xref: /linux/kernel/bpf/syscall.c (revision 7203ca412fc8e8a0588e9adc0f777d3163f8dff3)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3  */
4 #include <crypto/sha2.h>
5 #include <linux/bpf.h>
6 #include <linux/bpf-cgroup.h>
7 #include <linux/bpf_trace.h>
8 #include <linux/bpf_lirc.h>
9 #include <linux/bpf_verifier.h>
10 #include <linux/bsearch.h>
11 #include <linux/btf.h>
12 #include <linux/syscalls.h>
13 #include <linux/slab.h>
14 #include <linux/sched/signal.h>
15 #include <linux/vmalloc.h>
16 #include <linux/mmzone.h>
17 #include <linux/anon_inodes.h>
18 #include <linux/fdtable.h>
19 #include <linux/file.h>
20 #include <linux/fs.h>
21 #include <linux/license.h>
22 #include <linux/filter.h>
23 #include <linux/kernel.h>
24 #include <linux/idr.h>
25 #include <linux/cred.h>
26 #include <linux/timekeeping.h>
27 #include <linux/ctype.h>
28 #include <linux/nospec.h>
29 #include <linux/audit.h>
30 #include <uapi/linux/btf.h>
31 #include <linux/pgtable.h>
32 #include <linux/bpf_lsm.h>
33 #include <linux/poll.h>
34 #include <linux/sort.h>
35 #include <linux/bpf-netns.h>
36 #include <linux/rcupdate_trace.h>
37 #include <linux/memcontrol.h>
38 #include <linux/trace_events.h>
39 #include <linux/tracepoint.h>
40 #include <linux/overflow.h>
41 #include <linux/cookie.h>
42 #include <linux/verification.h>
43 
44 #include <net/netfilter/nf_bpf_link.h>
45 #include <net/netkit.h>
46 #include <net/tcx.h>
47 
48 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
49 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
50 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
51 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
52 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
53 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
54 			IS_FD_HASH(map))
55 
56 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
57 
58 DEFINE_PER_CPU(int, bpf_prog_active);
59 DEFINE_COOKIE(bpf_map_cookie);
60 static DEFINE_IDR(prog_idr);
61 static DEFINE_SPINLOCK(prog_idr_lock);
62 static DEFINE_IDR(map_idr);
63 static DEFINE_SPINLOCK(map_idr_lock);
64 static DEFINE_IDR(link_idr);
65 static DEFINE_SPINLOCK(link_idr_lock);
66 
67 int sysctl_unprivileged_bpf_disabled __read_mostly =
68 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
69 
70 static const struct bpf_map_ops * const bpf_map_types[] = {
71 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
72 #define BPF_MAP_TYPE(_id, _ops) \
73 	[_id] = &_ops,
74 #define BPF_LINK_TYPE(_id, _name)
75 #include <linux/bpf_types.h>
76 #undef BPF_PROG_TYPE
77 #undef BPF_MAP_TYPE
78 #undef BPF_LINK_TYPE
79 };
80 
81 /*
82  * If we're handed a bigger struct than we know of, ensure all the unknown bits
83  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
84  * we don't know about yet.
85  *
86  * There is a ToCToU between this function call and the following
87  * copy_from_user() call. However, this is not a concern since this function is
88  * meant to be a future-proofing of bits.
89  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)90 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
91 			     size_t expected_size,
92 			     size_t actual_size)
93 {
94 	int res;
95 
96 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
97 		return -E2BIG;
98 
99 	if (actual_size <= expected_size)
100 		return 0;
101 
102 	if (uaddr.is_kernel)
103 		res = memchr_inv(uaddr.kernel + expected_size, 0,
104 				 actual_size - expected_size) == NULL;
105 	else
106 		res = check_zeroed_user(uaddr.user + expected_size,
107 					actual_size - expected_size);
108 	if (res < 0)
109 		return res;
110 	return res ? 0 : -E2BIG;
111 }
112 
113 const struct bpf_map_ops bpf_map_offload_ops = {
114 	.map_meta_equal = bpf_map_meta_equal,
115 	.map_alloc = bpf_map_offload_map_alloc,
116 	.map_free = bpf_map_offload_map_free,
117 	.map_check_btf = map_check_no_btf,
118 	.map_mem_usage = bpf_map_offload_map_mem_usage,
119 };
120 
bpf_map_write_active_inc(struct bpf_map * map)121 static void bpf_map_write_active_inc(struct bpf_map *map)
122 {
123 	atomic64_inc(&map->writecnt);
124 }
125 
bpf_map_write_active_dec(struct bpf_map * map)126 static void bpf_map_write_active_dec(struct bpf_map *map)
127 {
128 	atomic64_dec(&map->writecnt);
129 }
130 
bpf_map_write_active(const struct bpf_map * map)131 bool bpf_map_write_active(const struct bpf_map *map)
132 {
133 	return atomic64_read(&map->writecnt) != 0;
134 }
135 
bpf_map_value_size(const struct bpf_map * map)136 static u32 bpf_map_value_size(const struct bpf_map *map)
137 {
138 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
139 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
140 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
141 	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
142 		return round_up(map->value_size, 8) * num_possible_cpus();
143 	else if (IS_FD_MAP(map))
144 		return sizeof(u32);
145 	else
146 		return  map->value_size;
147 }
148 
maybe_wait_bpf_programs(struct bpf_map * map)149 static void maybe_wait_bpf_programs(struct bpf_map *map)
150 {
151 	/* Wait for any running non-sleepable BPF programs to complete so that
152 	 * userspace, when we return to it, knows that all non-sleepable
153 	 * programs that could be running use the new map value. For sleepable
154 	 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
155 	 * for the completions of these programs, but considering the waiting
156 	 * time can be very long and userspace may think it will hang forever,
157 	 * so don't handle sleepable BPF programs now.
158 	 */
159 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
160 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
161 		synchronize_rcu_expedited();
162 }
163 
unpin_uptr_kaddr(void * kaddr)164 static void unpin_uptr_kaddr(void *kaddr)
165 {
166 	if (kaddr)
167 		unpin_user_page(virt_to_page(kaddr));
168 }
169 
__bpf_obj_unpin_uptrs(struct btf_record * rec,u32 cnt,void * obj)170 static void __bpf_obj_unpin_uptrs(struct btf_record *rec, u32 cnt, void *obj)
171 {
172 	const struct btf_field *field;
173 	void **uptr_addr;
174 	int i;
175 
176 	for (i = 0, field = rec->fields; i < cnt; i++, field++) {
177 		if (field->type != BPF_UPTR)
178 			continue;
179 
180 		uptr_addr = obj + field->offset;
181 		unpin_uptr_kaddr(*uptr_addr);
182 	}
183 }
184 
bpf_obj_unpin_uptrs(struct btf_record * rec,void * obj)185 static void bpf_obj_unpin_uptrs(struct btf_record *rec, void *obj)
186 {
187 	if (!btf_record_has_field(rec, BPF_UPTR))
188 		return;
189 
190 	__bpf_obj_unpin_uptrs(rec, rec->cnt, obj);
191 }
192 
bpf_obj_pin_uptrs(struct btf_record * rec,void * obj)193 static int bpf_obj_pin_uptrs(struct btf_record *rec, void *obj)
194 {
195 	const struct btf_field *field;
196 	const struct btf_type *t;
197 	unsigned long start, end;
198 	struct page *page;
199 	void **uptr_addr;
200 	int i, err;
201 
202 	if (!btf_record_has_field(rec, BPF_UPTR))
203 		return 0;
204 
205 	for (i = 0, field = rec->fields; i < rec->cnt; i++, field++) {
206 		if (field->type != BPF_UPTR)
207 			continue;
208 
209 		uptr_addr = obj + field->offset;
210 		start = *(unsigned long *)uptr_addr;
211 		if (!start)
212 			continue;
213 
214 		t = btf_type_by_id(field->kptr.btf, field->kptr.btf_id);
215 		/* t->size was checked for zero before */
216 		if (check_add_overflow(start, t->size - 1, &end)) {
217 			err = -EFAULT;
218 			goto unpin_all;
219 		}
220 
221 		/* The uptr's struct cannot span across two pages */
222 		if ((start & PAGE_MASK) != (end & PAGE_MASK)) {
223 			err = -EOPNOTSUPP;
224 			goto unpin_all;
225 		}
226 
227 		err = pin_user_pages_fast(start, 1, FOLL_LONGTERM | FOLL_WRITE, &page);
228 		if (err != 1)
229 			goto unpin_all;
230 
231 		if (PageHighMem(page)) {
232 			err = -EOPNOTSUPP;
233 			unpin_user_page(page);
234 			goto unpin_all;
235 		}
236 
237 		*uptr_addr = page_address(page) + offset_in_page(start);
238 	}
239 
240 	return 0;
241 
242 unpin_all:
243 	__bpf_obj_unpin_uptrs(rec, i, obj);
244 	return err;
245 }
246 
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)247 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
248 				void *key, void *value, __u64 flags)
249 {
250 	int err;
251 
252 	/* Need to create a kthread, thus must support schedule */
253 	if (bpf_map_is_offloaded(map)) {
254 		return bpf_map_offload_update_elem(map, key, value, flags);
255 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
256 		   map->map_type == BPF_MAP_TYPE_ARENA ||
257 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
258 		return map->ops->map_update_elem(map, key, value, flags);
259 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
260 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
261 		return sock_map_update_elem_sys(map, key, value, flags);
262 	} else if (IS_FD_PROG_ARRAY(map)) {
263 		return bpf_fd_array_map_update_elem(map, map_file, key, value,
264 						    flags);
265 	}
266 
267 	bpf_disable_instrumentation();
268 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
269 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
270 		err = bpf_percpu_hash_update(map, key, value, flags);
271 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
272 		err = bpf_percpu_array_update(map, key, value, flags);
273 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
274 		err = bpf_percpu_cgroup_storage_update(map, key, value,
275 						       flags);
276 	} else if (IS_FD_ARRAY(map)) {
277 		err = bpf_fd_array_map_update_elem(map, map_file, key, value,
278 						   flags);
279 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
280 		err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
281 						  flags);
282 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
283 		/* rcu_read_lock() is not needed */
284 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
285 							 flags);
286 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
287 		   map->map_type == BPF_MAP_TYPE_STACK ||
288 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
289 		err = map->ops->map_push_elem(map, value, flags);
290 	} else {
291 		err = bpf_obj_pin_uptrs(map->record, value);
292 		if (!err) {
293 			rcu_read_lock();
294 			err = map->ops->map_update_elem(map, key, value, flags);
295 			rcu_read_unlock();
296 			if (err)
297 				bpf_obj_unpin_uptrs(map->record, value);
298 		}
299 	}
300 	bpf_enable_instrumentation();
301 
302 	return err;
303 }
304 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)305 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
306 			      __u64 flags)
307 {
308 	void *ptr;
309 	int err;
310 
311 	if (bpf_map_is_offloaded(map))
312 		return bpf_map_offload_lookup_elem(map, key, value);
313 
314 	bpf_disable_instrumentation();
315 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
316 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
317 		err = bpf_percpu_hash_copy(map, key, value);
318 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
319 		err = bpf_percpu_array_copy(map, key, value);
320 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
321 		err = bpf_percpu_cgroup_storage_copy(map, key, value);
322 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
323 		err = bpf_stackmap_extract(map, key, value, false);
324 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
325 		err = bpf_fd_array_map_lookup_elem(map, key, value);
326 	} else if (IS_FD_HASH(map)) {
327 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
328 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
329 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
330 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
331 		   map->map_type == BPF_MAP_TYPE_STACK ||
332 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
333 		err = map->ops->map_peek_elem(map, value);
334 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
335 		/* struct_ops map requires directly updating "value" */
336 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
337 	} else {
338 		rcu_read_lock();
339 		if (map->ops->map_lookup_elem_sys_only)
340 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
341 		else
342 			ptr = map->ops->map_lookup_elem(map, key);
343 		if (IS_ERR(ptr)) {
344 			err = PTR_ERR(ptr);
345 		} else if (!ptr) {
346 			err = -ENOENT;
347 		} else {
348 			err = 0;
349 			if (flags & BPF_F_LOCK)
350 				/* lock 'ptr' and copy everything but lock */
351 				copy_map_value_locked(map, value, ptr, true);
352 			else
353 				copy_map_value(map, value, ptr);
354 			/* mask lock and timer, since value wasn't zero inited */
355 			check_and_init_map_value(map, value);
356 		}
357 		rcu_read_unlock();
358 	}
359 
360 	bpf_enable_instrumentation();
361 
362 	return err;
363 }
364 
365 /* Please, do not use this function outside from the map creation path
366  * (e.g. in map update path) without taking care of setting the active
367  * memory cgroup (see at bpf_map_kmalloc_node() for example).
368  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)369 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
370 {
371 	/* We really just want to fail instead of triggering OOM killer
372 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
373 	 * which is used for lower order allocation requests.
374 	 *
375 	 * It has been observed that higher order allocation requests done by
376 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
377 	 * to reclaim memory from the page cache, thus we set
378 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
379 	 */
380 
381 	gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
382 	unsigned int flags = 0;
383 	unsigned long align = 1;
384 	void *area;
385 
386 	if (size >= SIZE_MAX)
387 		return NULL;
388 
389 	/* kmalloc()'ed memory can't be mmap()'ed */
390 	if (mmapable) {
391 		BUG_ON(!PAGE_ALIGNED(size));
392 		align = SHMLBA;
393 		flags = VM_USERMAP;
394 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
395 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
396 				    numa_node);
397 		if (area != NULL)
398 			return area;
399 	}
400 
401 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
402 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
403 			flags, numa_node, __builtin_return_address(0));
404 }
405 
bpf_map_area_alloc(u64 size,int numa_node)406 void *bpf_map_area_alloc(u64 size, int numa_node)
407 {
408 	return __bpf_map_area_alloc(size, numa_node, false);
409 }
410 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)411 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
412 {
413 	return __bpf_map_area_alloc(size, numa_node, true);
414 }
415 
bpf_map_area_free(void * area)416 void bpf_map_area_free(void *area)
417 {
418 	kvfree(area);
419 }
420 
bpf_map_flags_retain_permanent(u32 flags)421 static u32 bpf_map_flags_retain_permanent(u32 flags)
422 {
423 	/* Some map creation flags are not tied to the map object but
424 	 * rather to the map fd instead, so they have no meaning upon
425 	 * map object inspection since multiple file descriptors with
426 	 * different (access) properties can exist here. Thus, given
427 	 * this has zero meaning for the map itself, lets clear these
428 	 * from here.
429 	 */
430 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
431 }
432 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)433 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
434 {
435 	map->map_type = attr->map_type;
436 	map->key_size = attr->key_size;
437 	map->value_size = attr->value_size;
438 	map->max_entries = attr->max_entries;
439 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
440 	map->numa_node = bpf_map_attr_numa_node(attr);
441 	map->map_extra = attr->map_extra;
442 }
443 
bpf_map_alloc_id(struct bpf_map * map)444 static int bpf_map_alloc_id(struct bpf_map *map)
445 {
446 	int id;
447 
448 	idr_preload(GFP_KERNEL);
449 	spin_lock_bh(&map_idr_lock);
450 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
451 	if (id > 0)
452 		map->id = id;
453 	spin_unlock_bh(&map_idr_lock);
454 	idr_preload_end();
455 
456 	if (WARN_ON_ONCE(!id))
457 		return -ENOSPC;
458 
459 	return id > 0 ? 0 : id;
460 }
461 
bpf_map_free_id(struct bpf_map * map)462 void bpf_map_free_id(struct bpf_map *map)
463 {
464 	unsigned long flags;
465 
466 	/* Offloaded maps are removed from the IDR store when their device
467 	 * disappears - even if someone holds an fd to them they are unusable,
468 	 * the memory is gone, all ops will fail; they are simply waiting for
469 	 * refcnt to drop to be freed.
470 	 */
471 	if (!map->id)
472 		return;
473 
474 	spin_lock_irqsave(&map_idr_lock, flags);
475 
476 	idr_remove(&map_idr, map->id);
477 	map->id = 0;
478 
479 	spin_unlock_irqrestore(&map_idr_lock, flags);
480 }
481 
482 #ifdef CONFIG_MEMCG
bpf_map_save_memcg(struct bpf_map * map)483 static void bpf_map_save_memcg(struct bpf_map *map)
484 {
485 	/* Currently if a map is created by a process belonging to the root
486 	 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
487 	 * So we have to check map->objcg for being NULL each time it's
488 	 * being used.
489 	 */
490 	if (memcg_bpf_enabled())
491 		map->objcg = get_obj_cgroup_from_current();
492 }
493 
bpf_map_release_memcg(struct bpf_map * map)494 static void bpf_map_release_memcg(struct bpf_map *map)
495 {
496 	if (map->objcg)
497 		obj_cgroup_put(map->objcg);
498 }
499 
bpf_map_get_memcg(const struct bpf_map * map)500 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
501 {
502 	if (map->objcg)
503 		return get_mem_cgroup_from_objcg(map->objcg);
504 
505 	return root_mem_cgroup;
506 }
507 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)508 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
509 			   int node)
510 {
511 	struct mem_cgroup *memcg, *old_memcg;
512 	void *ptr;
513 
514 	memcg = bpf_map_get_memcg(map);
515 	old_memcg = set_active_memcg(memcg);
516 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
517 	set_active_memcg(old_memcg);
518 	mem_cgroup_put(memcg);
519 
520 	return ptr;
521 }
522 
bpf_map_kmalloc_nolock(const struct bpf_map * map,size_t size,gfp_t flags,int node)523 void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags,
524 			     int node)
525 {
526 	struct mem_cgroup *memcg, *old_memcg;
527 	void *ptr;
528 
529 	memcg = bpf_map_get_memcg(map);
530 	old_memcg = set_active_memcg(memcg);
531 	ptr = kmalloc_nolock(size, flags | __GFP_ACCOUNT, node);
532 	set_active_memcg(old_memcg);
533 	mem_cgroup_put(memcg);
534 
535 	return ptr;
536 }
537 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)538 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
539 {
540 	struct mem_cgroup *memcg, *old_memcg;
541 	void *ptr;
542 
543 	memcg = bpf_map_get_memcg(map);
544 	old_memcg = set_active_memcg(memcg);
545 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
546 	set_active_memcg(old_memcg);
547 	mem_cgroup_put(memcg);
548 
549 	return ptr;
550 }
551 
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)552 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
553 		       gfp_t flags)
554 {
555 	struct mem_cgroup *memcg, *old_memcg;
556 	void *ptr;
557 
558 	memcg = bpf_map_get_memcg(map);
559 	old_memcg = set_active_memcg(memcg);
560 	ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
561 	set_active_memcg(old_memcg);
562 	mem_cgroup_put(memcg);
563 
564 	return ptr;
565 }
566 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)567 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
568 				    size_t align, gfp_t flags)
569 {
570 	struct mem_cgroup *memcg, *old_memcg;
571 	void __percpu *ptr;
572 
573 	memcg = bpf_map_get_memcg(map);
574 	old_memcg = set_active_memcg(memcg);
575 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
576 	set_active_memcg(old_memcg);
577 	mem_cgroup_put(memcg);
578 
579 	return ptr;
580 }
581 
582 #else
bpf_map_save_memcg(struct bpf_map * map)583 static void bpf_map_save_memcg(struct bpf_map *map)
584 {
585 }
586 
bpf_map_release_memcg(struct bpf_map * map)587 static void bpf_map_release_memcg(struct bpf_map *map)
588 {
589 }
590 #endif
591 
can_alloc_pages(void)592 static bool can_alloc_pages(void)
593 {
594 	return preempt_count() == 0 && !irqs_disabled() &&
595 		!IS_ENABLED(CONFIG_PREEMPT_RT);
596 }
597 
__bpf_alloc_page(int nid)598 static struct page *__bpf_alloc_page(int nid)
599 {
600 	if (!can_alloc_pages())
601 		return alloc_pages_nolock(__GFP_ACCOUNT, nid, 0);
602 
603 	return alloc_pages_node(nid,
604 				GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT
605 				| __GFP_NOWARN,
606 				0);
607 }
608 
bpf_map_alloc_pages(const struct bpf_map * map,int nid,unsigned long nr_pages,struct page ** pages)609 int bpf_map_alloc_pages(const struct bpf_map *map, int nid,
610 			unsigned long nr_pages, struct page **pages)
611 {
612 	unsigned long i, j;
613 	struct page *pg;
614 	int ret = 0;
615 #ifdef CONFIG_MEMCG
616 	struct mem_cgroup *memcg, *old_memcg;
617 
618 	memcg = bpf_map_get_memcg(map);
619 	old_memcg = set_active_memcg(memcg);
620 #endif
621 	for (i = 0; i < nr_pages; i++) {
622 		pg = __bpf_alloc_page(nid);
623 
624 		if (pg) {
625 			pages[i] = pg;
626 			continue;
627 		}
628 		for (j = 0; j < i; j++)
629 			free_pages_nolock(pages[j], 0);
630 		ret = -ENOMEM;
631 		break;
632 	}
633 
634 #ifdef CONFIG_MEMCG
635 	set_active_memcg(old_memcg);
636 	mem_cgroup_put(memcg);
637 #endif
638 	return ret;
639 }
640 
641 
btf_field_cmp(const void * a,const void * b)642 static int btf_field_cmp(const void *a, const void *b)
643 {
644 	const struct btf_field *f1 = a, *f2 = b;
645 
646 	if (f1->offset < f2->offset)
647 		return -1;
648 	else if (f1->offset > f2->offset)
649 		return 1;
650 	return 0;
651 }
652 
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)653 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
654 				  u32 field_mask)
655 {
656 	struct btf_field *field;
657 
658 	if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
659 		return NULL;
660 	field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
661 	if (!field || !(field->type & field_mask))
662 		return NULL;
663 	return field;
664 }
665 
btf_record_free(struct btf_record * rec)666 void btf_record_free(struct btf_record *rec)
667 {
668 	int i;
669 
670 	if (IS_ERR_OR_NULL(rec))
671 		return;
672 	for (i = 0; i < rec->cnt; i++) {
673 		switch (rec->fields[i].type) {
674 		case BPF_KPTR_UNREF:
675 		case BPF_KPTR_REF:
676 		case BPF_KPTR_PERCPU:
677 		case BPF_UPTR:
678 			if (rec->fields[i].kptr.module)
679 				module_put(rec->fields[i].kptr.module);
680 			if (btf_is_kernel(rec->fields[i].kptr.btf))
681 				btf_put(rec->fields[i].kptr.btf);
682 			break;
683 		case BPF_LIST_HEAD:
684 		case BPF_LIST_NODE:
685 		case BPF_RB_ROOT:
686 		case BPF_RB_NODE:
687 		case BPF_SPIN_LOCK:
688 		case BPF_RES_SPIN_LOCK:
689 		case BPF_TIMER:
690 		case BPF_REFCOUNT:
691 		case BPF_WORKQUEUE:
692 		case BPF_TASK_WORK:
693 			/* Nothing to release */
694 			break;
695 		default:
696 			WARN_ON_ONCE(1);
697 			continue;
698 		}
699 	}
700 	kfree(rec);
701 }
702 
bpf_map_free_record(struct bpf_map * map)703 void bpf_map_free_record(struct bpf_map *map)
704 {
705 	btf_record_free(map->record);
706 	map->record = NULL;
707 }
708 
btf_record_dup(const struct btf_record * rec)709 struct btf_record *btf_record_dup(const struct btf_record *rec)
710 {
711 	const struct btf_field *fields;
712 	struct btf_record *new_rec;
713 	int ret, size, i;
714 
715 	if (IS_ERR_OR_NULL(rec))
716 		return NULL;
717 	size = struct_size(rec, fields, rec->cnt);
718 	new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
719 	if (!new_rec)
720 		return ERR_PTR(-ENOMEM);
721 	/* Do a deep copy of the btf_record */
722 	fields = rec->fields;
723 	new_rec->cnt = 0;
724 	for (i = 0; i < rec->cnt; i++) {
725 		switch (fields[i].type) {
726 		case BPF_KPTR_UNREF:
727 		case BPF_KPTR_REF:
728 		case BPF_KPTR_PERCPU:
729 		case BPF_UPTR:
730 			if (btf_is_kernel(fields[i].kptr.btf))
731 				btf_get(fields[i].kptr.btf);
732 			if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
733 				ret = -ENXIO;
734 				goto free;
735 			}
736 			break;
737 		case BPF_LIST_HEAD:
738 		case BPF_LIST_NODE:
739 		case BPF_RB_ROOT:
740 		case BPF_RB_NODE:
741 		case BPF_SPIN_LOCK:
742 		case BPF_RES_SPIN_LOCK:
743 		case BPF_TIMER:
744 		case BPF_REFCOUNT:
745 		case BPF_WORKQUEUE:
746 		case BPF_TASK_WORK:
747 			/* Nothing to acquire */
748 			break;
749 		default:
750 			ret = -EFAULT;
751 			WARN_ON_ONCE(1);
752 			goto free;
753 		}
754 		new_rec->cnt++;
755 	}
756 	return new_rec;
757 free:
758 	btf_record_free(new_rec);
759 	return ERR_PTR(ret);
760 }
761 
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)762 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
763 {
764 	bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
765 	int size;
766 
767 	if (!a_has_fields && !b_has_fields)
768 		return true;
769 	if (a_has_fields != b_has_fields)
770 		return false;
771 	if (rec_a->cnt != rec_b->cnt)
772 		return false;
773 	size = struct_size(rec_a, fields, rec_a->cnt);
774 	/* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
775 	 * members are zeroed out. So memcmp is safe to do without worrying
776 	 * about padding/unused fields.
777 	 *
778 	 * While spin_lock, timer, and kptr have no relation to map BTF,
779 	 * list_head metadata is specific to map BTF, the btf and value_rec
780 	 * members in particular. btf is the map BTF, while value_rec points to
781 	 * btf_record in that map BTF.
782 	 *
783 	 * So while by default, we don't rely on the map BTF (which the records
784 	 * were parsed from) matching for both records, which is not backwards
785 	 * compatible, in case list_head is part of it, we implicitly rely on
786 	 * that by way of depending on memcmp succeeding for it.
