xref: /linux/kernel/bpf/syscall.c (revision 2884dc7d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3  */
4 #include <linux/bpf.h>
5 #include <linux/bpf-cgroup.h>
6 #include <linux/bpf_trace.h>
7 #include <linux/bpf_lirc.h>
8 #include <linux/bpf_verifier.h>
9 #include <linux/bsearch.h>
10 #include <linux/btf.h>
11 #include <linux/syscalls.h>
12 #include <linux/slab.h>
13 #include <linux/sched/signal.h>
14 #include <linux/vmalloc.h>
15 #include <linux/mmzone.h>
16 #include <linux/anon_inodes.h>
17 #include <linux/fdtable.h>
18 #include <linux/file.h>
19 #include <linux/fs.h>
20 #include <linux/license.h>
21 #include <linux/filter.h>
22 #include <linux/kernel.h>
23 #include <linux/idr.h>
24 #include <linux/cred.h>
25 #include <linux/timekeeping.h>
26 #include <linux/ctype.h>
27 #include <linux/nospec.h>
28 #include <linux/audit.h>
29 #include <uapi/linux/btf.h>
30 #include <linux/pgtable.h>
31 #include <linux/bpf_lsm.h>
32 #include <linux/poll.h>
33 #include <linux/sort.h>
34 #include <linux/bpf-netns.h>
35 #include <linux/rcupdate_trace.h>
36 #include <linux/memcontrol.h>
37 #include <linux/trace_events.h>
38 
39 #include <net/netfilter/nf_bpf_link.h>
40 #include <net/netkit.h>
41 #include <net/tcx.h>
42 
43 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
44 			  (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
45 			  (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
46 #define IS_FD_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
47 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
48 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map) || \
49 			IS_FD_HASH(map))
50 
51 #define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
52 
53 DEFINE_PER_CPU(int, bpf_prog_active);
54 static DEFINE_IDR(prog_idr);
55 static DEFINE_SPINLOCK(prog_idr_lock);
56 static DEFINE_IDR(map_idr);
57 static DEFINE_SPINLOCK(map_idr_lock);
58 static DEFINE_IDR(link_idr);
59 static DEFINE_SPINLOCK(link_idr_lock);
60 
61 int sysctl_unprivileged_bpf_disabled __read_mostly =
62 	IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
63 
64 static const struct bpf_map_ops * const bpf_map_types[] = {
65 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
66 #define BPF_MAP_TYPE(_id, _ops) \
67 	[_id] = &_ops,
68 #define BPF_LINK_TYPE(_id, _name)
69 #include <linux/bpf_types.h>
70 #undef BPF_PROG_TYPE
71 #undef BPF_MAP_TYPE
72 #undef BPF_LINK_TYPE
73 };
74 
75 /*
76  * If we're handed a bigger struct than we know of, ensure all the unknown bits
77  * are 0 - i.e. new user-space does not rely on any kernel feature extensions
78  * we don't know about yet.
79  *
80  * There is a ToCToU between this function call and the following
81  * copy_from_user() call. However, this is not a concern since this function is
82  * meant to be a future-proofing of bits.
