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/verification.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
639
btf_field_cmp(const void * a,const void * b)640 static int btf_field_cmp(const void *a, const void *b)
641 {
642 const struct btf_field *f1 = a, *f2 = b;
643
644 if (f1->offset < f2->offset)
645 return -1;
646 else if (f1->offset > f2->offset)
647 return 1;
648 return 0;
649 }
650
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)651 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
652 u32 field_mask)
653 {
654 struct btf_field *field;
655
656 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
657 return NULL;
658 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
659 if (!field || !(field->type & field_mask))
660 return NULL;
661 return field;
662 }
663
btf_record_free(struct btf_record * rec)664 void btf_record_free(struct btf_record *rec)
665 {
666 int i;
667
668 if (IS_ERR_OR_NULL(rec))
669 return;
670 for (i = 0; i < rec->cnt; i++) {
671 switch (rec->fields[i].type) {
672 case BPF_KPTR_UNREF:
673 case BPF_KPTR_REF:
674 case BPF_KPTR_PERCPU:
675 case BPF_UPTR:
676 if (rec->fields[i].kptr.module)
677 module_put(rec->fields[i].kptr.module);
678 if (btf_is_kernel(rec->fields[i].kptr.btf))
679 btf_put(rec->fields[i].kptr.btf);
680 break;
681 case BPF_LIST_HEAD:
682 case BPF_LIST_NODE:
683 case BPF_RB_ROOT:
684 case BPF_RB_NODE:
685 case BPF_SPIN_LOCK:
686 case BPF_RES_SPIN_LOCK:
687 case BPF_TIMER:
688 case BPF_REFCOUNT:
689 case BPF_WORKQUEUE:
690 case BPF_TASK_WORK:
691 /* Nothing to release */
692 break;
693 default:
694 WARN_ON_ONCE(1);
695 continue;
696 }
697 }
698 kfree(rec);
699 }
700
bpf_map_free_record(struct bpf_map * map)701 void bpf_map_free_record(struct bpf_map *map)
702 {
703 btf_record_free(map->record);
704 map->record = NULL;
705 }
706
btf_record_dup(const struct btf_record * rec)707 struct btf_record *btf_record_dup(const struct btf_record *rec)
708 {
709 const struct btf_field *fields;
710 struct btf_record *new_rec;
711 int ret, size, i;
712
713 if (IS_ERR_OR_NULL(rec))
714 return NULL;
715 size = struct_size(rec, fields, rec->cnt);
716 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
717 if (!new_rec)
718 return ERR_PTR(-ENOMEM);
719 /* Do a deep copy of the btf_record */
720 fields = rec->fields;
721 new_rec->cnt = 0;
722 for (i = 0; i < rec->cnt; i++) {
723 switch (fields[i].type) {
724 case BPF_KPTR_UNREF:
725 case BPF_KPTR_REF:
726 case BPF_KPTR_PERCPU:
727 case BPF_UPTR:
728 if (btf_is_kernel(fields[i].kptr.btf))
729 btf_get(fields[i].kptr.btf);
730 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
731 ret = -ENXIO;
732 goto free;
733 }
734 break;
735 case BPF_LIST_HEAD:
736 case BPF_LIST_NODE:
737 case BPF_RB_ROOT:
738 case BPF_RB_NODE:
739 case BPF_SPIN_LOCK:
740 case BPF_RES_SPIN_LOCK:
741 case BPF_TIMER:
742 case BPF_REFCOUNT:
743 case BPF_WORKQUEUE:
744 case BPF_TASK_WORK:
745 /* Nothing to acquire */
746 break;
747 default:
748 ret = -EFAULT;
749 WARN_ON_ONCE(1);
750 goto free;
751 }
752 new_rec->cnt++;
753 }
754 return new_rec;
755 free:
756 btf_record_free(new_rec);
757 return ERR_PTR(ret);
758 }
759
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)760 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
761 {
762 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
763 int size;
764
765 if (!a_has_fields && !b_has_fields)
766 return true;
767 if (a_has_fields != b_has_fields)
768 return false;
769 if (rec_a->cnt != rec_b->cnt)
770 return false;
771 size = struct_size(rec_a, fields, rec_a->cnt);
772 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
773 * members are zeroed out. So memcmp is safe to do without worrying
774 * about padding/unused fields.
775 *
776 * While spin_lock, timer, and kptr have no relation to map BTF,
777 * list_head metadata is specific to map BTF, the btf and value_rec
778 * members in particular. btf is the map BTF, while value_rec points to
779 * btf_record in that map BTF.
780 *
781 * So while by default, we don't rely on the map BTF (which the records
782 * were parsed from) matching for both records, which is not backwards
783 * compatible, in case list_head is part of it, we implicitly rely on
784 * that by way of depending on memcmp succeeding for it.
785 */
786 return !memcmp(rec_a, rec_b, size);
787 }
788
bpf_obj_free_timer(const struct btf_record * rec,void * obj)789 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
790 {
791 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
792 return;
793 bpf_timer_cancel_and_free(obj + rec->timer_off);
794 }
795
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)796 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
797 {
798 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
799 return;
800 bpf_wq_cancel_and_free(obj + rec->wq_off);
801 }
802
bpf_obj_free_task_work(const struct btf_record * rec,void * obj)803 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj)
804 {
805 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK)))
806 return;
807 bpf_task_work_cancel_and_free(obj + rec->task_work_off);
808 }
809
bpf_obj_free_fields(const struct btf_record * rec,void * obj)810 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
811 {
812 const struct btf_field *fields;
813 int i;
814
815 if (IS_ERR_OR_NULL(rec))
816 return;
817 fields = rec->fields;
818 for (i = 0; i < rec->cnt; i++) {
819 struct btf_struct_meta *pointee_struct_meta;
820 const struct btf_field *field = &fields[i];
821 void *field_ptr = obj + field->offset;
822 void *xchgd_field;
823
824 switch (fields[i].type) {
825 case BPF_SPIN_LOCK:
826 case BPF_RES_SPIN_LOCK:
827 break;
828 case BPF_TIMER:
829 bpf_timer_cancel_and_free(field_ptr);
830 break;
831 case BPF_WORKQUEUE:
832 bpf_wq_cancel_and_free(field_ptr);
833 break;
834 case BPF_TASK_WORK:
835 bpf_task_work_cancel_and_free(field_ptr);
836 break;
837 case BPF_KPTR_UNREF:
838 WRITE_ONCE(*(u64 *)field_ptr, 0);
839 break;
840 case BPF_KPTR_REF:
841 case BPF_KPTR_PERCPU:
842 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
843 if (!xchgd_field)
844 break;
845
846 if (!btf_is_kernel(field->kptr.btf)) {
847 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
848 field->kptr.btf_id);
849 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
850 pointee_struct_meta->record : NULL,
851 fields[i].type == BPF_KPTR_PERCPU);
852 } else {
853 field->kptr.dtor(xchgd_field);
854 }
855 break;
856 case BPF_UPTR:
857 /* The caller ensured that no one is using the uptr */
858 unpin_uptr_kaddr(*(void **)field_ptr);
859 break;
860 case BPF_LIST_HEAD:
861 if (WARN_ON_ONCE(rec->spin_lock_off < 0))
862 continue;
863 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
864 break;
865 case BPF_RB_ROOT:
866 if (WARN_ON_ONCE(rec->spin_lock_off < 0))
867 continue;
868 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
869 break;
870 case BPF_LIST_NODE:
871 case BPF_RB_NODE:
872 case BPF_REFCOUNT:
873 break;
874 default:
875 WARN_ON_ONCE(1);
876 continue;
877 }
878 }
879 }
880
bpf_map_free(struct bpf_map * map)881 static void bpf_map_free(struct bpf_map *map)
882 {
883 struct btf_record *rec = map->record;
884 struct btf *btf = map->btf;
885
886 /* implementation dependent freeing. Disabling migration to simplify
887 * the free of values or special fields allocated from bpf memory
888 * allocator.
889 */
890 kfree(map->excl_prog_sha);
891 migrate_disable();
892 map->ops->map_free(map);
893 migrate_enable();
894
895 /* Delay freeing of btf_record for maps, as map_free
896 * callback usually needs access to them. It is better to do it here
897 * than require each callback to do the free itself manually.
898 *
899 * Note that the btf_record stashed in map->inner_map_meta->record was
900 * already freed using the map_free callback for map in map case which
901 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
902 * template bpf_map struct used during verification.
903 */
904 btf_record_free(rec);
905 /* Delay freeing of btf for maps, as map_free callback may need
906 * struct_meta info which will be freed with btf_put().
907 */
908 btf_put(btf);
909 }
910
911 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)912 static void bpf_map_free_deferred(struct work_struct *work)
913 {
914 struct bpf_map *map = container_of(work, struct bpf_map, work);
915
916 security_bpf_map_free(map);
917 bpf_map_release_memcg(map);
918 bpf_map_owner_free(map);
919 bpf_map_free(map);
920 }
921
bpf_map_put_uref(struct bpf_map * map)922 static void bpf_map_put_uref(struct bpf_map *map)
923 {
924 if (atomic64_dec_and_test(&map->usercnt)) {
925 if (map->ops->map_release_uref)
926 map->ops->map_release_uref(map);
927 }
928 }
929
bpf_map_free_in_work(struct bpf_map * map)930 static void bpf_map_free_in_work(struct bpf_map *map)
931 {
932 INIT_WORK(&map->work, bpf_map_free_deferred);
933 /* Avoid spawning kworkers, since they all might contend
934 * for the same mutex like slab_mutex.
935 */
936 queue_work(system_dfl_wq, &map->work);
937 }
938
bpf_map_free_rcu_gp(struct rcu_head * rcu)939 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
940 {
941 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
942 }
943
944 /* decrement map refcnt and schedule it for freeing via workqueue
945 * (underlying map implementation ops->map_free() might sleep)
946 */
bpf_map_put(struct bpf_map * map)947 void bpf_map_put(struct bpf_map *map)
948 {
949 if (atomic64_dec_and_test(&map->refcnt)) {
950 /* bpf_map_free_id() must be called first */
951 bpf_map_free_id(map);
952
953 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
954 /* RCU tasks trace grace period implies RCU grace period. */
955 if (READ_ONCE(map->free_after_mult_rcu_gp))
956 call_rcu_tasks_trace(&map->rcu, bpf_map_free_rcu_gp);
957 else if (READ_ONCE(map->free_after_rcu_gp))
958 call_rcu(&map->rcu, bpf_map_free_rcu_gp);
959 else
960 bpf_map_free_in_work(map);
961 }
962 }
963 EXPORT_SYMBOL_GPL(bpf_map_put);
964
bpf_map_put_with_uref(struct bpf_map * map)965 void bpf_map_put_with_uref(struct bpf_map *map)
966 {
967 bpf_map_put_uref(map);
968 bpf_map_put(map);
969 }
970
bpf_map_release(struct inode * inode,struct file * filp)971 static int bpf_map_release(struct inode *inode, struct file *filp)
972 {
973 struct bpf_map *map = filp->private_data;
974
975 if (map->ops->map_release)
976 map->ops->map_release(map, filp);
977
978 bpf_map_put_with_uref(map);
979 return 0;
980 }
981
map_get_sys_perms(struct bpf_map * map,struct fd f)982 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
983 {
984 fmode_t mode = fd_file(f)->f_mode;
985
986 /* Our file permissions may have been overridden by global
987 * map permissions facing syscall side.
988 */
989 if (READ_ONCE(map->frozen))
990 mode &= ~FMODE_CAN_WRITE;
991 return mode;
992 }
993
994 #ifdef CONFIG_PROC_FS
995 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)996 static u64 bpf_map_memory_usage(const struct bpf_map *map)
997 {
998 return map->ops->map_mem_usage(map);
999 }
1000
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)1001 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
1002 {
1003 struct bpf_map *map = filp->private_data;
1004 u32 type = 0, jited = 0;
1005
1006 spin_lock(&map->owner_lock);
1007 if (map->owner) {
1008 type = map->owner->type;
1009 jited = map->owner->jited;
1010 }
1011 spin_unlock(&map->owner_lock);
1012
1013 seq_printf(m,
1014 "map_type:\t%u\n"
1015 "key_size:\t%u\n"
1016 "value_size:\t%u\n"
1017 "max_entries:\t%u\n"
1018 "map_flags:\t%#x\n"
1019 "map_extra:\t%#llx\n"
1020 "memlock:\t%llu\n"
1021 "map_id:\t%u\n"
1022 "frozen:\t%u\n",
1023 map->map_type,
1024 map->key_size,
1025 map->value_size,
1026 map->max_entries,
1027 map->map_flags,
1028 (unsigned long long)map->map_extra,
1029 bpf_map_memory_usage(map),
1030 map->id,
1031 READ_ONCE(map->frozen));
1032 if (type) {
1033 seq_printf(m, "owner_prog_type:\t%u\n", type);
1034 seq_printf(m, "owner_jited:\t%u\n", jited);
1035 }
1036 }
1037 #endif
1038
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)1039 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
1040 loff_t *ppos)
1041 {
1042 /* We need this handler such that alloc_file() enables
1043 * f_mode with FMODE_CAN_READ.
1044 */
1045 return -EINVAL;
1046 }
1047
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1048 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1049 size_t siz, loff_t *ppos)
1050 {
1051 /* We need this handler such that alloc_file() enables
1052 * f_mode with FMODE_CAN_WRITE.
1053 */
1054 return -EINVAL;
1055 }
1056
1057 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1058 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1059 {
1060 struct bpf_map *map = vma->vm_file->private_data;
1061
1062 if (vma->vm_flags & VM_MAYWRITE)
1063 bpf_map_write_active_inc(map);
1064 }
1065
1066 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1067 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1068 {
1069 struct bpf_map *map = vma->vm_file->private_data;
1070
1071 if (vma->vm_flags & VM_MAYWRITE)
1072 bpf_map_write_active_dec(map);
1073 }
1074
1075 static const struct vm_operations_struct bpf_map_default_vmops = {
1076 .open = bpf_map_mmap_open,
1077 .close = bpf_map_mmap_close,
1078 };
1079
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1080 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1081 {
1082 struct bpf_map *map = filp->private_data;
1083 int err = 0;
1084
1085 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1086 return -ENOTSUPP;
1087
1088 if (!(vma->vm_flags & VM_SHARED))
1089 return -EINVAL;
1090
1091 mutex_lock(&map->freeze_mutex);
1092
1093 if (vma->vm_flags & VM_WRITE) {
1094 if (map->frozen) {
1095 err = -EPERM;
1096 goto out;
1097 }
1098 /* map is meant to be read-only, so do not allow mapping as
1099 * writable, because it's possible to leak a writable page
1100 * reference and allows user-space to still modify it after
1101 * freezing, while verifier will assume contents do not change
1102 */
1103 if (map->map_flags & BPF_F_RDONLY_PROG) {
1104 err = -EACCES;
1105 goto out;
1106 }
1107 bpf_map_write_active_inc(map);
1108 }
1109 out:
1110 mutex_unlock(&map->freeze_mutex);
1111 if (err)
1112 return err;
1113
1114 /* set default open/close callbacks */
1115 vma->vm_ops = &bpf_map_default_vmops;
1116 vma->vm_private_data = map;
1117 vm_flags_clear(vma, VM_MAYEXEC);
1118 /* If mapping is read-only, then disallow potentially re-mapping with
1119 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1120 * means that as far as BPF map's memory-mapped VMAs are concerned,
1121 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1122 * both should be set, so we can forget about VM_MAYWRITE and always
1123 * check just VM_WRITE
1124 */
1125 if (!(vma->vm_flags & VM_WRITE))
1126 vm_flags_clear(vma, VM_MAYWRITE);
1127
1128 err = map->ops->map_mmap(map, vma);
1129 if (err) {
1130 if (vma->vm_flags & VM_WRITE)
1131 bpf_map_write_active_dec(map);
1132 }
1133
1134 return err;
1135 }
1136
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1137 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1138 {
1139 struct bpf_map *map = filp->private_data;
1140
1141 if (map->ops->map_poll)
1142 return map->ops->map_poll(map, filp, pts);
1143
1144 return EPOLLERR;
1145 }
1146
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1147 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1148 unsigned long len, unsigned long pgoff,
1149 unsigned long flags)
1150 {
1151 struct bpf_map *map = filp->private_data;
1152
1153 if (map->ops->map_get_unmapped_area)
1154 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1155 #ifdef CONFIG_MMU
1156 return mm_get_unmapped_area(filp, addr, len, pgoff, flags);
1157 #else
1158 return addr;
1159 #endif
1160 }
1161
1162 const struct file_operations bpf_map_fops = {
1163 #ifdef CONFIG_PROC_FS
1164 .show_fdinfo = bpf_map_show_fdinfo,
1165 #endif
1166 .release = bpf_map_release,
1167 .read = bpf_dummy_read,
1168 .write = bpf_dummy_write,
1169 .mmap = bpf_map_mmap,
1170 .poll = bpf_map_poll,
1171 .get_unmapped_area = bpf_get_unmapped_area,
1172 };
1173
bpf_map_new_fd(struct bpf_map * map,int flags)1174 int bpf_map_new_fd(struct bpf_map *map, int flags)
1175 {
1176 int ret;
1177
1178 ret = security_bpf_map(map, OPEN_FMODE(flags));
1179 if (ret < 0)
1180 return ret;
1181
1182 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1183 flags | O_CLOEXEC);
1184 }
1185
bpf_get_file_flag(int flags)1186 int bpf_get_file_flag(int flags)
1187 {
1188 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1189 return -EINVAL;
1190 if (flags & BPF_F_RDONLY)
1191 return O_RDONLY;
1192 if (flags & BPF_F_WRONLY)
1193 return O_WRONLY;
1194 return O_RDWR;
1195 }
1196
1197 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1198 #define CHECK_ATTR(CMD) \
1199 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1200 sizeof(attr->CMD##_LAST_FIELD), 0, \
1201 sizeof(*attr) - \
1202 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1203 sizeof(attr->CMD##_LAST_FIELD)) != NULL
1204
1205 /* dst and src must have at least "size" number of bytes.
1206 * Return strlen on success and < 0 on error.
1207 */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1208 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1209 {
1210 const char *end = src + size;
1211 const char *orig_src = src;
1212
1213 memset(dst, 0, size);
1214 /* Copy all isalnum(), '_' and '.' chars. */
1215 while (src < end && *src) {
1216 if (!isalnum(*src) &&
1217 *src != '_' && *src != '.')
1218 return -EINVAL;
1219 *dst++ = *src++;
1220 }
1221
1222 /* No '\0' found in "size" number of bytes */
1223 if (src == end)
1224 return -EINVAL;
1225
1226 return src - orig_src;
1227 }
1228 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy);
1229
map_check_no_btf(struct bpf_map * map,const struct btf * btf,const struct btf_type * key_type,const struct btf_type * value_type)1230 int map_check_no_btf(struct bpf_map *map,
1231 const struct btf *btf,
1232 const struct btf_type *key_type,
1233 const struct btf_type *value_type)
1234 {
1235 return -ENOTSUPP;
1236 }
1237
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1238 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1239 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1240 {
1241 const struct btf_type *key_type, *value_type;
1242 u32 key_size, value_size;
1243 int ret = 0;
1244
1245 /* Some maps allow key to be unspecified. */
1246 if (btf_key_id) {
1247 key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1248 if (!key_type || key_size != map->key_size)
1249 return -EINVAL;
1250 } else {
1251 key_type = btf_type_by_id(btf, 0);
1252 if (!map->ops->map_check_btf)
1253 return -EINVAL;
1254 }
1255
1256 value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1257 if (!value_type || value_size != map->value_size)
1258 return -EINVAL;
1259
1260 map->record = btf_parse_fields(btf, value_type,
1261 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1262 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR |
1263 BPF_TASK_WORK,
1264 map->value_size);
1265 if (!IS_ERR_OR_NULL(map->record)) {
1266 int i;
1267
1268 if (!bpf_token_capable(token, CAP_BPF)) {
1269 ret = -EPERM;
1270 goto free_map_tab;
1271 }
1272 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1273 ret = -EACCES;
1274 goto free_map_tab;
1275 }
1276 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1277 switch (map->record->field_mask & (1 << i)) {
1278 case 0:
1279 continue;
1280 case BPF_SPIN_LOCK:
1281 case BPF_RES_SPIN_LOCK:
1282 if (map->map_type != BPF_MAP_TYPE_HASH &&
1283 map->map_type != BPF_MAP_TYPE_ARRAY &&
1284 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1285 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1286 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1287 map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1288 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1289 ret = -EOPNOTSUPP;
1290 goto free_map_tab;
1291 }
1292 break;
1293 case BPF_TIMER:
1294 case BPF_WORKQUEUE:
1295 case BPF_TASK_WORK:
1296 if (map->map_type != BPF_MAP_TYPE_HASH &&
1297 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1298 map->map_type != BPF_MAP_TYPE_ARRAY) {
1299 ret = -EOPNOTSUPP;
1300 goto free_map_tab;
1301 }
1302 break;
1303 case BPF_KPTR_UNREF:
1304 case BPF_KPTR_REF:
1305 case BPF_KPTR_PERCPU:
1306 case BPF_REFCOUNT:
1307 if (map->map_type != BPF_MAP_TYPE_HASH &&
1308 map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1309 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1310 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1311 map->map_type != BPF_MAP_TYPE_ARRAY &&
1312 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1313 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1314 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1315 map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1316 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1317 ret = -EOPNOTSUPP;
1318 goto free_map_tab;
1319 }
1320 break;
1321 case BPF_UPTR:
1322 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1323 ret = -EOPNOTSUPP;
1324 goto free_map_tab;
1325 }
1326 break;
1327 case BPF_LIST_HEAD:
1328 case BPF_RB_ROOT:
1329 if (map->map_type != BPF_MAP_TYPE_HASH &&
1330 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1331 map->map_type != BPF_MAP_TYPE_ARRAY) {
1332 ret = -EOPNOTSUPP;
1333 goto free_map_tab;
1334 }
1335 break;
1336 default:
1337 /* Fail if map_type checks are missing for a field type */
1338 ret = -EOPNOTSUPP;
1339 goto free_map_tab;
1340 }
1341 }
1342 }
1343
1344 ret = btf_check_and_fixup_fields(btf, map->record);
1345 if (ret < 0)
1346 goto free_map_tab;
1347
1348 if (map->ops->map_check_btf) {
1349 ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1350 if (ret < 0)
1351 goto free_map_tab;
1352 }
1353
1354 return ret;
1355 free_map_tab:
1356 bpf_map_free_record(map);
1357 return ret;
1358 }
1359
1360 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size
1361 /* called via syscall */
map_create(union bpf_attr * attr,bpfptr_t uattr)1362 static int map_create(union bpf_attr *attr, bpfptr_t uattr)
1363 {
1364 const struct bpf_map_ops *ops;
1365 struct bpf_token *token = NULL;
1366 int numa_node = bpf_map_attr_numa_node(attr);
1367 u32 map_type = attr->map_type;
1368 struct bpf_map *map;
1369 bool token_flag;
1370 int f_flags;
1371 int err;
1372
1373 err = CHECK_ATTR(BPF_MAP_CREATE);
1374 if (err)
1375 return -EINVAL;
1376
1377 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1378 * to avoid per-map type checks tripping on unknown flag
1379 */
1380 token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1381 attr->map_flags &= ~BPF_F_TOKEN_FD;
1382
1383 if (attr->btf_vmlinux_value_type_id) {
1384 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1385 attr->btf_key_type_id || attr->btf_value_type_id)
1386 return -EINVAL;
1387 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1388 return -EINVAL;
1389 }
1390
1391 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1392 attr->map_type != BPF_MAP_TYPE_ARENA &&
1393 attr->map_extra != 0)
1394 return -EINVAL;
1395
1396 f_flags = bpf_get_file_flag(attr->map_flags);
1397 if (f_flags < 0)
1398 return f_flags;
1399
1400 if (numa_node != NUMA_NO_NODE &&
1401 ((unsigned int)numa_node >= nr_node_ids ||
1402 !node_online(numa_node)))
1403 return -EINVAL;
1404
1405 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1406 map_type = attr->map_type;
1407 if (map_type >= ARRAY_SIZE(bpf_map_types))
1408 return -EINVAL;
1409 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1410 ops = bpf_map_types[map_type];
1411 if (!ops)
1412 return -EINVAL;
1413
1414 if (ops->map_alloc_check) {
1415 err = ops->map_alloc_check(attr);
1416 if (err)
1417 return err;
1418 }
1419 if (attr->map_ifindex)
1420 ops = &bpf_map_offload_ops;
1421 if (!ops->map_mem_usage)
1422 return -EINVAL;
1423
1424 if (token_flag) {
1425 token = bpf_token_get_from_fd(attr->map_token_fd);
1426 if (IS_ERR(token))
1427 return PTR_ERR(token);
1428
1429 /* if current token doesn't grant map creation permissions,
1430 * then we can't use this token, so ignore it and rely on
1431 * system-wide capabilities checks
1432 */
1433 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1434 !bpf_token_allow_map_type(token, attr->map_type)) {
1435 bpf_token_put(token);
1436 token = NULL;
1437 }
1438 }
1439
1440 err = -EPERM;
1441
1442 /* Intent here is for unprivileged_bpf_disabled to block BPF map
1443 * creation for unprivileged users; other actions depend
1444 * on fd availability and access to bpffs, so are dependent on
1445 * object creation success. Even with unprivileged BPF disabled,
1446 * capability checks are still carried out.
