1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 */
4 #include <crypto/sha2.h>
5 #include <linux/bpf.h>
6 #include <linux/bpf-cgroup.h>
7 #include <linux/bpf_trace.h>
8 #include <linux/bpf_lirc.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bsearch.h>
11 #include <linux/btf.h>
12 #include <linux/syscalls.h>
13 #include <linux/slab.h>
14 #include <linux/sched/signal.h>
15 #include <linux/vmalloc.h>
16 #include <linux/mmzone.h>
17 #include <linux/anon_inodes.h>
18 #include <linux/fdtable.h>
19 #include <linux/file.h>
20 #include <linux/fs.h>
21 #include <linux/license.h>
22 #include <linux/filter.h>
23 #include <linux/kernel.h>
24 #include <linux/idr.h>
25 #include <linux/cred.h>
26 #include <linux/timekeeping.h>
27 #include <linux/ctype.h>
28 #include <linux/nospec.h>
29 #include <linux/audit.h>
30 #include <uapi/linux/btf.h>
31 #include <linux/pgtable.h>
32 #include <linux/bpf_lsm.h>
33 #include <linux/poll.h>
34 #include <linux/sort.h>
35 #include <linux/bpf-netns.h>
36 #include <linux/rcupdate_trace.h>
37 #include <linux/memcontrol.h>
38 #include <linux/trace_events.h>
39 #include <linux/tracepoint.h>
40 #include <linux/overflow.h>
41 #include <linux/cookie.h>
42 #include <linux/verification.h>
43
44 #include <net/netfilter/nf_bpf_link.h>
45 #include <net/netkit.h>
46 #include <net/tcx.h>
47
48 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
49 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
50 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
51 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
52 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
53 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
54 IS_FD_HASH(map))
55
56 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY)
57
58 DEFINE_PER_CPU(int, bpf_prog_active);
59 DEFINE_COOKIE(bpf_map_cookie);
60 static DEFINE_IDR(prog_idr);
61 static DEFINE_SPINLOCK(prog_idr_lock);
62 static DEFINE_IDR(map_idr);
63 static DEFINE_SPINLOCK(map_idr_lock);
64 static DEFINE_IDR(link_idr);
65 static DEFINE_SPINLOCK(link_idr_lock);
66
67 int sysctl_unprivileged_bpf_disabled __read_mostly =
68 IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
69
70 static const struct bpf_map_ops * const bpf_map_types[] = {
71 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
72 #define BPF_MAP_TYPE(_id, _ops) \
73 [_id] = &_ops,
74 #define BPF_LINK_TYPE(_id, _name)
75 #include <linux/bpf_types.h>
76 #undef BPF_PROG_TYPE
77 #undef BPF_MAP_TYPE
78 #undef BPF_LINK_TYPE
79 };
80
81 /*
82 * If we're handed a bigger struct than we know of, ensure all the unknown bits
83 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
84 * we don't know about yet.
85 *
86 * There is a ToCToU between this function call and the following
87 * copy_from_user() call. However, this is not a concern since this function is
88 * meant to be a future-proofing of bits.
89 */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)90 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
91 size_t expected_size,
92 size_t actual_size)
93 {
94 int res;
95
96 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
97 return -E2BIG;
98
99 if (actual_size <= expected_size)
100 return 0;
101
102 if (uaddr.is_kernel)
103 res = memchr_inv(uaddr.kernel + expected_size, 0,
104 actual_size - expected_size) == NULL;
105 else
106 res = check_zeroed_user(uaddr.user + expected_size,
107 actual_size - expected_size);
108 if (res < 0)
109 return res;
110 return res ? 0 : -E2BIG;
111 }
112
113 const struct bpf_map_ops bpf_map_offload_ops = {
114 .map_meta_equal = bpf_map_meta_equal,
115 .map_alloc = bpf_map_offload_map_alloc,
116 .map_free = bpf_map_offload_map_free,
117 .map_check_btf = map_check_no_btf,
118 .map_mem_usage = bpf_map_offload_map_mem_usage,
119 };
120
bpf_map_write_active_inc(struct bpf_map * map)121 static void bpf_map_write_active_inc(struct bpf_map *map)
122 {
123 atomic64_inc(&map->writecnt);
124 }
125
bpf_map_write_active_dec(struct bpf_map * map)126 static void bpf_map_write_active_dec(struct bpf_map *map)
127 {
128 atomic64_dec(&map->writecnt);
129 }
130
bpf_map_write_active(const struct bpf_map * map)131 bool bpf_map_write_active(const struct bpf_map *map)
132 {
133 return atomic64_read(&map->writecnt) != 0;
134 }
135
bpf_map_value_size(const struct bpf_map * map)136 static u32 bpf_map_value_size(const struct bpf_map *map)
137 {
138 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
139 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
140 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
141 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
142 return round_up(map->value_size, 8) * num_possible_cpus();
143 else if (IS_FD_MAP(map))
144 return sizeof(u32);
145 else
146 return map->value_size;
147 }
148
maybe_wait_bpf_programs(struct bpf_map * map)149 static void maybe_wait_bpf_programs(struct bpf_map *map)
150 {
151 /* Wait for any running non-sleepable BPF programs to complete so that
152 * userspace, when we return to it, knows that all non-sleepable
153 * programs that could be running use the new map value. For sleepable
154 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
155 * for the completions of these programs, but considering the waiting
156 * time can be very long and userspace may think it will hang forever,
157 * so don't handle sleepable BPF programs now.
158 */
159 if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
160 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
161 synchronize_rcu_expedited();
162 }
163
unpin_uptr_kaddr(void * kaddr)164 static void unpin_uptr_kaddr(void *kaddr)
165 {
166 if (kaddr)
167 unpin_user_page(virt_to_page(kaddr));
168 }
169
__bpf_obj_unpin_uptrs(struct btf_record * rec,u32 cnt,void * obj)170 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj)
171 {
172 const struct btf_field *field;
173 void **uptr_addr;
174 int i;
175
176 for (i = 0, field = rec->fields; i < cnt; i++, field++) {
177 if (field->type != BPF_UPTR)
178 continue;
179
180 uptr_addr = obj + field->offset;
181 unpin_uptr_kaddr(*uptr_addr);
182 }
183 }
184
bpf_obj_unpin_uptrs(struct btf_record * rec,void * obj)185 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj)
186 {
187 if (!btf_record_has_field(rec, BPF_UPTR))
188 return;
189
190 __bpf_obj_unpin_uptrs(rec, rec->cnt, obj);
191 }
192
bpf_obj_pin_uptrs(struct btf_record * rec,void * obj)193 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj)
194 {
195 const struct btf_field *field;
196 const struct btf_type *t;
197 unsigned long start, end;
198 struct page *page;
199 void **uptr_addr;
200 int i, err;
201
202 if (!btf_record_has_field(rec, BPF_UPTR))
203 return 0;
204
205 for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) {
206 if (field->type != BPF_UPTR)
207 continue;
208
209 uptr_addr = obj + field->offset;
210 start = *(unsigned long *)uptr_addr;
211 if (!start)
212 continue;
213
214 t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id);
215 /* t->size was checked for zero before */
216 if (check_add_overflow(start, t->size - 1, &end)) {
217 err = -EFAULT;
218 goto unpin_all;
219 }
220
221 /* The uptr's struct cannot span across two pages */
222 if ((start & PAGE_MASK) != (end & PAGE_MASK)) {
223 err = -EOPNOTSUPP;
224 goto unpin_all;
225 }
226
227 err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page);
228 if (err != 1)
229 goto unpin_all;
230
231 if (PageHighMem(page)) {
232 err = -EOPNOTSUPP;
233 unpin_user_page(page);
234 goto unpin_all;
235 }
236
237 *uptr_addr = page_address(page) + offset_in_page(start);
238 }
239
240 return 0;
241
242 unpin_all:
243 __bpf_obj_unpin_uptrs(rec, i, obj);
244 return err;
245 }
246
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)247 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
248 void *key, void *value, __u64 flags)
249 {
250 int err;
251
252 /* Need to create a kthread, thus must support schedule */
253 if (bpf_map_is_offloaded(map)) {
254 return bpf_map_offload_update_elem(map, key, value, flags);
255 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
256 map->map_type == BPF_MAP_TYPE_ARENA ||
257 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
258 return map->ops->map_update_elem(map, key, value, flags);
259 } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
260 map->map_type == BPF_MAP_TYPE_SOCKMAP) {
261 return sock_map_update_elem_sys(map, key, value, flags);
262 } else if (IS_FD_PROG_ARRAY(map)) {
263 return bpf_fd_array_map_update_elem(map, map_file, key, value,
264 flags);
265 }
266
267 bpf_disable_instrumentation();
268 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
269 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
270 err = bpf_percpu_hash_update(map, key, value, flags);
271 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
272 err = bpf_percpu_array_update(map, key, value, flags);
273 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
274 err = bpf_percpu_cgroup_storage_update(map, key, value,
275 flags);
276 } else if (IS_FD_ARRAY(map)) {
277 err = bpf_fd_array_map_update_elem(map, map_file, key, value,
278 flags);
279 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
280 err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
281 flags);
282 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
283 /* rcu_read_lock() is not needed */
284 err = bpf_fd_reuseport_array_update_elem(map, key, value,
285 flags);
286 } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
287 map->map_type == BPF_MAP_TYPE_STACK ||
288 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
289 err = map->ops->map_push_elem(map, value, flags);
290 } else {
291 err = bpf_obj_pin_uptrs(map->record, value);
292 if (!err) {
293 rcu_read_lock();
294 err = map->ops->map_update_elem(map, key, value, flags);
295 rcu_read_unlock();
296 if (err)
297 bpf_obj_unpin_uptrs(map->record, value);
298 }
299 }
300 bpf_enable_instrumentation();
301
302 return err;
303 }
304
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)305 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
306 __u64 flags)
307 {
308 void *ptr;
309 int err;
310
311 if (bpf_map_is_offloaded(map))
312 return bpf_map_offload_lookup_elem(map, key, value);
313
314 bpf_disable_instrumentation();
315 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
316 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
317 err = bpf_percpu_hash_copy(map, key, value);
318 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
319 err = bpf_percpu_array_copy(map, key, value);
320 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
321 err = bpf_percpu_cgroup_storage_copy(map, key, value);
322 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
323 err = bpf_stackmap_extract(map, key, value, false);
324 } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
325 err = bpf_fd_array_map_lookup_elem(map, key, value);
326 } else if (IS_FD_HASH(map)) {
327 err = bpf_fd_htab_map_lookup_elem(map, key, value);
328 } else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
329 err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
330 } else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
331 map->map_type == BPF_MAP_TYPE_STACK ||
332 map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
333 err = map->ops->map_peek_elem(map, value);
334 } else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
335 /* struct_ops map requires directly updating "value" */
336 err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
337 } else {
338 rcu_read_lock();
339 if (map->ops->map_lookup_elem_sys_only)
340 ptr = map->ops->map_lookup_elem_sys_only(map, key);
341 else
342 ptr = map->ops->map_lookup_elem(map, key);
343 if (IS_ERR(ptr)) {
344 err = PTR_ERR(ptr);
345 } else if (!ptr) {
346 err = -ENOENT;
347 } else {
348 err = 0;
349 if (flags & BPF_F_LOCK)
350 /* lock 'ptr' and copy everything but lock */
351 copy_map_value_locked(map, value, ptr, true);
352 else
353 copy_map_value(map, value, ptr);
354 /* mask lock and timer, since value wasn't zero inited */
355 check_and_init_map_value(map, value);
356 }
357 rcu_read_unlock();
358 }
359
360 bpf_enable_instrumentation();
361
362 return err;
363 }
364
365 /* Please, do not use this function outside from the map creation path
366 * (e.g. in map update path) without taking care of setting the active
367 * memory cgroup (see at bpf_map_kmalloc_node() for example).
368 */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)369 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
370 {
371 /* We really just want to fail instead of triggering OOM killer
372 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
373 * which is used for lower order allocation requests.
374 *
375 * It has been observed that higher order allocation requests done by
376 * vmalloc with __GFP_NORETRY being set might fail due to not trying
377 * to reclaim memory from the page cache, thus we set
378 * __GFP_RETRY_MAYFAIL to avoid such situations.
379 */
380
381 gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
382 unsigned int flags = 0;
383 unsigned long align = 1;
384 void *area;
385
386 if (size >= SIZE_MAX)
387 return NULL;
388
389 /* kmalloc()'ed memory can't be mmap()'ed */
390 if (mmapable) {
391 BUG_ON(!PAGE_ALIGNED(size));
392 align = SHMLBA;
393 flags = VM_USERMAP;
394 } else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
395 area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
396 numa_node);
397 if (area != NULL)
398 return area;
399 }
400
401 return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
402 gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
403 flags, numa_node, __builtin_return_address(0));
404 }
405
bpf_map_area_alloc(u64 size,int numa_node)406 void *bpf_map_area_alloc(u64 size, int numa_node)
407 {
408 return __bpf_map_area_alloc(size, numa_node, false);
409 }
410
bpf_map_area_mmapable_alloc(u64 size,int numa_node)411 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
412 {
413 return __bpf_map_area_alloc(size, numa_node, true);
414 }
415
bpf_map_area_free(void * area)416 void bpf_map_area_free(void *area)
417 {
418 kvfree(area);
419 }
420
bpf_map_flags_retain_permanent(u32 flags)421 static u32 bpf_map_flags_retain_permanent(u32 flags)
422 {
423 /* Some map creation flags are not tied to the map object but
424 * rather to the map fd instead, so they have no meaning upon
425 * map object inspection since multiple file descriptors with
426 * different (access) properties can exist here. Thus, given
427 * this has zero meaning for the map itself, lets clear these
428 * from here.
429 */
430 return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
431 }
432
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)433 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
434 {
435 map->map_type = attr->map_type;
436 map->key_size = attr->key_size;
437 map->value_size = attr->value_size;
438 map->max_entries = attr->max_entries;
439 map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
440 map->numa_node = bpf_map_attr_numa_node(attr);
441 map->map_extra = attr->map_extra;
442 }
443
bpf_map_alloc_id(struct bpf_map * map)444 static int bpf_map_alloc_id(struct bpf_map *map)
445 {
446 int id;
447
448 idr_preload(GFP_KERNEL);
449 spin_lock_bh(&map_idr_lock);
450 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
451 if (id > 0)
452 map->id = id;
453 spin_unlock_bh(&map_idr_lock);
454 idr_preload_end();
455
456 if (WARN_ON_ONCE(!id))
457 return -ENOSPC;
458
459 return id > 0 ? 0 : id;
460 }
461
bpf_map_free_id(struct bpf_map * map)462 void bpf_map_free_id(struct bpf_map *map)
463 {
464 unsigned long flags;
465
466 /* Offloaded maps are removed from the IDR store when their device
467 * disappears - even if someone holds an fd to them they are unusable,
468 * the memory is gone, all ops will fail; they are simply waiting for
469 * refcnt to drop to be freed.
470 */
471 if (!map->id)
472 return;
473
474 spin_lock_irqsave(&map_idr_lock, flags);
475
476 idr_remove(&map_idr, map->id);
477 map->id = 0;
478
479 spin_unlock_irqrestore(&map_idr_lock, flags);
480 }
481
482 #ifdef CONFIG_MEMCG
bpf_map_save_memcg(struct bpf_map * map)483 static void bpf_map_save_memcg(struct bpf_map *map)
484 {
485 /* Currently if a map is created by a process belonging to the root
486 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
487 * So we have to check map->objcg for being NULL each time it's
488 * being used.
489 */
490 if (memcg_bpf_enabled())
491 map->objcg = get_obj_cgroup_from_current();
492 }
493
bpf_map_release_memcg(struct bpf_map * map)494 static void bpf_map_release_memcg(struct bpf_map *map)
495 {
496 if (map->objcg)
497 obj_cgroup_put(map->objcg);
498 }
499
bpf_map_get_memcg(const struct bpf_map * map)500 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
501 {
502 if (map->objcg)
503 return get_mem_cgroup_from_objcg(map->objcg);
504
505 return root_mem_cgroup;
506 }
507
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)508 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
509 int node)
510 {
511 struct mem_cgroup *memcg, *old_memcg;
512 void *ptr;
513
514 memcg = bpf_map_get_memcg(map);
515 old_memcg = set_active_memcg(memcg);
516 ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
517 set_active_memcg(old_memcg);
518 mem_cgroup_put(memcg);
519
520 return ptr;
521 }
522
bpf_map_kmalloc_nolock(const struct bpf_map * map,size_t size,gfp_t flags,int node)523 void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags,
524 int node)
525 {
526 struct mem_cgroup *memcg, *old_memcg;
527 void *ptr;
528
529 memcg = bpf_map_get_memcg(map);
530 old_memcg = set_active_memcg(memcg);
531 ptr = kmalloc_nolock(size, flags | __GFP_ACCOUNT, node);
532 set_active_memcg(old_memcg);
533 mem_cgroup_put(memcg);
534
535 return ptr;
536 }
537
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)538 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
539 {
540 struct mem_cgroup *memcg, *old_memcg;
541 void *ptr;
542
543 memcg = bpf_map_get_memcg(map);
544 old_memcg = set_active_memcg(memcg);
545 ptr = kzalloc(size, flags | __GFP_ACCOUNT);
546 set_active_memcg(old_memcg);
547 mem_cgroup_put(memcg);
548
549 return ptr;
550 }
551
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)552 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
553 gfp_t flags)
554 {
555 struct mem_cgroup *memcg, *old_memcg;
556 void *ptr;
557
558 memcg = bpf_map_get_memcg(map);
559 old_memcg = set_active_memcg(memcg);
560 ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
561 set_active_memcg(old_memcg);
562 mem_cgroup_put(memcg);
563
564 return ptr;
565 }
566
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)567 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
568 size_t align, gfp_t flags)
569 {
570 struct mem_cgroup *memcg, *old_memcg;
571 void __percpu *ptr;
572
573 memcg = bpf_map_get_memcg(map);
574 old_memcg = set_active_memcg(memcg);
575 ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
576 set_active_memcg(old_memcg);
577 mem_cgroup_put(memcg);
578
579 return ptr;
580 }
581
582 #else
bpf_map_save_memcg(struct bpf_map * map)583 static void bpf_map_save_memcg(struct bpf_map *map)
584 {
585 }
586
bpf_map_release_memcg(struct bpf_map * map)587 static void bpf_map_release_memcg(struct bpf_map *map)
588 {
589 }
590 #endif
591
can_alloc_pages(void)592 static bool can_alloc_pages(void)
593 {
594 return preempt_count() == 0 && !irqs_disabled() &&
595 !IS_ENABLED(CONFIG_PREEMPT_RT);
596 }
597
__bpf_alloc_page(int nid)598 static struct page *__bpf_alloc_page(int nid)
599 {
600 if (!can_alloc_pages())
601 return alloc_pages_nolock(__GFP_ACCOUNT, nid, 0);
602
603 return alloc_pages_node(nid,
604 GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
605 | __GFP_NOWARN,
606 0);
607 }
608
bpf_map_alloc_pages(const struct bpf_map * map,int nid,unsigned long nr_pages,struct page ** pages)609 int bpf_map_alloc_pages(const struct bpf_map *map, int nid,
610 unsigned long nr_pages, struct page **pages)
611 {
612 unsigned long i, j;
613 struct page *pg;
614 int ret = 0;
615 #ifdef CONFIG_MEMCG
616 struct mem_cgroup *memcg, *old_memcg;
617
618 memcg = bpf_map_get_memcg(map);
619 old_memcg = set_active_memcg(memcg);
620 #endif
621 for (i = 0; i < nr_pages; i++) {
622 pg = __bpf_alloc_page(nid);
623
624 if (pg) {
625 pages[i] = pg;
626 continue;
627 }
628 for (j = 0; j < i; j++)
629 free_pages_nolock(pages[j], 0);
630 ret = -ENOMEM;
631 break;
632 }
633
634 #ifdef CONFIG_MEMCG
635 set_active_memcg(old_memcg);
636 mem_cgroup_put(memcg);
637 #endif
638 return ret;
639 }
640
641
btf_field_cmp(const void * a,const void * b)642 static int btf_field_cmp(const void *a, const void *b)
643 {
644 const struct btf_field *f1 = a, *f2 = b;
645
646 if (f1->offset < f2->offset)
647 return -1;
648 else if (f1->offset > f2->offset)
649 return 1;
650 return 0;
651 }
652
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)653 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
654 u32 field_mask)
655 {
656 struct btf_field *field;
657
658 if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
659 return NULL;
660 field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
661 if (!field || !(field->type & field_mask))
662 return NULL;
663 return field;
664 }
665
btf_record_free(struct btf_record * rec)666 void btf_record_free(struct btf_record *rec)
667 {
668 int i;
669
670 if (IS_ERR_OR_NULL(rec))
671 return;
672 for (i = 0; i < rec->cnt; i++) {
673 switch (rec->fields[i].type) {
674 case BPF_KPTR_UNREF:
675 case BPF_KPTR_REF:
676 case BPF_KPTR_PERCPU:
677 case BPF_UPTR:
678 if (rec->fields[i].kptr.module)
679 module_put(rec->fields[i].kptr.module);
680 if (btf_is_kernel(rec->fields[i].kptr.btf))
681 btf_put(rec->fields[i].kptr.btf);
682 break;
683 case BPF_LIST_HEAD:
684 case BPF_LIST_NODE:
685 case BPF_RB_ROOT:
686 case BPF_RB_NODE:
687 case BPF_SPIN_LOCK:
688 case BPF_RES_SPIN_LOCK:
689 case BPF_TIMER:
690 case BPF_REFCOUNT:
691 case BPF_WORKQUEUE:
692 case BPF_TASK_WORK:
693 /* Nothing to release */
694 break;
695 default:
696 WARN_ON_ONCE(1);
697 continue;
698 }
699 }
700 kfree(rec);
701 }
702
bpf_map_free_record(struct bpf_map * map)703 void bpf_map_free_record(struct bpf_map *map)
704 {
705 btf_record_free(map->record);
706 map->record = NULL;
707 }
708
btf_record_dup(const struct btf_record * rec)709 struct btf_record *btf_record_dup(const struct btf_record *rec)
710 {
711 const struct btf_field *fields;
712 struct btf_record *new_rec;
713 int ret, size, i;
714
715 if (IS_ERR_OR_NULL(rec))
716 return NULL;
717 size = struct_size(rec, fields, rec->cnt);
718 new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
719 if (!new_rec)
720 return ERR_PTR(-ENOMEM);
721 /* Do a deep copy of the btf_record */
722 fields = rec->fields;
723 new_rec->cnt = 0;
724 for (i = 0; i < rec->cnt; i++) {
725 switch (fields[i].type) {
726 case BPF_KPTR_UNREF:
727 case BPF_KPTR_REF:
728 case BPF_KPTR_PERCPU:
729 case BPF_UPTR:
730 if (btf_is_kernel(fields[i].kptr.btf))
731 btf_get(fields[i].kptr.btf);
732 if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
733 ret = -ENXIO;
734 goto free;
735 }
736 break;
737 case BPF_LIST_HEAD:
738 case BPF_LIST_NODE:
739 case BPF_RB_ROOT:
740 case BPF_RB_NODE:
741 case BPF_SPIN_LOCK:
742 case BPF_RES_SPIN_LOCK:
743 case BPF_TIMER:
744 case BPF_REFCOUNT:
745 case BPF_WORKQUEUE:
746 case BPF_TASK_WORK:
747 /* Nothing to acquire */
748 break;
749 default:
750 ret = -EFAULT;
751 WARN_ON_ONCE(1);
752 goto free;
753 }
754 new_rec->cnt++;
755 }
756 return new_rec;
757 free:
758 btf_record_free(new_rec);
759 return ERR_PTR(ret);
760 }
761
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)762 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
763 {
764 bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
765 int size;
766
767 if (!a_has_fields && !b_has_fields)
768 return true;
769 if (a_has_fields != b_has_fields)
770 return false;
771 if (rec_a->cnt != rec_b->cnt)
772 return false;
773 size = struct_size(rec_a, fields, rec_a->cnt);
774 /* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
775 * members are zeroed out. So memcmp is safe to do without worrying
776 * about padding/unused fields.
777 *
778 * While spin_lock, timer, and kptr have no relation to map BTF,
779 * list_head metadata is specific to map BTF, the btf and value_rec
780 * members in particular. btf is the map BTF, while value_rec points to
781 * btf_record in that map BTF.
782 *
783 * So while by default, we don't rely on the map BTF (which the records
784 * were parsed from) matching for both records, which is not backwards
785 * compatible, in case list_head is part of it, we implicitly rely on
786 * that by way of depending on memcmp succeeding for it.
787 */
788 return !memcmp(rec_a, rec_b, size);
789 }
790
bpf_obj_free_timer(const struct btf_record * rec,void * obj)791 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
792 {
793 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
794 return;
795 bpf_timer_cancel_and_free(obj + rec->timer_off);
796 }
797
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)798 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
799 {
800 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
801 return;
802 bpf_wq_cancel_and_free(obj + rec->wq_off);
803 }
804
bpf_obj_free_task_work(const struct btf_record * rec,void * obj)805 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj)
806 {
807 if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK)))
808 return;
809 bpf_task_work_cancel_and_free(obj + rec->task_work_off);
810 }
811
bpf_obj_free_fields(const struct btf_record * rec,void * obj)812 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
813 {
814 const struct btf_field *fields;
815 int i;
816
817 if (IS_ERR_OR_NULL(rec))
818 return;
819 fields = rec->fields;
820 for (i = 0; i < rec->cnt; i++) {
821 struct btf_struct_meta *pointee_struct_meta;
822 const struct btf_field *field = &fields[i];
823 void *field_ptr = obj + field->offset;
824 void *xchgd_field;
825
826 switch (fields[i].type) {
827 case BPF_SPIN_LOCK:
828 case BPF_RES_SPIN_LOCK:
829 break;
830 case BPF_TIMER:
831 bpf_timer_cancel_and_free(field_ptr);
832 break;
833 case BPF_WORKQUEUE:
834 bpf_wq_cancel_and_free(field_ptr);
835 break;
836 case BPF_TASK_WORK:
837 bpf_task_work_cancel_and_free(field_ptr);
838 break;
839 case BPF_KPTR_UNREF:
840 WRITE_ONCE(*(u64 *)field_ptr, 0);
841 break;
842 case BPF_KPTR_REF:
843 case BPF_KPTR_PERCPU:
844 xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
845 if (!xchgd_field)
846 break;
847
848 if (!btf_is_kernel(field->kptr.btf)) {
849 pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
850 field->kptr.btf_id);
851 __bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
852 pointee_struct_meta->record : NULL,
853 fields[i].type == BPF_KPTR_PERCPU);
854 } else {
855 field->kptr.dtor(xchgd_field);
856 }
857 break;
858 case BPF_UPTR:
859 /* The caller ensured that no one is using the uptr */
860 unpin_uptr_kaddr(*(void **)field_ptr);
861 break;
862 case BPF_LIST_HEAD:
863 if (WARN_ON_ONCE(rec->spin_lock_off < 0))
864 continue;
865 bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
866 break;
867 case BPF_RB_ROOT:
868 if (WARN_ON_ONCE(rec->spin_lock_off < 0))
869 continue;
870 bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
871 break;
872 case BPF_LIST_NODE:
873 case BPF_RB_NODE:
874 case BPF_REFCOUNT:
875 break;
876 default:
877 WARN_ON_ONCE(1);
878 continue;
879 }
880 }
881 }
882
bpf_map_free(struct bpf_map * map)883 static void bpf_map_free(struct bpf_map *map)
884 {
885 struct btf_record *rec = map->record;
886 struct btf *btf = map->btf;
887
888 /* implementation dependent freeing. Disabling migration to simplify
889 * the free of values or special fields allocated from bpf memory
890 * allocator.
