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_with_uref() 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_with_uref(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 goto done;
705 }
706
707 preempt_disable();
708 this_cpu_inc(bpf_prog_active);
709 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
710 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
711 err = bpf_percpu_hash_copy(map, key, value);
712 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
713 err = bpf_percpu_array_copy(map, key, value);
714 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
715 err = bpf_stackmap_copy(map, key, value);
716 } else if (IS_FD_ARRAY(map)) {
717 err = bpf_fd_array_map_lookup_elem(map, key, value);
718 } else if (IS_FD_HASH(map)) {
719 err = bpf_fd_htab_map_lookup_elem(map, key, value);
720 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
721 err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
722 } else {
723 rcu_read_lock();
724 if (map->ops->map_lookup_elem_sys_only)
725 ptr = map->ops->map_lookup_elem_sys_only(map, key);
726 else
727 ptr = map->ops->map_lookup_elem(map, key);
728 if (ptr)
729 memcpy(value, ptr, value_size);
730 rcu_read_unlock();
731 err = ptr ? 0 : -ENOENT;
732 }
733 this_cpu_dec(bpf_prog_active);
734 preempt_enable();
735
736 done:
737 if (err)
738 goto free_value;
739
740 err = -EFAULT;
741 if (copy_to_user(uvalue, value, value_size) != 0)
742 goto free_value;
743
744 err = 0;
745
746 free_value:
747 kfree(value);
748 free_key:
749 kfree(key);
750 err_put:
751 fdput(f);
752 return err;
753 }
754
maybe_wait_bpf_programs(struct bpf_map * map)755 static void maybe_wait_bpf_programs(struct bpf_map *map)
756 {
757 /* Wait for any running BPF programs to complete so that
758 * userspace, when we return to it, knows that all programs
759 * that could be running use the new map value.
760 */
761 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
762 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
763 synchronize_rcu();
764 }
765
766 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
767
map_update_elem(union bpf_attr * attr)768 static int map_update_elem(union bpf_attr *attr)
769 {
770 void __user *ukey = u64_to_user_ptr(attr->key);
771 void __user *uvalue = u64_to_user_ptr(attr->value);
772 int ufd = attr->map_fd;
773 struct bpf_map *map;
774 void *key, *value;
775 u32 value_size;
776 struct fd f;
777 int err;
778
779 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
780 return -EINVAL;
781
782 f = fdget(ufd);
783 map = __bpf_map_get(f);
784 if (IS_ERR(map))
785 return PTR_ERR(map);
786
787 if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
788 err = -EPERM;
789 goto err_put;
790 }
791
792 key = memdup_user(ukey, map->key_size);
793 if (IS_ERR(key)) {
794 err = PTR_ERR(key);
795 goto err_put;
796 }
797
798 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
799 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
800 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
801 value_size = round_up(map->value_size, 8) * num_possible_cpus();
802 else
803 value_size = map->value_size;
804
805 err = -ENOMEM;
806 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
807 if (!value)
808 goto free_key;
809
810 err = -EFAULT;
811 if (copy_from_user(value, uvalue, value_size) != 0)
812 goto free_value;
813
814 /* Need to create a kthread, thus must support schedule */
815 if (bpf_map_is_dev_bound(map)) {
816 err = bpf_map_offload_update_elem(map, key, value, attr->flags);
817 goto out;
818 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
819 map->map_type == BPF_MAP_TYPE_SOCKHASH ||
820 map->map_type == BPF_MAP_TYPE_SOCKMAP) {
821 err = map->ops->map_update_elem(map, key, value, attr->flags);
822 goto out;
823 }
824
825 /* must increment bpf_prog_active to avoid kprobe+bpf triggering from
826 * inside bpf map update or delete otherwise deadlocks are possible
827 */
828 preempt_disable();
829 __this_cpu_inc(bpf_prog_active);
830 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
831 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
832 err = bpf_percpu_hash_update(map, key, value, attr->flags);
833 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
834 err = bpf_percpu_array_update(map, key, value, attr->flags);
835 } else if (IS_FD_ARRAY(map)) {
836 rcu_read_lock();
837 err = bpf_fd_array_map_update_elem(map, f.file, key, value,
838 attr->flags);
839 rcu_read_unlock();
840 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
841 rcu_read_lock();
842 err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
843 attr->flags);
844 rcu_read_unlock();
845 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
846 /* rcu_read_lock() is not needed */
847 err = bpf_fd_reuseport_array_update_elem(map, key, value,
848 attr->flags);
849 } else {
850 rcu_read_lock();
851 err = map->ops->map_update_elem(map, key, value, attr->flags);
852 rcu_read_unlock();
853 }
854 __this_cpu_dec(bpf_prog_active);
855 preempt_enable();
856 maybe_wait_bpf_programs(map);
857 out:
858 free_value:
859 kfree(value);
860 free_key:
861 kfree(key);
862 err_put:
863 fdput(f);
864 return err;
865 }
866
867 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
868
map_delete_elem(union bpf_attr * attr)869 static int map_delete_elem(union bpf_attr *attr)
870 {
871 void __user *ukey = u64_to_user_ptr(attr->key);
872 int ufd = attr->map_fd;
873 struct bpf_map *map;
874 struct fd f;
875 void *key;
876 int err;
877
878 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
879 return -EINVAL;
880
881 f = fdget(ufd);
882 map = __bpf_map_get(f);
883 if (IS_ERR(map))
884 return PTR_ERR(map);
885
886 if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
887 err = -EPERM;
888 goto err_put;
889 }
890
891 key = memdup_user(ukey, map->key_size);
892 if (IS_ERR(key)) {
893 err = PTR_ERR(key);
894 goto err_put;
895 }
896
897 if (bpf_map_is_dev_bound(map)) {
898 err = bpf_map_offload_delete_elem(map, key);
899 goto out;
900 }
901
902 preempt_disable();
903 __this_cpu_inc(bpf_prog_active);
904 rcu_read_lock();
905 err = map->ops->map_delete_elem(map, key);
906 rcu_read_unlock();
907 __this_cpu_dec(bpf_prog_active);
908 preempt_enable();
909 maybe_wait_bpf_programs(map);
910 out:
911 kfree(key);
912 err_put:
913 fdput(f);
914 return err;
915 }
916
917 /* last field in 'union bpf_attr' used by this command */
918 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
919
map_get_next_key(union bpf_attr * attr)920 static int map_get_next_key(union bpf_attr *attr)
921 {
922 void __user *ukey = u64_to_user_ptr(attr->key);
923 void __user *unext_key = u64_to_user_ptr(attr->next_key);
924 int ufd = attr->map_fd;
925 struct bpf_map *map;
926 void *key, *next_key;
927 struct fd f;
928 int err;
929
930 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
931 return -EINVAL;
932
933 f = fdget(ufd);
934 map = __bpf_map_get(f);
935 if (IS_ERR(map))
936 return PTR_ERR(map);
937
938 if (!(f.file->f_mode & FMODE_CAN_READ)) {
939 err = -EPERM;
940 goto err_put;
941 }
942
943 if (ukey) {
944 key = memdup_user(ukey, map->key_size);
945 if (IS_ERR(key)) {
946 err = PTR_ERR(key);
947 goto err_put;
948 }
949 } else {
950 key = NULL;
951 }
952
953 err = -ENOMEM;
954 next_key = kmalloc(map->key_size, GFP_USER);
955 if (!next_key)
956 goto free_key;
957
958 if (bpf_map_is_dev_bound(map)) {
