1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 */
4 #include <linux/bpf.h>
5 #include <linux/bpf_trace.h>
6 #include <linux/bpf_lirc.h>
7 #include <linux/bpf_verifier.h>
8 #include <linux/btf.h>
9 #include <linux/syscalls.h>
10 #include <linux/slab.h>
11 #include <linux/sched/signal.h>
12 #include <linux/vmalloc.h>
13 #include <linux/mmzone.h>
14 #include <linux/anon_inodes.h>
15 #include <linux/fdtable.h>
16 #include <linux/file.h>
17 #include <linux/fs.h>
18 #include <linux/license.h>
19 #include <linux/filter.h>
20 #include <linux/kernel.h>
21 #include <linux/idr.h>
22 #include <linux/cred.h>
23 #include <linux/timekeeping.h>
24 #include <linux/ctype.h>
25 #include <linux/nospec.h>
26 #include <linux/audit.h>
27 #include <uapi/linux/btf.h>
28 #include <linux/pgtable.h>
29 #include <linux/bpf_lsm.h>
30 #include <linux/poll.h>
31 #include <linux/bpf-netns.h>
32 #include <linux/rcupdate_trace.h>
33 #include <linux/memcontrol.h>
34
35 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
36 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
37 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
38 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
39 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
40 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
41 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 static DEFINE_IDR(link_idr);
51 static DEFINE_SPINLOCK(link_idr_lock);
52
53 int sysctl_unprivileged_bpf_disabled __read_mostly =
54 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
55
56 static const struct bpf_map_ops * const bpf_map_types[] = {
57 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
58 #define BPF_MAP_TYPE(_id, _ops) \
59 [_id] = &_ops,
60 #define BPF_LINK_TYPE(_id, _name)
61 #include <linux/bpf_types.h>
62 #undef BPF_PROG_TYPE
63 #undef BPF_MAP_TYPE
64 #undef BPF_LINK_TYPE
65 };
66
67 /*
68 * If we're handed a bigger struct than we know of, ensure all the unknown bits
69 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
70 * we don't know about yet.
71 *
72 * There is a ToCToU between this function call and the following
73 * copy_from_user() call. However, this is not a concern since this function is
74 * meant to be a future-proofing of bits.
75 */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)76 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
77 size_t expected_size,
78 size_t actual_size)
79 {
80 int res;
81
82 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
83 return -E2BIG;
84
85 if (actual_size <= expected_size)
86 return 0;
87
88 if (uaddr.is_kernel)
89 res = memchr_inv(uaddr.kernel + expected_size, 0,
90 actual_size - expected_size) == NULL;
91 else
92 res = check_zeroed_user(uaddr.user + expected_size,
93 actual_size - expected_size);
94 if (res < 0)
95 return res;
96 return res ? 0 : -E2BIG;
97 }
98
99 const struct bpf_map_ops bpf_map_offload_ops = {
100 .map_meta_equal = bpf_map_meta_equal,
101 .map_alloc = bpf_map_offload_map_alloc,
102 .map_free = bpf_map_offload_map_free,
103 .map_check_btf = map_check_no_btf,
104 };
105
find_and_alloc_map(union bpf_attr * attr)106 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
107 {
108 const struct bpf_map_ops *ops;
109 u32 type = attr->map_type;
110 struct bpf_map *map;
111 int err;
112
113 if (type >= ARRAY_SIZE(bpf_map_types))
114 return ERR_PTR(-EINVAL);
115 type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
116 ops = bpf_map_types[type];
117 if (!ops)
118 return ERR_PTR(-EINVAL);
119
120 if (ops->map_alloc_check) {
121 err = ops->map_alloc_check(attr);
122 if (err)
123 return ERR_PTR(err);
124 }
125 if (attr->map_ifindex)
126 ops = &bpf_map_offload_ops;
127 map = ops->map_alloc(attr);
128 if (IS_ERR(map))
129 return map;
130 map->ops = ops;
131 map->map_type = type;
132 return map;
133 }
134
bpf_map_write_active_inc(struct bpf_map * map)135 static void bpf_map_write_active_inc(struct bpf_map *map)
136 {
137 atomic64_inc(&map->writecnt);
138 }
139
bpf_map_write_active_dec(struct bpf_map * map)140 static void bpf_map_write_active_dec(struct bpf_map *map)
141 {
142 atomic64_dec(&map->writecnt);
143 }
144
bpf_map_write_active(const struct bpf_map * map)145 bool bpf_map_write_active(const struct bpf_map *map)
146 {
147 return atomic64_read(&map->writecnt) != 0;
148 }
149
bpf_map_value_size(const struct bpf_map * map)150 static u32 bpf_map_value_size(const struct bpf_map *map)
151 {
152 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
153 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
154 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
155 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
156 return round_up(map->value_size, 8) * num_possible_cpus();
157 else if (IS_FD_MAP(map))
158 return sizeof(u32);
159 else
160 return map->value_size;
161 }
162
maybe_wait_bpf_programs(struct bpf_map * map)163 static void maybe_wait_bpf_programs(struct bpf_map *map)
164 {
165 /* Wait for any running BPF programs to complete so that
166 * userspace, when we return to it, knows that all programs
167 * that could be running use the new map value.
168 */
169 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
170 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
171 synchronize_rcu();
172 }
173
bpf_map_update_value(struct bpf_map * map,struct fd f,void * key,void * value,__u64 flags)174 static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
175 void *value, __u64 flags)
176 {
177 int err;
178
179 /* Need to create a kthread, thus must support schedule */
180 if (bpf_map_is_dev_bound(map)) {
181 return bpf_map_offload_update_elem(map, key, value, flags);
182 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
183 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
184 return map->ops->map_update_elem(map, key, value, flags);
185 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
186 map->map_type == BPF_MAP_TYPE_SOCKMAP) {
187 return sock_map_update_elem_sys(map, key, value, flags);
188 } else if (IS_FD_PROG_ARRAY(map)) {
189 return bpf_fd_array_map_update_elem(map, f.file, key, value,
190 flags);
191 }
192
193 bpf_disable_instrumentation();
194 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
195 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
196 err = bpf_percpu_hash_update(map, key, value, flags);
197 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
198 err = bpf_percpu_array_update(map, key, value, flags);
199 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
200 err = bpf_percpu_cgroup_storage_update(map, key, value,
201 flags);
202 } else if (IS_FD_ARRAY(map)) {
203 rcu_read_lock();
204 err = bpf_fd_array_map_update_elem(map, f.file, key, value,
205 flags);
206 rcu_read_unlock();
207 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
208 rcu_read_lock();
209 err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
210 flags);
211 rcu_read_unlock();
212 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
213 /* rcu_read_lock() is not needed */
214 err = bpf_fd_reuseport_array_update_elem(map, key, value,
215 flags);
216 } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
217 map->map_type == BPF_MAP_TYPE_STACK ||
218 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
219 err = map->ops->map_push_elem(map, value, flags);
220 } else {
221 rcu_read_lock();
222 err = map->ops->map_update_elem(map, key, value, flags);
223 rcu_read_unlock();
224 }
225 bpf_enable_instrumentation();
226 maybe_wait_bpf_programs(map);
227
228 return err;
229 }
230
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)231 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
232 __u64 flags)
233 {
234 void *ptr;
235 int err;
236
237 if (bpf_map_is_dev_bound(map))
238 return bpf_map_offload_lookup_elem(map, key, value);
239
240 bpf_disable_instrumentation();
241 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
242 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
243 err = bpf_percpu_hash_copy(map, key, value);
244 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
245 err = bpf_percpu_array_copy(map, key, value);
246 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
247 err = bpf_percpu_cgroup_storage_copy(map, key, value);
248 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
249 err = bpf_stackmap_copy(map, key, value);
250 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
251 err = bpf_fd_array_map_lookup_elem(map, key, value);
252 } else if (IS_FD_HASH(map)) {
253 err = bpf_fd_htab_map_lookup_elem(map, key, value);
254 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
255 err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
256 } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
257 map->map_type == BPF_MAP_TYPE_STACK ||
258 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
259 err = map->ops->map_peek_elem(map, value);
260 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
261 /* struct_ops map requires directly updating "value" */
262 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
263 } else {
264 rcu_read_lock();
265 if (map->ops->map_lookup_elem_sys_only)
266 ptr = map->ops->map_lookup_elem_sys_only(map, key);
267 else
268 ptr = map->ops->map_lookup_elem(map, key);
269 if (IS_ERR(ptr)) {
270 err = PTR_ERR(ptr);
271 } else if (!ptr) {
272 err = -ENOENT;
273 } else {
274 err = 0;
275 if (flags & BPF_F_LOCK)
276 /* lock 'ptr' and copy everything but lock */
277 copy_map_value_locked(map, value, ptr, true);
278 else
279 copy_map_value(map, value, ptr);
280 /* mask lock and timer, since value wasn't zero inited */
281 check_and_init_map_value(map, value);
282 }
283 rcu_read_unlock();
284 }
285
286 bpf_enable_instrumentation();
287 maybe_wait_bpf_programs(map);
288
289 return err;
290 }
291
292 /* Please, do not use this function outside from the map creation path
293 * (e.g. in map update path) without taking care of setting the active
294 * memory cgroup (see at bpf_map_kmalloc_node() for example).
295 */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)296 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
297 {
298 /* We really just want to fail instead of triggering OOM killer
299 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
300 * which is used for lower order allocation requests.
301 *
302 * It has been observed that higher order allocation requests done by
303 * vmalloc with __GFP_NORETRY being set might fail due to not trying
304 * to reclaim memory from the page cache, thus we set
305 * __GFP_RETRY_MAYFAIL to avoid such situations.
306 */
307
308 const gfp_t gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_ACCOUNT;
309 unsigned int flags = 0;
310 unsigned long align = 1;
311 void *area;
312
313 if (size >= SIZE_MAX)
314 return NULL;
315
316 /* kmalloc()'ed memory can't be mmap()'ed */
317 if (mmapable) {
318 BUG_ON(!PAGE_ALIGNED(size));
319 align = SHMLBA;
320 flags = VM_USERMAP;
321 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
322 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
323 numa_node);
324 if (area != NULL)
325 return area;
326 }
327
328 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
329 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
330 flags, numa_node, __builtin_return_address(0));
331 }
332
bpf_map_area_alloc(u64 size,int numa_node)333 void *bpf_map_area_alloc(u64 size, int numa_node)
334 {
335 return __bpf_map_area_alloc(size, numa_node, false);
336 }
337
bpf_map_area_mmapable_alloc(u64 size,int numa_node)338 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
339 {
340 return __bpf_map_area_alloc(size, numa_node, true);
341 }
342
bpf_map_area_free(void * area)343 void bpf_map_area_free(void *area)
344 {
345 kvfree(area);
346 }
347
bpf_map_flags_retain_permanent(u32 flags)348 static u32 bpf_map_flags_retain_permanent(u32 flags)
349 {
350 /* Some map creation flags are not tied to the map object but
351 * rather to the map fd instead, so they have no meaning upon
352 * map object inspection since multiple file descriptors with
353 * different (access) properties can exist here. Thus, given
354 * this has zero meaning for the map itself, lets clear these
355 * from here.
356 */
357 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
358 }
359
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)360 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
361 {
362 map->map_type = attr->map_type;
363 map->key_size = attr->key_size;
364 map->value_size = attr->value_size;
365 map->max_entries = attr->max_entries;
366 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
367 map->numa_node = bpf_map_attr_numa_node(attr);
368 map->map_extra = attr->map_extra;
369 }
370
bpf_map_alloc_id(struct bpf_map * map)371 static int bpf_map_alloc_id(struct bpf_map *map)
372 {
373 int id;
374
375 idr_preload(GFP_KERNEL);
376 spin_lock_bh(&map_idr_lock);
377 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
378 if (id > 0)
379 map->id = id;
380 spin_unlock_bh(&map_idr_lock);
381 idr_preload_end();
382
383 if (WARN_ON_ONCE(!id))
384 return -ENOSPC;
385
386 return id > 0 ? 0 : id;
387 }
388
bpf_map_free_id(struct bpf_map * map,bool do_idr_lock)389 void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
390 {
391 unsigned long flags;
392
393 /* Offloaded maps are removed from the IDR store when their device
394 * disappears - even if someone holds an fd to them they are unusable,
395 * the memory is gone, all ops will fail; they are simply waiting for
396 * refcnt to drop to be freed.
397 */
398 if (!map->id)
399 return;
400
401 if (do_idr_lock)
402 spin_lock_irqsave(&map_idr_lock, flags);
403 else
404 __acquire(&map_idr_lock);
405
406 idr_remove(&map_idr, map->id);
407 map->id = 0;
408
409 if (do_idr_lock)
410 spin_unlock_irqrestore(&map_idr_lock, flags);
411 else
412 __release(&map_idr_lock);
413 }
414
415 #ifdef CONFIG_MEMCG_KMEM
bpf_map_save_memcg(struct bpf_map * map)416 static void bpf_map_save_memcg(struct bpf_map *map)
417 {
418 map->memcg = get_mem_cgroup_from_mm(current->mm);
419 }
420
bpf_map_release_memcg(struct bpf_map * map)421 static void bpf_map_release_memcg(struct bpf_map *map)
422 {
423 mem_cgroup_put(map->memcg);
424 }
425
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)426 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
427 int node)
428 {
429 struct mem_cgroup *old_memcg;
430 void *ptr;
431
432 old_memcg = set_active_memcg(map->memcg);
433 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
434 set_active_memcg(old_memcg);
435
436 return ptr;
437 }
438
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)439 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
440 {
441 struct mem_cgroup *old_memcg;
442 void *ptr;
443
444 old_memcg = set_active_memcg(map->memcg);
445 ptr = kzalloc(size, flags | __GFP_ACCOUNT);
446 set_active_memcg(old_memcg);
447
448 return ptr;
449 }
450
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)451 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
452 size_t align, gfp_t flags)
453 {
454 struct mem_cgroup *old_memcg;
455 void __percpu *ptr;
456
457 old_memcg = set_active_memcg(map->memcg);
458 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
459 set_active_memcg(old_memcg);
460
461 return ptr;
462 }
463
464 #else
bpf_map_save_memcg(struct bpf_map * map)465 static void bpf_map_save_memcg(struct bpf_map *map)
466 {
467 }
468
bpf_map_release_memcg(struct bpf_map * map)469 static void bpf_map_release_memcg(struct bpf_map *map)
470 {
471 }
472 #endif
473
474 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)475 static void bpf_map_free_deferred(struct work_struct *work)
476 {
477 struct bpf_map *map = container_of(work, struct bpf_map, work);
478
479 security_bpf_map_free(map);
480 bpf_map_release_memcg(map);
481 /* implementation dependent freeing */
482 map->ops->map_free(map);
483 }
484
bpf_map_put_uref(struct bpf_map * map)485 static void bpf_map_put_uref(struct bpf_map *map)
486 {
487 if (atomic64_dec_and_test(&map->usercnt)) {
488 if (map->ops->map_release_uref)
489 map->ops->map_release_uref(map);
490 }
491 }
492
493 /* decrement map refcnt and schedule it for freeing via workqueue
494 * (unrelying map implementation ops->map_free() might sleep)
495 */
__bpf_map_put(struct bpf_map * map,bool do_idr_lock)496 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
497 {
498 if (atomic64_dec_and_test(&map->refcnt)) {
499 /* bpf_map_free_id() must be called first */
500 bpf_map_free_id(map, do_idr_lock);
501 btf_put(map->btf);
502 INIT_WORK(&map->work, bpf_map_free_deferred);
503 schedule_work(&map->work);
504 }
505 }
506
bpf_map_put(struct bpf_map * map)507 void bpf_map_put(struct bpf_map *map)
508 {
509 __bpf_map_put(map, true);
510 }
511 EXPORT_SYMBOL_GPL(bpf_map_put);
512
bpf_map_put_with_uref(struct bpf_map * map)513 void bpf_map_put_with_uref(struct bpf_map *map)
514 {
515 bpf_map_put_uref(map);
516 bpf_map_put(map);
517 }
518
bpf_map_release(struct inode * inode,struct file * filp)519 static int bpf_map_release(struct inode *inode, struct file *filp)
520 {
521 struct bpf_map *map = filp->private_data;
522
523 if (map->ops->map_release)
524 map->ops->map_release(map, filp);
525
526 bpf_map_put_with_uref(map);
527 return 0;
528 }
529
map_get_sys_perms(struct bpf_map * map,struct fd f)530 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
531 {
532 fmode_t mode = f.file->f_mode;
533
534 /* Our file permissions may have been overridden by global
535 * map permissions facing syscall side.
536 */
537 if (READ_ONCE(map->frozen))
538 mode &= ~FMODE_CAN_WRITE;
539 return mode;
540 }
541
542 #ifdef CONFIG_PROC_FS
543 /* Provides an approximation of the map's memory footprint.
544 * Used only to provide a backward compatibility and display
545 * a reasonable "memlock" info.
546 */
bpf_map_memory_footprint(const struct bpf_map * map)547 static unsigned long bpf_map_memory_footprint(const struct bpf_map *map)
548 {
549 unsigned long size;
550
551 size = round_up(map->key_size + bpf_map_value_size(map), 8);
552
553 return round_up(map->max_entries * size, PAGE_SIZE);
554 }
555
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)556 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
557 {
558 const struct bpf_map *map = filp->private_data;
559 const struct bpf_array *array;
560 u32 type = 0, jited = 0;
561
562 if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
563 array = container_of(map, struct bpf_array, map);
564 spin_lock(&array->aux->owner.lock);
565 type = array->aux->owner.type;
566 jited = array->aux->owner.jited;
567 spin_unlock(&array->aux->owner.lock);
568 }
569
570 seq_printf(m,
571 "map_type:\t%u\n"
572 "key_size:\t%u\n"
573 "value_size:\t%u\n"
574 "max_entries:\t%u\n"
575 "map_flags:\t%#x\n"
576 "map_extra:\t%#llx\n"
577 "memlock:\t%lu\n"
578 "map_id:\t%u\n"
579 "frozen:\t%u\n",
580 map->map_type,
581 map->key_size,
582 map->value_size,
583 map->max_entries,
584 map->map_flags,
585 (unsigned long long)map->map_extra,
586 bpf_map_memory_footprint(map),
587 map->id,
588 READ_ONCE(map->frozen));
589 if (type) {
590 seq_printf(m, "owner_prog_type:\t%u\n", type);
591 seq_printf(m, "owner_jited:\t%u\n", jited);
592 }
593 }
594 #endif
595
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)596 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
597 loff_t *ppos)
598 {
599 /* We need this handler such that alloc_file() enables
600 * f_mode with FMODE_CAN_READ.
601 */
602 return -EINVAL;
603 }
604
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)605 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
606 size_t siz, loff_t *ppos)
607 {
608 /* We need this handler such that alloc_file() enables
609 * f_mode with FMODE_CAN_WRITE.
