xref: /openbmc/linux/kernel/bpf/syscall.c (revision d37cf9b63113f13d742713881ce691fc615d8b3b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3  */
4 #include <linux/bpf.h>
5 #include <linux/bpf-cgroup.h>
6 #include <linux/bpf_trace.h>
7 #include <linux/bpf_lirc.h>
8 #include <linux/bpf_verifier.h>
9 #include <linux/bsearch.h>
10 #include <linux/btf.h>
11 #include <linux/syscalls.h>
12 #include <linux/slab.h>
13 #include <linux/sched/signal.h>
14 #include <linux/vmalloc.h>
15 #include <linux/mmzone.h>
16 #include <linux/anon_inodes.h>
17 #include <linux/fdtable.h>
18 #include <linux/file.h>
19 #include <linux/fs.h>
20 #include <linux/license.h>
21 #include <linux/filter.h>
22 #include <linux/kernel.h>
23 #include <linux/idr.h>
24 #include <linux/cred.h>
25 #include <linux/timekeeping.h>
26 #include <linux/ctype.h>
27 #include <linux/nospec.h>
28 #include <linux/audit.h>
29 #include <uapi/linux/btf.h>
30 #include <linux/pgtable.h>
31 #include <linux/bpf_lsm.h>
32 #include <linux/poll.h>
33 #include <linux/sort.h>
34 #include <linux/bpf-netns.h>
35 #include <linux/rcupdate_trace.h>
36 #include <linux/memcontrol.h>
37 #include <linux/trace_events.h>
38 #include <net/netfilter/nf_bpf_link.h>
39 
40 #include <net/tcx.h>
41 
42 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
43 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
44 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
45 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
46 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
47 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
48 			IS_FD_HASH(map))
49 
50 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
51 
52 DEFINE_PER_CPU(int, bpf_prog_active);
53 static DEFINE_IDR(prog_idr);
54 static DEFINE_SPINLOCK(prog_idr_lock);
55 static DEFINE_IDR(map_idr);
56 static DEFINE_SPINLOCK(map_idr_lock);
57 static DEFINE_IDR(link_idr);
58 static DEFINE_SPINLOCK(link_idr_lock);
59 
60 int sysctl_unprivileged_bpf_disabled __read_mostly =
61 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
62 
63 static const struct bpf_map_ops * const bpf_map_types[] = {
64 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
65 #define BPF_MAP_TYPE(_id, _ops) \
66 	[_id] = &_ops,
67 #define BPF_LINK_TYPE(_id, _name)
68 #include <linux/bpf_types.h>
69 #undef BPF_PROG_TYPE
70 #undef BPF_MAP_TYPE
71 #undef BPF_LINK_TYPE
72 };
73 
74 /*
75  * If we're handed a bigger struct than we know of, ensure all the unknown bits
76  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
77  * we don't know about yet.
78  *
79  * There is a ToCToU between this function call and the following
80  * copy_from_user() call. However, this is not a concern since this function is
81  * meant to be a future-proofing of bits.
82  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)83 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
84 			     size_t expected_size,
85 			     size_t actual_size)
86 {
87 	int res;
88 
89 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
90 		return -E2BIG;
91 
92 	if (actual_size <= expected_size)
93 		return 0;
94 
95 	if (uaddr.is_kernel)
96 		res = memchr_inv(uaddr.kernel + expected_size, 0,
97 				 actual_size - expected_size) == NULL;
98 	else
99 		res = check_zeroed_user(uaddr.user + expected_size,
100 					actual_size - expected_size);
101 	if (res < 0)
102 		return res;
103 	return res ? 0 : -E2BIG;
104 }
105 
106 const struct bpf_map_ops bpf_map_offload_ops = {
107 	.map_meta_equal = bpf_map_meta_equal,
108 	.map_alloc = bpf_map_offload_map_alloc,
109 	.map_free = bpf_map_offload_map_free,
110 	.map_check_btf = map_check_no_btf,
111 	.map_mem_usage = bpf_map_offload_map_mem_usage,
112 };
113 
bpf_map_write_active_inc(struct bpf_map * map)114 static void bpf_map_write_active_inc(struct bpf_map *map)
115 {
116 	atomic64_inc(&map->writecnt);
117 }
118 
bpf_map_write_active_dec(struct bpf_map * map)119 static void bpf_map_write_active_dec(struct bpf_map *map)
120 {
121 	atomic64_dec(&map->writecnt);
122 }
123 
bpf_map_write_active(const struct bpf_map * map)124 bool bpf_map_write_active(const struct bpf_map *map)
125 {
126 	return atomic64_read(&map->writecnt) != 0;
127 }
128 
bpf_map_value_size(const struct bpf_map * map)129 static u32 bpf_map_value_size(const struct bpf_map *map)
130 {
131 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
132 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
133 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
134 	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
135 		return round_up(map->value_size, 8) * num_possible_cpus();
136 	else if (IS_FD_MAP(map))
137 		return sizeof(u32);
138 	else
139 		return  map->value_size;
140 }
141 
maybe_wait_bpf_programs(struct bpf_map * map)142 static void maybe_wait_bpf_programs(struct bpf_map *map)
143 {
144 	/* Wait for any running BPF programs to complete so that
145 	 * userspace, when we return to it, knows that all programs
146 	 * that could be running use the new map value.
147 	 */
148 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
149 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
150 		synchronize_rcu();
151 }
152 
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)153 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
154 				void *key, void *value, __u64 flags)
155 {
156 	int err;
157 
158 	/* Need to create a kthread, thus must support schedule */
159 	if (bpf_map_is_offloaded(map)) {
160 		return bpf_map_offload_update_elem(map, key, value, flags);
161 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
162 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
163 		return map->ops->map_update_elem(map, key, value, flags);
164 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
165 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
166 		return sock_map_update_elem_sys(map, key, value, flags);
167 	} else if (IS_FD_PROG_ARRAY(map)) {
168 		return bpf_fd_array_map_update_elem(map, map_file, key, value,
169 						    flags);
170 	}
171 
172 	bpf_disable_instrumentation();
173 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
174 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
175 		err = bpf_percpu_hash_update(map, key, value, flags);
176 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
177 		err = bpf_percpu_array_update(map, key, value, flags);
178 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
179 		err = bpf_percpu_cgroup_storage_update(map, key, value,
180 						       flags);
181 	} else if (IS_FD_ARRAY(map)) {
182 		rcu_read_lock();
183 		err = bpf_fd_array_map_update_elem(map, map_file, key, value,
184 						   flags);
185 		rcu_read_unlock();
186 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
187 		rcu_read_lock();
188 		err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
189 						  flags);
190 		rcu_read_unlock();
191 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
192 		/* rcu_read_lock() is not needed */
193 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
194 							 flags);
195 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
196 		   map->map_type == BPF_MAP_TYPE_STACK ||
197 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
198 		err = map->ops->map_push_elem(map, value, flags);
199 	} else {
200 		rcu_read_lock();
201 		err = map->ops->map_update_elem(map, key, value, flags);
202 		rcu_read_unlock();
203 	}
204 	bpf_enable_instrumentation();
205 	maybe_wait_bpf_programs(map);
206 
207 	return err;
208 }
209 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)210 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
211 			      __u64 flags)
212 {
213 	void *ptr;
214 	int err;
215 
216 	if (bpf_map_is_offloaded(map))
217 		return bpf_map_offload_lookup_elem(map, key, value);
218 
219 	bpf_disable_instrumentation();
220 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
221 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
222 		err = bpf_percpu_hash_copy(map, key, value);
223 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
224 		err = bpf_percpu_array_copy(map, key, value);
225 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
226 		err = bpf_percpu_cgroup_storage_copy(map, key, value);
227 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
228 		err = bpf_stackmap_copy(map, key, value);
229 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
230 		err = bpf_fd_array_map_lookup_elem(map, key, value);
231 	} else if (IS_FD_HASH(map)) {
232 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
233 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
234 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
235 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
236 		   map->map_type == BPF_MAP_TYPE_STACK ||
237 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
238 		err = map->ops->map_peek_elem(map, value);
239 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
240 		/* struct_ops map requires directly updating "value" */
241 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
242 	} else {
243 		rcu_read_lock();
244 		if (map->ops->map_lookup_elem_sys_only)
245 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
246 		else
247 			ptr = map->ops->map_lookup_elem(map, key);
248 		if (IS_ERR(ptr)) {
249 			err = PTR_ERR(ptr);
250 		} else if (!ptr) {
251 			err = -ENOENT;
252 		} else {
253 			err = 0;
254 			if (flags & BPF_F_LOCK)
255 				/* lock 'ptr' and copy everything but lock */
256 				copy_map_value_locked(map, value, ptr, true);
257 			else
258 				copy_map_value(map, value, ptr);
259 			/* mask lock and timer, since value wasn't zero inited */
260 			check_and_init_map_value(map, value);
261 		}
262 		rcu_read_unlock();
263 	}
264 
265 	bpf_enable_instrumentation();
266 	maybe_wait_bpf_programs(map);
267 
268 	return err;
269 }
270 
271 /* Please, do not use this function outside from the map creation path
272  * (e.g. in map update path) without taking care of setting the active
273  * memory cgroup (see at bpf_map_kmalloc_node() for example).
274  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)275 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
276 {
277 	/* We really just want to fail instead of triggering OOM killer
278 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
279 	 * which is used for lower order allocation requests.
280 	 *
281 	 * It has been observed that higher order allocation requests done by
282 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
283 	 * to reclaim memory from the page cache, thus we set
284 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
285 	 */
286 
287 	gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
288 	unsigned int flags = 0;
289 	unsigned long align = 1;
290 	void *area;
291 
292 	if (size >= SIZE_MAX)
293 		return NULL;
294 
295 	/* kmalloc()'ed memory can't be mmap()'ed */
296 	if (mmapable) {
297 		BUG_ON(!PAGE_ALIGNED(size));
298 		align = SHMLBA;
299 		flags = VM_USERMAP;
300 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
301 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
302 				    numa_node);
303 		if (area != NULL)
304 			return area;
305 	}
306 
307 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
308 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
309 			flags, numa_node, __builtin_return_address(0));
310 }
311 
bpf_map_area_alloc(u64 size,int numa_node)312 void *bpf_map_area_alloc(u64 size, int numa_node)
313 {
314 	return __bpf_map_area_alloc(size, numa_node, false);
315 }
316 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)317 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
318 {
319 	return __bpf_map_area_alloc(size, numa_node, true);
320 }
321 
bpf_map_area_free(void * area)322 void bpf_map_area_free(void *area)
323 {
324 	kvfree(area);
325 }
326 
bpf_map_flags_retain_permanent(u32 flags)327 static u32 bpf_map_flags_retain_permanent(u32 flags)
328 {
329 	/* Some map creation flags are not tied to the map object but
330 	 * rather to the map fd instead, so they have no meaning upon
331 	 * map object inspection since multiple file descriptors with
332 	 * different (access) properties can exist here. Thus, given
333 	 * this has zero meaning for the map itself, lets clear these
334 	 * from here.
335 	 */
336 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
337 }
338 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)339 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
340 {
341 	map->map_type = attr->map_type;
342 	map->key_size = attr->key_size;
343 	map->value_size = attr->value_size;
344 	map->max_entries = attr->max_entries;
345 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
346 	map->numa_node = bpf_map_attr_numa_node(attr);
347 	map->map_extra = attr->map_extra;
348 }
349 
bpf_map_alloc_id(struct bpf_map * map)350 static int bpf_map_alloc_id(struct bpf_map *map)
351 {
352 	int id;
353 
354 	idr_preload(GFP_KERNEL);
355 	spin_lock_bh(&map_idr_lock);
356 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
357 	if (id > 0)
358 		map->id = id;
359 	spin_unlock_bh(&map_idr_lock);
360 	idr_preload_end();
361 
362 	if (WARN_ON_ONCE(!id))
363 		return -ENOSPC;
364 
365 	return id > 0 ? 0 : id;
366 }
367 
bpf_map_free_id(struct bpf_map * map)368 void bpf_map_free_id(struct bpf_map *map)
369 {
370 	unsigned long flags;
371 
372 	/* Offloaded maps are removed from the IDR store when their device
373 	 * disappears - even if someone holds an fd to them they are unusable,
374 	 * the memory is gone, all ops will fail; they are simply waiting for
375 	 * refcnt to drop to be freed.
376 	 */
377 	if (!map->id)
378 		return;
379 
380 	spin_lock_irqsave(&map_idr_lock, flags);
381 
382 	idr_remove(&map_idr, map->id);
383 	map->id = 0;
384 
385 	spin_unlock_irqrestore(&map_idr_lock, flags);
386 }
387 
388 #ifdef CONFIG_MEMCG_KMEM
bpf_map_save_memcg(struct bpf_map * map)389 static void bpf_map_save_memcg(struct bpf_map *map)
390 {
391 	/* Currently if a map is created by a process belonging to the root
392 	 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
393 	 * So we have to check map->objcg for being NULL each time it's
394 	 * being used.
395 	 */
396 	if (memcg_bpf_enabled())
397 		map->objcg = get_obj_cgroup_from_current();
398 }
399 
bpf_map_release_memcg(struct bpf_map * map)400 static void bpf_map_release_memcg(struct bpf_map *map)
401 {
402 	if (map->objcg)
403 		obj_cgroup_put(map->objcg);
404 }
405 
bpf_map_get_memcg(const struct bpf_map * map)406 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
407 {
408 	if (map->objcg)
409 		return get_mem_cgroup_from_objcg(map->objcg);
410 
411 	return root_mem_cgroup;
412 }
413 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)414 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
415 			   int node)
416 {
417 	struct mem_cgroup *memcg, *old_memcg;
418 	void *ptr;
419 
420 	memcg = bpf_map_get_memcg(map);
421 	old_memcg = set_active_memcg(memcg);
422 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
423 	set_active_memcg(old_memcg);
424 	mem_cgroup_put(memcg);
425 
426 	return ptr;
427 }
428 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)429 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
430 {
431 	struct mem_cgroup *memcg, *old_memcg;
432 	void *ptr;
433 
434 	memcg = bpf_map_get_memcg(map);
435 	old_memcg = set_active_memcg(memcg);
436 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
437 	set_active_memcg(old_memcg);
438 	mem_cgroup_put(memcg);
439 
440 	return ptr;
441 }
442 
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)443 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
444 		       gfp_t flags)
445 {
446 	struct mem_cgroup *memcg, *old_memcg;
447 	void *ptr;
448 
449 	memcg = bpf_map_get_memcg(map);
450 	old_memcg = set_active_memcg(memcg);
451 	ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
452 	set_active_memcg(old_memcg);
453 	mem_cgroup_put(memcg);
454 
455 	return ptr;
456 }
457 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)458 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
459 				    size_t align, gfp_t flags)
460 {
461 	struct mem_cgroup *memcg, *old_memcg;
462 	void __percpu *ptr;
463 
464 	memcg = bpf_map_get_memcg(map);
465 	old_memcg = set_active_memcg(memcg);
466 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
467 	set_active_memcg(old_memcg);
468 	mem_cgroup_put(memcg);
469 
470 	return ptr;
471 }
472 
473 #else
bpf_map_save_memcg(struct bpf_map * map)474 static void bpf_map_save_memcg(struct bpf_map *map)
475 {
476 }
477 
bpf_map_release_memcg(struct bpf_map * map)478 static void bpf_map_release_memcg(struct bpf_map *map)
479 {
480 }
481 #endif
482 
btf_field_cmp(const void * a,const void * b)483 static int btf_field_cmp(const void *a, const void *b)
484 {
485 	const struct btf_field *f1 = a, *f2 = b;
486 
487 	if (f1->offset < f2->offset)
488 		return -1;
489 	else if (f1->offset > f2->offset)
490 		return 1;
491 	return 0;
492 }
493 
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)494 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
495 				  u32 field_mask)
496 {
497 	struct btf_field *field;
498 
499 	if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
500 		return NULL;
501 	field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
502 	if (!field || !(field->type & field_mask))
503 		return NULL;
504 	return field;
505 }
506 
btf_record_free(struct btf_record * rec)507 void btf_record_free(struct btf_record *rec)
508 {
509 	int i;
510 
511 	if (IS_ERR_OR_NULL(rec))
512 		return;
513 	for (i = 0; i < rec->cnt; i++) {
514 		switch (rec->fields[i].type) {
515 		case BPF_KPTR_UNREF:
516 		case BPF_KPTR_REF:
517 			if (rec->fields[i].kptr.module)
518 				module_put(rec->fields[i].kptr.module);
519 			btf_put(rec->fields[i].kptr.btf);
520 			break;
521 		case BPF_LIST_HEAD:
522 		case BPF_LIST_NODE:
523 		case BPF_RB_ROOT:
524 		case BPF_RB_NODE:
525 		case BPF_SPIN_LOCK:
526 		case BPF_TIMER:
527 		case BPF_REFCOUNT:
528 			/* Nothing to release */
529 			break;
530 		default:
531 			WARN_ON_ONCE(1);
532 			continue;
533 		}
534 	}
535 	kfree(rec);
536 }
537 
bpf_map_free_record(struct bpf_map * map)538 void bpf_map_free_record(struct bpf_map *map)
539 {
540 	btf_record_free(map->record);
541 	map->record = NULL;
542 }
543 
btf_record_dup(const struct btf_record * rec)544 struct btf_record *btf_record_dup(const struct btf_record *rec)
545 {
546 	const struct btf_field *fields;
547 	struct btf_record *new_rec;
548 	int ret, size, i;
549 
550 	if (IS_ERR_OR_NULL(rec))
551 		return NULL;
552 	size = offsetof(struct btf_record, fields[rec->cnt]);
553 	new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
554 	if (!new_rec)
555 		return ERR_PTR(-ENOMEM);
556 	/* Do a deep copy of the btf_record */
557 	fields = rec->fields;
558 	new_rec->cnt = 0;
559 	for (i = 0; i < rec->cnt; i++) {
560 		switch (fields[i].type) {
561 		case BPF_KPTR_UNREF:
562 		case BPF_KPTR_REF:
563 			btf_get(fields[i].kptr.btf);
564 			if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
565 				ret = -ENXIO;
566 				goto free;
567 			}
568 			break;
569 		case BPF_LIST_HEAD:
570 		case BPF_LIST_NODE:
571 		case BPF_RB_ROOT:
572 		case BPF_RB_NODE:
573 		case BPF_SPIN_LOCK:
574 		case BPF_TIMER:
575 		case BPF_REFCOUNT:
576 			/* Nothing to acquire */
577 			break;
578 		default:
579 			ret = -EFAULT;
580 			WARN_ON_ONCE(1);
581 			goto free;
582 		}
583 		new_rec->cnt++;
584 	}
585 	return new_rec;
586 free:
587 	btf_record_free(new_rec);
588 	return ERR_PTR(ret);
589 }
590 
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)591 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
592 {
593 	bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
594 	int size;
595 
596 	if (!a_has_fields && !b_has_fields)
597 		return true;
598 	if (a_has_fields != b_has_fields)
599 		return false;
600 	if (rec_a->cnt != rec_b->cnt)
601 		return false;
602 	size = offsetof(struct btf_record, fields[rec_a->cnt]);
603 	/* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
604 	 * members are zeroed out. So memcmp is safe to do without worrying
605 	 * about padding/unused fields.
606 	 *
607 	 * While spin_lock, timer, and kptr have no relation to map BTF,
608 	 * list_head metadata is specific to map BTF, the btf and value_rec
609 	 * members in particular. btf is the map BTF, while value_rec points to
610 	 * btf_record in that map BTF.
611 	 *
612 	 * So while by default, we don't rely on the map BTF (which the records
613 	 * were parsed from) matching for both records, which is not backwards
614 	 * compatible, in case list_head is part of it, we implicitly rely on
615 	 * that by way of depending on memcmp succeeding for it.
616 	 */
617 	return !memcmp(rec_a, rec_b, size);
618 }
619 
bpf_obj_free_timer(const struct btf_record * rec,void * obj)620 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
621 {
622 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
623 		return;
624 	bpf_timer_cancel_and_free(obj + rec->timer_off);
625 }
626 
627 extern void __bpf_obj_drop_impl(void *p, const struct btf_record *rec);
628 
bpf_obj_free_fields(const struct btf_record * rec,void * obj)629 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
630 {
631 	const struct btf_field *fields;
632 	int i;
633 
634 	if (IS_ERR_OR_NULL(rec))
635 		return;
636 	fields = rec->fields;
637 	for (i = 0; i < rec->cnt; i++) {
638 		struct btf_struct_meta *pointee_struct_meta;
639 		const struct btf_field *field = &fields[i];
640 		void *field_ptr = obj + field->offset;
641 		void *xchgd_field;
642 
643 		switch (fields[i].type) {
644 		case BPF_SPIN_LOCK:
645 			break;
646 		case BPF_TIMER:
647 			bpf_timer_cancel_and_free(field_ptr);
648 			break;
649 		case BPF_KPTR_UNREF:
650 			WRITE_ONCE(*(u64 *)field_ptr, 0);
651 			break;
652 		case BPF_KPTR_REF:
653 			xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
654 			if (!xchgd_field)
655 				break;
656 
657 			if (!btf_is_kernel(field->kptr.btf)) {
658 				pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
659 									   field->kptr.btf_id);
660 				migrate_disable();
661 				__bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
662 								 pointee_struct_meta->record :
663 								 NULL);
664 				migrate_enable();
665 			} else {
666 				field->kptr.dtor(xchgd_field);
667 			}
668 			break;
669 		case BPF_LIST_HEAD:
670 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
671 				continue;
672 			bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
673 			break;
674 		case BPF_RB_ROOT:
675 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
676 				continue;
677 			bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
678 			break;
679 		case BPF_LIST_NODE:
680 		case BPF_RB_NODE:
681 		case BPF_REFCOUNT:
682 			break;
683 		default:
684 			WARN_ON_ONCE(1);
685 			continue;
686 		}
687 	}
688 }
689 
690 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)691 static void bpf_map_free_deferred(struct work_struct *work)
692 {
693 	struct bpf_map *map = container_of(work, struct bpf_map, work);
694 	struct btf_record *rec = map->record;
695 	struct btf *btf = map->btf;
696 
697 	security_bpf_map_free(map);
698 	bpf_map_release_memcg(map);
699 	/* implementation dependent freeing */
700 	map->ops->map_free(map);
701 	/* Delay freeing of btf_record for maps, as map_free
702 	 * callback usually needs access to them. It is better to do it here
703 	 * than require each callback to do the free itself manually.
704 	 *
705 	 * Note that the btf_record stashed in map->inner_map_meta->record was
706 	 * already freed using the map_free callback for map in map case which
707 	 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
708 	 * template bpf_map struct used during verification.
709 	 */
710 	btf_record_free(rec);
711 	/* Delay freeing of btf for maps, as map_free callback may need
712 	 * struct_meta info which will be freed with btf_put().
713 	 */
714 	btf_put(btf);
715 }
716 
bpf_map_put_uref(struct bpf_map * map)717 static void bpf_map_put_uref(struct bpf_map *map)
718 {
719 	if (atomic64_dec_and_test(&map->usercnt)) {
720 		if (map->ops->map_release_uref)
721 			map->ops->map_release_uref(map);
722 	}
723 }
724 
bpf_map_free_in_work(struct bpf_map * map)725 static void bpf_map_free_in_work(struct bpf_map *map)
726 {
727 	INIT_WORK(&map->work, bpf_map_free_deferred);
728 	/* Avoid spawning kworkers, since they all might contend
729 	 * for the same mutex like slab_mutex.