959 err = bpf_map_offload_get_next_key(map, key, next_key);
960 goto out;
961 }
962
963 rcu_read_lock();
964 err = map->ops->map_get_next_key(map, key, next_key);
965 rcu_read_unlock();
966 out:
967 if (err)
968 goto free_next_key;
969
970 err = -EFAULT;
971 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
972 goto free_next_key;
973
974 err = 0;
975
976 free_next_key:
977 kfree(next_key);
978 free_key:
979 kfree(key);
980 err_put:
981 fdput(f);
982 return err;
983 }
984
985 static const struct bpf_prog_ops * const bpf_prog_types[] = {
986 #define BPF_PROG_TYPE(_id, _name) \
987 [_id] = & _name ## _prog_ops,
988 #define BPF_MAP_TYPE(_id, _ops)
989 #include <linux/bpf_types.h>
990 #undef BPF_PROG_TYPE
991 #undef BPF_MAP_TYPE
992 };
993
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)994 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
995 {
996 const struct bpf_prog_ops *ops;
997
998 if (type >= ARRAY_SIZE(bpf_prog_types))
999 return -EINVAL;
1000 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
1001 ops = bpf_prog_types[type];
1002 if (!ops)
1003 return -EINVAL;
1004
1005 if (!bpf_prog_is_dev_bound(prog->aux))
1006 prog->aux->ops = ops;
1007 else
1008 prog->aux->ops = &bpf_offload_prog_ops;
1009 prog->type = type;
1010 return 0;
1011 }
1012
1013 /* drop refcnt on maps used by eBPF program and free auxilary data */
free_used_maps(struct bpf_prog_aux * aux)1014 static void free_used_maps(struct bpf_prog_aux *aux)
1015 {
1016 int i;
1017
1018 if (aux->cgroup_storage)
1019 bpf_cgroup_storage_release(aux->prog, aux->cgroup_storage);
1020
1021 for (i = 0; i < aux->used_map_cnt; i++)
1022 bpf_map_put(aux->used_maps[i]);
1023
1024 kfree(aux->used_maps);
1025 }
1026
__bpf_prog_charge(struct user_struct * user,u32 pages)1027 int __bpf_prog_charge(struct user_struct *user, u32 pages)
1028 {
1029 unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1030 unsigned long user_bufs;
1031
1032 if (user) {
1033 user_bufs = atomic_long_add_return(pages, &user->locked_vm);
1034 if (user_bufs > memlock_limit) {
1035 atomic_long_sub(pages, &user->locked_vm);
1036 return -EPERM;
1037 }
1038 }
1039
1040 return 0;
1041 }
1042
__bpf_prog_uncharge(struct user_struct * user,u32 pages)1043 void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
1044 {
1045 if (user)
1046 atomic_long_sub(pages, &user->locked_vm);
1047 }
1048
bpf_prog_charge_memlock(struct bpf_prog * prog)1049 static int bpf_prog_charge_memlock(struct bpf_prog *prog)
1050 {
1051 struct user_struct *user = get_current_user();
1052 int ret;
1053
1054 ret = __bpf_prog_charge(user, prog->pages);
1055 if (ret) {
1056 free_uid(user);
1057 return ret;
1058 }
1059
1060 prog->aux->user = user;
1061 return 0;
1062 }
1063
bpf_prog_uncharge_memlock(struct bpf_prog * prog)1064 static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
1065 {
1066 struct user_struct *user = prog->aux->user;
1067
1068 __bpf_prog_uncharge(user, prog->pages);
1069 free_uid(user);
1070 }
1071
bpf_prog_alloc_id(struct bpf_prog * prog)1072 static int bpf_prog_alloc_id(struct bpf_prog *prog)
1073 {
1074 int id;
1075
1076 idr_preload(GFP_KERNEL);
1077 spin_lock_bh(&prog_idr_lock);
1078 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
1079 if (id > 0)
1080 prog->aux->id = id;
1081 spin_unlock_bh(&prog_idr_lock);
1082 idr_preload_end();
1083
1084 /* id is in [1, INT_MAX) */
1085 if (WARN_ON_ONCE(!id))
1086 return -ENOSPC;
1087
1088 return id > 0 ? 0 : id;
1089 }
1090
bpf_prog_free_id(struct bpf_prog * prog,bool do_idr_lock)1091 void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
1092 {
1093 /* cBPF to eBPF migrations are currently not in the idr store.
1094 * Offloaded programs are removed from the store when their device
1095 * disappears - even if someone grabs an fd to them they are unusable,
1096 * simply waiting for refcnt to drop to be freed.
1097 */
1098 if (!prog->aux->id)
1099 return;
1100
1101 if (do_idr_lock)
1102 spin_lock_bh(&prog_idr_lock);
1103 else
1104 __acquire(&prog_idr_lock);
1105
1106 idr_remove(&prog_idr, prog->aux->id);
1107 prog->aux->id = 0;
1108
1109 if (do_idr_lock)
1110 spin_unlock_bh(&prog_idr_lock);
1111 else
1112 __release(&prog_idr_lock);
1113 }
1114
__bpf_prog_put_rcu(struct rcu_head * rcu)1115 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
1116 {
1117 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
1118
1119 free_used_maps(aux);
1120 bpf_prog_uncharge_memlock(aux->prog);
1121 security_bpf_prog_free(aux);
1122 bpf_prog_free(aux->prog);
1123 }
1124
__bpf_prog_put(struct bpf_prog * prog,bool do_idr_lock)1125 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
1126 {
1127 if (atomic_dec_and_test(&prog->aux->refcnt)) {
1128 /* bpf_prog_free_id() must be called first */
1129 bpf_prog_free_id(prog, do_idr_lock);
1130 bpf_prog_kallsyms_del_all(prog);
1131
1132 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
1133 }
1134 }
1135
bpf_prog_put(struct bpf_prog * prog)1136 void bpf_prog_put(struct bpf_prog *prog)
1137 {
1138 __bpf_prog_put(prog, true);
1139 }
1140 EXPORT_SYMBOL_GPL(bpf_prog_put);
1141
bpf_prog_release(struct inode * inode,struct file * filp)1142 static int bpf_prog_release(struct inode *inode, struct file *filp)
1143 {
1144 struct bpf_prog *prog = filp->private_data;
1145
1146 bpf_prog_put(prog);
1147 return 0;
1148 }
1149
1150 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)1151 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
1152 {
1153 const struct bpf_prog *prog = filp->private_data;
1154 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
1155
1156 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
1157 seq_printf(m,
1158 "prog_type:\t%u\n"
1159 "prog_jited:\t%u\n"
1160 "prog_tag:\t%s\n"
1161 "memlock:\t%llu\n"
1162 "prog_id:\t%u\n",
1163 prog->type,
1164 prog->jited,
1165 prog_tag,
1166 prog->pages * 1ULL << PAGE_SHIFT,
1167 prog->aux->id);
1168 }
1169 #endif
1170
1171 const struct file_operations bpf_prog_fops = {
1172 #ifdef CONFIG_PROC_FS
1173 .show_fdinfo = bpf_prog_show_fdinfo,
1174 #endif
1175 .release = bpf_prog_release,
1176 .read = bpf_dummy_read,
1177 .write = bpf_dummy_write,
1178 };
1179
bpf_prog_new_fd(struct bpf_prog * prog)1180 int bpf_prog_new_fd(struct bpf_prog *prog)
1181 {
1182 int ret;
1183
1184 ret = security_bpf_prog(prog);
1185 if (ret < 0)
1186 return ret;
1187
1188 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
1189 O_RDWR | O_CLOEXEC);
1190 }
1191
____bpf_prog_get(struct fd f)1192 static struct bpf_prog *____bpf_prog_get(struct fd f)
1193 {
1194 if (!f.file)
1195 return ERR_PTR(-EBADF);
1196 if (f.file->f_op != &bpf_prog_fops) {
1197 fdput(f);
1198 return ERR_PTR(-EINVAL);
1199 }
1200
1201 return f.file->private_data;
1202 }
1203
bpf_prog_add(struct bpf_prog * prog,int i)1204 struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
1205 {
1206 if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
1207 atomic_sub(i, &prog->aux->refcnt);
1208 return ERR_PTR(-EBUSY);
1209 }
1210 return prog;
1211 }
1212 EXPORT_SYMBOL_GPL(bpf_prog_add);
1213
bpf_prog_sub(struct bpf_prog * prog,int i)1214 void bpf_prog_sub(struct bpf_prog *prog, int i)
1215 {
1216 /* Only to be used for undoing previous bpf_prog_add() in some
1217 * error path. We still know that another entity in our call
1218 * path holds a reference to the program, thus atomic_sub() can
1219 * be safely used in such cases!
