prog_active);
833 preempt_enable();
834 out:
835 free_value:
836 kfree(value);
837 free_key:
838 kfree(key);
839 err_put:
840 fdput(f);
841 return err;
842 }
843
844 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
845
map_delete_elem(union bpf_attr * attr)846 static int map_delete_elem(union bpf_attr *attr)
847 {
848 void __user *ukey = u64_to_user_ptr(attr->key);
849 int ufd = attr->map_fd;
850 struct bpf_map *map;
851 struct fd f;
852 void *key;
853 int err;
854
855 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
856 return -EINVAL;
857
858 f = fdget(ufd);
859 map = __bpf_map_get(f);
860 if (IS_ERR(map))
861 return PTR_ERR(map);
862
863 if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
864 err = -EPERM;
865 goto err_put;
866 }
867
868 key = memdup_user(ukey, map->key_size);
869 if (IS_ERR(key)) {
870 err = PTR_ERR(key);
871 goto err_put;
872 }
873
874 if (bpf_map_is_dev_bound(map)) {
875 err = bpf_map_offload_delete_elem(map, key);
876 goto out;
877 }
878
879 preempt_disable();
880 __this_cpu_inc(bpf_prog_active);
881 rcu_read_lock();
882 err = map->ops->map_delete_elem(map, key);
883 rcu_read_unlock();
884 __this_cpu_dec(bpf_prog_active);
885 preempt_enable();
886 out:
887 kfree(key);
888 err_put:
889 fdput(f);
890 return err;
891 }
892
893 /* last field in 'union bpf_attr' used by this command */
894 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
895
map_get_next_key(union bpf_attr * attr)896 static int map_get_next_key(union bpf_attr *attr)
897 {
898 void __user *ukey = u64_to_user_ptr(attr->key);
899 void __user *unext_key = u64_to_user_ptr(attr->next_key);
900 int ufd = attr->map_fd;
901 struct bpf_map *map;
902 void *key, *next_key;
903 struct fd f;
904 int err;
905
906 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
907 return -EINVAL;
908
909 f = fdget(ufd);
910 map = __bpf_map_get(f);
911 if (IS_ERR(map))
912 return PTR_ERR(map);
913
914 if (!(f.file->f_mode & FMODE_CAN_READ)) {
915 err = -EPERM;
916 goto err_put;
917 }
918
919 if (ukey) {
920 key = memdup_user(ukey, map->key_size);
921 if (IS_ERR(key)) {
922 err = PTR_ERR(key);
923 goto err_put;
924 }
925 } else {
926 key = NULL;
927 }
928
929 err = -ENOMEM;
930 next_key = kmalloc(map->key_size, GFP_USER);
931 if (!next_key)
932 goto free_key;
933
934 if (bpf_map_is_dev_bound(map)) {
935 err = bpf_map_offload_get_next_key(map, key, next_key);
936 goto out;
937 }
938
939 rcu_read_lock();
940 err = map->ops->map_get_next_key(map, key, next_key);
941 rcu_read_unlock();
942 out:
943 if (err)
944 goto free_next_key;
945
946 err = -EFAULT;
947 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
948 goto free_next_key;
949
950 err = 0;
951
952 free_next_key:
953 kfree(next_key);
954 free_key:
955 kfree(key);
956 err_put:
957 fdput(f);
958 return err;
959 }
960
961 static const struct bpf_prog_ops * const bpf_prog_types[] = {
962 #define BPF_PROG_TYPE(_id, _name) \
963 [_id] = & _name ## _prog_ops,
964 #define BPF_MAP_TYPE(_id, _ops)
965 #include <linux/bpf_types.h>
966 #undef BPF_PROG_TYPE
967 #undef BPF_MAP_TYPE
968 };
969
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)970 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
971 {
972 const struct bpf_prog_ops *ops;
973
974 if (type >= ARRAY_SIZE(bpf_prog_types))
975 return -EINVAL;
976 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
977 ops = bpf_prog_types[type];
978 if (!ops)
979 return -EINVAL;
980
981 if (!bpf_prog_is_dev_bound(prog->aux))
982 prog->aux->ops = ops;
983 else
984 prog->aux->ops = &bpf_offload_prog_ops;
985 prog->type = type;
986 return 0;
987 }
988
989 /* drop refcnt on maps used by eBPF program and free auxilary data */
free_used_maps(struct bpf_prog_aux * aux)990 static void free_used_maps(struct bpf_prog_aux *aux)
991 {
992 int i;
993
994 if (aux->cgroup_storage)
995 bpf_cgroup_storage_release(aux->prog, aux->cgroup_storage);
996
997 for (i = 0; i < aux->used_map_cnt; i++)
998 bpf_map_put(aux->used_maps[i]);
999
1000 kfree(aux->used_maps);
1001 }
1002
__bpf_prog_charge(struct user_struct * user,u32 pages)1003 int __bpf_prog_charge(struct user_struct *user, u32 pages)
1004 {
1005 unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1006 unsigned long user_bufs;
1007
1008 if (user) {
1009 user_bufs = atomic_long_add_return(pages, &user->locked_vm);
1010 if (user_bufs > memlock_limit) {
1011 atomic_long_sub(pages, &user->locked_vm);
1012 return -EPERM;
1013 }
1014 }
1015
1016 return 0;
1017 }
1018
__bpf_prog_uncharge(struct user_struct * user,u32 pages)1019 void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
1020 {
1021 if (user)
1022 atomic_long_sub(pages, &user->locked_vm);
1023 }
1024
bpf_prog_charge_memlock(struct bpf_prog * prog)1025 static int bpf_prog_charge_memlock(struct bpf_prog *prog)
1026 {
1027 struct user_struct *user = get_current_user();
1028 int ret;
1029
1030 ret = __bpf_prog_charge(user, prog->pages);
1031 if (ret) {
1032 free_uid(user);
1033 return ret;
1034 }
1035
1036 prog->aux->user = user;
1037 return 0;
1038 }
1039
bpf_prog_uncharge_memlock(struct bpf_prog * prog)1040 static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
1041 {
1042 struct user_struct *user = prog->aux->user;
1043
1044 __bpf_prog_uncharge(user, prog->pages);
1045 free_uid(user);
1046 }
1047
bpf_prog_alloc_id(struct bpf_prog * prog)1048 static int bpf_prog_alloc_id(struct bpf_prog *prog)
1049 {
1050 int id;
1051
1052 idr_preload(GFP_KERNEL);
1053 spin_lock_bh(&prog_idr_lock);
1054 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
1055 if (id > 0)
1056 prog->aux->id = id;
1057 spin_unlock_bh(&prog_idr_lock);
1058 idr_preload_end();
1059
1060 /* id is in [1, INT_MAX) */
1061 if (WARN_ON_ONCE(!id))
1062 return -ENOSPC;
1063
1064 return id > 0 ? 0 : id;
1065 }
1066
bpf_prog_free_id(struct bpf_prog * prog,bool do_idr_lock)1067 void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
1068 {
1069 /* cBPF to eBPF migrations are currently not in the idr store.
