xref: /linux/kernel/bpf/syscall.c (revision 00c010e130e58301db2ea0cec1eadc931e1cb8cf)
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 #include <linux/overflow.h>
40 
41 #include <net/netfilter/nf_bpf_link.h>
42 #include <net/netkit.h>
43 #include <net/tcx.h>
44 
45 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
46 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
47 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
48 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
49 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
50 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
51 			IS_FD_HASH(map))
52 
53 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
54 
55 DEFINE_PER_CPU(int, bpf_prog_active);
56 static DEFINE_IDR(prog_idr);
57 static DEFINE_SPINLOCK(prog_idr_lock);
58 static DEFINE_IDR(map_idr);
59 static DEFINE_SPINLOCK(map_idr_lock);
60 static DEFINE_IDR(link_idr);
61 static DEFINE_SPINLOCK(link_idr_lock);
62 
63 int sysctl_unprivileged_bpf_disabled __read_mostly =
64 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
65 
66 static const struct bpf_map_ops * const bpf_map_types[] = {
67 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
68 #define BPF_MAP_TYPE(_id, _ops) \
69 	[_id] = &_ops,
70 #define BPF_LINK_TYPE(_id, _name)
71 #include <linux/bpf_types.h>
72 #undef BPF_PROG_TYPE
73 #undef BPF_MAP_TYPE
74 #undef BPF_LINK_TYPE
75 };
76 
77 /*
78  * If we're handed a bigger struct than we know of, ensure all the unknown bits
79  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
80  * we don't know about yet.
81  *
82  * There is a ToCToU between this function call and the following
83  * copy_from_user() call. However, this is not a concern since this function is
84  * meant to be a future-proofing of bits.
85  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)86 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
87 			     size_t expected_size,
88 			     size_t actual_size)
89 {
90 	int res;
91 
92 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
93 		return -E2BIG;
94 
95 	if (actual_size <= expected_size)
96 		return 0;
97 
98 	if (uaddr.is_kernel)
99 		res = memchr_inv(uaddr.kernel + expected_size, 0,
100 				 actual_size - expected_size) == NULL;
101 	else
102 		res = check_zeroed_user(uaddr.user + expected_size,
103 					actual_size - expected_size);
104 	if (res < 0)
105 		return res;
106 	return res ? 0 : -E2BIG;
107 }
108 
109 const struct bpf_map_ops bpf_map_offload_ops = {
110 	.map_meta_equal = bpf_map_meta_equal,
111 	.map_alloc = bpf_map_offload_map_alloc,
112 	.map_free = bpf_map_offload_map_free,
113 	.map_check_btf = map_check_no_btf,
114 	.map_mem_usage = bpf_map_offload_map_mem_usage,
115 };
116 
bpf_map_write_active_inc(struct bpf_map * map)117 static void bpf_map_write_active_inc(struct bpf_map *map)
118 {
119 	atomic64_inc(&map->writecnt);
120 }
121 
bpf_map_write_active_dec(struct bpf_map * map)122 static void bpf_map_write_active_dec(struct bpf_map *map)
123 {
124 	atomic64_dec(&map->writecnt);
125 }
126 
bpf_map_write_active(const struct bpf_map * map)127 bool bpf_map_write_active(const struct bpf_map *map)
128 {
129 	return atomic64_read(&map->writecnt) != 0;
130 }
131 
bpf_map_value_size(const struct bpf_map * map)132 static u32 bpf_map_value_size(const struct bpf_map *map)
133 {
134 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
135 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
136 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
137 	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
138 		return round_up(map->value_size, 8) * num_possible_cpus();
139 	else if (IS_FD_MAP(map))
140 		return sizeof(u32);
141 	else
142 		return  map->value_size;
143 }
144 
maybe_wait_bpf_programs(struct bpf_map * map)145 static void maybe_wait_bpf_programs(struct bpf_map *map)
146 {
147 	/* Wait for any running non-sleepable BPF programs to complete so that
148 	 * userspace, when we return to it, knows that all non-sleepable
149 	 * programs that could be running use the new map value. For sleepable
150 	 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
151 	 * for the completions of these programs, but considering the waiting
152 	 * time can be very long and userspace may think it will hang forever,
153 	 * so don't handle sleepable BPF programs now.
154 	 */
155 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
156 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
157 		synchronize_rcu();
158 }
159 
unpin_uptr_kaddr(void * kaddr)160 static void unpin_uptr_kaddr(void *kaddr)
161 {
162 	if (kaddr)
163 		unpin_user_page(virt_to_page(kaddr));
164 }
165 
__bpf_obj_unpin_uptrs(struct btf_record * rec,u32 cnt,void * obj)166 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj)
167 {
168 	const struct btf_field *field;
169 	void **uptr_addr;
170 	int i;
171 
172 	for (i = 0, field = rec->fields; i < cnt; i++, field++) {
173 		if (field->type != BPF_UPTR)
174 			continue;
175 
176 		uptr_addr = obj + field->offset;
177 		unpin_uptr_kaddr(*uptr_addr);
178 	}
179 }
180 
bpf_obj_unpin_uptrs(struct btf_record * rec,void * obj)181 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj)
182 {
183 	if (!btf_record_has_field(rec, BPF_UPTR))
184 		return;
185 
186 	__bpf_obj_unpin_uptrs(rec, rec->cnt, obj);
187 }
188 
bpf_obj_pin_uptrs(struct btf_record * rec,void * obj)189 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj)
190 {
191 	const struct btf_field *field;
192 	const struct btf_type *t;
193 	unsigned long start, end;
194 	struct page *page;
195 	void **uptr_addr;
196 	int i, err;
197 
198 	if (!btf_record_has_field(rec, BPF_UPTR))
199 		return 0;
200 
201 	for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) {
202 		if (field->type != BPF_UPTR)
203 			continue;
204 
205 		uptr_addr = obj + field->offset;
206 		start = *(unsigned long *)uptr_addr;
207 		if (!start)
208 			continue;
209 
210 		t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id);
211 		/* t->size was checked for zero before */
212 		if (check_add_overflow(start, t->size - 1, &end)) {
213 			err = -EFAULT;
214 			goto unpin_all;
215 		}
216 
217 		/* The uptr's struct cannot span across two pages */
218 		if ((start & PAGE_MASK) != (end & PAGE_MASK)) {
219 			err = -EOPNOTSUPP;
220 			goto unpin_all;
221 		}
222 
223 		err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page);
224 		if (err != 1)
225 			goto unpin_all;
226 
227 		if (PageHighMem(page)) {
228 			err = -EOPNOTSUPP;
229 			unpin_user_page(page);
230 			goto unpin_all;
231 		}
232 
233 		*uptr_addr = page_address(page) + offset_in_page(start);
234 	}
235 
236 	return 0;
237 
238 unpin_all:
239 	__bpf_obj_unpin_uptrs(rec, i, obj);
240 	return err;
241 }
242 
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)243 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
244 				void *key, void *value, __u64 flags)
245 {
246 	int err;
247 
248 	/* Need to create a kthread, thus must support schedule */
249 	if (bpf_map_is_offloaded(map)) {
250 		return bpf_map_offload_update_elem(map, key, value, flags);
251 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
252 		   map->map_type == BPF_MAP_TYPE_ARENA ||
253 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
254 		return map->ops->map_update_elem(map, key, value, flags);
255 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
256 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
257 		return sock_map_update_elem_sys(map, key, value, flags);
258 	} else if (IS_FD_PROG_ARRAY(map)) {
259 		return bpf_fd_array_map_update_elem(map, map_file, key, value,
260 						    flags);
261 	}
262 
263 	bpf_disable_instrumentation();
264 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
265 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
266 		err = bpf_percpu_hash_update(map, key, value, flags);
267 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
268 		err = bpf_percpu_array_update(map, key, value, flags);
269 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
270 		err = bpf_percpu_cgroup_storage_update(map, key, value,
271 						       flags);
272 	} else if (IS_FD_ARRAY(map)) {
273 		err = bpf_fd_array_map_update_elem(map, map_file, key, value,
274 						   flags);
275 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
276 		err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
277 						  flags);
278 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
279 		/* rcu_read_lock() is not needed */
280 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
281 							 flags);
282 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
283 		   map->map_type == BPF_MAP_TYPE_STACK ||
284 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
285 		err = map->ops->map_push_elem(map, value, flags);
286 	} else {
287 		err = bpf_obj_pin_uptrs(map->record, value);
288 		if (!err) {
289 			rcu_read_lock();
290 			err = map->ops->map_update_elem(map, key, value, flags);
291 			rcu_read_unlock();
292 			if (err)
293 				bpf_obj_unpin_uptrs(map->record, value);
294 		}
295 	}
296 	bpf_enable_instrumentation();
297 
298 	return err;
299 }
300 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)301 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
302 			      __u64 flags)
303 {
304 	void *ptr;
305 	int err;
306 
307 	if (bpf_map_is_offloaded(map))
308 		return bpf_map_offload_lookup_elem(map, key, value);
309 
310 	bpf_disable_instrumentation();
311 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
312 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
313 		err = bpf_percpu_hash_copy(map, key, value);
314 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
315 		err = bpf_percpu_array_copy(map, key, value);
316 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
317 		err = bpf_percpu_cgroup_storage_copy(map, key, value);
318 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
319 		err = bpf_stackmap_copy(map, key, value);
320 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
321 		err = bpf_fd_array_map_lookup_elem(map, key, value);
322 	} else if (IS_FD_HASH(map)) {
323 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
324 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
325 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
326 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
327 		   map->map_type == BPF_MAP_TYPE_STACK ||
328 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
329 		err = map->ops->map_peek_elem(map, value);
330 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
331 		/* struct_ops map requires directly updating "value" */
332 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
333 	} else {
334 		rcu_read_lock();
335 		if (map->ops->map_lookup_elem_sys_only)
336 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
337 		else
338 			ptr = map->ops->map_lookup_elem(map, key);
339 		if (IS_ERR(ptr)) {
340 			err = PTR_ERR(ptr);
341 		} else if (!ptr) {
342 			err = -ENOENT;
343 		} else {
344 			err = 0;
345 			if (flags & BPF_F_LOCK)
346 				/* lock 'ptr' and copy everything but lock */
347 				copy_map_value_locked(map, value, ptr, true);
348 			else
349 				copy_map_value(map, value, ptr);
350 			/* mask lock and timer, since value wasn't zero inited */
351 			check_and_init_map_value(map, value);
352 		}
353 		rcu_read_unlock();
354 	}
355 
356 	bpf_enable_instrumentation();
357 
358 	return err;
359 }
360 
361 /* Please, do not use this function outside from the map creation path
362  * (e.g. in map update path) without taking care of setting the active
363  * memory cgroup (see at bpf_map_kmalloc_node() for example).
364  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)365 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
366 {
367 	/* We really just want to fail instead of triggering OOM killer
368 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
369 	 * which is used for lower order allocation requests.
370 	 *
371 	 * It has been observed that higher order allocation requests done by
372 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
373 	 * to reclaim memory from the page cache, thus we set
374 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
375 	 */
376 
377 	gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
378 	unsigned int flags = 0;
379 	unsigned long align = 1;
380 	void *area;
381 
382 	if (size >= SIZE_MAX)
383 		return NULL;
384 
385 	/* kmalloc()'ed memory can't be mmap()'ed */
386 	if (mmapable) {
387 		BUG_ON(!PAGE_ALIGNED(size));
388 		align = SHMLBA;
389 		flags = VM_USERMAP;
390 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
391 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
392 				    numa_node);
393 		if (area != NULL)
394 			return area;
395 	}
396 
397 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
398 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
399 			flags, numa_node, __builtin_return_address(0));
400 }
401 
bpf_map_area_alloc(u64 size,int numa_node)402 void *bpf_map_area_alloc(u64 size, int numa_node)
403 {
404 	return __bpf_map_area_alloc(size, numa_node, false);
405 }
406 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)407 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
408 {
409 	return __bpf_map_area_alloc(size, numa_node, true);
410 }
411 
bpf_map_area_free(void * area)412 void bpf_map_area_free(void *area)
413 {
414 	kvfree(area);
415 }
416 
bpf_map_flags_retain_permanent(u32 flags)417 static u32 bpf_map_flags_retain_permanent(u32 flags)
418 {
419 	/* Some map creation flags are not tied to the map object but
420 	 * rather to the map fd instead, so they have no meaning upon
421 	 * map object inspection since multiple file descriptors with
422 	 * different (access) properties can exist here. Thus, given
423 	 * this has zero meaning for the map itself, lets clear these
424 	 * from here.
425 	 */
426 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
427 }
428 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)429 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
430 {
431 	map->map_type = attr->map_type;
432 	map->key_size = attr->key_size;
433 	map->value_size = attr->value_size;
434 	map->max_entries = attr->max_entries;
435 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
436 	map->numa_node = bpf_map_attr_numa_node(attr);
437 	map->map_extra = attr->map_extra;
438 }
439 
bpf_map_alloc_id(struct bpf_map * map)440 static int bpf_map_alloc_id(struct bpf_map *map)
441 {
442 	int id;
443 
444 	idr_preload(GFP_KERNEL);
445 	spin_lock_bh(&map_idr_lock);
446 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
447 	if (id > 0)
448 		map->id = id;
449 	spin_unlock_bh(&map_idr_lock);
450 	idr_preload_end();
451 
452 	if (WARN_ON_ONCE(!id))
453 		return -ENOSPC;
454 
455 	return id > 0 ? 0 : id;
456 }
457 
bpf_map_free_id(struct bpf_map * map)458 void bpf_map_free_id(struct bpf_map *map)
459 {
460 	unsigned long flags;
461 
462 	/* Offloaded maps are removed from the IDR store when their device
463 	 * disappears - even if someone holds an fd to them they are unusable,
464 	 * the memory is gone, all ops will fail; they are simply waiting for
465 	 * refcnt to drop to be freed.
466 	 */
467 	if (!map->id)
468 		return;
469 
470 	spin_lock_irqsave(&map_idr_lock, flags);
471 
472 	idr_remove(&map_idr, map->id);
473 	map->id = 0;
474 
475 	spin_unlock_irqrestore(&map_idr_lock, flags);
476 }
477 
478 #ifdef CONFIG_MEMCG
bpf_map_save_memcg(struct bpf_map * map)479 static void bpf_map_save_memcg(struct bpf_map *map)
480 {
481 	/* Currently if a map is created by a process belonging to the root
482 	 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
483 	 * So we have to check map->objcg for being NULL each time it's
484 	 * being used.
485 	 */
486 	if (memcg_bpf_enabled())
487 		map->objcg = get_obj_cgroup_from_current();
488 }
489 
bpf_map_release_memcg(struct bpf_map * map)490 static void bpf_map_release_memcg(struct bpf_map *map)
491 {
492 	if (map->objcg)
493 		obj_cgroup_put(map->objcg);
494 }
495 
bpf_map_get_memcg(const struct bpf_map * map)496 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
497 {
498 	if (map->objcg)
499 		return get_mem_cgroup_from_objcg(map->objcg);
500 
501 	return root_mem_cgroup;
502 }
503 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)504 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
505 			   int node)
506 {
507 	struct mem_cgroup *memcg, *old_memcg;
508 	void *ptr;
509 
510 	memcg = bpf_map_get_memcg(map);
511 	old_memcg = set_active_memcg(memcg);
512 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
513 	set_active_memcg(old_memcg);
514 	mem_cgroup_put(memcg);
515 
516 	return ptr;
517 }
518 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)519 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
520 {
521 	struct mem_cgroup *memcg, *old_memcg;
522 	void *ptr;
523 
524 	memcg = bpf_map_get_memcg(map);
525 	old_memcg = set_active_memcg(memcg);
526 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
527 	set_active_memcg(old_memcg);
528 	mem_cgroup_put(memcg);
529 
530 	return ptr;
531 }
532 
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)533 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
534 		       gfp_t flags)
535 {
536 	struct mem_cgroup *memcg, *old_memcg;
537 	void *ptr;
538 
539 	memcg = bpf_map_get_memcg(map);
540 	old_memcg = set_active_memcg(memcg);
541 	ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
542 	set_active_memcg(old_memcg);
543 	mem_cgroup_put(memcg);
544 
545 	return ptr;
546 }
547 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)548 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
549 				    size_t align, gfp_t flags)
550 {
551 	struct mem_cgroup *memcg, *old_memcg;
552 	void __percpu *ptr;
553 
554 	memcg = bpf_map_get_memcg(map);
555 	old_memcg = set_active_memcg(memcg);
556 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
557 	set_active_memcg(old_memcg);
558 	mem_cgroup_put(memcg);
559 
560 	return ptr;
561 }
562 
563 #else
bpf_map_save_memcg(struct bpf_map * map)564 static void bpf_map_save_memcg(struct bpf_map *map)
565 {
566 }
567 
bpf_map_release_memcg(struct bpf_map * map)568 static void bpf_map_release_memcg(struct bpf_map *map)
569 {
570 }
571 #endif
572 
can_alloc_pages(void)573 static bool can_alloc_pages(void)
574 {
575 	return preempt_count() == 0 && !irqs_disabled() &&
576 		!IS_ENABLED(CONFIG_PREEMPT_RT);
577 }
578 
__bpf_alloc_page(int nid)579 static struct page *__bpf_alloc_page(int nid)
580 {
581 	if (!can_alloc_pages())
582 		return alloc_pages_nolock(nid, 0);
583 
584 	return alloc_pages_node(nid,
585 				GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
586 				| __GFP_NOWARN,
587 				0);
588 }
589 
bpf_map_alloc_pages(const struct bpf_map * map,int nid,unsigned long nr_pages,struct page ** pages)590 int bpf_map_alloc_pages(const struct bpf_map *map, int nid,
591 			unsigned long nr_pages, struct page **pages)
592 {
593 	unsigned long i, j;
594 	struct page *pg;
595 	int ret = 0;
596 #ifdef CONFIG_MEMCG
597 	struct mem_cgroup *memcg, *old_memcg;
598 
599 	memcg = bpf_map_get_memcg(map);
600 	old_memcg = set_active_memcg(memcg);
601 #endif
602 	for (i = 0; i < nr_pages; i++) {
603 		pg = __bpf_alloc_page(nid);
604 
605 		if (pg) {
606 			pages[i] = pg;
607 			continue;
608 		}
609 		for (j = 0; j < i; j++)
610 			free_pages_nolock(pages[j], 0);
611 		ret = -ENOMEM;
612 		break;
613 	}
614 
615 #ifdef CONFIG_MEMCG
616 	set_active_memcg(old_memcg);
617 	mem_cgroup_put(memcg);
618 #endif
619 	return ret;
620 }
621 
622 
btf_field_cmp(const void * a,const void * b)623 static int btf_field_cmp(const void *a, const void *b)
624 {
625 	const struct btf_field *f1 = a, *f2 = b;
626 
627 	if (f1->offset < f2->offset)
628 		return -1;
629 	else if (f1->offset > f2->offset)
630 		return 1;
631 	return 0;
632 }
633 
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)634 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
635 				  u32 field_mask)
636 {
637 	struct btf_field *field;
638 
639 	if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
640 		return NULL;
641 	field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
642 	if (!field || !(field->type & field_mask))
643 		return NULL;
644 	return field;
645 }
646 
btf_record_free(struct btf_record * rec)647 void btf_record_free(struct btf_record *rec)
648 {
649 	int i;
650 
651 	if (IS_ERR_OR_NULL(rec))
652 		return;
653 	for (i = 0; i < rec->cnt; i++) {
654 		switch (rec->fields[i].type) {
655 		case BPF_KPTR_UNREF:
656 		case BPF_KPTR_REF:
657 		case BPF_KPTR_PERCPU:
658 		case BPF_UPTR:
659 			if (rec->fields[i].kptr.module)
660 				module_put(rec->fields[i].kptr.module);
661 			if (btf_is_kernel(rec->fields[i].kptr.btf))
662 				btf_put(rec->fields[i].kptr.btf);
663 			break;
664 		case BPF_LIST_HEAD:
665 		case BPF_LIST_NODE:
666 		case BPF_RB_ROOT:
667 		case BPF_RB_NODE:
668 		case BPF_SPIN_LOCK:
669 		case BPF_RES_SPIN_LOCK:
670 		case BPF_TIMER:
671 		case BPF_REFCOUNT:
672 		case BPF_WORKQUEUE:
673 			/* Nothing to release */
674 			break;
675 		default:
676 			WARN_ON_ONCE(1);
677 			continue;
678 		}
679 	}
680 	kfree(rec);
681 }
682 
bpf_map_free_record(struct bpf_map * map)683 void bpf_map_free_record(struct bpf_map *map)
684 {
685 	btf_record_free(map->record);
686 	map->record = NULL;
687 }
688 
btf_record_dup(const struct btf_record * rec)689 struct btf_record *btf_record_dup(const struct btf_record *rec)
690 {
691 	const struct btf_field *fields;
692 	struct btf_record *new_rec;
693 	int ret, size, i;
694 
695 	if (IS_ERR_OR_NULL(rec))
696 		return NULL;
697 	size = struct_size(rec, fields, rec->cnt);
698 	new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
699 	if (!new_rec)
700 		return ERR_PTR(-ENOMEM);
701 	/* Do a deep copy of the btf_record */
702 	fields = rec->fields;
703 	new_rec->cnt = 0;
704 	for (i = 0; i < rec->cnt; i++) {
705 		switch (fields[i].type) {
706 		case BPF_KPTR_UNREF:
707 		case BPF_KPTR_REF:
708 		case BPF_KPTR_PERCPU:
709 		case BPF_UPTR:
710 			if (btf_is_kernel(fields[i].kptr.btf))
711 				btf_get(fields[i].kptr.btf);
712 			if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
713 				ret = -ENXIO;
714 				goto free;
715 			}
716 			break;
717 		case BPF_LIST_HEAD:
718 		case BPF_LIST_NODE:
719 		case BPF_RB_ROOT:
720 		case BPF_RB_NODE:
721 		case BPF_SPIN_LOCK:
722 		case BPF_RES_SPIN_LOCK:
723 		case BPF_TIMER:
724 		case BPF_REFCOUNT:
725 		case BPF_WORKQUEUE:
726 			/* Nothing to acquire */
727 			break;
728 		default:
729 			ret = -EFAULT;
730 			WARN_ON_ONCE(1);
731 			goto free;
732 		}
733 		new_rec->cnt++;
734 	}
735 	return new_rec;
736 free:
737 	btf_record_free(new_rec);
738 	return ERR_PTR(ret);
739 }
740 
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)741 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
742 {
743 	bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
744 	int size;
745 
746 	if (!a_has_fields && !b_has_fields)
747 		return true;
748 	if (a_has_fields != b_has_fields)
749 		return false;
750 	if (rec_a->cnt != rec_b->cnt)
751 		return false;
752 	size = struct_size(rec_a, fields, rec_a->cnt);
753 	/* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
754 	 * members are zeroed out. So memcmp is safe to do without worrying
755 	 * about padding/unused fields.
756 	 *
757 	 * While spin_lock, timer, and kptr have no relation to map BTF,
758 	 * list_head metadata is specific to map BTF, the btf and value_rec
759 	 * members in particular. btf is the map BTF, while value_rec points to
760 	 * btf_record in that map BTF.
761 	 *
762 	 * So while by default, we don't rely on the map BTF (which the records
763 	 * were parsed from) matching for both records, which is not backwards
764 	 * compatible, in case list_head is part of it, we implicitly rely on
765 	 * that by way of depending on memcmp succeeding for it.
766 	 */
767 	return !memcmp(rec_a, rec_b, size);
768 }
769 
bpf_obj_free_timer(const struct btf_record * rec,void * obj)770 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
771 {
772 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
773 		return;
774 	bpf_timer_cancel_and_free(obj + rec->timer_off);
775 }
776 
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)777 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
778 {
779 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
780 		return;
781 	bpf_wq_cancel_and_free(obj + rec->wq_off);
782 }
783 
bpf_obj_free_fields(const struct btf_record * rec,void * obj)784 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
785 {
786 	const struct btf_field *fields;
787 	int i;
788 
789 	if (IS_ERR_OR_NULL(rec))
790 		return;
791 	fields = rec->fields;
792 	for (i = 0; i < rec->cnt; i++) {
793 		struct btf_struct_meta *pointee_struct_meta;
794 		const struct btf_field *field = &fields[i];
795 		void *field_ptr = obj + field->offset;
796 		void *xchgd_field;
797 
798 		switch (fields[i].type) {
799 		case BPF_SPIN_LOCK:
800 		case BPF_RES_SPIN_LOCK:
801 			break;
802 		case BPF_TIMER:
803 			bpf_timer_cancel_and_free(field_ptr);
804 			break;
805 		case BPF_WORKQUEUE:
806 			bpf_wq_cancel_and_free(field_ptr);
807 			break;
808 		case BPF_KPTR_UNREF:
809 			WRITE_ONCE(*(u64 *)field_ptr, 0);
810 			break;
811 		case BPF_KPTR_REF:
812 		case BPF_KPTR_PERCPU:
813 			xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
814 			if (!xchgd_field)
815 				break;
816 
817 			if (!btf_is_kernel(field->kptr.btf)) {
818 				pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
819 									   field->kptr.btf_id);
820 				__bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
821 								 pointee_struct_meta->record : NULL,
822 								 fields[i].type == BPF_KPTR_PERCPU);
823 			} else {
824 				field->kptr.dtor(xchgd_field);
825 			}
826 			break;
827 		case BPF_UPTR:
828 			/* The caller ensured that no one is using the uptr */
829 			unpin_uptr_kaddr(*(void **)field_ptr);
830 			break;
831 		case BPF_LIST_HEAD:
832 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
833 				continue;
834 			bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
835 			break;
836 		case BPF_RB_ROOT:
837 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
838 				continue;
839 			bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
840 			break;
841 		case BPF_LIST_NODE:
842 		case BPF_RB_NODE:
843 		case BPF_REFCOUNT:
844 			break;
845 		default:
846 			WARN_ON_ONCE(1);
847 			continue;
848 		}
849 	}
850 }
851 
bpf_map_free(struct bpf_map * map)852 static void bpf_map_free(struct bpf_map *map)
853 {
854 	struct btf_record *rec = map->record;
855 	struct btf *btf = map->btf;
856 
857 	/* implementation dependent freeing. Disabling migration to simplify
858 	 * the free of values or special fields allocated from bpf memory
859 	 * allocator.