1220 */
1221 WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
1222 }
1223 EXPORT_SYMBOL_GPL(bpf_prog_sub);
1224
bpf_prog_inc(struct bpf_prog * prog)1225 struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
1226 {
1227 return bpf_prog_add(prog, 1);
1228 }
1229 EXPORT_SYMBOL_GPL(bpf_prog_inc);
1230
1231 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)1232 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
1233 {
1234 int refold;
1235
1236 refold = atomic_fetch_add_unless(&prog->aux->refcnt, 1, 0);
1237
1238 if (refold >= BPF_MAX_REFCNT) {
1239 __bpf_prog_put(prog, false);
1240 return ERR_PTR(-EBUSY);
1241 }
1242
1243 if (!refold)
1244 return ERR_PTR(-ENOENT);
1245
1246 return prog;
1247 }
1248 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
1249
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)1250 bool bpf_prog_get_ok(struct bpf_prog *prog,
1251 enum bpf_prog_type *attach_type, bool attach_drv)
1252 {
1253 /* not an attachment, just a refcount inc, always allow */
1254 if (!attach_type)
1255 return true;
1256
1257 if (prog->type != *attach_type)
1258 return false;
1259 if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
1260 return false;
1261
1262 return true;
1263 }
1264
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)1265 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
1266 bool attach_drv)
1267 {
1268 struct fd f = fdget(ufd);
1269 struct bpf_prog *prog;
1270
1271 prog = ____bpf_prog_get(f);
1272 if (IS_ERR(prog))
1273 return prog;
1274 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
1275 prog = ERR_PTR(-EINVAL);
1276 goto out;
1277 }
1278
1279 prog = bpf_prog_inc(prog);
1280 out:
1281 fdput(f);
1282 return prog;
1283 }
1284
bpf_prog_get(u32 ufd)1285 struct bpf_prog *bpf_prog_get(u32 ufd)
1286 {
1287 return __bpf_prog_get(ufd, NULL, false);
1288 }
1289
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)1290 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
1291 bool attach_drv)
1292 {
1293 return __bpf_prog_get(ufd, &type, attach_drv);
1294 }
1295 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
1296
1297 /* Initially all BPF programs could be loaded w/o specifying
1298 * expected_attach_type. Later for some of them specifying expected_attach_type
1299 * at load time became required so that program could be validated properly.
1300 * Programs of types that are allowed to be loaded both w/ and w/o (for
1301 * backward compatibility) expected_attach_type, should have the default attach
1302 * type assigned to expected_attach_type for the latter case, so that it can be
1303 * validated later at attach time.
1304 *
1305 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
1306 * prog type requires it but has some attach types that have to be backward
1307 * compatible.
1308 */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)1309 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
1310 {
1311 switch (attr->prog_type) {
1312 case BPF_PROG_TYPE_CGROUP_SOCK:
1313 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
1314 * exist so checking for non-zero is the way to go here.
1315 */
1316 if (!attr->expected_attach_type)
1317 attr->expected_attach_type =
1318 BPF_CGROUP_INET_SOCK_CREATE;
1319 break;
1320 }
1321 }
1322
1323 static int
bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,enum bpf_attach_type expected_attach_type)1324 bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
1325 enum bpf_attach_type expected_attach_type)
1326 {
1327 switch (prog_type) {
1328 case BPF_PROG_TYPE_CGROUP_SOCK:
1329 switch (expected_attach_type) {
1330 case BPF_CGROUP_INET_SOCK_CREATE:
1331 case BPF_CGROUP_INET4_POST_BIND:
1332 case BPF_CGROUP_INET6_POST_BIND:
1333 return 0;
1334 default:
1335 return -EINVAL;
1336 }
1337 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
1338 switch (expected_attach_type) {
1339 case BPF_CGROUP_INET4_BIND:
1340 case BPF_CGROUP_INET6_BIND:
1341 case BPF_CGROUP_INET4_CONNECT:
1342 case BPF_CGROUP_INET6_CONNECT:
1343 case BPF_CGROUP_UDP4_SENDMSG:
1344 case BPF_CGROUP_UDP6_SENDMSG:
1345 case BPF_CGROUP_UDP4_RECVMSG:
1346 case BPF_CGROUP_UDP6_RECVMSG:
1347 return 0;
1348 default:
1349 return -EINVAL;
1350 }
1351 default:
1352 return 0;
1353 }
1354 }
1355
1356 /* last field in 'union bpf_attr' used by this command */
1357 #define BPF_PROG_LOAD_LAST_FIELD expected_attach_type
1358
bpf_prog_load(union bpf_attr * attr)1359 static int bpf_prog_load(union bpf_attr *attr)
1360 {
1361 enum bpf_prog_type type = attr->prog_type;
1362 struct bpf_prog *prog;
1363 int err;
1364 char license[128];
1365 bool is_gpl;
1366
1367 if (CHECK_ATTR(BPF_PROG_LOAD))
1368 return -EINVAL;
1369
1370 if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
1371 return -EINVAL;
1372
1373 /* copy eBPF program license from user space */
1374 if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
1375 sizeof(license) - 1) < 0)
1376 return -EFAULT;
1377 license[sizeof(license) - 1] = 0;
1378
1379 /* eBPF programs must be GPL compatible to use GPL-ed functions */
1380 is_gpl = license_is_gpl_compatible(license);
1381
1382 if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
1383 return -E2BIG;
1384
1385 if (type == BPF_PROG_TYPE_KPROBE &&
1386 attr->kern_version != LINUX_VERSION_CODE)
1387 return -EINVAL;
1388
1389 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
1390 type != BPF_PROG_TYPE_CGROUP_SKB &&
1391 !capable(CAP_SYS_ADMIN))
1392 return -EPERM;
1393
1394 bpf_prog_load_fixup_attach_type(attr);
1395 if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type))
1396 return -EINVAL;
1397
1398 /* plain bpf_prog allocation */
1399 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
1400 if (!prog)
1401 return -ENOMEM;
1402
1403 prog->expected_attach_type = attr->expected_attach_type;
1404
1405 prog->aux->offload_requested = !!attr->prog_ifindex;
1406
1407 err = security_bpf_prog_alloc(prog->aux);
1408 if (err)
1409 goto free_prog_nouncharge;
1410
1411 err = bpf_prog_charge_memlock(prog);
1412 if (err)
1413 goto free_prog_sec;
1414
1415 prog->len = attr->insn_cnt;
1416
1417 err = -EFAULT;
1418 if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
1419 bpf_prog_insn_size(prog)) != 0)
1420 goto free_prog;
1421
1422 prog->orig_prog = NULL;
1423 prog->jited = 0;
1424
1425 atomic_set(&prog->aux->refcnt, 1);
1426 prog->gpl_compatible = is_gpl ? 1 : 0;
1427
1428 if (bpf_prog_is_dev_bound(prog->aux)) {
1429 err = bpf_prog_offload_init(prog, attr);
1430 if (err)
1431 goto free_prog;
1432 }
1433
1434 /* find program type: socket_filter vs tracing_filter */
1435 err = find_prog_type(type, prog);
1436 if (err < 0)
1437 goto free_prog;
1438
1439 prog->aux->load_time = ktime_get_boot_ns();
1440 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name);
1441 if (err)
1442 goto free_prog;
1443
1444 /* run eBPF verifier */
1445 err = bpf_check(&prog, attr);
1446 if (err < 0)
1447 goto free_used_maps;
1448
1449 prog = bpf_prog_select_runtime(prog, &err);
1450 if (err < 0)
1451 goto free_used_maps;
1452
1453 err = bpf_prog_alloc_id(prog);
1454 if (err)
1455 goto free_used_maps;
1456
1457 /* Upon success of bpf_prog_alloc_id(), the BPF prog is
1458 * effectively publicly exposed. However, retrieving via
1459 * bpf_prog_get_fd_by_id() will take another reference,
1460 * therefore it cannot be gone underneath us.
