1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 */
4 #include <linux/bpf.h>
5 #include <linux/bpf-cgroup.h>
6 #include <linux/bpf_trace.h>
7 #include <linux/bpf_lirc.h>
8 #include <linux/bpf_verifier.h>
9 #include <linux/bsearch.h>
10 #include <linux/btf.h>
11 #include <linux/syscalls.h>
12 #include <linux/slab.h>
13 #include <linux/sched/signal.h>
14 #include <linux/vmalloc.h>
15 #include <linux/mmzone.h>
16 #include <linux/anon_inodes.h>
17 #include <linux/fdtable.h>
18 #include <linux/file.h>
19 #include <linux/fs.h>
20 #include <linux/license.h>
21 #include <linux/filter.h>
22 #include <linux/kernel.h>
23 #include <linux/idr.h>
24 #include <linux/cred.h>
25 #include <linux/timekeeping.h>
26 #include <linux/ctype.h>
27 #include <linux/nospec.h>
28 #include <linux/audit.h>
29 #include <uapi/linux/btf.h>
30 #include <linux/pgtable.h>
31 #include <linux/bpf_lsm.h>
32 #include <linux/poll.h>
33 #include <linux/sort.h>
34 #include <linux/bpf-netns.h>
35 #include <linux/rcupdate_trace.h>
36 #include <linux/memcontrol.h>
37 #include <linux/trace_events.h>
38 #include <linux/tracepoint.h>
39
40 #include <net/netfilter/nf_bpf_link.h>
41 #include <net/netkit.h>
42 #include <net/tcx.h>
43
44 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
45 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
46 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
47 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
48 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
49 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
50 IS_FD_HASH(map))
51
52 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY)
53
54 DEFINE_PER_CPU(int, bpf_prog_active);
55 static DEFINE_IDR(prog_idr);
56 static DEFINE_SPINLOCK(prog_idr_lock);
57 static DEFINE_IDR(map_idr);
58 static DEFINE_SPINLOCK(map_idr_lock);
59 static DEFINE_IDR(link_idr);
60 static DEFINE_SPINLOCK(link_idr_lock);
61
62 int sysctl_unprivileged_bpf_disabled __read_mostly =
63 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
64
65 static const struct bpf_map_ops * const bpf_map_types[] = {
66 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
67 #define BPF_MAP_TYPE(_id, _ops) \
68 [_id] = &_ops,
69 #define BPF_LINK_TYPE(_id, _name)
70 #include <linux/bpf_types.h>
71 #undef BPF_PROG_TYPE
72 #undef BPF_MAP_TYPE
73 #undef BPF_LINK_TYPE
74 };
75
76 /*
77 * If we're handed a bigger struct than we know of, ensure all the unknown bits
78 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
79 * we don't know about yet.
80 *
81 * There is a ToCToU between this function call and the following
82 * copy_from_user() call. However, this is not a concern since this function is
83 * meant to be a future-proofing of bits.
84 */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)85 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
86 size_t expected_size,
87 size_t actual_size)
88 {
89 int res;
90
91 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
92 return -E2BIG;
93
94 if (actual_size <= expected_size)
95 return 0;
96
97 if (uaddr.is_kernel)
98 res = memchr_inv(uaddr.kernel + expected_size, 0,
99 actual_size - expected_size) == NULL;
100 else
101 res = check_zeroed_user(uaddr.user + expected_size,
102 actual_size - expected_size);
103 if (res < 0)
104 return res;
105 return res ? 0 : -E2BIG;
106 }
107
108 const struct bpf_map_ops bpf_map_offload_ops = {
109 .map_meta_equal = bpf_map_meta_equal,
110 .map_alloc = bpf_map_offload_map_alloc,
111 .map_free = bpf_map_offload_map_free,
112 .map_check_btf = map_check_no_btf,
113 .map_mem_usage = bpf_map_offload_map_mem_usage,
114 };
115
bpf_map_write_active_inc(struct bpf_map * map)116 static void bpf_map_write_active_inc(struct bpf_map *map)
117 {
118 atomic64_inc(&map->writecnt);
119 }
120
bpf_map_write_active_dec(struct bpf_map * map)121 static void bpf_map_write_active_dec(struct bpf_map *map)
122 {
123 atomic64_dec(&map->writecnt);
124 }
125
bpf_map_write_active(const struct bpf_map * map)126 bool bpf_map_write_active(const struct bpf_map *map)
127 {
128 return atomic64_read(&map->writecnt) != 0;
129 }
130
bpf_map_value_size(const struct bpf_map * map)131 static u32 bpf_map_value_size(const struct bpf_map *map)
132 {
133 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
134 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
135 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
136 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
137 return round_up(map->value_size, 8) * num_possible_cpus();
138 else if (IS_FD_MAP(map))
139 return sizeof(u32);
140 else
141 return map->value_size;
142 }
143
maybe_wait_bpf_programs(struct bpf_map * map)144 static void maybe_wait_bpf_programs(struct bpf_map *map)
145 {
146 /* Wait for any running non-sleepable BPF programs to complete so that
147 * userspace, when we return to it, knows that all non-sleepable
148 * programs that could be running use the new map value. For sleepable
149 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
150 * for the completions of these programs, but considering the waiting
151 * time can be very long and userspace may think it will hang forever,
152 * so don't handle sleepable BPF programs now.
153 */
154 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
155 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
156 synchronize_rcu();
157 }
158
unpin_uptr_kaddr(void * kaddr)159 static void unpin_uptr_kaddr(void *kaddr)
160 {
161 if (kaddr)
162 unpin_user_page(virt_to_page(kaddr));
163 }
164
__bpf_obj_unpin_uptrs(struct btf_record * rec,u32 cnt,void * obj)165 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj)
166 {
167 const struct btf_field *field;
168 void **uptr_addr;
169 int i;
170
171 for (i = 0, field = rec->fields; i < cnt; i++, field++) {
172 if (field->type != BPF_UPTR)
173 continue;
174
175 uptr_addr = obj + field->offset;
176 unpin_uptr_kaddr(*uptr_addr);
177 }
178 }
179
bpf_obj_unpin_uptrs(struct btf_record * rec,void * obj)180 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj)
181 {
182 if (!btf_record_has_field(rec, BPF_UPTR))
183 return;
184
185 __bpf_obj_unpin_uptrs(rec, rec->cnt, obj);
186 }
187
bpf_obj_pin_uptrs(struct btf_record * rec,void * obj)188 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj)
189 {
190 const struct btf_field *field;
191 const struct btf_type *t;
192 unsigned long start, end;
193 struct page *page;
194 void **uptr_addr;
195 int i, err;
196
197 if (!btf_record_has_field(rec, BPF_UPTR))
198 return 0;
199
200 for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) {
201 if (field->type != BPF_UPTR)
202 continue;
203
204 uptr_addr = obj + field->offset;
205 start = *(unsigned long *)uptr_addr;
206 if (!start)
207 continue;
208
209 t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id);
210 /* t->size was checked for zero before */
211 if (check_add_overflow(start, t->size - 1, &end)) {
212 err = -EFAULT;
213 goto unpin_all;
214 }
215
216 /* The uptr's struct cannot span across two pages */
217 if ((start & PAGE_MASK) != (end & PAGE_MASK)) {
218 err = -EOPNOTSUPP;
219 goto unpin_all;
220 }
221
222 err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page);
223 if (err != 1)
224 goto unpin_all;
225
226 if (PageHighMem(page)) {
227 err = -EOPNOTSUPP;
228 unpin_user_page(page);
229 goto unpin_all;
230 }
231
232 *uptr_addr = page_address(page) + offset_in_page(start);
233 }
234
235 return 0;
236
237 unpin_all:
238 __bpf_obj_unpin_uptrs(rec, i, obj);
239 return err;
240 }
241
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)242 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
243 void *key, void *value, __u64 flags)
244 {
245 int err;
246
247 /* Need to create a kthread, thus must support schedule */
248 if (bpf_map_is_offloaded(map)) {
249 return bpf_map_offload_update_elem(map, key, value, flags);
250 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
251 map->map_type == BPF_MAP_TYPE_ARENA ||
252 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
253 return map->ops->map_update_elem(map, key, value, flags);
254 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
255 map->map_type == BPF_MAP_TYPE_SOCKMAP) {
256 return sock_map_update_elem_sys(map, key, value, flags);
257 } else if (IS_FD_PROG_ARRAY(map)) {
258 return bpf_fd_array_map_update_elem(map, map_file, key, value,
259 flags);
260 }
261
262 bpf_disable_instrumentation();
263 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
264 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
265 err = bpf_percpu_hash_update(map, key, value, flags);
266 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
267 err = bpf_percpu_array_update(map, key, value, flags);
268 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
269 err = bpf_percpu_cgroup_storage_update(map, key, value,
270 flags);
271 } else if (IS_FD_ARRAY(map)) {
272 err = bpf_fd_array_map_update_elem(map, map_file, key, value,
273 flags);
274 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
275 err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
276 flags);
277 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
278 /* rcu_read_lock() is not needed */
279 err = bpf_fd_reuseport_array_update_elem(map, key, value,
280 flags);
281 } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
282 map->map_type == BPF_MAP_TYPE_STACK ||
283 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
284 err = map->ops->map_push_elem(map, value, flags);
285 } else {
286 err = bpf_obj_pin_uptrs(map->record, value);
287 if (!err) {
288 rcu_read_lock();
289 err = map->ops->map_update_elem(map, key, value, flags);
290 rcu_read_unlock();
291 if (err)
292 bpf_obj_unpin_uptrs(map->record, value);
293 }
294 }
295 bpf_enable_instrumentation();
296
297 return err;
298 }
299
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)300 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
301 __u64 flags)
302 {
303 void *ptr;
304 int err;
305
306 if (bpf_map_is_offloaded(map))
307 return bpf_map_offload_lookup_elem(map, key, value);
308
309 bpf_disable_instrumentation();
310 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
311 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
312 err = bpf_percpu_hash_copy(map, key, value);
313 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
314 err = bpf_percpu_array_copy(map, key, value);
315 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
316 err = bpf_percpu_cgroup_storage_copy(map, key, value);
317 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
318 err = bpf_stackmap_copy(map, key, value);
319 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
320 err = bpf_fd_array_map_lookup_elem(map, key, value);
321 } else if (IS_FD_HASH(map)) {
322 err = bpf_fd_htab_map_lookup_elem(map, key, value);
323 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
324 err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
325 } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
326 map->map_type == BPF_MAP_TYPE_STACK ||
327 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
328 err = map->ops->map_peek_elem(map, value);
329 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
330 /* struct_ops map requires directly updating "value" */
331 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
332 } else {
333 rcu_read_lock();
334 if (map->ops->map_lookup_elem_sys_only)
335 ptr = map->ops->map_lookup_elem_sys_only(map, key);
336 else
337 ptr = map->ops->map_lookup_elem(map, key);
338 if (IS_ERR(ptr)) {
339 err = PTR_ERR(ptr);
340 } else if (!ptr) {
341 err = -ENOENT;
342 } else {
343 err = 0;
344 if (flags & BPF_F_LOCK)
345 /* lock 'ptr' and copy everything but lock */
346 copy_map_value_locked(map, value, ptr, true);
347 else
348 copy_map_value(map, value, ptr);
349 /* mask lock and timer, since value wasn't zero inited */
350 check_and_init_map_value(map, value);
351 }
352 rcu_read_unlock();
353 }
354
355 bpf_enable_instrumentation();
356
357 return err;
358 }
359
360 /* Please, do not use this function outside from the map creation path
361 * (e.g. in map update path) without taking care of setting the active
362 * memory cgroup (see at bpf_map_kmalloc_node() for example).
363 */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)364 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
365 {
366 /* We really just want to fail instead of triggering OOM killer
367 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
368 * which is used for lower order allocation requests.
369 *
370 * It has been observed that higher order allocation requests done by
371 * vmalloc with __GFP_NORETRY being set might fail due to not trying
372 * to reclaim memory from the page cache, thus we set
373 * __GFP_RETRY_MAYFAIL to avoid such situations.
374 */
375
376 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
377 unsigned int flags = 0;
378 unsigned long align = 1;
379 void *area;
380
381 if (size >= SIZE_MAX)
382 return NULL;
383
384 /* kmalloc()'ed memory can't be mmap()'ed */
385 if (mmapable) {
386 BUG_ON(!PAGE_ALIGNED(size));
387 align = SHMLBA;
388 flags = VM_USERMAP;
389 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
390 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
391 numa_node);
392 if (area != NULL)
393 return area;
394 }
395
396 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
397 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
398 flags, numa_node, __builtin_return_address(0));
399 }
400
bpf_map_area_alloc(u64 size,int numa_node)401 void *bpf_map_area_alloc(u64 size, int numa_node)
402 {
403 return __bpf_map_area_alloc(size, numa_node, false);
404 }
405
bpf_map_area_mmapable_alloc(u64 size,int numa_node)406 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
407 {
408 return __bpf_map_area_alloc(size, numa_node, true);
409 }
410
bpf_map_area_free(void * area)411 void bpf_map_area_free(void *area)
412 {
413 kvfree(area);
414 }
415
bpf_map_flags_retain_permanent(u32 flags)416 static u32 bpf_map_flags_retain_permanent(u32 flags)
417 {
418 /* Some map creation flags are not tied to the map object but
419 * rather to the map fd instead, so they have no meaning upon
420 * map object inspection since multiple file descriptors with
421 * different (access) properties can exist here. Thus, given
422 * this has zero meaning for the map itself, lets clear these
423 * from here.
424 */
425 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
426 }
427
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)428 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
429 {
430 map->map_type = attr->map_type;
431 map->key_size = attr->key_size;
432 map->value_size = attr->value_size;
433 map->max_entries = attr->max_entries;
434 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
435 map->numa_node = bpf_map_attr_numa_node(attr);
436 map->map_extra = attr->map_extra;
437 }
438
bpf_map_alloc_id(struct bpf_map * map)439 static int bpf_map_alloc_id(struct bpf_map *map)
440 {
441 int id;
442
443 idr_preload(GFP_KERNEL);
444 spin_lock_bh(&map_idr_lock);
445 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
446 if (id > 0)
447 map->id = id;
448 spin_unlock_bh(&map_idr_lock);
449 idr_preload_end();
450
451 if (WARN_ON_ONCE(!id))
452 return -ENOSPC;
453
454 return id > 0 ? 0 : id;
455 }
456
bpf_map_free_id(struct bpf_map * map)457 void bpf_map_free_id(struct bpf_map *map)
458 {
459 unsigned long flags;
460
461 /* Offloaded maps are removed from the IDR store when their device
462 * disappears - even if someone holds an fd to them they are unusable,
463 * the memory is gone, all ops will fail; they are simply waiting for
464 * refcnt to drop to be freed.
465 */
466 if (!map->id)
467 return;
468
469 spin_lock_irqsave(&map_idr_lock, flags);
470
471 idr_remove(&map_idr, map->id);
472 map->id = 0;
473
474 spin_unlock_irqrestore(&map_idr_lock, flags);
475 }
476
477 #ifdef CONFIG_MEMCG
bpf_map_save_memcg(struct bpf_map * map)478 static void bpf_map_save_memcg(struct bpf_map *map)
479 {
480 /* Currently if a map is created by a process belonging to the root
481 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
482 * So we have to check map->objcg for being NULL each time it's
483 * being used.
484 */
485 if (memcg_bpf_enabled())
486 map->objcg = get_obj_cgroup_from_current();
487 }
488
bpf_map_release_memcg(struct bpf_map * map)489 static void bpf_map_release_memcg(struct bpf_map *map)
490 {
491 if (map->objcg)
492 obj_cgroup_put(map->objcg);
493 }
494
bpf_map_get_memcg(const struct bpf_map * map)495 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
496 {
497 if (map->objcg)
498 return get_mem_cgroup_from_objcg(map->objcg);
499
500 return root_mem_cgroup;
501 }
502
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)503 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
504 int node)
505 {
506 struct mem_cgroup *memcg, *old_memcg;
507 void *ptr;
508
509 memcg = bpf_map_get_memcg(map);
510 old_memcg = set_active_memcg(memcg);
511 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
512 set_active_memcg(old_memcg);
513 mem_cgroup_put(memcg);
514
515 return ptr;
516 }
517
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)518 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
519 {
520 struct mem_cgroup *memcg, *old_memcg;
521 void *ptr;
522
523 memcg = bpf_map_get_memcg(map);
524 old_memcg = set_active_memcg(memcg);
525 ptr = kzalloc(size, flags | __GFP_ACCOUNT);
526 set_active_memcg(old_memcg);
527 mem_cgroup_put(memcg);
528
529 return ptr;
530 }
531
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)532 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
533 gfp_t flags)
534 {
535 struct mem_cgroup *memcg, *old_memcg;
536 void *ptr;
537
538 memcg = bpf_map_get_memcg(map);
539 old_memcg = set_active_memcg(memcg);
540 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
541 set_active_memcg(old_memcg);
542 mem_cgroup_put(memcg);
543
544 return ptr;
545 }
546
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)547 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
548 size_t align, gfp_t flags)
549 {
550 struct mem_cgroup *memcg, *old_memcg;
551 void __percpu *ptr;
552
553 memcg = bpf_map_get_memcg(map);
554 old_memcg = set_active_memcg(memcg);
555 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
556 set_active_memcg(old_memcg);
557 mem_cgroup_put(memcg);
558
559 return ptr;
560 }
561
562 #else
bpf_map_save_memcg(struct bpf_map * map)563 static void bpf_map_save_memcg(struct bpf_map *map)
564 {
565 }
566
bpf_map_release_memcg(struct bpf_map * map)567 static void bpf_map_release_memcg(struct bpf_map *map)
568 {
569 }
570 #endif
571
can_alloc_pages(void)572 static bool can_alloc_pages(void)
573 {
574 return preempt_count() == 0 && !irqs_disabled() &&
575 !IS_ENABLED(CONFIG_PREEMPT_RT);
576 }
577
__bpf_alloc_page(int nid)578 static struct page *__bpf_alloc_page(int nid)
579 {
580 if (!can_alloc_pages())
581 return try_alloc_pages(nid, 0);
582
583 return alloc_pages_node(nid,
584 GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
585 | __GFP_NOWARN,
586 0);
587 }
588
bpf_map_alloc_pages(const struct bpf_map * map,int nid,unsigned long nr_pages,struct page ** pages)589 int bpf_map_alloc_pages(const struct bpf_map *map, int nid,
590 unsigned long nr_pages, struct page **pages)
591 {
592 unsigned long i, j;
593 struct page *pg;
594 int ret = 0;
595 #ifdef CONFIG_MEMCG
596 struct mem_cgroup *memcg, *old_memcg;
597
598 memcg = bpf_map_get_memcg(map);
599 old_memcg = set_active_memcg(memcg);
600 #endif
601 for (i = 0; i < nr_pages; i++) {
602 pg = __bpf_alloc_page(nid);
603
604 if (pg) {
605 pages[i] = pg;
606 continue;
607 }
608 for (j = 0; j < i; j++)
609 free_pages_nolock(pages[j], 0);
610 ret = -ENOMEM;
611 break;
612 }
613
614 #ifdef CONFIG_MEMCG
615 set_active_memcg(old_memcg);
616 mem_cgroup_put(memcg);
617 #endif
618 return ret;
619 }
620
621
btf_field_cmp(const void * a,const void * b)622 static int btf_field_cmp(const void *a, const void *b)
623 {
624 const struct btf_field *f1 = a, *f2 = b;
625
626 if (f1->offset < f2->offset)
627 return -1;
628 else if (f1->offset > f2->offset)
629 return 1;
630 return 0;
631 }
632
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)633 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
634 u32 field_mask)
635 {
636 struct btf_field *field;
637
638 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
639 return NULL;
640 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
641 if (!field || !(field->type & field_mask))
642 return NULL;
643 return field;
644 }
645
btf_record_free(struct btf_record * rec)646 void btf_record_free(struct btf_record *rec)
647 {
648 int i;
649
650 if (IS_ERR_OR_NULL(rec))
651 return;
652 for (i = 0; i < rec->cnt; i++) {
653 switch (rec->fields[i].type) {
654 case BPF_KPTR_UNREF:
655 case BPF_KPTR_REF:
656 case BPF_KPTR_PERCPU:
657 case BPF_UPTR:
658 if (rec->fields[i].kptr.module)
659 module_put(rec->fields[i].kptr.module);
660 if (btf_is_kernel(rec->fields[i].kptr.btf))
661 btf_put(rec->fields[i].kptr.btf);
662 break;
663 case BPF_LIST_HEAD:
664 case BPF_LIST_NODE:
665 case BPF_RB_ROOT:
666 case BPF_RB_NODE:
667 case BPF_SPIN_LOCK:
668 case BPF_RES_SPIN_LOCK:
669 case BPF_TIMER:
670 case BPF_REFCOUNT:
671 case BPF_WORKQUEUE:
672 /* Nothing to release */
673 break;
674 default:
675 WARN_ON_ONCE(1);
676 continue;
677 }
678 }
679 kfree(rec);
680 }
681
bpf_map_free_record(struct bpf_map * map)682 void bpf_map_free_record(struct bpf_map *map)
683 {
684 btf_record_free(map->record);
685 map->record = NULL;
686 }
687
btf_record_dup(const struct btf_record * rec)688 struct btf_record *btf_record_dup(const struct btf_record *rec)
689 {
690 const struct btf_field *fields;
691 struct btf_record *new_rec;
692 int ret, size, i;
693
694 if (IS_ERR_OR_NULL(rec))
695 return NULL;
696 size = offsetof(struct btf_record, fields[rec->cnt]);
697 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
698 if (!new_rec)
699 return ERR_PTR(-ENOMEM);
700 /* Do a deep copy of the btf_record */
701 fields = rec->fields;
702 new_rec->cnt = 0;
703 for (i = 0; i < rec->cnt; i++) {
704 switch (fields[i].type) {
705 case BPF_KPTR_UNREF:
706 case BPF_KPTR_REF:
707 case BPF_KPTR_PERCPU:
708 case BPF_UPTR:
709 if (btf_is_kernel(fields[i].kptr.btf))
710 btf_get(fields[i].kptr.btf);
711 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
712 ret = -ENXIO;
713 goto free;
714 }
715 break;
716 case BPF_LIST_HEAD:
717 case BPF_LIST_NODE:
718 case BPF_RB_ROOT:
719 case BPF_RB_NODE:
720 case BPF_SPIN_LOCK:
721 case BPF_RES_SPIN_LOCK:
722 case BPF_TIMER:
723 case BPF_REFCOUNT:
724 case BPF_WORKQUEUE:
725 /* Nothing to acquire */
726 break;
727 default:
728 ret = -EFAULT;
729 WARN_ON_ONCE(1);
730 goto free;
731 }
732 new_rec->cnt++;
733 }
734 return new_rec;
735 free:
736 btf_record_free(new_rec);
737 return ERR_PTR(ret);
738 }
739
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)740 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
741 {
742 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
743 int size;
744
745 if (!a_has_fields && !b_has_fields)
746 return true;
747 if (a_has_fields != b_has_fields)
748 return false;
749 if (rec_a->cnt != rec_b->cnt)
750 return false;
751 size = offsetof(struct btf_record, fields[rec_a->cnt]);
752 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
753 * members are zeroed out. So memcmp is safe to do without worrying
754 * about padding/unused fields.
755 *
756 * While spin_lock, timer, and kptr have no relation to map BTF,
757 * list_head metadata is specific to map BTF, the btf and value_rec
758 * members in particular. btf is the map BTF, while value_rec points to
759 * btf_record in that map BTF.
760 *
761 * So while by default, we don't rely on the map BTF (which the records
762 * were parsed from) matching for both records, which is not backwards
763 * compatible, in case list_head is part of it, we implicitly rely on
764 * that by way of depending on memcmp succeeding for it.
