xref: /linux/kernel/bpf/syscall.c (revision df02351331671abb26788bc13f6d276e26ae068f)
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 
can_alloc_pages(void)572 static bool can_alloc_pages(void)
573 {
574 	return preempt_count() == 0 && !irqs_disabled() &&
575 		!IS_ENABLED(CONFIG_PREEMPT_RT);
576 }
577 
__bpf_alloc_page(int nid)578 static struct page *__bpf_alloc_page(int nid)
579 {
580 	if (!can_alloc_pages())
581 		return try_alloc_pages(nid, 0);
582 
583 	return alloc_pages_node(nid,
584 				GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
585 				| __GFP_NOWARN,
586 				0);
587 }
588 
bpf_map_alloc_pages(const struct bpf_map * map,int nid,unsigned long nr_pages,struct page ** pages)589 int bpf_map_alloc_pages(const struct bpf_map *map, int nid,
590 			unsigned long nr_pages, struct page **pages)
591 {
592 	unsigned long i, j;
593 	struct page *pg;
594 	int ret = 0;
595 #ifdef CONFIG_MEMCG
596 	struct mem_cgroup *memcg, *old_memcg;
597 
598 	memcg = bpf_map_get_memcg(map);
599 	old_memcg = set_active_memcg(memcg);
600 #endif
601 	for (i = 0; i < nr_pages; i++) {
602 		pg = __bpf_alloc_page(nid);
603 
604 		if (pg) {
605 			pages[i] = pg;
606 			continue;
607 		}
608 		for (j = 0; j < i; j++)
609 			free_pages_nolock(pages[j], 0);
610 		ret = -ENOMEM;
611 		break;
612 	}
613 
614 #ifdef CONFIG_MEMCG
615 	set_active_memcg(old_memcg);
616 	mem_cgroup_put(memcg);
617 #endif
618 	return ret;
619 }
620 
621 
btf_field_cmp(const void * a,const void * b)622 static int btf_field_cmp(const void *a, const void *b)
623 {
624 	const struct btf_field *f1 = a, *f2 = b;
625 
626 	if (f1->offset < f2->offset)
627 		return -1;
628 	else if (f1->offset > f2->offset)
629 		return 1;
630 	return 0;
631 }
632 
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)633 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
634 				  u32 field_mask)
635 {
636 	struct btf_field *field;
637 
638 	if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
639 		return NULL;
640 	field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
641 	if (!field || !(field->type & field_mask))
642 		return NULL;
643 	return field;
644 }
645 
btf_record_free(struct btf_record * rec)646 void btf_record_free(struct btf_record *rec)
647 {
648 	int i;
649 
650 	if (IS_ERR_OR_NULL(rec))
651 		return;
652 	for (i = 0; i < rec->cnt; i++) {
653 		switch (rec->fields[i].type) {
654 		case BPF_KPTR_UNREF:
655 		case BPF_KPTR_REF:
656 		case BPF_KPTR_PERCPU:
657 		case BPF_UPTR:
658 			if (rec->fields[i].kptr.module)
659 				module_put(rec->fields[i].kptr.module);
660 			if (btf_is_kernel(rec->fields[i].kptr.btf))
661 				btf_put(rec->fields[i].kptr.btf);
662 			break;
663 		case BPF_LIST_HEAD:
664 		case BPF_LIST_NODE:
665 		case BPF_RB_ROOT:
666 		case BPF_RB_NODE:
667 		case BPF_SPIN_LOCK:
668 		case BPF_RES_SPIN_LOCK:
669 		case BPF_TIMER:
670 		case BPF_REFCOUNT:
671 		case BPF_WORKQUEUE:
672 			/* Nothing to release */
673 			break;
674 		default:
675 			WARN_ON_ONCE(1);
676 			continue;
677 		}
678 	}
679 	kfree(rec);
680 }
681 
bpf_map_free_record(struct bpf_map * map)682 void bpf_map_free_record(struct bpf_map *map)
683 {
684 	btf_record_free(map->record);
685 	map->record = NULL;
686 }
687 
btf_record_dup(const struct btf_record * rec)688 struct btf_record *btf_record_dup(const struct btf_record *rec)
689 {
690 	const struct btf_field *fields;
691 	struct btf_record *new_rec;
692 	int ret, size, i;
693 
694 	if (IS_ERR_OR_NULL(rec))
695 		return NULL;
696 	size = offsetof(struct btf_record, fields[rec->cnt]);
697 	new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
698 	if (!new_rec)
699 		return ERR_PTR(-ENOMEM);
700 	/* Do a deep copy of the btf_record */
701 	fields = rec->fields;
702 	new_rec->cnt = 0;
703 	for (i = 0; i < rec->cnt; i++) {
704 		switch (fields[i].type) {
705 		case BPF_KPTR_UNREF:
706 		case BPF_KPTR_REF:
707 		case BPF_KPTR_PERCPU:
708 		case BPF_UPTR:
709 			if (btf_is_kernel(fields[i].kptr.btf))
710 				btf_get(fields[i].kptr.btf);
711 			if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
712 				ret = -ENXIO;
713 				goto free;
714 			}
715 			break;
716 		case BPF_LIST_HEAD:
717 		case BPF_LIST_NODE:
718 		case BPF_RB_ROOT:
719 		case BPF_RB_NODE:
720 		case BPF_SPIN_LOCK:
721 		case BPF_RES_SPIN_LOCK:
722 		case BPF_TIMER:
723 		case BPF_REFCOUNT:
724 		case BPF_WORKQUEUE:
725 			/* Nothing to acquire */
726 			break;
727 		default:
728 			ret = -EFAULT;
729 			WARN_ON_ONCE(1);
730 			goto free;
731 		}
732 		new_rec->cnt++;
733 	}
734 	return new_rec;
735 free:
736 	btf_record_free(new_rec);
737 	return ERR_PTR(ret);
738 }
739 
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)740 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
741 {
742 	bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
743 	int size;
744 
745 	if (!a_has_fields && !b_has_fields)
746 		return true;
747 	if (a_has_fields != b_has_fields)
748 		return false;
749 	if (rec_a->cnt != rec_b->cnt)
750 		return false;
751 	size = offsetof(struct btf_record, fields[rec_a->cnt]);
752 	/* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
753 	 * members are zeroed out. So memcmp is safe to do without worrying
754 	 * about padding/unused fields.
755 	 *
756 	 * While spin_lock, timer, and kptr have no relation to map BTF,
757 	 * list_head metadata is specific to map BTF, the btf and value_rec
758 	 * members in particular. btf is the map BTF, while value_rec points to
759 	 * btf_record in that map BTF.
760 	 *
761 	 * So while by default, we don't rely on the map BTF (which the records
762 	 * were parsed from) matching for both records, which is not backwards
763 	 * compatible, in case list_head is part of it, we implicitly rely on
764 	 * that by way of depending on memcmp succeeding for it.
765 	 */
766 	return !memcmp(rec_a, rec_b, size);
767 }
768 
bpf_obj_free_timer(const struct btf_record * rec,void * obj)769 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
770 {
771 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
772 		return;
773 	bpf_timer_cancel_and_free(obj + rec->timer_off);
774 }
775 
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)776 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
777 {
778 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
779 		return;
780 	bpf_wq_cancel_and_free(obj + rec->wq_off);
781 }
782 
bpf_obj_free_fields(const struct btf_record * rec,void * obj)783 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
784 {
785 	const struct btf_field *fields;
786 	int i;
787 
788 	if (IS_ERR_OR_NULL(rec))
789 		return;
790 	fields = rec->fields;
791 	for (i = 0; i < rec->cnt; i++) {
792 		struct btf_struct_meta *pointee_struct_meta;
793 		const struct btf_field *field = &fields[i];
794 		void *field_ptr = obj + field->offset;
795 		void *xchgd_field;
796 
797 		switch (fields[i].type) {
798 		case BPF_SPIN_LOCK:
799 		case BPF_RES_SPIN_LOCK:
800 			break;
801 		case BPF_TIMER:
802 			bpf_timer_cancel_and_free(field_ptr);
803 			break;
804 		case BPF_WORKQUEUE:
805 			bpf_wq_cancel_and_free(field_ptr);
806 			break;
807 		case BPF_KPTR_UNREF:
808 			WRITE_ONCE(*(u64 *)field_ptr, 0);
809 			break;
810 		case BPF_KPTR_REF:
811 		case BPF_KPTR_PERCPU:
812 			xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
813 			if (!xchgd_field)
814 				break;
815 
816 			if (!btf_is_kernel(field->kptr.btf)) {
817 				pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
818 									   field->kptr.btf_id);
819 				__bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
820 								 pointee_struct_meta->record : NULL,
821 								 fields[i].type == BPF_KPTR_PERCPU);
822 			} else {
823 				field->kptr.dtor(xchgd_field);
824 			}
825 			break;
826 		case BPF_UPTR:
827 			/* The caller ensured that no one is using the uptr */
828 			unpin_uptr_kaddr(*(void **)field_ptr);
829 			break;
830 		case BPF_LIST_HEAD:
831 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
832 				continue;
833 			bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
834 			break;
835 		case BPF_RB_ROOT:
836 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
837 				continue;
838 			bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
839 			break;
840 		case BPF_LIST_NODE:
841 		case BPF_RB_NODE:
842 		case BPF_REFCOUNT:
843 			break;
844 		default:
845 			WARN_ON_ONCE(1);
846 			continue;
847 		}
848 	}
849 }
850 
bpf_map_free(struct bpf_map * map)851 static void bpf_map_free(struct bpf_map *map)
852 {
853 	struct btf_record *rec = map->record;
854 	struct btf *btf = map->btf;
855 
856 	/* implementation dependent freeing. Disabling migration to simplify
857 	 * the free of values or special fields allocated from bpf memory
858 	 * allocator.
859 	 */
860 	migrate_disable();
861 	map->ops->map_free(map);
862 	migrate_enable();
863 
864 	/* Delay freeing of btf_record for maps, as map_free
865 	 * callback usually needs access to them. It is better to do it here
866 	 * than require each callback to do the free itself manually.
867 	 *
868 	 * Note that the btf_record stashed in map->inner_map_meta->record was
869 	 * already freed using the map_free callback for map in map case which
870 	 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
871 	 * template bpf_map struct used during verification.
872 	 */
873 	btf_record_free(rec);
874 	/* Delay freeing of btf for maps, as map_free callback may need
875 	 * struct_meta info which will be freed with btf_put().
876 	 */
877 	btf_put(btf);
878 }
879 
880 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)881 static void bpf_map_free_deferred(struct work_struct *work)
882 {
883 	struct bpf_map *map = container_of(work, struct bpf_map, work);
884 
885 	security_bpf_map_free(map);
886 	bpf_map_release_memcg(map);
887 	bpf_map_free(map);
888 }
889 
bpf_map_put_uref(struct bpf_map * map)890 static void bpf_map_put_uref(struct bpf_map *map)
891 {
892 	if (atomic64_dec_and_test(&map->usercnt)) {
893 		if (map->ops->map_release_uref)
894 			map->ops->map_release_uref(map);
895 	}
896 }
897 
bpf_map_free_in_work(struct bpf_map * map)898 static void bpf_map_free_in_work(struct bpf_map *map)
899 {
900 	INIT_WORK(&map->work, bpf_map_free_deferred);
901 	/* Avoid spawning kworkers, since they all might contend
902 	 * for the same mutex like slab_mutex.
903 	 */
904 	queue_work(system_unbound_wq, &map->work);
905 }
906 
bpf_map_free_rcu_gp(struct rcu_head * rcu)907 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
908 {
909 	bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
910 }
911 
bpf_map_free_mult_rcu_gp(struct rcu_head * rcu)912 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
913 {
914 	if (rcu_trace_implies_rcu_gp())
915 		bpf_map_free_rcu_gp(rcu);
916 	else
917 		call_rcu(rcu, bpf_map_free_rcu_gp);
918 }
919 
920 /* decrement map refcnt and schedule it for freeing via workqueue
921  * (underlying map implementation ops->map_free() might sleep)
922  */
bpf_map_put(struct bpf_map * map)923 void bpf_map_put(struct bpf_map *map)
924 {
925 	if (atomic64_dec_and_test(&map->refcnt)) {
926 		/* bpf_map_free_id() must be called first */
927 		bpf_map_free_id(map);
928 
929 		WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
930 		if (READ_ONCE(map->free_after_mult_rcu_gp))
931 			call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
932 		else if (READ_ONCE(map->free_after_rcu_gp))
933 			call_rcu(&map->rcu, bpf_map_free_rcu_gp);
934 		else
935 			bpf_map_free_in_work(map);
936 	}
937 }
938 EXPORT_SYMBOL_GPL(bpf_map_put);
939 
bpf_map_put_with_uref(struct bpf_map * map)940 void bpf_map_put_with_uref(struct bpf_map *map)
941 {
942 	bpf_map_put_uref(map);
943 	bpf_map_put(map);
944 }
945 
bpf_map_release(struct inode * inode,struct file * filp)946 static int bpf_map_release(struct inode *inode, struct file *filp)
947 {
948 	struct bpf_map *map = filp->private_data;
949 
950 	if (map->ops->map_release)
951 		map->ops->map_release(map, filp);
952 
953 	bpf_map_put_with_uref(map);
954 	return 0;
955 }
956 
map_get_sys_perms(struct bpf_map * map,struct fd f)957 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
958 {
959 	fmode_t mode = fd_file(f)->f_mode;
960 
961 	/* Our file permissions may have been overridden by global
962 	 * map permissions facing syscall side.
963 	 */
964 	if (READ_ONCE(map->frozen))
965 		mode &= ~FMODE_CAN_WRITE;
966 	return mode;
967 }
968 
969 #ifdef CONFIG_PROC_FS
970 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)971 static u64 bpf_map_memory_usage(const struct bpf_map *map)
972 {
973 	return map->ops->map_mem_usage(map);
974 }
975 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)976 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
977 {
978 	struct bpf_map *map = filp->private_data;
979 	u32 type = 0, jited = 0;
980 
981 	if (map_type_contains_progs(map)) {
982 		spin_lock(&map->owner.lock);
983 		type  = map->owner.type;
984 		jited = map->owner.jited;
985 		spin_unlock(&map->owner.lock);
986 	}
987 
988 	seq_printf(m,
989 		   "map_type:\t%u\n"
990 		   "key_size:\t%u\n"
991 		   "value_size:\t%u\n"
992 		   "max_entries:\t%u\n"
993 		   "map_flags:\t%#x\n"
994 		   "map_extra:\t%#llx\n"
995 		   "memlock:\t%llu\n"
996 		   "map_id:\t%u\n"
997 		   "frozen:\t%u\n",
998 		   map->map_type,
999 		   map->key_size,
1000 		   map->value_size,
1001 		   map->max_entries,
1002 		   map->map_flags,
1003 		   (unsigned long long)map->map_extra,
1004 		   bpf_map_memory_usage(map),
1005 		   map->id,
1006 		   READ_ONCE(map->frozen));
1007 	if (type) {
1008 		seq_printf(m, "owner_prog_type:\t%u\n", type);
1009 		seq_printf(m, "owner_jited:\t%u\n", jited);
1010 	}
1011 }
1012 #endif
1013 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)1014 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
1015 			      loff_t *ppos)
1016 {
1017 	/* We need this handler such that alloc_file() enables
1018 	 * f_mode with FMODE_CAN_READ.
1019 	 */
1020 	return -EINVAL;
1021 }
1022 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1023 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1024 			       size_t siz, loff_t *ppos)
1025 {
1026 	/* We need this handler such that alloc_file() enables
1027 	 * f_mode with FMODE_CAN_WRITE.
1028 	 */
1029 	return -EINVAL;
1030 }
1031 
1032 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1033 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1034 {
1035 	struct bpf_map *map = vma->vm_file->private_data;
1036 
1037 	if (vma->vm_flags & VM_MAYWRITE)
1038 		bpf_map_write_active_inc(map);
1039 }
1040 
1041 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1042 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1043 {
1044 	struct bpf_map *map = vma->vm_file->private_data;
1045 
1046 	if (vma->vm_flags & VM_MAYWRITE)
1047 		bpf_map_write_active_dec(map);
1048 }
1049 
1050 static const struct vm_operations_struct bpf_map_default_vmops = {
1051 	.open		= bpf_map_mmap_open,
1052 	.close		= bpf_map_mmap_close,
1053 };
1054 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1055 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1056 {
1057 	struct bpf_map *map = filp->private_data;
1058 	int err = 0;
1059 
1060 	if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1061 		return -ENOTSUPP;
1062 
1063 	if (!(vma->vm_flags & VM_SHARED))
1064 		return -EINVAL;
1065 
1066 	mutex_lock(&map->freeze_mutex);
1067 
1068 	if (vma->vm_flags & VM_WRITE) {
1069 		if (map->frozen) {
1070 			err = -EPERM;
1071 			goto out;
1072 		}
1073 		/* map is meant to be read-only, so do not allow mapping as
1074 		 * writable, because it's possible to leak a writable page
1075 		 * reference and allows user-space to still modify it after
1076 		 * freezing, while verifier will assume contents do not change
1077 		 */
1078 		if (map->map_flags & BPF_F_RDONLY_PROG) {
1079 			err = -EACCES;
1080 			goto out;
1081 		}
1082 		bpf_map_write_active_inc(map);
1083 	}
1084 out:
1085 	mutex_unlock(&map->freeze_mutex);
1086 	if (err)
1087 		return err;
1088 
1089 	/* set default open/close callbacks */
1090 	vma->vm_ops = &bpf_map_default_vmops;
1091 	vma->vm_private_data = map;
1092 	vm_flags_clear(vma, VM_MAYEXEC);
1093 	/* If mapping is read-only, then disallow potentially re-mapping with
1094 	 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1095 	 * means that as far as BPF map's memory-mapped VMAs are concerned,
1096 	 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1097 	 * both should be set, so we can forget about VM_MAYWRITE and always
1098 	 * check just VM_WRITE
1099 	 */
1100 	if (!(vma->vm_flags & VM_WRITE))
1101 		vm_flags_clear(vma, VM_MAYWRITE);
1102 
1103 	err = map->ops->map_mmap(map, vma);
1104 	if (err) {
1105 		if (vma->vm_flags & VM_WRITE)
1106 			bpf_map_write_active_dec(map);
1107 	}
1108 
1109 	return err;
1110 }
1111 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1112 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1113 {
1114 	struct bpf_map *map = filp->private_data;
1115 
1116 	if (map->ops->map_poll)
1117 		return map->ops->map_poll(map, filp, pts);
1118 
1119 	return EPOLLERR;
1120 }
1121 
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1122 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1123 					   unsigned long len, unsigned long pgoff,
1124 					   unsigned long flags)
1125 {
1126 	struct bpf_map *map = filp->private_data;
1127 
1128 	if (map->ops->map_get_unmapped_area)
1129 		return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1130 #ifdef CONFIG_MMU
1131 	return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
1132 #else
1133 	return addr;
1134 #endif
1135 }
1136 
1137 const struct file_operations bpf_map_fops = {
1138 #ifdef CONFIG_PROC_FS
1139 	.show_fdinfo	= bpf_map_show_fdinfo,
1140 #endif
1141 	.release	= bpf_map_release,
1142 	.read		= bpf_dummy_read,
1143 	.write		= bpf_dummy_write,
1144 	.mmap		= bpf_map_mmap,
1145 	.poll		= bpf_map_poll,
1146 	.get_unmapped_area = bpf_get_unmapped_area,
1147 };
1148 
bpf_map_new_fd(struct bpf_map * map,int flags)1149 int bpf_map_new_fd(struct bpf_map *map, int flags)
1150 {
1151 	int ret;
1152 
1153 	ret = security_bpf_map(map, OPEN_FMODE(flags));
1154 	if (ret < 0)
1155 		return ret;
1156 
1157 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1158 				flags | O_CLOEXEC);
1159 }
1160 
bpf_get_file_flag(int flags)1161 int bpf_get_file_flag(int flags)
1162 {
1163 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1164 		return -EINVAL;
1165 	if (flags & BPF_F_RDONLY)
1166 		return O_RDONLY;
1167 	if (flags & BPF_F_WRONLY)
1168 		return O_WRONLY;
1169 	return O_RDWR;
1170 }
1171 
1172 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1173 #define CHECK_ATTR(CMD) \
1174 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1175 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
1176 		   sizeof(*attr) - \
1177 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1178 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
1179 
1180 /* dst and src must have at least "size" number of bytes.
1181  * Return strlen on success and < 0 on error.
1182  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1183 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1184 {
1185 	const char *end = src + size;
1186 	const char *orig_src = src;
1187 
1188 	memset(dst, 0, size);
1189 	/* Copy all isalnum(), '_' and '.' chars. */
1190 	while (src < end && *src) {
1191 		if (!isalnum(*src) &&
1192 		    *src != '_' && *src != '.')
