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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 						tr_link->tgt_prog));
3113 
3114 	bpf_trampoline_put(tr_link->trampoline);
3115 
3116 	/* tgt_prog is NULL if target is a kernel function */
3117 	if (tr_link->tgt_prog)
3118 		bpf_prog_put(tr_link->tgt_prog);
3119 }
3120 
bpf_tracing_link_dealloc(struct bpf_link * link)3121 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3122 {
3123 	struct bpf_tracing_link *tr_link =
3124 		container_of(link, struct bpf_tracing_link, link.link);
3125 
3126 	kfree(tr_link);
3127 }
3128 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3129 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3130 					 struct seq_file *seq)
3131 {
3132 	struct bpf_tracing_link *tr_link =
3133 		container_of(link, struct bpf_tracing_link, link.link);
3134 	u32 target_btf_id, target_obj_id;
3135 
3136 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3137 				  &target_obj_id, &target_btf_id);
3138 	seq_printf(seq,
3139 		   "attach_type:\t%d\n"
3140 		   "target_obj_id:\t%u\n"
3141 		   "target_btf_id:\t%u\n",
3142 		   tr_link->attach_type,
3143 		   target_obj_id,
3144 		   target_btf_id);
3145 }
3146 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3147 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3148 					   struct bpf_link_info *info)
3149 {
3150 	struct bpf_tracing_link *tr_link =
3151 		container_of(link, struct bpf_tracing_link, link.link);
3152 
3153 	info->tracing.attach_type = tr_link->attach_type;
3154 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3155 				  &info->tracing.target_obj_id,
3156 				  &info->tracing.target_btf_id);
3157 
3158 	return 0;
3159 }
3160 
3161 static const struct bpf_link_ops bpf_tracing_link_lops = {
3162 	.release = bpf_tracing_link_release,
3163 	.dealloc = bpf_tracing_link_dealloc,
3164 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3165 	.fill_link_info = bpf_tracing_link_fill_link_info,
3166 };
3167 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)3168 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3169 				   int tgt_prog_fd,
3170 				   u32 btf_id,
3171 				   u64 bpf_cookie)
3172 {
3173 	struct bpf_link_primer link_primer;
3174 	struct bpf_prog *tgt_prog = NULL;
3175 	struct bpf_trampoline *tr = NULL;
3176 	struct bpf_tracing_link *link;
3177 	u64 key = 0;
3178 	int err;
3179 
3180 	switch (prog->type) {
3181 	case BPF_PROG_TYPE_TRACING:
3182 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3183 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3184 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3185 			err = -EINVAL;
3186 			goto out_put_prog;
3187 		}
3188 		break;
3189 	case BPF_PROG_TYPE_EXT:
3190 		if (prog->expected_attach_type != 0) {
3191 			err = -EINVAL;
3192 			goto out_put_prog;
3193 		}
3194 		break;
3195 	case BPF_PROG_TYPE_LSM:
3196 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3197 			err = -EINVAL;
3198 			goto out_put_prog;
3199 		}
3200 		break;
3201 	default:
3202 		err = -EINVAL;
3203 		goto out_put_prog;
3204 	}
3205 
3206 	if (!!tgt_prog_fd != !!btf_id) {
3207 		err = -EINVAL;
3208 		goto out_put_prog;
3209 	}
3210 
3211 	if (tgt_prog_fd) {
3212 		/* For now we only allow new targets for BPF_PROG_TYPE_EXT */
3213 		if (prog->type != BPF_PROG_TYPE_EXT) {
3214 			err = -EINVAL;
3215 			goto out_put_prog;
3216 		}
3217 
3218 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3219 		if (IS_ERR(tgt_prog)) {
3220 			err = PTR_ERR(tgt_prog);
3221 			tgt_prog = NULL;
3222 			goto out_put_prog;
3223 		}
3224 
3225 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3226 	}
3227 
3228 	link = kzalloc(sizeof(*link), GFP_USER);
3229 	if (!link) {
3230 		err = -ENOMEM;
3231 		goto out_put_prog;
3232 	}
3233 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3234 		      &bpf_tracing_link_lops, prog);
3235 	link->attach_type = prog->expected_attach_type;
3236 	link->link.cookie = bpf_cookie;
3237 
3238 	mutex_lock(&prog->aux->dst_mutex);
3239 
3240 	/* There are a few possible cases here:
3241 	 *
3242 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3243 	 *   and not yet attached to anything, so we can use the values stored
3244 	 *   in prog->aux
3245 	 *
3246 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3247 	 *   attached to a target and its initial target was cleared (below)
3248 	 *
3249 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3250 	 *   target_btf_id using the link_create API.
3251 	 *
3252 	 * - if tgt_prog == NULL when this function was called using the old
3253 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3254 	 *
3255 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3256 	 *   was detached and is going for re-attachment.
3257 	 *
3258 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3259 	 *   are NULL, then program was already attached and user did not provide
3260 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3261 	 */
3262 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3263 		/*
3264 		 * Allow re-attach for TRACING and LSM programs. If it's
3265 		 * currently linked, bpf_trampoline_link_prog will fail.
3266 		 * EXT programs need to specify tgt_prog_fd, so they
3267 		 * re-attach in separate code path.
3268 		 */
3269 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3270 		    prog->type != BPF_PROG_TYPE_LSM) {
3271 			err = -EINVAL;
3272 			goto out_unlock;
3273 		}
3274 		/* We can allow re-attach only if we have valid attach_btf. */
3275 		if (!prog->aux->attach_btf) {
3276 			err = -EINVAL;
3277 			goto out_unlock;
3278 		}
3279 		btf_id = prog->aux->attach_btf_id;
3280 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3281 	}
3282 
3283 	if (!prog->aux->dst_trampoline ||
3284 	    (key && key != prog->aux->dst_trampoline->key)) {
3285 		/* If there is no saved target, or the specified target is
3286 		 * different from the destination specified at load time, we
3287 		 * need a new trampoline and a check for compatibility
3288 		 */
3289 		struct bpf_attach_target_info tgt_info = {};
3290 
3291 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3292 					      &tgt_info);
3293 		if (err)
3294 			goto out_unlock;
3295 
3296 		if (tgt_info.tgt_mod) {
3297 			module_put(prog->aux->mod);
3298 			prog->aux->mod = tgt_info.tgt_mod;
3299 		}
3300 
3301 		tr = bpf_trampoline_get(key, &tgt_info);
3302 		if (!tr) {
3303 			err = -ENOMEM;
3304 			goto out_unlock;
3305 		}
3306 	} else {
3307 		/* The caller didn't specify a target, or the target was the
3308 		 * same as the destination supplied during program load. This
3309 		 * means we can reuse the trampoline and reference from program
3310 		 * load time, and there is no need to allocate a new one. This
3311 		 * can only happen once for any program, as the saved values in
3312 		 * prog->aux are cleared below.
3313 		 */
3314 		tr = prog->aux->dst_trampoline;
3315 		tgt_prog = prog->aux->dst_prog;
3316 	}
3317 
3318 	err = bpf_link_prime(&link->link.link, &link_primer);
3319 	if (err)
3320 		goto out_unlock;
3321 
3322 	err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3323 	if (err) {
3324 		bpf_link_cleanup(&link_primer);
3325 		link = NULL;
3326 		goto out_unlock;
3327 	}
3328 
3329 	link->tgt_prog = tgt_prog;
3330 	link->trampoline = tr;
3331 
3332 	/* Always clear the trampoline and target prog from prog->aux to make
3333 	 * sure the original attach destination is not kept alive after a
3334 	 * program is (re-)attached to another target.
3335 	 */
3336 	if (prog->aux->dst_prog &&
3337 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3338 		/* got extra prog ref from syscall, or attaching to different prog */
3339 		bpf_prog_put(prog->aux->dst_prog);
3340 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3341 		/* we allocated a new trampoline, so free the old one */
3342 		bpf_trampoline_put(prog->aux->dst_trampoline);
3343 
3344 	prog->aux->dst_prog = NULL;
3345 	prog->aux->dst_trampoline = NULL;
3346 	mutex_unlock(&prog->aux->dst_mutex);
3347 
3348 	return bpf_link_settle(&link_primer);
3349 out_unlock:
3350 	if (tr && tr != prog->aux->dst_trampoline)
3351 		bpf_trampoline_put(tr);
3352 	mutex_unlock(&prog->aux->dst_mutex);
3353 	kfree(link);
3354 out_put_prog:
3355 	if (tgt_prog_fd && tgt_prog)
3356 		bpf_prog_put(tgt_prog);
3357 	return err;
3358 }
3359 
3360 struct bpf_raw_tp_link {
3361 	struct bpf_link link;
3362 	struct bpf_raw_event_map *btp;
3363 };
3364 
bpf_raw_tp_link_release(struct bpf_link * link)3365 static void bpf_raw_tp_link_release(struct bpf_link *link)
3366 {
3367 	struct bpf_raw_tp_link *raw_tp =
3368 		container_of(link, struct bpf_raw_tp_link, link);
3369 
3370 	bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
3371 	bpf_put_raw_tracepoint(raw_tp->btp);
3372 }
3373 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3374 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3375 {
3376 	struct bpf_raw_tp_link *raw_tp =
3377 		container_of(link, struct bpf_raw_tp_link, link);
3378 
3379 	kfree(raw_tp);
3380 }
3381 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3382 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3383 					struct seq_file *seq)
3384 {
3385 	struct bpf_raw_tp_link *raw_tp_link =
3386 		container_of(link, struct bpf_raw_tp_link, link);
3387 
3388 	seq_printf(seq,
3389 		   "tp_name:\t%s\n",
3390 		   raw_tp_link->btp->tp->name);
3391 }
3392 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3393 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3394 			    u32 len)
3395 {
3396 	if (ulen >= len + 1) {
3397 		if (copy_to_user(ubuf, buf, len + 1))
3398 			return -EFAULT;
3399 	} else {
3400 		char zero = '\0';
3401 
3402 		if (copy_to_user(ubuf, buf, ulen - 1))
3403 			return -EFAULT;
3404 		if (put_user(zero, ubuf + ulen - 1))
3405 			return -EFAULT;
3406 		return -ENOSPC;
3407 	}
3408 
3409 	return 0;
3410 }
3411 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3412 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3413 					  struct bpf_link_info *info)
3414 {
3415 	struct bpf_raw_tp_link *raw_tp_link =
3416 		container_of(link, struct bpf_raw_tp_link, link);
3417 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3418 	const char *tp_name = raw_tp_link->btp->tp->name;
3419 	u32 ulen = info->raw_tracepoint.tp_name_len;
3420 	size_t tp_len = strlen(tp_name);
3421 
3422 	if (!ulen ^ !ubuf)
3423 		return -EINVAL;
3424 
3425 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3426 
3427 	if (!ubuf)
3428 		return 0;
3429 
3430 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3431 }
3432 
3433 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3434 	.release = bpf_raw_tp_link_release,
3435 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3436 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3437 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3438 };
3439 
3440 #ifdef CONFIG_PERF_EVENTS
3441 struct bpf_perf_link {
3442 	struct bpf_link link;
3443 	struct file *perf_file;
3444 };
3445 
bpf_perf_link_release(struct bpf_link * link)3446 static void bpf_perf_link_release(struct bpf_link *link)
3447 {
3448 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3449 	struct perf_event *event = perf_link->perf_file->private_data;
3450 
3451 	perf_event_free_bpf_prog(event);
3452 	fput(perf_link->perf_file);
3453 }
3454 
bpf_perf_link_dealloc(struct bpf_link * link)3455 static void bpf_perf_link_dealloc(struct bpf_link *link)
3456 {
3457 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3458 
3459 	kfree(perf_link);
3460 }
3461 
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)3462 static int bpf_perf_link_fill_common(const struct perf_event *event,
3463 				     char __user *uname, u32 *ulenp,
3464 				     u64 *probe_offset, u64 *probe_addr,
3465 				     u32 *fd_type, unsigned long *missed)
3466 {
3467 	const char *buf;
3468 	u32 prog_id, ulen;
3469 	size_t len;
3470 	int err;
3471 