610 */
611 return -EINVAL;
612 }
613
614 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)615 static void bpf_map_mmap_open(struct vm_area_struct *vma)
616 {
617 struct bpf_map *map = vma->vm_file->private_data;
618
619 if (vma->vm_flags & VM_MAYWRITE)
620 bpf_map_write_active_inc(map);
621 }
622
623 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)624 static void bpf_map_mmap_close(struct vm_area_struct *vma)
625 {
626 struct bpf_map *map = vma->vm_file->private_data;
627
628 if (vma->vm_flags & VM_MAYWRITE)
629 bpf_map_write_active_dec(map);
630 }
631
632 static const struct vm_operations_struct bpf_map_default_vmops = {
633 .open = bpf_map_mmap_open,
634 .close = bpf_map_mmap_close,
635 };
636
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)637 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
638 {
639 struct bpf_map *map = filp->private_data;
640 int err;
641
642 if (!map->ops->map_mmap || map_value_has_spin_lock(map) ||
643 map_value_has_timer(map))
644 return -ENOTSUPP;
645
646 if (!(vma->vm_flags & VM_SHARED))
647 return -EINVAL;
648
649 mutex_lock(&map->freeze_mutex);
650
651 if (vma->vm_flags & VM_WRITE) {
652 if (map->frozen) {
653 err = -EPERM;
654 goto out;
655 }
656 /* map is meant to be read-only, so do not allow mapping as
657 * writable, because it's possible to leak a writable page
658 * reference and allows user-space to still modify it after
659 * freezing, while verifier will assume contents do not change
660 */
661 if (map->map_flags & BPF_F_RDONLY_PROG) {
662 err = -EACCES;
663 goto out;
664 }
665 }
666
667 /* set default open/close callbacks */
668 vma->vm_ops = &bpf_map_default_vmops;
669 vma->vm_private_data = map;
670 vma->vm_flags &= ~VM_MAYEXEC;
671 if (!(vma->vm_flags & VM_WRITE))
672 /* disallow re-mapping with PROT_WRITE */
673 vma->vm_flags &= ~VM_MAYWRITE;
674
675 err = map->ops->map_mmap(map, vma);
676 if (err)
677 goto out;
678
679 if (vma->vm_flags & VM_MAYWRITE)
680 bpf_map_write_active_inc(map);
681 out:
682 mutex_unlock(&map->freeze_mutex);
683 return err;
684 }
685
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)686 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
687 {
688 struct bpf_map *map = filp->private_data;
689
690 if (map->ops->map_poll)
691 return map->ops->map_poll(map, filp, pts);
692
693 return EPOLLERR;
694 }
695
696 const struct file_operations bpf_map_fops = {
697 #ifdef CONFIG_PROC_FS
698 .show_fdinfo = bpf_map_show_fdinfo,
699 #endif
700 .release = bpf_map_release,
701 .read = bpf_dummy_read,
702 .write = bpf_dummy_write,
703 .mmap = bpf_map_mmap,
704 .poll = bpf_map_poll,
705 };
706
bpf_map_new_fd(struct bpf_map * map,int flags)707 int bpf_map_new_fd(struct bpf_map *map, int flags)
708 {
709 int ret;
710
711 ret = security_bpf_map(map, OPEN_FMODE(flags));
712 if (ret < 0)
713 return ret;
714
715 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
716 flags | O_CLOEXEC);
717 }
718
bpf_get_file_flag(int flags)719 int bpf_get_file_flag(int flags)
720 {
721 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
722 return -EINVAL;
723 if (flags & BPF_F_RDONLY)
724 return O_RDONLY;
725 if (flags & BPF_F_WRONLY)
726 return O_WRONLY;
727 return O_RDWR;
728 }
729
730 /* helper macro to check that unused fields 'union bpf_attr' are zero */
731 #define CHECK_ATTR(CMD) \
732 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
733 sizeof(attr->CMD##_LAST_FIELD), 0, \
734 sizeof(*attr) - \
735 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
736 sizeof(attr->CMD##_LAST_FIELD)) != NULL
737
738 /* dst and src must have at least "size" number of bytes.
739 * Return strlen on success and < 0 on error.
740 */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)741 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
742 {
743 const char *end = src + size;
744 const char *orig_src = src;
745
746 memset(dst, 0, size);
747 /* Copy all isalnum(), '_' and '.' chars. */
748 while (src < end && *src) {
749 if (!isalnum(*src) &&
750 *src != '_' && *src != '.')
751 return -EINVAL;
752 *dst++ = *src++;
753 }
754
755 /* No '\0' found in "size" number of bytes */
756 if (src == end)
757 return -EINVAL;
758
759 return src - orig_src;
760 }
761
map_check_no_btf(const struct bpf_map * map,const struct btf * btf,const struct btf_type * key_type,const struct btf_type * value_type)762 int map_check_no_btf(const struct bpf_map *map,
763 const struct btf *btf,
764 const struct btf_type *key_type,
765 const struct btf_type *value_type)
766 {
767 return -ENOTSUPP;
768 }
769
map_check_btf(struct bpf_map * map,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)770 static int map_check_btf(struct bpf_map *map, const struct btf *btf,
771 u32 btf_key_id, u32 btf_value_id)
772 {
773 const struct btf_type *key_type, *value_type;
774 u32 key_size, value_size;
775 int ret = 0;
776
777 /* Some maps allow key to be unspecified. */
778 if (btf_key_id) {
779 key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
780 if (!key_type || key_size != map->key_size)
781 return -EINVAL;
782 } else {
783 key_type = btf_type_by_id(btf, 0);
784 if (!map->ops->map_check_btf)
785 return -EINVAL;
786 }
787
788 value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
789 if (!value_type || value_size != map->value_size)
790 return -EINVAL;
791
792 map->spin_lock_off = btf_find_spin_lock(btf, value_type);
793
794 if (map_value_has_spin_lock(map)) {
795 if (map->map_flags & BPF_F_RDONLY_PROG)
796 return -EACCES;
797 if (map->map_type != BPF_MAP_TYPE_HASH &&
798 map->map_type != BPF_MAP_TYPE_ARRAY &&
799 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
800 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
801 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
802 map->map_type != BPF_MAP_TYPE_TASK_STORAGE)
803 return -ENOTSUPP;
804 if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
805 map->value_size) {
806 WARN_ONCE(1,
807 "verifier bug spin_lock_off %d value_size %d\n",
808 map->spin_lock_off, map->value_size);
809 return -EFAULT;
810 }
811 }
812
813 map->timer_off = btf_find_timer(btf, value_type);
814 if (map_value_has_timer(map)) {
815 if (map->map_flags & BPF_F_RDONLY_PROG)
816 return -EACCES;
817 if (map->map_type != BPF_MAP_TYPE_HASH &&
818 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
819 map->map_type != BPF_MAP_TYPE_ARRAY)
820 return -EOPNOTSUPP;
821 }
822
823 if (map->ops->map_check_btf)
824 ret = map->ops->map_check_btf(map, btf, key_type, value_type);
825
826 return ret;
827 }
828
829 #define BPF_MAP_CREATE_LAST_FIELD map_extra
830 /* called via syscall */
map_create(union bpf_attr * attr)831 static int map_create(union bpf_attr *attr)
832 {
833 int numa_node = bpf_map_attr_numa_node(attr);
834 struct bpf_map *map;
835 int f_flags;
836 int err;
837
838 err = CHECK_ATTR(BPF_MAP_CREATE);
839 if (err)
840 return -EINVAL;
841
842 if (attr->btf_vmlinux_value_type_id) {
843 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
844 attr->btf_key_type_id || attr->btf_value_type_id)
845 return -EINVAL;
846 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
847 return -EINVAL;
848 }
849
850 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
851 attr->map_extra != 0)
852 return -EINVAL;
853
854 f_flags = bpf_get_file_flag(attr->map_flags);
855 if (f_flags < 0)
856 return f_flags;
857
858 if (numa_node != NUMA_NO_NODE &&
859 ((unsigned int)numa_node >= nr_node_ids ||
860 !node_online(numa_node)))
861 return -EINVAL;
862
863 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
864 map = find_and_alloc_map(attr);
865 if (IS_ERR(map))
866 return PTR_ERR(map);
867
868 err = bpf_obj_name_cpy(map->name, attr->map_name,
869 sizeof(attr->map_name));
870 if (err < 0)
871 goto free_map;
872
873 atomic64_set(&map->refcnt, 1);
874 atomic64_set(&map->usercnt, 1);
875 mutex_init(&map->freeze_mutex);
876
877 map->spin_lock_off = -EINVAL;
878 map->timer_off = -EINVAL;
879 if (attr->btf_key_type_id || attr->btf_value_type_id ||
880 /* Even the map's value is a kernel's struct,
881 * the bpf_prog.o must have BTF to begin with
882 * to figure out the corresponding kernel's
883 * counter part. Thus, attr->btf_fd has
884 * to be valid also.
885 */
886 attr->btf_vmlinux_value_type_id) {
887 struct btf *btf;
888
889 btf = btf_get_by_fd(attr->btf_fd);
890 if (IS_ERR(btf)) {
891 err = PTR_ERR(btf);
892 goto free_map;
893 }
894 if (btf_is_kernel(btf)) {
895 btf_put(btf);
896 err = -EACCES;
897 goto free_map;
898 }
899 map->btf = btf;
900
901 if (attr->btf_value_type_id) {
902 err = map_check_btf(map, btf, attr->btf_key_type_id,
903 attr->btf_value_type_id);
904 if (err)
905 goto free_map;
906 }
907
908 map->btf_key_type_id = attr->btf_key_type_id;
909 map->btf_value_type_id = attr->btf_value_type_id;
910 map->btf_vmlinux_value_type_id =
911 attr->btf_vmlinux_value_type_id;
912 }
913
914 err = security_bpf_map_alloc(map);
915 if (err)
916 goto free_map;
917
918 err = bpf_map_alloc_id(map);
919 if (err)
920 goto free_map_sec;
921
922 bpf_map_save_memcg(map);
923
924 err = bpf_map_new_fd(map, f_flags);
925 if (err < 0) {
926 /* failed to allocate fd.
927 * bpf_map_put_with_uref() is needed because the above
928 * bpf_map_alloc_id() has published the map
929 * to the userspace and the userspace may
930 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
931 */
932 bpf_map_put_with_uref(map);
933 return err;
934 }
935
936 return err;
937
938 free_map_sec:
939 security_bpf_map_free(map);
940 free_map:
941 btf_put(map->btf);
942 map->ops->map_free(map);
943 return err;
944 }
945
946 /* if error is returned, fd is released.
947 * On success caller should complete fd access with matching fdput()
948 */
__bpf_map_get(struct fd f)949 struct bpf_map *__bpf_map_get(struct fd f)
950 {
951 if (!f.file)
952 return ERR_PTR(-EBADF);
953 if (f.file->f_op != &bpf_map_fops) {
954 fdput(f);
955 return ERR_PTR(-EINVAL);
956 }
957
958 return f.file->private_data;
959 }
960
bpf_map_inc(struct bpf_map * map)961 void bpf_map_inc(struct bpf_map *map)
962 {
963 atomic64_inc(&map->refcnt);
964 }
965 EXPORT_SYMBOL_GPL(bpf_map_inc);
966
bpf_map_inc_with_uref(struct bpf_map * map)967 void bpf_map_inc_with_uref(struct bpf_map *map)
968 {
969 atomic64_inc(&map->refcnt);
970 atomic64_inc(&map->usercnt);
971 }
972 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
973
bpf_map_get(u32 ufd)974 struct bpf_map *bpf_map_get(u32 ufd)
975 {
976 struct fd f = fdget(ufd);
977 struct bpf_map *map;
978
979 map = __bpf_map_get(f);
980 if (IS_ERR(map))
981 return map;
982
983 bpf_map_inc(map);
984 fdput(f);
985
986 return map;
987 }
988
bpf_map_get_with_uref(u32 ufd)989 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
990 {
991 struct fd f = fdget(ufd);
992 struct bpf_map *map;
993
994 map = __bpf_map_get(f);
995 if (IS_ERR(map))
996 return map;
997
998 bpf_map_inc_with_uref(map);
999 fdput(f);
1000
1001 return map;
1002 }
1003
1004 /* map_idr_lock should have been held */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1005 static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1006 {
1007 int refold;
1008
1009 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1010 if (!refold)
1011 return ERR_PTR(-ENOENT);
1012 if (uref)
1013 atomic64_inc(&map->usercnt);
1014
1015 return map;
1016 }
1017
bpf_map_inc_not_zero(struct bpf_map * map)1018 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1019 {
1020 spin_lock_bh(&map_idr_lock);
1021 map = __bpf_map_inc_not_zero(map, false);
1022 spin_unlock_bh(&map_idr_lock);
1023
1024 return map;
1025 }
1026 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1027
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1028 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1029 {
1030 return -ENOTSUPP;
1031 }
1032
__bpf_copy_key(void __user * ukey,u64 key_size)1033 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1034 {
1035 if (key_size)
1036 return vmemdup_user(ukey, key_size);
1037
1038 if (ukey)
1039 return ERR_PTR(-EINVAL);
1040
1041 return NULL;
1042 }
1043
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1044 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1045 {
1046 if (key_size)
1047 return kvmemdup_bpfptr(ukey, key_size);
1048
1049 if (!bpfptr_is_null(ukey))
1050 return ERR_PTR(-EINVAL);
1051
1052 return NULL;
1053 }
1054
1055 /* last field in 'union bpf_attr' used by this command */
1056 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1057
map_lookup_elem(union bpf_attr * attr)1058 static int map_lookup_elem(union bpf_attr *attr)
1059 {
1060 void __user *ukey = u64_to_user_ptr(attr->key);
1061 void __user *uvalue = u64_to_user_ptr(attr->value);
1062 int ufd = attr->map_fd;
1063 struct bpf_map *map;
1064 void *key, *value;
1065 u32 value_size;
1066 struct fd f;
1067 int err;
1068
1069 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1070 return -EINVAL;
1071
1072 if (attr->flags & ~BPF_F_LOCK)
1073 return -EINVAL;
1074
1075 f = fdget(ufd);
1076 map = __bpf_map_get(f);
1077 if (IS_ERR(map))
1078 return PTR_ERR(map);
1079 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1080 err = -EPERM;
1081 goto err_put;
1082 }
1083
1084 if ((attr->flags & BPF_F_LOCK) &&
1085 !map_value_has_spin_lock(map)) {
1086 err = -EINVAL;
1087 goto err_put;
1088 }
1089
1090 key = __bpf_copy_key(ukey, map->key_size);
1091 if (IS_ERR(key)) {
1092 err = PTR_ERR(key);
1093 goto err_put;
1094 }
1095
1096 value_size = bpf_map_value_size(map);
1097
1098 err = -ENOMEM;
1099 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1100 if (!value)
1101 goto free_key;
1102
1103 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1104 if (copy_from_user(value, uvalue, value_size))
1105 err = -EFAULT;
1106 else
1107 err = bpf_map_copy_value(map, key, value, attr->flags);
1108 goto free_value;
1109 }
1110
1111 err = bpf_map_copy_value(map, key, value, attr->flags);
1112 if (err)
1113 goto free_value;
1114
1115 err = -EFAULT;
1116 if (copy_to_user(uvalue, value, value_size) != 0)
1117 goto free_value;
1118
1119 err = 0;
1120
1121 free_value:
1122 kvfree(value);
1123 free_key:
1124 kvfree(key);
1125 err_put:
1126 fdput(f);
1127 return err;
1128 }
1129
1130
1131 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1132
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1133 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1134 {
1135 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1136 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1137 int ufd = attr->map_fd;
1138 struct bpf_map *map;
1139 void *key, *value;
1140 u32 value_size;
1141 struct fd f;
1142 int err;
1143
1144 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1145 return -EINVAL;
1146
1147 f = fdget(ufd);
1148 map = __bpf_map_get(f);
1149 if (IS_ERR(map))
1150 return PTR_ERR(map);
1151 bpf_map_write_active_inc(map);
1152 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1153 err = -EPERM;
1154 goto err_put;
1155 }
1156
1157 if ((attr->flags & BPF_F_LOCK) &&
1158 !map_value_has_spin_lock(map)) {
1159 err = -EINVAL;
1160 goto err_put;
1161 }
1162
1163 key = ___bpf_copy_key(ukey, map->key_size);
1164 if (IS_ERR(key)) {
1165 err = PTR_ERR(key);
1166 goto err_put;
1167 }
1168
1169 value_size = bpf_map_value_size(map);
1170
1171 err = -ENOMEM;
1172 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1173 if (!value)
1174 goto free_key;
1175
1176 err = -EFAULT;
1177 if (copy_from_bpfptr(value, uvalue, value_size) != 0)
1178 goto free_value;
1179
1180 err = bpf_map_update_value(map, f, key, value, attr->flags);
1181
1182 free_value:
1183 kvfree(value);
1184 free_key:
1185 kvfree(key);
1186 err_put:
1187 bpf_map_write_active_dec(map);
1188 fdput(f);
1189 return err;
1190 }
1191
1192 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1193
map_delete_elem(union bpf_attr * attr)1194 static int map_delete_elem(union bpf_attr *attr)
1195 {
1196 void __user *ukey = u64_to_user_ptr(attr->key);
1197 int ufd = attr->map_fd;
1198 struct bpf_map *map;
1199 struct fd f;
1200 void *key;
1201 int err;
1202
1203 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1204 return -EINVAL;
1205
1206 f = fdget(ufd);
1207 map = __bpf_map_get(f);
1208 if (IS_ERR(map))
1209 return PTR_ERR(map);
1210 bpf_map_write_active_inc(map);
1211 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1212 err = -EPERM;
1213 goto err_put;
1214 }
1215
1216 key = __bpf_copy_key(ukey, map->key_size);
1217 if (IS_ERR(key)) {
1218 err = PTR_ERR(key);
1219 goto err_put;
1220 }
1221
1222 if (bpf_map_is_dev_bound(map)) {
1223 err = bpf_map_offload_delete_elem(map, key);
1224 goto out;
1225 } else if (IS_FD_PROG_ARRAY(map) ||
1226 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1227 /* These maps require sleepable context */
1228 err = map->ops->map_delete_elem(map, key);
1229 goto out;
1230 }
1231
1232 bpf_disable_instrumentation();
1233 rcu_read_lock();
1234 err = map->ops->map_delete_elem(map, key);
1235 rcu_read_unlock();
1236 bpf_enable_instrumentation();
1237 maybe_wait_bpf_programs(map);
1238 out:
1239 kvfree(key);
1240 err_put:
1241 bpf_map_write_active_dec(map);
1242 fdput(f);
1243 return err;
1244 }
1245
1246 /* last field in 'union bpf_attr' used by this command */
1247 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1248
map_get_next_key(union bpf_attr * attr)1249 static int map_get_next_key(union bpf_attr *attr)
1250 {
1251 void __user *ukey = u64_to_user_ptr(attr->key);
1252 void __user *unext_key = u64_to_user_ptr(attr->next_key);
1253 int ufd = attr->map_fd;
1254 struct bpf_map *map;
1255 void *key, *next_key;
1256 struct fd f;
1257 int err;
1258
1259 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1260 return -EINVAL;
1261
1262 f = fdget(ufd);
1263 map = __bpf_map_get(f);
1264 if (IS_ERR(map))
1265 return PTR_ERR(map);
1266 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1267 err = -EPERM;
1268 goto err_put;
1269 }
1270
1271 if (ukey) {
1272 key = __bpf_copy_key(ukey, map->key_size);
1273 if (IS_ERR(key)) {
1274 err = PTR_ERR(key);
1275 goto err_put;
1276 }
1277 } else {