1193 			return -EINVAL;
1194 		*dst++ = *src++;
1195 	}
1196 
1197 	/* No '\0' found in "size" number of bytes */
1198 	if (src == end)
1199 		return -EINVAL;
1200 
1201 	return src - orig_src;
1202 }
1203 
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)1204 int map_check_no_btf(const struct bpf_map *map,
1205 		     const struct btf *btf,
1206 		     const struct btf_type *key_type,
1207 		     const struct btf_type *value_type)
1208 {
1209 	return -ENOTSUPP;
1210 }
1211 
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1212 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1213 			 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1214 {
1215 	const struct btf_type *key_type, *value_type;
1216 	u32 key_size, value_size;
1217 	int ret = 0;
1218 
1219 	/* Some maps allow key to be unspecified. */
1220 	if (btf_key_id) {
1221 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1222 		if (!key_type || key_size != map->key_size)
1223 			return -EINVAL;
1224 	} else {
1225 		key_type = btf_type_by_id(btf, 0);
1226 		if (!map->ops->map_check_btf)
1227 			return -EINVAL;
1228 	}
1229 
1230 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1231 	if (!value_type || value_size != map->value_size)
1232 		return -EINVAL;
1233 
1234 	map->record = btf_parse_fields(btf, value_type,
1235 				       BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1236 				       BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR,
1237 				       map->value_size);
1238 	if (!IS_ERR_OR_NULL(map->record)) {
1239 		int i;
1240 
1241 		if (!bpf_token_capable(token, CAP_BPF)) {
1242 			ret = -EPERM;
1243 			goto free_map_tab;
1244 		}
1245 		if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1246 			ret = -EACCES;
1247 			goto free_map_tab;
1248 		}
1249 		for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1250 			switch (map->record->field_mask & (1 << i)) {
1251 			case 0:
1252 				continue;
1253 			case BPF_SPIN_LOCK:
1254 			case BPF_RES_SPIN_LOCK:
1255 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1256 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1257 				    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1258 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1259 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1260 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1261 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1262 					ret = -EOPNOTSUPP;
1263 					goto free_map_tab;
1264 				}
1265 				break;
1266 			case BPF_TIMER:
1267 			case BPF_WORKQUEUE:
1268 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1269 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1270 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1271 					ret = -EOPNOTSUPP;
1272 					goto free_map_tab;
1273 				}
1274 				break;
1275 			case BPF_KPTR_UNREF:
1276 			case BPF_KPTR_REF:
1277 			case BPF_KPTR_PERCPU:
1278 			case BPF_REFCOUNT:
1279 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1280 				    map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1281 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1282 				    map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1283 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1284 				    map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1285 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1286 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1287 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1288 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1289 					ret = -EOPNOTSUPP;
1290 					goto free_map_tab;
1291 				}
1292 				break;
1293 			case BPF_UPTR:
1294 				if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1295 					ret = -EOPNOTSUPP;
1296 					goto free_map_tab;
1297 				}
1298 				break;
1299 			case BPF_LIST_HEAD:
1300 			case BPF_RB_ROOT:
1301 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1302 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1303 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1304 					ret = -EOPNOTSUPP;
1305 					goto free_map_tab;
1306 				}
1307 				break;
1308 			default:
1309 				/* Fail if map_type checks are missing for a field type */
1310 				ret = -EOPNOTSUPP;
1311 				goto free_map_tab;
1312 			}
1313 		}
1314 	}
1315 
1316 	ret = btf_check_and_fixup_fields(btf, map->record);
1317 	if (ret < 0)
1318 		goto free_map_tab;
1319 
1320 	if (map->ops->map_check_btf) {
1321 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1322 		if (ret < 0)
1323 			goto free_map_tab;
1324 	}
1325 
1326 	return ret;
1327 free_map_tab:
1328 	bpf_map_free_record(map);
1329 	return ret;
1330 }
1331 
bpf_net_capable(void)1332 static bool bpf_net_capable(void)
1333 {
1334 	return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
1335 }
1336 
1337 #define BPF_MAP_CREATE_LAST_FIELD map_token_fd
1338 /* called via syscall */
map_create(union bpf_attr * attr,bool kernel)1339 static int map_create(union bpf_attr *attr, bool kernel)
1340 {
1341 	const struct bpf_map_ops *ops;
1342 	struct bpf_token *token = NULL;
1343 	int numa_node = bpf_map_attr_numa_node(attr);
1344 	u32 map_type = attr->map_type;
1345 	struct bpf_map *map;
1346 	bool token_flag;
1347 	int f_flags;
1348 	int err;
1349 
1350 	err = CHECK_ATTR(BPF_MAP_CREATE);
1351 	if (err)
1352 		return -EINVAL;
1353 
1354 	/* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1355 	 * to avoid per-map type checks tripping on unknown flag
1356 	 */
1357 	token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1358 	attr->map_flags &= ~BPF_F_TOKEN_FD;
1359 
1360 	if (attr->btf_vmlinux_value_type_id) {
1361 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1362 		    attr->btf_key_type_id || attr->btf_value_type_id)
1363 			return -EINVAL;
1364 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1365 		return -EINVAL;
1366 	}
1367 
1368 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1369 	    attr->map_type != BPF_MAP_TYPE_ARENA &&
1370 	    attr->map_extra != 0)
1371 		return -EINVAL;
1372 
1373 	f_flags = bpf_get_file_flag(attr->map_flags);
1374 	if (f_flags < 0)
1375 		return f_flags;
1376 
1377 	if (numa_node != NUMA_NO_NODE &&
1378 	    ((unsigned int)numa_node >= nr_node_ids ||
1379 	     !node_online(numa_node)))
1380 		return -EINVAL;
1381 
1382 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1383 	map_type = attr->map_type;
1384 	if (map_type >= ARRAY_SIZE(bpf_map_types))
1385 		return -EINVAL;
1386 	map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1387 	ops = bpf_map_types[map_type];
1388 	if (!ops)
1389 		return -EINVAL;
1390 
1391 	if (ops->map_alloc_check) {
1392 		err = ops->map_alloc_check(attr);
1393 		if (err)
1394 			return err;
1395 	}
1396 	if (attr->map_ifindex)
1397 		ops = &bpf_map_offload_ops;
1398 	if (!ops->map_mem_usage)
1399 		return -EINVAL;
1400 
1401 	if (token_flag) {
1402 		token = bpf_token_get_from_fd(attr->map_token_fd);
1403 		if (IS_ERR(token))
1404 			return PTR_ERR(token);
1405 
1406 		/* if current token doesn't grant map creation permissions,
1407 		 * then we can't use this token, so ignore it and rely on
1408 		 * system-wide capabilities checks
1409 		 */
1410 		if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1411 		    !bpf_token_allow_map_type(token, attr->map_type)) {
1412 			bpf_token_put(token);
1413 			token = NULL;
1414 		}
1415 	}
1416 
1417 	err = -EPERM;
1418 
1419 	/* Intent here is for unprivileged_bpf_disabled to block BPF map
1420 	 * creation for unprivileged users; other actions depend
1421 	 * on fd availability and access to bpffs, so are dependent on
1422 	 * object creation success. Even with unprivileged BPF disabled,
1423 	 * capability checks are still carried out.
1424 	 */
1425 	if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1426 		goto put_token;
1427 
1428 	/* check privileged map type permissions */
1429 	switch (map_type) {
1430 	case BPF_MAP_TYPE_ARRAY:
1431 	case BPF_MAP_TYPE_PERCPU_ARRAY:
1432 	case BPF_MAP_TYPE_PROG_ARRAY:
1433 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1434 	case BPF_MAP_TYPE_CGROUP_ARRAY:
1435 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1436 	case BPF_MAP_TYPE_HASH:
1437 	case BPF_MAP_TYPE_PERCPU_HASH:
1438 	case BPF_MAP_TYPE_HASH_OF_MAPS:
1439 	case BPF_MAP_TYPE_RINGBUF:
1440 	case BPF_MAP_TYPE_USER_RINGBUF:
1441 	case BPF_MAP_TYPE_CGROUP_STORAGE:
1442 	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1443 		/* unprivileged */
1444 		break;
1445 	case BPF_MAP_TYPE_SK_STORAGE:
1446 	case BPF_MAP_TYPE_INODE_STORAGE:
1447 	case BPF_MAP_TYPE_TASK_STORAGE:
1448 	case BPF_MAP_TYPE_CGRP_STORAGE:
1449 	case BPF_MAP_TYPE_BLOOM_FILTER:
1450 	case BPF_MAP_TYPE_LPM_TRIE:
1451 	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1452 	case BPF_MAP_TYPE_STACK_TRACE:
1453 	case BPF_MAP_TYPE_QUEUE:
1454 	case BPF_MAP_TYPE_STACK:
1455 	case BPF_MAP_TYPE_LRU_HASH:
1456 	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1457 	case BPF_MAP_TYPE_STRUCT_OPS:
1458 	case BPF_MAP_TYPE_CPUMAP:
1459 	case BPF_MAP_TYPE_ARENA:
1460 		if (!bpf_token_capable(token, CAP_BPF))
1461 			goto put_token;
1462 		break;
1463 	case BPF_MAP_TYPE_SOCKMAP:
1464 	case BPF_MAP_TYPE_SOCKHASH:
1465 	case BPF_MAP_TYPE_DEVMAP:
1466 	case BPF_MAP_TYPE_DEVMAP_HASH:
1467 	case BPF_MAP_TYPE_XSKMAP:
1468 		if (!bpf_token_capable(token, CAP_NET_ADMIN))
1469 			goto put_token;
1470 		break;
1471 	default:
1472 		WARN(1, "unsupported map type %d", map_type);
1473 		goto put_token;
1474 	}
1475 
1476 	map = ops->map_alloc(attr);
1477 	if (IS_ERR(map)) {
1478 		err = PTR_ERR(map);
1479 		goto put_token;
1480 	}
1481 	map->ops = ops;
1482 	map->map_type = map_type;
1483 
1484 	err = bpf_obj_name_cpy(map->name, attr->map_name,
1485 			       sizeof(attr->map_name));
1486 	if (err < 0)
1487 		goto free_map;
1488 
1489 	atomic64_set(&map->refcnt, 1);
1490 	atomic64_set(&map->usercnt, 1);
1491 	mutex_init(&map->freeze_mutex);
1492 	spin_lock_init(&map->owner.lock);
1493 
1494 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
1495 	    /* Even the map's value is a kernel's struct,
1496 	     * the bpf_prog.o must have BTF to begin with
1497 	     * to figure out the corresponding kernel's
1498 	     * counter part.  Thus, attr->btf_fd has
1499 	     * to be valid also.
1500 	     */
1501 	    attr->btf_vmlinux_value_type_id) {
1502 		struct btf *btf;
1503 
1504 		btf = btf_get_by_fd(attr->btf_fd);
1505 		if (IS_ERR(btf)) {
1506 			err = PTR_ERR(btf);
1507 			goto free_map;
1508 		}
1509 		if (btf_is_kernel(btf)) {
1510 			btf_put(btf);
1511 			err = -EACCES;
1512 			goto free_map;
1513 		}
1514 		map->btf = btf;
1515 
1516 		if (attr->btf_value_type_id) {
1517 			err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1518 					    attr->btf_value_type_id);
1519 			if (err)
1520 				goto free_map;
1521 		}
1522 
1523 		map->btf_key_type_id = attr->btf_key_type_id;
1524 		map->btf_value_type_id = attr->btf_value_type_id;
1525 		map->btf_vmlinux_value_type_id =
1526 			attr->btf_vmlinux_value_type_id;
1527 	}
1528 
1529 	err = security_bpf_map_create(map, attr, token, kernel);
1530 	if (err)
1531 		goto free_map_sec;
1532 
1533 	err = bpf_map_alloc_id(map);
1534 	if (err)
1535 		goto free_map_sec;
1536 
1537 	bpf_map_save_memcg(map);
1538 	bpf_token_put(token);
1539 
1540 	err = bpf_map_new_fd(map, f_flags);
1541 	if (err < 0) {
1542 		/* failed to allocate fd.
1543 		 * bpf_map_put_with_uref() is needed because the above
1544 		 * bpf_map_alloc_id() has published the map
1545 		 * to the userspace and the userspace may
1546 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1547 		 */
1548 		bpf_map_put_with_uref(map);
1549 		return err;
1550 	}
1551 
1552 	return err;
1553 
1554 free_map_sec:
1555 	security_bpf_map_free(map);
1556 free_map:
1557 	bpf_map_free(map);
1558 put_token:
1559 	bpf_token_put(token);
1560 	return err;
1561 }
1562 
bpf_map_inc(struct bpf_map * map)1563 void bpf_map_inc(struct bpf_map *map)
1564 {
1565 	atomic64_inc(&map->refcnt);
1566 }
1567 EXPORT_SYMBOL_GPL(bpf_map_inc);
1568 
bpf_map_inc_with_uref(struct bpf_map * map)1569 void bpf_map_inc_with_uref(struct bpf_map *map)
1570 {
1571 	atomic64_inc(&map->refcnt);
1572 	atomic64_inc(&map->usercnt);
1573 }
1574 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1575 
bpf_map_get(u32 ufd)1576 struct bpf_map *bpf_map_get(u32 ufd)
1577 {
1578 	CLASS(fd, f)(ufd);
1579 	struct bpf_map *map = __bpf_map_get(f);
1580 
1581 	if (!IS_ERR(map))
1582 		bpf_map_inc(map);
1583 
1584 	return map;
1585 }
1586 EXPORT_SYMBOL(bpf_map_get);
1587 
bpf_map_get_with_uref(u32 ufd)1588 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1589 {
1590 	CLASS(fd, f)(ufd);
1591 	struct bpf_map *map = __bpf_map_get(f);
1592 
1593 	if (!IS_ERR(map))
1594 		bpf_map_inc_with_uref(map);
1595 
1596 	return map;
1597 }
1598 
1599 /* map_idr_lock should have been held or the map should have been
1600  * protected by rcu read lock.
1601  */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1602 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1603 {
1604 	int refold;
1605 
1606 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1607 	if (!refold)
1608 		return ERR_PTR(-ENOENT);
1609 	if (uref)
1610 		atomic64_inc(&map->usercnt);
1611 
1612 	return map;
1613 }
1614 
bpf_map_inc_not_zero(struct bpf_map * map)1615 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1616 {
1617 	lockdep_assert(rcu_read_lock_held());
1618 	return __bpf_map_inc_not_zero(map, false);
1619 }
1620 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1621 
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1622 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1623 {
1624 	return -ENOTSUPP;
1625 }
1626 
__bpf_copy_key(void __user * ukey,u64 key_size)1627 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1628 {
1629 	if (key_size)
1630 		return vmemdup_user(ukey, key_size);
1631 
1632 	if (ukey)
1633 		return ERR_PTR(-EINVAL);
1634 
1635 	return NULL;
1636 }
1637 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1638 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1639 {
1640 	if (key_size)
1641 		return kvmemdup_bpfptr(ukey, key_size);
1642 
1643 	if (!bpfptr_is_null(ukey))
1644 		return ERR_PTR(-EINVAL);
1645 
1646 	return NULL;
1647 }
1648 
1649 /* last field in 'union bpf_attr' used by this command */
1650 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1651 
map_lookup_elem(union bpf_attr * attr)1652 static int map_lookup_elem(union bpf_attr *attr)
1653 {
1654 	void __user *ukey = u64_to_user_ptr(attr->key);
1655 	void __user *uvalue = u64_to_user_ptr(attr->value);
1656 	struct bpf_map *map;
1657 	void *key, *value;
1658 	u32 value_size;
1659 	int err;
1660 
1661 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1662 		return -EINVAL;
1663 
1664 	if (attr->flags & ~BPF_F_LOCK)
1665 		return -EINVAL;
1666 
1667 	CLASS(fd, f)(attr->map_fd);
1668 	map = __bpf_map_get(f);
1669 	if (IS_ERR(map))
1670 		return PTR_ERR(map);
1671 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1672 		return -EPERM;
1673 
1674 	if ((attr->flags & BPF_F_LOCK) &&
1675 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
1676 		return -EINVAL;
1677 
1678 	key = __bpf_copy_key(ukey, map->key_size);
1679 	if (IS_ERR(key))
1680 		return PTR_ERR(key);
1681 
1682 	value_size = bpf_map_value_size(map);
1683 
1684 	err = -ENOMEM;
1685 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1686 	if (!value)
1687 		goto free_key;
1688 
1689 	if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1690 		if (copy_from_user(value, uvalue, value_size))
1691 			err = -EFAULT;
1692 		else
1693 			err = bpf_map_copy_value(map, key, value, attr->flags);
1694 		goto free_value;
1695 	}
1696 
1697 	err = bpf_map_copy_value(map, key, value, attr->flags);
1698 	if (err)
1699 		goto free_value;
1700 
1701 	err = -EFAULT;
1702 	if (copy_to_user(uvalue, value, value_size) != 0)
1703 		goto free_value;
1704 
1705 	err = 0;
1706 
1707 free_value:
1708 	kvfree(value);
1709 free_key:
1710 	kvfree(key);
1711 	return err;
1712 }
1713 
1714 
1715 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1716 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1717 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1718 {
1719 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1720 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1721 	struct bpf_map *map;
1722 	void *key, *value;
1723 	u32 value_size;
1724 	int err;
1725 
1726 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1727 		return -EINVAL;
1728 
1729 	CLASS(fd, f)(attr->map_fd);
1730 	map = __bpf_map_get(f);
1731 	if (IS_ERR(map))
1732 		return PTR_ERR(map);
1733 	bpf_map_write_active_inc(map);
1734 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1735 		err = -EPERM;
1736 		goto err_put;
1737 	}
1738 
1739 	if ((attr->flags & BPF_F_LOCK) &&
1740 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1741 		err = -EINVAL;
1742 		goto err_put;
1743 	}
1744 
1745 	key = ___bpf_copy_key(ukey, map->key_size);
1746 	if (IS_ERR(key)) {
1747 		err = PTR_ERR(key);
1748 		goto err_put;
1749 	}
1750 
1751 	value_size = bpf_map_value_size(map);
1752 	value = kvmemdup_bpfptr(uvalue, value_size);
1753 	if (IS_ERR(value)) {
1754 		err = PTR_ERR(value);
1755 		goto free_key;
1756 	}
1757 
1758 	err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1759 	if (!err)
1760 		maybe_wait_bpf_programs(map);
1761 
1762 	kvfree(value);
1763 free_key:
1764 	kvfree(key);
1765 err_put:
1766 	bpf_map_write_active_dec(map);
1767 	return err;
1768 }
1769 
1770 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1771 
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1772 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1773 {
1774 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1775 	struct bpf_map *map;
1776 	void *key;
1777 	int err;
1778 
1779 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1780 		return -EINVAL;
1781 
1782 	CLASS(fd, f)(attr->map_fd);
1783 	map = __bpf_map_get(f);
1784 	if (IS_ERR(map))
1785 		return PTR_ERR(map);
1786 	bpf_map_write_active_inc(map);
1787 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1788 		err = -EPERM;
1789 		goto err_put;
1790 	}
1791 
1792 	key = ___bpf_copy_key(ukey, map->key_size);
1793 	if (IS_ERR(key)) {
1794 		err = PTR_ERR(key);
1795 		goto err_put;
1796 	}
1797 
1798 	if (bpf_map_is_offloaded(map)) {
1799 		err = bpf_map_offload_delete_elem(map, key);
1800 		goto out;
1801 	} else if (IS_FD_PROG_ARRAY(map) ||
1802 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1803 		/* These maps require sleepable context */
1804 		err = map->ops->map_delete_elem(map, key);
1805 		goto out;
1806 	}
1807 
1808 	bpf_disable_instrumentation();
1809 	rcu_read_lock();
1810 	err = map->ops->map_delete_elem(map, key);
1811 	rcu_read_unlock();
1812 	bpf_enable_instrumentation();
1813 	if (!err)
1814 		maybe_wait_bpf_programs(map);
1815 out:
1816 	kvfree(key);
1817 err_put:
1818 	bpf_map_write_active_dec(map);
1819 	return err;
1820 }
1821 
1822 /* last field in 'union bpf_attr' used by this command */
1823 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1824 
map_get_next_key(union bpf_attr * attr)1825 static int map_get_next_key(union bpf_attr *attr)
1826 {
1827 	void __user *ukey = u64_to_user_ptr(attr->key);
1828 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1829 	struct bpf_map *map;
1830 	void *key, *next_key;
1831 	int err;
1832 
1833 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1834 		return -EINVAL;
1835 
1836 	CLASS(fd, f)(attr->map_fd);
1837 	map = __bpf_map_get(f);
1838 	if (IS_ERR(map))
1839 		return PTR_ERR(map);
1840 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1841 		return -EPERM;
1842 
1843 	if (ukey) {
1844 		key = __bpf_copy_key(ukey, map->key_size);
1845 		if (IS_ERR(key))
1846 			return PTR_ERR(key);
1847 	} else {
1848 		key = NULL;
1849 	}
1850 
1851 	err = -ENOMEM;
1852 	next_key = kvmalloc(map->key_size, GFP_USER);
1853 	if (!next_key)
1854 		goto free_key;
1855 
1856 	if (bpf_map_is_offloaded(map)) {
1857 		err = bpf_map_offload_get_next_key(map, key, next_key);
1858 		goto out;
1859 	}
1860 
1861 	rcu_read_lock();
1862 	err = map->ops->map_get_next_key(map, key, next_key);
1863 	rcu_read_unlock();
1864 out:
1865 	if (err)
1866 		goto free_next_key;
1867 
1868 	err = -EFAULT;
1869 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1870 		goto free_next_key;
1871 
1872 	err = 0;
1873 
1874 free_next_key:
1875 	kvfree(next_key);
1876 free_key:
1877 	kvfree(key);
1878 	return err;
1879 }
1880 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1881 int generic_map_delete_batch(struct bpf_map *map,
1882 			     const union bpf_attr *attr,
1883 			     union bpf_attr __user *uattr)
1884 {
1885 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1886 	u32 cp, max_count;
1887 	int err = 0;
1888 	void *key;
1889 
1890 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1891 		return -EINVAL;
1892 
1893 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1894 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1895 		return -EINVAL;
1896 	}
1897 
1898 	max_count = attr->batch.count;
1899 	if (!max_count)
1900 		return 0;
1901 
1902 	if (put_user(0, &uattr->batch.count))
1903 		return -EFAULT;
1904 
1905 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1906 	if (!key)
1907 		return -ENOMEM;
1908 
1909 	for (cp = 0; cp < max_count; cp++) {
1910 		err = -EFAULT;
1911 		if (copy_from_user(key, keys + cp * map->key_size,
1912 				   map->key_size))
1913 			break;
1914 
1915 		if (bpf_map_is_offloaded(map)) {
1916 			err = bpf_map_offload_delete_elem(map, key);
1917 			break;
1918 		}
1919 
1920 		bpf_disable_instrumentation();
1921 		rcu_read_lock();
1922 		err = map->ops->map_delete_elem(map, key);
1923 		rcu_read_unlock();
1924 		bpf_enable_instrumentation();
1925 		if (err)
1926 			break;
1927 		cond_resched();
1928 	}
1929 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1930 		err = -EFAULT;
1931 
1932 	kvfree(key);
1933 
1934 	return err;
1935 }
1936 
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1937 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1938 			     const union bpf_attr *attr,
1939 			     union bpf_attr __user *uattr)
1940 {
1941 	void __user *values = u64_to_user_ptr(attr->batch.values);
1942 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1943 	u32 value_size, cp, max_count;
1944 	void *key, *value;
1945 	int err = 0;
1946 
1947 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1948 		return -EINVAL;
1949 
1950 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1951 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1952 		return -EINVAL;
1953 	}
1954 
1955 	value_size = bpf_map_value_size(map);
1956 
1957 	max_count = attr->batch.count;
1958 	if (!max_count)
1959 		return 0;
1960 
1961 	if (put_user(0, &uattr->batch.count))
1962 		return -EFAULT;
1963 
1964 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1965 	if (!key)
1966 		return -ENOMEM;
1967 
1968 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1969 	if (!value) {
1970 		kvfree(key);
1971 		return -ENOMEM;
1972 	}
1973 
1974 	for (cp = 0; cp < max_count; cp++) {
1975 		err = -EFAULT;
1976 		if (copy_from_user(key, keys + cp * map->key_size,
1977 		    map->key_size) ||
1978 		    copy_from_user(value, values + cp * value_size, value_size))
1979 			break;
1980 
1981 		err = bpf_map_update_value(map, map_file, key, value,
1982 					   attr->batch.elem_flags);
1983 
1984 		if (err)
1985 			break;
1986 		cond_resched();
1987 	}
1988 
1989 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1990 		err = -EFAULT;
1991 
1992 	kvfree(value);
1993 	kvfree(key);
1994 
1995 	return err;
1996 }
1997 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1998 int generic_map_lookup_batch(struct bpf_map *map,
1999 				    const union bpf_attr *attr,
2000 				    union bpf_attr __user *uattr)
2001 {
2002 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
2003 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
2004 	void __user *values = u64_to_user_ptr(attr->batch.values);
2005 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
2006 	void *buf, *buf_prevkey, *prev_key, *key, *value;
2007 	u32 value_size, cp, max_count;
2008 	int err;
2009 
2010 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
2011 		return -EINVAL;
2012 
2013 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
2014 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
