xref: /linux/kernel/bpf/syscall.c (revision 32e940f2bd3b16551f23ea44be47f6f5d1746d64) !
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3  */
4 #include <crypto/sha2.h>
5 #include <linux/bpf.h>
6 #include <linux/bpf-cgroup.h>
7 #include <linux/bpf_trace.h>
8 #include <linux/bpf_lirc.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bsearch.h>
11 #include <linux/btf.h>
12 #include <linux/hex.h>
13 #include <linux/syscalls.h>
14 #include <linux/slab.h>
15 #include <linux/sched/signal.h>
16 #include <linux/vmalloc.h>
17 #include <linux/mmzone.h>
18 #include <linux/anon_inodes.h>
19 #include <linux/fdtable.h>
20 #include <linux/file.h>
21 #include <linux/fs.h>
22 #include <linux/license.h>
23 #include <linux/filter.h>
24 #include <linux/kernel.h>
25 #include <linux/idr.h>
26 #include <linux/cred.h>
27 #include <linux/timekeeping.h>
28 #include <linux/ctype.h>
29 #include <linux/nospec.h>
30 #include <linux/audit.h>
31 #include <uapi/linux/btf.h>
32 #include <linux/pgtable.h>
33 #include <linux/bpf_lsm.h>
34 #include <linux/poll.h>
35 #include <linux/sort.h>
36 #include <linux/bpf-netns.h>
37 #include <linux/rcupdate_trace.h>
38 #include <linux/memcontrol.h>
39 #include <linux/trace_events.h>
40 #include <linux/tracepoint.h>
41 #include <linux/overflow.h>
42 #include <linux/cookie.h>
43 #include <linux/verification.h>
44 
45 #include <net/netfilter/nf_bpf_link.h>
46 #include <net/netkit.h>
47 #include <net/tcx.h>
48 
49 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
50 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
51 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
52 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
53 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
54 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
55 			IS_FD_HASH(map))
56 
57 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
58 
59 DEFINE_PER_CPU(int, bpf_prog_active);
60 DEFINE_COOKIE(bpf_map_cookie);
61 static DEFINE_IDR(prog_idr);
62 static DEFINE_SPINLOCK(prog_idr_lock);
63 static DEFINE_IDR(map_idr);
64 static DEFINE_SPINLOCK(map_idr_lock);
65 static DEFINE_IDR(link_idr);
66 static DEFINE_SPINLOCK(link_idr_lock);
67 
68 int sysctl_unprivileged_bpf_disabled __read_mostly =
69 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
70 
71 static const struct bpf_map_ops * const bpf_map_types[] = {
72 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
73 #define BPF_MAP_TYPE(_id, _ops) \
74 	[_id] = &_ops,
75 #define BPF_LINK_TYPE(_id, _name)
76 #include <linux/bpf_types.h>
77 #undef BPF_PROG_TYPE
78 #undef BPF_MAP_TYPE
79 #undef BPF_LINK_TYPE
80 };
81 
82 /*
83  * If we're handed a bigger struct than we know of, ensure all the unknown bits
84  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
85  * we don't know about yet.
86  *
87  * There is a ToCToU between this function call and the following
88  * copy_from_user() call. However, this is not a concern since this function is
89  * meant to be a future-proofing of bits.
90  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)91 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
92 			     size_t expected_size,
93 			     size_t actual_size)
94 {
95 	int res;
96 
97 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
98 		return -E2BIG;
99 
100 	if (actual_size <= expected_size)
101 		return 0;
102 
103 	if (uaddr.is_kernel)
104 		res = memchr_inv(uaddr.kernel + expected_size, 0,
105 				 actual_size - expected_size) == NULL;
106 	else
107 		res = check_zeroed_user(uaddr.user + expected_size,
108 					actual_size - expected_size);
109 	if (res < 0)
110 		return res;
111 	return res ? 0 : -E2BIG;
112 }
113 
114 const struct bpf_map_ops bpf_map_offload_ops = {
115 	.map_meta_equal = bpf_map_meta_equal,
116 	.map_alloc = bpf_map_offload_map_alloc,
117 	.map_free = bpf_map_offload_map_free,
118 	.map_check_btf = map_check_no_btf,
119 	.map_mem_usage = bpf_map_offload_map_mem_usage,
120 };
121 
bpf_map_write_active_inc(struct bpf_map * map)122 static void bpf_map_write_active_inc(struct bpf_map *map)
123 {
124 	atomic64_inc(&map->writecnt);
125 }
126 
bpf_map_write_active_dec(struct bpf_map * map)127 static void bpf_map_write_active_dec(struct bpf_map *map)
128 {
129 	atomic64_dec(&map->writecnt);
130 }
131 
bpf_map_write_active(const struct bpf_map * map)132 bool bpf_map_write_active(const struct bpf_map *map)
133 {
134 	return atomic64_read(&map->writecnt) != 0;
135 }
136 
bpf_map_value_size(const struct bpf_map * map,u64 flags)137 static u32 bpf_map_value_size(const struct bpf_map *map, u64 flags)
138 {
139 	if (flags & (BPF_F_CPU | BPF_F_ALL_CPUS))
140 		return map->value_size;
141 	else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
142 		 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
143 		 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
144 		 map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
145 		return round_up(map->value_size, 8) * num_possible_cpus();
146 	else if (IS_FD_MAP(map))
147 		return sizeof(u32);
148 	else
149 		return  map->value_size;
150 }
151 
maybe_wait_bpf_programs(struct bpf_map * map)152 static void maybe_wait_bpf_programs(struct bpf_map *map)
153 {
154 	/* Wait for any running non-sleepable BPF programs to complete so that
155 	 * userspace, when we return to it, knows that all non-sleepable
156 	 * programs that could be running use the new map value. For sleepable
157 	 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
158 	 * for the completions of these programs, but considering the waiting
159 	 * time can be very long and userspace may think it will hang forever,
160 	 * so don't handle sleepable BPF programs now.
161 	 */
162 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
163 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
164 		synchronize_rcu_expedited();
165 }
166 
unpin_uptr_kaddr(void * kaddr)167 static void unpin_uptr_kaddr(void *kaddr)
168 {
169 	if (kaddr)
170 		unpin_user_page(virt_to_page(kaddr));
171 }
172 
__bpf_obj_unpin_uptrs(struct btf_record * rec,u32 cnt,void * obj)173 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj)
174 {
175 	const struct btf_field *field;
176 	void **uptr_addr;
177 	int i;
178 
179 	for (i = 0, field = rec->fields; i < cnt; i++, field++) {
180 		if (field->type != BPF_UPTR)
181 			continue;
182 
183 		uptr_addr = obj + field->offset;
184 		unpin_uptr_kaddr(*uptr_addr);
185 	}
186 }
187 
bpf_obj_unpin_uptrs(struct btf_record * rec,void * obj)188 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj)
189 {
190 	if (!btf_record_has_field(rec, BPF_UPTR))
191 		return;
192 
193 	__bpf_obj_unpin_uptrs(rec, rec->cnt, obj);
194 }
195 
bpf_obj_pin_uptrs(struct btf_record * rec,void * obj)196 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj)
197 {
198 	const struct btf_field *field;
199 	const struct btf_type *t;
200 	unsigned long start, end;
201 	struct page *page;
202 	void **uptr_addr;
203 	int i, err;
204 
205 	if (!btf_record_has_field(rec, BPF_UPTR))
206 		return 0;
207 
208 	for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) {
209 		if (field->type != BPF_UPTR)
210 			continue;
211 
212 		uptr_addr = obj + field->offset;
213 		start = *(unsigned long *)uptr_addr;
214 		if (!start)
215 			continue;
216 
217 		t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id);
218 		/* t->size was checked for zero before */
219 		if (check_add_overflow(start, t->size - 1, &end)) {
220 			err = -EFAULT;
221 			goto unpin_all;
222 		}
223 
224 		/* The uptr's struct cannot span across two pages */
225 		if ((start & PAGE_MASK) != (end & PAGE_MASK)) {
226 			err = -EOPNOTSUPP;
227 			goto unpin_all;
228 		}
229 
230 		err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page);
231 		if (err != 1)
232 			goto unpin_all;
233 
234 		if (PageHighMem(page)) {
235 			err = -EOPNOTSUPP;
236 			unpin_user_page(page);
237 			goto unpin_all;
238 		}
239 
240 		*uptr_addr = page_address(page) + offset_in_page(start);
241 	}
242 
243 	return 0;
244 
245 unpin_all:
246 	__bpf_obj_unpin_uptrs(rec, i, obj);
247 	return err;
248 }
249 
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)250 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
251 				void *key, void *value, __u64 flags)
252 {
253 	int err;
254 
255 	/* Need to create a kthread, thus must support schedule */
256 	if (bpf_map_is_offloaded(map)) {
257 		return bpf_map_offload_update_elem(map, key, value, flags);
258 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
259 		   map->map_type == BPF_MAP_TYPE_ARENA ||
260 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
261 		return map->ops->map_update_elem(map, key, value, flags);
262 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
263 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
264 		return sock_map_update_elem_sys(map, key, value, flags);
265 	} else if (IS_FD_PROG_ARRAY(map)) {
266 		return bpf_fd_array_map_update_elem(map, map_file, key, value,
267 						    flags);
268 	}
269 
270 	bpf_disable_instrumentation();
271 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
272 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
273 		err = bpf_percpu_hash_update(map, key, value, flags);
274 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
275 		err = bpf_percpu_array_update(map, key, value, flags);
276 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
277 		err = bpf_percpu_cgroup_storage_update(map, key, value,
278 						       flags);
279 	} else if (IS_FD_ARRAY(map)) {
280 		err = bpf_fd_array_map_update_elem(map, map_file, key, value,
281 						   flags);
282 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
283 		err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
284 						  flags);
285 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
286 		/* rcu_read_lock() is not needed */
287 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
288 							 flags);
289 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
290 		   map->map_type == BPF_MAP_TYPE_STACK ||
291 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
292 		err = map->ops->map_push_elem(map, value, flags);
293 	} else {
294 		err = bpf_obj_pin_uptrs(map->record, value);
295 		if (!err) {
296 			rcu_read_lock();
297 			err = map->ops->map_update_elem(map, key, value, flags);
298 			rcu_read_unlock();
299 			if (err)
300 				bpf_obj_unpin_uptrs(map->record, value);
301 		}
302 	}
303 	bpf_enable_instrumentation();
304 
305 	return err;
306 }
307 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)308 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
309 			      __u64 flags)
310 {
311 	void *ptr;
312 	int err;
313 
314 	if (bpf_map_is_offloaded(map))
315 		return bpf_map_offload_lookup_elem(map, key, value);
316 
317 	bpf_disable_instrumentation();
318 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
319 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
320 		err = bpf_percpu_hash_copy(map, key, value, flags);
321 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
322 		err = bpf_percpu_array_copy(map, key, value, flags);
323 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
324 		err = bpf_percpu_cgroup_storage_copy(map, key, value, flags);
325 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
326 		err = bpf_stackmap_extract(map, key, value, false);
327 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
328 		err = bpf_fd_array_map_lookup_elem(map, key, value);
329 	} else if (IS_FD_HASH(map)) {
330 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
331 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
332 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
333 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
334 		   map->map_type == BPF_MAP_TYPE_STACK ||
335 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
336 		err = map->ops->map_peek_elem(map, value);
337 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
338 		/* struct_ops map requires directly updating "value" */
339 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
340 	} else {
341 		rcu_read_lock();
342 		if (map->ops->map_lookup_elem_sys_only)
343 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
344 		else
345 			ptr = map->ops->map_lookup_elem(map, key);
346 		if (IS_ERR(ptr)) {
347 			err = PTR_ERR(ptr);
348 		} else if (!ptr) {
349 			err = -ENOENT;
350 		} else {
351 			err = 0;
352 			if (flags & BPF_F_LOCK)
353 				/* lock 'ptr' and copy everything but lock */
354 				copy_map_value_locked(map, value, ptr, true);
355 			else
356 				copy_map_value(map, value, ptr);
357 			/* mask lock and timer, since value wasn't zero inited */
358 			check_and_init_map_value(map, value);
359 		}
360 		rcu_read_unlock();
361 	}
362 
363 	bpf_enable_instrumentation();
364 
365 	return err;
366 }
367 
368 /* Please, do not use this function outside from the map creation path
369  * (e.g. in map update path) without taking care of setting the active
370  * memory cgroup (see at bpf_map_kmalloc_node() for example).
371  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)372 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
373 {
374 	/* We really just want to fail instead of triggering OOM killer
375 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
376 	 * which is used for lower order allocation requests.
377 	 *
378 	 * It has been observed that higher order allocation requests done by
379 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
380 	 * to reclaim memory from the page cache, thus we set
381 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
382 	 */
383 
384 	gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
385 	unsigned int flags = 0;
386 	unsigned long align = 1;
387 	void *area;
388 
389 	if (size >= SIZE_MAX)
390 		return NULL;
391 
392 	/* kmalloc()'ed memory can't be mmap()'ed */
393 	if (mmapable) {
394 		BUG_ON(!PAGE_ALIGNED(size));
395 		align = SHMLBA;
396 		flags = VM_USERMAP;
397 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
398 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
399 				    numa_node);
400 		if (area != NULL)
401 			return area;
402 	}
403 
404 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
405 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
406 			flags, numa_node, __builtin_return_address(0));
407 }
408 
bpf_map_area_alloc(u64 size,int numa_node)409 void *bpf_map_area_alloc(u64 size, int numa_node)
410 {
411 	return __bpf_map_area_alloc(size, numa_node, false);
412 }
413 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)414 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
415 {
416 	return __bpf_map_area_alloc(size, numa_node, true);
417 }
418 
bpf_map_area_free(void * area)419 void bpf_map_area_free(void *area)
420 {
421 	kvfree(area);
422 }
423 
bpf_map_flags_retain_permanent(u32 flags)424 static u32 bpf_map_flags_retain_permanent(u32 flags)
425 {
426 	/* Some map creation flags are not tied to the map object but
427 	 * rather to the map fd instead, so they have no meaning upon
428 	 * map object inspection since multiple file descriptors with
429 	 * different (access) properties can exist here. Thus, given
430 	 * this has zero meaning for the map itself, lets clear these
431 	 * from here.
432 	 */
433 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
434 }
435 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)436 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
437 {
438 	map->map_type = attr->map_type;
439 	map->key_size = attr->key_size;
440 	map->value_size = attr->value_size;
441 	map->max_entries = attr->max_entries;
442 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
443 	map->numa_node = bpf_map_attr_numa_node(attr);
444 	map->map_extra = attr->map_extra;
445 }
446 
bpf_map_alloc_id(struct bpf_map * map)447 static int bpf_map_alloc_id(struct bpf_map *map)
448 {
449 	int id;
450 
451 	idr_preload(GFP_KERNEL);
452 	spin_lock_bh(&map_idr_lock);
453 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
454 	if (id > 0)
455 		map->id = id;
456 	spin_unlock_bh(&map_idr_lock);
457 	idr_preload_end();
458 
459 	if (WARN_ON_ONCE(!id))
460 		return -ENOSPC;
461 
462 	return id > 0 ? 0 : id;
463 }
464 
bpf_map_free_id(struct bpf_map * map)465 void bpf_map_free_id(struct bpf_map *map)
466 {
467 	unsigned long flags;
468 
469 	/* Offloaded maps are removed from the IDR store when their device
470 	 * disappears - even if someone holds an fd to them they are unusable,
471 	 * the memory is gone, all ops will fail; they are simply waiting for
472 	 * refcnt to drop to be freed.
473 	 */
474 	if (!map->id)
475 		return;
476 
477 	spin_lock_irqsave(&map_idr_lock, flags);
478 
479 	idr_remove(&map_idr, map->id);
480 	map->id = 0;
481 
482 	spin_unlock_irqrestore(&map_idr_lock, flags);
483 }
484 
485 #ifdef CONFIG_MEMCG
bpf_map_save_memcg(struct bpf_map * map)486 static void bpf_map_save_memcg(struct bpf_map *map)
487 {
488 	/* Currently if a map is created by a process belonging to the root
489 	 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
490 	 * So we have to check map->objcg for being NULL each time it's
491 	 * being used.
492 	 */
493 	if (memcg_bpf_enabled())
494 		map->objcg = get_obj_cgroup_from_current();
495 }
496 
bpf_map_release_memcg(struct bpf_map * map)497 static void bpf_map_release_memcg(struct bpf_map *map)
498 {
499 	if (map->objcg)
500 		obj_cgroup_put(map->objcg);
501 }
502 
bpf_map_get_memcg(const struct bpf_map * map)503 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
504 {
505 	if (map->objcg)
506 		return get_mem_cgroup_from_objcg(map->objcg);
507 
508 	return root_mem_cgroup;
509 }
510 
bpf_map_memcg_enter(const struct bpf_map * map,struct mem_cgroup ** old_memcg,struct mem_cgroup ** new_memcg)511 void bpf_map_memcg_enter(const struct bpf_map *map, struct mem_cgroup **old_memcg,
512 			 struct mem_cgroup **new_memcg)
513 {
514 	*new_memcg = bpf_map_get_memcg(map);
515 	*old_memcg = set_active_memcg(*new_memcg);
516 }
517 
bpf_map_memcg_exit(struct mem_cgroup * old_memcg,struct mem_cgroup * new_memcg)518 void bpf_map_memcg_exit(struct mem_cgroup *old_memcg,
519 			struct mem_cgroup *new_memcg)
520 {
521 	set_active_memcg(old_memcg);
522 	mem_cgroup_put(new_memcg);
523 }
524 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)525 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
526 			   int node)
527 {
528 	struct mem_cgroup *memcg, *old_memcg;
529 	void *ptr;
530 
531 	bpf_map_memcg_enter(map, &old_memcg, &memcg);
532 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
533 	bpf_map_memcg_exit(old_memcg, memcg);
534 
535 	return ptr;
536 }
537 
bpf_map_kmalloc_nolock(const struct bpf_map * map,size_t size,gfp_t flags,int node)538 void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags,
539 			     int node)
540 {
541 	struct mem_cgroup *memcg, *old_memcg;
542 	void *ptr;
543 
544 	bpf_map_memcg_enter(map, &old_memcg, &memcg);
545 	ptr = kmalloc_nolock(size, flags | __GFP_ACCOUNT, node);
546 	bpf_map_memcg_exit(old_memcg, memcg);
547 
548 	return ptr;
549 }
550 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)551 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
552 {
553 	struct mem_cgroup *memcg, *old_memcg;
554 	void *ptr;
555 
556 	bpf_map_memcg_enter(map, &old_memcg, &memcg);
557 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
558 	bpf_map_memcg_exit(old_memcg, memcg);
559 
560 	return ptr;
561 }
562 
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)563 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
564 		       gfp_t flags)
565 {
566 	struct mem_cgroup *memcg, *old_memcg;
567 	void *ptr;
568 
569 	bpf_map_memcg_enter(map, &old_memcg, &memcg);
570 	ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
571 	bpf_map_memcg_exit(old_memcg, memcg);
572 
573 	return ptr;
574 }
575 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)576 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
577 				    size_t align, gfp_t flags)
578 {
579 	struct mem_cgroup *memcg, *old_memcg;
580 	void __percpu *ptr;
581 
582 	bpf_map_memcg_enter(map, &old_memcg, &memcg);
583 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
584 	bpf_map_memcg_exit(old_memcg, memcg);
585 
586 	return ptr;
587 }
588 
589 #else
bpf_map_save_memcg(struct bpf_map * map)590 static void bpf_map_save_memcg(struct bpf_map *map)
591 {
592 }
593 
bpf_map_release_memcg(struct bpf_map * map)594 static void bpf_map_release_memcg(struct bpf_map *map)
595 {
596 }
597 #endif
598 
can_alloc_pages(void)599 static bool can_alloc_pages(void)
600 {
601 	return preempt_count() == 0 && !irqs_disabled() &&
602 		!IS_ENABLED(CONFIG_PREEMPT_RT);
603 }
604 
__bpf_alloc_page(int nid)605 static struct page *__bpf_alloc_page(int nid)
606 {
607 	if (!can_alloc_pages())
608 		return alloc_pages_nolock(__GFP_ACCOUNT, nid, 0);
609 
610 	return alloc_pages_node(nid,
611 				GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
612 				| __GFP_NOWARN,
613 				0);
614 }
615 
bpf_map_alloc_pages(const struct bpf_map * map,int nid,unsigned long nr_pages,struct page ** pages)616 int bpf_map_alloc_pages(const struct bpf_map *map, int nid,
617 			unsigned long nr_pages, struct page **pages)
618 {
619 	unsigned long i, j;
620 	struct page *pg;
621 	int ret = 0;
622 
623 	for (i = 0; i < nr_pages; i++) {
624 		pg = __bpf_alloc_page(nid);
625 
626 		if (pg) {
627 			pages[i] = pg;
628 			continue;
629 		}
630 		for (j = 0; j < i; j++)
631 			free_pages_nolock(pages[j], 0);
632 		ret = -ENOMEM;
633 		break;
634 	}
635 
636 	return ret;
637 }
638 
639 
btf_field_cmp(const void * a,const void * b)640 static int btf_field_cmp(const void *a, const void *b)
641 {
642 	const struct btf_field *f1 = a, *f2 = b;
643 
644 	if (f1->offset < f2->offset)
645 		return -1;
646 	else if (f1->offset > f2->offset)
647 		return 1;
648 	return 0;
649 }
650 
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)651 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
652 				  u32 field_mask)
653 {
654 	struct btf_field *field;
655 
656 	if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
657 		return NULL;
658 	field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
659 	if (!field || !(field->type & field_mask))
660 		return NULL;
661 	return field;
662 }
663 
btf_record_free(struct btf_record * rec)664 void btf_record_free(struct btf_record *rec)
665 {
666 	int i;
667 
668 	if (IS_ERR_OR_NULL(rec))
669 		return;
670 	for (i = 0; i < rec->cnt; i++) {
671 		switch (rec->fields[i].type) {
672 		case BPF_KPTR_UNREF:
673 		case BPF_KPTR_REF:
674 		case BPF_KPTR_PERCPU:
675 		case BPF_UPTR:
676 			if (rec->fields[i].kptr.module)
677 				module_put(rec->fields[i].kptr.module);
678 			if (btf_is_kernel(rec->fields[i].kptr.btf))
679 				btf_put(rec->fields[i].kptr.btf);
680 			break;
681 		case BPF_LIST_HEAD:
682 		case BPF_LIST_NODE:
683 		case BPF_RB_ROOT:
684 		case BPF_RB_NODE:
685 		case BPF_SPIN_LOCK:
686 		case BPF_RES_SPIN_LOCK:
687 		case BPF_TIMER:
688 		case BPF_REFCOUNT:
689 		case BPF_WORKQUEUE:
690 		case BPF_TASK_WORK:
691 			/* Nothing to release */
692 			break;
693 		default:
694 			WARN_ON_ONCE(1);
695 			continue;
696 		}
697 	}
698 	kfree(rec);
699 }
700 
bpf_map_free_record(struct bpf_map * map)701 void bpf_map_free_record(struct bpf_map *map)
702 {
703 	btf_record_free(map->record);
704 	map->record = NULL;
705 }
706 
btf_record_dup(const struct btf_record * rec)707 struct btf_record *btf_record_dup(const struct btf_record *rec)
708 {
709 	const struct btf_field *fields;
710 	struct btf_record *new_rec;
711 	int ret, size, i;
712 
713 	if (IS_ERR_OR_NULL(rec))
714 		return NULL;
715 	size = struct_size(rec, fields, rec->cnt);
716 	new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
717 	if (!new_rec)
718 		return ERR_PTR(-ENOMEM);
719 	/* Do a deep copy of the btf_record */
720 	fields = rec->fields;
721 	new_rec->cnt = 0;
722 	for (i = 0; i < rec->cnt; i++) {
723 		switch (fields[i].type) {
724 		case BPF_KPTR_UNREF:
725 		case BPF_KPTR_REF:
726 		case BPF_KPTR_PERCPU:
727 		case BPF_UPTR:
728 			if (btf_is_kernel(fields[i].kptr.btf))
729 				btf_get(fields[i].kptr.btf);
730 			if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
731 				ret = -ENXIO;
732 				goto free;
733 			}
734 			break;
735 		case BPF_LIST_HEAD:
736 		case BPF_LIST_NODE:
737 		case BPF_RB_ROOT:
738 		case BPF_RB_NODE:
739 		case BPF_SPIN_LOCK:
740 		case BPF_RES_SPIN_LOCK:
741 		case BPF_TIMER:
742 		case BPF_REFCOUNT:
743 		case BPF_WORKQUEUE:
744 		case BPF_TASK_WORK:
745 			/* Nothing to acquire */
746 			break;
747 		default:
748 			ret = -EFAULT;
749 			WARN_ON_ONCE(1);
750 			goto free;
751 		}
752 		new_rec->cnt++;
753 	}
754 	return new_rec;
755 free:
756 	btf_record_free(new_rec);
757 	return ERR_PTR(ret);
758 }
759 
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)760 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
761 {
762 	bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
763 	int size;
764 
765 	if (!a_has_fields && !b_has_fields)
766 		return true;
767 	if (a_has_fields != b_has_fields)
768 		return false;
769 	if (rec_a->cnt != rec_b->cnt)
770 		return false;
771 	size = struct_size(rec_a, fields, rec_a->cnt);
772 	/* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
773 	 * members are zeroed out. So memcmp is safe to do without worrying
774 	 * about padding/unused fields.
775 	 *
776 	 * While spin_lock, timer, and kptr have no relation to map BTF,
777 	 * list_head metadata is specific to map BTF, the btf and value_rec
778 	 * members in particular. btf is the map BTF, while value_rec points to
779 	 * btf_record in that map BTF.
780 	 *
781 	 * So while by default, we don't rely on the map BTF (which the records
782 	 * were parsed from) matching for both records, which is not backwards
783 	 * compatible, in case list_head is part of it, we implicitly rely on
784 	 * that by way of depending on memcmp succeeding for it.
785 	 */
786 	return !memcmp(rec_a, rec_b, size);
787 }
788 
bpf_obj_free_timer(const struct btf_record * rec,void * obj)789 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
790 {
791 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
792 		return;
793 	bpf_timer_cancel_and_free(obj + rec->timer_off);
794 }
795 
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)796 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
797 {
798 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
799 		return;
800 	bpf_wq_cancel_and_free(obj + rec->wq_off);
801 }
802 
bpf_obj_free_task_work(const struct btf_record * rec,void * obj)803 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj)
804 {
805 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK)))
806 		return;
807 	bpf_task_work_cancel_and_free(obj + rec->task_work_off);
808 }
809 
bpf_obj_free_fields(const struct btf_record * rec,void * obj)810 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
811 {
812 	const struct btf_field *fields;
813 	int i;
814 
815 	if (IS_ERR_OR_NULL(rec))
816 		return;
817 	fields = rec->fields;
818 	for (i = 0; i < rec->cnt; i++) {
819 		struct btf_struct_meta *pointee_struct_meta;
820 		const struct btf_field *field = &fields[i];
821 		void *field_ptr = obj + field->offset;
822 		void *xchgd_field;
823 
824 		switch (fields[i].type) {
825 		case BPF_SPIN_LOCK:
826 		case BPF_RES_SPIN_LOCK:
827 			break;
828 		case BPF_TIMER:
829 			bpf_timer_cancel_and_free(field_ptr);
830 			break;
831 		case BPF_WORKQUEUE:
832 			bpf_wq_cancel_and_free(field_ptr);
833 			break;
834 		case BPF_TASK_WORK:
835 			bpf_task_work_cancel_and_free(field_ptr);
836 			break;
837 		case BPF_KPTR_UNREF:
838 			WRITE_ONCE(*(u64 *)field_ptr, 0);
839 			break;
840 		case BPF_KPTR_REF:
841 		case BPF_KPTR_PERCPU:
842 			xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
843 			if (!xchgd_field)
844 				break;
845 
846 			if (!btf_is_kernel(field->kptr.btf)) {
847 				pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
848 									   field->kptr.btf_id);
849 				__bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
850 								 pointee_struct_meta->record : NULL,
851 								 fields[i].type == BPF_KPTR_PERCPU);
852 			} else {
853 				field->kptr.dtor(xchgd_field);
854 			}
855 			break;
856 		case BPF_UPTR:
857 			/* The caller ensured that no one is using the uptr */
858 			unpin_uptr_kaddr(*(void **)field_ptr);
859 			break;
860 		case BPF_LIST_HEAD:
861 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
862 				continue;
863 			bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
864 			break;
865 		case BPF_RB_ROOT:
866 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
867 				continue;
868 			bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
869 			break;
870 		case BPF_LIST_NODE:
871 		case BPF_RB_NODE:
872 		case BPF_REFCOUNT:
873 			break;
874 		default:
875 			WARN_ON_ONCE(1);
876 			continue;
877 		}
878 	}
879 }
880 
bpf_map_free(struct bpf_map * map)881 static void bpf_map_free(struct bpf_map *map)
882 {
883 	struct btf_record *rec = map->record;
884 	struct btf *btf = map->btf;
885 
886 	/* implementation dependent freeing. Disabling migration to simplify
887 	 * the free of values or special fields allocated from bpf memory
888 	 * allocator.
