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 err = bpf_prog_mark_insn_arrays_ready(prog);
3087 if (err < 0)
3088 goto free_used_maps;
3089
3090 err = bpf_prog_alloc_id(prog);
3091 if (err)
3092 goto free_used_maps;
3093
3094 /* Upon success of bpf_prog_alloc_id(), the BPF prog is
3095 * effectively publicly exposed. However, retrieving via
3096 * bpf_prog_get_fd_by_id() will take another reference,
3097 * therefore it cannot be gone underneath us.
3098 *
3099 * Only for the time /after/ successful bpf_prog_new_fd()
3100 * and before returning to userspace, we might just hold
3101 * one reference and any parallel close on that fd could
3102 * rip everything out. Hence, below notifications must
3103 * happen before bpf_prog_new_fd().
3104 *
3105 * Also, any failure handling from this point onwards must
3106 * be using bpf_prog_put() given the program is exposed.
3107 */
3108 bpf_prog_kallsyms_add(prog);
3109 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
3110 bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3111
3112 err = bpf_prog_new_fd(prog);
3113 if (err < 0)
3114 bpf_prog_put(prog);
3115 return err;
3116
3117 free_used_maps:
3118 /* In case we have subprogs, we need to wait for a grace
3119 * period before we can tear down JIT memory since symbols
3120 * are already exposed under kallsyms.
3121 */
3122 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3123 return err;
3124
3125 free_prog_sec:
3126 security_bpf_prog_free(prog);
3127 free_prog:
3128 free_uid(prog->aux->user);
3129 if (prog->aux->attach_btf)
3130 btf_put(prog->aux->attach_btf);
3131 bpf_prog_free(prog);
3132 put_token:
3133 bpf_token_put(token);
3134 return err;
3135 }
3136
3137 #define BPF_OBJ_LAST_FIELD path_fd
3138
bpf_obj_pin(const union bpf_attr * attr)3139 static int bpf_obj_pin(const union bpf_attr *attr)
3140 {
3141 int path_fd;
3142
3143 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3144 return -EINVAL;
3145
3146 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3147 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3148 return -EINVAL;
3149
3150 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3151 return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3152 u64_to_user_ptr(attr->pathname));
3153 }
3154
bpf_obj_get(const union bpf_attr * attr)3155 static int bpf_obj_get(const union bpf_attr *attr)
3156 {
3157 int path_fd;
3158
3159 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3160 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3161 return -EINVAL;
3162
3163 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3164 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3165 return -EINVAL;
3166
3167 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3168 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3169 attr->file_flags);
3170 }
3171
3172 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3173 * "sleepable" semantics, which normally would mean that BPF link's attach
3174 * hook can dereference link or link's underlying program for some time after
3175 * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3176 * BPF program itself can be non-sleepable, yet, because it's transitively
3177 * reachable through BPF link, its freeing has to be delayed until after RCU
3178 * Tasks Trace GP.
3179 */
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)3180 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3181 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3182 enum bpf_attach_type attach_type, bool sleepable)
3183 {
3184 WARN_ON(ops->dealloc && ops->dealloc_deferred);
3185 atomic64_set(&link->refcnt, 1);
3186 link->type = type;
3187 link->sleepable = sleepable;
3188 link->id = 0;
3189 link->ops = ops;
3190 link->prog = prog;
3191 link->attach_type = attach_type;
3192 }
3193
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)3194 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3195 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3196 enum bpf_attach_type attach_type)
3197 {
3198 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false);
3199 }
3200
bpf_link_free_id(int id)3201 static void bpf_link_free_id(int id)
3202 {
3203 if (!id)
3204 return;
3205
3206 spin_lock_bh(&link_idr_lock);
3207 idr_remove(&link_idr, id);
3208 spin_unlock_bh(&link_idr_lock);
3209 }
3210
3211 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3212 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3213 * anon_inode's release() call. This helper marks bpf_link as
3214 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3215 * is not decremented, it's the responsibility of a calling code that failed
3216 * to complete bpf_link initialization.
3217 * This helper eventually calls link's dealloc callback, but does not call
3218 * link's release callback.
3219 */
bpf_link_cleanup(struct bpf_link_primer * primer)3220 void bpf_link_cleanup(struct bpf_link_primer *primer)
3221 {
3222 primer->link->prog = NULL;
3223 bpf_link_free_id(primer->id);
3224 fput(primer->file);
3225 put_unused_fd(primer->fd);
3226 }
3227
bpf_link_inc(struct bpf_link * link)3228 void bpf_link_inc(struct bpf_link *link)
3229 {
3230 atomic64_inc(&link->refcnt);
3231 }
3232
bpf_link_dealloc(struct bpf_link * link)3233 static void bpf_link_dealloc(struct bpf_link *link)
3234 {
3235 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3236 if (link->prog)
3237 bpf_prog_put(link->prog);
3238
3239 /* free bpf_link and its containing memory */
3240 if (link->ops->dealloc_deferred)
3241 link->ops->dealloc_deferred(link);
3242 else
3243 link->ops->dealloc(link);
3244 }
3245
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3246 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3247 {
3248 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3249
3250 bpf_link_dealloc(link);
3251 }
3252
bpf_link_is_tracepoint(struct bpf_link * link)3253 static bool bpf_link_is_tracepoint(struct bpf_link *link)
3254 {
3255 /*
3256 * Only these combinations support a tracepoint bpf_link.
3257 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use
3258 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see
3259 * bpf_raw_tp_link_attach().
3260 */
3261 return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT ||
3262 (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP);
3263 }
3264
3265 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3266 static void bpf_link_free(struct bpf_link *link)
3267 {
3268 const struct bpf_link_ops *ops = link->ops;
3269
3270 bpf_link_free_id(link->id);
3271 /* detach BPF program, clean up used resources */
3272 if (link->prog)
3273 ops->release(link);
3274 if (ops->dealloc_deferred) {
3275 /*
3276 * Schedule BPF link deallocation, which will only then
3277 * trigger putting BPF program refcount.
3278 * If underlying BPF program is sleepable or BPF link's target
3279 * attach hookpoint is sleepable or otherwise requires RCU GPs
3280 * to ensure link and its underlying BPF program is not
3281 * reachable anymore, we need to first wait for RCU tasks
3282 * trace sync, and then go through "classic" RCU grace period.
3283 *
3284 * For tracepoint BPF links, we need to go through SRCU grace
3285 * period wait instead when non-faultable tracepoint is used. We
3286 * don't need to chain SRCU grace period waits, however, for the
3287 * faultable case, since it exclusively uses RCU Tasks Trace.
3288 */
3289 if (link->sleepable || (link->prog && link->prog->sleepable))
3290 /* RCU Tasks Trace grace period implies RCU grace period. */
3291 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3292 /* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */
3293 else if (bpf_link_is_tracepoint(link))
3294 call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3295 else
3296 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3297 } else if (ops->dealloc) {
3298 bpf_link_dealloc(link);
3299 }
3300 }
3301
bpf_link_put_deferred(struct work_struct * work)3302 static void bpf_link_put_deferred(struct work_struct *work)
3303 {
3304 struct bpf_link *link = container_of(work, struct bpf_link, work);
3305
3306 bpf_link_free(link);
3307 }
3308
3309 /* bpf_link_put might be called from atomic context. It needs to be called
3310 * from sleepable context in order to acquire sleeping locks during the process.
3311 */
bpf_link_put(struct bpf_link * link)3312 void bpf_link_put(struct bpf_link *link)
3313 {
3314 if (!atomic64_dec_and_test(&link->refcnt))
3315 return;
3316
3317 INIT_WORK(&link->work, bpf_link_put_deferred);
3318 schedule_work(&link->work);
3319 }
3320 EXPORT_SYMBOL(bpf_link_put);
3321
bpf_link_put_direct(struct bpf_link * link)3322 static void bpf_link_put_direct(struct bpf_link *link)
3323 {
3324 if (!atomic64_dec_and_test(&link->refcnt))
3325 return;
3326 bpf_link_free(link);
3327 }
3328
bpf_link_release(struct inode * inode,struct file * filp)3329 static int bpf_link_release(struct inode *inode, struct file *filp)
3330 {
3331 struct bpf_link *link = filp->private_data;
3332
3333 bpf_link_put_direct(link);
3334 return 0;
3335 }
3336
3337 #ifdef CONFIG_PROC_FS
3338 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3339 #define BPF_MAP_TYPE(_id, _ops)
3340 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3341 static const char *bpf_link_type_strs[] = {
3342 [BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3343 #include <linux/bpf_types.h>
3344 };
3345 #undef BPF_PROG_TYPE
3346 #undef BPF_MAP_TYPE
3347 #undef BPF_LINK_TYPE
3348
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3349 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3350 {
3351 const struct bpf_link *link = filp->private_data;
3352 const struct bpf_prog *prog = link->prog;
3353 enum bpf_link_type type = link->type;
3354 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3355
3356 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3357 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI)
3358 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ?
3359 "kretprobe_multi" : "kprobe_multi");
3360 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI)
3361 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ?
3362 "uretprobe_multi" : "uprobe_multi");
3363 else
3364 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3365 } else {
3366 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3367 seq_printf(m, "link_type:\t<%u>\n", type);
3368 }
3369 seq_printf(m, "link_id:\t%u\n", link->id);
3370
3371 if (prog) {
3372 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3373 seq_printf(m,
3374 "prog_tag:\t%s\n"
3375 "prog_id:\t%u\n",
3376 prog_tag,
3377 prog->aux->id);
3378 }
3379 if (link->ops->show_fdinfo)
3380 link->ops->show_fdinfo(link, m);
3381 }
3382 #endif
3383
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3384 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3385 {
3386 struct bpf_link *link = file->private_data;
3387
3388 return link->ops->poll(file, pts);
3389 }
3390
3391 static const struct file_operations bpf_link_fops = {
3392 #ifdef CONFIG_PROC_FS
3393 .show_fdinfo = bpf_link_show_fdinfo,
3394 #endif
3395 .release = bpf_link_release,
3396 .read = bpf_dummy_read,
3397 .write = bpf_dummy_write,
3398 };
3399
3400 static const struct file_operations bpf_link_fops_poll = {
3401 #ifdef CONFIG_PROC_FS
3402 .show_fdinfo = bpf_link_show_fdinfo,
3403 #endif
3404 .release = bpf_link_release,
3405 .read = bpf_dummy_read,
3406 .write = bpf_dummy_write,
3407 .poll = bpf_link_poll,
3408 };
3409
bpf_link_alloc_id(struct bpf_link * link)3410 static int bpf_link_alloc_id(struct bpf_link *link)
3411 {
3412 int id;
3413
3414 idr_preload(GFP_KERNEL);
3415 spin_lock_bh(&link_idr_lock);
3416 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3417 spin_unlock_bh(&link_idr_lock);
3418 idr_preload_end();
3419
3420 return id;
3421 }
3422
3423 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3424 * reserving unused FD and allocating ID from link_idr. This is to be paired
3425 * with bpf_link_settle() to install FD and ID and expose bpf_link to
3426 * user-space, if bpf_link is successfully attached. If not, bpf_link and
3427 * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3428 * transient state is passed around in struct bpf_link_primer.
3429 * This is preferred way to create and initialize bpf_link, especially when
3430 * there are complicated and expensive operations in between creating bpf_link
3431 * itself and attaching it to BPF hook. By using bpf_link_prime() and
3432 * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3433 * expensive (and potentially failing) roll back operations in a rare case
3434 * that file, FD, or ID can't be allocated.
3435 */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3436 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3437 {
3438 struct file *file;
3439 int fd, id;
3440
3441 fd = get_unused_fd_flags(O_CLOEXEC);
3442 if (fd < 0)
3443 return fd;
3444
3445
3446 id = bpf_link_alloc_id(link);
3447 if (id < 0) {
3448 put_unused_fd(fd);
3449 return id;
3450 }
3451
3452 file = anon_inode_getfile("bpf_link",
3453 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3454 link, O_CLOEXEC);
3455 if (IS_ERR(file)) {
3456 bpf_link_free_id(id);
3457 put_unused_fd(fd);
3458 return PTR_ERR(file);
3459 }
3460
3461 primer->link = link;
3462 primer->file = file;
3463 primer->fd = fd;
3464 primer->id = id;
3465 return 0;
3466 }
3467
bpf_link_settle(struct bpf_link_primer * primer)3468 int bpf_link_settle(struct bpf_link_primer *primer)
3469 {
3470 /* make bpf_link fetchable by ID */
3471 spin_lock_bh(&link_idr_lock);
3472 primer->link->id = primer->id;
3473 spin_unlock_bh(&link_idr_lock);
3474 /* make bpf_link fetchable by FD */
3475 fd_install(primer->fd, primer->file);
3476 /* pass through installed FD */
3477 return primer->fd;
3478 }
3479
bpf_link_new_fd(struct bpf_link * link)3480 int bpf_link_new_fd(struct bpf_link *link)
3481 {
3482 return anon_inode_getfd("bpf-link",
3483 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3484 link, O_CLOEXEC);
3485 }
3486
bpf_link_get_from_fd(u32 ufd)3487 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3488 {
3489 CLASS(fd, f)(ufd);
3490 struct bpf_link *link;
3491
3492 if (fd_empty(f))
3493 return ERR_PTR(-EBADF);
3494 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3495 return ERR_PTR(-EINVAL);
3496
3497 link = fd_file(f)->private_data;
3498 bpf_link_inc(link);
3499 return link;
3500 }
3501 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL");
3502
bpf_tracing_link_release(struct bpf_link * link)3503 static void bpf_tracing_link_release(struct bpf_link *link)
3504 {
3505 struct bpf_tracing_link *tr_link =
3506 container_of(link, struct bpf_tracing_link, link.link);
3507
3508 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3509 tr_link->trampoline,
3510 tr_link->tgt_prog));
3511
3512 bpf_trampoline_put(tr_link->trampoline);
3513
3514 /* tgt_prog is NULL if target is a kernel function */
3515 if (tr_link->tgt_prog)
3516 bpf_prog_put(tr_link->tgt_prog);
3517 }
3518
bpf_tracing_link_dealloc(struct bpf_link * link)3519 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3520 {
3521 struct bpf_tracing_link *tr_link =
3522 container_of(link, struct bpf_tracing_link, link.link);
3523
3524 kfree(tr_link);
3525 }
3526
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3527 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3528 struct seq_file *seq)
3529 {
3530 struct bpf_tracing_link *tr_link =
3531 container_of(link, struct bpf_tracing_link, link.link);
3532 u32 target_btf_id, target_obj_id;
3533
3534 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3535 &target_obj_id, &target_btf_id);
3536 seq_printf(seq,
3537 "attach_type:\t%d\n"
3538 "target_obj_id:\t%u\n"
3539 "target_btf_id:\t%u\n"
3540 "cookie:\t%llu\n",
3541 link->attach_type,
3542 target_obj_id,
3543 target_btf_id,
3544 tr_link->link.cookie);
3545 }
3546
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3547 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3548 struct bpf_link_info *info)
3549 {
3550 struct bpf_tracing_link *tr_link =
3551 container_of(link, struct bpf_tracing_link, link.link);
3552
3553 info->tracing.attach_type = link->attach_type;
3554 info->tracing.cookie = tr_link->link.cookie;
3555 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3556 &info->tracing.target_obj_id,
3557 &info->tracing.target_btf_id);
3558
3559 return 0;
3560 }
3561
3562 static const struct bpf_link_ops bpf_tracing_link_lops = {
3563 .release = bpf_tracing_link_release,
3564 .dealloc = bpf_tracing_link_dealloc,
3565 .show_fdinfo = bpf_tracing_link_show_fdinfo,
3566 .fill_link_info = bpf_tracing_link_fill_link_info,
3567 };
3568
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie,enum bpf_attach_type attach_type)3569 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3570 int tgt_prog_fd,
3571 u32 btf_id,
3572 u64 bpf_cookie,
3573 enum bpf_attach_type attach_type)
3574 {
3575 struct bpf_link_primer link_primer;
3576 struct bpf_prog *tgt_prog = NULL;
3577 struct bpf_trampoline *tr = NULL;
3578 struct bpf_tracing_link *link;
3579 u64 key = 0;
3580 int err;
3581
3582 switch (prog->type) {
3583 case BPF_PROG_TYPE_TRACING:
3584 if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3585 prog->expected_attach_type != BPF_TRACE_FEXIT &&
3586 prog->expected_attach_type != BPF_TRACE_FSESSION &&
3587 prog->expected_attach_type != BPF_MODIFY_RETURN) {
3588 err = -EINVAL;
3589 goto out_put_prog;
3590 }
3591 break;
3592 case BPF_PROG_TYPE_EXT:
3593 if (prog->expected_attach_type != 0) {
3594 err = -EINVAL;
3595 goto out_put_prog;
3596 }
3597 break;
3598 case BPF_PROG_TYPE_LSM:
3599 if (prog->expected_attach_type != BPF_LSM_MAC) {
3600 err = -EINVAL;
3601 goto out_put_prog;
3602 }
3603 break;
3604 default:
3605 err = -EINVAL;
3606 goto out_put_prog;
3607 }
3608
3609 if (!!tgt_prog_fd != !!btf_id) {
3610 err = -EINVAL;
3611 goto out_put_prog;
3612 }
3613
3614 if (tgt_prog_fd) {
3615 /*
3616 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3617 * part would be changed to implement the same for
3618 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3619 * attach_tracing_prog flag is set.
