1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3  */
4 #include <linux/bpf.h>
5 #include <linux/bpf_trace.h>
6 #include <linux/bpf_lirc.h>
7 #include <linux/bpf_verifier.h>
8 #include <linux/btf.h>
9 #include <linux/syscalls.h>
10 #include <linux/slab.h>
11 #include <linux/sched/signal.h>
12 #include <linux/vmalloc.h>
13 #include <linux/mmzone.h>
14 #include <linux/anon_inodes.h>
15 #include <linux/fdtable.h>
16 #include <linux/file.h>
17 #include <linux/fs.h>
18 #include <linux/license.h>
19 #include <linux/filter.h>
20 #include <linux/kernel.h>
21 #include <linux/idr.h>
22 #include <linux/cred.h>
23 #include <linux/timekeeping.h>
24 #include <linux/ctype.h>
25 #include <linux/nospec.h>
26 #include <linux/audit.h>
27 #include <uapi/linux/btf.h>
28 #include <linux/pgtable.h>
29 #include <linux/bpf_lsm.h>
30 #include <linux/poll.h>
31 #include <linux/bpf-netns.h>
32 #include <linux/rcupdate_trace.h>
33 #include <linux/memcontrol.h>
34 
35 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
36 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
37 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
38 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
39 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
40 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
41 			IS_FD_HASH(map))
42 
43 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
44 
45 DEFINE_PER_CPU(int, bpf_prog_active);
46 static DEFINE_IDR(prog_idr);
47 static DEFINE_SPINLOCK(prog_idr_lock);
48 static DEFINE_IDR(map_idr);
49 static DEFINE_SPINLOCK(map_idr_lock);
50 static DEFINE_IDR(link_idr);
51 static DEFINE_SPINLOCK(link_idr_lock);
52 
53 int sysctl_unprivileged_bpf_disabled __read_mostly =
54 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
55 
56 static const struct bpf_map_ops * const bpf_map_types[] = {
57 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
58 #define BPF_MAP_TYPE(_id, _ops) \
59 	[_id] = &_ops,
60 #define BPF_LINK_TYPE(_id, _name)
61 #include <linux/bpf_types.h>
62 #undef BPF_PROG_TYPE
63 #undef BPF_MAP_TYPE
64 #undef BPF_LINK_TYPE
65 };
66 
67 /*
68  * If we're handed a bigger struct than we know of, ensure all the unknown bits
69  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
70  * we don't know about yet.
71  *
72  * There is a ToCToU between this function call and the following
73  * copy_from_user() call. However, this is not a concern since this function is
74  * meant to be a future-proofing of bits.
75  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)76 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
77 			     size_t expected_size,
78 			     size_t actual_size)
79 {
80 	int res;
81 
82 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
83 		return -E2BIG;
84 
85 	if (actual_size <= expected_size)
86 		return 0;
87 
88 	if (uaddr.is_kernel)
89 		res = memchr_inv(uaddr.kernel + expected_size, 0,
90 				 actual_size - expected_size) == NULL;
91 	else
92 		res = check_zeroed_user(uaddr.user + expected_size,
93 					actual_size - expected_size);
94 	if (res < 0)
95 		return res;
96 	return res ? 0 : -E2BIG;
97 }
98 
99 const struct bpf_map_ops bpf_map_offload_ops = {
100 	.map_meta_equal = bpf_map_meta_equal,
101 	.map_alloc = bpf_map_offload_map_alloc,
102 	.map_free = bpf_map_offload_map_free,
103 	.map_check_btf = map_check_no_btf,
104 };
105 
find_and_alloc_map(union bpf_attr * attr)106 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
107 {
108 	const struct bpf_map_ops *ops;
109 	u32 type = attr->map_type;
110 	struct bpf_map *map;
111 	int err;
112 
113 	if (type >= ARRAY_SIZE(bpf_map_types))
114 		return ERR_PTR(-EINVAL);
115 	type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
116 	ops = bpf_map_types[type];
117 	if (!ops)
118 		return ERR_PTR(-EINVAL);
119 
120 	if (ops->map_alloc_check) {
121 		err = ops->map_alloc_check(attr);
122 		if (err)
123 			return ERR_PTR(err);
124 	}
125 	if (attr->map_ifindex)
126 		ops = &bpf_map_offload_ops;
127 	map = ops->map_alloc(attr);
128 	if (IS_ERR(map))
129 		return map;
130 	map->ops = ops;
131 	map->map_type = type;
132 	return map;
133 }
134 
bpf_map_value_size(const struct bpf_map * map)135 static u32 bpf_map_value_size(const struct bpf_map *map)
136 {
137 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
138 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
139 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
140 	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
141 		return round_up(map->value_size, 8) * num_possible_cpus();
142 	else if (IS_FD_MAP(map))
143 		return sizeof(u32);
144 	else
145 		return  map->value_size;
146 }
147 
maybe_wait_bpf_programs(struct bpf_map * map)148 static void maybe_wait_bpf_programs(struct bpf_map *map)
149 {
150 	/* Wait for any running BPF programs to complete so that
151 	 * userspace, when we return to it, knows that all programs
152 	 * that could be running use the new map value.
153 	 */
154 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
155 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
156 		synchronize_rcu();
157 }
158 
bpf_map_update_value(struct bpf_map * map,struct fd f,void * key,void * value,__u64 flags)159 static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
160 				void *value, __u64 flags)
161 {
162 	int err;
163 
164 	/* Need to create a kthread, thus must support schedule */
165 	if (bpf_map_is_dev_bound(map)) {
166 		return bpf_map_offload_update_elem(map, key, value, flags);
167 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
168 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
169 		return map->ops->map_update_elem(map, key, value, flags);
170 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
171 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
172 		return sock_map_update_elem_sys(map, key, value, flags);
173 	} else if (IS_FD_PROG_ARRAY(map)) {
174 		return bpf_fd_array_map_update_elem(map, f.file, key, value,
175 						    flags);
176 	}
177 
178 	bpf_disable_instrumentation();
179 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
180 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
181 		err = bpf_percpu_hash_update(map, key, value, flags);
182 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
183 		err = bpf_percpu_array_update(map, key, value, flags);
184 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
185 		err = bpf_percpu_cgroup_storage_update(map, key, value,
186 						       flags);
187 	} else if (IS_FD_ARRAY(map)) {
188 		rcu_read_lock();
189 		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
190 						   flags);
191 		rcu_read_unlock();
192 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
193 		rcu_read_lock();
194 		err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
195 						  flags);
196 		rcu_read_unlock();
197 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
198 		/* rcu_read_lock() is not needed */
199 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
200 							 flags);
201 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
202 		   map->map_type == BPF_MAP_TYPE_STACK) {
203 		err = map->ops->map_push_elem(map, value, flags);
204 	} else {
205 		rcu_read_lock();
206 		err = map->ops->map_update_elem(map, key, value, flags);
207 		rcu_read_unlock();
208 	}
209 	bpf_enable_instrumentation();
210 	maybe_wait_bpf_programs(map);
211 
212 	return err;
213 }
214 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)215 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
216 			      __u64 flags)
217 {
218 	void *ptr;
219 	int err;
220 
221 	if (bpf_map_is_dev_bound(map))
222 		return bpf_map_offload_lookup_elem(map, key, value);
223 
224 	bpf_disable_instrumentation();
225 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
226 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
227 		err = bpf_percpu_hash_copy(map, key, value);
228 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
229 		err = bpf_percpu_array_copy(map, key, value);
230 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
231 		err = bpf_percpu_cgroup_storage_copy(map, key, value);
232 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
233 		err = bpf_stackmap_copy(map, key, value);
234 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
235 		err = bpf_fd_array_map_lookup_elem(map, key, value);
236 	} else if (IS_FD_HASH(map)) {
237 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
238 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
239 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
240 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
241 		   map->map_type == BPF_MAP_TYPE_STACK) {
242 		err = map->ops->map_peek_elem(map, value);
243 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
244 		/* struct_ops map requires directly updating "value" */
245 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
246 	} else {
247 		rcu_read_lock();
248 		if (map->ops->map_lookup_elem_sys_only)
249 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
250 		else
251 			ptr = map->ops->map_lookup_elem(map, key);
252 		if (IS_ERR(ptr)) {
253 			err = PTR_ERR(ptr);
254 		} else if (!ptr) {
255 			err = -ENOENT;
256 		} else {
257 			err = 0;
258 			if (flags & BPF_F_LOCK)
259 				/* lock 'ptr' and copy everything but lock */
260 				copy_map_value_locked(map, value, ptr, true);
261 			else
262 				copy_map_value(map, value, ptr);
263 			/* mask lock and timer, since value wasn't zero inited */
264 			check_and_init_map_value(map, value);
265 		}
266 		rcu_read_unlock();
267 	}
268 
269 	bpf_enable_instrumentation();
270 	maybe_wait_bpf_programs(map);
271 
272 	return err;
273 }
274 
275 /* Please, do not use this function outside from the map creation path
276  * (e.g. in map update path) without taking care of setting the active
277  * memory cgroup (see at bpf_map_kmalloc_node() for example).
278  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)279 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
280 {
281 	/* We really just want to fail instead of triggering OOM killer
282 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
283 	 * which is used for lower order allocation requests.
284 	 *
285 	 * It has been observed that higher order allocation requests done by
286 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
287 	 * to reclaim memory from the page cache, thus we set
288 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
289 	 */
290 
291 	const gfp_t gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_ACCOUNT;
292 	unsigned int flags = 0;
293 	unsigned long align = 1;
294 	void *area;
295 
296 	if (size >= SIZE_MAX)
297 		return NULL;
298 
299 	/* kmalloc()'ed memory can't be mmap()'ed */
300 	if (mmapable) {
301 		BUG_ON(!PAGE_ALIGNED(size));
302 		align = SHMLBA;
303 		flags = VM_USERMAP;
304 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
305 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
306 				    numa_node);
307 		if (area != NULL)
308 			return area;
309 	}
310 
311 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
312 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
313 			flags, numa_node, __builtin_return_address(0));
314 }
315 
bpf_map_area_alloc(u64 size,int numa_node)316 void *bpf_map_area_alloc(u64 size, int numa_node)
317 {
318 	return __bpf_map_area_alloc(size, numa_node, false);
319 }
320 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)321 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
322 {
323 	return __bpf_map_area_alloc(size, numa_node, true);
324 }
325 
bpf_map_area_free(void * area)326 void bpf_map_area_free(void *area)
327 {
328 	kvfree(area);
329 }
330 
bpf_map_flags_retain_permanent(u32 flags)331 static u32 bpf_map_flags_retain_permanent(u32 flags)
332 {
333 	/* Some map creation flags are not tied to the map object but
334 	 * rather to the map fd instead, so they have no meaning upon
335 	 * map object inspection since multiple file descriptors with
336 	 * different (access) properties can exist here. Thus, given
337 	 * this has zero meaning for the map itself, lets clear these
338 	 * from here.
339 	 */
340 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
341 }
342 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)343 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
344 {
345 	map->map_type = attr->map_type;
346 	map->key_size = attr->key_size;
347 	map->value_size = attr->value_size;
348 	map->max_entries = attr->max_entries;
349 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
350 	map->numa_node = bpf_map_attr_numa_node(attr);
351 }
352 
bpf_map_alloc_id(struct bpf_map * map)353 static int bpf_map_alloc_id(struct bpf_map *map)
354 {
355 	int id;
356 
357 	idr_preload(GFP_KERNEL);
358 	spin_lock_bh(&map_idr_lock);
359 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
360 	if (id > 0)
361 		map->id = id;
362 	spin_unlock_bh(&map_idr_lock);
363 	idr_preload_end();
364 
365 	if (WARN_ON_ONCE(!id))
366 		return -ENOSPC;
367 
368 	return id > 0 ? 0 : id;
369 }
370 
bpf_map_free_id(struct bpf_map * map,bool do_idr_lock)371 void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
372 {
373 	unsigned long flags;
374 
375 	/* Offloaded maps are removed from the IDR store when their device
376 	 * disappears - even if someone holds an fd to them they are unusable,
377 	 * the memory is gone, all ops will fail; they are simply waiting for
378 	 * refcnt to drop to be freed.
379 	 */
380 	if (!map->id)
381 		return;
382 
383 	if (do_idr_lock)
384 		spin_lock_irqsave(&map_idr_lock, flags);
385 	else
386 		__acquire(&map_idr_lock);
387 
388 	idr_remove(&map_idr, map->id);
389 	map->id = 0;
390 
391 	if (do_idr_lock)
392 		spin_unlock_irqrestore(&map_idr_lock, flags);
393 	else
394 		__release(&map_idr_lock);
395 }
396 
397 #ifdef CONFIG_MEMCG_KMEM
bpf_map_save_memcg(struct bpf_map * map)398 static void bpf_map_save_memcg(struct bpf_map *map)
399 {
400 	map->memcg = get_mem_cgroup_from_mm(current->mm);
401 }
402 
bpf_map_release_memcg(struct bpf_map * map)403 static void bpf_map_release_memcg(struct bpf_map *map)
404 {
405 	mem_cgroup_put(map->memcg);
406 }
407 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)408 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
409 			   int node)
410 {
411 	struct mem_cgroup *old_memcg;
412 	void *ptr;
413 
414 	old_memcg = set_active_memcg(map->memcg);
415 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
416 	set_active_memcg(old_memcg);
417 
418 	return ptr;
419 }
420 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)421 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
422 {
423 	struct mem_cgroup *old_memcg;
424 	void *ptr;
425 
426 	old_memcg = set_active_memcg(map->memcg);
427 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
428 	set_active_memcg(old_memcg);
429 
430 	return ptr;
431 }
432 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)433 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
434 				    size_t align, gfp_t flags)
435 {
436 	struct mem_cgroup *old_memcg;
437 	void __percpu *ptr;
438 
439 	old_memcg = set_active_memcg(map->memcg);
440 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
441 	set_active_memcg(old_memcg);
442 
443 	return ptr;
444 }
445 
446 #else
bpf_map_save_memcg(struct bpf_map * map)447 static void bpf_map_save_memcg(struct bpf_map *map)
448 {
449 }
450 
bpf_map_release_memcg(struct bpf_map * map)451 static void bpf_map_release_memcg(struct bpf_map *map)
452 {
453 }
454 #endif
455 
456 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)457 static void bpf_map_free_deferred(struct work_struct *work)
458 {
459 	struct bpf_map *map = container_of(work, struct bpf_map, work);
460 
461 	security_bpf_map_free(map);
462 	bpf_map_release_memcg(map);
463 	/* implementation dependent freeing */
464 	map->ops->map_free(map);
465 }
466 
bpf_map_put_uref(struct bpf_map * map)467 static void bpf_map_put_uref(struct bpf_map *map)
468 {
469 	if (atomic64_dec_and_test(&map->usercnt)) {
470 		if (map->ops->map_release_uref)
471 			map->ops->map_release_uref(map);
472 	}
473 }
474 
475 /* decrement map refcnt and schedule it for freeing via workqueue
476  * (unrelying map implementation ops->map_free() might sleep)
477  */
__bpf_map_put(struct bpf_map * map,bool do_idr_lock)478 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
479 {
480 	if (atomic64_dec_and_test(&map->refcnt)) {
481 		/* bpf_map_free_id() must be called first */
482 		bpf_map_free_id(map, do_idr_lock);
483 		btf_put(map->btf);
484 		INIT_WORK(&map->work, bpf_map_free_deferred);
485 		schedule_work(&map->work);
486 	}
487 }
488 
bpf_map_put(struct bpf_map * map)489 void bpf_map_put(struct bpf_map *map)
490 {
491 	__bpf_map_put(map, true);
492 }
493 EXPORT_SYMBOL_GPL(bpf_map_put);
494 
bpf_map_put_with_uref(struct bpf_map * map)495 void bpf_map_put_with_uref(struct bpf_map *map)
496 {
497 	bpf_map_put_uref(map);
498 	bpf_map_put(map);
499 }
500 
bpf_map_release(struct inode * inode,struct file * filp)501 static int bpf_map_release(struct inode *inode, struct file *filp)
502 {
503 	struct bpf_map *map = filp->private_data;
504 
505 	if (map->ops->map_release)
506 		map->ops->map_release(map, filp);
507 
508 	bpf_map_put_with_uref(map);
509 	return 0;
510 }
511 
map_get_sys_perms(struct bpf_map * map,struct fd f)512 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
513 {
514 	fmode_t mode = f.file->f_mode;
515 
516 	/* Our file permissions may have been overridden by global
517 	 * map permissions facing syscall side.
518 	 */
519 	if (READ_ONCE(map->frozen))
520 		mode &= ~FMODE_CAN_WRITE;
521 	return mode;
522 }
523 
524 #ifdef CONFIG_PROC_FS
525 /* Provides an approximation of the map's memory footprint.
526  * Used only to provide a backward compatibility and display
527  * a reasonable "memlock" info.
528  */
bpf_map_memory_footprint(const struct bpf_map * map)529 static unsigned long bpf_map_memory_footprint(const struct bpf_map *map)
530 {
531 	unsigned long size;
532 
533 	size = round_up(map->key_size + bpf_map_value_size(map), 8);
534 
535 	return round_up(map->max_entries * size, PAGE_SIZE);
536 }
537 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)538 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
539 {
540 	const struct bpf_map *map = filp->private_data;
541 	const struct bpf_array *array;
542 	u32 type = 0, jited = 0;
543 
544 	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
545 		array = container_of(map, struct bpf_array, map);
546 		spin_lock(&array->aux->owner.lock);
547 		type  = array->aux->owner.type;
548 		jited = array->aux->owner.jited;
549 		spin_unlock(&array->aux->owner.lock);
550 	}
551 
552 	seq_printf(m,
553 		   "map_type:\t%u\n"
554 		   "key_size:\t%u\n"
555 		   "value_size:\t%u\n"
556 		   "max_entries:\t%u\n"
557 		   "map_flags:\t%#x\n"
558 		   "memlock:\t%lu\n"
559 		   "map_id:\t%u\n"
560 		   "frozen:\t%u\n",
561 		   map->map_type,
562 		   map->key_size,
563 		   map->value_size,
564 		   map->max_entries,
565 		   map->map_flags,
566 		   bpf_map_memory_footprint(map),
567 		   map->id,
568 		   READ_ONCE(map->frozen));
569 	if (type) {
570 		seq_printf(m, "owner_prog_type:\t%u\n", type);
571 		seq_printf(m, "owner_jited:\t%u\n", jited);
572 	}
573 }
574 #endif
575 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)576 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
577 			      loff_t *ppos)
578 {
579 	/* We need this handler such that alloc_file() enables
580 	 * f_mode with FMODE_CAN_READ.
581 	 */
582 	return -EINVAL;
583 }
584 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)585 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
586 			       size_t siz, loff_t *ppos)
587 {
588 	/* We need this handler such that alloc_file() enables
589 	 * f_mode with FMODE_CAN_WRITE.