889 	 */
890 	kfree(map->excl_prog_sha);
891 	migrate_disable();
892 	map->ops->map_free(map);
893 	migrate_enable();
894 
895 	/* Delay freeing of btf_record for maps, as map_free
896 	 * callback usually needs access to them. It is better to do it here
897 	 * than require each callback to do the free itself manually.
898 	 *
899 	 * Note that the btf_record stashed in map->inner_map_meta->record was
900 	 * already freed using the map_free callback for map in map case which
901 	 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
902 	 * template bpf_map struct used during verification.
903 	 */
904 	btf_record_free(rec);
905 	/* Delay freeing of btf for maps, as map_free callback may need
906 	 * struct_meta info which will be freed with btf_put().
907 	 */
908 	btf_put(btf);
909 }
910 
911 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)912 static void bpf_map_free_deferred(struct work_struct *work)
913 {
914 	struct bpf_map *map = container_of(work, struct bpf_map, work);
915 
916 	security_bpf_map_free(map);
917 	bpf_map_release_memcg(map);
918 	bpf_map_owner_free(map);
919 	bpf_map_free(map);
920 }
921 
bpf_map_put_uref(struct bpf_map * map)922 static void bpf_map_put_uref(struct bpf_map *map)
923 {
924 	if (atomic64_dec_and_test(&map->usercnt)) {
925 		if (map->ops->map_release_uref)
926 			map->ops->map_release_uref(map);
927 	}
928 }
929 
bpf_map_free_in_work(struct bpf_map * map)930 static void bpf_map_free_in_work(struct bpf_map *map)
931 {
932 	INIT_WORK(&map->work, bpf_map_free_deferred);
933 	/* Avoid spawning kworkers, since they all might contend
934 	 * for the same mutex like slab_mutex.
935 	 */
936 	queue_work(system_dfl_wq, &map->work);
937 }
938 
bpf_map_free_rcu_gp(struct rcu_head * rcu)939 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
940 {
941 	bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
942 }
943 
944 /* decrement map refcnt and schedule it for freeing via workqueue
945  * (underlying map implementation ops->map_free() might sleep)
946  */
bpf_map_put(struct bpf_map * map)947 void bpf_map_put(struct bpf_map *map)
948 {
949 	if (atomic64_dec_and_test(&map->refcnt)) {
950 		/* bpf_map_free_id() must be called first */
951 		bpf_map_free_id(map);
952 
953 		WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
954 		/* RCU tasks trace grace period implies RCU grace period. */
955 		if (READ_ONCE(map->free_after_mult_rcu_gp))
956 			call_rcu_tasks_trace(&map->rcu, bpf_map_free_rcu_gp);
957 		else if (READ_ONCE(map->free_after_rcu_gp))
958 			call_rcu(&map->rcu, bpf_map_free_rcu_gp);
959 		else
960 			bpf_map_free_in_work(map);
961 	}
962 }
963 EXPORT_SYMBOL_GPL(bpf_map_put);
964 
bpf_map_put_with_uref(struct bpf_map * map)965 void bpf_map_put_with_uref(struct bpf_map *map)
966 {
967 	bpf_map_put_uref(map);
968 	bpf_map_put(map);
969 }
970 
bpf_map_release(struct inode * inode,struct file * filp)971 static int bpf_map_release(struct inode *inode, struct file *filp)
972 {
973 	struct bpf_map *map = filp->private_data;
974 
975 	if (map->ops->map_release)
976 		map->ops->map_release(map, filp);
977 
978 	bpf_map_put_with_uref(map);
979 	return 0;
980 }
981 
map_get_sys_perms(struct bpf_map * map,struct fd f)982 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
983 {
984 	fmode_t mode = fd_file(f)->f_mode;
985 
986 	/* Our file permissions may have been overridden by global
987 	 * map permissions facing syscall side.
988 	 */
989 	if (READ_ONCE(map->frozen))
990 		mode &= ~FMODE_CAN_WRITE;
991 	return mode;
992 }
993 
994 #ifdef CONFIG_PROC_FS
995 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)996 static u64 bpf_map_memory_usage(const struct bpf_map *map)
997 {
998 	return map->ops->map_mem_usage(map);
999 }
1000 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)1001 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
1002 {
1003 	struct bpf_map *map = filp->private_data;
1004 	u32 type = 0, jited = 0;
1005 
1006 	spin_lock(&map->owner_lock);
1007 	if (map->owner) {
1008 		type  = map->owner->type;
1009 		jited = map->owner->jited;
1010 	}
1011 	spin_unlock(&map->owner_lock);
1012 
1013 	seq_printf(m,
1014 		   "map_type:\t%u\n"
1015 		   "key_size:\t%u\n"
1016 		   "value_size:\t%u\n"
1017 		   "max_entries:\t%u\n"
1018 		   "map_flags:\t%#x\n"
1019 		   "map_extra:\t%#llx\n"
1020 		   "memlock:\t%llu\n"
1021 		   "map_id:\t%u\n"
1022 		   "frozen:\t%u\n",
1023 		   map->map_type,
1024 		   map->key_size,
1025 		   map->value_size,
1026 		   map->max_entries,
1027 		   map->map_flags,
1028 		   (unsigned long long)map->map_extra,
1029 		   bpf_map_memory_usage(map),
1030 		   map->id,
1031 		   READ_ONCE(map->frozen));
1032 	if (type) {
1033 		seq_printf(m, "owner_prog_type:\t%u\n", type);
1034 		seq_printf(m, "owner_jited:\t%u\n", jited);
1035 	}
1036 }
1037 #endif
1038 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)1039 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
1040 			      loff_t *ppos)
1041 {
1042 	/* We need this handler such that alloc_file() enables
1043 	 * f_mode with FMODE_CAN_READ.
1044 	 */
1045 	return -EINVAL;
1046 }
1047 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1048 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1049 			       size_t siz, loff_t *ppos)
1050 {
1051 	/* We need this handler such that alloc_file() enables
1052 	 * f_mode with FMODE_CAN_WRITE.
1053 	 */
1054 	return -EINVAL;
1055 }
1056 
1057 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1058 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1059 {
1060 	struct bpf_map *map = vma->vm_file->private_data;
1061 
1062 	if (vma->vm_flags & VM_MAYWRITE)
1063 		bpf_map_write_active_inc(map);
1064 }
1065 
1066 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1067 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1068 {
1069 	struct bpf_map *map = vma->vm_file->private_data;
1070 
1071 	if (vma->vm_flags & VM_MAYWRITE)
1072 		bpf_map_write_active_dec(map);
1073 }
1074 
1075 static const struct vm_operations_struct bpf_map_default_vmops = {
1076 	.open		= bpf_map_mmap_open,
1077 	.close		= bpf_map_mmap_close,
1078 };
1079 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1080 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1081 {
1082 	struct bpf_map *map = filp->private_data;
1083 	int err = 0;
1084 
1085 	if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1086 		return -ENOTSUPP;
1087 
1088 	if (!(vma->vm_flags & VM_SHARED))
1089 		return -EINVAL;
1090 
1091 	mutex_lock(&map->freeze_mutex);
1092 
1093 	if (vma->vm_flags & VM_WRITE) {
1094 		if (map->frozen) {
1095 			err = -EPERM;
1096 			goto out;
1097 		}
1098 		/* map is meant to be read-only, so do not allow mapping as
1099 		 * writable, because it's possible to leak a writable page
1100 		 * reference and allows user-space to still modify it after
1101 		 * freezing, while verifier will assume contents do not change
1102 		 */
1103 		if (map->map_flags & BPF_F_RDONLY_PROG) {
1104 			err = -EACCES;
1105 			goto out;
1106 		}
1107 		bpf_map_write_active_inc(map);
1108 	}
1109 out:
1110 	mutex_unlock(&map->freeze_mutex);
1111 	if (err)
1112 		return err;
1113 
1114 	/* set default open/close callbacks */
1115 	vma->vm_ops = &bpf_map_default_vmops;
1116 	vma->vm_private_data = map;
1117 	vm_flags_clear(vma, VM_MAYEXEC);
1118 	/* If mapping is read-only, then disallow potentially re-mapping with
1119 	 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1120 	 * means that as far as BPF map's memory-mapped VMAs are concerned,
1121 	 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1122 	 * both should be set, so we can forget about VM_MAYWRITE and always
1123 	 * check just VM_WRITE
1124 	 */
1125 	if (!(vma->vm_flags & VM_WRITE))
1126 		vm_flags_clear(vma, VM_MAYWRITE);
1127 
1128 	err = map->ops->map_mmap(map, vma);
1129 	if (err) {
1130 		if (vma->vm_flags & VM_WRITE)
1131 			bpf_map_write_active_dec(map);
1132 	}
1133 
1134 	return err;
1135 }
1136 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1137 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1138 {
1139 	struct bpf_map *map = filp->private_data;
1140 
1141 	if (map->ops->map_poll)
1142 		return map->ops->map_poll(map, filp, pts);
1143 
1144 	return EPOLLERR;
1145 }
1146 
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1147 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1148 					   unsigned long len, unsigned long pgoff,
1149 					   unsigned long flags)
1150 {
1151 	struct bpf_map *map = filp->private_data;
1152 
1153 	if (map->ops->map_get_unmapped_area)
1154 		return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1155 #ifdef CONFIG_MMU
1156 	return mm_get_unmapped_area(filp, addr, len, pgoff, flags);
1157 #else
1158 	return addr;
1159 #endif
1160 }
1161 
1162 const struct file_operations bpf_map_fops = {
1163 #ifdef CONFIG_PROC_FS
1164 	.show_fdinfo	= bpf_map_show_fdinfo,
1165 #endif
1166 	.release	= bpf_map_release,
1167 	.read		= bpf_dummy_read,
1168 	.write		= bpf_dummy_write,
1169 	.mmap		= bpf_map_mmap,
1170 	.poll		= bpf_map_poll,
1171 	.get_unmapped_area = bpf_get_unmapped_area,
1172 };
1173 
bpf_map_new_fd(struct bpf_map * map,int flags)1174 int bpf_map_new_fd(struct bpf_map *map, int flags)
1175 {
1176 	int ret;
1177 
1178 	ret = security_bpf_map(map, OPEN_FMODE(flags));
1179 	if (ret < 0)
1180 		return ret;
1181 
1182 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1183 				flags | O_CLOEXEC);
1184 }
1185 
bpf_get_file_flag(int flags)1186 int bpf_get_file_flag(int flags)
1187 {
1188 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1189 		return -EINVAL;
1190 	if (flags & BPF_F_RDONLY)
1191 		return O_RDONLY;
1192 	if (flags & BPF_F_WRONLY)
1193 		return O_WRONLY;
1194 	return O_RDWR;
1195 }
1196 
1197 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1198 #define CHECK_ATTR(CMD) \
1199 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1200 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
1201 		   sizeof(*attr) - \
1202 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1203 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
1204 
1205 /* dst and src must have at least "size" number of bytes.
1206  * Return strlen on success and < 0 on error.
1207  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1208 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1209 {
1210 	const char *end = src + size;
1211 	const char *orig_src = src;
1212 
1213 	memset(dst, 0, size);
1214 	/* Copy all isalnum(), '_' and '.' chars. */
1215 	while (src < end && *src) {
1216 		if (!isalnum(*src) &&
1217 		    *src != '_' && *src != '.')
1218 			return -EINVAL;
1219 		*dst++ = *src++;
1220 	}
1221 
1222 	/* No '\0' found in "size" number of bytes */
1223 	if (src == end)
1224 		return -EINVAL;
1225 
1226 	return src - orig_src;
1227 }
1228 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy);
1229 
map_check_no_btf(struct bpf_map * map,const struct btf * btf,const struct btf_type * key_type,const struct btf_type * value_type)1230 int map_check_no_btf(struct bpf_map *map,
1231 		     const struct btf *btf,
1232 		     const struct btf_type *key_type,
1233 		     const struct btf_type *value_type)
1234 {
1235 	return -ENOTSUPP;
1236 }
1237 
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1238 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1239 			 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1240 {
1241 	const struct btf_type *key_type, *value_type;
1242 	u32 key_size, value_size;
1243 	int ret = 0;
1244 
1245 	/* Some maps allow key to be unspecified. */
1246 	if (btf_key_id) {
1247 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1248 		if (!key_type || key_size != map->key_size)
1249 			return -EINVAL;
1250 	} else {
1251 		key_type = btf_type_by_id(btf, 0);
1252 		if (!map->ops->map_check_btf)
1253 			return -EINVAL;
1254 	}
1255 
1256 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1257 	if (!value_type || value_size != map->value_size)
1258 		return -EINVAL;
1259 
1260 	map->record = btf_parse_fields(btf, value_type,
1261 				       BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1262 				       BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR |
1263 				       BPF_TASK_WORK,
1264 				       map->value_size);
1265 	if (!IS_ERR_OR_NULL(map->record)) {
1266 		int i;
1267 
1268 		if (!bpf_token_capable(token, CAP_BPF)) {
1269 			ret = -EPERM;
1270 			goto free_map_tab;
1271 		}
1272 		if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1273 			ret = -EACCES;
1274 			goto free_map_tab;
1275 		}
1276 		for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1277 			switch (map->record->field_mask & (1 << i)) {
1278 			case 0:
1279 				continue;
1280 			case BPF_SPIN_LOCK:
1281 			case BPF_RES_SPIN_LOCK:
1282 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1283 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1284 				    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1285 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1286 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1287 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1288 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1289 					ret = -EOPNOTSUPP;
1290 					goto free_map_tab;
1291 				}
1292 				break;
1293 			case BPF_TIMER:
1294 			case BPF_WORKQUEUE:
1295 			case BPF_TASK_WORK:
1296 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1297 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1298 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1299 					ret = -EOPNOTSUPP;
1300 					goto free_map_tab;
1301 				}
1302 				break;
1303 			case BPF_KPTR_UNREF:
1304 			case BPF_KPTR_REF:
1305 			case BPF_KPTR_PERCPU:
1306 			case BPF_REFCOUNT:
1307 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1308 				    map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1309 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1310 				    map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1311 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1312 				    map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1313 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1314 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1315 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1316 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1317 					ret = -EOPNOTSUPP;
1318 					goto free_map_tab;
1319 				}
1320 				break;
1321 			case BPF_UPTR:
1322 				if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1323 					ret = -EOPNOTSUPP;
1324 					goto free_map_tab;
1325 				}
1326 				break;
1327 			case BPF_LIST_HEAD:
1328 			case BPF_RB_ROOT:
1329 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1330 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1331 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1332 					ret = -EOPNOTSUPP;
1333 					goto free_map_tab;
1334 				}
1335 				break;
1336 			default:
1337 				/* Fail if map_type checks are missing for a field type */
1338 				ret = -EOPNOTSUPP;
1339 				goto free_map_tab;
1340 			}
1341 		}
1342 	}
1343 
1344 	ret = btf_check_and_fixup_fields(btf, map->record);
1345 	if (ret < 0)
1346 		goto free_map_tab;
1347 
1348 	if (map->ops->map_check_btf) {
1349 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1350 		if (ret < 0)
1351 			goto free_map_tab;
1352 	}
1353 
1354 	return ret;
1355 free_map_tab:
1356 	bpf_map_free_record(map);
1357 	return ret;
1358 }
1359 
1360 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size
1361 /* called via syscall */
map_create(union bpf_attr * attr,bpfptr_t uattr)1362 static int map_create(union bpf_attr *attr, bpfptr_t uattr)
1363 {
1364 	const struct bpf_map_ops *ops;
1365 	struct bpf_token *token = NULL;
1366 	int numa_node = bpf_map_attr_numa_node(attr);
1367 	u32 map_type = attr->map_type;
1368 	struct bpf_map *map;
1369 	bool token_flag;
1370 	int f_flags;
1371 	int err;
1372 
1373 	err = CHECK_ATTR(BPF_MAP_CREATE);
1374 	if (err)
1375 		return -EINVAL;
1376 
1377 	/* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1378 	 * to avoid per-map type checks tripping on unknown flag
1379 	 */
1380 	token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1381 	attr->map_flags &= ~BPF_F_TOKEN_FD;
1382 
1383 	if (attr->btf_vmlinux_value_type_id) {
1384 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1385 		    attr->btf_key_type_id || attr->btf_value_type_id)
1386 			return -EINVAL;
1387 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1388 		return -EINVAL;
1389 	}
1390 
1391 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1392 	    attr->map_type != BPF_MAP_TYPE_ARENA &&
1393 	    attr->map_extra != 0)
1394 		return -EINVAL;
1395 
1396 	f_flags = bpf_get_file_flag(attr->map_flags);
1397 	if (f_flags < 0)
1398 		return f_flags;
1399 
1400 	if (numa_node != NUMA_NO_NODE &&
1401 	    ((unsigned int)numa_node >= nr_node_ids ||
1402 	     !node_online(numa_node)))
1403 		return -EINVAL;
1404 
1405 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1406 	map_type = attr->map_type;
1407 	if (map_type >= ARRAY_SIZE(bpf_map_types))
1408 		return -EINVAL;
1409 	map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1410 	ops = bpf_map_types[map_type];
1411 	if (!ops)
1412 		return -EINVAL;
1413 
1414 	if (ops->map_alloc_check) {
1415 		err = ops->map_alloc_check(attr);
1416 		if (err)
1417 			return err;
1418 	}
1419 	if (attr->map_ifindex)
1420 		ops = &bpf_map_offload_ops;
1421 	if (!ops->map_mem_usage)
1422 		return -EINVAL;
1423 
1424 	if (token_flag) {
1425 		token = bpf_token_get_from_fd(attr->map_token_fd);
1426 		if (IS_ERR(token))
1427 			return PTR_ERR(token);
1428 
1429 		/* if current token doesn't grant map creation permissions,
1430 		 * then we can't use this token, so ignore it and rely on
1431 		 * system-wide capabilities checks
1432 		 */
1433 		if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1434 		    !bpf_token_allow_map_type(token, attr->map_type)) {
1435 			bpf_token_put(token);
1436 			token = NULL;
1437 		}
1438 	}
1439 
1440 	err = -EPERM;
1441 
1442 	/* Intent here is for unprivileged_bpf_disabled to block BPF map
1443 	 * creation for unprivileged users; other actions depend
1444 	 * on fd availability and access to bpffs, so are dependent on
1445 	 * object creation success. Even with unprivileged BPF disabled,
1446 	 * capability checks are still carried out.
1447 	 */
1448 	if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1449 		goto put_token;
1450 
1451 	/* check privileged map type permissions */
1452 	switch (map_type) {
1453 	case BPF_MAP_TYPE_ARRAY:
1454 	case BPF_MAP_TYPE_PERCPU_ARRAY:
1455 	case BPF_MAP_TYPE_PROG_ARRAY:
1456 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1457 	case BPF_MAP_TYPE_CGROUP_ARRAY:
1458 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1459 	case BPF_MAP_TYPE_HASH:
1460 	case BPF_MAP_TYPE_PERCPU_HASH:
1461 	case BPF_MAP_TYPE_HASH_OF_MAPS:
1462 	case BPF_MAP_TYPE_RINGBUF:
1463 	case BPF_MAP_TYPE_USER_RINGBUF:
1464 	case BPF_MAP_TYPE_CGROUP_STORAGE:
1465 	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1466 		/* unprivileged */
1467 		break;
1468 	case BPF_MAP_TYPE_SK_STORAGE:
1469 	case BPF_MAP_TYPE_INODE_STORAGE:
1470 	case BPF_MAP_TYPE_TASK_STORAGE:
1471 	case BPF_MAP_TYPE_CGRP_STORAGE:
1472 	case BPF_MAP_TYPE_BLOOM_FILTER:
1473 	case BPF_MAP_TYPE_LPM_TRIE:
1474 	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1475 	case BPF_MAP_TYPE_STACK_TRACE:
1476 	case BPF_MAP_TYPE_QUEUE:
1477 	case BPF_MAP_TYPE_STACK:
1478 	case BPF_MAP_TYPE_LRU_HASH:
1479 	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1480 	case BPF_MAP_TYPE_STRUCT_OPS:
1481 	case BPF_MAP_TYPE_CPUMAP:
1482 	case BPF_MAP_TYPE_ARENA:
1483 	case BPF_MAP_TYPE_INSN_ARRAY:
1484 		if (!bpf_token_capable(token, CAP_BPF))
1485 			goto put_token;
1486 		break;
1487 	case BPF_MAP_TYPE_SOCKMAP:
1488 	case BPF_MAP_TYPE_SOCKHASH:
1489 	case BPF_MAP_TYPE_DEVMAP:
1490 	case BPF_MAP_TYPE_DEVMAP_HASH:
1491 	case BPF_MAP_TYPE_XSKMAP:
1492 		if (!bpf_token_capable(token, CAP_NET_ADMIN))
1493 			goto put_token;
1494 		break;
1495 	default:
1496 		WARN(1, "unsupported map type %d", map_type);
1497 		goto put_token;
1498 	}
1499 
1500 	map = ops->map_alloc(attr);
1501 	if (IS_ERR(map)) {
1502 		err = PTR_ERR(map);
1503 		goto put_token;
1504 	}
1505 	map->ops = ops;
1506 	map->map_type = map_type;
1507 
1508 	err = bpf_obj_name_cpy(map->name, attr->map_name,
1509 			       sizeof(attr->map_name));
1510 	if (err < 0)
1511 		goto free_map;
1512 
1513 	preempt_disable();
1514 	map->cookie = gen_cookie_next(&bpf_map_cookie);
1515 	preempt_enable();
1516 
1517 	atomic64_set(&map->refcnt, 1);
1518 	atomic64_set(&map->usercnt, 1);
1519 	mutex_init(&map->freeze_mutex);
1520 	spin_lock_init(&map->owner_lock);
1521 
1522 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
1523 	    /* Even the map's value is a kernel's struct,
1524 	     * the bpf_prog.o must have BTF to begin with
1525 	     * to figure out the corresponding kernel's
1526 	     * counter part.  Thus, attr->btf_fd has
1527 	     * to be valid also.
1528 	     */
1529 	    attr->btf_vmlinux_value_type_id) {
1530 		struct btf *btf;
1531 
1532 		btf = btf_get_by_fd(attr->btf_fd);
1533 		if (IS_ERR(btf)) {
1534 			err = PTR_ERR(btf);
1535 			goto free_map;
1536 		}
1537 		if (btf_is_kernel(btf)) {
1538 			btf_put(btf);
1539 			err = -EACCES;
1540 			goto free_map;
1541 		}
1542 		map->btf = btf;
1543 
1544 		if (attr->btf_value_type_id) {
1545 			err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1546 					    attr->btf_value_type_id);
1547 			if (err)
1548 				goto free_map;
1549 		}
1550 
1551 		map->btf_key_type_id = attr->btf_key_type_id;
1552 		map->btf_value_type_id = attr->btf_value_type_id;
1553 		map->btf_vmlinux_value_type_id =
1554 			attr->btf_vmlinux_value_type_id;
1555 	}
1556 
1557 	if (attr->excl_prog_hash) {
1558 		bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel);
1559 
1560 		if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) {
1561 			err = -EINVAL;
1562 			goto free_map;
1563 		}
1564 
1565 		map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
1566 		if (!map->excl_prog_sha) {
1567 			err = -ENOMEM;
1568 			goto free_map;
1569 		}
1570 
1571 		if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) {
1572 			err = -EFAULT;
1573 			goto free_map;
1574 		}
1575 	} else if (attr->excl_prog_hash_size) {
1576 		err = -EINVAL;
1577 		goto free_map;
1578 	}
1579 
1580 	err = security_bpf_map_create(map, attr, token, uattr.is_kernel);
1581 	if (err)
1582 		goto free_map_sec;
1583 
1584 	err = bpf_map_alloc_id(map);
1585 	if (err)
1586 		goto free_map_sec;
1587 
1588 	bpf_map_save_memcg(map);
1589 	bpf_token_put(token);
1590 
1591 	err = bpf_map_new_fd(map, f_flags);
1592 	if (err < 0) {
1593 		/* failed to allocate fd.
1594 		 * bpf_map_put_with_uref() is needed because the above
1595 		 * bpf_map_alloc_id() has published the map
1596 		 * to the userspace and the userspace may
1597 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1598 		 */
1599 		bpf_map_put_with_uref(map);
1600 		return err;
1601 	}
1602 
1603 	return err;
1604 
1605 free_map_sec:
1606 	security_bpf_map_free(map);
1607 free_map:
1608 	bpf_map_free(map);
1609 put_token:
1610 	bpf_token_put(token);
1611 	return err;
1612 }
1613 
bpf_map_inc(struct bpf_map * map)1614 void bpf_map_inc(struct bpf_map *map)
1615 {
1616 	atomic64_inc(&map->refcnt);
1617 }
1618 EXPORT_SYMBOL_GPL(bpf_map_inc);
1619 
bpf_map_inc_with_uref(struct bpf_map * map)1620 void bpf_map_inc_with_uref(struct bpf_map *map)
1621 {
1622 	atomic64_inc(&map->refcnt);
1623 	atomic64_inc(&map->usercnt);
1624 }
1625 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1626 
bpf_map_get(u32 ufd)1627 struct bpf_map *bpf_map_get(u32 ufd)
1628 {
1629 	CLASS(fd, f)(ufd);
1630 	struct bpf_map *map = __bpf_map_get(f);
1631 
1632 	if (!IS_ERR(map))
1633 		bpf_map_inc(map);
1634 
1635 	return map;
1636 }
1637 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL");
1638 
bpf_map_get_with_uref(u32 ufd)1639 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1640 {
1641 	CLASS(fd, f)(ufd);
1642 	struct bpf_map *map = __bpf_map_get(f);
1643 
1644 	if (!IS_ERR(map))
1645 		bpf_map_inc_with_uref(map);
1646 
1647 	return map;
1648 }
1649 
1650 /* map_idr_lock should have been held or the map should have been
1651  * protected by rcu read lock.
