xref: /linux/kernel/bpf/syscall.c (revision 319fc77f8f45a1b3dba15b0cc1a869778fd222f7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3  */
4 #include <linux/bpf.h>
5 #include <linux/bpf-cgroup.h>
6 #include <linux/bpf_trace.h>
7 #include <linux/bpf_lirc.h>
8 #include <linux/bpf_verifier.h>
9 #include <linux/bsearch.h>
10 #include <linux/btf.h>
11 #include <linux/syscalls.h>
12 #include <linux/slab.h>
13 #include <linux/sched/signal.h>
14 #include <linux/vmalloc.h>
15 #include <linux/mmzone.h>
16 #include <linux/anon_inodes.h>
17 #include <linux/fdtable.h>
18 #include <linux/file.h>
19 #include <linux/fs.h>
20 #include <linux/license.h>
21 #include <linux/filter.h>
22 #include <linux/kernel.h>
23 #include <linux/idr.h>
24 #include <linux/cred.h>
25 #include <linux/timekeeping.h>
26 #include <linux/ctype.h>
27 #include <linux/nospec.h>
28 #include <linux/audit.h>
29 #include <uapi/linux/btf.h>
30 #include <linux/pgtable.h>
31 #include <linux/bpf_lsm.h>
32 #include <linux/poll.h>
33 #include <linux/sort.h>
34 #include <linux/bpf-netns.h>
35 #include <linux/rcupdate_trace.h>
36 #include <linux/memcontrol.h>
37 #include <linux/trace_events.h>
38 #include <linux/tracepoint.h>
39 
40 #include <net/netfilter/nf_bpf_link.h>
41 #include <net/netkit.h>
42 #include <net/tcx.h>
43 
44 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
45 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
46 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
47 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
48 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
49 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
50 			IS_FD_HASH(map))
51 
52 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
53 
54 DEFINE_PER_CPU(int, bpf_prog_active);
55 static DEFINE_IDR(prog_idr);
56 static DEFINE_SPINLOCK(prog_idr_lock);
57 static DEFINE_IDR(map_idr);
58 static DEFINE_SPINLOCK(map_idr_lock);
59 static DEFINE_IDR(link_idr);
60 static DEFINE_SPINLOCK(link_idr_lock);
61 
62 int sysctl_unprivileged_bpf_disabled __read_mostly =
63 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
64 
65 static const struct bpf_map_ops * const bpf_map_types[] = {
66 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
67 #define BPF_MAP_TYPE(_id, _ops) \
68 	[_id] = &_ops,
69 #define BPF_LINK_TYPE(_id, _name)
70 #include <linux/bpf_types.h>
71 #undef BPF_PROG_TYPE
72 #undef BPF_MAP_TYPE
73 #undef BPF_LINK_TYPE
74 };
75 
76 /*
77  * If we're handed a bigger struct than we know of, ensure all the unknown bits
78  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
79  * we don't know about yet.
80  *
81  * There is a ToCToU between this function call and the following
82  * copy_from_user() call. However, this is not a concern since this function is
83  * meant to be a future-proofing of bits.
84  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)85 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
86 			     size_t expected_size,
87 			     size_t actual_size)
88 {
89 	int res;
90 
91 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
92 		return -E2BIG;
93 
94 	if (actual_size <= expected_size)
95 		return 0;
96 
97 	if (uaddr.is_kernel)
98 		res = memchr_inv(uaddr.kernel + expected_size, 0,
99 				 actual_size - expected_size) == NULL;
100 	else
101 		res = check_zeroed_user(uaddr.user + expected_size,
102 					actual_size - expected_size);
103 	if (res < 0)
104 		return res;
105 	return res ? 0 : -E2BIG;
106 }
107 
108 const struct bpf_map_ops bpf_map_offload_ops = {
109 	.map_meta_equal = bpf_map_meta_equal,
110 	.map_alloc = bpf_map_offload_map_alloc,
111 	.map_free = bpf_map_offload_map_free,
112 	.map_check_btf = map_check_no_btf,
113 	.map_mem_usage = bpf_map_offload_map_mem_usage,
114 };
115 
bpf_map_write_active_inc(struct bpf_map * map)116 static void bpf_map_write_active_inc(struct bpf_map *map)
117 {
118 	atomic64_inc(&map->writecnt);
119 }
120 
bpf_map_write_active_dec(struct bpf_map * map)121 static void bpf_map_write_active_dec(struct bpf_map *map)
122 {
123 	atomic64_dec(&map->writecnt);
124 }
125 
bpf_map_write_active(const struct bpf_map * map)126 bool bpf_map_write_active(const struct bpf_map *map)
127 {
128 	return atomic64_read(&map->writecnt) != 0;
129 }
130 
bpf_map_value_size(const struct bpf_map * map)131 static u32 bpf_map_value_size(const struct bpf_map *map)
132 {
133 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
134 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
135 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
136 	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
137 		return round_up(map->value_size, 8) * num_possible_cpus();
138 	else if (IS_FD_MAP(map))
139 		return sizeof(u32);
140 	else
141 		return  map->value_size;
142 }
143 
maybe_wait_bpf_programs(struct bpf_map * map)144 static void maybe_wait_bpf_programs(struct bpf_map *map)
145 {
146 	/* Wait for any running non-sleepable BPF programs to complete so that
147 	 * userspace, when we return to it, knows that all non-sleepable
148 	 * programs that could be running use the new map value. For sleepable
149 	 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
150 	 * for the completions of these programs, but considering the waiting
151 	 * time can be very long and userspace may think it will hang forever,
152 	 * so don't handle sleepable BPF programs now.
153 	 */
154 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
155 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
156 		synchronize_rcu();
157 }
158 
unpin_uptr_kaddr(void * kaddr)159 static void unpin_uptr_kaddr(void *kaddr)
160 {
161 	if (kaddr)
162 		unpin_user_page(virt_to_page(kaddr));
163 }
164 
__bpf_obj_unpin_uptrs(struct btf_record * rec,u32 cnt,void * obj)165 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj)
166 {
167 	const struct btf_field *field;
168 	void **uptr_addr;
169 	int i;
170 
171 	for (i = 0, field = rec->fields; i < cnt; i++, field++) {
172 		if (field->type != BPF_UPTR)
173 			continue;
174 
175 		uptr_addr = obj + field->offset;
176 		unpin_uptr_kaddr(*uptr_addr);
177 	}
178 }
179 
bpf_obj_unpin_uptrs(struct btf_record * rec,void * obj)180 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj)
181 {
182 	if (!btf_record_has_field(rec, BPF_UPTR))
183 		return;
184 
185 	__bpf_obj_unpin_uptrs(rec, rec->cnt, obj);
186 }
187 
bpf_obj_pin_uptrs(struct btf_record * rec,void * obj)188 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj)
189 {
190 	const struct btf_field *field;
191 	const struct btf_type *t;
192 	unsigned long start, end;
193 	struct page *page;
194 	void **uptr_addr;
195 	int i, err;
196 
197 	if (!btf_record_has_field(rec, BPF_UPTR))
198 		return 0;
199 
200 	for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) {
201 		if (field->type != BPF_UPTR)
202 			continue;
203 
204 		uptr_addr = obj + field->offset;
205 		start = *(unsigned long *)uptr_addr;
206 		if (!start)
207 			continue;
208 
209 		t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id);
210 		/* t->size was checked for zero before */
211 		if (check_add_overflow(start, t->size - 1, &end)) {
212 			err = -EFAULT;
213 			goto unpin_all;
214 		}
215 
216 		/* The uptr's struct cannot span across two pages */
217 		if ((start & PAGE_MASK) != (end & PAGE_MASK)) {
218 			err = -EOPNOTSUPP;
219 			goto unpin_all;
220 		}
221 
222 		err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page);
223 		if (err != 1)
224 			goto unpin_all;
225 
226 		if (PageHighMem(page)) {
227 			err = -EOPNOTSUPP;
228 			unpin_user_page(page);
229 			goto unpin_all;
230 		}
231 
232 		*uptr_addr = page_address(page) + offset_in_page(start);
233 	}
234 
235 	return 0;
236 
237 unpin_all:
238 	__bpf_obj_unpin_uptrs(rec, i, obj);
239 	return err;
240 }
241 
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)242 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
243 				void *key, void *value, __u64 flags)
244 {
245 	int err;
246 
247 	/* Need to create a kthread, thus must support schedule */
248 	if (bpf_map_is_offloaded(map)) {
249 		return bpf_map_offload_update_elem(map, key, value, flags);
250 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
251 		   map->map_type == BPF_MAP_TYPE_ARENA ||
252 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
253 		return map->ops->map_update_elem(map, key, value, flags);
254 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
255 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
256 		return sock_map_update_elem_sys(map, key, value, flags);
257 	} else if (IS_FD_PROG_ARRAY(map)) {
258 		return bpf_fd_array_map_update_elem(map, map_file, key, value,
259 						    flags);
260 	}
261 
262 	bpf_disable_instrumentation();
263 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
264 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
265 		err = bpf_percpu_hash_update(map, key, value, flags);
266 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
267 		err = bpf_percpu_array_update(map, key, value, flags);
268 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
269 		err = bpf_percpu_cgroup_storage_update(map, key, value,
270 						       flags);
271 	} else if (IS_FD_ARRAY(map)) {
272 		err = bpf_fd_array_map_update_elem(map, map_file, key, value,
273 						   flags);
274 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
275 		err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
276 						  flags);
277 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
278 		/* rcu_read_lock() is not needed */
279 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
280 							 flags);
281 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
282 		   map->map_type == BPF_MAP_TYPE_STACK ||
283 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
284 		err = map->ops->map_push_elem(map, value, flags);
285 	} else {
286 		err = bpf_obj_pin_uptrs(map->record, value);
287 		if (!err) {
288 			rcu_read_lock();
289 			err = map->ops->map_update_elem(map, key, value, flags);
290 			rcu_read_unlock();
291 			if (err)
292 				bpf_obj_unpin_uptrs(map->record, value);
293 		}
294 	}
295 	bpf_enable_instrumentation();
296 
297 	return err;
298 }
299 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)300 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
301 			      __u64 flags)
302 {
303 	void *ptr;
304 	int err;
305 
306 	if (bpf_map_is_offloaded(map))
307 		return bpf_map_offload_lookup_elem(map, key, value);
308 
309 	bpf_disable_instrumentation();
310 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
311 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
312 		err = bpf_percpu_hash_copy(map, key, value);
313 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
314 		err = bpf_percpu_array_copy(map, key, value);
315 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
316 		err = bpf_percpu_cgroup_storage_copy(map, key, value);
317 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
318 		err = bpf_stackmap_copy(map, key, value);
319 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
320 		err = bpf_fd_array_map_lookup_elem(map, key, value);
321 	} else if (IS_FD_HASH(map)) {
322 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
323 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
324 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
325 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
326 		   map->map_type == BPF_MAP_TYPE_STACK ||
327 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
328 		err = map->ops->map_peek_elem(map, value);
329 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
330 		/* struct_ops map requires directly updating "value" */
331 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
332 	} else {
333 		rcu_read_lock();
334 		if (map->ops->map_lookup_elem_sys_only)
335 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
336 		else
337 			ptr = map->ops->map_lookup_elem(map, key);
338 		if (IS_ERR(ptr)) {
339 			err = PTR_ERR(ptr);
340 		} else if (!ptr) {
341 			err = -ENOENT;
342 		} else {
343 			err = 0;
344 			if (flags & BPF_F_LOCK)
345 				/* lock 'ptr' and copy everything but lock */
346 				copy_map_value_locked(map, value, ptr, true);
347 			else
348 				copy_map_value(map, value, ptr);
349 			/* mask lock and timer, since value wasn't zero inited */
350 			check_and_init_map_value(map, value);
351 		}
352 		rcu_read_unlock();
353 	}
354 
355 	bpf_enable_instrumentation();
356 
357 	return err;
358 }
359 
360 /* Please, do not use this function outside from the map creation path
361  * (e.g. in map update path) without taking care of setting the active
362  * memory cgroup (see at bpf_map_kmalloc_node() for example).
363  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)364 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
365 {
366 	/* We really just want to fail instead of triggering OOM killer
367 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
368 	 * which is used for lower order allocation requests.
369 	 *
370 	 * It has been observed that higher order allocation requests done by
371 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
372 	 * to reclaim memory from the page cache, thus we set
373 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
374 	 */
375 
376 	gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
377 	unsigned int flags = 0;
378 	unsigned long align = 1;
379 	void *area;
380 
381 	if (size >= SIZE_MAX)
382 		return NULL;
383 
384 	/* kmalloc()'ed memory can't be mmap()'ed */
385 	if (mmapable) {
386 		BUG_ON(!PAGE_ALIGNED(size));
387 		align = SHMLBA;
388 		flags = VM_USERMAP;
389 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
390 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
391 				    numa_node);
392 		if (area != NULL)
393 			return area;
394 	}
395 
396 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
397 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
398 			flags, numa_node, __builtin_return_address(0));
399 }
400 
bpf_map_area_alloc(u64 size,int numa_node)401 void *bpf_map_area_alloc(u64 size, int numa_node)
402 {
403 	return __bpf_map_area_alloc(size, numa_node, false);
404 }
405 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)406 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
407 {
408 	return __bpf_map_area_alloc(size, numa_node, true);
409 }
410 
bpf_map_area_free(void * area)411 void bpf_map_area_free(void *area)
412 {
413 	kvfree(area);
414 }
415 
bpf_map_flags_retain_permanent(u32 flags)416 static u32 bpf_map_flags_retain_permanent(u32 flags)
417 {
418 	/* Some map creation flags are not tied to the map object but
419 	 * rather to the map fd instead, so they have no meaning upon
420 	 * map object inspection since multiple file descriptors with
421 	 * different (access) properties can exist here. Thus, given
422 	 * this has zero meaning for the map itself, lets clear these
423 	 * from here.
424 	 */
425 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
426 }
427 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)428 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
429 {
430 	map->map_type = attr->map_type;
431 	map->key_size = attr->key_size;
432 	map->value_size = attr->value_size;
433 	map->max_entries = attr->max_entries;
434 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
435 	map->numa_node = bpf_map_attr_numa_node(attr);
436 	map->map_extra = attr->map_extra;
437 }
438 
bpf_map_alloc_id(struct bpf_map * map)439 static int bpf_map_alloc_id(struct bpf_map *map)
440 {
441 	int id;
442 
443 	idr_preload(GFP_KERNEL);
444 	spin_lock_bh(&map_idr_lock);
445 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
446 	if (id > 0)
447 		map->id = id;
448 	spin_unlock_bh(&map_idr_lock);
449 	idr_preload_end();
450 
451 	if (WARN_ON_ONCE(!id))
452 		return -ENOSPC;
453 
454 	return id > 0 ? 0 : id;
455 }
456 
bpf_map_free_id(struct bpf_map * map)457 void bpf_map_free_id(struct bpf_map *map)
458 {
459 	unsigned long flags;
460 
461 	/* Offloaded maps are removed from the IDR store when their device
462 	 * disappears - even if someone holds an fd to them they are unusable,
463 	 * the memory is gone, all ops will fail; they are simply waiting for
464 	 * refcnt to drop to be freed.
465 	 */
466 	if (!map->id)
467 		return;
468 
469 	spin_lock_irqsave(&map_idr_lock, flags);
470 
471 	idr_remove(&map_idr, map->id);
472 	map->id = 0;
473 
474 	spin_unlock_irqrestore(&map_idr_lock, flags);
475 }
476 
477 #ifdef CONFIG_MEMCG
bpf_map_save_memcg(struct bpf_map * map)478 static void bpf_map_save_memcg(struct bpf_map *map)
479 {
480 	/* Currently if a map is created by a process belonging to the root
481 	 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
482 	 * So we have to check map->objcg for being NULL each time it's
483 	 * being used.
484 	 */
485 	if (memcg_bpf_enabled())
486 		map->objcg = get_obj_cgroup_from_current();
487 }
488 
bpf_map_release_memcg(struct bpf_map * map)489 static void bpf_map_release_memcg(struct bpf_map *map)
490 {
491 	if (map->objcg)
492 		obj_cgroup_put(map->objcg);
493 }
494 
bpf_map_get_memcg(const struct bpf_map * map)495 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
496 {
497 	if (map->objcg)
498 		return get_mem_cgroup_from_objcg(map->objcg);
499 
500 	return root_mem_cgroup;
501 }
502 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)503 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
504 			   int node)
505 {
506 	struct mem_cgroup *memcg, *old_memcg;
507 	void *ptr;
508 
509 	memcg = bpf_map_get_memcg(map);
510 	old_memcg = set_active_memcg(memcg);
511 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
512 	set_active_memcg(old_memcg);
513 	mem_cgroup_put(memcg);
514 
515 	return ptr;
516 }
517 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)518 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
519 {
520 	struct mem_cgroup *memcg, *old_memcg;
521 	void *ptr;
522 
523 	memcg = bpf_map_get_memcg(map);
524 	old_memcg = set_active_memcg(memcg);
525 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
526 	set_active_memcg(old_memcg);
527 	mem_cgroup_put(memcg);
528 
529 	return ptr;
530 }
531 
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)532 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
533 		       gfp_t flags)
534 {
535 	struct mem_cgroup *memcg, *old_memcg;
536 	void *ptr;
537 
538 	memcg = bpf_map_get_memcg(map);
539 	old_memcg = set_active_memcg(memcg);
540 	ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
541 	set_active_memcg(old_memcg);
542 	mem_cgroup_put(memcg);
543 
544 	return ptr;
545 }
546 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)547 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
548 				    size_t align, gfp_t flags)
549 {
550 	struct mem_cgroup *memcg, *old_memcg;
551 	void __percpu *ptr;
552 
553 	memcg = bpf_map_get_memcg(map);
554 	old_memcg = set_active_memcg(memcg);
555 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
556 	set_active_memcg(old_memcg);
557 	mem_cgroup_put(memcg);
558 
559 	return ptr;
560 }
561 
562 #else
bpf_map_save_memcg(struct bpf_map * map)563 static void bpf_map_save_memcg(struct bpf_map *map)
564 {
565 }
566 
bpf_map_release_memcg(struct bpf_map * map)567 static void bpf_map_release_memcg(struct bpf_map *map)
568 {
569 }
570 #endif
571 
bpf_map_alloc_pages(const struct bpf_map * map,gfp_t gfp,int nid,unsigned long nr_pages,struct page ** pages)572 int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid,
573 			unsigned long nr_pages, struct page **pages)
574 {
575 	unsigned long i, j;
576 	struct page *pg;
577 	int ret = 0;
578 #ifdef CONFIG_MEMCG
579 	struct mem_cgroup *memcg, *old_memcg;
580 
581 	memcg = bpf_map_get_memcg(map);
582 	old_memcg = set_active_memcg(memcg);
583 #endif
584 	for (i = 0; i < nr_pages; i++) {
585 		pg = alloc_pages_node(nid, gfp | __GFP_ACCOUNT, 0);
586 
587 		if (pg) {
588 			pages[i] = pg;
589 			continue;
590 		}
591 		for (j = 0; j < i; j++)
592 			__free_page(pages[j]);
593 		ret = -ENOMEM;
594 		break;
595 	}
596 
597 #ifdef CONFIG_MEMCG
598 	set_active_memcg(old_memcg);
599 	mem_cgroup_put(memcg);
600 #endif
601 	return ret;
602 }
603 
604 
btf_field_cmp(const void * a,const void * b)605 static int btf_field_cmp(const void *a, const void *b)
606 {
607 	const struct btf_field *f1 = a, *f2 = b;
608 
609 	if (f1->offset < f2->offset)
610 		return -1;
611 	else if (f1->offset > f2->offset)
612 		return 1;
613 	return 0;
614 }
615 
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)616 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
617 				  u32 field_mask)
618 {
619 	struct btf_field *field;
620 
621 	if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
622 		return NULL;
623 	field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
624 	if (!field || !(field->type & field_mask))
625 		return NULL;
626 	return field;
627 }
628 
btf_record_free(struct btf_record * rec)629 void btf_record_free(struct btf_record *rec)
630 {
631 	int i;
632 
633 	if (IS_ERR_OR_NULL(rec))
634 		return;
635 	for (i = 0; i < rec->cnt; i++) {
636 		switch (rec->fields[i].type) {
637 		case BPF_KPTR_UNREF:
638 		case BPF_KPTR_REF:
639 		case BPF_KPTR_PERCPU:
640 		case BPF_UPTR:
641 			if (rec->fields[i].kptr.module)
642 				module_put(rec->fields[i].kptr.module);
643 			if (btf_is_kernel(rec->fields[i].kptr.btf))
644 				btf_put(rec->fields[i].kptr.btf);
645 			break;
646 		case BPF_LIST_HEAD:
647 		case BPF_LIST_NODE:
648 		case BPF_RB_ROOT:
649 		case BPF_RB_NODE:
650 		case BPF_SPIN_LOCK:
651 		case BPF_TIMER:
652 		case BPF_REFCOUNT:
653 		case BPF_WORKQUEUE:
654 			/* Nothing to release */
655 			break;
656 		default:
657 			WARN_ON_ONCE(1);
658 			continue;
659 		}
660 	}
661 	kfree(rec);
662 }
663 
bpf_map_free_record(struct bpf_map * map)664 void bpf_map_free_record(struct bpf_map *map)
665 {
666 	btf_record_free(map->record);
667 	map->record = NULL;
668 }
669 
btf_record_dup(const struct btf_record * rec)670 struct btf_record *btf_record_dup(const struct btf_record *rec)
671 {
672 	const struct btf_field *fields;
673 	struct btf_record *new_rec;
674 	int ret, size, i;
675 
676 	if (IS_ERR_OR_NULL(rec))
677 		return NULL;
678 	size = offsetof(struct btf_record, fields[rec->cnt]);
679 	new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
680 	if (!new_rec)
681 		return ERR_PTR(-ENOMEM);
682 	/* Do a deep copy of the btf_record */
683 	fields = rec->fields;
684 	new_rec->cnt = 0;
685 	for (i = 0; i < rec->cnt; i++) {
686 		switch (fields[i].type) {
687 		case BPF_KPTR_UNREF:
688 		case BPF_KPTR_REF:
689 		case BPF_KPTR_PERCPU:
690 		case BPF_UPTR:
691 			if (btf_is_kernel(fields[i].kptr.btf))
692 				btf_get(fields[i].kptr.btf);
693 			if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
694 				ret = -ENXIO;
695 				goto free;
696 			}
697 			break;
698 		case BPF_LIST_HEAD:
699 		case BPF_LIST_NODE:
700 		case BPF_RB_ROOT:
701 		case BPF_RB_NODE:
702 		case BPF_SPIN_LOCK:
703 		case BPF_TIMER:
704 		case BPF_REFCOUNT:
705 		case BPF_WORKQUEUE:
706 			/* Nothing to acquire */
707 			break;
708 		default:
709 			ret = -EFAULT;
710 			WARN_ON_ONCE(1);
711 			goto free;
712 		}
713 		new_rec->cnt++;
714 	}
715 	return new_rec;
716 free:
717 	btf_record_free(new_rec);
718 	return ERR_PTR(ret);
719 }
720 
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)721 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
722 {
723 	bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
724 	int size;
725 
726 	if (!a_has_fields && !b_has_fields)
727 		return true;
728 	if (a_has_fields != b_has_fields)
729 		return false;
730 	if (rec_a->cnt != rec_b->cnt)
731 		return false;
732 	size = offsetof(struct btf_record, fields[rec_a->cnt]);
733 	/* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
734 	 * members are zeroed out. So memcmp is safe to do without worrying
735 	 * about padding/unused fields.
736 	 *
737 	 * While spin_lock, timer, and kptr have no relation to map BTF,
738 	 * list_head metadata is specific to map BTF, the btf and value_rec
739 	 * members in particular. btf is the map BTF, while value_rec points to
740 	 * btf_record in that map BTF.
741 	 *
742 	 * So while by default, we don't rely on the map BTF (which the records
743 	 * were parsed from) matching for both records, which is not backwards
744 	 * compatible, in case list_head is part of it, we implicitly rely on
745 	 * that by way of depending on memcmp succeeding for it.