590 	 */
591 	return -EINVAL;
592 }
593 
594 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)595 static void bpf_map_mmap_open(struct vm_area_struct *vma)
596 {
597 	struct bpf_map *map = vma->vm_file->private_data;
598 
599 	if (vma->vm_flags & VM_MAYWRITE) {
600 		mutex_lock(&map->freeze_mutex);
601 		map->writecnt++;
602 		mutex_unlock(&map->freeze_mutex);
603 	}
604 }
605 
606 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)607 static void bpf_map_mmap_close(struct vm_area_struct *vma)
608 {
609 	struct bpf_map *map = vma->vm_file->private_data;
610 
611 	if (vma->vm_flags & VM_MAYWRITE) {
612 		mutex_lock(&map->freeze_mutex);
613 		map->writecnt--;
614 		mutex_unlock(&map->freeze_mutex);
615 	}
616 }
617 
618 static const struct vm_operations_struct bpf_map_default_vmops = {
619 	.open		= bpf_map_mmap_open,
620 	.close		= bpf_map_mmap_close,
621 };
622 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)623 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
624 {
625 	struct bpf_map *map = filp->private_data;
626 	int err;
627 
628 	if (!map->ops->map_mmap || map_value_has_spin_lock(map) ||
629 	    map_value_has_timer(map))
630 		return -ENOTSUPP;
631 
632 	if (!(vma->vm_flags & VM_SHARED))
633 		return -EINVAL;
634 
635 	mutex_lock(&map->freeze_mutex);
636 
637 	if (vma->vm_flags & VM_WRITE) {
638 		if (map->frozen) {
639 			err = -EPERM;
640 			goto out;
641 		}
642 		/* map is meant to be read-only, so do not allow mapping as
643 		 * writable, because it's possible to leak a writable page
644 		 * reference and allows user-space to still modify it after
645 		 * freezing, while verifier will assume contents do not change
646 		 */
647 		if (map->map_flags & BPF_F_RDONLY_PROG) {
648 			err = -EACCES;
649 			goto out;
650 		}
651 	}
652 
653 	/* set default open/close callbacks */
654 	vma->vm_ops = &bpf_map_default_vmops;
655 	vma->vm_private_data = map;
656 	vma->vm_flags &= ~VM_MAYEXEC;
657 	if (!(vma->vm_flags & VM_WRITE))
658 		/* disallow re-mapping with PROT_WRITE */
659 		vma->vm_flags &= ~VM_MAYWRITE;
660 
661 	err = map->ops->map_mmap(map, vma);
662 	if (err)
663 		goto out;
664 
665 	if (vma->vm_flags & VM_MAYWRITE)
666 		map->writecnt++;
667 out:
668 	mutex_unlock(&map->freeze_mutex);
669 	return err;
670 }
671 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)672 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
673 {
674 	struct bpf_map *map = filp->private_data;
675 
676 	if (map->ops->map_poll)
677 		return map->ops->map_poll(map, filp, pts);
678 
679 	return EPOLLERR;
680 }
681 
682 const struct file_operations bpf_map_fops = {
683 #ifdef CONFIG_PROC_FS
684 	.show_fdinfo	= bpf_map_show_fdinfo,
685 #endif
686 	.release	= bpf_map_release,
687 	.read		= bpf_dummy_read,
688 	.write		= bpf_dummy_write,
689 	.mmap		= bpf_map_mmap,
690 	.poll		= bpf_map_poll,
691 };
692 
bpf_map_new_fd(struct bpf_map * map,int flags)693 int bpf_map_new_fd(struct bpf_map *map, int flags)
694 {
695 	int ret;
696 
697 	ret = security_bpf_map(map, OPEN_FMODE(flags));
698 	if (ret < 0)
699 		return ret;
700 
701 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
702 				flags | O_CLOEXEC);
703 }
704 
bpf_get_file_flag(int flags)705 int bpf_get_file_flag(int flags)
706 {
707 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
708 		return -EINVAL;
709 	if (flags & BPF_F_RDONLY)
710 		return O_RDONLY;
711 	if (flags & BPF_F_WRONLY)
712 		return O_WRONLY;
713 	return O_RDWR;
714 }
715 
716 /* helper macro to check that unused fields 'union bpf_attr' are zero */
717 #define CHECK_ATTR(CMD) \
718 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
719 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
720 		   sizeof(*attr) - \
721 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
722 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
723 
724 /* dst and src must have at least "size" number of bytes.
725  * Return strlen on success and < 0 on error.
726  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)727 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
728 {
729 	const char *end = src + size;
730 	const char *orig_src = src;
731 
732 	memset(dst, 0, size);
733 	/* Copy all isalnum(), '_' and '.' chars. */
734 	while (src < end && *src) {
735 		if (!isalnum(*src) &&
736 		    *src != '_' && *src != '.')
737 			return -EINVAL;
738 		*dst++ = *src++;
739 	}
740 
741 	/* No '\0' found in "size" number of bytes */
742 	if (src == end)
743 		return -EINVAL;
744 
745 	return src - orig_src;
746 }
747 
map_check_no_btf(const struct bpf_map * map,const struct btf * btf,const struct btf_type * key_type,const struct btf_type * value_type)748 int map_check_no_btf(const struct bpf_map *map,
749 		     const struct btf *btf,
750 		     const struct btf_type *key_type,
751 		     const struct btf_type *value_type)
752 {
753 	return -ENOTSUPP;
754 }
755 
map_check_btf(struct bpf_map * map,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)756 static int map_check_btf(struct bpf_map *map, const struct btf *btf,
757 			 u32 btf_key_id, u32 btf_value_id)
758 {
759 	const struct btf_type *key_type, *value_type;
760 	u32 key_size, value_size;
761 	int ret = 0;
762 
763 	/* Some maps allow key to be unspecified. */
764 	if (btf_key_id) {
765 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
766 		if (!key_type || key_size != map->key_size)
767 			return -EINVAL;
768 	} else {
769 		key_type = btf_type_by_id(btf, 0);
770 		if (!map->ops->map_check_btf)
771 			return -EINVAL;
772 	}
773 
774 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
775 	if (!value_type || value_size != map->value_size)
776 		return -EINVAL;
777 
778 	map->spin_lock_off = btf_find_spin_lock(btf, value_type);
779 
780 	if (map_value_has_spin_lock(map)) {
781 		if (map->map_flags & BPF_F_RDONLY_PROG)
782 			return -EACCES;
783 		if (map->map_type != BPF_MAP_TYPE_HASH &&
784 		    map->map_type != BPF_MAP_TYPE_ARRAY &&
785 		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
786 		    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
787 		    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
788 		    map->map_type != BPF_MAP_TYPE_TASK_STORAGE)
789 			return -ENOTSUPP;
790 		if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
791 		    map->value_size) {
792 			WARN_ONCE(1,
793 				  "verifier bug spin_lock_off %d value_size %d\n",
794 				  map->spin_lock_off, map->value_size);
795 			return -EFAULT;
796 		}
797 	}
798 
799 	map->timer_off = btf_find_timer(btf, value_type);
800 	if (map_value_has_timer(map)) {
801 		if (map->map_flags & BPF_F_RDONLY_PROG)
802 			return -EACCES;
803 		if (map->map_type != BPF_MAP_TYPE_HASH &&
804 		    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
805 		    map->map_type != BPF_MAP_TYPE_ARRAY)
806 			return -EOPNOTSUPP;
807 	}
808 
809 	if (map->ops->map_check_btf)
810 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
811 
812 	return ret;
813 }
814 
815 #define BPF_MAP_CREATE_LAST_FIELD btf_vmlinux_value_type_id
816 /* called via syscall */
map_create(union bpf_attr * attr)817 static int map_create(union bpf_attr *attr)
818 {
819 	int numa_node = bpf_map_attr_numa_node(attr);
820 	struct bpf_map *map;
821 	int f_flags;
822 	int err;
823 
824 	err = CHECK_ATTR(BPF_MAP_CREATE);
825 	if (err)
826 		return -EINVAL;
827 
828 	if (attr->btf_vmlinux_value_type_id) {
829 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
830 		    attr->btf_key_type_id || attr->btf_value_type_id)
831 			return -EINVAL;
832 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
833 		return -EINVAL;
834 	}
835 
836 	f_flags = bpf_get_file_flag(attr->map_flags);
837 	if (f_flags < 0)
838 		return f_flags;
839 
840 	if (numa_node != NUMA_NO_NODE &&
841 	    ((unsigned int)numa_node >= nr_node_ids ||
842 	     !node_online(numa_node)))
843 		return -EINVAL;
844 
845 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
846 	map = find_and_alloc_map(attr);
847 	if (IS_ERR(map))
848 		return PTR_ERR(map);
849 
850 	err = bpf_obj_name_cpy(map->name, attr->map_name,
851 			       sizeof(attr->map_name));
852 	if (err < 0)
853 		goto free_map;
854 
855 	atomic64_set(&map->refcnt, 1);
856 	atomic64_set(&map->usercnt, 1);
857 	mutex_init(&map->freeze_mutex);
858 
859 	map->spin_lock_off = -EINVAL;
860 	map->timer_off = -EINVAL;
861 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
862 	    /* Even the map's value is a kernel's struct,
863 	     * the bpf_prog.o must have BTF to begin with
864 	     * to figure out the corresponding kernel's
865 	     * counter part.  Thus, attr->btf_fd has
866 	     * to be valid also.
867 	     */
868 	    attr->btf_vmlinux_value_type_id) {
869 		struct btf *btf;
870 
871 		btf = btf_get_by_fd(attr->btf_fd);
872 		if (IS_ERR(btf)) {
873 			err = PTR_ERR(btf);
874 			goto free_map;
875 		}
876 		if (btf_is_kernel(btf)) {
877 			btf_put(btf);
878 			err = -EACCES;
879 			goto free_map;
880 		}
881 		map->btf = btf;
882 
883 		if (attr->btf_value_type_id) {
884 			err = map_check_btf(map, btf, attr->btf_key_type_id,
885 					    attr->btf_value_type_id);
886 			if (err)
887 				goto free_map;
888 		}
889 
890 		map->btf_key_type_id = attr->btf_key_type_id;
891 		map->btf_value_type_id = attr->btf_value_type_id;
892 		map->btf_vmlinux_value_type_id =
893 			attr->btf_vmlinux_value_type_id;
894 	}
895 
896 	err = security_bpf_map_alloc(map);
897 	if (err)
898 		goto free_map;
899 
900 	err = bpf_map_alloc_id(map);
901 	if (err)
902 		goto free_map_sec;
903 
904 	bpf_map_save_memcg(map);
905 
906 	err = bpf_map_new_fd(map, f_flags);
907 	if (err < 0) {
908 		/* failed to allocate fd.
909 		 * bpf_map_put_with_uref() is needed because the above
910 		 * bpf_map_alloc_id() has published the map
911 		 * to the userspace and the userspace may
912 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
913 		 */
914 		bpf_map_put_with_uref(map);
915 		return err;
916 	}
917 
918 	return err;
919 
920 free_map_sec:
921 	security_bpf_map_free(map);
922 free_map:
923 	btf_put(map->btf);
924 	map->ops->map_free(map);
925 	return err;
926 }
927 
928 /* if error is returned, fd is released.
929  * On success caller should complete fd access with matching fdput()
930  */
__bpf_map_get(struct fd f)931 struct bpf_map *__bpf_map_get(struct fd f)
932 {
933 	if (!f.file)
934 		return ERR_PTR(-EBADF);
935 	if (f.file->f_op != &bpf_map_fops) {
936 		fdput(f);
937 		return ERR_PTR(-EINVAL);
938 	}
939 
940 	return f.file->private_data;
941 }
942 
bpf_map_inc(struct bpf_map * map)943 void bpf_map_inc(struct bpf_map *map)
944 {
945 	atomic64_inc(&map->refcnt);
946 }
947 EXPORT_SYMBOL_GPL(bpf_map_inc);
948 
bpf_map_inc_with_uref(struct bpf_map * map)949 void bpf_map_inc_with_uref(struct bpf_map *map)
950 {
951 	atomic64_inc(&map->refcnt);
952 	atomic64_inc(&map->usercnt);
953 }
954 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
955 
bpf_map_get(u32 ufd)956 struct bpf_map *bpf_map_get(u32 ufd)
957 {
958 	struct fd f = fdget(ufd);
959 	struct bpf_map *map;
960 
961 	map = __bpf_map_get(f);
962 	if (IS_ERR(map))
963 		return map;
964 
965 	bpf_map_inc(map);
966 	fdput(f);
967 
968 	return map;
969 }
970 
bpf_map_get_with_uref(u32 ufd)971 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
972 {
973 	struct fd f = fdget(ufd);
974 	struct bpf_map *map;
975 
976 	map = __bpf_map_get(f);
977 	if (IS_ERR(map))
978 		return map;
979 
980 	bpf_map_inc_with_uref(map);
981 	fdput(f);
982 
983 	return map;
984 }
985 
986 /* map_idr_lock should have been held */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)987 static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
988 {
989 	int refold;
990 
991 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
992 	if (!refold)
993 		return ERR_PTR(-ENOENT);
994 	if (uref)
995 		atomic64_inc(&map->usercnt);
996 
997 	return map;
998 }
999 
bpf_map_inc_not_zero(struct bpf_map * map)1000 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1001 {
1002 	spin_lock_bh(&map_idr_lock);
1003 	map = __bpf_map_inc_not_zero(map, false);
1004 	spin_unlock_bh(&map_idr_lock);
1005 
1006 	return map;
1007 }
1008 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1009 
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1010 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1011 {
1012 	return -ENOTSUPP;
1013 }
1014 
__bpf_copy_key(void __user * ukey,u64 key_size)1015 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1016 {
1017 	if (key_size)
1018 		return vmemdup_user(ukey, key_size);
1019 
1020 	if (ukey)
1021 		return ERR_PTR(-EINVAL);
1022 
1023 	return NULL;
1024 }
1025 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1026 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1027 {
1028 	if (key_size)
1029 		return kvmemdup_bpfptr(ukey, key_size);
1030 
1031 	if (!bpfptr_is_null(ukey))
1032 		return ERR_PTR(-EINVAL);
1033 
1034 	return NULL;
1035 }
1036 
1037 /* last field in 'union bpf_attr' used by this command */
1038 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1039 
map_lookup_elem(union bpf_attr * attr)1040 static int map_lookup_elem(union bpf_attr *attr)
1041 {
1042 	void __user *ukey = u64_to_user_ptr(attr->key);
1043 	void __user *uvalue = u64_to_user_ptr(attr->value);
1044 	int ufd = attr->map_fd;
1045 	struct bpf_map *map;
1046 	void *key, *value;
1047 	u32 value_size;
1048 	struct fd f;
1049 	int err;
1050 
1051 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1052 		return -EINVAL;
1053 
1054 	if (attr->flags & ~BPF_F_LOCK)
1055 		return -EINVAL;
1056 
1057 	f = fdget(ufd);
1058 	map = __bpf_map_get(f);
1059 	if (IS_ERR(map))
1060 		return PTR_ERR(map);
1061 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1062 		err = -EPERM;
1063 		goto err_put;
1064 	}
1065 
1066 	if ((attr->flags & BPF_F_LOCK) &&
1067 	    !map_value_has_spin_lock(map)) {
1068 		err = -EINVAL;
1069 		goto err_put;
1070 	}
1071 
1072 	key = __bpf_copy_key(ukey, map->key_size);
1073 	if (IS_ERR(key)) {
1074 		err = PTR_ERR(key);
1075 		goto err_put;
1076 	}
1077 
1078 	value_size = bpf_map_value_size(map);
1079 
1080 	err = -ENOMEM;
1081 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1082 	if (!value)
1083 		goto free_key;
1084 
1085 	err = bpf_map_copy_value(map, key, value, attr->flags);
1086 	if (err)
1087 		goto free_value;
1088 
1089 	err = -EFAULT;
1090 	if (copy_to_user(uvalue, value, value_size) != 0)
1091 		goto free_value;
1092 
1093 	err = 0;
1094 
1095 free_value:
1096 	kvfree(value);
1097 free_key:
1098 	kvfree(key);
1099 err_put:
1100 	fdput(f);
1101 	return err;
1102 }
1103 
1104 
1105 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1106 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1107 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1108 {
1109 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1110 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1111 	int ufd = attr->map_fd;
1112 	struct bpf_map *map;
1113 	void *key, *value;
1114 	u32 value_size;
1115 	struct fd f;
1116 	int err;
1117 
1118 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1119 		return -EINVAL;
1120 
1121 	f = fdget(ufd);
1122 	map = __bpf_map_get(f);
1123 	if (IS_ERR(map))
1124 		return PTR_ERR(map);
1125 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1126 		err = -EPERM;
1127 		goto err_put;
1128 	}
1129 
1130 	if ((attr->flags & BPF_F_LOCK) &&
1131 	    !map_value_has_spin_lock(map)) {
1132 		err = -EINVAL;
1133 		goto err_put;
1134 	}
1135 
1136 	key = ___bpf_copy_key(ukey, map->key_size);
1137 	if (IS_ERR(key)) {
1138 		err = PTR_ERR(key);
1139 		goto err_put;
1140 	}
1141 
1142 	value_size = bpf_map_value_size(map);
1143 
1144 	err = -ENOMEM;
1145 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1146 	if (!value)
1147 		goto free_key;
1148 
1149 	err = -EFAULT;
1150 	if (copy_from_bpfptr(value, uvalue, value_size) != 0)
1151 		goto free_value;
1152 
1153 	err = bpf_map_update_value(map, f, key, value, attr->flags);
1154 
1155 free_value:
1156 	kvfree(value);
1157 free_key:
1158 	kvfree(key);
1159 err_put:
1160 	fdput(f);
1161 	return err;
1162 }
1163 
1164 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1165 
map_delete_elem(union bpf_attr * attr)1166 static int map_delete_elem(union bpf_attr *attr)
1167 {
1168 	void __user *ukey = u64_to_user_ptr(attr->key);
1169 	int ufd = attr->map_fd;
1170 	struct bpf_map *map;
1171 	struct fd f;
1172 	void *key;
1173 	int err;
1174 
1175 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1176 		return -EINVAL;
1177 
1178 	f = fdget(ufd);
1179 	map = __bpf_map_get(f);
1180 	if (IS_ERR(map))
1181 		return PTR_ERR(map);
1182 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1183 		err = -EPERM;
1184 		goto err_put;
1185 	}
1186 
1187 	key = __bpf_copy_key(ukey, map->key_size);
1188 	if (IS_ERR(key)) {
1189 		err = PTR_ERR(key);
1190 		goto err_put;
1191 	}
1192 
1193 	if (bpf_map_is_dev_bound(map)) {
1194 		err = bpf_map_offload_delete_elem(map, key);
1195 		goto out;
1196 	} else if (IS_FD_PROG_ARRAY(map) ||
1197 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1198 		/* These maps require sleepable context */
1199 		err = map->ops->map_delete_elem(map, key);
1200 		goto out;
1201 	}
1202 
1203 	bpf_disable_instrumentation();
1204 	rcu_read_lock();
1205 	err = map->ops->map_delete_elem(map, key);
1206 	rcu_read_unlock();
1207 	bpf_enable_instrumentation();
1208 	maybe_wait_bpf_programs(map);
1209 out:
1210 	kvfree(key);
1211 err_put:
1212 	fdput(f);
1213 	return err;
1214 }
1215 
1216 /* last field in 'union bpf_attr' used by this command */
1217 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1218 
map_get_next_key(union bpf_attr * attr)1219 static int map_get_next_key(union bpf_attr *attr)
1220 {
1221 	void __user *ukey = u64_to_user_ptr(attr->key);
1222 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1223 	int ufd = attr->map_fd;
1224 	struct bpf_map *map;
1225 	void *key, *next_key;
1226 	struct fd f;
1227 	int err;
1228 
1229 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1230 		return -EINVAL;
1231 
1232 	f = fdget(ufd);
1233 	map = __bpf_map_get(f);
1234 	if (IS_ERR(map))
1235 		return PTR_ERR(map);
1236 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1237 		err = -EPERM;
1238 		goto err_put;
1239 	}
1240 
1241 	if (ukey) {
1242 		key = __bpf_copy_key(ukey, map->key_size);
1243 		if (IS_ERR(key)) {
1244 			err = PTR_ERR(key);
1245 			goto err_put;
1246 		}
1247 	} else {
1248 		key = NULL;
1249 	}
1250 
1251 	err = -ENOMEM;
1252 	next_key = kvmalloc(map->key_size, GFP_USER);
1253 	if (!next_key)