860 	 */
861 	migrate_disable();
862 	map->ops->map_free(map);
863 	migrate_enable();
864 
865 	/* Delay freeing of btf_record for maps, as map_free
866 	 * callback usually needs access to them. It is better to do it here
867 	 * than require each callback to do the free itself manually.
868 	 *
869 	 * Note that the btf_record stashed in map->inner_map_meta->record was
870 	 * already freed using the map_free callback for map in map case which
871 	 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
872 	 * template bpf_map struct used during verification.
873 	 */
874 	btf_record_free(rec);
875 	/* Delay freeing of btf for maps, as map_free callback may need
876 	 * struct_meta info which will be freed with btf_put().
877 	 */
878 	btf_put(btf);
879 }
880 
881 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)882 static void bpf_map_free_deferred(struct work_struct *work)
883 {
884 	struct bpf_map *map = container_of(work, struct bpf_map, work);
885 
886 	security_bpf_map_free(map);
887 	bpf_map_release_memcg(map);
888 	bpf_map_free(map);
889 }
890 
bpf_map_put_uref(struct bpf_map * map)891 static void bpf_map_put_uref(struct bpf_map *map)
892 {
893 	if (atomic64_dec_and_test(&map->usercnt)) {
894 		if (map->ops->map_release_uref)
895 			map->ops->map_release_uref(map);
896 	}
897 }
898 
bpf_map_free_in_work(struct bpf_map * map)899 static void bpf_map_free_in_work(struct bpf_map *map)
900 {
901 	INIT_WORK(&map->work, bpf_map_free_deferred);
902 	/* Avoid spawning kworkers, since they all might contend
903 	 * for the same mutex like slab_mutex.
904 	 */
905 	queue_work(system_unbound_wq, &map->work);
906 }
907 
bpf_map_free_rcu_gp(struct rcu_head * rcu)908 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
909 {
910 	bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
911 }
912 
bpf_map_free_mult_rcu_gp(struct rcu_head * rcu)913 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
914 {
915 	if (rcu_trace_implies_rcu_gp())
916 		bpf_map_free_rcu_gp(rcu);
917 	else
918 		call_rcu(rcu, bpf_map_free_rcu_gp);
919 }
920 
921 /* decrement map refcnt and schedule it for freeing via workqueue
922  * (underlying map implementation ops->map_free() might sleep)
923  */
bpf_map_put(struct bpf_map * map)924 void bpf_map_put(struct bpf_map *map)
925 {
926 	if (atomic64_dec_and_test(&map->refcnt)) {
927 		/* bpf_map_free_id() must be called first */
928 		bpf_map_free_id(map);
929 
930 		WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
931 		if (READ_ONCE(map->free_after_mult_rcu_gp))
932 			call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
933 		else if (READ_ONCE(map->free_after_rcu_gp))
934 			call_rcu(&map->rcu, bpf_map_free_rcu_gp);
935 		else
936 			bpf_map_free_in_work(map);
937 	}
938 }
939 EXPORT_SYMBOL_GPL(bpf_map_put);
940 
bpf_map_put_with_uref(struct bpf_map * map)941 void bpf_map_put_with_uref(struct bpf_map *map)
942 {
943 	bpf_map_put_uref(map);
944 	bpf_map_put(map);
945 }
946 
bpf_map_release(struct inode * inode,struct file * filp)947 static int bpf_map_release(struct inode *inode, struct file *filp)
948 {
949 	struct bpf_map *map = filp->private_data;
950 
951 	if (map->ops->map_release)
952 		map->ops->map_release(map, filp);
953 
954 	bpf_map_put_with_uref(map);
955 	return 0;
956 }
957 
map_get_sys_perms(struct bpf_map * map,struct fd f)958 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
959 {
960 	fmode_t mode = fd_file(f)->f_mode;
961 
962 	/* Our file permissions may have been overridden by global
963 	 * map permissions facing syscall side.
964 	 */
965 	if (READ_ONCE(map->frozen))
966 		mode &= ~FMODE_CAN_WRITE;
967 	return mode;
968 }
969 
970 #ifdef CONFIG_PROC_FS
971 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)972 static u64 bpf_map_memory_usage(const struct bpf_map *map)
973 {
974 	return map->ops->map_mem_usage(map);
975 }
976 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)977 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
978 {
979 	struct bpf_map *map = filp->private_data;
980 	u32 type = 0, jited = 0;
981 
982 	if (map_type_contains_progs(map)) {
983 		spin_lock(&map->owner.lock);
984 		type  = map->owner.type;
985 		jited = map->owner.jited;
986 		spin_unlock(&map->owner.lock);
987 	}
988 
989 	seq_printf(m,
990 		   "map_type:\t%u\n"
991 		   "key_size:\t%u\n"
992 		   "value_size:\t%u\n"
993 		   "max_entries:\t%u\n"
994 		   "map_flags:\t%#x\n"
995 		   "map_extra:\t%#llx\n"
996 		   "memlock:\t%llu\n"
997 		   "map_id:\t%u\n"
998 		   "frozen:\t%u\n",
999 		   map->map_type,
1000 		   map->key_size,
1001 		   map->value_size,
1002 		   map->max_entries,
1003 		   map->map_flags,
1004 		   (unsigned long long)map->map_extra,
1005 		   bpf_map_memory_usage(map),
1006 		   map->id,
1007 		   READ_ONCE(map->frozen));
1008 	if (type) {
1009 		seq_printf(m, "owner_prog_type:\t%u\n", type);
1010 		seq_printf(m, "owner_jited:\t%u\n", jited);
1011 	}
1012 }
1013 #endif
1014 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)1015 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
1016 			      loff_t *ppos)
1017 {
1018 	/* We need this handler such that alloc_file() enables
1019 	 * f_mode with FMODE_CAN_READ.
1020 	 */
1021 	return -EINVAL;
1022 }
1023 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1024 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1025 			       size_t siz, loff_t *ppos)
1026 {
1027 	/* We need this handler such that alloc_file() enables
1028 	 * f_mode with FMODE_CAN_WRITE.
1029 	 */
1030 	return -EINVAL;
1031 }
1032 
1033 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1034 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1035 {
1036 	struct bpf_map *map = vma->vm_file->private_data;
1037 
1038 	if (vma->vm_flags & VM_MAYWRITE)
1039 		bpf_map_write_active_inc(map);
1040 }
1041 
1042 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1043 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1044 {
1045 	struct bpf_map *map = vma->vm_file->private_data;
1046 
1047 	if (vma->vm_flags & VM_MAYWRITE)
1048 		bpf_map_write_active_dec(map);
1049 }
1050 
1051 static const struct vm_operations_struct bpf_map_default_vmops = {
1052 	.open		= bpf_map_mmap_open,
1053 	.close		= bpf_map_mmap_close,
1054 };
1055 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1056 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1057 {
1058 	struct bpf_map *map = filp->private_data;
1059 	int err = 0;
1060 
1061 	if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1062 		return -ENOTSUPP;
1063 
1064 	if (!(vma->vm_flags & VM_SHARED))
1065 		return -EINVAL;
1066 
1067 	mutex_lock(&map->freeze_mutex);
1068 
1069 	if (vma->vm_flags & VM_WRITE) {
1070 		if (map->frozen) {
1071 			err = -EPERM;
1072 			goto out;
1073 		}
1074 		/* map is meant to be read-only, so do not allow mapping as
1075 		 * writable, because it's possible to leak a writable page
1076 		 * reference and allows user-space to still modify it after
1077 		 * freezing, while verifier will assume contents do not change
1078 		 */
1079 		if (map->map_flags & BPF_F_RDONLY_PROG) {
1080 			err = -EACCES;
1081 			goto out;
1082 		}
1083 		bpf_map_write_active_inc(map);
1084 	}
1085 out:
1086 	mutex_unlock(&map->freeze_mutex);
1087 	if (err)
1088 		return err;
1089 
1090 	/* set default open/close callbacks */
1091 	vma->vm_ops = &bpf_map_default_vmops;
1092 	vma->vm_private_data = map;
1093 	vm_flags_clear(vma, VM_MAYEXEC);
1094 	/* If mapping is read-only, then disallow potentially re-mapping with
1095 	 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1096 	 * means that as far as BPF map's memory-mapped VMAs are concerned,
1097 	 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1098 	 * both should be set, so we can forget about VM_MAYWRITE and always
1099 	 * check just VM_WRITE
1100 	 */
1101 	if (!(vma->vm_flags & VM_WRITE))
1102 		vm_flags_clear(vma, VM_MAYWRITE);
1103 
1104 	err = map->ops->map_mmap(map, vma);
1105 	if (err) {
1106 		if (vma->vm_flags & VM_WRITE)
1107 			bpf_map_write_active_dec(map);
1108 	}
1109 
1110 	return err;
1111 }
1112 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1113 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1114 {
1115 	struct bpf_map *map = filp->private_data;
1116 
1117 	if (map->ops->map_poll)
1118 		return map->ops->map_poll(map, filp, pts);
1119 
1120 	return EPOLLERR;
1121 }
1122 
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1123 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1124 					   unsigned long len, unsigned long pgoff,
1125 					   unsigned long flags)
1126 {
1127 	struct bpf_map *map = filp->private_data;
1128 
1129 	if (map->ops->map_get_unmapped_area)
1130 		return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1131 #ifdef CONFIG_MMU
1132 	return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
1133 #else
1134 	return addr;
1135 #endif
1136 }
1137 
1138 const struct file_operations bpf_map_fops = {
1139 #ifdef CONFIG_PROC_FS
1140 	.show_fdinfo	= bpf_map_show_fdinfo,
1141 #endif
1142 	.release	= bpf_map_release,
1143 	.read		= bpf_dummy_read,
1144 	.write		= bpf_dummy_write,
1145 	.mmap		= bpf_map_mmap,
1146 	.poll		= bpf_map_poll,
1147 	.get_unmapped_area = bpf_get_unmapped_area,
1148 };
1149 
bpf_map_new_fd(struct bpf_map * map,int flags)1150 int bpf_map_new_fd(struct bpf_map *map, int flags)
1151 {
1152 	int ret;
1153 
1154 	ret = security_bpf_map(map, OPEN_FMODE(flags));
1155 	if (ret < 0)
1156 		return ret;
1157 
1158 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1159 				flags | O_CLOEXEC);
1160 }
1161 
bpf_get_file_flag(int flags)1162 int bpf_get_file_flag(int flags)
1163 {
1164 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1165 		return -EINVAL;
1166 	if (flags & BPF_F_RDONLY)
1167 		return O_RDONLY;
1168 	if (flags & BPF_F_WRONLY)
1169 		return O_WRONLY;
1170 	return O_RDWR;
1171 }
1172 
1173 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1174 #define CHECK_ATTR(CMD) \
1175 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1176 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
1177 		   sizeof(*attr) - \
1178 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1179 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
1180 
1181 /* dst and src must have at least "size" number of bytes.
1182  * Return strlen on success and < 0 on error.
1183  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1184 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1185 {
1186 	const char *end = src + size;
1187 	const char *orig_src = src;
1188 
1189 	memset(dst, 0, size);
1190 	/* Copy all isalnum(), '_' and '.' chars. */
1191 	while (src < end && *src) {
1192 		if (!isalnum(*src) &&
1193 		    *src != '_' && *src != '.')
1194 			return -EINVAL;
1195 		*dst++ = *src++;
1196 	}
1197 
1198 	/* No '\0' found in "size" number of bytes */
1199 	if (src == end)
1200 		return -EINVAL;
1201 
1202 	return src - orig_src;
1203 }
1204 
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)1205 int map_check_no_btf(const struct bpf_map *map,
1206 		     const struct btf *btf,
1207 		     const struct btf_type *key_type,
1208 		     const struct btf_type *value_type)
1209 {
1210 	return -ENOTSUPP;
1211 }
1212 
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1213 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1214 			 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1215 {
1216 	const struct btf_type *key_type, *value_type;
1217 	u32 key_size, value_size;
1218 	int ret = 0;
1219 
1220 	/* Some maps allow key to be unspecified. */
1221 	if (btf_key_id) {
1222 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1223 		if (!key_type || key_size != map->key_size)
1224 			return -EINVAL;
1225 	} else {
1226 		key_type = btf_type_by_id(btf, 0);
1227 		if (!map->ops->map_check_btf)
1228 			return -EINVAL;
1229 	}
1230 
1231 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1232 	if (!value_type || value_size != map->value_size)
1233 		return -EINVAL;
1234 
1235 	map->record = btf_parse_fields(btf, value_type,
1236 				       BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1237 				       BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR,
1238 				       map->value_size);
1239 	if (!IS_ERR_OR_NULL(map->record)) {
1240 		int i;
1241 
1242 		if (!bpf_token_capable(token, CAP_BPF)) {
1243 			ret = -EPERM;
1244 			goto free_map_tab;
1245 		}
1246 		if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1247 			ret = -EACCES;
1248 			goto free_map_tab;
1249 		}
1250 		for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1251 			switch (map->record->field_mask & (1 << i)) {
1252 			case 0:
1253 				continue;
1254 			case BPF_SPIN_LOCK:
1255 			case BPF_RES_SPIN_LOCK:
1256 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1257 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1258 				    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1259 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1260 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1261 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1262 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1263 					ret = -EOPNOTSUPP;
1264 					goto free_map_tab;
1265 				}
1266 				break;
1267 			case BPF_TIMER:
1268 			case BPF_WORKQUEUE:
1269 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1270 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1271 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1272 					ret = -EOPNOTSUPP;
1273 					goto free_map_tab;
1274 				}
1275 				break;
1276 			case BPF_KPTR_UNREF:
1277 			case BPF_KPTR_REF:
1278 			case BPF_KPTR_PERCPU:
1279 			case BPF_REFCOUNT:
1280 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1281 				    map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1282 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1283 				    map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1284 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1285 				    map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1286 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1287 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1288 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1289 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1290 					ret = -EOPNOTSUPP;
1291 					goto free_map_tab;
1292 				}
1293 				break;
1294 			case BPF_UPTR:
1295 				if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1296 					ret = -EOPNOTSUPP;
1297 					goto free_map_tab;
1298 				}
1299 				break;
1300 			case BPF_LIST_HEAD:
1301 			case BPF_RB_ROOT:
1302 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1303 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1304 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1305 					ret = -EOPNOTSUPP;
1306 					goto free_map_tab;
1307 				}
1308 				break;
1309 			default:
1310 				/* Fail if map_type checks are missing for a field type */
1311 				ret = -EOPNOTSUPP;
1312 				goto free_map_tab;
1313 			}
1314 		}
1315 	}
1316 
1317 	ret = btf_check_and_fixup_fields(btf, map->record);
1318 	if (ret < 0)
1319 		goto free_map_tab;
1320 
1321 	if (map->ops->map_check_btf) {
1322 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1323 		if (ret < 0)
1324 			goto free_map_tab;
1325 	}
1326 
1327 	return ret;
1328 free_map_tab:
1329 	bpf_map_free_record(map);
1330 	return ret;
1331 }
1332 
bpf_net_capable(void)1333 static bool bpf_net_capable(void)
1334 {
1335 	return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
1336 }
1337 
1338 #define BPF_MAP_CREATE_LAST_FIELD map_token_fd
1339 /* called via syscall */
map_create(union bpf_attr * attr,bool kernel)1340 static int map_create(union bpf_attr *attr, bool kernel)
1341 {
1342 	const struct bpf_map_ops *ops;
1343 	struct bpf_token *token = NULL;
1344 	int numa_node = bpf_map_attr_numa_node(attr);
1345 	u32 map_type = attr->map_type;
1346 	struct bpf_map *map;
1347 	bool token_flag;
1348 	int f_flags;
1349 	int err;
1350 
1351 	err = CHECK_ATTR(BPF_MAP_CREATE);
1352 	if (err)
1353 		return -EINVAL;
1354 
1355 	/* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1356 	 * to avoid per-map type checks tripping on unknown flag
1357 	 */
1358 	token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1359 	attr->map_flags &= ~BPF_F_TOKEN_FD;
1360 
1361 	if (attr->btf_vmlinux_value_type_id) {
1362 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1363 		    attr->btf_key_type_id || attr->btf_value_type_id)
1364 			return -EINVAL;
1365 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1366 		return -EINVAL;
1367 	}
1368 
1369 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1370 	    attr->map_type != BPF_MAP_TYPE_ARENA &&
1371 	    attr->map_extra != 0)
1372 		return -EINVAL;
1373 
1374 	f_flags = bpf_get_file_flag(attr->map_flags);
1375 	if (f_flags < 0)
1376 		return f_flags;
1377 
1378 	if (numa_node != NUMA_NO_NODE &&
1379 	    ((unsigned int)numa_node >= nr_node_ids ||
1380 	     !node_online(numa_node)))
1381 		return -EINVAL;
1382 
1383 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1384 	map_type = attr->map_type;
1385 	if (map_type >= ARRAY_SIZE(bpf_map_types))
1386 		return -EINVAL;
1387 	map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1388 	ops = bpf_map_types[map_type];
1389 	if (!ops)
1390 		return -EINVAL;
1391 
1392 	if (ops->map_alloc_check) {
1393 		err = ops->map_alloc_check(attr);
1394 		if (err)
1395 			return err;
1396 	}
1397 	if (attr->map_ifindex)
1398 		ops = &bpf_map_offload_ops;
1399 	if (!ops->map_mem_usage)
1400 		return -EINVAL;
1401 
1402 	if (token_flag) {
1403 		token = bpf_token_get_from_fd(attr->map_token_fd);
1404 		if (IS_ERR(token))
1405 			return PTR_ERR(token);
1406 
1407 		/* if current token doesn't grant map creation permissions,
1408 		 * then we can't use this token, so ignore it and rely on
1409 		 * system-wide capabilities checks
1410 		 */
1411 		if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1412 		    !bpf_token_allow_map_type(token, attr->map_type)) {
1413 			bpf_token_put(token);
1414 			token = NULL;
1415 		}
1416 	}
1417 
1418 	err = -EPERM;
1419 
1420 	/* Intent here is for unprivileged_bpf_disabled to block BPF map
1421 	 * creation for unprivileged users; other actions depend
1422 	 * on fd availability and access to bpffs, so are dependent on
1423 	 * object creation success. Even with unprivileged BPF disabled,
1424 	 * capability checks are still carried out.
1425 	 */
1426 	if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1427 		goto put_token;
1428 
1429 	/* check privileged map type permissions */
1430 	switch (map_type) {
1431 	case BPF_MAP_TYPE_ARRAY:
1432 	case BPF_MAP_TYPE_PERCPU_ARRAY:
1433 	case BPF_MAP_TYPE_PROG_ARRAY:
1434 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1435 	case BPF_MAP_TYPE_CGROUP_ARRAY:
1436 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1437 	case BPF_MAP_TYPE_HASH:
1438 	case BPF_MAP_TYPE_PERCPU_HASH:
1439 	case BPF_MAP_TYPE_HASH_OF_MAPS:
1440 	case BPF_MAP_TYPE_RINGBUF:
1441 	case BPF_MAP_TYPE_USER_RINGBUF:
1442 	case BPF_MAP_TYPE_CGROUP_STORAGE:
1443 	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1444 		/* unprivileged */
1445 		break;
1446 	case BPF_MAP_TYPE_SK_STORAGE:
1447 	case BPF_MAP_TYPE_INODE_STORAGE:
1448 	case BPF_MAP_TYPE_TASK_STORAGE:
1449 	case BPF_MAP_TYPE_CGRP_STORAGE:
1450 	case BPF_MAP_TYPE_BLOOM_FILTER:
1451 	case BPF_MAP_TYPE_LPM_TRIE:
1452 	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1453 	case BPF_MAP_TYPE_STACK_TRACE:
1454 	case BPF_MAP_TYPE_QUEUE:
1455 	case BPF_MAP_TYPE_STACK:
1456 	case BPF_MAP_TYPE_LRU_HASH:
1457 	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1458 	case BPF_MAP_TYPE_STRUCT_OPS:
1459 	case BPF_MAP_TYPE_CPUMAP:
1460 	case BPF_MAP_TYPE_ARENA:
1461 		if (!bpf_token_capable(token, CAP_BPF))
1462 			goto put_token;
1463 		break;
1464 	case BPF_MAP_TYPE_SOCKMAP:
1465 	case BPF_MAP_TYPE_SOCKHASH:
1466 	case BPF_MAP_TYPE_DEVMAP:
1467 	case BPF_MAP_TYPE_DEVMAP_HASH:
1468 	case BPF_MAP_TYPE_XSKMAP:
1469 		if (!bpf_token_capable(token, CAP_NET_ADMIN))
1470 			goto put_token;
1471 		break;
1472 	default:
1473 		WARN(1, "unsupported map type %d", map_type);
1474 		goto put_token;
1475 	}
1476 
1477 	map = ops->map_alloc(attr);
1478 	if (IS_ERR(map)) {
1479 		err = PTR_ERR(map);
1480 		goto put_token;
1481 	}
1482 	map->ops = ops;
1483 	map->map_type = map_type;
1484 
1485 	err = bpf_obj_name_cpy(map->name, attr->map_name,
1486 			       sizeof(attr->map_name));
1487 	if (err < 0)
1488 		goto free_map;
1489 
1490 	atomic64_set(&map->refcnt, 1);
1491 	atomic64_set(&map->usercnt, 1);
1492 	mutex_init(&map->freeze_mutex);
1493 	spin_lock_init(&map->owner.lock);
1494 
1495 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
1496 	    /* Even the map's value is a kernel's struct,
1497 	     * the bpf_prog.o must have BTF to begin with
1498 	     * to figure out the corresponding kernel's
1499 	     * counter part.  Thus, attr->btf_fd has
1500 	     * to be valid also.
1501 	     */
1502 	    attr->btf_vmlinux_value_type_id) {
1503 		struct btf *btf;
1504 
1505 		btf = btf_get_by_fd(attr->btf_fd);
1506 		if (IS_ERR(btf)) {
1507 			err = PTR_ERR(btf);
1508 			goto free_map;
1509 		}
1510 		if (btf_is_kernel(btf)) {
1511 			btf_put(btf);
1512 			err = -EACCES;
1513 			goto free_map;
1514 		}
1515 		map->btf = btf;
1516 
1517 		if (attr->btf_value_type_id) {
1518 			err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1519 					    attr->btf_value_type_id);
1520 			if (err)
1521 				goto free_map;
1522 		}
1523 
1524 		map->btf_key_type_id = attr->btf_key_type_id;
1525 		map->btf_value_type_id = attr->btf_value_type_id;
1526 		map->btf_vmlinux_value_type_id =
1527 			attr->btf_vmlinux_value_type_id;
1528 	}
1529 
1530 	err = security_bpf_map_create(map, attr, token, kernel);
1531 	if (err)
1532 		goto free_map_sec;
1533 
1534 	err = bpf_map_alloc_id(map);
1535 	if (err)
1536 		goto free_map_sec;
1537 
1538 	bpf_map_save_memcg(map);
1539 	bpf_token_put(token);
1540 
1541 	err = bpf_map_new_fd(map, f_flags);
1542 	if (err < 0) {
1543 		/* failed to allocate fd.
1544 		 * bpf_map_put_with_uref() is needed because the above
1545 		 * bpf_map_alloc_id() has published the map
1546 		 * to the userspace and the userspace may
1547 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1548 		 */
1549 		bpf_map_put_with_uref(map);
1550 		return err;
1551 	}
1552 
1553 	return err;
1554 
1555 free_map_sec:
1556 	security_bpf_map_free(map);
1557 free_map:
1558 	bpf_map_free(map);
1559 put_token:
1560 	bpf_token_put(token);
1561 	return err;
1562 }
1563 
bpf_map_inc(struct bpf_map * map)1564 void bpf_map_inc(struct bpf_map *map)
1565 {
1566 	atomic64_inc(&map->refcnt);
1567 }
1568 EXPORT_SYMBOL_GPL(bpf_map_inc);
1569 
bpf_map_inc_with_uref(struct bpf_map * map)1570 void bpf_map_inc_with_uref(struct bpf_map *map)
1571 {
1572 	atomic64_inc(&map->refcnt);
1573 	atomic64_inc(&map->usercnt);
1574 }
1575 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1576 
bpf_map_get(u32 ufd)1577 struct bpf_map *bpf_map_get(u32 ufd)
1578 {
1579 	CLASS(fd, f)(ufd);
1580 	struct bpf_map *map = __bpf_map_get(f);
1581 
1582 	if (!IS_ERR(map))
1583 		bpf_map_inc(map);
1584 
1585 	return map;
1586 }
1587 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL");
1588 
bpf_map_get_with_uref(u32 ufd)1589 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1590 {
1591 	CLASS(fd, f)(ufd);
1592 	struct bpf_map *map = __bpf_map_get(f);
1593 
1594 	if (!IS_ERR(map))
1595 		bpf_map_inc_with_uref(map);
1596 
1597 	return map;
1598 }
1599 
1600 /* map_idr_lock should have been held or the map should have been
1601  * protected by rcu read lock.