1278 key = NULL;
1279 }
1280
1281 err = -ENOMEM;
1282 next_key = kvmalloc(map->key_size, GFP_USER);
1283 if (!next_key)
1284 goto free_key;
1285
1286 if (bpf_map_is_dev_bound(map)) {
1287 err = bpf_map_offload_get_next_key(map, key, next_key);
1288 goto out;
1289 }
1290
1291 rcu_read_lock();
1292 err = map->ops->map_get_next_key(map, key, next_key);
1293 rcu_read_unlock();
1294 out:
1295 if (err)
1296 goto free_next_key;
1297
1298 err = -EFAULT;
1299 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1300 goto free_next_key;
1301
1302 err = 0;
1303
1304 free_next_key:
1305 kvfree(next_key);
1306 free_key:
1307 kvfree(key);
1308 err_put:
1309 fdput(f);
1310 return err;
1311 }
1312
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1313 int generic_map_delete_batch(struct bpf_map *map,
1314 const union bpf_attr *attr,
1315 union bpf_attr __user *uattr)
1316 {
1317 void __user *keys = u64_to_user_ptr(attr->batch.keys);
1318 u32 cp, max_count;
1319 int err = 0;
1320 void *key;
1321
1322 if (attr->batch.elem_flags & ~BPF_F_LOCK)
1323 return -EINVAL;
1324
1325 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1326 !map_value_has_spin_lock(map)) {
1327 return -EINVAL;
1328 }
1329
1330 max_count = attr->batch.count;
1331 if (!max_count)
1332 return 0;
1333
1334 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1335 if (!key)
1336 return -ENOMEM;
1337
1338 for (cp = 0; cp < max_count; cp++) {
1339 err = -EFAULT;
1340 if (copy_from_user(key, keys + cp * map->key_size,
1341 map->key_size))
1342 break;
1343
1344 if (bpf_map_is_dev_bound(map)) {
1345 err = bpf_map_offload_delete_elem(map, key);
1346 break;
1347 }
1348
1349 bpf_disable_instrumentation();
1350 rcu_read_lock();
1351 err = map->ops->map_delete_elem(map, key);
1352 rcu_read_unlock();
1353 bpf_enable_instrumentation();
1354 maybe_wait_bpf_programs(map);
1355 if (err)
1356 break;
1357 }
1358 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1359 err = -EFAULT;
1360
1361 kvfree(key);
1362 return err;
1363 }
1364
generic_map_update_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1365 int generic_map_update_batch(struct bpf_map *map,
1366 const union bpf_attr *attr,
1367 union bpf_attr __user *uattr)
1368 {
1369 void __user *values = u64_to_user_ptr(attr->batch.values);
1370 void __user *keys = u64_to_user_ptr(attr->batch.keys);
1371 u32 value_size, cp, max_count;
1372 int ufd = attr->batch.map_fd;
1373 void *key, *value;
1374 struct fd f;
1375 int err = 0;
1376
1377 if (attr->batch.elem_flags & ~BPF_F_LOCK)
1378 return -EINVAL;
1379
1380 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1381 !map_value_has_spin_lock(map)) {
1382 return -EINVAL;
1383 }
1384
1385 value_size = bpf_map_value_size(map);
1386
1387 max_count = attr->batch.count;
1388 if (!max_count)
1389 return 0;
1390
1391 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1392 if (!key)
1393 return -ENOMEM;
1394
1395 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1396 if (!value) {
1397 kvfree(key);
1398 return -ENOMEM;
1399 }
1400
1401 f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */
1402 for (cp = 0; cp < max_count; cp++) {
1403 err = -EFAULT;
1404 if (copy_from_user(key, keys + cp * map->key_size,
1405 map->key_size) ||
1406 copy_from_user(value, values + cp * value_size, value_size))
1407 break;
1408
1409 err = bpf_map_update_value(map, f, key, value,
1410 attr->batch.elem_flags);
1411
1412 if (err)
1413 break;
1414 }
1415
1416 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1417 err = -EFAULT;
1418
1419 kvfree(value);
1420 kvfree(key);
1421 fdput(f);
1422 return err;
1423 }
1424
1425 #define MAP_LOOKUP_RETRIES 3
1426
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1427 int generic_map_lookup_batch(struct bpf_map *map,
1428 const union bpf_attr *attr,
1429 union bpf_attr __user *uattr)
1430 {
1431 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
1432 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1433 void __user *values = u64_to_user_ptr(attr->batch.values);
1434 void __user *keys = u64_to_user_ptr(attr->batch.keys);
1435 void *buf, *buf_prevkey, *prev_key, *key, *value;
1436 int err, retry = MAP_LOOKUP_RETRIES;
1437 u32 value_size, cp, max_count;
1438
1439 if (attr->batch.elem_flags & ~BPF_F_LOCK)
1440 return -EINVAL;
1441
1442 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1443 !map_value_has_spin_lock(map))
1444 return -EINVAL;
1445
1446 value_size = bpf_map_value_size(map);
1447
1448 max_count = attr->batch.count;
1449 if (!max_count)
1450 return 0;
1451
1452 if (put_user(0, &uattr->batch.count))
1453 return -EFAULT;
1454
1455 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1456 if (!buf_prevkey)
1457 return -ENOMEM;
1458
1459 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
1460 if (!buf) {
1461 kvfree(buf_prevkey);
1462 return -ENOMEM;
1463 }
1464
1465 err = -EFAULT;
1466 prev_key = NULL;
1467 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
1468 goto free_buf;
1469 key = buf;
1470 value = key + map->key_size;
1471 if (ubatch)
1472 prev_key = buf_prevkey;
1473
1474 for (cp = 0; cp < max_count;) {
1475 rcu_read_lock();
1476 err = map->ops->map_get_next_key(map, prev_key, key);
1477 rcu_read_unlock();
1478 if (err)
1479 break;
1480 err = bpf_map_copy_value(map, key, value,
1481 attr->batch.elem_flags);
1482
1483 if (err == -ENOENT) {
1484 if (retry) {
1485 retry--;
1486 continue;
1487 }
1488 err = -EINTR;
1489 break;
1490 }
1491
1492 if (err)
1493 goto free_buf;
1494
1495 if (copy_to_user(keys + cp * map->key_size, key,
1496 map->key_size)) {
1497 err = -EFAULT;
1498 goto free_buf;
1499 }
1500 if (copy_to_user(values + cp * value_size, value, value_size)) {
1501 err = -EFAULT;
1502 goto free_buf;
1503 }
1504
1505 if (!prev_key)
1506 prev_key = buf_prevkey;
1507
1508 swap(prev_key, key);
1509 retry = MAP_LOOKUP_RETRIES;
1510 cp++;
1511 }
1512
1513 if (err == -EFAULT)
1514 goto free_buf;
1515
1516 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
1517 (cp && copy_to_user(uobatch, prev_key, map->key_size))))
1518 err = -EFAULT;
1519
1520 free_buf:
1521 kvfree(buf_prevkey);
1522 kvfree(buf);
1523 return err;
1524 }
1525
1526 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
1527
map_lookup_and_delete_elem(union bpf_attr * attr)1528 static int map_lookup_and_delete_elem(union bpf_attr *attr)
1529 {
1530 void __user *ukey = u64_to_user_ptr(attr->key);
1531 void __user *uvalue = u64_to_user_ptr(attr->value);
1532 int ufd = attr->map_fd;
1533 struct bpf_map *map;
1534 void *key, *value;
1535 u32 value_size;
1536 struct fd f;
1537 int err;
1538
1539 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
1540 return -EINVAL;
1541
1542 if (attr->flags & ~BPF_F_LOCK)
1543 return -EINVAL;
1544
1545 f = fdget(ufd);
1546 map = __bpf_map_get(f);
1547 if (IS_ERR(map))
1548 return PTR_ERR(map);
1549 bpf_map_write_active_inc(map);
1550 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
1551 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1552 err = -EPERM;
1553 goto err_put;
1554 }
1555
1556 if (attr->flags &&
1557 (map->map_type == BPF_MAP_TYPE_QUEUE ||
1558 map->map_type == BPF_MAP_TYPE_STACK)) {
1559 err = -EINVAL;
1560 goto err_put;
1561 }
1562
1563 if ((attr->flags & BPF_F_LOCK) &&
1564 !map_value_has_spin_lock(map)) {
1565 err = -EINVAL;
1566 goto err_put;
1567 }
1568
1569 key = __bpf_copy_key(ukey, map->key_size);
1570 if (IS_ERR(key)) {
1571 err = PTR_ERR(key);
1572 goto err_put;
1573 }
1574
1575 value_size = bpf_map_value_size(map);
1576
1577 err = -ENOMEM;
1578 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1579 if (!value)
1580 goto free_key;
1581
1582 err = -ENOTSUPP;
1583 if (map->map_type == BPF_MAP_TYPE_QUEUE ||
1584 map->map_type == BPF_MAP_TYPE_STACK) {
1585 err = map->ops->map_pop_elem(map, value);
1586 } else if (map->map_type == BPF_MAP_TYPE_HASH ||
1587 map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
1588 map->map_type == BPF_MAP_TYPE_LRU_HASH ||
1589 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
1590 if (!bpf_map_is_dev_bound(map)) {
1591 bpf_disable_instrumentation();
1592 rcu_read_lock();
1593 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
1594 rcu_read_unlock();
1595 bpf_enable_instrumentation();
1596 }
1597 }
1598
1599 if (err)
1600 goto free_value;
1601
1602 if (copy_to_user(uvalue, value, value_size) != 0) {
1603 err = -EFAULT;
1604 goto free_value;
1605 }
1606
1607 err = 0;
1608
1609 free_value:
1610 kvfree(value);
1611 free_key:
1612 kvfree(key);
1613 err_put:
1614 bpf_map_write_active_dec(map);
1615 fdput(f);
1616 return err;
1617 }
1618
1619 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
1620
map_freeze(const union bpf_attr * attr)1621 static int map_freeze(const union bpf_attr *attr)
1622 {
1623 int err = 0, ufd = attr->map_fd;
1624 struct bpf_map *map;
1625 struct fd f;
1626
1627 if (CHECK_ATTR(BPF_MAP_FREEZE))
1628 return -EINVAL;
1629
1630 f = fdget(ufd);
1631 map = __bpf_map_get(f);
1632 if (IS_ERR(map))
1633 return PTR_ERR(map);
1634
1635 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS ||
1636 map_value_has_timer(map)) {
1637 fdput(f);
1638 return -ENOTSUPP;
1639 }
1640
1641 mutex_lock(&map->freeze_mutex);
1642 if (bpf_map_write_active(map)) {
1643 err = -EBUSY;
1644 goto err_put;
1645 }
1646 if (READ_ONCE(map->frozen)) {
1647 err = -EBUSY;
1648 goto err_put;
1649 }
1650 if (!bpf_capable()) {
1651 err = -EPERM;
1652 goto err_put;
1653 }
1654
1655 WRITE_ONCE(map->frozen, true);
1656 err_put:
1657 mutex_unlock(&map->freeze_mutex);
1658 fdput(f);
1659 return err;
1660 }
1661
1662 static const struct bpf_prog_ops * const bpf_prog_types[] = {
1663 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
1664 [_id] = & _name ## _prog_ops,
1665 #define BPF_MAP_TYPE(_id, _ops)
1666 #define BPF_LINK_TYPE(_id, _name)
1667 #include <linux/bpf_types.h>
1668 #undef BPF_PROG_TYPE
1669 #undef BPF_MAP_TYPE
1670 #undef BPF_LINK_TYPE
1671 };
1672
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)1673 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
1674 {
1675 const struct bpf_prog_ops *ops;
1676
1677 if (type >= ARRAY_SIZE(bpf_prog_types))
1678 return -EINVAL;
1679 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
1680 ops = bpf_prog_types[type];
1681 if (!ops)
1682 return -EINVAL;
1683
1684 if (!bpf_prog_is_dev_bound(prog->aux))
1685 prog->aux->ops = ops;
1686 else
1687 prog->aux->ops = &bpf_offload_prog_ops;
1688 prog->type = type;
1689 return 0;
1690 }
1691
1692 enum bpf_audit {
1693 BPF_AUDIT_LOAD,
1694 BPF_AUDIT_UNLOAD,
1695 BPF_AUDIT_MAX,
1696 };
1697
1698 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
1699 [BPF_AUDIT_LOAD] = "LOAD",
1700 [BPF_AUDIT_UNLOAD] = "UNLOAD",
1701 };
1702
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)1703 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
1704 {
1705 struct audit_context *ctx = NULL;
1706 struct audit_buffer *ab;
1707
1708 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
1709 return;
1710 if (audit_enabled == AUDIT_OFF)
1711 return;
1712 if (op == BPF_AUDIT_LOAD)
1713 ctx = audit_context();
1714 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
1715 if (unlikely(!ab))
1716 return;
1717 audit_log_format(ab, "prog-id=%u op=%s",
1718 prog->aux->id, bpf_audit_str[op]);
1719 audit_log_end(ab);
1720 }
1721
bpf_prog_alloc_id(struct bpf_prog * prog)1722 static int bpf_prog_alloc_id(struct bpf_prog *prog)
1723 {
1724 int id;
1725
1726 idr_preload(GFP_KERNEL);
1727 spin_lock_bh(&prog_idr_lock);
1728 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
1729 if (id > 0)
1730 prog->aux->id = id;
1731 spin_unlock_bh(&prog_idr_lock);
1732 idr_preload_end();
1733
1734 /* id is in [1, INT_MAX) */
1735 if (WARN_ON_ONCE(!id))
1736 return -ENOSPC;
1737
1738 return id > 0 ? 0 : id;
1739 }
1740
bpf_prog_free_id(struct bpf_prog * prog,bool do_idr_lock)1741 void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
1742 {
1743 unsigned long flags;
1744
1745 /* cBPF to eBPF migrations are currently not in the idr store.
1746 * Offloaded programs are removed from the store when their device
1747 * disappears - even if someone grabs an fd to them they are unusable,
1748 * simply waiting for refcnt to drop to be freed.
1749 */
1750 if (!prog->aux->id)
1751 return;
1752
1753 if (do_idr_lock)
1754 spin_lock_irqsave(&prog_idr_lock, flags);
1755 else
1756 __acquire(&prog_idr_lock);
1757
1758 idr_remove(&prog_idr, prog->aux->id);
1759 prog->aux->id = 0;
1760
1761 if (do_idr_lock)
1762 spin_unlock_irqrestore(&prog_idr_lock, flags);
1763 else
1764 __release(&prog_idr_lock);
1765 }
1766
__bpf_prog_put_rcu(struct rcu_head * rcu)1767 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
1768 {
1769 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
1770
1771 kvfree(aux->func_info);
1772 kfree(aux->func_info_aux);
1773 free_uid(aux->user);
1774 security_bpf_prog_free(aux);
1775 bpf_prog_free(aux->prog);
1776 }
1777
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)1778 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
1779 {
1780 bpf_prog_kallsyms_del_all(prog);
1781 btf_put(prog->aux->btf);
1782 kvfree(prog->aux->jited_linfo);
1783 kvfree(prog->aux->linfo);
1784 kfree(prog->aux->kfunc_tab);
1785 if (prog->aux->attach_btf)
1786 btf_put(prog->aux->attach_btf);
1787
1788 if (deferred) {
1789 if (prog->aux->sleepable)
1790 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
1791 else
1792 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
1793 } else {
1794 __bpf_prog_put_rcu(&prog->aux->rcu);
1795 }
1796 }
1797
bpf_prog_put_deferred(struct work_struct * work)1798 static void bpf_prog_put_deferred(struct work_struct *work)
1799 {
1800 struct bpf_prog_aux *aux;
1801 struct bpf_prog *prog;
1802
1803 aux = container_of(work, struct bpf_prog_aux, work);
1804 prog = aux->prog;
1805 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
1806 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
1807 __bpf_prog_put_noref(prog, true);
1808 }
1809
__bpf_prog_put(struct bpf_prog * prog,bool do_idr_lock)1810 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
1811 {
1812 struct bpf_prog_aux *aux = prog->aux;
1813
1814 if (atomic64_dec_and_test(&aux->refcnt)) {
1815 /* bpf_prog_free_id() must be called first */
1816 bpf_prog_free_id(prog, do_idr_lock);
1817
1818 if (in_irq() || irqs_disabled()) {
1819 INIT_WORK(&aux->work, bpf_prog_put_deferred);
1820 schedule_work(&aux->work);
1821 } else {
1822 bpf_prog_put_deferred(&aux->work);
1823 }
1824 }
1825 }
1826
bpf_prog_put(struct bpf_prog * prog)1827 void bpf_prog_put(struct bpf_prog *prog)
1828 {
1829 __bpf_prog_put(prog, true);
1830 }
1831 EXPORT_SYMBOL_GPL(bpf_prog_put);
1832
bpf_prog_release(struct inode * inode,struct file * filp)1833 static int bpf_prog_release(struct inode *inode, struct file *filp)
1834 {
1835 struct bpf_prog *prog = filp->private_data;
1836
1837 bpf_prog_put(prog);
1838 return 0;
1839 }
1840
1841 struct bpf_prog_kstats {
1842 u64 nsecs;
1843 u64 cnt;
1844 u64 misses;
1845 };
1846
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)1847 static void bpf_prog_get_stats(const struct bpf_prog *prog,
1848 struct bpf_prog_kstats *stats)
1849 {
1850 u64 nsecs = 0, cnt = 0, misses = 0;
1851 int cpu;
1852
1853 for_each_possible_cpu(cpu) {
1854 const struct bpf_prog_stats *st;
1855 unsigned int start;
1856 u64 tnsecs, tcnt, tmisses;
1857
1858 st = per_cpu_ptr(prog->stats, cpu);
1859 do {
1860 start = u64_stats_fetch_begin_irq(&st->syncp);
1861 tnsecs = u64_stats_read(&st->nsecs);
1862 tcnt = u64_stats_read(&st->cnt);
1863 tmisses = u64_stats_read(&st->misses);
1864 } while (u64_stats_fetch_retry_irq(&st->syncp, start));
1865 nsecs += tnsecs;
1866 cnt += tcnt;
1867 misses += tmisses;
1868 }
1869 stats->nsecs = nsecs;
1870 stats->cnt = cnt;
1871 stats->misses = misses;
1872 }
1873
1874 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)1875 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
1876 {
1877 const struct bpf_prog *prog = filp->private_data;
1878 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
1879 struct bpf_prog_kstats stats;
1880
1881 bpf_prog_get_stats(prog, &stats);
1882 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
1883 seq_printf(m,
1884 "prog_type:\t%u\n"
1885 "prog_jited:\t%u\n"
1886 "prog_tag:\t%s\n"
1887 "memlock:\t%llu\n"
1888 "prog_id:\t%u\n"
1889 "run_time_ns:\t%llu\n"
1890 "run_cnt:\t%llu\n"
1891 "recursion_misses:\t%llu\n"
1892 "verified_insns:\t%u\n",
1893 prog->type,
1894 prog->jited,
1895 prog_tag,
1896 prog->pages * 1ULL << PAGE_SHIFT,
1897 prog->aux->id,
1898 stats.nsecs,
1899 stats.cnt,
1900 stats.misses,
1901 prog->aux->verified_insns);
1902 }
1903 #endif
1904
1905 const struct file_operations bpf_prog_fops = {
1906 #ifdef CONFIG_PROC_FS
1907 .show_fdinfo = bpf_prog_show_fdinfo,
1908 #endif
1909 .release = bpf_prog_release,
1910 .read = bpf_dummy_read,
1911 .write = bpf_dummy_write,
1912 };
1913
bpf_prog_new_fd(struct bpf_prog * prog)1914 int bpf_prog_new_fd(struct bpf_prog *prog)
1915 {
1916 int ret;
1917
1918 ret = security_bpf_prog(prog);
1919 if (ret < 0)
1920 return ret;
1921
1922 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
1923 O_RDWR | O_CLOEXEC);
1924 }
1925
____bpf_prog_get(struct fd f)1926 static struct bpf_prog *____bpf_prog_get(struct fd f)
1927 {
1928 if (!f.file)
1929 return ERR_PTR(-EBADF);
1930 if (f.file->f_op != &bpf_prog_fops) {
1931 fdput(f);
1932 return ERR_PTR(-EINVAL);
1933 }
1934
1935 return f.file->private_data;
1936 }
1937
bpf_prog_add(struct bpf_prog * prog,int i)1938 void bpf_prog_add(struct bpf_prog *prog, int i)
1939 {
1940 atomic64_add(i, &prog->aux->refcnt);
1941 }
1942 EXPORT_SYMBOL_GPL(bpf_prog_add);
1943
bpf_prog_sub(struct bpf_prog * prog,int i)1944 void bpf_prog_sub(struct bpf_prog *prog, int i)
1945 {
1946 /* Only to be used for undoing previous bpf_prog_add() in some
1947 * error path. We still know that another entity in our call
1948 * path holds a reference to the program, thus atomic_sub() can
1949 * be safely used in such cases!