3620 */
3621 if (prog->type != BPF_PROG_TYPE_EXT) {
3622 err = -EINVAL;
3623 goto out_put_prog;
3624 }
3625
3626 tgt_prog = bpf_prog_get(tgt_prog_fd);
3627 if (IS_ERR(tgt_prog)) {
3628 err = PTR_ERR(tgt_prog);
3629 tgt_prog = NULL;
3630 goto out_put_prog;
3631 }
3632
3633 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3634 }
3635
3636 if (prog->expected_attach_type == BPF_TRACE_FSESSION) {
3637 struct bpf_fsession_link *fslink;
3638
3639 fslink = kzalloc_obj(*fslink, GFP_USER);
3640 if (fslink) {
3641 bpf_link_init(&fslink->fexit.link, BPF_LINK_TYPE_TRACING,
3642 &bpf_tracing_link_lops, prog, attach_type);
3643 fslink->fexit.cookie = bpf_cookie;
3644 link = &fslink->link;
3645 } else {
3646 link = NULL;
3647 }
3648 } else {
3649 link = kzalloc_obj(*link, GFP_USER);
3650 }
3651 if (!link) {
3652 err = -ENOMEM;
3653 goto out_put_prog;
3654 }
3655 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3656 &bpf_tracing_link_lops, prog, attach_type);
3657
3658 link->link.cookie = bpf_cookie;
3659
3660 mutex_lock(&prog->aux->dst_mutex);
3661
3662 /* There are a few possible cases here:
3663 *
3664 * - if prog->aux->dst_trampoline is set, the program was just loaded
3665 * and not yet attached to anything, so we can use the values stored
3666 * in prog->aux
3667 *
3668 * - if prog->aux->dst_trampoline is NULL, the program has already been
3669 * attached to a target and its initial target was cleared (below)
3670 *
3671 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3672 * target_btf_id using the link_create API.
3673 *
3674 * - if tgt_prog == NULL when this function was called using the old
3675 * raw_tracepoint_open API, and we need a target from prog->aux
3676 *
3677 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3678 * was detached and is going for re-attachment.
3679 *
3680 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3681 * are NULL, then program was already attached and user did not provide
3682 * tgt_prog_fd so we have no way to find out or create trampoline
3683 */
3684 if (!prog->aux->dst_trampoline && !tgt_prog) {
3685 /*
3686 * Allow re-attach for TRACING and LSM programs. If it's
3687 * currently linked, bpf_trampoline_link_prog will fail.
3688 * EXT programs need to specify tgt_prog_fd, so they
3689 * re-attach in separate code path.
3690 */
3691 if (prog->type != BPF_PROG_TYPE_TRACING &&
3692 prog->type != BPF_PROG_TYPE_LSM) {
3693 err = -EINVAL;
3694 goto out_unlock;
3695 }
3696 /* We can allow re-attach only if we have valid attach_btf. */
3697 if (!prog->aux->attach_btf) {
3698 err = -EINVAL;
3699 goto out_unlock;
3700 }
3701 btf_id = prog->aux->attach_btf_id;
3702 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3703 }
3704
3705 if (!prog->aux->dst_trampoline ||
3706 (key && key != prog->aux->dst_trampoline->key)) {
3707 /* If there is no saved target, or the specified target is
3708 * different from the destination specified at load time, we
3709 * need a new trampoline and a check for compatibility
3710 */
3711 struct bpf_attach_target_info tgt_info = {};
3712
3713 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3714 &tgt_info);
3715 if (err)
3716 goto out_unlock;
3717
3718 if (tgt_info.tgt_mod) {
3719 module_put(prog->aux->mod);
3720 prog->aux->mod = tgt_info.tgt_mod;
3721 }
3722
3723 tr = bpf_trampoline_get(key, &tgt_info);
3724 if (!tr) {
3725 err = -ENOMEM;
3726 goto out_unlock;
3727 }
3728 } else {
3729 /* The caller didn't specify a target, or the target was the
3730 * same as the destination supplied during program load. This
3731 * means we can reuse the trampoline and reference from program
3732 * load time, and there is no need to allocate a new one. This
3733 * can only happen once for any program, as the saved values in
3734 * prog->aux are cleared below.
3735 */
3736 tr = prog->aux->dst_trampoline;
3737 tgt_prog = prog->aux->dst_prog;
3738 }
3739 /*
3740 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true
3741 * freplace prog. Without this check, kprobe_write_ctx=true freplace
3742 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and
3743 * then modify the registers of the kprobe prog's target kernel
3744 * function.
3745 *
3746 * This also blocks the combination of uprobe+freplace, because it is
3747 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe
3748 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by
3749 * the target perf event flags in __perf_event_set_bpf_prog().
3750 */
3751 if (prog->type == BPF_PROG_TYPE_EXT &&
3752 prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) {
3753 err = -EINVAL;
3754 goto out_unlock;
3755 }
3756
3757 err = bpf_link_prime(&link->link.link, &link_primer);
3758 if (err)
3759 goto out_unlock;
3760
3761 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3762 if (err) {
3763 bpf_link_cleanup(&link_primer);
3764 link = NULL;
3765 goto out_unlock;
3766 }
3767
3768 link->tgt_prog = tgt_prog;
3769 link->trampoline = tr;
3770
3771 /* Always clear the trampoline and target prog from prog->aux to make
3772 * sure the original attach destination is not kept alive after a
3773 * program is (re-)attached to another target.
3774 */
3775 if (prog->aux->dst_prog &&
3776 (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3777 /* got extra prog ref from syscall, or attaching to different prog */
3778 bpf_prog_put(prog->aux->dst_prog);
3779 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3780 /* we allocated a new trampoline, so free the old one */
3781 bpf_trampoline_put(prog->aux->dst_trampoline);
3782
3783 prog->aux->dst_prog = NULL;
3784 prog->aux->dst_trampoline = NULL;
3785 mutex_unlock(&prog->aux->dst_mutex);
3786
3787 return bpf_link_settle(&link_primer);
3788 out_unlock:
3789 if (tr && tr != prog->aux->dst_trampoline)
3790 bpf_trampoline_put(tr);
3791 mutex_unlock(&prog->aux->dst_mutex);
3792 kfree(link);
3793 out_put_prog:
3794 if (tgt_prog_fd && tgt_prog)
3795 bpf_prog_put(tgt_prog);
3796 return err;
3797 }
3798
bpf_raw_tp_link_release(struct bpf_link * link)3799 static void bpf_raw_tp_link_release(struct bpf_link *link)
3800 {
3801 struct bpf_raw_tp_link *raw_tp =
3802 container_of(link, struct bpf_raw_tp_link, link);
3803
3804 bpf_probe_unregister(raw_tp->btp, raw_tp);
3805 bpf_put_raw_tracepoint(raw_tp->btp);
3806 }
3807
bpf_raw_tp_link_dealloc(struct bpf_link * link)3808 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3809 {
3810 struct bpf_raw_tp_link *raw_tp =
3811 container_of(link, struct bpf_raw_tp_link, link);
3812
3813 kfree(raw_tp);
3814 }
3815
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3816 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3817 struct seq_file *seq)
3818 {
3819 struct bpf_raw_tp_link *raw_tp_link =
3820 container_of(link, struct bpf_raw_tp_link, link);
3821
3822 seq_printf(seq,
3823 "tp_name:\t%s\n"
3824 "cookie:\t%llu\n",
3825 raw_tp_link->btp->tp->name,
3826 raw_tp_link->cookie);
3827 }
3828
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3829 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3830 u32 len)
3831 {
3832 if (ulen >= len + 1) {
3833 if (copy_to_user(ubuf, buf, len + 1))
3834 return -EFAULT;
3835 } else {
3836 char zero = '\0';
3837
3838 if (copy_to_user(ubuf, buf, ulen - 1))
3839 return -EFAULT;
3840 if (put_user(zero, ubuf + ulen - 1))
3841 return -EFAULT;
3842 return -ENOSPC;
3843 }
3844
3845 return 0;
3846 }
3847
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3848 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3849 struct bpf_link_info *info)
3850 {
3851 struct bpf_raw_tp_link *raw_tp_link =
3852 container_of(link, struct bpf_raw_tp_link, link);
3853 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3854 const char *tp_name = raw_tp_link->btp->tp->name;
3855 u32 ulen = info->raw_tracepoint.tp_name_len;
3856 size_t tp_len = strlen(tp_name);
3857
3858 if (!ulen ^ !ubuf)
3859 return -EINVAL;
3860
3861 info->raw_tracepoint.tp_name_len = tp_len + 1;
3862 info->raw_tracepoint.cookie = raw_tp_link->cookie;
3863
3864 if (!ubuf)
3865 return 0;
3866
3867 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3868 }
3869
3870 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3871 .release = bpf_raw_tp_link_release,
3872 .dealloc_deferred = bpf_raw_tp_link_dealloc,
3873 .show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3874 .fill_link_info = bpf_raw_tp_link_fill_link_info,
3875 };
3876
3877 #ifdef CONFIG_PERF_EVENTS
3878 struct bpf_perf_link {
3879 struct bpf_link link;
3880 struct file *perf_file;
3881 };
3882
bpf_perf_link_release(struct bpf_link * link)3883 static void bpf_perf_link_release(struct bpf_link *link)
3884 {
3885 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3886 struct perf_event *event = perf_link->perf_file->private_data;
3887
3888 perf_event_free_bpf_prog(event);
3889 fput(perf_link->perf_file);
3890 }
3891
bpf_perf_link_dealloc(struct bpf_link * link)3892 static void bpf_perf_link_dealloc(struct bpf_link *link)
3893 {
3894 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3895
3896 kfree(perf_link);
3897 }
3898
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)3899 static int bpf_perf_link_fill_common(const struct perf_event *event,
3900 char __user *uname, u32 *ulenp,
3901 u64 *probe_offset, u64 *probe_addr,
3902 u32 *fd_type, unsigned long *missed)
3903 {
3904 const char *buf;
3905 u32 prog_id, ulen;
3906 size_t len;
3907 int err;
3908
3909 ulen = *ulenp;
3910 if (!ulen ^ !uname)
3911 return -EINVAL;
3912
3913 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3914 probe_offset, probe_addr, missed);
3915 if (err)
3916 return err;
3917
3918 if (buf) {
3919 len = strlen(buf);
3920 *ulenp = len + 1;
3921 } else {
3922 *ulenp = 1;
3923 }
3924 if (!uname)
3925 return 0;
3926
3927 if (buf) {
3928 err = bpf_copy_to_user(uname, buf, ulen, len);
3929 if (err)
3930 return err;
3931 } else {
3932 char zero = '\0';
3933
3934 if (put_user(zero, uname))
3935 return -EFAULT;
3936 }
3937 return 0;
3938 }
3939
3940 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3941 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3942 struct bpf_link_info *info)
3943 {
3944 unsigned long missed;
3945 char __user *uname;
3946 u64 addr, offset;
3947 u32 ulen, type;
3948 int err;
3949
3950 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3951 ulen = info->perf_event.kprobe.name_len;
3952 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3953 &type, &missed);
3954 if (err)
3955 return err;
3956 if (type == BPF_FD_TYPE_KRETPROBE)
3957 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3958 else
3959 info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3960 info->perf_event.kprobe.name_len = ulen;
3961 info->perf_event.kprobe.offset = offset;
3962 info->perf_event.kprobe.missed = missed;
3963 if (!kallsyms_show_value(current_cred()))
3964 addr = 0;
3965 info->perf_event.kprobe.addr = addr;
3966 info->perf_event.kprobe.cookie = event->bpf_cookie;
3967 return 0;
3968 }
3969
bpf_perf_link_fdinfo_kprobe(const struct perf_event * event,struct seq_file * seq)3970 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event,
3971 struct seq_file *seq)
3972 {
3973 const char *name;
3974 int err;
3975 u32 prog_id, type;
3976 u64 offset, addr;
3977 unsigned long missed;
3978
3979 err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
3980 &offset, &addr, &missed);
3981 if (err)
3982 return;
3983
3984 seq_printf(seq,
3985 "name:\t%s\n"
3986 "offset:\t%#llx\n"
3987 "missed:\t%lu\n"
3988 "addr:\t%#llx\n"
3989 "event_type:\t%s\n"
3990 "cookie:\t%llu\n",
3991 name, offset, missed, addr,
3992 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe",
3993 event->bpf_cookie);
3994 }
3995 #endif
3996
3997 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3998 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3999 struct bpf_link_info *info)
4000 {
4001 u64 ref_ctr_offset, offset;
4002 char __user *uname;
4003 u32 ulen, type;
4004 int err;
4005
4006 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
4007 ulen = info->perf_event.uprobe.name_len;
4008 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset,
4009 &type, NULL);
4010 if (err)
4011 return err;
4012
4013 if (type == BPF_FD_TYPE_URETPROBE)
4014 info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
4015 else
4016 info->perf_event.type = BPF_PERF_EVENT_UPROBE;
4017 info->perf_event.uprobe.name_len = ulen;
4018 info->perf_event.uprobe.offset = offset;
4019 info->perf_event.uprobe.cookie = event->bpf_cookie;
4020 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset;
4021 return 0;
4022 }
4023