3472 	ulen = *ulenp;
3473 	if (!ulen ^ !uname)
3474 		return -EINVAL;
3475 
3476 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3477 				      probe_offset, probe_addr, missed);
3478 	if (err)
3479 		return err;
3480 
3481 	if (buf) {
3482 		len = strlen(buf);
3483 		*ulenp = len + 1;
3484 	} else {
3485 		*ulenp = 1;
3486 	}
3487 	if (!uname)
3488 		return 0;
3489 
3490 	if (buf) {
3491 		err = bpf_copy_to_user(uname, buf, ulen, len);
3492 		if (err)
3493 			return err;
3494 	} else {
3495 		char zero = '\0';
3496 
3497 		if (put_user(zero, uname))
3498 			return -EFAULT;
3499 	}
3500 	return 0;
3501 }
3502 
3503 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3504 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3505 				     struct bpf_link_info *info)
3506 {
3507 	unsigned long missed;
3508 	char __user *uname;
3509 	u64 addr, offset;
3510 	u32 ulen, type;
3511 	int err;
3512 
3513 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3514 	ulen = info->perf_event.kprobe.name_len;
3515 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3516 					&type, &missed);
3517 	if (err)
3518 		return err;
3519 	if (type == BPF_FD_TYPE_KRETPROBE)
3520 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3521 	else
3522 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3523 	info->perf_event.kprobe.name_len = ulen;
3524 	info->perf_event.kprobe.offset = offset;
3525 	info->perf_event.kprobe.missed = missed;
3526 	if (!kallsyms_show_value(current_cred()))
3527 		addr = 0;
3528 	info->perf_event.kprobe.addr = addr;
3529 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3530 	return 0;
3531 }
3532 #endif
3533 
3534 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3535 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3536 				     struct bpf_link_info *info)
3537 {
3538 	char __user *uname;
3539 	u64 addr, offset;
3540 	u32 ulen, type;
3541 	int err;
3542 
3543 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3544 	ulen = info->perf_event.uprobe.name_len;
3545 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3546 					&type, NULL);
3547 	if (err)
3548 		return err;
3549 
3550 	if (type == BPF_FD_TYPE_URETPROBE)
3551 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3552 	else
3553 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3554 	info->perf_event.uprobe.name_len = ulen;
3555 	info->perf_event.uprobe.offset = offset;
3556 	info->perf_event.uprobe.cookie = event->bpf_cookie;
3557 	return 0;
3558 }
3559 #endif
3560 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)3561 static int bpf_perf_link_fill_probe(const struct perf_event *event,
3562 				    struct bpf_link_info *info)
3563 {
3564 #ifdef CONFIG_KPROBE_EVENTS
3565 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
3566 		return bpf_perf_link_fill_kprobe(event, info);
3567 #endif
3568 #ifdef CONFIG_UPROBE_EVENTS
3569 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
3570 		return bpf_perf_link_fill_uprobe(event, info);
3571 #endif
3572 	return -EOPNOTSUPP;
3573 }
3574 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)3575 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
3576 					 struct bpf_link_info *info)
3577 {
3578 	char __user *uname;
3579 	u32 ulen;
3580 	int err;
3581 
3582 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
3583 	ulen = info->perf_event.tracepoint.name_len;
3584 	err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
3585 	if (err)
3586 		return err;
3587 
3588 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
3589 	info->perf_event.tracepoint.name_len = ulen;
3590 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
3591 	return 0;
3592 }
3593 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)3594 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
3595 					 struct bpf_link_info *info)
3596 {
3597 	info->perf_event.event.type = event->attr.type;
3598 	info->perf_event.event.config = event->attr.config;
3599 	info->perf_event.event.cookie = event->bpf_cookie;
3600 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
3601 	return 0;
3602 }
3603 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3604 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
3605 					struct bpf_link_info *info)
3606 {
3607 	struct bpf_perf_link *perf_link;
3608 	const struct perf_event *event;
3609 
3610 	perf_link = container_of(link, struct bpf_perf_link, link);
3611 	event = perf_get_event(perf_link->perf_file);
3612 	if (IS_ERR(event))
3613 		return PTR_ERR(event);
3614 
3615 	switch (event->prog->type) {
3616 	case BPF_PROG_TYPE_PERF_EVENT:
3617 		return bpf_perf_link_fill_perf_event(event, info);
3618 	case BPF_PROG_TYPE_TRACEPOINT:
3619 		return bpf_perf_link_fill_tracepoint(event, info);
3620 	case BPF_PROG_TYPE_KPROBE:
3621 		return bpf_perf_link_fill_probe(event, info);
3622 	default:
3623 		return -EOPNOTSUPP;
3624 	}
3625 }
3626 
3627 static const struct bpf_link_ops bpf_perf_link_lops = {
3628 	.release = bpf_perf_link_release,
3629 	.dealloc = bpf_perf_link_dealloc,
3630 	.fill_link_info = bpf_perf_link_fill_link_info,
3631 };
3632 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3633 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3634 {
3635 	struct bpf_link_primer link_primer;
3636 	struct bpf_perf_link *link;
3637 	struct perf_event *event;
3638 	struct file *perf_file;
3639 	int err;
3640 
3641 	if (attr->link_create.flags)
3642 		return -EINVAL;
3643 
3644 	perf_file = perf_event_get(attr->link_create.target_fd);
3645 	if (IS_ERR(perf_file))
3646 		return PTR_ERR(perf_file);
3647 
3648 	link = kzalloc(sizeof(*link), GFP_USER);
3649 	if (!link) {
3650 		err = -ENOMEM;
3651 		goto out_put_file;
3652 	}
3653 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3654 	link->perf_file = perf_file;
3655 
3656 	err = bpf_link_prime(&link->link, &link_primer);
3657 	if (err) {
3658 		kfree(link);
3659 		goto out_put_file;
3660 	}
3661 
3662 	event = perf_file->private_data;
3663 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3664 	if (err) {
3665 		bpf_link_cleanup(&link_primer);
3666 		goto out_put_file;
3667 	}
3668 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3669 	bpf_prog_inc(prog);
3670 
3671 	return bpf_link_settle(&link_primer);
3672 
3673 out_put_file:
3674 	fput(perf_file);
3675 	return err;
3676 }
3677 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3678 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3679 {
3680 	return -EOPNOTSUPP;
3681 }
3682 #endif /* CONFIG_PERF_EVENTS */
3683 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name)3684 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3685 				  const char __user *user_tp_name)
3686 {
3687 	struct bpf_link_primer link_primer;
3688 	struct bpf_raw_tp_link *link;
3689 	struct bpf_raw_event_map *btp;
3690 	const char *tp_name;
3691 	char buf[128];
3692 	int err;
3693 
3694 	switch (prog->type) {
3695 	case BPF_PROG_TYPE_TRACING:
3696 	case BPF_PROG_TYPE_EXT:
3697 	case BPF_PROG_TYPE_LSM:
3698 		if (user_tp_name)
3699 			/* The attach point for this category of programs
3700 			 * should be specified via btf_id during program load.
3701 			 */
3702 			return -EINVAL;
3703 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3704 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3705 			tp_name = prog->aux->attach_func_name;
3706 			break;
3707 		}
3708 		return bpf_tracing_prog_attach(prog, 0, 0, 0);
3709 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3710 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3711 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3712 			return -EFAULT;
3713 		buf[sizeof(buf) - 1] = 0;
3714 		tp_name = buf;
3715 		break;
3716 	default:
3717 		return -EINVAL;
3718 	}
3719 
3720 	btp = bpf_get_raw_tracepoint(tp_name);
3721 	if (!btp)
3722 		return -ENOENT;
3723 
3724 	link = kzalloc(sizeof(*link), GFP_USER);
3725 	if (!link) {
3726 		err = -ENOMEM;
3727 		goto out_put_btp;
3728 	}
3729 	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3730 		      &bpf_raw_tp_link_lops, prog);
3731 	link->btp = btp;
3732 
3733 	err = bpf_link_prime(&link->link, &link_primer);
3734 	if (err) {
3735 		kfree(link);
3736 		goto out_put_btp;
3737 	}
3738 
3739 	err = bpf_probe_register(link->btp, prog);
3740 	if (err) {
3741 		bpf_link_cleanup(&link_primer);
3742 		goto out_put_btp;
3743 	}
3744 
3745 	return bpf_link_settle(&link_primer);
3746 
3747 out_put_btp:
3748 	bpf_put_raw_tracepoint(btp);
3749 	return err;
3750 }
3751 
3752 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
3753 
bpf_raw_tracepoint_open(const union bpf_attr * attr)3754 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
3755 {
3756 	struct bpf_prog *prog;
3757 	int fd;
3758 
3759 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
3760 		return -EINVAL;
3761 
3762 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
3763 	if (IS_ERR(prog))
3764 		return PTR_ERR(prog);
3765 
3766 	fd = bpf_raw_tp_link_attach(prog, u64_to_user_ptr(attr->raw_tracepoint.name));
3767 	if (fd < 0)
3768 		bpf_prog_put(prog);
3769 	return fd;
3770 }
3771 
3772 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)3773 attach_type_to_prog_type(enum bpf_attach_type attach_type)
3774 {
3775 	switch (attach_type) {
3776 	case BPF_CGROUP_INET_INGRESS:
3777 	case BPF_CGROUP_INET_EGRESS:
3778 		return BPF_PROG_TYPE_CGROUP_SKB;
3779 	case BPF_CGROUP_INET_SOCK_CREATE:
3780 	case BPF_CGROUP_INET_SOCK_RELEASE:
3781 	case BPF_CGROUP_INET4_POST_BIND:
3782 	case BPF_CGROUP_INET6_POST_BIND:
3783 		return BPF_PROG_TYPE_CGROUP_SOCK;
3784 	case BPF_CGROUP_INET4_BIND:
3785 	case BPF_CGROUP_INET6_BIND:
3786 	case BPF_CGROUP_INET4_CONNECT:
3787 	case BPF_CGROUP_INET6_CONNECT:
3788 	case BPF_CGROUP_INET4_GETPEERNAME:
3789 	case BPF_CGROUP_INET6_GETPEERNAME:
3790 	case BPF_CGROUP_INET4_GETSOCKNAME:
3791 	case BPF_CGROUP_INET6_GETSOCKNAME:
3792 	case BPF_CGROUP_UDP4_SENDMSG:
3793 	case BPF_CGROUP_UDP6_SENDMSG:
3794 	case BPF_CGROUP_UDP4_RECVMSG:
3795 	case BPF_CGROUP_UDP6_RECVMSG:
3796 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
3797 	case BPF_CGROUP_SOCK_OPS:
3798 		return BPF_PROG_TYPE_SOCK_OPS;
3799 	case BPF_CGROUP_DEVICE:
3800 		return BPF_PROG_TYPE_CGROUP_DEVICE;
3801 	case BPF_SK_MSG_VERDICT:
3802 		return BPF_PROG_TYPE_SK_MSG;
3803 	case BPF_SK_SKB_STREAM_PARSER:
3804 	case BPF_SK_SKB_STREAM_VERDICT:
3805 	case BPF_SK_SKB_VERDICT:
3806 		return BPF_PROG_TYPE_SK_SKB;
3807 	case BPF_LIRC_MODE2:
3808 		return BPF_PROG_TYPE_LIRC_MODE2;
3809 	case BPF_FLOW_DISSECTOR:
3810 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
3811 	case BPF_CGROUP_SYSCTL:
3812 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
3813 	case BPF_CGROUP_GETSOCKOPT:
3814 	case BPF_CGROUP_SETSOCKOPT:
3815 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
3816 	case BPF_TRACE_ITER:
3817 	case BPF_TRACE_RAW_TP:
3818 	case BPF_TRACE_FENTRY:
3819 	case BPF_TRACE_FEXIT:
3820 	case BPF_MODIFY_RETURN:
3821 		return BPF_PROG_TYPE_TRACING;
3822 	case BPF_LSM_MAC:
3823 		return BPF_PROG_TYPE_LSM;
3824 	case BPF_SK_LOOKUP:
3825 		return BPF_PROG_TYPE_SK_LOOKUP;
3826 	case BPF_XDP:
3827 		return BPF_PROG_TYPE_XDP;
3828 	case BPF_LSM_CGROUP:
3829 		return BPF_PROG_TYPE_LSM;
3830 	case BPF_TCX_INGRESS:
3831 	case BPF_TCX_EGRESS:
3832 		return BPF_PROG_TYPE_SCHED_CLS;
3833 	default:
3834 		return BPF_PROG_TYPE_UNSPEC;
3835 	}
3836 }
3837 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)3838 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
3839 					     enum bpf_attach_type attach_type)
3840 {
3841 	enum bpf_prog_type ptype;
3842 
3843 	switch (prog->type) {
3844 	case BPF_PROG_TYPE_CGROUP_SOCK:
3845 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3846 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3847 	case BPF_PROG_TYPE_SK_LOOKUP:
3848 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
3849 	case BPF_PROG_TYPE_CGROUP_SKB:
3850 		if (!capable(CAP_NET_ADMIN))
3851 			/* cg-skb progs can be loaded by unpriv user.
