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 
39 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
40 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
41 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
42 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
43 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
44 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
45 			IS_FD_HASH(map))
46 
47 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
48 
49 DEFINE_PER_CPU(int, bpf_prog_active);
50 static DEFINE_IDR(prog_idr);
51 static DEFINE_SPINLOCK(prog_idr_lock);
52 static DEFINE_IDR(map_idr);
53 static DEFINE_SPINLOCK(map_idr_lock);
54 static DEFINE_IDR(link_idr);
55 static DEFINE_SPINLOCK(link_idr_lock);
56 
57 int sysctl_unprivileged_bpf_disabled __read_mostly =
58 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
59 
60 static const struct bpf_map_ops * const bpf_map_types[] = {
61 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
62 #define BPF_MAP_TYPE(_id, _ops) \
63 	[_id] = &_ops,
64 #define BPF_LINK_TYPE(_id, _name)
65 #include <linux/bpf_types.h>
66 #undef BPF_PROG_TYPE
67 #undef BPF_MAP_TYPE
68 #undef BPF_LINK_TYPE
69 };
70 
71 /*
72  * If we're handed a bigger struct than we know of, ensure all the unknown bits
73  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
74  * we don't know about yet.
75  *
76  * There is a ToCToU between this function call and the following
77  * copy_from_user() call. However, this is not a concern since this function is
78  * meant to be a future-proofing of bits.
79  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)80 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
81 			     size_t expected_size,
82 			     size_t actual_size)
83 {
84 	int res;
85 
86 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
87 		return -E2BIG;
88 
89 	if (actual_size <= expected_size)
90 		return 0;
91 
92 	if (uaddr.is_kernel)
93 		res = memchr_inv(uaddr.kernel + expected_size, 0,
94 				 actual_size - expected_size) == NULL;
95 	else
96 		res = check_zeroed_user(uaddr.user + expected_size,
97 					actual_size - expected_size);
98 	if (res < 0)
99 		return res;
100 	return res ? 0 : -E2BIG;
101 }
102 
103 const struct bpf_map_ops bpf_map_offload_ops = {
104 	.map_meta_equal = bpf_map_meta_equal,
105 	.map_alloc = bpf_map_offload_map_alloc,
106 	.map_free = bpf_map_offload_map_free,
107 	.map_check_btf = map_check_no_btf,
108 };
109 
find_and_alloc_map(union bpf_attr * attr)110 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
111 {
112 	const struct bpf_map_ops *ops;
113 	u32 type = attr->map_type;
114 	struct bpf_map *map;
115 	int err;
116 
117 	if (type >= ARRAY_SIZE(bpf_map_types))
118 		return ERR_PTR(-EINVAL);
119 	type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
120 	ops = bpf_map_types[type];
121 	if (!ops)
122 		return ERR_PTR(-EINVAL);
123 
124 	if (ops->map_alloc_check) {
125 		err = ops->map_alloc_check(attr);
126 		if (err)
127 			return ERR_PTR(err);
128 	}
129 	if (attr->map_ifindex)
130 		ops = &bpf_map_offload_ops;
131 	map = ops->map_alloc(attr);
132 	if (IS_ERR(map))
133 		return map;
134 	map->ops = ops;
135 	map->map_type = type;
136 	return map;
137 }
138 
bpf_map_write_active_inc(struct bpf_map * map)139 static void bpf_map_write_active_inc(struct bpf_map *map)
140 {
141 	atomic64_inc(&map->writecnt);
142 }
143 
bpf_map_write_active_dec(struct bpf_map * map)144 static void bpf_map_write_active_dec(struct bpf_map *map)
145 {
146 	atomic64_dec(&map->writecnt);
147 }
148 
bpf_map_write_active(const struct bpf_map * map)149 bool bpf_map_write_active(const struct bpf_map *map)
150 {
151 	return atomic64_read(&map->writecnt) != 0;
152 }
153 
bpf_map_value_size(const struct bpf_map * map)154 static u32 bpf_map_value_size(const struct bpf_map *map)
155 {
156 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
157 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
158 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
159 	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
160 		return round_up(map->value_size, 8) * num_possible_cpus();
161 	else if (IS_FD_MAP(map))
162 		return sizeof(u32);
163 	else
164 		return  map->value_size;
165 }
166 
maybe_wait_bpf_programs(struct bpf_map * map)167 static void maybe_wait_bpf_programs(struct bpf_map *map)
168 {
169 	/* Wait for any running BPF programs to complete so that
170 	 * userspace, when we return to it, knows that all programs
171 	 * that could be running use the new map value.
172 	 */
173 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
174 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
175 		synchronize_rcu();
176 }
177 
bpf_map_update_value(struct bpf_map * map,struct fd f,void * key,void * value,__u64 flags)178 static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
179 				void *value, __u64 flags)
180 {
181 	int err;
182 
183 	/* Need to create a kthread, thus must support schedule */
184 	if (bpf_map_is_dev_bound(map)) {
185 		return bpf_map_offload_update_elem(map, key, value, flags);
186 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
187 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
188 		return map->ops->map_update_elem(map, key, value, flags);
189 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
190 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
191 		return sock_map_update_elem_sys(map, key, value, flags);
192 	} else if (IS_FD_PROG_ARRAY(map)) {
193 		return bpf_fd_array_map_update_elem(map, f.file, key, value,
194 						    flags);
195 	}
196 
197 	bpf_disable_instrumentation();
198 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
199 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
200 		err = bpf_percpu_hash_update(map, key, value, flags);
201 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
202 		err = bpf_percpu_array_update(map, key, value, flags);
203 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
204 		err = bpf_percpu_cgroup_storage_update(map, key, value,
205 						       flags);
206 	} else if (IS_FD_ARRAY(map)) {
207 		rcu_read_lock();
208 		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
209 						   flags);
210 		rcu_read_unlock();
211 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
212 		rcu_read_lock();
213 		err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
214 						  flags);
215 		rcu_read_unlock();
216 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
217 		/* rcu_read_lock() is not needed */
218 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
219 							 flags);
220 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
221 		   map->map_type == BPF_MAP_TYPE_STACK ||
222 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
223 		err = map->ops->map_push_elem(map, value, flags);
224 	} else {
225 		rcu_read_lock();
226 		err = map->ops->map_update_elem(map, key, value, flags);
227 		rcu_read_unlock();
228 	}
229 	bpf_enable_instrumentation();
230 	maybe_wait_bpf_programs(map);
231 
232 	return err;
233 }
234 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)235 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
236 			      __u64 flags)
237 {
238 	void *ptr;
239 	int err;
240 
241 	if (bpf_map_is_dev_bound(map))
242 		return bpf_map_offload_lookup_elem(map, key, value);
243 
244 	bpf_disable_instrumentation();
245 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
246 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
247 		err = bpf_percpu_hash_copy(map, key, value);
248 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
249 		err = bpf_percpu_array_copy(map, key, value);
250 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
251 		err = bpf_percpu_cgroup_storage_copy(map, key, value);
252 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
253 		err = bpf_stackmap_copy(map, key, value);
254 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
255 		err = bpf_fd_array_map_lookup_elem(map, key, value);
256 	} else if (IS_FD_HASH(map)) {
257 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
258 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
259 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
260 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
261 		   map->map_type == BPF_MAP_TYPE_STACK ||
262 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
263 		err = map->ops->map_peek_elem(map, value);
264 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
265 		/* struct_ops map requires directly updating "value" */
266 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
267 	} else {
268 		rcu_read_lock();
269 		if (map->ops->map_lookup_elem_sys_only)
270 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
271 		else
272 			ptr = map->ops->map_lookup_elem(map, key);
273 		if (IS_ERR(ptr)) {
274 			err = PTR_ERR(ptr);
275 		} else if (!ptr) {
276 			err = -ENOENT;
277 		} else {
278 			err = 0;
279 			if (flags & BPF_F_LOCK)
280 				/* lock 'ptr' and copy everything but lock */
281 				copy_map_value_locked(map, value, ptr, true);
282 			else
283 				copy_map_value(map, value, ptr);
284 			/* mask lock and timer, since value wasn't zero inited */
285 			check_and_init_map_value(map, value);
286 		}
287 		rcu_read_unlock();
288 	}
289 
290 	bpf_enable_instrumentation();
291 	maybe_wait_bpf_programs(map);
292 
293 	return err;
294 }
295 
296 /* Please, do not use this function outside from the map creation path
297  * (e.g. in map update path) without taking care of setting the active
298  * memory cgroup (see at bpf_map_kmalloc_node() for example).
299  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)300 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
301 {
302 	/* We really just want to fail instead of triggering OOM killer
303 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
304 	 * which is used for lower order allocation requests.
305 	 *
306 	 * It has been observed that higher order allocation requests done by
307 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
308 	 * to reclaim memory from the page cache, thus we set
309 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
310 	 */
311 
312 	const gfp_t gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_ACCOUNT;
313 	unsigned int flags = 0;
314 	unsigned long align = 1;
315 	void *area;
316 
317 	if (size >= SIZE_MAX)
318 		return NULL;
319 
320 	/* kmalloc()'ed memory can't be mmap()'ed */
321 	if (mmapable) {
322 		BUG_ON(!PAGE_ALIGNED(size));
323 		align = SHMLBA;
324 		flags = VM_USERMAP;
325 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
326 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
327 				    numa_node);
328 		if (area != NULL)
329 			return area;
330 	}
331 
332 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
333 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
334 			flags, numa_node, __builtin_return_address(0));
335 }
336 
bpf_map_area_alloc(u64 size,int numa_node)337 void *bpf_map_area_alloc(u64 size, int numa_node)
338 {
339 	return __bpf_map_area_alloc(size, numa_node, false);
340 }
341 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)342 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
343 {
344 	return __bpf_map_area_alloc(size, numa_node, true);
345 }
346 
bpf_map_area_free(void * area)347 void bpf_map_area_free(void *area)
348 {
349 	kvfree(area);
350 }
351 
bpf_map_flags_retain_permanent(u32 flags)352 static u32 bpf_map_flags_retain_permanent(u32 flags)
353 {
354 	/* Some map creation flags are not tied to the map object but
355 	 * rather to the map fd instead, so they have no meaning upon
356 	 * map object inspection since multiple file descriptors with
357 	 * different (access) properties can exist here. Thus, given
358 	 * this has zero meaning for the map itself, lets clear these
359 	 * from here.
360 	 */
361 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
362 }
363 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)364 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
365 {
366 	map->map_type = attr->map_type;
367 	map->key_size = attr->key_size;
368 	map->value_size = attr->value_size;
369 	map->max_entries = attr->max_entries;
370 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
371 	map->numa_node = bpf_map_attr_numa_node(attr);
372 	map->map_extra = attr->map_extra;
373 }
374 
bpf_map_alloc_id(struct bpf_map * map)375 static int bpf_map_alloc_id(struct bpf_map *map)
376 {
377 	int id;
378 
379 	idr_preload(GFP_KERNEL);
380 	spin_lock_bh(&map_idr_lock);
381 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
382 	if (id > 0)
383 		map->id = id;
384 	spin_unlock_bh(&map_idr_lock);
385 	idr_preload_end();
386 
387 	if (WARN_ON_ONCE(!id))
388 		return -ENOSPC;
389 
390 	return id > 0 ? 0 : id;
391 }
392 
bpf_map_free_id(struct bpf_map * map,bool do_idr_lock)393 void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
394 {
395 	unsigned long flags;
396 
397 	/* Offloaded maps are removed from the IDR store when their device
398 	 * disappears - even if someone holds an fd to them they are unusable,
399 	 * the memory is gone, all ops will fail; they are simply waiting for
400 	 * refcnt to drop to be freed.
401 	 */
402 	if (!map->id)
403 		return;
404 
405 	if (do_idr_lock)
406 		spin_lock_irqsave(&map_idr_lock, flags);
407 	else
408 		__acquire(&map_idr_lock);
409 
410 	idr_remove(&map_idr, map->id);
411 	map->id = 0;
412 
413 	if (do_idr_lock)
414 		spin_unlock_irqrestore(&map_idr_lock, flags);
415 	else
416 		__release(&map_idr_lock);
417 }
418 
419 #ifdef CONFIG_MEMCG_KMEM
bpf_map_save_memcg(struct bpf_map * map)420 static void bpf_map_save_memcg(struct bpf_map *map)
421 {
422 	map->memcg = get_mem_cgroup_from_mm(current->mm);
423 }
424 
bpf_map_release_memcg(struct bpf_map * map)425 static void bpf_map_release_memcg(struct bpf_map *map)
426 {
427 	mem_cgroup_put(map->memcg);
428 }
429 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)430 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
431 			   int node)
432 {
433 	struct mem_cgroup *old_memcg;
434 	void *ptr;
435 
436 	old_memcg = set_active_memcg(map->memcg);
437 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
438 	set_active_memcg(old_memcg);
439 
440 	return ptr;
441 }
442 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)443 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
444 {
445 	struct mem_cgroup *old_memcg;
446 	void *ptr;
447 
448 	old_memcg = set_active_memcg(map->memcg);
449 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
450 	set_active_memcg(old_memcg);
451 
452 	return ptr;
453 }
454 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)455 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
456 				    size_t align, gfp_t flags)
457 {
458 	struct mem_cgroup *old_memcg;
459 	void __percpu *ptr;
460 
461 	old_memcg = set_active_memcg(map->memcg);
462 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
463 	set_active_memcg(old_memcg);
464 
465 	return ptr;
466 }
467 
468 #else
bpf_map_save_memcg(struct bpf_map * map)469 static void bpf_map_save_memcg(struct bpf_map *map)
470 {
471 }
472 
bpf_map_release_memcg(struct bpf_map * map)473 static void bpf_map_release_memcg(struct bpf_map *map)
474 {
475 }
476 #endif
477 
bpf_map_kptr_off_cmp(const void * a,const void * b)478 static int bpf_map_kptr_off_cmp(const void *a, const void *b)
479 {
480 	const struct bpf_map_value_off_desc *off_desc1 = a, *off_desc2 = b;
481 
482 	if (off_desc1->offset < off_desc2->offset)
483 		return -1;
484 	else if (off_desc1->offset > off_desc2->offset)
485 		return 1;
486 	return 0;
487 }
488 
bpf_map_kptr_off_contains(struct bpf_map * map,u32 offset)489 struct bpf_map_value_off_desc *bpf_map_kptr_off_contains(struct bpf_map *map, u32 offset)
490 {
491 	/* Since members are iterated in btf_find_field in increasing order,
492 	 * offsets appended to kptr_off_tab are in increasing order, so we can
493 	 * do bsearch to find exact match.
494 	 */
495 	struct bpf_map_value_off *tab;
496 
497 	if (!map_value_has_kptrs(map))
498 		return NULL;
499 	tab = map->kptr_off_tab;
500 	return bsearch(&offset, tab->off, tab->nr_off, sizeof(tab->off[0]), bpf_map_kptr_off_cmp);
501 }
502 
bpf_map_free_kptr_off_tab(struct bpf_map * map)503 void bpf_map_free_kptr_off_tab(struct bpf_map *map)
504 {
505 	struct bpf_map_value_off *tab = map->kptr_off_tab;
506 	int i;
507 
508 	if (!map_value_has_kptrs(map))
509 		return;
510 	for (i = 0; i < tab->nr_off; i++) {
511 		if (tab->off[i].kptr.module)
512 			module_put(tab->off[i].kptr.module);
513 		btf_put(tab->off[i].kptr.btf);
514 	}
515 	kfree(tab);
516 	map->kptr_off_tab = NULL;
517 }
518 
bpf_map_copy_kptr_off_tab(const struct bpf_map * map)519 struct bpf_map_value_off *bpf_map_copy_kptr_off_tab(const struct bpf_map *map)
520 {
521 	struct bpf_map_value_off *tab = map->kptr_off_tab, *new_tab;
522 	int size, i;
523 
524 	if (!map_value_has_kptrs(map))
525 		return ERR_PTR(-ENOENT);
526 	size = offsetof(struct bpf_map_value_off, off[tab->nr_off]);
527 	new_tab = kmemdup(tab, size, GFP_KERNEL | __GFP_NOWARN);
528 	if (!new_tab)
529 		return ERR_PTR(-ENOMEM);
530 	/* Do a deep copy of the kptr_off_tab */
531 	for (i = 0; i < tab->nr_off; i++) {
532 		btf_get(tab->off[i].kptr.btf);
533 		if (tab->off[i].kptr.module && !try_module_get(tab->off[i].kptr.module)) {
534 			while (i--) {
535 				if (tab->off[i].kptr.module)
536 					module_put(tab->off[i].kptr.module);
537 				btf_put(tab->off[i].kptr.btf);
538 			}
539 			kfree(new_tab);
540 			return ERR_PTR(-ENXIO);
541 		}
542 	}
543 	return new_tab;
544 }
545 
bpf_map_equal_kptr_off_tab(const struct bpf_map * map_a,const struct bpf_map * map_b)546 bool bpf_map_equal_kptr_off_tab(const struct bpf_map *map_a, const struct bpf_map *map_b)
547 {
548 	struct bpf_map_value_off *tab_a = map_a->kptr_off_tab, *tab_b = map_b->kptr_off_tab;
549 	bool a_has_kptr = map_value_has_kptrs(map_a), b_has_kptr = map_value_has_kptrs(map_b);
550 	int size;
551 
552 	if (!a_has_kptr && !b_has_kptr)
553 		return true;
554 	if (a_has_kptr != b_has_kptr)
555 		return false;
556 	if (tab_a->nr_off != tab_b->nr_off)
557 		return false;
558 	size = offsetof(struct bpf_map_value_off, off[tab_a->nr_off]);
559 	return !memcmp(tab_a, tab_b, size);
560 }
561 
562 /* Caller must ensure map_value_has_kptrs is true. Note that this function can
563  * be called on a map value while the map_value is visible to BPF programs, as
564  * it ensures the correct synchronization, and we already enforce the same using
565  * the bpf_kptr_xchg helper on the BPF program side for referenced kptrs.
566  */
bpf_map_free_kptrs(struct bpf_map * map,void * map_value)567 void bpf_map_free_kptrs(struct bpf_map *map, void *map_value)
568 {
569 	struct bpf_map_value_off *tab = map->kptr_off_tab;
570 	unsigned long *btf_id_ptr;
571 	int i;
572 
573 	for (i = 0; i < tab->nr_off; i++) {
574 		struct bpf_map_value_off_desc *off_desc = &tab->off[i];
575 		unsigned long old_ptr;
576 
577 		btf_id_ptr = map_value + off_desc->offset;
578 		if (off_desc->type == BPF_KPTR_UNREF) {
579 			u64 *p = (u64 *)btf_id_ptr;
580 
581 			WRITE_ONCE(p, 0);
582 			continue;
583 		}
584 		old_ptr = xchg(btf_id_ptr, 0);
585 		off_desc->kptr.dtor((void *)old_ptr);
586 	}
587 }
588 
589 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)590 static void bpf_map_free_deferred(struct work_struct *work)
591 {
592 	struct bpf_map *map = container_of(work, struct bpf_map, work);
593 
594 	security_bpf_map_free(map);
595 	kfree(map->off_arr);
596 	bpf_map_release_memcg(map);
597 	/* implementation dependent freeing, map_free callback also does
598 	 * bpf_map_free_kptr_off_tab, if needed.
599 	 */
600 	map->ops->map_free(map);
601 }
602 
bpf_map_put_uref(struct bpf_map * map)603 static void bpf_map_put_uref(struct bpf_map *map)
604 {
605 	if (atomic64_dec_and_test(&map->usercnt)) {
606 		if (map->ops->map_release_uref)
607 			map->ops->map_release_uref(map);
608 	}
609 }
610 
611 /* decrement map refcnt and schedule it for freeing via workqueue
612  * (unrelying map implementation ops->map_free() might sleep)
613  */
__bpf_map_put(struct bpf_map * map,bool do_idr_lock)614 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
615 {
616 	if (atomic64_dec_and_test(&map->refcnt)) {
617 		/* bpf_map_free_id() must be called first */
618 		bpf_map_free_id(map, do_idr_lock);
619 		btf_put(map->btf);
620 		INIT_WORK(&map->work, bpf_map_free_deferred);
621 		schedule_work(&map->work);
622 	}
623 }
624 
bpf_map_put(struct bpf_map * map)625 void bpf_map_put(struct bpf_map *map)
626 {
627 	__bpf_map_put(map, true);
628 }
629 EXPORT_SYMBOL_GPL(bpf_map_put);
630 
bpf_map_put_with_uref(struct bpf_map * map)631 void bpf_map_put_with_uref(struct bpf_map *map)
632 {
633 	bpf_map_put_uref(map);
634 	bpf_map_put(map);
635 }
636 
bpf_map_release(struct inode * inode,struct file * filp)637 static int bpf_map_release(struct inode *inode, struct file *filp)
638 {
639 	struct bpf_map *map = filp->private_data;
640 
641 	if (map->ops->map_release)
642 		map->ops->map_release(map, filp);
643 
644 	bpf_map_put_with_uref(map);
645 	return 0;
646 }
647 
map_get_sys_perms(struct bpf_map * map,struct fd f)648 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
649 {
650 	fmode_t mode = f.file->f_mode;
651 
652 	/* Our file permissions may have been overridden by global
653 	 * map permissions facing syscall side.
654 	 */
655 	if (READ_ONCE(map->frozen))
656 		mode &= ~FMODE_CAN_WRITE;
657 	return mode;
658 }
659 
660 #ifdef CONFIG_PROC_FS
661 /* Provides an approximation of the map's memory footprint.
662  * Used only to provide a backward compatibility and display
663  * a reasonable "memlock" info.