765 */
766 return !memcmp(rec_a, rec_b, size);
767 }
768
bpf_obj_free_timer(const struct btf_record * rec,void * obj)769 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
770 {
771 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
772 return;
773 bpf_timer_cancel_and_free(obj + rec->timer_off);
774 }
775
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)776 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
777 {
778 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
779 return;
780 bpf_wq_cancel_and_free(obj + rec->wq_off);
781 }
782
bpf_obj_free_fields(const struct btf_record * rec,void * obj)783 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
784 {
785 const struct btf_field *fields;
786 int i;
787
788 if (IS_ERR_OR_NULL(rec))
789 return;
790 fields = rec->fields;
791 for (i = 0; i < rec->cnt; i++) {
792 struct btf_struct_meta *pointee_struct_meta;
793 const struct btf_field *field = &fields[i];
794 void *field_ptr = obj + field->offset;
795 void *xchgd_field;
796
797 switch (fields[i].type) {
798 case BPF_SPIN_LOCK:
799 case BPF_RES_SPIN_LOCK:
800 break;
801 case BPF_TIMER:
802 bpf_timer_cancel_and_free(field_ptr);
803 break;
804 case BPF_WORKQUEUE:
805 bpf_wq_cancel_and_free(field_ptr);
806 break;
807 case BPF_KPTR_UNREF:
808 WRITE_ONCE(*(u64 *)field_ptr, 0);
809 break;
810 case BPF_KPTR_REF:
811 case BPF_KPTR_PERCPU:
812 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
813 if (!xchgd_field)
814 break;
815
816 if (!btf_is_kernel(field->kptr.btf)) {
817 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
818 field->kptr.btf_id);
819 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
820 pointee_struct_meta->record : NULL,
821 fields[i].type == BPF_KPTR_PERCPU);
822 } else {
823 field->kptr.dtor(xchgd_field);
824 }
825 break;
826 case BPF_UPTR:
827 /* The caller ensured that no one is using the uptr */
828 unpin_uptr_kaddr(*(void **)field_ptr);
829 break;
830 case BPF_LIST_HEAD:
831 if (WARN_ON_ONCE(rec->spin_lock_off < 0))
832 continue;
833 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
834 break;
835 case BPF_RB_ROOT:
836 if (WARN_ON_ONCE(rec->spin_lock_off < 0))
837 continue;
838 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
839 break;
840 case BPF_LIST_NODE:
841 case BPF_RB_NODE:
842 case BPF_REFCOUNT:
843 break;
844 default:
845 WARN_ON_ONCE(1);
846 continue;
847 }
848 }
849 }
850
bpf_map_free(struct bpf_map * map)851 static void bpf_map_free(struct bpf_map *map)
852 {
853 struct btf_record *rec = map->record;
854 struct btf *btf = map->btf;
855
856 /* implementation dependent freeing. Disabling migration to simplify
857 * the free of values or special fields allocated from bpf memory
858 * allocator.
859 */
860 migrate_disable();
861 map->ops->map_free(map);
862 migrate_enable();
863
864 /* Delay freeing of btf_record for maps, as map_free
865 * callback usually needs access to them. It is better to do it here
866 * than require each callback to do the free itself manually.
867 *
868 * Note that the btf_record stashed in map->inner_map_meta->record was
869 * already freed using the map_free callback for map in map case which
870 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
871 * template bpf_map struct used during verification.
872 */
873 btf_record_free(rec);
874 /* Delay freeing of btf for maps, as map_free callback may need
875 * struct_meta info which will be freed with btf_put().
876 */
877 btf_put(btf);
878 }
879
880 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)881 static void bpf_map_free_deferred(struct work_struct *work)
882 {
883 struct bpf_map *map = container_of(work, struct bpf_map, work);
884
885 security_bpf_map_free(map);
886 bpf_map_release_memcg(map);
887 bpf_map_free(map);
888 }
889
bpf_map_put_uref(struct bpf_map * map)890 static void bpf_map_put_uref(struct bpf_map *map)
891 {
892 if (atomic64_dec_and_test(&map->usercnt)) {
893 if (map->ops->map_release_uref)
894 map->ops->map_release_uref(map);
895 }
896 }
897
bpf_map_free_in_work(struct bpf_map * map)898 static void bpf_map_free_in_work(struct bpf_map *map)
899 {
900 INIT_WORK(&map->work, bpf_map_free_deferred);
901 /* Avoid spawning kworkers, since they all might contend
902 * for the same mutex like slab_mutex.
903 */
904 queue_work(system_unbound_wq, &map->work);
905 }
906
bpf_map_free_rcu_gp(struct rcu_head * rcu)907 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
908 {
909 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
910 }
911
bpf_map_free_mult_rcu_gp(struct rcu_head * rcu)912 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
913 {
914 if (rcu_trace_implies_rcu_gp())
915 bpf_map_free_rcu_gp(rcu);
916 else
917 call_rcu(rcu, bpf_map_free_rcu_gp);
918 }
919
920 /* decrement map refcnt and schedule it for freeing via workqueue
921 * (underlying map implementation ops->map_free() might sleep)
922 */
bpf_map_put(struct bpf_map * map)923 void bpf_map_put(struct bpf_map *map)
924 {
925 if (atomic64_dec_and_test(&map->refcnt)) {
926 /* bpf_map_free_id() must be called first */
927 bpf_map_free_id(map);
928
929 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
930 if (READ_ONCE(map->free_after_mult_rcu_gp))
931 call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
932 else if (READ_ONCE(map->free_after_rcu_gp))
933 call_rcu(&map->rcu, bpf_map_free_rcu_gp);
934 else
935 bpf_map_free_in_work(map);
936 }
937 }
938 EXPORT_SYMBOL_GPL(bpf_map_put);
939
bpf_map_put_with_uref(struct bpf_map * map)940 void bpf_map_put_with_uref(struct bpf_map *map)
941 {
942 bpf_map_put_uref(map);
943 bpf_map_put(map);
944 }
945
bpf_map_release(struct inode * inode,struct file * filp)946 static int bpf_map_release(struct inode *inode, struct file *filp)
947 {
948 struct bpf_map *map = filp->private_data;
949
950 if (map->ops->map_release)
951 map->ops->map_release(map, filp);
952
953 bpf_map_put_with_uref(map);
954 return 0;
955 }
956
map_get_sys_perms(struct bpf_map * map,struct fd f)957 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
958 {
959 fmode_t mode = fd_file(f)->f_mode;
960
961 /* Our file permissions may have been overridden by global
962 * map permissions facing syscall side.
963 */
964 if (READ_ONCE(map->frozen))
965 mode &= ~FMODE_CAN_WRITE;
966 return mode;
967 }
968
969 #ifdef CONFIG_PROC_FS
970 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)971 static u64 bpf_map_memory_usage(const struct bpf_map *map)
972 {
973 return map->ops->map_mem_usage(map);
974 }
975
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)976 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
977 {
978 struct bpf_map *map = filp->private_data;
979 u32 type = 0, jited = 0;
980
981 if (map_type_contains_progs(map)) {
982 spin_lock(&map->owner.lock);
983 type = map->owner.type;
984 jited = map->owner.jited;
985 spin_unlock(&map->owner.lock);
986 }
987
988 seq_printf(m,
989 "map_type:\t%u\n"
990 "key_size:\t%u\n"
991 "value_size:\t%u\n"
992 "max_entries:\t%u\n"
993 "map_flags:\t%#x\n"
994 "map_extra:\t%#llx\n"
995 "memlock:\t%llu\n"
996 "map_id:\t%u\n"
997 "frozen:\t%u\n",
998 map->map_type,
999 map->key_size,
1000 map->value_size,
1001 map->max_entries,
1002 map->map_flags,
1003 (unsigned long long)map->map_extra,
1004 bpf_map_memory_usage(map),
1005 map->id,
1006 READ_ONCE(map->frozen));
1007 if (type) {
1008 seq_printf(m, "owner_prog_type:\t%u\n", type);
1009 seq_printf(m, "owner_jited:\t%u\n", jited);
1010 }
1011 }
1012 #endif
1013
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)1014 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
1015 loff_t *ppos)
1016 {
1017 /* We need this handler such that alloc_file() enables
1018 * f_mode with FMODE_CAN_READ.
1019 */
1020 return -EINVAL;
1021 }
1022
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1023 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1024 size_t siz, loff_t *ppos)
1025 {
1026 /* We need this handler such that alloc_file() enables
1027 * f_mode with FMODE_CAN_WRITE.
1028 */
1029 return -EINVAL;
1030 }
1031
1032 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1033 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1034 {
1035 struct bpf_map *map = vma->vm_file->private_data;
1036
1037 if (vma->vm_flags & VM_MAYWRITE)
1038 bpf_map_write_active_inc(map);
1039 }
1040
1041 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1042 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1043 {
1044 struct bpf_map *map = vma->vm_file->private_data;
1045
1046 if (vma->vm_flags & VM_MAYWRITE)
1047 bpf_map_write_active_dec(map);
1048 }
1049
1050 static const struct vm_operations_struct bpf_map_default_vmops = {
1051 .open = bpf_map_mmap_open,
1052 .close = bpf_map_mmap_close,
1053 };
1054
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1055 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1056 {
1057 struct bpf_map *map = filp->private_data;
1058 int err = 0;
1059
1060 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1061 return -ENOTSUPP;
1062
1063 if (!(vma->vm_flags & VM_SHARED))
1064 return -EINVAL;
1065
1066 mutex_lock(&map->freeze_mutex);
1067
1068 if (vma->vm_flags & VM_WRITE) {
1069 if (map->frozen) {
1070 err = -EPERM;
1071 goto out;
1072 }
1073 /* map is meant to be read-only, so do not allow mapping as
1074 * writable, because it's possible to leak a writable page
1075 * reference and allows user-space to still modify it after
1076 * freezing, while verifier will assume contents do not change
1077 */
1078 if (map->map_flags & BPF_F_RDONLY_PROG) {
1079 err = -EACCES;
1080 goto out;
1081 }
1082 bpf_map_write_active_inc(map);
1083 }
1084 out:
1085 mutex_unlock(&map->freeze_mutex);
1086 if (err)
1087 return err;
1088
1089 /* set default open/close callbacks */
1090 vma->vm_ops = &bpf_map_default_vmops;
1091 vma->vm_private_data = map;
1092 vm_flags_clear(vma, VM_MAYEXEC);
1093 /* If mapping is read-only, then disallow potentially re-mapping with
1094 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1095 * means that as far as BPF map's memory-mapped VMAs are concerned,
1096 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1097 * both should be set, so we can forget about VM_MAYWRITE and always
1098 * check just VM_WRITE
1099 */
1100 if (!(vma->vm_flags & VM_WRITE))
1101 vm_flags_clear(vma, VM_MAYWRITE);
1102
1103 err = map->ops->map_mmap(map, vma);
1104 if (err) {
1105 if (vma->vm_flags & VM_WRITE)
1106 bpf_map_write_active_dec(map);
1107 }
1108
1109 return err;
1110 }
1111
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1112 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1113 {
1114 struct bpf_map *map = filp->private_data;
1115
1116 if (map->ops->map_poll)
1117 return map->ops->map_poll(map, filp, pts);
1118
1119 return EPOLLERR;
1120 }
1121
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1122 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1123 unsigned long len, unsigned long pgoff,
1124 unsigned long flags)
1125 {
1126 struct bpf_map *map = filp->private_data;
1127
1128 if (map->ops->map_get_unmapped_area)
1129 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1130 #ifdef CONFIG_MMU
1131 return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
1132 #else
1133 return addr;
1134 #endif
1135 }
1136
1137 const struct file_operations bpf_map_fops = {
1138 #ifdef CONFIG_PROC_FS
1139 .show_fdinfo = bpf_map_show_fdinfo,
1140 #endif
1141 .release = bpf_map_release,
1142 .read = bpf_dummy_read,
1143 .write = bpf_dummy_write,
1144 .mmap = bpf_map_mmap,
1145 .poll = bpf_map_poll,
1146 .get_unmapped_area = bpf_get_unmapped_area,
1147 };
1148
bpf_map_new_fd(struct bpf_map * map,int flags)1149 int bpf_map_new_fd(struct bpf_map *map, int flags)
1150 {
1151 int ret;
1152
1153 ret = security_bpf_map(map, OPEN_FMODE(flags));
1154 if (ret < 0)
1155 return ret;
1156
1157 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1158 flags | O_CLOEXEC);
1159 }
1160
bpf_get_file_flag(int flags)1161 int bpf_get_file_flag(int flags)
1162 {
1163 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1164 return -EINVAL;
1165 if (flags & BPF_F_RDONLY)
1166 return O_RDONLY;
1167 if (flags & BPF_F_WRONLY)
1168 return O_WRONLY;
1169 return O_RDWR;
1170 }
1171
1172 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1173 #define CHECK_ATTR(CMD) \
1174 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1175 sizeof(attr->CMD##_LAST_FIELD), 0, \
1176 sizeof(*attr) - \
1177 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1178 sizeof(attr->CMD##_LAST_FIELD)) != NULL
1179
1180 /* dst and src must have at least "size" number of bytes.
1181 * Return strlen on success and < 0 on error.
1182 */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1183 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1184 {
1185 const char *end = src + size;
1186 const char *orig_src = src;
1187
1188 memset(dst, 0, size);
1189 /* Copy all isalnum(), '_' and '.' chars. */
1190 while (src < end && *src) {
1191 if (!isalnum(*src) &&
1192 *src != '_' && *src != '.')
1193 return -EINVAL;
1194 *dst++ = *src++;
1195 }
1196
1197 /* No '\0' found in "size" number of bytes */
1198 if (src == end)
1199 return -EINVAL;
1200
1201 return src - orig_src;
1202 }
1203
map_check_no_btf(const struct bpf_map * map,const struct btf * btf,const struct btf_type * key_type,const struct btf_type * value_type)1204 int map_check_no_btf(const struct bpf_map *map,
1205 const struct btf *btf,
1206 const struct btf_type *key_type,
1207 const struct btf_type *value_type)
1208 {
1209 return -ENOTSUPP;
1210 }
1211
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1212 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1213 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1214 {
1215 const struct btf_type *key_type, *value_type;
1216 u32 key_size, value_size;
1217 int ret = 0;
1218
1219 /* Some maps allow key to be unspecified. */
1220 if (btf_key_id) {
1221 key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1222 if (!key_type || key_size != map->key_size)
1223 return -EINVAL;
1224 } else {
1225 key_type = btf_type_by_id(btf, 0);
1226 if (!map->ops->map_check_btf)
1227 return -EINVAL;
1228 }
1229
1230 value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1231 if (!value_type || value_size != map->value_size)
1232 return -EINVAL;
1233
1234 map->record = btf_parse_fields(btf, value_type,
1235 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1236 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR,
1237 map->value_size);
1238 if (!IS_ERR_OR_NULL(map->record)) {
1239 int i;
1240
1241 if (!bpf_token_capable(token, CAP_BPF)) {
1242 ret = -EPERM;
1243 goto free_map_tab;
1244 }
1245 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1246 ret = -EACCES;
1247 goto free_map_tab;
1248 }
1249 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1250 switch (map->record->field_mask & (1 << i)) {
1251 case 0:
1252 continue;
1253 case BPF_SPIN_LOCK:
1254 case BPF_RES_SPIN_LOCK:
1255 if (map->map_type != BPF_MAP_TYPE_HASH &&
1256 map->map_type != BPF_MAP_TYPE_ARRAY &&
1257 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1258 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1259 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1260 map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1261 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1262 ret = -EOPNOTSUPP;
1263 goto free_map_tab;
1264 }
1265 break;
1266 case BPF_TIMER:
1267 case BPF_WORKQUEUE:
1268 if (map->map_type != BPF_MAP_TYPE_HASH &&
1269 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1270 map->map_type != BPF_MAP_TYPE_ARRAY) {
1271 ret = -EOPNOTSUPP;
1272 goto free_map_tab;
1273 }
1274 break;
1275 case BPF_KPTR_UNREF:
1276 case BPF_KPTR_REF:
1277 case BPF_KPTR_PERCPU:
1278 case BPF_REFCOUNT:
1279 if (map->map_type != BPF_MAP_TYPE_HASH &&
1280 map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1281 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1282 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1283 map->map_type != BPF_MAP_TYPE_ARRAY &&
1284 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1285 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1286 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1287 map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1288 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1289 ret = -EOPNOTSUPP;
1290 goto free_map_tab;
1291 }
1292 break;
1293 case BPF_UPTR:
1294 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1295 ret = -EOPNOTSUPP;
1296 goto free_map_tab;
1297 }
1298 break;
1299 case BPF_LIST_HEAD:
1300 case BPF_RB_ROOT:
1301 if (map->map_type != BPF_MAP_TYPE_HASH &&
1302 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1303 map->map_type != BPF_MAP_TYPE_ARRAY) {
1304 ret = -EOPNOTSUPP;
1305 goto free_map_tab;
1306 }
1307 break;
1308 default:
1309 /* Fail if map_type checks are missing for a field type */
1310 ret = -EOPNOTSUPP;
1311 goto free_map_tab;
1312 }
1313 }
1314 }
1315
1316 ret = btf_check_and_fixup_fields(btf, map->record);
1317 if (ret < 0)
1318 goto free_map_tab;
1319
1320 if (map->ops->map_check_btf) {
1321 ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1322 if (ret < 0)
1323 goto free_map_tab;
1324 }
1325
1326 return ret;
1327 free_map_tab:
1328 bpf_map_free_record(map);
1329 return ret;
1330 }
1331
bpf_net_capable(void)1332 static bool bpf_net_capable(void)
1333 {
1334 return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
1335 }
1336
1337 #define BPF_MAP_CREATE_LAST_FIELD map_token_fd
1338 /* called via syscall */
map_create(union bpf_attr * attr,bool kernel)1339 static int map_create(union bpf_attr *attr, bool kernel)
1340 {
1341 const struct bpf_map_ops *ops;
1342 struct bpf_token *token = NULL;
1343 int numa_node = bpf_map_attr_numa_node(attr);
1344 u32 map_type = attr->map_type;
1345 struct bpf_map *map;
1346 bool token_flag;
1347 int f_flags;
1348 int err;
1349
1350 err = CHECK_ATTR(BPF_MAP_CREATE);
1351 if (err)
1352 return -EINVAL;
1353
1354 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1355 * to avoid per-map type checks tripping on unknown flag
1356 */
1357 token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1358 attr->map_flags &= ~BPF_F_TOKEN_FD;
1359
1360 if (attr->btf_vmlinux_value_type_id) {
1361 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1362 attr->btf_key_type_id || attr->btf_value_type_id)
1363 return -EINVAL;
1364 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1365 return -EINVAL;
1366 }
1367
1368 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1369 attr->map_type != BPF_MAP_TYPE_ARENA &&
1370 attr->map_extra != 0)
1371 return -EINVAL;
1372
1373 f_flags = bpf_get_file_flag(attr->map_flags);
1374 if (f_flags < 0)
1375 return f_flags;
1376
1377 if (numa_node != NUMA_NO_NODE &&
1378 ((unsigned int)numa_node >= nr_node_ids ||
1379 !node_online(numa_node)))
1380 return -EINVAL;
1381
1382 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1383 map_type = attr->map_type;
1384 if (map_type >= ARRAY_SIZE(bpf_map_types))
1385 return -EINVAL;
1386 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1387 ops = bpf_map_types[map_type];
1388 if (!ops)
1389 return -EINVAL;
1390
1391 if (ops->map_alloc_check) {
1392 err = ops->map_alloc_check(attr);
1393 if (err)
1394 return err;
1395 }
1396 if (attr->map_ifindex)
1397 ops = &bpf_map_offload_ops;
1398 if (!ops->map_mem_usage)
1399 return -EINVAL;
1400
1401 if (token_flag) {
1402 token = bpf_token_get_from_fd(attr->map_token_fd);
1403 if (IS_ERR(token))
1404 return PTR_ERR(token);
1405
1406 /* if current token doesn't grant map creation permissions,
1407 * then we can't use this token, so ignore it and rely on
1408 * system-wide capabilities checks
1409 */
1410 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1411 !bpf_token_allow_map_type(token, attr->map_type)) {
1412 bpf_token_put(token);
1413 token = NULL;
1414 }
1415 }
1416
1417 err = -EPERM;
1418
1419 /* Intent here is for unprivileged_bpf_disabled to block BPF map
1420 * creation for unprivileged users; other actions depend
1421 * on fd availability and access to bpffs, so are dependent on
1422 * object creation success. Even with unprivileged BPF disabled,
1423 * capability checks are still carried out.
1424 */
1425 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1426 goto put_token;
1427
1428 /* check privileged map type permissions */
1429 switch (map_type) {
1430 case BPF_MAP_TYPE_ARRAY:
1431 case BPF_MAP_TYPE_PERCPU_ARRAY:
1432 case BPF_MAP_TYPE_PROG_ARRAY:
1433 case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1434 case BPF_MAP_TYPE_CGROUP_ARRAY:
1435 case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1436 case BPF_MAP_TYPE_HASH:
1437 case BPF_MAP_TYPE_PERCPU_HASH:
1438 case BPF_MAP_TYPE_HASH_OF_MAPS:
1439 case BPF_MAP_TYPE_RINGBUF:
1440 case BPF_MAP_TYPE_USER_RINGBUF:
1441 case BPF_MAP_TYPE_CGROUP_STORAGE:
1442 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1443 /* unprivileged */
1444 break;
1445 case BPF_MAP_TYPE_SK_STORAGE:
1446 case BPF_MAP_TYPE_INODE_STORAGE:
1447 case BPF_MAP_TYPE_TASK_STORAGE:
1448 case BPF_MAP_TYPE_CGRP_STORAGE:
1449 case BPF_MAP_TYPE_BLOOM_FILTER:
1450 case BPF_MAP_TYPE_LPM_TRIE:
1451 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1452 case BPF_MAP_TYPE_STACK_TRACE:
1453 case BPF_MAP_TYPE_QUEUE:
1454 case BPF_MAP_TYPE_STACK:
1455 case BPF_MAP_TYPE_LRU_HASH:
1456 case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1457 case BPF_MAP_TYPE_STRUCT_OPS:
1458 case BPF_MAP_TYPE_CPUMAP:
1459 case BPF_MAP_TYPE_ARENA:
1460 if (!bpf_token_capable(token, CAP_BPF))
1461 goto put_token;
1462 break;
1463 case BPF_MAP_TYPE_SOCKMAP:
1464 case BPF_MAP_TYPE_SOCKHASH:
1465 case BPF_MAP_TYPE_DEVMAP:
1466 case BPF_MAP_TYPE_DEVMAP_HASH:
1467 case BPF_MAP_TYPE_XSKMAP:
1468 if (!bpf_token_capable(token, CAP_NET_ADMIN))
1469 goto put_token;
1470 break;
1471 default:
1472 WARN(1, "unsupported map type %d", map_type);
1473 goto put_token;
1474 }
1475
1476 map = ops->map_alloc(attr);
1477 if (IS_ERR(map)) {
1478 err = PTR_ERR(map);
1479 goto put_token;
1480 }
1481 map->ops = ops;
1482 map->map_type = map_type;
1483
1484 err = bpf_obj_name_cpy(map->name, attr->map_name,
1485 sizeof(attr->map_name));
1486 if (err < 0)
1487 goto free_map;
1488
1489 atomic64_set(&map->refcnt, 1);
1490 atomic64_set(&map->usercnt, 1);
1491 mutex_init(&map->freeze_mutex);
1492 spin_lock_init(&map->owner.lock);
1493
1494 if (attr->btf_key_type_id || attr->btf_value_type_id ||
1495 /* Even the map's value is a kernel's struct,
1496 * the bpf_prog.o must have BTF to begin with
1497 * to figure out the corresponding kernel's
1498 * counter part. Thus, attr->btf_fd has
1499 * to be valid also.
1500 */
1501 attr->btf_vmlinux_value_type_id) {
1502 struct btf *btf;
1503
1504 btf = btf_get_by_fd(attr->btf_fd);
1505 if (IS_ERR(btf)) {
1506 err = PTR_ERR(btf);
1507 goto free_map;
1508 }
1509 if (btf_is_kernel(btf)) {
1510 btf_put(btf);
1511 err = -EACCES;
1512 goto free_map;
1513 }
1514 map->btf = btf;
1515
1516 if (attr->btf_value_type_id) {
1517 err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1518 attr->btf_value_type_id);
1519 if (err)
1520 goto free_map;
1521 }
1522
1523 map->btf_key_type_id = attr->btf_key_type_id;
1524 map->btf_value_type_id = attr->btf_value_type_id;
1525 map->btf_vmlinux_value_type_id =
1526 attr->btf_vmlinux_value_type_id;
1527 }
1528
1529 err = security_bpf_map_create(map, attr, token, kernel);
1530 if (err)
1531 goto free_map_sec;
1532
1533 err = bpf_map_alloc_id(map);
1534 if (err)
1535 goto free_map_sec;
1536
1537 bpf_map_save_memcg(map);
1538 bpf_token_put(token);
1539
1540 err = bpf_map_new_fd(map, f_flags);
1541 if (err < 0) {
1542 /* failed to allocate fd.