1602  */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1603 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1604 {
1605 	int refold;
1606 
1607 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1608 	if (!refold)
1609 		return ERR_PTR(-ENOENT);
1610 	if (uref)
1611 		atomic64_inc(&map->usercnt);
1612 
1613 	return map;
1614 }
1615 
bpf_map_inc_not_zero(struct bpf_map * map)1616 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1617 {
1618 	lockdep_assert(rcu_read_lock_held());
1619 	return __bpf_map_inc_not_zero(map, false);
1620 }
1621 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1622 
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1623 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1624 {
1625 	return -ENOTSUPP;
1626 }
1627 
__bpf_copy_key(void __user * ukey,u64 key_size)1628 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1629 {
1630 	if (key_size)
1631 		return vmemdup_user(ukey, key_size);
1632 
1633 	if (ukey)
1634 		return ERR_PTR(-EINVAL);
1635 
1636 	return NULL;
1637 }
1638 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1639 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1640 {
1641 	if (key_size)
1642 		return kvmemdup_bpfptr(ukey, key_size);
1643 
1644 	if (!bpfptr_is_null(ukey))
1645 		return ERR_PTR(-EINVAL);
1646 
1647 	return NULL;
1648 }
1649 
1650 /* last field in 'union bpf_attr' used by this command */
1651 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1652 
map_lookup_elem(union bpf_attr * attr)1653 static int map_lookup_elem(union bpf_attr *attr)
1654 {
1655 	void __user *ukey = u64_to_user_ptr(attr->key);
1656 	void __user *uvalue = u64_to_user_ptr(attr->value);
1657 	struct bpf_map *map;
1658 	void *key, *value;
1659 	u32 value_size;
1660 	int err;
1661 
1662 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1663 		return -EINVAL;
1664 
1665 	if (attr->flags & ~BPF_F_LOCK)
1666 		return -EINVAL;
1667 
1668 	CLASS(fd, f)(attr->map_fd);
1669 	map = __bpf_map_get(f);
1670 	if (IS_ERR(map))
1671 		return PTR_ERR(map);
1672 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1673 		return -EPERM;
1674 
1675 	if ((attr->flags & BPF_F_LOCK) &&
1676 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
1677 		return -EINVAL;
1678 
1679 	key = __bpf_copy_key(ukey, map->key_size);
1680 	if (IS_ERR(key))
1681 		return PTR_ERR(key);
1682 
1683 	value_size = bpf_map_value_size(map);
1684 
1685 	err = -ENOMEM;
1686 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1687 	if (!value)
1688 		goto free_key;
1689 
1690 	if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1691 		if (copy_from_user(value, uvalue, value_size))
1692 			err = -EFAULT;
1693 		else
1694 			err = bpf_map_copy_value(map, key, value, attr->flags);
1695 		goto free_value;
1696 	}
1697 
1698 	err = bpf_map_copy_value(map, key, value, attr->flags);
1699 	if (err)
1700 		goto free_value;
1701 
1702 	err = -EFAULT;
1703 	if (copy_to_user(uvalue, value, value_size) != 0)
1704 		goto free_value;
1705 
1706 	err = 0;
1707 
1708 free_value:
1709 	kvfree(value);
1710 free_key:
1711 	kvfree(key);
1712 	return err;
1713 }
1714 
1715 
1716 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1717 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1718 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1719 {
1720 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1721 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1722 	struct bpf_map *map;
1723 	void *key, *value;
1724 	u32 value_size;
1725 	int err;
1726 
1727 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1728 		return -EINVAL;
1729 
1730 	CLASS(fd, f)(attr->map_fd);
1731 	map = __bpf_map_get(f);
1732 	if (IS_ERR(map))
1733 		return PTR_ERR(map);
1734 	bpf_map_write_active_inc(map);
1735 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1736 		err = -EPERM;
1737 		goto err_put;
1738 	}
1739 
1740 	if ((attr->flags & BPF_F_LOCK) &&
1741 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1742 		err = -EINVAL;
1743 		goto err_put;
1744 	}
1745 
1746 	key = ___bpf_copy_key(ukey, map->key_size);
1747 	if (IS_ERR(key)) {
1748 		err = PTR_ERR(key);
1749 		goto err_put;
1750 	}
1751 
1752 	value_size = bpf_map_value_size(map);
1753 	value = kvmemdup_bpfptr(uvalue, value_size);
1754 	if (IS_ERR(value)) {
1755 		err = PTR_ERR(value);
1756 		goto free_key;
1757 	}
1758 
1759 	err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1760 	if (!err)
1761 		maybe_wait_bpf_programs(map);
1762 
1763 	kvfree(value);
1764 free_key:
1765 	kvfree(key);
1766 err_put:
1767 	bpf_map_write_active_dec(map);
1768 	return err;
1769 }
1770 
1771 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1772 
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1773 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1774 {
1775 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1776 	struct bpf_map *map;
1777 	void *key;
1778 	int err;
1779 
1780 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1781 		return -EINVAL;
1782 
1783 	CLASS(fd, f)(attr->map_fd);
1784 	map = __bpf_map_get(f);
1785 	if (IS_ERR(map))
1786 		return PTR_ERR(map);
1787 	bpf_map_write_active_inc(map);
1788 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1789 		err = -EPERM;
1790 		goto err_put;
1791 	}
1792 
1793 	key = ___bpf_copy_key(ukey, map->key_size);
1794 	if (IS_ERR(key)) {
1795 		err = PTR_ERR(key);
1796 		goto err_put;
1797 	}
1798 
1799 	if (bpf_map_is_offloaded(map)) {
1800 		err = bpf_map_offload_delete_elem(map, key);
1801 		goto out;
1802 	} else if (IS_FD_PROG_ARRAY(map) ||
1803 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1804 		/* These maps require sleepable context */
1805 		err = map->ops->map_delete_elem(map, key);
1806 		goto out;
1807 	}
1808 
1809 	bpf_disable_instrumentation();
1810 	rcu_read_lock();
1811 	err = map->ops->map_delete_elem(map, key);
1812 	rcu_read_unlock();
1813 	bpf_enable_instrumentation();
1814 	if (!err)
1815 		maybe_wait_bpf_programs(map);
1816 out:
1817 	kvfree(key);
1818 err_put:
1819 	bpf_map_write_active_dec(map);
1820 	return err;
1821 }
1822 
1823 /* last field in 'union bpf_attr' used by this command */
1824 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1825 
map_get_next_key(union bpf_attr * attr)1826 static int map_get_next_key(union bpf_attr *attr)
1827 {
1828 	void __user *ukey = u64_to_user_ptr(attr->key);
1829 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1830 	struct bpf_map *map;
1831 	void *key, *next_key;
1832 	int err;
1833 
1834 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1835 		return -EINVAL;
1836 
1837 	CLASS(fd, f)(attr->map_fd);
1838 	map = __bpf_map_get(f);
1839 	if (IS_ERR(map))
1840 		return PTR_ERR(map);
1841 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1842 		return -EPERM;
1843 
1844 	if (ukey) {
1845 		key = __bpf_copy_key(ukey, map->key_size);
1846 		if (IS_ERR(key))
1847 			return PTR_ERR(key);
1848 	} else {
1849 		key = NULL;
1850 	}
1851 
1852 	err = -ENOMEM;
1853 	next_key = kvmalloc(map->key_size, GFP_USER);
1854 	if (!next_key)
1855 		goto free_key;
1856 
1857 	if (bpf_map_is_offloaded(map)) {
1858 		err = bpf_map_offload_get_next_key(map, key, next_key);
1859 		goto out;
1860 	}
1861 
1862 	rcu_read_lock();
1863 	err = map->ops->map_get_next_key(map, key, next_key);
1864 	rcu_read_unlock();
1865 out:
1866 	if (err)
1867 		goto free_next_key;
1868 
1869 	err = -EFAULT;
1870 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1871 		goto free_next_key;
1872 
1873 	err = 0;
1874 
1875 free_next_key:
1876 	kvfree(next_key);
1877 free_key:
1878 	kvfree(key);
1879 	return err;
1880 }
1881 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1882 int generic_map_delete_batch(struct bpf_map *map,
1883 			     const union bpf_attr *attr,
1884 			     union bpf_attr __user *uattr)
1885 {
1886 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1887 	u32 cp, max_count;
1888 	int err = 0;
1889 	void *key;
1890 
1891 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1892 		return -EINVAL;
1893 
1894 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1895 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1896 		return -EINVAL;
1897 	}
1898 
1899 	max_count = attr->batch.count;
1900 	if (!max_count)
1901 		return 0;
1902 
1903 	if (put_user(0, &uattr->batch.count))
1904 		return -EFAULT;
1905 
1906 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1907 	if (!key)
1908 		return -ENOMEM;
1909 
1910 	for (cp = 0; cp < max_count; cp++) {
1911 		err = -EFAULT;
1912 		if (copy_from_user(key, keys + cp * map->key_size,
1913 				   map->key_size))
1914 			break;
1915 
1916 		if (bpf_map_is_offloaded(map)) {
1917 			err = bpf_map_offload_delete_elem(map, key);
1918 			break;
1919 		}
1920 
1921 		bpf_disable_instrumentation();
1922 		rcu_read_lock();
1923 		err = map->ops->map_delete_elem(map, key);
1924 		rcu_read_unlock();
1925 		bpf_enable_instrumentation();
1926 		if (err)
1927 			break;
1928 		cond_resched();
1929 	}
1930 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1931 		err = -EFAULT;
1932 
1933 	kvfree(key);
1934 
1935 	return err;
1936 }
1937 
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1938 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1939 			     const union bpf_attr *attr,
1940 			     union bpf_attr __user *uattr)
1941 {
1942 	void __user *values = u64_to_user_ptr(attr->batch.values);
1943 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1944 	u32 value_size, cp, max_count;
1945 	void *key, *value;
1946 	int err = 0;
1947 
1948 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1949 		return -EINVAL;
1950 
1951 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1952 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1953 		return -EINVAL;
1954 	}
1955 
1956 	value_size = bpf_map_value_size(map);
1957 
1958 	max_count = attr->batch.count;
1959 	if (!max_count)
1960 		return 0;
1961 
1962 	if (put_user(0, &uattr->batch.count))
1963 		return -EFAULT;
1964 
1965 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1966 	if (!key)
1967 		return -ENOMEM;
1968 
1969 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1970 	if (!value) {
1971 		kvfree(key);
1972 		return -ENOMEM;
1973 	}
1974 
1975 	for (cp = 0; cp < max_count; cp++) {
1976 		err = -EFAULT;
1977 		if (copy_from_user(key, keys + cp * map->key_size,
1978 		    map->key_size) ||
1979 		    copy_from_user(value, values + cp * value_size, value_size))
1980 			break;
1981 
1982 		err = bpf_map_update_value(map, map_file, key, value,
1983 					   attr->batch.elem_flags);
1984 
1985 		if (err)
1986 			break;
1987 		cond_resched();
1988 	}
1989 
1990 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1991 		err = -EFAULT;
1992 
1993 	kvfree(value);
1994 	kvfree(key);
1995 
1996 	return err;
1997 }
1998 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1999 int generic_map_lookup_batch(struct bpf_map *map,
2000 				    const union bpf_attr *attr,
2001 				    union bpf_attr __user *uattr)
2002 {
2003 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
2004 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
2005 	void __user *values = u64_to_user_ptr(attr->batch.values);
2006 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
2007 	void *buf, *buf_prevkey, *prev_key, *key, *value;
2008 	u32 value_size, cp, max_count;
2009 	int err;
2010 
2011 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
2012 		return -EINVAL;
2013 
2014 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
2015 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
2016 		return -EINVAL;
2017 
2018 	value_size = bpf_map_value_size(map);
2019 
2020 	max_count = attr->batch.count;
2021 	if (!max_count)
2022 		return 0;
2023 
2024 	if (put_user(0, &uattr->batch.count))
2025 		return -EFAULT;
2026 
2027 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2028 	if (!buf_prevkey)
2029 		return -ENOMEM;
2030 
2031 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2032 	if (!buf) {
2033 		kvfree(buf_prevkey);
2034 		return -ENOMEM;
2035 	}
2036 
2037 	err = -EFAULT;
2038 	prev_key = NULL;
2039 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2040 		goto free_buf;
2041 	key = buf;
2042 	value = key + map->key_size;
2043 	if (ubatch)
2044 		prev_key = buf_prevkey;
2045 
2046 	for (cp = 0; cp < max_count;) {
2047 		rcu_read_lock();
2048 		err = map->ops->map_get_next_key(map, prev_key, key);
2049 		rcu_read_unlock();
2050 		if (err)
2051 			break;
2052 		err = bpf_map_copy_value(map, key, value,
2053 					 attr->batch.elem_flags);
2054 
2055 		if (err == -ENOENT)
2056 			goto next_key;
2057 
2058 		if (err)
2059 			goto free_buf;
2060 
2061 		if (copy_to_user(keys + cp * map->key_size, key,
2062 				 map->key_size)) {
2063 			err = -EFAULT;
2064 			goto free_buf;
2065 		}
2066 		if (copy_to_user(values + cp * value_size, value, value_size)) {
2067 			err = -EFAULT;
2068 			goto free_buf;
2069 		}
2070 
2071 		cp++;
2072 next_key:
2073 		if (!prev_key)
2074 			prev_key = buf_prevkey;
2075 
2076 		swap(prev_key, key);
2077 		cond_resched();
2078 	}
2079 
2080 	if (err == -EFAULT)
2081 		goto free_buf;
2082 
2083 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2084 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2085 		err = -EFAULT;
2086 
2087 free_buf:
2088 	kvfree(buf_prevkey);
2089 	kvfree(buf);
2090 	return err;
2091 }
2092 
2093 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2094 
map_lookup_and_delete_elem(union bpf_attr * attr)2095 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2096 {
2097 	void __user *ukey = u64_to_user_ptr(attr->key);
2098 	void __user *uvalue = u64_to_user_ptr(attr->value);
2099 	struct bpf_map *map;
2100 	void *key, *value;
2101 	u32 value_size;
2102 	int err;
2103 
2104 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2105 		return -EINVAL;
2106 
2107 	if (attr->flags & ~BPF_F_LOCK)
2108 		return -EINVAL;
2109 
2110 	CLASS(fd, f)(attr->map_fd);
2111 	map = __bpf_map_get(f);
2112 	if (IS_ERR(map))
2113 		return PTR_ERR(map);
2114 	bpf_map_write_active_inc(map);
2115 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2116 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2117 		err = -EPERM;
2118 		goto err_put;
2119 	}
2120 
2121 	if (attr->flags &&
2122 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
2123 	     map->map_type == BPF_MAP_TYPE_STACK)) {
2124 		err = -EINVAL;
2125 		goto err_put;
2126 	}
2127 
2128 	if ((attr->flags & BPF_F_LOCK) &&
2129 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2130 		err = -EINVAL;
2131 		goto err_put;
2132 	}
2133 
2134 	key = __bpf_copy_key(ukey, map->key_size);
2135 	if (IS_ERR(key)) {
2136 		err = PTR_ERR(key);
2137 		goto err_put;
2138 	}
2139 
2140 	value_size = bpf_map_value_size(map);
2141 
2142 	err = -ENOMEM;
2143 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2144 	if (!value)
2145 		goto free_key;
2146 
2147 	err = -ENOTSUPP;
2148 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2149 	    map->map_type == BPF_MAP_TYPE_STACK) {
2150 		err = map->ops->map_pop_elem(map, value);
2151 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
2152 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2153 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2154 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
2155 		if (!bpf_map_is_offloaded(map)) {
2156 			bpf_disable_instrumentation();
2157 			rcu_read_lock();
2158 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2159 			rcu_read_unlock();
2160 			bpf_enable_instrumentation();
2161 		}
2162 	}
2163 
2164 	if (err)
2165 		goto free_value;
2166 
2167 	if (copy_to_user(uvalue, value, value_size) != 0) {
2168 		err = -EFAULT;
2169 		goto free_value;
2170 	}
2171 
2172 	err = 0;
2173 
2174 free_value:
2175 	kvfree(value);
2176 free_key:
2177 	kvfree(key);
2178 err_put:
2179 	bpf_map_write_active_dec(map);
2180 	return err;
2181 }
2182 
2183 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2184 
map_freeze(const union bpf_attr * attr)2185 static int map_freeze(const union bpf_attr *attr)
2186 {
2187 	int err = 0;
2188 	struct bpf_map *map;
2189 
2190 	if (CHECK_ATTR(BPF_MAP_FREEZE))
2191 		return -EINVAL;
2192 
2193 	CLASS(fd, f)(attr->map_fd);
2194 	map = __bpf_map_get(f);
2195 	if (IS_ERR(map))
2196 		return PTR_ERR(map);
2197 
2198 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2199 		return -ENOTSUPP;
2200 
2201 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2202 		return -EPERM;
2203 
2204 	mutex_lock(&map->freeze_mutex);
2205 	if (bpf_map_write_active(map)) {
2206 		err = -EBUSY;
2207 		goto err_put;
2208 	}
2209 	if (READ_ONCE(map->frozen)) {
2210 		err = -EBUSY;
2211 		goto err_put;
2212 	}
2213 
2214 	WRITE_ONCE(map->frozen, true);
2215 err_put:
2216 	mutex_unlock(&map->freeze_mutex);
2217 	return err;
2218 }
2219 
2220 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2221 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2222 	[_id] = & _name ## _prog_ops,
2223 #define BPF_MAP_TYPE(_id, _ops)
2224 #define BPF_LINK_TYPE(_id, _name)
2225 #include <linux/bpf_types.h>
2226 #undef BPF_PROG_TYPE
2227 #undef BPF_MAP_TYPE
2228 #undef BPF_LINK_TYPE
2229 };
2230 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2231 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2232 {
2233 	const struct bpf_prog_ops *ops;
2234 
2235 	if (type >= ARRAY_SIZE(bpf_prog_types))
2236 		return -EINVAL;
2237 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2238 	ops = bpf_prog_types[type];
2239 	if (!ops)
2240 		return -EINVAL;
2241 
2242 	if (!bpf_prog_is_offloaded(prog->aux))
2243 		prog->aux->ops = ops;
2244 	else
2245 		prog->aux->ops = &bpf_offload_prog_ops;
2246 	prog->type = type;
2247 	return 0;
2248 }
2249 
2250 enum bpf_audit {
2251 	BPF_AUDIT_LOAD,
2252 	BPF_AUDIT_UNLOAD,
2253 	BPF_AUDIT_MAX,
2254 };
2255 
2256 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2257 	[BPF_AUDIT_LOAD]   = "LOAD",
2258 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
2259 };
2260 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2261 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2262 {
2263 	struct audit_context *ctx = NULL;
2264 	struct audit_buffer *ab;
2265 
2266 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2267 		return;
2268 	if (audit_enabled == AUDIT_OFF)
2269 		return;
2270 	if (!in_irq() && !irqs_disabled())
2271 		ctx = audit_context();
2272 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2273 	if (unlikely(!ab))
2274 		return;
2275 	audit_log_format(ab, "prog-id=%u op=%s",
2276 			 prog->aux->id, bpf_audit_str[op]);
2277 	audit_log_end(ab);
2278 }
2279 
bpf_prog_alloc_id(struct bpf_prog * prog)2280 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2281 {
2282 	int id;
2283 
2284 	idr_preload(GFP_KERNEL);
2285 	spin_lock_bh(&prog_idr_lock);
2286 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2287 	if (id > 0)
2288 		prog->aux->id = id;
2289 	spin_unlock_bh(&prog_idr_lock);
2290 	idr_preload_end();
2291 
2292 	/* id is in [1, INT_MAX) */
2293 	if (WARN_ON_ONCE(!id))
2294 		return -ENOSPC;
2295 
2296 	return id > 0 ? 0 : id;
2297 }
2298 
bpf_prog_free_id(struct bpf_prog * prog)2299 void bpf_prog_free_id(struct bpf_prog *prog)
2300 {
2301 	unsigned long flags;
2302 
2303 	/* cBPF to eBPF migrations are currently not in the idr store.
2304 	 * Offloaded programs are removed from the store when their device
2305 	 * disappears - even if someone grabs an fd to them they are unusable,
2306 	 * simply waiting for refcnt to drop to be freed.
2307 	 */
2308 	if (!prog->aux->id)
2309 		return;
2310 
2311 	spin_lock_irqsave(&prog_idr_lock, flags);
2312 	idr_remove(&prog_idr, prog->aux->id);
2313 	prog->aux->id = 0;
2314 	spin_unlock_irqrestore(&prog_idr_lock, flags);
2315 }
2316 
__bpf_prog_put_rcu(struct rcu_head * rcu)2317 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2318 {
2319 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2320 
2321 	kvfree(aux->func_info);
2322 	kfree(aux->func_info_aux);
2323 	free_uid(aux->user);
2324 	security_bpf_prog_free(aux->prog);
2325 	bpf_prog_free(aux->prog);
2326 }
2327 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2328 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2329 {
2330 	bpf_prog_kallsyms_del_all(prog);
2331 	btf_put(prog->aux->btf);
2332 	module_put(prog->aux->mod);
2333 	kvfree(prog->aux->jited_linfo);
2334 	kvfree(prog->aux->linfo);
2335 	kfree(prog->aux->kfunc_tab);
2336 	kfree(prog->aux->ctx_arg_info);
2337 	if (prog->aux->attach_btf)
2338 		btf_put(prog->aux->attach_btf);
2339 
2340 	if (deferred) {
2341 		if (prog->sleepable)
2342 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2343 		else
2344 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2345 	} else {
2346 		__bpf_prog_put_rcu(&prog->aux->rcu);
2347 	}
2348 }
2349 
bpf_prog_put_deferred(struct work_struct * work)2350 static void bpf_prog_put_deferred(struct work_struct *work)
2351 {
2352 	struct bpf_prog_aux *aux;
2353 	struct bpf_prog *prog;
2354 
2355 	aux = container_of(work, struct bpf_prog_aux, work);
2356 	prog = aux->prog;
2357 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2358 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2359 	bpf_prog_free_id(prog);
2360 	__bpf_prog_put_noref(prog, true);
2361 }
2362 
__bpf_prog_put(struct bpf_prog * prog)2363 static void __bpf_prog_put(struct bpf_prog *prog)
2364 {
2365 	struct bpf_prog_aux *aux = prog->aux;
2366 
2367 	if (atomic64_dec_and_test(&aux->refcnt)) {
2368 		if (in_irq() || irqs_disabled()) {
2369 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
2370 			schedule_work(&aux->work);
2371 		} else {
2372 			bpf_prog_put_deferred(&aux->work);
2373 		}
2374 	}
2375 }
2376 
bpf_prog_put(struct bpf_prog * prog)2377 void bpf_prog_put(struct bpf_prog *prog)
2378 {
2379 	__bpf_prog_put(prog);
2380 }
2381 EXPORT_SYMBOL_GPL(bpf_prog_put);
2382 
bpf_prog_release(struct inode * inode,struct file * filp)2383 static int bpf_prog_release(struct inode *inode, struct file *filp)
2384 {
2385 	struct bpf_prog *prog = filp->private_data;
2386 
2387 	bpf_prog_put(prog);
2388 	return 0;
2389 }
2390 
2391 struct bpf_prog_kstats {
2392 	u64 nsecs;
2393 	u64 cnt;
2394 	u64 misses;
2395 };
2396 
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2397 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2398 {
2399 	struct bpf_prog_stats *stats;
2400 	unsigned int flags;
2401 
2402 	stats = this_cpu_ptr(prog->stats);
2403 	flags = u64_stats_update_begin_irqsave(&stats->syncp);
2404 	u64_stats_inc(&stats->misses);
2405 	u64_stats_update_end_irqrestore(&stats->syncp, flags);
2406 }
2407 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2408 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2409 			       struct bpf_prog_kstats *stats)
2410 {
2411 	u64 nsecs = 0, cnt = 0, misses = 0;
2412 	int cpu;
2413 
2414 	for_each_possible_cpu(cpu) {
2415 		const struct bpf_prog_stats *st;
2416 		unsigned int start;
2417 		u64 tnsecs, tcnt, tmisses;
2418 
2419 		st = per_cpu_ptr(prog->stats, cpu);
2420 		do {
2421 			start = u64_stats_fetch_begin(&st->syncp);
2422 			tnsecs = u64_stats_read(&st->nsecs);
2423 			tcnt = u64_stats_read(&st->cnt);
2424 			tmisses = u64_stats_read(&st->misses);
2425 		} while (u64_stats_fetch_retry(&st->syncp, start));
2426 		nsecs += tnsecs;
2427 		cnt += tcnt;
2428 		misses += tmisses;
2429 	}
2430 	stats->nsecs = nsecs;
2431 	stats->cnt = cnt;
2432 	stats->misses = misses;
2433 }
2434 
2435 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2436 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2437 {
2438 	const struct bpf_prog *prog = filp->private_data;
2439 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2440 	struct bpf_prog_kstats stats;
2441 
2442 	bpf_prog_get_stats(prog, &stats);
2443 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2444 	seq_printf(m,
2445 		   "prog_type:\t%u\n"
2446 		   "prog_jited:\t%u\n"
2447 		   "prog_tag:\t%s\n"
2448 		   "memlock:\t%llu\n"
2449 		   "prog_id:\t%u\n"
2450 		   "run_time_ns:\t%llu\n"
2451 		   "run_cnt:\t%llu\n"
2452 		   "recursion_misses:\t%llu\n"
2453 		   "verified_insns:\t%u\n",
2454 		   prog->type,
2455 		   prog->jited,
2456 		   prog_tag,
2457 		   prog->pages * 1ULL << PAGE_SHIFT,
2458 		   prog->aux->id,
2459 		   stats.nsecs,
2460 		   stats.cnt,
2461 		   stats.misses,
2462 		   prog->aux->verified_insns);
2463 }
2464 #endif
2465 
2466 const struct file_operations bpf_prog_fops = {
2467 #ifdef CONFIG_PROC_FS
2468 	.show_fdinfo	= bpf_prog_show_fdinfo,
2469 #endif
2470 	.release	= bpf_prog_release,
2471 	.read		= bpf_dummy_read,
2472 	.write		= bpf_dummy_write,
2473 };
2474 
bpf_prog_new_fd(struct bpf_prog * prog)2475 int bpf_prog_new_fd(struct bpf_prog *prog)
2476 {
2477 	int ret;
2478 
2479 	ret = security_bpf_prog(prog);
2480 	if (ret < 0)
2481 		return ret;
2482 
2483 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2484 				O_RDWR | O_CLOEXEC);
2485 }
2486 
bpf_prog_add(struct bpf_prog * prog,int i)2487 void bpf_prog_add(struct bpf_prog *prog, int i)
2488 {
2489 	atomic64_add(i, &prog->aux->refcnt);
2490 }
2491 EXPORT_SYMBOL_GPL(bpf_prog_add);
2492 
bpf_prog_sub(struct bpf_prog * prog,int i)2493 void bpf_prog_sub(struct bpf_prog *prog, int i)
2494 {
2495 	/* Only to be used for undoing previous bpf_prog_add() in some
2496 	 * error path. We still know that another entity in our call
2497 	 * path holds a reference to the program, thus atomic_sub() can
2498 	 * be safely used in such cases!