1254 		goto free_key;
1255 
1256 	if (bpf_map_is_dev_bound(map)) {
1257 		err = bpf_map_offload_get_next_key(map, key, next_key);
1258 		goto out;
1259 	}
1260 
1261 	rcu_read_lock();
1262 	err = map->ops->map_get_next_key(map, key, next_key);
1263 	rcu_read_unlock();
1264 out:
1265 	if (err)
1266 		goto free_next_key;
1267 
1268 	err = -EFAULT;
1269 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1270 		goto free_next_key;
1271 
1272 	err = 0;
1273 
1274 free_next_key:
1275 	kvfree(next_key);
1276 free_key:
1277 	kvfree(key);
1278 err_put:
1279 	fdput(f);
1280 	return err;
1281 }
1282 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1283 int generic_map_delete_batch(struct bpf_map *map,
1284 			     const union bpf_attr *attr,
1285 			     union bpf_attr __user *uattr)
1286 {
1287 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1288 	u32 cp, max_count;
1289 	int err = 0;
1290 	void *key;
1291 
1292 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1293 		return -EINVAL;
1294 
1295 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1296 	    !map_value_has_spin_lock(map)) {
1297 		return -EINVAL;
1298 	}
1299 
1300 	max_count = attr->batch.count;
1301 	if (!max_count)
1302 		return 0;
1303 
1304 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1305 	if (!key)
1306 		return -ENOMEM;
1307 
1308 	for (cp = 0; cp < max_count; cp++) {
1309 		err = -EFAULT;
1310 		if (copy_from_user(key, keys + cp * map->key_size,
1311 				   map->key_size))
1312 			break;
1313 
1314 		if (bpf_map_is_dev_bound(map)) {
1315 			err = bpf_map_offload_delete_elem(map, key);
1316 			break;
1317 		}
1318 
1319 		bpf_disable_instrumentation();
1320 		rcu_read_lock();
1321 		err = map->ops->map_delete_elem(map, key);
1322 		rcu_read_unlock();
1323 		bpf_enable_instrumentation();
1324 		maybe_wait_bpf_programs(map);
1325 		if (err)
1326 			break;
1327 	}
1328 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1329 		err = -EFAULT;
1330 
1331 	kvfree(key);
1332 	return err;
1333 }
1334 
generic_map_update_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1335 int generic_map_update_batch(struct bpf_map *map,
1336 			     const union bpf_attr *attr,
1337 			     union bpf_attr __user *uattr)
1338 {
1339 	void __user *values = u64_to_user_ptr(attr->batch.values);
1340 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1341 	u32 value_size, cp, max_count;
1342 	int ufd = attr->batch.map_fd;
1343 	void *key, *value;
1344 	struct fd f;
1345 	int err = 0;
1346 
1347 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1348 		return -EINVAL;
1349 
1350 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1351 	    !map_value_has_spin_lock(map)) {
1352 		return -EINVAL;
1353 	}
1354 
1355 	value_size = bpf_map_value_size(map);
1356 
1357 	max_count = attr->batch.count;
1358 	if (!max_count)
1359 		return 0;
1360 
1361 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1362 	if (!key)
1363 		return -ENOMEM;
1364 
1365 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1366 	if (!value) {
1367 		kvfree(key);
1368 		return -ENOMEM;
1369 	}
1370 
1371 	f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */
1372 	for (cp = 0; cp < max_count; cp++) {
1373 		err = -EFAULT;
1374 		if (copy_from_user(key, keys + cp * map->key_size,
1375 		    map->key_size) ||
1376 		    copy_from_user(value, values + cp * value_size, value_size))
1377 			break;
1378 
1379 		err = bpf_map_update_value(map, f, key, value,
1380 					   attr->batch.elem_flags);
1381 
1382 		if (err)
1383 			break;
1384 	}
1385 
1386 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1387 		err = -EFAULT;
1388 
1389 	kvfree(value);
1390 	kvfree(key);
1391 	fdput(f);
1392 	return err;
1393 }
1394 
1395 #define MAP_LOOKUP_RETRIES 3
1396 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1397 int generic_map_lookup_batch(struct bpf_map *map,
1398 				    const union bpf_attr *attr,
1399 				    union bpf_attr __user *uattr)
1400 {
1401 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
1402 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1403 	void __user *values = u64_to_user_ptr(attr->batch.values);
1404 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1405 	void *buf, *buf_prevkey, *prev_key, *key, *value;
1406 	int err, retry = MAP_LOOKUP_RETRIES;
1407 	u32 value_size, cp, max_count;
1408 
1409 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1410 		return -EINVAL;
1411 
1412 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1413 	    !map_value_has_spin_lock(map))
1414 		return -EINVAL;
1415 
1416 	value_size = bpf_map_value_size(map);
1417 
1418 	max_count = attr->batch.count;
1419 	if (!max_count)
1420 		return 0;
1421 
1422 	if (put_user(0, &uattr->batch.count))
1423 		return -EFAULT;
1424 
1425 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1426 	if (!buf_prevkey)
1427 		return -ENOMEM;
1428 
1429 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
1430 	if (!buf) {
1431 		kvfree(buf_prevkey);
1432 		return -ENOMEM;
1433 	}
1434 
1435 	err = -EFAULT;
1436 	prev_key = NULL;
1437 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
1438 		goto free_buf;
1439 	key = buf;
1440 	value = key + map->key_size;
1441 	if (ubatch)
1442 		prev_key = buf_prevkey;
1443 
1444 	for (cp = 0; cp < max_count;) {
1445 		rcu_read_lock();
1446 		err = map->ops->map_get_next_key(map, prev_key, key);
1447 		rcu_read_unlock();
1448 		if (err)
1449 			break;
1450 		err = bpf_map_copy_value(map, key, value,
1451 					 attr->batch.elem_flags);
1452 
1453 		if (err == -ENOENT) {
1454 			if (retry) {
1455 				retry--;
1456 				continue;
1457 			}
1458 			err = -EINTR;
1459 			break;
1460 		}
1461 
1462 		if (err)
1463 			goto free_buf;
1464 
1465 		if (copy_to_user(keys + cp * map->key_size, key,
1466 				 map->key_size)) {
1467 			err = -EFAULT;
1468 			goto free_buf;
1469 		}
1470 		if (copy_to_user(values + cp * value_size, value, value_size)) {
1471 			err = -EFAULT;
1472 			goto free_buf;
1473 		}
1474 
1475 		if (!prev_key)
1476 			prev_key = buf_prevkey;
1477 
1478 		swap(prev_key, key);
1479 		retry = MAP_LOOKUP_RETRIES;
1480 		cp++;
1481 	}
1482 
1483 	if (err == -EFAULT)
1484 		goto free_buf;
1485 
1486 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
1487 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
1488 		err = -EFAULT;
1489 
1490 free_buf:
1491 	kvfree(buf_prevkey);
1492 	kvfree(buf);
1493 	return err;
1494 }
1495 
1496 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
1497 
map_lookup_and_delete_elem(union bpf_attr * attr)1498 static int map_lookup_and_delete_elem(union bpf_attr *attr)
1499 {
1500 	void __user *ukey = u64_to_user_ptr(attr->key);
1501 	void __user *uvalue = u64_to_user_ptr(attr->value);
1502 	int ufd = attr->map_fd;
1503 	struct bpf_map *map;
1504 	void *key, *value;
1505 	u32 value_size;
1506 	struct fd f;
1507 	int err;
1508 
1509 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
1510 		return -EINVAL;
1511 
1512 	if (attr->flags & ~BPF_F_LOCK)
1513 		return -EINVAL;
1514 
1515 	f = fdget(ufd);
1516 	map = __bpf_map_get(f);
1517 	if (IS_ERR(map))
1518 		return PTR_ERR(map);
1519 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
1520 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1521 		err = -EPERM;
1522 		goto err_put;
1523 	}
1524 
1525 	if (attr->flags &&
1526 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
1527 	     map->map_type == BPF_MAP_TYPE_STACK)) {
1528 		err = -EINVAL;
1529 		goto err_put;
1530 	}
1531 
1532 	if ((attr->flags & BPF_F_LOCK) &&
1533 	    !map_value_has_spin_lock(map)) {
1534 		err = -EINVAL;
1535 		goto err_put;
1536 	}
1537 
1538 	key = __bpf_copy_key(ukey, map->key_size);
1539 	if (IS_ERR(key)) {
1540 		err = PTR_ERR(key);
1541 		goto err_put;
1542 	}
1543 
1544 	value_size = bpf_map_value_size(map);
1545 
1546 	err = -ENOMEM;
1547 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1548 	if (!value)
1549 		goto free_key;
1550 
1551 	err = -ENOTSUPP;
1552 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
1553 	    map->map_type == BPF_MAP_TYPE_STACK) {
1554 		err = map->ops->map_pop_elem(map, value);
1555 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
1556 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
1557 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
1558 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
1559 		if (!bpf_map_is_dev_bound(map)) {
1560 			bpf_disable_instrumentation();
1561 			rcu_read_lock();
1562 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
1563 			rcu_read_unlock();
1564 			bpf_enable_instrumentation();
1565 		}
1566 	}
1567 
1568 	if (err)
1569 		goto free_value;
1570 
1571 	if (copy_to_user(uvalue, value, value_size) != 0) {
1572 		err = -EFAULT;
1573 		goto free_value;
1574 	}
1575 
1576 	err = 0;
1577 
1578 free_value:
1579 	kvfree(value);
1580 free_key:
1581 	kvfree(key);
1582 err_put:
1583 	fdput(f);
1584 	return err;
1585 }
1586 
1587 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
1588 
map_freeze(const union bpf_attr * attr)1589 static int map_freeze(const union bpf_attr *attr)
1590 {
1591 	int err = 0, ufd = attr->map_fd;
1592 	struct bpf_map *map;
1593 	struct fd f;
1594 
1595 	if (CHECK_ATTR(BPF_MAP_FREEZE))
1596 		return -EINVAL;
1597 
1598 	f = fdget(ufd);
1599 	map = __bpf_map_get(f);
1600 	if (IS_ERR(map))
1601 		return PTR_ERR(map);
1602 
1603 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS ||
1604 	    map_value_has_timer(map)) {
1605 		fdput(f);
1606 		return -ENOTSUPP;
1607 	}
1608 
1609 	mutex_lock(&map->freeze_mutex);
1610 
1611 	if (map->writecnt) {
1612 		err = -EBUSY;
1613 		goto err_put;
1614 	}
1615 	if (READ_ONCE(map->frozen)) {
1616 		err = -EBUSY;
1617 		goto err_put;
1618 	}
1619 	if (!bpf_capable()) {
1620 		err = -EPERM;
1621 		goto err_put;
1622 	}
1623 
1624 	WRITE_ONCE(map->frozen, true);
1625 err_put:
1626 	mutex_unlock(&map->freeze_mutex);
1627 	fdput(f);
1628 	return err;
1629 }
1630 
1631 static const struct bpf_prog_ops * const bpf_prog_types[] = {
1632 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
1633 	[_id] = & _name ## _prog_ops,
1634 #define BPF_MAP_TYPE(_id, _ops)
1635 #define BPF_LINK_TYPE(_id, _name)
1636 #include <linux/bpf_types.h>
1637 #undef BPF_PROG_TYPE
1638 #undef BPF_MAP_TYPE
1639 #undef BPF_LINK_TYPE
1640 };
1641 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)1642 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
1643 {
1644 	const struct bpf_prog_ops *ops;
1645 
1646 	if (type >= ARRAY_SIZE(bpf_prog_types))
1647 		return -EINVAL;
1648 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
1649 	ops = bpf_prog_types[type];
1650 	if (!ops)
1651 		return -EINVAL;
1652 
1653 	if (!bpf_prog_is_dev_bound(prog->aux))
1654 		prog->aux->ops = ops;
1655 	else
1656 		prog->aux->ops = &bpf_offload_prog_ops;
1657 	prog->type = type;
1658 	return 0;
1659 }
1660 
1661 enum bpf_audit {
1662 	BPF_AUDIT_LOAD,
1663 	BPF_AUDIT_UNLOAD,
1664 	BPF_AUDIT_MAX,
1665 };
1666 
1667 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
1668 	[BPF_AUDIT_LOAD]   = "LOAD",
1669 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
1670 };
1671 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)1672 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
1673 {
1674 	struct audit_context *ctx = NULL;
1675 	struct audit_buffer *ab;
1676 
1677 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
1678 		return;
1679 	if (audit_enabled == AUDIT_OFF)
1680 		return;
1681 	if (op == BPF_AUDIT_LOAD)
1682 		ctx = audit_context();
1683 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
1684 	if (unlikely(!ab))
1685 		return;
1686 	audit_log_format(ab, "prog-id=%u op=%s",
1687 			 prog->aux->id, bpf_audit_str[op]);
1688 	audit_log_end(ab);
1689 }
1690 
bpf_prog_alloc_id(struct bpf_prog * prog)1691 static int bpf_prog_alloc_id(struct bpf_prog *prog)
1692 {
1693 	int id;
1694 
1695 	idr_preload(GFP_KERNEL);
1696 	spin_lock_bh(&prog_idr_lock);
1697 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
1698 	if (id > 0)
1699 		prog->aux->id = id;
1700 	spin_unlock_bh(&prog_idr_lock);
1701 	idr_preload_end();
1702 
1703 	/* id is in [1, INT_MAX) */
1704 	if (WARN_ON_ONCE(!id))
1705 		return -ENOSPC;
1706 
1707 	return id > 0 ? 0 : id;
1708 }
1709 
bpf_prog_free_id(struct bpf_prog * prog,bool do_idr_lock)1710 void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
1711 {
1712 	unsigned long flags;
1713 
1714 	/* cBPF to eBPF migrations are currently not in the idr store.
1715 	 * Offloaded programs are removed from the store when their device
1716 	 * disappears - even if someone grabs an fd to them they are unusable,
1717 	 * simply waiting for refcnt to drop to be freed.
1718 	 */
1719 	if (!prog->aux->id)
1720 		return;
1721 
1722 	if (do_idr_lock)
1723 		spin_lock_irqsave(&prog_idr_lock, flags);
1724 	else
1725 		__acquire(&prog_idr_lock);
1726 
1727 	idr_remove(&prog_idr, prog->aux->id);
1728 	prog->aux->id = 0;
1729 
1730 	if (do_idr_lock)
1731 		spin_unlock_irqrestore(&prog_idr_lock, flags);
1732 	else
1733 		__release(&prog_idr_lock);
1734 }
1735 
__bpf_prog_put_rcu(struct rcu_head * rcu)1736 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
1737 {
1738 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
1739 
1740 	kvfree(aux->func_info);
1741 	kfree(aux->func_info_aux);
1742 	free_uid(aux->user);
1743 	security_bpf_prog_free(aux);
1744 	bpf_prog_free(aux->prog);
1745 }
1746 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)1747 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
1748 {
1749 	bpf_prog_kallsyms_del_all(prog);
1750 	btf_put(prog->aux->btf);
1751 	kvfree(prog->aux->jited_linfo);
1752 	kvfree(prog->aux->linfo);
1753 	kfree(prog->aux->kfunc_tab);
1754 	if (prog->aux->attach_btf)
1755 		btf_put(prog->aux->attach_btf);
1756 
1757 	if (deferred) {
1758 		if (prog->aux->sleepable)
1759 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
1760 		else
1761 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
1762 	} else {
1763 		__bpf_prog_put_rcu(&prog->aux->rcu);
1764 	}
1765 }
1766 
bpf_prog_put_deferred(struct work_struct * work)1767 static void bpf_prog_put_deferred(struct work_struct *work)
1768 {
1769 	struct bpf_prog_aux *aux;
1770 	struct bpf_prog *prog;
1771 
1772 	aux = container_of(work, struct bpf_prog_aux, work);
1773 	prog = aux->prog;
1774 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
1775 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
1776 	__bpf_prog_put_noref(prog, true);
1777 }
1778 
__bpf_prog_put(struct bpf_prog * prog,bool do_idr_lock)1779 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
1780 {
1781 	struct bpf_prog_aux *aux = prog->aux;
1782 
1783 	if (atomic64_dec_and_test(&aux->refcnt)) {
1784 		/* bpf_prog_free_id() must be called first */
1785 		bpf_prog_free_id(prog, do_idr_lock);
1786 
1787 		if (in_irq() || irqs_disabled()) {
1788 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
1789 			schedule_work(&aux->work);
1790 		} else {
1791 			bpf_prog_put_deferred(&aux->work);
1792 		}
1793 	}
1794 }
1795 
bpf_prog_put(struct bpf_prog * prog)1796 void bpf_prog_put(struct bpf_prog *prog)
1797 {
1798 	__bpf_prog_put(prog, true);
1799 }
1800 EXPORT_SYMBOL_GPL(bpf_prog_put);
1801 
bpf_prog_release(struct inode * inode,struct file * filp)1802 static int bpf_prog_release(struct inode *inode, struct file *filp)
1803 {
1804 	struct bpf_prog *prog = filp->private_data;
1805 
1806 	bpf_prog_put(prog);
1807 	return 0;
1808 }
1809 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_stats * stats)1810 static void bpf_prog_get_stats(const struct bpf_prog *prog,
1811 			       struct bpf_prog_stats *stats)
1812 {
1813 	u64 nsecs = 0, cnt = 0, misses = 0;
1814 	int cpu;
1815 
1816 	for_each_possible_cpu(cpu) {
1817 		const struct bpf_prog_stats *st;
1818 		unsigned int start;
1819 		u64 tnsecs, tcnt, tmisses;
1820 
1821 		st = per_cpu_ptr(prog->stats, cpu);
1822 		do {
1823 			start = u64_stats_fetch_begin_irq(&st->syncp);
1824 			tnsecs = st->nsecs;
1825 			tcnt = st->cnt;
1826 			tmisses = st->misses;
1827 		} while (u64_stats_fetch_retry_irq(&st->syncp, start));
1828 		nsecs += tnsecs;
1829 		cnt += tcnt;
1830 		misses += tmisses;
1831 	}
1832 	stats->nsecs = nsecs;
1833 	stats->cnt = cnt;
1834 	stats->misses = misses;
1835 }
1836 
1837 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)1838 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
1839 {
1840 	const struct bpf_prog *prog = filp->private_data;
1841 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
1842 	struct bpf_prog_stats stats;
1843 
1844 	bpf_prog_get_stats(prog, &stats);
1845 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
1846 	seq_printf(m,
1847 		   "prog_type:\t%u\n"
1848 		   "prog_jited:\t%u\n"
1849 		   "prog_tag:\t%s\n"
1850 		   "memlock:\t%llu\n"
1851 		   "prog_id:\t%u\n"
1852 		   "run_time_ns:\t%llu\n"
1853 		   "run_cnt:\t%llu\n"
1854 		   "recursion_misses:\t%llu\n",
1855 		   prog->type,
1856 		   prog->jited,
1857 		   prog_tag,
1858 		   prog->pages * 1ULL << PAGE_SHIFT,
1859 		   prog->aux->id,
1860 		   stats.nsecs,
1861 		   stats.cnt,
1862 		   stats.misses);
1863 }
1864 #endif
1865 
1866 const struct file_operations bpf_prog_fops = {
1867 #ifdef CONFIG_PROC_FS
1868 	.show_fdinfo	= bpf_prog_show_fdinfo,
1869 #endif
1870 	.release	= bpf_prog_release,
1871 	.read		= bpf_dummy_read,
1872 	.write		= bpf_dummy_write,
1873 };
1874 
bpf_prog_new_fd(struct bpf_prog * prog)1875 int bpf_prog_new_fd(struct bpf_prog *prog)
1876 {
1877 	int ret;
1878 
1879 	ret = security_bpf_prog(prog);
1880 	if (ret < 0)
1881 		return ret;
1882 
1883 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
1884 				O_RDWR | O_CLOEXEC);
1885 }
1886 
____bpf_prog_get(struct fd f)1887 static struct bpf_prog *____bpf_prog_get(struct fd f)
1888 {
1889 	if (!f.file)
1890 		return ERR_PTR(-EBADF);
1891 	if (f.file->f_op != &bpf_prog_fops) {
1892 		fdput(f);
1893 		return ERR_PTR(-EINVAL);
1894 	}
1895 
1896 	return f.file->private_data;
1897 }
1898 
bpf_prog_add(struct bpf_prog * prog,int i)1899 void bpf_prog_add(struct bpf_prog *prog, int i)
1900 {
1901 	atomic64_add(i, &prog->aux->refcnt);
1902 }
1903 EXPORT_SYMBOL_GPL(bpf_prog_add);
1904 
bpf_prog_sub(struct bpf_prog * prog,int i)1905 void bpf_prog_sub(struct bpf_prog *prog, int i)
1906 {
1907 	/* Only to be used for undoing previous bpf_prog_add() in some
1908 	 * error path. We still know that another entity in our call
1909 	 * path holds a reference to the program, thus atomic_sub() can
1910 	 * be safely used in such cases!
