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