1652  */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1653 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1654 {
1655 	int refold;
1656 
1657 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1658 	if (!refold)
1659 		return ERR_PTR(-ENOENT);
1660 	if (uref)
1661 		atomic64_inc(&map->usercnt);
1662 
1663 	return map;
1664 }
1665 
bpf_map_inc_not_zero(struct bpf_map * map)1666 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1667 {
1668 	lockdep_assert(rcu_read_lock_held());
1669 	return __bpf_map_inc_not_zero(map, false);
1670 }
1671 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1672 
bpf_stackmap_extract(struct bpf_map * map,void * key,void * value,bool delete)1673 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value,
1674 				bool delete)
1675 {
1676 	return -ENOTSUPP;
1677 }
1678 
__bpf_copy_key(void __user * ukey,u64 key_size)1679 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1680 {
1681 	if (key_size)
1682 		return vmemdup_user(ukey, key_size);
1683 
1684 	if (ukey)
1685 		return ERR_PTR(-EINVAL);
1686 
1687 	return NULL;
1688 }
1689 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1690 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1691 {
1692 	if (key_size)
1693 		return kvmemdup_bpfptr(ukey, key_size);
1694 
1695 	if (!bpfptr_is_null(ukey))
1696 		return ERR_PTR(-EINVAL);
1697 
1698 	return NULL;
1699 }
1700 
1701 /* last field in 'union bpf_attr' used by this command */
1702 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1703 
map_lookup_elem(union bpf_attr * attr)1704 static int map_lookup_elem(union bpf_attr *attr)
1705 {
1706 	void __user *ukey = u64_to_user_ptr(attr->key);
1707 	void __user *uvalue = u64_to_user_ptr(attr->value);
1708 	struct bpf_map *map;
1709 	void *key, *value;
1710 	u32 value_size;
1711 	int err;
1712 
1713 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1714 		return -EINVAL;
1715 
1716 	CLASS(fd, f)(attr->map_fd);
1717 	map = __bpf_map_get(f);
1718 	if (IS_ERR(map))
1719 		return PTR_ERR(map);
1720 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1721 		return -EPERM;
1722 
1723 	err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK | BPF_F_CPU);
1724 	if (err)
1725 		return err;
1726 
1727 	key = __bpf_copy_key(ukey, map->key_size);
1728 	if (IS_ERR(key))
1729 		return PTR_ERR(key);
1730 
1731 	value_size = bpf_map_value_size(map, attr->flags);
1732 
1733 	err = -ENOMEM;
1734 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1735 	if (!value)
1736 		goto free_key;
1737 
1738 	if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1739 		if (copy_from_user(value, uvalue, value_size))
1740 			err = -EFAULT;
1741 		else
1742 			err = bpf_map_copy_value(map, key, value, attr->flags);
1743 		goto free_value;
1744 	}
1745 
1746 	err = bpf_map_copy_value(map, key, value, attr->flags);
1747 	if (err)
1748 		goto free_value;
1749 
1750 	err = -EFAULT;
1751 	if (copy_to_user(uvalue, value, value_size) != 0)
1752 		goto free_value;
1753 
1754 	err = 0;
1755 
1756 free_value:
1757 	kvfree(value);
1758 free_key:
1759 	kvfree(key);
1760 	return err;
1761 }
1762 
1763 
1764 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1765 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1766 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1767 {
1768 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1769 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1770 	struct bpf_map *map;
1771 	void *key, *value;
1772 	u32 value_size;
1773 	int err;
1774 
1775 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1776 		return -EINVAL;
1777 
1778 	CLASS(fd, f)(attr->map_fd);
1779 	map = __bpf_map_get(f);
1780 	if (IS_ERR(map))
1781 		return PTR_ERR(map);
1782 	bpf_map_write_active_inc(map);
1783 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1784 		err = -EPERM;
1785 		goto err_put;
1786 	}
1787 
1788 	err = bpf_map_check_op_flags(map, attr->flags, ~0);
1789 	if (err)
1790 		goto err_put;
1791 
1792 	key = ___bpf_copy_key(ukey, map->key_size);
1793 	if (IS_ERR(key)) {
1794 		err = PTR_ERR(key);
1795 		goto err_put;
1796 	}
1797 
1798 	value_size = bpf_map_value_size(map, attr->flags);
1799 	value = kvmemdup_bpfptr(uvalue, value_size);
1800 	if (IS_ERR(value)) {
1801 		err = PTR_ERR(value);
1802 		goto free_key;
1803 	}
1804 
1805 	err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1806 	if (!err)
1807 		maybe_wait_bpf_programs(map);
1808 
1809 	kvfree(value);
1810 free_key:
1811 	kvfree(key);
1812 err_put:
1813 	bpf_map_write_active_dec(map);
1814 	return err;
1815 }
1816 
1817 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1818 
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1819 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1820 {
1821 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1822 	struct bpf_map *map;
1823 	void *key;
1824 	int err;
1825 
1826 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1827 		return -EINVAL;
1828 
1829 	CLASS(fd, f)(attr->map_fd);
1830 	map = __bpf_map_get(f);
1831 	if (IS_ERR(map))
1832 		return PTR_ERR(map);
1833 	bpf_map_write_active_inc(map);
1834 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1835 		err = -EPERM;
1836 		goto err_put;
1837 	}
1838 
1839 	key = ___bpf_copy_key(ukey, map->key_size);
1840 	if (IS_ERR(key)) {
1841 		err = PTR_ERR(key);
1842 		goto err_put;
1843 	}
1844 
1845 	if (bpf_map_is_offloaded(map)) {
1846 		err = bpf_map_offload_delete_elem(map, key);
1847 		goto out;
1848 	} else if (IS_FD_PROG_ARRAY(map) ||
1849 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1850 		/* These maps require sleepable context */
1851 		err = map->ops->map_delete_elem(map, key);
1852 		goto out;
1853 	}
1854 
1855 	bpf_disable_instrumentation();
1856 	rcu_read_lock();
1857 	err = map->ops->map_delete_elem(map, key);
1858 	rcu_read_unlock();
1859 	bpf_enable_instrumentation();
1860 	if (!err)
1861 		maybe_wait_bpf_programs(map);
1862 out:
1863 	kvfree(key);
1864 err_put:
1865 	bpf_map_write_active_dec(map);
1866 	return err;
1867 }
1868 
1869 /* last field in 'union bpf_attr' used by this command */
1870 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1871 
map_get_next_key(union bpf_attr * attr)1872 static int map_get_next_key(union bpf_attr *attr)
1873 {
1874 	void __user *ukey = u64_to_user_ptr(attr->key);
1875 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1876 	struct bpf_map *map;
1877 	void *key, *next_key;
1878 	int err;
1879 
1880 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1881 		return -EINVAL;
1882 
1883 	CLASS(fd, f)(attr->map_fd);
1884 	map = __bpf_map_get(f);
1885 	if (IS_ERR(map))
1886 		return PTR_ERR(map);
1887 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1888 		return -EPERM;
1889 
1890 	if (ukey) {
1891 		key = __bpf_copy_key(ukey, map->key_size);
1892 		if (IS_ERR(key))
1893 			return PTR_ERR(key);
1894 	} else {
1895 		key = NULL;
1896 	}
1897 
1898 	err = -ENOMEM;
1899 	next_key = kvmalloc(map->key_size, GFP_USER);
1900 	if (!next_key)
1901 		goto free_key;
1902 
1903 	if (bpf_map_is_offloaded(map)) {
1904 		err = bpf_map_offload_get_next_key(map, key, next_key);
1905 		goto out;
1906 	}
1907 
1908 	rcu_read_lock();
1909 	err = map->ops->map_get_next_key(map, key, next_key);
1910 	rcu_read_unlock();
1911 out:
1912 	if (err)
1913 		goto free_next_key;
1914 
1915 	err = -EFAULT;
1916 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1917 		goto free_next_key;
1918 
1919 	err = 0;
1920 
1921 free_next_key:
1922 	kvfree(next_key);
1923 free_key:
1924 	kvfree(key);
1925 	return err;
1926 }
1927 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1928 int generic_map_delete_batch(struct bpf_map *map,
1929 			     const union bpf_attr *attr,
1930 			     union bpf_attr __user *uattr)
1931 {
1932 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1933 	u32 cp, max_count;
1934 	int err = 0;
1935 	void *key;
1936 
1937 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1938 		return -EINVAL;
1939 
1940 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1941 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1942 		return -EINVAL;
1943 	}
1944 
1945 	max_count = attr->batch.count;
1946 	if (!max_count)
1947 		return 0;
1948 
1949 	if (put_user(0, &uattr->batch.count))
1950 		return -EFAULT;
1951 
1952 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1953 	if (!key)
1954 		return -ENOMEM;
1955 
1956 	for (cp = 0; cp < max_count; cp++) {
1957 		err = -EFAULT;
1958 		if (copy_from_user(key, keys + cp * map->key_size,
1959 				   map->key_size))
1960 			break;
1961 
1962 		if (bpf_map_is_offloaded(map)) {
1963 			err = bpf_map_offload_delete_elem(map, key);
1964 			break;
1965 		}
1966 
1967 		bpf_disable_instrumentation();
1968 		rcu_read_lock();
1969 		err = map->ops->map_delete_elem(map, key);
1970 		rcu_read_unlock();
1971 		bpf_enable_instrumentation();
1972 		if (err)
1973 			break;
1974 		cond_resched();
1975 	}
1976 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1977 		err = -EFAULT;
1978 
1979 	kvfree(key);
1980 
1981 	return err;
1982 }
1983 
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1984 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1985 			     const union bpf_attr *attr,
1986 			     union bpf_attr __user *uattr)
1987 {
1988 	void __user *values = u64_to_user_ptr(attr->batch.values);
1989 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1990 	u32 value_size, cp, max_count;
1991 	void *key, *value;
1992 	int err = 0;
1993 
1994 	err = bpf_map_check_op_flags(map, attr->batch.elem_flags,
1995 				     BPF_F_LOCK | BPF_F_CPU | BPF_F_ALL_CPUS);
1996 	if (err)
1997 		return err;
1998 
1999 	value_size = bpf_map_value_size(map, attr->batch.elem_flags);
2000 
2001 	max_count = attr->batch.count;
2002 	if (!max_count)
2003 		return 0;
2004 
2005 	if (put_user(0, &uattr->batch.count))
2006 		return -EFAULT;
2007 
2008 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2009 	if (!key)
2010 		return -ENOMEM;
2011 
2012 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2013 	if (!value) {
2014 		kvfree(key);
2015 		return -ENOMEM;
2016 	}
2017 
2018 	for (cp = 0; cp < max_count; cp++) {
2019 		err = -EFAULT;
2020 		if (copy_from_user(key, keys + cp * map->key_size,
2021 		    map->key_size) ||
2022 		    copy_from_user(value, values + cp * value_size, value_size))
2023 			break;
2024 
2025 		err = bpf_map_update_value(map, map_file, key, value,
2026 					   attr->batch.elem_flags);
2027 
2028 		if (err)
2029 			break;
2030 		cond_resched();
2031 	}
2032 
2033 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
2034 		err = -EFAULT;
2035 
2036 	kvfree(value);
2037 	kvfree(key);
2038 
2039 	return err;
2040 }
2041 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)2042 int generic_map_lookup_batch(struct bpf_map *map,
2043 				    const union bpf_attr *attr,
2044 				    union bpf_attr __user *uattr)
2045 {
2046 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
2047 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
2048 	void __user *values = u64_to_user_ptr(attr->batch.values);
2049 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
2050 	void *buf, *buf_prevkey, *prev_key, *key, *value;
2051 	u32 value_size, cp, max_count;
2052 	int err;
2053 
2054 	err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK | BPF_F_CPU);
2055 	if (err)
2056 		return err;
2057 
2058 	value_size = bpf_map_value_size(map, attr->batch.elem_flags);
2059 
2060 	max_count = attr->batch.count;
2061 	if (!max_count)
2062 		return 0;
2063 
2064 	if (put_user(0, &uattr->batch.count))
2065 		return -EFAULT;
2066 
2067 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2068 	if (!buf_prevkey)
2069 		return -ENOMEM;
2070 
2071 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2072 	if (!buf) {
2073 		kvfree(buf_prevkey);
2074 		return -ENOMEM;
2075 	}
2076 
2077 	err = -EFAULT;
2078 	prev_key = NULL;
2079 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2080 		goto free_buf;
2081 	key = buf;
2082 	value = key + map->key_size;
2083 	if (ubatch)
2084 		prev_key = buf_prevkey;
2085 
2086 	for (cp = 0; cp < max_count;) {
2087 		rcu_read_lock();
2088 		err = map->ops->map_get_next_key(map, prev_key, key);
2089 		rcu_read_unlock();
2090 		if (err)
2091 			break;
2092 		err = bpf_map_copy_value(map, key, value,
2093 					 attr->batch.elem_flags);
2094 
2095 		if (err == -ENOENT)
2096 			goto next_key;
2097 
2098 		if (err)
2099 			goto free_buf;
2100 
2101 		if (copy_to_user(keys + cp * map->key_size, key,
2102 				 map->key_size)) {
2103 			err = -EFAULT;
2104 			goto free_buf;
2105 		}
2106 		if (copy_to_user(values + cp * value_size, value, value_size)) {
2107 			err = -EFAULT;
2108 			goto free_buf;
2109 		}
2110 
2111 		cp++;
2112 next_key:
2113 		if (!prev_key)
2114 			prev_key = buf_prevkey;
2115 
2116 		swap(prev_key, key);
2117 		cond_resched();
2118 	}
2119 
2120 	if (err == -EFAULT)
2121 		goto free_buf;
2122 
2123 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2124 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2125 		err = -EFAULT;
2126 
2127 free_buf:
2128 	kvfree(buf_prevkey);
2129 	kvfree(buf);
2130 	return err;
2131 }
2132 
2133 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2134 
map_lookup_and_delete_elem(union bpf_attr * attr)2135 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2136 {
2137 	void __user *ukey = u64_to_user_ptr(attr->key);
2138 	void __user *uvalue = u64_to_user_ptr(attr->value);
2139 	struct bpf_map *map;
2140 	void *key, *value;
2141 	u32 value_size;
2142 	int err;
2143 
2144 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2145 		return -EINVAL;
2146 
2147 	if (attr->flags & ~BPF_F_LOCK)
2148 		return -EINVAL;
2149 
2150 	CLASS(fd, f)(attr->map_fd);
2151 	map = __bpf_map_get(f);
2152 	if (IS_ERR(map))
2153 		return PTR_ERR(map);
2154 	bpf_map_write_active_inc(map);
2155 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2156 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2157 		err = -EPERM;
2158 		goto err_put;
2159 	}
2160 
2161 	if (attr->flags &&
2162 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
2163 	     map->map_type == BPF_MAP_TYPE_STACK)) {
2164 		err = -EINVAL;
2165 		goto err_put;
2166 	}
2167 
2168 	if ((attr->flags & BPF_F_LOCK) &&
2169 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2170 		err = -EINVAL;
2171 		goto err_put;
2172 	}
2173 
2174 	key = __bpf_copy_key(ukey, map->key_size);
2175 	if (IS_ERR(key)) {
2176 		err = PTR_ERR(key);
2177 		goto err_put;
2178 	}
2179 
2180 	value_size = bpf_map_value_size(map, 0);
2181 
2182 	err = -ENOMEM;
2183 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2184 	if (!value)
2185 		goto free_key;
2186 
2187 	err = -ENOTSUPP;
2188 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2189 	    map->map_type == BPF_MAP_TYPE_STACK) {
2190 		err = map->ops->map_pop_elem(map, value);
2191 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
2192 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2193 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2194 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
2195 		   map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
2196 		if (!bpf_map_is_offloaded(map)) {
2197 			bpf_disable_instrumentation();
2198 			rcu_read_lock();
2199 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2200 			rcu_read_unlock();
2201 			bpf_enable_instrumentation();
2202 		}
2203 	}
2204 
2205 	if (err)
2206 		goto free_value;
2207 
2208 	if (copy_to_user(uvalue, value, value_size) != 0) {
2209 		err = -EFAULT;
2210 		goto free_value;
2211 	}
2212 
2213 	err = 0;
2214 
2215 free_value:
2216 	kvfree(value);
2217 free_key:
2218 	kvfree(key);
2219 err_put:
2220 	bpf_map_write_active_dec(map);
2221 	return err;
2222 }
2223 
2224 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2225 
map_freeze(const union bpf_attr * attr)2226 static int map_freeze(const union bpf_attr *attr)
2227 {
2228 	int err = 0;
2229 	struct bpf_map *map;
2230 
2231 	if (CHECK_ATTR(BPF_MAP_FREEZE))
2232 		return -EINVAL;
2233 
2234 	CLASS(fd, f)(attr->map_fd);
2235 	map = __bpf_map_get(f);
2236 	if (IS_ERR(map))
2237 		return PTR_ERR(map);
2238 
2239 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2240 		return -ENOTSUPP;
2241 
2242 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2243 		return -EPERM;
2244 
2245 	mutex_lock(&map->freeze_mutex);
2246 	if (bpf_map_write_active(map)) {
2247 		err = -EBUSY;
2248 		goto err_put;
2249 	}
2250 	if (READ_ONCE(map->frozen)) {
2251 		err = -EBUSY;
2252 		goto err_put;
2253 	}
2254 
2255 	WRITE_ONCE(map->frozen, true);
2256 err_put:
2257 	mutex_unlock(&map->freeze_mutex);
2258 	return err;
2259 }
2260 
2261 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2262 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2263 	[_id] = & _name ## _prog_ops,
2264 #define BPF_MAP_TYPE(_id, _ops)
2265 #define BPF_LINK_TYPE(_id, _name)
2266 #include <linux/bpf_types.h>
2267 #undef BPF_PROG_TYPE
2268 #undef BPF_MAP_TYPE
2269 #undef BPF_LINK_TYPE
2270 };
2271 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2272 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2273 {
2274 	const struct bpf_prog_ops *ops;
2275 
2276 	if (type >= ARRAY_SIZE(bpf_prog_types))
2277 		return -EINVAL;
2278 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2279 	ops = bpf_prog_types[type];
2280 	if (!ops)
2281 		return -EINVAL;
2282 
2283 	if (!bpf_prog_is_offloaded(prog->aux))
2284 		prog->aux->ops = ops;
2285 	else
2286 		prog->aux->ops = &bpf_offload_prog_ops;
2287 	prog->type = type;
2288 	return 0;
2289 }
2290 
2291 enum bpf_audit {
2292 	BPF_AUDIT_LOAD,
2293 	BPF_AUDIT_UNLOAD,
2294 	BPF_AUDIT_MAX,
2295 };
2296 
2297 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2298 	[BPF_AUDIT_LOAD]   = "LOAD",
2299 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
2300 };
2301 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2302 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2303 {
2304 	struct audit_context *ctx = NULL;
2305 	struct audit_buffer *ab;
2306 
2307 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2308 		return;
2309 	if (audit_enabled == AUDIT_OFF)
2310 		return;
2311 	if (!in_hardirq() && !irqs_disabled())
2312 		ctx = audit_context();
2313 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2314 	if (unlikely(!ab))
2315 		return;
2316 	audit_log_format(ab, "prog-id=%u op=%s",
2317 			 prog->aux->id, bpf_audit_str[op]);
2318 	audit_log_end(ab);
2319 }
2320 
bpf_prog_alloc_id(struct bpf_prog * prog)2321 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2322 {
2323 	int id;
2324 
2325 	idr_preload(GFP_KERNEL);
2326 	spin_lock_bh(&prog_idr_lock);
2327 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2328 	if (id > 0)
2329 		prog->aux->id = id;
2330 	spin_unlock_bh(&prog_idr_lock);
2331 	idr_preload_end();
2332 
2333 	/* id is in [1, INT_MAX) */
2334 	if (WARN_ON_ONCE(!id))
2335 		return -ENOSPC;
2336 
2337 	return id > 0 ? 0 : id;
2338 }
2339 
bpf_prog_free_id(struct bpf_prog * prog)2340 void bpf_prog_free_id(struct bpf_prog *prog)
2341 {
2342 	unsigned long flags;
2343 
2344 	/* cBPF to eBPF migrations are currently not in the idr store.
2345 	 * Offloaded programs are removed from the store when their device
2346 	 * disappears - even if someone grabs an fd to them they are unusable,
2347 	 * simply waiting for refcnt to drop to be freed.
2348 	 */
2349 	if (!prog->aux->id)
2350 		return;
2351 
2352 	spin_lock_irqsave(&prog_idr_lock, flags);
2353 	idr_remove(&prog_idr, prog->aux->id);
2354 	prog->aux->id = 0;
2355 	spin_unlock_irqrestore(&prog_idr_lock, flags);
2356 }
2357 
__bpf_prog_put_rcu(struct rcu_head * rcu)2358 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2359 {
2360 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2361 
2362 	kvfree(aux->func_info);
2363 	kfree(aux->func_info_aux);
2364 	free_uid(aux->user);
2365 	security_bpf_prog_free(aux->prog);
2366 	bpf_prog_free(aux->prog);
2367 }
2368 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2369 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2370 {
2371 	bpf_prog_kallsyms_del_all(prog);
2372 	btf_put(prog->aux->btf);
2373 	module_put(prog->aux->mod);
2374 	kvfree(prog->aux->jited_linfo);
2375 	kvfree(prog->aux->linfo);
2376 	kfree(prog->aux->kfunc_tab);
2377 	kfree(prog->aux->ctx_arg_info);
2378 	if (prog->aux->attach_btf)
2379 		btf_put(prog->aux->attach_btf);
2380 
2381 	if (deferred) {
2382 		if (prog->sleepable)
2383 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2384 		else
2385 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2386 	} else {
2387 		__bpf_prog_put_rcu(&prog->aux->rcu);
2388 	}
2389 }
2390 
bpf_prog_put_deferred(struct work_struct * work)2391 static void bpf_prog_put_deferred(struct work_struct *work)
2392 {
2393 	struct bpf_prog_aux *aux;
2394 	struct bpf_prog *prog;
2395 
2396 	aux = container_of(work, struct bpf_prog_aux, work);
2397 	prog = aux->prog;
2398 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2399 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2400 	bpf_prog_free_id(prog);
2401 	__bpf_prog_put_noref(prog, true);
2402 }
2403 
__bpf_prog_put(struct bpf_prog * prog)2404 static void __bpf_prog_put(struct bpf_prog *prog)
2405 {
2406 	struct bpf_prog_aux *aux = prog->aux;
2407 
2408 	if (atomic64_dec_and_test(&aux->refcnt)) {
2409 		if (in_hardirq() || irqs_disabled()) {
2410 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
2411 			schedule_work(&aux->work);
2412 		} else {
2413 			bpf_prog_put_deferred(&aux->work);
2414 		}
2415 	}
2416 }
2417 
bpf_prog_put(struct bpf_prog * prog)2418 void bpf_prog_put(struct bpf_prog *prog)
2419 {
2420 	__bpf_prog_put(prog);
2421 }
2422 EXPORT_SYMBOL_GPL(bpf_prog_put);
2423 
bpf_prog_release(struct inode * inode,struct file * filp)2424 static int bpf_prog_release(struct inode *inode, struct file *filp)
2425 {
2426 	struct bpf_prog *prog = filp->private_data;
2427 
2428 	bpf_prog_put(prog);
2429 	return 0;
2430 }
2431 
2432 struct bpf_prog_kstats {
2433 	u64 nsecs;
2434 	u64 cnt;
2435 	u64 misses;
2436 };
2437 
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2438 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2439 {
2440 	struct bpf_prog_stats *stats;
2441 	unsigned int flags;
2442 
2443 	if (unlikely(!prog->stats))
2444 		return;
2445 
2446 	stats = this_cpu_ptr(prog->stats);
2447 	flags = u64_stats_update_begin_irqsave(&stats->syncp);
2448 	u64_stats_inc(&stats->misses);
2449 	u64_stats_update_end_irqrestore(&stats->syncp, flags);
2450 }
2451 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2452 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2453 			       struct bpf_prog_kstats *stats)
2454 {
2455 	u64 nsecs = 0, cnt = 0, misses = 0;
2456 	int cpu;
2457 
2458 	for_each_possible_cpu(cpu) {
2459 		const struct bpf_prog_stats *st;
2460 		unsigned int start;
2461 		u64 tnsecs, tcnt, tmisses;
2462 
2463 		st = per_cpu_ptr(prog->stats, cpu);
2464 		do {
2465 			start = u64_stats_fetch_begin(&st->syncp);
2466 			tnsecs = u64_stats_read(&st->nsecs);
2467 			tcnt = u64_stats_read(&st->cnt);
2468 			tmisses = u64_stats_read(&st->misses);
2469 		} while (u64_stats_fetch_retry(&st->syncp, start));
2470 		nsecs += tnsecs;
2471 		cnt += tcnt;
2472 		misses += tmisses;
2473 	}
2474 	stats->nsecs = nsecs;
2475 	stats->cnt = cnt;
2476 	stats->misses = misses;
2477 }
2478 
2479 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2480 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2481 {
2482 	const struct bpf_prog *prog = filp->private_data;
2483 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2484 	struct bpf_prog_kstats stats;
2485 
2486 	bpf_prog_get_stats(prog, &stats);
2487 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2488 	seq_printf(m,
2489 		   "prog_type:\t%u\n"
2490 		   "prog_jited:\t%u\n"
2491 		   "prog_tag:\t%s\n"
2492 		   "memlock:\t%llu\n"
2493 		   "prog_id:\t%u\n"
2494 		   "run_time_ns:\t%llu\n"
2495 		   "run_cnt:\t%llu\n"
2496 		   "recursion_misses:\t%llu\n"
2497 		   "verified_insns:\t%u\n",
2498 		   prog->type,
2499 		   prog->jited,
2500 		   prog_tag,
2501 		   prog->pages * 1ULL << PAGE_SHIFT,
2502 		   prog->aux->id,
2503 		   stats.nsecs,
2504 		   stats.cnt,
2505 		   stats.misses,
2506 		   prog->aux->verified_insns);
2507 }
2508 #endif
2509 
2510 const struct file_operations bpf_prog_fops = {
2511 #ifdef CONFIG_PROC_FS
2512 	.show_fdinfo	= bpf_prog_show_fdinfo,
2513 #endif
2514 	.release	= bpf_prog_release,
2515 	.read		= bpf_dummy_read,
2516 	.write		= bpf_dummy_write,
2517 };
2518 
bpf_prog_new_fd(struct bpf_prog * prog)2519 int bpf_prog_new_fd(struct bpf_prog *prog)
2520 {
2521 	int ret;
2522 
2523 	ret = security_bpf_prog(prog);
2524 	if (ret < 0)
2525 		return ret;
2526 
2527 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2528 				O_RDWR | O_CLOEXEC);
2529 }
2530 
bpf_prog_add(struct bpf_prog * prog,int i)2531 void bpf_prog_add(struct bpf_prog *prog, int i)
2532 {
2533 	atomic64_add(i, &prog->aux->refcnt);
2534 }
2535 EXPORT_SYMBOL_GPL(bpf_prog_add);
2536 
bpf_prog_sub(struct bpf_prog * prog,int i)2537 void bpf_prog_sub(struct bpf_prog *prog, int i)
2538 {
2539 	/* Only to be used for undoing previous bpf_prog_add() in some
2540 	 * error path. We still know that another entity in our call
2541 	 * path holds a reference to the program, thus atomic_sub() can
2542 	 * be safely used in such cases!