730 	 */
731 	queue_work(system_unbound_wq, &map->work);
732 }
733 
bpf_map_free_rcu_gp(struct rcu_head * rcu)734 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
735 {
736 	bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
737 }
738 
bpf_map_free_mult_rcu_gp(struct rcu_head * rcu)739 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
740 {
741 	if (rcu_trace_implies_rcu_gp())
742 		bpf_map_free_rcu_gp(rcu);
743 	else
744 		call_rcu(rcu, bpf_map_free_rcu_gp);
745 }
746 
747 /* decrement map refcnt and schedule it for freeing via workqueue
748  * (underlying map implementation ops->map_free() might sleep)
749  */
bpf_map_put(struct bpf_map * map)750 void bpf_map_put(struct bpf_map *map)
751 {
752 	if (atomic64_dec_and_test(&map->refcnt)) {
753 		/* bpf_map_free_id() must be called first */
754 		bpf_map_free_id(map);
755 
756 		WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
757 		if (READ_ONCE(map->free_after_mult_rcu_gp))
758 			call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
759 		else if (READ_ONCE(map->free_after_rcu_gp))
760 			call_rcu(&map->rcu, bpf_map_free_rcu_gp);
761 		else
762 			bpf_map_free_in_work(map);
763 	}
764 }
765 EXPORT_SYMBOL_GPL(bpf_map_put);
766 
bpf_map_put_with_uref(struct bpf_map * map)767 void bpf_map_put_with_uref(struct bpf_map *map)
768 {
769 	bpf_map_put_uref(map);
770 	bpf_map_put(map);
771 }
772 
bpf_map_release(struct inode * inode,struct file * filp)773 static int bpf_map_release(struct inode *inode, struct file *filp)
774 {
775 	struct bpf_map *map = filp->private_data;
776 
777 	if (map->ops->map_release)
778 		map->ops->map_release(map, filp);
779 
780 	bpf_map_put_with_uref(map);
781 	return 0;
782 }
783 
map_get_sys_perms(struct bpf_map * map,struct fd f)784 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
785 {
786 	fmode_t mode = f.file->f_mode;
787 
788 	/* Our file permissions may have been overridden by global
789 	 * map permissions facing syscall side.
790 	 */
791 	if (READ_ONCE(map->frozen))
792 		mode &= ~FMODE_CAN_WRITE;
793 	return mode;
794 }
795 
796 #ifdef CONFIG_PROC_FS
797 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)798 static u64 bpf_map_memory_usage(const struct bpf_map *map)
799 {
800 	return map->ops->map_mem_usage(map);
801 }
802 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)803 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
804 {
805 	struct bpf_map *map = filp->private_data;
806 	u32 type = 0, jited = 0;
807 
808 	if (map_type_contains_progs(map)) {
809 		spin_lock(&map->owner.lock);
810 		type  = map->owner.type;
811 		jited = map->owner.jited;
812 		spin_unlock(&map->owner.lock);
813 	}
814 
815 	seq_printf(m,
816 		   "map_type:\t%u\n"
817 		   "key_size:\t%u\n"
818 		   "value_size:\t%u\n"
819 		   "max_entries:\t%u\n"
820 		   "map_flags:\t%#x\n"
821 		   "map_extra:\t%#llx\n"
822 		   "memlock:\t%llu\n"
823 		   "map_id:\t%u\n"
824 		   "frozen:\t%u\n",
825 		   map->map_type,
826 		   map->key_size,
827 		   map->value_size,
828 		   map->max_entries,
829 		   map->map_flags,
830 		   (unsigned long long)map->map_extra,
831 		   bpf_map_memory_usage(map),
832 		   map->id,
833 		   READ_ONCE(map->frozen));
834 	if (type) {
835 		seq_printf(m, "owner_prog_type:\t%u\n", type);
836 		seq_printf(m, "owner_jited:\t%u\n", jited);
837 	}
838 }
839 #endif
840 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)841 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
842 			      loff_t *ppos)
843 {
844 	/* We need this handler such that alloc_file() enables
845 	 * f_mode with FMODE_CAN_READ.
846 	 */
847 	return -EINVAL;
848 }
849 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)850 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
851 			       size_t siz, loff_t *ppos)
852 {
853 	/* We need this handler such that alloc_file() enables
854 	 * f_mode with FMODE_CAN_WRITE.
855 	 */
856 	return -EINVAL;
857 }
858 
859 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)860 static void bpf_map_mmap_open(struct vm_area_struct *vma)
861 {
862 	struct bpf_map *map = vma->vm_file->private_data;
863 
864 	if (vma->vm_flags & VM_MAYWRITE)
865 		bpf_map_write_active_inc(map);
866 }
867 
868 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)869 static void bpf_map_mmap_close(struct vm_area_struct *vma)
870 {
871 	struct bpf_map *map = vma->vm_file->private_data;
872 
873 	if (vma->vm_flags & VM_MAYWRITE)
874 		bpf_map_write_active_dec(map);
875 }
876 
877 static const struct vm_operations_struct bpf_map_default_vmops = {
878 	.open		= bpf_map_mmap_open,
879 	.close		= bpf_map_mmap_close,
880 };
881 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)882 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
883 {
884 	struct bpf_map *map = filp->private_data;
885 	int err = 0;
886 
887 	if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
888 		return -ENOTSUPP;
889 
890 	if (!(vma->vm_flags & VM_SHARED))
891 		return -EINVAL;
892 
893 	mutex_lock(&map->freeze_mutex);
894 
895 	if (vma->vm_flags & VM_WRITE) {
896 		if (map->frozen) {
897 			err = -EPERM;
898 			goto out;
899 		}
900 		/* map is meant to be read-only, so do not allow mapping as
901 		 * writable, because it's possible to leak a writable page
902 		 * reference and allows user-space to still modify it after
903 		 * freezing, while verifier will assume contents do not change
904 		 */
905 		if (map->map_flags & BPF_F_RDONLY_PROG) {
906 			err = -EACCES;
907 			goto out;
908 		}
909 		bpf_map_write_active_inc(map);
910 	}
911 out:
912 	mutex_unlock(&map->freeze_mutex);
913 	if (err)
914 		return err;
915 
916 	/* set default open/close callbacks */
917 	vma->vm_ops = &bpf_map_default_vmops;
918 	vma->vm_private_data = map;
919 	vm_flags_clear(vma, VM_MAYEXEC);
920 	/* If mapping is read-only, then disallow potentially re-mapping with
921 	 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
922 	 * means that as far as BPF map's memory-mapped VMAs are concerned,
923 	 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
924 	 * both should be set, so we can forget about VM_MAYWRITE and always
925 	 * check just VM_WRITE
926 	 */
927 	if (!(vma->vm_flags & VM_WRITE))
928 		vm_flags_clear(vma, VM_MAYWRITE);
929 
930 	err = map->ops->map_mmap(map, vma);
931 	if (err) {
932 		if (vma->vm_flags & VM_WRITE)
933 			bpf_map_write_active_dec(map);
934 	}
935 
936 	return err;
937 }
938 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)939 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
940 {
941 	struct bpf_map *map = filp->private_data;
942 
943 	if (map->ops->map_poll)
944 		return map->ops->map_poll(map, filp, pts);
945 
946 	return EPOLLERR;
947 }
948 
949 const struct file_operations bpf_map_fops = {
950 #ifdef CONFIG_PROC_FS
951 	.show_fdinfo	= bpf_map_show_fdinfo,
952 #endif
953 	.release	= bpf_map_release,
954 	.read		= bpf_dummy_read,
955 	.write		= bpf_dummy_write,
956 	.mmap		= bpf_map_mmap,
957 	.poll		= bpf_map_poll,
958 };
959 
bpf_map_new_fd(struct bpf_map * map,int flags)960 int bpf_map_new_fd(struct bpf_map *map, int flags)
961 {
962 	int ret;
963 
964 	ret = security_bpf_map(map, OPEN_FMODE(flags));
965 	if (ret < 0)
966 		return ret;
967 
968 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
969 				flags | O_CLOEXEC);
970 }
971 
bpf_get_file_flag(int flags)972 int bpf_get_file_flag(int flags)
973 {
974 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
975 		return -EINVAL;
976 	if (flags & BPF_F_RDONLY)
977 		return O_RDONLY;
978 	if (flags & BPF_F_WRONLY)
979 		return O_WRONLY;
980 	return O_RDWR;
981 }
982 
983 /* helper macro to check that unused fields 'union bpf_attr' are zero */
984 #define CHECK_ATTR(CMD) \
985 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
986 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
987 		   sizeof(*attr) - \
988 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
989 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
990 
991 /* dst and src must have at least "size" number of bytes.
992  * Return strlen on success and < 0 on error.
993  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)994 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
995 {
996 	const char *end = src + size;
997 	const char *orig_src = src;
998 
999 	memset(dst, 0, size);
1000 	/* Copy all isalnum(), '_' and '.' chars. */
1001 	while (src < end && *src) {
1002 		if (!isalnum(*src) &&
1003 		    *src != '_' && *src != '.')
1004 			return -EINVAL;
1005 		*dst++ = *src++;
1006 	}
1007 
1008 	/* No '\0' found in "size" number of bytes */
1009 	if (src == end)
1010 		return -EINVAL;
1011 
1012 	return src - orig_src;
1013 }
1014 
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)1015 int map_check_no_btf(const struct bpf_map *map,
1016 		     const struct btf *btf,
1017 		     const struct btf_type *key_type,
1018 		     const struct btf_type *value_type)
1019 {
1020 	return -ENOTSUPP;
1021 }
1022 
map_check_btf(struct bpf_map * map,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1023 static int map_check_btf(struct bpf_map *map, const struct btf *btf,
1024 			 u32 btf_key_id, u32 btf_value_id)
1025 {
1026 	const struct btf_type *key_type, *value_type;
1027 	u32 key_size, value_size;
1028 	int ret = 0;
1029 
1030 	/* Some maps allow key to be unspecified. */
1031 	if (btf_key_id) {
1032 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1033 		if (!key_type || key_size != map->key_size)
1034 			return -EINVAL;
1035 	} else {
1036 		key_type = btf_type_by_id(btf, 0);
1037 		if (!map->ops->map_check_btf)
1038 			return -EINVAL;
1039 	}
1040 
1041 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1042 	if (!value_type || value_size != map->value_size)
1043 		return -EINVAL;
1044 
1045 	map->record = btf_parse_fields(btf, value_type,
1046 				       BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1047 				       BPF_RB_ROOT | BPF_REFCOUNT,
1048 				       map->value_size);
1049 	if (!IS_ERR_OR_NULL(map->record)) {
1050 		int i;
1051 
1052 		if (!bpf_capable()) {
1053 			ret = -EPERM;
1054 			goto free_map_tab;
1055 		}
1056 		if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1057 			ret = -EACCES;
1058 			goto free_map_tab;
1059 		}
1060 		for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1061 			switch (map->record->field_mask & (1 << i)) {
1062 			case 0:
1063 				continue;
1064 			case BPF_SPIN_LOCK:
1065 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1066 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1067 				    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1068 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1069 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1070 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1071 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1072 					ret = -EOPNOTSUPP;
1073 					goto free_map_tab;
1074 				}
1075 				break;
1076 			case BPF_TIMER:
1077 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1078 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1079 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1080 					ret = -EOPNOTSUPP;
1081 					goto free_map_tab;
1082 				}
1083 				break;
1084 			case BPF_KPTR_UNREF:
1085 			case BPF_KPTR_REF:
1086 			case BPF_REFCOUNT:
1087 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1088 				    map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1089 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1090 				    map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1091 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1092 				    map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1093 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1094 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1095 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1096 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1097 					ret = -EOPNOTSUPP;
1098 					goto free_map_tab;
1099 				}
1100 				break;
1101 			case BPF_LIST_HEAD:
1102 			case BPF_RB_ROOT:
1103 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1104 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1105 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1106 					ret = -EOPNOTSUPP;
1107 					goto free_map_tab;
1108 				}
1109 				break;
1110 			default:
1111 				/* Fail if map_type checks are missing for a field type */
1112 				ret = -EOPNOTSUPP;
1113 				goto free_map_tab;
1114 			}
1115 		}
1116 	}
1117 
1118 	ret = btf_check_and_fixup_fields(btf, map->record);
1119 	if (ret < 0)
1120 		goto free_map_tab;
1121 
1122 	if (map->ops->map_check_btf) {
1123 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1124 		if (ret < 0)
1125 			goto free_map_tab;
1126 	}
1127 
1128 	return ret;
1129 free_map_tab:
1130 	bpf_map_free_record(map);
1131 	return ret;
1132 }
1133 
1134 #define BPF_MAP_CREATE_LAST_FIELD map_extra
1135 /* called via syscall */
map_create(union bpf_attr * attr)1136 static int map_create(union bpf_attr *attr)
1137 {
1138 	const struct bpf_map_ops *ops;
1139 	int numa_node = bpf_map_attr_numa_node(attr);
1140 	u32 map_type = attr->map_type;
1141 	struct bpf_map *map;
1142 	int f_flags;
1143 	int err;
1144 
1145 	err = CHECK_ATTR(BPF_MAP_CREATE);
1146 	if (err)
1147 		return -EINVAL;
1148 
1149 	if (attr->btf_vmlinux_value_type_id) {
1150 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1151 		    attr->btf_key_type_id || attr->btf_value_type_id)
1152 			return -EINVAL;
1153 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1154 		return -EINVAL;
1155 	}
1156 
1157 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1158 	    attr->map_extra != 0)
1159 		return -EINVAL;
1160 
1161 	f_flags = bpf_get_file_flag(attr->map_flags);
1162 	if (f_flags < 0)
1163 		return f_flags;
1164 
1165 	if (numa_node != NUMA_NO_NODE &&
1166 	    ((unsigned int)numa_node >= nr_node_ids ||
1167 	     !node_online(numa_node)))
1168 		return -EINVAL;
1169 
1170 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1171 	map_type = attr->map_type;
1172 	if (map_type >= ARRAY_SIZE(bpf_map_types))
1173 		return -EINVAL;
1174 	map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1175 	ops = bpf_map_types[map_type];
1176 	if (!ops)
1177 		return -EINVAL;
1178 
1179 	if (ops->map_alloc_check) {
1180 		err = ops->map_alloc_check(attr);
1181 		if (err)
1182 			return err;
1183 	}
1184 	if (attr->map_ifindex)
1185 		ops = &bpf_map_offload_ops;
1186 	if (!ops->map_mem_usage)
1187 		return -EINVAL;
1188 
1189 	/* Intent here is for unprivileged_bpf_disabled to block BPF map
1190 	 * creation for unprivileged users; other actions depend
1191 	 * on fd availability and access to bpffs, so are dependent on
1192 	 * object creation success. Even with unprivileged BPF disabled,
1193 	 * capability checks are still carried out.
1194 	 */
1195 	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
1196 		return -EPERM;
1197 
1198 	/* check privileged map type permissions */
1199 	switch (map_type) {
1200 	case BPF_MAP_TYPE_ARRAY:
1201 	case BPF_MAP_TYPE_PERCPU_ARRAY:
1202 	case BPF_MAP_TYPE_PROG_ARRAY:
1203 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1204 	case BPF_MAP_TYPE_CGROUP_ARRAY:
1205 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1206 	case BPF_MAP_TYPE_HASH:
1207 	case BPF_MAP_TYPE_PERCPU_HASH:
1208 	case BPF_MAP_TYPE_HASH_OF_MAPS:
1209 	case BPF_MAP_TYPE_RINGBUF:
1210 	case BPF_MAP_TYPE_USER_RINGBUF:
1211 	case BPF_MAP_TYPE_CGROUP_STORAGE:
1212 	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1213 		/* unprivileged */
1214 		break;
1215 	case BPF_MAP_TYPE_SK_STORAGE:
1216 	case BPF_MAP_TYPE_INODE_STORAGE:
1217 	case BPF_MAP_TYPE_TASK_STORAGE:
1218 	case BPF_MAP_TYPE_CGRP_STORAGE:
1219 	case BPF_MAP_TYPE_BLOOM_FILTER:
1220 	case BPF_MAP_TYPE_LPM_TRIE:
1221 	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1222 	case BPF_MAP_TYPE_STACK_TRACE:
1223 	case BPF_MAP_TYPE_QUEUE:
1224 	case BPF_MAP_TYPE_STACK:
1225 	case BPF_MAP_TYPE_LRU_HASH:
1226 	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1227 	case BPF_MAP_TYPE_STRUCT_OPS:
1228 	case BPF_MAP_TYPE_CPUMAP:
1229 		if (!bpf_capable())
1230 			return -EPERM;
1231 		break;
1232 	case BPF_MAP_TYPE_SOCKMAP:
1233 	case BPF_MAP_TYPE_SOCKHASH:
1234 	case BPF_MAP_TYPE_DEVMAP:
1235 	case BPF_MAP_TYPE_DEVMAP_HASH:
1236 	case BPF_MAP_TYPE_XSKMAP:
1237 		if (!capable(CAP_NET_ADMIN))
1238 			return -EPERM;
1239 		break;
1240 	default:
1241 		WARN(1, "unsupported map type %d", map_type);
1242 		return -EPERM;
1243 	}
1244 
1245 	map = ops->map_alloc(attr);
1246 	if (IS_ERR(map))
1247 		return PTR_ERR(map);
1248 	map->ops = ops;
1249 	map->map_type = map_type;
1250 
1251 	err = bpf_obj_name_cpy(map->name, attr->map_name,
1252 			       sizeof(attr->map_name));
1253 	if (err < 0)
1254 		goto free_map;
1255 
1256 	atomic64_set(&map->refcnt, 1);
1257 	atomic64_set(&map->usercnt, 1);
1258 	mutex_init(&map->freeze_mutex);
1259 	spin_lock_init(&map->owner.lock);
1260 
1261 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
1262 	    /* Even the map's value is a kernel's struct,
1263 	     * the bpf_prog.o must have BTF to begin with
1264 	     * to figure out the corresponding kernel's
1265 	     * counter part.  Thus, attr->btf_fd has
1266 	     * to be valid also.
1267 	     */
1268 	    attr->btf_vmlinux_value_type_id) {
1269 		struct btf *btf;
1270 
1271 		btf = btf_get_by_fd(attr->btf_fd);
1272 		if (IS_ERR(btf)) {
1273 			err = PTR_ERR(btf);
1274 			goto free_map;
1275 		}
1276 		if (btf_is_kernel(btf)) {
1277 			btf_put(btf);
1278 			err = -EACCES;
1279 			goto free_map;
1280 		}
1281 		map->btf = btf;
1282 
1283 		if (attr->btf_value_type_id) {
1284 			err = map_check_btf(map, btf, attr->btf_key_type_id,
1285 					    attr->btf_value_type_id);
1286 			if (err)
1287 				goto free_map;
1288 		}
1289 
1290 		map->btf_key_type_id = attr->btf_key_type_id;
1291 		map->btf_value_type_id = attr->btf_value_type_id;
1292 		map->btf_vmlinux_value_type_id =
1293 			attr->btf_vmlinux_value_type_id;
1294 	}
1295 
1296 	err = security_bpf_map_alloc(map);
1297 	if (err)
1298 		goto free_map;
1299 
1300 	err = bpf_map_alloc_id(map);
1301 	if (err)
1302 		goto free_map_sec;
1303 
1304 	bpf_map_save_memcg(map);
1305 
1306 	err = bpf_map_new_fd(map, f_flags);
1307 	if (err < 0) {
1308 		/* failed to allocate fd.
1309 		 * bpf_map_put_with_uref() is needed because the above
1310 		 * bpf_map_alloc_id() has published the map
1311 		 * to the userspace and the userspace may
1312 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1313 		 */
1314 		bpf_map_put_with_uref(map);
1315 		return err;
1316 	}
1317 
1318 	return err;
1319 
1320 free_map_sec:
1321 	security_bpf_map_free(map);
1322 free_map:
1323 	btf_put(map->btf);
1324 	map->ops->map_free(map);
1325 	return err;
1326 }
1327 
1328 /* if error is returned, fd is released.
1329  * On success caller should complete fd access with matching fdput()
1330  */
__bpf_map_get(struct fd f)1331 struct bpf_map *__bpf_map_get(struct fd f)
1332 {
1333 	if (!f.file)
1334 		return ERR_PTR(-EBADF);
1335 	if (f.file->f_op != &bpf_map_fops) {
1336 		fdput(f);
1337 		return ERR_PTR(-EINVAL);
1338 	}
1339 
1340 	return f.file->private_data;
1341 }
1342 
bpf_map_inc(struct bpf_map * map)1343 void bpf_map_inc(struct bpf_map *map)
1344 {
1345 	atomic64_inc(&map->refcnt);
1346 }
1347 EXPORT_SYMBOL_GPL(bpf_map_inc);
1348 
bpf_map_inc_with_uref(struct bpf_map * map)1349 void bpf_map_inc_with_uref(struct bpf_map *map)
1350 {
1351 	atomic64_inc(&map->refcnt);
1352 	atomic64_inc(&map->usercnt);
1353 }
1354 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1355 
bpf_map_get(u32 ufd)1356 struct bpf_map *bpf_map_get(u32 ufd)
1357 {
1358 	struct fd f = fdget(ufd);
1359 	struct bpf_map *map;
1360 
1361 	map = __bpf_map_get(f);
1362 	if (IS_ERR(map))
1363 		return map;
1364 
1365 	bpf_map_inc(map);
1366 	fdput(f);
1367 
1368 	return map;
1369 }
1370 EXPORT_SYMBOL(bpf_map_get);
1371 
bpf_map_get_with_uref(u32 ufd)1372 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1373 {
1374 	struct fd f = fdget(ufd);
1375 	struct bpf_map *map;
1376 
1377 	map = __bpf_map_get(f);
1378 	if (IS_ERR(map))
1379 		return map;
1380 
1381 	bpf_map_inc_with_uref(map);
1382 	fdput(f);
1383 
1384 	return map;
1385 }
1386 
1387 /* map_idr_lock should have been held or the map should have been
1388  * protected by rcu read lock.