3852 			 * check permissions at attach time.
3853 			 */
3854 			return -EPERM;
3855 
3856 		ptype = attach_type_to_prog_type(attach_type);
3857 		if (prog->type != ptype)
3858 			return -EINVAL;
3859 
3860 		return prog->enforce_expected_attach_type &&
3861 			prog->expected_attach_type != attach_type ?
3862 			-EINVAL : 0;
3863 	case BPF_PROG_TYPE_EXT:
3864 		return 0;
3865 	case BPF_PROG_TYPE_NETFILTER:
3866 		if (attach_type != BPF_NETFILTER)
3867 			return -EINVAL;
3868 		return 0;
3869 	case BPF_PROG_TYPE_PERF_EVENT:
3870 	case BPF_PROG_TYPE_TRACEPOINT:
3871 		if (attach_type != BPF_PERF_EVENT)
3872 			return -EINVAL;
3873 		return 0;
3874 	case BPF_PROG_TYPE_KPROBE:
3875 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
3876 		    attach_type != BPF_TRACE_KPROBE_MULTI)
3877 			return -EINVAL;
3878 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
3879 		    attach_type != BPF_TRACE_UPROBE_MULTI)
3880 			return -EINVAL;
3881 		if (attach_type != BPF_PERF_EVENT &&
3882 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
3883 		    attach_type != BPF_TRACE_UPROBE_MULTI)
3884 			return -EINVAL;
3885 		return 0;
3886 	case BPF_PROG_TYPE_SCHED_CLS:
3887 		if (attach_type != BPF_TCX_INGRESS &&
3888 		    attach_type != BPF_TCX_EGRESS)
3889 			return -EINVAL;
3890 		return 0;
3891 	default:
3892 		ptype = attach_type_to_prog_type(attach_type);
3893 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
3894 			return -EINVAL;
3895 		return 0;
3896 	}
3897 }
3898 
3899 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
3900 
3901 #define BPF_F_ATTACH_MASK_BASE	\
3902 	(BPF_F_ALLOW_OVERRIDE |	\
3903 	 BPF_F_ALLOW_MULTI |	\
3904 	 BPF_F_REPLACE |	\
3905 	 BPF_F_PREORDER)
3906 
3907 #define BPF_F_ATTACH_MASK_MPROG	\
3908 	(BPF_F_REPLACE |	\
3909 	 BPF_F_BEFORE |		\
3910 	 BPF_F_AFTER |		\
3911 	 BPF_F_ID |		\
3912 	 BPF_F_LINK)
3913 
bpf_prog_attach(const union bpf_attr * attr)3914 static int bpf_prog_attach(const union bpf_attr *attr)
3915 {
3916 	enum bpf_prog_type ptype;
3917 	struct bpf_prog *prog;
3918 	int ret;
3919 
3920 	if (CHECK_ATTR(BPF_PROG_ATTACH))
3921 		return -EINVAL;
3922 
3923 	ptype = attach_type_to_prog_type(attr->attach_type);
3924 	if (ptype == BPF_PROG_TYPE_UNSPEC)
3925 		return -EINVAL;
3926 	if (bpf_mprog_supported(ptype)) {
3927 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
3928 			return -EINVAL;
3929 	} else {
3930 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
3931 			return -EINVAL;
3932 		if (attr->relative_fd ||
3933 		    attr->expected_revision)
3934 			return -EINVAL;
3935 	}
3936 
3937 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
3938 	if (IS_ERR(prog))
3939 		return PTR_ERR(prog);
3940 
3941 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
3942 		bpf_prog_put(prog);
3943 		return -EINVAL;
3944 	}
3945 
3946 	switch (ptype) {
3947 	case BPF_PROG_TYPE_SK_SKB:
3948 	case BPF_PROG_TYPE_SK_MSG:
3949 		ret = sock_map_get_from_fd(attr, prog);
3950 		break;
3951 	case BPF_PROG_TYPE_LIRC_MODE2:
3952 		ret = lirc_prog_attach(attr, prog);
3953 		break;
3954 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
3955 		ret = netns_bpf_prog_attach(attr, prog);
3956 		break;
3957 	case BPF_PROG_TYPE_CGROUP_DEVICE:
3958 	case BPF_PROG_TYPE_CGROUP_SKB:
3959 	case BPF_PROG_TYPE_CGROUP_SOCK:
3960 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3961 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3962 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
3963 	case BPF_PROG_TYPE_SOCK_OPS:
3964 	case BPF_PROG_TYPE_LSM:
3965 		if (ptype == BPF_PROG_TYPE_LSM &&
3966 		    prog->expected_attach_type != BPF_LSM_CGROUP)
3967 			ret = -EINVAL;
3968 		else
3969 			ret = cgroup_bpf_prog_attach(attr, ptype, prog);
3970 		break;
3971 	case BPF_PROG_TYPE_SCHED_CLS:
3972 		ret = tcx_prog_attach(attr, prog);
3973 		break;
3974 	default:
3975 		ret = -EINVAL;
3976 	}
3977 
3978 	if (ret)
3979 		bpf_prog_put(prog);
3980 	return ret;
3981 }
3982 
3983 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
3984 
bpf_prog_detach(const union bpf_attr * attr)3985 static int bpf_prog_detach(const union bpf_attr *attr)
3986 {
3987 	struct bpf_prog *prog = NULL;
3988 	enum bpf_prog_type ptype;
3989 	int ret;
3990 
3991 	if (CHECK_ATTR(BPF_PROG_DETACH))
3992 		return -EINVAL;
3993 
3994 	ptype = attach_type_to_prog_type(attr->attach_type);
3995 	if (bpf_mprog_supported(ptype)) {
3996 		if (ptype == BPF_PROG_TYPE_UNSPEC)
3997 			return -EINVAL;
3998 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
3999 			return -EINVAL;
4000 		if (attr->attach_bpf_fd) {
4001 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4002 			if (IS_ERR(prog))
4003 				return PTR_ERR(prog);
4004 		}
4005 	} else if (attr->attach_flags ||
4006 		   attr->relative_fd ||
4007 		   attr->expected_revision) {
4008 		return -EINVAL;
4009 	}
4010 
4011 	switch (ptype) {
4012 	case BPF_PROG_TYPE_SK_MSG:
4013 	case BPF_PROG_TYPE_SK_SKB:
4014 		ret = sock_map_prog_detach(attr, ptype);
4015 		break;
4016 	case BPF_PROG_TYPE_LIRC_MODE2:
4017 		ret = lirc_prog_detach(attr);
4018 		break;
4019 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4020 		ret = netns_bpf_prog_detach(attr, ptype);
4021 		break;
4022 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4023 	case BPF_PROG_TYPE_CGROUP_SKB:
4024 	case BPF_PROG_TYPE_CGROUP_SOCK:
4025 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4026 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4027 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4028 	case BPF_PROG_TYPE_SOCK_OPS:
4029 	case BPF_PROG_TYPE_LSM:
4030 		ret = cgroup_bpf_prog_detach(attr, ptype);
4031 		break;
4032 	case BPF_PROG_TYPE_SCHED_CLS:
4033 		ret = tcx_prog_detach(attr, prog);
4034 		break;
4035 	default:
4036 		ret = -EINVAL;
4037 	}
4038 
4039 	if (prog)
4040 		bpf_prog_put(prog);
4041 	return ret;
4042 }
4043 
4044 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4045 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4046 static int bpf_prog_query(const union bpf_attr *attr,
4047 			  union bpf_attr __user *uattr)
4048 {
4049 	if (!capable(CAP_NET_ADMIN))
4050 		return -EPERM;
4051 	if (CHECK_ATTR(BPF_PROG_QUERY))
4052 		return -EINVAL;
4053 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4054 		return -EINVAL;
4055 
4056 	switch (attr->query.attach_type) {
4057 	case BPF_CGROUP_INET_INGRESS:
4058 	case BPF_CGROUP_INET_EGRESS:
4059 	case BPF_CGROUP_INET_SOCK_CREATE:
4060 	case BPF_CGROUP_INET_SOCK_RELEASE:
4061 	case BPF_CGROUP_INET4_BIND:
4062 	case BPF_CGROUP_INET6_BIND:
4063 	case BPF_CGROUP_INET4_POST_BIND:
4064 	case BPF_CGROUP_INET6_POST_BIND:
4065 	case BPF_CGROUP_INET4_CONNECT:
4066 	case BPF_CGROUP_INET6_CONNECT:
4067 	case BPF_CGROUP_INET4_GETPEERNAME:
4068 	case BPF_CGROUP_INET6_GETPEERNAME:
4069 	case BPF_CGROUP_INET4_GETSOCKNAME:
4070 	case BPF_CGROUP_INET6_GETSOCKNAME:
4071 	case BPF_CGROUP_UDP4_SENDMSG:
4072 	case BPF_CGROUP_UDP6_SENDMSG:
4073 	case BPF_CGROUP_UDP4_RECVMSG:
4074 	case BPF_CGROUP_UDP6_RECVMSG:
4075 	case BPF_CGROUP_SOCK_OPS:
4076 	case BPF_CGROUP_DEVICE:
4077 	case BPF_CGROUP_SYSCTL:
4078 	case BPF_CGROUP_GETSOCKOPT:
4079 	case BPF_CGROUP_SETSOCKOPT:
4080 	case BPF_LSM_CGROUP:
4081 		return cgroup_bpf_prog_query(attr, uattr);
4082 	case BPF_LIRC_MODE2:
4083 		return lirc_prog_query(attr, uattr);
4084 	case BPF_FLOW_DISSECTOR:
4085 	case BPF_SK_LOOKUP:
4086 		return netns_bpf_prog_query(attr, uattr);
4087 	case BPF_SK_SKB_STREAM_PARSER:
4088 	case BPF_SK_SKB_STREAM_VERDICT:
4089 	case BPF_SK_MSG_VERDICT:
4090 	case BPF_SK_SKB_VERDICT:
4091 		return sock_map_bpf_prog_query(attr, uattr);
4092 	case BPF_TCX_INGRESS:
4093 	case BPF_TCX_EGRESS:
4094 		return tcx_prog_query(attr, uattr);
4095 	default:
4096 		return -EINVAL;
4097 	}
4098 }
4099 
4100 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4101 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4102 static int bpf_prog_test_run(const union bpf_attr *attr,
4103 			     union bpf_attr __user *uattr)
4104 {
4105 	struct bpf_prog *prog;
4106 	int ret = -ENOTSUPP;
4107 
4108 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4109 		return -EINVAL;
4110 
4111 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4112 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4113 		return -EINVAL;
4114 
4115 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4116 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4117 		return -EINVAL;
4118 
4119 	prog = bpf_prog_get(attr->test.prog_fd);
4120 	if (IS_ERR(prog))
4121 		return PTR_ERR(prog);
4122 
4123 	if (prog->aux->ops->test_run)
4124 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4125 
4126 	bpf_prog_put(prog);
4127 	return ret;
4128 }
4129 
4130 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4131 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4132 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4133 			       union bpf_attr __user *uattr,
4134 			       struct idr *idr,
4135 			       spinlock_t *lock)
4136 {
4137 	u32 next_id = attr->start_id;
4138 	int err = 0;
4139 
4140 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4141 		return -EINVAL;
4142 
4143 	if (!capable(CAP_SYS_ADMIN))
4144 		return -EPERM;
4145 
4146 	next_id++;
4147 	spin_lock_bh(lock);
4148 	if (!idr_get_next(idr, &next_id))
4149 		err = -ENOENT;
4150 	spin_unlock_bh(lock);
4151 
4152 	if (!err)
4153 		err = put_user(next_id, &uattr->next_id);
4154 
4155 	return err;
4156 }
4157 
bpf_map_get_curr_or_next(u32 * id)4158 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4159 {
