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1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3  */
4 #include <linux/bpf.h>
5 #include <linux/bpf_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 #include <trace/hooks/syscall_check.h>
36 
37 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
38 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
39 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
40 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
41 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
42 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
43 			IS_FD_HASH(map))
44 
45 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
46 
47 DEFINE_PER_CPU(int, bpf_prog_active);
48 static DEFINE_IDR(prog_idr);
49 static DEFINE_SPINLOCK(prog_idr_lock);
50 static DEFINE_IDR(map_idr);
51 static DEFINE_SPINLOCK(map_idr_lock);
52 static DEFINE_IDR(link_idr);
53 static DEFINE_SPINLOCK(link_idr_lock);
54 
55 int sysctl_unprivileged_bpf_disabled __read_mostly =
56 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
57 
58 static const struct bpf_map_ops * const bpf_map_types[] = {
59 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
60 #define BPF_MAP_TYPE(_id, _ops) \
61 	[_id] = &_ops,
62 #define BPF_LINK_TYPE(_id, _name)
63 #include <linux/bpf_types.h>
64 #undef BPF_PROG_TYPE
65 #undef BPF_MAP_TYPE
66 #undef BPF_LINK_TYPE
67 };
68 
69 /*
70  * If we're handed a bigger struct than we know of, ensure all the unknown bits
71  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
72  * we don't know about yet.
73  *
74  * There is a ToCToU between this function call and the following
75  * copy_from_user() call. However, this is not a concern since this function is
76  * meant to be a future-proofing of bits.
77  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)78 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
79 			     size_t expected_size,
80 			     size_t actual_size)
81 {
82 	int res;
83 
84 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
85 		return -E2BIG;
86 
87 	if (actual_size <= expected_size)
88 		return 0;
89 
90 	if (uaddr.is_kernel)
91 		res = memchr_inv(uaddr.kernel + expected_size, 0,
92 				 actual_size - expected_size) == NULL;
93 	else
94 		res = check_zeroed_user(uaddr.user + expected_size,
95 					actual_size - expected_size);
96 	if (res < 0)
97 		return res;
98 	return res ? 0 : -E2BIG;
99 }
100 
101 const struct bpf_map_ops bpf_map_offload_ops = {
102 	.map_meta_equal = bpf_map_meta_equal,
103 	.map_alloc = bpf_map_offload_map_alloc,
104 	.map_free = bpf_map_offload_map_free,
105 	.map_check_btf = map_check_no_btf,
106 };
107 
find_and_alloc_map(union bpf_attr * attr)108 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
109 {
110 	const struct bpf_map_ops *ops;
111 	u32 type = attr->map_type;
112 	struct bpf_map *map;
113 	int err;
114 
115 	if (type >= ARRAY_SIZE(bpf_map_types))
116 		return ERR_PTR(-EINVAL);
117 	type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
118 	ops = bpf_map_types[type];
119 	if (!ops)
120 		return ERR_PTR(-EINVAL);
121 
122 	if (ops->map_alloc_check) {
123 		err = ops->map_alloc_check(attr);
124 		if (err)
125 			return ERR_PTR(err);
126 	}
127 	if (attr->map_ifindex)
128 		ops = &bpf_map_offload_ops;
129 	map = ops->map_alloc(attr);
130 	if (IS_ERR(map))
131 		return map;
132 	map->ops = ops;
133 	map->map_type = type;
134 	return map;
135 }
136 
bpf_map_write_active_inc(struct bpf_map * map)137 static void bpf_map_write_active_inc(struct bpf_map *map)
138 {
139 	atomic64_inc(&map->writecnt);
140 }
141 
bpf_map_write_active_dec(struct bpf_map * map)142 static void bpf_map_write_active_dec(struct bpf_map *map)
143 {
144 	atomic64_dec(&map->writecnt);
145 }
146 
bpf_map_write_active(const struct bpf_map * map)147 bool bpf_map_write_active(const struct bpf_map *map)
148 {
149 	return atomic64_read(&map->writecnt) != 0;
150 }
151 
bpf_map_value_size(const struct bpf_map * map)152 static u32 bpf_map_value_size(const struct bpf_map *map)
153 {
154 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
155 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
156 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
157 	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
158 		return round_up(map->value_size, 8) * num_possible_cpus();
159 	else if (IS_FD_MAP(map))
160 		return sizeof(u32);
161 	else
162 		return  map->value_size;
163 }
164 
maybe_wait_bpf_programs(struct bpf_map * map)165 static void maybe_wait_bpf_programs(struct bpf_map *map)
166 {
167 	/* Wait for any running BPF programs to complete so that
168 	 * userspace, when we return to it, knows that all programs
169 	 * that could be running use the new map value.
170 	 */
171 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
172 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
173 		synchronize_rcu();
174 }
175 
bpf_map_update_value(struct bpf_map * map,struct fd f,void * key,void * value,__u64 flags)176 static int bpf_map_update_value(struct bpf_map *map, struct fd f, void *key,
177 				void *value, __u64 flags)
178 {
179 	int err;
180 
181 	/* Need to create a kthread, thus must support schedule */
182 	if (bpf_map_is_dev_bound(map)) {
183 		return bpf_map_offload_update_elem(map, key, value, flags);
184 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
185 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
186 		return map->ops->map_update_elem(map, key, value, flags);
187 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
188 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
189 		return sock_map_update_elem_sys(map, key, value, flags);
190 	} else if (IS_FD_PROG_ARRAY(map)) {
191 		return bpf_fd_array_map_update_elem(map, f.file, key, value,
192 						    flags);
193 	}
194 
195 	bpf_disable_instrumentation();
196 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
197 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
198 		err = bpf_percpu_hash_update(map, key, value, flags);
199 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
200 		err = bpf_percpu_array_update(map, key, value, flags);
201 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
202 		err = bpf_percpu_cgroup_storage_update(map, key, value,
203 						       flags);
204 	} else if (IS_FD_ARRAY(map)) {
205 		rcu_read_lock();
206 		err = bpf_fd_array_map_update_elem(map, f.file, key, value,
207 						   flags);
208 		rcu_read_unlock();
209 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
210 		rcu_read_lock();
211 		err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
212 						  flags);
213 		rcu_read_unlock();
214 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
215 		/* rcu_read_lock() is not needed */
216 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
217 							 flags);
218 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
219 		   map->map_type == BPF_MAP_TYPE_STACK) {
220 		err = map->ops->map_push_elem(map, value, flags);
221 	} else {
222 		rcu_read_lock();
223 		err = map->ops->map_update_elem(map, key, value, flags);
224 		rcu_read_unlock();
225 	}
226 	bpf_enable_instrumentation();
227 	maybe_wait_bpf_programs(map);
228 
229 	return err;
230 }
231 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)232 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
233 			      __u64 flags)
234 {
235 	void *ptr;
236 	int err;
237 
238 	if (bpf_map_is_dev_bound(map))
239 		return bpf_map_offload_lookup_elem(map, key, value);
240 
241 	bpf_disable_instrumentation();
242 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
243 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
244 		err = bpf_percpu_hash_copy(map, key, value);
245 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
246 		err = bpf_percpu_array_copy(map, key, value);
247 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
248 		err = bpf_percpu_cgroup_storage_copy(map, key, value);
249 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
250 		err = bpf_stackmap_copy(map, key, value);
251 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
252 		err = bpf_fd_array_map_lookup_elem(map, key, value);
253 	} else if (IS_FD_HASH(map)) {
254 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
255 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
256 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
257 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
258 		   map->map_type == BPF_MAP_TYPE_STACK) {
259 		err = map->ops->map_peek_elem(map, value);
260 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
261 		/* struct_ops map requires directly updating "value" */
262 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
263 	} else {
264 		rcu_read_lock();
265 		if (map->ops->map_lookup_elem_sys_only)
266 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
267 		else
268 			ptr = map->ops->map_lookup_elem(map, key);
269 		if (IS_ERR(ptr)) {
270 			err = PTR_ERR(ptr);
271 		} else if (!ptr) {
272 			err = -ENOENT;
273 		} else {
274 			err = 0;
275 			if (flags & BPF_F_LOCK)
276 				/* lock 'ptr' and copy everything but lock */
277 				copy_map_value_locked(map, value, ptr, true);
278 			else
279 				copy_map_value(map, value, ptr);
280 			/* mask lock and timer, since value wasn't zero inited */
281 			check_and_init_map_value(map, value);
282 		}
283 		rcu_read_unlock();
284 	}
285 
286 	bpf_enable_instrumentation();
287 	maybe_wait_bpf_programs(map);
288 
289 	return err;
290 }
291 
292 /* Please, do not use this function outside from the map creation path
293  * (e.g. in map update path) without taking care of setting the active
294  * memory cgroup (see at bpf_map_kmalloc_node() for example).
295  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)296 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
297 {
298 	/* We really just want to fail instead of triggering OOM killer
299 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
300 	 * which is used for lower order allocation requests.
301 	 *
302 	 * It has been observed that higher order allocation requests done by
303 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
304 	 * to reclaim memory from the page cache, thus we set
305 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
306 	 */
307 
308 	const gfp_t gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_ACCOUNT;
309 	unsigned int flags = 0;
310 	unsigned long align = 1;
311 	void *area;
312 
313 	if (size >= SIZE_MAX)
314 		return NULL;
315 
316 	/* kmalloc()'ed memory can't be mmap()'ed */
317 	if (mmapable) {
318 		BUG_ON(!PAGE_ALIGNED(size));
319 		align = SHMLBA;
320 		flags = VM_USERMAP;
321 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
322 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
323 				    numa_node);
324 		if (area != NULL)
325 			return area;
326 	}
327 
328 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
329 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
330 			flags, numa_node, __builtin_return_address(0));
331 }
332 
bpf_map_area_alloc(u64 size,int numa_node)333 void *bpf_map_area_alloc(u64 size, int numa_node)
334 {
335 	return __bpf_map_area_alloc(size, numa_node, false);
336 }
337 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)338 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
339 {
340 	return __bpf_map_area_alloc(size, numa_node, true);
341 }
342 
bpf_map_area_free(void * area)343 void bpf_map_area_free(void *area)
344 {
345 	kvfree(area);
346 }
347 
bpf_map_flags_retain_permanent(u32 flags)348 static u32 bpf_map_flags_retain_permanent(u32 flags)
349 {
350 	/* Some map creation flags are not tied to the map object but
351 	 * rather to the map fd instead, so they have no meaning upon
352 	 * map object inspection since multiple file descriptors with
353 	 * different (access) properties can exist here. Thus, given
354 	 * this has zero meaning for the map itself, lets clear these
355 	 * from here.
356 	 */
357 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
358 }
359 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)360 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
361 {
362 	map->map_type = attr->map_type;
363 	map->key_size = attr->key_size;
364 	map->value_size = attr->value_size;
365 	map->max_entries = attr->max_entries;
366 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
367 	map->numa_node = bpf_map_attr_numa_node(attr);
368 }
369 
bpf_map_alloc_id(struct bpf_map * map)370 static int bpf_map_alloc_id(struct bpf_map *map)
371 {
372 	int id;
373 
374 	idr_preload(GFP_KERNEL);
375 	spin_lock_bh(&map_idr_lock);
376 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
377 	if (id > 0)
378 		map->id = id;
379 	spin_unlock_bh(&map_idr_lock);
380 	idr_preload_end();
381 
382 	if (WARN_ON_ONCE(!id))
383 		return -ENOSPC;
384 
385 	return id > 0 ? 0 : id;
386 }
387 
bpf_map_free_id(struct bpf_map * map,bool do_idr_lock)388 void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
389 {
390 	unsigned long flags;
391 
392 	/* Offloaded maps are removed from the IDR store when their device
393 	 * disappears - even if someone holds an fd to them they are unusable,
394 	 * the memory is gone, all ops will fail; they are simply waiting for
395 	 * refcnt to drop to be freed.
396 	 */
397 	if (!map->id)
398 		return;
399 
400 	if (do_idr_lock)
401 		spin_lock_irqsave(&map_idr_lock, flags);
402 	else
403 		__acquire(&map_idr_lock);
404 
405 	idr_remove(&map_idr, map->id);
406 	map->id = 0;
407 
408 	if (do_idr_lock)
409 		spin_unlock_irqrestore(&map_idr_lock, flags);
410 	else
411 		__release(&map_idr_lock);
412 }
413 
414 #ifdef CONFIG_MEMCG_KMEM
bpf_map_save_memcg(struct bpf_map * map)415 static void bpf_map_save_memcg(struct bpf_map *map)
416 {
417 	map->memcg = get_mem_cgroup_from_mm(current->mm);
418 }
419 
bpf_map_release_memcg(struct bpf_map * map)420 static void bpf_map_release_memcg(struct bpf_map *map)
421 {
422 	mem_cgroup_put(map->memcg);
423 }
424 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)425 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
426 			   int node)
427 {
428 	struct mem_cgroup *old_memcg;
429 	void *ptr;
430 
431 	old_memcg = set_active_memcg(map->memcg);
432 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
433 	set_active_memcg(old_memcg);
434 
435 	return ptr;
436 }
437 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)438 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
439 {
440 	struct mem_cgroup *old_memcg;
441 	void *ptr;
442 
443 	old_memcg = set_active_memcg(map->memcg);
444 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
445 	set_active_memcg(old_memcg);
446 
447 	return ptr;
448 }
449 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)450 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
451 				    size_t align, gfp_t flags)
452 {
453 	struct mem_cgroup *old_memcg;
454 	void __percpu *ptr;
455 
456 	old_memcg = set_active_memcg(map->memcg);
457 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
458 	set_active_memcg(old_memcg);
459 
460 	return ptr;
461 }
462 
463 #else
bpf_map_save_memcg(struct bpf_map * map)464 static void bpf_map_save_memcg(struct bpf_map *map)
465 {
466 }
467 
bpf_map_release_memcg(struct bpf_map * map)468 static void bpf_map_release_memcg(struct bpf_map *map)
469 {
470 }
471 #endif
472 
473 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)474 static void bpf_map_free_deferred(struct work_struct *work)
475 {
476 	struct bpf_map *map = container_of(work, struct bpf_map, work);
477 
478 	security_bpf_map_free(map);
479 	bpf_map_release_memcg(map);
480 	/* implementation dependent freeing */
481 	map->ops->map_free(map);
482 }
483 
bpf_map_put_uref(struct bpf_map * map)484 static void bpf_map_put_uref(struct bpf_map *map)
485 {
486 	if (atomic64_dec_and_test(&map->usercnt)) {
487 		if (map->ops->map_release_uref)
488 			map->ops->map_release_uref(map);
489 	}
490 }
491 
492 /* decrement map refcnt and schedule it for freeing via workqueue
493  * (unrelying map implementation ops->map_free() might sleep)
494  */
__bpf_map_put(struct bpf_map * map,bool do_idr_lock)495 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
496 {
497 	if (atomic64_dec_and_test(&map->refcnt)) {
498 		/* bpf_map_free_id() must be called first */
499 		bpf_map_free_id(map, do_idr_lock);
500 		btf_put(map->btf);
501 		INIT_WORK(&map->work, bpf_map_free_deferred);
502 		schedule_work(&map->work);
503 	}
504 }
505 
bpf_map_put(struct bpf_map * map)506 void bpf_map_put(struct bpf_map *map)
507 {
508 	__bpf_map_put(map, true);
509 }
510 EXPORT_SYMBOL_GPL(bpf_map_put);
511 
bpf_map_put_with_uref(struct bpf_map * map)512 void bpf_map_put_with_uref(struct bpf_map *map)
513 {
514 	bpf_map_put_uref(map);
515 	bpf_map_put(map);
516 }
517 
bpf_map_release(struct inode * inode,struct file * filp)518 static int bpf_map_release(struct inode *inode, struct file *filp)
519 {
520 	struct bpf_map *map = filp->private_data;
521 
522 	if (map->ops->map_release)
523 		map->ops->map_release(map, filp);
524 
525 	bpf_map_put_with_uref(map);
526 	return 0;
527 }
528 
map_get_sys_perms(struct bpf_map * map,struct fd f)529 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
530 {
531 	fmode_t mode = f.file->f_mode;
532 
533 	/* Our file permissions may have been overridden by global
534 	 * map permissions facing syscall side.
535 	 */
536 	if (READ_ONCE(map->frozen))
537 		mode &= ~FMODE_CAN_WRITE;
538 	return mode;
539 }
540 
541 #ifdef CONFIG_PROC_FS
542 /* Provides an approximation of the map's memory footprint.
543  * Used only to provide a backward compatibility and display
544  * a reasonable "memlock" info.
545  */
bpf_map_memory_footprint(const struct bpf_map * map)546 static unsigned long bpf_map_memory_footprint(const struct bpf_map *map)
547 {
548 	unsigned long size;
549 
550 	size = round_up(map->key_size + bpf_map_value_size(map), 8);
551 
552 	return round_up(map->max_entries * size, PAGE_SIZE);
553 }
554 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)555 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
556 {
557 	const struct bpf_map *map = filp->private_data;
558 	const struct bpf_array *array;
559 	u32 type = 0, jited = 0;
560 
561 	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
562 		array = container_of(map, struct bpf_array, map);
563 		spin_lock(&array->aux->owner.lock);
564 		type  = array->aux->owner.type;
565 		jited = array->aux->owner.jited;
566 		spin_unlock(&array->aux->owner.lock);
567 	}
568 
569 	seq_printf(m,
570 		   "map_type:\t%u\n"
571 		   "key_size:\t%u\n"
572 		   "value_size:\t%u\n"
573 		   "max_entries:\t%u\n"
574 		   "map_flags:\t%#x\n"
575 		   "memlock:\t%lu\n"
576 		   "map_id:\t%u\n"
577 		   "frozen:\t%u\n",
578 		   map->map_type,
579 		   map->key_size,
580 		   map->value_size,
581 		   map->max_entries,
582 		   map->map_flags,
583 		   bpf_map_memory_footprint(map),
584 		   map->id,
585 		   READ_ONCE(map->frozen));
586 	if (type) {
587 		seq_printf(m, "owner_prog_type:\t%u\n", type);
588 		seq_printf(m, "owner_jited:\t%u\n", jited);
589 	}
590 }
591 #endif
592 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)593 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
594 			      loff_t *ppos)
595 {
596 	/* We need this handler such that alloc_file() enables
597 	 * f_mode with FMODE_CAN_READ.
598 	 */
599 	return -EINVAL;
600 }
601 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)602 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
603 			       size_t siz, loff_t *ppos)
604 {
605 	/* We need this handler such that alloc_file() enables
606 	 * f_mode with FMODE_CAN_WRITE.