1950 */
1951 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
1952 }
1953 EXPORT_SYMBOL_GPL(bpf_prog_sub);
1954
bpf_prog_inc(struct bpf_prog * prog)1955 void bpf_prog_inc(struct bpf_prog *prog)
1956 {
1957 atomic64_inc(&prog->aux->refcnt);
1958 }
1959 EXPORT_SYMBOL_GPL(bpf_prog_inc);
1960
1961 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)1962 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
1963 {
1964 int refold;
1965
1966 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
1967
1968 if (!refold)
1969 return ERR_PTR(-ENOENT);
1970
1971 return prog;
1972 }
1973 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
1974
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)1975 bool bpf_prog_get_ok(struct bpf_prog *prog,
1976 enum bpf_prog_type *attach_type, bool attach_drv)
1977 {
1978 /* not an attachment, just a refcount inc, always allow */
1979 if (!attach_type)
1980 return true;
1981
1982 if (prog->type != *attach_type)
1983 return false;
1984 if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
1985 return false;
1986
1987 return true;
1988 }
1989
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)1990 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
1991 bool attach_drv)
1992 {
1993 struct fd f = fdget(ufd);
1994 struct bpf_prog *prog;
1995
1996 prog = ____bpf_prog_get(f);
1997 if (IS_ERR(prog))
1998 return prog;
1999 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
2000 prog = ERR_PTR(-EINVAL);
2001 goto out;
2002 }
2003
2004 bpf_prog_inc(prog);
2005 out:
2006 fdput(f);
2007 return prog;
2008 }
2009
bpf_prog_get(u32 ufd)2010 struct bpf_prog *bpf_prog_get(u32 ufd)
2011 {
2012 return __bpf_prog_get(ufd, NULL, false);
2013 }
2014
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2015 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2016 bool attach_drv)
2017 {
2018 return __bpf_prog_get(ufd, &type, attach_drv);
2019 }
2020 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2021
2022 /* Initially all BPF programs could be loaded w/o specifying
2023 * expected_attach_type. Later for some of them specifying expected_attach_type
2024 * at load time became required so that program could be validated properly.
2025 * Programs of types that are allowed to be loaded both w/ and w/o (for
2026 * backward compatibility) expected_attach_type, should have the default attach
2027 * type assigned to expected_attach_type for the latter case, so that it can be
2028 * validated later at attach time.
2029 *
2030 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2031 * prog type requires it but has some attach types that have to be backward
2032 * compatible.
2033 */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2034 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2035 {
2036 switch (attr->prog_type) {
2037 case BPF_PROG_TYPE_CGROUP_SOCK:
2038 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2039 * exist so checking for non-zero is the way to go here.
2040 */
2041 if (!attr->expected_attach_type)
2042 attr->expected_attach_type =
2043 BPF_CGROUP_INET_SOCK_CREATE;
2044 break;
2045 case BPF_PROG_TYPE_SK_REUSEPORT:
2046 if (!attr->expected_attach_type)
2047 attr->expected_attach_type =
2048 BPF_SK_REUSEPORT_SELECT;
2049 break;
2050 }
2051 }
2052
2053 static int
bpf_prog_load_check_attach(enum bpf_prog_type prog_type,enum bpf_attach_type expected_attach_type,struct btf * attach_btf,u32 btf_id,struct bpf_prog * dst_prog)2054 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2055 enum bpf_attach_type expected_attach_type,
2056 struct btf *attach_btf, u32 btf_id,
2057 struct bpf_prog *dst_prog)
2058 {
2059 if (btf_id) {
2060 if (btf_id > BTF_MAX_TYPE)
2061 return -EINVAL;
2062
2063 if (!attach_btf && !dst_prog)
2064 return -EINVAL;
2065
2066 switch (prog_type) {
2067 case BPF_PROG_TYPE_TRACING:
2068 case BPF_PROG_TYPE_LSM:
2069 case BPF_PROG_TYPE_STRUCT_OPS:
2070 case BPF_PROG_TYPE_EXT:
2071 break;
2072 default:
2073 return -EINVAL;
2074 }
2075 }
2076
2077 if (attach_btf && (!btf_id || dst_prog))
2078 return -EINVAL;
2079
2080 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2081 prog_type != BPF_PROG_TYPE_EXT)
2082 return -EINVAL;
2083
2084 switch (prog_type) {
2085 case BPF_PROG_TYPE_CGROUP_SOCK:
2086 switch (expected_attach_type) {
2087 case BPF_CGROUP_INET_SOCK_CREATE:
2088 case BPF_CGROUP_INET_SOCK_RELEASE:
2089 case BPF_CGROUP_INET4_POST_BIND:
2090 case BPF_CGROUP_INET6_POST_BIND:
2091 return 0;
2092 default:
2093 return -EINVAL;
2094 }
2095 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2096 switch (expected_attach_type) {
2097 case BPF_CGROUP_INET4_BIND:
2098 case BPF_CGROUP_INET6_BIND:
2099 case BPF_CGROUP_INET4_CONNECT:
2100 case BPF_CGROUP_INET6_CONNECT:
2101 case BPF_CGROUP_INET4_GETPEERNAME:
2102 case BPF_CGROUP_INET6_GETPEERNAME:
2103 case BPF_CGROUP_INET4_GETSOCKNAME:
2104 case BPF_CGROUP_INET6_GETSOCKNAME:
2105 case BPF_CGROUP_UDP4_SENDMSG:
2106 case BPF_CGROUP_UDP6_SENDMSG:
2107 case BPF_CGROUP_UDP4_RECVMSG:
2108 case BPF_CGROUP_UDP6_RECVMSG:
2109 return 0;
2110 default:
2111 return -EINVAL;
2112 }
2113 case BPF_PROG_TYPE_CGROUP_SKB:
2114 switch (expected_attach_type) {
2115 case BPF_CGROUP_INET_INGRESS:
2116 case BPF_CGROUP_INET_EGRESS:
2117 return 0;
2118 default:
2119 return -EINVAL;
2120 }
2121 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2122 switch (expected_attach_type) {
2123 case BPF_CGROUP_SETSOCKOPT:
2124 case BPF_CGROUP_GETSOCKOPT:
2125 return 0;
2126 default:
2127 return -EINVAL;
2128 }
2129 case BPF_PROG_TYPE_SK_LOOKUP:
2130 if (expected_attach_type == BPF_SK_LOOKUP)
2131 return 0;
2132 return -EINVAL;
2133 case BPF_PROG_TYPE_SK_REUSEPORT:
2134 switch (expected_attach_type) {
2135 case BPF_SK_REUSEPORT_SELECT:
2136 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2137 return 0;
2138 default:
2139 return -EINVAL;
2140 }
2141 case BPF_PROG_TYPE_SYSCALL:
2142 case BPF_PROG_TYPE_EXT:
2143 if (expected_attach_type)
2144 return -EINVAL;
2145 fallthrough;
2146 default:
2147 return 0;
2148 }
2149 }
2150
is_net_admin_prog_type(enum bpf_prog_type prog_type)2151 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2152 {
2153 switch (prog_type) {
2154 case BPF_PROG_TYPE_SCHED_CLS:
2155 case BPF_PROG_TYPE_SCHED_ACT:
2156 case BPF_PROG_TYPE_XDP:
2157 case BPF_PROG_TYPE_LWT_IN:
2158 case BPF_PROG_TYPE_LWT_OUT:
2159 case BPF_PROG_TYPE_LWT_XMIT:
2160 case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2161 case BPF_PROG_TYPE_SK_SKB:
2162 case BPF_PROG_TYPE_SK_MSG:
2163 case BPF_PROG_TYPE_LIRC_MODE2:
2164 case BPF_PROG_TYPE_FLOW_DISSECTOR:
2165 case BPF_PROG_TYPE_CGROUP_DEVICE:
2166 case BPF_PROG_TYPE_CGROUP_SOCK:
2167 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2168 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2169 case BPF_PROG_TYPE_CGROUP_SYSCTL:
2170 case BPF_PROG_TYPE_SOCK_OPS:
2171 case BPF_PROG_TYPE_EXT: /* extends any prog */
2172 return true;
2173 case BPF_PROG_TYPE_CGROUP_SKB:
2174 /* always unpriv */
2175 case BPF_PROG_TYPE_SK_REUSEPORT:
2176 /* equivalent to SOCKET_FILTER. need CAP_BPF only */
2177 default:
2178 return false;
2179 }
2180 }
2181
is_perfmon_prog_type(enum bpf_prog_type prog_type)2182 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2183 {
2184 switch (prog_type) {
2185 case BPF_PROG_TYPE_KPROBE:
2186 case BPF_PROG_TYPE_TRACEPOINT:
2187 case BPF_PROG_TYPE_PERF_EVENT:
2188 case BPF_PROG_TYPE_RAW_TRACEPOINT:
2189 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2190 case BPF_PROG_TYPE_TRACING:
2191 case BPF_PROG_TYPE_LSM:
2192 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2193 case BPF_PROG_TYPE_EXT: /* extends any prog */
2194 return true;
2195 default:
2196 return false;
2197 }
2198 }
2199
2200 /* last field in 'union bpf_attr' used by this command */
2201 #define BPF_PROG_LOAD_LAST_FIELD fd_array
2202
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr)2203 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
2204 {
2205 enum bpf_prog_type type = attr->prog_type;
2206 struct bpf_prog *prog, *dst_prog = NULL;
2207 struct btf *attach_btf = NULL;
2208 int err;
2209 char license[128];
2210 bool is_gpl;
2211
2212 if (CHECK_ATTR(BPF_PROG_LOAD))
2213 return -EINVAL;
2214
2215 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2216 BPF_F_ANY_ALIGNMENT |
2217 BPF_F_TEST_STATE_FREQ |
2218 BPF_F_SLEEPABLE |
2219 BPF_F_TEST_RND_HI32))
2220 return -EINVAL;
2221
2222 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2223 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2224 !bpf_capable())
2225 return -EPERM;
2226
2227 /* copy eBPF program license from user space */
2228 if (strncpy_from_bpfptr(license,
2229 make_bpfptr(attr->license, uattr.is_kernel),
2230 sizeof(license) - 1) < 0)
2231 return -EFAULT;
2232 license[sizeof(license) - 1] = 0;
2233
2234 /* eBPF programs must be GPL compatible to use GPL-ed functions */
2235 is_gpl = license_is_gpl_compatible(license);
2236
2237 if (attr->insn_cnt == 0 ||
2238 attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
2239 return -E2BIG;
2240 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2241 type != BPF_PROG_TYPE_CGROUP_SKB &&
2242 !bpf_capable())
2243 return -EPERM;
2244
2245 if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
2246 return -EPERM;
2247 if (is_perfmon_prog_type(type) && !perfmon_capable())
2248 return -EPERM;
2249
2250 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2251 * or btf, we need to check which one it is
2252 */
2253 if (attr->attach_prog_fd) {
2254 dst_prog = bpf_prog_get(attr->attach_prog_fd);
2255 if (IS_ERR(dst_prog)) {
2256 dst_prog = NULL;
2257 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2258 if (IS_ERR(attach_btf))
2259 return -EINVAL;
2260 if (!btf_is_kernel(attach_btf)) {
2261 /* attaching through specifying bpf_prog's BTF
2262 * objects directly might be supported eventually
2263 */
2264 btf_put(attach_btf);
2265 return -ENOTSUPP;
2266 }
2267 }
2268 } else if (attr->attach_btf_id) {
2269 /* fall back to vmlinux BTF, if BTF type ID is specified */
2270 attach_btf = bpf_get_btf_vmlinux();
2271 if (IS_ERR(attach_btf))
2272 return PTR_ERR(attach_btf);
2273 if (!attach_btf)
2274 return -EINVAL;
2275 btf_get(attach_btf);
2276 }
2277
2278 bpf_prog_load_fixup_attach_type(attr);
2279 if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2280 attach_btf, attr->attach_btf_id,
2281 dst_prog)) {
2282 if (dst_prog)
2283 bpf_prog_put(dst_prog);
2284 if (attach_btf)
2285 btf_put(attach_btf);
2286 return -EINVAL;
2287 }
2288
2289 /* plain bpf_prog allocation */
2290 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2291 if (!prog) {
2292 if (dst_prog)
2293 bpf_prog_put(dst_prog);
2294 if (attach_btf)
2295 btf_put(attach_btf);
2296 return -ENOMEM;
2297 }
2298
2299 prog->expected_attach_type = attr->expected_attach_type;
2300 prog->aux->attach_btf = attach_btf;
2301 prog->aux->attach_btf_id = attr->attach_btf_id;
2302 prog->aux->dst_prog = dst_prog;
2303 prog->aux->offload_requested = !!attr->prog_ifindex;
2304 prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
2305
2306 err = security_bpf_prog_alloc(prog->aux);
2307 if (err)
2308 goto free_prog;
2309
2310 prog->aux->user = get_current_user();
2311 prog->len = attr->insn_cnt;
2312
2313 err = -EFAULT;
2314 if (copy_from_bpfptr(prog->insns,
2315 make_bpfptr(attr->insns, uattr.is_kernel),
2316 bpf_prog_insn_size(prog)) != 0)
2317 goto free_prog_sec;
2318
2319 prog->orig_prog = NULL;
2320 prog->jited = 0;
2321
2322 atomic64_set(&prog->aux->refcnt, 1);
2323 prog->gpl_compatible = is_gpl ? 1 : 0;
2324
2325 if (bpf_prog_is_dev_bound(prog->aux)) {
2326 err = bpf_prog_offload_init(prog, attr);
2327 if (err)
2328 goto free_prog_sec;
2329 }
2330
2331 /* find program type: socket_filter vs tracing_filter */
2332 err = find_prog_type(type, prog);
2333 if (err < 0)
2334 goto free_prog_sec;
2335
2336 prog->aux->load_time = ktime_get_boottime_ns();
2337 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2338 sizeof(attr->prog_name));
2339 if (err < 0)
2340 goto free_prog_sec;
2341
2342 /* run eBPF verifier */
2343 err = bpf_check(&prog, attr, uattr);
2344 if (err < 0)
2345 goto free_used_maps;
2346
2347 prog = bpf_prog_select_runtime(prog, &err);
2348 if (err < 0)
2349 goto free_used_maps;
2350
2351 err = bpf_prog_alloc_id(prog);
2352 if (err)
2353 goto free_used_maps;
2354
2355 /* Upon success of bpf_prog_alloc_id(), the BPF prog is
2356 * effectively publicly exposed. However, retrieving via
2357 * bpf_prog_get_fd_by_id() will take another reference,
2358 * therefore it cannot be gone underneath us.
2359 *
2360 * Only for the time /after/ successful bpf_prog_new_fd()
2361 * and before returning to userspace, we might just hold
2362 * one reference and any parallel close on that fd could
2363 * rip everything out. Hence, below notifications must
2364 * happen before bpf_prog_new_fd().
2365 *
2366 * Also, any failure handling from this point onwards must
2367 * be using bpf_prog_put() given the program is exposed.
2368 */
2369 bpf_prog_kallsyms_add(prog);
2370 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2371 bpf_audit_prog(prog, BPF_AUDIT_LOAD);
2372
2373 err = bpf_prog_new_fd(prog);
2374 if (err < 0)
2375 bpf_prog_put(prog);
2376 return err;
2377
2378 free_used_maps:
2379 /* In case we have subprogs, we need to wait for a grace
2380 * period before we can tear down JIT memory since symbols
2381 * are already exposed under kallsyms.
2382 */
2383 __bpf_prog_put_noref(prog, prog->aux->func_cnt);
2384 return err;
2385 free_prog_sec:
2386 free_uid(prog->aux->user);
2387 security_bpf_prog_free(prog->aux);
2388 free_prog:
2389 if (prog->aux->attach_btf)
2390 btf_put(prog->aux->attach_btf);
2391 bpf_prog_free(prog);
2392 return err;
2393 }
2394
2395 #define BPF_OBJ_LAST_FIELD file_flags
2396
bpf_obj_pin(const union bpf_attr * attr)2397 static int bpf_obj_pin(const union bpf_attr *attr)
2398 {
2399 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
2400 return -EINVAL;
2401
2402 return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
2403 }
2404
bpf_obj_get(const union bpf_attr * attr)2405 static int bpf_obj_get(const union bpf_attr *attr)
2406 {
2407 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
2408 attr->file_flags & ~BPF_OBJ_FLAG_MASK)
2409 return -EINVAL;
2410
2411 return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
2412 attr->file_flags);
2413 }
2414
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)2415 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
2416 const struct bpf_link_ops *ops, struct bpf_prog *prog)
2417 {
2418 atomic64_set(&link->refcnt, 1);
2419 link->type = type;
2420 link->id = 0;
2421 link->ops = ops;
2422 link->prog = prog;
2423 }
2424
bpf_link_free_id(int id)2425 static void bpf_link_free_id(int id)
2426 {
2427 if (!id)
2428 return;
2429
2430 spin_lock_bh(&link_idr_lock);
2431 idr_remove(&link_idr, id);
2432 spin_unlock_bh(&link_idr_lock);
2433 }
2434
2435 /* Clean up bpf_link and corresponding anon_inode file and FD. After
2436 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
2437 * anon_inode's release() call. This helper marksbpf_link as
2438 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
2439 * is not decremented, it's the responsibility of a calling code that failed
2440 * to complete bpf_link initialization.
2441 */
bpf_link_cleanup(struct bpf_link_primer * primer)2442 void bpf_link_cleanup(struct bpf_link_primer *primer)
2443 {
2444 primer->link->prog = NULL;
2445 bpf_link_free_id(primer->id);
2446 fput(primer->file);
2447 put_unused_fd(primer->fd);
2448 }
2449
bpf_link_inc(struct bpf_link * link)2450 void bpf_link_inc(struct bpf_link *link)
2451 {
2452 atomic64_inc(&link->refcnt);
2453 }
2454
2455 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)2456 static void bpf_link_free(struct bpf_link *link)
2457 {
2458 bpf_link_free_id(link->id);
2459 if (link->prog) {
2460 /* detach BPF program, clean up used resources */
2461 link->ops->release(link);
2462 bpf_prog_put(link->prog);
2463 }
2464 /* free bpf_link and its containing memory */
2465 link->ops->dealloc(link);
2466 }
2467
bpf_link_put_deferred(struct work_struct * work)2468 static void bpf_link_put_deferred(struct work_struct *work)
2469 {
2470 struct bpf_link *link = container_of(work, struct bpf_link, work);
2471
2472 bpf_link_free(link);
2473 }
2474
2475 /* bpf_link_put can be called from atomic context, but ensures that resources
2476 * are freed from process context
2477 */
bpf_link_put(struct bpf_link * link)2478 void bpf_link_put(struct bpf_link *link)
2479 {
2480 if (!atomic64_dec_and_test(&link->refcnt))
2481 return;
2482
2483 if (in_atomic()) {
2484 INIT_WORK(&link->work, bpf_link_put_deferred);
2485 schedule_work(&link->work);
2486 } else {
2487 bpf_link_free(link);
2488 }
2489 }
2490
bpf_link_release(struct inode * inode,struct file * filp)2491 static int bpf_link_release(struct inode *inode, struct file *filp)
2492 {
2493 struct bpf_link *link = filp->private_data;
2494
2495 bpf_link_put(link);
2496 return 0;
2497 }
2498
2499 #ifdef CONFIG_PROC_FS
2500 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
2501 #define BPF_MAP_TYPE(_id, _ops)
2502 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
2503 static const char *bpf_link_type_strs[] = {
2504 [BPF_LINK_TYPE_UNSPEC] = "<invalid>",
2505 #include <linux/bpf_types.h>
2506 };
2507 #undef BPF_PROG_TYPE
2508 #undef BPF_MAP_TYPE
2509 #undef BPF_LINK_TYPE
2510
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)2511 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
2512 {
2513 const struct bpf_link *link = filp->private_data;
2514 const struct bpf_prog *prog = link->prog;
2515 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2516
2517 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2518 seq_printf(m,
2519 "link_type:\t%s\n"
2520 "link_id:\t%u\n"
2521 "prog_tag:\t%s\n"
2522 "prog_id:\t%u\n",
2523 bpf_link_type_strs[link->type],
2524 link->id,
2525 prog_tag,
2526 prog->aux->id);
2527 if (link->ops->show_fdinfo)
2528 link->ops->show_fdinfo(link, m);
2529 }
2530 #endif
2531
2532 static const struct file_operations bpf_link_fops = {
2533 #ifdef CONFIG_PROC_FS
2534 .show_fdinfo = bpf_link_show_fdinfo,
2535 #endif
2536 .release = bpf_link_release,
2537 .read = bpf_dummy_read,
2538 .write = bpf_dummy_write,
2539 };
2540
bpf_link_alloc_id(struct bpf_link * link)2541 static int bpf_link_alloc_id(struct bpf_link *link)
2542 {
2543 int id;
2544
2545 idr_preload(GFP_KERNEL);
2546 spin_lock_bh(&link_idr_lock);
2547 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
2548 spin_unlock_bh(&link_idr_lock);
2549 idr_preload_end();
2550
2551 return id;
2552 }
2553
2554 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
2555 * reserving unused FD and allocating ID from link_idr. This is to be paired
2556 * with bpf_link_settle() to install FD and ID and expose bpf_link to
2557 * user-space, if bpf_link is successfully attached. If not, bpf_link and
2558 * pre-allocated resources are to be freed with bpf_cleanup() call. All the
2559 * transient state is passed around in struct bpf_link_primer.