1070 * Offloaded programs are removed from the store when their device
1071 * disappears - even if someone grabs an fd to them they are unusable,
1072 * simply waiting for refcnt to drop to be freed.
1073 */
1074 if (!prog->aux->id)
1075 return;
1076
1077 if (do_idr_lock)
1078 spin_lock_bh(&prog_idr_lock);
1079 else
1080 __acquire(&prog_idr_lock);
1081
1082 idr_remove(&prog_idr, prog->aux->id);
1083 prog->aux->id = 0;
1084
1085 if (do_idr_lock)
1086 spin_unlock_bh(&prog_idr_lock);
1087 else
1088 __release(&prog_idr_lock);
1089 }
1090
__bpf_prog_put_rcu(struct rcu_head * rcu)1091 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
1092 {
1093 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
1094
1095 free_used_maps(aux);
1096 bpf_prog_uncharge_memlock(aux->prog);
1097 security_bpf_prog_free(aux);
1098 bpf_prog_free(aux->prog);
1099 }
1100
__bpf_prog_put(struct bpf_prog * prog,bool do_idr_lock)1101 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
1102 {
1103 if (atomic_dec_and_test(&prog->aux->refcnt)) {
1104 /* bpf_prog_free_id() must be called first */
1105 bpf_prog_free_id(prog, do_idr_lock);
1106 bpf_prog_kallsyms_del_all(prog);
1107
1108 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
1109 }
1110 }
1111
bpf_prog_put(struct bpf_prog * prog)1112 void bpf_prog_put(struct bpf_prog *prog)
1113 {
1114 __bpf_prog_put(prog, true);
1115 }
1116 EXPORT_SYMBOL_GPL(bpf_prog_put);
1117
bpf_prog_release(struct inode * inode,struct file * filp)1118 static int bpf_prog_release(struct inode *inode, struct file *filp)
1119 {
1120 struct bpf_prog *prog = filp->private_data;
1121
1122 bpf_prog_put(prog);
1123 return 0;
1124 }
1125
1126 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)1127 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
1128 {
1129 const struct bpf_prog *prog = filp->private_data;
1130 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
1131
1132 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
1133 seq_printf(m,
1134 "prog_type:\t%u\n"
1135 "prog_jited:\t%u\n"
1136 "prog_tag:\t%s\n"
1137 "memlock:\t%llu\n"
1138 "prog_id:\t%u\n",
1139 prog->type,
1140 prog->jited,
1141 prog_tag,
1142 prog->pages * 1ULL << PAGE_SHIFT,
1143 prog->aux->id);
1144 }
1145 #endif
1146
1147 const struct file_operations bpf_prog_fops = {
1148 #ifdef CONFIG_PROC_FS
1149 .show_fdinfo = bpf_prog_show_fdinfo,
1150 #endif
1151 .release = bpf_prog_release,
1152 .read = bpf_dummy_read,
1153 .write = bpf_dummy_write,
1154 };
1155
bpf_prog_new_fd(struct bpf_prog * prog)1156 int bpf_prog_new_fd(struct bpf_prog *prog)
1157 {
1158 int ret;
1159
1160 ret = security_bpf_prog(prog);
1161 if (ret < 0)
1162 return ret;
1163
1164 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
1165 O_RDWR | O_CLOEXEC);
1166 }
1167
____bpf_prog_get(struct fd f)1168 static struct bpf_prog *____bpf_prog_get(struct fd f)
1169 {
1170 if (!f.file)
1171 return ERR_PTR(-EBADF);
1172 if (f.file->f_op != &bpf_prog_fops) {
1173 fdput(f);
1174 return ERR_PTR(-EINVAL);
1175 }
1176
1177 return f.file->private_data;
1178 }
1179
bpf_prog_add(struct bpf_prog * prog,int i)1180 struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
1181 {
1182 if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
1183 atomic_sub(i, &prog->aux->refcnt);
1184 return ERR_PTR(-EBUSY);
1185 }
1186 return prog;
1187 }
1188 EXPORT_SYMBOL_GPL(bpf_prog_add);
1189
bpf_prog_sub(struct bpf_prog * prog,int i)1190 void bpf_prog_sub(struct bpf_prog *prog, int i)
1191 {
1192 /* Only to be used for undoing previous bpf_prog_add() in some
1193 * error path. We still know that another entity in our call
1194 * path holds a reference to the program, thus atomic_sub() can
1195 * be safely used in such cases!
1196 */
1197 WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
1198 }
1199 EXPORT_SYMBOL_GPL(bpf_prog_sub);
1200
bpf_prog_inc(struct bpf_prog * prog)1201 struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
1202 {
1203 return bpf_prog_add(prog, 1);
1204 }
1205 EXPORT_SYMBOL_GPL(bpf_prog_inc);
1206
1207 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)1208 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
1209 {
1210 int refold;
1211
1212 refold = atomic_fetch_add_unless(&prog->aux->refcnt, 1, 0);
1213
1214 if (refold >= BPF_MAX_REFCNT) {
1215 __bpf_prog_put(prog, false);
1216 return ERR_PTR(-EBUSY);
1217 }
1218
1219 if (!refold)
1220 return ERR_PTR(-ENOENT);
1221
1222 return prog;
1223 }
1224 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
1225
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)1226 bool bpf_prog_get_ok(struct bpf_prog *prog,
1227 enum bpf_prog_type *attach_type, bool attach_drv)
1228 {
1229 /* not an attachment, just a refcount inc, always allow */
1230 if (!attach_type)
1231 return true;
1232
1233 if (prog->type != *attach_type)
1234 return false;
1235 if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
1236 return false;
1237
1238 return true;
1239 }
1240
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)1241 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
1242 bool attach_drv)
1243 {
1244 struct fd f = fdget(ufd);
1245 struct bpf_prog *prog;
1246
1247 prog = ____bpf_prog_get(f);
1248 if (IS_ERR(prog))
1249 return prog;
1250 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
1251 prog = ERR_PTR(-EINVAL);
1252 goto out;
1253 }
1254
1255 prog = bpf_prog_inc(prog);
1256 out:
1257 fdput(f);
1258 return prog;
1259 }
1260
bpf_prog_get(u32 ufd)1261 struct bpf_prog *bpf_prog_get(u32 ufd)
1262 {
1263 return __bpf_prog_get(ufd, NULL, false);
1264 }
1265
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)1266 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
1267 bool attach_drv)
1268 {
1269 return __bpf_prog_get(ufd, &type, attach_drv);
1270 }
1271 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
1272
1273 /* Initially all BPF programs could be loaded w/o specifying
1274 * expected_attach_type. Later for some of them specifying expected_attach_type
1275 * at load time became required so that program could be validated properly.