2015 		return -EINVAL;
2016 
2017 	value_size = bpf_map_value_size(map);
2018 
2019 	max_count = attr->batch.count;
2020 	if (!max_count)
2021 		return 0;
2022 
2023 	if (put_user(0, &uattr->batch.count))
2024 		return -EFAULT;
2025 
2026 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2027 	if (!buf_prevkey)
2028 		return -ENOMEM;
2029 
2030 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2031 	if (!buf) {
2032 		kvfree(buf_prevkey);
2033 		return -ENOMEM;
2034 	}
2035 
2036 	err = -EFAULT;
2037 	prev_key = NULL;
2038 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2039 		goto free_buf;
2040 	key = buf;
2041 	value = key + map->key_size;
2042 	if (ubatch)
2043 		prev_key = buf_prevkey;
2044 
2045 	for (cp = 0; cp < max_count;) {
2046 		rcu_read_lock();
2047 		err = map->ops->map_get_next_key(map, prev_key, key);
2048 		rcu_read_unlock();
2049 		if (err)
2050 			break;
2051 		err = bpf_map_copy_value(map, key, value,
2052 					 attr->batch.elem_flags);
2053 
2054 		if (err == -ENOENT)
2055 			goto next_key;
2056 
2057 		if (err)
2058 			goto free_buf;
2059 
2060 		if (copy_to_user(keys + cp * map->key_size, key,
2061 				 map->key_size)) {
2062 			err = -EFAULT;
2063 			goto free_buf;
2064 		}
2065 		if (copy_to_user(values + cp * value_size, value, value_size)) {
2066 			err = -EFAULT;
2067 			goto free_buf;
2068 		}
2069 
2070 		cp++;
2071 next_key:
2072 		if (!prev_key)
2073 			prev_key = buf_prevkey;
2074 
2075 		swap(prev_key, key);
2076 		cond_resched();
2077 	}
2078 
2079 	if (err == -EFAULT)
2080 		goto free_buf;
2081 
2082 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2083 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2084 		err = -EFAULT;
2085 
2086 free_buf:
2087 	kvfree(buf_prevkey);
2088 	kvfree(buf);
2089 	return err;
2090 }
2091 
2092 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2093 
map_lookup_and_delete_elem(union bpf_attr * attr)2094 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2095 {
2096 	void __user *ukey = u64_to_user_ptr(attr->key);
2097 	void __user *uvalue = u64_to_user_ptr(attr->value);
2098 	struct bpf_map *map;
2099 	void *key, *value;
2100 	u32 value_size;
2101 	int err;
2102 
2103 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2104 		return -EINVAL;
2105 
2106 	if (attr->flags & ~BPF_F_LOCK)
2107 		return -EINVAL;
2108 
2109 	CLASS(fd, f)(attr->map_fd);
2110 	map = __bpf_map_get(f);
2111 	if (IS_ERR(map))
2112 		return PTR_ERR(map);
2113 	bpf_map_write_active_inc(map);
2114 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2115 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2116 		err = -EPERM;
2117 		goto err_put;
2118 	}
2119 
2120 	if (attr->flags &&
2121 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
2122 	     map->map_type == BPF_MAP_TYPE_STACK)) {
2123 		err = -EINVAL;
2124 		goto err_put;
2125 	}
2126 
2127 	if ((attr->flags & BPF_F_LOCK) &&
2128 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2129 		err = -EINVAL;
2130 		goto err_put;
2131 	}
2132 
2133 	key = __bpf_copy_key(ukey, map->key_size);
2134 	if (IS_ERR(key)) {
2135 		err = PTR_ERR(key);
2136 		goto err_put;
2137 	}
2138 
2139 	value_size = bpf_map_value_size(map);
2140 
2141 	err = -ENOMEM;
2142 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2143 	if (!value)
2144 		goto free_key;
2145 
2146 	err = -ENOTSUPP;
2147 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2148 	    map->map_type == BPF_MAP_TYPE_STACK) {
2149 		err = map->ops->map_pop_elem(map, value);
2150 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
2151 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2152 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2153 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
2154 		if (!bpf_map_is_offloaded(map)) {
2155 			bpf_disable_instrumentation();
2156 			rcu_read_lock();
2157 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2158 			rcu_read_unlock();
2159 			bpf_enable_instrumentation();
2160 		}
2161 	}
2162 
2163 	if (err)
2164 		goto free_value;
2165 
2166 	if (copy_to_user(uvalue, value, value_size) != 0) {
2167 		err = -EFAULT;
2168 		goto free_value;
2169 	}
2170 
2171 	err = 0;
2172 
2173 free_value:
2174 	kvfree(value);
2175 free_key:
2176 	kvfree(key);
2177 err_put:
2178 	bpf_map_write_active_dec(map);
2179 	return err;
2180 }
2181 
2182 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2183 
map_freeze(const union bpf_attr * attr)2184 static int map_freeze(const union bpf_attr *attr)
2185 {
2186 	int err = 0;
2187 	struct bpf_map *map;
2188 
2189 	if (CHECK_ATTR(BPF_MAP_FREEZE))
2190 		return -EINVAL;
2191 
2192 	CLASS(fd, f)(attr->map_fd);
2193 	map = __bpf_map_get(f);
2194 	if (IS_ERR(map))
2195 		return PTR_ERR(map);
2196 
2197 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2198 		return -ENOTSUPP;
2199 
2200 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2201 		return -EPERM;
2202 
2203 	mutex_lock(&map->freeze_mutex);
2204 	if (bpf_map_write_active(map)) {
2205 		err = -EBUSY;
2206 		goto err_put;
2207 	}
2208 	if (READ_ONCE(map->frozen)) {
2209 		err = -EBUSY;
2210 		goto err_put;
2211 	}
2212 
2213 	WRITE_ONCE(map->frozen, true);
2214 err_put:
2215 	mutex_unlock(&map->freeze_mutex);
2216 	return err;
2217 }
2218 
2219 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2220 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2221 	[_id] = & _name ## _prog_ops,
2222 #define BPF_MAP_TYPE(_id, _ops)
2223 #define BPF_LINK_TYPE(_id, _name)
2224 #include <linux/bpf_types.h>
2225 #undef BPF_PROG_TYPE
2226 #undef BPF_MAP_TYPE
2227 #undef BPF_LINK_TYPE
2228 };
2229 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2230 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2231 {
2232 	const struct bpf_prog_ops *ops;
2233 
2234 	if (type >= ARRAY_SIZE(bpf_prog_types))
2235 		return -EINVAL;
2236 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2237 	ops = bpf_prog_types[type];
2238 	if (!ops)
2239 		return -EINVAL;
2240 
2241 	if (!bpf_prog_is_offloaded(prog->aux))
2242 		prog->aux->ops = ops;
2243 	else
2244 		prog->aux->ops = &bpf_offload_prog_ops;
2245 	prog->type = type;
2246 	return 0;
2247 }
2248 
2249 enum bpf_audit {
2250 	BPF_AUDIT_LOAD,
2251 	BPF_AUDIT_UNLOAD,
2252 	BPF_AUDIT_MAX,
2253 };
2254 
2255 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2256 	[BPF_AUDIT_LOAD]   = "LOAD",
2257 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
2258 };
2259 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2260 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2261 {
2262 	struct audit_context *ctx = NULL;
2263 	struct audit_buffer *ab;
2264 
2265 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2266 		return;
2267 	if (audit_enabled == AUDIT_OFF)
2268 		return;
2269 	if (!in_irq() && !irqs_disabled())
2270 		ctx = audit_context();
2271 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2272 	if (unlikely(!ab))
2273 		return;
2274 	audit_log_format(ab, "prog-id=%u op=%s",
2275 			 prog->aux->id, bpf_audit_str[op]);
2276 	audit_log_end(ab);
2277 }
2278 
bpf_prog_alloc_id(struct bpf_prog * prog)2279 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2280 {
2281 	int id;
2282 
2283 	idr_preload(GFP_KERNEL);
2284 	spin_lock_bh(&prog_idr_lock);
2285 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2286 	if (id > 0)
2287 		prog->aux->id = id;
2288 	spin_unlock_bh(&prog_idr_lock);
2289 	idr_preload_end();
2290 
2291 	/* id is in [1, INT_MAX) */
2292 	if (WARN_ON_ONCE(!id))
2293 		return -ENOSPC;
2294 
2295 	return id > 0 ? 0 : id;
2296 }
2297 
bpf_prog_free_id(struct bpf_prog * prog)2298 void bpf_prog_free_id(struct bpf_prog *prog)
2299 {
2300 	unsigned long flags;
2301 
2302 	/* cBPF to eBPF migrations are currently not in the idr store.
2303 	 * Offloaded programs are removed from the store when their device
2304 	 * disappears - even if someone grabs an fd to them they are unusable,
2305 	 * simply waiting for refcnt to drop to be freed.
2306 	 */
2307 	if (!prog->aux->id)
2308 		return;
2309 
2310 	spin_lock_irqsave(&prog_idr_lock, flags);
2311 	idr_remove(&prog_idr, prog->aux->id);
2312 	prog->aux->id = 0;
2313 	spin_unlock_irqrestore(&prog_idr_lock, flags);
2314 }
2315 
__bpf_prog_put_rcu(struct rcu_head * rcu)2316 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2317 {
2318 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2319 
2320 	kvfree(aux->func_info);
2321 	kfree(aux->func_info_aux);
2322 	free_uid(aux->user);
2323 	security_bpf_prog_free(aux->prog);
2324 	bpf_prog_free(aux->prog);
2325 }
2326 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2327 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2328 {
2329 	bpf_prog_kallsyms_del_all(prog);
2330 	btf_put(prog->aux->btf);
2331 	module_put(prog->aux->mod);
2332 	kvfree(prog->aux->jited_linfo);
2333 	kvfree(prog->aux->linfo);
2334 	kfree(prog->aux->kfunc_tab);
2335 	kfree(prog->aux->ctx_arg_info);
2336 	if (prog->aux->attach_btf)
2337 		btf_put(prog->aux->attach_btf);
2338 
2339 	if (deferred) {
2340 		if (prog->sleepable)
2341 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2342 		else
2343 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2344 	} else {
2345 		__bpf_prog_put_rcu(&prog->aux->rcu);
2346 	}
2347 }
2348 
bpf_prog_put_deferred(struct work_struct * work)2349 static void bpf_prog_put_deferred(struct work_struct *work)
2350 {
2351 	struct bpf_prog_aux *aux;
2352 	struct bpf_prog *prog;
2353 
2354 	aux = container_of(work, struct bpf_prog_aux, work);
2355 	prog = aux->prog;
2356 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2357 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2358 	bpf_prog_free_id(prog);
2359 	__bpf_prog_put_noref(prog, true);
2360 }
2361 
__bpf_prog_put(struct bpf_prog * prog)2362 static void __bpf_prog_put(struct bpf_prog *prog)
2363 {
2364 	struct bpf_prog_aux *aux = prog->aux;
2365 
2366 	if (atomic64_dec_and_test(&aux->refcnt)) {
2367 		if (in_irq() || irqs_disabled()) {
2368 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
2369 			schedule_work(&aux->work);
2370 		} else {
2371 			bpf_prog_put_deferred(&aux->work);
2372 		}
2373 	}
2374 }
2375 
bpf_prog_put(struct bpf_prog * prog)2376 void bpf_prog_put(struct bpf_prog *prog)
2377 {
2378 	__bpf_prog_put(prog);
2379 }
2380 EXPORT_SYMBOL_GPL(bpf_prog_put);
2381 
bpf_prog_release(struct inode * inode,struct file * filp)2382 static int bpf_prog_release(struct inode *inode, struct file *filp)
2383 {
2384 	struct bpf_prog *prog = filp->private_data;
2385 
2386 	bpf_prog_put(prog);
2387 	return 0;
2388 }
2389 
2390 struct bpf_prog_kstats {
2391 	u64 nsecs;
2392 	u64 cnt;
2393 	u64 misses;
2394 };
2395 
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2396 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2397 {
2398 	struct bpf_prog_stats *stats;
2399 	unsigned int flags;
2400 
2401 	stats = this_cpu_ptr(prog->stats);
2402 	flags = u64_stats_update_begin_irqsave(&stats->syncp);
2403 	u64_stats_inc(&stats->misses);
2404 	u64_stats_update_end_irqrestore(&stats->syncp, flags);
2405 }
2406 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2407 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2408 			       struct bpf_prog_kstats *stats)
2409 {
2410 	u64 nsecs = 0, cnt = 0, misses = 0;
2411 	int cpu;
2412 
2413 	for_each_possible_cpu(cpu) {
2414 		const struct bpf_prog_stats *st;
2415 		unsigned int start;
2416 		u64 tnsecs, tcnt, tmisses;
2417 
2418 		st = per_cpu_ptr(prog->stats, cpu);
2419 		do {
2420 			start = u64_stats_fetch_begin(&st->syncp);
2421 			tnsecs = u64_stats_read(&st->nsecs);
2422 			tcnt = u64_stats_read(&st->cnt);
2423 			tmisses = u64_stats_read(&st->misses);
2424 		} while (u64_stats_fetch_retry(&st->syncp, start));
2425 		nsecs += tnsecs;
2426 		cnt += tcnt;
2427 		misses += tmisses;
2428 	}
2429 	stats->nsecs = nsecs;
2430 	stats->cnt = cnt;
2431 	stats->misses = misses;
2432 }
2433 
2434 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2435 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2436 {
2437 	const struct bpf_prog *prog = filp->private_data;
2438 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2439 	struct bpf_prog_kstats stats;
2440 
2441 	bpf_prog_get_stats(prog, &stats);
2442 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2443 	seq_printf(m,
2444 		   "prog_type:\t%u\n"
2445 		   "prog_jited:\t%u\n"
2446 		   "prog_tag:\t%s\n"
2447 		   "memlock:\t%llu\n"
2448 		   "prog_id:\t%u\n"
2449 		   "run_time_ns:\t%llu\n"
2450 		   "run_cnt:\t%llu\n"
2451 		   "recursion_misses:\t%llu\n"
2452 		   "verified_insns:\t%u\n",
2453 		   prog->type,
2454 		   prog->jited,
2455 		   prog_tag,
2456 		   prog->pages * 1ULL << PAGE_SHIFT,
2457 		   prog->aux->id,
2458 		   stats.nsecs,
2459 		   stats.cnt,
2460 		   stats.misses,
2461 		   prog->aux->verified_insns);
2462 }
2463 #endif
2464 
2465 const struct file_operations bpf_prog_fops = {
2466 #ifdef CONFIG_PROC_FS
2467 	.show_fdinfo	= bpf_prog_show_fdinfo,
2468 #endif
2469 	.release	= bpf_prog_release,
2470 	.read		= bpf_dummy_read,
2471 	.write		= bpf_dummy_write,
2472 };
2473 
bpf_prog_new_fd(struct bpf_prog * prog)2474 int bpf_prog_new_fd(struct bpf_prog *prog)
2475 {
2476 	int ret;
2477 
2478 	ret = security_bpf_prog(prog);
2479 	if (ret < 0)
2480 		return ret;
2481 
2482 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2483 				O_RDWR | O_CLOEXEC);
2484 }
2485 
bpf_prog_add(struct bpf_prog * prog,int i)2486 void bpf_prog_add(struct bpf_prog *prog, int i)
2487 {
2488 	atomic64_add(i, &prog->aux->refcnt);
2489 }
2490 EXPORT_SYMBOL_GPL(bpf_prog_add);
2491 
bpf_prog_sub(struct bpf_prog * prog,int i)2492 void bpf_prog_sub(struct bpf_prog *prog, int i)
2493 {
2494 	/* Only to be used for undoing previous bpf_prog_add() in some
2495 	 * error path. We still know that another entity in our call
2496 	 * path holds a reference to the program, thus atomic_sub() can
2497 	 * be safely used in such cases!
2498 	 */
2499 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2500 }
2501 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2502 
bpf_prog_inc(struct bpf_prog * prog)2503 void bpf_prog_inc(struct bpf_prog *prog)
2504 {
2505 	atomic64_inc(&prog->aux->refcnt);
2506 }
2507 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2508 
2509 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2510 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2511 {
2512 	int refold;
2513 
2514 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2515 
2516 	if (!refold)
2517 		return ERR_PTR(-ENOENT);
2518 
2519 	return prog;
2520 }
2521 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2522 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2523 bool bpf_prog_get_ok(struct bpf_prog *prog,
2524 			    enum bpf_prog_type *attach_type, bool attach_drv)
2525 {
2526 	/* not an attachment, just a refcount inc, always allow */
2527 	if (!attach_type)
2528 		return true;
2529 
2530 	if (prog->type != *attach_type)
2531 		return false;
2532 	if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2533 		return false;
2534 
2535 	return true;
2536 }
2537 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2538 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2539 				       bool attach_drv)
2540 {
2541 	CLASS(fd, f)(ufd);
2542 	struct bpf_prog *prog;
2543 
2544 	if (fd_empty(f))
2545 		return ERR_PTR(-EBADF);
2546 	if (fd_file(f)->f_op != &bpf_prog_fops)
2547 		return ERR_PTR(-EINVAL);
2548 
2549 	prog = fd_file(f)->private_data;
2550 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2551 		return ERR_PTR(-EINVAL);
2552 
2553 	bpf_prog_inc(prog);
2554 	return prog;
2555 }
2556 
bpf_prog_get(u32 ufd)2557 struct bpf_prog *bpf_prog_get(u32 ufd)
2558 {
2559 	return __bpf_prog_get(ufd, NULL, false);
2560 }
2561 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2562 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2563 				       bool attach_drv)
2564 {
2565 	return __bpf_prog_get(ufd, &type, attach_drv);
2566 }
2567 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2568 
2569 /* Initially all BPF programs could be loaded w/o specifying
2570  * expected_attach_type. Later for some of them specifying expected_attach_type
2571  * at load time became required so that program could be validated properly.
2572  * Programs of types that are allowed to be loaded both w/ and w/o (for
2573  * backward compatibility) expected_attach_type, should have the default attach
2574  * type assigned to expected_attach_type for the latter case, so that it can be
2575  * validated later at attach time.
2576  *
2577  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2578  * prog type requires it but has some attach types that have to be backward
2579  * compatible.
2580  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2581 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2582 {
2583 	switch (attr->prog_type) {
2584 	case BPF_PROG_TYPE_CGROUP_SOCK:
2585 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2586 		 * exist so checking for non-zero is the way to go here.
2587 		 */
2588 		if (!attr->expected_attach_type)
2589 			attr->expected_attach_type =
2590 				BPF_CGROUP_INET_SOCK_CREATE;
2591 		break;
2592 	case BPF_PROG_TYPE_SK_REUSEPORT:
2593 		if (!attr->expected_attach_type)
2594 			attr->expected_attach_type =
2595 				BPF_SK_REUSEPORT_SELECT;
2596 		break;
2597 	}
2598 }
2599 
2600 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)2601 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2602 			   enum bpf_attach_type expected_attach_type,
2603 			   struct btf *attach_btf, u32 btf_id,
2604 			   struct bpf_prog *dst_prog)
2605 {
2606 	if (btf_id) {
2607 		if (btf_id > BTF_MAX_TYPE)
2608 			return -EINVAL;
2609 
2610 		if (!attach_btf && !dst_prog)
2611 			return -EINVAL;
2612 
2613 		switch (prog_type) {
2614 		case BPF_PROG_TYPE_TRACING:
2615 		case BPF_PROG_TYPE_LSM:
2616 		case BPF_PROG_TYPE_STRUCT_OPS:
2617 		case BPF_PROG_TYPE_EXT:
2618 			break;
2619 		default:
2620 			return -EINVAL;
2621 		}
2622 	}
2623 
2624 	if (attach_btf && (!btf_id || dst_prog))
2625 		return -EINVAL;
2626 
2627 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2628 	    prog_type != BPF_PROG_TYPE_EXT)
2629 		return -EINVAL;
2630 
2631 	switch (prog_type) {
2632 	case BPF_PROG_TYPE_CGROUP_SOCK:
2633 		switch (expected_attach_type) {
2634 		case BPF_CGROUP_INET_SOCK_CREATE:
2635 		case BPF_CGROUP_INET_SOCK_RELEASE:
2636 		case BPF_CGROUP_INET4_POST_BIND:
2637 		case BPF_CGROUP_INET6_POST_BIND:
2638 			return 0;
2639 		default:
2640 			return -EINVAL;
2641 		}
2642 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2643 		switch (expected_attach_type) {
2644 		case BPF_CGROUP_INET4_BIND:
2645 		case BPF_CGROUP_INET6_BIND:
2646 		case BPF_CGROUP_INET4_CONNECT:
2647 		case BPF_CGROUP_INET6_CONNECT:
2648 		case BPF_CGROUP_UNIX_CONNECT:
2649 		case BPF_CGROUP_INET4_GETPEERNAME:
2650 		case BPF_CGROUP_INET6_GETPEERNAME:
2651 		case BPF_CGROUP_UNIX_GETPEERNAME:
2652 		case BPF_CGROUP_INET4_GETSOCKNAME:
2653 		case BPF_CGROUP_INET6_GETSOCKNAME:
2654 		case BPF_CGROUP_UNIX_GETSOCKNAME:
2655 		case BPF_CGROUP_UDP4_SENDMSG:
2656 		case BPF_CGROUP_UDP6_SENDMSG:
2657 		case BPF_CGROUP_UNIX_SENDMSG:
2658 		case BPF_CGROUP_UDP4_RECVMSG:
2659 		case BPF_CGROUP_UDP6_RECVMSG:
2660 		case BPF_CGROUP_UNIX_RECVMSG:
2661 			return 0;
2662 		default:
2663 			return -EINVAL;
2664 		}
2665 	case BPF_PROG_TYPE_CGROUP_SKB:
2666 		switch (expected_attach_type) {
2667 		case BPF_CGROUP_INET_INGRESS:
2668 		case BPF_CGROUP_INET_EGRESS:
2669 			return 0;
2670 		default:
2671 			return -EINVAL;
2672 		}
2673 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2674 		switch (expected_attach_type) {
2675 		case BPF_CGROUP_SETSOCKOPT:
2676 		case BPF_CGROUP_GETSOCKOPT:
2677 			return 0;
2678 		default:
2679 			return -EINVAL;
2680 		}
2681 	case BPF_PROG_TYPE_SK_LOOKUP:
2682 		if (expected_attach_type == BPF_SK_LOOKUP)
2683 			return 0;
2684 		return -EINVAL;
2685 	case BPF_PROG_TYPE_SK_REUSEPORT:
2686 		switch (expected_attach_type) {
2687 		case BPF_SK_REUSEPORT_SELECT:
2688 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2689 			return 0;
2690 		default:
2691 			return -EINVAL;
2692 		}
2693 	case BPF_PROG_TYPE_NETFILTER:
2694 		if (expected_attach_type == BPF_NETFILTER)
2695 			return 0;
2696 		return -EINVAL;
2697 	case BPF_PROG_TYPE_SYSCALL:
2698 	case BPF_PROG_TYPE_EXT:
2699 		if (expected_attach_type)
2700 			return -EINVAL;
2701 		fallthrough;
2702 	default:
2703 		return 0;
2704 	}
2705 }
2706 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2707 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2708 {
2709 	switch (prog_type) {
2710 	case BPF_PROG_TYPE_SCHED_CLS:
2711 	case BPF_PROG_TYPE_SCHED_ACT:
2712 	case BPF_PROG_TYPE_XDP:
2713 	case BPF_PROG_TYPE_LWT_IN:
2714 	case BPF_PROG_TYPE_LWT_OUT:
2715 	case BPF_PROG_TYPE_LWT_XMIT:
2716 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2717 	case BPF_PROG_TYPE_SK_SKB:
2718 	case BPF_PROG_TYPE_SK_MSG:
2719 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2720 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2721 	case BPF_PROG_TYPE_CGROUP_SOCK:
2722 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2723 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2724 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2725 	case BPF_PROG_TYPE_SOCK_OPS:
2726 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2727 	case BPF_PROG_TYPE_NETFILTER:
2728 		return true;
2729 	case BPF_PROG_TYPE_CGROUP_SKB:
2730 		/* always unpriv */
2731 	case BPF_PROG_TYPE_SK_REUSEPORT:
2732 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2733 	default:
2734 		return false;
2735 	}
2736 }
2737 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2738 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2739 {
2740 	switch (prog_type) {
2741 	case BPF_PROG_TYPE_KPROBE:
2742 	case BPF_PROG_TYPE_TRACEPOINT:
2743 	case BPF_PROG_TYPE_PERF_EVENT:
2744 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2745 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2746 	case BPF_PROG_TYPE_TRACING:
2747 	case BPF_PROG_TYPE_LSM:
2748 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2749 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2750 		return true;
2751 	default:
2752 		return false;
2753 	}
2754 }
2755 
2756 /* last field in 'union bpf_attr' used by this command */
2757 #define BPF_PROG_LOAD_LAST_FIELD fd_array_cnt
2758 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2759 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2760 {
2761 	enum bpf_prog_type type = attr->prog_type;
2762 	struct bpf_prog *prog, *dst_prog = NULL;
2763 	struct btf *attach_btf = NULL;
2764 	struct bpf_token *token = NULL;
2765 	bool bpf_cap;
2766 	int err;
2767 	char license[128];
2768 
2769 	if (CHECK_ATTR(BPF_PROG_LOAD))
2770 		return -EINVAL;
2771 
2772 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2773 				 BPF_F_ANY_ALIGNMENT |
2774 				 BPF_F_TEST_STATE_FREQ |
2775 				 BPF_F_SLEEPABLE |
2776 				 BPF_F_TEST_RND_HI32 |
2777 				 BPF_F_XDP_HAS_FRAGS |
2778 				 BPF_F_XDP_DEV_BOUND_ONLY |
2779 				 BPF_F_TEST_REG_INVARIANTS |
2780 				 BPF_F_TOKEN_FD))
2781 		return -EINVAL;
2782 
2783 	bpf_prog_load_fixup_attach_type(attr);
2784 
2785 	if (attr->prog_flags & BPF_F_TOKEN_FD) {
2786 		token = bpf_token_get_from_fd(attr->prog_token_fd);
2787 		if (IS_ERR(token))
2788 			return PTR_ERR(token);
2789 		/* if current token doesn't grant prog loading permissions,
2790 		 * then we can't use this token, so ignore it and rely on
2791 		 * system-wide capabilities checks
2792 		 */
2793 		if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2794 		    !bpf_token_allow_prog_type(token, attr->prog_type,
2795 					       attr->expected_attach_type)) {
2796 			bpf_token_put(token);
2797 			token = NULL;
2798 		}
2799 	}
2800 
2801 	bpf_cap = bpf_token_capable(token, CAP_BPF);
2802 	err = -EPERM;
2803 
2804 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2805 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2806 	    !bpf_cap)
2807 		goto put_token;
2808 
2809 	/* Intent here is for unprivileged_bpf_disabled to block BPF program
2810 	 * creation for unprivileged users; other actions depend
2811 	 * on fd availability and access to bpffs, so are dependent on
2812 	 * object creation success. Even with unprivileged BPF disabled,
2813 	 * capability checks are still carried out for these
2814 	 * and other operations.