1389  */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1390 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1391 {
1392 	int refold;
1393 
1394 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1395 	if (!refold)
1396 		return ERR_PTR(-ENOENT);
1397 	if (uref)
1398 		atomic64_inc(&map->usercnt);
1399 
1400 	return map;
1401 }
1402 
bpf_map_inc_not_zero(struct bpf_map * map)1403 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1404 {
1405 	spin_lock_bh(&map_idr_lock);
1406 	map = __bpf_map_inc_not_zero(map, false);
1407 	spin_unlock_bh(&map_idr_lock);
1408 
1409 	return map;
1410 }
1411 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1412 
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1413 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1414 {
1415 	return -ENOTSUPP;
1416 }
1417 
__bpf_copy_key(void __user * ukey,u64 key_size)1418 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1419 {
1420 	if (key_size)
1421 		return vmemdup_user(ukey, key_size);
1422 
1423 	if (ukey)
1424 		return ERR_PTR(-EINVAL);
1425 
1426 	return NULL;
1427 }
1428 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1429 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1430 {
1431 	if (key_size)
1432 		return kvmemdup_bpfptr(ukey, key_size);
1433 
1434 	if (!bpfptr_is_null(ukey))
1435 		return ERR_PTR(-EINVAL);
1436 
1437 	return NULL;
1438 }
1439 
1440 /* last field in 'union bpf_attr' used by this command */
1441 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1442 
map_lookup_elem(union bpf_attr * attr)1443 static int map_lookup_elem(union bpf_attr *attr)
1444 {
1445 	void __user *ukey = u64_to_user_ptr(attr->key);
1446 	void __user *uvalue = u64_to_user_ptr(attr->value);
1447 	int ufd = attr->map_fd;
1448 	struct bpf_map *map;
1449 	void *key, *value;
1450 	u32 value_size;
1451 	struct fd f;
1452 	int err;
1453 
1454 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1455 		return -EINVAL;
1456 
1457 	if (attr->flags & ~BPF_F_LOCK)
1458 		return -EINVAL;
1459 
1460 	f = fdget(ufd);
1461 	map = __bpf_map_get(f);
1462 	if (IS_ERR(map))
1463 		return PTR_ERR(map);
1464 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1465 		err = -EPERM;
1466 		goto err_put;
1467 	}
1468 
1469 	if ((attr->flags & BPF_F_LOCK) &&
1470 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1471 		err = -EINVAL;
1472 		goto err_put;
1473 	}
1474 
1475 	key = __bpf_copy_key(ukey, map->key_size);
1476 	if (IS_ERR(key)) {
1477 		err = PTR_ERR(key);
1478 		goto err_put;
1479 	}
1480 
1481 	value_size = bpf_map_value_size(map);
1482 
1483 	err = -ENOMEM;
1484 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1485 	if (!value)
1486 		goto free_key;
1487 
1488 	if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1489 		if (copy_from_user(value, uvalue, value_size))
1490 			err = -EFAULT;
1491 		else
1492 			err = bpf_map_copy_value(map, key, value, attr->flags);
1493 		goto free_value;
1494 	}
1495 
1496 	err = bpf_map_copy_value(map, key, value, attr->flags);
1497 	if (err)
1498 		goto free_value;
1499 
1500 	err = -EFAULT;
1501 	if (copy_to_user(uvalue, value, value_size) != 0)
1502 		goto free_value;
1503 
1504 	err = 0;
1505 
1506 free_value:
1507 	kvfree(value);
1508 free_key:
1509 	kvfree(key);
1510 err_put:
1511 	fdput(f);
1512 	return err;
1513 }
1514 
1515 
1516 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1517 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1518 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1519 {
1520 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1521 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1522 	int ufd = attr->map_fd;
1523 	struct bpf_map *map;
1524 	void *key, *value;
1525 	u32 value_size;
1526 	struct fd f;
1527 	int err;
1528 
1529 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1530 		return -EINVAL;
1531 
1532 	f = fdget(ufd);
1533 	map = __bpf_map_get(f);
1534 	if (IS_ERR(map))
1535 		return PTR_ERR(map);
1536 	bpf_map_write_active_inc(map);
1537 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1538 		err = -EPERM;
1539 		goto err_put;
1540 	}
1541 
1542 	if ((attr->flags & BPF_F_LOCK) &&
1543 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1544 		err = -EINVAL;
1545 		goto err_put;
1546 	}
1547 
1548 	key = ___bpf_copy_key(ukey, map->key_size);
1549 	if (IS_ERR(key)) {
1550 		err = PTR_ERR(key);
1551 		goto err_put;
1552 	}
1553 
1554 	value_size = bpf_map_value_size(map);
1555 	value = kvmemdup_bpfptr(uvalue, value_size);
1556 	if (IS_ERR(value)) {
1557 		err = PTR_ERR(value);
1558 		goto free_key;
1559 	}
1560 
1561 	err = bpf_map_update_value(map, f.file, key, value, attr->flags);
1562 
1563 	kvfree(value);
1564 free_key:
1565 	kvfree(key);
1566 err_put:
1567 	bpf_map_write_active_dec(map);
1568 	fdput(f);
1569 	return err;
1570 }
1571 
1572 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1573 
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1574 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1575 {
1576 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1577 	int ufd = attr->map_fd;
1578 	struct bpf_map *map;
1579 	struct fd f;
1580 	void *key;
1581 	int err;
1582 
1583 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1584 		return -EINVAL;
1585 
1586 	f = fdget(ufd);
1587 	map = __bpf_map_get(f);
1588 	if (IS_ERR(map))
1589 		return PTR_ERR(map);
1590 	bpf_map_write_active_inc(map);
1591 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1592 		err = -EPERM;
1593 		goto err_put;
1594 	}
1595 
1596 	key = ___bpf_copy_key(ukey, map->key_size);
1597 	if (IS_ERR(key)) {
1598 		err = PTR_ERR(key);
1599 		goto err_put;
1600 	}
1601 
1602 	if (bpf_map_is_offloaded(map)) {
1603 		err = bpf_map_offload_delete_elem(map, key);
1604 		goto out;
1605 	} else if (IS_FD_PROG_ARRAY(map) ||
1606 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1607 		/* These maps require sleepable context */
1608 		err = map->ops->map_delete_elem(map, key);
1609 		goto out;
1610 	}
1611 
1612 	bpf_disable_instrumentation();
1613 	rcu_read_lock();
1614 	err = map->ops->map_delete_elem(map, key);
1615 	rcu_read_unlock();
1616 	bpf_enable_instrumentation();
1617 	maybe_wait_bpf_programs(map);
1618 out:
1619 	kvfree(key);
1620 err_put:
1621 	bpf_map_write_active_dec(map);
1622 	fdput(f);
1623 	return err;
1624 }
1625 
1626 /* last field in 'union bpf_attr' used by this command */
1627 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1628 
map_get_next_key(union bpf_attr * attr)1629 static int map_get_next_key(union bpf_attr *attr)
1630 {
1631 	void __user *ukey = u64_to_user_ptr(attr->key);
1632 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1633 	int ufd = attr->map_fd;
1634 	struct bpf_map *map;
1635 	void *key, *next_key;
1636 	struct fd f;
1637 	int err;
1638 
1639 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1640 		return -EINVAL;
1641 
1642 	f = fdget(ufd);
1643 	map = __bpf_map_get(f);
1644 	if (IS_ERR(map))
1645 		return PTR_ERR(map);
1646 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1647 		err = -EPERM;
1648 		goto err_put;
1649 	}
1650 
1651 	if (ukey) {
1652 		key = __bpf_copy_key(ukey, map->key_size);
1653 		if (IS_ERR(key)) {
1654 			err = PTR_ERR(key);
1655 			goto err_put;
1656 		}
1657 	} else {
1658 		key = NULL;
1659 	}
1660 
1661 	err = -ENOMEM;
1662 	next_key = kvmalloc(map->key_size, GFP_USER);
1663 	if (!next_key)
1664 		goto free_key;
1665 
1666 	if (bpf_map_is_offloaded(map)) {
1667 		err = bpf_map_offload_get_next_key(map, key, next_key);
1668 		goto out;
1669 	}
1670 
1671 	rcu_read_lock();
1672 	err = map->ops->map_get_next_key(map, key, next_key);
1673 	rcu_read_unlock();
1674 out:
1675 	if (err)
1676 		goto free_next_key;
1677 
1678 	err = -EFAULT;
1679 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1680 		goto free_next_key;
1681 
1682 	err = 0;
1683 
1684 free_next_key:
1685 	kvfree(next_key);
1686 free_key:
1687 	kvfree(key);
1688 err_put:
1689 	fdput(f);
1690 	return err;
1691 }
1692 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1693 int generic_map_delete_batch(struct bpf_map *map,
1694 			     const union bpf_attr *attr,
1695 			     union bpf_attr __user *uattr)
1696 {
1697 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1698 	u32 cp, max_count;
1699 	int err = 0;
1700 	void *key;
1701 
1702 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1703 		return -EINVAL;
1704 
1705 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1706 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1707 		return -EINVAL;
1708 	}
1709 
1710 	max_count = attr->batch.count;
1711 	if (!max_count)
1712 		return 0;
1713 
1714 	if (put_user(0, &uattr->batch.count))
1715 		return -EFAULT;
1716 
1717 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1718 	if (!key)
1719 		return -ENOMEM;
1720 
1721 	for (cp = 0; cp < max_count; cp++) {
1722 		err = -EFAULT;
1723 		if (copy_from_user(key, keys + cp * map->key_size,
1724 				   map->key_size))
1725 			break;
1726 
1727 		if (bpf_map_is_offloaded(map)) {
1728 			err = bpf_map_offload_delete_elem(map, key);
1729 			break;
1730 		}
1731 
1732 		bpf_disable_instrumentation();
1733 		rcu_read_lock();
1734 		err = map->ops->map_delete_elem(map, key);
1735 		rcu_read_unlock();
1736 		bpf_enable_instrumentation();
1737 		if (err)
1738 			break;
1739 		cond_resched();
1740 	}
1741 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1742 		err = -EFAULT;
1743 
1744 	kvfree(key);
1745 
1746 	maybe_wait_bpf_programs(map);
1747 	return err;
1748 }
1749 
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1750 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1751 			     const union bpf_attr *attr,
1752 			     union bpf_attr __user *uattr)
1753 {
1754 	void __user *values = u64_to_user_ptr(attr->batch.values);
1755 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1756 	u32 value_size, cp, max_count;
1757 	void *key, *value;
1758 	int err = 0;
1759 
1760 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1761 		return -EINVAL;
1762 
1763 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1764 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1765 		return -EINVAL;
1766 	}
1767 
1768 	value_size = bpf_map_value_size(map);
1769 
1770 	max_count = attr->batch.count;
1771 	if (!max_count)
1772 		return 0;
1773 
1774 	if (put_user(0, &uattr->batch.count))
1775 		return -EFAULT;
1776 
1777 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1778 	if (!key)
1779 		return -ENOMEM;
1780 
1781 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1782 	if (!value) {
1783 		kvfree(key);
1784 		return -ENOMEM;
1785 	}
1786 
1787 	for (cp = 0; cp < max_count; cp++) {
1788 		err = -EFAULT;
1789 		if (copy_from_user(key, keys + cp * map->key_size,
1790 		    map->key_size) ||
1791 		    copy_from_user(value, values + cp * value_size, value_size))
1792 			break;
1793 
1794 		err = bpf_map_update_value(map, map_file, key, value,
1795 					   attr->batch.elem_flags);
1796 
1797 		if (err)
1798 			break;
1799 		cond_resched();
1800 	}
1801 
1802 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1803 		err = -EFAULT;
1804 
1805 	kvfree(value);
1806 	kvfree(key);
1807 	return err;
1808 }
1809 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1810 int generic_map_lookup_batch(struct bpf_map *map,
1811 				    const union bpf_attr *attr,
1812 				    union bpf_attr __user *uattr)
1813 {
1814 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
1815 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1816 	void __user *values = u64_to_user_ptr(attr->batch.values);
1817 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1818 	void *buf, *buf_prevkey, *prev_key, *key, *value;
1819 	u32 value_size, cp, max_count;
1820 	int err;
1821 
1822 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1823 		return -EINVAL;
1824 
1825 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1826 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
1827 		return -EINVAL;
1828 
1829 	value_size = bpf_map_value_size(map);
1830 
1831 	max_count = attr->batch.count;
1832 	if (!max_count)
1833 		return 0;
1834 
1835 	if (put_user(0, &uattr->batch.count))
1836 		return -EFAULT;
1837 
1838 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1839 	if (!buf_prevkey)
1840 		return -ENOMEM;
1841 
1842 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
1843 	if (!buf) {
1844 		kvfree(buf_prevkey);
1845 		return -ENOMEM;
1846 	}
1847 
1848 	err = -EFAULT;
1849 	prev_key = NULL;
1850 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
1851 		goto free_buf;
1852 	key = buf;
1853 	value = key + map->key_size;
1854 	if (ubatch)
1855 		prev_key = buf_prevkey;
1856 
1857 	for (cp = 0; cp < max_count;) {
1858 		rcu_read_lock();
1859 		err = map->ops->map_get_next_key(map, prev_key, key);
1860 		rcu_read_unlock();
1861 		if (err)
1862 			break;
1863 		err = bpf_map_copy_value(map, key, value,
1864 					 attr->batch.elem_flags);
1865 
1866 		if (err == -ENOENT)
1867 			goto next_key;
1868 
1869 		if (err)
1870 			goto free_buf;
1871 
1872 		if (copy_to_user(keys + cp * map->key_size, key,
1873 				 map->key_size)) {
1874 			err = -EFAULT;
1875 			goto free_buf;
1876 		}
1877 		if (copy_to_user(values + cp * value_size, value, value_size)) {
1878 			err = -EFAULT;
1879 			goto free_buf;
1880 		}
1881 
1882 		cp++;
1883 next_key:
1884 		if (!prev_key)
1885 			prev_key = buf_prevkey;
1886 
1887 		swap(prev_key, key);
1888 		cond_resched();
1889 	}
1890 
1891 	if (err == -EFAULT)
1892 		goto free_buf;
1893 
1894 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
1895 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
1896 		err = -EFAULT;
1897 
1898 free_buf:
1899 	kvfree(buf_prevkey);
1900 	kvfree(buf);
1901 	return err;
1902 }
1903 
1904 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
1905 
map_lookup_and_delete_elem(union bpf_attr * attr)1906 static int map_lookup_and_delete_elem(union bpf_attr *attr)
1907 {
1908 	void __user *ukey = u64_to_user_ptr(attr->key);
1909 	void __user *uvalue = u64_to_user_ptr(attr->value);
1910 	int ufd = attr->map_fd;
1911 	struct bpf_map *map;
1912 	void *key, *value;
1913 	u32 value_size;
1914 	struct fd f;
1915 	int err;
1916 
1917 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
1918 		return -EINVAL;
1919 
1920 	if (attr->flags & ~BPF_F_LOCK)
1921 		return -EINVAL;
1922 
1923 	f = fdget(ufd);
1924 	map = __bpf_map_get(f);
1925 	if (IS_ERR(map))
1926 		return PTR_ERR(map);
1927 	bpf_map_write_active_inc(map);
1928 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
1929 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1930 		err = -EPERM;
1931 		goto err_put;
1932 	}
1933 
1934 	if (attr->flags &&
1935 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
1936 	     map->map_type == BPF_MAP_TYPE_STACK)) {
1937 		err = -EINVAL;
1938 		goto err_put;
1939 	}
1940 
1941 	if ((attr->flags & BPF_F_LOCK) &&
1942 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1943 		err = -EINVAL;
1944 		goto err_put;
1945 	}
1946 
1947 	key = __bpf_copy_key(ukey, map->key_size);
1948 	if (IS_ERR(key)) {
1949 		err = PTR_ERR(key);
1950 		goto err_put;
1951 	}
1952 
1953 	value_size = bpf_map_value_size(map);
1954 
1955 	err = -ENOMEM;
1956 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1957 	if (!value)
1958 		goto free_key;
1959 
1960 	err = -ENOTSUPP;
1961 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
1962 	    map->map_type == BPF_MAP_TYPE_STACK) {
1963 		err = map->ops->map_pop_elem(map, value);
1964 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
1965 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
1966 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
1967 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
1968 		if (!bpf_map_is_offloaded(map)) {
1969 			bpf_disable_instrumentation();
1970 			rcu_read_lock();
1971 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
1972 			rcu_read_unlock();
1973 			bpf_enable_instrumentation();
1974 		}
1975 	}
1976 
1977 	if (err)
1978 		goto free_value;
1979 
1980 	if (copy_to_user(uvalue, value, value_size) != 0) {
1981 		err = -EFAULT;
1982 		goto free_value;
1983 	}
1984 
1985 	err = 0;
1986 
1987 free_value:
1988 	kvfree(value);
1989 free_key:
1990 	kvfree(key);
1991 err_put:
1992 	bpf_map_write_active_dec(map);
1993 	fdput(f);
1994 	return err;
1995 }
1996 
1997 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
1998 
map_freeze(const union bpf_attr * attr)1999 static int map_freeze(const union bpf_attr *attr)
2000 {
2001 	int err = 0, ufd = attr->map_fd;
2002 	struct bpf_map *map;
2003 	struct fd f;
2004 
2005 	if (CHECK_ATTR(BPF_MAP_FREEZE))
2006 		return -EINVAL;
2007 
2008 	f = fdget(ufd);
2009 	map = __bpf_map_get(f);
2010 	if (IS_ERR(map))
2011 		return PTR_ERR(map);
2012 
2013 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) {
2014 		fdput(f);
2015 		return -ENOTSUPP;
2016 	}
2017 
2018 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2019 		fdput(f);
2020 		return -EPERM;
2021 	}
2022 
2023 	mutex_lock(&map->freeze_mutex);
2024 	if (bpf_map_write_active(map)) {
2025 		err = -EBUSY;
2026 		goto err_put;
2027 	}
2028 	if (READ_ONCE(map->frozen)) {
2029 		err = -EBUSY;
2030 		goto err_put;
2031 	}
2032 
2033 	WRITE_ONCE(map->frozen, true);
2034 err_put:
2035 	mutex_unlock(&map->freeze_mutex);
2036 	fdput(f);
2037 	return err;
2038 }
2039 
2040 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2041 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2042 	[_id] = & _name ## _prog_ops,
2043 #define BPF_MAP_TYPE(_id, _ops)
2044 #define BPF_LINK_TYPE(_id, _name)
2045 #include <linux/bpf_types.h>
2046 #undef BPF_PROG_TYPE
2047 #undef BPF_MAP_TYPE
2048 #undef BPF_LINK_TYPE
2049 };
2050 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2051 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2052 {
2053 	const struct bpf_prog_ops *ops;
2054 
2055 	if (type >= ARRAY_SIZE(bpf_prog_types))
2056 		return -EINVAL;
2057 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2058 	ops = bpf_prog_types[type];
2059 	if (!ops)
2060 		return -EINVAL;
2061 
2062 	if (!bpf_prog_is_offloaded(prog->aux))
2063 		prog->aux->ops = ops;
2064 	else
2065 		prog->aux->ops = &bpf_offload_prog_ops;
2066 	prog->type = type;
2067 	return 0;
2068 }
2069 
2070 enum bpf_audit {
2071 	BPF_AUDIT_LOAD,
2072 	BPF_AUDIT_UNLOAD,
2073 	BPF_AUDIT_MAX,
2074 };
2075 
2076 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2077 	[BPF_AUDIT_LOAD]   = "LOAD",
2078 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
2079 };
2080 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2081 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2082 {
2083 	struct audit_context *ctx = NULL;
2084 	struct audit_buffer *ab;
2085 
2086 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2087 		return;
2088 	if (audit_enabled == AUDIT_OFF)
2089 		return;
2090 	if (!in_irq() && !irqs_disabled())
2091 		ctx = audit_context();
2092 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2093 	if (unlikely(!ab))
2094 		return;
2095 	audit_log_format(ab, "prog-id=%u op=%s",
2096 			 prog->aux->id, bpf_audit_str[op]);
2097 	audit_log_end(ab);
2098 }
2099 
bpf_prog_alloc_id(struct bpf_prog * prog)2100 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2101 {
2102 	int id;
2103 
2104 	idr_preload(GFP_KERNEL);
2105 	spin_lock_bh(&prog_idr_lock);
2106 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2107 	if (id > 0)
2108 		prog->aux->id = id;
2109 	spin_unlock_bh(&prog_idr_lock);
2110 	idr_preload_end();
2111 
2112 	/* id is in [1, INT_MAX) */
2113 	if (WARN_ON_ONCE(!id))
2114 		return -ENOSPC;
2115 
2116 	return id > 0 ? 0 : id;
2117 }
2118 
bpf_prog_free_id(struct bpf_prog * prog)2119 void bpf_prog_free_id(struct bpf_prog *prog)
2120 {
2121 	unsigned long flags;
2122 
2123 	/* cBPF to eBPF migrations are currently not in the idr store.
2124 	 * Offloaded programs are removed from the store when their device
2125 	 * disappears - even if someone grabs an fd to them they are unusable,
2126 	 * simply waiting for refcnt to drop to be freed.
2127 	 */
2128 	if (!prog->aux->id)
2129 		return;
2130 
2131 	spin_lock_irqsave(&prog_idr_lock, flags);
2132 	idr_remove(&prog_idr, prog->aux->id);
2133 	prog->aux->id = 0;
2134 	spin_unlock_irqrestore(&prog_idr_lock, flags);
2135 }
2136 
__bpf_prog_put_rcu(struct rcu_head * rcu)2137 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2138 {
2139 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2140 
2141 	kvfree(aux->func_info);
2142 	kfree(aux->func_info_aux);
2143 	free_uid(aux->user);
2144 	security_bpf_prog_free(aux);
2145 	bpf_prog_free(aux->prog);
2146 }
2147 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2148 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2149 {
2150 	bpf_prog_kallsyms_del_all(prog);
2151 	btf_put(prog->aux->btf);
2152 	module_put(prog->aux->mod);
2153 	kvfree(prog->aux->jited_linfo);
2154 	kvfree(prog->aux->linfo);
2155 	kfree(prog->aux->kfunc_tab);
2156 	if (prog->aux->attach_btf)
2157 		btf_put(prog->aux->attach_btf);
2158 
2159 	if (deferred) {
2160 		if (prog->aux->sleepable)
2161 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2162 		else
2163 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2164 	} else {
2165 		__bpf_prog_put_rcu(&prog->aux->rcu);
2166 	}
2167 }
2168 
bpf_prog_put_deferred(struct work_struct * work)2169 static void bpf_prog_put_deferred(struct work_struct *work)
2170 {
2171 	struct bpf_prog_aux *aux;
2172 	struct bpf_prog *prog;
2173 
2174 	aux = container_of(work, struct bpf_prog_aux, work);
2175 	prog = aux->prog;
2176 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2177 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2178 	bpf_prog_free_id(prog);
2179 	__bpf_prog_put_noref(prog, true);
2180 }
2181 
__bpf_prog_put(struct bpf_prog * prog)2182 static void __bpf_prog_put(struct bpf_prog *prog)
2183 {
2184 	struct bpf_prog_aux *aux = prog->aux;
2185 
2186 	if (atomic64_dec_and_test(&aux->refcnt)) {
2187 		if (in_irq() || irqs_disabled()) {
2188 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
2189 			schedule_work(&aux->work);
2190 		} else {
2191 			bpf_prog_put_deferred(&aux->work);
2192 		}
2193 	}
2194 }
2195 
bpf_prog_put(struct bpf_prog * prog)2196 void bpf_prog_put(struct bpf_prog *prog)
2197 {
2198 	__bpf_prog_put(prog);
2199 }
2200 EXPORT_SYMBOL_GPL(bpf_prog_put);
2201 
bpf_prog_release(struct inode * inode,struct file * filp)2202 static int bpf_prog_release(struct inode *inode, struct file *filp)
2203 {
2204 	struct bpf_prog *prog = filp->private_data;
2205 
2206 	bpf_prog_put(prog);
2207 	return 0;
2208 }
2209 
2210 struct bpf_prog_kstats {
2211 	u64 nsecs;
2212 	u64 cnt;
2213 	u64 misses;
2214 };
2215 
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2216 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2217 {
2218 	struct bpf_prog_stats *stats;
2219 	unsigned int flags;
2220 
2221 	stats = this_cpu_ptr(prog->stats);
2222 	flags = u64_stats_update_begin_irqsave(&stats->syncp);
2223 	u64_stats_inc(&stats->misses);
2224 	u64_stats_update_end_irqrestore(&stats->syncp, flags);
2225 }
2226 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2227 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2228 			       struct bpf_prog_kstats *stats)
2229 {
2230 	u64 nsecs = 0, cnt = 0, misses = 0;
2231 	int cpu;
2232 
2233 	for_each_possible_cpu(cpu) {
2234 		const struct bpf_prog_stats *st;
2235 		unsigned int start;
2236 		u64 tnsecs, tcnt, tmisses;
2237 
2238 		st = per_cpu_ptr(prog->stats, cpu);
2239 		do {
2240 			start = u64_stats_fetch_begin(&st->syncp);
2241 			tnsecs = u64_stats_read(&st->nsecs);
2242 			tcnt = u64_stats_read(&st->cnt);
2243 			tmisses = u64_stats_read(&st->misses);
2244 		} while (u64_stats_fetch_retry(&st->syncp, start));
2245 		nsecs += tnsecs;
2246 		cnt += tcnt;
2247 		misses += tmisses;
2248 	}
2249 	stats->nsecs = nsecs;
2250 	stats->cnt = cnt;
2251 	stats->misses = misses;
2252 }
2253 
2254 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2255 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2256 {
2257 	const struct bpf_prog *prog = filp->private_data;
2258 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2259 	struct bpf_prog_kstats stats;
2260 
2261 	bpf_prog_get_stats(prog, &stats);
2262 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2263 	seq_printf(m,
2264 		   "prog_type:\t%u\n"
2265 		   "prog_jited:\t%u\n"
2266 		   "prog_tag:\t%s\n"
2267 		   "memlock:\t%llu\n"
2268 		   "prog_id:\t%u\n"
2269 		   "run_time_ns:\t%llu\n"
2270 		   "run_cnt:\t%llu\n"
2271 		   "recursion_misses:\t%llu\n"
2272 		   "verified_insns:\t%u\n",
2273 		   prog->type,
2274 		   prog->jited,
2275 		   prog_tag,
2276 		   prog->pages * 1ULL << PAGE_SHIFT,
2277 		   prog->aux->id,
2278 		   stats.nsecs,
2279 		   stats.cnt,
2280 		   stats.misses,
2281 		   prog->aux->verified_insns);
2282 }
2283 #endif
2284 
2285 const struct file_operations bpf_prog_fops = {
2286 #ifdef CONFIG_PROC_FS
2287 	.show_fdinfo	= bpf_prog_show_fdinfo,
2288 #endif
2289 	.release	= bpf_prog_release,
2290 	.read		= bpf_dummy_read,
2291 	.write		= bpf_dummy_write,
2292 };
2293 
bpf_prog_new_fd(struct bpf_prog * prog)2294 int bpf_prog_new_fd(struct bpf_prog *prog)
2295 {
2296 	int ret;
2297 
2298 	ret = security_bpf_prog(prog);
2299 	if (ret < 0)
2300 		return ret;
2301 
2302 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2303 				O_RDWR | O_CLOEXEC);
2304 }
2305 
____bpf_prog_get(struct fd f)2306 static struct bpf_prog *____bpf_prog_get(struct fd f)
2307 {
2308 	if (!f.file)
2309 		return ERR_PTR(-EBADF);
2310 	if (f.file->f_op != &bpf_prog_fops) {
2311 		fdput(f);
2312 		return ERR_PTR(-EINVAL);
2313 	}
2314 
2315 	return f.file->private_data;
2316 }
2317 
bpf_prog_add(struct bpf_prog * prog,int i)2318 void bpf_prog_add(struct bpf_prog *prog, int i)
2319 {
2320 	atomic64_add(i, &prog->aux->refcnt);
2321 }
2322 EXPORT_SYMBOL_GPL(bpf_prog_add);
2323 
bpf_prog_sub(struct bpf_prog * prog,int i)2324 void bpf_prog_sub(struct bpf_prog *prog, int i)
2325 {
2326 	/* Only to be used for undoing previous bpf_prog_add() in some
2327 	 * error path. We still know that another entity in our call
2328 	 * path holds a reference to the program, thus atomic_sub() can
2329 	 * be safely used in such cases!