787 	 */
788 	return !memcmp(rec_a, rec_b, size);
789 }
790 
bpf_obj_free_timer(const struct btf_record * rec,void * obj)791 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
792 {
793 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
794 		return;
795 	bpf_timer_cancel_and_free(obj + rec->timer_off);
796 }
797 
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)798 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
799 {
800 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
801 		return;
802 	bpf_wq_cancel_and_free(obj + rec->wq_off);
803 }
804 
bpf_obj_free_task_work(const struct btf_record * rec,void * obj)805 void bpf_obj_free_task_work(const struct btf_record *rec, void *obj)
806 {
807 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TASK_WORK)))
808 		return;
809 	bpf_task_work_cancel_and_free(obj + rec->task_work_off);
810 }
811 
bpf_obj_free_fields(const struct btf_record * rec,void * obj)812 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
813 {
814 	const struct btf_field *fields;
815 	int i;
816 
817 	if (IS_ERR_OR_NULL(rec))
818 		return;
819 	fields = rec->fields;
820 	for (i = 0; i < rec->cnt; i++) {
821 		struct btf_struct_meta *pointee_struct_meta;
822 		const struct btf_field *field = &fields[i];
823 		void *field_ptr = obj + field->offset;
824 		void *xchgd_field;
825 
826 		switch (fields[i].type) {
827 		case BPF_SPIN_LOCK:
828 		case BPF_RES_SPIN_LOCK:
829 			break;
830 		case BPF_TIMER:
831 			bpf_timer_cancel_and_free(field_ptr);
832 			break;
833 		case BPF_WORKQUEUE:
834 			bpf_wq_cancel_and_free(field_ptr);
835 			break;
836 		case BPF_TASK_WORK:
837 			bpf_task_work_cancel_and_free(field_ptr);
838 			break;
839 		case BPF_KPTR_UNREF:
840 			WRITE_ONCE(*(u64 *)field_ptr, 0);
841 			break;
842 		case BPF_KPTR_REF:
843 		case BPF_KPTR_PERCPU:
844 			xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
845 			if (!xchgd_field)
846 				break;
847 
848 			if (!btf_is_kernel(field->kptr.btf)) {
849 				pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
850 									   field->kptr.btf_id);
851 				__bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
852 								 pointee_struct_meta->record : NULL,
853 								 fields[i].type == BPF_KPTR_PERCPU);
854 			} else {
855 				field->kptr.dtor(xchgd_field);
856 			}
857 			break;
858 		case BPF_UPTR:
859 			/* The caller ensured that no one is using the uptr */
860 			unpin_uptr_kaddr(*(void **)field_ptr);
861 			break;
862 		case BPF_LIST_HEAD:
863 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
864 				continue;
865 			bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
866 			break;
867 		case BPF_RB_ROOT:
868 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
869 				continue;
870 			bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
871 			break;
872 		case BPF_LIST_NODE:
873 		case BPF_RB_NODE:
874 		case BPF_REFCOUNT:
875 			break;
876 		default:
877 			WARN_ON_ONCE(1);
878 			continue;
879 		}
880 	}
881 }
882 
bpf_map_free(struct bpf_map * map)883 static void bpf_map_free(struct bpf_map *map)
884 {
885 	struct btf_record *rec = map->record;
886 	struct btf *btf = map->btf;
887 
888 	/* implementation dependent freeing. Disabling migration to simplify
889 	 * the free of values or special fields allocated from bpf memory
890 	 * allocator.
891 	 */
892 	kfree(map->excl_prog_sha);
893 	migrate_disable();
894 	map->ops->map_free(map);
895 	migrate_enable();
896 
897 	/* Delay freeing of btf_record for maps, as map_free
898 	 * callback usually needs access to them. It is better to do it here
899 	 * than require each callback to do the free itself manually.
900 	 *
901 	 * Note that the btf_record stashed in map->inner_map_meta->record was
902 	 * already freed using the map_free callback for map in map case which
903 	 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
904 	 * template bpf_map struct used during verification.
905 	 */
906 	btf_record_free(rec);
907 	/* Delay freeing of btf for maps, as map_free callback may need
908 	 * struct_meta info which will be freed with btf_put().
909 	 */
910 	btf_put(btf);
911 }
912 
913 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)914 static void bpf_map_free_deferred(struct work_struct *work)
915 {
916 	struct bpf_map *map = container_of(work, struct bpf_map, work);
917 
918 	security_bpf_map_free(map);
919 	bpf_map_release_memcg(map);
920 	bpf_map_owner_free(map);
921 	bpf_map_free(map);
922 }
923 
bpf_map_put_uref(struct bpf_map * map)924 static void bpf_map_put_uref(struct bpf_map *map)
925 {
926 	if (atomic64_dec_and_test(&map->usercnt)) {
927 		if (map->ops->map_release_uref)
928 			map->ops->map_release_uref(map);
929 	}
930 }
931 
bpf_map_free_in_work(struct bpf_map * map)932 static void bpf_map_free_in_work(struct bpf_map *map)
933 {
934 	INIT_WORK(&map->work, bpf_map_free_deferred);
935 	/* Avoid spawning kworkers, since they all might contend
936 	 * for the same mutex like slab_mutex.
937 	 */
938 	queue_work(system_dfl_wq, &map->work);
939 }
940 
bpf_map_free_rcu_gp(struct rcu_head * rcu)941 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
942 {
943 	bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
944 }
945 
bpf_map_free_mult_rcu_gp(struct rcu_head * rcu)946 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
947 {
948 	if (rcu_trace_implies_rcu_gp())
949 		bpf_map_free_rcu_gp(rcu);
950 	else
951 		call_rcu(rcu, bpf_map_free_rcu_gp);
952 }
953 
954 /* decrement map refcnt and schedule it for freeing via workqueue
955  * (underlying map implementation ops->map_free() might sleep)
956  */
bpf_map_put(struct bpf_map * map)957 void bpf_map_put(struct bpf_map *map)
958 {
959 	if (atomic64_dec_and_test(&map->refcnt)) {
960 		/* bpf_map_free_id() must be called first */
961 		bpf_map_free_id(map);
962 
963 		WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
964 		if (READ_ONCE(map->free_after_mult_rcu_gp))
965 			call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
966 		else if (READ_ONCE(map->free_after_rcu_gp))
967 			call_rcu(&map->rcu, bpf_map_free_rcu_gp);
968 		else
969 			bpf_map_free_in_work(map);
970 	}
971 }
972 EXPORT_SYMBOL_GPL(bpf_map_put);
973 
bpf_map_put_with_uref(struct bpf_map * map)974 void bpf_map_put_with_uref(struct bpf_map *map)
975 {
976 	bpf_map_put_uref(map);
977 	bpf_map_put(map);
978 }
979 
bpf_map_release(struct inode * inode,struct file * filp)980 static int bpf_map_release(struct inode *inode, struct file *filp)
981 {
982 	struct bpf_map *map = filp->private_data;
983 
984 	if (map->ops->map_release)
985 		map->ops->map_release(map, filp);
986 
987 	bpf_map_put_with_uref(map);
988 	return 0;
989 }
990 
map_get_sys_perms(struct bpf_map * map,struct fd f)991 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
992 {
993 	fmode_t mode = fd_file(f)->f_mode;
994 
995 	/* Our file permissions may have been overridden by global
996 	 * map permissions facing syscall side.
997 	 */
998 	if (READ_ONCE(map->frozen))
999 		mode &= ~FMODE_CAN_WRITE;
1000 	return mode;
1001 }
1002 
1003 #ifdef CONFIG_PROC_FS
1004 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)1005 static u64 bpf_map_memory_usage(const struct bpf_map *map)
1006 {
1007 	return map->ops->map_mem_usage(map);
1008 }
1009 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)1010 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
1011 {
1012 	struct bpf_map *map = filp->private_data;
1013 	u32 type = 0, jited = 0;
1014 
1015 	spin_lock(&map->owner_lock);
1016 	if (map->owner) {
1017 		type  = map->owner->type;
1018 		jited = map->owner->jited;
1019 	}
1020 	spin_unlock(&map->owner_lock);
1021 
1022 	seq_printf(m,
1023 		   "map_type:\t%u\n"
1024 		   "key_size:\t%u\n"
1025 		   "value_size:\t%u\n"
1026 		   "max_entries:\t%u\n"
1027 		   "map_flags:\t%#x\n"
1028 		   "map_extra:\t%#llx\n"
1029 		   "memlock:\t%llu\n"
1030 		   "map_id:\t%u\n"
1031 		   "frozen:\t%u\n",
1032 		   map->map_type,
1033 		   map->key_size,
1034 		   map->value_size,
1035 		   map->max_entries,
1036 		   map->map_flags,
1037 		   (unsigned long long)map->map_extra,
1038 		   bpf_map_memory_usage(map),
1039 		   map->id,
1040 		   READ_ONCE(map->frozen));
1041 	if (type) {
1042 		seq_printf(m, "owner_prog_type:\t%u\n", type);
1043 		seq_printf(m, "owner_jited:\t%u\n", jited);
1044 	}
1045 }
1046 #endif
1047 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)1048 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
1049 			      loff_t *ppos)
1050 {
1051 	/* We need this handler such that alloc_file() enables
1052 	 * f_mode with FMODE_CAN_READ.
1053 	 */
1054 	return -EINVAL;
1055 }
1056 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)1057 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
1058 			       size_t siz, loff_t *ppos)
1059 {
1060 	/* We need this handler such that alloc_file() enables
1061 	 * f_mode with FMODE_CAN_WRITE.
1062 	 */
1063 	return -EINVAL;
1064 }
1065 
1066 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)1067 static void bpf_map_mmap_open(struct vm_area_struct *vma)
1068 {
1069 	struct bpf_map *map = vma->vm_file->private_data;
1070 
1071 	if (vma->vm_flags & VM_MAYWRITE)
1072 		bpf_map_write_active_inc(map);
1073 }
1074 
1075 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)1076 static void bpf_map_mmap_close(struct vm_area_struct *vma)
1077 {
1078 	struct bpf_map *map = vma->vm_file->private_data;
1079 
1080 	if (vma->vm_flags & VM_MAYWRITE)
1081 		bpf_map_write_active_dec(map);
1082 }
1083 
1084 static const struct vm_operations_struct bpf_map_default_vmops = {
1085 	.open		= bpf_map_mmap_open,
1086 	.close		= bpf_map_mmap_close,
1087 };
1088 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)1089 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
1090 {
1091 	struct bpf_map *map = filp->private_data;
1092 	int err = 0;
1093 
1094 	if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
1095 		return -ENOTSUPP;
1096 
1097 	if (!(vma->vm_flags & VM_SHARED))
1098 		return -EINVAL;
1099 
1100 	mutex_lock(&map->freeze_mutex);
1101 
1102 	if (vma->vm_flags & VM_WRITE) {
1103 		if (map->frozen) {
1104 			err = -EPERM;
1105 			goto out;
1106 		}
1107 		/* map is meant to be read-only, so do not allow mapping as
1108 		 * writable, because it's possible to leak a writable page
1109 		 * reference and allows user-space to still modify it after
1110 		 * freezing, while verifier will assume contents do not change
1111 		 */
1112 		if (map->map_flags & BPF_F_RDONLY_PROG) {
1113 			err = -EACCES;
1114 			goto out;
1115 		}
1116 		bpf_map_write_active_inc(map);
1117 	}
1118 out:
1119 	mutex_unlock(&map->freeze_mutex);
1120 	if (err)
1121 		return err;
1122 
1123 	/* set default open/close callbacks */
1124 	vma->vm_ops = &bpf_map_default_vmops;
1125 	vma->vm_private_data = map;
1126 	vm_flags_clear(vma, VM_MAYEXEC);
1127 	/* If mapping is read-only, then disallow potentially re-mapping with
1128 	 * PROT_WRITE by dropping VM_MAYWRITE flag. This VM_MAYWRITE clearing
1129 	 * means that as far as BPF map's memory-mapped VMAs are concerned,
1130 	 * VM_WRITE and VM_MAYWRITE and equivalent, if one of them is set,
1131 	 * both should be set, so we can forget about VM_MAYWRITE and always
1132 	 * check just VM_WRITE
1133 	 */
1134 	if (!(vma->vm_flags & VM_WRITE))
1135 		vm_flags_clear(vma, VM_MAYWRITE);
1136 
1137 	err = map->ops->map_mmap(map, vma);
1138 	if (err) {
1139 		if (vma->vm_flags & VM_WRITE)
1140 			bpf_map_write_active_dec(map);
1141 	}
1142 
1143 	return err;
1144 }
1145 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)1146 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
1147 {
1148 	struct bpf_map *map = filp->private_data;
1149 
1150 	if (map->ops->map_poll)
1151 		return map->ops->map_poll(map, filp, pts);
1152 
1153 	return EPOLLERR;
1154 }
1155 
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)1156 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
1157 					   unsigned long len, unsigned long pgoff,
1158 					   unsigned long flags)
1159 {
1160 	struct bpf_map *map = filp->private_data;
1161 
1162 	if (map->ops->map_get_unmapped_area)
1163 		return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
1164 #ifdef CONFIG_MMU
1165 	return mm_get_unmapped_area(filp, addr, len, pgoff, flags);
1166 #else
1167 	return addr;
1168 #endif
1169 }
1170 
1171 const struct file_operations bpf_map_fops = {
1172 #ifdef CONFIG_PROC_FS
1173 	.show_fdinfo	= bpf_map_show_fdinfo,
1174 #endif
1175 	.release	= bpf_map_release,
1176 	.read		= bpf_dummy_read,
1177 	.write		= bpf_dummy_write,
1178 	.mmap		= bpf_map_mmap,
1179 	.poll		= bpf_map_poll,
1180 	.get_unmapped_area = bpf_get_unmapped_area,
1181 };
1182 
bpf_map_new_fd(struct bpf_map * map,int flags)1183 int bpf_map_new_fd(struct bpf_map *map, int flags)
1184 {
1185 	int ret;
1186 
1187 	ret = security_bpf_map(map, OPEN_FMODE(flags));
1188 	if (ret < 0)
1189 		return ret;
1190 
1191 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1192 				flags | O_CLOEXEC);
1193 }
1194 
bpf_get_file_flag(int flags)1195 int bpf_get_file_flag(int flags)
1196 {
1197 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1198 		return -EINVAL;
1199 	if (flags & BPF_F_RDONLY)
1200 		return O_RDONLY;
1201 	if (flags & BPF_F_WRONLY)
1202 		return O_WRONLY;
1203 	return O_RDWR;
1204 }
1205 
1206 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1207 #define CHECK_ATTR(CMD) \
1208 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1209 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
1210 		   sizeof(*attr) - \
1211 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1212 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
1213 
1214 /* dst and src must have at least "size" number of bytes.
1215  * Return strlen on success and < 0 on error.
1216  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1217 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1218 {
1219 	const char *end = src + size;
1220 	const char *orig_src = src;
1221 
1222 	memset(dst, 0, size);
1223 	/* Copy all isalnum(), '_' and '.' chars. */
1224 	while (src < end && *src) {
1225 		if (!isalnum(*src) &&
1226 		    *src != '_' && *src != '.')
1227 			return -EINVAL;
1228 		*dst++ = *src++;
1229 	}
1230 
1231 	/* No '\0' found in "size" number of bytes */
1232 	if (src == end)
1233 		return -EINVAL;
1234 
1235 	return src - orig_src;
1236 }
1237 EXPORT_SYMBOL_GPL(bpf_obj_name_cpy);
1238 
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)1239 int map_check_no_btf(const struct bpf_map *map,
1240 		     const struct btf *btf,
1241 		     const struct btf_type *key_type,
1242 		     const struct btf_type *value_type)
1243 {
1244 	return -ENOTSUPP;
1245 }
1246 
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1247 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1248 			 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1249 {
1250 	const struct btf_type *key_type, *value_type;
1251 	u32 key_size, value_size;
1252 	int ret = 0;
1253 
1254 	/* Some maps allow key to be unspecified. */
1255 	if (btf_key_id) {
1256 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1257 		if (!key_type || key_size != map->key_size)
1258 			return -EINVAL;
1259 	} else {
1260 		key_type = btf_type_by_id(btf, 0);
1261 		if (!map->ops->map_check_btf)
1262 			return -EINVAL;
1263 	}
1264 
1265 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1266 	if (!value_type || value_size != map->value_size)
1267 		return -EINVAL;
1268 
1269 	map->record = btf_parse_fields(btf, value_type,
1270 				       BPF_SPIN_LOCK | BPF_RES_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1271 				       BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE | BPF_UPTR |
1272 				       BPF_TASK_WORK,
1273 				       map->value_size);
1274 	if (!IS_ERR_OR_NULL(map->record)) {
1275 		int i;
1276 
1277 		if (!bpf_token_capable(token, CAP_BPF)) {
1278 			ret = -EPERM;
1279 			goto free_map_tab;
1280 		}
1281 		if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1282 			ret = -EACCES;
1283 			goto free_map_tab;
1284 		}
1285 		for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1286 			switch (map->record->field_mask & (1 << i)) {
1287 			case 0:
1288 				continue;
1289 			case BPF_SPIN_LOCK:
1290 			case BPF_RES_SPIN_LOCK:
1291 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1292 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1293 				    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1294 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1295 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1296 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1297 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1298 					ret = -EOPNOTSUPP;
1299 					goto free_map_tab;
1300 				}
1301 				break;
1302 			case BPF_TIMER:
1303 			case BPF_WORKQUEUE:
1304 			case BPF_TASK_WORK:
1305 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1306 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1307 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1308 					ret = -EOPNOTSUPP;
1309 					goto free_map_tab;
1310 				}
1311 				break;
1312 			case BPF_KPTR_UNREF:
1313 			case BPF_KPTR_REF:
1314 			case BPF_KPTR_PERCPU:
1315 			case BPF_REFCOUNT:
1316 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1317 				    map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1318 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1319 				    map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1320 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1321 				    map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1322 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1323 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1324 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1325 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1326 					ret = -EOPNOTSUPP;
1327 					goto free_map_tab;
1328 				}
1329 				break;
1330 			case BPF_UPTR:
1331 				if (map->map_type != BPF_MAP_TYPE_TASK_STORAGE) {
1332 					ret = -EOPNOTSUPP;
1333 					goto free_map_tab;
1334 				}
1335 				break;
1336 			case BPF_LIST_HEAD:
1337 			case BPF_RB_ROOT:
1338 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1339 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1340 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1341 					ret = -EOPNOTSUPP;
1342 					goto free_map_tab;
1343 				}
1344 				break;
1345 			default:
1346 				/* Fail if map_type checks are missing for a field type */
1347 				ret = -EOPNOTSUPP;
1348 				goto free_map_tab;
1349 			}
1350 		}
1351 	}
1352 
1353 	ret = btf_check_and_fixup_fields(btf, map->record);
1354 	if (ret < 0)
1355 		goto free_map_tab;
1356 
1357 	if (map->ops->map_check_btf) {
1358 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1359 		if (ret < 0)
1360 			goto free_map_tab;
1361 	}
1362 
1363 	return ret;
1364 free_map_tab:
1365 	bpf_map_free_record(map);
1366 	return ret;
1367 }
1368 
bpf_net_capable(void)1369 static bool bpf_net_capable(void)
1370 {
1371 	return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
1372 }
1373 
1374 #define BPF_MAP_CREATE_LAST_FIELD excl_prog_hash_size
1375 /* called via syscall */
map_create(union bpf_attr * attr,bpfptr_t uattr)1376 static int map_create(union bpf_attr *attr, bpfptr_t uattr)
1377 {
1378 	const struct bpf_map_ops *ops;
1379 	struct bpf_token *token = NULL;
1380 	int numa_node = bpf_map_attr_numa_node(attr);
1381 	u32 map_type = attr->map_type;
1382 	struct bpf_map *map;
1383 	bool token_flag;
1384 	int f_flags;
1385 	int err;
1386 
1387 	err = CHECK_ATTR(BPF_MAP_CREATE);
1388 	if (err)
1389 		return -EINVAL;
1390 
1391 	/* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1392 	 * to avoid per-map type checks tripping on unknown flag
1393 	 */
1394 	token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1395 	attr->map_flags &= ~BPF_F_TOKEN_FD;
1396 
1397 	if (attr->btf_vmlinux_value_type_id) {
1398 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1399 		    attr->btf_key_type_id || attr->btf_value_type_id)
1400 			return -EINVAL;
1401 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1402 		return -EINVAL;
1403 	}
1404 
1405 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1406 	    attr->map_type != BPF_MAP_TYPE_ARENA &&
1407 	    attr->map_extra != 0)
1408 		return -EINVAL;
1409 
1410 	f_flags = bpf_get_file_flag(attr->map_flags);
1411 	if (f_flags < 0)
1412 		return f_flags;
1413 
1414 	if (numa_node != NUMA_NO_NODE &&
1415 	    ((unsigned int)numa_node >= nr_node_ids ||
1416 	     !node_online(numa_node)))
1417 		return -EINVAL;
1418 
1419 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1420 	map_type = attr->map_type;
1421 	if (map_type >= ARRAY_SIZE(bpf_map_types))
1422 		return -EINVAL;
1423 	map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1424 	ops = bpf_map_types[map_type];
1425 	if (!ops)
1426 		return -EINVAL;
1427 
1428 	if (ops->map_alloc_check) {
1429 		err = ops->map_alloc_check(attr);
1430 		if (err)
1431 			return err;
1432 	}
1433 	if (attr->map_ifindex)
1434 		ops = &bpf_map_offload_ops;
1435 	if (!ops->map_mem_usage)
1436 		return -EINVAL;
1437 
1438 	if (token_flag) {
1439 		token = bpf_token_get_from_fd(attr->map_token_fd);
1440 		if (IS_ERR(token))
1441 			return PTR_ERR(token);
1442 
1443 		/* if current token doesn't grant map creation permissions,
1444 		 * then we can't use this token, so ignore it and rely on
1445 		 * system-wide capabilities checks
1446 		 */
1447 		if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1448 		    !bpf_token_allow_map_type(token, attr->map_type)) {
1449 			bpf_token_put(token);
1450 			token = NULL;
1451 		}
1452 	}
1453 
1454 	err = -EPERM;
1455 
1456 	/* Intent here is for unprivileged_bpf_disabled to block BPF map
1457 	 * creation for unprivileged users; other actions depend
1458 	 * on fd availability and access to bpffs, so are dependent on
1459 	 * object creation success. Even with unprivileged BPF disabled,
1460 	 * capability checks are still carried out.
1461 	 */
1462 	if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1463 		goto put_token;
1464 
1465 	/* check privileged map type permissions */
1466 	switch (map_type) {
1467 	case BPF_MAP_TYPE_ARRAY:
1468 	case BPF_MAP_TYPE_PERCPU_ARRAY:
1469 	case BPF_MAP_TYPE_PROG_ARRAY:
1470 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1471 	case BPF_MAP_TYPE_CGROUP_ARRAY:
1472 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1473 	case BPF_MAP_TYPE_HASH:
1474 	case BPF_MAP_TYPE_PERCPU_HASH:
1475 	case BPF_MAP_TYPE_HASH_OF_MAPS:
1476 	case BPF_MAP_TYPE_RINGBUF:
1477 	case BPF_MAP_TYPE_USER_RINGBUF:
1478 	case BPF_MAP_TYPE_CGROUP_STORAGE:
1479 	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1480 		/* unprivileged */
1481 		break;
1482 	case BPF_MAP_TYPE_SK_STORAGE:
1483 	case BPF_MAP_TYPE_INODE_STORAGE:
1484 	case BPF_MAP_TYPE_TASK_STORAGE:
1485 	case BPF_MAP_TYPE_CGRP_STORAGE:
1486 	case BPF_MAP_TYPE_BLOOM_FILTER:
1487 	case BPF_MAP_TYPE_LPM_TRIE:
1488 	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1489 	case BPF_MAP_TYPE_STACK_TRACE:
1490 	case BPF_MAP_TYPE_QUEUE:
1491 	case BPF_MAP_TYPE_STACK:
1492 	case BPF_MAP_TYPE_LRU_HASH:
1493 	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1494 	case BPF_MAP_TYPE_STRUCT_OPS:
1495 	case BPF_MAP_TYPE_CPUMAP:
1496 	case BPF_MAP_TYPE_ARENA:
1497 	case BPF_MAP_TYPE_INSN_ARRAY:
1498 		if (!bpf_token_capable(token, CAP_BPF))
1499 			goto put_token;
1500 		break;
1501 	case BPF_MAP_TYPE_SOCKMAP:
1502 	case BPF_MAP_TYPE_SOCKHASH:
1503 	case BPF_MAP_TYPE_DEVMAP:
1504 	case BPF_MAP_TYPE_DEVMAP_HASH:
1505 	case BPF_MAP_TYPE_XSKMAP:
1506 		if (!bpf_token_capable(token, CAP_NET_ADMIN))
1507 			goto put_token;
1508 		break;
1509 	default:
1510 		WARN(1, "unsupported map type %d", map_type);
1511 		goto put_token;
1512 	}
1513 
1514 	map = ops->map_alloc(attr);
1515 	if (IS_ERR(map)) {
1516 		err = PTR_ERR(map);
1517 		goto put_token;
1518 	}
1519 	map->ops = ops;
1520 	map->map_type = map_type;
1521 
1522 	err = bpf_obj_name_cpy(map->name, attr->map_name,
1523 			       sizeof(attr->map_name));
1524 	if (err < 0)
1525 		goto free_map;
1526 
1527 	preempt_disable();
1528 	map->cookie = gen_cookie_next(&bpf_map_cookie);
1529 	preempt_enable();
1530 
1531 	atomic64_set(&map->refcnt, 1);
1532 	atomic64_set(&map->usercnt, 1);
1533 	mutex_init(&map->freeze_mutex);
1534 	spin_lock_init(&map->owner_lock);
1535 
1536 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
1537 	    /* Even the map's value is a kernel's struct,
1538 	     * the bpf_prog.o must have BTF to begin with
1539 	     * to figure out the corresponding kernel's
1540 	     * counter part.  Thus, attr->btf_fd has
1541 	     * to be valid also.
1542 	     */
1543 	    attr->btf_vmlinux_value_type_id) {
1544 		struct btf *btf;
1545 
1546 		btf = btf_get_by_fd(attr->btf_fd);
1547 		if (IS_ERR(btf)) {
1548 			err = PTR_ERR(btf);
1549 			goto free_map;
1550 		}
1551 		if (btf_is_kernel(btf)) {
1552 			btf_put(btf);
1553 			err = -EACCES;
1554 			goto free_map;
1555 		}
1556 		map->btf = btf;
1557 
1558 		if (attr->btf_value_type_id) {
1559 			err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1560 					    attr->btf_value_type_id);
1561 			if (err)
1562 				goto free_map;
1563 		}
1564 
1565 		map->btf_key_type_id = attr->btf_key_type_id;
1566 		map->btf_value_type_id = attr->btf_value_type_id;
1567 		map->btf_vmlinux_value_type_id =
1568 			attr->btf_vmlinux_value_type_id;
1569 	}
1570 
1571 	if (attr->excl_prog_hash) {
1572 		bpfptr_t uprog_hash = make_bpfptr(attr->excl_prog_hash, uattr.is_kernel);
1573 
1574 		if (attr->excl_prog_hash_size != SHA256_DIGEST_SIZE) {
1575 			err = -EINVAL;
1576 			goto free_map;
1577 		}
1578 
1579 		map->excl_prog_sha = kzalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
1580 		if (!map->excl_prog_sha) {
1581 			err = -ENOMEM;
1582 			goto free_map;
1583 		}
1584 
1585 		if (copy_from_bpfptr(map->excl_prog_sha, uprog_hash, SHA256_DIGEST_SIZE)) {
1586 			err = -EFAULT;
1587 			goto free_map;
1588 		}
1589 	} else if (attr->excl_prog_hash_size) {
1590 		err = -EINVAL;
1591 		goto free_map;
1592 	}
1593 
1594 	err = security_bpf_map_create(map, attr, token, uattr.is_kernel);
1595 	if (err)
1596 		goto free_map_sec;
1597 
1598 	err = bpf_map_alloc_id(map);
1599 	if (err)
1600 		goto free_map_sec;
1601 
1602 	bpf_map_save_memcg(map);
1603 	bpf_token_put(token);
1604 
1605 	err = bpf_map_new_fd(map, f_flags);
1606 	if (err < 0) {
1607 		/* failed to allocate fd.