1911 	 */
1912 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
1913 }
1914 EXPORT_SYMBOL_GPL(bpf_prog_sub);
1915 
bpf_prog_inc(struct bpf_prog * prog)1916 void bpf_prog_inc(struct bpf_prog *prog)
1917 {
1918 	atomic64_inc(&prog->aux->refcnt);
1919 }
1920 EXPORT_SYMBOL_GPL(bpf_prog_inc);
1921 
1922 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)1923 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
1924 {
1925 	int refold;
1926 
1927 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
1928 
1929 	if (!refold)
1930 		return ERR_PTR(-ENOENT);
1931 
1932 	return prog;
1933 }
1934 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
1935 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)1936 bool bpf_prog_get_ok(struct bpf_prog *prog,
1937 			    enum bpf_prog_type *attach_type, bool attach_drv)
1938 {
1939 	/* not an attachment, just a refcount inc, always allow */
1940 	if (!attach_type)
1941 		return true;
1942 
1943 	if (prog->type != *attach_type)
1944 		return false;
1945 	if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
1946 		return false;
1947 
1948 	return true;
1949 }
1950 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)1951 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
1952 				       bool attach_drv)
1953 {
1954 	struct fd f = fdget(ufd);
1955 	struct bpf_prog *prog;
1956 
1957 	prog = ____bpf_prog_get(f);
1958 	if (IS_ERR(prog))
1959 		return prog;
1960 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
1961 		prog = ERR_PTR(-EINVAL);
1962 		goto out;
1963 	}
1964 
1965 	bpf_prog_inc(prog);
1966 out:
1967 	fdput(f);
1968 	return prog;
1969 }
1970 
bpf_prog_get(u32 ufd)1971 struct bpf_prog *bpf_prog_get(u32 ufd)
1972 {
1973 	return __bpf_prog_get(ufd, NULL, false);
1974 }
1975 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)1976 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
1977 				       bool attach_drv)
1978 {
1979 	return __bpf_prog_get(ufd, &type, attach_drv);
1980 }
1981 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
1982 
1983 /* Initially all BPF programs could be loaded w/o specifying
1984  * expected_attach_type. Later for some of them specifying expected_attach_type
1985  * at load time became required so that program could be validated properly.
1986  * Programs of types that are allowed to be loaded both w/ and w/o (for
1987  * backward compatibility) expected_attach_type, should have the default attach
1988  * type assigned to expected_attach_type for the latter case, so that it can be
1989  * validated later at attach time.
1990  *
1991  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
1992  * prog type requires it but has some attach types that have to be backward
1993  * compatible.
1994  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)1995 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
1996 {
1997 	switch (attr->prog_type) {
1998 	case BPF_PROG_TYPE_CGROUP_SOCK:
1999 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2000 		 * exist so checking for non-zero is the way to go here.
2001 		 */
2002 		if (!attr->expected_attach_type)
2003 			attr->expected_attach_type =
2004 				BPF_CGROUP_INET_SOCK_CREATE;
2005 		break;
2006 	case BPF_PROG_TYPE_SK_REUSEPORT:
2007 		if (!attr->expected_attach_type)
2008 			attr->expected_attach_type =
2009 				BPF_SK_REUSEPORT_SELECT;
2010 		break;
2011 	}
2012 }
2013 
2014 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)2015 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2016 			   enum bpf_attach_type expected_attach_type,
2017 			   struct btf *attach_btf, u32 btf_id,
2018 			   struct bpf_prog *dst_prog)
2019 {
2020 	if (btf_id) {
2021 		if (btf_id > BTF_MAX_TYPE)
2022 			return -EINVAL;
2023 
2024 		if (!attach_btf && !dst_prog)
2025 			return -EINVAL;
2026 
2027 		switch (prog_type) {
2028 		case BPF_PROG_TYPE_TRACING:
2029 		case BPF_PROG_TYPE_LSM:
2030 		case BPF_PROG_TYPE_STRUCT_OPS:
2031 		case BPF_PROG_TYPE_EXT:
2032 			break;
2033 		default:
2034 			return -EINVAL;
2035 		}
2036 	}
2037 
2038 	if (attach_btf && (!btf_id || dst_prog))
2039 		return -EINVAL;
2040 
2041 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2042 	    prog_type != BPF_PROG_TYPE_EXT)
2043 		return -EINVAL;
2044 
2045 	switch (prog_type) {
2046 	case BPF_PROG_TYPE_CGROUP_SOCK:
2047 		switch (expected_attach_type) {
2048 		case BPF_CGROUP_INET_SOCK_CREATE:
2049 		case BPF_CGROUP_INET_SOCK_RELEASE:
2050 		case BPF_CGROUP_INET4_POST_BIND:
2051 		case BPF_CGROUP_INET6_POST_BIND:
2052 			return 0;
2053 		default:
2054 			return -EINVAL;
2055 		}
2056 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2057 		switch (expected_attach_type) {
2058 		case BPF_CGROUP_INET4_BIND:
2059 		case BPF_CGROUP_INET6_BIND:
2060 		case BPF_CGROUP_INET4_CONNECT:
2061 		case BPF_CGROUP_INET6_CONNECT:
2062 		case BPF_CGROUP_INET4_GETPEERNAME:
2063 		case BPF_CGROUP_INET6_GETPEERNAME:
2064 		case BPF_CGROUP_INET4_GETSOCKNAME:
2065 		case BPF_CGROUP_INET6_GETSOCKNAME:
2066 		case BPF_CGROUP_UDP4_SENDMSG:
2067 		case BPF_CGROUP_UDP6_SENDMSG:
2068 		case BPF_CGROUP_UDP4_RECVMSG:
2069 		case BPF_CGROUP_UDP6_RECVMSG:
2070 			return 0;
2071 		default:
2072 			return -EINVAL;
2073 		}
2074 	case BPF_PROG_TYPE_CGROUP_SKB:
2075 		switch (expected_attach_type) {
2076 		case BPF_CGROUP_INET_INGRESS:
2077 		case BPF_CGROUP_INET_EGRESS:
2078 			return 0;
2079 		default:
2080 			return -EINVAL;
2081 		}
2082 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2083 		switch (expected_attach_type) {
2084 		case BPF_CGROUP_SETSOCKOPT:
2085 		case BPF_CGROUP_GETSOCKOPT:
2086 			return 0;
2087 		default:
2088 			return -EINVAL;
2089 		}
2090 	case BPF_PROG_TYPE_SK_LOOKUP:
2091 		if (expected_attach_type == BPF_SK_LOOKUP)
2092 			return 0;
2093 		return -EINVAL;
2094 	case BPF_PROG_TYPE_SK_REUSEPORT:
2095 		switch (expected_attach_type) {
2096 		case BPF_SK_REUSEPORT_SELECT:
2097 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2098 			return 0;
2099 		default:
2100 			return -EINVAL;
2101 		}
2102 	case BPF_PROG_TYPE_SYSCALL:
2103 	case BPF_PROG_TYPE_EXT:
2104 		if (expected_attach_type)
2105 			return -EINVAL;
2106 		fallthrough;
2107 	default:
2108 		return 0;
2109 	}
2110 }
2111 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2112 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2113 {
2114 	switch (prog_type) {
2115 	case BPF_PROG_TYPE_SCHED_CLS:
2116 	case BPF_PROG_TYPE_SCHED_ACT:
2117 	case BPF_PROG_TYPE_XDP:
2118 	case BPF_PROG_TYPE_LWT_IN:
2119 	case BPF_PROG_TYPE_LWT_OUT:
2120 	case BPF_PROG_TYPE_LWT_XMIT:
2121 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2122 	case BPF_PROG_TYPE_SK_SKB:
2123 	case BPF_PROG_TYPE_SK_MSG:
2124 	case BPF_PROG_TYPE_LIRC_MODE2:
2125 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2126 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2127 	case BPF_PROG_TYPE_CGROUP_SOCK:
2128 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2129 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2130 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2131 	case BPF_PROG_TYPE_SOCK_OPS:
2132 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2133 		return true;
2134 	case BPF_PROG_TYPE_CGROUP_SKB:
2135 		/* always unpriv */
2136 	case BPF_PROG_TYPE_SK_REUSEPORT:
2137 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2138 	default:
2139 		return false;
2140 	}
2141 }
2142 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2143 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2144 {
2145 	switch (prog_type) {
2146 	case BPF_PROG_TYPE_KPROBE:
2147 	case BPF_PROG_TYPE_TRACEPOINT:
2148 	case BPF_PROG_TYPE_PERF_EVENT:
2149 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2150 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2151 	case BPF_PROG_TYPE_TRACING:
2152 	case BPF_PROG_TYPE_LSM:
2153 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2154 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2155 		return true;
2156 	default:
2157 		return false;
2158 	}
2159 }
2160 
2161 /* last field in 'union bpf_attr' used by this command */
2162 #define	BPF_PROG_LOAD_LAST_FIELD fd_array
2163 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr)2164 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
2165 {
2166 	enum bpf_prog_type type = attr->prog_type;
2167 	struct bpf_prog *prog, *dst_prog = NULL;
2168 	struct btf *attach_btf = NULL;
2169 	int err;
2170 	char license[128];
2171 	bool is_gpl;
2172 
2173 	if (CHECK_ATTR(BPF_PROG_LOAD))
2174 		return -EINVAL;
2175 
2176 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2177 				 BPF_F_ANY_ALIGNMENT |
2178 				 BPF_F_TEST_STATE_FREQ |
2179 				 BPF_F_SLEEPABLE |
2180 				 BPF_F_TEST_RND_HI32))
2181 		return -EINVAL;
2182 
2183 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2184 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2185 	    !bpf_capable())
2186 		return -EPERM;
2187 
2188 	/* copy eBPF program license from user space */
2189 	if (strncpy_from_bpfptr(license,
2190 				make_bpfptr(attr->license, uattr.is_kernel),
2191 				sizeof(license) - 1) < 0)
2192 		return -EFAULT;
2193 	license[sizeof(license) - 1] = 0;
2194 
2195 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
2196 	is_gpl = license_is_gpl_compatible(license);
2197 
2198 	if (attr->insn_cnt == 0 ||
2199 	    attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
2200 		return -E2BIG;
2201 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2202 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2203 	    !bpf_capable())
2204 		return -EPERM;
2205 
2206 	if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
2207 		return -EPERM;
2208 	if (is_perfmon_prog_type(type) && !perfmon_capable())
2209 		return -EPERM;
2210 
2211 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2212 	 * or btf, we need to check which one it is
2213 	 */
2214 	if (attr->attach_prog_fd) {
2215 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2216 		if (IS_ERR(dst_prog)) {
2217 			dst_prog = NULL;
2218 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2219 			if (IS_ERR(attach_btf))
2220 				return -EINVAL;
2221 			if (!btf_is_kernel(attach_btf)) {
2222 				/* attaching through specifying bpf_prog's BTF
2223 				 * objects directly might be supported eventually
2224 				 */
2225 				btf_put(attach_btf);
2226 				return -ENOTSUPP;
2227 			}
2228 		}
2229 	} else if (attr->attach_btf_id) {
2230 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2231 		attach_btf = bpf_get_btf_vmlinux();
2232 		if (IS_ERR(attach_btf))
2233 			return PTR_ERR(attach_btf);
2234 		if (!attach_btf)
2235 			return -EINVAL;
2236 		btf_get(attach_btf);
2237 	}
2238 
2239 	bpf_prog_load_fixup_attach_type(attr);
2240 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2241 				       attach_btf, attr->attach_btf_id,
2242 				       dst_prog)) {
2243 		if (dst_prog)
2244 			bpf_prog_put(dst_prog);
2245 		if (attach_btf)
2246 			btf_put(attach_btf);
2247 		return -EINVAL;
2248 	}
2249 
2250 	/* plain bpf_prog allocation */
2251 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2252 	if (!prog) {
2253 		if (dst_prog)
2254 			bpf_prog_put(dst_prog);
2255 		if (attach_btf)
2256 			btf_put(attach_btf);
2257 		return -ENOMEM;
2258 	}
2259 
2260 	prog->expected_attach_type = attr->expected_attach_type;
2261 	prog->aux->attach_btf = attach_btf;
2262 	prog->aux->attach_btf_id = attr->attach_btf_id;
2263 	prog->aux->dst_prog = dst_prog;
2264 	prog->aux->offload_requested = !!attr->prog_ifindex;
2265 	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
2266 
2267 	err = security_bpf_prog_alloc(prog->aux);
2268 	if (err)
2269 		goto free_prog;
2270 
2271 	prog->aux->user = get_current_user();
2272 	prog->len = attr->insn_cnt;
2273 
2274 	err = -EFAULT;
2275 	if (copy_from_bpfptr(prog->insns,
2276 			     make_bpfptr(attr->insns, uattr.is_kernel),
2277 			     bpf_prog_insn_size(prog)) != 0)
2278 		goto free_prog_sec;
2279 
2280 	prog->orig_prog = NULL;
2281 	prog->jited = 0;
2282 
2283 	atomic64_set(&prog->aux->refcnt, 1);
2284 	prog->gpl_compatible = is_gpl ? 1 : 0;
2285 
2286 	if (bpf_prog_is_dev_bound(prog->aux)) {
2287 		err = bpf_prog_offload_init(prog, attr);
2288 		if (err)
2289 			goto free_prog_sec;
2290 	}
2291 
2292 	/* find program type: socket_filter vs tracing_filter */
2293 	err = find_prog_type(type, prog);
2294 	if (err < 0)
2295 		goto free_prog_sec;
2296 
2297 	prog->aux->load_time = ktime_get_boottime_ns();
2298 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2299 			       sizeof(attr->prog_name));
2300 	if (err < 0)
2301 		goto free_prog_sec;
2302 
2303 	/* run eBPF verifier */
2304 	err = bpf_check(&prog, attr, uattr);
2305 	if (err < 0)
2306 		goto free_used_maps;
2307 
2308 	prog = bpf_prog_select_runtime(prog, &err);
2309 	if (err < 0)
2310 		goto free_used_maps;
2311 
2312 	err = bpf_prog_alloc_id(prog);
2313 	if (err)
2314 		goto free_used_maps;
2315 
2316 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
2317 	 * effectively publicly exposed. However, retrieving via
2318 	 * bpf_prog_get_fd_by_id() will take another reference,
2319 	 * therefore it cannot be gone underneath us.
2320 	 *
2321 	 * Only for the time /after/ successful bpf_prog_new_fd()
2322 	 * and before returning to userspace, we might just hold
2323 	 * one reference and any parallel close on that fd could
2324 	 * rip everything out. Hence, below notifications must
2325 	 * happen before bpf_prog_new_fd().
2326 	 *
2327 	 * Also, any failure handling from this point onwards must
2328 	 * be using bpf_prog_put() given the program is exposed.
2329 	 */
2330 	bpf_prog_kallsyms_add(prog);
2331 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2332 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
2333 
2334 	err = bpf_prog_new_fd(prog);
2335 	if (err < 0)
2336 		bpf_prog_put(prog);
2337 	return err;
2338 
2339 free_used_maps:
2340 	/* In case we have subprogs, we need to wait for a grace
2341 	 * period before we can tear down JIT memory since symbols
2342 	 * are already exposed under kallsyms.
2343 	 */
2344 	__bpf_prog_put_noref(prog, prog->aux->func_cnt);
2345 	return err;
2346 free_prog_sec:
2347 	free_uid(prog->aux->user);
2348 	security_bpf_prog_free(prog->aux);
2349 free_prog:
2350 	if (prog->aux->attach_btf)
2351 		btf_put(prog->aux->attach_btf);
2352 	bpf_prog_free(prog);
2353 	return err;
2354 }
2355 
2356 #define BPF_OBJ_LAST_FIELD file_flags
2357 
bpf_obj_pin(const union bpf_attr * attr)2358 static int bpf_obj_pin(const union bpf_attr *attr)
2359 {
2360 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
2361 		return -EINVAL;
2362 
2363 	return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
2364 }
2365 
bpf_obj_get(const union bpf_attr * attr)2366 static int bpf_obj_get(const union bpf_attr *attr)
2367 {
2368 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
2369 	    attr->file_flags & ~BPF_OBJ_FLAG_MASK)
2370 		return -EINVAL;
2371 
2372 	return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
2373 				attr->file_flags);
2374 }
2375 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)2376 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
2377 		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
2378 {
2379 	atomic64_set(&link->refcnt, 1);
2380 	link->type = type;
2381 	link->id = 0;
2382 	link->ops = ops;
2383 	link->prog = prog;
2384 }
2385 
bpf_link_free_id(int id)2386 static void bpf_link_free_id(int id)
2387 {
2388 	if (!id)
2389 		return;
2390 
2391 	spin_lock_bh(&link_idr_lock);
2392 	idr_remove(&link_idr, id);
2393 	spin_unlock_bh(&link_idr_lock);
2394 }
2395 
2396 /* Clean up bpf_link and corresponding anon_inode file and FD. After
2397  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
2398  * anon_inode's release() call. This helper marksbpf_link as
2399  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
2400  * is not decremented, it's the responsibility of a calling code that failed
2401  * to complete bpf_link initialization.
2402  */
bpf_link_cleanup(struct bpf_link_primer * primer)2403 void bpf_link_cleanup(struct bpf_link_primer *primer)
2404 {
2405 	primer->link->prog = NULL;
2406 	bpf_link_free_id(primer->id);
2407 	fput(primer->file);
2408 	put_unused_fd(primer->fd);
2409 }
2410 
bpf_link_inc(struct bpf_link * link)2411 void bpf_link_inc(struct bpf_link *link)
2412 {
2413 	atomic64_inc(&link->refcnt);
2414 }
2415 
2416 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)2417 static void bpf_link_free(struct bpf_link *link)
2418 {
2419 	bpf_link_free_id(link->id);
2420 	if (link->prog) {
2421 		/* detach BPF program, clean up used resources */
2422 		link->ops->release(link);
2423 		bpf_prog_put(link->prog);
2424 	}
2425 	/* free bpf_link and its containing memory */
2426 	link->ops->dealloc(link);
2427 }
2428 
bpf_link_put_deferred(struct work_struct * work)2429 static void bpf_link_put_deferred(struct work_struct *work)
2430 {
2431 	struct bpf_link *link = container_of(work, struct bpf_link, work);
2432 
2433 	bpf_link_free(link);
2434 }
2435 
2436 /* bpf_link_put can be called from atomic context, but ensures that resources
2437  * are freed from process context
2438  */
bpf_link_put(struct bpf_link * link)2439 void bpf_link_put(struct bpf_link *link)
2440 {
2441 	if (!atomic64_dec_and_test(&link->refcnt))
2442 		return;
2443 
2444 	if (in_atomic()) {
2445 		INIT_WORK(&link->work, bpf_link_put_deferred);
2446 		schedule_work(&link->work);
2447 	} else {
2448 		bpf_link_free(link);
2449 	}
2450 }
2451 
bpf_link_release(struct inode * inode,struct file * filp)2452 static int bpf_link_release(struct inode *inode, struct file *filp)
2453 {
2454 	struct bpf_link *link = filp->private_data;
2455 
2456 	bpf_link_put(link);
2457 	return 0;
2458 }
2459 
2460 #ifdef CONFIG_PROC_FS
2461 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
2462 #define BPF_MAP_TYPE(_id, _ops)
2463 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
2464 static const char *bpf_link_type_strs[] = {
2465 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
2466 #include <linux/bpf_types.h>
2467 };
2468 #undef BPF_PROG_TYPE
2469 #undef BPF_MAP_TYPE
2470 #undef BPF_LINK_TYPE
2471 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)2472 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
2473 {
2474 	const struct bpf_link *link = filp->private_data;
2475 	const struct bpf_prog *prog = link->prog;
2476 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2477 
2478 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2479 	seq_printf(m,
2480 		   "link_type:\t%s\n"
2481 		   "link_id:\t%u\n"
2482 		   "prog_tag:\t%s\n"
2483 		   "prog_id:\t%u\n",
2484 		   bpf_link_type_strs[link->type],
2485 		   link->id,
2486 		   prog_tag,
2487 		   prog->aux->id);
2488 	if (link->ops->show_fdinfo)
2489 		link->ops->show_fdinfo(link, m);
2490 }
2491 #endif
2492 
2493 static const struct file_operations bpf_link_fops = {
2494 #ifdef CONFIG_PROC_FS
2495 	.show_fdinfo	= bpf_link_show_fdinfo,
2496 #endif
2497 	.release	= bpf_link_release,
2498 	.read		= bpf_dummy_read,
2499 	.write		= bpf_dummy_write,
2500 };
2501 
bpf_link_alloc_id(struct bpf_link * link)2502 static int bpf_link_alloc_id(struct bpf_link *link)
2503 {
2504 	int id;
2505 
2506 	idr_preload(GFP_KERNEL);
2507 	spin_lock_bh(&link_idr_lock);
2508 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
2509 	spin_unlock_bh(&link_idr_lock);
2510 	idr_preload_end();
2511 
2512 	return id;
2513 }
2514 
2515 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
2516  * reserving unused FD and allocating ID from link_idr. This is to be paired
2517  * with bpf_link_settle() to install FD and ID and expose bpf_link to
2518  * user-space, if bpf_link is successfully attached. If not, bpf_link and
2519  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
2520  * transient state is passed around in struct bpf_link_primer.