1447 */
1448 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1449 goto put_token;
1450
1451 /* check privileged map type permissions */
1452 switch (map_type) {
1453 case BPF_MAP_TYPE_ARRAY:
1454 case BPF_MAP_TYPE_PERCPU_ARRAY:
1455 case BPF_MAP_TYPE_PROG_ARRAY:
1456 case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1457 case BPF_MAP_TYPE_CGROUP_ARRAY:
1458 case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1459 case BPF_MAP_TYPE_HASH:
1460 case BPF_MAP_TYPE_PERCPU_HASH:
1461 case BPF_MAP_TYPE_HASH_OF_MAPS:
1462 case BPF_MAP_TYPE_RINGBUF:
1463 case BPF_MAP_TYPE_USER_RINGBUF:
1464 case BPF_MAP_TYPE_CGROUP_STORAGE:
1465 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1466 /* unprivileged */
1467 break;
1468 case BPF_MAP_TYPE_SK_STORAGE:
1469 case BPF_MAP_TYPE_INODE_STORAGE:
1470 case BPF_MAP_TYPE_TASK_STORAGE:
1471 case BPF_MAP_TYPE_CGRP_STORAGE:
1472 case BPF_MAP_TYPE_BLOOM_FILTER:
1473 case BPF_MAP_TYPE_LPM_TRIE:
1474 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1475 case BPF_MAP_TYPE_STACK_TRACE:
1476 case BPF_MAP_TYPE_QUEUE:
1477 case BPF_MAP_TYPE_STACK:
1478 case BPF_MAP_TYPE_LRU_HASH:
1479 case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1480 case BPF_MAP_TYPE_STRUCT_OPS:
1481 case BPF_MAP_TYPE_CPUMAP:
1482 case BPF_MAP_TYPE_ARENA:
1483 case BPF_MAP_TYPE_INSN_ARRAY:
1484 if (!bpf_token_capable(token, CAP_BPF))
1485 goto put_token;
1486 break;
1487 case BPF_MAP_TYPE_SOCKMAP:
1488 case BPF_MAP_TYPE_SOCKHASH:
1489 case BPF_MAP_TYPE_DEVMAP:
1490 case BPF_MAP_TYPE_DEVMAP_HASH:
1491 case BPF_MAP_TYPE_XSKMAP:
1492 if (!bpf_token_capable(token, CAP_NET_ADMIN))
1493 goto put_token;
1494 break;
1495 default:
1496 WARN(1, "unsupported map type %d", map_type);
1497 goto put_token;
1498 }
1499
1500 map = ops->map_alloc(attr);
1501 if (IS_ERR(map)) {
1502 err = PTR_ERR(map);
1503 goto put_token;
1504 }
1505 map->ops = ops;
1506 map->map_type = map_type;
1507
1508 err = bpf_obj_name_cpy(map->name, attr->map_name,
1509 sizeof(attr->map_name));
1510 if (err < 0)
1511 goto free_map;
1512
1513 preempt_disable();
1514 map->cookie = gen_cookie_next(&bpf_map_cookie);
1515 preempt_enable();
1516
1517 atomic64_set(&map->refcnt, 1);
1518 atomic64_set(&map->usercnt, 1);
1519 mutex_init(&map->freeze_mutex);
1520 spin_lock_init(&map->owner_lock);
1521
1522 if (attr->btf_key_type_id || attr->btf_value_type_id ||
1523 /* Even the map's value is a kernel's struct,
1524 * the bpf_prog.o must have BTF to begin with
1525 * to figure out the corresponding kernel's
1526 * counter part. Thus, attr->btf_fd has
1527 * to be valid also.
1528 */
1529 attr->btf_vmlinux_value_type_id) {
1530 struct btf *btf;
1531
1532 btf = btf_get_by_fd(attr->btf_fd);
1533 if (IS_ERR(btf)) {
1534 err = PTR_ERR(btf);
1535 goto free_map;
1536 }
1537 if (btf_is_kernel(btf)) {
1538 btf_put(btf);
1539 err = -EACCES;
1540 goto free_map;
1541 }
1542 map->btf = btf;
1543
1544 if (attr->btf_value_type_id) {
1545 err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1546 attr->btf_value_type_id);
1547 if (err)
1548 goto free_map;
1549 }
1550
1551 map->btf_key_type_id = attr->btf_key_type_id;
1552 map->btf_value_type_id = attr->btf_value_type_id;
1553 map->btf_vmlinux_value_type_id =
1554 attr->btf_vmlinux_value_type_id;
1555 }
1556
1557 if (attr->excl_prog_hash) {
1558 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel);
1559
1560 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) {
1561 err = -EINVAL;
1562 goto free_map;
1563 }
1564
1565 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
1566 if (!map->excl_prog_sha) {
1567 err = -ENOMEM;
1568 goto free_map;
1569 }
1570
1571 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) {
1572 err = -EFAULT;
1573 goto free_map;
1574 }
1575 } else if (attr->excl_prog_hash_size) {
1576 err = -EINVAL;
1577 goto free_map;
1578 }
1579
1580 err = security_bpf_map_create(map, attr, token, uattr.is_kernel);
1581 if (err)
1582 goto free_map_sec;
1583
1584 err = bpf_map_alloc_id(map);
1585 if (err)
1586 goto free_map_sec;
1587
1588 bpf_map_save_memcg(map);
1589 bpf_token_put(token);
1590
1591 err = bpf_map_new_fd(map, f_flags);
1592 if (err < 0) {
1593 /* failed to allocate fd.
1594 * bpf_map_put_with_uref() is needed because the above
1595 * bpf_map_alloc_id() has published the map
1596 * to the userspace and the userspace may
1597 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1598 */
1599 bpf_map_put_with_uref(map);
1600 return err;
1601 }
1602
1603 return err;
1604
1605 free_map_sec:
1606 security_bpf_map_free(map);
1607 free_map:
1608 bpf_map_free(map);
1609 put_token:
1610 bpf_token_put(token);
1611 return err;
1612 }
1613
bpf_map_inc(struct bpf_map * map)1614 void bpf_map_inc(struct bpf_map *map)
1615 {
1616 atomic64_inc(&map->refcnt);
1617 }
1618 EXPORT_SYMBOL_GPL(bpf_map_inc);
1619
bpf_map_inc_with_uref(struct bpf_map * map)1620 void bpf_map_inc_with_uref(struct bpf_map *map)
1621 {
1622 atomic64_inc(&map->refcnt);
1623 atomic64_inc(&map->usercnt);
1624 }
1625 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1626
bpf_map_get(u32 ufd)1627 struct bpf_map *bpf_map_get(u32 ufd)
1628 {
1629 CLASS(fd, f)(ufd);
1630 struct bpf_map *map = __bpf_map_get(f);
1631
1632 if (!IS_ERR(map))
1633 bpf_map_inc(map);
1634
1635 return map;
1636 }
1637 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL");
1638
bpf_map_get_with_uref(u32 ufd)1639 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1640 {
1641 CLASS(fd, f)(ufd);
1642 struct bpf_map *map = __bpf_map_get(f);
1643
1644 if (!IS_ERR(map))
1645 bpf_map_inc_with_uref(map);
1646
1647 return map;
1648 }
1649
1650 /* map_idr_lock should have been held or the map should have been
1651 * protected by rcu read lock.
1652 */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1653 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1654 {
1655 int refold;
1656
1657 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1658 if (!refold)
1659 return ERR_PTR(-ENOENT);
1660 if (uref)
1661 atomic64_inc(&map->usercnt);
1662
1663 return map;
1664 }
1665
bpf_map_inc_not_zero(struct bpf_map * map)1666 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1667 {
1668 lockdep_assert(rcu_read_lock_held());
1669 return __bpf_map_inc_not_zero(map, false);
1670 }
1671 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1672
bpf_stackmap_extract(struct bpf_map * map,void * key,void * value,bool delete)1673 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value,
1674 bool delete)
1675 {
1676 return -ENOTSUPP;
1677 }
1678
__bpf_copy_key(void __user * ukey,u64 key_size)1679 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1680 {
1681 if (key_size)
1682 return vmemdup_user(ukey, key_size);
1683
1684 if (ukey)
1685 return ERR_PTR(-EINVAL);
1686
1687 return NULL;
1688 }
1689
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1690 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1691 {
1692 if (key_size)
1693 return kvmemdup_bpfptr(ukey, key_size);
1694
1695 if (!bpfptr_is_null(ukey))
1696 return ERR_PTR(-EINVAL);
1697
1698 return NULL;
1699 }
1700
1701 /* last field in 'union bpf_attr' used by this command */
1702 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1703
map_lookup_elem(union bpf_attr * attr)1704 static int map_lookup_elem(union bpf_attr *attr)
1705 {
1706 void __user *ukey = u64_to_user_ptr(attr->key);
1707 void __user *uvalue = u64_to_user_ptr(attr->value);
1708 struct bpf_map *map;
1709 void *key, *value;
1710 u32 value_size;
1711 int err;
1712
1713 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1714 return -EINVAL;
1715
1716 CLASS(fd, f)(attr->map_fd);
1717 map = __bpf_map_get(f);
1718 if (IS_ERR(map))
1719 return PTR_ERR(map);
1720 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1721 return -EPERM;
1722
1723 err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK | BPF_F_CPU);
1724 if (err)
1725 return err;
1726
1727 key = __bpf_copy_key(ukey, map->key_size);
1728 if (IS_ERR(key))
1729 return PTR_ERR(key);
1730
1731 value_size = bpf_map_value_size(map, attr->flags);
1732
1733 err = -ENOMEM;
1734 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1735 if (!value)
1736 goto free_key;
1737
1738 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1739 if (copy_from_user(value, uvalue, value_size))
1740 err = -EFAULT;
1741 else
1742 err = bpf_map_copy_value(map, key, value, attr->flags);
1743 goto free_value;
1744 }
1745
1746 err = bpf_map_copy_value(map, key, value, attr->flags);
1747 if (err)
1748 goto free_value;
1749
1750 err = -EFAULT;
1751 if (copy_to_user(uvalue, value, value_size) != 0)
1752 goto free_value;
1753
1754 err = 0;
1755
1756 free_value:
1757 kvfree(value);
1758 free_key:
1759 kvfree(key);
1760 return err;
1761 }
1762
1763
1764 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1765
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1766 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1767 {
1768 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1769 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1770 struct bpf_map *map;
1771 void *key, *value;
1772 u32 value_size;
1773 int err;
1774
1775 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1776 return -EINVAL;
1777
1778 CLASS(fd, f)(attr->map_fd);
1779 map = __bpf_map_get(f);
1780 if (IS_ERR(map))
1781 return PTR_ERR(map);
1782 bpf_map_write_active_inc(map);
1783 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1784 err = -EPERM;
1785 goto err_put;
1786 }
1787
1788 err = bpf_map_check_op_flags(map, attr->flags, ~0);
1789 if (err)
1790 goto err_put;
1791
1792 key = ___bpf_copy_key(ukey, map->key_size);
1793 if (IS_ERR(key)) {
1794 err = PTR_ERR(key);
1795 goto err_put;
1796 }
1797
1798 value_size = bpf_map_value_size(map, attr->flags);
1799 value = kvmemdup_bpfptr(uvalue, value_size);
1800 if (IS_ERR(value)) {
1801 err = PTR_ERR(value);
1802 goto free_key;
1803 }
1804
1805 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1806 if (!err)
1807 maybe_wait_bpf_programs(map);
1808
1809 kvfree(value);
1810 free_key:
1811 kvfree(key);
1812 err_put:
1813 bpf_map_write_active_dec(map);
1814 return err;
1815 }
1816
1817 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1818
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1819 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1820 {
1821 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1822 struct bpf_map *map;
1823 void *key;
1824 int err;
1825
1826 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1827 return -EINVAL;
1828
1829 CLASS(fd, f)(attr->map_fd);
1830 map = __bpf_map_get(f);
1831 if (IS_ERR(map))
1832 return PTR_ERR(map);
1833 bpf_map_write_active_inc(map);
1834 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1835 err = -EPERM;
1836 goto err_put;
1837 }
1838
1839 key = ___bpf_copy_key(ukey, map->key_size);
1840 if (IS_ERR(key)) {
1841 err = PTR_ERR(key);
1842 goto err_put;
1843 }
1844
1845 if (bpf_map_is_offloaded(map)) {
1846 err = bpf_map_offload_delete_elem(map, key);
1847 goto out;
1848 } else if (IS_FD_PROG_ARRAY(map) ||
1849 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1850 /* These maps require sleepable context */
1851 err = map->ops->map_delete_elem(map, key);
1852 goto out;
1853 }
1854
1855 bpf_disable_instrumentation();
1856 rcu_read_lock();
1857 err = map->ops->map_delete_elem(map, key);
1858 rcu_read_unlock();
1859 bpf_enable_instrumentation();
1860 if (!err)
1861 maybe_wait_bpf_programs(map);
1862 out:
1863 kvfree(key);
1864 err_put:
1865 bpf_map_write_active_dec(map);
1866 return err;
1867 }
1868
1869 /* last field in 'union bpf_attr' used by this command */
1870 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1871
map_get_next_key(union bpf_attr * attr)1872 static int map_get_next_key(union bpf_attr *attr)
1873 {
1874 void __user *ukey = u64_to_user_ptr(attr->key);
1875 void __user *unext_key = u64_to_user_ptr(attr->next_key);
1876 struct bpf_map *map;
1877 void *key, *next_key;
1878 int err;
1879
1880 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1881 return -EINVAL;
1882
1883 CLASS(fd, f)(attr->map_fd);
1884 map = __bpf_map_get(f);
1885 if (IS_ERR(map))
1886 return PTR_ERR(map);
1887 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1888 return -EPERM;
1889
1890 if (ukey) {
1891 key = __bpf_copy_key(ukey, map->key_size);
1892 if (IS_ERR(key))
1893 return PTR_ERR(key);
1894 } else {
1895 key = NULL;
1896 }
1897
1898 err = -ENOMEM;
1899 next_key = kvmalloc(map->key_size, GFP_USER);
1900 if (!next_key)
1901 goto free_key;
1902
1903 if (bpf_map_is_offloaded(map)) {
1904 err = bpf_map_offload_get_next_key(map, key, next_key);
1905 goto out;
1906 }
1907
1908 rcu_read_lock();
1909 err = map->ops->map_get_next_key(map, key, next_key);
1910 rcu_read_unlock();
1911 out:
1912 if (err)
1913 goto free_next_key;
1914
1915 err = -EFAULT;
1916 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1917 goto free_next_key;
1918
1919 err = 0;
1920
1921 free_next_key:
1922 kvfree(next_key);
1923 free_key:
1924 kvfree(key);
1925 return err;
1926 }
1927
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1928 int generic_map_delete_batch(struct bpf_map *map,
1929 const union bpf_attr *attr,
1930 union bpf_attr __user *uattr)
1931 {
1932 void __user *keys = u64_to_user_ptr(attr->batch.keys);
1933 u32 cp, max_count;
1934 int err = 0;
1935 void *key;
1936
1937 if (attr->batch.elem_flags & ~BPF_F_LOCK)
1938 return -EINVAL;
1939
1940 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1941 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1942 return -EINVAL;
1943 }
1944
1945 max_count = attr->batch.count;
1946 if (!max_count)
1947 return 0;
1948
1949 if (put_user(0, &uattr->batch.count))
1950 return -EFAULT;
1951
1952 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1953 if (!key)
1954 return -ENOMEM;
1955
1956 for (cp = 0; cp < max_count; cp++) {
1957 err = -EFAULT;
1958 if (copy_from_user(key, keys + cp * map->key_size,
1959 map->key_size))
1960 break;
1961
1962 if (bpf_map_is_offloaded(map)) {
1963 err = bpf_map_offload_delete_elem(map, key);
1964 break;
1965 }
1966
1967 bpf_disable_instrumentation();
1968 rcu_read_lock();
1969 err = map->ops->map_delete_elem(map, key);
1970 rcu_read_unlock();
1971 bpf_enable_instrumentation();
1972 if (err)
1973 break;
1974 cond_resched();
1975 }
1976 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1977 err = -EFAULT;
1978
1979 kvfree(key);
1980
1981 return err;
1982 }
1983
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1984 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1985 const union bpf_attr *attr,
1986 union bpf_attr __user *uattr)
1987 {
1988 void __user *values = u64_to_user_ptr(attr->batch.values);
1989 void __user *keys = u64_to_user_ptr(attr->batch.keys);
1990 u32 value_size, cp, max_count;
1991 void *key, *value;
1992 int err = 0;
1993
1994 err = bpf_map_check_op_flags(map, attr->batch.elem_flags,
1995 BPF_F_LOCK | BPF_F_CPU | BPF_F_ALL_CPUS);
1996 if (err)
1997 return err;
1998
1999 value_size = bpf_map_value_size(map, attr->batch.elem_flags);
2000
2001 max_count = attr->batch.count;
2002 if (!max_count)
2003 return 0;
2004
2005 if (put_user(0, &uattr->batch.count))
2006 return -EFAULT;
2007
2008 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2009 if (!key)
2010 return -ENOMEM;
2011
2012 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2013 if (!value) {
2014 kvfree(key);
2015 return -ENOMEM;
2016 }
2017
2018 for (cp = 0; cp < max_count; cp++) {
2019 err = -EFAULT;
2020 if (copy_from_user(key, keys + cp * map->key_size,
2021 map->key_size) ||
2022 copy_from_user(value, values + cp * value_size, value_size))
2023 break;
2024
2025 err = bpf_map_update_value(map, map_file, key, value,
2026 attr->batch.elem_flags);
2027
2028 if (err)
2029 break;
2030 cond_resched();
2031 }
2032
2033 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
2034 err = -EFAULT;
2035
2036 kvfree(value);
2037 kvfree(key);
2038
2039 return err;
2040 }
2041
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)2042 int generic_map_lookup_batch(struct bpf_map *map,
2043 const union bpf_attr *attr,
2044 union bpf_attr __user *uattr)
2045 {
2046 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
2047 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
2048 void __user *values = u64_to_user_ptr(attr->batch.values);
2049 void __user *keys = u64_to_user_ptr(attr->batch.keys);
2050 void *buf, *buf_prevkey, *prev_key, *key, *value;
2051 u32 value_size, cp, max_count;
2052 int err;
2053
2054 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK | BPF_F_CPU);
2055 if (err)
2056 return err;
2057
2058 value_size = bpf_map_value_size(map, attr->batch.elem_flags);
2059
2060 max_count = attr->batch.count;
2061 if (!max_count)
2062 return 0;
2063
2064 if (put_user(0, &uattr->batch.count))
2065 return -EFAULT;
2066
2067 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2068 if (!buf_prevkey)
2069 return -ENOMEM;
2070
2071 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2072 if (!buf) {
2073 kvfree(buf_prevkey);
2074 return -ENOMEM;
2075 }
2076
2077 err = -EFAULT;
2078 prev_key = NULL;
2079 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2080 goto free_buf;
2081 key = buf;
2082 value = key + map->key_size;
2083 if (ubatch)
2084 prev_key = buf_prevkey;
2085
2086 for (cp = 0; cp < max_count;) {
2087 rcu_read_lock();
2088 err = map->ops->map_get_next_key(map, prev_key, key);
2089 rcu_read_unlock();
2090 if (err)
2091 break;
2092 err = bpf_map_copy_value(map, key, value,
2093 attr->batch.elem_flags);
2094
2095 if (err == -ENOENT)
2096 goto next_key;
2097
2098 if (err)
2099 goto free_buf;
2100
2101 if (copy_to_user(keys + cp * map->key_size, key,
2102 map->key_size)) {
2103 err = -EFAULT;
2104 goto free_buf;
2105 }
2106 if (copy_to_user(values + cp * value_size, value, value_size)) {
2107 err = -EFAULT;
2108 goto free_buf;
2109 }
2110
2111 cp++;
2112 next_key:
2113 if (!prev_key)
2114 prev_key = buf_prevkey;
2115
2116 swap(prev_key, key);
2117 cond_resched();
2118 }
2119
2120 if (err == -EFAULT)
2121 goto free_buf;
2122
2123 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2124 (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2125 err = -EFAULT;
2126
2127 free_buf:
2128 kvfree(buf_prevkey);
2129 kvfree(buf);
2130 return err;
2131 }
2132
2133 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2134
map_lookup_and_delete_elem(union bpf_attr * attr)2135 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2136 {
2137 void __user *ukey = u64_to_user_ptr(attr->key);
2138 void __user *uvalue = u64_to_user_ptr(attr->value);
2139 struct bpf_map *map;
2140 void *key, *value;
2141 u32 value_size;
2142 int err;
2143
2144 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2145 return -EINVAL;
2146
2147 if (attr->flags & ~BPF_F_LOCK)
2148 return -EINVAL;
2149
2150 CLASS(fd, f)(attr->map_fd);
2151 map = __bpf_map_get(f);
2152 if (IS_ERR(map))
2153 return PTR_ERR(map);
2154 bpf_map_write_active_inc(map);
2155 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2156 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2157 err = -EPERM;
2158 goto err_put;
2159 }
2160
2161 if (attr->flags &&
2162 (map->map_type == BPF_MAP_TYPE_QUEUE ||
2163 map->map_type == BPF_MAP_TYPE_STACK)) {
2164 err = -EINVAL;
2165 goto err_put;
2166 }
2167
2168 if ((attr->flags & BPF_F_LOCK) &&
2169 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2170 err = -EINVAL;
2171 goto err_put;
2172 }
2173
2174 key = __bpf_copy_key(ukey, map->key_size);
2175 if (IS_ERR(key)) {
2176 err = PTR_ERR(key);
2177 goto err_put;
2178 }
2179
2180 value_size = bpf_map_value_size(map, 0);
2181
2182 err = -ENOMEM;
2183 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2184 if (!value)
2185 goto free_key;
2186
2187 err = -ENOTSUPP;
2188 if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2189 map->map_type == BPF_MAP_TYPE_STACK) {
2190 err = map->ops->map_pop_elem(map, value);
2191 } else if (map->map_type == BPF_MAP_TYPE_HASH ||
2192 map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2193 map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2194 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
2195 map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
2196 if (!bpf_map_is_offloaded(map)) {
2197 bpf_disable_instrumentation();
2198 rcu_read_lock();
2199 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2200 rcu_read_unlock();
2201 bpf_enable_instrumentation();
2202 }
2203 }
2204
2205 if (err)
2206 goto free_value;
2207
2208 if (copy_to_user(uvalue, value, value_size) != 0) {
2209 err = -EFAULT;
2210 goto free_value;
2211 }
2212
2213 err = 0;
2214
2215 free_value:
2216 kvfree(value);
2217 free_key:
2218 kvfree(key);
2219 err_put:
2220 bpf_map_write_active_dec(map);
2221 return err;
2222 }
2223
2224 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2225
map_freeze(const union bpf_attr * attr)2226 static int map_freeze(const union bpf_attr *attr)
2227 {
2228 int err = 0;
2229 struct bpf_map *map;
2230
2231 if (CHECK_ATTR(BPF_MAP_FREEZE))
2232 return -EINVAL;
2233
2234 CLASS(fd, f)(attr->map_fd);
2235 map = __bpf_map_get(f);
2236 if (IS_ERR(map))
2237 return PTR_ERR(map);
2238
2239 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2240 return -ENOTSUPP;
2241
2242 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2243 return -EPERM;
2244
2245 mutex_lock(&map->freeze_mutex);
2246 if (bpf_map_write_active(map)) {
2247 err = -EBUSY;
2248 goto err_put;
2249 }
2250 if (READ_ONCE(map->frozen)) {
2251 err = -EBUSY;
2252 goto err_put;
2253 }
2254
2255 WRITE_ONCE(map->frozen, true);
2256 err_put:
2257 mutex_unlock(&map->freeze_mutex);
2258 return err;
2259 }
2260
2261 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2262 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2263 [_id] = & _name ## _prog_ops,
2264 #define BPF_MAP_TYPE(_id, _ops)
2265 #define BPF_LINK_TYPE(_id, _name)
2266 #include <linux/bpf_types.h>
2267 #undef BPF_PROG_TYPE
2268 #undef BPF_MAP_TYPE
2269 #undef BPF_LINK_TYPE
2270 };
2271
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2272 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2273 {
2274 const struct bpf_prog_ops *ops;
2275
2276 if (type >= ARRAY_SIZE(bpf_prog_types))
2277 return -EINVAL;
2278 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2279 ops = bpf_prog_types[type];
2280 if (!ops)
2281 return -EINVAL;
2282
2283 if (!bpf_prog_is_offloaded(prog->aux))
2284 prog->aux->ops = ops;
2285 else
2286 prog->aux->ops = &bpf_offload_prog_ops;
2287 prog->type = type;
2288 return 0;
2289 }
2290
2291 enum bpf_audit {
2292 BPF_AUDIT_LOAD,
2293 BPF_AUDIT_UNLOAD,
2294 BPF_AUDIT_MAX,
2295 };
2296
2297 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2298 [BPF_AUDIT_LOAD] = "LOAD",
2299 [BPF_AUDIT_UNLOAD] = "UNLOAD",
2300 };
2301
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2302 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2303 {
2304 struct audit_context *ctx = NULL;
2305 struct audit_buffer *ab;
2306
2307 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2308 return;
2309 if (audit_enabled == AUDIT_OFF)
2310 return;
2311 if (!in_hardirq() && !irqs_disabled())
2312 ctx = audit_context();
2313 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2314 if (unlikely(!ab))
2315 return;
2316 audit_log_format(ab, "prog-id=%u op=%s",
2317 prog->aux->id, bpf_audit_str[op]);
2318 audit_log_end(ab);
2319 }
2320
bpf_prog_alloc_id(struct bpf_prog * prog)2321 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2322 {
2323 int id;
2324
2325 idr_preload(GFP_KERNEL);
2326 spin_lock_bh(&prog_idr_lock);
2327 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2328 if (id > 0)
2329 prog->aux->id = id;
2330 spin_unlock_bh(&prog_idr_lock);
2331 idr_preload_end();
2332
2333 /* id is in [1, INT_MAX) */
2334 if (WARN_ON_ONCE(!id))
2335 return -ENOSPC;
2336
2337 return id > 0 ? 0 : id;
2338 }
2339
bpf_prog_free_id(struct bpf_prog * prog)2340 void bpf_prog_free_id(struct bpf_prog *prog)
2341 {
2342 unsigned long flags;
2343
2344 /* cBPF to eBPF migrations are currently not in the idr store.