2560 * This is preferred way to create and initialize bpf_link, especially when
2561 * there are complicated and expensive operations inbetween creating bpf_link
2562 * itself and attaching it to BPF hook. By using bpf_link_prime() and
2563 * bpf_link_settle() kernel code using bpf_link doesn't have to perform
2564 * expensive (and potentially failing) roll back operations in a rare case
2565 * that file, FD, or ID can't be allocated.
2566 */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)2567 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
2568 {
2569 struct file *file;
2570 int fd, id;
2571
2572 fd = get_unused_fd_flags(O_CLOEXEC);
2573 if (fd < 0)
2574 return fd;
2575
2576
2577 id = bpf_link_alloc_id(link);
2578 if (id < 0) {
2579 put_unused_fd(fd);
2580 return id;
2581 }
2582
2583 file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
2584 if (IS_ERR(file)) {
2585 bpf_link_free_id(id);
2586 put_unused_fd(fd);
2587 return PTR_ERR(file);
2588 }
2589
2590 primer->link = link;
2591 primer->file = file;
2592 primer->fd = fd;
2593 primer->id = id;
2594 return 0;
2595 }
2596
bpf_link_settle(struct bpf_link_primer * primer)2597 int bpf_link_settle(struct bpf_link_primer *primer)
2598 {
2599 /* make bpf_link fetchable by ID */
2600 spin_lock_bh(&link_idr_lock);
2601 primer->link->id = primer->id;
2602 spin_unlock_bh(&link_idr_lock);
2603 /* make bpf_link fetchable by FD */
2604 fd_install(primer->fd, primer->file);
2605 /* pass through installed FD */
2606 return primer->fd;
2607 }
2608
bpf_link_new_fd(struct bpf_link * link)2609 int bpf_link_new_fd(struct bpf_link *link)
2610 {
2611 return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
2612 }
2613
bpf_link_get_from_fd(u32 ufd)2614 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
2615 {
2616 struct fd f = fdget(ufd);
2617 struct bpf_link *link;
2618
2619 if (!f.file)
2620 return ERR_PTR(-EBADF);
2621 if (f.file->f_op != &bpf_link_fops) {
2622 fdput(f);
2623 return ERR_PTR(-EINVAL);
2624 }
2625
2626 link = f.file->private_data;
2627 bpf_link_inc(link);
2628 fdput(f);
2629
2630 return link;
2631 }
2632
2633 struct bpf_tracing_link {
2634 struct bpf_link link;
2635 enum bpf_attach_type attach_type;
2636 struct bpf_trampoline *trampoline;
2637 struct bpf_prog *tgt_prog;
2638 };
2639
bpf_tracing_link_release(struct bpf_link * link)2640 static void bpf_tracing_link_release(struct bpf_link *link)
2641 {
2642 struct bpf_tracing_link *tr_link =
2643 container_of(link, struct bpf_tracing_link, link);
2644
2645 WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->prog,
2646 tr_link->trampoline));
2647
2648 bpf_trampoline_put(tr_link->trampoline);
2649
2650 /* tgt_prog is NULL if target is a kernel function */
2651 if (tr_link->tgt_prog)
2652 bpf_prog_put(tr_link->tgt_prog);
2653 }
2654
bpf_tracing_link_dealloc(struct bpf_link * link)2655 static void bpf_tracing_link_dealloc(struct bpf_link *link)
2656 {
2657 struct bpf_tracing_link *tr_link =
2658 container_of(link, struct bpf_tracing_link, link);
2659
2660 kfree(tr_link);
2661 }
2662
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)2663 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
2664 struct seq_file *seq)
2665 {
2666 struct bpf_tracing_link *tr_link =
2667 container_of(link, struct bpf_tracing_link, link);
2668
2669 seq_printf(seq,
2670 "attach_type:\t%d\n",
2671 tr_link->attach_type);
2672 }
2673
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2674 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
2675 struct bpf_link_info *info)
2676 {
2677 struct bpf_tracing_link *tr_link =
2678 container_of(link, struct bpf_tracing_link, link);
2679
2680 info->tracing.attach_type = tr_link->attach_type;
2681 bpf_trampoline_unpack_key(tr_link->trampoline->key,
2682 &info->tracing.target_obj_id,
2683 &info->tracing.target_btf_id);
2684
2685 return 0;
2686 }
2687
2688 static const struct bpf_link_ops bpf_tracing_link_lops = {
2689 .release = bpf_tracing_link_release,
2690 .dealloc = bpf_tracing_link_dealloc,
2691 .show_fdinfo = bpf_tracing_link_show_fdinfo,
2692 .fill_link_info = bpf_tracing_link_fill_link_info,
2693 };
2694
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id)2695 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
2696 int tgt_prog_fd,
2697 u32 btf_id)
2698 {
2699 struct bpf_link_primer link_primer;
2700 struct bpf_prog *tgt_prog = NULL;
2701 struct bpf_trampoline *tr = NULL;
2702 struct bpf_tracing_link *link;
2703 u64 key = 0;
2704 int err;
2705
2706 switch (prog->type) {
2707 case BPF_PROG_TYPE_TRACING:
2708 if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
2709 prog->expected_attach_type != BPF_TRACE_FEXIT &&
2710 prog->expected_attach_type != BPF_MODIFY_RETURN) {
2711 err = -EINVAL;
2712 goto out_put_prog;
2713 }
2714 break;
2715 case BPF_PROG_TYPE_EXT:
2716 if (prog->expected_attach_type != 0) {
2717 err = -EINVAL;
2718 goto out_put_prog;
2719 }
2720 break;
2721 case BPF_PROG_TYPE_LSM:
2722 if (prog->expected_attach_type != BPF_LSM_MAC) {
2723 err = -EINVAL;
2724 goto out_put_prog;
2725 }
2726 break;
2727 default:
2728 err = -EINVAL;
2729 goto out_put_prog;
2730 }
2731
2732 if (!!tgt_prog_fd != !!btf_id) {
2733 err = -EINVAL;
2734 goto out_put_prog;
2735 }
2736
2737 if (tgt_prog_fd) {
2738 /* For now we only allow new targets for BPF_PROG_TYPE_EXT */
2739 if (prog->type != BPF_PROG_TYPE_EXT) {
2740 err = -EINVAL;
2741 goto out_put_prog;
2742 }
2743
2744 tgt_prog = bpf_prog_get(tgt_prog_fd);
2745 if (IS_ERR(tgt_prog)) {
2746 err = PTR_ERR(tgt_prog);
2747 tgt_prog = NULL;
2748 goto out_put_prog;
2749 }
2750
2751 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
2752 }
2753
2754 link = kzalloc(sizeof(*link), GFP_USER);
2755 if (!link) {
2756 err = -ENOMEM;
2757 goto out_put_prog;
2758 }
2759 bpf_link_init(&link->link, BPF_LINK_TYPE_TRACING,
2760 &bpf_tracing_link_lops, prog);
2761 link->attach_type = prog->expected_attach_type;
2762
2763 mutex_lock(&prog->aux->dst_mutex);
2764
2765 /* There are a few possible cases here:
2766 *
2767 * - if prog->aux->dst_trampoline is set, the program was just loaded
2768 * and not yet attached to anything, so we can use the values stored
2769 * in prog->aux
2770 *
2771 * - if prog->aux->dst_trampoline is NULL, the program has already been
2772 * attached to a target and its initial target was cleared (below)
2773 *
2774 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
2775 * target_btf_id using the link_create API.
2776 *
2777 * - if tgt_prog == NULL when this function was called using the old
2778 * raw_tracepoint_open API, and we need a target from prog->aux
2779 *
2780 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
2781 * was detached and is going for re-attachment.
2782 */
2783 if (!prog->aux->dst_trampoline && !tgt_prog) {
2784 /*
2785 * Allow re-attach for TRACING and LSM programs. If it's
2786 * currently linked, bpf_trampoline_link_prog will fail.
2787 * EXT programs need to specify tgt_prog_fd, so they
2788 * re-attach in separate code path.
2789 */
2790 if (prog->type != BPF_PROG_TYPE_TRACING &&
2791 prog->type != BPF_PROG_TYPE_LSM) {
2792 err = -EINVAL;
2793 goto out_unlock;
2794 }
2795 btf_id = prog->aux->attach_btf_id;
2796 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
2797 }
2798
2799 if (!prog->aux->dst_trampoline ||
2800 (key && key != prog->aux->dst_trampoline->key)) {
2801 /* If there is no saved target, or the specified target is
2802 * different from the destination specified at load time, we
2803 * need a new trampoline and a check for compatibility
2804 */
2805 struct bpf_attach_target_info tgt_info = {};
2806
2807 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
2808 &tgt_info);
2809 if (err)
2810 goto out_unlock;
2811
2812 tr = bpf_trampoline_get(key, &tgt_info);
2813 if (!tr) {
2814 err = -ENOMEM;
2815 goto out_unlock;
2816 }
2817 } else {
2818 /* The caller didn't specify a target, or the target was the
2819 * same as the destination supplied during program load. This
2820 * means we can reuse the trampoline and reference from program
2821 * load time, and there is no need to allocate a new one. This
2822 * can only happen once for any program, as the saved values in
2823 * prog->aux are cleared below.
2824 */
2825 tr = prog->aux->dst_trampoline;
2826 tgt_prog = prog->aux->dst_prog;
2827 }
2828
2829 err = bpf_link_prime(&link->link, &link_primer);
2830 if (err)
2831 goto out_unlock;
2832
2833 err = bpf_trampoline_link_prog(prog, tr);
2834 if (err) {
2835 bpf_link_cleanup(&link_primer);
2836 link = NULL;
2837 goto out_unlock;
2838 }
2839
2840 link->tgt_prog = tgt_prog;
2841 link->trampoline = tr;
2842
2843 /* Always clear the trampoline and target prog from prog->aux to make
2844 * sure the original attach destination is not kept alive after a
2845 * program is (re-)attached to another target.
2846 */
2847 if (prog->aux->dst_prog &&
2848 (tgt_prog_fd || tr != prog->aux->dst_trampoline))
2849 /* got extra prog ref from syscall, or attaching to different prog */
2850 bpf_prog_put(prog->aux->dst_prog);
2851 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
2852 /* we allocated a new trampoline, so free the old one */
2853 bpf_trampoline_put(prog->aux->dst_trampoline);
2854
2855 prog->aux->dst_prog = NULL;
2856 prog->aux->dst_trampoline = NULL;
2857 mutex_unlock(&prog->aux->dst_mutex);
2858
2859 return bpf_link_settle(&link_primer);
2860 out_unlock:
2861 if (tr && tr != prog->aux->dst_trampoline)
2862 bpf_trampoline_put(tr);
2863 mutex_unlock(&prog->aux->dst_mutex);
2864 kfree(link);
2865 out_put_prog:
2866 if (tgt_prog_fd && tgt_prog)
2867 bpf_prog_put(tgt_prog);
2868 return err;
2869 }
2870
2871 struct bpf_raw_tp_link {
2872 struct bpf_link link;
2873 struct bpf_raw_event_map *btp;
2874 };
2875
bpf_raw_tp_link_release(struct bpf_link * link)2876 static void bpf_raw_tp_link_release(struct bpf_link *link)
2877 {
2878 struct bpf_raw_tp_link *raw_tp =
2879 container_of(link, struct bpf_raw_tp_link, link);
2880
2881 bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
2882 bpf_put_raw_tracepoint(raw_tp->btp);
2883 }
2884
bpf_raw_tp_link_dealloc(struct bpf_link * link)2885 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
2886 {
2887 struct bpf_raw_tp_link *raw_tp =
2888 container_of(link, struct bpf_raw_tp_link, link);
2889
2890 kfree(raw_tp);
2891 }
2892
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)2893 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
2894 struct seq_file *seq)
2895 {
2896 struct bpf_raw_tp_link *raw_tp_link =
2897 container_of(link, struct bpf_raw_tp_link, link);
2898
2899 seq_printf(seq,
2900 "tp_name:\t%s\n",
2901 raw_tp_link->btp->tp->name);
2902 }
2903
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2904 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
2905 struct bpf_link_info *info)
2906 {
2907 struct bpf_raw_tp_link *raw_tp_link =
2908 container_of(link, struct bpf_raw_tp_link, link);
2909 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
2910 const char *tp_name = raw_tp_link->btp->tp->name;
2911 u32 ulen = info->raw_tracepoint.tp_name_len;
2912 size_t tp_len = strlen(tp_name);
2913
2914 if (!ulen ^ !ubuf)
2915 return -EINVAL;
2916
2917 info->raw_tracepoint.tp_name_len = tp_len + 1;
2918
2919 if (!ubuf)
2920 return 0;
2921
2922 if (ulen >= tp_len + 1) {
2923 if (copy_to_user(ubuf, tp_name, tp_len + 1))
2924 return -EFAULT;
2925 } else {
2926 char zero = '\0';
2927
2928 if (copy_to_user(ubuf, tp_name, ulen - 1))
2929 return -EFAULT;
2930 if (put_user(zero, ubuf + ulen - 1))
2931 return -EFAULT;
2932 return -ENOSPC;
2933 }
2934
2935 return 0;
2936 }
2937
2938 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
2939 .release = bpf_raw_tp_link_release,
2940 .dealloc = bpf_raw_tp_link_dealloc,
2941 .show_fdinfo = bpf_raw_tp_link_show_fdinfo,
2942 .fill_link_info = bpf_raw_tp_link_fill_link_info,
2943 };
2944
2945 #ifdef CONFIG_PERF_EVENTS
2946 struct bpf_perf_link {
2947 struct bpf_link link;
2948 struct file *perf_file;
2949 };
2950
bpf_perf_link_release(struct bpf_link * link)2951 static void bpf_perf_link_release(struct bpf_link *link)
2952 {
2953 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
2954 struct perf_event *event = perf_link->perf_file->private_data;
2955
2956 perf_event_free_bpf_prog(event);
2957 fput(perf_link->perf_file);
2958 }
2959
bpf_perf_link_dealloc(struct bpf_link * link)2960 static void bpf_perf_link_dealloc(struct bpf_link *link)
2961 {
2962 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
2963
2964 kfree(perf_link);
2965 }
2966
2967 static const struct bpf_link_ops bpf_perf_link_lops = {
2968 .release = bpf_perf_link_release,
2969 .dealloc = bpf_perf_link_dealloc,
2970 };
2971
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2972 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2973 {
2974 struct bpf_link_primer link_primer;
2975 struct bpf_perf_link *link;
2976 struct perf_event *event;
2977 struct file *perf_file;
2978 int err;
2979
2980 if (attr->link_create.flags)
2981 return -EINVAL;
2982
2983 perf_file = perf_event_get(attr->link_create.target_fd);
2984 if (IS_ERR(perf_file))
2985 return PTR_ERR(perf_file);
2986
2987 link = kzalloc(sizeof(*link), GFP_USER);
2988 if (!link) {
2989 err = -ENOMEM;
2990 goto out_put_file;
2991 }
2992 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
2993 link->perf_file = perf_file;
2994
2995 err = bpf_link_prime(&link->link, &link_primer);
2996 if (err) {
2997 kfree(link);
2998 goto out_put_file;
2999 }
3000
3001 event = perf_file->private_data;
3002 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3003 if (err) {
3004 bpf_link_cleanup(&link_primer);
3005 goto out_put_file;
3006 }
3007 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3008 bpf_prog_inc(prog);
3009
3010 return bpf_link_settle(&link_primer);
3011
3012 out_put_file:
3013 fput(perf_file);
3014 return err;
3015 }
3016 #endif /* CONFIG_PERF_EVENTS */
3017
3018 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
3019
bpf_raw_tracepoint_open(const union bpf_attr * attr)3020 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
3021 {
3022 struct bpf_link_primer link_primer;
3023 struct bpf_raw_tp_link *link;
3024 struct bpf_raw_event_map *btp;
3025 struct bpf_prog *prog;
3026 const char *tp_name;
3027 char buf[128];
3028 int err;
3029
3030 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
3031 return -EINVAL;
3032
3033 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
3034 if (IS_ERR(prog))
3035 return PTR_ERR(prog);
3036
3037 switch (prog->type) {
3038 case BPF_PROG_TYPE_TRACING:
3039 case BPF_PROG_TYPE_EXT:
3040 case BPF_PROG_TYPE_LSM:
3041 if (attr->raw_tracepoint.name) {
3042 /* The attach point for this category of programs
3043 * should be specified via btf_id during program load.
3044 */
3045 err = -EINVAL;
3046 goto out_put_prog;
3047 }
3048 if (prog->type == BPF_PROG_TYPE_TRACING &&
3049 prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3050 tp_name = prog->aux->attach_func_name;
3051 break;
3052 }
3053 err = bpf_tracing_prog_attach(prog, 0, 0);
3054 if (err >= 0)
3055 return err;
3056 goto out_put_prog;
3057 case BPF_PROG_TYPE_RAW_TRACEPOINT:
3058 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3059 if (strncpy_from_user(buf,
3060 u64_to_user_ptr(attr->raw_tracepoint.name),
3061 sizeof(buf) - 1) < 0) {
3062 err = -EFAULT;
3063 goto out_put_prog;
3064 }
3065 buf[sizeof(buf) - 1] = 0;
3066 tp_name = buf;
3067 break;
3068 default:
3069 err = -EINVAL;
3070 goto out_put_prog;
3071 }
3072
3073 btp = bpf_get_raw_tracepoint(tp_name);
3074 if (!btp) {
3075 err = -ENOENT;
3076 goto out_put_prog;
3077 }
3078
3079 link = kzalloc(sizeof(*link), GFP_USER);
3080 if (!link) {
3081 err = -ENOMEM;
3082 goto out_put_btp;
3083 }
3084 bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3085 &bpf_raw_tp_link_lops, prog);
3086 link->btp = btp;
3087
3088 err = bpf_link_prime(&link->link, &link_primer);
3089 if (err) {
3090 kfree(link);
3091 goto out_put_btp;
3092 }
3093
3094 err = bpf_probe_register(link->btp, prog);
3095 if (err) {
3096 bpf_link_cleanup(&link_primer);
3097 goto out_put_btp;
3098 }
3099
3100 return bpf_link_settle(&link_primer);
3101
3102 out_put_btp:
3103 bpf_put_raw_tracepoint(btp);
3104 out_put_prog:
3105 bpf_prog_put(prog);
3106 return err;
3107 }
3108
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)3109 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
3110 enum bpf_attach_type attach_type)
3111 {
3112 switch (prog->type) {
3113 case BPF_PROG_TYPE_CGROUP_SOCK:
3114 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3115 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3116 case BPF_PROG_TYPE_SK_LOOKUP:
3117 return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
3118 case BPF_PROG_TYPE_CGROUP_SKB:
3119 if (!capable(CAP_NET_ADMIN))
3120 /* cg-skb progs can be loaded by unpriv user.