bpf_perf_link_fdinfo_uprobe(const struct perf_event * event,struct seq_file * seq)4024 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event,
4025 struct seq_file *seq)
4026 {
4027 const char *name;
4028 int err;
4029 u32 prog_id, type;
4030 u64 offset, ref_ctr_offset;
4031 unsigned long missed;
4032
4033 err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
4034 &offset, &ref_ctr_offset, &missed);
4035 if (err)
4036 return;
4037
4038 seq_printf(seq,
4039 "name:\t%s\n"
4040 "offset:\t%#llx\n"
4041 "ref_ctr_offset:\t%#llx\n"
4042 "event_type:\t%s\n"
4043 "cookie:\t%llu\n",
4044 name, offset, ref_ctr_offset,
4045 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe",
4046 event->bpf_cookie);
4047 }
4048 #endif
4049
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)4050 static int bpf_perf_link_fill_probe(const struct perf_event *event,
4051 struct bpf_link_info *info)
4052 {
4053 #ifdef CONFIG_KPROBE_EVENTS
4054 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4055 return bpf_perf_link_fill_kprobe(event, info);
4056 #endif
4057 #ifdef CONFIG_UPROBE_EVENTS
4058 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4059 return bpf_perf_link_fill_uprobe(event, info);
4060 #endif
4061 return -EOPNOTSUPP;
4062 }
4063
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)4064 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
4065 struct bpf_link_info *info)
4066 {
4067 char __user *uname;
4068 u32 ulen;
4069 int err;
4070
4071 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
4072 ulen = info->perf_event.tracepoint.name_len;
4073 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
4074 if (err)
4075 return err;
4076
4077 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
4078 info->perf_event.tracepoint.name_len = ulen;
4079 info->perf_event.tracepoint.cookie = event->bpf_cookie;
4080 return 0;
4081 }
4082
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)4083 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
4084 struct bpf_link_info *info)
4085 {
4086 info->perf_event.event.type = event->attr.type;
4087 info->perf_event.event.config = event->attr.config;
4088 info->perf_event.event.cookie = event->bpf_cookie;
4089 info->perf_event.type = BPF_PERF_EVENT_EVENT;
4090 return 0;
4091 }
4092
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)4093 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
4094 struct bpf_link_info *info)
4095 {
4096 struct bpf_perf_link *perf_link;
4097 const struct perf_event *event;
4098
4099 perf_link = container_of(link, struct bpf_perf_link, link);
4100 event = perf_get_event(perf_link->perf_file);
4101 if (IS_ERR(event))
4102 return PTR_ERR(event);
4103
4104 switch (event->prog->type) {
4105 case BPF_PROG_TYPE_PERF_EVENT:
4106 return bpf_perf_link_fill_perf_event(event, info);
4107 case BPF_PROG_TYPE_TRACEPOINT:
4108 return bpf_perf_link_fill_tracepoint(event, info);
4109 case BPF_PROG_TYPE_KPROBE:
4110 return bpf_perf_link_fill_probe(event, info);
4111 default:
4112 return -EOPNOTSUPP;
4113 }
4114 }
4115
bpf_perf_event_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4116 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event,
4117 struct seq_file *seq)
4118 {
4119 seq_printf(seq,
4120 "type:\t%u\n"
4121 "config:\t%llu\n"
4122 "event_type:\t%s\n"
4123 "cookie:\t%llu\n",
4124 event->attr.type, event->attr.config,
4125 "event", event->bpf_cookie);
4126 }
4127
bpf_tracepoint_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4128 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event,
4129 struct seq_file *seq)
4130 {
4131 int err;
4132 const char *name;
4133 u32 prog_id;
4134
4135 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL,
4136 NULL, NULL);
4137 if (err)
4138 return;
4139
4140 seq_printf(seq,
4141 "tp_name:\t%s\n"
4142 "event_type:\t%s\n"
4143 "cookie:\t%llu\n",
4144 name, "tracepoint", event->bpf_cookie);
4145 }
4146
bpf_probe_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4147 static void bpf_probe_link_show_fdinfo(const struct perf_event *event,
4148 struct seq_file *seq)
4149 {
4150 #ifdef CONFIG_KPROBE_EVENTS
4151 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4152 return bpf_perf_link_fdinfo_kprobe(event, seq);
4153 #endif
4154
4155 #ifdef CONFIG_UPROBE_EVENTS
4156 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4157 return bpf_perf_link_fdinfo_uprobe(event, seq);
4158 #endif
4159 }
4160
bpf_perf_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)4161 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link,
4162 struct seq_file *seq)
4163 {
4164 struct bpf_perf_link *perf_link;
4165 const struct perf_event *event;
4166
4167 perf_link = container_of(link, struct bpf_perf_link, link);
4168 event = perf_get_event(perf_link->perf_file);
4169 if (IS_ERR(event))
4170 return;
4171
4172 switch (event->prog->type) {
4173 case BPF_PROG_TYPE_PERF_EVENT:
4174 return bpf_perf_event_link_show_fdinfo(event, seq);
4175 case BPF_PROG_TYPE_TRACEPOINT:
4176 return bpf_tracepoint_link_show_fdinfo(event, seq);
4177 case BPF_PROG_TYPE_KPROBE:
4178 return bpf_probe_link_show_fdinfo(event, seq);
4179 default:
4180 return;
4181 }
4182 }
4183
4184 static const struct bpf_link_ops bpf_perf_link_lops = {
4185 .release = bpf_perf_link_release,
4186 .dealloc = bpf_perf_link_dealloc,
4187 .fill_link_info = bpf_perf_link_fill_link_info,
4188 .show_fdinfo = bpf_perf_link_show_fdinfo,
4189 };
4190
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4191 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4192 {
4193 struct bpf_link_primer link_primer;
4194 struct bpf_perf_link *link;
4195 struct perf_event *event;
4196 struct file *perf_file;
4197 int err;
4198
4199 if (attr->link_create.flags)
4200 return -EINVAL;
4201
4202 perf_file = perf_event_get(attr->link_create.target_fd);
4203 if (IS_ERR(perf_file))
4204 return PTR_ERR(perf_file);
4205
4206 link = kzalloc_obj(*link, GFP_USER);
4207 if (!link) {
4208 err = -ENOMEM;
4209 goto out_put_file;
4210 }
4211 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog,
4212 attr->link_create.attach_type);
4213 link->perf_file = perf_file;
4214
4215 err = bpf_link_prime(&link->link, &link_primer);
4216 if (err) {
4217 kfree(link);
4218 goto out_put_file;
4219 }
4220
4221 event = perf_file->private_data;
4222 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
4223 if (err) {
4224 bpf_link_cleanup(&link_primer);
4225 goto out_put_file;
4226 }
4227 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
4228 bpf_prog_inc(prog);
4229
4230 return bpf_link_settle(&link_primer);
4231
4232 out_put_file:
4233 fput(perf_file);
4234 return err;
4235 }
4236 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4237 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4238 {
4239 return -EOPNOTSUPP;
4240 }
4241 #endif /* CONFIG_PERF_EVENTS */
4242
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie,enum bpf_attach_type attach_type)4243 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
4244 const char __user *user_tp_name, u64 cookie,
4245 enum bpf_attach_type attach_type)
4246 {
4247 struct bpf_link_primer link_primer;
4248 struct bpf_raw_tp_link *link;
4249 struct bpf_raw_event_map *btp;
4250 const char *tp_name;
4251 char buf[128];
4252 int err;
4253
4254 switch (prog->type) {
4255 case BPF_PROG_TYPE_TRACING:
4256 case BPF_PROG_TYPE_EXT:
4257 case BPF_PROG_TYPE_LSM:
4258 if (user_tp_name)
4259 /* The attach point for this category of programs
4260 * should be specified via btf_id during program load.
4261 */
4262 return -EINVAL;
4263 if (prog->type == BPF_PROG_TYPE_TRACING &&
4264 prog->expected_attach_type == BPF_TRACE_RAW_TP) {
4265 tp_name = prog->aux->attach_func_name;
4266 break;
4267 }
4268 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type);
4269 case BPF_PROG_TYPE_RAW_TRACEPOINT:
4270 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
4271 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
4272 return -EFAULT;
4273 buf[sizeof(buf) - 1] = 0;
4274 tp_name = buf;
4275 break;
4276 default:
4277 return -EINVAL;
4278 }
4279
4280 btp = bpf_get_raw_tracepoint(tp_name);
4281 if (!btp)
4282 return -ENOENT;
4283
4284 link = kzalloc_obj(*link, GFP_USER);
4285 if (!link) {
4286 err = -ENOMEM;
4287 goto out_put_btp;
4288 }
4289 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
4290 &bpf_raw_tp_link_lops, prog, attach_type,
4291 tracepoint_is_faultable(btp->tp));
4292 link->btp = btp;
4293 link->cookie = cookie;
4294
4295 err = bpf_link_prime(&link->link, &link_primer);
4296 if (err) {
4297 kfree(link);
4298 goto out_put_btp;
4299 }
4300
4301 err = bpf_probe_register(link->btp, link);
4302 if (err) {
4303 bpf_link_cleanup(&link_primer);
4304 goto out_put_btp;
4305 }
4306
4307 return bpf_link_settle(&link_primer);
4308
4309 out_put_btp:
4310 bpf_put_raw_tracepoint(btp);
4311 return err;
4312 }
4313
4314 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4315
bpf_raw_tracepoint_open(const union bpf_attr * attr)4316 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4317 {
4318 struct bpf_prog *prog;
4319 void __user *tp_name;
4320 __u64 cookie;
4321 int fd;
4322
4323 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4324 return -EINVAL;
4325
4326 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4327 if (IS_ERR(prog))
4328 return PTR_ERR(prog);
4329
4330 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4331 cookie = attr->raw_tracepoint.cookie;
4332 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type);
4333 if (fd < 0)
4334 bpf_prog_put(prog);
4335 return fd;
4336 }
4337
4338 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4339 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4340 {
4341 switch (attach_type) {
4342 case BPF_CGROUP_INET_INGRESS:
4343 case BPF_CGROUP_INET_EGRESS:
4344 return BPF_PROG_TYPE_CGROUP_SKB;
4345 case BPF_CGROUP_INET_SOCK_CREATE:
4346 case BPF_CGROUP_INET_SOCK_RELEASE:
4347 case BPF_CGROUP_INET4_POST_BIND:
4348 case BPF_CGROUP_INET6_POST_BIND:
4349 return BPF_PROG_TYPE_CGROUP_SOCK;
4350 case BPF_CGROUP_INET4_BIND:
4351 case BPF_CGROUP_INET6_BIND:
4352 case BPF_CGROUP_INET4_CONNECT:
4353 case BPF_CGROUP_INET6_CONNECT:
4354 case BPF_CGROUP_UNIX_CONNECT:
4355 case BPF_CGROUP_INET4_GETPEERNAME:
4356 case BPF_CGROUP_INET6_GETPEERNAME:
4357 case BPF_CGROUP_UNIX_GETPEERNAME:
4358 case BPF_CGROUP_INET4_GETSOCKNAME:
4359 case BPF_CGROUP_INET6_GETSOCKNAME:
4360 case BPF_CGROUP_UNIX_GETSOCKNAME:
4361 case BPF_CGROUP_UDP4_SENDMSG:
4362 case BPF_CGROUP_UDP6_SENDMSG:
4363 case BPF_CGROUP_UNIX_SENDMSG:
4364 case BPF_CGROUP_UDP4_RECVMSG:
4365 case BPF_CGROUP_UDP6_RECVMSG:
4366 case BPF_CGROUP_UNIX_RECVMSG:
4367 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4368 case BPF_CGROUP_SOCK_OPS:
4369 return BPF_PROG_TYPE_SOCK_OPS;
4370 case BPF_CGROUP_DEVICE:
4371 return BPF_PROG_TYPE_CGROUP_DEVICE;
4372 case BPF_SK_MSG_VERDICT:
4373 return BPF_PROG_TYPE_SK_MSG;
4374 case BPF_SK_SKB_STREAM_PARSER:
4375 case BPF_SK_SKB_STREAM_VERDICT:
4376 case BPF_SK_SKB_VERDICT:
4377 return BPF_PROG_TYPE_SK_SKB;
4378 case BPF_LIRC_MODE2:
4379 return BPF_PROG_TYPE_LIRC_MODE2;
4380 case BPF_FLOW_DISSECTOR:
4381 return BPF_PROG_TYPE_FLOW_DISSECTOR;
4382 case BPF_CGROUP_SYSCTL:
4383 return BPF_PROG_TYPE_CGROUP_SYSCTL;
4384 case BPF_CGROUP_GETSOCKOPT:
4385 case BPF_CGROUP_SETSOCKOPT:
4386 return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4387 case BPF_TRACE_ITER:
4388 case BPF_TRACE_RAW_TP:
4389 case BPF_TRACE_FENTRY:
4390 case BPF_TRACE_FEXIT:
4391 case BPF_TRACE_FSESSION:
4392 case BPF_MODIFY_RETURN:
4393 return BPF_PROG_TYPE_TRACING;
4394 case BPF_LSM_MAC:
4395 return BPF_PROG_TYPE_LSM;
4396 case BPF_SK_LOOKUP:
4397 return BPF_PROG_TYPE_SK_LOOKUP;
4398 case BPF_XDP:
4399 return BPF_PROG_TYPE_XDP;
4400 case BPF_LSM_CGROUP:
4401 return BPF_PROG_TYPE_LSM;
4402 case BPF_TCX_INGRESS:
4403 case BPF_TCX_EGRESS:
4404 case BPF_NETKIT_PRIMARY:
4405 case BPF_NETKIT_PEER:
4406 return BPF_PROG_TYPE_SCHED_CLS;
4407 default:
4408 return BPF_PROG_TYPE_UNSPEC;
4409 }
4410 }
4411
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4412 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4413 enum bpf_attach_type attach_type)
4414 {
4415 enum bpf_prog_type ptype;
4416
4417 switch (prog->type) {
4418 case BPF_PROG_TYPE_CGROUP_SOCK:
4419 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4420 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4421 case BPF_PROG_TYPE_SK_LOOKUP:
4422 return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4423 case BPF_PROG_TYPE_CGROUP_SKB:
4424 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4425 /* cg-skb progs can be loaded by unpriv user.
