1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 */
4 #include <crypto/sha2.h>
5 #include <linux/bpf.h>
6 #include <linux/bpf-cgroup.h>
7 #include <linux/bpf_trace.h>
8 #include <linux/bpf_lirc.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bsearch.h>
11 #include <linux/btf.h>
12 #include <linux/hex.h>
13 #include <linux/syscalls.h>
14 #include <linux/slab.h>
15 #include <linux/sched/signal.h>
16 #include <linux/vmalloc.h>
17 #include <linux/mmzone.h>
18 #include <linux/anon_inodes.h>
19 #include <linux/fdtable.h>
20 #include <linux/file.h>
21 #include <linux/fs.h>
22 #include <linux/license.h>
23 #include <linux/filter.h>
24 #include <linux/kernel.h>
25 #include <linux/idr.h>
26 #include <linux/cred.h>
27 #include <linux/timekeeping.h>
28 #include <linux/ctype.h>
29 #include <linux/nospec.h>
30 #include <linux/audit.h>
31 #include <uapi/linux/btf.h>
32 #include <linux/pgtable.h>
33 #include <linux/bpf_lsm.h>
34 #include <linux/poll.h>
35 #include <linux/sort.h>
36 #include <linux/bpf-netns.h>
37 #include <linux/rcupdate_trace.h>
38 #include <linux/memcontrol.h>
39 #include <linux/trace_events.h>
40 #include <linux/tracepoint.h>
41 #include <linux/overflow.h>
42 #include <linux/cookie.h>
43 #include <linux/btf_ids.h>
44
45 #include <net/netfilter/nf_bpf_link.h>
46 #include <net/netkit.h>
47 #include <net/tcx.h>
48
49 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
50 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
51 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
52 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
53 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
54 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
55 IS_FD_HASH(map))
56
57 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY)
58
59 DEFINE_PER_CPU(int, bpf_prog_active);
60 DEFINE_COOKIE(bpf_map_cookie);
61 static DEFINE_IDR(prog_idr);
62 static DEFINE_SPINLOCK(prog_idr_lock);
63 static DEFINE_IDR(map_idr);
64 static DEFINE_SPINLOCK(map_idr_lock);
65 static DEFINE_IDR(link_idr);
66 static DEFINE_SPINLOCK(link_idr_lock);
67
68 int sysctl_unprivileged_bpf_disabled __read_mostly =
69 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
70
71 static const struct bpf_map_ops * const bpf_map_types[] = {
72 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
73 #define BPF_MAP_TYPE(_id, _ops) \
74 [_id] = &_ops,
75 #define BPF_LINK_TYPE(_id, _name)
76 #include <linux/bpf_types.h>
77 #undef BPF_PROG_TYPE
78 #undef BPF_MAP_TYPE
79 #undef BPF_LINK_TYPE
80 };
81
82 /*
83 * If we're handed a bigger struct than we know of, ensure all the unknown bits
84 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
85 * we don't know about yet.
86 *
87 * There is a ToCToU between this function call and the following
88 * copy_from_user() call. However, this is not a concern since this function is
89 * meant to be a future-proofing of bits.
90 */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)91 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
92 size_t expected_size,
93 size_t actual_size)
94 {
95 int res;
96
97 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
98 return -E2BIG;
99
100 if (actual_size <= expected_size)
101 return 0;
102
103 if (uaddr.is_kernel)
104 res = memchr_inv(uaddr.kernel + expected_size, 0,
105 actual_size - expected_size) == NULL;
106 else
107 res = check_zeroed_user(uaddr.user + expected_size,
108 actual_size - expected_size);
109 if (res < 0)
110 return res;
111 return res ? 0 : -E2BIG;
112 }
113
114 const struct bpf_map_ops bpf_map_offload_ops = {
115 .map_meta_equal = bpf_map_meta_equal,
116 .map_alloc = bpf_map_offload_map_alloc,
117 .map_free = bpf_map_offload_map_free,
118 .map_check_btf = map_check_no_btf,
119 .map_mem_usage = bpf_map_offload_map_mem_usage,
120 };
121
bpf_map_write_active_inc(struct bpf_map * map)122 static void bpf_map_write_active_inc(struct bpf_map *map)
123 {
124 atomic64_inc(&map->writecnt);
125 }
126
bpf_map_write_active_dec(struct bpf_map * map)127 static void bpf_map_write_active_dec(struct bpf_map *map)
128 {
129 atomic64_dec(&map->writecnt);
130 }
131
bpf_map_write_active(const struct bpf_map * map)132 bool bpf_map_write_active(const struct bpf_map *map)
133 {
134 return atomic64_read(&map->writecnt) != 0;
135 }
136
bpf_map_value_size(const struct bpf_map * map,u64 flags)137 static u32 bpf_map_value_size(const struct bpf_map *map, u64 flags)
138 {
139 if (flags & (BPF_F_CPU | BPF_F_ALL_CPUS))
140 return map->value_size;
141 else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
142 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
143 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
144 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
145 return round_up(map->value_size, 8) * num_possible_cpus();
146 else if (IS_FD_MAP(map))
147 return sizeof(u32);
148 else
149 return map->value_size;
150 }
151
maybe_wait_bpf_programs(struct bpf_map * map)152 static void maybe_wait_bpf_programs(struct bpf_map *map)
153 {
154 /* Wait for any running non-sleepable BPF programs to complete so that
155 * userspace, when we return to it, knows that all non-sleepable
156 * programs that could be running use the new map value. For sleepable
157 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
158 * for the completions of these programs, but considering the waiting
159 * time can be very long and userspace may think it will hang forever,
160 * so don't handle sleepable BPF programs now.
161 */
162 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
163 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
164 synchronize_rcu_expedited();
165 }
166
unpin_uptr_kaddr(void * kaddr)167 static void unpin_uptr_kaddr(void *kaddr)
168 {
169 if (kaddr)
170 unpin_user_page(virt_to_page(kaddr));
171 }
172
__bpf_obj_unpin_uptrs(struct btf_record * rec,u32 cnt,void * obj)173 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj)
174 {
175 const struct btf_field *field;
176 void **uptr_addr;
177 int i;
178
179 for (i = 0, field = rec->fields; i < cnt; i++, field++) {
180 if (field->type != BPF_UPTR)
181 continue;
182
183 uptr_addr = obj + field->offset;
184 unpin_uptr_kaddr(*uptr_addr);
185 }
186 }
187
bpf_obj_unpin_uptrs(struct btf_record * rec,void * obj)188 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj)
189 {
190 if (!btf_record_has_field(rec, BPF_UPTR))
191 return;
192
193 __bpf_obj_unpin_uptrs(rec, rec->cnt, obj);
194 }
195
bpf_obj_pin_uptrs(struct btf_record * rec,void * obj)196 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj)
197 {
198 const struct btf_field *field;
199 const struct btf_type *t;
200 unsigned long start, end;
201 struct page *page;
202 void **uptr_addr;
203 int i, err;
204
205 if (!btf_record_has_field(rec, BPF_UPTR))
206 return 0;
207
208 for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) {
209 if (field->type != BPF_UPTR)
210 continue;
211
212 uptr_addr = obj + field->offset;
213 start = *(unsigned long *)uptr_addr;
214 if (!start)
215 continue;
216
217 t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id);
218 /* t->size was checked for zero before */
219 if (check_add_overflow(start, t->size - 1, &end)) {
220 err = -EFAULT;
221 goto unpin_all;
222 }
223
224 /* The uptr's struct cannot span across two pages */
225 if ((start & PAGE_MASK) != (end & PAGE_MASK)) {
226 err = -EOPNOTSUPP;
227 goto unpin_all;
228 }
229
230 err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page);
231 if (err != 1)
232 goto unpin_all;
233
234 if (PageHighMem(page)) {
235 err = -EOPNOTSUPP;
236 unpin_user_page(page);
237 goto unpin_all;
238 }
239
240 *uptr_addr = page_address(page) + offset_in_page(start);
241 }
242
243 return 0;
244
245 unpin_all:
246 __bpf_obj_unpin_uptrs(rec, i, obj);
247 return err;
248 }
249
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)250 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
251 void *key, void *value, __u64 flags)
252 {
253 int err;
254
255 /* Need to create a kthread, thus must support schedule */
256 if (bpf_map_is_offloaded(map)) {
257 return bpf_map_offload_update_elem(map, key, value, flags);
258 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
259 map->map_type == BPF_MAP_TYPE_ARENA ||
260 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
261 return map->ops->map_update_elem(map, key, value, flags);
262 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
263 map->map_type == BPF_MAP_TYPE_SOCKMAP) {
264 return sock_map_update_elem_sys(map, key, value, flags);
265 } else if (IS_FD_PROG_ARRAY(map)) {
266 return bpf_fd_array_map_update_elem(map, map_file, key, value,
267 flags);
268 }
269
270 bpf_disable_instrumentation();
271 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
272 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
273 err = bpf_percpu_hash_update(map, key, value, flags);
274 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
275 err = bpf_percpu_array_update(map, key, value, flags);
276 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
277 err = bpf_percpu_cgroup_storage_update(map, key, value,
278 flags);
279 } else if (IS_FD_ARRAY(map)) {
280 err = bpf_fd_array_map_update_elem(map, map_file, key, value,
281 flags);
282 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
283 err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
284 flags);
285 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
286 /* rcu_read_lock() is not needed */
287 err = bpf_fd_reuseport_array_update_elem(map, key, value,
288 flags);
289 } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
290 map->map_type == BPF_MAP_TYPE_STACK ||
291 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
292 err = map->ops->map_push_elem(map, value, flags);
293 } else {
294 err = bpf_obj_pin_uptrs(map->record, value);
295 if (!err) {
296 rcu_read_lock();
297 err = map->ops->map_update_elem(map, key, value, flags);
298 rcu_read_unlock();
299 if (err)
300 bpf_obj_unpin_uptrs(map->record, value);
301 }
302 }
303 bpf_enable_instrumentation();
304
305 return err;
306 }
307
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)308 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
309 __u64 flags)
310 {
311 void *ptr;
312 int err;
313
314 if (bpf_map_is_offloaded(map))
315 return bpf_map_offload_lookup_elem(map, key, value);
316
317 bpf_disable_instrumentation();
318 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
319 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
320 err = bpf_percpu_hash_copy(map, key, value, flags);
321 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
322 err = bpf_percpu_array_copy(map, key, value, flags);
323 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
324 err = bpf_percpu_cgroup_storage_copy(map, key, value, flags);
325 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
326 err = bpf_stackmap_extract(map, key, value, false);
327 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
328 err = bpf_fd_array_map_lookup_elem(map, key, value);
329 } else if (IS_FD_HASH(map)) {
330 err = bpf_fd_htab_map_lookup_elem(map, key, value);
331 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
332 err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
333 } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
334 map->map_type == BPF_MAP_TYPE_STACK ||
335 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
336 err = map->ops->map_peek_elem(map, value);
337 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
338 /* struct_ops map requires directly updating "value" */
339 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
340 } else {
341 rcu_read_lock();
342 if (map->ops->map_lookup_elem_sys_only)
343 ptr = map->ops->map_lookup_elem_sys_only(map, key);
344 else
345 ptr = map->ops->map_lookup_elem(map, key);
346 if (IS_ERR(ptr)) {
347 err = PTR_ERR(ptr);
348 } else if (!ptr) {
349 err = -ENOENT;
350 } else {
351 err = 0;
352 if (flags & BPF_F_LOCK)
353 /* lock 'ptr' and copy everything but lock */
354 copy_map_value_locked(map, value, ptr, true);
355 else
356 copy_map_value(map, value, ptr);
357 /* mask lock and timer, since value wasn't zero inited */
358 check_and_init_map_value(map, value);
359 }
360 rcu_read_unlock();
361 }
362
363 bpf_enable_instrumentation();
364
365 return err;
366 }
367
368 /* Please, do not use this function outside from the map creation path
369 * (e.g. in map update path) without taking care of setting the active
370 * memory cgroup (see at bpf_map_kmalloc_node() for example).
371 */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)372 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
373 {
374 /* We really just want to fail instead of triggering OOM killer
375 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
376 * which is used for lower order allocation requests.
377 *
378 * It has been observed that higher order allocation requests done by
379 * vmalloc with __GFP_NORETRY being set might fail due to not trying
380 * to reclaim memory from the page cache, thus we set
381 * __GFP_RETRY_MAYFAIL to avoid such situations.
382 */
383
384 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
385 unsigned int flags = 0;
386 unsigned long align = 1;
387 void *area;
388
389 if (size >= SIZE_MAX)
390 return NULL;
391
392 /* kmalloc()'ed memory can't be mmap()'ed */
393 if (mmapable) {
394 BUG_ON(!PAGE_ALIGNED(size));
395 align = SHMLBA;
396 flags = VM_USERMAP;
397 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
398 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
399 numa_node);
400 if (area != NULL)
401 return area;
402 }
403
404 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
405 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
406 flags, numa_node, __builtin_return_address(0));
407 }
408
bpf_map_area_alloc(u64 size,int numa_node)409 void *bpf_map_area_alloc(u64 size, int numa_node)
410 {
411 return __bpf_map_area_alloc(size, numa_node, false);
412 }
413
bpf_map_area_mmapable_alloc(u64 size,int numa_node)414 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
415 {
416 return __bpf_map_area_alloc(size, numa_node, true);
417 }
418
bpf_map_area_free(void * area)419 void bpf_map_area_free(void *area)
420 {
421 kvfree(area);
422 }
423
bpf_map_flags_retain_permanent(u32 flags)424 static u32 bpf_map_flags_retain_permanent(u32 flags)
425 {
426 /* Some map creation flags are not tied to the map object but
427 * rather to the map fd instead, so they have no meaning upon
428 * map object inspection since multiple file descriptors with
429 * different (access) properties can exist here. Thus, given
430 * this has zero meaning for the map itself, lets clear these
431 * from here.
432 */
433 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
434 }
435
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)436 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
437 {
438 map->map_type = attr->map_type;
439 map->key_size = attr->key_size;
440 map->value_size = attr->value_size;
441 map->max_entries = attr->max_entries;
442 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
443 map->numa_node = bpf_map_attr_numa_node(attr);
444 map->map_extra = attr->map_extra;
445 }
446
bpf_map_alloc_id(struct bpf_map * map)447 static int bpf_map_alloc_id(struct bpf_map *map)
448 {
449 int id;
450
451 idr_preload(GFP_KERNEL);
452 spin_lock_bh(&map_idr_lock);
453 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
454 if (id > 0)
455 map->id = id;
456 spin_unlock_bh(&map_idr_lock);
457 idr_preload_end();
458
459 if (WARN_ON_ONCE(!id))
460 return -ENOSPC;
461
462 return id > 0 ? 0 : id;
463 }
464
bpf_map_free_id(struct bpf_map * map)465 void bpf_map_free_id(struct bpf_map *map)
466 {
467 unsigned long flags;
468
469 /* Offloaded maps are removed from the IDR store when their device
470 * disappears - even if someone holds an fd to them they are unusable,
471 * the memory is gone, all ops will fail; they are simply waiting for
472 * refcnt to drop to be freed.
473 */
474 if (!map->id)
475 return;
476
477 spin_lock_irqsave(&map_idr_lock, flags);
478
479 idr_remove(&map_idr, map->id);
480 map->id = 0;
481
482 spin_unlock_irqrestore(&map_idr_lock, flags);
483 }
484
485 #ifdef CONFIG_MEMCG
bpf_map_save_memcg(struct bpf_map * map)486 static void bpf_map_save_memcg(struct bpf_map *map)
487 {
488 /* Currently if a map is created by a process belonging to the root
489 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
490 * So we have to check map->objcg for being NULL each time it's
491 * being used.
492 */
493 if (memcg_bpf_enabled())
494 map->objcg = get_obj_cgroup_from_current();
495 }
496
bpf_map_release_memcg(struct bpf_map * map)497 static void bpf_map_release_memcg(struct bpf_map *map)
498 {
499 if (map->objcg)
500 obj_cgroup_put(map->objcg);
501 }
502
bpf_map_get_memcg(const struct bpf_map * map)503 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
504 {
505 if (map->objcg)
506 return get_mem_cgroup_from_objcg(map->objcg);
507
508 return root_mem_cgroup;
509 }
510
bpf_map_memcg_enter(const struct bpf_map * map,struct mem_cgroup ** old_memcg,struct mem_cgroup ** new_memcg)511 void bpf_map_memcg_enter(const struct bpf_map *map, struct mem_cgroup **old_memcg,
512 struct mem_cgroup **new_memcg)
513 {
514 *new_memcg = bpf_map_get_memcg(map);
515 *old_memcg = set_active_memcg(*new_memcg);
516 }
517
bpf_map_memcg_exit(struct mem_cgroup * old_memcg,struct mem_cgroup * new_memcg)518 void bpf_map_memcg_exit(struct mem_cgroup *old_memcg,
519 struct mem_cgroup *new_memcg)
520 {
521 set_active_memcg(old_memcg);
522 mem_cgroup_put(new_memcg);
523 }
524
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)525 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
526 int node)
527 {
528 struct mem_cgroup *memcg, *old_memcg;
529 void *ptr;
530
531 bpf_map_memcg_enter(map, &old_memcg, &memcg);
532 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
533 bpf_map_memcg_exit(old_memcg, memcg);
534
535 return ptr;
536 }
537
bpf_map_kmalloc_nolock(const struct bpf_map * map,size_t size,gfp_t flags,int node)538 void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags,
539 int node)
540 {
541 struct mem_cgroup *memcg, *old_memcg;
542 void *ptr;
543
544 bpf_map_memcg_enter(map, &old_memcg, &memcg);
545 ptr = kmalloc_nolock(size, flags | __GFP_ACCOUNT, node);
546 bpf_map_memcg_exit(old_memcg, memcg);
547
548 return ptr;
549 }
550
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)551 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
552 {
553 struct mem_cgroup *memcg, *old_memcg;
554 void *ptr;
555
556 bpf_map_memcg_enter(map, &old_memcg, &memcg);
557 ptr = kzalloc(size, flags | __GFP_ACCOUNT);
558 bpf_map_memcg_exit(old_memcg, memcg);
559
560 return ptr;
561 }
562
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)563 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
564 gfp_t flags)
565 {
566 struct mem_cgroup *memcg, *old_memcg;
567 void *ptr;
568
569 bpf_map_memcg_enter(map, &old_memcg, &memcg);
570 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
571 bpf_map_memcg_exit(old_memcg, memcg);
572
573 return ptr;
574 }
575
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)576 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
577 size_t align, gfp_t flags)
578 {
579 struct mem_cgroup *memcg, *old_memcg;
580 void __percpu *ptr;
581
582 bpf_map_memcg_enter(map, &old_memcg, &memcg);
583 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
584 bpf_map_memcg_exit(old_memcg, memcg);
585
586 return ptr;
587 }
588
589 #else
bpf_map_save_memcg(struct bpf_map * map)590 static void bpf_map_save_memcg(struct bpf_map *map)
591 {
592 }
593
bpf_map_release_memcg(struct bpf_map * map)594 static void bpf_map_release_memcg(struct bpf_map *map)
595 {
596 }
597 #endif
598
can_alloc_pages(void)599 static bool can_alloc_pages(void)
600 {
601 return preempt_count() == 0 && !irqs_disabled() &&
602 !IS_ENABLED(CONFIG_PREEMPT_RT);
603 }
604
__bpf_alloc_page(int nid)605 static struct page *__bpf_alloc_page(int nid)
606 {
607 if (!can_alloc_pages())
608 return alloc_pages_nolock(__GFP_ACCOUNT, nid, 0);
609
610 return alloc_pages_node(nid,
611 GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
612 | __GFP_NOWARN,
613 0);
614 }
615
bpf_map_alloc_pages(const struct bpf_map * map,int nid,unsigned long nr_pages,struct page ** pages)616 int bpf_map_alloc_pages(const struct bpf_map *map, int nid,
617 unsigned long nr_pages, struct page **pages)
618 {
619 unsigned long i, j;
620 struct page *pg;
621 int ret = 0;
622
623 for (i = 0; i < nr_pages; i++) {
624 pg = __bpf_alloc_page(nid);
625
626 if (pg) {
627 pages[i] = pg;
628 continue;
629 }
630 for (j = 0; j < i; j++)
631 free_pages_nolock(pages[j], 0);
632 ret = -ENOMEM;
633 break;
634 }
635
636 return ret;
637 }
638
btf_field_cmp(const void * a,const void * b)639 static int btf_field_cmp(const void *a, const void *b)
640 {
641 const struct btf_field *f1 = a, *f2 = b;
642
643 if (f1->offset < f2->offset)
644 return -1;
645 else if (f1->offset > f2->offset)
646 return 1;
647 return 0;
648 }
649
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)650 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
651 u32 field_mask)
652 {
653 struct btf_field *field;
654
655 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
656 return NULL;
657 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
658 if (!field || !(field->type & field_mask))
659 return NULL;
660 return field;
661 }
662
btf_record_free(struct btf_record * rec)663 void btf_record_free(struct btf_record *rec)
664 {
665 int i;
666
667 if (IS_ERR_OR_NULL(rec))
668 return;
669 for (i = 0; i < rec->cnt; i++) {
670 switch (rec->fields[i].type) {
671 case BPF_KPTR_UNREF:
672 case BPF_KPTR_REF:
673 case BPF_KPTR_PERCPU:
674 case BPF_UPTR:
675 if (rec->fields[i].kptr.module)
676 module_put(rec->fields[i].kptr.module);
677 if (btf_is_kernel(rec->fields[i].kptr.btf))
678 btf_put(rec->fields[i].kptr.btf);
679 break;
680 case BPF_LIST_HEAD:
681 case BPF_LIST_NODE:
682 case BPF_RB_ROOT:
683 case BPF_RB_NODE:
684 case BPF_SPIN_LOCK:
685 case BPF_RES_SPIN_LOCK:
686 case BPF_TIMER:
687 case BPF_REFCOUNT:
688 case BPF_WORKQUEUE:
689 case BPF_TASK_WORK:
690 /* Nothing to release */
691 break;
692 default:
693 WARN_ON_ONCE(1);
694 continue;
695 }
696 }
697 kfree(rec);
698 }
699
bpf_map_free_record(struct bpf_map * map)700 void bpf_map_free_record(struct bpf_map *map)
701 {
702 btf_record_free(map->record);
703 map->record = NULL;
704 }
705
btf_record_dup(const struct btf_record * rec)706 struct btf_record *btf_record_dup(const struct btf_record *rec)
707 {
708 const struct btf_field *fields;
709 struct btf_record *new_rec;
710 int ret, size, i;
711
712 if (IS_ERR_OR_NULL(rec))
713 return NULL;
714 size = struct_size(rec, fields, rec->cnt);
715 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
716 if (!new_rec)
717 return ERR_PTR(-ENOMEM);
718 /* Do a deep copy of the btf_record */
719 fields = rec->fields;
720 new_rec->cnt = 0;
721 for (i = 0; i < rec->cnt; i++) {
722 switch (fields[i].type) {
723 case BPF_KPTR_UNREF:
724 case BPF_KPTR_REF:
725 case BPF_KPTR_PERCPU:
726 case BPF_UPTR:
727 if (btf_is_kernel(fields[i].kptr.btf))
728 btf_get(fields[i].kptr.btf);
729 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
730 ret = -ENXIO;
731 goto free;
732 }
733 break;
734 case BPF_LIST_HEAD:
735 case BPF_LIST_NODE:
736 case BPF_RB_ROOT:
737 case BPF_RB_NODE:
738 case BPF_SPIN_LOCK:
739 case BPF_RES_SPIN_LOCK:
740 case BPF_TIMER:
741 case BPF_REFCOUNT:
742 case BPF_WORKQUEUE:
743 case BPF_TASK_WORK:
744 /* Nothing to acquire */
745 break;
746 default:
747 ret = -EFAULT;
748 WARN_ON_ONCE(1);
749 goto free;
750 }
751 new_rec->cnt++;
752 }
753 return new_rec;
754 free:
755 btf_record_free(new_rec);
756 return ERR_PTR(ret);
757 }
758
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)759 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
760 {
761 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
762 int size;
763
764 if (!a_has_fields && !b_has_fields)
765 return true;
766 if (a_has_fields != b_has_fields)
767 return false;
768 if (rec_a->cnt != rec_b->cnt)
769 return false;
770 size = struct_size(rec_a, fields, rec_a->cnt);
771 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
772 * members are zeroed out. So memcmp is safe to do without worrying
773 * about padding/unused fields.
774 *
775 * While spin_lock, timer, and kptr have no relation to map BTF,
776 * list_head metadata is specific to map BTF, the btf and value_rec
777 * members in particular. btf is the map BTF, while value_rec points to
778 * btf_record in that map BTF.
779 *
780 * So while by default, we don't rely on the map BTF (which the records
781 * were parsed from) matching for both records, which is not backwards
782 * compatible, in case list_head is part of it, we implicitly rely on
783 * that by way of depending on memcmp succeeding for it.
784 */
785 return !memcmp(rec_a, rec_b, size);
786 }
787
bpf_obj_free_timer(const struct btf_record * rec,void * obj)788 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
789 {
790 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
791 return;
792 bpf_timer_cancel_and_free(obj + rec->timer_off);
793 }
794
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)795 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
796 {
797 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
798 return;
799 bpf_wq_cancel_and_free(obj + rec->wq_off);
800 }
801
bpf_obj_free_task_work(const struct btf_record * rec,void * obj)802 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj)
803 {
804 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK)))
805 return;
806 bpf_task_work_cancel_and_free(obj + rec->task_work_off);
807 }
808
bpf_obj_cancel_fields(struct bpf_map * map,void * obj)809 void bpf_obj_cancel_fields(struct bpf_map *map, void *obj)
810 {
811 bpf_map_free_internal_structs(map, obj);
812 }
813
bpf_obj_free_fields(const struct btf_record * rec,void * obj)814 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
815 {
816 const struct btf_field *fields;
817 int i;
818
819 if (IS_ERR_OR_NULL(rec))
820 return;
821 fields = rec->fields;
822 for (i = 0; i < rec->cnt; i++) {
823 struct btf_struct_meta *pointee_struct_meta;
824 const struct btf_field *field = &fields[i];
825 void *field_ptr = obj + field->offset;
826 void *xchgd_field;
827
828 switch (fields[i].type) {
829 case BPF_SPIN_LOCK:
830 case BPF_RES_SPIN_LOCK:
831 break;
832 case BPF_TIMER:
833 bpf_timer_cancel_and_free(field_ptr);
834 break;
835 case BPF_WORKQUEUE:
836 bpf_wq_cancel_and_free(field_ptr);
837 break;
838 case BPF_TASK_WORK:
839 bpf_task_work_cancel_and_free(field_ptr);
840 break;
841 case BPF_KPTR_UNREF:
842 WRITE_ONCE(*(u64 *)field_ptr, 0);
843 break;
844 case BPF_KPTR_REF:
845 case BPF_KPTR_PERCPU:
846 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
847 if (!xchgd_field)
848 break;
849
850 if (!btf_is_kernel(field->kptr.btf)) {
851 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
852 field->kptr.btf_id);
853 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
854 pointee_struct_meta->record : NULL,
855 fields[i].type == BPF_KPTR_PERCPU);
856 } else {
857 field->kptr.dtor(xchgd_field);
858 }
859 break;
860 case BPF_UPTR:
861 /* The caller ensured that no one is using the uptr */
862 unpin_uptr_kaddr(*(void **)field_ptr);
863 break;
864 case BPF_LIST_HEAD:
865 if (WARN_ON_ONCE(rec->spin_lock_off < 0))
866 continue;
867 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
868 break;
869 case BPF_RB_ROOT:
870 if (WARN_ON_ONCE(rec->spin_lock_off < 0))
871 continue;
872 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
873 break;
874 case BPF_LIST_NODE:
875 case BPF_RB_NODE:
876 case BPF_REFCOUNT:
877 break;
878 default:
879 WARN_ON_ONCE(1);
880 continue;
881 }
882 }
883 }
884
bpf_map_free(struct bpf_map * map)885 static void bpf_map_free(struct bpf_map *map)
886 {
887 struct btf_record *rec = map->record;
888 struct btf *btf = map->btf;
889
890 /* implementation dependent freeing. Disabling migration to simplify
891 * the free of values or special fields allocated from bpf memory
892 * allocator.