3121 * check permissions at attach time.
3122 */
3123 return -EPERM;
3124 return prog->enforce_expected_attach_type &&
3125 prog->expected_attach_type != attach_type ?
3126 -EINVAL : 0;
3127 default:
3128 return 0;
3129 }
3130 }
3131
3132 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)3133 attach_type_to_prog_type(enum bpf_attach_type attach_type)
3134 {
3135 switch (attach_type) {
3136 case BPF_CGROUP_INET_INGRESS:
3137 case BPF_CGROUP_INET_EGRESS:
3138 return BPF_PROG_TYPE_CGROUP_SKB;
3139 case BPF_CGROUP_INET_SOCK_CREATE:
3140 case BPF_CGROUP_INET_SOCK_RELEASE:
3141 case BPF_CGROUP_INET4_POST_BIND:
3142 case BPF_CGROUP_INET6_POST_BIND:
3143 return BPF_PROG_TYPE_CGROUP_SOCK;
3144 case BPF_CGROUP_INET4_BIND:
3145 case BPF_CGROUP_INET6_BIND:
3146 case BPF_CGROUP_INET4_CONNECT:
3147 case BPF_CGROUP_INET6_CONNECT:
3148 case BPF_CGROUP_INET4_GETPEERNAME:
3149 case BPF_CGROUP_INET6_GETPEERNAME:
3150 case BPF_CGROUP_INET4_GETSOCKNAME:
3151 case BPF_CGROUP_INET6_GETSOCKNAME:
3152 case BPF_CGROUP_UDP4_SENDMSG:
3153 case BPF_CGROUP_UDP6_SENDMSG:
3154 case BPF_CGROUP_UDP4_RECVMSG:
3155 case BPF_CGROUP_UDP6_RECVMSG:
3156 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
3157 case BPF_CGROUP_SOCK_OPS:
3158 return BPF_PROG_TYPE_SOCK_OPS;
3159 case BPF_CGROUP_DEVICE:
3160 return BPF_PROG_TYPE_CGROUP_DEVICE;
3161 case BPF_SK_MSG_VERDICT:
3162 return BPF_PROG_TYPE_SK_MSG;
3163 case BPF_SK_SKB_STREAM_PARSER:
3164 case BPF_SK_SKB_STREAM_VERDICT:
3165 case BPF_SK_SKB_VERDICT:
3166 return BPF_PROG_TYPE_SK_SKB;
3167 case BPF_LIRC_MODE2:
3168 return BPF_PROG_TYPE_LIRC_MODE2;
3169 case BPF_FLOW_DISSECTOR:
3170 return BPF_PROG_TYPE_FLOW_DISSECTOR;
3171 case BPF_CGROUP_SYSCTL:
3172 return BPF_PROG_TYPE_CGROUP_SYSCTL;
3173 case BPF_CGROUP_GETSOCKOPT:
3174 case BPF_CGROUP_SETSOCKOPT:
3175 return BPF_PROG_TYPE_CGROUP_SOCKOPT;
3176 case BPF_TRACE_ITER:
3177 return BPF_PROG_TYPE_TRACING;
3178 case BPF_SK_LOOKUP:
3179 return BPF_PROG_TYPE_SK_LOOKUP;
3180 case BPF_XDP:
3181 return BPF_PROG_TYPE_XDP;
3182 default:
3183 return BPF_PROG_TYPE_UNSPEC;
3184 }
3185 }
3186
3187 #define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd
3188
3189 #define BPF_F_ATTACH_MASK \
3190 (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)
3191
bpf_prog_attach(const union bpf_attr * attr)3192 static int bpf_prog_attach(const union bpf_attr *attr)
3193 {
3194 enum bpf_prog_type ptype;
3195 struct bpf_prog *prog;
3196 int ret;
3197
3198 if (CHECK_ATTR(BPF_PROG_ATTACH))
3199 return -EINVAL;
3200
3201 if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
3202 return -EINVAL;
3203
3204 ptype = attach_type_to_prog_type(attr->attach_type);
3205 if (ptype == BPF_PROG_TYPE_UNSPEC)
3206 return -EINVAL;
3207
3208 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
3209 if (IS_ERR(prog))
3210 return PTR_ERR(prog);
3211
3212 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
3213 bpf_prog_put(prog);
3214 return -EINVAL;
3215 }
3216
3217 switch (ptype) {
3218 case BPF_PROG_TYPE_SK_SKB:
3219 case BPF_PROG_TYPE_SK_MSG:
3220 ret = sock_map_get_from_fd(attr, prog);
3221 break;
3222 case BPF_PROG_TYPE_LIRC_MODE2:
3223 ret = lirc_prog_attach(attr, prog);
3224 break;
3225 case BPF_PROG_TYPE_FLOW_DISSECTOR:
3226 ret = netns_bpf_prog_attach(attr, prog);
3227 break;
3228 case BPF_PROG_TYPE_CGROUP_DEVICE:
3229 case BPF_PROG_TYPE_CGROUP_SKB:
3230 case BPF_PROG_TYPE_CGROUP_SOCK:
3231 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3232 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3233 case BPF_PROG_TYPE_CGROUP_SYSCTL:
3234 case BPF_PROG_TYPE_SOCK_OPS:
3235 ret = cgroup_bpf_prog_attach(attr, ptype, prog);
3236 break;
3237 default:
3238 ret = -EINVAL;
3239 }
3240
3241 if (ret)
3242 bpf_prog_put(prog);
3243 return ret;
3244 }
3245
3246 #define BPF_PROG_DETACH_LAST_FIELD attach_type
3247
bpf_prog_detach(const union bpf_attr * attr)3248 static int bpf_prog_detach(const union bpf_attr *attr)
3249 {
3250 enum bpf_prog_type ptype;
3251
3252 if (CHECK_ATTR(BPF_PROG_DETACH))
3253 return -EINVAL;
3254
3255 ptype = attach_type_to_prog_type(attr->attach_type);
3256
3257 switch (ptype) {
3258 case BPF_PROG_TYPE_SK_MSG:
3259 case BPF_PROG_TYPE_SK_SKB:
3260 return sock_map_prog_detach(attr, ptype);
3261 case BPF_PROG_TYPE_LIRC_MODE2:
3262 return lirc_prog_detach(attr);
3263 case BPF_PROG_TYPE_FLOW_DISSECTOR:
3264 return netns_bpf_prog_detach(attr, ptype);
3265 case BPF_PROG_TYPE_CGROUP_DEVICE:
3266 case BPF_PROG_TYPE_CGROUP_SKB:
3267 case BPF_PROG_TYPE_CGROUP_SOCK:
3268 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3269 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3270 case BPF_PROG_TYPE_CGROUP_SYSCTL:
3271 case BPF_PROG_TYPE_SOCK_OPS:
3272 return cgroup_bpf_prog_detach(attr, ptype);
3273 default:
3274 return -EINVAL;
3275 }
3276 }
3277
3278 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
3279
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)3280 static int bpf_prog_query(const union bpf_attr *attr,
3281 union bpf_attr __user *uattr)
3282 {
3283 if (!capable(CAP_NET_ADMIN))
3284 return -EPERM;
3285 if (CHECK_ATTR(BPF_PROG_QUERY))
3286 return -EINVAL;
3287 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
3288 return -EINVAL;
3289
3290 switch (attr->query.attach_type) {
3291 case BPF_CGROUP_INET_INGRESS:
3292 case BPF_CGROUP_INET_EGRESS:
3293 case BPF_CGROUP_INET_SOCK_CREATE:
3294 case BPF_CGROUP_INET_SOCK_RELEASE:
3295 case BPF_CGROUP_INET4_BIND:
3296 case BPF_CGROUP_INET6_BIND:
3297 case BPF_CGROUP_INET4_POST_BIND:
3298 case BPF_CGROUP_INET6_POST_BIND:
3299 case BPF_CGROUP_INET4_CONNECT:
3300 case BPF_CGROUP_INET6_CONNECT:
3301 case BPF_CGROUP_INET4_GETPEERNAME:
3302 case BPF_CGROUP_INET6_GETPEERNAME:
3303 case BPF_CGROUP_INET4_GETSOCKNAME:
3304 case BPF_CGROUP_INET6_GETSOCKNAME:
3305 case BPF_CGROUP_UDP4_SENDMSG:
3306 case BPF_CGROUP_UDP6_SENDMSG:
3307 case BPF_CGROUP_UDP4_RECVMSG:
3308 case BPF_CGROUP_UDP6_RECVMSG:
3309 case BPF_CGROUP_SOCK_OPS:
3310 case BPF_CGROUP_DEVICE:
3311 case BPF_CGROUP_SYSCTL:
3312 case BPF_CGROUP_GETSOCKOPT:
3313 case BPF_CGROUP_SETSOCKOPT:
3314 return cgroup_bpf_prog_query(attr, uattr);
3315 case BPF_LIRC_MODE2:
3316 return lirc_prog_query(attr, uattr);
3317 case BPF_FLOW_DISSECTOR:
3318 case BPF_SK_LOOKUP:
3319 return netns_bpf_prog_query(attr, uattr);
3320 default:
3321 return -EINVAL;
3322 }
3323 }
3324
3325 #define BPF_PROG_TEST_RUN_LAST_FIELD test.cpu
3326
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)3327 static int bpf_prog_test_run(const union bpf_attr *attr,
3328 union bpf_attr __user *uattr)
3329 {
3330 struct bpf_prog *prog;
3331 int ret = -ENOTSUPP;
3332
3333 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
3334 return -EINVAL;
3335
3336 if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
3337 (!attr->test.ctx_size_in && attr->test.ctx_in))
3338 return -EINVAL;
3339
3340 if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
3341 (!attr->test.ctx_size_out && attr->test.ctx_out))
3342 return -EINVAL;
3343
3344 prog = bpf_prog_get(attr->test.prog_fd);
3345 if (IS_ERR(prog))
3346 return PTR_ERR(prog);
3347
3348 if (prog->aux->ops->test_run)
3349 ret = prog->aux->ops->test_run(prog, attr, uattr);
3350
3351 bpf_prog_put(prog);
3352 return ret;
3353 }
3354
3355 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
3356
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)3357 static int bpf_obj_get_next_id(const union bpf_attr *attr,
3358 union bpf_attr __user *uattr,
3359 struct idr *idr,
3360 spinlock_t *lock)
3361 {
3362 u32 next_id = attr->start_id;
3363 int err = 0;
3364
3365 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
3366 return -EINVAL;
3367
3368 if (!capable(CAP_SYS_ADMIN))
3369 return -EPERM;
3370
3371 next_id++;
3372 spin_lock_bh(lock);
3373 if (!idr_get_next(idr, &next_id))
3374 err = -ENOENT;
3375 spin_unlock_bh(lock);
3376
3377 if (!err)
3378 err = put_user(next_id, &uattr->next_id);
3379
3380 return err;
3381 }
3382
bpf_map_get_curr_or_next(u32 * id)3383 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
3384 {
3385 struct bpf_map *map;
3386
3387 spin_lock_bh(&map_idr_lock);
3388 again:
3389 map = idr_get_next(&map_idr, id);
3390 if (map) {
3391 map = __bpf_map_inc_not_zero(map, false);
3392 if (IS_ERR(map)) {
3393 (*id)++;
3394 goto again;
3395 }
3396 }
3397 spin_unlock_bh(&map_idr_lock);
3398
3399 return map;
3400 }
3401
bpf_prog_get_curr_or_next(u32 * id)3402 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
3403 {
3404 struct bpf_prog *prog;
3405
3406 spin_lock_bh(&prog_idr_lock);
3407 again:
3408 prog = idr_get_next(&prog_idr, id);
3409 if (prog) {
3410 prog = bpf_prog_inc_not_zero(prog);
3411 if (IS_ERR(prog)) {
3412 (*id)++;
3413 goto again;
3414 }
3415 }
3416 spin_unlock_bh(&prog_idr_lock);
3417
3418 return prog;
3419 }
3420
3421 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
3422
bpf_prog_by_id(u32 id)3423 struct bpf_prog *bpf_prog_by_id(u32 id)
3424 {
3425 struct bpf_prog *prog;
3426
3427 if (!id)
3428 return ERR_PTR(-ENOENT);
3429
3430 spin_lock_bh(&prog_idr_lock);
3431 prog = idr_find(&prog_idr, id);
3432 if (prog)
3433 prog = bpf_prog_inc_not_zero(prog);
3434 else
3435 prog = ERR_PTR(-ENOENT);
3436 spin_unlock_bh(&prog_idr_lock);
3437 return prog;
3438 }
3439
bpf_prog_get_fd_by_id(const union bpf_attr * attr)3440 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
3441 {
3442 struct bpf_prog *prog;
3443 u32 id = attr->prog_id;
3444 int fd;
3445
3446 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
3447 return -EINVAL;
3448
3449 if (!capable(CAP_SYS_ADMIN))
3450 return -EPERM;
3451
3452 prog = bpf_prog_by_id(id);
3453 if (IS_ERR(prog))
3454 return PTR_ERR(prog);
3455
3456 fd = bpf_prog_new_fd(prog);
3457 if (fd < 0)
3458 bpf_prog_put(prog);
3459
3460 return fd;
3461 }
3462
3463 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
3464
bpf_map_get_fd_by_id(const union bpf_attr * attr)3465 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
3466 {
3467 struct bpf_map *map;
3468 u32 id = attr->map_id;
3469 int f_flags;
3470 int fd;
3471
3472 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
3473 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
3474 return -EINVAL;
3475
3476 if (!capable(CAP_SYS_ADMIN))
3477 return -EPERM;
3478
3479 f_flags = bpf_get_file_flag(attr->open_flags);
3480 if (f_flags < 0)
3481 return f_flags;
3482
3483 spin_lock_bh(&map_idr_lock);
3484 map = idr_find(&map_idr, id);
3485 if (map)
3486 map = __bpf_map_inc_not_zero(map, true);
3487 else
3488 map = ERR_PTR(-ENOENT);
3489 spin_unlock_bh(&map_idr_lock);
3490
3491 if (IS_ERR(map))
3492 return PTR_ERR(map);
3493
3494 fd = bpf_map_new_fd(map, f_flags);
3495 if (fd < 0)
3496 bpf_map_put_with_uref(map);
3497
3498 return fd;
3499 }
3500
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)3501 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
3502 unsigned long addr, u32 *off,
3503 u32 *type)
3504 {
3505 const struct bpf_map *map;
3506 int i;
3507
3508 mutex_lock(&prog->aux->used_maps_mutex);
3509 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
3510 map = prog->aux->used_maps[i];
3511 if (map == (void *)addr) {
3512 *type = BPF_PSEUDO_MAP_FD;
3513 goto out;
3514 }
3515 if (!map->ops->map_direct_value_meta)
3516 continue;
3517 if (!map->ops->map_direct_value_meta(map, addr, off)) {
3518 *type = BPF_PSEUDO_MAP_VALUE;
3519 goto out;
3520 }
3521 }
3522 map = NULL;
3523
3524 out:
3525 mutex_unlock(&prog->aux->used_maps_mutex);
3526 return map;
3527 }
3528
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)3529 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
3530 const struct cred *f_cred)
3531 {
3532 const struct bpf_map *map;
3533 struct bpf_insn *insns;
3534 u32 off, type;
3535 u64 imm;
3536 u8 code;
3537 int i;
3538
3539 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
3540 GFP_USER);
3541 if (!insns)
3542 return insns;
3543
3544 for (i = 0; i < prog->len; i++) {
3545 code = insns[i].code;
3546
3547 if (code == (BPF_JMP | BPF_TAIL_CALL)) {
3548 insns[i].code = BPF_JMP | BPF_CALL;
3549 insns[i].imm = BPF_FUNC_tail_call;
3550 /* fall-through */
3551 }
3552 if (code == (BPF_JMP | BPF_CALL) ||
3553 code == (BPF_JMP | BPF_CALL_ARGS)) {
3554 if (code == (BPF_JMP | BPF_CALL_ARGS))
3555 insns[i].code = BPF_JMP | BPF_CALL;
3556 if (!bpf_dump_raw_ok(f_cred))
3557 insns[i].imm = 0;
3558 continue;
3559 }
3560 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
3561 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
3562 continue;
3563 }
3564
3565 if (code != (BPF_LD | BPF_IMM | BPF_DW))
3566 continue;
3567
3568 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
3569 map = bpf_map_from_imm(prog, imm, &off, &type);
3570 if (map) {
3571 insns[i].src_reg = type;
3572 insns[i].imm = map->id;
3573 insns[i + 1].imm = off;
3574 continue;
3575 }
3576 }
3577
3578 return insns;
3579 }
3580
set_info_rec_size(struct bpf_prog_info * info)3581 static int set_info_rec_size(struct bpf_prog_info *info)
3582 {
3583 /*
3584 * Ensure info.*_rec_size is the same as kernel expected size
3585 *
3586 * or
3587 *
3588 * Only allow zero *_rec_size if both _rec_size and _cnt are
3589 * zero. In this case, the kernel will set the expected
3590 * _rec_size back to the info.
3591 */
3592
3593 if ((info->nr_func_info || info->func_info_rec_size) &&
3594 info->func_info_rec_size != sizeof(struct bpf_func_info))
3595 return -EINVAL;
3596
3597 if ((info->nr_line_info || info->line_info_rec_size) &&
3598 info->line_info_rec_size != sizeof(struct bpf_line_info))
3599 return -EINVAL;
3600
3601 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
3602 info->jited_line_info_rec_size != sizeof(__u64))
3603 return -EINVAL;
3604
3605 info->func_info_rec_size = sizeof(struct bpf_func_info);
3606 info->line_info_rec_size = sizeof(struct bpf_line_info);
3607 info->jited_line_info_rec_size = sizeof(__u64);
3608
3609 return 0;
3610 }
3611
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)3612 static int bpf_prog_get_info_by_fd(struct file *file,
3613 struct bpf_prog *prog,
3614 const union bpf_attr *attr,
3615 union bpf_attr __user *uattr)
3616 {
3617 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3618 struct bpf_prog_info info;
3619 u32 info_len = attr->info.info_len;
3620 struct bpf_prog_kstats stats;
3621 char __user *uinsns;
3622 u32 ulen;
3623 int err;
3624
3625 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3626 if (err)
3627 return err;
3628 info_len = min_t(u32, sizeof(info), info_len);
3629
3630 memset(&info, 0, sizeof(info));
3631 if (copy_from_user(&info, uinfo, info_len))
3632 return -EFAULT;
3633
3634 info.type = prog->type;
3635 info.id = prog->aux->id;
3636 info.load_time = prog->aux->load_time;
3637 info.created_by_uid = from_kuid_munged(current_user_ns(),
3638 prog->aux->user->uid);
3639 info.gpl_compatible = prog->gpl_compatible;
3640
3641 memcpy(info.tag, prog->tag, sizeof(prog->tag));
3642 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
3643
3644 mutex_lock(&prog->aux->used_maps_mutex);
3645 ulen = info.nr_map_ids;
3646 info.nr_map_ids = prog->aux->used_map_cnt;
3647 ulen = min_t(u32, info.nr_map_ids, ulen);
3648 if (ulen) {
3649 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
3650 u32 i;
3651
3652 for (i = 0; i < ulen; i++)
3653 if (put_user(prog->aux->used_maps[i]->id,
3654 &user_map_ids[i])) {
3655 mutex_unlock(&prog->aux->used_maps_mutex);
3656 return -EFAULT;
3657 }
3658 }
3659 mutex_unlock(&prog->aux->used_maps_mutex);
3660
3661 err = set_info_rec_size(&info);
3662 if (err)
3663 return err;
3664
3665 bpf_prog_get_stats(prog, &stats);
3666 info.run_time_ns = stats.nsecs;
3667 info.run_cnt = stats.cnt;
3668 info.recursion_misses = stats.misses;
3669
3670 info.verified_insns = prog->aux->verified_insns;
3671
3672 if (!bpf_capable()) {
3673 info.jited_prog_len = 0;
3674 info.xlated_prog_len = 0;
3675 info.nr_jited_ksyms = 0;
3676 info.nr_jited_func_lens = 0;
3677 info.nr_func_info = 0;
3678 info.nr_line_info = 0;
3679 info.nr_jited_line_info = 0;
3680 goto done;
3681 }
3682
3683 ulen = info.xlated_prog_len;
3684 info.xlated_prog_len = bpf_prog_insn_size(prog);
3685 if (info.xlated_prog_len && ulen) {
3686 struct bpf_insn *insns_sanitized;
3687 bool fault;
3688
3689 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
3690 info.xlated_prog_insns = 0;
3691 goto done;
3692 }
3693 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
3694 if (!insns_sanitized)
3695 return -ENOMEM;
3696 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
3697 ulen = min_t(u32, info.xlated_prog_len, ulen);
3698 fault = copy_to_user(uinsns, insns_sanitized, ulen);
3699 kfree(insns_sanitized);
3700 if (fault)
3701 return -EFAULT;
3702 }
3703
3704 if (bpf_prog_is_dev_bound(prog->aux)) {
3705 err = bpf_prog_offload_info_fill(&info, prog);
3706 if (err)
3707 return err;
3708 goto done;
3709 }
3710
3711 /* NOTE: the following code is supposed to be skipped for offload.