664  */
bpf_map_memory_footprint(const struct bpf_map * map)665 static unsigned long bpf_map_memory_footprint(const struct bpf_map *map)
666 {
667 	unsigned long size;
668 
669 	size = round_up(map->key_size + bpf_map_value_size(map), 8);
670 
671 	return round_up(map->max_entries * size, PAGE_SIZE);
672 }
673 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)674 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
675 {
676 	struct bpf_map *map = filp->private_data;
677 	u32 type = 0, jited = 0;
678 
679 	if (map_type_contains_progs(map)) {
680 		spin_lock(&map->owner.lock);
681 		type  = map->owner.type;
682 		jited = map->owner.jited;
683 		spin_unlock(&map->owner.lock);
684 	}
685 
686 	seq_printf(m,
687 		   "map_type:\t%u\n"
688 		   "key_size:\t%u\n"
689 		   "value_size:\t%u\n"
690 		   "max_entries:\t%u\n"
691 		   "map_flags:\t%#x\n"
692 		   "map_extra:\t%#llx\n"
693 		   "memlock:\t%lu\n"
694 		   "map_id:\t%u\n"
695 		   "frozen:\t%u\n",
696 		   map->map_type,
697 		   map->key_size,
698 		   map->value_size,
699 		   map->max_entries,
700 		   map->map_flags,
701 		   (unsigned long long)map->map_extra,
702 		   bpf_map_memory_footprint(map),
703 		   map->id,
704 		   READ_ONCE(map->frozen));
705 	if (type) {
706 		seq_printf(m, "owner_prog_type:\t%u\n", type);
707 		seq_printf(m, "owner_jited:\t%u\n", jited);
708 	}
709 }
710 #endif
711 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)712 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
713 			      loff_t *ppos)
714 {
715 	/* We need this handler such that alloc_file() enables
716 	 * f_mode with FMODE_CAN_READ.
717 	 */
718 	return -EINVAL;
719 }
720 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)721 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
722 			       size_t siz, loff_t *ppos)
723 {
724 	/* We need this handler such that alloc_file() enables
725 	 * f_mode with FMODE_CAN_WRITE.
726 	 */
727 	return -EINVAL;
728 }
729 
730 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)731 static void bpf_map_mmap_open(struct vm_area_struct *vma)
732 {
733 	struct bpf_map *map = vma->vm_file->private_data;
734 
735 	if (vma->vm_flags & VM_MAYWRITE)
736 		bpf_map_write_active_inc(map);
737 }
738 
739 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)740 static void bpf_map_mmap_close(struct vm_area_struct *vma)
741 {
742 	struct bpf_map *map = vma->vm_file->private_data;
743 
744 	if (vma->vm_flags & VM_MAYWRITE)
745 		bpf_map_write_active_dec(map);
746 }
747 
748 static const struct vm_operations_struct bpf_map_default_vmops = {
749 	.open		= bpf_map_mmap_open,
750 	.close		= bpf_map_mmap_close,
751 };
752 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)753 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
754 {
755 	struct bpf_map *map = filp->private_data;
756 	int err;
757 
758 	if (!map->ops->map_mmap || map_value_has_spin_lock(map) ||
759 	    map_value_has_timer(map) || map_value_has_kptrs(map))
760 		return -ENOTSUPP;
761 
762 	if (!(vma->vm_flags & VM_SHARED))
763 		return -EINVAL;
764 
765 	mutex_lock(&map->freeze_mutex);
766 
767 	if (vma->vm_flags & VM_WRITE) {
768 		if (map->frozen) {
769 			err = -EPERM;
770 			goto out;
771 		}
772 		/* map is meant to be read-only, so do not allow mapping as
773 		 * writable, because it's possible to leak a writable page
774 		 * reference and allows user-space to still modify it after
775 		 * freezing, while verifier will assume contents do not change
776 		 */
777 		if (map->map_flags & BPF_F_RDONLY_PROG) {
778 			err = -EACCES;
779 			goto out;
780 		}
781 	}
782 
783 	/* set default open/close callbacks */
784 	vma->vm_ops = &bpf_map_default_vmops;
785 	vma->vm_private_data = map;
786 	vma->vm_flags &= ~VM_MAYEXEC;
787 	if (!(vma->vm_flags & VM_WRITE))
788 		/* disallow re-mapping with PROT_WRITE */
789 		vma->vm_flags &= ~VM_MAYWRITE;
790 
791 	err = map->ops->map_mmap(map, vma);
792 	if (err)
793 		goto out;
794 
795 	if (vma->vm_flags & VM_MAYWRITE)
796 		bpf_map_write_active_inc(map);
797 out:
798 	mutex_unlock(&map->freeze_mutex);
799 	return err;
800 }
801 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)802 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
803 {
804 	struct bpf_map *map = filp->private_data;
805 
806 	if (map->ops->map_poll)
807 		return map->ops->map_poll(map, filp, pts);
808 
809 	return EPOLLERR;
810 }
811 
812 const struct file_operations bpf_map_fops = {
813 #ifdef CONFIG_PROC_FS
814 	.show_fdinfo	= bpf_map_show_fdinfo,
815 #endif
816 	.release	= bpf_map_release,
817 	.read		= bpf_dummy_read,
818 	.write		= bpf_dummy_write,
819 	.mmap		= bpf_map_mmap,
820 	.poll		= bpf_map_poll,
821 };
822 
bpf_map_new_fd(struct bpf_map * map,int flags)823 int bpf_map_new_fd(struct bpf_map *map, int flags)
824 {
825 	int ret;
826 
827 	ret = security_bpf_map(map, OPEN_FMODE(flags));
828 	if (ret < 0)
829 		return ret;
830 
831 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
832 				flags | O_CLOEXEC);
833 }
834 
bpf_get_file_flag(int flags)835 int bpf_get_file_flag(int flags)
836 {
837 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
838 		return -EINVAL;
839 	if (flags & BPF_F_RDONLY)
840 		return O_RDONLY;
841 	if (flags & BPF_F_WRONLY)
842 		return O_WRONLY;
843 	return O_RDWR;
844 }
845 
846 /* helper macro to check that unused fields 'union bpf_attr' are zero */
847 #define CHECK_ATTR(CMD) \
848 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
849 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
850 		   sizeof(*attr) - \
851 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
852 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
853 
854 /* dst and src must have at least "size" number of bytes.
855  * Return strlen on success and < 0 on error.
856  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)857 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
858 {
859 	const char *end = src + size;
860 	const char *orig_src = src;
861 
862 	memset(dst, 0, size);
863 	/* Copy all isalnum(), '_' and '.' chars. */
864 	while (src < end && *src) {
865 		if (!isalnum(*src) &&
866 		    *src != '_' && *src != '.')
867 			return -EINVAL;
868 		*dst++ = *src++;
869 	}
870 
871 	/* No '\0' found in "size" number of bytes */
872 	if (src == end)
873 		return -EINVAL;
874 
875 	return src - orig_src;
876 }
877 
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)878 int map_check_no_btf(const struct bpf_map *map,
879 		     const struct btf *btf,
880 		     const struct btf_type *key_type,
881 		     const struct btf_type *value_type)
882 {
883 	return -ENOTSUPP;
884 }
885 
map_off_arr_cmp(const void * _a,const void * _b,const void * priv)886 static int map_off_arr_cmp(const void *_a, const void *_b, const void *priv)
887 {
888 	const u32 a = *(const u32 *)_a;
889 	const u32 b = *(const u32 *)_b;
890 
891 	if (a < b)
892 		return -1;
893 	else if (a > b)
894 		return 1;
895 	return 0;
896 }
897 
map_off_arr_swap(void * _a,void * _b,int size,const void * priv)898 static void map_off_arr_swap(void *_a, void *_b, int size, const void *priv)
899 {
900 	struct bpf_map *map = (struct bpf_map *)priv;
901 	u32 *off_base = map->off_arr->field_off;
902 	u32 *a = _a, *b = _b;
903 	u8 *sz_a, *sz_b;
904 
905 	sz_a = map->off_arr->field_sz + (a - off_base);
906 	sz_b = map->off_arr->field_sz + (b - off_base);
907 
908 	swap(*a, *b);
909 	swap(*sz_a, *sz_b);
910 }
911 
bpf_map_alloc_off_arr(struct bpf_map * map)912 static int bpf_map_alloc_off_arr(struct bpf_map *map)
913 {
914 	bool has_spin_lock = map_value_has_spin_lock(map);
915 	bool has_timer = map_value_has_timer(map);
916 	bool has_kptrs = map_value_has_kptrs(map);
917 	struct bpf_map_off_arr *off_arr;
918 	u32 i;
919 
920 	if (!has_spin_lock && !has_timer && !has_kptrs) {
921 		map->off_arr = NULL;
922 		return 0;
923 	}
924 
925 	off_arr = kmalloc(sizeof(*map->off_arr), GFP_KERNEL | __GFP_NOWARN);
926 	if (!off_arr)
927 		return -ENOMEM;
928 	map->off_arr = off_arr;
929 
930 	off_arr->cnt = 0;
931 	if (has_spin_lock) {
932 		i = off_arr->cnt;
933 
934 		off_arr->field_off[i] = map->spin_lock_off;
935 		off_arr->field_sz[i] = sizeof(struct bpf_spin_lock);
936 		off_arr->cnt++;
937 	}
938 	if (has_timer) {
939 		i = off_arr->cnt;
940 
941 		off_arr->field_off[i] = map->timer_off;
942 		off_arr->field_sz[i] = sizeof(struct bpf_timer);
943 		off_arr->cnt++;
944 	}
945 	if (has_kptrs) {
946 		struct bpf_map_value_off *tab = map->kptr_off_tab;
947 		u32 *off = &off_arr->field_off[off_arr->cnt];
948 		u8 *sz = &off_arr->field_sz[off_arr->cnt];
949 
950 		for (i = 0; i < tab->nr_off; i++) {
951 			*off++ = tab->off[i].offset;
952 			*sz++ = sizeof(u64);
953 		}
954 		off_arr->cnt += tab->nr_off;
955 	}
956 
957 	if (off_arr->cnt == 1)
958 		return 0;
959 	sort_r(off_arr->field_off, off_arr->cnt, sizeof(off_arr->field_off[0]),
960 	       map_off_arr_cmp, map_off_arr_swap, map);
961 	return 0;
962 }
963 
map_check_btf(struct bpf_map * map,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)964 static int map_check_btf(struct bpf_map *map, const struct btf *btf,
965 			 u32 btf_key_id, u32 btf_value_id)
966 {
967 	const struct btf_type *key_type, *value_type;
968 	u32 key_size, value_size;
969 	int ret = 0;
970 
971 	/* Some maps allow key to be unspecified. */
972 	if (btf_key_id) {
973 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
974 		if (!key_type || key_size != map->key_size)
975 			return -EINVAL;
976 	} else {
977 		key_type = btf_type_by_id(btf, 0);
978 		if (!map->ops->map_check_btf)
979 			return -EINVAL;
980 	}
981 
982 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
983 	if (!value_type || value_size != map->value_size)
984 		return -EINVAL;
985 
986 	map->spin_lock_off = btf_find_spin_lock(btf, value_type);
987 
988 	if (map_value_has_spin_lock(map)) {
989 		if (map->map_flags & BPF_F_RDONLY_PROG)
990 			return -EACCES;
991 		if (map->map_type != BPF_MAP_TYPE_HASH &&
992 		    map->map_type != BPF_MAP_TYPE_ARRAY &&
993 		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
994 		    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
995 		    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
996 		    map->map_type != BPF_MAP_TYPE_TASK_STORAGE)
997 			return -ENOTSUPP;
998 		if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
999 		    map->value_size) {
1000 			WARN_ONCE(1,
1001 				  "verifier bug spin_lock_off %d value_size %d\n",
1002 				  map->spin_lock_off, map->value_size);
1003 			return -EFAULT;
1004 		}
1005 	}
1006 
1007 	map->timer_off = btf_find_timer(btf, value_type);
1008 	if (map_value_has_timer(map)) {
1009 		if (map->map_flags & BPF_F_RDONLY_PROG)
1010 			return -EACCES;
1011 		if (map->map_type != BPF_MAP_TYPE_HASH &&
1012 		    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1013 		    map->map_type != BPF_MAP_TYPE_ARRAY)
1014 			return -EOPNOTSUPP;
1015 	}
1016 
1017 	map->kptr_off_tab = btf_parse_kptrs(btf, value_type);
1018 	if (map_value_has_kptrs(map)) {
1019 		if (!bpf_capable()) {
1020 			ret = -EPERM;
1021 			goto free_map_tab;
1022 		}
1023 		if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1024 			ret = -EACCES;
1025 			goto free_map_tab;
1026 		}
1027 		if (map->map_type != BPF_MAP_TYPE_HASH &&
1028 		    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1029 		    map->map_type != BPF_MAP_TYPE_ARRAY) {
1030 			ret = -EOPNOTSUPP;
1031 			goto free_map_tab;
1032 		}
1033 	}
1034 
1035 	if (map->ops->map_check_btf) {
1036 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1037 		if (ret < 0)
1038 			goto free_map_tab;
1039 	}
1040 
1041 	return ret;
1042 free_map_tab:
1043 	bpf_map_free_kptr_off_tab(map);
1044 	return ret;
1045 }
1046 
1047 #define BPF_MAP_CREATE_LAST_FIELD map_extra
1048 /* called via syscall */
map_create(union bpf_attr * attr)1049 static int map_create(union bpf_attr *attr)
1050 {
1051 	int numa_node = bpf_map_attr_numa_node(attr);
1052 	struct bpf_map *map;
1053 	int f_flags;
1054 	int err;
1055 
1056 	err = CHECK_ATTR(BPF_MAP_CREATE);
1057 	if (err)
1058 		return -EINVAL;
1059 
1060 	if (attr->btf_vmlinux_value_type_id) {
1061 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1062 		    attr->btf_key_type_id || attr->btf_value_type_id)
1063 			return -EINVAL;
1064 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1065 		return -EINVAL;
1066 	}
1067 
1068 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1069 	    attr->map_extra != 0)
1070 		return -EINVAL;
1071 
1072 	f_flags = bpf_get_file_flag(attr->map_flags);
1073 	if (f_flags < 0)
1074 		return f_flags;
1075 
1076 	if (numa_node != NUMA_NO_NODE &&
1077 	    ((unsigned int)numa_node >= nr_node_ids ||
1078 	     !node_online(numa_node)))
1079 		return -EINVAL;
1080 
1081 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1082 	map = find_and_alloc_map(attr);
1083 	if (IS_ERR(map))
1084 		return PTR_ERR(map);
1085 
1086 	err = bpf_obj_name_cpy(map->name, attr->map_name,
1087 			       sizeof(attr->map_name));
1088 	if (err < 0)
1089 		goto free_map;
1090 
1091 	atomic64_set(&map->refcnt, 1);
1092 	atomic64_set(&map->usercnt, 1);
1093 	mutex_init(&map->freeze_mutex);
1094 	spin_lock_init(&map->owner.lock);
1095 
1096 	map->spin_lock_off = -EINVAL;
1097 	map->timer_off = -EINVAL;
1098 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
1099 	    /* Even the map's value is a kernel's struct,
1100 	     * the bpf_prog.o must have BTF to begin with
1101 	     * to figure out the corresponding kernel's
1102 	     * counter part.  Thus, attr->btf_fd has
1103 	     * to be valid also.
1104 	     */
1105 	    attr->btf_vmlinux_value_type_id) {
1106 		struct btf *btf;
1107 
1108 		btf = btf_get_by_fd(attr->btf_fd);
1109 		if (IS_ERR(btf)) {
1110 			err = PTR_ERR(btf);
1111 			goto free_map;
1112 		}
1113 		if (btf_is_kernel(btf)) {
1114 			btf_put(btf);
1115 			err = -EACCES;
1116 			goto free_map;
1117 		}
1118 		map->btf = btf;
1119 
1120 		if (attr->btf_value_type_id) {
1121 			err = map_check_btf(map, btf, attr->btf_key_type_id,
1122 					    attr->btf_value_type_id);
1123 			if (err)
1124 				goto free_map;
1125 		}
1126 
1127 		map->btf_key_type_id = attr->btf_key_type_id;
1128 		map->btf_value_type_id = attr->btf_value_type_id;
1129 		map->btf_vmlinux_value_type_id =
1130 			attr->btf_vmlinux_value_type_id;
1131 	}
1132 
1133 	err = bpf_map_alloc_off_arr(map);
1134 	if (err)
1135 		goto free_map;
1136 
1137 	err = security_bpf_map_alloc(map);
1138 	if (err)
1139 		goto free_map_off_arr;
1140 
1141 	err = bpf_map_alloc_id(map);
1142 	if (err)
1143 		goto free_map_sec;
1144 
1145 	bpf_map_save_memcg(map);
1146 
1147 	err = bpf_map_new_fd(map, f_flags);
1148 	if (err < 0) {
1149 		/* failed to allocate fd.
1150 		 * bpf_map_put_with_uref() is needed because the above
1151 		 * bpf_map_alloc_id() has published the map
1152 		 * to the userspace and the userspace may
1153 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1154 		 */
1155 		bpf_map_put_with_uref(map);
1156 		return err;
1157 	}
1158 
1159 	return err;
1160 
1161 free_map_sec:
1162 	security_bpf_map_free(map);
1163 free_map_off_arr:
1164 	kfree(map->off_arr);
1165 free_map:
1166 	btf_put(map->btf);
1167 	map->ops->map_free(map);
1168 	return err;
1169 }
1170 
1171 /* if error is returned, fd is released.