891 */
892 kfree(map->excl_prog_sha);
893 migrate_disable();
894 map->ops->map_free(map);
895 migrate_enable();
896
897 /* Delay freeing of btf_record for maps, as map_free
898 * callback usually needs access to them. It is better to do it here
899 * than require each callback to do the free itself manually.
900 *
901 * Note that the btf_record stashed in map->inner_map_meta->record was
902 * already freed using the map_free callback for map in map case which
903 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
904 * template bpf_map struct used during verification.
905 */
906 btf_record_free(rec);
907 /* Delay freeing of btf for maps, as map_free callback may need
908 * struct_meta info which will be freed with btf_put().
909 */
910 btf_put(btf);
911 }
912
913 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)914 static void bpf_map_free_deferred(struct work_struct *work)
915 {
916 struct bpf_map *map = container_of(work, struct bpf_map, work);
917
918 security_bpf_map_free(map);
919 bpf_map_release_memcg(map);
920 bpf_map_owner_free(map);
921 bpf_map_free(map);
922 }
923
bpf_map_put_uref(struct bpf_map * map)924 static void bpf_map_put_uref(struct bpf_map *map)
925 {
926 if (atomic64_dec_and_test(&map->usercnt)) {
927 if (map->ops->map_release_uref)
928 map->ops->map_release_uref(map);
929 }
930 }
931
bpf_map_free_in_work(struct bpf_map * map)932 static void bpf_map_free_in_work(struct bpf_map *map)
933 {
934 INIT_WORK(&map->work, bpf_map_free_deferred);
935 /* Avoid spawning kworkers, since they all might contend
936 * for the same mutex like slab_mutex.
937 */
938 queue_work(system_dfl_wq, &map->work);
939 }
940
bpf_map_free_rcu_gp(struct rcu_head * rcu)941 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
942 {
943 bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
944 }
945
bpf_map_free_mult_rcu_gp(struct rcu_head * rcu)946 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
947 {
948 if (rcu_trace_implies_rcu_gp())
949 bpf_map_free_rcu_gp(rcu);
950 else
951 call_rcu(rcu, bpf_map_free_rcu_gp);
952 }
953
954 /* decrement map refcnt and schedule it for freeing via workqueue
955 * (underlying map implementation ops->map_free() might sleep)
956 */
bpf_map_put(struct bpf_map * map)957 void bpf_map_put(struct bpf_map *map)
958 {
959 if (atomic64_dec_and_test(&map->refcnt)) {
960 /* bpf_map_free_id() must be called first */
961 bpf_map_free_id(map);
962
963 WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
964 if (READ_ONCE(map->free_after_mult_rcu_gp))
965 call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
966 else if (READ_ONCE(map->free_after_rcu_gp))
967 call_rcu(&map->rcu, bpf_map_free_rcu_gp);
968 else
969 bpf_map_free_in_work(map);
970 }
971 }
972 EXPORT_SYMBOL_GPL(bpf_map_put);
973
bpf_map_put_with_uref(struct bpf_map * map)974 void bpf_map_put_with_uref(struct bpf_map *map)
975 {
976 bpf_map_put_uref(map);
977 bpf_map_put(map);
978 }
979
bpf_map_release(struct inode * inode,struct file * filp)980 static int bpf_map_release(struct inode *inode, struct file *filp)
981 {
982 struct bpf_map *map = filp->private_data;
983
984 if (map->ops->map_release)
985 map->ops->map_release(map, filp);
986
987 bpf_map_put_with_uref(map);
988 return 0;
989 }
990
map_get_sys_perms(struct bpf_map * map,struct fd f)991 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
992 {
993 fmode_t mode = fd_file(f)->f_mode;
994
995 /* Our file permissions may have been overridden by global
996 * map permissions facing syscall side.
997 */
998 if (READ_ONCE(map->frozen))
999 mode &= ~FMODE_CAN_WRITE;
1000 return mode;
1001 }
1002
1003 #ifdef CONFIG_PROC_FS
1004 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)1005 static u64 bpf_map_memory_usage(const struct bpf_map *map)
1006 {
1007 return map->ops->map_mem_usage(map);
1008 }
1009
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)1010 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
1011 {
1012 struct bpf_map *map = filp->private_data;
1013 u32 type = 0, jited = 0;
1014
1015 spin_lock(&map->owner_lock);
1016 if (map->owner) {
1017 type = map->owner->type;
1018 jited = map->owner->jited;
1019 }
1020 spin_unlock(&map->owner_lock);
1021
1022 seq_printf(m,
1023 "map_type:\t%u\n"
1024 "key_size:\t%u\n"
1025 "value_size:\t%u\n"
1026 "max_entries:\t%u\n"
1027 "map_flags:\t%#x\n"
1028 "map_extra:\t%#llx\n"
1029 "memlock:\t%llu\n"
1030 "map_id:\t%u\n"
1031 "frozen:\t%u\n",
1032 map->map_type,
1033 map->key_size,
1034 map->value_size,
1035 map->max_entries,
1036 map->map_flags,
1037 (unsigned long long)map->map_extra,
1038 bpf_map_memory_usage(map),
1039 map->id,
1040 READ_ONCE(map->frozen));
1041 if (type) {
1042 seq_printf(m, "owner_prog_type:\t%u\n", type);
1043 seq_printf(m, "owner_jited:\t%u\n", jited);
1044 }
1045 }
1046 #endif
1047
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)1048 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
1049 loff_t *ppos)
1050 {
1051 /* We need this handler such that alloc_file() enables
1052 * f_mode with FMODE_CAN_READ.
1053 */
1054 return -EINVAL;
1055 }
1056
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1057 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1058 size_t siz, loff_t *ppos)
1059 {
1060 /* We need this handler such that alloc_file() enables
1061 * f_mode with FMODE_CAN_WRITE.
1062 */
1063 return -EINVAL;
1064 }
1065
1066 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1067 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1068 {
1069 struct bpf_map *map = vma->vm_file->private_data;
1070
1071 if (vma->vm_flags & VM_MAYWRITE)
1072 bpf_map_write_active_inc(map);
1073 }
1074
1075 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1076 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1077 {
1078 struct bpf_map *map = vma->vm_file->private_data;
1079
1080 if (vma->vm_flags & VM_MAYWRITE)
1081 bpf_map_write_active_dec(map);
1082 }
1083
1084 static const struct vm_operations_struct bpf_map_default_vmops = {
1085 .open = bpf_map_mmap_open,
1086 .close = bpf_map_mmap_close,
1087 };
1088
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1089 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1090 {
1091 struct bpf_map *map = filp->private_data;
1092 int err = 0;
1093
1094 if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1095 return -ENOTSUPP;
1096
1097 if (!(vma->vm_flags & VM_SHARED))
1098 return -EINVAL;
1099
1100 mutex_lock(&map->freeze_mutex);
1101
1102 if (vma->vm_flags & VM_WRITE) {
1103 if (map->frozen) {
1104 err = -EPERM;
1105 goto out;
1106 }
1107 /* map is meant to be read-only, so do not allow mapping as
1108 * writable, because it's possible to leak a writable page
1109 * reference and allows user-space to still modify it after
1110 * freezing, while verifier will assume contents do not change
1111 */
1112 if (map->map_flags & BPF_F_RDONLY_PROG) {
1113 err = -EACCES;
1114 goto out;
1115 }
1116 bpf_map_write_active_inc(map);
1117 }
1118 out:
1119 mutex_unlock(&map->freeze_mutex);
1120 if (err)
1121 return err;
1122
1123 /* set default open/close callbacks */
1124 vma->vm_ops = &bpf_map_default_vmops;
1125 vma->vm_private_data = map;
1126 vm_flags_clear(vma, VM_MAYEXEC);
1127 /* If mapping is read-only, then disallow potentially re-mapping with
1128 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1129 * means that as far as BPF map's memory-mapped VMAs are concerned,
1130 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1131 * both should be set, so we can forget about VM_MAYWRITE and always
1132 * check just VM_WRITE
1133 */
1134 if (!(vma->vm_flags & VM_WRITE))
1135 vm_flags_clear(vma, VM_MAYWRITE);
1136
1137 err = map->ops->map_mmap(map, vma);
1138 if (err) {
1139 if (vma->vm_flags & VM_WRITE)
1140 bpf_map_write_active_dec(map);
1141 }
1142
1143 return err;
1144 }
1145
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1146 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1147 {
1148 struct bpf_map *map = filp->private_data;
1149
1150 if (map->ops->map_poll)
1151 return map->ops->map_poll(map, filp, pts);
1152
1153 return EPOLLERR;
1154 }
1155
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1156 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1157 unsigned long len, unsigned long pgoff,
1158 unsigned long flags)
1159 {
1160 struct bpf_map *map = filp->private_data;
1161
1162 if (map->ops->map_get_unmapped_area)
1163 return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1164 #ifdef CONFIG_MMU
1165 return mm_get_unmapped_area(filp, addr, len, pgoff, flags);
1166 #else
1167 return addr;
1168 #endif
1169 }
1170
1171 const struct file_operations bpf_map_fops = {
1172 #ifdef CONFIG_PROC_FS
1173 .show_fdinfo = bpf_map_show_fdinfo,
1174 #endif
1175 .release = bpf_map_release,
1176 .read = bpf_dummy_read,
1177 .write = bpf_dummy_write,
1178 .mmap = bpf_map_mmap,
1179 .poll = bpf_map_poll,
1180 .get_unmapped_area = bpf_get_unmapped_area,
1181 };
1182
bpf_map_new_fd(struct bpf_map * map,int flags)1183 int bpf_map_new_fd(struct bpf_map *map, int flags)
1184 {
1185 int ret;
1186
1187 ret = security_bpf_map(map, OPEN_FMODE(flags));
1188 if (ret < 0)
1189 return ret;
1190
1191 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1192 flags | O_CLOEXEC);
1193 }
1194
bpf_get_file_flag(int flags)1195 int bpf_get_file_flag(int flags)
1196 {
1197 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1198 return -EINVAL;
1199 if (flags & BPF_F_RDONLY)
1200 return O_RDONLY;
1201 if (flags & BPF_F_WRONLY)
1202 return O_WRONLY;
1203 return O_RDWR;
1204 }
1205
1206 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1207 #define CHECK_ATTR(CMD) \
1208 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1209 sizeof(attr->CMD##_LAST_FIELD), 0, \
1210 sizeof(*attr) - \
1211 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1212 sizeof(attr->CMD##_LAST_FIELD)) != NULL
1213
1214 /* dst and src must have at least "size" number of bytes.
1215 * Return strlen on success and < 0 on error.
1216 */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1217 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1218 {
1219 const char *end = src + size;
1220 const char *orig_src = src;
1221
1222 memset(dst, 0, size);
1223 /* Copy all isalnum(), '_' and '.' chars. */
1224 while (src < end && *src) {
1225 if (!isalnum(*src) &&
1226 *src != '_' && *src != '.')
1227 return -EINVAL;
1228 *dst++ = *src++;
1229 }
1230
1231 /* No '\0' found in "size" number of bytes */
1232 if (src == end)
1233 return -EINVAL;
1234
1235 return src - orig_src;
1236 }
1237 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy);
1238
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)1239 int map_check_no_btf(const struct bpf_map *map,
1240 const struct btf *btf,
1241 const struct btf_type *key_type,
1242 const struct btf_type *value_type)
1243 {
1244 return -ENOTSUPP;
1245 }
1246
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1247 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1248 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1249 {
1250 const struct btf_type *key_type, *value_type;
1251 u32 key_size, value_size;
1252 int ret = 0;
1253
1254 /* Some maps allow key to be unspecified. */
1255 if (btf_key_id) {
1256 key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1257 if (!key_type || key_size != map->key_size)
1258 return -EINVAL;
1259 } else {
1260 key_type = btf_type_by_id(btf, 0);
1261 if (!map->ops->map_check_btf)
1262 return -EINVAL;
1263 }
1264
1265 value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1266 if (!value_type || value_size != map->value_size)
1267 return -EINVAL;
1268
1269 map->record = btf_parse_fields(btf, value_type,
1270 BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1271 BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR |
1272 BPF_TASK_WORK,
1273 map->value_size);
1274 if (!IS_ERR_OR_NULL(map->record)) {
1275 int i;
1276
1277 if (!bpf_token_capable(token, CAP_BPF)) {
1278 ret = -EPERM;
1279 goto free_map_tab;
1280 }
1281 if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1282 ret = -EACCES;
1283 goto free_map_tab;
1284 }
1285 for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1286 switch (map->record->field_mask & (1 << i)) {
1287 case 0:
1288 continue;
1289 case BPF_SPIN_LOCK:
1290 case BPF_RES_SPIN_LOCK:
1291 if (map->map_type != BPF_MAP_TYPE_HASH &&
1292 map->map_type != BPF_MAP_TYPE_ARRAY &&
1293 map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1294 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1295 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1296 map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1297 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1298 ret = -EOPNOTSUPP;
1299 goto free_map_tab;
1300 }
1301 break;
1302 case BPF_TIMER:
1303 case BPF_WORKQUEUE:
1304 case BPF_TASK_WORK:
1305 if (map->map_type != BPF_MAP_TYPE_HASH &&
1306 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1307 map->map_type != BPF_MAP_TYPE_ARRAY) {
1308 ret = -EOPNOTSUPP;
1309 goto free_map_tab;
1310 }
1311 break;
1312 case BPF_KPTR_UNREF:
1313 case BPF_KPTR_REF:
1314 case BPF_KPTR_PERCPU:
1315 case BPF_REFCOUNT:
1316 if (map->map_type != BPF_MAP_TYPE_HASH &&
1317 map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1318 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1319 map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1320 map->map_type != BPF_MAP_TYPE_ARRAY &&
1321 map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1322 map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1323 map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1324 map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1325 map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1326 ret = -EOPNOTSUPP;
1327 goto free_map_tab;
1328 }
1329 break;
1330 case BPF_UPTR:
1331 if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1332 ret = -EOPNOTSUPP;
1333 goto free_map_tab;
1334 }
1335 break;
1336 case BPF_LIST_HEAD:
1337 case BPF_RB_ROOT:
1338 if (map->map_type != BPF_MAP_TYPE_HASH &&
1339 map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1340 map->map_type != BPF_MAP_TYPE_ARRAY) {
1341 ret = -EOPNOTSUPP;
1342 goto free_map_tab;
1343 }
1344 break;
1345 default:
1346 /* Fail if map_type checks are missing for a field type */
1347 ret = -EOPNOTSUPP;
1348 goto free_map_tab;
1349 }
1350 }
1351 }
1352
1353 ret = btf_check_and_fixup_fields(btf, map->record);
1354 if (ret < 0)
1355 goto free_map_tab;
1356
1357 if (map->ops->map_check_btf) {
1358 ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1359 if (ret < 0)
1360 goto free_map_tab;
1361 }
1362
1363 return ret;
1364 free_map_tab:
1365 bpf_map_free_record(map);
1366 return ret;
1367 }
1368
bpf_net_capable(void)1369 static bool bpf_net_capable(void)
1370 {
1371 return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
1372 }
1373
1374 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size
1375 /* called via syscall */
map_create(union bpf_attr * attr,bpfptr_t uattr)1376 static int map_create(union bpf_attr *attr, bpfptr_t uattr)
1377 {
1378 const struct bpf_map_ops *ops;
1379 struct bpf_token *token = NULL;
1380 int numa_node = bpf_map_attr_numa_node(attr);
1381 u32 map_type = attr->map_type;
1382 struct bpf_map *map;
1383 bool token_flag;
1384 int f_flags;
1385 int err;
1386
1387 err = CHECK_ATTR(BPF_MAP_CREATE);
1388 if (err)
1389 return -EINVAL;
1390
1391 /* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1392 * to avoid per-map type checks tripping on unknown flag
1393 */
1394 token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1395 attr->map_flags &= ~BPF_F_TOKEN_FD;
1396
1397 if (attr->btf_vmlinux_value_type_id) {
1398 if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1399 attr->btf_key_type_id || attr->btf_value_type_id)
1400 return -EINVAL;
1401 } else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1402 return -EINVAL;
1403 }
1404
1405 if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1406 attr->map_type != BPF_MAP_TYPE_ARENA &&
1407 attr->map_extra != 0)
1408 return -EINVAL;
1409
1410 f_flags = bpf_get_file_flag(attr->map_flags);
1411 if (f_flags < 0)
1412 return f_flags;
1413
1414 if (numa_node != NUMA_NO_NODE &&
1415 ((unsigned int)numa_node >= nr_node_ids ||
1416 !node_online(numa_node)))
1417 return -EINVAL;
1418
1419 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1420 map_type = attr->map_type;
1421 if (map_type >= ARRAY_SIZE(bpf_map_types))
1422 return -EINVAL;
1423 map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1424 ops = bpf_map_types[map_type];
1425 if (!ops)
1426 return -EINVAL;
1427
1428 if (ops->map_alloc_check) {
1429 err = ops->map_alloc_check(attr);
1430 if (err)
1431 return err;
1432 }
1433 if (attr->map_ifindex)
1434 ops = &bpf_map_offload_ops;
1435 if (!ops->map_mem_usage)
1436 return -EINVAL;
1437
1438 if (token_flag) {
1439 token = bpf_token_get_from_fd(attr->map_token_fd);
1440 if (IS_ERR(token))
1441 return PTR_ERR(token);
1442
1443 /* if current token doesn't grant map creation permissions,
1444 * then we can't use this token, so ignore it and rely on
1445 * system-wide capabilities checks
1446 */
1447 if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1448 !bpf_token_allow_map_type(token, attr->map_type)) {
1449 bpf_token_put(token);
1450 token = NULL;
1451 }
1452 }
1453
1454 err = -EPERM;
1455
1456 /* Intent here is for unprivileged_bpf_disabled to block BPF map
1457 * creation for unprivileged users; other actions depend
1458 * on fd availability and access to bpffs, so are dependent on
1459 * object creation success. Even with unprivileged BPF disabled,
1460 * capability checks are still carried out.
1461 */
1462 if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1463 goto put_token;
1464
1465 /* check privileged map type permissions */
1466 switch (map_type) {
1467 case BPF_MAP_TYPE_ARRAY:
1468 case BPF_MAP_TYPE_PERCPU_ARRAY:
1469 case BPF_MAP_TYPE_PROG_ARRAY:
1470 case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1471 case BPF_MAP_TYPE_CGROUP_ARRAY:
1472 case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1473 case BPF_MAP_TYPE_HASH:
1474 case BPF_MAP_TYPE_PERCPU_HASH:
1475 case BPF_MAP_TYPE_HASH_OF_MAPS:
1476 case BPF_MAP_TYPE_RINGBUF:
1477 case BPF_MAP_TYPE_USER_RINGBUF:
1478 case BPF_MAP_TYPE_CGROUP_STORAGE:
1479 case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1480 /* unprivileged */
1481 break;
1482 case BPF_MAP_TYPE_SK_STORAGE:
1483 case BPF_MAP_TYPE_INODE_STORAGE:
1484 case BPF_MAP_TYPE_TASK_STORAGE:
1485 case BPF_MAP_TYPE_CGRP_STORAGE:
1486 case BPF_MAP_TYPE_BLOOM_FILTER:
1487 case BPF_MAP_TYPE_LPM_TRIE:
1488 case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1489 case BPF_MAP_TYPE_STACK_TRACE:
1490 case BPF_MAP_TYPE_QUEUE:
1491 case BPF_MAP_TYPE_STACK:
1492 case BPF_MAP_TYPE_LRU_HASH:
1493 case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1494 case BPF_MAP_TYPE_STRUCT_OPS:
1495 case BPF_MAP_TYPE_CPUMAP:
1496 case BPF_MAP_TYPE_ARENA:
1497 case BPF_MAP_TYPE_INSN_ARRAY:
1498 if (!bpf_token_capable(token, CAP_BPF))
1499 goto put_token;
1500 break;
1501 case BPF_MAP_TYPE_SOCKMAP:
1502 case BPF_MAP_TYPE_SOCKHASH:
1503 case BPF_MAP_TYPE_DEVMAP:
1504 case BPF_MAP_TYPE_DEVMAP_HASH:
1505 case BPF_MAP_TYPE_XSKMAP:
1506 if (!bpf_token_capable(token, CAP_NET_ADMIN))
1507 goto put_token;
1508 break;
1509 default:
1510 WARN(1, "unsupported map type %d", map_type);
1511 goto put_token;
1512 }
1513
1514 map = ops->map_alloc(attr);
1515 if (IS_ERR(map)) {
1516 err = PTR_ERR(map);
1517 goto put_token;
1518 }
1519 map->ops = ops;
1520 map->map_type = map_type;
1521
1522 err = bpf_obj_name_cpy(map->name, attr->map_name,
1523 sizeof(attr->map_name));
1524 if (err < 0)
1525 goto free_map;
1526
1527 preempt_disable();
1528 map->cookie = gen_cookie_next(&bpf_map_cookie);
1529 preempt_enable();
1530
1531 atomic64_set(&map->refcnt, 1);
1532 atomic64_set(&map->usercnt, 1);
1533 mutex_init(&map->freeze_mutex);
1534 spin_lock_init(&map->owner_lock);
1535
1536 if (attr->btf_key_type_id || attr->btf_value_type_id ||
1537 /* Even the map's value is a kernel's struct,
1538 * the bpf_prog.o must have BTF to begin with
1539 * to figure out the corresponding kernel's
1540 * counter part. Thus, attr->btf_fd has
1541 * to be valid also.
1542 */
1543 attr->btf_vmlinux_value_type_id) {
1544 struct btf *btf;
1545
1546 btf = btf_get_by_fd(attr->btf_fd);
1547 if (IS_ERR(btf)) {
1548 err = PTR_ERR(btf);
1549 goto free_map;
1550 }
1551 if (btf_is_kernel(btf)) {
1552 btf_put(btf);
1553 err = -EACCES;
1554 goto free_map;
1555 }
1556 map->btf = btf;
1557
1558 if (attr->btf_value_type_id) {
1559 err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1560 attr->btf_value_type_id);
1561 if (err)
1562 goto free_map;
1563 }
1564
1565 map->btf_key_type_id = attr->btf_key_type_id;
1566 map->btf_value_type_id = attr->btf_value_type_id;
1567 map->btf_vmlinux_value_type_id =
1568 attr->btf_vmlinux_value_type_id;
1569 }
1570
1571 if (attr->excl_prog_hash) {
1572 bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel);
1573
1574 if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) {
1575 err = -EINVAL;
1576 goto free_map;
1577 }
1578
1579 map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
1580 if (!map->excl_prog_sha) {
1581 err = -ENOMEM;
1582 goto free_map;
1583 }
1584
1585 if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) {
1586 err = -EFAULT;
1587 goto free_map;
1588 }
1589 } else if (attr->excl_prog_hash_size) {
1590 err = -EINVAL;
1591 goto free_map;
1592 }
1593
1594 err = security_bpf_map_create(map, attr, token, uattr.is_kernel);
1595 if (err)
1596 goto free_map_sec;
1597
1598 err = bpf_map_alloc_id(map);
1599 if (err)
1600 goto free_map_sec;
1601
1602 bpf_map_save_memcg(map);
1603 bpf_token_put(token);
1604
1605 err = bpf_map_new_fd(map, f_flags);
1606 if (err < 0) {
1607 /* failed to allocate fd.
1608 * bpf_map_put_with_uref() is needed because the above
1609 * bpf_map_alloc_id() has published the map
1610 * to the userspace and the userspace may
1611 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1612 */
1613 bpf_map_put_with_uref(map);
1614 return err;
1615 }
1616
1617 return err;
1618
1619 free_map_sec:
1620 security_bpf_map_free(map);
1621 free_map:
1622 bpf_map_free(map);
1623 put_token:
1624 bpf_token_put(token);
1625 return err;
1626 }
1627
bpf_map_inc(struct bpf_map * map)1628 void bpf_map_inc(struct bpf_map *map)
1629 {
1630 atomic64_inc(&map->refcnt);
1631 }
1632 EXPORT_SYMBOL_GPL(bpf_map_inc);
1633
bpf_map_inc_with_uref(struct bpf_map * map)1634 void bpf_map_inc_with_uref(struct bpf_map *map)
1635 {
1636 atomic64_inc(&map->refcnt);
1637 atomic64_inc(&map->usercnt);
1638 }
1639 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1640
bpf_map_get(u32 ufd)1641 struct bpf_map *bpf_map_get(u32 ufd)
1642 {
1643 CLASS(fd, f)(ufd);
1644 struct bpf_map *map = __bpf_map_get(f);
1645
1646 if (!IS_ERR(map))
1647 bpf_map_inc(map);
1648
1649 return map;
1650 }
1651 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL");
1652
bpf_map_get_with_uref(u32 ufd)1653 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1654 {
1655 CLASS(fd, f)(ufd);
1656 struct bpf_map *map = __bpf_map_get(f);
1657
1658 if (!IS_ERR(map))
1659 bpf_map_inc_with_uref(map);
1660
1661 return map;
1662 }
1663
1664 /* map_idr_lock should have been held or the map should have been
1665 * protected by rcu read lock.