1608 		 * bpf_map_put_with_uref() is needed because the above
1609 		 * bpf_map_alloc_id() has published the map
1610 		 * to the userspace and the userspace may
1611 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1612 		 */
1613 		bpf_map_put_with_uref(map);
1614 		return err;
1615 	}
1616 
1617 	return err;
1618 
1619 free_map_sec:
1620 	security_bpf_map_free(map);
1621 free_map:
1622 	bpf_map_free(map);
1623 put_token:
1624 	bpf_token_put(token);
1625 	return err;
1626 }
1627 
bpf_map_inc(struct bpf_map * map)1628 void bpf_map_inc(struct bpf_map *map)
1629 {
1630 	atomic64_inc(&map->refcnt);
1631 }
1632 EXPORT_SYMBOL_GPL(bpf_map_inc);
1633 
bpf_map_inc_with_uref(struct bpf_map * map)1634 void bpf_map_inc_with_uref(struct bpf_map *map)
1635 {
1636 	atomic64_inc(&map->refcnt);
1637 	atomic64_inc(&map->usercnt);
1638 }
1639 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1640 
bpf_map_get(u32 ufd)1641 struct bpf_map *bpf_map_get(u32 ufd)
1642 {
1643 	CLASS(fd, f)(ufd);
1644 	struct bpf_map *map = __bpf_map_get(f);
1645 
1646 	if (!IS_ERR(map))
1647 		bpf_map_inc(map);
1648 
1649 	return map;
1650 }
1651 EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL");
1652 
bpf_map_get_with_uref(u32 ufd)1653 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1654 {
1655 	CLASS(fd, f)(ufd);
1656 	struct bpf_map *map = __bpf_map_get(f);
1657 
1658 	if (!IS_ERR(map))
1659 		bpf_map_inc_with_uref(map);
1660 
1661 	return map;
1662 }
1663 
1664 /* map_idr_lock should have been held or the map should have been
1665  * protected by rcu read lock.
1666  */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1667 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1668 {
1669 	int refold;
1670 
1671 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1672 	if (!refold)
1673 		return ERR_PTR(-ENOENT);
1674 	if (uref)
1675 		atomic64_inc(&map->usercnt);
1676 
1677 	return map;
1678 }
1679 
bpf_map_inc_not_zero(struct bpf_map * map)1680 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1681 {
1682 	lockdep_assert(rcu_read_lock_held());
1683 	return __bpf_map_inc_not_zero(map, false);
1684 }
1685 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1686 
bpf_stackmap_extract(struct bpf_map * map,void * key,void * value,bool delete)1687 int __weak bpf_stackmap_extract(struct bpf_map *map, void *key, void *value,
1688 				bool delete)
1689 {
1690 	return -ENOTSUPP;
1691 }
1692 
__bpf_copy_key(void __user * ukey,u64 key_size)1693 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1694 {
1695 	if (key_size)
1696 		return vmemdup_user(ukey, key_size);
1697 
1698 	if (ukey)
1699 		return ERR_PTR(-EINVAL);
1700 
1701 	return NULL;
1702 }
1703 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1704 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1705 {
1706 	if (key_size)
1707 		return kvmemdup_bpfptr(ukey, key_size);
1708 
1709 	if (!bpfptr_is_null(ukey))
1710 		return ERR_PTR(-EINVAL);
1711 
1712 	return NULL;
1713 }
1714 
1715 /* last field in 'union bpf_attr' used by this command */
1716 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1717 
map_lookup_elem(union bpf_attr * attr)1718 static int map_lookup_elem(union bpf_attr *attr)
1719 {
1720 	void __user *ukey = u64_to_user_ptr(attr->key);
1721 	void __user *uvalue = u64_to_user_ptr(attr->value);
1722 	struct bpf_map *map;
1723 	void *key, *value;
1724 	u32 value_size;
1725 	int err;
1726 
1727 	if (CHECK_ATTR(BPF_MAP_LOOKUP_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 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1735 		return -EPERM;
1736 
1737 	err = bpf_map_check_op_flags(map, attr->flags, BPF_F_LOCK);
1738 	if (err)
1739 		return err;
1740 
1741 	key = __bpf_copy_key(ukey, map->key_size);
1742 	if (IS_ERR(key))
1743 		return PTR_ERR(key);
1744 
1745 	value_size = bpf_map_value_size(map);
1746 
1747 	err = -ENOMEM;
1748 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1749 	if (!value)
1750 		goto free_key;
1751 
1752 	if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1753 		if (copy_from_user(value, uvalue, value_size))
1754 			err = -EFAULT;
1755 		else
1756 			err = bpf_map_copy_value(map, key, value, attr->flags);
1757 		goto free_value;
1758 	}
1759 
1760 	err = bpf_map_copy_value(map, key, value, attr->flags);
1761 	if (err)
1762 		goto free_value;
1763 
1764 	err = -EFAULT;
1765 	if (copy_to_user(uvalue, value, value_size) != 0)
1766 		goto free_value;
1767 
1768 	err = 0;
1769 
1770 free_value:
1771 	kvfree(value);
1772 free_key:
1773 	kvfree(key);
1774 	return err;
1775 }
1776 
1777 
1778 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1779 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1780 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1781 {
1782 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1783 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1784 	struct bpf_map *map;
1785 	void *key, *value;
1786 	u32 value_size;
1787 	int err;
1788 
1789 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1790 		return -EINVAL;
1791 
1792 	CLASS(fd, f)(attr->map_fd);
1793 	map = __bpf_map_get(f);
1794 	if (IS_ERR(map))
1795 		return PTR_ERR(map);
1796 	bpf_map_write_active_inc(map);
1797 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1798 		err = -EPERM;
1799 		goto err_put;
1800 	}
1801 
1802 	err = bpf_map_check_op_flags(map, attr->flags, ~0);
1803 	if (err)
1804 		goto err_put;
1805 
1806 	key = ___bpf_copy_key(ukey, map->key_size);
1807 	if (IS_ERR(key)) {
1808 		err = PTR_ERR(key);
1809 		goto err_put;
1810 	}
1811 
1812 	value_size = bpf_map_value_size(map);
1813 	value = kvmemdup_bpfptr(uvalue, value_size);
1814 	if (IS_ERR(value)) {
1815 		err = PTR_ERR(value);
1816 		goto free_key;
1817 	}
1818 
1819 	err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
1820 	if (!err)
1821 		maybe_wait_bpf_programs(map);
1822 
1823 	kvfree(value);
1824 free_key:
1825 	kvfree(key);
1826 err_put:
1827 	bpf_map_write_active_dec(map);
1828 	return err;
1829 }
1830 
1831 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1832 
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1833 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1834 {
1835 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1836 	struct bpf_map *map;
1837 	void *key;
1838 	int err;
1839 
1840 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1841 		return -EINVAL;
1842 
1843 	CLASS(fd, f)(attr->map_fd);
1844 	map = __bpf_map_get(f);
1845 	if (IS_ERR(map))
1846 		return PTR_ERR(map);
1847 	bpf_map_write_active_inc(map);
1848 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1849 		err = -EPERM;
1850 		goto err_put;
1851 	}
1852 
1853 	key = ___bpf_copy_key(ukey, map->key_size);
1854 	if (IS_ERR(key)) {
1855 		err = PTR_ERR(key);
1856 		goto err_put;
1857 	}
1858 
1859 	if (bpf_map_is_offloaded(map)) {
1860 		err = bpf_map_offload_delete_elem(map, key);
1861 		goto out;
1862 	} else if (IS_FD_PROG_ARRAY(map) ||
1863 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1864 		/* These maps require sleepable context */
1865 		err = map->ops->map_delete_elem(map, key);
1866 		goto out;
1867 	}
1868 
1869 	bpf_disable_instrumentation();
1870 	rcu_read_lock();
1871 	err = map->ops->map_delete_elem(map, key);
1872 	rcu_read_unlock();
1873 	bpf_enable_instrumentation();
1874 	if (!err)
1875 		maybe_wait_bpf_programs(map);
1876 out:
1877 	kvfree(key);
1878 err_put:
1879 	bpf_map_write_active_dec(map);
1880 	return err;
1881 }
1882 
1883 /* last field in 'union bpf_attr' used by this command */
1884 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1885 
map_get_next_key(union bpf_attr * attr)1886 static int map_get_next_key(union bpf_attr *attr)
1887 {
1888 	void __user *ukey = u64_to_user_ptr(attr->key);
1889 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1890 	struct bpf_map *map;
1891 	void *key, *next_key;
1892 	int err;
1893 
1894 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1895 		return -EINVAL;
1896 
1897 	CLASS(fd, f)(attr->map_fd);
1898 	map = __bpf_map_get(f);
1899 	if (IS_ERR(map))
1900 		return PTR_ERR(map);
1901 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
1902 		return -EPERM;
1903 
1904 	if (ukey) {
1905 		key = __bpf_copy_key(ukey, map->key_size);
1906 		if (IS_ERR(key))
1907 			return PTR_ERR(key);
1908 	} else {
1909 		key = NULL;
1910 	}
1911 
1912 	err = -ENOMEM;
1913 	next_key = kvmalloc(map->key_size, GFP_USER);
1914 	if (!next_key)
1915 		goto free_key;
1916 
1917 	if (bpf_map_is_offloaded(map)) {
1918 		err = bpf_map_offload_get_next_key(map, key, next_key);
1919 		goto out;
1920 	}
1921 
1922 	rcu_read_lock();
1923 	err = map->ops->map_get_next_key(map, key, next_key);
1924 	rcu_read_unlock();
1925 out:
1926 	if (err)
1927 		goto free_next_key;
1928 
1929 	err = -EFAULT;
1930 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1931 		goto free_next_key;
1932 
1933 	err = 0;
1934 
1935 free_next_key:
1936 	kvfree(next_key);
1937 free_key:
1938 	kvfree(key);
1939 	return err;
1940 }
1941 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1942 int generic_map_delete_batch(struct bpf_map *map,
1943 			     const union bpf_attr *attr,
1944 			     union bpf_attr __user *uattr)
1945 {
1946 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1947 	u32 cp, max_count;
1948 	int err = 0;
1949 	void *key;
1950 
1951 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1952 		return -EINVAL;
1953 
1954 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1955 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1956 		return -EINVAL;
1957 	}
1958 
1959 	max_count = attr->batch.count;
1960 	if (!max_count)
1961 		return 0;
1962 
1963 	if (put_user(0, &uattr->batch.count))
1964 		return -EFAULT;
1965 
1966 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1967 	if (!key)
1968 		return -ENOMEM;
1969 
1970 	for (cp = 0; cp < max_count; cp++) {
1971 		err = -EFAULT;
1972 		if (copy_from_user(key, keys + cp * map->key_size,
1973 				   map->key_size))
1974 			break;
1975 
1976 		if (bpf_map_is_offloaded(map)) {
1977 			err = bpf_map_offload_delete_elem(map, key);
1978 			break;
1979 		}
1980 
1981 		bpf_disable_instrumentation();
1982 		rcu_read_lock();
1983 		err = map->ops->map_delete_elem(map, key);
1984 		rcu_read_unlock();
1985 		bpf_enable_instrumentation();
1986 		if (err)
1987 			break;
1988 		cond_resched();
1989 	}
1990 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1991 		err = -EFAULT;
1992 
1993 	kvfree(key);
1994 
1995 	return err;
1996 }
1997 
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1998 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1999 			     const union bpf_attr *attr,
2000 			     union bpf_attr __user *uattr)
2001 {
2002 	void __user *values = u64_to_user_ptr(attr->batch.values);
2003 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
2004 	u32 value_size, cp, max_count;
2005 	void *key, *value;
2006 	int err = 0;
2007 
2008 	err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK);
2009 	if (err)
2010 		return err;
2011 
2012 	value_size = bpf_map_value_size(map);
2013 
2014 	max_count = attr->batch.count;
2015 	if (!max_count)
2016 		return 0;
2017 
2018 	if (put_user(0, &uattr->batch.count))
2019 		return -EFAULT;
2020 
2021 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2022 	if (!key)
2023 		return -ENOMEM;
2024 
2025 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2026 	if (!value) {
2027 		kvfree(key);
2028 		return -ENOMEM;
2029 	}
2030 
2031 	for (cp = 0; cp < max_count; cp++) {
2032 		err = -EFAULT;
2033 		if (copy_from_user(key, keys + cp * map->key_size,
2034 		    map->key_size) ||
2035 		    copy_from_user(value, values + cp * value_size, value_size))
2036 			break;
2037 
2038 		err = bpf_map_update_value(map, map_file, key, value,
2039 					   attr->batch.elem_flags);
2040 
2041 		if (err)
2042 			break;
2043 		cond_resched();
2044 	}
2045 
2046 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
2047 		err = -EFAULT;
2048 
2049 	kvfree(value);
2050 	kvfree(key);
2051 
2052 	return err;
2053 }
2054 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)2055 int generic_map_lookup_batch(struct bpf_map *map,
2056 				    const union bpf_attr *attr,
2057 				    union bpf_attr __user *uattr)
2058 {
2059 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
2060 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
2061 	void __user *values = u64_to_user_ptr(attr->batch.values);
2062 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
2063 	void *buf, *buf_prevkey, *prev_key, *key, *value;
2064 	u32 value_size, cp, max_count;
2065 	int err;
2066 
2067 	err = bpf_map_check_op_flags(map, attr->batch.elem_flags, BPF_F_LOCK);
2068 	if (err)
2069 		return err;
2070 
2071 	value_size = bpf_map_value_size(map);
2072 
2073 	max_count = attr->batch.count;
2074 	if (!max_count)
2075 		return 0;
2076 
2077 	if (put_user(0, &uattr->batch.count))
2078 		return -EFAULT;
2079 
2080 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
2081 	if (!buf_prevkey)
2082 		return -ENOMEM;
2083 
2084 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
2085 	if (!buf) {
2086 		kvfree(buf_prevkey);
2087 		return -ENOMEM;
2088 	}
2089 
2090 	err = -EFAULT;
2091 	prev_key = NULL;
2092 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
2093 		goto free_buf;
2094 	key = buf;
2095 	value = key + map->key_size;
2096 	if (ubatch)
2097 		prev_key = buf_prevkey;
2098 
2099 	for (cp = 0; cp < max_count;) {
2100 		rcu_read_lock();
2101 		err = map->ops->map_get_next_key(map, prev_key, key);
2102 		rcu_read_unlock();
2103 		if (err)
2104 			break;
2105 		err = bpf_map_copy_value(map, key, value,
2106 					 attr->batch.elem_flags);
2107 
2108 		if (err == -ENOENT)
2109 			goto next_key;
2110 
2111 		if (err)
2112 			goto free_buf;
2113 
2114 		if (copy_to_user(keys + cp * map->key_size, key,
2115 				 map->key_size)) {
2116 			err = -EFAULT;
2117 			goto free_buf;
2118 		}
2119 		if (copy_to_user(values + cp * value_size, value, value_size)) {
2120 			err = -EFAULT;
2121 			goto free_buf;
2122 		}
2123 
2124 		cp++;
2125 next_key:
2126 		if (!prev_key)
2127 			prev_key = buf_prevkey;
2128 
2129 		swap(prev_key, key);
2130 		cond_resched();
2131 	}
2132 
2133 	if (err == -EFAULT)
2134 		goto free_buf;
2135 
2136 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
2137 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2138 		err = -EFAULT;
2139 
2140 free_buf:
2141 	kvfree(buf_prevkey);
2142 	kvfree(buf);
2143 	return err;
2144 }
2145 
2146 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2147 
map_lookup_and_delete_elem(union bpf_attr * attr)2148 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2149 {
2150 	void __user *ukey = u64_to_user_ptr(attr->key);
2151 	void __user *uvalue = u64_to_user_ptr(attr->value);
2152 	struct bpf_map *map;
2153 	void *key, *value;
2154 	u32 value_size;
2155 	int err;
2156 
2157 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2158 		return -EINVAL;
2159 
2160 	if (attr->flags & ~BPF_F_LOCK)
2161 		return -EINVAL;
2162 
2163 	CLASS(fd, f)(attr->map_fd);
2164 	map = __bpf_map_get(f);
2165 	if (IS_ERR(map))
2166 		return PTR_ERR(map);
2167 	bpf_map_write_active_inc(map);
2168 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2169 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2170 		err = -EPERM;
2171 		goto err_put;
2172 	}
2173 
2174 	if (attr->flags &&
2175 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
2176 	     map->map_type == BPF_MAP_TYPE_STACK)) {
2177 		err = -EINVAL;
2178 		goto err_put;
2179 	}
2180 
2181 	if ((attr->flags & BPF_F_LOCK) &&
2182 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2183 		err = -EINVAL;
2184 		goto err_put;
2185 	}
2186 
2187 	key = __bpf_copy_key(ukey, map->key_size);
2188 	if (IS_ERR(key)) {
2189 		err = PTR_ERR(key);
2190 		goto err_put;
2191 	}
2192 
2193 	value_size = bpf_map_value_size(map);
2194 
2195 	err = -ENOMEM;
2196 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2197 	if (!value)
2198 		goto free_key;
2199 
2200 	err = -ENOTSUPP;
2201 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2202 	    map->map_type == BPF_MAP_TYPE_STACK) {
2203 		err = map->ops->map_pop_elem(map, value);
2204 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
2205 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2206 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2207 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
2208 		   map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
2209 		if (!bpf_map_is_offloaded(map)) {
2210 			bpf_disable_instrumentation();
2211 			rcu_read_lock();
2212 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2213 			rcu_read_unlock();
2214 			bpf_enable_instrumentation();
2215 		}
2216 	}
2217 
2218 	if (err)
2219 		goto free_value;
2220 
2221 	if (copy_to_user(uvalue, value, value_size) != 0) {
2222 		err = -EFAULT;
2223 		goto free_value;
2224 	}
2225 
2226 	err = 0;
2227 
2228 free_value:
2229 	kvfree(value);
2230 free_key:
2231 	kvfree(key);
2232 err_put:
2233 	bpf_map_write_active_dec(map);
2234 	return err;
2235 }
2236 
2237 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2238 
map_freeze(const union bpf_attr * attr)2239 static int map_freeze(const union bpf_attr *attr)
2240 {
2241 	int err = 0;
2242 	struct bpf_map *map;
2243 
2244 	if (CHECK_ATTR(BPF_MAP_FREEZE))
2245 		return -EINVAL;
2246 
2247 	CLASS(fd, f)(attr->map_fd);
2248 	map = __bpf_map_get(f);
2249 	if (IS_ERR(map))
2250 		return PTR_ERR(map);
2251 
2252 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
2253 		return -ENOTSUPP;
2254 
2255 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
2256 		return -EPERM;
2257 
2258 	mutex_lock(&map->freeze_mutex);
2259 	if (bpf_map_write_active(map)) {
2260 		err = -EBUSY;
2261 		goto err_put;
2262 	}
2263 	if (READ_ONCE(map->frozen)) {
2264 		err = -EBUSY;
2265 		goto err_put;
2266 	}
2267 
2268 	WRITE_ONCE(map->frozen, true);
2269 err_put:
2270 	mutex_unlock(&map->freeze_mutex);
2271 	return err;
2272 }
2273 
2274 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2275 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2276 	[_id] = & _name ## _prog_ops,
2277 #define BPF_MAP_TYPE(_id, _ops)
2278 #define BPF_LINK_TYPE(_id, _name)
2279 #include <linux/bpf_types.h>
2280 #undef BPF_PROG_TYPE
2281 #undef BPF_MAP_TYPE
2282 #undef BPF_LINK_TYPE
2283 };
2284 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2285 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2286 {
2287 	const struct bpf_prog_ops *ops;
2288 
2289 	if (type >= ARRAY_SIZE(bpf_prog_types))
2290 		return -EINVAL;
2291 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2292 	ops = bpf_prog_types[type];
2293 	if (!ops)
2294 		return -EINVAL;
2295 
2296 	if (!bpf_prog_is_offloaded(prog->aux))
2297 		prog->aux->ops = ops;
2298 	else
2299 		prog->aux->ops = &bpf_offload_prog_ops;
2300 	prog->type = type;
2301 	return 0;
2302 }
2303 
2304 enum bpf_audit {
2305 	BPF_AUDIT_LOAD,
2306 	BPF_AUDIT_UNLOAD,
2307 	BPF_AUDIT_MAX,
2308 };
2309 
2310 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2311 	[BPF_AUDIT_LOAD]   = "LOAD",
2312 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
2313 };
2314 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2315 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2316 {
2317 	struct audit_context *ctx = NULL;
2318 	struct audit_buffer *ab;
2319 
2320 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2321 		return;
2322 	if (audit_enabled == AUDIT_OFF)
2323 		return;
2324 	if (!in_hardirq() && !irqs_disabled())
2325 		ctx = audit_context();
2326 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2327 	if (unlikely(!ab))
2328 		return;
2329 	audit_log_format(ab, "prog-id=%u op=%s",
2330 			 prog->aux->id, bpf_audit_str[op]);
2331 	audit_log_end(ab);
2332 }
2333 
bpf_prog_alloc_id(struct bpf_prog * prog)2334 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2335 {
2336 	int id;
2337 
2338 	idr_preload(GFP_KERNEL);
2339 	spin_lock_bh(&prog_idr_lock);
2340 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2341 	if (id > 0)
2342 		prog->aux->id = id;
2343 	spin_unlock_bh(&prog_idr_lock);
2344 	idr_preload_end();
2345 
2346 	/* id is in [1, INT_MAX) */
2347 	if (WARN_ON_ONCE(!id))
2348 		return -ENOSPC;
2349 
2350 	return id > 0 ? 0 : id;
2351 }
2352 
bpf_prog_free_id(struct bpf_prog * prog)2353 void bpf_prog_free_id(struct bpf_prog *prog)
2354 {
2355 	unsigned long flags;
2356 
2357 	/* cBPF to eBPF migrations are currently not in the idr store.
2358 	 * Offloaded programs are removed from the store when their device
2359 	 * disappears - even if someone grabs an fd to them they are unusable,
2360 	 * simply waiting for refcnt to drop to be freed.
2361 	 */
2362 	if (!prog->aux->id)
2363 		return;
2364 
2365 	spin_lock_irqsave(&prog_idr_lock, flags);
2366 	idr_remove(&prog_idr, prog->aux->id);
2367 	prog->aux->id = 0;
2368 	spin_unlock_irqrestore(&prog_idr_lock, flags);
2369 }
2370 
__bpf_prog_put_rcu(struct rcu_head * rcu)2371 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2372 {
2373 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2374 
2375 	kvfree(aux->func_info);
2376 	kfree(aux->func_info_aux);
2377 	free_uid(aux->user);
2378 	security_bpf_prog_free(aux->prog);
2379 	bpf_prog_free(aux->prog);
2380 }
2381 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2382 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2383 {
2384 	bpf_prog_kallsyms_del_all(prog);
2385 	btf_put(prog->aux->btf);
2386 	module_put(prog->aux->mod);
2387 	kvfree(prog->aux->jited_linfo);
2388 	kvfree(prog->aux->linfo);
2389 	kfree(prog->aux->kfunc_tab);
2390 	kfree(prog->aux->ctx_arg_info);
2391 	if (prog->aux->attach_btf)
2392 		btf_put(prog->aux->attach_btf);
2393 
2394 	if (deferred) {
2395 		if (prog->sleepable)
2396 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2397 		else
2398 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2399 	} else {
2400 		__bpf_prog_put_rcu(&prog->aux->rcu);
2401 	}
2402 }
2403 
bpf_prog_put_deferred(struct work_struct * work)2404 static void bpf_prog_put_deferred(struct work_struct *work)
2405 {
2406 	struct bpf_prog_aux *aux;
2407 	struct bpf_prog *prog;
2408 
2409 	aux = container_of(work, struct bpf_prog_aux, work);
2410 	prog = aux->prog;
2411 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2412 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2413 	bpf_prog_free_id(prog);
2414 	__bpf_prog_put_noref(prog, true);
2415 }
2416 
__bpf_prog_put(struct bpf_prog * prog)2417 static void __bpf_prog_put(struct bpf_prog *prog)
2418 {
2419 	struct bpf_prog_aux *aux = prog->aux;
2420 
2421 	if (atomic64_dec_and_test(&aux->refcnt)) {
2422 		if (in_hardirq() || irqs_disabled()) {
2423 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
2424 			schedule_work(&aux->work);
2425 		} else {
2426 			bpf_prog_put_deferred(&aux->work);
2427 		}
2428 	}
2429 }
2430 
bpf_prog_put(struct bpf_prog * prog)2431 void bpf_prog_put(struct bpf_prog *prog)
2432 {
2433 	__bpf_prog_put(prog);
2434 }
2435 EXPORT_SYMBOL_GPL(bpf_prog_put);
2436 
bpf_prog_release(struct inode * inode,struct file * filp)2437 static int bpf_prog_release(struct inode *inode, struct file *filp)
2438 {
2439 	struct bpf_prog *prog = filp->private_data;
2440 
2441 	bpf_prog_put(prog);
2442 	return 0;
2443 }
2444 
2445 struct bpf_prog_kstats {
2446 	u64 nsecs;
2447 	u64 cnt;
2448 	u64 misses;
2449 };
2450 
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2451 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2452 {
2453 	struct bpf_prog_stats *stats;
2454 	unsigned int flags;
2455 
2456 	if (unlikely(!prog->stats))
2457 		return;
2458 
2459 	stats = this_cpu_ptr(prog->stats);
2460 	flags = u64_stats_update_begin_irqsave(&stats->syncp);
2461 	u64_stats_inc(&stats->misses);
2462 	u64_stats_update_end_irqrestore(&stats->syncp, flags);
2463 }
2464 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2465 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2466 			       struct bpf_prog_kstats *stats)
2467 {
2468 	u64 nsecs = 0, cnt = 0, misses = 0;
2469 	int cpu;
2470 
2471 	for_each_possible_cpu(cpu) {
2472 		const struct bpf_prog_stats *st;
2473 		unsigned int start;
2474 		u64 tnsecs, tcnt, tmisses;
2475 
2476 		st = per_cpu_ptr(prog->stats, cpu);
2477 		do {
2478 			start = u64_stats_fetch_begin(&st->syncp);
2479 			tnsecs = u64_stats_read(&st->nsecs);
2480 			tcnt = u64_stats_read(&st->cnt);
2481 			tmisses = u64_stats_read(&st->misses);
2482 		} while (u64_stats_fetch_retry(&st->syncp, start));
2483 		nsecs += tnsecs;
2484 		cnt += tcnt;
2485 		misses += tmisses;
2486 	}
2487 	stats->nsecs = nsecs;
2488 	stats->cnt = cnt;
2489 	stats->misses = misses;
2490 }
2491 
2492 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2493 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2494 {
2495 	const struct bpf_prog *prog = filp->private_data;
2496 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2497 	struct bpf_prog_kstats stats;
2498 
2499 	bpf_prog_get_stats(prog, &stats);
2500 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2501 	seq_printf(m,
2502 		   "prog_type:\t%u\n"
2503 		   "prog_jited:\t%u\n"
2504 		   "prog_tag:\t%s\n"
2505 		   "memlock:\t%llu\n"
2506 		   "prog_id:\t%u\n"
2507 		   "run_time_ns:\t%llu\n"
2508 		   "run_cnt:\t%llu\n"
2509 		   "recursion_misses:\t%llu\n"
2510 		   "verified_insns:\t%u\n",
2511 		   prog->type,
2512 		   prog->jited,
2513 		   prog_tag,
2514 		   prog->pages * 1ULL << PAGE_SHIFT,
2515 		   prog->aux->id,
2516 		   stats.nsecs,
2517 		   stats.cnt,
2518 		   stats.misses,
2519 		   prog->aux->verified_insns);
2520 }
2521 #endif
2522 
2523 const struct file_operations bpf_prog_fops = {
2524 #ifdef CONFIG_PROC_FS
2525 	.show_fdinfo	= bpf_prog_show_fdinfo,
2526 #endif
2527 	.release	= bpf_prog_release,
2528 	.read		= bpf_dummy_read,
2529 	.write		= bpf_dummy_write,
2530 };
2531 
bpf_prog_new_fd(struct bpf_prog * prog)2532 int bpf_prog_new_fd(struct bpf_prog *prog)
2533 {
2534 	int ret;
2535 
2536 	ret = security_bpf_prog(prog);
2537 	if (ret < 0)
2538 		return ret;
2539 
2540 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2541 				O_RDWR | O_CLOEXEC);
2542 }
2543 
bpf_prog_add(struct bpf_prog * prog,int i)2544 void bpf_prog_add(struct bpf_prog *prog, int i)
2545 {
2546 	atomic64_add(i, &prog->aux->refcnt);
2547 }
2548 EXPORT_SYMBOL_GPL(bpf_prog_add);
2549 
bpf_prog_sub(struct bpf_prog * prog,int i)2550 void bpf_prog_sub(struct bpf_prog *prog, int i)
2551 {
2552 	/* Only to be used for undoing previous bpf_prog_add() in some
2553 	 * error path. We still know that another entity in our call
2554 	 * path holds a reference to the program, thus atomic_sub() can
2555 	 * be safely used in such cases!