4426 * check permissions at attach time.
4427 */
4428 return -EPERM;
4429
4430 ptype = attach_type_to_prog_type(attach_type);
4431 if (prog->type != ptype)
4432 return -EINVAL;
4433
4434 return prog->enforce_expected_attach_type &&
4435 prog->expected_attach_type != attach_type ?
4436 -EINVAL : 0;
4437 case BPF_PROG_TYPE_EXT:
4438 return 0;
4439 case BPF_PROG_TYPE_NETFILTER:
4440 if (attach_type != BPF_NETFILTER)
4441 return -EINVAL;
4442 return 0;
4443 case BPF_PROG_TYPE_PERF_EVENT:
4444 case BPF_PROG_TYPE_TRACEPOINT:
4445 if (attach_type != BPF_PERF_EVENT)
4446 return -EINVAL;
4447 return 0;
4448 case BPF_PROG_TYPE_KPROBE:
4449 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4450 attach_type != BPF_TRACE_KPROBE_MULTI)
4451 return -EINVAL;
4452 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4453 attach_type != BPF_TRACE_KPROBE_SESSION)
4454 return -EINVAL;
4455 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4456 attach_type != BPF_TRACE_UPROBE_MULTI)
4457 return -EINVAL;
4458 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4459 attach_type != BPF_TRACE_UPROBE_SESSION)
4460 return -EINVAL;
4461 if (attach_type != BPF_PERF_EVENT &&
4462 attach_type != BPF_TRACE_KPROBE_MULTI &&
4463 attach_type != BPF_TRACE_KPROBE_SESSION &&
4464 attach_type != BPF_TRACE_UPROBE_MULTI &&
4465 attach_type != BPF_TRACE_UPROBE_SESSION)
4466 return -EINVAL;
4467 return 0;
4468 case BPF_PROG_TYPE_SCHED_CLS:
4469 if (attach_type != BPF_TCX_INGRESS &&
4470 attach_type != BPF_TCX_EGRESS &&
4471 attach_type != BPF_NETKIT_PRIMARY &&
4472 attach_type != BPF_NETKIT_PEER)
4473 return -EINVAL;
4474 return 0;
4475 default:
4476 ptype = attach_type_to_prog_type(attach_type);
4477 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4478 return -EINVAL;
4479 return 0;
4480 }
4481 }
4482
is_cgroup_prog_type(enum bpf_prog_type ptype,enum bpf_attach_type atype,bool check_atype)4483 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype,
4484 bool check_atype)
4485 {
4486 switch (ptype) {
4487 case BPF_PROG_TYPE_CGROUP_DEVICE:
4488 case BPF_PROG_TYPE_CGROUP_SKB:
4489 case BPF_PROG_TYPE_CGROUP_SOCK:
4490 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4491 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4492 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4493 case BPF_PROG_TYPE_SOCK_OPS:
4494 return true;
4495 case BPF_PROG_TYPE_LSM:
4496 return check_atype ? atype == BPF_LSM_CGROUP : true;
4497 default:
4498 return false;
4499 }
4500 }
4501
4502 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4503
4504 #define BPF_F_ATTACH_MASK_BASE \
4505 (BPF_F_ALLOW_OVERRIDE | \
4506 BPF_F_ALLOW_MULTI | \
4507 BPF_F_REPLACE | \
4508 BPF_F_PREORDER)
4509
4510 #define BPF_F_ATTACH_MASK_MPROG \
4511 (BPF_F_REPLACE | \
4512 BPF_F_BEFORE | \
4513 BPF_F_AFTER | \
4514 BPF_F_ID | \
4515 BPF_F_LINK)
4516
bpf_prog_attach(const union bpf_attr * attr)4517 static int bpf_prog_attach(const union bpf_attr *attr)
4518 {
4519 enum bpf_prog_type ptype;
4520 struct bpf_prog *prog;
4521 int ret;
4522
4523 if (CHECK_ATTR(BPF_PROG_ATTACH))
4524 return -EINVAL;
4525
4526 ptype = attach_type_to_prog_type(attr->attach_type);
4527 if (ptype == BPF_PROG_TYPE_UNSPEC)
4528 return -EINVAL;
4529 if (bpf_mprog_supported(ptype)) {
4530 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4531 return -EINVAL;
4532 } else if (is_cgroup_prog_type(ptype, 0, false)) {
4533 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG))
4534 return -EINVAL;
4535 } else {
4536 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4537 return -EINVAL;
4538 if (attr->relative_fd ||
4539 attr->expected_revision)
4540 return -EINVAL;
4541 }
4542
4543 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4544 if (IS_ERR(prog))
4545 return PTR_ERR(prog);
4546
4547 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4548 bpf_prog_put(prog);
4549 return -EINVAL;
4550 }
4551
4552 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) {
4553 ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4554 goto out;
4555 }
4556
4557 switch (ptype) {
4558 case BPF_PROG_TYPE_SK_SKB:
4559 case BPF_PROG_TYPE_SK_MSG:
4560 ret = sock_map_get_from_fd(attr, prog);
4561 break;
4562 case BPF_PROG_TYPE_LIRC_MODE2:
4563 ret = lirc_prog_attach(attr, prog);
4564 break;
4565 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4566 ret = netns_bpf_prog_attach(attr, prog);
4567 break;
4568 case BPF_PROG_TYPE_SCHED_CLS:
4569 if (attr->attach_type == BPF_TCX_INGRESS ||
4570 attr->attach_type == BPF_TCX_EGRESS)
4571 ret = tcx_prog_attach(attr, prog);
4572 else
4573 ret = netkit_prog_attach(attr, prog);
4574 break;
4575 default:
4576 ret = -EINVAL;
4577 }
4578 out:
4579 if (ret)
4580 bpf_prog_put(prog);
4581 return ret;
4582 }
4583
4584 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4585
bpf_prog_detach(const union bpf_attr * attr)4586 static int bpf_prog_detach(const union bpf_attr *attr)
4587 {
4588 struct bpf_prog *prog = NULL;
4589 enum bpf_prog_type ptype;
4590 int ret;
4591
4592 if (CHECK_ATTR(BPF_PROG_DETACH))
4593 return -EINVAL;
4594
4595 ptype = attach_type_to_prog_type(attr->attach_type);
4596 if (bpf_mprog_supported(ptype)) {
4597 if (ptype == BPF_PROG_TYPE_UNSPEC)
4598 return -EINVAL;
4599 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4600 return -EINVAL;
4601 if (attr->attach_bpf_fd) {
4602 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4603 if (IS_ERR(prog))
4604 return PTR_ERR(prog);
4605 } else if (!bpf_mprog_detach_empty(ptype)) {
4606 return -EPERM;
4607 }
4608 } else if (is_cgroup_prog_type(ptype, 0, false)) {
4609 if (attr->attach_flags || attr->relative_fd)
4610 return -EINVAL;
4611 } else if (attr->attach_flags ||
4612 attr->relative_fd ||
4613 attr->expected_revision) {
4614 return -EINVAL;
4615 }
4616
4617 switch (ptype) {
4618 case BPF_PROG_TYPE_SK_MSG:
4619 case BPF_PROG_TYPE_SK_SKB:
4620 ret = sock_map_prog_detach(attr, ptype);
4621 break;
4622 case BPF_PROG_TYPE_LIRC_MODE2:
4623 ret = lirc_prog_detach(attr);
4624 break;
4625 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4626 ret = netns_bpf_prog_detach(attr, ptype);
4627 break;
4628 case BPF_PROG_TYPE_CGROUP_DEVICE:
4629 case BPF_PROG_TYPE_CGROUP_SKB:
4630 case BPF_PROG_TYPE_CGROUP_SOCK:
4631 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4632 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4633 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4634 case BPF_PROG_TYPE_SOCK_OPS:
4635 case BPF_PROG_TYPE_LSM:
4636 ret = cgroup_bpf_prog_detach(attr, ptype);
4637 break;
4638 case BPF_PROG_TYPE_SCHED_CLS:
4639 if (attr->attach_type == BPF_TCX_INGRESS ||
4640 attr->attach_type == BPF_TCX_EGRESS)
4641 ret = tcx_prog_detach(attr, prog);
4642 else
4643 ret = netkit_prog_detach(attr, prog);
4644 break;
4645 default:
4646 ret = -EINVAL;
4647 }
4648
4649 if (prog)
4650 bpf_prog_put(prog);
4651 return ret;
4652 }
4653
4654 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4655
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4656 static int bpf_prog_query(const union bpf_attr *attr,
4657 union bpf_attr __user *uattr)
4658 {
4659 if (!bpf_net_capable())
4660 return -EPERM;
4661 if (CHECK_ATTR(BPF_PROG_QUERY))
4662 return -EINVAL;
4663 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4664 return -EINVAL;
4665
4666 switch (attr->query.attach_type) {
4667 case BPF_CGROUP_INET_INGRESS:
4668 case BPF_CGROUP_INET_EGRESS:
4669 case BPF_CGROUP_INET_SOCK_CREATE:
4670 case BPF_CGROUP_INET_SOCK_RELEASE:
4671 case BPF_CGROUP_INET4_BIND:
4672 case BPF_CGROUP_INET6_BIND:
4673 case BPF_CGROUP_INET4_POST_BIND:
4674 case BPF_CGROUP_INET6_POST_BIND:
4675 case BPF_CGROUP_INET4_CONNECT:
4676 case BPF_CGROUP_INET6_CONNECT:
4677 case BPF_CGROUP_UNIX_CONNECT:
4678 case BPF_CGROUP_INET4_GETPEERNAME:
4679 case BPF_CGROUP_INET6_GETPEERNAME:
4680 case BPF_CGROUP_UNIX_GETPEERNAME:
4681 case BPF_CGROUP_INET4_GETSOCKNAME:
4682 case BPF_CGROUP_INET6_GETSOCKNAME:
4683 case BPF_CGROUP_UNIX_GETSOCKNAME:
4684 case BPF_CGROUP_UDP4_SENDMSG:
4685 case BPF_CGROUP_UDP6_SENDMSG:
4686 case BPF_CGROUP_UNIX_SENDMSG:
4687 case BPF_CGROUP_UDP4_RECVMSG:
4688 case BPF_CGROUP_UDP6_RECVMSG:
4689 case BPF_CGROUP_UNIX_RECVMSG:
4690 case BPF_CGROUP_SOCK_OPS:
4691 case BPF_CGROUP_DEVICE:
4692 case BPF_CGROUP_SYSCTL:
4693 case BPF_CGROUP_GETSOCKOPT:
4694 case BPF_CGROUP_SETSOCKOPT:
4695 case BPF_LSM_CGROUP:
4696 return cgroup_bpf_prog_query(attr, uattr);
4697 case BPF_LIRC_MODE2:
4698 return lirc_prog_query(attr, uattr);
4699 case BPF_FLOW_DISSECTOR:
4700 case BPF_SK_LOOKUP:
4701 return netns_bpf_prog_query(attr, uattr);
4702 case BPF_SK_SKB_STREAM_PARSER:
4703 case BPF_SK_SKB_STREAM_VERDICT:
4704 case BPF_SK_MSG_VERDICT:
4705 case BPF_SK_SKB_VERDICT:
4706 return sock_map_bpf_prog_query(attr, uattr);
4707 case BPF_TCX_INGRESS:
4708 case BPF_TCX_EGRESS:
4709 return tcx_prog_query(attr, uattr);
4710 case BPF_NETKIT_PRIMARY:
4711 case BPF_NETKIT_PEER:
4712 return netkit_prog_query(attr, uattr);
4713 default:
4714 return -EINVAL;
4715 }
4716 }
4717
4718 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4719
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4720 static int bpf_prog_test_run(const union bpf_attr *attr,
4721 union bpf_attr __user *uattr)
4722 {
4723 struct bpf_prog *prog;
4724 int ret = -ENOTSUPP;
4725
4726 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4727 return -EINVAL;
4728
4729 if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4730 (!attr->test.ctx_size_in && attr->test.ctx_in))
4731 return -EINVAL;
4732
4733 if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4734 (!attr->test.ctx_size_out && attr->test.ctx_out))
4735 return -EINVAL;
4736
4737 prog = bpf_prog_get(attr->test.prog_fd);
4738 if (IS_ERR(prog))
4739 return PTR_ERR(prog);
4740
4741 if (prog->aux->ops->test_run)
4742 ret = prog->aux->ops->test_run(prog, attr, uattr);
4743
4744 bpf_prog_put(prog);
4745 return ret;
4746 }
4747
4748 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4749