2499 	 */
2500 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2501 }
2502 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2503 
bpf_prog_inc(struct bpf_prog * prog)2504 void bpf_prog_inc(struct bpf_prog *prog)
2505 {
2506 	atomic64_inc(&prog->aux->refcnt);
2507 }
2508 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2509 
2510 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2511 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2512 {
2513 	int refold;
2514 
2515 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2516 
2517 	if (!refold)
2518 		return ERR_PTR(-ENOENT);
2519 
2520 	return prog;
2521 }
2522 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2523 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2524 bool bpf_prog_get_ok(struct bpf_prog *prog,
2525 			    enum bpf_prog_type *attach_type, bool attach_drv)
2526 {
2527 	/* not an attachment, just a refcount inc, always allow */
2528 	if (!attach_type)
2529 		return true;
2530 
2531 	if (prog->type != *attach_type)
2532 		return false;
2533 	if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2534 		return false;
2535 
2536 	return true;
2537 }
2538 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2539 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2540 				       bool attach_drv)
2541 {
2542 	CLASS(fd, f)(ufd);
2543 	struct bpf_prog *prog;
2544 
2545 	if (fd_empty(f))
2546 		return ERR_PTR(-EBADF);
2547 	if (fd_file(f)->f_op != &bpf_prog_fops)
2548 		return ERR_PTR(-EINVAL);
2549 
2550 	prog = fd_file(f)->private_data;
2551 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2552 		return ERR_PTR(-EINVAL);
2553 
2554 	bpf_prog_inc(prog);
2555 	return prog;
2556 }
2557 
bpf_prog_get(u32 ufd)2558 struct bpf_prog *bpf_prog_get(u32 ufd)
2559 {
2560 	return __bpf_prog_get(ufd, NULL, false);
2561 }
2562 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2563 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2564 				       bool attach_drv)
2565 {
2566 	return __bpf_prog_get(ufd, &type, attach_drv);
2567 }
2568 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2569 
2570 /* Initially all BPF programs could be loaded w/o specifying
2571  * expected_attach_type. Later for some of them specifying expected_attach_type
2572  * at load time became required so that program could be validated properly.
2573  * Programs of types that are allowed to be loaded both w/ and w/o (for
2574  * backward compatibility) expected_attach_type, should have the default attach
2575  * type assigned to expected_attach_type for the latter case, so that it can be
2576  * validated later at attach time.
2577  *
2578  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2579  * prog type requires it but has some attach types that have to be backward
2580  * compatible.
2581  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2582 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2583 {
2584 	switch (attr->prog_type) {
2585 	case BPF_PROG_TYPE_CGROUP_SOCK:
2586 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2587 		 * exist so checking for non-zero is the way to go here.
2588 		 */
2589 		if (!attr->expected_attach_type)
2590 			attr->expected_attach_type =
2591 				BPF_CGROUP_INET_SOCK_CREATE;
2592 		break;
2593 	case BPF_PROG_TYPE_SK_REUSEPORT:
2594 		if (!attr->expected_attach_type)
2595 			attr->expected_attach_type =
2596 				BPF_SK_REUSEPORT_SELECT;
2597 		break;
2598 	}
2599 }
2600 
2601 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)2602 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2603 			   enum bpf_attach_type expected_attach_type,
2604 			   struct btf *attach_btf, u32 btf_id,
2605 			   struct bpf_prog *dst_prog)
2606 {
2607 	if (btf_id) {
2608 		if (btf_id > BTF_MAX_TYPE)
2609 			return -EINVAL;
2610 
2611 		if (!attach_btf && !dst_prog)
2612 			return -EINVAL;
2613 
2614 		switch (prog_type) {
2615 		case BPF_PROG_TYPE_TRACING:
2616 		case BPF_PROG_TYPE_LSM:
2617 		case BPF_PROG_TYPE_STRUCT_OPS:
2618 		case BPF_PROG_TYPE_EXT:
2619 			break;
2620 		default:
2621 			return -EINVAL;
2622 		}
2623 	}
2624 
2625 	if (attach_btf && (!btf_id || dst_prog))
2626 		return -EINVAL;
2627 
2628 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2629 	    prog_type != BPF_PROG_TYPE_EXT)
2630 		return -EINVAL;
2631 
2632 	switch (prog_type) {
2633 	case BPF_PROG_TYPE_CGROUP_SOCK:
2634 		switch (expected_attach_type) {
2635 		case BPF_CGROUP_INET_SOCK_CREATE:
2636 		case BPF_CGROUP_INET_SOCK_RELEASE:
2637 		case BPF_CGROUP_INET4_POST_BIND:
2638 		case BPF_CGROUP_INET6_POST_BIND:
2639 			return 0;
2640 		default:
2641 			return -EINVAL;
2642 		}
2643 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2644 		switch (expected_attach_type) {
2645 		case BPF_CGROUP_INET4_BIND:
2646 		case BPF_CGROUP_INET6_BIND:
2647 		case BPF_CGROUP_INET4_CONNECT:
2648 		case BPF_CGROUP_INET6_CONNECT:
2649 		case BPF_CGROUP_UNIX_CONNECT:
2650 		case BPF_CGROUP_INET4_GETPEERNAME:
2651 		case BPF_CGROUP_INET6_GETPEERNAME:
2652 		case BPF_CGROUP_UNIX_GETPEERNAME:
2653 		case BPF_CGROUP_INET4_GETSOCKNAME:
2654 		case BPF_CGROUP_INET6_GETSOCKNAME:
2655 		case BPF_CGROUP_UNIX_GETSOCKNAME:
2656 		case BPF_CGROUP_UDP4_SENDMSG:
2657 		case BPF_CGROUP_UDP6_SENDMSG:
2658 		case BPF_CGROUP_UNIX_SENDMSG:
2659 		case BPF_CGROUP_UDP4_RECVMSG:
2660 		case BPF_CGROUP_UDP6_RECVMSG:
2661 		case BPF_CGROUP_UNIX_RECVMSG:
2662 			return 0;
2663 		default:
2664 			return -EINVAL;
2665 		}
2666 	case BPF_PROG_TYPE_CGROUP_SKB:
2667 		switch (expected_attach_type) {
2668 		case BPF_CGROUP_INET_INGRESS:
2669 		case BPF_CGROUP_INET_EGRESS:
2670 			return 0;
2671 		default:
2672 			return -EINVAL;
2673 		}
2674 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2675 		switch (expected_attach_type) {
2676 		case BPF_CGROUP_SETSOCKOPT:
2677 		case BPF_CGROUP_GETSOCKOPT:
2678 			return 0;
2679 		default:
2680 			return -EINVAL;
2681 		}
2682 	case BPF_PROG_TYPE_SK_LOOKUP:
2683 		if (expected_attach_type == BPF_SK_LOOKUP)
2684 			return 0;
2685 		return -EINVAL;
2686 	case BPF_PROG_TYPE_SK_REUSEPORT:
2687 		switch (expected_attach_type) {
2688 		case BPF_SK_REUSEPORT_SELECT:
2689 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2690 			return 0;
2691 		default:
2692 			return -EINVAL;
2693 		}
2694 	case BPF_PROG_TYPE_NETFILTER:
2695 		if (expected_attach_type == BPF_NETFILTER)
2696 			return 0;
2697 		return -EINVAL;
2698 	case BPF_PROG_TYPE_SYSCALL:
2699 	case BPF_PROG_TYPE_EXT:
2700 		if (expected_attach_type)
2701 			return -EINVAL;
2702 		fallthrough;
2703 	default:
2704 		return 0;
2705 	}
2706 }
2707 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2708 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2709 {
2710 	switch (prog_type) {
2711 	case BPF_PROG_TYPE_SCHED_CLS:
2712 	case BPF_PROG_TYPE_SCHED_ACT:
2713 	case BPF_PROG_TYPE_XDP:
2714 	case BPF_PROG_TYPE_LWT_IN:
2715 	case BPF_PROG_TYPE_LWT_OUT:
2716 	case BPF_PROG_TYPE_LWT_XMIT:
2717 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2718 	case BPF_PROG_TYPE_SK_SKB:
2719 	case BPF_PROG_TYPE_SK_MSG:
2720 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2721 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2722 	case BPF_PROG_TYPE_CGROUP_SOCK:
2723 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2724 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2725 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2726 	case BPF_PROG_TYPE_SOCK_OPS:
2727 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2728 	case BPF_PROG_TYPE_NETFILTER:
2729 		return true;
2730 	case BPF_PROG_TYPE_CGROUP_SKB:
2731 		/* always unpriv */
2732 	case BPF_PROG_TYPE_SK_REUSEPORT:
2733 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2734 	default:
2735 		return false;
2736 	}
2737 }
2738 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2739 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2740 {
2741 	switch (prog_type) {
2742 	case BPF_PROG_TYPE_KPROBE:
2743 	case BPF_PROG_TYPE_TRACEPOINT:
2744 	case BPF_PROG_TYPE_PERF_EVENT:
2745 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2746 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2747 	case BPF_PROG_TYPE_TRACING:
2748 	case BPF_PROG_TYPE_LSM:
2749 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2750 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2751 		return true;
2752 	default:
2753 		return false;
2754 	}
2755 }
2756 
2757 /* last field in 'union bpf_attr' used by this command */
2758 #define BPF_PROG_LOAD_LAST_FIELD fd_array_cnt
2759 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2760 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2761 {
2762 	enum bpf_prog_type type = attr->prog_type;
2763 	struct bpf_prog *prog, *dst_prog = NULL;
2764 	struct btf *attach_btf = NULL;
2765 	struct bpf_token *token = NULL;
2766 	bool bpf_cap;
2767 	int err;
2768 	char license[128];
2769 
2770 	if (CHECK_ATTR(BPF_PROG_LOAD))
2771 		return -EINVAL;
2772 
2773 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2774 				 BPF_F_ANY_ALIGNMENT |
2775 				 BPF_F_TEST_STATE_FREQ |
2776 				 BPF_F_SLEEPABLE |
2777 				 BPF_F_TEST_RND_HI32 |
2778 				 BPF_F_XDP_HAS_FRAGS |
2779 				 BPF_F_XDP_DEV_BOUND_ONLY |
2780 				 BPF_F_TEST_REG_INVARIANTS |
2781 				 BPF_F_TOKEN_FD))
2782 		return -EINVAL;
2783 
2784 	bpf_prog_load_fixup_attach_type(attr);
2785 
2786 	if (attr->prog_flags & BPF_F_TOKEN_FD) {
2787 		token = bpf_token_get_from_fd(attr->prog_token_fd);
2788 		if (IS_ERR(token))
2789 			return PTR_ERR(token);
2790 		/* if current token doesn't grant prog loading permissions,
2791 		 * then we can't use this token, so ignore it and rely on
2792 		 * system-wide capabilities checks
2793 		 */
2794 		if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2795 		    !bpf_token_allow_prog_type(token, attr->prog_type,
2796 					       attr->expected_attach_type)) {
2797 			bpf_token_put(token);
2798 			token = NULL;
2799 		}
2800 	}
2801 
2802 	bpf_cap = bpf_token_capable(token, CAP_BPF);
2803 	err = -EPERM;
2804 
2805 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2806 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2807 	    !bpf_cap)
2808 		goto put_token;
2809 
2810 	/* Intent here is for unprivileged_bpf_disabled to block BPF program
2811 	 * creation for unprivileged users; other actions depend
2812 	 * on fd availability and access to bpffs, so are dependent on
2813 	 * object creation success. Even with unprivileged BPF disabled,
2814 	 * capability checks are still carried out for these
2815 	 * and other operations.
2816 	 */
2817 	if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2818 		goto put_token;
2819 
2820 	if (attr->insn_cnt == 0 ||
2821 	    attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2822 		err = -E2BIG;
2823 		goto put_token;
2824 	}
2825 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2826 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2827 	    !bpf_cap)
2828 		goto put_token;
2829 
2830 	if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2831 		goto put_token;
2832 	if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2833 		goto put_token;
2834 
2835 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2836 	 * or btf, we need to check which one it is
2837 	 */
2838 	if (attr->attach_prog_fd) {
2839 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2840 		if (IS_ERR(dst_prog)) {
2841 			dst_prog = NULL;
2842 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2843 			if (IS_ERR(attach_btf)) {
2844 				err = -EINVAL;
2845 				goto put_token;
2846 			}
2847 			if (!btf_is_kernel(attach_btf)) {
2848 				/* attaching through specifying bpf_prog's BTF
2849 				 * objects directly might be supported eventually
2850 				 */
2851 				btf_put(attach_btf);
2852 				err = -ENOTSUPP;
2853 				goto put_token;
2854 			}
2855 		}
2856 	} else if (attr->attach_btf_id) {
2857 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2858 		attach_btf = bpf_get_btf_vmlinux();
2859 		if (IS_ERR(attach_btf)) {
2860 			err = PTR_ERR(attach_btf);
2861 			goto put_token;
2862 		}
2863 		if (!attach_btf) {
2864 			err = -EINVAL;
2865 			goto put_token;
2866 		}
2867 		btf_get(attach_btf);
2868 	}
2869 
2870 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2871 				       attach_btf, attr->attach_btf_id,
2872 				       dst_prog)) {
2873 		if (dst_prog)
2874 			bpf_prog_put(dst_prog);
2875 		if (attach_btf)
2876 			btf_put(attach_btf);
2877 		err = -EINVAL;
2878 		goto put_token;
2879 	}
2880 
2881 	/* plain bpf_prog allocation */
2882 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2883 	if (!prog) {
2884 		if (dst_prog)
2885 			bpf_prog_put(dst_prog);
2886 		if (attach_btf)
2887 			btf_put(attach_btf);
2888 		err = -EINVAL;
2889 		goto put_token;
2890 	}
2891 
2892 	prog->expected_attach_type = attr->expected_attach_type;
2893 	prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
2894 	prog->aux->attach_btf = attach_btf;
2895 	prog->aux->attach_btf_id = attr->attach_btf_id;
2896 	prog->aux->dst_prog = dst_prog;
2897 	prog->aux->dev_bound = !!attr->prog_ifindex;
2898 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
2899 
2900 	/* move token into prog->aux, reuse taken refcnt */
2901 	prog->aux->token = token;
2902 	token = NULL;
2903 
2904 	prog->aux->user = get_current_user();
2905 	prog->len = attr->insn_cnt;
2906 
2907 	err = -EFAULT;
2908 	if (copy_from_bpfptr(prog->insns,
2909 			     make_bpfptr(attr->insns, uattr.is_kernel),
2910 			     bpf_prog_insn_size(prog)) != 0)
2911 		goto free_prog;
2912 	/* copy eBPF program license from user space */
2913 	if (strncpy_from_bpfptr(license,
2914 				make_bpfptr(attr->license, uattr.is_kernel),
2915 				sizeof(license) - 1) < 0)
2916 		goto free_prog;
2917 	license[sizeof(license) - 1] = 0;
2918 
2919 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
2920 	prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
2921 
2922 	prog->orig_prog = NULL;
2923 	prog->jited = 0;
2924 
2925 	atomic64_set(&prog->aux->refcnt, 1);
2926 
2927 	if (bpf_prog_is_dev_bound(prog->aux)) {
2928 		err = bpf_prog_dev_bound_init(prog, attr);
2929 		if (err)
2930 			goto free_prog;
2931 	}
2932 
2933 	if (type == BPF_PROG_TYPE_EXT && dst_prog &&
2934 	    bpf_prog_is_dev_bound(dst_prog->aux)) {
2935 		err = bpf_prog_dev_bound_inherit(prog, dst_prog);
2936 		if (err)
2937 			goto free_prog;
2938 	}
2939 
2940 	/*
2941 	 * Bookkeeping for managing the program attachment chain.
2942 	 *
2943 	 * It might be tempting to set attach_tracing_prog flag at the attachment
2944 	 * time, but this will not prevent from loading bunch of tracing prog
2945 	 * first, then attach them one to another.
2946 	 *
2947 	 * The flag attach_tracing_prog is set for the whole program lifecycle, and
2948 	 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
2949 	 * programs cannot change attachment target.
2950 	 */
2951 	if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
2952 	    dst_prog->type == BPF_PROG_TYPE_TRACING) {
2953 		prog->aux->attach_tracing_prog = true;
2954 	}
2955 
2956 	/* find program type: socket_filter vs tracing_filter */
2957 	err = find_prog_type(type, prog);
2958 	if (err < 0)
2959 		goto free_prog;
2960 
2961 	prog->aux->load_time = ktime_get_boottime_ns();
2962 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2963 			       sizeof(attr->prog_name));
2964 	if (err < 0)
2965 		goto free_prog;
2966 
2967 	err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel);
2968 	if (err)
2969 		goto free_prog_sec;
2970 
2971 	/* run eBPF verifier */
2972 	err = bpf_check(&prog, attr, uattr, uattr_size);
2973 	if (err < 0)
2974 		goto free_used_maps;
2975 
2976 	prog = bpf_prog_select_runtime(prog, &err);
2977 	if (err < 0)
2978 		goto free_used_maps;
2979 
2980 	err = bpf_prog_alloc_id(prog);
2981 	if (err)
2982 		goto free_used_maps;
2983 
2984 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
2985 	 * effectively publicly exposed. However, retrieving via
2986 	 * bpf_prog_get_fd_by_id() will take another reference,
2987 	 * therefore it cannot be gone underneath us.
2988 	 *
2989 	 * Only for the time /after/ successful bpf_prog_new_fd()
2990 	 * and before returning to userspace, we might just hold
2991 	 * one reference and any parallel close on that fd could
2992 	 * rip everything out. Hence, below notifications must
2993 	 * happen before bpf_prog_new_fd().
2994 	 *
2995 	 * Also, any failure handling from this point onwards must
2996 	 * be using bpf_prog_put() given the program is exposed.
2997 	 */
2998 	bpf_prog_kallsyms_add(prog);
2999 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
3000 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3001 
3002 	err = bpf_prog_new_fd(prog);
3003 	if (err < 0)
3004 		bpf_prog_put(prog);
3005 	return err;
3006 
3007 free_used_maps:
3008 	/* In case we have subprogs, we need to wait for a grace
3009 	 * period before we can tear down JIT memory since symbols
3010 	 * are already exposed under kallsyms.
3011 	 */
3012 	__bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3013 	return err;
3014 
3015 free_prog_sec:
3016 	security_bpf_prog_free(prog);
3017 free_prog:
3018 	free_uid(prog->aux->user);
3019 	if (prog->aux->attach_btf)
3020 		btf_put(prog->aux->attach_btf);
3021 	bpf_prog_free(prog);
3022 put_token:
3023 	bpf_token_put(token);
3024 	return err;
3025 }
3026 
3027 #define BPF_OBJ_LAST_FIELD path_fd
3028 
bpf_obj_pin(const union bpf_attr * attr)3029 static int bpf_obj_pin(const union bpf_attr *attr)
3030 {
3031 	int path_fd;
3032 
3033 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3034 		return -EINVAL;
3035 
3036 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3037 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3038 		return -EINVAL;
3039 
3040 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3041 	return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3042 				u64_to_user_ptr(attr->pathname));
3043 }
3044 
bpf_obj_get(const union bpf_attr * attr)3045 static int bpf_obj_get(const union bpf_attr *attr)
3046 {
3047 	int path_fd;
3048 
3049 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3050 	    attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3051 		return -EINVAL;
3052 
3053 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3054 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3055 		return -EINVAL;
3056 
3057 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3058 	return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3059 				attr->file_flags);
3060 }
3061 
3062 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3063  * "sleepable" semantics, which normally would mean that BPF link's attach
3064  * hook can dereference link or link's underlying program for some time after
3065  * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3066  * BPF program itself can be non-sleepable, yet, because it's transitively
3067  * reachable through BPF link, its freeing has to be delayed until after RCU
3068  * Tasks Trace GP.
3069  */
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)3070 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3071 			     const struct bpf_link_ops *ops, struct bpf_prog *prog,
3072 			     bool sleepable)
3073 {
3074 	WARN_ON(ops->dealloc && ops->dealloc_deferred);
3075 	atomic64_set(&link->refcnt, 1);
3076 	link->type = type;
3077 	link->sleepable = sleepable;
3078 	link->id = 0;
3079 	link->ops = ops;
3080 	link->prog = prog;
3081 }
3082 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)3083 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3084 		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
3085 {
3086 	bpf_link_init_sleepable(link, type, ops, prog, false);
3087 }
3088 
bpf_link_free_id(int id)3089 static void bpf_link_free_id(int id)
3090 {
3091 	if (!id)
3092 		return;
3093 
3094 	spin_lock_bh(&link_idr_lock);
3095 	idr_remove(&link_idr, id);
3096 	spin_unlock_bh(&link_idr_lock);
3097 }
3098 
3099 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3100  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3101  * anon_inode's release() call. This helper marks bpf_link as
3102  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3103  * is not decremented, it's the responsibility of a calling code that failed
3104  * to complete bpf_link initialization.
3105  * This helper eventually calls link's dealloc callback, but does not call
3106  * link's release callback.
3107  */
bpf_link_cleanup(struct bpf_link_primer * primer)3108 void bpf_link_cleanup(struct bpf_link_primer *primer)
3109 {
3110 	primer->link->prog = NULL;
3111 	bpf_link_free_id(primer->id);
3112 	fput(primer->file);
3113 	put_unused_fd(primer->fd);
3114 }
3115 
bpf_link_inc(struct bpf_link * link)3116 void bpf_link_inc(struct bpf_link *link)
3117 {
3118 	atomic64_inc(&link->refcnt);
3119 }
3120 
bpf_link_dealloc(struct bpf_link * link)3121 static void bpf_link_dealloc(struct bpf_link *link)
3122 {
3123 	/* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3124 	if (link->prog)
3125 		bpf_prog_put(link->prog);
3126 
3127 	/* free bpf_link and its containing memory */
3128 	if (link->ops->dealloc_deferred)
3129 		link->ops->dealloc_deferred(link);
3130 	else
3131 		link->ops->dealloc(link);
3132 }
3133 
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3134 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3135 {
3136 	struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3137 
3138 	bpf_link_dealloc(link);
3139 }
3140 
bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head * rcu)3141 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
3142 {
3143 	if (rcu_trace_implies_rcu_gp())
3144 		bpf_link_defer_dealloc_rcu_gp(rcu);
3145 	else
3146 		call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
3147 }
3148 
3149 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3150 static void bpf_link_free(struct bpf_link *link)
3151 {
3152 	const struct bpf_link_ops *ops = link->ops;
3153 
3154 	bpf_link_free_id(link->id);
3155 	/* detach BPF program, clean up used resources */
3156 	if (link->prog)
3157 		ops->release(link);
3158 	if (ops->dealloc_deferred) {
3159 		/* Schedule BPF link deallocation, which will only then
3160 		 * trigger putting BPF program refcount.