893 */
894 kfree(map->excl_prog_sha);
895 migrate_disable();
896 map->ops->map_free(map);
897 migrate_enable();
898
899 /* Delay freeing of btf_record for maps, as map_free
900 * callback usually needs access to them. It is better to do it here
901 * than require each callback to do the free itself manually.
902 *
903 * Note that the btf_record stashed in map->inner_map_meta->record was
904 * already freed using the map_free callback for map in map case which
905 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
906 * template bpf_map struct used during verification.
907 */
908 btf_record_free(rec);
909 /* Delay freeing of btf for maps, as map_free callback may need
910 * struct_meta info which will be freed with btf_put().
911 */
912 btf_put(btf);
913 }
914
915 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)916 static void bpf_map_free_deferred(struct work_struct *work)
917 {
918 struct bpf_map *map = container_of(work, struct bpf_map, work);
919
920 security_bpf_map_free(map);
921 bpf_map_release_memcg(map);
922 bpf_map_owner_free(map);
923 bpf_map_free(map);
924 }
925
bpf_map_put_uref(struct bpf_map * map)926 static void bpf_map_put_uref(struct bpf_map *map)
927 {
928 if (atomic64_dec_and_test(&map->usercnt)) {
929 if (map->ops->map_release_uref)
930 map->ops->map_release_uref(map);
931 }
932 }
933
bpf_map_free_in_work(struct bpf_map * map)934 static void bpf_map_free_in_work(struct bpf_map *map)
935 {
936 INIT_WORK(&map->work, bpf_map_free_deferred);
937 /* Avoid spawning kworkers, since they all might contend
938 * for the same mutex like slab_mutex.
939 */
940 queue_work(system_dfl_wq, &map->work);
941 }
942
bpf_map_free_rcu_gp(struct rcu_head * rcu)943 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
944 {
945 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
946 }
947
948 /* decrement map refcnt and schedule it for freeing via workqueue
949 * (underlying map implementation ops->map_free() might sleep)
950 */
bpf_map_put(struct bpf_map * map)951 void bpf_map_put(struct bpf_map *map)
952 {
953 if (atomic64_dec_and_test(&map->refcnt)) {
954 /* bpf_map_free_id() must be called first */
955 bpf_map_free_id(map);
956
957 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
958 /* RCU tasks trace grace period implies RCU grace period. */
959 if (READ_ONCE(map->free_after_mult_rcu_gp))
960 call_rcu_tasks_trace(&map->rcu, bpf_map_free_rcu_gp);
961 else if (READ_ONCE(map->free_after_rcu_gp))
962 call_rcu(&map->rcu, bpf_map_free_rcu_gp);
963 else
964 bpf_map_free_in_work(map);
965 }
966 }
967 EXPORT_SYMBOL_GPL(bpf_map_put);
968
bpf_map_put_with_uref(struct bpf_map * map)969 void bpf_map_put_with_uref(struct bpf_map *map)
970 {
971 bpf_map_put_uref(map);
972 bpf_map_put(map);
973 }
974
bpf_map_release(struct inode * inode,struct file * filp)975 static int bpf_map_release(struct inode *inode, struct file *filp)
976 {
977 struct bpf_map *map = filp->private_data;
978
979 if (map->ops->map_release)
980 map->ops->map_release(map, filp);
981
982 bpf_map_put_with_uref(map);
983 return 0;
984 }
985
map_get_sys_perms(struct bpf_map * map,struct fd f)986 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
987 {
988 fmode_t mode = fd_file(f)->f_mode;
989
990 /* Our file permissions may have been overridden by global
991 * map permissions facing syscall side.
992 */
993 if (READ_ONCE(map->frozen))
994 mode &= ~FMODE_CAN_WRITE;
995 return mode;
996 }
997
998 #ifdef CONFIG_PROC_FS
999 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)1000 static u64 bpf_map_memory_usage(const struct bpf_map *map)
1001 {
1002 return map->ops->map_mem_usage(map);
1003 }
1004
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)1005 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
1006 {
1007 struct bpf_map *map = filp->private_data;
1008 u32 type = 0, jited = 0;
1009
1010 spin_lock(&map->owner_lock);
1011 if (map->owner) {
1012 type = map->owner->type;
1013 jited = map->owner->jited;
1014 }
1015 spin_unlock(&map->owner_lock);
1016
1017 seq_printf(m,
1018 "map_type:\t%u\n"
1019 "key_size:\t%u\n"
1020 "value_size:\t%u\n"
1021 "max_entries:\t%u\n"
1022 "map_flags:\t%#x\n"
1023 "map_extra:\t%#llx\n"
1024 "memlock:\t%llu\n"
1025 "map_id:\t%u\n"
1026 "frozen:\t%u\n",
1027 map->map_type,
1028 map->key_size,
1029 map->value_size,
1030 map->max_entries,
1031 map->map_flags,
1032 (unsigned long long)map->map_extra,
1033 bpf_map_memory_usage(map),
1034 map->id,
1035 READ_ONCE(map->frozen));
1036 if (type) {
1037 seq_printf(m, "owner_prog_type:\t%u\n", type);
1038 seq_printf(m, "owner_jited:\t%u\n", jited);
1039 }
1040 }
1041 #endif
1042
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)1043 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
1044 loff_t *ppos)
1045 {
1046 /* We need this handler such that alloc_file() enables
1047 * f_mode with FMODE_CAN_READ.
1048 */
1049 return -EINVAL;
1050 }
1051
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1052 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1053 size_t siz, loff_t *ppos)
1054 {
1055 /* We need this handler such that alloc_file() enables
1056 * f_mode with FMODE_CAN_WRITE.
1057 */
1058 return -EINVAL;
1059 }
1060
1061 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1062 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1063 {
1064 struct bpf_map *map = vma->vm_file->private_data;
1065
1066 if (vma->vm_flags & VM_MAYWRITE)
1067 bpf_map_write_active_inc(map);
1068 }
1069
1070 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1071 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1072 {
1073 struct bpf_map *map = vma->vm_file->private_data;
1074
1075 if (vma->vm_flags & VM_MAYWRITE)
1076 bpf_map_write_active_dec(map);
1077 }
1078
bpf_map_mmap_fault(struct vm_fault * vmf)1079 static vm_fault_t bpf_map_mmap_fault(struct vm_fault *vmf)
1080 {
1081 struct bpf_map *map = vmf->vma->vm_private_data;
1082
1083 return map->ops->map_mmap_fault(map, vmf);
1084 }
1085
1086 static const struct vm_operations_struct bpf_map_default_vmops = {
1087 .open = bpf_map_mmap_open,
1088 .close = bpf_map_mmap_close,
1089 };
1090
1091 static const struct vm_operations_struct bpf_map_lazy_vmops = {
1092 .open = bpf_map_mmap_open,
1093 .close = bpf_map_mmap_close,
1094 .fault = bpf_map_mmap_fault,
1095 };
1096
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1097 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1098 {
1099 struct bpf_map *map = filp->private_data;
1100 int err = 0;
1101
1102 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1103 return -ENOTSUPP;
1104
1105 if (!(vma->vm_flags & VM_SHARED))
1106 return -EINVAL;
1107
1108 mutex_lock(&map->freeze_mutex);
1109
1110 if (vma->vm_flags & VM_WRITE) {
1111 if (map->frozen) {
1112 err = -EPERM;
1113 goto out;
1114 }
1115 /* map is meant to be read-only, so do not allow mapping as
1116 * writable, because it's possible to leak a writable page
1117 * reference and allows user-space to still modify it after
1118 * freezing, while verifier will assume contents do not change
1119 */
1120 if (map->map_flags & BPF_F_RDONLY_PROG) {
1121 err = -EACCES;
1122 goto out;
1123 }
1124 bpf_map_write_active_inc(map);
1125 }
1126 out:
1127 mutex_unlock(&map->freeze_mutex);
1128 if (err)
1129 return err;
1130
1131 /* set default open/close callbacks */
1132 vma->vm_ops = map->ops->map_mmap_fault ? &bpf_map_lazy_vmops : &bpf_map_default_vmops;
1133 vma->vm_private_data = map;
1134 vm_flags_clear(vma, VM_MAYEXEC);
1135 /* If mapping is read-only, then disallow potentially re-mapping with
1136 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1137 * means that as far as BPF map's memory-mapped VMAs are concerned,
1138 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1139 * both should be set, so we can forget about VM_MAYWRITE and always
1140 * check just VM_WRITE
1141 */
1142 if (!(vma->vm_flags & VM_WRITE))
1143 vm_flags_clear(vma, VM_MAYWRITE);
1144
1145 err = map->ops->map_mmap(map, vma);
1146 if (err) {
1147 if (vma->vm_flags & VM_WRITE)
1148 bpf_map_write_active_dec(map);
1149 }
1150
1151 return err;
1152 }
1153
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1154 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1155 {
1156 struct bpf_map *map = filp->private_data;
1157
1158 if (map->ops->map_poll)
1159 return map->ops->map_poll(map, filp, pts);
1160
1161 return EPOLLERR;
1162 }
1163
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1164 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1165 unsigned long len, unsigned long pgoff,
1166 unsigned long flags)
1167 {
1168 struct bpf_map *map = filp->private_data;
1169
1170 if (map->ops->map_get_unmapped_area)
1171 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1172 #ifdef CONFIG_MMU
1173 return mm_get_unmapped_area(filp, addr, len, pgoff, flags);
1174 #else
1175 return addr;
1176 #endif
1177 }
1178
1179 const struct file_operations bpf_map_fops = {
1180 #ifdef CONFIG_PROC_FS
1181 .show_fdinfo = bpf_map_show_fdinfo,
1182 #endif
1183 .release = bpf_map_release,
1184 .read = bpf_dummy_read,
1185 .write = bpf_dummy_write,
1186 .mmap = bpf_map_mmap,
1187 .poll = bpf_map_poll,
1188 .get_unmapped_area = bpf_get_unmapped_area,
1189 };
1190
bpf_map_new_fd(struct bpf_map * map,int flags)1191 int bpf_map_new_fd(struct bpf_map *map, int flags)
1192 {
1193 int ret;
1194
1195 ret = security_bpf_map(map, OPEN_FMODE(flags));
1196 if (ret < 0)
1197 return ret;
1198
1199 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1200 flags | O_CLOEXEC);
1201 }
1202
bpf_get_file_flag(int flags)1203 int bpf_get_file_flag(int flags)
1204 {
1205 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1206 return -EINVAL;
1207 if (flags & BPF_F_RDONLY)
1208 return O_RDONLY;
1209 if (flags & BPF_F_WRONLY)
1210 return O_WRONLY;
1211 return O_RDWR;
1212 }
1213
1214 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1215 #define CHECK_ATTR(CMD) \
1216 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1217 sizeof(attr->CMD##_LAST_FIELD), 0, \
1218 sizeof(*attr) - \
1219 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1220 sizeof(attr->CMD##_LAST_FIELD)) != NULL
1221
1222 /* dst and src must have at least "size" number of bytes.
1223 * Return strlen on success and < 0 on error.
1224 */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1225 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1226 {
1227 const char *end = src + size;
1228 const char *orig_src = src;
1229
1230 memset(dst, 0, size);
1231 /* Copy all isalnum(), '_' and '.' chars. */
1232 while (src < end && *src) {
1233 if (!isalnum(*src) &&
1234 *src != '_' && *src != '.')
1235 return -EINVAL;
1236 *dst++ = *src++;
1237 }
1238
1239 /* No '\0' found in "size" number of bytes */
1240 if (src == end)
1241 return -EINVAL;
1242
1243 return src - orig_src;
1244 }
1245 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy);
1246
map_check_no_btf(struct bpf_map * map,const struct btf * btf,const struct btf_type * key_type,const struct btf_type * value_type)1247 int map_check_no_btf(struct bpf_map *map,
1248 const struct btf *btf,
1249 const struct btf_type *key_type,
1250 const struct btf_type *value_type)
1251 {
1252 return -ENOTSUPP;
1253 }
1254
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1255 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1256 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1257 {
1258 const struct btf_type *key_type, *value_type;
1259 u32 key_size, value_size;
1260 int ret = 0;
1261
1262 /* Some maps allow key to be unspecified. */
1263 if (btf_key_id) {
1264 key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1265 if (!key_type || key_size != map->key_size)
1266 return -EINVAL;
1267 } else {
1268 key_type = btf_type_by_id(btf, 0);
1269 if (!map->ops->map_check_btf)
1270 return -EINVAL;
1271 }
1272
1273 value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1274 if (!value_type || value_size != map->value_size)
1275 return -EINVAL;
1276
1277 map->record = btf_parse_fields(btf, value_type,
1278 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1279 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR |
1280 BPF_TASK_WORK,
1281 map->value_size);
1282 if (!IS_ERR_OR_NULL(map->record)) {
1283 int i;
1284
1285 if (!bpf_token_capable(token, CAP_BPF)) {
1286 ret = -EPERM;
1287 goto free_map_tab;
1288 }
1289 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1290 ret = -EACCES;
1291 goto free_map_tab;
1292 }
1293 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1294 switch (map->record->field_mask & (1 << i)) {
1295 case 0:
1296 continue;
1297 case BPF_SPIN_LOCK:
1298 case BPF_RES_SPIN_LOCK:
1299 if (map->map_type != BPF_MAP_TYPE_HASH &&
1300 map->map_type != BPF_MAP_TYPE_RHASH &&
1301 map->map_type != BPF_MAP_TYPE_ARRAY &&
1302 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1303 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1304 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1305 map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1306 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1307 ret = -EOPNOTSUPP;
1308 goto free_map_tab;
1309 }
1310 break;
1311 case BPF_TIMER:
1312 case BPF_WORKQUEUE:
1313 case BPF_TASK_WORK:
1314 if (map->map_type != BPF_MAP_TYPE_HASH &&
1315 map->map_type != BPF_MAP_TYPE_RHASH &&
1316 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1317 map->map_type != BPF_MAP_TYPE_ARRAY) {
1318 ret = -EOPNOTSUPP;
1319 goto free_map_tab;
1320 }
1321 break;
1322 case BPF_KPTR_UNREF:
1323 case BPF_KPTR_REF:
1324 case BPF_KPTR_PERCPU:
1325 case BPF_REFCOUNT:
1326 if (map->map_type != BPF_MAP_TYPE_HASH &&
1327 map->map_type != BPF_MAP_TYPE_RHASH &&
1328 map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1329 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1330 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1331 map->map_type != BPF_MAP_TYPE_ARRAY &&
1332 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1333 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1334 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1335 map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1336 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1337 ret = -EOPNOTSUPP;
1338 goto free_map_tab;
1339 }
1340 break;
1341 case BPF_UPTR:
1342 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1343 ret = -EOPNOTSUPP;
1344 goto free_map_tab;
1345 }
1346 break;
1347 case BPF_LIST_HEAD:
1348 case BPF_RB_ROOT:
1349 if (map->map_type != BPF_MAP_TYPE_HASH &&
1350 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1351 map->map_type != BPF_MAP_TYPE_ARRAY) {
1352 ret = -EOPNOTSUPP;
1353 goto free_map_tab;
1354 }
1355 break;
1356 default:
1357 /* Fail if map_type checks are missing for a field type */
1358 ret = -EOPNOTSUPP;
1359 goto free_map_tab;
1360 }
1361 }
1362 }
1363
1364 ret = btf_check_and_fixup_fields(btf, map->record);
1365 if (ret < 0)
1366 goto free_map_tab;
1367
1368 if (map->ops->map_check_btf) {
1369 ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1370 if (ret < 0)
1371 goto free_map_tab;
1372 }
1373
1374 return ret;
1375 free_map_tab:
1376 bpf_map_free_record(map);
1377 return ret;
1378 }
1379
1380 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size
1381 /* called via syscall */
map_create_alloc(union bpf_attr * attr,bpfptr_t uattr,struct bpf_verifier_log * log,struct bpf_map ** mapp,struct bpf_token ** tokenp)1382 static int map_create_alloc(union bpf_attr *attr, bpfptr_t uattr, struct bpf_verifier_log *log,
1383 struct bpf_map **mapp, struct bpf_token **tokenp)
1384 {
1385 const struct bpf_map_ops *ops;
1386 struct bpf_token *token = NULL;
1387 int numa_node = bpf_map_attr_numa_node(attr);
1388 u32 map_type = attr->map_type;
1389 struct bpf_map *map;
1390 bool token_flag;
1391 int err;
1392
1393 err = CHECK_ATTR(BPF_MAP_CREATE);
1394 if (err) {
1395 bpf_log(log, "Invalid attr.\n");
1396 return -EINVAL;
1397 }
1398
1399 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1400 * to avoid per-map type checks tripping on unknown flag
1401 */
1402 token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1403 attr->map_flags &= ~BPF_F_TOKEN_FD;
1404
1405 if (attr->btf_vmlinux_value_type_id) {
1406 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS) {
1407 bpf_log(log, "btf_vmlinux_value_type_id can only be used with struct_ops maps.\n");
1408 return -EINVAL;
1409 }
1410 if (attr->btf_key_type_id || attr->btf_value_type_id) {
1411 bpf_log(log, "btf_vmlinux_value_type_id is mutually exclusive with btf_key_type_id and btf_value_type_id.\n");
1412 return -EINVAL;
1413 }
1414 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1415 bpf_log(log, "Invalid btf_value_type_id.\n");
1416 return -EINVAL;
1417 }
1418
1419 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1420 attr->map_type != BPF_MAP_TYPE_ARENA &&
1421 attr->map_type != BPF_MAP_TYPE_RHASH &&
1422 attr->map_extra != 0) {
1423 bpf_log(log, "Invalid map_extra.\n");
1424 return -EINVAL;
1425 }
1426
1427 if (numa_node != NUMA_NO_NODE &&
1428 ((unsigned int)numa_node >= nr_node_ids ||
1429 !node_online(numa_node))) {
1430 bpf_log(log, "Invalid numa_node.\n");
1431 return -EINVAL;
1432 }
1433
1434 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1435 map_type = attr->map_type;
1436 if (map_type >= ARRAY_SIZE(bpf_map_types)) {
1437 bpf_log(log, "Invalid map_type.\n");
1438 return -EINVAL;
1439 }
1440 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1441 ops = bpf_map_types[map_type];
1442 if (!ops)
1443 return -EINVAL;
1444
1445 if (ops->map_alloc_check) {
1446 err = ops->map_alloc_check(attr);
1447 if (err)
1448 return err;
1449 }
1450 if (attr->map_ifindex)
1451 ops = &bpf_map_offload_ops;
1452 if (!ops->map_mem_usage)
1453 return -EINVAL;
1454
1455 if (token_flag) {
1456 token = bpf_token_get_from_fd(attr->map_token_fd);
1457 if (IS_ERR(token)) {
1458 bpf_log(log, "Invalid map_token_fd.\n");
1459 return PTR_ERR(token);
1460 }
1461
1462 /* if current token doesn't grant map creation permissions,
1463 * then we can't use this token, so ignore it and rely on
1464 * system-wide capabilities checks
1465 */
1466 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1467 !bpf_token_allow_map_type(token, attr->map_type)) {
1468 bpf_token_put(token);
1469 token = NULL;
1470 }
1471 }
1472
1473 err = -EPERM;
1474
1475 /* Intent here is for unprivileged_bpf_disabled to block BPF map
1476 * creation for unprivileged users; other actions depend
1477 * on fd availability and access to bpffs, so are dependent on
1478 * object creation success. Even with unprivileged BPF disabled,
1479 * capability checks are still carried out.
1480 */
1481 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1482 goto put_token;
1483
1484 /* check privileged map type permissions */
1485 switch (map_type) {
1486 case BPF_MAP_TYPE_ARRAY:
1487 case BPF_MAP_TYPE_PERCPU_ARRAY:
1488 case BPF_MAP_TYPE_PROG_ARRAY:
1489 case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1490 case BPF_MAP_TYPE_CGROUP_ARRAY:
1491 case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1492 case BPF_MAP_TYPE_HASH:
1493 case BPF_MAP_TYPE_RHASH:
1494 case BPF_MAP_TYPE_PERCPU_HASH:
1495 case BPF_MAP_TYPE_HASH_OF_MAPS:
1496 case BPF_MAP_TYPE_RINGBUF:
1497 case BPF_MAP_TYPE_USER_RINGBUF:
1498 case BPF_MAP_TYPE_CGROUP_STORAGE:
1499 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1500 /* unprivileged */
1501 break;
1502 case BPF_MAP_TYPE_SK_STORAGE:
1503 case BPF_MAP_TYPE_INODE_STORAGE:
1504 case BPF_MAP_TYPE_TASK_STORAGE:
1505 case BPF_MAP_TYPE_CGRP_STORAGE:
1506 case BPF_MAP_TYPE_BLOOM_FILTER:
1507 case BPF_MAP_TYPE_LPM_TRIE:
1508 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1509 case BPF_MAP_TYPE_STACK_TRACE:
1510 case BPF_MAP_TYPE_QUEUE:
1511 case BPF_MAP_TYPE_STACK:
1512 case BPF_MAP_TYPE_LRU_HASH:
1513 case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1514 case BPF_MAP_TYPE_STRUCT_OPS:
1515 case BPF_MAP_TYPE_CPUMAP:
1516 case BPF_MAP_TYPE_ARENA:
1517 case BPF_MAP_TYPE_INSN_ARRAY:
1518 if (!bpf_token_capable(token, CAP_BPF))
1519 goto put_token;
1520 break;
1521 case BPF_MAP_TYPE_SOCKMAP:
1522 case BPF_MAP_TYPE_SOCKHASH:
1523 case BPF_MAP_TYPE_DEVMAP:
1524 case BPF_MAP_TYPE_DEVMAP_HASH:
1525 case BPF_MAP_TYPE_XSKMAP:
1526 if (!bpf_token_capable(token, CAP_NET_ADMIN))
1527 goto put_token;
1528 break;
1529 default:
1530 WARN(1, "unsupported map type %d", map_type);
1531 goto put_token;
1532 }
1533
1534 map = ops->map_alloc(attr);
1535 if (IS_ERR(map)) {
1536 err = PTR_ERR(map);
1537 goto put_token;
1538 }
1539 map->ops = ops;
1540 map->map_type = map_type;
1541
1542 err = bpf_obj_name_cpy(map->name, attr->map_name,
1543 sizeof(attr->map_name));
1544 if (err < 0) {
1545 bpf_log(log, "Invalid map_name.\n");
1546 goto free_map;
1547 }
1548
1549 preempt_disable();
1550 map->cookie = gen_cookie_next(&bpf_map_cookie);
1551 preempt_enable();
1552
1553 atomic64_set(&map->refcnt, 1);
1554 atomic64_set(&map->usercnt, 1);
1555 mutex_init(&map->freeze_mutex);
1556 spin_lock_init(&map->owner_lock);
1557
1558 if (attr->btf_key_type_id || attr->btf_value_type_id ||
1559 /* Even the map's value is a kernel's struct,
1560 * the bpf_prog.o must have BTF to begin with
1561 * to figure out the corresponding kernel's
1562 * counter part. Thus, attr->btf_fd has
1563 * to be valid also.
1564 */
1565 attr->btf_vmlinux_value_type_id) {
1566 struct btf *btf;
1567
1568 btf = btf_get_by_fd(attr->btf_fd);
1569 if (IS_ERR(btf)) {
1570 bpf_log(log, "Invalid btf_fd.\n");
1571 err = PTR_ERR(btf);
1572 goto free_map;
1573 }
1574 if (btf_is_kernel(btf)) {
1575 btf_put(btf);
1576 err = -EACCES;
1577 goto free_map;
1578 }
1579 map->btf = btf;
1580
1581 if (attr->btf_value_type_id) {
1582 err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1583 attr->btf_value_type_id);
1584 if (err)
1585 goto free_map;
1586 }
1587
1588 map->btf_key_type_id = attr->btf_key_type_id;
1589 map->btf_value_type_id = attr->btf_value_type_id;
1590 map->btf_vmlinux_value_type_id =
1591 attr->btf_vmlinux_value_type_id;
1592 }
1593
1594 if (attr->excl_prog_hash) {
1595 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel);
1596
1597 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) {
1598 bpf_log(log, "Invalid excl_prog_hash_size.\n");
1599 err = -EINVAL;
1600 goto free_map;
1601 }
1602
1603 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
1604 if (!map->excl_prog_sha) {
1605 err = -ENOMEM;
1606 goto free_map;
1607 }
1608
1609 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) {
1610 err = -EFAULT;
1611 goto free_map;
1612 }
1613 } else if (attr->excl_prog_hash_size) {
1614 bpf_log(log, "Invalid excl_prog_hash_size.\n");
1615 err = -EINVAL;
1616 goto free_map;
1617 }
1618
1619 *mapp = map;
1620 *tokenp = token;
1621 return 0;
1622
1623 free_map:
1624 bpf_map_free(map);
1625 put_token:
1626 bpf_token_put(token);
1627 return err;
1628 }
1629
map_create(union bpf_attr * attr,bpfptr_t uattr,struct bpf_common_attr * attr_common,bpfptr_t uattr_common,u32 size_common)1630 static int map_create(union bpf_attr *attr, bpfptr_t uattr, struct bpf_common_attr *attr_common,
1631 bpfptr_t uattr_common, u32 size_common)
1632 {
1633 struct bpf_token *token = NULL;
1634 struct bpf_verifier_log *log;
1635 struct bpf_log_attr attr_log;
1636 struct bpf_map *map = NULL;
1637 int err, ret;
1638 int f_flags;
1639
1640 log = bpf_log_attr_create_vlog(&attr_log, attr_common, uattr_common, size_common);
1641 if (IS_ERR(log))
1642 return PTR_ERR(log);
1643
1644 err = map_create_alloc(attr, uattr, log, &map, &token);
1645
1646 /* preserve original error even if log finalization is successful */
1647 ret = bpf_log_attr_finalize(&attr_log, log);
1648 if (ret)
1649 err = ret;
1650
1651 kfree(log);
1652
1653 if (err)
1654 goto free_map;
1655
1656 f_flags = bpf_get_file_flag(attr->map_flags);
1657 if (f_flags < 0) {
1658 err = f_flags;
1659 goto free_map;
1660 }
1661
1662 err = security_bpf_map_create(map, attr, token, uattr.is_kernel);
1663 if (err)
1664 goto free_map;
1665
1666 err = bpf_map_alloc_id(map);
1667 if (err)
1668 goto free_map_sec;
1669
1670 bpf_map_save_memcg(map);
1671 bpf_token_put(token);
1672
1673 err = bpf_map_new_fd(map, f_flags);
1674 if (err < 0) {
1675 /* failed to allocate fd.