746 	 */
747 	return !memcmp(rec_a, rec_b, size);
748 }
749 
bpf_obj_free_timer(const struct btf_record * rec,void * obj)750 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
751 {
752 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
753 		return;
754 	bpf_timer_cancel_and_free(obj + rec->timer_off);
755 }
756 
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)757 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
758 {
759 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
760 		return;
761 	bpf_wq_cancel_and_free(obj + rec->wq_off);
762 }
763 
bpf_obj_free_fields(const struct btf_record * rec,void * obj)764 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
765 {
766 	const struct btf_field *fields;
767 	int i;
768 
769 	if (IS_ERR_OR_NULL(rec))
770 		return;
771 	fields = rec->fields;
772 	for (i = 0; i < rec->cnt; i++) {
773 		struct btf_struct_meta *pointee_struct_meta;
774 		const struct btf_field *field = &fields[i];
775 		void *field_ptr = obj + field->offset;
776 		void *xchgd_field;
777 
778 		switch (fields[i].type) {
779 		case BPF_SPIN_LOCK:
780 			break;
781 		case BPF_TIMER:
782 			bpf_timer_cancel_and_free(field_ptr);
783 			break;
784 		case BPF_WORKQUEUE:
785 			bpf_wq_cancel_and_free(field_ptr);
786 			break;
787 		case BPF_KPTR_UNREF:
788 			WRITE_ONCE(*(u64 *)field_ptr, 0);
789 			break;
790 		case BPF_KPTR_REF:
791 		case BPF_KPTR_PERCPU:
792 			xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
793 			if (!xchgd_field)
794 				break;
795 
796 			if (!btf_is_kernel(field->kptr.btf)) {
797 				pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
798 									   field->kptr.btf_id);
799 				__bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
800 								 pointee_struct_meta->record : NULL,
801 								 fields[i].type == BPF_KPTR_PERCPU);
802 			} else {
803 				field->kptr.dtor(xchgd_field);
804 			}
805 			break;
806 		case BPF_UPTR:
807 			/* The caller ensured that no one is using the uptr */
808 			unpin_uptr_kaddr(*(void **)field_ptr);
809 			break;
810 		case BPF_LIST_HEAD:
811 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
812 				continue;
813 			bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
814 			break;
815 		case BPF_RB_ROOT:
816 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
817 				continue;
818 			bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
819 			break;
820 		case BPF_LIST_NODE:
821 		case BPF_RB_NODE:
822 		case BPF_REFCOUNT:
823 			break;
824 		default:
825 			WARN_ON_ONCE(1);
826 			continue;
827 		}
828 	}
829 }
830 
bpf_map_free(struct bpf_map * map)831 static void bpf_map_free(struct bpf_map *map)
832 {
833 	struct btf_record *rec = map->record;
834 	struct btf *btf = map->btf;
835 
836 	/* implementation dependent freeing. Disabling migration to simplify
837 	 * the free of values or special fields allocated from bpf memory
838 	 * allocator.
839 	 */
840 	migrate_disable();
841 	map->ops->map_free(map);
842 	migrate_enable();
843 
844 	/* Delay freeing of btf_record for maps, as map_free
845 	 * callback usually needs access to them. It is better to do it here
846 	 * than require each callback to do the free itself manually.
847 	 *
848 	 * Note that the btf_record stashed in map->inner_map_meta->record was
849 	 * already freed using the map_free callback for map in map case which
850 	 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
851 	 * template bpf_map struct used during verification.
852 	 */
853 	btf_record_free(rec);
854 	/* Delay freeing of btf for maps, as map_free callback may need
855 	 * struct_meta info which will be freed with btf_put().
856 	 */
857 	btf_put(btf);
858 }
859 
860 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)861 static void bpf_map_free_deferred(struct work_struct *work)
862 {
863 	struct bpf_map *map = container_of(work, struct bpf_map, work);
864 
865 	security_bpf_map_free(map);
866 	bpf_map_release_memcg(map);
867 	bpf_map_free(map);
868 }
869 
bpf_map_put_uref(struct bpf_map * map)870 static void bpf_map_put_uref(struct bpf_map *map)
871 {
872 	if (atomic64_dec_and_test(&map->usercnt)) {
873 		if (map->ops->map_release_uref)
874 			map->ops->map_release_uref(map);
875 	}
876 }
877 
bpf_map_free_in_work(struct bpf_map * map)878 static void bpf_map_free_in_work(struct bpf_map *map)
879 {
880 	INIT_WORK(&map->work, bpf_map_free_deferred);
881 	/* Avoid spawning kworkers, since they all might contend
882 	 * for the same mutex like slab_mutex.
883 	 */
884 	queue_work(system_unbound_wq, &map->work);
885 }
886 
bpf_map_free_rcu_gp(struct rcu_head * rcu)887 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
888 {
889 	bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
890 }
891 
bpf_map_free_mult_rcu_gp(struct rcu_head * rcu)892 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
893 {
894 	if (rcu_trace_implies_rcu_gp())
895 		bpf_map_free_rcu_gp(rcu);
896 	else
897 		call_rcu(rcu, bpf_map_free_rcu_gp);
898 }
899 
900 /* decrement map refcnt and schedule it for freeing via workqueue
901  * (underlying map implementation ops->map_free() might sleep)
902  */
bpf_map_put(struct bpf_map * map)903 void bpf_map_put(struct bpf_map *map)
904 {
905 	if (atomic64_dec_and_test(&map->refcnt)) {
906 		/* bpf_map_free_id() must be called first */
907 		bpf_map_free_id(map);
908 
909 		WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
910 		if (READ_ONCE(map->free_after_mult_rcu_gp))
911 			call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
912 		else if (READ_ONCE(map->free_after_rcu_gp))
913 			call_rcu(&map->rcu, bpf_map_free_rcu_gp);
914 		else
915 			bpf_map_free_in_work(map);
916 	}
917 }
918 EXPORT_SYMBOL_GPL(bpf_map_put);
919 
bpf_map_put_with_uref(struct bpf_map * map)920 void bpf_map_put_with_uref(struct bpf_map *map)
921 {
922 	bpf_map_put_uref(map);
923 	bpf_map_put(map);
924 }
925 
bpf_map_release(struct inode * inode,struct file * filp)926 static int bpf_map_release(struct inode *inode, struct file *filp)
927 {
928 	struct bpf_map *map = filp->private_data;
929 
930 	if (map->ops->map_release)
931 		map->ops->map_release(map, filp);
932 
933 	bpf_map_put_with_uref(map);
934 	return 0;
935 }
936 
map_get_sys_perms(struct bpf_map * map,struct fd f)937 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
938 {
939 	fmode_t mode = fd_file(f)->f_mode;
940 
941 	/* Our file permissions may have been overridden by global
942 	 * map permissions facing syscall side.
943 	 */
944 	if (READ_ONCE(map->frozen))
945 		mode &= ~FMODE_CAN_WRITE;
946 	return mode;
947 }
948 
949 #ifdef CONFIG_PROC_FS
950 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)951 static u64 bpf_map_memory_usage(const struct bpf_map *map)
952 {
953 	return map->ops->map_mem_usage(map);
954 }
955 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)956 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
957 {
958 	struct bpf_map *map = filp->private_data;
959 	u32 type = 0, jited = 0;
960 
961 	if (map_type_contains_progs(map)) {
962 		spin_lock(&map->owner.lock);
963 		type  = map->owner.type;
964 		jited = map->owner.jited;
965 		spin_unlock(&map->owner.lock);
966 	}
967 
968 	seq_printf(m,
969 		   "map_type:\t%u\n"
970 		   "key_size:\t%u\n"
971 		   "value_size:\t%u\n"
972 		   "max_entries:\t%u\n"
973 		   "map_flags:\t%#x\n"
974 		   "map_extra:\t%#llx\n"
975 		   "memlock:\t%llu\n"
976 		   "map_id:\t%u\n"
977 		   "frozen:\t%u\n",
978 		   map->map_type,
979 		   map->key_size,
980 		   map->value_size,
981 		   map->max_entries,
982 		   map->map_flags,
983 		   (unsigned long long)map->map_extra,
984 		   bpf_map_memory_usage(map),
985 		   map->id,
986 		   READ_ONCE(map->frozen));
987 	if (type) {
988 		seq_printf(m, "owner_prog_type:\t%u\n", type);
989 		seq_printf(m, "owner_jited:\t%u\n", jited);
990 	}
991 }
992 #endif
993 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)994 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
995 			      loff_t *ppos)
996 {
997 	/* We need this handler such that alloc_file() enables
998 	 * f_mode with FMODE_CAN_READ.
999 	 */
1000 	return -EINVAL;
1001 }
1002 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1003 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1004 			       size_t siz, loff_t *ppos)
1005 {
1006 	/* We need this handler such that alloc_file() enables
1007 	 * f_mode with FMODE_CAN_WRITE.
1008 	 */
1009 	return -EINVAL;
1010 }
1011 
1012 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1013 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1014 {
1015 	struct bpf_map *map = vma->vm_file->private_data;
1016 
1017 	if (vma->vm_flags & VM_MAYWRITE)
1018 		bpf_map_write_active_inc(map);
1019 }
1020 
1021 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1022 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1023 {
1024 	struct bpf_map *map = vma->vm_file->private_data;
1025 
1026 	if (vma->vm_flags & VM_MAYWRITE)
1027 		bpf_map_write_active_dec(map);
1028 }
1029 
1030 static const struct vm_operations_struct bpf_map_default_vmops = {
1031 	.open		= bpf_map_mmap_open,
1032 	.close		= bpf_map_mmap_close,
1033 };
1034 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1035 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1036 {
1037 	struct bpf_map *map = filp->private_data;
1038 	int err = 0;
1039 
1040 	if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1041 		return -ENOTSUPP;
1042 
1043 	if (!(vma->vm_flags & VM_SHARED))
1044 		return -EINVAL;
1045 
1046 	mutex_lock(&map->freeze_mutex);
1047 
1048 	if (vma->vm_flags & VM_WRITE) {
1049 		if (map->frozen) {
1050 			err = -EPERM;
1051 			goto out;
1052 		}
1053 		/* map is meant to be read-only, so do not allow mapping as
1054 		 * writable, because it's possible to leak a writable page
1055 		 * reference and allows user-space to still modify it after
1056 		 * freezing, while verifier will assume contents do not change
1057 		 */
1058 		if (map->map_flags & BPF_F_RDONLY_PROG) {
1059 			err = -EACCES;
1060 			goto out;
1061 		}
1062 		bpf_map_write_active_inc(map);
1063 	}
1064 out:
1065 	mutex_unlock(&map->freeze_mutex);
1066 	if (err)
1067 		return err;
1068 
1069 	/* set default open/close callbacks */
1070 	vma->vm_ops = &bpf_map_default_vmops;
1071 	vma->vm_private_data = map;
1072 	vm_flags_clear(vma, VM_MAYEXEC);
1073 	/* If mapping is read-only, then disallow potentially re-mapping with
1074 	 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1075 	 * means that as far as BPF map's memory-mapped VMAs are concerned,
1076 	 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1077 	 * both should be set, so we can forget about VM_MAYWRITE and always
1078 	 * check just VM_WRITE
1079 	 */
1080 	if (!(vma->vm_flags & VM_WRITE))
1081 		vm_flags_clear(vma, VM_MAYWRITE);
1082 
1083 	err = map->ops->map_mmap(map, vma);
1084 	if (err) {
1085 		if (vma->vm_flags & VM_WRITE)
1086 			bpf_map_write_active_dec(map);
1087 	}
1088 
1089 	return err;
1090 }
1091 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1092 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1093 {
1094 	struct bpf_map *map = filp->private_data;
1095 
1096 	if (map->ops->map_poll)
1097 		return map->ops->map_poll(map, filp, pts);
1098 
1099 	return EPOLLERR;
1100 }
1101 
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1102 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1103 					   unsigned long len, unsigned long pgoff,
1104 					   unsigned long flags)
1105 {
1106 	struct bpf_map *map = filp->private_data;
1107 
1108 	if (map->ops->map_get_unmapped_area)
1109 		return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1110 #ifdef CONFIG_MMU
1111 	return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
1112 #else
1113 	return addr;
1114 #endif
1115 }
1116 
1117 const struct file_operations bpf_map_fops = {
1118 #ifdef CONFIG_PROC_FS
1119 	.show_fdinfo	= bpf_map_show_fdinfo,
1120 #endif
1121 	.release	= bpf_map_release,
1122 	.read		= bpf_dummy_read,
1123 	.write		= bpf_dummy_write,
1124 	.mmap		= bpf_map_mmap,
1125 	.poll		= bpf_map_poll,
1126 	.get_unmapped_area = bpf_get_unmapped_area,
1127 };
1128 
bpf_map_new_fd(struct bpf_map * map,int flags)1129 int bpf_map_new_fd(struct bpf_map *map, int flags)
1130 {
1131 	int ret;
1132 
1133 	ret = security_bpf_map(map, OPEN_FMODE(flags));
1134 	if (ret < 0)
1135 		return ret;
1136 
1137 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1138 				flags | O_CLOEXEC);
1139 }
1140 
bpf_get_file_flag(int flags)1141 int bpf_get_file_flag(int flags)
1142 {
1143 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1144 		return -EINVAL;
1145 	if (flags & BPF_F_RDONLY)
1146 		return O_RDONLY;
1147 	if (flags & BPF_F_WRONLY)
1148 		return O_WRONLY;
1149 	return O_RDWR;
1150 }
1151 
1152 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1153 #define CHECK_ATTR(CMD) \
1154 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1155 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
1156 		   sizeof(*attr) - \
1157 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1158 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
1159 
1160 /* dst and src must have at least "size" number of bytes.
1161  * Return strlen on success and < 0 on error.
1162  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1163 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1164 {
1165 	const char *end = src + size;
1166 	const char *orig_src = src;
1167 
1168 	memset(dst, 0, size);
1169 	/* Copy all isalnum(), '_' and '.' chars. */
1170 	while (src < end && *src) {
1171 		if (!isalnum(*src) &&
1172 		    *src != '_' && *src != '.')
1173 			return -EINVAL;
1174 		*dst++ = *src++;
1175 	}
1176 
1177 	/* No '\0' found in "size" number of bytes */
1178 	if (src == end)
1179 		return -EINVAL;
1180 
1181 	return src - orig_src;
1182 }
1183 
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)1184 int map_check_no_btf(const struct bpf_map *map,
1185 		     const struct btf *btf,
1186 		     const struct btf_type *key_type,
1187 		     const struct btf_type *value_type)
1188 {
1189 	return -ENOTSUPP;
1190 }
1191 
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1192 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1193 			 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1194 {
1195 	const struct btf_type *key_type, *value_type;
1196 	u32 key_size, value_size;
1197 	int ret = 0;
1198 
1199 	/* Some maps allow key to be unspecified. */
1200 	if (btf_key_id) {
1201 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1202 		if (!key_type || key_size != map->key_size)
1203 			return -EINVAL;
1204 	} else {
1205 		key_type = btf_type_by_id(btf, 0);
1206 		if (!map->ops->map_check_btf)
1207 			return -EINVAL;
1208 	}
1209 
1210 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1211 	if (!value_type || value_size != map->value_size)
1212 		return -EINVAL;
1213 
1214 	map->record = btf_parse_fields(btf, value_type,
1215 				       BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1216 				       BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR,
1217 				       map->value_size);
1218 	if (!IS_ERR_OR_NULL(map->record)) {
1219 		int i;
1220 
1221 		if (!bpf_token_capable(token, CAP_BPF)) {
1222 			ret = -EPERM;
1223 			goto free_map_tab;
1224 		}
1225 		if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1226 			ret = -EACCES;
1227 			goto free_map_tab;
1228 		}
1229 		for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1230 			switch (map->record->field_mask & (1 << i)) {
1231 			case 0:
1232 				continue;
1233 			case BPF_SPIN_LOCK:
1234 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1235 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1236 				    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1237 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1238 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1239 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1240 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1241 					ret = -EOPNOTSUPP;
1242 					goto free_map_tab;
1243 				}
1244 				break;
1245 			case BPF_TIMER:
1246 			case BPF_WORKQUEUE:
1247 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1248 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1249 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1250 					ret = -EOPNOTSUPP;
1251 					goto free_map_tab;
1252 				}
1253 				break;
1254 			case BPF_KPTR_UNREF:
1255 			case BPF_KPTR_REF:
1256 			case BPF_KPTR_PERCPU:
1257 			case BPF_REFCOUNT:
1258 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1259 				    map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1260 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1261 				    map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1262 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1263 				    map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1264 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1265 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1266 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1267 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1268 					ret = -EOPNOTSUPP;
1269 					goto free_map_tab;
1270 				}
1271 				break;
1272 			case BPF_UPTR:
1273 				if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1274 					ret = -EOPNOTSUPP;
1275 					goto free_map_tab;
1276 				}
1277 				break;
1278 			case BPF_LIST_HEAD:
1279 			case BPF_RB_ROOT:
1280 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1281 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1282 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1283 					ret = -EOPNOTSUPP;
1284 					goto free_map_tab;
1285 				}
1286 				break;
1287 			default:
1288 				/* Fail if map_type checks are missing for a field type */
1289 				ret = -EOPNOTSUPP;
1290 				goto free_map_tab;
1291 			}
1292 		}
1293 	}
1294 
1295 	ret = btf_check_and_fixup_fields(btf, map->record);
1296 	if (ret < 0)
1297 		goto free_map_tab;
1298 
1299 	if (map->ops->map_check_btf) {
1300 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1301 		if (ret < 0)
1302 			goto free_map_tab;
1303 	}
1304 
1305 	return ret;
1306 free_map_tab:
1307 	bpf_map_free_record(map);
1308 	return ret;
1309 }
1310 
bpf_net_capable(void)1311 static bool bpf_net_capable(void)
1312 {
1313 	return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
1314 }
1315 
1316 #define BPF_MAP_CREATE_LAST_FIELD map_token_fd
1317 /* called via syscall */
map_create(union bpf_attr * attr)1318 static int map_create(union bpf_attr *attr)
1319 {
1320 	const struct bpf_map_ops *ops;
1321 	struct bpf_token *token = NULL;
1322 	int numa_node = bpf_map_attr_numa_node(attr);
1323 	u32 map_type = attr->map_type;
1324 	struct bpf_map *map;
1325 	bool token_flag;
1326 	int f_flags;
1327 	int err;
1328 
1329 	err = CHECK_ATTR(BPF_MAP_CREATE);
1330 	if (err)
1331 		return -EINVAL;
1332 
1333 	/* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1334 	 * to avoid per-map type checks tripping on unknown flag
1335 	 */
1336 	token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1337 	attr->map_flags &= ~BPF_F_TOKEN_FD;
1338 
1339 	if (attr->btf_vmlinux_value_type_id) {
1340 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1341 		    attr->btf_key_type_id || attr->btf_value_type_id)
1342 			return -EINVAL;
1343 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1344 		return -EINVAL;
1345 	}
1346 
1347 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1348 	    attr->map_type != BPF_MAP_TYPE_ARENA &&
1349 	    attr->map_extra != 0)
1350 		return -EINVAL;
1351 
1352 	f_flags = bpf_get_file_flag(attr->map_flags);
1353 	if (f_flags < 0)
1354 		return f_flags;
1355 
1356 	if (numa_node != NUMA_NO_NODE &&
1357 	    ((unsigned int)numa_node >= nr_node_ids ||
1358 	     !node_online(numa_node)))
1359 		return -EINVAL;
1360 
1361 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1362 	map_type = attr->map_type;
1363 	if (map_type >= ARRAY_SIZE(bpf_map_types))
1364 		return -EINVAL;
1365 	map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1366 	ops = bpf_map_types[map_type];
1367 	if (!ops)
1368 		return -EINVAL;
1369 
1370 	if (ops->map_alloc_check) {
1371 		err = ops->map_alloc_check(attr);
1372 		if (err)
1373 			return err;
1374 	}
1375 	if (attr->map_ifindex)
1376 		ops = &bpf_map_offload_ops;
1377 	if (!ops->map_mem_usage)
1378 		return -EINVAL;
1379 
1380 	if (token_flag) {
1381 		token = bpf_token_get_from_fd(attr->map_token_fd);
1382 		if (IS_ERR(token))
1383 			return PTR_ERR(token);
1384 
1385 		/* if current token doesn't grant map creation permissions,
1386 		 * then we can't use this token, so ignore it and rely on
1387 		 * system-wide capabilities checks
1388 		 */
1389 		if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1390 		    !bpf_token_allow_map_type(token, attr->map_type)) {
1391 			bpf_token_put(token);
1392 			token = NULL;
1393 		}
1394 	}
1395 
1396 	err = -EPERM;
1397 
1398 	/* Intent here is for unprivileged_bpf_disabled to block BPF map
1399 	 * creation for unprivileged users; other actions depend
1400 	 * on fd availability and access to bpffs, so are dependent on
1401 	 * object creation success. Even with unprivileged BPF disabled,
1402 	 * capability checks are still carried out.
1403 	 */
1404 	if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1405 		goto put_token;
1406 
1407 	/* check privileged map type permissions */
1408 	switch (map_type) {
1409 	case BPF_MAP_TYPE_ARRAY:
1410 	case BPF_MAP_TYPE_PERCPU_ARRAY:
1411 	case BPF_MAP_TYPE_PROG_ARRAY:
1412 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1413 	case BPF_MAP_TYPE_CGROUP_ARRAY:
1414 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1415 	case BPF_MAP_TYPE_HASH:
1416 	case BPF_MAP_TYPE_PERCPU_HASH:
1417 	case BPF_MAP_TYPE_HASH_OF_MAPS:
1418 	case BPF_MAP_TYPE_RINGBUF:
1419 	case BPF_MAP_TYPE_USER_RINGBUF:
1420 	case BPF_MAP_TYPE_CGROUP_STORAGE:
1421 	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1422 		/* unprivileged */
1423 		break;
1424 	case BPF_MAP_TYPE_SK_STORAGE:
1425 	case BPF_MAP_TYPE_INODE_STORAGE:
1426 	case BPF_MAP_TYPE_TASK_STORAGE:
1427 	case BPF_MAP_TYPE_CGRP_STORAGE:
1428 	case BPF_MAP_TYPE_BLOOM_FILTER:
1429 	case BPF_MAP_TYPE_LPM_TRIE:
1430 	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1431 	case BPF_MAP_TYPE_STACK_TRACE:
1432 	case BPF_MAP_TYPE_QUEUE:
1433 	case BPF_MAP_TYPE_STACK:
1434 	case BPF_MAP_TYPE_LRU_HASH:
1435 	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1436 	case BPF_MAP_TYPE_STRUCT_OPS:
1437 	case BPF_MAP_TYPE_CPUMAP:
1438 	case BPF_MAP_TYPE_ARENA:
1439 		if (!bpf_token_capable(token, CAP_BPF))
1440 			goto put_token;
1441 		break;
1442 	case BPF_MAP_TYPE_SOCKMAP:
1443 	case BPF_MAP_TYPE_SOCKHASH:
1444 	case BPF_MAP_TYPE_DEVMAP:
1445 	case BPF_MAP_TYPE_DEVMAP_HASH:
1446 	case BPF_MAP_TYPE_XSKMAP:
1447 		if (!bpf_token_capable(token, CAP_NET_ADMIN))
1448 			goto put_token;
1449 		break;
1450 	default:
1451 		WARN(1, "unsupported map type %d", map_type);
1452 		goto put_token;
1453 	}
1454 
1455 	map = ops->map_alloc(attr);
1456 	if (IS_ERR(map)) {
1457 		err = PTR_ERR(map);
1458 		goto put_token;
1459 	}
1460 	map->ops = ops;
1461 	map->map_type = map_type;
1462 
1463 	err = bpf_obj_name_cpy(map->name, attr->map_name,
1464 			       sizeof(attr->map_name));
1465 	if (err < 0)
1466 		goto free_map;
1467 
1468 	atomic64_set(&map->refcnt, 1);
1469 	atomic64_set(&map->usercnt, 1);
1470 	mutex_init(&map->freeze_mutex);
1471 	spin_lock_init(&map->owner.lock);
1472 
1473 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
1474 	    /* Even the map's value is a kernel's struct,
1475 	     * the bpf_prog.o must have BTF to begin with
1476 	     * to figure out the corresponding kernel's
1477 	     * counter part.  Thus, attr->btf_fd has
1478 	     * to be valid also.
1479 	     */
1480 	    attr->btf_vmlinux_value_type_id) {
1481 		struct btf *btf;
1482 
1483 		btf = btf_get_by_fd(attr->btf_fd);
1484 		if (IS_ERR(btf)) {
1485 			err = PTR_ERR(btf);
1486 			goto free_map;
1487 		}
1488 		if (btf_is_kernel(btf)) {
1489 			btf_put(btf);
1490 			err = -EACCES;
1491 			goto free_map;
1492 		}
1493 		map->btf = btf;
1494 
1495 		if (attr->btf_value_type_id) {
1496 			err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1497 					    attr->btf_value_type_id);
1498 			if (err)
1499 				goto free_map;
1500 		}
1501 
1502 		map->btf_key_type_id = attr->btf_key_type_id;
1503 		map->btf_value_type_id = attr->btf_value_type_id;
1504 		map->btf_vmlinux_value_type_id =
1505 			attr->btf_vmlinux_value_type_id;
1506 	}
1507 
1508 	err = security_bpf_map_create(map, attr, token);
1509 	if (err)
1510 		goto free_map_sec;
1511 
1512 	err = bpf_map_alloc_id(map);
1513 	if (err)
1514 		goto free_map_sec;
1515 
1516 	bpf_map_save_memcg(map);
1517 	bpf_token_put(token);
1518 
1519 	err = bpf_map_new_fd(map, f_flags);
1520 	if (err < 0) {
1521 		/* failed to allocate fd.