1543 * bpf_map_put_with_uref() is needed because the above
1544 * bpf_map_alloc_id() has published the map
1545 * to the userspace and the userspace may
1546 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1547 */
1548 bpf_map_put_with_uref(map);
1549 return err;
1550 }
1551
1552 return err;
1553
1554 free_map_sec:
1555 security_bpf_map_free(map);
1556 free_map:
1557 bpf_map_free(map);
1558 put_token:
1559 bpf_token_put(token);
1560 return err;
1561 }
1562
bpf_map_inc(struct bpf_map * map)1563 void bpf_map_inc(struct bpf_map *map)
1564 {
1565 atomic64_inc(&map->refcnt);
1566 }
1567 EXPORT_SYMBOL_GPL(bpf_map_inc);
1568
bpf_map_inc_with_uref(struct bpf_map * map)1569 void bpf_map_inc_with_uref(struct bpf_map *map)
1570 {
1571 atomic64_inc(&map->refcnt);
1572 atomic64_inc(&map->usercnt);
1573 }
1574 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1575
bpf_map_get(u32 ufd)1576 struct bpf_map *bpf_map_get(u32 ufd)
1577 {
1578 CLASS(fd, f)(ufd);
1579 struct bpf_map *map = __bpf_map_get(f);
1580
1581 if (!IS_ERR(map))
1582 bpf_map_inc(map);
1583
1584 return map;
1585 }
1586 EXPORT_SYMBOL(bpf_map_get);
1587
bpf_map_get_with_uref(u32 ufd)1588 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1589 {
1590 CLASS(fd, f)(ufd);
1591 struct bpf_map *map = __bpf_map_get(f);
1592
1593 if (!IS_ERR(map))
1594 bpf_map_inc_with_uref(map);
1595
1596 return map;
1597 }
1598
1599 /* map_idr_lock should have been held or the map should have been
1600 * protected by rcu read lock.
1601 */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1602 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1603 {
1604 int refold;
1605
1606 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1607 if (!refold)
1608 return ERR_PTR(-ENOENT);
1609 if (uref)
1610 atomic64_inc(&map->usercnt);
1611
1612 return map;
1613 }
1614
bpf_map_inc_not_zero(struct bpf_map * map)1615 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1616 {
1617 lockdep_assert(rcu_read_lock_held());
1618 return __bpf_map_inc_not_zero(map, false);
1619 }
1620 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1621
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1622 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1623 {
1624 return -ENOTSUPP;
1625 }
1626
__bpf_copy_key(void __user * ukey,u64 key_size)1627 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1628 {
1629 if (key_size)
1630 return vmemdup_user(ukey, key_size);
1631
1632 if (ukey)
1633 return ERR_PTR(-EINVAL);
1634
1635 return NULL;
1636 }
1637
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1638 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1639 {
1640 if (key_size)
1641 return kvmemdup_bpfptr(ukey, key_size);
1642
1643 if (!bpfptr_is_null(ukey))
1644 return ERR_PTR(-EINVAL);
1645
1646 return NULL;
1647 }
1648
1649 /* last field in 'union bpf_attr' used by this command */
1650 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1651
map_lookup_elem(union bpf_attr * attr)1652 static int map_lookup_elem(union bpf_attr *attr)
1653 {
1654 void __user *ukey = u64_to_user_ptr(attr->key);
1655 void __user *uvalue = u64_to_user_ptr(attr->value);
1656 struct bpf_map *map;
1657 void *key, *value;
1658 u32 value_size;
1659 int err;
1660
1661 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1662 return -EINVAL;
1663
1664 if (attr->flags & ~BPF_F_LOCK)
1665 return -EINVAL;
1666
1667 CLASS(fd, f)(attr->map_fd);
1668 map = __bpf_map_get(f);
1669 if (IS_ERR(map))
1670 return PTR_ERR(map);
1671 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1672 return -EPERM;
1673
1674 if ((attr->flags & BPF_F_LOCK) &&
1675 !btf_record_has_field(map->record, BPF_SPIN_LOCK))
1676 return -EINVAL;
1677
1678 key = __bpf_copy_key(ukey, map->key_size);
1679 if (IS_ERR(key))
1680 return PTR_ERR(key);
1681
1682 value_size = bpf_map_value_size(map);
1683
1684 err = -ENOMEM;
1685 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1686 if (!value)
1687 goto free_key;
1688
1689 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1690 if (copy_from_user(value, uvalue, value_size))
1691 err = -EFAULT;
1692 else
1693 err = bpf_map_copy_value(map, key, value, attr->flags);
1694 goto free_value;
1695 }
1696
1697 err = bpf_map_copy_value(map, key, value, attr->flags);
1698 if (err)
1699 goto free_value;
1700
1701 err = -EFAULT;
1702 if (copy_to_user(uvalue, value, value_size) != 0)
1703 goto free_value;
1704
1705 err = 0;
1706
1707 free_value:
1708 kvfree(value);
1709 free_key:
1710 kvfree(key);
1711 return err;
1712 }
1713
1714
1715 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1716
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1717 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1718 {
1719 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1720 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1721 struct bpf_map *map;
1722 void *key, *value;
1723 u32 value_size;
1724 int err;
1725
1726 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1727 return -EINVAL;
1728
1729 CLASS(fd, f)(attr->map_fd);
1730 map = __bpf_map_get(f);
1731 if (IS_ERR(map))
1732 return PTR_ERR(map);
1733 bpf_map_write_active_inc(map);
1734 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1735 err = -EPERM;
1736 goto err_put;
1737 }
1738
1739 if ((attr->flags & BPF_F_LOCK) &&
1740 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1741 err = -EINVAL;
1742 goto err_put;
1743 }
1744
1745 key = ___bpf_copy_key(ukey, map->key_size);
1746 if (IS_ERR(key)) {
1747 err = PTR_ERR(key);
1748 goto err_put;
1749 }
1750
1751 value_size = bpf_map_value_size(map);
1752 value = kvmemdup_bpfptr(uvalue, value_size);
1753 if (IS_ERR(value)) {
1754 err = PTR_ERR(value);
1755 goto free_key;
1756 }
1757
1758 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1759 if (!err)
1760 maybe_wait_bpf_programs(map);
1761
1762 kvfree(value);
1763 free_key:
1764 kvfree(key);
1765 err_put:
1766 bpf_map_write_active_dec(map);
1767 return err;
1768 }
1769
1770 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1771
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1772 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1773 {
1774 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1775 struct bpf_map *map;
1776 void *key;
1777 int err;
1778
1779 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1780 return -EINVAL;
1781
1782 CLASS(fd, f)(attr->map_fd);
1783 map = __bpf_map_get(f);
1784 if (IS_ERR(map))
1785 return PTR_ERR(map);
1786 bpf_map_write_active_inc(map);
1787 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1788 err = -EPERM;
1789 goto err_put;
1790 }
1791
1792 key = ___bpf_copy_key(ukey, map->key_size);
1793 if (IS_ERR(key)) {
1794 err = PTR_ERR(key);
1795 goto err_put;
1796 }
1797
1798 if (bpf_map_is_offloaded(map)) {
1799 err = bpf_map_offload_delete_elem(map, key);
1800 goto out;
1801 } else if (IS_FD_PROG_ARRAY(map) ||
1802 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1803 /* These maps require sleepable context */
1804 err = map->ops->map_delete_elem(map, key);
1805 goto out;
1806 }
1807
1808 bpf_disable_instrumentation();
1809 rcu_read_lock();
1810 err = map->ops->map_delete_elem(map, key);
1811 rcu_read_unlock();
1812 bpf_enable_instrumentation();
1813 if (!err)
1814 maybe_wait_bpf_programs(map);
1815 out:
1816 kvfree(key);
1817 err_put:
1818 bpf_map_write_active_dec(map);
1819 return err;
1820 }
1821
1822 /* last field in 'union bpf_attr' used by this command */
1823 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1824
map_get_next_key(union bpf_attr * attr)1825 static int map_get_next_key(union bpf_attr *attr)
1826 {
1827 void __user *ukey = u64_to_user_ptr(attr->key);
1828 void __user *unext_key = u64_to_user_ptr(attr->next_key);
1829 struct bpf_map *map;
1830 void *key, *next_key;
1831 int err;
1832
1833 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
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 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1841 return -EPERM;
1842
1843 if (ukey) {
1844 key = __bpf_copy_key(ukey, map->key_size);
1845 if (IS_ERR(key))
1846 return PTR_ERR(key);
1847 } else {
1848 key = NULL;
1849 }
1850
1851 err = -ENOMEM;
1852 next_key = kvmalloc(map->key_size, GFP_USER);
1853 if (!next_key)
1854 goto free_key;
1855
1856 if (bpf_map_is_offloaded(map)) {
1857 err = bpf_map_offload_get_next_key(map, key, next_key);
1858 goto out;
1859 }
1860
1861 rcu_read_lock();
1862 err = map->ops->map_get_next_key(map, key, next_key);
1863 rcu_read_unlock();
1864 out:
1865 if (err)
1866 goto free_next_key;
1867
1868 err = -EFAULT;
1869 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1870 goto free_next_key;
1871
1872 err = 0;
1873
1874 free_next_key:
1875 kvfree(next_key);
1876 free_key:
1877 kvfree(key);
1878 return err;
1879 }
1880
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1881 int generic_map_delete_batch(struct bpf_map *map,
1882 const union bpf_attr *attr,
1883 union bpf_attr __user *uattr)
1884 {
1885 void __user *keys = u64_to_user_ptr(attr->batch.keys);
1886 u32 cp, max_count;
1887 int err = 0;
1888 void *key;
1889
1890 if (attr->batch.elem_flags & ~BPF_F_LOCK)
1891 return -EINVAL;
1892
1893 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1894 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1895 return -EINVAL;
1896 }
1897
1898 max_count = attr->batch.count;
1899 if (!max_count)
1900 return 0;
1901
1902 if (put_user(0, &uattr->batch.count))
1903 return -EFAULT;
1904
1905 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1906 if (!key)
1907 return -ENOMEM;
1908
1909 for (cp = 0; cp < max_count; cp++) {
1910 err = -EFAULT;
1911 if (copy_from_user(key, keys + cp * map->key_size,
1912 map->key_size))
1913 break;
1914
1915 if (bpf_map_is_offloaded(map)) {
1916 err = bpf_map_offload_delete_elem(map, key);
1917 break;
1918 }
1919
1920 bpf_disable_instrumentation();
1921 rcu_read_lock();
1922 err = map->ops->map_delete_elem(map, key);
1923 rcu_read_unlock();
1924 bpf_enable_instrumentation();
1925 if (err)
1926 break;
1927 cond_resched();
1928 }
1929 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1930 err = -EFAULT;
1931
1932 kvfree(key);
1933
1934 return err;
1935 }
1936
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1937 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1938 const union bpf_attr *attr,
1939 union bpf_attr __user *uattr)
1940 {
1941 void __user *values = u64_to_user_ptr(attr->batch.values);
1942 void __user *keys = u64_to_user_ptr(attr->batch.keys);
1943 u32 value_size, cp, max_count;
1944 void *key, *value;
1945 int err = 0;
1946
1947 if (attr->batch.elem_flags & ~BPF_F_LOCK)
1948 return -EINVAL;
1949
1950 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1951 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1952 return -EINVAL;
1953 }
1954
1955 value_size = bpf_map_value_size(map);
1956
1957 max_count = attr->batch.count;
1958 if (!max_count)
1959 return 0;
1960
1961 if (put_user(0, &uattr->batch.count))
1962 return -EFAULT;
1963
1964 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1965 if (!key)
1966 return -ENOMEM;
1967
1968 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1969 if (!value) {
1970 kvfree(key);
1971 return -ENOMEM;
1972 }
1973
1974 for (cp = 0; cp < max_count; cp++) {
1975 err = -EFAULT;
1976 if (copy_from_user(key, keys + cp * map->key_size,
1977 map->key_size) ||
1978 copy_from_user(value, values + cp * value_size, value_size))
1979 break;
1980
1981 err = bpf_map_update_value(map, map_file, key, value,
1982 attr->batch.elem_flags);
1983
1984 if (err)
1985 break;
1986 cond_resched();
1987 }
1988
1989 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1990 err = -EFAULT;
1991
1992 kvfree(value);
1993 kvfree(key);
1994
1995 return err;
1996 }
1997
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1998 int generic_map_lookup_batch(struct bpf_map *map,
1999 const union bpf_attr *attr,
2000 union bpf_attr __user *uattr)
2001 {
2002 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
2003 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
2004 void __user *values = u64_to_user_ptr(attr->batch.values);
2005 void __user *keys = u64_to_user_ptr(attr->batch.keys);
2006 void *buf, *buf_prevkey, *prev_key, *key, *value;
2007 u32 value_size, cp, max_count;
2008 int err;
2009
2010 if (attr->batch.elem_flags & ~BPF_F_LOCK)
2011 return -EINVAL;
2012
2013 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
2014 !btf_record_has_field(map->record, BPF_SPIN_LOCK))
2015 return -EINVAL;
2016
2017 value_size = bpf_map_value_size(map);
2018
2019 max_count = attr->batch.count;
2020 if (!max_count)
2021 return 0;
2022
2023 if (put_user(0, &uattr->batch.count))
2024 return -EFAULT;
2025
2026 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2027 if (!buf_prevkey)
2028 return -ENOMEM;
2029
2030 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2031 if (!buf) {
2032 kvfree(buf_prevkey);
2033 return -ENOMEM;
2034 }
2035
2036 err = -EFAULT;
2037 prev_key = NULL;
2038 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2039 goto free_buf;
2040 key = buf;
2041 value = key + map->key_size;
2042 if (ubatch)
2043 prev_key = buf_prevkey;
2044
2045 for (cp = 0; cp < max_count;) {
2046 rcu_read_lock();
2047 err = map->ops->map_get_next_key(map, prev_key, key);
2048 rcu_read_unlock();
2049 if (err)
2050 break;
2051 err = bpf_map_copy_value(map, key, value,
2052 attr->batch.elem_flags);
2053
2054 if (err == -ENOENT)
2055 goto next_key;
2056
2057 if (err)
2058 goto free_buf;
2059
2060 if (copy_to_user(keys + cp * map->key_size, key,
2061 map->key_size)) {
2062 err = -EFAULT;
2063 goto free_buf;
2064 }
2065 if (copy_to_user(values + cp * value_size, value, value_size)) {
2066 err = -EFAULT;
2067 goto free_buf;
2068 }
2069
2070 cp++;
2071 next_key:
2072 if (!prev_key)
2073 prev_key = buf_prevkey;
2074
2075 swap(prev_key, key);
2076 cond_resched();
2077 }
2078
2079 if (err == -EFAULT)
2080 goto free_buf;
2081
2082 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2083 (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2084 err = -EFAULT;
2085
2086 free_buf:
2087 kvfree(buf_prevkey);
2088 kvfree(buf);
2089 return err;
2090 }
2091
2092 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2093
map_lookup_and_delete_elem(union bpf_attr * attr)2094 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2095 {
2096 void __user *ukey = u64_to_user_ptr(attr->key);
2097 void __user *uvalue = u64_to_user_ptr(attr->value);
2098 struct bpf_map *map;
2099 void *key, *value;
2100 u32 value_size;
2101 int err;
2102
2103 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2104 return -EINVAL;
2105
2106 if (attr->flags & ~BPF_F_LOCK)
2107 return -EINVAL;
2108
2109 CLASS(fd, f)(attr->map_fd);
2110 map = __bpf_map_get(f);
2111 if (IS_ERR(map))
2112 return PTR_ERR(map);
2113 bpf_map_write_active_inc(map);
2114 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2115 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2116 err = -EPERM;
2117 goto err_put;
2118 }
2119
2120 if (attr->flags &&
2121 (map->map_type == BPF_MAP_TYPE_QUEUE ||
2122 map->map_type == BPF_MAP_TYPE_STACK)) {
2123 err = -EINVAL;
2124 goto err_put;
2125 }
2126
2127 if ((attr->flags & BPF_F_LOCK) &&
2128 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2129 err = -EINVAL;
2130 goto err_put;
2131 }
2132
2133 key = __bpf_copy_key(ukey, map->key_size);
2134 if (IS_ERR(key)) {
2135 err = PTR_ERR(key);
2136 goto err_put;
2137 }
2138
2139 value_size = bpf_map_value_size(map);
2140
2141 err = -ENOMEM;
2142 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2143 if (!value)
2144 goto free_key;
2145
2146 err = -ENOTSUPP;
2147 if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2148 map->map_type == BPF_MAP_TYPE_STACK) {
2149 err = map->ops->map_pop_elem(map, value);
2150 } else if (map->map_type == BPF_MAP_TYPE_HASH ||
2151 map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2152 map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2153 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
2154 if (!bpf_map_is_offloaded(map)) {
2155 bpf_disable_instrumentation();
2156 rcu_read_lock();
2157 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2158 rcu_read_unlock();
2159 bpf_enable_instrumentation();
2160 }
2161 }
2162
2163 if (err)
2164 goto free_value;
2165
2166 if (copy_to_user(uvalue, value, value_size) != 0) {
2167 err = -EFAULT;
2168 goto free_value;
2169 }
2170
2171 err = 0;
2172
2173 free_value:
2174 kvfree(value);
2175 free_key:
2176 kvfree(key);
2177 err_put:
2178 bpf_map_write_active_dec(map);
2179 return err;
2180 }
2181
2182 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2183
map_freeze(const union bpf_attr * attr)2184 static int map_freeze(const union bpf_attr *attr)
2185 {
2186 int err = 0;
2187 struct bpf_map *map;
2188
2189 if (CHECK_ATTR(BPF_MAP_FREEZE))
2190 return -EINVAL;
2191
2192 CLASS(fd, f)(attr->map_fd);
2193 map = __bpf_map_get(f);
2194 if (IS_ERR(map))
2195 return PTR_ERR(map);
2196
2197 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2198 return -ENOTSUPP;
2199
2200 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2201 return -EPERM;
2202
2203 mutex_lock(&map->freeze_mutex);
2204 if (bpf_map_write_active(map)) {
2205 err = -EBUSY;
2206 goto err_put;
2207 }
2208 if (READ_ONCE(map->frozen)) {
2209 err = -EBUSY;
2210 goto err_put;
2211 }
2212
2213 WRITE_ONCE(map->frozen, true);
2214 err_put:
2215 mutex_unlock(&map->freeze_mutex);
2216 return err;
2217 }
2218
2219 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2220 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2221 [_id] = & _name ## _prog_ops,
2222 #define BPF_MAP_TYPE(_id, _ops)
2223 #define BPF_LINK_TYPE(_id, _name)
2224 #include <linux/bpf_types.h>
2225 #undef BPF_PROG_TYPE
2226 #undef BPF_MAP_TYPE
2227 #undef BPF_LINK_TYPE
2228 };
2229
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2230 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2231 {
2232 const struct bpf_prog_ops *ops;
2233
2234 if (type >= ARRAY_SIZE(bpf_prog_types))
2235 return -EINVAL;
2236 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2237 ops = bpf_prog_types[type];
2238 if (!ops)
2239 return -EINVAL;
2240
2241 if (!bpf_prog_is_offloaded(prog->aux))
2242 prog->aux->ops = ops;
2243 else
2244 prog->aux->ops = &bpf_offload_prog_ops;
2245 prog->type = type;
2246 return 0;
2247 }
2248
2249 enum bpf_audit {
2250 BPF_AUDIT_LOAD,
2251 BPF_AUDIT_UNLOAD,
2252 BPF_AUDIT_MAX,
2253 };
2254
2255 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2256 [BPF_AUDIT_LOAD] = "LOAD",
2257 [BPF_AUDIT_UNLOAD] = "UNLOAD",
2258 };
2259
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2260 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2261 {
2262 struct audit_context *ctx = NULL;
2263 struct audit_buffer *ab;
2264
2265 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2266 return;
2267 if (audit_enabled == AUDIT_OFF)
2268 return;
2269 if (!in_irq() && !irqs_disabled())
2270 ctx = audit_context();
2271 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2272 if (unlikely(!ab))
2273 return;
2274 audit_log_format(ab, "prog-id=%u op=%s",
2275 prog->aux->id, bpf_audit_str[op]);
2276 audit_log_end(ab);
2277 }
2278
bpf_prog_alloc_id(struct bpf_prog * prog)2279 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2280 {
2281 int id;
2282
2283 idr_preload(GFP_KERNEL);
2284 spin_lock_bh(&prog_idr_lock);
2285 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2286 if (id > 0)
2287 prog->aux->id = id;
2288 spin_unlock_bh(&prog_idr_lock);
2289 idr_preload_end();
2290
2291 /* id is in [1, INT_MAX) */
2292 if (WARN_ON_ONCE(!id))
2293 return -ENOSPC;
2294
2295 return id > 0 ? 0 : id;
2296 }
2297
bpf_prog_free_id(struct bpf_prog * prog)2298 void bpf_prog_free_id(struct bpf_prog *prog)
2299 {
2300 unsigned long flags;
2301
2302 /* cBPF to eBPF migrations are currently not in the idr store.
2303 * Offloaded programs are removed from the store when their device
2304 * disappears - even if someone grabs an fd to them they are unusable,
2305 * simply waiting for refcnt to drop to be freed.
2306 */
2307 if (!prog->aux->id)
2308 return;
2309
2310 spin_lock_irqsave(&prog_idr_lock, flags);
2311 idr_remove(&prog_idr, prog->aux->id);
2312 prog->aux->id = 0;
2313 spin_unlock_irqrestore(&prog_idr_lock, flags);
2314 }
2315
__bpf_prog_put_rcu(struct rcu_head * rcu)2316 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2317 {
2318 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2319
2320 kvfree(aux->func_info);
2321 kfree(aux->func_info_aux);
2322 free_uid(aux->user);
2323 security_bpf_prog_free(aux->prog);
2324 bpf_prog_free(aux->prog);
2325 }
2326
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2327 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2328 {
2329 bpf_prog_kallsyms_del_all(prog);
2330 btf_put(prog->aux->btf);
2331 module_put(prog->aux->mod);
2332 kvfree(prog->aux->jited_linfo);
2333 kvfree(prog->aux->linfo);
2334 kfree(prog->aux->kfunc_tab);
2335 kfree(prog->aux->ctx_arg_info);
2336 if (prog->aux->attach_btf)
2337 btf_put(prog->aux->attach_btf);
2338
2339 if (deferred) {
2340 if (prog->sleepable)
2341 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2342 else
2343 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2344 } else {
2345 __bpf_prog_put_rcu(&prog->aux->rcu);
2346 }
2347 }
2348
bpf_prog_put_deferred(struct work_struct * work)2349 static void bpf_prog_put_deferred(struct work_struct *work)
2350 {
2351 struct bpf_prog_aux *aux;
2352 struct bpf_prog *prog;
2353
2354 aux = container_of(work, struct bpf_prog_aux, work);
2355 prog = aux->prog;
2356 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2357 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2358 bpf_prog_free_id(prog);
2359 __bpf_prog_put_noref(prog, true);
2360 }
2361
__bpf_prog_put(struct bpf_prog * prog)2362 static void __bpf_prog_put(struct bpf_prog *prog)
2363 {
2364 struct bpf_prog_aux *aux = prog->aux;
2365
2366 if (atomic64_dec_and_test(&aux->refcnt)) {
2367 if (in_irq() || irqs_disabled()) {
2368 INIT_WORK(&aux->work, bpf_prog_put_deferred);
2369 schedule_work(&aux->work);
2370 } else {
2371 bpf_prog_put_deferred(&aux->work);
2372 }
2373 }
2374 }
2375
bpf_prog_put(struct bpf_prog * prog)2376 void bpf_prog_put(struct bpf_prog *prog)
2377 {
2378 __bpf_prog_put(prog);
2379 }
2380 EXPORT_SYMBOL_GPL(bpf_prog_put);
2381
bpf_prog_release(struct inode * inode,struct file * filp)2382 static int bpf_prog_release(struct inode *inode, struct file *filp)
2383 {
2384 struct bpf_prog *prog = filp->private_data;
2385
2386 bpf_prog_put(prog);
2387 return 0;
2388 }
2389
2390 struct bpf_prog_kstats {
2391 u64 nsecs;
2392 u64 cnt;
2393 u64 misses;
2394 };
2395
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2396 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2397 {
2398 struct bpf_prog_stats *stats;
2399 unsigned int flags;
2400
2401 stats = this_cpu_ptr(prog->stats);
2402 flags = u64_stats_update_begin_irqsave(&stats->syncp);
2403 u64_stats_inc(&stats->misses);
2404 u64_stats_update_end_irqrestore(&stats->syncp, flags);
2405 }
2406
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2407 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2408 struct bpf_prog_kstats *stats)
2409 {
2410 u64 nsecs = 0, cnt = 0, misses = 0;
2411 int cpu;
2412
2413 for_each_possible_cpu(cpu) {
2414 const struct bpf_prog_stats *st;
2415 unsigned int start;
2416 u64 tnsecs, tcnt, tmisses;
2417
2418 st = per_cpu_ptr(prog->stats, cpu);
2419 do {
2420 start = u64_stats_fetch_begin(&st->syncp);
2421 tnsecs = u64_stats_read(&st->nsecs);
2422 tcnt = u64_stats_read(&st->cnt);
2423 tmisses = u64_stats_read(&st->misses);
2424 } while (u64_stats_fetch_retry(&st->syncp, start));
2425 nsecs += tnsecs;
2426 cnt += tcnt;
2427 misses += tmisses;
2428 }
2429 stats->nsecs = nsecs;
2430 stats->cnt = cnt;
2431 stats->misses = misses;
2432 }
2433
2434 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2435 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2436 {
2437 const struct bpf_prog *prog = filp->private_data;
2438 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2439 struct bpf_prog_kstats stats;
2440
2441 bpf_prog_get_stats(prog, &stats);
2442 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2443 seq_printf(m,
2444 "prog_type:\t%u\n"
2445 "prog_jited:\t%u\n"
2446 "prog_tag:\t%s\n"
2447 "memlock:\t%llu\n"
2448 "prog_id:\t%u\n"
2449 "run_time_ns:\t%llu\n"
2450 "run_cnt:\t%llu\n"
2451 "recursion_misses:\t%llu\n"
2452 "verified_insns:\t%u\n",
2453 prog->type,
2454 prog->jited,
2455 prog_tag,
2456 prog->pages * 1ULL << PAGE_SHIFT,
2457 prog->aux->id,
2458 stats.nsecs,
2459 stats.cnt,
2460 stats.misses,
2461 prog->aux->verified_insns);
2462 }
2463 #endif
2464
2465 const struct file_operations bpf_prog_fops = {
2466 #ifdef CONFIG_PROC_FS
2467 .show_fdinfo = bpf_prog_show_fdinfo,
2468 #endif
2469 .release = bpf_prog_release,
2470 .read = bpf_dummy_read,
2471 .write = bpf_dummy_write,
2472 };
2473
bpf_prog_new_fd(struct bpf_prog * prog)2474 int bpf_prog_new_fd(struct bpf_prog *prog)
2475 {
2476 int ret;
2477
2478 ret = security_bpf_prog(prog);
2479 if (ret < 0)
2480 return ret;
2481
2482 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2483 O_RDWR | O_CLOEXEC);
2484 }
2485
bpf_prog_add(struct bpf_prog * prog,int i)2486 void bpf_prog_add(struct bpf_prog *prog, int i)
2487 {
2488 atomic64_add(i, &prog->aux->refcnt);
2489 }
2490 EXPORT_SYMBOL_GPL(bpf_prog_add);
2491
bpf_prog_sub(struct bpf_prog * prog,int i)2492 void bpf_prog_sub(struct bpf_prog *prog, int i)
2493 {
2494 /* Only to be used for undoing previous bpf_prog_add() in some
2495 * error path. We still know that another entity in our call
2496 * path holds a reference to the program, thus atomic_sub() can
2497 * be safely used in such cases!