1172  * On success caller should complete fd access with matching fdput()
1173  */
__bpf_map_get(struct fd f)1174 struct bpf_map *__bpf_map_get(struct fd f)
1175 {
1176 	if (!f.file)
1177 		return ERR_PTR(-EBADF);
1178 	if (f.file->f_op != &bpf_map_fops) {
1179 		fdput(f);
1180 		return ERR_PTR(-EINVAL);
1181 	}
1182 
1183 	return f.file->private_data;
1184 }
1185 
bpf_map_inc(struct bpf_map * map)1186 void bpf_map_inc(struct bpf_map *map)
1187 {
1188 	atomic64_inc(&map->refcnt);
1189 }
1190 EXPORT_SYMBOL_GPL(bpf_map_inc);
1191 
bpf_map_inc_with_uref(struct bpf_map * map)1192 void bpf_map_inc_with_uref(struct bpf_map *map)
1193 {
1194 	atomic64_inc(&map->refcnt);
1195 	atomic64_inc(&map->usercnt);
1196 }
1197 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1198 
bpf_map_get(u32 ufd)1199 struct bpf_map *bpf_map_get(u32 ufd)
1200 {
1201 	struct fd f = fdget(ufd);
1202 	struct bpf_map *map;
1203 
1204 	map = __bpf_map_get(f);
1205 	if (IS_ERR(map))
1206 		return map;
1207 
1208 	bpf_map_inc(map);
1209 	fdput(f);
1210 
1211 	return map;
1212 }
1213 EXPORT_SYMBOL(bpf_map_get);
1214 
bpf_map_get_with_uref(u32 ufd)1215 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1216 {
1217 	struct fd f = fdget(ufd);
1218 	struct bpf_map *map;
1219 
1220 	map = __bpf_map_get(f);
1221 	if (IS_ERR(map))
1222 		return map;
1223 
1224 	bpf_map_inc_with_uref(map);
1225 	fdput(f);
1226 
1227 	return map;
1228 }
1229 
1230 /* map_idr_lock should have been held */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1231 static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1232 {
1233 	int refold;
1234 
1235 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1236 	if (!refold)
1237 		return ERR_PTR(-ENOENT);
1238 	if (uref)
1239 		atomic64_inc(&map->usercnt);
1240 
1241 	return map;
1242 }
1243 
bpf_map_inc_not_zero(struct bpf_map * map)1244 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1245 {
1246 	spin_lock_bh(&map_idr_lock);
1247 	map = __bpf_map_inc_not_zero(map, false);
1248 	spin_unlock_bh(&map_idr_lock);
1249 
1250 	return map;
1251 }
1252 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1253 
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1254 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1255 {
1256 	return -ENOTSUPP;
1257 }
1258 
__bpf_copy_key(void __user * ukey,u64 key_size)1259 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1260 {
1261 	if (key_size)
1262 		return vmemdup_user(ukey, key_size);
1263 
1264 	if (ukey)
1265 		return ERR_PTR(-EINVAL);
1266 
1267 	return NULL;
1268 }
1269 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1270 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1271 {
1272 	if (key_size)
1273 		return kvmemdup_bpfptr(ukey, key_size);
1274 
1275 	if (!bpfptr_is_null(ukey))
1276 		return ERR_PTR(-EINVAL);
1277 
1278 	return NULL;
1279 }
1280 
1281 /* last field in 'union bpf_attr' used by this command */
1282 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1283 
map_lookup_elem(union bpf_attr * attr)1284 static int map_lookup_elem(union bpf_attr *attr)
1285 {
1286 	void __user *ukey = u64_to_user_ptr(attr->key);
1287 	void __user *uvalue = u64_to_user_ptr(attr->value);
1288 	int ufd = attr->map_fd;
1289 	struct bpf_map *map;
1290 	void *key, *value;
1291 	u32 value_size;
1292 	struct fd f;
1293 	int err;
1294 
1295 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1296 		return -EINVAL;
1297 
1298 	if (attr->flags & ~BPF_F_LOCK)
1299 		return -EINVAL;
1300 
1301 	f = fdget(ufd);
1302 	map = __bpf_map_get(f);
1303 	if (IS_ERR(map))
1304 		return PTR_ERR(map);
1305 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1306 		err = -EPERM;
1307 		goto err_put;
1308 	}
1309 
1310 	if ((attr->flags & BPF_F_LOCK) &&
1311 	    !map_value_has_spin_lock(map)) {
1312 		err = -EINVAL;
1313 		goto err_put;
1314 	}
1315 
1316 	key = __bpf_copy_key(ukey, map->key_size);
1317 	if (IS_ERR(key)) {
1318 		err = PTR_ERR(key);
1319 		goto err_put;
1320 	}
1321 
1322 	value_size = bpf_map_value_size(map);
1323 
1324 	err = -ENOMEM;
1325 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1326 	if (!value)
1327 		goto free_key;
1328 
1329 	if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1330 		if (copy_from_user(value, uvalue, value_size))
1331 			err = -EFAULT;
1332 		else
1333 			err = bpf_map_copy_value(map, key, value, attr->flags);
1334 		goto free_value;
1335 	}
1336 
1337 	err = bpf_map_copy_value(map, key, value, attr->flags);
1338 	if (err)
1339 		goto free_value;
1340 
1341 	err = -EFAULT;
1342 	if (copy_to_user(uvalue, value, value_size) != 0)
1343 		goto free_value;
1344 
1345 	err = 0;
1346 
1347 free_value:
1348 	kvfree(value);
1349 free_key:
1350 	kvfree(key);
1351 err_put:
1352 	fdput(f);
1353 	return err;
1354 }
1355 
1356 
1357 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1358 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1359 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1360 {
1361 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1362 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1363 	int ufd = attr->map_fd;
1364 	struct bpf_map *map;
1365 	void *key, *value;
1366 	u32 value_size;
1367 	struct fd f;
1368 	int err;
1369 
1370 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1371 		return -EINVAL;
1372 
1373 	f = fdget(ufd);
1374 	map = __bpf_map_get(f);
1375 	if (IS_ERR(map))
1376 		return PTR_ERR(map);
1377 	bpf_map_write_active_inc(map);
1378 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1379 		err = -EPERM;
1380 		goto err_put;
1381 	}
1382 
1383 	if ((attr->flags & BPF_F_LOCK) &&
1384 	    !map_value_has_spin_lock(map)) {
1385 		err = -EINVAL;
1386 		goto err_put;
1387 	}
1388 
1389 	key = ___bpf_copy_key(ukey, map->key_size);
1390 	if (IS_ERR(key)) {
1391 		err = PTR_ERR(key);
1392 		goto err_put;
1393 	}
1394 
1395 	value_size = bpf_map_value_size(map);
1396 
1397 	err = -ENOMEM;
1398 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1399 	if (!value)
1400 		goto free_key;
1401 
1402 	err = -EFAULT;
1403 	if (copy_from_bpfptr(value, uvalue, value_size) != 0)
1404 		goto free_value;
1405 
1406 	err = bpf_map_update_value(map, f, key, value, attr->flags);
1407 
1408 free_value:
1409 	kvfree(value);
1410 free_key:
1411 	kvfree(key);
1412 err_put:
1413 	bpf_map_write_active_dec(map);
1414 	fdput(f);
1415 	return err;
1416 }
1417 
1418 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1419 
map_delete_elem(union bpf_attr * attr)1420 static int map_delete_elem(union bpf_attr *attr)
1421 {
1422 	void __user *ukey = u64_to_user_ptr(attr->key);
1423 	int ufd = attr->map_fd;
1424 	struct bpf_map *map;
1425 	struct fd f;
1426 	void *key;
1427 	int err;
1428 
1429 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1430 		return -EINVAL;
1431 
1432 	f = fdget(ufd);
1433 	map = __bpf_map_get(f);
1434 	if (IS_ERR(map))
1435 		return PTR_ERR(map);
1436 	bpf_map_write_active_inc(map);
1437 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1438 		err = -EPERM;
1439 		goto err_put;
1440 	}
1441 
1442 	key = __bpf_copy_key(ukey, map->key_size);
1443 	if (IS_ERR(key)) {
1444 		err = PTR_ERR(key);
1445 		goto err_put;
1446 	}
1447 
1448 	if (bpf_map_is_dev_bound(map)) {
1449 		err = bpf_map_offload_delete_elem(map, key);
1450 		goto out;
1451 	} else if (IS_FD_PROG_ARRAY(map) ||
1452 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1453 		/* These maps require sleepable context */
1454 		err = map->ops->map_delete_elem(map, key);
1455 		goto out;
1456 	}
1457 
1458 	bpf_disable_instrumentation();
1459 	rcu_read_lock();
1460 	err = map->ops->map_delete_elem(map, key);
1461 	rcu_read_unlock();
1462 	bpf_enable_instrumentation();
1463 	maybe_wait_bpf_programs(map);
1464 out:
1465 	kvfree(key);
1466 err_put:
1467 	bpf_map_write_active_dec(map);
1468 	fdput(f);
1469 	return err;
1470 }
1471 
1472 /* last field in 'union bpf_attr' used by this command */
1473 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1474 
map_get_next_key(union bpf_attr * attr)1475 static int map_get_next_key(union bpf_attr *attr)
1476 {
1477 	void __user *ukey = u64_to_user_ptr(attr->key);
1478 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1479 	int ufd = attr->map_fd;
1480 	struct bpf_map *map;
1481 	void *key, *next_key;
1482 	struct fd f;
1483 	int err;
1484 
1485 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1486 		return -EINVAL;
1487 
1488 	f = fdget(ufd);
1489 	map = __bpf_map_get(f);
1490 	if (IS_ERR(map))
1491 		return PTR_ERR(map);
1492 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1493 		err = -EPERM;
1494 		goto err_put;
1495 	}
1496 
1497 	if (ukey) {
1498 		key = __bpf_copy_key(ukey, map->key_size);
1499 		if (IS_ERR(key)) {
1500 			err = PTR_ERR(key);
1501 			goto err_put;
1502 		}
1503 	} else {
1504 		key = NULL;
1505 	}
1506 
1507 	err = -ENOMEM;
1508 	next_key = kvmalloc(map->key_size, GFP_USER);
1509 	if (!next_key)
1510 		goto free_key;
1511 
1512 	if (bpf_map_is_dev_bound(map)) {
1513 		err = bpf_map_offload_get_next_key(map, key, next_key);
1514 		goto out;
1515 	}
1516 
1517 	rcu_read_lock();
1518 	err = map->ops->map_get_next_key(map, key, next_key);
1519 	rcu_read_unlock();
1520 out:
1521 	if (err)
1522 		goto free_next_key;
1523 
1524 	err = -EFAULT;
1525 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1526 		goto free_next_key;
1527 
1528 	err = 0;
1529 
1530 free_next_key:
1531 	kvfree(next_key);
1532 free_key:
1533 	kvfree(key);
1534 err_put:
1535 	fdput(f);
1536 	return err;
1537 }
1538 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1539 int generic_map_delete_batch(struct bpf_map *map,
1540 			     const union bpf_attr *attr,
1541 			     union bpf_attr __user *uattr)
1542 {
1543 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1544 	u32 cp, max_count;
1545 	int err = 0;
1546 	void *key;
1547 
1548 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1549 		return -EINVAL;
1550 
1551 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1552 	    !map_value_has_spin_lock(map)) {
1553 		return -EINVAL;
1554 	}
1555 
1556 	max_count = attr->batch.count;
1557 	if (!max_count)
1558 		return 0;
1559 
1560 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1561 	if (!key)
1562 		return -ENOMEM;
1563 
1564 	for (cp = 0; cp < max_count; cp++) {
1565 		err = -EFAULT;
1566 		if (copy_from_user(key, keys + cp * map->key_size,
1567 				   map->key_size))
1568 			break;
1569 
1570 		if (bpf_map_is_dev_bound(map)) {
1571 			err = bpf_map_offload_delete_elem(map, key);
1572 			break;
1573 		}
1574 
1575 		bpf_disable_instrumentation();
1576 		rcu_read_lock();
1577 		err = map->ops->map_delete_elem(map, key);
1578 		rcu_read_unlock();
1579 		bpf_enable_instrumentation();
1580 		if (err)
1581 			break;
1582 		cond_resched();
1583 	}
1584 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1585 		err = -EFAULT;
1586 
1587 	kvfree(key);
1588 
1589 	maybe_wait_bpf_programs(map);
1590 	return err;
1591 }
1592 
generic_map_update_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1593 int generic_map_update_batch(struct bpf_map *map,
1594 			     const union bpf_attr *attr,
1595 			     union bpf_attr __user *uattr)
1596 {
1597 	void __user *values = u64_to_user_ptr(attr->batch.values);
1598 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1599 	u32 value_size, cp, max_count;
1600 	int ufd = attr->batch.map_fd;
1601 	void *key, *value;
1602 	struct fd f;
1603 	int err = 0;
1604 
1605 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1606 		return -EINVAL;
1607 
1608 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1609 	    !map_value_has_spin_lock(map)) {
1610 		return -EINVAL;
1611 	}
1612 
1613 	value_size = bpf_map_value_size(map);
1614 
1615 	max_count = attr->batch.count;
1616 	if (!max_count)
1617 		return 0;
1618 
1619 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1620 	if (!key)
1621 		return -ENOMEM;
1622 
1623 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1624 	if (!value) {
1625 		kvfree(key);
1626 		return -ENOMEM;
1627 	}
1628 
1629 	f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */
1630 	for (cp = 0; cp < max_count; cp++) {
1631 		err = -EFAULT;
1632 		if (copy_from_user(key, keys + cp * map->key_size,
1633 		    map->key_size) ||
1634 		    copy_from_user(value, values + cp * value_size, value_size))
1635 			break;
1636 
1637 		err = bpf_map_update_value(map, f, key, value,
1638 					   attr->batch.elem_flags);
1639 
1640 		if (err)
1641 			break;
1642 		cond_resched();
1643 	}
1644 
1645 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1646 		err = -EFAULT;
1647 
1648 	kvfree(value);
1649 	kvfree(key);
1650 	fdput(f);
1651 	return err;
1652 }
1653 
1654 #define MAP_LOOKUP_RETRIES 3
1655 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1656 int generic_map_lookup_batch(struct bpf_map *map,
1657 				    const union bpf_attr *attr,
1658 				    union bpf_attr __user *uattr)
1659 {
1660 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
1661 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1662 	void __user *values = u64_to_user_ptr(attr->batch.values);
1663 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1664 	void *buf, *buf_prevkey, *prev_key, *key, *value;
1665 	int err, retry = MAP_LOOKUP_RETRIES;
1666 	u32 value_size, cp, max_count;
1667 
1668 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1669 		return -EINVAL;
1670 
1671 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1672 	    !map_value_has_spin_lock(map))
1673 		return -EINVAL;
1674 
1675 	value_size = bpf_map_value_size(map);
1676 
1677 	max_count = attr->batch.count;
1678 	if (!max_count)
1679 		return 0;
1680 
1681 	if (put_user(0, &uattr->batch.count))
1682 		return -EFAULT;
1683 
1684 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1685 	if (!buf_prevkey)
1686 		return -ENOMEM;
1687 
1688 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
1689 	if (!buf) {
1690 		kvfree(buf_prevkey);
1691 		return -ENOMEM;
1692 	}
1693 
1694 	err = -EFAULT;
1695 	prev_key = NULL;
1696 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
1697 		goto free_buf;
1698 	key = buf;
1699 	value = key + map->key_size;
1700 	if (ubatch)
1701 		prev_key = buf_prevkey;
1702 
1703 	for (cp = 0; cp < max_count;) {
1704 		rcu_read_lock();
1705 		err = map->ops->map_get_next_key(map, prev_key, key);
1706 		rcu_read_unlock();
1707 		if (err)
1708 			break;
1709 		err = bpf_map_copy_value(map, key, value,
1710 					 attr->batch.elem_flags);
1711 
1712 		if (err == -ENOENT) {
1713 			if (retry) {
1714 				retry--;
1715 				continue;
1716 			}
1717 			err = -EINTR;
1718 			break;
1719 		}
1720 
1721 		if (err)
1722 			goto free_buf;
1723 
1724 		if (copy_to_user(keys + cp * map->key_size, key,
1725 				 map->key_size)) {
1726 			err = -EFAULT;
1727 			goto free_buf;
1728 		}
1729 		if (copy_to_user(values + cp * value_size, value, value_size)) {
1730 			err = -EFAULT;
1731 			goto free_buf;
1732 		}
1733 
1734 		if (!prev_key)
1735 			prev_key = buf_prevkey;
1736 
1737 		swap(prev_key, key);
1738 		retry = MAP_LOOKUP_RETRIES;
1739 		cp++;
1740 		cond_resched();
1741 	}
1742 
1743 	if (err == -EFAULT)
1744 		goto free_buf;
1745 
1746 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
1747 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
1748 		err = -EFAULT;
1749 
1750 free_buf:
1751 	kvfree(buf_prevkey);
1752 	kvfree(buf);
1753 	return err;
1754 }
1755 
1756 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
1757 
map_lookup_and_delete_elem(union bpf_attr * attr)1758 static int map_lookup_and_delete_elem(union bpf_attr *attr)
1759 {
1760 	void __user *ukey = u64_to_user_ptr(attr->key);
1761 	void __user *uvalue = u64_to_user_ptr(attr->value);
1762 	int ufd = attr->map_fd;
1763 	struct bpf_map *map;
1764 	void *key, *value;
1765 	u32 value_size;
1766 	struct fd f;
1767 	int err;
1768 
1769 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
1770 		return -EINVAL;
1771 
1772 	if (attr->flags & ~BPF_F_LOCK)
1773 		return -EINVAL;
1774 
1775 	f = fdget(ufd);
1776 	map = __bpf_map_get(f);
1777 	if (IS_ERR(map))
1778 		return PTR_ERR(map);
1779 	bpf_map_write_active_inc(map);
1780 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
1781 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1782 		err = -EPERM;
1783 		goto err_put;
1784 	}
1785 
1786 	if (attr->flags &&
1787 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
1788 	     map->map_type == BPF_MAP_TYPE_STACK)) {
1789 		err = -EINVAL;
1790 		goto err_put;
1791 	}
1792 
1793 	if ((attr->flags & BPF_F_LOCK) &&
1794 	    !map_value_has_spin_lock(map)) {
1795 		err = -EINVAL;
1796 		goto err_put;
1797 	}
1798 
1799 	key = __bpf_copy_key(ukey, map->key_size);
1800 	if (IS_ERR(key)) {
1801 		err = PTR_ERR(key);
1802 		goto err_put;
1803 	}
1804 
1805 	value_size = bpf_map_value_size(map);
1806 
1807 	err = -ENOMEM;
1808 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1809 	if (!value)
1810 		goto free_key;
1811 
1812 	err = -ENOTSUPP;
1813 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
1814 	    map->map_type == BPF_MAP_TYPE_STACK) {
1815 		err = map->ops->map_pop_elem(map, value);
1816 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
1817 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
1818 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
1819 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
1820 		if (!bpf_map_is_dev_bound(map)) {
1821 			bpf_disable_instrumentation();
1822 			rcu_read_lock();
1823 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
1824 			rcu_read_unlock();
1825 			bpf_enable_instrumentation();
1826 		}
1827 	}
1828 
1829 	if (err)
1830 		goto free_value;
1831 
1832 	if (copy_to_user(uvalue, value, value_size) != 0) {
1833 		err = -EFAULT;
1834 		goto free_value;
1835 	}
1836 
1837 	err = 0;
1838 
1839 free_value:
1840 	kvfree(value);
1841 free_key:
1842 	kvfree(key);
1843 err_put:
1844 	bpf_map_write_active_dec(map);
1845 	fdput(f);
1846 	return err;
1847 }
1848 
1849 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
1850 
map_freeze(const union bpf_attr * attr)1851 static int map_freeze(const union bpf_attr *attr)
1852 {
1853 	int err = 0, ufd = attr->map_fd;
1854 	struct bpf_map *map;
1855 	struct fd f;
1856 
1857 	if (CHECK_ATTR(BPF_MAP_FREEZE))
1858 		return -EINVAL;
1859 
1860 	f = fdget(ufd);
1861 	map = __bpf_map_get(f);
1862 	if (IS_ERR(map))
1863 		return PTR_ERR(map);
1864 
1865 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS ||
1866 	    map_value_has_timer(map) || map_value_has_kptrs(map)) {
1867 		fdput(f);
1868 		return -ENOTSUPP;
1869 	}
1870 
1871 	mutex_lock(&map->freeze_mutex);
1872 	if (bpf_map_write_active(map)) {
1873 		err = -EBUSY;
1874 		goto err_put;
1875 	}
1876 	if (READ_ONCE(map->frozen)) {
1877 		err = -EBUSY;
1878 		goto err_put;
1879 	}
1880 	if (!bpf_capable()) {
1881 		err = -EPERM;
1882 		goto err_put;
1883 	}
1884 
1885 	WRITE_ONCE(map->frozen, true);
1886 err_put:
1887 	mutex_unlock(&map->freeze_mutex);
1888 	fdput(f);
1889 	return err;
1890 }
1891 
1892 static const struct bpf_prog_ops * const bpf_prog_types[] = {
1893 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
1894 	[_id] = & _name ## _prog_ops,
1895 #define BPF_MAP_TYPE(_id, _ops)
1896 #define BPF_LINK_TYPE(_id, _name)
1897 #include <linux/bpf_types.h>
1898 #undef BPF_PROG_TYPE
1899 #undef BPF_MAP_TYPE
1900 #undef BPF_LINK_TYPE
1901 };
1902 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)1903 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
1904 {
1905 	const struct bpf_prog_ops *ops;
1906 
1907 	if (type >= ARRAY_SIZE(bpf_prog_types))
1908 		return -EINVAL;
1909 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
1910 	ops = bpf_prog_types[type];
1911 	if (!ops)
1912 		return -EINVAL;
1913 
1914 	if (!bpf_prog_is_dev_bound(prog->aux))
1915 		prog->aux->ops = ops;
1916 	else
1917 		prog->aux->ops = &bpf_offload_prog_ops;
1918 	prog->type = type;
1919 	return 0;
1920 }
1921 
1922 enum bpf_audit {
1923 	BPF_AUDIT_LOAD,
1924 	BPF_AUDIT_UNLOAD,
1925 	BPF_AUDIT_MAX,
1926 };
1927 
1928 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
1929 	[BPF_AUDIT_LOAD]   = "LOAD",
1930 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
1931 };
1932 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)1933 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
1934 {
1935 	struct audit_context *ctx = NULL;
1936 	struct audit_buffer *ab;
1937 
1938 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
1939 		return;
1940 	if (audit_enabled == AUDIT_OFF)
1941 		return;
1942 	if (op == BPF_AUDIT_LOAD)
1943 		ctx = audit_context();
1944 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
1945 	if (unlikely(!ab))
1946 		return;
1947 	audit_log_format(ab, "prog-id=%u op=%s",
1948 			 prog->aux->id, bpf_audit_str[op]);
1949 	audit_log_end(ab);
1950 }
1951 
bpf_prog_alloc_id(struct bpf_prog * prog)1952 static int bpf_prog_alloc_id(struct bpf_prog *prog)
1953 {
1954 	int id;
1955 
1956 	idr_preload(GFP_KERNEL);
1957 	spin_lock_bh(&prog_idr_lock);
1958 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
1959 	if (id > 0)
1960 		prog->aux->id = id;
1961 	spin_unlock_bh(&prog_idr_lock);
1962 	idr_preload_end();
1963 
1964 	/* id is in [1, INT_MAX) */
1965 	if (WARN_ON_ONCE(!id))
1966 		return -ENOSPC;
1967 
1968 	return id > 0 ? 0 : id;
1969 }
1970 
bpf_prog_free_id(struct bpf_prog * prog,bool do_idr_lock)1971 void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
1972 {
1973 	unsigned long flags;
1974 
1975 	/* cBPF to eBPF migrations are currently not in the idr store.
1976 	 * Offloaded programs are removed from the store when their device
1977 	 * disappears - even if someone grabs an fd to them they are unusable,
1978 	 * simply waiting for refcnt to drop to be freed.