1276 * Programs of types that are allowed to be loaded both w/ and w/o (for
1277 * backward compatibility) expected_attach_type, should have the default attach
1278 * type assigned to expected_attach_type for the latter case, so that it can be
1279 * validated later at attach time.
1280 *
1281 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
1282 * prog type requires it but has some attach types that have to be backward
1283 * compatible.
1284 */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)1285 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
1286 {
1287 switch (attr->prog_type) {
1288 case BPF_PROG_TYPE_CGROUP_SOCK:
1289 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
1290 * exist so checking for non-zero is the way to go here.
1291 */
1292 if (!attr->expected_attach_type)
1293 attr->expected_attach_type =
1294 BPF_CGROUP_INET_SOCK_CREATE;
1295 break;
1296 }
1297 }
1298
1299 static int
bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,enum bpf_attach_type expected_attach_type)1300 bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
1301 enum bpf_attach_type expected_attach_type)
1302 {
1303 switch (prog_type) {
1304 case BPF_PROG_TYPE_CGROUP_SOCK:
1305 switch (expected_attach_type) {
1306 case BPF_CGROUP_INET_SOCK_CREATE:
1307 case BPF_CGROUP_INET4_POST_BIND:
1308 case BPF_CGROUP_INET6_POST_BIND:
1309 return 0;
1310 default:
1311 return -EINVAL;
1312 }
1313 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
1314 switch (expected_attach_type) {
1315 case BPF_CGROUP_INET4_BIND:
1316 case BPF_CGROUP_INET6_BIND:
1317 case BPF_CGROUP_INET4_CONNECT:
1318 case BPF_CGROUP_INET6_CONNECT:
1319 case BPF_CGROUP_UDP4_SENDMSG:
1320 case BPF_CGROUP_UDP6_SENDMSG:
1321 return 0;
1322 default:
1323 return -EINVAL;
1324 }
1325 default:
1326 return 0;
1327 }
1328 }
1329
1330 /* last field in 'union bpf_attr' used by this command */
1331 #define BPF_PROG_LOAD_LAST_FIELD expected_attach_type
1332
bpf_prog_load(union bpf_attr * attr)1333 static int bpf_prog_load(union bpf_attr *attr)
1334 {
1335 enum bpf_prog_type type = attr->prog_type;
1336 struct bpf_prog *prog;
1337 int err;
1338 char license[128];
1339 bool is_gpl;
1340
1341 if (CHECK_ATTR(BPF_PROG_LOAD))
1342 return -EINVAL;
1343
1344 if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
1345 return -EINVAL;
1346
1347 /* copy eBPF program license from user space */
1348 if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
1349 sizeof(license) - 1) < 0)
1350 return -EFAULT;
1351 license[sizeof(license) - 1] = 0;
1352
1353 /* eBPF programs must be GPL compatible to use GPL-ed functions */
1354 is_gpl = license_is_gpl_compatible(license);
1355
1356 if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
1357 return -E2BIG;
1358
1359 if (type == BPF_PROG_TYPE_KPROBE &&
1360 attr->kern_version != LINUX_VERSION_CODE)
1361 return -EINVAL;
1362
1363 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
1364 type != BPF_PROG_TYPE_CGROUP_SKB &&
1365 !capable(CAP_SYS_ADMIN))
1366 return -EPERM;
1367
1368 bpf_prog_load_fixup_attach_type(attr);
1369 if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type))
1370 return -EINVAL;
1371
1372 /* plain bpf_prog allocation */
1373 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
1374 if (!prog)
1375 return -ENOMEM;
1376
1377 prog->expected_attach_type = attr->expected_attach_type;
1378
1379 prog->aux->offload_requested = !!attr->prog_ifindex;
1380
1381 err = security_bpf_prog_alloc(prog->aux);
1382 if (err)
1383 goto free_prog_nouncharge;
1384
1385 err = bpf_prog_charge_memlock(prog);
1386 if (err)
1387 goto free_prog_sec;
1388
1389 prog->len = attr->insn_cnt;
1390
1391 err = -EFAULT;
1392 if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
1393 bpf_prog_insn_size(prog)) != 0)
1394 goto free_prog;
1395
1396 prog->orig_prog = NULL;
1397 prog->jited = 0;
1398
1399 atomic_set(&prog->aux->refcnt, 1);
1400 prog->gpl_compatible = is_gpl ? 1 : 0;
1401
1402 if (bpf_prog_is_dev_bound(prog->aux)) {
1403 err = bpf_prog_offload_init(prog, attr);
1404 if (err)
1405 goto free_prog;
1406 }
1407
1408 /* find program type: socket_filter vs tracing_filter */
1409 err = find_prog_type(type, prog);
1410 if (err < 0)
1411 goto free_prog;
1412
1413 prog->aux->load_time = ktime_get_boot_ns();
1414 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name);
1415 if (err)
1416 goto free_prog;
1417
1418 /* run eBPF verifier */
1419 err = bpf_check(&prog, attr);
1420 if (err < 0)
1421 goto free_used_maps;
1422
1423 prog = bpf_prog_select_runtime(prog, &err);
1424 if (err < 0)
1425 goto free_used_maps;
1426
1427 err = bpf_prog_alloc_id(prog);
1428 if (err)
1429 goto free_used_maps;
1430
1431 err = bpf_prog_new_fd(prog);
1432 if (err < 0) {
1433 /* failed to allocate fd.