3712 * bpf_prog_offload_info_fill() is the place to fill similar fields
3713 * for offload.
3714 */
3715 ulen = info.jited_prog_len;
3716 if (prog->aux->func_cnt) {
3717 u32 i;
3718
3719 info.jited_prog_len = 0;
3720 for (i = 0; i < prog->aux->func_cnt; i++)
3721 info.jited_prog_len += prog->aux->func[i]->jited_len;
3722 } else {
3723 info.jited_prog_len = prog->jited_len;
3724 }
3725
3726 if (info.jited_prog_len && ulen) {
3727 if (bpf_dump_raw_ok(file->f_cred)) {
3728 uinsns = u64_to_user_ptr(info.jited_prog_insns);
3729 ulen = min_t(u32, info.jited_prog_len, ulen);
3730
3731 /* for multi-function programs, copy the JITed
3732 * instructions for all the functions
3733 */
3734 if (prog->aux->func_cnt) {
3735 u32 len, free, i;
3736 u8 *img;
3737
3738 free = ulen;
3739 for (i = 0; i < prog->aux->func_cnt; i++) {
3740 len = prog->aux->func[i]->jited_len;
3741 len = min_t(u32, len, free);
3742 img = (u8 *) prog->aux->func[i]->bpf_func;
3743 if (copy_to_user(uinsns, img, len))
3744 return -EFAULT;
3745 uinsns += len;
3746 free -= len;
3747 if (!free)
3748 break;
3749 }
3750 } else {
3751 if (copy_to_user(uinsns, prog->bpf_func, ulen))
3752 return -EFAULT;
3753 }
3754 } else {
3755 info.jited_prog_insns = 0;
3756 }
3757 }
3758
3759 ulen = info.nr_jited_ksyms;
3760 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
3761 if (ulen) {
3762 if (bpf_dump_raw_ok(file->f_cred)) {
3763 unsigned long ksym_addr;
3764 u64 __user *user_ksyms;
3765 u32 i;
3766
3767 /* copy the address of the kernel symbol
3768 * corresponding to each function
3769 */
3770 ulen = min_t(u32, info.nr_jited_ksyms, ulen);
3771 user_ksyms = u64_to_user_ptr(info.jited_ksyms);
3772 if (prog->aux->func_cnt) {
3773 for (i = 0; i < ulen; i++) {
3774 ksym_addr = (unsigned long)
3775 prog->aux->func[i]->bpf_func;
3776 if (put_user((u64) ksym_addr,
3777 &user_ksyms[i]))
3778 return -EFAULT;
3779 }
3780 } else {
3781 ksym_addr = (unsigned long) prog->bpf_func;
3782 if (put_user((u64) ksym_addr, &user_ksyms[0]))
3783 return -EFAULT;
3784 }
3785 } else {
3786 info.jited_ksyms = 0;
3787 }
3788 }
3789
3790 ulen = info.nr_jited_func_lens;
3791 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
3792 if (ulen) {
3793 if (bpf_dump_raw_ok(file->f_cred)) {
3794 u32 __user *user_lens;
3795 u32 func_len, i;
3796
3797 /* copy the JITed image lengths for each function */
3798 ulen = min_t(u32, info.nr_jited_func_lens, ulen);
3799 user_lens = u64_to_user_ptr(info.jited_func_lens);
3800 if (prog->aux->func_cnt) {
3801 for (i = 0; i < ulen; i++) {
3802 func_len =
3803 prog->aux->func[i]->jited_len;
3804 if (put_user(func_len, &user_lens[i]))
3805 return -EFAULT;
3806 }
3807 } else {
3808 func_len = prog->jited_len;
3809 if (put_user(func_len, &user_lens[0]))
3810 return -EFAULT;
3811 }
3812 } else {
3813 info.jited_func_lens = 0;
3814 }
3815 }
3816
3817 if (prog->aux->btf)
3818 info.btf_id = btf_obj_id(prog->aux->btf);
3819
3820 ulen = info.nr_func_info;
3821 info.nr_func_info = prog->aux->func_info_cnt;
3822 if (info.nr_func_info && ulen) {
3823 char __user *user_finfo;
3824
3825 user_finfo = u64_to_user_ptr(info.func_info);
3826 ulen = min_t(u32, info.nr_func_info, ulen);
3827 if (copy_to_user(user_finfo, prog->aux->func_info,
3828 info.func_info_rec_size * ulen))
3829 return -EFAULT;
3830 }
3831
3832 ulen = info.nr_line_info;
3833 info.nr_line_info = prog->aux->nr_linfo;
3834 if (info.nr_line_info && ulen) {
3835 __u8 __user *user_linfo;
3836
3837 user_linfo = u64_to_user_ptr(info.line_info);
3838 ulen = min_t(u32, info.nr_line_info, ulen);
3839 if (copy_to_user(user_linfo, prog->aux->linfo,
3840 info.line_info_rec_size * ulen))
3841 return -EFAULT;
3842 }
3843
3844 ulen = info.nr_jited_line_info;
3845 if (prog->aux->jited_linfo)
3846 info.nr_jited_line_info = prog->aux->nr_linfo;
3847 else
3848 info.nr_jited_line_info = 0;
3849 if (info.nr_jited_line_info && ulen) {
3850 if (bpf_dump_raw_ok(file->f_cred)) {
3851 __u64 __user *user_linfo;
3852 u32 i;
3853
3854 user_linfo = u64_to_user_ptr(info.jited_line_info);
3855 ulen = min_t(u32, info.nr_jited_line_info, ulen);
3856 for (i = 0; i < ulen; i++) {
3857 if (put_user((__u64)(long)prog->aux->jited_linfo[i],
3858 &user_linfo[i]))
3859 return -EFAULT;
3860 }
3861 } else {
3862 info.jited_line_info = 0;
3863 }
3864 }
3865
3866 ulen = info.nr_prog_tags;
3867 info.nr_prog_tags = prog->aux->func_cnt ? : 1;
3868 if (ulen) {
3869 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
3870 u32 i;
3871
3872 user_prog_tags = u64_to_user_ptr(info.prog_tags);
3873 ulen = min_t(u32, info.nr_prog_tags, ulen);
3874 if (prog->aux->func_cnt) {
3875 for (i = 0; i < ulen; i++) {
3876 if (copy_to_user(user_prog_tags[i],
3877 prog->aux->func[i]->tag,
3878 BPF_TAG_SIZE))
3879 return -EFAULT;
3880 }
3881 } else {
3882 if (copy_to_user(user_prog_tags[0],
3883 prog->tag, BPF_TAG_SIZE))
3884 return -EFAULT;
3885 }
3886 }
3887
3888 done:
3889 if (copy_to_user(uinfo, &info, info_len) ||
3890 put_user(info_len, &uattr->info.info_len))
3891 return -EFAULT;
3892
3893 return 0;
3894 }
3895
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)3896 static int bpf_map_get_info_by_fd(struct file *file,
3897 struct bpf_map *map,
3898 const union bpf_attr *attr,
3899 union bpf_attr __user *uattr)
3900 {
3901 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3902 struct bpf_map_info info;
3903 u32 info_len = attr->info.info_len;
3904 int err;
3905
3906 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3907 if (err)
3908 return err;
3909 info_len = min_t(u32, sizeof(info), info_len);
3910
3911 memset(&info, 0, sizeof(info));
3912 info.type = map->map_type;
3913 info.id = map->id;
3914 info.key_size = map->key_size;
3915 info.value_size = map->value_size;
3916 info.max_entries = map->max_entries;
3917 info.map_flags = map->map_flags;
3918 info.map_extra = map->map_extra;
3919 memcpy(info.name, map->name, sizeof(map->name));
3920
3921 if (map->btf) {
3922 info.btf_id = btf_obj_id(map->btf);
3923 info.btf_key_type_id = map->btf_key_type_id;
3924 info.btf_value_type_id = map->btf_value_type_id;
3925 }
3926 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
3927
3928 if (bpf_map_is_dev_bound(map)) {
3929 err = bpf_map_offload_info_fill(&info, map);
3930 if (err)
3931 return err;
3932 }
3933
3934 if (copy_to_user(uinfo, &info, info_len) ||
3935 put_user(info_len, &uattr->info.info_len))
3936 return -EFAULT;
3937
3938 return 0;
3939 }
3940
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)3941 static int bpf_btf_get_info_by_fd(struct file *file,
3942 struct btf *btf,
3943 const union bpf_attr *attr,
3944 union bpf_attr __user *uattr)
3945 {
3946 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3947 u32 info_len = attr->info.info_len;
3948 int err;
3949
3950 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
3951 if (err)
3952 return err;
3953
3954 return btf_get_info_by_fd(btf, attr, uattr);
3955 }
3956
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)3957 static int bpf_link_get_info_by_fd(struct file *file,
3958 struct bpf_link *link,
3959 const union bpf_attr *attr,
3960 union bpf_attr __user *uattr)
3961 {
3962 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3963 struct bpf_link_info info;
3964 u32 info_len = attr->info.info_len;
3965 int err;
3966
3967 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3968 if (err)
3969 return err;
3970 info_len = min_t(u32, sizeof(info), info_len);
3971
3972 memset(&info, 0, sizeof(info));
3973 if (copy_from_user(&info, uinfo, info_len))
3974 return -EFAULT;
3975
3976 info.type = link->type;
3977 info.id = link->id;
3978 info.prog_id = link->prog->aux->id;
3979
3980 if (link->ops->fill_link_info) {
3981 err = link->ops->fill_link_info(link, &info);
3982 if (err)
3983 return err;
3984 }
3985
3986 if (copy_to_user(uinfo, &info, info_len) ||
3987 put_user(info_len, &uattr->info.info_len))
3988 return -EFAULT;
3989
3990 return 0;
3991 }
3992
3993
3994 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
3995
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)3996 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
3997 union bpf_attr __user *uattr)
3998 {
3999 int ufd = attr->info.bpf_fd;
4000 struct fd f;
4001 int err;
4002
4003 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
4004 return -EINVAL;
4005
4006 f = fdget(ufd);
4007 if (!f.file)
4008 return -EBADFD;
4009
4010 if (f.file->f_op == &bpf_prog_fops)
4011 err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
4012 uattr);
4013 else if (f.file->f_op == &bpf_map_fops)
4014 err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
4015 uattr);
4016 else if (f.file->f_op == &btf_fops)
4017 err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
4018 else if (f.file->f_op == &bpf_link_fops)
4019 err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
4020 attr, uattr);
4021 else
4022 err = -EINVAL;
4023
4024 fdput(f);
4025 return err;
4026 }
4027
4028 #define BPF_BTF_LOAD_LAST_FIELD btf_log_level
4029
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr)4030 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr)
4031 {
4032 if (CHECK_ATTR(BPF_BTF_LOAD))
4033 return -EINVAL;
4034
4035 if (!bpf_capable())
4036 return -EPERM;
4037
4038 return btf_new_fd(attr, uattr);
4039 }
4040
4041 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
4042
bpf_btf_get_fd_by_id(const union bpf_attr * attr)4043 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
4044 {
4045 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
4046 return -EINVAL;
4047
4048 if (!capable(CAP_SYS_ADMIN))
4049 return -EPERM;
4050
4051 return btf_get_fd_by_id(attr->btf_id);
4052 }
4053
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)4054 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
4055 union bpf_attr __user *uattr,
4056 u32 prog_id, u32 fd_type,
4057 const char *buf, u64 probe_offset,
4058 u64 probe_addr)
4059 {
4060 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
4061 u32 len = buf ? strlen(buf) : 0, input_len;
4062 int err = 0;
4063
4064 if (put_user(len, &uattr->task_fd_query.buf_len))
4065 return -EFAULT;
4066 input_len = attr->task_fd_query.buf_len;
4067 if (input_len && ubuf) {
4068 if (!len) {
4069 /* nothing to copy, just make ubuf NULL terminated */
4070 char zero = '\0';
4071
4072 if (put_user(zero, ubuf))
4073 return -EFAULT;
4074 } else if (input_len >= len + 1) {
4075 /* ubuf can hold the string with NULL terminator */
4076 if (copy_to_user(ubuf, buf, len + 1))
4077 return -EFAULT;
4078 } else {
4079 /* ubuf cannot hold the string with NULL terminator,
4080 * do a partial copy with NULL terminator.