2345 * Offloaded programs are removed from the store when their device
2346 * disappears - even if someone grabs an fd to them they are unusable,
2347 * simply waiting for refcnt to drop to be freed.
2348 */
2349 if (!prog->aux->id)
2350 return;
2351
2352 spin_lock_irqsave(&prog_idr_lock, flags);
2353 idr_remove(&prog_idr, prog->aux->id);
2354 prog->aux->id = 0;
2355 spin_unlock_irqrestore(&prog_idr_lock, flags);
2356 }
2357
__bpf_prog_put_rcu(struct rcu_head * rcu)2358 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2359 {
2360 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2361
2362 kvfree(aux->func_info);
2363 kfree(aux->func_info_aux);
2364 free_uid(aux->user);
2365 security_bpf_prog_free(aux->prog);
2366 bpf_prog_free(aux->prog);
2367 }
2368
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2369 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2370 {
2371 bpf_prog_kallsyms_del_all(prog);
2372 btf_put(prog->aux->btf);
2373 module_put(prog->aux->mod);
2374 kvfree(prog->aux->jited_linfo);
2375 kvfree(prog->aux->linfo);
2376 kfree(prog->aux->kfunc_tab);
2377 kfree(prog->aux->ctx_arg_info);
2378 if (prog->aux->attach_btf)
2379 btf_put(prog->aux->attach_btf);
2380
2381 if (deferred) {
2382 if (prog->sleepable)
2383 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2384 else
2385 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2386 } else {
2387 __bpf_prog_put_rcu(&prog->aux->rcu);
2388 }
2389 }
2390
bpf_prog_put_deferred(struct work_struct * work)2391 static void bpf_prog_put_deferred(struct work_struct *work)
2392 {
2393 struct bpf_prog_aux *aux;
2394 struct bpf_prog *prog;
2395
2396 aux = container_of(work, struct bpf_prog_aux, work);
2397 prog = aux->prog;
2398 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2399 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2400 bpf_prog_free_id(prog);
2401 __bpf_prog_put_noref(prog, true);
2402 }
2403
__bpf_prog_put(struct bpf_prog * prog)2404 static void __bpf_prog_put(struct bpf_prog *prog)
2405 {
2406 struct bpf_prog_aux *aux = prog->aux;
2407
2408 if (atomic64_dec_and_test(&aux->refcnt)) {
2409 if (in_hardirq() || irqs_disabled()) {
2410 INIT_WORK(&aux->work, bpf_prog_put_deferred);
2411 schedule_work(&aux->work);
2412 } else {
2413 bpf_prog_put_deferred(&aux->work);
2414 }
2415 }
2416 }
2417
bpf_prog_put(struct bpf_prog * prog)2418 void bpf_prog_put(struct bpf_prog *prog)
2419 {
2420 __bpf_prog_put(prog);
2421 }
2422 EXPORT_SYMBOL_GPL(bpf_prog_put);
2423
bpf_prog_release(struct inode * inode,struct file * filp)2424 static int bpf_prog_release(struct inode *inode, struct file *filp)
2425 {
2426 struct bpf_prog *prog = filp->private_data;
2427
2428 bpf_prog_put(prog);
2429 return 0;
2430 }
2431
2432 struct bpf_prog_kstats {
2433 u64 nsecs;
2434 u64 cnt;
2435 u64 misses;
2436 };
2437
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2438 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2439 {
2440 struct bpf_prog_stats *stats;
2441 unsigned int flags;
2442
2443 if (unlikely(!prog->stats))
2444 return;
2445
2446 stats = this_cpu_ptr(prog->stats);
2447 flags = u64_stats_update_begin_irqsave(&stats->syncp);
2448 u64_stats_inc(&stats->misses);
2449 u64_stats_update_end_irqrestore(&stats->syncp, flags);
2450 }
2451
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2452 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2453 struct bpf_prog_kstats *stats)
2454 {
2455 u64 nsecs = 0, cnt = 0, misses = 0;
2456 int cpu;
2457
2458 for_each_possible_cpu(cpu) {
2459 const struct bpf_prog_stats *st;
2460 unsigned int start;
2461 u64 tnsecs, tcnt, tmisses;
2462
2463 st = per_cpu_ptr(prog->stats, cpu);
2464 do {
2465 start = u64_stats_fetch_begin(&st->syncp);
2466 tnsecs = u64_stats_read(&st->nsecs);
2467 tcnt = u64_stats_read(&st->cnt);
2468 tmisses = u64_stats_read(&st->misses);
2469 } while (u64_stats_fetch_retry(&st->syncp, start));
2470 nsecs += tnsecs;
2471 cnt += tcnt;
2472 misses += tmisses;
2473 }
2474 stats->nsecs = nsecs;
2475 stats->cnt = cnt;
2476 stats->misses = misses;
2477 }
2478
2479 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2480 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2481 {
2482 const struct bpf_prog *prog = filp->private_data;
2483 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2484 struct bpf_prog_kstats stats;
2485
2486 bpf_prog_get_stats(prog, &stats);
2487 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2488 seq_printf(m,
2489 "prog_type:\t%u\n"
2490 "prog_jited:\t%u\n"
2491 "prog_tag:\t%s\n"
2492 "memlock:\t%llu\n"
2493 "prog_id:\t%u\n"
2494 "run_time_ns:\t%llu\n"
2495 "run_cnt:\t%llu\n"
2496 "recursion_misses:\t%llu\n"
2497 "verified_insns:\t%u\n",
2498 prog->type,
2499 prog->jited,
2500 prog_tag,
2501 prog->pages * 1ULL << PAGE_SHIFT,
2502 prog->aux->id,
2503 stats.nsecs,
2504 stats.cnt,
2505 stats.misses,
2506 prog->aux->verified_insns);
2507 }
2508 #endif
2509
2510 const struct file_operations bpf_prog_fops = {
2511 #ifdef CONFIG_PROC_FS
2512 .show_fdinfo = bpf_prog_show_fdinfo,
2513 #endif
2514 .release = bpf_prog_release,
2515 .read = bpf_dummy_read,
2516 .write = bpf_dummy_write,
2517 };
2518
bpf_prog_new_fd(struct bpf_prog * prog)2519 int bpf_prog_new_fd(struct bpf_prog *prog)
2520 {
2521 int ret;
2522
2523 ret = security_bpf_prog(prog);
2524 if (ret < 0)
2525 return ret;
2526
2527 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2528 O_RDWR | O_CLOEXEC);
2529 }
2530
bpf_prog_add(struct bpf_prog * prog,int i)2531 void bpf_prog_add(struct bpf_prog *prog, int i)
2532 {
2533 atomic64_add(i, &prog->aux->refcnt);
2534 }
2535 EXPORT_SYMBOL_GPL(bpf_prog_add);
2536
bpf_prog_sub(struct bpf_prog * prog,int i)2537 void bpf_prog_sub(struct bpf_prog *prog, int i)
2538 {
2539 /* Only to be used for undoing previous bpf_prog_add() in some
2540 * error path. We still know that another entity in our call
2541 * path holds a reference to the program, thus atomic_sub() can
2542 * be safely used in such cases!
2543 */
2544 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2545 }
2546 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2547
bpf_prog_inc(struct bpf_prog * prog)2548 void bpf_prog_inc(struct bpf_prog *prog)
2549 {
2550 atomic64_inc(&prog->aux->refcnt);
2551 }
2552 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2553
2554 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2555 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2556 {
2557 int refold;
2558
2559 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2560
2561 if (!refold)
2562 return ERR_PTR(-ENOENT);
2563
2564 return prog;
2565 }
2566 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2567
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2568 bool bpf_prog_get_ok(struct bpf_prog *prog,
2569 enum bpf_prog_type *attach_type, bool attach_drv)
2570 {
2571 /* not an attachment, just a refcount inc, always allow */
2572 if (!attach_type)
2573 return true;
2574
2575 if (prog->type != *attach_type)
2576 return false;
2577 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2578 return false;
2579
2580 return true;
2581 }
2582
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2583 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2584 bool attach_drv)
2585 {
2586 CLASS(fd, f)(ufd);
2587 struct bpf_prog *prog;
2588
2589 if (fd_empty(f))
2590 return ERR_PTR(-EBADF);
2591 if (fd_file(f)->f_op != &bpf_prog_fops)
2592 return ERR_PTR(-EINVAL);
2593
2594 prog = fd_file(f)->private_data;
2595 if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2596 return ERR_PTR(-EINVAL);
2597
2598 bpf_prog_inc(prog);
2599 return prog;
2600 }
2601
bpf_prog_get(u32 ufd)2602 struct bpf_prog *bpf_prog_get(u32 ufd)
2603 {
2604 return __bpf_prog_get(ufd, NULL, false);
2605 }
2606
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2607 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2608 bool attach_drv)
2609 {
2610 return __bpf_prog_get(ufd, &type, attach_drv);
2611 }
2612 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2613
2614 /* Initially all BPF programs could be loaded w/o specifying
2615 * expected_attach_type. Later for some of them specifying expected_attach_type
2616 * at load time became required so that program could be validated properly.
2617 * Programs of types that are allowed to be loaded both w/ and w/o (for
2618 * backward compatibility) expected_attach_type, should have the default attach
2619 * type assigned to expected_attach_type for the latter case, so that it can be
2620 * validated later at attach time.
2621 *
2622 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2623 * prog type requires it but has some attach types that have to be backward
2624 * compatible.
2625 */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2626 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2627 {
2628 switch (attr->prog_type) {
2629 case BPF_PROG_TYPE_CGROUP_SOCK:
2630 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2631 * exist so checking for non-zero is the way to go here.
2632 */
2633 if (!attr->expected_attach_type)
2634 attr->expected_attach_type =
2635 BPF_CGROUP_INET_SOCK_CREATE;
2636 break;
2637 case BPF_PROG_TYPE_SK_REUSEPORT:
2638 if (!attr->expected_attach_type)
2639 attr->expected_attach_type =
2640 BPF_SK_REUSEPORT_SELECT;
2641 break;
2642 }
2643 }
2644
2645 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)2646 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2647 enum bpf_attach_type expected_attach_type,
2648 struct btf *attach_btf, u32 btf_id,
2649 struct bpf_prog *dst_prog)
2650 {
2651 if (btf_id) {
2652 if (btf_id > BTF_MAX_TYPE)
2653 return -EINVAL;
2654
2655 if (!attach_btf && !dst_prog)
2656 return -EINVAL;
2657
2658 switch (prog_type) {
2659 case BPF_PROG_TYPE_TRACING:
2660 case BPF_PROG_TYPE_LSM:
2661 case BPF_PROG_TYPE_STRUCT_OPS:
2662 case BPF_PROG_TYPE_EXT:
2663 break;
2664 default:
2665 return -EINVAL;
2666 }
2667 }
2668
2669 if (attach_btf && (!btf_id || dst_prog))
2670 return -EINVAL;
2671
2672 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2673 prog_type != BPF_PROG_TYPE_EXT)
2674 return -EINVAL;
2675
2676 switch (prog_type) {
2677 case BPF_PROG_TYPE_CGROUP_SOCK:
2678 switch (expected_attach_type) {
2679 case BPF_CGROUP_INET_SOCK_CREATE:
2680 case BPF_CGROUP_INET_SOCK_RELEASE:
2681 case BPF_CGROUP_INET4_POST_BIND:
2682 case BPF_CGROUP_INET6_POST_BIND:
2683 return 0;
2684 default:
2685 return -EINVAL;
2686 }
2687 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2688 switch (expected_attach_type) {
2689 case BPF_CGROUP_INET4_BIND:
2690 case BPF_CGROUP_INET6_BIND:
2691 case BPF_CGROUP_INET4_CONNECT:
2692 case BPF_CGROUP_INET6_CONNECT:
2693 case BPF_CGROUP_UNIX_CONNECT:
2694 case BPF_CGROUP_INET4_GETPEERNAME:
2695 case BPF_CGROUP_INET6_GETPEERNAME:
2696 case BPF_CGROUP_UNIX_GETPEERNAME:
2697 case BPF_CGROUP_INET4_GETSOCKNAME:
2698 case BPF_CGROUP_INET6_GETSOCKNAME:
2699 case BPF_CGROUP_UNIX_GETSOCKNAME:
2700 case BPF_CGROUP_UDP4_SENDMSG:
2701 case BPF_CGROUP_UDP6_SENDMSG:
2702 case BPF_CGROUP_UNIX_SENDMSG:
2703 case BPF_CGROUP_UDP4_RECVMSG:
2704 case BPF_CGROUP_UDP6_RECVMSG:
2705 case BPF_CGROUP_UNIX_RECVMSG:
2706 return 0;
2707 default:
2708 return -EINVAL;
2709 }
2710 case BPF_PROG_TYPE_CGROUP_SKB:
2711 switch (expected_attach_type) {
2712 case BPF_CGROUP_INET_INGRESS:
2713 case BPF_CGROUP_INET_EGRESS:
2714 return 0;
2715 default:
2716 return -EINVAL;
2717 }
2718 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2719 switch (expected_attach_type) {
2720 case BPF_CGROUP_SETSOCKOPT:
2721 case BPF_CGROUP_GETSOCKOPT:
2722 return 0;
2723 default:
2724 return -EINVAL;
2725 }
2726 case BPF_PROG_TYPE_SK_LOOKUP:
2727 if (expected_attach_type == BPF_SK_LOOKUP)
2728 return 0;
2729 return -EINVAL;
2730 case BPF_PROG_TYPE_SK_REUSEPORT:
2731 switch (expected_attach_type) {
2732 case BPF_SK_REUSEPORT_SELECT:
2733 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2734 return 0;
2735 default:
2736 return -EINVAL;
2737 }
2738 case BPF_PROG_TYPE_NETFILTER:
2739 if (expected_attach_type == BPF_NETFILTER)
2740 return 0;
2741 return -EINVAL;
2742 case BPF_PROG_TYPE_SYSCALL:
2743 case BPF_PROG_TYPE_EXT:
2744 if (expected_attach_type)
2745 return -EINVAL;
2746 fallthrough;
2747 default:
2748 return 0;
2749 }
2750 }
2751
is_net_admin_prog_type(enum bpf_prog_type prog_type)2752 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2753 {
2754 switch (prog_type) {
2755 case BPF_PROG_TYPE_SCHED_CLS:
2756 case BPF_PROG_TYPE_SCHED_ACT:
2757 case BPF_PROG_TYPE_XDP:
2758 case BPF_PROG_TYPE_LWT_IN:
2759 case BPF_PROG_TYPE_LWT_OUT:
2760 case BPF_PROG_TYPE_LWT_XMIT:
2761 case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2762 case BPF_PROG_TYPE_SK_SKB:
2763 case BPF_PROG_TYPE_SK_MSG:
2764 case BPF_PROG_TYPE_FLOW_DISSECTOR:
2765 case BPF_PROG_TYPE_CGROUP_DEVICE:
2766 case BPF_PROG_TYPE_CGROUP_SOCK:
2767 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2768 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2769 case BPF_PROG_TYPE_CGROUP_SYSCTL:
2770 case BPF_PROG_TYPE_SOCK_OPS:
2771 case BPF_PROG_TYPE_EXT: /* extends any prog */
2772 case BPF_PROG_TYPE_NETFILTER:
2773 return true;
2774 case BPF_PROG_TYPE_CGROUP_SKB:
2775 /* always unpriv */
2776 case BPF_PROG_TYPE_SK_REUSEPORT:
2777 /* equivalent to SOCKET_FILTER. need CAP_BPF only */
2778 default:
2779 return false;
2780 }
2781 }
2782
is_perfmon_prog_type(enum bpf_prog_type prog_type)2783 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2784 {
2785 switch (prog_type) {
2786 case BPF_PROG_TYPE_KPROBE:
2787 case BPF_PROG_TYPE_TRACEPOINT:
2788 case BPF_PROG_TYPE_PERF_EVENT:
2789 case BPF_PROG_TYPE_RAW_TRACEPOINT:
2790 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2791 case BPF_PROG_TYPE_TRACING:
2792 case BPF_PROG_TYPE_LSM:
2793 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2794 case BPF_PROG_TYPE_EXT: /* extends any prog */
2795 return true;
2796 default:
2797 return false;
2798 }
2799 }
2800
bpf_prog_verify_signature(struct bpf_prog * prog,union bpf_attr * attr,bool is_kernel)2801 static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr,
2802 bool is_kernel)
2803 {
2804 bpfptr_t usig = make_bpfptr(attr->signature, is_kernel);
2805 struct bpf_dynptr_kern sig_ptr, insns_ptr;
2806 struct bpf_key *key = NULL;
2807 void *sig;
2808 int err = 0;
2809
2810 /*
2811 * Don't attempt to use kmalloc_large or vmalloc for signatures.
2812 * Practical signature for BPF program should be below this limit.
2813 */
2814 if (attr->signature_size > KMALLOC_MAX_CACHE_SIZE)
2815 return -EINVAL;
2816
2817 if (system_keyring_id_check(attr->keyring_id) == 0)
2818 key = bpf_lookup_system_key(attr->keyring_id);
2819 else
2820 key = bpf_lookup_user_key(attr->keyring_id, 0);
2821
2822 if (!key)
2823 return -EINVAL;
2824
2825 sig = kvmemdup_bpfptr(usig, attr->signature_size);
2826 if (IS_ERR(sig)) {
2827 bpf_key_put(key);
2828 return PTR_ERR(sig);
2829 }
2830
2831 bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0,
2832 attr->signature_size);
2833 bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0,
2834 prog->len * sizeof(struct bpf_insn));
2835
2836 err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr,
2837 (struct bpf_dynptr *)&sig_ptr, key);
2838
2839 bpf_key_put(key);
2840 kvfree(sig);
2841 return err;
2842 }
2843
bpf_prog_mark_insn_arrays_ready(struct bpf_prog * prog)2844 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog)
2845 {
2846 int err;
2847 int i;
2848
2849 for (i = 0; i < prog->aux->used_map_cnt; i++) {
2850 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY)
2851 continue;
2852
2853 err = bpf_insn_array_ready(prog->aux->used_maps[i]);
2854 if (err)
2855 return err;
2856 }
2857
2858 return 0;
2859 }
2860
2861 /* last field in 'union bpf_attr' used by this command */
2862 #define BPF_PROG_LOAD_LAST_FIELD keyring_id
2863
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2864 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2865 {
2866 enum bpf_prog_type type = attr->prog_type;
2867 struct bpf_prog *prog, *dst_prog = NULL;
2868 struct btf *attach_btf = NULL;
2869 struct bpf_token *token = NULL;
2870 bool bpf_cap;
2871 int err;
2872 char license[128];
2873
2874 if (CHECK_ATTR(BPF_PROG_LOAD))
2875 return -EINVAL;
2876
2877 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2878 BPF_F_ANY_ALIGNMENT |
2879 BPF_F_TEST_STATE_FREQ |
2880 BPF_F_SLEEPABLE |
2881 BPF_F_TEST_RND_HI32 |
2882 BPF_F_XDP_HAS_FRAGS |
2883 BPF_F_XDP_DEV_BOUND_ONLY |
2884 BPF_F_TEST_REG_INVARIANTS |
2885 BPF_F_TOKEN_FD))
2886 return -EINVAL;
2887
2888 bpf_prog_load_fixup_attach_type(attr);
2889
2890 if (attr->prog_flags & BPF_F_TOKEN_FD) {
2891 token = bpf_token_get_from_fd(attr->prog_token_fd);
2892 if (IS_ERR(token))
2893 return PTR_ERR(token);
2894 /* if current token doesn't grant prog loading permissions,
2895 * then we can't use this token, so ignore it and rely on
2896 * system-wide capabilities checks
2897 */
2898 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2899 !bpf_token_allow_prog_type(token, attr->prog_type,
2900 attr->expected_attach_type)) {
2901 bpf_token_put(token);
2902 token = NULL;
2903 }
2904 }
2905
2906 bpf_cap = bpf_token_capable(token, CAP_BPF);
2907 err = -EPERM;
2908
2909 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2910 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2911 !bpf_cap)
2912 goto put_token;
2913
2914 /* Intent here is for unprivileged_bpf_disabled to block BPF program
2915 * creation for unprivileged users; other actions depend
2916 * on fd availability and access to bpffs, so are dependent on
2917 * object creation success. Even with unprivileged BPF disabled,
2918 * capability checks are still carried out for these
2919 * and other operations.