1434 * bpf_prog_put() is needed because the above
1435 * bpf_prog_alloc_id() has published the prog
1436 * to the userspace and the userspace may
1437 * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
1438 */
1439 bpf_prog_put(prog);
1440 return err;
1441 }
1442
1443 bpf_prog_kallsyms_add(prog);
1444 return err;
1445
1446 free_used_maps:
1447 bpf_prog_kallsyms_del_subprogs(prog);
1448 free_used_maps(prog->aux);
1449 free_prog:
1450 bpf_prog_uncharge_memlock(prog);
1451 free_prog_sec:
1452 security_bpf_prog_free(prog->aux);
1453 free_prog_nouncharge:
1454 bpf_prog_free(prog);
1455 return err;
1456 }
1457
1458 #define BPF_OBJ_LAST_FIELD file_flags
1459
bpf_obj_pin(const union bpf_attr * attr)1460 static int bpf_obj_pin(const union bpf_attr *attr)
1461 {
1462 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
1463 return -EINVAL;
1464
1465 return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
1466 }
1467
bpf_obj_get(const union bpf_attr * attr)1468 static int bpf_obj_get(const union bpf_attr *attr)
1469 {
1470 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
1471 attr->file_flags & ~BPF_OBJ_FLAG_MASK)
1472 return -EINVAL;
1473
1474 return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
1475 attr->file_flags);
1476 }
1477
1478 struct bpf_raw_tracepoint {
1479 struct bpf_raw_event_map *btp;
1480 struct bpf_prog *prog;
1481 };
1482
bpf_raw_tracepoint_release(struct inode * inode,struct file * filp)1483 static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp)
1484 {
1485 struct bpf_raw_tracepoint *raw_tp = filp->private_data;
1486
1487 if (raw_tp->prog) {
1488 bpf_probe_unregister(raw_tp->btp, raw_tp->prog);
1489 bpf_prog_put(raw_tp->prog);
1490 }
1491 kfree(raw_tp);
1492 return 0;
1493 }
1494
1495 static const struct file_operations bpf_raw_tp_fops = {
1496 .release = bpf_raw_tracepoint_release,
1497 .read = bpf_dummy_read,
1498 .write = bpf_dummy_write,
1499 };
1500
1501 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
1502
bpf_raw_tracepoint_open(const union bpf_attr * attr)1503 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
1504 {
1505 struct bpf_raw_tracepoint *raw_tp;
1506 struct bpf_raw_event_map *btp;
1507 struct bpf_prog *prog;
1508 char tp_name[128];
1509 int tp_fd, err;
1510
1511 if (strncpy_from_user(tp_name, u64_to_user_ptr(attr->raw_tracepoint.name),
1512 sizeof(tp_name) - 1) < 0)
1513 return -EFAULT;
1514 tp_name[sizeof(tp_name) - 1] = 0;
1515
1516 btp = bpf_find_raw_tracepoint(tp_name);
1517 if (!btp)
1518 return -ENOENT;
1519
1520 raw_tp = kzalloc(sizeof(*raw_tp), GFP_USER);
1521 if (!raw_tp)
1522 return -ENOMEM;
1523 raw_tp->btp = btp;
1524
1525 prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd,
1526 BPF_PROG_TYPE_RAW_TRACEPOINT);
1527 if (IS_ERR(prog)) {
1528 err = PTR_ERR(prog);
1529 goto out_free_tp;
1530 }
1531
1532 err = bpf_probe_register(raw_tp->btp, prog);
1533 if (err)
1534 goto out_put_prog;
1535
1536 raw_tp->prog = prog;
1537 tp_fd = anon_inode_getfd("bpf-raw-tracepoint", &bpf_raw_tp_fops, raw_tp,
1538 O_CLOEXEC);
1539 if (tp_fd < 0) {
1540 bpf_probe_unregister(raw_tp->btp, prog);
1541 err = tp_fd;
1542 goto out_put_prog;
1543 }
1544 return tp_fd;
1545
1546 out_put_prog:
1547 bpf_prog_put(prog);
1548 out_free_tp:
1549 kfree(raw_tp);
1550 return err;
1551 }
1552
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)1553 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
1554 enum bpf_attach_type attach_type)
1555 {
1556 switch (prog->type) {
1557 case BPF_PROG_TYPE_CGROUP_SOCK:
1558 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
1559 return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
1560 default:
1561 return 0;
1562 }
1563 }
1564
1565 #define BPF_PROG_ATTACH_LAST_FIELD attach_flags
1566
1567 #define BPF_F_ATTACH_MASK \
1568 (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
1569
bpf_prog_attach(const union bpf_attr * attr)1570 static int bpf_prog_attach(const union bpf_attr *attr)
1571 {
1572 enum bpf_prog_type ptype;
1573 struct bpf_prog *prog;
1574 int ret;
1575
1576 if (!capable(CAP_NET_ADMIN))
1577 return -EPERM;
1578
1579 if (CHECK_ATTR(BPF_PROG_ATTACH))
1580 return -EINVAL;
1581
1582 if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
1583 return -EINVAL;
1584
1585 switch (attr->attach_type) {
1586 case BPF_CGROUP_INET_INGRESS:
1587 case BPF_CGROUP_INET_EGRESS:
1588 ptype = BPF_PROG_TYPE_CGROUP_SKB;
1589 break;
1590 case BPF_CGROUP_INET_SOCK_CREATE:
1591 case BPF_CGROUP_INET4_POST_BIND:
1592 case BPF_CGROUP_INET6_POST_BIND:
1593 ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1594 break;
1595 case BPF_CGROUP_INET4_BIND:
1596 case BPF_CGROUP_INET6_BIND:
1597 case BPF_CGROUP_INET4_CONNECT:
1598 case BPF_CGROUP_INET6_CONNECT:
1599 case BPF_CGROUP_UDP4_SENDMSG:
1600 case BPF_CGROUP_UDP6_SENDMSG:
1601 ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
1602 break;
1603 case BPF_CGROUP_SOCK_OPS:
1604 ptype = BPF_PROG_TYPE_SOCK_OPS;
1605 break;
1606 case BPF_CGROUP_DEVICE:
1607 ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1608 break;
1609 case BPF_SK_MSG_VERDICT:
1610 ptype = BPF_PROG_TYPE_SK_MSG;
1611 break;
1612 case BPF_SK_SKB_STREAM_PARSER:
1613 case BPF_SK_SKB_STREAM_VERDICT:
1614 ptype = BPF_PROG_TYPE_SK_SKB;
1615 break;
1616 case BPF_LIRC_MODE2:
1617 ptype = BPF_PROG_TYPE_LIRC_MODE2;