2556 	 */
2557 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2558 }
2559 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2560 
bpf_prog_inc(struct bpf_prog * prog)2561 void bpf_prog_inc(struct bpf_prog *prog)
2562 {
2563 	atomic64_inc(&prog->aux->refcnt);
2564 }
2565 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2566 
2567 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2568 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2569 {
2570 	int refold;
2571 
2572 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2573 
2574 	if (!refold)
2575 		return ERR_PTR(-ENOENT);
2576 
2577 	return prog;
2578 }
2579 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2580 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2581 bool bpf_prog_get_ok(struct bpf_prog *prog,
2582 			    enum bpf_prog_type *attach_type, bool attach_drv)
2583 {
2584 	/* not an attachment, just a refcount inc, always allow */
2585 	if (!attach_type)
2586 		return true;
2587 
2588 	if (prog->type != *attach_type)
2589 		return false;
2590 	if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2591 		return false;
2592 
2593 	return true;
2594 }
2595 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2596 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2597 				       bool attach_drv)
2598 {
2599 	CLASS(fd, f)(ufd);
2600 	struct bpf_prog *prog;
2601 
2602 	if (fd_empty(f))
2603 		return ERR_PTR(-EBADF);
2604 	if (fd_file(f)->f_op != &bpf_prog_fops)
2605 		return ERR_PTR(-EINVAL);
2606 
2607 	prog = fd_file(f)->private_data;
2608 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
2609 		return ERR_PTR(-EINVAL);
2610 
2611 	bpf_prog_inc(prog);
2612 	return prog;
2613 }
2614 
bpf_prog_get(u32 ufd)2615 struct bpf_prog *bpf_prog_get(u32 ufd)
2616 {
2617 	return __bpf_prog_get(ufd, NULL, false);
2618 }
2619 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2620 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2621 				       bool attach_drv)
2622 {
2623 	return __bpf_prog_get(ufd, &type, attach_drv);
2624 }
2625 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2626 
2627 /* Initially all BPF programs could be loaded w/o specifying
2628  * expected_attach_type. Later for some of them specifying expected_attach_type
2629  * at load time became required so that program could be validated properly.
2630  * Programs of types that are allowed to be loaded both w/ and w/o (for
2631  * backward compatibility) expected_attach_type, should have the default attach
2632  * type assigned to expected_attach_type for the latter case, so that it can be
2633  * validated later at attach time.
2634  *
2635  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2636  * prog type requires it but has some attach types that have to be backward
2637  * compatible.
2638  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2639 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2640 {
2641 	switch (attr->prog_type) {
2642 	case BPF_PROG_TYPE_CGROUP_SOCK:
2643 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2644 		 * exist so checking for non-zero is the way to go here.
2645 		 */
2646 		if (!attr->expected_attach_type)
2647 			attr->expected_attach_type =
2648 				BPF_CGROUP_INET_SOCK_CREATE;
2649 		break;
2650 	case BPF_PROG_TYPE_SK_REUSEPORT:
2651 		if (!attr->expected_attach_type)
2652 			attr->expected_attach_type =
2653 				BPF_SK_REUSEPORT_SELECT;
2654 		break;
2655 	}
2656 }
2657 
2658 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)2659 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2660 			   enum bpf_attach_type expected_attach_type,
2661 			   struct btf *attach_btf, u32 btf_id,
2662 			   struct bpf_prog *dst_prog)
2663 {
2664 	if (btf_id) {
2665 		if (btf_id > BTF_MAX_TYPE)
2666 			return -EINVAL;
2667 
2668 		if (!attach_btf && !dst_prog)
2669 			return -EINVAL;
2670 
2671 		switch (prog_type) {
2672 		case BPF_PROG_TYPE_TRACING:
2673 		case BPF_PROG_TYPE_LSM:
2674 		case BPF_PROG_TYPE_STRUCT_OPS:
2675 		case BPF_PROG_TYPE_EXT:
2676 			break;
2677 		default:
2678 			return -EINVAL;
2679 		}
2680 	}
2681 
2682 	if (attach_btf && (!btf_id || dst_prog))
2683 		return -EINVAL;
2684 
2685 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2686 	    prog_type != BPF_PROG_TYPE_EXT)
2687 		return -EINVAL;
2688 
2689 	switch (prog_type) {
2690 	case BPF_PROG_TYPE_CGROUP_SOCK:
2691 		switch (expected_attach_type) {
2692 		case BPF_CGROUP_INET_SOCK_CREATE:
2693 		case BPF_CGROUP_INET_SOCK_RELEASE:
2694 		case BPF_CGROUP_INET4_POST_BIND:
2695 		case BPF_CGROUP_INET6_POST_BIND:
2696 			return 0;
2697 		default:
2698 			return -EINVAL;
2699 		}
2700 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2701 		switch (expected_attach_type) {
2702 		case BPF_CGROUP_INET4_BIND:
2703 		case BPF_CGROUP_INET6_BIND:
2704 		case BPF_CGROUP_INET4_CONNECT:
2705 		case BPF_CGROUP_INET6_CONNECT:
2706 		case BPF_CGROUP_UNIX_CONNECT:
2707 		case BPF_CGROUP_INET4_GETPEERNAME:
2708 		case BPF_CGROUP_INET6_GETPEERNAME:
2709 		case BPF_CGROUP_UNIX_GETPEERNAME:
2710 		case BPF_CGROUP_INET4_GETSOCKNAME:
2711 		case BPF_CGROUP_INET6_GETSOCKNAME:
2712 		case BPF_CGROUP_UNIX_GETSOCKNAME:
2713 		case BPF_CGROUP_UDP4_SENDMSG:
2714 		case BPF_CGROUP_UDP6_SENDMSG:
2715 		case BPF_CGROUP_UNIX_SENDMSG:
2716 		case BPF_CGROUP_UDP4_RECVMSG:
2717 		case BPF_CGROUP_UDP6_RECVMSG:
2718 		case BPF_CGROUP_UNIX_RECVMSG:
2719 			return 0;
2720 		default:
2721 			return -EINVAL;
2722 		}
2723 	case BPF_PROG_TYPE_CGROUP_SKB:
2724 		switch (expected_attach_type) {
2725 		case BPF_CGROUP_INET_INGRESS:
2726 		case BPF_CGROUP_INET_EGRESS:
2727 			return 0;
2728 		default:
2729 			return -EINVAL;
2730 		}
2731 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2732 		switch (expected_attach_type) {
2733 		case BPF_CGROUP_SETSOCKOPT:
2734 		case BPF_CGROUP_GETSOCKOPT:
2735 			return 0;
2736 		default:
2737 			return -EINVAL;
2738 		}
2739 	case BPF_PROG_TYPE_SK_LOOKUP:
2740 		if (expected_attach_type == BPF_SK_LOOKUP)
2741 			return 0;
2742 		return -EINVAL;
2743 	case BPF_PROG_TYPE_SK_REUSEPORT:
2744 		switch (expected_attach_type) {
2745 		case BPF_SK_REUSEPORT_SELECT:
2746 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2747 			return 0;
2748 		default:
2749 			return -EINVAL;
2750 		}
2751 	case BPF_PROG_TYPE_NETFILTER:
2752 		if (expected_attach_type == BPF_NETFILTER)
2753 			return 0;
2754 		return -EINVAL;
2755 	case BPF_PROG_TYPE_SYSCALL:
2756 	case BPF_PROG_TYPE_EXT:
2757 		if (expected_attach_type)
2758 			return -EINVAL;
2759 		fallthrough;
2760 	default:
2761 		return 0;
2762 	}
2763 }
2764 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2765 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2766 {
2767 	switch (prog_type) {
2768 	case BPF_PROG_TYPE_SCHED_CLS:
2769 	case BPF_PROG_TYPE_SCHED_ACT:
2770 	case BPF_PROG_TYPE_XDP:
2771 	case BPF_PROG_TYPE_LWT_IN:
2772 	case BPF_PROG_TYPE_LWT_OUT:
2773 	case BPF_PROG_TYPE_LWT_XMIT:
2774 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2775 	case BPF_PROG_TYPE_SK_SKB:
2776 	case BPF_PROG_TYPE_SK_MSG:
2777 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2778 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2779 	case BPF_PROG_TYPE_CGROUP_SOCK:
2780 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2781 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2782 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2783 	case BPF_PROG_TYPE_SOCK_OPS:
2784 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2785 	case BPF_PROG_TYPE_NETFILTER:
2786 		return true;
2787 	case BPF_PROG_TYPE_CGROUP_SKB:
2788 		/* always unpriv */
2789 	case BPF_PROG_TYPE_SK_REUSEPORT:
2790 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2791 	default:
2792 		return false;
2793 	}
2794 }
2795 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2796 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2797 {
2798 	switch (prog_type) {
2799 	case BPF_PROG_TYPE_KPROBE:
2800 	case BPF_PROG_TYPE_TRACEPOINT:
2801 	case BPF_PROG_TYPE_PERF_EVENT:
2802 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2803 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2804 	case BPF_PROG_TYPE_TRACING:
2805 	case BPF_PROG_TYPE_LSM:
2806 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2807 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2808 		return true;
2809 	default:
2810 		return false;
2811 	}
2812 }
2813 
bpf_prog_verify_signature(struct bpf_prog * prog,union bpf_attr * attr,bool is_kernel)2814 static int bpf_prog_verify_signature(struct bpf_prog *prog, union bpf_attr *attr,
2815 				     bool is_kernel)
2816 {
2817 	bpfptr_t usig = make_bpfptr(attr->signature, is_kernel);
2818 	struct bpf_dynptr_kern sig_ptr, insns_ptr;
2819 	struct bpf_key *key = NULL;
2820 	void *sig;
2821 	int err = 0;
2822 
2823 	if (system_keyring_id_check(attr->keyring_id) == 0)
2824 		key = bpf_lookup_system_key(attr->keyring_id);
2825 	else
2826 		key = bpf_lookup_user_key(attr->keyring_id, 0);
2827 
2828 	if (!key)
2829 		return -EINVAL;
2830 
2831 	sig = kvmemdup_bpfptr(usig, attr->signature_size);
2832 	if (IS_ERR(sig)) {
2833 		bpf_key_put(key);
2834 		return -ENOMEM;
2835 	}
2836 
2837 	bpf_dynptr_init(&sig_ptr, sig, BPF_DYNPTR_TYPE_LOCAL, 0,
2838 			attr->signature_size);
2839 	bpf_dynptr_init(&insns_ptr, prog->insnsi, BPF_DYNPTR_TYPE_LOCAL, 0,
2840 			prog->len * sizeof(struct bpf_insn));
2841 
2842 	err = bpf_verify_pkcs7_signature((struct bpf_dynptr *)&insns_ptr,
2843 					 (struct bpf_dynptr *)&sig_ptr, key);
2844 
2845 	bpf_key_put(key);
2846 	kvfree(sig);
2847 	return err;
2848 }
2849 
bpf_prog_mark_insn_arrays_ready(struct bpf_prog * prog)2850 static int bpf_prog_mark_insn_arrays_ready(struct bpf_prog *prog)
2851 {
2852 	int err;
2853 	int i;
2854 
2855 	for (i = 0; i < prog->aux->used_map_cnt; i++) {
2856 		if (prog->aux->used_maps[i]->map_type != BPF_MAP_TYPE_INSN_ARRAY)
2857 			continue;
2858 
2859 		err = bpf_insn_array_ready(prog->aux->used_maps[i]);
2860 		if (err)
2861 			return err;
2862 	}
2863 
2864 	return 0;
2865 }
2866 
2867 /* last field in 'union bpf_attr' used by this command */
2868 #define BPF_PROG_LOAD_LAST_FIELD keyring_id
2869 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2870 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2871 {
2872 	enum bpf_prog_type type = attr->prog_type;
2873 	struct bpf_prog *prog, *dst_prog = NULL;
2874 	struct btf *attach_btf = NULL;
2875 	struct bpf_token *token = NULL;
2876 	bool bpf_cap;
2877 	int err;
2878 	char license[128];
2879 
2880 	if (CHECK_ATTR(BPF_PROG_LOAD))
2881 		return -EINVAL;
2882 
2883 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2884 				 BPF_F_ANY_ALIGNMENT |
2885 				 BPF_F_TEST_STATE_FREQ |
2886 				 BPF_F_SLEEPABLE |
2887 				 BPF_F_TEST_RND_HI32 |
2888 				 BPF_F_XDP_HAS_FRAGS |
2889 				 BPF_F_XDP_DEV_BOUND_ONLY |
2890 				 BPF_F_TEST_REG_INVARIANTS |
2891 				 BPF_F_TOKEN_FD))
2892 		return -EINVAL;
2893 
2894 	bpf_prog_load_fixup_attach_type(attr);
2895 
2896 	if (attr->prog_flags & BPF_F_TOKEN_FD) {
2897 		token = bpf_token_get_from_fd(attr->prog_token_fd);
2898 		if (IS_ERR(token))
2899 			return PTR_ERR(token);
2900 		/* if current token doesn't grant prog loading permissions,
2901 		 * then we can't use this token, so ignore it and rely on
2902 		 * system-wide capabilities checks
2903 		 */
2904 		if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2905 		    !bpf_token_allow_prog_type(token, attr->prog_type,
2906 					       attr->expected_attach_type)) {
2907 			bpf_token_put(token);
2908 			token = NULL;
2909 		}
2910 	}
2911 
2912 	bpf_cap = bpf_token_capable(token, CAP_BPF);
2913 	err = -EPERM;
2914 
2915 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2916 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2917 	    !bpf_cap)
2918 		goto put_token;
2919 
2920 	/* Intent here is for unprivileged_bpf_disabled to block BPF program
2921 	 * creation for unprivileged users; other actions depend
2922 	 * on fd availability and access to bpffs, so are dependent on
2923 	 * object creation success. Even with unprivileged BPF disabled,
2924 	 * capability checks are still carried out for these
2925 	 * and other operations.
2926 	 */
2927 	if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2928 		goto put_token;
2929 
2930 	if (attr->insn_cnt == 0 ||
2931 	    attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2932 		err = -E2BIG;
2933 		goto put_token;
2934 	}
2935 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2936 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2937 	    !bpf_cap)
2938 		goto put_token;
2939 
2940 	if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2941 		goto put_token;
2942 	if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2943 		goto put_token;
2944 
2945 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2946 	 * or btf, we need to check which one it is
2947 	 */
2948 	if (attr->attach_prog_fd) {
2949 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2950 		if (IS_ERR(dst_prog)) {
2951 			dst_prog = NULL;
2952 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2953 			if (IS_ERR(attach_btf)) {
2954 				err = -EINVAL;
2955 				goto put_token;
2956 			}
2957 			if (!btf_is_kernel(attach_btf)) {
2958 				/* attaching through specifying bpf_prog's BTF
2959 				 * objects directly might be supported eventually
2960 				 */
2961 				btf_put(attach_btf);
2962 				err = -ENOTSUPP;
2963 				goto put_token;
2964 			}
2965 		}
2966 	} else if (attr->attach_btf_id) {
2967 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2968 		attach_btf = bpf_get_btf_vmlinux();
2969 		if (IS_ERR(attach_btf)) {
2970 			err = PTR_ERR(attach_btf);
2971 			goto put_token;
2972 		}
2973 		if (!attach_btf) {
2974 			err = -EINVAL;
2975 			goto put_token;
2976 		}
2977 		btf_get(attach_btf);
2978 	}
2979 
2980 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2981 				       attach_btf, attr->attach_btf_id,
2982 				       dst_prog)) {
2983 		if (dst_prog)
2984 			bpf_prog_put(dst_prog);
2985 		if (attach_btf)
2986 			btf_put(attach_btf);
2987 		err = -EINVAL;
2988 		goto put_token;
2989 	}
2990 
2991 	/* plain bpf_prog allocation */
2992 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2993 	if (!prog) {
2994 		if (dst_prog)
2995 			bpf_prog_put(dst_prog);
2996 		if (attach_btf)
2997 			btf_put(attach_btf);
2998 		err = -EINVAL;
2999 		goto put_token;
3000 	}
3001 
3002 	prog->expected_attach_type = attr->expected_attach_type;
3003 	prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
3004 	prog->aux->attach_btf = attach_btf;
3005 	prog->aux->attach_btf_id = attr->attach_btf_id;
3006 	prog->aux->dst_prog = dst_prog;
3007 	prog->aux->dev_bound = !!attr->prog_ifindex;
3008 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
3009 
3010 	/* move token into prog->aux, reuse taken refcnt */
3011 	prog->aux->token = token;
3012 	token = NULL;
3013 
3014 	prog->aux->user = get_current_user();
3015 	prog->len = attr->insn_cnt;
3016 
3017 	err = -EFAULT;
3018 	if (copy_from_bpfptr(prog->insns,
3019 			     make_bpfptr(attr->insns, uattr.is_kernel),
3020 			     bpf_prog_insn_size(prog)) != 0)
3021 		goto free_prog;
3022 	/* copy eBPF program license from user space */
3023 	if (strncpy_from_bpfptr(license,
3024 				make_bpfptr(attr->license, uattr.is_kernel),
3025 				sizeof(license) - 1) < 0)
3026 		goto free_prog;
3027 	license[sizeof(license) - 1] = 0;
3028 
3029 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
3030 	prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
3031 
3032 	if (attr->signature) {
3033 		err = bpf_prog_verify_signature(prog, attr, uattr.is_kernel);
3034 		if (err)
3035 			goto free_prog;
3036 	}
3037 
3038 	prog->orig_prog = NULL;
3039 	prog->jited = 0;
3040 
3041 	atomic64_set(&prog->aux->refcnt, 1);
3042 
3043 	if (bpf_prog_is_dev_bound(prog->aux)) {
3044 		err = bpf_prog_dev_bound_init(prog, attr);
3045 		if (err)
3046 			goto free_prog;
3047 	}
3048 
3049 	if (type == BPF_PROG_TYPE_EXT && dst_prog &&
3050 	    bpf_prog_is_dev_bound(dst_prog->aux)) {
3051 		err = bpf_prog_dev_bound_inherit(prog, dst_prog);
3052 		if (err)
3053 			goto free_prog;
3054 	}
3055 
3056 	/*
3057 	 * Bookkeeping for managing the program attachment chain.
3058 	 *
3059 	 * It might be tempting to set attach_tracing_prog flag at the attachment
3060 	 * time, but this will not prevent from loading bunch of tracing prog
3061 	 * first, then attach them one to another.
3062 	 *
3063 	 * The flag attach_tracing_prog is set for the whole program lifecycle, and
3064 	 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
3065 	 * programs cannot change attachment target.
3066 	 */
3067 	if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
3068 	    dst_prog->type == BPF_PROG_TYPE_TRACING) {
3069 		prog->aux->attach_tracing_prog = true;
3070 	}
3071 
3072 	/* find program type: socket_filter vs tracing_filter */
3073 	err = find_prog_type(type, prog);
3074 	if (err < 0)
3075 		goto free_prog;
3076 
3077 	prog->aux->load_time = ktime_get_boottime_ns();
3078 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
3079 			       sizeof(attr->prog_name));
3080 	if (err < 0)
3081 		goto free_prog;
3082 
3083 	err = security_bpf_prog_load(prog, attr, token, uattr.is_kernel);
3084 	if (err)
3085 		goto free_prog_sec;
3086 
3087 	/* run eBPF verifier */
3088 	err = bpf_check(&prog, attr, uattr, uattr_size);
3089 	if (err < 0)
3090 		goto free_used_maps;
3091 
3092 	prog = bpf_prog_select_runtime(prog, &err);
3093 	if (err < 0)
3094 		goto free_used_maps;
3095 
3096 	err = bpf_prog_mark_insn_arrays_ready(prog);
3097 	if (err < 0)
3098 		goto free_used_maps;
3099 
3100 	err = bpf_prog_alloc_id(prog);
3101 	if (err)
3102 		goto free_used_maps;
3103 
3104 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
3105 	 * effectively publicly exposed. However, retrieving via
3106 	 * bpf_prog_get_fd_by_id() will take another reference,
3107 	 * therefore it cannot be gone underneath us.
3108 	 *
3109 	 * Only for the time /after/ successful bpf_prog_new_fd()
3110 	 * and before returning to userspace, we might just hold
3111 	 * one reference and any parallel close on that fd could
3112 	 * rip everything out. Hence, below notifications must
3113 	 * happen before bpf_prog_new_fd().
3114 	 *
3115 	 * Also, any failure handling from this point onwards must
3116 	 * be using bpf_prog_put() given the program is exposed.
3117 	 */
3118 	bpf_prog_kallsyms_add(prog);
3119 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
3120 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
3121 
3122 	err = bpf_prog_new_fd(prog);
3123 	if (err < 0)
3124 		bpf_prog_put(prog);
3125 	return err;
3126 
3127 free_used_maps:
3128 	/* In case we have subprogs, we need to wait for a grace
3129 	 * period before we can tear down JIT memory since symbols
3130 	 * are already exposed under kallsyms.
3131 	 */
3132 	__bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
3133 	return err;
3134 
3135 free_prog_sec:
3136 	security_bpf_prog_free(prog);
3137 free_prog:
3138 	free_uid(prog->aux->user);
3139 	if (prog->aux->attach_btf)
3140 		btf_put(prog->aux->attach_btf);
3141 	bpf_prog_free(prog);
3142 put_token:
3143 	bpf_token_put(token);
3144 	return err;
3145 }
3146 
3147 #define BPF_OBJ_LAST_FIELD path_fd
3148 
bpf_obj_pin(const union bpf_attr * attr)3149 static int bpf_obj_pin(const union bpf_attr *attr)
3150 {
3151 	int path_fd;
3152 
3153 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
3154 		return -EINVAL;
3155 
3156 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3157 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3158 		return -EINVAL;
3159 
3160 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3161 	return bpf_obj_pin_user(attr->bpf_fd, path_fd,
3162 				u64_to_user_ptr(attr->pathname));
3163 }
3164 
bpf_obj_get(const union bpf_attr * attr)3165 static int bpf_obj_get(const union bpf_attr *attr)
3166 {
3167 	int path_fd;
3168 
3169 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
3170 	    attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
3171 		return -EINVAL;
3172 
3173 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
3174 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
3175 		return -EINVAL;
3176 
3177 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
3178 	return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
3179 				attr->file_flags);
3180 }
3181 
3182 /* bpf_link_init_sleepable() allows to specify whether BPF link itself has
3183  * "sleepable" semantics, which normally would mean that BPF link's attach
3184  * hook can dereference link or link's underlying program for some time after
3185  * detachment due to RCU Tasks Trace-based lifetime protection scheme.
3186  * BPF program itself can be non-sleepable, yet, because it's transitively
3187  * reachable through BPF link, its freeing has to be delayed until after RCU
3188  * Tasks Trace GP.
3189  */
bpf_link_init_sleepable(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type,bool sleepable)3190 void bpf_link_init_sleepable(struct bpf_link *link, enum bpf_link_type type,
3191 			     const struct bpf_link_ops *ops, struct bpf_prog *prog,
3192 			     enum bpf_attach_type attach_type, bool sleepable)
3193 {
3194 	WARN_ON(ops->dealloc && ops->dealloc_deferred);
3195 	atomic64_set(&link->refcnt, 1);
3196 	link->type = type;
3197 	link->sleepable = sleepable;
3198 	link->id = 0;
3199 	link->ops = ops;
3200 	link->prog = prog;
3201 	link->attach_type = attach_type;
3202 }
3203 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog,enum bpf_attach_type attach_type)3204 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
3205 		   const struct bpf_link_ops *ops, struct bpf_prog *prog,
3206 		   enum bpf_attach_type attach_type)
3207 {
3208 	bpf_link_init_sleepable(link, type, ops, prog, attach_type, false);
3209 }
3210 
bpf_link_free_id(int id)3211 static void bpf_link_free_id(int id)
3212 {
3213 	if (!id)
3214 		return;
3215 
3216 	spin_lock_bh(&link_idr_lock);
3217 	idr_remove(&link_idr, id);
3218 	spin_unlock_bh(&link_idr_lock);
3219 }
3220 
3221 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3222  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3223  * anon_inode's release() call. This helper marks bpf_link as
3224  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3225  * is not decremented, it's the responsibility of a calling code that failed
3226  * to complete bpf_link initialization.
3227  * This helper eventually calls link's dealloc callback, but does not call
3228  * link's release callback.
3229  */
bpf_link_cleanup(struct bpf_link_primer * primer)3230 void bpf_link_cleanup(struct bpf_link_primer *primer)
3231 {
3232 	primer->link->prog = NULL;
3233 	bpf_link_free_id(primer->id);
3234 	fput(primer->file);
3235 	put_unused_fd(primer->fd);
3236 }
3237 
bpf_link_inc(struct bpf_link * link)3238 void bpf_link_inc(struct bpf_link *link)
3239 {
3240 	atomic64_inc(&link->refcnt);
3241 }
3242 
bpf_link_dealloc(struct bpf_link * link)3243 static void bpf_link_dealloc(struct bpf_link *link)
3244 {
3245 	/* now that we know that bpf_link itself can't be reached, put underlying BPF program */
3246 	if (link->prog)
3247 		bpf_prog_put(link->prog);
3248 
3249 	/* free bpf_link and its containing memory */
3250 	if (link->ops->dealloc_deferred)
3251 		link->ops->dealloc_deferred(link);
3252 	else
3253 		link->ops->dealloc(link);
3254 }
3255 
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3256 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3257 {
3258 	struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3259 
3260 	bpf_link_dealloc(link);
3261 }
3262 
bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head * rcu)3263 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
3264 {
3265 	if (rcu_trace_implies_rcu_gp())
3266 		bpf_link_defer_dealloc_rcu_gp(rcu);
3267 	else
3268 		call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
3269 }
3270 
3271 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3272 static void bpf_link_free(struct bpf_link *link)
3273 {
3274 	const struct bpf_link_ops *ops = link->ops;
3275 
3276 	bpf_link_free_id(link->id);
3277 	/* detach BPF program, clean up used resources */
3278 	if (link->prog)
3279 		ops->release(link);
3280 	if (ops->dealloc_deferred) {
3281 		/* Schedule BPF link deallocation, which will only then
3282 		 * trigger putting BPF program refcount.
3283 		 * If underlying BPF program is sleepable or BPF link's target
3284 		 * attach hookpoint is sleepable or otherwise requires RCU GPs
3285 		 * to ensure link and its underlying BPF program is not
3286 		 * reachable anymore, we need to first wait for RCU tasks
3287 		 * trace sync, and then go through "classic" RCU grace period
3288 		 */
3289 		if (link->sleepable || (link->prog && link->prog->sleepable))
3290 			call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
3291 		else
3292 			call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3293 	} else if (ops->dealloc) {
3294 		bpf_link_dealloc(link);
3295 	}
3296 }
3297 
bpf_link_put_deferred(struct work_struct * work)3298 static void bpf_link_put_deferred(struct work_struct *work)
3299 {
3300 	struct bpf_link *link = container_of(work, struct bpf_link, work);
3301 
3302 	bpf_link_free(link);
3303 }
3304 
3305 /* bpf_link_put might be called from atomic context. It needs to be called
3306  * from sleepable context in order to acquire sleeping locks during the process.