2498 */
2499 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2500 }
2501 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2502
bpf_prog_inc(struct bpf_prog * prog)2503 void bpf_prog_inc(struct bpf_prog *prog)
2504 {
2505 atomic64_inc(&prog->aux->refcnt);
2506 }
2507 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2508
2509 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2510 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2511 {
2512 int refold;
2513
2514 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2515
2516 if (!refold)
2517 return ERR_PTR(-ENOENT);
2518
2519 return prog;
2520 }
2521 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2522
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2523 bool bpf_prog_get_ok(struct bpf_prog *prog,
2524 enum bpf_prog_type *attach_type, bool attach_drv)
2525 {
2526 /* not an attachment, just a refcount inc, always allow */
2527 if (!attach_type)
2528 return true;
2529
2530 if (prog->type != *attach_type)
2531 return false;
2532 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2533 return false;
2534
2535 return true;
2536 }
2537
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2538 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2539 bool attach_drv)
2540 {
2541 CLASS(fd, f)(ufd);
2542 struct bpf_prog *prog;
2543
2544 if (fd_empty(f))
2545 return ERR_PTR(-EBADF);
2546 if (fd_file(f)->f_op != &bpf_prog_fops)
2547 return ERR_PTR(-EINVAL);
2548
2549 prog = fd_file(f)->private_data;
2550 if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2551 return ERR_PTR(-EINVAL);
2552
2553 bpf_prog_inc(prog);
2554 return prog;
2555 }
2556
bpf_prog_get(u32 ufd)2557 struct bpf_prog *bpf_prog_get(u32 ufd)
2558 {
2559 return __bpf_prog_get(ufd, NULL, false);
2560 }
2561
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2562 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2563 bool attach_drv)
2564 {
2565 return __bpf_prog_get(ufd, &type, attach_drv);
2566 }
2567 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2568
2569 /* Initially all BPF programs could be loaded w/o specifying
2570 * expected_attach_type. Later for some of them specifying expected_attach_type
2571 * at load time became required so that program could be validated properly.
2572 * Programs of types that are allowed to be loaded both w/ and w/o (for
2573 * backward compatibility) expected_attach_type, should have the default attach
2574 * type assigned to expected_attach_type for the latter case, so that it can be
2575 * validated later at attach time.
2576 *
2577 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2578 * prog type requires it but has some attach types that have to be backward
2579 * compatible.
2580 */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2581 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2582 {
2583 switch (attr->prog_type) {
2584 case BPF_PROG_TYPE_CGROUP_SOCK:
2585 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2586 * exist so checking for non-zero is the way to go here.
2587 */
2588 if (!attr->expected_attach_type)
2589 attr->expected_attach_type =
2590 BPF_CGROUP_INET_SOCK_CREATE;
2591 break;
2592 case BPF_PROG_TYPE_SK_REUSEPORT:
2593 if (!attr->expected_attach_type)
2594 attr->expected_attach_type =
2595 BPF_SK_REUSEPORT_SELECT;
2596 break;
2597 }
2598 }
2599
2600 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)2601 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2602 enum bpf_attach_type expected_attach_type,
2603 struct btf *attach_btf, u32 btf_id,
2604 struct bpf_prog *dst_prog)
2605 {
2606 if (btf_id) {
2607 if (btf_id > BTF_MAX_TYPE)
2608 return -EINVAL;
2609
2610 if (!attach_btf && !dst_prog)
2611 return -EINVAL;
2612
2613 switch (prog_type) {
2614 case BPF_PROG_TYPE_TRACING:
2615 case BPF_PROG_TYPE_LSM:
2616 case BPF_PROG_TYPE_STRUCT_OPS:
2617 case BPF_PROG_TYPE_EXT:
2618 break;
2619 default:
2620 return -EINVAL;
2621 }
2622 }
2623
2624 if (attach_btf && (!btf_id || dst_prog))
2625 return -EINVAL;
2626
2627 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2628 prog_type != BPF_PROG_TYPE_EXT)
2629 return -EINVAL;
2630
2631 switch (prog_type) {
2632 case BPF_PROG_TYPE_CGROUP_SOCK:
2633 switch (expected_attach_type) {
2634 case BPF_CGROUP_INET_SOCK_CREATE:
2635 case BPF_CGROUP_INET_SOCK_RELEASE:
2636 case BPF_CGROUP_INET4_POST_BIND:
2637 case BPF_CGROUP_INET6_POST_BIND:
2638 return 0;
2639 default:
2640 return -EINVAL;
2641 }
2642 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2643 switch (expected_attach_type) {
2644 case BPF_CGROUP_INET4_BIND:
2645 case BPF_CGROUP_INET6_BIND:
2646 case BPF_CGROUP_INET4_CONNECT:
2647 case BPF_CGROUP_INET6_CONNECT:
2648 case BPF_CGROUP_UNIX_CONNECT:
2649 case BPF_CGROUP_INET4_GETPEERNAME:
2650 case BPF_CGROUP_INET6_GETPEERNAME:
2651 case BPF_CGROUP_UNIX_GETPEERNAME:
2652 case BPF_CGROUP_INET4_GETSOCKNAME:
2653 case BPF_CGROUP_INET6_GETSOCKNAME:
2654 case BPF_CGROUP_UNIX_GETSOCKNAME:
2655 case BPF_CGROUP_UDP4_SENDMSG:
2656 case BPF_CGROUP_UDP6_SENDMSG:
2657 case BPF_CGROUP_UNIX_SENDMSG:
2658 case BPF_CGROUP_UDP4_RECVMSG:
2659 case BPF_CGROUP_UDP6_RECVMSG:
2660 case BPF_CGROUP_UNIX_RECVMSG:
2661 return 0;
2662 default:
2663 return -EINVAL;
2664 }
2665 case BPF_PROG_TYPE_CGROUP_SKB:
2666 switch (expected_attach_type) {
2667 case BPF_CGROUP_INET_INGRESS:
2668 case BPF_CGROUP_INET_EGRESS:
2669 return 0;
2670 default:
2671 return -EINVAL;
2672 }
2673 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2674 switch (expected_attach_type) {
2675 case BPF_CGROUP_SETSOCKOPT:
2676 case BPF_CGROUP_GETSOCKOPT:
2677 return 0;
2678 default:
2679 return -EINVAL;
2680 }
2681 case BPF_PROG_TYPE_SK_LOOKUP:
2682 if (expected_attach_type == BPF_SK_LOOKUP)
2683 return 0;
2684 return -EINVAL;
2685 case BPF_PROG_TYPE_SK_REUSEPORT:
2686 switch (expected_attach_type) {
2687 case BPF_SK_REUSEPORT_SELECT:
2688 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2689 return 0;
2690 default:
2691 return -EINVAL;
2692 }
2693 case BPF_PROG_TYPE_NETFILTER:
2694 if (expected_attach_type == BPF_NETFILTER)
2695 return 0;
2696 return -EINVAL;
2697 case BPF_PROG_TYPE_SYSCALL:
2698 case BPF_PROG_TYPE_EXT:
2699 if (expected_attach_type)
2700 return -EINVAL;
2701 fallthrough;
2702 default:
2703 return 0;
2704 }
2705 }
2706
is_net_admin_prog_type(enum bpf_prog_type prog_type)2707 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2708 {
2709 switch (prog_type) {
2710 case BPF_PROG_TYPE_SCHED_CLS:
2711 case BPF_PROG_TYPE_SCHED_ACT:
2712 case BPF_PROG_TYPE_XDP:
2713 case BPF_PROG_TYPE_LWT_IN:
2714 case BPF_PROG_TYPE_LWT_OUT:
2715 case BPF_PROG_TYPE_LWT_XMIT:
2716 case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2717 case BPF_PROG_TYPE_SK_SKB:
2718 case BPF_PROG_TYPE_SK_MSG:
2719 case BPF_PROG_TYPE_FLOW_DISSECTOR:
2720 case BPF_PROG_TYPE_CGROUP_DEVICE:
2721 case BPF_PROG_TYPE_CGROUP_SOCK:
2722 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2723 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2724 case BPF_PROG_TYPE_CGROUP_SYSCTL:
2725 case BPF_PROG_TYPE_SOCK_OPS:
2726 case BPF_PROG_TYPE_EXT: /* extends any prog */
2727 case BPF_PROG_TYPE_NETFILTER:
2728 return true;
2729 case BPF_PROG_TYPE_CGROUP_SKB:
2730 /* always unpriv */
2731 case BPF_PROG_TYPE_SK_REUSEPORT:
2732 /* equivalent to SOCKET_FILTER. need CAP_BPF only */
2733 default:
2734 return false;
2735 }
2736 }
2737
is_perfmon_prog_type(enum bpf_prog_type prog_type)2738 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2739 {
2740 switch (prog_type) {
2741 case BPF_PROG_TYPE_KPROBE:
2742 case BPF_PROG_TYPE_TRACEPOINT:
2743 case BPF_PROG_TYPE_PERF_EVENT:
2744 case BPF_PROG_TYPE_RAW_TRACEPOINT:
2745 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2746 case BPF_PROG_TYPE_TRACING:
2747 case BPF_PROG_TYPE_LSM:
2748 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2749 case BPF_PROG_TYPE_EXT: /* extends any prog */
2750 return true;
2751 default:
2752 return false;
2753 }
2754 }
2755
2756 /* last field in 'union bpf_attr' used by this command */
2757 #define BPF_PROG_LOAD_LAST_FIELD fd_array_cnt
2758
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2759 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2760 {
2761 enum bpf_prog_type type = attr->prog_type;
2762 struct bpf_prog *prog, *dst_prog = NULL;
2763 struct btf *attach_btf = NULL;
2764 struct bpf_token *token = NULL;
2765 bool bpf_cap;
2766 int err;
2767 char license[128];
2768
2769 if (CHECK_ATTR(BPF_PROG_LOAD))
2770 return -EINVAL;
2771
2772 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2773 BPF_F_ANY_ALIGNMENT |
2774 BPF_F_TEST_STATE_FREQ |
2775 BPF_F_SLEEPABLE |
2776 BPF_F_TEST_RND_HI32 |
2777 BPF_F_XDP_HAS_FRAGS |
2778 BPF_F_XDP_DEV_BOUND_ONLY |
2779 BPF_F_TEST_REG_INVARIANTS |
2780 BPF_F_TOKEN_FD))
2781 return -EINVAL;
2782
2783 bpf_prog_load_fixup_attach_type(attr);
2784
2785 if (attr->prog_flags & BPF_F_TOKEN_FD) {
2786 token = bpf_token_get_from_fd(attr->prog_token_fd);
2787 if (IS_ERR(token))
2788 return PTR_ERR(token);
2789 /* if current token doesn't grant prog loading permissions,
2790 * then we can't use this token, so ignore it and rely on
2791 * system-wide capabilities checks
2792 */
2793 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2794 !bpf_token_allow_prog_type(token, attr->prog_type,
2795 attr->expected_attach_type)) {
2796 bpf_token_put(token);
2797 token = NULL;
2798 }
2799 }
2800
2801 bpf_cap = bpf_token_capable(token, CAP_BPF);
2802 err = -EPERM;
2803
2804 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2805 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2806 !bpf_cap)
2807 goto put_token;
2808
2809 /* Intent here is for unprivileged_bpf_disabled to block BPF program
2810 * creation for unprivileged users; other actions depend
2811 * on fd availability and access to bpffs, so are dependent on
2812 * object creation success. Even with unprivileged BPF disabled,
2813 * capability checks are still carried out for these
2814 * and other operations.
2815 */
2816 if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2817 goto put_token;
2818
2819 if (attr->insn_cnt == 0 ||
2820 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2821 err = -E2BIG;
2822 goto put_token;
2823 }
2824 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2825 type != BPF_PROG_TYPE_CGROUP_SKB &&
2826 !bpf_cap)
2827 goto put_token;
2828
2829 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2830 goto put_token;
2831 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2832 goto put_token;
2833
2834 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2835 * or btf, we need to check which one it is
2836 */
2837 if (attr->attach_prog_fd) {
2838 dst_prog = bpf_prog_get(attr->attach_prog_fd);
2839 if (IS_ERR(dst_prog)) {
2840 dst_prog = NULL;
2841 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2842 if (IS_ERR(attach_btf)) {
2843 err = -EINVAL;
2844 goto put_token;
2845 }
2846 if (!btf_is_kernel(attach_btf)) {
2847 /* attaching through specifying bpf_prog's BTF
2848 * objects directly might be supported eventually
2849 */
2850 btf_put(attach_btf);
2851 err = -ENOTSUPP;
2852 goto put_token;
2853 }
2854 }
2855 } else if (attr->attach_btf_id) {
2856 /* fall back to vmlinux BTF, if BTF type ID is specified */
2857 attach_btf = bpf_get_btf_vmlinux();
2858 if (IS_ERR(attach_btf)) {
2859 err = PTR_ERR(attach_btf);
2860 goto put_token;
2861 }
2862 if (!attach_btf) {
2863 err = -EINVAL;
2864 goto put_token;
2865 }
2866 btf_get(attach_btf);
2867 }
2868
2869 if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2870 attach_btf, attr->attach_btf_id,
2871 dst_prog)) {
2872 if (dst_prog)
2873 bpf_prog_put(dst_prog);
2874 if (attach_btf)
2875 btf_put(attach_btf);
2876 err = -EINVAL;
2877 goto put_token;
2878 }
2879
2880 /* plain bpf_prog allocation */
2881 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2882 if (!prog) {
2883 if (dst_prog)
2884 bpf_prog_put(dst_prog);
2885 if (attach_btf)
2886 btf_put(attach_btf);
2887 err = -EINVAL;
2888 goto put_token;
2889 }
2890
2891 prog->expected_attach_type = attr->expected_attach_type;
2892 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
2893 prog->aux->attach_btf = attach_btf;
2894 prog->aux->attach_btf_id = attr->attach_btf_id;
2895 prog->aux->dst_prog = dst_prog;
2896 prog->aux->dev_bound = !!attr->prog_ifindex;
2897 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
2898
2899 /* move token into prog->aux, reuse taken refcnt */
2900 prog->aux->token = token;
2901 token = NULL;
2902
2903 prog->aux->user = get_current_user();
2904 prog->len = attr->insn_cnt;
2905
2906 err = -EFAULT;
2907 if (copy_from_bpfptr(prog->insns,
2908 make_bpfptr(attr->insns, uattr.is_kernel),
2909 bpf_prog_insn_size(prog)) != 0)
2910 goto free_prog;
2911 /* copy eBPF program license from user space */
2912 if (strncpy_from_bpfptr(license,
2913 make_bpfptr(attr->license, uattr.is_kernel),
2914 sizeof(license) - 1) < 0)
2915 goto free_prog;
2916 license[sizeof(license) - 1] = 0;
2917
2918 /* eBPF programs must be GPL compatible to use GPL-ed functions */
2919 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
2920
2921 prog->orig_prog = NULL;
2922 prog->jited = 0;
2923
2924 atomic64_set(&prog->aux->refcnt, 1);
2925
2926 if (bpf_prog_is_dev_bound(prog->aux)) {
2927 err = bpf_prog_dev_bound_init(prog, attr);
2928 if (err)
2929 goto free_prog;
2930 }
2931
2932 if (type == BPF_PROG_TYPE_EXT && dst_prog &&
2933 bpf_prog_is_dev_bound(dst_prog->aux)) {
2934 err = bpf_prog_dev_bound_inherit(prog, dst_prog);
2935 if (err)
2936 goto free_prog;
2937 }
2938
2939 /*
2940 * Bookkeeping for managing the program attachment chain.
2941 *
2942 * It might be tempting to set attach_tracing_prog flag at the attachment
2943 * time, but this will not prevent from loading bunch of tracing prog
2944 * first, then attach them one to another.
2945 *
2946 * The flag attach_tracing_prog is set for the whole program lifecycle, and
2947 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
2948 * programs cannot change attachment target.
2949 */
2950 if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
2951 dst_prog->type == BPF_PROG_TYPE_TRACING) {
2952 prog->aux->attach_tracing_prog = true;
2953 }
2954
2955 /* find program type: socket_filter vs tracing_filter */
2956 err = find_prog_type(type, prog);
2957 if (err < 0)
2958 goto free_prog;
2959
2960 prog->aux->load_time = ktime_get_boottime_ns();
2961 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2962 sizeof(attr->prog_name));
2963 if (err < 0)
2964 goto free_prog;
2965
2966 err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel);
2967 if (err)
2968 goto free_prog_sec;
2969
2970 /* run eBPF verifier */
2971 err = bpf_check(&prog, attr, uattr, uattr_size);
2972 if (err < 0)
2973 goto free_used_maps;
2974
2975 prog = bpf_prog_select_runtime(prog, &err);
2976 if (err < 0)
2977 goto free_used_maps;
2978
2979 err = bpf_prog_alloc_id(prog);
2980 if (err)
2981 goto free_used_maps;
2982
2983 /* Upon success of bpf_prog_alloc_id(), the BPF prog is
2984 * effectively publicly exposed. However, retrieving via
2985 * bpf_prog_get_fd_by_id() will take another reference,
2986 * therefore it cannot be gone underneath us.
2987 *
2988 * Only for the time /after/ successful bpf_prog_new_fd()
2989 * and before returning to userspace, we might just hold
2990 * one reference and any parallel close on that fd could
2991 * rip everything out. Hence, below notifications must
2992 * happen before bpf_prog_new_fd().
2993 *
2994 * Also, any failure handling from this point onwards must
2995 * be using bpf_prog_put() given the program is exposed.
2996 */
2997 bpf_prog_kallsyms_add(prog);
2998 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2999 bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3000
3001 err = bpf_prog_new_fd(prog);
3002 if (err < 0)
3003 bpf_prog_put(prog);
3004 return err;
3005
3006 free_used_maps:
3007 /* In case we have subprogs, we need to wait for a grace
3008 * period before we can tear down JIT memory since symbols
3009 * are already exposed under kallsyms.
3010 */
3011 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3012 return err;
3013
3014 free_prog_sec:
3015 security_bpf_prog_free(prog);
3016 free_prog:
3017 free_uid(prog->aux->user);
3018 if (prog->aux->attach_btf)
3019 btf_put(prog->aux->attach_btf);
3020 bpf_prog_free(prog);
3021 put_token:
3022 bpf_token_put(token);
3023 return err;
3024 }
3025
3026 #define BPF_OBJ_LAST_FIELD path_fd
3027
bpf_obj_pin(const union bpf_attr * attr)3028 static int bpf_obj_pin(const union bpf_attr *attr)
3029 {
3030 int path_fd;
3031
3032 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3033 return -EINVAL;
3034
3035 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3036 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3037 return -EINVAL;
3038
3039 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3040 return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3041 u64_to_user_ptr(attr->pathname));
3042 }
3043
bpf_obj_get(const union bpf_attr * attr)3044 static int bpf_obj_get(const union bpf_attr *attr)
3045 {
3046 int path_fd;
3047
3048 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3049 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3050 return -EINVAL;
3051
3052 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3053 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3054 return -EINVAL;
3055
3056 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3057 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3058 attr->file_flags);
3059 }
3060
3061 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3062 * "sleepable" semantics, which normally would mean that BPF link's attach
3063 * hook can dereference link or link's underlying program for some time after
3064 * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3065 * BPF program itself can be non-sleepable, yet, because it's transitively
3066 * reachable through BPF link, its freeing has to be delayed until after RCU
3067 * Tasks Trace GP.
3068 */
bpf_link_init_sleepable(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,bool sleepable)3069 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3070 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3071 bool sleepable)
3072 {
3073 WARN_ON(ops->dealloc && ops->dealloc_deferred);
3074 atomic64_set(&link->refcnt, 1);
3075 link->type = type;
3076 link->sleepable = sleepable;
3077 link->id = 0;
3078 link->ops = ops;
3079 link->prog = prog;
3080 }
3081
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)3082 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3083 const struct bpf_link_ops *ops, struct bpf_prog *prog)
3084 {
3085 bpf_link_init_sleepable(link, type, ops, prog, false);
3086 }
3087
bpf_link_free_id(int id)3088 static void bpf_link_free_id(int id)
3089 {
3090 if (!id)
3091 return;
3092
3093 spin_lock_bh(&link_idr_lock);
3094 idr_remove(&link_idr, id);
3095 spin_unlock_bh(&link_idr_lock);
3096 }
3097
3098 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3099 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3100 * anon_inode's release() call. This helper marks bpf_link as
3101 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3102 * is not decremented, it's the responsibility of a calling code that failed
3103 * to complete bpf_link initialization.
3104 * This helper eventually calls link's dealloc callback, but does not call
3105 * link's release callback.
3106 */
bpf_link_cleanup(struct bpf_link_primer * primer)3107 void bpf_link_cleanup(struct bpf_link_primer *primer)
3108 {
3109 primer->link->prog = NULL;
3110 bpf_link_free_id(primer->id);
3111 fput(primer->file);
3112 put_unused_fd(primer->fd);
3113 }
3114
bpf_link_inc(struct bpf_link * link)3115 void bpf_link_inc(struct bpf_link *link)
3116 {
3117 atomic64_inc(&link->refcnt);
3118 }
3119
bpf_link_dealloc(struct bpf_link * link)3120 static void bpf_link_dealloc(struct bpf_link *link)
3121 {
3122 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3123 if (link->prog)
3124 bpf_prog_put(link->prog);
3125
3126 /* free bpf_link and its containing memory */
3127 if (link->ops->dealloc_deferred)
3128 link->ops->dealloc_deferred(link);
3129 else
3130 link->ops->dealloc(link);
3131 }
3132
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3133 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3134 {
3135 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3136
3137 bpf_link_dealloc(link);
3138 }
3139
bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head * rcu)3140 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
3141 {
3142 if (rcu_trace_implies_rcu_gp())
3143 bpf_link_defer_dealloc_rcu_gp(rcu);
3144 else
3145 call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
3146 }
3147
3148 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3149 static void bpf_link_free(struct bpf_link *link)
3150 {
3151 const struct bpf_link_ops *ops = link->ops;
3152
3153 bpf_link_free_id(link->id);
3154 /* detach BPF program, clean up used resources */
3155 if (link->prog)
3156 ops->release(link);
3157 if (ops->dealloc_deferred) {
3158 /* Schedule BPF link deallocation, which will only then
3159 * trigger putting BPF program refcount.