1618 break;
1619 default:
1620 return -EINVAL;
1621 }
1622
1623 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1624 if (IS_ERR(prog))
1625 return PTR_ERR(prog);
1626
1627 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
1628 bpf_prog_put(prog);
1629 return -EINVAL;
1630 }
1631
1632 switch (ptype) {
1633 case BPF_PROG_TYPE_SK_SKB:
1634 case BPF_PROG_TYPE_SK_MSG:
1635 ret = sockmap_get_from_fd(attr, ptype, prog);
1636 break;
1637 case BPF_PROG_TYPE_LIRC_MODE2:
1638 ret = lirc_prog_attach(attr, prog);
1639 break;
1640 default:
1641 ret = cgroup_bpf_prog_attach(attr, ptype, prog);
1642 }
1643
1644 if (ret)
1645 bpf_prog_put(prog);
1646 return ret;
1647 }
1648
1649 #define BPF_PROG_DETACH_LAST_FIELD attach_type
1650
bpf_prog_detach(const union bpf_attr * attr)1651 static int bpf_prog_detach(const union bpf_attr *attr)
1652 {
1653 enum bpf_prog_type ptype;
1654
1655 if (!capable(CAP_NET_ADMIN))
1656 return -EPERM;
1657
1658 if (CHECK_ATTR(BPF_PROG_DETACH))
1659 return -EINVAL;
1660
1661 switch (attr->attach_type) {
1662 case BPF_CGROUP_INET_INGRESS:
1663 case BPF_CGROUP_INET_EGRESS:
1664 ptype = BPF_PROG_TYPE_CGROUP_SKB;
1665 break;
1666 case BPF_CGROUP_INET_SOCK_CREATE:
1667 case BPF_CGROUP_INET4_POST_BIND:
1668 case BPF_CGROUP_INET6_POST_BIND:
1669 ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1670 break;
1671 case BPF_CGROUP_INET4_BIND:
1672 case BPF_CGROUP_INET6_BIND:
1673 case BPF_CGROUP_INET4_CONNECT:
1674 case BPF_CGROUP_INET6_CONNECT:
1675 case BPF_CGROUP_UDP4_SENDMSG:
1676 case BPF_CGROUP_UDP6_SENDMSG:
1677 ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
1678 break;
1679 case BPF_CGROUP_SOCK_OPS:
1680 ptype = BPF_PROG_TYPE_SOCK_OPS;
1681 break;
1682 case BPF_CGROUP_DEVICE:
1683 ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1684 break;
1685 case BPF_SK_MSG_VERDICT:
1686 return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, NULL);
1687 case BPF_SK_SKB_STREAM_PARSER:
1688 case BPF_SK_SKB_STREAM_VERDICT:
1689 return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, NULL);
1690 case BPF_LIRC_MODE2:
1691 return lirc_prog_detach(attr);
1692 default:
1693 return -EINVAL;
1694 }
1695
1696 return cgroup_bpf_prog_detach(attr, ptype);
1697 }
1698
1699 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
1700
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)1701 static int bpf_prog_query(const union bpf_attr *attr,
1702 union bpf_attr __user *uattr)
1703 {
1704 if (!capable(CAP_NET_ADMIN))
1705 return -EPERM;
1706 if (CHECK_ATTR(BPF_PROG_QUERY))
1707 return -EINVAL;
1708 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
1709 return -EINVAL;
1710
1711 switch (attr->query.attach_type) {
1712 case BPF_CGROUP_INET_INGRESS:
1713 case BPF_CGROUP_INET_EGRESS:
1714 case BPF_CGROUP_INET_SOCK_CREATE:
1715 case BPF_CGROUP_INET4_BIND:
1716 case BPF_CGROUP_INET6_BIND:
1717 case BPF_CGROUP_INET4_POST_BIND:
1718 case BPF_CGROUP_INET6_POST_BIND:
1719 case BPF_CGROUP_INET4_CONNECT:
1720 case BPF_CGROUP_INET6_CONNECT:
1721 case BPF_CGROUP_UDP4_SENDMSG:
1722 case BPF_CGROUP_UDP6_SENDMSG:
1723 case BPF_CGROUP_SOCK_OPS:
1724 case BPF_CGROUP_DEVICE:
1725 break;
1726 case BPF_LIRC_MODE2:
1727 return lirc_prog_query(attr, uattr);
1728 default:
1729 return -EINVAL;
1730 }
1731
1732 return cgroup_bpf_prog_query(attr, uattr);
1733 }
1734
1735 #define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
1736
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)1737 static int bpf_prog_test_run(const union bpf_attr *attr,
1738 union bpf_attr __user *uattr)
1739 {
1740 struct bpf_prog *prog;
1741 int ret = -ENOTSUPP;
1742
1743 if (!capable(CAP_SYS_ADMIN))
1744 return -EPERM;
1745 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
1746 return -EINVAL;
1747
1748 prog = bpf_prog_get(attr->test.prog_fd);
1749 if (IS_ERR(prog))
1750 return PTR_ERR(prog);
1751
1752 if (prog->aux->ops->test_run)
1753 ret = prog->aux->ops->test_run(prog, attr, uattr);
1754
1755 bpf_prog_put(prog);
1756 return ret;
1757 }
1758
1759 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
1760
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)1761 static int bpf_obj_get_next_id(const union bpf_attr *attr,
1762 union bpf_attr __user *uattr,
1763 struct idr *idr,
1764 spinlock_t *lock)
1765 {
1766 u32 next_id = attr->start_id;
1767 int err = 0;
1768
1769 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
1770 return -EINVAL;
1771
1772 if (!capable(CAP_SYS_ADMIN))
1773 return -EPERM;
1774
1775 next_id++;
1776 spin_lock_bh(lock);
1777 if (!idr_get_next(idr, &next_id))
1778 err = -ENOENT;
1779 spin_unlock_bh(lock);
1780
1781 if (!err)
1782 err = put_user(next_id, &uattr->next_id);
1783
1784 return err;
1785 }
1786
1787 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
1788
bpf_prog_get_fd_by_id(const union bpf_attr * attr)1789 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
1790 {
1791 struct bpf_prog *prog;
1792 u32 id = attr->prog_id;
1793 int fd;
1794
1795 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
1796 return -EINVAL;
1797
1798 if (!capable(CAP_SYS_ADMIN))
1799 return -EPERM;
1800
1801 spin_lock_bh(&prog_idr_lock);
1802 prog = idr_find(&prog_idr, id);
1803 if (prog)
1804 prog = bpf_prog_inc_not_zero(prog);
1805 else
1806 prog = ERR_PTR(-ENOENT);
