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