4160 	struct bpf_map *map;
4161 
4162 	spin_lock_bh(&map_idr_lock);
4163 again:
4164 	map = idr_get_next(&map_idr, id);
4165 	if (map) {
4166 		map = __bpf_map_inc_not_zero(map, false);
4167 		if (IS_ERR(map)) {
4168 			(*id)++;
4169 			goto again;
4170 		}
4171 	}
4172 	spin_unlock_bh(&map_idr_lock);
4173 
4174 	return map;
4175 }
4176 
bpf_prog_get_curr_or_next(u32 * id)4177 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4178 {
4179 	struct bpf_prog *prog;
4180 
4181 	spin_lock_bh(&prog_idr_lock);
4182 again:
4183 	prog = idr_get_next(&prog_idr, id);
4184 	if (prog) {
4185 		prog = bpf_prog_inc_not_zero(prog);
4186 		if (IS_ERR(prog)) {
4187 			(*id)++;
4188 			goto again;
4189 		}
4190 	}
4191 	spin_unlock_bh(&prog_idr_lock);
4192 
4193 	return prog;
4194 }
4195 
4196 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4197 
bpf_prog_by_id(u32 id)4198 struct bpf_prog *bpf_prog_by_id(u32 id)
4199 {
4200 	struct bpf_prog *prog;
4201 
4202 	if (!id)
4203 		return ERR_PTR(-ENOENT);
4204 
4205 	spin_lock_bh(&prog_idr_lock);
4206 	prog = idr_find(&prog_idr, id);
4207 	if (prog)
4208 		prog = bpf_prog_inc_not_zero(prog);
4209 	else
4210 		prog = ERR_PTR(-ENOENT);
4211 	spin_unlock_bh(&prog_idr_lock);
4212 	return prog;
4213 }
4214 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4215 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4216 {
4217 	struct bpf_prog *prog;
4218 	u32 id = attr->prog_id;
4219 	int fd;
4220 
4221 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4222 		return -EINVAL;
4223 
4224 	if (!capable(CAP_SYS_ADMIN))
4225 		return -EPERM;
4226 
4227 	prog = bpf_prog_by_id(id);
4228 	if (IS_ERR(prog))
4229 		return PTR_ERR(prog);
4230 
4231 	fd = bpf_prog_new_fd(prog);
4232 	if (fd < 0)
4233 		bpf_prog_put(prog);
4234 
4235 	return fd;
4236 }
4237 
4238 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4239 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4240 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4241 {
4242 	struct bpf_map *map;
4243 	u32 id = attr->map_id;
4244 	int f_flags;
4245 	int fd;
4246 
4247 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4248 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4249 		return -EINVAL;
4250 
4251 	if (!capable(CAP_SYS_ADMIN))
4252 		return -EPERM;
4253 
4254 	f_flags = bpf_get_file_flag(attr->open_flags);
4255 	if (f_flags < 0)
4256 		return f_flags;
4257 
4258 	spin_lock_bh(&map_idr_lock);
4259 	map = idr_find(&map_idr, id);
4260 	if (map)
4261 		map = __bpf_map_inc_not_zero(map, true);
4262 	else
4263 		map = ERR_PTR(-ENOENT);
4264 	spin_unlock_bh(&map_idr_lock);
4265 
4266 	if (IS_ERR(map))
4267 		return PTR_ERR(map);
4268 
4269 	fd = bpf_map_new_fd(map, f_flags);
4270 	if (fd < 0)
4271 		bpf_map_put_with_uref(map);
4272 
4273 	return fd;
4274 }
4275 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4276 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4277 					      unsigned long addr, u32 *off,
4278 					      u32 *type)
4279 {
4280 	const struct bpf_map *map;
4281 	int i;
4282 
4283 	mutex_lock(&prog->aux->used_maps_mutex);
4284 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4285 		map = prog->aux->used_maps[i];
4286 		if (map == (void *)addr) {
4287 			*type = BPF_PSEUDO_MAP_FD;
4288 			goto out;
4289 		}
4290 		if (!map->ops->map_direct_value_meta)
4291 			continue;
4292 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4293 			*type = BPF_PSEUDO_MAP_VALUE;
4294 			goto out;
4295 		}
4296 	}
4297 	map = NULL;
4298 
4299 out:
4300 	mutex_unlock(&prog->aux->used_maps_mutex);
4301 	return map;
4302 }
4303 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4304 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4305 					      const struct cred *f_cred)
4306 {
4307 	const struct bpf_map *map;
4308 	struct bpf_insn *insns;
4309 	u32 off, type;
4310 	u64 imm;
4311 	u8 code;
4312 	int i;
4313 
4314 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4315 			GFP_USER);
4316 	if (!insns)
4317 		return insns;
4318 
4319 	for (i = 0; i < prog->len; i++) {
4320 		code = insns[i].code;
4321 
4322 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4323 			insns[i].code = BPF_JMP | BPF_CALL;
4324 			insns[i].imm = BPF_FUNC_tail_call;
4325 			/* fall-through */
4326 		}
4327 		if (code == (BPF_JMP | BPF_CALL) ||
4328 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4329 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4330 				insns[i].code = BPF_JMP | BPF_CALL;
4331 			if (!bpf_dump_raw_ok(f_cred))
4332 				insns[i].imm = 0;
4333 			continue;
4334 		}
4335 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4336 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4337 			continue;
4338 		}
4339 
4340 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4341 			continue;
4342 
4343 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4344 		map = bpf_map_from_imm(prog, imm, &off, &type);
4345 		if (map) {
4346 			insns[i].src_reg = type;
4347 			insns[i].imm = map->id;
4348 			insns[i + 1].imm = off;
4349 			continue;
4350 		}
4351 	}
4352 
4353 	return insns;
4354 }
4355 
set_info_rec_size(struct bpf_prog_info * info)4356 static int set_info_rec_size(struct bpf_prog_info *info)
4357 {
4358 	/*
4359 	 * Ensure info.*_rec_size is the same as kernel expected size
4360 	 *
4361 	 * or
4362 	 *
4363 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4364 	 * zero.  In this case, the kernel will set the expected
4365 	 * _rec_size back to the info.
4366 	 */
4367 
4368 	if ((info->nr_func_info || info->func_info_rec_size) &&
4369 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4370 		return -EINVAL;
4371 
4372 	if ((info->nr_line_info || info->line_info_rec_size) &&
4373 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
4374 		return -EINVAL;
4375 
4376 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4377 	    info->jited_line_info_rec_size != sizeof(__u64))
4378 		return -EINVAL;
4379 
4380 	info->func_info_rec_size = sizeof(struct bpf_func_info);
4381 	info->line_info_rec_size = sizeof(struct bpf_line_info);
4382 	info->jited_line_info_rec_size = sizeof(__u64);
4383 
4384 	return 0;
4385 }
4386 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4387 static int bpf_prog_get_info_by_fd(struct file *file,
4388 				   struct bpf_prog *prog,
4389 				   const union bpf_attr *attr,
4390 				   union bpf_attr __user *uattr)
4391 {
4392 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4393 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4394 	struct bpf_prog_info info;
4395 	u32 info_len = attr->info.info_len;
4396 	struct bpf_prog_kstats stats;
4397 	char __user *uinsns;
4398 	u32 ulen;
4399 	int err;
4400 
4401 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4402 	if (err)
4403 		return err;
4404 	info_len = min_t(u32, sizeof(info), info_len);
4405 
4406 	memset(&info, 0, sizeof(info));
4407 	if (copy_from_user(&info, uinfo, info_len))
4408 		return -EFAULT;
4409 
4410 	info.type = prog->type;
4411 	info.id = prog->aux->id;
4412 	info.load_time = prog->aux->load_time;
4413 	info.created_by_uid = from_kuid_munged(current_user_ns(),
4414 					       prog->aux->user->uid);
4415 	info.gpl_compatible = prog->gpl_compatible;
4416 
4417 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
4418 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
4419 
4420 	mutex_lock(&prog->aux->used_maps_mutex);
4421 	ulen = info.nr_map_ids;
4422 	info.nr_map_ids = prog->aux->used_map_cnt;
4423 	ulen = min_t(u32, info.nr_map_ids, ulen);
4424 	if (ulen) {
4425 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
4426 		u32 i;
4427 
4428 		for (i = 0; i < ulen; i++)
4429 			if (put_user(prog->aux->used_maps[i]->id,
4430 				     &user_map_ids[i])) {
4431 				mutex_unlock(&prog->aux->used_maps_mutex);
4432 				return -EFAULT;
4433 			}
4434 	}
4435 	mutex_unlock(&prog->aux->used_maps_mutex);
4436 
4437 	err = set_info_rec_size(&info);
4438 	if (err)
4439 		return err;
4440 
4441 	bpf_prog_get_stats(prog, &stats);
4442 	info.run_time_ns = stats.nsecs;
4443 	info.run_cnt = stats.cnt;
4444 	info.recursion_misses = stats.misses;
4445 
4446 	info.verified_insns = prog->aux->verified_insns;
4447 	if (prog->aux->btf)
4448 		info.btf_id = btf_obj_id(prog->aux->btf);
4449 
4450 	if (!bpf_capable()) {
4451 		info.jited_prog_len = 0;
4452 		info.xlated_prog_len = 0;
4453 		info.nr_jited_ksyms = 0;
4454 		info.nr_jited_func_lens = 0;
4455 		info.nr_func_info = 0;
4456 		info.nr_line_info = 0;
4457 		info.nr_jited_line_info = 0;
4458 		goto done;
4459 	}
4460 
4461 	ulen = info.xlated_prog_len;
4462 	info.xlated_prog_len = bpf_prog_insn_size(prog);
4463 	if (info.xlated_prog_len && ulen) {
4464 		struct bpf_insn *insns_sanitized;
4465 		bool fault;
4466 
4467 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
4468 			info.xlated_prog_insns = 0;
4469 			goto done;
4470 		}
4471 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
4472 		if (!insns_sanitized)
4473 			return -ENOMEM;
4474 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
4475 		ulen = min_t(u32, info.xlated_prog_len, ulen);
4476 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
4477 		kfree(insns_sanitized);
4478 		if (fault)
4479 			return -EFAULT;
4480 	}
4481 
4482 	if (bpf_prog_is_offloaded(prog->aux)) {
4483 		err = bpf_prog_offload_info_fill(&info, prog);
4484 		if (err)
4485 			return err;
4486 		goto done;
4487 	}
4488 
4489 	/* NOTE: the following code is supposed to be skipped for offload.