1522 		 * bpf_map_put_with_uref() is needed because the above
1523 		 * bpf_map_alloc_id() has published the map
1524 		 * to the userspace and the userspace may
1525 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1526 		 */
1527 		bpf_map_put_with_uref(map);
1528 		return err;
1529 	}
1530 
1531 	return err;
1532 
1533 free_map_sec:
1534 	security_bpf_map_free(map);
1535 free_map:
1536 	bpf_map_free(map);
1537 put_token:
1538 	bpf_token_put(token);
1539 	return err;
1540 }
1541 
bpf_map_inc(struct bpf_map * map)1542 void bpf_map_inc(struct bpf_map *map)
1543 {
1544 	atomic64_inc(&map->refcnt);
1545 }
1546 EXPORT_SYMBOL_GPL(bpf_map_inc);
1547 
bpf_map_inc_with_uref(struct bpf_map * map)1548 void bpf_map_inc_with_uref(struct bpf_map *map)
1549 {
1550 	atomic64_inc(&map->refcnt);
1551 	atomic64_inc(&map->usercnt);
1552 }
1553 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1554 
bpf_map_get(u32 ufd)1555 struct bpf_map *bpf_map_get(u32 ufd)
1556 {
1557 	CLASS(fd, f)(ufd);
1558 	struct bpf_map *map = __bpf_map_get(f);
1559 
1560 	if (!IS_ERR(map))
1561 		bpf_map_inc(map);
1562 
1563 	return map;
1564 }
1565 EXPORT_SYMBOL(bpf_map_get);
1566 
bpf_map_get_with_uref(u32 ufd)1567 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1568 {
1569 	CLASS(fd, f)(ufd);
1570 	struct bpf_map *map = __bpf_map_get(f);
1571 
1572 	if (!IS_ERR(map))
1573 		bpf_map_inc_with_uref(map);
1574 
1575 	return map;
1576 }
1577 
1578 /* map_idr_lock should have been held or the map should have been
1579  * protected by rcu read lock.
1580  */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1581 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1582 {
1583 	int refold;
1584 
1585 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1586 	if (!refold)
1587 		return ERR_PTR(-ENOENT);
1588 	if (uref)
1589 		atomic64_inc(&map->usercnt);
1590 
1591 	return map;
1592 }
1593 
bpf_map_inc_not_zero(struct bpf_map * map)1594 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1595 {
1596 	spin_lock_bh(&map_idr_lock);
1597 	map = __bpf_map_inc_not_zero(map, false);
1598 	spin_unlock_bh(&map_idr_lock);
1599 
1600 	return map;
1601 }
1602 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1603 
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1604 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1605 {
1606 	return -ENOTSUPP;
1607 }
1608 
__bpf_copy_key(void __user * ukey,u64 key_size)1609 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1610 {
1611 	if (key_size)
1612 		return vmemdup_user(ukey, key_size);
1613 
1614 	if (ukey)
1615 		return ERR_PTR(-EINVAL);
1616 
1617 	return NULL;
1618 }
1619 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1620 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1621 {
1622 	if (key_size)
1623 		return kvmemdup_bpfptr(ukey, key_size);
1624 
1625 	if (!bpfptr_is_null(ukey))
1626 		return ERR_PTR(-EINVAL);
1627 
1628 	return NULL;
1629 }
1630 
1631 /* last field in 'union bpf_attr' used by this command */
1632 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1633 
map_lookup_elem(union bpf_attr * attr)1634 static int map_lookup_elem(union bpf_attr *attr)
1635 {
1636 	void __user *ukey = u64_to_user_ptr(attr->key);
1637 	void __user *uvalue = u64_to_user_ptr(attr->value);
1638 	struct bpf_map *map;
1639 	void *key, *value;
1640 	u32 value_size;
1641 	int err;
1642 
1643 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1644 		return -EINVAL;
1645 
1646 	if (attr->flags & ~BPF_F_LOCK)
1647 		return -EINVAL;
1648 
1649 	CLASS(fd, f)(attr->map_fd);
1650 	map = __bpf_map_get(f);
1651 	if (IS_ERR(map))
1652 		return PTR_ERR(map);
1653 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1654 		return -EPERM;
1655 
1656 	if ((attr->flags & BPF_F_LOCK) &&
1657 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
1658 		return -EINVAL;
1659 
1660 	key = __bpf_copy_key(ukey, map->key_size);
1661 	if (IS_ERR(key))
1662 		return PTR_ERR(key);
1663 
1664 	value_size = bpf_map_value_size(map);
1665 
1666 	err = -ENOMEM;
1667 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1668 	if (!value)
1669 		goto free_key;
1670 
1671 	if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1672 		if (copy_from_user(value, uvalue, value_size))
1673 			err = -EFAULT;
1674 		else
1675 			err = bpf_map_copy_value(map, key, value, attr->flags);
1676 		goto free_value;
1677 	}
1678 
1679 	err = bpf_map_copy_value(map, key, value, attr->flags);
1680 	if (err)
1681 		goto free_value;
1682 
1683 	err = -EFAULT;
1684 	if (copy_to_user(uvalue, value, value_size) != 0)
1685 		goto free_value;
1686 
1687 	err = 0;
1688 
1689 free_value:
1690 	kvfree(value);
1691 free_key:
1692 	kvfree(key);
1693 	return err;
1694 }
1695 
1696 
1697 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1698 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1699 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1700 {
1701 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1702 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1703 	struct bpf_map *map;
1704 	void *key, *value;
1705 	u32 value_size;
1706 	int err;
1707 
1708 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1709 		return -EINVAL;
1710 
1711 	CLASS(fd, f)(attr->map_fd);
1712 	map = __bpf_map_get(f);
1713 	if (IS_ERR(map))
1714 		return PTR_ERR(map);
1715 	bpf_map_write_active_inc(map);
1716 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1717 		err = -EPERM;
1718 		goto err_put;
1719 	}
1720 
1721 	if ((attr->flags & BPF_F_LOCK) &&
1722 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1723 		err = -EINVAL;
1724 		goto err_put;
1725 	}
1726 
1727 	key = ___bpf_copy_key(ukey, map->key_size);
1728 	if (IS_ERR(key)) {
1729 		err = PTR_ERR(key);
1730 		goto err_put;
1731 	}
1732 
1733 	value_size = bpf_map_value_size(map);
1734 	value = kvmemdup_bpfptr(uvalue, value_size);
1735 	if (IS_ERR(value)) {
1736 		err = PTR_ERR(value);
1737 		goto free_key;
1738 	}
1739 
1740 	err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1741 	if (!err)
1742 		maybe_wait_bpf_programs(map);
1743 
1744 	kvfree(value);
1745 free_key:
1746 	kvfree(key);
1747 err_put:
1748 	bpf_map_write_active_dec(map);
1749 	return err;
1750 }
1751 
1752 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1753 
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1754 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1755 {
1756 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1757 	struct bpf_map *map;
1758 	void *key;
1759 	int err;
1760 
1761 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1762 		return -EINVAL;
1763 
1764 	CLASS(fd, f)(attr->map_fd);
1765 	map = __bpf_map_get(f);
1766 	if (IS_ERR(map))
1767 		return PTR_ERR(map);
1768 	bpf_map_write_active_inc(map);
1769 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1770 		err = -EPERM;
1771 		goto err_put;
1772 	}
1773 
1774 	key = ___bpf_copy_key(ukey, map->key_size);
1775 	if (IS_ERR(key)) {
1776 		err = PTR_ERR(key);
1777 		goto err_put;
1778 	}
1779 
1780 	if (bpf_map_is_offloaded(map)) {
1781 		err = bpf_map_offload_delete_elem(map, key);
1782 		goto out;
1783 	} else if (IS_FD_PROG_ARRAY(map) ||
1784 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1785 		/* These maps require sleepable context */
1786 		err = map->ops->map_delete_elem(map, key);
1787 		goto out;
1788 	}
1789 
1790 	bpf_disable_instrumentation();
1791 	rcu_read_lock();
1792 	err = map->ops->map_delete_elem(map, key);
1793 	rcu_read_unlock();
1794 	bpf_enable_instrumentation();
1795 	if (!err)
1796 		maybe_wait_bpf_programs(map);
1797 out:
1798 	kvfree(key);
1799 err_put:
1800 	bpf_map_write_active_dec(map);
1801 	return err;
1802 }
1803 
1804 /* last field in 'union bpf_attr' used by this command */
1805 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1806 
map_get_next_key(union bpf_attr * attr)1807 static int map_get_next_key(union bpf_attr *attr)
1808 {
1809 	void __user *ukey = u64_to_user_ptr(attr->key);
1810 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1811 	struct bpf_map *map;
1812 	void *key, *next_key;
1813 	int err;
1814 
1815 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1816 		return -EINVAL;
1817 
1818 	CLASS(fd, f)(attr->map_fd);
1819 	map = __bpf_map_get(f);
1820 	if (IS_ERR(map))
1821 		return PTR_ERR(map);
1822 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1823 		return -EPERM;
1824 
1825 	if (ukey) {
1826 		key = __bpf_copy_key(ukey, map->key_size);
1827 		if (IS_ERR(key))
1828 			return PTR_ERR(key);
1829 	} else {
1830 		key = NULL;
1831 	}
1832 
1833 	err = -ENOMEM;
1834 	next_key = kvmalloc(map->key_size, GFP_USER);
1835 	if (!next_key)
1836 		goto free_key;
1837 
1838 	if (bpf_map_is_offloaded(map)) {
1839 		err = bpf_map_offload_get_next_key(map, key, next_key);
1840 		goto out;
1841 	}
1842 
1843 	rcu_read_lock();
1844 	err = map->ops->map_get_next_key(map, key, next_key);
1845 	rcu_read_unlock();
1846 out:
1847 	if (err)
1848 		goto free_next_key;
1849 
1850 	err = -EFAULT;
1851 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1852 		goto free_next_key;
1853 
1854 	err = 0;
1855 
1856 free_next_key:
1857 	kvfree(next_key);
1858 free_key:
1859 	kvfree(key);
1860 	return err;
1861 }
1862 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1863 int generic_map_delete_batch(struct bpf_map *map,
1864 			     const union bpf_attr *attr,
1865 			     union bpf_attr __user *uattr)
1866 {
1867 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1868 	u32 cp, max_count;
1869 	int err = 0;
1870 	void *key;
1871 
1872 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1873 		return -EINVAL;
1874 
1875 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1876 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1877 		return -EINVAL;
1878 	}
1879 
1880 	max_count = attr->batch.count;
1881 	if (!max_count)
1882 		return 0;
1883 
1884 	if (put_user(0, &uattr->batch.count))
1885 		return -EFAULT;
1886 
1887 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1888 	if (!key)
1889 		return -ENOMEM;
1890 
1891 	for (cp = 0; cp < max_count; cp++) {
1892 		err = -EFAULT;
1893 		if (copy_from_user(key, keys + cp * map->key_size,
1894 				   map->key_size))
1895 			break;
1896 
1897 		if (bpf_map_is_offloaded(map)) {
1898 			err = bpf_map_offload_delete_elem(map, key);
1899 			break;
1900 		}
1901 
1902 		bpf_disable_instrumentation();
1903 		rcu_read_lock();
1904 		err = map->ops->map_delete_elem(map, key);
1905 		rcu_read_unlock();
1906 		bpf_enable_instrumentation();
1907 		if (err)
1908 			break;
1909 		cond_resched();
1910 	}
1911 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1912 		err = -EFAULT;
1913 
1914 	kvfree(key);
1915 
1916 	return err;
1917 }
1918 
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1919 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1920 			     const union bpf_attr *attr,
1921 			     union bpf_attr __user *uattr)
1922 {
1923 	void __user *values = u64_to_user_ptr(attr->batch.values);
1924 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1925 	u32 value_size, cp, max_count;
1926 	void *key, *value;
1927 	int err = 0;
1928 
1929 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1930 		return -EINVAL;
1931 
1932 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1933 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1934 		return -EINVAL;
1935 	}
1936 
1937 	value_size = bpf_map_value_size(map);
1938 
1939 	max_count = attr->batch.count;
1940 	if (!max_count)
1941 		return 0;
1942 
1943 	if (put_user(0, &uattr->batch.count))
1944 		return -EFAULT;
1945 
1946 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1947 	if (!key)
1948 		return -ENOMEM;
1949 
1950 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1951 	if (!value) {
1952 		kvfree(key);
1953 		return -ENOMEM;
1954 	}
1955 
1956 	for (cp = 0; cp < max_count; cp++) {
1957 		err = -EFAULT;
1958 		if (copy_from_user(key, keys + cp * map->key_size,
1959 		    map->key_size) ||
1960 		    copy_from_user(value, values + cp * value_size, value_size))
1961 			break;
1962 
1963 		err = bpf_map_update_value(map, map_file, key, value,
1964 					   attr->batch.elem_flags);
1965 
1966 		if (err)
1967 			break;
1968 		cond_resched();
1969 	}
1970 
1971 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1972 		err = -EFAULT;
1973 
1974 	kvfree(value);
1975 	kvfree(key);
1976 
1977 	return err;
1978 }
1979 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1980 int generic_map_lookup_batch(struct bpf_map *map,
1981 				    const union bpf_attr *attr,
1982 				    union bpf_attr __user *uattr)
1983 {
1984 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
1985 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1986 	void __user *values = u64_to_user_ptr(attr->batch.values);
1987 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1988 	void *buf, *buf_prevkey, *prev_key, *key, *value;
1989 	u32 value_size, cp, max_count;
1990 	int err;
1991 
1992 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1993 		return -EINVAL;
1994 
1995 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1996 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
1997 		return -EINVAL;
1998 
1999 	value_size = bpf_map_value_size(map);
2000 
2001 	max_count = attr->batch.count;
2002 	if (!max_count)
2003 		return 0;
2004 
2005 	if (put_user(0, &uattr->batch.count))
2006 		return -EFAULT;
2007 
2008 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2009 	if (!buf_prevkey)
2010 		return -ENOMEM;
2011 
2012 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2013 	if (!buf) {
2014 		kvfree(buf_prevkey);
2015 		return -ENOMEM;
2016 	}
2017 
2018 	err = -EFAULT;
2019 	prev_key = NULL;
2020 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2021 		goto free_buf;
2022 	key = buf;
2023 	value = key + map->key_size;
2024 	if (ubatch)
2025 		prev_key = buf_prevkey;
2026 
2027 	for (cp = 0; cp < max_count;) {
2028 		rcu_read_lock();
2029 		err = map->ops->map_get_next_key(map, prev_key, key);
2030 		rcu_read_unlock();
2031 		if (err)
2032 			break;
2033 		err = bpf_map_copy_value(map, key, value,
2034 					 attr->batch.elem_flags);
2035 
2036 		if (err == -ENOENT)
2037 			goto next_key;
2038 
2039 		if (err)
2040 			goto free_buf;
2041 
2042 		if (copy_to_user(keys + cp * map->key_size, key,
2043 				 map->key_size)) {
2044 			err = -EFAULT;
2045 			goto free_buf;
2046 		}
2047 		if (copy_to_user(values + cp * value_size, value, value_size)) {
2048 			err = -EFAULT;
2049 			goto free_buf;
2050 		}
2051 
2052 		cp++;
2053 next_key:
2054 		if (!prev_key)
2055 			prev_key = buf_prevkey;
2056 
2057 		swap(prev_key, key);
2058 		cond_resched();
2059 	}
2060 
2061 	if (err == -EFAULT)
2062 		goto free_buf;
2063 
2064 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2065 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2066 		err = -EFAULT;
2067 
2068 free_buf:
2069 	kvfree(buf_prevkey);
2070 	kvfree(buf);
2071 	return err;
2072 }
2073 
2074 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2075 
map_lookup_and_delete_elem(union bpf_attr * attr)2076 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2077 {
2078 	void __user *ukey = u64_to_user_ptr(attr->key);
2079 	void __user *uvalue = u64_to_user_ptr(attr->value);
2080 	struct bpf_map *map;
2081 	void *key, *value;
2082 	u32 value_size;
2083 	int err;
2084 
2085 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2086 		return -EINVAL;
2087 
2088 	if (attr->flags & ~BPF_F_LOCK)
2089 		return -EINVAL;
2090 
2091 	CLASS(fd, f)(attr->map_fd);
2092 	map = __bpf_map_get(f);
2093 	if (IS_ERR(map))
2094 		return PTR_ERR(map);
2095 	bpf_map_write_active_inc(map);
2096 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2097 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2098 		err = -EPERM;
2099 		goto err_put;
2100 	}
2101 
2102 	if (attr->flags &&
2103 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
2104 	     map->map_type == BPF_MAP_TYPE_STACK)) {
2105 		err = -EINVAL;
2106 		goto err_put;
2107 	}
2108 
2109 	if ((attr->flags & BPF_F_LOCK) &&
2110 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2111 		err = -EINVAL;
2112 		goto err_put;
2113 	}
2114 
2115 	key = __bpf_copy_key(ukey, map->key_size);
2116 	if (IS_ERR(key)) {
2117 		err = PTR_ERR(key);
2118 		goto err_put;
2119 	}
2120 
2121 	value_size = bpf_map_value_size(map);
2122 
2123 	err = -ENOMEM;
2124 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2125 	if (!value)
2126 		goto free_key;
2127 
2128 	err = -ENOTSUPP;
2129 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2130 	    map->map_type == BPF_MAP_TYPE_STACK) {
2131 		err = map->ops->map_pop_elem(map, value);
2132 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
2133 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2134 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2135 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
2136 		if (!bpf_map_is_offloaded(map)) {
2137 			bpf_disable_instrumentation();
2138 			rcu_read_lock();
2139 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2140 			rcu_read_unlock();
2141 			bpf_enable_instrumentation();
2142 		}
2143 	}
2144 
2145 	if (err)
2146 		goto free_value;
2147 
2148 	if (copy_to_user(uvalue, value, value_size) != 0) {
2149 		err = -EFAULT;
2150 		goto free_value;
2151 	}
2152 
2153 	err = 0;
2154 
2155 free_value:
2156 	kvfree(value);
2157 free_key:
2158 	kvfree(key);
2159 err_put:
2160 	bpf_map_write_active_dec(map);
2161 	return err;
2162 }
2163 
2164 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2165 
map_freeze(const union bpf_attr * attr)2166 static int map_freeze(const union bpf_attr *attr)
2167 {
2168 	int err = 0;
2169 	struct bpf_map *map;
2170 
2171 	if (CHECK_ATTR(BPF_MAP_FREEZE))
2172 		return -EINVAL;
2173 
2174 	CLASS(fd, f)(attr->map_fd);
2175 	map = __bpf_map_get(f);
2176 	if (IS_ERR(map))
2177 		return PTR_ERR(map);
2178 
2179 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2180 		return -ENOTSUPP;
2181 
2182 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2183 		return -EPERM;
2184 
2185 	mutex_lock(&map->freeze_mutex);
2186 	if (bpf_map_write_active(map)) {
2187 		err = -EBUSY;
2188 		goto err_put;
2189 	}
2190 	if (READ_ONCE(map->frozen)) {
2191 		err = -EBUSY;
2192 		goto err_put;
2193 	}
2194 
2195 	WRITE_ONCE(map->frozen, true);
2196 err_put:
2197 	mutex_unlock(&map->freeze_mutex);
2198 	return err;
2199 }
2200 
2201 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2202 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2203 	[_id] = & _name ## _prog_ops,
2204 #define BPF_MAP_TYPE(_id, _ops)
2205 #define BPF_LINK_TYPE(_id, _name)
2206 #include <linux/bpf_types.h>
2207 #undef BPF_PROG_TYPE
2208 #undef BPF_MAP_TYPE
2209 #undef BPF_LINK_TYPE
2210 };
2211 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2212 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2213 {
2214 	const struct bpf_prog_ops *ops;
2215 
2216 	if (type >= ARRAY_SIZE(bpf_prog_types))
2217 		return -EINVAL;
2218 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2219 	ops = bpf_prog_types[type];
2220 	if (!ops)
2221 		return -EINVAL;
2222 
2223 	if (!bpf_prog_is_offloaded(prog->aux))
2224 		prog->aux->ops = ops;
2225 	else
2226 		prog->aux->ops = &bpf_offload_prog_ops;
2227 	prog->type = type;
2228 	return 0;
2229 }
2230 
2231 enum bpf_audit {
2232 	BPF_AUDIT_LOAD,
2233 	BPF_AUDIT_UNLOAD,
2234 	BPF_AUDIT_MAX,
2235 };
2236 
2237 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2238 	[BPF_AUDIT_LOAD]   = "LOAD",
2239 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
2240 };
2241 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2242 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2243 {
2244 	struct audit_context *ctx = NULL;
2245 	struct audit_buffer *ab;
2246 
2247 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2248 		return;
2249 	if (audit_enabled == AUDIT_OFF)
2250 		return;
2251 	if (!in_irq() && !irqs_disabled())
2252 		ctx = audit_context();
2253 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2254 	if (unlikely(!ab))
2255 		return;
2256 	audit_log_format(ab, "prog-id=%u op=%s",
2257 			 prog->aux->id, bpf_audit_str[op]);
2258 	audit_log_end(ab);
2259 }
2260 
bpf_prog_alloc_id(struct bpf_prog * prog)2261 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2262 {
2263 	int id;
2264 
2265 	idr_preload(GFP_KERNEL);
2266 	spin_lock_bh(&prog_idr_lock);
2267 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2268 	if (id > 0)
2269 		prog->aux->id = id;
2270 	spin_unlock_bh(&prog_idr_lock);
2271 	idr_preload_end();
2272 
2273 	/* id is in [1, INT_MAX) */
2274 	if (WARN_ON_ONCE(!id))
2275 		return -ENOSPC;
2276 
2277 	return id > 0 ? 0 : id;
2278 }
2279 
bpf_prog_free_id(struct bpf_prog * prog)2280 void bpf_prog_free_id(struct bpf_prog *prog)
2281 {
2282 	unsigned long flags;
2283 
2284 	/* cBPF to eBPF migrations are currently not in the idr store.
2285 	 * Offloaded programs are removed from the store when their device
2286 	 * disappears - even if someone grabs an fd to them they are unusable,
2287 	 * simply waiting for refcnt to drop to be freed.
2288 	 */
2289 	if (!prog->aux->id)
2290 		return;
2291 
2292 	spin_lock_irqsave(&prog_idr_lock, flags);
2293 	idr_remove(&prog_idr, prog->aux->id);
2294 	prog->aux->id = 0;
2295 	spin_unlock_irqrestore(&prog_idr_lock, flags);
2296 }
2297 
__bpf_prog_put_rcu(struct rcu_head * rcu)2298 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2299 {
2300 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2301 
2302 	kvfree(aux->func_info);
2303 	kfree(aux->func_info_aux);
2304 	free_uid(aux->user);
2305 	security_bpf_prog_free(aux->prog);
2306 	bpf_prog_free(aux->prog);
2307 }
2308 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2309 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2310 {
2311 	bpf_prog_kallsyms_del_all(prog);
2312 	btf_put(prog->aux->btf);
2313 	module_put(prog->aux->mod);
2314 	kvfree(prog->aux->jited_linfo);
2315 	kvfree(prog->aux->linfo);
2316 	kfree(prog->aux->kfunc_tab);
2317 	if (prog->aux->attach_btf)
2318 		btf_put(prog->aux->attach_btf);
2319 
2320 	if (deferred) {
2321 		if (prog->sleepable)
2322 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2323 		else
2324 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2325 	} else {
2326 		__bpf_prog_put_rcu(&prog->aux->rcu);
2327 	}
2328 }
2329 
bpf_prog_put_deferred(struct work_struct * work)2330 static void bpf_prog_put_deferred(struct work_struct *work)
2331 {
2332 	struct bpf_prog_aux *aux;
2333 	struct bpf_prog *prog;
2334 
2335 	aux = container_of(work, struct bpf_prog_aux, work);
2336 	prog = aux->prog;
2337 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2338 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2339 	bpf_prog_free_id(prog);
2340 	__bpf_prog_put_noref(prog, true);
2341 }
2342 
__bpf_prog_put(struct bpf_prog * prog)2343 static void __bpf_prog_put(struct bpf_prog *prog)
2344 {
2345 	struct bpf_prog_aux *aux = prog->aux;
2346 
2347 	if (atomic64_dec_and_test(&aux->refcnt)) {
2348 		if (in_irq() || irqs_disabled()) {
2349 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
2350 			schedule_work(&aux->work);
2351 		} else {
2352 			bpf_prog_put_deferred(&aux->work);
2353 		}
2354 	}
2355 }
2356 
bpf_prog_put(struct bpf_prog * prog)2357 void bpf_prog_put(struct bpf_prog *prog)
2358 {
2359 	__bpf_prog_put(prog);
2360 }
2361 EXPORT_SYMBOL_GPL(bpf_prog_put);
2362 
bpf_prog_release(struct inode * inode,struct file * filp)2363 static int bpf_prog_release(struct inode *inode, struct file *filp)
2364 {
2365 	struct bpf_prog *prog = filp->private_data;
2366 
2367 	bpf_prog_put(prog);
2368 	return 0;
2369 }
2370 
2371 struct bpf_prog_kstats {
2372 	u64 nsecs;
2373 	u64 cnt;
2374 	u64 misses;
2375 };
2376 
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2377 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2378 {
2379 	struct bpf_prog_stats *stats;
2380 	unsigned int flags;
2381 
2382 	stats = this_cpu_ptr(prog->stats);
2383 	flags = u64_stats_update_begin_irqsave(&stats->syncp);
2384 	u64_stats_inc(&stats->misses);
2385 	u64_stats_update_end_irqrestore(&stats->syncp, flags);
2386 }
2387 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2388 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2389 			       struct bpf_prog_kstats *stats)
2390 {
2391 	u64 nsecs = 0, cnt = 0, misses = 0;
2392 	int cpu;
2393 
2394 	for_each_possible_cpu(cpu) {
2395 		const struct bpf_prog_stats *st;
2396 		unsigned int start;
2397 		u64 tnsecs, tcnt, tmisses;
2398 
2399 		st = per_cpu_ptr(prog->stats, cpu);
2400 		do {
2401 			start = u64_stats_fetch_begin(&st->syncp);
2402 			tnsecs = u64_stats_read(&st->nsecs);
2403 			tcnt = u64_stats_read(&st->cnt);
2404 			tmisses = u64_stats_read(&st->misses);
2405 		} while (u64_stats_fetch_retry(&st->syncp, start));
2406 		nsecs += tnsecs;
2407 		cnt += tcnt;
2408 		misses += tmisses;
2409 	}
2410 	stats->nsecs = nsecs;
2411 	stats->cnt = cnt;
2412 	stats->misses = misses;
2413 }
2414 
2415 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2416 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2417 {
2418 	const struct bpf_prog *prog = filp->private_data;
2419 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2420 	struct bpf_prog_kstats stats;
2421 
2422 	bpf_prog_get_stats(prog, &stats);
2423 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2424 	seq_printf(m,
2425 		   "prog_type:\t%u\n"
2426 		   "prog_jited:\t%u\n"
2427 		   "prog_tag:\t%s\n"
2428 		   "memlock:\t%llu\n"
2429 		   "prog_id:\t%u\n"
2430 		   "run_time_ns:\t%llu\n"
2431 		   "run_cnt:\t%llu\n"
2432 		   "recursion_misses:\t%llu\n"
2433 		   "verified_insns:\t%u\n",
2434 		   prog->type,
2435 		   prog->jited,
2436 		   prog_tag,
2437 		   prog->pages * 1ULL << PAGE_SHIFT,
2438 		   prog->aux->id,
2439 		   stats.nsecs,
2440 		   stats.cnt,
2441 		   stats.misses,
2442 		   prog->aux->verified_insns);
2443 }
2444 #endif
2445 
2446 const struct file_operations bpf_prog_fops = {
2447 #ifdef CONFIG_PROC_FS
2448 	.show_fdinfo	= bpf_prog_show_fdinfo,
2449 #endif
2450 	.release	= bpf_prog_release,
2451 	.read		= bpf_dummy_read,
2452 	.write		= bpf_dummy_write,
2453 };
2454 
bpf_prog_new_fd(struct bpf_prog * prog)2455 int bpf_prog_new_fd(struct bpf_prog *prog)
2456 {
2457 	int ret;
2458 
2459 	ret = security_bpf_prog(prog);
2460 	if (ret < 0)
2461 		return ret;
2462 
2463 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2464 				O_RDWR | O_CLOEXEC);
2465 }
2466 
bpf_prog_add(struct bpf_prog * prog,int i)2467 void bpf_prog_add(struct bpf_prog *prog, int i)
2468 {
2469 	atomic64_add(i, &prog->aux->refcnt);
2470 }
2471 EXPORT_SYMBOL_GPL(bpf_prog_add);
2472 
bpf_prog_sub(struct bpf_prog * prog,int i)2473 void bpf_prog_sub(struct bpf_prog *prog, int i)
2474 {
2475 	/* Only to be used for undoing previous bpf_prog_add() in some
2476 	 * error path. We still know that another entity in our call
2477 	 * path holds a reference to the program, thus atomic_sub() can
2478 	 * be safely used in such cases!