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4750 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4751 union bpf_attr __user *uattr,
4752 struct idr *idr,
4753 spinlock_t *lock)
4754 {
4755 u32 next_id = attr->start_id;
4756 int err = 0;
4757
4758 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4759 return -EINVAL;
4760
4761 if (!capable(CAP_SYS_ADMIN))
4762 return -EPERM;
4763
4764 next_id++;
4765 spin_lock_bh(lock);
4766 if (!idr_get_next(idr, &next_id))
4767 err = -ENOENT;
4768 spin_unlock_bh(lock);
4769
4770 if (!err)
4771 err = put_user(next_id, &uattr->next_id);
4772
4773 return err;
4774 }
4775
bpf_map_get_curr_or_next(u32 * id)4776 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4777 {
4778 struct bpf_map *map;
4779
4780 spin_lock_bh(&map_idr_lock);
4781 again:
4782 map = idr_get_next(&map_idr, id);
4783 if (map) {
4784 map = __bpf_map_inc_not_zero(map, false);
4785 if (IS_ERR(map)) {
4786 (*id)++;
4787 goto again;
4788 }
4789 }
4790 spin_unlock_bh(&map_idr_lock);
4791
4792 return map;
4793 }
4794
bpf_prog_get_curr_or_next(u32 * id)4795 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4796 {
4797 struct bpf_prog *prog;
4798
4799 spin_lock_bh(&prog_idr_lock);
4800 again:
4801 prog = idr_get_next(&prog_idr, id);
4802 if (prog) {
4803 prog = bpf_prog_inc_not_zero(prog);
4804 if (IS_ERR(prog)) {
4805 (*id)++;
4806 goto again;
4807 }
4808 }
4809 spin_unlock_bh(&prog_idr_lock);
4810
4811 return prog;
4812 }
4813
4814 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4815
bpf_prog_by_id(u32 id)4816 struct bpf_prog *bpf_prog_by_id(u32 id)
4817 {
4818 struct bpf_prog *prog;
4819
4820 if (!id)
4821 return ERR_PTR(-ENOENT);
4822
4823 spin_lock_bh(&prog_idr_lock);
4824 prog = idr_find(&prog_idr, id);
4825 if (prog)
4826 prog = bpf_prog_inc_not_zero(prog);
4827 else
4828 prog = ERR_PTR(-ENOENT);
4829 spin_unlock_bh(&prog_idr_lock);
4830 return prog;
4831 }
4832
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4833 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4834 {
4835 struct bpf_prog *prog;
4836 u32 id = attr->prog_id;
4837 int fd;
4838
4839 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4840 return -EINVAL;
4841
4842 if (!capable(CAP_SYS_ADMIN))
4843 return -EPERM;
4844
4845 prog = bpf_prog_by_id(id);
4846 if (IS_ERR(prog))
4847 return PTR_ERR(prog);
4848
4849 fd = bpf_prog_new_fd(prog);
4850 if (fd < 0)
4851 bpf_prog_put(prog);
4852
4853 return fd;
4854 }
4855
4856 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4857
bpf_map_get_fd_by_id(const union bpf_attr * attr)4858 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4859 {
4860 struct bpf_map *map;
4861 u32 id = attr->map_id;
4862 int f_flags;
4863 int fd;
4864
4865 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4866 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4867 return -EINVAL;
4868
4869 if (!capable(CAP_SYS_ADMIN))
4870 return -EPERM;
4871
4872 f_flags = bpf_get_file_flag(attr->open_flags);
4873 if (f_flags < 0)
4874 return f_flags;
4875
4876 spin_lock_bh(&map_idr_lock);
4877 map = idr_find(&map_idr, id);
4878 if (map)
4879 map = __bpf_map_inc_not_zero(map, true);
4880 else
4881 map = ERR_PTR(-ENOENT);
4882 spin_unlock_bh(&map_idr_lock);
4883
4884 if (IS_ERR(map))
4885 return PTR_ERR(map);
4886
4887 fd = bpf_map_new_fd(map, f_flags);
4888 if (fd < 0)
4889 bpf_map_put_with_uref(map);
4890
4891 return fd;
4892 }
4893
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4894 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4895 unsigned long addr, u32 *off,
4896 u32 *type)
4897 {
4898 const struct bpf_map *map;
4899 int i;
4900
4901 mutex_lock(&prog->aux->used_maps_mutex);
4902 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4903 map = prog->aux->used_maps[i];
4904 if (map == (void *)addr) {
4905 *type = BPF_PSEUDO_MAP_FD;
4906 goto out;
4907 }
4908 if (!map->ops->map_direct_value_meta)
4909 continue;
4910 if (!map->ops->map_direct_value_meta(map, addr, off)) {
4911 *type = BPF_PSEUDO_MAP_VALUE;
4912 goto out;
4913 }
4914 }
4915 map = NULL;
4916
4917 out:
4918 mutex_unlock(&prog->aux->used_maps_mutex);
4919 return map;
4920 }
4921
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4922 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4923 const struct cred *f_cred)
4924 {
4925 const struct bpf_map *map;
4926 struct bpf_insn *insns;
4927 u32 off, type;
4928 u64 imm;
4929 u8 code;
4930 int i;
4931
4932 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4933 GFP_USER);
4934 if (!insns)
4935 return insns;
4936
4937 for (i = 0; i < prog->len; i++) {
4938 code = insns[i].code;
4939
4940 if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4941 insns[i].code = BPF_JMP | BPF_CALL;
4942 insns[i].imm = BPF_FUNC_tail_call;
4943 /* fall-through */
4944 }
4945 if (code == (BPF_JMP | BPF_CALL) ||
4946 code == (BPF_JMP | BPF_CALL_ARGS)) {
4947 if (code == (BPF_JMP | BPF_CALL_ARGS))
4948 insns[i].code = BPF_JMP | BPF_CALL;
4949 if (!bpf_dump_raw_ok(f_cred))
4950 insns[i].imm = 0;
4951 continue;
4952 }
4953 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4954 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4955 continue;
4956 }
4957
4958 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4959 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4960 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4961 continue;
4962 }
4963
4964 if (code != (BPF_LD | BPF_IMM | BPF_DW))
4965 continue;
4966
4967 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4968 map = bpf_map_from_imm(prog, imm, &off, &type);
4969 if (map) {
4970 insns[i].src_reg = type;
4971 insns[i].imm = map->id;
4972 insns[i + 1].imm = off;
4973 continue;
4974 }
4975 }
4976
4977 return insns;
4978 }
4979
set_info_rec_size(struct bpf_prog_info * info)4980 static int set_info_rec_size(struct bpf_prog_info *info)
4981 {
4982 /*
4983 * Ensure info.*_rec_size is the same as kernel expected size
4984 *
4985 * or
4986 *
4987 * Only allow zero *_rec_size if both _rec_size and _cnt are
4988 * zero. In this case, the kernel will set the expected
4989 * _rec_size back to the info.
4990 */
4991
4992 if ((info->nr_func_info || info->func_info_rec_size) &&
4993 info->func_info_rec_size != sizeof(struct bpf_func_info))
4994 return -EINVAL;
4995
4996 if ((info->nr_line_info || info->line_info_rec_size) &&
4997 info->line_info_rec_size != sizeof(struct bpf_line_info))
4998 return -EINVAL;
4999
5000 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
5001 info->jited_line_info_rec_size != sizeof(__u64))
5002 return -EINVAL;
5003
5004 info->func_info_rec_size = sizeof(struct bpf_func_info);
5005 info->line_info_rec_size = sizeof(struct bpf_line_info);
5006 info->jited_line_info_rec_size = sizeof(__u64);
5007
5008 return 0;
5009 }
5010
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)5011 static int bpf_prog_get_info_by_fd(struct file *file,
5012 struct bpf_prog *prog,
5013 const union bpf_attr *attr,
5014 union bpf_attr __user *uattr)
5015 {
5016 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5017 struct btf *attach_btf = bpf_prog_get_target_btf(prog);
5018 struct bpf_prog_info info;
5019 u32 info_len = attr->info.info_len;
5020 struct bpf_prog_kstats stats;
5021 char __user *uinsns;
5022 u32 ulen;
5023 int err;
5024
5025 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5026 if (err)
5027 return err;
5028 info_len = min_t(u32, sizeof(info), info_len);
5029
5030 memset(&info, 0, sizeof(info));
5031 if (copy_from_user(&info, uinfo, info_len))
5032 return -EFAULT;
5033
5034 info.type = prog->type;
5035 info.id = prog->aux->id;
5036 info.load_time = prog->aux->load_time;
5037 info.created_by_uid = from_kuid_munged(current_user_ns(),
5038 prog->aux->user->uid);
5039 info.gpl_compatible = prog->gpl_compatible;
5040
5041 memcpy(info.tag, prog->tag, sizeof(prog->tag));
5042 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
5043
5044 mutex_lock(&prog->aux->used_maps_mutex);
5045 ulen = info.nr_map_ids;
5046 info.nr_map_ids = prog->aux->used_map_cnt;
5047 ulen = min_t(u32, info.nr_map_ids, ulen);
5048 if (ulen) {
5049 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
5050 u32 i;
5051
5052 for (i = 0; i < ulen; i++)
5053 if (put_user(prog->aux->used_maps[i]->id,
5054 &user_map_ids[i])) {
5055 mutex_unlock(&prog->aux->used_maps_mutex);
5056 return -EFAULT;
5057 }
5058 }
5059 mutex_unlock(&prog->aux->used_maps_mutex);
5060
5061 err = set_info_rec_size(&info);
5062 if (err)
5063 return err;
5064
5065 bpf_prog_get_stats(prog, &stats);
5066 info.run_time_ns = stats.nsecs;
5067 info.run_cnt = stats.cnt;
5068 info.recursion_misses = stats.misses;
5069
5070 info.verified_insns = prog->aux->verified_insns;
5071 if (prog->aux->btf)
5072 info.btf_id = btf_obj_id(prog->aux->btf);
5073
5074 if (!bpf_capable()) {
5075 info.jited_prog_len = 0;
5076 info.xlated_prog_len = 0;
5077 info.nr_jited_ksyms = 0;
5078 info.nr_jited_func_lens = 0;
5079 info.nr_func_info = 0;
5080 info.nr_line_info = 0;
5081 info.nr_jited_line_info = 0;
5082 goto done;
5083 }
5084
5085 ulen = info.xlated_prog_len;
5086 info.xlated_prog_len = bpf_prog_insn_size(prog);
5087 if (info.xlated_prog_len && ulen) {
5088 struct bpf_insn *insns_sanitized;
5089 bool fault;
5090
5091 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) {
5092 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
5093 if (!insns_sanitized)
5094 return -ENOMEM;
5095 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
5096 ulen = min_t(u32, info.xlated_prog_len, ulen);
5097 fault = copy_to_user(uinsns, insns_sanitized, ulen);
5098 kfree(insns_sanitized);
5099 if (fault)
5100 return -EFAULT;
5101 } else {
5102 info.xlated_prog_insns = 0;
5103 }
5104 }
5105
5106 if (bpf_prog_is_offloaded(prog->aux)) {
5107 err = bpf_prog_offload_info_fill(&info, prog);
5108 if (err)
5109 return err;
5110 goto done;
5111 }
5112
5113 /* NOTE: the following code is supposed to be skipped for offload.
5114 * bpf_prog_offload_info_fill() is the place to fill similar fields
5115 * for offload.