1461 *
1462 * Only for the time /after/ successful bpf_prog_new_fd()
1463 * and before returning to userspace, we might just hold
1464 * one reference and any parallel close on that fd could
1465 * rip everything out. Hence, below notifications must
1466 * happen before bpf_prog_new_fd().
1467 *
1468 * Also, any failure handling from this point onwards must
1469 * be using bpf_prog_put() given the program is exposed.
1470 */
1471 bpf_prog_kallsyms_add(prog);
1472
1473 err = bpf_prog_new_fd(prog);
1474 if (err < 0)
1475 bpf_prog_put(prog);
1476 return err;
1477
1478 free_used_maps:
1479 bpf_prog_kallsyms_del_subprogs(prog);
1480 free_used_maps(prog->aux);
1481 free_prog:
1482 bpf_prog_uncharge_memlock(prog);
1483 free_prog_sec:
1484 security_bpf_prog_free(prog->aux);
1485 free_prog_nouncharge:
1486 bpf_prog_free(prog);
1487 return err;
1488 }
1489
1490 #define BPF_OBJ_LAST_FIELD file_flags
1491
bpf_obj_pin(const union bpf_attr * attr)1492 static int bpf_obj_pin(const union bpf_attr *attr)
1493 {
1494 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
1495 return -EINVAL;
1496
1497 return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
1498 }
1499
bpf_obj_get(const union bpf_attr * attr)1500 static int bpf_obj_get(const union bpf_attr *attr)
1501 {
1502 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
1503 attr->file_flags & ~BPF_OBJ_FLAG_MASK)
1504 return -EINVAL;
1505
1506 return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
1507 attr->file_flags);
1508 }
1509
1510 struct bpf_raw_tracepoint {
1511 struct bpf_raw_event_map *btp;
1512 struct bpf_prog *prog;
1513 };
1514
bpf_raw_tracepoint_release(struct inode * inode,struct file * filp)1515 static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp)
1516 {
1517 struct bpf_raw_tracepoint *raw_tp = filp->private_data;
1518
1519 if (raw_tp->prog) {
1520 bpf_probe_unregister(raw_tp->btp, raw_tp->prog);
1521 bpf_prog_put(raw_tp->prog);
1522 }
1523 kfree(raw_tp);
1524 return 0;
1525 }
1526
1527 static const struct file_operations bpf_raw_tp_fops = {
1528 .release = bpf_raw_tracepoint_release,
1529 .read = bpf_dummy_read,
1530 .write = bpf_dummy_write,
1531 };
1532
1533 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
1534
bpf_raw_tracepoint_open(const union bpf_attr * attr)1535 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
1536 {
1537 struct bpf_raw_tracepoint *raw_tp;
1538 struct bpf_raw_event_map *btp;
1539 struct bpf_prog *prog;
1540 char tp_name[128];
1541 int tp_fd, err;
1542
1543 if (strncpy_from_user(tp_name, u64_to_user_ptr(attr->raw_tracepoint.name),
1544 sizeof(tp_name) - 1) < 0)
1545 return -EFAULT;
1546 tp_name[sizeof(tp_name) - 1] = 0;
1547
1548 btp = bpf_find_raw_tracepoint(tp_name);
1549 if (!btp)
1550 return -ENOENT;
1551
1552 raw_tp = kzalloc(sizeof(*raw_tp), GFP_USER);
1553 if (!raw_tp)
1554 return -ENOMEM;
1555 raw_tp->btp = btp;
1556
1557 prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd,
1558 BPF_PROG_TYPE_RAW_TRACEPOINT);
1559 if (IS_ERR(prog)) {
1560 err = PTR_ERR(prog);
1561 goto out_free_tp;
1562 }
1563
1564 err = bpf_probe_register(raw_tp->btp, prog);
1565 if (err)
1566 goto out_put_prog;
1567
1568 raw_tp->prog = prog;
1569 tp_fd = anon_inode_getfd("bpf-raw-tracepoint", &bpf_raw_tp_fops, raw_tp,
1570 O_CLOEXEC);
1571 if (tp_fd < 0) {
1572 bpf_probe_unregister(raw_tp->btp, prog);
1573 err = tp_fd;
1574 goto out_put_prog;
1575 }
1576 return tp_fd;
1577
1578 out_put_prog:
1579 bpf_prog_put(prog);
1580 out_free_tp:
1581 kfree(raw_tp);
1582 return err;
1583 }
1584
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)1585 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
1586 enum bpf_attach_type attach_type)
1587 {
1588 switch (prog->type) {
1589 case BPF_PROG_TYPE_CGROUP_SOCK:
1590 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
1591 return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
1592 default:
1593 return 0;
1594 }
1595 }
1596
1597 #define BPF_PROG_ATTACH_LAST_FIELD attach_flags
1598
1599 #define BPF_F_ATTACH_MASK \
1600 (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
1601
bpf_prog_attach(const union bpf_attr * attr)1602 static int bpf_prog_attach(const union bpf_attr *attr)
1603 {
1604 enum bpf_prog_type ptype;
1605 struct bpf_prog *prog;
1606 int ret;
1607
1608 if (!capable(CAP_NET_ADMIN))
1609 return -EPERM;
1610
1611 if (CHECK_ATTR(BPF_PROG_ATTACH))
1612 return -EINVAL;
1613
1614 if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
1615 return -EINVAL;
1616
1617 switch (attr->attach_type) {
1618 case BPF_CGROUP_INET_INGRESS:
1619 case BPF_CGROUP_INET_EGRESS:
1620 ptype = BPF_PROG_TYPE_CGROUP_SKB;
1621 break;
1622 case BPF_CGROUP_INET_SOCK_CREATE:
1623 case BPF_CGROUP_INET4_POST_BIND:
1624 case BPF_CGROUP_INET6_POST_BIND:
1625 ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1626 break;
1627 case BPF_CGROUP_INET4_BIND:
1628 case BPF_CGROUP_INET6_BIND:
1629 case BPF_CGROUP_INET4_CONNECT:
1630 case BPF_CGROUP_INET6_CONNECT:
1631 case BPF_CGROUP_UDP4_SENDMSG:
1632 case BPF_CGROUP_UDP6_SENDMSG:
1633 case BPF_CGROUP_UDP4_RECVMSG:
1634 case BPF_CGROUP_UDP6_RECVMSG:
1635 ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
1636 break;
1637 case BPF_CGROUP_SOCK_OPS:
1638 ptype = BPF_PROG_TYPE_SOCK_OPS;
1639 break;
1640 case BPF_CGROUP_DEVICE:
1641 ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1642 break;
1643 case BPF_SK_MSG_VERDICT:
1644 ptype = BPF_PROG_TYPE_SK_MSG;
1645 break;
1646 case BPF_SK_SKB_STREAM_PARSER:
1647 case BPF_SK_SKB_STREAM_VERDICT:
1648 ptype = BPF_PROG_TYPE_SK_SKB;
1649 break;
1650 case BPF_LIRC_MODE2:
1651 ptype = BPF_PROG_TYPE_LIRC_MODE2;
1652 break;
1653 default:
1654 return -EINVAL;
1655 }
1656
1657 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1658 if (IS_ERR(prog))
1659 return PTR_ERR(prog);
1660
1661 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
1662 bpf_prog_put(prog);
1663 return -EINVAL;
1664 }
1665
1666 switch (ptype) {
1667 case BPF_PROG_TYPE_SK_SKB:
1668 case BPF_PROG_TYPE_SK_MSG:
1669 ret = sockmap_get_from_fd(attr, ptype, prog);
1670 break;
1671 case BPF_PROG_TYPE_LIRC_MODE2:
1672 ret = lirc_prog_attach(attr, prog);
1673 break;
1674 default:
1675 ret = cgroup_bpf_prog_attach(attr, ptype, prog);
1676 }
1677
1678 if (ret)
1679 bpf_prog_put(prog);
1680 return ret;
1681 }
1682
1683 #define BPF_PROG_DETACH_LAST_FIELD attach_type
1684
bpf_prog_detach(const union bpf_attr * attr)1685 static int bpf_prog_detach(const union bpf_attr *attr)
1686 {
1687 enum bpf_prog_type ptype;
1688
1689 if (!capable(CAP_NET_ADMIN))
1690 return -EPERM;
1691
1692 if (CHECK_ATTR(BPF_PROG_DETACH))
1693 return -EINVAL;
1694
1695 switch (attr->attach_type) {
1696 case BPF_CGROUP_INET_INGRESS:
1697 case BPF_CGROUP_INET_EGRESS:
1698 ptype = BPF_PROG_TYPE_CGROUP_SKB;
1699 break;
1700 case BPF_CGROUP_INET_SOCK_CREATE:
1701 case BPF_CGROUP_INET4_POST_BIND:
1702 case BPF_CGROUP_INET6_POST_BIND:
1703 ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1704 break;
1705 case BPF_CGROUP_INET4_BIND:
1706 case BPF_CGROUP_INET6_BIND:
1707 case BPF_CGROUP_INET4_CONNECT:
1708 case BPF_CGROUP_INET6_CONNECT:
1709 case BPF_CGROUP_UDP4_SENDMSG:
1710 case BPF_CGROUP_UDP6_SENDMSG:
1711 case BPF_CGROUP_UDP4_RECVMSG:
1712 case BPF_CGROUP_UDP6_RECVMSG:
1713 ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
1714 break;
1715 case BPF_CGROUP_SOCK_OPS:
1716 ptype = BPF_PROG_TYPE_SOCK_OPS;
1717 break;
1718 case BPF_CGROUP_DEVICE:
1719 ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1720 break;
1721 case BPF_SK_MSG_VERDICT:
1722 return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, NULL);
1723 case BPF_SK_SKB_STREAM_PARSER:
1724 case BPF_SK_SKB_STREAM_VERDICT:
1725 return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, NULL);
1726 case BPF_LIRC_MODE2:
1727 return lirc_prog_detach(attr);
1728 default:
1729 return -EINVAL;
1730 }
1731
1732 return cgroup_bpf_prog_detach(attr, ptype);
1733 }
1734
1735 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
1736
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)1737 static int bpf_prog_query(const union bpf_attr *attr,
1738 union bpf_attr __user *uattr)
1739 {
1740 if (!capable(CAP_NET_ADMIN))
1741 return -EPERM;
1742 if (CHECK_ATTR(BPF_PROG_QUERY))
1743 return -EINVAL;
1744 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
1745 return -EINVAL;
1746
1747 switch (attr->query.attach_type) {
1748 case BPF_CGROUP_INET_INGRESS:
1749 case BPF_CGROUP_INET_EGRESS:
1750 case BPF_CGROUP_INET_SOCK_CREATE:
1751 case BPF_CGROUP_INET4_BIND:
1752 case BPF_CGROUP_INET6_BIND:
1753 case BPF_CGROUP_INET4_POST_BIND:
1754 case BPF_CGROUP_INET6_POST_BIND:
1755 case BPF_CGROUP_INET4_CONNECT:
1756 case BPF_CGROUP_INET6_CONNECT:
1757 case BPF_CGROUP_UDP4_SENDMSG:
1758 case BPF_CGROUP_UDP6_SENDMSG:
1759 case BPF_CGROUP_UDP4_RECVMSG:
1760 case BPF_CGROUP_UDP6_RECVMSG:
1761 case BPF_CGROUP_SOCK_OPS:
1762 case BPF_CGROUP_DEVICE:
1763 break;
1764 case BPF_LIRC_MODE2:
1765 return lirc_prog_query(attr, uattr);
1766 default:
1767 return -EINVAL;
1768 }
1769
1770 return cgroup_bpf_prog_query(attr, uattr);
1771 }
1772
1773 #define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
1774
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)1775 static int bpf_prog_test_run(const union bpf_attr *attr,
1776 union bpf_attr __user *uattr)
1777 {
1778 struct bpf_prog *prog;
1779 int ret = -ENOTSUPP;
1780
1781 if (!capable(CAP_SYS_ADMIN))
1782 return -EPERM;
1783 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
1784 return -EINVAL;
1785
1786 prog = bpf_prog_get(attr->test.prog_fd);
1787 if (IS_ERR(prog))
1788 return PTR_ERR(prog);
1789
1790 if (prog->aux->ops->test_run)
1791 ret = prog->aux->ops->test_run(prog, attr, uattr);
1792
1793 bpf_prog_put(prog);
1794 return ret;
1795 }
1796
1797 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
1798
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)1799 static int bpf_obj_get_next_id(const union bpf_attr *attr,
1800 union bpf_attr __user *uattr,
1801 struct idr *idr,
1802 spinlock_t *lock)
1803 {
1804 u32 next_id = attr->start_id;
1805 int err = 0;
1806
1807 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
1808 return -EINVAL;
1809
1810 if (!capable(CAP_SYS_ADMIN))
1811 return -EPERM;
1812
1813 next_id++;
1814 spin_lock_bh(lock);
1815 if (!idr_get_next(idr, &next_id))
1816 err = -ENOENT;
1817 spin_unlock_bh(lock);
1818
1819 if (!err)
1820 err = put_user(next_id, &uattr->next_id);
1821
1822 return err;
1823 }
1824
1825 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
1826
bpf_prog_get_fd_by_id(const union bpf_attr * attr)1827 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
1828 {
1829 struct bpf_prog *prog;
1830 u32 id = attr->prog_id;
1831 int fd;
1832
1833 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
1834 return -EINVAL;
1835
1836 if (!capable(CAP_SYS_ADMIN))
1837 return -EPERM;
1838
1839 spin_lock_bh(&prog_idr_lock);
1840 prog = idr_find(&prog_idr, id);