4490 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
4491 	 * for offload.
4492 	 */
4493 	ulen = info.jited_prog_len;
4494 	if (prog->aux->func_cnt) {
4495 		u32 i;
4496 
4497 		info.jited_prog_len = 0;
4498 		for (i = 0; i < prog->aux->func_cnt; i++)
4499 			info.jited_prog_len += prog->aux->func[i]->jited_len;
4500 	} else {
4501 		info.jited_prog_len = prog->jited_len;
4502 	}
4503 
4504 	if (info.jited_prog_len && ulen) {
4505 		if (bpf_dump_raw_ok(file->f_cred)) {
4506 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
4507 			ulen = min_t(u32, info.jited_prog_len, ulen);
4508 
4509 			/* for multi-function programs, copy the JITed
4510 			 * instructions for all the functions
4511 			 */
4512 			if (prog->aux->func_cnt) {
4513 				u32 len, free, i;
4514 				u8 *img;
4515 
4516 				free = ulen;
4517 				for (i = 0; i < prog->aux->func_cnt; i++) {
4518 					len = prog->aux->func[i]->jited_len;
4519 					len = min_t(u32, len, free);
4520 					img = (u8 *) prog->aux->func[i]->bpf_func;
4521 					if (copy_to_user(uinsns, img, len))
4522 						return -EFAULT;
4523 					uinsns += len;
4524 					free -= len;
4525 					if (!free)
4526 						break;
4527 				}
4528 			} else {
4529 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
4530 					return -EFAULT;
4531 			}
4532 		} else {
4533 			info.jited_prog_insns = 0;
4534 		}
4535 	}
4536 
4537 	ulen = info.nr_jited_ksyms;
4538 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4539 	if (ulen) {
4540 		if (bpf_dump_raw_ok(file->f_cred)) {
4541 			unsigned long ksym_addr;
4542 			u64 __user *user_ksyms;
4543 			u32 i;
4544 
4545 			/* copy the address of the kernel symbol
4546 			 * corresponding to each function
4547 			 */
4548 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4549 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4550 			if (prog->aux->func_cnt) {
4551 				for (i = 0; i < ulen; i++) {
4552 					ksym_addr = (unsigned long)
4553 						prog->aux->func[i]->bpf_func;
4554 					if (put_user((u64) ksym_addr,
4555 						     &user_ksyms[i]))
4556 						return -EFAULT;
4557 				}
4558 			} else {
4559 				ksym_addr = (unsigned long) prog->bpf_func;
4560 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
4561 					return -EFAULT;
4562 			}
4563 		} else {
4564 			info.jited_ksyms = 0;
4565 		}
4566 	}
4567 
4568 	ulen = info.nr_jited_func_lens;
4569 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4570 	if (ulen) {
4571 		if (bpf_dump_raw_ok(file->f_cred)) {
4572 			u32 __user *user_lens;
4573 			u32 func_len, i;
4574 
4575 			/* copy the JITed image lengths for each function */
4576 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4577 			user_lens = u64_to_user_ptr(info.jited_func_lens);
4578 			if (prog->aux->func_cnt) {
4579 				for (i = 0; i < ulen; i++) {
4580 					func_len =
4581 						prog->aux->func[i]->jited_len;
4582 					if (put_user(func_len, &user_lens[i]))
4583 						return -EFAULT;
4584 				}
4585 			} else {
4586 				func_len = prog->jited_len;
4587 				if (put_user(func_len, &user_lens[0]))
4588 					return -EFAULT;
4589 			}
4590 		} else {
4591 			info.jited_func_lens = 0;
4592 		}
4593 	}
4594 
4595 	info.attach_btf_id = prog->aux->attach_btf_id;
4596 	if (attach_btf)
4597 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
4598 
4599 	ulen = info.nr_func_info;
4600 	info.nr_func_info = prog->aux->func_info_cnt;
4601 	if (info.nr_func_info && ulen) {
4602 		char __user *user_finfo;
4603 
4604 		user_finfo = u64_to_user_ptr(info.func_info);
4605 		ulen = min_t(u32, info.nr_func_info, ulen);
4606 		if (copy_to_user(user_finfo, prog->aux->func_info,
4607 				 info.func_info_rec_size * ulen))
4608 			return -EFAULT;
4609 	}
4610 
4611 	ulen = info.nr_line_info;
4612 	info.nr_line_info = prog->aux->nr_linfo;
4613 	if (info.nr_line_info && ulen) {
4614 		__u8 __user *user_linfo;
4615 
4616 		user_linfo = u64_to_user_ptr(info.line_info);
4617 		ulen = min_t(u32, info.nr_line_info, ulen);
4618 		if (copy_to_user(user_linfo, prog->aux->linfo,
4619 				 info.line_info_rec_size * ulen))
4620 			return -EFAULT;
4621 	}
4622 
4623 	ulen = info.nr_jited_line_info;
4624 	if (prog->aux->jited_linfo)
4625 		info.nr_jited_line_info = prog->aux->nr_linfo;
4626 	else
4627 		info.nr_jited_line_info = 0;
4628 	if (info.nr_jited_line_info && ulen) {
4629 		if (bpf_dump_raw_ok(file->f_cred)) {
4630 			unsigned long line_addr;
4631 			__u64 __user *user_linfo;
4632 			u32 i;
4633 
4634 			user_linfo = u64_to_user_ptr(info.jited_line_info);
4635 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
4636 			for (i = 0; i < ulen; i++) {
4637 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
4638 				if (put_user((__u64)line_addr, &user_linfo[i]))
4639 					return -EFAULT;
4640 			}
4641 		} else {
4642 			info.jited_line_info = 0;
4643 		}
4644 	}
4645 
4646 	ulen = info.nr_prog_tags;
4647 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4648 	if (ulen) {
4649 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4650 		u32 i;
4651 
4652 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
4653 		ulen = min_t(u32, info.nr_prog_tags, ulen);
4654 		if (prog->aux->func_cnt) {
4655 			for (i = 0; i < ulen; i++) {
4656 				if (copy_to_user(user_prog_tags[i],
4657 						 prog->aux->func[i]->tag,
4658 						 BPF_TAG_SIZE))
4659 					return -EFAULT;
4660 			}
4661 		} else {
4662 			if (copy_to_user(user_prog_tags[0],
4663 					 prog->tag, BPF_TAG_SIZE))
4664 				return -EFAULT;
4665 		}
4666 	}
4667 
4668 done:
4669 	if (copy_to_user(uinfo, &info, info_len) ||
4670 	    put_user(info_len, &uattr->info.info_len))
4671 		return -EFAULT;
4672 
4673 	return 0;
4674 }
4675 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4676 static int bpf_map_get_info_by_fd(struct file *file,
4677 				  struct bpf_map *map,
4678 				  const union bpf_attr *attr,
4679 				  union bpf_attr __user *uattr)
4680 {
4681 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4682 	struct bpf_map_info info;
4683 	u32 info_len = attr->info.info_len;
4684 	int err;
4685 
4686 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4687 	if (err)
4688 		return err;
4689 	info_len = min_t(u32, sizeof(info), info_len);
4690 
4691 	memset(&info, 0, sizeof(info));
4692 	info.type = map->map_type;
4693 	info.id = map->id;
4694 	info.key_size = map->key_size;
4695 	info.value_size = map->value_size;
4696 	info.max_entries = map->max_entries;
4697 	info.map_flags = map->map_flags;
4698 	info.map_extra = map->map_extra;
4699 	memcpy(info.name, map->name, sizeof(map->name));
4700 
4701 	if (map->btf) {
4702 		info.btf_id = btf_obj_id(map->btf);
4703 		info.btf_key_type_id = map->btf_key_type_id;
4704 		info.btf_value_type_id = map->btf_value_type_id;
4705 	}
4706 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
4707 
4708 	if (bpf_map_is_offloaded(map)) {
4709 		err = bpf_map_offload_info_fill(&info, map);
4710 		if (err)
4711 			return err;
4712 	}
4713 
4714 	if (copy_to_user(uinfo, &info, info_len) ||
4715 	    put_user(info_len, &uattr->info.info_len))
4716 		return -EFAULT;
4717 
4718 	return 0;
4719 }
4720 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)4721 static int bpf_btf_get_info_by_fd(struct file *file,
4722 				  struct btf *btf,
4723 				  const union bpf_attr *attr,
4724 				  union bpf_attr __user *uattr)
4725 {
4726 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4727 	u32 info_len = attr->info.info_len;
4728 	int err;
4729 
4730 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
4731 	if (err)
4732 		return err;
4733 
4734 	return btf_get_info_by_fd(btf, attr, uattr);
4735 }
4736 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)4737 static int bpf_link_get_info_by_fd(struct file *file,
4738 				  struct bpf_link *link,
4739 				  const union bpf_attr *attr,
4740 				  union bpf_attr __user *uattr)
4741 {
4742 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4743 	struct bpf_link_info info;
4744 	u32 info_len = attr->info.info_len;
4745 	int err;
4746 
4747 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4748 	if (err)
4749 		return err;
4750 	info_len = min_t(u32, sizeof(info), info_len);
4751 
4752 	memset(&info, 0, sizeof(info));
4753 	if (copy_from_user(&info, uinfo, info_len))
4754 		return -EFAULT;
4755 
4756 	info.type = link->type;
4757 	info.id = link->id;
4758 	if (link->prog)
4759 		info.prog_id = link->prog->aux->id;
4760 
4761 	if (link->ops->fill_link_info) {
4762 		err = link->ops->fill_link_info(link, &info);
4763 		if (err)
4764 			return err;
4765 	}
4766 
4767 	if (copy_to_user(uinfo, &info, info_len) ||
4768 	    put_user(info_len, &uattr->info.info_len))
4769 		return -EFAULT;
4770 
4771 	return 0;
4772 }
4773 
4774 
4775 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
4776 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)4777 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
4778 				  union bpf_attr __user *uattr)
4779 {
4780 	int ufd = attr->info.bpf_fd;
4781 	struct fd f;
4782 	int err;
4783 
4784 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
4785 		return -EINVAL;
4786 
4787 	f = fdget(ufd);
4788 	if (!f.file)
4789 		return -EBADFD;
4790 
4791 	if (f.file->f_op == &bpf_prog_fops)
4792 		err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
4793 					      uattr);
4794 	else if (f.file->f_op == &bpf_map_fops)
4795 		err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
4796 					     uattr);
4797 	else if (f.file->f_op == &btf_fops)
4798 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
4799 	else if (f.file->f_op == &bpf_link_fops)
4800 		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
4801 					      attr, uattr);
4802 	else
4803 		err = -EINVAL;
4804 
4805 	fdput(f);
4806 	return err;
4807 }
4808 
4809 #define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size
4810 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)4811 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
4812 {
4813 	if (CHECK_ATTR(BPF_BTF_LOAD))
4814 		return -EINVAL;
4815 
4816 	if (!bpf_capable())
4817 		return -EPERM;
4818 
4819 	return btf_new_fd(attr, uattr, uattr_size);
4820 }
4821 
4822 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
4823 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)4824 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
4825 {
4826 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
4827 		return -EINVAL;
4828 
4829 	if (!capable(CAP_SYS_ADMIN))
4830 		return -EPERM;
4831 
4832 	return btf_get_fd_by_id(attr->btf_id);
4833 }
4834 
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)4835 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
4836 				    union bpf_attr __user *uattr,
4837 				    u32 prog_id, u32 fd_type,
4838 				    const char *buf, u64 probe_offset,
4839 				    u64 probe_addr)
4840 {
4841 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
4842 	u32 len = buf ? strlen(buf) : 0, input_len;
4843 	int err = 0;
4844 
4845 	if (put_user(len, &uattr->task_fd_query.buf_len))
4846 		return -EFAULT;
4847 	input_len = attr->task_fd_query.buf_len;
4848 	if (input_len && ubuf) {
4849 		if (!len) {
4850 			/* nothing to copy, just make ubuf NULL terminated */
4851 			char zero = '\0';
4852 
4853 			if (put_user(zero, ubuf))
4854 				return -EFAULT;
4855 		} else if (input_len >= len + 1) {
4856 			/* ubuf can hold the string with NULL terminator */
4857 			if (copy_to_user(ubuf, buf, len + 1))
4858 				return -EFAULT;
4859 		} else {
4860 			/* ubuf cannot hold the string with NULL terminator,
4861 			 * do a partial copy with NULL terminator.