4081 */
4082 char zero = '\0';
4083
4084 err = -ENOSPC;
4085 if (copy_to_user(ubuf, buf, input_len - 1))
4086 return -EFAULT;
4087 if (put_user(zero, ubuf + input_len - 1))
4088 return -EFAULT;
4089 }
4090 }
4091
4092 if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
4093 put_user(fd_type, &uattr->task_fd_query.fd_type) ||
4094 put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
4095 put_user(probe_addr, &uattr->task_fd_query.probe_addr))
4096 return -EFAULT;
4097
4098 return err;
4099 }
4100
4101 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
4102
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4103 static int bpf_task_fd_query(const union bpf_attr *attr,
4104 union bpf_attr __user *uattr)
4105 {
4106 pid_t pid = attr->task_fd_query.pid;
4107 u32 fd = attr->task_fd_query.fd;
4108 const struct perf_event *event;
4109 struct task_struct *task;
4110 struct file *file;
4111 int err;
4112
4113 if (CHECK_ATTR(BPF_TASK_FD_QUERY))
4114 return -EINVAL;
4115
4116 if (!capable(CAP_SYS_ADMIN))
4117 return -EPERM;
4118
4119 if (attr->task_fd_query.flags != 0)
4120 return -EINVAL;
4121
4122 task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
4123 if (!task)
4124 return -ENOENT;
4125
4126 err = 0;
4127 file = fget_task(task, fd);
4128 put_task_struct(task);
4129 if (!file)
4130 return -EBADF;
4131
4132 if (file->f_op == &bpf_link_fops) {
4133 struct bpf_link *link = file->private_data;
4134
4135 if (link->ops == &bpf_raw_tp_link_lops) {
4136 struct bpf_raw_tp_link *raw_tp =
4137 container_of(link, struct bpf_raw_tp_link, link);
4138 struct bpf_raw_event_map *btp = raw_tp->btp;
4139
4140 err = bpf_task_fd_query_copy(attr, uattr,
4141 raw_tp->link.prog->aux->id,
4142 BPF_FD_TYPE_RAW_TRACEPOINT,
4143 btp->tp->name, 0, 0);
4144 goto put_file;
4145 }
4146 goto out_not_supp;
4147 }
4148
4149 event = perf_get_event(file);
4150 if (!IS_ERR(event)) {
4151 u64 probe_offset, probe_addr;
4152 u32 prog_id, fd_type;
4153 const char *buf;
4154
4155 err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
4156 &buf, &probe_offset,
4157 &probe_addr);
4158 if (!err)
4159 err = bpf_task_fd_query_copy(attr, uattr, prog_id,
4160 fd_type, buf,
4161 probe_offset,
4162 probe_addr);
4163 goto put_file;
4164 }
4165
4166 out_not_supp:
4167 err = -ENOTSUPP;
4168 put_file:
4169 fput(file);
4170 return err;
4171 }
4172
4173 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
4174
4175 #define BPF_DO_BATCH(fn) \
4176 do { \
4177 if (!fn) { \
4178 err = -ENOTSUPP; \
4179 goto err_put; \
4180 } \
4181 err = fn(map, attr, uattr); \
4182 } while (0)
4183
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)4184 static int bpf_map_do_batch(const union bpf_attr *attr,
4185 union bpf_attr __user *uattr,
4186 int cmd)
4187 {
4188 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH ||
4189 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
4190 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
4191 struct bpf_map *map;
4192 int err, ufd;
4193 struct fd f;
4194
4195 if (CHECK_ATTR(BPF_MAP_BATCH))
4196 return -EINVAL;
4197
4198 ufd = attr->batch.map_fd;
4199 f = fdget(ufd);
4200 map = __bpf_map_get(f);
4201 if (IS_ERR(map))
4202 return PTR_ERR(map);
4203 if (has_write)
4204 bpf_map_write_active_inc(map);
4205 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
4206 err = -EPERM;
4207 goto err_put;
4208 }
4209 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
4210 err = -EPERM;
4211 goto err_put;
4212 }
4213
4214 if (cmd == BPF_MAP_LOOKUP_BATCH)
4215 BPF_DO_BATCH(map->ops->map_lookup_batch);
4216 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
4217 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch);
4218 else if (cmd == BPF_MAP_UPDATE_BATCH)
4219 BPF_DO_BATCH(map->ops->map_update_batch);
4220 else
4221 BPF_DO_BATCH(map->ops->map_delete_batch);
4222 err_put:
4223 if (has_write)
4224 bpf_map_write_active_dec(map);
4225 fdput(f);
4226 return err;
4227 }
4228
tracing_bpf_link_attach(const union bpf_attr * attr,bpfptr_t uattr,struct bpf_prog * prog)4229 static int tracing_bpf_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
4230 struct bpf_prog *prog)
4231 {
4232 if (attr->link_create.attach_type != prog->expected_attach_type)
4233 return -EINVAL;
4234
4235 if (prog->expected_attach_type == BPF_TRACE_ITER)
4236 return bpf_iter_link_attach(attr, uattr, prog);
4237 else if (prog->type == BPF_PROG_TYPE_EXT)
4238 return bpf_tracing_prog_attach(prog,
4239 attr->link_create.target_fd,
4240 attr->link_create.target_btf_id);
4241 return -EINVAL;
4242 }
4243
4244 #define BPF_LINK_CREATE_LAST_FIELD link_create.iter_info_len
link_create(union bpf_attr * attr,bpfptr_t uattr)4245 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
4246 {
4247 enum bpf_prog_type ptype;
4248 struct bpf_prog *prog;
4249 int ret;
4250
4251 if (CHECK_ATTR(BPF_LINK_CREATE))
4252 return -EINVAL;
4253
4254 prog = bpf_prog_get(attr->link_create.prog_fd);
4255 if (IS_ERR(prog))
4256 return PTR_ERR(prog);
4257
4258 ret = bpf_prog_attach_check_attach_type(prog,
4259 attr->link_create.attach_type);
4260 if (ret)
4261 goto out;
4262
4263 switch (prog->type) {
4264 case BPF_PROG_TYPE_EXT:
4265 ret = tracing_bpf_link_attach(attr, uattr, prog);
4266 goto out;
4267 case BPF_PROG_TYPE_PERF_EVENT:
4268 case BPF_PROG_TYPE_KPROBE:
4269 case BPF_PROG_TYPE_TRACEPOINT:
4270 if (attr->link_create.attach_type != BPF_PERF_EVENT) {
4271 ret = -EINVAL;
4272 goto out;
4273 }
4274 ptype = prog->type;
4275 break;
4276 default:
4277 ptype = attach_type_to_prog_type(attr->link_create.attach_type);
4278 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) {
4279 ret = -EINVAL;
4280 goto out;
4281 }
4282 break;
4283 }
4284
4285 switch (ptype) {
4286 case BPF_PROG_TYPE_CGROUP_SKB:
4287 case BPF_PROG_TYPE_CGROUP_SOCK:
4288 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4289 case BPF_PROG_TYPE_SOCK_OPS:
4290 case BPF_PROG_TYPE_CGROUP_DEVICE:
4291 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4292 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4293 ret = cgroup_bpf_link_attach(attr, prog);
4294 break;
4295 case BPF_PROG_TYPE_TRACING:
4296 ret = tracing_bpf_link_attach(attr, uattr, prog);
4297 break;
4298 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4299 case BPF_PROG_TYPE_SK_LOOKUP:
4300 ret = netns_bpf_link_create(attr, prog);
4301 break;
4302 #ifdef CONFIG_NET
4303 case BPF_PROG_TYPE_XDP:
4304 ret = bpf_xdp_link_attach(attr, prog);
4305 break;
4306 #endif
4307 #ifdef CONFIG_PERF_EVENTS
4308 case BPF_PROG_TYPE_PERF_EVENT:
4309 case BPF_PROG_TYPE_TRACEPOINT:
4310 case BPF_PROG_TYPE_KPROBE:
4311 ret = bpf_perf_link_attach(attr, prog);
4312 break;
4313 #endif
4314 default:
4315 ret = -EINVAL;
4316 }
4317
4318 out:
4319 if (ret < 0)
4320 bpf_prog_put(prog);
4321 return ret;
4322 }
4323
4324 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
4325
link_update(union bpf_attr * attr)4326 static int link_update(union bpf_attr *attr)
4327 {
4328 struct bpf_prog *old_prog = NULL, *new_prog;
4329 struct bpf_link *link;
4330 u32 flags;
4331 int ret;
4332
4333 if (CHECK_ATTR(BPF_LINK_UPDATE))
4334 return -EINVAL;
4335
4336 flags = attr->link_update.flags;
4337 if (flags & ~BPF_F_REPLACE)
4338 return -EINVAL;
4339
4340 link = bpf_link_get_from_fd(attr->link_update.link_fd);
4341 if (IS_ERR(link))
4342 return PTR_ERR(link);
4343
4344 new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
4345 if (IS_ERR(new_prog)) {
4346 ret = PTR_ERR(new_prog);
4347 goto out_put_link;
4348 }
4349
4350 if (flags & BPF_F_REPLACE) {
4351 old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
4352 if (IS_ERR(old_prog)) {
4353 ret = PTR_ERR(old_prog);
4354 old_prog = NULL;
4355 goto out_put_progs;
4356 }
4357 } else if (attr->link_update.old_prog_fd) {
4358 ret = -EINVAL;
4359 goto out_put_progs;
4360 }
4361
4362 if (link->ops->update_prog)
4363 ret = link->ops->update_prog(link, new_prog, old_prog);
4364 else
4365 ret = -EINVAL;
4366
4367 out_put_progs:
4368 if (old_prog)
4369 bpf_prog_put(old_prog);
4370 if (ret)
4371 bpf_prog_put(new_prog);
4372 out_put_link:
4373 bpf_link_put(link);
4374 return ret;
4375 }
4376
4377 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
4378
link_detach(union bpf_attr * attr)4379 static int link_detach(union bpf_attr *attr)
4380 {
4381 struct bpf_link *link;
4382 int ret;
4383
4384 if (CHECK_ATTR(BPF_LINK_DETACH))
4385 return -EINVAL;
4386
4387 link = bpf_link_get_from_fd(attr->link_detach.link_fd);
4388 if (IS_ERR(link))
4389 return PTR_ERR(link);
4390
4391 if (link->ops->detach)
4392 ret = link->ops->detach(link);
4393 else
4394 ret = -EOPNOTSUPP;
4395
4396 bpf_link_put(link);
4397 return ret;
4398 }
4399
bpf_link_inc_not_zero(struct bpf_link * link)4400 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
4401 {
4402 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
4403 }
4404
bpf_link_by_id(u32 id)4405 struct bpf_link *bpf_link_by_id(u32 id)
4406 {
4407 struct bpf_link *link;
4408
4409 if (!id)
4410 return ERR_PTR(-ENOENT);
4411
4412 spin_lock_bh(&link_idr_lock);
4413 /* before link is "settled", ID is 0, pretend it doesn't exist yet */
4414 link = idr_find(&link_idr, id);
4415 if (link) {
4416 if (link->id)
4417 link = bpf_link_inc_not_zero(link);
4418 else
4419 link = ERR_PTR(-EAGAIN);
4420 } else {
4421 link = ERR_PTR(-ENOENT);
4422 }
4423 spin_unlock_bh(&link_idr_lock);
4424 return link;
4425 }
4426
4427 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
4428
bpf_link_get_fd_by_id(const union bpf_attr * attr)4429 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
4430 {
4431 struct bpf_link *link;
4432 u32 id = attr->link_id;
4433 int fd;
4434
4435 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
4436 return -EINVAL;
4437
4438 if (!capable(CAP_SYS_ADMIN))
4439 return -EPERM;
4440
4441 link = bpf_link_by_id(id);
4442 if (IS_ERR(link))
4443 return PTR_ERR(link);
4444
4445 fd = bpf_link_new_fd(link);
4446 if (fd < 0)
4447 bpf_link_put(link);
4448
4449 return fd;
4450 }
4451
4452 DEFINE_MUTEX(bpf_stats_enabled_mutex);
4453
bpf_stats_release(struct inode * inode,struct file * file)4454 static int bpf_stats_release(struct inode *inode, struct file *file)
4455 {
4456 mutex_lock(&bpf_stats_enabled_mutex);
4457 static_key_slow_dec(&bpf_stats_enabled_key.key);
4458 mutex_unlock(&bpf_stats_enabled_mutex);
4459 return 0;
4460 }
4461
4462 static const struct file_operations bpf_stats_fops = {
4463 .release = bpf_stats_release,
4464 };
4465
bpf_enable_runtime_stats(void)4466 static int bpf_enable_runtime_stats(void)
4467 {
4468 int fd;
4469
4470 mutex_lock(&bpf_stats_enabled_mutex);
4471
4472 /* Set a very high limit to avoid overflow */
4473 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
4474 mutex_unlock(&bpf_stats_enabled_mutex);
4475 return -EBUSY;
4476 }
4477
4478 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
4479 if (fd >= 0)
4480 static_key_slow_inc(&bpf_stats_enabled_key.key);
4481
4482 mutex_unlock(&bpf_stats_enabled_mutex);
4483 return fd;
4484 }
4485
4486 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
4487
bpf_enable_stats(union bpf_attr * attr)4488 static int bpf_enable_stats(union bpf_attr *attr)
4489 {
4490
4491 if (CHECK_ATTR(BPF_ENABLE_STATS))
4492 return -EINVAL;
4493
4494 if (!capable(CAP_SYS_ADMIN))
4495 return -EPERM;
4496
4497 switch (attr->enable_stats.type) {
4498 case BPF_STATS_RUN_TIME:
4499 return bpf_enable_runtime_stats();
4500 default:
4501 break;
4502 }
4503 return -EINVAL;
4504 }
4505
4506 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
4507
bpf_iter_create(union bpf_attr * attr)4508 static int bpf_iter_create(union bpf_attr *attr)
4509 {
4510 struct bpf_link *link;
4511 int err;
4512
4513 if (CHECK_ATTR(BPF_ITER_CREATE))
4514 return -EINVAL;
4515
4516 if (attr->iter_create.flags)
4517 return -EINVAL;
4518
4519 link = bpf_link_get_from_fd(attr->iter_create.link_fd);
4520 if (IS_ERR(link))
4521 return PTR_ERR(link);
4522
4523 err = bpf_iter_new_fd(link);
4524 bpf_link_put(link);
4525
4526 return err;
4527 }
4528
4529 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
4530
bpf_prog_bind_map(union bpf_attr * attr)4531 static int bpf_prog_bind_map(union bpf_attr *attr)
4532 {
4533 struct bpf_prog *prog;
4534 struct bpf_map *map;
4535 struct bpf_map **used_maps_old, **used_maps_new;
4536 int i, ret = 0;
4537
4538 if (CHECK_ATTR(BPF_PROG_BIND_MAP))
4539 return -EINVAL;
4540
4541 if (attr->prog_bind_map.flags)
4542 return -EINVAL;
4543
4544 prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
4545 if (IS_ERR(prog))
4546 return PTR_ERR(prog);
4547
4548 map = bpf_map_get(attr->prog_bind_map.map_fd);
4549 if (IS_ERR(map)) {
4550 ret = PTR_ERR(map);
4551 goto out_prog_put;
4552 }
4553
4554 mutex_lock(&prog->aux->used_maps_mutex);
4555
4556 used_maps_old = prog->aux->used_maps;
4557
4558 for (i = 0; i < prog->aux->used_map_cnt; i++)
4559 if (used_maps_old[i] == map) {
4560 bpf_map_put(map);
4561 goto out_unlock;
4562 }
4563
4564 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
4565 sizeof(used_maps_new[0]),
4566 GFP_KERNEL);
4567 if (!used_maps_new) {
4568 ret = -ENOMEM;
4569 goto out_unlock;
4570 }
4571
4572 memcpy(used_maps_new, used_maps_old,
4573 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
4574 used_maps_new[prog->aux->used_map_cnt] = map;
4575
4576 prog->aux->used_map_cnt++;
4577 prog->aux->used_maps = used_maps_new;
4578
4579 kfree(used_maps_old);
4580
4581 out_unlock:
4582 mutex_unlock(&prog->aux->used_maps_mutex);
4583
4584 if (ret)
4585 bpf_map_put(map);
4586 out_prog_put:
4587 bpf_prog_put(prog);
4588 return ret;
4589 }
4590
__sys_bpf(int cmd,bpfptr_t uattr,unsigned int size)4591 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
4592 {
4593 union bpf_attr attr;
4594 int err;
4595
4596 if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
4597 return -EPERM;
4598
4599 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
4600 if (err)
4601 return err;
4602 size = min_t(u32, size, sizeof(attr));
4603
4604 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
4605 memset(&attr, 0, sizeof(attr));
4606 if (copy_from_bpfptr(&attr, uattr, size) != 0)
4607 return -EFAULT;
4608
4609 err = security_bpf(cmd, &attr, size);
4610 if (err < 0)
4611 return err;
4612
4613 switch (cmd) {
4614 case BPF_MAP_CREATE:
4615 err = map_create(&attr);
4616 break;
4617 case BPF_MAP_LOOKUP_ELEM:
4618 err = map_lookup_elem(&attr);
4619 break;
4620 case BPF_MAP_UPDATE_ELEM:
4621 err = map_update_elem(&attr, uattr);
4622 break;
4623 case BPF_MAP_DELETE_ELEM:
4624 err = map_delete_elem(&attr);
4625 break;
4626 case BPF_MAP_GET_NEXT_KEY:
4627 err = map_get_next_key(&attr);
4628 break;
4629 case BPF_MAP_FREEZE:
4630 err = map_freeze(&attr);
4631 break;
4632 case BPF_PROG_LOAD:
4633 err = bpf_prog_load(&attr, uattr);
4634 break;
4635 case BPF_OBJ_PIN:
4636 err = bpf_obj_pin(&attr);
4637 break;
4638 case BPF_OBJ_GET:
4639 err = bpf_obj_get(&attr);
4640 break;
4641 case BPF_PROG_ATTACH:
4642 err = bpf_prog_attach(&attr);
4643 break;
4644 case BPF_PROG_DETACH:
4645 err = bpf_prog_detach(&attr);
4646 break;
4647 case BPF_PROG_QUERY:
4648 err = bpf_prog_query(&attr, uattr.user);
4649 break;
4650 case BPF_PROG_TEST_RUN:
4651 err = bpf_prog_test_run(&attr, uattr.user);
4652 break;
4653 case BPF_PROG_GET_NEXT_ID:
4654 err = bpf_obj_get_next_id(&attr, uattr.user,
4655 &prog_idr, &prog_idr_lock);
4656 break;
4657 case BPF_MAP_GET_NEXT_ID:
4658 err = bpf_obj_get_next_id(&attr, uattr.user,
4659 &map_idr, &map_idr_lock);
4660 break;
4661 case BPF_BTF_GET_NEXT_ID:
4662 err = bpf_obj_get_next_id(&attr, uattr.user,
4663 &btf_idr, &btf_idr_lock);
4664 break;
4665 case BPF_PROG_GET_FD_BY_ID:
4666 err = bpf_prog_get_fd_by_id(&attr);
4667 break;
4668 case BPF_MAP_GET_FD_BY_ID:
4669 err = bpf_map_get_fd_by_id(&attr);
4670 break;
4671 case BPF_OBJ_GET_INFO_BY_FD:
4672 err = bpf_obj_get_info_by_fd(&attr, uattr.user);
4673 break;
4674 case BPF_RAW_TRACEPOINT_OPEN:
4675 err = bpf_raw_tracepoint_open(&attr);
4676 break;
4677 case BPF_BTF_LOAD:
4678 err = bpf_btf_load(&attr, uattr);
4679 break;
4680 case BPF_BTF_GET_FD_BY_ID:
4681 err = bpf_btf_get_fd_by_id(&attr);
4682 break;
4683 case BPF_TASK_FD_QUERY:
4684 err = bpf_task_fd_query(&attr, uattr.user);
4685 break;
4686 case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
4687 err = map_lookup_and_delete_elem(&attr);
4688 break;
4689 case BPF_MAP_LOOKUP_BATCH:
4690 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
4691 break;
4692 case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
4693 err = bpf_map_do_batch(&attr, uattr.user,
4694 BPF_MAP_LOOKUP_AND_DELETE_BATCH);
4695 break;
4696 case BPF_MAP_UPDATE_BATCH:
4697 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
4698 break;
4699 case BPF_MAP_DELETE_BATCH:
4700 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
4701 break;
4702 case BPF_LINK_CREATE:
4703 err = link_create(&attr, uattr);
4704 break;
4705 case BPF_LINK_UPDATE:
4706 err = link_update(&attr);
4707 break;
4708 case BPF_LINK_GET_FD_BY_ID:
4709 err = bpf_link_get_fd_by_id(&attr);
4710 break;
4711 case BPF_LINK_GET_NEXT_ID:
4712 err = bpf_obj_get_next_id(&attr, uattr.user,
4713 &link_idr, &link_idr_lock);
4714 break;
4715 case BPF_ENABLE_STATS:
4716 err = bpf_enable_stats(&attr);
4717 break;
4718 case BPF_ITER_CREATE:
4719 err = bpf_iter_create(&attr);
4720 break;
4721 case BPF_LINK_DETACH:
4722 err = link_detach(&attr);
4723 break;
4724 case BPF_PROG_BIND_MAP:
4725 err = bpf_prog_bind_map(&attr);
4726 break;
4727 default:
4728 err = -EINVAL;
4729 break;
4730 }
4731
4732 return err;
4733 }
4734
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)4735 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
4736 {
4737 return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
4738 }
4739
syscall_prog_is_valid_access(int off,int size,enum bpf_access_type type,const struct bpf_prog * prog,struct bpf_insn_access_aux * info)4740 static bool syscall_prog_is_valid_access(int off, int size,
4741 enum bpf_access_type type,
4742 const struct bpf_prog *prog,
4743 struct bpf_insn_access_aux *info)
4744 {
4745 if (off < 0 || off >= U16_MAX)
4746 return false;
4747 if (off % size != 0)
4748 return false;
4749 return true;
4750 }
4751
BPF_CALL_3(bpf_sys_bpf,int,cmd,void *,attr,u32,attr_size)4752 BPF_CALL_3(bpf_sys_bpf, int, cmd, void *, attr, u32, attr_size)
4753 {
4754 switch (cmd) {
4755 case BPF_MAP_CREATE:
4756 case BPF_MAP_UPDATE_ELEM:
4757 case BPF_MAP_FREEZE:
4758 case BPF_PROG_LOAD:
4759 case BPF_BTF_LOAD:
4760 break;
4761 /* case BPF_PROG_TEST_RUN:
4762 * is not part of this list to prevent recursive test_run
4763 */
4764 default:
4765 return -EINVAL;
4766 }
4767 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
4768 }
4769
4770 static const struct bpf_func_proto bpf_sys_bpf_proto = {
4771 .func = bpf_sys_bpf,
4772 .gpl_only = false,
4773 .ret_type = RET_INTEGER,
4774 .arg1_type = ARG_ANYTHING,
4775 .arg2_type = ARG_PTR_TO_MEM,
4776 .arg3_type = ARG_CONST_SIZE,
4777 };
4778
4779 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)4780 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
4781 {
4782 return bpf_base_func_proto(func_id);
4783 }
4784
BPF_CALL_1(bpf_sys_close,u32,fd)4785 BPF_CALL_1(bpf_sys_close, u32, fd)
4786 {
4787 /* When bpf program calls this helper there should not be
4788 * an fdget() without matching completed fdput().
4789 * This helper is allowed in the following callchain only:
4790 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
4791 */
4792 return close_fd(fd);
4793 }
4794
4795 static const struct bpf_func_proto bpf_sys_close_proto = {
4796 .func = bpf_sys_close,
4797 .gpl_only = false,
4798 .ret_type = RET_INTEGER,
4799 .arg1_type = ARG_ANYTHING,
4800 };
4801
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)4802 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
4803 {
4804 if (flags)
4805 return -EINVAL;
4806
4807 if (name_sz <= 1 || name[name_sz - 1])
4808 return -EINVAL;
4809
4810 if (!bpf_dump_raw_ok(current_cred()))
4811 return -EPERM;
4812
4813 *res = kallsyms_lookup_name(name);
4814 return *res ? 0 : -ENOENT;
4815 }
4816
4817 const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
4818 .func = bpf_kallsyms_lookup_name,
4819 .gpl_only = false,
4820 .ret_type = RET_INTEGER,
4821 .arg1_type = ARG_PTR_TO_MEM,
4822 .arg2_type = ARG_CONST_SIZE,
4823 .arg3_type = ARG_ANYTHING,
4824 .arg4_type = ARG_PTR_TO_LONG,
4825 };
4826
4827 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)4828 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
4829 {
4830 switch (func_id) {
4831 case BPF_FUNC_sys_bpf:
4832 return &bpf_sys_bpf_proto;
4833 case BPF_FUNC_btf_find_by_name_kind:
4834 return &bpf_btf_find_by_name_kind_proto;
4835 case BPF_FUNC_sys_close:
4836 return &bpf_sys_close_proto;
4837 case BPF_FUNC_kallsyms_lookup_name:
4838 return &bpf_kallsyms_lookup_name_proto;
4839 default:
4840 return tracing_prog_func_proto(func_id, prog);
4841 }
4842 }
4843
4844 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
4845 .get_func_proto = syscall_prog_func_proto,
4846 .is_valid_access = syscall_prog_is_valid_access,
4847 };
4848
4849 const struct bpf_prog_ops bpf_syscall_prog_ops = {
4850 .test_run = bpf_prog_test_run_syscall,
4851 };
4852