1841 if (prog)
1842 prog = bpf_prog_inc_not_zero(prog);
1843 else
1844 prog = ERR_PTR(-ENOENT);
1845 spin_unlock_bh(&prog_idr_lock);
1846
1847 if (IS_ERR(prog))
1848 return PTR_ERR(prog);
1849
1850 fd = bpf_prog_new_fd(prog);
1851 if (fd < 0)
1852 bpf_prog_put(prog);
1853
1854 return fd;
1855 }
1856
1857 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
1858
bpf_map_get_fd_by_id(const union bpf_attr * attr)1859 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
1860 {
1861 struct bpf_map *map;
1862 u32 id = attr->map_id;
1863 int f_flags;
1864 int fd;
1865
1866 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
1867 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
1868 return -EINVAL;
1869
1870 if (!capable(CAP_SYS_ADMIN))
1871 return -EPERM;
1872
1873 f_flags = bpf_get_file_flag(attr->open_flags);
1874 if (f_flags < 0)
1875 return f_flags;
1876
1877 spin_lock_bh(&map_idr_lock);
1878 map = idr_find(&map_idr, id);
1879 if (map)
1880 map = bpf_map_inc_not_zero(map, true);
1881 else
1882 map = ERR_PTR(-ENOENT);
1883 spin_unlock_bh(&map_idr_lock);
1884
1885 if (IS_ERR(map))
1886 return PTR_ERR(map);
1887
1888 fd = bpf_map_new_fd(map, f_flags);
1889 if (fd < 0)
1890 bpf_map_put_with_uref(map);
1891
1892 return fd;
1893 }
1894
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr)1895 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
1896 unsigned long addr)
1897 {
1898 int i;
1899
1900 for (i = 0; i < prog->aux->used_map_cnt; i++)
1901 if (prog->aux->used_maps[i] == (void *)addr)
1902 return prog->aux->used_maps[i];
1903 return NULL;
1904 }
1905
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)1906 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
1907 const struct cred *f_cred)
1908 {
1909 const struct bpf_map *map;
1910 struct bpf_insn *insns;
1911 u64 imm;
1912 int i;
1913
1914 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
1915 GFP_USER);
1916 if (!insns)
1917 return insns;
1918
1919 for (i = 0; i < prog->len; i++) {
1920 if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
1921 insns[i].code = BPF_JMP | BPF_CALL;
1922 insns[i].imm = BPF_FUNC_tail_call;
1923 /* fall-through */
1924 }
1925 if (insns[i].code == (BPF_JMP | BPF_CALL) ||
1926 insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
1927 if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
1928 insns[i].code = BPF_JMP | BPF_CALL;
1929 if (!bpf_dump_raw_ok(f_cred))
1930 insns[i].imm = 0;
1931 continue;
1932 }
1933
1934 if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
1935 continue;
1936
1937 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
1938 map = bpf_map_from_imm(prog, imm);
1939 if (map) {
1940 insns[i].src_reg = BPF_PSEUDO_MAP_FD;
1941 insns[i].imm = map->id;
1942 insns[i + 1].imm = 0;
1943 continue;
1944 }
1945
1946 if (!bpf_dump_raw_ok(f_cred) &&
1947 imm == (unsigned long)prog->aux) {
1948 insns[i].imm = 0;
1949 insns[i + 1].imm = 0;
1950 continue;
1951 }
1952 }
1953
1954 return insns;
1955 }
1956
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)1957 static int bpf_prog_get_info_by_fd(struct file *file,
1958 struct bpf_prog *prog,
1959 const union bpf_attr *attr,
1960 union bpf_attr __user *uattr)
1961 {
1962 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1963 struct bpf_prog_info info;
1964 u32 info_len = attr->info.info_len;
1965 char __user *uinsns;
1966 u32 ulen;
1967 int err;
1968
1969 err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1970 if (err)
1971 return err;
1972 info_len = min_t(u32, sizeof(info), info_len);
1973
1974 memset(&info, 0, sizeof(info));
1975 if (copy_from_user(&info, uinfo, info_len))
1976 return -EFAULT;
1977
1978 info.type = prog->type;
1979 info.id = prog->aux->id;
1980 info.load_time = prog->aux->load_time;
1981 info.created_by_uid = from_kuid_munged(current_user_ns(),
1982 prog->aux->user->uid);
1983 info.gpl_compatible = prog->gpl_compatible;
1984
1985 memcpy(info.tag, prog->tag, sizeof(prog->tag));
1986 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
1987
1988 ulen = info.nr_map_ids;
1989 info.nr_map_ids = prog->aux->used_map_cnt;
1990 ulen = min_t(u32, info.nr_map_ids, ulen);
1991 if (ulen) {
1992 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
1993 u32 i;
1994
1995 for (i = 0; i < ulen; i++)
1996 if (put_user(prog->aux->used_maps[i]->id,
1997 &user_map_ids[i]))
1998 return -EFAULT;
1999 }
2000
2001 if (!capable(CAP_SYS_ADMIN)) {
2002 info.jited_prog_len = 0;
2003 info.xlated_prog_len = 0;
2004 info.nr_jited_ksyms = 0;
2005 info.nr_jited_func_lens = 0;
2006 goto done;
2007 }
2008
2009 ulen = info.xlated_prog_len;
2010 info.xlated_prog_len = bpf_prog_insn_size(prog);
2011 if (info.xlated_prog_len && ulen) {
2012 struct bpf_insn *insns_sanitized;
2013 bool fault;
2014
2015 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
2016 info.xlated_prog_insns = 0;
2017 goto done;
2018 }
2019 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
2020 if (!insns_sanitized)
2021 return -ENOMEM;
2022 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
2023 ulen = min_t(u32, info.xlated_prog_len, ulen);
2024 fault = copy_to_user(uinsns, insns_sanitized, ulen);
2025 kfree(insns_sanitized);
2026 if (fault)
2027 return -EFAULT;
2028 }
2029
2030 if (bpf_prog_is_dev_bound(prog->aux)) {
2031 err = bpf_prog_offload_info_fill(&info, prog);
2032 if (err)
2033 return err;
2034 goto done;
2035 }
2036
2037 /* NOTE: the following code is supposed to be skipped for offload.