2521  * This is preferred way to create and initialize bpf_link, especially when
2522  * there are complicated and expensive operations inbetween creating bpf_link
2523  * itself and attaching it to BPF hook. By using bpf_link_prime() and
2524  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
2525  * expensive (and potentially failing) roll back operations in a rare case
2526  * that file, FD, or ID can't be allocated.
2527  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)2528 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
2529 {
2530 	struct file *file;
2531 	int fd, id;
2532 
2533 	fd = get_unused_fd_flags(O_CLOEXEC);
2534 	if (fd < 0)
2535 		return fd;
2536 
2537 
2538 	id = bpf_link_alloc_id(link);
2539 	if (id < 0) {
2540 		put_unused_fd(fd);
2541 		return id;
2542 	}
2543 
2544 	file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
2545 	if (IS_ERR(file)) {
2546 		bpf_link_free_id(id);
2547 		put_unused_fd(fd);
2548 		return PTR_ERR(file);
2549 	}
2550 
2551 	primer->link = link;
2552 	primer->file = file;
2553 	primer->fd = fd;
2554 	primer->id = id;
2555 	return 0;
2556 }
2557 
bpf_link_settle(struct bpf_link_primer * primer)2558 int bpf_link_settle(struct bpf_link_primer *primer)
2559 {
2560 	/* make bpf_link fetchable by ID */
2561 	spin_lock_bh(&link_idr_lock);
2562 	primer->link->id = primer->id;
2563 	spin_unlock_bh(&link_idr_lock);
2564 	/* make bpf_link fetchable by FD */
2565 	fd_install(primer->fd, primer->file);
2566 	/* pass through installed FD */
2567 	return primer->fd;
2568 }
2569 
bpf_link_new_fd(struct bpf_link * link)2570 int bpf_link_new_fd(struct bpf_link *link)
2571 {
2572 	return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
2573 }
2574 
bpf_link_get_from_fd(u32 ufd)2575 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
2576 {
2577 	struct fd f = fdget(ufd);
2578 	struct bpf_link *link;
2579 
2580 	if (!f.file)
2581 		return ERR_PTR(-EBADF);
2582 	if (f.file->f_op != &bpf_link_fops) {
2583 		fdput(f);
2584 		return ERR_PTR(-EINVAL);
2585 	}
2586 
2587 	link = f.file->private_data;
2588 	bpf_link_inc(link);
2589 	fdput(f);
2590 
2591 	return link;
2592 }
2593 
2594 struct bpf_tracing_link {
2595 	struct bpf_link link;
2596 	enum bpf_attach_type attach_type;
2597 	struct bpf_trampoline *trampoline;
2598 	struct bpf_prog *tgt_prog;
2599 };
2600 
bpf_tracing_link_release(struct bpf_link * link)2601 static void bpf_tracing_link_release(struct bpf_link *link)
2602 {
2603 	struct bpf_tracing_link *tr_link =
2604 		container_of(link, struct bpf_tracing_link, link);
2605 
2606 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->prog,
2607 						tr_link->trampoline));
2608 
2609 	bpf_trampoline_put(tr_link->trampoline);
2610 
2611 	/* tgt_prog is NULL if target is a kernel function */
2612 	if (tr_link->tgt_prog)
2613 		bpf_prog_put(tr_link->tgt_prog);
2614 }
2615 
bpf_tracing_link_dealloc(struct bpf_link * link)2616 static void bpf_tracing_link_dealloc(struct bpf_link *link)
2617 {
2618 	struct bpf_tracing_link *tr_link =
2619 		container_of(link, struct bpf_tracing_link, link);
2620 
2621 	kfree(tr_link);
2622 }
2623 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)2624 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
2625 					 struct seq_file *seq)
2626 {
2627 	struct bpf_tracing_link *tr_link =
2628 		container_of(link, struct bpf_tracing_link, link);
2629 
2630 	seq_printf(seq,
2631 		   "attach_type:\t%d\n",
2632 		   tr_link->attach_type);
2633 }
2634 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2635 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
2636 					   struct bpf_link_info *info)
2637 {
2638 	struct bpf_tracing_link *tr_link =
2639 		container_of(link, struct bpf_tracing_link, link);
2640 
2641 	info->tracing.attach_type = tr_link->attach_type;
2642 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
2643 				  &info->tracing.target_obj_id,
2644 				  &info->tracing.target_btf_id);
2645 
2646 	return 0;
2647 }
2648 
2649 static const struct bpf_link_ops bpf_tracing_link_lops = {
2650 	.release = bpf_tracing_link_release,
2651 	.dealloc = bpf_tracing_link_dealloc,
2652 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
2653 	.fill_link_info = bpf_tracing_link_fill_link_info,
2654 };
2655 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id)2656 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
2657 				   int tgt_prog_fd,
2658 				   u32 btf_id)
2659 {
2660 	struct bpf_link_primer link_primer;
2661 	struct bpf_prog *tgt_prog = NULL;
2662 	struct bpf_trampoline *tr = NULL;
2663 	struct bpf_tracing_link *link;
2664 	u64 key = 0;
2665 	int err;
2666 
2667 	switch (prog->type) {
2668 	case BPF_PROG_TYPE_TRACING:
2669 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
2670 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
2671 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
2672 			err = -EINVAL;
2673 			goto out_put_prog;
2674 		}
2675 		break;
2676 	case BPF_PROG_TYPE_EXT:
2677 		if (prog->expected_attach_type != 0) {
2678 			err = -EINVAL;
2679 			goto out_put_prog;
2680 		}
2681 		break;
2682 	case BPF_PROG_TYPE_LSM:
2683 		if (prog->expected_attach_type != BPF_LSM_MAC) {
2684 			err = -EINVAL;
2685 			goto out_put_prog;
2686 		}
2687 		break;
2688 	default:
2689 		err = -EINVAL;
2690 		goto out_put_prog;
2691 	}
2692 
2693 	if (!!tgt_prog_fd != !!btf_id) {
2694 		err = -EINVAL;
2695 		goto out_put_prog;
2696 	}
2697 
2698 	if (tgt_prog_fd) {
2699 		/* For now we only allow new targets for BPF_PROG_TYPE_EXT */
2700 		if (prog->type != BPF_PROG_TYPE_EXT) {
2701 			err = -EINVAL;
2702 			goto out_put_prog;
2703 		}
2704 
2705 		tgt_prog = bpf_prog_get(tgt_prog_fd);
2706 		if (IS_ERR(tgt_prog)) {
2707 			err = PTR_ERR(tgt_prog);
2708 			tgt_prog = NULL;
2709 			goto out_put_prog;
2710 		}
2711 
2712 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
2713 	}
2714 
2715 	link = kzalloc(sizeof(*link), GFP_USER);
2716 	if (!link) {
2717 		err = -ENOMEM;
2718 		goto out_put_prog;
2719 	}
2720 	bpf_link_init(&link->link, BPF_LINK_TYPE_TRACING,
2721 		      &bpf_tracing_link_lops, prog);
2722 	link->attach_type = prog->expected_attach_type;
2723 
2724 	mutex_lock(&prog->aux->dst_mutex);
2725 
2726 	/* There are a few possible cases here:
2727 	 *
2728 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
2729 	 *   and not yet attached to anything, so we can use the values stored
2730 	 *   in prog->aux
2731 	 *
2732 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
2733          *   attached to a target and its initial target was cleared (below)
2734 	 *
2735 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
2736 	 *   target_btf_id using the link_create API.
2737 	 *
2738 	 * - if tgt_prog == NULL when this function was called using the old
2739 	 *   raw_tracepoint_open API, and we need a target from prog->aux
2740 	 *
2741 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
2742 	 *   was detached and is going for re-attachment.
2743 	 */
2744 	if (!prog->aux->dst_trampoline && !tgt_prog) {
2745 		/*
2746 		 * Allow re-attach for TRACING and LSM programs. If it's
2747 		 * currently linked, bpf_trampoline_link_prog will fail.
2748 		 * EXT programs need to specify tgt_prog_fd, so they
2749 		 * re-attach in separate code path.
2750 		 */
2751 		if (prog->type != BPF_PROG_TYPE_TRACING &&
2752 		    prog->type != BPF_PROG_TYPE_LSM) {
2753 			err = -EINVAL;
2754 			goto out_unlock;
2755 		}
2756 		btf_id = prog->aux->attach_btf_id;
2757 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
2758 	}
2759 
2760 	if (!prog->aux->dst_trampoline ||
2761 	    (key && key != prog->aux->dst_trampoline->key)) {
2762 		/* If there is no saved target, or the specified target is
2763 		 * different from the destination specified at load time, we
2764 		 * need a new trampoline and a check for compatibility
2765 		 */
2766 		struct bpf_attach_target_info tgt_info = {};
2767 
2768 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
2769 					      &tgt_info);
2770 		if (err)
2771 			goto out_unlock;
2772 
2773 		tr = bpf_trampoline_get(key, &tgt_info);
2774 		if (!tr) {
2775 			err = -ENOMEM;
2776 			goto out_unlock;
2777 		}
2778 	} else {
2779 		/* The caller didn't specify a target, or the target was the
2780 		 * same as the destination supplied during program load. This
2781 		 * means we can reuse the trampoline and reference from program
2782 		 * load time, and there is no need to allocate a new one. This
2783 		 * can only happen once for any program, as the saved values in
2784 		 * prog->aux are cleared below.
2785 		 */
2786 		tr = prog->aux->dst_trampoline;
2787 		tgt_prog = prog->aux->dst_prog;
2788 	}
2789 
2790 	err = bpf_link_prime(&link->link, &link_primer);
2791 	if (err)
2792 		goto out_unlock;
2793 
2794 	err = bpf_trampoline_link_prog(prog, tr);
2795 	if (err) {
2796 		bpf_link_cleanup(&link_primer);
2797 		link = NULL;
2798 		goto out_unlock;
2799 	}
2800 
2801 	link->tgt_prog = tgt_prog;
2802 	link->trampoline = tr;
2803 
2804 	/* Always clear the trampoline and target prog from prog->aux to make
2805 	 * sure the original attach destination is not kept alive after a
2806 	 * program is (re-)attached to another target.
2807 	 */
2808 	if (prog->aux->dst_prog &&
2809 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
2810 		/* got extra prog ref from syscall, or attaching to different prog */
2811 		bpf_prog_put(prog->aux->dst_prog);
2812 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
2813 		/* we allocated a new trampoline, so free the old one */
2814 		bpf_trampoline_put(prog->aux->dst_trampoline);
2815 
2816 	prog->aux->dst_prog = NULL;
2817 	prog->aux->dst_trampoline = NULL;
2818 	mutex_unlock(&prog->aux->dst_mutex);
2819 
2820 	return bpf_link_settle(&link_primer);
2821 out_unlock:
2822 	if (tr && tr != prog->aux->dst_trampoline)
2823 		bpf_trampoline_put(tr);
2824 	mutex_unlock(&prog->aux->dst_mutex);
2825 	kfree(link);
2826 out_put_prog:
2827 	if (tgt_prog_fd && tgt_prog)
2828 		bpf_prog_put(tgt_prog);
2829 	return err;
2830 }
2831 
2832 struct bpf_raw_tp_link {
2833 	struct bpf_link link;
2834 	struct bpf_raw_event_map *btp;
2835 };
2836 
bpf_raw_tp_link_release(struct bpf_link * link)2837 static void bpf_raw_tp_link_release(struct bpf_link *link)
2838 {
2839 	struct bpf_raw_tp_link *raw_tp =
2840 		container_of(link, struct bpf_raw_tp_link, link);
2841 
2842 	bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
2843 	bpf_put_raw_tracepoint(raw_tp->btp);
2844 }
2845 
bpf_raw_tp_link_dealloc(struct bpf_link * link)2846 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
2847 {
2848 	struct bpf_raw_tp_link *raw_tp =
2849 		container_of(link, struct bpf_raw_tp_link, link);
2850 
2851 	kfree(raw_tp);
2852 }
2853 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)2854 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
2855 					struct seq_file *seq)
2856 {
2857 	struct bpf_raw_tp_link *raw_tp_link =
2858 		container_of(link, struct bpf_raw_tp_link, link);
2859 
2860 	seq_printf(seq,
2861 		   "tp_name:\t%s\n",
2862 		   raw_tp_link->btp->tp->name);
2863 }
2864 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2865 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
2866 					  struct bpf_link_info *info)
2867 {
2868 	struct bpf_raw_tp_link *raw_tp_link =
2869 		container_of(link, struct bpf_raw_tp_link, link);
2870 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
2871 	const char *tp_name = raw_tp_link->btp->tp->name;
2872 	u32 ulen = info->raw_tracepoint.tp_name_len;
2873 	size_t tp_len = strlen(tp_name);
2874 
2875 	if (!ulen ^ !ubuf)
2876 		return -EINVAL;
2877 
2878 	info->raw_tracepoint.tp_name_len = tp_len + 1;
2879 
2880 	if (!ubuf)
2881 		return 0;
2882 
2883 	if (ulen >= tp_len + 1) {
2884 		if (copy_to_user(ubuf, tp_name, tp_len + 1))
2885 			return -EFAULT;
2886 	} else {
2887 		char zero = '\0';
2888 
2889 		if (copy_to_user(ubuf, tp_name, ulen - 1))
2890 			return -EFAULT;
2891 		if (put_user(zero, ubuf + ulen - 1))
2892 			return -EFAULT;
2893 		return -ENOSPC;
2894 	}
2895 
2896 	return 0;
2897 }
2898 
2899 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
2900 	.release = bpf_raw_tp_link_release,
2901 	.dealloc = bpf_raw_tp_link_dealloc,
2902 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
2903 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
2904 };
2905 
2906 #ifdef CONFIG_PERF_EVENTS
2907 struct bpf_perf_link {
2908 	struct bpf_link link;
2909 	struct file *perf_file;
2910 };
2911 
bpf_perf_link_release(struct bpf_link * link)2912 static void bpf_perf_link_release(struct bpf_link *link)
2913 {
2914 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
2915 	struct perf_event *event = perf_link->perf_file->private_data;
2916 
2917 	perf_event_free_bpf_prog(event);
2918 	fput(perf_link->perf_file);
2919 }
2920 
bpf_perf_link_dealloc(struct bpf_link * link)2921 static void bpf_perf_link_dealloc(struct bpf_link *link)
2922 {
2923 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
2924 
2925 	kfree(perf_link);
2926 }
2927 
2928 static const struct bpf_link_ops bpf_perf_link_lops = {
2929 	.release = bpf_perf_link_release,
2930 	.dealloc = bpf_perf_link_dealloc,
2931 };
2932 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2933 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2934 {
2935 	struct bpf_link_primer link_primer;
2936 	struct bpf_perf_link *link;
2937 	struct perf_event *event;
2938 	struct file *perf_file;
2939 	int err;
2940 
2941 	if (attr->link_create.flags)
2942 		return -EINVAL;
2943 
2944 	perf_file = perf_event_get(attr->link_create.target_fd);
2945 	if (IS_ERR(perf_file))
2946 		return PTR_ERR(perf_file);
2947 
2948 	link = kzalloc(sizeof(*link), GFP_USER);
2949 	if (!link) {
2950 		err = -ENOMEM;
2951 		goto out_put_file;
2952 	}
2953 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
2954 	link->perf_file = perf_file;
2955 
2956 	err = bpf_link_prime(&link->link, &link_primer);
2957 	if (err) {
2958 		kfree(link);
2959 		goto out_put_file;
2960 	}
2961 
2962 	event = perf_file->private_data;
2963 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
2964 	if (err) {
2965 		bpf_link_cleanup(&link_primer);
2966 		goto out_put_file;
2967 	}
2968 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
2969 	bpf_prog_inc(prog);
2970 
2971 	return bpf_link_settle(&link_primer);
2972 
2973 out_put_file:
2974 	fput(perf_file);
2975 	return err;
2976 }
2977 #endif /* CONFIG_PERF_EVENTS */
2978 
2979 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
2980 
bpf_raw_tracepoint_open(const union bpf_attr * attr)2981 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
2982 {
2983 	struct bpf_link_primer link_primer;
2984 	struct bpf_raw_tp_link *link;
2985 	struct bpf_raw_event_map *btp;
2986 	struct bpf_prog *prog;
2987 	const char *tp_name;
2988 	char buf[128];
2989 	int err;
2990 
2991 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
2992 		return -EINVAL;
2993 
2994 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
2995 	if (IS_ERR(prog))
2996 		return PTR_ERR(prog);
2997 
2998 	switch (prog->type) {
2999 	case BPF_PROG_TYPE_TRACING:
3000 	case BPF_PROG_TYPE_EXT:
3001 	case BPF_PROG_TYPE_LSM:
3002 		if (attr->raw_tracepoint.name) {
3003 			/* The attach point for this category of programs
3004 			 * should be specified via btf_id during program load.
3005 			 */
3006 			err = -EINVAL;
3007 			goto out_put_prog;
3008 		}
3009 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3010 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3011 			tp_name = prog->aux->attach_func_name;
3012 			break;
3013 		}
3014 		err = bpf_tracing_prog_attach(prog, 0, 0);
3015 		if (err >= 0)
3016 			return err;
3017 		goto out_put_prog;
3018 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3019 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3020 		if (strncpy_from_user(buf,
3021 				      u64_to_user_ptr(attr->raw_tracepoint.name),
3022 				      sizeof(buf) - 1) < 0) {
3023 			err = -EFAULT;
3024 			goto out_put_prog;
3025 		}
3026 		buf[sizeof(buf) - 1] = 0;
3027 		tp_name = buf;
3028 		break;
3029 	default:
3030 		err = -EINVAL;
3031 		goto out_put_prog;
3032 	}
3033 
3034 	btp = bpf_get_raw_tracepoint(tp_name);
3035 	if (!btp) {
3036 		err = -ENOENT;
3037 		goto out_put_prog;
3038 	}
3039 
3040 	link = kzalloc(sizeof(*link), GFP_USER);
3041 	if (!link) {
3042 		err = -ENOMEM;
3043 		goto out_put_btp;
3044 	}
3045 	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3046 		      &bpf_raw_tp_link_lops, prog);
3047 	link->btp = btp;
3048 
3049 	err = bpf_link_prime(&link->link, &link_primer);
3050 	if (err) {
3051 		kfree(link);
3052 		goto out_put_btp;
3053 	}
3054 
3055 	err = bpf_probe_register(link->btp, prog);
3056 	if (err) {
3057 		bpf_link_cleanup(&link_primer);
3058 		goto out_put_btp;
3059 	}
3060 
3061 	return bpf_link_settle(&link_primer);
3062 
3063 out_put_btp:
3064 	bpf_put_raw_tracepoint(btp);
3065 out_put_prog:
3066 	bpf_prog_put(prog);
3067 	return err;
3068 }
3069 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)3070 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
3071 					     enum bpf_attach_type attach_type)
3072 {
3073 	switch (prog->type) {
3074 	case BPF_PROG_TYPE_CGROUP_SOCK:
3075 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3076 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3077 	case BPF_PROG_TYPE_SK_LOOKUP:
3078 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
3079 	case BPF_PROG_TYPE_CGROUP_SKB:
3080 		if (!capable(CAP_NET_ADMIN))
3081 			/* cg-skb progs can be loaded by unpriv user.