607 	 */
608 	return -EINVAL;
609 }
610 
611 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)612 static void bpf_map_mmap_open(struct vm_area_struct *vma)
613 {
614 	struct bpf_map *map = vma->vm_file->private_data;
615 
616 	if (vma->vm_flags & VM_MAYWRITE)
617 		bpf_map_write_active_inc(map);
618 }
619 
620 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)621 static void bpf_map_mmap_close(struct vm_area_struct *vma)
622 {
623 	struct bpf_map *map = vma->vm_file->private_data;
624 
625 	if (vma->vm_flags & VM_MAYWRITE)
626 		bpf_map_write_active_dec(map);
627 }
628 
629 static const struct vm_operations_struct bpf_map_default_vmops = {
630 	.open		= bpf_map_mmap_open,
631 	.close		= bpf_map_mmap_close,
632 };
633 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)634 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
635 {
636 	struct bpf_map *map = filp->private_data;
637 	int err;
638 
639 	if (!map->ops->map_mmap || map_value_has_spin_lock(map) ||
640 	    map_value_has_timer(map))
641 		return -ENOTSUPP;
642 
643 	if (!(vma->vm_flags & VM_SHARED))
644 		return -EINVAL;
645 
646 	mutex_lock(&map->freeze_mutex);
647 
648 	if (vma->vm_flags & VM_WRITE) {
649 		if (map->frozen) {
650 			err = -EPERM;
651 			goto out;
652 		}
653 		/* map is meant to be read-only, so do not allow mapping as
654 		 * writable, because it's possible to leak a writable page
655 		 * reference and allows user-space to still modify it after
656 		 * freezing, while verifier will assume contents do not change
657 		 */
658 		if (map->map_flags & BPF_F_RDONLY_PROG) {
659 			err = -EACCES;
660 			goto out;
661 		}
662 	}
663 
664 	/* set default open/close callbacks */
665 	vma->vm_ops = &bpf_map_default_vmops;
666 	vma->vm_private_data = map;
667 	vma->vm_flags &= ~VM_MAYEXEC;
668 	if (!(vma->vm_flags & VM_WRITE))
669 		/* disallow re-mapping with PROT_WRITE */
670 		vma->vm_flags &= ~VM_MAYWRITE;
671 
672 	err = map->ops->map_mmap(map, vma);
673 	if (err)
674 		goto out;
675 
676 	if (vma->vm_flags & VM_MAYWRITE)
677 		bpf_map_write_active_inc(map);
678 out:
679 	mutex_unlock(&map->freeze_mutex);
680 	return err;
681 }
682 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)683 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
684 {
685 	struct bpf_map *map = filp->private_data;
686 
687 	if (map->ops->map_poll)
688 		return map->ops->map_poll(map, filp, pts);
689 
690 	return EPOLLERR;
691 }
692 
693 const struct file_operations bpf_map_fops = {
694 #ifdef CONFIG_PROC_FS
695 	.show_fdinfo	= bpf_map_show_fdinfo,
696 #endif
697 	.release	= bpf_map_release,
698 	.read		= bpf_dummy_read,
699 	.write		= bpf_dummy_write,
700 	.mmap		= bpf_map_mmap,
701 	.poll		= bpf_map_poll,
702 };
703 
bpf_map_new_fd(struct bpf_map * map,int flags)704 int bpf_map_new_fd(struct bpf_map *map, int flags)
705 {
706 	int ret;
707 
708 	ret = security_bpf_map(map, OPEN_FMODE(flags));
709 	if (ret < 0)
710 		return ret;
711 
712 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
713 				flags | O_CLOEXEC);
714 }
715 
bpf_get_file_flag(int flags)716 int bpf_get_file_flag(int flags)
717 {
718 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
719 		return -EINVAL;
720 	if (flags & BPF_F_RDONLY)
721 		return O_RDONLY;
722 	if (flags & BPF_F_WRONLY)
723 		return O_WRONLY;
724 	return O_RDWR;
725 }
726 
727 /* helper macro to check that unused fields 'union bpf_attr' are zero */
728 #define CHECK_ATTR(CMD) \
729 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
730 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
731 		   sizeof(*attr) - \
732 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
733 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
734 
735 /* dst and src must have at least "size" number of bytes.
736  * Return strlen on success and < 0 on error.
737  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)738 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
739 {
740 	const char *end = src + size;
741 	const char *orig_src = src;
742 
743 	memset(dst, 0, size);
744 	/* Copy all isalnum(), '_' and '.' chars. */
745 	while (src < end && *src) {
746 		if (!isalnum(*src) &&
747 		    *src != '_' && *src != '.')
748 			return -EINVAL;
749 		*dst++ = *src++;
750 	}
751 
752 	/* No '\0' found in "size" number of bytes */
753 	if (src == end)
754 		return -EINVAL;
755 
756 	return src - orig_src;
757 }
758 
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)759 int map_check_no_btf(const struct bpf_map *map,
760 		     const struct btf *btf,
761 		     const struct btf_type *key_type,
762 		     const struct btf_type *value_type)
763 {
764 	return -ENOTSUPP;
765 }
766 
map_check_btf(struct bpf_map * map,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)767 static int map_check_btf(struct bpf_map *map, const struct btf *btf,
768 			 u32 btf_key_id, u32 btf_value_id)
769 {
770 	const struct btf_type *key_type, *value_type;
771 	u32 key_size, value_size;
772 	int ret = 0;
773 
774 	/* Some maps allow key to be unspecified. */
775 	if (btf_key_id) {
776 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
777 		if (!key_type || key_size != map->key_size)
778 			return -EINVAL;
779 	} else {
780 		key_type = btf_type_by_id(btf, 0);
781 		if (!map->ops->map_check_btf)
782 			return -EINVAL;
783 	}
784 
785 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
786 	if (!value_type || value_size != map->value_size)
787 		return -EINVAL;
788 
789 	map->spin_lock_off = btf_find_spin_lock(btf, value_type);
790 
791 	if (map_value_has_spin_lock(map)) {
792 		if (map->map_flags & BPF_F_RDONLY_PROG)
793 			return -EACCES;
794 		if (map->map_type != BPF_MAP_TYPE_HASH &&
795 		    map->map_type != BPF_MAP_TYPE_ARRAY &&
796 		    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
797 		    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
798 		    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
799 		    map->map_type != BPF_MAP_TYPE_TASK_STORAGE)
800 			return -ENOTSUPP;
801 		if (map->spin_lock_off + sizeof(struct bpf_spin_lock) >
802 		    map->value_size) {
803 			WARN_ONCE(1,
804 				  "verifier bug spin_lock_off %d value_size %d\n",
805 				  map->spin_lock_off, map->value_size);
806 			return -EFAULT;
807 		}
808 	}
809 
810 	map->timer_off = btf_find_timer(btf, value_type);
811 	if (map_value_has_timer(map)) {
812 		if (map->map_flags & BPF_F_RDONLY_PROG)
813 			return -EACCES;
814 		if (map->map_type != BPF_MAP_TYPE_HASH &&
815 		    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
816 		    map->map_type != BPF_MAP_TYPE_ARRAY)
817 			return -EOPNOTSUPP;
818 	}
819 
820 	if (map->ops->map_check_btf)
821 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
822 
823 	return ret;
824 }
825 
826 #define BPF_MAP_CREATE_LAST_FIELD btf_vmlinux_value_type_id
827 /* called via syscall */
map_create(union bpf_attr * attr)828 static int map_create(union bpf_attr *attr)
829 {
830 	int numa_node = bpf_map_attr_numa_node(attr);
831 	struct bpf_map *map;
832 	int f_flags;
833 	int err;
834 
835 	err = CHECK_ATTR(BPF_MAP_CREATE);
836 	if (err)
837 		return -EINVAL;
838 
839 	if (attr->btf_vmlinux_value_type_id) {
840 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
841 		    attr->btf_key_type_id || attr->btf_value_type_id)
842 			return -EINVAL;
843 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
844 		return -EINVAL;
845 	}
846 
847 	f_flags = bpf_get_file_flag(attr->map_flags);
848 	if (f_flags < 0)
849 		return f_flags;
850 
851 	if (numa_node != NUMA_NO_NODE &&
852 	    ((unsigned int)numa_node >= nr_node_ids ||
853 	     !node_online(numa_node)))
854 		return -EINVAL;
855 
856 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
857 	map = find_and_alloc_map(attr);
858 	if (IS_ERR(map))
859 		return PTR_ERR(map);
860 
861 	err = bpf_obj_name_cpy(map->name, attr->map_name,
862 			       sizeof(attr->map_name));
863 	if (err < 0)
864 		goto free_map;
865 
866 	atomic64_set(&map->refcnt, 1);
867 	atomic64_set(&map->usercnt, 1);
868 	mutex_init(&map->freeze_mutex);
869 
870 	map->spin_lock_off = -EINVAL;
871 	map->timer_off = -EINVAL;
872 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
873 	    /* Even the map's value is a kernel's struct,
874 	     * the bpf_prog.o must have BTF to begin with
875 	     * to figure out the corresponding kernel's
876 	     * counter part.  Thus, attr->btf_fd has
877 	     * to be valid also.
878 	     */
879 	    attr->btf_vmlinux_value_type_id) {
880 		struct btf *btf;
881 
882 		btf = btf_get_by_fd(attr->btf_fd);
883 		if (IS_ERR(btf)) {
884 			err = PTR_ERR(btf);
885 			goto free_map;
886 		}
887 		if (btf_is_kernel(btf)) {
888 			btf_put(btf);
889 			err = -EACCES;
890 			goto free_map;
891 		}
892 		map->btf = btf;
893 
894 		if (attr->btf_value_type_id) {
895 			err = map_check_btf(map, btf, attr->btf_key_type_id,
896 					    attr->btf_value_type_id);
897 			if (err)
898 				goto free_map;
899 		}
900 
901 		map->btf_key_type_id = attr->btf_key_type_id;
902 		map->btf_value_type_id = attr->btf_value_type_id;
903 		map->btf_vmlinux_value_type_id =
904 			attr->btf_vmlinux_value_type_id;
905 	}
906 
907 	err = security_bpf_map_alloc(map);
908 	if (err)
909 		goto free_map;
910 
911 	err = bpf_map_alloc_id(map);
912 	if (err)
913 		goto free_map_sec;
914 
915 	bpf_map_save_memcg(map);
916 
917 	err = bpf_map_new_fd(map, f_flags);
918 	if (err < 0) {
919 		/* failed to allocate fd.
920 		 * bpf_map_put_with_uref() is needed because the above
921 		 * bpf_map_alloc_id() has published the map
922 		 * to the userspace and the userspace may
923 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
924 		 */
925 		bpf_map_put_with_uref(map);
926 		return err;
927 	}
928 
929 	return err;
930 
931 free_map_sec:
932 	security_bpf_map_free(map);
933 free_map:
934 	btf_put(map->btf);
935 	map->ops->map_free(map);
936 	return err;
937 }
938 
939 /* if error is returned, fd is released.
940  * On success caller should complete fd access with matching fdput()
941  */
__bpf_map_get(struct fd f)942 struct bpf_map *__bpf_map_get(struct fd f)
943 {
944 	if (!f.file)
945 		return ERR_PTR(-EBADF);
946 	if (f.file->f_op != &bpf_map_fops) {
947 		fdput(f);
948 		return ERR_PTR(-EINVAL);
949 	}
950 
951 	return f.file->private_data;
952 }
953 
bpf_map_inc(struct bpf_map * map)954 void bpf_map_inc(struct bpf_map *map)
955 {
956 	atomic64_inc(&map->refcnt);
957 }
958 EXPORT_SYMBOL_GPL(bpf_map_inc);
959 
bpf_map_inc_with_uref(struct bpf_map * map)960 void bpf_map_inc_with_uref(struct bpf_map *map)
961 {
962 	atomic64_inc(&map->refcnt);
963 	atomic64_inc(&map->usercnt);
964 }
965 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
966 
bpf_map_get(u32 ufd)967 struct bpf_map *bpf_map_get(u32 ufd)
968 {
969 	struct fd f = fdget(ufd);
970 	struct bpf_map *map;
971 
972 	map = __bpf_map_get(f);
973 	if (IS_ERR(map))
974 		return map;
975 
976 	bpf_map_inc(map);
977 	fdput(f);
978 
979 	return map;
980 }
981 
bpf_map_get_with_uref(u32 ufd)982 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
983 {
984 	struct fd f = fdget(ufd);
985 	struct bpf_map *map;
986 
987 	map = __bpf_map_get(f);
988 	if (IS_ERR(map))
989 		return map;
990 
991 	bpf_map_inc_with_uref(map);
992 	fdput(f);
993 
994 	return map;
995 }
996 
997 /* map_idr_lock should have been held */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)998 static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
999 {
1000 	int refold;
1001 
1002 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1003 	if (!refold)
1004 		return ERR_PTR(-ENOENT);
1005 	if (uref)
1006 		atomic64_inc(&map->usercnt);
1007 
1008 	return map;
1009 }
1010 
bpf_map_inc_not_zero(struct bpf_map * map)1011 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1012 {
1013 	spin_lock_bh(&map_idr_lock);
1014 	map = __bpf_map_inc_not_zero(map, false);
1015 	spin_unlock_bh(&map_idr_lock);
1016 
1017 	return map;
1018 }
1019 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1020 
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1021 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1022 {
1023 	return -ENOTSUPP;
1024 }
1025 
__bpf_copy_key(void __user * ukey,u64 key_size)1026 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1027 {
1028 	if (key_size)
1029 		return vmemdup_user(ukey, key_size);
1030 
1031 	if (ukey)
1032 		return ERR_PTR(-EINVAL);
1033 
1034 	return NULL;
1035 }
1036 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1037 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1038 {
1039 	if (key_size)
1040 		return kvmemdup_bpfptr(ukey, key_size);
1041 
1042 	if (!bpfptr_is_null(ukey))
1043 		return ERR_PTR(-EINVAL);
1044 
1045 	return NULL;
1046 }
1047 
1048 /* last field in 'union bpf_attr' used by this command */
1049 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1050 
map_lookup_elem(union bpf_attr * attr)1051 static int map_lookup_elem(union bpf_attr *attr)
1052 {
1053 	void __user *ukey = u64_to_user_ptr(attr->key);
1054 	void __user *uvalue = u64_to_user_ptr(attr->value);
1055 	int ufd = attr->map_fd;
1056 	struct bpf_map *map;
1057 	void *key, *value;
1058 	u32 value_size;
1059 	struct fd f;
1060 	int err;
1061 
1062 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1063 		return -EINVAL;
1064 
1065 	if (attr->flags & ~BPF_F_LOCK)
1066 		return -EINVAL;
1067 
1068 	f = fdget(ufd);
1069 	map = __bpf_map_get(f);
1070 	if (IS_ERR(map))
1071 		return PTR_ERR(map);
1072 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1073 		err = -EPERM;
1074 		goto err_put;
1075 	}
1076 
1077 	if ((attr->flags & BPF_F_LOCK) &&
1078 	    !map_value_has_spin_lock(map)) {
1079 		err = -EINVAL;
1080 		goto err_put;
1081 	}
1082 
1083 	key = __bpf_copy_key(ukey, map->key_size);
1084 	if (IS_ERR(key)) {
1085 		err = PTR_ERR(key);
1086 		goto err_put;
1087 	}
1088 
1089 	value_size = bpf_map_value_size(map);
1090 
1091 	err = -ENOMEM;
1092 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1093 	if (!value)
1094 		goto free_key;
1095 
1096 	err = bpf_map_copy_value(map, key, value, attr->flags);
1097 	if (err)
1098 		goto free_value;
1099 
1100 	err = -EFAULT;
1101 	if (copy_to_user(uvalue, value, value_size) != 0)
1102 		goto free_value;
1103 
1104 	err = 0;
1105 
1106 free_value:
1107 	kvfree(value);
1108 free_key:
1109 	kvfree(key);
1110 err_put:
1111 	fdput(f);
1112 	return err;
1113 }
1114 
1115 
1116 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1117 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1118 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1119 {
1120 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1121 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1122 	int ufd = attr->map_fd;
1123 	struct bpf_map *map;
1124 	void *key, *value;
1125 	u32 value_size;
1126 	struct fd f;
1127 	int err;
1128 
1129 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1130 		return -EINVAL;
1131 
1132 	f = fdget(ufd);
1133 	map = __bpf_map_get(f);
1134 	if (IS_ERR(map))
1135 		return PTR_ERR(map);
1136 	bpf_map_write_active_inc(map);
1137 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1138 		err = -EPERM;
1139 		goto err_put;
1140 	}
1141 
1142 	if ((attr->flags & BPF_F_LOCK) &&
1143 	    !map_value_has_spin_lock(map)) {
1144 		err = -EINVAL;
1145 		goto err_put;
1146 	}
1147 
1148 	key = ___bpf_copy_key(ukey, map->key_size);
1149 	if (IS_ERR(key)) {
1150 		err = PTR_ERR(key);
1151 		goto err_put;
1152 	}
1153 
1154 	value_size = bpf_map_value_size(map);
1155 
1156 	err = -ENOMEM;
1157 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1158 	if (!value)
1159 		goto free_key;
1160 
1161 	err = -EFAULT;
1162 	if (copy_from_bpfptr(value, uvalue, value_size) != 0)
1163 		goto free_value;
1164 
1165 	err = bpf_map_update_value(map, f, key, value, attr->flags);
1166 
1167 free_value:
1168 	kvfree(value);
1169 free_key:
1170 	kvfree(key);
1171 err_put:
1172 	bpf_map_write_active_dec(map);
1173 	fdput(f);
1174 	return err;
1175 }
1176 
1177 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1178 
map_delete_elem(union bpf_attr * attr)1179 static int map_delete_elem(union bpf_attr *attr)
1180 {
1181 	void __user *ukey = u64_to_user_ptr(attr->key);
1182 	int ufd = attr->map_fd;
1183 	struct bpf_map *map;
1184 	struct fd f;
1185 	void *key;
1186 	int err;
1187 
1188 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1189 		return -EINVAL;
1190 
1191 	f = fdget(ufd);
1192 	map = __bpf_map_get(f);
1193 	if (IS_ERR(map))
1194 		return PTR_ERR(map);
1195 	bpf_map_write_active_inc(map);
1196 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1197 		err = -EPERM;
1198 		goto err_put;
1199 	}
1200 
1201 	key = __bpf_copy_key(ukey, map->key_size);
1202 	if (IS_ERR(key)) {
1203 		err = PTR_ERR(key);
1204 		goto err_put;
1205 	}
1206 
1207 	if (bpf_map_is_dev_bound(map)) {
1208 		err = bpf_map_offload_delete_elem(map, key);
1209 		goto out;
1210 	} else if (IS_FD_PROG_ARRAY(map) ||
1211 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1212 		/* These maps require sleepable context */
1213 		err = map->ops->map_delete_elem(map, key);
1214 		goto out;
1215 	}
1216 
1217 	bpf_disable_instrumentation();
1218 	rcu_read_lock();
1219 	err = map->ops->map_delete_elem(map, key);
1220 	rcu_read_unlock();
1221 	bpf_enable_instrumentation();
1222 	maybe_wait_bpf_programs(map);
1223 out:
1224 	kvfree(key);
1225 err_put:
1226 	bpf_map_write_active_dec(map);
1227 	fdput(f);
1228 	return err;
1229 }
1230 
1231 /* last field in 'union bpf_attr' used by this command */
1232 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1233 
map_get_next_key(union bpf_attr * attr)1234 static int map_get_next_key(union bpf_attr *attr)
1235 {
1236 	void __user *ukey = u64_to_user_ptr(attr->key);
1237 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1238 	int ufd = attr->map_fd;
1239 	struct bpf_map *map;
1240 	void *key, *next_key;
1241 	struct fd f;
1242 	int err;
1243 
1244 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1245 		return -EINVAL;
1246 
1247 	f = fdget(ufd);
1248 	map = __bpf_map_get(f);
1249 	if (IS_ERR(map))
1250 		return PTR_ERR(map);
1251 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1252 		err = -EPERM;
1253 		goto err_put;
1254 	}
1255 
1256 	if (ukey) {
1257 		key = __bpf_copy_key(ukey, map->key_size);
1258 		if (IS_ERR(key)) {
1259 			err = PTR_ERR(key);
1260 			goto err_put;
1261 		}
1262 	} else {
1263 		key = NULL;
1264 	}
1265 
1266 	err = -ENOMEM;
1267 	next_key = kvmalloc(map->key_size, GFP_USER);
1268 	if (!next_key)
1269 		goto free_key;
1270 
1271 	if (bpf_map_is_dev_bound(map)) {
1272 		err = bpf_map_offload_get_next_key(map, key, next_key);
1273 		goto out;
1274 	}
1275 
1276 	rcu_read_lock();
