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