5116 */
5117 ulen = info.jited_prog_len;
5118 if (prog->aux->func_cnt) {
5119 u32 i;
5120
5121 info.jited_prog_len = 0;
5122 for (i = 0; i < prog->aux->func_cnt; i++)
5123 info.jited_prog_len += prog->aux->func[i]->jited_len;
5124 } else {
5125 info.jited_prog_len = prog->jited_len;
5126 }
5127
5128 if (info.jited_prog_len && ulen) {
5129 if (bpf_dump_raw_ok(file->f_cred)) {
5130 uinsns = u64_to_user_ptr(info.jited_prog_insns);
5131 ulen = min_t(u32, info.jited_prog_len, ulen);
5132
5133 /* for multi-function programs, copy the JITed
5134 * instructions for all the functions
5135 */
5136 if (prog->aux->func_cnt) {
5137 u32 len, free, i;
5138 u8 *img;
5139
5140 free = ulen;
5141 for (i = 0; i < prog->aux->func_cnt; i++) {
5142 len = prog->aux->func[i]->jited_len;
5143 len = min_t(u32, len, free);
5144 img = (u8 *) prog->aux->func[i]->bpf_func;
5145 if (copy_to_user(uinsns, img, len))
5146 return -EFAULT;
5147 uinsns += len;
5148 free -= len;
5149 if (!free)
5150 break;
5151 }
5152 } else {
5153 if (copy_to_user(uinsns, prog->bpf_func, ulen))
5154 return -EFAULT;
5155 }
5156 } else {
5157 info.jited_prog_insns = 0;
5158 }
5159 }
5160
5161 ulen = info.nr_jited_ksyms;
5162 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
5163 if (ulen) {
5164 if (bpf_dump_raw_ok(file->f_cred)) {
5165 unsigned long ksym_addr;
5166 u64 __user *user_ksyms;
5167 u32 i;
5168
5169 /* copy the address of the kernel symbol
5170 * corresponding to each function
5171 */
5172 ulen = min_t(u32, info.nr_jited_ksyms, ulen);
5173 user_ksyms = u64_to_user_ptr(info.jited_ksyms);
5174 if (prog->aux->func_cnt) {
5175 for (i = 0; i < ulen; i++) {
5176 ksym_addr = (unsigned long)
5177 prog->aux->func[i]->bpf_func;
5178 if (put_user((u64) ksym_addr,
5179 &user_ksyms[i]))
5180 return -EFAULT;
5181 }
5182 } else {
5183 ksym_addr = (unsigned long) prog->bpf_func;
5184 if (put_user((u64) ksym_addr, &user_ksyms[0]))
5185 return -EFAULT;
5186 }
5187 } else {
5188 info.jited_ksyms = 0;
5189 }
5190 }
5191
5192 ulen = info.nr_jited_func_lens;
5193 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
5194 if (ulen) {
5195 if (bpf_dump_raw_ok(file->f_cred)) {
5196 u32 __user *user_lens;
5197 u32 func_len, i;
5198
5199 /* copy the JITed image lengths for each function */
5200 ulen = min_t(u32, info.nr_jited_func_lens, ulen);
5201 user_lens = u64_to_user_ptr(info.jited_func_lens);
5202 if (prog->aux->func_cnt) {
5203 for (i = 0; i < ulen; i++) {
5204 func_len =
5205 prog->aux->func[i]->jited_len;
5206 if (put_user(func_len, &user_lens[i]))
5207 return -EFAULT;
5208 }
5209 } else {
5210 func_len = prog->jited_len;
5211 if (put_user(func_len, &user_lens[0]))
5212 return -EFAULT;
5213 }
5214 } else {
5215 info.jited_func_lens = 0;
5216 }
5217 }
5218
5219 info.attach_btf_id = prog->aux->attach_btf_id;
5220 if (attach_btf)
5221 info.attach_btf_obj_id = btf_obj_id(attach_btf);
5222
5223 ulen = info.nr_func_info;
5224 info.nr_func_info = prog->aux->func_info_cnt;
5225 if (info.nr_func_info && ulen) {
5226 char __user *user_finfo;
5227
5228 user_finfo = u64_to_user_ptr(info.func_info);
5229 ulen = min_t(u32, info.nr_func_info, ulen);
5230 if (copy_to_user(user_finfo, prog->aux->func_info,
5231 info.func_info_rec_size * ulen))
5232 return -EFAULT;
5233 }
5234
5235 ulen = info.nr_line_info;
5236 info.nr_line_info = prog->aux->nr_linfo;
5237 if (info.nr_line_info && ulen) {
5238 __u8 __user *user_linfo;
5239
5240 user_linfo = u64_to_user_ptr(info.line_info);
5241 ulen = min_t(u32, info.nr_line_info, ulen);
5242 if (copy_to_user(user_linfo, prog->aux->linfo,
5243 info.line_info_rec_size * ulen))
5244 return -EFAULT;
5245 }
5246
5247 ulen = info.nr_jited_line_info;
5248 if (prog->aux->jited_linfo)
5249 info.nr_jited_line_info = prog->aux->nr_linfo;
5250 else
5251 info.nr_jited_line_info = 0;
5252 if (info.nr_jited_line_info && ulen) {
5253 if (bpf_dump_raw_ok(file->f_cred)) {
5254 unsigned long line_addr;
5255 __u64 __user *user_linfo;
5256 u32 i;
5257
5258 user_linfo = u64_to_user_ptr(info.jited_line_info);
5259 ulen = min_t(u32, info.nr_jited_line_info, ulen);
5260 for (i = 0; i < ulen; i++) {
5261 line_addr = (unsigned long)prog->aux->jited_linfo[i];
5262 if (put_user((__u64)line_addr, &user_linfo[i]))
5263 return -EFAULT;
5264 }
5265 } else {
5266 info.jited_line_info = 0;
5267 }
5268 }
5269
5270 ulen = info.nr_prog_tags;
5271 info.nr_prog_tags = prog->aux->func_cnt ? : 1;
5272 if (ulen) {
5273 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
5274 u32 i;
5275
5276 user_prog_tags = u64_to_user_ptr(info.prog_tags);
5277 ulen = min_t(u32, info.nr_prog_tags, ulen);
5278 if (prog->aux->func_cnt) {
5279 for (i = 0; i < ulen; i++) {
5280 if (copy_to_user(user_prog_tags[i],
5281 prog->aux->func[i]->tag,
5282 BPF_TAG_SIZE))
5283 return -EFAULT;
5284 }
5285 } else {
5286 if (copy_to_user(user_prog_tags[0],
5287 prog->tag, BPF_TAG_SIZE))
5288 return -EFAULT;
5289 }
5290 }
5291
5292 done:
5293 if (copy_to_user(uinfo, &info, info_len) ||
5294 put_user(info_len, &uattr->info.info_len))
5295 return -EFAULT;
5296
5297 return 0;
5298 }
5299
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)5300 static int bpf_map_get_info_by_fd(struct file *file,
5301 struct bpf_map *map,
5302 const union bpf_attr *attr,
5303 union bpf_attr __user *uattr)
5304 {
5305 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5306 struct bpf_map_info info;
5307 u32 info_len = attr->info.info_len;
5308 int err;
5309
5310 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5311 if (err)
5312 return err;
5313 info_len = min_t(u32, sizeof(info), info_len);
5314
5315 memset(&info, 0, sizeof(info));
5316 if (copy_from_user(&info, uinfo, info_len))
5317 return -EFAULT;
5318
5319 info.type = map->map_type;
5320 info.id = map->id;
5321 info.key_size = map->key_size;
5322 info.value_size = map->value_size;
5323 info.max_entries = map->max_entries;
5324 info.map_flags = map->map_flags;
5325 info.map_extra = map->map_extra;
5326 memcpy(info.name, map->name, sizeof(map->name));
5327
5328 if (map->btf) {
5329 info.btf_id = btf_obj_id(map->btf);
5330 info.btf_key_type_id = map->btf_key_type_id;
5331 info.btf_value_type_id = map->btf_value_type_id;
5332 }
5333 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5334 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5335 bpf_map_struct_ops_info_fill(&info, map);
5336
5337 if (bpf_map_is_offloaded(map)) {
5338 err = bpf_map_offload_info_fill(&info, map);
5339 if (err)
5340 return err;
5341 }
5342
5343 if (info.hash) {
5344 char __user *uhash = u64_to_user_ptr(info.hash);
5345
5346 if (!map->ops->map_get_hash)
5347 return -EINVAL;
5348
5349 if (info.hash_size != SHA256_DIGEST_SIZE)
5350 return -EINVAL;
5351
5352 if (!READ_ONCE(map->frozen))
5353 return -EPERM;
5354
5355 err = map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, map->sha);
5356 if (err != 0)
5357 return err;
5358
5359 if (copy_to_user(uhash, map->sha, SHA256_DIGEST_SIZE) != 0)
5360 return -EFAULT;
5361 } else if (info.hash_size) {
5362 return -EINVAL;
5363 }
5364
5365 if (copy_to_user(uinfo, &info, info_len) ||
5366 put_user(info_len, &uattr->info.info_len))
5367 return -EFAULT;
5368
5369 return 0;
5370 }
5371
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5372 static int bpf_btf_get_info_by_fd(struct file *file,
5373 struct btf *btf,
5374 const union bpf_attr *attr,
5375 union bpf_attr __user *uattr)
5376 {
5377 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5378 u32 info_len = attr->info.info_len;
5379 int err;
5380
5381 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5382 if (err)
5383 return err;
5384
5385 return btf_get_info_by_fd(btf, attr, uattr);
5386 }
5387
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5388 static int bpf_link_get_info_by_fd(struct file *file,
5389 struct bpf_link *link,
5390 const union bpf_attr *attr,
5391 union bpf_attr __user *uattr)
5392 {
5393 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5394 struct bpf_link_info info;
5395 u32 info_len = attr->info.info_len;
5396 int err;
5397
5398 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5399 if (err)
5400 return err;
5401 info_len = min_t(u32, sizeof(info), info_len);
5402
5403 memset(&info, 0, sizeof(info));
5404 if (copy_from_user(&info, uinfo, info_len))
5405 return -EFAULT;
5406
5407 info.type = link->type;
5408 info.id = link->id;
5409 if (link->prog)
5410 info.prog_id = link->prog->aux->id;
5411
5412 if (link->ops->fill_link_info) {
5413 err = link->ops->fill_link_info(link, &info);
5414 if (err)
5415 return err;
5416 }
5417
5418 if (copy_to_user(uinfo, &info, info_len) ||
5419 put_user(info_len, &uattr->info.info_len))
5420 return -EFAULT;
5421
5422 return 0;
5423 }
5424
5425
token_get_info_by_fd(struct file * file,struct bpf_token * token,const union bpf_attr * attr,union bpf_attr __user * uattr)5426 static int token_get_info_by_fd(struct file *file,
5427 struct bpf_token *token,
5428 const union bpf_attr *attr,
5429 union bpf_attr __user *uattr)
5430 {
5431 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5432 u32 info_len = attr->info.info_len;
5433 int err;
5434
5435 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5436 if (err)
5437 return err;
5438 return bpf_token_get_info_by_fd(token, attr, uattr);
5439 }
5440
5441 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5442
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5443 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5444 union bpf_attr __user *uattr)
5445 {
5446 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5447 return -EINVAL;
5448
5449 CLASS(fd, f)(attr->info.bpf_fd);
5450 if (fd_empty(f))
5451 return -EBADFD;
5452
5453 if (fd_file(f)->f_op == &bpf_prog_fops)
5454 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5455 uattr);
5456 else if (fd_file(f)->f_op == &bpf_map_fops)
5457 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5458 uattr);
5459 else if (fd_file(f)->f_op == &btf_fops)
5460 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5461 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5462 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5463 attr, uattr);
5464 else if (fd_file(f)->f_op == &bpf_token_fops)
5465 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5466 attr, uattr);
5467 return -EINVAL;
5468 }
5469
5470 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5471
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5472 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5473 {
5474 struct bpf_token *token = NULL;
5475
5476 if (CHECK_ATTR(BPF_BTF_LOAD))
5477 return -EINVAL;
5478
5479 if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5480 return -EINVAL;
5481
5482 if (attr->btf_flags & BPF_F_TOKEN_FD) {
5483 token = bpf_token_get_from_fd(attr->btf_token_fd);
5484 if (IS_ERR(token))
5485 return PTR_ERR(token);
5486 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5487 bpf_token_put(token);
5488 token = NULL;
5489 }
5490 }
5491
5492 if (!bpf_token_capable(token, CAP_BPF)) {
5493 bpf_token_put(token);
5494 return -EPERM;
5495 }
5496
5497 bpf_token_put(token);
5498
5499 return btf_new_fd(attr, uattr, uattr_size);
5500 }
5501
5502 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5503
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5504 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5505 {
5506 struct bpf_token *token = NULL;
5507
5508 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5509 return -EINVAL;
5510
5511 if (attr->open_flags & ~BPF_F_TOKEN_FD)
5512 return -EINVAL;
5513
5514 if (attr->open_flags & BPF_F_TOKEN_FD) {
5515 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5516 if (IS_ERR(token))
5517 return PTR_ERR(token);
5518 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5519 bpf_token_put(token);
5520 token = NULL;
5521 }
5522 }
5523
5524 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5525 bpf_token_put(token);
5526 return -EPERM;
5527 }
5528
5529 bpf_token_put(token);
5530
5531 return btf_get_fd_by_id(attr->btf_id);
5532 }
5533
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)5534 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5535 union bpf_attr __user *uattr,
5536 u32 prog_id, u32 fd_type,
5537 const char *buf, u64 probe_offset,
5538 u64 probe_addr)
5539 {
5540 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5541 u32 len = buf ? strlen(buf) : 0, input_len;
5542 int err = 0;
5543
5544 if (put_user(len, &uattr->task_fd_query.buf_len))
5545 return -EFAULT;
5546 input_len = attr->task_fd_query.buf_len;
5547 if (input_len && ubuf) {
5548 if (!len) {
5549 /* nothing to copy, just make ubuf NULL terminated */
5550 char zero = '\0';
5551
5552 if (put_user(zero, ubuf))
5553 return -EFAULT;
5554 } else {
5555 err = bpf_copy_to_user(ubuf, buf, input_len, len);
5556 if (err == -EFAULT)
5557 return err;
5558 }
5559 }
5560
5561 if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5562 put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5563 put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5564 put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5565 return -EFAULT;
5566
5567 return err;
5568 }
5569
5570 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5571
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5572 static int bpf_task_fd_query(const union bpf_attr *attr,
5573 union bpf_attr __user *uattr)
5574 {
5575 pid_t pid = attr->task_fd_query.pid;
5576 u32 fd = attr->task_fd_query.fd;
5577 const struct perf_event *event;
5578 struct task_struct *task;
5579 struct file *file;
5580 int err;
5581
5582 if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5583 return -EINVAL;
5584
5585 if (!capable(CAP_SYS_ADMIN))
5586 return -EPERM;
5587
5588 if (attr->task_fd_query.flags != 0)
5589 return -EINVAL;
5590
5591 rcu_read_lock();
5592 task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5593 rcu_read_unlock();
5594 if (!task)
5595 return -ENOENT;
5596
5597 err = 0;
5598 file = fget_task(task, fd);
5599 put_task_struct(task);
5600 if (!file)