1666 */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1667 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1668 {
1669 int refold;
1670
1671 refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1672 if (!refold)
1673 return ERR_PTR(-ENOENT);
1674 if (uref)
1675 atomic64_inc(&map->usercnt);
1676
1677 return map;
1678 }
1679
bpf_map_inc_not_zero(struct bpf_map * map)1680 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1681 {
1682 lockdep_assert(rcu_read_lock_held());
1683 return __bpf_map_inc_not_zero(map, false);
1684 }
1685 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1686
bpf_stackmap_extract(struct bpf_map * map,void * key,void * value,bool delete)1687 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value,
1688 bool delete)
1689 {
1690 return -ENOTSUPP;
1691 }
1692
__bpf_copy_key(void __user * ukey,u64 key_size)1693 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1694 {
1695 if (key_size)
1696 return vmemdup_user(ukey, key_size);
1697
1698 if (ukey)
1699 return ERR_PTR(-EINVAL);
1700
1701 return NULL;
1702 }
1703
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1704 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1705 {
1706 if (key_size)
1707 return kvmemdup_bpfptr(ukey, key_size);
1708
1709 if (!bpfptr_is_null(ukey))
1710 return ERR_PTR(-EINVAL);
1711
1712 return NULL;
1713 }
1714
1715 /* last field in 'union bpf_attr' used by this command */
1716 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1717
map_lookup_elem(union bpf_attr * attr)1718 static int map_lookup_elem(union bpf_attr *attr)
1719 {
1720 void __user *ukey = u64_to_user_ptr(attr->key);
1721 void __user *uvalue = u64_to_user_ptr(attr->value);
1722 struct bpf_map *map;
1723 void *key, *value;
1724 u32 value_size;
1725 int err;
1726
1727 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1728 return -EINVAL;
1729
1730 CLASS(fd, f)(attr->map_fd);
1731 map = __bpf_map_get(f);
1732 if (IS_ERR(map))
1733 return PTR_ERR(map);
1734 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1735 return -EPERM;
1736
1737 err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK);
1738 if (err)
1739 return err;
1740
1741 key = __bpf_copy_key(ukey, map->key_size);
1742 if (IS_ERR(key))
1743 return PTR_ERR(key);
1744
1745 value_size = bpf_map_value_size(map);
1746
1747 err = -ENOMEM;
1748 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1749 if (!value)
1750 goto free_key;
1751
1752 if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1753 if (copy_from_user(value, uvalue, value_size))
1754 err = -EFAULT;
1755 else
1756 err = bpf_map_copy_value(map, key, value, attr->flags);
1757 goto free_value;
1758 }
1759
1760 err = bpf_map_copy_value(map, key, value, attr->flags);
1761 if (err)
1762 goto free_value;
1763
1764 err = -EFAULT;
1765 if (copy_to_user(uvalue, value, value_size) != 0)
1766 goto free_value;
1767
1768 err = 0;
1769
1770 free_value:
1771 kvfree(value);
1772 free_key:
1773 kvfree(key);
1774 return err;
1775 }
1776
1777
1778 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1779
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1780 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1781 {
1782 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1783 bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1784 struct bpf_map *map;
1785 void *key, *value;
1786 u32 value_size;
1787 int err;
1788
1789 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1790 return -EINVAL;
1791
1792 CLASS(fd, f)(attr->map_fd);
1793 map = __bpf_map_get(f);
1794 if (IS_ERR(map))
1795 return PTR_ERR(map);
1796 bpf_map_write_active_inc(map);
1797 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1798 err = -EPERM;
1799 goto err_put;
1800 }
1801
1802 err = bpf_map_check_op_flags(map, attr->flags, ~0);
1803 if (err)
1804 goto err_put;
1805
1806 key = ___bpf_copy_key(ukey, map->key_size);
1807 if (IS_ERR(key)) {
1808 err = PTR_ERR(key);
1809 goto err_put;
1810 }
1811
1812 value_size = bpf_map_value_size(map);
1813 value = kvmemdup_bpfptr(uvalue, value_size);
1814 if (IS_ERR(value)) {
1815 err = PTR_ERR(value);
1816 goto free_key;
1817 }
1818
1819 err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1820 if (!err)
1821 maybe_wait_bpf_programs(map);
1822
1823 kvfree(value);
1824 free_key:
1825 kvfree(key);
1826 err_put:
1827 bpf_map_write_active_dec(map);
1828 return err;
1829 }
1830
1831 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1832
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1833 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1834 {
1835 bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1836 struct bpf_map *map;
1837 void *key;
1838 int err;
1839
1840 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1841 return -EINVAL;
1842
1843 CLASS(fd, f)(attr->map_fd);
1844 map = __bpf_map_get(f);
1845 if (IS_ERR(map))
1846 return PTR_ERR(map);
1847 bpf_map_write_active_inc(map);
1848 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1849 err = -EPERM;
1850 goto err_put;
1851 }
1852
1853 key = ___bpf_copy_key(ukey, map->key_size);
1854 if (IS_ERR(key)) {
1855 err = PTR_ERR(key);
1856 goto err_put;
1857 }
1858
1859 if (bpf_map_is_offloaded(map)) {
1860 err = bpf_map_offload_delete_elem(map, key);
1861 goto out;
1862 } else if (IS_FD_PROG_ARRAY(map) ||
1863 map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1864 /* These maps require sleepable context */
1865 err = map->ops->map_delete_elem(map, key);
1866 goto out;
1867 }
1868
1869 bpf_disable_instrumentation();
1870 rcu_read_lock();
1871 err = map->ops->map_delete_elem(map, key);
1872 rcu_read_unlock();
1873 bpf_enable_instrumentation();
1874 if (!err)
1875 maybe_wait_bpf_programs(map);
1876 out:
1877 kvfree(key);
1878 err_put:
1879 bpf_map_write_active_dec(map);
1880 return err;
1881 }
1882
1883 /* last field in 'union bpf_attr' used by this command */
1884 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1885
map_get_next_key(union bpf_attr * attr)1886 static int map_get_next_key(union bpf_attr *attr)
1887 {
1888 void __user *ukey = u64_to_user_ptr(attr->key);
1889 void __user *unext_key = u64_to_user_ptr(attr->next_key);
1890 struct bpf_map *map;
1891 void *key, *next_key;
1892 int err;
1893
1894 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1895 return -EINVAL;
1896
1897 CLASS(fd, f)(attr->map_fd);
1898 map = __bpf_map_get(f);
1899 if (IS_ERR(map))
1900 return PTR_ERR(map);
1901 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1902 return -EPERM;
1903
1904 if (ukey) {
1905 key = __bpf_copy_key(ukey, map->key_size);
1906 if (IS_ERR(key))
1907 return PTR_ERR(key);
1908 } else {
1909 key = NULL;
1910 }
1911
1912 err = -ENOMEM;
1913 next_key = kvmalloc(map->key_size, GFP_USER);
1914 if (!next_key)
1915 goto free_key;
1916
1917 if (bpf_map_is_offloaded(map)) {
1918 err = bpf_map_offload_get_next_key(map, key, next_key);
1919 goto out;
1920 }
1921
1922 rcu_read_lock();
1923 err = map->ops->map_get_next_key(map, key, next_key);
1924 rcu_read_unlock();
1925 out:
1926 if (err)
1927 goto free_next_key;
1928
1929 err = -EFAULT;
1930 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1931 goto free_next_key;
1932
1933 err = 0;
1934
1935 free_next_key:
1936 kvfree(next_key);
1937 free_key:
1938 kvfree(key);
1939 return err;
1940 }
1941
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1942 int generic_map_delete_batch(struct bpf_map *map,
1943 const union bpf_attr *attr,
1944 union bpf_attr __user *uattr)
1945 {
1946 void __user *keys = u64_to_user_ptr(attr->batch.keys);
1947 u32 cp, max_count;
1948 int err = 0;
1949 void *key;
1950
1951 if (attr->batch.elem_flags & ~BPF_F_LOCK)
1952 return -EINVAL;
1953
1954 if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1955 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1956 return -EINVAL;
1957 }
1958
1959 max_count = attr->batch.count;
1960 if (!max_count)
1961 return 0;
1962
1963 if (put_user(0, &uattr->batch.count))
1964 return -EFAULT;
1965
1966 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1967 if (!key)
1968 return -ENOMEM;
1969
1970 for (cp = 0; cp < max_count; cp++) {
1971 err = -EFAULT;
1972 if (copy_from_user(key, keys + cp * map->key_size,
1973 map->key_size))
1974 break;
1975
1976 if (bpf_map_is_offloaded(map)) {
1977 err = bpf_map_offload_delete_elem(map, key);
1978 break;
1979 }
1980
1981 bpf_disable_instrumentation();
1982 rcu_read_lock();
1983 err = map->ops->map_delete_elem(map, key);
1984 rcu_read_unlock();
1985 bpf_enable_instrumentation();
1986 if (err)
1987 break;
1988 cond_resched();
1989 }
1990 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1991 err = -EFAULT;
1992
1993 kvfree(key);
1994
1995 return err;
1996 }
1997
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1998 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1999 const union bpf_attr *attr,
2000 union bpf_attr __user *uattr)
2001 {
2002 void __user *values = u64_to_user_ptr(attr->batch.values);
2003 void __user *keys = u64_to_user_ptr(attr->batch.keys);
2004 u32 value_size, cp, max_count;
2005 void *key, *value;
2006 int err = 0;
2007
2008 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK);
2009 if (err)
2010 return err;
2011
2012 value_size = bpf_map_value_size(map);
2013
2014 max_count = attr->batch.count;
2015 if (!max_count)
2016 return 0;
2017
2018 if (put_user(0, &uattr->batch.count))
2019 return -EFAULT;
2020
2021 key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2022 if (!key)
2023 return -ENOMEM;
2024
2025 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2026 if (!value) {
2027 kvfree(key);
2028 return -ENOMEM;
2029 }
2030
2031 for (cp = 0; cp < max_count; cp++) {
2032 err = -EFAULT;
2033 if (copy_from_user(key, keys + cp * map->key_size,
2034 map->key_size) ||
2035 copy_from_user(value, values + cp * value_size, value_size))
2036 break;
2037
2038 err = bpf_map_update_value(map, map_file, key, value,
2039 attr->batch.elem_flags);
2040
2041 if (err)
2042 break;
2043 cond_resched();
2044 }
2045
2046 if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
2047 err = -EFAULT;
2048
2049 kvfree(value);
2050 kvfree(key);
2051
2052 return err;
2053 }
2054
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)2055 int generic_map_lookup_batch(struct bpf_map *map,
2056 const union bpf_attr *attr,
2057 union bpf_attr __user *uattr)
2058 {
2059 void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
2060 void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
2061 void __user *values = u64_to_user_ptr(attr->batch.values);
2062 void __user *keys = u64_to_user_ptr(attr->batch.keys);
2063 void *buf, *buf_prevkey, *prev_key, *key, *value;
2064 u32 value_size, cp, max_count;
2065 int err;
2066
2067 err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK);
2068 if (err)
2069 return err;
2070
2071 value_size = bpf_map_value_size(map);
2072
2073 max_count = attr->batch.count;
2074 if (!max_count)
2075 return 0;
2076
2077 if (put_user(0, &uattr->batch.count))
2078 return -EFAULT;
2079
2080 buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2081 if (!buf_prevkey)
2082 return -ENOMEM;
2083
2084 buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2085 if (!buf) {
2086 kvfree(buf_prevkey);
2087 return -ENOMEM;
2088 }
2089
2090 err = -EFAULT;
2091 prev_key = NULL;
2092 if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2093 goto free_buf;
2094 key = buf;
2095 value = key + map->key_size;
2096 if (ubatch)
2097 prev_key = buf_prevkey;
2098
2099 for (cp = 0; cp < max_count;) {
2100 rcu_read_lock();
2101 err = map->ops->map_get_next_key(map, prev_key, key);
2102 rcu_read_unlock();
2103 if (err)
2104 break;
2105 err = bpf_map_copy_value(map, key, value,
2106 attr->batch.elem_flags);
2107
2108 if (err == -ENOENT)
2109 goto next_key;
2110
2111 if (err)
2112 goto free_buf;
2113
2114 if (copy_to_user(keys + cp * map->key_size, key,
2115 map->key_size)) {
2116 err = -EFAULT;
2117 goto free_buf;
2118 }
2119 if (copy_to_user(values + cp * value_size, value, value_size)) {
2120 err = -EFAULT;
2121 goto free_buf;
2122 }
2123
2124 cp++;
2125 next_key:
2126 if (!prev_key)
2127 prev_key = buf_prevkey;
2128
2129 swap(prev_key, key);
2130 cond_resched();
2131 }
2132
2133 if (err == -EFAULT)
2134 goto free_buf;
2135
2136 if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2137 (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2138 err = -EFAULT;
2139
2140 free_buf:
2141 kvfree(buf_prevkey);
2142 kvfree(buf);
2143 return err;
2144 }
2145
2146 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2147
map_lookup_and_delete_elem(union bpf_attr * attr)2148 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2149 {
2150 void __user *ukey = u64_to_user_ptr(attr->key);
2151 void __user *uvalue = u64_to_user_ptr(attr->value);
2152 struct bpf_map *map;
2153 void *key, *value;
2154 u32 value_size;
2155 int err;
2156
2157 if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2158 return -EINVAL;
2159
2160 if (attr->flags & ~BPF_F_LOCK)
2161 return -EINVAL;
2162
2163 CLASS(fd, f)(attr->map_fd);
2164 map = __bpf_map_get(f);
2165 if (IS_ERR(map))
2166 return PTR_ERR(map);
2167 bpf_map_write_active_inc(map);
2168 if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2169 !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2170 err = -EPERM;
2171 goto err_put;
2172 }
2173
2174 if (attr->flags &&
2175 (map->map_type == BPF_MAP_TYPE_QUEUE ||
2176 map->map_type == BPF_MAP_TYPE_STACK)) {
2177 err = -EINVAL;
2178 goto err_put;
2179 }
2180
2181 if ((attr->flags & BPF_F_LOCK) &&
2182 !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2183 err = -EINVAL;
2184 goto err_put;
2185 }
2186
2187 key = __bpf_copy_key(ukey, map->key_size);
2188 if (IS_ERR(key)) {
2189 err = PTR_ERR(key);
2190 goto err_put;
2191 }
2192
2193 value_size = bpf_map_value_size(map);
2194
2195 err = -ENOMEM;
2196 value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2197 if (!value)
2198 goto free_key;
2199
2200 err = -ENOTSUPP;
2201 if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2202 map->map_type == BPF_MAP_TYPE_STACK) {
2203 err = map->ops->map_pop_elem(map, value);
2204 } else if (map->map_type == BPF_MAP_TYPE_HASH ||
2205 map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2206 map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2207 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
2208 map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
2209 if (!bpf_map_is_offloaded(map)) {
2210 bpf_disable_instrumentation();
2211 rcu_read_lock();
2212 err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2213 rcu_read_unlock();
2214 bpf_enable_instrumentation();
2215 }
2216 }
2217
2218 if (err)
2219 goto free_value;
2220
2221 if (copy_to_user(uvalue, value, value_size) != 0) {
2222 err = -EFAULT;
2223 goto free_value;
2224 }
2225
2226 err = 0;
2227
2228 free_value:
2229 kvfree(value);
2230 free_key:
2231 kvfree(key);
2232 err_put:
2233 bpf_map_write_active_dec(map);
2234 return err;
2235 }
2236
2237 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2238
map_freeze(const union bpf_attr * attr)2239 static int map_freeze(const union bpf_attr *attr)
2240 {
2241 int err = 0;
2242 struct bpf_map *map;
2243
2244 if (CHECK_ATTR(BPF_MAP_FREEZE))
2245 return -EINVAL;
2246
2247 CLASS(fd, f)(attr->map_fd);
2248 map = __bpf_map_get(f);
2249 if (IS_ERR(map))
2250 return PTR_ERR(map);
2251
2252 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2253 return -ENOTSUPP;
2254
2255 if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2256 return -EPERM;
2257
2258 mutex_lock(&map->freeze_mutex);
2259 if (bpf_map_write_active(map)) {
2260 err = -EBUSY;
2261 goto err_put;
2262 }
2263 if (READ_ONCE(map->frozen)) {
2264 err = -EBUSY;
2265 goto err_put;
2266 }
2267
2268 WRITE_ONCE(map->frozen, true);
2269 err_put:
2270 mutex_unlock(&map->freeze_mutex);
2271 return err;
2272 }
2273
2274 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2275 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2276 [_id] = & _name ## _prog_ops,
2277 #define BPF_MAP_TYPE(_id, _ops)
2278 #define BPF_LINK_TYPE(_id, _name)
2279 #include <linux/bpf_types.h>
2280 #undef BPF_PROG_TYPE
2281 #undef BPF_MAP_TYPE
2282 #undef BPF_LINK_TYPE
2283 };
2284
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2285 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2286 {
2287 const struct bpf_prog_ops *ops;
2288
2289 if (type >= ARRAY_SIZE(bpf_prog_types))
2290 return -EINVAL;
2291 type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2292 ops = bpf_prog_types[type];
2293 if (!ops)
2294 return -EINVAL;
2295
2296 if (!bpf_prog_is_offloaded(prog->aux))
2297 prog->aux->ops = ops;
2298 else
2299 prog->aux->ops = &bpf_offload_prog_ops;
2300 prog->type = type;
2301 return 0;
2302 }
2303
2304 enum bpf_audit {
2305 BPF_AUDIT_LOAD,
2306 BPF_AUDIT_UNLOAD,
2307 BPF_AUDIT_MAX,
2308 };
2309
2310 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2311 [BPF_AUDIT_LOAD] = "LOAD",
2312 [BPF_AUDIT_UNLOAD] = "UNLOAD",
2313 };
2314
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2315 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2316 {
2317 struct audit_context *ctx = NULL;
2318 struct audit_buffer *ab;
2319
2320 if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2321 return;
2322 if (audit_enabled == AUDIT_OFF)
2323 return;
2324 if (!in_hardirq() && !irqs_disabled())
2325 ctx = audit_context();
2326 ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2327 if (unlikely(!ab))
2328 return;
2329 audit_log_format(ab, "prog-id=%u op=%s",
2330 prog->aux->id, bpf_audit_str[op]);
2331 audit_log_end(ab);
2332 }
2333
bpf_prog_alloc_id(struct bpf_prog * prog)2334 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2335 {
2336 int id;
2337
2338 idr_preload(GFP_KERNEL);
2339 spin_lock_bh(&prog_idr_lock);
2340 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2341 if (id > 0)
2342 prog->aux->id = id;
2343 spin_unlock_bh(&prog_idr_lock);
2344 idr_preload_end();
2345
2346 /* id is in [1, INT_MAX) */
2347 if (WARN_ON_ONCE(!id))
2348 return -ENOSPC;
2349
2350 return id > 0 ? 0 : id;
2351 }
2352
bpf_prog_free_id(struct bpf_prog * prog)2353 void bpf_prog_free_id(struct bpf_prog *prog)
2354 {
2355 unsigned long flags;
2356
2357 /* cBPF to eBPF migrations are currently not in the idr store.
2358 * Offloaded programs are removed from the store when their device
2359 * disappears - even if someone grabs an fd to them they are unusable,
2360 * simply waiting for refcnt to drop to be freed.
2361 */
2362 if (!prog->aux->id)
2363 return;
2364
2365 spin_lock_irqsave(&prog_idr_lock, flags);
2366 idr_remove(&prog_idr, prog->aux->id);
2367 prog->aux->id = 0;
2368 spin_unlock_irqrestore(&prog_idr_lock, flags);
2369 }
2370
__bpf_prog_put_rcu(struct rcu_head * rcu)2371 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2372 {
2373 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2374
2375 kvfree(aux->func_info);
2376 kfree(aux->func_info_aux);
2377 free_uid(aux->user);
2378 security_bpf_prog_free(aux->prog);
2379 bpf_prog_free(aux->prog);
2380 }
2381
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2382 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2383 {
2384 bpf_prog_kallsyms_del_all(prog);
2385 btf_put(prog->aux->btf);
2386 module_put(prog->aux->mod);
2387 kvfree(prog->aux->jited_linfo);
2388 kvfree(prog->aux->linfo);
2389 kfree(prog->aux->kfunc_tab);
2390 kfree(prog->aux->ctx_arg_info);
2391 if (prog->aux->attach_btf)
2392 btf_put(prog->aux->attach_btf);
2393
2394 if (deferred) {
2395 if (prog->sleepable)
2396 call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2397 else
2398 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2399 } else {
2400 __bpf_prog_put_rcu(&prog->aux->rcu);
2401 }
2402 }
2403
bpf_prog_put_deferred(struct work_struct * work)2404 static void bpf_prog_put_deferred(struct work_struct *work)
2405 {
2406 struct bpf_prog_aux *aux;
2407 struct bpf_prog *prog;
2408
2409 aux = container_of(work, struct bpf_prog_aux, work);
2410 prog = aux->prog;
2411 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2412 bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2413 bpf_prog_free_id(prog);
2414 __bpf_prog_put_noref(prog, true);
2415 }
2416
__bpf_prog_put(struct bpf_prog * prog)2417 static void __bpf_prog_put(struct bpf_prog *prog)
2418 {
2419 struct bpf_prog_aux *aux = prog->aux;
2420
2421 if (atomic64_dec_and_test(&aux->refcnt)) {
2422 if (in_hardirq() || irqs_disabled()) {
2423 INIT_WORK(&aux->work, bpf_prog_put_deferred);
2424 schedule_work(&aux->work);
2425 } else {
2426 bpf_prog_put_deferred(&aux->work);
2427 }
2428 }
2429 }
2430
bpf_prog_put(struct bpf_prog * prog)2431 void bpf_prog_put(struct bpf_prog *prog)
2432 {
2433 __bpf_prog_put(prog);
2434 }
2435 EXPORT_SYMBOL_GPL(bpf_prog_put);
2436
bpf_prog_release(struct inode * inode,struct file * filp)2437 static int bpf_prog_release(struct inode *inode, struct file *filp)
2438 {
2439 struct bpf_prog *prog = filp->private_data;
2440
2441 bpf_prog_put(prog);
2442 return 0;
2443 }
2444
2445 struct bpf_prog_kstats {
2446 u64 nsecs;
2447 u64 cnt;
2448 u64 misses;
2449 };
2450
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2451 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2452 {
2453 struct bpf_prog_stats *stats;
2454 unsigned int flags;
2455
2456 if (unlikely(!prog->stats))
2457 return;
2458
2459 stats = this_cpu_ptr(prog->stats);
2460 flags = u64_stats_update_begin_irqsave(&stats->syncp);
2461 u64_stats_inc(&stats->misses);
2462 u64_stats_update_end_irqrestore(&stats->syncp, flags);
2463 }
2464
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2465 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2466 struct bpf_prog_kstats *stats)
2467 {
2468 u64 nsecs = 0, cnt = 0, misses = 0;
2469 int cpu;
2470
2471 for_each_possible_cpu(cpu) {
2472 const struct bpf_prog_stats *st;
2473 unsigned int start;
2474 u64 tnsecs, tcnt, tmisses;
2475
2476 st = per_cpu_ptr(prog->stats, cpu);
2477 do {
2478 start = u64_stats_fetch_begin(&st->syncp);
2479 tnsecs = u64_stats_read(&st->nsecs);
2480 tcnt = u64_stats_read(&st->cnt);
2481 tmisses = u64_stats_read(&st->misses);
2482 } while (u64_stats_fetch_retry(&st->syncp, start));
2483 nsecs += tnsecs;
2484 cnt += tcnt;
2485 misses += tmisses;
2486 }
2487 stats->nsecs = nsecs;
2488 stats->cnt = cnt;
2489 stats->misses = misses;
2490 }
2491
2492 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2493 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2494 {
2495 const struct bpf_prog *prog = filp->private_data;
2496 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2497 struct bpf_prog_kstats stats;
2498
2499 bpf_prog_get_stats(prog, &stats);
2500 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2501 seq_printf(m,
2502 "prog_type:\t%u\n"
2503 "prog_jited:\t%u\n"
2504 "prog_tag:\t%s\n"
2505 "memlock:\t%llu\n"
2506 "prog_id:\t%u\n"
2507 "run_time_ns:\t%llu\n"
2508 "run_cnt:\t%llu\n"
2509 "recursion_misses:\t%llu\n"
2510 "verified_insns:\t%u\n",
2511 prog->type,
2512 prog->jited,
2513 prog_tag,
2514 prog->pages * 1ULL << PAGE_SHIFT,
2515 prog->aux->id,
2516 stats.nsecs,
2517 stats.cnt,
2518 stats.misses,
2519 prog->aux->verified_insns);
2520 }
2521 #endif
2522
2523 const struct file_operations bpf_prog_fops = {
2524 #ifdef CONFIG_PROC_FS
2525 .show_fdinfo = bpf_prog_show_fdinfo,
2526 #endif
2527 .release = bpf_prog_release,
2528 .read = bpf_dummy_read,
2529 .write = bpf_dummy_write,
2530 };
2531
bpf_prog_new_fd(struct bpf_prog * prog)2532 int bpf_prog_new_fd(struct bpf_prog *prog)
2533 {
2534 int ret;
2535
2536 ret = security_bpf_prog(prog);
2537 if (ret < 0)
2538 return ret;
2539
2540 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2541 O_RDWR | O_CLOEXEC);
2542 }
2543
bpf_prog_add(struct bpf_prog * prog,int i)2544 void bpf_prog_add(struct bpf_prog *prog, int i)
2545 {
2546 atomic64_add(i, &prog->aux->refcnt);
2547 }
2548 EXPORT_SYMBOL_GPL(bpf_prog_add);
2549
bpf_prog_sub(struct bpf_prog * prog,int i)2550 void bpf_prog_sub(struct bpf_prog *prog, int i)
2551 {
2552 /* Only to be used for undoing previous bpf_prog_add() in some
2553 * error path. We still know that another entity in our call
2554 * path holds a reference to the program, thus atomic_sub() can
2555 * be safely used in such cases!