83  */
bpf_check_uarg_tail_zero(bpfptr_t uaddr,size_t expected_size,size_t actual_size)84 int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
85 			     size_t expected_size,
86 			     size_t actual_size)
87 {
88 	int res;
89 
90 	if (unlikely(actual_size > PAGE_SIZE))	/* silly large */
91 		return -E2BIG;
92 
93 	if (actual_size <= expected_size)
94 		return 0;
95 
96 	if (uaddr.is_kernel)
97 		res = memchr_inv(uaddr.kernel + expected_size, 0,
98 				 actual_size - expected_size) == NULL;
99 	else
100 		res = check_zeroed_user(uaddr.user + expected_size,
101 					actual_size - expected_size);
102 	if (res < 0)
103 		return res;
104 	return res ? 0 : -E2BIG;
105 }
106 
107 const struct bpf_map_ops bpf_map_offload_ops = {
108 	.map_meta_equal = bpf_map_meta_equal,
109 	.map_alloc = bpf_map_offload_map_alloc,
110 	.map_free = bpf_map_offload_map_free,
111 	.map_check_btf = map_check_no_btf,
112 	.map_mem_usage = bpf_map_offload_map_mem_usage,
113 };
114 
bpf_map_write_active_inc(struct bpf_map * map)115 static void bpf_map_write_active_inc(struct bpf_map *map)
116 {
117 	atomic64_inc(&map->writecnt);
118 }
119 
bpf_map_write_active_dec(struct bpf_map * map)120 static void bpf_map_write_active_dec(struct bpf_map *map)
121 {
122 	atomic64_dec(&map->writecnt);
123 }
124 
bpf_map_write_active(const struct bpf_map * map)125 bool bpf_map_write_active(const struct bpf_map *map)
126 {
127 	return atomic64_read(&map->writecnt) != 0;
128 }
129 
bpf_map_value_size(const struct bpf_map * map)130 static u32 bpf_map_value_size(const struct bpf_map *map)
131 {
132 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
133 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
134 	    map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY ||
135 	    map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
136 		return round_up(map->value_size, 8) * num_possible_cpus();
137 	else if (IS_FD_MAP(map))
138 		return sizeof(u32);
139 	else
140 		return  map->value_size;
141 }
142 
maybe_wait_bpf_programs(struct bpf_map * map)143 static void maybe_wait_bpf_programs(struct bpf_map *map)
144 {
145 	/* Wait for any running non-sleepable BPF programs to complete so that
146 	 * userspace, when we return to it, knows that all non-sleepable
147 	 * programs that could be running use the new map value. For sleepable
148 	 * BPF programs, synchronize_rcu_tasks_trace() should be used to wait
149 	 * for the completions of these programs, but considering the waiting
150 	 * time can be very long and userspace may think it will hang forever,
151 	 * so don't handle sleepable BPF programs now.
152 	 */
153 	if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
154 	    map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
155 		synchronize_rcu();
156 }
157 
bpf_map_update_value(struct bpf_map * map,struct file * map_file,void * key,void * value,__u64 flags)158 static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
159 				void *key, void *value, __u64 flags)
160 {
161 	int err;
162 
163 	/* Need to create a kthread, thus must support schedule */
164 	if (bpf_map_is_offloaded(map)) {
165 		return bpf_map_offload_update_elem(map, key, value, flags);
166 	} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
167 		   map->map_type == BPF_MAP_TYPE_ARENA ||
168 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
169 		return map->ops->map_update_elem(map, key, value, flags);
170 	} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
171 		   map->map_type == BPF_MAP_TYPE_SOCKMAP) {
172 		return sock_map_update_elem_sys(map, key, value, flags);
173 	} else if (IS_FD_PROG_ARRAY(map)) {
174 		return bpf_fd_array_map_update_elem(map, map_file, key, value,
175 						    flags);
176 	}
177 
178 	bpf_disable_instrumentation();
179 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
180 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
181 		err = bpf_percpu_hash_update(map, key, value, flags);
182 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
183 		err = bpf_percpu_array_update(map, key, value, flags);
184 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