1277 	err = map->ops->map_get_next_key(map, key, next_key);
1278 	rcu_read_unlock();
1279 out:
1280 	if (err)
1281 		goto free_next_key;
1282 
1283 	err = -EFAULT;
1284 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1285 		goto free_next_key;
1286 
1287 	err = 0;
1288 
1289 free_next_key:
1290 	kvfree(next_key);
1291 free_key:
1292 	kvfree(key);
1293 err_put:
1294 	fdput(f);
1295 	return err;
1296 }
1297 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1298 int generic_map_delete_batch(struct bpf_map *map,
1299 			     const union bpf_attr *attr,
1300 			     union bpf_attr __user *uattr)
1301 {
1302 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1303 	u32 cp, max_count;
1304 	int err = 0;
1305 	void *key;
1306 
1307 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1308 		return -EINVAL;
1309 
1310 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1311 	    !map_value_has_spin_lock(map)) {
1312 		return -EINVAL;
1313 	}
1314 
1315 	max_count = attr->batch.count;
1316 	if (!max_count)
1317 		return 0;
1318 
1319 	if (put_user(0, &uattr->batch.count))
1320 		return -EFAULT;
1321 
1322 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1323 	if (!key)
1324 		return -ENOMEM;
1325 
1326 	for (cp = 0; cp < max_count; cp++) {
1327 		err = -EFAULT;
1328 		if (copy_from_user(key, keys + cp * map->key_size,
1329 				   map->key_size))
1330 			break;
1331 
1332 		if (bpf_map_is_dev_bound(map)) {
1333 			err = bpf_map_offload_delete_elem(map, key);
1334 			break;
1335 		}
1336 
1337 		bpf_disable_instrumentation();
1338 		rcu_read_lock();
1339 		err = map->ops->map_delete_elem(map, key);
1340 		rcu_read_unlock();
1341 		bpf_enable_instrumentation();
1342 		maybe_wait_bpf_programs(map);
1343 		if (err)
1344 			break;
1345 		cond_resched();
1346 	}
1347 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1348 		err = -EFAULT;
1349 
1350 	kvfree(key);
1351 	return err;
1352 }
1353 
generic_map_update_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1354 int generic_map_update_batch(struct bpf_map *map,
1355 			     const union bpf_attr *attr,
1356 			     union bpf_attr __user *uattr)
1357 {
1358 	void __user *values = u64_to_user_ptr(attr->batch.values);
1359 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1360 	u32 value_size, cp, max_count;
1361 	int ufd = attr->batch.map_fd;
1362 	void *key, *value;
1363 	struct fd f;
1364 	int err = 0;
1365 
1366 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1367 		return -EINVAL;
1368 
1369 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1370 	    !map_value_has_spin_lock(map)) {
1371 		return -EINVAL;
1372 	}
1373 
1374 	value_size = bpf_map_value_size(map);
1375 
1376 	max_count = attr->batch.count;
1377 	if (!max_count)
1378 		return 0;
1379 
1380 	if (put_user(0, &uattr->batch.count))
1381 		return -EFAULT;
1382 
1383 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1384 	if (!key)
1385 		return -ENOMEM;
1386 
1387 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1388 	if (!value) {
1389 		kvfree(key);
1390 		return -ENOMEM;
1391 	}
1392 
1393 	f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */
1394 	for (cp = 0; cp < max_count; cp++) {
1395 		err = -EFAULT;
1396 		if (copy_from_user(key, keys + cp * map->key_size,
1397 		    map->key_size) ||
1398 		    copy_from_user(value, values + cp * value_size, value_size))
1399 			break;
1400 
1401 		err = bpf_map_update_value(map, f, key, value,
1402 					   attr->batch.elem_flags);
1403 
1404 		if (err)
1405 			break;
1406 		cond_resched();
1407 	}
1408 
1409 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1410 		err = -EFAULT;
1411 
1412 	kvfree(value);
1413 	kvfree(key);
1414 	fdput(f);
1415 	return err;
1416 }
1417 
1418 #define MAP_LOOKUP_RETRIES 3
1419 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1420 int generic_map_lookup_batch(struct bpf_map *map,
1421 				    const union bpf_attr *attr,
1422 				    union bpf_attr __user *uattr)
1423 {
1424 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
1425 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1426 	void __user *values = u64_to_user_ptr(attr->batch.values);
1427 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1428 	void *buf, *buf_prevkey, *prev_key, *key, *value;
1429 	int err, retry = MAP_LOOKUP_RETRIES;
1430 	u32 value_size, cp, max_count;
1431 
1432 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1433 		return -EINVAL;
1434 
1435 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1436 	    !map_value_has_spin_lock(map))
1437 		return -EINVAL;
1438 
1439 	value_size = bpf_map_value_size(map);
1440 
1441 	max_count = attr->batch.count;
1442 	if (!max_count)
1443 		return 0;
1444 
1445 	if (put_user(0, &uattr->batch.count))
1446 		return -EFAULT;
1447 
1448 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1449 	if (!buf_prevkey)
1450 		return -ENOMEM;
1451 
1452 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
1453 	if (!buf) {
1454 		kvfree(buf_prevkey);
1455 		return -ENOMEM;
1456 	}
1457 
1458 	err = -EFAULT;
1459 	prev_key = NULL;
1460 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
1461 		goto free_buf;
1462 	key = buf;
1463 	value = key + map->key_size;
1464 	if (ubatch)
1465 		prev_key = buf_prevkey;
1466 
1467 	for (cp = 0; cp < max_count;) {
1468 		rcu_read_lock();
1469 		err = map->ops->map_get_next_key(map, prev_key, key);
1470 		rcu_read_unlock();
1471 		if (err)
1472 			break;
1473 		err = bpf_map_copy_value(map, key, value,
1474 					 attr->batch.elem_flags);
1475 
1476 		if (err == -ENOENT) {
1477 			if (retry) {
1478 				retry--;
1479 				continue;
1480 			}
1481 			err = -EINTR;
1482 			break;
1483 		}
1484 
1485 		if (err)
1486 			goto free_buf;
1487 
1488 		if (copy_to_user(keys + cp * map->key_size, key,
1489 				 map->key_size)) {
1490 			err = -EFAULT;
1491 			goto free_buf;
1492 		}
1493 		if (copy_to_user(values + cp * value_size, value, value_size)) {
1494 			err = -EFAULT;
1495 			goto free_buf;
1496 		}
1497 
1498 		if (!prev_key)
1499 			prev_key = buf_prevkey;
1500 
1501 		swap(prev_key, key);
1502 		retry = MAP_LOOKUP_RETRIES;
1503 		cp++;
1504 		cond_resched();
1505 	}
1506 
1507 	if (err == -EFAULT)
1508 		goto free_buf;
1509 
1510 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
1511 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
1512 		err = -EFAULT;
1513 
1514 free_buf:
1515 	kvfree(buf_prevkey);
1516 	kvfree(buf);
1517 	return err;
1518 }
1519 
1520 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
1521 
map_lookup_and_delete_elem(union bpf_attr * attr)1522 static int map_lookup_and_delete_elem(union bpf_attr *attr)
1523 {
1524 	void __user *ukey = u64_to_user_ptr(attr->key);
1525 	void __user *uvalue = u64_to_user_ptr(attr->value);
1526 	int ufd = attr->map_fd;
1527 	struct bpf_map *map;
1528 	void *key, *value;
1529 	u32 value_size;
1530 	struct fd f;
1531 	int err;
1532 
1533 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
1534 		return -EINVAL;
1535 
1536 	if (attr->flags & ~BPF_F_LOCK)
1537 		return -EINVAL;
1538 
1539 	f = fdget(ufd);
1540 	map = __bpf_map_get(f);
1541 	if (IS_ERR(map))
1542 		return PTR_ERR(map);
1543 	bpf_map_write_active_inc(map);
1544 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
1545 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1546 		err = -EPERM;
1547 		goto err_put;
1548 	}
1549 
1550 	if (attr->flags &&
1551 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
1552 	     map->map_type == BPF_MAP_TYPE_STACK)) {
1553 		err = -EINVAL;
1554 		goto err_put;
1555 	}
1556 
1557 	if ((attr->flags & BPF_F_LOCK) &&
1558 	    !map_value_has_spin_lock(map)) {
1559 		err = -EINVAL;
1560 		goto err_put;
1561 	}
1562 
1563 	key = __bpf_copy_key(ukey, map->key_size);
1564 	if (IS_ERR(key)) {
1565 		err = PTR_ERR(key);
1566 		goto err_put;
1567 	}
1568 
1569 	value_size = bpf_map_value_size(map);
1570 
1571 	err = -ENOMEM;
1572 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1573 	if (!value)
1574 		goto free_key;
1575 
1576 	err = -ENOTSUPP;
1577 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
1578 	    map->map_type == BPF_MAP_TYPE_STACK) {
1579 		err = map->ops->map_pop_elem(map, value);
1580 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
1581 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
1582 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
1583 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
1584 		if (!bpf_map_is_dev_bound(map)) {
1585 			bpf_disable_instrumentation();
1586 			rcu_read_lock();
1587 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
1588 			rcu_read_unlock();
1589 			bpf_enable_instrumentation();
1590 		}
1591 	}
1592 
1593 	if (err)
1594 		goto free_value;
1595 
1596 	if (copy_to_user(uvalue, value, value_size) != 0) {
1597 		err = -EFAULT;
1598 		goto free_value;
1599 	}
1600 
1601 	err = 0;
1602 
1603 free_value:
1604 	kvfree(value);
1605 free_key:
1606 	kvfree(key);
1607 err_put:
1608 	bpf_map_write_active_dec(map);
1609 	fdput(f);
1610 	return err;
1611 }
1612 
1613 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
1614 
map_freeze(const union bpf_attr * attr)1615 static int map_freeze(const union bpf_attr *attr)
1616 {
1617 	int err = 0, ufd = attr->map_fd;
1618 	struct bpf_map *map;
1619 	struct fd f;
1620 
1621 	if (CHECK_ATTR(BPF_MAP_FREEZE))
1622 		return -EINVAL;
1623 
1624 	f = fdget(ufd);
1625 	map = __bpf_map_get(f);
1626 	if (IS_ERR(map))
1627 		return PTR_ERR(map);
1628 
1629 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS ||
1630 	    map_value_has_timer(map)) {
1631 		fdput(f);
1632 		return -ENOTSUPP;
1633 	}
1634 
1635 	mutex_lock(&map->freeze_mutex);
1636 	if (bpf_map_write_active(map)) {
1637 		err = -EBUSY;
1638 		goto err_put;
1639 	}
1640 	if (READ_ONCE(map->frozen)) {
1641 		err = -EBUSY;
1642 		goto err_put;
1643 	}
1644 	if (!bpf_capable()) {
1645 		err = -EPERM;
1646 		goto err_put;
1647 	}
1648 
1649 	WRITE_ONCE(map->frozen, true);
1650 err_put:
1651 	mutex_unlock(&map->freeze_mutex);
1652 	fdput(f);
1653 	return err;
1654 }
1655 
1656 static const struct bpf_prog_ops * const bpf_prog_types[] = {
1657 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
1658 	[_id] = & _name ## _prog_ops,
1659 #define BPF_MAP_TYPE(_id, _ops)
1660 #define BPF_LINK_TYPE(_id, _name)
1661 #include <linux/bpf_types.h>
1662 #undef BPF_PROG_TYPE
1663 #undef BPF_MAP_TYPE
1664 #undef BPF_LINK_TYPE
1665 };
1666 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)1667 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
1668 {
1669 	const struct bpf_prog_ops *ops;
1670 
1671 	if (type >= ARRAY_SIZE(bpf_prog_types))
1672 		return -EINVAL;
1673 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
1674 	ops = bpf_prog_types[type];
1675 	if (!ops)
1676 		return -EINVAL;
1677 
1678 	if (!bpf_prog_is_dev_bound(prog->aux))
1679 		prog->aux->ops = ops;
1680 	else
1681 		prog->aux->ops = &bpf_offload_prog_ops;
1682 	prog->type = type;
1683 	return 0;
1684 }
1685 
1686 enum bpf_audit {
1687 	BPF_AUDIT_LOAD,
1688 	BPF_AUDIT_UNLOAD,
1689 	BPF_AUDIT_MAX,
1690 };
1691 
1692 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
1693 	[BPF_AUDIT_LOAD]   = "LOAD",
1694 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
1695 };
1696 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)1697 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
1698 {
1699 	struct audit_context *ctx = NULL;
1700 	struct audit_buffer *ab;
1701 
1702 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
1703 		return;
1704 	if (audit_enabled == AUDIT_OFF)
1705 		return;
1706 	if (!in_irq() && !irqs_disabled())
1707 		ctx = audit_context();
1708 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
1709 	if (unlikely(!ab))
1710 		return;
1711 	audit_log_format(ab, "prog-id=%u op=%s",
1712 			 prog->aux->id, bpf_audit_str[op]);
1713 	audit_log_end(ab);
1714 }
1715 
bpf_prog_alloc_id(struct bpf_prog * prog)1716 static int bpf_prog_alloc_id(struct bpf_prog *prog)
1717 {
1718 	int id;
1719 
1720 	idr_preload(GFP_KERNEL);
1721 	spin_lock_bh(&prog_idr_lock);
1722 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
1723 	if (id > 0)
1724 		prog->aux->id = id;
1725 	spin_unlock_bh(&prog_idr_lock);
1726 	idr_preload_end();
1727 
1728 	/* id is in [1, INT_MAX) */
1729 	if (WARN_ON_ONCE(!id))
1730 		return -ENOSPC;
1731 
1732 	return id > 0 ? 0 : id;
1733 }
1734 
bpf_prog_free_id(struct bpf_prog * prog,bool do_idr_lock)1735 void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
1736 {
1737 	unsigned long flags;
1738 
1739 	/* cBPF to eBPF migrations are currently not in the idr store.
1740 	 * Offloaded programs are removed from the store when their device
1741 	 * disappears - even if someone grabs an fd to them they are unusable,
1742 	 * simply waiting for refcnt to drop to be freed.
1743 	 */
1744 	if (!prog->aux->id)
1745 		return;
1746 
1747 	if (do_idr_lock)
1748 		spin_lock_irqsave(&prog_idr_lock, flags);
1749 	else
1750 		__acquire(&prog_idr_lock);
1751 
1752 	idr_remove(&prog_idr, prog->aux->id);
1753 	prog->aux->id = 0;
1754 
1755 	if (do_idr_lock)
1756 		spin_unlock_irqrestore(&prog_idr_lock, flags);
1757 	else
1758 		__release(&prog_idr_lock);
1759 }
1760 
__bpf_prog_put_rcu(struct rcu_head * rcu)1761 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
1762 {
1763 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
1764 
1765 	kvfree(aux->func_info);
1766 	kfree(aux->func_info_aux);
1767 	free_uid(aux->user);
1768 	security_bpf_prog_free(aux);
1769 	bpf_prog_free(aux->prog);
1770 }
1771 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)1772 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
1773 {
1774 	bpf_prog_kallsyms_del_all(prog);
1775 	btf_put(prog->aux->btf);
1776 	kvfree(prog->aux->jited_linfo);
1777 	kvfree(prog->aux->linfo);
1778 	kfree(prog->aux->kfunc_tab);
1779 	if (prog->aux->attach_btf)
1780 		btf_put(prog->aux->attach_btf);
1781 
1782 	if (deferred) {
1783 		if (prog->aux->sleepable)
1784 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
1785 		else
1786 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
1787 	} else {
1788 		__bpf_prog_put_rcu(&prog->aux->rcu);
1789 	}
1790 }
1791 
bpf_prog_put_deferred(struct work_struct * work)1792 static void bpf_prog_put_deferred(struct work_struct *work)
1793 {
1794 	struct bpf_prog_aux *aux;
1795 	struct bpf_prog *prog;
1796 
1797 	aux = container_of(work, struct bpf_prog_aux, work);
1798 	prog = aux->prog;
1799 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
1800 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
1801 	bpf_prog_free_id(prog, true);
1802 	__bpf_prog_put_noref(prog, true);
1803 }
1804 
__bpf_prog_put(struct bpf_prog * prog,bool do_idr_lock)1805 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
1806 {
1807 	struct bpf_prog_aux *aux = prog->aux;
1808 
1809 	if (atomic64_dec_and_test(&aux->refcnt)) {
1810 		if (in_irq() || irqs_disabled()) {
1811 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
1812 			schedule_work(&aux->work);
1813 		} else {
1814 			bpf_prog_put_deferred(&aux->work);
1815 		}
1816 	}
1817 }
1818 
bpf_prog_put(struct bpf_prog * prog)1819 void bpf_prog_put(struct bpf_prog *prog)
1820 {
1821 	__bpf_prog_put(prog, true);
1822 }
1823 EXPORT_SYMBOL_GPL(bpf_prog_put);
1824 
bpf_prog_release(struct inode * inode,struct file * filp)1825 static int bpf_prog_release(struct inode *inode, struct file *filp)
1826 {
1827 	struct bpf_prog *prog = filp->private_data;
1828 
1829 	bpf_prog_put(prog);
1830 	return 0;
1831 }
1832 
1833 struct bpf_prog_kstats {
1834 	u64 nsecs;
1835 	u64 cnt;
1836 	u64 misses;
1837 };
1838 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)1839 static void bpf_prog_get_stats(const struct bpf_prog *prog,
1840 			       struct bpf_prog_kstats *stats)
1841 {
1842 	u64 nsecs = 0, cnt = 0, misses = 0;
1843 	int cpu;
1844 
1845 	for_each_possible_cpu(cpu) {
1846 		const struct bpf_prog_stats *st;
1847 		unsigned int start;
1848 		u64 tnsecs, tcnt, tmisses;
1849 
1850 		st = per_cpu_ptr(prog->stats, cpu);
1851 		do {
1852 			start = u64_stats_fetch_begin_irq(&st->syncp);
1853 			tnsecs = u64_stats_read(&st->nsecs);
1854 			tcnt = u64_stats_read(&st->cnt);
1855 			tmisses = u64_stats_read(&st->misses);
1856 		} while (u64_stats_fetch_retry_irq(&st->syncp, start));
1857 		nsecs += tnsecs;
1858 		cnt += tcnt;
1859 		misses += tmisses;
1860 	}
1861 	stats->nsecs = nsecs;
1862 	stats->cnt = cnt;
1863 	stats->misses = misses;
1864 }
1865 
1866 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)1867 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
1868 {
1869 	const struct bpf_prog *prog = filp->private_data;
1870 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
1871 	struct bpf_prog_kstats stats;
1872 
1873 	bpf_prog_get_stats(prog, &stats);
1874 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
1875 	seq_printf(m,
1876 		   "prog_type:\t%u\n"
1877 		   "prog_jited:\t%u\n"
1878 		   "prog_tag:\t%s\n"
1879 		   "memlock:\t%llu\n"
1880 		   "prog_id:\t%u\n"
1881 		   "run_time_ns:\t%llu\n"
1882 		   "run_cnt:\t%llu\n"
1883 		   "recursion_misses:\t%llu\n",
1884 		   prog->type,
1885 		   prog->jited,
1886 		   prog_tag,
1887 		   prog->pages * 1ULL << PAGE_SHIFT,
1888 		   prog->aux->id,
1889 		   stats.nsecs,
1890 		   stats.cnt,
1891 		   stats.misses);
1892 }
1893 #endif
1894 
1895 const struct file_operations bpf_prog_fops = {
1896 #ifdef CONFIG_PROC_FS
1897 	.show_fdinfo	= bpf_prog_show_fdinfo,
1898 #endif
1899 	.release	= bpf_prog_release,
1900 	.read		= bpf_dummy_read,
1901 	.write		= bpf_dummy_write,
1902 };
1903 
bpf_prog_new_fd(struct bpf_prog * prog)1904 int bpf_prog_new_fd(struct bpf_prog *prog)
1905 {
1906 	int ret;
1907 
1908 	ret = security_bpf_prog(prog);
1909 	if (ret < 0)
1910 		return ret;
1911 
1912 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
1913 				O_RDWR | O_CLOEXEC);
1914 }
1915 
____bpf_prog_get(struct fd f)1916 static struct bpf_prog *____bpf_prog_get(struct fd f)
1917 {
1918 	if (!f.file)
1919 		return ERR_PTR(-EBADF);
1920 	if (f.file->f_op != &bpf_prog_fops) {
1921 		fdput(f);
1922 		return ERR_PTR(-EINVAL);
1923 	}
1924 
1925 	return f.file->private_data;
1926 }
1927 
bpf_prog_add(struct bpf_prog * prog,int i)1928 void bpf_prog_add(struct bpf_prog *prog, int i)
1929 {
1930 	atomic64_add(i, &prog->aux->refcnt);
1931 }
1932 EXPORT_SYMBOL_GPL(bpf_prog_add);
1933 
bpf_prog_sub(struct bpf_prog * prog,int i)1934 void bpf_prog_sub(struct bpf_prog *prog, int i)
1935 {
1936 	/* Only to be used for undoing previous bpf_prog_add() in some
1937 	 * error path. We still know that another entity in our call
1938 	 * path holds a reference to the program, thus atomic_sub() can
1939 	 * be safely used in such cases!