1979 	 */
1980 	if (!prog->aux->id)
1981 		return;
1982 
1983 	if (do_idr_lock)
1984 		spin_lock_irqsave(&prog_idr_lock, flags);
1985 	else
1986 		__acquire(&prog_idr_lock);
1987 
1988 	idr_remove(&prog_idr, prog->aux->id);
1989 	prog->aux->id = 0;
1990 
1991 	if (do_idr_lock)
1992 		spin_unlock_irqrestore(&prog_idr_lock, flags);
1993 	else
1994 		__release(&prog_idr_lock);
1995 }
1996 
__bpf_prog_put_rcu(struct rcu_head * rcu)1997 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
1998 {
1999 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2000 
2001 	kvfree(aux->func_info);
2002 	kfree(aux->func_info_aux);
2003 	free_uid(aux->user);
2004 	security_bpf_prog_free(aux);
2005 	bpf_prog_free(aux->prog);
2006 }
2007 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2008 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2009 {
2010 	bpf_prog_kallsyms_del_all(prog);
2011 	btf_put(prog->aux->btf);
2012 	kvfree(prog->aux->jited_linfo);
2013 	kvfree(prog->aux->linfo);
2014 	kfree(prog->aux->kfunc_tab);
2015 	if (prog->aux->attach_btf)
2016 		btf_put(prog->aux->attach_btf);
2017 
2018 	if (deferred) {
2019 		if (prog->aux->sleepable)
2020 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2021 		else
2022 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2023 	} else {
2024 		__bpf_prog_put_rcu(&prog->aux->rcu);
2025 	}
2026 }
2027 
bpf_prog_put_deferred(struct work_struct * work)2028 static void bpf_prog_put_deferred(struct work_struct *work)
2029 {
2030 	struct bpf_prog_aux *aux;
2031 	struct bpf_prog *prog;
2032 
2033 	aux = container_of(work, struct bpf_prog_aux, work);
2034 	prog = aux->prog;
2035 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2036 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2037 	__bpf_prog_put_noref(prog, true);
2038 }
2039 
__bpf_prog_put(struct bpf_prog * prog,bool do_idr_lock)2040 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
2041 {
2042 	struct bpf_prog_aux *aux = prog->aux;
2043 
2044 	if (atomic64_dec_and_test(&aux->refcnt)) {
2045 		/* bpf_prog_free_id() must be called first */
2046 		bpf_prog_free_id(prog, do_idr_lock);
2047 
2048 		if (in_irq() || irqs_disabled()) {
2049 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
2050 			schedule_work(&aux->work);
2051 		} else {
2052 			bpf_prog_put_deferred(&aux->work);
2053 		}
2054 	}
2055 }
2056 
bpf_prog_put(struct bpf_prog * prog)2057 void bpf_prog_put(struct bpf_prog *prog)
2058 {
2059 	__bpf_prog_put(prog, true);
2060 }
2061 EXPORT_SYMBOL_GPL(bpf_prog_put);
2062 
bpf_prog_release(struct inode * inode,struct file * filp)2063 static int bpf_prog_release(struct inode *inode, struct file *filp)
2064 {
2065 	struct bpf_prog *prog = filp->private_data;
2066 
2067 	bpf_prog_put(prog);
2068 	return 0;
2069 }
2070 
2071 struct bpf_prog_kstats {
2072 	u64 nsecs;
2073 	u64 cnt;
2074 	u64 misses;
2075 };
2076 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2077 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2078 			       struct bpf_prog_kstats *stats)
2079 {
2080 	u64 nsecs = 0, cnt = 0, misses = 0;
2081 	int cpu;
2082 
2083 	for_each_possible_cpu(cpu) {
2084 		const struct bpf_prog_stats *st;
2085 		unsigned int start;
2086 		u64 tnsecs, tcnt, tmisses;
2087 
2088 		st = per_cpu_ptr(prog->stats, cpu);
2089 		do {
2090 			start = u64_stats_fetch_begin_irq(&st->syncp);
2091 			tnsecs = u64_stats_read(&st->nsecs);
2092 			tcnt = u64_stats_read(&st->cnt);
2093 			tmisses = u64_stats_read(&st->misses);
2094 		} while (u64_stats_fetch_retry_irq(&st->syncp, start));
2095 		nsecs += tnsecs;
2096 		cnt += tcnt;
2097 		misses += tmisses;
2098 	}
2099 	stats->nsecs = nsecs;
2100 	stats->cnt = cnt;
2101 	stats->misses = misses;
2102 }
2103 
2104 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2105 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2106 {
2107 	const struct bpf_prog *prog = filp->private_data;
2108 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2109 	struct bpf_prog_kstats stats;
2110 
2111 	bpf_prog_get_stats(prog, &stats);
2112 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2113 	seq_printf(m,
2114 		   "prog_type:\t%u\n"
2115 		   "prog_jited:\t%u\n"
2116 		   "prog_tag:\t%s\n"
2117 		   "memlock:\t%llu\n"
2118 		   "prog_id:\t%u\n"
2119 		   "run_time_ns:\t%llu\n"
2120 		   "run_cnt:\t%llu\n"
2121 		   "recursion_misses:\t%llu\n"
2122 		   "verified_insns:\t%u\n",
2123 		   prog->type,
2124 		   prog->jited,
2125 		   prog_tag,
2126 		   prog->pages * 1ULL << PAGE_SHIFT,
2127 		   prog->aux->id,
2128 		   stats.nsecs,
2129 		   stats.cnt,
2130 		   stats.misses,
2131 		   prog->aux->verified_insns);
2132 }
2133 #endif
2134 
2135 const struct file_operations bpf_prog_fops = {
2136 #ifdef CONFIG_PROC_FS
2137 	.show_fdinfo	= bpf_prog_show_fdinfo,
2138 #endif
2139 	.release	= bpf_prog_release,
2140 	.read		= bpf_dummy_read,
2141 	.write		= bpf_dummy_write,
2142 };
2143 
bpf_prog_new_fd(struct bpf_prog * prog)2144 int bpf_prog_new_fd(struct bpf_prog *prog)
2145 {
2146 	int ret;
2147 
2148 	ret = security_bpf_prog(prog);
2149 	if (ret < 0)
2150 		return ret;
2151 
2152 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2153 				O_RDWR | O_CLOEXEC);
2154 }
2155 
____bpf_prog_get(struct fd f)2156 static struct bpf_prog *____bpf_prog_get(struct fd f)
2157 {
2158 	if (!f.file)
2159 		return ERR_PTR(-EBADF);
2160 	if (f.file->f_op != &bpf_prog_fops) {
2161 		fdput(f);
2162 		return ERR_PTR(-EINVAL);
2163 	}
2164 
2165 	return f.file->private_data;
2166 }
2167 
bpf_prog_add(struct bpf_prog * prog,int i)2168 void bpf_prog_add(struct bpf_prog *prog, int i)
2169 {
2170 	atomic64_add(i, &prog->aux->refcnt);
2171 }
2172 EXPORT_SYMBOL_GPL(bpf_prog_add);
2173 
bpf_prog_sub(struct bpf_prog * prog,int i)2174 void bpf_prog_sub(struct bpf_prog *prog, int i)
2175 {
2176 	/* Only to be used for undoing previous bpf_prog_add() in some
2177 	 * error path. We still know that another entity in our call
2178 	 * path holds a reference to the program, thus atomic_sub() can
2179 	 * be safely used in such cases!
2180 	 */
2181 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2182 }
2183 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2184 
bpf_prog_inc(struct bpf_prog * prog)2185 void bpf_prog_inc(struct bpf_prog *prog)
2186 {
2187 	atomic64_inc(&prog->aux->refcnt);
2188 }
2189 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2190 
2191 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2192 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2193 {
2194 	int refold;
2195 
2196 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2197 
2198 	if (!refold)
2199 		return ERR_PTR(-ENOENT);
2200 
2201 	return prog;
2202 }
2203 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2204 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2205 bool bpf_prog_get_ok(struct bpf_prog *prog,
2206 			    enum bpf_prog_type *attach_type, bool attach_drv)
2207 {
2208 	/* not an attachment, just a refcount inc, always allow */
2209 	if (!attach_type)
2210 		return true;
2211 
2212 	if (prog->type != *attach_type)
2213 		return false;
2214 	if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
2215 		return false;
2216 
2217 	return true;
2218 }
2219 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2220 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2221 				       bool attach_drv)
2222 {
2223 	struct fd f = fdget(ufd);
2224 	struct bpf_prog *prog;
2225 
2226 	prog = ____bpf_prog_get(f);
2227 	if (IS_ERR(prog))
2228 		return prog;
2229 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
2230 		prog = ERR_PTR(-EINVAL);
2231 		goto out;
2232 	}
2233 
2234 	bpf_prog_inc(prog);
2235 out:
2236 	fdput(f);
2237 	return prog;
2238 }
2239 
bpf_prog_get(u32 ufd)2240 struct bpf_prog *bpf_prog_get(u32 ufd)
2241 {
2242 	return __bpf_prog_get(ufd, NULL, false);
2243 }
2244 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2245 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2246 				       bool attach_drv)
2247 {
2248 	return __bpf_prog_get(ufd, &type, attach_drv);
2249 }
2250 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2251 
2252 /* Initially all BPF programs could be loaded w/o specifying
2253  * expected_attach_type. Later for some of them specifying expected_attach_type
2254  * at load time became required so that program could be validated properly.
2255  * Programs of types that are allowed to be loaded both w/ and w/o (for
2256  * backward compatibility) expected_attach_type, should have the default attach
2257  * type assigned to expected_attach_type for the latter case, so that it can be
2258  * validated later at attach time.
2259  *
2260  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2261  * prog type requires it but has some attach types that have to be backward
2262  * compatible.
2263  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2264 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2265 {
2266 	switch (attr->prog_type) {
2267 	case BPF_PROG_TYPE_CGROUP_SOCK:
2268 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2269 		 * exist so checking for non-zero is the way to go here.
2270 		 */
2271 		if (!attr->expected_attach_type)
2272 			attr->expected_attach_type =
2273 				BPF_CGROUP_INET_SOCK_CREATE;
2274 		break;
2275 	case BPF_PROG_TYPE_SK_REUSEPORT:
2276 		if (!attr->expected_attach_type)
2277 			attr->expected_attach_type =
2278 				BPF_SK_REUSEPORT_SELECT;
2279 		break;
2280 	}
2281 }
2282 
2283 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)2284 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2285 			   enum bpf_attach_type expected_attach_type,
2286 			   struct btf *attach_btf, u32 btf_id,
2287 			   struct bpf_prog *dst_prog)
2288 {
2289 	if (btf_id) {
2290 		if (btf_id > BTF_MAX_TYPE)
2291 			return -EINVAL;
2292 
2293 		if (!attach_btf && !dst_prog)
2294 			return -EINVAL;
2295 
2296 		switch (prog_type) {
2297 		case BPF_PROG_TYPE_TRACING:
2298 		case BPF_PROG_TYPE_LSM:
2299 		case BPF_PROG_TYPE_STRUCT_OPS:
2300 		case BPF_PROG_TYPE_EXT:
2301 			break;
2302 		default:
2303 			return -EINVAL;
2304 		}
2305 	}
2306 
2307 	if (attach_btf && (!btf_id || dst_prog))
2308 		return -EINVAL;
2309 
2310 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2311 	    prog_type != BPF_PROG_TYPE_EXT)
2312 		return -EINVAL;
2313 
2314 	switch (prog_type) {
2315 	case BPF_PROG_TYPE_CGROUP_SOCK:
2316 		switch (expected_attach_type) {
2317 		case BPF_CGROUP_INET_SOCK_CREATE:
2318 		case BPF_CGROUP_INET_SOCK_RELEASE:
2319 		case BPF_CGROUP_INET4_POST_BIND:
2320 		case BPF_CGROUP_INET6_POST_BIND:
2321 			return 0;
2322 		default:
2323 			return -EINVAL;
2324 		}
2325 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2326 		switch (expected_attach_type) {
2327 		case BPF_CGROUP_INET4_BIND:
2328 		case BPF_CGROUP_INET6_BIND:
2329 		case BPF_CGROUP_INET4_CONNECT:
2330 		case BPF_CGROUP_INET6_CONNECT:
2331 		case BPF_CGROUP_INET4_GETPEERNAME:
2332 		case BPF_CGROUP_INET6_GETPEERNAME:
2333 		case BPF_CGROUP_INET4_GETSOCKNAME:
2334 		case BPF_CGROUP_INET6_GETSOCKNAME:
2335 		case BPF_CGROUP_UDP4_SENDMSG:
2336 		case BPF_CGROUP_UDP6_SENDMSG:
2337 		case BPF_CGROUP_UDP4_RECVMSG:
2338 		case BPF_CGROUP_UDP6_RECVMSG:
2339 			return 0;
2340 		default:
2341 			return -EINVAL;
2342 		}
2343 	case BPF_PROG_TYPE_CGROUP_SKB:
2344 		switch (expected_attach_type) {
2345 		case BPF_CGROUP_INET_INGRESS:
2346 		case BPF_CGROUP_INET_EGRESS:
2347 			return 0;
2348 		default:
2349 			return -EINVAL;
2350 		}
2351 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2352 		switch (expected_attach_type) {
2353 		case BPF_CGROUP_SETSOCKOPT:
2354 		case BPF_CGROUP_GETSOCKOPT:
2355 			return 0;
2356 		default:
2357 			return -EINVAL;
2358 		}
2359 	case BPF_PROG_TYPE_SK_LOOKUP:
2360 		if (expected_attach_type == BPF_SK_LOOKUP)
2361 			return 0;
2362 		return -EINVAL;
2363 	case BPF_PROG_TYPE_SK_REUSEPORT:
2364 		switch (expected_attach_type) {
2365 		case BPF_SK_REUSEPORT_SELECT:
2366 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2367 			return 0;
2368 		default:
2369 			return -EINVAL;
2370 		}
2371 	case BPF_PROG_TYPE_SYSCALL:
2372 	case BPF_PROG_TYPE_EXT:
2373 		if (expected_attach_type)
2374 			return -EINVAL;
2375 		fallthrough;
2376 	default:
2377 		return 0;
2378 	}
2379 }
2380 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2381 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2382 {
2383 	switch (prog_type) {
2384 	case BPF_PROG_TYPE_SCHED_CLS:
2385 	case BPF_PROG_TYPE_SCHED_ACT:
2386 	case BPF_PROG_TYPE_XDP:
2387 	case BPF_PROG_TYPE_LWT_IN:
2388 	case BPF_PROG_TYPE_LWT_OUT:
2389 	case BPF_PROG_TYPE_LWT_XMIT:
2390 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2391 	case BPF_PROG_TYPE_SK_SKB:
2392 	case BPF_PROG_TYPE_SK_MSG:
2393 	case BPF_PROG_TYPE_LIRC_MODE2:
2394 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2395 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2396 	case BPF_PROG_TYPE_CGROUP_SOCK:
2397 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2398 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2399 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2400 	case BPF_PROG_TYPE_SOCK_OPS:
2401 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2402 		return true;
2403 	case BPF_PROG_TYPE_CGROUP_SKB:
2404 		/* always unpriv */
2405 	case BPF_PROG_TYPE_SK_REUSEPORT:
2406 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2407 	default:
2408 		return false;
2409 	}
2410 }
2411 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2412 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2413 {
2414 	switch (prog_type) {
2415 	case BPF_PROG_TYPE_KPROBE:
2416 	case BPF_PROG_TYPE_TRACEPOINT:
2417 	case BPF_PROG_TYPE_PERF_EVENT:
2418 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2419 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2420 	case BPF_PROG_TYPE_TRACING:
2421 	case BPF_PROG_TYPE_LSM:
2422 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2423 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2424 		return true;
2425 	default:
2426 		return false;
2427 	}
2428 }
2429 
2430 /* last field in 'union bpf_attr' used by this command */
2431 #define	BPF_PROG_LOAD_LAST_FIELD core_relo_rec_size
2432 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr)2433 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
2434 {
2435 	enum bpf_prog_type type = attr->prog_type;
2436 	struct bpf_prog *prog, *dst_prog = NULL;
2437 	struct btf *attach_btf = NULL;
2438 	int err;
2439 	char license[128];
2440 	bool is_gpl;
2441 
2442 	if (CHECK_ATTR(BPF_PROG_LOAD))
2443 		return -EINVAL;
2444 
2445 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2446 				 BPF_F_ANY_ALIGNMENT |
2447 				 BPF_F_TEST_STATE_FREQ |
2448 				 BPF_F_SLEEPABLE |
2449 				 BPF_F_TEST_RND_HI32 |
2450 				 BPF_F_XDP_HAS_FRAGS))
2451 		return -EINVAL;
2452 
2453 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2454 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2455 	    !bpf_capable())
2456 		return -EPERM;
2457 
2458 	/* copy eBPF program license from user space */
2459 	if (strncpy_from_bpfptr(license,
2460 				make_bpfptr(attr->license, uattr.is_kernel),
2461 				sizeof(license) - 1) < 0)
2462 		return -EFAULT;
2463 	license[sizeof(license) - 1] = 0;
2464 
2465 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
2466 	is_gpl = license_is_gpl_compatible(license);
2467 
2468 	if (attr->insn_cnt == 0 ||
2469 	    attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
2470 		return -E2BIG;
2471 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2472 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2473 	    !bpf_capable())
2474 		return -EPERM;
2475 
2476 	if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
2477 		return -EPERM;
2478 	if (is_perfmon_prog_type(type) && !perfmon_capable())
2479 		return -EPERM;
2480 
2481 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2482 	 * or btf, we need to check which one it is
2483 	 */
2484 	if (attr->attach_prog_fd) {
2485 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2486 		if (IS_ERR(dst_prog)) {
2487 			dst_prog = NULL;
2488 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2489 			if (IS_ERR(attach_btf))
2490 				return -EINVAL;
2491 			if (!btf_is_kernel(attach_btf)) {
2492 				/* attaching through specifying bpf_prog's BTF
2493 				 * objects directly might be supported eventually
2494 				 */
2495 				btf_put(attach_btf);
2496 				return -ENOTSUPP;
2497 			}
2498 		}
2499 	} else if (attr->attach_btf_id) {
2500 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2501 		attach_btf = bpf_get_btf_vmlinux();
2502 		if (IS_ERR(attach_btf))
2503 			return PTR_ERR(attach_btf);
2504 		if (!attach_btf)
2505 			return -EINVAL;
2506 		btf_get(attach_btf);
2507 	}
2508 
2509 	bpf_prog_load_fixup_attach_type(attr);
2510 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2511 				       attach_btf, attr->attach_btf_id,
2512 				       dst_prog)) {
2513 		if (dst_prog)
2514 			bpf_prog_put(dst_prog);
2515 		if (attach_btf)
2516 			btf_put(attach_btf);
2517 		return -EINVAL;
2518 	}
2519 
2520 	/* plain bpf_prog allocation */
2521 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2522 	if (!prog) {
2523 		if (dst_prog)
2524 			bpf_prog_put(dst_prog);
2525 		if (attach_btf)
2526 			btf_put(attach_btf);
2527 		return -ENOMEM;
2528 	}
2529 
2530 	prog->expected_attach_type = attr->expected_attach_type;
2531 	prog->aux->attach_btf = attach_btf;
2532 	prog->aux->attach_btf_id = attr->attach_btf_id;
2533 	prog->aux->dst_prog = dst_prog;
2534 	prog->aux->offload_requested = !!attr->prog_ifindex;
2535 	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
2536 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
2537 
2538 	err = security_bpf_prog_alloc(prog->aux);
2539 	if (err)
2540 		goto free_prog;
2541 
2542 	prog->aux->user = get_current_user();
2543 	prog->len = attr->insn_cnt;
2544 
2545 	err = -EFAULT;
2546 	if (copy_from_bpfptr(prog->insns,
2547 			     make_bpfptr(attr->insns, uattr.is_kernel),
2548 			     bpf_prog_insn_size(prog)) != 0)
2549 		goto free_prog_sec;
2550 
2551 	prog->orig_prog = NULL;
2552 	prog->jited = 0;
2553 
2554 	atomic64_set(&prog->aux->refcnt, 1);
2555 	prog->gpl_compatible = is_gpl ? 1 : 0;
2556 
2557 	if (bpf_prog_is_dev_bound(prog->aux)) {
2558 		err = bpf_prog_offload_init(prog, attr);
2559 		if (err)
2560 			goto free_prog_sec;
2561 	}
2562 
2563 	/* find program type: socket_filter vs tracing_filter */
2564 	err = find_prog_type(type, prog);
2565 	if (err < 0)
2566 		goto free_prog_sec;
2567 
2568 	prog->aux->load_time = ktime_get_boottime_ns();
2569 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2570 			       sizeof(attr->prog_name));
2571 	if (err < 0)
2572 		goto free_prog_sec;
2573 
2574 	/* run eBPF verifier */
2575 	err = bpf_check(&prog, attr, uattr);
2576 	if (err < 0)
2577 		goto free_used_maps;
2578 
2579 	prog = bpf_prog_select_runtime(prog, &err);
2580 	if (err < 0)
2581 		goto free_used_maps;
2582 
2583 	err = bpf_prog_alloc_id(prog);
2584 	if (err)
2585 		goto free_used_maps;
2586 
2587 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
2588 	 * effectively publicly exposed. However, retrieving via
2589 	 * bpf_prog_get_fd_by_id() will take another reference,
2590 	 * therefore it cannot be gone underneath us.
2591 	 *
2592 	 * Only for the time /after/ successful bpf_prog_new_fd()
2593 	 * and before returning to userspace, we might just hold
2594 	 * one reference and any parallel close on that fd could
2595 	 * rip everything out. Hence, below notifications must
2596 	 * happen before bpf_prog_new_fd().
2597 	 *
2598 	 * Also, any failure handling from this point onwards must
2599 	 * be using bpf_prog_put() given the program is exposed.
2600 	 */
2601 	bpf_prog_kallsyms_add(prog);
2602 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2603 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
2604 
2605 	err = bpf_prog_new_fd(prog);
2606 	if (err < 0)
2607 		bpf_prog_put(prog);
2608 	return err;
2609 
2610 free_used_maps:
2611 	/* In case we have subprogs, we need to wait for a grace
2612 	 * period before we can tear down JIT memory since symbols
2613 	 * are already exposed under kallsyms.
2614 	 */
2615 	__bpf_prog_put_noref(prog, prog->aux->func_cnt);
2616 	return err;
2617 free_prog_sec:
2618 	free_uid(prog->aux->user);
2619 	security_bpf_prog_free(prog->aux);
2620 free_prog:
2621 	if (prog->aux->attach_btf)
2622 		btf_put(prog->aux->attach_btf);
2623 	bpf_prog_free(prog);
2624 	return err;
2625 }
2626 
2627 #define BPF_OBJ_LAST_FIELD file_flags
2628 
bpf_obj_pin(const union bpf_attr * attr)2629 static int bpf_obj_pin(const union bpf_attr *attr)
2630 {
2631 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
2632 		return -EINVAL;
2633 
2634 	return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
2635 }
2636 
bpf_obj_get(const union bpf_attr * attr)2637 static int bpf_obj_get(const union bpf_attr *attr)
2638 {
2639 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
2640 	    attr->file_flags & ~BPF_OBJ_FLAG_MASK)
2641 		return -EINVAL;
2642 
2643 	return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
2644 				attr->file_flags);
2645 }
2646 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)2647 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
2648 		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
2649 {
2650 	atomic64_set(&link->refcnt, 1);
2651 	link->type = type;
2652 	link->id = 0;
2653 	link->ops = ops;
2654 	link->prog = prog;
2655 }
2656 
bpf_link_free_id(int id)2657 static void bpf_link_free_id(int id)
2658 {
2659 	if (!id)
2660 		return;
2661 
2662 	spin_lock_bh(&link_idr_lock);
2663 	idr_remove(&link_idr, id);
2664 	spin_unlock_bh(&link_idr_lock);
2665 }
2666 
2667 /* Clean up bpf_link and corresponding anon_inode file and FD. After
2668  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
2669  * anon_inode's release() call. This helper marksbpf_link as
2670  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
2671  * is not decremented, it's the responsibility of a calling code that failed
2672  * to complete bpf_link initialization.