3307  */
bpf_link_put(struct bpf_link * link)3308 void bpf_link_put(struct bpf_link *link)
3309 {
3310 	if (!atomic64_dec_and_test(&link->refcnt))
3311 		return;
3312 
3313 	INIT_WORK(&link->work, bpf_link_put_deferred);
3314 	schedule_work(&link->work);
3315 }
3316 EXPORT_SYMBOL(bpf_link_put);
3317 
bpf_link_put_direct(struct bpf_link * link)3318 static void bpf_link_put_direct(struct bpf_link *link)
3319 {
3320 	if (!atomic64_dec_and_test(&link->refcnt))
3321 		return;
3322 	bpf_link_free(link);
3323 }
3324 
bpf_link_release(struct inode * inode,struct file * filp)3325 static int bpf_link_release(struct inode *inode, struct file *filp)
3326 {
3327 	struct bpf_link *link = filp->private_data;
3328 
3329 	bpf_link_put_direct(link);
3330 	return 0;
3331 }
3332 
3333 #ifdef CONFIG_PROC_FS
3334 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3335 #define BPF_MAP_TYPE(_id, _ops)
3336 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3337 static const char *bpf_link_type_strs[] = {
3338 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3339 #include <linux/bpf_types.h>
3340 };
3341 #undef BPF_PROG_TYPE
3342 #undef BPF_MAP_TYPE
3343 #undef BPF_LINK_TYPE
3344 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3345 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3346 {
3347 	const struct bpf_link *link = filp->private_data;
3348 	const struct bpf_prog *prog = link->prog;
3349 	enum bpf_link_type type = link->type;
3350 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3351 
3352 	if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
3353 		if (link->type == BPF_LINK_TYPE_KPROBE_MULTI)
3354 			seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_KPROBE_MULTI_RETURN ?
3355 				   "kretprobe_multi" : "kprobe_multi");
3356 		else if (link->type == BPF_LINK_TYPE_UPROBE_MULTI)
3357 			seq_printf(m, "link_type:\t%s\n", link->flags == BPF_F_UPROBE_MULTI_RETURN ?
3358 				   "uretprobe_multi" : "uprobe_multi");
3359 		else
3360 			seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
3361 	} else {
3362 		WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
3363 		seq_printf(m, "link_type:\t<%u>\n", type);
3364 	}
3365 	seq_printf(m, "link_id:\t%u\n", link->id);
3366 
3367 	if (prog) {
3368 		bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3369 		seq_printf(m,
3370 			   "prog_tag:\t%s\n"
3371 			   "prog_id:\t%u\n",
3372 			   prog_tag,
3373 			   prog->aux->id);
3374 	}
3375 	if (link->ops->show_fdinfo)
3376 		link->ops->show_fdinfo(link, m);
3377 }
3378 #endif
3379 
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3380 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3381 {
3382 	struct bpf_link *link = file->private_data;
3383 
3384 	return link->ops->poll(file, pts);
3385 }
3386 
3387 static const struct file_operations bpf_link_fops = {
3388 #ifdef CONFIG_PROC_FS
3389 	.show_fdinfo	= bpf_link_show_fdinfo,
3390 #endif
3391 	.release	= bpf_link_release,
3392 	.read		= bpf_dummy_read,
3393 	.write		= bpf_dummy_write,
3394 };
3395 
3396 static const struct file_operations bpf_link_fops_poll = {
3397 #ifdef CONFIG_PROC_FS
3398 	.show_fdinfo	= bpf_link_show_fdinfo,
3399 #endif
3400 	.release	= bpf_link_release,
3401 	.read		= bpf_dummy_read,
3402 	.write		= bpf_dummy_write,
3403 	.poll		= bpf_link_poll,
3404 };
3405 
bpf_link_alloc_id(struct bpf_link * link)3406 static int bpf_link_alloc_id(struct bpf_link *link)
3407 {
3408 	int id;
3409 
3410 	idr_preload(GFP_KERNEL);
3411 	spin_lock_bh(&link_idr_lock);
3412 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3413 	spin_unlock_bh(&link_idr_lock);
3414 	idr_preload_end();
3415 
3416 	return id;
3417 }
3418 
3419 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3420  * reserving unused FD and allocating ID from link_idr. This is to be paired
3421  * with bpf_link_settle() to install FD and ID and expose bpf_link to
3422  * user-space, if bpf_link is successfully attached. If not, bpf_link and
3423  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3424  * transient state is passed around in struct bpf_link_primer.
3425  * This is preferred way to create and initialize bpf_link, especially when
3426  * there are complicated and expensive operations in between creating bpf_link
3427  * itself and attaching it to BPF hook. By using bpf_link_prime() and
3428  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3429  * expensive (and potentially failing) roll back operations in a rare case
3430  * that file, FD, or ID can't be allocated.
3431  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3432 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3433 {
3434 	struct file *file;
3435 	int fd, id;
3436 
3437 	fd = get_unused_fd_flags(O_CLOEXEC);
3438 	if (fd < 0)
3439 		return fd;
3440 
3441 
3442 	id = bpf_link_alloc_id(link);
3443 	if (id < 0) {
3444 		put_unused_fd(fd);
3445 		return id;
3446 	}
3447 
3448 	file = anon_inode_getfile("bpf_link",
3449 				  link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3450 				  link, O_CLOEXEC);
3451 	if (IS_ERR(file)) {
3452 		bpf_link_free_id(id);
3453 		put_unused_fd(fd);
3454 		return PTR_ERR(file);
3455 	}
3456 
3457 	primer->link = link;
3458 	primer->file = file;
3459 	primer->fd = fd;
3460 	primer->id = id;
3461 	return 0;
3462 }
3463 
bpf_link_settle(struct bpf_link_primer * primer)3464 int bpf_link_settle(struct bpf_link_primer *primer)
3465 {
3466 	/* make bpf_link fetchable by ID */
3467 	spin_lock_bh(&link_idr_lock);
3468 	primer->link->id = primer->id;
3469 	spin_unlock_bh(&link_idr_lock);
3470 	/* make bpf_link fetchable by FD */
3471 	fd_install(primer->fd, primer->file);
3472 	/* pass through installed FD */
3473 	return primer->fd;
3474 }
3475 
bpf_link_new_fd(struct bpf_link * link)3476 int bpf_link_new_fd(struct bpf_link *link)
3477 {
3478 	return anon_inode_getfd("bpf-link",
3479 				link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3480 				link, O_CLOEXEC);
3481 }
3482 
bpf_link_get_from_fd(u32 ufd)3483 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3484 {
3485 	CLASS(fd, f)(ufd);
3486 	struct bpf_link *link;
3487 
3488 	if (fd_empty(f))
3489 		return ERR_PTR(-EBADF);
3490 	if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
3491 		return ERR_PTR(-EINVAL);
3492 
3493 	link = fd_file(f)->private_data;
3494 	bpf_link_inc(link);
3495 	return link;
3496 }
3497 EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL");
3498 
bpf_tracing_link_release(struct bpf_link * link)3499 static void bpf_tracing_link_release(struct bpf_link *link)
3500 {
3501 	struct bpf_tracing_link *tr_link =
3502 		container_of(link, struct bpf_tracing_link, link.link);
3503 
3504 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3505 						tr_link->trampoline,
3506 						tr_link->tgt_prog));
3507 
3508 	bpf_trampoline_put(tr_link->trampoline);
3509 
3510 	/* tgt_prog is NULL if target is a kernel function */
3511 	if (tr_link->tgt_prog)
3512 		bpf_prog_put(tr_link->tgt_prog);
3513 }
3514 
bpf_tracing_link_dealloc(struct bpf_link * link)3515 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3516 {
3517 	struct bpf_tracing_link *tr_link =
3518 		container_of(link, struct bpf_tracing_link, link.link);
3519 
3520 	kfree(tr_link);
3521 }
3522 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3523 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3524 					 struct seq_file *seq)
3525 {
3526 	struct bpf_tracing_link *tr_link =
3527 		container_of(link, struct bpf_tracing_link, link.link);
3528 	u32 target_btf_id, target_obj_id;
3529 
3530 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3531 				  &target_obj_id, &target_btf_id);
3532 	seq_printf(seq,
3533 		   "attach_type:\t%d\n"
3534 		   "target_obj_id:\t%u\n"
3535 		   "target_btf_id:\t%u\n"
3536 		   "cookie:\t%llu\n",
3537 		   link->attach_type,
3538 		   target_obj_id,
3539 		   target_btf_id,
3540 		   tr_link->link.cookie);
3541 }
3542 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3543 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3544 					   struct bpf_link_info *info)
3545 {
3546 	struct bpf_tracing_link *tr_link =
3547 		container_of(link, struct bpf_tracing_link, link.link);
3548 
3549 	info->tracing.attach_type = link->attach_type;
3550 	info->tracing.cookie = tr_link->link.cookie;
3551 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3552 				  &info->tracing.target_obj_id,
3553 				  &info->tracing.target_btf_id);
3554 
3555 	return 0;
3556 }
3557 
3558 static const struct bpf_link_ops bpf_tracing_link_lops = {
3559 	.release = bpf_tracing_link_release,
3560 	.dealloc = bpf_tracing_link_dealloc,
3561 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3562 	.fill_link_info = bpf_tracing_link_fill_link_info,
3563 };
3564 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie,enum bpf_attach_type attach_type)3565 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3566 				   int tgt_prog_fd,
3567 				   u32 btf_id,
3568 				   u64 bpf_cookie,
3569 				   enum bpf_attach_type attach_type)
3570 {
3571 	struct bpf_link_primer link_primer;
3572 	struct bpf_prog *tgt_prog = NULL;
3573 	struct bpf_trampoline *tr = NULL;
3574 	struct bpf_tracing_link *link;
3575 	u64 key = 0;
3576 	int err;
3577 
3578 	switch (prog->type) {
3579 	case BPF_PROG_TYPE_TRACING:
3580 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3581 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3582 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3583 			err = -EINVAL;
3584 			goto out_put_prog;
3585 		}
3586 		break;
3587 	case BPF_PROG_TYPE_EXT:
3588 		if (prog->expected_attach_type != 0) {
3589 			err = -EINVAL;
3590 			goto out_put_prog;
3591 		}
3592 		break;
3593 	case BPF_PROG_TYPE_LSM:
3594 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3595 			err = -EINVAL;
3596 			goto out_put_prog;
3597 		}
3598 		break;
3599 	default:
3600 		err = -EINVAL;
3601 		goto out_put_prog;
3602 	}
3603 
3604 	if (!!tgt_prog_fd != !!btf_id) {
3605 		err = -EINVAL;
3606 		goto out_put_prog;
3607 	}
3608 
3609 	if (tgt_prog_fd) {
3610 		/*
3611 		 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3612 		 * part would be changed to implement the same for
3613 		 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3614 		 * attach_tracing_prog flag is set.
3615 		 */
3616 		if (prog->type != BPF_PROG_TYPE_EXT) {
3617 			err = -EINVAL;
3618 			goto out_put_prog;
3619 		}
3620 
3621 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3622 		if (IS_ERR(tgt_prog)) {
3623 			err = PTR_ERR(tgt_prog);
3624 			tgt_prog = NULL;
3625 			goto out_put_prog;
3626 		}
3627 
3628 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3629 	}
3630 
3631 	link = kzalloc(sizeof(*link), GFP_USER);
3632 	if (!link) {
3633 		err = -ENOMEM;
3634 		goto out_put_prog;
3635 	}
3636 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3637 		      &bpf_tracing_link_lops, prog, attach_type);
3638 
3639 	link->link.cookie = bpf_cookie;
3640 
3641 	mutex_lock(&prog->aux->dst_mutex);
3642 
3643 	/* There are a few possible cases here:
3644 	 *
3645 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3646 	 *   and not yet attached to anything, so we can use the values stored
3647 	 *   in prog->aux
3648 	 *
3649 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3650 	 *   attached to a target and its initial target was cleared (below)
3651 	 *
3652 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3653 	 *   target_btf_id using the link_create API.
3654 	 *
3655 	 * - if tgt_prog == NULL when this function was called using the old
3656 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3657 	 *
3658 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3659 	 *   was detached and is going for re-attachment.
3660 	 *
3661 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3662 	 *   are NULL, then program was already attached and user did not provide
3663 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3664 	 */
3665 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3666 		/*
3667 		 * Allow re-attach for TRACING and LSM programs. If it's
3668 		 * currently linked, bpf_trampoline_link_prog will fail.
3669 		 * EXT programs need to specify tgt_prog_fd, so they
3670 		 * re-attach in separate code path.
3671 		 */
3672 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3673 		    prog->type != BPF_PROG_TYPE_LSM) {
3674 			err = -EINVAL;
3675 			goto out_unlock;
3676 		}
3677 		/* We can allow re-attach only if we have valid attach_btf. */
3678 		if (!prog->aux->attach_btf) {
3679 			err = -EINVAL;
3680 			goto out_unlock;
3681 		}
3682 		btf_id = prog->aux->attach_btf_id;
3683 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3684 	}
3685 
3686 	if (!prog->aux->dst_trampoline ||
3687 	    (key && key != prog->aux->dst_trampoline->key)) {
3688 		/* If there is no saved target, or the specified target is
3689 		 * different from the destination specified at load time, we
3690 		 * need a new trampoline and a check for compatibility
3691 		 */
3692 		struct bpf_attach_target_info tgt_info = {};
3693 
3694 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3695 					      &tgt_info);
3696 		if (err)
3697 			goto out_unlock;
3698 
3699 		if (tgt_info.tgt_mod) {
3700 			module_put(prog->aux->mod);
3701 			prog->aux->mod = tgt_info.tgt_mod;
3702 		}
3703 
3704 		tr = bpf_trampoline_get(key, &tgt_info);
3705 		if (!tr) {
3706 			err = -ENOMEM;
3707 			goto out_unlock;
3708 		}
3709 	} else {
3710 		/* The caller didn't specify a target, or the target was the
3711 		 * same as the destination supplied during program load. This
3712 		 * means we can reuse the trampoline and reference from program
3713 		 * load time, and there is no need to allocate a new one. This
3714 		 * can only happen once for any program, as the saved values in
3715 		 * prog->aux are cleared below.
3716 		 */
3717 		tr = prog->aux->dst_trampoline;
3718 		tgt_prog = prog->aux->dst_prog;
3719 	}
3720 
3721 	err = bpf_link_prime(&link->link.link, &link_primer);
3722 	if (err)
3723 		goto out_unlock;
3724 
3725 	err = bpf_trampoline_link_prog(&link->link, tr, tgt_prog);
3726 	if (err) {
3727 		bpf_link_cleanup(&link_primer);
3728 		link = NULL;
3729 		goto out_unlock;
3730 	}
3731 
3732 	link->tgt_prog = tgt_prog;
3733 	link->trampoline = tr;
3734 
3735 	/* Always clear the trampoline and target prog from prog->aux to make
3736 	 * sure the original attach destination is not kept alive after a
3737 	 * program is (re-)attached to another target.
3738 	 */
3739 	if (prog->aux->dst_prog &&
3740 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3741 		/* got extra prog ref from syscall, or attaching to different prog */
3742 		bpf_prog_put(prog->aux->dst_prog);
3743 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3744 		/* we allocated a new trampoline, so free the old one */
3745 		bpf_trampoline_put(prog->aux->dst_trampoline);
3746 
3747 	prog->aux->dst_prog = NULL;
3748 	prog->aux->dst_trampoline = NULL;
3749 	mutex_unlock(&prog->aux->dst_mutex);
3750 
3751 	return bpf_link_settle(&link_primer);
3752 out_unlock:
3753 	if (tr && tr != prog->aux->dst_trampoline)
3754 		bpf_trampoline_put(tr);
3755 	mutex_unlock(&prog->aux->dst_mutex);
3756 	kfree(link);
3757 out_put_prog:
3758 	if (tgt_prog_fd && tgt_prog)
3759 		bpf_prog_put(tgt_prog);
3760 	return err;
3761 }
3762 
bpf_raw_tp_link_release(struct bpf_link * link)3763 static void bpf_raw_tp_link_release(struct bpf_link *link)
3764 {
3765 	struct bpf_raw_tp_link *raw_tp =
3766 		container_of(link, struct bpf_raw_tp_link, link);
3767 
3768 	bpf_probe_unregister(raw_tp->btp, raw_tp);
3769 	bpf_put_raw_tracepoint(raw_tp->btp);
3770 }
3771 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3772 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3773 {
3774 	struct bpf_raw_tp_link *raw_tp =
3775 		container_of(link, struct bpf_raw_tp_link, link);
3776 
3777 	kfree(raw_tp);
3778 }
3779 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3780 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3781 					struct seq_file *seq)
3782 {
3783 	struct bpf_raw_tp_link *raw_tp_link =
3784 		container_of(link, struct bpf_raw_tp_link, link);
3785 
3786 	seq_printf(seq,
3787 		   "tp_name:\t%s\n"
3788 		   "cookie:\t%llu\n",
3789 		   raw_tp_link->btp->tp->name,
3790 		   raw_tp_link->cookie);
3791 }
3792 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3793 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3794 			    u32 len)
3795 {
3796 	if (ulen >= len + 1) {
3797 		if (copy_to_user(ubuf, buf, len + 1))
3798 			return -EFAULT;
3799 	} else {
3800 		char zero = '\0';
3801 
3802 		if (copy_to_user(ubuf, buf, ulen - 1))
3803 			return -EFAULT;
3804 		if (put_user(zero, ubuf + ulen - 1))
3805 			return -EFAULT;
3806 		return -ENOSPC;
3807 	}
3808 
3809 	return 0;
3810 }
3811 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3812 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3813 					  struct bpf_link_info *info)
3814 {
3815 	struct bpf_raw_tp_link *raw_tp_link =
3816 		container_of(link, struct bpf_raw_tp_link, link);
3817 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3818 	const char *tp_name = raw_tp_link->btp->tp->name;
3819 	u32 ulen = info->raw_tracepoint.tp_name_len;
3820 	size_t tp_len = strlen(tp_name);
3821 
3822 	if (!ulen ^ !ubuf)
3823 		return -EINVAL;
3824 
3825 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3826 	info->raw_tracepoint.cookie = raw_tp_link->cookie;
3827 
3828 	if (!ubuf)
3829 		return 0;
3830 
3831 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3832 }
3833 
3834 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3835 	.release = bpf_raw_tp_link_release,
3836 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3837 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3838 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3839 };
3840 
3841 #ifdef CONFIG_PERF_EVENTS
3842 struct bpf_perf_link {
3843 	struct bpf_link link;
3844 	struct file *perf_file;
3845 };
3846 
bpf_perf_link_release(struct bpf_link * link)3847 static void bpf_perf_link_release(struct bpf_link *link)
3848 {
3849 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3850 	struct perf_event *event = perf_link->perf_file->private_data;
3851 
3852 	perf_event_free_bpf_prog(event);
3853 	fput(perf_link->perf_file);
3854 }
3855 
bpf_perf_link_dealloc(struct bpf_link * link)3856 static void bpf_perf_link_dealloc(struct bpf_link *link)
3857 {
3858 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3859 
3860 	kfree(perf_link);
3861 }
3862 
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)3863 static int bpf_perf_link_fill_common(const struct perf_event *event,
3864 				     char __user *uname, u32 *ulenp,
3865 				     u64 *probe_offset, u64 *probe_addr,
3866 				     u32 *fd_type, unsigned long *missed)
3867 {
3868 	const char *buf;
3869 	u32 prog_id, ulen;
3870 	size_t len;
3871 	int err;
3872 
3873 	ulen = *ulenp;
3874 	if (!ulen ^ !uname)
3875 		return -EINVAL;
3876 
3877 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3878 				      probe_offset, probe_addr, missed);
3879 	if (err)
3880 		return err;
3881 
3882 	if (buf) {
3883 		len = strlen(buf);
3884 		*ulenp = len + 1;
3885 	} else {
3886 		*ulenp = 1;
3887 	}
3888 	if (!uname)
3889 		return 0;
3890 
3891 	if (buf) {
3892 		err = bpf_copy_to_user(uname, buf, ulen, len);
3893 		if (err)
3894 			return err;
3895 	} else {
3896 		char zero = '\0';
3897 
3898 		if (put_user(zero, uname))
3899 			return -EFAULT;
3900 	}
3901 	return 0;
3902 }
3903 
3904 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3905 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3906 				     struct bpf_link_info *info)
3907 {
3908 	unsigned long missed;
3909 	char __user *uname;
3910 	u64 addr, offset;
3911 	u32 ulen, type;
3912 	int err;
3913 
3914 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3915 	ulen = info->perf_event.kprobe.name_len;
3916 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
3917 					&type, &missed);
3918 	if (err)
3919 		return err;
3920 	if (type == BPF_FD_TYPE_KRETPROBE)
3921 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3922 	else
3923 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3924 	info->perf_event.kprobe.name_len = ulen;
3925 	info->perf_event.kprobe.offset = offset;
3926 	info->perf_event.kprobe.missed = missed;
3927 	if (!kallsyms_show_value(current_cred()))
3928 		addr = 0;
3929 	info->perf_event.kprobe.addr = addr;
3930 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3931 	return 0;
3932 }
3933 
bpf_perf_link_fdinfo_kprobe(const struct perf_event * event,struct seq_file * seq)3934 static void bpf_perf_link_fdinfo_kprobe(const struct perf_event *event,
3935 					struct seq_file *seq)
3936 {
3937 	const char *name;
3938 	int err;
3939 	u32 prog_id, type;
3940 	u64 offset, addr;
3941 	unsigned long missed;
3942 
3943 	err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
3944 				      &offset, &addr, &missed);
3945 	if (err)
3946 		return;
3947 
3948 	seq_printf(seq,
3949 		   "name:\t%s\n"
3950 		   "offset:\t%#llx\n"
3951 		   "missed:\t%lu\n"
3952 		   "addr:\t%#llx\n"
3953 		   "event_type:\t%s\n"
3954 		   "cookie:\t%llu\n",
3955 		   name, offset, missed, addr,
3956 		   type == BPF_FD_TYPE_KRETPROBE ?  "kretprobe" : "kprobe",
3957 		   event->bpf_cookie);
3958 }
3959 #endif
3960 
3961 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3962 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3963 				     struct bpf_link_info *info)
3964 {
3965 	u64 ref_ctr_offset, offset;
3966 	char __user *uname;
3967 	u32 ulen, type;
3968 	int err;
3969 
3970 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3971 	ulen = info->perf_event.uprobe.name_len;
3972 	err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &ref_ctr_offset,
3973 					&type, NULL);
3974 	if (err)
3975 		return err;
3976 
3977 	if (type == BPF_FD_TYPE_URETPROBE)
3978 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3979 	else
3980 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3981 	info->perf_event.uprobe.name_len = ulen;
3982 	info->perf_event.uprobe.offset = offset;
3983 	info->perf_event.uprobe.cookie = event->bpf_cookie;
3984 	info->perf_event.uprobe.ref_ctr_offset = ref_ctr_offset;
3985 	return 0;
3986 }
3987 
bpf_perf_link_fdinfo_uprobe(const struct perf_event * event,struct seq_file * seq)3988 static void bpf_perf_link_fdinfo_uprobe(const struct perf_event *event,
3989 					struct seq_file *seq)
3990 {
3991 	const char *name;
3992 	int err;
3993 	u32 prog_id, type;
3994 	u64 offset, ref_ctr_offset;
3995 	unsigned long missed;
3996 
3997 	err = bpf_get_perf_event_info(event, &prog_id, &type, &name,
3998 				      &offset, &ref_ctr_offset, &missed);
3999 	if (err)
4000 		return;
4001 
4002 	seq_printf(seq,
4003 		   "name:\t%s\n"
4004 		   "offset:\t%#llx\n"
4005 		   "ref_ctr_offset:\t%#llx\n"
4006 		   "event_type:\t%s\n"
4007 		   "cookie:\t%llu\n",
4008 		   name, offset, ref_ctr_offset,
4009 		   type == BPF_FD_TYPE_URETPROBE ?  "uretprobe" : "uprobe",
4010 		   event->bpf_cookie);
4011 }
4012 #endif
4013 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)4014 static int bpf_perf_link_fill_probe(const struct perf_event *event,
4015 				    struct bpf_link_info *info)
4016 {
4017 #ifdef CONFIG_KPROBE_EVENTS
4018 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4019 		return bpf_perf_link_fill_kprobe(event, info);
4020 #endif
4021 #ifdef CONFIG_UPROBE_EVENTS
4022 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4023 		return bpf_perf_link_fill_uprobe(event, info);
4024 #endif
4025 	return -EOPNOTSUPP;
4026 }
4027 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)4028 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
4029 					 struct bpf_link_info *info)
4030 {
4031 	char __user *uname;
4032 	u32 ulen;
4033 	int err;
4034 
4035 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
4036 	ulen = info->perf_event.tracepoint.name_len;
4037 	err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
4038 	if (err)
4039 		return err;
4040 
4041 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
4042 	info->perf_event.tracepoint.name_len = ulen;
4043 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
4044 	return 0;
4045 }
4046 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)4047 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
4048 					 struct bpf_link_info *info)
4049 {
4050 	info->perf_event.event.type = event->attr.type;
4051 	info->perf_event.event.config = event->attr.config;
4052 	info->perf_event.event.cookie = event->bpf_cookie;
4053 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
4054 	return 0;
4055 }
4056 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)4057 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
4058 					struct bpf_link_info *info)
4059 {
4060 	struct bpf_perf_link *perf_link;
4061 	const struct perf_event *event;
4062 
4063 	perf_link = container_of(link, struct bpf_perf_link, link);
4064 	event = perf_get_event(perf_link->perf_file);
4065 	if (IS_ERR(event))
4066 		return PTR_ERR(event);
4067 
4068 	switch (event->prog->type) {
4069 	case BPF_PROG_TYPE_PERF_EVENT:
4070 		return bpf_perf_link_fill_perf_event(event, info);
4071 	case BPF_PROG_TYPE_TRACEPOINT:
4072 		return bpf_perf_link_fill_tracepoint(event, info);
4073 	case BPF_PROG_TYPE_KPROBE:
4074 		return bpf_perf_link_fill_probe(event, info);
4075 	default:
4076 		return -EOPNOTSUPP;
4077 	}
4078 }
4079 
bpf_perf_event_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4080 static void bpf_perf_event_link_show_fdinfo(const struct perf_event *event,
4081 					    struct seq_file *seq)
4082 {
4083 	seq_printf(seq,
4084 		   "type:\t%u\n"
4085 		   "config:\t%llu\n"
4086 		   "event_type:\t%s\n"
4087 		   "cookie:\t%llu\n",
4088 		   event->attr.type, event->attr.config,
4089 		   "event", event->bpf_cookie);
4090 }
4091 
bpf_tracepoint_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4092 static void bpf_tracepoint_link_show_fdinfo(const struct perf_event *event,
4093 					    struct seq_file *seq)
4094 {
4095 	int err;
4096 	const char *name;
4097 	u32 prog_id;
4098 
4099 	err = bpf_get_perf_event_info(event, &prog_id, NULL, &name, NULL,
4100 				      NULL, NULL);
4101 	if (err)
4102 		return;
4103 
4104 	seq_printf(seq,
4105 		   "tp_name:\t%s\n"
4106 		   "event_type:\t%s\n"
4107 		   "cookie:\t%llu\n",
4108 		   name, "tracepoint", event->bpf_cookie);
4109 }
4110 
bpf_probe_link_show_fdinfo(const struct perf_event * event,struct seq_file * seq)4111 static void bpf_probe_link_show_fdinfo(const struct perf_event *event,
4112 				       struct seq_file *seq)
4113 {
4114 #ifdef CONFIG_KPROBE_EVENTS
4115 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
4116 		return bpf_perf_link_fdinfo_kprobe(event, seq);
4117 #endif
4118 
4119 #ifdef CONFIG_UPROBE_EVENTS
4120 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
4121 		return bpf_perf_link_fdinfo_uprobe(event, seq);
4122 #endif
4123 }
4124 
bpf_perf_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)4125 static void bpf_perf_link_show_fdinfo(const struct bpf_link *link,
4126 				      struct seq_file *seq)
4127 {
4128 	struct bpf_perf_link *perf_link;
4129 	const struct perf_event *event;
4130 
4131 	perf_link = container_of(link, struct bpf_perf_link, link);
4132 	event = perf_get_event(perf_link->perf_file);
4133 	if (IS_ERR(event))
4134 		return;
4135 
4136 	switch (event->prog->type) {
4137 	case BPF_PROG_TYPE_PERF_EVENT:
4138 		return bpf_perf_event_link_show_fdinfo(event, seq);
4139 	case BPF_PROG_TYPE_TRACEPOINT:
4140 		return bpf_tracepoint_link_show_fdinfo(event, seq);
4141 	case BPF_PROG_TYPE_KPROBE:
4142 		return bpf_probe_link_show_fdinfo(event, seq);
4143 	default:
4144 		return;
4145 	}
4146 }
4147 
4148 static const struct bpf_link_ops bpf_perf_link_lops = {
4149 	.release = bpf_perf_link_release,
4150 	.dealloc = bpf_perf_link_dealloc,
4151 	.fill_link_info = bpf_perf_link_fill_link_info,
4152 	.show_fdinfo = bpf_perf_link_show_fdinfo,
4153 };
4154 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4155 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4156 {
4157 	struct bpf_link_primer link_primer;
4158 	struct bpf_perf_link *link;
4159 	struct perf_event *event;
4160 	struct file *perf_file;
4161 	int err;
4162 
4163 	if (attr->link_create.flags)
4164 		return -EINVAL;
4165 
4166 	perf_file = perf_event_get(attr->link_create.target_fd);
4167 	if (IS_ERR(perf_file))
4168 		return PTR_ERR(perf_file);
4169 
4170 	link = kzalloc(sizeof(*link), GFP_USER);
4171 	if (!link) {
4172 		err = -ENOMEM;
4173 		goto out_put_file;
4174 	}
4175 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog,
4176 		      attr->link_create.attach_type);
4177 	link->perf_file = perf_file;
4178 
4179 	err = bpf_link_prime(&link->link, &link_primer);
4180 	if (err) {
4181 		kfree(link);
4182 		goto out_put_file;
4183 	}
4184 
4185 	event = perf_file->private_data;
4186 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
4187 	if (err) {
4188 		bpf_link_cleanup(&link_primer);
4189 		goto out_put_file;
4190 	}
4191 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
4192 	bpf_prog_inc(prog);
4193 
4194 	return bpf_link_settle(&link_primer);
4195 
4196 out_put_file:
4197 	fput(perf_file);
4198 	return err;
4199 }
4200 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)4201 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
4202 {
4203 	return -EOPNOTSUPP;
4204 }
4205 #endif /* CONFIG_PERF_EVENTS */
4206 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie,enum bpf_attach_type attach_type)4207 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
4208 				  const char __user *user_tp_name, u64 cookie,
4209 				  enum bpf_attach_type attach_type)
4210 {
4211 	struct bpf_link_primer link_primer;
4212 	struct bpf_raw_tp_link *link;
4213 	struct bpf_raw_event_map *btp;
4214 	const char *tp_name;
4215 	char buf[128];
4216 	int err;
4217 
4218 	switch (prog->type) {
4219 	case BPF_PROG_TYPE_TRACING:
4220 	case BPF_PROG_TYPE_EXT:
4221 	case BPF_PROG_TYPE_LSM:
4222 		if (user_tp_name)
4223 			/* The attach point for this category of programs
4224 			 * should be specified via btf_id during program load.