1940 	 */
1941 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
1942 }
1943 EXPORT_SYMBOL_GPL(bpf_prog_sub);
1944 
bpf_prog_inc(struct bpf_prog * prog)1945 void bpf_prog_inc(struct bpf_prog *prog)
1946 {
1947 	atomic64_inc(&prog->aux->refcnt);
1948 }
1949 EXPORT_SYMBOL_GPL(bpf_prog_inc);
1950 
1951 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)1952 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
1953 {
1954 	int refold;
1955 
1956 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
1957 
1958 	if (!refold)
1959 		return ERR_PTR(-ENOENT);
1960 
1961 	return prog;
1962 }
1963 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
1964 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)1965 bool bpf_prog_get_ok(struct bpf_prog *prog,
1966 			    enum bpf_prog_type *attach_type, bool attach_drv)
1967 {
1968 	/* not an attachment, just a refcount inc, always allow */
1969 	if (!attach_type)
1970 		return true;
1971 
1972 	if (prog->type != *attach_type)
1973 		return false;
1974 	if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
1975 		return false;
1976 
1977 	return true;
1978 }
1979 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)1980 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
1981 				       bool attach_drv)
1982 {
1983 	struct fd f = fdget(ufd);
1984 	struct bpf_prog *prog;
1985 
1986 	prog = ____bpf_prog_get(f);
1987 	if (IS_ERR(prog))
1988 		return prog;
1989 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
1990 		prog = ERR_PTR(-EINVAL);
1991 		goto out;
1992 	}
1993 
1994 	bpf_prog_inc(prog);
1995 out:
1996 	fdput(f);
1997 	return prog;
1998 }
1999 
bpf_prog_get(u32 ufd)2000 struct bpf_prog *bpf_prog_get(u32 ufd)
2001 {
2002 	return __bpf_prog_get(ufd, NULL, false);
2003 }
2004 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2005 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2006 				       bool attach_drv)
2007 {
2008 	return __bpf_prog_get(ufd, &type, attach_drv);
2009 }
2010 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2011 
2012 /* Initially all BPF programs could be loaded w/o specifying
2013  * expected_attach_type. Later for some of them specifying expected_attach_type
2014  * at load time became required so that program could be validated properly.
2015  * Programs of types that are allowed to be loaded both w/ and w/o (for
2016  * backward compatibility) expected_attach_type, should have the default attach
2017  * type assigned to expected_attach_type for the latter case, so that it can be
2018  * validated later at attach time.
2019  *
2020  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2021  * prog type requires it but has some attach types that have to be backward
2022  * compatible.
2023  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2024 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2025 {
2026 	switch (attr->prog_type) {
2027 	case BPF_PROG_TYPE_CGROUP_SOCK:
2028 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2029 		 * exist so checking for non-zero is the way to go here.
2030 		 */
2031 		if (!attr->expected_attach_type)
2032 			attr->expected_attach_type =
2033 				BPF_CGROUP_INET_SOCK_CREATE;
2034 		break;
2035 	case BPF_PROG_TYPE_SK_REUSEPORT:
2036 		if (!attr->expected_attach_type)
2037 			attr->expected_attach_type =
2038 				BPF_SK_REUSEPORT_SELECT;
2039 		break;
2040 	}
2041 }
2042 
2043 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)2044 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2045 			   enum bpf_attach_type expected_attach_type,
2046 			   struct btf *attach_btf, u32 btf_id,
2047 			   struct bpf_prog *dst_prog)
2048 {
2049 	if (btf_id) {
2050 		if (btf_id > BTF_MAX_TYPE)
2051 			return -EINVAL;
2052 
2053 		if (!attach_btf && !dst_prog)
2054 			return -EINVAL;
2055 
2056 		switch (prog_type) {
2057 		case BPF_PROG_TYPE_TRACING:
2058 		case BPF_PROG_TYPE_LSM:
2059 		case BPF_PROG_TYPE_STRUCT_OPS:
2060 		case BPF_PROG_TYPE_EXT:
2061 			break;
2062 		default:
2063 			return -EINVAL;
2064 		}
2065 	}
2066 
2067 	if (attach_btf && (!btf_id || dst_prog))
2068 		return -EINVAL;
2069 
2070 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2071 	    prog_type != BPF_PROG_TYPE_EXT)
2072 		return -EINVAL;
2073 
2074 	switch (prog_type) {
2075 	case BPF_PROG_TYPE_CGROUP_SOCK:
2076 		switch (expected_attach_type) {
2077 		case BPF_CGROUP_INET_SOCK_CREATE:
2078 		case BPF_CGROUP_INET_SOCK_RELEASE:
2079 		case BPF_CGROUP_INET4_POST_BIND:
2080 		case BPF_CGROUP_INET6_POST_BIND:
2081 			return 0;
2082 		default:
2083 			return -EINVAL;
2084 		}
2085 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2086 		switch (expected_attach_type) {
2087 		case BPF_CGROUP_INET4_BIND:
2088 		case BPF_CGROUP_INET6_BIND:
2089 		case BPF_CGROUP_INET4_CONNECT:
2090 		case BPF_CGROUP_INET6_CONNECT:
2091 		case BPF_CGROUP_INET4_GETPEERNAME:
2092 		case BPF_CGROUP_INET6_GETPEERNAME:
2093 		case BPF_CGROUP_INET4_GETSOCKNAME:
2094 		case BPF_CGROUP_INET6_GETSOCKNAME:
2095 		case BPF_CGROUP_UDP4_SENDMSG:
2096 		case BPF_CGROUP_UDP6_SENDMSG:
2097 		case BPF_CGROUP_UDP4_RECVMSG:
2098 		case BPF_CGROUP_UDP6_RECVMSG:
2099 			return 0;
2100 		default:
2101 			return -EINVAL;
2102 		}
2103 	case BPF_PROG_TYPE_CGROUP_SKB:
2104 		switch (expected_attach_type) {
2105 		case BPF_CGROUP_INET_INGRESS:
2106 		case BPF_CGROUP_INET_EGRESS:
2107 			return 0;
2108 		default:
2109 			return -EINVAL;
2110 		}
2111 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2112 		switch (expected_attach_type) {
2113 		case BPF_CGROUP_SETSOCKOPT:
2114 		case BPF_CGROUP_GETSOCKOPT:
2115 			return 0;
2116 		default:
2117 			return -EINVAL;
2118 		}
2119 	case BPF_PROG_TYPE_SK_LOOKUP:
2120 		if (expected_attach_type == BPF_SK_LOOKUP)
2121 			return 0;
2122 		return -EINVAL;
2123 	case BPF_PROG_TYPE_SK_REUSEPORT:
2124 		switch (expected_attach_type) {
2125 		case BPF_SK_REUSEPORT_SELECT:
2126 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2127 			return 0;
2128 		default:
2129 			return -EINVAL;
2130 		}
2131 	case BPF_PROG_TYPE_SYSCALL:
2132 	case BPF_PROG_TYPE_EXT:
2133 		if (expected_attach_type)
2134 			return -EINVAL;
2135 		fallthrough;
2136 	default:
2137 		return 0;
2138 	}
2139 }
2140 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2141 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2142 {
2143 	switch (prog_type) {
2144 	case BPF_PROG_TYPE_SCHED_CLS:
2145 	case BPF_PROG_TYPE_SCHED_ACT:
2146 	case BPF_PROG_TYPE_XDP:
2147 	case BPF_PROG_TYPE_LWT_IN:
2148 	case BPF_PROG_TYPE_LWT_OUT:
2149 	case BPF_PROG_TYPE_LWT_XMIT:
2150 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2151 	case BPF_PROG_TYPE_SK_SKB:
2152 	case BPF_PROG_TYPE_SK_MSG:
2153 	case BPF_PROG_TYPE_LIRC_MODE2:
2154 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2155 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2156 	case BPF_PROG_TYPE_CGROUP_SOCK:
2157 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2158 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2159 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2160 	case BPF_PROG_TYPE_SOCK_OPS:
2161 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2162 		return true;
2163 	case BPF_PROG_TYPE_CGROUP_SKB:
2164 		/* always unpriv */
2165 	case BPF_PROG_TYPE_SK_REUSEPORT:
2166 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2167 	default:
2168 		return false;
2169 	}
2170 }
2171 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2172 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2173 {
2174 	switch (prog_type) {
2175 	case BPF_PROG_TYPE_KPROBE:
2176 	case BPF_PROG_TYPE_TRACEPOINT:
2177 	case BPF_PROG_TYPE_PERF_EVENT:
2178 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2179 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2180 	case BPF_PROG_TYPE_TRACING:
2181 	case BPF_PROG_TYPE_LSM:
2182 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2183 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2184 		return true;
2185 	default:
2186 		return false;
2187 	}
2188 }
2189 
2190 /* last field in 'union bpf_attr' used by this command */
2191 #define	BPF_PROG_LOAD_LAST_FIELD fd_array
2192 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr)2193 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
2194 {
2195 	enum bpf_prog_type type = attr->prog_type;
2196 	struct bpf_prog *prog, *dst_prog = NULL;
2197 	struct btf *attach_btf = NULL;
2198 	int err;
2199 	char license[128];
2200 	bool is_gpl;
2201 
2202 	if (CHECK_ATTR(BPF_PROG_LOAD))
2203 		return -EINVAL;
2204 
2205 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2206 				 BPF_F_ANY_ALIGNMENT |
2207 				 BPF_F_TEST_STATE_FREQ |
2208 				 BPF_F_SLEEPABLE |
2209 				 BPF_F_TEST_RND_HI32))
2210 		return -EINVAL;
2211 
2212 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2213 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2214 	    !bpf_capable())
2215 		return -EPERM;
2216 
2217 	/* copy eBPF program license from user space */
2218 	if (strncpy_from_bpfptr(license,
2219 				make_bpfptr(attr->license, uattr.is_kernel),
2220 				sizeof(license) - 1) < 0)
2221 		return -EFAULT;
2222 	license[sizeof(license) - 1] = 0;
2223 
2224 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
2225 	is_gpl = license_is_gpl_compatible(license);
2226 
2227 	if (attr->insn_cnt == 0 ||
2228 	    attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
2229 		return -E2BIG;
2230 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2231 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2232 	    !bpf_capable())
2233 		return -EPERM;
2234 
2235 	if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
2236 		return -EPERM;
2237 	if (is_perfmon_prog_type(type) && !perfmon_capable())
2238 		return -EPERM;
2239 
2240 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2241 	 * or btf, we need to check which one it is
2242 	 */
2243 	if (attr->attach_prog_fd) {
2244 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2245 		if (IS_ERR(dst_prog)) {
2246 			dst_prog = NULL;
2247 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2248 			if (IS_ERR(attach_btf))
2249 				return -EINVAL;
2250 			if (!btf_is_kernel(attach_btf)) {
2251 				/* attaching through specifying bpf_prog's BTF
2252 				 * objects directly might be supported eventually
2253 				 */
2254 				btf_put(attach_btf);
2255 				return -ENOTSUPP;
2256 			}
2257 		}
2258 	} else if (attr->attach_btf_id) {
2259 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2260 		attach_btf = bpf_get_btf_vmlinux();
2261 		if (IS_ERR(attach_btf))
2262 			return PTR_ERR(attach_btf);
2263 		if (!attach_btf)
2264 			return -EINVAL;
2265 		btf_get(attach_btf);
2266 	}
2267 
2268 	bpf_prog_load_fixup_attach_type(attr);
2269 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2270 				       attach_btf, attr->attach_btf_id,
2271 				       dst_prog)) {
2272 		if (dst_prog)
2273 			bpf_prog_put(dst_prog);
2274 		if (attach_btf)
2275 			btf_put(attach_btf);
2276 		return -EINVAL;
2277 	}
2278 
2279 	/* plain bpf_prog allocation */
2280 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2281 	if (!prog) {
2282 		if (dst_prog)
2283 			bpf_prog_put(dst_prog);
2284 		if (attach_btf)
2285 			btf_put(attach_btf);
2286 		return -ENOMEM;
2287 	}
2288 
2289 	prog->expected_attach_type = attr->expected_attach_type;
2290 	prog->aux->attach_btf = attach_btf;
2291 	prog->aux->attach_btf_id = attr->attach_btf_id;
2292 	prog->aux->dst_prog = dst_prog;
2293 	prog->aux->offload_requested = !!attr->prog_ifindex;
2294 	prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE;
2295 
2296 	err = security_bpf_prog_alloc(prog->aux);
2297 	if (err)
2298 		goto free_prog;
2299 
2300 	prog->aux->user = get_current_user();
2301 	prog->len = attr->insn_cnt;
2302 
2303 	err = -EFAULT;
2304 	if (copy_from_bpfptr(prog->insns,
2305 			     make_bpfptr(attr->insns, uattr.is_kernel),
2306 			     bpf_prog_insn_size(prog)) != 0)
2307 		goto free_prog_sec;
2308 
2309 	prog->orig_prog = NULL;
2310 	prog->jited = 0;
2311 
2312 	atomic64_set(&prog->aux->refcnt, 1);
2313 	prog->gpl_compatible = is_gpl ? 1 : 0;
2314 
2315 	if (bpf_prog_is_dev_bound(prog->aux)) {
2316 		err = bpf_prog_offload_init(prog, attr);
2317 		if (err)
2318 			goto free_prog_sec;
2319 	}
2320 
2321 	/* find program type: socket_filter vs tracing_filter */
2322 	err = find_prog_type(type, prog);
2323 	if (err < 0)
2324 		goto free_prog_sec;
2325 
2326 	prog->aux->load_time = ktime_get_boottime_ns();
2327 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2328 			       sizeof(attr->prog_name));
2329 	if (err < 0)
2330 		goto free_prog_sec;
2331 
2332 	/* run eBPF verifier */
2333 	err = bpf_check(&prog, attr, uattr);
2334 	if (err < 0)
2335 		goto free_used_maps;
2336 
2337 	prog = bpf_prog_select_runtime(prog, &err);
2338 	if (err < 0)
2339 		goto free_used_maps;
2340 
2341 	err = bpf_prog_alloc_id(prog);
2342 	if (err)
2343 		goto free_used_maps;
2344 
2345 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
2346 	 * effectively publicly exposed. However, retrieving via
2347 	 * bpf_prog_get_fd_by_id() will take another reference,
2348 	 * therefore it cannot be gone underneath us.
2349 	 *
2350 	 * Only for the time /after/ successful bpf_prog_new_fd()
2351 	 * and before returning to userspace, we might just hold
2352 	 * one reference and any parallel close on that fd could
2353 	 * rip everything out. Hence, below notifications must
2354 	 * happen before bpf_prog_new_fd().
2355 	 *
2356 	 * Also, any failure handling from this point onwards must
2357 	 * be using bpf_prog_put() given the program is exposed.
2358 	 */
2359 	bpf_prog_kallsyms_add(prog);
2360 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2361 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
2362 
2363 	err = bpf_prog_new_fd(prog);
2364 	if (err < 0)
2365 		bpf_prog_put(prog);
2366 	return err;
2367 
2368 free_used_maps:
2369 	/* In case we have subprogs, we need to wait for a grace
2370 	 * period before we can tear down JIT memory since symbols
2371 	 * are already exposed under kallsyms.
2372 	 */
2373 	__bpf_prog_put_noref(prog, prog->aux->func_cnt);
2374 	return err;
2375 free_prog_sec:
2376 	free_uid(prog->aux->user);
2377 	security_bpf_prog_free(prog->aux);
2378 free_prog:
2379 	if (prog->aux->attach_btf)
2380 		btf_put(prog->aux->attach_btf);
2381 	bpf_prog_free(prog);
2382 	return err;
2383 }
2384 
2385 #define BPF_OBJ_LAST_FIELD file_flags
2386 
bpf_obj_pin(const union bpf_attr * attr)2387 static int bpf_obj_pin(const union bpf_attr *attr)
2388 {
2389 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
2390 		return -EINVAL;
2391 
2392 	return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
2393 }
2394 
bpf_obj_get(const union bpf_attr * attr)2395 static int bpf_obj_get(const union bpf_attr *attr)
2396 {
2397 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
2398 	    attr->file_flags & ~BPF_OBJ_FLAG_MASK)
2399 		return -EINVAL;
2400 
2401 	return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
2402 				attr->file_flags);
2403 }
2404 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)2405 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
2406 		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
2407 {
2408 	atomic64_set(&link->refcnt, 1);
2409 	link->type = type;
2410 	link->id = 0;
2411 	link->ops = ops;
2412 	link->prog = prog;
2413 }
2414 
bpf_link_free_id(int id)2415 static void bpf_link_free_id(int id)
2416 {
2417 	if (!id)
2418 		return;
2419 
2420 	spin_lock_bh(&link_idr_lock);
2421 	idr_remove(&link_idr, id);
2422 	spin_unlock_bh(&link_idr_lock);
2423 }
2424 
2425 /* Clean up bpf_link and corresponding anon_inode file and FD. After
2426  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
2427  * anon_inode's release() call. This helper marksbpf_link as
2428  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
2429  * is not decremented, it's the responsibility of a calling code that failed
2430  * to complete bpf_link initialization.
2431  */
bpf_link_cleanup(struct bpf_link_primer * primer)2432 void bpf_link_cleanup(struct bpf_link_primer *primer)
2433 {
2434 	primer->link->prog = NULL;
2435 	bpf_link_free_id(primer->id);
2436 	fput(primer->file);
2437 	put_unused_fd(primer->fd);
2438 }
2439 
bpf_link_inc(struct bpf_link * link)2440 void bpf_link_inc(struct bpf_link *link)
2441 {
2442 	atomic64_inc(&link->refcnt);
2443 }
2444 
2445 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)2446 static void bpf_link_free(struct bpf_link *link)
2447 {
2448 	bpf_link_free_id(link->id);
2449 	if (link->prog) {
2450 		/* detach BPF program, clean up used resources */
2451 		link->ops->release(link);
2452 		bpf_prog_put(link->prog);
2453 	}
2454 	/* free bpf_link and its containing memory */
2455 	link->ops->dealloc(link);
2456 }
2457 
bpf_link_put_deferred(struct work_struct * work)2458 static void bpf_link_put_deferred(struct work_struct *work)
2459 {
2460 	struct bpf_link *link = container_of(work, struct bpf_link, work);
2461 
2462 	bpf_link_free(link);
2463 }
2464 
2465 /* bpf_link_put can be called from atomic context, but ensures that resources
2466  * are freed from process context
2467  */
bpf_link_put(struct bpf_link * link)2468 void bpf_link_put(struct bpf_link *link)
2469 {
2470 	if (!atomic64_dec_and_test(&link->refcnt))
2471 		return;
2472 
2473 	if (in_atomic()) {
2474 		INIT_WORK(&link->work, bpf_link_put_deferred);
2475 		schedule_work(&link->work);
2476 	} else {
2477 		bpf_link_free(link);
2478 	}
2479 }
2480 
bpf_link_release(struct inode * inode,struct file * filp)2481 static int bpf_link_release(struct inode *inode, struct file *filp)
2482 {
2483 	struct bpf_link *link = filp->private_data;
2484 
2485 	bpf_link_put(link);
2486 	return 0;
2487 }
2488 
2489 #ifdef CONFIG_PROC_FS
2490 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
2491 #define BPF_MAP_TYPE(_id, _ops)
2492 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
2493 static const char *bpf_link_type_strs[] = {
2494 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
2495 #include <linux/bpf_types.h>
2496 };
2497 #undef BPF_PROG_TYPE
2498 #undef BPF_MAP_TYPE
2499 #undef BPF_LINK_TYPE
2500 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)2501 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
2502 {
2503 	const struct bpf_link *link = filp->private_data;
2504 	const struct bpf_prog *prog = link->prog;
2505 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2506 
2507 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2508 	seq_printf(m,
2509 		   "link_type:\t%s\n"
2510 		   "link_id:\t%u\n"
2511 		   "prog_tag:\t%s\n"
2512 		   "prog_id:\t%u\n",
2513 		   bpf_link_type_strs[link->type],
2514 		   link->id,
2515 		   prog_tag,
2516 		   prog->aux->id);
2517 	if (link->ops->show_fdinfo)
2518 		link->ops->show_fdinfo(link, m);
2519 }
2520 #endif
2521 
2522 static const struct file_operations bpf_link_fops = {
2523 #ifdef CONFIG_PROC_FS
2524 	.show_fdinfo	= bpf_link_show_fdinfo,
2525 #endif
2526 	.release	= bpf_link_release,
2527 	.read		= bpf_dummy_read,
2528 	.write		= bpf_dummy_write,
2529 };
2530 
bpf_link_alloc_id(struct bpf_link * link)2531 static int bpf_link_alloc_id(struct bpf_link *link)
2532 {
2533 	int id;
2534 
2535 	idr_preload(GFP_KERNEL);
2536 	spin_lock_bh(&link_idr_lock);
2537 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
2538 	spin_unlock_bh(&link_idr_lock);
2539 	idr_preload_end();
2540 
2541 	return id;
2542 }
2543 
2544 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
2545  * reserving unused FD and allocating ID from link_idr. This is to be paired
2546  * with bpf_link_settle() to install FD and ID and expose bpf_link to
2547  * user-space, if bpf_link is successfully attached. If not, bpf_link and
2548  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
2549  * transient state is passed around in struct bpf_link_primer.