3160 * If underlying BPF program is sleepable or BPF link's target
3161 * attach hookpoint is sleepable or otherwise requires RCU GPs
3162 * to ensure link and its underlying BPF program is not
3163 * reachable anymore, we need to first wait for RCU tasks
3164 * trace sync, and then go through "classic" RCU grace period
3165 */
3166 if (link->sleepable || (link->prog && link->prog->sleepable))
3167 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
3168 else
3169 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3170 } else if (ops->dealloc) {
3171 bpf_link_dealloc(link);
3172 }
3173 }
3174
bpf_link_put_deferred(struct work_struct * work)3175 static void bpf_link_put_deferred(struct work_struct *work)
3176 {
3177 struct bpf_link *link = container_of(work, struct bpf_link, work);
3178
3179 bpf_link_free(link);
3180 }
3181
3182 /* bpf_link_put might be called from atomic context. It needs to be called
3183 * from sleepable context in order to acquire sleeping locks during the process.
3184 */
bpf_link_put(struct bpf_link * link)3185 void bpf_link_put(struct bpf_link *link)
3186 {
3187 if (!atomic64_dec_and_test(&link->refcnt))
3188 return;
3189
3190 INIT_WORK(&link->work, bpf_link_put_deferred);
3191 schedule_work(&link->work);
3192 }
3193 EXPORT_SYMBOL(bpf_link_put);
3194
bpf_link_put_direct(struct bpf_link * link)3195 static void bpf_link_put_direct(struct bpf_link *link)
3196 {
3197 if (!atomic64_dec_and_test(&link->refcnt))
3198 return;
3199 bpf_link_free(link);
3200 }
3201
bpf_link_release(struct inode * inode,struct file * filp)3202 static int bpf_link_release(struct inode *inode, struct file *filp)
3203 {
3204 struct bpf_link *link = filp->private_data;
3205
3206 bpf_link_put_direct(link);
3207 return 0;
3208 }
3209
3210 #ifdef CONFIG_PROC_FS
3211 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3212 #define BPF_MAP_TYPE(_id, _ops)
3213 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3214 static const char *bpf_link_type_strs[] = {
3215 [BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3216 #include <linux/bpf_types.h>
3217 };
3218 #undef BPF_PROG_TYPE
3219 #undef BPF_MAP_TYPE
3220 #undef BPF_LINK_TYPE
3221
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3222 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3223 {
3224 const struct bpf_link *link = filp->private_data;
3225 const struct bpf_prog *prog = link->prog;
3226 enum bpf_link_type type = link->type;
3227 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3228
3229 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3230 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3231 } else {
3232 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3233 seq_printf(m, "link_type:\t<%u>\n", type);
3234 }
3235 seq_printf(m, "link_id:\t%u\n", link->id);
3236
3237 if (prog) {
3238 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3239 seq_printf(m,
3240 "prog_tag:\t%s\n"
3241 "prog_id:\t%u\n",
3242 prog_tag,
3243 prog->aux->id);
3244 }
3245 if (link->ops->show_fdinfo)
3246 link->ops->show_fdinfo(link, m);
3247 }
3248 #endif
3249
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3250 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3251 {
3252 struct bpf_link *link = file->private_data;
3253
3254 return link->ops->poll(file, pts);
3255 }
3256
3257 static const struct file_operations bpf_link_fops = {
3258 #ifdef CONFIG_PROC_FS
3259 .show_fdinfo = bpf_link_show_fdinfo,
3260 #endif
3261 .release = bpf_link_release,
3262 .read = bpf_dummy_read,
3263 .write = bpf_dummy_write,
3264 };
3265
3266 static const struct file_operations bpf_link_fops_poll = {
3267 #ifdef CONFIG_PROC_FS
3268 .show_fdinfo = bpf_link_show_fdinfo,
3269 #endif
3270 .release = bpf_link_release,
3271 .read = bpf_dummy_read,
3272 .write = bpf_dummy_write,
3273 .poll = bpf_link_poll,
3274 };
3275
bpf_link_alloc_id(struct bpf_link * link)3276 static int bpf_link_alloc_id(struct bpf_link *link)
3277 {
3278 int id;
3279
3280 idr_preload(GFP_KERNEL);
3281 spin_lock_bh(&link_idr_lock);
3282 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3283 spin_unlock_bh(&link_idr_lock);
3284 idr_preload_end();
3285
3286 return id;
3287 }
3288
3289 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3290 * reserving unused FD and allocating ID from link_idr. This is to be paired
3291 * with bpf_link_settle() to install FD and ID and expose bpf_link to
3292 * user-space, if bpf_link is successfully attached. If not, bpf_link and
3293 * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3294 * transient state is passed around in struct bpf_link_primer.
3295 * This is preferred way to create and initialize bpf_link, especially when
3296 * there are complicated and expensive operations in between creating bpf_link
3297 * itself and attaching it to BPF hook. By using bpf_link_prime() and
3298 * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3299 * expensive (and potentially failing) roll back operations in a rare case
3300 * that file, FD, or ID can't be allocated.
3301 */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3302 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3303 {
3304 struct file *file;
3305 int fd, id;
3306
3307 fd = get_unused_fd_flags(O_CLOEXEC);
3308 if (fd < 0)
3309 return fd;
3310
3311
3312 id = bpf_link_alloc_id(link);
3313 if (id < 0) {
3314 put_unused_fd(fd);
3315 return id;
3316 }
3317
3318 file = anon_inode_getfile("bpf_link",
3319 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3320 link, O_CLOEXEC);
3321 if (IS_ERR(file)) {
3322 bpf_link_free_id(id);
3323 put_unused_fd(fd);
3324 return PTR_ERR(file);
3325 }
3326
3327 primer->link = link;
3328 primer->file = file;
3329 primer->fd = fd;
3330 primer->id = id;
3331 return 0;
3332 }
3333
bpf_link_settle(struct bpf_link_primer * primer)3334 int bpf_link_settle(struct bpf_link_primer *primer)
3335 {
3336 /* make bpf_link fetchable by ID */
3337 spin_lock_bh(&link_idr_lock);
3338 primer->link->id = primer->id;
3339 spin_unlock_bh(&link_idr_lock);
3340 /* make bpf_link fetchable by FD */
3341 fd_install(primer->fd, primer->file);
3342 /* pass through installed FD */
3343 return primer->fd;
3344 }
3345
bpf_link_new_fd(struct bpf_link * link)3346 int bpf_link_new_fd(struct bpf_link *link)
3347 {
3348 return anon_inode_getfd("bpf-link",
3349 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3350 link, O_CLOEXEC);
3351 }
3352
bpf_link_get_from_fd(u32 ufd)3353 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3354 {
3355 CLASS(fd, f)(ufd);
3356 struct bpf_link *link;
3357
3358 if (fd_empty(f))
3359 return ERR_PTR(-EBADF);
3360 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3361 return ERR_PTR(-EINVAL);
3362
3363 link = fd_file(f)->private_data;
3364 bpf_link_inc(link);
3365 return link;
3366 }
3367 EXPORT_SYMBOL(bpf_link_get_from_fd);
3368
bpf_tracing_link_release(struct bpf_link * link)3369 static void bpf_tracing_link_release(struct bpf_link *link)
3370 {
3371 struct bpf_tracing_link *tr_link =
3372 container_of(link, struct bpf_tracing_link, link.link);
3373
3374 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3375 tr_link->trampoline,
3376 tr_link->tgt_prog));
3377
3378 bpf_trampoline_put(tr_link->trampoline);
3379
3380 /* tgt_prog is NULL if target is a kernel function */
3381 if (tr_link->tgt_prog)
3382 bpf_prog_put(tr_link->tgt_prog);
3383 }
3384
bpf_tracing_link_dealloc(struct bpf_link * link)3385 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3386 {
3387 struct bpf_tracing_link *tr_link =
3388 container_of(link, struct bpf_tracing_link, link.link);
3389
3390 kfree(tr_link);
3391 }
3392
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3393 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3394 struct seq_file *seq)
3395 {
3396 struct bpf_tracing_link *tr_link =
3397 container_of(link, struct bpf_tracing_link, link.link);
3398 u32 target_btf_id, target_obj_id;
3399
3400 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3401 &target_obj_id, &target_btf_id);
3402 seq_printf(seq,
3403 "attach_type:\t%d\n"
3404 "target_obj_id:\t%u\n"
3405 "target_btf_id:\t%u\n",
3406 tr_link->attach_type,
3407 target_obj_id,
3408 target_btf_id);
3409 }
3410
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3411 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3412 struct bpf_link_info *info)
3413 {
3414 struct bpf_tracing_link *tr_link =
3415 container_of(link, struct bpf_tracing_link, link.link);
3416
3417 info->tracing.attach_type = tr_link->attach_type;
3418 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3419 &info->tracing.target_obj_id,
3420 &info->tracing.target_btf_id);
3421
3422 return 0;
3423 }
3424
3425 static const struct bpf_link_ops bpf_tracing_link_lops = {
3426 .release = bpf_tracing_link_release,
3427 .dealloc = bpf_tracing_link_dealloc,
3428 .show_fdinfo = bpf_tracing_link_show_fdinfo,
3429 .fill_link_info = bpf_tracing_link_fill_link_info,
3430 };
3431
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)3432 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3433 int tgt_prog_fd,
3434 u32 btf_id,
3435 u64 bpf_cookie)
3436 {
3437 struct bpf_link_primer link_primer;
3438 struct bpf_prog *tgt_prog = NULL;
3439 struct bpf_trampoline *tr = NULL;
3440 struct bpf_tracing_link *link;
3441 u64 key = 0;
3442 int err;
3443
3444 switch (prog->type) {
3445 case BPF_PROG_TYPE_TRACING:
3446 if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3447 prog->expected_attach_type != BPF_TRACE_FEXIT &&
3448 prog->expected_attach_type != BPF_MODIFY_RETURN) {
3449 err = -EINVAL;
3450 goto out_put_prog;
3451 }
3452 break;
3453 case BPF_PROG_TYPE_EXT:
3454 if (prog->expected_attach_type != 0) {
3455 err = -EINVAL;
3456 goto out_put_prog;
3457 }
3458 break;
3459 case BPF_PROG_TYPE_LSM:
3460 if (prog->expected_attach_type != BPF_LSM_MAC) {
3461 err = -EINVAL;
3462 goto out_put_prog;
3463 }
3464 break;
3465 default:
3466 err = -EINVAL;
3467 goto out_put_prog;
3468 }
3469
3470 if (!!tgt_prog_fd != !!btf_id) {
3471 err = -EINVAL;
3472 goto out_put_prog;
3473 }
3474
3475 if (tgt_prog_fd) {
3476 /*
3477 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3478 * part would be changed to implement the same for
3479 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3480 * attach_tracing_prog flag is set.
3481 */
3482 if (prog->type != BPF_PROG_TYPE_EXT) {
3483 err = -EINVAL;
3484 goto out_put_prog;
3485 }
3486
3487 tgt_prog = bpf_prog_get(tgt_prog_fd);
3488 if (IS_ERR(tgt_prog)) {
3489 err = PTR_ERR(tgt_prog);
3490 tgt_prog = NULL;
3491 goto out_put_prog;
3492 }
3493
3494 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3495 }
3496
3497 link = kzalloc(sizeof(*link), GFP_USER);
3498 if (!link) {
3499 err = -ENOMEM;
3500 goto out_put_prog;
3501 }
3502 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3503 &bpf_tracing_link_lops, prog);
3504 link->attach_type = prog->expected_attach_type;
3505 link->link.cookie = bpf_cookie;
3506
3507 mutex_lock(&prog->aux->dst_mutex);
3508
3509 /* There are a few possible cases here:
3510 *
3511 * - if prog->aux->dst_trampoline is set, the program was just loaded
3512 * and not yet attached to anything, so we can use the values stored
3513 * in prog->aux
3514 *
3515 * - if prog->aux->dst_trampoline is NULL, the program has already been
3516 * attached to a target and its initial target was cleared (below)
3517 *
3518 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3519 * target_btf_id using the link_create API.
3520 *
3521 * - if tgt_prog == NULL when this function was called using the old
3522 * raw_tracepoint_open API, and we need a target from prog->aux
3523 *
3524 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3525 * was detached and is going for re-attachment.
3526 *
3527 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3528 * are NULL, then program was already attached and user did not provide
3529 * tgt_prog_fd so we have no way to find out or create trampoline
3530 */
3531 if (!prog->aux->dst_trampoline && !tgt_prog) {
3532 /*
3533 * Allow re-attach for TRACING and LSM programs. If it's
3534 * currently linked, bpf_trampoline_link_prog will fail.
3535 * EXT programs need to specify tgt_prog_fd, so they
3536 * re-attach in separate code path.
3537 */
3538 if (prog->type != BPF_PROG_TYPE_TRACING &&
3539 prog->type != BPF_PROG_TYPE_LSM) {
3540 err = -EINVAL;
3541 goto out_unlock;
3542 }
3543 /* We can allow re-attach only if we have valid attach_btf. */
3544 if (!prog->aux->attach_btf) {
3545 err = -EINVAL;
3546 goto out_unlock;
3547 }
3548 btf_id = prog->aux->attach_btf_id;
3549 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3550 }
3551
3552 if (!prog->aux->dst_trampoline ||
3553 (key && key != prog->aux->dst_trampoline->key)) {
3554 /* If there is no saved target, or the specified target is
3555 * different from the destination specified at load time, we
3556 * need a new trampoline and a check for compatibility
3557 */
3558 struct bpf_attach_target_info tgt_info = {};
3559
3560 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3561 &tgt_info);
3562 if (err)
3563 goto out_unlock;
3564
3565 if (tgt_info.tgt_mod) {
3566 module_put(prog->aux->mod);
3567 prog->aux->mod = tgt_info.tgt_mod;
3568 }
3569
3570 tr = bpf_trampoline_get(key, &tgt_info);
3571 if (!tr) {
3572 err = -ENOMEM;
3573 goto out_unlock;
3574 }
3575 } else {
3576 /* The caller didn't specify a target, or the target was the
3577 * same as the destination supplied during program load. This
3578 * means we can reuse the trampoline and reference from program
3579 * load time, and there is no need to allocate a new one. This
3580 * can only happen once for any program, as the saved values in
3581 * prog->aux are cleared below.
3582 */
3583 tr = prog->aux->dst_trampoline;
3584 tgt_prog = prog->aux->dst_prog;
3585 }
3586
3587 err = bpf_link_prime(&link->link.link, &link_primer);
3588 if (err)
3589 goto out_unlock;
3590
3591 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3592 if (err) {
3593 bpf_link_cleanup(&link_primer);
3594 link = NULL;
3595 goto out_unlock;
3596 }
3597
3598 link->tgt_prog = tgt_prog;
3599 link->trampoline = tr;
3600
3601 /* Always clear the trampoline and target prog from prog->aux to make
3602 * sure the original attach destination is not kept alive after a
3603 * program is (re-)attached to another target.
3604 */
3605 if (prog->aux->dst_prog &&
3606 (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3607 /* got extra prog ref from syscall, or attaching to different prog */
3608 bpf_prog_put(prog->aux->dst_prog);
3609 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3610 /* we allocated a new trampoline, so free the old one */
3611 bpf_trampoline_put(prog->aux->dst_trampoline);
3612
3613 prog->aux->dst_prog = NULL;
3614 prog->aux->dst_trampoline = NULL;
3615 mutex_unlock(&prog->aux->dst_mutex);
3616
3617 return bpf_link_settle(&link_primer);
3618 out_unlock:
3619 if (tr && tr != prog->aux->dst_trampoline)
3620 bpf_trampoline_put(tr);
3621 mutex_unlock(&prog->aux->dst_mutex);
3622 kfree(link);
3623 out_put_prog:
3624 if (tgt_prog_fd && tgt_prog)
3625 bpf_prog_put(tgt_prog);
3626 return err;
3627 }
3628
bpf_raw_tp_link_release(struct bpf_link * link)3629 static void bpf_raw_tp_link_release(struct bpf_link *link)
3630 {
3631 struct bpf_raw_tp_link *raw_tp =
3632 container_of(link, struct bpf_raw_tp_link, link);
3633
3634 bpf_probe_unregister(raw_tp->btp, raw_tp);
3635 bpf_put_raw_tracepoint(raw_tp->btp);
3636 }
3637
bpf_raw_tp_link_dealloc(struct bpf_link * link)3638 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3639 {
3640 struct bpf_raw_tp_link *raw_tp =
3641 container_of(link, struct bpf_raw_tp_link, link);
3642
3643 kfree(raw_tp);
3644 }
3645
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3646 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3647 struct seq_file *seq)
3648 {
3649 struct bpf_raw_tp_link *raw_tp_link =
3650 container_of(link, struct bpf_raw_tp_link, link);
3651
3652 seq_printf(seq,
3653 "tp_name:\t%s\n",
3654 raw_tp_link->btp->tp->name);
3655 }
3656
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3657 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3658 u32 len)
3659 {
3660 if (ulen >= len + 1) {
3661 if (copy_to_user(ubuf, buf, len + 1))
3662 return -EFAULT;
3663 } else {
3664 char zero = '\0';
3665
3666 if (copy_to_user(ubuf, buf, ulen - 1))
3667 return -EFAULT;
3668 if (put_user(zero, ubuf + ulen - 1))
3669 return -EFAULT;
3670 return -ENOSPC;
3671 }
3672
3673 return 0;
3674 }
3675
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3676 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3677 struct bpf_link_info *info)
3678 {
3679 struct bpf_raw_tp_link *raw_tp_link =
3680 container_of(link, struct bpf_raw_tp_link, link);
3681 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3682 const char *tp_name = raw_tp_link->btp->tp->name;
3683 u32 ulen = info->raw_tracepoint.tp_name_len;
3684 size_t tp_len = strlen(tp_name);
3685
3686 if (!ulen ^ !ubuf)
3687 return -EINVAL;
3688
3689 info->raw_tracepoint.tp_name_len = tp_len + 1;
3690
3691 if (!ubuf)
3692 return 0;
3693
3694 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3695 }
3696
3697 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3698 .release = bpf_raw_tp_link_release,
3699 .dealloc_deferred = bpf_raw_tp_link_dealloc,
3700 .show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3701 .fill_link_info = bpf_raw_tp_link_fill_link_info,
3702 };
3703
3704 #ifdef CONFIG_PERF_EVENTS
3705 struct bpf_perf_link {
3706 struct bpf_link link;
3707 struct file *perf_file;
3708 };
3709
bpf_perf_link_release(struct bpf_link * link)3710 static void bpf_perf_link_release(struct bpf_link *link)
3711 {
3712 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3713 struct perf_event *event = perf_link->perf_file->private_data;
3714
3715 perf_event_free_bpf_prog(event);
3716 fput(perf_link->perf_file);
3717 }
3718
bpf_perf_link_dealloc(struct bpf_link * link)3719 static void bpf_perf_link_dealloc(struct bpf_link *link)
3720 {
3721 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3722
3723 kfree(perf_link);
3724 }
3725
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)3726 static int bpf_perf_link_fill_common(const struct perf_event *event,
3727 char __user *uname, u32 *ulenp,
3728 u64 *probe_offset, u64 *probe_addr,
3729 u32 *fd_type, unsigned long *missed)
3730 {
3731 const char *buf;
3732 u32 prog_id, ulen;
3733 size_t len;
3734 int err;
3735
3736 ulen = *ulenp;
3737 if (!ulen ^ !uname)
3738 return -EINVAL;
3739
3740 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3741 probe_offset, probe_addr, missed);
3742 if (err)
3743 return err;
3744
3745 if (buf) {
3746 len = strlen(buf);
3747 *ulenp = len + 1;
3748 } else {
3749 *ulenp = 1;
3750 }
3751 if (!uname)
3752 return 0;
3753
3754 if (buf) {
3755 err = bpf_copy_to_user(uname, buf, ulen, len);
3756 if (err)
3757 return err;
3758 } else {
3759 char zero = '\0';
3760
3761 if (put_user(zero, uname))
3762 return -EFAULT;
3763 }
3764 return 0;
3765 }
3766
3767 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3768 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3769 struct bpf_link_info *info)
3770 {
3771 unsigned long missed;
3772 char __user *uname;
3773 u64 addr, offset;
3774 u32 ulen, type;
3775 int err;
3776
3777 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3778 ulen = info->perf_event.kprobe.name_len;
3779 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3780 &type, &missed);
3781 if (err)
3782 return err;
3783 if (type == BPF_FD_TYPE_KRETPROBE)
3784 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3785 else
3786 info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3787 info->perf_event.kprobe.name_len = ulen;
3788 info->perf_event.kprobe.offset = offset;
3789 info->perf_event.kprobe.missed = missed;
3790 if (!kallsyms_show_value(current_cred()))
3791 addr = 0;
3792 info->perf_event.kprobe.addr = addr;
3793 info->perf_event.kprobe.cookie = event->bpf_cookie;
3794 return 0;
3795 }
3796 #endif
3797
3798 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3799 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3800 struct bpf_link_info *info)
3801 {
3802 char __user *uname;
3803 u64 addr, offset;
3804 u32 ulen, type;
3805 int err;
3806
3807 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3808 ulen = info->perf_event.uprobe.name_len;
3809 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3810 &type, NULL);
3811 if (err)
3812 return err;
3813
3814 if (type == BPF_FD_TYPE_URETPROBE)
3815 info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3816 else
3817 info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3818 info->perf_event.uprobe.name_len = ulen;
3819 info->perf_event.uprobe.offset = offset;
3820 info->perf_event.uprobe.cookie = event->bpf_cookie;
3821 return 0;
3822 }
3823 #endif
3824
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)3825 static int bpf_perf_link_fill_probe(const struct perf_event *event,
3826 struct bpf_link_info *info)
3827 {
3828 #ifdef CONFIG_KPROBE_EVENTS
3829 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
3830 return bpf_perf_link_fill_kprobe(event, info);
3831 #endif
3832 #ifdef CONFIG_UPROBE_EVENTS
3833 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
3834 return bpf_perf_link_fill_uprobe(event, info);
3835 #endif
3836 return -EOPNOTSUPP;
3837 }
3838
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)3839 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
3840 struct bpf_link_info *info)
3841 {
3842 char __user *uname;
3843 u32 ulen;
3844 int err;
3845
3846 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
3847 ulen = info->perf_event.tracepoint.name_len;
3848 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
3849 if (err)
3850 return err;
3851
3852 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
3853 info->perf_event.tracepoint.name_len = ulen;
3854 info->perf_event.tracepoint.cookie = event->bpf_cookie;
3855 return 0;
3856 }
3857
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)3858 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
3859 struct bpf_link_info *info)
3860 {
3861 info->perf_event.event.type = event->attr.type;
3862 info->perf_event.event.config = event->attr.config;
3863 info->perf_event.event.cookie = event->bpf_cookie;
3864 info->perf_event.type = BPF_PERF_EVENT_EVENT;
3865 return 0;
3866 }
3867
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3868 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
3869 struct bpf_link_info *info)
3870 {
3871 struct bpf_perf_link *perf_link;
3872 const struct perf_event *event;
3873
3874 perf_link = container_of(link, struct bpf_perf_link, link);
3875 event = perf_get_event(perf_link->perf_file);
3876 if (IS_ERR(event))
3877 return PTR_ERR(event);
3878
3879 switch (event->prog->type) {
3880 case BPF_PROG_TYPE_PERF_EVENT:
3881 return bpf_perf_link_fill_perf_event(event, info);
3882 case BPF_PROG_TYPE_TRACEPOINT:
3883 return bpf_perf_link_fill_tracepoint(event, info);
3884 case BPF_PROG_TYPE_KPROBE:
3885 return bpf_perf_link_fill_probe(event, info);
3886 default:
3887 return -EOPNOTSUPP;
3888 }
3889 }
3890
3891 static const struct bpf_link_ops bpf_perf_link_lops = {
3892 .release = bpf_perf_link_release,
3893 .dealloc = bpf_perf_link_dealloc,
3894 .fill_link_info = bpf_perf_link_fill_link_info,
3895 };
3896
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3897 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3898 {
3899 struct bpf_link_primer link_primer;
3900 struct bpf_perf_link *link;
3901 struct perf_event *event;
3902 struct file *perf_file;
3903 int err;
3904
3905 if (attr->link_create.flags)
3906 return -EINVAL;
3907
3908 perf_file = perf_event_get(attr->link_create.target_fd);
3909 if (IS_ERR(perf_file))
3910 return PTR_ERR(perf_file);
3911
3912 link = kzalloc(sizeof(*link), GFP_USER);
3913 if (!link) {
3914 err = -ENOMEM;
3915 goto out_put_file;
3916 }
3917 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3918 link->perf_file = perf_file;
3919
3920 err = bpf_link_prime(&link->link, &link_primer);
3921 if (err) {
3922 kfree(link);
3923 goto out_put_file;
3924 }
3925
3926 event = perf_file->private_data;
3927 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3928 if (err) {
3929 bpf_link_cleanup(&link_primer);
3930 goto out_put_file;
3931 }
3932 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3933 bpf_prog_inc(prog);
3934
3935 return bpf_link_settle(&link_primer);
3936
3937 out_put_file:
3938 fput(perf_file);
3939 return err;
3940 }
3941 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3942 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3943 {
3944 return -EOPNOTSUPP;
3945 }
3946 #endif /* CONFIG_PERF_EVENTS */
3947
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie)3948 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3949 const char __user *user_tp_name, u64 cookie)
3950 {
3951 struct bpf_link_primer link_primer;
3952 struct bpf_raw_tp_link *link;
3953 struct bpf_raw_event_map *btp;
3954 const char *tp_name;
3955 char buf[128];
3956 int err;
3957
3958 switch (prog->type) {
3959 case BPF_PROG_TYPE_TRACING:
3960 case BPF_PROG_TYPE_EXT:
3961 case BPF_PROG_TYPE_LSM:
3962 if (user_tp_name)
3963 /* The attach point for this category of programs
3964 * should be specified via btf_id during program load.