185 		err = bpf_percpu_cgroup_storage_update(map, key, value,
186 						       flags);
187 	} else if (IS_FD_ARRAY(map)) {
188 		err = bpf_fd_array_map_update_elem(map, map_file, key, value,
189 						   flags);
190 	} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
191 		err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
192 						  flags);
193 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
194 		/* rcu_read_lock() is not needed */
195 		err = bpf_fd_reuseport_array_update_elem(map, key, value,
196 							 flags);
197 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
198 		   map->map_type == BPF_MAP_TYPE_STACK ||
199 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
200 		err = map->ops->map_push_elem(map, value, flags);
201 	} else {
202 		rcu_read_lock();
203 		err = map->ops->map_update_elem(map, key, value, flags);
204 		rcu_read_unlock();
205 	}
206 	bpf_enable_instrumentation();
207 
208 	return err;
209 }
210 
bpf_map_copy_value(struct bpf_map * map,void * key,void * value,__u64 flags)211 static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
212 			      __u64 flags)
213 {
214 	void *ptr;
215 	int err;
216 
217 	if (bpf_map_is_offloaded(map))
218 		return bpf_map_offload_lookup_elem(map, key, value);
219 
220 	bpf_disable_instrumentation();
221 	if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
222 	    map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
223 		err = bpf_percpu_hash_copy(map, key, value);
224 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
225 		err = bpf_percpu_array_copy(map, key, value);
226 	} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
227 		err = bpf_percpu_cgroup_storage_copy(map, key, value);
228 	} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
229 		err = bpf_stackmap_copy(map, key, value);
230 	} else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {
231 		err = bpf_fd_array_map_lookup_elem(map, key, value);
232 	} else if (IS_FD_HASH(map)) {
233 		err = bpf_fd_htab_map_lookup_elem(map, key, value);
234 	} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
235 		err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
236 	} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
237 		   map->map_type == BPF_MAP_TYPE_STACK ||
238 		   map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
239 		err = map->ops->map_peek_elem(map, value);
240 	} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
241 		/* struct_ops map requires directly updating "value" */
242 		err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
243 	} else {
244 		rcu_read_lock();
245 		if (map->ops->map_lookup_elem_sys_only)
246 			ptr = map->ops->map_lookup_elem_sys_only(map, key);
247 		else
248 			ptr = map->ops->map_lookup_elem(map, key);
249 		if (IS_ERR(ptr)) {
250 			err = PTR_ERR(ptr);
251 		} else if (!ptr) {
252 			err = -ENOENT;
253 		} else {
254 			err = 0;
255 			if (flags & BPF_F_LOCK)
256 				/* lock 'ptr' and copy everything but lock */
257 				copy_map_value_locked(map, value, ptr, true);
258 			else
259 				copy_map_value(map, value, ptr);
260 			/* mask lock and timer, since value wasn't zero inited */
261 			check_and_init_map_value(map, value);
262 		}
263 		rcu_read_unlock();
264 	}
265 
266 	bpf_enable_instrumentation();
267 
268 	return err;
269 }
270 
271 /* Please, do not use this function outside from the map creation path
272  * (e.g. in map update path) without taking care of setting the active
273  * memory cgroup (see at bpf_map_kmalloc_node() for example).
274  */
__bpf_map_area_alloc(u64 size,int numa_node,bool mmapable)275 static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
276 {
277 	/* We really just want to fail instead of triggering OOM killer
278 	 * under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
279 	 * which is used for lower order allocation requests.
280 	 *
281 	 * It has been observed that higher order allocation requests done by
282 	 * vmalloc with __GFP_NORETRY being set might fail due to not trying
283 	 * to reclaim memory from the page cache, thus we set
284 	 * __GFP_RETRY_MAYFAIL to avoid such situations.