2543 	 */
2544 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2545 }
2546 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2547 
bpf_prog_inc(struct bpf_prog * prog)2548 void bpf_prog_inc(struct bpf_prog *prog)
2549 {
2550 	atomic64_inc(&prog->aux->refcnt);
2551 }
2552 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2553 
2554 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2555 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2556 {
2557 	int refold;
2558 
2559 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2560 
2561 	if (!refold)
2562 		return ERR_PTR(-ENOENT);
2563 
2564 	return prog;
2565 }
2566 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2567 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2568 bool bpf_prog_get_ok(struct bpf_prog *prog,
2569 			    enum bpf_prog_type *attach_type, bool attach_drv)
2570 {
2571 	/* not an attachment, just a refcount inc, always allow */
2572 	if (!attach_type)
2573 		return true;
2574 
2575 	if (prog->type != *attach_type)
2576 		return false;
2577 	if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2578 		return false;
2579 
2580 	return true;
2581 }
2582 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2583 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2584 				       bool attach_drv)
2585 {
2586 	CLASS(fd, f)(ufd);
2587 	struct bpf_prog *prog;
2588 
2589 	if (fd_empty(f))
2590 		return ERR_PTR(-EBADF);
2591 	if (fd_file(f)->f_op != &bpf_prog_fops)
2592 		return ERR_PTR(-EINVAL);
2593 
2594 	prog = fd_file(f)->private_data;
2595 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2596 		return ERR_PTR(-EINVAL);
2597 
2598 	bpf_prog_inc(prog);
2599 	return prog;
2600 }
2601 
bpf_prog_get(u32 ufd)2602 struct bpf_prog *bpf_prog_get(u32 ufd)
2603 {
2604 	return __bpf_prog_get(ufd, NULL, false);
2605 }
2606 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2607 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2608 				       bool attach_drv)
2609 {
2610 	return __bpf_prog_get(ufd, &type, attach_drv);
2611 }
2612 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2613 
2614 /* Initially all BPF programs could be loaded w/o specifying
2615  * expected_attach_type. Later for some of them specifying expected_attach_type
2616  * at load time became required so that program could be validated properly.
2617  * Programs of types that are allowed to be loaded both w/ and w/o (for
2618  * backward compatibility) expected_attach_type, should have the default attach
2619  * type assigned to expected_attach_type for the latter case, so that it can be
2620  * validated later at attach time.
2621  *
2622  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2623  * prog type requires it but has some attach types that have to be backward
2624  * compatible.
2625  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2626 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2627 {
2628 	switch (attr->prog_type) {
2629 	case BPF_PROG_TYPE_CGROUP_SOCK:
2630 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2631 		 * exist so checking for non-zero is the way to go here.
2632 		 */
2633 		if (!attr->expected_attach_type)
2634 			attr->expected_attach_type =
2635 				BPF_CGROUP_INET_SOCK_CREATE;
2636 		break;
2637 	case BPF_PROG_TYPE_SK_REUSEPORT:
2638 		if (!attr->expected_attach_type)
2639 			attr->expected_attach_type =
2640 				BPF_SK_REUSEPORT_SELECT;
2641 		break;
2642 	}
2643 }
2644 
2645 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)2646 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2647 			   enum bpf_attach_type expected_attach_type,
2648 			   struct btf *attach_btf, u32 btf_id,
2649 			   struct bpf_prog *dst_prog)
2650 {
2651 	if (btf_id) {
2652 		if (btf_id > BTF_MAX_TYPE)
2653 			return -EINVAL;
2654 
2655 		if (!attach_btf && !dst_prog)
2656 			return -EINVAL;
2657 
2658 		switch (prog_type) {
2659 		case BPF_PROG_TYPE_TRACING:
2660 		case BPF_PROG_TYPE_LSM:
2661 		case BPF_PROG_TYPE_STRUCT_OPS:
2662 		case BPF_PROG_TYPE_EXT:
2663 			break;
2664 		default:
2665 			return -EINVAL;
2666 		}
2667 	}
2668 
2669 	if (attach_btf && (!btf_id || dst_prog))
2670 		return -EINVAL;
2671 
2672 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2673 	    prog_type != BPF_PROG_TYPE_EXT)
2674 		return -EINVAL;
2675 
2676 	switch (prog_type) {
2677 	case BPF_PROG_TYPE_CGROUP_SOCK:
2678 		switch (expected_attach_type) {
2679 		case BPF_CGROUP_INET_SOCK_CREATE:
2680 		case BPF_CGROUP_INET_SOCK_RELEASE:
2681 		case BPF_CGROUP_INET4_POST_BIND:
2682 		case BPF_CGROUP_INET6_POST_BIND:
2683 			return 0;
2684 		default:
2685 			return -EINVAL;
2686 		}
2687 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2688 		switch (expected_attach_type) {
2689 		case BPF_CGROUP_INET4_BIND:
2690 		case BPF_CGROUP_INET6_BIND:
2691 		case BPF_CGROUP_INET4_CONNECT:
2692 		case BPF_CGROUP_INET6_CONNECT:
2693 		case BPF_CGROUP_UNIX_CONNECT:
2694 		case BPF_CGROUP_INET4_GETPEERNAME:
2695 		case BPF_CGROUP_INET6_GETPEERNAME:
2696 		case BPF_CGROUP_UNIX_GETPEERNAME:
2697 		case BPF_CGROUP_INET4_GETSOCKNAME:
2698 		case BPF_CGROUP_INET6_GETSOCKNAME:
2699 		case BPF_CGROUP_UNIX_GETSOCKNAME:
2700 		case BPF_CGROUP_UDP4_SENDMSG:
2701 		case BPF_CGROUP_UDP6_SENDMSG:
2702 		case BPF_CGROUP_UNIX_SENDMSG:
2703 		case BPF_CGROUP_UDP4_RECVMSG:
2704 		case BPF_CGROUP_UDP6_RECVMSG:
2705 		case BPF_CGROUP_UNIX_RECVMSG:
2706 			return 0;
2707 		default:
2708 			return -EINVAL;
2709 		}
2710 	case BPF_PROG_TYPE_CGROUP_SKB:
2711 		switch (expected_attach_type) {
2712 		case BPF_CGROUP_INET_INGRESS:
2713 		case BPF_CGROUP_INET_EGRESS:
2714 			return 0;
2715 		default:
2716 			return -EINVAL;
2717 		}
2718 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2719 		switch (expected_attach_type) {
2720 		case BPF_CGROUP_SETSOCKOPT:
2721 		case BPF_CGROUP_GETSOCKOPT:
2722 			return 0;
2723 		default:
2724 			return -EINVAL;
2725 		}
2726 	case BPF_PROG_TYPE_SK_LOOKUP:
2727 		if (expected_attach_type == BPF_SK_LOOKUP)
2728 			return 0;
2729 		return -EINVAL;
2730 	case BPF_PROG_TYPE_SK_REUSEPORT:
2731 		switch (expected_attach_type) {
2732 		case BPF_SK_REUSEPORT_SELECT:
2733 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2734 			return 0;
2735 		default:
2736 			return -EINVAL;
2737 		}
2738 	case BPF_PROG_TYPE_NETFILTER:
2739 		if (expected_attach_type == BPF_NETFILTER)
2740 			return 0;
2741 		return -EINVAL;
2742 	case BPF_PROG_TYPE_SYSCALL:
2743 	case BPF_PROG_TYPE_EXT:
2744 		if (expected_attach_type)
2745 			return -EINVAL;
2746 		fallthrough;
2747 	default:
2748 		return 0;
2749 	}
2750 }
2751 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2752 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2753 {
2754 	switch (prog_type) {
2755 	case BPF_PROG_TYPE_SCHED_CLS:
2756 	case BPF_PROG_TYPE_SCHED_ACT:
2757 	case BPF_PROG_TYPE_XDP:
2758 	case BPF_PROG_TYPE_LWT_IN:
2759 	case BPF_PROG_TYPE_LWT_OUT:
2760 	case BPF_PROG_TYPE_LWT_XMIT:
2761 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2762 	case BPF_PROG_TYPE_SK_SKB:
2763 	case BPF_PROG_TYPE_SK_MSG:
2764 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2765 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2766 	case BPF_PROG_TYPE_CGROUP_SOCK:
2767 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2768 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2769 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2770 	case BPF_PROG_TYPE_SOCK_OPS:
2771 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2772 	case BPF_PROG_TYPE_NETFILTER:
2773 		return true;
2774 	case BPF_PROG_TYPE_CGROUP_SKB:
2775 		/* always unpriv */
2776 	case BPF_PROG_TYPE_SK_REUSEPORT:
2777 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2778 	default:
2779 		return false;
2780 	}
2781 }
2782 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2783 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2784 {
2785 	switch (prog_type) {
2786 	case BPF_PROG_TYPE_KPROBE:
2787 	case BPF_PROG_TYPE_TRACEPOINT:
2788 	case BPF_PROG_TYPE_PERF_EVENT:
2789 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2790 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2791 	case BPF_PROG_TYPE_TRACING:
2792 	case BPF_PROG_TYPE_LSM:
2793 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2794 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2795 		return true;
2796 	default:
2797 		return false;
2798 	}
2799 }
2800 
bpf_prog_verify_signature(struct bpf_prog * prog,union bpf_attr * attr,bool is_kernel)2801 static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr,
2802 				     bool is_kernel)
2803 {
2804 	bpfptr_t usig = make_bpfptr(attr->signature, is_kernel);
2805 	struct bpf_dynptr_kern sig_ptr, insns_ptr;
2806 	struct bpf_key *key = NULL;
2807 	void *sig;
2808 	int err = 0;
2809 
2810 	/*
2811 	 * Don't attempt to use kmalloc_large or vmalloc for signatures.
2812 	 * Practical signature for BPF program should be below this limit.
2813 	 */
2814 	if (attr->signature_size > KMALLOC_MAX_CACHE_SIZE)
2815 		return -EINVAL;
2816 
2817 	if (system_keyring_id_check(attr->keyring_id) == 0)
2818 		key = bpf_lookup_system_key(attr->keyring_id);
2819 	else
2820 		key = bpf_lookup_user_key(attr->keyring_id, 0);
2821 
2822 	if (!key)
2823 		return -EINVAL;
2824 
2825 	sig = kvmemdup_bpfptr(usig, attr->signature_size);
2826 	if (IS_ERR(sig)) {
2827 		bpf_key_put(key);
2828 		return PTR_ERR(sig);
2829 	}
2830 
2831 	bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0,
2832 			attr->signature_size);
2833 	bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0,
2834 			prog->len * sizeof(struct bpf_insn));
2835 
2836 	err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr,
2837 					 (struct bpf_dynptr *)&sig_ptr, key);
2838 
2839 	bpf_key_put(key);
2840 	kvfree(sig);
2841 	return err;
2842 }
2843 
bpf_prog_mark_insn_arrays_ready(struct bpf_prog * prog)2844 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog)
2845 {
2846 	int err;
2847 	int i;
2848 
2849 	for (i = 0; i < prog->aux->used_map_cnt; i++) {
2850 		if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY)
2851 			continue;
2852 
2853 		err = bpf_insn_array_ready(prog->aux->used_maps[i]);
2854 		if (err)
2855 			return err;
2856 	}
2857 
2858 	return 0;
2859 }
2860 
2861 /* last field in 'union bpf_attr' used by this command */
2862 #define BPF_PROG_LOAD_LAST_FIELD keyring_id
2863 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2864 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2865 {
2866 	enum bpf_prog_type type = attr->prog_type;
2867 	struct bpf_prog *prog, *dst_prog = NULL;
2868 	struct btf *attach_btf = NULL;
2869 	struct bpf_token *token = NULL;
2870 	bool bpf_cap;
2871 	int err;
2872 	char license[128];
2873 
2874 	if (CHECK_ATTR(BPF_PROG_LOAD))
2875 		return -EINVAL;
2876 
2877 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2878 				 BPF_F_ANY_ALIGNMENT |
2879 				 BPF_F_TEST_STATE_FREQ |
2880 				 BPF_F_SLEEPABLE |
2881 				 BPF_F_TEST_RND_HI32 |
2882 				 BPF_F_XDP_HAS_FRAGS |
2883 				 BPF_F_XDP_DEV_BOUND_ONLY |
2884 				 BPF_F_TEST_REG_INVARIANTS |
2885 				 BPF_F_TOKEN_FD))
2886 		return -EINVAL;
2887 
2888 	bpf_prog_load_fixup_attach_type(attr);
2889 
2890 	if (attr->prog_flags & BPF_F_TOKEN_FD) {
2891 		token = bpf_token_get_from_fd(attr->prog_token_fd);
2892 		if (IS_ERR(token))
2893 			return PTR_ERR(token);
2894 		/* if current token doesn't grant prog loading permissions,
2895 		 * then we can't use this token, so ignore it and rely on
2896 		 * system-wide capabilities checks
2897 		 */
2898 		if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2899 		    !bpf_token_allow_prog_type(token, attr->prog_type,
2900 					       attr->expected_attach_type)) {
2901 			bpf_token_put(token);
2902 			token = NULL;
2903 		}
2904 	}
2905 
2906 	bpf_cap = bpf_token_capable(token, CAP_BPF);
2907 	err = -EPERM;
2908 
2909 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2910 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2911 	    !bpf_cap)
2912 		goto put_token;
2913 
2914 	/* Intent here is for unprivileged_bpf_disabled to block BPF program
2915 	 * creation for unprivileged users; other actions depend
2916 	 * on fd availability and access to bpffs, so are dependent on
2917 	 * object creation success. Even with unprivileged BPF disabled,
2918 	 * capability checks are still carried out for these
2919 	 * and other operations.
2920 	 */
2921 	if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2922 		goto put_token;
2923 
2924 	if (attr->insn_cnt == 0 ||
2925 	    attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2926 		err = -E2BIG;
2927 		goto put_token;
2928 	}
2929 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2930 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2931 	    !bpf_cap)
2932 		goto put_token;
2933 
2934 	if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2935 		goto put_token;
2936 	if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2937 		goto put_token;
2938 
2939 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2940 	 * or btf, we need to check which one it is
2941 	 */
2942 	if (attr->attach_prog_fd) {
2943 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2944 		if (IS_ERR(dst_prog)) {
2945 			dst_prog = NULL;
2946 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2947 			if (IS_ERR(attach_btf)) {
2948 				err = -EINVAL;
2949 				goto put_token;
2950 			}
2951 			if (!btf_is_kernel(attach_btf)) {
2952 				/* attaching through specifying bpf_prog's BTF
2953 				 * objects directly might be supported eventually
2954 				 */
2955 				btf_put(attach_btf);
2956 				err = -ENOTSUPP;
2957 				goto put_token;
2958 			}
2959 		}
2960 	} else if (attr->attach_btf_id) {
2961 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2962 		attach_btf = bpf_get_btf_vmlinux();
2963 		if (IS_ERR(attach_btf)) {
2964 			err = PTR_ERR(attach_btf);
2965 			goto put_token;
2966 		}
2967 		if (!attach_btf) {
2968 			err = -EINVAL;
2969 			goto put_token;
2970 		}
2971 		btf_get(attach_btf);
2972 	}
2973 
2974 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2975 				       attach_btf, attr->attach_btf_id,
2976 				       dst_prog)) {
2977 		if (dst_prog)
2978 			bpf_prog_put(dst_prog);
2979 		if (attach_btf)
2980 			btf_put(attach_btf);
2981 		err = -EINVAL;
2982 		goto put_token;
2983 	}
2984 
2985 	/* plain bpf_prog allocation */
2986 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2987 	if (!prog) {
2988 		if (dst_prog)
2989 			bpf_prog_put(dst_prog);
2990 		if (attach_btf)
2991 			btf_put(attach_btf);
2992 		err = -EINVAL;
2993 		goto put_token;
2994 	}
2995 
2996 	prog->expected_attach_type = attr->expected_attach_type;
2997 	prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
2998 	prog->aux->attach_btf = attach_btf;
2999 	prog->aux->attach_btf_id = attr->attach_btf_id;
3000 	prog->aux->dst_prog = dst_prog;
3001 	prog->aux->dev_bound = !!attr->prog_ifindex;
3002 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
3003 
3004 	/* move token into prog->aux, reuse taken refcnt */
3005 	prog->aux->token = token;
3006 	token = NULL;
3007 
3008 	prog->aux->user = get_current_user();
3009 	prog->len = attr->insn_cnt;
3010 
3011 	err = -EFAULT;
3012 	if (copy_from_bpfptr(prog->insns,
3013 			     make_bpfptr(attr->insns, uattr.is_kernel),
3014 			     bpf_prog_insn_size(prog)) != 0)
3015 		goto free_prog;
3016 	/* copy eBPF program license from user space */
3017 	if (strncpy_from_bpfptr(license,
3018 				make_bpfptr(attr->license, uattr.is_kernel),
3019 				sizeof(license) - 1) < 0)
3020 		goto free_prog;
3021 	license[sizeof(license) - 1] = 0;
3022 
3023 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
3024 	prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
3025 
3026 	if (attr->signature) {
3027 		err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel);
3028 		if (err)
3029 			goto free_prog;
3030 	}
3031 
3032 	prog->orig_prog = NULL;
3033 	prog->jited = 0;
3034 
3035 	atomic64_set(&prog->aux->refcnt, 1);
3036 
3037 	if (bpf_prog_is_dev_bound(prog->aux)) {
3038 		err = bpf_prog_dev_bound_init(prog, attr);
3039 		if (err)
3040 			goto free_prog;
3041 	}
3042 
3043 	if (type == BPF_PROG_TYPE_EXT && dst_prog &&
3044 	    bpf_prog_is_dev_bound(dst_prog->aux)) {
3045 		err = bpf_prog_dev_bound_inherit(prog, dst_prog);
3046 		if (err)
3047 			goto free_prog;
3048 	}
3049 
3050 	/*
3051 	 * Bookkeeping for managing the program attachment chain.
3052 	 *
3053 	 * It might be tempting to set attach_tracing_prog flag at the attachment
3054 	 * time, but this will not prevent from loading bunch of tracing prog
3055 	 * first, then attach them one to another.
3056 	 *
3057 	 * The flag attach_tracing_prog is set for the whole program lifecycle, and
3058 	 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
3059 	 * programs cannot change attachment target.
3060 	 */
3061 	if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
3062 	    dst_prog->type == BPF_PROG_TYPE_TRACING) {
3063 		prog->aux->attach_tracing_prog = true;
3064 	}
3065 
3066 	/* find program type: socket_filter vs tracing_filter */
3067 	err = find_prog_type(type, prog);
3068 	if (err < 0)
3069 		goto free_prog;
3070 
3071 	prog->aux->load_time = ktime_get_boottime_ns();
3072 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
3073 			       sizeof(attr->prog_name));
3074 	if (err < 0)
3075 		goto free_prog;
3076 
3077 	err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel);
3078 	if (err)
3079 		goto free_prog_sec;
3080 
3081 	/* run eBPF verifier */
3082 	err = bpf_check(&prog, attr, uattr, uattr_size);
3083 	if (err < 0)
3084 		goto free_used_maps;
3085 
3086 	prog = bpf_prog_select_runtime(prog, &err);
3087 	if (err < 0)
3088 		goto free_used_maps;
3089 
3090 	err = bpf_prog_mark_insn_arrays_ready(prog);
3091 	if (err < 0)
3092 		goto free_used_maps;
3093 
3094 	err = bpf_prog_alloc_id(prog);
3095 	if (err)
3096 		goto free_used_maps;
3097 
3098 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
3099 	 * effectively publicly exposed. However, retrieving via
3100 	 * bpf_prog_get_fd_by_id() will take another reference,
3101 	 * therefore it cannot be gone underneath us.
3102 	 *
3103 	 * Only for the time /after/ successful bpf_prog_new_fd()
3104 	 * and before returning to userspace, we might just hold
3105 	 * one reference and any parallel close on that fd could
3106 	 * rip everything out. Hence, below notifications must
3107 	 * happen before bpf_prog_new_fd().
3108 	 *
3109 	 * Also, any failure handling from this point onwards must
3110 	 * be using bpf_prog_put() given the program is exposed.
3111 	 */
3112 	bpf_prog_kallsyms_add(prog);
3113 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
3114 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3115 
3116 	err = bpf_prog_new_fd(prog);
3117 	if (err < 0)
3118 		bpf_prog_put(prog);
3119 	return err;
3120 
3121 free_used_maps:
3122 	/* In case we have subprogs, we need to wait for a grace
3123 	 * period before we can tear down JIT memory since symbols
3124 	 * are already exposed under kallsyms.
3125 	 */
3126 	__bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3127 	return err;
3128 
3129 free_prog_sec:
3130 	security_bpf_prog_free(prog);
3131 free_prog:
3132 	free_uid(prog->aux->user);
3133 	if (prog->aux->attach_btf)
3134 		btf_put(prog->aux->attach_btf);
3135 	bpf_prog_free(prog);
3136 put_token:
3137 	bpf_token_put(token);
3138 	return err;
3139 }
3140 
3141 #define BPF_OBJ_LAST_FIELD path_fd
3142 
bpf_obj_pin(const union bpf_attr * attr)3143 static int bpf_obj_pin(const union bpf_attr *attr)
3144 {
3145 	int path_fd;
3146 
3147 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3148 		return -EINVAL;
3149 
3150 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3151 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3152 		return -EINVAL;
3153 
3154 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3155 	return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3156 				u64_to_user_ptr(attr->pathname));
3157 }
3158 
bpf_obj_get(const union bpf_attr * attr)3159 static int bpf_obj_get(const union bpf_attr *attr)
3160 {
3161 	int path_fd;
3162 
3163 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3164 	    attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3165 		return -EINVAL;
3166 
3167 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3168 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3169 		return -EINVAL;
3170 
3171 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3172 	return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3173 				attr->file_flags);
3174 }
3175 
3176 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3177  * "sleepable" semantics, which normally would mean that BPF link's attach
3178  * hook can dereference link or link's underlying program for some time after
3179  * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3180  * BPF program itself can be non-sleepable, yet, because it's transitively
3181  * reachable through BPF link, its freeing has to be delayed until after RCU
3182  * Tasks Trace GP.
3183  */
bpf_link_init_sleepable(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type,bool sleepable)3184 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3185 			     const struct bpf_link_ops *ops, struct bpf_prog *prog,
3186 			     enum bpf_attach_type attach_type, bool sleepable)
3187 {
3188 	WARN_ON(ops->dealloc && ops->dealloc_deferred);
3189 	atomic64_set(&link->refcnt, 1);
3190 	link->type = type;
3191 	link->sleepable = sleepable;
3192 	link->id = 0;
3193 	link->ops = ops;
3194 	link->prog = prog;
3195 	link->attach_type = attach_type;
3196 }
3197 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type)3198 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3199 		   const struct bpf_link_ops *ops, struct bpf_prog *prog,
3200 		   enum bpf_attach_type attach_type)
3201 {
3202 	bpf_link_init_sleepable(link, type, ops, prog, attach_type, false);
3203 }
3204 
bpf_link_free_id(int id)3205 static void bpf_link_free_id(int id)
3206 {
3207 	if (!id)
3208 		return;
3209 
3210 	spin_lock_bh(&link_idr_lock);
3211 	idr_remove(&link_idr, id);
3212 	spin_unlock_bh(&link_idr_lock);
3213 }
3214 
3215 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3216  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3217  * anon_inode's release() call. This helper marks bpf_link as
3218  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3219  * is not decremented, it's the responsibility of a calling code that failed
3220  * to complete bpf_link initialization.
3221  * This helper eventually calls link's dealloc callback, but does not call
3222  * link's release callback.
3223  */
bpf_link_cleanup(struct bpf_link_primer * primer)3224 void bpf_link_cleanup(struct bpf_link_primer *primer)
3225 {
3226 	primer->link->prog = NULL;
3227 	bpf_link_free_id(primer->id);
3228 	fput(primer->file);
3229 	put_unused_fd(primer->fd);
3230 }
3231 
bpf_link_inc(struct bpf_link * link)3232 void bpf_link_inc(struct bpf_link *link)
3233 {
3234 	atomic64_inc(&link->refcnt);
3235 }
3236 
bpf_link_dealloc(struct bpf_link * link)3237 static void bpf_link_dealloc(struct bpf_link *link)
3238 {
3239 	/* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3240 	if (link->prog)
3241 		bpf_prog_put(link->prog);
3242 
3243 	/* free bpf_link and its containing memory */
3244 	if (link->ops->dealloc_deferred)
3245 		link->ops->dealloc_deferred(link);
3246 	else
3247 		link->ops->dealloc(link);
3248 }
3249 
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3250 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3251 {
3252 	struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3253 
3254 	bpf_link_dealloc(link);
3255 }
3256 
bpf_link_is_tracepoint(struct bpf_link * link)3257 static bool bpf_link_is_tracepoint(struct bpf_link *link)
3258 {
3259 	/*
3260 	 * Only these combinations support a tracepoint bpf_link.
3261 	 * BPF_LINK_TYPE_TRACING raw_tp progs are hardcoded to use
3262 	 * bpf_raw_tp_link_lops and thus dealloc_deferred(), see
3263 	 * bpf_raw_tp_link_attach().
3264 	 */
3265 	return link->type == BPF_LINK_TYPE_RAW_TRACEPOINT ||
3266 	       (link->type == BPF_LINK_TYPE_TRACING && link->attach_type == BPF_TRACE_RAW_TP);
3267 }
3268 
3269 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3270 static void bpf_link_free(struct bpf_link *link)
3271 {
3272 	const struct bpf_link_ops *ops = link->ops;
3273 
3274 	bpf_link_free_id(link->id);
3275 	/* detach BPF program, clean up used resources */
3276 	if (link->prog)
3277 		ops->release(link);
3278 	if (ops->dealloc_deferred) {
3279 		/*
3280 		 * Schedule BPF link deallocation, which will only then
3281 		 * trigger putting BPF program refcount.
3282 		 * If underlying BPF program is sleepable or BPF link's target
3283 		 * attach hookpoint is sleepable or otherwise requires RCU GPs
3284 		 * to ensure link and its underlying BPF program is not
3285 		 * reachable anymore, we need to first wait for RCU tasks
3286 		 * trace sync, and then go through "classic" RCU grace period.
3287 		 *
3288 		 * For tracepoint BPF links, we need to go through SRCU grace
3289 		 * period wait instead when non-faultable tracepoint is used. We
3290 		 * don't need to chain SRCU grace period waits, however, for the
3291 		 * faultable case, since it exclusively uses RCU Tasks Trace.
3292 		 */
3293 		if (link->sleepable || (link->prog && link->prog->sleepable))
3294 			/* RCU Tasks Trace grace period implies RCU grace period. */
3295 			call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3296 		/* We need to do a SRCU grace period wait for non-faultable tracepoint BPF links. */
3297 		else if (bpf_link_is_tracepoint(link))
3298 			call_tracepoint_unregister_atomic(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3299 		else
3300 			call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3301 	} else if (ops->dealloc) {
3302 		bpf_link_dealloc(link);
3303 	}
3304 }
3305 
bpf_link_put_deferred(struct work_struct * work)3306 static void bpf_link_put_deferred(struct work_struct *work)
3307 {
3308 	struct bpf_link *link = container_of(work, struct bpf_link, work);
3309 
3310 	bpf_link_free(link);
3311 }
3312 
3313 /* bpf_link_put might be called from atomic context. It needs to be called
3314  * from sleepable context in order to acquire sleeping locks during the process.