4862 			 */
4863 			char zero = '\0';
4864 
4865 			err = -ENOSPC;
4866 			if (copy_to_user(ubuf, buf, input_len - 1))
4867 				return -EFAULT;
4868 			if (put_user(zero, ubuf + input_len - 1))
4869 				return -EFAULT;
4870 		}
4871 	}
4872 
4873 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
4874 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
4875 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
4876 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
4877 		return -EFAULT;
4878 
4879 	return err;
4880 }
4881 
4882 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
4883 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4884 static int bpf_task_fd_query(const union bpf_attr *attr,
4885 			     union bpf_attr __user *uattr)
4886 {
4887 	pid_t pid = attr->task_fd_query.pid;
4888 	u32 fd = attr->task_fd_query.fd;
4889 	const struct perf_event *event;
4890 	struct task_struct *task;
4891 	struct file *file;
4892 	int err;
4893 
4894 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
4895 		return -EINVAL;
4896 
4897 	if (!capable(CAP_SYS_ADMIN))
4898 		return -EPERM;
4899 
4900 	if (attr->task_fd_query.flags != 0)
4901 		return -EINVAL;
4902 
4903 	rcu_read_lock();
4904 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
4905 	rcu_read_unlock();
4906 	if (!task)
4907 		return -ENOENT;
4908 
4909 	err = 0;
4910 	file = fget_task(task, fd);
4911 	put_task_struct(task);
4912 	if (!file)
4913 		return -EBADF;
4914 
4915 	if (file->f_op == &bpf_link_fops) {
4916 		struct bpf_link *link = file->private_data;
4917 
4918 		if (link->ops == &bpf_raw_tp_link_lops) {
4919 			struct bpf_raw_tp_link *raw_tp =
4920 				container_of(link, struct bpf_raw_tp_link, link);
4921 			struct bpf_raw_event_map *btp = raw_tp->btp;
4922 
4923 			err = bpf_task_fd_query_copy(attr, uattr,
4924 						     raw_tp->link.prog->aux->id,
4925 						     BPF_FD_TYPE_RAW_TRACEPOINT,
4926 						     btp->tp->name, 0, 0);
4927 			goto put_file;
4928 		}
4929 		goto out_not_supp;
4930 	}
4931 
4932 	event = perf_get_event(file);
4933 	if (!IS_ERR(event)) {
4934 		u64 probe_offset, probe_addr;
4935 		u32 prog_id, fd_type;
4936 		const char *buf;
4937 
4938 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
4939 					      &buf, &probe_offset,
4940 					      &probe_addr, NULL);
4941 		if (!err)
4942 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
4943 						     fd_type, buf,
4944 						     probe_offset,
4945 						     probe_addr);
4946 		goto put_file;
4947 	}
4948 
4949 out_not_supp:
4950 	err = -ENOTSUPP;
4951 put_file:
4952 	fput(file);
4953 	return err;
4954 }
4955 
4956 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
4957 
4958 #define BPF_DO_BATCH(fn, ...)			\
4959 	do {					\
4960 		if (!fn) {			\
4961 			err = -ENOTSUPP;	\
4962 			goto err_put;		\
4963 		}				\
4964 		err = fn(__VA_ARGS__);		\
4965 	} while (0)
4966 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)4967 static int bpf_map_do_batch(const union bpf_attr *attr,
4968 			    union bpf_attr __user *uattr,
4969 			    int cmd)
4970 {
4971 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
4972 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
4973 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
4974 	struct bpf_map *map;
4975 	int err, ufd;
4976 	struct fd f;
4977 
4978 	if (CHECK_ATTR(BPF_MAP_BATCH))
4979 		return -EINVAL;
4980 
4981 	ufd = attr->batch.map_fd;
4982 	f = fdget(ufd);
4983 	map = __bpf_map_get(f);
4984 	if (IS_ERR(map))
4985 		return PTR_ERR(map);
4986 	if (has_write)
4987 		bpf_map_write_active_inc(map);
4988 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
4989 		err = -EPERM;
4990 		goto err_put;
4991 	}
4992 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
4993 		err = -EPERM;
4994 		goto err_put;
4995 	}
4996 
4997 	if (cmd == BPF_MAP_LOOKUP_BATCH)
4998 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
4999 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5000 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5001 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5002 		BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr);
5003 	else
5004 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5005 err_put:
5006 	if (has_write)
5007 		bpf_map_write_active_dec(map);
5008 	fdput(f);
5009 	return err;
5010 }
5011 
5012 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5013 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5014 {
5015 	struct bpf_prog *prog;
5016 	int ret;
5017 
5018 	if (CHECK_ATTR(BPF_LINK_CREATE))
5019 		return -EINVAL;
5020 
5021 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5022 		return bpf_struct_ops_link_create(attr);
5023 
5024 	prog = bpf_prog_get(attr->link_create.prog_fd);
5025 	if (IS_ERR(prog))
5026 		return PTR_ERR(prog);
5027 
5028 	ret = bpf_prog_attach_check_attach_type(prog,
5029 						attr->link_create.attach_type);
5030 	if (ret)
5031 		goto out;
5032 
5033 	switch (prog->type) {
5034 	case BPF_PROG_TYPE_CGROUP_SKB:
5035 	case BPF_PROG_TYPE_CGROUP_SOCK:
5036 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5037 	case BPF_PROG_TYPE_SOCK_OPS:
5038 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5039 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5040 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5041 		ret = cgroup_bpf_link_attach(attr, prog);
5042 		break;
5043 	case BPF_PROG_TYPE_EXT:
5044 		ret = bpf_tracing_prog_attach(prog,
5045 					      attr->link_create.target_fd,
5046 					      attr->link_create.target_btf_id,
5047 					      attr->link_create.tracing.cookie);
5048 		break;
5049 	case BPF_PROG_TYPE_LSM:
5050 	case BPF_PROG_TYPE_TRACING:
5051 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5052 			ret = -EINVAL;
5053 			goto out;
5054 		}
5055 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5056 			ret = bpf_raw_tp_link_attach(prog, NULL);
5057 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5058 			ret = bpf_iter_link_attach(attr, uattr, prog);
5059 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5060 			ret = cgroup_bpf_link_attach(attr, prog);
5061 		else
5062 			ret = bpf_tracing_prog_attach(prog,
5063 						      attr->link_create.target_fd,
5064 						      attr->link_create.target_btf_id,
5065 						      attr->link_create.tracing.cookie);
5066 		break;
5067 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5068 	case BPF_PROG_TYPE_SK_LOOKUP:
5069 		ret = netns_bpf_link_create(attr, prog);
5070 		break;
5071 #ifdef CONFIG_NET
5072 	case BPF_PROG_TYPE_XDP:
5073 		ret = bpf_xdp_link_attach(attr, prog);
5074 		break;
5075 	case BPF_PROG_TYPE_SCHED_CLS:
5076 		ret = tcx_link_attach(attr, prog);
5077 		break;
5078 	case BPF_PROG_TYPE_NETFILTER:
5079 		ret = bpf_nf_link_attach(attr, prog);
5080 		break;
5081 #endif
5082 	case BPF_PROG_TYPE_PERF_EVENT:
5083 	case BPF_PROG_TYPE_TRACEPOINT:
5084 		ret = bpf_perf_link_attach(attr, prog);
5085 		break;
5086 	case BPF_PROG_TYPE_KPROBE:
5087 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5088 			ret = bpf_perf_link_attach(attr, prog);
5089 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI)
5090 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5091 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI)
5092 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5093 		break;
5094 	default:
5095 		ret = -EINVAL;
5096 	}
5097 
5098 out:
5099 	if (ret < 0)
5100 		bpf_prog_put(prog);
5101 	return ret;
5102 }
5103 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5104 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5105 {
5106 	struct bpf_map *new_map, *old_map = NULL;
5107 	int ret;
5108 
5109 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5110 	if (IS_ERR(new_map))
5111 		return PTR_ERR(new_map);
5112 
5113 	if (attr->link_update.flags & BPF_F_REPLACE) {
5114 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5115 		if (IS_ERR(old_map)) {
5116 			ret = PTR_ERR(old_map);
5117 			goto out_put;
5118 		}
5119 	} else if (attr->link_update.old_map_fd) {
5120 		ret = -EINVAL;
5121 		goto out_put;
5122 	}
5123 
5124 	ret = link->ops->update_map(link, new_map, old_map);
5125 
5126 	if (old_map)
5127 		bpf_map_put(old_map);
5128 out_put:
5129 	bpf_map_put(new_map);
5130 	return ret;
5131 }
5132 
5133 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5134 
link_update(union bpf_attr * attr)5135 static int link_update(union bpf_attr *attr)
5136 {
5137 	struct bpf_prog *old_prog = NULL, *new_prog;
5138 	struct bpf_link *link;
5139 	u32 flags;
5140 	int ret;
5141 
5142 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5143 		return -EINVAL;
5144 
5145 	flags = attr->link_update.flags;
5146 	if (flags & ~BPF_F_REPLACE)
5147 		return -EINVAL;
5148 
5149 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5150 	if (IS_ERR(link))
5151 		return PTR_ERR(link);
5152 
5153 	if (link->ops->update_map) {
5154 		ret = link_update_map(link, attr);
5155 		goto out_put_link;
5156 	}
5157 
5158 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5159 	if (IS_ERR(new_prog)) {
5160 		ret = PTR_ERR(new_prog);
5161 		goto out_put_link;
5162 	}
5163 
5164 	if (flags & BPF_F_REPLACE) {
5165 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5166 		if (IS_ERR(old_prog)) {
5167 			ret = PTR_ERR(old_prog);
5168 			old_prog = NULL;
5169 			goto out_put_progs;
5170 		}
5171 	} else if (attr->link_update.old_prog_fd) {
5172 		ret = -EINVAL;
5173 		goto out_put_progs;
5174 	}
5175 
5176 	if (link->ops->update_prog)