285 	 */
286 
287 	gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
288 	unsigned int flags = 0;
289 	unsigned long align = 1;
290 	void *area;
291 
292 	if (size >= SIZE_MAX)
293 		return NULL;
294 
295 	/* kmalloc()'ed memory can't be mmap()'ed */
296 	if (mmapable) {
297 		BUG_ON(!PAGE_ALIGNED(size));
298 		align = SHMLBA;
299 		flags = VM_USERMAP;
300 	} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
301 		area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
302 				    numa_node);
303 		if (area != NULL)
304 			return area;
305 	}
306 
307 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
308 			gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
309 			flags, numa_node, __builtin_return_address(0));
310 }
311 
bpf_map_area_alloc(u64 size,int numa_node)312 void *bpf_map_area_alloc(u64 size, int numa_node)
313 {
314 	return __bpf_map_area_alloc(size, numa_node, false);
315 }
316 
bpf_map_area_mmapable_alloc(u64 size,int numa_node)317 void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
318 {
319 	return __bpf_map_area_alloc(size, numa_node, true);
320 }
321 
bpf_map_area_free(void * area)322 void bpf_map_area_free(void *area)
323 {
324 	kvfree(area);
325 }
326 
bpf_map_flags_retain_permanent(u32 flags)327 static u32 bpf_map_flags_retain_permanent(u32 flags)
328 {
329 	/* Some map creation flags are not tied to the map object but
330 	 * rather to the map fd instead, so they have no meaning upon
331 	 * map object inspection since multiple file descriptors with
332 	 * different (access) properties can exist here. Thus, given
333 	 * this has zero meaning for the map itself, lets clear these
334 	 * from here.
335 	 */
336 	return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
337 }
338 
bpf_map_init_from_attr(struct bpf_map * map,union bpf_attr * attr)339 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
340 {
341 	map->map_type = attr->map_type;
342 	map->key_size = attr->key_size;
343 	map->value_size = attr->value_size;
344 	map->max_entries = attr->max_entries;
345 	map->map_flags = bpf_map_flags_retain_permanent(attr->map_flags);
346 	map->numa_node = bpf_map_attr_numa_node(attr);
347 	map->map_extra = attr->map_extra;
348 }
349 
bpf_map_alloc_id(struct bpf_map * map)350 static int bpf_map_alloc_id(struct bpf_map *map)
351 {
352 	int id;
353 
354 	idr_preload(GFP_KERNEL);
355 	spin_lock_bh(&map_idr_lock);
356 	id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
357 	if (id > 0)
358 		map->id = id;
359 	spin_unlock_bh(&map_idr_lock);
360 	idr_preload_end();
361 
362 	if (WARN_ON_ONCE(!id))
363 		return -ENOSPC;
364 
365 	return id > 0 ? 0 : id;
366 }
367 
bpf_map_free_id(struct bpf_map * map)368 void bpf_map_free_id(struct bpf_map *map)
369 {
370 	unsigned long flags;
371 
372 	/* Offloaded maps are removed from the IDR store when their device
373 	 * disappears - even if someone holds an fd to them they are unusable,
374 	 * the memory is gone, all ops will fail; they are simply waiting for
375 	 * refcnt to drop to be freed.
376 	 */
377 	if (!map->id)
378 		return;
379 
380 	spin_lock_irqsave(&map_idr_lock, flags);
381 
382 	idr_remove(&map_idr, map->id);
383 	map->id = 0;
384 
385 	spin_unlock_irqrestore(&map_idr_lock, flags);
386 }
387 
388 #ifdef CONFIG_MEMCG_KMEM
bpf_map_save_memcg(struct bpf_map * map)389 static void bpf_map_save_memcg(struct bpf_map *map)
390 {
391 	/* Currently if a map is created by a process belonging to the root
392 	 * memory cgroup, get_obj_cgroup_from_current() will return NULL.
393 	 * So we have to check map->objcg for being NULL each time it's
394 	 * being used.