3965 */
3966 return -EINVAL;
3967 if (prog->type == BPF_PROG_TYPE_TRACING &&
3968 prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3969 tp_name = prog->aux->attach_func_name;
3970 break;
3971 }
3972 return bpf_tracing_prog_attach(prog, 0, 0, 0);
3973 case BPF_PROG_TYPE_RAW_TRACEPOINT:
3974 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3975 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3976 return -EFAULT;
3977 buf[sizeof(buf) - 1] = 0;
3978 tp_name = buf;
3979 break;
3980 default:
3981 return -EINVAL;
3982 }
3983
3984 btp = bpf_get_raw_tracepoint(tp_name);
3985 if (!btp)
3986 return -ENOENT;
3987
3988 link = kzalloc(sizeof(*link), GFP_USER);
3989 if (!link) {
3990 err = -ENOMEM;
3991 goto out_put_btp;
3992 }
3993 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3994 &bpf_raw_tp_link_lops, prog,
3995 tracepoint_is_faultable(btp->tp));
3996 link->btp = btp;
3997 link->cookie = cookie;
3998
3999 err = bpf_link_prime(&link->link, &link_primer);
4000 if (err) {
4001 kfree(link);
4002 goto out_put_btp;
4003 }
4004
4005 err = bpf_probe_register(link->btp, link);
4006 if (err) {
4007 bpf_link_cleanup(&link_primer);
4008 goto out_put_btp;
4009 }
4010
4011 return bpf_link_settle(&link_primer);
4012
4013 out_put_btp:
4014 bpf_put_raw_tracepoint(btp);
4015 return err;
4016 }
4017
4018 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4019
bpf_raw_tracepoint_open(const union bpf_attr * attr)4020 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4021 {
4022 struct bpf_prog *prog;
4023 void __user *tp_name;
4024 __u64 cookie;
4025 int fd;
4026
4027 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4028 return -EINVAL;
4029
4030 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4031 if (IS_ERR(prog))
4032 return PTR_ERR(prog);
4033
4034 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4035 cookie = attr->raw_tracepoint.cookie;
4036 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie);
4037 if (fd < 0)
4038 bpf_prog_put(prog);
4039 return fd;
4040 }
4041
4042 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4043 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4044 {
4045 switch (attach_type) {
4046 case BPF_CGROUP_INET_INGRESS:
4047 case BPF_CGROUP_INET_EGRESS:
4048 return BPF_PROG_TYPE_CGROUP_SKB;
4049 case BPF_CGROUP_INET_SOCK_CREATE:
4050 case BPF_CGROUP_INET_SOCK_RELEASE:
4051 case BPF_CGROUP_INET4_POST_BIND:
4052 case BPF_CGROUP_INET6_POST_BIND:
4053 return BPF_PROG_TYPE_CGROUP_SOCK;
4054 case BPF_CGROUP_INET4_BIND:
4055 case BPF_CGROUP_INET6_BIND:
4056 case BPF_CGROUP_INET4_CONNECT:
4057 case BPF_CGROUP_INET6_CONNECT:
4058 case BPF_CGROUP_UNIX_CONNECT:
4059 case BPF_CGROUP_INET4_GETPEERNAME:
4060 case BPF_CGROUP_INET6_GETPEERNAME:
4061 case BPF_CGROUP_UNIX_GETPEERNAME:
4062 case BPF_CGROUP_INET4_GETSOCKNAME:
4063 case BPF_CGROUP_INET6_GETSOCKNAME:
4064 case BPF_CGROUP_UNIX_GETSOCKNAME:
4065 case BPF_CGROUP_UDP4_SENDMSG:
4066 case BPF_CGROUP_UDP6_SENDMSG:
4067 case BPF_CGROUP_UNIX_SENDMSG:
4068 case BPF_CGROUP_UDP4_RECVMSG:
4069 case BPF_CGROUP_UDP6_RECVMSG:
4070 case BPF_CGROUP_UNIX_RECVMSG:
4071 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4072 case BPF_CGROUP_SOCK_OPS:
4073 return BPF_PROG_TYPE_SOCK_OPS;
4074 case BPF_CGROUP_DEVICE:
4075 return BPF_PROG_TYPE_CGROUP_DEVICE;
4076 case BPF_SK_MSG_VERDICT:
4077 return BPF_PROG_TYPE_SK_MSG;
4078 case BPF_SK_SKB_STREAM_PARSER:
4079 case BPF_SK_SKB_STREAM_VERDICT:
4080 case BPF_SK_SKB_VERDICT:
4081 return BPF_PROG_TYPE_SK_SKB;
4082 case BPF_LIRC_MODE2:
4083 return BPF_PROG_TYPE_LIRC_MODE2;
4084 case BPF_FLOW_DISSECTOR:
4085 return BPF_PROG_TYPE_FLOW_DISSECTOR;
4086 case BPF_CGROUP_SYSCTL:
4087 return BPF_PROG_TYPE_CGROUP_SYSCTL;
4088 case BPF_CGROUP_GETSOCKOPT:
4089 case BPF_CGROUP_SETSOCKOPT:
4090 return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4091 case BPF_TRACE_ITER:
4092 case BPF_TRACE_RAW_TP:
4093 case BPF_TRACE_FENTRY:
4094 case BPF_TRACE_FEXIT:
4095 case BPF_MODIFY_RETURN:
4096 return BPF_PROG_TYPE_TRACING;
4097 case BPF_LSM_MAC:
4098 return BPF_PROG_TYPE_LSM;
4099 case BPF_SK_LOOKUP:
4100 return BPF_PROG_TYPE_SK_LOOKUP;
4101 case BPF_XDP:
4102 return BPF_PROG_TYPE_XDP;
4103 case BPF_LSM_CGROUP:
4104 return BPF_PROG_TYPE_LSM;
4105 case BPF_TCX_INGRESS:
4106 case BPF_TCX_EGRESS:
4107 case BPF_NETKIT_PRIMARY:
4108 case BPF_NETKIT_PEER:
4109 return BPF_PROG_TYPE_SCHED_CLS;
4110 default:
4111 return BPF_PROG_TYPE_UNSPEC;
4112 }
4113 }
4114
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4115 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4116 enum bpf_attach_type attach_type)
4117 {
4118 enum bpf_prog_type ptype;
4119
4120 switch (prog->type) {
4121 case BPF_PROG_TYPE_CGROUP_SOCK:
4122 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4123 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4124 case BPF_PROG_TYPE_SK_LOOKUP:
4125 return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4126 case BPF_PROG_TYPE_CGROUP_SKB:
4127 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4128 /* cg-skb progs can be loaded by unpriv user.
4129 * check permissions at attach time.
4130 */
4131 return -EPERM;
4132
4133 ptype = attach_type_to_prog_type(attach_type);
4134 if (prog->type != ptype)
4135 return -EINVAL;
4136
4137 return prog->enforce_expected_attach_type &&
4138 prog->expected_attach_type != attach_type ?
4139 -EINVAL : 0;
4140 case BPF_PROG_TYPE_EXT:
4141 return 0;
4142 case BPF_PROG_TYPE_NETFILTER:
4143 if (attach_type != BPF_NETFILTER)
4144 return -EINVAL;
4145 return 0;
4146 case BPF_PROG_TYPE_PERF_EVENT:
4147 case BPF_PROG_TYPE_TRACEPOINT:
4148 if (attach_type != BPF_PERF_EVENT)
4149 return -EINVAL;
4150 return 0;
4151 case BPF_PROG_TYPE_KPROBE:
4152 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4153 attach_type != BPF_TRACE_KPROBE_MULTI)
4154 return -EINVAL;
4155 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4156 attach_type != BPF_TRACE_KPROBE_SESSION)
4157 return -EINVAL;
4158 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4159 attach_type != BPF_TRACE_UPROBE_MULTI)
4160 return -EINVAL;
4161 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4162 attach_type != BPF_TRACE_UPROBE_SESSION)
4163 return -EINVAL;
4164 if (attach_type != BPF_PERF_EVENT &&
4165 attach_type != BPF_TRACE_KPROBE_MULTI &&
4166 attach_type != BPF_TRACE_KPROBE_SESSION &&
4167 attach_type != BPF_TRACE_UPROBE_MULTI &&
4168 attach_type != BPF_TRACE_UPROBE_SESSION)
4169 return -EINVAL;
4170 return 0;
4171 case BPF_PROG_TYPE_SCHED_CLS:
4172 if (attach_type != BPF_TCX_INGRESS &&
4173 attach_type != BPF_TCX_EGRESS &&
4174 attach_type != BPF_NETKIT_PRIMARY &&
4175 attach_type != BPF_NETKIT_PEER)
4176 return -EINVAL;
4177 return 0;
4178 default:
4179 ptype = attach_type_to_prog_type(attach_type);
4180 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4181 return -EINVAL;
4182 return 0;
4183 }
4184 }
4185
4186 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4187
4188 #define BPF_F_ATTACH_MASK_BASE \
4189 (BPF_F_ALLOW_OVERRIDE | \
4190 BPF_F_ALLOW_MULTI | \
4191 BPF_F_REPLACE | \
4192 BPF_F_PREORDER)
4193
4194 #define BPF_F_ATTACH_MASK_MPROG \
4195 (BPF_F_REPLACE | \
4196 BPF_F_BEFORE | \
4197 BPF_F_AFTER | \
4198 BPF_F_ID | \
4199 BPF_F_LINK)
4200
bpf_prog_attach(const union bpf_attr * attr)4201 static int bpf_prog_attach(const union bpf_attr *attr)
4202 {
4203 enum bpf_prog_type ptype;
4204 struct bpf_prog *prog;
4205 int ret;
4206
4207 if (CHECK_ATTR(BPF_PROG_ATTACH))
4208 return -EINVAL;
4209
4210 ptype = attach_type_to_prog_type(attr->attach_type);
4211 if (ptype == BPF_PROG_TYPE_UNSPEC)
4212 return -EINVAL;
4213 if (bpf_mprog_supported(ptype)) {
4214 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4215 return -EINVAL;
4216 } else {
4217 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4218 return -EINVAL;
4219 if (attr->relative_fd ||
4220 attr->expected_revision)
4221 return -EINVAL;
4222 }
4223
4224 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4225 if (IS_ERR(prog))
4226 return PTR_ERR(prog);
4227
4228 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4229 bpf_prog_put(prog);
4230 return -EINVAL;
4231 }
4232
4233 switch (ptype) {
4234 case BPF_PROG_TYPE_SK_SKB:
4235 case BPF_PROG_TYPE_SK_MSG:
4236 ret = sock_map_get_from_fd(attr, prog);
4237 break;
4238 case BPF_PROG_TYPE_LIRC_MODE2:
4239 ret = lirc_prog_attach(attr, prog);
4240 break;
4241 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4242 ret = netns_bpf_prog_attach(attr, prog);
4243 break;
4244 case BPF_PROG_TYPE_CGROUP_DEVICE:
4245 case BPF_PROG_TYPE_CGROUP_SKB:
4246 case BPF_PROG_TYPE_CGROUP_SOCK:
4247 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4248 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4249 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4250 case BPF_PROG_TYPE_SOCK_OPS:
4251 case BPF_PROG_TYPE_LSM:
4252 if (ptype == BPF_PROG_TYPE_LSM &&
4253 prog->expected_attach_type != BPF_LSM_CGROUP)
4254 ret = -EINVAL;
4255 else
4256 ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4257 break;
4258 case BPF_PROG_TYPE_SCHED_CLS:
4259 if (attr->attach_type == BPF_TCX_INGRESS ||
4260 attr->attach_type == BPF_TCX_EGRESS)
4261 ret = tcx_prog_attach(attr, prog);
4262 else
4263 ret = netkit_prog_attach(attr, prog);
4264 break;
4265 default:
4266 ret = -EINVAL;
4267 }
4268
4269 if (ret)
4270 bpf_prog_put(prog);
4271 return ret;
4272 }
4273
4274 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4275
bpf_prog_detach(const union bpf_attr * attr)4276 static int bpf_prog_detach(const union bpf_attr *attr)
4277 {
4278 struct bpf_prog *prog = NULL;
4279 enum bpf_prog_type ptype;
4280 int ret;
4281
4282 if (CHECK_ATTR(BPF_PROG_DETACH))
4283 return -EINVAL;
4284
4285 ptype = attach_type_to_prog_type(attr->attach_type);
4286 if (bpf_mprog_supported(ptype)) {
4287 if (ptype == BPF_PROG_TYPE_UNSPEC)
4288 return -EINVAL;
4289 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4290 return -EINVAL;
4291 if (attr->attach_bpf_fd) {
4292 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4293 if (IS_ERR(prog))
4294 return PTR_ERR(prog);
4295 }
4296 } else if (attr->attach_flags ||
4297 attr->relative_fd ||
4298 attr->expected_revision) {
4299 return -EINVAL;
4300 }
4301
4302 switch (ptype) {
4303 case BPF_PROG_TYPE_SK_MSG:
4304 case BPF_PROG_TYPE_SK_SKB:
4305 ret = sock_map_prog_detach(attr, ptype);
4306 break;
4307 case BPF_PROG_TYPE_LIRC_MODE2:
4308 ret = lirc_prog_detach(attr);
4309 break;
4310 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4311 ret = netns_bpf_prog_detach(attr, ptype);
4312 break;
4313 case BPF_PROG_TYPE_CGROUP_DEVICE:
4314 case BPF_PROG_TYPE_CGROUP_SKB:
4315 case BPF_PROG_TYPE_CGROUP_SOCK:
4316 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4317 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4318 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4319 case BPF_PROG_TYPE_SOCK_OPS:
4320 case BPF_PROG_TYPE_LSM:
4321 ret = cgroup_bpf_prog_detach(attr, ptype);
4322 break;
4323 case BPF_PROG_TYPE_SCHED_CLS:
4324 if (attr->attach_type == BPF_TCX_INGRESS ||
4325 attr->attach_type == BPF_TCX_EGRESS)
4326 ret = tcx_prog_detach(attr, prog);
4327 else
4328 ret = netkit_prog_detach(attr, prog);
4329 break;
4330 default:
4331 ret = -EINVAL;
4332 }
4333
4334 if (prog)
4335 bpf_prog_put(prog);
4336 return ret;
4337 }
4338
4339 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4340
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4341 static int bpf_prog_query(const union bpf_attr *attr,
4342 union bpf_attr __user *uattr)
4343 {
4344 if (!bpf_net_capable())
4345 return -EPERM;
4346 if (CHECK_ATTR(BPF_PROG_QUERY))
4347 return -EINVAL;
4348 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4349 return -EINVAL;
4350
4351 switch (attr->query.attach_type) {
4352 case BPF_CGROUP_INET_INGRESS:
4353 case BPF_CGROUP_INET_EGRESS:
4354 case BPF_CGROUP_INET_SOCK_CREATE:
4355 case BPF_CGROUP_INET_SOCK_RELEASE:
4356 case BPF_CGROUP_INET4_BIND:
4357 case BPF_CGROUP_INET6_BIND:
4358 case BPF_CGROUP_INET4_POST_BIND:
4359 case BPF_CGROUP_INET6_POST_BIND:
4360 case BPF_CGROUP_INET4_CONNECT:
4361 case BPF_CGROUP_INET6_CONNECT:
4362 case BPF_CGROUP_UNIX_CONNECT:
4363 case BPF_CGROUP_INET4_GETPEERNAME:
4364 case BPF_CGROUP_INET6_GETPEERNAME:
4365 case BPF_CGROUP_UNIX_GETPEERNAME:
4366 case BPF_CGROUP_INET4_GETSOCKNAME:
4367 case BPF_CGROUP_INET6_GETSOCKNAME:
4368 case BPF_CGROUP_UNIX_GETSOCKNAME:
4369 case BPF_CGROUP_UDP4_SENDMSG:
4370 case BPF_CGROUP_UDP6_SENDMSG:
4371 case BPF_CGROUP_UNIX_SENDMSG:
4372 case BPF_CGROUP_UDP4_RECVMSG:
4373 case BPF_CGROUP_UDP6_RECVMSG:
4374 case BPF_CGROUP_UNIX_RECVMSG:
4375 case BPF_CGROUP_SOCK_OPS:
4376 case BPF_CGROUP_DEVICE:
4377 case BPF_CGROUP_SYSCTL:
4378 case BPF_CGROUP_GETSOCKOPT:
4379 case BPF_CGROUP_SETSOCKOPT:
4380 case BPF_LSM_CGROUP:
4381 return cgroup_bpf_prog_query(attr, uattr);
4382 case BPF_LIRC_MODE2:
4383 return lirc_prog_query(attr, uattr);
4384 case BPF_FLOW_DISSECTOR:
4385 case BPF_SK_LOOKUP:
4386 return netns_bpf_prog_query(attr, uattr);
4387 case BPF_SK_SKB_STREAM_PARSER:
4388 case BPF_SK_SKB_STREAM_VERDICT:
4389 case BPF_SK_MSG_VERDICT:
4390 case BPF_SK_SKB_VERDICT:
4391 return sock_map_bpf_prog_query(attr, uattr);
4392 case BPF_TCX_INGRESS:
4393 case BPF_TCX_EGRESS:
4394 return tcx_prog_query(attr, uattr);
4395 case BPF_NETKIT_PRIMARY:
4396 case BPF_NETKIT_PEER:
4397 return netkit_prog_query(attr, uattr);
4398 default:
4399 return -EINVAL;
4400 }
4401 }
4402
4403 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4404
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4405 static int bpf_prog_test_run(const union bpf_attr *attr,
4406 union bpf_attr __user *uattr)
4407 {
4408 struct bpf_prog *prog;
4409 int ret = -ENOTSUPP;
4410
4411 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4412 return -EINVAL;
4413
4414 if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4415 (!attr->test.ctx_size_in && attr->test.ctx_in))
4416 return -EINVAL;
4417
4418 if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4419 (!attr->test.ctx_size_out && attr->test.ctx_out))
4420 return -EINVAL;
4421
4422 prog = bpf_prog_get(attr->test.prog_fd);
4423 if (IS_ERR(prog))
4424 return PTR_ERR(prog);
4425
4426 if (prog->aux->ops->test_run)
4427 ret = prog->aux->ops->test_run(prog, attr, uattr);
4428
4429 bpf_prog_put(prog);
4430 return ret;
4431 }
4432
4433 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4434
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4435 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4436 union bpf_attr __user *uattr,
4437 struct idr *idr,
4438 spinlock_t *lock)
4439 {
4440 u32 next_id = attr->start_id;
4441 int err = 0;
4442
4443 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4444 return -EINVAL;
4445
4446 if (!capable(CAP_SYS_ADMIN))
4447 return -EPERM;
4448
4449 next_id++;
4450 spin_lock_bh(lock);
4451 if (!idr_get_next(idr, &next_id))
4452 err = -ENOENT;
4453 spin_unlock_bh(lock);
4454
4455 if (!err)
4456 err = put_user(next_id, &uattr->next_id);
4457
4458 return err;
4459 }
4460
bpf_map_get_curr_or_next(u32 * id)4461 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4462 {
4463 struct bpf_map *map;
4464
4465 spin_lock_bh(&map_idr_lock);
4466 again:
4467 map = idr_get_next(&map_idr, id);
4468 if (map) {
4469 map = __bpf_map_inc_not_zero(map, false);
4470 if (IS_ERR(map)) {
4471 (*id)++;
4472 goto again;
4473 }
4474 }
4475 spin_unlock_bh(&map_idr_lock);
4476
4477 return map;
4478 }
4479
bpf_prog_get_curr_or_next(u32 * id)4480 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4481 {
4482 struct bpf_prog *prog;
4483
4484 spin_lock_bh(&prog_idr_lock);
4485 again:
4486 prog = idr_get_next(&prog_idr, id);
4487 if (prog) {
4488 prog = bpf_prog_inc_not_zero(prog);
4489 if (IS_ERR(prog)) {
4490 (*id)++;
4491 goto again;
4492 }
4493 }
4494 spin_unlock_bh(&prog_idr_lock);
4495
4496 return prog;
4497 }
4498
4499 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4500
bpf_prog_by_id(u32 id)4501 struct bpf_prog *bpf_prog_by_id(u32 id)
4502 {
4503 struct bpf_prog *prog;
4504
4505 if (!id)
4506 return ERR_PTR(-ENOENT);
4507
4508 spin_lock_bh(&prog_idr_lock);
4509 prog = idr_find(&prog_idr, id);
4510 if (prog)
4511 prog = bpf_prog_inc_not_zero(prog);
4512 else
4513 prog = ERR_PTR(-ENOENT);
4514 spin_unlock_bh(&prog_idr_lock);
4515 return prog;
4516 }
4517
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4518 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4519 {
4520 struct bpf_prog *prog;
4521 u32 id = attr->prog_id;
4522 int fd;
4523
4524 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4525 return -EINVAL;
4526
4527 if (!capable(CAP_SYS_ADMIN))
4528 return -EPERM;
4529
4530 prog = bpf_prog_by_id(id);
4531 if (IS_ERR(prog))
4532 return PTR_ERR(prog);
4533
4534 fd = bpf_prog_new_fd(prog);
4535 if (fd < 0)
4536 bpf_prog_put(prog);
4537
4538 return fd;
4539 }
4540
4541 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4542
bpf_map_get_fd_by_id(const union bpf_attr * attr)4543 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4544 {
4545 struct bpf_map *map;
4546 u32 id = attr->map_id;
4547 int f_flags;
4548 int fd;
4549
4550 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4551 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4552 return -EINVAL;
4553
4554 if (!capable(CAP_SYS_ADMIN))
4555 return -EPERM;
4556
4557 f_flags = bpf_get_file_flag(attr->open_flags);
4558 if (f_flags < 0)
4559 return f_flags;
4560
4561 spin_lock_bh(&map_idr_lock);
4562 map = idr_find(&map_idr, id);
4563 if (map)
4564 map = __bpf_map_inc_not_zero(map, true);
4565 else
4566 map = ERR_PTR(-ENOENT);
4567 spin_unlock_bh(&map_idr_lock);
4568
4569 if (IS_ERR(map))
4570 return PTR_ERR(map);
4571
4572 fd = bpf_map_new_fd(map, f_flags);
4573 if (fd < 0)
4574 bpf_map_put_with_uref(map);
4575
4576 return fd;
4577 }
4578
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4579 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4580 unsigned long addr, u32 *off,
4581 u32 *type)
4582 {
4583 const struct bpf_map *map;
4584 int i;
4585
4586 mutex_lock(&prog->aux->used_maps_mutex);
4587 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4588 map = prog->aux->used_maps[i];
4589 if (map == (void *)addr) {
4590 *type = BPF_PSEUDO_MAP_FD;
4591 goto out;
4592 }
4593 if (!map->ops->map_direct_value_meta)
4594 continue;
4595 if (!map->ops->map_direct_value_meta(map, addr, off)) {
4596 *type = BPF_PSEUDO_MAP_VALUE;
4597 goto out;
4598 }
4599 }
4600 map = NULL;
4601
4602 out:
4603 mutex_unlock(&prog->aux->used_maps_mutex);
4604 return map;
4605 }
4606
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4607 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4608 const struct cred *f_cred)
4609 {
4610 const struct bpf_map *map;
4611 struct bpf_insn *insns;
4612 u32 off, type;
4613 u64 imm;
4614 u8 code;
4615 int i;
4616
4617 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4618 GFP_USER);
4619 if (!insns)
4620 return insns;
4621
4622 for (i = 0; i < prog->len; i++) {
4623 code = insns[i].code;
4624
4625 if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4626 insns[i].code = BPF_JMP | BPF_CALL;
4627 insns[i].imm = BPF_FUNC_tail_call;
4628 /* fall-through */
4629 }
4630 if (code == (BPF_JMP | BPF_CALL) ||
4631 code == (BPF_JMP | BPF_CALL_ARGS)) {
4632 if (code == (BPF_JMP | BPF_CALL_ARGS))
4633 insns[i].code = BPF_JMP | BPF_CALL;
4634 if (!bpf_dump_raw_ok(f_cred))
4635 insns[i].imm = 0;
4636 continue;
4637 }
4638 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4639 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4640 continue;
4641 }
4642
4643 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4644 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4645 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4646 continue;
4647 }
4648
4649 if (code != (BPF_LD | BPF_IMM | BPF_DW))
4650 continue;
4651
4652 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4653 map = bpf_map_from_imm(prog, imm, &off, &type);
4654 if (map) {
4655 insns[i].src_reg = type;
4656 insns[i].imm = map->id;
4657 insns[i + 1].imm = off;
4658 continue;
4659 }
4660 }
4661
4662 return insns;
4663 }
4664
set_info_rec_size(struct bpf_prog_info * info)4665 static int set_info_rec_size(struct bpf_prog_info *info)
4666 {
4667 /*
4668 * Ensure info.*_rec_size is the same as kernel expected size
4669 *
4670 * or
4671 *
4672 * Only allow zero *_rec_size if both _rec_size and _cnt are
4673 * zero. In this case, the kernel will set the expected
4674 * _rec_size back to the info.