2550  * This is preferred way to create and initialize bpf_link, especially when
2551  * there are complicated and expensive operations inbetween creating bpf_link
2552  * itself and attaching it to BPF hook. By using bpf_link_prime() and
2553  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
2554  * expensive (and potentially failing) roll back operations in a rare case
2555  * that file, FD, or ID can't be allocated.
2556  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)2557 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
2558 {
2559 	struct file *file;
2560 	int fd, id;
2561 
2562 	fd = get_unused_fd_flags(O_CLOEXEC);
2563 	if (fd < 0)
2564 		return fd;
2565 
2566 
2567 	id = bpf_link_alloc_id(link);
2568 	if (id < 0) {
2569 		put_unused_fd(fd);
2570 		return id;
2571 	}
2572 
2573 	file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
2574 	if (IS_ERR(file)) {
2575 		bpf_link_free_id(id);
2576 		put_unused_fd(fd);
2577 		return PTR_ERR(file);
2578 	}
2579 
2580 	primer->link = link;
2581 	primer->file = file;
2582 	primer->fd = fd;
2583 	primer->id = id;
2584 	return 0;
2585 }
2586 
bpf_link_settle(struct bpf_link_primer * primer)2587 int bpf_link_settle(struct bpf_link_primer *primer)
2588 {
2589 	/* make bpf_link fetchable by ID */
2590 	spin_lock_bh(&link_idr_lock);
2591 	primer->link->id = primer->id;
2592 	spin_unlock_bh(&link_idr_lock);
2593 	/* make bpf_link fetchable by FD */
2594 	fd_install(primer->fd, primer->file);
2595 	/* pass through installed FD */
2596 	return primer->fd;
2597 }
2598 
bpf_link_new_fd(struct bpf_link * link)2599 int bpf_link_new_fd(struct bpf_link *link)
2600 {
2601 	return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
2602 }
2603 
bpf_link_get_from_fd(u32 ufd)2604 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
2605 {
2606 	struct fd f = fdget(ufd);
2607 	struct bpf_link *link;
2608 
2609 	if (!f.file)
2610 		return ERR_PTR(-EBADF);
2611 	if (f.file->f_op != &bpf_link_fops) {
2612 		fdput(f);
2613 		return ERR_PTR(-EINVAL);
2614 	}
2615 
2616 	link = f.file->private_data;
2617 	bpf_link_inc(link);
2618 	fdput(f);
2619 
2620 	return link;
2621 }
2622 
2623 struct bpf_tracing_link {
2624 	struct bpf_link link;
2625 	enum bpf_attach_type attach_type;
2626 	struct bpf_trampoline *trampoline;
2627 	struct bpf_prog *tgt_prog;
2628 };
2629 
bpf_tracing_link_release(struct bpf_link * link)2630 static void bpf_tracing_link_release(struct bpf_link *link)
2631 {
2632 	struct bpf_tracing_link *tr_link =
2633 		container_of(link, struct bpf_tracing_link, link);
2634 
2635 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(link->prog,
2636 						tr_link->trampoline));
2637 
2638 	bpf_trampoline_put(tr_link->trampoline);
2639 
2640 	/* tgt_prog is NULL if target is a kernel function */
2641 	if (tr_link->tgt_prog)
2642 		bpf_prog_put(tr_link->tgt_prog);
2643 }
2644 
bpf_tracing_link_dealloc(struct bpf_link * link)2645 static void bpf_tracing_link_dealloc(struct bpf_link *link)
2646 {
2647 	struct bpf_tracing_link *tr_link =
2648 		container_of(link, struct bpf_tracing_link, link);
2649 
2650 	kfree(tr_link);
2651 }
2652 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)2653 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
2654 					 struct seq_file *seq)
2655 {
2656 	struct bpf_tracing_link *tr_link =
2657 		container_of(link, struct bpf_tracing_link, link);
2658 
2659 	seq_printf(seq,
2660 		   "attach_type:\t%d\n",
2661 		   tr_link->attach_type);
2662 }
2663 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2664 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
2665 					   struct bpf_link_info *info)
2666 {
2667 	struct bpf_tracing_link *tr_link =
2668 		container_of(link, struct bpf_tracing_link, link);
2669 
2670 	info->tracing.attach_type = tr_link->attach_type;
2671 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
2672 				  &info->tracing.target_obj_id,
2673 				  &info->tracing.target_btf_id);
2674 
2675 	return 0;
2676 }
2677 
2678 static const struct bpf_link_ops bpf_tracing_link_lops = {
2679 	.release = bpf_tracing_link_release,
2680 	.dealloc = bpf_tracing_link_dealloc,
2681 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
2682 	.fill_link_info = bpf_tracing_link_fill_link_info,
2683 };
2684 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id)2685 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
2686 				   int tgt_prog_fd,
2687 				   u32 btf_id)
2688 {
2689 	struct bpf_link_primer link_primer;
2690 	struct bpf_prog *tgt_prog = NULL;
2691 	struct bpf_trampoline *tr = NULL;
2692 	struct bpf_tracing_link *link;
2693 	u64 key = 0;
2694 	int err;
2695 
2696 	switch (prog->type) {
2697 	case BPF_PROG_TYPE_TRACING:
2698 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
2699 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
2700 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
2701 			err = -EINVAL;
2702 			goto out_put_prog;
2703 		}
2704 		break;
2705 	case BPF_PROG_TYPE_EXT:
2706 		if (prog->expected_attach_type != 0) {
2707 			err = -EINVAL;
2708 			goto out_put_prog;
2709 		}
2710 		break;
2711 	case BPF_PROG_TYPE_LSM:
2712 		if (prog->expected_attach_type != BPF_LSM_MAC) {
2713 			err = -EINVAL;
2714 			goto out_put_prog;
2715 		}
2716 		break;
2717 	default:
2718 		err = -EINVAL;
2719 		goto out_put_prog;
2720 	}
2721 
2722 	if (!!tgt_prog_fd != !!btf_id) {
2723 		err = -EINVAL;
2724 		goto out_put_prog;
2725 	}
2726 
2727 	if (tgt_prog_fd) {
2728 		/* For now we only allow new targets for BPF_PROG_TYPE_EXT */
2729 		if (prog->type != BPF_PROG_TYPE_EXT) {
2730 			err = -EINVAL;
2731 			goto out_put_prog;
2732 		}
2733 
2734 		tgt_prog = bpf_prog_get(tgt_prog_fd);
2735 		if (IS_ERR(tgt_prog)) {
2736 			err = PTR_ERR(tgt_prog);
2737 			tgt_prog = NULL;
2738 			goto out_put_prog;
2739 		}
2740 
2741 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
2742 	}
2743 
2744 	link = kzalloc(sizeof(*link), GFP_USER);
2745 	if (!link) {
2746 		err = -ENOMEM;
2747 		goto out_put_prog;
2748 	}
2749 	bpf_link_init(&link->link, BPF_LINK_TYPE_TRACING,
2750 		      &bpf_tracing_link_lops, prog);
2751 	link->attach_type = prog->expected_attach_type;
2752 
2753 	mutex_lock(&prog->aux->dst_mutex);
2754 
2755 	/* There are a few possible cases here:
2756 	 *
2757 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
2758 	 *   and not yet attached to anything, so we can use the values stored
2759 	 *   in prog->aux
2760 	 *
2761 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
2762          *   attached to a target and its initial target was cleared (below)
2763 	 *
2764 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
2765 	 *   target_btf_id using the link_create API.
2766 	 *
2767 	 * - if tgt_prog == NULL when this function was called using the old
2768 	 *   raw_tracepoint_open API, and we need a target from prog->aux
2769 	 *
2770 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
2771 	 *   was detached and is going for re-attachment.
2772 	 *
2773 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
2774 	 *   are NULL, then program was already attached and user did not provide
2775 	 *   tgt_prog_fd so we have no way to find out or create trampoline
2776 	 */
2777 	if (!prog->aux->dst_trampoline && !tgt_prog) {
2778 		/*
2779 		 * Allow re-attach for TRACING and LSM programs. If it's
2780 		 * currently linked, bpf_trampoline_link_prog will fail.
2781 		 * EXT programs need to specify tgt_prog_fd, so they
2782 		 * re-attach in separate code path.
2783 		 */
2784 		if (prog->type != BPF_PROG_TYPE_TRACING &&
2785 		    prog->type != BPF_PROG_TYPE_LSM) {
2786 			err = -EINVAL;
2787 			goto out_unlock;
2788 		}
2789 		/* We can allow re-attach only if we have valid attach_btf. */
2790 		if (!prog->aux->attach_btf) {
2791 			err = -EINVAL;
2792 			goto out_unlock;
2793 		}
2794 		btf_id = prog->aux->attach_btf_id;
2795 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
2796 	}
2797 
2798 	if (!prog->aux->dst_trampoline ||
2799 	    (key && key != prog->aux->dst_trampoline->key)) {
2800 		/* If there is no saved target, or the specified target is
2801 		 * different from the destination specified at load time, we
2802 		 * need a new trampoline and a check for compatibility
2803 		 */
2804 		struct bpf_attach_target_info tgt_info = {};
2805 
2806 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
2807 					      &tgt_info);
2808 		if (err)
2809 			goto out_unlock;
2810 
2811 		tr = bpf_trampoline_get(key, &tgt_info);
2812 		if (!tr) {
2813 			err = -ENOMEM;
2814 			goto out_unlock;
2815 		}
2816 	} else {
2817 		/* The caller didn't specify a target, or the target was the
2818 		 * same as the destination supplied during program load. This
2819 		 * means we can reuse the trampoline and reference from program
2820 		 * load time, and there is no need to allocate a new one. This
2821 		 * can only happen once for any program, as the saved values in
2822 		 * prog->aux are cleared below.
2823 		 */
2824 		tr = prog->aux->dst_trampoline;
2825 		tgt_prog = prog->aux->dst_prog;
2826 	}
2827 
2828 	err = bpf_link_prime(&link->link, &link_primer);
2829 	if (err)
2830 		goto out_unlock;
2831 
2832 	err = bpf_trampoline_link_prog(prog, tr);
2833 	if (err) {
2834 		bpf_link_cleanup(&link_primer);
2835 		link = NULL;
2836 		goto out_unlock;
2837 	}
2838 
2839 	link->tgt_prog = tgt_prog;
2840 	link->trampoline = tr;
2841 
2842 	/* Always clear the trampoline and target prog from prog->aux to make
2843 	 * sure the original attach destination is not kept alive after a
2844 	 * program is (re-)attached to another target.
2845 	 */
2846 	if (prog->aux->dst_prog &&
2847 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
2848 		/* got extra prog ref from syscall, or attaching to different prog */
2849 		bpf_prog_put(prog->aux->dst_prog);
2850 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
2851 		/* we allocated a new trampoline, so free the old one */
2852 		bpf_trampoline_put(prog->aux->dst_trampoline);
2853 
2854 	prog->aux->dst_prog = NULL;
2855 	prog->aux->dst_trampoline = NULL;
2856 	mutex_unlock(&prog->aux->dst_mutex);
2857 
2858 	return bpf_link_settle(&link_primer);
2859 out_unlock:
2860 	if (tr && tr != prog->aux->dst_trampoline)
2861 		bpf_trampoline_put(tr);
2862 	mutex_unlock(&prog->aux->dst_mutex);
2863 	kfree(link);
2864 out_put_prog:
2865 	if (tgt_prog_fd && tgt_prog)
2866 		bpf_prog_put(tgt_prog);
2867 	return err;
2868 }
2869 
2870 struct bpf_raw_tp_link {
2871 	struct bpf_link link;
2872 	struct bpf_raw_event_map *btp;
2873 };
2874 
bpf_raw_tp_link_release(struct bpf_link * link)2875 static void bpf_raw_tp_link_release(struct bpf_link *link)
2876 {
2877 	struct bpf_raw_tp_link *raw_tp =
2878 		container_of(link, struct bpf_raw_tp_link, link);
2879 
2880 	bpf_probe_unregister(raw_tp->btp, raw_tp->link.prog);
2881 	bpf_put_raw_tracepoint(raw_tp->btp);
2882 }
2883 
bpf_raw_tp_link_dealloc(struct bpf_link * link)2884 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
2885 {
2886 	struct bpf_raw_tp_link *raw_tp =
2887 		container_of(link, struct bpf_raw_tp_link, link);
2888 
2889 	kfree(raw_tp);
2890 }
2891 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)2892 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
2893 					struct seq_file *seq)
2894 {
2895 	struct bpf_raw_tp_link *raw_tp_link =
2896 		container_of(link, struct bpf_raw_tp_link, link);
2897 
2898 	seq_printf(seq,
2899 		   "tp_name:\t%s\n",
2900 		   raw_tp_link->btp->tp->name);
2901 }
2902 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)2903 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
2904 					  struct bpf_link_info *info)
2905 {
2906 	struct bpf_raw_tp_link *raw_tp_link =
2907 		container_of(link, struct bpf_raw_tp_link, link);
2908 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
2909 	const char *tp_name = raw_tp_link->btp->tp->name;
2910 	u32 ulen = info->raw_tracepoint.tp_name_len;
2911 	size_t tp_len = strlen(tp_name);
2912 
2913 	if (!ulen ^ !ubuf)
2914 		return -EINVAL;
2915 
2916 	info->raw_tracepoint.tp_name_len = tp_len + 1;
2917 
2918 	if (!ubuf)
2919 		return 0;
2920 
2921 	if (ulen >= tp_len + 1) {
2922 		if (copy_to_user(ubuf, tp_name, tp_len + 1))
2923 			return -EFAULT;
2924 	} else {
2925 		char zero = '\0';
2926 
2927 		if (copy_to_user(ubuf, tp_name, ulen - 1))
2928 			return -EFAULT;
2929 		if (put_user(zero, ubuf + ulen - 1))
2930 			return -EFAULT;
2931 		return -ENOSPC;
2932 	}
2933 
2934 	return 0;
2935 }
2936 
2937 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
2938 	.release = bpf_raw_tp_link_release,
2939 	.dealloc = bpf_raw_tp_link_dealloc,
2940 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
2941 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
2942 };
2943 
2944 #ifdef CONFIG_PERF_EVENTS
2945 struct bpf_perf_link {
2946 	struct bpf_link link;
2947 	struct file *perf_file;
2948 };
2949 
bpf_perf_link_release(struct bpf_link * link)2950 static void bpf_perf_link_release(struct bpf_link *link)
2951 {
2952 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
2953 	struct perf_event *event = perf_link->perf_file->private_data;
2954 
2955 	perf_event_free_bpf_prog(event);
2956 	fput(perf_link->perf_file);
2957 }
2958 
bpf_perf_link_dealloc(struct bpf_link * link)2959 static void bpf_perf_link_dealloc(struct bpf_link *link)
2960 {
2961 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
2962 
2963 	kfree(perf_link);
2964 }
2965 
2966 static const struct bpf_link_ops bpf_perf_link_lops = {
2967 	.release = bpf_perf_link_release,
2968 	.dealloc = bpf_perf_link_dealloc,
2969 };
2970 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)2971 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
2972 {
2973 	struct bpf_link_primer link_primer;
2974 	struct bpf_perf_link *link;
2975 	struct perf_event *event;
2976 	struct file *perf_file;
2977 	int err;
2978 
2979 	if (attr->link_create.flags)
2980 		return -EINVAL;
2981 
2982 	perf_file = perf_event_get(attr->link_create.target_fd);
2983 	if (IS_ERR(perf_file))
2984 		return PTR_ERR(perf_file);
2985 
2986 	link = kzalloc(sizeof(*link), GFP_USER);
2987 	if (!link) {
2988 		err = -ENOMEM;
2989 		goto out_put_file;
2990 	}
2991 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
2992 	link->perf_file = perf_file;
2993 
2994 	err = bpf_link_prime(&link->link, &link_primer);
2995 	if (err) {
2996 		kfree(link);
2997 		goto out_put_file;
2998 	}
2999 
3000 	event = perf_file->private_data;
3001 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3002 	if (err) {
3003 		bpf_link_cleanup(&link_primer);
3004 		goto out_put_file;
3005 	}
3006 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3007 	bpf_prog_inc(prog);
3008 
3009 	return bpf_link_settle(&link_primer);
3010 
3011 out_put_file:
3012 	fput(perf_file);
3013 	return err;
3014 }
3015 #endif /* CONFIG_PERF_EVENTS */
3016 
3017 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
3018 
bpf_raw_tracepoint_open(const union bpf_attr * attr)3019 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
3020 {
3021 	struct bpf_link_primer link_primer;
3022 	struct bpf_raw_tp_link *link;
3023 	struct bpf_raw_event_map *btp;
3024 	struct bpf_prog *prog;
3025 	const char *tp_name;
3026 	char buf[128];
3027 	int err;
3028 
3029 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
3030 		return -EINVAL;
3031 
3032 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
3033 	if (IS_ERR(prog))
3034 		return PTR_ERR(prog);
3035 
3036 	switch (prog->type) {
3037 	case BPF_PROG_TYPE_TRACING:
3038 	case BPF_PROG_TYPE_EXT:
3039 	case BPF_PROG_TYPE_LSM:
3040 		if (attr->raw_tracepoint.name) {
3041 			/* The attach point for this category of programs
3042 			 * should be specified via btf_id during program load.