2920 */
2921 if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2922 goto put_token;
2923
2924 if (attr->insn_cnt == 0 ||
2925 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2926 err = -E2BIG;
2927 goto put_token;
2928 }
2929 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2930 type != BPF_PROG_TYPE_CGROUP_SKB &&
2931 !bpf_cap)
2932 goto put_token;
2933
2934 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2935 goto put_token;
2936 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2937 goto put_token;
2938
2939 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2940 * or btf, we need to check which one it is
2941 */
2942 if (attr->attach_prog_fd) {
2943 dst_prog = bpf_prog_get(attr->attach_prog_fd);
2944 if (IS_ERR(dst_prog)) {
2945 dst_prog = NULL;
2946 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2947 if (IS_ERR(attach_btf)) {
2948 err = -EINVAL;
2949 goto put_token;
2950 }
2951 if (!btf_is_kernel(attach_btf)) {
2952 /* attaching through specifying bpf_prog's BTF
2953 * objects directly might be supported eventually
2954 */
2955 btf_put(attach_btf);
2956 err = -ENOTSUPP;
2957 goto put_token;
2958 }
2959 }
2960 } else if (attr->attach_btf_id) {
2961 /* fall back to vmlinux BTF, if BTF type ID is specified */
2962 attach_btf = bpf_get_btf_vmlinux();
2963 if (IS_ERR(attach_btf)) {
2964 err = PTR_ERR(attach_btf);
2965 goto put_token;
2966 }
2967 if (!attach_btf) {
2968 err = -EINVAL;
2969 goto put_token;
2970 }
2971 btf_get(attach_btf);
2972 }
2973
2974 if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2975 attach_btf, attr->attach_btf_id,
2976 dst_prog)) {
2977 if (dst_prog)
2978 bpf_prog_put(dst_prog);
2979 if (attach_btf)
2980 btf_put(attach_btf);
2981 err = -EINVAL;
2982 goto put_token;
2983 }
2984
2985 /* plain bpf_prog allocation */
2986 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2987 if (!prog) {
2988 if (dst_prog)
2989 bpf_prog_put(dst_prog);
2990 if (attach_btf)
2991 btf_put(attach_btf);
2992 err = -EINVAL;
2993 goto put_token;
2994 }
2995
2996 prog->expected_attach_type = attr->expected_attach_type;
2997 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
2998 prog->aux->attach_btf = attach_btf;
2999 prog->aux->attach_btf_id = attr->attach_btf_id;
3000 prog->aux->dst_prog = dst_prog;
3001 prog->aux->dev_bound = !!attr->prog_ifindex;
3002 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
3003
3004 /* move token into prog->aux, reuse taken refcnt */
3005 prog->aux->token = token;
3006 token = NULL;
3007
3008 prog->aux->user = get_current_user();
3009 prog->len = attr->insn_cnt;
3010
3011 err = -EFAULT;
3012 if (copy_from_bpfptr(prog->insns,
3013 make_bpfptr(attr->insns, uattr.is_kernel),
3014 bpf_prog_insn_size(prog)) != 0)
3015 goto free_prog;
3016 /* copy eBPF program license from user space */
3017 if (strncpy_from_bpfptr(license,
3018 make_bpfptr(attr->license, uattr.is_kernel),
3019 sizeof(license) - 1) < 0)
3020 goto free_prog;
3021 license[sizeof(license) - 1] = 0;
3022
3023 /* eBPF programs must be GPL compatible to use GPL-ed functions */
3024 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
3025
3026 if (attr->signature) {
3027 err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel);
3028 if (err)
3029 goto free_prog;
3030 }
3031
3032 prog->orig_prog = NULL;
3033 prog->jited = 0;
3034
3035 atomic64_set(&prog->aux->refcnt, 1);
3036
3037 if (bpf_prog_is_dev_bound(prog->aux)) {
3038 err = bpf_prog_dev_bound_init(prog, attr);
3039 if (err)
3040 goto free_prog;
3041 }
3042
3043 if (type == BPF_PROG_TYPE_EXT && dst_prog &&
3044 bpf_prog_is_dev_bound(dst_prog->aux)) {
3045 err = bpf_prog_dev_bound_inherit(prog, dst_prog);
3046 if (err)
3047 goto free_prog;
3048 }
3049
3050 /*
3051 * Bookkeeping for managing the program attachment chain.
3052 *
3053 * It might be tempting to set attach_tracing_prog flag at the attachment
3054 * time, but this will not prevent from loading bunch of tracing prog
3055 * first, then attach them one to another.
3056 *
3057 * The flag attach_tracing_prog is set for the whole program lifecycle, and
3058 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
3059 * programs cannot change attachment target.
3060 */
3061 if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
3062 dst_prog->type == BPF_PROG_TYPE_TRACING) {
3063 prog->aux->attach_tracing_prog = true;
3064 }
3065
3066 /* find program type: socket_filter vs tracing_filter */
3067 err = find_prog_type(type, prog);
3068 if (err < 0)
3069 goto free_prog;
3070
3071 prog->aux->load_time = ktime_get_boottime_ns();
3072 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
3073 sizeof(attr->prog_name));
3074 if (err < 0)
3075 goto free_prog;
3076
3077 err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel);
3078 if (err)
3079 goto free_prog_sec;
3080
3081 /* run eBPF verifier */
3082 err = bpf_check(&prog, attr, uattr, uattr_size);
3083 if (err < 0)
3084 goto free_used_maps;
3085
3086 prog = bpf_prog_select_runtime(prog, &err);
3087 if (err < 0)
3088 goto free_used_maps;
3089
3090 err = bpf_prog_mark_insn_arrays_ready(prog);
3091 if (err < 0)
3092 goto free_used_maps;
3093
3094 err = bpf_prog_alloc_id(prog);
3095 if (err)
3096 goto free_used_maps;
3097
3098 /* Upon success of bpf_prog_alloc_id(), the BPF prog is
3099 * effectively publicly exposed. However, retrieving via
3100 * bpf_prog_get_fd_by_id() will take another reference,
3101 * therefore it cannot be gone underneath us.
3102 *
3103 * Only for the time /after/ successful bpf_prog_new_fd()
3104 * and before returning to userspace, we might just hold
3105 * one reference and any parallel close on that fd could
3106 * rip everything out. Hence, below notifications must
3107 * happen before bpf_prog_new_fd().
3108 *
3109 * Also, any failure handling from this point onwards must
3110 * be using bpf_prog_put() given the program is exposed.
3111 */
3112 bpf_prog_kallsyms_add(prog);
3113 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
3114 bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3115
3116 err = bpf_prog_new_fd(prog);
3117 if (err < 0)
3118 bpf_prog_put(prog);
3119 return err;
3120
3121 free_used_maps:
3122 /* In case we have subprogs, we need to wait for a grace
3123 * period before we can tear down JIT memory since symbols
3124 * are already exposed under kallsyms.
3125 */
3126 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3127 return err;
3128
3129 free_prog_sec:
3130 security_bpf_prog_free(prog);
3131 free_prog:
3132 free_uid(prog->aux->user);
3133 if (prog->aux->attach_btf)
3134 btf_put(prog->aux->attach_btf);
3135 bpf_prog_free(prog);
3136 put_token:
3137 bpf_token_put(token);
3138 return err;
3139 }
3140
3141 #define BPF_OBJ_LAST_FIELD path_fd
3142
bpf_obj_pin(const union bpf_attr * attr)3143 static int bpf_obj_pin(const union bpf_attr *attr)
3144 {
3145 int path_fd;
3146
3147 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3148 return -EINVAL;
3149
3150 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3151 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3152 return -EINVAL;
3153
3154 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3155 return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3156 u64_to_user_ptr(attr->pathname));
3157 }
3158
bpf_obj_get(const union bpf_attr * attr)3159 static int bpf_obj_get(const union bpf_attr *attr)
3160 {
3161 int path_fd;
3162
3163 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3164 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3165 return -EINVAL;
3166
3167 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3168 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3169 return -EINVAL;
3170
3171 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3172 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3173 attr->file_flags);
3174 }
3175
3176 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3177 * "sleepable" semantics, which normally would mean that BPF link's attach
3178 * hook can dereference link or link's underlying program for some time after
3179 * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3180 * BPF program itself can be non-sleepable, yet, because it's transitively
3181 * reachable through BPF link, its freeing has to be delayed until after RCU
3182 * Tasks Trace GP.
3183 */
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)3184 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3185 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3186 enum bpf_attach_type attach_type, bool sleepable)
3187 {
3188 WARN_ON(ops->dealloc && ops->dealloc_deferred);
3189 atomic64_set(&link->refcnt, 1);
3190 link->type = type;
3191 link->sleepable = sleepable;
3192 link->id = 0;
3193 link->ops = ops;
3194 link->prog = prog;
3195 link->attach_type = attach_type;
3196 }
3197
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)3198 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3199 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3200 enum bpf_attach_type attach_type)
3201 {
3202 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false);
3203 }
3204
bpf_link_free_id(int id)3205 static void bpf_link_free_id(int id)
3206 {
3207 if (!id)
3208 return;
3209
3210 spin_lock_bh(&link_idr_lock);
3211 idr_remove(&link_idr, id);
3212 spin_unlock_bh(&link_idr_lock);
3213 }
3214
3215 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3216 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3217 * anon_inode's release() call. This helper marks bpf_link as
3218 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3219 * is not decremented, it's the responsibility of a calling code that failed
3220 * to complete bpf_link initialization.
3221 * This helper eventually calls link's dealloc callback, but does not call
3222 * link's release callback.
3223 */
bpf_link_cleanup(struct bpf_link_primer * primer)3224 void bpf_link_cleanup(struct bpf_link_primer *primer)
3225 {
3226 primer->link->prog = NULL;
3227 bpf_link_free_id(primer->id);
3228 fput(primer->file);
3229 put_unused_fd(primer->fd);
3230 }
3231
bpf_link_inc(struct bpf_link * link)3232 void bpf_link_inc(struct bpf_link *link)
3233 {
3234 atomic64_inc(&link->refcnt);
3235 }
3236
bpf_link_dealloc(struct bpf_link * link)3237 static void bpf_link_dealloc(struct bpf_link *link)
3238 {
3239 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3240 if (link->prog)
3241 bpf_prog_put(link->prog);
3242
3243 /* free bpf_link and its containing memory */
3244 if (link->ops->dealloc_deferred)
3245 link->ops->dealloc_deferred(link);
3246 else
3247 link->ops->dealloc(link);
3248 }
3249
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3250 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3251 {
3252 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3253
3254 bpf_link_dealloc(link);
3255 }
3256
bpf_link_is_tracepoint(struct bpf_link * link)3257 static bool bpf_link_is_tracepoint(struct bpf_link *link)
3258 {
3259 /*
3260 * Only these combinations support a tracepoint bpf_link.
3261 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use
3262 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see
3263 * bpf_raw_tp_link_attach().
3264 */
3265 return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT ||
3266 (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP);
3267 }
3268
3269 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3270 static void bpf_link_free(struct bpf_link *link)
3271 {
3272 const struct bpf_link_ops *ops = link->ops;
3273
3274 bpf_link_free_id(link->id);
3275 /* detach BPF program, clean up used resources */
3276 if (link->prog)
3277 ops->release(link);
3278 if (ops->dealloc_deferred) {
3279 /*
3280 * Schedule BPF link deallocation, which will only then
3281 * trigger putting BPF program refcount.
3282 * If underlying BPF program is sleepable or BPF link's target
3283 * attach hookpoint is sleepable or otherwise requires RCU GPs
3284 * to ensure link and its underlying BPF program is not
3285 * reachable anymore, we need to first wait for RCU tasks
3286 * trace sync, and then go through "classic" RCU grace period.
3287 *
3288 * For tracepoint BPF links, we need to go through SRCU grace
3289 * period wait instead when non-faultable tracepoint is used. We
3290 * don't need to chain SRCU grace period waits, however, for the
3291 * faultable case, since it exclusively uses RCU Tasks Trace.
3292 */
3293 if (link->sleepable || (link->prog && link->prog->sleepable))
3294 /* RCU Tasks Trace grace period implies RCU grace period. */
3295 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3296 /* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */
3297 else if (bpf_link_is_tracepoint(link))
3298 call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3299 else
3300 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3301 } else if (ops->dealloc) {
3302 bpf_link_dealloc(link);
3303 }
3304 }
3305
bpf_link_put_deferred(struct work_struct * work)3306 static void bpf_link_put_deferred(struct work_struct *work)
3307 {
3308 struct bpf_link *link = container_of(work, struct bpf_link, work);
3309
3310 bpf_link_free(link);
3311 }
3312
3313 /* bpf_link_put might be called from atomic context. It needs to be called
3314 * from sleepable context in order to acquire sleeping locks during the process.
3315 */
bpf_link_put(struct bpf_link * link)3316 void bpf_link_put(struct bpf_link *link)
3317 {
3318 if (!atomic64_dec_and_test(&link->refcnt))
3319 return;
3320
3321 INIT_WORK(&link->work, bpf_link_put_deferred);
3322 schedule_work(&link->work);
3323 }
3324 EXPORT_SYMBOL(bpf_link_put);
3325
bpf_link_put_direct(struct bpf_link * link)3326 static void bpf_link_put_direct(struct bpf_link *link)
3327 {
3328 if (!atomic64_dec_and_test(&link->refcnt))
3329 return;
3330 bpf_link_free(link);
3331 }
3332
bpf_link_release(struct inode * inode,struct file * filp)3333 static int bpf_link_release(struct inode *inode, struct file *filp)
3334 {
3335 struct bpf_link *link = filp->private_data;
3336
3337 bpf_link_put_direct(link);
3338 return 0;
3339 }
3340
3341 #ifdef CONFIG_PROC_FS
3342 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3343 #define BPF_MAP_TYPE(_id, _ops)
3344 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3345 static const char *bpf_link_type_strs[] = {
3346 [BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3347 #include <linux/bpf_types.h>
3348 };
3349 #undef BPF_PROG_TYPE
3350 #undef BPF_MAP_TYPE
3351 #undef BPF_LINK_TYPE
3352
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3353 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3354 {
3355 const struct bpf_link *link = filp->private_data;
3356 const struct bpf_prog *prog = link->prog;
3357 enum bpf_link_type type = link->type;
3358 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3359
3360 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3361 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI)
3362 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ?
3363 "kretprobe_multi" : "kprobe_multi");
3364 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI)
3365 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ?
3366 "uretprobe_multi" : "uprobe_multi");
3367 else
3368 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3369 } else {
3370 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3371 seq_printf(m, "link_type:\t<%u>\n", type);
3372 }
3373 seq_printf(m, "link_id:\t%u\n", link->id);
3374
3375 if (prog) {
3376 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3377 seq_printf(m,
3378 "prog_tag:\t%s\n"
3379 "prog_id:\t%u\n",
3380 prog_tag,
3381 prog->aux->id);
3382 }
3383 if (link->ops->show_fdinfo)
3384 link->ops->show_fdinfo(link, m);
3385 }
3386 #endif
3387
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3388 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3389 {
3390 struct bpf_link *link = file->private_data;
3391
3392 return link->ops->poll(file, pts);
3393 }
3394
3395 static const struct file_operations bpf_link_fops = {
3396 #ifdef CONFIG_PROC_FS
3397 .show_fdinfo = bpf_link_show_fdinfo,
3398 #endif
3399 .release = bpf_link_release,
3400 .read = bpf_dummy_read,
3401 .write = bpf_dummy_write,
3402 };
3403
3404 static const struct file_operations bpf_link_fops_poll = {
3405 #ifdef CONFIG_PROC_FS
3406 .show_fdinfo = bpf_link_show_fdinfo,
3407 #endif
3408 .release = bpf_link_release,
3409 .read = bpf_dummy_read,
3410 .write = bpf_dummy_write,
3411 .poll = bpf_link_poll,
3412 };
3413
bpf_link_alloc_id(struct bpf_link * link)3414 static int bpf_link_alloc_id(struct bpf_link *link)
3415 {
3416 int id;
3417
3418 idr_preload(GFP_KERNEL);
3419 spin_lock_bh(&link_idr_lock);
3420 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3421 spin_unlock_bh(&link_idr_lock);
3422 idr_preload_end();
3423
3424 return id;
3425 }
3426
3427 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3428 * reserving unused FD and allocating ID from link_idr. This is to be paired
3429 * with bpf_link_settle() to install FD and ID and expose bpf_link to
3430 * user-space, if bpf_link is successfully attached. If not, bpf_link and
3431 * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3432 * transient state is passed around in struct bpf_link_primer.
3433 * This is preferred way to create and initialize bpf_link, especially when
3434 * there are complicated and expensive operations in between creating bpf_link
3435 * itself and attaching it to BPF hook. By using bpf_link_prime() and
3436 * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3437 * expensive (and potentially failing) roll back operations in a rare case
3438 * that file, FD, or ID can't be allocated.
3439 */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3440 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3441 {
3442 struct file *file;
3443 int fd, id;
3444
3445 fd = get_unused_fd_flags(O_CLOEXEC);
3446 if (fd < 0)
3447 return fd;
3448
3449
3450 id = bpf_link_alloc_id(link);
3451 if (id < 0) {
3452 put_unused_fd(fd);
3453 return id;
3454 }
3455
3456 file = anon_inode_getfile("bpf_link",
3457 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3458 link, O_CLOEXEC);
3459 if (IS_ERR(file)) {
3460 bpf_link_free_id(id);
3461 put_unused_fd(fd);
3462 return PTR_ERR(file);
3463 }
3464
3465 primer->link = link;
3466 primer->file = file;
3467 primer->fd = fd;
3468 primer->id = id;
3469 return 0;
3470 }
3471
bpf_link_settle(struct bpf_link_primer * primer)3472 int bpf_link_settle(struct bpf_link_primer *primer)
3473 {
3474 /* make bpf_link fetchable by ID */
3475 spin_lock_bh(&link_idr_lock);
3476 primer->link->id = primer->id;
3477 spin_unlock_bh(&link_idr_lock);
3478 /* make bpf_link fetchable by FD */
3479 fd_install(primer->fd, primer->file);
3480 /* pass through installed FD */
3481 return primer->fd;
3482 }
3483
bpf_link_new_fd(struct bpf_link * link)3484 int bpf_link_new_fd(struct bpf_link *link)
3485 {
3486 return anon_inode_getfd("bpf-link",
3487 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3488 link, O_CLOEXEC);
3489 }
3490
bpf_link_get_from_fd(u32 ufd)3491 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3492 {
3493 CLASS(fd, f)(ufd);
3494 struct bpf_link *link;
3495
3496 if (fd_empty(f))
3497 return ERR_PTR(-EBADF);
3498 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3499 return ERR_PTR(-EINVAL);
3500
3501 link = fd_file(f)->private_data;
3502 bpf_link_inc(link);
3503 return link;
3504 }
3505 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL");
3506
bpf_tracing_link_release(struct bpf_link * link)3507 static void bpf_tracing_link_release(struct bpf_link *link)
3508 {
3509 struct bpf_tracing_link *tr_link =
3510 container_of(link, struct bpf_tracing_link, link.link);
3511
3512 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3513 tr_link->trampoline,
3514 tr_link->tgt_prog));
3515
3516 bpf_trampoline_put(tr_link->trampoline);
3517
3518 /* tgt_prog is NULL if target is a kernel function */
3519 if (tr_link->tgt_prog)
3520 bpf_prog_put(tr_link->tgt_prog);
3521 }
3522
bpf_tracing_link_dealloc(struct bpf_link * link)3523 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3524 {
3525 struct bpf_tracing_link *tr_link =
3526 container_of(link, struct bpf_tracing_link, link.link);
3527
3528 kfree(tr_link);
3529 }
3530
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3531 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3532 struct seq_file *seq)
3533 {
3534 struct bpf_tracing_link *tr_link =
3535 container_of(link, struct bpf_tracing_link, link.link);
3536 u32 target_btf_id, target_obj_id;
3537
3538 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3539 &target_obj_id, &target_btf_id);
3540 seq_printf(seq,
3541 "attach_type:\t%d\n"
3542 "target_obj_id:\t%u\n"
3543 "target_btf_id:\t%u\n"
3544 "cookie:\t%llu\n",
3545 link->attach_type,
3546 target_obj_id,
3547 target_btf_id,
3548 tr_link->link.cookie);
3549 }
3550
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3551 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3552 struct bpf_link_info *info)
3553 {
3554 struct bpf_tracing_link *tr_link =
3555 container_of(link, struct bpf_tracing_link, link.link);
3556
3557 info->tracing.attach_type = link->attach_type;
3558 info->tracing.cookie = tr_link->link.cookie;
3559 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3560 &info->tracing.target_obj_id,
3561 &info->tracing.target_btf_id);
3562
3563 return 0;
3564 }
3565
3566 static const struct bpf_link_ops bpf_tracing_link_lops = {
3567 .release = bpf_tracing_link_release,
3568 .dealloc = bpf_tracing_link_dealloc,
3569 .show_fdinfo = bpf_tracing_link_show_fdinfo,
3570 .fill_link_info = bpf_tracing_link_fill_link_info,
3571 };
3572
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie,enum bpf_attach_type attach_type)3573 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3574 int tgt_prog_fd,
3575 u32 btf_id,
3576 u64 bpf_cookie,
3577 enum bpf_attach_type attach_type)
3578 {
3579 struct bpf_link_primer link_primer;
3580 struct bpf_prog *tgt_prog = NULL;
3581 struct bpf_trampoline *tr = NULL;
3582 struct bpf_tracing_link *link;
3583 u64 key = 0;
3584 int err;
3585
3586 switch (prog->type) {
3587 case BPF_PROG_TYPE_TRACING:
3588 if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3589 prog->expected_attach_type != BPF_TRACE_FEXIT &&
3590 prog->expected_attach_type != BPF_TRACE_FSESSION &&
3591 prog->expected_attach_type != BPF_MODIFY_RETURN) {
3592 err = -EINVAL;
3593 goto out_put_prog;
3594 }
3595 break;
3596 case BPF_PROG_TYPE_EXT:
3597 if (prog->expected_attach_type != 0) {
3598 err = -EINVAL;
3599 goto out_put_prog;
3600 }
3601 break;
3602 case BPF_PROG_TYPE_LSM:
3603 if (prog->expected_attach_type != BPF_LSM_MAC) {
3604 err = -EINVAL;
3605 goto out_put_prog;
3606 }
3607 break;
3608 default:
3609 err = -EINVAL;
3610 goto out_put_prog;
3611 }
3612
3613 if (!!tgt_prog_fd != !!btf_id) {
3614 err = -EINVAL;
3615 goto out_put_prog;
3616 }
3617
3618 if (tgt_prog_fd) {
3619 /*
3620 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3621 * part would be changed to implement the same for
3622 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3623 * attach_tracing_prog flag is set.
3624 */
3625 if (prog->type != BPF_PROG_TYPE_EXT) {
3626 err = -EINVAL;
3627 goto out_put_prog;
3628 }
3629
3630 tgt_prog = bpf_prog_get(tgt_prog_fd);
3631 if (IS_ERR(tgt_prog)) {
3632 err = PTR_ERR(tgt_prog);
3633 tgt_prog = NULL;
3634 goto out_put_prog;
3635 }
3636
3637 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3638 }
3639
3640 if (prog->expected_attach_type == BPF_TRACE_FSESSION) {
3641 struct bpf_fsession_link *fslink;
3642
3643 fslink = kzalloc_obj(*fslink, GFP_USER);
3644 if (fslink) {
3645 bpf_link_init(&fslink->fexit.link, BPF_LINK_TYPE_TRACING,
3646 &bpf_tracing_link_lops, prog, attach_type);
3647 fslink->fexit.cookie = bpf_cookie;
3648 link = &fslink->link;
3649 } else {
3650 link = NULL;
3651 }
3652 } else {
3653 link = kzalloc_obj(*link, GFP_USER);
3654 }
3655 if (!link) {
3656 err = -ENOMEM;
3657 goto out_put_prog;
3658 }
3659 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3660 &bpf_tracing_link_lops, prog, attach_type);
3661
3662 link->link.cookie = bpf_cookie;
3663
3664 mutex_lock(&prog->aux->dst_mutex);
3665
3666 /* There are a few possible cases here:
3667 *
3668 * - if prog->aux->dst_trampoline is set, the program was just loaded
3669 * and not yet attached to anything, so we can use the values stored
3670 * in prog->aux
3671 *
3672 * - if prog->aux->dst_trampoline is NULL, the program has already been
3673 * attached to a target and its initial target was cleared (below)
3674 *
3675 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3676 * target_btf_id using the link_create API.