1676 * bpf_map_put_with_uref() is needed because the above
1677 * bpf_map_alloc_id() has published the map
1678 * to the userspace and the userspace may
1679 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1680 */
1681 bpf_map_put_with_uref(map);
1682 return err;
1683 }
1684
1685 return err;
1686
1687 free_map_sec:
1688 security_bpf_map_free(map);
1689 free_map:
1690 if (map)
1691 bpf_map_free(map);
1692 bpf_token_put(token);
1693 return err;
1694 }
1695
bpf_map_inc(struct bpf_map * map)1696 void bpf_map_inc(struct bpf_map *map)
1697 {
1698 atomic64_inc(&map->refcnt);
1699 }
1700 EXPORT_SYMBOL_GPL(bpf_map_inc);
1701
bpf_map_inc_with_uref(struct bpf_map * map)1702 void bpf_map_inc_with_uref(struct bpf_map *map)
1703 {
1704 atomic64_inc(&map->refcnt);
1705 atomic64_inc(&map->usercnt);
1706 }
1707 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1708
bpf_map_get(u32 ufd)1709 struct bpf_map *bpf_map_get(u32 ufd)
1710 {
1711 CLASS(fd, f)(ufd);
1712 struct bpf_map *map = __bpf_map_get(f);
1713
1714 if (!IS_ERR(map))
1715 bpf_map_inc(map);
1716
1717 return map;
1718 }
1719 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL");
1720
bpf_map_get_with_uref(u32 ufd)1721 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1722 {
1723 CLASS(fd, f)(ufd);
1724 struct bpf_map *map = __bpf_map_get(f);
1725
1726 if (!IS_ERR(map))
1727 bpf_map_inc_with_uref(map);
1728
1729 return map;
1730 }
1731
1732 /* map_idr_lock should have been held or the map should have been
1733 * protected by rcu read lock.
1734 */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1735 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1736 {
1737 int refold;
1738
1739 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1740 if (!refold)
1741 return ERR_PTR(-ENOENT);
1742 if (uref)
1743 atomic64_inc(&map->usercnt);
1744
1745 return map;
1746 }
1747
bpf_map_inc_not_zero(struct bpf_map * map)1748 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1749 {
1750 lockdep_assert(rcu_read_lock_held());
1751 return __bpf_map_inc_not_zero(map, false);
1752 }
1753 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1754
bpf_stackmap_extract(struct bpf_map * map,void * key,void * value,bool delete)1755 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value,
1756 bool delete)
1757 {
1758 return -ENOTSUPP;
1759 }
1760
__bpf_copy_key(void __user * ukey,u64 key_size)1761 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1762 {
1763 if (key_size)
1764 return vmemdup_user(ukey, key_size);
1765
1766 if (ukey)
1767 return ERR_PTR(-EINVAL);
1768
1769 return NULL;
1770 }
1771
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1772 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1773 {
1774 if (key_size)
1775 return kvmemdup_bpfptr(ukey, key_size);
1776
1777 if (!bpfptr_is_null(ukey))
1778 return ERR_PTR(-EINVAL);
1779
1780 return NULL;
1781 }
1782
1783 /* last field in 'union bpf_attr' used by this command */
1784 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1785
map_lookup_elem(union bpf_attr * attr)1786 static int map_lookup_elem(union bpf_attr *attr)
1787 {
1788 void __user *ukey = u64_to_user_ptr(attr->key);
1789 void __user *uvalue = u64_to_user_ptr(attr->value);
1790 struct bpf_map *map;
1791 void *key, *value;
1792 u32 value_size;
1793 int err;
1794
1795 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1796 return -EINVAL;
1797
1798 CLASS(fd, f)(attr->map_fd);
1799 map = __bpf_map_get(f);
1800 if (IS_ERR(map))
1801 return PTR_ERR(map);
1802 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1803 return -EPERM;
1804
1805 err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK | BPF_F_CPU);
1806 if (err)
1807 return err;
1808
1809 key = __bpf_copy_key(ukey, map->key_size);
1810 if (IS_ERR(key))
1811 return PTR_ERR(key);
1812
1813 value_size = bpf_map_value_size(map, attr->flags);
1814
1815 err = -ENOMEM;
1816 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1817 if (!value)
1818 goto free_key;
1819
1820 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1821 if (copy_from_user(value, uvalue, value_size))
1822 err = -EFAULT;
1823 else
1824 err = bpf_map_copy_value(map, key, value, attr->flags);
1825 goto free_value;
1826 }
1827
1828 err = bpf_map_copy_value(map, key, value, attr->flags);
1829 if (err)
1830 goto free_value;
1831
1832 err = -EFAULT;
1833 if (copy_to_user(uvalue, value, value_size) != 0)
1834 goto free_value;
1835
1836 err = 0;
1837
1838 free_value:
1839 kvfree(value);
1840 free_key:
1841 kvfree(key);
1842 return err;
1843 }
1844
1845 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1846
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1847 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1848 {
1849 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1850 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1851 struct bpf_map *map;
1852 void *key, *value;
1853 u32 value_size;
1854 int err;
1855
1856 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1857 return -EINVAL;
1858
1859 CLASS(fd, f)(attr->map_fd);
1860 map = __bpf_map_get(f);
1861 if (IS_ERR(map))
1862 return PTR_ERR(map);
1863 bpf_map_write_active_inc(map);
1864 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1865 err = -EPERM;
1866 goto err_put;
1867 }
1868
1869 err = bpf_map_check_op_flags(map, attr->flags, ~0);
1870 if (err)
1871 goto err_put;
1872
1873 key = ___bpf_copy_key(ukey, map->key_size);
1874 if (IS_ERR(key)) {
1875 err = PTR_ERR(key);
1876 goto err_put;
1877 }
1878
1879 value_size = bpf_map_value_size(map, attr->flags);
1880 value = kvmemdup_bpfptr(uvalue, value_size);
1881 if (IS_ERR(value)) {
1882 err = PTR_ERR(value);
1883 goto free_key;
1884 }
1885
1886 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1887 if (!err)
1888 maybe_wait_bpf_programs(map);
1889
1890 kvfree(value);
1891 free_key:
1892 kvfree(key);
1893 err_put:
1894 bpf_map_write_active_dec(map);
1895 return err;
1896 }
1897
1898 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1899
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1900 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1901 {
1902 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1903 struct bpf_map *map;
1904 void *key;
1905 int err;
1906
1907 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1908 return -EINVAL;
1909
1910 CLASS(fd, f)(attr->map_fd);
1911 map = __bpf_map_get(f);
1912 if (IS_ERR(map))
1913 return PTR_ERR(map);
1914 bpf_map_write_active_inc(map);
1915 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1916 err = -EPERM;
1917 goto err_put;
1918 }
1919
1920 key = ___bpf_copy_key(ukey, map->key_size);
1921 if (IS_ERR(key)) {
1922 err = PTR_ERR(key);
1923 goto err_put;
1924 }
1925
1926 if (bpf_map_is_offloaded(map)) {
1927 err = bpf_map_offload_delete_elem(map, key);
1928 goto out;
1929 } else if (IS_FD_PROG_ARRAY(map) ||
1930 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1931 /* These maps require sleepable context */
1932 err = map->ops->map_delete_elem(map, key);
1933 goto out;
1934 }
1935
1936 bpf_disable_instrumentation();
1937 rcu_read_lock();
1938 err = map->ops->map_delete_elem(map, key);
1939 rcu_read_unlock();
1940 bpf_enable_instrumentation();
1941 if (!err)
1942 maybe_wait_bpf_programs(map);
1943 out:
1944 kvfree(key);
1945 err_put:
1946 bpf_map_write_active_dec(map);
1947 return err;
1948 }
1949
1950 /* last field in 'union bpf_attr' used by this command */
1951 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1952
map_get_next_key(union bpf_attr * attr)1953 static int map_get_next_key(union bpf_attr *attr)
1954 {
1955 void __user *ukey = u64_to_user_ptr(attr->key);
1956 void __user *unext_key = u64_to_user_ptr(attr->next_key);
1957 struct bpf_map *map;
1958 void *key, *next_key;
1959 int err;
1960
1961 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1962 return -EINVAL;
1963
1964 CLASS(fd, f)(attr->map_fd);
1965 map = __bpf_map_get(f);
1966 if (IS_ERR(map))
1967 return PTR_ERR(map);
1968 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1969 return -EPERM;
1970
1971 if (ukey) {
1972 key = __bpf_copy_key(ukey, map->key_size);
1973 if (IS_ERR(key))
1974 return PTR_ERR(key);
1975 } else {
1976 key = NULL;
1977 }
1978
1979 err = -ENOMEM;
1980 next_key = kvmalloc(map->key_size, GFP_USER);
1981 if (!next_key)
1982 goto free_key;
1983
1984 if (bpf_map_is_offloaded(map)) {
1985 err = bpf_map_offload_get_next_key(map, key, next_key);
1986 goto out;
1987 }
1988
1989 rcu_read_lock();
1990 err = map->ops->map_get_next_key(map, key, next_key);
1991 rcu_read_unlock();
1992 out:
1993 if (err)
1994 goto free_next_key;
1995
1996 err = -EFAULT;
1997 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1998 goto free_next_key;
1999
2000 err = 0;
2001
2002 free_next_key:
2003 kvfree(next_key);
2004 free_key:
2005 kvfree(key);
2006 return err;
2007 }
2008
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)2009 int generic_map_delete_batch(struct bpf_map *map,
2010 const union bpf_attr *attr,
2011 union bpf_attr __user *uattr)
2012 {
2013 void __user *keys = u64_to_user_ptr(attr->batch.keys);
2014 u32 cp, max_count;
2015 int err = 0;
2016 void *key;
2017
2018 if (attr->batch.elem_flags & ~BPF_F_LOCK)
2019 return -EINVAL;
2020
2021 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
2022 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2023 return -EINVAL;
2024 }
2025
2026 max_count = attr->batch.count;
2027 if (!max_count)
2028 return 0;
2029
2030 if (put_user(0, &uattr->batch.count))
2031 return -EFAULT;
2032
2033 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2034 if (!key)
2035 return -ENOMEM;
2036
2037 for (cp = 0; cp < max_count; cp++) {
2038 err = -EFAULT;
2039 if (copy_from_user(key, keys + cp * map->key_size,
2040 map->key_size))
2041 break;
2042
2043 if (bpf_map_is_offloaded(map)) {
2044 err = bpf_map_offload_delete_elem(map, key);
2045 break;
2046 }
2047
2048 bpf_disable_instrumentation();
2049 rcu_read_lock();
2050 err = map->ops->map_delete_elem(map, key);
2051 rcu_read_unlock();
2052 bpf_enable_instrumentation();
2053 if (err)
2054 break;
2055 cond_resched();
2056 }
2057 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
2058 err = -EFAULT;
2059
2060 kvfree(key);
2061
2062 return err;
2063 }
2064
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)2065 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
2066 const union bpf_attr *attr,
2067 union bpf_attr __user *uattr)
2068 {
2069 void __user *values = u64_to_user_ptr(attr->batch.values);
2070 void __user *keys = u64_to_user_ptr(attr->batch.keys);
2071 u32 value_size, cp, max_count;
2072 void *key, *value;
2073 int err = 0;
2074
2075 err = bpf_map_check_op_flags(map, attr->batch.elem_flags,
2076 BPF_F_LOCK | BPF_F_CPU | BPF_F_ALL_CPUS);
2077 if (err)
2078 return err;
2079
2080 value_size = bpf_map_value_size(map, attr->batch.elem_flags);
2081
2082 max_count = attr->batch.count;
2083 if (!max_count)
2084 return 0;
2085
2086 if (put_user(0, &uattr->batch.count))
2087 return -EFAULT;
2088
2089 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2090 if (!key)
2091 return -ENOMEM;
2092
2093 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2094 if (!value) {
2095 kvfree(key);
2096 return -ENOMEM;
2097 }
2098
2099 for (cp = 0; cp < max_count; cp++) {
2100 err = -EFAULT;
2101 if (copy_from_user(key, keys + cp * map->key_size,
2102 map->key_size) ||
2103 copy_from_user(value, values + cp * value_size, value_size))
2104 break;
2105
2106 err = bpf_map_update_value(map, map_file, key, value,
2107 attr->batch.elem_flags);
2108
2109 if (err)
2110 break;
2111 cond_resched();
2112 }
2113
2114 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
2115 err = -EFAULT;
2116
2117 kvfree(value);
2118 kvfree(key);
2119
2120 return err;
2121 }
2122
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)2123 int generic_map_lookup_batch(struct bpf_map *map,
2124 const union bpf_attr *attr,
2125 union bpf_attr __user *uattr)
2126 {
2127 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
2128 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
2129 void __user *values = u64_to_user_ptr(attr->batch.values);
2130 void __user *keys = u64_to_user_ptr(attr->batch.keys);
2131 void *buf, *buf_prevkey, *prev_key, *key, *value;
2132 u32 value_size, cp, max_count;
2133 int err;
2134
2135 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK | BPF_F_CPU);
2136 if (err)
2137 return err;
2138
2139 value_size = bpf_map_value_size(map, attr->batch.elem_flags);
2140
2141 max_count = attr->batch.count;
2142 if (!max_count)
2143 return 0;
2144
2145 if (put_user(0, &uattr->batch.count))
2146 return -EFAULT;
2147
2148 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2149 if (!buf_prevkey)
2150 return -ENOMEM;
2151
2152 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2153 if (!buf) {
2154 kvfree(buf_prevkey);
2155 return -ENOMEM;
2156 }
2157
2158 err = -EFAULT;
2159 prev_key = NULL;
2160 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2161 goto free_buf;
2162 key = buf;
2163 value = key + map->key_size;
2164 if (ubatch)
2165 prev_key = buf_prevkey;
2166
2167 for (cp = 0; cp < max_count;) {
2168 rcu_read_lock();
2169 err = map->ops->map_get_next_key(map, prev_key, key);
2170 rcu_read_unlock();
2171 if (err)
2172 break;
2173 err = bpf_map_copy_value(map, key, value,
2174 attr->batch.elem_flags);
2175
2176 if (err == -ENOENT)
2177 goto next_key;
2178
2179 if (err)
2180 goto free_buf;
2181
2182 if (copy_to_user(keys + cp * map->key_size, key,
2183 map->key_size)) {
2184 err = -EFAULT;
2185 goto free_buf;
2186 }
2187 if (copy_to_user(values + cp * value_size, value, value_size)) {
2188 err = -EFAULT;
2189 goto free_buf;
2190 }
2191
2192 cp++;
2193 next_key:
2194 if (!prev_key)
2195 prev_key = buf_prevkey;
2196
2197 swap(prev_key, key);
2198 cond_resched();
2199 }
2200
2201 if (err == -EFAULT)
2202 goto free_buf;
2203
2204 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2205 (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2206 err = -EFAULT;
2207
2208 free_buf:
2209 kvfree(buf_prevkey);
2210 kvfree(buf);
2211 return err;
2212 }
2213
2214 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2215
map_lookup_and_delete_elem(union bpf_attr * attr)2216 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2217 {
2218 void __user *ukey = u64_to_user_ptr(attr->key);
2219 void __user *uvalue = u64_to_user_ptr(attr->value);
2220 struct bpf_map *map;
2221 void *key, *value;
2222 u32 value_size;
2223 int err;
2224
2225 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2226 return -EINVAL;
2227
2228 if (attr->flags & ~BPF_F_LOCK)
2229 return -EINVAL;
2230
2231 CLASS(fd, f)(attr->map_fd);
2232 map = __bpf_map_get(f);
2233 if (IS_ERR(map))
2234 return PTR_ERR(map);
2235 bpf_map_write_active_inc(map);
2236 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2237 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2238 err = -EPERM;
2239 goto err_put;
2240 }
2241
2242 if (attr->flags &&
2243 (map->map_type == BPF_MAP_TYPE_QUEUE ||
2244 map->map_type == BPF_MAP_TYPE_STACK)) {
2245 err = -EINVAL;
2246 goto err_put;
2247 }
2248
2249 if ((attr->flags & BPF_F_LOCK) &&
2250 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2251 err = -EINVAL;
2252 goto err_put;
2253 }
2254
2255 key = __bpf_copy_key(ukey, map->key_size);
2256 if (IS_ERR(key)) {
2257 err = PTR_ERR(key);
2258 goto err_put;
2259 }
2260
2261 value_size = bpf_map_value_size(map, 0);
2262
2263 err = -ENOMEM;
2264 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2265 if (!value)
2266 goto free_key;
2267
2268 err = -ENOTSUPP;
2269 if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2270 map->map_type == BPF_MAP_TYPE_STACK) {
2271 err = map->ops->map_pop_elem(map, value);
2272 } else if (map->map_type == BPF_MAP_TYPE_HASH ||
2273 map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2274 map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2275 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
2276 map->map_type == BPF_MAP_TYPE_RHASH ||
2277 map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
2278 if (!bpf_map_is_offloaded(map)) {
2279 bpf_disable_instrumentation();
2280 rcu_read_lock();
2281 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2282 rcu_read_unlock();
2283 bpf_enable_instrumentation();
2284 }
2285 }
2286
2287 if (err)
2288 goto free_value;
2289
2290 if (copy_to_user(uvalue, value, value_size) != 0) {
2291 err = -EFAULT;
2292 goto free_value;
2293 }
2294
2295 err = 0;
2296
2297 free_value:
2298 kvfree(value);
2299 free_key:
2300 kvfree(key);
2301 err_put:
2302 bpf_map_write_active_dec(map);
2303 return err;
2304 }
2305
2306 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2307
map_freeze(const union bpf_attr * attr)2308 static int map_freeze(const union bpf_attr *attr)
2309 {
2310 int err = 0;
2311 struct bpf_map *map;
2312
2313 if (CHECK_ATTR(BPF_MAP_FREEZE))
2314 return -EINVAL;
2315
2316 CLASS(fd, f)(attr->map_fd);
2317 map = __bpf_map_get(f);
2318 if (IS_ERR(map))
2319 return PTR_ERR(map);
2320
2321 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2322 return -ENOTSUPP;
2323
2324 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2325 return -EPERM;
2326
2327 mutex_lock(&map->freeze_mutex);
2328 if (bpf_map_write_active(map)) {
2329 err = -EBUSY;
2330 goto err_put;
2331 }
2332 if (READ_ONCE(map->frozen)) {
2333 err = -EBUSY;
2334 goto err_put;
2335 }
2336
2337 WRITE_ONCE(map->frozen, true);
2338 err_put:
2339 mutex_unlock(&map->freeze_mutex);
2340 return err;
2341 }
2342
2343 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2344 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2345 [_id] = & _name ## _prog_ops,
2346 #define BPF_MAP_TYPE(_id, _ops)
2347 #define BPF_LINK_TYPE(_id, _name)
2348 #include <linux/bpf_types.h>
2349 #undef BPF_PROG_TYPE
2350 #undef BPF_MAP_TYPE
2351 #undef BPF_LINK_TYPE
2352 };
2353
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2354 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2355 {
2356 const struct bpf_prog_ops *ops;
2357
2358 if (type >= ARRAY_SIZE(bpf_prog_types))
2359 return -EINVAL;
2360 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2361 ops = bpf_prog_types[type];
2362 if (!ops)
2363 return -EINVAL;
2364
2365 if (!bpf_prog_is_offloaded(prog->aux))
2366 prog->aux->ops = ops;
2367 else
2368 prog->aux->ops = &bpf_offload_prog_ops;
2369 prog->type = type;
2370 return 0;
2371 }
2372
2373 enum bpf_audit {
2374 BPF_AUDIT_LOAD,
2375 BPF_AUDIT_UNLOAD,
2376 BPF_AUDIT_MAX,
2377 };
2378
2379 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2380 [BPF_AUDIT_LOAD] = "LOAD",
2381 [BPF_AUDIT_UNLOAD] = "UNLOAD",
2382 };
2383
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2384 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2385 {
2386 struct audit_context *ctx = NULL;
2387 struct audit_buffer *ab;
2388
2389 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2390 return;
2391 if (audit_enabled == AUDIT_OFF)
2392 return;
2393 if (!in_hardirq() && !irqs_disabled())
2394 ctx = audit_context();
2395 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2396 if (unlikely(!ab))
2397 return;
2398 audit_log_format(ab, "prog-id=%u op=%s",
2399 prog->aux->id, bpf_audit_str[op]);
2400 audit_log_end(ab);
2401 }
2402
bpf_prog_alloc_id(struct bpf_prog * prog)2403 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2404 {
2405 int id;
2406
2407 idr_preload(GFP_KERNEL);
2408 spin_lock_bh(&prog_idr_lock);
2409 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2410 if (id > 0)
2411 prog->aux->id = id;
2412 spin_unlock_bh(&prog_idr_lock);
2413 idr_preload_end();
2414
2415 /* id is in [1, INT_MAX) */
2416 if (WARN_ON_ONCE(!id))
2417 return -ENOSPC;
2418
2419 return id > 0 ? 0 : id;
2420 }
2421
bpf_prog_free_id(struct bpf_prog * prog)2422 void bpf_prog_free_id(struct bpf_prog *prog)
2423 {
2424 unsigned long flags;
2425
2426 /* cBPF to eBPF migrations are currently not in the idr store.
2427 * Offloaded programs are removed from the store when their device
2428 * disappears - even if someone grabs an fd to them they are unusable,
2429 * simply waiting for refcnt to drop to be freed.
2430 */
2431 if (!prog->aux->id)
2432 return;
2433
2434 spin_lock_irqsave(&prog_idr_lock, flags);
2435 idr_remove(&prog_idr, prog->aux->id);
2436 prog->aux->id = 0;
2437 spin_unlock_irqrestore(&prog_idr_lock, flags);
2438 }
2439
__bpf_prog_put_rcu(struct rcu_head * rcu)2440 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2441 {
2442 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2443
2444 kvfree(aux->func_info);
2445 kfree(aux->func_info_aux);
2446 free_uid(aux->user);
2447 security_bpf_prog_free(aux->prog);
2448 bpf_prog_free(aux->prog);
2449 }
2450
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2451 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2452 {
2453 bpf_prog_kallsyms_del_all(prog);
2454 btf_put(prog->aux->btf);
2455 module_put(prog->aux->mod);
2456 kvfree(prog->aux->jited_linfo);
2457 kvfree(prog->aux->linfo);
2458 kfree(prog->aux->kfunc_tab);
2459 kfree(prog->aux->ctx_arg_info);
2460 if (prog->aux->attach_btf)
2461 btf_put(prog->aux->attach_btf);
2462
2463 if (deferred) {
2464 if (prog->sleepable)
2465 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2466 else
2467 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2468 } else {
2469 __bpf_prog_put_rcu(&prog->aux->rcu);
2470 }
2471 }
2472
bpf_prog_put_deferred(struct work_struct * work)2473 static void bpf_prog_put_deferred(struct work_struct *work)
2474 {
2475 struct bpf_prog_aux *aux;
2476 struct bpf_prog *prog;
2477
2478 aux = container_of(work, struct bpf_prog_aux, work);
2479 prog = aux->prog;
2480 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2481 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2482 bpf_prog_free_id(prog);
2483 __bpf_prog_put_noref(prog, true);
2484 }
2485
__bpf_prog_put(struct bpf_prog * prog)2486 static void __bpf_prog_put(struct bpf_prog *prog)
2487 {
2488 struct bpf_prog_aux *aux = prog->aux;
2489
2490 if (atomic64_dec_and_test(&aux->refcnt)) {
2491 if (in_hardirq() || irqs_disabled()) {
2492 INIT_WORK(&aux->work, bpf_prog_put_deferred);
2493 schedule_work(&aux->work);
2494 } else {
2495 bpf_prog_put_deferred(&aux->work);
2496 }
2497 }
2498 }
2499
bpf_prog_put(struct bpf_prog * prog)2500 void bpf_prog_put(struct bpf_prog *prog)
2501 {
2502 __bpf_prog_put(prog);
2503 }
2504 EXPORT_SYMBOL_GPL(bpf_prog_put);
2505
bpf_prog_release(struct inode * inode,struct file * filp)2506 static int bpf_prog_release(struct inode *inode, struct file *filp)
2507 {
2508 struct bpf_prog *prog = filp->private_data;
2509
2510 bpf_prog_put(prog);
2511 return 0;
2512 }
2513
2514 struct bpf_prog_kstats {
2515 u64 nsecs;
2516 u64 cnt;
2517 u64 misses;
2518 };
2519
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2520 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2521 {
2522 struct bpf_prog_stats *stats;
2523 unsigned int flags;
2524
2525 if (unlikely(!prog->stats))
2526 return;
2527
2528 stats = this_cpu_ptr(prog->stats);
2529 flags = u64_stats_update_begin_irqsave(&stats->syncp);
2530 u64_stats_inc(&stats->misses);
2531 u64_stats_update_end_irqrestore(&stats->syncp, flags);
2532 }
2533
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2534 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2535 struct bpf_prog_kstats *stats)
2536 {
2537 u64 nsecs = 0, cnt = 0, misses = 0;
2538 int cpu;
2539
2540 for_each_possible_cpu(cpu) {
2541 const struct bpf_prog_stats *st;
2542 unsigned int start;
2543 u64 tnsecs, tcnt, tmisses;
2544
2545 st = per_cpu_ptr(prog->stats, cpu);
2546 do {
2547 start = u64_stats_fetch_begin(&st->syncp);
2548 tnsecs = u64_stats_read(&st->nsecs);
2549 tcnt = u64_stats_read(&st->cnt);
2550 tmisses = u64_stats_read(&st->misses);
2551 } while (u64_stats_fetch_retry(&st->syncp, start));
2552 nsecs += tnsecs;
2553 cnt += tcnt;
2554 misses += tmisses;
2555 }
2556 stats->nsecs = nsecs;
2557 stats->cnt = cnt;
2558 stats->misses = misses;
2559 }
2560
2561 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2562 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2563 {
2564 const struct bpf_prog *prog = filp->private_data;
2565 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2566 struct bpf_prog_kstats stats;
2567
2568 bpf_prog_get_stats(prog, &stats);
2569 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2570 seq_printf(m,
2571 "prog_type:\t%u\n"
2572 "prog_jited:\t%u\n"
2573 "prog_tag:\t%s\n"
2574 "memlock:\t%llu\n"
2575 "prog_id:\t%u\n"
2576 "run_time_ns:\t%llu\n"
2577 "run_cnt:\t%llu\n"
2578 "recursion_misses:\t%llu\n"
2579 "verified_insns:\t%u\n",
2580 prog->type,
2581 prog->jited,
2582 prog_tag,
2583 prog->pages * 1ULL << PAGE_SHIFT,
2584 prog->aux->id,
2585 stats.nsecs,
2586 stats.cnt,
2587 stats.misses,
2588 prog->aux->verified_insns);
2589 }
2590 #endif
2591
2592 const struct file_operations bpf_prog_fops = {
2593 #ifdef CONFIG_PROC_FS
2594 .show_fdinfo = bpf_prog_show_fdinfo,
2595 #endif
2596 .release = bpf_prog_release,
2597 .read = bpf_dummy_read,
2598 .write = bpf_dummy_write,
2599 };
2600
bpf_prog_new_fd(struct bpf_prog * prog)2601 int bpf_prog_new_fd(struct bpf_prog *prog)
2602 {
2603 int ret;
2604
2605 ret = security_bpf_prog(prog);
2606 if (ret < 0)
2607 return ret;
2608
2609 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2610 O_RDWR | O_CLOEXEC);
2611 }
2612
bpf_prog_add(struct bpf_prog * prog,int i)2613 void bpf_prog_add(struct bpf_prog *prog, int i)
2614 {
2615 atomic64_add(i, &prog->aux->refcnt);
2616 }
2617 EXPORT_SYMBOL_GPL(bpf_prog_add);
2618
bpf_prog_sub(struct bpf_prog * prog,int i)2619 void bpf_prog_sub(struct bpf_prog *prog, int i)
2620 {
2621 /* Only to be used for undoing previous bpf_prog_add() in some
2622 * error path. We still know that another entity in our call
2623 * path holds a reference to the program, thus atomic_sub() can
2624 * be safely used in such cases!