395 	 */
396 	if (memcg_bpf_enabled())
397 		map->objcg = get_obj_cgroup_from_current();
398 }
399 
bpf_map_release_memcg(struct bpf_map * map)400 static void bpf_map_release_memcg(struct bpf_map *map)
401 {
402 	if (map->objcg)
403 		obj_cgroup_put(map->objcg);
404 }
405 
bpf_map_get_memcg(const struct bpf_map * map)406 static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
407 {
408 	if (map->objcg)
409 		return get_mem_cgroup_from_objcg(map->objcg);
410 
411 	return root_mem_cgroup;
412 }
413 
bpf_map_kmalloc_node(const struct bpf_map * map,size_t size,gfp_t flags,int node)414 void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
415 			   int node)
416 {
417 	struct mem_cgroup *memcg, *old_memcg;
418 	void *ptr;
419 
420 	memcg = bpf_map_get_memcg(map);
421 	old_memcg = set_active_memcg(memcg);
422 	ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
423 	set_active_memcg(old_memcg);
424 	mem_cgroup_put(memcg);
425 
426 	return ptr;
427 }
428 
bpf_map_kzalloc(const struct bpf_map * map,size_t size,gfp_t flags)429 void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
430 {
431 	struct mem_cgroup *memcg, *old_memcg;
432 	void *ptr;
433 
434 	memcg = bpf_map_get_memcg(map);
435 	old_memcg = set_active_memcg(memcg);
436 	ptr = kzalloc(size, flags | __GFP_ACCOUNT);
437 	set_active_memcg(old_memcg);
438 	mem_cgroup_put(memcg);
439 
440 	return ptr;
441 }
442 
bpf_map_kvcalloc(struct bpf_map * map,size_t n,size_t size,gfp_t flags)443 void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
444 		       gfp_t flags)
445 {
446 	struct mem_cgroup *memcg, *old_memcg;
447 	void *ptr;
448 
449 	memcg = bpf_map_get_memcg(map);
450 	old_memcg = set_active_memcg(memcg);
451 	ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
452 	set_active_memcg(old_memcg);
453 	mem_cgroup_put(memcg);
454 
455 	return ptr;
456 }
457 
bpf_map_alloc_percpu(const struct bpf_map * map,size_t size,size_t align,gfp_t flags)458 void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
459 				    size_t align, gfp_t flags)
460 {
461 	struct mem_cgroup *memcg, *old_memcg;
462 	void __percpu *ptr;
463 
464 	memcg = bpf_map_get_memcg(map);
465 	old_memcg = set_active_memcg(memcg);
466 	ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
467 	set_active_memcg(old_memcg);
468 	mem_cgroup_put(memcg);
469 
470 	return ptr;
471 }
472 
473 #else
bpf_map_save_memcg(struct bpf_map * map)474 static void bpf_map_save_memcg(struct bpf_map *map)
475 {
476 }
477 
bpf_map_release_memcg(struct bpf_map * map)478 static void bpf_map_release_memcg(struct bpf_map *map)
479 {
480 }
481 #endif
482 
bpf_map_alloc_pages(const struct bpf_map * map,gfp_t gfp,int nid,unsigned long nr_pages,struct page ** pages)483 int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid,
484 			unsigned long nr_pages, struct page **pages)
485 {
486 	unsigned long i, j;
487 	struct page *pg;
488 	int ret = 0;
489 #ifdef CONFIG_MEMCG_KMEM
490 	struct mem_cgroup *memcg, *old_memcg;
491 
492 	memcg = bpf_map_get_memcg(map);
493 	old_memcg = set_active_memcg(memcg);
494 #endif
495 	for (i = 0; i < nr_pages; i++) {
496 		pg = alloc_pages_node(nid, gfp | __GFP_ACCOUNT, 0);
497 
498 		if (pg) {
499 			pages[i] = pg;
500 			continue;
501 		}
502 		for (j = 0; j < i; j++)
503 			__free_page(pages[j]);
504 		ret = -ENOMEM;
505 		break;
506 	}
507 
508 #ifdef CONFIG_MEMCG_KMEM
509 	set_active_memcg(old_memcg);
510 	mem_cgroup_put(memcg);
511 #endif
512 	return ret;
513 }
514 
515 
btf_field_cmp(const void * a,const void * b)516 static int btf_field_cmp(const void *a, const void *b)