1807 spin_unlock_bh(&prog_idr_lock);
1808
1809 if (IS_ERR(prog))
1810 return PTR_ERR(prog);
1811
1812 fd = bpf_prog_new_fd(prog);
1813 if (fd < 0)
1814 bpf_prog_put(prog);
1815
1816 return fd;
1817 }
1818
1819 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
1820
bpf_map_get_fd_by_id(const union bpf_attr * attr)1821 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
1822 {
1823 struct bpf_map *map;
1824 u32 id = attr->map_id;
1825 int f_flags;
1826 int fd;
1827
1828 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
1829 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
1830 return -EINVAL;
1831
1832 if (!capable(CAP_SYS_ADMIN))
1833 return -EPERM;
1834
1835 f_flags = bpf_get_file_flag(attr->open_flags);
1836 if (f_flags < 0)
1837 return f_flags;
1838
1839 spin_lock_bh(&map_idr_lock);
1840 map = idr_find(&map_idr, id);
1841 if (map)
1842 map = bpf_map_inc_not_zero(map, true);
1843 else
1844 map = ERR_PTR(-ENOENT);
1845 spin_unlock_bh(&map_idr_lock);
1846
1847 if (IS_ERR(map))
1848 return PTR_ERR(map);
1849
1850 fd = bpf_map_new_fd(map, f_flags);
1851 if (fd < 0)
1852 bpf_map_put(map);
1853
1854 return fd;
1855 }
1856
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr)1857 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
1858 unsigned long addr)
1859 {
1860 int i;
1861
1862 for (i = 0; i < prog->aux->used_map_cnt; i++)
1863 if (prog->aux->used_maps[i] == (void *)addr)
1864 return prog->aux->used_maps[i];
1865 return NULL;
1866 }
1867
bpf_insn_prepare_dump(const struct bpf_prog * prog)1868 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
1869 {
1870 const struct bpf_map *map;
1871 struct bpf_insn *insns;
1872 u64 imm;
1873 int i;
1874
1875 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
1876 GFP_USER);
1877 if (!insns)
1878 return insns;
1879
1880 for (i = 0; i < prog->len; i++) {
1881 if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
1882 insns[i].code = BPF_JMP | BPF_CALL;
1883 insns[i].imm = BPF_FUNC_tail_call;
1884 /* fall-through */
1885 }
1886 if (insns[i].code == (BPF_JMP | BPF_CALL) ||
1887 insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
1888 if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
1889 insns[i].code = BPF_JMP | BPF_CALL;
1890 if (!bpf_dump_raw_ok())
1891 insns[i].imm = 0;
1892 continue;
1893 }
1894
1895 if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
1896 continue;
1897
1898 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
1899 map = bpf_map_from_imm(prog, imm);
1900 if (map) {
1901 insns[i].src_reg = BPF_PSEUDO_MAP_FD;
1902 insns[i].imm = map->id;
1903 insns[i + 1].imm = 0;
1904 continue;
1905 }
1906
1907 if (!bpf_dump_raw_ok() &&
1908 imm == (unsigned long)prog->aux) {
1909 insns[i].imm = 0;
1910 insns[i + 1].imm = 0;
1911 continue;
1912 }
1913 }
1914
1915 return insns;
1916 }
1917
bpf_prog_get_info_by_fd(struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)1918 static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
1919 const union bpf_attr *attr,
1920 union bpf_attr __user *uattr)
1921 {
1922 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1923 struct bpf_prog_info info = {};
1924 u32 info_len = attr->info.info_len;
1925 char __user *uinsns;
1926 u32 ulen;
1927 int err;
1928
1929 err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1930 if (err)
1931 return err;
1932 info_len = min_t(u32, sizeof(info), info_len);
1933
1934 if (copy_from_user(&info, uinfo, info_len))
1935 return -EFAULT;
1936
1937 info.type = prog->type;
1938 info.id = prog->aux->id;
1939 info.load_time = prog->aux->load_time;
1940 info.created_by_uid = from_kuid_munged(current_user_ns(),
1941 prog->aux->user->uid);
1942 info.gpl_compatible = prog->gpl_compatible;
1943
1944 memcpy(info.tag, prog->tag, sizeof(prog->tag));
1945 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
1946
1947 ulen = info.nr_map_ids;
1948 info.nr_map_ids = prog->aux->used_map_cnt;
1949 ulen = min_t(u32, info.nr_map_ids, ulen);
1950 if (ulen) {
1951 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
1952 u32 i;
1953
1954 for (i = 0; i < ulen; i++)
1955 if (put_user(prog->aux->used_maps[i]->id,
1956 &user_map_ids[i]))
1957 return -EFAULT;
1958 }
1959
1960 if (!capable(CAP_SYS_ADMIN)) {
1961 info.jited_prog_len = 0;
1962 info.xlated_prog_len = 0;
1963 info.nr_jited_ksyms = 0;
1964 goto done;
1965 }
1966
1967 ulen = info.xlated_prog_len;
1968 info.xlated_prog_len = bpf_prog_insn_size(prog);
1969 if (info.xlated_prog_len && ulen) {
1970 struct bpf_insn *insns_sanitized;
1971 bool fault;
1972
1973 if (prog->blinded && !bpf_dump_raw_ok()) {
1974 info.xlated_prog_insns = 0;
1975 goto done;
1976 }
1977 insns_sanitized = bpf_insn_prepare_dump(prog);
1978 if (!insns_sanitized)
1979 return -ENOMEM;
1980 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
1981 ulen = min_t(u32, info.xlated_prog_len, ulen);
1982 fault = copy_to_user(uinsns, insns_sanitized, ulen);
1983 kfree(insns_sanitized);
1984 if (fault)
1985 return -EFAULT;
1986 }
1987
1988 if (bpf_prog_is_dev_bound(prog->aux)) {
1989 err = bpf_prog_offload_info_fill(&info, prog);
1990 if (err)
1991 return err;
1992 goto done;
1993 }
1994
1995 /* NOTE: the following code is supposed to be skipped for offload.
1996 * bpf_prog_offload_info_fill() is the place to fill similar fields
1997 * for offload.