3161 		 * If underlying BPF program is sleepable or BPF link's target
3162 		 * attach hookpoint is sleepable or otherwise requires RCU GPs
3163 		 * to ensure link and its underlying BPF program is not
3164 		 * reachable anymore, we need to first wait for RCU tasks
3165 		 * trace sync, and then go through "classic" RCU grace period
3166 		 */
3167 		if (link->sleepable || (link->prog && link->prog->sleepable))
3168 			call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
3169 		else
3170 			call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3171 	} else if (ops->dealloc) {
3172 		bpf_link_dealloc(link);
3173 	}
3174 }
3175 
bpf_link_put_deferred(struct work_struct * work)3176 static void bpf_link_put_deferred(struct work_struct *work)
3177 {
3178 	struct bpf_link *link = container_of(work, struct bpf_link, work);
3179 
3180 	bpf_link_free(link);
3181 }
3182 
3183 /* bpf_link_put might be called from atomic context. It needs to be called
3184  * from sleepable context in order to acquire sleeping locks during the process.
3185  */
bpf_link_put(struct bpf_link * link)3186 void bpf_link_put(struct bpf_link *link)
3187 {
3188 	if (!atomic64_dec_and_test(&link->refcnt))
3189 		return;
3190 
3191 	INIT_WORK(&link->work, bpf_link_put_deferred);
3192 	schedule_work(&link->work);
3193 }
3194 EXPORT_SYMBOL(bpf_link_put);
3195 
bpf_link_put_direct(struct bpf_link * link)3196 static void bpf_link_put_direct(struct bpf_link *link)
3197 {
3198 	if (!atomic64_dec_and_test(&link->refcnt))
3199 		return;
3200 	bpf_link_free(link);
3201 }
3202 
bpf_link_release(struct inode * inode,struct file * filp)3203 static int bpf_link_release(struct inode *inode, struct file *filp)
3204 {
3205 	struct bpf_link *link = filp->private_data;
3206 
3207 	bpf_link_put_direct(link);
3208 	return 0;
3209 }
3210 
3211 #ifdef CONFIG_PROC_FS
3212 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3213 #define BPF_MAP_TYPE(_id, _ops)
3214 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3215 static const char *bpf_link_type_strs[] = {
3216 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3217 #include <linux/bpf_types.h>
3218 };
3219 #undef BPF_PROG_TYPE
3220 #undef BPF_MAP_TYPE
3221 #undef BPF_LINK_TYPE
3222 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3223 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3224 {
3225 	const struct bpf_link *link = filp->private_data;
3226 	const struct bpf_prog *prog = link->prog;
3227 	enum bpf_link_type type = link->type;
3228 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3229 
3230 	if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3231 		seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3232 	} else {
3233 		WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3234 		seq_printf(m, "link_type:\t<%u>\n", type);
3235 	}
3236 	seq_printf(m, "link_id:\t%u\n", link->id);
3237 
3238 	if (prog) {
3239 		bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3240 		seq_printf(m,
3241 			   "prog_tag:\t%s\n"
3242 			   "prog_id:\t%u\n",
3243 			   prog_tag,
3244 			   prog->aux->id);
3245 	}
3246 	if (link->ops->show_fdinfo)
3247 		link->ops->show_fdinfo(link, m);
3248 }
3249 #endif
3250 
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3251 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3252 {
3253 	struct bpf_link *link = file->private_data;
3254 
3255 	return link->ops->poll(file, pts);
3256 }
3257 
3258 static const struct file_operations bpf_link_fops = {
3259 #ifdef CONFIG_PROC_FS
3260 	.show_fdinfo	= bpf_link_show_fdinfo,
3261 #endif
3262 	.release	= bpf_link_release,
3263 	.read		= bpf_dummy_read,
3264 	.write		= bpf_dummy_write,
3265 };
3266 
3267 static const struct file_operations bpf_link_fops_poll = {
3268 #ifdef CONFIG_PROC_FS
3269 	.show_fdinfo	= bpf_link_show_fdinfo,
3270 #endif
3271 	.release	= bpf_link_release,
3272 	.read		= bpf_dummy_read,
3273 	.write		= bpf_dummy_write,
3274 	.poll		= bpf_link_poll,
3275 };
3276 
bpf_link_alloc_id(struct bpf_link * link)3277 static int bpf_link_alloc_id(struct bpf_link *link)
3278 {
3279 	int id;
3280 
3281 	idr_preload(GFP_KERNEL);
3282 	spin_lock_bh(&link_idr_lock);
3283 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3284 	spin_unlock_bh(&link_idr_lock);
3285 	idr_preload_end();
3286 
3287 	return id;
3288 }
3289 
3290 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3291  * reserving unused FD and allocating ID from link_idr. This is to be paired
3292  * with bpf_link_settle() to install FD and ID and expose bpf_link to
3293  * user-space, if bpf_link is successfully attached. If not, bpf_link and
3294  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3295  * transient state is passed around in struct bpf_link_primer.
3296  * This is preferred way to create and initialize bpf_link, especially when
3297  * there are complicated and expensive operations in between creating bpf_link
3298  * itself and attaching it to BPF hook. By using bpf_link_prime() and
3299  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3300  * expensive (and potentially failing) roll back operations in a rare case
3301  * that file, FD, or ID can't be allocated.
3302  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3303 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3304 {
3305 	struct file *file;
3306 	int fd, id;
3307 
3308 	fd = get_unused_fd_flags(O_CLOEXEC);
3309 	if (fd < 0)
3310 		return fd;
3311 
3312 
3313 	id = bpf_link_alloc_id(link);
3314 	if (id < 0) {
3315 		put_unused_fd(fd);
3316 		return id;
3317 	}
3318 
3319 	file = anon_inode_getfile("bpf_link",
3320 				  link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3321 				  link, O_CLOEXEC);
3322 	if (IS_ERR(file)) {
3323 		bpf_link_free_id(id);
3324 		put_unused_fd(fd);
3325 		return PTR_ERR(file);
3326 	}
3327 
3328 	primer->link = link;
3329 	primer->file = file;
3330 	primer->fd = fd;
3331 	primer->id = id;
3332 	return 0;
3333 }
3334 
bpf_link_settle(struct bpf_link_primer * primer)3335 int bpf_link_settle(struct bpf_link_primer *primer)
3336 {
3337 	/* make bpf_link fetchable by ID */
3338 	spin_lock_bh(&link_idr_lock);
3339 	primer->link->id = primer->id;
3340 	spin_unlock_bh(&link_idr_lock);
3341 	/* make bpf_link fetchable by FD */
3342 	fd_install(primer->fd, primer->file);
3343 	/* pass through installed FD */
3344 	return primer->fd;
3345 }
3346 
bpf_link_new_fd(struct bpf_link * link)3347 int bpf_link_new_fd(struct bpf_link *link)
3348 {
3349 	return anon_inode_getfd("bpf-link",
3350 				link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3351 				link, O_CLOEXEC);
3352 }
3353 
bpf_link_get_from_fd(u32 ufd)3354 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3355 {
3356 	CLASS(fd, f)(ufd);
3357 	struct bpf_link *link;
3358 
3359 	if (fd_empty(f))
3360 		return ERR_PTR(-EBADF);
3361 	if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3362 		return ERR_PTR(-EINVAL);
3363 
3364 	link = fd_file(f)->private_data;
3365 	bpf_link_inc(link);
3366 	return link;
3367 }
3368 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL");
3369 
bpf_tracing_link_release(struct bpf_link * link)3370 static void bpf_tracing_link_release(struct bpf_link *link)
3371 {
3372 	struct bpf_tracing_link *tr_link =
3373 		container_of(link, struct bpf_tracing_link, link.link);
3374 
3375 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3376 						tr_link->trampoline,
3377 						tr_link->tgt_prog));
3378 
3379 	bpf_trampoline_put(tr_link->trampoline);
3380 
3381 	/* tgt_prog is NULL if target is a kernel function */
3382 	if (tr_link->tgt_prog)
3383 		bpf_prog_put(tr_link->tgt_prog);
3384 }
3385 
bpf_tracing_link_dealloc(struct bpf_link * link)3386 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3387 {
3388 	struct bpf_tracing_link *tr_link =
3389 		container_of(link, struct bpf_tracing_link, link.link);
3390 
3391 	kfree(tr_link);
3392 }
3393 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3394 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3395 					 struct seq_file *seq)
3396 {
3397 	struct bpf_tracing_link *tr_link =
3398 		container_of(link, struct bpf_tracing_link, link.link);
3399 	u32 target_btf_id, target_obj_id;
3400 
3401 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3402 				  &target_obj_id, &target_btf_id);
3403 	seq_printf(seq,
3404 		   "attach_type:\t%d\n"
3405 		   "target_obj_id:\t%u\n"
3406 		   "target_btf_id:\t%u\n",
3407 		   tr_link->attach_type,
3408 		   target_obj_id,
3409 		   target_btf_id);
3410 }
3411 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3412 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3413 					   struct bpf_link_info *info)
3414 {
3415 	struct bpf_tracing_link *tr_link =
3416 		container_of(link, struct bpf_tracing_link, link.link);
3417 
3418 	info->tracing.attach_type = tr_link->attach_type;
3419 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3420 				  &info->tracing.target_obj_id,
3421 				  &info->tracing.target_btf_id);
3422 
3423 	return 0;
3424 }
3425 
3426 static const struct bpf_link_ops bpf_tracing_link_lops = {
3427 	.release = bpf_tracing_link_release,
3428 	.dealloc = bpf_tracing_link_dealloc,
3429 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3430 	.fill_link_info = bpf_tracing_link_fill_link_info,
3431 };
3432 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)3433 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3434 				   int tgt_prog_fd,
3435 				   u32 btf_id,
3436 				   u64 bpf_cookie)
3437 {
3438 	struct bpf_link_primer link_primer;
3439 	struct bpf_prog *tgt_prog = NULL;
3440 	struct bpf_trampoline *tr = NULL;
3441 	struct bpf_tracing_link *link;
3442 	u64 key = 0;
3443 	int err;
3444 
3445 	switch (prog->type) {
3446 	case BPF_PROG_TYPE_TRACING:
3447 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3448 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3449 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3450 			err = -EINVAL;
3451 			goto out_put_prog;
3452 		}
3453 		break;
3454 	case BPF_PROG_TYPE_EXT:
3455 		if (prog->expected_attach_type != 0) {
3456 			err = -EINVAL;
3457 			goto out_put_prog;
3458 		}
3459 		break;
3460 	case BPF_PROG_TYPE_LSM:
3461 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3462 			err = -EINVAL;
3463 			goto out_put_prog;
3464 		}
3465 		break;
3466 	default:
3467 		err = -EINVAL;
3468 		goto out_put_prog;
3469 	}
3470 
3471 	if (!!tgt_prog_fd != !!btf_id) {
3472 		err = -EINVAL;
3473 		goto out_put_prog;
3474 	}
3475 
3476 	if (tgt_prog_fd) {
3477 		/*
3478 		 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3479 		 * part would be changed to implement the same for
3480 		 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3481 		 * attach_tracing_prog flag is set.
3482 		 */
3483 		if (prog->type != BPF_PROG_TYPE_EXT) {
3484 			err = -EINVAL;
3485 			goto out_put_prog;
3486 		}
3487 
3488 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3489 		if (IS_ERR(tgt_prog)) {
3490 			err = PTR_ERR(tgt_prog);
3491 			tgt_prog = NULL;
3492 			goto out_put_prog;
3493 		}
3494 
3495 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3496 	}
3497 
3498 	link = kzalloc(sizeof(*link), GFP_USER);
3499 	if (!link) {
3500 		err = -ENOMEM;
3501 		goto out_put_prog;
3502 	}
3503 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3504 		      &bpf_tracing_link_lops, prog);
3505 	link->attach_type = prog->expected_attach_type;
3506 	link->link.cookie = bpf_cookie;
3507 
3508 	mutex_lock(&prog->aux->dst_mutex);
3509 
3510 	/* There are a few possible cases here:
3511 	 *
3512 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3513 	 *   and not yet attached to anything, so we can use the values stored
3514 	 *   in prog->aux
3515 	 *
3516 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3517 	 *   attached to a target and its initial target was cleared (below)
3518 	 *
3519 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3520 	 *   target_btf_id using the link_create API.
3521 	 *
3522 	 * - if tgt_prog == NULL when this function was called using the old
3523 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3524 	 *
3525 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3526 	 *   was detached and is going for re-attachment.
3527 	 *
3528 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3529 	 *   are NULL, then program was already attached and user did not provide
3530 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3531 	 */
3532 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3533 		/*
3534 		 * Allow re-attach for TRACING and LSM programs. If it's
3535 		 * currently linked, bpf_trampoline_link_prog will fail.
3536 		 * EXT programs need to specify tgt_prog_fd, so they
3537 		 * re-attach in separate code path.
3538 		 */
3539 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3540 		    prog->type != BPF_PROG_TYPE_LSM) {
3541 			err = -EINVAL;
3542 			goto out_unlock;
3543 		}
3544 		/* We can allow re-attach only if we have valid attach_btf. */
3545 		if (!prog->aux->attach_btf) {
3546 			err = -EINVAL;
3547 			goto out_unlock;
3548 		}
3549 		btf_id = prog->aux->attach_btf_id;
3550 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3551 	}
3552 
3553 	if (!prog->aux->dst_trampoline ||
3554 	    (key && key != prog->aux->dst_trampoline->key)) {
3555 		/* If there is no saved target, or the specified target is
3556 		 * different from the destination specified at load time, we
3557 		 * need a new trampoline and a check for compatibility
3558 		 */
3559 		struct bpf_attach_target_info tgt_info = {};
3560 
3561 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3562 					      &tgt_info);
3563 		if (err)
3564 			goto out_unlock;
3565 
3566 		if (tgt_info.tgt_mod) {
3567 			module_put(prog->aux->mod);
3568 			prog->aux->mod = tgt_info.tgt_mod;
3569 		}
3570 
3571 		tr = bpf_trampoline_get(key, &tgt_info);
3572 		if (!tr) {
3573 			err = -ENOMEM;
3574 			goto out_unlock;
3575 		}
3576 	} else {
3577 		/* The caller didn't specify a target, or the target was the
3578 		 * same as the destination supplied during program load. This
3579 		 * means we can reuse the trampoline and reference from program
3580 		 * load time, and there is no need to allocate a new one. This
3581 		 * can only happen once for any program, as the saved values in
3582 		 * prog->aux are cleared below.
3583 		 */
3584 		tr = prog->aux->dst_trampoline;
3585 		tgt_prog = prog->aux->dst_prog;
3586 	}
3587 
3588 	err = bpf_link_prime(&link->link.link, &link_primer);
3589 	if (err)
3590 		goto out_unlock;
3591 
3592 	err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3593 	if (err) {
3594 		bpf_link_cleanup(&link_primer);
3595 		link = NULL;
3596 		goto out_unlock;
3597 	}
3598 
3599 	link->tgt_prog = tgt_prog;
3600 	link->trampoline = tr;
3601 
3602 	/* Always clear the trampoline and target prog from prog->aux to make
3603 	 * sure the original attach destination is not kept alive after a
3604 	 * program is (re-)attached to another target.
3605 	 */
3606 	if (prog->aux->dst_prog &&
3607 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3608 		/* got extra prog ref from syscall, or attaching to different prog */
3609 		bpf_prog_put(prog->aux->dst_prog);
3610 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3611 		/* we allocated a new trampoline, so free the old one */
3612 		bpf_trampoline_put(prog->aux->dst_trampoline);
3613 
3614 	prog->aux->dst_prog = NULL;
3615 	prog->aux->dst_trampoline = NULL;
3616 	mutex_unlock(&prog->aux->dst_mutex);
3617 
3618 	return bpf_link_settle(&link_primer);
3619 out_unlock:
3620 	if (tr && tr != prog->aux->dst_trampoline)
3621 		bpf_trampoline_put(tr);
3622 	mutex_unlock(&prog->aux->dst_mutex);
3623 	kfree(link);
3624 out_put_prog:
3625 	if (tgt_prog_fd && tgt_prog)
3626 		bpf_prog_put(tgt_prog);
3627 	return err;
3628 }
3629 
bpf_raw_tp_link_release(struct bpf_link * link)3630 static void bpf_raw_tp_link_release(struct bpf_link *link)
3631 {
3632 	struct bpf_raw_tp_link *raw_tp =
3633 		container_of(link, struct bpf_raw_tp_link, link);
3634 
3635 	bpf_probe_unregister(raw_tp->btp, raw_tp);
3636 	bpf_put_raw_tracepoint(raw_tp->btp);
3637 }
3638 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3639 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3640 {
3641 	struct bpf_raw_tp_link *raw_tp =
3642 		container_of(link, struct bpf_raw_tp_link, link);
3643 
3644 	kfree(raw_tp);
3645 }
3646 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3647 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3648 					struct seq_file *seq)
3649 {
3650 	struct bpf_raw_tp_link *raw_tp_link =
3651 		container_of(link, struct bpf_raw_tp_link, link);
3652 
3653 	seq_printf(seq,
3654 		   "tp_name:\t%s\n",
3655 		   raw_tp_link->btp->tp->name);
3656 }
3657 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3658 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3659 			    u32 len)
3660 {
3661 	if (ulen >= len + 1) {
3662 		if (copy_to_user(ubuf, buf, len + 1))
3663 			return -EFAULT;
3664 	} else {
3665 		char zero = '\0';
3666 
3667 		if (copy_to_user(ubuf, buf, ulen - 1))
3668 			return -EFAULT;
3669 		if (put_user(zero, ubuf + ulen - 1))
3670 			return -EFAULT;
3671 		return -ENOSPC;
3672 	}
3673 
3674 	return 0;
3675 }
3676 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3677 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3678 					  struct bpf_link_info *info)
3679 {
3680 	struct bpf_raw_tp_link *raw_tp_link =
3681 		container_of(link, struct bpf_raw_tp_link, link);
3682 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3683 	const char *tp_name = raw_tp_link->btp->tp->name;
3684 	u32 ulen = info->raw_tracepoint.tp_name_len;
3685 	size_t tp_len = strlen(tp_name);
3686 
3687 	if (!ulen ^ !ubuf)
3688 		return -EINVAL;
3689 
3690 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3691 
3692 	if (!ubuf)
3693 		return 0;
3694 
3695 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3696 }
3697 
3698 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3699 	.release = bpf_raw_tp_link_release,
3700 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3701 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3702 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3703 };
3704 
3705 #ifdef CONFIG_PERF_EVENTS
3706 struct bpf_perf_link {
3707 	struct bpf_link link;
3708 	struct file *perf_file;
3709 };
3710 
bpf_perf_link_release(struct bpf_link * link)3711 static void bpf_perf_link_release(struct bpf_link *link)
3712 {
3713 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3714 	struct perf_event *event = perf_link->perf_file->private_data;
3715 
3716 	perf_event_free_bpf_prog(event);
3717 	fput(perf_link->perf_file);
3718 }
3719 
bpf_perf_link_dealloc(struct bpf_link * link)3720 static void bpf_perf_link_dealloc(struct bpf_link *link)
3721 {
3722 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3723 
3724 	kfree(perf_link);
3725 }
3726 
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)3727 static int bpf_perf_link_fill_common(const struct perf_event *event,
3728 				     char __user *uname, u32 *ulenp,
3729 				     u64 *probe_offset, u64 *probe_addr,
3730 				     u32 *fd_type, unsigned long *missed)
3731 {
3732 	const char *buf;
3733 	u32 prog_id, ulen;
3734 	size_t len;
3735 	int err;
3736 
3737 	ulen = *ulenp;
3738 	if (!ulen ^ !uname)
3739 		return -EINVAL;
3740 
3741 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3742 				      probe_offset, probe_addr, missed);
3743 	if (err)
3744 		return err;
3745 
3746 	if (buf) {
3747 		len = strlen(buf);
3748 		*ulenp = len + 1;
3749 	} else {
3750 		*ulenp = 1;
3751 	}
3752 	if (!uname)
3753 		return 0;
3754 
3755 	if (buf) {
3756 		err = bpf_copy_to_user(uname, buf, ulen, len);
3757 		if (err)
3758 			return err;
3759 	} else {
3760 		char zero = '\0';
3761 
3762 		if (put_user(zero, uname))
3763 			return -EFAULT;
3764 	}
3765 	return 0;
3766 }
3767 
3768 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3769 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3770 				     struct bpf_link_info *info)
3771 {
3772 	unsigned long missed;
3773 	char __user *uname;
3774 	u64 addr, offset;
3775 	u32 ulen, type;
3776 	int err;
3777 
3778 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3779 	ulen = info->perf_event.kprobe.name_len;
3780 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3781 					&type, &missed);
3782 	if (err)
3783 		return err;
3784 	if (type == BPF_FD_TYPE_KRETPROBE)
3785 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3786 	else
3787 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3788 	info->perf_event.kprobe.name_len = ulen;
3789 	info->perf_event.kprobe.offset = offset;
3790 	info->perf_event.kprobe.missed = missed;
3791 	if (!kallsyms_show_value(current_cred()))
3792 		addr = 0;
3793 	info->perf_event.kprobe.addr = addr;
3794 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3795 	return 0;
3796 }
3797 #endif
3798 
3799 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3800 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3801 				     struct bpf_link_info *info)
3802 {
3803 	u64 ref_ctr_offset, offset;
3804 	char __user *uname;
3805 	u32 ulen, type;
3806 	int err;
3807 
3808 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3809 	ulen = info->perf_event.uprobe.name_len;
3810 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset,
3811 					&type, NULL);
3812 	if (err)
3813 		return err;
3814 
3815 	if (type == BPF_FD_TYPE_URETPROBE)
3816 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3817 	else
3818 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3819 	info->perf_event.uprobe.name_len = ulen;
3820 	info->perf_event.uprobe.offset = offset;
3821 	info->perf_event.uprobe.cookie = event->bpf_cookie;
3822 	info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset;
3823 	return 0;
3824 }
3825 #endif
3826 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)3827 static int bpf_perf_link_fill_probe(const struct perf_event *event,
3828 				    struct bpf_link_info *info)
3829 {
3830 #ifdef CONFIG_KPROBE_EVENTS
3831 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
3832 		return bpf_perf_link_fill_kprobe(event, info);
3833 #endif
3834 #ifdef CONFIG_UPROBE_EVENTS
3835 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
3836 		return bpf_perf_link_fill_uprobe(event, info);
3837 #endif
3838 	return -EOPNOTSUPP;
3839 }
3840 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)3841 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
3842 					 struct bpf_link_info *info)
3843 {
3844 	char __user *uname;
3845 	u32 ulen;
3846 	int err;
3847 
3848 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
3849 	ulen = info->perf_event.tracepoint.name_len;
3850 	err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
3851 	if (err)
3852 		return err;
3853 
3854 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
3855 	info->perf_event.tracepoint.name_len = ulen;
3856 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
3857 	return 0;
3858 }
3859 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)3860 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
3861 					 struct bpf_link_info *info)
3862 {
3863 	info->perf_event.event.type = event->attr.type;
3864 	info->perf_event.event.config = event->attr.config;
3865 	info->perf_event.event.cookie = event->bpf_cookie;
3866 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
3867 	return 0;
3868 }
3869 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3870 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
3871 					struct bpf_link_info *info)
3872 {
3873 	struct bpf_perf_link *perf_link;
3874 	const struct perf_event *event;
3875 
3876 	perf_link = container_of(link, struct bpf_perf_link, link);
3877 	event = perf_get_event(perf_link->perf_file);
3878 	if (IS_ERR(event))
3879 		return PTR_ERR(event);
3880 
3881 	switch (event->prog->type) {
3882 	case BPF_PROG_TYPE_PERF_EVENT:
3883 		return bpf_perf_link_fill_perf_event(event, info);
3884 	case BPF_PROG_TYPE_TRACEPOINT:
3885 		return bpf_perf_link_fill_tracepoint(event, info);
3886 	case BPF_PROG_TYPE_KPROBE:
3887 		return bpf_perf_link_fill_probe(event, info);
3888 	default:
3889 		return -EOPNOTSUPP;
3890 	}
3891 }
3892 
3893 static const struct bpf_link_ops bpf_perf_link_lops = {
3894 	.release = bpf_perf_link_release,
3895 	.dealloc = bpf_perf_link_dealloc,
3896 	.fill_link_info = bpf_perf_link_fill_link_info,
3897 };
3898 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3899 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3900 {
3901 	struct bpf_link_primer link_primer;
3902 	struct bpf_perf_link *link;
3903 	struct perf_event *event;
3904 	struct file *perf_file;
3905 	int err;
3906 
3907 	if (attr->link_create.flags)
3908 		return -EINVAL;
3909 
3910 	perf_file = perf_event_get(attr->link_create.target_fd);
3911 	if (IS_ERR(perf_file))
3912 		return PTR_ERR(perf_file);
3913 
3914 	link = kzalloc(sizeof(*link), GFP_USER);
3915 	if (!link) {
3916 		err = -ENOMEM;
3917 		goto out_put_file;
3918 	}
3919 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3920 	link->perf_file = perf_file;
3921 
3922 	err = bpf_link_prime(&link->link, &link_primer);
3923 	if (err) {
3924 		kfree(link);
3925 		goto out_put_file;
3926 	}
3927 
3928 	event = perf_file->private_data;
3929 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3930 	if (err) {
3931 		bpf_link_cleanup(&link_primer);
3932 		goto out_put_file;
3933 	}
3934 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3935 	bpf_prog_inc(prog);
3936 
3937 	return bpf_link_settle(&link_primer);
3938 
3939 out_put_file:
3940 	fput(perf_file);
3941 	return err;
3942 }
3943 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3944 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3945 {
3946 	return -EOPNOTSUPP;
3947 }
3948 #endif /* CONFIG_PERF_EVENTS */
3949 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie)3950 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3951 				  const char __user *user_tp_name, u64 cookie)
3952 {
3953 	struct bpf_link_primer link_primer;
3954 	struct bpf_raw_tp_link *link;
3955 	struct bpf_raw_event_map *btp;
3956 	const char *tp_name;
3957 	char buf[128];
3958 	int err;
3959 
3960 	switch (prog->type) {
3961 	case BPF_PROG_TYPE_TRACING:
3962 	case BPF_PROG_TYPE_EXT:
3963 	case BPF_PROG_TYPE_LSM:
3964 		if (user_tp_name)
3965 			/* The attach point for this category of programs
3966 			 * should be specified via btf_id during program load.