2625 */
2626 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2627 }
2628 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2629
bpf_prog_inc(struct bpf_prog * prog)2630 void bpf_prog_inc(struct bpf_prog *prog)
2631 {
2632 atomic64_inc(&prog->aux->refcnt);
2633 }
2634 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2635
2636 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2637 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2638 {
2639 int refold;
2640
2641 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2642
2643 if (!refold)
2644 return ERR_PTR(-ENOENT);
2645
2646 return prog;
2647 }
2648 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2649
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2650 bool bpf_prog_get_ok(struct bpf_prog *prog,
2651 enum bpf_prog_type *attach_type, bool attach_drv)
2652 {
2653 /* not an attachment, just a refcount inc, always allow */
2654 if (!attach_type)
2655 return true;
2656
2657 if (prog->type != *attach_type)
2658 return false;
2659 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2660 return false;
2661
2662 return true;
2663 }
2664
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2665 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2666 bool attach_drv)
2667 {
2668 CLASS(fd, f)(ufd);
2669 struct bpf_prog *prog;
2670
2671 if (fd_empty(f))
2672 return ERR_PTR(-EBADF);
2673 if (fd_file(f)->f_op != &bpf_prog_fops)
2674 return ERR_PTR(-EINVAL);
2675
2676 prog = fd_file(f)->private_data;
2677 if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2678 return ERR_PTR(-EINVAL);
2679
2680 bpf_prog_inc(prog);
2681 return prog;
2682 }
2683
bpf_prog_get(u32 ufd)2684 struct bpf_prog *bpf_prog_get(u32 ufd)
2685 {
2686 return __bpf_prog_get(ufd, NULL, false);
2687 }
2688
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2689 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2690 bool attach_drv)
2691 {
2692 return __bpf_prog_get(ufd, &type, attach_drv);
2693 }
2694 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2695
2696 /* Initially all BPF programs could be loaded w/o specifying
2697 * expected_attach_type. Later for some of them specifying expected_attach_type
2698 * at load time became required so that program could be validated properly.
2699 * Programs of types that are allowed to be loaded both w/ and w/o (for
2700 * backward compatibility) expected_attach_type, should have the default attach
2701 * type assigned to expected_attach_type for the latter case, so that it can be
2702 * validated later at attach time.
2703 *
2704 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2705 * prog type requires it but has some attach types that have to be backward
2706 * compatible.
2707 */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2708 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2709 {
2710 switch (attr->prog_type) {
2711 case BPF_PROG_TYPE_CGROUP_SOCK:
2712 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2713 * exist so checking for non-zero is the way to go here.
2714 */
2715 if (!attr->expected_attach_type)
2716 attr->expected_attach_type =
2717 BPF_CGROUP_INET_SOCK_CREATE;
2718 break;
2719 case BPF_PROG_TYPE_SK_REUSEPORT:
2720 if (!attr->expected_attach_type)
2721 attr->expected_attach_type =
2722 BPF_SK_REUSEPORT_SELECT;
2723 break;
2724 }
2725 }
2726
2727 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,bool multi_func)2728 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2729 enum bpf_attach_type expected_attach_type,
2730 struct btf *attach_btf, u32 btf_id,
2731 struct bpf_prog *dst_prog,
2732 bool multi_func)
2733 {
2734 if (btf_id) {
2735 if (btf_id > BTF_MAX_TYPE)
2736 return -EINVAL;
2737
2738 if (!attach_btf && !dst_prog)
2739 return -EINVAL;
2740
2741 switch (prog_type) {
2742 case BPF_PROG_TYPE_TRACING:
2743 case BPF_PROG_TYPE_LSM:
2744 case BPF_PROG_TYPE_STRUCT_OPS:
2745 case BPF_PROG_TYPE_EXT:
2746 break;
2747 default:
2748 return -EINVAL;
2749 }
2750 }
2751
2752 if (multi_func) {
2753 if (prog_type != BPF_PROG_TYPE_TRACING)
2754 return -EINVAL;
2755 if (!attach_btf || btf_id)
2756 return -EINVAL;
2757 return 0;
2758 }
2759
2760 if (attach_btf && (!btf_id || dst_prog))
2761 return -EINVAL;
2762
2763 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2764 prog_type != BPF_PROG_TYPE_EXT)
2765 return -EINVAL;
2766
2767 switch (prog_type) {
2768 case BPF_PROG_TYPE_CGROUP_SOCK:
2769 switch (expected_attach_type) {
2770 case BPF_CGROUP_INET_SOCK_CREATE:
2771 case BPF_CGROUP_INET_SOCK_RELEASE:
2772 case BPF_CGROUP_INET4_POST_BIND:
2773 case BPF_CGROUP_INET6_POST_BIND:
2774 return 0;
2775 default:
2776 return -EINVAL;
2777 }
2778 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2779 switch (expected_attach_type) {
2780 case BPF_CGROUP_INET4_BIND:
2781 case BPF_CGROUP_INET6_BIND:
2782 case BPF_CGROUP_INET4_CONNECT:
2783 case BPF_CGROUP_INET6_CONNECT:
2784 case BPF_CGROUP_UNIX_CONNECT:
2785 case BPF_CGROUP_INET4_GETPEERNAME:
2786 case BPF_CGROUP_INET6_GETPEERNAME:
2787 case BPF_CGROUP_UNIX_GETPEERNAME:
2788 case BPF_CGROUP_INET4_GETSOCKNAME:
2789 case BPF_CGROUP_INET6_GETSOCKNAME:
2790 case BPF_CGROUP_UNIX_GETSOCKNAME:
2791 case BPF_CGROUP_UDP4_SENDMSG:
2792 case BPF_CGROUP_UDP6_SENDMSG:
2793 case BPF_CGROUP_UNIX_SENDMSG:
2794 case BPF_CGROUP_UDP4_RECVMSG:
2795 case BPF_CGROUP_UDP6_RECVMSG:
2796 case BPF_CGROUP_UNIX_RECVMSG:
2797 return 0;
2798 default:
2799 return -EINVAL;
2800 }
2801 case BPF_PROG_TYPE_CGROUP_SKB:
2802 switch (expected_attach_type) {
2803 case BPF_CGROUP_INET_INGRESS:
2804 case BPF_CGROUP_INET_EGRESS:
2805 return 0;
2806 default:
2807 return -EINVAL;
2808 }
2809 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2810 switch (expected_attach_type) {
2811 case BPF_CGROUP_SETSOCKOPT:
2812 case BPF_CGROUP_GETSOCKOPT:
2813 return 0;
2814 default:
2815 return -EINVAL;
2816 }
2817 case BPF_PROG_TYPE_SK_LOOKUP:
2818 if (expected_attach_type == BPF_SK_LOOKUP)
2819 return 0;
2820 return -EINVAL;
2821 case BPF_PROG_TYPE_SK_REUSEPORT:
2822 switch (expected_attach_type) {
2823 case BPF_SK_REUSEPORT_SELECT:
2824 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2825 return 0;
2826 default:
2827 return -EINVAL;
2828 }
2829 case BPF_PROG_TYPE_NETFILTER:
2830 if (expected_attach_type == BPF_NETFILTER)
2831 return 0;
2832 return -EINVAL;
2833 case BPF_PROG_TYPE_SYSCALL:
2834 case BPF_PROG_TYPE_EXT:
2835 if (expected_attach_type)
2836 return -EINVAL;
2837 fallthrough;
2838 default:
2839 return 0;
2840 }
2841 }
2842
is_net_admin_prog_type(enum bpf_prog_type prog_type)2843 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2844 {
2845 switch (prog_type) {
2846 case BPF_PROG_TYPE_SCHED_CLS:
2847 case BPF_PROG_TYPE_SCHED_ACT:
2848 case BPF_PROG_TYPE_XDP:
2849 case BPF_PROG_TYPE_LWT_IN:
2850 case BPF_PROG_TYPE_LWT_OUT:
2851 case BPF_PROG_TYPE_LWT_XMIT:
2852 case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2853 case BPF_PROG_TYPE_SK_SKB:
2854 case BPF_PROG_TYPE_SK_MSG:
2855 case BPF_PROG_TYPE_FLOW_DISSECTOR:
2856 case BPF_PROG_TYPE_CGROUP_DEVICE:
2857 case BPF_PROG_TYPE_CGROUP_SOCK:
2858 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2859 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2860 case BPF_PROG_TYPE_CGROUP_SYSCTL:
2861 case BPF_PROG_TYPE_SOCK_OPS:
2862 case BPF_PROG_TYPE_EXT: /* extends any prog */
2863 case BPF_PROG_TYPE_NETFILTER:
2864 return true;
2865 case BPF_PROG_TYPE_CGROUP_SKB:
2866 /* always unpriv */
2867 case BPF_PROG_TYPE_SK_REUSEPORT:
2868 /* equivalent to SOCKET_FILTER. need CAP_BPF only */
2869 default:
2870 return false;
2871 }
2872 }
2873
is_perfmon_prog_type(enum bpf_prog_type prog_type)2874 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2875 {
2876 switch (prog_type) {
2877 case BPF_PROG_TYPE_KPROBE:
2878 case BPF_PROG_TYPE_TRACEPOINT:
2879 case BPF_PROG_TYPE_PERF_EVENT:
2880 case BPF_PROG_TYPE_RAW_TRACEPOINT:
2881 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2882 case BPF_PROG_TYPE_TRACING:
2883 case BPF_PROG_TYPE_LSM:
2884 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2885 case BPF_PROG_TYPE_EXT: /* extends any prog */
2886 return true;
2887 default:
2888 return false;
2889 }
2890 }
2891
bpf_prog_mark_insn_arrays_ready(struct bpf_prog * prog)2892 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog)
2893 {
2894 int err;
2895 int i;
2896
2897 for (i = 0; i < prog->aux->used_map_cnt; i++) {
2898 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY)
2899 continue;
2900
2901 err = bpf_insn_array_ready(prog->aux->used_maps[i]);
2902 if (err)
2903 return err;
2904 }
2905
2906 return 0;
2907 }
2908
2909 extern int bpf_multi_func(void);
bpf_multi_func(void)2910 int __init __used bpf_multi_func(void) { return 0; }
2911
BTF_ID_LIST_GLOBAL_SINGLE(bpf_multi_func_btf_id,func,bpf_multi_func)2912 BTF_ID_LIST_GLOBAL_SINGLE(bpf_multi_func_btf_id, func, bpf_multi_func)
2913
2914 /* last field in 'union bpf_attr' used by this command */
2915 #define BPF_PROG_LOAD_LAST_FIELD keyring_id
2916
2917 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log)
2918 {
2919 enum bpf_prog_type type = attr->prog_type;
2920 struct bpf_prog *prog, *dst_prog = NULL;
2921 struct btf *attach_btf = NULL;
2922 struct bpf_token *token = NULL;
2923 bool bpf_cap;
2924 int err;
2925 char license[128];
2926 bool multi_func;
2927
2928 if (CHECK_ATTR(BPF_PROG_LOAD))
2929 return -EINVAL;
2930
2931 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2932 BPF_F_ANY_ALIGNMENT |
2933 BPF_F_TEST_STATE_FREQ |
2934 BPF_F_SLEEPABLE |
2935 BPF_F_TEST_RND_HI32 |
2936 BPF_F_XDP_HAS_FRAGS |
2937 BPF_F_XDP_DEV_BOUND_ONLY |
2938 BPF_F_TEST_REG_INVARIANTS |
2939 BPF_F_TOKEN_FD))
2940 return -EINVAL;
2941
2942 bpf_prog_load_fixup_attach_type(attr);
2943
2944 if (attr->prog_flags & BPF_F_TOKEN_FD) {
2945 token = bpf_token_get_from_fd(attr->prog_token_fd);
2946 if (IS_ERR(token))
2947 return PTR_ERR(token);
2948 /* if current token doesn't grant prog loading permissions,
2949 * then we can't use this token, so ignore it and rely on
2950 * system-wide capabilities checks
2951 */
2952 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2953 !bpf_token_allow_prog_type(token, attr->prog_type,
2954 attr->expected_attach_type)) {
2955 bpf_token_put(token);
2956 token = NULL;
2957 }
2958 }
2959
2960 bpf_cap = bpf_token_capable(token, CAP_BPF);
2961 err = -EPERM;
2962
2963 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2964 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2965 !bpf_cap)
2966 goto put_token;
2967
2968 /* Intent here is for unprivileged_bpf_disabled to block BPF program
2969 * creation for unprivileged users; other actions depend
2970 * on fd availability and access to bpffs, so are dependent on
2971 * object creation success. Even with unprivileged BPF disabled,
2972 * capability checks are still carried out for these
2973 * and other operations.
2974 */
2975 if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2976 goto put_token;
2977
2978 if (attr->insn_cnt == 0 ||
2979 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2980 err = -E2BIG;
2981 goto put_token;
2982 }
2983 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2984 type != BPF_PROG_TYPE_CGROUP_SKB &&
2985 !bpf_cap)
2986 goto put_token;
2987
2988 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2989 goto put_token;
2990 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2991 goto put_token;
2992
2993 multi_func = is_tracing_multi(attr->expected_attach_type);
2994
2995 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2996 * or btf, we need to check which one it is
2997 */
2998 if (attr->attach_prog_fd) {
2999 dst_prog = bpf_prog_get(attr->attach_prog_fd);
3000 if (IS_ERR(dst_prog)) {
3001 dst_prog = NULL;
3002 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
3003 if (IS_ERR(attach_btf)) {
3004 err = -EINVAL;
3005 goto put_token;
3006 }
3007 if (!btf_is_kernel(attach_btf)) {
3008 /* attaching through specifying bpf_prog's BTF
3009 * objects directly might be supported eventually
3010 */
3011 btf_put(attach_btf);
3012 err = -ENOTSUPP;
3013 goto put_token;
3014 }
3015 }
3016 } else if (attr->attach_btf_id || multi_func) {
3017 /* fall back to vmlinux BTF, if BTF type ID is specified */
3018 attach_btf = bpf_get_btf_vmlinux();
3019 if (IS_ERR(attach_btf)) {
3020 err = PTR_ERR(attach_btf);
3021 goto put_token;
3022 }
3023 if (!attach_btf) {
3024 err = -EINVAL;
3025 goto put_token;
3026 }
3027 btf_get(attach_btf);
3028 }
3029
3030 if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
3031 attach_btf, attr->attach_btf_id,
3032 dst_prog, multi_func)) {
3033 if (dst_prog)
3034 bpf_prog_put(dst_prog);
3035 if (attach_btf)
3036 btf_put(attach_btf);
3037 err = -EINVAL;
3038 goto put_token;
3039 }
3040
3041 /* plain bpf_prog allocation */
3042 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
3043 if (!prog) {
3044 if (dst_prog)
3045 bpf_prog_put(dst_prog);
3046 if (attach_btf)
3047 btf_put(attach_btf);
3048 err = -EINVAL;
3049 goto put_token;
3050 }
3051
3052 prog->expected_attach_type = attr->expected_attach_type;
3053 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
3054 prog->aux->attach_btf = attach_btf;
3055 prog->aux->attach_btf_id = multi_func ? bpf_multi_func_btf_id[0] : attr->attach_btf_id;
3056 prog->aux->dst_prog = dst_prog;
3057 if (dst_prog) {
3058 prog->aux->saved_dst_prog_type = dst_prog->type;
3059 prog->aux->saved_dst_attach_type = dst_prog->expected_attach_type;
3060 }
3061 prog->aux->dev_bound = !!attr->prog_ifindex;
3062 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
3063
3064 /* move token into prog->aux, reuse taken refcnt */
3065 prog->aux->token = token;
3066 token = NULL;
3067
3068 prog->aux->user = get_current_user();
3069 prog->len = attr->insn_cnt;
3070
3071 err = -EFAULT;
3072 if (copy_from_bpfptr(prog->insns,
3073 make_bpfptr(attr->insns, uattr.is_kernel),
3074 bpf_prog_insn_size(prog)) != 0)
3075 goto free_prog;
3076 /* copy eBPF program license from user space */
3077 if (strncpy_from_bpfptr(license,
3078 make_bpfptr(attr->license, uattr.is_kernel),
3079 sizeof(license) - 1) < 0)
3080 goto free_prog;
3081 license[sizeof(license) - 1] = 0;
3082
3083 /* eBPF programs must be GPL compatible to use GPL-ed functions */
3084 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
3085 prog->aux->sig.keyring_type = BPF_SIG_KEYRING_NONE;
3086 prog->aux->sig.verdict = BPF_SIG_UNSIGNED;
3087 prog->orig_prog = NULL;
3088 prog->jited = 0;
3089
3090 atomic64_set(&prog->aux->refcnt, 1);
3091
3092 if (bpf_prog_is_dev_bound(prog->aux)) {
3093 err = bpf_prog_dev_bound_init(prog, attr);
3094 if (err)
3095 goto free_prog;
3096 }
3097
3098 if (type == BPF_PROG_TYPE_EXT && dst_prog &&
3099 bpf_prog_is_dev_bound(dst_prog->aux)) {
3100 err = bpf_prog_dev_bound_inherit(prog, dst_prog);
3101 if (err)
3102 goto free_prog;
3103 }
3104
3105 /*
3106 * Bookkeeping for managing the program attachment chain.
3107 *
3108 * It might be tempting to set attach_tracing_prog flag at the attachment
3109 * time, but this will not prevent from loading bunch of tracing prog
3110 * first, then attach them one to another.
3111 *
3112 * The flag attach_tracing_prog is set for the whole program lifecycle, and
3113 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
3114 * programs cannot change attachment target.
3115 */
3116 if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
3117 dst_prog->type == BPF_PROG_TYPE_TRACING) {
3118 prog->aux->attach_tracing_prog = true;
3119 }
3120
3121 /* find program type: socket_filter vs tracing_filter */
3122 err = find_prog_type(type, prog);
3123 if (err < 0)
3124 goto free_prog;
3125
3126 prog->aux->load_time = ktime_get_boottime_ns();
3127 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
3128 sizeof(attr->prog_name));
3129 if (err < 0)
3130 goto free_prog;
3131
3132 /* run eBPF verifier */
3133 err = bpf_check(&prog, attr, uattr, attr_log);
3134 if (err < 0)
3135 goto free_used_maps;
3136
3137 err = bpf_prog_mark_insn_arrays_ready(prog);
3138 if (err < 0)
3139 goto free_used_maps;
3140
3141 err = bpf_prog_alloc_id(prog);
3142 if (err)
3143 goto free_used_maps;
3144
3145 /* Upon success of bpf_prog_alloc_id(), the BPF prog is
3146 * effectively publicly exposed. However, retrieving via
3147 * bpf_prog_get_fd_by_id() will take another reference,
3148 * therefore it cannot be gone underneath us.
3149 *
3150 * Only for the time /after/ successful bpf_prog_new_fd()
3151 * and before returning to userspace, we might just hold
3152 * one reference and any parallel close on that fd could
3153 * rip everything out. Hence, below notifications must
3154 * happen before bpf_prog_new_fd().
3155 *
3156 * Also, any failure handling from this point onwards must
3157 * be using bpf_prog_put() given the program is exposed.
3158 */
3159 bpf_prog_kallsyms_add(prog);
3160 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
3161 bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3162
3163 err = bpf_prog_new_fd(prog);
3164 if (err < 0)
3165 bpf_prog_put(prog);
3166 return err;
3167
3168 free_used_maps:
3169 /* In case we have subprogs, we need to wait for a grace
3170 * period before we can tear down JIT memory since symbols
3171 * are already exposed under kallsyms.
3172 */
3173 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3174 return err;
3175
3176 free_prog:
3177 free_uid(prog->aux->user);
3178 if (prog->aux->attach_btf)
3179 btf_put(prog->aux->attach_btf);
3180 bpf_prog_free(prog);
3181 put_token:
3182 bpf_token_put(token);
3183 return err;
3184 }
3185
3186 #define BPF_OBJ_LAST_FIELD path_fd
3187
bpf_obj_pin(const union bpf_attr * attr)3188 static int bpf_obj_pin(const union bpf_attr *attr)
3189 {
3190 int path_fd;
3191
3192 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3193 return -EINVAL;
3194
3195 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3196 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3197 return -EINVAL;
3198
3199 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3200 return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3201 u64_to_user_ptr(attr->pathname));
3202 }
3203
bpf_obj_get(const union bpf_attr * attr)3204 static int bpf_obj_get(const union bpf_attr *attr)
3205 {
3206 int path_fd;
3207
3208 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3209 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3210 return -EINVAL;
3211
3212 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3213 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3214 return -EINVAL;
3215
3216 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3217 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3218 attr->file_flags);
3219 }
3220
3221 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3222 * "sleepable" semantics, which normally would mean that BPF link's attach
3223 * hook can dereference link or link's underlying program for some time after
3224 * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3225 * BPF program itself can be non-sleepable, yet, because it's transitively
3226 * reachable through BPF link, its freeing has to be delayed until after RCU
3227 * Tasks Trace GP.
3228 */
bpf_link_init_sleepable(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type,bool sleepable)3229 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3230 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3231 enum bpf_attach_type attach_type, bool sleepable)
3232 {
3233 WARN_ON(ops->dealloc && ops->dealloc_deferred);
3234 atomic64_set(&link->refcnt, 1);
3235 link->type = type;
3236 link->sleepable = sleepable;
3237 link->id = 0;
3238 link->ops = ops;
3239 link->prog = prog;
3240 link->attach_type = attach_type;
3241 }
3242
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type)3243 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3244 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3245 enum bpf_attach_type attach_type)
3246 {
3247 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false);
3248 }
3249
bpf_tramp_link_init(struct bpf_tramp_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type,u64 cookie)3250 void bpf_tramp_link_init(struct bpf_tramp_link *link, enum bpf_link_type type,
3251 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3252 enum bpf_attach_type attach_type, u64 cookie)
3253 {
3254 bpf_link_init(&link->link, type, ops, prog, attach_type);
3255 link->node.link = &link->link;
3256 link->node.cookie = cookie;
3257 }
3258
bpf_link_free_id(int id)3259 static void bpf_link_free_id(int id)
3260 {
3261 if (!id)
3262 return;
3263
3264 spin_lock_bh(&link_idr_lock);
3265 idr_remove(&link_idr, id);
3266 spin_unlock_bh(&link_idr_lock);
3267 }
3268
3269 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3270 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3271 * anon_inode's release() call. This helper marks bpf_link as
3272 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3273 * is not decremented, it's the responsibility of a calling code that failed
3274 * to complete bpf_link initialization.
3275 * This helper eventually calls link's dealloc callback, but does not call
3276 * link's release callback.
3277 */
bpf_link_cleanup(struct bpf_link_primer * primer)3278 void bpf_link_cleanup(struct bpf_link_primer *primer)
3279 {
3280 primer->link->prog = NULL;
3281 bpf_link_free_id(primer->id);
3282 fput(primer->file);
3283 put_unused_fd(primer->fd);
3284 }
3285
bpf_link_inc(struct bpf_link * link)3286 void bpf_link_inc(struct bpf_link *link)
3287 {
3288 atomic64_inc(&link->refcnt);
3289 }
3290
bpf_link_dealloc(struct bpf_link * link)3291 static void bpf_link_dealloc(struct bpf_link *link)
3292 {
3293 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3294 if (link->prog)
3295 bpf_prog_put(link->prog);
3296
3297 /* free bpf_link and its containing memory */
3298 if (link->ops->dealloc_deferred)
3299 link->ops->dealloc_deferred(link);
3300 else
3301 link->ops->dealloc(link);
3302 }
3303
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3304 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3305 {
3306 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3307
3308 bpf_link_dealloc(link);
3309 }
3310
bpf_link_is_tracepoint(struct bpf_link * link)3311 static bool bpf_link_is_tracepoint(struct bpf_link *link)
3312 {
3313 /*
3314 * Only these combinations support a tracepoint bpf_link.
3315 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use
3316 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see
3317 * bpf_raw_tp_link_attach().
3318 */
3319 return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT ||
3320 (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP);
3321 }
3322
3323 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3324 static void bpf_link_free(struct bpf_link *link)
3325 {
3326 const struct bpf_link_ops *ops = link->ops;
3327
3328 bpf_link_free_id(link->id);
3329 /* detach BPF program, clean up used resources */
3330 if (link->prog)
3331 ops->release(link);
3332 if (ops->dealloc_deferred) {
3333 /*
3334 * Schedule BPF link deallocation, which will only then
3335 * trigger putting BPF program refcount.
3336 * If underlying BPF program is sleepable or BPF link's target
3337 * attach hookpoint is sleepable or otherwise requires RCU GPs
3338 * to ensure link and its underlying BPF program is not
3339 * reachable anymore, we need to first wait for RCU tasks
3340 * trace sync, and then go through "classic" RCU grace period.
3341 *
3342 * For tracepoint BPF links, we need to go through SRCU grace
3343 * period wait instead when non-faultable tracepoint is used. We
3344 * don't need to chain SRCU grace period waits, however, for the
3345 * faultable case, since it exclusively uses RCU Tasks Trace.
3346 */
3347 if (link->sleepable || (link->prog && link->prog->sleepable))
3348 /* RCU Tasks Trace grace period implies RCU grace period. */
3349 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3350 /* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */
3351 else if (bpf_link_is_tracepoint(link))
3352 call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3353 else
3354 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3355 } else if (ops->dealloc) {
3356 bpf_link_dealloc(link);
3357 }
3358 }
3359
bpf_link_put_deferred(struct work_struct * work)3360 static void bpf_link_put_deferred(struct work_struct *work)
3361 {
3362 struct bpf_link *link = container_of(work, struct bpf_link, work);
3363
3364 bpf_link_free(link);
3365 }
3366
3367 /* bpf_link_put might be called from atomic context. It needs to be called
3368 * from sleepable context in order to acquire sleeping locks during the process.
3369 */
bpf_link_put(struct bpf_link * link)3370 void bpf_link_put(struct bpf_link *link)
3371 {
3372 if (!atomic64_dec_and_test(&link->refcnt))
3373 return;
3374
3375 INIT_WORK(&link->work, bpf_link_put_deferred);
3376 schedule_work(&link->work);
3377 }
3378 EXPORT_SYMBOL(bpf_link_put);
3379
bpf_link_put_direct(struct bpf_link * link)3380 static void bpf_link_put_direct(struct bpf_link *link)
3381 {
3382 if (!atomic64_dec_and_test(&link->refcnt))
3383 return;
3384 bpf_link_free(link);
3385 }
3386
bpf_link_release(struct inode * inode,struct file * filp)3387 static int bpf_link_release(struct inode *inode, struct file *filp)
3388 {
3389 struct bpf_link *link = filp->private_data;
3390
3391 bpf_link_put_direct(link);
3392 return 0;
3393 }
3394
3395 #ifdef CONFIG_PROC_FS
3396 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3397 #define BPF_MAP_TYPE(_id, _ops)
3398 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3399 static const char *bpf_link_type_strs[] = {
3400 [BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3401 #include <linux/bpf_types.h>
3402 };
3403 #undef BPF_PROG_TYPE
3404 #undef BPF_MAP_TYPE
3405 #undef BPF_LINK_TYPE
3406
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3407 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3408 {
3409 const struct bpf_link *link = filp->private_data;
3410 const struct bpf_prog *prog;
3411 enum bpf_link_type type = link->type;
3412 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3413 u32 prog_id = 0;
3414
3415 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3416 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI)
3417 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ?
3418 "kretprobe_multi" : "kprobe_multi");
3419 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI)
3420 seq_printf(m, "link_type:\t%s\n", link->flags & BPF_F_UPROBE_MULTI_RETURN ?