3043 			 */
3044 			err = -EINVAL;
3045 			goto out_put_prog;
3046 		}
3047 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3048 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3049 			tp_name = prog->aux->attach_func_name;
3050 			break;
3051 		}
3052 		err = bpf_tracing_prog_attach(prog, 0, 0);
3053 		if (err >= 0)
3054 			return err;
3055 		goto out_put_prog;
3056 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3057 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3058 		if (strncpy_from_user(buf,
3059 				      u64_to_user_ptr(attr->raw_tracepoint.name),
3060 				      sizeof(buf) - 1) < 0) {
3061 			err = -EFAULT;
3062 			goto out_put_prog;
3063 		}
3064 		buf[sizeof(buf) - 1] = 0;
3065 		tp_name = buf;
3066 		break;
3067 	default:
3068 		err = -EINVAL;
3069 		goto out_put_prog;
3070 	}
3071 
3072 	btp = bpf_get_raw_tracepoint(tp_name);
3073 	if (!btp) {
3074 		err = -ENOENT;
3075 		goto out_put_prog;
3076 	}
3077 
3078 	link = kzalloc(sizeof(*link), GFP_USER);
3079 	if (!link) {
3080 		err = -ENOMEM;
3081 		goto out_put_btp;
3082 	}
3083 	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3084 		      &bpf_raw_tp_link_lops, prog);
3085 	link->btp = btp;
3086 
3087 	err = bpf_link_prime(&link->link, &link_primer);
3088 	if (err) {
3089 		kfree(link);
3090 		goto out_put_btp;
3091 	}
3092 
3093 	err = bpf_probe_register(link->btp, prog);
3094 	if (err) {
3095 		bpf_link_cleanup(&link_primer);
3096 		goto out_put_btp;
3097 	}
3098 
3099 	return bpf_link_settle(&link_primer);
3100 
3101 out_put_btp:
3102 	bpf_put_raw_tracepoint(btp);
3103 out_put_prog:
3104 	bpf_prog_put(prog);
3105 	return err;
3106 }
3107 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)3108 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
3109 					     enum bpf_attach_type attach_type)
3110 {
3111 	switch (prog->type) {
3112 	case BPF_PROG_TYPE_CGROUP_SOCK:
3113 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3114 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3115 	case BPF_PROG_TYPE_SK_LOOKUP:
3116 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
3117 	case BPF_PROG_TYPE_CGROUP_SKB:
3118 		if (!capable(CAP_NET_ADMIN))
3119 			/* cg-skb progs can be loaded by unpriv user.
3120 			 * check permissions at attach time.
3121 			 */
3122 			return -EPERM;
3123 		return prog->enforce_expected_attach_type &&
3124 			prog->expected_attach_type != attach_type ?
3125 			-EINVAL : 0;
3126 	default:
3127 		return 0;
3128 	}
3129 }
3130 
3131 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)3132 attach_type_to_prog_type(enum bpf_attach_type attach_type)
3133 {
3134 	switch (attach_type) {
3135 	case BPF_CGROUP_INET_INGRESS:
3136 	case BPF_CGROUP_INET_EGRESS:
3137 		return BPF_PROG_TYPE_CGROUP_SKB;
3138 	case BPF_CGROUP_INET_SOCK_CREATE:
3139 	case BPF_CGROUP_INET_SOCK_RELEASE:
3140 	case BPF_CGROUP_INET4_POST_BIND:
3141 	case BPF_CGROUP_INET6_POST_BIND:
3142 		return BPF_PROG_TYPE_CGROUP_SOCK;
3143 	case BPF_CGROUP_INET4_BIND:
3144 	case BPF_CGROUP_INET6_BIND:
3145 	case BPF_CGROUP_INET4_CONNECT:
3146 	case BPF_CGROUP_INET6_CONNECT:
3147 	case BPF_CGROUP_INET4_GETPEERNAME:
3148 	case BPF_CGROUP_INET6_GETPEERNAME:
3149 	case BPF_CGROUP_INET4_GETSOCKNAME:
3150 	case BPF_CGROUP_INET6_GETSOCKNAME:
3151 	case BPF_CGROUP_UDP4_SENDMSG:
3152 	case BPF_CGROUP_UDP6_SENDMSG:
3153 	case BPF_CGROUP_UDP4_RECVMSG:
3154 	case BPF_CGROUP_UDP6_RECVMSG:
3155 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
3156 	case BPF_CGROUP_SOCK_OPS:
3157 		return BPF_PROG_TYPE_SOCK_OPS;
3158 	case BPF_CGROUP_DEVICE:
3159 		return BPF_PROG_TYPE_CGROUP_DEVICE;
3160 	case BPF_SK_MSG_VERDICT:
3161 		return BPF_PROG_TYPE_SK_MSG;
3162 	case BPF_SK_SKB_STREAM_PARSER:
3163 	case BPF_SK_SKB_STREAM_VERDICT:
3164 	case BPF_SK_SKB_VERDICT:
3165 		return BPF_PROG_TYPE_SK_SKB;
3166 	case BPF_LIRC_MODE2:
3167 		return BPF_PROG_TYPE_LIRC_MODE2;
3168 	case BPF_FLOW_DISSECTOR:
3169 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
3170 	case BPF_CGROUP_SYSCTL:
3171 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
3172 	case BPF_CGROUP_GETSOCKOPT:
3173 	case BPF_CGROUP_SETSOCKOPT:
3174 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
3175 	case BPF_TRACE_ITER:
3176 		return BPF_PROG_TYPE_TRACING;
3177 	case BPF_SK_LOOKUP:
3178 		return BPF_PROG_TYPE_SK_LOOKUP;
3179 	case BPF_XDP:
3180 		return BPF_PROG_TYPE_XDP;
3181 	default:
3182 		return BPF_PROG_TYPE_UNSPEC;
3183 	}
3184 }
3185 
3186 #define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd
3187 
3188 #define BPF_F_ATTACH_MASK \
3189 	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)
3190 
bpf_prog_attach(const union bpf_attr * attr)3191 static int bpf_prog_attach(const union bpf_attr *attr)
3192 {
3193 	enum bpf_prog_type ptype;
3194 	struct bpf_prog *prog;
3195 	int ret;
3196 
3197 	if (CHECK_ATTR(BPF_PROG_ATTACH))
3198 		return -EINVAL;
3199 
3200 	if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
3201 		return -EINVAL;
3202 
3203 	ptype = attach_type_to_prog_type(attr->attach_type);
3204 	if (ptype == BPF_PROG_TYPE_UNSPEC)
3205 		return -EINVAL;
3206 
3207 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
3208 	if (IS_ERR(prog))
3209 		return PTR_ERR(prog);
3210 
3211 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
3212 		bpf_prog_put(prog);
3213 		return -EINVAL;
3214 	}
3215 
3216 	switch (ptype) {
3217 	case BPF_PROG_TYPE_SK_SKB:
3218 	case BPF_PROG_TYPE_SK_MSG:
3219 		ret = sock_map_get_from_fd(attr, prog);
3220 		break;
3221 	case BPF_PROG_TYPE_LIRC_MODE2:
3222 		ret = lirc_prog_attach(attr, prog);
3223 		break;
3224 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
3225 		ret = netns_bpf_prog_attach(attr, prog);
3226 		break;
3227 	case BPF_PROG_TYPE_CGROUP_DEVICE:
3228 	case BPF_PROG_TYPE_CGROUP_SKB:
3229 	case BPF_PROG_TYPE_CGROUP_SOCK:
3230 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3231 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3232 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
3233 	case BPF_PROG_TYPE_SOCK_OPS:
3234 		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
3235 		break;
3236 	default:
3237 		ret = -EINVAL;
3238 	}
3239 
3240 	if (ret)
3241 		bpf_prog_put(prog);
3242 	return ret;
3243 }
3244 
3245 #define BPF_PROG_DETACH_LAST_FIELD attach_type
3246 
bpf_prog_detach(const union bpf_attr * attr)3247 static int bpf_prog_detach(const union bpf_attr *attr)
3248 {
3249 	enum bpf_prog_type ptype;
3250 
3251 	if (CHECK_ATTR(BPF_PROG_DETACH))
3252 		return -EINVAL;
3253 
3254 	ptype = attach_type_to_prog_type(attr->attach_type);
3255 
3256 	switch (ptype) {
3257 	case BPF_PROG_TYPE_SK_MSG:
3258 	case BPF_PROG_TYPE_SK_SKB:
3259 		return sock_map_prog_detach(attr, ptype);
3260 	case BPF_PROG_TYPE_LIRC_MODE2:
3261 		return lirc_prog_detach(attr);
3262 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
3263 		return netns_bpf_prog_detach(attr, ptype);
3264 	case BPF_PROG_TYPE_CGROUP_DEVICE:
3265 	case BPF_PROG_TYPE_CGROUP_SKB:
3266 	case BPF_PROG_TYPE_CGROUP_SOCK:
3267 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3268 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3269 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
3270 	case BPF_PROG_TYPE_SOCK_OPS:
3271 		return cgroup_bpf_prog_detach(attr, ptype);
3272 	default:
3273 		return -EINVAL;
3274 	}
3275 }
3276 
3277 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
3278 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)3279 static int bpf_prog_query(const union bpf_attr *attr,
3280 			  union bpf_attr __user *uattr)
3281 {
3282 	if (!capable(CAP_NET_ADMIN))
3283 		return -EPERM;
3284 	if (CHECK_ATTR(BPF_PROG_QUERY))
3285 		return -EINVAL;
3286 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
3287 		return -EINVAL;
3288 
3289 	switch (attr->query.attach_type) {
3290 	case BPF_CGROUP_INET_INGRESS:
3291 	case BPF_CGROUP_INET_EGRESS:
3292 	case BPF_CGROUP_INET_SOCK_CREATE:
3293 	case BPF_CGROUP_INET_SOCK_RELEASE:
3294 	case BPF_CGROUP_INET4_BIND:
3295 	case BPF_CGROUP_INET6_BIND:
3296 	case BPF_CGROUP_INET4_POST_BIND:
3297 	case BPF_CGROUP_INET6_POST_BIND:
3298 	case BPF_CGROUP_INET4_CONNECT:
3299 	case BPF_CGROUP_INET6_CONNECT:
3300 	case BPF_CGROUP_INET4_GETPEERNAME:
3301 	case BPF_CGROUP_INET6_GETPEERNAME:
3302 	case BPF_CGROUP_INET4_GETSOCKNAME:
3303 	case BPF_CGROUP_INET6_GETSOCKNAME:
3304 	case BPF_CGROUP_UDP4_SENDMSG:
3305 	case BPF_CGROUP_UDP6_SENDMSG:
3306 	case BPF_CGROUP_UDP4_RECVMSG:
3307 	case BPF_CGROUP_UDP6_RECVMSG:
3308 	case BPF_CGROUP_SOCK_OPS:
3309 	case BPF_CGROUP_DEVICE:
3310 	case BPF_CGROUP_SYSCTL:
3311 	case BPF_CGROUP_GETSOCKOPT:
3312 	case BPF_CGROUP_SETSOCKOPT:
3313 		return cgroup_bpf_prog_query(attr, uattr);
3314 	case BPF_LIRC_MODE2:
3315 		return lirc_prog_query(attr, uattr);
3316 	case BPF_FLOW_DISSECTOR:
3317 	case BPF_SK_LOOKUP:
3318 		return netns_bpf_prog_query(attr, uattr);
3319 	default:
3320 		return -EINVAL;
3321 	}
3322 }
3323 
3324 #define BPF_PROG_TEST_RUN_LAST_FIELD test.cpu
3325 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)3326 static int bpf_prog_test_run(const union bpf_attr *attr,
3327 			     union bpf_attr __user *uattr)
3328 {
3329 	struct bpf_prog *prog;
3330 	int ret = -ENOTSUPP;
3331 
3332 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
3333 		return -EINVAL;
3334 
3335 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
3336 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
3337 		return -EINVAL;
3338 
3339 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
3340 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
3341 		return -EINVAL;
3342 
3343 	prog = bpf_prog_get(attr->test.prog_fd);
3344 	if (IS_ERR(prog))
3345 		return PTR_ERR(prog);
3346 
3347 	if (prog->aux->ops->test_run)
3348 		ret = prog->aux->ops->test_run(prog, attr, uattr);
3349 
3350 	bpf_prog_put(prog);
3351 	return ret;
3352 }
3353 
3354 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
3355 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)3356 static int bpf_obj_get_next_id(const union bpf_attr *attr,
3357 			       union bpf_attr __user *uattr,
3358 			       struct idr *idr,
3359 			       spinlock_t *lock)
3360 {
3361 	u32 next_id = attr->start_id;
3362 	int err = 0;
3363 
3364 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
3365 		return -EINVAL;
3366 
3367 	if (!capable(CAP_SYS_ADMIN))
3368 		return -EPERM;
3369 
3370 	next_id++;
3371 	spin_lock_bh(lock);
3372 	if (!idr_get_next(idr, &next_id))
3373 		err = -ENOENT;
3374 	spin_unlock_bh(lock);
3375 
3376 	if (!err)
3377 		err = put_user(next_id, &uattr->next_id);
3378 
3379 	return err;
3380 }
3381 
bpf_map_get_curr_or_next(u32 * id)3382 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
3383 {
3384 	struct bpf_map *map;
3385 
3386 	spin_lock_bh(&map_idr_lock);
3387 again:
3388 	map = idr_get_next(&map_idr, id);
3389 	if (map) {
3390 		map = __bpf_map_inc_not_zero(map, false);
3391 		if (IS_ERR(map)) {
3392 			(*id)++;
3393 			goto again;
3394 		}
3395 	}
3396 	spin_unlock_bh(&map_idr_lock);
3397 
3398 	return map;
3399 }
3400 
bpf_prog_get_curr_or_next(u32 * id)3401 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
3402 {
3403 	struct bpf_prog *prog;
3404 
3405 	spin_lock_bh(&prog_idr_lock);
3406 again:
3407 	prog = idr_get_next(&prog_idr, id);
3408 	if (prog) {
3409 		prog = bpf_prog_inc_not_zero(prog);
3410 		if (IS_ERR(prog)) {
3411 			(*id)++;
3412 			goto again;
3413 		}
3414 	}
3415 	spin_unlock_bh(&prog_idr_lock);
3416 
3417 	return prog;
3418 }
3419 
3420 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
3421 
bpf_prog_by_id(u32 id)3422 struct bpf_prog *bpf_prog_by_id(u32 id)
3423 {
3424 	struct bpf_prog *prog;
3425 
3426 	if (!id)
3427 		return ERR_PTR(-ENOENT);
3428 
3429 	spin_lock_bh(&prog_idr_lock);
3430 	prog = idr_find(&prog_idr, id);
3431 	if (prog)
3432 		prog = bpf_prog_inc_not_zero(prog);
3433 	else
3434 		prog = ERR_PTR(-ENOENT);
3435 	spin_unlock_bh(&prog_idr_lock);
3436 	return prog;
3437 }
3438 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)3439 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
3440 {
3441 	struct bpf_prog *prog;
3442 	u32 id = attr->prog_id;
3443 	int fd;
3444 
3445 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
3446 		return -EINVAL;
3447 
3448 	if (!capable(CAP_SYS_ADMIN))
3449 		return -EPERM;
3450 
3451 	prog = bpf_prog_by_id(id);
3452 	if (IS_ERR(prog))
3453 		return PTR_ERR(prog);
3454 
3455 	fd = bpf_prog_new_fd(prog);
3456 	if (fd < 0)
3457 		bpf_prog_put(prog);
3458 
3459 	return fd;
3460 }
3461 
3462 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
3463 
bpf_map_get_fd_by_id(const union bpf_attr * attr)3464 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
3465 {
3466 	struct bpf_map *map;
3467 	u32 id = attr->map_id;
3468 	int f_flags;
3469 	int fd;
3470 
3471 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
3472 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
3473 		return -EINVAL;
3474 
3475 	if (!capable(CAP_SYS_ADMIN))
3476 		return -EPERM;
3477 
3478 	f_flags = bpf_get_file_flag(attr->open_flags);
3479 	if (f_flags < 0)
3480 		return f_flags;
3481 
3482 	spin_lock_bh(&map_idr_lock);
3483 	map = idr_find(&map_idr, id);
3484 	if (map)
3485 		map = __bpf_map_inc_not_zero(map, true);
3486 	else
3487 		map = ERR_PTR(-ENOENT);
3488 	spin_unlock_bh(&map_idr_lock);
3489 
3490 	if (IS_ERR(map))
3491 		return PTR_ERR(map);
3492 
3493 	fd = bpf_map_new_fd(map, f_flags);
3494 	if (fd < 0)
3495 		bpf_map_put_with_uref(map);
3496 
3497 	return fd;
3498 }
3499 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)3500 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
3501 					      unsigned long addr, u32 *off,
3502 					      u32 *type)
3503 {
3504 	const struct bpf_map *map;
3505 	int i;
3506 
3507 	mutex_lock(&prog->aux->used_maps_mutex);
3508 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
3509 		map = prog->aux->used_maps[i];
3510 		if (map == (void *)addr) {
3511 			*type = BPF_PSEUDO_MAP_FD;
3512 			goto out;
3513 		}
3514 		if (!map->ops->map_direct_value_meta)
3515 			continue;
3516 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
3517 			*type = BPF_PSEUDO_MAP_VALUE;
3518 			goto out;
3519 		}
3520 	}
3521 	map = NULL;
3522 
3523 out:
3524 	mutex_unlock(&prog->aux->used_maps_mutex);
3525 	return map;
3526 }
3527 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)3528 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
3529 					      const struct cred *f_cred)
3530 {
3531 	const struct bpf_map *map;
3532 	struct bpf_insn *insns;
3533 	u32 off, type;
3534 	u64 imm;
3535 	u8 code;
3536 	int i;
3537 
3538 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
3539 			GFP_USER);
3540 	if (!insns)
3541 		return insns;
3542 
3543 	for (i = 0; i < prog->len; i++) {
3544 		code = insns[i].code;
3545 
3546 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
3547 			insns[i].code = BPF_JMP | BPF_CALL;
3548 			insns[i].imm = BPF_FUNC_tail_call;
3549 			/* fall-through */
3550 		}
3551 		if (code == (BPF_JMP | BPF_CALL) ||
3552 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
3553 			if (code == (BPF_JMP | BPF_CALL_ARGS))
3554 				insns[i].code = BPF_JMP | BPF_CALL;
3555 			if (!bpf_dump_raw_ok(f_cred))
3556 				insns[i].imm = 0;
3557 			continue;
3558 		}
3559 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
3560 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
3561 			continue;
3562 		}
3563 
3564 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
3565 			continue;
3566 
3567 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
3568 		map = bpf_map_from_imm(prog, imm, &off, &type);
3569 		if (map) {
3570 			insns[i].src_reg = type;
3571 			insns[i].imm = map->id;
3572 			insns[i + 1].imm = off;
3573 			continue;
3574 		}
3575 	}
3576 
3577 	return insns;
3578 }
3579 
set_info_rec_size(struct bpf_prog_info * info)3580 static int set_info_rec_size(struct bpf_prog_info *info)
3581 {
3582 	/*
3583 	 * Ensure info.*_rec_size is the same as kernel expected size
3584 	 *
3585 	 * or
3586 	 *
3587 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
3588 	 * zero.  In this case, the kernel will set the expected
3589 	 * _rec_size back to the info.