4225 			 */
4226 			return -EINVAL;
4227 		if (prog->type == BPF_PROG_TYPE_TRACING &&
4228 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
4229 			tp_name = prog->aux->attach_func_name;
4230 			break;
4231 		}
4232 		return bpf_tracing_prog_attach(prog, 0, 0, 0, attach_type);
4233 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
4234 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
4235 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
4236 			return -EFAULT;
4237 		buf[sizeof(buf) - 1] = 0;
4238 		tp_name = buf;
4239 		break;
4240 	default:
4241 		return -EINVAL;
4242 	}
4243 
4244 	btp = bpf_get_raw_tracepoint(tp_name);
4245 	if (!btp)
4246 		return -ENOENT;
4247 
4248 	link = kzalloc(sizeof(*link), GFP_USER);
4249 	if (!link) {
4250 		err = -ENOMEM;
4251 		goto out_put_btp;
4252 	}
4253 	bpf_link_init_sleepable(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
4254 				&bpf_raw_tp_link_lops, prog, attach_type,
4255 				tracepoint_is_faultable(btp->tp));
4256 	link->btp = btp;
4257 	link->cookie = cookie;
4258 
4259 	err = bpf_link_prime(&link->link, &link_primer);
4260 	if (err) {
4261 		kfree(link);
4262 		goto out_put_btp;
4263 	}
4264 
4265 	err = bpf_probe_register(link->btp, link);
4266 	if (err) {
4267 		bpf_link_cleanup(&link_primer);
4268 		goto out_put_btp;
4269 	}
4270 
4271 	return bpf_link_settle(&link_primer);
4272 
4273 out_put_btp:
4274 	bpf_put_raw_tracepoint(btp);
4275 	return err;
4276 }
4277 
4278 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
4279 
bpf_raw_tracepoint_open(const union bpf_attr * attr)4280 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
4281 {
4282 	struct bpf_prog *prog;
4283 	void __user *tp_name;
4284 	__u64 cookie;
4285 	int fd;
4286 
4287 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
4288 		return -EINVAL;
4289 
4290 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
4291 	if (IS_ERR(prog))
4292 		return PTR_ERR(prog);
4293 
4294 	tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
4295 	cookie = attr->raw_tracepoint.cookie;
4296 	fd = bpf_raw_tp_link_attach(prog, tp_name, cookie, prog->expected_attach_type);
4297 	if (fd < 0)
4298 		bpf_prog_put(prog);
4299 	return fd;
4300 }
4301 
4302 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)4303 attach_type_to_prog_type(enum bpf_attach_type attach_type)
4304 {
4305 	switch (attach_type) {
4306 	case BPF_CGROUP_INET_INGRESS:
4307 	case BPF_CGROUP_INET_EGRESS:
4308 		return BPF_PROG_TYPE_CGROUP_SKB;
4309 	case BPF_CGROUP_INET_SOCK_CREATE:
4310 	case BPF_CGROUP_INET_SOCK_RELEASE:
4311 	case BPF_CGROUP_INET4_POST_BIND:
4312 	case BPF_CGROUP_INET6_POST_BIND:
4313 		return BPF_PROG_TYPE_CGROUP_SOCK;
4314 	case BPF_CGROUP_INET4_BIND:
4315 	case BPF_CGROUP_INET6_BIND:
4316 	case BPF_CGROUP_INET4_CONNECT:
4317 	case BPF_CGROUP_INET6_CONNECT:
4318 	case BPF_CGROUP_UNIX_CONNECT:
4319 	case BPF_CGROUP_INET4_GETPEERNAME:
4320 	case BPF_CGROUP_INET6_GETPEERNAME:
4321 	case BPF_CGROUP_UNIX_GETPEERNAME:
4322 	case BPF_CGROUP_INET4_GETSOCKNAME:
4323 	case BPF_CGROUP_INET6_GETSOCKNAME:
4324 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4325 	case BPF_CGROUP_UDP4_SENDMSG:
4326 	case BPF_CGROUP_UDP6_SENDMSG:
4327 	case BPF_CGROUP_UNIX_SENDMSG:
4328 	case BPF_CGROUP_UDP4_RECVMSG:
4329 	case BPF_CGROUP_UDP6_RECVMSG:
4330 	case BPF_CGROUP_UNIX_RECVMSG:
4331 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
4332 	case BPF_CGROUP_SOCK_OPS:
4333 		return BPF_PROG_TYPE_SOCK_OPS;
4334 	case BPF_CGROUP_DEVICE:
4335 		return BPF_PROG_TYPE_CGROUP_DEVICE;
4336 	case BPF_SK_MSG_VERDICT:
4337 		return BPF_PROG_TYPE_SK_MSG;
4338 	case BPF_SK_SKB_STREAM_PARSER:
4339 	case BPF_SK_SKB_STREAM_VERDICT:
4340 	case BPF_SK_SKB_VERDICT:
4341 		return BPF_PROG_TYPE_SK_SKB;
4342 	case BPF_LIRC_MODE2:
4343 		return BPF_PROG_TYPE_LIRC_MODE2;
4344 	case BPF_FLOW_DISSECTOR:
4345 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
4346 	case BPF_CGROUP_SYSCTL:
4347 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
4348 	case BPF_CGROUP_GETSOCKOPT:
4349 	case BPF_CGROUP_SETSOCKOPT:
4350 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
4351 	case BPF_TRACE_ITER:
4352 	case BPF_TRACE_RAW_TP:
4353 	case BPF_TRACE_FENTRY:
4354 	case BPF_TRACE_FEXIT:
4355 	case BPF_MODIFY_RETURN:
4356 		return BPF_PROG_TYPE_TRACING;
4357 	case BPF_LSM_MAC:
4358 		return BPF_PROG_TYPE_LSM;
4359 	case BPF_SK_LOOKUP:
4360 		return BPF_PROG_TYPE_SK_LOOKUP;
4361 	case BPF_XDP:
4362 		return BPF_PROG_TYPE_XDP;
4363 	case BPF_LSM_CGROUP:
4364 		return BPF_PROG_TYPE_LSM;
4365 	case BPF_TCX_INGRESS:
4366 	case BPF_TCX_EGRESS:
4367 	case BPF_NETKIT_PRIMARY:
4368 	case BPF_NETKIT_PEER:
4369 		return BPF_PROG_TYPE_SCHED_CLS;
4370 	default:
4371 		return BPF_PROG_TYPE_UNSPEC;
4372 	}
4373 }
4374 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4375 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4376 					     enum bpf_attach_type attach_type)
4377 {
4378 	enum bpf_prog_type ptype;
4379 
4380 	switch (prog->type) {
4381 	case BPF_PROG_TYPE_CGROUP_SOCK:
4382 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4383 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4384 	case BPF_PROG_TYPE_SK_LOOKUP:
4385 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4386 	case BPF_PROG_TYPE_CGROUP_SKB:
4387 		if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4388 			/* cg-skb progs can be loaded by unpriv user.
4389 			 * check permissions at attach time.
4390 			 */
4391 			return -EPERM;
4392 
4393 		ptype = attach_type_to_prog_type(attach_type);
4394 		if (prog->type != ptype)
4395 			return -EINVAL;
4396 
4397 		return prog->enforce_expected_attach_type &&
4398 			prog->expected_attach_type != attach_type ?
4399 			-EINVAL : 0;
4400 	case BPF_PROG_TYPE_EXT:
4401 		return 0;
4402 	case BPF_PROG_TYPE_NETFILTER:
4403 		if (attach_type != BPF_NETFILTER)
4404 			return -EINVAL;
4405 		return 0;
4406 	case BPF_PROG_TYPE_PERF_EVENT:
4407 	case BPF_PROG_TYPE_TRACEPOINT:
4408 		if (attach_type != BPF_PERF_EVENT)
4409 			return -EINVAL;
4410 		return 0;
4411 	case BPF_PROG_TYPE_KPROBE:
4412 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4413 		    attach_type != BPF_TRACE_KPROBE_MULTI)
4414 			return -EINVAL;
4415 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4416 		    attach_type != BPF_TRACE_KPROBE_SESSION)
4417 			return -EINVAL;
4418 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4419 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4420 			return -EINVAL;
4421 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_SESSION &&
4422 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4423 			return -EINVAL;
4424 		if (attach_type != BPF_PERF_EVENT &&
4425 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
4426 		    attach_type != BPF_TRACE_KPROBE_SESSION &&
4427 		    attach_type != BPF_TRACE_UPROBE_MULTI &&
4428 		    attach_type != BPF_TRACE_UPROBE_SESSION)
4429 			return -EINVAL;
4430 		return 0;
4431 	case BPF_PROG_TYPE_SCHED_CLS:
4432 		if (attach_type != BPF_TCX_INGRESS &&
4433 		    attach_type != BPF_TCX_EGRESS &&
4434 		    attach_type != BPF_NETKIT_PRIMARY &&
4435 		    attach_type != BPF_NETKIT_PEER)
4436 			return -EINVAL;
4437 		return 0;
4438 	default:
4439 		ptype = attach_type_to_prog_type(attach_type);
4440 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4441 			return -EINVAL;
4442 		return 0;
4443 	}
4444 }
4445 
is_cgroup_prog_type(enum bpf_prog_type ptype,enum bpf_attach_type atype,bool check_atype)4446 static bool is_cgroup_prog_type(enum bpf_prog_type ptype, enum bpf_attach_type atype,
4447 				bool check_atype)
4448 {
4449 	switch (ptype) {
4450 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4451 	case BPF_PROG_TYPE_CGROUP_SKB:
4452 	case BPF_PROG_TYPE_CGROUP_SOCK:
4453 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4454 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4455 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4456 	case BPF_PROG_TYPE_SOCK_OPS:
4457 		return true;
4458 	case BPF_PROG_TYPE_LSM:
4459 		return check_atype ? atype == BPF_LSM_CGROUP : true;
4460 	default:
4461 		return false;
4462 	}
4463 }
4464 
4465 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4466 
4467 #define BPF_F_ATTACH_MASK_BASE	\
4468 	(BPF_F_ALLOW_OVERRIDE |	\
4469 	 BPF_F_ALLOW_MULTI |	\
4470 	 BPF_F_REPLACE |	\
4471 	 BPF_F_PREORDER)
4472 
4473 #define BPF_F_ATTACH_MASK_MPROG	\
4474 	(BPF_F_REPLACE |	\
4475 	 BPF_F_BEFORE |		\
4476 	 BPF_F_AFTER |		\
4477 	 BPF_F_ID |		\
4478 	 BPF_F_LINK)
4479 
bpf_prog_attach(const union bpf_attr * attr)4480 static int bpf_prog_attach(const union bpf_attr *attr)
4481 {
4482 	enum bpf_prog_type ptype;
4483 	struct bpf_prog *prog;
4484 	int ret;
4485 
4486 	if (CHECK_ATTR(BPF_PROG_ATTACH))
4487 		return -EINVAL;
4488 
4489 	ptype = attach_type_to_prog_type(attr->attach_type);
4490 	if (ptype == BPF_PROG_TYPE_UNSPEC)
4491 		return -EINVAL;
4492 	if (bpf_mprog_supported(ptype)) {
4493 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4494 			return -EINVAL;
4495 	} else if (is_cgroup_prog_type(ptype, 0, false)) {
4496 		if (attr->attach_flags & ~(BPF_F_ATTACH_MASK_BASE | BPF_F_ATTACH_MASK_MPROG))
4497 			return -EINVAL;
4498 	} else {
4499 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4500 			return -EINVAL;
4501 		if (attr->relative_fd ||
4502 		    attr->expected_revision)
4503 			return -EINVAL;
4504 	}
4505 
4506 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4507 	if (IS_ERR(prog))
4508 		return PTR_ERR(prog);
4509 
4510 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4511 		bpf_prog_put(prog);
4512 		return -EINVAL;
4513 	}
4514 
4515 	if (is_cgroup_prog_type(ptype, prog->expected_attach_type, true)) {
4516 		ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4517 		goto out;
4518 	}
4519 
4520 	switch (ptype) {
4521 	case BPF_PROG_TYPE_SK_SKB:
4522 	case BPF_PROG_TYPE_SK_MSG:
4523 		ret = sock_map_get_from_fd(attr, prog);
4524 		break;
4525 	case BPF_PROG_TYPE_LIRC_MODE2:
4526 		ret = lirc_prog_attach(attr, prog);
4527 		break;
4528 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4529 		ret = netns_bpf_prog_attach(attr, prog);
4530 		break;
4531 	case BPF_PROG_TYPE_SCHED_CLS:
4532 		if (attr->attach_type == BPF_TCX_INGRESS ||
4533 		    attr->attach_type == BPF_TCX_EGRESS)
4534 			ret = tcx_prog_attach(attr, prog);
4535 		else
4536 			ret = netkit_prog_attach(attr, prog);
4537 		break;
4538 	default:
4539 		ret = -EINVAL;
4540 	}
4541 out:
4542 	if (ret)
4543 		bpf_prog_put(prog);
4544 	return ret;
4545 }
4546 
4547 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4548 
bpf_prog_detach(const union bpf_attr * attr)4549 static int bpf_prog_detach(const union bpf_attr *attr)
4550 {
4551 	struct bpf_prog *prog = NULL;
4552 	enum bpf_prog_type ptype;
4553 	int ret;
4554 
4555 	if (CHECK_ATTR(BPF_PROG_DETACH))
4556 		return -EINVAL;
4557 
4558 	ptype = attach_type_to_prog_type(attr->attach_type);
4559 	if (bpf_mprog_supported(ptype)) {
4560 		if (ptype == BPF_PROG_TYPE_UNSPEC)
4561 			return -EINVAL;
4562 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4563 			return -EINVAL;
4564 		if (attr->attach_bpf_fd) {
4565 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4566 			if (IS_ERR(prog))
4567 				return PTR_ERR(prog);
4568 		}
4569 	} else if (is_cgroup_prog_type(ptype, 0, false)) {
4570 		if (attr->attach_flags || attr->relative_fd)
4571 			return -EINVAL;
4572 	} else if (attr->attach_flags ||
4573 		   attr->relative_fd ||
4574 		   attr->expected_revision) {
4575 		return -EINVAL;
4576 	}
4577 
4578 	switch (ptype) {
4579 	case BPF_PROG_TYPE_SK_MSG:
4580 	case BPF_PROG_TYPE_SK_SKB:
4581 		ret = sock_map_prog_detach(attr, ptype);
4582 		break;
4583 	case BPF_PROG_TYPE_LIRC_MODE2:
4584 		ret = lirc_prog_detach(attr);
4585 		break;
4586 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4587 		ret = netns_bpf_prog_detach(attr, ptype);
4588 		break;
4589 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4590 	case BPF_PROG_TYPE_CGROUP_SKB:
4591 	case BPF_PROG_TYPE_CGROUP_SOCK:
4592 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4593 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4594 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4595 	case BPF_PROG_TYPE_SOCK_OPS:
4596 	case BPF_PROG_TYPE_LSM:
4597 		ret = cgroup_bpf_prog_detach(attr, ptype);
4598 		break;
4599 	case BPF_PROG_TYPE_SCHED_CLS:
4600 		if (attr->attach_type == BPF_TCX_INGRESS ||
4601 		    attr->attach_type == BPF_TCX_EGRESS)
4602 			ret = tcx_prog_detach(attr, prog);
4603 		else
4604 			ret = netkit_prog_detach(attr, prog);
4605 		break;
4606 	default:
4607 		ret = -EINVAL;
4608 	}
4609 
4610 	if (prog)
4611 		bpf_prog_put(prog);
4612 	return ret;
4613 }
4614 
4615 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4616 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4617 static int bpf_prog_query(const union bpf_attr *attr,
4618 			  union bpf_attr __user *uattr)
4619 {
4620 	if (!bpf_net_capable())
4621 		return -EPERM;
4622 	if (CHECK_ATTR(BPF_PROG_QUERY))
4623 		return -EINVAL;
4624 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4625 		return -EINVAL;
4626 
4627 	switch (attr->query.attach_type) {
4628 	case BPF_CGROUP_INET_INGRESS:
4629 	case BPF_CGROUP_INET_EGRESS:
4630 	case BPF_CGROUP_INET_SOCK_CREATE:
4631 	case BPF_CGROUP_INET_SOCK_RELEASE:
4632 	case BPF_CGROUP_INET4_BIND:
4633 	case BPF_CGROUP_INET6_BIND:
4634 	case BPF_CGROUP_INET4_POST_BIND:
4635 	case BPF_CGROUP_INET6_POST_BIND:
4636 	case BPF_CGROUP_INET4_CONNECT:
4637 	case BPF_CGROUP_INET6_CONNECT:
4638 	case BPF_CGROUP_UNIX_CONNECT:
4639 	case BPF_CGROUP_INET4_GETPEERNAME:
4640 	case BPF_CGROUP_INET6_GETPEERNAME:
4641 	case BPF_CGROUP_UNIX_GETPEERNAME:
4642 	case BPF_CGROUP_INET4_GETSOCKNAME:
4643 	case BPF_CGROUP_INET6_GETSOCKNAME:
4644 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4645 	case BPF_CGROUP_UDP4_SENDMSG:
4646 	case BPF_CGROUP_UDP6_SENDMSG:
4647 	case BPF_CGROUP_UNIX_SENDMSG:
4648 	case BPF_CGROUP_UDP4_RECVMSG:
4649 	case BPF_CGROUP_UDP6_RECVMSG:
4650 	case BPF_CGROUP_UNIX_RECVMSG:
4651 	case BPF_CGROUP_SOCK_OPS:
4652 	case BPF_CGROUP_DEVICE:
4653 	case BPF_CGROUP_SYSCTL:
4654 	case BPF_CGROUP_GETSOCKOPT:
4655 	case BPF_CGROUP_SETSOCKOPT:
4656 	case BPF_LSM_CGROUP:
4657 		return cgroup_bpf_prog_query(attr, uattr);
4658 	case BPF_LIRC_MODE2:
4659 		return lirc_prog_query(attr, uattr);
4660 	case BPF_FLOW_DISSECTOR:
4661 	case BPF_SK_LOOKUP:
4662 		return netns_bpf_prog_query(attr, uattr);
4663 	case BPF_SK_SKB_STREAM_PARSER:
4664 	case BPF_SK_SKB_STREAM_VERDICT:
4665 	case BPF_SK_MSG_VERDICT:
4666 	case BPF_SK_SKB_VERDICT:
4667 		return sock_map_bpf_prog_query(attr, uattr);
4668 	case BPF_TCX_INGRESS:
4669 	case BPF_TCX_EGRESS:
4670 		return tcx_prog_query(attr, uattr);
4671 	case BPF_NETKIT_PRIMARY:
4672 	case BPF_NETKIT_PEER:
4673 		return netkit_prog_query(attr, uattr);
4674 	default:
4675 		return -EINVAL;
4676 	}
4677 }
4678 
4679 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4680 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4681 static int bpf_prog_test_run(const union bpf_attr *attr,
4682 			     union bpf_attr __user *uattr)
4683 {
4684 	struct bpf_prog *prog;
4685 	int ret = -ENOTSUPP;
4686 
4687 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4688 		return -EINVAL;
4689 
4690 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4691 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4692 		return -EINVAL;
4693 
4694 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4695 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4696 		return -EINVAL;
4697 
4698 	prog = bpf_prog_get(attr->test.prog_fd);
4699 	if (IS_ERR(prog))
4700 		return PTR_ERR(prog);
4701 
4702 	if (prog->aux->ops->test_run)
4703 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4704 
4705 	bpf_prog_put(prog);
4706 	return ret;
4707 }
4708 
4709 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4710 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4711 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4712 			       union bpf_attr __user *uattr,
4713 			       struct idr *idr,
4714 			       spinlock_t *lock)
4715 {
4716 	u32 next_id = attr->start_id;
4717 	int err = 0;
4718 
4719 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4720 		return -EINVAL;
4721 
4722 	if (!capable(CAP_SYS_ADMIN))
4723 		return -EPERM;
4724 
4725 	next_id++;
4726 	spin_lock_bh(lock);
4727 	if (!idr_get_next(idr, &next_id))
4728 		err = -ENOENT;
4729 	spin_unlock_bh(lock);
4730 
4731 	if (!err)
4732 		err = put_user(next_id, &uattr->next_id);
4733 
4734 	return err;
4735 }
4736 
bpf_map_get_curr_or_next(u32 * id)4737 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4738 {
4739 	struct bpf_map *map;
4740 
4741 	spin_lock_bh(&map_idr_lock);
4742 again:
4743 	map = idr_get_next(&map_idr, id);
4744 	if (map) {
4745 		map = __bpf_map_inc_not_zero(map, false);
4746 		if (IS_ERR(map)) {
4747 			(*id)++;
4748 			goto again;
4749 		}
4750 	}
4751 	spin_unlock_bh(&map_idr_lock);
4752 
4753 	return map;
4754 }
4755 
bpf_prog_get_curr_or_next(u32 * id)4756 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4757 {
4758 	struct bpf_prog *prog;
4759 
4760 	spin_lock_bh(&prog_idr_lock);
4761 again:
4762 	prog = idr_get_next(&prog_idr, id);
4763 	if (prog) {
4764 		prog = bpf_prog_inc_not_zero(prog);
4765 		if (IS_ERR(prog)) {
4766 			(*id)++;
4767 			goto again;
4768 		}
4769 	}
4770 	spin_unlock_bh(&prog_idr_lock);
4771 
4772 	return prog;
4773 }
4774 
4775 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4776 
bpf_prog_by_id(u32 id)4777 struct bpf_prog *bpf_prog_by_id(u32 id)
4778 {
4779 	struct bpf_prog *prog;
4780 
4781 	if (!id)
4782 		return ERR_PTR(-ENOENT);
4783 
4784 	spin_lock_bh(&prog_idr_lock);
4785 	prog = idr_find(&prog_idr, id);
4786 	if (prog)
4787 		prog = bpf_prog_inc_not_zero(prog);
4788 	else
4789 		prog = ERR_PTR(-ENOENT);
4790 	spin_unlock_bh(&prog_idr_lock);
4791 	return prog;
4792 }
4793 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4794 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4795 {
4796 	struct bpf_prog *prog;
4797 	u32 id = attr->prog_id;
4798 	int fd;
4799 
4800 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4801 		return -EINVAL;
4802 
4803 	if (!capable(CAP_SYS_ADMIN))
4804 		return -EPERM;
4805 
4806 	prog = bpf_prog_by_id(id);
4807 	if (IS_ERR(prog))
4808 		return PTR_ERR(prog);
4809 
4810 	fd = bpf_prog_new_fd(prog);
4811 	if (fd < 0)
4812 		bpf_prog_put(prog);
4813 
4814 	return fd;
4815 }
4816 
4817 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4818 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4819 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4820 {
4821 	struct bpf_map *map;
4822 	u32 id = attr->map_id;
4823 	int f_flags;
4824 	int fd;
4825 
4826 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4827 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4828 		return -EINVAL;
4829 
4830 	if (!capable(CAP_SYS_ADMIN))
4831 		return -EPERM;
4832 
4833 	f_flags = bpf_get_file_flag(attr->open_flags);
4834 	if (f_flags < 0)
4835 		return f_flags;
4836 
4837 	spin_lock_bh(&map_idr_lock);
4838 	map = idr_find(&map_idr, id);
4839 	if (map)
4840 		map = __bpf_map_inc_not_zero(map, true);
4841 	else
4842 		map = ERR_PTR(-ENOENT);
4843 	spin_unlock_bh(&map_idr_lock);
4844 
4845 	if (IS_ERR(map))
4846 		return PTR_ERR(map);
4847 
4848 	fd = bpf_map_new_fd(map, f_flags);
4849 	if (fd < 0)
4850 		bpf_map_put_with_uref(map);
4851 
4852 	return fd;
4853 }
4854 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4855 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4856 					      unsigned long addr, u32 *off,
4857 					      u32 *type)
4858 {
4859 	const struct bpf_map *map;
4860 	int i;
4861 
4862 	mutex_lock(&prog->aux->used_maps_mutex);
4863 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4864 		map = prog->aux->used_maps[i];
4865 		if (map == (void *)addr) {
4866 			*type = BPF_PSEUDO_MAP_FD;
4867 			goto out;
4868 		}
4869 		if (!map->ops->map_direct_value_meta)
4870 			continue;
4871 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4872 			*type = BPF_PSEUDO_MAP_VALUE;
4873 			goto out;
4874 		}
4875 	}
4876 	map = NULL;
4877 
4878 out:
4879 	mutex_unlock(&prog->aux->used_maps_mutex);
4880 	return map;
4881 }
4882 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4883 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4884 					      const struct cred *f_cred)
4885 {
4886 	const struct bpf_map *map;
4887 	struct bpf_insn *insns;
4888 	u32 off, type;
4889 	u64 imm;
4890 	u8 code;
4891 	int i;
4892 
4893 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4894 			GFP_USER);
4895 	if (!insns)
4896 		return insns;
4897 
4898 	for (i = 0; i < prog->len; i++) {
4899 		code = insns[i].code;
4900 
4901 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4902 			insns[i].code = BPF_JMP | BPF_CALL;
4903 			insns[i].imm = BPF_FUNC_tail_call;
4904 			/* fall-through */
4905 		}
4906 		if (code == (BPF_JMP | BPF_CALL) ||
4907 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4908 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4909 				insns[i].code = BPF_JMP | BPF_CALL;
4910 			if (!bpf_dump_raw_ok(f_cred))
4911 				insns[i].imm = 0;
4912 			continue;
4913 		}
4914 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4915 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4916 			continue;
4917 		}
4918 
4919 		if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4920 		     BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4921 			insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4922 			continue;
4923 		}
4924 
4925 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4926 			continue;
4927 
4928 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4929 		map = bpf_map_from_imm(prog, imm, &off, &type);
4930 		if (map) {
4931 			insns[i].src_reg = type;
4932 			insns[i].imm = map->id;
4933 			insns[i + 1].imm = off;
4934 			continue;
4935 		}
4936 	}
4937 
4938 	return insns;
4939 }
4940 
set_info_rec_size(struct bpf_prog_info * info)4941 static int set_info_rec_size(struct bpf_prog_info *info)
4942 {
4943 	/*
4944 	 * Ensure info.*_rec_size is the same as kernel expected size
4945 	 *
4946 	 * or
4947 	 *
4948 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4949 	 * zero.  In this case, the kernel will set the expected
4950 	 * _rec_size back to the info.