3082 			 * check permissions at attach time.
3083 			 */
3084 			return -EPERM;
3085 		return prog->enforce_expected_attach_type &&
3086 			prog->expected_attach_type != attach_type ?
3087 			-EINVAL : 0;
3088 	default:
3089 		return 0;
3090 	}
3091 }
3092 
3093 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)3094 attach_type_to_prog_type(enum bpf_attach_type attach_type)
3095 {
3096 	switch (attach_type) {
3097 	case BPF_CGROUP_INET_INGRESS:
3098 	case BPF_CGROUP_INET_EGRESS:
3099 		return BPF_PROG_TYPE_CGROUP_SKB;
3100 	case BPF_CGROUP_INET_SOCK_CREATE:
3101 	case BPF_CGROUP_INET_SOCK_RELEASE:
3102 	case BPF_CGROUP_INET4_POST_BIND:
3103 	case BPF_CGROUP_INET6_POST_BIND:
3104 		return BPF_PROG_TYPE_CGROUP_SOCK;
3105 	case BPF_CGROUP_INET4_BIND:
3106 	case BPF_CGROUP_INET6_BIND:
3107 	case BPF_CGROUP_INET4_CONNECT:
3108 	case BPF_CGROUP_INET6_CONNECT:
3109 	case BPF_CGROUP_INET4_GETPEERNAME:
3110 	case BPF_CGROUP_INET6_GETPEERNAME:
3111 	case BPF_CGROUP_INET4_GETSOCKNAME:
3112 	case BPF_CGROUP_INET6_GETSOCKNAME:
3113 	case BPF_CGROUP_UDP4_SENDMSG:
3114 	case BPF_CGROUP_UDP6_SENDMSG:
3115 	case BPF_CGROUP_UDP4_RECVMSG:
3116 	case BPF_CGROUP_UDP6_RECVMSG:
3117 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
3118 	case BPF_CGROUP_SOCK_OPS:
3119 		return BPF_PROG_TYPE_SOCK_OPS;
3120 	case BPF_CGROUP_DEVICE:
3121 		return BPF_PROG_TYPE_CGROUP_DEVICE;
3122 	case BPF_SK_MSG_VERDICT:
3123 		return BPF_PROG_TYPE_SK_MSG;
3124 	case BPF_SK_SKB_STREAM_PARSER:
3125 	case BPF_SK_SKB_STREAM_VERDICT:
3126 	case BPF_SK_SKB_VERDICT:
3127 		return BPF_PROG_TYPE_SK_SKB;
3128 	case BPF_LIRC_MODE2:
3129 		return BPF_PROG_TYPE_LIRC_MODE2;
3130 	case BPF_FLOW_DISSECTOR:
3131 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
3132 	case BPF_CGROUP_SYSCTL:
3133 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
3134 	case BPF_CGROUP_GETSOCKOPT:
3135 	case BPF_CGROUP_SETSOCKOPT:
3136 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
3137 	case BPF_TRACE_ITER:
3138 		return BPF_PROG_TYPE_TRACING;
3139 	case BPF_SK_LOOKUP:
3140 		return BPF_PROG_TYPE_SK_LOOKUP;
3141 	case BPF_XDP:
3142 		return BPF_PROG_TYPE_XDP;
3143 	default:
3144 		return BPF_PROG_TYPE_UNSPEC;
3145 	}
3146 }
3147 
3148 #define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd
3149 
3150 #define BPF_F_ATTACH_MASK \
3151 	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)
3152 
bpf_prog_attach(const union bpf_attr * attr)3153 static int bpf_prog_attach(const union bpf_attr *attr)
3154 {
3155 	enum bpf_prog_type ptype;
3156 	struct bpf_prog *prog;
3157 	int ret;
3158 
3159 	if (CHECK_ATTR(BPF_PROG_ATTACH))
3160 		return -EINVAL;
3161 
3162 	if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
3163 		return -EINVAL;
3164 
3165 	ptype = attach_type_to_prog_type(attr->attach_type);
3166 	if (ptype == BPF_PROG_TYPE_UNSPEC)
3167 		return -EINVAL;
3168 
3169 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
3170 	if (IS_ERR(prog))
3171 		return PTR_ERR(prog);
3172 
3173 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
3174 		bpf_prog_put(prog);
3175 		return -EINVAL;
3176 	}
3177 
3178 	switch (ptype) {
3179 	case BPF_PROG_TYPE_SK_SKB:
3180 	case BPF_PROG_TYPE_SK_MSG:
3181 		ret = sock_map_get_from_fd(attr, prog);
3182 		break;
3183 	case BPF_PROG_TYPE_LIRC_MODE2:
3184 		ret = lirc_prog_attach(attr, prog);
3185 		break;
3186 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
3187 		ret = netns_bpf_prog_attach(attr, prog);
3188 		break;
3189 	case BPF_PROG_TYPE_CGROUP_DEVICE:
3190 	case BPF_PROG_TYPE_CGROUP_SKB:
3191 	case BPF_PROG_TYPE_CGROUP_SOCK:
3192 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3193 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3194 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
3195 	case BPF_PROG_TYPE_SOCK_OPS:
3196 		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
3197 		break;
3198 	default:
3199 		ret = -EINVAL;
3200 	}
3201 
3202 	if (ret)
3203 		bpf_prog_put(prog);
3204 	return ret;
3205 }
3206 
3207 #define BPF_PROG_DETACH_LAST_FIELD attach_type
3208 
bpf_prog_detach(const union bpf_attr * attr)3209 static int bpf_prog_detach(const union bpf_attr *attr)
3210 {
3211 	enum bpf_prog_type ptype;
3212 
3213 	if (CHECK_ATTR(BPF_PROG_DETACH))
3214 		return -EINVAL;
3215 
3216 	ptype = attach_type_to_prog_type(attr->attach_type);
3217 
3218 	switch (ptype) {
3219 	case BPF_PROG_TYPE_SK_MSG:
3220 	case BPF_PROG_TYPE_SK_SKB:
3221 		return sock_map_prog_detach(attr, ptype);
3222 	case BPF_PROG_TYPE_LIRC_MODE2:
3223 		return lirc_prog_detach(attr);
3224 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
3225 		return netns_bpf_prog_detach(attr, ptype);
3226 	case BPF_PROG_TYPE_CGROUP_DEVICE:
3227 	case BPF_PROG_TYPE_CGROUP_SKB:
3228 	case BPF_PROG_TYPE_CGROUP_SOCK:
3229 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3230 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3231 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
3232 	case BPF_PROG_TYPE_SOCK_OPS:
3233 		return cgroup_bpf_prog_detach(attr, ptype);
3234 	default:
3235 		return -EINVAL;
3236 	}
3237 }
3238 
3239 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
3240 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)3241 static int bpf_prog_query(const union bpf_attr *attr,
3242 			  union bpf_attr __user *uattr)
3243 {
3244 	if (!capable(CAP_NET_ADMIN))
3245 		return -EPERM;
3246 	if (CHECK_ATTR(BPF_PROG_QUERY))
3247 		return -EINVAL;
3248 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
3249 		return -EINVAL;
3250 
3251 	switch (attr->query.attach_type) {
3252 	case BPF_CGROUP_INET_INGRESS:
3253 	case BPF_CGROUP_INET_EGRESS:
3254 	case BPF_CGROUP_INET_SOCK_CREATE:
3255 	case BPF_CGROUP_INET_SOCK_RELEASE:
3256 	case BPF_CGROUP_INET4_BIND:
3257 	case BPF_CGROUP_INET6_BIND:
3258 	case BPF_CGROUP_INET4_POST_BIND:
3259 	case BPF_CGROUP_INET6_POST_BIND:
3260 	case BPF_CGROUP_INET4_CONNECT:
3261 	case BPF_CGROUP_INET6_CONNECT:
3262 	case BPF_CGROUP_INET4_GETPEERNAME:
3263 	case BPF_CGROUP_INET6_GETPEERNAME:
3264 	case BPF_CGROUP_INET4_GETSOCKNAME:
3265 	case BPF_CGROUP_INET6_GETSOCKNAME:
3266 	case BPF_CGROUP_UDP4_SENDMSG:
3267 	case BPF_CGROUP_UDP6_SENDMSG:
3268 	case BPF_CGROUP_UDP4_RECVMSG:
3269 	case BPF_CGROUP_UDP6_RECVMSG:
3270 	case BPF_CGROUP_SOCK_OPS:
3271 	case BPF_CGROUP_DEVICE:
3272 	case BPF_CGROUP_SYSCTL:
3273 	case BPF_CGROUP_GETSOCKOPT:
3274 	case BPF_CGROUP_SETSOCKOPT:
3275 		return cgroup_bpf_prog_query(attr, uattr);
3276 	case BPF_LIRC_MODE2:
3277 		return lirc_prog_query(attr, uattr);
3278 	case BPF_FLOW_DISSECTOR:
3279 	case BPF_SK_LOOKUP:
3280 		return netns_bpf_prog_query(attr, uattr);
3281 	default:
3282 		return -EINVAL;
3283 	}
3284 }
3285 
3286 #define BPF_PROG_TEST_RUN_LAST_FIELD test.cpu
3287 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)3288 static int bpf_prog_test_run(const union bpf_attr *attr,
3289 			     union bpf_attr __user *uattr)
3290 {
3291 	struct bpf_prog *prog;
3292 	int ret = -ENOTSUPP;
3293 
3294 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
3295 		return -EINVAL;
3296 
3297 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
3298 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
3299 		return -EINVAL;
3300 
3301 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
3302 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
3303 		return -EINVAL;
3304 
3305 	prog = bpf_prog_get(attr->test.prog_fd);
3306 	if (IS_ERR(prog))
3307 		return PTR_ERR(prog);
3308 
3309 	if (prog->aux->ops->test_run)
3310 		ret = prog->aux->ops->test_run(prog, attr, uattr);
3311 
3312 	bpf_prog_put(prog);
3313 	return ret;
3314 }
3315 
3316 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
3317 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)3318 static int bpf_obj_get_next_id(const union bpf_attr *attr,
3319 			       union bpf_attr __user *uattr,
3320 			       struct idr *idr,
3321 			       spinlock_t *lock)
3322 {
3323 	u32 next_id = attr->start_id;
3324 	int err = 0;
3325 
3326 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
3327 		return -EINVAL;
3328 
3329 	if (!capable(CAP_SYS_ADMIN))
3330 		return -EPERM;
3331 
3332 	next_id++;
3333 	spin_lock_bh(lock);
3334 	if (!idr_get_next(idr, &next_id))
3335 		err = -ENOENT;
3336 	spin_unlock_bh(lock);
3337 
3338 	if (!err)
3339 		err = put_user(next_id, &uattr->next_id);
3340 
3341 	return err;
3342 }
3343 
bpf_map_get_curr_or_next(u32 * id)3344 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
3345 {
3346 	struct bpf_map *map;
3347 
3348 	spin_lock_bh(&map_idr_lock);
3349 again:
3350 	map = idr_get_next(&map_idr, id);
3351 	if (map) {
3352 		map = __bpf_map_inc_not_zero(map, false);
3353 		if (IS_ERR(map)) {
3354 			(*id)++;
3355 			goto again;
3356 		}
3357 	}
3358 	spin_unlock_bh(&map_idr_lock);
3359 
3360 	return map;
3361 }
3362 
bpf_prog_get_curr_or_next(u32 * id)3363 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
3364 {
3365 	struct bpf_prog *prog;
3366 
3367 	spin_lock_bh(&prog_idr_lock);
3368 again:
3369 	prog = idr_get_next(&prog_idr, id);
3370 	if (prog) {
3371 		prog = bpf_prog_inc_not_zero(prog);
3372 		if (IS_ERR(prog)) {
3373 			(*id)++;
3374 			goto again;
3375 		}
3376 	}
3377 	spin_unlock_bh(&prog_idr_lock);
3378 
3379 	return prog;
3380 }
3381 
3382 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
3383 
bpf_prog_by_id(u32 id)3384 struct bpf_prog *bpf_prog_by_id(u32 id)
3385 {
3386 	struct bpf_prog *prog;
3387 
3388 	if (!id)
3389 		return ERR_PTR(-ENOENT);
3390 
3391 	spin_lock_bh(&prog_idr_lock);
3392 	prog = idr_find(&prog_idr, id);
3393 	if (prog)
3394 		prog = bpf_prog_inc_not_zero(prog);
3395 	else
3396 		prog = ERR_PTR(-ENOENT);
3397 	spin_unlock_bh(&prog_idr_lock);
3398 	return prog;
3399 }
3400 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)3401 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
3402 {
3403 	struct bpf_prog *prog;
3404 	u32 id = attr->prog_id;
3405 	int fd;
3406 
3407 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
3408 		return -EINVAL;
3409 
3410 	if (!capable(CAP_SYS_ADMIN))
3411 		return -EPERM;
3412 
3413 	prog = bpf_prog_by_id(id);
3414 	if (IS_ERR(prog))
3415 		return PTR_ERR(prog);
3416 
3417 	fd = bpf_prog_new_fd(prog);
3418 	if (fd < 0)
3419 		bpf_prog_put(prog);
3420 
3421 	return fd;
3422 }
3423 
3424 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
3425 
bpf_map_get_fd_by_id(const union bpf_attr * attr)3426 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
3427 {
3428 	struct bpf_map *map;
3429 	u32 id = attr->map_id;
3430 	int f_flags;
3431 	int fd;
3432 
3433 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
3434 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
3435 		return -EINVAL;
3436 
3437 	if (!capable(CAP_SYS_ADMIN))
3438 		return -EPERM;
3439 
3440 	f_flags = bpf_get_file_flag(attr->open_flags);
3441 	if (f_flags < 0)
3442 		return f_flags;
3443 
3444 	spin_lock_bh(&map_idr_lock);
3445 	map = idr_find(&map_idr, id);
3446 	if (map)
3447 		map = __bpf_map_inc_not_zero(map, true);
3448 	else
3449 		map = ERR_PTR(-ENOENT);
3450 	spin_unlock_bh(&map_idr_lock);
3451 
3452 	if (IS_ERR(map))
3453 		return PTR_ERR(map);
3454 
3455 	fd = bpf_map_new_fd(map, f_flags);
3456 	if (fd < 0)
3457 		bpf_map_put_with_uref(map);
3458 
3459 	return fd;
3460 }
3461 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)3462 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
3463 					      unsigned long addr, u32 *off,
3464 					      u32 *type)
3465 {
3466 	const struct bpf_map *map;
3467 	int i;
3468 
3469 	mutex_lock(&prog->aux->used_maps_mutex);
3470 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
3471 		map = prog->aux->used_maps[i];
3472 		if (map == (void *)addr) {
3473 			*type = BPF_PSEUDO_MAP_FD;
3474 			goto out;
3475 		}
3476 		if (!map->ops->map_direct_value_meta)
3477 			continue;
3478 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
3479 			*type = BPF_PSEUDO_MAP_VALUE;
3480 			goto out;
3481 		}
3482 	}
3483 	map = NULL;
3484 
3485 out:
3486 	mutex_unlock(&prog->aux->used_maps_mutex);
3487 	return map;
3488 }
3489 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)3490 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
3491 					      const struct cred *f_cred)
3492 {
3493 	const struct bpf_map *map;
3494 	struct bpf_insn *insns;
3495 	u32 off, type;
3496 	u64 imm;
3497 	u8 code;
3498 	int i;
3499 
3500 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
3501 			GFP_USER);
3502 	if (!insns)
3503 		return insns;
3504 
3505 	for (i = 0; i < prog->len; i++) {
3506 		code = insns[i].code;
3507 
3508 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
3509 			insns[i].code = BPF_JMP | BPF_CALL;
3510 			insns[i].imm = BPF_FUNC_tail_call;
3511 			/* fall-through */
3512 		}
3513 		if (code == (BPF_JMP | BPF_CALL) ||
3514 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
3515 			if (code == (BPF_JMP | BPF_CALL_ARGS))
3516 				insns[i].code = BPF_JMP | BPF_CALL;
3517 			if (!bpf_dump_raw_ok(f_cred))
3518 				insns[i].imm = 0;
3519 			continue;
3520 		}
3521 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
3522 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
3523 			continue;
3524 		}
3525 
3526 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
3527 			continue;
3528 
3529 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
3530 		map = bpf_map_from_imm(prog, imm, &off, &type);
3531 		if (map) {
3532 			insns[i].src_reg = type;
3533 			insns[i].imm = map->id;
3534 			insns[i + 1].imm = off;
3535 			continue;
3536 		}
3537 	}
3538 
3539 	return insns;
3540 }
3541 
set_info_rec_size(struct bpf_prog_info * info)3542 static int set_info_rec_size(struct bpf_prog_info *info)
3543 {
3544 	/*
3545 	 * Ensure info.*_rec_size is the same as kernel expected size
3546 	 *
3547 	 * or
3548 	 *
3549 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
3550 	 * zero.  In this case, the kernel will set the expected
3551 	 * _rec_size back to the info.