3421 "uretprobe_multi" : "uprobe_multi");
3422 else
3423 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3424 } else {
3425 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3426 seq_printf(m, "link_type:\t<%u>\n", type);
3427 }
3428 seq_printf(m, "link_id:\t%u\n", link->id);
3429
3430 rcu_read_lock();
3431 prog = READ_ONCE(link->prog);
3432 if (prog) {
3433 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3434 prog_id = prog->aux->id;
3435 }
3436 rcu_read_unlock();
3437
3438 if (prog) {
3439 seq_printf(m,
3440 "prog_tag:\t%s\n"
3441 "prog_id:\t%u\n",
3442 prog_tag,
3443 prog_id);
3444 }
3445 if (link->ops->show_fdinfo)
3446 link->ops->show_fdinfo(link, m);
3447 }
3448 #endif
3449
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3450 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3451 {
3452 struct bpf_link *link = file->private_data;
3453
3454 return link->ops->poll(file, pts);
3455 }
3456
3457 static const struct file_operations bpf_link_fops = {
3458 #ifdef CONFIG_PROC_FS
3459 .show_fdinfo = bpf_link_show_fdinfo,
3460 #endif
3461 .release = bpf_link_release,
3462 .read = bpf_dummy_read,
3463 .write = bpf_dummy_write,
3464 };
3465
3466 static const struct file_operations bpf_link_fops_poll = {
3467 #ifdef CONFIG_PROC_FS
3468 .show_fdinfo = bpf_link_show_fdinfo,
3469 #endif
3470 .release = bpf_link_release,
3471 .read = bpf_dummy_read,
3472 .write = bpf_dummy_write,
3473 .poll = bpf_link_poll,
3474 };
3475
bpf_link_alloc_id(struct bpf_link * link)3476 static int bpf_link_alloc_id(struct bpf_link *link)
3477 {
3478 int id;
3479
3480 idr_preload(GFP_KERNEL);
3481 spin_lock_bh(&link_idr_lock);
3482 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3483 spin_unlock_bh(&link_idr_lock);
3484 idr_preload_end();
3485
3486 return id;
3487 }
3488
3489 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3490 * reserving unused FD and allocating ID from link_idr. This is to be paired
3491 * with bpf_link_settle() to install FD and ID and expose bpf_link to
3492 * user-space, if bpf_link is successfully attached. If not, bpf_link and
3493 * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3494 * transient state is passed around in struct bpf_link_primer.
3495 * This is preferred way to create and initialize bpf_link, especially when
3496 * there are complicated and expensive operations in between creating bpf_link
3497 * itself and attaching it to BPF hook. By using bpf_link_prime() and
3498 * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3499 * expensive (and potentially failing) roll back operations in a rare case
3500 * that file, FD, or ID can't be allocated.
3501 */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3502 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3503 {
3504 struct file *file;
3505 int fd, id;
3506
3507 fd = get_unused_fd_flags(O_CLOEXEC);
3508 if (fd < 0)
3509 return fd;
3510
3511 id = bpf_link_alloc_id(link);
3512 if (id < 0) {
3513 put_unused_fd(fd);
3514 return id;
3515 }
3516
3517 file = anon_inode_getfile("bpf_link",
3518 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3519 link, O_CLOEXEC);
3520 if (IS_ERR(file)) {
3521 bpf_link_free_id(id);
3522 put_unused_fd(fd);
3523 return PTR_ERR(file);
3524 }
3525
3526 primer->link = link;
3527 primer->file = file;
3528 primer->fd = fd;
3529 primer->id = id;
3530 return 0;
3531 }
3532
bpf_link_settle(struct bpf_link_primer * primer)3533 int bpf_link_settle(struct bpf_link_primer *primer)
3534 {
3535 /* make bpf_link fetchable by ID */
3536 spin_lock_bh(&link_idr_lock);
3537 primer->link->id = primer->id;
3538 spin_unlock_bh(&link_idr_lock);
3539 /* make bpf_link fetchable by FD */
3540 fd_install(primer->fd, primer->file);
3541 /* pass through installed FD */
3542 return primer->fd;
3543 }
3544
bpf_link_new_fd(struct bpf_link * link)3545 int bpf_link_new_fd(struct bpf_link *link)
3546 {
3547 return anon_inode_getfd("bpf-link",
3548 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3549 link, O_CLOEXEC);
3550 }
3551
bpf_link_get_from_fd(u32 ufd)3552 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3553 {
3554 CLASS(fd, f)(ufd);
3555 struct bpf_link *link;
3556
3557 if (fd_empty(f))
3558 return ERR_PTR(-EBADF);
3559 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3560 return ERR_PTR(-EINVAL);
3561
3562 link = fd_file(f)->private_data;
3563 bpf_link_inc(link);
3564 return link;
3565 }
3566 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL");
3567
bpf_tracing_link_release(struct bpf_link * link)3568 static void bpf_tracing_link_release(struct bpf_link *link)
3569 {
3570 struct bpf_tracing_link *tr_link =
3571 container_of(link, struct bpf_tracing_link, link.link);
3572 int err;
3573
3574 err = bpf_trampoline_unlink_prog(&tr_link->link.node,
3575 tr_link->trampoline,
3576 tr_link->tgt_prog);
3577 WARN_ONCE(err, "bpf_trampoline_unlink_prog failed: %d\n", err);
3578
3579 bpf_trampoline_put(tr_link->trampoline);
3580
3581 /* tgt_prog is NULL if target is a kernel function */
3582 if (tr_link->tgt_prog)
3583 bpf_prog_put(tr_link->tgt_prog);
3584 }
3585
bpf_tracing_link_dealloc(struct bpf_link * link)3586 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3587 {
3588 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link);
3589
3590 kfree(tr_link);
3591 }
3592
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3593 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3594 struct seq_file *seq)
3595 {
3596 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link);
3597
3598 u32 target_btf_id, target_obj_id;
3599
3600 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3601 &target_obj_id, &target_btf_id);
3602 seq_printf(seq,
3603 "attach_type:\t%d\n"
3604 "target_obj_id:\t%u\n"
3605 "target_btf_id:\t%u\n"
3606 "cookie:\t%llu\n",
3607 link->attach_type,
3608 target_obj_id,
3609 target_btf_id,
3610 tr_link->link.node.cookie);
3611 }
3612
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3613 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3614 struct bpf_link_info *info)
3615 {
3616 struct bpf_tracing_link *tr_link = container_of(link, struct bpf_tracing_link, link.link);
3617
3618 info->tracing.attach_type = link->attach_type;
3619 info->tracing.cookie = tr_link->link.node.cookie;
3620 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3621 &info->tracing.target_obj_id,
3622 &info->tracing.target_btf_id);
3623
3624 return 0;
3625 }
3626
3627 static const struct bpf_link_ops bpf_tracing_link_lops = {
3628 .release = bpf_tracing_link_release,
3629 .dealloc = bpf_tracing_link_dealloc,
3630 .show_fdinfo = bpf_tracing_link_show_fdinfo,
3631 .fill_link_info = bpf_tracing_link_fill_link_info,
3632 };
3633
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie,enum bpf_attach_type attach_type)3634 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3635 int tgt_prog_fd,
3636 u32 btf_id,
3637 u64 bpf_cookie,
3638 enum bpf_attach_type attach_type)
3639 {
3640 struct bpf_link_primer link_primer;
3641 struct bpf_prog *tgt_prog = NULL;
3642 struct bpf_trampoline *tr = NULL;
3643 struct bpf_tracing_link *link;
3644 u64 key = 0;
3645 int err;
3646
3647 switch (prog->type) {
3648 case BPF_PROG_TYPE_TRACING:
3649 if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3650 prog->expected_attach_type != BPF_TRACE_FEXIT &&
3651 prog->expected_attach_type != BPF_TRACE_FSESSION &&
3652 prog->expected_attach_type != BPF_MODIFY_RETURN) {
3653 err = -EINVAL;
3654 goto out_put_prog;
3655 }
3656 break;
3657 case BPF_PROG_TYPE_EXT:
3658 if (prog->expected_attach_type != 0) {
3659 err = -EINVAL;
3660 goto out_put_prog;
3661 }
3662 break;
3663 case BPF_PROG_TYPE_LSM:
3664 if (prog->expected_attach_type != BPF_LSM_MAC) {
3665 err = -EINVAL;
3666 goto out_put_prog;
3667 }
3668 break;
3669 default:
3670 err = -EINVAL;
3671 goto out_put_prog;
3672 }
3673
3674 if (!!tgt_prog_fd != !!btf_id) {
3675 err = -EINVAL;
3676 goto out_put_prog;
3677 }
3678
3679 if (tgt_prog_fd) {
3680 /*
3681 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3682 * part would be changed to implement the same for
3683 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3684 * attach_tracing_prog flag is set.
3685 */
3686 if (prog->type != BPF_PROG_TYPE_EXT) {
3687 err = -EINVAL;
3688 goto out_put_prog;
3689 }
3690
3691 tgt_prog = bpf_prog_get(tgt_prog_fd);
3692 if (IS_ERR(tgt_prog)) {
3693 err = PTR_ERR(tgt_prog);
3694 tgt_prog = NULL;
3695 goto out_put_prog;
3696 }
3697
3698 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3699 }
3700
3701 link = kzalloc_obj(*link, GFP_USER);
3702 if (!link) {
3703 err = -ENOMEM;
3704 goto out_put_prog;
3705 }
3706 bpf_tramp_link_init(&link->link, BPF_LINK_TYPE_TRACING,
3707 &bpf_tracing_link_lops, prog, attach_type, bpf_cookie);
3708
3709 if (prog->expected_attach_type == BPF_TRACE_FSESSION) {
3710 link->fexit.link = &link->link.link;
3711 link->fexit.cookie = bpf_cookie;
3712 }
3713
3714 mutex_lock(&prog->aux->dst_mutex);
3715
3716 /* There are a few possible cases here:
3717 *
3718 * - if prog->aux->dst_trampoline is set, the program was just loaded
3719 * and not yet attached to anything, so we can use the values stored
3720 * in prog->aux
3721 *
3722 * - if prog->aux->dst_trampoline is NULL, the program has already been
3723 * attached to a target and its initial target was cleared (below)
3724 *
3725 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3726 * target_btf_id using the link_create API.
3727 *
3728 * - if tgt_prog == NULL when this function was called using the old
3729 * raw_tracepoint_open API, and we need a target from prog->aux
3730 *
3731 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3732 * was detached and is going for re-attachment.
3733 *
3734 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3735 * are NULL, then program was already attached and user did not provide
3736 * tgt_prog_fd so we have no way to find out or create trampoline
3737 */
3738 if (!prog->aux->dst_trampoline && !tgt_prog) {
3739 /*
3740 * Allow re-attach for TRACING and LSM programs. If it's
3741 * currently linked, bpf_trampoline_link_prog will fail.
3742 * EXT programs need to specify tgt_prog_fd, so they
3743 * re-attach in separate code path.
3744 */
3745 if (prog->type != BPF_PROG_TYPE_TRACING &&
3746 prog->type != BPF_PROG_TYPE_LSM) {
3747 err = -EINVAL;
3748 goto out_unlock;
3749 }
3750 /* We can allow re-attach only if we have valid attach_btf. */
3751 if (!prog->aux->attach_btf) {
3752 err = -EINVAL;
3753 goto out_unlock;
3754 }
3755 btf_id = prog->aux->attach_btf_id;
3756 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3757 }
3758
3759 if (!prog->aux->dst_trampoline ||
3760 (key && key != prog->aux->dst_trampoline->key)) {
3761 /* If there is no saved target, or the specified target is
3762 * different from the destination specified at load time, we
3763 * need a new trampoline and a check for compatibility
3764 */
3765 struct bpf_attach_target_info tgt_info = {};
3766
3767 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3768 &tgt_info);
3769 if (err)
3770 goto out_unlock;
3771
3772 if (tgt_info.tgt_mod) {
3773 module_put(prog->aux->mod);
3774 prog->aux->mod = tgt_info.tgt_mod;
3775 }
3776
3777 tr = bpf_trampoline_get(key, &tgt_info);
3778 if (!tr) {
3779 err = -ENOMEM;
3780 goto out_unlock;
3781 }
3782 } else {
3783 /* The caller didn't specify a target, or the target was the
3784 * same as the destination supplied during program load. This
3785 * means we can reuse the trampoline and reference from program
3786 * load time, and there is no need to allocate a new one. This
3787 * can only happen once for any program, as the saved values in
3788 * prog->aux are cleared below.
3789 */
3790 tr = prog->aux->dst_trampoline;
3791 tgt_prog = prog->aux->dst_prog;
3792 }
3793 /*
3794 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true
3795 * freplace prog. Without this check, kprobe_write_ctx=true freplace
3796 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and
3797 * then modify the registers of the kprobe prog's target kernel
3798 * function.
3799 *
3800 * This also blocks the combination of uprobe+freplace, because it is
3801 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe
3802 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by
3803 * the target perf event flags in __perf_event_set_bpf_prog().
3804 */
3805 if (prog->type == BPF_PROG_TYPE_EXT &&
3806 prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) {
3807 err = -EINVAL;
3808 goto out_unlock;
3809 }
3810
3811 err = bpf_link_prime(&link->link.link, &link_primer);
3812 if (err)
3813 goto out_unlock;
3814
3815 err = bpf_trampoline_link_prog(&link->link.node, tr, tgt_prog);
3816 if (err) {
3817 bpf_link_cleanup(&link_primer);
3818 link = NULL;
3819 goto out_unlock;
3820 }
3821
3822 link->tgt_prog = tgt_prog;
3823 link->trampoline = tr;
3824
3825 /* Always clear the trampoline and target prog from prog->aux to make
3826 * sure the original attach destination is not kept alive after a
3827 * program is (re-)attached to another target.
3828 */
3829 if (prog->aux->dst_prog &&
3830 (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3831 /* got extra prog ref from syscall, or attaching to different prog */
3832 bpf_prog_put(prog->aux->dst_prog);
3833 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3834 /* we allocated a new trampoline, so free the old one */
3835 bpf_trampoline_put(prog->aux->dst_trampoline);
3836
3837 prog->aux->dst_prog = NULL;
3838 prog->aux->dst_trampoline = NULL;
3839 mutex_unlock(&prog->aux->dst_mutex);
3840
3841 return bpf_link_settle(&link_primer);
3842 out_unlock:
3843 if (tr && tr != prog->aux->dst_trampoline)
3844 bpf_trampoline_put(tr);
3845 mutex_unlock(&prog->aux->dst_mutex);
3846 kfree(link);
3847 out_put_prog:
3848 if (tgt_prog_fd && tgt_prog)
3849 bpf_prog_put(tgt_prog);
3850 return err;
3851 }
3852
bpf_raw_tp_link_release(struct bpf_link * link)3853 static void bpf_raw_tp_link_release(struct bpf_link *link)
3854 {
3855 struct bpf_raw_tp_link *raw_tp =
3856 container_of(link, struct bpf_raw_tp_link, link);
3857
3858 bpf_probe_unregister(raw_tp->btp, raw_tp);
3859 bpf_put_raw_tracepoint(raw_tp->btp);
3860 }
3861
bpf_raw_tp_link_dealloc(struct bpf_link * link)3862 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3863 {
3864 struct bpf_raw_tp_link *raw_tp =
3865 container_of(link, struct bpf_raw_tp_link, link);
3866
3867 kfree(raw_tp);
3868 }
3869
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3870 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3871 struct seq_file *seq)
3872 {
3873 struct bpf_raw_tp_link *raw_tp_link =
3874 container_of(link, struct bpf_raw_tp_link, link);
3875
3876 seq_printf(seq,
3877 "tp_name:\t%s\n"
3878 "cookie:\t%llu\n",
3879 raw_tp_link->btp->tp->name,
3880 raw_tp_link->cookie);
3881 }
3882
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3883 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3884 u32 len)
3885 {
3886 if (ulen >= len + 1) {
3887 if (copy_to_user(ubuf, buf, len + 1))
3888 return -EFAULT;
3889 } else {
3890 char zero = '\0';
3891
3892 if (copy_to_user(ubuf, buf, ulen - 1))
3893 return -EFAULT;
3894 if (put_user(zero, ubuf + ulen - 1))
3895 return -EFAULT;
3896 return -ENOSPC;
3897 }
3898
3899 return 0;
3900 }
3901
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3902 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3903 struct bpf_link_info *info)
3904 {
3905 struct bpf_raw_tp_link *raw_tp_link =
3906 container_of(link, struct bpf_raw_tp_link, link);
3907 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3908 const char *tp_name = raw_tp_link->btp->tp->name;
3909 u32 ulen = info->raw_tracepoint.tp_name_len;
3910 size_t tp_len = strlen(tp_name);
3911
3912 if (!ulen ^ !ubuf)
3913 return -EINVAL;
3914
3915 info->raw_tracepoint.tp_name_len = tp_len + 1;
3916 info->raw_tracepoint.cookie = raw_tp_link->cookie;
3917
3918 if (!ubuf)
3919 return 0;
3920
3921 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3922 }
3923
3924 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3925 .release = bpf_raw_tp_link_release,
3926 .dealloc_deferred = bpf_raw_tp_link_dealloc,
3927 .show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3928 .fill_link_info = bpf_raw_tp_link_fill_link_info,
3929 };
3930
3931 #ifdef CONFIG_PERF_EVENTS
3932 struct bpf_perf_link {
3933 struct bpf_link link;
3934 struct file *perf_file;
3935 };
3936
bpf_perf_link_release(struct bpf_link * link)3937 static void bpf_perf_link_release(struct bpf_link *link)
3938 {
3939 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3940 struct perf_event *event = perf_link->perf_file->private_data;
3941
3942 perf_event_free_bpf_prog(event);
3943 fput(perf_link->perf_file);
3944 }
3945
bpf_perf_link_dealloc(struct bpf_link * link)3946 static void bpf_perf_link_dealloc(struct bpf_link *link)
3947 {
3948 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3949
3950 kfree(perf_link);
3951 }
3952
bpf_perf_link_fill_common(const struct perf_event * event,char __user * uname,u32 * ulenp,u64 * probe_offset,u64 * probe_addr,u32 * fd_type,unsigned long * missed)3953 static int bpf_perf_link_fill_common(const struct perf_event *event,
3954 char __user *uname, u32 *ulenp,
3955 u64 *probe_offset, u64 *probe_addr,
3956 u32 *fd_type, unsigned long *missed)
3957 {
3958 const char *buf;
3959 u32 prog_id, ulen;
3960 size_t len;
3961 int err;
3962
3963 ulen = *ulenp;
3964 if (!ulen ^ !uname)
3965 return -EINVAL;
3966
3967 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3968 probe_offset, probe_addr, missed);
3969 if (err)
3970 return err;
3971
3972 if (buf) {
3973 len = strlen(buf);
3974 *ulenp = len + 1;
3975 } else {
3976 *ulenp = 1;
3977 }
3978 if (!uname)
3979 return 0;
3980
3981 if (buf) {
3982 err = bpf_copy_to_user(uname, buf, ulen, len);
3983 if (err)
3984 return err;
3985 } else {
3986 char zero = '\0';
3987
3988 if (put_user(zero, uname))
3989 return -EFAULT;
3990 }
3991 return 0;
3992 }
3993
3994 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3995 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3996 struct bpf_link_info *info)
3997 {
3998 unsigned long missed;
3999 char __user *uname;
4000 u64 addr, offset;
4001 u32 ulen, type;
4002 int err;
4003
4004 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
4005 ulen = info->perf_event.kprobe.name_len;
4006 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
4007 &type, &missed);
4008 if (err)
4009 return err;
4010 if (type == BPF_FD_TYPE_KRETPROBE)
4011 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
4012 else
4013 info->perf_event.type = BPF_PERF_EVENT_KPROBE;
4014 info->perf_event.kprobe.name_len = ulen;
4015 info->perf_event.kprobe.offset = offset;
4016 info->perf_event.kprobe.missed = missed;
4017 if (!kallsyms_show_value(current_cred()))
4018 addr = 0;
4019 info->perf_event.kprobe.addr = addr;
4020 info->perf_event.kprobe.cookie = event->bpf_cookie;
4021 return 0;
4022 }
4023
bpf_perf_link_fdinfo_kprobe(const struct perf_event * event,struct seq_file * seq)4024 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event,
4025 struct seq_file *seq)
4026 {
4027 const char *name;
4028 int err;
4029 u32 prog_id, type;
4030 u64 offset, addr;
4031 unsigned long missed;
4032
4033 err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
4034 &offset, &addr, &missed);
4035 if (err)
4036 return;
4037
4038 seq_printf(seq,
4039 "name:\t%s\n"
4040 "offset:\t%#llx\n"
4041 "missed:\t%lu\n"
4042 "addr:\t%#llx\n"
4043 "event_type:\t%s\n"
4044 "cookie:\t%llu\n",
4045 name, offset, missed, addr,
4046 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe",
4047 event->bpf_cookie);
4048 }
4049 #endif
4050
4051 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)4052 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
4053 struct bpf_link_info *info)
4054 {
4055 u64 ref_ctr_offset, offset;
4056 char __user *uname;
4057 u32 ulen, type;
4058 int err;
4059
4060 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
4061 ulen = info->perf_event.uprobe.name_len;
4062 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset,
4063 &type, NULL);
4064 if (err)
4065 return err;
4066
4067 if (type == BPF_FD_TYPE_URETPROBE)
4068 info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
4069 else
4070 info->perf_event.type = BPF_PERF_EVENT_UPROBE;
4071 info->perf_event.uprobe.name_len = ulen;
4072 info->perf_event.uprobe.offset = offset;
4073 info->perf_event.uprobe.cookie = event->bpf_cookie;
4074 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset;
4075 return 0;
4076 }
4077
bpf_perf_link_fdinfo_uprobe(const struct perf_event * event,struct seq_file * seq)4078 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event,
4079 struct seq_file *seq)
4080 {
4081 const char *name;
4082 int err;
4083 u32 prog_id, type;
4084 u64 offset, ref_ctr_offset;
4085 unsigned long missed;
4086
4087 err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
4088 &offset, &ref_ctr_offset, &missed);
4089 if (err)
4090 return;
4091
4092 seq_printf(seq,
4093 "name:\t%s\n"
4094 "offset:\t%#llx\n"
4095 "ref_ctr_offset:\t%#llx\n"
4096 "event_type:\t%s\n"
4097 "cookie:\t%llu\n",
4098 name, offset, ref_ctr_offset,
4099 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe",
4100 event->bpf_cookie);
4101 }
4102 #endif
4103
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)4104 static int bpf_perf_link_fill_probe(const struct perf_event *event,
4105 struct bpf_link_info *info)
4106 {
4107 #ifdef CONFIG_KPROBE_EVENTS
4108 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4109 return bpf_perf_link_fill_kprobe(event, info);
4110 #endif
4111 #ifdef CONFIG_UPROBE_EVENTS
4112 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4113 return bpf_perf_link_fill_uprobe(event, info);
4114 #endif
4115 return -EOPNOTSUPP;
4116 }
4117
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)4118 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
4119 struct bpf_link_info *info)
4120 {
4121 char __user *uname;
4122 u32 ulen;
4123 int err;
4124
4125 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
4126 ulen = info->perf_event.tracepoint.name_len;
4127 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
4128 if (err)
4129 return err;
4130
4131 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
4132 info->perf_event.tracepoint.name_len = ulen;
4133 info->perf_event.tracepoint.cookie = event->bpf_cookie;
4134 return 0;
4135 }
4136
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)4137 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
4138 struct bpf_link_info *info)
4139 {
4140 info->perf_event.event.type = event->attr.type;
4141 info->perf_event.event.config = event->attr.config;
4142 info->perf_event.event.cookie = event->bpf_cookie;
4143 info->perf_event.type = BPF_PERF_EVENT_EVENT;
4144 return 0;
4145 }
4146
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)4147 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
4148 struct bpf_link_info *info)
4149 {
4150 struct bpf_perf_link *perf_link;
4151 const struct perf_event *event;
4152
4153 perf_link = container_of(link, struct bpf_perf_link, link);
4154 event = perf_get_event(perf_link->perf_file);
4155 if (IS_ERR(event))
4156 return PTR_ERR(event);
4157
4158 switch (event->prog->type) {
4159 case BPF_PROG_TYPE_PERF_EVENT:
4160 return bpf_perf_link_fill_perf_event(event, info);
4161 case BPF_PROG_TYPE_TRACEPOINT:
4162 return bpf_perf_link_fill_tracepoint(event, info);
4163 case BPF_PROG_TYPE_KPROBE:
4164 return bpf_perf_link_fill_probe(event, info);
4165 default:
4166 return -EOPNOTSUPP;
4167 }
4168 }
4169
bpf_perf_event_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4170 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event,
4171 struct seq_file *seq)
4172 {
4173 seq_printf(seq,
4174 "type:\t%u\n"
4175 "config:\t%llu\n"
4176 "event_type:\t%s\n"
4177 "cookie:\t%llu\n",
4178 event->attr.type, event->attr.config,
4179 "event", event->bpf_cookie);
4180 }
4181
bpf_tracepoint_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4182 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event,
4183 struct seq_file *seq)
4184 {
4185 int err;
4186 const char *name;
4187 u32 prog_id;
4188
4189 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL,
4190 NULL, NULL);
4191 if (err)
4192 return;
4193
4194 seq_printf(seq,
4195 "tp_name:\t%s\n"
4196 "event_type:\t%s\n"
4197 "cookie:\t%llu\n",
4198 name, "tracepoint", event->bpf_cookie);
4199 }
4200
bpf_probe_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4201 static void bpf_probe_link_show_fdinfo(const struct perf_event *event,
4202 struct seq_file *seq)
4203 {
4204 #ifdef CONFIG_KPROBE_EVENTS
4205 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4206 return bpf_perf_link_fdinfo_kprobe(event, seq);
4207 #endif
4208
4209 #ifdef CONFIG_UPROBE_EVENTS
4210 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4211 return bpf_perf_link_fdinfo_uprobe(event, seq);
4212 #endif
4213 }
4214
bpf_perf_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)4215 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link,
4216 struct seq_file *seq)
4217 {
4218 struct bpf_perf_link *perf_link;
4219 const struct perf_event *event;
4220
4221 perf_link = container_of(link, struct bpf_perf_link, link);
4222 event = perf_get_event(perf_link->perf_file);
4223 if (IS_ERR(event))
4224 return;
4225
4226 switch (event->prog->type) {
4227 case BPF_PROG_TYPE_PERF_EVENT:
4228 return bpf_perf_event_link_show_fdinfo(event, seq);
4229 case BPF_PROG_TYPE_TRACEPOINT:
4230 return bpf_tracepoint_link_show_fdinfo(event, seq);
4231 case BPF_PROG_TYPE_KPROBE:
4232 return bpf_probe_link_show_fdinfo(event, seq);
4233 default:
4234 return;
4235 }
4236 }
4237
4238 static const struct bpf_link_ops bpf_perf_link_lops = {
4239 .release = bpf_perf_link_release,
4240 .dealloc = bpf_perf_link_dealloc,
4241 .fill_link_info = bpf_perf_link_fill_link_info,
4242 .show_fdinfo = bpf_perf_link_show_fdinfo,
4243 };
4244
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4245 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4246 {
4247 struct bpf_link_primer link_primer;
4248 struct bpf_perf_link *link;
4249 struct perf_event *event;
4250 struct file *perf_file;
4251 int err;
4252
4253 if (attr->link_create.flags)
4254 return -EINVAL;
4255
4256 perf_file = perf_event_get(attr->link_create.target_fd);
4257 if (IS_ERR(perf_file))
4258 return PTR_ERR(perf_file);
4259
4260 link = kzalloc_obj(*link, GFP_USER);
4261 if (!link) {
4262 err = -ENOMEM;
4263 goto out_put_file;
4264 }
4265 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog,
4266 attr->link_create.attach_type);
4267 link->perf_file = perf_file;
4268
4269 err = bpf_link_prime(&link->link, &link_primer);
4270 if (err) {
4271 kfree(link);
4272 goto out_put_file;
4273 }
4274
4275 event = perf_file->private_data;
4276 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
4277 if (err) {
4278 bpf_link_cleanup(&link_primer);
4279 goto out_put_file;
4280 }
4281 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
4282 bpf_prog_inc(prog);
4283
4284 return bpf_link_settle(&link_primer);
4285
4286 out_put_file:
4287 fput(perf_file);
4288 return err;
4289 }
4290 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4291 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4292 {
4293 return -EOPNOTSUPP;
4294 }
4295 #endif /* CONFIG_PERF_EVENTS */
4296
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie,enum bpf_attach_type attach_type)4297 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
4298 const char __user *user_tp_name, u64 cookie,
4299 enum bpf_attach_type attach_type)
4300 {
4301 struct bpf_link_primer link_primer;
4302 struct bpf_raw_tp_link *link;
4303 struct bpf_raw_event_map *btp;
4304 const char *tp_name;
4305 char buf[128];
4306 int err;
4307
4308 switch (prog->type) {
4309 case BPF_PROG_TYPE_TRACING:
4310 case BPF_PROG_TYPE_EXT:
4311 case BPF_PROG_TYPE_LSM:
4312 if (user_tp_name)
4313 /* The attach point for this category of programs
4314 * should be specified via btf_id during program load.