2330 	 */
2331 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2332 }
2333 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2334 
bpf_prog_inc(struct bpf_prog * prog)2335 void bpf_prog_inc(struct bpf_prog *prog)
2336 {
2337 	atomic64_inc(&prog->aux->refcnt);
2338 }
2339 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2340 
2341 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2342 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2343 {
2344 	int refold;
2345 
2346 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2347 
2348 	if (!refold)
2349 		return ERR_PTR(-ENOENT);
2350 
2351 	return prog;
2352 }
2353 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2354 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2355 bool bpf_prog_get_ok(struct bpf_prog *prog,
2356 			    enum bpf_prog_type *attach_type, bool attach_drv)
2357 {
2358 	/* not an attachment, just a refcount inc, always allow */
2359 	if (!attach_type)
2360 		return true;
2361 
2362 	if (prog->type != *attach_type)
2363 		return false;
2364 	if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2365 		return false;
2366 
2367 	return true;
2368 }
2369 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2370 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2371 				       bool attach_drv)
2372 {
2373 	struct fd f = fdget(ufd);
2374 	struct bpf_prog *prog;
2375 
2376 	prog = ____bpf_prog_get(f);
2377 	if (IS_ERR(prog))
2378 		return prog;
2379 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
2380 		prog = ERR_PTR(-EINVAL);
2381 		goto out;
2382 	}
2383 
2384 	bpf_prog_inc(prog);
2385 out:
2386 	fdput(f);
2387 	return prog;
2388 }
2389 
bpf_prog_get(u32 ufd)2390 struct bpf_prog *bpf_prog_get(u32 ufd)
2391 {
2392 	return __bpf_prog_get(ufd, NULL, false);
2393 }
2394 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2395 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2396 				       bool attach_drv)
2397 {
2398 	return __bpf_prog_get(ufd, &type, attach_drv);
2399 }
2400 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2401 
2402 /* Initially all BPF programs could be loaded w/o specifying
2403  * expected_attach_type. Later for some of them specifying expected_attach_type
2404  * at load time became required so that program could be validated properly.
2405  * Programs of types that are allowed to be loaded both w/ and w/o (for
2406  * backward compatibility) expected_attach_type, should have the default attach
2407  * type assigned to expected_attach_type for the latter case, so that it can be
2408  * validated later at attach time.
2409  *
2410  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2411  * prog type requires it but has some attach types that have to be backward
2412  * compatible.
2413  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2414 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2415 {
2416 	switch (attr->prog_type) {
2417 	case BPF_PROG_TYPE_CGROUP_SOCK:
2418 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2419 		 * exist so checking for non-zero is the way to go here.
2420 		 */
2421 		if (!attr->expected_attach_type)
2422 			attr->expected_attach_type =
2423 				BPF_CGROUP_INET_SOCK_CREATE;
2424 		break;
2425 	case BPF_PROG_TYPE_SK_REUSEPORT:
2426 		if (!attr->expected_attach_type)
2427 			attr->expected_attach_type =
2428 				BPF_SK_REUSEPORT_SELECT;
2429 		break;
2430 	}
2431 }
2432 
2433 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)2434 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2435 			   enum bpf_attach_type expected_attach_type,
2436 			   struct btf *attach_btf, u32 btf_id,
2437 			   struct bpf_prog *dst_prog)
2438 {
2439 	if (btf_id) {
2440 		if (btf_id > BTF_MAX_TYPE)
2441 			return -EINVAL;
2442 
2443 		if (!attach_btf && !dst_prog)
2444 			return -EINVAL;
2445 
2446 		switch (prog_type) {
2447 		case BPF_PROG_TYPE_TRACING:
2448 		case BPF_PROG_TYPE_LSM:
2449 		case BPF_PROG_TYPE_STRUCT_OPS:
2450 		case BPF_PROG_TYPE_EXT:
2451 			break;
2452 		default:
2453 			return -EINVAL;
2454 		}
2455 	}
2456 
2457 	if (attach_btf && (!btf_id || dst_prog))
2458 		return -EINVAL;
2459 
2460 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2461 	    prog_type != BPF_PROG_TYPE_EXT)
2462 		return -EINVAL;
2463 
2464 	switch (prog_type) {
2465 	case BPF_PROG_TYPE_CGROUP_SOCK:
2466 		switch (expected_attach_type) {
2467 		case BPF_CGROUP_INET_SOCK_CREATE:
2468 		case BPF_CGROUP_INET_SOCK_RELEASE:
2469 		case BPF_CGROUP_INET4_POST_BIND:
2470 		case BPF_CGROUP_INET6_POST_BIND:
2471 			return 0;
2472 		default:
2473 			return -EINVAL;
2474 		}
2475 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2476 		switch (expected_attach_type) {
2477 		case BPF_CGROUP_INET4_BIND:
2478 		case BPF_CGROUP_INET6_BIND:
2479 		case BPF_CGROUP_INET4_CONNECT:
2480 		case BPF_CGROUP_INET6_CONNECT:
2481 		case BPF_CGROUP_INET4_GETPEERNAME:
2482 		case BPF_CGROUP_INET6_GETPEERNAME:
2483 		case BPF_CGROUP_INET4_GETSOCKNAME:
2484 		case BPF_CGROUP_INET6_GETSOCKNAME:
2485 		case BPF_CGROUP_UDP4_SENDMSG:
2486 		case BPF_CGROUP_UDP6_SENDMSG:
2487 		case BPF_CGROUP_UDP4_RECVMSG:
2488 		case BPF_CGROUP_UDP6_RECVMSG:
2489 			return 0;
2490 		default:
2491 			return -EINVAL;
2492 		}
2493 	case BPF_PROG_TYPE_CGROUP_SKB:
2494 		switch (expected_attach_type) {
2495 		case BPF_CGROUP_INET_INGRESS:
2496 		case BPF_CGROUP_INET_EGRESS:
2497 			return 0;
2498 		default:
2499 			return -EINVAL;
2500 		}
2501 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2502 		switch (expected_attach_type) {
2503 		case BPF_CGROUP_SETSOCKOPT:
2504 		case BPF_CGROUP_GETSOCKOPT:
2505 			return 0;
2506 		default:
2507 			return -EINVAL;
2508 		}
2509 	case BPF_PROG_TYPE_SK_LOOKUP:
2510 		if (expected_attach_type == BPF_SK_LOOKUP)
2511 			return 0;
2512 		return -EINVAL;
2513 	case BPF_PROG_TYPE_SK_REUSEPORT:
2514 		switch (expected_attach_type) {
2515 		case BPF_SK_REUSEPORT_SELECT:
2516 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2517 			return 0;
2518 		default:
2519 			return -EINVAL;
2520 		}
2521 	case BPF_PROG_TYPE_NETFILTER:
2522 		if (expected_attach_type == BPF_NETFILTER)
2523 			return 0;
2524 		return -EINVAL;
2525 	case BPF_PROG_TYPE_SYSCALL:
2526 	case BPF_PROG_TYPE_EXT:
2527 		if (expected_attach_type)
2528 			return -EINVAL;
2529 		fallthrough;
2530 	default:
2531 		return 0;
2532 	}
2533 }
2534 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2535 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2536 {
2537 	switch (prog_type) {
2538 	case BPF_PROG_TYPE_SCHED_CLS:
2539 	case BPF_PROG_TYPE_SCHED_ACT:
2540 	case BPF_PROG_TYPE_XDP:
2541 	case BPF_PROG_TYPE_LWT_IN:
2542 	case BPF_PROG_TYPE_LWT_OUT:
2543 	case BPF_PROG_TYPE_LWT_XMIT:
2544 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2545 	case BPF_PROG_TYPE_SK_SKB:
2546 	case BPF_PROG_TYPE_SK_MSG:
2547 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2548 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2549 	case BPF_PROG_TYPE_CGROUP_SOCK:
2550 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2551 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2552 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2553 	case BPF_PROG_TYPE_SOCK_OPS:
2554 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2555 	case BPF_PROG_TYPE_NETFILTER:
2556 		return true;
2557 	case BPF_PROG_TYPE_CGROUP_SKB:
2558 		/* always unpriv */
2559 	case BPF_PROG_TYPE_SK_REUSEPORT:
2560 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2561 	default:
2562 		return false;
2563 	}
2564 }
2565 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2566 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2567 {
2568 	switch (prog_type) {
2569 	case BPF_PROG_TYPE_KPROBE:
2570 	case BPF_PROG_TYPE_TRACEPOINT:
2571 	case BPF_PROG_TYPE_PERF_EVENT:
2572 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2573 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2574 	case BPF_PROG_TYPE_TRACING:
2575 	case BPF_PROG_TYPE_LSM:
2576 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2577 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2578 		return true;
2579 	default:
2580 		return false;
2581 	}
2582 }
2583 
2584 /* last field in 'union bpf_attr' used by this command */
2585 #define	BPF_PROG_LOAD_LAST_FIELD log_true_size
2586 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2587 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2588 {
2589 	enum bpf_prog_type type = attr->prog_type;
2590 	struct bpf_prog *prog, *dst_prog = NULL;
2591 	struct btf *attach_btf = NULL;
2592 	int err;
2593 	char license[128];
2594 
2595 	if (CHECK_ATTR(BPF_PROG_LOAD))
2596 		return -EINVAL;
2597 
2598 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2599 				 BPF_F_ANY_ALIGNMENT |
2600 				 BPF_F_TEST_STATE_FREQ |
2601 				 BPF_F_SLEEPABLE |
2602 				 BPF_F_TEST_RND_HI32 |
2603 				 BPF_F_XDP_HAS_FRAGS |
2604 				 BPF_F_XDP_DEV_BOUND_ONLY))
2605 		return -EINVAL;
2606 
2607 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2608 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2609 	    !bpf_capable())
2610 		return -EPERM;
2611 
2612 	/* Intent here is for unprivileged_bpf_disabled to block BPF program
2613 	 * creation for unprivileged users; other actions depend
2614 	 * on fd availability and access to bpffs, so are dependent on
2615 	 * object creation success. Even with unprivileged BPF disabled,
2616 	 * capability checks are still carried out for these
2617 	 * and other operations.
2618 	 */
2619 	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
2620 		return -EPERM;
2621 
2622 	if (attr->insn_cnt == 0 ||
2623 	    attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
2624 		return -E2BIG;
2625 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2626 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2627 	    !bpf_capable())
2628 		return -EPERM;
2629 
2630 	if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
2631 		return -EPERM;
2632 	if (is_perfmon_prog_type(type) && !perfmon_capable())
2633 		return -EPERM;
2634 
2635 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2636 	 * or btf, we need to check which one it is
2637 	 */
2638 	if (attr->attach_prog_fd) {
2639 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2640 		if (IS_ERR(dst_prog)) {
2641 			dst_prog = NULL;
2642 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2643 			if (IS_ERR(attach_btf))
2644 				return -EINVAL;
2645 			if (!btf_is_kernel(attach_btf)) {
2646 				/* attaching through specifying bpf_prog's BTF
2647 				 * objects directly might be supported eventually
2648 				 */
2649 				btf_put(attach_btf);
2650 				return -ENOTSUPP;
2651 			}
2652 		}
2653 	} else if (attr->attach_btf_id) {
2654 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2655 		attach_btf = bpf_get_btf_vmlinux();
2656 		if (IS_ERR(attach_btf))
2657 			return PTR_ERR(attach_btf);
2658 		if (!attach_btf)
2659 			return -EINVAL;
2660 		btf_get(attach_btf);
2661 	}
2662 
2663 	bpf_prog_load_fixup_attach_type(attr);
2664 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2665 				       attach_btf, attr->attach_btf_id,
2666 				       dst_prog)) {
2667 		if (dst_prog)
2668 			bpf_prog_put(dst_prog);
2669 		if (attach_btf)
2670 			btf_put(attach_btf);
2671 		return -EINVAL;
2672 	}
2673 
2674 	/* plain bpf_prog allocation */
2675 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2676 	if (!prog) {
2677 		if (dst_prog)
2678 			bpf_prog_put(dst_prog);
2679 		if (attach_btf)
2680 			btf_put(attach_btf);
2681 		return -ENOMEM;
2682 	}
2683 
2684 	prog->expected_attach_type = attr->expected_attach_type;
2685 	prog->aux->attach_btf = attach_btf;
2686 	prog->aux->attach_btf_id = attr->attach_btf_id;
2687 	prog->aux->dst_prog = dst_prog;
2688 	prog->aux->dev_bound = !!attr->prog_ifindex;
2689 	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
2690 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
2691 
2692 	err = security_bpf_prog_alloc(prog->aux);
2693 	if (err)
2694 		goto free_prog;
2695 
2696 	prog->aux->user = get_current_user();
2697 	prog->len = attr->insn_cnt;
2698 
2699 	err = -EFAULT;
2700 	if (copy_from_bpfptr(prog->insns,
2701 			     make_bpfptr(attr->insns, uattr.is_kernel),
2702 			     bpf_prog_insn_size(prog)) != 0)
2703 		goto free_prog_sec;
2704 	/* copy eBPF program license from user space */
2705 	if (strncpy_from_bpfptr(license,
2706 				make_bpfptr(attr->license, uattr.is_kernel),
2707 				sizeof(license) - 1) < 0)
2708 		goto free_prog_sec;
2709 	license[sizeof(license) - 1] = 0;
2710 
2711 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
2712 	prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
2713 
2714 	prog->orig_prog = NULL;
2715 	prog->jited = 0;
2716 
2717 	atomic64_set(&prog->aux->refcnt, 1);
2718 
2719 	if (bpf_prog_is_dev_bound(prog->aux)) {
2720 		err = bpf_prog_dev_bound_init(prog, attr);
2721 		if (err)
2722 			goto free_prog_sec;
2723 	}
2724 
2725 	if (type == BPF_PROG_TYPE_EXT && dst_prog &&
2726 	    bpf_prog_is_dev_bound(dst_prog->aux)) {
2727 		err = bpf_prog_dev_bound_inherit(prog, dst_prog);
2728 		if (err)
2729 			goto free_prog_sec;
2730 	}
2731 
2732 	/* find program type: socket_filter vs tracing_filter */
2733 	err = find_prog_type(type, prog);
2734 	if (err < 0)
2735 		goto free_prog_sec;
2736 
2737 	prog->aux->load_time = ktime_get_boottime_ns();
2738 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2739 			       sizeof(attr->prog_name));
2740 	if (err < 0)
2741 		goto free_prog_sec;
2742 
2743 	/* run eBPF verifier */
2744 	err = bpf_check(&prog, attr, uattr, uattr_size);
2745 	if (err < 0)
2746 		goto free_used_maps;
2747 
2748 	prog = bpf_prog_select_runtime(prog, &err);
2749 	if (err < 0)
2750 		goto free_used_maps;
2751 
2752 	err = bpf_prog_alloc_id(prog);
2753 	if (err)
2754 		goto free_used_maps;
2755 
2756 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
2757 	 * effectively publicly exposed. However, retrieving via
2758 	 * bpf_prog_get_fd_by_id() will take another reference,
2759 	 * therefore it cannot be gone underneath us.
2760 	 *
2761 	 * Only for the time /after/ successful bpf_prog_new_fd()
2762 	 * and before returning to userspace, we might just hold
2763 	 * one reference and any parallel close on that fd could
2764 	 * rip everything out. Hence, below notifications must
2765 	 * happen before bpf_prog_new_fd().
2766 	 *
2767 	 * Also, any failure handling from this point onwards must
2768 	 * be using bpf_prog_put() given the program is exposed.
2769 	 */
2770 	bpf_prog_kallsyms_add(prog);
2771 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2772 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
2773 
2774 	err = bpf_prog_new_fd(prog);
2775 	if (err < 0)
2776 		bpf_prog_put(prog);
2777 	return err;
2778 
2779 free_used_maps:
2780 	/* In case we have subprogs, we need to wait for a grace
2781 	 * period before we can tear down JIT memory since symbols
2782 	 * are already exposed under kallsyms.
2783 	 */
2784 	__bpf_prog_put_noref(prog, prog->aux->func_cnt);
2785 	return err;
2786 free_prog_sec:
2787 	free_uid(prog->aux->user);
2788 	security_bpf_prog_free(prog->aux);
2789 free_prog:
2790 	if (prog->aux->attach_btf)
2791 		btf_put(prog->aux->attach_btf);
2792 	bpf_prog_free(prog);
2793 	return err;
2794 }
2795 
2796 #define BPF_OBJ_LAST_FIELD path_fd
2797 
bpf_obj_pin(const union bpf_attr * attr)2798 static int bpf_obj_pin(const union bpf_attr *attr)
2799 {
2800 	int path_fd;
2801 
2802 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
2803 		return -EINVAL;
2804 
2805 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
2806 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
2807 		return -EINVAL;
2808 
2809 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
2810 	return bpf_obj_pin_user(attr->bpf_fd, path_fd,
2811 				u64_to_user_ptr(attr->pathname));
2812 }
2813 
bpf_obj_get(const union bpf_attr * attr)2814 static int bpf_obj_get(const union bpf_attr *attr)
2815 {
2816 	int path_fd;
2817 
2818 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
2819 	    attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
2820 		return -EINVAL;
2821 
2822 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
2823 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
2824 		return -EINVAL;
2825 
2826 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
2827 	return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
2828 				attr->file_flags);
2829 }
2830 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)2831 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
2832 		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
2833 {
2834 	WARN_ON(ops->dealloc && ops->dealloc_deferred);
2835 	atomic64_set(&link->refcnt, 1);
2836 	link->type = type;
2837 	link->id = 0;
2838 	link->ops = ops;
2839 	link->prog = prog;
2840 }
2841 
bpf_link_free_id(int id)2842 static void bpf_link_free_id(int id)
2843 {
2844 	if (!id)
2845 		return;
2846 
2847 	spin_lock_bh(&link_idr_lock);
2848 	idr_remove(&link_idr, id);
2849 	spin_unlock_bh(&link_idr_lock);
2850 }
2851 
2852 /* Clean up bpf_link and corresponding anon_inode file and FD. After
2853  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
2854  * anon_inode's release() call. This helper marks bpf_link as
2855  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
2856  * is not decremented, it's the responsibility of a calling code that failed
2857  * to complete bpf_link initialization.
2858  * This helper eventually calls link's dealloc callback, but does not call
2859  * link's release callback.
2860  */
bpf_link_cleanup(struct bpf_link_primer * primer)2861 void bpf_link_cleanup(struct bpf_link_primer *primer)
2862 {
2863 	primer->link->prog = NULL;
2864 	bpf_link_free_id(primer->id);
2865 	fput(primer->file);
2866 	put_unused_fd(primer->fd);
2867 }
2868 
bpf_link_inc(struct bpf_link * link)2869 void bpf_link_inc(struct bpf_link *link)
2870 {
2871 	atomic64_inc(&link->refcnt);
2872 }
2873 
bpf_link_dealloc(struct bpf_link * link)2874 static void bpf_link_dealloc(struct bpf_link *link)
2875 {
2876 	/* now that we know that bpf_link itself can't be reached, put underlying BPF program */
2877 	if (link->prog)
2878 		bpf_prog_put(link->prog);
2879 
2880 	/* free bpf_link and its containing memory */
2881 	if (link->ops->dealloc_deferred)
2882 		link->ops->dealloc_deferred(link);
2883 	else
2884 		link->ops->dealloc(link);
2885 }
2886 
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)2887 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
2888 {
2889 	struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
2890 
2891 	bpf_link_dealloc(link);
2892 }
2893 
bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head * rcu)2894 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
2895 {
2896 	if (rcu_trace_implies_rcu_gp())
2897 		bpf_link_defer_dealloc_rcu_gp(rcu);
2898 	else
2899 		call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
2900 }
2901 
2902 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)2903 static void bpf_link_free(struct bpf_link *link)
2904 {
2905 	const struct bpf_link_ops *ops = link->ops;
2906 	bool sleepable = false;
2907 
2908 	bpf_link_free_id(link->id);
2909 	if (link->prog) {
2910 		sleepable = link->prog->aux->sleepable;
2911 		/* detach BPF program, clean up used resources */
2912 		ops->release(link);
2913 	}
2914 	if (ops->dealloc_deferred) {
2915 		/* schedule BPF link deallocation; if underlying BPF program
2916 		 * is sleepable, we need to first wait for RCU tasks trace
2917 		 * sync, then go through "classic" RCU grace period
2918 		 */
2919 		if (sleepable)
2920 			call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
2921 		else
2922 			call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
2923 	} else if (ops->dealloc) {
2924 		bpf_link_dealloc(link);
2925 	}
2926 }
2927 
bpf_link_put_deferred(struct work_struct * work)2928 static void bpf_link_put_deferred(struct work_struct *work)
2929 {
2930 	struct bpf_link *link = container_of(work, struct bpf_link, work);
2931 
2932 	bpf_link_free(link);
2933 }
2934 
2935 /* bpf_link_put might be called from atomic context. It needs to be called
2936  * from sleepable context in order to acquire sleeping locks during the process.