2479 	 */
2480 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2481 }
2482 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2483 
bpf_prog_inc(struct bpf_prog * prog)2484 void bpf_prog_inc(struct bpf_prog *prog)
2485 {
2486 	atomic64_inc(&prog->aux->refcnt);
2487 }
2488 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2489 
2490 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2491 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2492 {
2493 	int refold;
2494 
2495 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2496 
2497 	if (!refold)
2498 		return ERR_PTR(-ENOENT);
2499 
2500 	return prog;
2501 }
2502 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2503 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2504 bool bpf_prog_get_ok(struct bpf_prog *prog,
2505 			    enum bpf_prog_type *attach_type, bool attach_drv)
2506 {
2507 	/* not an attachment, just a refcount inc, always allow */
2508 	if (!attach_type)
2509 		return true;
2510 
2511 	if (prog->type != *attach_type)
2512 		return false;
2513 	if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2514 		return false;
2515 
2516 	return true;
2517 }
2518 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2519 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2520 				       bool attach_drv)
2521 {
2522 	CLASS(fd, f)(ufd);
2523 	struct bpf_prog *prog;
2524 
2525 	if (fd_empty(f))
2526 		return ERR_PTR(-EBADF);
2527 	if (fd_file(f)->f_op != &bpf_prog_fops)
2528 		return ERR_PTR(-EINVAL);
2529 
2530 	prog = fd_file(f)->private_data;
2531 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2532 		return ERR_PTR(-EINVAL);
2533 
2534 	bpf_prog_inc(prog);
2535 	return prog;
2536 }
2537 
bpf_prog_get(u32 ufd)2538 struct bpf_prog *bpf_prog_get(u32 ufd)
2539 {
2540 	return __bpf_prog_get(ufd, NULL, false);
2541 }
2542 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2543 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2544 				       bool attach_drv)
2545 {
2546 	return __bpf_prog_get(ufd, &type, attach_drv);
2547 }
2548 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2549 
2550 /* Initially all BPF programs could be loaded w/o specifying
2551  * expected_attach_type. Later for some of them specifying expected_attach_type
2552  * at load time became required so that program could be validated properly.
2553  * Programs of types that are allowed to be loaded both w/ and w/o (for
2554  * backward compatibility) expected_attach_type, should have the default attach
2555  * type assigned to expected_attach_type for the latter case, so that it can be
2556  * validated later at attach time.
2557  *
2558  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2559  * prog type requires it but has some attach types that have to be backward
2560  * compatible.
2561  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2562 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2563 {
2564 	switch (attr->prog_type) {
2565 	case BPF_PROG_TYPE_CGROUP_SOCK:
2566 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2567 		 * exist so checking for non-zero is the way to go here.
2568 		 */
2569 		if (!attr->expected_attach_type)
2570 			attr->expected_attach_type =
2571 				BPF_CGROUP_INET_SOCK_CREATE;
2572 		break;
2573 	case BPF_PROG_TYPE_SK_REUSEPORT:
2574 		if (!attr->expected_attach_type)
2575 			attr->expected_attach_type =
2576 				BPF_SK_REUSEPORT_SELECT;
2577 		break;
2578 	}
2579 }
2580 
2581 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)2582 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2583 			   enum bpf_attach_type expected_attach_type,
2584 			   struct btf *attach_btf, u32 btf_id,
2585 			   struct bpf_prog *dst_prog)
2586 {
2587 	if (btf_id) {
2588 		if (btf_id > BTF_MAX_TYPE)
2589 			return -EINVAL;
2590 
2591 		if (!attach_btf && !dst_prog)
2592 			return -EINVAL;
2593 
2594 		switch (prog_type) {
2595 		case BPF_PROG_TYPE_TRACING:
2596 		case BPF_PROG_TYPE_LSM:
2597 		case BPF_PROG_TYPE_STRUCT_OPS:
2598 		case BPF_PROG_TYPE_EXT:
2599 			break;
2600 		default:
2601 			return -EINVAL;
2602 		}
2603 	}
2604 
2605 	if (attach_btf && (!btf_id || dst_prog))
2606 		return -EINVAL;
2607 
2608 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2609 	    prog_type != BPF_PROG_TYPE_EXT)
2610 		return -EINVAL;
2611 
2612 	switch (prog_type) {
2613 	case BPF_PROG_TYPE_CGROUP_SOCK:
2614 		switch (expected_attach_type) {
2615 		case BPF_CGROUP_INET_SOCK_CREATE:
2616 		case BPF_CGROUP_INET_SOCK_RELEASE:
2617 		case BPF_CGROUP_INET4_POST_BIND:
2618 		case BPF_CGROUP_INET6_POST_BIND:
2619 			return 0;
2620 		default:
2621 			return -EINVAL;
2622 		}
2623 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2624 		switch (expected_attach_type) {
2625 		case BPF_CGROUP_INET4_BIND:
2626 		case BPF_CGROUP_INET6_BIND:
2627 		case BPF_CGROUP_INET4_CONNECT:
2628 		case BPF_CGROUP_INET6_CONNECT:
2629 		case BPF_CGROUP_UNIX_CONNECT:
2630 		case BPF_CGROUP_INET4_GETPEERNAME:
2631 		case BPF_CGROUP_INET6_GETPEERNAME:
2632 		case BPF_CGROUP_UNIX_GETPEERNAME:
2633 		case BPF_CGROUP_INET4_GETSOCKNAME:
2634 		case BPF_CGROUP_INET6_GETSOCKNAME:
2635 		case BPF_CGROUP_UNIX_GETSOCKNAME:
2636 		case BPF_CGROUP_UDP4_SENDMSG:
2637 		case BPF_CGROUP_UDP6_SENDMSG:
2638 		case BPF_CGROUP_UNIX_SENDMSG:
2639 		case BPF_CGROUP_UDP4_RECVMSG:
2640 		case BPF_CGROUP_UDP6_RECVMSG:
2641 		case BPF_CGROUP_UNIX_RECVMSG:
2642 			return 0;
2643 		default:
2644 			return -EINVAL;
2645 		}
2646 	case BPF_PROG_TYPE_CGROUP_SKB:
2647 		switch (expected_attach_type) {
2648 		case BPF_CGROUP_INET_INGRESS:
2649 		case BPF_CGROUP_INET_EGRESS:
2650 			return 0;
2651 		default:
2652 			return -EINVAL;
2653 		}
2654 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2655 		switch (expected_attach_type) {
2656 		case BPF_CGROUP_SETSOCKOPT:
2657 		case BPF_CGROUP_GETSOCKOPT:
2658 			return 0;
2659 		default:
2660 			return -EINVAL;
2661 		}
2662 	case BPF_PROG_TYPE_SK_LOOKUP:
2663 		if (expected_attach_type == BPF_SK_LOOKUP)
2664 			return 0;
2665 		return -EINVAL;
2666 	case BPF_PROG_TYPE_SK_REUSEPORT:
2667 		switch (expected_attach_type) {
2668 		case BPF_SK_REUSEPORT_SELECT:
2669 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2670 			return 0;
2671 		default:
2672 			return -EINVAL;
2673 		}
2674 	case BPF_PROG_TYPE_NETFILTER:
2675 		if (expected_attach_type == BPF_NETFILTER)
2676 			return 0;
2677 		return -EINVAL;
2678 	case BPF_PROG_TYPE_SYSCALL:
2679 	case BPF_PROG_TYPE_EXT:
2680 		if (expected_attach_type)
2681 			return -EINVAL;
2682 		fallthrough;
2683 	default:
2684 		return 0;
2685 	}
2686 }
2687 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2688 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2689 {
2690 	switch (prog_type) {
2691 	case BPF_PROG_TYPE_SCHED_CLS:
2692 	case BPF_PROG_TYPE_SCHED_ACT:
2693 	case BPF_PROG_TYPE_XDP:
2694 	case BPF_PROG_TYPE_LWT_IN:
2695 	case BPF_PROG_TYPE_LWT_OUT:
2696 	case BPF_PROG_TYPE_LWT_XMIT:
2697 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2698 	case BPF_PROG_TYPE_SK_SKB:
2699 	case BPF_PROG_TYPE_SK_MSG:
2700 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2701 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2702 	case BPF_PROG_TYPE_CGROUP_SOCK:
2703 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2704 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2705 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2706 	case BPF_PROG_TYPE_SOCK_OPS:
2707 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2708 	case BPF_PROG_TYPE_NETFILTER:
2709 		return true;
2710 	case BPF_PROG_TYPE_CGROUP_SKB:
2711 		/* always unpriv */
2712 	case BPF_PROG_TYPE_SK_REUSEPORT:
2713 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2714 	default:
2715 		return false;
2716 	}
2717 }
2718 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2719 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2720 {
2721 	switch (prog_type) {
2722 	case BPF_PROG_TYPE_KPROBE:
2723 	case BPF_PROG_TYPE_TRACEPOINT:
2724 	case BPF_PROG_TYPE_PERF_EVENT:
2725 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2726 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2727 	case BPF_PROG_TYPE_TRACING:
2728 	case BPF_PROG_TYPE_LSM:
2729 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2730 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2731 		return true;
2732 	default:
2733 		return false;
2734 	}
2735 }
2736 
2737 /* last field in 'union bpf_attr' used by this command */
2738 #define BPF_PROG_LOAD_LAST_FIELD fd_array_cnt
2739 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2740 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2741 {
2742 	enum bpf_prog_type type = attr->prog_type;
2743 	struct bpf_prog *prog, *dst_prog = NULL;
2744 	struct btf *attach_btf = NULL;
2745 	struct bpf_token *token = NULL;
2746 	bool bpf_cap;
2747 	int err;
2748 	char license[128];
2749 
2750 	if (CHECK_ATTR(BPF_PROG_LOAD))
2751 		return -EINVAL;
2752 
2753 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2754 				 BPF_F_ANY_ALIGNMENT |
2755 				 BPF_F_TEST_STATE_FREQ |
2756 				 BPF_F_SLEEPABLE |
2757 				 BPF_F_TEST_RND_HI32 |
2758 				 BPF_F_XDP_HAS_FRAGS |
2759 				 BPF_F_XDP_DEV_BOUND_ONLY |
2760 				 BPF_F_TEST_REG_INVARIANTS |
2761 				 BPF_F_TOKEN_FD))
2762 		return -EINVAL;
2763 
2764 	bpf_prog_load_fixup_attach_type(attr);
2765 
2766 	if (attr->prog_flags & BPF_F_TOKEN_FD) {
2767 		token = bpf_token_get_from_fd(attr->prog_token_fd);
2768 		if (IS_ERR(token))
2769 			return PTR_ERR(token);
2770 		/* if current token doesn't grant prog loading permissions,
2771 		 * then we can't use this token, so ignore it and rely on
2772 		 * system-wide capabilities checks
2773 		 */
2774 		if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2775 		    !bpf_token_allow_prog_type(token, attr->prog_type,
2776 					       attr->expected_attach_type)) {
2777 			bpf_token_put(token);
2778 			token = NULL;
2779 		}
2780 	}
2781 
2782 	bpf_cap = bpf_token_capable(token, CAP_BPF);
2783 	err = -EPERM;
2784 
2785 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2786 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2787 	    !bpf_cap)
2788 		goto put_token;
2789 
2790 	/* Intent here is for unprivileged_bpf_disabled to block BPF program
2791 	 * creation for unprivileged users; other actions depend
2792 	 * on fd availability and access to bpffs, so are dependent on
2793 	 * object creation success. Even with unprivileged BPF disabled,
2794 	 * capability checks are still carried out for these
2795 	 * and other operations.
2796 	 */
2797 	if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2798 		goto put_token;
2799 
2800 	if (attr->insn_cnt == 0 ||
2801 	    attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2802 		err = -E2BIG;
2803 		goto put_token;
2804 	}
2805 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2806 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2807 	    !bpf_cap)
2808 		goto put_token;
2809 
2810 	if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2811 		goto put_token;
2812 	if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2813 		goto put_token;
2814 
2815 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2816 	 * or btf, we need to check which one it is
2817 	 */
2818 	if (attr->attach_prog_fd) {
2819 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2820 		if (IS_ERR(dst_prog)) {
2821 			dst_prog = NULL;
2822 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2823 			if (IS_ERR(attach_btf)) {
2824 				err = -EINVAL;
2825 				goto put_token;
2826 			}
2827 			if (!btf_is_kernel(attach_btf)) {
2828 				/* attaching through specifying bpf_prog's BTF
2829 				 * objects directly might be supported eventually
2830 				 */
2831 				btf_put(attach_btf);
2832 				err = -ENOTSUPP;
2833 				goto put_token;
2834 			}
2835 		}
2836 	} else if (attr->attach_btf_id) {
2837 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2838 		attach_btf = bpf_get_btf_vmlinux();
2839 		if (IS_ERR(attach_btf)) {
2840 			err = PTR_ERR(attach_btf);
2841 			goto put_token;
2842 		}
2843 		if (!attach_btf) {
2844 			err = -EINVAL;
2845 			goto put_token;
2846 		}
2847 		btf_get(attach_btf);
2848 	}
2849 
2850 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2851 				       attach_btf, attr->attach_btf_id,
2852 				       dst_prog)) {
2853 		if (dst_prog)
2854 			bpf_prog_put(dst_prog);
2855 		if (attach_btf)
2856 			btf_put(attach_btf);
2857 		err = -EINVAL;
2858 		goto put_token;
2859 	}
2860 
2861 	/* plain bpf_prog allocation */
2862 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2863 	if (!prog) {
2864 		if (dst_prog)
2865 			bpf_prog_put(dst_prog);
2866 		if (attach_btf)
2867 			btf_put(attach_btf);
2868 		err = -EINVAL;
2869 		goto put_token;
2870 	}
2871 
2872 	prog->expected_attach_type = attr->expected_attach_type;
2873 	prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
2874 	prog->aux->attach_btf = attach_btf;
2875 	prog->aux->attach_btf_id = attr->attach_btf_id;
2876 	prog->aux->dst_prog = dst_prog;
2877 	prog->aux->dev_bound = !!attr->prog_ifindex;
2878 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
2879 
2880 	/* move token into prog->aux, reuse taken refcnt */
2881 	prog->aux->token = token;
2882 	token = NULL;
2883 
2884 	prog->aux->user = get_current_user();
2885 	prog->len = attr->insn_cnt;
2886 
2887 	err = -EFAULT;
2888 	if (copy_from_bpfptr(prog->insns,
2889 			     make_bpfptr(attr->insns, uattr.is_kernel),
2890 			     bpf_prog_insn_size(prog)) != 0)
2891 		goto free_prog;
2892 	/* copy eBPF program license from user space */
2893 	if (strncpy_from_bpfptr(license,
2894 				make_bpfptr(attr->license, uattr.is_kernel),
2895 				sizeof(license) - 1) < 0)
2896 		goto free_prog;
2897 	license[sizeof(license) - 1] = 0;
2898 
2899 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
2900 	prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
2901 
2902 	prog->orig_prog = NULL;
2903 	prog->jited = 0;
2904 
2905 	atomic64_set(&prog->aux->refcnt, 1);
2906 
2907 	if (bpf_prog_is_dev_bound(prog->aux)) {
2908 		err = bpf_prog_dev_bound_init(prog, attr);
2909 		if (err)
2910 			goto free_prog;
2911 	}
2912 
2913 	if (type == BPF_PROG_TYPE_EXT && dst_prog &&
2914 	    bpf_prog_is_dev_bound(dst_prog->aux)) {
2915 		err = bpf_prog_dev_bound_inherit(prog, dst_prog);
2916 		if (err)
2917 			goto free_prog;
2918 	}
2919 
2920 	/*
2921 	 * Bookkeeping for managing the program attachment chain.
2922 	 *
2923 	 * It might be tempting to set attach_tracing_prog flag at the attachment
2924 	 * time, but this will not prevent from loading bunch of tracing prog
2925 	 * first, then attach them one to another.
2926 	 *
2927 	 * The flag attach_tracing_prog is set for the whole program lifecycle, and
2928 	 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
2929 	 * programs cannot change attachment target.
2930 	 */
2931 	if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
2932 	    dst_prog->type == BPF_PROG_TYPE_TRACING) {
2933 		prog->aux->attach_tracing_prog = true;
2934 	}
2935 
2936 	/* find program type: socket_filter vs tracing_filter */
2937 	err = find_prog_type(type, prog);
2938 	if (err < 0)
2939 		goto free_prog;
2940 
2941 	prog->aux->load_time = ktime_get_boottime_ns();
2942 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2943 			       sizeof(attr->prog_name));
2944 	if (err < 0)
2945 		goto free_prog;
2946 
2947 	err = security_bpf_prog_load(prog, attr, token);
2948 	if (err)
2949 		goto free_prog_sec;
2950 
2951 	/* run eBPF verifier */
2952 	err = bpf_check(&prog, attr, uattr, uattr_size);
2953 	if (err < 0)
2954 		goto free_used_maps;
2955 
2956 	prog = bpf_prog_select_runtime(prog, &err);
2957 	if (err < 0)
2958 		goto free_used_maps;
2959 
2960 	err = bpf_prog_alloc_id(prog);
2961 	if (err)
2962 		goto free_used_maps;
2963 
2964 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
2965 	 * effectively publicly exposed. However, retrieving via
2966 	 * bpf_prog_get_fd_by_id() will take another reference,
2967 	 * therefore it cannot be gone underneath us.
2968 	 *
2969 	 * Only for the time /after/ successful bpf_prog_new_fd()
2970 	 * and before returning to userspace, we might just hold
2971 	 * one reference and any parallel close on that fd could
2972 	 * rip everything out. Hence, below notifications must
2973 	 * happen before bpf_prog_new_fd().
2974 	 *
2975 	 * Also, any failure handling from this point onwards must
2976 	 * be using bpf_prog_put() given the program is exposed.
2977 	 */
2978 	bpf_prog_kallsyms_add(prog);
2979 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2980 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
2981 
2982 	err = bpf_prog_new_fd(prog);
2983 	if (err < 0)
2984 		bpf_prog_put(prog);
2985 	return err;
2986 
2987 free_used_maps:
2988 	/* In case we have subprogs, we need to wait for a grace
2989 	 * period before we can tear down JIT memory since symbols
2990 	 * are already exposed under kallsyms.
2991 	 */
2992 	__bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
2993 	return err;
2994 
2995 free_prog_sec:
2996 	security_bpf_prog_free(prog);
2997 free_prog:
2998 	free_uid(prog->aux->user);
2999 	if (prog->aux->attach_btf)
3000 		btf_put(prog->aux->attach_btf);
3001 	bpf_prog_free(prog);
3002 put_token:
3003 	bpf_token_put(token);
3004 	return err;
3005 }
3006 
3007 #define BPF_OBJ_LAST_FIELD path_fd
3008 
bpf_obj_pin(const union bpf_attr * attr)3009 static int bpf_obj_pin(const union bpf_attr *attr)
3010 {
3011 	int path_fd;
3012 
3013 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3014 		return -EINVAL;
3015 
3016 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3017 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3018 		return -EINVAL;
3019 
3020 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3021 	return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3022 				u64_to_user_ptr(attr->pathname));
3023 }
3024 
bpf_obj_get(const union bpf_attr * attr)3025 static int bpf_obj_get(const union bpf_attr *attr)
3026 {
3027 	int path_fd;
3028 
3029 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3030 	    attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3031 		return -EINVAL;
3032 
3033 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3034 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3035 		return -EINVAL;
3036 
3037 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3038 	return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3039 				attr->file_flags);
3040 }
3041 
3042 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3043  * "sleepable" semantics, which normally would mean that BPF link's attach
3044  * hook can dereference link or link's underlying program for some time after
3045  * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3046  * BPF program itself can be non-sleepable, yet, because it's transitively
3047  * reachable through BPF link, its freeing has to be delayed until after RCU
3048  * Tasks Trace GP.
3049  */
bpf_link_init_sleepable(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,bool sleepable)3050 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3051 			     const struct bpf_link_ops *ops, struct bpf_prog *prog,
3052 			     bool sleepable)
3053 {
3054 	WARN_ON(ops->dealloc && ops->dealloc_deferred);
3055 	atomic64_set(&link->refcnt, 1);
3056 	link->type = type;
3057 	link->sleepable = sleepable;
3058 	link->id = 0;
3059 	link->ops = ops;
3060 	link->prog = prog;
3061 }
3062 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)3063 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3064 		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
3065 {
3066 	bpf_link_init_sleepable(link, type, ops, prog, false);
3067 }
3068 
bpf_link_free_id(int id)3069 static void bpf_link_free_id(int id)
3070 {
3071 	if (!id)
3072 		return;
3073 
3074 	spin_lock_bh(&link_idr_lock);
3075 	idr_remove(&link_idr, id);
3076 	spin_unlock_bh(&link_idr_lock);
3077 }
3078 
3079 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3080  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3081  * anon_inode's release() call. This helper marks bpf_link as
3082  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3083  * is not decremented, it's the responsibility of a calling code that failed
3084  * to complete bpf_link initialization.
3085  * This helper eventually calls link's dealloc callback, but does not call
3086  * link's release callback.
3087  */
bpf_link_cleanup(struct bpf_link_primer * primer)3088 void bpf_link_cleanup(struct bpf_link_primer *primer)
3089 {
3090 	primer->link->prog = NULL;
3091 	bpf_link_free_id(primer->id);
3092 	fput(primer->file);
3093 	put_unused_fd(primer->fd);
3094 }
3095 
bpf_link_inc(struct bpf_link * link)3096 void bpf_link_inc(struct bpf_link *link)
3097 {
3098 	atomic64_inc(&link->refcnt);
3099 }
3100 
bpf_link_dealloc(struct bpf_link * link)3101 static void bpf_link_dealloc(struct bpf_link *link)
3102 {
3103 	/* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3104 	if (link->prog)
3105 		bpf_prog_put(link->prog);
3106 
3107 	/* free bpf_link and its containing memory */
3108 	if (link->ops->dealloc_deferred)
3109 		link->ops->dealloc_deferred(link);
3110 	else
3111 		link->ops->dealloc(link);
3112 }
3113 
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3114 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3115 {
3116 	struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3117 
3118 	bpf_link_dealloc(link);
3119 }
3120 
bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head * rcu)3121 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
3122 {
3123 	if (rcu_trace_implies_rcu_gp())
3124 		bpf_link_defer_dealloc_rcu_gp(rcu);
3125 	else
3126 		call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
3127 }
3128 
3129 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3130 static void bpf_link_free(struct bpf_link *link)
3131 {
3132 	const struct bpf_link_ops *ops = link->ops;
3133 
3134 	bpf_link_free_id(link->id);
3135 	/* detach BPF program, clean up used resources */
3136 	if (link->prog)
3137 		ops->release(link);
3138 	if (ops->dealloc_deferred) {
3139 		/* Schedule BPF link deallocation, which will only then
3140 		 * trigger putting BPF program refcount.