2815 	 */
2816 	if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2817 		goto put_token;
2818 
2819 	if (attr->insn_cnt == 0 ||
2820 	    attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2821 		err = -E2BIG;
2822 		goto put_token;
2823 	}
2824 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2825 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2826 	    !bpf_cap)
2827 		goto put_token;
2828 
2829 	if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2830 		goto put_token;
2831 	if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2832 		goto put_token;
2833 
2834 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2835 	 * or btf, we need to check which one it is
2836 	 */
2837 	if (attr->attach_prog_fd) {
2838 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2839 		if (IS_ERR(dst_prog)) {
2840 			dst_prog = NULL;
2841 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2842 			if (IS_ERR(attach_btf)) {
2843 				err = -EINVAL;
2844 				goto put_token;
2845 			}
2846 			if (!btf_is_kernel(attach_btf)) {
2847 				/* attaching through specifying bpf_prog's BTF
2848 				 * objects directly might be supported eventually
2849 				 */
2850 				btf_put(attach_btf);
2851 				err = -ENOTSUPP;
2852 				goto put_token;
2853 			}
2854 		}
2855 	} else if (attr->attach_btf_id) {
2856 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2857 		attach_btf = bpf_get_btf_vmlinux();
2858 		if (IS_ERR(attach_btf)) {
2859 			err = PTR_ERR(attach_btf);
2860 			goto put_token;
2861 		}
2862 		if (!attach_btf) {
2863 			err = -EINVAL;
2864 			goto put_token;
2865 		}
2866 		btf_get(attach_btf);
2867 	}
2868 
2869 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2870 				       attach_btf, attr->attach_btf_id,
2871 				       dst_prog)) {
2872 		if (dst_prog)
2873 			bpf_prog_put(dst_prog);
2874 		if (attach_btf)
2875 			btf_put(attach_btf);
2876 		err = -EINVAL;
2877 		goto put_token;
2878 	}
2879 
2880 	/* plain bpf_prog allocation */
2881 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2882 	if (!prog) {
2883 		if (dst_prog)
2884 			bpf_prog_put(dst_prog);
2885 		if (attach_btf)
2886 			btf_put(attach_btf);
2887 		err = -EINVAL;
2888 		goto put_token;
2889 	}
2890 
2891 	prog->expected_attach_type = attr->expected_attach_type;
2892 	prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
2893 	prog->aux->attach_btf = attach_btf;
2894 	prog->aux->attach_btf_id = attr->attach_btf_id;
2895 	prog->aux->dst_prog = dst_prog;
2896 	prog->aux->dev_bound = !!attr->prog_ifindex;
2897 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
2898 
2899 	/* move token into prog->aux, reuse taken refcnt */
2900 	prog->aux->token = token;
2901 	token = NULL;
2902 
2903 	prog->aux->user = get_current_user();
2904 	prog->len = attr->insn_cnt;
2905 
2906 	err = -EFAULT;
2907 	if (copy_from_bpfptr(prog->insns,
2908 			     make_bpfptr(attr->insns, uattr.is_kernel),
2909 			     bpf_prog_insn_size(prog)) != 0)
2910 		goto free_prog;
2911 	/* copy eBPF program license from user space */
2912 	if (strncpy_from_bpfptr(license,
2913 				make_bpfptr(attr->license, uattr.is_kernel),
2914 				sizeof(license) - 1) < 0)
2915 		goto free_prog;
2916 	license[sizeof(license) - 1] = 0;
2917 
2918 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
2919 	prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
2920 
2921 	prog->orig_prog = NULL;
2922 	prog->jited = 0;
2923 
2924 	atomic64_set(&prog->aux->refcnt, 1);
2925 
2926 	if (bpf_prog_is_dev_bound(prog->aux)) {
2927 		err = bpf_prog_dev_bound_init(prog, attr);
2928 		if (err)
2929 			goto free_prog;
2930 	}
2931 
2932 	if (type == BPF_PROG_TYPE_EXT && dst_prog &&
2933 	    bpf_prog_is_dev_bound(dst_prog->aux)) {
2934 		err = bpf_prog_dev_bound_inherit(prog, dst_prog);
2935 		if (err)
2936 			goto free_prog;
2937 	}
2938 
2939 	/*
2940 	 * Bookkeeping for managing the program attachment chain.
2941 	 *
2942 	 * It might be tempting to set attach_tracing_prog flag at the attachment
2943 	 * time, but this will not prevent from loading bunch of tracing prog
2944 	 * first, then attach them one to another.
2945 	 *
2946 	 * The flag attach_tracing_prog is set for the whole program lifecycle, and
2947 	 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
2948 	 * programs cannot change attachment target.
2949 	 */
2950 	if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
2951 	    dst_prog->type == BPF_PROG_TYPE_TRACING) {
2952 		prog->aux->attach_tracing_prog = true;
2953 	}
2954 
2955 	/* find program type: socket_filter vs tracing_filter */
2956 	err = find_prog_type(type, prog);
2957 	if (err < 0)
2958 		goto free_prog;
2959 
2960 	prog->aux->load_time = ktime_get_boottime_ns();
2961 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2962 			       sizeof(attr->prog_name));
2963 	if (err < 0)
2964 		goto free_prog;
2965 
2966 	err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel);
2967 	if (err)
2968 		goto free_prog_sec;
2969 
2970 	/* run eBPF verifier */
2971 	err = bpf_check(&prog, attr, uattr, uattr_size);
2972 	if (err < 0)
2973 		goto free_used_maps;
2974 
2975 	prog = bpf_prog_select_runtime(prog, &err);
2976 	if (err < 0)
2977 		goto free_used_maps;
2978 
2979 	err = bpf_prog_alloc_id(prog);
2980 	if (err)
2981 		goto free_used_maps;
2982 
2983 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
2984 	 * effectively publicly exposed. However, retrieving via
2985 	 * bpf_prog_get_fd_by_id() will take another reference,
2986 	 * therefore it cannot be gone underneath us.
2987 	 *
2988 	 * Only for the time /after/ successful bpf_prog_new_fd()
2989 	 * and before returning to userspace, we might just hold
2990 	 * one reference and any parallel close on that fd could
2991 	 * rip everything out. Hence, below notifications must
2992 	 * happen before bpf_prog_new_fd().
2993 	 *
2994 	 * Also, any failure handling from this point onwards must
2995 	 * be using bpf_prog_put() given the program is exposed.
2996 	 */
2997 	bpf_prog_kallsyms_add(prog);
2998 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2999 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3000 
3001 	err = bpf_prog_new_fd(prog);
3002 	if (err < 0)
3003 		bpf_prog_put(prog);
3004 	return err;
3005 
3006 free_used_maps:
3007 	/* In case we have subprogs, we need to wait for a grace
3008 	 * period before we can tear down JIT memory since symbols
3009 	 * are already exposed under kallsyms.
3010 	 */
3011 	__bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3012 	return err;
3013 
3014 free_prog_sec:
3015 	security_bpf_prog_free(prog);
3016 free_prog:
3017 	free_uid(prog->aux->user);
3018 	if (prog->aux->attach_btf)
3019 		btf_put(prog->aux->attach_btf);
3020 	bpf_prog_free(prog);
3021 put_token:
3022 	bpf_token_put(token);
3023 	return err;
3024 }
3025 
3026 #define BPF_OBJ_LAST_FIELD path_fd
3027 
bpf_obj_pin(const union bpf_attr * attr)3028 static int bpf_obj_pin(const union bpf_attr *attr)
3029 {
3030 	int path_fd;
3031 
3032 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3033 		return -EINVAL;
3034 
3035 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3036 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3037 		return -EINVAL;
3038 
3039 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3040 	return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3041 				u64_to_user_ptr(attr->pathname));
3042 }
3043 
bpf_obj_get(const union bpf_attr * attr)3044 static int bpf_obj_get(const union bpf_attr *attr)
3045 {
3046 	int path_fd;
3047 
3048 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3049 	    attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3050 		return -EINVAL;
3051 
3052 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3053 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3054 		return -EINVAL;
3055 
3056 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3057 	return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3058 				attr->file_flags);
3059 }
3060 
3061 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3062  * "sleepable" semantics, which normally would mean that BPF link's attach
3063  * hook can dereference link or link's underlying program for some time after
3064  * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3065  * BPF program itself can be non-sleepable, yet, because it's transitively
3066  * reachable through BPF link, its freeing has to be delayed until after RCU
3067  * Tasks Trace GP.
3068  */
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)3069 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3070 			     const struct bpf_link_ops *ops, struct bpf_prog *prog,
3071 			     bool sleepable)
3072 {
3073 	WARN_ON(ops->dealloc && ops->dealloc_deferred);
3074 	atomic64_set(&link->refcnt, 1);
3075 	link->type = type;
3076 	link->sleepable = sleepable;
3077 	link->id = 0;
3078 	link->ops = ops;
3079 	link->prog = prog;
3080 }
3081 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)3082 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3083 		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
3084 {
3085 	bpf_link_init_sleepable(link, type, ops, prog, false);
3086 }
3087 
bpf_link_free_id(int id)3088 static void bpf_link_free_id(int id)
3089 {
3090 	if (!id)
3091 		return;
3092 
3093 	spin_lock_bh(&link_idr_lock);
3094 	idr_remove(&link_idr, id);
3095 	spin_unlock_bh(&link_idr_lock);
3096 }
3097 
3098 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3099  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3100  * anon_inode's release() call. This helper marks bpf_link as
3101  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3102  * is not decremented, it's the responsibility of a calling code that failed
3103  * to complete bpf_link initialization.
3104  * This helper eventually calls link's dealloc callback, but does not call
3105  * link's release callback.
3106  */
bpf_link_cleanup(struct bpf_link_primer * primer)3107 void bpf_link_cleanup(struct bpf_link_primer *primer)
3108 {
3109 	primer->link->prog = NULL;
3110 	bpf_link_free_id(primer->id);
3111 	fput(primer->file);
3112 	put_unused_fd(primer->fd);
3113 }
3114 
bpf_link_inc(struct bpf_link * link)3115 void bpf_link_inc(struct bpf_link *link)
3116 {
3117 	atomic64_inc(&link->refcnt);
3118 }
3119 
bpf_link_dealloc(struct bpf_link * link)3120 static void bpf_link_dealloc(struct bpf_link *link)
3121 {
3122 	/* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3123 	if (link->prog)
3124 		bpf_prog_put(link->prog);
3125 
3126 	/* free bpf_link and its containing memory */
3127 	if (link->ops->dealloc_deferred)
3128 		link->ops->dealloc_deferred(link);
3129 	else
3130 		link->ops->dealloc(link);
3131 }
3132 
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3133 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3134 {
3135 	struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3136 
3137 	bpf_link_dealloc(link);
3138 }
3139 
bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head * rcu)3140 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
3141 {
3142 	if (rcu_trace_implies_rcu_gp())
3143 		bpf_link_defer_dealloc_rcu_gp(rcu);
3144 	else
3145 		call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
3146 }
3147 
3148 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3149 static void bpf_link_free(struct bpf_link *link)
3150 {
3151 	const struct bpf_link_ops *ops = link->ops;
3152 
3153 	bpf_link_free_id(link->id);
3154 	/* detach BPF program, clean up used resources */
3155 	if (link->prog)
3156 		ops->release(link);
3157 	if (ops->dealloc_deferred) {
3158 		/* Schedule BPF link deallocation, which will only then
3159 		 * trigger putting BPF program refcount.
3160 		 * If underlying BPF program is sleepable or BPF link's target
3161 		 * attach hookpoint is sleepable or otherwise requires RCU GPs
3162 		 * to ensure link and its underlying BPF program is not
3163 		 * reachable anymore, we need to first wait for RCU tasks
3164 		 * trace sync, and then go through "classic" RCU grace period
3165 		 */
3166 		if (link->sleepable || (link->prog && link->prog->sleepable))
3167 			call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
3168 		else
3169 			call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3170 	} else if (ops->dealloc) {
3171 		bpf_link_dealloc(link);
3172 	}
3173 }
3174 
bpf_link_put_deferred(struct work_struct * work)3175 static void bpf_link_put_deferred(struct work_struct *work)
3176 {
3177 	struct bpf_link *link = container_of(work, struct bpf_link, work);
3178 
3179 	bpf_link_free(link);
3180 }
3181 
3182 /* bpf_link_put might be called from atomic context. It needs to be called
3183  * from sleepable context in order to acquire sleeping locks during the process.
3184  */
bpf_link_put(struct bpf_link * link)3185 void bpf_link_put(struct bpf_link *link)
3186 {
3187 	if (!atomic64_dec_and_test(&link->refcnt))
3188 		return;
3189 
3190 	INIT_WORK(&link->work, bpf_link_put_deferred);
3191 	schedule_work(&link->work);
3192 }
3193 EXPORT_SYMBOL(bpf_link_put);
3194 
bpf_link_put_direct(struct bpf_link * link)3195 static void bpf_link_put_direct(struct bpf_link *link)
3196 {
3197 	if (!atomic64_dec_and_test(&link->refcnt))
3198 		return;
3199 	bpf_link_free(link);
3200 }
3201 
bpf_link_release(struct inode * inode,struct file * filp)3202 static int bpf_link_release(struct inode *inode, struct file *filp)
3203 {
3204 	struct bpf_link *link = filp->private_data;
3205 
3206 	bpf_link_put_direct(link);
3207 	return 0;
3208 }
3209 
3210 #ifdef CONFIG_PROC_FS
3211 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3212 #define BPF_MAP_TYPE(_id, _ops)
3213 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3214 static const char *bpf_link_type_strs[] = {
3215 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3216 #include <linux/bpf_types.h>
3217 };
3218 #undef BPF_PROG_TYPE
3219 #undef BPF_MAP_TYPE
3220 #undef BPF_LINK_TYPE
3221 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3222 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3223 {
3224 	const struct bpf_link *link = filp->private_data;
3225 	const struct bpf_prog *prog = link->prog;
3226 	enum bpf_link_type type = link->type;
3227 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3228 
3229 	if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3230 		seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3231 	} else {
3232 		WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3233 		seq_printf(m, "link_type:\t<%u>\n", type);
3234 	}
3235 	seq_printf(m, "link_id:\t%u\n", link->id);
3236 
3237 	if (prog) {
3238 		bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3239 		seq_printf(m,
3240 			   "prog_tag:\t%s\n"
3241 			   "prog_id:\t%u\n",
3242 			   prog_tag,
3243 			   prog->aux->id);
3244 	}
3245 	if (link->ops->show_fdinfo)
3246 		link->ops->show_fdinfo(link, m);
3247 }
3248 #endif
3249 
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3250 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3251 {
3252 	struct bpf_link *link = file->private_data;
3253 
3254 	return link->ops->poll(file, pts);
3255 }
3256 
3257 static const struct file_operations bpf_link_fops = {
3258 #ifdef CONFIG_PROC_FS
3259 	.show_fdinfo	= bpf_link_show_fdinfo,
3260 #endif
3261 	.release	= bpf_link_release,
3262 	.read		= bpf_dummy_read,
3263 	.write		= bpf_dummy_write,
3264 };
3265 
3266 static const struct file_operations bpf_link_fops_poll = {
3267 #ifdef CONFIG_PROC_FS
3268 	.show_fdinfo	= bpf_link_show_fdinfo,
3269 #endif
3270 	.release	= bpf_link_release,
3271 	.read		= bpf_dummy_read,
3272 	.write		= bpf_dummy_write,
3273 	.poll		= bpf_link_poll,
3274 };
3275 
bpf_link_alloc_id(struct bpf_link * link)3276 static int bpf_link_alloc_id(struct bpf_link *link)
3277 {
3278 	int id;
3279 
3280 	idr_preload(GFP_KERNEL);
3281 	spin_lock_bh(&link_idr_lock);
3282 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3283 	spin_unlock_bh(&link_idr_lock);
3284 	idr_preload_end();
3285 
3286 	return id;
3287 }
3288 
3289 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3290  * reserving unused FD and allocating ID from link_idr. This is to be paired
3291  * with bpf_link_settle() to install FD and ID and expose bpf_link to
3292  * user-space, if bpf_link is successfully attached. If not, bpf_link and
3293  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3294  * transient state is passed around in struct bpf_link_primer.
3295  * This is preferred way to create and initialize bpf_link, especially when
3296  * there are complicated and expensive operations in between creating bpf_link
3297  * itself and attaching it to BPF hook. By using bpf_link_prime() and
3298  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3299  * expensive (and potentially failing) roll back operations in a rare case
3300  * that file, FD, or ID can't be allocated.
3301  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3302 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3303 {
3304 	struct file *file;
3305 	int fd, id;
3306 
3307 	fd = get_unused_fd_flags(O_CLOEXEC);
3308 	if (fd < 0)
3309 		return fd;
3310 
3311 
3312 	id = bpf_link_alloc_id(link);
3313 	if (id < 0) {
3314 		put_unused_fd(fd);
3315 		return id;
3316 	}
3317 
3318 	file = anon_inode_getfile("bpf_link",
3319 				  link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3320 				  link, O_CLOEXEC);
3321 	if (IS_ERR(file)) {
3322 		bpf_link_free_id(id);
3323 		put_unused_fd(fd);
3324 		return PTR_ERR(file);
3325 	}
3326 
3327 	primer->link = link;
3328 	primer->file = file;
3329 	primer->fd = fd;
3330 	primer->id = id;
3331 	return 0;
3332 }
3333 
bpf_link_settle(struct bpf_link_primer * primer)3334 int bpf_link_settle(struct bpf_link_primer *primer)
3335 {
3336 	/* make bpf_link fetchable by ID */
3337 	spin_lock_bh(&link_idr_lock);
3338 	primer->link->id = primer->id;
3339 	spin_unlock_bh(&link_idr_lock);
3340 	/* make bpf_link fetchable by FD */
3341 	fd_install(primer->fd, primer->file);
3342 	/* pass through installed FD */
3343 	return primer->fd;
3344 }
3345 
bpf_link_new_fd(struct bpf_link * link)3346 int bpf_link_new_fd(struct bpf_link *link)
3347 {
3348 	return anon_inode_getfd("bpf-link",
3349 				link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3350 				link, O_CLOEXEC);
3351 }
3352 
bpf_link_get_from_fd(u32 ufd)3353 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3354 {
3355 	CLASS(fd, f)(ufd);
3356 	struct bpf_link *link;
3357 
3358 	if (fd_empty(f))
3359 		return ERR_PTR(-EBADF);
3360 	if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3361 		return ERR_PTR(-EINVAL);
3362 
3363 	link = fd_file(f)->private_data;
3364 	bpf_link_inc(link);
3365 	return link;
3366 }
3367 EXPORT_SYMBOL(bpf_link_get_from_fd);
3368 
bpf_tracing_link_release(struct bpf_link * link)3369 static void bpf_tracing_link_release(struct bpf_link *link)
3370 {
3371 	struct bpf_tracing_link *tr_link =
3372 		container_of(link, struct bpf_tracing_link, link.link);
3373 
3374 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3375 						tr_link->trampoline,
3376 						tr_link->tgt_prog));
3377 
3378 	bpf_trampoline_put(tr_link->trampoline);
3379 
3380 	/* tgt_prog is NULL if target is a kernel function */
3381 	if (tr_link->tgt_prog)
3382 		bpf_prog_put(tr_link->tgt_prog);
3383 }
3384 
bpf_tracing_link_dealloc(struct bpf_link * link)3385 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3386 {
3387 	struct bpf_tracing_link *tr_link =
3388 		container_of(link, struct bpf_tracing_link, link.link);
3389 
3390 	kfree(tr_link);
3391 }
3392 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3393 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3394 					 struct seq_file *seq)
3395 {
3396 	struct bpf_tracing_link *tr_link =
3397 		container_of(link, struct bpf_tracing_link, link.link);
3398 	u32 target_btf_id, target_obj_id;
3399 
3400 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3401 				  &target_obj_id, &target_btf_id);
3402 	seq_printf(seq,
3403 		   "attach_type:\t%d\n"
3404 		   "target_obj_id:\t%u\n"
3405 		   "target_btf_id:\t%u\n",
3406 		   tr_link->attach_type,
3407 		   target_obj_id,
3408 		   target_btf_id);
3409 }
3410 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3411 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3412 					   struct bpf_link_info *info)
3413 {
3414 	struct bpf_tracing_link *tr_link =
3415 		container_of(link, struct bpf_tracing_link, link.link);
3416 
3417 	info->tracing.attach_type = tr_link->attach_type;
3418 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3419 				  &info->tracing.target_obj_id,
3420 				  &info->tracing.target_btf_id);
3421 
3422 	return 0;
3423 }
3424 
3425 static const struct bpf_link_ops bpf_tracing_link_lops = {
3426 	.release = bpf_tracing_link_release,
3427 	.dealloc = bpf_tracing_link_dealloc,
3428 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3429 	.fill_link_info = bpf_tracing_link_fill_link_info,
3430 };
3431 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)3432 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3433 				   int tgt_prog_fd,
3434 				   u32 btf_id,
3435 				   u64 bpf_cookie)
3436 {
3437 	struct bpf_link_primer link_primer;
3438 	struct bpf_prog *tgt_prog = NULL;
3439 	struct bpf_trampoline *tr = NULL;
3440 	struct bpf_tracing_link *link;
3441 	u64 key = 0;
3442 	int err;
3443 
3444 	switch (prog->type) {
3445 	case BPF_PROG_TYPE_TRACING:
3446 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3447 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3448 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3449 			err = -EINVAL;
3450 			goto out_put_prog;
3451 		}
3452 		break;
3453 	case BPF_PROG_TYPE_EXT:
3454 		if (prog->expected_attach_type != 0) {
3455 			err = -EINVAL;
3456 			goto out_put_prog;
3457 		}
3458 		break;
3459 	case BPF_PROG_TYPE_LSM:
3460 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3461 			err = -EINVAL;
3462 			goto out_put_prog;
3463 		}
3464 		break;
3465 	default:
3466 		err = -EINVAL;
3467 		goto out_put_prog;
3468 	}
3469 
3470 	if (!!tgt_prog_fd != !!btf_id) {
3471 		err = -EINVAL;
3472 		goto out_put_prog;
3473 	}
3474 
3475 	if (tgt_prog_fd) {
3476 		/*
3477 		 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3478 		 * part would be changed to implement the same for
3479 		 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3480 		 * attach_tracing_prog flag is set.