3315  */
bpf_link_put(struct bpf_link * link)3316 void bpf_link_put(struct bpf_link *link)
3317 {
3318 	if (!atomic64_dec_and_test(&link->refcnt))
3319 		return;
3320 
3321 	INIT_WORK(&link->work, bpf_link_put_deferred);
3322 	schedule_work(&link->work);
3323 }
3324 EXPORT_SYMBOL(bpf_link_put);
3325 
bpf_link_put_direct(struct bpf_link * link)3326 static void bpf_link_put_direct(struct bpf_link *link)
3327 {
3328 	if (!atomic64_dec_and_test(&link->refcnt))
3329 		return;
3330 	bpf_link_free(link);
3331 }
3332 
bpf_link_release(struct inode * inode,struct file * filp)3333 static int bpf_link_release(struct inode *inode, struct file *filp)
3334 {
3335 	struct bpf_link *link = filp->private_data;
3336 
3337 	bpf_link_put_direct(link);
3338 	return 0;
3339 }
3340 
3341 #ifdef CONFIG_PROC_FS
3342 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3343 #define BPF_MAP_TYPE(_id, _ops)
3344 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3345 static const char *bpf_link_type_strs[] = {
3346 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3347 #include <linux/bpf_types.h>
3348 };
3349 #undef BPF_PROG_TYPE
3350 #undef BPF_MAP_TYPE
3351 #undef BPF_LINK_TYPE
3352 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3353 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3354 {
3355 	const struct bpf_link *link = filp->private_data;
3356 	const struct bpf_prog *prog = link->prog;
3357 	enum bpf_link_type type = link->type;
3358 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3359 
3360 	if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3361 		if (link->type == BPF_LINK_TYPE_KPROBE_MULTI)
3362 			seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ?
3363 				   "kretprobe_multi" : "kprobe_multi");
3364 		else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI)
3365 			seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ?
3366 				   "uretprobe_multi" : "uprobe_multi");
3367 		else
3368 			seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3369 	} else {
3370 		WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3371 		seq_printf(m, "link_type:\t<%u>\n", type);
3372 	}
3373 	seq_printf(m, "link_id:\t%u\n", link->id);
3374 
3375 	if (prog) {
3376 		bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3377 		seq_printf(m,
3378 			   "prog_tag:\t%s\n"
3379 			   "prog_id:\t%u\n",
3380 			   prog_tag,
3381 			   prog->aux->id);
3382 	}
3383 	if (link->ops->show_fdinfo)
3384 		link->ops->show_fdinfo(link, m);
3385 }
3386 #endif
3387 
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3388 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3389 {
3390 	struct bpf_link *link = file->private_data;
3391 
3392 	return link->ops->poll(file, pts);
3393 }
3394 
3395 static const struct file_operations bpf_link_fops = {
3396 #ifdef CONFIG_PROC_FS
3397 	.show_fdinfo	= bpf_link_show_fdinfo,
3398 #endif
3399 	.release	= bpf_link_release,
3400 	.read		= bpf_dummy_read,
3401 	.write		= bpf_dummy_write,
3402 };
3403 
3404 static const struct file_operations bpf_link_fops_poll = {
3405 #ifdef CONFIG_PROC_FS
3406 	.show_fdinfo	= bpf_link_show_fdinfo,
3407 #endif
3408 	.release	= bpf_link_release,
3409 	.read		= bpf_dummy_read,
3410 	.write		= bpf_dummy_write,
3411 	.poll		= bpf_link_poll,
3412 };
3413 
bpf_link_alloc_id(struct bpf_link * link)3414 static int bpf_link_alloc_id(struct bpf_link *link)
3415 {
3416 	int id;
3417 
3418 	idr_preload(GFP_KERNEL);
3419 	spin_lock_bh(&link_idr_lock);
3420 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3421 	spin_unlock_bh(&link_idr_lock);
3422 	idr_preload_end();
3423 
3424 	return id;
3425 }
3426 
3427 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3428  * reserving unused FD and allocating ID from link_idr. This is to be paired
3429  * with bpf_link_settle() to install FD and ID and expose bpf_link to
3430  * user-space, if bpf_link is successfully attached. If not, bpf_link and
3431  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3432  * transient state is passed around in struct bpf_link_primer.
3433  * This is preferred way to create and initialize bpf_link, especially when
3434  * there are complicated and expensive operations in between creating bpf_link
3435  * itself and attaching it to BPF hook. By using bpf_link_prime() and
3436  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3437  * expensive (and potentially failing) roll back operations in a rare case
3438  * that file, FD, or ID can't be allocated.
3439  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3440 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3441 {
3442 	struct file *file;
3443 	int fd, id;
3444 
3445 	fd = get_unused_fd_flags(O_CLOEXEC);
3446 	if (fd < 0)
3447 		return fd;
3448 
3449 
3450 	id = bpf_link_alloc_id(link);
3451 	if (id < 0) {
3452 		put_unused_fd(fd);
3453 		return id;
3454 	}
3455 
3456 	file = anon_inode_getfile("bpf_link",
3457 				  link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3458 				  link, O_CLOEXEC);
3459 	if (IS_ERR(file)) {
3460 		bpf_link_free_id(id);
3461 		put_unused_fd(fd);
3462 		return PTR_ERR(file);
3463 	}
3464 
3465 	primer->link = link;
3466 	primer->file = file;
3467 	primer->fd = fd;
3468 	primer->id = id;
3469 	return 0;
3470 }
3471 
bpf_link_settle(struct bpf_link_primer * primer)3472 int bpf_link_settle(struct bpf_link_primer *primer)
3473 {
3474 	/* make bpf_link fetchable by ID */
3475 	spin_lock_bh(&link_idr_lock);
3476 	primer->link->id = primer->id;
3477 	spin_unlock_bh(&link_idr_lock);
3478 	/* make bpf_link fetchable by FD */
3479 	fd_install(primer->fd, primer->file);
3480 	/* pass through installed FD */
3481 	return primer->fd;
3482 }
3483 
bpf_link_new_fd(struct bpf_link * link)3484 int bpf_link_new_fd(struct bpf_link *link)
3485 {
3486 	return anon_inode_getfd("bpf-link",
3487 				link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3488 				link, O_CLOEXEC);
3489 }
3490 
bpf_link_get_from_fd(u32 ufd)3491 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3492 {
3493 	CLASS(fd, f)(ufd);
3494 	struct bpf_link *link;
3495 
3496 	if (fd_empty(f))
3497 		return ERR_PTR(-EBADF);
3498 	if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3499 		return ERR_PTR(-EINVAL);
3500 
3501 	link = fd_file(f)->private_data;
3502 	bpf_link_inc(link);
3503 	return link;
3504 }
3505 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL");
3506 
bpf_tracing_link_release(struct bpf_link * link)3507 static void bpf_tracing_link_release(struct bpf_link *link)
3508 {
3509 	struct bpf_tracing_link *tr_link =
3510 		container_of(link, struct bpf_tracing_link, link.link);
3511 
3512 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3513 						tr_link->trampoline,
3514 						tr_link->tgt_prog));
3515 
3516 	bpf_trampoline_put(tr_link->trampoline);
3517 
3518 	/* tgt_prog is NULL if target is a kernel function */
3519 	if (tr_link->tgt_prog)
3520 		bpf_prog_put(tr_link->tgt_prog);
3521 }
3522 
bpf_tracing_link_dealloc(struct bpf_link * link)3523 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3524 {
3525 	struct bpf_tracing_link *tr_link =
3526 		container_of(link, struct bpf_tracing_link, link.link);
3527 
3528 	kfree(tr_link);
3529 }
3530 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3531 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3532 					 struct seq_file *seq)
3533 {
3534 	struct bpf_tracing_link *tr_link =
3535 		container_of(link, struct bpf_tracing_link, link.link);
3536 	u32 target_btf_id, target_obj_id;
3537 
3538 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3539 				  &target_obj_id, &target_btf_id);
3540 	seq_printf(seq,
3541 		   "attach_type:\t%d\n"
3542 		   "target_obj_id:\t%u\n"
3543 		   "target_btf_id:\t%u\n"
3544 		   "cookie:\t%llu\n",
3545 		   link->attach_type,
3546 		   target_obj_id,
3547 		   target_btf_id,
3548 		   tr_link->link.cookie);
3549 }
3550 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3551 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3552 					   struct bpf_link_info *info)
3553 {
3554 	struct bpf_tracing_link *tr_link =
3555 		container_of(link, struct bpf_tracing_link, link.link);
3556 
3557 	info->tracing.attach_type = link->attach_type;
3558 	info->tracing.cookie = tr_link->link.cookie;
3559 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3560 				  &info->tracing.target_obj_id,
3561 				  &info->tracing.target_btf_id);
3562 
3563 	return 0;
3564 }
3565 
3566 static const struct bpf_link_ops bpf_tracing_link_lops = {
3567 	.release = bpf_tracing_link_release,
3568 	.dealloc = bpf_tracing_link_dealloc,
3569 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3570 	.fill_link_info = bpf_tracing_link_fill_link_info,
3571 };
3572 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie,enum bpf_attach_type attach_type)3573 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3574 				   int tgt_prog_fd,
3575 				   u32 btf_id,
3576 				   u64 bpf_cookie,
3577 				   enum bpf_attach_type attach_type)
3578 {
3579 	struct bpf_link_primer link_primer;
3580 	struct bpf_prog *tgt_prog = NULL;
3581 	struct bpf_trampoline *tr = NULL;
3582 	struct bpf_tracing_link *link;
3583 	u64 key = 0;
3584 	int err;
3585 
3586 	switch (prog->type) {
3587 	case BPF_PROG_TYPE_TRACING:
3588 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3589 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3590 		    prog->expected_attach_type != BPF_TRACE_FSESSION &&
3591 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3592 			err = -EINVAL;
3593 			goto out_put_prog;
3594 		}
3595 		break;
3596 	case BPF_PROG_TYPE_EXT:
3597 		if (prog->expected_attach_type != 0) {
3598 			err = -EINVAL;
3599 			goto out_put_prog;
3600 		}
3601 		break;
3602 	case BPF_PROG_TYPE_LSM:
3603 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3604 			err = -EINVAL;
3605 			goto out_put_prog;
3606 		}
3607 		break;
3608 	default:
3609 		err = -EINVAL;
3610 		goto out_put_prog;
3611 	}
3612 
3613 	if (!!tgt_prog_fd != !!btf_id) {
3614 		err = -EINVAL;
3615 		goto out_put_prog;
3616 	}
3617 
3618 	if (tgt_prog_fd) {
3619 		/*
3620 		 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3621 		 * part would be changed to implement the same for
3622 		 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3623 		 * attach_tracing_prog flag is set.
3624 		 */
3625 		if (prog->type != BPF_PROG_TYPE_EXT) {
3626 			err = -EINVAL;
3627 			goto out_put_prog;
3628 		}
3629 
3630 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3631 		if (IS_ERR(tgt_prog)) {
3632 			err = PTR_ERR(tgt_prog);
3633 			tgt_prog = NULL;
3634 			goto out_put_prog;
3635 		}
3636 
3637 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3638 	}
3639 
3640 	if (prog->expected_attach_type == BPF_TRACE_FSESSION) {
3641 		struct bpf_fsession_link *fslink;
3642 
3643 		fslink = kzalloc_obj(*fslink, GFP_USER);
3644 		if (fslink) {
3645 			bpf_link_init(&fslink->fexit.link, BPF_LINK_TYPE_TRACING,
3646 				      &bpf_tracing_link_lops, prog, attach_type);
3647 			fslink->fexit.cookie = bpf_cookie;
3648 			link = &fslink->link;
3649 		} else {
3650 			link = NULL;
3651 		}
3652 	} else {
3653 		link = kzalloc_obj(*link, GFP_USER);
3654 	}
3655 	if (!link) {
3656 		err = -ENOMEM;
3657 		goto out_put_prog;
3658 	}
3659 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3660 		      &bpf_tracing_link_lops, prog, attach_type);
3661 
3662 	link->link.cookie = bpf_cookie;
3663 
3664 	mutex_lock(&prog->aux->dst_mutex);
3665 
3666 	/* There are a few possible cases here:
3667 	 *
3668 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3669 	 *   and not yet attached to anything, so we can use the values stored
3670 	 *   in prog->aux
3671 	 *
3672 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3673 	 *   attached to a target and its initial target was cleared (below)
3674 	 *
3675 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3676 	 *   target_btf_id using the link_create API.
3677 	 *
3678 	 * - if tgt_prog == NULL when this function was called using the old
3679 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3680 	 *
3681 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3682 	 *   was detached and is going for re-attachment.
3683 	 *
3684 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3685 	 *   are NULL, then program was already attached and user did not provide
3686 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3687 	 */
3688 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3689 		/*
3690 		 * Allow re-attach for TRACING and LSM programs. If it's
3691 		 * currently linked, bpf_trampoline_link_prog will fail.
3692 		 * EXT programs need to specify tgt_prog_fd, so they
3693 		 * re-attach in separate code path.
3694 		 */
3695 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3696 		    prog->type != BPF_PROG_TYPE_LSM) {
3697 			err = -EINVAL;
3698 			goto out_unlock;
3699 		}
3700 		/* We can allow re-attach only if we have valid attach_btf. */
3701 		if (!prog->aux->attach_btf) {
3702 			err = -EINVAL;
3703 			goto out_unlock;
3704 		}
3705 		btf_id = prog->aux->attach_btf_id;
3706 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3707 	}
3708 
3709 	if (!prog->aux->dst_trampoline ||
3710 	    (key && key != prog->aux->dst_trampoline->key)) {
3711 		/* If there is no saved target, or the specified target is
3712 		 * different from the destination specified at load time, we
3713 		 * need a new trampoline and a check for compatibility
3714 		 */
3715 		struct bpf_attach_target_info tgt_info = {};
3716 
3717 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3718 					      &tgt_info);
3719 		if (err)
3720 			goto out_unlock;
3721 
3722 		if (tgt_info.tgt_mod) {
3723 			module_put(prog->aux->mod);
3724 			prog->aux->mod = tgt_info.tgt_mod;
3725 		}
3726 
3727 		tr = bpf_trampoline_get(key, &tgt_info);
3728 		if (!tr) {
3729 			err = -ENOMEM;
3730 			goto out_unlock;
3731 		}
3732 	} else {
3733 		/* The caller didn't specify a target, or the target was the
3734 		 * same as the destination supplied during program load. This
3735 		 * means we can reuse the trampoline and reference from program
3736 		 * load time, and there is no need to allocate a new one. This
3737 		 * can only happen once for any program, as the saved values in
3738 		 * prog->aux are cleared below.
3739 		 */
3740 		tr = prog->aux->dst_trampoline;
3741 		tgt_prog = prog->aux->dst_prog;
3742 	}
3743 	/*
3744 	 * It is to prevent modifying struct pt_regs via kprobe_write_ctx=true
3745 	 * freplace prog. Without this check, kprobe_write_ctx=true freplace
3746 	 * prog is allowed to attach to kprobe_write_ctx=false kprobe prog, and
3747 	 * then modify the registers of the kprobe prog's target kernel
3748 	 * function.
3749 	 *
3750 	 * This also blocks the combination of uprobe+freplace, because it is
3751 	 * unable to recognize the use of the tgt_prog as an uprobe or a kprobe
3752 	 * by tgt_prog itself. At attach time, uprobe/kprobe is recognized by
3753 	 * the target perf event flags in __perf_event_set_bpf_prog().
3754 	 */
3755 	if (prog->type == BPF_PROG_TYPE_EXT &&
3756 	    prog->aux->kprobe_write_ctx != tgt_prog->aux->kprobe_write_ctx) {
3757 		err = -EINVAL;
3758 		goto out_unlock;
3759 	}
3760 
3761 	err = bpf_link_prime(&link->link.link, &link_primer);
3762 	if (err)
3763 		goto out_unlock;
3764 
3765 	err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3766 	if (err) {
3767 		bpf_link_cleanup(&link_primer);
3768 		link = NULL;
3769 		goto out_unlock;
3770 	}
3771 
3772 	link->tgt_prog = tgt_prog;
3773 	link->trampoline = tr;
3774 
3775 	/* Always clear the trampoline and target prog from prog->aux to make
3776 	 * sure the original attach destination is not kept alive after a
3777 	 * program is (re-)attached to another target.
3778 	 */
3779 	if (prog->aux->dst_prog &&
3780 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3781 		/* got extra prog ref from syscall, or attaching to different prog */
3782 		bpf_prog_put(prog->aux->dst_prog);
3783 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3784 		/* we allocated a new trampoline, so free the old one */
3785 		bpf_trampoline_put(prog->aux->dst_trampoline);
3786 
3787 	prog->aux->dst_prog = NULL;
3788 	prog->aux->dst_trampoline = NULL;
3789 	mutex_unlock(&prog->aux->dst_mutex);
3790 
3791 	return bpf_link_settle(&link_primer);
3792 out_unlock:
3793 	if (tr && tr != prog->aux->dst_trampoline)
3794 		bpf_trampoline_put(tr);
3795 	mutex_unlock(&prog->aux->dst_mutex);
3796 	kfree(link);
3797 out_put_prog:
3798 	if (tgt_prog_fd && tgt_prog)
3799 		bpf_prog_put(tgt_prog);
3800 	return err;
3801 }
3802 
bpf_raw_tp_link_release(struct bpf_link * link)3803 static void bpf_raw_tp_link_release(struct bpf_link *link)
3804 {
3805 	struct bpf_raw_tp_link *raw_tp =
3806 		container_of(link, struct bpf_raw_tp_link, link);
3807 
3808 	bpf_probe_unregister(raw_tp->btp, raw_tp);
3809 	bpf_put_raw_tracepoint(raw_tp->btp);
3810 }
3811 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3812 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3813 {
3814 	struct bpf_raw_tp_link *raw_tp =
3815 		container_of(link, struct bpf_raw_tp_link, link);
3816 
3817 	kfree(raw_tp);
3818 }
3819 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3820 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3821 					struct seq_file *seq)
3822 {
3823 	struct bpf_raw_tp_link *raw_tp_link =
3824 		container_of(link, struct bpf_raw_tp_link, link);
3825 
3826 	seq_printf(seq,
3827 		   "tp_name:\t%s\n"
3828 		   "cookie:\t%llu\n",
3829 		   raw_tp_link->btp->tp->name,
3830 		   raw_tp_link->cookie);
3831 }
3832 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3833 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3834 			    u32 len)
3835 {
3836 	if (ulen >= len + 1) {
3837 		if (copy_to_user(ubuf, buf, len + 1))
3838 			return -EFAULT;
3839 	} else {
3840 		char zero = '\0';
3841 
3842 		if (copy_to_user(ubuf, buf, ulen - 1))
3843 			return -EFAULT;
3844 		if (put_user(zero, ubuf + ulen - 1))
3845 			return -EFAULT;
3846 		return -ENOSPC;
3847 	}
3848 
3849 	return 0;
3850 }
3851 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3852 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3853 					  struct bpf_link_info *info)
3854 {
3855 	struct bpf_raw_tp_link *raw_tp_link =
3856 		container_of(link, struct bpf_raw_tp_link, link);
3857 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3858 	const char *tp_name = raw_tp_link->btp->tp->name;
3859 	u32 ulen = info->raw_tracepoint.tp_name_len;
3860 	size_t tp_len = strlen(tp_name);
3861 
3862 	if (!ulen ^ !ubuf)
3863 		return -EINVAL;
3864 
3865 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3866 	info->raw_tracepoint.cookie = raw_tp_link->cookie;
3867 
3868 	if (!ubuf)
3869 		return 0;
3870 
3871 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3872 }
3873 
3874 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3875 	.release = bpf_raw_tp_link_release,
3876 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3877 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3878 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3879 };
3880 
3881 #ifdef CONFIG_PERF_EVENTS
3882 struct bpf_perf_link {
3883 	struct bpf_link link;
3884 	struct file *perf_file;
3885 };
3886 
bpf_perf_link_release(struct bpf_link * link)3887 static void bpf_perf_link_release(struct bpf_link *link)
3888 {
3889 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3890 	struct perf_event *event = perf_link->perf_file->private_data;
3891 
3892 	perf_event_free_bpf_prog(event);
3893 	fput(perf_link->perf_file);
3894 }
3895 
bpf_perf_link_dealloc(struct bpf_link * link)3896 static void bpf_perf_link_dealloc(struct bpf_link *link)
3897 {
3898 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3899 
3900 	kfree(perf_link);
3901 }
3902 
bpf_perf_link_fill_common(const struct perf_event * event,char __user * uname,u32 * ulenp,u64 * probe_offset,u64 * probe_addr,u32 * fd_type,unsigned long * missed)3903 static int bpf_perf_link_fill_common(const struct perf_event *event,
3904 				     char __user *uname, u32 *ulenp,
3905 				     u64 *probe_offset, u64 *probe_addr,
3906 				     u32 *fd_type, unsigned long *missed)
3907 {
3908 	const char *buf;
3909 	u32 prog_id, ulen;
3910 	size_t len;
3911 	int err;
3912 
3913 	ulen = *ulenp;
3914 	if (!ulen ^ !uname)
3915 		return -EINVAL;
3916 
3917 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3918 				      probe_offset, probe_addr, missed);
3919 	if (err)
3920 		return err;
3921 
3922 	if (buf) {
3923 		len = strlen(buf);
3924 		*ulenp = len + 1;
3925 	} else {
3926 		*ulenp = 1;
3927 	}
3928 	if (!uname)
3929 		return 0;
3930 
3931 	if (buf) {
3932 		err = bpf_copy_to_user(uname, buf, ulen, len);
3933 		if (err)
3934 			return err;
3935 	} else {
3936 		char zero = '\0';
3937 
3938 		if (put_user(zero, uname))
3939 			return -EFAULT;
3940 	}
3941 	return 0;
3942 }
3943 
3944 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3945 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3946 				     struct bpf_link_info *info)
3947 {
3948 	unsigned long missed;
3949 	char __user *uname;
3950 	u64 addr, offset;
3951 	u32 ulen, type;
3952 	int err;
3953 
3954 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3955 	ulen = info->perf_event.kprobe.name_len;
3956 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3957 					&type, &missed);
3958 	if (err)
3959 		return err;
3960 	if (type == BPF_FD_TYPE_KRETPROBE)
3961 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3962 	else
3963 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3964 	info->perf_event.kprobe.name_len = ulen;
3965 	info->perf_event.kprobe.offset = offset;
3966 	info->perf_event.kprobe.missed = missed;
3967 	if (!kallsyms_show_value(current_cred()))
3968 		addr = 0;
3969 	info->perf_event.kprobe.addr = addr;
3970 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3971 	return 0;
3972 }
3973 
bpf_perf_link_fdinfo_kprobe(const struct perf_event * event,struct seq_file * seq)3974 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event,
3975 					struct seq_file *seq)
3976 {
3977 	const char *name;
3978 	int err;
3979 	u32 prog_id, type;
3980 	u64 offset, addr;
3981 	unsigned long missed;
3982 
3983 	err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
3984 				      &offset, &addr, &missed);
3985 	if (err)
3986 		return;
3987 
3988 	seq_printf(seq,
3989 		   "name:\t%s\n"
3990 		   "offset:\t%#llx\n"
3991 		   "missed:\t%lu\n"
3992 		   "addr:\t%#llx\n"
3993 		   "event_type:\t%s\n"
3994 		   "cookie:\t%llu\n",
3995 		   name, offset, missed, addr,
3996 		   type == BPF_FD_TYPE_KRETPROBE ?  "kretprobe" : "kprobe",
3997 		   event->bpf_cookie);
3998 }
3999 #endif
4000 
4001 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)4002 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
4003 				     struct bpf_link_info *info)
4004 {
4005 	u64 ref_ctr_offset, offset;
4006 	char __user *uname;
4007 	u32 ulen, type;
4008 	int err;
4009 
4010 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
4011 	ulen = info->perf_event.uprobe.name_len;
4012 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset,
4013 					&type, NULL);
4014 	if (err)
4015 		return err;
4016 
4017 	if (type == BPF_FD_TYPE_URETPROBE)
4018 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
4019 	else
4020 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
4021 	info->perf_event.uprobe.name_len = ulen;
4022 	info->perf_event.uprobe.offset = offset;
4023 	info->perf_event.uprobe.cookie = event->bpf_cookie;
4024 	info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset;
4025 	return 0;
4026 }
4027 
bpf_perf_link_fdinfo_uprobe(const struct perf_event * event,struct seq_file * seq)4028 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event,
4029 					struct seq_file *seq)
4030 {
4031 	const char *name;
4032 	int err;
4033 	u32 prog_id, type;
4034 	u64 offset, ref_ctr_offset;
4035 	unsigned long missed;
4036 
4037 	err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
4038 				      &offset, &ref_ctr_offset, &missed);
4039 	if (err)
4040 		return;
4041 
4042 	seq_printf(seq,
4043 		   "name:\t%s\n"
4044 		   "offset:\t%#llx\n"
4045 		   "ref_ctr_offset:\t%#llx\n"
4046 		   "event_type:\t%s\n"
4047 		   "cookie:\t%llu\n",
4048 		   name, offset, ref_ctr_offset,
4049 		   type == BPF_FD_TYPE_URETPROBE ?  "uretprobe" : "uprobe",
4050 		   event->bpf_cookie);
4051 }
4052 #endif
4053 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)4054 static int bpf_perf_link_fill_probe(const struct perf_event *event,
4055 				    struct bpf_link_info *info)
4056 {
4057 #ifdef CONFIG_KPROBE_EVENTS
4058 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4059 		return bpf_perf_link_fill_kprobe(event, info);
4060 #endif
4061 #ifdef CONFIG_UPROBE_EVENTS
4062 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4063 		return bpf_perf_link_fill_uprobe(event, info);
4064 #endif
4065 	return -EOPNOTSUPP;
4066 }
4067 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)4068 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
4069 					 struct bpf_link_info *info)
4070 {
4071 	char __user *uname;
4072 	u32 ulen;
4073 	int err;
4074 
4075 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
4076 	ulen = info->perf_event.tracepoint.name_len;
4077 	err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
4078 	if (err)
4079 		return err;
4080 
4081 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
4082 	info->perf_event.tracepoint.name_len = ulen;
4083 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
4084 	return 0;
4085 }
4086 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)4087 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
4088 					 struct bpf_link_info *info)
4089 {
4090 	info->perf_event.event.type = event->attr.type;
4091 	info->perf_event.event.config = event->attr.config;
4092 	info->perf_event.event.cookie = event->bpf_cookie;
4093 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
4094 	return 0;
4095 }
4096 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)4097 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
4098 					struct bpf_link_info *info)
4099 {
4100 	struct bpf_perf_link *perf_link;
4101 	const struct perf_event *event;
4102 
4103 	perf_link = container_of(link, struct bpf_perf_link, link);
4104 	event = perf_get_event(perf_link->perf_file);
4105 	if (IS_ERR(event))
4106 		return PTR_ERR(event);
4107 
4108 	switch (event->prog->type) {
4109 	case BPF_PROG_TYPE_PERF_EVENT:
4110 		return bpf_perf_link_fill_perf_event(event, info);
4111 	case BPF_PROG_TYPE_TRACEPOINT:
4112 		return bpf_perf_link_fill_tracepoint(event, info);
4113 	case BPF_PROG_TYPE_KPROBE:
4114 		return bpf_perf_link_fill_probe(event, info);
4115 	default:
4116 		return -EOPNOTSUPP;
4117 	}
4118 }
4119 
bpf_perf_event_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4120 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event,
4121 					    struct seq_file *seq)
4122 {
4123 	seq_printf(seq,
4124 		   "type:\t%u\n"
4125 		   "config:\t%llu\n"
4126 		   "event_type:\t%s\n"
4127 		   "cookie:\t%llu\n",
4128 		   event->attr.type, event->attr.config,
4129 		   "event", event->bpf_cookie);
4130 }
4131 
bpf_tracepoint_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4132 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event,
4133 					    struct seq_file *seq)
4134 {
4135 	int err;
4136 	const char *name;
4137 	u32 prog_id;
4138 
4139 	err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL,
4140 				      NULL, NULL);
4141 	if (err)
4142 		return;
4143 
4144 	seq_printf(seq,
4145 		   "tp_name:\t%s\n"
4146 		   "event_type:\t%s\n"
4147 		   "cookie:\t%llu\n",
4148 		   name, "tracepoint", event->bpf_cookie);
4149 }
4150 
bpf_probe_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4151 static void bpf_probe_link_show_fdinfo(const struct perf_event *event,
4152 				       struct seq_file *seq)
4153 {
4154 #ifdef CONFIG_KPROBE_EVENTS
4155 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4156 		return bpf_perf_link_fdinfo_kprobe(event, seq);
4157 #endif
4158 
4159 #ifdef CONFIG_UPROBE_EVENTS
4160 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4161 		return bpf_perf_link_fdinfo_uprobe(event, seq);
4162 #endif
4163 }
4164 
bpf_perf_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)4165 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link,
4166 				      struct seq_file *seq)
4167 {
4168 	struct bpf_perf_link *perf_link;
4169 	const struct perf_event *event;
4170 
4171 	perf_link = container_of(link, struct bpf_perf_link, link);
4172 	event = perf_get_event(perf_link->perf_file);
4173 	if (IS_ERR(event))
4174 		return;
4175 
4176 	switch (event->prog->type) {
4177 	case BPF_PROG_TYPE_PERF_EVENT:
4178 		return bpf_perf_event_link_show_fdinfo(event, seq);
4179 	case BPF_PROG_TYPE_TRACEPOINT:
4180 		return bpf_tracepoint_link_show_fdinfo(event, seq);
4181 	case BPF_PROG_TYPE_KPROBE:
4182 		return bpf_probe_link_show_fdinfo(event, seq);
4183 	default:
4184 		return;
4185 	}
4186 }
4187 
4188 static const struct bpf_link_ops bpf_perf_link_lops = {
4189 	.release = bpf_perf_link_release,
4190 	.dealloc = bpf_perf_link_dealloc,
4191 	.fill_link_info = bpf_perf_link_fill_link_info,
4192 	.show_fdinfo = bpf_perf_link_show_fdinfo,
4193 };
4194 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4195 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4196 {
4197 	struct bpf_link_primer link_primer;
4198 	struct bpf_perf_link *link;
4199 	struct perf_event *event;
4200 	struct file *perf_file;
4201 	int err;
4202 
4203 	if (attr->link_create.flags)
4204 		return -EINVAL;
4205 
4206 	perf_file = perf_event_get(attr->link_create.target_fd);
4207 	if (IS_ERR(perf_file))
4208 		return PTR_ERR(perf_file);
4209 
4210 	link = kzalloc_obj(*link, GFP_USER);
4211 	if (!link) {
4212 		err = -ENOMEM;
4213 		goto out_put_file;
4214 	}
4215 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog,
4216 		      attr->link_create.attach_type);
4217 	link->perf_file = perf_file;
4218 
4219 	err = bpf_link_prime(&link->link, &link_primer);
4220 	if (err) {
4221 		kfree(link);
4222 		goto out_put_file;
4223 	}
4224 
4225 	event = perf_file->private_data;
4226 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
4227 	if (err) {
4228 		bpf_link_cleanup(&link_primer);
4229 		goto out_put_file;
4230 	}
4231 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
4232 	bpf_prog_inc(prog);
4233 
4234 	return bpf_link_settle(&link_primer);
4235 
4236 out_put_file:
4237 	fput(perf_file);
4238 	return err;
4239 }
4240 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4241 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4242 {
4243 	return -EOPNOTSUPP;
4244 }
4245 #endif /* CONFIG_PERF_EVENTS */
4246 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie,enum bpf_attach_type attach_type)4247 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
4248 				  const char __user *user_tp_name, u64 cookie,
4249 				  enum bpf_attach_type attach_type)
4250 {
4251 	struct bpf_link_primer link_primer;
4252 	struct bpf_raw_tp_link *link;
4253 	struct bpf_raw_event_map *btp;
4254 	const char *tp_name;
4255 	char buf[128];
4256 	int err;
4257 
4258 	switch (prog->type) {
4259 	case BPF_PROG_TYPE_TRACING:
4260 	case BPF_PROG_TYPE_EXT:
4261 	case BPF_PROG_TYPE_LSM:
4262 		if (user_tp_name)
4263 			/* The attach point for this category of programs
4264 			 * should be specified via btf_id during program load.