2937  */
bpf_link_put(struct bpf_link * link)2938 void bpf_link_put(struct bpf_link *link)
2939 {
2940 	if (!atomic64_dec_and_test(&link->refcnt))
2941 		return;
2942 
2943 	INIT_WORK(&link->work, bpf_link_put_deferred);
2944 	schedule_work(&link->work);
2945 }
2946 EXPORT_SYMBOL(bpf_link_put);
2947 
bpf_link_put_direct(struct bpf_link * link)2948 static void bpf_link_put_direct(struct bpf_link *link)
2949 {
2950 	if (!atomic64_dec_and_test(&link->refcnt))
2951 		return;
2952 	bpf_link_free(link);
2953 }
2954 
bpf_link_release(struct inode * inode,struct file * filp)2955 static int bpf_link_release(struct inode *inode, struct file *filp)
2956 {
2957 	struct bpf_link *link = filp->private_data;
2958 
2959 	bpf_link_put_direct(link);
2960 	return 0;
2961 }
2962 
2963 #ifdef CONFIG_PROC_FS
2964 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
2965 #define BPF_MAP_TYPE(_id, _ops)
2966 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
2967 static const char *bpf_link_type_strs[] = {
2968 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
2969 #include <linux/bpf_types.h>
2970 };
2971 #undef BPF_PROG_TYPE
2972 #undef BPF_MAP_TYPE
2973 #undef BPF_LINK_TYPE
2974 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)2975 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
2976 {
2977 	const struct bpf_link *link = filp->private_data;
2978 	const struct bpf_prog *prog = link->prog;
2979 	enum bpf_link_type type = link->type;
2980 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2981 
2982 	if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
2983 		seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
2984 	} else {
2985 		WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
2986 		seq_printf(m, "link_type:\t<%u>\n", type);
2987 	}
2988 	seq_printf(m, "link_id:\t%u\n", link->id);
2989 
2990 	if (prog) {
2991 		bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2992 		seq_printf(m,
2993 			   "prog_tag:\t%s\n"
2994 			   "prog_id:\t%u\n",
2995 			   prog_tag,
2996 			   prog->aux->id);
2997 	}
2998 	if (link->ops->show_fdinfo)
2999 		link->ops->show_fdinfo(link, m);
3000 }
3001 #endif
3002 
3003 static const struct file_operations bpf_link_fops = {
3004 #ifdef CONFIG_PROC_FS
3005 	.show_fdinfo	= bpf_link_show_fdinfo,
3006 #endif
3007 	.release	= bpf_link_release,
3008 	.read		= bpf_dummy_read,
3009 	.write		= bpf_dummy_write,
3010 };
3011 
bpf_link_alloc_id(struct bpf_link * link)3012 static int bpf_link_alloc_id(struct bpf_link *link)
3013 {
3014 	int id;
3015 
3016 	idr_preload(GFP_KERNEL);
3017 	spin_lock_bh(&link_idr_lock);
3018 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3019 	spin_unlock_bh(&link_idr_lock);
3020 	idr_preload_end();
3021 
3022 	return id;
3023 }
3024 
3025 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3026  * reserving unused FD and allocating ID from link_idr. This is to be paired
3027  * with bpf_link_settle() to install FD and ID and expose bpf_link to
3028  * user-space, if bpf_link is successfully attached. If not, bpf_link and
3029  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3030  * transient state is passed around in struct bpf_link_primer.
3031  * This is preferred way to create and initialize bpf_link, especially when
3032  * there are complicated and expensive operations in between creating bpf_link
3033  * itself and attaching it to BPF hook. By using bpf_link_prime() and
3034  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3035  * expensive (and potentially failing) roll back operations in a rare case
3036  * that file, FD, or ID can't be allocated.
3037  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3038 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3039 {
3040 	struct file *file;
3041 	int fd, id;
3042 
3043 	fd = get_unused_fd_flags(O_CLOEXEC);
3044 	if (fd < 0)
3045 		return fd;
3046 
3047 
3048 	id = bpf_link_alloc_id(link);
3049 	if (id < 0) {
3050 		put_unused_fd(fd);
3051 		return id;
3052 	}
3053 
3054 	file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
3055 	if (IS_ERR(file)) {
3056 		bpf_link_free_id(id);
3057 		put_unused_fd(fd);
3058 		return PTR_ERR(file);
3059 	}
3060 
3061 	primer->link = link;
3062 	primer->file = file;
3063 	primer->fd = fd;
3064 	primer->id = id;
3065 	return 0;
3066 }
3067 
bpf_link_settle(struct bpf_link_primer * primer)3068 int bpf_link_settle(struct bpf_link_primer *primer)
3069 {
3070 	/* make bpf_link fetchable by ID */
3071 	spin_lock_bh(&link_idr_lock);
3072 	primer->link->id = primer->id;
3073 	spin_unlock_bh(&link_idr_lock);
3074 	/* make bpf_link fetchable by FD */
3075 	fd_install(primer->fd, primer->file);
3076 	/* pass through installed FD */
3077 	return primer->fd;
3078 }
3079 
bpf_link_new_fd(struct bpf_link * link)3080 int bpf_link_new_fd(struct bpf_link *link)
3081 {
3082 	return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
3083 }
3084 
bpf_link_get_from_fd(u32 ufd)3085 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3086 {
3087 	struct fd f = fdget(ufd);
3088 	struct bpf_link *link;
3089 
3090 	if (!f.file)
3091 		return ERR_PTR(-EBADF);
3092 	if (f.file->f_op != &bpf_link_fops) {
3093 		fdput(f);
3094 		return ERR_PTR(-EINVAL);
3095 	}
3096 
3097 	link = f.file->private_data;
3098 	bpf_link_inc(link);
3099 	fdput(f);
3100 
3101 	return link;
3102 }
3103 EXPORT_SYMBOL(bpf_link_get_from_fd);
3104 
bpf_tracing_link_release(struct bpf_link * link)3105 static void bpf_tracing_link_release(struct bpf_link *link)
3106 {
3107 	struct bpf_tracing_link *tr_link =
3108 		container_of(link, struct bpf_tracing_link, link.link);
3109 
3110 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3111 						tr_link->trampoline));
3112 
3113 	bpf_trampoline_put(tr_link->trampoline);
3114 
3115 	/* tgt_prog is NULL if target is a kernel function */
3116 	if (tr_link->tgt_prog)
3117 		bpf_prog_put(tr_link->tgt_prog);
3118 }
3119 
bpf_tracing_link_dealloc(struct bpf_link * link)3120 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3121 {
3122 	struct bpf_tracing_link *tr_link =
3123 		container_of(link, struct bpf_tracing_link, link.link);
3124 
3125 	kfree(tr_link);
3126 }
3127 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3128 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3129 					 struct seq_file *seq)
3130 {
3131 	struct bpf_tracing_link *tr_link =
3132 		container_of(link, struct bpf_tracing_link, link.link);
3133 	u32 target_btf_id, target_obj_id;
3134 
3135 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3136 				  &target_obj_id, &target_btf_id);
3137 	seq_printf(seq,
3138 		   "attach_type:\t%d\n"
3139 		   "target_obj_id:\t%u\n"
3140 		   "target_btf_id:\t%u\n",
3141 		   tr_link->attach_type,
3142 		   target_obj_id,
3143 		   target_btf_id);
3144 }
3145 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3146 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3147 					   struct bpf_link_info *info)
3148 {
3149 	struct bpf_tracing_link *tr_link =
3150 		container_of(link, struct bpf_tracing_link, link.link);
3151 
3152 	info->tracing.attach_type = tr_link->attach_type;
3153 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3154 				  &info->tracing.target_obj_id,
3155 				  &info->tracing.target_btf_id);
3156 
3157 	return 0;
3158 }
3159 
3160 static const struct bpf_link_ops bpf_tracing_link_lops = {
3161 	.release = bpf_tracing_link_release,
3162 	.dealloc = bpf_tracing_link_dealloc,
3163 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3164 	.fill_link_info = bpf_tracing_link_fill_link_info,
3165 };
3166 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)3167 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3168 				   int tgt_prog_fd,
3169 				   u32 btf_id,
3170 				   u64 bpf_cookie)
3171 {
3172 	struct bpf_link_primer link_primer;
3173 	struct bpf_prog *tgt_prog = NULL;
3174 	struct bpf_trampoline *tr = NULL;
3175 	struct bpf_tracing_link *link;
3176 	u64 key = 0;
3177 	int err;
3178 
3179 	switch (prog->type) {
3180 	case BPF_PROG_TYPE_TRACING:
3181 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3182 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3183 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3184 			err = -EINVAL;
3185 			goto out_put_prog;
3186 		}
3187 		break;
3188 	case BPF_PROG_TYPE_EXT:
3189 		if (prog->expected_attach_type != 0) {
3190 			err = -EINVAL;
3191 			goto out_put_prog;
3192 		}
3193 		break;
3194 	case BPF_PROG_TYPE_LSM:
3195 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3196 			err = -EINVAL;
3197 			goto out_put_prog;
3198 		}
3199 		break;
3200 	default:
3201 		err = -EINVAL;
3202 		goto out_put_prog;
3203 	}
3204 
3205 	if (!!tgt_prog_fd != !!btf_id) {
3206 		err = -EINVAL;
3207 		goto out_put_prog;
3208 	}
3209 
3210 	if (tgt_prog_fd) {
3211 		/* For now we only allow new targets for BPF_PROG_TYPE_EXT */
3212 		if (prog->type != BPF_PROG_TYPE_EXT) {
3213 			err = -EINVAL;
3214 			goto out_put_prog;
3215 		}
3216 
3217 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3218 		if (IS_ERR(tgt_prog)) {
3219 			err = PTR_ERR(tgt_prog);
3220 			tgt_prog = NULL;
3221 			goto out_put_prog;
3222 		}
3223 
3224 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3225 	}
3226 
3227 	link = kzalloc(sizeof(*link), GFP_USER);
3228 	if (!link) {
3229 		err = -ENOMEM;
3230 		goto out_put_prog;
3231 	}
3232 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3233 		      &bpf_tracing_link_lops, prog);
3234 	link->attach_type = prog->expected_attach_type;
3235 	link->link.cookie = bpf_cookie;
3236 
3237 	mutex_lock(&prog->aux->dst_mutex);
3238 
3239 	/* There are a few possible cases here:
3240 	 *
3241 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3242 	 *   and not yet attached to anything, so we can use the values stored
3243 	 *   in prog->aux
3244 	 *
3245 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3246          *   attached to a target and its initial target was cleared (below)
3247 	 *
3248 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3249 	 *   target_btf_id using the link_create API.
3250 	 *
3251 	 * - if tgt_prog == NULL when this function was called using the old
3252 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3253 	 *
3254 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3255 	 *   was detached and is going for re-attachment.
3256 	 *
3257 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3258 	 *   are NULL, then program was already attached and user did not provide
3259 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3260 	 */
3261 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3262 		/*
3263 		 * Allow re-attach for TRACING and LSM programs. If it's
3264 		 * currently linked, bpf_trampoline_link_prog will fail.
3265 		 * EXT programs need to specify tgt_prog_fd, so they
3266 		 * re-attach in separate code path.
3267 		 */
3268 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3269 		    prog->type != BPF_PROG_TYPE_LSM) {
3270 			err = -EINVAL;
3271 			goto out_unlock;
3272 		}
3273 		/* We can allow re-attach only if we have valid attach_btf. */
3274 		if (!prog->aux->attach_btf) {
3275 			err = -EINVAL;
3276 			goto out_unlock;
3277 		}
3278 		btf_id = prog->aux->attach_btf_id;
3279 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3280 	}
3281 
3282 	if (!prog->aux->dst_trampoline ||
3283 	    (key && key != prog->aux->dst_trampoline->key)) {
3284 		/* If there is no saved target, or the specified target is
3285 		 * different from the destination specified at load time, we
3286 		 * need a new trampoline and a check for compatibility
3287 		 */
3288 		struct bpf_attach_target_info tgt_info = {};
3289 
3290 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3291 					      &tgt_info);
3292 		if (err)
3293 			goto out_unlock;
3294 
3295 		if (tgt_info.tgt_mod) {
3296 			module_put(prog->aux->mod);
3297 			prog->aux->mod = tgt_info.tgt_mod;
3298 		}
3299 
3300 		tr = bpf_trampoline_get(key, &tgt_info);
3301 		if (!tr) {
3302 			err = -ENOMEM;
3303 			goto out_unlock;
3304 		}
3305 	} else {
3306 		/* The caller didn't specify a target, or the target was the
3307 		 * same as the destination supplied during program load. This
3308 		 * means we can reuse the trampoline and reference from program
3309 		 * load time, and there is no need to allocate a new one. This
3310 		 * can only happen once for any program, as the saved values in
3311 		 * prog->aux are cleared below.
3312 		 */
3313 		tr = prog->aux->dst_trampoline;
3314 		tgt_prog = prog->aux->dst_prog;
3315 	}
3316 
3317 	err = bpf_link_prime(&link->link.link, &link_primer);
3318 	if (err)
3319 		goto out_unlock;
3320 
3321 	err = bpf_trampoline_link_prog(&link->link, tr);
3322 	if (err) {
3323 		bpf_link_cleanup(&link_primer);
3324 		link = NULL;
3325 		goto out_unlock;
3326 	}
3327 
3328 	link->tgt_prog = tgt_prog;
3329 	link->trampoline = tr;
3330 
3331 	/* Always clear the trampoline and target prog from prog->aux to make
3332 	 * sure the original attach destination is not kept alive after a
3333 	 * program is (re-)attached to another target.
3334 	 */
3335 	if (prog->aux->dst_prog &&
3336 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3337 		/* got extra prog ref from syscall, or attaching to different prog */
3338 		bpf_prog_put(prog->aux->dst_prog);
3339 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3340 		/* we allocated a new trampoline, so free the old one */
3341 		bpf_trampoline_put(prog->aux->dst_trampoline);
3342 
3343 	prog->aux->dst_prog = NULL;
3344 	prog->aux->dst_trampoline = NULL;
3345 	mutex_unlock(&prog->aux->dst_mutex);
3346 
3347 	return bpf_link_settle(&link_primer);
3348 out_unlock:
3349 	if (tr && tr != prog->aux->dst_trampoline)
3350 		bpf_trampoline_put(tr);
3351 	mutex_unlock(&prog->aux->dst_mutex);
3352 	kfree(link);
3353 out_put_prog:
3354 	if (tgt_prog_fd && tgt_prog)
3355 		bpf_prog_put(tgt_prog);
3356 	return err;
3357 }
3358 
3359 struct bpf_raw_tp_link {
3360 	struct bpf_link link;
3361 	struct bpf_raw_event_map *btp;
3362 };
3363 
bpf_raw_tp_link_release(struct bpf_link * link)3364 static void bpf_raw_tp_link_release(struct bpf_link *link)
3365 {
3366 	struct bpf_raw_tp_link *raw_tp =
3367 		container_of(link, struct bpf_raw_tp_link, link);
3368 
3369 	bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
3370 	bpf_put_raw_tracepoint(raw_tp->btp);
3371 }
3372 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3373 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3374 {
3375 	struct bpf_raw_tp_link *raw_tp =
3376 		container_of(link, struct bpf_raw_tp_link, link);
3377 
3378 	kfree(raw_tp);
3379 }
3380 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3381 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3382 					struct seq_file *seq)
3383 {
3384 	struct bpf_raw_tp_link *raw_tp_link =
3385 		container_of(link, struct bpf_raw_tp_link, link);
3386 
3387 	seq_printf(seq,
3388 		   "tp_name:\t%s\n",
3389 		   raw_tp_link->btp->tp->name);
3390 }
3391 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3392 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3393 			    u32 len)
3394 {
3395 	if (ulen >= len + 1) {
3396 		if (copy_to_user(ubuf, buf, len + 1))
3397 			return -EFAULT;
3398 	} else {
3399 		char zero = '\0';
3400 
3401 		if (copy_to_user(ubuf, buf, ulen - 1))
3402 			return -EFAULT;
3403 		if (put_user(zero, ubuf + ulen - 1))
3404 			return -EFAULT;
3405 		return -ENOSPC;
3406 	}
3407 
3408 	return 0;
3409 }
3410 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3411 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3412 					  struct bpf_link_info *info)
3413 {
3414 	struct bpf_raw_tp_link *raw_tp_link =
3415 		container_of(link, struct bpf_raw_tp_link, link);
3416 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3417 	const char *tp_name = raw_tp_link->btp->tp->name;
3418 	u32 ulen = info->raw_tracepoint.tp_name_len;
3419 	size_t tp_len = strlen(tp_name);
3420 
3421 	if (!ulen ^ !ubuf)
3422 		return -EINVAL;
3423 
3424 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3425 
3426 	if (!ubuf)
3427 		return 0;
3428 
3429 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3430 }
3431 
3432 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3433 	.release = bpf_raw_tp_link_release,
3434 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3435 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3436 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3437 };
3438 
3439 #ifdef CONFIG_PERF_EVENTS
3440 struct bpf_perf_link {
3441 	struct bpf_link link;
3442 	struct file *perf_file;
3443 };
3444 
bpf_perf_link_release(struct bpf_link * link)3445 static void bpf_perf_link_release(struct bpf_link *link)
3446 {
3447 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3448 	struct perf_event *event = perf_link->perf_file->private_data;
3449 
3450 	perf_event_free_bpf_prog(event);
3451 	fput(perf_link->perf_file);
3452 }
3453 
bpf_perf_link_dealloc(struct bpf_link * link)3454 static void bpf_perf_link_dealloc(struct bpf_link *link)
3455 {
3456 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3457 
3458 	kfree(perf_link);
3459 }
3460 
bpf_perf_link_fill_common(const struct perf_event * event,char __user * uname,u32 * ulenp,u64 * probe_offset,u64 * probe_addr,u32 * fd_type,unsigned long * missed)3461 static int bpf_perf_link_fill_common(const struct perf_event *event,
3462 				     char __user *uname, u32 *ulenp,
3463 				     u64 *probe_offset, u64 *probe_addr,
3464 				     u32 *fd_type, unsigned long *missed)
3465 {
3466 	const char *buf;
3467 	u32 prog_id, ulen;
3468 	size_t len;
3469 	int err;
3470 
3471 	ulen = *ulenp;
3472 	if (!ulen ^ !uname)
3473 		return -EINVAL;
3474 
3475 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3476 				      probe_offset, probe_addr, missed);
3477 	if (err)
3478 		return err;
3479 
3480 	if (buf) {
3481 		len = strlen(buf);
3482 		*ulenp = len + 1;
3483 	} else {
3484 		*ulenp = 1;
3485 	}
3486 	if (!uname)
3487 		return 0;
3488 
3489 	if (buf) {
3490 		err = bpf_copy_to_user(uname, buf, ulen, len);
3491 		if (err)
3492 			return err;
3493 	} else {
3494 		char zero = '\0';
3495 
3496 		if (put_user(zero, uname))
3497 			return -EFAULT;
3498 	}
3499 	return 0;
3500 }
3501 
3502 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3503 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3504 				     struct bpf_link_info *info)
3505 {
3506 	unsigned long missed;
3507 	char __user *uname;
3508 	u64 addr, offset;
3509 	u32 ulen, type;
3510 	int err;
3511 
3512 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3513 	ulen = info->perf_event.kprobe.name_len;
3514 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3515 					&type, &missed);
3516 	if (err)
3517 		return err;
3518 	if (type == BPF_FD_TYPE_KRETPROBE)
3519 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3520 	else
3521 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3522 	info->perf_event.kprobe.name_len = ulen;
3523 	info->perf_event.kprobe.offset = offset;
3524 	info->perf_event.kprobe.missed = missed;
3525 	if (!kallsyms_show_value(current_cred()))
3526 		addr = 0;
3527 	info->perf_event.kprobe.addr = addr;
3528 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3529 	return 0;
3530 }
3531 #endif
3532 
3533 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3534 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3535 				     struct bpf_link_info *info)
3536 {
3537 	char __user *uname;
3538 	u64 addr, offset;
3539 	u32 ulen, type;
3540 	int err;
3541 
3542 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3543 	ulen = info->perf_event.uprobe.name_len;
3544 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3545 					&type, NULL);
3546 	if (err)
3547 		return err;
3548 
3549 	if (type == BPF_FD_TYPE_URETPROBE)
3550 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3551 	else
3552 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3553 	info->perf_event.uprobe.name_len = ulen;
3554 	info->perf_event.uprobe.offset = offset;
3555 	info->perf_event.uprobe.cookie = event->bpf_cookie;
3556 	return 0;
3557 }
3558 #endif
3559 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)3560 static int bpf_perf_link_fill_probe(const struct perf_event *event,
3561 				    struct bpf_link_info *info)
3562 {
3563 #ifdef CONFIG_KPROBE_EVENTS
3564 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
3565 		return bpf_perf_link_fill_kprobe(event, info);
3566 #endif
3567 #ifdef CONFIG_UPROBE_EVENTS
3568 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
3569 		return bpf_perf_link_fill_uprobe(event, info);
3570 #endif
3571 	return -EOPNOTSUPP;
3572 }
3573 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)3574 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
3575 					 struct bpf_link_info *info)
3576 {
3577 	char __user *uname;
3578 	u32 ulen;
3579 	int err;
3580 
3581 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
3582 	ulen = info->perf_event.tracepoint.name_len;
3583 	err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
3584 	if (err)
3585 		return err;
3586 
3587 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
3588 	info->perf_event.tracepoint.name_len = ulen;
3589 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
3590 	return 0;
3591 }
3592 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)3593 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
3594 					 struct bpf_link_info *info)
3595 {
3596 	info->perf_event.event.type = event->attr.type;
3597 	info->perf_event.event.config = event->attr.config;
3598 	info->perf_event.event.cookie = event->bpf_cookie;
3599 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
3600 	return 0;
3601 }
3602 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3603 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
3604 					struct bpf_link_info *info)
3605 {
3606 	struct bpf_perf_link *perf_link;
3607 	const struct perf_event *event;
3608 
3609 	perf_link = container_of(link, struct bpf_perf_link, link);
3610 	event = perf_get_event(perf_link->perf_file);
3611 	if (IS_ERR(event))
3612 		return PTR_ERR(event);
3613 
3614 	switch (event->prog->type) {
3615 	case BPF_PROG_TYPE_PERF_EVENT:
3616 		return bpf_perf_link_fill_perf_event(event, info);
3617 	case BPF_PROG_TYPE_TRACEPOINT:
3618 		return bpf_perf_link_fill_tracepoint(event, info);
3619 	case BPF_PROG_TYPE_KPROBE:
3620 		return bpf_perf_link_fill_probe(event, info);
3621 	default:
3622 		return -EOPNOTSUPP;
3623 	}
3624 }
3625 
3626 static const struct bpf_link_ops bpf_perf_link_lops = {
3627 	.release = bpf_perf_link_release,
3628 	.dealloc = bpf_perf_link_dealloc,
3629 	.fill_link_info = bpf_perf_link_fill_link_info,
3630 };
3631 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3632 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3633 {
3634 	struct bpf_link_primer link_primer;
3635 	struct bpf_perf_link *link;
3636 	struct perf_event *event;
3637 	struct file *perf_file;
3638 	int err;
3639 
3640 	if (attr->link_create.flags)
3641 		return -EINVAL;
3642 
3643 	perf_file = perf_event_get(attr->link_create.target_fd);
3644 	if (IS_ERR(perf_file))
3645 		return PTR_ERR(perf_file);
3646 
3647 	link = kzalloc(sizeof(*link), GFP_USER);
3648 	if (!link) {
3649 		err = -ENOMEM;
3650 		goto out_put_file;
3651 	}
3652 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3653 	link->perf_file = perf_file;
3654 
3655 	err = bpf_link_prime(&link->link, &link_primer);
3656 	if (err) {
3657 		kfree(link);
3658 		goto out_put_file;
3659 	}
3660 
3661 	event = perf_file->private_data;
3662 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3663 	if (err) {
3664 		bpf_link_cleanup(&link_primer);
3665 		goto out_put_file;
3666 	}
3667 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3668 	bpf_prog_inc(prog);
3669 
3670 	return bpf_link_settle(&link_primer);
3671 
3672 out_put_file:
3673 	fput(perf_file);
3674 	return err;
3675 }
3676 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3677 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3678 {
3679 	return -EOPNOTSUPP;
3680 }
3681 #endif /* CONFIG_PERF_EVENTS */
3682 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name)3683 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3684 				  const char __user *user_tp_name)
3685 {
3686 	struct bpf_link_primer link_primer;
3687 	struct bpf_raw_tp_link *link;
3688 	struct bpf_raw_event_map *btp;
3689 	const char *tp_name;
3690 	char buf[128];
3691 	int err;
3692 
3693 	switch (prog->type) {
3694 	case BPF_PROG_TYPE_TRACING:
3695 	case BPF_PROG_TYPE_EXT:
3696 	case BPF_PROG_TYPE_LSM:
3697 		if (user_tp_name)
3698 			/* The attach point for this category of programs
3699 			 * should be specified via btf_id during program load.