3141 		 * If underlying BPF program is sleepable or BPF link's target
3142 		 * attach hookpoint is sleepable or otherwise requires RCU GPs
3143 		 * to ensure link and its underlying BPF program is not
3144 		 * reachable anymore, we need to first wait for RCU tasks
3145 		 * trace sync, and then go through "classic" RCU grace period
3146 		 */
3147 		if (link->sleepable || (link->prog && link->prog->sleepable))
3148 			call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
3149 		else
3150 			call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3151 	} else if (ops->dealloc) {
3152 		bpf_link_dealloc(link);
3153 	}
3154 }
3155 
bpf_link_put_deferred(struct work_struct * work)3156 static void bpf_link_put_deferred(struct work_struct *work)
3157 {
3158 	struct bpf_link *link = container_of(work, struct bpf_link, work);
3159 
3160 	bpf_link_free(link);
3161 }
3162 
3163 /* bpf_link_put might be called from atomic context. It needs to be called
3164  * from sleepable context in order to acquire sleeping locks during the process.
3165  */
bpf_link_put(struct bpf_link * link)3166 void bpf_link_put(struct bpf_link *link)
3167 {
3168 	if (!atomic64_dec_and_test(&link->refcnt))
3169 		return;
3170 
3171 	INIT_WORK(&link->work, bpf_link_put_deferred);
3172 	schedule_work(&link->work);
3173 }
3174 EXPORT_SYMBOL(bpf_link_put);
3175 
bpf_link_put_direct(struct bpf_link * link)3176 static void bpf_link_put_direct(struct bpf_link *link)
3177 {
3178 	if (!atomic64_dec_and_test(&link->refcnt))
3179 		return;
3180 	bpf_link_free(link);
3181 }
3182 
bpf_link_release(struct inode * inode,struct file * filp)3183 static int bpf_link_release(struct inode *inode, struct file *filp)
3184 {
3185 	struct bpf_link *link = filp->private_data;
3186 
3187 	bpf_link_put_direct(link);
3188 	return 0;
3189 }
3190 
3191 #ifdef CONFIG_PROC_FS
3192 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3193 #define BPF_MAP_TYPE(_id, _ops)
3194 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3195 static const char *bpf_link_type_strs[] = {
3196 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3197 #include <linux/bpf_types.h>
3198 };
3199 #undef BPF_PROG_TYPE
3200 #undef BPF_MAP_TYPE
3201 #undef BPF_LINK_TYPE
3202 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3203 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3204 {
3205 	const struct bpf_link *link = filp->private_data;
3206 	const struct bpf_prog *prog = link->prog;
3207 	enum bpf_link_type type = link->type;
3208 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3209 
3210 	if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3211 		seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3212 	} else {
3213 		WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3214 		seq_printf(m, "link_type:\t<%u>\n", type);
3215 	}
3216 	seq_printf(m, "link_id:\t%u\n", link->id);
3217 
3218 	if (prog) {
3219 		bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3220 		seq_printf(m,
3221 			   "prog_tag:\t%s\n"
3222 			   "prog_id:\t%u\n",
3223 			   prog_tag,
3224 			   prog->aux->id);
3225 	}
3226 	if (link->ops->show_fdinfo)
3227 		link->ops->show_fdinfo(link, m);
3228 }
3229 #endif
3230 
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3231 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3232 {
3233 	struct bpf_link *link = file->private_data;
3234 
3235 	return link->ops->poll(file, pts);
3236 }
3237 
3238 static const struct file_operations bpf_link_fops = {
3239 #ifdef CONFIG_PROC_FS
3240 	.show_fdinfo	= bpf_link_show_fdinfo,
3241 #endif
3242 	.release	= bpf_link_release,
3243 	.read		= bpf_dummy_read,
3244 	.write		= bpf_dummy_write,
3245 };
3246 
3247 static const struct file_operations bpf_link_fops_poll = {
3248 #ifdef CONFIG_PROC_FS
3249 	.show_fdinfo	= bpf_link_show_fdinfo,
3250 #endif
3251 	.release	= bpf_link_release,
3252 	.read		= bpf_dummy_read,
3253 	.write		= bpf_dummy_write,
3254 	.poll		= bpf_link_poll,
3255 };
3256 
bpf_link_alloc_id(struct bpf_link * link)3257 static int bpf_link_alloc_id(struct bpf_link *link)
3258 {
3259 	int id;
3260 
3261 	idr_preload(GFP_KERNEL);
3262 	spin_lock_bh(&link_idr_lock);
3263 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3264 	spin_unlock_bh(&link_idr_lock);
3265 	idr_preload_end();
3266 
3267 	return id;
3268 }
3269 
3270 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3271  * reserving unused FD and allocating ID from link_idr. This is to be paired
3272  * with bpf_link_settle() to install FD and ID and expose bpf_link to
3273  * user-space, if bpf_link is successfully attached. If not, bpf_link and
3274  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3275  * transient state is passed around in struct bpf_link_primer.
3276  * This is preferred way to create and initialize bpf_link, especially when
3277  * there are complicated and expensive operations in between creating bpf_link
3278  * itself and attaching it to BPF hook. By using bpf_link_prime() and
3279  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3280  * expensive (and potentially failing) roll back operations in a rare case
3281  * that file, FD, or ID can't be allocated.
3282  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3283 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3284 {
3285 	struct file *file;
3286 	int fd, id;
3287 
3288 	fd = get_unused_fd_flags(O_CLOEXEC);
3289 	if (fd < 0)
3290 		return fd;
3291 
3292 
3293 	id = bpf_link_alloc_id(link);
3294 	if (id < 0) {
3295 		put_unused_fd(fd);
3296 		return id;
3297 	}
3298 
3299 	file = anon_inode_getfile("bpf_link",
3300 				  link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3301 				  link, O_CLOEXEC);
3302 	if (IS_ERR(file)) {
3303 		bpf_link_free_id(id);
3304 		put_unused_fd(fd);
3305 		return PTR_ERR(file);
3306 	}
3307 
3308 	primer->link = link;
3309 	primer->file = file;
3310 	primer->fd = fd;
3311 	primer->id = id;
3312 	return 0;
3313 }
3314 
bpf_link_settle(struct bpf_link_primer * primer)3315 int bpf_link_settle(struct bpf_link_primer *primer)
3316 {
3317 	/* make bpf_link fetchable by ID */
3318 	spin_lock_bh(&link_idr_lock);
3319 	primer->link->id = primer->id;
3320 	spin_unlock_bh(&link_idr_lock);
3321 	/* make bpf_link fetchable by FD */
3322 	fd_install(primer->fd, primer->file);
3323 	/* pass through installed FD */
3324 	return primer->fd;
3325 }
3326 
bpf_link_new_fd(struct bpf_link * link)3327 int bpf_link_new_fd(struct bpf_link *link)
3328 {
3329 	return anon_inode_getfd("bpf-link",
3330 				link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3331 				link, O_CLOEXEC);
3332 }
3333 
bpf_link_get_from_fd(u32 ufd)3334 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3335 {
3336 	CLASS(fd, f)(ufd);
3337 	struct bpf_link *link;
3338 
3339 	if (fd_empty(f))
3340 		return ERR_PTR(-EBADF);
3341 	if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3342 		return ERR_PTR(-EINVAL);
3343 
3344 	link = fd_file(f)->private_data;
3345 	bpf_link_inc(link);
3346 	return link;
3347 }
3348 EXPORT_SYMBOL(bpf_link_get_from_fd);
3349 
bpf_tracing_link_release(struct bpf_link * link)3350 static void bpf_tracing_link_release(struct bpf_link *link)
3351 {
3352 	struct bpf_tracing_link *tr_link =
3353 		container_of(link, struct bpf_tracing_link, link.link);
3354 
3355 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3356 						tr_link->trampoline,
3357 						tr_link->tgt_prog));
3358 
3359 	bpf_trampoline_put(tr_link->trampoline);
3360 
3361 	/* tgt_prog is NULL if target is a kernel function */
3362 	if (tr_link->tgt_prog)
3363 		bpf_prog_put(tr_link->tgt_prog);
3364 }
3365 
bpf_tracing_link_dealloc(struct bpf_link * link)3366 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3367 {
3368 	struct bpf_tracing_link *tr_link =
3369 		container_of(link, struct bpf_tracing_link, link.link);
3370 
3371 	kfree(tr_link);
3372 }
3373 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3374 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3375 					 struct seq_file *seq)
3376 {
3377 	struct bpf_tracing_link *tr_link =
3378 		container_of(link, struct bpf_tracing_link, link.link);
3379 	u32 target_btf_id, target_obj_id;
3380 
3381 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3382 				  &target_obj_id, &target_btf_id);
3383 	seq_printf(seq,
3384 		   "attach_type:\t%d\n"
3385 		   "target_obj_id:\t%u\n"
3386 		   "target_btf_id:\t%u\n",
3387 		   tr_link->attach_type,
3388 		   target_obj_id,
3389 		   target_btf_id);
3390 }
3391 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3392 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3393 					   struct bpf_link_info *info)
3394 {
3395 	struct bpf_tracing_link *tr_link =
3396 		container_of(link, struct bpf_tracing_link, link.link);
3397 
3398 	info->tracing.attach_type = tr_link->attach_type;
3399 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3400 				  &info->tracing.target_obj_id,
3401 				  &info->tracing.target_btf_id);
3402 
3403 	return 0;
3404 }
3405 
3406 static const struct bpf_link_ops bpf_tracing_link_lops = {
3407 	.release = bpf_tracing_link_release,
3408 	.dealloc = bpf_tracing_link_dealloc,
3409 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3410 	.fill_link_info = bpf_tracing_link_fill_link_info,
3411 };
3412 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)3413 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3414 				   int tgt_prog_fd,
3415 				   u32 btf_id,
3416 				   u64 bpf_cookie)
3417 {
3418 	struct bpf_link_primer link_primer;
3419 	struct bpf_prog *tgt_prog = NULL;
3420 	struct bpf_trampoline *tr = NULL;
3421 	struct bpf_tracing_link *link;
3422 	u64 key = 0;
3423 	int err;
3424 
3425 	switch (prog->type) {
3426 	case BPF_PROG_TYPE_TRACING:
3427 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3428 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3429 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3430 			err = -EINVAL;
3431 			goto out_put_prog;
3432 		}
3433 		break;
3434 	case BPF_PROG_TYPE_EXT:
3435 		if (prog->expected_attach_type != 0) {
3436 			err = -EINVAL;
3437 			goto out_put_prog;
3438 		}
3439 		break;
3440 	case BPF_PROG_TYPE_LSM:
3441 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3442 			err = -EINVAL;
3443 			goto out_put_prog;
3444 		}
3445 		break;
3446 	default:
3447 		err = -EINVAL;
3448 		goto out_put_prog;
3449 	}
3450 
3451 	if (!!tgt_prog_fd != !!btf_id) {
3452 		err = -EINVAL;
3453 		goto out_put_prog;
3454 	}
3455 
3456 	if (tgt_prog_fd) {
3457 		/*
3458 		 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3459 		 * part would be changed to implement the same for
3460 		 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3461 		 * attach_tracing_prog flag is set.
3462 		 */
3463 		if (prog->type != BPF_PROG_TYPE_EXT) {
3464 			err = -EINVAL;
3465 			goto out_put_prog;
3466 		}
3467 
3468 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3469 		if (IS_ERR(tgt_prog)) {
3470 			err = PTR_ERR(tgt_prog);
3471 			tgt_prog = NULL;
3472 			goto out_put_prog;
3473 		}
3474 
3475 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3476 	}
3477 
3478 	link = kzalloc(sizeof(*link), GFP_USER);
3479 	if (!link) {
3480 		err = -ENOMEM;
3481 		goto out_put_prog;
3482 	}
3483 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3484 		      &bpf_tracing_link_lops, prog);
3485 	link->attach_type = prog->expected_attach_type;
3486 	link->link.cookie = bpf_cookie;
3487 
3488 	mutex_lock(&prog->aux->dst_mutex);
3489 
3490 	/* There are a few possible cases here:
3491 	 *
3492 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3493 	 *   and not yet attached to anything, so we can use the values stored
3494 	 *   in prog->aux
3495 	 *
3496 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3497 	 *   attached to a target and its initial target was cleared (below)
3498 	 *
3499 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3500 	 *   target_btf_id using the link_create API.
3501 	 *
3502 	 * - if tgt_prog == NULL when this function was called using the old
3503 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3504 	 *
3505 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3506 	 *   was detached and is going for re-attachment.
3507 	 *
3508 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3509 	 *   are NULL, then program was already attached and user did not provide
3510 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3511 	 */
3512 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3513 		/*
3514 		 * Allow re-attach for TRACING and LSM programs. If it's
3515 		 * currently linked, bpf_trampoline_link_prog will fail.
3516 		 * EXT programs need to specify tgt_prog_fd, so they
3517 		 * re-attach in separate code path.
3518 		 */
3519 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3520 		    prog->type != BPF_PROG_TYPE_LSM) {
3521 			err = -EINVAL;
3522 			goto out_unlock;
3523 		}
3524 		/* We can allow re-attach only if we have valid attach_btf. */
3525 		if (!prog->aux->attach_btf) {
3526 			err = -EINVAL;
3527 			goto out_unlock;
3528 		}
3529 		btf_id = prog->aux->attach_btf_id;
3530 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3531 	}
3532 
3533 	if (!prog->aux->dst_trampoline ||
3534 	    (key && key != prog->aux->dst_trampoline->key)) {
3535 		/* If there is no saved target, or the specified target is
3536 		 * different from the destination specified at load time, we
3537 		 * need a new trampoline and a check for compatibility
3538 		 */
3539 		struct bpf_attach_target_info tgt_info = {};
3540 
3541 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3542 					      &tgt_info);
3543 		if (err)
3544 			goto out_unlock;
3545 
3546 		if (tgt_info.tgt_mod) {
3547 			module_put(prog->aux->mod);
3548 			prog->aux->mod = tgt_info.tgt_mod;
3549 		}
3550 
3551 		tr = bpf_trampoline_get(key, &tgt_info);
3552 		if (!tr) {
3553 			err = -ENOMEM;
3554 			goto out_unlock;
3555 		}
3556 	} else {
3557 		/* The caller didn't specify a target, or the target was the
3558 		 * same as the destination supplied during program load. This
3559 		 * means we can reuse the trampoline and reference from program
3560 		 * load time, and there is no need to allocate a new one. This
3561 		 * can only happen once for any program, as the saved values in
3562 		 * prog->aux are cleared below.
3563 		 */
3564 		tr = prog->aux->dst_trampoline;
3565 		tgt_prog = prog->aux->dst_prog;
3566 	}
3567 
3568 	err = bpf_link_prime(&link->link.link, &link_primer);
3569 	if (err)
3570 		goto out_unlock;
3571 
3572 	err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3573 	if (err) {
3574 		bpf_link_cleanup(&link_primer);
3575 		link = NULL;
3576 		goto out_unlock;
3577 	}
3578 
3579 	link->tgt_prog = tgt_prog;
3580 	link->trampoline = tr;
3581 
3582 	/* Always clear the trampoline and target prog from prog->aux to make
3583 	 * sure the original attach destination is not kept alive after a
3584 	 * program is (re-)attached to another target.
3585 	 */
3586 	if (prog->aux->dst_prog &&
3587 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3588 		/* got extra prog ref from syscall, or attaching to different prog */
3589 		bpf_prog_put(prog->aux->dst_prog);
3590 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3591 		/* we allocated a new trampoline, so free the old one */
3592 		bpf_trampoline_put(prog->aux->dst_trampoline);
3593 
3594 	prog->aux->dst_prog = NULL;
3595 	prog->aux->dst_trampoline = NULL;
3596 	mutex_unlock(&prog->aux->dst_mutex);
3597 
3598 	return bpf_link_settle(&link_primer);
3599 out_unlock:
3600 	if (tr && tr != prog->aux->dst_trampoline)
3601 		bpf_trampoline_put(tr);
3602 	mutex_unlock(&prog->aux->dst_mutex);
3603 	kfree(link);
3604 out_put_prog:
3605 	if (tgt_prog_fd && tgt_prog)
3606 		bpf_prog_put(tgt_prog);
3607 	return err;
3608 }
3609 
bpf_raw_tp_link_release(struct bpf_link * link)3610 static void bpf_raw_tp_link_release(struct bpf_link *link)
3611 {
3612 	struct bpf_raw_tp_link *raw_tp =
3613 		container_of(link, struct bpf_raw_tp_link, link);
3614 
3615 	bpf_probe_unregister(raw_tp->btp, raw_tp);
3616 	bpf_put_raw_tracepoint(raw_tp->btp);
3617 }
3618 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3619 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3620 {
3621 	struct bpf_raw_tp_link *raw_tp =
3622 		container_of(link, struct bpf_raw_tp_link, link);
3623 
3624 	kfree(raw_tp);
3625 }
3626 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3627 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3628 					struct seq_file *seq)
3629 {
3630 	struct bpf_raw_tp_link *raw_tp_link =
3631 		container_of(link, struct bpf_raw_tp_link, link);
3632 
3633 	seq_printf(seq,
3634 		   "tp_name:\t%s\n",
3635 		   raw_tp_link->btp->tp->name);
3636 }
3637 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3638 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3639 			    u32 len)
3640 {
3641 	if (ulen >= len + 1) {
3642 		if (copy_to_user(ubuf, buf, len + 1))
3643 			return -EFAULT;
3644 	} else {
3645 		char zero = '\0';
3646 
3647 		if (copy_to_user(ubuf, buf, ulen - 1))
3648 			return -EFAULT;
3649 		if (put_user(zero, ubuf + ulen - 1))
3650 			return -EFAULT;
3651 		return -ENOSPC;
3652 	}
3653 
3654 	return 0;
3655 }
3656 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3657 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3658 					  struct bpf_link_info *info)
3659 {
3660 	struct bpf_raw_tp_link *raw_tp_link =
3661 		container_of(link, struct bpf_raw_tp_link, link);
3662 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3663 	const char *tp_name = raw_tp_link->btp->tp->name;
3664 	u32 ulen = info->raw_tracepoint.tp_name_len;
3665 	size_t tp_len = strlen(tp_name);
3666 
3667 	if (!ulen ^ !ubuf)
3668 		return -EINVAL;
3669 
3670 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3671 
3672 	if (!ubuf)
3673 		return 0;
3674 
3675 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3676 }
3677 
3678 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3679 	.release = bpf_raw_tp_link_release,
3680 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3681 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3682 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3683 };
3684 
3685 #ifdef CONFIG_PERF_EVENTS
3686 struct bpf_perf_link {
3687 	struct bpf_link link;
3688 	struct file *perf_file;
3689 };
3690 
bpf_perf_link_release(struct bpf_link * link)3691 static void bpf_perf_link_release(struct bpf_link *link)
3692 {
3693 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3694 	struct perf_event *event = perf_link->perf_file->private_data;
3695 
3696 	perf_event_free_bpf_prog(event);
3697 	fput(perf_link->perf_file);
3698 }
3699 
bpf_perf_link_dealloc(struct bpf_link * link)3700 static void bpf_perf_link_dealloc(struct bpf_link *link)
3701 {
3702 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3703 
3704 	kfree(perf_link);
3705 }
3706 
bpf_perf_link_fill_common(const struct perf_event * event,char __user * uname,u32 * ulenp,u64 * probe_offset,u64 * probe_addr,u32 * fd_type,unsigned long * missed)3707 static int bpf_perf_link_fill_common(const struct perf_event *event,
3708 				     char __user *uname, u32 *ulenp,
3709 				     u64 *probe_offset, u64 *probe_addr,
3710 				     u32 *fd_type, unsigned long *missed)
3711 {
3712 	const char *buf;
3713 	u32 prog_id, ulen;
3714 	size_t len;
3715 	int err;
3716 
3717 	ulen = *ulenp;
3718 	if (!ulen ^ !uname)
3719 		return -EINVAL;
3720 
3721 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3722 				      probe_offset, probe_addr, missed);
3723 	if (err)
3724 		return err;
3725 
3726 	if (buf) {
3727 		len = strlen(buf);
3728 		*ulenp = len + 1;
3729 	} else {
3730 		*ulenp = 1;
3731 	}
3732 	if (!uname)
3733 		return 0;
3734 
3735 	if (buf) {
3736 		err = bpf_copy_to_user(uname, buf, ulen, len);
3737 		if (err)
3738 			return err;
3739 	} else {
3740 		char zero = '\0';
3741 
3742 		if (put_user(zero, uname))
3743 			return -EFAULT;
3744 	}
3745 	return 0;
3746 }
3747 
3748 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3749 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3750 				     struct bpf_link_info *info)
3751 {
3752 	unsigned long missed;
3753 	char __user *uname;
3754 	u64 addr, offset;
3755 	u32 ulen, type;
3756 	int err;
3757 
3758 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3759 	ulen = info->perf_event.kprobe.name_len;
3760 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3761 					&type, &missed);
3762 	if (err)
3763 		return err;
3764 	if (type == BPF_FD_TYPE_KRETPROBE)
3765 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3766 	else
3767 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3768 	info->perf_event.kprobe.name_len = ulen;
3769 	info->perf_event.kprobe.offset = offset;
3770 	info->perf_event.kprobe.missed = missed;
3771 	if (!kallsyms_show_value(current_cred()))
3772 		addr = 0;
3773 	info->perf_event.kprobe.addr = addr;
3774 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3775 	return 0;
3776 }
3777 #endif
3778 
3779 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3780 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3781 				     struct bpf_link_info *info)
3782 {
3783 	char __user *uname;
3784 	u64 addr, offset;
3785 	u32 ulen, type;
3786 	int err;
3787 
3788 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3789 	ulen = info->perf_event.uprobe.name_len;
3790 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3791 					&type, NULL);
3792 	if (err)
3793 		return err;
3794 
3795 	if (type == BPF_FD_TYPE_URETPROBE)
3796 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3797 	else
3798 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3799 	info->perf_event.uprobe.name_len = ulen;
3800 	info->perf_event.uprobe.offset = offset;
3801 	info->perf_event.uprobe.cookie = event->bpf_cookie;
3802 	return 0;
3803 }
3804 #endif
3805 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)3806 static int bpf_perf_link_fill_probe(const struct perf_event *event,
3807 				    struct bpf_link_info *info)
3808 {
3809 #ifdef CONFIG_KPROBE_EVENTS
3810 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
3811 		return bpf_perf_link_fill_kprobe(event, info);
3812 #endif
3813 #ifdef CONFIG_UPROBE_EVENTS
3814 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
3815 		return bpf_perf_link_fill_uprobe(event, info);
3816 #endif
3817 	return -EOPNOTSUPP;
3818 }
3819 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)3820 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
3821 					 struct bpf_link_info *info)
3822 {
3823 	char __user *uname;
3824 	u32 ulen;
3825 	int err;
3826 
3827 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
3828 	ulen = info->perf_event.tracepoint.name_len;
3829 	err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
3830 	if (err)
3831 		return err;
3832 
3833 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
3834 	info->perf_event.tracepoint.name_len = ulen;
3835 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
3836 	return 0;
3837 }
3838 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)3839 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
3840 					 struct bpf_link_info *info)
3841 {
3842 	info->perf_event.event.type = event->attr.type;
3843 	info->perf_event.event.config = event->attr.config;
3844 	info->perf_event.event.cookie = event->bpf_cookie;
3845 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
3846 	return 0;
3847 }
3848 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3849 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
3850 					struct bpf_link_info *info)
3851 {
3852 	struct bpf_perf_link *perf_link;
3853 	const struct perf_event *event;
3854 
3855 	perf_link = container_of(link, struct bpf_perf_link, link);
3856 	event = perf_get_event(perf_link->perf_file);
3857 	if (IS_ERR(event))
3858 		return PTR_ERR(event);
3859 
3860 	switch (event->prog->type) {
3861 	case BPF_PROG_TYPE_PERF_EVENT:
3862 		return bpf_perf_link_fill_perf_event(event, info);
3863 	case BPF_PROG_TYPE_TRACEPOINT:
3864 		return bpf_perf_link_fill_tracepoint(event, info);
3865 	case BPF_PROG_TYPE_KPROBE:
3866 		return bpf_perf_link_fill_probe(event, info);
3867 	default:
3868 		return -EOPNOTSUPP;
3869 	}
3870 }
3871 
3872 static const struct bpf_link_ops bpf_perf_link_lops = {
3873 	.release = bpf_perf_link_release,
3874 	.dealloc = bpf_perf_link_dealloc,
3875 	.fill_link_info = bpf_perf_link_fill_link_info,
3876 };
3877 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3878 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3879 {
3880 	struct bpf_link_primer link_primer;
3881 	struct bpf_perf_link *link;
3882 	struct perf_event *event;
3883 	struct file *perf_file;
3884 	int err;
3885 
3886 	if (attr->link_create.flags)
3887 		return -EINVAL;
3888 
3889 	perf_file = perf_event_get(attr->link_create.target_fd);
3890 	if (IS_ERR(perf_file))
3891 		return PTR_ERR(perf_file);
3892 
3893 	link = kzalloc(sizeof(*link), GFP_USER);
3894 	if (!link) {
3895 		err = -ENOMEM;
3896 		goto out_put_file;
3897 	}
3898 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3899 	link->perf_file = perf_file;
3900 
3901 	err = bpf_link_prime(&link->link, &link_primer);
3902 	if (err) {
3903 		kfree(link);
3904 		goto out_put_file;
3905 	}
3906 
3907 	event = perf_file->private_data;
3908 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3909 	if (err) {
3910 		bpf_link_cleanup(&link_primer);
3911 		goto out_put_file;
3912 	}
3913 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3914 	bpf_prog_inc(prog);
3915 
3916 	return bpf_link_settle(&link_primer);
3917 
3918 out_put_file:
3919 	fput(perf_file);
3920 	return err;
3921 }
3922 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3923 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3924 {
3925 	return -EOPNOTSUPP;
3926 }
3927 #endif /* CONFIG_PERF_EVENTS */
3928 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie)3929 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3930 				  const char __user *user_tp_name, u64 cookie)
3931 {
3932 	struct bpf_link_primer link_primer;
3933 	struct bpf_raw_tp_link *link;
3934 	struct bpf_raw_event_map *btp;
3935 	const char *tp_name;
3936 	char buf[128];
3937 	int err;
3938 
3939 	switch (prog->type) {
3940 	case BPF_PROG_TYPE_TRACING:
3941 	case BPF_PROG_TYPE_EXT:
3942 	case BPF_PROG_TYPE_LSM:
3943 		if (user_tp_name)
3944 			/* The attach point for this category of programs
3945 			 * should be specified via btf_id during program load.