4265 			 */
4266 			return -EINVAL;
4267 		if (prog->type == BPF_PROG_TYPE_TRACING &&
4268 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
4269 			tp_name = prog->aux->attach_func_name;
4270 			break;
4271 		}
4272 		return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type);
4273 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
4274 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
4275 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
4276 			return -EFAULT;
4277 		buf[sizeof(buf) - 1] = 0;
4278 		tp_name = buf;
4279 		break;
4280 	default:
4281 		return -EINVAL;
4282 	}
4283 
4284 	btp = bpf_get_raw_tracepoint(tp_name);
4285 	if (!btp)
4286 		return -ENOENT;
4287 
4288 	link = kzalloc_obj(*link, GFP_USER);
4289 	if (!link) {
4290 		err = -ENOMEM;
4291 		goto out_put_btp;
4292 	}
4293 	bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
4294 				&bpf_raw_tp_link_lops, prog, attach_type,
4295 				tracepoint_is_faultable(btp->tp));
4296 	link->btp = btp;
4297 	link->cookie = cookie;
4298 
4299 	err = bpf_link_prime(&link->link, &link_primer);
4300 	if (err) {
4301 		kfree(link);
4302 		goto out_put_btp;
4303 	}
4304 
4305 	err = bpf_probe_register(link->btp, link);
4306 	if (err) {
4307 		bpf_link_cleanup(&link_primer);
4308 		goto out_put_btp;
4309 	}
4310 
4311 	return bpf_link_settle(&link_primer);
4312 
4313 out_put_btp:
4314 	bpf_put_raw_tracepoint(btp);
4315 	return err;
4316 }
4317 
4318 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4319 
bpf_raw_tracepoint_open(const union bpf_attr * attr)4320 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4321 {
4322 	struct bpf_prog *prog;
4323 	void __user *tp_name;
4324 	__u64 cookie;
4325 	int fd;
4326 
4327 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4328 		return -EINVAL;
4329 
4330 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4331 	if (IS_ERR(prog))
4332 		return PTR_ERR(prog);
4333 
4334 	tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4335 	cookie = attr->raw_tracepoint.cookie;
4336 	fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type);
4337 	if (fd < 0)
4338 		bpf_prog_put(prog);
4339 	return fd;
4340 }
4341 
4342 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4343 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4344 {
4345 	switch (attach_type) {
4346 	case BPF_CGROUP_INET_INGRESS:
4347 	case BPF_CGROUP_INET_EGRESS:
4348 		return BPF_PROG_TYPE_CGROUP_SKB;
4349 	case BPF_CGROUP_INET_SOCK_CREATE:
4350 	case BPF_CGROUP_INET_SOCK_RELEASE:
4351 	case BPF_CGROUP_INET4_POST_BIND:
4352 	case BPF_CGROUP_INET6_POST_BIND:
4353 		return BPF_PROG_TYPE_CGROUP_SOCK;
4354 	case BPF_CGROUP_INET4_BIND:
4355 	case BPF_CGROUP_INET6_BIND:
4356 	case BPF_CGROUP_INET4_CONNECT:
4357 	case BPF_CGROUP_INET6_CONNECT:
4358 	case BPF_CGROUP_UNIX_CONNECT:
4359 	case BPF_CGROUP_INET4_GETPEERNAME:
4360 	case BPF_CGROUP_INET6_GETPEERNAME:
4361 	case BPF_CGROUP_UNIX_GETPEERNAME:
4362 	case BPF_CGROUP_INET4_GETSOCKNAME:
4363 	case BPF_CGROUP_INET6_GETSOCKNAME:
4364 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4365 	case BPF_CGROUP_UDP4_SENDMSG:
4366 	case BPF_CGROUP_UDP6_SENDMSG:
4367 	case BPF_CGROUP_UNIX_SENDMSG:
4368 	case BPF_CGROUP_UDP4_RECVMSG:
4369 	case BPF_CGROUP_UDP6_RECVMSG:
4370 	case BPF_CGROUP_UNIX_RECVMSG:
4371 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4372 	case BPF_CGROUP_SOCK_OPS:
4373 		return BPF_PROG_TYPE_SOCK_OPS;
4374 	case BPF_CGROUP_DEVICE:
4375 		return BPF_PROG_TYPE_CGROUP_DEVICE;
4376 	case BPF_SK_MSG_VERDICT:
4377 		return BPF_PROG_TYPE_SK_MSG;
4378 	case BPF_SK_SKB_STREAM_PARSER:
4379 	case BPF_SK_SKB_STREAM_VERDICT:
4380 	case BPF_SK_SKB_VERDICT:
4381 		return BPF_PROG_TYPE_SK_SKB;
4382 	case BPF_LIRC_MODE2:
4383 		return BPF_PROG_TYPE_LIRC_MODE2;
4384 	case BPF_FLOW_DISSECTOR:
4385 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
4386 	case BPF_CGROUP_SYSCTL:
4387 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
4388 	case BPF_CGROUP_GETSOCKOPT:
4389 	case BPF_CGROUP_SETSOCKOPT:
4390 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4391 	case BPF_TRACE_ITER:
4392 	case BPF_TRACE_RAW_TP:
4393 	case BPF_TRACE_FENTRY:
4394 	case BPF_TRACE_FEXIT:
4395 	case BPF_TRACE_FSESSION:
4396 	case BPF_MODIFY_RETURN:
4397 		return BPF_PROG_TYPE_TRACING;
4398 	case BPF_LSM_MAC:
4399 		return BPF_PROG_TYPE_LSM;
4400 	case BPF_SK_LOOKUP:
4401 		return BPF_PROG_TYPE_SK_LOOKUP;
4402 	case BPF_XDP:
4403 		return BPF_PROG_TYPE_XDP;
4404 	case BPF_LSM_CGROUP:
4405 		return BPF_PROG_TYPE_LSM;
4406 	case BPF_TCX_INGRESS:
4407 	case BPF_TCX_EGRESS:
4408 	case BPF_NETKIT_PRIMARY:
4409 	case BPF_NETKIT_PEER:
4410 		return BPF_PROG_TYPE_SCHED_CLS;
4411 	default:
4412 		return BPF_PROG_TYPE_UNSPEC;
4413 	}
4414 }
4415 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4416 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4417 					     enum bpf_attach_type attach_type)
4418 {
4419 	enum bpf_prog_type ptype;
4420 
4421 	switch (prog->type) {
4422 	case BPF_PROG_TYPE_CGROUP_SOCK:
4423 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4424 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4425 	case BPF_PROG_TYPE_SK_LOOKUP:
4426 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4427 	case BPF_PROG_TYPE_CGROUP_SKB:
4428 		if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4429 			/* cg-skb progs can be loaded by unpriv user.
4430 			 * check permissions at attach time.
4431 			 */
4432 			return -EPERM;
4433 
4434 		ptype = attach_type_to_prog_type(attach_type);
4435 		if (prog->type != ptype)
4436 			return -EINVAL;
4437 
4438 		return prog->enforce_expected_attach_type &&
4439 			prog->expected_attach_type != attach_type ?
4440 			-EINVAL : 0;
4441 	case BPF_PROG_TYPE_EXT:
4442 		return 0;
4443 	case BPF_PROG_TYPE_NETFILTER:
4444 		if (attach_type != BPF_NETFILTER)
4445 			return -EINVAL;
4446 		return 0;
4447 	case BPF_PROG_TYPE_PERF_EVENT:
4448 	case BPF_PROG_TYPE_TRACEPOINT:
4449 		if (attach_type != BPF_PERF_EVENT)
4450 			return -EINVAL;
4451 		return 0;
4452 	case BPF_PROG_TYPE_KPROBE:
4453 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4454 		    attach_type != BPF_TRACE_KPROBE_MULTI)
4455 			return -EINVAL;
4456 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4457 		    attach_type != BPF_TRACE_KPROBE_SESSION)
4458 			return -EINVAL;
4459 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4460 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4461 			return -EINVAL;
4462 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4463 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4464 			return -EINVAL;
4465 		if (attach_type != BPF_PERF_EVENT &&
4466 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
4467 		    attach_type != BPF_TRACE_KPROBE_SESSION &&
4468 		    attach_type != BPF_TRACE_UPROBE_MULTI &&
4469 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4470 			return -EINVAL;
4471 		return 0;
4472 	case BPF_PROG_TYPE_SCHED_CLS:
4473 		if (attach_type != BPF_TCX_INGRESS &&
4474 		    attach_type != BPF_TCX_EGRESS &&
4475 		    attach_type != BPF_NETKIT_PRIMARY &&
4476 		    attach_type != BPF_NETKIT_PEER)
4477 			return -EINVAL;
4478 		return 0;
4479 	default:
4480 		ptype = attach_type_to_prog_type(attach_type);
4481 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4482 			return -EINVAL;
4483 		return 0;
4484 	}
4485 }
4486 
is_cgroup_prog_type(enum bpf_prog_type ptype,enum bpf_attach_type atype,bool check_atype)4487 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype,
4488 				bool check_atype)
4489 {
4490 	switch (ptype) {
4491 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4492 	case BPF_PROG_TYPE_CGROUP_SKB:
4493 	case BPF_PROG_TYPE_CGROUP_SOCK:
4494 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4495 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4496 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4497 	case BPF_PROG_TYPE_SOCK_OPS:
4498 		return true;
4499 	case BPF_PROG_TYPE_LSM:
4500 		return check_atype ? atype == BPF_LSM_CGROUP : true;
4501 	default:
4502 		return false;
4503 	}
4504 }
4505 
4506 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4507 
4508 #define BPF_F_ATTACH_MASK_BASE	\
4509 	(BPF_F_ALLOW_OVERRIDE |	\
4510 	 BPF_F_ALLOW_MULTI |	\
4511 	 BPF_F_REPLACE |	\
4512 	 BPF_F_PREORDER)
4513 
4514 #define BPF_F_ATTACH_MASK_MPROG	\
4515 	(BPF_F_REPLACE |	\
4516 	 BPF_F_BEFORE |		\
4517 	 BPF_F_AFTER |		\
4518 	 BPF_F_ID |		\
4519 	 BPF_F_LINK)
4520 
bpf_prog_attach(const union bpf_attr * attr)4521 static int bpf_prog_attach(const union bpf_attr *attr)
4522 {
4523 	enum bpf_prog_type ptype;
4524 	struct bpf_prog *prog;
4525 	int ret;
4526 
4527 	if (CHECK_ATTR(BPF_PROG_ATTACH))
4528 		return -EINVAL;
4529 
4530 	ptype = attach_type_to_prog_type(attr->attach_type);
4531 	if (ptype == BPF_PROG_TYPE_UNSPEC)
4532 		return -EINVAL;
4533 	if (bpf_mprog_supported(ptype)) {
4534 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4535 			return -EINVAL;
4536 	} else if (is_cgroup_prog_type(ptype, 0, false)) {
4537 		if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG))
4538 			return -EINVAL;
4539 	} else {
4540 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4541 			return -EINVAL;
4542 		if (attr->relative_fd ||
4543 		    attr->expected_revision)
4544 			return -EINVAL;
4545 	}
4546 
4547 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4548 	if (IS_ERR(prog))
4549 		return PTR_ERR(prog);
4550 
4551 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4552 		bpf_prog_put(prog);
4553 		return -EINVAL;
4554 	}
4555 
4556 	if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) {
4557 		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4558 		goto out;
4559 	}
4560 
4561 	switch (ptype) {
4562 	case BPF_PROG_TYPE_SK_SKB:
4563 	case BPF_PROG_TYPE_SK_MSG:
4564 		ret = sock_map_get_from_fd(attr, prog);
4565 		break;
4566 	case BPF_PROG_TYPE_LIRC_MODE2:
4567 		ret = lirc_prog_attach(attr, prog);
4568 		break;
4569 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4570 		ret = netns_bpf_prog_attach(attr, prog);
4571 		break;
4572 	case BPF_PROG_TYPE_SCHED_CLS:
4573 		if (attr->attach_type == BPF_TCX_INGRESS ||
4574 		    attr->attach_type == BPF_TCX_EGRESS)
4575 			ret = tcx_prog_attach(attr, prog);
4576 		else
4577 			ret = netkit_prog_attach(attr, prog);
4578 		break;
4579 	default:
4580 		ret = -EINVAL;
4581 	}
4582 out:
4583 	if (ret)
4584 		bpf_prog_put(prog);
4585 	return ret;
4586 }
4587 
4588 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4589 
bpf_prog_detach(const union bpf_attr * attr)4590 static int bpf_prog_detach(const union bpf_attr *attr)
4591 {
4592 	struct bpf_prog *prog = NULL;
4593 	enum bpf_prog_type ptype;
4594 	int ret;
4595 
4596 	if (CHECK_ATTR(BPF_PROG_DETACH))
4597 		return -EINVAL;
4598 
4599 	ptype = attach_type_to_prog_type(attr->attach_type);
4600 	if (bpf_mprog_supported(ptype)) {
4601 		if (ptype == BPF_PROG_TYPE_UNSPEC)
4602 			return -EINVAL;
4603 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4604 			return -EINVAL;
4605 		if (attr->attach_bpf_fd) {
4606 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4607 			if (IS_ERR(prog))
4608 				return PTR_ERR(prog);
4609 		} else if (!bpf_mprog_detach_empty(ptype)) {
4610 			return -EPERM;
4611 		}
4612 	} else if (is_cgroup_prog_type(ptype, 0, false)) {
4613 		if (attr->attach_flags || attr->relative_fd)
4614 			return -EINVAL;
4615 	} else if (attr->attach_flags ||
4616 		   attr->relative_fd ||
4617 		   attr->expected_revision) {
4618 		return -EINVAL;
4619 	}
4620 
4621 	switch (ptype) {
4622 	case BPF_PROG_TYPE_SK_MSG:
4623 	case BPF_PROG_TYPE_SK_SKB:
4624 		ret = sock_map_prog_detach(attr, ptype);
4625 		break;
4626 	case BPF_PROG_TYPE_LIRC_MODE2:
4627 		ret = lirc_prog_detach(attr);
4628 		break;
4629 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4630 		ret = netns_bpf_prog_detach(attr, ptype);
4631 		break;
4632 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4633 	case BPF_PROG_TYPE_CGROUP_SKB:
4634 	case BPF_PROG_TYPE_CGROUP_SOCK:
4635 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4636 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4637 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4638 	case BPF_PROG_TYPE_SOCK_OPS:
4639 	case BPF_PROG_TYPE_LSM:
4640 		ret = cgroup_bpf_prog_detach(attr, ptype);
4641 		break;
4642 	case BPF_PROG_TYPE_SCHED_CLS:
4643 		if (attr->attach_type == BPF_TCX_INGRESS ||
4644 		    attr->attach_type == BPF_TCX_EGRESS)
4645 			ret = tcx_prog_detach(attr, prog);
4646 		else
4647 			ret = netkit_prog_detach(attr, prog);
4648 		break;
4649 	default:
4650 		ret = -EINVAL;
4651 	}
4652 
4653 	if (prog)
4654 		bpf_prog_put(prog);
4655 	return ret;
4656 }
4657 
4658 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4659 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4660 static int bpf_prog_query(const union bpf_attr *attr,
4661 			  union bpf_attr __user *uattr)
4662 {
4663 	if (!bpf_net_capable())
4664 		return -EPERM;
4665 	if (CHECK_ATTR(BPF_PROG_QUERY))
4666 		return -EINVAL;
4667 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4668 		return -EINVAL;
4669 
4670 	switch (attr->query.attach_type) {
4671 	case BPF_CGROUP_INET_INGRESS:
4672 	case BPF_CGROUP_INET_EGRESS:
4673 	case BPF_CGROUP_INET_SOCK_CREATE:
4674 	case BPF_CGROUP_INET_SOCK_RELEASE:
4675 	case BPF_CGROUP_INET4_BIND:
4676 	case BPF_CGROUP_INET6_BIND:
4677 	case BPF_CGROUP_INET4_POST_BIND:
4678 	case BPF_CGROUP_INET6_POST_BIND:
4679 	case BPF_CGROUP_INET4_CONNECT:
4680 	case BPF_CGROUP_INET6_CONNECT:
4681 	case BPF_CGROUP_UNIX_CONNECT:
4682 	case BPF_CGROUP_INET4_GETPEERNAME:
4683 	case BPF_CGROUP_INET6_GETPEERNAME:
4684 	case BPF_CGROUP_UNIX_GETPEERNAME:
4685 	case BPF_CGROUP_INET4_GETSOCKNAME:
4686 	case BPF_CGROUP_INET6_GETSOCKNAME:
4687 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4688 	case BPF_CGROUP_UDP4_SENDMSG:
4689 	case BPF_CGROUP_UDP6_SENDMSG:
4690 	case BPF_CGROUP_UNIX_SENDMSG:
4691 	case BPF_CGROUP_UDP4_RECVMSG:
4692 	case BPF_CGROUP_UDP6_RECVMSG:
4693 	case BPF_CGROUP_UNIX_RECVMSG:
4694 	case BPF_CGROUP_SOCK_OPS:
4695 	case BPF_CGROUP_DEVICE:
4696 	case BPF_CGROUP_SYSCTL:
4697 	case BPF_CGROUP_GETSOCKOPT:
4698 	case BPF_CGROUP_SETSOCKOPT:
4699 	case BPF_LSM_CGROUP:
4700 		return cgroup_bpf_prog_query(attr, uattr);
4701 	case BPF_LIRC_MODE2:
4702 		return lirc_prog_query(attr, uattr);
4703 	case BPF_FLOW_DISSECTOR:
4704 	case BPF_SK_LOOKUP:
4705 		return netns_bpf_prog_query(attr, uattr);
4706 	case BPF_SK_SKB_STREAM_PARSER:
4707 	case BPF_SK_SKB_STREAM_VERDICT:
4708 	case BPF_SK_MSG_VERDICT:
4709 	case BPF_SK_SKB_VERDICT:
4710 		return sock_map_bpf_prog_query(attr, uattr);
4711 	case BPF_TCX_INGRESS:
4712 	case BPF_TCX_EGRESS:
4713 		return tcx_prog_query(attr, uattr);
4714 	case BPF_NETKIT_PRIMARY:
4715 	case BPF_NETKIT_PEER:
4716 		return netkit_prog_query(attr, uattr);
4717 	default:
4718 		return -EINVAL;
4719 	}
4720 }
4721 
4722 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4723 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4724 static int bpf_prog_test_run(const union bpf_attr *attr,
4725 			     union bpf_attr __user *uattr)
4726 {
4727 	struct bpf_prog *prog;
4728 	int ret = -ENOTSUPP;
4729 
4730 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4731 		return -EINVAL;
4732 
4733 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4734 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4735 		return -EINVAL;
4736 
4737 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4738 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4739 		return -EINVAL;
4740 
4741 	prog = bpf_prog_get(attr->test.prog_fd);
4742 	if (IS_ERR(prog))
4743 		return PTR_ERR(prog);
4744 
4745 	if (prog->aux->ops->test_run)
4746 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4747 
4748 	bpf_prog_put(prog);
4749 	return ret;
4750 }
4751 
4752 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4753 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4754 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4755 			       union bpf_attr __user *uattr,
4756 			       struct idr *idr,
4757 			       spinlock_t *lock)
4758 {
4759 	u32 next_id = attr->start_id;
4760 	int err = 0;
4761 
4762 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4763 		return -EINVAL;
4764 
4765 	if (!capable(CAP_SYS_ADMIN))
4766 		return -EPERM;
4767 
4768 	next_id++;
4769 	spin_lock_bh(lock);
4770 	if (!idr_get_next(idr, &next_id))
4771 		err = -ENOENT;
4772 	spin_unlock_bh(lock);
4773 
4774 	if (!err)
4775 		err = put_user(next_id, &uattr->next_id);
4776 
4777 	return err;
4778 }
4779 
bpf_map_get_curr_or_next(u32 * id)4780 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4781 {
4782 	struct bpf_map *map;
4783 
4784 	spin_lock_bh(&map_idr_lock);
4785 again:
4786 	map = idr_get_next(&map_idr, id);
4787 	if (map) {
4788 		map = __bpf_map_inc_not_zero(map, false);
4789 		if (IS_ERR(map)) {
4790 			(*id)++;
4791 			goto again;
4792 		}
4793 	}
4794 	spin_unlock_bh(&map_idr_lock);
4795 
4796 	return map;
4797 }
4798 
bpf_prog_get_curr_or_next(u32 * id)4799 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4800 {
4801 	struct bpf_prog *prog;
4802 
4803 	spin_lock_bh(&prog_idr_lock);
4804 again:
4805 	prog = idr_get_next(&prog_idr, id);
4806 	if (prog) {
4807 		prog = bpf_prog_inc_not_zero(prog);
4808 		if (IS_ERR(prog)) {
4809 			(*id)++;
4810 			goto again;
4811 		}
4812 	}
4813 	spin_unlock_bh(&prog_idr_lock);
4814 
4815 	return prog;
4816 }
4817 
4818 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4819 
bpf_prog_by_id(u32 id)4820 struct bpf_prog *bpf_prog_by_id(u32 id)
4821 {
4822 	struct bpf_prog *prog;
4823 
4824 	if (!id)
4825 		return ERR_PTR(-ENOENT);
4826 
4827 	spin_lock_bh(&prog_idr_lock);
4828 	prog = idr_find(&prog_idr, id);
4829 	if (prog)
4830 		prog = bpf_prog_inc_not_zero(prog);
4831 	else
4832 		prog = ERR_PTR(-ENOENT);
4833 	spin_unlock_bh(&prog_idr_lock);
4834 	return prog;
4835 }
4836 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4837 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4838 {
4839 	struct bpf_prog *prog;
4840 	u32 id = attr->prog_id;
4841 	int fd;
4842 
4843 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4844 		return -EINVAL;
4845 
4846 	if (!capable(CAP_SYS_ADMIN))
4847 		return -EPERM;
4848 
4849 	prog = bpf_prog_by_id(id);
4850 	if (IS_ERR(prog))
4851 		return PTR_ERR(prog);
4852 
4853 	fd = bpf_prog_new_fd(prog);
4854 	if (fd < 0)
4855 		bpf_prog_put(prog);
4856 
4857 	return fd;
4858 }
4859 
4860 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4861 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4862 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4863 {
4864 	struct bpf_map *map;
4865 	u32 id = attr->map_id;
4866 	int f_flags;
4867 	int fd;
4868 
4869 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4870 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4871 		return -EINVAL;
4872 
4873 	if (!capable(CAP_SYS_ADMIN))
4874 		return -EPERM;
4875 
4876 	f_flags = bpf_get_file_flag(attr->open_flags);
4877 	if (f_flags < 0)
4878 		return f_flags;
4879 
4880 	spin_lock_bh(&map_idr_lock);
4881 	map = idr_find(&map_idr, id);
4882 	if (map)
4883 		map = __bpf_map_inc_not_zero(map, true);
4884 	else
4885 		map = ERR_PTR(-ENOENT);
4886 	spin_unlock_bh(&map_idr_lock);
4887 
4888 	if (IS_ERR(map))
4889 		return PTR_ERR(map);
4890 
4891 	fd = bpf_map_new_fd(map, f_flags);
4892 	if (fd < 0)
4893 		bpf_map_put_with_uref(map);
4894 
4895 	return fd;
4896 }
4897 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4898 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4899 					      unsigned long addr, u32 *off,
4900 					      u32 *type)
4901 {
4902 	const struct bpf_map *map;
4903 	int i;
4904 
4905 	mutex_lock(&prog->aux->used_maps_mutex);
4906 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4907 		map = prog->aux->used_maps[i];
4908 		if (map == (void *)addr) {
4909 			*type = BPF_PSEUDO_MAP_FD;
4910 			goto out;
4911 		}
4912 		if (!map->ops->map_direct_value_meta)
4913 			continue;
4914 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4915 			*type = BPF_PSEUDO_MAP_VALUE;
4916 			goto out;
4917 		}
4918 	}
4919 	map = NULL;
4920 
4921 out:
4922 	mutex_unlock(&prog->aux->used_maps_mutex);
4923 	return map;
4924 }
4925 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4926 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4927 					      const struct cred *f_cred)
4928 {
4929 	const struct bpf_map *map;
4930 	struct bpf_insn *insns;
4931 	u32 off, type;
4932 	u64 imm;
4933 	u8 code;
4934 	int i;
4935 
4936 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4937 			GFP_USER);
4938 	if (!insns)
4939 		return insns;
4940 
4941 	for (i = 0; i < prog->len; i++) {
4942 		code = insns[i].code;
4943 
4944 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4945 			insns[i].code = BPF_JMP | BPF_CALL;
4946 			insns[i].imm = BPF_FUNC_tail_call;
4947 			/* fall-through */
4948 		}
4949 		if (code == (BPF_JMP | BPF_CALL) ||
4950 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4951 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4952 				insns[i].code = BPF_JMP | BPF_CALL;
4953 			if (!bpf_dump_raw_ok(f_cred))
4954 				insns[i].imm = 0;
4955 			continue;
4956 		}
4957 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4958 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4959 			continue;
4960 		}
4961 
4962 		if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4963 		     BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4964 			insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4965 			continue;
4966 		}
4967 
4968 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4969 			continue;
4970 
4971 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4972 		map = bpf_map_from_imm(prog, imm, &off, &type);
4973 		if (map) {
4974 			insns[i].src_reg = type;
4975 			insns[i].imm = map->id;
4976 			insns[i + 1].imm = off;
4977 			continue;
4978 		}
4979 	}
4980 
4981 	return insns;
4982 }
4983 
set_info_rec_size(struct bpf_prog_info * info)4984 static int set_info_rec_size(struct bpf_prog_info *info)
4985 {
4986 	/*
4987 	 * Ensure info.*_rec_size is the same as kernel expected size
4988 	 *
4989 	 * or
4990 	 *
4991 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4992 	 * zero.  In this case, the kernel will set the expected
4993 	 * _rec_size back to the info.