4315 */
4316 return -EINVAL;
4317 if (prog->type == BPF_PROG_TYPE_TRACING &&
4318 prog->expected_attach_type == BPF_TRACE_RAW_TP) {
4319 tp_name = prog->aux->attach_func_name;
4320 break;
4321 }
4322 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type);
4323 case BPF_PROG_TYPE_RAW_TRACEPOINT:
4324 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
4325 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
4326 return -EFAULT;
4327 buf[sizeof(buf) - 1] = 0;
4328 tp_name = buf;
4329 break;
4330 default:
4331 return -EINVAL;
4332 }
4333
4334 btp = bpf_get_raw_tracepoint(tp_name);
4335 if (!btp)
4336 return -ENOENT;
4337
4338 if (prog->sleepable && !tracepoint_is_faultable(btp->tp)) {
4339 bpf_put_raw_tracepoint(btp);
4340 return -EINVAL;
4341 }
4342
4343 link = kzalloc_obj(*link, GFP_USER);
4344 if (!link) {
4345 err = -ENOMEM;
4346 goto out_put_btp;
4347 }
4348 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
4349 &bpf_raw_tp_link_lops, prog, attach_type,
4350 tracepoint_is_faultable(btp->tp));
4351 link->btp = btp;
4352 link->cookie = cookie;
4353
4354 err = bpf_link_prime(&link->link, &link_primer);
4355 if (err) {
4356 kfree(link);
4357 goto out_put_btp;
4358 }
4359
4360 err = bpf_probe_register(link->btp, link);
4361 if (err) {
4362 bpf_link_cleanup(&link_primer);
4363 goto out_put_btp;
4364 }
4365
4366 return bpf_link_settle(&link_primer);
4367
4368 out_put_btp:
4369 bpf_put_raw_tracepoint(btp);
4370 return err;
4371 }
4372
4373 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4374
bpf_raw_tracepoint_open(const union bpf_attr * attr)4375 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4376 {
4377 struct bpf_prog *prog;
4378 void __user *tp_name;
4379 __u64 cookie;
4380 int fd;
4381
4382 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4383 return -EINVAL;
4384
4385 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4386 if (IS_ERR(prog))
4387 return PTR_ERR(prog);
4388
4389 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4390 cookie = attr->raw_tracepoint.cookie;
4391 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type);
4392 if (fd < 0)
4393 bpf_prog_put(prog);
4394 return fd;
4395 }
4396
4397 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4398 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4399 {
4400 switch (attach_type) {
4401 case BPF_CGROUP_INET_INGRESS:
4402 case BPF_CGROUP_INET_EGRESS:
4403 return BPF_PROG_TYPE_CGROUP_SKB;
4404 case BPF_CGROUP_INET_SOCK_CREATE:
4405 case BPF_CGROUP_INET_SOCK_RELEASE:
4406 case BPF_CGROUP_INET4_POST_BIND:
4407 case BPF_CGROUP_INET6_POST_BIND:
4408 return BPF_PROG_TYPE_CGROUP_SOCK;
4409 case BPF_CGROUP_INET4_BIND:
4410 case BPF_CGROUP_INET6_BIND:
4411 case BPF_CGROUP_INET4_CONNECT:
4412 case BPF_CGROUP_INET6_CONNECT:
4413 case BPF_CGROUP_UNIX_CONNECT:
4414 case BPF_CGROUP_INET4_GETPEERNAME:
4415 case BPF_CGROUP_INET6_GETPEERNAME:
4416 case BPF_CGROUP_UNIX_GETPEERNAME:
4417 case BPF_CGROUP_INET4_GETSOCKNAME:
4418 case BPF_CGROUP_INET6_GETSOCKNAME:
4419 case BPF_CGROUP_UNIX_GETSOCKNAME:
4420 case BPF_CGROUP_UDP4_SENDMSG:
4421 case BPF_CGROUP_UDP6_SENDMSG:
4422 case BPF_CGROUP_UNIX_SENDMSG:
4423 case BPF_CGROUP_UDP4_RECVMSG:
4424 case BPF_CGROUP_UDP6_RECVMSG:
4425 case BPF_CGROUP_UNIX_RECVMSG:
4426 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4427 case BPF_CGROUP_SOCK_OPS:
4428 return BPF_PROG_TYPE_SOCK_OPS;
4429 case BPF_CGROUP_DEVICE:
4430 return BPF_PROG_TYPE_CGROUP_DEVICE;
4431 case BPF_SK_MSG_VERDICT:
4432 return BPF_PROG_TYPE_SK_MSG;
4433 case BPF_SK_SKB_STREAM_PARSER:
4434 case BPF_SK_SKB_STREAM_VERDICT:
4435 case BPF_SK_SKB_VERDICT:
4436 return BPF_PROG_TYPE_SK_SKB;
4437 case BPF_LIRC_MODE2:
4438 return BPF_PROG_TYPE_LIRC_MODE2;
4439 case BPF_FLOW_DISSECTOR:
4440 return BPF_PROG_TYPE_FLOW_DISSECTOR;
4441 case BPF_CGROUP_SYSCTL:
4442 return BPF_PROG_TYPE_CGROUP_SYSCTL;
4443 case BPF_CGROUP_GETSOCKOPT:
4444 case BPF_CGROUP_SETSOCKOPT:
4445 return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4446 case BPF_TRACE_ITER:
4447 case BPF_TRACE_RAW_TP:
4448 case BPF_TRACE_FENTRY:
4449 case BPF_TRACE_FEXIT:
4450 case BPF_TRACE_FSESSION:
4451 case BPF_TRACE_FSESSION_MULTI:
4452 case BPF_TRACE_FENTRY_MULTI:
4453 case BPF_TRACE_FEXIT_MULTI:
4454 case BPF_MODIFY_RETURN:
4455 return BPF_PROG_TYPE_TRACING;
4456 case BPF_LSM_MAC:
4457 return BPF_PROG_TYPE_LSM;
4458 case BPF_SK_LOOKUP:
4459 return BPF_PROG_TYPE_SK_LOOKUP;
4460 case BPF_XDP:
4461 return BPF_PROG_TYPE_XDP;
4462 case BPF_LSM_CGROUP:
4463 return BPF_PROG_TYPE_LSM;
4464 case BPF_TCX_INGRESS:
4465 case BPF_TCX_EGRESS:
4466 case BPF_NETKIT_PRIMARY:
4467 case BPF_NETKIT_PEER:
4468 return BPF_PROG_TYPE_SCHED_CLS;
4469 default:
4470 return BPF_PROG_TYPE_UNSPEC;
4471 }
4472 }
4473
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4474 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4475 enum bpf_attach_type attach_type)
4476 {
4477 enum bpf_prog_type ptype;
4478
4479 switch (prog->type) {
4480 case BPF_PROG_TYPE_CGROUP_SOCK:
4481 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4482 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4483 case BPF_PROG_TYPE_SK_LOOKUP:
4484 return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4485 case BPF_PROG_TYPE_CGROUP_SKB:
4486 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4487 /* cg-skb progs can be loaded by unpriv user.
4488 * check permissions at attach time.
4489 */
4490 return -EPERM;
4491
4492 ptype = attach_type_to_prog_type(attach_type);
4493 if (prog->type != ptype)
4494 return -EINVAL;
4495
4496 return prog->enforce_expected_attach_type &&
4497 prog->expected_attach_type != attach_type ?
4498 -EINVAL : 0;
4499 case BPF_PROG_TYPE_EXT:
4500 return 0;
4501 case BPF_PROG_TYPE_NETFILTER:
4502 if (attach_type != BPF_NETFILTER)
4503 return -EINVAL;
4504 return 0;
4505 case BPF_PROG_TYPE_PERF_EVENT:
4506 case BPF_PROG_TYPE_TRACEPOINT:
4507 if (attach_type != BPF_PERF_EVENT)
4508 return -EINVAL;
4509 return 0;
4510 case BPF_PROG_TYPE_KPROBE:
4511 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4512 attach_type != BPF_TRACE_KPROBE_MULTI)
4513 return -EINVAL;
4514 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4515 attach_type != BPF_TRACE_KPROBE_SESSION)
4516 return -EINVAL;
4517 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4518 attach_type != BPF_TRACE_UPROBE_MULTI)
4519 return -EINVAL;
4520 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4521 attach_type != BPF_TRACE_UPROBE_SESSION)
4522 return -EINVAL;
4523 if (attach_type != BPF_PERF_EVENT &&
4524 attach_type != BPF_TRACE_KPROBE_MULTI &&
4525 attach_type != BPF_TRACE_KPROBE_SESSION &&
4526 attach_type != BPF_TRACE_UPROBE_MULTI &&
4527 attach_type != BPF_TRACE_UPROBE_SESSION)
4528 return -EINVAL;
4529 return 0;
4530 case BPF_PROG_TYPE_SCHED_CLS:
4531 if (attach_type != BPF_TCX_INGRESS &&
4532 attach_type != BPF_TCX_EGRESS &&
4533 attach_type != BPF_NETKIT_PRIMARY &&
4534 attach_type != BPF_NETKIT_PEER)
4535 return -EINVAL;
4536 return 0;
4537 default:
4538 ptype = attach_type_to_prog_type(attach_type);
4539 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4540 return -EINVAL;
4541 return 0;
4542 }
4543 }
4544
is_cgroup_prog_type(enum bpf_prog_type ptype,enum bpf_attach_type atype,bool check_atype)4545 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype,
4546 bool check_atype)
4547 {
4548 switch (ptype) {
4549 case BPF_PROG_TYPE_CGROUP_DEVICE:
4550 case BPF_PROG_TYPE_CGROUP_SKB:
4551 case BPF_PROG_TYPE_CGROUP_SOCK:
4552 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4553 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4554 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4555 case BPF_PROG_TYPE_SOCK_OPS:
4556 return true;
4557 case BPF_PROG_TYPE_LSM:
4558 return check_atype ? atype == BPF_LSM_CGROUP : true;
4559 default:
4560 return false;
4561 }
4562 }
4563
4564 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4565
4566 #define BPF_F_ATTACH_MASK_BASE \
4567 (BPF_F_ALLOW_OVERRIDE | \
4568 BPF_F_ALLOW_MULTI | \
4569 BPF_F_REPLACE | \
4570 BPF_F_PREORDER)
4571
4572 #define BPF_F_ATTACH_MASK_MPROG \
4573 (BPF_F_REPLACE | \
4574 BPF_F_BEFORE | \
4575 BPF_F_AFTER | \
4576 BPF_F_ID | \
4577 BPF_F_LINK)
4578
bpf_prog_attach(const union bpf_attr * attr)4579 static int bpf_prog_attach(const union bpf_attr *attr)
4580 {
4581 enum bpf_prog_type ptype;
4582 struct bpf_prog *prog;
4583 int ret;
4584
4585 if (CHECK_ATTR(BPF_PROG_ATTACH))
4586 return -EINVAL;
4587
4588 ptype = attach_type_to_prog_type(attr->attach_type);
4589 if (ptype == BPF_PROG_TYPE_UNSPEC)
4590 return -EINVAL;
4591 if (bpf_mprog_supported(ptype)) {
4592 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4593 return -EINVAL;
4594 } else if (is_cgroup_prog_type(ptype, 0, false)) {
4595 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG))
4596 return -EINVAL;
4597 } else {
4598 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4599 return -EINVAL;
4600 if (attr->relative_fd ||
4601 attr->expected_revision)
4602 return -EINVAL;
4603 }
4604
4605 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4606 if (IS_ERR(prog))
4607 return PTR_ERR(prog);
4608
4609 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4610 bpf_prog_put(prog);
4611 return -EINVAL;
4612 }
4613
4614 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) {
4615 ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4616 goto out;
4617 }
4618
4619 switch (ptype) {
4620 case BPF_PROG_TYPE_SK_SKB:
4621 case BPF_PROG_TYPE_SK_MSG:
4622 ret = sock_map_get_from_fd(attr, prog);
4623 break;
4624 case BPF_PROG_TYPE_LIRC_MODE2:
4625 ret = lirc_prog_attach(attr, prog);
4626 break;
4627 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4628 ret = netns_bpf_prog_attach(attr, prog);
4629 break;
4630 case BPF_PROG_TYPE_SCHED_CLS:
4631 if (attr->attach_type == BPF_TCX_INGRESS ||
4632 attr->attach_type == BPF_TCX_EGRESS)
4633 ret = tcx_prog_attach(attr, prog);
4634 else
4635 ret = netkit_prog_attach(attr, prog);
4636 break;
4637 default:
4638 ret = -EINVAL;
4639 }
4640 out:
4641 if (ret)
4642 bpf_prog_put(prog);
4643 return ret;
4644 }
4645
4646 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4647
bpf_prog_detach(const union bpf_attr * attr)4648 static int bpf_prog_detach(const union bpf_attr *attr)
4649 {
4650 struct bpf_prog *prog = NULL;
4651 enum bpf_prog_type ptype;
4652 int ret;
4653
4654 if (CHECK_ATTR(BPF_PROG_DETACH))
4655 return -EINVAL;
4656
4657 ptype = attach_type_to_prog_type(attr->attach_type);
4658 if (bpf_mprog_supported(ptype)) {
4659 if (ptype == BPF_PROG_TYPE_UNSPEC)
4660 return -EINVAL;
4661 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4662 return -EINVAL;
4663 if (attr->attach_bpf_fd) {
4664 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4665 if (IS_ERR(prog))
4666 return PTR_ERR(prog);
4667 } else if (!bpf_mprog_detach_empty(ptype)) {
4668 return -EPERM;
4669 }
4670 } else if (is_cgroup_prog_type(ptype, 0, false)) {
4671 if (attr->attach_flags || attr->relative_fd)
4672 return -EINVAL;
4673 } else if (attr->attach_flags ||
4674 attr->relative_fd ||
4675 attr->expected_revision) {
4676 return -EINVAL;
4677 }
4678
4679 switch (ptype) {
4680 case BPF_PROG_TYPE_SK_MSG:
4681 case BPF_PROG_TYPE_SK_SKB:
4682 ret = sock_map_prog_detach(attr, ptype);
4683 break;
4684 case BPF_PROG_TYPE_LIRC_MODE2:
4685 ret = lirc_prog_detach(attr);
4686 break;
4687 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4688 ret = netns_bpf_prog_detach(attr, ptype);
4689 break;
4690 case BPF_PROG_TYPE_CGROUP_DEVICE:
4691 case BPF_PROG_TYPE_CGROUP_SKB:
4692 case BPF_PROG_TYPE_CGROUP_SOCK:
4693 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4694 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4695 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4696 case BPF_PROG_TYPE_SOCK_OPS:
4697 case BPF_PROG_TYPE_LSM:
4698 ret = cgroup_bpf_prog_detach(attr, ptype);
4699 break;
4700 case BPF_PROG_TYPE_SCHED_CLS:
4701 if (attr->attach_type == BPF_TCX_INGRESS ||
4702 attr->attach_type == BPF_TCX_EGRESS)
4703 ret = tcx_prog_detach(attr, prog);
4704 else
4705 ret = netkit_prog_detach(attr, prog);
4706 break;
4707 default:
4708 ret = -EINVAL;
4709 }
4710
4711 if (prog)
4712 bpf_prog_put(prog);
4713 return ret;
4714 }
4715
4716 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4717
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr,u32 uattr_size)4718 static int bpf_prog_query(const union bpf_attr *attr,
4719 union bpf_attr __user *uattr, u32 uattr_size)
4720 {
4721 if (!bpf_net_capable())
4722 return -EPERM;
4723 if (CHECK_ATTR(BPF_PROG_QUERY))
4724 return -EINVAL;
4725 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4726 return -EINVAL;
4727
4728 switch (attr->query.attach_type) {
4729 case BPF_CGROUP_INET_INGRESS:
4730 case BPF_CGROUP_INET_EGRESS:
4731 case BPF_CGROUP_INET_SOCK_CREATE:
4732 case BPF_CGROUP_INET_SOCK_RELEASE:
4733 case BPF_CGROUP_INET4_BIND:
4734 case BPF_CGROUP_INET6_BIND:
4735 case BPF_CGROUP_INET4_POST_BIND:
4736 case BPF_CGROUP_INET6_POST_BIND:
4737 case BPF_CGROUP_INET4_CONNECT:
4738 case BPF_CGROUP_INET6_CONNECT:
4739 case BPF_CGROUP_UNIX_CONNECT:
4740 case BPF_CGROUP_INET4_GETPEERNAME:
4741 case BPF_CGROUP_INET6_GETPEERNAME:
4742 case BPF_CGROUP_UNIX_GETPEERNAME:
4743 case BPF_CGROUP_INET4_GETSOCKNAME:
4744 case BPF_CGROUP_INET6_GETSOCKNAME:
4745 case BPF_CGROUP_UNIX_GETSOCKNAME:
4746 case BPF_CGROUP_UDP4_SENDMSG:
4747 case BPF_CGROUP_UDP6_SENDMSG:
4748 case BPF_CGROUP_UNIX_SENDMSG:
4749 case BPF_CGROUP_UDP4_RECVMSG:
4750 case BPF_CGROUP_UDP6_RECVMSG:
4751 case BPF_CGROUP_UNIX_RECVMSG:
4752 case BPF_CGROUP_SOCK_OPS:
4753 case BPF_CGROUP_DEVICE:
4754 case BPF_CGROUP_SYSCTL:
4755 case BPF_CGROUP_GETSOCKOPT:
4756 case BPF_CGROUP_SETSOCKOPT:
4757 case BPF_LSM_CGROUP:
4758 return cgroup_bpf_prog_query(attr, uattr, uattr_size);
4759 case BPF_LIRC_MODE2:
4760 return lirc_prog_query(attr, uattr);
4761 case BPF_FLOW_DISSECTOR:
4762 case BPF_SK_LOOKUP:
4763 return netns_bpf_prog_query(attr, uattr);
4764 case BPF_SK_SKB_STREAM_PARSER:
4765 case BPF_SK_SKB_STREAM_VERDICT:
4766 case BPF_SK_MSG_VERDICT:
4767 case BPF_SK_SKB_VERDICT:
4768 return sock_map_bpf_prog_query(attr, uattr);
4769 case BPF_TCX_INGRESS:
4770 case BPF_TCX_EGRESS:
4771 return tcx_prog_query(attr, uattr);
4772 case BPF_NETKIT_PRIMARY:
4773 case BPF_NETKIT_PEER:
4774 return netkit_prog_query(attr, uattr);
4775 default:
4776 return -EINVAL;
4777 }
4778 }
4779
4780 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4781
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4782 static int bpf_prog_test_run(const union bpf_attr *attr,
4783 union bpf_attr __user *uattr)
4784 {
4785 struct bpf_prog *prog;
4786 int ret = -ENOTSUPP;
4787
4788 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4789 return -EINVAL;
4790
4791 if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4792 (!attr->test.ctx_size_in && attr->test.ctx_in))
4793 return -EINVAL;
4794
4795 if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4796 (!attr->test.ctx_size_out && attr->test.ctx_out))
4797 return -EINVAL;
4798
4799 prog = bpf_prog_get(attr->test.prog_fd);
4800 if (IS_ERR(prog))
4801 return PTR_ERR(prog);
4802
4803 if (prog->aux->ops->test_run)
4804 ret = prog->aux->ops->test_run(prog, attr, uattr);
4805
4806 bpf_prog_put(prog);
4807 return ret;
4808 }
4809
4810 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4811
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4812 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4813 union bpf_attr __user *uattr,
4814 struct idr *idr,
4815 spinlock_t *lock)
4816 {
4817 u32 next_id = attr->start_id;
4818 int err = 0;
4819
4820 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4821 return -EINVAL;
4822
4823 if (!capable(CAP_SYS_ADMIN))
4824 return -EPERM;
4825
4826 next_id++;
4827 spin_lock_bh(lock);
4828 if (!idr_get_next(idr, &next_id))
4829 err = -ENOENT;
4830 spin_unlock_bh(lock);
4831
4832 if (!err)
4833 err = put_user(next_id, &uattr->next_id);
4834
4835 return err;
4836 }
4837
bpf_map_get_curr_or_next(u32 * id)4838 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4839 {
4840 struct bpf_map *map;
4841
4842 spin_lock_bh(&map_idr_lock);
4843 again:
4844 map = idr_get_next(&map_idr, id);
4845 if (map) {
4846 map = __bpf_map_inc_not_zero(map, false);
4847 if (IS_ERR(map)) {
4848 (*id)++;
4849 goto again;
4850 }
4851 }
4852 spin_unlock_bh(&map_idr_lock);
4853
4854 return map;
4855 }
4856
bpf_prog_get_curr_or_next(u32 * id)4857 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4858 {
4859 struct bpf_prog *prog;
4860
4861 spin_lock_bh(&prog_idr_lock);
4862 again:
4863 prog = idr_get_next(&prog_idr, id);
4864 if (prog) {
4865 prog = bpf_prog_inc_not_zero(prog);
4866 if (IS_ERR(prog)) {
4867 (*id)++;
4868 goto again;
4869 }
4870 }
4871 spin_unlock_bh(&prog_idr_lock);
4872
4873 return prog;
4874 }
4875
4876 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4877
bpf_prog_by_id(u32 id)4878 struct bpf_prog *bpf_prog_by_id(u32 id)
4879 {
4880 struct bpf_prog *prog;
4881
4882 if (!id)
4883 return ERR_PTR(-ENOENT);
4884
4885 spin_lock_bh(&prog_idr_lock);
4886 prog = idr_find(&prog_idr, id);
4887 if (prog)
4888 prog = bpf_prog_inc_not_zero(prog);
4889 else
4890 prog = ERR_PTR(-ENOENT);
4891 spin_unlock_bh(&prog_idr_lock);
4892 return prog;
4893 }
4894
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4895 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4896 {
4897 struct bpf_prog *prog;
4898 u32 id = attr->prog_id;
4899 int fd;
4900
4901 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4902 return -EINVAL;
4903
4904 if (!capable(CAP_SYS_ADMIN))
4905 return -EPERM;
4906
4907 prog = bpf_prog_by_id(id);
4908 if (IS_ERR(prog))
4909 return PTR_ERR(prog);
4910
4911 fd = bpf_prog_new_fd(prog);
4912 if (fd < 0)
4913 bpf_prog_put(prog);
4914
4915 return fd;
4916 }
4917
4918 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4919
bpf_map_get_fd_by_id(const union bpf_attr * attr)4920 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4921 {
4922 struct bpf_map *map;
4923 u32 id = attr->map_id;
4924 int f_flags;
4925 int fd;
4926
4927 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4928 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4929 return -EINVAL;
4930
4931 if (!capable(CAP_SYS_ADMIN))
4932 return -EPERM;
4933
4934 f_flags = bpf_get_file_flag(attr->open_flags);
4935 if (f_flags < 0)
4936 return f_flags;
4937
4938 spin_lock_bh(&map_idr_lock);
4939 map = idr_find(&map_idr, id);
4940 if (map)
4941 map = __bpf_map_inc_not_zero(map, true);
4942 else
4943 map = ERR_PTR(-ENOENT);
4944 spin_unlock_bh(&map_idr_lock);
4945
4946 if (IS_ERR(map))
4947 return PTR_ERR(map);
4948
4949 fd = bpf_map_new_fd(map, f_flags);
4950 if (fd < 0)
4951 bpf_map_put_with_uref(map);
4952
4953 return fd;
4954 }
4955
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4956 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4957 unsigned long addr, u32 *off,
4958 u32 *type)
4959 {
4960 const struct bpf_map *map;
4961 int i;
4962
4963 mutex_lock(&prog->aux->used_maps_mutex);
4964 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4965 map = prog->aux->used_maps[i];
4966 if (map == (void *)addr) {
4967 *type = BPF_PSEUDO_MAP_FD;
4968 goto out;
4969 }
4970 if (!map->ops->map_direct_value_meta)
4971 continue;
4972 if (!map->ops->map_direct_value_meta(map, addr, off)) {
4973 *type = BPF_PSEUDO_MAP_VALUE;
4974 goto out;
4975 }
4976 }
4977 map = NULL;
4978
4979 out:
4980 mutex_unlock(&prog->aux->used_maps_mutex);
4981 return map;
4982 }
4983
prepare_dump_pseudo_call(struct bpf_insn * insn)4984 static void prepare_dump_pseudo_call(struct bpf_insn *insn)
4985 {
4986 s32 call_off = insn->imm;
4987
4988 /*
4989 * BPF_CALL_ARGS only exists for interpreter fallback.
4990 * 1. For interpreter (BPF_CALL_ARGS): insn->off is the index of
4991 * interpreters_args array, so here using bpf_call_args_imm()
4992 * to get the real address offset.
4993 * 2. For JIT (BPF_CALL): insn->off is the subprog id.
4994 */
4995 if (insn->code == (BPF_JMP | BPF_CALL_ARGS))
4996 insn->imm = bpf_call_args_imm(insn->off);
4997 else
4998 insn->imm = insn->off;
4999
5000 /* Avoid dumping a truncated and misleading pc-relative offset. */
5001 if (call_off > S16_MAX || call_off < S16_MIN)
5002 insn->off = 0;
5003 else
5004 insn->off = call_off;
5005 }
5006
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)5007 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
5008 const struct cred *f_cred)
5009 {
5010 const struct bpf_map *map;
5011 struct bpf_insn *insns;
5012 u32 off, type;
5013 u64 imm;
5014 u8 code;
5015 int i;
5016
5017 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
5018 GFP_USER);
5019 if (!insns)
5020 return insns;
5021
5022 for (i = 0; i < prog->len; i++) {
5023 code = insns[i].code;
5024
5025 if (code == (BPF_JMP | BPF_TAIL_CALL)) {
5026 insns[i].code = BPF_JMP | BPF_CALL;
5027 insns[i].imm = BPF_FUNC_tail_call;
5028 /* fall-through */
5029 }
5030 if (code == (BPF_JMP | BPF_CALL) ||
5031 code == (BPF_JMP | BPF_CALL_ARGS)) {
5032 /* Restore the legacy xlated dump layout. */
5033 if (insns[i].src_reg == BPF_PSEUDO_CALL)
5034 prepare_dump_pseudo_call(&insns[i]);
5035 if (code == (BPF_JMP | BPF_CALL_ARGS))
5036 insns[i].code = BPF_JMP | BPF_CALL;
5037 if (!bpf_dump_raw_ok(f_cred))
5038 insns[i].imm = 0;
5039 continue;
5040 }
5041 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
5042 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
5043 continue;
5044 }
5045
5046 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
5047 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
5048 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
5049 continue;
5050 }
5051
5052 if (code != (BPF_LD | BPF_IMM | BPF_DW))
5053 continue;
5054
5055 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
5056 map = bpf_map_from_imm(prog, imm, &off, &type);
5057 if (map) {
5058 insns[i].src_reg = type;
5059 insns[i].imm = map->id;
5060 insns[i + 1].imm = off;
5061 continue;
5062 }
5063 }
5064
5065 return insns;
5066 }
5067
set_info_rec_size(struct bpf_prog_info * info)5068 static int set_info_rec_size(struct bpf_prog_info *info)
5069 {
5070 /*
5071 * Ensure info.*_rec_size is the same as kernel expected size
5072 *
5073 * or
5074 *
5075 * Only allow zero *_rec_size if both _rec_size and _cnt are
5076 * zero. In this case, the kernel will set the expected
5077 * _rec_size back to the info.