5177 		ret = link->ops->update_prog(link, new_prog, old_prog);
5178 	else
5179 		ret = -EINVAL;
5180 
5181 out_put_progs:
5182 	if (old_prog)
5183 		bpf_prog_put(old_prog);
5184 	if (ret)
5185 		bpf_prog_put(new_prog);
5186 out_put_link:
5187 	bpf_link_put_direct(link);
5188 	return ret;
5189 }
5190 
5191 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5192 
link_detach(union bpf_attr * attr)5193 static int link_detach(union bpf_attr *attr)
5194 {
5195 	struct bpf_link *link;
5196 	int ret;
5197 
5198 	if (CHECK_ATTR(BPF_LINK_DETACH))
5199 		return -EINVAL;
5200 
5201 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5202 	if (IS_ERR(link))
5203 		return PTR_ERR(link);
5204 
5205 	if (link->ops->detach)
5206 		ret = link->ops->detach(link);
5207 	else
5208 		ret = -EOPNOTSUPP;
5209 
5210 	bpf_link_put_direct(link);
5211 	return ret;
5212 }
5213 
bpf_link_inc_not_zero(struct bpf_link * link)5214 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5215 {
5216 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5217 }
5218 
bpf_link_by_id(u32 id)5219 struct bpf_link *bpf_link_by_id(u32 id)
5220 {
5221 	struct bpf_link *link;
5222 
5223 	if (!id)
5224 		return ERR_PTR(-ENOENT);
5225 
5226 	spin_lock_bh(&link_idr_lock);
5227 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5228 	link = idr_find(&link_idr, id);
5229 	if (link) {
5230 		if (link->id)
5231 			link = bpf_link_inc_not_zero(link);
5232 		else
5233 			link = ERR_PTR(-EAGAIN);
5234 	} else {
5235 		link = ERR_PTR(-ENOENT);
5236 	}
5237 	spin_unlock_bh(&link_idr_lock);
5238 	return link;
5239 }
5240 
bpf_link_get_curr_or_next(u32 * id)5241 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5242 {
5243 	struct bpf_link *link;
5244 
5245 	spin_lock_bh(&link_idr_lock);
5246 again:
5247 	link = idr_get_next(&link_idr, id);
5248 	if (link) {
5249 		link = bpf_link_inc_not_zero(link);
5250 		if (IS_ERR(link)) {
5251 			(*id)++;
5252 			goto again;
5253 		}
5254 	}
5255 	spin_unlock_bh(&link_idr_lock);
5256 
5257 	return link;
5258 }
5259 
5260 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5261 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5262 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5263 {
5264 	struct bpf_link *link;
5265 	u32 id = attr->link_id;
5266 	int fd;
5267 
5268 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5269 		return -EINVAL;
5270 
5271 	if (!capable(CAP_SYS_ADMIN))
5272 		return -EPERM;
5273 
5274 	link = bpf_link_by_id(id);
5275 	if (IS_ERR(link))
5276 		return PTR_ERR(link);
5277 
5278 	fd = bpf_link_new_fd(link);
5279 	if (fd < 0)
5280 		bpf_link_put_direct(link);
5281 
5282 	return fd;
5283 }
5284 
5285 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5286 
bpf_stats_release(struct inode * inode,struct file * file)5287 static int bpf_stats_release(struct inode *inode, struct file *file)
5288 {
5289 	mutex_lock(&bpf_stats_enabled_mutex);
5290 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5291 	mutex_unlock(&bpf_stats_enabled_mutex);
5292 	return 0;
5293 }
5294 
5295 static const struct file_operations bpf_stats_fops = {
5296 	.release = bpf_stats_release,
5297 };
5298 
bpf_enable_runtime_stats(void)5299 static int bpf_enable_runtime_stats(void)
5300 {
5301 	int fd;
5302 
5303 	mutex_lock(&bpf_stats_enabled_mutex);
5304 
5305 	/* Set a very high limit to avoid overflow */
5306 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5307 		mutex_unlock(&bpf_stats_enabled_mutex);
5308 		return -EBUSY;
5309 	}
5310 
5311 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5312 	if (fd >= 0)
5313 		static_key_slow_inc(&bpf_stats_enabled_key.key);
5314 
5315 	mutex_unlock(&bpf_stats_enabled_mutex);
5316 	return fd;
5317 }
5318 
5319 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5320 
bpf_enable_stats(union bpf_attr * attr)5321 static int bpf_enable_stats(union bpf_attr *attr)
5322 {
5323 
5324 	if (CHECK_ATTR(BPF_ENABLE_STATS))
5325 		return -EINVAL;
5326 
5327 	if (!capable(CAP_SYS_ADMIN))
5328 		return -EPERM;
5329 
5330 	switch (attr->enable_stats.type) {
5331 	case BPF_STATS_RUN_TIME:
5332 		return bpf_enable_runtime_stats();
5333 	default:
5334 		break;
5335 	}
5336 	return -EINVAL;
5337 }
5338 
5339 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
5340 
bpf_iter_create(union bpf_attr * attr)5341 static int bpf_iter_create(union bpf_attr *attr)
5342 {
5343 	struct bpf_link *link;
5344 	int err;
5345 
5346 	if (CHECK_ATTR(BPF_ITER_CREATE))
5347 		return -EINVAL;
5348 
5349 	if (attr->iter_create.flags)
5350 		return -EINVAL;
5351 
5352 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
5353 	if (IS_ERR(link))
5354 		return PTR_ERR(link);
5355 
5356 	err = bpf_iter_new_fd(link);
5357 	bpf_link_put_direct(link);
5358 
5359 	return err;
5360 }
5361 
5362 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
5363 
bpf_prog_bind_map(union bpf_attr * attr)5364 static int bpf_prog_bind_map(union bpf_attr *attr)
5365 {
5366 	struct bpf_prog *prog;
5367 	struct bpf_map *map;
5368 	struct bpf_map **used_maps_old, **used_maps_new;
5369 	int i, ret = 0;
5370 
5371 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
5372 		return -EINVAL;
5373 
5374 	if (attr->prog_bind_map.flags)
5375 		return -EINVAL;
5376 
5377 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
5378 	if (IS_ERR(prog))
5379 		return PTR_ERR(prog);
5380 
5381 	map = bpf_map_get(attr->prog_bind_map.map_fd);
5382 	if (IS_ERR(map)) {
5383 		ret = PTR_ERR(map);
5384 		goto out_prog_put;
5385 	}
5386 
5387 	mutex_lock(&prog->aux->used_maps_mutex);
5388 
5389 	used_maps_old = prog->aux->used_maps;
5390 
5391 	for (i = 0; i < prog->aux->used_map_cnt; i++)
5392 		if (used_maps_old[i] == map) {
5393 			bpf_map_put(map);
5394 			goto out_unlock;
5395 		}
5396 
5397 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
5398 				      sizeof(used_maps_new[0]),
5399 				      GFP_KERNEL);
5400 	if (!used_maps_new) {
5401 		ret = -ENOMEM;
5402 		goto out_unlock;
5403 	}
5404 
5405 	/* The bpf program will not access the bpf map, but for the sake of
5406 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
5407 	 */
5408 	if (prog->aux->sleepable)
5409 		atomic64_inc(&map->sleepable_refcnt);
5410 	memcpy(used_maps_new, used_maps_old,
5411 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
5412 	used_maps_new[prog->aux->used_map_cnt] = map;
5413 
5414 	prog->aux->used_map_cnt++;
5415 	prog->aux->used_maps = used_maps_new;
5416 
5417 	kfree(used_maps_old);
5418 
5419 out_unlock:
5420 	mutex_unlock(&prog->aux->used_maps_mutex);
5421 
5422 	if (ret)
5423 		bpf_map_put(map);
5424 out_prog_put:
5425 	bpf_prog_put(prog);
5426 	return ret;
5427 }
5428 
__sys_bpf(int cmd,bpfptr_t uattr,unsigned int size)5429 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
5430 {
5431 	union bpf_attr attr;
5432 	int err;
5433 
5434 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
5435 	if (err)
5436 		return err;
5437 	size = min_t(u32, size, sizeof(attr));
5438 
5439 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
5440 	memset(&attr, 0, sizeof(attr));
5441 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
5442 		return -EFAULT;
5443 
5444 	err = security_bpf(cmd, &attr, size);
5445 	if (err < 0)
5446 		return err;
5447 
5448 	switch (cmd) {
5449 	case BPF_MAP_CREATE:
5450 		err = map_create(&attr);
5451 		break;
5452 	case BPF_MAP_LOOKUP_ELEM:
5453 		err = map_lookup_elem(&attr);
5454 		break;
5455 	case BPF_MAP_UPDATE_ELEM:
5456 		err = map_update_elem(&attr, uattr);
5457 		break;
5458 	case BPF_MAP_DELETE_ELEM:
5459 		err = map_delete_elem(&attr, uattr);
5460 		break;
5461 	case BPF_MAP_GET_NEXT_KEY:
5462 		err = map_get_next_key(&attr);
5463 		break;
5464 	case BPF_MAP_FREEZE:
5465 		err = map_freeze(&attr);
5466 		break;
5467 	case BPF_PROG_LOAD:
5468 		err = bpf_prog_load(&attr, uattr, size);
5469 		break;
5470 	case BPF_OBJ_PIN:
5471 		err = bpf_obj_pin(&attr);
5472 		break;
5473 	case BPF_OBJ_GET:
5474 		err = bpf_obj_get(&attr);
5475 		break;
5476 	case BPF_PROG_ATTACH:
5477 		err = bpf_prog_attach(&attr);
5478 		break;
5479 	case BPF_PROG_DETACH:
5480 		err = bpf_prog_detach(&attr);
5481 		break;
5482 	case BPF_PROG_QUERY:
5483 		err = bpf_prog_query(&attr, uattr.user);
5484 		break;
5485 	case BPF_PROG_TEST_RUN:
5486 		err = bpf_prog_test_run(&attr, uattr.user);
5487 		break;
5488 	case BPF_PROG_GET_NEXT_ID:
5489 		err = bpf_obj_get_next_id(&attr, uattr.user,
5490 					  &prog_idr, &prog_idr_lock);
5491 		break;
5492 	case BPF_MAP_GET_NEXT_ID:
5493 		err = bpf_obj_get_next_id(&attr, uattr.user,
5494 					  &map_idr, &map_idr_lock);
5495 		break;
5496 	case BPF_BTF_GET_NEXT_ID:
5497 		err = bpf_obj_get_next_id(&attr, uattr.user,
5498 					  &btf_idr, &btf_idr_lock);
5499 		break;
5500 	case BPF_PROG_GET_FD_BY_ID:
5501 		err = bpf_prog_get_fd_by_id(&attr);
5502 		break;
5503 	case BPF_MAP_GET_FD_BY_ID:
5504 		err = bpf_map_get_fd_by_id(&attr);
5505 		break;
5506 	case BPF_OBJ_GET_INFO_BY_FD:
5507 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
5508 		break;
5509 	case BPF_RAW_TRACEPOINT_OPEN:
5510 		err = bpf_raw_tracepoint_open(&attr);
5511 		break;
5512 	case BPF_BTF_LOAD:
5513 		err = bpf_btf_load(&attr, uattr, size);
5514 		break;
5515 	case BPF_BTF_GET_FD_BY_ID:
5516 		err = bpf_btf_get_fd_by_id(&attr);
5517 		break;
5518 	case BPF_TASK_FD_QUERY:
5519 		err = bpf_task_fd_query(&attr, uattr.user);
5520 		break;
5521 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