3481 		 */
3482 		if (prog->type != BPF_PROG_TYPE_EXT) {
3483 			err = -EINVAL;
3484 			goto out_put_prog;
3485 		}
3486 
3487 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3488 		if (IS_ERR(tgt_prog)) {
3489 			err = PTR_ERR(tgt_prog);
3490 			tgt_prog = NULL;
3491 			goto out_put_prog;
3492 		}
3493 
3494 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3495 	}
3496 
3497 	link = kzalloc(sizeof(*link), GFP_USER);
3498 	if (!link) {
3499 		err = -ENOMEM;
3500 		goto out_put_prog;
3501 	}
3502 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3503 		      &bpf_tracing_link_lops, prog);
3504 	link->attach_type = prog->expected_attach_type;
3505 	link->link.cookie = bpf_cookie;
3506 
3507 	mutex_lock(&prog->aux->dst_mutex);
3508 
3509 	/* There are a few possible cases here:
3510 	 *
3511 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3512 	 *   and not yet attached to anything, so we can use the values stored
3513 	 *   in prog->aux
3514 	 *
3515 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3516 	 *   attached to a target and its initial target was cleared (below)
3517 	 *
3518 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3519 	 *   target_btf_id using the link_create API.
3520 	 *
3521 	 * - if tgt_prog == NULL when this function was called using the old
3522 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3523 	 *
3524 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3525 	 *   was detached and is going for re-attachment.
3526 	 *
3527 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3528 	 *   are NULL, then program was already attached and user did not provide
3529 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3530 	 */
3531 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3532 		/*
3533 		 * Allow re-attach for TRACING and LSM programs. If it's
3534 		 * currently linked, bpf_trampoline_link_prog will fail.
3535 		 * EXT programs need to specify tgt_prog_fd, so they
3536 		 * re-attach in separate code path.
3537 		 */
3538 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3539 		    prog->type != BPF_PROG_TYPE_LSM) {
3540 			err = -EINVAL;
3541 			goto out_unlock;
3542 		}
3543 		/* We can allow re-attach only if we have valid attach_btf. */
3544 		if (!prog->aux->attach_btf) {
3545 			err = -EINVAL;
3546 			goto out_unlock;
3547 		}
3548 		btf_id = prog->aux->attach_btf_id;
3549 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3550 	}
3551 
3552 	if (!prog->aux->dst_trampoline ||
3553 	    (key && key != prog->aux->dst_trampoline->key)) {
3554 		/* If there is no saved target, or the specified target is
3555 		 * different from the destination specified at load time, we
3556 		 * need a new trampoline and a check for compatibility
3557 		 */
3558 		struct bpf_attach_target_info tgt_info = {};
3559 
3560 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3561 					      &tgt_info);
3562 		if (err)
3563 			goto out_unlock;
3564 
3565 		if (tgt_info.tgt_mod) {
3566 			module_put(prog->aux->mod);
3567 			prog->aux->mod = tgt_info.tgt_mod;
3568 		}
3569 
3570 		tr = bpf_trampoline_get(key, &tgt_info);
3571 		if (!tr) {
3572 			err = -ENOMEM;
3573 			goto out_unlock;
3574 		}
3575 	} else {
3576 		/* The caller didn't specify a target, or the target was the
3577 		 * same as the destination supplied during program load. This
3578 		 * means we can reuse the trampoline and reference from program
3579 		 * load time, and there is no need to allocate a new one. This
3580 		 * can only happen once for any program, as the saved values in
3581 		 * prog->aux are cleared below.
3582 		 */
3583 		tr = prog->aux->dst_trampoline;
3584 		tgt_prog = prog->aux->dst_prog;
3585 	}
3586 
3587 	err = bpf_link_prime(&link->link.link, &link_primer);
3588 	if (err)
3589 		goto out_unlock;
3590 
3591 	err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3592 	if (err) {
3593 		bpf_link_cleanup(&link_primer);
3594 		link = NULL;
3595 		goto out_unlock;
3596 	}
3597 
3598 	link->tgt_prog = tgt_prog;
3599 	link->trampoline = tr;
3600 
3601 	/* Always clear the trampoline and target prog from prog->aux to make
3602 	 * sure the original attach destination is not kept alive after a
3603 	 * program is (re-)attached to another target.
3604 	 */
3605 	if (prog->aux->dst_prog &&
3606 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3607 		/* got extra prog ref from syscall, or attaching to different prog */
3608 		bpf_prog_put(prog->aux->dst_prog);
3609 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3610 		/* we allocated a new trampoline, so free the old one */
3611 		bpf_trampoline_put(prog->aux->dst_trampoline);
3612 
3613 	prog->aux->dst_prog = NULL;
3614 	prog->aux->dst_trampoline = NULL;
3615 	mutex_unlock(&prog->aux->dst_mutex);
3616 
3617 	return bpf_link_settle(&link_primer);
3618 out_unlock:
3619 	if (tr && tr != prog->aux->dst_trampoline)
3620 		bpf_trampoline_put(tr);
3621 	mutex_unlock(&prog->aux->dst_mutex);
3622 	kfree(link);
3623 out_put_prog:
3624 	if (tgt_prog_fd && tgt_prog)
3625 		bpf_prog_put(tgt_prog);
3626 	return err;
3627 }
3628 
bpf_raw_tp_link_release(struct bpf_link * link)3629 static void bpf_raw_tp_link_release(struct bpf_link *link)
3630 {
3631 	struct bpf_raw_tp_link *raw_tp =
3632 		container_of(link, struct bpf_raw_tp_link, link);
3633 
3634 	bpf_probe_unregister(raw_tp->btp, raw_tp);
3635 	bpf_put_raw_tracepoint(raw_tp->btp);
3636 }
3637 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3638 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3639 {
3640 	struct bpf_raw_tp_link *raw_tp =
3641 		container_of(link, struct bpf_raw_tp_link, link);
3642 
3643 	kfree(raw_tp);
3644 }
3645 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3646 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3647 					struct seq_file *seq)
3648 {
3649 	struct bpf_raw_tp_link *raw_tp_link =
3650 		container_of(link, struct bpf_raw_tp_link, link);
3651 
3652 	seq_printf(seq,
3653 		   "tp_name:\t%s\n",
3654 		   raw_tp_link->btp->tp->name);
3655 }
3656 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3657 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3658 			    u32 len)
3659 {
3660 	if (ulen >= len + 1) {
3661 		if (copy_to_user(ubuf, buf, len + 1))
3662 			return -EFAULT;
3663 	} else {
3664 		char zero = '\0';
3665 
3666 		if (copy_to_user(ubuf, buf, ulen - 1))
3667 			return -EFAULT;
3668 		if (put_user(zero, ubuf + ulen - 1))
3669 			return -EFAULT;
3670 		return -ENOSPC;
3671 	}
3672 
3673 	return 0;
3674 }
3675 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3676 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3677 					  struct bpf_link_info *info)
3678 {
3679 	struct bpf_raw_tp_link *raw_tp_link =
3680 		container_of(link, struct bpf_raw_tp_link, link);
3681 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3682 	const char *tp_name = raw_tp_link->btp->tp->name;
3683 	u32 ulen = info->raw_tracepoint.tp_name_len;
3684 	size_t tp_len = strlen(tp_name);
3685 
3686 	if (!ulen ^ !ubuf)
3687 		return -EINVAL;
3688 
3689 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3690 
3691 	if (!ubuf)
3692 		return 0;
3693 
3694 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3695 }
3696 
3697 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3698 	.release = bpf_raw_tp_link_release,
3699 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3700 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3701 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3702 };
3703 
3704 #ifdef CONFIG_PERF_EVENTS
3705 struct bpf_perf_link {
3706 	struct bpf_link link;
3707 	struct file *perf_file;
3708 };
3709 
bpf_perf_link_release(struct bpf_link * link)3710 static void bpf_perf_link_release(struct bpf_link *link)
3711 {
3712 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3713 	struct perf_event *event = perf_link->perf_file->private_data;
3714 
3715 	perf_event_free_bpf_prog(event);
3716 	fput(perf_link->perf_file);
3717 }
3718 
bpf_perf_link_dealloc(struct bpf_link * link)3719 static void bpf_perf_link_dealloc(struct bpf_link *link)
3720 {
3721 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3722 
3723 	kfree(perf_link);
3724 }
3725 
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)3726 static int bpf_perf_link_fill_common(const struct perf_event *event,
3727 				     char __user *uname, u32 *ulenp,
3728 				     u64 *probe_offset, u64 *probe_addr,
3729 				     u32 *fd_type, unsigned long *missed)
3730 {
3731 	const char *buf;
3732 	u32 prog_id, ulen;
3733 	size_t len;
3734 	int err;
3735 
3736 	ulen = *ulenp;
3737 	if (!ulen ^ !uname)
3738 		return -EINVAL;
3739 
3740 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3741 				      probe_offset, probe_addr, missed);
3742 	if (err)
3743 		return err;
3744 
3745 	if (buf) {
3746 		len = strlen(buf);
3747 		*ulenp = len + 1;
3748 	} else {
3749 		*ulenp = 1;
3750 	}
3751 	if (!uname)
3752 		return 0;
3753 
3754 	if (buf) {
3755 		err = bpf_copy_to_user(uname, buf, ulen, len);
3756 		if (err)
3757 			return err;
3758 	} else {
3759 		char zero = '\0';
3760 
3761 		if (put_user(zero, uname))
3762 			return -EFAULT;
3763 	}
3764 	return 0;
3765 }
3766 
3767 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3768 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3769 				     struct bpf_link_info *info)
3770 {
3771 	unsigned long missed;
3772 	char __user *uname;
3773 	u64 addr, offset;
3774 	u32 ulen, type;
3775 	int err;
3776 
3777 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3778 	ulen = info->perf_event.kprobe.name_len;
3779 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3780 					&type, &missed);
3781 	if (err)
3782 		return err;
3783 	if (type == BPF_FD_TYPE_KRETPROBE)
3784 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3785 	else
3786 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3787 	info->perf_event.kprobe.name_len = ulen;
3788 	info->perf_event.kprobe.offset = offset;
3789 	info->perf_event.kprobe.missed = missed;
3790 	if (!kallsyms_show_value(current_cred()))
3791 		addr = 0;
3792 	info->perf_event.kprobe.addr = addr;
3793 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3794 	return 0;
3795 }
3796 #endif
3797 
3798 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3799 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3800 				     struct bpf_link_info *info)
3801 {
3802 	char __user *uname;
3803 	u64 addr, offset;
3804 	u32 ulen, type;
3805 	int err;
3806 
3807 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3808 	ulen = info->perf_event.uprobe.name_len;
3809 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3810 					&type, NULL);
3811 	if (err)
3812 		return err;
3813 
3814 	if (type == BPF_FD_TYPE_URETPROBE)
3815 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3816 	else
3817 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3818 	info->perf_event.uprobe.name_len = ulen;
3819 	info->perf_event.uprobe.offset = offset;
3820 	info->perf_event.uprobe.cookie = event->bpf_cookie;
3821 	return 0;
3822 }
3823 #endif
3824 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)3825 static int bpf_perf_link_fill_probe(const struct perf_event *event,
3826 				    struct bpf_link_info *info)
3827 {
3828 #ifdef CONFIG_KPROBE_EVENTS
3829 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
3830 		return bpf_perf_link_fill_kprobe(event, info);
3831 #endif
3832 #ifdef CONFIG_UPROBE_EVENTS
3833 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
3834 		return bpf_perf_link_fill_uprobe(event, info);
3835 #endif
3836 	return -EOPNOTSUPP;
3837 }
3838 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)3839 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
3840 					 struct bpf_link_info *info)
3841 {
3842 	char __user *uname;
3843 	u32 ulen;
3844 	int err;
3845 
3846 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
3847 	ulen = info->perf_event.tracepoint.name_len;
3848 	err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
3849 	if (err)
3850 		return err;
3851 
3852 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
3853 	info->perf_event.tracepoint.name_len = ulen;
3854 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
3855 	return 0;
3856 }
3857 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)3858 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
3859 					 struct bpf_link_info *info)
3860 {
3861 	info->perf_event.event.type = event->attr.type;
3862 	info->perf_event.event.config = event->attr.config;
3863 	info->perf_event.event.cookie = event->bpf_cookie;
3864 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
3865 	return 0;
3866 }
3867 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3868 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
3869 					struct bpf_link_info *info)
3870 {
3871 	struct bpf_perf_link *perf_link;
3872 	const struct perf_event *event;
3873 
3874 	perf_link = container_of(link, struct bpf_perf_link, link);
3875 	event = perf_get_event(perf_link->perf_file);
3876 	if (IS_ERR(event))
3877 		return PTR_ERR(event);
3878 
3879 	switch (event->prog->type) {
3880 	case BPF_PROG_TYPE_PERF_EVENT:
3881 		return bpf_perf_link_fill_perf_event(event, info);
3882 	case BPF_PROG_TYPE_TRACEPOINT:
3883 		return bpf_perf_link_fill_tracepoint(event, info);
3884 	case BPF_PROG_TYPE_KPROBE:
3885 		return bpf_perf_link_fill_probe(event, info);
3886 	default:
3887 		return -EOPNOTSUPP;
3888 	}
3889 }
3890 
3891 static const struct bpf_link_ops bpf_perf_link_lops = {
3892 	.release = bpf_perf_link_release,
3893 	.dealloc = bpf_perf_link_dealloc,
3894 	.fill_link_info = bpf_perf_link_fill_link_info,
3895 };
3896 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3897 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3898 {
3899 	struct bpf_link_primer link_primer;
3900 	struct bpf_perf_link *link;
3901 	struct perf_event *event;
3902 	struct file *perf_file;
3903 	int err;
3904 
3905 	if (attr->link_create.flags)
3906 		return -EINVAL;
3907 
3908 	perf_file = perf_event_get(attr->link_create.target_fd);
3909 	if (IS_ERR(perf_file))
3910 		return PTR_ERR(perf_file);
3911 
3912 	link = kzalloc(sizeof(*link), GFP_USER);
3913 	if (!link) {
3914 		err = -ENOMEM;
3915 		goto out_put_file;
3916 	}
3917 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3918 	link->perf_file = perf_file;
3919 
3920 	err = bpf_link_prime(&link->link, &link_primer);
3921 	if (err) {
3922 		kfree(link);
3923 		goto out_put_file;
3924 	}
3925 
3926 	event = perf_file->private_data;
3927 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3928 	if (err) {
3929 		bpf_link_cleanup(&link_primer);
3930 		goto out_put_file;
3931 	}
3932 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3933 	bpf_prog_inc(prog);
3934 
3935 	return bpf_link_settle(&link_primer);
3936 
3937 out_put_file:
3938 	fput(perf_file);
3939 	return err;
3940 }
3941 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3942 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3943 {
3944 	return -EOPNOTSUPP;
3945 }
3946 #endif /* CONFIG_PERF_EVENTS */
3947 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie)3948 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3949 				  const char __user *user_tp_name, u64 cookie)
3950 {
3951 	struct bpf_link_primer link_primer;
3952 	struct bpf_raw_tp_link *link;
3953 	struct bpf_raw_event_map *btp;
3954 	const char *tp_name;
3955 	char buf[128];
3956 	int err;
3957 
3958 	switch (prog->type) {
3959 	case BPF_PROG_TYPE_TRACING:
3960 	case BPF_PROG_TYPE_EXT:
3961 	case BPF_PROG_TYPE_LSM:
3962 		if (user_tp_name)
3963 			/* The attach point for this category of programs
3964 			 * should be specified via btf_id during program load.
3965 			 */
3966 			return -EINVAL;
3967 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3968 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3969 			tp_name = prog->aux->attach_func_name;
3970 			break;
3971 		}
3972 		return bpf_tracing_prog_attach(prog, 0, 0, 0);
3973 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3974 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3975 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3976 			return -EFAULT;
3977 		buf[sizeof(buf) - 1] = 0;
3978 		tp_name = buf;
3979 		break;
3980 	default:
3981 		return -EINVAL;
3982 	}
3983 
3984 	btp = bpf_get_raw_tracepoint(tp_name);
3985 	if (!btp)
3986 		return -ENOENT;
3987 
3988 	link = kzalloc(sizeof(*link), GFP_USER);
3989 	if (!link) {
3990 		err = -ENOMEM;
3991 		goto out_put_btp;
3992 	}
3993 	bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3994 				&bpf_raw_tp_link_lops, prog,
3995 				tracepoint_is_faultable(btp->tp));
3996 	link->btp = btp;
3997 	link->cookie = cookie;
3998 
3999 	err = bpf_link_prime(&link->link, &link_primer);
4000 	if (err) {
4001 		kfree(link);
4002 		goto out_put_btp;
4003 	}
4004 
4005 	err = bpf_probe_register(link->btp, link);
4006 	if (err) {
4007 		bpf_link_cleanup(&link_primer);
4008 		goto out_put_btp;
4009 	}
4010 
4011 	return bpf_link_settle(&link_primer);
4012 
4013 out_put_btp:
4014 	bpf_put_raw_tracepoint(btp);
4015 	return err;
4016 }
4017 
4018 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4019 
bpf_raw_tracepoint_open(const union bpf_attr * attr)4020 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4021 {
4022 	struct bpf_prog *prog;
4023 	void __user *tp_name;
4024 	__u64 cookie;
4025 	int fd;
4026 
4027 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4028 		return -EINVAL;
4029 
4030 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4031 	if (IS_ERR(prog))
4032 		return PTR_ERR(prog);
4033 
4034 	tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4035 	cookie = attr->raw_tracepoint.cookie;
4036 	fd = bpf_raw_tp_link_attach(prog, tp_name, cookie);
4037 	if (fd < 0)
4038 		bpf_prog_put(prog);
4039 	return fd;
4040 }
4041 
4042 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4043 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4044 {
4045 	switch (attach_type) {
4046 	case BPF_CGROUP_INET_INGRESS:
4047 	case BPF_CGROUP_INET_EGRESS:
4048 		return BPF_PROG_TYPE_CGROUP_SKB;
4049 	case BPF_CGROUP_INET_SOCK_CREATE:
4050 	case BPF_CGROUP_INET_SOCK_RELEASE:
4051 	case BPF_CGROUP_INET4_POST_BIND:
4052 	case BPF_CGROUP_INET6_POST_BIND:
4053 		return BPF_PROG_TYPE_CGROUP_SOCK;
4054 	case BPF_CGROUP_INET4_BIND:
4055 	case BPF_CGROUP_INET6_BIND:
4056 	case BPF_CGROUP_INET4_CONNECT:
4057 	case BPF_CGROUP_INET6_CONNECT:
4058 	case BPF_CGROUP_UNIX_CONNECT:
4059 	case BPF_CGROUP_INET4_GETPEERNAME:
4060 	case BPF_CGROUP_INET6_GETPEERNAME:
4061 	case BPF_CGROUP_UNIX_GETPEERNAME:
4062 	case BPF_CGROUP_INET4_GETSOCKNAME:
4063 	case BPF_CGROUP_INET6_GETSOCKNAME:
4064 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4065 	case BPF_CGROUP_UDP4_SENDMSG:
4066 	case BPF_CGROUP_UDP6_SENDMSG:
4067 	case BPF_CGROUP_UNIX_SENDMSG:
4068 	case BPF_CGROUP_UDP4_RECVMSG:
4069 	case BPF_CGROUP_UDP6_RECVMSG:
4070 	case BPF_CGROUP_UNIX_RECVMSG:
4071 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4072 	case BPF_CGROUP_SOCK_OPS:
4073 		return BPF_PROG_TYPE_SOCK_OPS;
4074 	case BPF_CGROUP_DEVICE:
4075 		return BPF_PROG_TYPE_CGROUP_DEVICE;
4076 	case BPF_SK_MSG_VERDICT:
4077 		return BPF_PROG_TYPE_SK_MSG;
4078 	case BPF_SK_SKB_STREAM_PARSER:
4079 	case BPF_SK_SKB_STREAM_VERDICT:
4080 	case BPF_SK_SKB_VERDICT:
4081 		return BPF_PROG_TYPE_SK_SKB;
4082 	case BPF_LIRC_MODE2:
4083 		return BPF_PROG_TYPE_LIRC_MODE2;
4084 	case BPF_FLOW_DISSECTOR:
4085 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
4086 	case BPF_CGROUP_SYSCTL:
4087 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
4088 	case BPF_CGROUP_GETSOCKOPT:
4089 	case BPF_CGROUP_SETSOCKOPT:
4090 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4091 	case BPF_TRACE_ITER:
4092 	case BPF_TRACE_RAW_TP:
4093 	case BPF_TRACE_FENTRY:
4094 	case BPF_TRACE_FEXIT:
4095 	case BPF_MODIFY_RETURN:
4096 		return BPF_PROG_TYPE_TRACING;
4097 	case BPF_LSM_MAC:
4098 		return BPF_PROG_TYPE_LSM;
4099 	case BPF_SK_LOOKUP:
4100 		return BPF_PROG_TYPE_SK_LOOKUP;
4101 	case BPF_XDP:
4102 		return BPF_PROG_TYPE_XDP;
4103 	case BPF_LSM_CGROUP:
4104 		return BPF_PROG_TYPE_LSM;
4105 	case BPF_TCX_INGRESS:
4106 	case BPF_TCX_EGRESS:
4107 	case BPF_NETKIT_PRIMARY:
4108 	case BPF_NETKIT_PEER:
4109 		return BPF_PROG_TYPE_SCHED_CLS;
4110 	default:
4111 		return BPF_PROG_TYPE_UNSPEC;
4112 	}
4113 }
4114 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4115 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4116 					     enum bpf_attach_type attach_type)
4117 {
4118 	enum bpf_prog_type ptype;
4119 
4120 	switch (prog->type) {
4121 	case BPF_PROG_TYPE_CGROUP_SOCK:
4122 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4123 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4124 	case BPF_PROG_TYPE_SK_LOOKUP:
4125 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4126 	case BPF_PROG_TYPE_CGROUP_SKB:
4127 		if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4128 			/* cg-skb progs can be loaded by unpriv user.