3967 			 */
3968 			return -EINVAL;
3969 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3970 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3971 			tp_name = prog->aux->attach_func_name;
3972 			break;
3973 		}
3974 		return bpf_tracing_prog_attach(prog, 0, 0, 0);
3975 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3976 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3977 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3978 			return -EFAULT;
3979 		buf[sizeof(buf) - 1] = 0;
3980 		tp_name = buf;
3981 		break;
3982 	default:
3983 		return -EINVAL;
3984 	}
3985 
3986 	btp = bpf_get_raw_tracepoint(tp_name);
3987 	if (!btp)
3988 		return -ENOENT;
3989 
3990 	link = kzalloc(sizeof(*link), GFP_USER);
3991 	if (!link) {
3992 		err = -ENOMEM;
3993 		goto out_put_btp;
3994 	}
3995 	bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3996 				&bpf_raw_tp_link_lops, prog,
3997 				tracepoint_is_faultable(btp->tp));
3998 	link->btp = btp;
3999 	link->cookie = cookie;
4000 
4001 	err = bpf_link_prime(&link->link, &link_primer);
4002 	if (err) {
4003 		kfree(link);
4004 		goto out_put_btp;
4005 	}
4006 
4007 	err = bpf_probe_register(link->btp, link);
4008 	if (err) {
4009 		bpf_link_cleanup(&link_primer);
4010 		goto out_put_btp;
4011 	}
4012 
4013 	return bpf_link_settle(&link_primer);
4014 
4015 out_put_btp:
4016 	bpf_put_raw_tracepoint(btp);
4017 	return err;
4018 }
4019 
4020 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4021 
bpf_raw_tracepoint_open(const union bpf_attr * attr)4022 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4023 {
4024 	struct bpf_prog *prog;
4025 	void __user *tp_name;
4026 	__u64 cookie;
4027 	int fd;
4028 
4029 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4030 		return -EINVAL;
4031 
4032 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4033 	if (IS_ERR(prog))
4034 		return PTR_ERR(prog);
4035 
4036 	tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4037 	cookie = attr->raw_tracepoint.cookie;
4038 	fd = bpf_raw_tp_link_attach(prog, tp_name, cookie);
4039 	if (fd < 0)
4040 		bpf_prog_put(prog);
4041 	return fd;
4042 }
4043 
4044 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4045 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4046 {
4047 	switch (attach_type) {
4048 	case BPF_CGROUP_INET_INGRESS:
4049 	case BPF_CGROUP_INET_EGRESS:
4050 		return BPF_PROG_TYPE_CGROUP_SKB;
4051 	case BPF_CGROUP_INET_SOCK_CREATE:
4052 	case BPF_CGROUP_INET_SOCK_RELEASE:
4053 	case BPF_CGROUP_INET4_POST_BIND:
4054 	case BPF_CGROUP_INET6_POST_BIND:
4055 		return BPF_PROG_TYPE_CGROUP_SOCK;
4056 	case BPF_CGROUP_INET4_BIND:
4057 	case BPF_CGROUP_INET6_BIND:
4058 	case BPF_CGROUP_INET4_CONNECT:
4059 	case BPF_CGROUP_INET6_CONNECT:
4060 	case BPF_CGROUP_UNIX_CONNECT:
4061 	case BPF_CGROUP_INET4_GETPEERNAME:
4062 	case BPF_CGROUP_INET6_GETPEERNAME:
4063 	case BPF_CGROUP_UNIX_GETPEERNAME:
4064 	case BPF_CGROUP_INET4_GETSOCKNAME:
4065 	case BPF_CGROUP_INET6_GETSOCKNAME:
4066 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4067 	case BPF_CGROUP_UDP4_SENDMSG:
4068 	case BPF_CGROUP_UDP6_SENDMSG:
4069 	case BPF_CGROUP_UNIX_SENDMSG:
4070 	case BPF_CGROUP_UDP4_RECVMSG:
4071 	case BPF_CGROUP_UDP6_RECVMSG:
4072 	case BPF_CGROUP_UNIX_RECVMSG:
4073 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4074 	case BPF_CGROUP_SOCK_OPS:
4075 		return BPF_PROG_TYPE_SOCK_OPS;
4076 	case BPF_CGROUP_DEVICE:
4077 		return BPF_PROG_TYPE_CGROUP_DEVICE;
4078 	case BPF_SK_MSG_VERDICT:
4079 		return BPF_PROG_TYPE_SK_MSG;
4080 	case BPF_SK_SKB_STREAM_PARSER:
4081 	case BPF_SK_SKB_STREAM_VERDICT:
4082 	case BPF_SK_SKB_VERDICT:
4083 		return BPF_PROG_TYPE_SK_SKB;
4084 	case BPF_LIRC_MODE2:
4085 		return BPF_PROG_TYPE_LIRC_MODE2;
4086 	case BPF_FLOW_DISSECTOR:
4087 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
4088 	case BPF_CGROUP_SYSCTL:
4089 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
4090 	case BPF_CGROUP_GETSOCKOPT:
4091 	case BPF_CGROUP_SETSOCKOPT:
4092 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4093 	case BPF_TRACE_ITER:
4094 	case BPF_TRACE_RAW_TP:
4095 	case BPF_TRACE_FENTRY:
4096 	case BPF_TRACE_FEXIT:
4097 	case BPF_MODIFY_RETURN:
4098 		return BPF_PROG_TYPE_TRACING;
4099 	case BPF_LSM_MAC:
4100 		return BPF_PROG_TYPE_LSM;
4101 	case BPF_SK_LOOKUP:
4102 		return BPF_PROG_TYPE_SK_LOOKUP;
4103 	case BPF_XDP:
4104 		return BPF_PROG_TYPE_XDP;
4105 	case BPF_LSM_CGROUP:
4106 		return BPF_PROG_TYPE_LSM;
4107 	case BPF_TCX_INGRESS:
4108 	case BPF_TCX_EGRESS:
4109 	case BPF_NETKIT_PRIMARY:
4110 	case BPF_NETKIT_PEER:
4111 		return BPF_PROG_TYPE_SCHED_CLS;
4112 	default:
4113 		return BPF_PROG_TYPE_UNSPEC;
4114 	}
4115 }
4116 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4117 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4118 					     enum bpf_attach_type attach_type)
4119 {
4120 	enum bpf_prog_type ptype;
4121 
4122 	switch (prog->type) {
4123 	case BPF_PROG_TYPE_CGROUP_SOCK:
4124 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4125 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4126 	case BPF_PROG_TYPE_SK_LOOKUP:
4127 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4128 	case BPF_PROG_TYPE_CGROUP_SKB:
4129 		if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4130 			/* cg-skb progs can be loaded by unpriv user.
4131 			 * check permissions at attach time.
4132 			 */
4133 			return -EPERM;
4134 
4135 		ptype = attach_type_to_prog_type(attach_type);
4136 		if (prog->type != ptype)
4137 			return -EINVAL;
4138 
4139 		return prog->enforce_expected_attach_type &&
4140 			prog->expected_attach_type != attach_type ?
4141 			-EINVAL : 0;
4142 	case BPF_PROG_TYPE_EXT:
4143 		return 0;
4144 	case BPF_PROG_TYPE_NETFILTER:
4145 		if (attach_type != BPF_NETFILTER)
4146 			return -EINVAL;
4147 		return 0;
4148 	case BPF_PROG_TYPE_PERF_EVENT:
4149 	case BPF_PROG_TYPE_TRACEPOINT:
4150 		if (attach_type != BPF_PERF_EVENT)
4151 			return -EINVAL;
4152 		return 0;
4153 	case BPF_PROG_TYPE_KPROBE:
4154 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4155 		    attach_type != BPF_TRACE_KPROBE_MULTI)
4156 			return -EINVAL;
4157 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4158 		    attach_type != BPF_TRACE_KPROBE_SESSION)
4159 			return -EINVAL;
4160 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4161 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4162 			return -EINVAL;
4163 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4164 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4165 			return -EINVAL;
4166 		if (attach_type != BPF_PERF_EVENT &&
4167 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
4168 		    attach_type != BPF_TRACE_KPROBE_SESSION &&
4169 		    attach_type != BPF_TRACE_UPROBE_MULTI &&
4170 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4171 			return -EINVAL;
4172 		return 0;
4173 	case BPF_PROG_TYPE_SCHED_CLS:
4174 		if (attach_type != BPF_TCX_INGRESS &&
4175 		    attach_type != BPF_TCX_EGRESS &&
4176 		    attach_type != BPF_NETKIT_PRIMARY &&
4177 		    attach_type != BPF_NETKIT_PEER)
4178 			return -EINVAL;
4179 		return 0;
4180 	default:
4181 		ptype = attach_type_to_prog_type(attach_type);
4182 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4183 			return -EINVAL;
4184 		return 0;
4185 	}
4186 }
4187 
4188 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4189 
4190 #define BPF_F_ATTACH_MASK_BASE	\
4191 	(BPF_F_ALLOW_OVERRIDE |	\
4192 	 BPF_F_ALLOW_MULTI |	\
4193 	 BPF_F_REPLACE |	\
4194 	 BPF_F_PREORDER)
4195 
4196 #define BPF_F_ATTACH_MASK_MPROG	\
4197 	(BPF_F_REPLACE |	\
4198 	 BPF_F_BEFORE |		\
4199 	 BPF_F_AFTER |		\
4200 	 BPF_F_ID |		\
4201 	 BPF_F_LINK)
4202 
bpf_prog_attach(const union bpf_attr * attr)4203 static int bpf_prog_attach(const union bpf_attr *attr)
4204 {
4205 	enum bpf_prog_type ptype;
4206 	struct bpf_prog *prog;
4207 	int ret;
4208 
4209 	if (CHECK_ATTR(BPF_PROG_ATTACH))
4210 		return -EINVAL;
4211 
4212 	ptype = attach_type_to_prog_type(attr->attach_type);
4213 	if (ptype == BPF_PROG_TYPE_UNSPEC)
4214 		return -EINVAL;
4215 	if (bpf_mprog_supported(ptype)) {
4216 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4217 			return -EINVAL;
4218 	} else {
4219 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4220 			return -EINVAL;
4221 		if (attr->relative_fd ||
4222 		    attr->expected_revision)
4223 			return -EINVAL;
4224 	}
4225 
4226 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4227 	if (IS_ERR(prog))
4228 		return PTR_ERR(prog);
4229 
4230 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4231 		bpf_prog_put(prog);
4232 		return -EINVAL;
4233 	}
4234 
4235 	switch (ptype) {
4236 	case BPF_PROG_TYPE_SK_SKB:
4237 	case BPF_PROG_TYPE_SK_MSG:
4238 		ret = sock_map_get_from_fd(attr, prog);
4239 		break;
4240 	case BPF_PROG_TYPE_LIRC_MODE2:
4241 		ret = lirc_prog_attach(attr, prog);
4242 		break;
4243 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4244 		ret = netns_bpf_prog_attach(attr, prog);
4245 		break;
4246 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4247 	case BPF_PROG_TYPE_CGROUP_SKB:
4248 	case BPF_PROG_TYPE_CGROUP_SOCK:
4249 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4250 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4251 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4252 	case BPF_PROG_TYPE_SOCK_OPS:
4253 	case BPF_PROG_TYPE_LSM:
4254 		if (ptype == BPF_PROG_TYPE_LSM &&
4255 		    prog->expected_attach_type != BPF_LSM_CGROUP)
4256 			ret = -EINVAL;
4257 		else
4258 			ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4259 		break;
4260 	case BPF_PROG_TYPE_SCHED_CLS:
4261 		if (attr->attach_type == BPF_TCX_INGRESS ||
4262 		    attr->attach_type == BPF_TCX_EGRESS)
4263 			ret = tcx_prog_attach(attr, prog);
4264 		else
4265 			ret = netkit_prog_attach(attr, prog);
4266 		break;
4267 	default:
4268 		ret = -EINVAL;
4269 	}
4270 
4271 	if (ret)
4272 		bpf_prog_put(prog);
4273 	return ret;
4274 }
4275 
4276 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4277 
bpf_prog_detach(const union bpf_attr * attr)4278 static int bpf_prog_detach(const union bpf_attr *attr)
4279 {
4280 	struct bpf_prog *prog = NULL;
4281 	enum bpf_prog_type ptype;
4282 	int ret;
4283 
4284 	if (CHECK_ATTR(BPF_PROG_DETACH))
4285 		return -EINVAL;
4286 
4287 	ptype = attach_type_to_prog_type(attr->attach_type);
4288 	if (bpf_mprog_supported(ptype)) {
4289 		if (ptype == BPF_PROG_TYPE_UNSPEC)
4290 			return -EINVAL;
4291 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4292 			return -EINVAL;
4293 		if (attr->attach_bpf_fd) {
4294 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4295 			if (IS_ERR(prog))
4296 				return PTR_ERR(prog);
4297 		}
4298 	} else if (attr->attach_flags ||
4299 		   attr->relative_fd ||
4300 		   attr->expected_revision) {
4301 		return -EINVAL;
4302 	}
4303 
4304 	switch (ptype) {
4305 	case BPF_PROG_TYPE_SK_MSG:
4306 	case BPF_PROG_TYPE_SK_SKB:
4307 		ret = sock_map_prog_detach(attr, ptype);
4308 		break;
4309 	case BPF_PROG_TYPE_LIRC_MODE2:
4310 		ret = lirc_prog_detach(attr);
4311 		break;
4312 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4313 		ret = netns_bpf_prog_detach(attr, ptype);
4314 		break;
4315 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4316 	case BPF_PROG_TYPE_CGROUP_SKB:
4317 	case BPF_PROG_TYPE_CGROUP_SOCK:
4318 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4319 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4320 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4321 	case BPF_PROG_TYPE_SOCK_OPS:
4322 	case BPF_PROG_TYPE_LSM:
4323 		ret = cgroup_bpf_prog_detach(attr, ptype);
4324 		break;
4325 	case BPF_PROG_TYPE_SCHED_CLS:
4326 		if (attr->attach_type == BPF_TCX_INGRESS ||
4327 		    attr->attach_type == BPF_TCX_EGRESS)
4328 			ret = tcx_prog_detach(attr, prog);
4329 		else
4330 			ret = netkit_prog_detach(attr, prog);
4331 		break;
4332 	default:
4333 		ret = -EINVAL;
4334 	}
4335 
4336 	if (prog)
4337 		bpf_prog_put(prog);
4338 	return ret;
4339 }
4340 
4341 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4342 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4343 static int bpf_prog_query(const union bpf_attr *attr,
4344 			  union bpf_attr __user *uattr)
4345 {
4346 	if (!bpf_net_capable())
4347 		return -EPERM;
4348 	if (CHECK_ATTR(BPF_PROG_QUERY))
4349 		return -EINVAL;
4350 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4351 		return -EINVAL;
4352 
4353 	switch (attr->query.attach_type) {
4354 	case BPF_CGROUP_INET_INGRESS:
4355 	case BPF_CGROUP_INET_EGRESS:
4356 	case BPF_CGROUP_INET_SOCK_CREATE:
4357 	case BPF_CGROUP_INET_SOCK_RELEASE:
4358 	case BPF_CGROUP_INET4_BIND:
4359 	case BPF_CGROUP_INET6_BIND:
4360 	case BPF_CGROUP_INET4_POST_BIND:
4361 	case BPF_CGROUP_INET6_POST_BIND:
4362 	case BPF_CGROUP_INET4_CONNECT:
4363 	case BPF_CGROUP_INET6_CONNECT:
4364 	case BPF_CGROUP_UNIX_CONNECT:
4365 	case BPF_CGROUP_INET4_GETPEERNAME:
4366 	case BPF_CGROUP_INET6_GETPEERNAME:
4367 	case BPF_CGROUP_UNIX_GETPEERNAME:
4368 	case BPF_CGROUP_INET4_GETSOCKNAME:
4369 	case BPF_CGROUP_INET6_GETSOCKNAME:
4370 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4371 	case BPF_CGROUP_UDP4_SENDMSG:
4372 	case BPF_CGROUP_UDP6_SENDMSG:
4373 	case BPF_CGROUP_UNIX_SENDMSG:
4374 	case BPF_CGROUP_UDP4_RECVMSG:
4375 	case BPF_CGROUP_UDP6_RECVMSG:
4376 	case BPF_CGROUP_UNIX_RECVMSG:
4377 	case BPF_CGROUP_SOCK_OPS:
4378 	case BPF_CGROUP_DEVICE:
4379 	case BPF_CGROUP_SYSCTL:
4380 	case BPF_CGROUP_GETSOCKOPT:
4381 	case BPF_CGROUP_SETSOCKOPT:
4382 	case BPF_LSM_CGROUP:
4383 		return cgroup_bpf_prog_query(attr, uattr);
4384 	case BPF_LIRC_MODE2:
4385 		return lirc_prog_query(attr, uattr);
4386 	case BPF_FLOW_DISSECTOR:
4387 	case BPF_SK_LOOKUP:
4388 		return netns_bpf_prog_query(attr, uattr);
4389 	case BPF_SK_SKB_STREAM_PARSER:
4390 	case BPF_SK_SKB_STREAM_VERDICT:
4391 	case BPF_SK_MSG_VERDICT:
4392 	case BPF_SK_SKB_VERDICT:
4393 		return sock_map_bpf_prog_query(attr, uattr);
4394 	case BPF_TCX_INGRESS:
4395 	case BPF_TCX_EGRESS:
4396 		return tcx_prog_query(attr, uattr);
4397 	case BPF_NETKIT_PRIMARY:
4398 	case BPF_NETKIT_PEER:
4399 		return netkit_prog_query(attr, uattr);
4400 	default:
4401 		return -EINVAL;
4402 	}
4403 }
4404 
4405 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4406 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4407 static int bpf_prog_test_run(const union bpf_attr *attr,
4408 			     union bpf_attr __user *uattr)
4409 {
4410 	struct bpf_prog *prog;
4411 	int ret = -ENOTSUPP;
4412 
4413 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4414 		return -EINVAL;
4415 
4416 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4417 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4418 		return -EINVAL;
4419 
4420 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4421 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4422 		return -EINVAL;
4423 
4424 	prog = bpf_prog_get(attr->test.prog_fd);
4425 	if (IS_ERR(prog))
4426 		return PTR_ERR(prog);
4427 
4428 	if (prog->aux->ops->test_run)
4429 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4430 
4431 	bpf_prog_put(prog);
4432 	return ret;
4433 }
4434 
4435 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4436 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4437 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4438 			       union bpf_attr __user *uattr,
4439 			       struct idr *idr,
4440 			       spinlock_t *lock)
4441 {
4442 	u32 next_id = attr->start_id;
4443 	int err = 0;
4444 
4445 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4446 		return -EINVAL;
4447 
4448 	if (!capable(CAP_SYS_ADMIN))
4449 		return -EPERM;
4450 
4451 	next_id++;
4452 	spin_lock_bh(lock);
4453 	if (!idr_get_next(idr, &next_id))
4454 		err = -ENOENT;
4455 	spin_unlock_bh(lock);
4456 
4457 	if (!err)
4458 		err = put_user(next_id, &uattr->next_id);
4459 
4460 	return err;
4461 }
4462 
bpf_map_get_curr_or_next(u32 * id)4463 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4464 {
4465 	struct bpf_map *map;
4466 
4467 	spin_lock_bh(&map_idr_lock);
4468 again:
4469 	map = idr_get_next(&map_idr, id);
4470 	if (map) {
4471 		map = __bpf_map_inc_not_zero(map, false);
4472 		if (IS_ERR(map)) {
4473 			(*id)++;
4474 			goto again;
4475 		}
4476 	}
4477 	spin_unlock_bh(&map_idr_lock);
4478 
4479 	return map;
4480 }
4481 
bpf_prog_get_curr_or_next(u32 * id)4482 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4483 {
4484 	struct bpf_prog *prog;
4485 
4486 	spin_lock_bh(&prog_idr_lock);
4487 again:
4488 	prog = idr_get_next(&prog_idr, id);
4489 	if (prog) {
4490 		prog = bpf_prog_inc_not_zero(prog);
4491 		if (IS_ERR(prog)) {
4492 			(*id)++;
4493 			goto again;
4494 		}
4495 	}
4496 	spin_unlock_bh(&prog_idr_lock);
4497 
4498 	return prog;
4499 }
4500 
4501 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4502 
bpf_prog_by_id(u32 id)4503 struct bpf_prog *bpf_prog_by_id(u32 id)
4504 {
4505 	struct bpf_prog *prog;
4506 
4507 	if (!id)
4508 		return ERR_PTR(-ENOENT);
4509 
4510 	spin_lock_bh(&prog_idr_lock);
4511 	prog = idr_find(&prog_idr, id);
4512 	if (prog)
4513 		prog = bpf_prog_inc_not_zero(prog);
4514 	else
4515 		prog = ERR_PTR(-ENOENT);
4516 	spin_unlock_bh(&prog_idr_lock);
4517 	return prog;
4518 }
4519 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4520 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4521 {
4522 	struct bpf_prog *prog;
4523 	u32 id = attr->prog_id;
4524 	int fd;
4525 
4526 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4527 		return -EINVAL;
4528 
4529 	if (!capable(CAP_SYS_ADMIN))
4530 		return -EPERM;
4531 
4532 	prog = bpf_prog_by_id(id);
4533 	if (IS_ERR(prog))
4534 		return PTR_ERR(prog);
4535 
4536 	fd = bpf_prog_new_fd(prog);
4537 	if (fd < 0)
4538 		bpf_prog_put(prog);
4539 
4540 	return fd;
4541 }
4542 
4543 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4544 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4545 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4546 {
4547 	struct bpf_map *map;
4548 	u32 id = attr->map_id;
4549 	int f_flags;
4550 	int fd;
4551 
4552 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4553 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4554 		return -EINVAL;
4555 
4556 	if (!capable(CAP_SYS_ADMIN))
4557 		return -EPERM;
4558 
4559 	f_flags = bpf_get_file_flag(attr->open_flags);
4560 	if (f_flags < 0)
4561 		return f_flags;
4562 
4563 	spin_lock_bh(&map_idr_lock);
4564 	map = idr_find(&map_idr, id);
4565 	if (map)
4566 		map = __bpf_map_inc_not_zero(map, true);
4567 	else
4568 		map = ERR_PTR(-ENOENT);
4569 	spin_unlock_bh(&map_idr_lock);
4570 
4571 	if (IS_ERR(map))
4572 		return PTR_ERR(map);
4573 
4574 	fd = bpf_map_new_fd(map, f_flags);
4575 	if (fd < 0)
4576 		bpf_map_put_with_uref(map);
4577 
4578 	return fd;
4579 }
4580 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4581 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4582 					      unsigned long addr, u32 *off,
4583 					      u32 *type)
4584 {
4585 	const struct bpf_map *map;
4586 	int i;
4587 
4588 	mutex_lock(&prog->aux->used_maps_mutex);
4589 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4590 		map = prog->aux->used_maps[i];
4591 		if (map == (void *)addr) {
4592 			*type = BPF_PSEUDO_MAP_FD;
4593 			goto out;
4594 		}
4595 		if (!map->ops->map_direct_value_meta)
4596 			continue;
4597 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4598 			*type = BPF_PSEUDO_MAP_VALUE;
4599 			goto out;
4600 		}
4601 	}
4602 	map = NULL;
4603 
4604 out:
4605 	mutex_unlock(&prog->aux->used_maps_mutex);
4606 	return map;
4607 }
4608 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4609 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4610 					      const struct cred *f_cred)
4611 {
4612 	const struct bpf_map *map;
4613 	struct bpf_insn *insns;
4614 	u32 off, type;
4615 	u64 imm;
4616 	u8 code;
4617 	int i;
4618 
4619 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4620 			GFP_USER);
4621 	if (!insns)
4622 		return insns;
4623 
4624 	for (i = 0; i < prog->len; i++) {
4625 		code = insns[i].code;
4626 
4627 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4628 			insns[i].code = BPF_JMP | BPF_CALL;
4629 			insns[i].imm = BPF_FUNC_tail_call;
4630 			/* fall-through */
4631 		}
4632 		if (code == (BPF_JMP | BPF_CALL) ||
4633 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4634 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4635 				insns[i].code = BPF_JMP | BPF_CALL;
4636 			if (!bpf_dump_raw_ok(f_cred))
4637 				insns[i].imm = 0;
4638 			continue;
4639 		}
4640 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4641 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4642 			continue;
4643 		}
4644 
4645 		if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4646 		     BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4647 			insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4648 			continue;
4649 		}
4650 
4651 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4652 			continue;
4653 
4654 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4655 		map = bpf_map_from_imm(prog, imm, &off, &type);
4656 		if (map) {
4657 			insns[i].src_reg = type;
4658 			insns[i].imm = map->id;
4659 			insns[i + 1].imm = off;
4660 			continue;
4661 		}
4662 	}
4663 
4664 	return insns;
4665 }
4666 
set_info_rec_size(struct bpf_prog_info * info)4667 static int set_info_rec_size(struct bpf_prog_info *info)
4668 {
4669 	/*
4670 	 * Ensure info.*_rec_size is the same as kernel expected size
4671 	 *
4672 	 * or
4673 	 *
4674 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4675 	 * zero.  In this case, the kernel will set the expected
4676 	 * _rec_size back to the info.