2556 */
2557 WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2558 }
2559 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2560
bpf_prog_inc(struct bpf_prog * prog)2561 void bpf_prog_inc(struct bpf_prog *prog)
2562 {
2563 atomic64_inc(&prog->aux->refcnt);
2564 }
2565 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2566
2567 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2568 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2569 {
2570 int refold;
2571
2572 refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2573
2574 if (!refold)
2575 return ERR_PTR(-ENOENT);
2576
2577 return prog;
2578 }
2579 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2580
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2581 bool bpf_prog_get_ok(struct bpf_prog *prog,
2582 enum bpf_prog_type *attach_type, bool attach_drv)
2583 {
2584 /* not an attachment, just a refcount inc, always allow */
2585 if (!attach_type)
2586 return true;
2587
2588 if (prog->type != *attach_type)
2589 return false;
2590 if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2591 return false;
2592
2593 return true;
2594 }
2595
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2596 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2597 bool attach_drv)
2598 {
2599 CLASS(fd, f)(ufd);
2600 struct bpf_prog *prog;
2601
2602 if (fd_empty(f))
2603 return ERR_PTR(-EBADF);
2604 if (fd_file(f)->f_op != &bpf_prog_fops)
2605 return ERR_PTR(-EINVAL);
2606
2607 prog = fd_file(f)->private_data;
2608 if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2609 return ERR_PTR(-EINVAL);
2610
2611 bpf_prog_inc(prog);
2612 return prog;
2613 }
2614
bpf_prog_get(u32 ufd)2615 struct bpf_prog *bpf_prog_get(u32 ufd)
2616 {
2617 return __bpf_prog_get(ufd, NULL, false);
2618 }
2619
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2620 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2621 bool attach_drv)
2622 {
2623 return __bpf_prog_get(ufd, &type, attach_drv);
2624 }
2625 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2626
2627 /* Initially all BPF programs could be loaded w/o specifying
2628 * expected_attach_type. Later for some of them specifying expected_attach_type
2629 * at load time became required so that program could be validated properly.
2630 * Programs of types that are allowed to be loaded both w/ and w/o (for
2631 * backward compatibility) expected_attach_type, should have the default attach
2632 * type assigned to expected_attach_type for the latter case, so that it can be
2633 * validated later at attach time.
2634 *
2635 * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2636 * prog type requires it but has some attach types that have to be backward
2637 * compatible.
2638 */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2639 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2640 {
2641 switch (attr->prog_type) {
2642 case BPF_PROG_TYPE_CGROUP_SOCK:
2643 /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2644 * exist so checking for non-zero is the way to go here.
2645 */
2646 if (!attr->expected_attach_type)
2647 attr->expected_attach_type =
2648 BPF_CGROUP_INET_SOCK_CREATE;
2649 break;
2650 case BPF_PROG_TYPE_SK_REUSEPORT:
2651 if (!attr->expected_attach_type)
2652 attr->expected_attach_type =
2653 BPF_SK_REUSEPORT_SELECT;
2654 break;
2655 }
2656 }
2657
2658 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)2659 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2660 enum bpf_attach_type expected_attach_type,
2661 struct btf *attach_btf, u32 btf_id,
2662 struct bpf_prog *dst_prog)
2663 {
2664 if (btf_id) {
2665 if (btf_id > BTF_MAX_TYPE)
2666 return -EINVAL;
2667
2668 if (!attach_btf && !dst_prog)
2669 return -EINVAL;
2670
2671 switch (prog_type) {
2672 case BPF_PROG_TYPE_TRACING:
2673 case BPF_PROG_TYPE_LSM:
2674 case BPF_PROG_TYPE_STRUCT_OPS:
2675 case BPF_PROG_TYPE_EXT:
2676 break;
2677 default:
2678 return -EINVAL;
2679 }
2680 }
2681
2682 if (attach_btf && (!btf_id || dst_prog))
2683 return -EINVAL;
2684
2685 if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2686 prog_type != BPF_PROG_TYPE_EXT)
2687 return -EINVAL;
2688
2689 switch (prog_type) {
2690 case BPF_PROG_TYPE_CGROUP_SOCK:
2691 switch (expected_attach_type) {
2692 case BPF_CGROUP_INET_SOCK_CREATE:
2693 case BPF_CGROUP_INET_SOCK_RELEASE:
2694 case BPF_CGROUP_INET4_POST_BIND:
2695 case BPF_CGROUP_INET6_POST_BIND:
2696 return 0;
2697 default:
2698 return -EINVAL;
2699 }
2700 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2701 switch (expected_attach_type) {
2702 case BPF_CGROUP_INET4_BIND:
2703 case BPF_CGROUP_INET6_BIND:
2704 case BPF_CGROUP_INET4_CONNECT:
2705 case BPF_CGROUP_INET6_CONNECT:
2706 case BPF_CGROUP_UNIX_CONNECT:
2707 case BPF_CGROUP_INET4_GETPEERNAME:
2708 case BPF_CGROUP_INET6_GETPEERNAME:
2709 case BPF_CGROUP_UNIX_GETPEERNAME:
2710 case BPF_CGROUP_INET4_GETSOCKNAME:
2711 case BPF_CGROUP_INET6_GETSOCKNAME:
2712 case BPF_CGROUP_UNIX_GETSOCKNAME:
2713 case BPF_CGROUP_UDP4_SENDMSG:
2714 case BPF_CGROUP_UDP6_SENDMSG:
2715 case BPF_CGROUP_UNIX_SENDMSG:
2716 case BPF_CGROUP_UDP4_RECVMSG:
2717 case BPF_CGROUP_UDP6_RECVMSG:
2718 case BPF_CGROUP_UNIX_RECVMSG:
2719 return 0;
2720 default:
2721 return -EINVAL;
2722 }
2723 case BPF_PROG_TYPE_CGROUP_SKB:
2724 switch (expected_attach_type) {
2725 case BPF_CGROUP_INET_INGRESS:
2726 case BPF_CGROUP_INET_EGRESS:
2727 return 0;
2728 default:
2729 return -EINVAL;
2730 }
2731 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2732 switch (expected_attach_type) {
2733 case BPF_CGROUP_SETSOCKOPT:
2734 case BPF_CGROUP_GETSOCKOPT:
2735 return 0;
2736 default:
2737 return -EINVAL;
2738 }
2739 case BPF_PROG_TYPE_SK_LOOKUP:
2740 if (expected_attach_type == BPF_SK_LOOKUP)
2741 return 0;
2742 return -EINVAL;
2743 case BPF_PROG_TYPE_SK_REUSEPORT:
2744 switch (expected_attach_type) {
2745 case BPF_SK_REUSEPORT_SELECT:
2746 case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2747 return 0;
2748 default:
2749 return -EINVAL;
2750 }
2751 case BPF_PROG_TYPE_NETFILTER:
2752 if (expected_attach_type == BPF_NETFILTER)
2753 return 0;
2754 return -EINVAL;
2755 case BPF_PROG_TYPE_SYSCALL:
2756 case BPF_PROG_TYPE_EXT:
2757 if (expected_attach_type)
2758 return -EINVAL;
2759 fallthrough;
2760 default:
2761 return 0;
2762 }
2763 }
2764
is_net_admin_prog_type(enum bpf_prog_type prog_type)2765 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2766 {
2767 switch (prog_type) {
2768 case BPF_PROG_TYPE_SCHED_CLS:
2769 case BPF_PROG_TYPE_SCHED_ACT:
2770 case BPF_PROG_TYPE_XDP:
2771 case BPF_PROG_TYPE_LWT_IN:
2772 case BPF_PROG_TYPE_LWT_OUT:
2773 case BPF_PROG_TYPE_LWT_XMIT:
2774 case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2775 case BPF_PROG_TYPE_SK_SKB:
2776 case BPF_PROG_TYPE_SK_MSG:
2777 case BPF_PROG_TYPE_FLOW_DISSECTOR:
2778 case BPF_PROG_TYPE_CGROUP_DEVICE:
2779 case BPF_PROG_TYPE_CGROUP_SOCK:
2780 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2781 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2782 case BPF_PROG_TYPE_CGROUP_SYSCTL:
2783 case BPF_PROG_TYPE_SOCK_OPS:
2784 case BPF_PROG_TYPE_EXT: /* extends any prog */
2785 case BPF_PROG_TYPE_NETFILTER:
2786 return true;
2787 case BPF_PROG_TYPE_CGROUP_SKB:
2788 /* always unpriv */
2789 case BPF_PROG_TYPE_SK_REUSEPORT:
2790 /* equivalent to SOCKET_FILTER. need CAP_BPF only */
2791 default:
2792 return false;
2793 }
2794 }
2795
is_perfmon_prog_type(enum bpf_prog_type prog_type)2796 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2797 {
2798 switch (prog_type) {
2799 case BPF_PROG_TYPE_KPROBE:
2800 case BPF_PROG_TYPE_TRACEPOINT:
2801 case BPF_PROG_TYPE_PERF_EVENT:
2802 case BPF_PROG_TYPE_RAW_TRACEPOINT:
2803 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2804 case BPF_PROG_TYPE_TRACING:
2805 case BPF_PROG_TYPE_LSM:
2806 case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2807 case BPF_PROG_TYPE_EXT: /* extends any prog */
2808 return true;
2809 default:
2810 return false;
2811 }
2812 }
2813
bpf_prog_verify_signature(struct bpf_prog * prog,union bpf_attr * attr,bool is_kernel)2814 static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr,
2815 bool is_kernel)
2816 {
2817 bpfptr_t usig = make_bpfptr(attr->signature, is_kernel);
2818 struct bpf_dynptr_kern sig_ptr, insns_ptr;
2819 struct bpf_key *key = NULL;
2820 void *sig;
2821 int err = 0;
2822
2823 if (system_keyring_id_check(attr->keyring_id) == 0)
2824 key = bpf_lookup_system_key(attr->keyring_id);
2825 else
2826 key = bpf_lookup_user_key(attr->keyring_id, 0);
2827
2828 if (!key)
2829 return -EINVAL;
2830
2831 sig = kvmemdup_bpfptr(usig, attr->signature_size);
2832 if (IS_ERR(sig)) {
2833 bpf_key_put(key);
2834 return -ENOMEM;
2835 }
2836
2837 bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0,
2838 attr->signature_size);
2839 bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0,
2840 prog->len * sizeof(struct bpf_insn));
2841
2842 err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr,
2843 (struct bpf_dynptr *)&sig_ptr, key);
2844
2845 bpf_key_put(key);
2846 kvfree(sig);
2847 return err;
2848 }
2849
bpf_prog_mark_insn_arrays_ready(struct bpf_prog * prog)2850 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog)
2851 {
2852 int err;
2853 int i;
2854
2855 for (i = 0; i < prog->aux->used_map_cnt; i++) {
2856 if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY)
2857 continue;
2858
2859 err = bpf_insn_array_ready(prog->aux->used_maps[i]);
2860 if (err)
2861 return err;
2862 }
2863
2864 return 0;
2865 }
2866
2867 /* last field in 'union bpf_attr' used by this command */
2868 #define BPF_PROG_LOAD_LAST_FIELD keyring_id
2869
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2870 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2871 {
2872 enum bpf_prog_type type = attr->prog_type;
2873 struct bpf_prog *prog, *dst_prog = NULL;
2874 struct btf *attach_btf = NULL;
2875 struct bpf_token *token = NULL;
2876 bool bpf_cap;
2877 int err;
2878 char license[128];
2879
2880 if (CHECK_ATTR(BPF_PROG_LOAD))
2881 return -EINVAL;
2882
2883 if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2884 BPF_F_ANY_ALIGNMENT |
2885 BPF_F_TEST_STATE_FREQ |
2886 BPF_F_SLEEPABLE |
2887 BPF_F_TEST_RND_HI32 |
2888 BPF_F_XDP_HAS_FRAGS |
2889 BPF_F_XDP_DEV_BOUND_ONLY |
2890 BPF_F_TEST_REG_INVARIANTS |
2891 BPF_F_TOKEN_FD))
2892 return -EINVAL;
2893
2894 bpf_prog_load_fixup_attach_type(attr);
2895
2896 if (attr->prog_flags & BPF_F_TOKEN_FD) {
2897 token = bpf_token_get_from_fd(attr->prog_token_fd);
2898 if (IS_ERR(token))
2899 return PTR_ERR(token);
2900 /* if current token doesn't grant prog loading permissions,
2901 * then we can't use this token, so ignore it and rely on
2902 * system-wide capabilities checks
2903 */
2904 if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2905 !bpf_token_allow_prog_type(token, attr->prog_type,
2906 attr->expected_attach_type)) {
2907 bpf_token_put(token);
2908 token = NULL;
2909 }
2910 }
2911
2912 bpf_cap = bpf_token_capable(token, CAP_BPF);
2913 err = -EPERM;
2914
2915 if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2916 (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2917 !bpf_cap)
2918 goto put_token;
2919
2920 /* Intent here is for unprivileged_bpf_disabled to block BPF program
2921 * creation for unprivileged users; other actions depend
2922 * on fd availability and access to bpffs, so are dependent on
2923 * object creation success. Even with unprivileged BPF disabled,
2924 * capability checks are still carried out for these
2925 * and other operations.
2926 */
2927 if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2928 goto put_token;
2929
2930 if (attr->insn_cnt == 0 ||
2931 attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2932 err = -E2BIG;
2933 goto put_token;
2934 }
2935 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2936 type != BPF_PROG_TYPE_CGROUP_SKB &&
2937 !bpf_cap)
2938 goto put_token;
2939
2940 if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2941 goto put_token;
2942 if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2943 goto put_token;
2944
2945 /* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2946 * or btf, we need to check which one it is
2947 */
2948 if (attr->attach_prog_fd) {
2949 dst_prog = bpf_prog_get(attr->attach_prog_fd);
2950 if (IS_ERR(dst_prog)) {
2951 dst_prog = NULL;
2952 attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2953 if (IS_ERR(attach_btf)) {
2954 err = -EINVAL;
2955 goto put_token;
2956 }
2957 if (!btf_is_kernel(attach_btf)) {
2958 /* attaching through specifying bpf_prog's BTF
2959 * objects directly might be supported eventually
2960 */
2961 btf_put(attach_btf);
2962 err = -ENOTSUPP;
2963 goto put_token;
2964 }
2965 }
2966 } else if (attr->attach_btf_id) {
2967 /* fall back to vmlinux BTF, if BTF type ID is specified */
2968 attach_btf = bpf_get_btf_vmlinux();
2969 if (IS_ERR(attach_btf)) {
2970 err = PTR_ERR(attach_btf);
2971 goto put_token;
2972 }
2973 if (!attach_btf) {
2974 err = -EINVAL;
2975 goto put_token;
2976 }
2977 btf_get(attach_btf);
2978 }
2979
2980 if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2981 attach_btf, attr->attach_btf_id,
2982 dst_prog)) {
2983 if (dst_prog)
2984 bpf_prog_put(dst_prog);
2985 if (attach_btf)
2986 btf_put(attach_btf);
2987 err = -EINVAL;
2988 goto put_token;
2989 }
2990
2991 /* plain bpf_prog allocation */
2992 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2993 if (!prog) {
2994 if (dst_prog)
2995 bpf_prog_put(dst_prog);
2996 if (attach_btf)
2997 btf_put(attach_btf);
2998 err = -EINVAL;
2999 goto put_token;
3000 }
3001
3002 prog->expected_attach_type = attr->expected_attach_type;
3003 prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
3004 prog->aux->attach_btf = attach_btf;
3005 prog->aux->attach_btf_id = attr->attach_btf_id;
3006 prog->aux->dst_prog = dst_prog;
3007 prog->aux->dev_bound = !!attr->prog_ifindex;
3008 prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
3009
3010 /* move token into prog->aux, reuse taken refcnt */
3011 prog->aux->token = token;
3012 token = NULL;
3013
3014 prog->aux->user = get_current_user();
3015 prog->len = attr->insn_cnt;
3016
3017 err = -EFAULT;
3018 if (copy_from_bpfptr(prog->insns,
3019 make_bpfptr(attr->insns, uattr.is_kernel),
3020 bpf_prog_insn_size(prog)) != 0)
3021 goto free_prog;
3022 /* copy eBPF program license from user space */
3023 if (strncpy_from_bpfptr(license,
3024 make_bpfptr(attr->license, uattr.is_kernel),
3025 sizeof(license) - 1) < 0)
3026 goto free_prog;
3027 license[sizeof(license) - 1] = 0;
3028
3029 /* eBPF programs must be GPL compatible to use GPL-ed functions */
3030 prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
3031
3032 if (attr->signature) {
3033 err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel);
3034 if (err)
3035 goto free_prog;
3036 }
3037
3038 prog->orig_prog = NULL;
3039 prog->jited = 0;
3040
3041 atomic64_set(&prog->aux->refcnt, 1);
3042
3043 if (bpf_prog_is_dev_bound(prog->aux)) {
3044 err = bpf_prog_dev_bound_init(prog, attr);
3045 if (err)
3046 goto free_prog;
3047 }
3048
3049 if (type == BPF_PROG_TYPE_EXT && dst_prog &&
3050 bpf_prog_is_dev_bound(dst_prog->aux)) {
3051 err = bpf_prog_dev_bound_inherit(prog, dst_prog);
3052 if (err)
3053 goto free_prog;
3054 }
3055
3056 /*
3057 * Bookkeeping for managing the program attachment chain.
3058 *
3059 * It might be tempting to set attach_tracing_prog flag at the attachment
3060 * time, but this will not prevent from loading bunch of tracing prog
3061 * first, then attach them one to another.
3062 *
3063 * The flag attach_tracing_prog is set for the whole program lifecycle, and
3064 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
3065 * programs cannot change attachment target.
3066 */
3067 if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
3068 dst_prog->type == BPF_PROG_TYPE_TRACING) {
3069 prog->aux->attach_tracing_prog = true;
3070 }
3071
3072 /* find program type: socket_filter vs tracing_filter */
3073 err = find_prog_type(type, prog);
3074 if (err < 0)
3075 goto free_prog;
3076
3077 prog->aux->load_time = ktime_get_boottime_ns();
3078 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
3079 sizeof(attr->prog_name));
3080 if (err < 0)
3081 goto free_prog;
3082
3083 err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel);
3084 if (err)
3085 goto free_prog_sec;
3086
3087 /* run eBPF verifier */
3088 err = bpf_check(&prog, attr, uattr, uattr_size);
3089 if (err < 0)
3090 goto free_used_maps;
3091
3092 prog = bpf_prog_select_runtime(prog, &err);
3093 if (err < 0)
3094 goto free_used_maps;
3095
3096 err = bpf_prog_mark_insn_arrays_ready(prog);
3097 if (err < 0)
3098 goto free_used_maps;
3099
3100 err = bpf_prog_alloc_id(prog);
3101 if (err)
3102 goto free_used_maps;
3103
3104 /* Upon success of bpf_prog_alloc_id(), the BPF prog is
3105 * effectively publicly exposed. However, retrieving via
3106 * bpf_prog_get_fd_by_id() will take another reference,
3107 * therefore it cannot be gone underneath us.
3108 *
3109 * Only for the time /after/ successful bpf_prog_new_fd()
3110 * and before returning to userspace, we might just hold
3111 * one reference and any parallel close on that fd could
3112 * rip everything out. Hence, below notifications must
3113 * happen before bpf_prog_new_fd().
3114 *
3115 * Also, any failure handling from this point onwards must
3116 * be using bpf_prog_put() given the program is exposed.
3117 */
3118 bpf_prog_kallsyms_add(prog);
3119 perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
3120 bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3121
3122 err = bpf_prog_new_fd(prog);
3123 if (err < 0)
3124 bpf_prog_put(prog);
3125 return err;
3126
3127 free_used_maps:
3128 /* In case we have subprogs, we need to wait for a grace
3129 * period before we can tear down JIT memory since symbols
3130 * are already exposed under kallsyms.
3131 */
3132 __bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3133 return err;
3134
3135 free_prog_sec:
3136 security_bpf_prog_free(prog);
3137 free_prog:
3138 free_uid(prog->aux->user);
3139 if (prog->aux->attach_btf)
3140 btf_put(prog->aux->attach_btf);
3141 bpf_prog_free(prog);
3142 put_token:
3143 bpf_token_put(token);
3144 return err;
3145 }
3146
3147 #define BPF_OBJ_LAST_FIELD path_fd
3148
bpf_obj_pin(const union bpf_attr * attr)3149 static int bpf_obj_pin(const union bpf_attr *attr)
3150 {
3151 int path_fd;
3152
3153 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3154 return -EINVAL;
3155
3156 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3157 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3158 return -EINVAL;
3159
3160 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3161 return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3162 u64_to_user_ptr(attr->pathname));
3163 }
3164
bpf_obj_get(const union bpf_attr * attr)3165 static int bpf_obj_get(const union bpf_attr *attr)
3166 {
3167 int path_fd;
3168
3169 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3170 attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3171 return -EINVAL;
3172
3173 /* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3174 if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3175 return -EINVAL;
3176
3177 path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3178 return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3179 attr->file_flags);
3180 }
3181
3182 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3183 * "sleepable" semantics, which normally would mean that BPF link's attach
3184 * hook can dereference link or link's underlying program for some time after
3185 * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3186 * BPF program itself can be non-sleepable, yet, because it's transitively
3187 * reachable through BPF link, its freeing has to be delayed until after RCU
3188 * Tasks Trace GP.
3189 */
bpf_link_init_sleepable(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type,bool sleepable)3190 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3191 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3192 enum bpf_attach_type attach_type, bool sleepable)
3193 {
3194 WARN_ON(ops->dealloc && ops->dealloc_deferred);
3195 atomic64_set(&link->refcnt, 1);
3196 link->type = type;
3197 link->sleepable = sleepable;
3198 link->id = 0;
3199 link->ops = ops;
3200 link->prog = prog;
3201 link->attach_type = attach_type;
3202 }
3203
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type)3204 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3205 const struct bpf_link_ops *ops, struct bpf_prog *prog,
3206 enum bpf_attach_type attach_type)
3207 {
3208 bpf_link_init_sleepable(link, type, ops, prog, attach_type, false);
3209 }
3210
bpf_link_free_id(int id)3211 static void bpf_link_free_id(int id)
3212 {
3213 if (!id)
3214 return;
3215
3216 spin_lock_bh(&link_idr_lock);
3217 idr_remove(&link_idr, id);
3218 spin_unlock_bh(&link_idr_lock);
3219 }
3220
3221 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3222 * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3223 * anon_inode's release() call. This helper marks bpf_link as
3224 * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3225 * is not decremented, it's the responsibility of a calling code that failed
3226 * to complete bpf_link initialization.
3227 * This helper eventually calls link's dealloc callback, but does not call
3228 * link's release callback.
3229 */
bpf_link_cleanup(struct bpf_link_primer * primer)3230 void bpf_link_cleanup(struct bpf_link_primer *primer)
3231 {
3232 primer->link->prog = NULL;
3233 bpf_link_free_id(primer->id);
3234 fput(primer->file);
3235 put_unused_fd(primer->fd);
3236 }
3237
bpf_link_inc(struct bpf_link * link)3238 void bpf_link_inc(struct bpf_link *link)
3239 {
3240 atomic64_inc(&link->refcnt);
3241 }
3242
bpf_link_dealloc(struct bpf_link * link)3243 static void bpf_link_dealloc(struct bpf_link *link)
3244 {
3245 /* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3246 if (link->prog)
3247 bpf_prog_put(link->prog);
3248
3249 /* free bpf_link and its containing memory */
3250 if (link->ops->dealloc_deferred)
3251 link->ops->dealloc_deferred(link);
3252 else
3253 link->ops->dealloc(link);
3254 }
3255
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3256 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3257 {
3258 struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3259
3260 bpf_link_dealloc(link);
3261 }
3262
bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head * rcu)3263 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
3264 {
3265 if (rcu_trace_implies_rcu_gp())
3266 bpf_link_defer_dealloc_rcu_gp(rcu);
3267 else
3268 call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
3269 }
3270
3271 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3272 static void bpf_link_free(struct bpf_link *link)
3273 {
3274 const struct bpf_link_ops *ops = link->ops;
3275
3276 bpf_link_free_id(link->id);
3277 /* detach BPF program, clean up used resources */
3278 if (link->prog)
3279 ops->release(link);
3280 if (ops->dealloc_deferred) {
3281 /* Schedule BPF link deallocation, which will only then
3282 * trigger putting BPF program refcount.
3283 * If underlying BPF program is sleepable or BPF link's target
3284 * attach hookpoint is sleepable or otherwise requires RCU GPs
3285 * to ensure link and its underlying BPF program is not
3286 * reachable anymore, we need to first wait for RCU tasks
3287 * trace sync, and then go through "classic" RCU grace period
3288 */
3289 if (link->sleepable || (link->prog && link->prog->sleepable))
3290 call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
3291 else
3292 call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3293 } else if (ops->dealloc) {
3294 bpf_link_dealloc(link);
3295 }
3296 }
3297
bpf_link_put_deferred(struct work_struct * work)3298 static void bpf_link_put_deferred(struct work_struct *work)
3299 {
3300 struct bpf_link *link = container_of(work, struct bpf_link, work);
3301
3302 bpf_link_free(link);
3303 }
3304
3305 /* bpf_link_put might be called from atomic context. It needs to be called
3306 * from sleepable context in order to acquire sleeping locks during the process.
3307 */
bpf_link_put(struct bpf_link * link)3308 void bpf_link_put(struct bpf_link *link)
3309 {
3310 if (!atomic64_dec_and_test(&link->refcnt))
3311 return;
3312
3313 INIT_WORK(&link->work, bpf_link_put_deferred);
3314 schedule_work(&link->work);
3315 }
3316 EXPORT_SYMBOL(bpf_link_put);
3317
bpf_link_put_direct(struct bpf_link * link)3318 static void bpf_link_put_direct(struct bpf_link *link)
3319 {
3320 if (!atomic64_dec_and_test(&link->refcnt))
3321 return;
3322 bpf_link_free(link);
3323 }
3324
bpf_link_release(struct inode * inode,struct file * filp)3325 static int bpf_link_release(struct inode *inode, struct file *filp)
3326 {
3327 struct bpf_link *link = filp->private_data;
3328
3329 bpf_link_put_direct(link);
3330 return 0;
3331 }
3332
3333 #ifdef CONFIG_PROC_FS
3334 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3335 #define BPF_MAP_TYPE(_id, _ops)
3336 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3337 static const char *bpf_link_type_strs[] = {
3338 [BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3339 #include <linux/bpf_types.h>
3340 };
3341 #undef BPF_PROG_TYPE
3342 #undef BPF_MAP_TYPE
3343 #undef BPF_LINK_TYPE
3344
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3345 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3346 {
3347 const struct bpf_link *link = filp->private_data;
3348 const struct bpf_prog *prog = link->prog;
3349 enum bpf_link_type type = link->type;
3350 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3351
3352 if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3353 if (link->type == BPF_LINK_TYPE_KPROBE_MULTI)
3354 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ?