2038 * bpf_prog_offload_info_fill() is the place to fill similar fields
2039 * for offload.
2040 */
2041 ulen = info.jited_prog_len;
2042 if (prog->aux->func_cnt) {
2043 u32 i;
2044
2045 info.jited_prog_len = 0;
2046 for (i = 0; i < prog->aux->func_cnt; i++)
2047 info.jited_prog_len += prog->aux->func[i]->jited_len;
2048 } else {
2049 info.jited_prog_len = prog->jited_len;
2050 }
2051
2052 if (info.jited_prog_len && ulen) {
2053 if (bpf_dump_raw_ok(file->f_cred)) {
2054 uinsns = u64_to_user_ptr(info.jited_prog_insns);
2055 ulen = min_t(u32, info.jited_prog_len, ulen);
2056
2057 /* for multi-function programs, copy the JITed
2058 * instructions for all the functions
2059 */
2060 if (prog->aux->func_cnt) {
2061 u32 len, free, i;
2062 u8 *img;
2063
2064 free = ulen;
2065 for (i = 0; i < prog->aux->func_cnt; i++) {
2066 len = prog->aux->func[i]->jited_len;
2067 len = min_t(u32, len, free);
2068 img = (u8 *) prog->aux->func[i]->bpf_func;
2069 if (copy_to_user(uinsns, img, len))
2070 return -EFAULT;
2071 uinsns += len;
2072 free -= len;
2073 if (!free)
2074 break;
2075 }
2076 } else {
2077 if (copy_to_user(uinsns, prog->bpf_func, ulen))
2078 return -EFAULT;
2079 }
2080 } else {
2081 info.jited_prog_insns = 0;
2082 }
2083 }
2084
2085 ulen = info.nr_jited_ksyms;
2086 info.nr_jited_ksyms = prog->aux->func_cnt;
2087 if (info.nr_jited_ksyms && ulen) {
2088 if (bpf_dump_raw_ok(file->f_cred)) {
2089 u64 __user *user_ksyms;
2090 ulong ksym_addr;
2091 u32 i;
2092
2093 /* copy the address of the kernel symbol
2094 * corresponding to each function
2095 */
2096 ulen = min_t(u32, info.nr_jited_ksyms, ulen);
2097 user_ksyms = u64_to_user_ptr(info.jited_ksyms);
2098 for (i = 0; i < ulen; i++) {
2099 ksym_addr = (ulong) prog->aux->func[i]->bpf_func;
2100 ksym_addr &= PAGE_MASK;
2101 if (put_user((u64) ksym_addr, &user_ksyms[i]))
2102 return -EFAULT;
2103 }
2104 } else {
2105 info.jited_ksyms = 0;
2106 }
2107 }
2108
2109 ulen = info.nr_jited_func_lens;
2110 info.nr_jited_func_lens = prog->aux->func_cnt;
2111 if (info.nr_jited_func_lens && ulen) {
2112 if (bpf_dump_raw_ok(file->f_cred)) {
2113 u32 __user *user_lens;
2114 u32 func_len, i;
2115
2116 /* copy the JITed image lengths for each function */
2117 ulen = min_t(u32, info.nr_jited_func_lens, ulen);
2118 user_lens = u64_to_user_ptr(info.jited_func_lens);
2119 for (i = 0; i < ulen; i++) {
2120 func_len = prog->aux->func[i]->jited_len;
2121 if (put_user(func_len, &user_lens[i]))
2122 return -EFAULT;
2123 }
2124 } else {
2125 info.jited_func_lens = 0;
2126 }
2127 }
2128
2129 done:
2130 if (copy_to_user(uinfo, &info, info_len) ||
2131 put_user(info_len, &uattr->info.info_len))
2132 return -EFAULT;
2133
2134 return 0;
2135 }
2136
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)2137 static int bpf_map_get_info_by_fd(struct file *file,
2138 struct bpf_map *map,
2139 const union bpf_attr *attr,
2140 union bpf_attr __user *uattr)
2141 {
2142 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
2143 struct bpf_map_info info;
2144 u32 info_len = attr->info.info_len;
2145 int err;
2146
2147 err = bpf_check_uarg_tail_zero(uinfo, sizeof(info), info_len);
2148 if (err)
2149 return err;
2150 info_len = min_t(u32, sizeof(info), info_len);
2151
2152 memset(&info, 0, sizeof(info));
2153 info.type = map->map_type;
2154 info.id = map->id;
2155 info.key_size = map->key_size;
2156 info.value_size = map->value_size;
2157 info.max_entries = map->max_entries;
2158 info.map_flags = map->map_flags;
2159 memcpy(info.name, map->name, sizeof(map->name));
2160
2161 if (map->btf) {
2162 info.btf_id = btf_id(map->btf);
2163 info.btf_key_type_id = map->btf_key_type_id;
2164 info.btf_value_type_id = map->btf_value_type_id;
2165 }
2166
2167 if (bpf_map_is_dev_bound(map)) {
2168 err = bpf_map_offload_info_fill(&info, map);
2169 if (err)
2170 return err;
2171 }
2172
2173 if (copy_to_user(uinfo, &info, info_len) ||
2174 put_user(info_len, &uattr->info.info_len))
2175 return -EFAULT;
2176
2177 return 0;
2178 }
2179
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)2180 static int bpf_btf_get_info_by_fd(struct file *file,
2181 struct btf *btf,
2182 const union bpf_attr *attr,
2183 union bpf_attr __user *uattr)
2184 {
2185 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
2186 u32 info_len = attr->info.info_len;
2187 int err;
2188
2189 err = bpf_check_uarg_tail_zero(uinfo, sizeof(*uinfo), info_len);
2190 if (err)
2191 return err;
2192
2193 return btf_get_info_by_fd(btf, attr, uattr);
2194 }
2195
2196 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
2197
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)2198 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
2199 union bpf_attr __user *uattr)
2200 {
2201 int ufd = attr->info.bpf_fd;
2202 struct fd f;
2203 int err;
2204
2205 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
2206 return -EINVAL;
2207
2208 f = fdget(ufd);
2209 if (!f.file)
2210 return -EBADFD;
2211
2212 if (f.file->f_op == &bpf_prog_fops)
2213 err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
2214 uattr);
2215 else if (f.file->f_op == &bpf_map_fops)
2216 err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
2217 uattr);
2218 else if (f.file->f_op == &btf_fops)
2219 err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
2220 else
2221 err = -EINVAL;
2222
2223 fdput(f);
2224 return err;
2225 }
2226
2227 #define BPF_BTF_LOAD_LAST_FIELD btf_log_level
2228
bpf_btf_load(const union bpf_attr * attr)2229 static int bpf_btf_load(const union bpf_attr *attr)
2230 {
2231 if (CHECK_ATTR(BPF_BTF_LOAD))
2232 return -EINVAL;
2233
2234 if (!capable(CAP_SYS_ADMIN))
2235 return -EPERM;
2236
2237 return btf_new_fd(attr);
2238 }
2239
2240 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
2241
bpf_btf_get_fd_by_id(const union bpf_attr * attr)2242 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
2243 {
2244 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
2245 return -EINVAL;
2246
2247 if (!capable(CAP_SYS_ADMIN))
2248 return -EPERM;
2249
2250 return btf_get_fd_by_id(attr->btf_id);
2251 }
2252
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)2253 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
2254 union bpf_attr __user *uattr,
2255 u32 prog_id, u32 fd_type,
2256 const char *buf, u64 probe_offset,
2257 u64 probe_addr)
2258 {
2259 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
2260 u32 len = buf ? strlen(buf) : 0, input_len;
2261 int err = 0;
2262
2263 if (put_user(len, &uattr->task_fd_query.buf_len))
2264 return -EFAULT;
2265 input_len = attr->task_fd_query.buf_len;
2266 if (input_len && ubuf) {
2267 if (!len) {
2268 /* nothing to copy, just make ubuf NULL terminated */
2269 char zero = '\0';
2270
2271 if (put_user(zero, ubuf))
2272 return -EFAULT;
2273 } else if (input_len >= len + 1) {
2274 /* ubuf can hold the string with NULL terminator */
2275 if (copy_to_user(ubuf, buf, len + 1))
2276 return -EFAULT;
2277 } else {
2278 /* ubuf cannot hold the string with NULL terminator,
2279 * do a partial copy with NULL terminator.