3700 			 */
3701 			return -EINVAL;
3702 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3703 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3704 			tp_name = prog->aux->attach_func_name;
3705 			break;
3706 		}
3707 		return bpf_tracing_prog_attach(prog, 0, 0, 0);
3708 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3709 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3710 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3711 			return -EFAULT;
3712 		buf[sizeof(buf) - 1] = 0;
3713 		tp_name = buf;
3714 		break;
3715 	default:
3716 		return -EINVAL;
3717 	}
3718 
3719 	btp = bpf_get_raw_tracepoint(tp_name);
3720 	if (!btp)
3721 		return -ENOENT;
3722 
3723 	link = kzalloc(sizeof(*link), GFP_USER);
3724 	if (!link) {
3725 		err = -ENOMEM;
3726 		goto out_put_btp;
3727 	}
3728 	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3729 		      &bpf_raw_tp_link_lops, prog);
3730 	link->btp = btp;
3731 
3732 	err = bpf_link_prime(&link->link, &link_primer);
3733 	if (err) {
3734 		kfree(link);
3735 		goto out_put_btp;
3736 	}
3737 
3738 	err = bpf_probe_register(link->btp, prog);
3739 	if (err) {
3740 		bpf_link_cleanup(&link_primer);
3741 		goto out_put_btp;
3742 	}
3743 
3744 	return bpf_link_settle(&link_primer);
3745 
3746 out_put_btp:
3747 	bpf_put_raw_tracepoint(btp);
3748 	return err;
3749 }
3750 
3751 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
3752 
bpf_raw_tracepoint_open(const union bpf_attr * attr)3753 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
3754 {
3755 	struct bpf_prog *prog;
3756 	int fd;
3757 
3758 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
3759 		return -EINVAL;
3760 
3761 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
3762 	if (IS_ERR(prog))
3763 		return PTR_ERR(prog);
3764 
3765 	fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name));
3766 	if (fd < 0)
3767 		bpf_prog_put(prog);
3768 	return fd;
3769 }
3770 
3771 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)3772 attach_type_to_prog_type(enum bpf_attach_type attach_type)
3773 {
3774 	switch (attach_type) {
3775 	case BPF_CGROUP_INET_INGRESS:
3776 	case BPF_CGROUP_INET_EGRESS:
3777 		return BPF_PROG_TYPE_CGROUP_SKB;
3778 	case BPF_CGROUP_INET_SOCK_CREATE:
3779 	case BPF_CGROUP_INET_SOCK_RELEASE:
3780 	case BPF_CGROUP_INET4_POST_BIND:
3781 	case BPF_CGROUP_INET6_POST_BIND:
3782 		return BPF_PROG_TYPE_CGROUP_SOCK;
3783 	case BPF_CGROUP_INET4_BIND:
3784 	case BPF_CGROUP_INET6_BIND:
3785 	case BPF_CGROUP_INET4_CONNECT:
3786 	case BPF_CGROUP_INET6_CONNECT:
3787 	case BPF_CGROUP_INET4_GETPEERNAME:
3788 	case BPF_CGROUP_INET6_GETPEERNAME:
3789 	case BPF_CGROUP_INET4_GETSOCKNAME:
3790 	case BPF_CGROUP_INET6_GETSOCKNAME:
3791 	case BPF_CGROUP_UDP4_SENDMSG:
3792 	case BPF_CGROUP_UDP6_SENDMSG:
3793 	case BPF_CGROUP_UDP4_RECVMSG:
3794 	case BPF_CGROUP_UDP6_RECVMSG:
3795 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
3796 	case BPF_CGROUP_SOCK_OPS:
3797 		return BPF_PROG_TYPE_SOCK_OPS;
3798 	case BPF_CGROUP_DEVICE:
3799 		return BPF_PROG_TYPE_CGROUP_DEVICE;
3800 	case BPF_SK_MSG_VERDICT:
3801 		return BPF_PROG_TYPE_SK_MSG;
3802 	case BPF_SK_SKB_STREAM_PARSER:
3803 	case BPF_SK_SKB_STREAM_VERDICT:
3804 	case BPF_SK_SKB_VERDICT:
3805 		return BPF_PROG_TYPE_SK_SKB;
3806 	case BPF_LIRC_MODE2:
3807 		return BPF_PROG_TYPE_LIRC_MODE2;
3808 	case BPF_FLOW_DISSECTOR:
3809 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
3810 	case BPF_CGROUP_SYSCTL:
3811 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
3812 	case BPF_CGROUP_GETSOCKOPT:
3813 	case BPF_CGROUP_SETSOCKOPT:
3814 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
3815 	case BPF_TRACE_ITER:
3816 	case BPF_TRACE_RAW_TP:
3817 	case BPF_TRACE_FENTRY:
3818 	case BPF_TRACE_FEXIT:
3819 	case BPF_MODIFY_RETURN:
3820 		return BPF_PROG_TYPE_TRACING;
3821 	case BPF_LSM_MAC:
3822 		return BPF_PROG_TYPE_LSM;
3823 	case BPF_SK_LOOKUP:
3824 		return BPF_PROG_TYPE_SK_LOOKUP;
3825 	case BPF_XDP:
3826 		return BPF_PROG_TYPE_XDP;
3827 	case BPF_LSM_CGROUP:
3828 		return BPF_PROG_TYPE_LSM;
3829 	case BPF_TCX_INGRESS:
3830 	case BPF_TCX_EGRESS:
3831 		return BPF_PROG_TYPE_SCHED_CLS;
3832 	default:
3833 		return BPF_PROG_TYPE_UNSPEC;
3834 	}
3835 }
3836 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)3837 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
3838 					     enum bpf_attach_type attach_type)
3839 {
3840 	enum bpf_prog_type ptype;
3841 
3842 	switch (prog->type) {
3843 	case BPF_PROG_TYPE_CGROUP_SOCK:
3844 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3845 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3846 	case BPF_PROG_TYPE_SK_LOOKUP:
3847 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
3848 	case BPF_PROG_TYPE_CGROUP_SKB:
3849 		if (!capable(CAP_NET_ADMIN))
3850 			/* cg-skb progs can be loaded by unpriv user.
3851 			 * check permissions at attach time.
3852 			 */
3853 			return -EPERM;
3854 
3855 		ptype = attach_type_to_prog_type(attach_type);
3856 		if (prog->type != ptype)
3857 			return -EINVAL;
3858 
3859 		return prog->enforce_expected_attach_type &&
3860 			prog->expected_attach_type != attach_type ?
3861 			-EINVAL : 0;
3862 	case BPF_PROG_TYPE_EXT:
3863 		return 0;
3864 	case BPF_PROG_TYPE_NETFILTER:
3865 		if (attach_type != BPF_NETFILTER)
3866 			return -EINVAL;
3867 		return 0;
3868 	case BPF_PROG_TYPE_PERF_EVENT:
3869 	case BPF_PROG_TYPE_TRACEPOINT:
3870 		if (attach_type != BPF_PERF_EVENT)
3871 			return -EINVAL;
3872 		return 0;
3873 	case BPF_PROG_TYPE_KPROBE:
3874 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
3875 		    attach_type != BPF_TRACE_KPROBE_MULTI)
3876 			return -EINVAL;
3877 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
3878 		    attach_type != BPF_TRACE_UPROBE_MULTI)
3879 			return -EINVAL;
3880 		if (attach_type != BPF_PERF_EVENT &&
3881 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
3882 		    attach_type != BPF_TRACE_UPROBE_MULTI)
3883 			return -EINVAL;
3884 		return 0;
3885 	case BPF_PROG_TYPE_SCHED_CLS:
3886 		if (attach_type != BPF_TCX_INGRESS &&
3887 		    attach_type != BPF_TCX_EGRESS)
3888 			return -EINVAL;
3889 		return 0;
3890 	default:
3891 		ptype = attach_type_to_prog_type(attach_type);
3892 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
3893 			return -EINVAL;
3894 		return 0;
3895 	}
3896 }
3897 
3898 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
3899 
3900 #define BPF_F_ATTACH_MASK_BASE	\
3901 	(BPF_F_ALLOW_OVERRIDE |	\
3902 	 BPF_F_ALLOW_MULTI |	\
3903 	 BPF_F_REPLACE)
3904 
3905 #define BPF_F_ATTACH_MASK_MPROG	\
3906 	(BPF_F_REPLACE |	\
3907 	 BPF_F_BEFORE |		\
3908 	 BPF_F_AFTER |		\
3909 	 BPF_F_ID |		\
3910 	 BPF_F_LINK)
3911 
bpf_prog_attach(const union bpf_attr * attr)3912 static int bpf_prog_attach(const union bpf_attr *attr)
3913 {
3914 	enum bpf_prog_type ptype;
3915 	struct bpf_prog *prog;
3916 	int ret;
3917 
3918 	if (CHECK_ATTR(BPF_PROG_ATTACH))
3919 		return -EINVAL;
3920 
3921 	ptype = attach_type_to_prog_type(attr->attach_type);
3922 	if (ptype == BPF_PROG_TYPE_UNSPEC)
3923 		return -EINVAL;
3924 	if (bpf_mprog_supported(ptype)) {
3925 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
3926 			return -EINVAL;
3927 	} else {
3928 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
3929 			return -EINVAL;
3930 		if (attr->relative_fd ||
3931 		    attr->expected_revision)
3932 			return -EINVAL;
3933 	}
3934 
3935 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
3936 	if (IS_ERR(prog))
3937 		return PTR_ERR(prog);
3938 
3939 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
3940 		bpf_prog_put(prog);
3941 		return -EINVAL;
3942 	}
3943 
3944 	switch (ptype) {
3945 	case BPF_PROG_TYPE_SK_SKB:
3946 	case BPF_PROG_TYPE_SK_MSG:
3947 		ret = sock_map_get_from_fd(attr, prog);
3948 		break;
3949 	case BPF_PROG_TYPE_LIRC_MODE2:
3950 		ret = lirc_prog_attach(attr, prog);
3951 		break;
3952 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
3953 		ret = netns_bpf_prog_attach(attr, prog);
3954 		break;
3955 	case BPF_PROG_TYPE_CGROUP_DEVICE:
3956 	case BPF_PROG_TYPE_CGROUP_SKB:
3957 	case BPF_PROG_TYPE_CGROUP_SOCK:
3958 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3959 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3960 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
3961 	case BPF_PROG_TYPE_SOCK_OPS:
3962 	case BPF_PROG_TYPE_LSM:
3963 		if (ptype == BPF_PROG_TYPE_LSM &&
3964 		    prog->expected_attach_type != BPF_LSM_CGROUP)
3965 			ret = -EINVAL;
3966 		else
3967 			ret = cgroup_bpf_prog_attach(attr, ptype, prog);
3968 		break;
3969 	case BPF_PROG_TYPE_SCHED_CLS:
3970 		ret = tcx_prog_attach(attr, prog);
3971 		break;
3972 	default:
3973 		ret = -EINVAL;
3974 	}
3975 
3976 	if (ret)
3977 		bpf_prog_put(prog);
3978 	return ret;
3979 }
3980 
3981 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
3982 
bpf_prog_detach(const union bpf_attr * attr)3983 static int bpf_prog_detach(const union bpf_attr *attr)
3984 {
3985 	struct bpf_prog *prog = NULL;
3986 	enum bpf_prog_type ptype;
3987 	int ret;
3988 
3989 	if (CHECK_ATTR(BPF_PROG_DETACH))
3990 		return -EINVAL;
3991 
3992 	ptype = attach_type_to_prog_type(attr->attach_type);
3993 	if (bpf_mprog_supported(ptype)) {
3994 		if (ptype == BPF_PROG_TYPE_UNSPEC)
3995 			return -EINVAL;
3996 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
3997 			return -EINVAL;
3998 		if (attr->attach_bpf_fd) {
3999 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4000 			if (IS_ERR(prog))
4001 				return PTR_ERR(prog);
4002 		}
4003 	} else if (attr->attach_flags ||
4004 		   attr->relative_fd ||
4005 		   attr->expected_revision) {
4006 		return -EINVAL;
4007 	}
4008 
4009 	switch (ptype) {
4010 	case BPF_PROG_TYPE_SK_MSG:
4011 	case BPF_PROG_TYPE_SK_SKB:
4012 		ret = sock_map_prog_detach(attr, ptype);
4013 		break;
4014 	case BPF_PROG_TYPE_LIRC_MODE2:
4015 		ret = lirc_prog_detach(attr);
4016 		break;
4017 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4018 		ret = netns_bpf_prog_detach(attr, ptype);
4019 		break;
4020 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4021 	case BPF_PROG_TYPE_CGROUP_SKB:
4022 	case BPF_PROG_TYPE_CGROUP_SOCK:
4023 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4024 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4025 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4026 	case BPF_PROG_TYPE_SOCK_OPS:
4027 	case BPF_PROG_TYPE_LSM:
4028 		ret = cgroup_bpf_prog_detach(attr, ptype);
4029 		break;
4030 	case BPF_PROG_TYPE_SCHED_CLS:
4031 		ret = tcx_prog_detach(attr, prog);
4032 		break;
4033 	default:
4034 		ret = -EINVAL;
4035 	}
4036 
4037 	if (prog)
4038 		bpf_prog_put(prog);
4039 	return ret;
4040 }
4041 
4042 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4043 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4044 static int bpf_prog_query(const union bpf_attr *attr,
4045 			  union bpf_attr __user *uattr)
4046 {
4047 	if (!capable(CAP_NET_ADMIN))
4048 		return -EPERM;
4049 	if (CHECK_ATTR(BPF_PROG_QUERY))
4050 		return -EINVAL;
4051 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4052 		return -EINVAL;
4053 
4054 	switch (attr->query.attach_type) {
4055 	case BPF_CGROUP_INET_INGRESS:
4056 	case BPF_CGROUP_INET_EGRESS:
4057 	case BPF_CGROUP_INET_SOCK_CREATE:
4058 	case BPF_CGROUP_INET_SOCK_RELEASE:
4059 	case BPF_CGROUP_INET4_BIND:
4060 	case BPF_CGROUP_INET6_BIND:
4061 	case BPF_CGROUP_INET4_POST_BIND:
4062 	case BPF_CGROUP_INET6_POST_BIND:
4063 	case BPF_CGROUP_INET4_CONNECT:
4064 	case BPF_CGROUP_INET6_CONNECT:
4065 	case BPF_CGROUP_INET4_GETPEERNAME:
4066 	case BPF_CGROUP_INET6_GETPEERNAME:
4067 	case BPF_CGROUP_INET4_GETSOCKNAME:
4068 	case BPF_CGROUP_INET6_GETSOCKNAME:
4069 	case BPF_CGROUP_UDP4_SENDMSG:
4070 	case BPF_CGROUP_UDP6_SENDMSG:
4071 	case BPF_CGROUP_UDP4_RECVMSG:
4072 	case BPF_CGROUP_UDP6_RECVMSG:
4073 	case BPF_CGROUP_SOCK_OPS:
4074 	case BPF_CGROUP_DEVICE:
4075 	case BPF_CGROUP_SYSCTL:
4076 	case BPF_CGROUP_GETSOCKOPT:
4077 	case BPF_CGROUP_SETSOCKOPT:
4078 	case BPF_LSM_CGROUP:
4079 		return cgroup_bpf_prog_query(attr, uattr);
4080 	case BPF_LIRC_MODE2:
4081 		return lirc_prog_query(attr, uattr);
4082 	case BPF_FLOW_DISSECTOR:
4083 	case BPF_SK_LOOKUP:
4084 		return netns_bpf_prog_query(attr, uattr);
4085 	case BPF_SK_SKB_STREAM_PARSER:
4086 	case BPF_SK_SKB_STREAM_VERDICT:
4087 	case BPF_SK_MSG_VERDICT:
4088 	case BPF_SK_SKB_VERDICT:
4089 		return sock_map_bpf_prog_query(attr, uattr);
4090 	case BPF_TCX_INGRESS:
4091 	case BPF_TCX_EGRESS:
4092 		return tcx_prog_query(attr, uattr);
4093 	default:
4094 		return -EINVAL;
4095 	}
4096 }
4097 
4098 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4099 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4100 static int bpf_prog_test_run(const union bpf_attr *attr,
4101 			     union bpf_attr __user *uattr)
4102 {
4103 	struct bpf_prog *prog;
4104 	int ret = -ENOTSUPP;
4105 
4106 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4107 		return -EINVAL;
4108 
4109 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4110 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4111 		return -EINVAL;
4112 
4113 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4114 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4115 		return -EINVAL;
4116 
4117 	prog = bpf_prog_get(attr->test.prog_fd);
4118 	if (IS_ERR(prog))
4119 		return PTR_ERR(prog);
4120 
4121 	if (prog->aux->ops->test_run)
4122 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4123 
4124 	bpf_prog_put(prog);
4125 	return ret;
4126 }
4127 
4128 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4129 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4130 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4131 			       union bpf_attr __user *uattr,
4132 			       struct idr *idr,
4133 			       spinlock_t *lock)
4134 {
4135 	u32 next_id = attr->start_id;
4136 	int err = 0;
4137 
4138 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4139 		return -EINVAL;
4140 
4141 	if (!capable(CAP_SYS_ADMIN))
4142 		return -EPERM;
4143 
4144 	next_id++;
4145 	spin_lock_bh(lock);
4146 	if (!idr_get_next(idr, &next_id))
4147 		err = -ENOENT;
4148 	spin_unlock_bh(lock);
4149 
4150 	if (!err)
4151 		err = put_user(next_id, &uattr->next_id);
4152 
4153 	return err;
4154 }
4155 
bpf_map_get_curr_or_next(u32 * id)4156 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4157 {
4158 	struct bpf_map *map;
4159 
4160 	spin_lock_bh(&map_idr_lock);
4161 again:
4162 	map = idr_get_next(&map_idr, id);
4163 	if (map) {
4164 		map = __bpf_map_inc_not_zero(map, false);
4165 		if (IS_ERR(map)) {
4166 			(*id)++;
4167 			goto again;
4168 		}
4169 	}
4170 	spin_unlock_bh(&map_idr_lock);
4171 
4172 	return map;
4173 }
4174 
bpf_prog_get_curr_or_next(u32 * id)4175 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4176 {
4177 	struct bpf_prog *prog;
4178 
4179 	spin_lock_bh(&prog_idr_lock);
4180 again:
4181 	prog = idr_get_next(&prog_idr, id);
4182 	if (prog) {
4183 		prog = bpf_prog_inc_not_zero(prog);
4184 		if (IS_ERR(prog)) {
4185 			(*id)++;
4186 			goto again;
4187 		}
4188 	}
4189 	spin_unlock_bh(&prog_idr_lock);
4190 
4191 	return prog;
4192 }
4193 
4194 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4195 
bpf_prog_by_id(u32 id)4196 struct bpf_prog *bpf_prog_by_id(u32 id)
4197 {
4198 	struct bpf_prog *prog;
4199 
4200 	if (!id)
4201 		return ERR_PTR(-ENOENT);
4202 
4203 	spin_lock_bh(&prog_idr_lock);
4204 	prog = idr_find(&prog_idr, id);
4205 	if (prog)
4206 		prog = bpf_prog_inc_not_zero(prog);
4207 	else
4208 		prog = ERR_PTR(-ENOENT);
4209 	spin_unlock_bh(&prog_idr_lock);
4210 	return prog;
4211 }
4212 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4213 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4214 {
4215 	struct bpf_prog *prog;
4216 	u32 id = attr->prog_id;
4217 	int fd;
4218 
4219 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4220 		return -EINVAL;
4221 
4222 	if (!capable(CAP_SYS_ADMIN))
4223 		return -EPERM;
4224 
4225 	prog = bpf_prog_by_id(id);
4226 	if (IS_ERR(prog))
4227 		return PTR_ERR(prog);
4228 
4229 	fd = bpf_prog_new_fd(prog);
4230 	if (fd < 0)
4231 		bpf_prog_put(prog);
4232 
4233 	return fd;
4234 }
4235 
4236 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4237 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4238 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4239 {
4240 	struct bpf_map *map;
4241 	u32 id = attr->map_id;
4242 	int f_flags;
4243 	int fd;
4244 
4245 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4246 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4247 		return -EINVAL;
4248 
4249 	if (!capable(CAP_SYS_ADMIN))
4250 		return -EPERM;
4251 
4252 	f_flags = bpf_get_file_flag(attr->open_flags);
4253 	if (f_flags < 0)
4254 		return f_flags;
4255 
4256 	spin_lock_bh(&map_idr_lock);
4257 	map = idr_find(&map_idr, id);
4258 	if (map)
4259 		map = __bpf_map_inc_not_zero(map, true);
4260 	else
4261 		map = ERR_PTR(-ENOENT);
4262 	spin_unlock_bh(&map_idr_lock);
4263 
4264 	if (IS_ERR(map))
4265 		return PTR_ERR(map);
4266 
4267 	fd = bpf_map_new_fd(map, f_flags);
4268 	if (fd < 0)
4269 		bpf_map_put_with_uref(map);
4270 
4271 	return fd;
4272 }
4273 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4274 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4275 					      unsigned long addr, u32 *off,
4276 					      u32 *type)
4277 {
4278 	const struct bpf_map *map;
4279 	int i;
4280 
4281 	mutex_lock(&prog->aux->used_maps_mutex);
4282 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4283 		map = prog->aux->used_maps[i];
4284 		if (map == (void *)addr) {
4285 			*type = BPF_PSEUDO_MAP_FD;
4286 			goto out;
4287 		}
4288 		if (!map->ops->map_direct_value_meta)
4289 			continue;
4290 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4291 			*type = BPF_PSEUDO_MAP_VALUE;
4292 			goto out;
4293 		}
4294 	}
4295 	map = NULL;
4296 
4297 out:
4298 	mutex_unlock(&prog->aux->used_maps_mutex);
4299 	return map;
4300 }
4301 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4302 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4303 					      const struct cred *f_cred)
4304 {
4305 	const struct bpf_map *map;
4306 	struct bpf_insn *insns;
4307 	u32 off, type;
4308 	u64 imm;
4309 	u8 code;
4310 	int i;
4311 
4312 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4313 			GFP_USER);
4314 	if (!insns)
4315 		return insns;
4316 
4317 	for (i = 0; i < prog->len; i++) {
4318 		code = insns[i].code;
4319 
4320 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4321 			insns[i].code = BPF_JMP | BPF_CALL;
4322 			insns[i].imm = BPF_FUNC_tail_call;
4323 			/* fall-through */
4324 		}
4325 		if (code == (BPF_JMP | BPF_CALL) ||
4326 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4327 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4328 				insns[i].code = BPF_JMP | BPF_CALL;
4329 			if (!bpf_dump_raw_ok(f_cred))
4330 				insns[i].imm = 0;
4331 			continue;
4332 		}
4333 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4334 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4335 			continue;
4336 		}
4337 
4338 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4339 			continue;
4340 
4341 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4342 		map = bpf_map_from_imm(prog, imm, &off, &type);
4343 		if (map) {
4344 			insns[i].src_reg = type;
4345 			insns[i].imm = map->id;
4346 			insns[i + 1].imm = off;
4347 			continue;
4348 		}
4349 	}
4350 
4351 	return insns;
4352 }
4353 
set_info_rec_size(struct bpf_prog_info * info)4354 static int set_info_rec_size(struct bpf_prog_info *info)
4355 {
4356 	/*
4357 	 * Ensure info.*_rec_size is the same as kernel expected size
4358 	 *
4359 	 * or
4360 	 *
4361 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4362 	 * zero.  In this case, the kernel will set the expected
4363 	 * _rec_size back to the info.