3677 *
3678 * - if tgt_prog == NULL when this function was called using the old
3679 * raw_tracepoint_open API, and we need a target from prog->aux
3680 *
3681 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3682 * was detached and is going for re-attachment.
3683 *
3684 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3685 * are NULL, then program was already attached and user did not provide
3686 * tgt_prog_fd so we have no way to find out or create trampoline
3687 */
3688 if (!prog->aux->dst_trampoline && !tgt_prog) {
3689 /*
3690 * Allow re-attach for TRACING and LSM programs. If it's
3691 * currently linked, bpf_trampoline_link_prog will fail.
3692 * EXT programs need to specify tgt_prog_fd, so they
3693 * re-attach in separate code path.
3694 */
3695 if (prog->type != BPF_PROG_TYPE_TRACING &&
3696 prog->type != BPF_PROG_TYPE_LSM) {
3697 err = -EINVAL;
3698 goto out_unlock;
3699 }
3700 /* We can allow re-attach only if we have valid attach_btf. */
3701 if (!prog->aux->attach_btf) {
3702 err = -EINVAL;
3703 goto out_unlock;
3704 }
3705 btf_id = prog->aux->attach_btf_id;
3706 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3707 }
3708
3709 if (!prog->aux->dst_trampoline ||
3710 (key && key != prog->aux->dst_trampoline->key)) {
3711 /* If there is no saved target, or the specified target is
3712 * different from the destination specified at load time, we
3713 * need a new trampoline and a check for compatibility
3714 */
3715 struct bpf_attach_target_info tgt_info = {};
3716
3717 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3718 &tgt_info);
3719 if (err)
3720 goto out_unlock;
3721
3722 if (tgt_info.tgt_mod) {
3723 module_put(prog->aux->mod);
3724 prog->aux->mod = tgt_info.tgt_mod;
3725 }
3726
3727 tr = bpf_trampoline_get(key, &tgt_info);
3728 if (!tr) {
3729 err = -ENOMEM;
3730 goto out_unlock;
3731 }
3732 } else {
3733 /* The caller didn't specify a target, or the target was the
3734 * same as the destination supplied during program load. This
3735 * means we can reuse the trampoline and reference from program
3736 * load time, and there is no need to allocate a new one. This
3737 * can only happen once for any program, as the saved values in
3738 * prog->aux are cleared below.
3739 */
3740 tr = prog->aux->dst_trampoline;
3741 tgt_prog = prog->aux->dst_prog;
3742 }
3743 /*
3744 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true
3745 * freplace prog. Without this check, kprobe_write_ctx=true freplace
3746 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and
3747 * then modify the registers of the kprobe prog's target kernel
3748 * function.
3749 *
3750 * This also blocks the combination of uprobe+freplace, because it is
3751 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe
3752 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by
3753 * the target perf event flags in __perf_event_set_bpf_prog().
3754 */
3755 if (prog->type == BPF_PROG_TYPE_EXT &&
3756 prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) {
3757 err = -EINVAL;
3758 goto out_unlock;
3759 }
3760
3761 err = bpf_link_prime(&link->link.link, &link_primer);
3762 if (err)
3763 goto out_unlock;
3764
3765 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3766 if (err) {
3767 bpf_link_cleanup(&link_primer);
3768 link = NULL;
3769 goto out_unlock;
3770 }
3771
3772 link->tgt_prog = tgt_prog;
3773 link->trampoline = tr;
3774
3775 /* Always clear the trampoline and target prog from prog->aux to make
3776 * sure the original attach destination is not kept alive after a
3777 * program is (re-)attached to another target.
3778 */
3779 if (prog->aux->dst_prog &&
3780 (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3781 /* got extra prog ref from syscall, or attaching to different prog */
3782 bpf_prog_put(prog->aux->dst_prog);
3783 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3784 /* we allocated a new trampoline, so free the old one */
3785 bpf_trampoline_put(prog->aux->dst_trampoline);
3786
3787 prog->aux->dst_prog = NULL;
3788 prog->aux->dst_trampoline = NULL;
3789 mutex_unlock(&prog->aux->dst_mutex);
3790
3791 return bpf_link_settle(&link_primer);
3792 out_unlock:
3793 if (tr && tr != prog->aux->dst_trampoline)
3794 bpf_trampoline_put(tr);
3795 mutex_unlock(&prog->aux->dst_mutex);
3796 kfree(link);
3797 out_put_prog:
3798 if (tgt_prog_fd && tgt_prog)
3799 bpf_prog_put(tgt_prog);
3800 return err;
3801 }
3802
bpf_raw_tp_link_release(struct bpf_link * link)3803 static void bpf_raw_tp_link_release(struct bpf_link *link)
3804 {
3805 struct bpf_raw_tp_link *raw_tp =
3806 container_of(link, struct bpf_raw_tp_link, link);
3807
3808 bpf_probe_unregister(raw_tp->btp, raw_tp);
3809 bpf_put_raw_tracepoint(raw_tp->btp);
3810 }
3811
bpf_raw_tp_link_dealloc(struct bpf_link * link)3812 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3813 {
3814 struct bpf_raw_tp_link *raw_tp =
3815 container_of(link, struct bpf_raw_tp_link, link);
3816
3817 kfree(raw_tp);
3818 }
3819
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3820 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3821 struct seq_file *seq)
3822 {
3823 struct bpf_raw_tp_link *raw_tp_link =
3824 container_of(link, struct bpf_raw_tp_link, link);
3825
3826 seq_printf(seq,
3827 "tp_name:\t%s\n"
3828 "cookie:\t%llu\n",
3829 raw_tp_link->btp->tp->name,
3830 raw_tp_link->cookie);
3831 }
3832
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3833 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3834 u32 len)
3835 {
3836 if (ulen >= len + 1) {
3837 if (copy_to_user(ubuf, buf, len + 1))
3838 return -EFAULT;
3839 } else {
3840 char zero = '\0';
3841
3842 if (copy_to_user(ubuf, buf, ulen - 1))
3843 return -EFAULT;
3844 if (put_user(zero, ubuf + ulen - 1))
3845 return -EFAULT;
3846 return -ENOSPC;
3847 }
3848
3849 return 0;
3850 }
3851
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3852 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3853 struct bpf_link_info *info)
3854 {
3855 struct bpf_raw_tp_link *raw_tp_link =
3856 container_of(link, struct bpf_raw_tp_link, link);
3857 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3858 const char *tp_name = raw_tp_link->btp->tp->name;
3859 u32 ulen = info->raw_tracepoint.tp_name_len;
3860 size_t tp_len = strlen(tp_name);
3861
3862 if (!ulen ^ !ubuf)
3863 return -EINVAL;
3864
3865 info->raw_tracepoint.tp_name_len = tp_len + 1;
3866 info->raw_tracepoint.cookie = raw_tp_link->cookie;
3867
3868 if (!ubuf)
3869 return 0;
3870
3871 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3872 }
3873
3874 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3875 .release = bpf_raw_tp_link_release,
3876 .dealloc_deferred = bpf_raw_tp_link_dealloc,
3877 .show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3878 .fill_link_info = bpf_raw_tp_link_fill_link_info,
3879 };
3880
3881 #ifdef CONFIG_PERF_EVENTS
3882 struct bpf_perf_link {
3883 struct bpf_link link;
3884 struct file *perf_file;
3885 };
3886
bpf_perf_link_release(struct bpf_link * link)3887 static void bpf_perf_link_release(struct bpf_link *link)
3888 {
3889 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3890 struct perf_event *event = perf_link->perf_file->private_data;
3891
3892 perf_event_free_bpf_prog(event);
3893 fput(perf_link->perf_file);
3894 }
3895
bpf_perf_link_dealloc(struct bpf_link * link)3896 static void bpf_perf_link_dealloc(struct bpf_link *link)
3897 {
3898 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3899
3900 kfree(perf_link);
3901 }
3902
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)3903 static int bpf_perf_link_fill_common(const struct perf_event *event,
3904 char __user *uname, u32 *ulenp,
3905 u64 *probe_offset, u64 *probe_addr,
3906 u32 *fd_type, unsigned long *missed)
3907 {
3908 const char *buf;
3909 u32 prog_id, ulen;
3910 size_t len;
3911 int err;
3912
3913 ulen = *ulenp;
3914 if (!ulen ^ !uname)
3915 return -EINVAL;
3916
3917 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3918 probe_offset, probe_addr, missed);
3919 if (err)
3920 return err;
3921
3922 if (buf) {
3923 len = strlen(buf);
3924 *ulenp = len + 1;
3925 } else {
3926 *ulenp = 1;
3927 }
3928 if (!uname)
3929 return 0;
3930
3931 if (buf) {
3932 err = bpf_copy_to_user(uname, buf, ulen, len);
3933 if (err)
3934 return err;
3935 } else {
3936 char zero = '\0';
3937
3938 if (put_user(zero, uname))
3939 return -EFAULT;
3940 }
3941 return 0;
3942 }
3943
3944 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3945 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3946 struct bpf_link_info *info)
3947 {
3948 unsigned long missed;
3949 char __user *uname;
3950 u64 addr, offset;
3951 u32 ulen, type;
3952 int err;
3953
3954 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3955 ulen = info->perf_event.kprobe.name_len;
3956 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3957 &type, &missed);
3958 if (err)
3959 return err;
3960 if (type == BPF_FD_TYPE_KRETPROBE)
3961 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3962 else
3963 info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3964 info->perf_event.kprobe.name_len = ulen;
3965 info->perf_event.kprobe.offset = offset;
3966 info->perf_event.kprobe.missed = missed;
3967 if (!kallsyms_show_value(current_cred()))
3968 addr = 0;
3969 info->perf_event.kprobe.addr = addr;
3970 info->perf_event.kprobe.cookie = event->bpf_cookie;
3971 return 0;
3972 }
3973
bpf_perf_link_fdinfo_kprobe(const struct perf_event * event,struct seq_file * seq)3974 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event,
3975 struct seq_file *seq)
3976 {
3977 const char *name;
3978 int err;
3979 u32 prog_id, type;
3980 u64 offset, addr;
3981 unsigned long missed;
3982
3983 err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
3984 &offset, &addr, &missed);
3985 if (err)
3986 return;
3987
3988 seq_printf(seq,
3989 "name:\t%s\n"
3990 "offset:\t%#llx\n"
3991 "missed:\t%lu\n"
3992 "addr:\t%#llx\n"
3993 "event_type:\t%s\n"
3994 "cookie:\t%llu\n",
3995 name, offset, missed, addr,
3996 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe",
3997 event->bpf_cookie);
3998 }
3999 #endif
4000
4001 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)4002 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
4003 struct bpf_link_info *info)
4004 {
4005 u64 ref_ctr_offset, offset;
4006 char __user *uname;
4007 u32 ulen, type;
4008 int err;
4009
4010 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
4011 ulen = info->perf_event.uprobe.name_len;
4012 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset,
4013 &type, NULL);
4014 if (err)
4015 return err;
4016
4017 if (type == BPF_FD_TYPE_URETPROBE)
4018 info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
4019 else
4020 info->perf_event.type = BPF_PERF_EVENT_UPROBE;
4021 info->perf_event.uprobe.name_len = ulen;
4022 info->perf_event.uprobe.offset = offset;
4023 info->perf_event.uprobe.cookie = event->bpf_cookie;
4024 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset;
4025 return 0;
4026 }
4027
bpf_perf_link_fdinfo_uprobe(const struct perf_event * event,struct seq_file * seq)4028 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event,
4029 struct seq_file *seq)
4030 {
4031 const char *name;
4032 int err;
4033 u32 prog_id, type;
4034 u64 offset, ref_ctr_offset;
4035 unsigned long missed;
4036
4037 err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
4038 &offset, &ref_ctr_offset, &missed);
4039 if (err)
4040 return;
4041
4042 seq_printf(seq,
4043 "name:\t%s\n"
4044 "offset:\t%#llx\n"
4045 "ref_ctr_offset:\t%#llx\n"
4046 "event_type:\t%s\n"
4047 "cookie:\t%llu\n",
4048 name, offset, ref_ctr_offset,
4049 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe",
4050 event->bpf_cookie);
4051 }
4052 #endif
4053
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)4054 static int bpf_perf_link_fill_probe(const struct perf_event *event,
4055 struct bpf_link_info *info)
4056 {
4057 #ifdef CONFIG_KPROBE_EVENTS
4058 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4059 return bpf_perf_link_fill_kprobe(event, info);
4060 #endif
4061 #ifdef CONFIG_UPROBE_EVENTS
4062 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4063 return bpf_perf_link_fill_uprobe(event, info);
4064 #endif
4065 return -EOPNOTSUPP;
4066 }
4067
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)4068 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
4069 struct bpf_link_info *info)
4070 {
4071 char __user *uname;
4072 u32 ulen;
4073 int err;
4074
4075 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
4076 ulen = info->perf_event.tracepoint.name_len;
4077 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
4078 if (err)
4079 return err;
4080
4081 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
4082 info->perf_event.tracepoint.name_len = ulen;
4083 info->perf_event.tracepoint.cookie = event->bpf_cookie;
4084 return 0;
4085 }
4086
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)4087 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
4088 struct bpf_link_info *info)
4089 {
4090 info->perf_event.event.type = event->attr.type;
4091 info->perf_event.event.config = event->attr.config;
4092 info->perf_event.event.cookie = event->bpf_cookie;
4093 info->perf_event.type = BPF_PERF_EVENT_EVENT;
4094 return 0;
4095 }
4096
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)4097 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
4098 struct bpf_link_info *info)
4099 {
4100 struct bpf_perf_link *perf_link;
4101 const struct perf_event *event;
4102
4103 perf_link = container_of(link, struct bpf_perf_link, link);
4104 event = perf_get_event(perf_link->perf_file);
4105 if (IS_ERR(event))
4106 return PTR_ERR(event);
4107
4108 switch (event->prog->type) {
4109 case BPF_PROG_TYPE_PERF_EVENT:
4110 return bpf_perf_link_fill_perf_event(event, info);
4111 case BPF_PROG_TYPE_TRACEPOINT:
4112 return bpf_perf_link_fill_tracepoint(event, info);
4113 case BPF_PROG_TYPE_KPROBE:
4114 return bpf_perf_link_fill_probe(event, info);
4115 default:
4116 return -EOPNOTSUPP;
4117 }
4118 }
4119
bpf_perf_event_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4120 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event,
4121 struct seq_file *seq)
4122 {
4123 seq_printf(seq,
4124 "type:\t%u\n"
4125 "config:\t%llu\n"
4126 "event_type:\t%s\n"
4127 "cookie:\t%llu\n",
4128 event->attr.type, event->attr.config,
4129 "event", event->bpf_cookie);
4130 }
4131
bpf_tracepoint_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4132 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event,
4133 struct seq_file *seq)
4134 {
4135 int err;
4136 const char *name;
4137 u32 prog_id;
4138
4139 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL,
4140 NULL, NULL);
4141 if (err)
4142 return;
4143
4144 seq_printf(seq,
4145 "tp_name:\t%s\n"
4146 "event_type:\t%s\n"
4147 "cookie:\t%llu\n",
4148 name, "tracepoint", event->bpf_cookie);
4149 }
4150
bpf_probe_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4151 static void bpf_probe_link_show_fdinfo(const struct perf_event *event,
4152 struct seq_file *seq)
4153 {
4154 #ifdef CONFIG_KPROBE_EVENTS
4155 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4156 return bpf_perf_link_fdinfo_kprobe(event, seq);
4157 #endif
4158
4159 #ifdef CONFIG_UPROBE_EVENTS
4160 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4161 return bpf_perf_link_fdinfo_uprobe(event, seq);
4162 #endif
4163 }
4164
bpf_perf_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)4165 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link,
4166 struct seq_file *seq)
4167 {
4168 struct bpf_perf_link *perf_link;
4169 const struct perf_event *event;
4170
4171 perf_link = container_of(link, struct bpf_perf_link, link);
4172 event = perf_get_event(perf_link->perf_file);
4173 if (IS_ERR(event))
4174 return;
4175
4176 switch (event->prog->type) {
4177 case BPF_PROG_TYPE_PERF_EVENT:
4178 return bpf_perf_event_link_show_fdinfo(event, seq);
4179 case BPF_PROG_TYPE_TRACEPOINT:
4180 return bpf_tracepoint_link_show_fdinfo(event, seq);
4181 case BPF_PROG_TYPE_KPROBE:
4182 return bpf_probe_link_show_fdinfo(event, seq);
4183 default:
4184 return;
4185 }
4186 }
4187
4188 static const struct bpf_link_ops bpf_perf_link_lops = {
4189 .release = bpf_perf_link_release,
4190 .dealloc = bpf_perf_link_dealloc,
4191 .fill_link_info = bpf_perf_link_fill_link_info,
4192 .show_fdinfo = bpf_perf_link_show_fdinfo,
4193 };
4194
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4195 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4196 {
4197 struct bpf_link_primer link_primer;
4198 struct bpf_perf_link *link;
4199 struct perf_event *event;
4200 struct file *perf_file;
4201 int err;
4202
4203 if (attr->link_create.flags)
4204 return -EINVAL;
4205
4206 perf_file = perf_event_get(attr->link_create.target_fd);
4207 if (IS_ERR(perf_file))
4208 return PTR_ERR(perf_file);
4209
4210 link = kzalloc_obj(*link, GFP_USER);
4211 if (!link) {
4212 err = -ENOMEM;
4213 goto out_put_file;
4214 }
4215 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog,
4216 attr->link_create.attach_type);
4217 link->perf_file = perf_file;
4218
4219 err = bpf_link_prime(&link->link, &link_primer);
4220 if (err) {
4221 kfree(link);
4222 goto out_put_file;
4223 }
4224
4225 event = perf_file->private_data;
4226 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
4227 if (err) {
4228 bpf_link_cleanup(&link_primer);
4229 goto out_put_file;
4230 }
4231 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
4232 bpf_prog_inc(prog);
4233
4234 return bpf_link_settle(&link_primer);
4235
4236 out_put_file:
4237 fput(perf_file);
4238 return err;
4239 }
4240 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4241 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4242 {
4243 return -EOPNOTSUPP;
4244 }
4245 #endif /* CONFIG_PERF_EVENTS */
4246
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie,enum bpf_attach_type attach_type)4247 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
4248 const char __user *user_tp_name, u64 cookie,
4249 enum bpf_attach_type attach_type)
4250 {
4251 struct bpf_link_primer link_primer;
4252 struct bpf_raw_tp_link *link;
4253 struct bpf_raw_event_map *btp;
4254 const char *tp_name;
4255 char buf[128];
4256 int err;
4257
4258 switch (prog->type) {
4259 case BPF_PROG_TYPE_TRACING:
4260 case BPF_PROG_TYPE_EXT:
4261 case BPF_PROG_TYPE_LSM:
4262 if (user_tp_name)
4263 /* The attach point for this category of programs
4264 * should be specified via btf_id during program load.
4265 */
4266 return -EINVAL;
4267 if (prog->type == BPF_PROG_TYPE_TRACING &&
4268 prog->expected_attach_type == BPF_TRACE_RAW_TP) {
4269 tp_name = prog->aux->attach_func_name;
4270 break;
4271 }
4272 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type);
4273 case BPF_PROG_TYPE_RAW_TRACEPOINT:
4274 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
4275 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
4276 return -EFAULT;
4277 buf[sizeof(buf) - 1] = 0;
4278 tp_name = buf;
4279 break;
4280 default:
4281 return -EINVAL;
4282 }
4283
4284 btp = bpf_get_raw_tracepoint(tp_name);
4285 if (!btp)
4286 return -ENOENT;
4287
4288 link = kzalloc_obj(*link, GFP_USER);
4289 if (!link) {
4290 err = -ENOMEM;
4291 goto out_put_btp;
4292 }
4293 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
4294 &bpf_raw_tp_link_lops, prog, attach_type,
4295 tracepoint_is_faultable(btp->tp));
4296 link->btp = btp;
4297 link->cookie = cookie;
4298
4299 err = bpf_link_prime(&link->link, &link_primer);
4300 if (err) {
4301 kfree(link);
4302 goto out_put_btp;
4303 }
4304
4305 err = bpf_probe_register(link->btp, link);
4306 if (err) {
4307 bpf_link_cleanup(&link_primer);
4308 goto out_put_btp;
4309 }
4310
4311 return bpf_link_settle(&link_primer);
4312
4313 out_put_btp:
4314 bpf_put_raw_tracepoint(btp);
4315 return err;
4316 }
4317
4318 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4319
bpf_raw_tracepoint_open(const union bpf_attr * attr)4320 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4321 {
4322 struct bpf_prog *prog;
4323 void __user *tp_name;
4324 __u64 cookie;
4325 int fd;
4326
4327 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4328 return -EINVAL;
4329
4330 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4331 if (IS_ERR(prog))
4332 return PTR_ERR(prog);
4333
4334 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4335 cookie = attr->raw_tracepoint.cookie;
4336 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type);
4337 if (fd < 0)
4338 bpf_prog_put(prog);
4339 return fd;
4340 }
4341
4342 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4343 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4344 {
4345 switch (attach_type) {
4346 case BPF_CGROUP_INET_INGRESS:
4347 case BPF_CGROUP_INET_EGRESS:
4348 return BPF_PROG_TYPE_CGROUP_SKB;
4349 case BPF_CGROUP_INET_SOCK_CREATE:
4350 case BPF_CGROUP_INET_SOCK_RELEASE:
4351 case BPF_CGROUP_INET4_POST_BIND:
4352 case BPF_CGROUP_INET6_POST_BIND:
4353 return BPF_PROG_TYPE_CGROUP_SOCK;
4354 case BPF_CGROUP_INET4_BIND:
4355 case BPF_CGROUP_INET6_BIND:
4356 case BPF_CGROUP_INET4_CONNECT:
4357 case BPF_CGROUP_INET6_CONNECT:
4358 case BPF_CGROUP_UNIX_CONNECT:
4359 case BPF_CGROUP_INET4_GETPEERNAME:
4360 case BPF_CGROUP_INET6_GETPEERNAME:
4361 case BPF_CGROUP_UNIX_GETPEERNAME:
4362 case BPF_CGROUP_INET4_GETSOCKNAME:
4363 case BPF_CGROUP_INET6_GETSOCKNAME:
4364 case BPF_CGROUP_UNIX_GETSOCKNAME:
4365 case BPF_CGROUP_UDP4_SENDMSG:
4366 case BPF_CGROUP_UDP6_SENDMSG:
4367 case BPF_CGROUP_UNIX_SENDMSG:
4368 case BPF_CGROUP_UDP4_RECVMSG:
4369 case BPF_CGROUP_UDP6_RECVMSG:
4370 case BPF_CGROUP_UNIX_RECVMSG:
4371 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4372 case BPF_CGROUP_SOCK_OPS:
4373 return BPF_PROG_TYPE_SOCK_OPS;
4374 case BPF_CGROUP_DEVICE:
4375 return BPF_PROG_TYPE_CGROUP_DEVICE;
4376 case BPF_SK_MSG_VERDICT:
4377 return BPF_PROG_TYPE_SK_MSG;
4378 case BPF_SK_SKB_STREAM_PARSER:
4379 case BPF_SK_SKB_STREAM_VERDICT:
4380 case BPF_SK_SKB_VERDICT:
4381 return BPF_PROG_TYPE_SK_SKB;
4382 case BPF_LIRC_MODE2:
4383 return BPF_PROG_TYPE_LIRC_MODE2;
4384 case BPF_FLOW_DISSECTOR:
4385 return BPF_PROG_TYPE_FLOW_DISSECTOR;
4386 case BPF_CGROUP_SYSCTL:
4387 return BPF_PROG_TYPE_CGROUP_SYSCTL;
4388 case BPF_CGROUP_GETSOCKOPT:
4389 case BPF_CGROUP_SETSOCKOPT:
4390 return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4391 case BPF_TRACE_ITER:
4392 case BPF_TRACE_RAW_TP:
4393 case BPF_TRACE_FENTRY:
4394 case BPF_TRACE_FEXIT:
4395 case BPF_TRACE_FSESSION:
4396 case BPF_MODIFY_RETURN:
4397 return BPF_PROG_TYPE_TRACING;
4398 case BPF_LSM_MAC:
4399 return BPF_PROG_TYPE_LSM;
4400 case BPF_SK_LOOKUP:
4401 return BPF_PROG_TYPE_SK_LOOKUP;
4402 case BPF_XDP:
4403 return BPF_PROG_TYPE_XDP;
4404 case BPF_LSM_CGROUP:
4405 return BPF_PROG_TYPE_LSM;
4406 case BPF_TCX_INGRESS:
4407 case BPF_TCX_EGRESS:
4408 case BPF_NETKIT_PRIMARY:
4409 case BPF_NETKIT_PEER:
4410 return BPF_PROG_TYPE_SCHED_CLS;
4411 default:
4412 return BPF_PROG_TYPE_UNSPEC;
4413 }
4414 }
4415
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4416 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4417 enum bpf_attach_type attach_type)
4418 {
4419 enum bpf_prog_type ptype;
4420
4421 switch (prog->type) {
4422 case BPF_PROG_TYPE_CGROUP_SOCK:
4423 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4424 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4425 case BPF_PROG_TYPE_SK_LOOKUP:
4426 return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4427 case BPF_PROG_TYPE_CGROUP_SKB:
4428 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4429 /* cg-skb progs can be loaded by unpriv user.