2280 */
2281 char zero = '\0';
2282
2283 err = -ENOSPC;
2284 if (copy_to_user(ubuf, buf, input_len - 1))
2285 return -EFAULT;
2286 if (put_user(zero, ubuf + input_len - 1))
2287 return -EFAULT;
2288 }
2289 }
2290
2291 if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
2292 put_user(fd_type, &uattr->task_fd_query.fd_type) ||
2293 put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
2294 put_user(probe_addr, &uattr->task_fd_query.probe_addr))
2295 return -EFAULT;
2296
2297 return err;
2298 }
2299
2300 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
2301
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)2302 static int bpf_task_fd_query(const union bpf_attr *attr,
2303 union bpf_attr __user *uattr)
2304 {
2305 pid_t pid = attr->task_fd_query.pid;
2306 u32 fd = attr->task_fd_query.fd;
2307 const struct perf_event *event;
2308 struct files_struct *files;
2309 struct task_struct *task;
2310 struct file *file;
2311 int err;
2312
2313 if (CHECK_ATTR(BPF_TASK_FD_QUERY))
2314 return -EINVAL;
2315
2316 if (!capable(CAP_SYS_ADMIN))
2317 return -EPERM;
2318
2319 if (attr->task_fd_query.flags != 0)
2320 return -EINVAL;
2321
2322 task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
2323 if (!task)
2324 return -ENOENT;
2325
2326 files = get_files_struct(task);
2327 put_task_struct(task);
2328 if (!files)
2329 return -ENOENT;
2330
2331 err = 0;
2332 spin_lock(&files->file_lock);
2333 file = fcheck_files(files, fd);
2334 if (!file)
2335 err = -EBADF;
2336 else
2337 get_file(file);
2338 spin_unlock(&files->file_lock);
2339 put_files_struct(files);
2340
2341 if (err)
2342 goto out;
2343
2344 if (file->f_op == &bpf_raw_tp_fops) {
2345 struct bpf_raw_tracepoint *raw_tp = file->private_data;
2346 struct bpf_raw_event_map *btp = raw_tp->btp;
2347
2348 err = bpf_task_fd_query_copy(attr, uattr,
2349 raw_tp->prog->aux->id,
2350 BPF_FD_TYPE_RAW_TRACEPOINT,
2351 btp->tp->name, 0, 0);
2352 goto put_file;
2353 }
2354
2355 event = perf_get_event(file);
2356 if (!IS_ERR(event)) {
2357 u64 probe_offset, probe_addr;
2358 u32 prog_id, fd_type;
2359 const char *buf;
2360
2361 err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
2362 &buf, &probe_offset,
2363 &probe_addr);
2364 if (!err)
2365 err = bpf_task_fd_query_copy(attr, uattr, prog_id,
2366 fd_type, buf,
2367 probe_offset,
2368 probe_addr);
2369 goto put_file;
2370 }
2371
2372 err = -ENOTSUPP;
2373 put_file:
2374 fput(file);
2375 out:
2376 return err;
2377 }
2378
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)2379 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
2380 {
2381 union bpf_attr attr;
2382 int err;
2383
2384 if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN))
2385 return -EPERM;
2386
2387 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
2388 if (err)
2389 return err;
2390 size = min_t(u32, size, sizeof(attr));
2391
2392 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
2393 memset(&attr, 0, sizeof(attr));
2394 if (copy_from_user(&attr, uattr, size) != 0)
2395 return -EFAULT;
2396
2397 err = security_bpf(cmd, &attr, size);
2398 if (err < 0)
2399 return err;
2400
2401 switch (cmd) {
2402 case BPF_MAP_CREATE:
2403 err = map_create(&attr);
2404 break;
2405 case BPF_MAP_LOOKUP_ELEM:
2406 err = map_lookup_elem(&attr);
2407 break;
2408 case BPF_MAP_UPDATE_ELEM:
2409 err = map_update_elem(&attr);
2410 break;
2411 case BPF_MAP_DELETE_ELEM:
2412 err = map_delete_elem(&attr);
2413 break;
2414 case BPF_MAP_GET_NEXT_KEY:
2415 err = map_get_next_key(&attr);
2416 break;
2417 case BPF_PROG_LOAD:
2418 err = bpf_prog_load(&attr);
2419 break;
2420 case BPF_OBJ_PIN:
2421 err = bpf_obj_pin(&attr);
2422 break;
2423 case BPF_OBJ_GET:
2424 err = bpf_obj_get(&attr);
2425 break;
2426 case BPF_PROG_ATTACH:
2427 err = bpf_prog_attach(&attr);
2428 break;
2429 case BPF_PROG_DETACH:
2430 err = bpf_prog_detach(&attr);
2431 break;
2432 case BPF_PROG_QUERY:
2433 err = bpf_prog_query(&attr, uattr);
2434 break;
2435 case BPF_PROG_TEST_RUN:
2436 err = bpf_prog_test_run(&attr, uattr);
2437 break;
2438 case BPF_PROG_GET_NEXT_ID:
2439 err = bpf_obj_get_next_id(&attr, uattr,
2440 &prog_idr, &prog_idr_lock);
2441 break;
2442 case BPF_MAP_GET_NEXT_ID:
2443 err = bpf_obj_get_next_id(&attr, uattr,
2444 &map_idr, &map_idr_lock);
2445 break;
2446 case BPF_PROG_GET_FD_BY_ID:
2447 err = bpf_prog_get_fd_by_id(&attr);
2448 break;
2449 case BPF_MAP_GET_FD_BY_ID:
2450 err = bpf_map_get_fd_by_id(&attr);
2451 break;
2452 case BPF_OBJ_GET_INFO_BY_FD:
2453 err = bpf_obj_get_info_by_fd(&attr, uattr);
2454 break;
2455 case BPF_RAW_TRACEPOINT_OPEN:
2456 err = bpf_raw_tracepoint_open(&attr);
2457 break;
2458 case BPF_BTF_LOAD:
2459 err = bpf_btf_load(&attr);
2460 break;
2461 case BPF_BTF_GET_FD_BY_ID:
2462 err = bpf_btf_get_fd_by_id(&attr);
2463 break;
2464 case BPF_TASK_FD_QUERY:
2465 err = bpf_task_fd_query(&attr, uattr);
2466 break;
2467 default:
2468 err = -EINVAL;
2469 break;
2470 }
2471
2472 return err;
2473 }
2474