4675 */
4676
4677 if ((info->nr_func_info || info->func_info_rec_size) &&
4678 info->func_info_rec_size != sizeof(struct bpf_func_info))
4679 return -EINVAL;
4680
4681 if ((info->nr_line_info || info->line_info_rec_size) &&
4682 info->line_info_rec_size != sizeof(struct bpf_line_info))
4683 return -EINVAL;
4684
4685 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4686 info->jited_line_info_rec_size != sizeof(__u64))
4687 return -EINVAL;
4688
4689 info->func_info_rec_size = sizeof(struct bpf_func_info);
4690 info->line_info_rec_size = sizeof(struct bpf_line_info);
4691 info->jited_line_info_rec_size = sizeof(__u64);
4692
4693 return 0;
4694 }
4695
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4696 static int bpf_prog_get_info_by_fd(struct file *file,
4697 struct bpf_prog *prog,
4698 const union bpf_attr *attr,
4699 union bpf_attr __user *uattr)
4700 {
4701 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4702 struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4703 struct bpf_prog_info info;
4704 u32 info_len = attr->info.info_len;
4705 struct bpf_prog_kstats stats;
4706 char __user *uinsns;
4707 u32 ulen;
4708 int err;
4709
4710 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4711 if (err)
4712 return err;
4713 info_len = min_t(u32, sizeof(info), info_len);
4714
4715 memset(&info, 0, sizeof(info));
4716 if (copy_from_user(&info, uinfo, info_len))
4717 return -EFAULT;
4718
4719 info.type = prog->type;
4720 info.id = prog->aux->id;
4721 info.load_time = prog->aux->load_time;
4722 info.created_by_uid = from_kuid_munged(current_user_ns(),
4723 prog->aux->user->uid);
4724 info.gpl_compatible = prog->gpl_compatible;
4725
4726 memcpy(info.tag, prog->tag, sizeof(prog->tag));
4727 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
4728
4729 mutex_lock(&prog->aux->used_maps_mutex);
4730 ulen = info.nr_map_ids;
4731 info.nr_map_ids = prog->aux->used_map_cnt;
4732 ulen = min_t(u32, info.nr_map_ids, ulen);
4733 if (ulen) {
4734 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
4735 u32 i;
4736
4737 for (i = 0; i < ulen; i++)
4738 if (put_user(prog->aux->used_maps[i]->id,
4739 &user_map_ids[i])) {
4740 mutex_unlock(&prog->aux->used_maps_mutex);
4741 return -EFAULT;
4742 }
4743 }
4744 mutex_unlock(&prog->aux->used_maps_mutex);
4745
4746 err = set_info_rec_size(&info);
4747 if (err)
4748 return err;
4749
4750 bpf_prog_get_stats(prog, &stats);
4751 info.run_time_ns = stats.nsecs;
4752 info.run_cnt = stats.cnt;
4753 info.recursion_misses = stats.misses;
4754
4755 info.verified_insns = prog->aux->verified_insns;
4756 if (prog->aux->btf)
4757 info.btf_id = btf_obj_id(prog->aux->btf);
4758
4759 if (!bpf_capable()) {
4760 info.jited_prog_len = 0;
4761 info.xlated_prog_len = 0;
4762 info.nr_jited_ksyms = 0;
4763 info.nr_jited_func_lens = 0;
4764 info.nr_func_info = 0;
4765 info.nr_line_info = 0;
4766 info.nr_jited_line_info = 0;
4767 goto done;
4768 }
4769
4770 ulen = info.xlated_prog_len;
4771 info.xlated_prog_len = bpf_prog_insn_size(prog);
4772 if (info.xlated_prog_len && ulen) {
4773 struct bpf_insn *insns_sanitized;
4774 bool fault;
4775
4776 if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
4777 info.xlated_prog_insns = 0;
4778 goto done;
4779 }
4780 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
4781 if (!insns_sanitized)
4782 return -ENOMEM;
4783 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
4784 ulen = min_t(u32, info.xlated_prog_len, ulen);
4785 fault = copy_to_user(uinsns, insns_sanitized, ulen);
4786 kfree(insns_sanitized);
4787 if (fault)
4788 return -EFAULT;
4789 }
4790
4791 if (bpf_prog_is_offloaded(prog->aux)) {
4792 err = bpf_prog_offload_info_fill(&info, prog);
4793 if (err)
4794 return err;
4795 goto done;
4796 }
4797
4798 /* NOTE: the following code is supposed to be skipped for offload.
4799 * bpf_prog_offload_info_fill() is the place to fill similar fields
4800 * for offload.
4801 */
4802 ulen = info.jited_prog_len;
4803 if (prog->aux->func_cnt) {
4804 u32 i;
4805
4806 info.jited_prog_len = 0;
4807 for (i = 0; i < prog->aux->func_cnt; i++)
4808 info.jited_prog_len += prog->aux->func[i]->jited_len;
4809 } else {
4810 info.jited_prog_len = prog->jited_len;
4811 }
4812
4813 if (info.jited_prog_len && ulen) {
4814 if (bpf_dump_raw_ok(file->f_cred)) {
4815 uinsns = u64_to_user_ptr(info.jited_prog_insns);
4816 ulen = min_t(u32, info.jited_prog_len, ulen);
4817
4818 /* for multi-function programs, copy the JITed
4819 * instructions for all the functions
4820 */
4821 if (prog->aux->func_cnt) {
4822 u32 len, free, i;
4823 u8 *img;
4824
4825 free = ulen;
4826 for (i = 0; i < prog->aux->func_cnt; i++) {
4827 len = prog->aux->func[i]->jited_len;
4828 len = min_t(u32, len, free);
4829 img = (u8 *) prog->aux->func[i]->bpf_func;
4830 if (copy_to_user(uinsns, img, len))
4831 return -EFAULT;
4832 uinsns += len;
4833 free -= len;
4834 if (!free)
4835 break;
4836 }
4837 } else {
4838 if (copy_to_user(uinsns, prog->bpf_func, ulen))
4839 return -EFAULT;
4840 }
4841 } else {
4842 info.jited_prog_insns = 0;
4843 }
4844 }
4845
4846 ulen = info.nr_jited_ksyms;
4847 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4848 if (ulen) {
4849 if (bpf_dump_raw_ok(file->f_cred)) {
4850 unsigned long ksym_addr;
4851 u64 __user *user_ksyms;
4852 u32 i;
4853
4854 /* copy the address of the kernel symbol
4855 * corresponding to each function
4856 */
4857 ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4858 user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4859 if (prog->aux->func_cnt) {
4860 for (i = 0; i < ulen; i++) {
4861 ksym_addr = (unsigned long)
4862 prog->aux->func[i]->bpf_func;
4863 if (put_user((u64) ksym_addr,
4864 &user_ksyms[i]))
4865 return -EFAULT;
4866 }
4867 } else {
4868 ksym_addr = (unsigned long) prog->bpf_func;
4869 if (put_user((u64) ksym_addr, &user_ksyms[0]))
4870 return -EFAULT;
4871 }
4872 } else {
4873 info.jited_ksyms = 0;
4874 }
4875 }
4876
4877 ulen = info.nr_jited_func_lens;
4878 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4879 if (ulen) {
4880 if (bpf_dump_raw_ok(file->f_cred)) {
4881 u32 __user *user_lens;
4882 u32 func_len, i;
4883
4884 /* copy the JITed image lengths for each function */
4885 ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4886 user_lens = u64_to_user_ptr(info.jited_func_lens);
4887 if (prog->aux->func_cnt) {
4888 for (i = 0; i < ulen; i++) {
4889 func_len =
4890 prog->aux->func[i]->jited_len;
4891 if (put_user(func_len, &user_lens[i]))
4892 return -EFAULT;
4893 }
4894 } else {
4895 func_len = prog->jited_len;
4896 if (put_user(func_len, &user_lens[0]))
4897 return -EFAULT;
4898 }
4899 } else {
4900 info.jited_func_lens = 0;
4901 }
4902 }
4903
4904 info.attach_btf_id = prog->aux->attach_btf_id;
4905 if (attach_btf)
4906 info.attach_btf_obj_id = btf_obj_id(attach_btf);
4907
4908 ulen = info.nr_func_info;
4909 info.nr_func_info = prog->aux->func_info_cnt;
4910 if (info.nr_func_info && ulen) {
4911 char __user *user_finfo;
4912
4913 user_finfo = u64_to_user_ptr(info.func_info);
4914 ulen = min_t(u32, info.nr_func_info, ulen);
4915 if (copy_to_user(user_finfo, prog->aux->func_info,
4916 info.func_info_rec_size * ulen))
4917 return -EFAULT;
4918 }
4919
4920 ulen = info.nr_line_info;
4921 info.nr_line_info = prog->aux->nr_linfo;
4922 if (info.nr_line_info && ulen) {
4923 __u8 __user *user_linfo;
4924
4925 user_linfo = u64_to_user_ptr(info.line_info);
4926 ulen = min_t(u32, info.nr_line_info, ulen);
4927 if (copy_to_user(user_linfo, prog->aux->linfo,
4928 info.line_info_rec_size * ulen))
4929 return -EFAULT;
4930 }
4931
4932 ulen = info.nr_jited_line_info;
4933 if (prog->aux->jited_linfo)
4934 info.nr_jited_line_info = prog->aux->nr_linfo;
4935 else
4936 info.nr_jited_line_info = 0;
4937 if (info.nr_jited_line_info && ulen) {
4938 if (bpf_dump_raw_ok(file->f_cred)) {
4939 unsigned long line_addr;
4940 __u64 __user *user_linfo;
4941 u32 i;
4942
4943 user_linfo = u64_to_user_ptr(info.jited_line_info);
4944 ulen = min_t(u32, info.nr_jited_line_info, ulen);
4945 for (i = 0; i < ulen; i++) {
4946 line_addr = (unsigned long)prog->aux->jited_linfo[i];
4947 if (put_user((__u64)line_addr, &user_linfo[i]))
4948 return -EFAULT;
4949 }
4950 } else {
4951 info.jited_line_info = 0;
4952 }
4953 }
4954
4955 ulen = info.nr_prog_tags;
4956 info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4957 if (ulen) {
4958 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4959 u32 i;
4960
4961 user_prog_tags = u64_to_user_ptr(info.prog_tags);
4962 ulen = min_t(u32, info.nr_prog_tags, ulen);
4963 if (prog->aux->func_cnt) {
4964 for (i = 0; i < ulen; i++) {
4965 if (copy_to_user(user_prog_tags[i],
4966 prog->aux->func[i]->tag,
4967 BPF_TAG_SIZE))
4968 return -EFAULT;
4969 }
4970 } else {
4971 if (copy_to_user(user_prog_tags[0],
4972 prog->tag, BPF_TAG_SIZE))
4973 return -EFAULT;
4974 }
4975 }
4976
4977 done:
4978 if (copy_to_user(uinfo, &info, info_len) ||
4979 put_user(info_len, &uattr->info.info_len))
4980 return -EFAULT;
4981
4982 return 0;
4983 }
4984
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4985 static int bpf_map_get_info_by_fd(struct file *file,
4986 struct bpf_map *map,
4987 const union bpf_attr *attr,
4988 union bpf_attr __user *uattr)
4989 {
4990 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4991 struct bpf_map_info info;
4992 u32 info_len = attr->info.info_len;
4993 int err;
4994
4995 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4996 if (err)
4997 return err;
4998 info_len = min_t(u32, sizeof(info), info_len);
4999
5000 memset(&info, 0, sizeof(info));
5001 info.type = map->map_type;
5002 info.id = map->id;
5003 info.key_size = map->key_size;
5004 info.value_size = map->value_size;
5005 info.max_entries = map->max_entries;
5006 info.map_flags = map->map_flags;
5007 info.map_extra = map->map_extra;
5008 memcpy(info.name, map->name, sizeof(map->name));
5009
5010 if (map->btf) {
5011 info.btf_id = btf_obj_id(map->btf);
5012 info.btf_key_type_id = map->btf_key_type_id;
5013 info.btf_value_type_id = map->btf_value_type_id;
5014 }
5015 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5016 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5017 bpf_map_struct_ops_info_fill(&info, map);
5018
5019 if (bpf_map_is_offloaded(map)) {
5020 err = bpf_map_offload_info_fill(&info, map);
5021 if (err)
5022 return err;
5023 }
5024
5025 if (copy_to_user(uinfo, &info, info_len) ||
5026 put_user(info_len, &uattr->info.info_len))
5027 return -EFAULT;
5028
5029 return 0;
5030 }
5031
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5032 static int bpf_btf_get_info_by_fd(struct file *file,
5033 struct btf *btf,
5034 const union bpf_attr *attr,
5035 union bpf_attr __user *uattr)
5036 {
5037 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5038 u32 info_len = attr->info.info_len;
5039 int err;
5040
5041 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5042 if (err)
5043 return err;
5044
5045 return btf_get_info_by_fd(btf, attr, uattr);
5046 }
5047
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5048 static int bpf_link_get_info_by_fd(struct file *file,
5049 struct bpf_link *link,
5050 const union bpf_attr *attr,
5051 union bpf_attr __user *uattr)
5052 {
5053 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5054 struct bpf_link_info info;
5055 u32 info_len = attr->info.info_len;
5056 int err;
5057
5058 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5059 if (err)
5060 return err;
5061 info_len = min_t(u32, sizeof(info), info_len);
5062
5063 memset(&info, 0, sizeof(info));
5064 if (copy_from_user(&info, uinfo, info_len))
5065 return -EFAULT;
5066
5067 info.type = link->type;
5068 info.id = link->id;
5069 if (link->prog)
5070 info.prog_id = link->prog->aux->id;
5071
5072 if (link->ops->fill_link_info) {
5073 err = link->ops->fill_link_info(link, &info);
5074 if (err)
5075 return err;
5076 }
5077
5078 if (copy_to_user(uinfo, &info, info_len) ||
5079 put_user(info_len, &uattr->info.info_len))
5080 return -EFAULT;
5081
5082 return 0;
5083 }
5084
5085
5086 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5087
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5088 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5089 union bpf_attr __user *uattr)
5090 {
5091 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5092 return -EINVAL;
5093
5094 CLASS(fd, f)(attr->info.bpf_fd);
5095 if (fd_empty(f))
5096 return -EBADFD;
5097
5098 if (fd_file(f)->f_op == &bpf_prog_fops)
5099 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5100 uattr);
5101 else if (fd_file(f)->f_op == &bpf_map_fops)
5102 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5103 uattr);
5104 else if (fd_file(f)->f_op == &btf_fops)
5105 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5106 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5107 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5108 attr, uattr);
5109 return -EINVAL;
5110 }
5111
5112 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5113
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5114 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5115 {
5116 struct bpf_token *token = NULL;
5117
5118 if (CHECK_ATTR(BPF_BTF_LOAD))
5119 return -EINVAL;
5120
5121 if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5122 return -EINVAL;
5123
5124 if (attr->btf_flags & BPF_F_TOKEN_FD) {
5125 token = bpf_token_get_from_fd(attr->btf_token_fd);
5126 if (IS_ERR(token))
5127 return PTR_ERR(token);
5128 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5129 bpf_token_put(token);
5130 token = NULL;
5131 }
5132 }
5133
5134 if (!bpf_token_capable(token, CAP_BPF)) {
5135 bpf_token_put(token);
5136 return -EPERM;
5137 }
5138
5139 bpf_token_put(token);
5140
5141 return btf_new_fd(attr, uattr, uattr_size);
5142 }
5143
5144 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5145
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5146 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5147 {
5148 struct bpf_token *token = NULL;
5149
5150 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5151 return -EINVAL;
5152
5153 if (attr->open_flags & ~BPF_F_TOKEN_FD)
5154 return -EINVAL;
5155
5156 if (attr->open_flags & BPF_F_TOKEN_FD) {
5157 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5158 if (IS_ERR(token))
5159 return PTR_ERR(token);
5160 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5161 bpf_token_put(token);
5162 token = NULL;
5163 }
5164 }
5165
5166 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5167 bpf_token_put(token);
5168 return -EPERM;
5169 }
5170
5171 bpf_token_put(token);
5172
5173 return btf_get_fd_by_id(attr->btf_id);
5174 }
5175
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)5176 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5177 union bpf_attr __user *uattr,
5178 u32 prog_id, u32 fd_type,
5179 const char *buf, u64 probe_offset,
5180 u64 probe_addr)
5181 {
5182 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5183 u32 len = buf ? strlen(buf) : 0, input_len;
5184 int err = 0;
5185
5186 if (put_user(len, &uattr->task_fd_query.buf_len))
5187 return -EFAULT;
5188 input_len = attr->task_fd_query.buf_len;
5189 if (input_len && ubuf) {
5190 if (!len) {
5191 /* nothing to copy, just make ubuf NULL terminated */
5192 char zero = '\0';
5193
5194 if (put_user(zero, ubuf))
5195 return -EFAULT;
5196 } else if (input_len >= len + 1) {
5197 /* ubuf can hold the string with NULL terminator */
5198 if (copy_to_user(ubuf, buf, len + 1))
5199 return -EFAULT;
5200 } else {
5201 /* ubuf cannot hold the string with NULL terminator,
5202 * do a partial copy with NULL terminator.