4677 	 */
4678 
4679 	if ((info->nr_func_info || info->func_info_rec_size) &&
4680 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4681 		return -EINVAL;
4682 
4683 	if ((info->nr_line_info || info->line_info_rec_size) &&
4684 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
4685 		return -EINVAL;
4686 
4687 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4688 	    info->jited_line_info_rec_size != sizeof(__u64))
4689 		return -EINVAL;
4690 
4691 	info->func_info_rec_size = sizeof(struct bpf_func_info);
4692 	info->line_info_rec_size = sizeof(struct bpf_line_info);
4693 	info->jited_line_info_rec_size = sizeof(__u64);
4694 
4695 	return 0;
4696 }
4697 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4698 static int bpf_prog_get_info_by_fd(struct file *file,
4699 				   struct bpf_prog *prog,
4700 				   const union bpf_attr *attr,
4701 				   union bpf_attr __user *uattr)
4702 {
4703 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4704 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4705 	struct bpf_prog_info info;
4706 	u32 info_len = attr->info.info_len;
4707 	struct bpf_prog_kstats stats;
4708 	char __user *uinsns;
4709 	u32 ulen;
4710 	int err;
4711 
4712 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4713 	if (err)
4714 		return err;
4715 	info_len = min_t(u32, sizeof(info), info_len);
4716 
4717 	memset(&info, 0, sizeof(info));
4718 	if (copy_from_user(&info, uinfo, info_len))
4719 		return -EFAULT;
4720 
4721 	info.type = prog->type;
4722 	info.id = prog->aux->id;
4723 	info.load_time = prog->aux->load_time;
4724 	info.created_by_uid = from_kuid_munged(current_user_ns(),
4725 					       prog->aux->user->uid);
4726 	info.gpl_compatible = prog->gpl_compatible;
4727 
4728 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
4729 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
4730 
4731 	mutex_lock(&prog->aux->used_maps_mutex);
4732 	ulen = info.nr_map_ids;
4733 	info.nr_map_ids = prog->aux->used_map_cnt;
4734 	ulen = min_t(u32, info.nr_map_ids, ulen);
4735 	if (ulen) {
4736 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
4737 		u32 i;
4738 
4739 		for (i = 0; i < ulen; i++)
4740 			if (put_user(prog->aux->used_maps[i]->id,
4741 				     &user_map_ids[i])) {
4742 				mutex_unlock(&prog->aux->used_maps_mutex);
4743 				return -EFAULT;
4744 			}
4745 	}
4746 	mutex_unlock(&prog->aux->used_maps_mutex);
4747 
4748 	err = set_info_rec_size(&info);
4749 	if (err)
4750 		return err;
4751 
4752 	bpf_prog_get_stats(prog, &stats);
4753 	info.run_time_ns = stats.nsecs;
4754 	info.run_cnt = stats.cnt;
4755 	info.recursion_misses = stats.misses;
4756 
4757 	info.verified_insns = prog->aux->verified_insns;
4758 	if (prog->aux->btf)
4759 		info.btf_id = btf_obj_id(prog->aux->btf);
4760 
4761 	if (!bpf_capable()) {
4762 		info.jited_prog_len = 0;
4763 		info.xlated_prog_len = 0;
4764 		info.nr_jited_ksyms = 0;
4765 		info.nr_jited_func_lens = 0;
4766 		info.nr_func_info = 0;
4767 		info.nr_line_info = 0;
4768 		info.nr_jited_line_info = 0;
4769 		goto done;
4770 	}
4771 
4772 	ulen = info.xlated_prog_len;
4773 	info.xlated_prog_len = bpf_prog_insn_size(prog);
4774 	if (info.xlated_prog_len && ulen) {
4775 		struct bpf_insn *insns_sanitized;
4776 		bool fault;
4777 
4778 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
4779 			info.xlated_prog_insns = 0;
4780 			goto done;
4781 		}
4782 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
4783 		if (!insns_sanitized)
4784 			return -ENOMEM;
4785 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
4786 		ulen = min_t(u32, info.xlated_prog_len, ulen);
4787 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
4788 		kfree(insns_sanitized);
4789 		if (fault)
4790 			return -EFAULT;
4791 	}
4792 
4793 	if (bpf_prog_is_offloaded(prog->aux)) {
4794 		err = bpf_prog_offload_info_fill(&info, prog);
4795 		if (err)
4796 			return err;
4797 		goto done;
4798 	}
4799 
4800 	/* NOTE: the following code is supposed to be skipped for offload.
4801 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
4802 	 * for offload.
4803 	 */
4804 	ulen = info.jited_prog_len;
4805 	if (prog->aux->func_cnt) {
4806 		u32 i;
4807 
4808 		info.jited_prog_len = 0;
4809 		for (i = 0; i < prog->aux->func_cnt; i++)
4810 			info.jited_prog_len += prog->aux->func[i]->jited_len;
4811 	} else {
4812 		info.jited_prog_len = prog->jited_len;
4813 	}
4814 
4815 	if (info.jited_prog_len && ulen) {
4816 		if (bpf_dump_raw_ok(file->f_cred)) {
4817 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
4818 			ulen = min_t(u32, info.jited_prog_len, ulen);
4819 
4820 			/* for multi-function programs, copy the JITed
4821 			 * instructions for all the functions
4822 			 */
4823 			if (prog->aux->func_cnt) {
4824 				u32 len, free, i;
4825 				u8 *img;
4826 
4827 				free = ulen;
4828 				for (i = 0; i < prog->aux->func_cnt; i++) {
4829 					len = prog->aux->func[i]->jited_len;
4830 					len = min_t(u32, len, free);
4831 					img = (u8 *) prog->aux->func[i]->bpf_func;
4832 					if (copy_to_user(uinsns, img, len))
4833 						return -EFAULT;
4834 					uinsns += len;
4835 					free -= len;
4836 					if (!free)
4837 						break;
4838 				}
4839 			} else {
4840 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
4841 					return -EFAULT;
4842 			}
4843 		} else {
4844 			info.jited_prog_insns = 0;
4845 		}
4846 	}
4847 
4848 	ulen = info.nr_jited_ksyms;
4849 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4850 	if (ulen) {
4851 		if (bpf_dump_raw_ok(file->f_cred)) {
4852 			unsigned long ksym_addr;
4853 			u64 __user *user_ksyms;
4854 			u32 i;
4855 
4856 			/* copy the address of the kernel symbol
4857 			 * corresponding to each function
4858 			 */
4859 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4860 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4861 			if (prog->aux->func_cnt) {
4862 				for (i = 0; i < ulen; i++) {
4863 					ksym_addr = (unsigned long)
4864 						prog->aux->func[i]->bpf_func;
4865 					if (put_user((u64) ksym_addr,
4866 						     &user_ksyms[i]))
4867 						return -EFAULT;
4868 				}
4869 			} else {
4870 				ksym_addr = (unsigned long) prog->bpf_func;
4871 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
4872 					return -EFAULT;
4873 			}
4874 		} else {
4875 			info.jited_ksyms = 0;
4876 		}
4877 	}
4878 
4879 	ulen = info.nr_jited_func_lens;
4880 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4881 	if (ulen) {
4882 		if (bpf_dump_raw_ok(file->f_cred)) {
4883 			u32 __user *user_lens;
4884 			u32 func_len, i;
4885 
4886 			/* copy the JITed image lengths for each function */
4887 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4888 			user_lens = u64_to_user_ptr(info.jited_func_lens);
4889 			if (prog->aux->func_cnt) {
4890 				for (i = 0; i < ulen; i++) {
4891 					func_len =
4892 						prog->aux->func[i]->jited_len;
4893 					if (put_user(func_len, &user_lens[i]))
4894 						return -EFAULT;
4895 				}
4896 			} else {
4897 				func_len = prog->jited_len;
4898 				if (put_user(func_len, &user_lens[0]))
4899 					return -EFAULT;
4900 			}
4901 		} else {
4902 			info.jited_func_lens = 0;
4903 		}
4904 	}
4905 
4906 	info.attach_btf_id = prog->aux->attach_btf_id;
4907 	if (attach_btf)
4908 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
4909 
4910 	ulen = info.nr_func_info;
4911 	info.nr_func_info = prog->aux->func_info_cnt;
4912 	if (info.nr_func_info && ulen) {
4913 		char __user *user_finfo;
4914 
4915 		user_finfo = u64_to_user_ptr(info.func_info);
4916 		ulen = min_t(u32, info.nr_func_info, ulen);
4917 		if (copy_to_user(user_finfo, prog->aux->func_info,
4918 				 info.func_info_rec_size * ulen))
4919 			return -EFAULT;
4920 	}
4921 
4922 	ulen = info.nr_line_info;
4923 	info.nr_line_info = prog->aux->nr_linfo;
4924 	if (info.nr_line_info && ulen) {
4925 		__u8 __user *user_linfo;
4926 
4927 		user_linfo = u64_to_user_ptr(info.line_info);
4928 		ulen = min_t(u32, info.nr_line_info, ulen);
4929 		if (copy_to_user(user_linfo, prog->aux->linfo,
4930 				 info.line_info_rec_size * ulen))
4931 			return -EFAULT;
4932 	}
4933 
4934 	ulen = info.nr_jited_line_info;
4935 	if (prog->aux->jited_linfo)
4936 		info.nr_jited_line_info = prog->aux->nr_linfo;
4937 	else
4938 		info.nr_jited_line_info = 0;
4939 	if (info.nr_jited_line_info && ulen) {
4940 		if (bpf_dump_raw_ok(file->f_cred)) {
4941 			unsigned long line_addr;
4942 			__u64 __user *user_linfo;
4943 			u32 i;
4944 
4945 			user_linfo = u64_to_user_ptr(info.jited_line_info);
4946 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
4947 			for (i = 0; i < ulen; i++) {
4948 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
4949 				if (put_user((__u64)line_addr, &user_linfo[i]))
4950 					return -EFAULT;
4951 			}
4952 		} else {
4953 			info.jited_line_info = 0;
4954 		}
4955 	}
4956 
4957 	ulen = info.nr_prog_tags;
4958 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4959 	if (ulen) {
4960 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4961 		u32 i;
4962 
4963 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
4964 		ulen = min_t(u32, info.nr_prog_tags, ulen);
4965 		if (prog->aux->func_cnt) {
4966 			for (i = 0; i < ulen; i++) {
4967 				if (copy_to_user(user_prog_tags[i],
4968 						 prog->aux->func[i]->tag,
4969 						 BPF_TAG_SIZE))
4970 					return -EFAULT;
4971 			}
4972 		} else {
4973 			if (copy_to_user(user_prog_tags[0],
4974 					 prog->tag, BPF_TAG_SIZE))
4975 				return -EFAULT;
4976 		}
4977 	}
4978 
4979 done:
4980 	if (copy_to_user(uinfo, &info, info_len) ||
4981 	    put_user(info_len, &uattr->info.info_len))
4982 		return -EFAULT;
4983 
4984 	return 0;
4985 }
4986 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4987 static int bpf_map_get_info_by_fd(struct file *file,
4988 				  struct bpf_map *map,
4989 				  const union bpf_attr *attr,
4990 				  union bpf_attr __user *uattr)
4991 {
4992 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4993 	struct bpf_map_info info;
4994 	u32 info_len = attr->info.info_len;
4995 	int err;
4996 
4997 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4998 	if (err)
4999 		return err;
5000 	info_len = min_t(u32, sizeof(info), info_len);
5001 
5002 	memset(&info, 0, sizeof(info));
5003 	info.type = map->map_type;
5004 	info.id = map->id;
5005 	info.key_size = map->key_size;
5006 	info.value_size = map->value_size;
5007 	info.max_entries = map->max_entries;
5008 	info.map_flags = map->map_flags;
5009 	info.map_extra = map->map_extra;
5010 	memcpy(info.name, map->name, sizeof(map->name));
5011 
5012 	if (map->btf) {
5013 		info.btf_id = btf_obj_id(map->btf);
5014 		info.btf_key_type_id = map->btf_key_type_id;
5015 		info.btf_value_type_id = map->btf_value_type_id;
5016 	}
5017 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5018 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5019 		bpf_map_struct_ops_info_fill(&info, map);
5020 
5021 	if (bpf_map_is_offloaded(map)) {
5022 		err = bpf_map_offload_info_fill(&info, map);
5023 		if (err)
5024 			return err;
5025 	}
5026 
5027 	if (copy_to_user(uinfo, &info, info_len) ||
5028 	    put_user(info_len, &uattr->info.info_len))
5029 		return -EFAULT;
5030 
5031 	return 0;
5032 }
5033 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5034 static int bpf_btf_get_info_by_fd(struct file *file,
5035 				  struct btf *btf,
5036 				  const union bpf_attr *attr,
5037 				  union bpf_attr __user *uattr)
5038 {
5039 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5040 	u32 info_len = attr->info.info_len;
5041 	int err;
5042 
5043 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5044 	if (err)
5045 		return err;
5046 
5047 	return btf_get_info_by_fd(btf, attr, uattr);
5048 }
5049 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5050 static int bpf_link_get_info_by_fd(struct file *file,
5051 				  struct bpf_link *link,
5052 				  const union bpf_attr *attr,
5053 				  union bpf_attr __user *uattr)
5054 {
5055 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5056 	struct bpf_link_info info;
5057 	u32 info_len = attr->info.info_len;
5058 	int err;
5059 
5060 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5061 	if (err)
5062 		return err;
5063 	info_len = min_t(u32, sizeof(info), info_len);
5064 
5065 	memset(&info, 0, sizeof(info));
5066 	if (copy_from_user(&info, uinfo, info_len))
5067 		return -EFAULT;
5068 
5069 	info.type = link->type;
5070 	info.id = link->id;
5071 	if (link->prog)
5072 		info.prog_id = link->prog->aux->id;
5073 
5074 	if (link->ops->fill_link_info) {
5075 		err = link->ops->fill_link_info(link, &info);
5076 		if (err)
5077 			return err;
5078 	}
5079 
5080 	if (copy_to_user(uinfo, &info, info_len) ||
5081 	    put_user(info_len, &uattr->info.info_len))
5082 		return -EFAULT;
5083 
5084 	return 0;
5085 }
5086 
5087 
5088 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5089 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5090 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5091 				  union bpf_attr __user *uattr)
5092 {
5093 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5094 		return -EINVAL;
5095 
5096 	CLASS(fd, f)(attr->info.bpf_fd);
5097 	if (fd_empty(f))
5098 		return -EBADFD;
5099 
5100 	if (fd_file(f)->f_op == &bpf_prog_fops)
5101 		return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5102 					      uattr);
5103 	else if (fd_file(f)->f_op == &bpf_map_fops)
5104 		return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5105 					     uattr);
5106 	else if (fd_file(f)->f_op == &btf_fops)
5107 		return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5108 	else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5109 		return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5110 					      attr, uattr);
5111 	return -EINVAL;
5112 }
5113 
5114 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5115 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5116 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5117 {
5118 	struct bpf_token *token = NULL;
5119 
5120 	if (CHECK_ATTR(BPF_BTF_LOAD))
5121 		return -EINVAL;
5122 
5123 	if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5124 		return -EINVAL;
5125 
5126 	if (attr->btf_flags & BPF_F_TOKEN_FD) {
5127 		token = bpf_token_get_from_fd(attr->btf_token_fd);
5128 		if (IS_ERR(token))
5129 			return PTR_ERR(token);
5130 		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5131 			bpf_token_put(token);
5132 			token = NULL;
5133 		}
5134 	}
5135 
5136 	if (!bpf_token_capable(token, CAP_BPF)) {
5137 		bpf_token_put(token);
5138 		return -EPERM;
5139 	}
5140 
5141 	bpf_token_put(token);
5142 
5143 	return btf_new_fd(attr, uattr, uattr_size);
5144 }
5145 
5146 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5147 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5148 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5149 {
5150 	struct bpf_token *token = NULL;
5151 
5152 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5153 		return -EINVAL;
5154 
5155 	if (attr->open_flags & ~BPF_F_TOKEN_FD)
5156 		return -EINVAL;
5157 
5158 	if (attr->open_flags & BPF_F_TOKEN_FD) {
5159 		token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5160 		if (IS_ERR(token))
5161 			return PTR_ERR(token);
5162 		if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5163 			bpf_token_put(token);
5164 			token = NULL;
5165 		}
5166 	}
5167 
5168 	if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5169 		bpf_token_put(token);
5170 		return -EPERM;
5171 	}
5172 
5173 	bpf_token_put(token);
5174 
5175 	return btf_get_fd_by_id(attr->btf_id);
5176 }
5177 
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)5178 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5179 				    union bpf_attr __user *uattr,
5180 				    u32 prog_id, u32 fd_type,
5181 				    const char *buf, u64 probe_offset,
5182 				    u64 probe_addr)
5183 {
5184 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5185 	u32 len = buf ? strlen(buf) : 0, input_len;
5186 	int err = 0;
5187 
5188 	if (put_user(len, &uattr->task_fd_query.buf_len))
5189 		return -EFAULT;
5190 	input_len = attr->task_fd_query.buf_len;
5191 	if (input_len && ubuf) {
5192 		if (!len) {
5193 			/* nothing to copy, just make ubuf NULL terminated */
5194 			char zero = '\0';
5195 
5196 			if (put_user(zero, ubuf))
5197 				return -EFAULT;
5198 		} else if (input_len >= len + 1) {
5199 			/* ubuf can hold the string with NULL terminator */
5200 			if (copy_to_user(ubuf, buf, len + 1))
5201 				return -EFAULT;
5202 		} else {
5203 			/* ubuf cannot hold the string with NULL terminator,
5204 			 * do a partial copy with NULL terminator.