5601 return -EBADF;
5602
5603 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5604 struct bpf_link *link = file->private_data;
5605
5606 if (link->ops == &bpf_raw_tp_link_lops) {
5607 struct bpf_raw_tp_link *raw_tp =
5608 container_of(link, struct bpf_raw_tp_link, link);
5609 struct bpf_raw_event_map *btp = raw_tp->btp;
5610
5611 err = bpf_task_fd_query_copy(attr, uattr,
5612 raw_tp->link.prog->aux->id,
5613 BPF_FD_TYPE_RAW_TRACEPOINT,
5614 btp->tp->name, 0, 0);
5615 goto put_file;
5616 }
5617 goto out_not_supp;
5618 }
5619
5620 event = perf_get_event(file);
5621 if (!IS_ERR(event)) {
5622 u64 probe_offset, probe_addr;
5623 u32 prog_id, fd_type;
5624 const char *buf;
5625
5626 err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5627 &buf, &probe_offset,
5628 &probe_addr, NULL);
5629 if (!err)
5630 err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5631 fd_type, buf,
5632 probe_offset,
5633 probe_addr);
5634 goto put_file;
5635 }
5636
5637 out_not_supp:
5638 err = -ENOTSUPP;
5639 put_file:
5640 fput(file);
5641 return err;
5642 }
5643
5644 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5645
5646 #define BPF_DO_BATCH(fn, ...) \
5647 do { \
5648 if (!fn) { \
5649 err = -ENOTSUPP; \
5650 goto err_put; \
5651 } \
5652 err = fn(__VA_ARGS__); \
5653 } while (0)
5654
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5655 static int bpf_map_do_batch(const union bpf_attr *attr,
5656 union bpf_attr __user *uattr,
5657 int cmd)
5658 {
5659 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH ||
5660 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5661 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5662 struct bpf_map *map;
5663 int err;
5664
5665 if (CHECK_ATTR(BPF_MAP_BATCH))
5666 return -EINVAL;
5667
5668 CLASS(fd, f)(attr->batch.map_fd);
5669
5670 map = __bpf_map_get(f);
5671 if (IS_ERR(map))
5672 return PTR_ERR(map);
5673 if (has_write)
5674 bpf_map_write_active_inc(map);
5675 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5676 err = -EPERM;
5677 goto err_put;
5678 }
5679 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5680 err = -EPERM;
5681 goto err_put;
5682 }
5683
5684 if (cmd == BPF_MAP_LOOKUP_BATCH)
5685 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5686 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5687 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5688 else if (cmd == BPF_MAP_UPDATE_BATCH)
5689 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5690 else
5691 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5692 err_put:
5693 if (has_write) {
5694 maybe_wait_bpf_programs(map);
5695 bpf_map_write_active_dec(map);
5696 }
5697 return err;
5698 }
5699
5700 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5701 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5702 {
5703 struct bpf_prog *prog;
5704 int ret;
5705
5706 if (CHECK_ATTR(BPF_LINK_CREATE))
5707 return -EINVAL;
5708
5709 if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5710 return bpf_struct_ops_link_create(attr);
5711
5712 prog = bpf_prog_get(attr->link_create.prog_fd);
5713 if (IS_ERR(prog))
5714 return PTR_ERR(prog);
5715
5716 ret = bpf_prog_attach_check_attach_type(prog,
5717 attr->link_create.attach_type);
5718 if (ret)
5719 goto out;
5720
5721 switch (prog->type) {
5722 case BPF_PROG_TYPE_CGROUP_SKB:
5723 case BPF_PROG_TYPE_CGROUP_SOCK:
5724 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5725 case BPF_PROG_TYPE_SOCK_OPS:
5726 case BPF_PROG_TYPE_CGROUP_DEVICE:
5727 case BPF_PROG_TYPE_CGROUP_SYSCTL:
5728 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5729 ret = cgroup_bpf_link_attach(attr, prog);
5730 break;
5731 case BPF_PROG_TYPE_EXT:
5732 ret = bpf_tracing_prog_attach(prog,
5733 attr->link_create.target_fd,
5734 attr->link_create.target_btf_id,
5735 attr->link_create.tracing.cookie,
5736 attr->link_create.attach_type);
5737 break;
5738 case BPF_PROG_TYPE_LSM:
5739 case BPF_PROG_TYPE_TRACING:
5740 if (attr->link_create.attach_type != prog->expected_attach_type) {
5741 ret = -EINVAL;
5742 goto out;
5743 }
5744 if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5745 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie,
5746 attr->link_create.attach_type);
5747 else if (prog->expected_attach_type == BPF_TRACE_ITER)
5748 ret = bpf_iter_link_attach(attr, uattr, prog);
5749 else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5750 ret = cgroup_bpf_link_attach(attr, prog);
5751 else
5752 ret = bpf_tracing_prog_attach(prog,
5753 attr->link_create.target_fd,
5754 attr->link_create.target_btf_id,
5755 attr->link_create.tracing.cookie,
5756 attr->link_create.attach_type);
5757 break;
5758 case BPF_PROG_TYPE_FLOW_DISSECTOR:
5759 case BPF_PROG_TYPE_SK_LOOKUP:
5760 ret = netns_bpf_link_create(attr, prog);
5761 break;
5762 case BPF_PROG_TYPE_SK_MSG:
5763 case BPF_PROG_TYPE_SK_SKB:
5764 ret = sock_map_link_create(attr, prog);
5765 break;
5766 #ifdef CONFIG_NET
5767 case BPF_PROG_TYPE_XDP:
5768 ret = bpf_xdp_link_attach(attr, prog);
5769 break;
5770 case BPF_PROG_TYPE_SCHED_CLS:
5771 if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5772 attr->link_create.attach_type == BPF_TCX_EGRESS)
5773 ret = tcx_link_attach(attr, prog);
5774 else
5775 ret = netkit_link_attach(attr, prog);
5776 break;
5777 case BPF_PROG_TYPE_NETFILTER:
5778 ret = bpf_nf_link_attach(attr, prog);
5779 break;
5780 #endif
5781 case BPF_PROG_TYPE_PERF_EVENT:
5782 case BPF_PROG_TYPE_TRACEPOINT:
5783 ret = bpf_perf_link_attach(attr, prog);
5784 break;
5785 case BPF_PROG_TYPE_KPROBE:
5786 if (attr->link_create.attach_type == BPF_PERF_EVENT)
5787 ret = bpf_perf_link_attach(attr, prog);
5788 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5789 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5790 ret = bpf_kprobe_multi_link_attach(attr, prog);
5791 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5792 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5793 ret = bpf_uprobe_multi_link_attach(attr, prog);
5794 break;
5795 default:
5796 ret = -EINVAL;
5797 }
5798
5799 out:
5800 if (ret < 0)
5801 bpf_prog_put(prog);
5802 return ret;
5803 }
5804
link_update_map(struct bpf_link * link,union bpf_attr * attr)5805 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5806 {
5807 struct bpf_map *new_map, *old_map = NULL;
5808 int ret;
5809
5810 new_map = bpf_map_get(attr->link_update.new_map_fd);
5811 if (IS_ERR(new_map))
5812 return PTR_ERR(new_map);
5813
5814 if (attr->link_update.flags & BPF_F_REPLACE) {
5815 old_map = bpf_map_get(attr->link_update.old_map_fd);
5816 if (IS_ERR(old_map)) {
5817 ret = PTR_ERR(old_map);
5818 goto out_put;
5819 }
5820 } else if (attr->link_update.old_map_fd) {
5821 ret = -EINVAL;
5822 goto out_put;
5823 }
5824
5825 ret = link->ops->update_map(link, new_map, old_map);
5826
5827 if (old_map)
5828 bpf_map_put(old_map);
5829 out_put:
5830 bpf_map_put(new_map);
5831 return ret;
5832 }
5833
5834 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5835
link_update(union bpf_attr * attr)5836 static int link_update(union bpf_attr *attr)
5837 {
5838 struct bpf_prog *old_prog = NULL, *new_prog;
5839 struct bpf_link *link;
5840 u32 flags;
5841 int ret;
5842
5843 if (CHECK_ATTR(BPF_LINK_UPDATE))
5844 return -EINVAL;
5845
5846 flags = attr->link_update.flags;
5847 if (flags & ~BPF_F_REPLACE)
5848 return -EINVAL;
5849
5850 link = bpf_link_get_from_fd(attr->link_update.link_fd);
5851 if (IS_ERR(link))
5852 return PTR_ERR(link);
5853
5854 if (link->ops->update_map) {
5855 ret = link_update_map(link, attr);
5856 goto out_put_link;
5857 }
5858
5859 new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5860 if (IS_ERR(new_prog)) {
5861 ret = PTR_ERR(new_prog);
5862 goto out_put_link;
5863 }
5864
5865 if (flags & BPF_F_REPLACE) {
5866 old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5867 if (IS_ERR(old_prog)) {
5868 ret = PTR_ERR(old_prog);
5869 old_prog = NULL;
5870 goto out_put_progs;
5871 }
5872 } else if (attr->link_update.old_prog_fd) {
5873 ret = -EINVAL;
5874 goto out_put_progs;
5875 }
5876
5877 if (link->ops->update_prog)
5878 ret = link->ops->update_prog(link, new_prog, old_prog);
5879 else
5880 ret = -EINVAL;
5881
5882 out_put_progs:
5883 if (old_prog)
5884 bpf_prog_put(old_prog);
5885 if (ret)
5886 bpf_prog_put(new_prog);
5887 out_put_link:
5888 bpf_link_put_direct(link);
5889 return ret;
5890 }
5891
5892 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5893
link_detach(union bpf_attr * attr)5894 static int link_detach(union bpf_attr *attr)
5895 {
5896 struct bpf_link *link;
5897 int ret;
5898
5899 if (CHECK_ATTR(BPF_LINK_DETACH))
5900 return -EINVAL;
5901
5902 link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5903 if (IS_ERR(link))
5904 return PTR_ERR(link);
5905
5906 if (link->ops->detach)
5907 ret = link->ops->detach(link);
5908 else
5909 ret = -EOPNOTSUPP;
5910
5911 bpf_link_put_direct(link);
5912 return ret;
5913 }
5914
bpf_link_inc_not_zero(struct bpf_link * link)5915 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5916 {
5917 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5918 }
5919 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5920
bpf_link_by_id(u32 id)5921 struct bpf_link *bpf_link_by_id(u32 id)
5922 {
5923 struct bpf_link *link;
5924
5925 if (!id)
5926 return ERR_PTR(-ENOENT);
5927
5928 spin_lock_bh(&link_idr_lock);
5929 /* before link is "settled", ID is 0, pretend it doesn't exist yet */
5930 link = idr_find(&link_idr, id);
5931 if (link) {
5932 if (link->id)
5933 link = bpf_link_inc_not_zero(link);
5934 else
5935 link = ERR_PTR(-EAGAIN);
5936 } else {
5937 link = ERR_PTR(-ENOENT);
5938 }
5939 spin_unlock_bh(&link_idr_lock);
5940 return link;
5941 }
5942
bpf_link_get_curr_or_next(u32 * id)5943 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5944 {
5945 struct bpf_link *link;
5946
5947 spin_lock_bh(&link_idr_lock);
5948 again:
5949 link = idr_get_next(&link_idr, id);
5950 if (link) {
5951 link = bpf_link_inc_not_zero(link);
5952 if (IS_ERR(link)) {
5953 (*id)++;
5954 goto again;
5955 }
5956 }
5957 spin_unlock_bh(&link_idr_lock);
5958
5959 return link;
5960 }
5961
5962 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5963
bpf_link_get_fd_by_id(const union bpf_attr * attr)5964 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5965 {
5966 struct bpf_link *link;
5967 u32 id = attr->link_id;
5968 int fd;
5969
5970 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5971 return -EINVAL;
5972
5973 if (!capable(CAP_SYS_ADMIN))
5974 return -EPERM;
5975
5976 link = bpf_link_by_id(id);
5977 if (IS_ERR(link))
5978 return PTR_ERR(link);
5979
5980 fd = bpf_link_new_fd(link);
5981 if (fd < 0)
5982 bpf_link_put_direct(link);
5983
5984 return fd;
5985 }
5986
5987 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5988
bpf_stats_release(struct inode * inode,struct file * file)5989 static int bpf_stats_release(struct inode *inode, struct file *file)
5990 {
5991 mutex_lock(&bpf_stats_enabled_mutex);
5992 static_key_slow_dec(&bpf_stats_enabled_key.key);
5993 mutex_unlock(&bpf_stats_enabled_mutex);
5994 return 0;
5995 }
5996
5997 static const struct file_operations bpf_stats_fops = {
5998 .release = bpf_stats_release,
5999 };
6000
bpf_enable_runtime_stats(void)6001 static int bpf_enable_runtime_stats(void)
6002 {
6003 int fd;
6004
6005 mutex_lock(&bpf_stats_enabled_mutex);
6006
6007 /* Set a very high limit to avoid overflow */
6008 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
6009 mutex_unlock(&bpf_stats_enabled_mutex);
6010 return -EBUSY;
6011 }
6012
6013 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
6014 if (fd >= 0)
6015 static_key_slow_inc(&bpf_stats_enabled_key.key);
6016
6017 mutex_unlock(&bpf_stats_enabled_mutex);
6018 return fd;
6019 }
6020
6021 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
6022
bpf_enable_stats(union bpf_attr * attr)6023 static int bpf_enable_stats(union bpf_attr *attr)
6024 {
6025
6026 if (CHECK_ATTR(BPF_ENABLE_STATS))
6027 return -EINVAL;
6028
6029 if (!capable(CAP_SYS_ADMIN))
6030 return -EPERM;
6031
6032 switch (attr->enable_stats.type) {
6033 case BPF_STATS_RUN_TIME:
6034 return bpf_enable_runtime_stats();
6035 default:
6036 break;
6037 }
6038 return -EINVAL;
6039 }
6040
6041 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
6042
bpf_iter_create(union bpf_attr * attr)6043 static int bpf_iter_create(union bpf_attr *attr)
6044 {
6045 struct bpf_link *link;
6046 int err;
6047
6048 if (CHECK_ATTR(BPF_ITER_CREATE))
6049 return -EINVAL;
6050
6051 if (attr->iter_create.flags)
6052 return -EINVAL;
6053
6054 link = bpf_link_get_from_fd(attr->iter_create.link_fd);
6055 if (IS_ERR(link))
6056 return PTR_ERR(link);
6057
6058 err = bpf_iter_new_fd(link);
6059 bpf_link_put_direct(link);
6060
6061 return err;
6062 }
6063
6064 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
6065
bpf_prog_bind_map(union bpf_attr * attr)6066 static int bpf_prog_bind_map(union bpf_attr *attr)
6067 {
6068 struct bpf_prog *prog;
6069 struct bpf_map *map;
6070 struct bpf_map **used_maps_old, **used_maps_new;
6071 int i, ret = 0;
6072
6073 if (CHECK_ATTR(BPF_PROG_BIND_MAP))
6074 return -EINVAL;
6075
6076 if (attr->prog_bind_map.flags)
6077 return -EINVAL;
6078
6079 prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
6080 if (IS_ERR(prog))
6081 return PTR_ERR(prog);
6082
6083 map = bpf_map_get(attr->prog_bind_map.map_fd);
6084 if (IS_ERR(map)) {
6085 ret = PTR_ERR(map);
6086 goto out_prog_put;
6087 }
6088
6089 mutex_lock(&prog->aux->used_maps_mutex);
6090
6091 used_maps_old = prog->aux->used_maps;
6092
6093 for (i = 0; i < prog->aux->used_map_cnt; i++)
6094 if (used_maps_old[i] == map) {
6095 bpf_map_put(map);
6096 goto out_unlock;
6097 }
6098
6099 used_maps_new = kmalloc_objs(used_maps_new[0],
6100 prog->aux->used_map_cnt + 1);
6101 if (!used_maps_new) {
6102 ret = -ENOMEM;
6103 goto out_unlock;
6104 }
6105
6106 /* The bpf program will not access the bpf map, but for the sake of
6107 * simplicity, increase sleepable_refcnt for sleepable program as well.