3946 			 */
3947 			return -EINVAL;
3948 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3949 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3950 			tp_name = prog->aux->attach_func_name;
3951 			break;
3952 		}
3953 		return bpf_tracing_prog_attach(prog, 0, 0, 0);
3954 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3955 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3956 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3957 			return -EFAULT;
3958 		buf[sizeof(buf) - 1] = 0;
3959 		tp_name = buf;
3960 		break;
3961 	default:
3962 		return -EINVAL;
3963 	}
3964 
3965 	btp = bpf_get_raw_tracepoint(tp_name);
3966 	if (!btp)
3967 		return -ENOENT;
3968 
3969 	link = kzalloc(sizeof(*link), GFP_USER);
3970 	if (!link) {
3971 		err = -ENOMEM;
3972 		goto out_put_btp;
3973 	}
3974 	bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3975 				&bpf_raw_tp_link_lops, prog,
3976 				tracepoint_is_faultable(btp->tp));
3977 	link->btp = btp;
3978 	link->cookie = cookie;
3979 
3980 	err = bpf_link_prime(&link->link, &link_primer);
3981 	if (err) {
3982 		kfree(link);
3983 		goto out_put_btp;
3984 	}
3985 
3986 	err = bpf_probe_register(link->btp, link);
3987 	if (err) {
3988 		bpf_link_cleanup(&link_primer);
3989 		goto out_put_btp;
3990 	}
3991 
3992 	return bpf_link_settle(&link_primer);
3993 
3994 out_put_btp:
3995 	bpf_put_raw_tracepoint(btp);
3996 	return err;
3997 }
3998 
3999 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4000 
bpf_raw_tracepoint_open(const union bpf_attr * attr)4001 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4002 {
4003 	struct bpf_prog *prog;
4004 	void __user *tp_name;
4005 	__u64 cookie;
4006 	int fd;
4007 
4008 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4009 		return -EINVAL;
4010 
4011 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4012 	if (IS_ERR(prog))
4013 		return PTR_ERR(prog);
4014 
4015 	tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4016 	cookie = attr->raw_tracepoint.cookie;
4017 	fd = bpf_raw_tp_link_attach(prog, tp_name, cookie);
4018 	if (fd < 0)
4019 		bpf_prog_put(prog);
4020 	return fd;
4021 }
4022 
4023 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4024 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4025 {
4026 	switch (attach_type) {
4027 	case BPF_CGROUP_INET_INGRESS:
4028 	case BPF_CGROUP_INET_EGRESS:
4029 		return BPF_PROG_TYPE_CGROUP_SKB;
4030 	case BPF_CGROUP_INET_SOCK_CREATE:
4031 	case BPF_CGROUP_INET_SOCK_RELEASE:
4032 	case BPF_CGROUP_INET4_POST_BIND:
4033 	case BPF_CGROUP_INET6_POST_BIND:
4034 		return BPF_PROG_TYPE_CGROUP_SOCK;
4035 	case BPF_CGROUP_INET4_BIND:
4036 	case BPF_CGROUP_INET6_BIND:
4037 	case BPF_CGROUP_INET4_CONNECT:
4038 	case BPF_CGROUP_INET6_CONNECT:
4039 	case BPF_CGROUP_UNIX_CONNECT:
4040 	case BPF_CGROUP_INET4_GETPEERNAME:
4041 	case BPF_CGROUP_INET6_GETPEERNAME:
4042 	case BPF_CGROUP_UNIX_GETPEERNAME:
4043 	case BPF_CGROUP_INET4_GETSOCKNAME:
4044 	case BPF_CGROUP_INET6_GETSOCKNAME:
4045 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4046 	case BPF_CGROUP_UDP4_SENDMSG:
4047 	case BPF_CGROUP_UDP6_SENDMSG:
4048 	case BPF_CGROUP_UNIX_SENDMSG:
4049 	case BPF_CGROUP_UDP4_RECVMSG:
4050 	case BPF_CGROUP_UDP6_RECVMSG:
4051 	case BPF_CGROUP_UNIX_RECVMSG:
4052 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4053 	case BPF_CGROUP_SOCK_OPS:
4054 		return BPF_PROG_TYPE_SOCK_OPS;
4055 	case BPF_CGROUP_DEVICE:
4056 		return BPF_PROG_TYPE_CGROUP_DEVICE;
4057 	case BPF_SK_MSG_VERDICT:
4058 		return BPF_PROG_TYPE_SK_MSG;
4059 	case BPF_SK_SKB_STREAM_PARSER:
4060 	case BPF_SK_SKB_STREAM_VERDICT:
4061 	case BPF_SK_SKB_VERDICT:
4062 		return BPF_PROG_TYPE_SK_SKB;
4063 	case BPF_LIRC_MODE2:
4064 		return BPF_PROG_TYPE_LIRC_MODE2;
4065 	case BPF_FLOW_DISSECTOR:
4066 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
4067 	case BPF_CGROUP_SYSCTL:
4068 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
4069 	case BPF_CGROUP_GETSOCKOPT:
4070 	case BPF_CGROUP_SETSOCKOPT:
4071 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4072 	case BPF_TRACE_ITER:
4073 	case BPF_TRACE_RAW_TP:
4074 	case BPF_TRACE_FENTRY:
4075 	case BPF_TRACE_FEXIT:
4076 	case BPF_MODIFY_RETURN:
4077 		return BPF_PROG_TYPE_TRACING;
4078 	case BPF_LSM_MAC:
4079 		return BPF_PROG_TYPE_LSM;
4080 	case BPF_SK_LOOKUP:
4081 		return BPF_PROG_TYPE_SK_LOOKUP;
4082 	case BPF_XDP:
4083 		return BPF_PROG_TYPE_XDP;
4084 	case BPF_LSM_CGROUP:
4085 		return BPF_PROG_TYPE_LSM;
4086 	case BPF_TCX_INGRESS:
4087 	case BPF_TCX_EGRESS:
4088 	case BPF_NETKIT_PRIMARY:
4089 	case BPF_NETKIT_PEER:
4090 		return BPF_PROG_TYPE_SCHED_CLS;
4091 	default:
4092 		return BPF_PROG_TYPE_UNSPEC;
4093 	}
4094 }
4095 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4096 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4097 					     enum bpf_attach_type attach_type)
4098 {
4099 	enum bpf_prog_type ptype;
4100 
4101 	switch (prog->type) {
4102 	case BPF_PROG_TYPE_CGROUP_SOCK:
4103 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4104 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4105 	case BPF_PROG_TYPE_SK_LOOKUP:
4106 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4107 	case BPF_PROG_TYPE_CGROUP_SKB:
4108 		if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4109 			/* cg-skb progs can be loaded by unpriv user.
4110 			 * check permissions at attach time.
4111 			 */
4112 			return -EPERM;
4113 
4114 		ptype = attach_type_to_prog_type(attach_type);
4115 		if (prog->type != ptype)
4116 			return -EINVAL;
4117 
4118 		return prog->enforce_expected_attach_type &&
4119 			prog->expected_attach_type != attach_type ?
4120 			-EINVAL : 0;
4121 	case BPF_PROG_TYPE_EXT:
4122 		return 0;
4123 	case BPF_PROG_TYPE_NETFILTER:
4124 		if (attach_type != BPF_NETFILTER)
4125 			return -EINVAL;
4126 		return 0;
4127 	case BPF_PROG_TYPE_PERF_EVENT:
4128 	case BPF_PROG_TYPE_TRACEPOINT:
4129 		if (attach_type != BPF_PERF_EVENT)
4130 			return -EINVAL;
4131 		return 0;
4132 	case BPF_PROG_TYPE_KPROBE:
4133 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4134 		    attach_type != BPF_TRACE_KPROBE_MULTI)
4135 			return -EINVAL;
4136 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4137 		    attach_type != BPF_TRACE_KPROBE_SESSION)
4138 			return -EINVAL;
4139 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4140 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4141 			return -EINVAL;
4142 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4143 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4144 			return -EINVAL;
4145 		if (attach_type != BPF_PERF_EVENT &&
4146 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
4147 		    attach_type != BPF_TRACE_KPROBE_SESSION &&
4148 		    attach_type != BPF_TRACE_UPROBE_MULTI &&
4149 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4150 			return -EINVAL;
4151 		return 0;
4152 	case BPF_PROG_TYPE_SCHED_CLS:
4153 		if (attach_type != BPF_TCX_INGRESS &&
4154 		    attach_type != BPF_TCX_EGRESS &&
4155 		    attach_type != BPF_NETKIT_PRIMARY &&
4156 		    attach_type != BPF_NETKIT_PEER)
4157 			return -EINVAL;
4158 		return 0;
4159 	default:
4160 		ptype = attach_type_to_prog_type(attach_type);
4161 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4162 			return -EINVAL;
4163 		return 0;
4164 	}
4165 }
4166 
4167 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4168 
4169 #define BPF_F_ATTACH_MASK_BASE	\
4170 	(BPF_F_ALLOW_OVERRIDE |	\
4171 	 BPF_F_ALLOW_MULTI |	\
4172 	 BPF_F_REPLACE)
4173 
4174 #define BPF_F_ATTACH_MASK_MPROG	\
4175 	(BPF_F_REPLACE |	\
4176 	 BPF_F_BEFORE |		\
4177 	 BPF_F_AFTER |		\
4178 	 BPF_F_ID |		\
4179 	 BPF_F_LINK)
4180 
bpf_prog_attach(const union bpf_attr * attr)4181 static int bpf_prog_attach(const union bpf_attr *attr)
4182 {
4183 	enum bpf_prog_type ptype;
4184 	struct bpf_prog *prog;
4185 	int ret;
4186 
4187 	if (CHECK_ATTR(BPF_PROG_ATTACH))
4188 		return -EINVAL;
4189 
4190 	ptype = attach_type_to_prog_type(attr->attach_type);
4191 	if (ptype == BPF_PROG_TYPE_UNSPEC)
4192 		return -EINVAL;
4193 	if (bpf_mprog_supported(ptype)) {
4194 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4195 			return -EINVAL;
4196 	} else {
4197 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4198 			return -EINVAL;
4199 		if (attr->relative_fd ||
4200 		    attr->expected_revision)
4201 			return -EINVAL;
4202 	}
4203 
4204 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4205 	if (IS_ERR(prog))
4206 		return PTR_ERR(prog);
4207 
4208 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4209 		bpf_prog_put(prog);
4210 		return -EINVAL;
4211 	}
4212 
4213 	switch (ptype) {
4214 	case BPF_PROG_TYPE_SK_SKB:
4215 	case BPF_PROG_TYPE_SK_MSG:
4216 		ret = sock_map_get_from_fd(attr, prog);
4217 		break;
4218 	case BPF_PROG_TYPE_LIRC_MODE2:
4219 		ret = lirc_prog_attach(attr, prog);
4220 		break;
4221 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4222 		ret = netns_bpf_prog_attach(attr, prog);
4223 		break;
4224 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4225 	case BPF_PROG_TYPE_CGROUP_SKB:
4226 	case BPF_PROG_TYPE_CGROUP_SOCK:
4227 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4228 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4229 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4230 	case BPF_PROG_TYPE_SOCK_OPS:
4231 	case BPF_PROG_TYPE_LSM:
4232 		if (ptype == BPF_PROG_TYPE_LSM &&
4233 		    prog->expected_attach_type != BPF_LSM_CGROUP)
4234 			ret = -EINVAL;
4235 		else
4236 			ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4237 		break;
4238 	case BPF_PROG_TYPE_SCHED_CLS:
4239 		if (attr->attach_type == BPF_TCX_INGRESS ||
4240 		    attr->attach_type == BPF_TCX_EGRESS)
4241 			ret = tcx_prog_attach(attr, prog);
4242 		else
4243 			ret = netkit_prog_attach(attr, prog);
4244 		break;
4245 	default:
4246 		ret = -EINVAL;
4247 	}
4248 
4249 	if (ret)
4250 		bpf_prog_put(prog);
4251 	return ret;
4252 }
4253 
4254 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4255 
bpf_prog_detach(const union bpf_attr * attr)4256 static int bpf_prog_detach(const union bpf_attr *attr)
4257 {
4258 	struct bpf_prog *prog = NULL;
4259 	enum bpf_prog_type ptype;
4260 	int ret;
4261 
4262 	if (CHECK_ATTR(BPF_PROG_DETACH))
4263 		return -EINVAL;
4264 
4265 	ptype = attach_type_to_prog_type(attr->attach_type);
4266 	if (bpf_mprog_supported(ptype)) {
4267 		if (ptype == BPF_PROG_TYPE_UNSPEC)
4268 			return -EINVAL;
4269 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4270 			return -EINVAL;
4271 		if (attr->attach_bpf_fd) {
4272 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4273 			if (IS_ERR(prog))
4274 				return PTR_ERR(prog);
4275 		}
4276 	} else if (attr->attach_flags ||
4277 		   attr->relative_fd ||
4278 		   attr->expected_revision) {
4279 		return -EINVAL;
4280 	}
4281 
4282 	switch (ptype) {
4283 	case BPF_PROG_TYPE_SK_MSG:
4284 	case BPF_PROG_TYPE_SK_SKB:
4285 		ret = sock_map_prog_detach(attr, ptype);
4286 		break;
4287 	case BPF_PROG_TYPE_LIRC_MODE2:
4288 		ret = lirc_prog_detach(attr);
4289 		break;
4290 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4291 		ret = netns_bpf_prog_detach(attr, ptype);
4292 		break;
4293 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4294 	case BPF_PROG_TYPE_CGROUP_SKB:
4295 	case BPF_PROG_TYPE_CGROUP_SOCK:
4296 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4297 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4298 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4299 	case BPF_PROG_TYPE_SOCK_OPS:
4300 	case BPF_PROG_TYPE_LSM:
4301 		ret = cgroup_bpf_prog_detach(attr, ptype);
4302 		break;
4303 	case BPF_PROG_TYPE_SCHED_CLS:
4304 		if (attr->attach_type == BPF_TCX_INGRESS ||
4305 		    attr->attach_type == BPF_TCX_EGRESS)
4306 			ret = tcx_prog_detach(attr, prog);
4307 		else
4308 			ret = netkit_prog_detach(attr, prog);
4309 		break;
4310 	default:
4311 		ret = -EINVAL;
4312 	}
4313 
4314 	if (prog)
4315 		bpf_prog_put(prog);
4316 	return ret;
4317 }
4318 
4319 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4320 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4321 static int bpf_prog_query(const union bpf_attr *attr,
4322 			  union bpf_attr __user *uattr)
4323 {
4324 	if (!bpf_net_capable())
4325 		return -EPERM;
4326 	if (CHECK_ATTR(BPF_PROG_QUERY))
4327 		return -EINVAL;
4328 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4329 		return -EINVAL;
4330 
4331 	switch (attr->query.attach_type) {
4332 	case BPF_CGROUP_INET_INGRESS:
4333 	case BPF_CGROUP_INET_EGRESS:
4334 	case BPF_CGROUP_INET_SOCK_CREATE:
4335 	case BPF_CGROUP_INET_SOCK_RELEASE:
4336 	case BPF_CGROUP_INET4_BIND:
4337 	case BPF_CGROUP_INET6_BIND:
4338 	case BPF_CGROUP_INET4_POST_BIND:
4339 	case BPF_CGROUP_INET6_POST_BIND:
4340 	case BPF_CGROUP_INET4_CONNECT:
4341 	case BPF_CGROUP_INET6_CONNECT:
4342 	case BPF_CGROUP_UNIX_CONNECT:
4343 	case BPF_CGROUP_INET4_GETPEERNAME:
4344 	case BPF_CGROUP_INET6_GETPEERNAME:
4345 	case BPF_CGROUP_UNIX_GETPEERNAME:
4346 	case BPF_CGROUP_INET4_GETSOCKNAME:
4347 	case BPF_CGROUP_INET6_GETSOCKNAME:
4348 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4349 	case BPF_CGROUP_UDP4_SENDMSG:
4350 	case BPF_CGROUP_UDP6_SENDMSG:
4351 	case BPF_CGROUP_UNIX_SENDMSG:
4352 	case BPF_CGROUP_UDP4_RECVMSG:
4353 	case BPF_CGROUP_UDP6_RECVMSG:
4354 	case BPF_CGROUP_UNIX_RECVMSG:
4355 	case BPF_CGROUP_SOCK_OPS:
4356 	case BPF_CGROUP_DEVICE:
4357 	case BPF_CGROUP_SYSCTL:
4358 	case BPF_CGROUP_GETSOCKOPT:
4359 	case BPF_CGROUP_SETSOCKOPT:
4360 	case BPF_LSM_CGROUP:
4361 		return cgroup_bpf_prog_query(attr, uattr);
4362 	case BPF_LIRC_MODE2:
4363 		return lirc_prog_query(attr, uattr);
4364 	case BPF_FLOW_DISSECTOR:
4365 	case BPF_SK_LOOKUP:
4366 		return netns_bpf_prog_query(attr, uattr);
4367 	case BPF_SK_SKB_STREAM_PARSER:
4368 	case BPF_SK_SKB_STREAM_VERDICT:
4369 	case BPF_SK_MSG_VERDICT:
4370 	case BPF_SK_SKB_VERDICT:
4371 		return sock_map_bpf_prog_query(attr, uattr);
4372 	case BPF_TCX_INGRESS:
4373 	case BPF_TCX_EGRESS:
4374 		return tcx_prog_query(attr, uattr);
4375 	case BPF_NETKIT_PRIMARY:
4376 	case BPF_NETKIT_PEER:
4377 		return netkit_prog_query(attr, uattr);
4378 	default:
4379 		return -EINVAL;
4380 	}
4381 }
4382 
4383 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4384 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4385 static int bpf_prog_test_run(const union bpf_attr *attr,
4386 			     union bpf_attr __user *uattr)
4387 {
4388 	struct bpf_prog *prog;
4389 	int ret = -ENOTSUPP;
4390 
4391 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4392 		return -EINVAL;
4393 
4394 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4395 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4396 		return -EINVAL;
4397 
4398 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4399 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4400 		return -EINVAL;
4401 
4402 	prog = bpf_prog_get(attr->test.prog_fd);
4403 	if (IS_ERR(prog))
4404 		return PTR_ERR(prog);
4405 
4406 	if (prog->aux->ops->test_run)
4407 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4408 
4409 	bpf_prog_put(prog);
4410 	return ret;
4411 }
4412 
4413 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4414 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4415 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4416 			       union bpf_attr __user *uattr,
4417 			       struct idr *idr,
4418 			       spinlock_t *lock)
4419 {
4420 	u32 next_id = attr->start_id;
4421 	int err = 0;
4422 
4423 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4424 		return -EINVAL;
4425 
4426 	if (!capable(CAP_SYS_ADMIN))
4427 		return -EPERM;
4428 
4429 	next_id++;
4430 	spin_lock_bh(lock);
4431 	if (!idr_get_next(idr, &next_id))
4432 		err = -ENOENT;
4433 	spin_unlock_bh(lock);
4434 
4435 	if (!err)
4436 		err = put_user(next_id, &uattr->next_id);
4437 
4438 	return err;
4439 }
4440 
bpf_map_get_curr_or_next(u32 * id)4441 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4442 {
4443 	struct bpf_map *map;
4444 
4445 	spin_lock_bh(&map_idr_lock);
4446 again:
4447 	map = idr_get_next(&map_idr, id);
4448 	if (map) {
4449 		map = __bpf_map_inc_not_zero(map, false);
4450 		if (IS_ERR(map)) {
4451 			(*id)++;
4452 			goto again;
4453 		}
4454 	}
4455 	spin_unlock_bh(&map_idr_lock);
4456 
4457 	return map;
4458 }
4459 
bpf_prog_get_curr_or_next(u32 * id)4460 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4461 {
4462 	struct bpf_prog *prog;
4463 
4464 	spin_lock_bh(&prog_idr_lock);
4465 again:
4466 	prog = idr_get_next(&prog_idr, id);
4467 	if (prog) {
4468 		prog = bpf_prog_inc_not_zero(prog);
4469 		if (IS_ERR(prog)) {
4470 			(*id)++;
4471 			goto again;
4472 		}
4473 	}
4474 	spin_unlock_bh(&prog_idr_lock);
4475 
4476 	return prog;
4477 }
4478 
4479 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4480 
bpf_prog_by_id(u32 id)4481 struct bpf_prog *bpf_prog_by_id(u32 id)
4482 {
4483 	struct bpf_prog *prog;
4484 
4485 	if (!id)
4486 		return ERR_PTR(-ENOENT);
4487 
4488 	spin_lock_bh(&prog_idr_lock);
4489 	prog = idr_find(&prog_idr, id);
4490 	if (prog)
4491 		prog = bpf_prog_inc_not_zero(prog);
4492 	else
4493 		prog = ERR_PTR(-ENOENT);
4494 	spin_unlock_bh(&prog_idr_lock);
4495 	return prog;
4496 }
4497 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4498 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4499 {
4500 	struct bpf_prog *prog;
4501 	u32 id = attr->prog_id;
4502 	int fd;
4503 
4504 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4505 		return -EINVAL;
4506 
4507 	if (!capable(CAP_SYS_ADMIN))
4508 		return -EPERM;
4509 
4510 	prog = bpf_prog_by_id(id);
4511 	if (IS_ERR(prog))
4512 		return PTR_ERR(prog);
4513 
4514 	fd = bpf_prog_new_fd(prog);
4515 	if (fd < 0)
4516 		bpf_prog_put(prog);
4517 
4518 	return fd;
4519 }
4520 
4521 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4522 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4523 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4524 {
4525 	struct bpf_map *map;
4526 	u32 id = attr->map_id;
4527 	int f_flags;
4528 	int fd;
4529 
4530 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4531 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4532 		return -EINVAL;
4533 
4534 	if (!capable(CAP_SYS_ADMIN))
4535 		return -EPERM;
4536 
4537 	f_flags = bpf_get_file_flag(attr->open_flags);
4538 	if (f_flags < 0)
4539 		return f_flags;
4540 
4541 	spin_lock_bh(&map_idr_lock);
4542 	map = idr_find(&map_idr, id);
4543 	if (map)
4544 		map = __bpf_map_inc_not_zero(map, true);
4545 	else
4546 		map = ERR_PTR(-ENOENT);
4547 	spin_unlock_bh(&map_idr_lock);
4548 
4549 	if (IS_ERR(map))
4550 		return PTR_ERR(map);
4551 
4552 	fd = bpf_map_new_fd(map, f_flags);
4553 	if (fd < 0)
4554 		bpf_map_put_with_uref(map);
4555 
4556 	return fd;
4557 }
4558 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4559 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4560 					      unsigned long addr, u32 *off,
4561 					      u32 *type)
4562 {
4563 	const struct bpf_map *map;
4564 	int i;
4565 
4566 	mutex_lock(&prog->aux->used_maps_mutex);
4567 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4568 		map = prog->aux->used_maps[i];
4569 		if (map == (void *)addr) {
4570 			*type = BPF_PSEUDO_MAP_FD;
4571 			goto out;
4572 		}
4573 		if (!map->ops->map_direct_value_meta)
4574 			continue;
4575 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4576 			*type = BPF_PSEUDO_MAP_VALUE;
4577 			goto out;
4578 		}
4579 	}
4580 	map = NULL;
4581 
4582 out:
4583 	mutex_unlock(&prog->aux->used_maps_mutex);
4584 	return map;
4585 }
4586 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4587 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4588 					      const struct cred *f_cred)
4589 {
4590 	const struct bpf_map *map;
4591 	struct bpf_insn *insns;
4592 	u32 off, type;
4593 	u64 imm;
4594 	u8 code;
4595 	int i;
4596 
4597 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4598 			GFP_USER);
4599 	if (!insns)
4600 		return insns;
4601 
4602 	for (i = 0; i < prog->len; i++) {
4603 		code = insns[i].code;
4604 
4605 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4606 			insns[i].code = BPF_JMP | BPF_CALL;
4607 			insns[i].imm = BPF_FUNC_tail_call;
4608 			/* fall-through */
4609 		}
4610 		if (code == (BPF_JMP | BPF_CALL) ||
4611 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4612 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4613 				insns[i].code = BPF_JMP | BPF_CALL;
4614 			if (!bpf_dump_raw_ok(f_cred))
4615 				insns[i].imm = 0;
4616 			continue;
4617 		}
4618 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4619 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4620 			continue;
4621 		}
4622 
4623 		if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4624 		     BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4625 			insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4626 			continue;
4627 		}
4628 
4629 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4630 			continue;
4631 
4632 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4633 		map = bpf_map_from_imm(prog, imm, &off, &type);
4634 		if (map) {
4635 			insns[i].src_reg = type;
4636 			insns[i].imm = map->id;
4637 			insns[i + 1].imm = off;
4638 			continue;
4639 		}
4640 	}
4641 
4642 	return insns;
4643 }
4644 
set_info_rec_size(struct bpf_prog_info * info)4645 static int set_info_rec_size(struct bpf_prog_info *info)
4646 {
4647 	/*
4648 	 * Ensure info.*_rec_size is the same as kernel expected size
4649 	 *
4650 	 * or
4651 	 *
4652 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4653 	 * zero.  In this case, the kernel will set the expected
4654 	 * _rec_size back to the info.