4430 * check permissions at attach time.
4431 */
4432 return -EPERM;
4433
4434 ptype = attach_type_to_prog_type(attach_type);
4435 if (prog->type != ptype)
4436 return -EINVAL;
4437
4438 return prog->enforce_expected_attach_type &&
4439 prog->expected_attach_type != attach_type ?
4440 -EINVAL : 0;
4441 case BPF_PROG_TYPE_EXT:
4442 return 0;
4443 case BPF_PROG_TYPE_NETFILTER:
4444 if (attach_type != BPF_NETFILTER)
4445 return -EINVAL;
4446 return 0;
4447 case BPF_PROG_TYPE_PERF_EVENT:
4448 case BPF_PROG_TYPE_TRACEPOINT:
4449 if (attach_type != BPF_PERF_EVENT)
4450 return -EINVAL;
4451 return 0;
4452 case BPF_PROG_TYPE_KPROBE:
4453 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4454 attach_type != BPF_TRACE_KPROBE_MULTI)
4455 return -EINVAL;
4456 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4457 attach_type != BPF_TRACE_KPROBE_SESSION)
4458 return -EINVAL;
4459 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4460 attach_type != BPF_TRACE_UPROBE_MULTI)
4461 return -EINVAL;
4462 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4463 attach_type != BPF_TRACE_UPROBE_SESSION)
4464 return -EINVAL;
4465 if (attach_type != BPF_PERF_EVENT &&
4466 attach_type != BPF_TRACE_KPROBE_MULTI &&
4467 attach_type != BPF_TRACE_KPROBE_SESSION &&
4468 attach_type != BPF_TRACE_UPROBE_MULTI &&
4469 attach_type != BPF_TRACE_UPROBE_SESSION)
4470 return -EINVAL;
4471 return 0;
4472 case BPF_PROG_TYPE_SCHED_CLS:
4473 if (attach_type != BPF_TCX_INGRESS &&
4474 attach_type != BPF_TCX_EGRESS &&
4475 attach_type != BPF_NETKIT_PRIMARY &&
4476 attach_type != BPF_NETKIT_PEER)
4477 return -EINVAL;
4478 return 0;
4479 default:
4480 ptype = attach_type_to_prog_type(attach_type);
4481 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4482 return -EINVAL;
4483 return 0;
4484 }
4485 }
4486
is_cgroup_prog_type(enum bpf_prog_type ptype,enum bpf_attach_type atype,bool check_atype)4487 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype,
4488 bool check_atype)
4489 {
4490 switch (ptype) {
4491 case BPF_PROG_TYPE_CGROUP_DEVICE:
4492 case BPF_PROG_TYPE_CGROUP_SKB:
4493 case BPF_PROG_TYPE_CGROUP_SOCK:
4494 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4495 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4496 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4497 case BPF_PROG_TYPE_SOCK_OPS:
4498 return true;
4499 case BPF_PROG_TYPE_LSM:
4500 return check_atype ? atype == BPF_LSM_CGROUP : true;
4501 default:
4502 return false;
4503 }
4504 }
4505
4506 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4507
4508 #define BPF_F_ATTACH_MASK_BASE \
4509 (BPF_F_ALLOW_OVERRIDE | \
4510 BPF_F_ALLOW_MULTI | \
4511 BPF_F_REPLACE | \
4512 BPF_F_PREORDER)
4513
4514 #define BPF_F_ATTACH_MASK_MPROG \
4515 (BPF_F_REPLACE | \
4516 BPF_F_BEFORE | \
4517 BPF_F_AFTER | \
4518 BPF_F_ID | \
4519 BPF_F_LINK)
4520
bpf_prog_attach(const union bpf_attr * attr)4521 static int bpf_prog_attach(const union bpf_attr *attr)
4522 {
4523 enum bpf_prog_type ptype;
4524 struct bpf_prog *prog;
4525 int ret;
4526
4527 if (CHECK_ATTR(BPF_PROG_ATTACH))
4528 return -EINVAL;
4529
4530 ptype = attach_type_to_prog_type(attr->attach_type);
4531 if (ptype == BPF_PROG_TYPE_UNSPEC)
4532 return -EINVAL;
4533 if (bpf_mprog_supported(ptype)) {
4534 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4535 return -EINVAL;
4536 } else if (is_cgroup_prog_type(ptype, 0, false)) {
4537 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG))
4538 return -EINVAL;
4539 } else {
4540 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4541 return -EINVAL;
4542 if (attr->relative_fd ||
4543 attr->expected_revision)
4544 return -EINVAL;
4545 }
4546
4547 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4548 if (IS_ERR(prog))
4549 return PTR_ERR(prog);
4550
4551 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4552 bpf_prog_put(prog);
4553 return -EINVAL;
4554 }
4555
4556 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) {
4557 ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4558 goto out;
4559 }
4560
4561 switch (ptype) {
4562 case BPF_PROG_TYPE_SK_SKB:
4563 case BPF_PROG_TYPE_SK_MSG:
4564 ret = sock_map_get_from_fd(attr, prog);
4565 break;
4566 case BPF_PROG_TYPE_LIRC_MODE2:
4567 ret = lirc_prog_attach(attr, prog);
4568 break;
4569 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4570 ret = netns_bpf_prog_attach(attr, prog);
4571 break;
4572 case BPF_PROG_TYPE_SCHED_CLS:
4573 if (attr->attach_type == BPF_TCX_INGRESS ||
4574 attr->attach_type == BPF_TCX_EGRESS)
4575 ret = tcx_prog_attach(attr, prog);
4576 else
4577 ret = netkit_prog_attach(attr, prog);
4578 break;
4579 default:
4580 ret = -EINVAL;
4581 }
4582 out:
4583 if (ret)
4584 bpf_prog_put(prog);
4585 return ret;
4586 }
4587
4588 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4589
bpf_prog_detach(const union bpf_attr * attr)4590 static int bpf_prog_detach(const union bpf_attr *attr)
4591 {
4592 struct bpf_prog *prog = NULL;
4593 enum bpf_prog_type ptype;
4594 int ret;
4595
4596 if (CHECK_ATTR(BPF_PROG_DETACH))
4597 return -EINVAL;
4598
4599 ptype = attach_type_to_prog_type(attr->attach_type);
4600 if (bpf_mprog_supported(ptype)) {
4601 if (ptype == BPF_PROG_TYPE_UNSPEC)
4602 return -EINVAL;
4603 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4604 return -EINVAL;
4605 if (attr->attach_bpf_fd) {
4606 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4607 if (IS_ERR(prog))
4608 return PTR_ERR(prog);
4609 } else if (!bpf_mprog_detach_empty(ptype)) {
4610 return -EPERM;
4611 }
4612 } else if (is_cgroup_prog_type(ptype, 0, false)) {
4613 if (attr->attach_flags || attr->relative_fd)
4614 return -EINVAL;
4615 } else if (attr->attach_flags ||
4616 attr->relative_fd ||
4617 attr->expected_revision) {
4618 return -EINVAL;
4619 }
4620
4621 switch (ptype) {
4622 case BPF_PROG_TYPE_SK_MSG:
4623 case BPF_PROG_TYPE_SK_SKB:
4624 ret = sock_map_prog_detach(attr, ptype);
4625 break;
4626 case BPF_PROG_TYPE_LIRC_MODE2:
4627 ret = lirc_prog_detach(attr);
4628 break;
4629 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4630 ret = netns_bpf_prog_detach(attr, ptype);
4631 break;
4632 case BPF_PROG_TYPE_CGROUP_DEVICE:
4633 case BPF_PROG_TYPE_CGROUP_SKB:
4634 case BPF_PROG_TYPE_CGROUP_SOCK:
4635 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4636 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4637 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4638 case BPF_PROG_TYPE_SOCK_OPS:
4639 case BPF_PROG_TYPE_LSM:
4640 ret = cgroup_bpf_prog_detach(attr, ptype);
4641 break;
4642 case BPF_PROG_TYPE_SCHED_CLS:
4643 if (attr->attach_type == BPF_TCX_INGRESS ||
4644 attr->attach_type == BPF_TCX_EGRESS)
4645 ret = tcx_prog_detach(attr, prog);
4646 else
4647 ret = netkit_prog_detach(attr, prog);
4648 break;
4649 default:
4650 ret = -EINVAL;
4651 }
4652
4653 if (prog)
4654 bpf_prog_put(prog);
4655 return ret;
4656 }
4657
4658 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4659
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4660 static int bpf_prog_query(const union bpf_attr *attr,
4661 union bpf_attr __user *uattr)
4662 {
4663 if (!bpf_net_capable())
4664 return -EPERM;
4665 if (CHECK_ATTR(BPF_PROG_QUERY))
4666 return -EINVAL;
4667 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4668 return -EINVAL;
4669
4670 switch (attr->query.attach_type) {
4671 case BPF_CGROUP_INET_INGRESS:
4672 case BPF_CGROUP_INET_EGRESS:
4673 case BPF_CGROUP_INET_SOCK_CREATE:
4674 case BPF_CGROUP_INET_SOCK_RELEASE:
4675 case BPF_CGROUP_INET4_BIND:
4676 case BPF_CGROUP_INET6_BIND:
4677 case BPF_CGROUP_INET4_POST_BIND:
4678 case BPF_CGROUP_INET6_POST_BIND:
4679 case BPF_CGROUP_INET4_CONNECT:
4680 case BPF_CGROUP_INET6_CONNECT:
4681 case BPF_CGROUP_UNIX_CONNECT:
4682 case BPF_CGROUP_INET4_GETPEERNAME:
4683 case BPF_CGROUP_INET6_GETPEERNAME:
4684 case BPF_CGROUP_UNIX_GETPEERNAME:
4685 case BPF_CGROUP_INET4_GETSOCKNAME:
4686 case BPF_CGROUP_INET6_GETSOCKNAME:
4687 case BPF_CGROUP_UNIX_GETSOCKNAME:
4688 case BPF_CGROUP_UDP4_SENDMSG:
4689 case BPF_CGROUP_UDP6_SENDMSG:
4690 case BPF_CGROUP_UNIX_SENDMSG:
4691 case BPF_CGROUP_UDP4_RECVMSG:
4692 case BPF_CGROUP_UDP6_RECVMSG:
4693 case BPF_CGROUP_UNIX_RECVMSG:
4694 case BPF_CGROUP_SOCK_OPS:
4695 case BPF_CGROUP_DEVICE:
4696 case BPF_CGROUP_SYSCTL:
4697 case BPF_CGROUP_GETSOCKOPT:
4698 case BPF_CGROUP_SETSOCKOPT:
4699 case BPF_LSM_CGROUP:
4700 return cgroup_bpf_prog_query(attr, uattr);
4701 case BPF_LIRC_MODE2:
4702 return lirc_prog_query(attr, uattr);
4703 case BPF_FLOW_DISSECTOR:
4704 case BPF_SK_LOOKUP:
4705 return netns_bpf_prog_query(attr, uattr);
4706 case BPF_SK_SKB_STREAM_PARSER:
4707 case BPF_SK_SKB_STREAM_VERDICT:
4708 case BPF_SK_MSG_VERDICT:
4709 case BPF_SK_SKB_VERDICT:
4710 return sock_map_bpf_prog_query(attr, uattr);
4711 case BPF_TCX_INGRESS:
4712 case BPF_TCX_EGRESS:
4713 return tcx_prog_query(attr, uattr);
4714 case BPF_NETKIT_PRIMARY:
4715 case BPF_NETKIT_PEER:
4716 return netkit_prog_query(attr, uattr);
4717 default:
4718 return -EINVAL;
4719 }
4720 }
4721
4722 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4723
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4724 static int bpf_prog_test_run(const union bpf_attr *attr,
4725 union bpf_attr __user *uattr)
4726 {
4727 struct bpf_prog *prog;
4728 int ret = -ENOTSUPP;
4729
4730 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4731 return -EINVAL;
4732
4733 if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4734 (!attr->test.ctx_size_in && attr->test.ctx_in))
4735 return -EINVAL;
4736
4737 if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4738 (!attr->test.ctx_size_out && attr->test.ctx_out))
4739 return -EINVAL;
4740
4741 prog = bpf_prog_get(attr->test.prog_fd);
4742 if (IS_ERR(prog))
4743 return PTR_ERR(prog);
4744
4745 if (prog->aux->ops->test_run)
4746 ret = prog->aux->ops->test_run(prog, attr, uattr);
4747
4748 bpf_prog_put(prog);
4749 return ret;
4750 }
4751
4752 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4753
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4754 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4755 union bpf_attr __user *uattr,
4756 struct idr *idr,
4757 spinlock_t *lock)
4758 {
4759 u32 next_id = attr->start_id;
4760 int err = 0;
4761
4762 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4763 return -EINVAL;
4764
4765 if (!capable(CAP_SYS_ADMIN))
4766 return -EPERM;
4767
4768 next_id++;
4769 spin_lock_bh(lock);
4770 if (!idr_get_next(idr, &next_id))
4771 err = -ENOENT;
4772 spin_unlock_bh(lock);
4773
4774 if (!err)
4775 err = put_user(next_id, &uattr->next_id);
4776
4777 return err;
4778 }
4779
bpf_map_get_curr_or_next(u32 * id)4780 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4781 {
4782 struct bpf_map *map;
4783
4784 spin_lock_bh(&map_idr_lock);
4785 again:
4786 map = idr_get_next(&map_idr, id);
4787 if (map) {
4788 map = __bpf_map_inc_not_zero(map, false);
4789 if (IS_ERR(map)) {
4790 (*id)++;
4791 goto again;
4792 }
4793 }
4794 spin_unlock_bh(&map_idr_lock);
4795
4796 return map;
4797 }
4798
bpf_prog_get_curr_or_next(u32 * id)4799 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4800 {
4801 struct bpf_prog *prog;
4802
4803 spin_lock_bh(&prog_idr_lock);
4804 again:
4805 prog = idr_get_next(&prog_idr, id);
4806 if (prog) {
4807 prog = bpf_prog_inc_not_zero(prog);
4808 if (IS_ERR(prog)) {
4809 (*id)++;
4810 goto again;
4811 }
4812 }
4813 spin_unlock_bh(&prog_idr_lock);
4814
4815 return prog;
4816 }
4817
4818 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4819
bpf_prog_by_id(u32 id)4820 struct bpf_prog *bpf_prog_by_id(u32 id)
4821 {
4822 struct bpf_prog *prog;
4823
4824 if (!id)
4825 return ERR_PTR(-ENOENT);
4826
4827 spin_lock_bh(&prog_idr_lock);
4828 prog = idr_find(&prog_idr, id);
4829 if (prog)
4830 prog = bpf_prog_inc_not_zero(prog);
4831 else
4832 prog = ERR_PTR(-ENOENT);
4833 spin_unlock_bh(&prog_idr_lock);
4834 return prog;
4835 }
4836
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4837 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4838 {
4839 struct bpf_prog *prog;
4840 u32 id = attr->prog_id;
4841 int fd;
4842
4843 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4844 return -EINVAL;
4845
4846 if (!capable(CAP_SYS_ADMIN))
4847 return -EPERM;
4848
4849 prog = bpf_prog_by_id(id);
4850 if (IS_ERR(prog))
4851 return PTR_ERR(prog);
4852
4853 fd = bpf_prog_new_fd(prog);
4854 if (fd < 0)
4855 bpf_prog_put(prog);
4856
4857 return fd;
4858 }
4859
4860 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4861
bpf_map_get_fd_by_id(const union bpf_attr * attr)4862 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4863 {
4864 struct bpf_map *map;
4865 u32 id = attr->map_id;
4866 int f_flags;
4867 int fd;
4868
4869 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4870 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4871 return -EINVAL;
4872
4873 if (!capable(CAP_SYS_ADMIN))
4874 return -EPERM;
4875
4876 f_flags = bpf_get_file_flag(attr->open_flags);
4877 if (f_flags < 0)
4878 return f_flags;
4879
4880 spin_lock_bh(&map_idr_lock);
4881 map = idr_find(&map_idr, id);
4882 if (map)
4883 map = __bpf_map_inc_not_zero(map, true);
4884 else
4885 map = ERR_PTR(-ENOENT);
4886 spin_unlock_bh(&map_idr_lock);
4887
4888 if (IS_ERR(map))
4889 return PTR_ERR(map);
4890
4891 fd = bpf_map_new_fd(map, f_flags);
4892 if (fd < 0)
4893 bpf_map_put_with_uref(map);
4894
4895 return fd;
4896 }
4897
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4898 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4899 unsigned long addr, u32 *off,
4900 u32 *type)
4901 {
4902 const struct bpf_map *map;
4903 int i;
4904
4905 mutex_lock(&prog->aux->used_maps_mutex);
4906 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4907 map = prog->aux->used_maps[i];
4908 if (map == (void *)addr) {
4909 *type = BPF_PSEUDO_MAP_FD;
4910 goto out;
4911 }
4912 if (!map->ops->map_direct_value_meta)
4913 continue;
4914 if (!map->ops->map_direct_value_meta(map, addr, off)) {
4915 *type = BPF_PSEUDO_MAP_VALUE;
4916 goto out;
4917 }
4918 }
4919 map = NULL;
4920
4921 out:
4922 mutex_unlock(&prog->aux->used_maps_mutex);
4923 return map;
4924 }
4925
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4926 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4927 const struct cred *f_cred)
4928 {
4929 const struct bpf_map *map;
4930 struct bpf_insn *insns;
4931 u32 off, type;
4932 u64 imm;
4933 u8 code;
4934 int i;
4935
4936 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4937 GFP_USER);
4938 if (!insns)
4939 return insns;
4940
4941 for (i = 0; i < prog->len; i++) {
4942 code = insns[i].code;
4943
4944 if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4945 insns[i].code = BPF_JMP | BPF_CALL;
4946 insns[i].imm = BPF_FUNC_tail_call;
4947 /* fall-through */
4948 }
4949 if (code == (BPF_JMP | BPF_CALL) ||
4950 code == (BPF_JMP | BPF_CALL_ARGS)) {
4951 if (code == (BPF_JMP | BPF_CALL_ARGS))
4952 insns[i].code = BPF_JMP | BPF_CALL;
4953 if (!bpf_dump_raw_ok(f_cred))
4954 insns[i].imm = 0;
4955 continue;
4956 }
4957 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4958 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4959 continue;
4960 }
4961
4962 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4963 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4964 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4965 continue;
4966 }
4967
4968 if (code != (BPF_LD | BPF_IMM | BPF_DW))
4969 continue;
4970
4971 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4972 map = bpf_map_from_imm(prog, imm, &off, &type);
4973 if (map) {
4974 insns[i].src_reg = type;
4975 insns[i].imm = map->id;
4976 insns[i + 1].imm = off;
4977 continue;
4978 }
4979 }
4980
4981 return insns;
4982 }
4983
set_info_rec_size(struct bpf_prog_info * info)4984 static int set_info_rec_size(struct bpf_prog_info *info)
4985 {
4986 /*
4987 * Ensure info.*_rec_size is the same as kernel expected size
4988 *
4989 * or
4990 *
4991 * Only allow zero *_rec_size if both _rec_size and _cnt are
4992 * zero. In this case, the kernel will set the expected
4993 * _rec_size back to the info.
4994 */
4995
4996 if ((info->nr_func_info || info->func_info_rec_size) &&
4997 info->func_info_rec_size != sizeof(struct bpf_func_info))
4998 return -EINVAL;
4999
5000 if ((info->nr_line_info || info->line_info_rec_size) &&
5001 info->line_info_rec_size != sizeof(struct bpf_line_info))
5002 return -EINVAL;
5003
5004 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
5005 info->jited_line_info_rec_size != sizeof(__u64))
5006 return -EINVAL;
5007
5008 info->func_info_rec_size = sizeof(struct bpf_func_info);
5009 info->line_info_rec_size = sizeof(struct bpf_line_info);
5010 info->jited_line_info_rec_size = sizeof(__u64);
5011
5012 return 0;
5013 }
5014
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)5015 static int bpf_prog_get_info_by_fd(struct file *file,
5016 struct bpf_prog *prog,
5017 const union bpf_attr *attr,
5018 union bpf_attr __user *uattr)
5019 {
5020 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5021 struct btf *attach_btf = bpf_prog_get_target_btf(prog);
5022 struct bpf_prog_info info;
5023 u32 info_len = attr->info.info_len;
5024 struct bpf_prog_kstats stats;
5025 char __user *uinsns;
5026 u32 ulen;
5027 int err;
5028
5029 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5030 if (err)
5031 return err;
5032 info_len = min_t(u32, sizeof(info), info_len);
5033
5034 memset(&info, 0, sizeof(info));
5035 if (copy_from_user(&info, uinfo, info_len))
5036 return -EFAULT;
5037
5038 info.type = prog->type;
5039 info.id = prog->aux->id;
5040 info.load_time = prog->aux->load_time;
5041 info.created_by_uid = from_kuid_munged(current_user_ns(),
5042 prog->aux->user->uid);
5043 info.gpl_compatible = prog->gpl_compatible;
5044
5045 memcpy(info.tag, prog->tag, sizeof(prog->tag));
5046 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
5047
5048 mutex_lock(&prog->aux->used_maps_mutex);
5049 ulen = info.nr_map_ids;
5050 info.nr_map_ids = prog->aux->used_map_cnt;
5051 ulen = min_t(u32, info.nr_map_ids, ulen);
5052 if (ulen) {
5053 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
5054 u32 i;
5055
5056 for (i = 0; i < ulen; i++)
5057 if (put_user(prog->aux->used_maps[i]->id,
5058 &user_map_ids[i])) {
5059 mutex_unlock(&prog->aux->used_maps_mutex);
5060 return -EFAULT;
5061 }
5062 }
5063 mutex_unlock(&prog->aux->used_maps_mutex);
5064
5065 err = set_info_rec_size(&info);
5066 if (err)
5067 return err;
5068
5069 bpf_prog_get_stats(prog, &stats);
5070 info.run_time_ns = stats.nsecs;
5071 info.run_cnt = stats.cnt;
5072 info.recursion_misses = stats.misses;
5073
5074 info.verified_insns = prog->aux->verified_insns;
5075 if (prog->aux->btf)
5076 info.btf_id = btf_obj_id(prog->aux->btf);
5077
5078 if (!bpf_capable()) {
5079 info.jited_prog_len = 0;
5080 info.xlated_prog_len = 0;
5081 info.nr_jited_ksyms = 0;
5082 info.nr_jited_func_lens = 0;
5083 info.nr_func_info = 0;
5084 info.nr_line_info = 0;
5085 info.nr_jited_line_info = 0;
5086 goto done;
5087 }
5088
5089 ulen = info.xlated_prog_len;
5090 info.xlated_prog_len = bpf_prog_insn_size(prog);
5091 if (info.xlated_prog_len && ulen) {
5092 struct bpf_insn *insns_sanitized;
5093 bool fault;
5094
5095 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) {
5096 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
5097 if (!insns_sanitized)
5098 return -ENOMEM;
5099 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
5100 ulen = min_t(u32, info.xlated_prog_len, ulen);
5101 fault = copy_to_user(uinsns, insns_sanitized, ulen);
5102 kfree(insns_sanitized);
5103 if (fault)
5104 return -EFAULT;
5105 } else {
5106 info.xlated_prog_insns = 0;
5107 }
5108 }
5109
5110 if (bpf_prog_is_offloaded(prog->aux)) {
5111 err = bpf_prog_offload_info_fill(&info, prog);
5112 if (err)
5113 return err;
5114 goto done;
5115 }
5116
5117 /* NOTE: the following code is supposed to be skipped for offload.