4129 			 * check permissions at attach time.
4130 			 */
4131 			return -EPERM;
4132 
4133 		ptype = attach_type_to_prog_type(attach_type);
4134 		if (prog->type != ptype)
4135 			return -EINVAL;
4136 
4137 		return prog->enforce_expected_attach_type &&
4138 			prog->expected_attach_type != attach_type ?
4139 			-EINVAL : 0;
4140 	case BPF_PROG_TYPE_EXT:
4141 		return 0;
4142 	case BPF_PROG_TYPE_NETFILTER:
4143 		if (attach_type != BPF_NETFILTER)
4144 			return -EINVAL;
4145 		return 0;
4146 	case BPF_PROG_TYPE_PERF_EVENT:
4147 	case BPF_PROG_TYPE_TRACEPOINT:
4148 		if (attach_type != BPF_PERF_EVENT)
4149 			return -EINVAL;
4150 		return 0;
4151 	case BPF_PROG_TYPE_KPROBE:
4152 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4153 		    attach_type != BPF_TRACE_KPROBE_MULTI)
4154 			return -EINVAL;
4155 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4156 		    attach_type != BPF_TRACE_KPROBE_SESSION)
4157 			return -EINVAL;
4158 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4159 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4160 			return -EINVAL;
4161 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4162 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4163 			return -EINVAL;
4164 		if (attach_type != BPF_PERF_EVENT &&
4165 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
4166 		    attach_type != BPF_TRACE_KPROBE_SESSION &&
4167 		    attach_type != BPF_TRACE_UPROBE_MULTI &&
4168 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4169 			return -EINVAL;
4170 		return 0;
4171 	case BPF_PROG_TYPE_SCHED_CLS:
4172 		if (attach_type != BPF_TCX_INGRESS &&
4173 		    attach_type != BPF_TCX_EGRESS &&
4174 		    attach_type != BPF_NETKIT_PRIMARY &&
4175 		    attach_type != BPF_NETKIT_PEER)
4176 			return -EINVAL;
4177 		return 0;
4178 	default:
4179 		ptype = attach_type_to_prog_type(attach_type);
4180 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4181 			return -EINVAL;
4182 		return 0;
4183 	}
4184 }
4185 
4186 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4187 
4188 #define BPF_F_ATTACH_MASK_BASE	\
4189 	(BPF_F_ALLOW_OVERRIDE |	\
4190 	 BPF_F_ALLOW_MULTI |	\
4191 	 BPF_F_REPLACE |	\
4192 	 BPF_F_PREORDER)
4193 
4194 #define BPF_F_ATTACH_MASK_MPROG	\
4195 	(BPF_F_REPLACE |	\
4196 	 BPF_F_BEFORE |		\
4197 	 BPF_F_AFTER |		\
4198 	 BPF_F_ID |		\
4199 	 BPF_F_LINK)
4200 
bpf_prog_attach(const union bpf_attr * attr)4201 static int bpf_prog_attach(const union bpf_attr *attr)
4202 {
4203 	enum bpf_prog_type ptype;
4204 	struct bpf_prog *prog;
4205 	int ret;
4206 
4207 	if (CHECK_ATTR(BPF_PROG_ATTACH))
4208 		return -EINVAL;
4209 
4210 	ptype = attach_type_to_prog_type(attr->attach_type);
4211 	if (ptype == BPF_PROG_TYPE_UNSPEC)
4212 		return -EINVAL;
4213 	if (bpf_mprog_supported(ptype)) {
4214 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4215 			return -EINVAL;
4216 	} else {
4217 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4218 			return -EINVAL;
4219 		if (attr->relative_fd ||
4220 		    attr->expected_revision)
4221 			return -EINVAL;
4222 	}
4223 
4224 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4225 	if (IS_ERR(prog))
4226 		return PTR_ERR(prog);
4227 
4228 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4229 		bpf_prog_put(prog);
4230 		return -EINVAL;
4231 	}
4232 
4233 	switch (ptype) {
4234 	case BPF_PROG_TYPE_SK_SKB:
4235 	case BPF_PROG_TYPE_SK_MSG:
4236 		ret = sock_map_get_from_fd(attr, prog);
4237 		break;
4238 	case BPF_PROG_TYPE_LIRC_MODE2:
4239 		ret = lirc_prog_attach(attr, prog);
4240 		break;
4241 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4242 		ret = netns_bpf_prog_attach(attr, prog);
4243 		break;
4244 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4245 	case BPF_PROG_TYPE_CGROUP_SKB:
4246 	case BPF_PROG_TYPE_CGROUP_SOCK:
4247 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4248 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4249 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4250 	case BPF_PROG_TYPE_SOCK_OPS:
4251 	case BPF_PROG_TYPE_LSM:
4252 		if (ptype == BPF_PROG_TYPE_LSM &&
4253 		    prog->expected_attach_type != BPF_LSM_CGROUP)
4254 			ret = -EINVAL;
4255 		else
4256 			ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4257 		break;
4258 	case BPF_PROG_TYPE_SCHED_CLS:
4259 		if (attr->attach_type == BPF_TCX_INGRESS ||
4260 		    attr->attach_type == BPF_TCX_EGRESS)
4261 			ret = tcx_prog_attach(attr, prog);
4262 		else
4263 			ret = netkit_prog_attach(attr, prog);
4264 		break;
4265 	default:
4266 		ret = -EINVAL;
4267 	}
4268 
4269 	if (ret)
4270 		bpf_prog_put(prog);
4271 	return ret;
4272 }
4273 
4274 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4275 
bpf_prog_detach(const union bpf_attr * attr)4276 static int bpf_prog_detach(const union bpf_attr *attr)
4277 {
4278 	struct bpf_prog *prog = NULL;
4279 	enum bpf_prog_type ptype;
4280 	int ret;
4281 
4282 	if (CHECK_ATTR(BPF_PROG_DETACH))
4283 		return -EINVAL;
4284 
4285 	ptype = attach_type_to_prog_type(attr->attach_type);
4286 	if (bpf_mprog_supported(ptype)) {
4287 		if (ptype == BPF_PROG_TYPE_UNSPEC)
4288 			return -EINVAL;
4289 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4290 			return -EINVAL;
4291 		if (attr->attach_bpf_fd) {
4292 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4293 			if (IS_ERR(prog))
4294 				return PTR_ERR(prog);
4295 		}
4296 	} else if (attr->attach_flags ||
4297 		   attr->relative_fd ||
4298 		   attr->expected_revision) {
4299 		return -EINVAL;
4300 	}
4301 
4302 	switch (ptype) {
4303 	case BPF_PROG_TYPE_SK_MSG:
4304 	case BPF_PROG_TYPE_SK_SKB:
4305 		ret = sock_map_prog_detach(attr, ptype);
4306 		break;
4307 	case BPF_PROG_TYPE_LIRC_MODE2:
4308 		ret = lirc_prog_detach(attr);
4309 		break;
4310 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4311 		ret = netns_bpf_prog_detach(attr, ptype);
4312 		break;
4313 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4314 	case BPF_PROG_TYPE_CGROUP_SKB:
4315 	case BPF_PROG_TYPE_CGROUP_SOCK:
4316 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4317 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4318 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4319 	case BPF_PROG_TYPE_SOCK_OPS:
4320 	case BPF_PROG_TYPE_LSM:
4321 		ret = cgroup_bpf_prog_detach(attr, ptype);
4322 		break;
4323 	case BPF_PROG_TYPE_SCHED_CLS:
4324 		if (attr->attach_type == BPF_TCX_INGRESS ||
4325 		    attr->attach_type == BPF_TCX_EGRESS)
4326 			ret = tcx_prog_detach(attr, prog);
4327 		else
4328 			ret = netkit_prog_detach(attr, prog);
4329 		break;
4330 	default:
4331 		ret = -EINVAL;
4332 	}
4333 
4334 	if (prog)
4335 		bpf_prog_put(prog);
4336 	return ret;
4337 }
4338 
4339 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4340 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4341 static int bpf_prog_query(const union bpf_attr *attr,
4342 			  union bpf_attr __user *uattr)
4343 {
4344 	if (!bpf_net_capable())
4345 		return -EPERM;
4346 	if (CHECK_ATTR(BPF_PROG_QUERY))
4347 		return -EINVAL;
4348 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4349 		return -EINVAL;
4350 
4351 	switch (attr->query.attach_type) {
4352 	case BPF_CGROUP_INET_INGRESS:
4353 	case BPF_CGROUP_INET_EGRESS:
4354 	case BPF_CGROUP_INET_SOCK_CREATE:
4355 	case BPF_CGROUP_INET_SOCK_RELEASE:
4356 	case BPF_CGROUP_INET4_BIND:
4357 	case BPF_CGROUP_INET6_BIND:
4358 	case BPF_CGROUP_INET4_POST_BIND:
4359 	case BPF_CGROUP_INET6_POST_BIND:
4360 	case BPF_CGROUP_INET4_CONNECT:
4361 	case BPF_CGROUP_INET6_CONNECT:
4362 	case BPF_CGROUP_UNIX_CONNECT:
4363 	case BPF_CGROUP_INET4_GETPEERNAME:
4364 	case BPF_CGROUP_INET6_GETPEERNAME:
4365 	case BPF_CGROUP_UNIX_GETPEERNAME:
4366 	case BPF_CGROUP_INET4_GETSOCKNAME:
4367 	case BPF_CGROUP_INET6_GETSOCKNAME:
4368 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4369 	case BPF_CGROUP_UDP4_SENDMSG:
4370 	case BPF_CGROUP_UDP6_SENDMSG:
4371 	case BPF_CGROUP_UNIX_SENDMSG:
4372 	case BPF_CGROUP_UDP4_RECVMSG:
4373 	case BPF_CGROUP_UDP6_RECVMSG:
4374 	case BPF_CGROUP_UNIX_RECVMSG:
4375 	case BPF_CGROUP_SOCK_OPS:
4376 	case BPF_CGROUP_DEVICE:
4377 	case BPF_CGROUP_SYSCTL:
4378 	case BPF_CGROUP_GETSOCKOPT:
4379 	case BPF_CGROUP_SETSOCKOPT:
4380 	case BPF_LSM_CGROUP:
4381 		return cgroup_bpf_prog_query(attr, uattr);
4382 	case BPF_LIRC_MODE2:
4383 		return lirc_prog_query(attr, uattr);
4384 	case BPF_FLOW_DISSECTOR:
4385 	case BPF_SK_LOOKUP:
4386 		return netns_bpf_prog_query(attr, uattr);
4387 	case BPF_SK_SKB_STREAM_PARSER:
4388 	case BPF_SK_SKB_STREAM_VERDICT:
4389 	case BPF_SK_MSG_VERDICT:
4390 	case BPF_SK_SKB_VERDICT:
4391 		return sock_map_bpf_prog_query(attr, uattr);
4392 	case BPF_TCX_INGRESS:
4393 	case BPF_TCX_EGRESS:
4394 		return tcx_prog_query(attr, uattr);
4395 	case BPF_NETKIT_PRIMARY:
4396 	case BPF_NETKIT_PEER:
4397 		return netkit_prog_query(attr, uattr);
4398 	default:
4399 		return -EINVAL;
4400 	}
4401 }
4402 
4403 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4404 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4405 static int bpf_prog_test_run(const union bpf_attr *attr,
4406 			     union bpf_attr __user *uattr)
4407 {
4408 	struct bpf_prog *prog;
4409 	int ret = -ENOTSUPP;
4410 
4411 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4412 		return -EINVAL;
4413 
4414 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4415 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4416 		return -EINVAL;
4417 
4418 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4419 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4420 		return -EINVAL;
4421 
4422 	prog = bpf_prog_get(attr->test.prog_fd);
4423 	if (IS_ERR(prog))
4424 		return PTR_ERR(prog);
4425 
4426 	if (prog->aux->ops->test_run)
4427 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4428 
4429 	bpf_prog_put(prog);
4430 	return ret;
4431 }
4432 
4433 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4434 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4435 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4436 			       union bpf_attr __user *uattr,
4437 			       struct idr *idr,
4438 			       spinlock_t *lock)
4439 {
4440 	u32 next_id = attr->start_id;
4441 	int err = 0;
4442 
4443 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4444 		return -EINVAL;
4445 
4446 	if (!capable(CAP_SYS_ADMIN))
4447 		return -EPERM;
4448 
4449 	next_id++;
4450 	spin_lock_bh(lock);
4451 	if (!idr_get_next(idr, &next_id))
4452 		err = -ENOENT;
4453 	spin_unlock_bh(lock);
4454 
4455 	if (!err)
4456 		err = put_user(next_id, &uattr->next_id);
4457 
4458 	return err;
4459 }
4460 
bpf_map_get_curr_or_next(u32 * id)4461 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4462 {
4463 	struct bpf_map *map;
4464 
4465 	spin_lock_bh(&map_idr_lock);
4466 again:
4467 	map = idr_get_next(&map_idr, id);
4468 	if (map) {
4469 		map = __bpf_map_inc_not_zero(map, false);
4470 		if (IS_ERR(map)) {
4471 			(*id)++;
4472 			goto again;
4473 		}
4474 	}
4475 	spin_unlock_bh(&map_idr_lock);
4476 
4477 	return map;
4478 }
4479 
bpf_prog_get_curr_or_next(u32 * id)4480 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4481 {
4482 	struct bpf_prog *prog;
4483 
4484 	spin_lock_bh(&prog_idr_lock);
4485 again:
4486 	prog = idr_get_next(&prog_idr, id);
4487 	if (prog) {
4488 		prog = bpf_prog_inc_not_zero(prog);
4489 		if (IS_ERR(prog)) {
4490 			(*id)++;
4491 			goto again;
4492 		}
4493 	}
4494 	spin_unlock_bh(&prog_idr_lock);
4495 
4496 	return prog;
4497 }
4498 
4499 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4500 
bpf_prog_by_id(u32 id)4501 struct bpf_prog *bpf_prog_by_id(u32 id)
4502 {
4503 	struct bpf_prog *prog;
4504 
4505 	if (!id)
4506 		return ERR_PTR(-ENOENT);
4507 
4508 	spin_lock_bh(&prog_idr_lock);
4509 	prog = idr_find(&prog_idr, id);
4510 	if (prog)
4511 		prog = bpf_prog_inc_not_zero(prog);
4512 	else
4513 		prog = ERR_PTR(-ENOENT);
4514 	spin_unlock_bh(&prog_idr_lock);
4515 	return prog;
4516 }
4517 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4518 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4519 {
4520 	struct bpf_prog *prog;
4521 	u32 id = attr->prog_id;
4522 	int fd;
4523 
4524 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4525 		return -EINVAL;
4526 
4527 	if (!capable(CAP_SYS_ADMIN))
4528 		return -EPERM;
4529 
4530 	prog = bpf_prog_by_id(id);
4531 	if (IS_ERR(prog))
4532 		return PTR_ERR(prog);
4533 
4534 	fd = bpf_prog_new_fd(prog);
4535 	if (fd < 0)
4536 		bpf_prog_put(prog);
4537 
4538 	return fd;
4539 }
4540 
4541 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4542 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4543 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4544 {
4545 	struct bpf_map *map;
4546 	u32 id = attr->map_id;
4547 	int f_flags;
4548 	int fd;
4549 
4550 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4551 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4552 		return -EINVAL;
4553 
4554 	if (!capable(CAP_SYS_ADMIN))
4555 		return -EPERM;
4556 
4557 	f_flags = bpf_get_file_flag(attr->open_flags);
4558 	if (f_flags < 0)
4559 		return f_flags;
4560 
4561 	spin_lock_bh(&map_idr_lock);
4562 	map = idr_find(&map_idr, id);
4563 	if (map)
4564 		map = __bpf_map_inc_not_zero(map, true);
4565 	else
4566 		map = ERR_PTR(-ENOENT);
4567 	spin_unlock_bh(&map_idr_lock);
4568 
4569 	if (IS_ERR(map))
4570 		return PTR_ERR(map);
4571 
4572 	fd = bpf_map_new_fd(map, f_flags);
4573 	if (fd < 0)
4574 		bpf_map_put_with_uref(map);
4575 
4576 	return fd;
4577 }
4578 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4579 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4580 					      unsigned long addr, u32 *off,
4581 					      u32 *type)
4582 {
4583 	const struct bpf_map *map;
4584 	int i;
4585 
4586 	mutex_lock(&prog->aux->used_maps_mutex);
4587 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4588 		map = prog->aux->used_maps[i];
4589 		if (map == (void *)addr) {
4590 			*type = BPF_PSEUDO_MAP_FD;
4591 			goto out;
4592 		}
4593 		if (!map->ops->map_direct_value_meta)
4594 			continue;
4595 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4596 			*type = BPF_PSEUDO_MAP_VALUE;
4597 			goto out;
4598 		}
4599 	}
4600 	map = NULL;
4601 
4602 out:
4603 	mutex_unlock(&prog->aux->used_maps_mutex);
4604 	return map;
4605 }
4606 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4607 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4608 					      const struct cred *f_cred)
4609 {
4610 	const struct bpf_map *map;
4611 	struct bpf_insn *insns;
4612 	u32 off, type;
4613 	u64 imm;
4614 	u8 code;
4615 	int i;
4616 
4617 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4618 			GFP_USER);
4619 	if (!insns)
4620 		return insns;
4621 
4622 	for (i = 0; i < prog->len; i++) {
4623 		code = insns[i].code;
4624 
4625 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4626 			insns[i].code = BPF_JMP | BPF_CALL;
4627 			insns[i].imm = BPF_FUNC_tail_call;
4628 			/* fall-through */
4629 		}
4630 		if (code == (BPF_JMP | BPF_CALL) ||
4631 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4632 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4633 				insns[i].code = BPF_JMP | BPF_CALL;
4634 			if (!bpf_dump_raw_ok(f_cred))
4635 				insns[i].imm = 0;
4636 			continue;
4637 		}
4638 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4639 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4640 			continue;
4641 		}
4642 
4643 		if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4644 		     BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4645 			insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4646 			continue;
4647 		}
4648 
4649 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4650 			continue;
4651 
4652 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4653 		map = bpf_map_from_imm(prog, imm, &off, &type);
4654 		if (map) {
4655 			insns[i].src_reg = type;
4656 			insns[i].imm = map->id;
4657 			insns[i + 1].imm = off;
4658 			continue;
4659 		}
4660 	}
4661 
4662 	return insns;
4663 }
4664 
set_info_rec_size(struct bpf_prog_info * info)4665 static int set_info_rec_size(struct bpf_prog_info *info)
4666 {
4667 	/*
4668 	 * Ensure info.*_rec_size is the same as kernel expected size
4669 	 *
4670 	 * or
4671 	 *
4672 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4673 	 * zero.  In this case, the kernel will set the expected
4674 	 * _rec_size back to the info.
4675 	 */
4676 
4677 	if ((info->nr_func_info || info->func_info_rec_size) &&
4678 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4679 		return -EINVAL;
4680 
4681 	if ((info->nr_line_info || info->line_info_rec_size) &&
4682 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
4683 		return -EINVAL;
4684 
4685 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4686 	    info->jited_line_info_rec_size != sizeof(__u64))
4687 		return -EINVAL;
4688 
4689 	info->func_info_rec_size = sizeof(struct bpf_func_info);
4690 	info->line_info_rec_size = sizeof(struct bpf_line_info);
4691 	info->jited_line_info_rec_size = sizeof(__u64);
4692 
4693 	return 0;
4694 }
4695 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4696 static int bpf_prog_get_info_by_fd(struct file *file,
4697 				   struct bpf_prog *prog,
4698 				   const union bpf_attr *attr,
4699 				   union bpf_attr __user *uattr)
4700 {
4701 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4702 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4703 	struct bpf_prog_info info;
4704 	u32 info_len = attr->info.info_len;
4705 	struct bpf_prog_kstats stats;
4706 	char __user *uinsns;
4707 	u32 ulen;
4708 	int err;
4709 
4710 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4711 	if (err)
4712 		return err;
4713 	info_len = min_t(u32, sizeof(info), info_len);
4714 
4715 	memset(&info, 0, sizeof(info));
4716 	if (copy_from_user(&info, uinfo, info_len))
4717 		return -EFAULT;
4718 
4719 	info.type = prog->type;
4720 	info.id = prog->aux->id;
4721 	info.load_time = prog->aux->load_time;
4722 	info.created_by_uid = from_kuid_munged(current_user_ns(),
4723 					       prog->aux->user->uid);
4724 	info.gpl_compatible = prog->gpl_compatible;
4725 
4726 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
4727 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
4728 
4729 	mutex_lock(&prog->aux->used_maps_mutex);
4730 	ulen = info.nr_map_ids;
4731 	info.nr_map_ids = prog->aux->used_map_cnt;
4732 	ulen = min_t(u32, info.nr_map_ids, ulen);
4733 	if (ulen) {
4734 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
4735 		u32 i;
4736 
4737 		for (i = 0; i < ulen; i++)
4738 			if (put_user(prog->aux->used_maps[i]->id,
4739 				     &user_map_ids[i])) {
4740 				mutex_unlock(&prog->aux->used_maps_mutex);
4741 				return -EFAULT;
4742 			}
4743 	}
4744 	mutex_unlock(&prog->aux->used_maps_mutex);
4745 
4746 	err = set_info_rec_size(&info);
4747 	if (err)
4748 		return err;
4749 
4750 	bpf_prog_get_stats(prog, &stats);
4751 	info.run_time_ns = stats.nsecs;
4752 	info.run_cnt = stats.cnt;
4753 	info.recursion_misses = stats.misses;
4754 
4755 	info.verified_insns = prog->aux->verified_insns;
4756 	if (prog->aux->btf)
4757 		info.btf_id = btf_obj_id(prog->aux->btf);
4758 
4759 	if (!bpf_capable()) {
4760 		info.jited_prog_len = 0;
4761 		info.xlated_prog_len = 0;
4762 		info.nr_jited_ksyms = 0;
4763 		info.nr_jited_func_lens = 0;
4764 		info.nr_func_info = 0;
4765 		info.nr_line_info = 0;
4766 		info.nr_jited_line_info = 0;
4767 		goto done;
4768 	}
4769 
4770 	ulen = info.xlated_prog_len;
4771 	info.xlated_prog_len = bpf_prog_insn_size(prog);
4772 	if (info.xlated_prog_len && ulen) {
4773 		struct bpf_insn *insns_sanitized;
4774 		bool fault;
4775 
4776 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
4777 			info.xlated_prog_insns = 0;
4778 			goto done;
4779 		}
4780 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
4781 		if (!insns_sanitized)
4782 			return -ENOMEM;
4783 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
4784 		ulen = min_t(u32, info.xlated_prog_len, ulen);
4785 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
4786 		kfree(insns_sanitized);
4787 		if (fault)
4788 			return -EFAULT;
4789 	}
4790 
4791 	if (bpf_prog_is_offloaded(prog->aux)) {
4792 		err = bpf_prog_offload_info_fill(&info, prog);
4793 		if (err)
4794 			return err;
4795 		goto done;
4796 	}
4797 
4798 	/* NOTE: the following code is supposed to be skipped for offload.