3590 	 */
3591 
3592 	if ((info->nr_func_info || info->func_info_rec_size) &&
3593 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
3594 		return -EINVAL;
3595 
3596 	if ((info->nr_line_info || info->line_info_rec_size) &&
3597 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
3598 		return -EINVAL;
3599 
3600 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
3601 	    info->jited_line_info_rec_size != sizeof(__u64))
3602 		return -EINVAL;
3603 
3604 	info->func_info_rec_size = sizeof(struct bpf_func_info);
3605 	info->line_info_rec_size = sizeof(struct bpf_line_info);
3606 	info->jited_line_info_rec_size = sizeof(__u64);
3607 
3608 	return 0;
3609 }
3610 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)3611 static int bpf_prog_get_info_by_fd(struct file *file,
3612 				   struct bpf_prog *prog,
3613 				   const union bpf_attr *attr,
3614 				   union bpf_attr __user *uattr)
3615 {
3616 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3617 	struct bpf_prog_info info;
3618 	u32 info_len = attr->info.info_len;
3619 	struct bpf_prog_kstats stats;
3620 	char __user *uinsns;
3621 	u32 ulen;
3622 	int err;
3623 
3624 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3625 	if (err)
3626 		return err;
3627 	info_len = min_t(u32, sizeof(info), info_len);
3628 
3629 	memset(&info, 0, sizeof(info));
3630 	if (copy_from_user(&info, uinfo, info_len))
3631 		return -EFAULT;
3632 
3633 	info.type = prog->type;
3634 	info.id = prog->aux->id;
3635 	info.load_time = prog->aux->load_time;
3636 	info.created_by_uid = from_kuid_munged(current_user_ns(),
3637 					       prog->aux->user->uid);
3638 	info.gpl_compatible = prog->gpl_compatible;
3639 
3640 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
3641 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
3642 
3643 	mutex_lock(&prog->aux->used_maps_mutex);
3644 	ulen = info.nr_map_ids;
3645 	info.nr_map_ids = prog->aux->used_map_cnt;
3646 	ulen = min_t(u32, info.nr_map_ids, ulen);
3647 	if (ulen) {
3648 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
3649 		u32 i;
3650 
3651 		for (i = 0; i < ulen; i++)
3652 			if (put_user(prog->aux->used_maps[i]->id,
3653 				     &user_map_ids[i])) {
3654 				mutex_unlock(&prog->aux->used_maps_mutex);
3655 				return -EFAULT;
3656 			}
3657 	}
3658 	mutex_unlock(&prog->aux->used_maps_mutex);
3659 
3660 	err = set_info_rec_size(&info);
3661 	if (err)
3662 		return err;
3663 
3664 	bpf_prog_get_stats(prog, &stats);
3665 	info.run_time_ns = stats.nsecs;
3666 	info.run_cnt = stats.cnt;
3667 	info.recursion_misses = stats.misses;
3668 
3669 	if (!bpf_capable()) {
3670 		info.jited_prog_len = 0;
3671 		info.xlated_prog_len = 0;
3672 		info.nr_jited_ksyms = 0;
3673 		info.nr_jited_func_lens = 0;
3674 		info.nr_func_info = 0;
3675 		info.nr_line_info = 0;
3676 		info.nr_jited_line_info = 0;
3677 		goto done;
3678 	}
3679 
3680 	ulen = info.xlated_prog_len;
3681 	info.xlated_prog_len = bpf_prog_insn_size(prog);
3682 	if (info.xlated_prog_len && ulen) {
3683 		struct bpf_insn *insns_sanitized;
3684 		bool fault;
3685 
3686 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
3687 			info.xlated_prog_insns = 0;
3688 			goto done;
3689 		}
3690 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
3691 		if (!insns_sanitized)
3692 			return -ENOMEM;
3693 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
3694 		ulen = min_t(u32, info.xlated_prog_len, ulen);
3695 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
3696 		kfree(insns_sanitized);
3697 		if (fault)
3698 			return -EFAULT;
3699 	}
3700 
3701 	if (bpf_prog_is_dev_bound(prog->aux)) {
3702 		err = bpf_prog_offload_info_fill(&info, prog);
3703 		if (err)
3704 			return err;
3705 		goto done;
3706 	}
3707 
3708 	/* NOTE: the following code is supposed to be skipped for offload.
3709 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
3710 	 * for offload.
3711 	 */
3712 	ulen = info.jited_prog_len;
3713 	if (prog->aux->func_cnt) {
3714 		u32 i;
3715 
3716 		info.jited_prog_len = 0;
3717 		for (i = 0; i < prog->aux->func_cnt; i++)
3718 			info.jited_prog_len += prog->aux->func[i]->jited_len;
3719 	} else {
3720 		info.jited_prog_len = prog->jited_len;
3721 	}
3722 
3723 	if (info.jited_prog_len && ulen) {
3724 		if (bpf_dump_raw_ok(file->f_cred)) {
3725 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
3726 			ulen = min_t(u32, info.jited_prog_len, ulen);
3727 
3728 			/* for multi-function programs, copy the JITed
3729 			 * instructions for all the functions
3730 			 */
3731 			if (prog->aux->func_cnt) {
3732 				u32 len, free, i;
3733 				u8 *img;
3734 
3735 				free = ulen;
3736 				for (i = 0; i < prog->aux->func_cnt; i++) {
3737 					len = prog->aux->func[i]->jited_len;
3738 					len = min_t(u32, len, free);
3739 					img = (u8 *) prog->aux->func[i]->bpf_func;
3740 					if (copy_to_user(uinsns, img, len))
3741 						return -EFAULT;
3742 					uinsns += len;
3743 					free -= len;
3744 					if (!free)
3745 						break;
3746 				}
3747 			} else {
3748 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
3749 					return -EFAULT;
3750 			}
3751 		} else {
3752 			info.jited_prog_insns = 0;
3753 		}
3754 	}
3755 
3756 	ulen = info.nr_jited_ksyms;
3757 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
3758 	if (ulen) {
3759 		if (bpf_dump_raw_ok(file->f_cred)) {
3760 			unsigned long ksym_addr;
3761 			u64 __user *user_ksyms;
3762 			u32 i;
3763 
3764 			/* copy the address of the kernel symbol
3765 			 * corresponding to each function
3766 			 */
3767 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
3768 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
3769 			if (prog->aux->func_cnt) {
3770 				for (i = 0; i < ulen; i++) {
3771 					ksym_addr = (unsigned long)
3772 						prog->aux->func[i]->bpf_func;
3773 					if (put_user((u64) ksym_addr,
3774 						     &user_ksyms[i]))
3775 						return -EFAULT;
3776 				}
3777 			} else {
3778 				ksym_addr = (unsigned long) prog->bpf_func;
3779 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
3780 					return -EFAULT;
3781 			}
3782 		} else {
3783 			info.jited_ksyms = 0;
3784 		}
3785 	}
3786 
3787 	ulen = info.nr_jited_func_lens;
3788 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
3789 	if (ulen) {
3790 		if (bpf_dump_raw_ok(file->f_cred)) {
3791 			u32 __user *user_lens;
3792 			u32 func_len, i;
3793 
3794 			/* copy the JITed image lengths for each function */
3795 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
3796 			user_lens = u64_to_user_ptr(info.jited_func_lens);
3797 			if (prog->aux->func_cnt) {
3798 				for (i = 0; i < ulen; i++) {
3799 					func_len =
3800 						prog->aux->func[i]->jited_len;
3801 					if (put_user(func_len, &user_lens[i]))
3802 						return -EFAULT;
3803 				}
3804 			} else {
3805 				func_len = prog->jited_len;
3806 				if (put_user(func_len, &user_lens[0]))
3807 					return -EFAULT;
3808 			}
3809 		} else {
3810 			info.jited_func_lens = 0;
3811 		}
3812 	}
3813 
3814 	if (prog->aux->btf)
3815 		info.btf_id = btf_obj_id(prog->aux->btf);
3816 
3817 	ulen = info.nr_func_info;
3818 	info.nr_func_info = prog->aux->func_info_cnt;
3819 	if (info.nr_func_info && ulen) {
3820 		char __user *user_finfo;
3821 
3822 		user_finfo = u64_to_user_ptr(info.func_info);
3823 		ulen = min_t(u32, info.nr_func_info, ulen);
3824 		if (copy_to_user(user_finfo, prog->aux->func_info,
3825 				 info.func_info_rec_size * ulen))
3826 			return -EFAULT;
3827 	}
3828 
3829 	ulen = info.nr_line_info;
3830 	info.nr_line_info = prog->aux->nr_linfo;
3831 	if (info.nr_line_info && ulen) {
3832 		__u8 __user *user_linfo;
3833 
3834 		user_linfo = u64_to_user_ptr(info.line_info);
3835 		ulen = min_t(u32, info.nr_line_info, ulen);
3836 		if (copy_to_user(user_linfo, prog->aux->linfo,
3837 				 info.line_info_rec_size * ulen))
3838 			return -EFAULT;
3839 	}
3840 
3841 	ulen = info.nr_jited_line_info;
3842 	if (prog->aux->jited_linfo)
3843 		info.nr_jited_line_info = prog->aux->nr_linfo;
3844 	else
3845 		info.nr_jited_line_info = 0;
3846 	if (info.nr_jited_line_info && ulen) {
3847 		if (bpf_dump_raw_ok(file->f_cred)) {
3848 			__u64 __user *user_linfo;
3849 			u32 i;
3850 
3851 			user_linfo = u64_to_user_ptr(info.jited_line_info);
3852 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
3853 			for (i = 0; i < ulen; i++) {
3854 				if (put_user((__u64)(long)prog->aux->jited_linfo[i],
3855 					     &user_linfo[i]))
3856 					return -EFAULT;
3857 			}
3858 		} else {
3859 			info.jited_line_info = 0;
3860 		}
3861 	}
3862 
3863 	ulen = info.nr_prog_tags;
3864 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
3865 	if (ulen) {
3866 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
3867 		u32 i;
3868 
3869 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
3870 		ulen = min_t(u32, info.nr_prog_tags, ulen);
3871 		if (prog->aux->func_cnt) {
3872 			for (i = 0; i < ulen; i++) {
3873 				if (copy_to_user(user_prog_tags[i],
3874 						 prog->aux->func[i]->tag,
3875 						 BPF_TAG_SIZE))
3876 					return -EFAULT;
3877 			}
3878 		} else {
3879 			if (copy_to_user(user_prog_tags[0],
3880 					 prog->tag, BPF_TAG_SIZE))
3881 				return -EFAULT;
3882 		}
3883 	}
3884 
3885 done:
3886 	if (copy_to_user(uinfo, &info, info_len) ||
3887 	    put_user(info_len, &uattr->info.info_len))
3888 		return -EFAULT;
3889 
3890 	return 0;
3891 }
3892 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)3893 static int bpf_map_get_info_by_fd(struct file *file,
3894 				  struct bpf_map *map,
3895 				  const union bpf_attr *attr,
3896 				  union bpf_attr __user *uattr)
3897 {
3898 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3899 	struct bpf_map_info info;
3900 	u32 info_len = attr->info.info_len;
3901 	int err;
3902 
3903 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3904 	if (err)
3905 		return err;
3906 	info_len = min_t(u32, sizeof(info), info_len);
3907 
3908 	memset(&info, 0, sizeof(info));
3909 	info.type = map->map_type;
3910 	info.id = map->id;
3911 	info.key_size = map->key_size;
3912 	info.value_size = map->value_size;
3913 	info.max_entries = map->max_entries;
3914 	info.map_flags = map->map_flags;
3915 	memcpy(info.name, map->name, sizeof(map->name));
3916 
3917 	if (map->btf) {
3918 		info.btf_id = btf_obj_id(map->btf);
3919 		info.btf_key_type_id = map->btf_key_type_id;
3920 		info.btf_value_type_id = map->btf_value_type_id;
3921 	}
3922 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
3923 
3924 	if (bpf_map_is_dev_bound(map)) {
3925 		err = bpf_map_offload_info_fill(&info, map);
3926 		if (err)
3927 			return err;
3928 	}
3929 
3930 	if (copy_to_user(uinfo, &info, info_len) ||
3931 	    put_user(info_len, &uattr->info.info_len))
3932 		return -EFAULT;
3933 
3934 	return 0;
3935 }
3936 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)3937 static int bpf_btf_get_info_by_fd(struct file *file,
3938 				  struct btf *btf,
3939 				  const union bpf_attr *attr,
3940 				  union bpf_attr __user *uattr)
3941 {
3942 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3943 	u32 info_len = attr->info.info_len;
3944 	int err;
3945 
3946 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
3947 	if (err)
3948 		return err;
3949 
3950 	return btf_get_info_by_fd(btf, attr, uattr);
3951 }
3952 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)3953 static int bpf_link_get_info_by_fd(struct file *file,
3954 				  struct bpf_link *link,
3955 				  const union bpf_attr *attr,
3956 				  union bpf_attr __user *uattr)
3957 {
3958 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
3959 	struct bpf_link_info info;
3960 	u32 info_len = attr->info.info_len;
3961 	int err;
3962 
3963 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
3964 	if (err)
3965 		return err;
3966 	info_len = min_t(u32, sizeof(info), info_len);
3967 
3968 	memset(&info, 0, sizeof(info));
3969 	if (copy_from_user(&info, uinfo, info_len))
3970 		return -EFAULT;
3971 
3972 	info.type = link->type;
3973 	info.id = link->id;
3974 	info.prog_id = link->prog->aux->id;
3975 
3976 	if (link->ops->fill_link_info) {
3977 		err = link->ops->fill_link_info(link, &info);
3978 		if (err)
3979 			return err;
3980 	}
3981 
3982 	if (copy_to_user(uinfo, &info, info_len) ||
3983 	    put_user(info_len, &uattr->info.info_len))
3984 		return -EFAULT;
3985 
3986 	return 0;
3987 }
3988 
3989 
3990 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
3991 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)3992 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
3993 				  union bpf_attr __user *uattr)
3994 {
3995 	int ufd = attr->info.bpf_fd;
3996 	struct fd f;
3997 	int err;
3998 
3999 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
4000 		return -EINVAL;
4001 
4002 	f = fdget(ufd);
4003 	if (!f.file)
4004 		return -EBADFD;
4005 
4006 	if (f.file->f_op == &bpf_prog_fops)
4007 		err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
4008 					      uattr);
4009 	else if (f.file->f_op == &bpf_map_fops)
4010 		err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
4011 					     uattr);
4012 	else if (f.file->f_op == &btf_fops)
4013 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
4014 	else if (f.file->f_op == &bpf_link_fops)
4015 		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
4016 					      attr, uattr);
4017 	else
4018 		err = -EINVAL;
4019 
4020 	fdput(f);
4021 	return err;
4022 }
4023 
4024 #define BPF_BTF_LOAD_LAST_FIELD btf_log_level
4025 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr)4026 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr)
4027 {
4028 	if (CHECK_ATTR(BPF_BTF_LOAD))
4029 		return -EINVAL;
4030 
4031 	if (!bpf_capable())
4032 		return -EPERM;
4033 
4034 	return btf_new_fd(attr, uattr);
4035 }
4036 
4037 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
4038 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)4039 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
4040 {
4041 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
4042 		return -EINVAL;
4043 
4044 	if (!capable(CAP_SYS_ADMIN))
4045 		return -EPERM;
4046 
4047 	return btf_get_fd_by_id(attr->btf_id);
4048 }
4049 
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)4050 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
4051 				    union bpf_attr __user *uattr,
4052 				    u32 prog_id, u32 fd_type,
4053 				    const char *buf, u64 probe_offset,
4054 				    u64 probe_addr)
4055 {
4056 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
4057 	u32 len = buf ? strlen(buf) : 0, input_len;
4058 	int err = 0;
4059 
4060 	if (put_user(len, &uattr->task_fd_query.buf_len))
4061 		return -EFAULT;
4062 	input_len = attr->task_fd_query.buf_len;
4063 	if (input_len && ubuf) {
4064 		if (!len) {
4065 			/* nothing to copy, just make ubuf NULL terminated */
4066 			char zero = '\0';
4067 
4068 			if (put_user(zero, ubuf))
4069 				return -EFAULT;
4070 		} else if (input_len >= len + 1) {
4071 			/* ubuf can hold the string with NULL terminator */
4072 			if (copy_to_user(ubuf, buf, len + 1))
4073 				return -EFAULT;
4074 		} else {
4075 			/* ubuf cannot hold the string with NULL terminator,
4076 			 * do a partial copy with NULL terminator.