3552 	 */
3553 
3554 	if ((info->nr_func_info || info->func_info_rec_size) &&
3555 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
3556 		return -EINVAL;
3557 
3558 	if ((info->nr_line_info || info->line_info_rec_size) &&
3559 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
3560 		return -EINVAL;
3561 
3562 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
3563 	    info->jited_line_info_rec_size != sizeof(__u64))
3564 		return -EINVAL;
3565 
3566 	info->func_info_rec_size = sizeof(struct bpf_func_info);
3567 	info->line_info_rec_size = sizeof(struct bpf_line_info);
3568 	info->jited_line_info_rec_size = sizeof(__u64);
3569 
3570 	return 0;
3571 }
3572 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)3573 static int bpf_prog_get_info_by_fd(struct file *file,
3574 				   struct bpf_prog *prog,
3575 				   const union bpf_attr *attr,
3576 				   union bpf_attr __user *uattr)
3577 {
3578 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3579 	struct bpf_prog_info info;
3580 	u32 info_len = attr->info.info_len;
3581 	struct bpf_prog_stats stats;
3582 	char __user *uinsns;
3583 	u32 ulen;
3584 	int err;
3585 
3586 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3587 	if (err)
3588 		return err;
3589 	info_len = min_t(u32, sizeof(info), info_len);
3590 
3591 	memset(&info, 0, sizeof(info));
3592 	if (copy_from_user(&info, uinfo, info_len))
3593 		return -EFAULT;
3594 
3595 	info.type = prog->type;
3596 	info.id = prog->aux->id;
3597 	info.load_time = prog->aux->load_time;
3598 	info.created_by_uid = from_kuid_munged(current_user_ns(),
3599 					       prog->aux->user->uid);
3600 	info.gpl_compatible = prog->gpl_compatible;
3601 
3602 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
3603 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
3604 
3605 	mutex_lock(&prog->aux->used_maps_mutex);
3606 	ulen = info.nr_map_ids;
3607 	info.nr_map_ids = prog->aux->used_map_cnt;
3608 	ulen = min_t(u32, info.nr_map_ids, ulen);
3609 	if (ulen) {
3610 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
3611 		u32 i;
3612 
3613 		for (i = 0; i < ulen; i++)
3614 			if (put_user(prog->aux->used_maps[i]->id,
3615 				     &user_map_ids[i])) {
3616 				mutex_unlock(&prog->aux->used_maps_mutex);
3617 				return -EFAULT;
3618 			}
3619 	}
3620 	mutex_unlock(&prog->aux->used_maps_mutex);
3621 
3622 	err = set_info_rec_size(&info);
3623 	if (err)
3624 		return err;
3625 
3626 	bpf_prog_get_stats(prog, &stats);
3627 	info.run_time_ns = stats.nsecs;
3628 	info.run_cnt = stats.cnt;
3629 	info.recursion_misses = stats.misses;
3630 
3631 	if (!bpf_capable()) {
3632 		info.jited_prog_len = 0;
3633 		info.xlated_prog_len = 0;
3634 		info.nr_jited_ksyms = 0;
3635 		info.nr_jited_func_lens = 0;
3636 		info.nr_func_info = 0;
3637 		info.nr_line_info = 0;
3638 		info.nr_jited_line_info = 0;
3639 		goto done;
3640 	}
3641 
3642 	ulen = info.xlated_prog_len;
3643 	info.xlated_prog_len = bpf_prog_insn_size(prog);
3644 	if (info.xlated_prog_len && ulen) {
3645 		struct bpf_insn *insns_sanitized;
3646 		bool fault;
3647 
3648 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
3649 			info.xlated_prog_insns = 0;
3650 			goto done;
3651 		}
3652 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
3653 		if (!insns_sanitized)
3654 			return -ENOMEM;
3655 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
3656 		ulen = min_t(u32, info.xlated_prog_len, ulen);
3657 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
3658 		kfree(insns_sanitized);
3659 		if (fault)
3660 			return -EFAULT;
3661 	}
3662 
3663 	if (bpf_prog_is_dev_bound(prog->aux)) {
3664 		err = bpf_prog_offload_info_fill(&info, prog);
3665 		if (err)
3666 			return err;
3667 		goto done;
3668 	}
3669 
3670 	/* NOTE: the following code is supposed to be skipped for offload.
3671 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
3672 	 * for offload.
3673 	 */
3674 	ulen = info.jited_prog_len;
3675 	if (prog->aux->func_cnt) {
3676 		u32 i;
3677 
3678 		info.jited_prog_len = 0;
3679 		for (i = 0; i < prog->aux->func_cnt; i++)
3680 			info.jited_prog_len += prog->aux->func[i]->jited_len;
3681 	} else {
3682 		info.jited_prog_len = prog->jited_len;
3683 	}
3684 
3685 	if (info.jited_prog_len && ulen) {
3686 		if (bpf_dump_raw_ok(file->f_cred)) {
3687 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
3688 			ulen = min_t(u32, info.jited_prog_len, ulen);
3689 
3690 			/* for multi-function programs, copy the JITed
3691 			 * instructions for all the functions
3692 			 */
3693 			if (prog->aux->func_cnt) {
3694 				u32 len, free, i;
3695 				u8 *img;
3696 
3697 				free = ulen;
3698 				for (i = 0; i < prog->aux->func_cnt; i++) {
3699 					len = prog->aux->func[i]->jited_len;
3700 					len = min_t(u32, len, free);
3701 					img = (u8 *) prog->aux->func[i]->bpf_func;
3702 					if (copy_to_user(uinsns, img, len))
3703 						return -EFAULT;
3704 					uinsns += len;
3705 					free -= len;
3706 					if (!free)
3707 						break;
3708 				}
3709 			} else {
3710 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
3711 					return -EFAULT;
3712 			}
3713 		} else {
3714 			info.jited_prog_insns = 0;
3715 		}
3716 	}
3717 
3718 	ulen = info.nr_jited_ksyms;
3719 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
3720 	if (ulen) {
3721 		if (bpf_dump_raw_ok(file->f_cred)) {
3722 			unsigned long ksym_addr;
3723 			u64 __user *user_ksyms;
3724 			u32 i;
3725 
3726 			/* copy the address of the kernel symbol
3727 			 * corresponding to each function
3728 			 */
3729 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
3730 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
3731 			if (prog->aux->func_cnt) {
3732 				for (i = 0; i < ulen; i++) {
3733 					ksym_addr = (unsigned long)
3734 						prog->aux->func[i]->bpf_func;
3735 					if (put_user((u64) ksym_addr,
3736 						     &user_ksyms[i]))
3737 						return -EFAULT;
3738 				}
3739 			} else {
3740 				ksym_addr = (unsigned long) prog->bpf_func;
3741 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
3742 					return -EFAULT;
3743 			}
3744 		} else {
3745 			info.jited_ksyms = 0;
3746 		}
3747 	}
3748 
3749 	ulen = info.nr_jited_func_lens;
3750 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
3751 	if (ulen) {
3752 		if (bpf_dump_raw_ok(file->f_cred)) {
3753 			u32 __user *user_lens;
3754 			u32 func_len, i;
3755 
3756 			/* copy the JITed image lengths for each function */
3757 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
3758 			user_lens = u64_to_user_ptr(info.jited_func_lens);
3759 			if (prog->aux->func_cnt) {
3760 				for (i = 0; i < ulen; i++) {
3761 					func_len =
3762 						prog->aux->func[i]->jited_len;
3763 					if (put_user(func_len, &user_lens[i]))
3764 						return -EFAULT;
3765 				}
3766 			} else {
3767 				func_len = prog->jited_len;
3768 				if (put_user(func_len, &user_lens[0]))
3769 					return -EFAULT;
3770 			}
3771 		} else {
3772 			info.jited_func_lens = 0;
3773 		}
3774 	}
3775 
3776 	if (prog->aux->btf)
3777 		info.btf_id = btf_obj_id(prog->aux->btf);
3778 
3779 	ulen = info.nr_func_info;
3780 	info.nr_func_info = prog->aux->func_info_cnt;
3781 	if (info.nr_func_info && ulen) {
3782 		char __user *user_finfo;
3783 
3784 		user_finfo = u64_to_user_ptr(info.func_info);
3785 		ulen = min_t(u32, info.nr_func_info, ulen);
3786 		if (copy_to_user(user_finfo, prog->aux->func_info,
3787 				 info.func_info_rec_size * ulen))
3788 			return -EFAULT;
3789 	}
3790 
3791 	ulen = info.nr_line_info;
3792 	info.nr_line_info = prog->aux->nr_linfo;
3793 	if (info.nr_line_info && ulen) {
3794 		__u8 __user *user_linfo;
3795 
3796 		user_linfo = u64_to_user_ptr(info.line_info);
3797 		ulen = min_t(u32, info.nr_line_info, ulen);
3798 		if (copy_to_user(user_linfo, prog->aux->linfo,
3799 				 info.line_info_rec_size * ulen))
3800 			return -EFAULT;
3801 	}
3802 
3803 	ulen = info.nr_jited_line_info;
3804 	if (prog->aux->jited_linfo)
3805 		info.nr_jited_line_info = prog->aux->nr_linfo;
3806 	else
3807 		info.nr_jited_line_info = 0;
3808 	if (info.nr_jited_line_info && ulen) {
3809 		if (bpf_dump_raw_ok(file->f_cred)) {
3810 			__u64 __user *user_linfo;
3811 			u32 i;
3812 
3813 			user_linfo = u64_to_user_ptr(info.jited_line_info);
3814 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
3815 			for (i = 0; i < ulen; i++) {
3816 				if (put_user((__u64)(long)prog->aux->jited_linfo[i],
3817 					     &user_linfo[i]))
3818 					return -EFAULT;
3819 			}
3820 		} else {
3821 			info.jited_line_info = 0;
3822 		}
3823 	}
3824 
3825 	ulen = info.nr_prog_tags;
3826 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
3827 	if (ulen) {
3828 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
3829 		u32 i;
3830 
3831 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
3832 		ulen = min_t(u32, info.nr_prog_tags, ulen);
3833 		if (prog->aux->func_cnt) {
3834 			for (i = 0; i < ulen; i++) {
3835 				if (copy_to_user(user_prog_tags[i],
3836 						 prog->aux->func[i]->tag,
3837 						 BPF_TAG_SIZE))
3838 					return -EFAULT;
3839 			}
3840 		} else {
3841 			if (copy_to_user(user_prog_tags[0],
3842 					 prog->tag, BPF_TAG_SIZE))
3843 				return -EFAULT;
3844 		}
3845 	}
3846 
3847 done:
3848 	if (copy_to_user(uinfo, &info, info_len) ||
3849 	    put_user(info_len, &uattr->info.info_len))
3850 		return -EFAULT;
3851 
3852 	return 0;
3853 }
3854 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)3855 static int bpf_map_get_info_by_fd(struct file *file,
3856 				  struct bpf_map *map,
3857 				  const union bpf_attr *attr,
3858 				  union bpf_attr __user *uattr)
3859 {
3860 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3861 	struct bpf_map_info info;
3862 	u32 info_len = attr->info.info_len;
3863 	int err;
3864 
3865 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3866 	if (err)
3867 		return err;
3868 	info_len = min_t(u32, sizeof(info), info_len);
3869 
3870 	memset(&info, 0, sizeof(info));
3871 	info.type = map->map_type;
3872 	info.id = map->id;
3873 	info.key_size = map->key_size;
3874 	info.value_size = map->value_size;
3875 	info.max_entries = map->max_entries;
3876 	info.map_flags = map->map_flags;
3877 	memcpy(info.name, map->name, sizeof(map->name));
3878 
3879 	if (map->btf) {
3880 		info.btf_id = btf_obj_id(map->btf);
3881 		info.btf_key_type_id = map->btf_key_type_id;
3882 		info.btf_value_type_id = map->btf_value_type_id;
3883 	}
3884 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
3885 
3886 	if (bpf_map_is_dev_bound(map)) {
3887 		err = bpf_map_offload_info_fill(&info, map);
3888 		if (err)
3889 			return err;
3890 	}
3891 
3892 	if (copy_to_user(uinfo, &info, info_len) ||
3893 	    put_user(info_len, &uattr->info.info_len))
3894 		return -EFAULT;
3895 
3896 	return 0;
3897 }
3898 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)3899 static int bpf_btf_get_info_by_fd(struct file *file,
3900 				  struct btf *btf,
3901 				  const union bpf_attr *attr,
3902 				  union bpf_attr __user *uattr)
3903 {
3904 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3905 	u32 info_len = attr->info.info_len;
3906 	int err;
3907 
3908 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
3909 	if (err)
3910 		return err;
3911 
3912 	return btf_get_info_by_fd(btf, attr, uattr);
3913 }
3914 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)3915 static int bpf_link_get_info_by_fd(struct file *file,
3916 				  struct bpf_link *link,
3917 				  const union bpf_attr *attr,
3918 				  union bpf_attr __user *uattr)
3919 {
3920 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3921 	struct bpf_link_info info;
3922 	u32 info_len = attr->info.info_len;
3923 	int err;
3924 
3925 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3926 	if (err)
3927 		return err;
3928 	info_len = min_t(u32, sizeof(info), info_len);
3929 
3930 	memset(&info, 0, sizeof(info));
3931 	if (copy_from_user(&info, uinfo, info_len))
3932 		return -EFAULT;
3933 
3934 	info.type = link->type;
3935 	info.id = link->id;
3936 	info.prog_id = link->prog->aux->id;
3937 
3938 	if (link->ops->fill_link_info) {
3939 		err = link->ops->fill_link_info(link, &info);
3940 		if (err)
3941 			return err;
3942 	}
3943 
3944 	if (copy_to_user(uinfo, &info, info_len) ||
3945 	    put_user(info_len, &uattr->info.info_len))
3946 		return -EFAULT;
3947 
3948 	return 0;
3949 }
3950 
3951 
3952 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
3953 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)3954 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
3955 				  union bpf_attr __user *uattr)
3956 {
3957 	int ufd = attr->info.bpf_fd;
3958 	struct fd f;
3959 	int err;
3960 
3961 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
3962 		return -EINVAL;
3963 
3964 	f = fdget(ufd);
3965 	if (!f.file)
3966 		return -EBADFD;
3967 
3968 	if (f.file->f_op == &bpf_prog_fops)
3969 		err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
3970 					      uattr);
3971 	else if (f.file->f_op == &bpf_map_fops)
3972 		err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
3973 					     uattr);
3974 	else if (f.file->f_op == &btf_fops)
3975 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
3976 	else if (f.file->f_op == &bpf_link_fops)
3977 		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
3978 					      attr, uattr);
3979 	else
3980 		err = -EINVAL;
3981 
3982 	fdput(f);
3983 	return err;
3984 }
3985 
3986 #define BPF_BTF_LOAD_LAST_FIELD btf_log_level
3987 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr)3988 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr)
3989 {
3990 	if (CHECK_ATTR(BPF_BTF_LOAD))
3991 		return -EINVAL;
3992 
3993 	if (!bpf_capable())
3994 		return -EPERM;
3995 
3996 	return btf_new_fd(attr, uattr);
3997 }
3998 
3999 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
4000 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)4001 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
4002 {
4003 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
4004 		return -EINVAL;
4005 
4006 	if (!capable(CAP_SYS_ADMIN))
4007 		return -EPERM;
4008 
4009 	return btf_get_fd_by_id(attr->btf_id);
4010 }
4011 
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)4012 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
4013 				    union bpf_attr __user *uattr,
4014 				    u32 prog_id, u32 fd_type,
4015 				    const char *buf, u64 probe_offset,
4016 				    u64 probe_addr)
4017 {
4018 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
4019 	u32 len = buf ? strlen(buf) : 0, input_len;
4020 	int err = 0;
4021 
4022 	if (put_user(len, &uattr->task_fd_query.buf_len))
4023 		return -EFAULT;
4024 	input_len = attr->task_fd_query.buf_len;
4025 	if (input_len && ubuf) {
4026 		if (!len) {
4027 			/* nothing to copy, just make ubuf NULL terminated */
4028 			char zero = '\0';
4029 
4030 			if (put_user(zero, ubuf))
4031 				return -EFAULT;
4032 		} else if (input_len >= len + 1) {
4033 			/* ubuf can hold the string with NULL terminator */
4034 			if (copy_to_user(ubuf, buf, len + 1))
4035 				return -EFAULT;
4036 		} else {
4037 			/* ubuf cannot hold the string with NULL terminator,
4038 			 * do a partial copy with NULL terminator.