4994 	 */
4995 
4996 	if ((info->nr_func_info || info->func_info_rec_size) &&
4997 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4998 		return -EINVAL;
4999 
5000 	if ((info->nr_line_info || info->line_info_rec_size) &&
5001 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
5002 		return -EINVAL;
5003 
5004 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
5005 	    info->jited_line_info_rec_size != sizeof(__u64))
5006 		return -EINVAL;
5007 
5008 	info->func_info_rec_size = sizeof(struct bpf_func_info);
5009 	info->line_info_rec_size = sizeof(struct bpf_line_info);
5010 	info->jited_line_info_rec_size = sizeof(__u64);
5011 
5012 	return 0;
5013 }
5014 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)5015 static int bpf_prog_get_info_by_fd(struct file *file,
5016 				   struct bpf_prog *prog,
5017 				   const union bpf_attr *attr,
5018 				   union bpf_attr __user *uattr)
5019 {
5020 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5021 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
5022 	struct bpf_prog_info info;
5023 	u32 info_len = attr->info.info_len;
5024 	struct bpf_prog_kstats stats;
5025 	char __user *uinsns;
5026 	u32 ulen;
5027 	int err;
5028 
5029 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5030 	if (err)
5031 		return err;
5032 	info_len = min_t(u32, sizeof(info), info_len);
5033 
5034 	memset(&info, 0, sizeof(info));
5035 	if (copy_from_user(&info, uinfo, info_len))
5036 		return -EFAULT;
5037 
5038 	info.type = prog->type;
5039 	info.id = prog->aux->id;
5040 	info.load_time = prog->aux->load_time;
5041 	info.created_by_uid = from_kuid_munged(current_user_ns(),
5042 					       prog->aux->user->uid);
5043 	info.gpl_compatible = prog->gpl_compatible;
5044 
5045 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
5046 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
5047 
5048 	mutex_lock(&prog->aux->used_maps_mutex);
5049 	ulen = info.nr_map_ids;
5050 	info.nr_map_ids = prog->aux->used_map_cnt;
5051 	ulen = min_t(u32, info.nr_map_ids, ulen);
5052 	if (ulen) {
5053 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
5054 		u32 i;
5055 
5056 		for (i = 0; i < ulen; i++)
5057 			if (put_user(prog->aux->used_maps[i]->id,
5058 				     &user_map_ids[i])) {
5059 				mutex_unlock(&prog->aux->used_maps_mutex);
5060 				return -EFAULT;
5061 			}
5062 	}
5063 	mutex_unlock(&prog->aux->used_maps_mutex);
5064 
5065 	err = set_info_rec_size(&info);
5066 	if (err)
5067 		return err;
5068 
5069 	bpf_prog_get_stats(prog, &stats);
5070 	info.run_time_ns = stats.nsecs;
5071 	info.run_cnt = stats.cnt;
5072 	info.recursion_misses = stats.misses;
5073 
5074 	info.verified_insns = prog->aux->verified_insns;
5075 	if (prog->aux->btf)
5076 		info.btf_id = btf_obj_id(prog->aux->btf);
5077 
5078 	if (!bpf_capable()) {
5079 		info.jited_prog_len = 0;
5080 		info.xlated_prog_len = 0;
5081 		info.nr_jited_ksyms = 0;
5082 		info.nr_jited_func_lens = 0;
5083 		info.nr_func_info = 0;
5084 		info.nr_line_info = 0;
5085 		info.nr_jited_line_info = 0;
5086 		goto done;
5087 	}
5088 
5089 	ulen = info.xlated_prog_len;
5090 	info.xlated_prog_len = bpf_prog_insn_size(prog);
5091 	if (info.xlated_prog_len && ulen) {
5092 		struct bpf_insn *insns_sanitized;
5093 		bool fault;
5094 
5095 		if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) {
5096 			insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
5097 			if (!insns_sanitized)
5098 				return -ENOMEM;
5099 			uinsns = u64_to_user_ptr(info.xlated_prog_insns);
5100 			ulen = min_t(u32, info.xlated_prog_len, ulen);
5101 			fault = copy_to_user(uinsns, insns_sanitized, ulen);
5102 			kfree(insns_sanitized);
5103 			if (fault)
5104 				return -EFAULT;
5105 		} else {
5106 			info.xlated_prog_insns = 0;
5107 		}
5108 	}
5109 
5110 	if (bpf_prog_is_offloaded(prog->aux)) {
5111 		err = bpf_prog_offload_info_fill(&info, prog);
5112 		if (err)
5113 			return err;
5114 		goto done;
5115 	}
5116 
5117 	/* NOTE: the following code is supposed to be skipped for offload.
5118 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
5119 	 * for offload.
5120 	 */
5121 	ulen = info.jited_prog_len;
5122 	if (prog->aux->func_cnt) {
5123 		u32 i;
5124 
5125 		info.jited_prog_len = 0;
5126 		for (i = 0; i < prog->aux->func_cnt; i++)
5127 			info.jited_prog_len += prog->aux->func[i]->jited_len;
5128 	} else {
5129 		info.jited_prog_len = prog->jited_len;
5130 	}
5131 
5132 	if (info.jited_prog_len && ulen) {
5133 		if (bpf_dump_raw_ok(file->f_cred)) {
5134 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
5135 			ulen = min_t(u32, info.jited_prog_len, ulen);
5136 
5137 			/* for multi-function programs, copy the JITed
5138 			 * instructions for all the functions
5139 			 */
5140 			if (prog->aux->func_cnt) {
5141 				u32 len, free, i;
5142 				u8 *img;
5143 
5144 				free = ulen;
5145 				for (i = 0; i < prog->aux->func_cnt; i++) {
5146 					len = prog->aux->func[i]->jited_len;
5147 					len = min_t(u32, len, free);
5148 					img = (u8 *) prog->aux->func[i]->bpf_func;
5149 					if (copy_to_user(uinsns, img, len))
5150 						return -EFAULT;
5151 					uinsns += len;
5152 					free -= len;
5153 					if (!free)
5154 						break;
5155 				}
5156 			} else {
5157 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
5158 					return -EFAULT;
5159 			}
5160 		} else {
5161 			info.jited_prog_insns = 0;
5162 		}
5163 	}
5164 
5165 	ulen = info.nr_jited_ksyms;
5166 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
5167 	if (ulen) {
5168 		if (bpf_dump_raw_ok(file->f_cred)) {
5169 			unsigned long ksym_addr;
5170 			u64 __user *user_ksyms;
5171 			u32 i;
5172 
5173 			/* copy the address of the kernel symbol
5174 			 * corresponding to each function
5175 			 */
5176 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
5177 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
5178 			if (prog->aux->func_cnt) {
5179 				for (i = 0; i < ulen; i++) {
5180 					ksym_addr = (unsigned long)
5181 						prog->aux->func[i]->bpf_func;
5182 					if (put_user((u64) ksym_addr,
5183 						     &user_ksyms[i]))
5184 						return -EFAULT;
5185 				}
5186 			} else {
5187 				ksym_addr = (unsigned long) prog->bpf_func;
5188 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
5189 					return -EFAULT;
5190 			}
5191 		} else {
5192 			info.jited_ksyms = 0;
5193 		}
5194 	}
5195 
5196 	ulen = info.nr_jited_func_lens;
5197 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
5198 	if (ulen) {
5199 		if (bpf_dump_raw_ok(file->f_cred)) {
5200 			u32 __user *user_lens;
5201 			u32 func_len, i;
5202 
5203 			/* copy the JITed image lengths for each function */
5204 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
5205 			user_lens = u64_to_user_ptr(info.jited_func_lens);
5206 			if (prog->aux->func_cnt) {
5207 				for (i = 0; i < ulen; i++) {
5208 					func_len =
5209 						prog->aux->func[i]->jited_len;
5210 					if (put_user(func_len, &user_lens[i]))
5211 						return -EFAULT;
5212 				}
5213 			} else {
5214 				func_len = prog->jited_len;
5215 				if (put_user(func_len, &user_lens[0]))
5216 					return -EFAULT;
5217 			}
5218 		} else {
5219 			info.jited_func_lens = 0;
5220 		}
5221 	}
5222 
5223 	info.attach_btf_id = prog->aux->attach_btf_id;
5224 	if (attach_btf)
5225 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
5226 
5227 	ulen = info.nr_func_info;
5228 	info.nr_func_info = prog->aux->func_info_cnt;
5229 	if (info.nr_func_info && ulen) {
5230 		char __user *user_finfo;
5231 
5232 		user_finfo = u64_to_user_ptr(info.func_info);
5233 		ulen = min_t(u32, info.nr_func_info, ulen);
5234 		if (copy_to_user(user_finfo, prog->aux->func_info,
5235 				 info.func_info_rec_size * ulen))
5236 			return -EFAULT;
5237 	}
5238 
5239 	ulen = info.nr_line_info;
5240 	info.nr_line_info = prog->aux->nr_linfo;
5241 	if (info.nr_line_info && ulen) {
5242 		__u8 __user *user_linfo;
5243 
5244 		user_linfo = u64_to_user_ptr(info.line_info);
5245 		ulen = min_t(u32, info.nr_line_info, ulen);
5246 		if (copy_to_user(user_linfo, prog->aux->linfo,
5247 				 info.line_info_rec_size * ulen))
5248 			return -EFAULT;
5249 	}
5250 
5251 	ulen = info.nr_jited_line_info;
5252 	if (prog->aux->jited_linfo)
5253 		info.nr_jited_line_info = prog->aux->nr_linfo;
5254 	else
5255 		info.nr_jited_line_info = 0;
5256 	if (info.nr_jited_line_info && ulen) {
5257 		if (bpf_dump_raw_ok(file->f_cred)) {
5258 			unsigned long line_addr;
5259 			__u64 __user *user_linfo;
5260 			u32 i;
5261 
5262 			user_linfo = u64_to_user_ptr(info.jited_line_info);
5263 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
5264 			for (i = 0; i < ulen; i++) {
5265 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
5266 				if (put_user((__u64)line_addr, &user_linfo[i]))
5267 					return -EFAULT;
5268 			}
5269 		} else {
5270 			info.jited_line_info = 0;
5271 		}
5272 	}
5273 
5274 	ulen = info.nr_prog_tags;
5275 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
5276 	if (ulen) {
5277 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
5278 		u32 i;
5279 
5280 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
5281 		ulen = min_t(u32, info.nr_prog_tags, ulen);
5282 		if (prog->aux->func_cnt) {
5283 			for (i = 0; i < ulen; i++) {
5284 				if (copy_to_user(user_prog_tags[i],
5285 						 prog->aux->func[i]->tag,
5286 						 BPF_TAG_SIZE))
5287 					return -EFAULT;
5288 			}
5289 		} else {
5290 			if (copy_to_user(user_prog_tags[0],
5291 					 prog->tag, BPF_TAG_SIZE))
5292 				return -EFAULT;
5293 		}
5294 	}
5295 
5296 done:
5297 	if (copy_to_user(uinfo, &info, info_len) ||
5298 	    put_user(info_len, &uattr->info.info_len))
5299 		return -EFAULT;
5300 
5301 	return 0;
5302 }
5303 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)5304 static int bpf_map_get_info_by_fd(struct file *file,
5305 				  struct bpf_map *map,
5306 				  const union bpf_attr *attr,
5307 				  union bpf_attr __user *uattr)
5308 {
5309 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5310 	struct bpf_map_info info;
5311 	u32 info_len = attr->info.info_len;
5312 	int err;
5313 
5314 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5315 	if (err)
5316 		return err;
5317 	info_len = min_t(u32, sizeof(info), info_len);
5318 
5319 	memset(&info, 0, sizeof(info));
5320 	if (copy_from_user(&info, uinfo, info_len))
5321 		return -EFAULT;
5322 
5323 	info.type = map->map_type;
5324 	info.id = map->id;
5325 	info.key_size = map->key_size;
5326 	info.value_size = map->value_size;
5327 	info.max_entries = map->max_entries;
5328 	info.map_flags = map->map_flags;
5329 	info.map_extra = map->map_extra;
5330 	memcpy(info.name, map->name, sizeof(map->name));
5331 
5332 	if (map->btf) {
5333 		info.btf_id = btf_obj_id(map->btf);
5334 		info.btf_key_type_id = map->btf_key_type_id;
5335 		info.btf_value_type_id = map->btf_value_type_id;
5336 	}
5337 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5338 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5339 		bpf_map_struct_ops_info_fill(&info, map);
5340 
5341 	if (bpf_map_is_offloaded(map)) {
5342 		err = bpf_map_offload_info_fill(&info, map);
5343 		if (err)
5344 			return err;
5345 	}
5346 
5347 	if (info.hash) {
5348 		char __user *uhash = u64_to_user_ptr(info.hash);
5349 
5350 		if (!map->ops->map_get_hash)
5351 			return -EINVAL;
5352 
5353 		if (info.hash_size != SHA256_DIGEST_SIZE)
5354 			return -EINVAL;
5355 
5356 		if (!READ_ONCE(map->frozen))
5357 			return -EPERM;
5358 
5359 		err = map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, map->sha);
5360 		if (err != 0)
5361 			return err;
5362 
5363 		if (copy_to_user(uhash, map->sha, SHA256_DIGEST_SIZE) != 0)
5364 			return -EFAULT;
5365 	} else if (info.hash_size) {
5366 		return -EINVAL;
5367 	}
5368 
5369 	if (copy_to_user(uinfo, &info, info_len) ||
5370 	    put_user(info_len, &uattr->info.info_len))
5371 		return -EFAULT;
5372 
5373 	return 0;
5374 }
5375 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5376 static int bpf_btf_get_info_by_fd(struct file *file,
5377 				  struct btf *btf,
5378 				  const union bpf_attr *attr,
5379 				  union bpf_attr __user *uattr)
5380 {
5381 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5382 	u32 info_len = attr->info.info_len;
5383 	int err;
5384 
5385 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5386 	if (err)
5387 		return err;
5388 
5389 	return btf_get_info_by_fd(btf, attr, uattr);
5390 }
5391 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5392 static int bpf_link_get_info_by_fd(struct file *file,
5393 				  struct bpf_link *link,
5394 				  const union bpf_attr *attr,
5395 				  union bpf_attr __user *uattr)
5396 {
5397 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5398 	struct bpf_link_info info;
5399 	u32 info_len = attr->info.info_len;
5400 	int err;
5401 
5402 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5403 	if (err)
5404 		return err;
5405 	info_len = min_t(u32, sizeof(info), info_len);
5406 
5407 	memset(&info, 0, sizeof(info));
5408 	if (copy_from_user(&info, uinfo, info_len))
5409 		return -EFAULT;
5410 
5411 	info.type = link->type;
5412 	info.id = link->id;
5413 	if (link->prog)
5414 		info.prog_id = link->prog->aux->id;
5415 
5416 	if (link->ops->fill_link_info) {
5417 		err = link->ops->fill_link_info(link, &info);
5418 		if (err)
5419 			return err;
5420 	}
5421 
5422 	if (copy_to_user(uinfo, &info, info_len) ||
5423 	    put_user(info_len, &uattr->info.info_len))
5424 		return -EFAULT;
5425 
5426 	return 0;
5427 }
5428 
5429 
token_get_info_by_fd(struct file * file,struct bpf_token * token,const union bpf_attr * attr,union bpf_attr __user * uattr)5430 static int token_get_info_by_fd(struct file *file,
5431 				struct bpf_token *token,
5432 				const union bpf_attr *attr,
5433 				union bpf_attr __user *uattr)
5434 {
5435 	struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5436 	u32 info_len = attr->info.info_len;
5437 	int err;
5438 
5439 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5440 	if (err)
5441 		return err;
5442 	return bpf_token_get_info_by_fd(token, attr, uattr);
5443 }
5444 
5445 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5446 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5447 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5448 				  union bpf_attr __user *uattr)
5449 {
5450 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5451 		return -EINVAL;
5452 
5453 	CLASS(fd, f)(attr->info.bpf_fd);
5454 	if (fd_empty(f))
5455 		return -EBADFD;
5456 
5457 	if (fd_file(f)->f_op == &bpf_prog_fops)
5458 		return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5459 					      uattr);
5460 	else if (fd_file(f)->f_op == &bpf_map_fops)
5461 		return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5462 					     uattr);
5463 	else if (fd_file(f)->f_op == &btf_fops)
5464 		return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5465 	else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5466 		return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5467 					      attr, uattr);
5468 	else if (fd_file(f)->f_op == &bpf_token_fops)
5469 		return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5470 					    attr, uattr);
5471 	return -EINVAL;
5472 }
5473 
5474 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5475 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5476 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5477 {
5478 	struct bpf_token *token = NULL;
5479 
5480 	if (CHECK_ATTR(BPF_BTF_LOAD))
5481 		return -EINVAL;
5482 
5483 	if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5484 		return -EINVAL;
5485 
5486 	if (attr->btf_flags & BPF_F_TOKEN_FD) {
5487 		token = bpf_token_get_from_fd(attr->btf_token_fd);
5488 		if (IS_ERR(token))
5489 			return PTR_ERR(token);
5490 		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5491 			bpf_token_put(token);
5492 			token = NULL;
5493 		}
5494 	}
5495 
5496 	if (!bpf_token_capable(token, CAP_BPF)) {
5497 		bpf_token_put(token);
5498 		return -EPERM;
5499 	}
5500 
5501 	bpf_token_put(token);
5502 
5503 	return btf_new_fd(attr, uattr, uattr_size);
5504 }
5505 
5506 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5507 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5508 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5509 {
5510 	struct bpf_token *token = NULL;
5511 
5512 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5513 		return -EINVAL;
5514 
5515 	if (attr->open_flags & ~BPF_F_TOKEN_FD)
5516 		return -EINVAL;
5517 
5518 	if (attr->open_flags & BPF_F_TOKEN_FD) {
5519 		token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5520 		if (IS_ERR(token))
5521 			return PTR_ERR(token);
5522 		if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5523 			bpf_token_put(token);
5524 			token = NULL;
5525 		}
5526 	}
5527 
5528 	if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5529 		bpf_token_put(token);
5530 		return -EPERM;
5531 	}
5532 
5533 	bpf_token_put(token);
5534 
5535 	return btf_get_fd_by_id(attr->btf_id);
5536 }
5537 
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)5538 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5539 				    union bpf_attr __user *uattr,
5540 				    u32 prog_id, u32 fd_type,
5541 				    const char *buf, u64 probe_offset,
5542 				    u64 probe_addr)
5543 {
5544 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5545 	u32 len = buf ? strlen(buf) : 0, input_len;
5546 	int err = 0;
5547 
5548 	if (put_user(len, &uattr->task_fd_query.buf_len))
5549 		return -EFAULT;
5550 	input_len = attr->task_fd_query.buf_len;
5551 	if (input_len && ubuf) {
5552 		if (!len) {
5553 			/* nothing to copy, just make ubuf NULL terminated */
5554 			char zero = '\0';
5555 
5556 			if (put_user(zero, ubuf))
5557 				return -EFAULT;
5558 		} else {
5559 			err = bpf_copy_to_user(ubuf, buf, input_len, len);
5560 			if (err == -EFAULT)
5561 				return err;
5562 		}
5563 	}
5564 
5565 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5566 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5567 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5568 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5569 		return -EFAULT;
5570 
5571 	return err;
5572 }
5573 
5574 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5575 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5576 static int bpf_task_fd_query(const union bpf_attr *attr,
5577 			     union bpf_attr __user *uattr)
5578 {
5579 	pid_t pid = attr->task_fd_query.pid;
5580 	u32 fd = attr->task_fd_query.fd;
5581 	const struct perf_event *event;
5582 	struct task_struct *task;
5583 	struct file *file;
5584 	int err;
5585 
5586 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5587 		return -EINVAL;
5588 
5589 	if (!capable(CAP_SYS_ADMIN))
5590 		return -EPERM;
5591 
5592 	if (attr->task_fd_query.flags != 0)
5593 		return -EINVAL;
5594 
5595 	rcu_read_lock();
5596 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5597 	rcu_read_unlock();
5598 	if (!task)
5599 		return -ENOENT;
5600 
5601 	err = 0;
5602 	file = fget_task(task, fd);
5603 	put_task_struct(task);
5604 	if (!file)
5605 		return -EBADF;
5606 
5607 	if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5608 		struct bpf_link *link = file->private_data;
5609 
5610 		if (link->ops == &bpf_raw_tp_link_lops) {
5611 			struct bpf_raw_tp_link *raw_tp =
5612 				container_of(link, struct bpf_raw_tp_link, link);
5613 			struct bpf_raw_event_map *btp = raw_tp->btp;
5614 
5615 			err = bpf_task_fd_query_copy(attr, uattr,
5616 						     raw_tp->link.prog->aux->id,
5617 						     BPF_FD_TYPE_RAW_TRACEPOINT,
5618 						     btp->tp->name, 0, 0);
5619 			goto put_file;
5620 		}
5621 		goto out_not_supp;
5622 	}
5623 
5624 	event = perf_get_event(file);
5625 	if (!IS_ERR(event)) {
5626 		u64 probe_offset, probe_addr;
5627 		u32 prog_id, fd_type;
5628 		const char *buf;
5629 
5630 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5631 					      &buf, &probe_offset,
5632 					      &probe_addr, NULL);
5633 		if (!err)
5634 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5635 						     fd_type, buf,
5636 						     probe_offset,
5637 						     probe_addr);
5638 		goto put_file;
5639 	}
5640 
5641 out_not_supp:
5642 	err = -ENOTSUPP;
5643 put_file:
5644 	fput(file);
5645 	return err;
5646 }
5647 
5648 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5649 
5650 #define BPF_DO_BATCH(fn, ...)			\
5651 	do {					\
5652 		if (!fn) {			\
5653 			err = -ENOTSUPP;	\
5654 			goto err_put;		\
5655 		}				\
5656 		err = fn(__VA_ARGS__);		\
5657 	} while (0)
5658 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5659 static int bpf_map_do_batch(const union bpf_attr *attr,
5660 			    union bpf_attr __user *uattr,
5661 			    int cmd)
5662 {
5663 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
5664 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5665 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5666 	struct bpf_map *map;
5667 	int err;
5668 
5669 	if (CHECK_ATTR(BPF_MAP_BATCH))
5670 		return -EINVAL;
5671 
5672 	CLASS(fd, f)(attr->batch.map_fd);
5673 
5674 	map = __bpf_map_get(f);
5675 	if (IS_ERR(map))
5676 		return PTR_ERR(map);
5677 	if (has_write)
5678 		bpf_map_write_active_inc(map);
5679 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5680 		err = -EPERM;
5681 		goto err_put;
5682 	}
5683 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5684 		err = -EPERM;
5685 		goto err_put;
5686 	}
5687 
5688 	if (cmd == BPF_MAP_LOOKUP_BATCH)
5689 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5690 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5691 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5692 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5693 		BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5694 	else
5695 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5696 err_put:
5697 	if (has_write) {
5698 		maybe_wait_bpf_programs(map);
5699 		bpf_map_write_active_dec(map);
5700 	}
5701 	return err;
5702 }
5703 
5704 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5705 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5706 {
5707 	struct bpf_prog *prog;
5708 	int ret;
5709 
5710 	if (CHECK_ATTR(BPF_LINK_CREATE))
5711 		return -EINVAL;
5712 
5713 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5714 		return bpf_struct_ops_link_create(attr);
5715 
5716 	prog = bpf_prog_get(attr->link_create.prog_fd);
5717 	if (IS_ERR(prog))
5718 		return PTR_ERR(prog);
5719 
5720 	ret = bpf_prog_attach_check_attach_type(prog,
5721 						attr->link_create.attach_type);
5722 	if (ret)
5723 		goto out;
5724 
5725 	switch (prog->type) {
5726 	case BPF_PROG_TYPE_CGROUP_SKB:
5727 	case BPF_PROG_TYPE_CGROUP_SOCK:
5728 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5729 	case BPF_PROG_TYPE_SOCK_OPS:
5730 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5731 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5732 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5733 		ret = cgroup_bpf_link_attach(attr, prog);
5734 		break;
5735 	case BPF_PROG_TYPE_EXT:
5736 		ret = bpf_tracing_prog_attach(prog,
5737 					      attr->link_create.target_fd,
5738 					      attr->link_create.target_btf_id,
5739 					      attr->link_create.tracing.cookie,
5740 					      attr->link_create.attach_type);
5741 		break;
5742 	case BPF_PROG_TYPE_LSM:
5743 	case BPF_PROG_TYPE_TRACING:
5744 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5745 			ret = -EINVAL;
5746 			goto out;
5747 		}
5748 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5749 			ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie,
5750 						     attr->link_create.attach_type);
5751 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5752 			ret = bpf_iter_link_attach(attr, uattr, prog);
5753 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5754 			ret = cgroup_bpf_link_attach(attr, prog);
5755 		else
5756 			ret = bpf_tracing_prog_attach(prog,
5757 						      attr->link_create.target_fd,
5758 						      attr->link_create.target_btf_id,
5759 						      attr->link_create.tracing.cookie,
5760 						      attr->link_create.attach_type);
5761 		break;
5762 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5763 	case BPF_PROG_TYPE_SK_LOOKUP:
5764 		ret = netns_bpf_link_create(attr, prog);
5765 		break;
5766 	case BPF_PROG_TYPE_SK_MSG:
5767 	case BPF_PROG_TYPE_SK_SKB:
5768 		ret = sock_map_link_create(attr, prog);
5769 		break;
5770 #ifdef CONFIG_NET
5771 	case BPF_PROG_TYPE_XDP:
5772 		ret = bpf_xdp_link_attach(attr, prog);
5773 		break;
5774 	case BPF_PROG_TYPE_SCHED_CLS:
5775 		if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5776 		    attr->link_create.attach_type == BPF_TCX_EGRESS)
5777 			ret = tcx_link_attach(attr, prog);
5778 		else
5779 			ret = netkit_link_attach(attr, prog);
5780 		break;
5781 	case BPF_PROG_TYPE_NETFILTER:
5782 		ret = bpf_nf_link_attach(attr, prog);
5783 		break;
5784 #endif
5785 	case BPF_PROG_TYPE_PERF_EVENT:
5786 	case BPF_PROG_TYPE_TRACEPOINT:
5787 		ret = bpf_perf_link_attach(attr, prog);
5788 		break;
5789 	case BPF_PROG_TYPE_KPROBE:
5790 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5791 			ret = bpf_perf_link_attach(attr, prog);
5792 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5793 			 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5794 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5795 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5796 			 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5797 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5798 		break;
5799 	default:
5800 		ret = -EINVAL;
5801 	}
5802 
5803 out:
5804 	if (ret < 0)
5805 		bpf_prog_put(prog);
5806 	return ret;
5807 }
5808 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5809 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5810 {
5811 	struct bpf_map *new_map, *old_map = NULL;
5812 	int ret;
5813 
5814 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5815 	if (IS_ERR(new_map))
5816 		return PTR_ERR(new_map);
5817 
5818 	if (attr->link_update.flags & BPF_F_REPLACE) {
5819 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5820 		if (IS_ERR(old_map)) {
5821 			ret = PTR_ERR(old_map);
5822 			goto out_put;
5823 		}
5824 	} else if (attr->link_update.old_map_fd) {
5825 		ret = -EINVAL;
5826 		goto out_put;
5827 	}
5828 
5829 	ret = link->ops->update_map(link, new_map, old_map);
5830 
5831 	if (old_map)
5832 		bpf_map_put(old_map);
5833 out_put:
5834 	bpf_map_put(new_map);
5835 	return ret;
5836 }
5837 
5838 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5839 
link_update(union bpf_attr * attr)5840 static int link_update(union bpf_attr *attr)
5841 {
5842 	struct bpf_prog *old_prog = NULL, *new_prog;
5843 	struct bpf_link *link;
5844 	u32 flags;
5845 	int ret;
5846 
5847 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5848 		return -EINVAL;
5849 
5850 	flags = attr->link_update.flags;
5851 	if (flags & ~BPF_F_REPLACE)
5852 		return -EINVAL;
5853 
5854 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5855 	if (IS_ERR(link))
5856 		return PTR_ERR(link);
5857 
5858 	if (link->ops->update_map) {
5859 		ret = link_update_map(link, attr);
5860 		goto out_put_link;
5861 	}
5862 
5863 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5864 	if (IS_ERR(new_prog)) {
5865 		ret = PTR_ERR(new_prog);
5866 		goto out_put_link;
5867 	}
5868 
5869 	if (flags & BPF_F_REPLACE) {
5870 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5871 		if (IS_ERR(old_prog)) {
5872 			ret = PTR_ERR(old_prog);
5873 			old_prog = NULL;
5874 			goto out_put_progs;
5875 		}
5876 	} else if (attr->link_update.old_prog_fd) {
5877 		ret = -EINVAL;
5878 		goto out_put_progs;
5879 	}
5880 
5881 	if (link->ops->update_prog)
5882 		ret = link->ops->update_prog(link, new_prog, old_prog);
5883 	else
5884 		ret = -EINVAL;
5885 
5886 out_put_progs:
5887 	if (old_prog)
5888 		bpf_prog_put(old_prog);
5889 	if (ret)
5890 		bpf_prog_put(new_prog);
5891 out_put_link:
5892 	bpf_link_put_direct(link);
5893 	return ret;
5894 }
5895 
5896 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5897 
link_detach(union bpf_attr * attr)5898 static int link_detach(union bpf_attr *attr)
5899 {
5900 	struct bpf_link *link;
5901 	int ret;
5902 
5903 	if (CHECK_ATTR(BPF_LINK_DETACH))
5904 		return -EINVAL;
5905 
5906 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5907 	if (IS_ERR(link))
5908 		return PTR_ERR(link);
5909 
5910 	if (link->ops->detach)
5911 		ret = link->ops->detach(link);
5912 	else
5913 		ret = -EOPNOTSUPP;
5914 
5915 	bpf_link_put_direct(link);
5916 	return ret;
5917 }
5918 
bpf_link_inc_not_zero(struct bpf_link * link)5919 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5920 {
5921 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5922 }
5923 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5924 
bpf_link_by_id(u32 id)5925 struct bpf_link *bpf_link_by_id(u32 id)
5926 {
5927 	struct bpf_link *link;
5928 
5929 	if (!id)
5930 		return ERR_PTR(-ENOENT);
5931 
5932 	spin_lock_bh(&link_idr_lock);
5933 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5934 	link = idr_find(&link_idr, id);
5935 	if (link) {
5936 		if (link->id)
5937 			link = bpf_link_inc_not_zero(link);
5938 		else
5939 			link = ERR_PTR(-EAGAIN);
5940 	} else {
5941 		link = ERR_PTR(-ENOENT);
5942 	}
5943 	spin_unlock_bh(&link_idr_lock);
5944 	return link;
5945 }
5946 
bpf_link_get_curr_or_next(u32 * id)5947 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5948 {
5949 	struct bpf_link *link;
5950 
5951 	spin_lock_bh(&link_idr_lock);
5952 again:
5953 	link = idr_get_next(&link_idr, id);
5954 	if (link) {
5955 		link = bpf_link_inc_not_zero(link);
5956 		if (IS_ERR(link)) {
5957 			(*id)++;
5958 			goto again;
5959 		}
5960 	}
5961 	spin_unlock_bh(&link_idr_lock);
5962 
5963 	return link;
5964 }
5965 
5966 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5967 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5968 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5969 {
5970 	struct bpf_link *link;
5971 	u32 id = attr->link_id;
5972 	int fd;
5973 
5974 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5975 		return -EINVAL;
5976 
5977 	if (!capable(CAP_SYS_ADMIN))
5978 		return -EPERM;
5979 
5980 	link = bpf_link_by_id(id);
5981 	if (IS_ERR(link))
5982 		return PTR_ERR(link);
5983 
5984 	fd = bpf_link_new_fd(link);
5985 	if (fd < 0)
5986 		bpf_link_put_direct(link);
5987 
5988 	return fd;
5989 }
5990 
5991 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5992 
bpf_stats_release(struct inode * inode,struct file * file)5993 static int bpf_stats_release(struct inode *inode, struct file *file)
5994 {
5995 	mutex_lock(&bpf_stats_enabled_mutex);
5996 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5997 	mutex_unlock(&bpf_stats_enabled_mutex);
5998 	return 0;
5999 }
6000 
6001 static const struct file_operations bpf_stats_fops = {
6002 	.release = bpf_stats_release,
6003 };
6004 
bpf_enable_runtime_stats(void)6005 static int bpf_enable_runtime_stats(void)
6006 {
6007 	int fd;
6008 
6009 	mutex_lock(&bpf_stats_enabled_mutex);
6010 
6011 	/* Set a very high limit to avoid overflow */
6012 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
6013 		mutex_unlock(&bpf_stats_enabled_mutex);
6014 		return -EBUSY;
6015 	}
6016 
6017 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
6018 	if (fd >= 0)
6019 		static_key_slow_inc(&bpf_stats_enabled_key.key);
6020 
6021 	mutex_unlock(&bpf_stats_enabled_mutex);
6022 	return fd;
6023 }
6024 
6025 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
6026 
bpf_enable_stats(union bpf_attr * attr)6027 static int bpf_enable_stats(union bpf_attr *attr)
6028 {
6029 
6030 	if (CHECK_ATTR(BPF_ENABLE_STATS))
6031 		return -EINVAL;
6032 
6033 	if (!capable(CAP_SYS_ADMIN))
6034 		return -EPERM;
6035 
6036 	switch (attr->enable_stats.type) {
6037 	case BPF_STATS_RUN_TIME:
6038 		return bpf_enable_runtime_stats();
6039 	default:
6040 		break;
6041 	}
6042 	return -EINVAL;
6043 }
6044 
6045 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
6046 
bpf_iter_create(union bpf_attr * attr)6047 static int bpf_iter_create(union bpf_attr *attr)
6048 {
6049 	struct bpf_link *link;
6050 	int err;
6051 
6052 	if (CHECK_ATTR(BPF_ITER_CREATE))
6053 		return -EINVAL;
6054 
6055 	if (attr->iter_create.flags)
6056 		return -EINVAL;
6057 
6058 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
6059 	if (IS_ERR(link))
6060 		return PTR_ERR(link);
6061 
6062 	err = bpf_iter_new_fd(link);
6063 	bpf_link_put_direct(link);
6064 
6065 	return err;
6066 }
6067 
6068 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
6069 
bpf_prog_bind_map(union bpf_attr * attr)6070 static int bpf_prog_bind_map(union bpf_attr *attr)
6071 {
6072 	struct bpf_prog *prog;
6073 	struct bpf_map *map;
6074 	struct bpf_map **used_maps_old, **used_maps_new;
6075 	int i, ret = 0;
6076 
6077 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
6078 		return -EINVAL;
6079 
6080 	if (attr->prog_bind_map.flags)
6081 		return -EINVAL;
6082 
6083 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
6084 	if (IS_ERR(prog))
6085 		return PTR_ERR(prog);
6086 
6087 	map = bpf_map_get(attr->prog_bind_map.map_fd);
6088 	if (IS_ERR(map)) {
6089 		ret = PTR_ERR(map);
6090 		goto out_prog_put;
6091 	}
6092 
6093 	mutex_lock(&prog->aux->used_maps_mutex);
6094 
6095 	used_maps_old = prog->aux->used_maps;
6096 
6097 	for (i = 0; i < prog->aux->used_map_cnt; i++)
6098 		if (used_maps_old[i] == map) {
6099 			bpf_map_put(map);
6100 			goto out_unlock;
6101 		}
6102 
6103 	used_maps_new = kmalloc_objs(used_maps_new[0],
6104 				     prog->aux->used_map_cnt + 1);
6105 	if (!used_maps_new) {
6106 		ret = -ENOMEM;
6107 		goto out_unlock;
6108 	}
6109 
6110 	/* The bpf program will not access the bpf map, but for the sake of
6111 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
6112 	 */
6113 	if (prog->sleepable)
6114 		atomic64_inc(&map->sleepable_refcnt);
6115 	memcpy(used_maps_new, used_maps_old,
6116 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
6117 	used_maps_new[prog->aux->used_map_cnt] = map;
6118 
6119 	prog->aux->used_map_cnt++;
6120 	prog->aux->used_maps = used_maps_new;
6121 
6122 	kfree(used_maps_old);
6123 
6124 out_unlock:
6125 	mutex_unlock(&prog->aux->used_maps_mutex);
6126 
6127 	if (ret)
6128 		bpf_map_put(map);
6129 out_prog_put:
6130 	bpf_prog_put(prog);
6131 	return ret;
6132 }
6133 
6134 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
6135 
token_create(union bpf_attr * attr)6136 static int token_create(union bpf_attr *attr)
6137 {
6138 	if (CHECK_ATTR(BPF_TOKEN_CREATE))
6139 		return -EINVAL;
6140 
6141 	/* no flags are supported yet */
6142 	if (attr->token_create.flags)
6143 		return -EINVAL;
6144 
6145 	return bpf_token_create(attr);
6146 }
6147 
6148 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd
6149 
prog_stream_read(union bpf_attr * attr)6150 static int prog_stream_read(union bpf_attr *attr)
6151 {
6152 	char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf);
6153 	u32 len = attr->prog_stream_read.stream_buf_len;
6154 	struct bpf_prog *prog;
6155 	int ret;
6156 
6157 	if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD))
6158 		return -EINVAL;
6159 
6160 	prog = bpf_prog_get(attr->prog_stream_read.prog_fd);
6161 	if (IS_ERR(prog))
6162 		return PTR_ERR(prog);
6163 
6164 	ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len);
6165 	bpf_prog_put(prog);
6166 
6167 	return ret;
6168 }
6169 
6170 #define BPF_PROG_ASSOC_STRUCT_OPS_LAST_FIELD prog_assoc_struct_ops.prog_fd
6171 
prog_assoc_struct_ops(union bpf_attr * attr)6172 static int prog_assoc_struct_ops(union bpf_attr *attr)
6173 {
6174 	struct bpf_prog *prog;
6175 	struct bpf_map *map;
6176 	int ret;
6177 
6178 	if (CHECK_ATTR(BPF_PROG_ASSOC_STRUCT_OPS))
6179 		return -EINVAL;
6180 
6181 	if (attr->prog_assoc_struct_ops.flags)
6182 		return -EINVAL;
6183 
6184 	prog = bpf_prog_get(attr->prog_assoc_struct_ops.prog_fd);
6185 	if (IS_ERR(prog))
6186 		return PTR_ERR(prog);
6187 
6188 	if (prog->type == BPF_PROG_TYPE_STRUCT_OPS) {
6189 		ret = -EINVAL;
6190 		goto put_prog;
6191 	}
6192 
6193 	map = bpf_map_get(attr->prog_assoc_struct_ops.map_fd);
6194 	if (IS_ERR(map)) {
6195 		ret = PTR_ERR(map);
6196 		goto put_prog;
6197 	}
6198 
6199 	if (map->map_type != BPF_MAP_TYPE_STRUCT_OPS) {
6200 		ret = -EINVAL;
6201 		goto put_map;
6202 	}
6203 
6204 	ret = bpf_prog_assoc_struct_ops(prog, map);
6205 
6206 put_map:
6207 	bpf_map_put(map);
6208 put_prog:
6209 	bpf_prog_put(prog);
6210 	return ret;
6211 }
6212 
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)6213 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
6214 {
6215 	union bpf_attr attr;
6216 	int err;
6217 
6218 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
6219 	if (err)
6220 		return err;
6221 	size = min_t(u32, size, sizeof(attr));
6222 
6223 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
6224 	memset(&attr, 0, sizeof(attr));
6225 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
6226 		return -EFAULT;
6227 
6228 	err = security_bpf(cmd, &attr, size, uattr.is_kernel);
6229 	if (err < 0)
6230 		return err;
6231 
6232 	switch (cmd) {
6233 	case BPF_MAP_CREATE:
6234 		err = map_create(&attr, uattr);
6235 		break;
6236 	case BPF_MAP_LOOKUP_ELEM:
6237 		err = map_lookup_elem(&attr);
6238 		break;
6239 	case BPF_MAP_UPDATE_ELEM:
6240 		err = map_update_elem(&attr, uattr);
6241 		break;
6242 	case BPF_MAP_DELETE_ELEM:
6243 		err = map_delete_elem(&attr, uattr);
6244 		break;
6245 	case BPF_MAP_GET_NEXT_KEY:
6246 		err = map_get_next_key(&attr);
6247 		break;
6248 	case BPF_MAP_FREEZE:
6249 		err = map_freeze(&attr);
6250 		break;
6251 	case BPF_PROG_LOAD:
6252 		err = bpf_prog_load(&attr, uattr, size);
6253 		break;
6254 	case BPF_OBJ_PIN:
6255 		err = bpf_obj_pin(&attr);
6256 		break;
6257 	case BPF_OBJ_GET:
6258 		err = bpf_obj_get(&attr);
6259 		break;
6260 	case BPF_PROG_ATTACH:
6261 		err = bpf_prog_attach(&attr);
6262 		break;
6263 	case BPF_PROG_DETACH:
6264 		err = bpf_prog_detach(&attr);
6265 		break;
6266 	case BPF_PROG_QUERY:
6267 		err = bpf_prog_query(&attr, uattr.user);
6268 		break;
6269 	case BPF_PROG_TEST_RUN:
6270 		err = bpf_prog_test_run(&attr, uattr.user);
6271 		break;
6272 	case BPF_PROG_GET_NEXT_ID:
6273 		err = bpf_obj_get_next_id(&attr, uattr.user,
6274 					  &prog_idr, &prog_idr_lock);
6275 		break;
6276 	case BPF_MAP_GET_NEXT_ID:
6277 		err = bpf_obj_get_next_id(&attr, uattr.user,
6278 					  &map_idr, &map_idr_lock);
6279 		break;
6280 	case BPF_BTF_GET_NEXT_ID:
6281 		err = bpf_obj_get_next_id(&attr, uattr.user,
6282 					  &btf_idr, &btf_idr_lock);
6283 		break;
6284 	case BPF_PROG_GET_FD_BY_ID:
6285 		err = bpf_prog_get_fd_by_id(&attr);
6286 		break;
6287 	case BPF_MAP_GET_FD_BY_ID:
6288 		err = bpf_map_get_fd_by_id(&attr);
6289 		break;
6290 	case BPF_OBJ_GET_INFO_BY_FD:
6291 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
6292 		break;
6293 	case BPF_RAW_TRACEPOINT_OPEN:
6294 		err = bpf_raw_tracepoint_open(&attr);
6295 		break;
6296 	case BPF_BTF_LOAD:
6297 		err = bpf_btf_load(&attr, uattr, size);
6298 		break;
6299 	case BPF_BTF_GET_FD_BY_ID:
6300 		err = bpf_btf_get_fd_by_id(&attr);
6301 		break;
6302 	case BPF_TASK_FD_QUERY:
6303 		err = bpf_task_fd_query(&attr, uattr.user);
6304 		break;
6305 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
6306 		err = map_lookup_and_delete_elem(&attr);
6307 		break;
6308 	case BPF_MAP_LOOKUP_BATCH:
6309 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
6310 		break;
6311 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
6312 		err = bpf_map_do_batch(&attr, uattr.user,
6313 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
6314 		break;
6315 	case BPF_MAP_UPDATE_BATCH:
6316 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
6317 		break;
6318 	case BPF_MAP_DELETE_BATCH:
6319 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
6320 		break;
6321 	case BPF_LINK_CREATE:
6322 		err = link_create(&attr, uattr);
6323 		break;
6324 	case BPF_LINK_UPDATE:
6325 		err = link_update(&attr);
6326 		break;
6327 	case BPF_LINK_GET_FD_BY_ID:
6328 		err = bpf_link_get_fd_by_id(&attr);
6329 		break;
6330 	case BPF_LINK_GET_NEXT_ID:
6331 		err = bpf_obj_get_next_id(&attr, uattr.user,
6332 					  &link_idr, &link_idr_lock);
6333 		break;
6334 	case BPF_ENABLE_STATS:
6335 		err = bpf_enable_stats(&attr);
6336 		break;
6337 	case BPF_ITER_CREATE:
6338 		err = bpf_iter_create(&attr);
6339 		break;
6340 	case BPF_LINK_DETACH:
6341 		err = link_detach(&attr);
6342 		break;
6343 	case BPF_PROG_BIND_MAP:
6344 		err = bpf_prog_bind_map(&attr);
6345 		break;
6346 	case BPF_TOKEN_CREATE:
6347 		err = token_create(&attr);
6348 		break;
6349 	case BPF_PROG_STREAM_READ_BY_FD:
6350 		err = prog_stream_read(&attr);
6351 		break;
6352 	case BPF_PROG_ASSOC_STRUCT_OPS:
6353 		err = prog_assoc_struct_ops(&attr);
6354 		break;
6355 	default:
6356 		err = -EINVAL;
6357 		break;
6358 	}
6359 
6360 	return err;
6361 }
6362 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)6363 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
6364 {
6365 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
6366 }
6367 
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)6368 static bool syscall_prog_is_valid_access(int off, int size,
6369 					 enum bpf_access_type type,
6370 					 const struct bpf_prog *prog,
6371 					 struct bpf_insn_access_aux *info)
6372 {
6373 	if (off < 0 || off >= U16_MAX)
6374 		return false;
6375 	/* No alignment requirements for syscall ctx accesses. */
6376 	return true;
6377 }
6378 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)6379 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
6380 {
6381 	switch (cmd) {
6382 	case BPF_MAP_CREATE:
6383 	case BPF_MAP_DELETE_ELEM:
6384 	case BPF_MAP_UPDATE_ELEM:
6385 	case BPF_MAP_FREEZE:
6386 	case BPF_MAP_GET_FD_BY_ID:
6387 	case BPF_PROG_LOAD:
6388 	case BPF_BTF_LOAD:
6389 	case BPF_LINK_CREATE:
6390 	case BPF_RAW_TRACEPOINT_OPEN:
6391 		break;
6392 	default:
6393 		return -EINVAL;
6394 	}
6395 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
6396 }
6397 
6398 
6399 /* To shut up -Wmissing-prototypes.
6400  * This function is used by the kernel light skeleton
6401  * to load bpf programs when modules are loaded or during kernel boot.
6402  * See tools/lib/bpf/skel_internal.h
6403  */
6404 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
6405 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)6406 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
6407 {
6408 	struct bpf_prog * __maybe_unused prog;
6409 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
6410 
6411 	switch (cmd) {
6412 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
6413 	case BPF_PROG_TEST_RUN:
6414 		if (attr->test.data_in || attr->test.data_out ||
6415 		    attr->test.ctx_out || attr->test.duration ||
6416 		    attr->test.repeat || attr->test.flags)
6417 			return -EINVAL;
6418 
6419 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
6420 		if (IS_ERR(prog))
6421 			return PTR_ERR(prog);
6422 
6423 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6424 		    attr->test.ctx_size_in > U16_MAX) {
6425 			bpf_prog_put(prog);
6426 			return -EINVAL;
6427 		}
6428 
6429 		run_ctx.bpf_cookie = 0;
6430 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6431 			/* recursion detected */
6432 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6433 			bpf_prog_put(prog);
6434 			return -EBUSY;
6435 		}
6436 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6437 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6438 						&run_ctx);
6439 		bpf_prog_put(prog);
6440 		return 0;
6441 #endif
6442 	default:
6443 		return ____bpf_sys_bpf(cmd, attr, size);
6444 	}
6445 }
6446 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL");
6447 
6448 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6449 	.func		= bpf_sys_bpf,
6450 	.gpl_only	= false,
6451 	.ret_type	= RET_INTEGER,
6452 	.arg1_type	= ARG_ANYTHING,
6453 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
6454 	.arg3_type	= ARG_CONST_SIZE,
6455 };
6456 
6457 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6458 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6459 {
6460 	return bpf_base_func_proto(func_id, prog);
6461 }
6462 
BPF_CALL_1(bpf_sys_close,u32,fd)6463 BPF_CALL_1(bpf_sys_close, u32, fd)
6464 {
6465 	/* When bpf program calls this helper there should not be
6466 	 * an fdget() without matching completed fdput().
6467 	 * This helper is allowed in the following callchain only:
6468 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6469 	 */
6470 	return close_fd(fd);
6471 }
6472 
6473 static const struct bpf_func_proto bpf_sys_close_proto = {
6474 	.func		= bpf_sys_close,
6475 	.gpl_only	= false,
6476 	.ret_type	= RET_INTEGER,
6477 	.arg1_type	= ARG_ANYTHING,
6478 };
6479 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6480 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6481 {
6482 	*res = 0;
6483 	if (flags)
6484 		return -EINVAL;
6485 
6486 	if (name_sz <= 1 || name[name_sz - 1])
6487 		return -EINVAL;
6488 
6489 	if (!bpf_dump_raw_ok(current_cred()))
6490 		return -EPERM;
6491 
6492 	*res = kallsyms_lookup_name(name);
6493 	return *res ? 0 : -ENOENT;
6494 }
6495 
6496 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6497 	.func		= bpf_kallsyms_lookup_name,
6498 	.gpl_only	= false,
6499 	.ret_type	= RET_INTEGER,
6500 	.arg1_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
6501 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
6502 	.arg3_type	= ARG_ANYTHING,
6503 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6504 	.arg4_size	= sizeof(u64),
6505 };
6506 
6507 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6508 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6509 {
6510 	switch (func_id) {
6511 	case BPF_FUNC_sys_bpf:
6512 		return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6513 		       ? NULL : &bpf_sys_bpf_proto;
6514 	case BPF_FUNC_btf_find_by_name_kind:
6515 		return &bpf_btf_find_by_name_kind_proto;
6516 	case BPF_FUNC_sys_close:
6517 		return &bpf_sys_close_proto;
6518 	case BPF_FUNC_kallsyms_lookup_name:
6519 		return &bpf_kallsyms_lookup_name_proto;
6520 	default:
6521 		return tracing_prog_func_proto(func_id, prog);
6522 	}
6523 }
6524 
6525 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6526 	.get_func_proto  = syscall_prog_func_proto,
6527 	.is_valid_access = syscall_prog_is_valid_access,
6528 };
6529 
6530 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6531 	.test_run = bpf_prog_test_run_syscall,
6532 };
6533 
6534 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6535 static int bpf_stats_handler(const struct ctl_table *table, int write,
6536 			     void *buffer, size_t *lenp, loff_t *ppos)
6537 {
6538 	struct static_key *key = (struct static_key *)table->data;
6539 	static int saved_val;
6540 	int val, ret;
6541 	struct ctl_table tmp = {
6542 		.data   = &val,
6543 		.maxlen = sizeof(val),
6544 		.mode   = table->mode,
6545 		.extra1 = SYSCTL_ZERO,
6546 		.extra2 = SYSCTL_ONE,
6547 	};
6548 
6549 	if (write && !capable(CAP_SYS_ADMIN))
6550 		return -EPERM;
6551 
6552 	mutex_lock(&bpf_stats_enabled_mutex);
6553 	val = saved_val;
6554 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6555 	if (write && !ret && val != saved_val) {
6556 		if (val)
6557 			static_key_slow_inc(key);
6558 		else
6559 			static_key_slow_dec(key);
6560 		saved_val = val;
6561 	}
6562 	mutex_unlock(&bpf_stats_enabled_mutex);
6563 	return ret;
6564 }
6565 
unpriv_ebpf_notify(int new_state)6566 void __weak unpriv_ebpf_notify(int new_state)
6567 {
6568 }
6569 
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6570 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6571 			      void *buffer, size_t *lenp, loff_t *ppos)
6572 {
6573 	int ret, unpriv_enable = *(int *)table->data;
6574 	bool locked_state = unpriv_enable == 1;
6575 	struct ctl_table tmp = *table;
6576 
6577 	if (write && !capable(CAP_SYS_ADMIN))
6578 		return -EPERM;
6579 
6580 	tmp.data = &unpriv_enable;
6581 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6582 	if (write && !ret) {
6583 		if (locked_state && unpriv_enable != 1)
6584 			return -EPERM;
6585 		*(int *)table->data = unpriv_enable;
6586 	}
6587 
6588 	if (write)
6589 		unpriv_ebpf_notify(unpriv_enable);
6590 
6591 	return ret;
6592 }
6593 
6594 static const struct ctl_table bpf_syscall_table[] = {
6595 	{
6596 		.procname	= "unprivileged_bpf_disabled",
6597 		.data		= &sysctl_unprivileged_bpf_disabled,
6598 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
6599 		.mode		= 0644,
6600 		.proc_handler	= bpf_unpriv_handler,
6601 		.extra1		= SYSCTL_ZERO,
6602 		.extra2		= SYSCTL_TWO,
6603 	},
6604 	{
6605 		.procname	= "bpf_stats_enabled",
6606 		.data		= &bpf_stats_enabled_key.key,
6607 		.mode		= 0644,
6608 		.proc_handler	= bpf_stats_handler,
6609 	},
6610 };
6611 
bpf_syscall_sysctl_init(void)6612 static int __init bpf_syscall_sysctl_init(void)
6613 {
6614 	register_sysctl_init("kernel", bpf_syscall_table);
6615 	return 0;
6616 }
6617 late_initcall(bpf_syscall_sysctl_init);
6618 #endif /* CONFIG_SYSCTL */
6619