6108 */
6109 if (prog->sleepable)
6110 atomic64_inc(&map->sleepable_refcnt);
6111 memcpy(used_maps_new, used_maps_old,
6112 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
6113 used_maps_new[prog->aux->used_map_cnt] = map;
6114
6115 prog->aux->used_map_cnt++;
6116 prog->aux->used_maps = used_maps_new;
6117
6118 kfree(used_maps_old);
6119
6120 out_unlock:
6121 mutex_unlock(&prog->aux->used_maps_mutex);
6122
6123 if (ret)
6124 bpf_map_put(map);
6125 out_prog_put:
6126 bpf_prog_put(prog);
6127 return ret;
6128 }
6129
6130 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
6131
token_create(union bpf_attr * attr)6132 static int token_create(union bpf_attr *attr)
6133 {
6134 if (CHECK_ATTR(BPF_TOKEN_CREATE))
6135 return -EINVAL;
6136
6137 /* no flags are supported yet */
6138 if (attr->token_create.flags)
6139 return -EINVAL;
6140
6141 return bpf_token_create(attr);
6142 }
6143
6144 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd
6145
prog_stream_read(union bpf_attr * attr)6146 static int prog_stream_read(union bpf_attr *attr)
6147 {
6148 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf);
6149 u32 len = attr->prog_stream_read.stream_buf_len;
6150 struct bpf_prog *prog;
6151 int ret;
6152
6153 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD))
6154 return -EINVAL;
6155
6156 prog = bpf_prog_get(attr->prog_stream_read.prog_fd);
6157 if (IS_ERR(prog))
6158 return PTR_ERR(prog);
6159
6160 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len);
6161 bpf_prog_put(prog);
6162
6163 return ret;
6164 }
6165
6166 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.prog_fd
6167
prog_assoc_struct_ops(union bpf_attr * attr)6168 static int prog_assoc_struct_ops(union bpf_attr *attr)
6169 {
6170 struct bpf_prog *prog;
6171 struct bpf_map *map;
6172 int ret;
6173
6174 if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS))
6175 return -EINVAL;
6176
6177 if (attr->prog_assoc_struct_ops.flags)
6178 return -EINVAL;
6179
6180 prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd);
6181 if (IS_ERR(prog))
6182 return PTR_ERR(prog);
6183
6184 if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) {
6185 ret = -EINVAL;
6186 goto put_prog;
6187 }
6188
6189 map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd);
6190 if (IS_ERR(map)) {
6191 ret = PTR_ERR(map);
6192 goto put_prog;
6193 }
6194
6195 if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) {
6196 ret = -EINVAL;
6197 goto put_map;
6198 }
6199
6200 ret = bpf_prog_assoc_struct_ops(prog, map);
6201
6202 put_map:
6203 bpf_map_put(map);
6204 put_prog:
6205 bpf_prog_put(prog);
6206 return ret;
6207 }
6208
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)6209 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
6210 {
6211 union bpf_attr attr;
6212 int err;
6213
6214 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
6215 if (err)
6216 return err;
6217 size = min_t(u32, size, sizeof(attr));
6218
6219 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
6220 memset(&attr, 0, sizeof(attr));
6221 if (copy_from_bpfptr(&attr, uattr, size) != 0)
6222 return -EFAULT;
6223
6224 err = security_bpf(cmd, &attr, size, uattr.is_kernel);
6225 if (err < 0)
6226 return err;
6227
6228 switch (cmd) {
6229 case BPF_MAP_CREATE:
6230 err = map_create(&attr, uattr);
6231 break;
6232 case BPF_MAP_LOOKUP_ELEM:
6233 err = map_lookup_elem(&attr);
6234 break;
6235 case BPF_MAP_UPDATE_ELEM:
6236 err = map_update_elem(&attr, uattr);
6237 break;
6238 case BPF_MAP_DELETE_ELEM:
6239 err = map_delete_elem(&attr, uattr);
6240 break;
6241 case BPF_MAP_GET_NEXT_KEY:
6242 err = map_get_next_key(&attr);
6243 break;
6244 case BPF_MAP_FREEZE:
6245 err = map_freeze(&attr);
6246 break;
6247 case BPF_PROG_LOAD:
6248 err = bpf_prog_load(&attr, uattr, size);
6249 break;
6250 case BPF_OBJ_PIN:
6251 err = bpf_obj_pin(&attr);
6252 break;
6253 case BPF_OBJ_GET:
6254 err = bpf_obj_get(&attr);
6255 break;
6256 case BPF_PROG_ATTACH:
6257 err = bpf_prog_attach(&attr);
6258 break;
6259 case BPF_PROG_DETACH:
6260 err = bpf_prog_detach(&attr);
6261 break;
6262 case BPF_PROG_QUERY:
6263 err = bpf_prog_query(&attr, uattr.user);
6264 break;
6265 case BPF_PROG_TEST_RUN:
6266 err = bpf_prog_test_run(&attr, uattr.user);
6267 break;
6268 case BPF_PROG_GET_NEXT_ID:
6269 err = bpf_obj_get_next_id(&attr, uattr.user,
6270 &prog_idr, &prog_idr_lock);
6271 break;
6272 case BPF_MAP_GET_NEXT_ID:
6273 err = bpf_obj_get_next_id(&attr, uattr.user,
6274 &map_idr, &map_idr_lock);
6275 break;
6276 case BPF_BTF_GET_NEXT_ID:
6277 err = bpf_obj_get_next_id(&attr, uattr.user,
6278 &btf_idr, &btf_idr_lock);
6279 break;
6280 case BPF_PROG_GET_FD_BY_ID:
6281 err = bpf_prog_get_fd_by_id(&attr);
6282 break;
6283 case BPF_MAP_GET_FD_BY_ID:
6284 err = bpf_map_get_fd_by_id(&attr);
6285 break;
6286 case BPF_OBJ_GET_INFO_BY_FD:
6287 err = bpf_obj_get_info_by_fd(&attr, uattr.user);
6288 break;
6289 case BPF_RAW_TRACEPOINT_OPEN:
6290 err = bpf_raw_tracepoint_open(&attr);
6291 break;
6292 case BPF_BTF_LOAD:
6293 err = bpf_btf_load(&attr, uattr, size);
6294 break;
6295 case BPF_BTF_GET_FD_BY_ID:
6296 err = bpf_btf_get_fd_by_id(&attr);
6297 break;
6298 case BPF_TASK_FD_QUERY:
6299 err = bpf_task_fd_query(&attr, uattr.user);
6300 break;
6301 case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
6302 err = map_lookup_and_delete_elem(&attr);
6303 break;
6304 case BPF_MAP_LOOKUP_BATCH:
6305 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
6306 break;
6307 case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
6308 err = bpf_map_do_batch(&attr, uattr.user,
6309 BPF_MAP_LOOKUP_AND_DELETE_BATCH);
6310 break;
6311 case BPF_MAP_UPDATE_BATCH:
6312 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
6313 break;
6314 case BPF_MAP_DELETE_BATCH:
6315 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
6316 break;
6317 case BPF_LINK_CREATE:
6318 err = link_create(&attr, uattr);
6319 break;
6320 case BPF_LINK_UPDATE:
6321 err = link_update(&attr);
6322 break;
6323 case BPF_LINK_GET_FD_BY_ID:
6324 err = bpf_link_get_fd_by_id(&attr);
6325 break;
6326 case BPF_LINK_GET_NEXT_ID:
6327 err = bpf_obj_get_next_id(&attr, uattr.user,
6328 &link_idr, &link_idr_lock);
6329 break;
6330 case BPF_ENABLE_STATS:
6331 err = bpf_enable_stats(&attr);
6332 break;
6333 case BPF_ITER_CREATE:
6334 err = bpf_iter_create(&attr);
6335 break;
6336 case BPF_LINK_DETACH:
6337 err = link_detach(&attr);
6338 break;
6339 case BPF_PROG_BIND_MAP:
6340 err = bpf_prog_bind_map(&attr);
6341 break;
6342 case BPF_TOKEN_CREATE:
6343 err = token_create(&attr);
6344 break;
6345 case BPF_PROG_STREAM_READ_BY_FD:
6346 err = prog_stream_read(&attr);
6347 break;
6348 case BPF_PROG_ASSOC_STRUCT_OPS:
6349 err = prog_assoc_struct_ops(&attr);
6350 break;
6351 default:
6352 err = -EINVAL;
6353 break;
6354 }
6355
6356 return err;
6357 }
6358
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)6359 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
6360 {
6361 return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
6362 }
6363
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)6364 static bool syscall_prog_is_valid_access(int off, int size,
6365 enum bpf_access_type type,
6366 const struct bpf_prog *prog,
6367 struct bpf_insn_access_aux *info)
6368 {
6369 if (off < 0 || off >= U16_MAX)
6370 return false;
6371 /* No alignment requirements for syscall ctx accesses. */
6372 return true;
6373 }
6374
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)6375 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
6376 {
6377 switch (cmd) {
6378 case BPF_MAP_CREATE:
6379 case BPF_MAP_DELETE_ELEM:
6380 case BPF_MAP_UPDATE_ELEM:
6381 case BPF_MAP_FREEZE:
6382 case BPF_MAP_GET_FD_BY_ID:
6383 case BPF_PROG_LOAD:
6384 case BPF_BTF_LOAD:
6385 case BPF_LINK_CREATE:
6386 case BPF_RAW_TRACEPOINT_OPEN:
6387 break;
6388 default:
6389 return -EINVAL;
6390 }
6391 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
6392 }
6393
6394
6395 /* To shut up -Wmissing-prototypes.
6396 * This function is used by the kernel light skeleton
6397 * to load bpf programs when modules are loaded or during kernel boot.
6398 * See tools/lib/bpf/skel_internal.h
6399 */
6400 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
6401
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)6402 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
6403 {
6404 struct bpf_prog * __maybe_unused prog;
6405 struct bpf_tramp_run_ctx __maybe_unused run_ctx;
6406
6407 switch (cmd) {
6408 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
6409 case BPF_PROG_TEST_RUN:
6410 if (attr->test.data_in || attr->test.data_out ||
6411 attr->test.ctx_out || attr->test.duration ||
6412 attr->test.repeat || attr->test.flags)
6413 return -EINVAL;
6414
6415 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
6416 if (IS_ERR(prog))
6417 return PTR_ERR(prog);
6418
6419 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6420 attr->test.ctx_size_in > U16_MAX) {
6421 bpf_prog_put(prog);
6422 return -EINVAL;
6423 }
6424
6425 run_ctx.bpf_cookie = 0;
6426 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6427 /* recursion detected */
6428 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6429 bpf_prog_put(prog);
6430 return -EBUSY;
6431 }
6432 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6433 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6434 &run_ctx);
6435 bpf_prog_put(prog);
6436 return 0;
6437 #endif
6438 default:
6439 return ____bpf_sys_bpf(cmd, attr, size);
6440 }
6441 }
6442 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL");
6443
6444 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6445 .func = bpf_sys_bpf,
6446 .gpl_only = false,
6447 .ret_type = RET_INTEGER,
6448 .arg1_type = ARG_ANYTHING,
6449 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
6450 .arg3_type = ARG_CONST_SIZE,
6451 };
6452
6453 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6454 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6455 {
6456 return bpf_base_func_proto(func_id, prog);
6457 }
6458
BPF_CALL_1(bpf_sys_close,u32,fd)6459 BPF_CALL_1(bpf_sys_close, u32, fd)
6460 {
6461 /* When bpf program calls this helper there should not be
6462 * an fdget() without matching completed fdput().
6463 * This helper is allowed in the following callchain only:
6464 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6465 */
6466 return close_fd(fd);
6467 }
6468
6469 static const struct bpf_func_proto bpf_sys_close_proto = {
6470 .func = bpf_sys_close,
6471 .gpl_only = false,
6472 .ret_type = RET_INTEGER,
6473 .arg1_type = ARG_ANYTHING,
6474 };
6475
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6476 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6477 {
6478 *res = 0;
6479 if (flags)
6480 return -EINVAL;
6481
6482 if (name_sz <= 1 || name[name_sz - 1])
6483 return -EINVAL;
6484
6485 if (!bpf_dump_raw_ok(current_cred()))
6486 return -EPERM;
6487
6488 *res = kallsyms_lookup_name(name);
6489 return *res ? 0 : -ENOENT;
6490 }
6491
6492 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6493 .func = bpf_kallsyms_lookup_name,
6494 .gpl_only = false,
6495 .ret_type = RET_INTEGER,
6496 .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
6497 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
6498 .arg3_type = ARG_ANYTHING,
6499 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6500 .arg4_size = sizeof(u64),
6501 };
6502
6503 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6504 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6505 {
6506 switch (func_id) {
6507 case BPF_FUNC_sys_bpf:
6508 return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6509 ? NULL : &bpf_sys_bpf_proto;
6510 case BPF_FUNC_btf_find_by_name_kind:
6511 return &bpf_btf_find_by_name_kind_proto;
6512 case BPF_FUNC_sys_close:
6513 return &bpf_sys_close_proto;
6514 case BPF_FUNC_kallsyms_lookup_name:
6515 return &bpf_kallsyms_lookup_name_proto;
6516 default:
6517 return tracing_prog_func_proto(func_id, prog);
6518 }
6519 }
6520
6521 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6522 .get_func_proto = syscall_prog_func_proto,
6523 .is_valid_access = syscall_prog_is_valid_access,
6524 };
6525
6526 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6527 .test_run = bpf_prog_test_run_syscall,
6528 };
6529
6530 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6531 static int bpf_stats_handler(const struct ctl_table *table, int write,
6532 void *buffer, size_t *lenp, loff_t *ppos)
6533 {
6534 struct static_key *key = (struct static_key *)table->data;
6535 static int saved_val;
6536 int val, ret;
6537 struct ctl_table tmp = {
6538 .data = &val,
6539 .maxlen = sizeof(val),
6540 .mode = table->mode,
6541 .extra1 = SYSCTL_ZERO,
6542 .extra2 = SYSCTL_ONE,
6543 };
6544
6545 if (write && !capable(CAP_SYS_ADMIN))
6546 return -EPERM;
6547
6548 mutex_lock(&bpf_stats_enabled_mutex);
6549 val = saved_val;
6550 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6551 if (write && !ret && val != saved_val) {
6552 if (val)
6553 static_key_slow_inc(key);
6554 else
6555 static_key_slow_dec(key);
6556 saved_val = val;
6557 }
6558 mutex_unlock(&bpf_stats_enabled_mutex);
6559 return ret;
6560 }
6561
unpriv_ebpf_notify(int new_state)6562 void __weak unpriv_ebpf_notify(int new_state)
6563 {
6564 }
6565
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6566 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6567 void *buffer, size_t *lenp, loff_t *ppos)
6568 {
6569 int ret, unpriv_enable = *(int *)table->data;
6570 bool locked_state = unpriv_enable == 1;
6571 struct ctl_table tmp = *table;
6572
6573 if (write && !capable(CAP_SYS_ADMIN))
6574 return -EPERM;
6575
6576 tmp.data = &unpriv_enable;
6577 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6578 if (write && !ret) {
6579 if (locked_state && unpriv_enable != 1)
6580 return -EPERM;
6581 *(int *)table->data = unpriv_enable;
6582 }
6583
6584 if (write)
6585 unpriv_ebpf_notify(unpriv_enable);
6586
6587 return ret;
6588 }
6589
6590 static const struct ctl_table bpf_syscall_table[] = {
6591 {
6592 .procname = "unprivileged_bpf_disabled",
6593 .data = &sysctl_unprivileged_bpf_disabled,
6594 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
6595 .mode = 0644,
6596 .proc_handler = bpf_unpriv_handler,
6597 .extra1 = SYSCTL_ZERO,
6598 .extra2 = SYSCTL_TWO,
6599 },
6600 {
6601 .procname = "bpf_stats_enabled",
6602 .data = &bpf_stats_enabled_key.key,
6603 .mode = 0644,
6604 .proc_handler = bpf_stats_handler,
6605 },
6606 };
6607
bpf_syscall_sysctl_init(void)6608 static int __init bpf_syscall_sysctl_init(void)
6609 {
6610 register_sysctl_init("kernel", bpf_syscall_table);
6611 return 0;
6612 }
6613 late_initcall(bpf_syscall_sysctl_init);
6614 #endif /* CONFIG_SYSCTL */
6615