5522 		err = map_lookup_and_delete_elem(&attr);
5523 		break;
5524 	case BPF_MAP_LOOKUP_BATCH:
5525 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
5526 		break;
5527 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
5528 		err = bpf_map_do_batch(&attr, uattr.user,
5529 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
5530 		break;
5531 	case BPF_MAP_UPDATE_BATCH:
5532 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
5533 		break;
5534 	case BPF_MAP_DELETE_BATCH:
5535 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
5536 		break;
5537 	case BPF_LINK_CREATE:
5538 		err = link_create(&attr, uattr);
5539 		break;
5540 	case BPF_LINK_UPDATE:
5541 		err = link_update(&attr);
5542 		break;
5543 	case BPF_LINK_GET_FD_BY_ID:
5544 		err = bpf_link_get_fd_by_id(&attr);
5545 		break;
5546 	case BPF_LINK_GET_NEXT_ID:
5547 		err = bpf_obj_get_next_id(&attr, uattr.user,
5548 					  &link_idr, &link_idr_lock);
5549 		break;
5550 	case BPF_ENABLE_STATS:
5551 		err = bpf_enable_stats(&attr);
5552 		break;
5553 	case BPF_ITER_CREATE:
5554 		err = bpf_iter_create(&attr);
5555 		break;
5556 	case BPF_LINK_DETACH:
5557 		err = link_detach(&attr);
5558 		break;
5559 	case BPF_PROG_BIND_MAP:
5560 		err = bpf_prog_bind_map(&attr);
5561 		break;
5562 	default:
5563 		err = -EINVAL;
5564 		break;
5565 	}
5566 
5567 	return err;
5568 }
5569 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5570 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5571 {
5572 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5573 }
5574 
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)5575 static bool syscall_prog_is_valid_access(int off, int size,
5576 					 enum bpf_access_type type,
5577 					 const struct bpf_prog *prog,
5578 					 struct bpf_insn_access_aux *info)
5579 {
5580 	if (off < 0 || off >= U16_MAX)
5581 		return false;
5582 	if (off % size != 0)
5583 		return false;
5584 	return true;
5585 }
5586 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5587 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5588 {
5589 	switch (cmd) {
5590 	case BPF_MAP_CREATE:
5591 	case BPF_MAP_DELETE_ELEM:
5592 	case BPF_MAP_UPDATE_ELEM:
5593 	case BPF_MAP_FREEZE:
5594 	case BPF_MAP_GET_FD_BY_ID:
5595 	case BPF_PROG_LOAD:
5596 	case BPF_BTF_LOAD:
5597 	case BPF_LINK_CREATE:
5598 	case BPF_RAW_TRACEPOINT_OPEN:
5599 		break;
5600 	default:
5601 		return -EINVAL;
5602 	}
5603 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5604 }
5605 
5606 
5607 /* To shut up -Wmissing-prototypes.
5608  * This function is used by the kernel light skeleton
5609  * to load bpf programs when modules are loaded or during kernel boot.
5610  * See tools/lib/bpf/skel_internal.h
5611  */
5612 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
5613 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5614 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5615 {
5616 	struct bpf_prog * __maybe_unused prog;
5617 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5618 
5619 	switch (cmd) {
5620 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5621 	case BPF_PROG_TEST_RUN:
5622 		if (attr->test.data_in || attr->test.data_out ||
5623 		    attr->test.ctx_out || attr->test.duration ||
5624 		    attr->test.repeat || attr->test.flags)
5625 			return -EINVAL;
5626 
5627 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5628 		if (IS_ERR(prog))
5629 			return PTR_ERR(prog);
5630 
5631 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
5632 		    attr->test.ctx_size_in > U16_MAX) {
5633 			bpf_prog_put(prog);
5634 			return -EINVAL;
5635 		}
5636 
5637 		run_ctx.bpf_cookie = 0;
5638 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
5639 			/* recursion detected */
5640 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
5641 			bpf_prog_put(prog);
5642 			return -EBUSY;
5643 		}
5644 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
5645 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
5646 						&run_ctx);
5647 		bpf_prog_put(prog);
5648 		return 0;
5649 #endif
5650 	default:
5651 		return ____bpf_sys_bpf(cmd, attr, size);
5652 	}
5653 }
5654 EXPORT_SYMBOL(kern_sys_bpf);
5655 
5656 static const struct bpf_func_proto bpf_sys_bpf_proto = {
5657 	.func		= bpf_sys_bpf,
5658 	.gpl_only	= false,
5659 	.ret_type	= RET_INTEGER,
5660 	.arg1_type	= ARG_ANYTHING,
5661 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
5662 	.arg3_type	= ARG_CONST_SIZE,
5663 };
5664 
5665 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5666 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5667 {
5668 	return bpf_base_func_proto(func_id);
5669 }
5670 
BPF_CALL_1(bpf_sys_close,u32,fd)5671 BPF_CALL_1(bpf_sys_close, u32, fd)
5672 {
5673 	/* When bpf program calls this helper there should not be
5674 	 * an fdget() without matching completed fdput().
5675 	 * This helper is allowed in the following callchain only:
5676 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
5677 	 */
5678 	return close_fd(fd);
5679 }
5680 
5681 static const struct bpf_func_proto bpf_sys_close_proto = {
5682 	.func		= bpf_sys_close,
5683 	.gpl_only	= false,
5684 	.ret_type	= RET_INTEGER,
5685 	.arg1_type	= ARG_ANYTHING,
5686 };
5687 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)5688 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
5689 {
5690 	*res = 0;
5691 	if (flags)
5692 		return -EINVAL;
5693 
5694 	if (name_sz <= 1 || name[name_sz - 1])
5695 		return -EINVAL;
5696 
5697 	if (!bpf_dump_raw_ok(current_cred()))
5698 		return -EPERM;
5699 
5700 	*res = kallsyms_lookup_name(name);
5701 	return *res ? 0 : -ENOENT;
5702 }
5703 
5704 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
5705 	.func		= bpf_kallsyms_lookup_name,
5706 	.gpl_only	= false,
5707 	.ret_type	= RET_INTEGER,
5708 	.arg1_type	= ARG_PTR_TO_MEM,
5709 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
5710 	.arg3_type	= ARG_ANYTHING,
5711 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
5712 	.arg4_size	= sizeof(u64),
5713 };
5714 
5715 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5716 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5717 {
5718 	switch (func_id) {
5719 	case BPF_FUNC_sys_bpf:
5720 		return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto;
5721 	case BPF_FUNC_btf_find_by_name_kind:
5722 		return &bpf_btf_find_by_name_kind_proto;
5723 	case BPF_FUNC_sys_close:
5724 		return &bpf_sys_close_proto;
5725 	case BPF_FUNC_kallsyms_lookup_name:
5726 		return &bpf_kallsyms_lookup_name_proto;
5727 	default:
5728 		return tracing_prog_func_proto(func_id, prog);
5729 	}
5730 }
5731 
5732 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
5733 	.get_func_proto  = syscall_prog_func_proto,
5734 	.is_valid_access = syscall_prog_is_valid_access,
5735 };
5736 
5737 const struct bpf_prog_ops bpf_syscall_prog_ops = {
5738 	.test_run = bpf_prog_test_run_syscall,
5739 };
5740 
5741 #ifdef CONFIG_SYSCTL
bpf_stats_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5742 static int bpf_stats_handler(struct ctl_table *table, int write,
5743 			     void *buffer, size_t *lenp, loff_t *ppos)
5744 {
5745 	struct static_key *key = (struct static_key *)table->data;
5746 	static int saved_val;
5747 	int val, ret;
5748 	struct ctl_table tmp = {
5749 		.data   = &val,
5750 		.maxlen = sizeof(val),
5751 		.mode   = table->mode,
5752 		.extra1 = SYSCTL_ZERO,
5753 		.extra2 = SYSCTL_ONE,
5754 	};
5755 
5756 	if (write && !capable(CAP_SYS_ADMIN))
5757 		return -EPERM;
5758 
5759 	mutex_lock(&bpf_stats_enabled_mutex);
5760 	val = saved_val;
5761 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
5762 	if (write && !ret && val != saved_val) {
5763 		if (val)
5764 			static_key_slow_inc(key);
5765 		else
5766 			static_key_slow_dec(key);
5767 		saved_val = val;
5768 	}
5769 	mutex_unlock(&bpf_stats_enabled_mutex);
5770 	return ret;
5771 }
5772 
unpriv_ebpf_notify(int new_state)5773 void __weak unpriv_ebpf_notify(int new_state)
5774 {
5775 }
5776 
bpf_unpriv_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5777 static int bpf_unpriv_handler(struct ctl_table *table, int write,
5778 			      void *buffer, size_t *lenp, loff_t *ppos)
5779 {
5780 	int ret, unpriv_enable = *(int *)table->data;
5781 	bool locked_state = unpriv_enable == 1;
5782 	struct ctl_table tmp = *table;
5783 
5784 	if (write && !capable(CAP_SYS_ADMIN))
5785 		return -EPERM;
5786 
5787 	tmp.data = &unpriv_enable;
5788 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
5789 	if (write && !ret) {
5790 		if (locked_state && unpriv_enable != 1)
5791 			return -EPERM;
5792 		*(int *)table->data = unpriv_enable;
5793 	}
5794 
5795 	if (write)
5796 		unpriv_ebpf_notify(unpriv_enable);
5797 
5798 	return ret;
5799 }
5800 
5801 static struct ctl_table bpf_syscall_table[] = {
5802 	{
5803 		.procname	= "unprivileged_bpf_disabled",
5804 		.data		= &sysctl_unprivileged_bpf_disabled,
5805 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
5806 		.mode		= 0644,
5807 		.proc_handler	= bpf_unpriv_handler,
5808 		.extra1		= SYSCTL_ZERO,
5809 		.extra2		= SYSCTL_TWO,
5810 	},
5811 	{
5812 		.procname	= "bpf_stats_enabled",
5813 		.data		= &bpf_stats_enabled_key.key,
5814 		.mode		= 0644,
5815 		.proc_handler	= bpf_stats_handler,
5816 	},
5817 	{ }
5818 };
5819 
bpf_syscall_sysctl_init(void)5820 static int __init bpf_syscall_sysctl_init(void)
5821 {
5822 	register_sysctl_init("kernel", bpf_syscall_table);
5823 	return 0;
5824 }
5825 late_initcall(bpf_syscall_sysctl_init);
5826 #endif /* CONFIG_SYSCTL */
5827