5118 * bpf_prog_offload_info_fill() is the place to fill similar fields
5119 * for offload.
5120 */
5121 ulen = info.jited_prog_len;
5122 if (prog->aux->func_cnt) {
5123 u32 i;
5124
5125 info.jited_prog_len = 0;
5126 for (i = 0; i < prog->aux->func_cnt; i++)
5127 info.jited_prog_len += prog->aux->func[i]->jited_len;
5128 } else {
5129 info.jited_prog_len = prog->jited_len;
5130 }
5131
5132 if (info.jited_prog_len && ulen) {
5133 if (bpf_dump_raw_ok(file->f_cred)) {
5134 uinsns = u64_to_user_ptr(info.jited_prog_insns);
5135 ulen = min_t(u32, info.jited_prog_len, ulen);
5136
5137 /* for multi-function programs, copy the JITed
5138 * instructions for all the functions
5139 */
5140 if (prog->aux->func_cnt) {
5141 u32 len, free, i;
5142 u8 *img;
5143
5144 free = ulen;
5145 for (i = 0; i < prog->aux->func_cnt; i++) {
5146 len = prog->aux->func[i]->jited_len;
5147 len = min_t(u32, len, free);
5148 img = (u8 *) prog->aux->func[i]->bpf_func;
5149 if (copy_to_user(uinsns, img, len))
5150 return -EFAULT;
5151 uinsns += len;
5152 free -= len;
5153 if (!free)
5154 break;
5155 }
5156 } else {
5157 if (copy_to_user(uinsns, prog->bpf_func, ulen))
5158 return -EFAULT;
5159 }
5160 } else {
5161 info.jited_prog_insns = 0;
5162 }
5163 }
5164
5165 ulen = info.nr_jited_ksyms;
5166 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
5167 if (ulen) {
5168 if (bpf_dump_raw_ok(file->f_cred)) {
5169 unsigned long ksym_addr;
5170 u64 __user *user_ksyms;
5171 u32 i;
5172
5173 /* copy the address of the kernel symbol
5174 * corresponding to each function
5175 */
5176 ulen = min_t(u32, info.nr_jited_ksyms, ulen);
5177 user_ksyms = u64_to_user_ptr(info.jited_ksyms);
5178 if (prog->aux->func_cnt) {
5179 for (i = 0; i < ulen; i++) {
5180 ksym_addr = (unsigned long)
5181 prog->aux->func[i]->bpf_func;
5182 if (put_user((u64) ksym_addr,
5183 &user_ksyms[i]))
5184 return -EFAULT;
5185 }
5186 } else {
5187 ksym_addr = (unsigned long) prog->bpf_func;
5188 if (put_user((u64) ksym_addr, &user_ksyms[0]))
5189 return -EFAULT;
5190 }
5191 } else {
5192 info.jited_ksyms = 0;
5193 }
5194 }
5195
5196 ulen = info.nr_jited_func_lens;
5197 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
5198 if (ulen) {
5199 if (bpf_dump_raw_ok(file->f_cred)) {
5200 u32 __user *user_lens;
5201 u32 func_len, i;
5202
5203 /* copy the JITed image lengths for each function */
5204 ulen = min_t(u32, info.nr_jited_func_lens, ulen);
5205 user_lens = u64_to_user_ptr(info.jited_func_lens);
5206 if (prog->aux->func_cnt) {
5207 for (i = 0; i < ulen; i++) {
5208 func_len =
5209 prog->aux->func[i]->jited_len;
5210 if (put_user(func_len, &user_lens[i]))
5211 return -EFAULT;
5212 }
5213 } else {
5214 func_len = prog->jited_len;
5215 if (put_user(func_len, &user_lens[0]))
5216 return -EFAULT;
5217 }
5218 } else {
5219 info.jited_func_lens = 0;
5220 }
5221 }
5222
5223 info.attach_btf_id = prog->aux->attach_btf_id;
5224 if (attach_btf)
5225 info.attach_btf_obj_id = btf_obj_id(attach_btf);
5226
5227 ulen = info.nr_func_info;
5228 info.nr_func_info = prog->aux->func_info_cnt;
5229 if (info.nr_func_info && ulen) {
5230 char __user *user_finfo;
5231
5232 user_finfo = u64_to_user_ptr(info.func_info);
5233 ulen = min_t(u32, info.nr_func_info, ulen);
5234 if (copy_to_user(user_finfo, prog->aux->func_info,
5235 info.func_info_rec_size * ulen))
5236 return -EFAULT;
5237 }
5238
5239 ulen = info.nr_line_info;
5240 info.nr_line_info = prog->aux->nr_linfo;
5241 if (info.nr_line_info && ulen) {
5242 __u8 __user *user_linfo;
5243
5244 user_linfo = u64_to_user_ptr(info.line_info);
5245 ulen = min_t(u32, info.nr_line_info, ulen);
5246 if (copy_to_user(user_linfo, prog->aux->linfo,
5247 info.line_info_rec_size * ulen))
5248 return -EFAULT;
5249 }
5250
5251 ulen = info.nr_jited_line_info;
5252 if (prog->aux->jited_linfo)
5253 info.nr_jited_line_info = prog->aux->nr_linfo;
5254 else
5255 info.nr_jited_line_info = 0;
5256 if (info.nr_jited_line_info && ulen) {
5257 if (bpf_dump_raw_ok(file->f_cred)) {
5258 unsigned long line_addr;
5259 __u64 __user *user_linfo;
5260 u32 i;
5261
5262 user_linfo = u64_to_user_ptr(info.jited_line_info);
5263 ulen = min_t(u32, info.nr_jited_line_info, ulen);
5264 for (i = 0; i < ulen; i++) {
5265 line_addr = (unsigned long)prog->aux->jited_linfo[i];
5266 if (put_user((__u64)line_addr, &user_linfo[i]))
5267 return -EFAULT;
5268 }
5269 } else {
5270 info.jited_line_info = 0;
5271 }
5272 }
5273
5274 ulen = info.nr_prog_tags;
5275 info.nr_prog_tags = prog->aux->func_cnt ? : 1;
5276 if (ulen) {
5277 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
5278 u32 i;
5279
5280 user_prog_tags = u64_to_user_ptr(info.prog_tags);
5281 ulen = min_t(u32, info.nr_prog_tags, ulen);
5282 if (prog->aux->func_cnt) {
5283 for (i = 0; i < ulen; i++) {
5284 if (copy_to_user(user_prog_tags[i],
5285 prog->aux->func[i]->tag,
5286 BPF_TAG_SIZE))
5287 return -EFAULT;
5288 }
5289 } else {
5290 if (copy_to_user(user_prog_tags[0],
5291 prog->tag, BPF_TAG_SIZE))
5292 return -EFAULT;
5293 }
5294 }
5295
5296 done:
5297 if (copy_to_user(uinfo, &info, info_len) ||
5298 put_user(info_len, &uattr->info.info_len))
5299 return -EFAULT;
5300
5301 return 0;
5302 }
5303
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)5304 static int bpf_map_get_info_by_fd(struct file *file,
5305 struct bpf_map *map,
5306 const union bpf_attr *attr,
5307 union bpf_attr __user *uattr)
5308 {
5309 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5310 struct bpf_map_info info;
5311 u32 info_len = attr->info.info_len;
5312 int err;
5313
5314 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5315 if (err)
5316 return err;
5317 info_len = min_t(u32, sizeof(info), info_len);
5318
5319 memset(&info, 0, sizeof(info));
5320 if (copy_from_user(&info, uinfo, info_len))
5321 return -EFAULT;
5322
5323 info.type = map->map_type;
5324 info.id = map->id;
5325 info.key_size = map->key_size;
5326 info.value_size = map->value_size;
5327 info.max_entries = map->max_entries;
5328 info.map_flags = map->map_flags;
5329 info.map_extra = map->map_extra;
5330 memcpy(info.name, map->name, sizeof(map->name));
5331
5332 if (map->btf) {
5333 info.btf_id = btf_obj_id(map->btf);
5334 info.btf_key_type_id = map->btf_key_type_id;
5335 info.btf_value_type_id = map->btf_value_type_id;
5336 }
5337 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5338 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5339 bpf_map_struct_ops_info_fill(&info, map);
5340
5341 if (bpf_map_is_offloaded(map)) {
5342 err = bpf_map_offload_info_fill(&info, map);
5343 if (err)
5344 return err;
5345 }
5346
5347 if (info.hash) {
5348 char __user *uhash = u64_to_user_ptr(info.hash);
5349
5350 if (!map->ops->map_get_hash)
5351 return -EINVAL;
5352
5353 if (info.hash_size != SHA256_DIGEST_SIZE)
5354 return -EINVAL;
5355
5356 if (!READ_ONCE(map->frozen))
5357 return -EPERM;
5358
5359 err = map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, map->sha);
5360 if (err != 0)
5361 return err;
5362
5363 if (copy_to_user(uhash, map->sha, SHA256_DIGEST_SIZE) != 0)
5364 return -EFAULT;
5365 } else if (info.hash_size) {
5366 return -EINVAL;
5367 }
5368
5369 if (copy_to_user(uinfo, &info, info_len) ||
5370 put_user(info_len, &uattr->info.info_len))
5371 return -EFAULT;
5372
5373 return 0;
5374 }
5375
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5376 static int bpf_btf_get_info_by_fd(struct file *file,
5377 struct btf *btf,
5378 const union bpf_attr *attr,
5379 union bpf_attr __user *uattr)
5380 {
5381 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5382 u32 info_len = attr->info.info_len;
5383 int err;
5384
5385 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5386 if (err)
5387 return err;
5388
5389 return btf_get_info_by_fd(btf, attr, uattr);
5390 }
5391
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5392 static int bpf_link_get_info_by_fd(struct file *file,
5393 struct bpf_link *link,
5394 const union bpf_attr *attr,
5395 union bpf_attr __user *uattr)
5396 {
5397 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5398 struct bpf_link_info info;
5399 u32 info_len = attr->info.info_len;
5400 int err;
5401
5402 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5403 if (err)
5404 return err;
5405 info_len = min_t(u32, sizeof(info), info_len);
5406
5407 memset(&info, 0, sizeof(info));
5408 if (copy_from_user(&info, uinfo, info_len))
5409 return -EFAULT;
5410
5411 info.type = link->type;
5412 info.id = link->id;
5413 if (link->prog)
5414 info.prog_id = link->prog->aux->id;
5415
5416 if (link->ops->fill_link_info) {
5417 err = link->ops->fill_link_info(link, &info);
5418 if (err)
5419 return err;
5420 }
5421
5422 if (copy_to_user(uinfo, &info, info_len) ||
5423 put_user(info_len, &uattr->info.info_len))
5424 return -EFAULT;
5425
5426 return 0;
5427 }
5428
5429
token_get_info_by_fd(struct file * file,struct bpf_token * token,const union bpf_attr * attr,union bpf_attr __user * uattr)5430 static int token_get_info_by_fd(struct file *file,
5431 struct bpf_token *token,
5432 const union bpf_attr *attr,
5433 union bpf_attr __user *uattr)
5434 {
5435 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5436 u32 info_len = attr->info.info_len;
5437 int err;
5438
5439 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5440 if (err)
5441 return err;
5442 return bpf_token_get_info_by_fd(token, attr, uattr);
5443 }
5444
5445 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5446
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5447 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5448 union bpf_attr __user *uattr)
5449 {
5450 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5451 return -EINVAL;
5452
5453 CLASS(fd, f)(attr->info.bpf_fd);
5454 if (fd_empty(f))
5455 return -EBADFD;
5456
5457 if (fd_file(f)->f_op == &bpf_prog_fops)
5458 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5459 uattr);
5460 else if (fd_file(f)->f_op == &bpf_map_fops)
5461 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5462 uattr);
5463 else if (fd_file(f)->f_op == &btf_fops)
5464 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5465 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5466 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5467 attr, uattr);
5468 else if (fd_file(f)->f_op == &bpf_token_fops)
5469 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5470 attr, uattr);
5471 return -EINVAL;
5472 }
5473
5474 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5475
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5476 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5477 {
5478 struct bpf_token *token = NULL;
5479
5480 if (CHECK_ATTR(BPF_BTF_LOAD))
5481 return -EINVAL;
5482
5483 if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5484 return -EINVAL;
5485
5486 if (attr->btf_flags & BPF_F_TOKEN_FD) {
5487 token = bpf_token_get_from_fd(attr->btf_token_fd);
5488 if (IS_ERR(token))
5489 return PTR_ERR(token);
5490 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5491 bpf_token_put(token);
5492 token = NULL;
5493 }
5494 }
5495
5496 if (!bpf_token_capable(token, CAP_BPF)) {
5497 bpf_token_put(token);
5498 return -EPERM;
5499 }
5500
5501 bpf_token_put(token);
5502
5503 return btf_new_fd(attr, uattr, uattr_size);
5504 }
5505
5506 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5507
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5508 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5509 {
5510 struct bpf_token *token = NULL;
5511
5512 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5513 return -EINVAL;
5514
5515 if (attr->open_flags & ~BPF_F_TOKEN_FD)
5516 return -EINVAL;
5517
5518 if (attr->open_flags & BPF_F_TOKEN_FD) {
5519 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5520 if (IS_ERR(token))
5521 return PTR_ERR(token);
5522 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5523 bpf_token_put(token);
5524 token = NULL;
5525 }
5526 }
5527
5528 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5529 bpf_token_put(token);
5530 return -EPERM;
5531 }
5532
5533 bpf_token_put(token);
5534
5535 return btf_get_fd_by_id(attr->btf_id);
5536 }
5537
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)5538 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5539 union bpf_attr __user *uattr,
5540 u32 prog_id, u32 fd_type,
5541 const char *buf, u64 probe_offset,
5542 u64 probe_addr)
5543 {
5544 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5545 u32 len = buf ? strlen(buf) : 0, input_len;
5546 int err = 0;
5547
5548 if (put_user(len, &uattr->task_fd_query.buf_len))
5549 return -EFAULT;
5550 input_len = attr->task_fd_query.buf_len;
5551 if (input_len && ubuf) {
5552 if (!len) {
5553 /* nothing to copy, just make ubuf NULL terminated */
5554 char zero = '\0';
5555
5556 if (put_user(zero, ubuf))
5557 return -EFAULT;
5558 } else {
5559 err = bpf_copy_to_user(ubuf, buf, input_len, len);
5560 if (err == -EFAULT)
5561 return err;
5562 }
5563 }
5564
5565 if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5566 put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5567 put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5568 put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5569 return -EFAULT;
5570
5571 return err;
5572 }
5573
5574 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5575
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5576 static int bpf_task_fd_query(const union bpf_attr *attr,
5577 union bpf_attr __user *uattr)
5578 {
5579 pid_t pid = attr->task_fd_query.pid;
5580 u32 fd = attr->task_fd_query.fd;
5581 const struct perf_event *event;
5582 struct task_struct *task;
5583 struct file *file;
5584 int err;
5585
5586 if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5587 return -EINVAL;
5588
5589 if (!capable(CAP_SYS_ADMIN))
5590 return -EPERM;
5591
5592 if (attr->task_fd_query.flags != 0)
5593 return -EINVAL;
5594
5595 rcu_read_lock();
5596 task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5597 rcu_read_unlock();
5598 if (!task)
5599 return -ENOENT;
5600
5601 err = 0;
5602 file = fget_task(task, fd);
5603 put_task_struct(task);
5604 if (!file)
5605 return -EBADF;
5606
5607 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5608 struct bpf_link *link = file->private_data;
5609
5610 if (link->ops == &bpf_raw_tp_link_lops) {
5611 struct bpf_raw_tp_link *raw_tp =
5612 container_of(link, struct bpf_raw_tp_link, link);
5613 struct bpf_raw_event_map *btp = raw_tp->btp;
5614
5615 err = bpf_task_fd_query_copy(attr, uattr,
5616 raw_tp->link.prog->aux->id,
5617 BPF_FD_TYPE_RAW_TRACEPOINT,
5618 btp->tp->name, 0, 0);
5619 goto put_file;
5620 }
5621 goto out_not_supp;
5622 }
5623
5624 event = perf_get_event(file);
5625 if (!IS_ERR(event)) {
5626 u64 probe_offset, probe_addr;
5627 u32 prog_id, fd_type;
5628 const char *buf;
5629
5630 err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5631 &buf, &probe_offset,
5632 &probe_addr, NULL);
5633 if (!err)
5634 err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5635 fd_type, buf,
5636 probe_offset,
5637 probe_addr);
5638 goto put_file;
5639 }
5640
5641 out_not_supp:
5642 err = -ENOTSUPP;
5643 put_file:
5644 fput(file);
5645 return err;
5646 }
5647
5648 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5649
5650 #define BPF_DO_BATCH(fn, ...) \
5651 do { \
5652 if (!fn) { \
5653 err = -ENOTSUPP; \
5654 goto err_put; \
5655 } \
5656 err = fn(__VA_ARGS__); \
5657 } while (0)
5658
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5659 static int bpf_map_do_batch(const union bpf_attr *attr,
5660 union bpf_attr __user *uattr,
5661 int cmd)
5662 {
5663 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH ||
5664 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5665 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5666 struct bpf_map *map;
5667 int err;
5668
5669 if (CHECK_ATTR(BPF_MAP_BATCH))
5670 return -EINVAL;
5671
5672 CLASS(fd, f)(attr->batch.map_fd);
5673
5674 map = __bpf_map_get(f);
5675 if (IS_ERR(map))
5676 return PTR_ERR(map);
5677 if (has_write)
5678 bpf_map_write_active_inc(map);
5679 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5680 err = -EPERM;
5681 goto err_put;
5682 }
5683 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5684 err = -EPERM;
5685 goto err_put;
5686 }
5687
5688 if (cmd == BPF_MAP_LOOKUP_BATCH)
5689 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5690 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5691 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5692 else if (cmd == BPF_MAP_UPDATE_BATCH)
5693 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5694 else
5695 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5696 err_put:
5697 if (has_write) {
5698 maybe_wait_bpf_programs(map);
5699 bpf_map_write_active_dec(map);
5700 }
5701 return err;
5702 }
5703
5704 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5705 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5706 {
5707 struct bpf_prog *prog;
5708 int ret;
5709
5710 if (CHECK_ATTR(BPF_LINK_CREATE))
5711 return -EINVAL;
5712
5713 if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5714 return bpf_struct_ops_link_create(attr);
5715
5716 prog = bpf_prog_get(attr->link_create.prog_fd);
5717 if (IS_ERR(prog))
5718 return PTR_ERR(prog);
5719
5720 ret = bpf_prog_attach_check_attach_type(prog,
5721 attr->link_create.attach_type);
5722 if (ret)
5723 goto out;
5724
5725 switch (prog->type) {
5726 case BPF_PROG_TYPE_CGROUP_SKB:
5727 case BPF_PROG_TYPE_CGROUP_SOCK:
5728 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5729 case BPF_PROG_TYPE_SOCK_OPS:
5730 case BPF_PROG_TYPE_CGROUP_DEVICE:
5731 case BPF_PROG_TYPE_CGROUP_SYSCTL:
5732 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5733 ret = cgroup_bpf_link_attach(attr, prog);
5734 break;
5735 case BPF_PROG_TYPE_EXT:
5736 ret = bpf_tracing_prog_attach(prog,
5737 attr->link_create.target_fd,
5738 attr->link_create.target_btf_id,
5739 attr->link_create.tracing.cookie,
5740 attr->link_create.attach_type);
5741 break;
5742 case BPF_PROG_TYPE_LSM:
5743 case BPF_PROG_TYPE_TRACING:
5744 if (attr->link_create.attach_type != prog->expected_attach_type) {
5745 ret = -EINVAL;
5746 goto out;
5747 }
5748 if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5749 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie,
5750 attr->link_create.attach_type);
5751 else if (prog->expected_attach_type == BPF_TRACE_ITER)
5752 ret = bpf_iter_link_attach(attr, uattr, prog);
5753 else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5754 ret = cgroup_bpf_link_attach(attr, prog);
5755 else
5756 ret = bpf_tracing_prog_attach(prog,
5757 attr->link_create.target_fd,
5758 attr->link_create.target_btf_id,
5759 attr->link_create.tracing.cookie,
5760 attr->link_create.attach_type);
5761 break;
5762 case BPF_PROG_TYPE_FLOW_DISSECTOR:
5763 case BPF_PROG_TYPE_SK_LOOKUP:
5764 ret = netns_bpf_link_create(attr, prog);
5765 break;
5766 case BPF_PROG_TYPE_SK_MSG:
5767 case BPF_PROG_TYPE_SK_SKB:
5768 ret = sock_map_link_create(attr, prog);
5769 break;
5770 #ifdef CONFIG_NET
5771 case BPF_PROG_TYPE_XDP:
5772 ret = bpf_xdp_link_attach(attr, prog);
5773 break;
5774 case BPF_PROG_TYPE_SCHED_CLS:
5775 if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5776 attr->link_create.attach_type == BPF_TCX_EGRESS)
5777 ret = tcx_link_attach(attr, prog);
5778 else
5779 ret = netkit_link_attach(attr, prog);
5780 break;
5781 case BPF_PROG_TYPE_NETFILTER:
5782 ret = bpf_nf_link_attach(attr, prog);
5783 break;
5784 #endif
5785 case BPF_PROG_TYPE_PERF_EVENT:
5786 case BPF_PROG_TYPE_TRACEPOINT:
5787 ret = bpf_perf_link_attach(attr, prog);
5788 break;
5789 case BPF_PROG_TYPE_KPROBE:
5790 if (attr->link_create.attach_type == BPF_PERF_EVENT)
5791 ret = bpf_perf_link_attach(attr, prog);
5792 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5793 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5794 ret = bpf_kprobe_multi_link_attach(attr, prog);
5795 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5796 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5797 ret = bpf_uprobe_multi_link_attach(attr, prog);
5798 break;
5799 default:
5800 ret = -EINVAL;
5801 }
5802
5803 out:
5804 if (ret < 0)
5805 bpf_prog_put(prog);
5806 return ret;
5807 }
5808
link_update_map(struct bpf_link * link,union bpf_attr * attr)5809 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5810 {
5811 struct bpf_map *new_map, *old_map = NULL;
5812 int ret;
5813
5814 new_map = bpf_map_get(attr->link_update.new_map_fd);
5815 if (IS_ERR(new_map))
5816 return PTR_ERR(new_map);
5817
5818 if (attr->link_update.flags & BPF_F_REPLACE) {
5819 old_map = bpf_map_get(attr->link_update.old_map_fd);
5820 if (IS_ERR(old_map)) {
5821 ret = PTR_ERR(old_map);
5822 goto out_put;
5823 }
5824 } else if (attr->link_update.old_map_fd) {
5825 ret = -EINVAL;
5826 goto out_put;
5827 }
5828
5829 ret = link->ops->update_map(link, new_map, old_map);
5830
5831 if (old_map)
5832 bpf_map_put(old_map);
5833 out_put:
5834 bpf_map_put(new_map);
5835 return ret;
5836 }
5837
5838 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5839
link_update(union bpf_attr * attr)5840 static int link_update(union bpf_attr *attr)
5841 {
5842 struct bpf_prog *old_prog = NULL, *new_prog;
5843 struct bpf_link *link;
5844 u32 flags;
5845 int ret;
5846
5847 if (CHECK_ATTR(BPF_LINK_UPDATE))
5848 return -EINVAL;
5849
5850 flags = attr->link_update.flags;
5851 if (flags & ~BPF_F_REPLACE)