4799 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
4800 	 * for offload.
4801 	 */
4802 	ulen = info.jited_prog_len;
4803 	if (prog->aux->func_cnt) {
4804 		u32 i;
4805 
4806 		info.jited_prog_len = 0;
4807 		for (i = 0; i < prog->aux->func_cnt; i++)
4808 			info.jited_prog_len += prog->aux->func[i]->jited_len;
4809 	} else {
4810 		info.jited_prog_len = prog->jited_len;
4811 	}
4812 
4813 	if (info.jited_prog_len && ulen) {
4814 		if (bpf_dump_raw_ok(file->f_cred)) {
4815 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
4816 			ulen = min_t(u32, info.jited_prog_len, ulen);
4817 
4818 			/* for multi-function programs, copy the JITed
4819 			 * instructions for all the functions
4820 			 */
4821 			if (prog->aux->func_cnt) {
4822 				u32 len, free, i;
4823 				u8 *img;
4824 
4825 				free = ulen;
4826 				for (i = 0; i < prog->aux->func_cnt; i++) {
4827 					len = prog->aux->func[i]->jited_len;
4828 					len = min_t(u32, len, free);
4829 					img = (u8 *) prog->aux->func[i]->bpf_func;
4830 					if (copy_to_user(uinsns, img, len))
4831 						return -EFAULT;
4832 					uinsns += len;
4833 					free -= len;
4834 					if (!free)
4835 						break;
4836 				}
4837 			} else {
4838 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
4839 					return -EFAULT;
4840 			}
4841 		} else {
4842 			info.jited_prog_insns = 0;
4843 		}
4844 	}
4845 
4846 	ulen = info.nr_jited_ksyms;
4847 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4848 	if (ulen) {
4849 		if (bpf_dump_raw_ok(file->f_cred)) {
4850 			unsigned long ksym_addr;
4851 			u64 __user *user_ksyms;
4852 			u32 i;
4853 
4854 			/* copy the address of the kernel symbol
4855 			 * corresponding to each function
4856 			 */
4857 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4858 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4859 			if (prog->aux->func_cnt) {
4860 				for (i = 0; i < ulen; i++) {
4861 					ksym_addr = (unsigned long)
4862 						prog->aux->func[i]->bpf_func;
4863 					if (put_user((u64) ksym_addr,
4864 						     &user_ksyms[i]))
4865 						return -EFAULT;
4866 				}
4867 			} else {
4868 				ksym_addr = (unsigned long) prog->bpf_func;
4869 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
4870 					return -EFAULT;
4871 			}
4872 		} else {
4873 			info.jited_ksyms = 0;
4874 		}
4875 	}
4876 
4877 	ulen = info.nr_jited_func_lens;
4878 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4879 	if (ulen) {
4880 		if (bpf_dump_raw_ok(file->f_cred)) {
4881 			u32 __user *user_lens;
4882 			u32 func_len, i;
4883 
4884 			/* copy the JITed image lengths for each function */
4885 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4886 			user_lens = u64_to_user_ptr(info.jited_func_lens);
4887 			if (prog->aux->func_cnt) {
4888 				for (i = 0; i < ulen; i++) {
4889 					func_len =
4890 						prog->aux->func[i]->jited_len;
4891 					if (put_user(func_len, &user_lens[i]))
4892 						return -EFAULT;
4893 				}
4894 			} else {
4895 				func_len = prog->jited_len;
4896 				if (put_user(func_len, &user_lens[0]))
4897 					return -EFAULT;
4898 			}
4899 		} else {
4900 			info.jited_func_lens = 0;
4901 		}
4902 	}
4903 
4904 	info.attach_btf_id = prog->aux->attach_btf_id;
4905 	if (attach_btf)
4906 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
4907 
4908 	ulen = info.nr_func_info;
4909 	info.nr_func_info = prog->aux->func_info_cnt;
4910 	if (info.nr_func_info && ulen) {
4911 		char __user *user_finfo;
4912 
4913 		user_finfo = u64_to_user_ptr(info.func_info);
4914 		ulen = min_t(u32, info.nr_func_info, ulen);
4915 		if (copy_to_user(user_finfo, prog->aux->func_info,
4916 				 info.func_info_rec_size * ulen))
4917 			return -EFAULT;
4918 	}
4919 
4920 	ulen = info.nr_line_info;
4921 	info.nr_line_info = prog->aux->nr_linfo;
4922 	if (info.nr_line_info && ulen) {
4923 		__u8 __user *user_linfo;
4924 
4925 		user_linfo = u64_to_user_ptr(info.line_info);
4926 		ulen = min_t(u32, info.nr_line_info, ulen);
4927 		if (copy_to_user(user_linfo, prog->aux->linfo,
4928 				 info.line_info_rec_size * ulen))
4929 			return -EFAULT;
4930 	}
4931 
4932 	ulen = info.nr_jited_line_info;
4933 	if (prog->aux->jited_linfo)
4934 		info.nr_jited_line_info = prog->aux->nr_linfo;
4935 	else
4936 		info.nr_jited_line_info = 0;
4937 	if (info.nr_jited_line_info && ulen) {
4938 		if (bpf_dump_raw_ok(file->f_cred)) {
4939 			unsigned long line_addr;
4940 			__u64 __user *user_linfo;
4941 			u32 i;
4942 
4943 			user_linfo = u64_to_user_ptr(info.jited_line_info);
4944 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
4945 			for (i = 0; i < ulen; i++) {
4946 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
4947 				if (put_user((__u64)line_addr, &user_linfo[i]))
4948 					return -EFAULT;
4949 			}
4950 		} else {
4951 			info.jited_line_info = 0;
4952 		}
4953 	}
4954 
4955 	ulen = info.nr_prog_tags;
4956 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4957 	if (ulen) {
4958 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4959 		u32 i;
4960 
4961 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
4962 		ulen = min_t(u32, info.nr_prog_tags, ulen);
4963 		if (prog->aux->func_cnt) {
4964 			for (i = 0; i < ulen; i++) {
4965 				if (copy_to_user(user_prog_tags[i],
4966 						 prog->aux->func[i]->tag,
4967 						 BPF_TAG_SIZE))
4968 					return -EFAULT;
4969 			}
4970 		} else {
4971 			if (copy_to_user(user_prog_tags[0],
4972 					 prog->tag, BPF_TAG_SIZE))
4973 				return -EFAULT;
4974 		}
4975 	}
4976 
4977 done:
4978 	if (copy_to_user(uinfo, &info, info_len) ||
4979 	    put_user(info_len, &uattr->info.info_len))
4980 		return -EFAULT;
4981 
4982 	return 0;
4983 }
4984 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4985 static int bpf_map_get_info_by_fd(struct file *file,
4986 				  struct bpf_map *map,
4987 				  const union bpf_attr *attr,
4988 				  union bpf_attr __user *uattr)
4989 {
4990 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4991 	struct bpf_map_info info;
4992 	u32 info_len = attr->info.info_len;
4993 	int err;
4994 
4995 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4996 	if (err)
4997 		return err;
4998 	info_len = min_t(u32, sizeof(info), info_len);
4999 
5000 	memset(&info, 0, sizeof(info));
5001 	info.type = map->map_type;
5002 	info.id = map->id;
5003 	info.key_size = map->key_size;
5004 	info.value_size = map->value_size;
5005 	info.max_entries = map->max_entries;
5006 	info.map_flags = map->map_flags;
5007 	info.map_extra = map->map_extra;
5008 	memcpy(info.name, map->name, sizeof(map->name));
5009 
5010 	if (map->btf) {
5011 		info.btf_id = btf_obj_id(map->btf);
5012 		info.btf_key_type_id = map->btf_key_type_id;
5013 		info.btf_value_type_id = map->btf_value_type_id;
5014 	}
5015 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5016 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5017 		bpf_map_struct_ops_info_fill(&info, map);
5018 
5019 	if (bpf_map_is_offloaded(map)) {
5020 		err = bpf_map_offload_info_fill(&info, map);
5021 		if (err)
5022 			return err;
5023 	}
5024 
5025 	if (copy_to_user(uinfo, &info, info_len) ||
5026 	    put_user(info_len, &uattr->info.info_len))
5027 		return -EFAULT;
5028 
5029 	return 0;
5030 }
5031 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5032 static int bpf_btf_get_info_by_fd(struct file *file,
5033 				  struct btf *btf,
5034 				  const union bpf_attr *attr,
5035 				  union bpf_attr __user *uattr)
5036 {
5037 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5038 	u32 info_len = attr->info.info_len;
5039 	int err;
5040 
5041 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5042 	if (err)
5043 		return err;
5044 
5045 	return btf_get_info_by_fd(btf, attr, uattr);
5046 }
5047 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5048 static int bpf_link_get_info_by_fd(struct file *file,
5049 				  struct bpf_link *link,
5050 				  const union bpf_attr *attr,
5051 				  union bpf_attr __user *uattr)
5052 {
5053 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5054 	struct bpf_link_info info;
5055 	u32 info_len = attr->info.info_len;
5056 	int err;
5057 
5058 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5059 	if (err)
5060 		return err;
5061 	info_len = min_t(u32, sizeof(info), info_len);
5062 
5063 	memset(&info, 0, sizeof(info));
5064 	if (copy_from_user(&info, uinfo, info_len))
5065 		return -EFAULT;
5066 
5067 	info.type = link->type;
5068 	info.id = link->id;
5069 	if (link->prog)
5070 		info.prog_id = link->prog->aux->id;
5071 
5072 	if (link->ops->fill_link_info) {
5073 		err = link->ops->fill_link_info(link, &info);
5074 		if (err)
5075 			return err;
5076 	}
5077 
5078 	if (copy_to_user(uinfo, &info, info_len) ||
5079 	    put_user(info_len, &uattr->info.info_len))
5080 		return -EFAULT;
5081 
5082 	return 0;
5083 }
5084 
5085 
5086 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5087 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5088 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5089 				  union bpf_attr __user *uattr)
5090 {
5091 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5092 		return -EINVAL;
5093 
5094 	CLASS(fd, f)(attr->info.bpf_fd);
5095 	if (fd_empty(f))
5096 		return -EBADFD;
5097 
5098 	if (fd_file(f)->f_op == &bpf_prog_fops)
5099 		return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5100 					      uattr);
5101 	else if (fd_file(f)->f_op == &bpf_map_fops)
5102 		return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5103 					     uattr);
5104 	else if (fd_file(f)->f_op == &btf_fops)
5105 		return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5106 	else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5107 		return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5108 					      attr, uattr);
5109 	return -EINVAL;
5110 }
5111 
5112 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5113 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5114 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5115 {
5116 	struct bpf_token *token = NULL;
5117 
5118 	if (CHECK_ATTR(BPF_BTF_LOAD))
5119 		return -EINVAL;
5120 
5121 	if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5122 		return -EINVAL;
5123 
5124 	if (attr->btf_flags & BPF_F_TOKEN_FD) {
5125 		token = bpf_token_get_from_fd(attr->btf_token_fd);
5126 		if (IS_ERR(token))
5127 			return PTR_ERR(token);
5128 		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5129 			bpf_token_put(token);
5130 			token = NULL;
5131 		}
5132 	}
5133 
5134 	if (!bpf_token_capable(token, CAP_BPF)) {
5135 		bpf_token_put(token);
5136 		return -EPERM;
5137 	}
5138 
5139 	bpf_token_put(token);
5140 
5141 	return btf_new_fd(attr, uattr, uattr_size);
5142 }
5143 
5144 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5145 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5146 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5147 {
5148 	struct bpf_token *token = NULL;
5149 
5150 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5151 		return -EINVAL;
5152 
5153 	if (attr->open_flags & ~BPF_F_TOKEN_FD)
5154 		return -EINVAL;
5155 
5156 	if (attr->open_flags & BPF_F_TOKEN_FD) {
5157 		token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5158 		if (IS_ERR(token))
5159 			return PTR_ERR(token);
5160 		if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5161 			bpf_token_put(token);
5162 			token = NULL;
5163 		}
5164 	}
5165 
5166 	if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5167 		bpf_token_put(token);
5168 		return -EPERM;
5169 	}
5170 
5171 	bpf_token_put(token);
5172 
5173 	return btf_get_fd_by_id(attr->btf_id);
5174 }
5175 
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)5176 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5177 				    union bpf_attr __user *uattr,
5178 				    u32 prog_id, u32 fd_type,
5179 				    const char *buf, u64 probe_offset,
5180 				    u64 probe_addr)
5181 {
5182 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5183 	u32 len = buf ? strlen(buf) : 0, input_len;
5184 	int err = 0;
5185 
5186 	if (put_user(len, &uattr->task_fd_query.buf_len))
5187 		return -EFAULT;
5188 	input_len = attr->task_fd_query.buf_len;
5189 	if (input_len && ubuf) {
5190 		if (!len) {
5191 			/* nothing to copy, just make ubuf NULL terminated */
5192 			char zero = '\0';
5193 
5194 			if (put_user(zero, ubuf))
5195 				return -EFAULT;
5196 		} else if (input_len >= len + 1) {
5197 			/* ubuf can hold the string with NULL terminator */
5198 			if (copy_to_user(ubuf, buf, len + 1))
5199 				return -EFAULT;
5200 		} else {
5201 			/* ubuf cannot hold the string with NULL terminator,
5202 			 * do a partial copy with NULL terminator.
5203 			 */
5204 			char zero = '\0';
5205 
5206 			err = -ENOSPC;
5207 			if (copy_to_user(ubuf, buf, input_len - 1))
5208 				return -EFAULT;
5209 			if (put_user(zero, ubuf + input_len - 1))
5210 				return -EFAULT;
5211 		}
5212 	}
5213 
5214 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5215 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5216 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5217 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5218 		return -EFAULT;
5219 
5220 	return err;
5221 }
5222 
5223 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5224 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5225 static int bpf_task_fd_query(const union bpf_attr *attr,
5226 			     union bpf_attr __user *uattr)
5227 {
5228 	pid_t pid = attr->task_fd_query.pid;
5229 	u32 fd = attr->task_fd_query.fd;
5230 	const struct perf_event *event;
5231 	struct task_struct *task;
5232 	struct file *file;
5233 	int err;
5234 
5235 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5236 		return -EINVAL;
5237 
5238 	if (!capable(CAP_SYS_ADMIN))
5239 		return -EPERM;
5240 
5241 	if (attr->task_fd_query.flags != 0)
5242 		return -EINVAL;
5243 
5244 	rcu_read_lock();
5245 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5246 	rcu_read_unlock();
5247 	if (!task)
5248 		return -ENOENT;
5249 
5250 	err = 0;
5251 	file = fget_task(task, fd);
5252 	put_task_struct(task);
5253 	if (!file)
5254 		return -EBADF;
5255 
5256 	if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5257 		struct bpf_link *link = file->private_data;
5258 
5259 		if (link->ops == &bpf_raw_tp_link_lops) {
5260 			struct bpf_raw_tp_link *raw_tp =
5261 				container_of(link, struct bpf_raw_tp_link, link);
5262 			struct bpf_raw_event_map *btp = raw_tp->btp;
5263 
5264 			err = bpf_task_fd_query_copy(attr, uattr,
5265 						     raw_tp->link.prog->aux->id,
5266 						     BPF_FD_TYPE_RAW_TRACEPOINT,
5267 						     btp->tp->name, 0, 0);
5268 			goto put_file;
5269 		}
5270 		goto out_not_supp;
5271 	}
5272 
5273 	event = perf_get_event(file);
5274 	if (!IS_ERR(event)) {
5275 		u64 probe_offset, probe_addr;
5276 		u32 prog_id, fd_type;
5277 		const char *buf;
5278 
5279 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5280 					      &buf, &probe_offset,
5281 					      &probe_addr, NULL);
5282 		if (!err)
5283 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5284 						     fd_type, buf,
5285 						     probe_offset,
5286 						     probe_addr);
5287 		goto put_file;
5288 	}
5289 
5290 out_not_supp:
5291 	err = -ENOTSUPP;
5292 put_file:
5293 	fput(file);
5294 	return err;
5295 }
5296 
5297 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5298 
5299 #define BPF_DO_BATCH(fn, ...)			\
5300 	do {					\
5301 		if (!fn) {			\
5302 			err = -ENOTSUPP;	\
5303 			goto err_put;		\
5304 		}				\
5305 		err = fn(__VA_ARGS__);		\
5306 	} while (0)
5307 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5308 static int bpf_map_do_batch(const union bpf_attr *attr,
5309 			    union bpf_attr __user *uattr,
5310 			    int cmd)
5311 {
5312 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
5313 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5314 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5315 	struct bpf_map *map;
5316 	int err;
5317 
5318 	if (CHECK_ATTR(BPF_MAP_BATCH))
5319 		return -EINVAL;
5320 
5321 	CLASS(fd, f)(attr->batch.map_fd);
5322 
5323 	map = __bpf_map_get(f);
5324 	if (IS_ERR(map))
5325 		return PTR_ERR(map);
5326 	if (has_write)
5327 		bpf_map_write_active_inc(map);
5328 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5329 		err = -EPERM;
5330 		goto err_put;
5331 	}
5332 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5333 		err = -EPERM;
5334 		goto err_put;
5335 	}
5336 
5337 	if (cmd == BPF_MAP_LOOKUP_BATCH)
5338 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5339 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5340 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5341 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5342 		BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5343 	else
5344 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5345 err_put:
5346 	if (has_write) {
5347 		maybe_wait_bpf_programs(map);
5348 		bpf_map_write_active_dec(map);
5349 	}
5350 	return err;
5351 }
5352 
5353 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5354 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5355 {
5356 	struct bpf_prog *prog;
5357 	int ret;
5358 
5359 	if (CHECK_ATTR(BPF_LINK_CREATE))
5360 		return -EINVAL;
5361 
5362 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5363 		return bpf_struct_ops_link_create(attr);
5364 
5365 	prog = bpf_prog_get(attr->link_create.prog_fd);
5366 	if (IS_ERR(prog))
5367 		return PTR_ERR(prog);
5368 
5369 	ret = bpf_prog_attach_check_attach_type(prog,
5370 						attr->link_create.attach_type);
5371 	if (ret)
5372 		goto out;
5373 
5374 	switch (prog->type) {
5375 	case BPF_PROG_TYPE_CGROUP_SKB:
5376 	case BPF_PROG_TYPE_CGROUP_SOCK:
5377 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5378 	case BPF_PROG_TYPE_SOCK_OPS:
5379 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5380 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5381 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5382 		ret = cgroup_bpf_link_attach(attr, prog);
5383 		break;
5384 	case BPF_PROG_TYPE_EXT:
5385 		ret = bpf_tracing_prog_attach(prog,
5386 					      attr->link_create.target_fd,
5387 					      attr->link_create.target_btf_id,
5388 					      attr->link_create.tracing.cookie);
5389 		break;
5390 	case BPF_PROG_TYPE_LSM:
5391 	case BPF_PROG_TYPE_TRACING:
5392 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5393 			ret = -EINVAL;
5394 			goto out;
5395 		}
5396 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5397 			ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie);
5398 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5399 			ret = bpf_iter_link_attach(attr, uattr, prog);
5400 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5401 			ret = cgroup_bpf_link_attach(attr, prog);
5402 		else
5403 			ret = bpf_tracing_prog_attach(prog,
5404 						      attr->link_create.target_fd,
5405 						      attr->link_create.target_btf_id,
5406 						      attr->link_create.tracing.cookie);
5407 		break;
5408 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5409 	case BPF_PROG_TYPE_SK_LOOKUP:
5410 		ret = netns_bpf_link_create(attr, prog);
5411 		break;
5412 	case BPF_PROG_TYPE_SK_MSG:
5413 	case BPF_PROG_TYPE_SK_SKB:
5414 		ret = sock_map_link_create(attr, prog);
5415 		break;
5416 #ifdef CONFIG_NET
5417 	case BPF_PROG_TYPE_XDP:
5418 		ret = bpf_xdp_link_attach(attr, prog);
5419 		break;
5420 	case BPF_PROG_TYPE_SCHED_CLS:
5421 		if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5422 		    attr->link_create.attach_type == BPF_TCX_EGRESS)
5423 			ret = tcx_link_attach(attr, prog);
5424 		else
5425 			ret = netkit_link_attach(attr, prog);
5426 		break;
5427 	case BPF_PROG_TYPE_NETFILTER:
5428 		ret = bpf_nf_link_attach(attr, prog);
5429 		break;
5430 #endif
5431 	case BPF_PROG_TYPE_PERF_EVENT:
5432 	case BPF_PROG_TYPE_TRACEPOINT:
5433 		ret = bpf_perf_link_attach(attr, prog);
5434 		break;
5435 	case BPF_PROG_TYPE_KPROBE:
5436 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5437 			ret = bpf_perf_link_attach(attr, prog);
5438 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5439 			 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5440 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5441 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5442 			 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5443 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5444 		break;
5445 	default:
5446 		ret = -EINVAL;
5447 	}
5448 
5449 out:
5450 	if (ret < 0)
5451 		bpf_prog_put(prog);
5452 	return ret;
5453 }
5454 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5455 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5456 {
5457 	struct bpf_map *new_map, *old_map = NULL;
5458 	int ret;
5459 
5460 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5461 	if (IS_ERR(new_map))
5462 		return PTR_ERR(new_map);
5463 
5464 	if (attr->link_update.flags & BPF_F_REPLACE) {
5465 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5466 		if (IS_ERR(old_map)) {
5467 			ret = PTR_ERR(old_map);