4364 	 */
4365 
4366 	if ((info->nr_func_info || info->func_info_rec_size) &&
4367 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4368 		return -EINVAL;
4369 
4370 	if ((info->nr_line_info || info->line_info_rec_size) &&
4371 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
4372 		return -EINVAL;
4373 
4374 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4375 	    info->jited_line_info_rec_size != sizeof(__u64))
4376 		return -EINVAL;
4377 
4378 	info->func_info_rec_size = sizeof(struct bpf_func_info);
4379 	info->line_info_rec_size = sizeof(struct bpf_line_info);
4380 	info->jited_line_info_rec_size = sizeof(__u64);
4381 
4382 	return 0;
4383 }
4384 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4385 static int bpf_prog_get_info_by_fd(struct file *file,
4386 				   struct bpf_prog *prog,
4387 				   const union bpf_attr *attr,
4388 				   union bpf_attr __user *uattr)
4389 {
4390 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4391 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4392 	struct bpf_prog_info info;
4393 	u32 info_len = attr->info.info_len;
4394 	struct bpf_prog_kstats stats;
4395 	char __user *uinsns;
4396 	u32 ulen;
4397 	int err;
4398 
4399 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4400 	if (err)
4401 		return err;
4402 	info_len = min_t(u32, sizeof(info), info_len);
4403 
4404 	memset(&info, 0, sizeof(info));
4405 	if (copy_from_user(&info, uinfo, info_len))
4406 		return -EFAULT;
4407 
4408 	info.type = prog->type;
4409 	info.id = prog->aux->id;
4410 	info.load_time = prog->aux->load_time;
4411 	info.created_by_uid = from_kuid_munged(current_user_ns(),
4412 					       prog->aux->user->uid);
4413 	info.gpl_compatible = prog->gpl_compatible;
4414 
4415 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
4416 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
4417 
4418 	mutex_lock(&prog->aux->used_maps_mutex);
4419 	ulen = info.nr_map_ids;
4420 	info.nr_map_ids = prog->aux->used_map_cnt;
4421 	ulen = min_t(u32, info.nr_map_ids, ulen);
4422 	if (ulen) {
4423 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
4424 		u32 i;
4425 
4426 		for (i = 0; i < ulen; i++)
4427 			if (put_user(prog->aux->used_maps[i]->id,
4428 				     &user_map_ids[i])) {
4429 				mutex_unlock(&prog->aux->used_maps_mutex);
4430 				return -EFAULT;
4431 			}
4432 	}
4433 	mutex_unlock(&prog->aux->used_maps_mutex);
4434 
4435 	err = set_info_rec_size(&info);
4436 	if (err)
4437 		return err;
4438 
4439 	bpf_prog_get_stats(prog, &stats);
4440 	info.run_time_ns = stats.nsecs;
4441 	info.run_cnt = stats.cnt;
4442 	info.recursion_misses = stats.misses;
4443 
4444 	info.verified_insns = prog->aux->verified_insns;
4445 
4446 	if (!bpf_capable()) {
4447 		info.jited_prog_len = 0;
4448 		info.xlated_prog_len = 0;
4449 		info.nr_jited_ksyms = 0;
4450 		info.nr_jited_func_lens = 0;
4451 		info.nr_func_info = 0;
4452 		info.nr_line_info = 0;
4453 		info.nr_jited_line_info = 0;
4454 		goto done;
4455 	}
4456 
4457 	ulen = info.xlated_prog_len;
4458 	info.xlated_prog_len = bpf_prog_insn_size(prog);
4459 	if (info.xlated_prog_len && ulen) {
4460 		struct bpf_insn *insns_sanitized;
4461 		bool fault;
4462 
4463 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
4464 			info.xlated_prog_insns = 0;
4465 			goto done;
4466 		}
4467 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
4468 		if (!insns_sanitized)
4469 			return -ENOMEM;
4470 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
4471 		ulen = min_t(u32, info.xlated_prog_len, ulen);
4472 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
4473 		kfree(insns_sanitized);
4474 		if (fault)
4475 			return -EFAULT;
4476 	}
4477 
4478 	if (bpf_prog_is_offloaded(prog->aux)) {
4479 		err = bpf_prog_offload_info_fill(&info, prog);
4480 		if (err)
4481 			return err;
4482 		goto done;
4483 	}
4484 
4485 	/* NOTE: the following code is supposed to be skipped for offload.
4486 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
4487 	 * for offload.
4488 	 */
4489 	ulen = info.jited_prog_len;
4490 	if (prog->aux->func_cnt) {
4491 		u32 i;
4492 
4493 		info.jited_prog_len = 0;
4494 		for (i = 0; i < prog->aux->func_cnt; i++)
4495 			info.jited_prog_len += prog->aux->func[i]->jited_len;
4496 	} else {
4497 		info.jited_prog_len = prog->jited_len;
4498 	}
4499 
4500 	if (info.jited_prog_len && ulen) {
4501 		if (bpf_dump_raw_ok(file->f_cred)) {
4502 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
4503 			ulen = min_t(u32, info.jited_prog_len, ulen);
4504 
4505 			/* for multi-function programs, copy the JITed
4506 			 * instructions for all the functions
4507 			 */
4508 			if (prog->aux->func_cnt) {
4509 				u32 len, free, i;
4510 				u8 *img;
4511 
4512 				free = ulen;
4513 				for (i = 0; i < prog->aux->func_cnt; i++) {
4514 					len = prog->aux->func[i]->jited_len;
4515 					len = min_t(u32, len, free);
4516 					img = (u8 *) prog->aux->func[i]->bpf_func;
4517 					if (copy_to_user(uinsns, img, len))
4518 						return -EFAULT;
4519 					uinsns += len;
4520 					free -= len;
4521 					if (!free)
4522 						break;
4523 				}
4524 			} else {
4525 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
4526 					return -EFAULT;
4527 			}
4528 		} else {
4529 			info.jited_prog_insns = 0;
4530 		}
4531 	}
4532 
4533 	ulen = info.nr_jited_ksyms;
4534 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4535 	if (ulen) {
4536 		if (bpf_dump_raw_ok(file->f_cred)) {
4537 			unsigned long ksym_addr;
4538 			u64 __user *user_ksyms;
4539 			u32 i;
4540 
4541 			/* copy the address of the kernel symbol
4542 			 * corresponding to each function
4543 			 */
4544 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4545 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4546 			if (prog->aux->func_cnt) {
4547 				for (i = 0; i < ulen; i++) {
4548 					ksym_addr = (unsigned long)
4549 						prog->aux->func[i]->bpf_func;
4550 					if (put_user((u64) ksym_addr,
4551 						     &user_ksyms[i]))
4552 						return -EFAULT;
4553 				}
4554 			} else {
4555 				ksym_addr = (unsigned long) prog->bpf_func;
4556 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
4557 					return -EFAULT;
4558 			}
4559 		} else {
4560 			info.jited_ksyms = 0;
4561 		}
4562 	}
4563 
4564 	ulen = info.nr_jited_func_lens;
4565 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4566 	if (ulen) {
4567 		if (bpf_dump_raw_ok(file->f_cred)) {
4568 			u32 __user *user_lens;
4569 			u32 func_len, i;
4570 
4571 			/* copy the JITed image lengths for each function */
4572 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4573 			user_lens = u64_to_user_ptr(info.jited_func_lens);
4574 			if (prog->aux->func_cnt) {
4575 				for (i = 0; i < ulen; i++) {
4576 					func_len =
4577 						prog->aux->func[i]->jited_len;
4578 					if (put_user(func_len, &user_lens[i]))
4579 						return -EFAULT;
4580 				}
4581 			} else {
4582 				func_len = prog->jited_len;
4583 				if (put_user(func_len, &user_lens[0]))
4584 					return -EFAULT;
4585 			}
4586 		} else {
4587 			info.jited_func_lens = 0;
4588 		}
4589 	}
4590 
4591 	if (prog->aux->btf)
4592 		info.btf_id = btf_obj_id(prog->aux->btf);
4593 	info.attach_btf_id = prog->aux->attach_btf_id;
4594 	if (attach_btf)
4595 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
4596 
4597 	ulen = info.nr_func_info;
4598 	info.nr_func_info = prog->aux->func_info_cnt;
4599 	if (info.nr_func_info && ulen) {
4600 		char __user *user_finfo;
4601 
4602 		user_finfo = u64_to_user_ptr(info.func_info);
4603 		ulen = min_t(u32, info.nr_func_info, ulen);
4604 		if (copy_to_user(user_finfo, prog->aux->func_info,
4605 				 info.func_info_rec_size * ulen))
4606 			return -EFAULT;
4607 	}
4608 
4609 	ulen = info.nr_line_info;
4610 	info.nr_line_info = prog->aux->nr_linfo;
4611 	if (info.nr_line_info && ulen) {
4612 		__u8 __user *user_linfo;
4613 
4614 		user_linfo = u64_to_user_ptr(info.line_info);
4615 		ulen = min_t(u32, info.nr_line_info, ulen);
4616 		if (copy_to_user(user_linfo, prog->aux->linfo,
4617 				 info.line_info_rec_size * ulen))
4618 			return -EFAULT;
4619 	}
4620 
4621 	ulen = info.nr_jited_line_info;
4622 	if (prog->aux->jited_linfo)
4623 		info.nr_jited_line_info = prog->aux->nr_linfo;
4624 	else
4625 		info.nr_jited_line_info = 0;
4626 	if (info.nr_jited_line_info && ulen) {
4627 		if (bpf_dump_raw_ok(file->f_cred)) {
4628 			unsigned long line_addr;
4629 			__u64 __user *user_linfo;
4630 			u32 i;
4631 
4632 			user_linfo = u64_to_user_ptr(info.jited_line_info);
4633 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
4634 			for (i = 0; i < ulen; i++) {
4635 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
4636 				if (put_user((__u64)line_addr, &user_linfo[i]))
4637 					return -EFAULT;
4638 			}
4639 		} else {
4640 			info.jited_line_info = 0;
4641 		}
4642 	}
4643 
4644 	ulen = info.nr_prog_tags;
4645 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4646 	if (ulen) {
4647 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4648 		u32 i;
4649 
4650 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
4651 		ulen = min_t(u32, info.nr_prog_tags, ulen);
4652 		if (prog->aux->func_cnt) {
4653 			for (i = 0; i < ulen; i++) {
4654 				if (copy_to_user(user_prog_tags[i],
4655 						 prog->aux->func[i]->tag,
4656 						 BPF_TAG_SIZE))
4657 					return -EFAULT;
4658 			}
4659 		} else {
4660 			if (copy_to_user(user_prog_tags[0],
4661 					 prog->tag, BPF_TAG_SIZE))
4662 				return -EFAULT;
4663 		}
4664 	}
4665 
4666 done:
4667 	if (copy_to_user(uinfo, &info, info_len) ||
4668 	    put_user(info_len, &uattr->info.info_len))
4669 		return -EFAULT;
4670 
4671 	return 0;
4672 }
4673 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4674 static int bpf_map_get_info_by_fd(struct file *file,
4675 				  struct bpf_map *map,
4676 				  const union bpf_attr *attr,
4677 				  union bpf_attr __user *uattr)
4678 {
4679 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4680 	struct bpf_map_info info;
4681 	u32 info_len = attr->info.info_len;
4682 	int err;
4683 
4684 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4685 	if (err)
4686 		return err;
4687 	info_len = min_t(u32, sizeof(info), info_len);
4688 
4689 	memset(&info, 0, sizeof(info));
4690 	info.type = map->map_type;
4691 	info.id = map->id;
4692 	info.key_size = map->key_size;
4693 	info.value_size = map->value_size;
4694 	info.max_entries = map->max_entries;
4695 	info.map_flags = map->map_flags;
4696 	info.map_extra = map->map_extra;
4697 	memcpy(info.name, map->name, sizeof(map->name));
4698 
4699 	if (map->btf) {
4700 		info.btf_id = btf_obj_id(map->btf);
4701 		info.btf_key_type_id = map->btf_key_type_id;
4702 		info.btf_value_type_id = map->btf_value_type_id;
4703 	}
4704 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
4705 
4706 	if (bpf_map_is_offloaded(map)) {
4707 		err = bpf_map_offload_info_fill(&info, map);
4708 		if (err)
4709 			return err;
4710 	}
4711 
4712 	if (copy_to_user(uinfo, &info, info_len) ||
4713 	    put_user(info_len, &uattr->info.info_len))
4714 		return -EFAULT;
4715 
4716 	return 0;
4717 }
4718 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)4719 static int bpf_btf_get_info_by_fd(struct file *file,
4720 				  struct btf *btf,
4721 				  const union bpf_attr *attr,
4722 				  union bpf_attr __user *uattr)
4723 {
4724 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4725 	u32 info_len = attr->info.info_len;
4726 	int err;
4727 
4728 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
4729 	if (err)
4730 		return err;
4731 
4732 	return btf_get_info_by_fd(btf, attr, uattr);
4733 }
4734 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)4735 static int bpf_link_get_info_by_fd(struct file *file,
4736 				  struct bpf_link *link,
4737 				  const union bpf_attr *attr,
4738 				  union bpf_attr __user *uattr)
4739 {
4740 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4741 	struct bpf_link_info info;
4742 	u32 info_len = attr->info.info_len;
4743 	int err;
4744 
4745 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4746 	if (err)
4747 		return err;
4748 	info_len = min_t(u32, sizeof(info), info_len);
4749 
4750 	memset(&info, 0, sizeof(info));
4751 	if (copy_from_user(&info, uinfo, info_len))
4752 		return -EFAULT;
4753 
4754 	info.type = link->type;
4755 	info.id = link->id;
4756 	if (link->prog)
4757 		info.prog_id = link->prog->aux->id;
4758 
4759 	if (link->ops->fill_link_info) {
4760 		err = link->ops->fill_link_info(link, &info);
4761 		if (err)
4762 			return err;
4763 	}
4764 
4765 	if (copy_to_user(uinfo, &info, info_len) ||
4766 	    put_user(info_len, &uattr->info.info_len))
4767 		return -EFAULT;
4768 
4769 	return 0;
4770 }
4771 
4772 
4773 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
4774 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)4775 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
4776 				  union bpf_attr __user *uattr)
4777 {
4778 	int ufd = attr->info.bpf_fd;
4779 	struct fd f;
4780 	int err;
4781 
4782 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
4783 		return -EINVAL;
4784 
4785 	f = fdget(ufd);
4786 	if (!f.file)
4787 		return -EBADFD;
4788 
4789 	if (f.file->f_op == &bpf_prog_fops)
4790 		err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
4791 					      uattr);
4792 	else if (f.file->f_op == &bpf_map_fops)
4793 		err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
4794 					     uattr);
4795 	else if (f.file->f_op == &btf_fops)
4796 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
4797 	else if (f.file->f_op == &bpf_link_fops)
4798 		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
4799 					      attr, uattr);
4800 	else
4801 		err = -EINVAL;
4802 
4803 	fdput(f);
4804 	return err;
4805 }
4806 
4807 #define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size
4808 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)4809 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
4810 {
4811 	if (CHECK_ATTR(BPF_BTF_LOAD))
4812 		return -EINVAL;
4813 
4814 	if (!bpf_capable())
4815 		return -EPERM;
4816 
4817 	return btf_new_fd(attr, uattr, uattr_size);
4818 }
4819 
4820 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
4821 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)4822 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
4823 {
4824 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
4825 		return -EINVAL;
4826 
4827 	if (!capable(CAP_SYS_ADMIN))
4828 		return -EPERM;
4829 
4830 	return btf_get_fd_by_id(attr->btf_id);
4831 }
4832 
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)4833 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
4834 				    union bpf_attr __user *uattr,
4835 				    u32 prog_id, u32 fd_type,
4836 				    const char *buf, u64 probe_offset,
4837 				    u64 probe_addr)
4838 {
4839 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
4840 	u32 len = buf ? strlen(buf) : 0, input_len;
4841 	int err = 0;
4842 
4843 	if (put_user(len, &uattr->task_fd_query.buf_len))
4844 		return -EFAULT;
4845 	input_len = attr->task_fd_query.buf_len;
4846 	if (input_len && ubuf) {
4847 		if (!len) {
4848 			/* nothing to copy, just make ubuf NULL terminated */
4849 			char zero = '\0';
4850 
4851 			if (put_user(zero, ubuf))
4852 				return -EFAULT;
4853 		} else if (input_len >= len + 1) {
4854 			/* ubuf can hold the string with NULL terminator */
4855 			if (copy_to_user(ubuf, buf, len + 1))
4856 				return -EFAULT;
4857 		} else {
4858 			/* ubuf cannot hold the string with NULL terminator,
4859 			 * do a partial copy with NULL terminator.
4860 			 */
4861 			char zero = '\0';
4862 
4863 			err = -ENOSPC;
4864 			if (copy_to_user(ubuf, buf, input_len - 1))
4865 				return -EFAULT;
4866 			if (put_user(zero, ubuf + input_len - 1))
4867 				return -EFAULT;
4868 		}
4869 	}
4870 
4871 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
4872 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
4873 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
4874 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
4875 		return -EFAULT;
4876 
4877 	return err;
4878 }
4879 
4880 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
4881 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4882 static int bpf_task_fd_query(const union bpf_attr *attr,
4883 			     union bpf_attr __user *uattr)
4884 {
4885 	pid_t pid = attr->task_fd_query.pid;
4886 	u32 fd = attr->task_fd_query.fd;
4887 	const struct perf_event *event;
4888 	struct task_struct *task;
4889 	struct file *file;
4890 	int err;
4891 
4892 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
4893 		return -EINVAL;
4894 
4895 	if (!capable(CAP_SYS_ADMIN))
4896 		return -EPERM;
4897 
4898 	if (attr->task_fd_query.flags != 0)
4899 		return -EINVAL;
4900 
4901 	rcu_read_lock();
4902 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
4903 	rcu_read_unlock();
4904 	if (!task)
4905 		return -ENOENT;
4906 
4907 	err = 0;
4908 	file = fget_task(task, fd);
4909 	put_task_struct(task);
4910 	if (!file)
4911 		return -EBADF;
4912 
4913 	if (file->f_op == &bpf_link_fops) {
4914 		struct bpf_link *link = file->private_data;
4915 
4916 		if (link->ops == &bpf_raw_tp_link_lops) {
4917 			struct bpf_raw_tp_link *raw_tp =
4918 				container_of(link, struct bpf_raw_tp_link, link);
4919 			struct bpf_raw_event_map *btp = raw_tp->btp;
4920 
4921 			err = bpf_task_fd_query_copy(attr, uattr,
4922 						     raw_tp->link.prog->aux->id,
4923 						     BPF_FD_TYPE_RAW_TRACEPOINT,
4924 						     btp->tp->name, 0, 0);
4925 			goto put_file;
4926 		}
4927 		goto out_not_supp;
4928 	}
4929 
4930 	event = perf_get_event(file);
4931 	if (!IS_ERR(event)) {
4932 		u64 probe_offset, probe_addr;
4933 		u32 prog_id, fd_type;
4934 		const char *buf;
4935 
4936 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
4937 					      &buf, &probe_offset,
4938 					      &probe_addr, NULL);
4939 		if (!err)
4940 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
4941 						     fd_type, buf,
4942 						     probe_offset,
4943 						     probe_addr);
4944 		goto put_file;
4945 	}
4946 
4947 out_not_supp:
4948 	err = -ENOTSUPP;
4949 put_file:
4950 	fput(file);
4951 	return err;
4952 }
4953 
4954 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
4955 
4956 #define BPF_DO_BATCH(fn, ...)			\
4957 	do {					\
4958 		if (!fn) {			\
4959 			err = -ENOTSUPP;	\
4960 			goto err_put;		\
4961 		}				\
4962 		err = fn(__VA_ARGS__);		\
4963 	} while (0)
4964 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)4965 static int bpf_map_do_batch(const union bpf_attr *attr,
4966 			    union bpf_attr __user *uattr,
4967 			    int cmd)
4968 {
4969 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
4970 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
4971 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
4972 	struct bpf_map *map;
4973 	int err, ufd;
4974 	struct fd f;
4975 
4976 	if (CHECK_ATTR(BPF_MAP_BATCH))
4977 		return -EINVAL;
4978 
4979 	ufd = attr->batch.map_fd;
4980 	f = fdget(ufd);
4981 	map = __bpf_map_get(f);
4982 	if (IS_ERR(map))
4983 		return PTR_ERR(map);
4984 	if (has_write)
4985 		bpf_map_write_active_inc(map);
4986 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
4987 		err = -EPERM;
4988 		goto err_put;
4989 	}
4990 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
4991 		err = -EPERM;
4992 		goto err_put;
4993 	}
4994 
4995 	if (cmd == BPF_MAP_LOOKUP_BATCH)
4996 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
4997 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
4998 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
4999 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5000 		BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr);
5001 	else
5002 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5003 err_put:
5004 	if (has_write)
5005 		bpf_map_write_active_dec(map);
5006 	fdput(f);
5007 	return err;
5008 }
5009 
5010 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5011 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5012 {
5013 	struct bpf_prog *prog;
5014 	int ret;
5015 
5016 	if (CHECK_ATTR(BPF_LINK_CREATE))
5017 		return -EINVAL;
5018 
5019 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5020 		return bpf_struct_ops_link_create(attr);
5021 
5022 	prog = bpf_prog_get(attr->link_create.prog_fd);
5023 	if (IS_ERR(prog))
5024 		return PTR_ERR(prog);
5025 
5026 	ret = bpf_prog_attach_check_attach_type(prog,
5027 						attr->link_create.attach_type);
5028 	if (ret)
5029 		goto out;
5030 
5031 	switch (prog->type) {
5032 	case BPF_PROG_TYPE_CGROUP_SKB:
5033 	case BPF_PROG_TYPE_CGROUP_SOCK:
5034 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5035 	case BPF_PROG_TYPE_SOCK_OPS:
5036 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5037 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5038 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5039 		ret = cgroup_bpf_link_attach(attr, prog);
5040 		break;
5041 	case BPF_PROG_TYPE_EXT:
5042 		ret = bpf_tracing_prog_attach(prog,
5043 					      attr->link_create.target_fd,
5044 					      attr->link_create.target_btf_id,
5045 					      attr->link_create.tracing.cookie);
5046 		break;
5047 	case BPF_PROG_TYPE_LSM:
5048 	case BPF_PROG_TYPE_TRACING:
5049 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5050 			ret = -EINVAL;
5051 			goto out;
5052 		}
5053 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5054 			ret = bpf_raw_tp_link_attach(prog, NULL);
5055 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5056 			ret = bpf_iter_link_attach(attr, uattr, prog);
5057 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5058 			ret = cgroup_bpf_link_attach(attr, prog);
5059 		else
5060 			ret = bpf_tracing_prog_attach(prog,
5061 						      attr->link_create.target_fd,
5062 						      attr->link_create.target_btf_id,
5063 						      attr->link_create.tracing.cookie);
5064 		break;
5065 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5066 	case BPF_PROG_TYPE_SK_LOOKUP:
5067 		ret = netns_bpf_link_create(attr, prog);
5068 		break;
5069 #ifdef CONFIG_NET
5070 	case BPF_PROG_TYPE_XDP:
5071 		ret = bpf_xdp_link_attach(attr, prog);
5072 		break;
5073 	case BPF_PROG_TYPE_SCHED_CLS:
5074 		ret = tcx_link_attach(attr, prog);
5075 		break;
5076 	case BPF_PROG_TYPE_NETFILTER:
5077 		ret = bpf_nf_link_attach(attr, prog);
5078 		break;
5079 #endif
5080 	case BPF_PROG_TYPE_PERF_EVENT:
5081 	case BPF_PROG_TYPE_TRACEPOINT:
5082 		ret = bpf_perf_link_attach(attr, prog);
5083 		break;
5084 	case BPF_PROG_TYPE_KPROBE:
5085 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5086 			ret = bpf_perf_link_attach(attr, prog);
5087 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI)
5088 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5089 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI)
5090 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5091 		break;
5092 	default:
5093 		ret = -EINVAL;
5094 	}
5095 
5096 out:
5097 	if (ret < 0)
5098 		bpf_prog_put(prog);
5099 	return ret;
5100 }
5101 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5102 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5103 {
5104 	struct bpf_map *new_map, *old_map = NULL;
5105 	int ret;
5106 
5107 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5108 	if (IS_ERR(new_map))
5109 		return PTR_ERR(new_map);
5110 
5111 	if (attr->link_update.flags & BPF_F_REPLACE) {
5112 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5113 		if (IS_ERR(old_map)) {
5114 			ret = PTR_ERR(old_map);
5115 			goto out_put;
5116 		}
5117 	} else if (attr->link_update.old_map_fd) {
5118 		ret = -EINVAL;
5119 		goto out_put;
5120 	}
5121 
5122 	ret = link->ops->update_map(link, new_map, old_map);
5123 
5124 	if (old_map)
5125 		bpf_map_put(old_map);
5126 out_put:
5127 	bpf_map_put(new_map);
5128 	return ret;
5129 }
5130 
5131 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5132 
link_update(union bpf_attr * attr)5133 static int link_update(union bpf_attr *attr)
5134 {
5135 	struct bpf_prog *old_prog = NULL, *new_prog;
5136 	struct bpf_link *link;
5137 	u32 flags;
5138 	int ret;
5139 
5140 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5141 		return -EINVAL;
5142 
5143 	flags = attr->link_update.flags;
5144 	if (flags & ~BPF_F_REPLACE)
5145 		return -EINVAL;
5146 
5147 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5148 	if (IS_ERR(link))
5149 		return PTR_ERR(link);
5150 
5151 	if (link->ops->update_map) {
5152 		ret = link_update_map(link, attr);
5153 		goto out_put_link;
5154 	}
5155 
5156 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5157 	if (IS_ERR(new_prog)) {
5158 		ret = PTR_ERR(new_prog);
5159 		goto out_put_link;
5160 	}
5161 
5162 	if (flags & BPF_F_REPLACE) {
5163 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5164 		if (IS_ERR(old_prog)) {
5165 			ret = PTR_ERR(old_prog);
5166 			old_prog = NULL;
5167 			goto out_put_progs;
5168 		}
5169 	} else if (attr->link_update.old_prog_fd) {
5170 		ret = -EINVAL;
5171 		goto out_put_progs;
5172 	}
5173 
5174 	if (link->ops->update_prog)
5175 		ret = link->ops->update_prog(link, new_prog, old_prog);
5176 	else
5177 		ret = -EINVAL;
5178 
5179 out_put_progs:
5180 	if (old_prog)
5181 		bpf_prog_put(old_prog);
5182 	if (ret)
5183 		bpf_prog_put(new_prog);
5184 out_put_link:
5185 	bpf_link_put_direct(link);
5186 	return ret;
5187 }
5188 
5189 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5190 
link_detach(union bpf_attr * attr)5191 static int link_detach(union bpf_attr *attr)
5192 {
5193 	struct bpf_link *link;
5194 	int ret;
5195 
5196 	if (CHECK_ATTR(BPF_LINK_DETACH))
5197 		return -EINVAL;
5198 
5199 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5200 	if (IS_ERR(link))
5201 		return PTR_ERR(link);
5202 
5203 	if (link->ops->detach)
5204 		ret = link->ops->detach(link);
5205 	else
5206 		ret = -EOPNOTSUPP;
5207 
5208 	bpf_link_put_direct(link);
5209 	return ret;
5210 }
5211 
bpf_link_inc_not_zero(struct bpf_link * link)5212 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5213 {
5214 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5215 }
5216 
bpf_link_by_id(u32 id)5217 struct bpf_link *bpf_link_by_id(u32 id)
5218 {
5219 	struct bpf_link *link;
5220 
5221 	if (!id)
5222 		return ERR_PTR(-ENOENT);
5223 
5224 	spin_lock_bh(&link_idr_lock);
5225 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5226 	link = idr_find(&link_idr, id);
5227 	if (link) {
5228 		if (link->id)
5229 			link = bpf_link_inc_not_zero(link);
5230 		else
5231 			link = ERR_PTR(-EAGAIN);
5232 	} else {
5233 		link = ERR_PTR(-ENOENT);
5234 	}
5235 	spin_unlock_bh(&link_idr_lock);
5236 	return link;
5237 }
5238 
bpf_link_get_curr_or_next(u32 * id)5239 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5240 {
5241 	struct bpf_link *link;
5242 
5243 	spin_lock_bh(&link_idr_lock);
5244 again:
5245 	link = idr_get_next(&link_idr, id);
5246 	if (link) {
5247 		link = bpf_link_inc_not_zero(link);
5248 		if (IS_ERR(link)) {
5249 			(*id)++;
5250 			goto again;
5251 		}
5252 	}
5253 	spin_unlock_bh(&link_idr_lock);
5254 
5255 	return link;
5256 }
5257 
5258 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5259 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5260 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5261 {
5262 	struct bpf_link *link;
5263 	u32 id = attr->link_id;
5264 	int fd;
5265 
5266 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5267 		return -EINVAL;
5268 
5269 	if (!capable(CAP_SYS_ADMIN))
5270 		return -EPERM;
5271 
5272 	link = bpf_link_by_id(id);
5273 	if (IS_ERR(link))
5274 		return PTR_ERR(link);
5275 
5276 	fd = bpf_link_new_fd(link);
5277 	if (fd < 0)
5278 		bpf_link_put_direct(link);
5279 
5280 	return fd;
5281 }
5282 
5283 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5284 
bpf_stats_release(struct inode * inode,struct file * file)5285 static int bpf_stats_release(struct inode *inode, struct file *file)
5286 {
5287 	mutex_lock(&bpf_stats_enabled_mutex);
5288 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5289 	mutex_unlock(&bpf_stats_enabled_mutex);
5290 	return 0;
5291 }
5292 
5293 static const struct file_operations bpf_stats_fops = {
5294 	.release = bpf_stats_release,
5295 };
5296 
bpf_enable_runtime_stats(void)5297 static int bpf_enable_runtime_stats(void)
5298 {
5299 	int fd;
5300 
5301 	mutex_lock(&bpf_stats_enabled_mutex);
5302 
5303 	/* Set a very high limit to avoid overflow */
5304 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5305 		mutex_unlock(&bpf_stats_enabled_mutex);
5306 		return -EBUSY;
5307 	}
5308 
5309 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5310 	if (fd >= 0)
5311 		static_key_slow_inc(&bpf_stats_enabled_key.key);
5312 
5313 	mutex_unlock(&bpf_stats_enabled_mutex);
5314 	return fd;
5315 }
5316 
5317 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5318 
bpf_enable_stats(union bpf_attr * attr)5319 static int bpf_enable_stats(union bpf_attr *attr)
5320 {
5321 
5322 	if (CHECK_ATTR(BPF_ENABLE_STATS))
5323 		return -EINVAL;
5324 
5325 	if (!capable(CAP_SYS_ADMIN))
5326 		return -EPERM;
5327 
5328 	switch (attr->enable_stats.type) {
5329 	case BPF_STATS_RUN_TIME:
5330 		return bpf_enable_runtime_stats();
5331 	default:
5332 		break;
5333 	}
5334 	return -EINVAL;
5335 }
5336 
5337 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
5338 
bpf_iter_create(union bpf_attr * attr)5339 static int bpf_iter_create(union bpf_attr *attr)
5340 {
5341 	struct bpf_link *link;
5342 	int err;
5343 
5344 	if (CHECK_ATTR(BPF_ITER_CREATE))
5345 		return -EINVAL;
5346 
5347 	if (attr->iter_create.flags)
5348 		return -EINVAL;
5349 
5350 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
5351 	if (IS_ERR(link))
5352 		return PTR_ERR(link);
5353 
5354 	err = bpf_iter_new_fd(link);
5355 	bpf_link_put_direct(link);
5356 
5357 	return err;
5358 }
5359 
5360 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
5361 
bpf_prog_bind_map(union bpf_attr * attr)5362 static int bpf_prog_bind_map(union bpf_attr *attr)
5363 {
5364 	struct bpf_prog *prog;
5365 	struct bpf_map *map;
5366 	struct bpf_map **used_maps_old, **used_maps_new;
5367 	int i, ret = 0;
5368 
5369 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
5370 		return -EINVAL;
5371 
5372 	if (attr->prog_bind_map.flags)
5373 		return -EINVAL;
5374 
5375 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
5376 	if (IS_ERR(prog))
5377 		return PTR_ERR(prog);
5378 
5379 	map = bpf_map_get(attr->prog_bind_map.map_fd);
5380 	if (IS_ERR(map)) {
5381 		ret = PTR_ERR(map);
5382 		goto out_prog_put;
5383 	}
5384 
5385 	mutex_lock(&prog->aux->used_maps_mutex);
5386 
5387 	used_maps_old = prog->aux->used_maps;
5388 
5389 	for (i = 0; i < prog->aux->used_map_cnt; i++)
5390 		if (used_maps_old[i] == map) {
5391 			bpf_map_put(map);
5392 			goto out_unlock;
5393 		}
5394 
5395 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
5396 				      sizeof(used_maps_new[0]),
5397 				      GFP_KERNEL);
5398 	if (!used_maps_new) {
5399 		ret = -ENOMEM;
5400 		goto out_unlock;
5401 	}
5402 
5403 	/* The bpf program will not access the bpf map, but for the sake of
5404 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
5405 	 */
5406 	if (prog->aux->sleepable)
5407 		atomic64_inc(&map->sleepable_refcnt);
5408 	memcpy(used_maps_new, used_maps_old,
5409 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
5410 	used_maps_new[prog->aux->used_map_cnt] = map;
5411 
5412 	prog->aux->used_map_cnt++;
5413 	prog->aux->used_maps = used_maps_new;
5414 
5415 	kfree(used_maps_old);
5416 
5417 out_unlock:
5418 	mutex_unlock(&prog->aux->used_maps_mutex);
5419 
5420 	if (ret)
5421 		bpf_map_put(map);
5422 out_prog_put:
5423 	bpf_prog_put(prog);
5424 	return ret;
5425 }
5426 
__sys_bpf(int cmd,bpfptr_t uattr,unsigned int size)5427 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
5428 {
5429 	union bpf_attr attr;
5430 	int err;
5431 
5432 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
5433 	if (err)
5434 		return err;
5435 	size = min_t(u32, size, sizeof(attr));
5436 
5437 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
5438 	memset(&attr, 0, sizeof(attr));
5439 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
5440 		return -EFAULT;
5441 
5442 	err = security_bpf(cmd, &attr, size);
5443 	if (err < 0)
5444 		return err;
5445 
5446 	switch (cmd) {
5447 	case BPF_MAP_CREATE:
5448 		err = map_create(&attr);
5449 		break;
5450 	case BPF_MAP_LOOKUP_ELEM:
5451 		err = map_lookup_elem(&attr);
5452 		break;
5453 	case BPF_MAP_UPDATE_ELEM:
5454 		err = map_update_elem(&attr, uattr);
5455 		break;
5456 	case BPF_MAP_DELETE_ELEM:
5457 		err = map_delete_elem(&attr, uattr);
5458 		break;
5459 	case BPF_MAP_GET_NEXT_KEY:
5460 		err = map_get_next_key(&attr);
5461 		break;
5462 	case BPF_MAP_FREEZE:
5463 		err = map_freeze(&attr);
5464 		break;
5465 	case BPF_PROG_LOAD:
5466 		err = bpf_prog_load(&attr, uattr, size);
5467 		break;
5468 	case BPF_OBJ_PIN:
5469 		err = bpf_obj_pin(&attr);
5470 		break;
5471 	case BPF_OBJ_GET:
5472 		err = bpf_obj_get(&attr);
5473 		break;
5474 	case BPF_PROG_ATTACH:
5475 		err = bpf_prog_attach(&attr);
5476 		break;
5477 	case BPF_PROG_DETACH:
5478 		err = bpf_prog_detach(&attr);
5479 		break;
5480 	case BPF_PROG_QUERY:
5481 		err = bpf_prog_query(&attr, uattr.user);
5482 		break;
5483 	case BPF_PROG_TEST_RUN:
5484 		err = bpf_prog_test_run(&attr, uattr.user);
5485 		break;
5486 	case BPF_PROG_GET_NEXT_ID:
5487 		err = bpf_obj_get_next_id(&attr, uattr.user,
5488 					  &prog_idr, &prog_idr_lock);
5489 		break;
5490 	case BPF_MAP_GET_NEXT_ID:
5491 		err = bpf_obj_get_next_id(&attr, uattr.user,
5492 					  &map_idr, &map_idr_lock);
5493 		break;
5494 	case BPF_BTF_GET_NEXT_ID:
5495 		err = bpf_obj_get_next_id(&attr, uattr.user,
5496 					  &btf_idr, &btf_idr_lock);
5497 		break;
5498 	case BPF_PROG_GET_FD_BY_ID:
5499 		err = bpf_prog_get_fd_by_id(&attr);
5500 		break;
5501 	case BPF_MAP_GET_FD_BY_ID:
5502 		err = bpf_map_get_fd_by_id(&attr);
5503 		break;
5504 	case BPF_OBJ_GET_INFO_BY_FD:
5505 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
5506 		break;
5507 	case BPF_RAW_TRACEPOINT_OPEN:
5508 		err = bpf_raw_tracepoint_open(&attr);
5509 		break;
5510 	case BPF_BTF_LOAD:
5511 		err = bpf_btf_load(&attr, uattr, size);
5512 		break;
5513 	case BPF_BTF_GET_FD_BY_ID:
5514 		err = bpf_btf_get_fd_by_id(&attr);
5515 		break;
5516 	case BPF_TASK_FD_QUERY:
5517 		err = bpf_task_fd_query(&attr, uattr.user);
5518 		break;
5519 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
5520 		err = map_lookup_and_delete_elem(&attr);
5521 		break;
5522 	case BPF_MAP_LOOKUP_BATCH:
5523 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
5524 		break;
5525 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
5526 		err = bpf_map_do_batch(&attr, uattr.user,
5527 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
5528 		break;
5529 	case BPF_MAP_UPDATE_BATCH:
5530 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
5531 		break;
5532 	case BPF_MAP_DELETE_BATCH:
5533 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
5534 		break;
5535 	case BPF_LINK_CREATE:
5536 		err = link_create(&attr, uattr);
5537 		break;
5538 	case BPF_LINK_UPDATE:
5539 		err = link_update(&attr);
5540 		break;
5541 	case BPF_LINK_GET_FD_BY_ID:
5542 		err = bpf_link_get_fd_by_id(&attr);
5543 		break;
5544 	case BPF_LINK_GET_NEXT_ID:
5545 		err = bpf_obj_get_next_id(&attr, uattr.user,
5546 					  &link_idr, &link_idr_lock);
5547 		break;
5548 	case BPF_ENABLE_STATS:
5549 		err = bpf_enable_stats(&attr);
5550 		break;
5551 	case BPF_ITER_CREATE:
5552 		err = bpf_iter_create(&attr);
5553 		break;
5554 	case BPF_LINK_DETACH:
5555 		err = link_detach(&attr);
5556 		break;
5557 	case BPF_PROG_BIND_MAP:
5558 		err = bpf_prog_bind_map(&attr);
5559 		break;
5560 	default:
5561 		err = -EINVAL;
5562 		break;
5563 	}
5564 
5565 	return err;
5566 }
5567 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5568 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5569 {
5570 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5571 }
5572 
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)5573 static bool syscall_prog_is_valid_access(int off, int size,
5574 					 enum bpf_access_type type,
5575 					 const struct bpf_prog *prog,
5576 					 struct bpf_insn_access_aux *info)
5577 {
5578 	if (off < 0 || off >= U16_MAX)
5579 		return false;
5580 	if (off % size != 0)
5581 		return false;
5582 	return true;
5583 }
5584 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5585 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5586 {
5587 	switch (cmd) {
5588 	case BPF_MAP_CREATE:
5589 	case BPF_MAP_DELETE_ELEM:
5590 	case BPF_MAP_UPDATE_ELEM:
5591 	case BPF_MAP_FREEZE:
5592 	case BPF_MAP_GET_FD_BY_ID:
5593 	case BPF_PROG_LOAD:
5594 	case BPF_BTF_LOAD:
5595 	case BPF_LINK_CREATE:
5596 	case BPF_RAW_TRACEPOINT_OPEN:
5597 		break;
5598 	default:
5599 		return -EINVAL;
5600 	}
5601 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5602 }
5603 
5604 
5605 /* To shut up -Wmissing-prototypes.
5606  * This function is used by the kernel light skeleton
5607  * to load bpf programs when modules are loaded or during kernel boot.
5608  * See tools/lib/bpf/skel_internal.h
5609  */
5610 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
5611 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5612 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5613 {
5614 	struct bpf_prog * __maybe_unused prog;
5615 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5616 
5617 	switch (cmd) {
5618 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5619 	case BPF_PROG_TEST_RUN:
5620 		if (attr->test.data_in || attr->test.data_out ||
5621 		    attr->test.ctx_out || attr->test.duration ||
5622 		    attr->test.repeat || attr->test.flags)
5623 			return -EINVAL;
5624 
5625 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5626 		if (IS_ERR(prog))
5627 			return PTR_ERR(prog);
5628 
5629 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
5630 		    attr->test.ctx_size_in > U16_MAX) {
5631 			bpf_prog_put(prog);
5632 			return -EINVAL;
5633 		}
5634 
5635 		run_ctx.bpf_cookie = 0;
5636 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
5637 			/* recursion detected */
5638 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
5639 			bpf_prog_put(prog);
5640 			return -EBUSY;
5641 		}
5642 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
5643 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
5644 						&run_ctx);
5645 		bpf_prog_put(prog);
5646 		return 0;
5647 #endif
5648 	default:
5649 		return ____bpf_sys_bpf(cmd, attr, size);
5650 	}
5651 }
5652 EXPORT_SYMBOL(kern_sys_bpf);
5653 
5654 static const struct bpf_func_proto bpf_sys_bpf_proto = {
5655 	.func		= bpf_sys_bpf,
5656 	.gpl_only	= false,
5657 	.ret_type	= RET_INTEGER,
5658 	.arg1_type	= ARG_ANYTHING,
5659 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
5660 	.arg3_type	= ARG_CONST_SIZE,
5661 };
5662 
5663 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5664 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5665 {
5666 	return bpf_base_func_proto(func_id);
5667 }
5668 
BPF_CALL_1(bpf_sys_close,u32,fd)5669 BPF_CALL_1(bpf_sys_close, u32, fd)
5670 {
5671 	/* When bpf program calls this helper there should not be
5672 	 * an fdget() without matching completed fdput().
5673 	 * This helper is allowed in the following callchain only:
5674 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
5675 	 */
5676 	return close_fd(fd);
5677 }
5678 
5679 static const struct bpf_func_proto bpf_sys_close_proto = {
5680 	.func		= bpf_sys_close,
5681 	.gpl_only	= false,
5682 	.ret_type	= RET_INTEGER,
5683 	.arg1_type	= ARG_ANYTHING,
5684 };
5685 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)5686 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
5687 {
5688 	*res = 0;
5689 	if (flags)
5690 		return -EINVAL;
5691 
5692 	if (name_sz <= 1 || name[name_sz - 1])
5693 		return -EINVAL;
5694 
5695 	if (!bpf_dump_raw_ok(current_cred()))
5696 		return -EPERM;
5697 
5698 	*res = kallsyms_lookup_name(name);
5699 	return *res ? 0 : -ENOENT;
5700 }
5701 
5702 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
5703 	.func		= bpf_kallsyms_lookup_name,
5704 	.gpl_only	= false,
5705 	.ret_type	= RET_INTEGER,
5706 	.arg1_type	= ARG_PTR_TO_MEM,
5707 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
5708 	.arg3_type	= ARG_ANYTHING,
5709 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
5710 	.arg4_size	= sizeof(u64),
5711 };
5712 
5713 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5714 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5715 {
5716 	switch (func_id) {
5717 	case BPF_FUNC_sys_bpf:
5718 		return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto;
5719 	case BPF_FUNC_btf_find_by_name_kind:
5720 		return &bpf_btf_find_by_name_kind_proto;
5721 	case BPF_FUNC_sys_close:
5722 		return &bpf_sys_close_proto;
5723 	case BPF_FUNC_kallsyms_lookup_name:
5724 		return &bpf_kallsyms_lookup_name_proto;
5725 	default:
5726 		return tracing_prog_func_proto(func_id, prog);
5727 	}
5728 }
5729 
5730 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
5731 	.get_func_proto  = syscall_prog_func_proto,
5732 	.is_valid_access = syscall_prog_is_valid_access,
5733 };
5734 
5735 const struct bpf_prog_ops bpf_syscall_prog_ops = {
5736 	.test_run = bpf_prog_test_run_syscall,
5737 };
5738 
5739 #ifdef CONFIG_SYSCTL
bpf_stats_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5740 static int bpf_stats_handler(struct ctl_table *table, int write,
5741 			     void *buffer, size_t *lenp, loff_t *ppos)
5742 {
5743 	struct static_key *key = (struct static_key *)table->data;
5744 	static int saved_val;
5745 	int val, ret;
5746 	struct ctl_table tmp = {
5747 		.data   = &val,
5748 		.maxlen = sizeof(val),
5749 		.mode   = table->mode,
5750 		.extra1 = SYSCTL_ZERO,
5751 		.extra2 = SYSCTL_ONE,
5752 	};
5753 
5754 	if (write && !capable(CAP_SYS_ADMIN))
5755 		return -EPERM;
5756 
5757 	mutex_lock(&bpf_stats_enabled_mutex);
5758 	val = saved_val;
5759 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
5760 	if (write && !ret && val != saved_val) {
5761 		if (val)
5762 			static_key_slow_inc(key);
5763 		else
5764 			static_key_slow_dec(key);
5765 		saved_val = val;
5766 	}
5767 	mutex_unlock(&bpf_stats_enabled_mutex);
5768 	return ret;
5769 }
5770 
unpriv_ebpf_notify(int new_state)5771 void __weak unpriv_ebpf_notify(int new_state)
5772 {
5773 }
5774 
bpf_unpriv_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5775 static int bpf_unpriv_handler(struct ctl_table *table, int write,
5776 			      void *buffer, size_t *lenp, loff_t *ppos)
5777 {
5778 	int ret, unpriv_enable = *(int *)table->data;
5779 	bool locked_state = unpriv_enable == 1;
5780 	struct ctl_table tmp = *table;
5781 
5782 	if (write && !capable(CAP_SYS_ADMIN))
5783 		return -EPERM;
5784 
5785 	tmp.data = &unpriv_enable;
5786 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
5787 	if (write && !ret) {
5788 		if (locked_state && unpriv_enable != 1)
5789 			return -EPERM;
5790 		*(int *)table->data = unpriv_enable;
5791 	}
5792 
5793 	if (write)
5794 		unpriv_ebpf_notify(unpriv_enable);
5795 
5796 	return ret;
5797 }
5798 
5799 static struct ctl_table bpf_syscall_table[] = {
5800 	{
5801 		.procname	= "unprivileged_bpf_disabled",
5802 		.data		= &sysctl_unprivileged_bpf_disabled,
5803 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
5804 		.mode		= 0644,
5805 		.proc_handler	= bpf_unpriv_handler,
5806 		.extra1		= SYSCTL_ZERO,
5807 		.extra2		= SYSCTL_TWO,
5808 	},
5809 	{
5810 		.procname	= "bpf_stats_enabled",
5811 		.data		= &bpf_stats_enabled_key.key,
5812 		.mode		= 0644,
5813 		.proc_handler	= bpf_stats_handler,
5814 	},
5815 	{ }
5816 };
5817 
bpf_syscall_sysctl_init(void)5818 static int __init bpf_syscall_sysctl_init(void)
5819 {
5820 	register_sysctl_init("kernel", bpf_syscall_table);
5821 	return 0;
5822 }
5823 late_initcall(bpf_syscall_sysctl_init);
5824 #endif /* CONFIG_SYSCTL */
5825