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