2673  */
bpf_link_cleanup(struct bpf_link_primer * primer)2674 void bpf_link_cleanup(struct bpf_link_primer *primer)
2675 {
2676 	primer->link->prog = NULL;
2677 	bpf_link_free_id(primer->id);
2678 	fput(primer->file);
2679 	put_unused_fd(primer->fd);
2680 }
2681 
bpf_link_inc(struct bpf_link * link)2682 void bpf_link_inc(struct bpf_link *link)
2683 {
2684 	atomic64_inc(&link->refcnt);
2685 }
2686 
2687 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)2688 static void bpf_link_free(struct bpf_link *link)
2689 {
2690 	bpf_link_free_id(link->id);
2691 	if (link->prog) {
2692 		/* detach BPF program, clean up used resources */
2693 		link->ops->release(link);
2694 		bpf_prog_put(link->prog);
2695 	}
2696 	/* free bpf_link and its containing memory */
2697 	link->ops->dealloc(link);
2698 }
2699 
bpf_link_put_deferred(struct work_struct * work)2700 static void bpf_link_put_deferred(struct work_struct *work)
2701 {
2702 	struct bpf_link *link = container_of(work, struct bpf_link, work);
2703 
2704 	bpf_link_free(link);
2705 }
2706 
2707 /* bpf_link_put can be called from atomic context, but ensures that resources
2708  * are freed from process context
2709  */
bpf_link_put(struct bpf_link * link)2710 void bpf_link_put(struct bpf_link *link)
2711 {
2712 	if (!atomic64_dec_and_test(&link->refcnt))
2713 		return;
2714 
2715 	if (in_atomic()) {
2716 		INIT_WORK(&link->work, bpf_link_put_deferred);
2717 		schedule_work(&link->work);
2718 	} else {
2719 		bpf_link_free(link);
2720 	}
2721 }
2722 EXPORT_SYMBOL(bpf_link_put);
2723 
bpf_link_release(struct inode * inode,struct file * filp)2724 static int bpf_link_release(struct inode *inode, struct file *filp)
2725 {
2726 	struct bpf_link *link = filp->private_data;
2727 
2728 	bpf_link_put(link);
2729 	return 0;
2730 }
2731 
2732 #ifdef CONFIG_PROC_FS
2733 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
2734 #define BPF_MAP_TYPE(_id, _ops)
2735 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
2736 static const char *bpf_link_type_strs[] = {
2737 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
2738 #include <linux/bpf_types.h>
2739 };
2740 #undef BPF_PROG_TYPE
2741 #undef BPF_MAP_TYPE
2742 #undef BPF_LINK_TYPE
2743 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)2744 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
2745 {
2746 	const struct bpf_link *link = filp->private_data;
2747 	const struct bpf_prog *prog = link->prog;
2748 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2749 
2750 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2751 	seq_printf(m,
2752 		   "link_type:\t%s\n"
2753 		   "link_id:\t%u\n"
2754 		   "prog_tag:\t%s\n"
2755 		   "prog_id:\t%u\n",
2756 		   bpf_link_type_strs[link->type],
2757 		   link->id,
2758 		   prog_tag,
2759 		   prog->aux->id);
2760 	if (link->ops->show_fdinfo)
2761 		link->ops->show_fdinfo(link, m);
2762 }
2763 #endif
2764 
2765 static const struct file_operations bpf_link_fops = {
2766 #ifdef CONFIG_PROC_FS
2767 	.show_fdinfo	= bpf_link_show_fdinfo,
2768 #endif
2769 	.release	= bpf_link_release,
2770 	.read		= bpf_dummy_read,
2771 	.write		= bpf_dummy_write,
2772 };
2773 
bpf_link_alloc_id(struct bpf_link * link)2774 static int bpf_link_alloc_id(struct bpf_link *link)
2775 {
2776 	int id;
2777 
2778 	idr_preload(GFP_KERNEL);
2779 	spin_lock_bh(&link_idr_lock);
2780 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
2781 	spin_unlock_bh(&link_idr_lock);
2782 	idr_preload_end();
2783 
2784 	return id;
2785 }
2786 
2787 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
2788  * reserving unused FD and allocating ID from link_idr. This is to be paired
2789  * with bpf_link_settle() to install FD and ID and expose bpf_link to
2790  * user-space, if bpf_link is successfully attached. If not, bpf_link and
2791  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
2792  * transient state is passed around in struct bpf_link_primer.
2793  * This is preferred way to create and initialize bpf_link, especially when
2794  * there are complicated and expensive operations in between creating bpf_link
2795  * itself and attaching it to BPF hook. By using bpf_link_prime() and
2796  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
2797  * expensive (and potentially failing) roll back operations in a rare case
2798  * that file, FD, or ID can't be allocated.
2799  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)2800 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
2801 {
2802 	struct file *file;
2803 	int fd, id;
2804 
2805 	fd = get_unused_fd_flags(O_CLOEXEC);
2806 	if (fd < 0)
2807 		return fd;
2808 
2809 
2810 	id = bpf_link_alloc_id(link);
2811 	if (id < 0) {
2812 		put_unused_fd(fd);
2813 		return id;
2814 	}
2815 
2816 	file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
2817 	if (IS_ERR(file)) {
2818 		bpf_link_free_id(id);
2819 		put_unused_fd(fd);
2820 		return PTR_ERR(file);
2821 	}
2822 
2823 	primer->link = link;
2824 	primer->file = file;
2825 	primer->fd = fd;
2826 	primer->id = id;
2827 	return 0;
2828 }
2829 
bpf_link_settle(struct bpf_link_primer * primer)2830 int bpf_link_settle(struct bpf_link_primer *primer)
2831 {
2832 	/* make bpf_link fetchable by ID */
2833 	spin_lock_bh(&link_idr_lock);
2834 	primer->link->id = primer->id;
2835 	spin_unlock_bh(&link_idr_lock);
2836 	/* make bpf_link fetchable by FD */
2837 	fd_install(primer->fd, primer->file);
2838 	/* pass through installed FD */
2839 	return primer->fd;
2840 }
2841 
bpf_link_new_fd(struct bpf_link * link)2842 int bpf_link_new_fd(struct bpf_link *link)
2843 {
2844 	return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
2845 }
2846 
bpf_link_get_from_fd(u32 ufd)2847 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
2848 {
2849 	struct fd f = fdget(ufd);
2850 	struct bpf_link *link;
2851 
2852 	if (!f.file)
2853 		return ERR_PTR(-EBADF);
2854 	if (f.file->f_op != &bpf_link_fops) {
2855 		fdput(f);
2856 		return ERR_PTR(-EINVAL);
2857 	}
2858 
2859 	link = f.file->private_data;
2860 	bpf_link_inc(link);
2861 	fdput(f);
2862 
2863 	return link;
2864 }
2865 EXPORT_SYMBOL(bpf_link_get_from_fd);
2866 
bpf_tracing_link_release(struct bpf_link * link)2867 static void bpf_tracing_link_release(struct bpf_link *link)
2868 {
2869 	struct bpf_tracing_link *tr_link =
2870 		container_of(link, struct bpf_tracing_link, link.link);
2871 
2872 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
2873 						tr_link->trampoline));
2874 
2875 	bpf_trampoline_put(tr_link->trampoline);
2876 
2877 	/* tgt_prog is NULL if target is a kernel function */
2878 	if (tr_link->tgt_prog)
2879 		bpf_prog_put(tr_link->tgt_prog);
2880 }
2881 
bpf_tracing_link_dealloc(struct bpf_link * link)2882 static void bpf_tracing_link_dealloc(struct bpf_link *link)
2883 {
2884 	struct bpf_tracing_link *tr_link =
2885 		container_of(link, struct bpf_tracing_link, link.link);
2886 
2887 	kfree(tr_link);
2888 }
2889 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)2890 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
2891 					 struct seq_file *seq)
2892 {
2893 	struct bpf_tracing_link *tr_link =
2894 		container_of(link, struct bpf_tracing_link, link.link);
2895 
2896 	seq_printf(seq,
2897 		   "attach_type:\t%d\n",
2898 		   tr_link->attach_type);
2899 }
2900 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2901 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
2902 					   struct bpf_link_info *info)
2903 {
2904 	struct bpf_tracing_link *tr_link =
2905 		container_of(link, struct bpf_tracing_link, link.link);
2906 
2907 	info->tracing.attach_type = tr_link->attach_type;
2908 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
2909 				  &info->tracing.target_obj_id,
2910 				  &info->tracing.target_btf_id);
2911 
2912 	return 0;
2913 }
2914 
2915 static const struct bpf_link_ops bpf_tracing_link_lops = {
2916 	.release = bpf_tracing_link_release,
2917 	.dealloc = bpf_tracing_link_dealloc,
2918 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
2919 	.fill_link_info = bpf_tracing_link_fill_link_info,
2920 };
2921 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)2922 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
2923 				   int tgt_prog_fd,
2924 				   u32 btf_id,
2925 				   u64 bpf_cookie)
2926 {
2927 	struct bpf_link_primer link_primer;
2928 	struct bpf_prog *tgt_prog = NULL;
2929 	struct bpf_trampoline *tr = NULL;
2930 	struct bpf_tracing_link *link;
2931 	u64 key = 0;
2932 	int err;
2933 
2934 	switch (prog->type) {
2935 	case BPF_PROG_TYPE_TRACING:
2936 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
2937 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
2938 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
2939 			err = -EINVAL;
2940 			goto out_put_prog;
2941 		}
2942 		break;
2943 	case BPF_PROG_TYPE_EXT:
2944 		if (prog->expected_attach_type != 0) {
2945 			err = -EINVAL;
2946 			goto out_put_prog;
2947 		}
2948 		break;
2949 	case BPF_PROG_TYPE_LSM:
2950 		if (prog->expected_attach_type != BPF_LSM_MAC) {
2951 			err = -EINVAL;
2952 			goto out_put_prog;
2953 		}
2954 		break;
2955 	default:
2956 		err = -EINVAL;
2957 		goto out_put_prog;
2958 	}
2959 
2960 	if (!!tgt_prog_fd != !!btf_id) {
2961 		err = -EINVAL;
2962 		goto out_put_prog;
2963 	}
2964 
2965 	if (tgt_prog_fd) {
2966 		/* For now we only allow new targets for BPF_PROG_TYPE_EXT */
2967 		if (prog->type != BPF_PROG_TYPE_EXT) {
2968 			err = -EINVAL;
2969 			goto out_put_prog;
2970 		}
2971 
2972 		tgt_prog = bpf_prog_get(tgt_prog_fd);
2973 		if (IS_ERR(tgt_prog)) {
2974 			err = PTR_ERR(tgt_prog);
2975 			tgt_prog = NULL;
2976 			goto out_put_prog;
2977 		}
2978 
2979 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
2980 	}
2981 
2982 	link = kzalloc(sizeof(*link), GFP_USER);
2983 	if (!link) {
2984 		err = -ENOMEM;
2985 		goto out_put_prog;
2986 	}
2987 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
2988 		      &bpf_tracing_link_lops, prog);
2989 	link->attach_type = prog->expected_attach_type;
2990 	link->link.cookie = bpf_cookie;
2991 
2992 	mutex_lock(&prog->aux->dst_mutex);
2993 
2994 	/* There are a few possible cases here:
2995 	 *
2996 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
2997 	 *   and not yet attached to anything, so we can use the values stored
2998 	 *   in prog->aux
2999 	 *
3000 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3001          *   attached to a target and its initial target was cleared (below)
3002 	 *
3003 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3004 	 *   target_btf_id using the link_create API.
3005 	 *
3006 	 * - if tgt_prog == NULL when this function was called using the old
3007 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3008 	 *
3009 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3010 	 *   was detached and is going for re-attachment.
3011 	 */
3012 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3013 		/*
3014 		 * Allow re-attach for TRACING and LSM programs. If it's
3015 		 * currently linked, bpf_trampoline_link_prog will fail.
3016 		 * EXT programs need to specify tgt_prog_fd, so they
3017 		 * re-attach in separate code path.
3018 		 */
3019 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3020 		    prog->type != BPF_PROG_TYPE_LSM) {
3021 			err = -EINVAL;
3022 			goto out_unlock;
3023 		}
3024 		btf_id = prog->aux->attach_btf_id;
3025 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3026 	}
3027 
3028 	if (!prog->aux->dst_trampoline ||
3029 	    (key && key != prog->aux->dst_trampoline->key)) {
3030 		/* If there is no saved target, or the specified target is
3031 		 * different from the destination specified at load time, we
3032 		 * need a new trampoline and a check for compatibility
3033 		 */
3034 		struct bpf_attach_target_info tgt_info = {};
3035 
3036 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3037 					      &tgt_info);
3038 		if (err)
3039 			goto out_unlock;
3040 
3041 		tr = bpf_trampoline_get(key, &tgt_info);
3042 		if (!tr) {
3043 			err = -ENOMEM;
3044 			goto out_unlock;
3045 		}
3046 	} else {
3047 		/* The caller didn't specify a target, or the target was the
3048 		 * same as the destination supplied during program load. This
3049 		 * means we can reuse the trampoline and reference from program
3050 		 * load time, and there is no need to allocate a new one. This
3051 		 * can only happen once for any program, as the saved values in
3052 		 * prog->aux are cleared below.
3053 		 */
3054 		tr = prog->aux->dst_trampoline;
3055 		tgt_prog = prog->aux->dst_prog;
3056 	}
3057 
3058 	err = bpf_link_prime(&link->link.link, &link_primer);
3059 	if (err)
3060 		goto out_unlock;
3061 
3062 	err = bpf_trampoline_link_prog(&link->link, tr);
3063 	if (err) {
3064 		bpf_link_cleanup(&link_primer);
3065 		link = NULL;
3066 		goto out_unlock;
3067 	}
3068 
3069 	link->tgt_prog = tgt_prog;
3070 	link->trampoline = tr;
3071 
3072 	/* Always clear the trampoline and target prog from prog->aux to make
3073 	 * sure the original attach destination is not kept alive after a
3074 	 * program is (re-)attached to another target.
3075 	 */
3076 	if (prog->aux->dst_prog &&
3077 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3078 		/* got extra prog ref from syscall, or attaching to different prog */
3079 		bpf_prog_put(prog->aux->dst_prog);
3080 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3081 		/* we allocated a new trampoline, so free the old one */
3082 		bpf_trampoline_put(prog->aux->dst_trampoline);
3083 
3084 	prog->aux->dst_prog = NULL;
3085 	prog->aux->dst_trampoline = NULL;
3086 	mutex_unlock(&prog->aux->dst_mutex);
3087 
3088 	return bpf_link_settle(&link_primer);
3089 out_unlock:
3090 	if (tr && tr != prog->aux->dst_trampoline)
3091 		bpf_trampoline_put(tr);
3092 	mutex_unlock(&prog->aux->dst_mutex);
3093 	kfree(link);
3094 out_put_prog:
3095 	if (tgt_prog_fd && tgt_prog)
3096 		bpf_prog_put(tgt_prog);
3097 	return err;
3098 }
3099 
3100 struct bpf_raw_tp_link {
3101 	struct bpf_link link;
3102 	struct bpf_raw_event_map *btp;
3103 };
3104 
bpf_raw_tp_link_release(struct bpf_link * link)3105 static void bpf_raw_tp_link_release(struct bpf_link *link)
3106 {
3107 	struct bpf_raw_tp_link *raw_tp =
3108 		container_of(link, struct bpf_raw_tp_link, link);
3109 
3110 	bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
3111 	bpf_put_raw_tracepoint(raw_tp->btp);
3112 }
3113 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3114 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3115 {
3116 	struct bpf_raw_tp_link *raw_tp =
3117 		container_of(link, struct bpf_raw_tp_link, link);
3118 
3119 	kfree(raw_tp);
3120 }
3121 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3122 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3123 					struct seq_file *seq)
3124 {
3125 	struct bpf_raw_tp_link *raw_tp_link =
3126 		container_of(link, struct bpf_raw_tp_link, link);
3127 
3128 	seq_printf(seq,
3129 		   "tp_name:\t%s\n",
3130 		   raw_tp_link->btp->tp->name);
3131 }
3132 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3133 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3134 					  struct bpf_link_info *info)
3135 {
3136 	struct bpf_raw_tp_link *raw_tp_link =
3137 		container_of(link, struct bpf_raw_tp_link, link);
3138 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3139 	const char *tp_name = raw_tp_link->btp->tp->name;
3140 	u32 ulen = info->raw_tracepoint.tp_name_len;
3141 	size_t tp_len = strlen(tp_name);
3142 
3143 	if (!ulen ^ !ubuf)
3144 		return -EINVAL;
3145 
3146 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3147 
3148 	if (!ubuf)
3149 		return 0;
3150 
3151 	if (ulen >= tp_len + 1) {
3152 		if (copy_to_user(ubuf, tp_name, tp_len + 1))
3153 			return -EFAULT;
3154 	} else {
3155 		char zero = '\0';
3156 
3157 		if (copy_to_user(ubuf, tp_name, ulen - 1))
3158 			return -EFAULT;
3159 		if (put_user(zero, ubuf + ulen - 1))
3160 			return -EFAULT;
3161 		return -ENOSPC;
3162 	}
3163 
3164 	return 0;
3165 }
3166 
3167 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3168 	.release = bpf_raw_tp_link_release,
3169 	.dealloc = bpf_raw_tp_link_dealloc,
3170 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3171 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3172 };
3173 
3174 #ifdef CONFIG_PERF_EVENTS
3175 struct bpf_perf_link {
3176 	struct bpf_link link;
3177 	struct file *perf_file;
3178 };
3179 
bpf_perf_link_release(struct bpf_link * link)3180 static void bpf_perf_link_release(struct bpf_link *link)
3181 {
3182 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3183 	struct perf_event *event = perf_link->perf_file->private_data;
3184 
3185 	perf_event_free_bpf_prog(event);
3186 	fput(perf_link->perf_file);
3187 }
3188 
bpf_perf_link_dealloc(struct bpf_link * link)3189 static void bpf_perf_link_dealloc(struct bpf_link *link)
3190 {
3191 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3192 
3193 	kfree(perf_link);
3194 }
3195 
3196 static const struct bpf_link_ops bpf_perf_link_lops = {
3197 	.release = bpf_perf_link_release,
3198 	.dealloc = bpf_perf_link_dealloc,
3199 };
3200 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3201 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3202 {
3203 	struct bpf_link_primer link_primer;
3204 	struct bpf_perf_link *link;
3205 	struct perf_event *event;
3206 	struct file *perf_file;
3207 	int err;
3208 
3209 	if (attr->link_create.flags)
3210 		return -EINVAL;
3211 
3212 	perf_file = perf_event_get(attr->link_create.target_fd);
3213 	if (IS_ERR(perf_file))
3214 		return PTR_ERR(perf_file);
3215 
3216 	link = kzalloc(sizeof(*link), GFP_USER);
3217 	if (!link) {
3218 		err = -ENOMEM;
3219 		goto out_put_file;
3220 	}
3221 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3222 	link->perf_file = perf_file;
3223 
3224 	err = bpf_link_prime(&link->link, &link_primer);
3225 	if (err) {
3226 		kfree(link);
3227 		goto out_put_file;
3228 	}
3229 
3230 	event = perf_file->private_data;
3231 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3232 	if (err) {
3233 		bpf_link_cleanup(&link_primer);
3234 		goto out_put_file;
3235 	}
3236 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3237 	bpf_prog_inc(prog);
3238 
3239 	return bpf_link_settle(&link_primer);
3240 
3241 out_put_file:
3242 	fput(perf_file);
3243 	return err;
3244 }
3245 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3246 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3247 {
3248 	return -EOPNOTSUPP;
3249 }
3250 #endif /* CONFIG_PERF_EVENTS */
3251 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name)3252 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3253 				  const char __user *user_tp_name)
3254 {
3255 	struct bpf_link_primer link_primer;
3256 	struct bpf_raw_tp_link *link;
3257 	struct bpf_raw_event_map *btp;
3258 	const char *tp_name;
3259 	char buf[128];
3260 	int err;
3261 
3262 	switch (prog->type) {
3263 	case BPF_PROG_TYPE_TRACING:
3264 	case BPF_PROG_TYPE_EXT:
3265 	case BPF_PROG_TYPE_LSM:
3266 		if (user_tp_name)
3267 			/* The attach point for this category of programs
3268 			 * should be specified via btf_id during program load.
3269 			 */
3270 			return -EINVAL;
3271 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3272 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3273 			tp_name = prog->aux->attach_func_name;
3274 			break;
3275 		}
3276 		return bpf_tracing_prog_attach(prog, 0, 0, 0);
3277 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3278 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3279 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3280 			return -EFAULT;
3281 		buf[sizeof(buf) - 1] = 0;
3282 		tp_name = buf;
3283 		break;
3284 	default:
3285 		return -EINVAL;
3286 	}
3287 
3288 	btp = bpf_get_raw_tracepoint(tp_name);
3289 	if (!btp)
3290 		return -ENOENT;
3291 
3292 	link = kzalloc(sizeof(*link), GFP_USER);
3293 	if (!link) {
3294 		err = -ENOMEM;
3295 		goto out_put_btp;
3296 	}
3297 	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3298 		      &bpf_raw_tp_link_lops, prog);
3299 	link->btp = btp;
3300 
3301 	err = bpf_link_prime(&link->link, &link_primer);
3302 	if (err) {
3303 		kfree(link);
3304 		goto out_put_btp;
3305 	}
3306 
3307 	err = bpf_probe_register(link->btp, prog);
3308 	if (err) {
3309 		bpf_link_cleanup(&link_primer);
3310 		goto out_put_btp;
3311 	}
3312 
3313 	return bpf_link_settle(&link_primer);
3314 
3315 out_put_btp:
3316 	bpf_put_raw_tracepoint(btp);
3317 	return err;
3318 }
3319 
3320 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
3321 
bpf_raw_tracepoint_open(const union bpf_attr * attr)3322 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
3323 {
3324 	struct bpf_prog *prog;
3325 	int fd;
3326 
3327 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
3328 		return -EINVAL;
3329 
3330 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
3331 	if (IS_ERR(prog))
3332 		return PTR_ERR(prog);
3333 
3334 	fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name));
3335 	if (fd < 0)
3336 		bpf_prog_put(prog);
3337 	return fd;
3338 }
3339 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)3340 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
3341 					     enum bpf_attach_type attach_type)
3342 {
3343 	switch (prog->type) {
3344 	case BPF_PROG_TYPE_CGROUP_SOCK:
3345 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3346 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3347 	case BPF_PROG_TYPE_SK_LOOKUP:
3348 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
3349 	case BPF_PROG_TYPE_CGROUP_SKB:
3350 		if (!capable(CAP_NET_ADMIN))
3351 			/* cg-skb progs can be loaded by unpriv user.