5205 			 */
5206 			char zero = '\0';
5207 
5208 			err = -ENOSPC;
5209 			if (copy_to_user(ubuf, buf, input_len - 1))
5210 				return -EFAULT;
5211 			if (put_user(zero, ubuf + input_len - 1))
5212 				return -EFAULT;
5213 		}
5214 	}
5215 
5216 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5217 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5218 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5219 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5220 		return -EFAULT;
5221 
5222 	return err;
5223 }
5224 
5225 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5226 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5227 static int bpf_task_fd_query(const union bpf_attr *attr,
5228 			     union bpf_attr __user *uattr)
5229 {
5230 	pid_t pid = attr->task_fd_query.pid;
5231 	u32 fd = attr->task_fd_query.fd;
5232 	const struct perf_event *event;
5233 	struct task_struct *task;
5234 	struct file *file;
5235 	int err;
5236 
5237 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5238 		return -EINVAL;
5239 
5240 	if (!capable(CAP_SYS_ADMIN))
5241 		return -EPERM;
5242 
5243 	if (attr->task_fd_query.flags != 0)
5244 		return -EINVAL;
5245 
5246 	rcu_read_lock();
5247 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5248 	rcu_read_unlock();
5249 	if (!task)
5250 		return -ENOENT;
5251 
5252 	err = 0;
5253 	file = fget_task(task, fd);
5254 	put_task_struct(task);
5255 	if (!file)
5256 		return -EBADF;
5257 
5258 	if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5259 		struct bpf_link *link = file->private_data;
5260 
5261 		if (link->ops == &bpf_raw_tp_link_lops) {
5262 			struct bpf_raw_tp_link *raw_tp =
5263 				container_of(link, struct bpf_raw_tp_link, link);
5264 			struct bpf_raw_event_map *btp = raw_tp->btp;
5265 
5266 			err = bpf_task_fd_query_copy(attr, uattr,
5267 						     raw_tp->link.prog->aux->id,
5268 						     BPF_FD_TYPE_RAW_TRACEPOINT,
5269 						     btp->tp->name, 0, 0);
5270 			goto put_file;
5271 		}
5272 		goto out_not_supp;
5273 	}
5274 
5275 	event = perf_get_event(file);
5276 	if (!IS_ERR(event)) {
5277 		u64 probe_offset, probe_addr;
5278 		u32 prog_id, fd_type;
5279 		const char *buf;
5280 
5281 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5282 					      &buf, &probe_offset,
5283 					      &probe_addr, NULL);
5284 		if (!err)
5285 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5286 						     fd_type, buf,
5287 						     probe_offset,
5288 						     probe_addr);
5289 		goto put_file;
5290 	}
5291 
5292 out_not_supp:
5293 	err = -ENOTSUPP;
5294 put_file:
5295 	fput(file);
5296 	return err;
5297 }
5298 
5299 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5300 
5301 #define BPF_DO_BATCH(fn, ...)			\
5302 	do {					\
5303 		if (!fn) {			\
5304 			err = -ENOTSUPP;	\
5305 			goto err_put;		\
5306 		}				\
5307 		err = fn(__VA_ARGS__);		\
5308 	} while (0)
5309 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5310 static int bpf_map_do_batch(const union bpf_attr *attr,
5311 			    union bpf_attr __user *uattr,
5312 			    int cmd)
5313 {
5314 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
5315 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5316 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5317 	struct bpf_map *map;
5318 	int err;
5319 
5320 	if (CHECK_ATTR(BPF_MAP_BATCH))
5321 		return -EINVAL;
5322 
5323 	CLASS(fd, f)(attr->batch.map_fd);
5324 
5325 	map = __bpf_map_get(f);
5326 	if (IS_ERR(map))
5327 		return PTR_ERR(map);
5328 	if (has_write)
5329 		bpf_map_write_active_inc(map);
5330 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5331 		err = -EPERM;
5332 		goto err_put;
5333 	}
5334 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5335 		err = -EPERM;
5336 		goto err_put;
5337 	}
5338 
5339 	if (cmd == BPF_MAP_LOOKUP_BATCH)
5340 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5341 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5342 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5343 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5344 		BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5345 	else
5346 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5347 err_put:
5348 	if (has_write) {
5349 		maybe_wait_bpf_programs(map);
5350 		bpf_map_write_active_dec(map);
5351 	}
5352 	return err;
5353 }
5354 
5355 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5356 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5357 {
5358 	struct bpf_prog *prog;
5359 	int ret;
5360 
5361 	if (CHECK_ATTR(BPF_LINK_CREATE))
5362 		return -EINVAL;
5363 
5364 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5365 		return bpf_struct_ops_link_create(attr);
5366 
5367 	prog = bpf_prog_get(attr->link_create.prog_fd);
5368 	if (IS_ERR(prog))
5369 		return PTR_ERR(prog);
5370 
5371 	ret = bpf_prog_attach_check_attach_type(prog,
5372 						attr->link_create.attach_type);
5373 	if (ret)
5374 		goto out;
5375 
5376 	switch (prog->type) {
5377 	case BPF_PROG_TYPE_CGROUP_SKB:
5378 	case BPF_PROG_TYPE_CGROUP_SOCK:
5379 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5380 	case BPF_PROG_TYPE_SOCK_OPS:
5381 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5382 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5383 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5384 		ret = cgroup_bpf_link_attach(attr, prog);
5385 		break;
5386 	case BPF_PROG_TYPE_EXT:
5387 		ret = bpf_tracing_prog_attach(prog,
5388 					      attr->link_create.target_fd,
5389 					      attr->link_create.target_btf_id,
5390 					      attr->link_create.tracing.cookie);
5391 		break;
5392 	case BPF_PROG_TYPE_LSM:
5393 	case BPF_PROG_TYPE_TRACING:
5394 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5395 			ret = -EINVAL;
5396 			goto out;
5397 		}
5398 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5399 			ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie);
5400 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5401 			ret = bpf_iter_link_attach(attr, uattr, prog);
5402 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5403 			ret = cgroup_bpf_link_attach(attr, prog);
5404 		else
5405 			ret = bpf_tracing_prog_attach(prog,
5406 						      attr->link_create.target_fd,
5407 						      attr->link_create.target_btf_id,
5408 						      attr->link_create.tracing.cookie);
5409 		break;
5410 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5411 	case BPF_PROG_TYPE_SK_LOOKUP:
5412 		ret = netns_bpf_link_create(attr, prog);
5413 		break;
5414 	case BPF_PROG_TYPE_SK_MSG:
5415 	case BPF_PROG_TYPE_SK_SKB:
5416 		ret = sock_map_link_create(attr, prog);
5417 		break;
5418 #ifdef CONFIG_NET
5419 	case BPF_PROG_TYPE_XDP:
5420 		ret = bpf_xdp_link_attach(attr, prog);
5421 		break;
5422 	case BPF_PROG_TYPE_SCHED_CLS:
5423 		if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5424 		    attr->link_create.attach_type == BPF_TCX_EGRESS)
5425 			ret = tcx_link_attach(attr, prog);
5426 		else
5427 			ret = netkit_link_attach(attr, prog);
5428 		break;
5429 	case BPF_PROG_TYPE_NETFILTER:
5430 		ret = bpf_nf_link_attach(attr, prog);
5431 		break;
5432 #endif
5433 	case BPF_PROG_TYPE_PERF_EVENT:
5434 	case BPF_PROG_TYPE_TRACEPOINT:
5435 		ret = bpf_perf_link_attach(attr, prog);
5436 		break;
5437 	case BPF_PROG_TYPE_KPROBE:
5438 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5439 			ret = bpf_perf_link_attach(attr, prog);
5440 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5441 			 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5442 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5443 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5444 			 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5445 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5446 		break;
5447 	default:
5448 		ret = -EINVAL;
5449 	}
5450 
5451 out:
5452 	if (ret < 0)
5453 		bpf_prog_put(prog);
5454 	return ret;
5455 }
5456 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5457 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5458 {
5459 	struct bpf_map *new_map, *old_map = NULL;
5460 	int ret;
5461 
5462 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5463 	if (IS_ERR(new_map))
5464 		return PTR_ERR(new_map);
5465 
5466 	if (attr->link_update.flags & BPF_F_REPLACE) {
5467 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5468 		if (IS_ERR(old_map)) {
5469 			ret = PTR_ERR(old_map);
5470 			goto out_put;
5471 		}
5472 	} else if (attr->link_update.old_map_fd) {
5473 		ret = -EINVAL;
5474 		goto out_put;
5475 	}
5476 
5477 	ret = link->ops->update_map(link, new_map, old_map);
5478 
5479 	if (old_map)
5480 		bpf_map_put(old_map);
5481 out_put:
5482 	bpf_map_put(new_map);
5483 	return ret;
5484 }
5485 
5486 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5487 
link_update(union bpf_attr * attr)5488 static int link_update(union bpf_attr *attr)
5489 {
5490 	struct bpf_prog *old_prog = NULL, *new_prog;
5491 	struct bpf_link *link;
5492 	u32 flags;
5493 	int ret;
5494 
5495 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5496 		return -EINVAL;
5497 
5498 	flags = attr->link_update.flags;
5499 	if (flags & ~BPF_F_REPLACE)
5500 		return -EINVAL;
5501 
5502 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5503 	if (IS_ERR(link))
5504 		return PTR_ERR(link);
5505 
5506 	if (link->ops->update_map) {
5507 		ret = link_update_map(link, attr);
5508 		goto out_put_link;
5509 	}
5510 
5511 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5512 	if (IS_ERR(new_prog)) {
5513 		ret = PTR_ERR(new_prog);
5514 		goto out_put_link;
5515 	}
5516 
5517 	if (flags & BPF_F_REPLACE) {
5518 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5519 		if (IS_ERR(old_prog)) {
5520 			ret = PTR_ERR(old_prog);
5521 			old_prog = NULL;
5522 			goto out_put_progs;
5523 		}
5524 	} else if (attr->link_update.old_prog_fd) {
5525 		ret = -EINVAL;
5526 		goto out_put_progs;
5527 	}
5528 
5529 	if (link->ops->update_prog)
5530 		ret = link->ops->update_prog(link, new_prog, old_prog);
5531 	else
5532 		ret = -EINVAL;
5533 
5534 out_put_progs:
5535 	if (old_prog)
5536 		bpf_prog_put(old_prog);
5537 	if (ret)
5538 		bpf_prog_put(new_prog);
5539 out_put_link:
5540 	bpf_link_put_direct(link);
5541 	return ret;
5542 }
5543 
5544 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5545 
link_detach(union bpf_attr * attr)5546 static int link_detach(union bpf_attr *attr)
5547 {
5548 	struct bpf_link *link;
5549 	int ret;
5550 
5551 	if (CHECK_ATTR(BPF_LINK_DETACH))
5552 		return -EINVAL;
5553 
5554 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5555 	if (IS_ERR(link))
5556 		return PTR_ERR(link);
5557 
5558 	if (link->ops->detach)
5559 		ret = link->ops->detach(link);
5560 	else
5561 		ret = -EOPNOTSUPP;
5562 
5563 	bpf_link_put_direct(link);
5564 	return ret;
5565 }
5566 
bpf_link_inc_not_zero(struct bpf_link * link)5567 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5568 {
5569 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5570 }
5571 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5572 
bpf_link_by_id(u32 id)5573 struct bpf_link *bpf_link_by_id(u32 id)
5574 {
5575 	struct bpf_link *link;
5576 
5577 	if (!id)
5578 		return ERR_PTR(-ENOENT);
5579 
5580 	spin_lock_bh(&link_idr_lock);
5581 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5582 	link = idr_find(&link_idr, id);
5583 	if (link) {
5584 		if (link->id)
5585 			link = bpf_link_inc_not_zero(link);
5586 		else
5587 			link = ERR_PTR(-EAGAIN);
5588 	} else {
5589 		link = ERR_PTR(-ENOENT);
5590 	}
5591 	spin_unlock_bh(&link_idr_lock);
5592 	return link;
5593 }
5594 
bpf_link_get_curr_or_next(u32 * id)5595 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5596 {
5597 	struct bpf_link *link;
5598 
5599 	spin_lock_bh(&link_idr_lock);
5600 again:
5601 	link = idr_get_next(&link_idr, id);
5602 	if (link) {
5603 		link = bpf_link_inc_not_zero(link);
5604 		if (IS_ERR(link)) {
5605 			(*id)++;
5606 			goto again;
5607 		}
5608 	}
5609 	spin_unlock_bh(&link_idr_lock);
5610 
5611 	return link;
5612 }
5613 
5614 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5615 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5616 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5617 {
5618 	struct bpf_link *link;
5619 	u32 id = attr->link_id;
5620 	int fd;
5621 
5622 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5623 		return -EINVAL;
5624 
5625 	if (!capable(CAP_SYS_ADMIN))
5626 		return -EPERM;
5627 
5628 	link = bpf_link_by_id(id);
5629 	if (IS_ERR(link))
5630 		return PTR_ERR(link);
5631 
5632 	fd = bpf_link_new_fd(link);
5633 	if (fd < 0)
5634 		bpf_link_put_direct(link);
5635 
5636 	return fd;
5637 }
5638 
5639 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5640 
bpf_stats_release(struct inode * inode,struct file * file)5641 static int bpf_stats_release(struct inode *inode, struct file *file)
5642 {
5643 	mutex_lock(&bpf_stats_enabled_mutex);
5644 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5645 	mutex_unlock(&bpf_stats_enabled_mutex);
5646 	return 0;
5647 }
5648 
5649 static const struct file_operations bpf_stats_fops = {
5650 	.release = bpf_stats_release,
5651 };
5652 
bpf_enable_runtime_stats(void)5653 static int bpf_enable_runtime_stats(void)
5654 {
5655 	int fd;
5656 
5657 	mutex_lock(&bpf_stats_enabled_mutex);
5658 
5659 	/* Set a very high limit to avoid overflow */
5660 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5661 		mutex_unlock(&bpf_stats_enabled_mutex);
5662 		return -EBUSY;
5663 	}
5664 
5665 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5666 	if (fd >= 0)
5667 		static_key_slow_inc(&bpf_stats_enabled_key.key);
5668 
5669 	mutex_unlock(&bpf_stats_enabled_mutex);
5670 	return fd;
5671 }
5672 
5673 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5674 
bpf_enable_stats(union bpf_attr * attr)5675 static int bpf_enable_stats(union bpf_attr *attr)
5676 {
5677 
5678 	if (CHECK_ATTR(BPF_ENABLE_STATS))
5679 		return -EINVAL;
5680 
5681 	if (!capable(CAP_SYS_ADMIN))
5682 		return -EPERM;
5683 
5684 	switch (attr->enable_stats.type) {
5685 	case BPF_STATS_RUN_TIME:
5686 		return bpf_enable_runtime_stats();
5687 	default:
5688 		break;
5689 	}
5690 	return -EINVAL;
5691 }
5692 
5693 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
5694 
bpf_iter_create(union bpf_attr * attr)5695 static int bpf_iter_create(union bpf_attr *attr)
5696 {
5697 	struct bpf_link *link;
5698 	int err;
5699 
5700 	if (CHECK_ATTR(BPF_ITER_CREATE))
5701 		return -EINVAL;
5702 
5703 	if (attr->iter_create.flags)
5704 		return -EINVAL;
5705 
5706 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
5707 	if (IS_ERR(link))
5708 		return PTR_ERR(link);
5709 
5710 	err = bpf_iter_new_fd(link);
5711 	bpf_link_put_direct(link);
5712 
5713 	return err;
5714 }
5715 
5716 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
5717 
bpf_prog_bind_map(union bpf_attr * attr)5718 static int bpf_prog_bind_map(union bpf_attr *attr)
5719 {
5720 	struct bpf_prog *prog;
5721 	struct bpf_map *map;
5722 	struct bpf_map **used_maps_old, **used_maps_new;
5723 	int i, ret = 0;
5724 
5725 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
5726 		return -EINVAL;
5727 
5728 	if (attr->prog_bind_map.flags)
5729 		return -EINVAL;
5730 
5731 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
5732 	if (IS_ERR(prog))
5733 		return PTR_ERR(prog);
5734 
5735 	map = bpf_map_get(attr->prog_bind_map.map_fd);
5736 	if (IS_ERR(map)) {
5737 		ret = PTR_ERR(map);
5738 		goto out_prog_put;
5739 	}
5740 
5741 	mutex_lock(&prog->aux->used_maps_mutex);
5742 
5743 	used_maps_old = prog->aux->used_maps;
5744 
5745 	for (i = 0; i < prog->aux->used_map_cnt; i++)
5746 		if (used_maps_old[i] == map) {
5747 			bpf_map_put(map);
5748 			goto out_unlock;
5749 		}
5750 
5751 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
5752 				      sizeof(used_maps_new[0]),
5753 				      GFP_KERNEL);
5754 	if (!used_maps_new) {
5755 		ret = -ENOMEM;
5756 		goto out_unlock;
5757 	}
5758 
5759 	/* The bpf program will not access the bpf map, but for the sake of
5760 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
5761 	 */
5762 	if (prog->sleepable)
5763 		atomic64_inc(&map->sleepable_refcnt);
5764 	memcpy(used_maps_new, used_maps_old,
5765 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
5766 	used_maps_new[prog->aux->used_map_cnt] = map;
5767 
5768 	prog->aux->used_map_cnt++;
5769 	prog->aux->used_maps = used_maps_new;
5770 
5771 	kfree(used_maps_old);
5772 
5773 out_unlock:
5774 	mutex_unlock(&prog->aux->used_maps_mutex);
5775 
5776 	if (ret)
5777 		bpf_map_put(map);
5778 out_prog_put:
5779 	bpf_prog_put(prog);
5780 	return ret;
5781 }
5782 
5783 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
5784 
token_create(union bpf_attr * attr)5785 static int token_create(union bpf_attr *attr)
5786 {
5787 	if (CHECK_ATTR(BPF_TOKEN_CREATE))
5788 		return -EINVAL;
5789 
5790 	/* no flags are supported yet */
5791 	if (attr->token_create.flags)
5792 		return -EINVAL;
5793 
5794 	return bpf_token_create(attr);
5795 }
5796 
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)5797 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
5798 {
5799 	union bpf_attr attr;
5800 	int err;
5801 
5802 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
5803 	if (err)
5804 		return err;
5805 	size = min_t(u32, size, sizeof(attr));
5806 
5807 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
5808 	memset(&attr, 0, sizeof(attr));
5809 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
5810 		return -EFAULT;
5811 
5812 	err = security_bpf(cmd, &attr, size, uattr.is_kernel);
5813 	if (err < 0)
5814 		return err;
5815 
5816 	switch (cmd) {
5817 	case BPF_MAP_CREATE:
5818 		err = map_create(&attr, uattr.is_kernel);
5819 		break;
5820 	case BPF_MAP_LOOKUP_ELEM:
5821 		err = map_lookup_elem(&attr);
5822 		break;
5823 	case BPF_MAP_UPDATE_ELEM:
5824 		err = map_update_elem(&attr, uattr);
5825 		break;
5826 	case BPF_MAP_DELETE_ELEM:
5827 		err = map_delete_elem(&attr, uattr);
5828 		break;
5829 	case BPF_MAP_GET_NEXT_KEY:
5830 		err = map_get_next_key(&attr);
5831 		break;
5832 	case BPF_MAP_FREEZE:
5833 		err = map_freeze(&attr);
5834 		break;
5835 	case BPF_PROG_LOAD:
5836 		err = bpf_prog_load(&attr, uattr, size);
5837 		break;
5838 	case BPF_OBJ_PIN:
5839 		err = bpf_obj_pin(&attr);
5840 		break;
5841 	case BPF_OBJ_GET:
5842 		err = bpf_obj_get(&attr);
5843 		break;
5844 	case BPF_PROG_ATTACH:
5845 		err = bpf_prog_attach(&attr);
5846 		break;
5847 	case BPF_PROG_DETACH:
5848 		err = bpf_prog_detach(&attr);
5849 		break;
5850 	case BPF_PROG_QUERY:
5851 		err = bpf_prog_query(&attr, uattr.user);
5852 		break;
5853 	case BPF_PROG_TEST_RUN:
5854 		err = bpf_prog_test_run(&attr, uattr.user);
5855 		break;
5856 	case BPF_PROG_GET_NEXT_ID:
5857 		err = bpf_obj_get_next_id(&attr, uattr.user,
5858 					  &prog_idr, &prog_idr_lock);
5859 		break;
5860 	case BPF_MAP_GET_NEXT_ID:
5861 		err = bpf_obj_get_next_id(&attr, uattr.user,
5862 					  &map_idr, &map_idr_lock);
5863 		break;
5864 	case BPF_BTF_GET_NEXT_ID:
5865 		err = bpf_obj_get_next_id(&attr, uattr.user,
5866 					  &btf_idr, &btf_idr_lock);
5867 		break;
5868 	case BPF_PROG_GET_FD_BY_ID:
5869 		err = bpf_prog_get_fd_by_id(&attr);
5870 		break;
5871 	case BPF_MAP_GET_FD_BY_ID:
5872 		err = bpf_map_get_fd_by_id(&attr);
5873 		break;
5874 	case BPF_OBJ_GET_INFO_BY_FD:
5875 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
5876 		break;
5877 	case BPF_RAW_TRACEPOINT_OPEN:
5878 		err = bpf_raw_tracepoint_open(&attr);
5879 		break;
5880 	case BPF_BTF_LOAD:
5881 		err = bpf_btf_load(&attr, uattr, size);
5882 		break;
5883 	case BPF_BTF_GET_FD_BY_ID:
5884 		err = bpf_btf_get_fd_by_id(&attr);
5885 		break;
5886 	case BPF_TASK_FD_QUERY:
5887 		err = bpf_task_fd_query(&attr, uattr.user);
5888 		break;
5889 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
5890 		err = map_lookup_and_delete_elem(&attr);
5891 		break;
5892 	case BPF_MAP_LOOKUP_BATCH:
5893 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
5894 		break;
5895 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
5896 		err = bpf_map_do_batch(&attr, uattr.user,
5897 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
5898 		break;
5899 	case BPF_MAP_UPDATE_BATCH:
5900 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
5901 		break;
5902 	case BPF_MAP_DELETE_BATCH:
5903 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
5904 		break;
5905 	case BPF_LINK_CREATE:
5906 		err = link_create(&attr, uattr);
5907 		break;
5908 	case BPF_LINK_UPDATE:
5909 		err = link_update(&attr);
5910 		break;
5911 	case BPF_LINK_GET_FD_BY_ID:
5912 		err = bpf_link_get_fd_by_id(&attr);
5913 		break;
5914 	case BPF_LINK_GET_NEXT_ID:
5915 		err = bpf_obj_get_next_id(&attr, uattr.user,
5916 					  &link_idr, &link_idr_lock);
5917 		break;
5918 	case BPF_ENABLE_STATS:
5919 		err = bpf_enable_stats(&attr);
5920 		break;
5921 	case BPF_ITER_CREATE:
5922 		err = bpf_iter_create(&attr);
5923 		break;
5924 	case BPF_LINK_DETACH:
5925 		err = link_detach(&attr);
5926 		break;
5927 	case BPF_PROG_BIND_MAP:
5928 		err = bpf_prog_bind_map(&attr);
5929 		break;
5930 	case BPF_TOKEN_CREATE:
5931 		err = token_create(&attr);
5932 		break;
5933 	default:
5934 		err = -EINVAL;
5935 		break;
5936 	}
5937 
5938 	return err;
5939 }
5940 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5941 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5942 {
5943 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5944 }
5945 
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)5946 static bool syscall_prog_is_valid_access(int off, int size,
5947 					 enum bpf_access_type type,
5948 					 const struct bpf_prog *prog,
5949 					 struct bpf_insn_access_aux *info)
5950 {
5951 	if (off < 0 || off >= U16_MAX)
5952 		return false;
5953 	if (off % size != 0)
5954 		return false;
5955 	return true;
5956 }
5957 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5958 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5959 {
5960 	switch (cmd) {
5961 	case BPF_MAP_CREATE:
5962 	case BPF_MAP_DELETE_ELEM:
5963 	case BPF_MAP_UPDATE_ELEM:
5964 	case BPF_MAP_FREEZE:
5965 	case BPF_MAP_GET_FD_BY_ID:
5966 	case BPF_PROG_LOAD:
5967 	case BPF_BTF_LOAD:
5968 	case BPF_LINK_CREATE:
5969 	case BPF_RAW_TRACEPOINT_OPEN:
5970 		break;
5971 	default:
5972 		return -EINVAL;
5973 	}
5974 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5975 }
5976 
5977 
5978 /* To shut up -Wmissing-prototypes.
5979  * This function is used by the kernel light skeleton
5980  * to load bpf programs when modules are loaded or during kernel boot.
5981  * See tools/lib/bpf/skel_internal.h
5982  */
5983 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
5984 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5985 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5986 {
5987 	struct bpf_prog * __maybe_unused prog;
5988 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5989 
5990 	switch (cmd) {
5991 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5992 	case BPF_PROG_TEST_RUN:
5993 		if (attr->test.data_in || attr->test.data_out ||
5994 		    attr->test.ctx_out || attr->test.duration ||
5995 		    attr->test.repeat || attr->test.flags)
5996 			return -EINVAL;
5997 
5998 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5999 		if (IS_ERR(prog))
6000 			return PTR_ERR(prog);
6001 
6002 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6003 		    attr->test.ctx_size_in > U16_MAX) {
6004 			bpf_prog_put(prog);
6005 			return -EINVAL;
6006 		}
6007 
6008 		run_ctx.bpf_cookie = 0;
6009 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6010 			/* recursion detected */
6011 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6012 			bpf_prog_put(prog);
6013 			return -EBUSY;
6014 		}
6015 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6016 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6017 						&run_ctx);
6018 		bpf_prog_put(prog);
6019 		return 0;
6020 #endif
6021 	default:
6022 		return ____bpf_sys_bpf(cmd, attr, size);
6023 	}
6024 }
6025 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL");
6026 
6027 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6028 	.func		= bpf_sys_bpf,
6029 	.gpl_only	= false,
6030 	.ret_type	= RET_INTEGER,
6031 	.arg1_type	= ARG_ANYTHING,
6032 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
6033 	.arg3_type	= ARG_CONST_SIZE,
6034 };
6035 
6036 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6037 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6038 {
6039 	return bpf_base_func_proto(func_id, prog);
6040 }
6041 
BPF_CALL_1(bpf_sys_close,u32,fd)6042 BPF_CALL_1(bpf_sys_close, u32, fd)
6043 {
6044 	/* When bpf program calls this helper there should not be
6045 	 * an fdget() without matching completed fdput().
6046 	 * This helper is allowed in the following callchain only:
6047 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6048 	 */
6049 	return close_fd(fd);
6050 }
6051 
6052 static const struct bpf_func_proto bpf_sys_close_proto = {
6053 	.func		= bpf_sys_close,
6054 	.gpl_only	= false,
6055 	.ret_type	= RET_INTEGER,
6056 	.arg1_type	= ARG_ANYTHING,
6057 };
6058 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6059 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6060 {
6061 	*res = 0;
6062 	if (flags)
6063 		return -EINVAL;
6064 
6065 	if (name_sz <= 1 || name[name_sz - 1])
6066 		return -EINVAL;
6067 
6068 	if (!bpf_dump_raw_ok(current_cred()))
6069 		return -EPERM;
6070 
6071 	*res = kallsyms_lookup_name(name);
6072 	return *res ? 0 : -ENOENT;
6073 }
6074 
6075 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6076 	.func		= bpf_kallsyms_lookup_name,
6077 	.gpl_only	= false,
6078 	.ret_type	= RET_INTEGER,
6079 	.arg1_type	= ARG_PTR_TO_MEM,
6080 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
6081 	.arg3_type	= ARG_ANYTHING,
6082 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6083 	.arg4_size	= sizeof(u64),
6084 };
6085 
6086 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6087 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6088 {
6089 	switch (func_id) {
6090 	case BPF_FUNC_sys_bpf:
6091 		return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6092 		       ? NULL : &bpf_sys_bpf_proto;
6093 	case BPF_FUNC_btf_find_by_name_kind:
6094 		return &bpf_btf_find_by_name_kind_proto;
6095 	case BPF_FUNC_sys_close:
6096 		return &bpf_sys_close_proto;
6097 	case BPF_FUNC_kallsyms_lookup_name:
6098 		return &bpf_kallsyms_lookup_name_proto;
6099 	default:
6100 		return tracing_prog_func_proto(func_id, prog);
6101 	}
6102 }
6103 
6104 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6105 	.get_func_proto  = syscall_prog_func_proto,
6106 	.is_valid_access = syscall_prog_is_valid_access,
6107 };
6108 
6109 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6110 	.test_run = bpf_prog_test_run_syscall,
6111 };
6112 
6113 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6114 static int bpf_stats_handler(const struct ctl_table *table, int write,
6115 			     void *buffer, size_t *lenp, loff_t *ppos)
6116 {
6117 	struct static_key *key = (struct static_key *)table->data;
6118 	static int saved_val;
6119 	int val, ret;
6120 	struct ctl_table tmp = {
6121 		.data   = &val,
6122 		.maxlen = sizeof(val),
6123 		.mode   = table->mode,
6124 		.extra1 = SYSCTL_ZERO,
6125 		.extra2 = SYSCTL_ONE,
6126 	};
6127 
6128 	if (write && !capable(CAP_SYS_ADMIN))
6129 		return -EPERM;
6130 
6131 	mutex_lock(&bpf_stats_enabled_mutex);
6132 	val = saved_val;
6133 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6134 	if (write && !ret && val != saved_val) {
6135 		if (val)
6136 			static_key_slow_inc(key);
6137 		else
6138 			static_key_slow_dec(key);
6139 		saved_val = val;
6140 	}
6141 	mutex_unlock(&bpf_stats_enabled_mutex);
6142 	return ret;
6143 }
6144 
unpriv_ebpf_notify(int new_state)6145 void __weak unpriv_ebpf_notify(int new_state)
6146 {
6147 }
6148 
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6149 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6150 			      void *buffer, size_t *lenp, loff_t *ppos)
6151 {
6152 	int ret, unpriv_enable = *(int *)table->data;
6153 	bool locked_state = unpriv_enable == 1;
6154 	struct ctl_table tmp = *table;
6155 
6156 	if (write && !capable(CAP_SYS_ADMIN))
6157 		return -EPERM;
6158 
6159 	tmp.data = &unpriv_enable;
6160 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6161 	if (write && !ret) {
6162 		if (locked_state && unpriv_enable != 1)
6163 			return -EPERM;
6164 		*(int *)table->data = unpriv_enable;
6165 	}
6166 
6167 	if (write)
6168 		unpriv_ebpf_notify(unpriv_enable);
6169 
6170 	return ret;
6171 }
6172 
6173 static const struct ctl_table bpf_syscall_table[] = {
6174 	{
6175 		.procname	= "unprivileged_bpf_disabled",
6176 		.data		= &sysctl_unprivileged_bpf_disabled,
6177 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
6178 		.mode		= 0644,
6179 		.proc_handler	= bpf_unpriv_handler,
6180 		.extra1		= SYSCTL_ZERO,
6181 		.extra2		= SYSCTL_TWO,
6182 	},
6183 	{
6184 		.procname	= "bpf_stats_enabled",
6185 		.data		= &bpf_stats_enabled_key.key,
6186 		.mode		= 0644,
6187 		.proc_handler	= bpf_stats_handler,
6188 	},
6189 };
6190 
bpf_syscall_sysctl_init(void)6191 static int __init bpf_syscall_sysctl_init(void)
6192 {
6193 	register_sysctl_init("kernel", bpf_syscall_table);
6194 	return 0;
6195 }
6196 late_initcall(bpf_syscall_sysctl_init);
6197 #endif /* CONFIG_SYSCTL */
6198