1998 */
1999 ulen = info.jited_prog_len;
2000 if (prog->aux->func_cnt) {
2001 u32 i;
2002
2003 info.jited_prog_len = 0;
2004 for (i = 0; i < prog->aux->func_cnt; i++)
2005 info.jited_prog_len += prog->aux->func[i]->jited_len;
2006 } else {
2007 info.jited_prog_len = prog->jited_len;
2008 }
2009
2010 if (info.jited_prog_len && ulen) {
2011 if (bpf_dump_raw_ok()) {
2012 uinsns = u64_to_user_ptr(info.jited_prog_insns);
2013 ulen = min_t(u32, info.jited_prog_len, ulen);
2014
2015 /* for multi-function programs, copy the JITed
2016 * instructions for all the functions
2017 */
2018 if (prog->aux->func_cnt) {
2019 u32 len, free, i;
2020 u8 *img;
2021
2022 free = ulen;
2023 for (i = 0; i < prog->aux->func_cnt; i++) {
2024 len = prog->aux->func[i]->jited_len;
2025 len = min_t(u32, len, free);
2026 img = (u8 *) prog->aux->func[i]->bpf_func;
2027 if (copy_to_user(uinsns, img, len))
2028 return -EFAULT;
2029 uinsns += len;
2030 free -= len;
2031 if (!free)
2032 break;
2033 }
2034 } else {
2035 if (copy_to_user(uinsns, prog->bpf_func, ulen))
2036 return -EFAULT;
2037 }
2038 } else {
2039 info.jited_prog_insns = 0;
2040 }
2041 }
2042
2043 ulen = info.nr_jited_ksyms;
2044 info.nr_jited_ksyms = prog->aux->func_cnt;
2045 if (info.nr_jited_ksyms && ulen) {
2046 if (bpf_dump_raw_ok()) {
2047 u64 __user *user_ksyms;
2048 ulong ksym_addr;
2049 u32 i;
2050
2051 /* copy the address of the kernel symbol
2052 * corresponding to each function
2053 */
2054 ulen = min_t(u32, info.nr_jited_ksyms, ulen);
2055 user_ksyms = u64_to_user_ptr(info.jited_ksyms);
2056 for (i = 0; i < ulen; i++) {
2057 ksym_addr = (ulong) prog->aux->func[i]->bpf_func;
2058 ksym_addr &= PAGE_MASK;
2059 if (put_user((u64) ksym_addr, &user_ksyms[i]))
2060 return -EFAULT;
2061 }
2062 } else {
2063 info.jited_ksyms = 0;
2064 }
2065 }
2066
2067 ulen = info.nr_jited_func_lens;
2068 info.nr_jited_func_lens = prog->aux->func_cnt;
2069 if (info.nr_jited_func_lens && ulen) {
2070 if (bpf_dump_raw_ok()) {
2071 u32 __user *user_lens;
2072 u32 func_len, i;
2073
2074 /* copy the JITed image lengths for each function */
2075 ulen = min_t(u32, info.nr_jited_func_lens, ulen);
2076 user_lens = u64_to_user_ptr(info.jited_func_lens);
2077 for (i = 0; i < ulen; i++) {
2078 func_len = prog->aux->func[i]->jited_len;
2079 if (put_user(func_len, &user_lens[i]))
2080 return -EFAULT;
2081 }
2082 } else {
2083 info.jited_func_lens = 0;
2084 }
2085 }
2086
2087 done:
2088 if (copy_to_user(uinfo, &info, info_len) ||
2089 put_user(info_len, &uattr->info.info_len))
2090 return -EFAULT;
2091
2092 return 0;
2093 }
2094
bpf_map_get_info_by_fd(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)2095 static int bpf_map_get_info_by_fd(struct bpf_map *map,
2096 const union bpf_attr *attr,
2097 union bpf_attr __user *uattr)
2098 {
2099 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
2100 struct bpf_map_info info = {};
2101 u32 info_len = attr->info.info_len;
2102 int err;
2103
2104 err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
2105 if (err)
2106 return err;
2107 info_len = min_t(u32, sizeof(info), info_len);
2108
2109 info.type = map->map_type;
2110 info.id = map->id;
2111 info.key_size = map->key_size;
2112 info.value_size = map->value_size;
2113 info.max_entries = map->max_entries;
2114 info.map_flags = map->map_flags;
2115 memcpy(info.name, map->name, sizeof(map->name));
2116
2117 if (map->btf) {
2118 info.btf_id = btf_id(map->btf);
2119 info.btf_key_type_id = map->btf_key_type_id;
2120 info.btf_value_type_id = map->btf_value_type_id;
2121 }
2122
2123 if (bpf_map_is_dev_bound(map)) {
2124 err = bpf_map_offload_info_fill(&info, map);
2125 if (err)
2126 return err;
2127 }
2128
2129 if (copy_to_user(uinfo, &info, info_len) ||
2130 put_user(info_len, &uattr->info.info_len))
2131 return -EFAULT;
2132
2133 return 0;
2134 }
2135
bpf_btf_get_info_by_fd(struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)2136 static int bpf_btf_get_info_by_fd(struct btf *btf,
2137 const union bpf_attr *attr,
2138 union bpf_attr __user *uattr)
2139 {
2140 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
2141 u32 info_len = attr->info.info_len;
2142 int err;
2143
2144 err = bpf_check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len);
2145 if (err)
2146 return err;
2147
2148 return btf_get_info_by_fd(btf, attr, uattr);
2149 }
2150
2151 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
2152
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)2153 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
2154 union bpf_attr __user *uattr)
2155 {
2156 int ufd = attr->info.bpf_fd;
2157 struct fd f;
2158 int err;
2159
2160 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
2161 return -EINVAL;
2162
2163 f = fdget(ufd);
2164 if (!f.file)
2165 return -EBADFD;
2166
2167 if (f.file->f_op == &bpf_prog_fops)
2168 err = bpf_prog_get_info_by_fd(f.file->private_data, attr,
2169 uattr);
2170 else if (f.file->f_op == &bpf_map_fops)
2171 err = bpf_map_get_info_by_fd(f.file->private_data, attr,
2172 uattr);
2173 else if (f.file->f_op == &btf_fops)
2174 err = bpf_btf_get_info_by_fd(f.file->private_data, attr, uattr);
2175 else
2176 err = -EINVAL;
2177
2178 fdput(f);
2179 return err;
2180 }
2181
2182 #define BPF_BTF_LOAD_LAST_FIELD btf_log_level
2183
bpf_btf_load(const union bpf_attr * attr)2184 static int bpf_btf_load(const union bpf_attr *attr)
2185 {
2186 if (CHECK_ATTR(BPF_BTF_LOAD))
2187 return -EINVAL;
2188
2189 if (!capable(CAP_SYS_ADMIN))
2190 return -EPERM;
2191
2192 return btf_new_fd(attr);
2193 }
2194
2195 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
2196
bpf_btf_get_fd_by_id(const union bpf_attr * attr)2197 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
2198 {
2199 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
2200 return -EINVAL;
2201
2202 if (!capable(CAP_SYS_ADMIN))
2203 return -EPERM;
2204
2205 return btf_get_fd_by_id(attr->btf_id);
2206 }
2207
bpf_task_fd_query_copy(const union bpf_attr * attr,union bpf_attr __user * uattr,u32 prog_id,u32 fd_type,const char * buf,u64 probe_offset,u64 probe_addr)2208 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
2209 union bpf_attr __user *uattr,
2210 u32 prog_id, u32 fd_type,
2211 const char *buf, u64 probe_offset,
2212 u64 probe_addr)
2213 {
2214 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
2215 u32 len = buf ? strlen(buf) : 0, input_len;
2216 int err = 0;
2217
2218 if (put_user(len, &uattr->task_fd_query.buf_len))
2219 return -EFAULT;
2220 input_len = attr->task_fd_query.buf_len;
2221 if (input_len && ubuf) {
2222 if (!len) {
2223 /* nothing to copy, just make ubuf NULL terminated */
2224 char zero = '\0';
2225
2226 if (put_user(zero, ubuf))
2227 return -EFAULT;
2228 } else if (input_len >= len + 1) {
2229 /* ubuf can hold the string with NULL terminator */
2230 if (copy_to_user(ubuf, buf, len + 1))
2231 return -EFAULT;
2232 } else {
2233 /* ubuf cannot hold the string with NULL terminator,
2234 * do a partial copy with NULL terminator.