3352 			 * check permissions at attach time.
3353 			 */
3354 			return -EPERM;
3355 		return prog->enforce_expected_attach_type &&
3356 			prog->expected_attach_type != attach_type ?
3357 			-EINVAL : 0;
3358 	default:
3359 		return 0;
3360 	}
3361 }
3362 
3363 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)3364 attach_type_to_prog_type(enum bpf_attach_type attach_type)
3365 {
3366 	switch (attach_type) {
3367 	case BPF_CGROUP_INET_INGRESS:
3368 	case BPF_CGROUP_INET_EGRESS:
3369 		return BPF_PROG_TYPE_CGROUP_SKB;
3370 	case BPF_CGROUP_INET_SOCK_CREATE:
3371 	case BPF_CGROUP_INET_SOCK_RELEASE:
3372 	case BPF_CGROUP_INET4_POST_BIND:
3373 	case BPF_CGROUP_INET6_POST_BIND:
3374 		return BPF_PROG_TYPE_CGROUP_SOCK;
3375 	case BPF_CGROUP_INET4_BIND:
3376 	case BPF_CGROUP_INET6_BIND:
3377 	case BPF_CGROUP_INET4_CONNECT:
3378 	case BPF_CGROUP_INET6_CONNECT:
3379 	case BPF_CGROUP_INET4_GETPEERNAME:
3380 	case BPF_CGROUP_INET6_GETPEERNAME:
3381 	case BPF_CGROUP_INET4_GETSOCKNAME:
3382 	case BPF_CGROUP_INET6_GETSOCKNAME:
3383 	case BPF_CGROUP_UDP4_SENDMSG:
3384 	case BPF_CGROUP_UDP6_SENDMSG:
3385 	case BPF_CGROUP_UDP4_RECVMSG:
3386 	case BPF_CGROUP_UDP6_RECVMSG:
3387 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
3388 	case BPF_CGROUP_SOCK_OPS:
3389 		return BPF_PROG_TYPE_SOCK_OPS;
3390 	case BPF_CGROUP_DEVICE:
3391 		return BPF_PROG_TYPE_CGROUP_DEVICE;
3392 	case BPF_SK_MSG_VERDICT:
3393 		return BPF_PROG_TYPE_SK_MSG;
3394 	case BPF_SK_SKB_STREAM_PARSER:
3395 	case BPF_SK_SKB_STREAM_VERDICT:
3396 	case BPF_SK_SKB_VERDICT:
3397 		return BPF_PROG_TYPE_SK_SKB;
3398 	case BPF_LIRC_MODE2:
3399 		return BPF_PROG_TYPE_LIRC_MODE2;
3400 	case BPF_FLOW_DISSECTOR:
3401 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
3402 	case BPF_CGROUP_SYSCTL:
3403 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
3404 	case BPF_CGROUP_GETSOCKOPT:
3405 	case BPF_CGROUP_SETSOCKOPT:
3406 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
3407 	case BPF_TRACE_ITER:
3408 	case BPF_TRACE_RAW_TP:
3409 	case BPF_TRACE_FENTRY:
3410 	case BPF_TRACE_FEXIT:
3411 	case BPF_MODIFY_RETURN:
3412 		return BPF_PROG_TYPE_TRACING;
3413 	case BPF_LSM_MAC:
3414 		return BPF_PROG_TYPE_LSM;
3415 	case BPF_SK_LOOKUP:
3416 		return BPF_PROG_TYPE_SK_LOOKUP;
3417 	case BPF_XDP:
3418 		return BPF_PROG_TYPE_XDP;
3419 	default:
3420 		return BPF_PROG_TYPE_UNSPEC;
3421 	}
3422 }
3423 
3424 #define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd
3425 
3426 #define BPF_F_ATTACH_MASK \
3427 	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)
3428 
bpf_prog_attach(const union bpf_attr * attr)3429 static int bpf_prog_attach(const union bpf_attr *attr)
3430 {
3431 	enum bpf_prog_type ptype;
3432 	struct bpf_prog *prog;
3433 	int ret;
3434 
3435 	if (CHECK_ATTR(BPF_PROG_ATTACH))
3436 		return -EINVAL;
3437 
3438 	if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
3439 		return -EINVAL;
3440 
3441 	ptype = attach_type_to_prog_type(attr->attach_type);
3442 	if (ptype == BPF_PROG_TYPE_UNSPEC)
3443 		return -EINVAL;
3444 
3445 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
3446 	if (IS_ERR(prog))
3447 		return PTR_ERR(prog);
3448 
3449 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
3450 		bpf_prog_put(prog);
3451 		return -EINVAL;
3452 	}
3453 
3454 	switch (ptype) {
3455 	case BPF_PROG_TYPE_SK_SKB:
3456 	case BPF_PROG_TYPE_SK_MSG:
3457 		ret = sock_map_get_from_fd(attr, prog);
3458 		break;
3459 	case BPF_PROG_TYPE_LIRC_MODE2:
3460 		ret = lirc_prog_attach(attr, prog);
3461 		break;
3462 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
3463 		ret = netns_bpf_prog_attach(attr, prog);
3464 		break;
3465 	case BPF_PROG_TYPE_CGROUP_DEVICE:
3466 	case BPF_PROG_TYPE_CGROUP_SKB:
3467 	case BPF_PROG_TYPE_CGROUP_SOCK:
3468 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3469 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3470 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
3471 	case BPF_PROG_TYPE_SOCK_OPS:
3472 		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
3473 		break;
3474 	default:
3475 		ret = -EINVAL;
3476 	}
3477 
3478 	if (ret)
3479 		bpf_prog_put(prog);
3480 	return ret;
3481 }
3482 
3483 #define BPF_PROG_DETACH_LAST_FIELD attach_type
3484 
bpf_prog_detach(const union bpf_attr * attr)3485 static int bpf_prog_detach(const union bpf_attr *attr)
3486 {
3487 	enum bpf_prog_type ptype;
3488 
3489 	if (CHECK_ATTR(BPF_PROG_DETACH))
3490 		return -EINVAL;
3491 
3492 	ptype = attach_type_to_prog_type(attr->attach_type);
3493 
3494 	switch (ptype) {
3495 	case BPF_PROG_TYPE_SK_MSG:
3496 	case BPF_PROG_TYPE_SK_SKB:
3497 		return sock_map_prog_detach(attr, ptype);
3498 	case BPF_PROG_TYPE_LIRC_MODE2:
3499 		return lirc_prog_detach(attr);
3500 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
3501 		return netns_bpf_prog_detach(attr, ptype);
3502 	case BPF_PROG_TYPE_CGROUP_DEVICE:
3503 	case BPF_PROG_TYPE_CGROUP_SKB:
3504 	case BPF_PROG_TYPE_CGROUP_SOCK:
3505 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3506 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3507 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
3508 	case BPF_PROG_TYPE_SOCK_OPS:
3509 		return cgroup_bpf_prog_detach(attr, ptype);
3510 	default:
3511 		return -EINVAL;
3512 	}
3513 }
3514 
3515 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
3516 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)3517 static int bpf_prog_query(const union bpf_attr *attr,
3518 			  union bpf_attr __user *uattr)
3519 {
3520 	if (!capable(CAP_NET_ADMIN))
3521 		return -EPERM;
3522 	if (CHECK_ATTR(BPF_PROG_QUERY))
3523 		return -EINVAL;
3524 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
3525 		return -EINVAL;
3526 
3527 	switch (attr->query.attach_type) {
3528 	case BPF_CGROUP_INET_INGRESS:
3529 	case BPF_CGROUP_INET_EGRESS:
3530 	case BPF_CGROUP_INET_SOCK_CREATE:
3531 	case BPF_CGROUP_INET_SOCK_RELEASE:
3532 	case BPF_CGROUP_INET4_BIND:
3533 	case BPF_CGROUP_INET6_BIND:
3534 	case BPF_CGROUP_INET4_POST_BIND:
3535 	case BPF_CGROUP_INET6_POST_BIND:
3536 	case BPF_CGROUP_INET4_CONNECT:
3537 	case BPF_CGROUP_INET6_CONNECT:
3538 	case BPF_CGROUP_INET4_GETPEERNAME:
3539 	case BPF_CGROUP_INET6_GETPEERNAME:
3540 	case BPF_CGROUP_INET4_GETSOCKNAME:
3541 	case BPF_CGROUP_INET6_GETSOCKNAME:
3542 	case BPF_CGROUP_UDP4_SENDMSG:
3543 	case BPF_CGROUP_UDP6_SENDMSG:
3544 	case BPF_CGROUP_UDP4_RECVMSG:
3545 	case BPF_CGROUP_UDP6_RECVMSG:
3546 	case BPF_CGROUP_SOCK_OPS:
3547 	case BPF_CGROUP_DEVICE:
3548 	case BPF_CGROUP_SYSCTL:
3549 	case BPF_CGROUP_GETSOCKOPT:
3550 	case BPF_CGROUP_SETSOCKOPT:
3551 		return cgroup_bpf_prog_query(attr, uattr);
3552 	case BPF_LIRC_MODE2:
3553 		return lirc_prog_query(attr, uattr);
3554 	case BPF_FLOW_DISSECTOR:
3555 	case BPF_SK_LOOKUP:
3556 		return netns_bpf_prog_query(attr, uattr);
3557 	case BPF_SK_SKB_STREAM_PARSER:
3558 	case BPF_SK_SKB_STREAM_VERDICT:
3559 	case BPF_SK_MSG_VERDICT:
3560 	case BPF_SK_SKB_VERDICT:
3561 		return sock_map_bpf_prog_query(attr, uattr);
3562 	default:
3563 		return -EINVAL;
3564 	}
3565 }
3566 
3567 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
3568 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)3569 static int bpf_prog_test_run(const union bpf_attr *attr,
3570 			     union bpf_attr __user *uattr)
3571 {
3572 	struct bpf_prog *prog;
3573 	int ret = -ENOTSUPP;
3574 
3575 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
3576 		return -EINVAL;
3577 
3578 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
3579 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
3580 		return -EINVAL;
3581 
3582 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
3583 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
3584 		return -EINVAL;
3585 
3586 	prog = bpf_prog_get(attr->test.prog_fd);
3587 	if (IS_ERR(prog))
3588 		return PTR_ERR(prog);
3589 
3590 	if (prog->aux->ops->test_run)
3591 		ret = prog->aux->ops->test_run(prog, attr, uattr);
3592 
3593 	bpf_prog_put(prog);
3594 	return ret;
3595 }
3596 
3597 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
3598 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)3599 static int bpf_obj_get_next_id(const union bpf_attr *attr,
3600 			       union bpf_attr __user *uattr,
3601 			       struct idr *idr,
3602 			       spinlock_t *lock)
3603 {
3604 	u32 next_id = attr->start_id;
3605 	int err = 0;
3606 
3607 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
3608 		return -EINVAL;
3609 
3610 	if (!capable(CAP_SYS_ADMIN))
3611 		return -EPERM;
3612 
3613 	next_id++;
3614 	spin_lock_bh(lock);
3615 	if (!idr_get_next(idr, &next_id))
3616 		err = -ENOENT;
3617 	spin_unlock_bh(lock);
3618 
3619 	if (!err)
3620 		err = put_user(next_id, &uattr->next_id);
3621 
3622 	return err;
3623 }
3624 
bpf_map_get_curr_or_next(u32 * id)3625 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
3626 {
3627 	struct bpf_map *map;
3628 
3629 	spin_lock_bh(&map_idr_lock);
3630 again:
3631 	map = idr_get_next(&map_idr, id);
3632 	if (map) {
3633 		map = __bpf_map_inc_not_zero(map, false);
3634 		if (IS_ERR(map)) {
3635 			(*id)++;
3636 			goto again;
3637 		}
3638 	}
3639 	spin_unlock_bh(&map_idr_lock);
3640 
3641 	return map;
3642 }
3643 
bpf_prog_get_curr_or_next(u32 * id)3644 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
3645 {
3646 	struct bpf_prog *prog;
3647 
3648 	spin_lock_bh(&prog_idr_lock);
3649 again:
3650 	prog = idr_get_next(&prog_idr, id);
3651 	if (prog) {
3652 		prog = bpf_prog_inc_not_zero(prog);
3653 		if (IS_ERR(prog)) {
3654 			(*id)++;
3655 			goto again;
3656 		}
3657 	}
3658 	spin_unlock_bh(&prog_idr_lock);
3659 
3660 	return prog;
3661 }
3662 
3663 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
3664 
bpf_prog_by_id(u32 id)3665 struct bpf_prog *bpf_prog_by_id(u32 id)
3666 {
3667 	struct bpf_prog *prog;
3668 
3669 	if (!id)
3670 		return ERR_PTR(-ENOENT);
3671 
3672 	spin_lock_bh(&prog_idr_lock);
3673 	prog = idr_find(&prog_idr, id);
3674 	if (prog)
3675 		prog = bpf_prog_inc_not_zero(prog);
3676 	else
3677 		prog = ERR_PTR(-ENOENT);
3678 	spin_unlock_bh(&prog_idr_lock);
3679 	return prog;
3680 }
3681 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)3682 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
3683 {
3684 	struct bpf_prog *prog;
3685 	u32 id = attr->prog_id;
3686 	int fd;
3687 
3688 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
3689 		return -EINVAL;
3690 
3691 	if (!capable(CAP_SYS_ADMIN))
3692 		return -EPERM;
3693 
3694 	prog = bpf_prog_by_id(id);
3695 	if (IS_ERR(prog))
3696 		return PTR_ERR(prog);
3697 
3698 	fd = bpf_prog_new_fd(prog);
3699 	if (fd < 0)
3700 		bpf_prog_put(prog);
3701 
3702 	return fd;
3703 }
3704 
3705 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
3706 
bpf_map_get_fd_by_id(const union bpf_attr * attr)3707 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
3708 {
3709 	struct bpf_map *map;
3710 	u32 id = attr->map_id;
3711 	int f_flags;
3712 	int fd;
3713 
3714 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
3715 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
3716 		return -EINVAL;
3717 
3718 	if (!capable(CAP_SYS_ADMIN))
3719 		return -EPERM;
3720 
3721 	f_flags = bpf_get_file_flag(attr->open_flags);
3722 	if (f_flags < 0)
3723 		return f_flags;
3724 
3725 	spin_lock_bh(&map_idr_lock);
3726 	map = idr_find(&map_idr, id);
3727 	if (map)
3728 		map = __bpf_map_inc_not_zero(map, true);
3729 	else
3730 		map = ERR_PTR(-ENOENT);
3731 	spin_unlock_bh(&map_idr_lock);
3732 
3733 	if (IS_ERR(map))
3734 		return PTR_ERR(map);
3735 
3736 	fd = bpf_map_new_fd(map, f_flags);
3737 	if (fd < 0)
3738 		bpf_map_put_with_uref(map);
3739 
3740 	return fd;
3741 }
3742 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)3743 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
3744 					      unsigned long addr, u32 *off,
3745 					      u32 *type)
3746 {
3747 	const struct bpf_map *map;
3748 	int i;
3749 
3750 	mutex_lock(&prog->aux->used_maps_mutex);
3751 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
3752 		map = prog->aux->used_maps[i];
3753 		if (map == (void *)addr) {
3754 			*type = BPF_PSEUDO_MAP_FD;
3755 			goto out;
3756 		}
3757 		if (!map->ops->map_direct_value_meta)
3758 			continue;
3759 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
3760 			*type = BPF_PSEUDO_MAP_VALUE;
3761 			goto out;
3762 		}
3763 	}
3764 	map = NULL;
3765 
3766 out:
3767 	mutex_unlock(&prog->aux->used_maps_mutex);
3768 	return map;
3769 }
3770 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)3771 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
3772 					      const struct cred *f_cred)
3773 {
3774 	const struct bpf_map *map;
3775 	struct bpf_insn *insns;
3776 	u32 off, type;
3777 	u64 imm;
3778 	u8 code;
3779 	int i;
3780 
3781 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
3782 			GFP_USER);
3783 	if (!insns)
3784 		return insns;
3785 
3786 	for (i = 0; i < prog->len; i++) {
3787 		code = insns[i].code;
3788 
3789 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
3790 			insns[i].code = BPF_JMP | BPF_CALL;
3791 			insns[i].imm = BPF_FUNC_tail_call;
3792 			/* fall-through */
3793 		}
3794 		if (code == (BPF_JMP | BPF_CALL) ||
3795 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
3796 			if (code == (BPF_JMP | BPF_CALL_ARGS))
3797 				insns[i].code = BPF_JMP | BPF_CALL;
3798 			if (!bpf_dump_raw_ok(f_cred))
3799 				insns[i].imm = 0;
3800 			continue;
3801 		}
3802 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
3803 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
3804 			continue;
3805 		}
3806 
3807 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
3808 			continue;
3809 
3810 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
3811 		map = bpf_map_from_imm(prog, imm, &off, &type);
3812 		if (map) {
3813 			insns[i].src_reg = type;
3814 			insns[i].imm = map->id;
3815 			insns[i + 1].imm = off;
3816 			continue;
3817 		}
3818 	}
3819 
3820 	return insns;
3821 }
3822 
set_info_rec_size(struct bpf_prog_info * info)3823 static int set_info_rec_size(struct bpf_prog_info *info)
3824 {
3825 	/*
3826 	 * Ensure info.*_rec_size is the same as kernel expected size
3827 	 *
3828 	 * or
3829 	 *
3830 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
3831 	 * zero.  In this case, the kernel will set the expected
3832 	 * _rec_size back to the info.
3833 	 */
3834 
3835 	if ((info->nr_func_info || info->func_info_rec_size) &&
3836 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
3837 		return -EINVAL;
3838 
3839 	if ((info->nr_line_info || info->line_info_rec_size) &&
3840 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
3841 		return -EINVAL;
3842 
3843 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
3844 	    info->jited_line_info_rec_size != sizeof(__u64))
3845 		return -EINVAL;
3846 
3847 	info->func_info_rec_size = sizeof(struct bpf_func_info);
3848 	info->line_info_rec_size = sizeof(struct bpf_line_info);
3849 	info->jited_line_info_rec_size = sizeof(__u64);
3850 
3851 	return 0;
3852 }
3853 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)3854 static int bpf_prog_get_info_by_fd(struct file *file,
3855 				   struct bpf_prog *prog,
3856 				   const union bpf_attr *attr,
3857 				   union bpf_attr __user *uattr)
3858 {
3859 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3860 	struct bpf_prog_info info;
3861 	u32 info_len = attr->info.info_len;
3862 	struct bpf_prog_kstats stats;
3863 	char __user *uinsns;
3864 	u32 ulen;
3865 	int err;
3866 
3867 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3868 	if (err)
3869 		return err;
3870 	info_len = min_t(u32, sizeof(info), info_len);
3871 
3872 	memset(&info, 0, sizeof(info));
3873 	if (copy_from_user(&info, uinfo, info_len))
3874 		return -EFAULT;
3875 
3876 	info.type = prog->type;
3877 	info.id = prog->aux->id;
3878 	info.load_time = prog->aux->load_time;
3879 	info.created_by_uid = from_kuid_munged(current_user_ns(),
3880 					       prog->aux->user->uid);
3881 	info.gpl_compatible = prog->gpl_compatible;
3882 
3883 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
3884 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
3885 
3886 	mutex_lock(&prog->aux->used_maps_mutex);
3887 	ulen = info.nr_map_ids;
3888 	info.nr_map_ids = prog->aux->used_map_cnt;
3889 	ulen = min_t(u32, info.nr_map_ids, ulen);
3890 	if (ulen) {
3891 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
3892 		u32 i;
3893 
3894 		for (i = 0; i < ulen; i++)
3895 			if (put_user(prog->aux->used_maps[i]->id,
3896 				     &user_map_ids[i])) {
3897 				mutex_unlock(&prog->aux->used_maps_mutex);
3898 				return -EFAULT;
3899 			}
3900 	}
3901 	mutex_unlock(&prog->aux->used_maps_mutex);
3902 
3903 	err = set_info_rec_size(&info);
3904 	if (err)
3905 		return err;
3906 
3907 	bpf_prog_get_stats(prog, &stats);
3908 	info.run_time_ns = stats.nsecs;
3909 	info.run_cnt = stats.cnt;
3910 	info.recursion_misses = stats.misses;
3911 
3912 	info.verified_insns = prog->aux->verified_insns;
3913 
3914 	if (!bpf_capable()) {
3915 		info.jited_prog_len = 0;
3916 		info.xlated_prog_len = 0;
3917 		info.nr_jited_ksyms = 0;
3918 		info.nr_jited_func_lens = 0;
3919 		info.nr_func_info = 0;
3920 		info.nr_line_info = 0;
3921 		info.nr_jited_line_info = 0;
3922 		goto done;
3923 	}
3924 
3925 	ulen = info.xlated_prog_len;
3926 	info.xlated_prog_len = bpf_prog_insn_size(prog);
3927 	if (info.xlated_prog_len && ulen) {
3928 		struct bpf_insn *insns_sanitized;
3929 		bool fault;
3930 
3931 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
3932 			info.xlated_prog_insns = 0;
3933 			goto done;
3934 		}
3935 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
3936 		if (!insns_sanitized)
3937 			return -ENOMEM;
3938 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
3939 		ulen = min_t(u32, info.xlated_prog_len, ulen);
3940 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
3941 		kfree(insns_sanitized);
3942 		if (fault)
3943 			return -EFAULT;
3944 	}
3945 
3946 	if (bpf_prog_is_dev_bound(prog->aux)) {
3947 		err = bpf_prog_offload_info_fill(&info, prog);
3948 		if (err)
3949 			return err;
3950 		goto done;
3951 	}
3952 
3953 	/* NOTE: the following code is supposed to be skipped for offload.
3954 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
3955 	 * for offload.