4039 			 */
4040 			char zero = '\0';
4041 
4042 			err = -ENOSPC;
4043 			if (copy_to_user(ubuf, buf, input_len - 1))
4044 				return -EFAULT;
4045 			if (put_user(zero, ubuf + input_len - 1))
4046 				return -EFAULT;
4047 		}
4048 	}
4049 
4050 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
4051 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
4052 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
4053 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
4054 		return -EFAULT;
4055 
4056 	return err;
4057 }
4058 
4059 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
4060 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4061 static int bpf_task_fd_query(const union bpf_attr *attr,
4062 			     union bpf_attr __user *uattr)
4063 {
4064 	pid_t pid = attr->task_fd_query.pid;
4065 	u32 fd = attr->task_fd_query.fd;
4066 	const struct perf_event *event;
4067 	struct task_struct *task;
4068 	struct file *file;
4069 	int err;
4070 
4071 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
4072 		return -EINVAL;
4073 
4074 	if (!capable(CAP_SYS_ADMIN))
4075 		return -EPERM;
4076 
4077 	if (attr->task_fd_query.flags != 0)
4078 		return -EINVAL;
4079 
4080 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
4081 	if (!task)
4082 		return -ENOENT;
4083 
4084 	err = 0;
4085 	file = fget_task(task, fd);
4086 	put_task_struct(task);
4087 	if (!file)
4088 		return -EBADF;
4089 
4090 	if (file->f_op == &bpf_link_fops) {
4091 		struct bpf_link *link = file->private_data;
4092 
4093 		if (link->ops == &bpf_raw_tp_link_lops) {
4094 			struct bpf_raw_tp_link *raw_tp =
4095 				container_of(link, struct bpf_raw_tp_link, link);
4096 			struct bpf_raw_event_map *btp = raw_tp->btp;
4097 
4098 			err = bpf_task_fd_query_copy(attr, uattr,
4099 						     raw_tp->link.prog->aux->id,
4100 						     BPF_FD_TYPE_RAW_TRACEPOINT,
4101 						     btp->tp->name, 0, 0);
4102 			goto put_file;
4103 		}
4104 		goto out_not_supp;
4105 	}
4106 
4107 	event = perf_get_event(file);
4108 	if (!IS_ERR(event)) {
4109 		u64 probe_offset, probe_addr;
4110 		u32 prog_id, fd_type;
4111 		const char *buf;
4112 
4113 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
4114 					      &buf, &probe_offset,
4115 					      &probe_addr);
4116 		if (!err)
4117 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
4118 						     fd_type, buf,
4119 						     probe_offset,
4120 						     probe_addr);
4121 		goto put_file;
4122 	}
4123 
4124 out_not_supp:
4125 	err = -ENOTSUPP;
4126 put_file:
4127 	fput(file);
4128 	return err;
4129 }
4130 
4131 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
4132 
4133 #define BPF_DO_BATCH(fn)			\
4134 	do {					\
4135 		if (!fn) {			\
4136 			err = -ENOTSUPP;	\
4137 			goto err_put;		\
4138 		}				\
4139 		err = fn(map, attr, uattr);	\
4140 	} while (0)
4141 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)4142 static int bpf_map_do_batch(const union bpf_attr *attr,
4143 			    union bpf_attr __user *uattr,
4144 			    int cmd)
4145 {
4146 	struct bpf_map *map;
4147 	int err, ufd;
4148 	struct fd f;
4149 
4150 	if (CHECK_ATTR(BPF_MAP_BATCH))
4151 		return -EINVAL;
4152 
4153 	ufd = attr->batch.map_fd;
4154 	f = fdget(ufd);
4155 	map = __bpf_map_get(f);
4156 	if (IS_ERR(map))
4157 		return PTR_ERR(map);
4158 
4159 	if ((cmd == BPF_MAP_LOOKUP_BATCH ||
4160 	     cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH) &&
4161 	    !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
4162 		err = -EPERM;
4163 		goto err_put;
4164 	}
4165 
4166 	if (cmd != BPF_MAP_LOOKUP_BATCH &&
4167 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
4168 		err = -EPERM;
4169 		goto err_put;
4170 	}
4171 
4172 	if (cmd == BPF_MAP_LOOKUP_BATCH)
4173 		BPF_DO_BATCH(map->ops->map_lookup_batch);
4174 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
4175 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch);
4176 	else if (cmd == BPF_MAP_UPDATE_BATCH)
4177 		BPF_DO_BATCH(map->ops->map_update_batch);
4178 	else
4179 		BPF_DO_BATCH(map->ops->map_delete_batch);
4180 
4181 err_put:
4182 	fdput(f);
4183 	return err;
4184 }
4185 
tracing_bpf_link_attach(const union bpf_attr * attr,bpfptr_t uattr,struct bpf_prog * prog)4186 static int tracing_bpf_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
4187 				   struct bpf_prog *prog)
4188 {
4189 	if (attr->link_create.attach_type != prog->expected_attach_type)
4190 		return -EINVAL;
4191 
4192 	if (prog->expected_attach_type == BPF_TRACE_ITER)
4193 		return bpf_iter_link_attach(attr, uattr, prog);
4194 	else if (prog->type == BPF_PROG_TYPE_EXT)
4195 		return bpf_tracing_prog_attach(prog,
4196 					       attr->link_create.target_fd,
4197 					       attr->link_create.target_btf_id);
4198 	return -EINVAL;
4199 }
4200 
4201 #define BPF_LINK_CREATE_LAST_FIELD link_create.iter_info_len
link_create(union bpf_attr * attr,bpfptr_t uattr)4202 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
4203 {
4204 	enum bpf_prog_type ptype;
4205 	struct bpf_prog *prog;
4206 	int ret;
4207 
4208 	if (CHECK_ATTR(BPF_LINK_CREATE))
4209 		return -EINVAL;
4210 
4211 	prog = bpf_prog_get(attr->link_create.prog_fd);
4212 	if (IS_ERR(prog))
4213 		return PTR_ERR(prog);
4214 
4215 	ret = bpf_prog_attach_check_attach_type(prog,
4216 						attr->link_create.attach_type);
4217 	if (ret)
4218 		goto out;
4219 
4220 	switch (prog->type) {
4221 	case BPF_PROG_TYPE_EXT:
4222 		ret = tracing_bpf_link_attach(attr, uattr, prog);
4223 		goto out;
4224 	case BPF_PROG_TYPE_PERF_EVENT:
4225 	case BPF_PROG_TYPE_KPROBE:
4226 	case BPF_PROG_TYPE_TRACEPOINT:
4227 		if (attr->link_create.attach_type != BPF_PERF_EVENT) {
4228 			ret = -EINVAL;
4229 			goto out;
4230 		}
4231 		ptype = prog->type;
4232 		break;
4233 	default:
4234 		ptype = attach_type_to_prog_type(attr->link_create.attach_type);
4235 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) {
4236 			ret = -EINVAL;
4237 			goto out;
4238 		}
4239 		break;
4240 	}
4241 
4242 	switch (ptype) {
4243 	case BPF_PROG_TYPE_CGROUP_SKB:
4244 	case BPF_PROG_TYPE_CGROUP_SOCK:
4245 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4246 	case BPF_PROG_TYPE_SOCK_OPS:
4247 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4248 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4249 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4250 		ret = cgroup_bpf_link_attach(attr, prog);
4251 		break;
4252 	case BPF_PROG_TYPE_TRACING:
4253 		ret = tracing_bpf_link_attach(attr, uattr, prog);
4254 		break;
4255 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4256 	case BPF_PROG_TYPE_SK_LOOKUP:
4257 		ret = netns_bpf_link_create(attr, prog);
4258 		break;
4259 #ifdef CONFIG_NET
4260 	case BPF_PROG_TYPE_XDP:
4261 		ret = bpf_xdp_link_attach(attr, prog);
4262 		break;
4263 #endif
4264 #ifdef CONFIG_PERF_EVENTS
4265 	case BPF_PROG_TYPE_PERF_EVENT:
4266 	case BPF_PROG_TYPE_TRACEPOINT:
4267 	case BPF_PROG_TYPE_KPROBE:
4268 		ret = bpf_perf_link_attach(attr, prog);
4269 		break;
4270 #endif
4271 	default:
4272 		ret = -EINVAL;
4273 	}
4274 
4275 out:
4276 	if (ret < 0)
4277 		bpf_prog_put(prog);
4278 	return ret;
4279 }
4280 
4281 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
4282 
link_update(union bpf_attr * attr)4283 static int link_update(union bpf_attr *attr)
4284 {
4285 	struct bpf_prog *old_prog = NULL, *new_prog;
4286 	struct bpf_link *link;
4287 	u32 flags;
4288 	int ret;
4289 
4290 	if (CHECK_ATTR(BPF_LINK_UPDATE))
4291 		return -EINVAL;
4292 
4293 	flags = attr->link_update.flags;
4294 	if (flags & ~BPF_F_REPLACE)
4295 		return -EINVAL;
4296 
4297 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
4298 	if (IS_ERR(link))
4299 		return PTR_ERR(link);
4300 
4301 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
4302 	if (IS_ERR(new_prog)) {
4303 		ret = PTR_ERR(new_prog);
4304 		goto out_put_link;
4305 	}
4306 
4307 	if (flags & BPF_F_REPLACE) {
4308 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
4309 		if (IS_ERR(old_prog)) {
4310 			ret = PTR_ERR(old_prog);
4311 			old_prog = NULL;
4312 			goto out_put_progs;
4313 		}
4314 	} else if (attr->link_update.old_prog_fd) {
4315 		ret = -EINVAL;
4316 		goto out_put_progs;
4317 	}
4318 
4319 	if (link->ops->update_prog)
4320 		ret = link->ops->update_prog(link, new_prog, old_prog);
4321 	else
4322 		ret = -EINVAL;
4323 
4324 out_put_progs:
4325 	if (old_prog)
4326 		bpf_prog_put(old_prog);
4327 	if (ret)
4328 		bpf_prog_put(new_prog);
4329 out_put_link:
4330 	bpf_link_put(link);
4331 	return ret;
4332 }
4333 
4334 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
4335 
link_detach(union bpf_attr * attr)4336 static int link_detach(union bpf_attr *attr)
4337 {
4338 	struct bpf_link *link;
4339 	int ret;
4340 
4341 	if (CHECK_ATTR(BPF_LINK_DETACH))
4342 		return -EINVAL;
4343 
4344 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
4345 	if (IS_ERR(link))
4346 		return PTR_ERR(link);
4347 
4348 	if (link->ops->detach)
4349 		ret = link->ops->detach(link);
4350 	else
4351 		ret = -EOPNOTSUPP;
4352 
4353 	bpf_link_put(link);
4354 	return ret;
4355 }
4356 
bpf_link_inc_not_zero(struct bpf_link * link)4357 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
4358 {
4359 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
4360 }
4361 
bpf_link_by_id(u32 id)4362 struct bpf_link *bpf_link_by_id(u32 id)
4363 {
4364 	struct bpf_link *link;
4365 
4366 	if (!id)
4367 		return ERR_PTR(-ENOENT);
4368 
4369 	spin_lock_bh(&link_idr_lock);
4370 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
4371 	link = idr_find(&link_idr, id);
4372 	if (link) {
4373 		if (link->id)
4374 			link = bpf_link_inc_not_zero(link);
4375 		else
4376 			link = ERR_PTR(-EAGAIN);
4377 	} else {
4378 		link = ERR_PTR(-ENOENT);
4379 	}
4380 	spin_unlock_bh(&link_idr_lock);
4381 	return link;
4382 }
4383 
4384 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
4385 
bpf_link_get_fd_by_id(const union bpf_attr * attr)4386 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
4387 {
4388 	struct bpf_link *link;
4389 	u32 id = attr->link_id;
4390 	int fd;
4391 
4392 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
4393 		return -EINVAL;
4394 
4395 	if (!capable(CAP_SYS_ADMIN))
4396 		return -EPERM;
4397 
4398 	link = bpf_link_by_id(id);
4399 	if (IS_ERR(link))
4400 		return PTR_ERR(link);
4401 
4402 	fd = bpf_link_new_fd(link);
4403 	if (fd < 0)
4404 		bpf_link_put(link);
4405 
4406 	return fd;
4407 }
4408 
4409 DEFINE_MUTEX(bpf_stats_enabled_mutex);
4410 
bpf_stats_release(struct inode * inode,struct file * file)4411 static int bpf_stats_release(struct inode *inode, struct file *file)
4412 {
4413 	mutex_lock(&bpf_stats_enabled_mutex);
4414 	static_key_slow_dec(&bpf_stats_enabled_key.key);
4415 	mutex_unlock(&bpf_stats_enabled_mutex);
4416 	return 0;
4417 }
4418 
4419 static const struct file_operations bpf_stats_fops = {
4420 	.release = bpf_stats_release,
4421 };
4422 
bpf_enable_runtime_stats(void)4423 static int bpf_enable_runtime_stats(void)
4424 {
4425 	int fd;
4426 
4427 	mutex_lock(&bpf_stats_enabled_mutex);
4428 
4429 	/* Set a very high limit to avoid overflow */
4430 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
4431 		mutex_unlock(&bpf_stats_enabled_mutex);
4432 		return -EBUSY;
4433 	}
4434 
4435 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
4436 	if (fd >= 0)
4437 		static_key_slow_inc(&bpf_stats_enabled_key.key);
4438 
4439 	mutex_unlock(&bpf_stats_enabled_mutex);
4440 	return fd;
4441 }
4442 
4443 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
4444 
bpf_enable_stats(union bpf_attr * attr)4445 static int bpf_enable_stats(union bpf_attr *attr)
4446 {
4447 
4448 	if (CHECK_ATTR(BPF_ENABLE_STATS))
4449 		return -EINVAL;
4450 
4451 	if (!capable(CAP_SYS_ADMIN))
4452 		return -EPERM;
4453 
4454 	switch (attr->enable_stats.type) {
4455 	case BPF_STATS_RUN_TIME:
4456 		return bpf_enable_runtime_stats();
4457 	default:
4458 		break;
4459 	}
4460 	return -EINVAL;
4461 }
4462 
4463 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
4464 
bpf_iter_create(union bpf_attr * attr)4465 static int bpf_iter_create(union bpf_attr *attr)
4466 {
4467 	struct bpf_link *link;
4468 	int err;
4469 
4470 	if (CHECK_ATTR(BPF_ITER_CREATE))
4471 		return -EINVAL;
4472 
4473 	if (attr->iter_create.flags)
4474 		return -EINVAL;
4475 
4476 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
4477 	if (IS_ERR(link))
4478 		return PTR_ERR(link);
4479 
4480 	err = bpf_iter_new_fd(link);
4481 	bpf_link_put(link);
4482 
4483 	return err;
4484 }
4485 
4486 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
4487 
bpf_prog_bind_map(union bpf_attr * attr)4488 static int bpf_prog_bind_map(union bpf_attr *attr)
4489 {
4490 	struct bpf_prog *prog;
4491 	struct bpf_map *map;
4492 	struct bpf_map **used_maps_old, **used_maps_new;
4493 	int i, ret = 0;
4494 
4495 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
4496 		return -EINVAL;
4497 
4498 	if (attr->prog_bind_map.flags)
4499 		return -EINVAL;
4500 
4501 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
4502 	if (IS_ERR(prog))
4503 		return PTR_ERR(prog);
4504 
4505 	map = bpf_map_get(attr->prog_bind_map.map_fd);
4506 	if (IS_ERR(map)) {
4507 		ret = PTR_ERR(map);
4508 		goto out_prog_put;
4509 	}
4510 
4511 	mutex_lock(&prog->aux->used_maps_mutex);
4512 
4513 	used_maps_old = prog->aux->used_maps;
4514 
4515 	for (i = 0; i < prog->aux->used_map_cnt; i++)
4516 		if (used_maps_old[i] == map) {
4517 			bpf_map_put(map);
4518 			goto out_unlock;
4519 		}
4520 
4521 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
4522 				      sizeof(used_maps_new[0]),
4523 				      GFP_KERNEL);
4524 	if (!used_maps_new) {
4525 		ret = -ENOMEM;
4526 		goto out_unlock;
4527 	}
4528 
4529 	memcpy(used_maps_new, used_maps_old,
4530 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
4531 	used_maps_new[prog->aux->used_map_cnt] = map;
4532 
4533 	prog->aux->used_map_cnt++;
4534 	prog->aux->used_maps = used_maps_new;
4535 
4536 	kfree(used_maps_old);
4537 
4538 out_unlock:
4539 	mutex_unlock(&prog->aux->used_maps_mutex);
4540 
4541 	if (ret)
4542 		bpf_map_put(map);
4543 out_prog_put:
4544 	bpf_prog_put(prog);
4545 	return ret;
4546 }
4547 
__sys_bpf(int cmd,bpfptr_t uattr,unsigned int size)4548 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
4549 {
4550 	union bpf_attr attr;
4551 	int err;
4552 
4553 	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
4554 		return -EPERM;
4555 
4556 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
4557 	if (err)
4558 		return err;
4559 	size = min_t(u32, size, sizeof(attr));
4560 
4561 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
4562 	memset(&attr, 0, sizeof(attr));
4563 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
4564 		return -EFAULT;
4565 
4566 	err = security_bpf(cmd, &attr, size);
4567 	if (err < 0)
4568 		return err;
4569 
4570 	switch (cmd) {
4571 	case BPF_MAP_CREATE:
4572 		err = map_create(&attr);
4573 		break;
4574 	case BPF_MAP_LOOKUP_ELEM:
4575 		err = map_lookup_elem(&attr);
4576 		break;
4577 	case BPF_MAP_UPDATE_ELEM:
4578 		err = map_update_elem(&attr, uattr);
4579 		break;
4580 	case BPF_MAP_DELETE_ELEM:
4581 		err = map_delete_elem(&attr);
4582 		break;
4583 	case BPF_MAP_GET_NEXT_KEY:
4584 		err = map_get_next_key(&attr);
4585 		break;
4586 	case BPF_MAP_FREEZE:
4587 		err = map_freeze(&attr);
4588 		break;
4589 	case BPF_PROG_LOAD:
4590 		err = bpf_prog_load(&attr, uattr);
4591 		break;
4592 	case BPF_OBJ_PIN:
4593 		err = bpf_obj_pin(&attr);
4594 		break;
4595 	case BPF_OBJ_GET:
4596 		err = bpf_obj_get(&attr);
4597 		break;
4598 	case BPF_PROG_ATTACH:
4599 		err = bpf_prog_attach(&attr);
4600 		break;
4601 	case BPF_PROG_DETACH:
4602 		err = bpf_prog_detach(&attr);
4603 		break;
4604 	case BPF_PROG_QUERY:
4605 		err = bpf_prog_query(&attr, uattr.user);
4606 		break;
4607 	case BPF_PROG_TEST_RUN:
4608 		err = bpf_prog_test_run(&attr, uattr.user);
4609 		break;
4610 	case BPF_PROG_GET_NEXT_ID:
4611 		err = bpf_obj_get_next_id(&attr, uattr.user,
4612 					  &prog_idr, &prog_idr_lock);
4613 		break;
4614 	case BPF_MAP_GET_NEXT_ID:
4615 		err = bpf_obj_get_next_id(&attr, uattr.user,
4616 					  &map_idr, &map_idr_lock);
4617 		break;
4618 	case BPF_BTF_GET_NEXT_ID:
4619 		err = bpf_obj_get_next_id(&attr, uattr.user,
4620 					  &btf_idr, &btf_idr_lock);
4621 		break;
4622 	case BPF_PROG_GET_FD_BY_ID:
4623 		err = bpf_prog_get_fd_by_id(&attr);
4624 		break;
4625 	case BPF_MAP_GET_FD_BY_ID:
4626 		err = bpf_map_get_fd_by_id(&attr);
4627 		break;
4628 	case BPF_OBJ_GET_INFO_BY_FD:
4629 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
4630 		break;
4631 	case BPF_RAW_TRACEPOINT_OPEN:
4632 		err = bpf_raw_tracepoint_open(&attr);
4633 		break;
4634 	case BPF_BTF_LOAD:
4635 		err = bpf_btf_load(&attr, uattr);
4636 		break;
4637 	case BPF_BTF_GET_FD_BY_ID:
4638 		err = bpf_btf_get_fd_by_id(&attr);
4639 		break;
4640 	case BPF_TASK_FD_QUERY:
4641 		err = bpf_task_fd_query(&attr, uattr.user);
4642 		break;
4643 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
4644 		err = map_lookup_and_delete_elem(&attr);
4645 		break;
4646 	case BPF_MAP_LOOKUP_BATCH:
4647 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
4648 		break;
4649 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
4650 		err = bpf_map_do_batch(&attr, uattr.user,
4651 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
4652 		break;
4653 	case BPF_MAP_UPDATE_BATCH:
4654 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
4655 		break;
4656 	case BPF_MAP_DELETE_BATCH:
4657 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
4658 		break;
4659 	case BPF_LINK_CREATE:
4660 		err = link_create(&attr, uattr);
4661 		break;
4662 	case BPF_LINK_UPDATE:
4663 		err = link_update(&attr);
4664 		break;
4665 	case BPF_LINK_GET_FD_BY_ID:
4666 		err = bpf_link_get_fd_by_id(&attr);
4667 		break;
4668 	case BPF_LINK_GET_NEXT_ID:
4669 		err = bpf_obj_get_next_id(&attr, uattr.user,
4670 					  &link_idr, &link_idr_lock);
4671 		break;
4672 	case BPF_ENABLE_STATS:
4673 		err = bpf_enable_stats(&attr);
4674 		break;
4675 	case BPF_ITER_CREATE:
4676 		err = bpf_iter_create(&attr);
4677 		break;
4678 	case BPF_LINK_DETACH:
4679 		err = link_detach(&attr);
4680 		break;
4681 	case BPF_PROG_BIND_MAP:
4682 		err = bpf_prog_bind_map(&attr);
4683 		break;
4684 	default:
4685 		err = -EINVAL;
4686 		break;
4687 	}
4688 
4689 	return err;
4690 }
4691 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)4692 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
4693 {
4694 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
4695 }
4696 
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)4697 static bool syscall_prog_is_valid_access(int off, int size,
4698 					 enum bpf_access_type type,
4699 					 const struct bpf_prog *prog,
4700 					 struct bpf_insn_access_aux *info)
4701 {
4702 	if (off < 0 || off >= U16_MAX)
4703 		return false;
4704 	if (off % size != 0)
4705 		return false;
4706 	return true;
4707 }
4708 
BPF_CALL_3(bpf_sys_bpf,int,cmd,void *,attr,u32,attr_size)4709 BPF_CALL_3(bpf_sys_bpf, int, cmd, void *, attr, u32, attr_size)
4710 {
4711 	switch (cmd) {
4712 	case BPF_MAP_CREATE:
4713 	case BPF_MAP_UPDATE_ELEM:
4714 	case BPF_MAP_FREEZE:
4715 	case BPF_PROG_LOAD:
4716 	case BPF_BTF_LOAD:
4717 		break;
4718 	/* case BPF_PROG_TEST_RUN:
4719 	 * is not part of this list to prevent recursive test_run
4720 	 */
4721 	default:
4722 		return -EINVAL;
4723 	}
4724 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
4725 }
4726 
4727 static const struct bpf_func_proto bpf_sys_bpf_proto = {
4728 	.func		= bpf_sys_bpf,
4729 	.gpl_only	= false,
4730 	.ret_type	= RET_INTEGER,
4731 	.arg1_type	= ARG_ANYTHING,
4732 	.arg2_type	= ARG_PTR_TO_MEM,
4733 	.arg3_type	= ARG_CONST_SIZE,
4734 };
4735 
4736 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)4737 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
4738 {
4739 	return bpf_base_func_proto(func_id);
4740 }
4741 
BPF_CALL_1(bpf_sys_close,u32,fd)4742 BPF_CALL_1(bpf_sys_close, u32, fd)
4743 {
4744 	/* When bpf program calls this helper there should not be
4745 	 * an fdget() without matching completed fdput().
4746 	 * This helper is allowed in the following callchain only:
4747 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
4748 	 */
4749 	return close_fd(fd);
4750 }
4751 
4752 static const struct bpf_func_proto bpf_sys_close_proto = {
4753 	.func		= bpf_sys_close,
4754 	.gpl_only	= false,
4755 	.ret_type	= RET_INTEGER,
4756 	.arg1_type	= ARG_ANYTHING,
4757 };
4758 
4759 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)4760 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
4761 {
4762 	switch (func_id) {
4763 	case BPF_FUNC_sys_bpf:
4764 		return &bpf_sys_bpf_proto;
4765 	case BPF_FUNC_btf_find_by_name_kind:
4766 		return &bpf_btf_find_by_name_kind_proto;
4767 	case BPF_FUNC_sys_close:
4768 		return &bpf_sys_close_proto;
4769 	default:
4770 		return tracing_prog_func_proto(func_id, prog);
4771 	}
4772 }
4773 
4774 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
4775 	.get_func_proto  = syscall_prog_func_proto,
4776 	.is_valid_access = syscall_prog_is_valid_access,
4777 };
4778 
4779 const struct bpf_prog_ops bpf_syscall_prog_ops = {
4780 	.test_run = bpf_prog_test_run_syscall,
4781 };
4782