3355 "kretprobe_multi" : "kprobe_multi");
3356 else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI)
3357 seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ?
3358 "uretprobe_multi" : "uprobe_multi");
3359 else
3360 seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3361 } else {
3362 WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3363 seq_printf(m, "link_type:\t<%u>\n", type);
3364 }
3365 seq_printf(m, "link_id:\t%u\n", link->id);
3366
3367 if (prog) {
3368 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3369 seq_printf(m,
3370 "prog_tag:\t%s\n"
3371 "prog_id:\t%u\n",
3372 prog_tag,
3373 prog->aux->id);
3374 }
3375 if (link->ops->show_fdinfo)
3376 link->ops->show_fdinfo(link, m);
3377 }
3378 #endif
3379
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3380 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3381 {
3382 struct bpf_link *link = file->private_data;
3383
3384 return link->ops->poll(file, pts);
3385 }
3386
3387 static const struct file_operations bpf_link_fops = {
3388 #ifdef CONFIG_PROC_FS
3389 .show_fdinfo = bpf_link_show_fdinfo,
3390 #endif
3391 .release = bpf_link_release,
3392 .read = bpf_dummy_read,
3393 .write = bpf_dummy_write,
3394 };
3395
3396 static const struct file_operations bpf_link_fops_poll = {
3397 #ifdef CONFIG_PROC_FS
3398 .show_fdinfo = bpf_link_show_fdinfo,
3399 #endif
3400 .release = bpf_link_release,
3401 .read = bpf_dummy_read,
3402 .write = bpf_dummy_write,
3403 .poll = bpf_link_poll,
3404 };
3405
bpf_link_alloc_id(struct bpf_link * link)3406 static int bpf_link_alloc_id(struct bpf_link *link)
3407 {
3408 int id;
3409
3410 idr_preload(GFP_KERNEL);
3411 spin_lock_bh(&link_idr_lock);
3412 id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3413 spin_unlock_bh(&link_idr_lock);
3414 idr_preload_end();
3415
3416 return id;
3417 }
3418
3419 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3420 * reserving unused FD and allocating ID from link_idr. This is to be paired
3421 * with bpf_link_settle() to install FD and ID and expose bpf_link to
3422 * user-space, if bpf_link is successfully attached. If not, bpf_link and
3423 * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3424 * transient state is passed around in struct bpf_link_primer.
3425 * This is preferred way to create and initialize bpf_link, especially when
3426 * there are complicated and expensive operations in between creating bpf_link
3427 * itself and attaching it to BPF hook. By using bpf_link_prime() and
3428 * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3429 * expensive (and potentially failing) roll back operations in a rare case
3430 * that file, FD, or ID can't be allocated.
3431 */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3432 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3433 {
3434 struct file *file;
3435 int fd, id;
3436
3437 fd = get_unused_fd_flags(O_CLOEXEC);
3438 if (fd < 0)
3439 return fd;
3440
3441
3442 id = bpf_link_alloc_id(link);
3443 if (id < 0) {
3444 put_unused_fd(fd);
3445 return id;
3446 }
3447
3448 file = anon_inode_getfile("bpf_link",
3449 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3450 link, O_CLOEXEC);
3451 if (IS_ERR(file)) {
3452 bpf_link_free_id(id);
3453 put_unused_fd(fd);
3454 return PTR_ERR(file);
3455 }
3456
3457 primer->link = link;
3458 primer->file = file;
3459 primer->fd = fd;
3460 primer->id = id;
3461 return 0;
3462 }
3463
bpf_link_settle(struct bpf_link_primer * primer)3464 int bpf_link_settle(struct bpf_link_primer *primer)
3465 {
3466 /* make bpf_link fetchable by ID */
3467 spin_lock_bh(&link_idr_lock);
3468 primer->link->id = primer->id;
3469 spin_unlock_bh(&link_idr_lock);
3470 /* make bpf_link fetchable by FD */
3471 fd_install(primer->fd, primer->file);
3472 /* pass through installed FD */
3473 return primer->fd;
3474 }
3475
bpf_link_new_fd(struct bpf_link * link)3476 int bpf_link_new_fd(struct bpf_link *link)
3477 {
3478 return anon_inode_getfd("bpf-link",
3479 link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3480 link, O_CLOEXEC);
3481 }
3482
bpf_link_get_from_fd(u32 ufd)3483 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3484 {
3485 CLASS(fd, f)(ufd);
3486 struct bpf_link *link;
3487
3488 if (fd_empty(f))
3489 return ERR_PTR(-EBADF);
3490 if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3491 return ERR_PTR(-EINVAL);
3492
3493 link = fd_file(f)->private_data;
3494 bpf_link_inc(link);
3495 return link;
3496 }
3497 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL");
3498
bpf_tracing_link_release(struct bpf_link * link)3499 static void bpf_tracing_link_release(struct bpf_link *link)
3500 {
3501 struct bpf_tracing_link *tr_link =
3502 container_of(link, struct bpf_tracing_link, link.link);
3503
3504 WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3505 tr_link->trampoline,
3506 tr_link->tgt_prog));
3507
3508 bpf_trampoline_put(tr_link->trampoline);
3509
3510 /* tgt_prog is NULL if target is a kernel function */
3511 if (tr_link->tgt_prog)
3512 bpf_prog_put(tr_link->tgt_prog);
3513 }
3514
bpf_tracing_link_dealloc(struct bpf_link * link)3515 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3516 {
3517 struct bpf_tracing_link *tr_link =
3518 container_of(link, struct bpf_tracing_link, link.link);
3519
3520 kfree(tr_link);
3521 }
3522
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3523 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3524 struct seq_file *seq)
3525 {
3526 struct bpf_tracing_link *tr_link =
3527 container_of(link, struct bpf_tracing_link, link.link);
3528 u32 target_btf_id, target_obj_id;
3529
3530 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3531 &target_obj_id, &target_btf_id);
3532 seq_printf(seq,
3533 "attach_type:\t%d\n"
3534 "target_obj_id:\t%u\n"
3535 "target_btf_id:\t%u\n"
3536 "cookie:\t%llu\n",
3537 link->attach_type,
3538 target_obj_id,
3539 target_btf_id,
3540 tr_link->link.cookie);
3541 }
3542
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3543 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3544 struct bpf_link_info *info)
3545 {
3546 struct bpf_tracing_link *tr_link =
3547 container_of(link, struct bpf_tracing_link, link.link);
3548
3549 info->tracing.attach_type = link->attach_type;
3550 info->tracing.cookie = tr_link->link.cookie;
3551 bpf_trampoline_unpack_key(tr_link->trampoline->key,
3552 &info->tracing.target_obj_id,
3553 &info->tracing.target_btf_id);
3554
3555 return 0;
3556 }
3557
3558 static const struct bpf_link_ops bpf_tracing_link_lops = {
3559 .release = bpf_tracing_link_release,
3560 .dealloc = bpf_tracing_link_dealloc,
3561 .show_fdinfo = bpf_tracing_link_show_fdinfo,
3562 .fill_link_info = bpf_tracing_link_fill_link_info,
3563 };
3564
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie,enum bpf_attach_type attach_type)3565 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3566 int tgt_prog_fd,
3567 u32 btf_id,
3568 u64 bpf_cookie,
3569 enum bpf_attach_type attach_type)
3570 {
3571 struct bpf_link_primer link_primer;
3572 struct bpf_prog *tgt_prog = NULL;
3573 struct bpf_trampoline *tr = NULL;
3574 struct bpf_tracing_link *link;
3575 u64 key = 0;
3576 int err;
3577
3578 switch (prog->type) {
3579 case BPF_PROG_TYPE_TRACING:
3580 if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3581 prog->expected_attach_type != BPF_TRACE_FEXIT &&
3582 prog->expected_attach_type != BPF_MODIFY_RETURN) {
3583 err = -EINVAL;
3584 goto out_put_prog;
3585 }
3586 break;
3587 case BPF_PROG_TYPE_EXT:
3588 if (prog->expected_attach_type != 0) {
3589 err = -EINVAL;
3590 goto out_put_prog;
3591 }
3592 break;
3593 case BPF_PROG_TYPE_LSM:
3594 if (prog->expected_attach_type != BPF_LSM_MAC) {
3595 err = -EINVAL;
3596 goto out_put_prog;
3597 }
3598 break;
3599 default:
3600 err = -EINVAL;
3601 goto out_put_prog;
3602 }
3603
3604 if (!!tgt_prog_fd != !!btf_id) {
3605 err = -EINVAL;
3606 goto out_put_prog;
3607 }
3608
3609 if (tgt_prog_fd) {
3610 /*
3611 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3612 * part would be changed to implement the same for
3613 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3614 * attach_tracing_prog flag is set.
3615 */
3616 if (prog->type != BPF_PROG_TYPE_EXT) {
3617 err = -EINVAL;
3618 goto out_put_prog;
3619 }
3620
3621 tgt_prog = bpf_prog_get(tgt_prog_fd);
3622 if (IS_ERR(tgt_prog)) {
3623 err = PTR_ERR(tgt_prog);
3624 tgt_prog = NULL;
3625 goto out_put_prog;
3626 }
3627
3628 key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3629 }
3630
3631 link = kzalloc(sizeof(*link), GFP_USER);
3632 if (!link) {
3633 err = -ENOMEM;
3634 goto out_put_prog;
3635 }
3636 bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3637 &bpf_tracing_link_lops, prog, attach_type);
3638
3639 link->link.cookie = bpf_cookie;
3640
3641 mutex_lock(&prog->aux->dst_mutex);
3642
3643 /* There are a few possible cases here:
3644 *
3645 * - if prog->aux->dst_trampoline is set, the program was just loaded
3646 * and not yet attached to anything, so we can use the values stored
3647 * in prog->aux
3648 *
3649 * - if prog->aux->dst_trampoline is NULL, the program has already been
3650 * attached to a target and its initial target was cleared (below)
3651 *
3652 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3653 * target_btf_id using the link_create API.
3654 *
3655 * - if tgt_prog == NULL when this function was called using the old
3656 * raw_tracepoint_open API, and we need a target from prog->aux
3657 *
3658 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3659 * was detached and is going for re-attachment.
3660 *
3661 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3662 * are NULL, then program was already attached and user did not provide
3663 * tgt_prog_fd so we have no way to find out or create trampoline
3664 */
3665 if (!prog->aux->dst_trampoline && !tgt_prog) {
3666 /*
3667 * Allow re-attach for TRACING and LSM programs. If it's
3668 * currently linked, bpf_trampoline_link_prog will fail.
3669 * EXT programs need to specify tgt_prog_fd, so they
3670 * re-attach in separate code path.
3671 */
3672 if (prog->type != BPF_PROG_TYPE_TRACING &&
3673 prog->type != BPF_PROG_TYPE_LSM) {
3674 err = -EINVAL;
3675 goto out_unlock;
3676 }
3677 /* We can allow re-attach only if we have valid attach_btf. */
3678 if (!prog->aux->attach_btf) {
3679 err = -EINVAL;
3680 goto out_unlock;
3681 }
3682 btf_id = prog->aux->attach_btf_id;
3683 key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3684 }
3685
3686 if (!prog->aux->dst_trampoline ||
3687 (key && key != prog->aux->dst_trampoline->key)) {
3688 /* If there is no saved target, or the specified target is
3689 * different from the destination specified at load time, we
3690 * need a new trampoline and a check for compatibility
3691 */
3692 struct bpf_attach_target_info tgt_info = {};
3693
3694 err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3695 &tgt_info);
3696 if (err)
3697 goto out_unlock;
3698
3699 if (tgt_info.tgt_mod) {
3700 module_put(prog->aux->mod);
3701 prog->aux->mod = tgt_info.tgt_mod;
3702 }
3703
3704 tr = bpf_trampoline_get(key, &tgt_info);
3705 if (!tr) {
3706 err = -ENOMEM;
3707 goto out_unlock;
3708 }
3709 } else {
3710 /* The caller didn't specify a target, or the target was the
3711 * same as the destination supplied during program load. This
3712 * means we can reuse the trampoline and reference from program
3713 * load time, and there is no need to allocate a new one. This
3714 * can only happen once for any program, as the saved values in
3715 * prog->aux are cleared below.
3716 */
3717 tr = prog->aux->dst_trampoline;
3718 tgt_prog = prog->aux->dst_prog;
3719 }
3720
3721 err = bpf_link_prime(&link->link.link, &link_primer);
3722 if (err)
3723 goto out_unlock;
3724
3725 err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3726 if (err) {
3727 bpf_link_cleanup(&link_primer);
3728 link = NULL;
3729 goto out_unlock;
3730 }
3731
3732 link->tgt_prog = tgt_prog;
3733 link->trampoline = tr;
3734
3735 /* Always clear the trampoline and target prog from prog->aux to make
3736 * sure the original attach destination is not kept alive after a
3737 * program is (re-)attached to another target.
3738 */
3739 if (prog->aux->dst_prog &&
3740 (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3741 /* got extra prog ref from syscall, or attaching to different prog */
3742 bpf_prog_put(prog->aux->dst_prog);
3743 if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3744 /* we allocated a new trampoline, so free the old one */
3745 bpf_trampoline_put(prog->aux->dst_trampoline);
3746
3747 prog->aux->dst_prog = NULL;
3748 prog->aux->dst_trampoline = NULL;
3749 mutex_unlock(&prog->aux->dst_mutex);
3750
3751 return bpf_link_settle(&link_primer);
3752 out_unlock:
3753 if (tr && tr != prog->aux->dst_trampoline)
3754 bpf_trampoline_put(tr);
3755 mutex_unlock(&prog->aux->dst_mutex);
3756 kfree(link);
3757 out_put_prog:
3758 if (tgt_prog_fd && tgt_prog)
3759 bpf_prog_put(tgt_prog);
3760 return err;
3761 }
3762
bpf_raw_tp_link_release(struct bpf_link * link)3763 static void bpf_raw_tp_link_release(struct bpf_link *link)
3764 {
3765 struct bpf_raw_tp_link *raw_tp =
3766 container_of(link, struct bpf_raw_tp_link, link);
3767
3768 bpf_probe_unregister(raw_tp->btp, raw_tp);
3769 bpf_put_raw_tracepoint(raw_tp->btp);
3770 }
3771
bpf_raw_tp_link_dealloc(struct bpf_link * link)3772 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3773 {
3774 struct bpf_raw_tp_link *raw_tp =
3775 container_of(link, struct bpf_raw_tp_link, link);
3776
3777 kfree(raw_tp);
3778 }
3779
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3780 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3781 struct seq_file *seq)
3782 {
3783 struct bpf_raw_tp_link *raw_tp_link =
3784 container_of(link, struct bpf_raw_tp_link, link);
3785
3786 seq_printf(seq,
3787 "tp_name:\t%s\n"
3788 "cookie:\t%llu\n",
3789 raw_tp_link->btp->tp->name,
3790 raw_tp_link->cookie);
3791 }
3792
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3793 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3794 u32 len)
3795 {
3796 if (ulen >= len + 1) {
3797 if (copy_to_user(ubuf, buf, len + 1))
3798 return -EFAULT;
3799 } else {
3800 char zero = '\0';
3801
3802 if (copy_to_user(ubuf, buf, ulen - 1))
3803 return -EFAULT;
3804 if (put_user(zero, ubuf + ulen - 1))
3805 return -EFAULT;
3806 return -ENOSPC;
3807 }
3808
3809 return 0;
3810 }
3811
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3812 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3813 struct bpf_link_info *info)
3814 {
3815 struct bpf_raw_tp_link *raw_tp_link =
3816 container_of(link, struct bpf_raw_tp_link, link);
3817 char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3818 const char *tp_name = raw_tp_link->btp->tp->name;
3819 u32 ulen = info->raw_tracepoint.tp_name_len;
3820 size_t tp_len = strlen(tp_name);
3821
3822 if (!ulen ^ !ubuf)
3823 return -EINVAL;
3824
3825 info->raw_tracepoint.tp_name_len = tp_len + 1;
3826 info->raw_tracepoint.cookie = raw_tp_link->cookie;
3827
3828 if (!ubuf)
3829 return 0;
3830
3831 return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3832 }
3833
3834 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3835 .release = bpf_raw_tp_link_release,
3836 .dealloc_deferred = bpf_raw_tp_link_dealloc,
3837 .show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3838 .fill_link_info = bpf_raw_tp_link_fill_link_info,
3839 };
3840
3841 #ifdef CONFIG_PERF_EVENTS
3842 struct bpf_perf_link {
3843 struct bpf_link link;
3844 struct file *perf_file;
3845 };
3846
bpf_perf_link_release(struct bpf_link * link)3847 static void bpf_perf_link_release(struct bpf_link *link)
3848 {
3849 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3850 struct perf_event *event = perf_link->perf_file->private_data;
3851
3852 perf_event_free_bpf_prog(event);
3853 fput(perf_link->perf_file);
3854 }
3855
bpf_perf_link_dealloc(struct bpf_link * link)3856 static void bpf_perf_link_dealloc(struct bpf_link *link)
3857 {
3858 struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3859
3860 kfree(perf_link);
3861 }
3862
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)3863 static int bpf_perf_link_fill_common(const struct perf_event *event,
3864 char __user *uname, u32 *ulenp,
3865 u64 *probe_offset, u64 *probe_addr,
3866 u32 *fd_type, unsigned long *missed)
3867 {
3868 const char *buf;
3869 u32 prog_id, ulen;
3870 size_t len;
3871 int err;
3872
3873 ulen = *ulenp;
3874 if (!ulen ^ !uname)
3875 return -EINVAL;
3876
3877 err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3878 probe_offset, probe_addr, missed);
3879 if (err)
3880 return err;
3881
3882 if (buf) {
3883 len = strlen(buf);
3884 *ulenp = len + 1;
3885 } else {
3886 *ulenp = 1;
3887 }
3888 if (!uname)
3889 return 0;
3890
3891 if (buf) {
3892 err = bpf_copy_to_user(uname, buf, ulen, len);
3893 if (err)
3894 return err;
3895 } else {
3896 char zero = '\0';
3897
3898 if (put_user(zero, uname))
3899 return -EFAULT;
3900 }
3901 return 0;
3902 }
3903
3904 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3905 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3906 struct bpf_link_info *info)
3907 {
3908 unsigned long missed;
3909 char __user *uname;
3910 u64 addr, offset;
3911 u32 ulen, type;
3912 int err;
3913
3914 uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3915 ulen = info->perf_event.kprobe.name_len;
3916 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3917 &type, &missed);
3918 if (err)
3919 return err;
3920 if (type == BPF_FD_TYPE_KRETPROBE)
3921 info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3922 else
3923 info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3924 info->perf_event.kprobe.name_len = ulen;
3925 info->perf_event.kprobe.offset = offset;
3926 info->perf_event.kprobe.missed = missed;
3927 if (!kallsyms_show_value(current_cred()))
3928 addr = 0;
3929 info->perf_event.kprobe.addr = addr;
3930 info->perf_event.kprobe.cookie = event->bpf_cookie;
3931 return 0;
3932 }
3933
bpf_perf_link_fdinfo_kprobe(const struct perf_event * event,struct seq_file * seq)3934 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event,
3935 struct seq_file *seq)
3936 {
3937 const char *name;
3938 int err;
3939 u32 prog_id, type;
3940 u64 offset, addr;
3941 unsigned long missed;
3942
3943 err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
3944 &offset, &addr, &missed);
3945 if (err)
3946 return;
3947
3948 seq_printf(seq,
3949 "name:\t%s\n"
3950 "offset:\t%#llx\n"
3951 "missed:\t%lu\n"
3952 "addr:\t%#llx\n"
3953 "event_type:\t%s\n"
3954 "cookie:\t%llu\n",
3955 name, offset, missed, addr,
3956 type == BPF_FD_TYPE_KRETPROBE ? "kretprobe" : "kprobe",
3957 event->bpf_cookie);
3958 }
3959 #endif
3960
3961 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3962 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3963 struct bpf_link_info *info)
3964 {
3965 u64 ref_ctr_offset, offset;
3966 char __user *uname;
3967 u32 ulen, type;
3968 int err;
3969
3970 uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3971 ulen = info->perf_event.uprobe.name_len;
3972 err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset,
3973 &type, NULL);
3974 if (err)
3975 return err;
3976
3977 if (type == BPF_FD_TYPE_URETPROBE)
3978 info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3979 else
3980 info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3981 info->perf_event.uprobe.name_len = ulen;
3982 info->perf_event.uprobe.offset = offset;
3983 info->perf_event.uprobe.cookie = event->bpf_cookie;
3984 info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset;
3985 return 0;
3986 }
3987
bpf_perf_link_fdinfo_uprobe(const struct perf_event * event,struct seq_file * seq)3988 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event,
3989 struct seq_file *seq)
3990 {
3991 const char *name;
3992 int err;
3993 u32 prog_id, type;
3994 u64 offset, ref_ctr_offset;
3995 unsigned long missed;
3996
3997 err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
3998 &offset, &ref_ctr_offset, &missed);
3999 if (err)
4000 return;
4001
4002 seq_printf(seq,
4003 "name:\t%s\n"
4004 "offset:\t%#llx\n"
4005 "ref_ctr_offset:\t%#llx\n"
4006 "event_type:\t%s\n"
4007 "cookie:\t%llu\n",
4008 name, offset, ref_ctr_offset,
4009 type == BPF_FD_TYPE_URETPROBE ? "uretprobe" : "uprobe",
4010 event->bpf_cookie);
4011 }
4012 #endif
4013
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)4014 static int bpf_perf_link_fill_probe(const struct perf_event *event,
4015 struct bpf_link_info *info)
4016 {
4017 #ifdef CONFIG_KPROBE_EVENTS
4018 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4019 return bpf_perf_link_fill_kprobe(event, info);
4020 #endif
4021 #ifdef CONFIG_UPROBE_EVENTS
4022 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4023 return bpf_perf_link_fill_uprobe(event, info);
4024 #endif
4025 return -EOPNOTSUPP;
4026 }
4027
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)4028 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
4029 struct bpf_link_info *info)
4030 {
4031 char __user *uname;
4032 u32 ulen;
4033 int err;
4034
4035 uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
4036 ulen = info->perf_event.tracepoint.name_len;
4037 err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
4038 if (err)
4039 return err;
4040
4041 info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
4042 info->perf_event.tracepoint.name_len = ulen;
4043 info->perf_event.tracepoint.cookie = event->bpf_cookie;
4044 return 0;
4045 }
4046
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)4047 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
4048 struct bpf_link_info *info)
4049 {
4050 info->perf_event.event.type = event->attr.type;
4051 info->perf_event.event.config = event->attr.config;
4052 info->perf_event.event.cookie = event->bpf_cookie;
4053 info->perf_event.type = BPF_PERF_EVENT_EVENT;
4054 return 0;
4055 }
4056
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)4057 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
4058 struct bpf_link_info *info)
4059 {
4060 struct bpf_perf_link *perf_link;
4061 const struct perf_event *event;
4062
4063 perf_link = container_of(link, struct bpf_perf_link, link);
4064 event = perf_get_event(perf_link->perf_file);
4065 if (IS_ERR(event))
4066 return PTR_ERR(event);
4067
4068 switch (event->prog->type) {
4069 case BPF_PROG_TYPE_PERF_EVENT:
4070 return bpf_perf_link_fill_perf_event(event, info);
4071 case BPF_PROG_TYPE_TRACEPOINT:
4072 return bpf_perf_link_fill_tracepoint(event, info);
4073 case BPF_PROG_TYPE_KPROBE:
4074 return bpf_perf_link_fill_probe(event, info);
4075 default:
4076 return -EOPNOTSUPP;
4077 }
4078 }
4079
bpf_perf_event_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4080 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event,
4081 struct seq_file *seq)
4082 {
4083 seq_printf(seq,
4084 "type:\t%u\n"
4085 "config:\t%llu\n"
4086 "event_type:\t%s\n"
4087 "cookie:\t%llu\n",
4088 event->attr.type, event->attr.config,
4089 "event", event->bpf_cookie);
4090 }
4091
bpf_tracepoint_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4092 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event,
4093 struct seq_file *seq)
4094 {
4095 int err;
4096 const char *name;
4097 u32 prog_id;
4098
4099 err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL,
4100 NULL, NULL);
4101 if (err)
4102 return;
4103
4104 seq_printf(seq,
4105 "tp_name:\t%s\n"
4106 "event_type:\t%s\n"
4107 "cookie:\t%llu\n",
4108 name, "tracepoint", event->bpf_cookie);
4109 }
4110
bpf_probe_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4111 static void bpf_probe_link_show_fdinfo(const struct perf_event *event,
4112 struct seq_file *seq)
4113 {
4114 #ifdef CONFIG_KPROBE_EVENTS
4115 if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4116 return bpf_perf_link_fdinfo_kprobe(event, seq);
4117 #endif
4118
4119 #ifdef CONFIG_UPROBE_EVENTS
4120 if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4121 return bpf_perf_link_fdinfo_uprobe(event, seq);
4122 #endif
4123 }
4124
bpf_perf_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)4125 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link,
4126 struct seq_file *seq)
4127 {
4128 struct bpf_perf_link *perf_link;
4129 const struct perf_event *event;
4130
4131 perf_link = container_of(link, struct bpf_perf_link, link);
4132 event = perf_get_event(perf_link->perf_file);
4133 if (IS_ERR(event))
4134 return;
4135
4136 switch (event->prog->type) {
4137 case BPF_PROG_TYPE_PERF_EVENT:
4138 return bpf_perf_event_link_show_fdinfo(event, seq);
4139 case BPF_PROG_TYPE_TRACEPOINT:
4140 return bpf_tracepoint_link_show_fdinfo(event, seq);
4141 case BPF_PROG_TYPE_KPROBE:
4142 return bpf_probe_link_show_fdinfo(event, seq);
4143 default:
4144 return;
4145 }
4146 }
4147
4148 static const struct bpf_link_ops bpf_perf_link_lops = {
4149 .release = bpf_perf_link_release,
4150 .dealloc = bpf_perf_link_dealloc,
4151 .fill_link_info = bpf_perf_link_fill_link_info,
4152 .show_fdinfo = bpf_perf_link_show_fdinfo,
4153 };
4154
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4155 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4156 {
4157 struct bpf_link_primer link_primer;
4158 struct bpf_perf_link *link;
4159 struct perf_event *event;
4160 struct file *perf_file;
4161 int err;
4162
4163 if (attr->link_create.flags)
4164 return -EINVAL;
4165
4166 perf_file = perf_event_get(attr->link_create.target_fd);
4167 if (IS_ERR(perf_file))
4168 return PTR_ERR(perf_file);
4169
4170 link = kzalloc(sizeof(*link), GFP_USER);
4171 if (!link) {
4172 err = -ENOMEM;
4173 goto out_put_file;
4174 }
4175 bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog,
4176 attr->link_create.attach_type);
4177 link->perf_file = perf_file;
4178
4179 err = bpf_link_prime(&link->link, &link_primer);
4180 if (err) {
4181 kfree(link);
4182 goto out_put_file;
4183 }
4184
4185 event = perf_file->private_data;
4186 err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
4187 if (err) {
4188 bpf_link_cleanup(&link_primer);
4189 goto out_put_file;
4190 }
4191 /* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
4192 bpf_prog_inc(prog);
4193
4194 return bpf_link_settle(&link_primer);
4195
4196 out_put_file:
4197 fput(perf_file);
4198 return err;
4199 }
4200 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4201 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4202 {
4203 return -EOPNOTSUPP;
4204 }
4205 #endif /* CONFIG_PERF_EVENTS */
4206
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie,enum bpf_attach_type attach_type)4207 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
4208 const char __user *user_tp_name, u64 cookie,
4209 enum bpf_attach_type attach_type)
4210 {
4211 struct bpf_link_primer link_primer;
4212 struct bpf_raw_tp_link *link;
4213 struct bpf_raw_event_map *btp;
4214 const char *tp_name;
4215 char buf[128];
4216 int err;
4217
4218 switch (prog->type) {
4219 case BPF_PROG_TYPE_TRACING:
4220 case BPF_PROG_TYPE_EXT:
4221 case BPF_PROG_TYPE_LSM:
4222 if (user_tp_name)
4223 /* The attach point for this category of programs
4224 * should be specified via btf_id during program load.