3956 	 */
3957 	ulen = info.jited_prog_len;
3958 	if (prog->aux->func_cnt) {
3959 		u32 i;
3960 
3961 		info.jited_prog_len = 0;
3962 		for (i = 0; i < prog->aux->func_cnt; i++)
3963 			info.jited_prog_len += prog->aux->func[i]->jited_len;
3964 	} else {
3965 		info.jited_prog_len = prog->jited_len;
3966 	}
3967 
3968 	if (info.jited_prog_len && ulen) {
3969 		if (bpf_dump_raw_ok(file->f_cred)) {
3970 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
3971 			ulen = min_t(u32, info.jited_prog_len, ulen);
3972 
3973 			/* for multi-function programs, copy the JITed
3974 			 * instructions for all the functions
3975 			 */
3976 			if (prog->aux->func_cnt) {
3977 				u32 len, free, i;
3978 				u8 *img;
3979 
3980 				free = ulen;
3981 				for (i = 0; i < prog->aux->func_cnt; i++) {
3982 					len = prog->aux->func[i]->jited_len;
3983 					len = min_t(u32, len, free);
3984 					img = (u8 *) prog->aux->func[i]->bpf_func;
3985 					if (copy_to_user(uinsns, img, len))
3986 						return -EFAULT;
3987 					uinsns += len;
3988 					free -= len;
3989 					if (!free)
3990 						break;
3991 				}
3992 			} else {
3993 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
3994 					return -EFAULT;
3995 			}
3996 		} else {
3997 			info.jited_prog_insns = 0;
3998 		}
3999 	}
4000 
4001 	ulen = info.nr_jited_ksyms;
4002 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4003 	if (ulen) {
4004 		if (bpf_dump_raw_ok(file->f_cred)) {
4005 			unsigned long ksym_addr;
4006 			u64 __user *user_ksyms;
4007 			u32 i;
4008 
4009 			/* copy the address of the kernel symbol
4010 			 * corresponding to each function
4011 			 */
4012 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4013 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4014 			if (prog->aux->func_cnt) {
4015 				for (i = 0; i < ulen; i++) {
4016 					ksym_addr = (unsigned long)
4017 						prog->aux->func[i]->bpf_func;
4018 					if (put_user((u64) ksym_addr,
4019 						     &user_ksyms[i]))
4020 						return -EFAULT;
4021 				}
4022 			} else {
4023 				ksym_addr = (unsigned long) prog->bpf_func;
4024 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
4025 					return -EFAULT;
4026 			}
4027 		} else {
4028 			info.jited_ksyms = 0;
4029 		}
4030 	}
4031 
4032 	ulen = info.nr_jited_func_lens;
4033 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4034 	if (ulen) {
4035 		if (bpf_dump_raw_ok(file->f_cred)) {
4036 			u32 __user *user_lens;
4037 			u32 func_len, i;
4038 
4039 			/* copy the JITed image lengths for each function */
4040 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4041 			user_lens = u64_to_user_ptr(info.jited_func_lens);
4042 			if (prog->aux->func_cnt) {
4043 				for (i = 0; i < ulen; i++) {
4044 					func_len =
4045 						prog->aux->func[i]->jited_len;
4046 					if (put_user(func_len, &user_lens[i]))
4047 						return -EFAULT;
4048 				}
4049 			} else {
4050 				func_len = prog->jited_len;
4051 				if (put_user(func_len, &user_lens[0]))
4052 					return -EFAULT;
4053 			}
4054 		} else {
4055 			info.jited_func_lens = 0;
4056 		}
4057 	}
4058 
4059 	if (prog->aux->btf)
4060 		info.btf_id = btf_obj_id(prog->aux->btf);
4061 
4062 	ulen = info.nr_func_info;
4063 	info.nr_func_info = prog->aux->func_info_cnt;
4064 	if (info.nr_func_info && ulen) {
4065 		char __user *user_finfo;
4066 
4067 		user_finfo = u64_to_user_ptr(info.func_info);
4068 		ulen = min_t(u32, info.nr_func_info, ulen);
4069 		if (copy_to_user(user_finfo, prog->aux->func_info,
4070 				 info.func_info_rec_size * ulen))
4071 			return -EFAULT;
4072 	}
4073 
4074 	ulen = info.nr_line_info;
4075 	info.nr_line_info = prog->aux->nr_linfo;
4076 	if (info.nr_line_info && ulen) {
4077 		__u8 __user *user_linfo;
4078 
4079 		user_linfo = u64_to_user_ptr(info.line_info);
4080 		ulen = min_t(u32, info.nr_line_info, ulen);
4081 		if (copy_to_user(user_linfo, prog->aux->linfo,
4082 				 info.line_info_rec_size * ulen))
4083 			return -EFAULT;
4084 	}
4085 
4086 	ulen = info.nr_jited_line_info;
4087 	if (prog->aux->jited_linfo)
4088 		info.nr_jited_line_info = prog->aux->nr_linfo;
4089 	else
4090 		info.nr_jited_line_info = 0;
4091 	if (info.nr_jited_line_info && ulen) {
4092 		if (bpf_dump_raw_ok(file->f_cred)) {
4093 			__u64 __user *user_linfo;
4094 			u32 i;
4095 
4096 			user_linfo = u64_to_user_ptr(info.jited_line_info);
4097 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
4098 			for (i = 0; i < ulen; i++) {
4099 				if (put_user((__u64)(long)prog->aux->jited_linfo[i],
4100 					     &user_linfo[i]))
4101 					return -EFAULT;
4102 			}
4103 		} else {
4104 			info.jited_line_info = 0;
4105 		}
4106 	}
4107 
4108 	ulen = info.nr_prog_tags;
4109 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4110 	if (ulen) {
4111 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4112 		u32 i;
4113 
4114 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
4115 		ulen = min_t(u32, info.nr_prog_tags, ulen);
4116 		if (prog->aux->func_cnt) {
4117 			for (i = 0; i < ulen; i++) {
4118 				if (copy_to_user(user_prog_tags[i],
4119 						 prog->aux->func[i]->tag,
4120 						 BPF_TAG_SIZE))
4121 					return -EFAULT;
4122 			}
4123 		} else {
4124 			if (copy_to_user(user_prog_tags[0],
4125 					 prog->tag, BPF_TAG_SIZE))
4126 				return -EFAULT;
4127 		}
4128 	}
4129 
4130 done:
4131 	if (copy_to_user(uinfo, &info, info_len) ||
4132 	    put_user(info_len, &uattr->info.info_len))
4133 		return -EFAULT;
4134 
4135 	return 0;
4136 }
4137 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4138 static int bpf_map_get_info_by_fd(struct file *file,
4139 				  struct bpf_map *map,
4140 				  const union bpf_attr *attr,
4141 				  union bpf_attr __user *uattr)
4142 {
4143 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4144 	struct bpf_map_info info;
4145 	u32 info_len = attr->info.info_len;
4146 	int err;
4147 
4148 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4149 	if (err)
4150 		return err;
4151 	info_len = min_t(u32, sizeof(info), info_len);
4152 
4153 	memset(&info, 0, sizeof(info));
4154 	info.type = map->map_type;
4155 	info.id = map->id;
4156 	info.key_size = map->key_size;
4157 	info.value_size = map->value_size;
4158 	info.max_entries = map->max_entries;
4159 	info.map_flags = map->map_flags;
4160 	info.map_extra = map->map_extra;
4161 	memcpy(info.name, map->name, sizeof(map->name));
4162 
4163 	if (map->btf) {
4164 		info.btf_id = btf_obj_id(map->btf);
4165 		info.btf_key_type_id = map->btf_key_type_id;
4166 		info.btf_value_type_id = map->btf_value_type_id;
4167 	}
4168 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
4169 
4170 	if (bpf_map_is_dev_bound(map)) {
4171 		err = bpf_map_offload_info_fill(&info, map);
4172 		if (err)
4173 			return err;
4174 	}
4175 
4176 	if (copy_to_user(uinfo, &info, info_len) ||
4177 	    put_user(info_len, &uattr->info.info_len))
4178 		return -EFAULT;
4179 
4180 	return 0;
4181 }
4182 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)4183 static int bpf_btf_get_info_by_fd(struct file *file,
4184 				  struct btf *btf,
4185 				  const union bpf_attr *attr,
4186 				  union bpf_attr __user *uattr)
4187 {
4188 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4189 	u32 info_len = attr->info.info_len;
4190 	int err;
4191 
4192 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
4193 	if (err)
4194 		return err;
4195 
4196 	return btf_get_info_by_fd(btf, attr, uattr);
4197 }
4198 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)4199 static int bpf_link_get_info_by_fd(struct file *file,
4200 				  struct bpf_link *link,
4201 				  const union bpf_attr *attr,
4202 				  union bpf_attr __user *uattr)
4203 {
4204 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4205 	struct bpf_link_info info;
4206 	u32 info_len = attr->info.info_len;
4207 	int err;
4208 
4209 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4210 	if (err)
4211 		return err;
4212 	info_len = min_t(u32, sizeof(info), info_len);
4213 
4214 	memset(&info, 0, sizeof(info));
4215 	if (copy_from_user(&info, uinfo, info_len))
4216 		return -EFAULT;
4217 
4218 	info.type = link->type;
4219 	info.id = link->id;
4220 	info.prog_id = link->prog->aux->id;
4221 
4222 	if (link->ops->fill_link_info) {
4223 		err = link->ops->fill_link_info(link, &info);
4224 		if (err)
4225 			return err;
4226 	}
4227 
4228 	if (copy_to_user(uinfo, &info, info_len) ||
4229 	    put_user(info_len, &uattr->info.info_len))
4230 		return -EFAULT;
4231 
4232 	return 0;
4233 }
4234 
4235 
4236 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
4237 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)4238 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
4239 				  union bpf_attr __user *uattr)
4240 {
4241 	int ufd = attr->info.bpf_fd;
4242 	struct fd f;
4243 	int err;
4244 
4245 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
4246 		return -EINVAL;
4247 
4248 	f = fdget(ufd);
4249 	if (!f.file)
4250 		return -EBADFD;
4251 
4252 	if (f.file->f_op == &bpf_prog_fops)
4253 		err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
4254 					      uattr);
4255 	else if (f.file->f_op == &bpf_map_fops)
4256 		err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
4257 					     uattr);
4258 	else if (f.file->f_op == &btf_fops)
4259 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
4260 	else if (f.file->f_op == &bpf_link_fops)
4261 		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
4262 					      attr, uattr);
4263 	else
4264 		err = -EINVAL;
4265 
4266 	fdput(f);
4267 	return err;
4268 }
4269 
4270 #define BPF_BTF_LOAD_LAST_FIELD btf_log_level
4271 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr)4272 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr)
4273 {
4274 	if (CHECK_ATTR(BPF_BTF_LOAD))
4275 		return -EINVAL;
4276 
4277 	if (!bpf_capable())
4278 		return -EPERM;
4279 
4280 	return btf_new_fd(attr, uattr);
4281 }
4282 
4283 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
4284 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)4285 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
4286 {
4287 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
4288 		return -EINVAL;
4289 
4290 	if (!capable(CAP_SYS_ADMIN))
4291 		return -EPERM;
4292 
4293 	return btf_get_fd_by_id(attr->btf_id);
4294 }
4295 
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)4296 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
4297 				    union bpf_attr __user *uattr,
4298 				    u32 prog_id, u32 fd_type,
4299 				    const char *buf, u64 probe_offset,
4300 				    u64 probe_addr)
4301 {
4302 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
4303 	u32 len = buf ? strlen(buf) : 0, input_len;
4304 	int err = 0;
4305 
4306 	if (put_user(len, &uattr->task_fd_query.buf_len))
4307 		return -EFAULT;
4308 	input_len = attr->task_fd_query.buf_len;
4309 	if (input_len && ubuf) {
4310 		if (!len) {
4311 			/* nothing to copy, just make ubuf NULL terminated */
4312 			char zero = '\0';
4313 
4314 			if (put_user(zero, ubuf))
4315 				return -EFAULT;
4316 		} else if (input_len >= len + 1) {
4317 			/* ubuf can hold the string with NULL terminator */
4318 			if (copy_to_user(ubuf, buf, len + 1))
4319 				return -EFAULT;
4320 		} else {
4321 			/* ubuf cannot hold the string with NULL terminator,
4322 			 * do a partial copy with NULL terminator.
4323 			 */
4324 			char zero = '\0';
4325 
4326 			err = -ENOSPC;
4327 			if (copy_to_user(ubuf, buf, input_len - 1))
4328 				return -EFAULT;
4329 			if (put_user(zero, ubuf + input_len - 1))
4330 				return -EFAULT;
4331 		}
4332 	}
4333 
4334 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
4335 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
4336 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
4337 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
4338 		return -EFAULT;
4339 
4340 	return err;
4341 }
4342 
4343 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
4344 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4345 static int bpf_task_fd_query(const union bpf_attr *attr,
4346 			     union bpf_attr __user *uattr)
4347 {
4348 	pid_t pid = attr->task_fd_query.pid;
4349 	u32 fd = attr->task_fd_query.fd;
4350 	const struct perf_event *event;
4351 	struct task_struct *task;
4352 	struct file *file;
4353 	int err;
4354 
4355 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
4356 		return -EINVAL;
4357 
4358 	if (!capable(CAP_SYS_ADMIN))
4359 		return -EPERM;
4360 
4361 	if (attr->task_fd_query.flags != 0)
4362 		return -EINVAL;
4363 
4364 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
4365 	if (!task)
4366 		return -ENOENT;
4367 
4368 	err = 0;
4369 	file = fget_task(task, fd);
4370 	put_task_struct(task);
4371 	if (!file)
4372 		return -EBADF;
4373 
4374 	if (file->f_op == &bpf_link_fops) {
4375 		struct bpf_link *link = file->private_data;
4376 
4377 		if (link->ops == &bpf_raw_tp_link_lops) {
4378 			struct bpf_raw_tp_link *raw_tp =
4379 				container_of(link, struct bpf_raw_tp_link, link);
4380 			struct bpf_raw_event_map *btp = raw_tp->btp;
4381 
4382 			err = bpf_task_fd_query_copy(attr, uattr,
4383 						     raw_tp->link.prog->aux->id,
4384 						     BPF_FD_TYPE_RAW_TRACEPOINT,
4385 						     btp->tp->name, 0, 0);
4386 			goto put_file;
4387 		}
4388 		goto out_not_supp;
4389 	}
4390 
4391 	event = perf_get_event(file);
4392 	if (!IS_ERR(event)) {
4393 		u64 probe_offset, probe_addr;
4394 		u32 prog_id, fd_type;
4395 		const char *buf;
4396 
4397 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
4398 					      &buf, &probe_offset,
4399 					      &probe_addr);
4400 		if (!err)
4401 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
4402 						     fd_type, buf,
4403 						     probe_offset,
4404 						     probe_addr);
4405 		goto put_file;
4406 	}
4407 
4408 out_not_supp:
4409 	err = -ENOTSUPP;
4410 put_file:
4411 	fput(file);
4412 	return err;
4413 }
4414 
4415 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
4416 
4417 #define BPF_DO_BATCH(fn)			\
4418 	do {					\
4419 		if (!fn) {			\
4420 			err = -ENOTSUPP;	\
4421 			goto err_put;		\
4422 		}				\
4423 		err = fn(map, attr, uattr);	\
4424 	} while (0)
4425 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)4426 static int bpf_map_do_batch(const union bpf_attr *attr,
4427 			    union bpf_attr __user *uattr,
4428 			    int cmd)
4429 {
4430 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
4431 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
4432 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
4433 	struct bpf_map *map;
4434 	int err, ufd;
4435 	struct fd f;
4436 
4437 	if (CHECK_ATTR(BPF_MAP_BATCH))
4438 		return -EINVAL;
4439 
4440 	ufd = attr->batch.map_fd;
4441 	f = fdget(ufd);
4442 	map = __bpf_map_get(f);
4443 	if (IS_ERR(map))
4444 		return PTR_ERR(map);
4445 	if (has_write)
4446 		bpf_map_write_active_inc(map);
4447 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
4448 		err = -EPERM;
4449 		goto err_put;
4450 	}
4451 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
4452 		err = -EPERM;
4453 		goto err_put;
4454 	}
4455 
4456 	if (cmd == BPF_MAP_LOOKUP_BATCH)
4457 		BPF_DO_BATCH(map->ops->map_lookup_batch);
4458 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
4459 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch);
4460 	else if (cmd == BPF_MAP_UPDATE_BATCH)
4461 		BPF_DO_BATCH(map->ops->map_update_batch);
4462 	else
4463 		BPF_DO_BATCH(map->ops->map_delete_batch);
4464 err_put:
4465 	if (has_write)
4466 		bpf_map_write_active_dec(map);
4467 	fdput(f);
4468 	return err;
4469 }
4470 
4471 #define BPF_LINK_CREATE_LAST_FIELD link_create.kprobe_multi.cookies
link_create(union bpf_attr * attr,bpfptr_t uattr)4472 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
4473 {
4474 	enum bpf_prog_type ptype;
4475 	struct bpf_prog *prog;
4476 	int ret;
4477 
4478 	if (CHECK_ATTR(BPF_LINK_CREATE))
4479 		return -EINVAL;
4480 
4481 	prog = bpf_prog_get(attr->link_create.prog_fd);
4482 	if (IS_ERR(prog))
4483 		return PTR_ERR(prog);
4484 
4485 	ret = bpf_prog_attach_check_attach_type(prog,
4486 						attr->link_create.attach_type);
4487 	if (ret)
4488 		goto out;
4489 
4490 	switch (prog->type) {
4491 	case BPF_PROG_TYPE_EXT:
4492 		break;
4493 	case BPF_PROG_TYPE_PERF_EVENT:
4494 	case BPF_PROG_TYPE_TRACEPOINT:
4495 		if (attr->link_create.attach_type != BPF_PERF_EVENT) {
4496 			ret = -EINVAL;
4497 			goto out;
4498 		}
4499 		break;
4500 	case BPF_PROG_TYPE_KPROBE:
4501 		if (attr->link_create.attach_type != BPF_PERF_EVENT &&
4502 		    attr->link_create.attach_type != BPF_TRACE_KPROBE_MULTI) {
4503 			ret = -EINVAL;
4504 			goto out;
4505 		}
4506 		break;
4507 	default:
4508 		ptype = attach_type_to_prog_type(attr->link_create.attach_type);
4509 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) {
4510 			ret = -EINVAL;
4511 			goto out;
4512 		}
4513 		break;
4514 	}
4515 
4516 	switch (prog->type) {
4517 	case BPF_PROG_TYPE_CGROUP_SKB:
4518 	case BPF_PROG_TYPE_CGROUP_SOCK:
4519 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4520 	case BPF_PROG_TYPE_SOCK_OPS:
4521 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4522 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4523 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4524 		ret = cgroup_bpf_link_attach(attr, prog);
4525 		break;
4526 	case BPF_PROG_TYPE_EXT:
4527 		ret = bpf_tracing_prog_attach(prog,
4528 					      attr->link_create.target_fd,
4529 					      attr->link_create.target_btf_id,
4530 					      attr->link_create.tracing.cookie);
4531 		break;
4532 	case BPF_PROG_TYPE_LSM:
4533 	case BPF_PROG_TYPE_TRACING:
4534 		if (attr->link_create.attach_type != prog->expected_attach_type) {
4535 			ret = -EINVAL;
4536 			goto out;
4537 		}
4538 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
4539 			ret = bpf_raw_tp_link_attach(prog, NULL);
4540 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
4541 			ret = bpf_iter_link_attach(attr, uattr, prog);
4542 		else
4543 			ret = bpf_tracing_prog_attach(prog,
4544 						      attr->link_create.target_fd,
4545 						      attr->link_create.target_btf_id,
4546 						      attr->link_create.tracing.cookie);
4547 		break;
4548 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4549 	case BPF_PROG_TYPE_SK_LOOKUP:
4550 		ret = netns_bpf_link_create(attr, prog);
4551 		break;
4552 #ifdef CONFIG_NET
4553 	case BPF_PROG_TYPE_XDP:
4554 		ret = bpf_xdp_link_attach(attr, prog);
4555 		break;
4556 #endif
4557 	case BPF_PROG_TYPE_PERF_EVENT:
4558 	case BPF_PROG_TYPE_TRACEPOINT:
4559 		ret = bpf_perf_link_attach(attr, prog);
4560 		break;
4561 	case BPF_PROG_TYPE_KPROBE:
4562 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
4563 			ret = bpf_perf_link_attach(attr, prog);
4564 		else
4565 			ret = bpf_kprobe_multi_link_attach(attr, prog);
4566 		break;
4567 	default:
4568 		ret = -EINVAL;
4569 	}
4570 
4571 out:
4572 	if (ret < 0)
4573 		bpf_prog_put(prog);
4574 	return ret;
4575 }
4576 
4577 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
4578 
link_update(union bpf_attr * attr)4579 static int link_update(union bpf_attr *attr)
4580 {
4581 	struct bpf_prog *old_prog = NULL, *new_prog;
4582 	struct bpf_link *link;
4583 	u32 flags;
4584 	int ret;
4585 
4586 	if (CHECK_ATTR(BPF_LINK_UPDATE))
4587 		return -EINVAL;
4588 
4589 	flags = attr->link_update.flags;
4590 	if (flags & ~BPF_F_REPLACE)
4591 		return -EINVAL;
4592 
4593 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
4594 	if (IS_ERR(link))
4595 		return PTR_ERR(link);