5852 return -EINVAL;
5853
5854 link = bpf_link_get_from_fd(attr->link_update.link_fd);
5855 if (IS_ERR(link))
5856 return PTR_ERR(link);
5857
5858 if (link->ops->update_map) {
5859 ret = link_update_map(link, attr);
5860 goto out_put_link;
5861 }
5862
5863 new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5864 if (IS_ERR(new_prog)) {
5865 ret = PTR_ERR(new_prog);
5866 goto out_put_link;
5867 }
5868
5869 if (flags & BPF_F_REPLACE) {
5870 old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5871 if (IS_ERR(old_prog)) {
5872 ret = PTR_ERR(old_prog);
5873 old_prog = NULL;
5874 goto out_put_progs;
5875 }
5876 } else if (attr->link_update.old_prog_fd) {
5877 ret = -EINVAL;
5878 goto out_put_progs;
5879 }
5880
5881 if (link->ops->update_prog)
5882 ret = link->ops->update_prog(link, new_prog, old_prog);
5883 else
5884 ret = -EINVAL;
5885
5886 out_put_progs:
5887 if (old_prog)
5888 bpf_prog_put(old_prog);
5889 if (ret)
5890 bpf_prog_put(new_prog);
5891 out_put_link:
5892 bpf_link_put_direct(link);
5893 return ret;
5894 }
5895
5896 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5897
link_detach(union bpf_attr * attr)5898 static int link_detach(union bpf_attr *attr)
5899 {
5900 struct bpf_link *link;
5901 int ret;
5902
5903 if (CHECK_ATTR(BPF_LINK_DETACH))
5904 return -EINVAL;
5905
5906 link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5907 if (IS_ERR(link))
5908 return PTR_ERR(link);
5909
5910 if (link->ops->detach)
5911 ret = link->ops->detach(link);
5912 else
5913 ret = -EOPNOTSUPP;
5914
5915 bpf_link_put_direct(link);
5916 return ret;
5917 }
5918
bpf_link_inc_not_zero(struct bpf_link * link)5919 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5920 {
5921 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5922 }
5923 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5924
bpf_link_by_id(u32 id)5925 struct bpf_link *bpf_link_by_id(u32 id)
5926 {
5927 struct bpf_link *link;
5928
5929 if (!id)
5930 return ERR_PTR(-ENOENT);
5931
5932 spin_lock_bh(&link_idr_lock);
5933 /* before link is "settled", ID is 0, pretend it doesn't exist yet */
5934 link = idr_find(&link_idr, id);
5935 if (link) {
5936 if (link->id)
5937 link = bpf_link_inc_not_zero(link);
5938 else
5939 link = ERR_PTR(-EAGAIN);
5940 } else {
5941 link = ERR_PTR(-ENOENT);
5942 }
5943 spin_unlock_bh(&link_idr_lock);
5944 return link;
5945 }
5946
bpf_link_get_curr_or_next(u32 * id)5947 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5948 {
5949 struct bpf_link *link;
5950
5951 spin_lock_bh(&link_idr_lock);
5952 again:
5953 link = idr_get_next(&link_idr, id);
5954 if (link) {
5955 link = bpf_link_inc_not_zero(link);
5956 if (IS_ERR(link)) {
5957 (*id)++;
5958 goto again;
5959 }
5960 }
5961 spin_unlock_bh(&link_idr_lock);
5962
5963 return link;
5964 }
5965
5966 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5967
bpf_link_get_fd_by_id(const union bpf_attr * attr)5968 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5969 {
5970 struct bpf_link *link;
5971 u32 id = attr->link_id;
5972 int fd;
5973
5974 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5975 return -EINVAL;
5976
5977 if (!capable(CAP_SYS_ADMIN))
5978 return -EPERM;
5979
5980 link = bpf_link_by_id(id);
5981 if (IS_ERR(link))
5982 return PTR_ERR(link);
5983
5984 fd = bpf_link_new_fd(link);
5985 if (fd < 0)
5986 bpf_link_put_direct(link);
5987
5988 return fd;
5989 }
5990
5991 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5992
bpf_stats_release(struct inode * inode,struct file * file)5993 static int bpf_stats_release(struct inode *inode, struct file *file)
5994 {
5995 mutex_lock(&bpf_stats_enabled_mutex);
5996 static_key_slow_dec(&bpf_stats_enabled_key.key);
5997 mutex_unlock(&bpf_stats_enabled_mutex);
5998 return 0;
5999 }
6000
6001 static const struct file_operations bpf_stats_fops = {
6002 .release = bpf_stats_release,
6003 };
6004
bpf_enable_runtime_stats(void)6005 static int bpf_enable_runtime_stats(void)
6006 {
6007 int fd;
6008
6009 mutex_lock(&bpf_stats_enabled_mutex);
6010
6011 /* Set a very high limit to avoid overflow */
6012 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
6013 mutex_unlock(&bpf_stats_enabled_mutex);
6014 return -EBUSY;
6015 }
6016
6017 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
6018 if (fd >= 0)
6019 static_key_slow_inc(&bpf_stats_enabled_key.key);
6020
6021 mutex_unlock(&bpf_stats_enabled_mutex);
6022 return fd;
6023 }
6024
6025 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
6026
bpf_enable_stats(union bpf_attr * attr)6027 static int bpf_enable_stats(union bpf_attr *attr)
6028 {
6029
6030 if (CHECK_ATTR(BPF_ENABLE_STATS))
6031 return -EINVAL;
6032
6033 if (!capable(CAP_SYS_ADMIN))
6034 return -EPERM;
6035
6036 switch (attr->enable_stats.type) {
6037 case BPF_STATS_RUN_TIME:
6038 return bpf_enable_runtime_stats();
6039 default:
6040 break;
6041 }
6042 return -EINVAL;
6043 }
6044
6045 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
6046
bpf_iter_create(union bpf_attr * attr)6047 static int bpf_iter_create(union bpf_attr *attr)
6048 {
6049 struct bpf_link *link;
6050 int err;
6051
6052 if (CHECK_ATTR(BPF_ITER_CREATE))
6053 return -EINVAL;
6054
6055 if (attr->iter_create.flags)
6056 return -EINVAL;
6057
6058 link = bpf_link_get_from_fd(attr->iter_create.link_fd);
6059 if (IS_ERR(link))
6060 return PTR_ERR(link);
6061
6062 err = bpf_iter_new_fd(link);
6063 bpf_link_put_direct(link);
6064
6065 return err;
6066 }
6067
6068 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
6069
bpf_prog_bind_map(union bpf_attr * attr)6070 static int bpf_prog_bind_map(union bpf_attr *attr)
6071 {
6072 struct bpf_prog *prog;
6073 struct bpf_map *map;
6074 struct bpf_map **used_maps_old, **used_maps_new;
6075 int i, ret = 0;
6076
6077 if (CHECK_ATTR(BPF_PROG_BIND_MAP))
6078 return -EINVAL;
6079
6080 if (attr->prog_bind_map.flags)
6081 return -EINVAL;
6082
6083 prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
6084 if (IS_ERR(prog))
6085 return PTR_ERR(prog);
6086
6087 map = bpf_map_get(attr->prog_bind_map.map_fd);
6088 if (IS_ERR(map)) {
6089 ret = PTR_ERR(map);
6090 goto out_prog_put;
6091 }
6092
6093 mutex_lock(&prog->aux->used_maps_mutex);
6094
6095 used_maps_old = prog->aux->used_maps;
6096
6097 for (i = 0; i < prog->aux->used_map_cnt; i++)
6098 if (used_maps_old[i] == map) {
6099 bpf_map_put(map);
6100 goto out_unlock;
6101 }
6102
6103 used_maps_new = kmalloc_objs(used_maps_new[0],
6104 prog->aux->used_map_cnt + 1);
6105 if (!used_maps_new) {
6106 ret = -ENOMEM;
6107 goto out_unlock;
6108 }
6109
6110 /* The bpf program will not access the bpf map, but for the sake of
6111 * simplicity, increase sleepable_refcnt for sleepable program as well.
6112 */
6113 if (prog->sleepable)
6114 atomic64_inc(&map->sleepable_refcnt);
6115 memcpy(used_maps_new, used_maps_old,
6116 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
6117 used_maps_new[prog->aux->used_map_cnt] = map;
6118
6119 prog->aux->used_map_cnt++;
6120 prog->aux->used_maps = used_maps_new;
6121
6122 kfree(used_maps_old);
6123
6124 out_unlock:
6125 mutex_unlock(&prog->aux->used_maps_mutex);
6126
6127 if (ret)
6128 bpf_map_put(map);
6129 out_prog_put:
6130 bpf_prog_put(prog);
6131 return ret;
6132 }
6133
6134 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
6135
token_create(union bpf_attr * attr)6136 static int token_create(union bpf_attr *attr)
6137 {
6138 if (CHECK_ATTR(BPF_TOKEN_CREATE))
6139 return -EINVAL;
6140
6141 /* no flags are supported yet */
6142 if (attr->token_create.flags)
6143 return -EINVAL;
6144
6145 return bpf_token_create(attr);
6146 }
6147
6148 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd
6149
prog_stream_read(union bpf_attr * attr)6150 static int prog_stream_read(union bpf_attr *attr)
6151 {
6152 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf);
6153 u32 len = attr->prog_stream_read.stream_buf_len;
6154 struct bpf_prog *prog;
6155 int ret;
6156
6157 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD))
6158 return -EINVAL;
6159
6160 prog = bpf_prog_get(attr->prog_stream_read.prog_fd);
6161 if (IS_ERR(prog))
6162 return PTR_ERR(prog);
6163
6164 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len);
6165 bpf_prog_put(prog);
6166
6167 return ret;
6168 }
6169
6170 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.prog_fd
6171
prog_assoc_struct_ops(union bpf_attr * attr)6172 static int prog_assoc_struct_ops(union bpf_attr *attr)
6173 {
6174 struct bpf_prog *prog;
6175 struct bpf_map *map;
6176 int ret;
6177
6178 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS))
6179 return -EINVAL;
6180
6181 if (attr->prog_assoc_struct_ops.flags)
6182 return -EINVAL;
6183
6184 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd);
6185 if (IS_ERR(prog))
6186 return PTR_ERR(prog);
6187
6188 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) {
6189 ret = -EINVAL;
6190 goto put_prog;
6191 }
6192
6193 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd);
6194 if (IS_ERR(map)) {
6195 ret = PTR_ERR(map);
6196 goto put_prog;
6197 }
6198
6199 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) {
6200 ret = -EINVAL;
6201 goto put_map;
6202 }
6203
6204 ret = bpf_prog_assoc_struct_ops(prog, map);
6205
6206 put_map:
6207 bpf_map_put(map);
6208 put_prog:
6209 bpf_prog_put(prog);
6210 return ret;
6211 }
6212
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)6213 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
6214 {
6215 union bpf_attr attr;
6216 int err;
6217
6218 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
6219 if (err)
6220 return err;
6221 size = min_t(u32, size, sizeof(attr));
6222
6223 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
6224 memset(&attr, 0, sizeof(attr));
6225 if (copy_from_bpfptr(&attr, uattr, size) != 0)
6226 return -EFAULT;
6227
6228 err = security_bpf(cmd, &attr, size, uattr.is_kernel);
6229 if (err < 0)
6230 return err;
6231
6232 switch (cmd) {
6233 case BPF_MAP_CREATE:
6234 err = map_create(&attr, uattr);
6235 break;
6236 case BPF_MAP_LOOKUP_ELEM:
6237 err = map_lookup_elem(&attr);
6238 break;
6239 case BPF_MAP_UPDATE_ELEM:
6240 err = map_update_elem(&attr, uattr);
6241 break;
6242 case BPF_MAP_DELETE_ELEM:
6243 err = map_delete_elem(&attr, uattr);
6244 break;
6245 case BPF_MAP_GET_NEXT_KEY:
6246 err = map_get_next_key(&attr);
6247 break;
6248 case BPF_MAP_FREEZE:
6249 err = map_freeze(&attr);
6250 break;
6251 case BPF_PROG_LOAD:
6252 err = bpf_prog_load(&attr, uattr, size);
6253 break;
6254 case BPF_OBJ_PIN:
6255 err = bpf_obj_pin(&attr);
6256 break;
6257 case BPF_OBJ_GET:
6258 err = bpf_obj_get(&attr);
6259 break;
6260 case BPF_PROG_ATTACH:
6261 err = bpf_prog_attach(&attr);
6262 break;
6263 case BPF_PROG_DETACH:
6264 err = bpf_prog_detach(&attr);
6265 break;
6266 case BPF_PROG_QUERY:
6267 err = bpf_prog_query(&attr, uattr.user);
6268 break;
6269 case BPF_PROG_TEST_RUN:
6270 err = bpf_prog_test_run(&attr, uattr.user);
6271 break;
6272 case BPF_PROG_GET_NEXT_ID:
6273 err = bpf_obj_get_next_id(&attr, uattr.user,
6274 &prog_idr, &prog_idr_lock);
6275 break;
6276 case BPF_MAP_GET_NEXT_ID:
6277 err = bpf_obj_get_next_id(&attr, uattr.user,
6278 &map_idr, &map_idr_lock);
6279 break;
6280 case BPF_BTF_GET_NEXT_ID:
6281 err = bpf_obj_get_next_id(&attr, uattr.user,
6282 &btf_idr, &btf_idr_lock);
6283 break;
6284 case BPF_PROG_GET_FD_BY_ID:
6285 err = bpf_prog_get_fd_by_id(&attr);
6286 break;
6287 case BPF_MAP_GET_FD_BY_ID:
6288 err = bpf_map_get_fd_by_id(&attr);
6289 break;
6290 case BPF_OBJ_GET_INFO_BY_FD:
6291 err = bpf_obj_get_info_by_fd(&attr, uattr.user);
6292 break;
6293 case BPF_RAW_TRACEPOINT_OPEN:
6294 err = bpf_raw_tracepoint_open(&attr);
6295 break;
6296 case BPF_BTF_LOAD:
6297 err = bpf_btf_load(&attr, uattr, size);
6298 break;
6299 case BPF_BTF_GET_FD_BY_ID:
6300 err = bpf_btf_get_fd_by_id(&attr);
6301 break;
6302 case BPF_TASK_FD_QUERY:
6303 err = bpf_task_fd_query(&attr, uattr.user);
6304 break;
6305 case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
6306 err = map_lookup_and_delete_elem(&attr);
6307 break;
6308 case BPF_MAP_LOOKUP_BATCH:
6309 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
6310 break;
6311 case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
6312 err = bpf_map_do_batch(&attr, uattr.user,
6313 BPF_MAP_LOOKUP_AND_DELETE_BATCH);
6314 break;
6315 case BPF_MAP_UPDATE_BATCH:
6316 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
6317 break;
6318 case BPF_MAP_DELETE_BATCH:
6319 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
6320 break;
6321 case BPF_LINK_CREATE:
6322 err = link_create(&attr, uattr);
6323 break;
6324 case BPF_LINK_UPDATE:
6325 err = link_update(&attr);
6326 break;
6327 case BPF_LINK_GET_FD_BY_ID:
6328 err = bpf_link_get_fd_by_id(&attr);
6329 break;
6330 case BPF_LINK_GET_NEXT_ID:
6331 err = bpf_obj_get_next_id(&attr, uattr.user,
6332 &link_idr, &link_idr_lock);
6333 break;
6334 case BPF_ENABLE_STATS:
6335 err = bpf_enable_stats(&attr);
6336 break;
6337 case BPF_ITER_CREATE:
6338 err = bpf_iter_create(&attr);
6339 break;
6340 case BPF_LINK_DETACH:
6341 err = link_detach(&attr);
6342 break;
6343 case BPF_PROG_BIND_MAP:
6344 err = bpf_prog_bind_map(&attr);
6345 break;
6346 case BPF_TOKEN_CREATE:
6347 err = token_create(&attr);
6348 break;
6349 case BPF_PROG_STREAM_READ_BY_FD:
6350 err = prog_stream_read(&attr);
6351 break;
6352 case BPF_PROG_ASSOC_STRUCT_OPS:
6353 err = prog_assoc_struct_ops(&attr);
6354 break;
6355 default:
6356 err = -EINVAL;
6357 break;
6358 }
6359
6360 return err;
6361 }
6362
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)6363 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
6364 {
6365 return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
6366 }
6367
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)6368 static bool syscall_prog_is_valid_access(int off, int size,
6369 enum bpf_access_type type,
6370 const struct bpf_prog *prog,
6371 struct bpf_insn_access_aux *info)
6372 {
6373 if (off < 0 || off >= U16_MAX)
6374 return false;
6375 /* No alignment requirements for syscall ctx accesses. */
6376 return true;
6377 }
6378
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)6379 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
6380 {
6381 switch (cmd) {
6382 case BPF_MAP_CREATE:
6383 case BPF_MAP_DELETE_ELEM:
6384 case BPF_MAP_UPDATE_ELEM:
6385 case BPF_MAP_FREEZE:
6386 case BPF_MAP_GET_FD_BY_ID:
6387 case BPF_PROG_LOAD:
6388 case BPF_BTF_LOAD:
6389 case BPF_LINK_CREATE:
6390 case BPF_RAW_TRACEPOINT_OPEN:
6391 break;
6392 default:
6393 return -EINVAL;
6394 }
6395 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
6396 }
6397
6398
6399 /* To shut up -Wmissing-prototypes.
6400 * This function is used by the kernel light skeleton
6401 * to load bpf programs when modules are loaded or during kernel boot.
6402 * See tools/lib/bpf/skel_internal.h
6403 */
6404 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
6405
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)6406 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
6407 {
6408 struct bpf_prog * __maybe_unused prog;
6409 struct bpf_tramp_run_ctx __maybe_unused run_ctx;
6410
6411 switch (cmd) {
6412 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
6413 case BPF_PROG_TEST_RUN:
6414 if (attr->test.data_in || attr->test.data_out ||
6415 attr->test.ctx_out || attr->test.duration ||
6416 attr->test.repeat || attr->test.flags)
6417 return -EINVAL;
6418
6419 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
6420 if (IS_ERR(prog))
6421 return PTR_ERR(prog);
6422
6423 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6424 attr->test.ctx_size_in > U16_MAX) {
6425 bpf_prog_put(prog);
6426 return -EINVAL;
6427 }
6428
6429 run_ctx.bpf_cookie = 0;
6430 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6431 /* recursion detected */
6432 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6433 bpf_prog_put(prog);
6434 return -EBUSY;
6435 }
6436 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6437 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6438 &run_ctx);
6439 bpf_prog_put(prog);
6440 return 0;
6441 #endif
6442 default:
6443 return ____bpf_sys_bpf(cmd, attr, size);
6444 }
6445 }
6446 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL");
6447
6448 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6449 .func = bpf_sys_bpf,
6450 .gpl_only = false,
6451 .ret_type = RET_INTEGER,
6452 .arg1_type = ARG_ANYTHING,
6453 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
6454 .arg3_type = ARG_CONST_SIZE,
6455 };
6456
6457 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6458 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6459 {
6460 return bpf_base_func_proto(func_id, prog);
6461 }
6462
BPF_CALL_1(bpf_sys_close,u32,fd)6463 BPF_CALL_1(bpf_sys_close, u32, fd)
6464 {
6465 /* When bpf program calls this helper there should not be
6466 * an fdget() without matching completed fdput().
6467 * This helper is allowed in the following callchain only:
6468 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6469 */
6470 return close_fd(fd);
6471 }
6472
6473 static const struct bpf_func_proto bpf_sys_close_proto = {
6474 .func = bpf_sys_close,
6475 .gpl_only = false,
6476 .ret_type = RET_INTEGER,
6477 .arg1_type = ARG_ANYTHING,
6478 };
6479
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6480 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6481 {
6482 *res = 0;
6483 if (flags)
6484 return -EINVAL;
6485
6486 if (name_sz <= 1 || name[name_sz - 1])
6487 return -EINVAL;
6488
6489 if (!bpf_dump_raw_ok(current_cred()))
6490 return -EPERM;
6491
6492 *res = kallsyms_lookup_name(name);
6493 return *res ? 0 : -ENOENT;
6494 }
6495
6496 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6497 .func = bpf_kallsyms_lookup_name,
6498 .gpl_only = false,
6499 .ret_type = RET_INTEGER,
6500 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
6501 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
6502 .arg3_type = ARG_ANYTHING,
6503 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6504 .arg4_size = sizeof(u64),
6505 };
6506
6507 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6508 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6509 {
6510 switch (func_id) {
6511 case BPF_FUNC_sys_bpf:
6512 return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6513 ? NULL : &bpf_sys_bpf_proto;
6514 case BPF_FUNC_btf_find_by_name_kind:
6515 return &bpf_btf_find_by_name_kind_proto;
6516 case BPF_FUNC_sys_close:
6517 return &bpf_sys_close_proto;
6518 case BPF_FUNC_kallsyms_lookup_name:
6519 return &bpf_kallsyms_lookup_name_proto;
6520 default:
6521 return tracing_prog_func_proto(func_id, prog);
6522 }
6523 }
6524
6525 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6526 .get_func_proto = syscall_prog_func_proto,
6527 .is_valid_access = syscall_prog_is_valid_access,
6528 };
6529
6530 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6531 .test_run = bpf_prog_test_run_syscall,
6532 };
6533
6534 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6535 static int bpf_stats_handler(const struct ctl_table *table, int write,
6536 void *buffer, size_t *lenp, loff_t *ppos)
6537 {
6538 struct static_key *key = (struct static_key *)table->data;
6539 static int saved_val;
6540 int val, ret;
6541 struct ctl_table tmp = {
6542 .data = &val,
6543 .maxlen = sizeof(val),
6544 .mode = table->mode,
6545 .extra1 = SYSCTL_ZERO,
6546 .extra2 = SYSCTL_ONE,
6547 };
6548
6549 if (write && !capable(CAP_SYS_ADMIN))
6550 return -EPERM;
6551
6552 mutex_lock(&bpf_stats_enabled_mutex);
6553 val = saved_val;
6554 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6555 if (write && !ret && val != saved_val) {
6556 if (val)
6557 static_key_slow_inc(key);
6558 else
6559 static_key_slow_dec(key);
6560 saved_val = val;
6561 }
6562 mutex_unlock(&bpf_stats_enabled_mutex);
6563 return ret;
6564 }
6565
unpriv_ebpf_notify(int new_state)6566 void __weak unpriv_ebpf_notify(int new_state)
6567 {
6568 }
6569
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6570 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6571 void *buffer, size_t *lenp, loff_t *ppos)
6572 {
6573 int ret, unpriv_enable = *(int *)table->data;
6574 bool locked_state = unpriv_enable == 1;
6575 struct ctl_table tmp = *table;
6576
6577 if (write && !capable(CAP_SYS_ADMIN))
6578 return -EPERM;
6579
6580 tmp.data = &unpriv_enable;
6581 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6582 if (write && !ret) {
6583 if (locked_state && unpriv_enable != 1)
6584 return -EPERM;
6585 *(int *)table->data = unpriv_enable;
6586 }
6587
6588 if (write)
6589 unpriv_ebpf_notify(unpriv_enable);
6590
6591 return ret;
6592 }
6593
6594 static const struct ctl_table bpf_syscall_table[] = {
6595 {
6596 .procname = "unprivileged_bpf_disabled",
6597 .data = &sysctl_unprivileged_bpf_disabled,
6598 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
6599 .mode = 0644,
6600 .proc_handler = bpf_unpriv_handler,
6601 .extra1 = SYSCTL_ZERO,
6602 .extra2 = SYSCTL_TWO,
6603 },
6604 {
6605 .procname = "bpf_stats_enabled",
6606 .data = &bpf_stats_enabled_key.key,
6607 .mode = 0644,
6608 .proc_handler = bpf_stats_handler,
6609 },
6610 };
6611
bpf_syscall_sysctl_init(void)6612 static int __init bpf_syscall_sysctl_init(void)
6613 {
6614 register_sysctl_init("kernel", bpf_syscall_table);
6615 return 0;
6616 }
6617 late_initcall(bpf_syscall_sysctl_init);
6618 #endif /* CONFIG_SYSCTL */
6619