2235 */
2236 char zero = '\0';
2237
2238 err = -ENOSPC;
2239 if (copy_to_user(ubuf, buf, input_len - 1))
2240 return -EFAULT;
2241 if (put_user(zero, ubuf + input_len - 1))
2242 return -EFAULT;
2243 }
2244 }
2245
2246 if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
2247 put_user(fd_type, &uattr->task_fd_query.fd_type) ||
2248 put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
2249 put_user(probe_addr, &uattr->task_fd_query.probe_addr))
2250 return -EFAULT;
2251
2252 return err;
2253 }
2254
2255 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
2256
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)2257 static int bpf_task_fd_query(const union bpf_attr *attr,
2258 union bpf_attr __user *uattr)
2259 {
2260 pid_t pid = attr->task_fd_query.pid;
2261 u32 fd = attr->task_fd_query.fd;
2262 const struct perf_event *event;
2263 struct files_struct *files;
2264 struct task_struct *task;
2265 struct file *file;
2266 int err;
2267
2268 if (CHECK_ATTR(BPF_TASK_FD_QUERY))
2269 return -EINVAL;
2270
2271 if (!capable(CAP_SYS_ADMIN))
2272 return -EPERM;
2273
2274 if (attr->task_fd_query.flags != 0)
2275 return -EINVAL;
2276
2277 task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
2278 if (!task)
2279 return -ENOENT;
2280
2281 files = get_files_struct(task);
2282 put_task_struct(task);
2283 if (!files)
2284 return -ENOENT;
2285
2286 err = 0;
2287 spin_lock(&files->file_lock);
2288 file = fcheck_files(files, fd);
2289 if (!file)
2290 err = -EBADF;
2291 else
2292 get_file(file);
2293 spin_unlock(&files->file_lock);
2294 put_files_struct(files);
2295
2296 if (err)
2297 goto out;
2298
2299 if (file->f_op == &bpf_raw_tp_fops) {
2300 struct bpf_raw_tracepoint *raw_tp = file->private_data;
2301 struct bpf_raw_event_map *btp = raw_tp->btp;
2302
2303 err = bpf_task_fd_query_copy(attr, uattr,
2304 raw_tp->prog->aux->id,
2305 BPF_FD_TYPE_RAW_TRACEPOINT,
2306 btp->tp->name, 0, 0);
2307 goto put_file;
2308 }
2309
2310 event = perf_get_event(file);
2311 if (!IS_ERR(event)) {
2312 u64 probe_offset, probe_addr;
2313 u32 prog_id, fd_type;
2314 const char *buf;
2315
2316 err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
2317 &buf, &probe_offset,
2318 &probe_addr);
2319 if (!err)
2320 err = bpf_task_fd_query_copy(attr, uattr, prog_id,
2321 fd_type, buf,
2322 probe_offset,
2323 probe_addr);
2324 goto put_file;
2325 }
2326
2327 err = -ENOTSUPP;
2328 put_file:
2329 fput(file);
2330 out:
2331 return err;
2332 }
2333
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)2334 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
2335 {
2336 union bpf_attr attr = {};
2337 int err;
2338
2339 if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN))
2340 return -EPERM;
2341
2342 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
2343 if (err)
2344 return err;
2345 size = min_t(u32, size, sizeof(attr));
2346
2347 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
2348 if (copy_from_user(&attr, uattr, size) != 0)
2349 return -EFAULT;
2350
2351 err = security_bpf(cmd, &attr, size);
2352 if (err < 0)
2353 return err;
2354
2355 switch (cmd) {
2356 case BPF_MAP_CREATE:
2357 err = map_create(&attr);
2358 break;
2359 case BPF_MAP_LOOKUP_ELEM:
2360 err = map_lookup_elem(&attr);
2361 break;
2362 case BPF_MAP_UPDATE_ELEM:
2363 err = map_update_elem(&attr);
2364 break;
2365 case BPF_MAP_DELETE_ELEM:
2366 err = map_delete_elem(&attr);
2367 break;
2368 case BPF_MAP_GET_NEXT_KEY:
2369 err = map_get_next_key(&attr);
2370 break;
2371 case BPF_PROG_LOAD:
2372 err = bpf_prog_load(&attr);
2373 break;
2374 case BPF_OBJ_PIN:
2375 err = bpf_obj_pin(&attr);
2376 break;
2377 case BPF_OBJ_GET:
2378 err = bpf_obj_get(&attr);
2379 break;
2380 case BPF_PROG_ATTACH:
2381 err = bpf_prog_attach(&attr);
2382 break;
2383 case BPF_PROG_DETACH:
2384 err = bpf_prog_detach(&attr);
2385 break;
2386 case BPF_PROG_QUERY:
2387 err = bpf_prog_query(&attr, uattr);
2388 break;
2389 case BPF_PROG_TEST_RUN:
2390 err = bpf_prog_test_run(&attr, uattr);
2391 break;
2392 case BPF_PROG_GET_NEXT_ID:
2393 err = bpf_obj_get_next_id(&attr, uattr,
2394 &prog_idr, &prog_idr_lock);
2395 break;
2396 case BPF_MAP_GET_NEXT_ID:
2397 err = bpf_obj_get_next_id(&attr, uattr,
2398 &map_idr, &map_idr_lock);
2399 break;
2400 case BPF_PROG_GET_FD_BY_ID:
2401 err = bpf_prog_get_fd_by_id(&attr);
2402 break;
2403 case BPF_MAP_GET_FD_BY_ID:
2404 err = bpf_map_get_fd_by_id(&attr);
2405 break;
2406 case BPF_OBJ_GET_INFO_BY_FD:
2407 err = bpf_obj_get_info_by_fd(&attr, uattr);
2408 break;
2409 case BPF_RAW_TRACEPOINT_OPEN:
2410 err = bpf_raw_tracepoint_open(&attr);
2411 break;
2412 case BPF_BTF_LOAD:
2413 err = bpf_btf_load(&attr);
2414 break;
2415 case BPF_BTF_GET_FD_BY_ID:
2416 err = bpf_btf_get_fd_by_id(&attr);
2417 break;
2418 case BPF_TASK_FD_QUERY:
2419 err = bpf_task_fd_query(&attr, uattr);
2420 break;
2421 default:
2422 err = -EINVAL;
2423 break;
2424 }
2425
2426 return err;
2427 }
2428