4596 
4597 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
4598 	if (IS_ERR(new_prog)) {
4599 		ret = PTR_ERR(new_prog);
4600 		goto out_put_link;
4601 	}
4602 
4603 	if (flags & BPF_F_REPLACE) {
4604 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
4605 		if (IS_ERR(old_prog)) {
4606 			ret = PTR_ERR(old_prog);
4607 			old_prog = NULL;
4608 			goto out_put_progs;
4609 		}
4610 	} else if (attr->link_update.old_prog_fd) {
4611 		ret = -EINVAL;
4612 		goto out_put_progs;
4613 	}
4614 
4615 	if (link->ops->update_prog)
4616 		ret = link->ops->update_prog(link, new_prog, old_prog);
4617 	else
4618 		ret = -EINVAL;
4619 
4620 out_put_progs:
4621 	if (old_prog)
4622 		bpf_prog_put(old_prog);
4623 	if (ret)
4624 		bpf_prog_put(new_prog);
4625 out_put_link:
4626 	bpf_link_put(link);
4627 	return ret;
4628 }
4629 
4630 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
4631 
link_detach(union bpf_attr * attr)4632 static int link_detach(union bpf_attr *attr)
4633 {
4634 	struct bpf_link *link;
4635 	int ret;
4636 
4637 	if (CHECK_ATTR(BPF_LINK_DETACH))
4638 		return -EINVAL;
4639 
4640 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
4641 	if (IS_ERR(link))
4642 		return PTR_ERR(link);
4643 
4644 	if (link->ops->detach)
4645 		ret = link->ops->detach(link);
4646 	else
4647 		ret = -EOPNOTSUPP;
4648 
4649 	bpf_link_put(link);
4650 	return ret;
4651 }
4652 
bpf_link_inc_not_zero(struct bpf_link * link)4653 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
4654 {
4655 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
4656 }
4657 
bpf_link_by_id(u32 id)4658 struct bpf_link *bpf_link_by_id(u32 id)
4659 {
4660 	struct bpf_link *link;
4661 
4662 	if (!id)
4663 		return ERR_PTR(-ENOENT);
4664 
4665 	spin_lock_bh(&link_idr_lock);
4666 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
4667 	link = idr_find(&link_idr, id);
4668 	if (link) {
4669 		if (link->id)
4670 			link = bpf_link_inc_not_zero(link);
4671 		else
4672 			link = ERR_PTR(-EAGAIN);
4673 	} else {
4674 		link = ERR_PTR(-ENOENT);
4675 	}
4676 	spin_unlock_bh(&link_idr_lock);
4677 	return link;
4678 }
4679 
bpf_link_get_curr_or_next(u32 * id)4680 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
4681 {
4682 	struct bpf_link *link;
4683 
4684 	spin_lock_bh(&link_idr_lock);
4685 again:
4686 	link = idr_get_next(&link_idr, id);
4687 	if (link) {
4688 		link = bpf_link_inc_not_zero(link);
4689 		if (IS_ERR(link)) {
4690 			(*id)++;
4691 			goto again;
4692 		}
4693 	}
4694 	spin_unlock_bh(&link_idr_lock);
4695 
4696 	return link;
4697 }
4698 
4699 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
4700 
bpf_link_get_fd_by_id(const union bpf_attr * attr)4701 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
4702 {
4703 	struct bpf_link *link;
4704 	u32 id = attr->link_id;
4705 	int fd;
4706 
4707 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
4708 		return -EINVAL;
4709 
4710 	if (!capable(CAP_SYS_ADMIN))
4711 		return -EPERM;
4712 
4713 	link = bpf_link_by_id(id);
4714 	if (IS_ERR(link))
4715 		return PTR_ERR(link);
4716 
4717 	fd = bpf_link_new_fd(link);
4718 	if (fd < 0)
4719 		bpf_link_put(link);
4720 
4721 	return fd;
4722 }
4723 
4724 DEFINE_MUTEX(bpf_stats_enabled_mutex);
4725 
bpf_stats_release(struct inode * inode,struct file * file)4726 static int bpf_stats_release(struct inode *inode, struct file *file)
4727 {
4728 	mutex_lock(&bpf_stats_enabled_mutex);
4729 	static_key_slow_dec(&bpf_stats_enabled_key.key);
4730 	mutex_unlock(&bpf_stats_enabled_mutex);
4731 	return 0;
4732 }
4733 
4734 static const struct file_operations bpf_stats_fops = {
4735 	.release = bpf_stats_release,
4736 };
4737 
bpf_enable_runtime_stats(void)4738 static int bpf_enable_runtime_stats(void)
4739 {
4740 	int fd;
4741 
4742 	mutex_lock(&bpf_stats_enabled_mutex);
4743 
4744 	/* Set a very high limit to avoid overflow */
4745 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
4746 		mutex_unlock(&bpf_stats_enabled_mutex);
4747 		return -EBUSY;
4748 	}
4749 
4750 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
4751 	if (fd >= 0)
4752 		static_key_slow_inc(&bpf_stats_enabled_key.key);
4753 
4754 	mutex_unlock(&bpf_stats_enabled_mutex);
4755 	return fd;
4756 }
4757 
4758 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
4759 
bpf_enable_stats(union bpf_attr * attr)4760 static int bpf_enable_stats(union bpf_attr *attr)
4761 {
4762 
4763 	if (CHECK_ATTR(BPF_ENABLE_STATS))
4764 		return -EINVAL;
4765 
4766 	if (!capable(CAP_SYS_ADMIN))
4767 		return -EPERM;
4768 
4769 	switch (attr->enable_stats.type) {
4770 	case BPF_STATS_RUN_TIME:
4771 		return bpf_enable_runtime_stats();
4772 	default:
4773 		break;
4774 	}
4775 	return -EINVAL;
4776 }
4777 
4778 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
4779 
bpf_iter_create(union bpf_attr * attr)4780 static int bpf_iter_create(union bpf_attr *attr)
4781 {
4782 	struct bpf_link *link;
4783 	int err;
4784 
4785 	if (CHECK_ATTR(BPF_ITER_CREATE))
4786 		return -EINVAL;
4787 
4788 	if (attr->iter_create.flags)
4789 		return -EINVAL;
4790 
4791 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
4792 	if (IS_ERR(link))
4793 		return PTR_ERR(link);
4794 
4795 	err = bpf_iter_new_fd(link);
4796 	bpf_link_put(link);
4797 
4798 	return err;
4799 }
4800 
4801 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
4802 
bpf_prog_bind_map(union bpf_attr * attr)4803 static int bpf_prog_bind_map(union bpf_attr *attr)
4804 {
4805 	struct bpf_prog *prog;
4806 	struct bpf_map *map;
4807 	struct bpf_map **used_maps_old, **used_maps_new;
4808 	int i, ret = 0;
4809 
4810 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
4811 		return -EINVAL;
4812 
4813 	if (attr->prog_bind_map.flags)
4814 		return -EINVAL;
4815 
4816 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
4817 	if (IS_ERR(prog))
4818 		return PTR_ERR(prog);
4819 
4820 	map = bpf_map_get(attr->prog_bind_map.map_fd);
4821 	if (IS_ERR(map)) {
4822 		ret = PTR_ERR(map);
4823 		goto out_prog_put;
4824 	}
4825 
4826 	mutex_lock(&prog->aux->used_maps_mutex);
4827 
4828 	used_maps_old = prog->aux->used_maps;
4829 
4830 	for (i = 0; i < prog->aux->used_map_cnt; i++)
4831 		if (used_maps_old[i] == map) {
4832 			bpf_map_put(map);
4833 			goto out_unlock;
4834 		}
4835 
4836 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
4837 				      sizeof(used_maps_new[0]),
4838 				      GFP_KERNEL);
4839 	if (!used_maps_new) {
4840 		ret = -ENOMEM;
4841 		goto out_unlock;
4842 	}
4843 
4844 	memcpy(used_maps_new, used_maps_old,
4845 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
4846 	used_maps_new[prog->aux->used_map_cnt] = map;
4847 
4848 	prog->aux->used_map_cnt++;
4849 	prog->aux->used_maps = used_maps_new;
4850 
4851 	kfree(used_maps_old);
4852 
4853 out_unlock:
4854 	mutex_unlock(&prog->aux->used_maps_mutex);
4855 
4856 	if (ret)
4857 		bpf_map_put(map);
4858 out_prog_put:
4859 	bpf_prog_put(prog);
4860 	return ret;
4861 }
4862 
__sys_bpf(int cmd,bpfptr_t uattr,unsigned int size)4863 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
4864 {
4865 	union bpf_attr attr;
4866 	bool capable;
4867 	int err;
4868 
4869 	capable = bpf_capable() || !sysctl_unprivileged_bpf_disabled;
4870 
4871 	/* Intent here is for unprivileged_bpf_disabled to block key object
4872 	 * creation commands for unprivileged users; other actions depend
4873 	 * of fd availability and access to bpffs, so are dependent on
4874 	 * object creation success.  Capabilities are later verified for
4875 	 * operations such as load and map create, so even with unprivileged
4876 	 * BPF disabled, capability checks are still carried out for these
4877 	 * and other operations.
4878 	 */
4879 	if (!capable &&
4880 	    (cmd == BPF_MAP_CREATE || cmd == BPF_PROG_LOAD))
4881 		return -EPERM;
4882 
4883 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
4884 	if (err)
4885 		return err;
4886 	size = min_t(u32, size, sizeof(attr));
4887 
4888 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
4889 	memset(&attr, 0, sizeof(attr));
4890 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
4891 		return -EFAULT;
4892 
4893 	err = security_bpf(cmd, &attr, size);
4894 	if (err < 0)
4895 		return err;
4896 
4897 	switch (cmd) {
4898 	case BPF_MAP_CREATE:
4899 		err = map_create(&attr);
4900 		break;
4901 	case BPF_MAP_LOOKUP_ELEM:
4902 		err = map_lookup_elem(&attr);
4903 		break;
4904 	case BPF_MAP_UPDATE_ELEM:
4905 		err = map_update_elem(&attr, uattr);
4906 		break;
4907 	case BPF_MAP_DELETE_ELEM:
4908 		err = map_delete_elem(&attr);
4909 		break;
4910 	case BPF_MAP_GET_NEXT_KEY:
4911 		err = map_get_next_key(&attr);
4912 		break;
4913 	case BPF_MAP_FREEZE:
4914 		err = map_freeze(&attr);
4915 		break;
4916 	case BPF_PROG_LOAD:
4917 		err = bpf_prog_load(&attr, uattr);
4918 		break;
4919 	case BPF_OBJ_PIN:
4920 		err = bpf_obj_pin(&attr);
4921 		break;
4922 	case BPF_OBJ_GET:
4923 		err = bpf_obj_get(&attr);
4924 		break;
4925 	case BPF_PROG_ATTACH:
4926 		err = bpf_prog_attach(&attr);
4927 		break;
4928 	case BPF_PROG_DETACH:
4929 		err = bpf_prog_detach(&attr);
4930 		break;
4931 	case BPF_PROG_QUERY:
4932 		err = bpf_prog_query(&attr, uattr.user);
4933 		break;
4934 	case BPF_PROG_TEST_RUN:
4935 		err = bpf_prog_test_run(&attr, uattr.user);
4936 		break;
4937 	case BPF_PROG_GET_NEXT_ID:
4938 		err = bpf_obj_get_next_id(&attr, uattr.user,
4939 					  &prog_idr, &prog_idr_lock);
4940 		break;
4941 	case BPF_MAP_GET_NEXT_ID:
4942 		err = bpf_obj_get_next_id(&attr, uattr.user,
4943 					  &map_idr, &map_idr_lock);
4944 		break;
4945 	case BPF_BTF_GET_NEXT_ID:
4946 		err = bpf_obj_get_next_id(&attr, uattr.user,
4947 					  &btf_idr, &btf_idr_lock);
4948 		break;
4949 	case BPF_PROG_GET_FD_BY_ID:
4950 		err = bpf_prog_get_fd_by_id(&attr);
4951 		break;
4952 	case BPF_MAP_GET_FD_BY_ID:
4953 		err = bpf_map_get_fd_by_id(&attr);
4954 		break;
4955 	case BPF_OBJ_GET_INFO_BY_FD:
4956 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
4957 		break;
4958 	case BPF_RAW_TRACEPOINT_OPEN:
4959 		err = bpf_raw_tracepoint_open(&attr);
4960 		break;
4961 	case BPF_BTF_LOAD:
4962 		err = bpf_btf_load(&attr, uattr);
4963 		break;
4964 	case BPF_BTF_GET_FD_BY_ID:
4965 		err = bpf_btf_get_fd_by_id(&attr);
4966 		break;
4967 	case BPF_TASK_FD_QUERY:
4968 		err = bpf_task_fd_query(&attr, uattr.user);
4969 		break;
4970 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
4971 		err = map_lookup_and_delete_elem(&attr);
4972 		break;
4973 	case BPF_MAP_LOOKUP_BATCH:
4974 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
4975 		break;
4976 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
4977 		err = bpf_map_do_batch(&attr, uattr.user,
4978 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
4979 		break;
4980 	case BPF_MAP_UPDATE_BATCH:
4981 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
4982 		break;
4983 	case BPF_MAP_DELETE_BATCH:
4984 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
4985 		break;
4986 	case BPF_LINK_CREATE:
4987 		err = link_create(&attr, uattr);
4988 		break;
4989 	case BPF_LINK_UPDATE:
4990 		err = link_update(&attr);
4991 		break;
4992 	case BPF_LINK_GET_FD_BY_ID:
4993 		err = bpf_link_get_fd_by_id(&attr);
4994 		break;
4995 	case BPF_LINK_GET_NEXT_ID:
4996 		err = bpf_obj_get_next_id(&attr, uattr.user,
4997 					  &link_idr, &link_idr_lock);
4998 		break;
4999 	case BPF_ENABLE_STATS:
5000 		err = bpf_enable_stats(&attr);
5001 		break;
5002 	case BPF_ITER_CREATE:
5003 		err = bpf_iter_create(&attr);
5004 		break;
5005 	case BPF_LINK_DETACH:
5006 		err = link_detach(&attr);
5007 		break;
5008 	case BPF_PROG_BIND_MAP:
5009 		err = bpf_prog_bind_map(&attr);
5010 		break;
5011 	default:
5012 		err = -EINVAL;
5013 		break;
5014 	}
5015 
5016 	return err;
5017 }
5018 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5019 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5020 {
5021 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5022 }
5023 
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)5024 static bool syscall_prog_is_valid_access(int off, int size,
5025 					 enum bpf_access_type type,
5026 					 const struct bpf_prog *prog,
5027 					 struct bpf_insn_access_aux *info)
5028 {
5029 	if (off < 0 || off >= U16_MAX)
5030 		return false;
5031 	if (off % size != 0)
5032 		return false;
5033 	return true;
5034 }
5035 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5036 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5037 {
5038 	switch (cmd) {
5039 	case BPF_MAP_CREATE:
5040 	case BPF_MAP_UPDATE_ELEM:
5041 	case BPF_MAP_FREEZE:
5042 	case BPF_PROG_LOAD:
5043 	case BPF_BTF_LOAD:
5044 	case BPF_LINK_CREATE:
5045 	case BPF_RAW_TRACEPOINT_OPEN:
5046 		break;
5047 	default:
5048 		return -EINVAL;
5049 	}
5050 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5051 }
5052 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5053 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5054 {
5055 	struct bpf_prog * __maybe_unused prog;
5056 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5057 
5058 	switch (cmd) {
5059 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5060 	case BPF_PROG_TEST_RUN:
5061 		if (attr->test.data_in || attr->test.data_out ||
5062 		    attr->test.ctx_out || attr->test.duration ||
5063 		    attr->test.repeat || attr->test.flags)
5064 			return -EINVAL;
5065 
5066 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5067 		if (IS_ERR(prog))
5068 			return PTR_ERR(prog);
5069 
5070 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
5071 		    attr->test.ctx_size_in > U16_MAX) {
5072 			bpf_prog_put(prog);
5073 			return -EINVAL;
5074 		}
5075 
5076 		run_ctx.bpf_cookie = 0;
5077 		run_ctx.saved_run_ctx = NULL;
5078 		if (!__bpf_prog_enter_sleepable(prog, &run_ctx)) {
5079 			/* recursion detected */
5080 			bpf_prog_put(prog);
5081 			return -EBUSY;
5082 		}
5083 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
5084 		__bpf_prog_exit_sleepable(prog, 0 /* bpf_prog_run does runtime stats */, &run_ctx);
5085 		bpf_prog_put(prog);
5086 		return 0;
5087 #endif
5088 	default:
5089 		return ____bpf_sys_bpf(cmd, attr, size);
5090 	}
5091 }
5092 EXPORT_SYMBOL(kern_sys_bpf);
5093 
5094 static const struct bpf_func_proto bpf_sys_bpf_proto = {
5095 	.func		= bpf_sys_bpf,
5096 	.gpl_only	= false,
5097 	.ret_type	= RET_INTEGER,
5098 	.arg1_type	= ARG_ANYTHING,
5099 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
5100 	.arg3_type	= ARG_CONST_SIZE,
5101 };
5102 
5103 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5104 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5105 {
5106 	return bpf_base_func_proto(func_id);
5107 }
5108 
BPF_CALL_1(bpf_sys_close,u32,fd)5109 BPF_CALL_1(bpf_sys_close, u32, fd)
5110 {
5111 	/* When bpf program calls this helper there should not be
5112 	 * an fdget() without matching completed fdput().
5113 	 * This helper is allowed in the following callchain only:
5114 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
5115 	 */
5116 	return close_fd(fd);
5117 }
5118 
5119 static const struct bpf_func_proto bpf_sys_close_proto = {
5120 	.func		= bpf_sys_close,
5121 	.gpl_only	= false,
5122 	.ret_type	= RET_INTEGER,
5123 	.arg1_type	= ARG_ANYTHING,
5124 };
5125 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)5126 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
5127 {
5128 	if (flags)
5129 		return -EINVAL;
5130 
5131 	if (name_sz <= 1 || name[name_sz - 1])
5132 		return -EINVAL;
5133 
5134 	if (!bpf_dump_raw_ok(current_cred()))
5135 		return -EPERM;
5136 
5137 	*res = kallsyms_lookup_name(name);
5138 	return *res ? 0 : -ENOENT;
5139 }
5140 
5141 const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
5142 	.func		= bpf_kallsyms_lookup_name,
5143 	.gpl_only	= false,
5144 	.ret_type	= RET_INTEGER,
5145 	.arg1_type	= ARG_PTR_TO_MEM,
5146 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
5147 	.arg3_type	= ARG_ANYTHING,
5148 	.arg4_type	= ARG_PTR_TO_LONG,
5149 };
5150 
5151 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5152 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5153 {
5154 	switch (func_id) {
5155 	case BPF_FUNC_sys_bpf:
5156 		return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto;
5157 	case BPF_FUNC_btf_find_by_name_kind:
5158 		return &bpf_btf_find_by_name_kind_proto;
5159 	case BPF_FUNC_sys_close:
5160 		return &bpf_sys_close_proto;
5161 	case BPF_FUNC_kallsyms_lookup_name:
5162 		return &bpf_kallsyms_lookup_name_proto;
5163 	default:
5164 		return tracing_prog_func_proto(func_id, prog);
5165 	}
5166 }
5167 
5168 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
5169 	.get_func_proto  = syscall_prog_func_proto,
5170 	.is_valid_access = syscall_prog_is_valid_access,
5171 };
5172 
5173 const struct bpf_prog_ops bpf_syscall_prog_ops = {
5174 	.test_run = bpf_prog_test_run_syscall,
5175 };
5176 
5177 #ifdef CONFIG_SYSCTL
bpf_stats_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5178 static int bpf_stats_handler(struct ctl_table *table, int write,
5179 			     void *buffer, size_t *lenp, loff_t *ppos)
5180 {
5181 	struct static_key *key = (struct static_key *)table->data;
5182 	static int saved_val;
5183 	int val, ret;
5184 	struct ctl_table tmp = {
5185 		.data   = &val,
5186 		.maxlen = sizeof(val),
5187 		.mode   = table->mode,
5188 		.extra1 = SYSCTL_ZERO,
5189 		.extra2 = SYSCTL_ONE,
5190 	};
5191 
5192 	if (write && !capable(CAP_SYS_ADMIN))
5193 		return -EPERM;
5194 
5195 	mutex_lock(&bpf_stats_enabled_mutex);
5196 	val = saved_val;
5197 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
5198 	if (write && !ret && val != saved_val) {
5199 		if (val)
5200 			static_key_slow_inc(key);
5201 		else
5202 			static_key_slow_dec(key);
5203 		saved_val = val;
5204 	}
5205 	mutex_unlock(&bpf_stats_enabled_mutex);
5206 	return ret;
5207 }
5208 
unpriv_ebpf_notify(int new_state)5209 void __weak unpriv_ebpf_notify(int new_state)
5210 {
5211 }
5212 
bpf_unpriv_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5213 static int bpf_unpriv_handler(struct ctl_table *table, int write,
5214 			      void *buffer, size_t *lenp, loff_t *ppos)
5215 {
5216 	int ret, unpriv_enable = *(int *)table->data;
5217 	bool locked_state = unpriv_enable == 1;
5218 	struct ctl_table tmp = *table;
5219 
5220 	if (write && !capable(CAP_SYS_ADMIN))
5221 		return -EPERM;
5222 
5223 	tmp.data = &unpriv_enable;
5224 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
5225 	if (write && !ret) {
5226 		if (locked_state && unpriv_enable != 1)
5227 			return -EPERM;
5228 		*(int *)table->data = unpriv_enable;
5229 	}
5230 
5231 	unpriv_ebpf_notify(unpriv_enable);
5232 
5233 	return ret;
5234 }
5235 
5236 static struct ctl_table bpf_syscall_table[] = {
5237 	{
5238 		.procname	= "unprivileged_bpf_disabled",
5239 		.data		= &sysctl_unprivileged_bpf_disabled,
5240 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
5241 		.mode		= 0644,
5242 		.proc_handler	= bpf_unpriv_handler,
5243 		.extra1		= SYSCTL_ZERO,
5244 		.extra2		= SYSCTL_TWO,
5245 	},
5246 	{
5247 		.procname	= "bpf_stats_enabled",
5248 		.data		= &bpf_stats_enabled_key.key,
5249 		.maxlen		= sizeof(bpf_stats_enabled_key),
5250 		.mode		= 0644,
5251 		.proc_handler	= bpf_stats_handler,
5252 	},
5253 	{ }
5254 };
5255 
bpf_syscall_sysctl_init(void)5256 static int __init bpf_syscall_sysctl_init(void)
5257 {
5258 	register_sysctl_init("kernel", bpf_syscall_table);
5259 	return 0;
5260 }
5261 late_initcall(bpf_syscall_sysctl_init);
5262 #endif /* CONFIG_SYSCTL */
5263