5078 */
5079
5080 if ((info->nr_func_info || info->func_info_rec_size) &&
5081 info->func_info_rec_size != sizeof(struct bpf_func_info))
5082 return -EINVAL;
5083
5084 if ((info->nr_line_info || info->line_info_rec_size) &&
5085 info->line_info_rec_size != sizeof(struct bpf_line_info))
5086 return -EINVAL;
5087
5088 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
5089 info->jited_line_info_rec_size != sizeof(__u64))
5090 return -EINVAL;
5091
5092 info->func_info_rec_size = sizeof(struct bpf_func_info);
5093 info->line_info_rec_size = sizeof(struct bpf_line_info);
5094 info->jited_line_info_rec_size = sizeof(__u64);
5095
5096 return 0;
5097 }
5098
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)5099 static int bpf_prog_get_info_by_fd(struct file *file,
5100 struct bpf_prog *prog,
5101 const union bpf_attr *attr,
5102 union bpf_attr __user *uattr)
5103 {
5104 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5105 struct btf *attach_btf = bpf_prog_get_target_btf(prog);
5106 struct bpf_prog_info info;
5107 u32 info_len = attr->info.info_len;
5108 struct bpf_prog_kstats stats;
5109 char __user *uinsns;
5110 u32 ulen, len;
5111 int err;
5112
5113 len = offsetofend(struct bpf_prog_info, attach_btf_id);
5114 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), len, info_len);
5115 if (err)
5116 return err;
5117 info_len = min_t(u32, sizeof(info), info_len);
5118
5119 memset(&info, 0, sizeof(info));
5120 if (copy_from_user(&info, uinfo, info_len))
5121 return -EFAULT;
5122
5123 info.type = prog->type;
5124 info.id = prog->aux->id;
5125 info.load_time = prog->aux->load_time;
5126 info.created_by_uid = from_kuid_munged(current_user_ns(),
5127 prog->aux->user->uid);
5128 info.gpl_compatible = prog->gpl_compatible;
5129
5130 memcpy(info.tag, prog->tag, sizeof(prog->tag));
5131 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
5132
5133 mutex_lock(&prog->aux->used_maps_mutex);
5134 ulen = info.nr_map_ids;
5135 info.nr_map_ids = prog->aux->used_map_cnt;
5136 ulen = min_t(u32, info.nr_map_ids, ulen);
5137 if (ulen) {
5138 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
5139 u32 i;
5140
5141 for (i = 0; i < ulen; i++)
5142 if (put_user(prog->aux->used_maps[i]->id,
5143 &user_map_ids[i])) {
5144 mutex_unlock(&prog->aux->used_maps_mutex);
5145 return -EFAULT;
5146 }
5147 }
5148 mutex_unlock(&prog->aux->used_maps_mutex);
5149
5150 err = set_info_rec_size(&info);
5151 if (err)
5152 return err;
5153
5154 bpf_prog_get_stats(prog, &stats);
5155 info.run_time_ns = stats.nsecs;
5156 info.run_cnt = stats.cnt;
5157 info.recursion_misses = stats.misses;
5158
5159 info.verified_insns = prog->aux->verified_insns;
5160 if (prog->aux->btf)
5161 info.btf_id = btf_obj_id(prog->aux->btf);
5162
5163 if (!bpf_capable()) {
5164 info.jited_prog_len = 0;
5165 info.xlated_prog_len = 0;
5166 info.nr_jited_ksyms = 0;
5167 info.nr_jited_func_lens = 0;
5168 info.nr_func_info = 0;
5169 info.nr_line_info = 0;
5170 info.nr_jited_line_info = 0;
5171 goto done;
5172 }
5173
5174 ulen = info.xlated_prog_len;
5175 info.xlated_prog_len = bpf_prog_insn_size(prog);
5176 if (info.xlated_prog_len && ulen) {
5177 struct bpf_insn *insns_sanitized;
5178 bool fault;
5179
5180 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) {
5181 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
5182 if (!insns_sanitized)
5183 return -ENOMEM;
5184 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
5185 ulen = min_t(u32, info.xlated_prog_len, ulen);
5186 fault = copy_to_user(uinsns, insns_sanitized, ulen);
5187 kfree(insns_sanitized);
5188 if (fault)
5189 return -EFAULT;
5190 } else {
5191 info.xlated_prog_insns = 0;
5192 }
5193 }
5194
5195 if (bpf_prog_is_offloaded(prog->aux)) {
5196 err = bpf_prog_offload_info_fill(&info, prog);
5197 if (err)
5198 return err;
5199 goto done;
5200 }
5201
5202 /* NOTE: the following code is supposed to be skipped for offload.
5203 * bpf_prog_offload_info_fill() is the place to fill similar fields
5204 * for offload.
5205 */
5206 ulen = info.jited_prog_len;
5207 if (prog->aux->func_cnt) {
5208 u32 i;
5209
5210 info.jited_prog_len = 0;
5211 for (i = 0; i < prog->aux->func_cnt; i++)
5212 info.jited_prog_len += prog->aux->func[i]->jited_len;
5213 } else {
5214 info.jited_prog_len = prog->jited_len;
5215 }
5216
5217 if (info.jited_prog_len && ulen) {
5218 if (bpf_dump_raw_ok(file->f_cred)) {
5219 uinsns = u64_to_user_ptr(info.jited_prog_insns);
5220 ulen = min_t(u32, info.jited_prog_len, ulen);
5221
5222 /* for multi-function programs, copy the JITed
5223 * instructions for all the functions
5224 */
5225 if (prog->aux->func_cnt) {
5226 u32 len, free, i;
5227 u8 *img;
5228
5229 free = ulen;
5230 for (i = 0; i < prog->aux->func_cnt; i++) {
5231 len = prog->aux->func[i]->jited_len;
5232 len = min_t(u32, len, free);
5233 img = (u8 *) prog->aux->func[i]->bpf_func;
5234 if (copy_to_user(uinsns, img, len))
5235 return -EFAULT;
5236 uinsns += len;
5237 free -= len;
5238 if (!free)
5239 break;
5240 }
5241 } else {
5242 if (copy_to_user(uinsns, prog->bpf_func, ulen))
5243 return -EFAULT;
5244 }
5245 } else {
5246 info.jited_prog_insns = 0;
5247 }
5248 }
5249
5250 ulen = info.nr_jited_ksyms;
5251 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
5252 if (ulen) {
5253 if (bpf_dump_raw_ok(file->f_cred)) {
5254 unsigned long ksym_addr;
5255 u64 __user *user_ksyms;
5256 u32 i;
5257
5258 /* copy the address of the kernel symbol
5259 * corresponding to each function
5260 */
5261 ulen = min_t(u32, info.nr_jited_ksyms, ulen);
5262 user_ksyms = u64_to_user_ptr(info.jited_ksyms);
5263 if (prog->aux->func_cnt) {
5264 for (i = 0; i < ulen; i++) {
5265 ksym_addr = (unsigned long)
5266 prog->aux->func[i]->bpf_func;
5267 if (put_user((u64) ksym_addr,
5268 &user_ksyms[i]))
5269 return -EFAULT;
5270 }
5271 } else {
5272 ksym_addr = (unsigned long) prog->bpf_func;
5273 if (put_user((u64) ksym_addr, &user_ksyms[0]))
5274 return -EFAULT;
5275 }
5276 } else {
5277 info.jited_ksyms = 0;
5278 }
5279 }
5280
5281 ulen = info.nr_jited_func_lens;
5282 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
5283 if (ulen) {
5284 if (bpf_dump_raw_ok(file->f_cred)) {
5285 u32 __user *user_lens;
5286 u32 func_len, i;
5287
5288 /* copy the JITed image lengths for each function */
5289 ulen = min_t(u32, info.nr_jited_func_lens, ulen);
5290 user_lens = u64_to_user_ptr(info.jited_func_lens);
5291 if (prog->aux->func_cnt) {
5292 for (i = 0; i < ulen; i++) {
5293 func_len =
5294 prog->aux->func[i]->jited_len;
5295 if (put_user(func_len, &user_lens[i]))
5296 return -EFAULT;
5297 }
5298 } else {
5299 func_len = prog->jited_len;
5300 if (put_user(func_len, &user_lens[0]))
5301 return -EFAULT;
5302 }
5303 } else {
5304 info.jited_func_lens = 0;
5305 }
5306 }
5307
5308 info.attach_btf_id = prog->aux->attach_btf_id;
5309 if (attach_btf)
5310 info.attach_btf_obj_id = btf_obj_id(attach_btf);
5311
5312 ulen = info.nr_func_info;
5313 info.nr_func_info = prog->aux->func_info_cnt;
5314 if (info.nr_func_info && ulen) {
5315 char __user *user_finfo;
5316
5317 user_finfo = u64_to_user_ptr(info.func_info);
5318 ulen = min_t(u32, info.nr_func_info, ulen);
5319 if (copy_to_user(user_finfo, prog->aux->func_info,
5320 info.func_info_rec_size * ulen))
5321 return -EFAULT;
5322 }
5323
5324 ulen = info.nr_line_info;
5325 info.nr_line_info = prog->aux->nr_linfo;
5326 if (info.nr_line_info && ulen) {
5327 __u8 __user *user_linfo;
5328
5329 user_linfo = u64_to_user_ptr(info.line_info);
5330 ulen = min_t(u32, info.nr_line_info, ulen);
5331 if (copy_to_user(user_linfo, prog->aux->linfo,
5332 info.line_info_rec_size * ulen))
5333 return -EFAULT;
5334 }
5335
5336 ulen = info.nr_jited_line_info;
5337 if (prog->aux->jited_linfo)
5338 info.nr_jited_line_info = prog->aux->nr_linfo;
5339 else
5340 info.nr_jited_line_info = 0;
5341 if (info.nr_jited_line_info && ulen) {
5342 if (bpf_dump_raw_ok(file->f_cred)) {
5343 unsigned long line_addr;
5344 __u64 __user *user_linfo;
5345 u32 i;
5346
5347 user_linfo = u64_to_user_ptr(info.jited_line_info);
5348 ulen = min_t(u32, info.nr_jited_line_info, ulen);
5349 for (i = 0; i < ulen; i++) {
5350 line_addr = (unsigned long)prog->aux->jited_linfo[i];
5351 if (put_user((__u64)line_addr, &user_linfo[i]))
5352 return -EFAULT;
5353 }
5354 } else {
5355 info.jited_line_info = 0;
5356 }
5357 }
5358
5359 ulen = info.nr_prog_tags;
5360 info.nr_prog_tags = prog->aux->func_cnt ? : 1;
5361 if (ulen) {
5362 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
5363 u32 i;
5364
5365 user_prog_tags = u64_to_user_ptr(info.prog_tags);
5366 ulen = min_t(u32, info.nr_prog_tags, ulen);
5367 if (prog->aux->func_cnt) {
5368 for (i = 0; i < ulen; i++) {
5369 if (copy_to_user(user_prog_tags[i],
5370 prog->aux->func[i]->tag,
5371 BPF_TAG_SIZE))
5372 return -EFAULT;
5373 }
5374 } else {
5375 if (copy_to_user(user_prog_tags[0],
5376 prog->tag, BPF_TAG_SIZE))
5377 return -EFAULT;
5378 }
5379 }
5380
5381 done:
5382 if (copy_to_user(uinfo, &info, info_len) ||
5383 put_user(info_len, &uattr->info.info_len))
5384 return -EFAULT;
5385
5386 return 0;
5387 }
5388
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)5389 static int bpf_map_get_info_by_fd(struct file *file,
5390 struct bpf_map *map,
5391 const union bpf_attr *attr,
5392 union bpf_attr __user *uattr)
5393 {
5394 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5395 struct bpf_map_info info;
5396 u32 info_len = attr->info.info_len, len;
5397 int err;
5398
5399 len = offsetofend(struct bpf_map_info, hash_size);
5400 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), len, info_len);
5401 if (err)
5402 return err;
5403 info_len = min_t(u32, sizeof(info), info_len);
5404
5405 memset(&info, 0, sizeof(info));
5406 if (copy_from_user(&info, uinfo, info_len))
5407 return -EFAULT;
5408
5409 info.type = map->map_type;
5410 info.id = map->id;
5411 info.key_size = map->key_size;
5412 info.value_size = map->value_size;
5413 info.max_entries = map->max_entries;
5414 info.map_flags = map->map_flags;
5415 info.map_extra = map->map_extra;
5416 memcpy(info.name, map->name, sizeof(map->name));
5417
5418 if (map->btf) {
5419 info.btf_id = btf_obj_id(map->btf);
5420 info.btf_key_type_id = map->btf_key_type_id;
5421 info.btf_value_type_id = map->btf_value_type_id;
5422 }
5423 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5424 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5425 bpf_map_struct_ops_info_fill(&info, map);
5426
5427 if (bpf_map_is_offloaded(map)) {
5428 err = bpf_map_offload_info_fill(&info, map);
5429 if (err)
5430 return err;
5431 }
5432
5433 if (info.hash) {
5434 char __user *uhash = u64_to_user_ptr(info.hash);
5435
5436 if (!map->ops->map_get_hash)
5437 return -EINVAL;
5438 if (info.hash_size != sizeof(map->sha))
5439 return -EINVAL;
5440 if (!READ_ONCE(map->frozen))
5441 return -EPERM;
5442
5443 err = map->ops->map_get_hash(map);
5444 if (err != 0)
5445 return err;
5446
5447 if (copy_to_user(uhash, map->sha, sizeof(map->sha)) != 0)
5448 return -EFAULT;
5449 } else if (info.hash_size) {
5450 return -EINVAL;
5451 }
5452
5453 if (copy_to_user(uinfo, &info, info_len) ||
5454 put_user(info_len, &uattr->info.info_len))
5455 return -EFAULT;
5456
5457 return 0;
5458 }
5459
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5460 static int bpf_btf_get_info_by_fd(struct file *file,
5461 struct btf *btf,
5462 const union bpf_attr *attr,
5463 union bpf_attr __user *uattr)
5464 {
5465 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5466 u32 info_len = attr->info.info_len;
5467 int err;
5468
5469 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5470 if (err)
5471 return err;
5472
5473 return btf_get_info_by_fd(btf, attr, uattr);
5474 }
5475
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5476 static int bpf_link_get_info_by_fd(struct file *file,
5477 struct bpf_link *link,
5478 const union bpf_attr *attr,
5479 union bpf_attr __user *uattr)
5480 {
5481 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5482 struct bpf_link_info info;
5483 const struct bpf_prog *prog;
5484 u32 info_len = attr->info.info_len;
5485 int err;
5486
5487 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5488 if (err)
5489 return err;
5490 info_len = min_t(u32, sizeof(info), info_len);
5491
5492 memset(&info, 0, sizeof(info));
5493 if (copy_from_user(&info, uinfo, info_len))
5494 return -EFAULT;
5495
5496 info.type = link->type;
5497 info.id = link->id;
5498
5499 rcu_read_lock();
5500 prog = READ_ONCE(link->prog);
5501 if (prog)
5502 info.prog_id = prog->aux->id;
5503 rcu_read_unlock();
5504
5505 if (link->ops->fill_link_info) {
5506 err = link->ops->fill_link_info(link, &info);
5507 if (err)
5508 return err;
5509 }
5510
5511 if (copy_to_user(uinfo, &info, info_len) ||
5512 put_user(info_len, &uattr->info.info_len))
5513 return -EFAULT;
5514
5515 return 0;
5516 }
5517
token_get_info_by_fd(struct file * file,struct bpf_token * token,const union bpf_attr * attr,union bpf_attr __user * uattr)5518 static int token_get_info_by_fd(struct file *file,
5519 struct bpf_token *token,
5520 const union bpf_attr *attr,
5521 union bpf_attr __user *uattr)
5522 {
5523 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5524 u32 info_len = attr->info.info_len;
5525 int err;
5526
5527 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5528 if (err)
5529 return err;
5530 return bpf_token_get_info_by_fd(token, attr, uattr);
5531 }
5532
5533 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5534
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5535 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5536 union bpf_attr __user *uattr)
5537 {
5538 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5539 return -EINVAL;
5540
5541 CLASS(fd, f)(attr->info.bpf_fd);
5542 if (fd_empty(f))
5543 return -EBADFD;
5544
5545 if (fd_file(f)->f_op == &bpf_prog_fops)
5546 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5547 uattr);
5548 else if (fd_file(f)->f_op == &bpf_map_fops)
5549 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5550 uattr);
5551 else if (fd_file(f)->f_op == &btf_fops)
5552 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5553 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5554 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5555 attr, uattr);
5556 else if (fd_file(f)->f_op == &bpf_token_fops)
5557 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5558 attr, uattr);
5559 return -EINVAL;
5560 }
5561
5562 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5563
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,struct bpf_log_attr * attr_log)5564 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_log_attr *attr_log)
5565 {
5566 struct bpf_token *token = NULL;
5567
5568 if (CHECK_ATTR(BPF_BTF_LOAD))
5569 return -EINVAL;
5570
5571 if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5572 return -EINVAL;
5573
5574 if (attr->btf_flags & BPF_F_TOKEN_FD) {
5575 token = bpf_token_get_from_fd(attr->btf_token_fd);
5576 if (IS_ERR(token))
5577 return PTR_ERR(token);
5578 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5579 bpf_token_put(token);
5580 token = NULL;
5581 }
5582 }
5583
5584 if (!bpf_token_capable(token, CAP_BPF)) {
5585 bpf_token_put(token);
5586 return -EPERM;
5587 }
5588
5589 bpf_token_put(token);
5590
5591 return btf_new_fd(attr, uattr, attr_log);
5592 }
5593
5594 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5595
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5596 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5597 {
5598 struct bpf_token *token = NULL;
5599
5600 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5601 return -EINVAL;
5602
5603 if (attr->open_flags & ~BPF_F_TOKEN_FD)
5604 return -EINVAL;
5605
5606 if (attr->open_flags & BPF_F_TOKEN_FD) {
5607 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5608 if (IS_ERR(token))
5609 return PTR_ERR(token);
5610 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5611 bpf_token_put(token);
5612 token = NULL;
5613 }
5614 }
5615
5616 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5617 bpf_token_put(token);
5618 return -EPERM;
5619 }
5620
5621 bpf_token_put(token);
5622
5623 return btf_get_fd_by_id(attr->btf_id);
5624 }
5625
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)5626 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5627 union bpf_attr __user *uattr,
5628 u32 prog_id, u32 fd_type,
5629 const char *buf, u64 probe_offset,
5630 u64 probe_addr)
5631 {
5632 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5633 u32 len = buf ? strlen(buf) : 0, input_len;
5634 int err = 0;
5635
5636 if (put_user(len, &uattr->task_fd_query.buf_len))
5637 return -EFAULT;
5638 input_len = attr->task_fd_query.buf_len;
5639 if (input_len && ubuf) {
5640 if (!len) {
5641 /* nothing to copy, just make ubuf NULL terminated */
5642 char zero = '\0';
5643
5644 if (put_user(zero, ubuf))
5645 return -EFAULT;
5646 } else {
5647 err = bpf_copy_to_user(ubuf, buf, input_len, len);
5648 if (err == -EFAULT)
5649 return err;
5650 }
5651 }
5652
5653 if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5654 put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5655 put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5656 put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5657 return -EFAULT;
5658
5659 return err;
5660 }
5661
5662 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5663
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5664 static int bpf_task_fd_query(const union bpf_attr *attr,
5665 union bpf_attr __user *uattr)
5666 {
5667 pid_t pid = attr->task_fd_query.pid;
5668 u32 fd = attr->task_fd_query.fd;
5669 const struct perf_event *event;
5670 struct task_struct *task;
5671 struct file *file;
5672 int err;
5673
5674 if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5675 return -EINVAL;
5676
5677 if (!capable(CAP_SYS_ADMIN))
5678 return -EPERM;
5679
5680 if (attr->task_fd_query.flags != 0)
5681 return -EINVAL;
5682
5683 rcu_read_lock();
5684 task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5685 rcu_read_unlock();
5686 if (!task)
5687 return -ENOENT;
5688
5689 err = 0;
5690 file = fget_task(task, fd);
5691 put_task_struct(task);
5692 if (!file)
5693 return -EBADF;
5694
5695 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5696 struct bpf_link *link = file->private_data;
5697
5698 if (link->ops == &bpf_raw_tp_link_lops) {
5699 struct bpf_raw_tp_link *raw_tp =
5700 container_of(link, struct bpf_raw_tp_link, link);
5701 struct bpf_raw_event_map *btp = raw_tp->btp;
5702
5703 err = bpf_task_fd_query_copy(attr, uattr,
5704 raw_tp->link.prog->aux->id,
5705 BPF_FD_TYPE_RAW_TRACEPOINT,
5706 btp->tp->name, 0, 0);
5707 goto put_file;
5708 }
5709 goto out_not_supp;
5710 }
5711
5712 event = perf_get_event(file);
5713 if (!IS_ERR(event)) {
5714 u64 probe_offset, probe_addr;
5715 u32 prog_id, fd_type;
5716 const char *buf;
5717
5718 err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5719 &buf, &probe_offset,
5720 &probe_addr, NULL);
5721 if (!err)
5722 err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5723 fd_type, buf,
5724 probe_offset,
5725 probe_addr);
5726 goto put_file;
5727 }
5728
5729 out_not_supp:
5730 err = -ENOTSUPP;
5731 put_file:
5732 fput(file);
5733 return err;
5734 }
5735
5736 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5737
5738 #define BPF_DO_BATCH(fn, ...) \
5739 do { \
5740 if (!fn) { \
5741 err = -ENOTSUPP; \
5742 goto err_put; \
5743 } \
5744 err = fn(__VA_ARGS__); \
5745 } while (0)
5746
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5747 static int bpf_map_do_batch(const union bpf_attr *attr,
5748 union bpf_attr __user *uattr,
5749 int cmd)
5750 {
5751 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH ||
5752 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5753 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5754 struct bpf_map *map;
5755 int err;
5756
5757 if (CHECK_ATTR(BPF_MAP_BATCH))
5758 return -EINVAL;
5759
5760 CLASS(fd, f)(attr->batch.map_fd);
5761
5762 map = __bpf_map_get(f);
5763 if (IS_ERR(map))
5764 return PTR_ERR(map);
5765 if (has_write)
5766 bpf_map_write_active_inc(map);
5767 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5768 err = -EPERM;
5769 goto err_put;
5770 }
5771 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5772 err = -EPERM;
5773 goto err_put;
5774 }
5775
5776 if (cmd == BPF_MAP_LOOKUP_BATCH)
5777 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5778 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5779 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5780 else if (cmd == BPF_MAP_UPDATE_BATCH)
5781 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5782 else
5783 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5784 err_put:
5785 if (has_write) {
5786 maybe_wait_bpf_programs(map);
5787 bpf_map_write_active_dec(map);
5788 }
5789 return err;
5790 }
5791
5792 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.path_fd
link_create(union bpf_attr * attr,bpfptr_t uattr)5793 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5794 {
5795 struct bpf_prog *prog;
5796 int ret;
5797
5798 if (CHECK_ATTR(BPF_LINK_CREATE))
5799 return -EINVAL;
5800
5801 if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5802 return bpf_struct_ops_link_create(attr);
5803
5804 prog = bpf_prog_get(attr->link_create.prog_fd);
5805 if (IS_ERR(prog))
5806 return PTR_ERR(prog);
5807
5808 ret = bpf_prog_attach_check_attach_type(prog,
5809 attr->link_create.attach_type);
5810 if (ret)
5811 goto out;
5812
5813 switch (prog->type) {
5814 case BPF_PROG_TYPE_CGROUP_SKB:
5815 case BPF_PROG_TYPE_CGROUP_SOCK:
5816 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5817 case BPF_PROG_TYPE_SOCK_OPS:
5818 case BPF_PROG_TYPE_CGROUP_DEVICE:
5819 case BPF_PROG_TYPE_CGROUP_SYSCTL:
5820 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5821 ret = cgroup_bpf_link_attach(attr, prog);
5822 break;
5823 case BPF_PROG_TYPE_EXT:
5824 ret = bpf_tracing_prog_attach(prog,
5825 attr->link_create.target_fd,
5826 attr->link_create.target_btf_id,
5827 attr->link_create.tracing.cookie,
5828 attr->link_create.attach_type);
5829 break;
5830 case BPF_PROG_TYPE_LSM:
5831 case BPF_PROG_TYPE_TRACING:
5832 if (attr->link_create.attach_type != prog->expected_attach_type) {
5833 ret = -EINVAL;
5834 goto out;
5835 }
5836 if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5837 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie,
5838 attr->link_create.attach_type);
5839 else if (prog->expected_attach_type == BPF_TRACE_ITER)
5840 ret = bpf_iter_link_attach(attr, uattr, prog);
5841 else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5842 ret = cgroup_bpf_link_attach(attr, prog);
5843 else if (is_tracing_multi(prog->expected_attach_type))
5844 ret = bpf_tracing_multi_attach(prog, attr);
5845 else
5846 ret = bpf_tracing_prog_attach(prog,
5847 attr->link_create.target_fd,
5848 attr->link_create.target_btf_id,
5849 attr->link_create.tracing.cookie,
5850 attr->link_create.attach_type);
5851 break;
5852 case BPF_PROG_TYPE_FLOW_DISSECTOR:
5853 case BPF_PROG_TYPE_SK_LOOKUP:
5854 ret = netns_bpf_link_create(attr, prog);
5855 break;
5856 case BPF_PROG_TYPE_SK_MSG:
5857 case BPF_PROG_TYPE_SK_SKB:
5858 ret = sock_map_link_create(attr, prog);
5859 break;
5860 #ifdef CONFIG_NET
5861 case BPF_PROG_TYPE_XDP:
5862 ret = bpf_xdp_link_attach(attr, prog);
5863 break;
5864 case BPF_PROG_TYPE_SCHED_CLS:
5865 if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5866 attr->link_create.attach_type == BPF_TCX_EGRESS)
5867 ret = tcx_link_attach(attr, prog);
5868 else
5869 ret = netkit_link_attach(attr, prog);
5870 break;
5871 case BPF_PROG_TYPE_NETFILTER:
5872 ret = bpf_nf_link_attach(attr, prog);
5873 break;
5874 #endif
5875 case BPF_PROG_TYPE_PERF_EVENT:
5876 case BPF_PROG_TYPE_TRACEPOINT:
5877 ret = bpf_perf_link_attach(attr, prog);
5878 break;
5879 case BPF_PROG_TYPE_KPROBE:
5880 if (attr->link_create.attach_type == BPF_PERF_EVENT)
5881 ret = bpf_perf_link_attach(attr, prog);
5882 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5883 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5884 ret = bpf_kprobe_multi_link_attach(attr, prog);
5885 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5886 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5887 ret = bpf_uprobe_multi_link_attach(attr, prog);
5888 break;