4951 	 */
4952 
4953 	if ((info->nr_func_info || info->func_info_rec_size) &&
4954 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4955 		return -EINVAL;
4956 
4957 	if ((info->nr_line_info || info->line_info_rec_size) &&
4958 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
4959 		return -EINVAL;
4960 
4961 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4962 	    info->jited_line_info_rec_size != sizeof(__u64))
4963 		return -EINVAL;
4964 
4965 	info->func_info_rec_size = sizeof(struct bpf_func_info);
4966 	info->line_info_rec_size = sizeof(struct bpf_line_info);
4967 	info->jited_line_info_rec_size = sizeof(__u64);
4968 
4969 	return 0;
4970 }
4971 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4972 static int bpf_prog_get_info_by_fd(struct file *file,
4973 				   struct bpf_prog *prog,
4974 				   const union bpf_attr *attr,
4975 				   union bpf_attr __user *uattr)
4976 {
4977 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4978 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4979 	struct bpf_prog_info info;
4980 	u32 info_len = attr->info.info_len;
4981 	struct bpf_prog_kstats stats;
4982 	char __user *uinsns;
4983 	u32 ulen;
4984 	int err;
4985 
4986 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4987 	if (err)
4988 		return err;
4989 	info_len = min_t(u32, sizeof(info), info_len);
4990 
4991 	memset(&info, 0, sizeof(info));
4992 	if (copy_from_user(&info, uinfo, info_len))
4993 		return -EFAULT;
4994 
4995 	info.type = prog->type;
4996 	info.id = prog->aux->id;
4997 	info.load_time = prog->aux->load_time;
4998 	info.created_by_uid = from_kuid_munged(current_user_ns(),
4999 					       prog->aux->user->uid);
5000 	info.gpl_compatible = prog->gpl_compatible;
5001 
5002 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
5003 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
5004 
5005 	mutex_lock(&prog->aux->used_maps_mutex);
5006 	ulen = info.nr_map_ids;
5007 	info.nr_map_ids = prog->aux->used_map_cnt;
5008 	ulen = min_t(u32, info.nr_map_ids, ulen);
5009 	if (ulen) {
5010 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
5011 		u32 i;
5012 
5013 		for (i = 0; i < ulen; i++)
5014 			if (put_user(prog->aux->used_maps[i]->id,
5015 				     &user_map_ids[i])) {
5016 				mutex_unlock(&prog->aux->used_maps_mutex);
5017 				return -EFAULT;
5018 			}
5019 	}
5020 	mutex_unlock(&prog->aux->used_maps_mutex);
5021 
5022 	err = set_info_rec_size(&info);
5023 	if (err)
5024 		return err;
5025 
5026 	bpf_prog_get_stats(prog, &stats);
5027 	info.run_time_ns = stats.nsecs;
5028 	info.run_cnt = stats.cnt;
5029 	info.recursion_misses = stats.misses;
5030 
5031 	info.verified_insns = prog->aux->verified_insns;
5032 	if (prog->aux->btf)
5033 		info.btf_id = btf_obj_id(prog->aux->btf);
5034 
5035 	if (!bpf_capable()) {
5036 		info.jited_prog_len = 0;
5037 		info.xlated_prog_len = 0;
5038 		info.nr_jited_ksyms = 0;
5039 		info.nr_jited_func_lens = 0;
5040 		info.nr_func_info = 0;
5041 		info.nr_line_info = 0;
5042 		info.nr_jited_line_info = 0;
5043 		goto done;
5044 	}
5045 
5046 	ulen = info.xlated_prog_len;
5047 	info.xlated_prog_len = bpf_prog_insn_size(prog);
5048 	if (info.xlated_prog_len && ulen) {
5049 		struct bpf_insn *insns_sanitized;
5050 		bool fault;
5051 
5052 		if (!prog->blinded || bpf_dump_raw_ok(file->f_cred)) {
5053 			insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
5054 			if (!insns_sanitized)
5055 				return -ENOMEM;
5056 			uinsns = u64_to_user_ptr(info.xlated_prog_insns);
5057 			ulen = min_t(u32, info.xlated_prog_len, ulen);
5058 			fault = copy_to_user(uinsns, insns_sanitized, ulen);
5059 			kfree(insns_sanitized);
5060 			if (fault)
5061 				return -EFAULT;
5062 		} else {
5063 			info.xlated_prog_insns = 0;
5064 		}
5065 	}
5066 
5067 	if (bpf_prog_is_offloaded(prog->aux)) {
5068 		err = bpf_prog_offload_info_fill(&info, prog);
5069 		if (err)
5070 			return err;
5071 		goto done;
5072 	}
5073 
5074 	/* NOTE: the following code is supposed to be skipped for offload.
5075 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
5076 	 * for offload.
5077 	 */
5078 	ulen = info.jited_prog_len;
5079 	if (prog->aux->func_cnt) {
5080 		u32 i;
5081 
5082 		info.jited_prog_len = 0;
5083 		for (i = 0; i < prog->aux->func_cnt; i++)
5084 			info.jited_prog_len += prog->aux->func[i]->jited_len;
5085 	} else {
5086 		info.jited_prog_len = prog->jited_len;
5087 	}
5088 
5089 	if (info.jited_prog_len && ulen) {
5090 		if (bpf_dump_raw_ok(file->f_cred)) {
5091 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
5092 			ulen = min_t(u32, info.jited_prog_len, ulen);
5093 
5094 			/* for multi-function programs, copy the JITed
5095 			 * instructions for all the functions
5096 			 */
5097 			if (prog->aux->func_cnt) {
5098 				u32 len, free, i;
5099 				u8 *img;
5100 
5101 				free = ulen;
5102 				for (i = 0; i < prog->aux->func_cnt; i++) {
5103 					len = prog->aux->func[i]->jited_len;
5104 					len = min_t(u32, len, free);
5105 					img = (u8 *) prog->aux->func[i]->bpf_func;
5106 					if (copy_to_user(uinsns, img, len))
5107 						return -EFAULT;
5108 					uinsns += len;
5109 					free -= len;
5110 					if (!free)
5111 						break;
5112 				}
5113 			} else {
5114 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
5115 					return -EFAULT;
5116 			}
5117 		} else {
5118 			info.jited_prog_insns = 0;
5119 		}
5120 	}
5121 
5122 	ulen = info.nr_jited_ksyms;
5123 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
5124 	if (ulen) {
5125 		if (bpf_dump_raw_ok(file->f_cred)) {
5126 			unsigned long ksym_addr;
5127 			u64 __user *user_ksyms;
5128 			u32 i;
5129 
5130 			/* copy the address of the kernel symbol
5131 			 * corresponding to each function
5132 			 */
5133 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
5134 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
5135 			if (prog->aux->func_cnt) {
5136 				for (i = 0; i < ulen; i++) {
5137 					ksym_addr = (unsigned long)
5138 						prog->aux->func[i]->bpf_func;
5139 					if (put_user((u64) ksym_addr,
5140 						     &user_ksyms[i]))
5141 						return -EFAULT;
5142 				}
5143 			} else {
5144 				ksym_addr = (unsigned long) prog->bpf_func;
5145 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
5146 					return -EFAULT;
5147 			}
5148 		} else {
5149 			info.jited_ksyms = 0;
5150 		}
5151 	}
5152 
5153 	ulen = info.nr_jited_func_lens;
5154 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
5155 	if (ulen) {
5156 		if (bpf_dump_raw_ok(file->f_cred)) {
5157 			u32 __user *user_lens;
5158 			u32 func_len, i;
5159 
5160 			/* copy the JITed image lengths for each function */
5161 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
5162 			user_lens = u64_to_user_ptr(info.jited_func_lens);
5163 			if (prog->aux->func_cnt) {
5164 				for (i = 0; i < ulen; i++) {
5165 					func_len =
5166 						prog->aux->func[i]->jited_len;
5167 					if (put_user(func_len, &user_lens[i]))
5168 						return -EFAULT;
5169 				}
5170 			} else {
5171 				func_len = prog->jited_len;
5172 				if (put_user(func_len, &user_lens[0]))
5173 					return -EFAULT;
5174 			}
5175 		} else {
5176 			info.jited_func_lens = 0;
5177 		}
5178 	}
5179 
5180 	info.attach_btf_id = prog->aux->attach_btf_id;
5181 	if (attach_btf)
5182 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
5183 
5184 	ulen = info.nr_func_info;
5185 	info.nr_func_info = prog->aux->func_info_cnt;
5186 	if (info.nr_func_info && ulen) {
5187 		char __user *user_finfo;
5188 
5189 		user_finfo = u64_to_user_ptr(info.func_info);
5190 		ulen = min_t(u32, info.nr_func_info, ulen);
5191 		if (copy_to_user(user_finfo, prog->aux->func_info,
5192 				 info.func_info_rec_size * ulen))
5193 			return -EFAULT;
5194 	}
5195 
5196 	ulen = info.nr_line_info;
5197 	info.nr_line_info = prog->aux->nr_linfo;
5198 	if (info.nr_line_info && ulen) {
5199 		__u8 __user *user_linfo;
5200 
5201 		user_linfo = u64_to_user_ptr(info.line_info);
5202 		ulen = min_t(u32, info.nr_line_info, ulen);
5203 		if (copy_to_user(user_linfo, prog->aux->linfo,
5204 				 info.line_info_rec_size * ulen))
5205 			return -EFAULT;
5206 	}
5207 
5208 	ulen = info.nr_jited_line_info;
5209 	if (prog->aux->jited_linfo)
5210 		info.nr_jited_line_info = prog->aux->nr_linfo;
5211 	else
5212 		info.nr_jited_line_info = 0;
5213 	if (info.nr_jited_line_info && ulen) {
5214 		if (bpf_dump_raw_ok(file->f_cred)) {
5215 			unsigned long line_addr;
5216 			__u64 __user *user_linfo;
5217 			u32 i;
5218 
5219 			user_linfo = u64_to_user_ptr(info.jited_line_info);
5220 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
5221 			for (i = 0; i < ulen; i++) {
5222 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
5223 				if (put_user((__u64)line_addr, &user_linfo[i]))
5224 					return -EFAULT;
5225 			}
5226 		} else {
5227 			info.jited_line_info = 0;
5228 		}
5229 	}
5230 
5231 	ulen = info.nr_prog_tags;
5232 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
5233 	if (ulen) {
5234 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
5235 		u32 i;
5236 
5237 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
5238 		ulen = min_t(u32, info.nr_prog_tags, ulen);
5239 		if (prog->aux->func_cnt) {
5240 			for (i = 0; i < ulen; i++) {
5241 				if (copy_to_user(user_prog_tags[i],
5242 						 prog->aux->func[i]->tag,
5243 						 BPF_TAG_SIZE))
5244 					return -EFAULT;
5245 			}
5246 		} else {
5247 			if (copy_to_user(user_prog_tags[0],
5248 					 prog->tag, BPF_TAG_SIZE))
5249 				return -EFAULT;
5250 		}
5251 	}
5252 
5253 done:
5254 	if (copy_to_user(uinfo, &info, info_len) ||
5255 	    put_user(info_len, &uattr->info.info_len))
5256 		return -EFAULT;
5257 
5258 	return 0;
5259 }
5260 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)5261 static int bpf_map_get_info_by_fd(struct file *file,
5262 				  struct bpf_map *map,
5263 				  const union bpf_attr *attr,
5264 				  union bpf_attr __user *uattr)
5265 {
5266 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5267 	struct bpf_map_info info;
5268 	u32 info_len = attr->info.info_len;
5269 	int err;
5270 
5271 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5272 	if (err)
5273 		return err;
5274 	info_len = min_t(u32, sizeof(info), info_len);
5275 
5276 	memset(&info, 0, sizeof(info));
5277 	if (copy_from_user(&info, uinfo, info_len))
5278 		return -EFAULT;
5279 
5280 	info.type = map->map_type;
5281 	info.id = map->id;
5282 	info.key_size = map->key_size;
5283 	info.value_size = map->value_size;
5284 	info.max_entries = map->max_entries;
5285 	info.map_flags = map->map_flags;
5286 	info.map_extra = map->map_extra;
5287 	memcpy(info.name, map->name, sizeof(map->name));
5288 
5289 	if (map->btf) {
5290 		info.btf_id = btf_obj_id(map->btf);
5291 		info.btf_key_type_id = map->btf_key_type_id;
5292 		info.btf_value_type_id = map->btf_value_type_id;
5293 	}
5294 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
5295 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
5296 		bpf_map_struct_ops_info_fill(&info, map);
5297 
5298 	if (bpf_map_is_offloaded(map)) {
5299 		err = bpf_map_offload_info_fill(&info, map);
5300 		if (err)
5301 			return err;
5302 	}
5303 
5304 	if (info.hash) {
5305 		char __user *uhash = u64_to_user_ptr(info.hash);
5306 
5307 		if (!map->ops->map_get_hash)
5308 			return -EINVAL;
5309 
5310 		if (info.hash_size != SHA256_DIGEST_SIZE)
5311 			return -EINVAL;
5312 
5313 		err = map->ops->map_get_hash(map, SHA256_DIGEST_SIZE, map->sha);
5314 		if (err != 0)
5315 			return err;
5316 
5317 		if (copy_to_user(uhash, map->sha, SHA256_DIGEST_SIZE) != 0)
5318 			return -EFAULT;
5319 	} else if (info.hash_size) {
5320 		return -EINVAL;
5321 	}
5322 
5323 	if (copy_to_user(uinfo, &info, info_len) ||
5324 	    put_user(info_len, &uattr->info.info_len))
5325 		return -EFAULT;
5326 
5327 	return 0;
5328 }
5329 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)5330 static int bpf_btf_get_info_by_fd(struct file *file,
5331 				  struct btf *btf,
5332 				  const union bpf_attr *attr,
5333 				  union bpf_attr __user *uattr)
5334 {
5335 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5336 	u32 info_len = attr->info.info_len;
5337 	int err;
5338 
5339 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5340 	if (err)
5341 		return err;
5342 
5343 	return btf_get_info_by_fd(btf, attr, uattr);
5344 }
5345 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)5346 static int bpf_link_get_info_by_fd(struct file *file,
5347 				  struct bpf_link *link,
5348 				  const union bpf_attr *attr,
5349 				  union bpf_attr __user *uattr)
5350 {
5351 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5352 	struct bpf_link_info info;
5353 	u32 info_len = attr->info.info_len;
5354 	int err;
5355 
5356 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
5357 	if (err)
5358 		return err;
5359 	info_len = min_t(u32, sizeof(info), info_len);
5360 
5361 	memset(&info, 0, sizeof(info));
5362 	if (copy_from_user(&info, uinfo, info_len))
5363 		return -EFAULT;
5364 
5365 	info.type = link->type;
5366 	info.id = link->id;
5367 	if (link->prog)
5368 		info.prog_id = link->prog->aux->id;
5369 
5370 	if (link->ops->fill_link_info) {
5371 		err = link->ops->fill_link_info(link, &info);
5372 		if (err)
5373 			return err;
5374 	}
5375 
5376 	if (copy_to_user(uinfo, &info, info_len) ||
5377 	    put_user(info_len, &uattr->info.info_len))
5378 		return -EFAULT;
5379 
5380 	return 0;
5381 }
5382 
5383 
token_get_info_by_fd(struct file * file,struct bpf_token * token,const union bpf_attr * attr,union bpf_attr __user * uattr)5384 static int token_get_info_by_fd(struct file *file,
5385 				struct bpf_token *token,
5386 				const union bpf_attr *attr,
5387 				union bpf_attr __user *uattr)
5388 {
5389 	struct bpf_token_info __user *uinfo = u64_to_user_ptr(attr->info.info);
5390 	u32 info_len = attr->info.info_len;
5391 	int err;
5392 
5393 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
5394 	if (err)
5395 		return err;
5396 	return bpf_token_get_info_by_fd(token, attr, uattr);
5397 }
5398 
5399 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
5400 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)5401 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
5402 				  union bpf_attr __user *uattr)
5403 {
5404 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
5405 		return -EINVAL;
5406 
5407 	CLASS(fd, f)(attr->info.bpf_fd);
5408 	if (fd_empty(f))
5409 		return -EBADFD;
5410 
5411 	if (fd_file(f)->f_op == &bpf_prog_fops)
5412 		return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5413 					      uattr);
5414 	else if (fd_file(f)->f_op == &bpf_map_fops)
5415 		return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
5416 					     uattr);
5417 	else if (fd_file(f)->f_op == &btf_fops)
5418 		return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
5419 	else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
5420 		return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5421 					      attr, uattr);
5422 	else if (fd_file(f)->f_op == &bpf_token_fops)
5423 		return token_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
5424 					    attr, uattr);
5425 	return -EINVAL;
5426 }
5427 
5428 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5429 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5430 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5431 {
5432 	struct bpf_token *token = NULL;
5433 
5434 	if (CHECK_ATTR(BPF_BTF_LOAD))
5435 		return -EINVAL;
5436 
5437 	if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5438 		return -EINVAL;
5439 
5440 	if (attr->btf_flags & BPF_F_TOKEN_FD) {
5441 		token = bpf_token_get_from_fd(attr->btf_token_fd);
5442 		if (IS_ERR(token))
5443 			return PTR_ERR(token);
5444 		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5445 			bpf_token_put(token);
5446 			token = NULL;
5447 		}
5448 	}
5449 
5450 	if (!bpf_token_capable(token, CAP_BPF)) {
5451 		bpf_token_put(token);
5452 		return -EPERM;
5453 	}
5454 
5455 	bpf_token_put(token);
5456 
5457 	return btf_new_fd(attr, uattr, uattr_size);
5458 }
5459 
5460 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD fd_by_id_token_fd
5461 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5462 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5463 {
5464 	struct bpf_token *token = NULL;
5465 
5466 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5467 		return -EINVAL;
5468 
5469 	if (attr->open_flags & ~BPF_F_TOKEN_FD)
5470 		return -EINVAL;
5471 
5472 	if (attr->open_flags & BPF_F_TOKEN_FD) {
5473 		token = bpf_token_get_from_fd(attr->fd_by_id_token_fd);
5474 		if (IS_ERR(token))
5475 			return PTR_ERR(token);
5476 		if (!bpf_token_allow_cmd(token, BPF_BTF_GET_FD_BY_ID)) {
5477 			bpf_token_put(token);
5478 			token = NULL;
5479 		}
5480 	}
5481 
5482 	if (!bpf_token_capable(token, CAP_SYS_ADMIN)) {
5483 		bpf_token_put(token);
5484 		return -EPERM;
5485 	}
5486 
5487 	bpf_token_put(token);
5488 
5489 	return btf_get_fd_by_id(attr->btf_id);
5490 }
5491 
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)5492 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5493 				    union bpf_attr __user *uattr,
5494 				    u32 prog_id, u32 fd_type,
5495 				    const char *buf, u64 probe_offset,
5496 				    u64 probe_addr)
5497 {
5498 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5499 	u32 len = buf ? strlen(buf) : 0, input_len;
5500 	int err = 0;
5501 
5502 	if (put_user(len, &uattr->task_fd_query.buf_len))
5503 		return -EFAULT;
5504 	input_len = attr->task_fd_query.buf_len;
5505 	if (input_len && ubuf) {
5506 		if (!len) {
5507 			/* nothing to copy, just make ubuf NULL terminated */
5508 			char zero = '\0';
5509 
5510 			if (put_user(zero, ubuf))
5511 				return -EFAULT;
5512 		} else {
5513 			err = bpf_copy_to_user(ubuf, buf, input_len, len);
5514 			if (err == -EFAULT)
5515 				return err;
5516 		}
5517 	}
5518 
5519 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5520 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5521 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5522 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5523 		return -EFAULT;
5524 
5525 	return err;
5526 }
5527 
5528 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5529 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5530 static int bpf_task_fd_query(const union bpf_attr *attr,
5531 			     union bpf_attr __user *uattr)
5532 {
5533 	pid_t pid = attr->task_fd_query.pid;
5534 	u32 fd = attr->task_fd_query.fd;
5535 	const struct perf_event *event;
5536 	struct task_struct *task;
5537 	struct file *file;
5538 	int err;
5539 
5540 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5541 		return -EINVAL;
5542 
5543 	if (!capable(CAP_SYS_ADMIN))
5544 		return -EPERM;
5545 
5546 	if (attr->task_fd_query.flags != 0)
5547 		return -EINVAL;
5548 
5549 	rcu_read_lock();
5550 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5551 	rcu_read_unlock();
5552 	if (!task)
5553 		return -ENOENT;
5554 
5555 	err = 0;
5556 	file = fget_task(task, fd);
5557 	put_task_struct(task);
5558 	if (!file)
5559 		return -EBADF;
5560 
5561 	if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5562 		struct bpf_link *link = file->private_data;
5563 
5564 		if (link->ops == &bpf_raw_tp_link_lops) {
5565 			struct bpf_raw_tp_link *raw_tp =
5566 				container_of(link, struct bpf_raw_tp_link, link);
5567 			struct bpf_raw_event_map *btp = raw_tp->btp;
5568 
5569 			err = bpf_task_fd_query_copy(attr, uattr,
5570 						     raw_tp->link.prog->aux->id,
5571 						     BPF_FD_TYPE_RAW_TRACEPOINT,
5572 						     btp->tp->name, 0, 0);
5573 			goto put_file;
5574 		}
5575 		goto out_not_supp;
5576 	}
5577 
5578 	event = perf_get_event(file);
5579 	if (!IS_ERR(event)) {
5580 		u64 probe_offset, probe_addr;
5581 		u32 prog_id, fd_type;
5582 		const char *buf;
5583 
5584 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5585 					      &buf, &probe_offset,
5586 					      &probe_addr, NULL);
5587 		if (!err)
5588 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5589 						     fd_type, buf,
5590 						     probe_offset,
5591 						     probe_addr);
5592 		goto put_file;
5593 	}
5594 
5595 out_not_supp:
5596 	err = -ENOTSUPP;
5597 put_file:
5598 	fput(file);
5599 	return err;
5600 }
5601 
5602 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5603 
5604 #define BPF_DO_BATCH(fn, ...)			\
5605 	do {					\
5606 		if (!fn) {			\
5607 			err = -ENOTSUPP;	\
5608 			goto err_put;		\
5609 		}				\
5610 		err = fn(__VA_ARGS__);		\
5611 	} while (0)
5612 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5613 static int bpf_map_do_batch(const union bpf_attr *attr,
5614 			    union bpf_attr __user *uattr,
5615 			    int cmd)
5616 {
5617 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
5618 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5619 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5620 	struct bpf_map *map;
5621 	int err;
5622 
5623 	if (CHECK_ATTR(BPF_MAP_BATCH))
5624 		return -EINVAL;
5625 
5626 	CLASS(fd, f)(attr->batch.map_fd);
5627 
5628 	map = __bpf_map_get(f);
5629 	if (IS_ERR(map))
5630 		return PTR_ERR(map);
5631 	if (has_write)
5632 		bpf_map_write_active_inc(map);
5633 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5634 		err = -EPERM;
5635 		goto err_put;
5636 	}
5637 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5638 		err = -EPERM;
5639 		goto err_put;
5640 	}
5641 
5642 	if (cmd == BPF_MAP_LOOKUP_BATCH)
5643 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5644 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5645 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5646 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5647 		BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
5648 	else
5649 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5650 err_put:
5651 	if (has_write) {
5652 		maybe_wait_bpf_programs(map);
5653 		bpf_map_write_active_dec(map);
5654 	}
5655 	return err;
5656 }
5657 
5658 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5659 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5660 {
5661 	struct bpf_prog *prog;
5662 	int ret;
5663 
5664 	if (CHECK_ATTR(BPF_LINK_CREATE))
5665 		return -EINVAL;
5666 
5667 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5668 		return bpf_struct_ops_link_create(attr);
5669 
5670 	prog = bpf_prog_get(attr->link_create.prog_fd);
5671 	if (IS_ERR(prog))
5672 		return PTR_ERR(prog);
5673 
5674 	ret = bpf_prog_attach_check_attach_type(prog,
5675 						attr->link_create.attach_type);
5676 	if (ret)
5677 		goto out;
5678 
5679 	switch (prog->type) {
5680 	case BPF_PROG_TYPE_CGROUP_SKB:
5681 	case BPF_PROG_TYPE_CGROUP_SOCK:
5682 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5683 	case BPF_PROG_TYPE_SOCK_OPS:
5684 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5685 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5686 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5687 		ret = cgroup_bpf_link_attach(attr, prog);
5688 		break;
5689 	case BPF_PROG_TYPE_EXT:
5690 		ret = bpf_tracing_prog_attach(prog,
5691 					      attr->link_create.target_fd,
5692 					      attr->link_create.target_btf_id,
5693 					      attr->link_create.tracing.cookie,
5694 					      attr->link_create.attach_type);
5695 		break;
5696 	case BPF_PROG_TYPE_LSM:
5697 	case BPF_PROG_TYPE_TRACING:
5698 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5699 			ret = -EINVAL;
5700 			goto out;
5701 		}
5702 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5703 			ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie,
5704 						     attr->link_create.attach_type);
5705 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5706 			ret = bpf_iter_link_attach(attr, uattr, prog);
5707 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5708 			ret = cgroup_bpf_link_attach(attr, prog);
5709 		else
5710 			ret = bpf_tracing_prog_attach(prog,
5711 						      attr->link_create.target_fd,
5712 						      attr->link_create.target_btf_id,
5713 						      attr->link_create.tracing.cookie,