4077 			 */
4078 			char zero = '\0';
4079 
4080 			err = -ENOSPC;
4081 			if (copy_to_user(ubuf, buf, input_len - 1))
4082 				return -EFAULT;
4083 			if (put_user(zero, ubuf + input_len - 1))
4084 				return -EFAULT;
4085 		}
4086 	}
4087 
4088 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
4089 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
4090 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
4091 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
4092 		return -EFAULT;
4093 
4094 	return err;
4095 }
4096 
4097 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
4098 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4099 static int bpf_task_fd_query(const union bpf_attr *attr,
4100 			     union bpf_attr __user *uattr)
4101 {
4102 	pid_t pid = attr->task_fd_query.pid;
4103 	u32 fd = attr->task_fd_query.fd;
4104 	const struct perf_event *event;
4105 	struct task_struct *task;
4106 	struct file *file;
4107 	int err;
4108 
4109 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
4110 		return -EINVAL;
4111 
4112 	if (!capable(CAP_SYS_ADMIN))
4113 		return -EPERM;
4114 
4115 	if (attr->task_fd_query.flags != 0)
4116 		return -EINVAL;
4117 
4118 	rcu_read_lock();
4119 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
4120 	rcu_read_unlock();
4121 	if (!task)
4122 		return -ENOENT;
4123 
4124 	err = 0;
4125 	file = fget_task(task, fd);
4126 	put_task_struct(task);
4127 	if (!file)
4128 		return -EBADF;
4129 
4130 	if (file->f_op == &bpf_link_fops) {
4131 		struct bpf_link *link = file->private_data;
4132 
4133 		if (link->ops == &bpf_raw_tp_link_lops) {
4134 			struct bpf_raw_tp_link *raw_tp =
4135 				container_of(link, struct bpf_raw_tp_link, link);
4136 			struct bpf_raw_event_map *btp = raw_tp->btp;
4137 
4138 			err = bpf_task_fd_query_copy(attr, uattr,
4139 						     raw_tp->link.prog->aux->id,
4140 						     BPF_FD_TYPE_RAW_TRACEPOINT,
4141 						     btp->tp->name, 0, 0);
4142 			goto put_file;
4143 		}
4144 		goto out_not_supp;
4145 	}
4146 
4147 	event = perf_get_event(file);
4148 	if (!IS_ERR(event)) {
4149 		u64 probe_offset, probe_addr;
4150 		u32 prog_id, fd_type;
4151 		const char *buf;
4152 
4153 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
4154 					      &buf, &probe_offset,
4155 					      &probe_addr);
4156 		if (!err)
4157 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
4158 						     fd_type, buf,
4159 						     probe_offset,
4160 						     probe_addr);
4161 		goto put_file;
4162 	}
4163 
4164 out_not_supp:
4165 	err = -ENOTSUPP;
4166 put_file:
4167 	fput(file);
4168 	return err;
4169 }
4170 
4171 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
4172 
4173 #define BPF_DO_BATCH(fn)			\
4174 	do {					\
4175 		if (!fn) {			\
4176 			err = -ENOTSUPP;	\
4177 			goto err_put;		\
4178 		}				\
4179 		err = fn(map, attr, uattr);	\
4180 	} while (0)
4181 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)4182 static int bpf_map_do_batch(const union bpf_attr *attr,
4183 			    union bpf_attr __user *uattr,
4184 			    int cmd)
4185 {
4186 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
4187 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
4188 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
4189 	struct bpf_map *map;
4190 	int err, ufd;
4191 	struct fd f;
4192 
4193 	if (CHECK_ATTR(BPF_MAP_BATCH))
4194 		return -EINVAL;
4195 
4196 	ufd = attr->batch.map_fd;
4197 	f = fdget(ufd);
4198 	map = __bpf_map_get(f);
4199 	if (IS_ERR(map))
4200 		return PTR_ERR(map);
4201 	if (has_write)
4202 		bpf_map_write_active_inc(map);
4203 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
4204 		err = -EPERM;
4205 		goto err_put;
4206 	}
4207 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
4208 		err = -EPERM;
4209 		goto err_put;
4210 	}
4211 
4212 	if (cmd == BPF_MAP_LOOKUP_BATCH)
4213 		BPF_DO_BATCH(map->ops->map_lookup_batch);
4214 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
4215 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch);
4216 	else if (cmd == BPF_MAP_UPDATE_BATCH)
4217 		BPF_DO_BATCH(map->ops->map_update_batch);
4218 	else
4219 		BPF_DO_BATCH(map->ops->map_delete_batch);
4220 err_put:
4221 	if (has_write)
4222 		bpf_map_write_active_dec(map);
4223 	fdput(f);
4224 	return err;
4225 }
4226 
tracing_bpf_link_attach(const union bpf_attr * attr,bpfptr_t uattr,struct bpf_prog * prog)4227 static int tracing_bpf_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
4228 				   struct bpf_prog *prog)
4229 {
4230 	if (attr->link_create.attach_type != prog->expected_attach_type)
4231 		return -EINVAL;
4232 
4233 	if (prog->expected_attach_type == BPF_TRACE_ITER)
4234 		return bpf_iter_link_attach(attr, uattr, prog);
4235 	else if (prog->type == BPF_PROG_TYPE_EXT)
4236 		return bpf_tracing_prog_attach(prog,
4237 					       attr->link_create.target_fd,
4238 					       attr->link_create.target_btf_id);
4239 	return -EINVAL;
4240 }
4241 
4242 #define BPF_LINK_CREATE_LAST_FIELD link_create.iter_info_len
link_create(union bpf_attr * attr,bpfptr_t uattr)4243 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
4244 {
4245 	enum bpf_prog_type ptype;
4246 	struct bpf_prog *prog;
4247 	int ret;
4248 
4249 	if (CHECK_ATTR(BPF_LINK_CREATE))
4250 		return -EINVAL;
4251 
4252 	prog = bpf_prog_get(attr->link_create.prog_fd);
4253 	if (IS_ERR(prog))
4254 		return PTR_ERR(prog);
4255 
4256 	ret = bpf_prog_attach_check_attach_type(prog,
4257 						attr->link_create.attach_type);
4258 	if (ret)
4259 		goto out;
4260 
4261 	switch (prog->type) {
4262 	case BPF_PROG_TYPE_EXT:
4263 		ret = tracing_bpf_link_attach(attr, uattr, prog);
4264 		goto out;
4265 	case BPF_PROG_TYPE_PERF_EVENT:
4266 	case BPF_PROG_TYPE_KPROBE:
4267 	case BPF_PROG_TYPE_TRACEPOINT:
4268 		if (attr->link_create.attach_type != BPF_PERF_EVENT) {
4269 			ret = -EINVAL;
4270 			goto out;
4271 		}
4272 		ptype = prog->type;
4273 		break;
4274 	default:
4275 		ptype = attach_type_to_prog_type(attr->link_create.attach_type);
4276 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type) {
4277 			ret = -EINVAL;
4278 			goto out;
4279 		}
4280 		break;
4281 	}
4282 
4283 	switch (ptype) {
4284 	case BPF_PROG_TYPE_CGROUP_SKB:
4285 	case BPF_PROG_TYPE_CGROUP_SOCK:
4286 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4287 	case BPF_PROG_TYPE_SOCK_OPS:
4288 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4289 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4290 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4291 		ret = cgroup_bpf_link_attach(attr, prog);
4292 		break;
4293 	case BPF_PROG_TYPE_TRACING:
4294 		ret = tracing_bpf_link_attach(attr, uattr, prog);
4295 		break;
4296 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4297 	case BPF_PROG_TYPE_SK_LOOKUP:
4298 		ret = netns_bpf_link_create(attr, prog);
4299 		break;
4300 #ifdef CONFIG_NET
4301 	case BPF_PROG_TYPE_XDP:
4302 		ret = bpf_xdp_link_attach(attr, prog);
4303 		break;
4304 #endif
4305 #ifdef CONFIG_PERF_EVENTS
4306 	case BPF_PROG_TYPE_PERF_EVENT:
4307 	case BPF_PROG_TYPE_TRACEPOINT:
4308 	case BPF_PROG_TYPE_KPROBE:
4309 		ret = bpf_perf_link_attach(attr, prog);
4310 		break;
4311 #endif
4312 	default:
4313 		ret = -EINVAL;
4314 	}
4315 
4316 out:
4317 	if (ret < 0)
4318 		bpf_prog_put(prog);
4319 	return ret;
4320 }
4321 
4322 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
4323 
link_update(union bpf_attr * attr)4324 static int link_update(union bpf_attr *attr)
4325 {
4326 	struct bpf_prog *old_prog = NULL, *new_prog;
4327 	struct bpf_link *link;
4328 	u32 flags;
4329 	int ret;
4330 
4331 	if (CHECK_ATTR(BPF_LINK_UPDATE))
4332 		return -EINVAL;
4333 
4334 	flags = attr->link_update.flags;
4335 	if (flags & ~BPF_F_REPLACE)
4336 		return -EINVAL;
4337 
4338 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
4339 	if (IS_ERR(link))
4340 		return PTR_ERR(link);
4341 
4342 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
4343 	if (IS_ERR(new_prog)) {
4344 		ret = PTR_ERR(new_prog);
4345 		goto out_put_link;
4346 	}
4347 
4348 	if (flags & BPF_F_REPLACE) {
4349 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
4350 		if (IS_ERR(old_prog)) {
4351 			ret = PTR_ERR(old_prog);
4352 			old_prog = NULL;
4353 			goto out_put_progs;
4354 		}
4355 	} else if (attr->link_update.old_prog_fd) {
4356 		ret = -EINVAL;
4357 		goto out_put_progs;
4358 	}
4359 
4360 	if (link->ops->update_prog)
4361 		ret = link->ops->update_prog(link, new_prog, old_prog);
4362 	else
4363 		ret = -EINVAL;
4364 
4365 out_put_progs:
4366 	if (old_prog)
4367 		bpf_prog_put(old_prog);
4368 	if (ret)
4369 		bpf_prog_put(new_prog);
4370 out_put_link:
4371 	bpf_link_put(link);
4372 	return ret;
4373 }
4374 
4375 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
4376 
link_detach(union bpf_attr * attr)4377 static int link_detach(union bpf_attr *attr)
4378 {
4379 	struct bpf_link *link;
4380 	int ret;
4381 
4382 	if (CHECK_ATTR(BPF_LINK_DETACH))
4383 		return -EINVAL;
4384 
4385 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
4386 	if (IS_ERR(link))
4387 		return PTR_ERR(link);
4388 
4389 	if (link->ops->detach)
4390 		ret = link->ops->detach(link);
4391 	else
4392 		ret = -EOPNOTSUPP;
4393 
4394 	bpf_link_put(link);
4395 	return ret;
4396 }
4397 
bpf_link_inc_not_zero(struct bpf_link * link)4398 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
4399 {
4400 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
4401 }
4402 
bpf_link_by_id(u32 id)4403 struct bpf_link *bpf_link_by_id(u32 id)
4404 {
4405 	struct bpf_link *link;
4406 
4407 	if (!id)
4408 		return ERR_PTR(-ENOENT);
4409 
4410 	spin_lock_bh(&link_idr_lock);
4411 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
4412 	link = idr_find(&link_idr, id);
4413 	if (link) {
4414 		if (link->id)
4415 			link = bpf_link_inc_not_zero(link);
4416 		else
4417 			link = ERR_PTR(-EAGAIN);
4418 	} else {
4419 		link = ERR_PTR(-ENOENT);
4420 	}
4421 	spin_unlock_bh(&link_idr_lock);
4422 	return link;
4423 }
4424 
4425 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
4426 
bpf_link_get_fd_by_id(const union bpf_attr * attr)4427 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
4428 {
4429 	struct bpf_link *link;
4430 	u32 id = attr->link_id;
4431 	int fd;
4432 
4433 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
4434 		return -EINVAL;
4435 
4436 	if (!capable(CAP_SYS_ADMIN))
4437 		return -EPERM;
4438 
4439 	link = bpf_link_by_id(id);
4440 	if (IS_ERR(link))
4441 		return PTR_ERR(link);
4442 
4443 	fd = bpf_link_new_fd(link);
4444 	if (fd < 0)
4445 		bpf_link_put(link);
4446 
4447 	return fd;
4448 }
4449 
4450 DEFINE_MUTEX(bpf_stats_enabled_mutex);
4451 
bpf_stats_release(struct inode * inode,struct file * file)4452 static int bpf_stats_release(struct inode *inode, struct file *file)
4453 {
4454 	mutex_lock(&bpf_stats_enabled_mutex);
4455 	static_key_slow_dec(&bpf_stats_enabled_key.key);
4456 	mutex_unlock(&bpf_stats_enabled_mutex);
4457 	return 0;
4458 }
4459 
4460 static const struct file_operations bpf_stats_fops = {
4461 	.release = bpf_stats_release,
4462 };
4463 
bpf_enable_runtime_stats(void)4464 static int bpf_enable_runtime_stats(void)
4465 {
4466 	int fd;
4467 
4468 	mutex_lock(&bpf_stats_enabled_mutex);
4469 
4470 	/* Set a very high limit to avoid overflow */
4471 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
4472 		mutex_unlock(&bpf_stats_enabled_mutex);
4473 		return -EBUSY;
4474 	}
4475 
4476 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
4477 	if (fd >= 0)
4478 		static_key_slow_inc(&bpf_stats_enabled_key.key);
4479 
4480 	mutex_unlock(&bpf_stats_enabled_mutex);
4481 	return fd;
4482 }
4483 
4484 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
4485 
bpf_enable_stats(union bpf_attr * attr)4486 static int bpf_enable_stats(union bpf_attr *attr)
4487 {
4488 
4489 	if (CHECK_ATTR(BPF_ENABLE_STATS))
4490 		return -EINVAL;
4491 
4492 	if (!capable(CAP_SYS_ADMIN))
4493 		return -EPERM;
4494 
4495 	switch (attr->enable_stats.type) {
4496 	case BPF_STATS_RUN_TIME:
4497 		return bpf_enable_runtime_stats();
4498 	default:
4499 		break;
4500 	}
4501 	return -EINVAL;
4502 }
4503 
4504 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
4505 
bpf_iter_create(union bpf_attr * attr)4506 static int bpf_iter_create(union bpf_attr *attr)
4507 {
4508 	struct bpf_link *link;
4509 	int err;
4510 
4511 	if (CHECK_ATTR(BPF_ITER_CREATE))
4512 		return -EINVAL;
4513 
4514 	if (attr->iter_create.flags)
4515 		return -EINVAL;
4516 
4517 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
4518 	if (IS_ERR(link))
4519 		return PTR_ERR(link);
4520 
4521 	err = bpf_iter_new_fd(link);
4522 	bpf_link_put(link);
4523 
4524 	return err;
4525 }
4526 
4527 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
4528 
bpf_prog_bind_map(union bpf_attr * attr)4529 static int bpf_prog_bind_map(union bpf_attr *attr)
4530 {
4531 	struct bpf_prog *prog;
4532 	struct bpf_map *map;
4533 	struct bpf_map **used_maps_old, **used_maps_new;
4534 	int i, ret = 0;
4535 
4536 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
4537 		return -EINVAL;
4538 
4539 	if (attr->prog_bind_map.flags)
4540 		return -EINVAL;
4541 
4542 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
4543 	if (IS_ERR(prog))
4544 		return PTR_ERR(prog);
4545 
4546 	map = bpf_map_get(attr->prog_bind_map.map_fd);
4547 	if (IS_ERR(map)) {
4548 		ret = PTR_ERR(map);
4549 		goto out_prog_put;
4550 	}
4551 
4552 	mutex_lock(&prog->aux->used_maps_mutex);
4553 
4554 	used_maps_old = prog->aux->used_maps;
4555 
4556 	for (i = 0; i < prog->aux->used_map_cnt; i++)
4557 		if (used_maps_old[i] == map) {
4558 			bpf_map_put(map);
4559 			goto out_unlock;
4560 		}
4561 
4562 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
4563 				      sizeof(used_maps_new[0]),
4564 				      GFP_KERNEL);
4565 	if (!used_maps_new) {
4566 		ret = -ENOMEM;
4567 		goto out_unlock;
4568 	}
4569 
4570 	memcpy(used_maps_new, used_maps_old,
4571 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
4572 	used_maps_new[prog->aux->used_map_cnt] = map;
4573 
4574 	prog->aux->used_map_cnt++;
4575 	prog->aux->used_maps = used_maps_new;
4576 
4577 	kfree(used_maps_old);
4578 
4579 out_unlock:
4580 	mutex_unlock(&prog->aux->used_maps_mutex);
4581 
4582 	if (ret)
4583 		bpf_map_put(map);
4584 out_prog_put:
4585 	bpf_prog_put(prog);
4586 	return ret;
4587 }
4588 
__sys_bpf(int cmd,bpfptr_t uattr,unsigned int size)4589 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
4590 {
4591 	union bpf_attr attr;
4592 	int err;
4593 
4594 	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
4595 		return -EPERM;
4596 
4597 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
4598 	if (err)
4599 		return err;
4600 	size = min_t(u32, size, sizeof(attr));
4601 
4602 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
4603 	memset(&attr, 0, sizeof(attr));
4604 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
4605 		return -EFAULT;
4606 
4607 	trace_android_vh_check_bpf_syscall(cmd, &attr, size);
4608 
4609 	err = security_bpf(cmd, &attr, size);
4610 	if (err < 0)
4611 		return err;
4612 
4613 	switch (cmd) {
4614 	case BPF_MAP_CREATE:
4615 		err = map_create(&attr);
4616 		break;
4617 	case BPF_MAP_LOOKUP_ELEM:
4618 		err = map_lookup_elem(&attr);
4619 		break;
4620 	case BPF_MAP_UPDATE_ELEM:
4621 		err = map_update_elem(&attr, uattr);
4622 		break;
4623 	case BPF_MAP_DELETE_ELEM:
4624 		err = map_delete_elem(&attr);
4625 		break;
4626 	case BPF_MAP_GET_NEXT_KEY:
4627 		err = map_get_next_key(&attr);
4628 		break;
4629 	case BPF_MAP_FREEZE:
4630 		err = map_freeze(&attr);
4631 		break;
4632 	case BPF_PROG_LOAD:
4633 		err = bpf_prog_load(&attr, uattr);
4634 		break;
4635 	case BPF_OBJ_PIN:
4636 		err = bpf_obj_pin(&attr);
4637 		break;
4638 	case BPF_OBJ_GET:
4639 		err = bpf_obj_get(&attr);
4640 		break;
4641 	case BPF_PROG_ATTACH:
4642 		err = bpf_prog_attach(&attr);
4643 		break;
4644 	case BPF_PROG_DETACH:
4645 		err = bpf_prog_detach(&attr);
4646 		break;
4647 	case BPF_PROG_QUERY:
4648 		err = bpf_prog_query(&attr, uattr.user);
4649 		break;
4650 	case BPF_PROG_TEST_RUN:
4651 		err = bpf_prog_test_run(&attr, uattr.user);
4652 		break;
4653 	case BPF_PROG_GET_NEXT_ID:
4654 		err = bpf_obj_get_next_id(&attr, uattr.user,
4655 					  &prog_idr, &prog_idr_lock);
4656 		break;
4657 	case BPF_MAP_GET_NEXT_ID:
4658 		err = bpf_obj_get_next_id(&attr, uattr.user,
4659 					  &map_idr, &map_idr_lock);
4660 		break;
4661 	case BPF_BTF_GET_NEXT_ID:
4662 		err = bpf_obj_get_next_id(&attr, uattr.user,
4663 					  &btf_idr, &btf_idr_lock);
4664 		break;
4665 	case BPF_PROG_GET_FD_BY_ID:
4666 		err = bpf_prog_get_fd_by_id(&attr);
4667 		break;
4668 	case BPF_MAP_GET_FD_BY_ID:
4669 		err = bpf_map_get_fd_by_id(&attr);
4670 		break;
4671 	case BPF_OBJ_GET_INFO_BY_FD:
4672 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
4673 		break;
4674 	case BPF_RAW_TRACEPOINT_OPEN:
4675 		err = bpf_raw_tracepoint_open(&attr);
4676 		break;
4677 	case BPF_BTF_LOAD:
4678 		err = bpf_btf_load(&attr, uattr);
4679 		break;
4680 	case BPF_BTF_GET_FD_BY_ID:
4681 		err = bpf_btf_get_fd_by_id(&attr);
4682 		break;
4683 	case BPF_TASK_FD_QUERY:
4684 		err = bpf_task_fd_query(&attr, uattr.user);
4685 		break;
4686 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
4687 		err = map_lookup_and_delete_elem(&attr);
4688 		break;
4689 	case BPF_MAP_LOOKUP_BATCH:
4690 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
4691 		break;
4692 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
4693 		err = bpf_map_do_batch(&attr, uattr.user,
4694 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
4695 		break;
4696 	case BPF_MAP_UPDATE_BATCH:
4697 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
4698 		break;
4699 	case BPF_MAP_DELETE_BATCH:
4700 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
4701 		break;
4702 	case BPF_LINK_CREATE:
4703 		err = link_create(&attr, uattr);
4704 		break;
4705 	case BPF_LINK_UPDATE:
4706 		err = link_update(&attr);
4707 		break;
4708 	case BPF_LINK_GET_FD_BY_ID:
4709 		err = bpf_link_get_fd_by_id(&attr);
4710 		break;
4711 	case BPF_LINK_GET_NEXT_ID:
4712 		err = bpf_obj_get_next_id(&attr, uattr.user,
4713 					  &link_idr, &link_idr_lock);
4714 		break;
4715 	case BPF_ENABLE_STATS:
4716 		err = bpf_enable_stats(&attr);
4717 		break;
4718 	case BPF_ITER_CREATE:
4719 		err = bpf_iter_create(&attr);
4720 		break;
4721 	case BPF_LINK_DETACH:
4722 		err = link_detach(&attr);
4723 		break;
4724 	case BPF_PROG_BIND_MAP:
4725 		err = bpf_prog_bind_map(&attr);
4726 		break;
4727 	default:
4728 		err = -EINVAL;
4729 		break;
4730 	}
4731 
4732 	return err;
4733 }
4734 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)4735 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
4736 {
4737 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
4738 }
4739 
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)4740 static bool syscall_prog_is_valid_access(int off, int size,
4741 					 enum bpf_access_type type,
4742 					 const struct bpf_prog *prog,
4743 					 struct bpf_insn_access_aux *info)
4744 {
4745 	if (off < 0 || off >= U16_MAX)
4746 		return false;
4747 	if (off % size != 0)
4748 		return false;
4749 	return true;
4750 }
4751 
BPF_CALL_3(bpf_sys_bpf,int,cmd,void *,attr,u32,attr_size)4752 BPF_CALL_3(bpf_sys_bpf, int, cmd, void *, attr, u32, attr_size)
4753 {
4754 	switch (cmd) {
4755 	case BPF_MAP_CREATE:
4756 	case BPF_MAP_UPDATE_ELEM:
4757 	case BPF_MAP_FREEZE:
4758 	case BPF_PROG_LOAD:
4759 	case BPF_BTF_LOAD:
4760 		break;
4761 	/* case BPF_PROG_TEST_RUN:
4762 	 * is not part of this list to prevent recursive test_run
4763 	 */
4764 	default:
4765 		return -EINVAL;
4766 	}
4767 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
4768 }
4769 
4770 static const struct bpf_func_proto bpf_sys_bpf_proto = {
4771 	.func		= bpf_sys_bpf,
4772 	.gpl_only	= false,
4773 	.ret_type	= RET_INTEGER,
4774 	.arg1_type	= ARG_ANYTHING,
4775 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
4776 	.arg3_type	= ARG_CONST_SIZE,
4777 };
4778 
4779 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)4780 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
4781 {
4782 	return bpf_base_func_proto(func_id);
4783 }
4784 
BPF_CALL_1(bpf_sys_close,u32,fd)4785 BPF_CALL_1(bpf_sys_close, u32, fd)
4786 {
4787 	/* When bpf program calls this helper there should not be
4788 	 * an fdget() without matching completed fdput().
4789 	 * This helper is allowed in the following callchain only:
4790 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
4791 	 */
4792 	return close_fd(fd);
4793 }
4794 
4795 static const struct bpf_func_proto bpf_sys_close_proto = {
4796 	.func		= bpf_sys_close,
4797 	.gpl_only	= false,
4798 	.ret_type	= RET_INTEGER,
4799 	.arg1_type	= ARG_ANYTHING,
4800 };
4801 
4802 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)4803 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
4804 {
4805 	switch (func_id) {
4806 	case BPF_FUNC_sys_bpf:
4807 		return !perfmon_capable() ? NULL : &bpf_sys_bpf_proto;
4808 	case BPF_FUNC_btf_find_by_name_kind:
4809 		return &bpf_btf_find_by_name_kind_proto;
4810 	case BPF_FUNC_sys_close:
4811 		return &bpf_sys_close_proto;
4812 	default:
4813 		return tracing_prog_func_proto(func_id, prog);
4814 	}
4815 }
4816 
4817 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
4818 	.get_func_proto  = syscall_prog_func_proto,
4819 	.is_valid_access = syscall_prog_is_valid_access,
4820 };
4821 
4822 const struct bpf_prog_ops bpf_syscall_prog_ops = {
4823 	.test_run = bpf_prog_test_run_syscall,
4824 };
4825