4655 	 */
4656 
4657 	if ((info->nr_func_info || info->func_info_rec_size) &&
4658 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4659 		return -EINVAL;
4660 
4661 	if ((info->nr_line_info || info->line_info_rec_size) &&
4662 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
4663 		return -EINVAL;
4664 
4665 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4666 	    info->jited_line_info_rec_size != sizeof(__u64))
4667 		return -EINVAL;
4668 
4669 	info->func_info_rec_size = sizeof(struct bpf_func_info);
4670 	info->line_info_rec_size = sizeof(struct bpf_line_info);
4671 	info->jited_line_info_rec_size = sizeof(__u64);
4672 
4673 	return 0;
4674 }
4675 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4676 static int bpf_prog_get_info_by_fd(struct file *file,
4677 				   struct bpf_prog *prog,
4678 				   const union bpf_attr *attr,
4679 				   union bpf_attr __user *uattr)
4680 {
4681 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4682 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4683 	struct bpf_prog_info info;
4684 	u32 info_len = attr->info.info_len;
4685 	struct bpf_prog_kstats stats;
4686 	char __user *uinsns;
4687 	u32 ulen;
4688 	int err;
4689 
4690 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4691 	if (err)
4692 		return err;
4693 	info_len = min_t(u32, sizeof(info), info_len);
4694 
4695 	memset(&info, 0, sizeof(info));
4696 	if (copy_from_user(&info, uinfo, info_len))
4697 		return -EFAULT;
4698 
4699 	info.type = prog->type;
4700 	info.id = prog->aux->id;
4701 	info.load_time = prog->aux->load_time;
4702 	info.created_by_uid = from_kuid_munged(current_user_ns(),
4703 					       prog->aux->user->uid);
4704 	info.gpl_compatible = prog->gpl_compatible;
4705 
4706 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
4707 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
4708 
4709 	mutex_lock(&prog->aux->used_maps_mutex);
4710 	ulen = info.nr_map_ids;
4711 	info.nr_map_ids = prog->aux->used_map_cnt;
4712 	ulen = min_t(u32, info.nr_map_ids, ulen);
4713 	if (ulen) {
4714 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
4715 		u32 i;
4716 
4717 		for (i = 0; i < ulen; i++)
4718 			if (put_user(prog->aux->used_maps[i]->id,
4719 				     &user_map_ids[i])) {
4720 				mutex_unlock(&prog->aux->used_maps_mutex);
4721 				return -EFAULT;
4722 			}
4723 	}
4724 	mutex_unlock(&prog->aux->used_maps_mutex);
4725 
4726 	err = set_info_rec_size(&info);
4727 	if (err)
4728 		return err;
4729 
4730 	bpf_prog_get_stats(prog, &stats);
4731 	info.run_time_ns = stats.nsecs;
4732 	info.run_cnt = stats.cnt;
4733 	info.recursion_misses = stats.misses;
4734 
4735 	info.verified_insns = prog->aux->verified_insns;
4736 
4737 	if (!bpf_capable()) {
4738 		info.jited_prog_len = 0;
4739 		info.xlated_prog_len = 0;
4740 		info.nr_jited_ksyms = 0;
4741 		info.nr_jited_func_lens = 0;
4742 		info.nr_func_info = 0;
4743 		info.nr_line_info = 0;
4744 		info.nr_jited_line_info = 0;
4745 		goto done;
4746 	}
4747 
4748 	ulen = info.xlated_prog_len;
4749 	info.xlated_prog_len = bpf_prog_insn_size(prog);
4750 	if (info.xlated_prog_len && ulen) {
4751 		struct bpf_insn *insns_sanitized;
4752 		bool fault;
4753 
4754 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
4755 			info.xlated_prog_insns = 0;
4756 			goto done;
4757 		}
4758 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
4759 		if (!insns_sanitized)
4760 			return -ENOMEM;
4761 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
4762 		ulen = min_t(u32, info.xlated_prog_len, ulen);
4763 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
4764 		kfree(insns_sanitized);
4765 		if (fault)
4766 			return -EFAULT;
4767 	}
4768 
4769 	if (bpf_prog_is_offloaded(prog->aux)) {
4770 		err = bpf_prog_offload_info_fill(&info, prog);
4771 		if (err)
4772 			return err;
4773 		goto done;
4774 	}
4775 
4776 	/* NOTE: the following code is supposed to be skipped for offload.
4777 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
4778 	 * for offload.
4779 	 */
4780 	ulen = info.jited_prog_len;
4781 	if (prog->aux->func_cnt) {
4782 		u32 i;
4783 
4784 		info.jited_prog_len = 0;
4785 		for (i = 0; i < prog->aux->func_cnt; i++)
4786 			info.jited_prog_len += prog->aux->func[i]->jited_len;
4787 	} else {
4788 		info.jited_prog_len = prog->jited_len;
4789 	}
4790 
4791 	if (info.jited_prog_len && ulen) {
4792 		if (bpf_dump_raw_ok(file->f_cred)) {
4793 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
4794 			ulen = min_t(u32, info.jited_prog_len, ulen);
4795 
4796 			/* for multi-function programs, copy the JITed
4797 			 * instructions for all the functions
4798 			 */
4799 			if (prog->aux->func_cnt) {
4800 				u32 len, free, i;
4801 				u8 *img;
4802 
4803 				free = ulen;
4804 				for (i = 0; i < prog->aux->func_cnt; i++) {
4805 					len = prog->aux->func[i]->jited_len;
4806 					len = min_t(u32, len, free);
4807 					img = (u8 *) prog->aux->func[i]->bpf_func;
4808 					if (copy_to_user(uinsns, img, len))
4809 						return -EFAULT;
4810 					uinsns += len;
4811 					free -= len;
4812 					if (!free)
4813 						break;
4814 				}
4815 			} else {
4816 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
4817 					return -EFAULT;
4818 			}
4819 		} else {
4820 			info.jited_prog_insns = 0;
4821 		}
4822 	}
4823 
4824 	ulen = info.nr_jited_ksyms;
4825 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4826 	if (ulen) {
4827 		if (bpf_dump_raw_ok(file->f_cred)) {
4828 			unsigned long ksym_addr;
4829 			u64 __user *user_ksyms;
4830 			u32 i;
4831 
4832 			/* copy the address of the kernel symbol
4833 			 * corresponding to each function
4834 			 */
4835 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4836 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4837 			if (prog->aux->func_cnt) {
4838 				for (i = 0; i < ulen; i++) {
4839 					ksym_addr = (unsigned long)
4840 						prog->aux->func[i]->bpf_func;
4841 					if (put_user((u64) ksym_addr,
4842 						     &user_ksyms[i]))
4843 						return -EFAULT;
4844 				}
4845 			} else {
4846 				ksym_addr = (unsigned long) prog->bpf_func;
4847 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
4848 					return -EFAULT;
4849 			}
4850 		} else {
4851 			info.jited_ksyms = 0;
4852 		}
4853 	}
4854 
4855 	ulen = info.nr_jited_func_lens;
4856 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4857 	if (ulen) {
4858 		if (bpf_dump_raw_ok(file->f_cred)) {
4859 			u32 __user *user_lens;
4860 			u32 func_len, i;
4861 
4862 			/* copy the JITed image lengths for each function */
4863 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4864 			user_lens = u64_to_user_ptr(info.jited_func_lens);
4865 			if (prog->aux->func_cnt) {
4866 				for (i = 0; i < ulen; i++) {
4867 					func_len =
4868 						prog->aux->func[i]->jited_len;
4869 					if (put_user(func_len, &user_lens[i]))
4870 						return -EFAULT;
4871 				}
4872 			} else {
4873 				func_len = prog->jited_len;
4874 				if (put_user(func_len, &user_lens[0]))
4875 					return -EFAULT;
4876 			}
4877 		} else {
4878 			info.jited_func_lens = 0;
4879 		}
4880 	}
4881 
4882 	if (prog->aux->btf)
4883 		info.btf_id = btf_obj_id(prog->aux->btf);
4884 	info.attach_btf_id = prog->aux->attach_btf_id;
4885 	if (attach_btf)
4886 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
4887 
4888 	ulen = info.nr_func_info;
4889 	info.nr_func_info = prog->aux->func_info_cnt;
4890 	if (info.nr_func_info && ulen) {
4891 		char __user *user_finfo;
4892 
4893 		user_finfo = u64_to_user_ptr(info.func_info);
4894 		ulen = min_t(u32, info.nr_func_info, ulen);
4895 		if (copy_to_user(user_finfo, prog->aux->func_info,
4896 				 info.func_info_rec_size * ulen))
4897 			return -EFAULT;
4898 	}
4899 
4900 	ulen = info.nr_line_info;
4901 	info.nr_line_info = prog->aux->nr_linfo;
4902 	if (info.nr_line_info && ulen) {
4903 		__u8 __user *user_linfo;
4904 
4905 		user_linfo = u64_to_user_ptr(info.line_info);
4906 		ulen = min_t(u32, info.nr_line_info, ulen);
4907 		if (copy_to_user(user_linfo, prog->aux->linfo,
4908 				 info.line_info_rec_size * ulen))
4909 			return -EFAULT;
4910 	}
4911 
4912 	ulen = info.nr_jited_line_info;
4913 	if (prog->aux->jited_linfo)
4914 		info.nr_jited_line_info = prog->aux->nr_linfo;
4915 	else
4916 		info.nr_jited_line_info = 0;
4917 	if (info.nr_jited_line_info && ulen) {
4918 		if (bpf_dump_raw_ok(file->f_cred)) {
4919 			unsigned long line_addr;
4920 			__u64 __user *user_linfo;
4921 			u32 i;
4922 
4923 			user_linfo = u64_to_user_ptr(info.jited_line_info);
4924 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
4925 			for (i = 0; i < ulen; i++) {
4926 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
4927 				if (put_user((__u64)line_addr, &user_linfo[i]))
4928 					return -EFAULT;
4929 			}
4930 		} else {
4931 			info.jited_line_info = 0;
4932 		}
4933 	}
4934 
4935 	ulen = info.nr_prog_tags;
4936 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4937 	if (ulen) {
4938 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4939 		u32 i;
4940 
4941 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
4942 		ulen = min_t(u32, info.nr_prog_tags, ulen);
4943 		if (prog->aux->func_cnt) {
4944 			for (i = 0; i < ulen; i++) {
4945 				if (copy_to_user(user_prog_tags[i],
4946 						 prog->aux->func[i]->tag,
4947 						 BPF_TAG_SIZE))
4948 					return -EFAULT;
4949 			}
4950 		} else {
4951 			if (copy_to_user(user_prog_tags[0],
4952 					 prog->tag, BPF_TAG_SIZE))
4953 				return -EFAULT;
4954 		}
4955 	}
4956 
4957 done:
4958 	if (copy_to_user(uinfo, &info, info_len) ||
4959 	    put_user(info_len, &uattr->info.info_len))
4960 		return -EFAULT;
4961 
4962 	return 0;
4963 }
4964 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4965 static int bpf_map_get_info_by_fd(struct file *file,
4966 				  struct bpf_map *map,
4967 				  const union bpf_attr *attr,
4968 				  union bpf_attr __user *uattr)
4969 {
4970 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4971 	struct bpf_map_info info;
4972 	u32 info_len = attr->info.info_len;
4973 	int err;
4974 
4975 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4976 	if (err)
4977 		return err;
4978 	info_len = min_t(u32, sizeof(info), info_len);
4979 
4980 	memset(&info, 0, sizeof(info));
4981 	info.type = map->map_type;
4982 	info.id = map->id;
4983 	info.key_size = map->key_size;
4984 	info.value_size = map->value_size;
4985 	info.max_entries = map->max_entries;
4986 	info.map_flags = map->map_flags;
4987 	info.map_extra = map->map_extra;
4988 	memcpy(info.name, map->name, sizeof(map->name));
4989 
4990 	if (map->btf) {
4991 		info.btf_id = btf_obj_id(map->btf);
4992 		info.btf_key_type_id = map->btf_key_type_id;
4993 		info.btf_value_type_id = map->btf_value_type_id;
4994 	}
4995 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
4996 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
4997 		bpf_map_struct_ops_info_fill(&info, map);
4998 
4999 	if (bpf_map_is_offloaded(map)) {
5000 		err = bpf_map_offload_info_fill(&info, map);
5001 		if (err)
5002 			return err;
5003 	}
5004 
5005 	if (copy_to_user(uinfo, &info, info_len) ||
5006 	    put_user(info_len, &uattr->info.info_len))
5007 		return -EFAULT;
5008 
5009 	return 0;
5010 }
5011 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5012 static int bpf_btf_get_info_by_fd(struct file *file,
5013 				  struct btf *btf,
5014 				  const union bpf_attr *attr,
5015 				  union bpf_attr __user *uattr)
5016 {
5017 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5018 	u32 info_len = attr->info.info_len;
5019 	int err;
5020 
5021 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5022 	if (err)
5023 		return err;
5024 
5025 	return btf_get_info_by_fd(btf, attr, uattr);
5026 }
5027 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5028 static int bpf_link_get_info_by_fd(struct file *file,
5029 				  struct bpf_link *link,
5030 				  const union bpf_attr *attr,
5031 				  union bpf_attr __user *uattr)
5032 {
5033 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5034 	struct bpf_link_info info;
5035 	u32 info_len = attr->info.info_len;
5036 	int err;
5037 
5038 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5039 	if (err)
5040 		return err;
5041 	info_len = min_t(u32, sizeof(info), info_len);
5042 
5043 	memset(&info, 0, sizeof(info));
5044 	if (copy_from_user(&info, uinfo, info_len))
5045 		return -EFAULT;
5046 
5047 	info.type = link->type;
5048 	info.id = link->id;
5049 	if (link->prog)
5050 		info.prog_id = link->prog->aux->id;
5051 
5052 	if (link->ops->fill_link_info) {
5053 		err = link->ops->fill_link_info(link, &info);
5054 		if (err)
5055 			return err;
5056 	}
5057 
5058 	if (copy_to_user(uinfo, &info, info_len) ||
5059 	    put_user(info_len, &uattr->info.info_len))
5060 		return -EFAULT;
5061 
5062 	return 0;
5063 }
5064 
5065 
5066 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5067 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5068 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5069 				  union bpf_attr __user *uattr)
5070 {
5071 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5072 		return -EINVAL;
5073 
5074 	CLASS(fd, f)(attr->info.bpf_fd);
5075 	if (fd_empty(f))
5076 		return -EBADFD;
5077 
5078 	if (fd_file(f)->f_op == &bpf_prog_fops)
5079 		return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5080 					      uattr);
5081 	else if (fd_file(f)->f_op == &bpf_map_fops)
5082 		return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5083 					     uattr);
5084 	else if (fd_file(f)->f_op == &btf_fops)
5085 		return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5086 	else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5087 		return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5088 					      attr, uattr);
5089 	return -EINVAL;
5090 }
5091 
5092 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5093 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5094 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5095 {
5096 	struct bpf_token *token = NULL;
5097 
5098 	if (CHECK_ATTR(BPF_BTF_LOAD))
5099 		return -EINVAL;
5100 
5101 	if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5102 		return -EINVAL;
5103 
5104 	if (attr->btf_flags & BPF_F_TOKEN_FD) {
5105 		token = bpf_token_get_from_fd(attr->btf_token_fd);
5106 		if (IS_ERR(token))
5107 			return PTR_ERR(token);
5108 		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5109 			bpf_token_put(token);
5110 			token = NULL;
5111 		}
5112 	}
5113 
5114 	if (!bpf_token_capable(token, CAP_BPF)) {
5115 		bpf_token_put(token);
5116 		return -EPERM;
5117 	}
5118 
5119 	bpf_token_put(token);
5120 
5121 	return btf_new_fd(attr, uattr, uattr_size);
5122 }
5123 
5124 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
5125 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5126 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5127 {
5128 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5129 		return -EINVAL;
5130 
5131 	if (!capable(CAP_SYS_ADMIN))
5132 		return -EPERM;
5133 
5134 	return btf_get_fd_by_id(attr->btf_id);
5135 }
5136 
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)5137 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5138 				    union bpf_attr __user *uattr,
5139 				    u32 prog_id, u32 fd_type,
5140 				    const char *buf, u64 probe_offset,
5141 				    u64 probe_addr)
5142 {
5143 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5144 	u32 len = buf ? strlen(buf) : 0, input_len;
5145 	int err = 0;
5146 
5147 	if (put_user(len, &uattr->task_fd_query.buf_len))
5148 		return -EFAULT;
5149 	input_len = attr->task_fd_query.buf_len;
5150 	if (input_len && ubuf) {
5151 		if (!len) {
5152 			/* nothing to copy, just make ubuf NULL terminated */
5153 			char zero = '\0';
5154 
5155 			if (put_user(zero, ubuf))
5156 				return -EFAULT;
5157 		} else if (input_len >= len + 1) {
5158 			/* ubuf can hold the string with NULL terminator */
5159 			if (copy_to_user(ubuf, buf, len + 1))
5160 				return -EFAULT;
5161 		} else {
5162 			/* ubuf cannot hold the string with NULL terminator,
5163 			 * do a partial copy with NULL terminator.