5714 						      attr->link_create.attach_type);
5715 		break;
5716 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5717 	case BPF_PROG_TYPE_SK_LOOKUP:
5718 		ret = netns_bpf_link_create(attr, prog);
5719 		break;
5720 	case BPF_PROG_TYPE_SK_MSG:
5721 	case BPF_PROG_TYPE_SK_SKB:
5722 		ret = sock_map_link_create(attr, prog);
5723 		break;
5724 #ifdef CONFIG_NET
5725 	case BPF_PROG_TYPE_XDP:
5726 		ret = bpf_xdp_link_attach(attr, prog);
5727 		break;
5728 	case BPF_PROG_TYPE_SCHED_CLS:
5729 		if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5730 		    attr->link_create.attach_type == BPF_TCX_EGRESS)
5731 			ret = tcx_link_attach(attr, prog);
5732 		else
5733 			ret = netkit_link_attach(attr, prog);
5734 		break;
5735 	case BPF_PROG_TYPE_NETFILTER:
5736 		ret = bpf_nf_link_attach(attr, prog);
5737 		break;
5738 #endif
5739 	case BPF_PROG_TYPE_PERF_EVENT:
5740 	case BPF_PROG_TYPE_TRACEPOINT:
5741 		ret = bpf_perf_link_attach(attr, prog);
5742 		break;
5743 	case BPF_PROG_TYPE_KPROBE:
5744 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5745 			ret = bpf_perf_link_attach(attr, prog);
5746 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5747 			 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5748 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5749 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI ||
5750 			 attr->link_create.attach_type == BPF_TRACE_UPROBE_SESSION)
5751 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5752 		break;
5753 	default:
5754 		ret = -EINVAL;
5755 	}
5756 
5757 out:
5758 	if (ret < 0)
5759 		bpf_prog_put(prog);
5760 	return ret;
5761 }
5762 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5763 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5764 {
5765 	struct bpf_map *new_map, *old_map = NULL;
5766 	int ret;
5767 
5768 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5769 	if (IS_ERR(new_map))
5770 		return PTR_ERR(new_map);
5771 
5772 	if (attr->link_update.flags & BPF_F_REPLACE) {
5773 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5774 		if (IS_ERR(old_map)) {
5775 			ret = PTR_ERR(old_map);
5776 			goto out_put;
5777 		}
5778 	} else if (attr->link_update.old_map_fd) {
5779 		ret = -EINVAL;
5780 		goto out_put;
5781 	}
5782 
5783 	ret = link->ops->update_map(link, new_map, old_map);
5784 
5785 	if (old_map)
5786 		bpf_map_put(old_map);
5787 out_put:
5788 	bpf_map_put(new_map);
5789 	return ret;
5790 }
5791 
5792 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5793 
link_update(union bpf_attr * attr)5794 static int link_update(union bpf_attr *attr)
5795 {
5796 	struct bpf_prog *old_prog = NULL, *new_prog;
5797 	struct bpf_link *link;
5798 	u32 flags;
5799 	int ret;
5800 
5801 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5802 		return -EINVAL;
5803 
5804 	flags = attr->link_update.flags;
5805 	if (flags & ~BPF_F_REPLACE)
5806 		return -EINVAL;
5807 
5808 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5809 	if (IS_ERR(link))
5810 		return PTR_ERR(link);
5811 
5812 	if (link->ops->update_map) {
5813 		ret = link_update_map(link, attr);
5814 		goto out_put_link;
5815 	}
5816 
5817 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5818 	if (IS_ERR(new_prog)) {
5819 		ret = PTR_ERR(new_prog);
5820 		goto out_put_link;
5821 	}
5822 
5823 	if (flags & BPF_F_REPLACE) {
5824 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5825 		if (IS_ERR(old_prog)) {
5826 			ret = PTR_ERR(old_prog);
5827 			old_prog = NULL;
5828 			goto out_put_progs;
5829 		}
5830 	} else if (attr->link_update.old_prog_fd) {
5831 		ret = -EINVAL;
5832 		goto out_put_progs;
5833 	}
5834 
5835 	if (link->ops->update_prog)
5836 		ret = link->ops->update_prog(link, new_prog, old_prog);
5837 	else
5838 		ret = -EINVAL;
5839 
5840 out_put_progs:
5841 	if (old_prog)
5842 		bpf_prog_put(old_prog);
5843 	if (ret)
5844 		bpf_prog_put(new_prog);
5845 out_put_link:
5846 	bpf_link_put_direct(link);
5847 	return ret;
5848 }
5849 
5850 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5851 
link_detach(union bpf_attr * attr)5852 static int link_detach(union bpf_attr *attr)
5853 {
5854 	struct bpf_link *link;
5855 	int ret;
5856 
5857 	if (CHECK_ATTR(BPF_LINK_DETACH))
5858 		return -EINVAL;
5859 
5860 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5861 	if (IS_ERR(link))
5862 		return PTR_ERR(link);
5863 
5864 	if (link->ops->detach)
5865 		ret = link->ops->detach(link);
5866 	else
5867 		ret = -EOPNOTSUPP;
5868 
5869 	bpf_link_put_direct(link);
5870 	return ret;
5871 }
5872 
bpf_link_inc_not_zero(struct bpf_link * link)5873 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5874 {
5875 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5876 }
5877 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5878 
bpf_link_by_id(u32 id)5879 struct bpf_link *bpf_link_by_id(u32 id)
5880 {
5881 	struct bpf_link *link;
5882 
5883 	if (!id)
5884 		return ERR_PTR(-ENOENT);
5885 
5886 	spin_lock_bh(&link_idr_lock);
5887 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5888 	link = idr_find(&link_idr, id);
5889 	if (link) {
5890 		if (link->id)
5891 			link = bpf_link_inc_not_zero(link);
5892 		else
5893 			link = ERR_PTR(-EAGAIN);
5894 	} else {
5895 		link = ERR_PTR(-ENOENT);
5896 	}
5897 	spin_unlock_bh(&link_idr_lock);
5898 	return link;
5899 }
5900 
bpf_link_get_curr_or_next(u32 * id)5901 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5902 {
5903 	struct bpf_link *link;
5904 
5905 	spin_lock_bh(&link_idr_lock);
5906 again:
5907 	link = idr_get_next(&link_idr, id);
5908 	if (link) {
5909 		link = bpf_link_inc_not_zero(link);
5910 		if (IS_ERR(link)) {
5911 			(*id)++;
5912 			goto again;
5913 		}
5914 	}
5915 	spin_unlock_bh(&link_idr_lock);
5916 
5917 	return link;
5918 }
5919 
5920 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5921 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5922 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5923 {
5924 	struct bpf_link *link;
5925 	u32 id = attr->link_id;
5926 	int fd;
5927 
5928 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5929 		return -EINVAL;
5930 
5931 	if (!capable(CAP_SYS_ADMIN))
5932 		return -EPERM;
5933 
5934 	link = bpf_link_by_id(id);
5935 	if (IS_ERR(link))
5936 		return PTR_ERR(link);
5937 
5938 	fd = bpf_link_new_fd(link);
5939 	if (fd < 0)
5940 		bpf_link_put_direct(link);
5941 
5942 	return fd;
5943 }
5944 
5945 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5946 
bpf_stats_release(struct inode * inode,struct file * file)5947 static int bpf_stats_release(struct inode *inode, struct file *file)
5948 {
5949 	mutex_lock(&bpf_stats_enabled_mutex);
5950 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5951 	mutex_unlock(&bpf_stats_enabled_mutex);
5952 	return 0;
5953 }
5954 
5955 static const struct file_operations bpf_stats_fops = {
5956 	.release = bpf_stats_release,
5957 };
5958 
bpf_enable_runtime_stats(void)5959 static int bpf_enable_runtime_stats(void)
5960 {
5961 	int fd;
5962 
5963 	mutex_lock(&bpf_stats_enabled_mutex);
5964 
5965 	/* Set a very high limit to avoid overflow */
5966 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5967 		mutex_unlock(&bpf_stats_enabled_mutex);
5968 		return -EBUSY;
5969 	}
5970 
5971 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5972 	if (fd >= 0)
5973 		static_key_slow_inc(&bpf_stats_enabled_key.key);
5974 
5975 	mutex_unlock(&bpf_stats_enabled_mutex);
5976 	return fd;
5977 }
5978 
5979 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5980 
bpf_enable_stats(union bpf_attr * attr)5981 static int bpf_enable_stats(union bpf_attr *attr)
5982 {
5983 
5984 	if (CHECK_ATTR(BPF_ENABLE_STATS))
5985 		return -EINVAL;
5986 
5987 	if (!capable(CAP_SYS_ADMIN))
5988 		return -EPERM;
5989 
5990 	switch (attr->enable_stats.type) {
5991 	case BPF_STATS_RUN_TIME:
5992 		return bpf_enable_runtime_stats();
5993 	default:
5994 		break;
5995 	}
5996 	return -EINVAL;
5997 }
5998 
5999 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
6000 
bpf_iter_create(union bpf_attr * attr)6001 static int bpf_iter_create(union bpf_attr *attr)
6002 {
6003 	struct bpf_link *link;
6004 	int err;
6005 
6006 	if (CHECK_ATTR(BPF_ITER_CREATE))
6007 		return -EINVAL;
6008 
6009 	if (attr->iter_create.flags)
6010 		return -EINVAL;
6011 
6012 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
6013 	if (IS_ERR(link))
6014 		return PTR_ERR(link);
6015 
6016 	err = bpf_iter_new_fd(link);
6017 	bpf_link_put_direct(link);
6018 
6019 	return err;
6020 }
6021 
6022 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
6023 
bpf_prog_bind_map(union bpf_attr * attr)6024 static int bpf_prog_bind_map(union bpf_attr *attr)
6025 {
6026 	struct bpf_prog *prog;
6027 	struct bpf_map *map;
6028 	struct bpf_map **used_maps_old, **used_maps_new;
6029 	int i, ret = 0;
6030 
6031 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
6032 		return -EINVAL;
6033 
6034 	if (attr->prog_bind_map.flags)
6035 		return -EINVAL;
6036 
6037 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
6038 	if (IS_ERR(prog))
6039 		return PTR_ERR(prog);
6040 
6041 	map = bpf_map_get(attr->prog_bind_map.map_fd);
6042 	if (IS_ERR(map)) {
6043 		ret = PTR_ERR(map);
6044 		goto out_prog_put;
6045 	}
6046 
6047 	mutex_lock(&prog->aux->used_maps_mutex);
6048 
6049 	used_maps_old = prog->aux->used_maps;
6050 
6051 	for (i = 0; i < prog->aux->used_map_cnt; i++)
6052 		if (used_maps_old[i] == map) {
6053 			bpf_map_put(map);
6054 			goto out_unlock;
6055 		}
6056 
6057 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
6058 				      sizeof(used_maps_new[0]),
6059 				      GFP_KERNEL);
6060 	if (!used_maps_new) {
6061 		ret = -ENOMEM;
6062 		goto out_unlock;
6063 	}
6064 
6065 	/* The bpf program will not access the bpf map, but for the sake of
6066 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
6067 	 */
6068 	if (prog->sleepable)
6069 		atomic64_inc(&map->sleepable_refcnt);
6070 	memcpy(used_maps_new, used_maps_old,
6071 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
6072 	used_maps_new[prog->aux->used_map_cnt] = map;
6073 
6074 	prog->aux->used_map_cnt++;
6075 	prog->aux->used_maps = used_maps_new;
6076 
6077 	kfree(used_maps_old);
6078 
6079 out_unlock:
6080 	mutex_unlock(&prog->aux->used_maps_mutex);
6081 
6082 	if (ret)
6083 		bpf_map_put(map);
6084 out_prog_put:
6085 	bpf_prog_put(prog);
6086 	return ret;
6087 }
6088 
6089 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
6090 
token_create(union bpf_attr * attr)6091 static int token_create(union bpf_attr *attr)
6092 {
6093 	if (CHECK_ATTR(BPF_TOKEN_CREATE))
6094 		return -EINVAL;
6095 
6096 	/* no flags are supported yet */
6097 	if (attr->token_create.flags)
6098 		return -EINVAL;
6099 
6100 	return bpf_token_create(attr);
6101 }
6102 
6103 #define BPF_PROG_STREAM_READ_BY_FD_LAST_FIELD prog_stream_read.prog_fd
6104 
prog_stream_read(union bpf_attr * attr)6105 static int prog_stream_read(union bpf_attr *attr)
6106 {
6107 	char __user *buf = u64_to_user_ptr(attr->prog_stream_read.stream_buf);
6108 	u32 len = attr->prog_stream_read.stream_buf_len;
6109 	struct bpf_prog *prog;
6110 	int ret;
6111 
6112 	if (CHECK_ATTR(BPF_PROG_STREAM_READ_BY_FD))
6113 		return -EINVAL;
6114 
6115 	prog = bpf_prog_get(attr->prog_stream_read.prog_fd);
6116 	if (IS_ERR(prog))
6117 		return PTR_ERR(prog);
6118 
6119 	ret = bpf_prog_stream_read(prog, attr->prog_stream_read.stream_id, buf, len);
6120 	bpf_prog_put(prog);
6121 
6122 	return ret;
6123 }
6124 
__sys_bpf(enum bpf_cmd cmd,bpfptr_t uattr,unsigned int size)6125 static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
6126 {
6127 	union bpf_attr attr;
6128 	int err;
6129 
6130 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
6131 	if (err)
6132 		return err;
6133 	size = min_t(u32, size, sizeof(attr));
6134 
6135 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
6136 	memset(&attr, 0, sizeof(attr));
6137 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
6138 		return -EFAULT;
6139 
6140 	err = security_bpf(cmd, &attr, size, uattr.is_kernel);
6141 	if (err < 0)
6142 		return err;
6143 
6144 	switch (cmd) {
6145 	case BPF_MAP_CREATE:
6146 		err = map_create(&attr, uattr);
6147 		break;
6148 	case BPF_MAP_LOOKUP_ELEM:
6149 		err = map_lookup_elem(&attr);
6150 		break;
6151 	case BPF_MAP_UPDATE_ELEM:
6152 		err = map_update_elem(&attr, uattr);
6153 		break;
6154 	case BPF_MAP_DELETE_ELEM:
6155 		err = map_delete_elem(&attr, uattr);
6156 		break;
6157 	case BPF_MAP_GET_NEXT_KEY:
6158 		err = map_get_next_key(&attr);
6159 		break;
6160 	case BPF_MAP_FREEZE:
6161 		err = map_freeze(&attr);
6162 		break;
6163 	case BPF_PROG_LOAD:
6164 		err = bpf_prog_load(&attr, uattr, size);
6165 		break;
6166 	case BPF_OBJ_PIN:
6167 		err = bpf_obj_pin(&attr);
6168 		break;
6169 	case BPF_OBJ_GET:
6170 		err = bpf_obj_get(&attr);
6171 		break;
6172 	case BPF_PROG_ATTACH:
6173 		err = bpf_prog_attach(&attr);
6174 		break;
6175 	case BPF_PROG_DETACH:
6176 		err = bpf_prog_detach(&attr);
6177 		break;
6178 	case BPF_PROG_QUERY:
6179 		err = bpf_prog_query(&attr, uattr.user);
6180 		break;
6181 	case BPF_PROG_TEST_RUN:
6182 		err = bpf_prog_test_run(&attr, uattr.user);
6183 		break;
6184 	case BPF_PROG_GET_NEXT_ID:
6185 		err = bpf_obj_get_next_id(&attr, uattr.user,
6186 					  &prog_idr, &prog_idr_lock);
6187 		break;
6188 	case BPF_MAP_GET_NEXT_ID:
6189 		err = bpf_obj_get_next_id(&attr, uattr.user,
6190 					  &map_idr, &map_idr_lock);
6191 		break;
6192 	case BPF_BTF_GET_NEXT_ID:
6193 		err = bpf_obj_get_next_id(&attr, uattr.user,
6194 					  &btf_idr, &btf_idr_lock);
6195 		break;
6196 	case BPF_PROG_GET_FD_BY_ID:
6197 		err = bpf_prog_get_fd_by_id(&attr);
6198 		break;
6199 	case BPF_MAP_GET_FD_BY_ID:
6200 		err = bpf_map_get_fd_by_id(&attr);
6201 		break;
6202 	case BPF_OBJ_GET_INFO_BY_FD:
6203 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
6204 		break;
6205 	case BPF_RAW_TRACEPOINT_OPEN:
6206 		err = bpf_raw_tracepoint_open(&attr);
6207 		break;
6208 	case BPF_BTF_LOAD:
6209 		err = bpf_btf_load(&attr, uattr, size);
6210 		break;
6211 	case BPF_BTF_GET_FD_BY_ID:
6212 		err = bpf_btf_get_fd_by_id(&attr);
6213 		break;
6214 	case BPF_TASK_FD_QUERY:
6215 		err = bpf_task_fd_query(&attr, uattr.user);
6216 		break;
6217 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
6218 		err = map_lookup_and_delete_elem(&attr);
6219 		break;
6220 	case BPF_MAP_LOOKUP_BATCH:
6221 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
6222 		break;
6223 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
6224 		err = bpf_map_do_batch(&attr, uattr.user,
6225 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
6226 		break;
6227 	case BPF_MAP_UPDATE_BATCH:
6228 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
6229 		break;
6230 	case BPF_MAP_DELETE_BATCH:
6231 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
6232 		break;
6233 	case BPF_LINK_CREATE:
6234 		err = link_create(&attr, uattr);
6235 		break;
6236 	case BPF_LINK_UPDATE:
6237 		err = link_update(&attr);
6238 		break;
6239 	case BPF_LINK_GET_FD_BY_ID:
6240 		err = bpf_link_get_fd_by_id(&attr);
6241 		break;
6242 	case BPF_LINK_GET_NEXT_ID:
6243 		err = bpf_obj_get_next_id(&attr, uattr.user,
6244 					  &link_idr, &link_idr_lock);
6245 		break;
6246 	case BPF_ENABLE_STATS:
6247 		err = bpf_enable_stats(&attr);
6248 		break;
6249 	case BPF_ITER_CREATE:
6250 		err = bpf_iter_create(&attr);
6251 		break;
6252 	case BPF_LINK_DETACH:
6253 		err = link_detach(&attr);
6254 		break;
6255 	case BPF_PROG_BIND_MAP:
6256 		err = bpf_prog_bind_map(&attr);
6257 		break;
6258 	case BPF_TOKEN_CREATE:
6259 		err = token_create(&attr);
6260 		break;
6261 	case BPF_PROG_STREAM_READ_BY_FD:
6262 		err = prog_stream_read(&attr);
6263 		break;
6264 	default:
6265 		err = -EINVAL;
6266 		break;
6267 	}
6268 
6269 	return err;
6270 }
6271 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)6272 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
6273 {
6274 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
6275 }
6276 
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)6277 static bool syscall_prog_is_valid_access(int off, int size,
6278 					 enum bpf_access_type type,
6279 					 const struct bpf_prog *prog,
6280 					 struct bpf_insn_access_aux *info)
6281 {
6282 	if (off < 0 || off >= U16_MAX)
6283 		return false;
6284 	if (off % size != 0)
6285 		return false;
6286 	return true;
6287 }
6288 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)6289 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
6290 {
6291 	switch (cmd) {
6292 	case BPF_MAP_CREATE:
6293 	case BPF_MAP_DELETE_ELEM:
6294 	case BPF_MAP_UPDATE_ELEM:
6295 	case BPF_MAP_FREEZE:
6296 	case BPF_MAP_GET_FD_BY_ID:
6297 	case BPF_PROG_LOAD:
6298 	case BPF_BTF_LOAD:
6299 	case BPF_LINK_CREATE:
6300 	case BPF_RAW_TRACEPOINT_OPEN:
6301 		break;
6302 	default:
6303 		return -EINVAL;
6304 	}
6305 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
6306 }
6307 
6308 
6309 /* To shut up -Wmissing-prototypes.
6310  * This function is used by the kernel light skeleton
6311  * to load bpf programs when modules are loaded or during kernel boot.
6312  * See tools/lib/bpf/skel_internal.h
6313  */
6314 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
6315 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)6316 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
6317 {
6318 	struct bpf_prog * __maybe_unused prog;
6319 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
6320 
6321 	switch (cmd) {
6322 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
6323 	case BPF_PROG_TEST_RUN:
6324 		if (attr->test.data_in || attr->test.data_out ||
6325 		    attr->test.ctx_out || attr->test.duration ||
6326 		    attr->test.repeat || attr->test.flags)
6327 			return -EINVAL;
6328 
6329 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
6330 		if (IS_ERR(prog))
6331 			return PTR_ERR(prog);
6332 
6333 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
6334 		    attr->test.ctx_size_in > U16_MAX) {
6335 			bpf_prog_put(prog);
6336 			return -EINVAL;
6337 		}
6338 
6339 		run_ctx.bpf_cookie = 0;
6340 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
6341 			/* recursion detected */
6342 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
6343 			bpf_prog_put(prog);
6344 			return -EBUSY;
6345 		}
6346 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
6347 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
6348 						&run_ctx);
6349 		bpf_prog_put(prog);
6350 		return 0;
6351 #endif
6352 	default:
6353 		return ____bpf_sys_bpf(cmd, attr, size);
6354 	}
6355 }
6356 EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL");
6357 
6358 static const struct bpf_func_proto bpf_sys_bpf_proto = {
6359 	.func		= bpf_sys_bpf,
6360 	.gpl_only	= false,
6361 	.ret_type	= RET_INTEGER,
6362 	.arg1_type	= ARG_ANYTHING,
6363 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
6364 	.arg3_type	= ARG_CONST_SIZE,
6365 };
6366 
6367 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6368 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6369 {
6370 	return bpf_base_func_proto(func_id, prog);
6371 }
6372 
BPF_CALL_1(bpf_sys_close,u32,fd)6373 BPF_CALL_1(bpf_sys_close, u32, fd)
6374 {
6375 	/* When bpf program calls this helper there should not be
6376 	 * an fdget() without matching completed fdput().
6377 	 * This helper is allowed in the following callchain only:
6378 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
6379 	 */
6380 	return close_fd(fd);
6381 }
6382 
6383 static const struct bpf_func_proto bpf_sys_close_proto = {
6384 	.func		= bpf_sys_close,
6385 	.gpl_only	= false,
6386 	.ret_type	= RET_INTEGER,
6387 	.arg1_type	= ARG_ANYTHING,
6388 };
6389 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)6390 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
6391 {
6392 	*res = 0;
6393 	if (flags)
6394 		return -EINVAL;
6395 
6396 	if (name_sz <= 1 || name[name_sz - 1])
6397 		return -EINVAL;
6398 
6399 	if (!bpf_dump_raw_ok(current_cred()))
6400 		return -EPERM;
6401 
6402 	*res = kallsyms_lookup_name(name);
6403 	return *res ? 0 : -ENOENT;
6404 }
6405 
6406 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
6407 	.func		= bpf_kallsyms_lookup_name,
6408 	.gpl_only	= false,
6409 	.ret_type	= RET_INTEGER,
6410 	.arg1_type	= ARG_PTR_TO_MEM,
6411 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
6412 	.arg3_type	= ARG_ANYTHING,
6413 	.arg4_type	= ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
6414 	.arg4_size	= sizeof(u64),
6415 };
6416 
6417 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)6418 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
6419 {
6420 	switch (func_id) {
6421 	case BPF_FUNC_sys_bpf:
6422 		return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
6423 		       ? NULL : &bpf_sys_bpf_proto;
6424 	case BPF_FUNC_btf_find_by_name_kind:
6425 		return &bpf_btf_find_by_name_kind_proto;
6426 	case BPF_FUNC_sys_close:
6427 		return &bpf_sys_close_proto;
6428 	case BPF_FUNC_kallsyms_lookup_name:
6429 		return &bpf_kallsyms_lookup_name_proto;
6430 	default:
6431 		return tracing_prog_func_proto(func_id, prog);
6432 	}
6433 }
6434 
6435 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
6436 	.get_func_proto  = syscall_prog_func_proto,
6437 	.is_valid_access = syscall_prog_is_valid_access,
6438 };
6439 
6440 const struct bpf_prog_ops bpf_syscall_prog_ops = {
6441 	.test_run = bpf_prog_test_run_syscall,
6442 };
6443 
6444 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6445 static int bpf_stats_handler(const struct ctl_table *table, int write,
6446 			     void *buffer, size_t *lenp, loff_t *ppos)
6447 {
6448 	struct static_key *key = (struct static_key *)table->data;
6449 	static int saved_val;
6450 	int val, ret;
6451 	struct ctl_table tmp = {
6452 		.data   = &val,
6453 		.maxlen = sizeof(val),
6454 		.mode   = table->mode,
6455 		.extra1 = SYSCTL_ZERO,
6456 		.extra2 = SYSCTL_ONE,
6457 	};
6458 
6459 	if (write && !capable(CAP_SYS_ADMIN))
6460 		return -EPERM;
6461 
6462 	mutex_lock(&bpf_stats_enabled_mutex);
6463 	val = saved_val;
6464 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6465 	if (write && !ret && val != saved_val) {
6466 		if (val)
6467 			static_key_slow_inc(key);
6468 		else
6469 			static_key_slow_dec(key);
6470 		saved_val = val;
6471 	}
6472 	mutex_unlock(&bpf_stats_enabled_mutex);
6473 	return ret;
6474 }
6475 
unpriv_ebpf_notify(int new_state)6476 void __weak unpriv_ebpf_notify(int new_state)
6477 {
6478 }
6479 
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6480 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6481 			      void *buffer, size_t *lenp, loff_t *ppos)
6482 {
6483 	int ret, unpriv_enable = *(int *)table->data;
6484 	bool locked_state = unpriv_enable == 1;
6485 	struct ctl_table tmp = *table;
6486 
6487 	if (write && !capable(CAP_SYS_ADMIN))
6488 		return -EPERM;
6489 
6490 	tmp.data = &unpriv_enable;
6491 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6492 	if (write && !ret) {
6493 		if (locked_state && unpriv_enable != 1)
6494 			return -EPERM;
6495 		*(int *)table->data = unpriv_enable;
6496 	}
6497 
6498 	if (write)
6499 		unpriv_ebpf_notify(unpriv_enable);
6500 
6501 	return ret;
6502 }
6503 
6504 static const struct ctl_table bpf_syscall_table[] = {
6505 	{
6506 		.procname	= "unprivileged_bpf_disabled",
6507 		.data		= &sysctl_unprivileged_bpf_disabled,
6508 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
6509 		.mode		= 0644,
6510 		.proc_handler	= bpf_unpriv_handler,
6511 		.extra1		= SYSCTL_ZERO,
6512 		.extra2		= SYSCTL_TWO,
6513 	},
6514 	{
6515 		.procname	= "bpf_stats_enabled",
6516 		.data		= &bpf_stats_enabled_key.key,
6517 		.mode		= 0644,
6518 		.proc_handler	= bpf_stats_handler,
6519 	},
6520 };
6521 
bpf_syscall_sysctl_init(void)6522 static int __init bpf_syscall_sysctl_init(void)
6523 {
6524 	register_sysctl_init("kernel", bpf_syscall_table);
6525 	return 0;
6526 }
6527 late_initcall(bpf_syscall_sysctl_init);
6528 #endif /* CONFIG_SYSCTL */
6529