5468 			goto out_put;
5469 		}
5470 	} else if (attr->link_update.old_map_fd) {
5471 		ret = -EINVAL;
5472 		goto out_put;
5473 	}
5474 
5475 	ret = link->ops->update_map(link, new_map, old_map);
5476 
5477 	if (old_map)
5478 		bpf_map_put(old_map);
5479 out_put:
5480 	bpf_map_put(new_map);
5481 	return ret;
5482 }
5483 
5484 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5485 
link_update(union bpf_attr * attr)5486 static int link_update(union bpf_attr *attr)
5487 {
5488 	struct bpf_prog *old_prog = NULL, *new_prog;
5489 	struct bpf_link *link;
5490 	u32 flags;
5491 	int ret;
5492 
5493 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5494 		return -EINVAL;
5495 
5496 	flags = attr->link_update.flags;
5497 	if (flags & ~BPF_F_REPLACE)
5498 		return -EINVAL;
5499 
5500 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5501 	if (IS_ERR(link))
5502 		return PTR_ERR(link);
5503 
5504 	if (link->ops->update_map) {
5505 		ret = link_update_map(link, attr);
5506 		goto out_put_link;
5507 	}
5508 
5509 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5510 	if (IS_ERR(new_prog)) {
5511 		ret = PTR_ERR(new_prog);
5512 		goto out_put_link;
5513 	}
5514 
5515 	if (flags & BPF_F_REPLACE) {
5516 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5517 		if (IS_ERR(old_prog)) {
5518 			ret = PTR_ERR(old_prog);
5519 			old_prog = NULL;
5520 			goto out_put_progs;
5521 		}
5522 	} else if (attr->link_update.old_prog_fd) {
5523 		ret = -EINVAL;
5524 		goto out_put_progs;
5525 	}
5526 
5527 	if (link->ops->update_prog)
5528 		ret = link->ops->update_prog(link, new_prog, old_prog);
5529 	else
5530 		ret = -EINVAL;
5531 
5532 out_put_progs:
5533 	if (old_prog)
5534 		bpf_prog_put(old_prog);
5535 	if (ret)
5536 		bpf_prog_put(new_prog);
5537 out_put_link:
5538 	bpf_link_put_direct(link);
5539 	return ret;
5540 }
5541 
5542 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5543 
link_detach(union bpf_attr * attr)5544 static int link_detach(union bpf_attr *attr)
5545 {
5546 	struct bpf_link *link;
5547 	int ret;
5548 
5549 	if (CHECK_ATTR(BPF_LINK_DETACH))
5550 		return -EINVAL;
5551 
5552 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5553 	if (IS_ERR(link))
5554 		return PTR_ERR(link);
5555 
5556 	if (link->ops->detach)
5557 		ret = link->ops->detach(link);
5558 	else
5559 		ret = -EOPNOTSUPP;
5560 
5561 	bpf_link_put_direct(link);
5562 	return ret;
5563 }
5564 
bpf_link_inc_not_zero(struct bpf_link * link)5565 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5566 {
5567 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5568 }
5569 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5570 
bpf_link_by_id(u32 id)5571 struct bpf_link *bpf_link_by_id(u32 id)
5572 {
5573 	struct bpf_link *link;
5574 
5575 	if (!id)
5576 		return ERR_PTR(-ENOENT);
5577 
5578 	spin_lock_bh(&link_idr_lock);
5579 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5580 	link = idr_find(&link_idr, id);
5581 	if (link) {
5582 		if (link->id)
5583 			link = bpf_link_inc_not_zero(link);
5584 		else
5585 			link = ERR_PTR(-EAGAIN);
5586 	} else {
5587 		link = ERR_PTR(-ENOENT);
5588 	}
5589 	spin_unlock_bh(&link_idr_lock);
5590 	return link;
5591 }
5592 
bpf_link_get_curr_or_next(u32 * id)5593 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5594 {
5595 	struct bpf_link *link;
5596 
5597 	spin_lock_bh(&link_idr_lock);
5598 again:
5599 	link = idr_get_next(&link_idr, id);
5600 	if (link) {
5601 		link = bpf_link_inc_not_zero(link);
5602 		if (IS_ERR(link)) {
5603 			(*id)++;
5604 			goto again;
5605 		}
5606 	}
5607 	spin_unlock_bh(&link_idr_lock);
5608 
5609 	return link;
5610 }
5611 
5612 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5613 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5614 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5615 {
5616 	struct bpf_link *link;
5617 	u32 id = attr->link_id;
5618 	int fd;
5619 
5620 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5621 		return -EINVAL;
5622 
5623 	if (!capable(CAP_SYS_ADMIN))
5624 		return -EPERM;
5625 
5626 	link = bpf_link_by_id(id);
5627 	if (IS_ERR(link))
5628 		return PTR_ERR(link);
5629 
5630 	fd = bpf_link_new_fd(link);
5631 	if (fd < 0)
5632 		bpf_link_put_direct(link);
5633 
5634 	return fd;
5635 }
5636 
5637 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5638 
bpf_stats_release(struct inode * inode,struct file * file)5639 static int bpf_stats_release(struct inode *inode, struct file *file)
5640 {
5641 	mutex_lock(&bpf_stats_enabled_mutex);
5642 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5643 	mutex_unlock(&bpf_stats_enabled_mutex);
5644 	return 0;
5645 }
5646 
5647 static const struct file_operations bpf_stats_fops = {
5648 	.release = bpf_stats_release,
5649 };
5650 
bpf_enable_runtime_stats(void)5651 static int bpf_enable_runtime_stats(void)
5652 {
5653 	int fd;
5654 
5655 	mutex_lock(&bpf_stats_enabled_mutex);
5656 
5657 	/* Set a very high limit to avoid overflow */
5658 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5659 		mutex_unlock(&bpf_stats_enabled_mutex);
5660 		return -EBUSY;
5661 	}
5662 
5663 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5664 	if (fd >= 0)
5665 		static_key_slow_inc(&bpf_stats_enabled_key.key);
5666 
5667 	mutex_unlock(&bpf_stats_enabled_mutex);
5668 	return fd;
5669 }
5670 
5671 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5672 
bpf_enable_stats(union bpf_attr * attr)5673 static int bpf_enable_stats(union bpf_attr *attr)
5674 {
5675 
5676 	if (CHECK_ATTR(BPF_ENABLE_STATS))
5677 		return -EINVAL;
5678 
5679 	if (!capable(CAP_SYS_ADMIN))
5680 		return -EPERM;
5681 
5682 	switch (attr->enable_stats.type) {
5683 	case BPF_STATS_RUN_TIME:
5684 		return bpf_enable_runtime_stats();
5685 	default:
5686 		break;
5687 	}
5688 	return -EINVAL;
5689 }
5690 
5691 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
5692 
bpf_iter_create(union bpf_attr * attr)5693 static int bpf_iter_create(union bpf_attr *attr)
5694 {
5695 	struct bpf_link *link;
5696 	int err;
5697 
5698 	if (CHECK_ATTR(BPF_ITER_CREATE))
5699 		return -EINVAL;
5700 
5701 	if (attr->iter_create.flags)
5702 		return -EINVAL;
5703 
5704 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
5705 	if (IS_ERR(link))
5706 		return PTR_ERR(link);
5707 
5708 	err = bpf_iter_new_fd(link);
5709 	bpf_link_put_direct(link);
5710 
5711 	return err;
5712 }
5713 
5714 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
5715 
bpf_prog_bind_map(union bpf_attr * attr)5716 static int bpf_prog_bind_map(union bpf_attr *attr)
5717 {
5718 	struct bpf_prog *prog;
5719 	struct bpf_map *map;
5720 	struct bpf_map **used_maps_old, **used_maps_new;
5721 	int i, ret = 0;
5722 
5723 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
5724 		return -EINVAL;
5725 
5726 	if (attr->prog_bind_map.flags)
5727 		return -EINVAL;
5728 
5729 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
5730 	if (IS_ERR(prog))
5731 		return PTR_ERR(prog);
5732 
5733 	map = bpf_map_get(attr->prog_bind_map.map_fd);
5734 	if (IS_ERR(map)) {
5735 		ret = PTR_ERR(map);
5736 		goto out_prog_put;
5737 	}
5738 
5739 	mutex_lock(&prog->aux->used_maps_mutex);
5740 
5741 	used_maps_old = prog->aux->used_maps;
5742 
5743 	for (i = 0; i < prog->aux->used_map_cnt; i++)
5744 		if (used_maps_old[i] == map) {
5745 			bpf_map_put(map);
5746 			goto out_unlock;
5747 		}
5748 
5749 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
5750 				      sizeof(used_maps_new[0]),
5751 				      GFP_KERNEL);
5752 	if (!used_maps_new) {
5753 		ret = -ENOMEM;
5754 		goto out_unlock;
5755 	}
5756 
5757 	/* The bpf program will not access the bpf map, but for the sake of
5758 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
5759 	 */
5760 	if (prog->sleepable)
5761 		atomic64_inc(&map->sleepable_refcnt);
5762 	memcpy(used_maps_new, used_maps_old,
5763 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
5764 	used_maps_new[prog->aux->used_map_cnt] = map;
5765 
5766 	prog->aux->used_map_cnt++;
5767 	prog->aux->used_maps = used_maps_new;
5768 
5769 	kfree(used_maps_old);
5770 
5771 out_unlock:
5772 	mutex_unlock(&prog->aux->used_maps_mutex);
5773 
5774 	if (ret)
5775 		bpf_map_put(map);
5776 out_prog_put:
5777 	bpf_prog_put(prog);
5778 	return ret;
5779 }
5780 
5781 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
5782 
token_create(union bpf_attr * attr)5783 static int token_create(union bpf_attr *attr)
5784 {
5785 	if (CHECK_ATTR(BPF_TOKEN_CREATE))
5786 		return -EINVAL;
5787 
5788 	/* no flags are supported yet */
5789 	if (attr->token_create.flags)
5790 		return -EINVAL;
5791 
5792 	return bpf_token_create(attr);
5793 }
5794 
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)5795 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
5796 {
5797 	union bpf_attr attr;
5798 	int err;
5799 
5800 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
5801 	if (err)
5802 		return err;
5803 	size = min_t(u32, size, sizeof(attr));
5804 
5805 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
5806 	memset(&attr, 0, sizeof(attr));
5807 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
5808 		return -EFAULT;
5809 
5810 	err = security_bpf(cmd, &attr, size, uattr.is_kernel);
5811 	if (err < 0)
5812 		return err;
5813 
5814 	switch (cmd) {
5815 	case BPF_MAP_CREATE:
5816 		err = map_create(&attr, uattr.is_kernel);
5817 		break;
5818 	case BPF_MAP_LOOKUP_ELEM:
5819 		err = map_lookup_elem(&attr);
5820 		break;
5821 	case BPF_MAP_UPDATE_ELEM:
5822 		err = map_update_elem(&attr, uattr);
5823 		break;
5824 	case BPF_MAP_DELETE_ELEM:
5825 		err = map_delete_elem(&attr, uattr);
5826 		break;
5827 	case BPF_MAP_GET_NEXT_KEY:
5828 		err = map_get_next_key(&attr);
5829 		break;
5830 	case BPF_MAP_FREEZE:
5831 		err = map_freeze(&attr);
5832 		break;
5833 	case BPF_PROG_LOAD:
5834 		err = bpf_prog_load(&attr, uattr, size);
5835 		break;
5836 	case BPF_OBJ_PIN:
5837 		err = bpf_obj_pin(&attr);
5838 		break;
5839 	case BPF_OBJ_GET:
5840 		err = bpf_obj_get(&attr);
5841 		break;
5842 	case BPF_PROG_ATTACH:
5843 		err = bpf_prog_attach(&attr);
5844 		break;
5845 	case BPF_PROG_DETACH:
5846 		err = bpf_prog_detach(&attr);
5847 		break;
5848 	case BPF_PROG_QUERY:
5849 		err = bpf_prog_query(&attr, uattr.user);
5850 		break;
5851 	case BPF_PROG_TEST_RUN:
5852 		err = bpf_prog_test_run(&attr, uattr.user);
5853 		break;
5854 	case BPF_PROG_GET_NEXT_ID:
5855 		err = bpf_obj_get_next_id(&attr, uattr.user,
5856 					  &prog_idr, &prog_idr_lock);
5857 		break;
5858 	case BPF_MAP_GET_NEXT_ID:
5859 		err = bpf_obj_get_next_id(&attr, uattr.user,
5860 					  &map_idr, &map_idr_lock);
5861 		break;
5862 	case BPF_BTF_GET_NEXT_ID:
5863 		err = bpf_obj_get_next_id(&attr, uattr.user,
5864 					  &btf_idr, &btf_idr_lock);
5865 		break;
5866 	case BPF_PROG_GET_FD_BY_ID:
5867 		err = bpf_prog_get_fd_by_id(&attr);
5868 		break;
5869 	case BPF_MAP_GET_FD_BY_ID:
5870 		err = bpf_map_get_fd_by_id(&attr);
5871 		break;
5872 	case BPF_OBJ_GET_INFO_BY_FD:
5873 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
5874 		break;
5875 	case BPF_RAW_TRACEPOINT_OPEN:
5876 		err = bpf_raw_tracepoint_open(&attr);
5877 		break;
5878 	case BPF_BTF_LOAD:
5879 		err = bpf_btf_load(&attr, uattr, size);
5880 		break;
5881 	case BPF_BTF_GET_FD_BY_ID:
5882 		err = bpf_btf_get_fd_by_id(&attr);
5883 		break;
5884 	case BPF_TASK_FD_QUERY:
5885 		err = bpf_task_fd_query(&attr, uattr.user);
5886 		break;
5887 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
5888 		err = map_lookup_and_delete_elem(&attr);
5889 		break;
5890 	case BPF_MAP_LOOKUP_BATCH:
5891 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
5892 		break;
5893 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
5894 		err = bpf_map_do_batch(&attr, uattr.user,
5895 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
5896 		break;
5897 	case BPF_MAP_UPDATE_BATCH:
5898 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
5899 		break;
5900 	case BPF_MAP_DELETE_BATCH:
5901 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
5902 		break;
5903 	case BPF_LINK_CREATE:
5904 		err = link_create(&attr, uattr);
5905 		break;
5906 	case BPF_LINK_UPDATE:
5907 		err = link_update(&attr);
5908 		break;
5909 	case BPF_LINK_GET_FD_BY_ID:
5910 		err = bpf_link_get_fd_by_id(&attr);
5911 		break;
5912 	case BPF_LINK_GET_NEXT_ID:
5913 		err = bpf_obj_get_next_id(&attr, uattr.user,
5914 					  &link_idr, &link_idr_lock);
5915 		break;
5916 	case BPF_ENABLE_STATS:
5917 		err = bpf_enable_stats(&attr);
5918 		break;
5919 	case BPF_ITER_CREATE:
5920 		err = bpf_iter_create(&attr);
5921 		break;
5922 	case BPF_LINK_DETACH:
5923 		err = link_detach(&attr);
5924 		break;
5925 	case BPF_PROG_BIND_MAP:
5926 		err = bpf_prog_bind_map(&attr);
5927 		break;
5928 	case BPF_TOKEN_CREATE:
5929 		err = token_create(&attr);
5930 		break;
5931 	default:
5932 		err = -EINVAL;
5933 		break;
5934 	}
5935 
5936 	return err;
5937 }
5938 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5939 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5940 {
5941 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5942 }
5943 
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)5944 static bool syscall_prog_is_valid_access(int off, int size,
5945 					 enum bpf_access_type type,
5946 					 const struct bpf_prog *prog,
5947 					 struct bpf_insn_access_aux *info)
5948 {
5949 	if (off < 0 || off >= U16_MAX)
5950 		return false;
5951 	if (off % size != 0)
5952 		return false;
5953 	return true;
5954 }
5955 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5956 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5957 {
5958 	switch (cmd) {
5959 	case BPF_MAP_CREATE:
5960 	case BPF_MAP_DELETE_ELEM:
5961 	case BPF_MAP_UPDATE_ELEM:
5962 	case BPF_MAP_FREEZE:
5963 	case BPF_MAP_GET_FD_BY_ID:
5964 	case BPF_PROG_LOAD:
5965 	case BPF_BTF_LOAD:
5966 	case BPF_LINK_CREATE:
5967 	case BPF_RAW_TRACEPOINT_OPEN:
5968 		break;
5969 	default:
5970 		return -EINVAL;
5971 	}
5972 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5973 }
5974 
5975 
5976 /* To shut up -Wmissing-prototypes.
5977  * This function is used by the kernel light skeleton
5978  * to load bpf programs when modules are loaded or during kernel boot.
5979  * See tools/lib/bpf/skel_internal.h
5980  */
5981 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
5982 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5983 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5984 {
5985 	struct bpf_prog * __maybe_unused prog;
5986 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5987 
5988 	switch (cmd) {
5989 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5990 	case BPF_PROG_TEST_RUN:
5991 		if (attr->test.data_in || attr->test.data_out ||
5992 		    attr->test.ctx_out || attr->test.duration ||
5993 		    attr->test.repeat || attr->test.flags)
5994 			return -EINVAL;
5995 
5996 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5997 		if (IS_ERR(prog))
5998 			return PTR_ERR(prog);
5999 
6000 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6001 		    attr->test.ctx_size_in > U16_MAX) {
6002 			bpf_prog_put(prog);
6003 			return -EINVAL;
6004 		}
6005 
6006 		run_ctx.bpf_cookie = 0;
6007 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6008 			/* recursion detected */
6009 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6010 			bpf_prog_put(prog);
6011 			return -EBUSY;
6012 		}
6013 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6014 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6015 						&run_ctx);
6016 		bpf_prog_put(prog);
6017 		return 0;
6018 #endif
6019 	default:
6020 		return ____bpf_sys_bpf(cmd, attr, size);
6021 	}
6022 }
6023 EXPORT_SYMBOL(kern_sys_bpf);
6024 
6025 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6026 	.func		= bpf_sys_bpf,
6027 	.gpl_only	= false,
6028 	.ret_type	= RET_INTEGER,
6029 	.arg1_type	= ARG_ANYTHING,
6030 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
6031 	.arg3_type	= ARG_CONST_SIZE,
6032 };
6033 
6034 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6035 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6036 {
6037 	return bpf_base_func_proto(func_id, prog);
6038 }
6039 
BPF_CALL_1(bpf_sys_close,u32,fd)6040 BPF_CALL_1(bpf_sys_close, u32, fd)
6041 {
6042 	/* When bpf program calls this helper there should not be
6043 	 * an fdget() without matching completed fdput().
6044 	 * This helper is allowed in the following callchain only:
6045 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6046 	 */
6047 	return close_fd(fd);
6048 }
6049 
6050 static const struct bpf_func_proto bpf_sys_close_proto = {
6051 	.func		= bpf_sys_close,
6052 	.gpl_only	= false,
6053 	.ret_type	= RET_INTEGER,
6054 	.arg1_type	= ARG_ANYTHING,
6055 };
6056 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6057 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6058 {
6059 	*res = 0;
6060 	if (flags)
6061 		return -EINVAL;
6062 
6063 	if (name_sz <= 1 || name[name_sz - 1])
6064 		return -EINVAL;
6065 
6066 	if (!bpf_dump_raw_ok(current_cred()))
6067 		return -EPERM;
6068 
6069 	*res = kallsyms_lookup_name(name);
6070 	return *res ? 0 : -ENOENT;
6071 }
6072 
6073 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6074 	.func		= bpf_kallsyms_lookup_name,
6075 	.gpl_only	= false,
6076 	.ret_type	= RET_INTEGER,
6077 	.arg1_type	= ARG_PTR_TO_MEM,
6078 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
6079 	.arg3_type	= ARG_ANYTHING,
6080 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6081 	.arg4_size	= sizeof(u64),
6082 };
6083 
6084 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6085 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6086 {
6087 	switch (func_id) {
6088 	case BPF_FUNC_sys_bpf:
6089 		return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6090 		       ? NULL : &bpf_sys_bpf_proto;
6091 	case BPF_FUNC_btf_find_by_name_kind:
6092 		return &bpf_btf_find_by_name_kind_proto;
6093 	case BPF_FUNC_sys_close:
6094 		return &bpf_sys_close_proto;
6095 	case BPF_FUNC_kallsyms_lookup_name:
6096 		return &bpf_kallsyms_lookup_name_proto;
6097 	default:
6098 		return tracing_prog_func_proto(func_id, prog);
6099 	}
6100 }
6101 
6102 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6103 	.get_func_proto  = syscall_prog_func_proto,
6104 	.is_valid_access = syscall_prog_is_valid_access,
6105 };
6106 
6107 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6108 	.test_run = bpf_prog_test_run_syscall,
6109 };
6110 
6111 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6112 static int bpf_stats_handler(const struct ctl_table *table, int write,
6113 			     void *buffer, size_t *lenp, loff_t *ppos)
6114 {
6115 	struct static_key *key = (struct static_key *)table->data;
6116 	static int saved_val;
6117 	int val, ret;
6118 	struct ctl_table tmp = {
6119 		.data   = &val,
6120 		.maxlen = sizeof(val),
6121 		.mode   = table->mode,
6122 		.extra1 = SYSCTL_ZERO,
6123 		.extra2 = SYSCTL_ONE,
6124 	};
6125 
6126 	if (write && !capable(CAP_SYS_ADMIN))
6127 		return -EPERM;
6128 
6129 	mutex_lock(&bpf_stats_enabled_mutex);
6130 	val = saved_val;
6131 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6132 	if (write && !ret && val != saved_val) {
6133 		if (val)
6134 			static_key_slow_inc(key);
6135 		else
6136 			static_key_slow_dec(key);
6137 		saved_val = val;
6138 	}
6139 	mutex_unlock(&bpf_stats_enabled_mutex);
6140 	return ret;
6141 }
6142 
unpriv_ebpf_notify(int new_state)6143 void __weak unpriv_ebpf_notify(int new_state)
6144 {
6145 }
6146 
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6147 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6148 			      void *buffer, size_t *lenp, loff_t *ppos)
6149 {
6150 	int ret, unpriv_enable = *(int *)table->data;
6151 	bool locked_state = unpriv_enable == 1;
6152 	struct ctl_table tmp = *table;
6153 
6154 	if (write && !capable(CAP_SYS_ADMIN))
6155 		return -EPERM;
6156 
6157 	tmp.data = &unpriv_enable;
6158 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6159 	if (write && !ret) {
6160 		if (locked_state && unpriv_enable != 1)
6161 			return -EPERM;
6162 		*(int *)table->data = unpriv_enable;
6163 	}
6164 
6165 	if (write)
6166 		unpriv_ebpf_notify(unpriv_enable);
6167 
6168 	return ret;
6169 }
6170 
6171 static const struct ctl_table bpf_syscall_table[] = {
6172 	{
6173 		.procname	= "unprivileged_bpf_disabled",
6174 		.data		= &sysctl_unprivileged_bpf_disabled,
6175 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
6176 		.mode		= 0644,
6177 		.proc_handler	= bpf_unpriv_handler,
6178 		.extra1		= SYSCTL_ZERO,
6179 		.extra2		= SYSCTL_TWO,
6180 	},
6181 	{
6182 		.procname	= "bpf_stats_enabled",
6183 		.data		= &bpf_stats_enabled_key.key,
6184 		.mode		= 0644,
6185 		.proc_handler	= bpf_stats_handler,
6186 	},
6187 };
6188 
bpf_syscall_sysctl_init(void)6189 static int __init bpf_syscall_sysctl_init(void)
6190 {
6191 	register_sysctl_init("kernel", bpf_syscall_table);
6192 	return 0;
6193 }
6194 late_initcall(bpf_syscall_sysctl_init);
6195 #endif /* CONFIG_SYSCTL */
6196