5203 */
5204 char zero = '\0';
5205
5206 err = -ENOSPC;
5207 if (copy_to_user(ubuf, buf, input_len - 1))
5208 return -EFAULT;
5209 if (put_user(zero, ubuf + input_len - 1))
5210 return -EFAULT;
5211 }
5212 }
5213
5214 if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5215 put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5216 put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5217 put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5218 return -EFAULT;
5219
5220 return err;
5221 }
5222
5223 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5224
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5225 static int bpf_task_fd_query(const union bpf_attr *attr,
5226 union bpf_attr __user *uattr)
5227 {
5228 pid_t pid = attr->task_fd_query.pid;
5229 u32 fd = attr->task_fd_query.fd;
5230 const struct perf_event *event;
5231 struct task_struct *task;
5232 struct file *file;
5233 int err;
5234
5235 if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5236 return -EINVAL;
5237
5238 if (!capable(CAP_SYS_ADMIN))
5239 return -EPERM;
5240
5241 if (attr->task_fd_query.flags != 0)
5242 return -EINVAL;
5243
5244 rcu_read_lock();
5245 task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5246 rcu_read_unlock();
5247 if (!task)
5248 return -ENOENT;
5249
5250 err = 0;
5251 file = fget_task(task, fd);
5252 put_task_struct(task);
5253 if (!file)
5254 return -EBADF;
5255
5256 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5257 struct bpf_link *link = file->private_data;
5258
5259 if (link->ops == &bpf_raw_tp_link_lops) {
5260 struct bpf_raw_tp_link *raw_tp =
5261 container_of(link, struct bpf_raw_tp_link, link);
5262 struct bpf_raw_event_map *btp = raw_tp->btp;
5263
5264 err = bpf_task_fd_query_copy(attr, uattr,
5265 raw_tp->link.prog->aux->id,
5266 BPF_FD_TYPE_RAW_TRACEPOINT,
5267 btp->tp->name, 0, 0);
5268 goto put_file;
5269 }
5270 goto out_not_supp;
5271 }
5272
5273 event = perf_get_event(file);
5274 if (!IS_ERR(event)) {
5275 u64 probe_offset, probe_addr;
5276 u32 prog_id, fd_type;
5277 const char *buf;
5278
5279 err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5280 &buf, &probe_offset,
5281 &probe_addr, NULL);
5282 if (!err)
5283 err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5284 fd_type, buf,
5285 probe_offset,
5286 probe_addr);
5287 goto put_file;
5288 }
5289
5290 out_not_supp:
5291 err = -ENOTSUPP;
5292 put_file:
5293 fput(file);
5294 return err;
5295 }
5296
5297 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5298
5299 #define BPF_DO_BATCH(fn, ...) \
5300 do { \
5301 if (!fn) { \
5302 err = -ENOTSUPP; \
5303 goto err_put; \
5304 } \
5305 err = fn(__VA_ARGS__); \
5306 } while (0)
5307
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5308 static int bpf_map_do_batch(const union bpf_attr *attr,
5309 union bpf_attr __user *uattr,
5310 int cmd)
5311 {
5312 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH ||
5313 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5314 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5315 struct bpf_map *map;
5316 int err;
5317
5318 if (CHECK_ATTR(BPF_MAP_BATCH))
5319 return -EINVAL;
5320
5321 CLASS(fd, f)(attr->batch.map_fd);
5322
5323 map = __bpf_map_get(f);
5324 if (IS_ERR(map))
5325 return PTR_ERR(map);
5326 if (has_write)
5327 bpf_map_write_active_inc(map);
5328 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5329 err = -EPERM;
5330 goto err_put;
5331 }
5332 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5333 err = -EPERM;
5334 goto err_put;
5335 }
5336
5337 if (cmd == BPF_MAP_LOOKUP_BATCH)
5338 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5339 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5340 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5341 else if (cmd == BPF_MAP_UPDATE_BATCH)
5342 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5343 else
5344 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5345 err_put:
5346 if (has_write) {
5347 maybe_wait_bpf_programs(map);
5348 bpf_map_write_active_dec(map);
5349 }
5350 return err;
5351 }
5352
5353 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5354 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5355 {
5356 struct bpf_prog *prog;
5357 int ret;
5358
5359 if (CHECK_ATTR(BPF_LINK_CREATE))
5360 return -EINVAL;
5361
5362 if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5363 return bpf_struct_ops_link_create(attr);
5364
5365 prog = bpf_prog_get(attr->link_create.prog_fd);
5366 if (IS_ERR(prog))
5367 return PTR_ERR(prog);
5368
5369 ret = bpf_prog_attach_check_attach_type(prog,
5370 attr->link_create.attach_type);
5371 if (ret)
5372 goto out;
5373
5374 switch (prog->type) {
5375 case BPF_PROG_TYPE_CGROUP_SKB:
5376 case BPF_PROG_TYPE_CGROUP_SOCK:
5377 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5378 case BPF_PROG_TYPE_SOCK_OPS:
5379 case BPF_PROG_TYPE_CGROUP_DEVICE:
5380 case BPF_PROG_TYPE_CGROUP_SYSCTL:
5381 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5382 ret = cgroup_bpf_link_attach(attr, prog);
5383 break;
5384 case BPF_PROG_TYPE_EXT:
5385 ret = bpf_tracing_prog_attach(prog,
5386 attr->link_create.target_fd,
5387 attr->link_create.target_btf_id,
5388 attr->link_create.tracing.cookie);
5389 break;
5390 case BPF_PROG_TYPE_LSM:
5391 case BPF_PROG_TYPE_TRACING:
5392 if (attr->link_create.attach_type != prog->expected_attach_type) {
5393 ret = -EINVAL;
5394 goto out;
5395 }
5396 if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5397 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie);
5398 else if (prog->expected_attach_type == BPF_TRACE_ITER)
5399 ret = bpf_iter_link_attach(attr, uattr, prog);
5400 else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5401 ret = cgroup_bpf_link_attach(attr, prog);
5402 else
5403 ret = bpf_tracing_prog_attach(prog,
5404 attr->link_create.target_fd,
5405 attr->link_create.target_btf_id,
5406 attr->link_create.tracing.cookie);
5407 break;
5408 case BPF_PROG_TYPE_FLOW_DISSECTOR:
5409 case BPF_PROG_TYPE_SK_LOOKUP:
5410 ret = netns_bpf_link_create(attr, prog);
5411 break;
5412 case BPF_PROG_TYPE_SK_MSG:
5413 case BPF_PROG_TYPE_SK_SKB:
5414 ret = sock_map_link_create(attr, prog);
5415 break;
5416 #ifdef CONFIG_NET
5417 case BPF_PROG_TYPE_XDP:
5418 ret = bpf_xdp_link_attach(attr, prog);
5419 break;
5420 case BPF_PROG_TYPE_SCHED_CLS:
5421 if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5422 attr->link_create.attach_type == BPF_TCX_EGRESS)
5423 ret = tcx_link_attach(attr, prog);
5424 else
5425 ret = netkit_link_attach(attr, prog);
5426 break;
5427 case BPF_PROG_TYPE_NETFILTER:
5428 ret = bpf_nf_link_attach(attr, prog);
5429 break;
5430 #endif
5431 case BPF_PROG_TYPE_PERF_EVENT:
5432 case BPF_PROG_TYPE_TRACEPOINT:
5433 ret = bpf_perf_link_attach(attr, prog);
5434 break;
5435 case BPF_PROG_TYPE_KPROBE:
5436 if (attr->link_create.attach_type == BPF_PERF_EVENT)
5437 ret = bpf_perf_link_attach(attr, prog);
5438 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5439 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5440 ret = bpf_kprobe_multi_link_attach(attr, prog);
5441 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5442 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5443 ret = bpf_uprobe_multi_link_attach(attr, prog);
5444 break;
5445 default:
5446 ret = -EINVAL;
5447 }
5448
5449 out:
5450 if (ret < 0)
5451 bpf_prog_put(prog);
5452 return ret;
5453 }
5454
link_update_map(struct bpf_link * link,union bpf_attr * attr)5455 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5456 {
5457 struct bpf_map *new_map, *old_map = NULL;
5458 int ret;
5459
5460 new_map = bpf_map_get(attr->link_update.new_map_fd);
5461 if (IS_ERR(new_map))
5462 return PTR_ERR(new_map);
5463
5464 if (attr->link_update.flags & BPF_F_REPLACE) {
5465 old_map = bpf_map_get(attr->link_update.old_map_fd);
5466 if (IS_ERR(old_map)) {
5467 ret = PTR_ERR(old_map);
5468 goto out_put;
5469 }
5470 } else if (attr->link_update.old_map_fd) {
5471 ret = -EINVAL;
5472 goto out_put;
5473 }
5474
5475 ret = link->ops->update_map(link, new_map, old_map);
5476
5477 if (old_map)
5478 bpf_map_put(old_map);
5479 out_put:
5480 bpf_map_put(new_map);
5481 return ret;
5482 }
5483
5484 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5485
link_update(union bpf_attr * attr)5486 static int link_update(union bpf_attr *attr)
5487 {
5488 struct bpf_prog *old_prog = NULL, *new_prog;
5489 struct bpf_link *link;
5490 u32 flags;
5491 int ret;
5492
5493 if (CHECK_ATTR(BPF_LINK_UPDATE))
5494 return -EINVAL;
5495
5496 flags = attr->link_update.flags;
5497 if (flags & ~BPF_F_REPLACE)
5498 return -EINVAL;
5499
5500 link = bpf_link_get_from_fd(attr->link_update.link_fd);
5501 if (IS_ERR(link))
5502 return PTR_ERR(link);
5503
5504 if (link->ops->update_map) {
5505 ret = link_update_map(link, attr);
5506 goto out_put_link;
5507 }
5508
5509 new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5510 if (IS_ERR(new_prog)) {
5511 ret = PTR_ERR(new_prog);
5512 goto out_put_link;
5513 }
5514
5515 if (flags & BPF_F_REPLACE) {
5516 old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5517 if (IS_ERR(old_prog)) {
5518 ret = PTR_ERR(old_prog);
5519 old_prog = NULL;
5520 goto out_put_progs;
5521 }
5522 } else if (attr->link_update.old_prog_fd) {
5523 ret = -EINVAL;
5524 goto out_put_progs;
5525 }
5526
5527 if (link->ops->update_prog)
5528 ret = link->ops->update_prog(link, new_prog, old_prog);
5529 else
5530 ret = -EINVAL;
5531
5532 out_put_progs:
5533 if (old_prog)
5534 bpf_prog_put(old_prog);
5535 if (ret)
5536 bpf_prog_put(new_prog);
5537 out_put_link:
5538 bpf_link_put_direct(link);
5539 return ret;
5540 }
5541
5542 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5543
link_detach(union bpf_attr * attr)5544 static int link_detach(union bpf_attr *attr)
5545 {
5546 struct bpf_link *link;
5547 int ret;
5548
5549 if (CHECK_ATTR(BPF_LINK_DETACH))
5550 return -EINVAL;
5551
5552 link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5553 if (IS_ERR(link))
5554 return PTR_ERR(link);
5555
5556 if (link->ops->detach)
5557 ret = link->ops->detach(link);
5558 else
5559 ret = -EOPNOTSUPP;
5560
5561 bpf_link_put_direct(link);
5562 return ret;
5563 }
5564
bpf_link_inc_not_zero(struct bpf_link * link)5565 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5566 {
5567 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5568 }
5569 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5570
bpf_link_by_id(u32 id)5571 struct bpf_link *bpf_link_by_id(u32 id)
5572 {
5573 struct bpf_link *link;
5574
5575 if (!id)
5576 return ERR_PTR(-ENOENT);
5577
5578 spin_lock_bh(&link_idr_lock);
5579 /* before link is "settled", ID is 0, pretend it doesn't exist yet */
5580 link = idr_find(&link_idr, id);
5581 if (link) {
5582 if (link->id)
5583 link = bpf_link_inc_not_zero(link);
5584 else
5585 link = ERR_PTR(-EAGAIN);
5586 } else {
5587 link = ERR_PTR(-ENOENT);
5588 }
5589 spin_unlock_bh(&link_idr_lock);
5590 return link;
5591 }
5592
bpf_link_get_curr_or_next(u32 * id)5593 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5594 {
5595 struct bpf_link *link;
5596
5597 spin_lock_bh(&link_idr_lock);
5598 again:
5599 link = idr_get_next(&link_idr, id);
5600 if (link) {
5601 link = bpf_link_inc_not_zero(link);
5602 if (IS_ERR(link)) {
5603 (*id)++;
5604 goto again;
5605 }
5606 }
5607 spin_unlock_bh(&link_idr_lock);
5608
5609 return link;
5610 }
5611
5612 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5613
bpf_link_get_fd_by_id(const union bpf_attr * attr)5614 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5615 {
5616 struct bpf_link *link;
5617 u32 id = attr->link_id;
5618 int fd;
5619
5620 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5621 return -EINVAL;
5622
5623 if (!capable(CAP_SYS_ADMIN))
5624 return -EPERM;
5625
5626 link = bpf_link_by_id(id);
5627 if (IS_ERR(link))
5628 return PTR_ERR(link);
5629
5630 fd = bpf_link_new_fd(link);
5631 if (fd < 0)
5632 bpf_link_put_direct(link);
5633
5634 return fd;
5635 }
5636
5637 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5638
bpf_stats_release(struct inode * inode,struct file * file)5639 static int bpf_stats_release(struct inode *inode, struct file *file)
5640 {
5641 mutex_lock(&bpf_stats_enabled_mutex);
5642 static_key_slow_dec(&bpf_stats_enabled_key.key);
5643 mutex_unlock(&bpf_stats_enabled_mutex);
5644 return 0;
5645 }
5646
5647 static const struct file_operations bpf_stats_fops = {
5648 .release = bpf_stats_release,
5649 };
5650
bpf_enable_runtime_stats(void)5651 static int bpf_enable_runtime_stats(void)
5652 {
5653 int fd;
5654
5655 mutex_lock(&bpf_stats_enabled_mutex);
5656
5657 /* Set a very high limit to avoid overflow */
5658 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5659 mutex_unlock(&bpf_stats_enabled_mutex);
5660 return -EBUSY;
5661 }
5662
5663 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5664 if (fd >= 0)
5665 static_key_slow_inc(&bpf_stats_enabled_key.key);
5666
5667 mutex_unlock(&bpf_stats_enabled_mutex);
5668 return fd;
5669 }
5670
5671 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5672
bpf_enable_stats(union bpf_attr * attr)5673 static int bpf_enable_stats(union bpf_attr *attr)
5674 {
5675
5676 if (CHECK_ATTR(BPF_ENABLE_STATS))
5677 return -EINVAL;
5678
5679 if (!capable(CAP_SYS_ADMIN))
5680 return -EPERM;
5681
5682 switch (attr->enable_stats.type) {
5683 case BPF_STATS_RUN_TIME:
5684 return bpf_enable_runtime_stats();
5685 default:
5686 break;
5687 }
5688 return -EINVAL;
5689 }
5690
5691 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
5692
bpf_iter_create(union bpf_attr * attr)5693 static int bpf_iter_create(union bpf_attr *attr)
5694 {
5695 struct bpf_link *link;
5696 int err;
5697
5698 if (CHECK_ATTR(BPF_ITER_CREATE))
5699 return -EINVAL;
5700
5701 if (attr->iter_create.flags)
5702 return -EINVAL;
5703
5704 link = bpf_link_get_from_fd(attr->iter_create.link_fd);
5705 if (IS_ERR(link))
5706 return PTR_ERR(link);
5707
5708 err = bpf_iter_new_fd(link);
5709 bpf_link_put_direct(link);
5710
5711 return err;
5712 }
5713
5714 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
5715
bpf_prog_bind_map(union bpf_attr * attr)5716 static int bpf_prog_bind_map(union bpf_attr *attr)
5717 {
5718 struct bpf_prog *prog;
5719 struct bpf_map *map;
5720 struct bpf_map **used_maps_old, **used_maps_new;
5721 int i, ret = 0;
5722
5723 if (CHECK_ATTR(BPF_PROG_BIND_MAP))
5724 return -EINVAL;
5725
5726 if (attr->prog_bind_map.flags)
5727 return -EINVAL;
5728
5729 prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
5730 if (IS_ERR(prog))
5731 return PTR_ERR(prog);
5732
5733 map = bpf_map_get(attr->prog_bind_map.map_fd);
5734 if (IS_ERR(map)) {
5735 ret = PTR_ERR(map);
5736 goto out_prog_put;
5737 }
5738
5739 mutex_lock(&prog->aux->used_maps_mutex);
5740
5741 used_maps_old = prog->aux->used_maps;
5742
5743 for (i = 0; i < prog->aux->used_map_cnt; i++)
5744 if (used_maps_old[i] == map) {
5745 bpf_map_put(map);
5746 goto out_unlock;
5747 }
5748
5749 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
5750 sizeof(used_maps_new[0]),
5751 GFP_KERNEL);
5752 if (!used_maps_new) {
5753 ret = -ENOMEM;
5754 goto out_unlock;
5755 }
5756
5757 /* The bpf program will not access the bpf map, but for the sake of
5758 * simplicity, increase sleepable_refcnt for sleepable program as well.
5759 */
5760 if (prog->sleepable)
5761 atomic64_inc(&map->sleepable_refcnt);
5762 memcpy(used_maps_new, used_maps_old,
5763 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
5764 used_maps_new[prog->aux->used_map_cnt] = map;
5765
5766 prog->aux->used_map_cnt++;
5767 prog->aux->used_maps = used_maps_new;
5768
5769 kfree(used_maps_old);
5770
5771 out_unlock:
5772 mutex_unlock(&prog->aux->used_maps_mutex);
5773
5774 if (ret)
5775 bpf_map_put(map);
5776 out_prog_put:
5777 bpf_prog_put(prog);
5778 return ret;
5779 }
5780
5781 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
5782
token_create(union bpf_attr * attr)5783 static int token_create(union bpf_attr *attr)
5784 {
5785 if (CHECK_ATTR(BPF_TOKEN_CREATE))
5786 return -EINVAL;
5787
5788 /* no flags are supported yet */
5789 if (attr->token_create.flags)
5790 return -EINVAL;
5791
5792 return bpf_token_create(attr);
5793 }
5794
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)5795 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
5796 {
5797 union bpf_attr attr;
5798 int err;
5799
5800 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
5801 if (err)
5802 return err;
5803 size = min_t(u32, size, sizeof(attr));
5804
5805 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
5806 memset(&attr, 0, sizeof(attr));
5807 if (copy_from_bpfptr(&attr, uattr, size) != 0)
5808 return -EFAULT;
5809
5810 err = security_bpf(cmd, &attr, size, uattr.is_kernel);
5811 if (err < 0)
5812 return err;
5813
5814 switch (cmd) {
5815 case BPF_MAP_CREATE:
5816 err = map_create(&attr, uattr.is_kernel);
5817 break;
5818 case BPF_MAP_LOOKUP_ELEM:
5819 err = map_lookup_elem(&attr);
5820 break;
5821 case BPF_MAP_UPDATE_ELEM:
5822 err = map_update_elem(&attr, uattr);
5823 break;
5824 case BPF_MAP_DELETE_ELEM:
5825 err = map_delete_elem(&attr, uattr);
5826 break;
5827 case BPF_MAP_GET_NEXT_KEY:
5828 err = map_get_next_key(&attr);
5829 break;
5830 case BPF_MAP_FREEZE:
5831 err = map_freeze(&attr);
5832 break;
5833 case BPF_PROG_LOAD:
5834 err = bpf_prog_load(&attr, uattr, size);
5835 break;
5836 case BPF_OBJ_PIN:
5837 err = bpf_obj_pin(&attr);
5838 break;
5839 case BPF_OBJ_GET:
5840 err = bpf_obj_get(&attr);
5841 break;
5842 case BPF_PROG_ATTACH:
5843 err = bpf_prog_attach(&attr);
5844 break;
5845 case BPF_PROG_DETACH:
5846 err = bpf_prog_detach(&attr);
5847 break;
5848 case BPF_PROG_QUERY:
5849 err = bpf_prog_query(&attr, uattr.user);
5850 break;
5851 case BPF_PROG_TEST_RUN:
5852 err = bpf_prog_test_run(&attr, uattr.user);
5853 break;
5854 case BPF_PROG_GET_NEXT_ID:
5855 err = bpf_obj_get_next_id(&attr, uattr.user,
5856 &prog_idr, &prog_idr_lock);
5857 break;
5858 case BPF_MAP_GET_NEXT_ID:
5859 err = bpf_obj_get_next_id(&attr, uattr.user,
5860 &map_idr, &map_idr_lock);
5861 break;
5862 case BPF_BTF_GET_NEXT_ID:
5863 err = bpf_obj_get_next_id(&attr, uattr.user,
5864 &btf_idr, &btf_idr_lock);
5865 break;
5866 case BPF_PROG_GET_FD_BY_ID:
5867 err = bpf_prog_get_fd_by_id(&attr);
5868 break;
5869 case BPF_MAP_GET_FD_BY_ID:
5870 err = bpf_map_get_fd_by_id(&attr);
5871 break;
5872 case BPF_OBJ_GET_INFO_BY_FD:
5873 err = bpf_obj_get_info_by_fd(&attr, uattr.user);
5874 break;
5875 case BPF_RAW_TRACEPOINT_OPEN:
5876 err = bpf_raw_tracepoint_open(&attr);
5877 break;
5878 case BPF_BTF_LOAD:
5879 err = bpf_btf_load(&attr, uattr, size);
5880 break;
5881 case BPF_BTF_GET_FD_BY_ID:
5882 err = bpf_btf_get_fd_by_id(&attr);
5883 break;
5884 case BPF_TASK_FD_QUERY:
5885 err = bpf_task_fd_query(&attr, uattr.user);
5886 break;
5887 case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
5888 err = map_lookup_and_delete_elem(&attr);
5889 break;
5890 case BPF_MAP_LOOKUP_BATCH:
5891 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
5892 break;
5893 case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
5894 err = bpf_map_do_batch(&attr, uattr.user,
5895 BPF_MAP_LOOKUP_AND_DELETE_BATCH);
5896 break;
5897 case BPF_MAP_UPDATE_BATCH:
5898 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
5899 break;
5900 case BPF_MAP_DELETE_BATCH:
5901 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
5902 break;
5903 case BPF_LINK_CREATE:
5904 err = link_create(&attr, uattr);
5905 break;
5906 case BPF_LINK_UPDATE:
5907 err = link_update(&attr);
5908 break;
5909 case BPF_LINK_GET_FD_BY_ID:
5910 err = bpf_link_get_fd_by_id(&attr);
5911 break;
5912 case BPF_LINK_GET_NEXT_ID:
5913 err = bpf_obj_get_next_id(&attr, uattr.user,
5914 &link_idr, &link_idr_lock);
5915 break;
5916 case BPF_ENABLE_STATS:
5917 err = bpf_enable_stats(&attr);
5918 break;
5919 case BPF_ITER_CREATE:
5920 err = bpf_iter_create(&attr);
5921 break;
5922 case BPF_LINK_DETACH:
5923 err = link_detach(&attr);
5924 break;
5925 case BPF_PROG_BIND_MAP:
5926 err = bpf_prog_bind_map(&attr);
5927 break;
5928 case BPF_TOKEN_CREATE:
5929 err = token_create(&attr);
5930 break;
5931 default:
5932 err = -EINVAL;
5933 break;
5934 }
5935
5936 return err;
5937 }
5938
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5939 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5940 {
5941 return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5942 }
5943
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)5944 static bool syscall_prog_is_valid_access(int off, int size,
5945 enum bpf_access_type type,
5946 const struct bpf_prog *prog,
5947 struct bpf_insn_access_aux *info)
5948 {
5949 if (off < 0 || off >= U16_MAX)
5950 return false;
5951 if (off % size != 0)
5952 return false;
5953 return true;
5954 }
5955
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5956 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5957 {
5958 switch (cmd) {
5959 case BPF_MAP_CREATE:
5960 case BPF_MAP_DELETE_ELEM:
5961 case BPF_MAP_UPDATE_ELEM:
5962 case BPF_MAP_FREEZE:
5963 case BPF_MAP_GET_FD_BY_ID:
5964 case BPF_PROG_LOAD:
5965 case BPF_BTF_LOAD:
5966 case BPF_LINK_CREATE:
5967 case BPF_RAW_TRACEPOINT_OPEN:
5968 break;
5969 default:
5970 return -EINVAL;
5971 }
5972 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5973 }
5974
5975
5976 /* To shut up -Wmissing-prototypes.
5977 * This function is used by the kernel light skeleton
5978 * to load bpf programs when modules are loaded or during kernel boot.
5979 * See tools/lib/bpf/skel_internal.h
5980 */
5981 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
5982
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5983 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5984 {
5985 struct bpf_prog * __maybe_unused prog;
5986 struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5987
5988 switch (cmd) {
5989 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5990 case BPF_PROG_TEST_RUN:
5991 if (attr->test.data_in || attr->test.data_out ||
5992 attr->test.ctx_out || attr->test.duration ||
5993 attr->test.repeat || attr->test.flags)
5994 return -EINVAL;
5995
5996 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5997 if (IS_ERR(prog))
5998 return PTR_ERR(prog);
5999
6000 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6001 attr->test.ctx_size_in > U16_MAX) {
6002 bpf_prog_put(prog);
6003 return -EINVAL;
6004 }
6005
6006 run_ctx.bpf_cookie = 0;
6007 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6008 /* recursion detected */
6009 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6010 bpf_prog_put(prog);
6011 return -EBUSY;
6012 }
6013 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6014 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6015 &run_ctx);
6016 bpf_prog_put(prog);
6017 return 0;
6018 #endif
6019 default:
6020 return ____bpf_sys_bpf(cmd, attr, size);
6021 }
6022 }
6023 EXPORT_SYMBOL(kern_sys_bpf);
6024
6025 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6026 .func = bpf_sys_bpf,
6027 .gpl_only = false,
6028 .ret_type = RET_INTEGER,
6029 .arg1_type = ARG_ANYTHING,
6030 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
6031 .arg3_type = ARG_CONST_SIZE,
6032 };
6033
6034 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6035 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6036 {
6037 return bpf_base_func_proto(func_id, prog);
6038 }
6039
BPF_CALL_1(bpf_sys_close,u32,fd)6040 BPF_CALL_1(bpf_sys_close, u32, fd)
6041 {
6042 /* When bpf program calls this helper there should not be
6043 * an fdget() without matching completed fdput().
6044 * This helper is allowed in the following callchain only:
6045 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6046 */
6047 return close_fd(fd);
6048 }
6049
6050 static const struct bpf_func_proto bpf_sys_close_proto = {
6051 .func = bpf_sys_close,
6052 .gpl_only = false,
6053 .ret_type = RET_INTEGER,
6054 .arg1_type = ARG_ANYTHING,
6055 };
6056
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6057 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6058 {
6059 *res = 0;
6060 if (flags)
6061 return -EINVAL;
6062
6063 if (name_sz <= 1 || name[name_sz - 1])
6064 return -EINVAL;
6065
6066 if (!bpf_dump_raw_ok(current_cred()))
6067 return -EPERM;
6068
6069 *res = kallsyms_lookup_name(name);
6070 return *res ? 0 : -ENOENT;
6071 }
6072
6073 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6074 .func = bpf_kallsyms_lookup_name,
6075 .gpl_only = false,
6076 .ret_type = RET_INTEGER,
6077 .arg1_type = ARG_PTR_TO_MEM,
6078 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
6079 .arg3_type = ARG_ANYTHING,
6080 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6081 .arg4_size = sizeof(u64),
6082 };
6083
6084 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6085 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6086 {
6087 switch (func_id) {
6088 case BPF_FUNC_sys_bpf:
6089 return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6090 ? NULL : &bpf_sys_bpf_proto;
6091 case BPF_FUNC_btf_find_by_name_kind:
6092 return &bpf_btf_find_by_name_kind_proto;
6093 case BPF_FUNC_sys_close:
6094 return &bpf_sys_close_proto;
6095 case BPF_FUNC_kallsyms_lookup_name:
6096 return &bpf_kallsyms_lookup_name_proto;
6097 default:
6098 return tracing_prog_func_proto(func_id, prog);
6099 }
6100 }
6101
6102 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6103 .get_func_proto = syscall_prog_func_proto,
6104 .is_valid_access = syscall_prog_is_valid_access,
6105 };
6106
6107 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6108 .test_run = bpf_prog_test_run_syscall,
6109 };
6110
6111 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6112 static int bpf_stats_handler(const struct ctl_table *table, int write,
6113 void *buffer, size_t *lenp, loff_t *ppos)
6114 {
6115 struct static_key *key = (struct static_key *)table->data;
6116 static int saved_val;
6117 int val, ret;
6118 struct ctl_table tmp = {
6119 .data = &val,
6120 .maxlen = sizeof(val),
6121 .mode = table->mode,
6122 .extra1 = SYSCTL_ZERO,
6123 .extra2 = SYSCTL_ONE,
6124 };
6125
6126 if (write && !capable(CAP_SYS_ADMIN))
6127 return -EPERM;
6128
6129 mutex_lock(&bpf_stats_enabled_mutex);
6130 val = saved_val;
6131 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6132 if (write && !ret && val != saved_val) {
6133 if (val)
6134 static_key_slow_inc(key);
6135 else
6136 static_key_slow_dec(key);
6137 saved_val = val;
6138 }
6139 mutex_unlock(&bpf_stats_enabled_mutex);
6140 return ret;
6141 }
6142
unpriv_ebpf_notify(int new_state)6143 void __weak unpriv_ebpf_notify(int new_state)
6144 {
6145 }
6146
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6147 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6148 void *buffer, size_t *lenp, loff_t *ppos)
6149 {
6150 int ret, unpriv_enable = *(int *)table->data;
6151 bool locked_state = unpriv_enable == 1;
6152 struct ctl_table tmp = *table;
6153
6154 if (write && !capable(CAP_SYS_ADMIN))
6155 return -EPERM;
6156
6157 tmp.data = &unpriv_enable;
6158 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6159 if (write && !ret) {
6160 if (locked_state && unpriv_enable != 1)
6161 return -EPERM;
6162 *(int *)table->data = unpriv_enable;
6163 }
6164
6165 if (write)
6166 unpriv_ebpf_notify(unpriv_enable);
6167
6168 return ret;
6169 }
6170
6171 static const struct ctl_table bpf_syscall_table[] = {
6172 {
6173 .procname = "unprivileged_bpf_disabled",
6174 .data = &sysctl_unprivileged_bpf_disabled,
6175 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
6176 .mode = 0644,
6177 .proc_handler = bpf_unpriv_handler,
6178 .extra1 = SYSCTL_ZERO,
6179 .extra2 = SYSCTL_TWO,
6180 },
6181 {
6182 .procname = "bpf_stats_enabled",
6183 .data = &bpf_stats_enabled_key.key,
6184 .mode = 0644,
6185 .proc_handler = bpf_stats_handler,
6186 },
6187 };
6188
bpf_syscall_sysctl_init(void)6189 static int __init bpf_syscall_sysctl_init(void)
6190 {
6191 register_sysctl_init("kernel", bpf_syscall_table);
6192 return 0;
6193 }
6194 late_initcall(bpf_syscall_sysctl_init);
6195 #endif /* CONFIG_SYSCTL */
6196