5164 			 */
5165 			char zero = '\0';
5166 
5167 			err = -ENOSPC;
5168 			if (copy_to_user(ubuf, buf, input_len - 1))
5169 				return -EFAULT;
5170 			if (put_user(zero, ubuf + input_len - 1))
5171 				return -EFAULT;
5172 		}
5173 	}
5174 
5175 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5176 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5177 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5178 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5179 		return -EFAULT;
5180 
5181 	return err;
5182 }
5183 
5184 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5185 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5186 static int bpf_task_fd_query(const union bpf_attr *attr,
5187 			     union bpf_attr __user *uattr)
5188 {
5189 	pid_t pid = attr->task_fd_query.pid;
5190 	u32 fd = attr->task_fd_query.fd;
5191 	const struct perf_event *event;
5192 	struct task_struct *task;
5193 	struct file *file;
5194 	int err;
5195 
5196 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5197 		return -EINVAL;
5198 
5199 	if (!capable(CAP_SYS_ADMIN))
5200 		return -EPERM;
5201 
5202 	if (attr->task_fd_query.flags != 0)
5203 		return -EINVAL;
5204 
5205 	rcu_read_lock();
5206 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5207 	rcu_read_unlock();
5208 	if (!task)
5209 		return -ENOENT;
5210 
5211 	err = 0;
5212 	file = fget_task(task, fd);
5213 	put_task_struct(task);
5214 	if (!file)
5215 		return -EBADF;
5216 
5217 	if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5218 		struct bpf_link *link = file->private_data;
5219 
5220 		if (link->ops == &bpf_raw_tp_link_lops) {
5221 			struct bpf_raw_tp_link *raw_tp =
5222 				container_of(link, struct bpf_raw_tp_link, link);
5223 			struct bpf_raw_event_map *btp = raw_tp->btp;
5224 
5225 			err = bpf_task_fd_query_copy(attr, uattr,
5226 						     raw_tp->link.prog->aux->id,
5227 						     BPF_FD_TYPE_RAW_TRACEPOINT,
5228 						     btp->tp->name, 0, 0);
5229 			goto put_file;
5230 		}
5231 		goto out_not_supp;
5232 	}
5233 
5234 	event = perf_get_event(file);
5235 	if (!IS_ERR(event)) {
5236 		u64 probe_offset, probe_addr;
5237 		u32 prog_id, fd_type;
5238 		const char *buf;
5239 
5240 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5241 					      &buf, &probe_offset,
5242 					      &probe_addr, NULL);
5243 		if (!err)
5244 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5245 						     fd_type, buf,
5246 						     probe_offset,
5247 						     probe_addr);
5248 		goto put_file;
5249 	}
5250 
5251 out_not_supp:
5252 	err = -ENOTSUPP;
5253 put_file:
5254 	fput(file);
5255 	return err;
5256 }
5257 
5258 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5259 
5260 #define BPF_DO_BATCH(fn, ...)			\
5261 	do {					\
5262 		if (!fn) {			\
5263 			err = -ENOTSUPP;	\
5264 			goto err_put;		\
5265 		}				\
5266 		err = fn(__VA_ARGS__);		\
5267 	} while (0)
5268 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5269 static int bpf_map_do_batch(const union bpf_attr *attr,
5270 			    union bpf_attr __user *uattr,
5271 			    int cmd)
5272 {
5273 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
5274 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5275 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5276 	struct bpf_map *map;
5277 	int err;
5278 
5279 	if (CHECK_ATTR(BPF_MAP_BATCH))
5280 		return -EINVAL;
5281 
5282 	CLASS(fd, f)(attr->batch.map_fd);
5283 
5284 	map = __bpf_map_get(f);
5285 	if (IS_ERR(map))
5286 		return PTR_ERR(map);
5287 	if (has_write)
5288 		bpf_map_write_active_inc(map);
5289 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5290 		err = -EPERM;
5291 		goto err_put;
5292 	}
5293 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5294 		err = -EPERM;
5295 		goto err_put;
5296 	}
5297 
5298 	if (cmd == BPF_MAP_LOOKUP_BATCH)
5299 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5300 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5301 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5302 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5303 		BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5304 	else
5305 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5306 err_put:
5307 	if (has_write) {
5308 		maybe_wait_bpf_programs(map);
5309 		bpf_map_write_active_dec(map);
5310 	}
5311 	return err;
5312 }
5313 
5314 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5315 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5316 {
5317 	struct bpf_prog *prog;
5318 	int ret;
5319 
5320 	if (CHECK_ATTR(BPF_LINK_CREATE))
5321 		return -EINVAL;
5322 
5323 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5324 		return bpf_struct_ops_link_create(attr);
5325 
5326 	prog = bpf_prog_get(attr->link_create.prog_fd);
5327 	if (IS_ERR(prog))
5328 		return PTR_ERR(prog);
5329 
5330 	ret = bpf_prog_attach_check_attach_type(prog,
5331 						attr->link_create.attach_type);
5332 	if (ret)
5333 		goto out;
5334 
5335 	switch (prog->type) {
5336 	case BPF_PROG_TYPE_CGROUP_SKB:
5337 	case BPF_PROG_TYPE_CGROUP_SOCK:
5338 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5339 	case BPF_PROG_TYPE_SOCK_OPS:
5340 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5341 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5342 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5343 		ret = cgroup_bpf_link_attach(attr, prog);
5344 		break;
5345 	case BPF_PROG_TYPE_EXT:
5346 		ret = bpf_tracing_prog_attach(prog,
5347 					      attr->link_create.target_fd,
5348 					      attr->link_create.target_btf_id,
5349 					      attr->link_create.tracing.cookie);
5350 		break;
5351 	case BPF_PROG_TYPE_LSM:
5352 	case BPF_PROG_TYPE_TRACING:
5353 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5354 			ret = -EINVAL;
5355 			goto out;
5356 		}
5357 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5358 			ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie);
5359 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5360 			ret = bpf_iter_link_attach(attr, uattr, prog);
5361 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5362 			ret = cgroup_bpf_link_attach(attr, prog);
5363 		else
5364 			ret = bpf_tracing_prog_attach(prog,
5365 						      attr->link_create.target_fd,
5366 						      attr->link_create.target_btf_id,
5367 						      attr->link_create.tracing.cookie);
5368 		break;
5369 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5370 	case BPF_PROG_TYPE_SK_LOOKUP:
5371 		ret = netns_bpf_link_create(attr, prog);
5372 		break;
5373 	case BPF_PROG_TYPE_SK_MSG:
5374 	case BPF_PROG_TYPE_SK_SKB:
5375 		ret = sock_map_link_create(attr, prog);
5376 		break;
5377 #ifdef CONFIG_NET
5378 	case BPF_PROG_TYPE_XDP:
5379 		ret = bpf_xdp_link_attach(attr, prog);
5380 		break;
5381 	case BPF_PROG_TYPE_SCHED_CLS:
5382 		if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5383 		    attr->link_create.attach_type == BPF_TCX_EGRESS)
5384 			ret = tcx_link_attach(attr, prog);
5385 		else
5386 			ret = netkit_link_attach(attr, prog);
5387 		break;
5388 	case BPF_PROG_TYPE_NETFILTER:
5389 		ret = bpf_nf_link_attach(attr, prog);
5390 		break;
5391 #endif
5392 	case BPF_PROG_TYPE_PERF_EVENT:
5393 	case BPF_PROG_TYPE_TRACEPOINT:
5394 		ret = bpf_perf_link_attach(attr, prog);
5395 		break;
5396 	case BPF_PROG_TYPE_KPROBE:
5397 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5398 			ret = bpf_perf_link_attach(attr, prog);
5399 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5400 			 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5401 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5402 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5403 			 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5404 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5405 		break;
5406 	default:
5407 		ret = -EINVAL;
5408 	}
5409 
5410 out:
5411 	if (ret < 0)
5412 		bpf_prog_put(prog);
5413 	return ret;
5414 }
5415 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5416 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5417 {
5418 	struct bpf_map *new_map, *old_map = NULL;
5419 	int ret;
5420 
5421 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5422 	if (IS_ERR(new_map))
5423 		return PTR_ERR(new_map);
5424 
5425 	if (attr->link_update.flags & BPF_F_REPLACE) {
5426 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5427 		if (IS_ERR(old_map)) {
5428 			ret = PTR_ERR(old_map);
5429 			goto out_put;
5430 		}
5431 	} else if (attr->link_update.old_map_fd) {
5432 		ret = -EINVAL;
5433 		goto out_put;
5434 	}
5435 
5436 	ret = link->ops->update_map(link, new_map, old_map);
5437 
5438 	if (old_map)
5439 		bpf_map_put(old_map);
5440 out_put:
5441 	bpf_map_put(new_map);
5442 	return ret;
5443 }
5444 
5445 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5446 
link_update(union bpf_attr * attr)5447 static int link_update(union bpf_attr *attr)
5448 {
5449 	struct bpf_prog *old_prog = NULL, *new_prog;
5450 	struct bpf_link *link;
5451 	u32 flags;
5452 	int ret;
5453 
5454 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5455 		return -EINVAL;
5456 
5457 	flags = attr->link_update.flags;
5458 	if (flags & ~BPF_F_REPLACE)
5459 		return -EINVAL;
5460 
5461 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5462 	if (IS_ERR(link))
5463 		return PTR_ERR(link);
5464 
5465 	if (link->ops->update_map) {
5466 		ret = link_update_map(link, attr);
5467 		goto out_put_link;
5468 	}
5469 
5470 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5471 	if (IS_ERR(new_prog)) {
5472 		ret = PTR_ERR(new_prog);
5473 		goto out_put_link;
5474 	}
5475 
5476 	if (flags & BPF_F_REPLACE) {
5477 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5478 		if (IS_ERR(old_prog)) {
5479 			ret = PTR_ERR(old_prog);
5480 			old_prog = NULL;
5481 			goto out_put_progs;
5482 		}
5483 	} else if (attr->link_update.old_prog_fd) {
5484 		ret = -EINVAL;
5485 		goto out_put_progs;
5486 	}
5487 
5488 	if (link->ops->update_prog)
5489 		ret = link->ops->update_prog(link, new_prog, old_prog);
5490 	else
5491 		ret = -EINVAL;
5492 
5493 out_put_progs:
5494 	if (old_prog)
5495 		bpf_prog_put(old_prog);
5496 	if (ret)
5497 		bpf_prog_put(new_prog);
5498 out_put_link:
5499 	bpf_link_put_direct(link);
5500 	return ret;
5501 }
5502 
5503 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5504 
link_detach(union bpf_attr * attr)5505 static int link_detach(union bpf_attr *attr)
5506 {
5507 	struct bpf_link *link;
5508 	int ret;
5509 
5510 	if (CHECK_ATTR(BPF_LINK_DETACH))
5511 		return -EINVAL;
5512 
5513 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5514 	if (IS_ERR(link))
5515 		return PTR_ERR(link);
5516 
5517 	if (link->ops->detach)
5518 		ret = link->ops->detach(link);
5519 	else
5520 		ret = -EOPNOTSUPP;
5521 
5522 	bpf_link_put_direct(link);
5523 	return ret;
5524 }
5525 
bpf_link_inc_not_zero(struct bpf_link * link)5526 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5527 {
5528 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5529 }
5530 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5531 
bpf_link_by_id(u32 id)5532 struct bpf_link *bpf_link_by_id(u32 id)
5533 {
5534 	struct bpf_link *link;
5535 
5536 	if (!id)
5537 		return ERR_PTR(-ENOENT);
5538 
5539 	spin_lock_bh(&link_idr_lock);
5540 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5541 	link = idr_find(&link_idr, id);
5542 	if (link) {
5543 		if (link->id)
5544 			link = bpf_link_inc_not_zero(link);
5545 		else
5546 			link = ERR_PTR(-EAGAIN);
5547 	} else {
5548 		link = ERR_PTR(-ENOENT);
5549 	}
5550 	spin_unlock_bh(&link_idr_lock);
5551 	return link;
5552 }
5553 
bpf_link_get_curr_or_next(u32 * id)5554 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5555 {
5556 	struct bpf_link *link;
5557 
5558 	spin_lock_bh(&link_idr_lock);
5559 again:
5560 	link = idr_get_next(&link_idr, id);
5561 	if (link) {
5562 		link = bpf_link_inc_not_zero(link);
5563 		if (IS_ERR(link)) {
5564 			(*id)++;
5565 			goto again;
5566 		}
5567 	}
5568 	spin_unlock_bh(&link_idr_lock);
5569 
5570 	return link;
5571 }
5572 
5573 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5574 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5575 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5576 {
5577 	struct bpf_link *link;
5578 	u32 id = attr->link_id;
5579 	int fd;
5580 
5581 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5582 		return -EINVAL;
5583 
5584 	if (!capable(CAP_SYS_ADMIN))
5585 		return -EPERM;
5586 
5587 	link = bpf_link_by_id(id);
5588 	if (IS_ERR(link))
5589 		return PTR_ERR(link);
5590 
5591 	fd = bpf_link_new_fd(link);
5592 	if (fd < 0)
5593 		bpf_link_put_direct(link);
5594 
5595 	return fd;
5596 }
5597 
5598 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5599 
bpf_stats_release(struct inode * inode,struct file * file)5600 static int bpf_stats_release(struct inode *inode, struct file *file)
5601 {
5602 	mutex_lock(&bpf_stats_enabled_mutex);
5603 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5604 	mutex_unlock(&bpf_stats_enabled_mutex);
5605 	return 0;
5606 }
5607 
5608 static const struct file_operations bpf_stats_fops = {
5609 	.release = bpf_stats_release,
5610 };
5611 
bpf_enable_runtime_stats(void)5612 static int bpf_enable_runtime_stats(void)
5613 {
5614 	int fd;
5615 
5616 	mutex_lock(&bpf_stats_enabled_mutex);
5617 
5618 	/* Set a very high limit to avoid overflow */
5619 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5620 		mutex_unlock(&bpf_stats_enabled_mutex);
5621 		return -EBUSY;
5622 	}
5623 
5624 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5625 	if (fd >= 0)
5626 		static_key_slow_inc(&bpf_stats_enabled_key.key);
5627 
5628 	mutex_unlock(&bpf_stats_enabled_mutex);
5629 	return fd;
5630 }
5631 
5632 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5633 
bpf_enable_stats(union bpf_attr * attr)5634 static int bpf_enable_stats(union bpf_attr *attr)
5635 {
5636 
5637 	if (CHECK_ATTR(BPF_ENABLE_STATS))
5638 		return -EINVAL;
5639 
5640 	if (!capable(CAP_SYS_ADMIN))
5641 		return -EPERM;
5642 
5643 	switch (attr->enable_stats.type) {
5644 	case BPF_STATS_RUN_TIME:
5645 		return bpf_enable_runtime_stats();
5646 	default:
5647 		break;
5648 	}
5649 	return -EINVAL;
5650 }
5651 
5652 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
5653 
bpf_iter_create(union bpf_attr * attr)5654 static int bpf_iter_create(union bpf_attr *attr)
5655 {
5656 	struct bpf_link *link;
5657 	int err;
5658 
5659 	if (CHECK_ATTR(BPF_ITER_CREATE))
5660 		return -EINVAL;
5661 
5662 	if (attr->iter_create.flags)
5663 		return -EINVAL;
5664 
5665 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
5666 	if (IS_ERR(link))
5667 		return PTR_ERR(link);
5668 
5669 	err = bpf_iter_new_fd(link);
5670 	bpf_link_put_direct(link);
5671 
5672 	return err;
5673 }
5674 
5675 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
5676 
bpf_prog_bind_map(union bpf_attr * attr)5677 static int bpf_prog_bind_map(union bpf_attr *attr)
5678 {
5679 	struct bpf_prog *prog;
5680 	struct bpf_map *map;
5681 	struct bpf_map **used_maps_old, **used_maps_new;
5682 	int i, ret = 0;
5683 
5684 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
5685 		return -EINVAL;
5686 
5687 	if (attr->prog_bind_map.flags)
5688 		return -EINVAL;
5689 
5690 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
5691 	if (IS_ERR(prog))
5692 		return PTR_ERR(prog);
5693 
5694 	map = bpf_map_get(attr->prog_bind_map.map_fd);
5695 	if (IS_ERR(map)) {
5696 		ret = PTR_ERR(map);
5697 		goto out_prog_put;
5698 	}
5699 
5700 	mutex_lock(&prog->aux->used_maps_mutex);
5701 
5702 	used_maps_old = prog->aux->used_maps;
5703 
5704 	for (i = 0; i < prog->aux->used_map_cnt; i++)
5705 		if (used_maps_old[i] == map) {
5706 			bpf_map_put(map);
5707 			goto out_unlock;
5708 		}
5709 
5710 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
5711 				      sizeof(used_maps_new[0]),
5712 				      GFP_KERNEL);
5713 	if (!used_maps_new) {
5714 		ret = -ENOMEM;
5715 		goto out_unlock;
5716 	}
5717 
5718 	/* The bpf program will not access the bpf map, but for the sake of
5719 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
5720 	 */
5721 	if (prog->sleepable)
5722 		atomic64_inc(&map->sleepable_refcnt);
5723 	memcpy(used_maps_new, used_maps_old,
5724 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
5725 	used_maps_new[prog->aux->used_map_cnt] = map;
5726 
5727 	prog->aux->used_map_cnt++;
5728 	prog->aux->used_maps = used_maps_new;
5729 
5730 	kfree(used_maps_old);
5731 
5732 out_unlock:
5733 	mutex_unlock(&prog->aux->used_maps_mutex);
5734 
5735 	if (ret)
5736 		bpf_map_put(map);
5737 out_prog_put:
5738 	bpf_prog_put(prog);
5739 	return ret;
5740 }
5741 
5742 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
5743 
token_create(union bpf_attr * attr)5744 static int token_create(union bpf_attr *attr)
5745 {
5746 	if (CHECK_ATTR(BPF_TOKEN_CREATE))
5747 		return -EINVAL;
5748 
5749 	/* no flags are supported yet */
5750 	if (attr->token_create.flags)
5751 		return -EINVAL;
5752 
5753 	return bpf_token_create(attr);
5754 }
5755 
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)5756 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
5757 {
5758 	union bpf_attr attr;
5759 	int err;
5760 
5761 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
5762 	if (err)
5763 		return err;
5764 	size = min_t(u32, size, sizeof(attr));
5765 
5766 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
5767 	memset(&attr, 0, sizeof(attr));
5768 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
5769 		return -EFAULT;
5770 
5771 	err = security_bpf(cmd, &attr, size);
5772 	if (err < 0)
5773 		return err;
5774 
5775 	switch (cmd) {
5776 	case BPF_MAP_CREATE:
5777 		err = map_create(&attr);
5778 		break;
5779 	case BPF_MAP_LOOKUP_ELEM:
5780 		err = map_lookup_elem(&attr);
5781 		break;
5782 	case BPF_MAP_UPDATE_ELEM:
5783 		err = map_update_elem(&attr, uattr);
5784 		break;
5785 	case BPF_MAP_DELETE_ELEM:
5786 		err = map_delete_elem(&attr, uattr);
5787 		break;
5788 	case BPF_MAP_GET_NEXT_KEY:
5789 		err = map_get_next_key(&attr);
5790 		break;
5791 	case BPF_MAP_FREEZE:
5792 		err = map_freeze(&attr);
5793 		break;
5794 	case BPF_PROG_LOAD:
5795 		err = bpf_prog_load(&attr, uattr, size);
5796 		break;
5797 	case BPF_OBJ_PIN:
5798 		err = bpf_obj_pin(&attr);
5799 		break;
5800 	case BPF_OBJ_GET:
5801 		err = bpf_obj_get(&attr);
5802 		break;
5803 	case BPF_PROG_ATTACH:
5804 		err = bpf_prog_attach(&attr);
5805 		break;
5806 	case BPF_PROG_DETACH:
5807 		err = bpf_prog_detach(&attr);
5808 		break;
5809 	case BPF_PROG_QUERY:
5810 		err = bpf_prog_query(&attr, uattr.user);
5811 		break;
5812 	case BPF_PROG_TEST_RUN:
5813 		err = bpf_prog_test_run(&attr, uattr.user);
5814 		break;
5815 	case BPF_PROG_GET_NEXT_ID:
5816 		err = bpf_obj_get_next_id(&attr, uattr.user,
5817 					  &prog_idr, &prog_idr_lock);
5818 		break;
5819 	case BPF_MAP_GET_NEXT_ID:
5820 		err = bpf_obj_get_next_id(&attr, uattr.user,
5821 					  &map_idr, &map_idr_lock);
5822 		break;
5823 	case BPF_BTF_GET_NEXT_ID:
5824 		err = bpf_obj_get_next_id(&attr, uattr.user,
5825 					  &btf_idr, &btf_idr_lock);
5826 		break;
5827 	case BPF_PROG_GET_FD_BY_ID:
5828 		err = bpf_prog_get_fd_by_id(&attr);
5829 		break;
5830 	case BPF_MAP_GET_FD_BY_ID:
5831 		err = bpf_map_get_fd_by_id(&attr);
5832 		break;
5833 	case BPF_OBJ_GET_INFO_BY_FD:
5834 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
5835 		break;
5836 	case BPF_RAW_TRACEPOINT_OPEN:
5837 		err = bpf_raw_tracepoint_open(&attr);
5838 		break;
5839 	case BPF_BTF_LOAD:
5840 		err = bpf_btf_load(&attr, uattr, size);
5841 		break;
5842 	case BPF_BTF_GET_FD_BY_ID:
5843 		err = bpf_btf_get_fd_by_id(&attr);
5844 		break;
5845 	case BPF_TASK_FD_QUERY:
5846 		err = bpf_task_fd_query(&attr, uattr.user);
5847 		break;
5848 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
5849 		err = map_lookup_and_delete_elem(&attr);
5850 		break;
5851 	case BPF_MAP_LOOKUP_BATCH:
5852 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
5853 		break;
5854 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
5855 		err = bpf_map_do_batch(&attr, uattr.user,
5856 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
5857 		break;
5858 	case BPF_MAP_UPDATE_BATCH:
5859 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
5860 		break;
5861 	case BPF_MAP_DELETE_BATCH:
5862 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
5863 		break;
5864 	case BPF_LINK_CREATE:
5865 		err = link_create(&attr, uattr);
5866 		break;
5867 	case BPF_LINK_UPDATE:
5868 		err = link_update(&attr);
5869 		break;
5870 	case BPF_LINK_GET_FD_BY_ID:
5871 		err = bpf_link_get_fd_by_id(&attr);
5872 		break;
5873 	case BPF_LINK_GET_NEXT_ID:
5874 		err = bpf_obj_get_next_id(&attr, uattr.user,
5875 					  &link_idr, &link_idr_lock);
5876 		break;
5877 	case BPF_ENABLE_STATS:
5878 		err = bpf_enable_stats(&attr);
5879 		break;
5880 	case BPF_ITER_CREATE:
5881 		err = bpf_iter_create(&attr);
5882 		break;
5883 	case BPF_LINK_DETACH:
5884 		err = link_detach(&attr);
5885 		break;
5886 	case BPF_PROG_BIND_MAP:
5887 		err = bpf_prog_bind_map(&attr);
5888 		break;
5889 	case BPF_TOKEN_CREATE:
5890 		err = token_create(&attr);
5891 		break;
5892 	default:
5893 		err = -EINVAL;
5894 		break;
5895 	}
5896 
5897 	return err;
5898 }
5899 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5900 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5901 {
5902 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5903 }
5904 
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)5905 static bool syscall_prog_is_valid_access(int off, int size,
5906 					 enum bpf_access_type type,
5907 					 const struct bpf_prog *prog,
5908 					 struct bpf_insn_access_aux *info)
5909 {
5910 	if (off < 0 || off >= U16_MAX)
5911 		return false;
5912 	if (off % size != 0)
5913 		return false;
5914 	return true;
5915 }
5916 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5917 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5918 {
5919 	switch (cmd) {
5920 	case BPF_MAP_CREATE:
5921 	case BPF_MAP_DELETE_ELEM:
5922 	case BPF_MAP_UPDATE_ELEM:
5923 	case BPF_MAP_FREEZE:
5924 	case BPF_MAP_GET_FD_BY_ID:
5925 	case BPF_PROG_LOAD:
5926 	case BPF_BTF_LOAD:
5927 	case BPF_LINK_CREATE:
5928 	case BPF_RAW_TRACEPOINT_OPEN:
5929 		break;
5930 	default:
5931 		return -EINVAL;
5932 	}
5933 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5934 }
5935 
5936 
5937 /* To shut up -Wmissing-prototypes.
5938  * This function is used by the kernel light skeleton
5939  * to load bpf programs when modules are loaded or during kernel boot.
5940  * See tools/lib/bpf/skel_internal.h
5941  */
5942 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
5943 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5944 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5945 {
5946 	struct bpf_prog * __maybe_unused prog;
5947 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5948 
5949 	switch (cmd) {
5950 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5951 	case BPF_PROG_TEST_RUN:
5952 		if (attr->test.data_in || attr->test.data_out ||
5953 		    attr->test.ctx_out || attr->test.duration ||
5954 		    attr->test.repeat || attr->test.flags)
5955 			return -EINVAL;
5956 
5957 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5958 		if (IS_ERR(prog))
5959 			return PTR_ERR(prog);
5960 
5961 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
5962 		    attr->test.ctx_size_in > U16_MAX) {
5963 			bpf_prog_put(prog);
5964 			return -EINVAL;
5965 		}
5966 
5967 		run_ctx.bpf_cookie = 0;
5968 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
5969 			/* recursion detected */
5970 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
5971 			bpf_prog_put(prog);
5972 			return -EBUSY;
5973 		}
5974 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
5975 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
5976 						&run_ctx);
5977 		bpf_prog_put(prog);
5978 		return 0;
5979 #endif
5980 	default:
5981 		return ____bpf_sys_bpf(cmd, attr, size);
5982 	}
5983 }
5984 EXPORT_SYMBOL(kern_sys_bpf);
5985 
5986 static const struct bpf_func_proto bpf_sys_bpf_proto = {
5987 	.func		= bpf_sys_bpf,
5988 	.gpl_only	= false,
5989 	.ret_type	= RET_INTEGER,
5990 	.arg1_type	= ARG_ANYTHING,
5991 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
5992 	.arg3_type	= ARG_CONST_SIZE,
5993 };
5994 
5995 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5996 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5997 {
5998 	return bpf_base_func_proto(func_id, prog);
5999 }
6000 
BPF_CALL_1(bpf_sys_close,u32,fd)6001 BPF_CALL_1(bpf_sys_close, u32, fd)
6002 {
6003 	/* When bpf program calls this helper there should not be
6004 	 * an fdget() without matching completed fdput().
6005 	 * This helper is allowed in the following callchain only:
6006 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6007 	 */
6008 	return close_fd(fd);
6009 }
6010 
6011 static const struct bpf_func_proto bpf_sys_close_proto = {
6012 	.func		= bpf_sys_close,
6013 	.gpl_only	= false,
6014 	.ret_type	= RET_INTEGER,
6015 	.arg1_type	= ARG_ANYTHING,
6016 };
6017 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6018 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6019 {
6020 	*res = 0;
6021 	if (flags)
6022 		return -EINVAL;
6023 
6024 	if (name_sz <= 1 || name[name_sz - 1])
6025 		return -EINVAL;
6026 
6027 	if (!bpf_dump_raw_ok(current_cred()))
6028 		return -EPERM;
6029 
6030 	*res = kallsyms_lookup_name(name);
6031 	return *res ? 0 : -ENOENT;
6032 }
6033 
6034 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6035 	.func		= bpf_kallsyms_lookup_name,
6036 	.gpl_only	= false,
6037 	.ret_type	= RET_INTEGER,
6038 	.arg1_type	= ARG_PTR_TO_MEM,
6039 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
6040 	.arg3_type	= ARG_ANYTHING,
6041 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6042 	.arg4_size	= sizeof(u64),
6043 };
6044 
6045 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6046 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6047 {
6048 	switch (func_id) {
6049 	case BPF_FUNC_sys_bpf:
6050 		return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6051 		       ? NULL : &bpf_sys_bpf_proto;
6052 	case BPF_FUNC_btf_find_by_name_kind:
6053 		return &bpf_btf_find_by_name_kind_proto;
6054 	case BPF_FUNC_sys_close:
6055 		return &bpf_sys_close_proto;
6056 	case BPF_FUNC_kallsyms_lookup_name:
6057 		return &bpf_kallsyms_lookup_name_proto;
6058 	default:
6059 		return tracing_prog_func_proto(func_id, prog);
6060 	}
6061 }
6062 
6063 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6064 	.get_func_proto  = syscall_prog_func_proto,
6065 	.is_valid_access = syscall_prog_is_valid_access,
6066 };
6067 
6068 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6069 	.test_run = bpf_prog_test_run_syscall,
6070 };
6071 
6072 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6073 static int bpf_stats_handler(const struct ctl_table *table, int write,
6074 			     void *buffer, size_t *lenp, loff_t *ppos)
6075 {
6076 	struct static_key *key = (struct static_key *)table->data;
6077 	static int saved_val;
6078 	int val, ret;
6079 	struct ctl_table tmp = {
6080 		.data   = &val,
6081 		.maxlen = sizeof(val),
6082 		.mode   = table->mode,
6083 		.extra1 = SYSCTL_ZERO,
6084 		.extra2 = SYSCTL_ONE,
6085 	};
6086 
6087 	if (write && !capable(CAP_SYS_ADMIN))
6088 		return -EPERM;
6089 
6090 	mutex_lock(&bpf_stats_enabled_mutex);
6091 	val = saved_val;
6092 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6093 	if (write && !ret && val != saved_val) {
6094 		if (val)
6095 			static_key_slow_inc(key);
6096 		else
6097 			static_key_slow_dec(key);
6098 		saved_val = val;
6099 	}
6100 	mutex_unlock(&bpf_stats_enabled_mutex);
6101 	return ret;
6102 }
6103 
unpriv_ebpf_notify(int new_state)6104 void __weak unpriv_ebpf_notify(int new_state)
6105 {
6106 }
6107 
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6108 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6109 			      void *buffer, size_t *lenp, loff_t *ppos)
6110 {
6111 	int ret, unpriv_enable = *(int *)table->data;
6112 	bool locked_state = unpriv_enable == 1;
6113 	struct ctl_table tmp = *table;
6114 
6115 	if (write && !capable(CAP_SYS_ADMIN))
6116 		return -EPERM;
6117 
6118 	tmp.data = &unpriv_enable;
6119 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6120 	if (write && !ret) {
6121 		if (locked_state && unpriv_enable != 1)
6122 			return -EPERM;
6123 		*(int *)table->data = unpriv_enable;
6124 	}
6125 
6126 	if (write)
6127 		unpriv_ebpf_notify(unpriv_enable);
6128 
6129 	return ret;
6130 }
6131 
6132 static const struct ctl_table bpf_syscall_table[] = {
6133 	{
6134 		.procname	= "unprivileged_bpf_disabled",
6135 		.data		= &sysctl_unprivileged_bpf_disabled,
6136 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
6137 		.mode		= 0644,
6138 		.proc_handler	= bpf_unpriv_handler,
6139 		.extra1		= SYSCTL_ZERO,
6140 		.extra2		= SYSCTL_TWO,
6141 	},
6142 	{
6143 		.procname	= "bpf_stats_enabled",
6144 		.data		= &bpf_stats_enabled_key.key,
6145 		.mode		= 0644,
6146 		.proc_handler	= bpf_stats_handler,
6147 	},
6148 };
6149 
bpf_syscall_sysctl_init(void)6150 static int __init bpf_syscall_sysctl_init(void)
6151 {
6152 	register_sysctl_init("kernel", bpf_syscall_table);
6153 	return 0;
6154 }
6155 late_initcall(bpf_syscall_sysctl_init);
6156 #endif /* CONFIG_SYSCTL */
6157