4225 */
4226 return -EINVAL;
4227 if (prog->type == BPF_PROG_TYPE_TRACING &&
4228 prog->expected_attach_type == BPF_TRACE_RAW_TP) {
4229 tp_name = prog->aux->attach_func_name;
4230 break;
4231 }
4232 return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type);
4233 case BPF_PROG_TYPE_RAW_TRACEPOINT:
4234 case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
4235 if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
4236 return -EFAULT;
4237 buf[sizeof(buf) - 1] = 0;
4238 tp_name = buf;
4239 break;
4240 default:
4241 return -EINVAL;
4242 }
4243
4244 btp = bpf_get_raw_tracepoint(tp_name);
4245 if (!btp)
4246 return -ENOENT;
4247
4248 link = kzalloc(sizeof(*link), GFP_USER);
4249 if (!link) {
4250 err = -ENOMEM;
4251 goto out_put_btp;
4252 }
4253 bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
4254 &bpf_raw_tp_link_lops, prog, attach_type,
4255 tracepoint_is_faultable(btp->tp));
4256 link->btp = btp;
4257 link->cookie = cookie;
4258
4259 err = bpf_link_prime(&link->link, &link_primer);
4260 if (err) {
4261 kfree(link);
4262 goto out_put_btp;
4263 }
4264
4265 err = bpf_probe_register(link->btp, link);
4266 if (err) {
4267 bpf_link_cleanup(&link_primer);
4268 goto out_put_btp;
4269 }
4270
4271 return bpf_link_settle(&link_primer);
4272
4273 out_put_btp:
4274 bpf_put_raw_tracepoint(btp);
4275 return err;
4276 }
4277
4278 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4279
bpf_raw_tracepoint_open(const union bpf_attr * attr)4280 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4281 {
4282 struct bpf_prog *prog;
4283 void __user *tp_name;
4284 __u64 cookie;
4285 int fd;
4286
4287 if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4288 return -EINVAL;
4289
4290 prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4291 if (IS_ERR(prog))
4292 return PTR_ERR(prog);
4293
4294 tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4295 cookie = attr->raw_tracepoint.cookie;
4296 fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type);
4297 if (fd < 0)
4298 bpf_prog_put(prog);
4299 return fd;
4300 }
4301
4302 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4303 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4304 {
4305 switch (attach_type) {
4306 case BPF_CGROUP_INET_INGRESS:
4307 case BPF_CGROUP_INET_EGRESS:
4308 return BPF_PROG_TYPE_CGROUP_SKB;
4309 case BPF_CGROUP_INET_SOCK_CREATE:
4310 case BPF_CGROUP_INET_SOCK_RELEASE:
4311 case BPF_CGROUP_INET4_POST_BIND:
4312 case BPF_CGROUP_INET6_POST_BIND:
4313 return BPF_PROG_TYPE_CGROUP_SOCK;
4314 case BPF_CGROUP_INET4_BIND:
4315 case BPF_CGROUP_INET6_BIND:
4316 case BPF_CGROUP_INET4_CONNECT:
4317 case BPF_CGROUP_INET6_CONNECT:
4318 case BPF_CGROUP_UNIX_CONNECT:
4319 case BPF_CGROUP_INET4_GETPEERNAME:
4320 case BPF_CGROUP_INET6_GETPEERNAME:
4321 case BPF_CGROUP_UNIX_GETPEERNAME:
4322 case BPF_CGROUP_INET4_GETSOCKNAME:
4323 case BPF_CGROUP_INET6_GETSOCKNAME:
4324 case BPF_CGROUP_UNIX_GETSOCKNAME:
4325 case BPF_CGROUP_UDP4_SENDMSG:
4326 case BPF_CGROUP_UDP6_SENDMSG:
4327 case BPF_CGROUP_UNIX_SENDMSG:
4328 case BPF_CGROUP_UDP4_RECVMSG:
4329 case BPF_CGROUP_UDP6_RECVMSG:
4330 case BPF_CGROUP_UNIX_RECVMSG:
4331 return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4332 case BPF_CGROUP_SOCK_OPS:
4333 return BPF_PROG_TYPE_SOCK_OPS;
4334 case BPF_CGROUP_DEVICE:
4335 return BPF_PROG_TYPE_CGROUP_DEVICE;
4336 case BPF_SK_MSG_VERDICT:
4337 return BPF_PROG_TYPE_SK_MSG;
4338 case BPF_SK_SKB_STREAM_PARSER:
4339 case BPF_SK_SKB_STREAM_VERDICT:
4340 case BPF_SK_SKB_VERDICT:
4341 return BPF_PROG_TYPE_SK_SKB;
4342 case BPF_LIRC_MODE2:
4343 return BPF_PROG_TYPE_LIRC_MODE2;
4344 case BPF_FLOW_DISSECTOR:
4345 return BPF_PROG_TYPE_FLOW_DISSECTOR;
4346 case BPF_CGROUP_SYSCTL:
4347 return BPF_PROG_TYPE_CGROUP_SYSCTL;
4348 case BPF_CGROUP_GETSOCKOPT:
4349 case BPF_CGROUP_SETSOCKOPT:
4350 return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4351 case BPF_TRACE_ITER:
4352 case BPF_TRACE_RAW_TP:
4353 case BPF_TRACE_FENTRY:
4354 case BPF_TRACE_FEXIT:
4355 case BPF_MODIFY_RETURN:
4356 return BPF_PROG_TYPE_TRACING;
4357 case BPF_LSM_MAC:
4358 return BPF_PROG_TYPE_LSM;
4359 case BPF_SK_LOOKUP:
4360 return BPF_PROG_TYPE_SK_LOOKUP;
4361 case BPF_XDP:
4362 return BPF_PROG_TYPE_XDP;
4363 case BPF_LSM_CGROUP:
4364 return BPF_PROG_TYPE_LSM;
4365 case BPF_TCX_INGRESS:
4366 case BPF_TCX_EGRESS:
4367 case BPF_NETKIT_PRIMARY:
4368 case BPF_NETKIT_PEER:
4369 return BPF_PROG_TYPE_SCHED_CLS;
4370 default:
4371 return BPF_PROG_TYPE_UNSPEC;
4372 }
4373 }
4374
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4375 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4376 enum bpf_attach_type attach_type)
4377 {
4378 enum bpf_prog_type ptype;
4379
4380 switch (prog->type) {
4381 case BPF_PROG_TYPE_CGROUP_SOCK:
4382 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4383 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4384 case BPF_PROG_TYPE_SK_LOOKUP:
4385 return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4386 case BPF_PROG_TYPE_CGROUP_SKB:
4387 if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4388 /* cg-skb progs can be loaded by unpriv user.
4389 * check permissions at attach time.
4390 */
4391 return -EPERM;
4392
4393 ptype = attach_type_to_prog_type(attach_type);
4394 if (prog->type != ptype)
4395 return -EINVAL;
4396
4397 return prog->enforce_expected_attach_type &&
4398 prog->expected_attach_type != attach_type ?
4399 -EINVAL : 0;
4400 case BPF_PROG_TYPE_EXT:
4401 return 0;
4402 case BPF_PROG_TYPE_NETFILTER:
4403 if (attach_type != BPF_NETFILTER)
4404 return -EINVAL;
4405 return 0;
4406 case BPF_PROG_TYPE_PERF_EVENT:
4407 case BPF_PROG_TYPE_TRACEPOINT:
4408 if (attach_type != BPF_PERF_EVENT)
4409 return -EINVAL;
4410 return 0;
4411 case BPF_PROG_TYPE_KPROBE:
4412 if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4413 attach_type != BPF_TRACE_KPROBE_MULTI)
4414 return -EINVAL;
4415 if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4416 attach_type != BPF_TRACE_KPROBE_SESSION)
4417 return -EINVAL;
4418 if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4419 attach_type != BPF_TRACE_UPROBE_MULTI)
4420 return -EINVAL;
4421 if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4422 attach_type != BPF_TRACE_UPROBE_SESSION)
4423 return -EINVAL;
4424 if (attach_type != BPF_PERF_EVENT &&
4425 attach_type != BPF_TRACE_KPROBE_MULTI &&
4426 attach_type != BPF_TRACE_KPROBE_SESSION &&
4427 attach_type != BPF_TRACE_UPROBE_MULTI &&
4428 attach_type != BPF_TRACE_UPROBE_SESSION)
4429 return -EINVAL;
4430 return 0;
4431 case BPF_PROG_TYPE_SCHED_CLS:
4432 if (attach_type != BPF_TCX_INGRESS &&
4433 attach_type != BPF_TCX_EGRESS &&
4434 attach_type != BPF_NETKIT_PRIMARY &&
4435 attach_type != BPF_NETKIT_PEER)
4436 return -EINVAL;
4437 return 0;
4438 default:
4439 ptype = attach_type_to_prog_type(attach_type);
4440 if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4441 return -EINVAL;
4442 return 0;
4443 }
4444 }
4445
is_cgroup_prog_type(enum bpf_prog_type ptype,enum bpf_attach_type atype,bool check_atype)4446 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype,
4447 bool check_atype)
4448 {
4449 switch (ptype) {
4450 case BPF_PROG_TYPE_CGROUP_DEVICE:
4451 case BPF_PROG_TYPE_CGROUP_SKB:
4452 case BPF_PROG_TYPE_CGROUP_SOCK:
4453 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4454 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4455 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4456 case BPF_PROG_TYPE_SOCK_OPS:
4457 return true;
4458 case BPF_PROG_TYPE_LSM:
4459 return check_atype ? atype == BPF_LSM_CGROUP : true;
4460 default:
4461 return false;
4462 }
4463 }
4464
4465 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4466
4467 #define BPF_F_ATTACH_MASK_BASE \
4468 (BPF_F_ALLOW_OVERRIDE | \
4469 BPF_F_ALLOW_MULTI | \
4470 BPF_F_REPLACE | \
4471 BPF_F_PREORDER)
4472
4473 #define BPF_F_ATTACH_MASK_MPROG \
4474 (BPF_F_REPLACE | \
4475 BPF_F_BEFORE | \
4476 BPF_F_AFTER | \
4477 BPF_F_ID | \
4478 BPF_F_LINK)
4479
bpf_prog_attach(const union bpf_attr * attr)4480 static int bpf_prog_attach(const union bpf_attr *attr)
4481 {
4482 enum bpf_prog_type ptype;
4483 struct bpf_prog *prog;
4484 int ret;
4485
4486 if (CHECK_ATTR(BPF_PROG_ATTACH))
4487 return -EINVAL;
4488
4489 ptype = attach_type_to_prog_type(attr->attach_type);
4490 if (ptype == BPF_PROG_TYPE_UNSPEC)
4491 return -EINVAL;
4492 if (bpf_mprog_supported(ptype)) {
4493 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4494 return -EINVAL;
4495 } else if (is_cgroup_prog_type(ptype, 0, false)) {
4496 if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG))
4497 return -EINVAL;
4498 } else {
4499 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4500 return -EINVAL;
4501 if (attr->relative_fd ||
4502 attr->expected_revision)
4503 return -EINVAL;
4504 }
4505
4506 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4507 if (IS_ERR(prog))
4508 return PTR_ERR(prog);
4509
4510 if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4511 bpf_prog_put(prog);
4512 return -EINVAL;
4513 }
4514
4515 if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) {
4516 ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4517 goto out;
4518 }
4519
4520 switch (ptype) {
4521 case BPF_PROG_TYPE_SK_SKB:
4522 case BPF_PROG_TYPE_SK_MSG:
4523 ret = sock_map_get_from_fd(attr, prog);
4524 break;
4525 case BPF_PROG_TYPE_LIRC_MODE2:
4526 ret = lirc_prog_attach(attr, prog);
4527 break;
4528 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4529 ret = netns_bpf_prog_attach(attr, prog);
4530 break;
4531 case BPF_PROG_TYPE_SCHED_CLS:
4532 if (attr->attach_type == BPF_TCX_INGRESS ||
4533 attr->attach_type == BPF_TCX_EGRESS)
4534 ret = tcx_prog_attach(attr, prog);
4535 else
4536 ret = netkit_prog_attach(attr, prog);
4537 break;
4538 default:
4539 ret = -EINVAL;
4540 }
4541 out:
4542 if (ret)
4543 bpf_prog_put(prog);
4544 return ret;
4545 }
4546
4547 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4548
bpf_prog_detach(const union bpf_attr * attr)4549 static int bpf_prog_detach(const union bpf_attr *attr)
4550 {
4551 struct bpf_prog *prog = NULL;
4552 enum bpf_prog_type ptype;
4553 int ret;
4554
4555 if (CHECK_ATTR(BPF_PROG_DETACH))
4556 return -EINVAL;
4557
4558 ptype = attach_type_to_prog_type(attr->attach_type);
4559 if (bpf_mprog_supported(ptype)) {
4560 if (ptype == BPF_PROG_TYPE_UNSPEC)
4561 return -EINVAL;
4562 if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4563 return -EINVAL;
4564 if (attr->attach_bpf_fd) {
4565 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4566 if (IS_ERR(prog))
4567 return PTR_ERR(prog);
4568 }
4569 } else if (is_cgroup_prog_type(ptype, 0, false)) {
4570 if (attr->attach_flags || attr->relative_fd)
4571 return -EINVAL;
4572 } else if (attr->attach_flags ||
4573 attr->relative_fd ||
4574 attr->expected_revision) {
4575 return -EINVAL;
4576 }
4577
4578 switch (ptype) {
4579 case BPF_PROG_TYPE_SK_MSG:
4580 case BPF_PROG_TYPE_SK_SKB:
4581 ret = sock_map_prog_detach(attr, ptype);
4582 break;
4583 case BPF_PROG_TYPE_LIRC_MODE2:
4584 ret = lirc_prog_detach(attr);
4585 break;
4586 case BPF_PROG_TYPE_FLOW_DISSECTOR:
4587 ret = netns_bpf_prog_detach(attr, ptype);
4588 break;
4589 case BPF_PROG_TYPE_CGROUP_DEVICE:
4590 case BPF_PROG_TYPE_CGROUP_SKB:
4591 case BPF_PROG_TYPE_CGROUP_SOCK:
4592 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4593 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4594 case BPF_PROG_TYPE_CGROUP_SYSCTL:
4595 case BPF_PROG_TYPE_SOCK_OPS:
4596 case BPF_PROG_TYPE_LSM:
4597 ret = cgroup_bpf_prog_detach(attr, ptype);
4598 break;
4599 case BPF_PROG_TYPE_SCHED_CLS:
4600 if (attr->attach_type == BPF_TCX_INGRESS ||
4601 attr->attach_type == BPF_TCX_EGRESS)
4602 ret = tcx_prog_detach(attr, prog);
4603 else
4604 ret = netkit_prog_detach(attr, prog);
4605 break;
4606 default:
4607 ret = -EINVAL;
4608 }
4609
4610 if (prog)
4611 bpf_prog_put(prog);
4612 return ret;
4613 }
4614
4615 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4616
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4617 static int bpf_prog_query(const union bpf_attr *attr,
4618 union bpf_attr __user *uattr)
4619 {
4620 if (!bpf_net_capable())
4621 return -EPERM;
4622 if (CHECK_ATTR(BPF_PROG_QUERY))
4623 return -EINVAL;
4624 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4625 return -EINVAL;
4626
4627 switch (attr->query.attach_type) {
4628 case BPF_CGROUP_INET_INGRESS:
4629 case BPF_CGROUP_INET_EGRESS:
4630 case BPF_CGROUP_INET_SOCK_CREATE:
4631 case BPF_CGROUP_INET_SOCK_RELEASE:
4632 case BPF_CGROUP_INET4_BIND:
4633 case BPF_CGROUP_INET6_BIND:
4634 case BPF_CGROUP_INET4_POST_BIND:
4635 case BPF_CGROUP_INET6_POST_BIND:
4636 case BPF_CGROUP_INET4_CONNECT:
4637 case BPF_CGROUP_INET6_CONNECT:
4638 case BPF_CGROUP_UNIX_CONNECT:
4639 case BPF_CGROUP_INET4_GETPEERNAME:
4640 case BPF_CGROUP_INET6_GETPEERNAME:
4641 case BPF_CGROUP_UNIX_GETPEERNAME:
4642 case BPF_CGROUP_INET4_GETSOCKNAME:
4643 case BPF_CGROUP_INET6_GETSOCKNAME:
4644 case BPF_CGROUP_UNIX_GETSOCKNAME:
4645 case BPF_CGROUP_UDP4_SENDMSG:
4646 case BPF_CGROUP_UDP6_SENDMSG:
4647 case BPF_CGROUP_UNIX_SENDMSG:
4648 case BPF_CGROUP_UDP4_RECVMSG:
4649 case BPF_CGROUP_UDP6_RECVMSG:
4650 case BPF_CGROUP_UNIX_RECVMSG:
4651 case BPF_CGROUP_SOCK_OPS:
4652 case BPF_CGROUP_DEVICE:
4653 case BPF_CGROUP_SYSCTL:
4654 case BPF_CGROUP_GETSOCKOPT:
4655 case BPF_CGROUP_SETSOCKOPT:
4656 case BPF_LSM_CGROUP:
4657 return cgroup_bpf_prog_query(attr, uattr);
4658 case BPF_LIRC_MODE2:
4659 return lirc_prog_query(attr, uattr);
4660 case BPF_FLOW_DISSECTOR:
4661 case BPF_SK_LOOKUP:
4662 return netns_bpf_prog_query(attr, uattr);
4663 case BPF_SK_SKB_STREAM_PARSER:
4664 case BPF_SK_SKB_STREAM_VERDICT:
4665 case BPF_SK_MSG_VERDICT:
4666 case BPF_SK_SKB_VERDICT:
4667 return sock_map_bpf_prog_query(attr, uattr);
4668 case BPF_TCX_INGRESS:
4669 case BPF_TCX_EGRESS:
4670 return tcx_prog_query(attr, uattr);
4671 case BPF_NETKIT_PRIMARY:
4672 case BPF_NETKIT_PEER:
4673 return netkit_prog_query(attr, uattr);
4674 default:
4675 return -EINVAL;
4676 }
4677 }
4678
4679 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4680
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4681 static int bpf_prog_test_run(const union bpf_attr *attr,
4682 union bpf_attr __user *uattr)
4683 {
4684 struct bpf_prog *prog;
4685 int ret = -ENOTSUPP;
4686
4687 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4688 return -EINVAL;
4689
4690 if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4691 (!attr->test.ctx_size_in && attr->test.ctx_in))
4692 return -EINVAL;
4693
4694 if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4695 (!attr->test.ctx_size_out && attr->test.ctx_out))
4696 return -EINVAL;
4697
4698 prog = bpf_prog_get(attr->test.prog_fd);
4699 if (IS_ERR(prog))
4700 return PTR_ERR(prog);
4701
4702 if (prog->aux->ops->test_run)
4703 ret = prog->aux->ops->test_run(prog, attr, uattr);
4704
4705 bpf_prog_put(prog);
4706 return ret;
4707 }
4708
4709 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4710
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4711 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4712 union bpf_attr __user *uattr,
4713 struct idr *idr,
4714 spinlock_t *lock)
4715 {
4716 u32 next_id = attr->start_id;
4717 int err = 0;
4718
4719 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4720 return -EINVAL;
4721
4722 if (!capable(CAP_SYS_ADMIN))
4723 return -EPERM;
4724
4725 next_id++;
4726 spin_lock_bh(lock);
4727 if (!idr_get_next(idr, &next_id))
4728 err = -ENOENT;
4729 spin_unlock_bh(lock);
4730
4731 if (!err)
4732 err = put_user(next_id, &uattr->next_id);
4733
4734 return err;
4735 }
4736
bpf_map_get_curr_or_next(u32 * id)4737 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4738 {
4739 struct bpf_map *map;
4740
4741 spin_lock_bh(&map_idr_lock);
4742 again:
4743 map = idr_get_next(&map_idr, id);
4744 if (map) {
4745 map = __bpf_map_inc_not_zero(map, false);
4746 if (IS_ERR(map)) {
4747 (*id)++;
4748 goto again;
4749 }
4750 }
4751 spin_unlock_bh(&map_idr_lock);
4752
4753 return map;
4754 }
4755
bpf_prog_get_curr_or_next(u32 * id)4756 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4757 {
4758 struct bpf_prog *prog;
4759
4760 spin_lock_bh(&prog_idr_lock);
4761 again:
4762 prog = idr_get_next(&prog_idr, id);
4763 if (prog) {
4764 prog = bpf_prog_inc_not_zero(prog);
4765 if (IS_ERR(prog)) {
4766 (*id)++;
4767 goto again;
4768 }
4769 }
4770 spin_unlock_bh(&prog_idr_lock);
4771
4772 return prog;
4773 }
4774
4775 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4776
bpf_prog_by_id(u32 id)4777 struct bpf_prog *bpf_prog_by_id(u32 id)
4778 {
4779 struct bpf_prog *prog;
4780
4781 if (!id)
4782 return ERR_PTR(-ENOENT);
4783
4784 spin_lock_bh(&prog_idr_lock);
4785 prog = idr_find(&prog_idr, id);
4786 if (prog)
4787 prog = bpf_prog_inc_not_zero(prog);
4788 else
4789 prog = ERR_PTR(-ENOENT);
4790 spin_unlock_bh(&prog_idr_lock);
4791 return prog;
4792 }
4793
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4794 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4795 {
4796 struct bpf_prog *prog;
4797 u32 id = attr->prog_id;
4798 int fd;
4799
4800 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4801 return -EINVAL;
4802
4803 if (!capable(CAP_SYS_ADMIN))
4804 return -EPERM;
4805
4806 prog = bpf_prog_by_id(id);
4807 if (IS_ERR(prog))
4808 return PTR_ERR(prog);
4809
4810 fd = bpf_prog_new_fd(prog);
4811 if (fd < 0)
4812 bpf_prog_put(prog);
4813
4814 return fd;
4815 }
4816
4817 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4818
bpf_map_get_fd_by_id(const union bpf_attr * attr)4819 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4820 {
4821 struct bpf_map *map;
4822 u32 id = attr->map_id;
4823 int f_flags;
4824 int fd;
4825
4826 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4827 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4828 return -EINVAL;
4829
4830 if (!capable(CAP_SYS_ADMIN))
4831 return -EPERM;
4832
4833 f_flags = bpf_get_file_flag(attr->open_flags);
4834 if (f_flags < 0)
4835 return f_flags;
4836
4837 spin_lock_bh(&map_idr_lock);
4838 map = idr_find(&map_idr, id);
4839 if (map)
4840 map = __bpf_map_inc_not_zero(map, true);
4841 else
4842 map = ERR_PTR(-ENOENT);
4843 spin_unlock_bh(&map_idr_lock);
4844
4845 if (IS_ERR(map))
4846 return PTR_ERR(map);
4847
4848 fd = bpf_map_new_fd(map, f_flags);
4849 if (fd < 0)
4850 bpf_map_put_with_uref(map);
4851
4852 return fd;
4853 }
4854
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4855 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4856 unsigned long addr, u32 *off,
4857 u32 *type)
4858 {
4859 const struct bpf_map *map;
4860 int i;
4861
4862 mutex_lock(&prog->aux->used_maps_mutex);
4863 for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4864 map = prog->aux->used_maps[i];
4865 if (map == (void *)addr) {
4866 *type = BPF_PSEUDO_MAP_FD;
4867 goto out;
4868 }
4869 if (!map->ops->map_direct_value_meta)
4870 continue;
4871 if (!map->ops->map_direct_value_meta(map, addr, off)) {
4872 *type = BPF_PSEUDO_MAP_VALUE;
4873 goto out;
4874 }
4875 }
4876 map = NULL;
4877
4878 out:
4879 mutex_unlock(&prog->aux->used_maps_mutex);
4880 return map;
4881 }
4882
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4883 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4884 const struct cred *f_cred)
4885 {
4886 const struct bpf_map *map;
4887 struct bpf_insn *insns;
4888 u32 off, type;
4889 u64 imm;
4890 u8 code;
4891 int i;
4892
4893 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4894 GFP_USER);
4895 if (!insns)
4896 return insns;
4897
4898 for (i = 0; i < prog->len; i++) {
4899 code = insns[i].code;
4900
4901 if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4902 insns[i].code = BPF_JMP | BPF_CALL;
4903 insns[i].imm = BPF_FUNC_tail_call;
4904 /* fall-through */
4905 }
4906 if (code == (BPF_JMP | BPF_CALL) ||
4907 code == (BPF_JMP | BPF_CALL_ARGS)) {
4908 if (code == (BPF_JMP | BPF_CALL_ARGS))
4909 insns[i].code = BPF_JMP | BPF_CALL;
4910 if (!bpf_dump_raw_ok(f_cred))
4911 insns[i].imm = 0;
4912 continue;
4913 }
4914 if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4915 insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4916 continue;
4917 }
4918
4919 if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4920 BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4921 insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4922 continue;
4923 }
4924
4925 if (code != (BPF_LD | BPF_IMM | BPF_DW))
4926 continue;
4927
4928 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4929 map = bpf_map_from_imm(prog, imm, &off, &type);
4930 if (map) {
4931 insns[i].src_reg = type;
4932 insns[i].imm = map->id;
4933 insns[i + 1].imm = off;
4934 continue;
4935 }
4936 }
4937
4938 return insns;
4939 }
4940
set_info_rec_size(struct bpf_prog_info * info)4941 static int set_info_rec_size(struct bpf_prog_info *info)
4942 {
4943 /*
4944 * Ensure info.*_rec_size is the same as kernel expected size
4945 *
4946 * or
4947 *
4948 * Only allow zero *_rec_size if both _rec_size and _cnt are
4949 * zero. In this case, the kernel will set the expected
4950 * _rec_size back to the info.