5889 default:
5890 ret = -EINVAL;
5891 }
5892
5893 out:
5894 if (ret < 0)
5895 bpf_prog_put(prog);
5896 return ret;
5897 }
5898
link_update_map(struct bpf_link * link,union bpf_attr * attr)5899 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5900 {
5901 struct bpf_map *new_map, *old_map = NULL;
5902 int ret;
5903
5904 new_map = bpf_map_get(attr->link_update.new_map_fd);
5905 if (IS_ERR(new_map))
5906 return PTR_ERR(new_map);
5907
5908 if (attr->link_update.flags & BPF_F_REPLACE) {
5909 old_map = bpf_map_get(attr->link_update.old_map_fd);
5910 if (IS_ERR(old_map)) {
5911 ret = PTR_ERR(old_map);
5912 goto out_put;
5913 }
5914 } else if (attr->link_update.old_map_fd) {
5915 ret = -EINVAL;
5916 goto out_put;
5917 }
5918
5919 ret = link->ops->update_map(link, new_map, old_map);
5920
5921 if (old_map)
5922 bpf_map_put(old_map);
5923 out_put:
5924 bpf_map_put(new_map);
5925 return ret;
5926 }
5927
5928 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5929
link_update(union bpf_attr * attr)5930 static int link_update(union bpf_attr *attr)
5931 {
5932 struct bpf_prog *old_prog = NULL, *new_prog;
5933 struct bpf_link *link;
5934 u32 flags;
5935 int ret;
5936
5937 if (CHECK_ATTR(BPF_LINK_UPDATE))
5938 return -EINVAL;
5939
5940 flags = attr->link_update.flags;
5941 if (flags & ~BPF_F_REPLACE)
5942 return -EINVAL;
5943
5944 link = bpf_link_get_from_fd(attr->link_update.link_fd);
5945 if (IS_ERR(link))
5946 return PTR_ERR(link);
5947
5948 if (link->ops->update_map) {
5949 ret = link_update_map(link, attr);
5950 goto out_put_link;
5951 }
5952
5953 new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5954 if (IS_ERR(new_prog)) {
5955 ret = PTR_ERR(new_prog);
5956 goto out_put_link;
5957 }
5958
5959 if (flags & BPF_F_REPLACE) {
5960 old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5961 if (IS_ERR(old_prog)) {
5962 ret = PTR_ERR(old_prog);
5963 old_prog = NULL;
5964 goto out_put_progs;
5965 }
5966 } else if (attr->link_update.old_prog_fd) {
5967 ret = -EINVAL;
5968 goto out_put_progs;
5969 }
5970
5971 if (link->ops->update_prog)
5972 ret = link->ops->update_prog(link, new_prog, old_prog);
5973 else
5974 ret = -EINVAL;
5975
5976 out_put_progs:
5977 if (old_prog)
5978 bpf_prog_put(old_prog);
5979 if (ret)
5980 bpf_prog_put(new_prog);
5981 out_put_link:
5982 bpf_link_put_direct(link);
5983 return ret;
5984 }
5985
5986 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5987
link_detach(union bpf_attr * attr)5988 static int link_detach(union bpf_attr *attr)
5989 {
5990 struct bpf_link *link;
5991 int ret;
5992
5993 if (CHECK_ATTR(BPF_LINK_DETACH))
5994 return -EINVAL;
5995
5996 link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5997 if (IS_ERR(link))
5998 return PTR_ERR(link);
5999
6000 if (link->ops->detach)
6001 ret = link->ops->detach(link);
6002 else
6003 ret = -EOPNOTSUPP;
6004
6005 bpf_link_put_direct(link);
6006 return ret;
6007 }
6008
bpf_link_inc_not_zero(struct bpf_link * link)6009 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
6010 {
6011 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
6012 }
6013 EXPORT_SYMBOL(bpf_link_inc_not_zero);
6014
bpf_link_by_id(u32 id)6015 struct bpf_link *bpf_link_by_id(u32 id)
6016 {
6017 struct bpf_link *link;
6018
6019 if (!id)
6020 return ERR_PTR(-ENOENT);
6021
6022 spin_lock_bh(&link_idr_lock);
6023 /* before link is "settled", ID is 0, pretend it doesn't exist yet */
6024 link = idr_find(&link_idr, id);
6025 if (link) {
6026 if (link->id)
6027 link = bpf_link_inc_not_zero(link);
6028 else
6029 link = ERR_PTR(-EAGAIN);
6030 } else {
6031 link = ERR_PTR(-ENOENT);
6032 }
6033 spin_unlock_bh(&link_idr_lock);
6034 return link;
6035 }
6036
bpf_link_get_curr_or_next(u32 * id)6037 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
6038 {
6039 struct bpf_link *link;
6040
6041 spin_lock_bh(&link_idr_lock);
6042 again:
6043 link = idr_get_next(&link_idr, id);
6044 if (link) {
6045 link = bpf_link_inc_not_zero(link);
6046 if (IS_ERR(link)) {
6047 (*id)++;
6048 goto again;
6049 }
6050 }
6051 spin_unlock_bh(&link_idr_lock);
6052
6053 return link;
6054 }
6055
6056 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
6057
bpf_link_get_fd_by_id(const union bpf_attr * attr)6058 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
6059 {
6060 struct bpf_link *link;
6061 u32 id = attr->link_id;
6062 int fd;
6063
6064 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
6065 return -EINVAL;
6066
6067 if (!capable(CAP_SYS_ADMIN))
6068 return -EPERM;
6069
6070 link = bpf_link_by_id(id);
6071 if (IS_ERR(link))
6072 return PTR_ERR(link);
6073
6074 fd = bpf_link_new_fd(link);
6075 if (fd < 0)
6076 bpf_link_put_direct(link);
6077
6078 return fd;
6079 }
6080
6081 DEFINE_MUTEX(bpf_stats_enabled_mutex);
6082
bpf_stats_release(struct inode * inode,struct file * file)6083 static int bpf_stats_release(struct inode *inode, struct file *file)
6084 {
6085 mutex_lock(&bpf_stats_enabled_mutex);
6086 static_key_slow_dec(&bpf_stats_enabled_key.key);
6087 mutex_unlock(&bpf_stats_enabled_mutex);
6088 return 0;
6089 }
6090
6091 static const struct file_operations bpf_stats_fops = {
6092 .release = bpf_stats_release,
6093 };
6094
bpf_enable_runtime_stats(void)6095 static int bpf_enable_runtime_stats(void)
6096 {
6097 int fd;
6098
6099 mutex_lock(&bpf_stats_enabled_mutex);
6100
6101 /* Set a very high limit to avoid overflow */
6102 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
6103 mutex_unlock(&bpf_stats_enabled_mutex);
6104 return -EBUSY;
6105 }
6106
6107 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
6108 if (fd >= 0)
6109 static_key_slow_inc(&bpf_stats_enabled_key.key);
6110
6111 mutex_unlock(&bpf_stats_enabled_mutex);
6112 return fd;
6113 }
6114
6115 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
6116
bpf_enable_stats(union bpf_attr * attr)6117 static int bpf_enable_stats(union bpf_attr *attr)
6118 {
6119
6120 if (CHECK_ATTR(BPF_ENABLE_STATS))
6121 return -EINVAL;
6122
6123 if (!capable(CAP_SYS_ADMIN))
6124 return -EPERM;
6125
6126 switch (attr->enable_stats.type) {
6127 case BPF_STATS_RUN_TIME:
6128 return bpf_enable_runtime_stats();
6129 default:
6130 break;
6131 }
6132 return -EINVAL;
6133 }
6134
6135 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
6136
bpf_iter_create(union bpf_attr * attr)6137 static int bpf_iter_create(union bpf_attr *attr)
6138 {
6139 struct bpf_link *link;
6140 int err;
6141
6142 if (CHECK_ATTR(BPF_ITER_CREATE))
6143 return -EINVAL;
6144
6145 if (attr->iter_create.flags)
6146 return -EINVAL;
6147
6148 link = bpf_link_get_from_fd(attr->iter_create.link_fd);
6149 if (IS_ERR(link))
6150 return PTR_ERR(link);
6151
6152 err = bpf_iter_new_fd(link);
6153 bpf_link_put_direct(link);
6154
6155 return err;
6156 }
6157
6158 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
6159
bpf_prog_bind_map(union bpf_attr * attr)6160 static int bpf_prog_bind_map(union bpf_attr *attr)
6161 {
6162 struct bpf_prog *prog;
6163 struct bpf_map *map;
6164 struct bpf_map **used_maps_old, **used_maps_new;
6165 int i, ret = 0;
6166
6167 if (CHECK_ATTR(BPF_PROG_BIND_MAP))
6168 return -EINVAL;
6169
6170 if (attr->prog_bind_map.flags)
6171 return -EINVAL;
6172
6173 prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
6174 if (IS_ERR(prog))
6175 return PTR_ERR(prog);
6176
6177 map = bpf_map_get(attr->prog_bind_map.map_fd);
6178 if (IS_ERR(map)) {
6179 ret = PTR_ERR(map);
6180 goto out_prog_put;
6181 }
6182
6183 mutex_lock(&prog->aux->used_maps_mutex);
6184
6185 used_maps_old = prog->aux->used_maps;
6186
6187 for (i = 0; i < prog->aux->used_map_cnt; i++)
6188 if (used_maps_old[i] == map) {
6189 bpf_map_put(map);
6190 goto out_unlock;
6191 }
6192
6193 used_maps_new = kmalloc_objs(used_maps_new[0],
6194 prog->aux->used_map_cnt + 1);
6195 if (!used_maps_new) {
6196 ret = -ENOMEM;
6197 goto out_unlock;
6198 }
6199
6200 /* The bpf program will not access the bpf map, but for the sake of
6201 * simplicity, increase sleepable_refcnt for sleepable program as well.
6202 */
6203 if (prog->sleepable)
6204 atomic64_inc(&map->sleepable_refcnt);
6205 memcpy(used_maps_new, used_maps_old,
6206 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
6207 used_maps_new[prog->aux->used_map_cnt] = map;
6208
6209 prog->aux->used_map_cnt++;
6210 prog->aux->used_maps = used_maps_new;
6211
6212 kfree(used_maps_old);
6213
6214 out_unlock:
6215 mutex_unlock(&prog->aux->used_maps_mutex);
6216
6217 if (ret)
6218 bpf_map_put(map);
6219 out_prog_put:
6220 bpf_prog_put(prog);
6221 return ret;
6222 }
6223
6224 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
6225
token_create(union bpf_attr * attr)6226 static int token_create(union bpf_attr *attr)
6227 {
6228 if (CHECK_ATTR(BPF_TOKEN_CREATE))
6229 return -EINVAL;
6230
6231 /* no flags are supported yet */
6232 if (attr->token_create.flags)
6233 return -EINVAL;
6234
6235 return bpf_token_create(attr);
6236 }
6237
6238 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd
6239
prog_stream_read(union bpf_attr * attr)6240 static int prog_stream_read(union bpf_attr *attr)
6241 {
6242 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf);
6243 u32 len = attr->prog_stream_read.stream_buf_len;
6244 struct bpf_prog *prog;
6245 int ret;
6246
6247 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD))
6248 return -EINVAL;
6249
6250 prog = bpf_prog_get(attr->prog_stream_read.prog_fd);
6251 if (IS_ERR(prog))
6252 return PTR_ERR(prog);
6253
6254 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len);
6255 bpf_prog_put(prog);
6256
6257 return ret;
6258 }
6259
6260 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.flags
6261
prog_assoc_struct_ops(union bpf_attr * attr)6262 static int prog_assoc_struct_ops(union bpf_attr *attr)
6263 {
6264 struct bpf_prog *prog;
6265 struct bpf_map *map;
6266 int ret;
6267
6268 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS))
6269 return -EINVAL;
6270
6271 if (attr->prog_assoc_struct_ops.flags)
6272 return -EINVAL;
6273
6274 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd);
6275 if (IS_ERR(prog))
6276 return PTR_ERR(prog);
6277
6278 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) {
6279 ret = -EINVAL;
6280 goto put_prog;
6281 }
6282
6283 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd);
6284 if (IS_ERR(map)) {
6285 ret = PTR_ERR(map);
6286 goto put_prog;
6287 }
6288
6289 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) {
6290 ret = -EINVAL;
6291 goto put_map;
6292 }
6293
6294 ret = bpf_prog_assoc_struct_ops(prog, map);
6295
6296 put_map:
6297 bpf_map_put(map);
6298 put_prog:
6299 bpf_prog_put(prog);
6300 return ret;
6301 }
6302
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size,bpfptr_t uattr_common,unsigned int size_common)6303 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size,
6304 bpfptr_t uattr_common, unsigned int size_common)
6305 {
6306 struct bpf_common_attr attr_common;
6307 u32 offsetof_log_true_size = 0;
6308 struct bpf_log_attr attr_log;
6309 union bpf_attr attr;
6310 int err;
6311
6312 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
6313 if (err)
6314 return err;
6315 size = min_t(u32, size, sizeof(attr));
6316
6317 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
6318 memset(&attr, 0, sizeof(attr));
6319 if (copy_from_bpfptr(&attr, uattr, size) != 0)
6320 return -EFAULT;
6321
6322 memset(&attr_common, 0, sizeof(attr_common));
6323 if (cmd & BPF_COMMON_ATTRS) {
6324 err = bpf_check_uarg_tail_zero(uattr_common,
6325 offsetofend(struct bpf_common_attr, log_true_size),
6326 size_common);
6327 if (err)
6328 return err;
6329
6330 cmd &= ~BPF_COMMON_ATTRS;
6331 size_common = min_t(u32, size_common, sizeof(attr_common));
6332 if (copy_from_bpfptr(&attr_common, uattr_common, size_common) != 0)
6333 return -EFAULT;
6334 } else {
6335 size_common = 0;
6336 }
6337
6338 err = security_bpf(cmd, &attr, size, uattr.is_kernel);
6339 if (err < 0)
6340 return err;
6341
6342 switch (cmd) {
6343 case BPF_MAP_CREATE:
6344 err = map_create(&attr, uattr, &attr_common, uattr_common, size_common);
6345 break;
6346 case BPF_MAP_LOOKUP_ELEM:
6347 err = map_lookup_elem(&attr);
6348 break;
6349 case BPF_MAP_UPDATE_ELEM:
6350 err = map_update_elem(&attr, uattr);
6351 break;
6352 case BPF_MAP_DELETE_ELEM:
6353 err = map_delete_elem(&attr, uattr);
6354 break;
6355 case BPF_MAP_GET_NEXT_KEY:
6356 err = map_get_next_key(&attr);
6357 break;
6358 case BPF_MAP_FREEZE:
6359 err = map_freeze(&attr);
6360 break;
6361 case BPF_PROG_LOAD:
6362 if (size >= offsetofend(union bpf_attr, log_true_size))
6363 offsetof_log_true_size = offsetof(union bpf_attr, log_true_size);
6364 err = bpf_log_attr_init(&attr_log, attr.log_buf, attr.log_size, attr.log_level,
6365 offsetof_log_true_size, uattr, &attr_common, uattr_common,
6366 size_common);
6367 err = err ?: bpf_prog_load(&attr, uattr, &attr_log);
6368 break;
6369 case BPF_OBJ_PIN:
6370 err = bpf_obj_pin(&attr);
6371 break;
6372 case BPF_OBJ_GET:
6373 err = bpf_obj_get(&attr);
6374 break;
6375 case BPF_PROG_ATTACH:
6376 err = bpf_prog_attach(&attr);
6377 break;
6378 case BPF_PROG_DETACH:
6379 err = bpf_prog_detach(&attr);
6380 break;
6381 case BPF_PROG_QUERY:
6382 err = bpf_prog_query(&attr, uattr.user, size);
6383 break;
6384 case BPF_PROG_TEST_RUN:
6385 err = bpf_prog_test_run(&attr, uattr.user);
6386 break;
6387 case BPF_PROG_GET_NEXT_ID:
6388 err = bpf_obj_get_next_id(&attr, uattr.user,
6389 &prog_idr, &prog_idr_lock);
6390 break;
6391 case BPF_MAP_GET_NEXT_ID:
6392 err = bpf_obj_get_next_id(&attr, uattr.user,
6393 &map_idr, &map_idr_lock);
6394 break;
6395 case BPF_BTF_GET_NEXT_ID:
6396 err = bpf_obj_get_next_id(&attr, uattr.user,
6397 &btf_idr, &btf_idr_lock);
6398 break;
6399 case BPF_PROG_GET_FD_BY_ID:
6400 err = bpf_prog_get_fd_by_id(&attr);
6401 break;
6402 case BPF_MAP_GET_FD_BY_ID:
6403 err = bpf_map_get_fd_by_id(&attr);
6404 break;
6405 case BPF_OBJ_GET_INFO_BY_FD:
6406 err = bpf_obj_get_info_by_fd(&attr, uattr.user);
6407 break;
6408 case BPF_RAW_TRACEPOINT_OPEN:
6409 err = bpf_raw_tracepoint_open(&attr);
6410 break;
6411 case BPF_BTF_LOAD:
6412 if (size >= offsetofend(union bpf_attr, btf_log_true_size))
6413 offsetof_log_true_size = offsetof(union bpf_attr, btf_log_true_size);
6414 err = bpf_log_attr_init(&attr_log, attr.btf_log_buf, attr.btf_log_size,
6415 attr.btf_log_level, offsetof_log_true_size, uattr,
6416 &attr_common, uattr_common, size_common);
6417 err = err ?: bpf_btf_load(&attr, uattr, &attr_log);
6418 break;
6419 case BPF_BTF_GET_FD_BY_ID:
6420 err = bpf_btf_get_fd_by_id(&attr);
6421 break;
6422 case BPF_TASK_FD_QUERY:
6423 err = bpf_task_fd_query(&attr, uattr.user);
6424 break;
6425 case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
6426 err = map_lookup_and_delete_elem(&attr);
6427 break;
6428 case BPF_MAP_LOOKUP_BATCH:
6429 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
6430 break;
6431 case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
6432 err = bpf_map_do_batch(&attr, uattr.user,
6433 BPF_MAP_LOOKUP_AND_DELETE_BATCH);
6434 break;
6435 case BPF_MAP_UPDATE_BATCH:
6436 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
6437 break;
6438 case BPF_MAP_DELETE_BATCH:
6439 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
6440 break;
6441 case BPF_LINK_CREATE:
6442 err = link_create(&attr, uattr);
6443 break;
6444 case BPF_LINK_UPDATE:
6445 err = link_update(&attr);
6446 break;
6447 case BPF_LINK_GET_FD_BY_ID:
6448 err = bpf_link_get_fd_by_id(&attr);
6449 break;
6450 case BPF_LINK_GET_NEXT_ID:
6451 err = bpf_obj_get_next_id(&attr, uattr.user,
6452 &link_idr, &link_idr_lock);
6453 break;
6454 case BPF_ENABLE_STATS:
6455 err = bpf_enable_stats(&attr);
6456 break;
6457 case BPF_ITER_CREATE:
6458 err = bpf_iter_create(&attr);
6459 break;
6460 case BPF_LINK_DETACH:
6461 err = link_detach(&attr);
6462 break;
6463 case BPF_PROG_BIND_MAP:
6464 err = bpf_prog_bind_map(&attr);
6465 break;
6466 case BPF_TOKEN_CREATE:
6467 err = token_create(&attr);
6468 break;
6469 case BPF_PROG_STREAM_READ_BY_FD:
6470 err = prog_stream_read(&attr);
6471 break;
6472 case BPF_PROG_ASSOC_STRUCT_OPS:
6473 err = prog_assoc_struct_ops(&attr);
6474 break;
6475 default:
6476 err = -EINVAL;
6477 break;
6478 }
6479
6480 return err;
6481 }
6482
SYSCALL_DEFINE5(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size,struct bpf_common_attr __user *,uattr_common,unsigned int,size_common)6483 SYSCALL_DEFINE5(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size,
6484 struct bpf_common_attr __user *, uattr_common, unsigned int, size_common)
6485 {
6486 return __sys_bpf(cmd, USER_BPFPTR(uattr), size, USER_BPFPTR(uattr_common), size_common);
6487 }
6488
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)6489 static bool syscall_prog_is_valid_access(int off, int size,
6490 enum bpf_access_type type,
6491 const struct bpf_prog *prog,
6492 struct bpf_insn_access_aux *info)
6493 {
6494 if (off < 0 || off >= U16_MAX)
6495 return false;
6496 /* No alignment requirements for syscall ctx accesses. */
6497 return true;
6498 }
6499
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)6500 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
6501 {
6502 switch (cmd) {
6503 case BPF_MAP_CREATE:
6504 case BPF_MAP_DELETE_ELEM:
6505 case BPF_MAP_UPDATE_ELEM:
6506 case BPF_MAP_FREEZE:
6507 case BPF_MAP_GET_FD_BY_ID:
6508 case BPF_PROG_LOAD:
6509 case BPF_BTF_LOAD:
6510 case BPF_LINK_CREATE:
6511 case BPF_RAW_TRACEPOINT_OPEN:
6512 break;
6513 default:
6514 return -EINVAL;
6515 }
6516 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size, KERNEL_BPFPTR(NULL), 0);
6517 }
6518
6519 /* To shut up -Wmissing-prototypes.
6520 * This function is used by the kernel light skeleton
6521 * to load bpf programs when modules are loaded or during kernel boot.
6522 * See tools/lib/bpf/skel_internal.h
6523 */
6524 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
6525
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)6526 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
6527 {
6528 struct bpf_prog * __maybe_unused prog;
6529 struct bpf_tramp_run_ctx __maybe_unused run_ctx;
6530
6531 switch (cmd) {
6532 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
6533 case BPF_PROG_TEST_RUN:
6534 if (attr->test.data_in || attr->test.data_out ||
6535 attr->test.ctx_out || attr->test.duration ||
6536 attr->test.repeat || attr->test.flags)
6537 return -EINVAL;
6538
6539 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
6540 if (IS_ERR(prog))
6541 return PTR_ERR(prog);
6542
6543 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6544 attr->test.ctx_size_in > U16_MAX) {
6545 bpf_prog_put(prog);
6546 return -EINVAL;
6547 }
6548
6549 run_ctx.bpf_cookie = 0;
6550 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6551 /* recursion detected */
6552 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6553 bpf_prog_put(prog);
6554 return -EBUSY;
6555 }
6556 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6557 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6558 &run_ctx);
6559 bpf_prog_put(prog);
6560 return 0;
6561 #endif
6562 default:
6563 return ____bpf_sys_bpf(cmd, attr, size);
6564 }
6565 }
6566 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL");
6567
6568 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6569 .func = bpf_sys_bpf,
6570 .gpl_only = false,
6571 .ret_type = RET_INTEGER,
6572 .arg1_type = ARG_ANYTHING,
6573 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
6574 .arg3_type = ARG_MEM_SIZE,
6575 };
6576
6577 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6578 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6579 {
6580 return bpf_base_func_proto(func_id, prog);
6581 }
6582
BPF_CALL_1(bpf_sys_close,u32,fd)6583 BPF_CALL_1(bpf_sys_close, u32, fd)
6584 {
6585 /* When bpf program calls this helper there should not be
6586 * an fdget() without matching completed fdput().
6587 * This helper is allowed in the following callchain only:
6588 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6589 */
6590 return close_fd(fd);
6591 }
6592
6593 static const struct bpf_func_proto bpf_sys_close_proto = {
6594 .func = bpf_sys_close,
6595 .gpl_only = false,
6596 .ret_type = RET_INTEGER,
6597 .arg1_type = ARG_ANYTHING,
6598 };
6599
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6600 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6601 {
6602 *res = 0;
6603 if (flags)
6604 return -EINVAL;
6605
6606 if (name_sz <= 1 || name[name_sz - 1])
6607 return -EINVAL;
6608
6609 if (!bpf_dump_raw_ok(current_cred()))
6610 return -EPERM;
6611
6612 *res = kallsyms_lookup_name(name);
6613 return *res ? 0 : -ENOENT;
6614 }
6615
6616 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6617 .func = bpf_kallsyms_lookup_name,
6618 .gpl_only = false,
6619 .ret_type = RET_INTEGER,
6620 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
6621 .arg2_type = ARG_MEM_SIZE_OR_ZERO,
6622 .arg3_type = ARG_ANYTHING,
6623 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6624 .arg4_size = sizeof(u64),
6625 };
6626
6627 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6628 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6629 {
6630 switch (func_id) {
6631 case BPF_FUNC_sys_bpf:
6632 return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6633 ? NULL : &bpf_sys_bpf_proto;
6634 case BPF_FUNC_btf_find_by_name_kind:
6635 return &bpf_btf_find_by_name_kind_proto;
6636 case BPF_FUNC_sys_close:
6637 return &bpf_sys_close_proto;
6638 case BPF_FUNC_kallsyms_lookup_name:
6639 return &bpf_kallsyms_lookup_name_proto;
6640 default:
6641 return tracing_prog_func_proto(func_id, prog);
6642 }
6643 }
6644
6645 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6646 .get_func_proto = syscall_prog_func_proto,
6647 .is_valid_access = syscall_prog_is_valid_access,
6648 };
6649
6650 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6651 .test_run = bpf_prog_test_run_syscall,
6652 };
6653
6654 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6655 static int bpf_stats_handler(const struct ctl_table *table, int write,
6656 void *buffer, size_t *lenp, loff_t *ppos)
6657 {
6658 struct static_key *key = (struct static_key *)table->data;
6659 static int saved_val;
6660 int val, ret;
6661 struct ctl_table tmp = {
6662 .data = &val,
6663 .maxlen = sizeof(val),
6664 .mode = table->mode,
6665 .extra1 = SYSCTL_ZERO,
6666 .extra2 = SYSCTL_ONE,
6667 };
6668
6669 if (write && !capable(CAP_SYS_ADMIN))
6670 return -EPERM;
6671
6672 mutex_lock(&bpf_stats_enabled_mutex);
6673 val = saved_val;
6674 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6675 if (write && !ret && val != saved_val) {
6676 if (val)
6677 static_key_slow_inc(key);
6678 else
6679 static_key_slow_dec(key);
6680 saved_val = val;
6681 }
6682 mutex_unlock(&bpf_stats_enabled_mutex);
6683 return ret;
6684 }
6685
unpriv_ebpf_notify(int new_state)6686 void __weak unpriv_ebpf_notify(int new_state)
6687 {
6688 }
6689
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6690 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6691 void *buffer, size_t *lenp, loff_t *ppos)
6692 {
6693 int ret, unpriv_enable = *(int *)table->data;
6694 bool locked_state = unpriv_enable == 1;
6695 struct ctl_table tmp = *table;
6696
6697 if (write && !capable(CAP_SYS_ADMIN))
6698 return -EPERM;
6699
6700 tmp.data = &unpriv_enable;
6701 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6702 if (write && !ret) {
6703 if (locked_state && unpriv_enable != 1)
6704 return -EPERM;
6705 *(int *)table->data = unpriv_enable;
6706 }
6707
6708 if (write)
6709 unpriv_ebpf_notify(unpriv_enable);
6710
6711 return ret;
6712 }
6713
6714 static const struct ctl_table bpf_syscall_table[] = {
6715 {
6716 .procname = "unprivileged_bpf_disabled",
6717 .data = &sysctl_unprivileged_bpf_disabled,
6718 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
6719 .mode = 0644,
6720 .proc_handler = bpf_unpriv_handler,
6721 .extra1 = SYSCTL_ZERO,
6722 .extra2 = SYSCTL_TWO,
6723 },
6724 {
6725 .procname = "bpf_stats_enabled",
6726 .data = &bpf_stats_enabled_key.key,
6727 .mode = 0644,
6728 .proc_handler = bpf_stats_handler,
6729 },
6730 };
6731
bpf_syscall_sysctl_init(void)6732 static int __init bpf_syscall_sysctl_init(void)
6733 {
6734 register_sysctl_init("kernel", bpf_syscall_table);
6735 return 0;
6736 }
6737 late_initcall(bpf_syscall_sysctl_init);
6738 #endif /* CONFIG_SYSCTL */
6739