4951 */
4952
4953 if ((info->nr_func_info || info->func_info_rec_size) &&
4954 info->func_info_rec_size != sizeof(struct bpf_func_info))
4955 return -EINVAL;
4956
4957 if ((info->nr_line_info || info->line_info_rec_size) &&
4958 info->line_info_rec_size != sizeof(struct bpf_line_info))
4959 return -EINVAL;
4960
4961 if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4962 info->jited_line_info_rec_size != sizeof(__u64))
4963 return -EINVAL;
4964
4965 info->func_info_rec_size = sizeof(struct bpf_func_info);
4966 info->line_info_rec_size = sizeof(struct bpf_line_info);
4967 info->jited_line_info_rec_size = sizeof(__u64);
4968
4969 return 0;
4970 }
4971
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4972 static int bpf_prog_get_info_by_fd(struct file *file,
4973 struct bpf_prog *prog,
4974 const union bpf_attr *attr,
4975 union bpf_attr __user *uattr)
4976 {
4977 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4978 struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4979 struct bpf_prog_info info;
4980 u32 info_len = attr->info.info_len;
4981 struct bpf_prog_kstats stats;
4982 char __user *uinsns;
4983 u32 ulen;
4984 int err;
4985
4986 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4987 if (err)
4988 return err;
4989 info_len = min_t(u32, sizeof(info), info_len);
4990
4991 memset(&info, 0, sizeof(info));
4992 if (copy_from_user(&info, uinfo, info_len))
4993 return -EFAULT;
4994
4995 info.type = prog->type;
4996 info.id = prog->aux->id;
4997 info.load_time = prog->aux->load_time;
4998 info.created_by_uid = from_kuid_munged(current_user_ns(),
4999 prog->aux->user->uid);
5000 info.gpl_compatible = prog->gpl_compatible;
5001
5002 memcpy(info.tag, prog->tag, sizeof(prog->tag));
5003 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
5004
5005 mutex_lock(&prog->aux->used_maps_mutex);
5006 ulen = info.nr_map_ids;
5007 info.nr_map_ids = prog->aux->used_map_cnt;
5008 ulen = min_t(u32, info.nr_map_ids, ulen);
5009 if (ulen) {
5010 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
5011 u32 i;
5012
5013 for (i = 0; i < ulen; i++)
5014 if (put_user(prog->aux->used_maps[i]->id,
5015 &user_map_ids[i])) {
5016 mutex_unlock(&prog->aux->used_maps_mutex);
5017 return -EFAULT;
5018 }
5019 }
5020 mutex_unlock(&prog->aux->used_maps_mutex);
5021
5022 err = set_info_rec_size(&info);
5023 if (err)
5024 return err;
5025
5026 bpf_prog_get_stats(prog, &stats);
5027 info.run_time_ns = stats.nsecs;
5028 info.run_cnt = stats.cnt;
5029 info.recursion_misses = stats.misses;
5030
5031 info.verified_insns = prog->aux->verified_insns;
5032 if (prog->aux->btf)
5033 info.btf_id = btf_obj_id(prog->aux->btf);
5034
5035 if (!bpf_capable()) {
5036 info.jited_prog_len = 0;
5037 info.xlated_prog_len = 0;
5038 info.nr_jited_ksyms = 0;
5039 info.nr_jited_func_lens = 0;
5040 info.nr_func_info = 0;
5041 info.nr_line_info = 0;
5042 info.nr_jited_line_info = 0;
5043 goto done;
5044 }
5045
5046 ulen = info.xlated_prog_len;
5047 info.xlated_prog_len = bpf_prog_insn_size(prog);
5048 if (info.xlated_prog_len && ulen) {
5049 struct bpf_insn *insns_sanitized;
5050 bool fault;
5051
5052 if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) {
5053 insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
5054 if (!insns_sanitized)
5055 return -ENOMEM;
5056 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
5057 ulen = min_t(u32, info.xlated_prog_len, ulen);
5058 fault = copy_to_user(uinsns, insns_sanitized, ulen);
5059 kfree(insns_sanitized);
5060 if (fault)
5061 return -EFAULT;
5062 } else {
5063 info.xlated_prog_insns = 0;
5064 }
5065 }
5066
5067 if (bpf_prog_is_offloaded(prog->aux)) {
5068 err = bpf_prog_offload_info_fill(&info, prog);
5069 if (err)
5070 return err;
5071 goto done;
5072 }
5073
5074 /* NOTE: the following code is supposed to be skipped for offload.
5075 * bpf_prog_offload_info_fill() is the place to fill similar fields
5076 * for offload.
5077 */
5078 ulen = info.jited_prog_len;
5079 if (prog->aux->func_cnt) {
5080 u32 i;
5081
5082 info.jited_prog_len = 0;
5083 for (i = 0; i < prog->aux->func_cnt; i++)
5084 info.jited_prog_len += prog->aux->func[i]->jited_len;
5085 } else {
5086 info.jited_prog_len = prog->jited_len;
5087 }
5088
5089 if (info.jited_prog_len && ulen) {
5090 if (bpf_dump_raw_ok(file->f_cred)) {
5091 uinsns = u64_to_user_ptr(info.jited_prog_insns);
5092 ulen = min_t(u32, info.jited_prog_len, ulen);
5093
5094 /* for multi-function programs, copy the JITed
5095 * instructions for all the functions
5096 */
5097 if (prog->aux->func_cnt) {
5098 u32 len, free, i;
5099 u8 *img;
5100
5101 free = ulen;
5102 for (i = 0; i < prog->aux->func_cnt; i++) {
5103 len = prog->aux->func[i]->jited_len;
5104 len = min_t(u32, len, free);
5105 img = (u8 *) prog->aux->func[i]->bpf_func;
5106 if (copy_to_user(uinsns, img, len))
5107 return -EFAULT;
5108 uinsns += len;
5109 free -= len;
5110 if (!free)
5111 break;
5112 }
5113 } else {
5114 if (copy_to_user(uinsns, prog->bpf_func, ulen))
5115 return -EFAULT;
5116 }
5117 } else {
5118 info.jited_prog_insns = 0;
5119 }
5120 }
5121
5122 ulen = info.nr_jited_ksyms;
5123 info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
5124 if (ulen) {
5125 if (bpf_dump_raw_ok(file->f_cred)) {
5126 unsigned long ksym_addr;
5127 u64 __user *user_ksyms;
5128 u32 i;
5129
5130 /* copy the address of the kernel symbol
5131 * corresponding to each function
5132 */
5133 ulen = min_t(u32, info.nr_jited_ksyms, ulen);
5134 user_ksyms = u64_to_user_ptr(info.jited_ksyms);
5135 if (prog->aux->func_cnt) {
5136 for (i = 0; i < ulen; i++) {
5137 ksym_addr = (unsigned long)
5138 prog->aux->func[i]->bpf_func;
5139 if (put_user((u64) ksym_addr,
5140 &user_ksyms[i]))
5141 return -EFAULT;
5142 }
5143 } else {
5144 ksym_addr = (unsigned long) prog->bpf_func;
5145 if (put_user((u64) ksym_addr, &user_ksyms[0]))
5146 return -EFAULT;
5147 }
5148 } else {
5149 info.jited_ksyms = 0;
5150 }
5151 }
5152
5153 ulen = info.nr_jited_func_lens;
5154 info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
5155 if (ulen) {
5156 if (bpf_dump_raw_ok(file->f_cred)) {
5157 u32 __user *user_lens;
5158 u32 func_len, i;
5159
5160 /* copy the JITed image lengths for each function */
5161 ulen = min_t(u32, info.nr_jited_func_lens, ulen);
5162 user_lens = u64_to_user_ptr(info.jited_func_lens);
5163 if (prog->aux->func_cnt) {
5164 for (i = 0; i < ulen; i++) {
5165 func_len =
5166 prog->aux->func[i]->jited_len;
5167 if (put_user(func_len, &user_lens[i]))
5168 return -EFAULT;
5169 }
5170 } else {
5171 func_len = prog->jited_len;
5172 if (put_user(func_len, &user_lens[0]))
5173 return -EFAULT;
5174 }
5175 } else {
5176 info.jited_func_lens = 0;
5177 }
5178 }
5179
5180 info.attach_btf_id = prog->aux->attach_btf_id;
5181 if (attach_btf)
5182 info.attach_btf_obj_id = btf_obj_id(attach_btf);
5183
5184 ulen = info.nr_func_info;
5185 info.nr_func_info = prog->aux->func_info_cnt;
5186 if (info.nr_func_info && ulen) {
5187 char __user *user_finfo;
5188
5189 user_finfo = u64_to_user_ptr(info.func_info);
5190 ulen = min_t(u32, info.nr_func_info, ulen);
5191 if (copy_to_user(user_finfo, prog->aux->func_info,
5192 info.func_info_rec_size * ulen))
5193 return -EFAULT;
5194 }
5195
5196 ulen = info.nr_line_info;
5197 info.nr_line_info = prog->aux->nr_linfo;
5198 if (info.nr_line_info && ulen) {
5199 __u8 __user *user_linfo;
5200
5201 user_linfo = u64_to_user_ptr(info.line_info);
5202 ulen = min_t(u32, info.nr_line_info, ulen);
5203 if (copy_to_user(user_linfo, prog->aux->linfo,
5204 info.line_info_rec_size * ulen))
5205 return -EFAULT;
5206 }
5207
5208 ulen = info.nr_jited_line_info;
5209 if (prog->aux->jited_linfo)
5210 info.nr_jited_line_info = prog->aux->nr_linfo;
5211 else
5212 info.nr_jited_line_info = 0;
5213 if (info.nr_jited_line_info && ulen) {
5214 if (bpf_dump_raw_ok(file->f_cred)) {
5215 unsigned long line_addr;
5216 __u64 __user *user_linfo;
5217 u32 i;
5218
5219 user_linfo = u64_to_user_ptr(info.jited_line_info);
5220 ulen = min_t(u32, info.nr_jited_line_info, ulen);
5221 for (i = 0; i < ulen; i++) {
5222 line_addr = (unsigned long)prog->aux->jited_linfo[i];
5223 if (put_user((__u64)line_addr, &user_linfo[i]))
5224 return -EFAULT;
5225 }
5226 } else {
5227 info.jited_line_info = 0;
5228 }
5229 }
5230
5231 ulen = info.nr_prog_tags;
5232 info.nr_prog_tags = prog->aux->func_cnt ? : 1;
5233 if (ulen) {
5234 __u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
5235 u32 i;
5236
5237 user_prog_tags = u64_to_user_ptr(info.prog_tags);
5238 ulen = min_t(u32, info.nr_prog_tags, ulen);
5239 if (prog->aux->func_cnt) {
5240 for (i = 0; i < ulen; i++) {
5241 if (copy_to_user(user_prog_tags[i],
5242 prog->aux->func[i]->tag,
5243 BPF_TAG_SIZE))
5244 return -EFAULT;
5245 }
5246 } else {
5247 if (copy_to_user(user_prog_tags[0],
5248 prog->tag, BPF_TAG_SIZE))
5249 return -EFAULT;
5250 }
5251 }
5252
5253 done:
5254 if (copy_to_user(uinfo, &info, info_len) ||
5255 put_user(info_len, &uattr->info.info_len))
5256 return -EFAULT;
5257
5258 return 0;
5259 }
5260
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)5261 static int bpf_map_get_info_by_fd(struct file *file,
5262 struct bpf_map *map,
5263 const union bpf_attr *attr,
5264 union bpf_attr __user *uattr)
5265 {
5266 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5267 struct bpf_map_info info;
5268 u32 info_len = attr->info.info_len;
5269 int err;
5270
5271 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5272 if (err)
5273 return err;
5274 info_len = min_t(u32, sizeof(info), info_len);
5275
5276 memset(&info, 0, sizeof(info));
5277 if (copy_from_user(&info, uinfo, info_len))
5278 return -EFAULT;
5279
5280 info.type = map->map_type;
5281 info.id = map->id;
5282 info.key_size = map->key_size;
5283 info.value_size = map->value_size;
5284 info.max_entries = map->max_entries;
5285 info.map_flags = map->map_flags;
5286 info.map_extra = map->map_extra;
5287 memcpy(info.name, map->name, sizeof(map->name));
5288
5289 if (map->btf) {
5290 info.btf_id = btf_obj_id(map->btf);
5291 info.btf_key_type_id = map->btf_key_type_id;
5292 info.btf_value_type_id = map->btf_value_type_id;
5293 }
5294 info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5295 if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5296 bpf_map_struct_ops_info_fill(&info, map);
5297
5298 if (bpf_map_is_offloaded(map)) {
5299 err = bpf_map_offload_info_fill(&info, map);
5300 if (err)
5301 return err;
5302 }
5303
5304 if (info.hash) {
5305 char __user *uhash = u64_to_user_ptr(info.hash);
5306
5307 if (!map->ops->map_get_hash)
5308 return -EINVAL;
5309
5310 if (info.hash_size != SHA256_DIGEST_SIZE)
5311 return -EINVAL;
5312
5313 err = map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, map->sha);
5314 if (err != 0)
5315 return err;
5316
5317 if (copy_to_user(uhash, map->sha, SHA256_DIGEST_SIZE) != 0)
5318 return -EFAULT;
5319 } else if (info.hash_size) {
5320 return -EINVAL;
5321 }
5322
5323 if (copy_to_user(uinfo, &info, info_len) ||
5324 put_user(info_len, &uattr->info.info_len))
5325 return -EFAULT;
5326
5327 return 0;
5328 }
5329
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5330 static int bpf_btf_get_info_by_fd(struct file *file,
5331 struct btf *btf,
5332 const union bpf_attr *attr,
5333 union bpf_attr __user *uattr)
5334 {
5335 struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5336 u32 info_len = attr->info.info_len;
5337 int err;
5338
5339 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5340 if (err)
5341 return err;
5342
5343 return btf_get_info_by_fd(btf, attr, uattr);
5344 }
5345
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5346 static int bpf_link_get_info_by_fd(struct file *file,
5347 struct bpf_link *link,
5348 const union bpf_attr *attr,
5349 union bpf_attr __user *uattr)
5350 {
5351 struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5352 struct bpf_link_info info;
5353 u32 info_len = attr->info.info_len;
5354 int err;
5355
5356 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5357 if (err)
5358 return err;
5359 info_len = min_t(u32, sizeof(info), info_len);
5360
5361 memset(&info, 0, sizeof(info));
5362 if (copy_from_user(&info, uinfo, info_len))
5363 return -EFAULT;
5364
5365 info.type = link->type;
5366 info.id = link->id;
5367 if (link->prog)
5368 info.prog_id = link->prog->aux->id;
5369
5370 if (link->ops->fill_link_info) {
5371 err = link->ops->fill_link_info(link, &info);
5372 if (err)
5373 return err;
5374 }
5375
5376 if (copy_to_user(uinfo, &info, info_len) ||
5377 put_user(info_len, &uattr->info.info_len))
5378 return -EFAULT;
5379
5380 return 0;
5381 }
5382
5383
token_get_info_by_fd(struct file * file,struct bpf_token * token,const union bpf_attr * attr,union bpf_attr __user * uattr)5384 static int token_get_info_by_fd(struct file *file,
5385 struct bpf_token *token,
5386 const union bpf_attr *attr,
5387 union bpf_attr __user *uattr)
5388 {
5389 struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5390 u32 info_len = attr->info.info_len;
5391 int err;
5392
5393 err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5394 if (err)
5395 return err;
5396 return bpf_token_get_info_by_fd(token, attr, uattr);
5397 }
5398
5399 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5400
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5401 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5402 union bpf_attr __user *uattr)
5403 {
5404 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5405 return -EINVAL;
5406
5407 CLASS(fd, f)(attr->info.bpf_fd);
5408 if (fd_empty(f))
5409 return -EBADFD;
5410
5411 if (fd_file(f)->f_op == &bpf_prog_fops)
5412 return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5413 uattr);
5414 else if (fd_file(f)->f_op == &bpf_map_fops)
5415 return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5416 uattr);
5417 else if (fd_file(f)->f_op == &btf_fops)
5418 return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5419 else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5420 return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5421 attr, uattr);
5422 else if (fd_file(f)->f_op == &bpf_token_fops)
5423 return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5424 attr, uattr);
5425 return -EINVAL;
5426 }
5427
5428 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5429
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5430 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5431 {
5432 struct bpf_token *token = NULL;
5433
5434 if (CHECK_ATTR(BPF_BTF_LOAD))
5435 return -EINVAL;
5436
5437 if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5438 return -EINVAL;
5439
5440 if (attr->btf_flags & BPF_F_TOKEN_FD) {
5441 token = bpf_token_get_from_fd(attr->btf_token_fd);
5442 if (IS_ERR(token))
5443 return PTR_ERR(token);
5444 if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5445 bpf_token_put(token);
5446 token = NULL;
5447 }
5448 }
5449
5450 if (!bpf_token_capable(token, CAP_BPF)) {
5451 bpf_token_put(token);
5452 return -EPERM;
5453 }
5454
5455 bpf_token_put(token);
5456
5457 return btf_new_fd(attr, uattr, uattr_size);
5458 }
5459
5460 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5461
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5462 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5463 {
5464 struct bpf_token *token = NULL;
5465
5466 if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5467 return -EINVAL;
5468
5469 if (attr->open_flags & ~BPF_F_TOKEN_FD)
5470 return -EINVAL;
5471
5472 if (attr->open_flags & BPF_F_TOKEN_FD) {
5473 token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5474 if (IS_ERR(token))
5475 return PTR_ERR(token);
5476 if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5477 bpf_token_put(token);
5478 token = NULL;
5479 }
5480 }
5481
5482 if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5483 bpf_token_put(token);
5484 return -EPERM;
5485 }
5486
5487 bpf_token_put(token);
5488
5489 return btf_get_fd_by_id(attr->btf_id);
5490 }
5491
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)5492 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5493 union bpf_attr __user *uattr,
5494 u32 prog_id, u32 fd_type,
5495 const char *buf, u64 probe_offset,
5496 u64 probe_addr)
5497 {
5498 char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5499 u32 len = buf ? strlen(buf) : 0, input_len;
5500 int err = 0;
5501
5502 if (put_user(len, &uattr->task_fd_query.buf_len))
5503 return -EFAULT;
5504 input_len = attr->task_fd_query.buf_len;
5505 if (input_len && ubuf) {
5506 if (!len) {
5507 /* nothing to copy, just make ubuf NULL terminated */
5508 char zero = '\0';
5509
5510 if (put_user(zero, ubuf))
5511 return -EFAULT;
5512 } else {
5513 err = bpf_copy_to_user(ubuf, buf, input_len, len);
5514 if (err == -EFAULT)
5515 return err;
5516 }
5517 }
5518
5519 if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5520 put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5521 put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5522 put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5523 return -EFAULT;
5524
5525 return err;
5526 }
5527
5528 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5529
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5530 static int bpf_task_fd_query(const union bpf_attr *attr,
5531 union bpf_attr __user *uattr)
5532 {
5533 pid_t pid = attr->task_fd_query.pid;
5534 u32 fd = attr->task_fd_query.fd;
5535 const struct perf_event *event;
5536 struct task_struct *task;
5537 struct file *file;
5538 int err;
5539
5540 if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5541 return -EINVAL;
5542
5543 if (!capable(CAP_SYS_ADMIN))
5544 return -EPERM;
5545
5546 if (attr->task_fd_query.flags != 0)
5547 return -EINVAL;
5548
5549 rcu_read_lock();
5550 task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5551 rcu_read_unlock();
5552 if (!task)
5553 return -ENOENT;
5554
5555 err = 0;
5556 file = fget_task(task, fd);
5557 put_task_struct(task);
5558 if (!file)
5559 return -EBADF;
5560
5561 if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5562 struct bpf_link *link = file->private_data;
5563
5564 if (link->ops == &bpf_raw_tp_link_lops) {
5565 struct bpf_raw_tp_link *raw_tp =
5566 container_of(link, struct bpf_raw_tp_link, link);
5567 struct bpf_raw_event_map *btp = raw_tp->btp;
5568
5569 err = bpf_task_fd_query_copy(attr, uattr,
5570 raw_tp->link.prog->aux->id,
5571 BPF_FD_TYPE_RAW_TRACEPOINT,
5572 btp->tp->name, 0, 0);
5573 goto put_file;
5574 }
5575 goto out_not_supp;
5576 }
5577
5578 event = perf_get_event(file);
5579 if (!IS_ERR(event)) {
5580 u64 probe_offset, probe_addr;
5581 u32 prog_id, fd_type;
5582 const char *buf;
5583
5584 err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5585 &buf, &probe_offset,
5586 &probe_addr, NULL);
5587 if (!err)
5588 err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5589 fd_type, buf,
5590 probe_offset,
5591 probe_addr);
5592 goto put_file;
5593 }
5594
5595 out_not_supp:
5596 err = -ENOTSUPP;
5597 put_file:
5598 fput(file);
5599 return err;
5600 }
5601
5602 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5603
5604 #define BPF_DO_BATCH(fn, ...) \
5605 do { \
5606 if (!fn) { \
5607 err = -ENOTSUPP; \
5608 goto err_put; \
5609 } \
5610 err = fn(__VA_ARGS__); \
5611 } while (0)
5612
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5613 static int bpf_map_do_batch(const union bpf_attr *attr,
5614 union bpf_attr __user *uattr,
5615 int cmd)
5616 {
5617 bool has_read = cmd == BPF_MAP_LOOKUP_BATCH ||
5618 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5619 bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5620 struct bpf_map *map;
5621 int err;
5622
5623 if (CHECK_ATTR(BPF_MAP_BATCH))
5624 return -EINVAL;
5625
5626 CLASS(fd, f)(attr->batch.map_fd);
5627
5628 map = __bpf_map_get(f);
5629 if (IS_ERR(map))
5630 return PTR_ERR(map);
5631 if (has_write)
5632 bpf_map_write_active_inc(map);
5633 if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5634 err = -EPERM;
5635 goto err_put;
5636 }
5637 if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5638 err = -EPERM;
5639 goto err_put;
5640 }
5641
5642 if (cmd == BPF_MAP_LOOKUP_BATCH)
5643 BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5644 else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5645 BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5646 else if (cmd == BPF_MAP_UPDATE_BATCH)
5647 BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5648 else
5649 BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5650 err_put:
5651 if (has_write) {
5652 maybe_wait_bpf_programs(map);
5653 bpf_map_write_active_dec(map);
5654 }
5655 return err;
5656 }
5657
5658 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5659 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5660 {
5661 struct bpf_prog *prog;
5662 int ret;
5663
5664 if (CHECK_ATTR(BPF_LINK_CREATE))
5665 return -EINVAL;
5666
5667 if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5668 return bpf_struct_ops_link_create(attr);
5669
5670 prog = bpf_prog_get(attr->link_create.prog_fd);
5671 if (IS_ERR(prog))
5672 return PTR_ERR(prog);
5673
5674 ret = bpf_prog_attach_check_attach_type(prog,
5675 attr->link_create.attach_type);
5676 if (ret)
5677 goto out;
5678
5679 switch (prog->type) {
5680 case BPF_PROG_TYPE_CGROUP_SKB:
5681 case BPF_PROG_TYPE_CGROUP_SOCK:
5682 case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5683 case BPF_PROG_TYPE_SOCK_OPS:
5684 case BPF_PROG_TYPE_CGROUP_DEVICE:
5685 case BPF_PROG_TYPE_CGROUP_SYSCTL:
5686 case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5687 ret = cgroup_bpf_link_attach(attr, prog);
5688 break;
5689 case BPF_PROG_TYPE_EXT:
5690 ret = bpf_tracing_prog_attach(prog,
5691 attr->link_create.target_fd,
5692 attr->link_create.target_btf_id,
5693 attr->link_create.tracing.cookie,
5694 attr->link_create.attach_type);
5695 break;
5696 case BPF_PROG_TYPE_LSM:
5697 case BPF_PROG_TYPE_TRACING:
5698 if (attr->link_create.attach_type != prog->expected_attach_type) {
5699 ret = -EINVAL;
5700 goto out;
5701 }
5702 if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5703 ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie,
5704 attr->link_create.attach_type);
5705 else if (prog->expected_attach_type == BPF_TRACE_ITER)
5706 ret = bpf_iter_link_attach(attr, uattr, prog);
5707 else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5708 ret = cgroup_bpf_link_attach(attr, prog);
5709 else
5710 ret = bpf_tracing_prog_attach(prog,
5711 attr->link_create.target_fd,
5712 attr->link_create.target_btf_id,
5713 attr->link_create.tracing.cookie,
5714 attr->link_create.attach_type);
5715 break;
5716 case BPF_PROG_TYPE_FLOW_DISSECTOR:
5717 case BPF_PROG_TYPE_SK_LOOKUP:
5718 ret = netns_bpf_link_create(attr, prog);
5719 break;
5720 case BPF_PROG_TYPE_SK_MSG:
5721 case BPF_PROG_TYPE_SK_SKB:
5722 ret = sock_map_link_create(attr, prog);
5723 break;
5724 #ifdef CONFIG_NET
5725 case BPF_PROG_TYPE_XDP:
5726 ret = bpf_xdp_link_attach(attr, prog);
5727 break;
5728 case BPF_PROG_TYPE_SCHED_CLS:
5729 if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5730 attr->link_create.attach_type == BPF_TCX_EGRESS)
5731 ret = tcx_link_attach(attr, prog);
5732 else
5733 ret = netkit_link_attach(attr, prog);
5734 break;
5735 case BPF_PROG_TYPE_NETFILTER:
5736 ret = bpf_nf_link_attach(attr, prog);
5737 break;
5738 #endif
5739 case BPF_PROG_TYPE_PERF_EVENT:
5740 case BPF_PROG_TYPE_TRACEPOINT:
5741 ret = bpf_perf_link_attach(attr, prog);
5742 break;
5743 case BPF_PROG_TYPE_KPROBE:
5744 if (attr->link_create.attach_type == BPF_PERF_EVENT)
5745 ret = bpf_perf_link_attach(attr, prog);
5746 else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5747 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5748 ret = bpf_kprobe_multi_link_attach(attr, prog);
5749 else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5750 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5751 ret = bpf_uprobe_multi_link_attach(attr, prog);
5752 break;
5753 default:
5754 ret = -EINVAL;
5755 }
5756
5757 out:
5758 if (ret < 0)
5759 bpf_prog_put(prog);
5760 return ret;
5761 }
5762
link_update_map(struct bpf_link * link,union bpf_attr * attr)5763 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5764 {
5765 struct bpf_map *new_map, *old_map = NULL;
5766 int ret;
5767
5768 new_map = bpf_map_get(attr->link_update.new_map_fd);
5769 if (IS_ERR(new_map))
5770 return PTR_ERR(new_map);
5771
5772 if (attr->link_update.flags & BPF_F_REPLACE) {
5773 old_map = bpf_map_get(attr->link_update.old_map_fd);
5774 if (IS_ERR(old_map)) {
5775 ret = PTR_ERR(old_map);
5776 goto out_put;
5777 }
5778 } else if (attr->link_update.old_map_fd) {
5779 ret = -EINVAL;
5780 goto out_put;
5781 }
5782
5783 ret = link->ops->update_map(link, new_map, old_map);
5784
5785 if (old_map)
5786 bpf_map_put(old_map);
5787 out_put:
5788 bpf_map_put(new_map);
5789 return ret;
5790 }
5791
5792 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5793
link_update(union bpf_attr * attr)5794 static int link_update(union bpf_attr *attr)
5795 {
5796 struct bpf_prog *old_prog = NULL, *new_prog;
5797 struct bpf_link *link;
5798 u32 flags;
5799 int ret;
5800
5801 if (CHECK_ATTR(BPF_LINK_UPDATE))
5802 return -EINVAL;
5803
5804 flags = attr->link_update.flags;
5805 if (flags & ~BPF_F_REPLACE)
5806 return -EINVAL;
5807
5808 link = bpf_link_get_from_fd(attr->link_update.link_fd);
5809 if (IS_ERR(link))
5810 return PTR_ERR(link);
5811
5812 if (link->ops->update_map) {
5813 ret = link_update_map(link, attr);
5814 goto out_put_link;
5815 }
5816
5817 new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5818 if (IS_ERR(new_prog)) {
5819 ret = PTR_ERR(new_prog);
5820 goto out_put_link;
5821 }
5822
5823 if (flags & BPF_F_REPLACE) {
5824 old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5825 if (IS_ERR(old_prog)) {
5826 ret = PTR_ERR(old_prog);
5827 old_prog = NULL;
5828 goto out_put_progs;
5829 }
5830 } else if (attr->link_update.old_prog_fd) {
5831 ret = -EINVAL;
5832 goto out_put_progs;
5833 }
5834
5835 if (link->ops->update_prog)
5836 ret = link->ops->update_prog(link, new_prog, old_prog);
5837 else
5838 ret = -EINVAL;
5839
5840 out_put_progs:
5841 if (old_prog)
5842 bpf_prog_put(old_prog);
5843 if (ret)
5844 bpf_prog_put(new_prog);
5845 out_put_link:
5846 bpf_link_put_direct(link);
5847 return ret;
5848 }
5849
5850 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5851
link_detach(union bpf_attr * attr)5852 static int link_detach(union bpf_attr *attr)
5853 {
5854 struct bpf_link *link;
5855 int ret;
5856
5857 if (CHECK_ATTR(BPF_LINK_DETACH))
5858 return -EINVAL;
5859
5860 link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5861 if (IS_ERR(link))
5862 return PTR_ERR(link);
5863
5864 if (link->ops->detach)
5865 ret = link->ops->detach(link);
5866 else
5867 ret = -EOPNOTSUPP;
5868
5869 bpf_link_put_direct(link);
5870 return ret;
5871 }
5872
bpf_link_inc_not_zero(struct bpf_link * link)5873 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5874 {
5875 return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5876 }
5877 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5878
bpf_link_by_id(u32 id)5879 struct bpf_link *bpf_link_by_id(u32 id)
5880 {
5881 struct bpf_link *link;
5882
5883 if (!id)
5884 return ERR_PTR(-ENOENT);
5885
5886 spin_lock_bh(&link_idr_lock);
5887 /* before link is "settled", ID is 0, pretend it doesn't exist yet */
5888 link = idr_find(&link_idr, id);
5889 if (link) {
5890 if (link->id)
5891 link = bpf_link_inc_not_zero(link);
5892 else
5893 link = ERR_PTR(-EAGAIN);
5894 } else {
5895 link = ERR_PTR(-ENOENT);
5896 }
5897 spin_unlock_bh(&link_idr_lock);
5898 return link;
5899 }
5900
bpf_link_get_curr_or_next(u32 * id)5901 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5902 {
5903 struct bpf_link *link;
5904
5905 spin_lock_bh(&link_idr_lock);
5906 again:
5907 link = idr_get_next(&link_idr, id);
5908 if (link) {
5909 link = bpf_link_inc_not_zero(link);
5910 if (IS_ERR(link)) {
5911 (*id)++;
5912 goto again;
5913 }
5914 }
5915 spin_unlock_bh(&link_idr_lock);
5916
5917 return link;
5918 }
5919
5920 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5921
bpf_link_get_fd_by_id(const union bpf_attr * attr)5922 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5923 {
5924 struct bpf_link *link;
5925 u32 id = attr->link_id;
5926 int fd;
5927
5928 if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5929 return -EINVAL;
5930
5931 if (!capable(CAP_SYS_ADMIN))
5932 return -EPERM;
5933
5934 link = bpf_link_by_id(id);
5935 if (IS_ERR(link))
5936 return PTR_ERR(link);
5937
5938 fd = bpf_link_new_fd(link);
5939 if (fd < 0)
5940 bpf_link_put_direct(link);
5941
5942 return fd;
5943 }
5944
5945 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5946
bpf_stats_release(struct inode * inode,struct file * file)5947 static int bpf_stats_release(struct inode *inode, struct file *file)
5948 {
5949 mutex_lock(&bpf_stats_enabled_mutex);
5950 static_key_slow_dec(&bpf_stats_enabled_key.key);
5951 mutex_unlock(&bpf_stats_enabled_mutex);
5952 return 0;
5953 }
5954
5955 static const struct file_operations bpf_stats_fops = {
5956 .release = bpf_stats_release,
5957 };
5958
bpf_enable_runtime_stats(void)5959 static int bpf_enable_runtime_stats(void)
5960 {
5961 int fd;
5962
5963 mutex_lock(&bpf_stats_enabled_mutex);
5964
5965 /* Set a very high limit to avoid overflow */
5966 if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5967 mutex_unlock(&bpf_stats_enabled_mutex);
5968 return -EBUSY;
5969 }
5970
5971 fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5972 if (fd >= 0)
5973 static_key_slow_inc(&bpf_stats_enabled_key.key);
5974
5975 mutex_unlock(&bpf_stats_enabled_mutex);
5976 return fd;
5977 }
5978
5979 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5980
bpf_enable_stats(union bpf_attr * attr)5981 static int bpf_enable_stats(union bpf_attr *attr)
5982 {
5983
5984 if (CHECK_ATTR(BPF_ENABLE_STATS))
5985 return -EINVAL;
5986
5987 if (!capable(CAP_SYS_ADMIN))
5988 return -EPERM;
5989
5990 switch (attr->enable_stats.type) {
5991 case BPF_STATS_RUN_TIME:
5992 return bpf_enable_runtime_stats();
5993 default:
5994 break;
5995 }
5996 return -EINVAL;
5997 }
5998
5999 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
6000
bpf_iter_create(union bpf_attr * attr)6001 static int bpf_iter_create(union bpf_attr *attr)
6002 {
6003 struct bpf_link *link;
6004 int err;
6005
6006 if (CHECK_ATTR(BPF_ITER_CREATE))
6007 return -EINVAL;
6008
6009 if (attr->iter_create.flags)
6010 return -EINVAL;
6011
6012 link = bpf_link_get_from_fd(attr->iter_create.link_fd);
6013 if (IS_ERR(link))
6014 return PTR_ERR(link);
6015
6016 err = bpf_iter_new_fd(link);
6017 bpf_link_put_direct(link);
6018
6019 return err;
6020 }
6021
6022 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
6023
bpf_prog_bind_map(union bpf_attr * attr)6024 static int bpf_prog_bind_map(union bpf_attr *attr)
6025 {
6026 struct bpf_prog *prog;
6027 struct bpf_map *map;
6028 struct bpf_map **used_maps_old, **used_maps_new;
6029 int i, ret = 0;
6030
6031 if (CHECK_ATTR(BPF_PROG_BIND_MAP))
6032 return -EINVAL;
6033
6034 if (attr->prog_bind_map.flags)
6035 return -EINVAL;
6036
6037 prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
6038 if (IS_ERR(prog))
6039 return PTR_ERR(prog);
6040
6041 map = bpf_map_get(attr->prog_bind_map.map_fd);
6042 if (IS_ERR(map)) {
6043 ret = PTR_ERR(map);
6044 goto out_prog_put;
6045 }
6046
6047 mutex_lock(&prog->aux->used_maps_mutex);
6048
6049 used_maps_old = prog->aux->used_maps;
6050
6051 for (i = 0; i < prog->aux->used_map_cnt; i++)
6052 if (used_maps_old[i] == map) {
6053 bpf_map_put(map);
6054 goto out_unlock;
6055 }
6056
6057 used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
6058 sizeof(used_maps_new[0]),
6059 GFP_KERNEL);
6060 if (!used_maps_new) {
6061 ret = -ENOMEM;
6062 goto out_unlock;
6063 }
6064
6065 /* The bpf program will not access the bpf map, but for the sake of
6066 * simplicity, increase sleepable_refcnt for sleepable program as well.
6067 */
6068 if (prog->sleepable)
6069 atomic64_inc(&map->sleepable_refcnt);
6070 memcpy(used_maps_new, used_maps_old,
6071 sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
6072 used_maps_new[prog->aux->used_map_cnt] = map;
6073
6074 prog->aux->used_map_cnt++;
6075 prog->aux->used_maps = used_maps_new;
6076
6077 kfree(used_maps_old);
6078
6079 out_unlock:
6080 mutex_unlock(&prog->aux->used_maps_mutex);
6081
6082 if (ret)
6083 bpf_map_put(map);
6084 out_prog_put:
6085 bpf_prog_put(prog);
6086 return ret;
6087 }
6088
6089 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
6090
token_create(union bpf_attr * attr)6091 static int token_create(union bpf_attr *attr)
6092 {
6093 if (CHECK_ATTR(BPF_TOKEN_CREATE))
6094 return -EINVAL;
6095
6096 /* no flags are supported yet */
6097 if (attr->token_create.flags)
6098 return -EINVAL;
6099
6100 return bpf_token_create(attr);
6101 }
6102
6103 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd
6104
prog_stream_read(union bpf_attr * attr)6105 static int prog_stream_read(union bpf_attr *attr)
6106 {
6107 char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf);
6108 u32 len = attr->prog_stream_read.stream_buf_len;
6109 struct bpf_prog *prog;
6110 int ret;
6111
6112 if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD))
6113 return -EINVAL;
6114
6115 prog = bpf_prog_get(attr->prog_stream_read.prog_fd);
6116 if (IS_ERR(prog))
6117 return PTR_ERR(prog);
6118
6119 ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len);
6120 bpf_prog_put(prog);
6121
6122 return ret;
6123 }
6124
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)6125 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
6126 {
6127 union bpf_attr attr;
6128 int err;
6129
6130 err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
6131 if (err)
6132 return err;
6133 size = min_t(u32, size, sizeof(attr));
6134
6135 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
6136 memset(&attr, 0, sizeof(attr));
6137 if (copy_from_bpfptr(&attr, uattr, size) != 0)
6138 return -EFAULT;
6139
6140 err = security_bpf(cmd, &attr, size, uattr.is_kernel);
6141 if (err < 0)
6142 return err;
6143
6144 switch (cmd) {
6145 case BPF_MAP_CREATE:
6146 err = map_create(&attr, uattr);
6147 break;
6148 case BPF_MAP_LOOKUP_ELEM:
6149 err = map_lookup_elem(&attr);
6150 break;
6151 case BPF_MAP_UPDATE_ELEM:
6152 err = map_update_elem(&attr, uattr);
6153 break;
6154 case BPF_MAP_DELETE_ELEM:
6155 err = map_delete_elem(&attr, uattr);
6156 break;
6157 case BPF_MAP_GET_NEXT_KEY:
6158 err = map_get_next_key(&attr);
6159 break;
6160 case BPF_MAP_FREEZE:
6161 err = map_freeze(&attr);
6162 break;
6163 case BPF_PROG_LOAD:
6164 err = bpf_prog_load(&attr, uattr, size);
6165 break;
6166 case BPF_OBJ_PIN:
6167 err = bpf_obj_pin(&attr);
6168 break;
6169 case BPF_OBJ_GET:
6170 err = bpf_obj_get(&attr);
6171 break;
6172 case BPF_PROG_ATTACH:
6173 err = bpf_prog_attach(&attr);
6174 break;
6175 case BPF_PROG_DETACH:
6176 err = bpf_prog_detach(&attr);
6177 break;
6178 case BPF_PROG_QUERY:
6179 err = bpf_prog_query(&attr, uattr.user);
6180 break;
6181 case BPF_PROG_TEST_RUN:
6182 err = bpf_prog_test_run(&attr, uattr.user);
6183 break;
6184 case BPF_PROG_GET_NEXT_ID:
6185 err = bpf_obj_get_next_id(&attr, uattr.user,
6186 &prog_idr, &prog_idr_lock);
6187 break;
6188 case BPF_MAP_GET_NEXT_ID:
6189 err = bpf_obj_get_next_id(&attr, uattr.user,
6190 &map_idr, &map_idr_lock);
6191 break;
6192 case BPF_BTF_GET_NEXT_ID:
6193 err = bpf_obj_get_next_id(&attr, uattr.user,
6194 &btf_idr, &btf_idr_lock);
6195 break;
6196 case BPF_PROG_GET_FD_BY_ID:
6197 err = bpf_prog_get_fd_by_id(&attr);
6198 break;
6199 case BPF_MAP_GET_FD_BY_ID:
6200 err = bpf_map_get_fd_by_id(&attr);
6201 break;
6202 case BPF_OBJ_GET_INFO_BY_FD:
6203 err = bpf_obj_get_info_by_fd(&attr, uattr.user);
6204 break;
6205 case BPF_RAW_TRACEPOINT_OPEN:
6206 err = bpf_raw_tracepoint_open(&attr);
6207 break;
6208 case BPF_BTF_LOAD:
6209 err = bpf_btf_load(&attr, uattr, size);
6210 break;
6211 case BPF_BTF_GET_FD_BY_ID:
6212 err = bpf_btf_get_fd_by_id(&attr);
6213 break;
6214 case BPF_TASK_FD_QUERY:
6215 err = bpf_task_fd_query(&attr, uattr.user);
6216 break;
6217 case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
6218 err = map_lookup_and_delete_elem(&attr);
6219 break;
6220 case BPF_MAP_LOOKUP_BATCH:
6221 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
6222 break;
6223 case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
6224 err = bpf_map_do_batch(&attr, uattr.user,
6225 BPF_MAP_LOOKUP_AND_DELETE_BATCH);
6226 break;
6227 case BPF_MAP_UPDATE_BATCH:
6228 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
6229 break;
6230 case BPF_MAP_DELETE_BATCH:
6231 err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
6232 break;
6233 case BPF_LINK_CREATE:
6234 err = link_create(&attr, uattr);
6235 break;
6236 case BPF_LINK_UPDATE:
6237 err = link_update(&attr);
6238 break;
6239 case BPF_LINK_GET_FD_BY_ID:
6240 err = bpf_link_get_fd_by_id(&attr);
6241 break;
6242 case BPF_LINK_GET_NEXT_ID:
6243 err = bpf_obj_get_next_id(&attr, uattr.user,
6244 &link_idr, &link_idr_lock);
6245 break;
6246 case BPF_ENABLE_STATS:
6247 err = bpf_enable_stats(&attr);
6248 break;
6249 case BPF_ITER_CREATE:
6250 err = bpf_iter_create(&attr);
6251 break;
6252 case BPF_LINK_DETACH:
6253 err = link_detach(&attr);
6254 break;
6255 case BPF_PROG_BIND_MAP:
6256 err = bpf_prog_bind_map(&attr);
6257 break;
6258 case BPF_TOKEN_CREATE:
6259 err = token_create(&attr);
6260 break;
6261 case BPF_PROG_STREAM_READ_BY_FD:
6262 err = prog_stream_read(&attr);
6263 break;
6264 default:
6265 err = -EINVAL;
6266 break;
6267 }
6268
6269 return err;
6270 }
6271
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)6272 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
6273 {
6274 return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
6275 }
6276
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)6277 static bool syscall_prog_is_valid_access(int off, int size,
6278 enum bpf_access_type type,
6279 const struct bpf_prog *prog,
6280 struct bpf_insn_access_aux *info)
6281 {
6282 if (off < 0 || off >= U16_MAX)
6283 return false;
6284 if (off % size != 0)
6285 return false;
6286 return true;
6287 }
6288
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)6289 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
6290 {
6291 switch (cmd) {
6292 case BPF_MAP_CREATE:
6293 case BPF_MAP_DELETE_ELEM:
6294 case BPF_MAP_UPDATE_ELEM:
6295 case BPF_MAP_FREEZE:
6296 case BPF_MAP_GET_FD_BY_ID:
6297 case BPF_PROG_LOAD:
6298 case BPF_BTF_LOAD:
6299 case BPF_LINK_CREATE:
6300 case BPF_RAW_TRACEPOINT_OPEN:
6301 break;
6302 default:
6303 return -EINVAL;
6304 }
6305 return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
6306 }
6307
6308
6309 /* To shut up -Wmissing-prototypes.
6310 * This function is used by the kernel light skeleton
6311 * to load bpf programs when modules are loaded or during kernel boot.
6312 * See tools/lib/bpf/skel_internal.h
6313 */
6314 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
6315
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)6316 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
6317 {
6318 struct bpf_prog * __maybe_unused prog;
6319 struct bpf_tramp_run_ctx __maybe_unused run_ctx;
6320
6321 switch (cmd) {
6322 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
6323 case BPF_PROG_TEST_RUN:
6324 if (attr->test.data_in || attr->test.data_out ||
6325 attr->test.ctx_out || attr->test.duration ||
6326 attr->test.repeat || attr->test.flags)
6327 return -EINVAL;
6328
6329 prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
6330 if (IS_ERR(prog))
6331 return PTR_ERR(prog);
6332
6333 if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6334 attr->test.ctx_size_in > U16_MAX) {
6335 bpf_prog_put(prog);
6336 return -EINVAL;
6337 }
6338
6339 run_ctx.bpf_cookie = 0;
6340 if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6341 /* recursion detected */
6342 __bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6343 bpf_prog_put(prog);
6344 return -EBUSY;
6345 }
6346 attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6347 __bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6348 &run_ctx);
6349 bpf_prog_put(prog);
6350 return 0;
6351 #endif
6352 default:
6353 return ____bpf_sys_bpf(cmd, attr, size);
6354 }
6355 }
6356 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL");
6357
6358 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6359 .func = bpf_sys_bpf,
6360 .gpl_only = false,
6361 .ret_type = RET_INTEGER,
6362 .arg1_type = ARG_ANYTHING,
6363 .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
6364 .arg3_type = ARG_CONST_SIZE,
6365 };
6366
6367 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6368 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6369 {
6370 return bpf_base_func_proto(func_id, prog);
6371 }
6372
BPF_CALL_1(bpf_sys_close,u32,fd)6373 BPF_CALL_1(bpf_sys_close, u32, fd)
6374 {
6375 /* When bpf program calls this helper there should not be
6376 * an fdget() without matching completed fdput().
6377 * This helper is allowed in the following callchain only:
6378 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6379 */
6380 return close_fd(fd);
6381 }
6382
6383 static const struct bpf_func_proto bpf_sys_close_proto = {
6384 .func = bpf_sys_close,
6385 .gpl_only = false,
6386 .ret_type = RET_INTEGER,
6387 .arg1_type = ARG_ANYTHING,
6388 };
6389
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6390 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6391 {
6392 *res = 0;
6393 if (flags)
6394 return -EINVAL;
6395
6396 if (name_sz <= 1 || name[name_sz - 1])
6397 return -EINVAL;
6398
6399 if (!bpf_dump_raw_ok(current_cred()))
6400 return -EPERM;
6401
6402 *res = kallsyms_lookup_name(name);
6403 return *res ? 0 : -ENOENT;
6404 }
6405
6406 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6407 .func = bpf_kallsyms_lookup_name,
6408 .gpl_only = false,
6409 .ret_type = RET_INTEGER,
6410 .arg1_type = ARG_PTR_TO_MEM,
6411 .arg2_type = ARG_CONST_SIZE_OR_ZERO,
6412 .arg3_type = ARG_ANYTHING,
6413 .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6414 .arg4_size = sizeof(u64),
6415 };
6416
6417 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6418 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6419 {
6420 switch (func_id) {
6421 case BPF_FUNC_sys_bpf:
6422 return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6423 ? NULL : &bpf_sys_bpf_proto;
6424 case BPF_FUNC_btf_find_by_name_kind:
6425 return &bpf_btf_find_by_name_kind_proto;
6426 case BPF_FUNC_sys_close:
6427 return &bpf_sys_close_proto;
6428 case BPF_FUNC_kallsyms_lookup_name:
6429 return &bpf_kallsyms_lookup_name_proto;
6430 default:
6431 return tracing_prog_func_proto(func_id, prog);
6432 }
6433 }
6434
6435 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6436 .get_func_proto = syscall_prog_func_proto,
6437 .is_valid_access = syscall_prog_is_valid_access,
6438 };
6439
6440 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6441 .test_run = bpf_prog_test_run_syscall,
6442 };
6443
6444 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6445 static int bpf_stats_handler(const struct ctl_table *table, int write,
6446 void *buffer, size_t *lenp, loff_t *ppos)
6447 {
6448 struct static_key *key = (struct static_key *)table->data;
6449 static int saved_val;
6450 int val, ret;
6451 struct ctl_table tmp = {
6452 .data = &val,
6453 .maxlen = sizeof(val),
6454 .mode = table->mode,
6455 .extra1 = SYSCTL_ZERO,
6456 .extra2 = SYSCTL_ONE,
6457 };
6458
6459 if (write && !capable(CAP_SYS_ADMIN))
6460 return -EPERM;
6461
6462 mutex_lock(&bpf_stats_enabled_mutex);
6463 val = saved_val;
6464 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6465 if (write && !ret && val != saved_val) {
6466 if (val)
6467 static_key_slow_inc(key);
6468 else
6469 static_key_slow_dec(key);
6470 saved_val = val;
6471 }
6472 mutex_unlock(&bpf_stats_enabled_mutex);
6473 return ret;
6474 }
6475
unpriv_ebpf_notify(int new_state)6476 void __weak unpriv_ebpf_notify(int new_state)
6477 {
6478 }
6479
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6480 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6481 void *buffer, size_t *lenp, loff_t *ppos)
6482 {
6483 int ret, unpriv_enable = *(int *)table->data;
6484 bool locked_state = unpriv_enable == 1;
6485 struct ctl_table tmp = *table;
6486
6487 if (write && !capable(CAP_SYS_ADMIN))
6488 return -EPERM;
6489
6490 tmp.data = &unpriv_enable;
6491 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6492 if (write && !ret) {
6493 if (locked_state && unpriv_enable != 1)
6494 return -EPERM;
6495 *(int *)table->data = unpriv_enable;
6496 }
6497
6498 if (write)
6499 unpriv_ebpf_notify(unpriv_enable);
6500
6501 return ret;
6502 }
6503
6504 static const struct ctl_table bpf_syscall_table[] = {
6505 {
6506 .procname = "unprivileged_bpf_disabled",
6507 .data = &sysctl_unprivileged_bpf_disabled,
6508 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
6509 .mode = 0644,
6510 .proc_handler = bpf_unpriv_handler,
6511 .extra1 = SYSCTL_ZERO,
6512 .extra2 = SYSCTL_TWO,
6513 },
6514 {
6515 .procname = "bpf_stats_enabled",
6516 .data = &bpf_stats_enabled_key.key,
6517 .mode = 0644,
6518 .proc_handler = bpf_stats_handler,
6519 },
6520 };
6521
bpf_syscall_sysctl_init(void)6522 static int __init bpf_syscall_sysctl_init(void)
6523 {
6524 register_sysctl_init("kernel", bpf_syscall_table);
6525 return 0;
6526 }
6527 late_initcall(bpf_syscall_sysctl_init);
6528 #endif /* CONFIG_SYSCTL */
6529