517 {
518 	const struct btf_field *f1 = a, *f2 = b;
519 
520 	if (f1->offset < f2->offset)
521 		return -1;
522 	else if (f1->offset > f2->offset)
523 		return 1;
524 	return 0;
525 }
526 
btf_record_find(const struct btf_record * rec,u32 offset,u32 field_mask)527 struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
528 				  u32 field_mask)
529 {
530 	struct btf_field *field;
531 
532 	if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
533 		return NULL;
534 	field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
535 	if (!field || !(field->type & field_mask))
536 		return NULL;
537 	return field;
538 }
539 
btf_record_free(struct btf_record * rec)540 void btf_record_free(struct btf_record *rec)
541 {
542 	int i;
543 
544 	if (IS_ERR_OR_NULL(rec))
545 		return;
546 	for (i = 0; i < rec->cnt; i++) {
547 		switch (rec->fields[i].type) {
548 		case BPF_KPTR_UNREF:
549 		case BPF_KPTR_REF:
550 		case BPF_KPTR_PERCPU:
551 			if (rec->fields[i].kptr.module)
552 				module_put(rec->fields[i].kptr.module);
553 			btf_put(rec->fields[i].kptr.btf);
554 			break;
555 		case BPF_LIST_HEAD:
556 		case BPF_LIST_NODE:
557 		case BPF_RB_ROOT:
558 		case BPF_RB_NODE:
559 		case BPF_SPIN_LOCK:
560 		case BPF_TIMER:
561 		case BPF_REFCOUNT:
562 		case BPF_WORKQUEUE:
563 			/* Nothing to release */
564 			break;
565 		default:
566 			WARN_ON_ONCE(1);
567 			continue;
568 		}
569 	}
570 	kfree(rec);
571 }
572 
bpf_map_free_record(struct bpf_map * map)573 void bpf_map_free_record(struct bpf_map *map)
574 {
575 	btf_record_free(map->record);
576 	map->record = NULL;
577 }
578 
btf_record_dup(const struct btf_record * rec)579 struct btf_record *btf_record_dup(const struct btf_record *rec)
580 {
581 	const struct btf_field *fields;
582 	struct btf_record *new_rec;
583 	int ret, size, i;
584 
585 	if (IS_ERR_OR_NULL(rec))
586 		return NULL;
587 	size = offsetof(struct btf_record, fields[rec->cnt]);
588 	new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
589 	if (!new_rec)
590 		return ERR_PTR(-ENOMEM);
591 	/* Do a deep copy of the btf_record */
592 	fields = rec->fields;
593 	new_rec->cnt = 0;
594 	for (i = 0; i < rec->cnt; i++) {
595 		switch (fields[i].type) {
596 		case BPF_KPTR_UNREF:
597 		case BPF_KPTR_REF:
598 		case BPF_KPTR_PERCPU:
599 			btf_get(fields[i].kptr.btf);
600 			if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
601 				ret = -ENXIO;
602 				goto free;
603 			}
604 			break;
605 		case BPF_LIST_HEAD:
606 		case BPF_LIST_NODE:
607 		case BPF_RB_ROOT:
608 		case BPF_RB_NODE:
609 		case BPF_SPIN_LOCK:
610 		case BPF_TIMER:
611 		case BPF_REFCOUNT:
612 		case BPF_WORKQUEUE:
613 			/* Nothing to acquire */
614 			break;
615 		default:
616 			ret = -EFAULT;
617 			WARN_ON_ONCE(1);
618 			goto free;
619 		}
620 		new_rec->cnt++;
621 	}
622 	return new_rec;
623 free:
624 	btf_record_free(new_rec);
625 	return ERR_PTR(ret);
626 }
627 
btf_record_equal(const struct btf_record * rec_a,const struct btf_record * rec_b)628 bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
629 {
630 	bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
631 	int size;
632 
633 	if (!a_has_fields && !b_has_fields)
634 		return true;
635 	if (a_has_fields != b_has_fields)
636 		return false;
637 	if (rec_a->cnt != rec_b->cnt)
638 		return false;
639 	size = offsetof(struct btf_record, fields[rec_a->cnt]);
640 	/* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
641 	 * members are zeroed out. So memcmp is safe to do without worrying
642 	 * about padding/unused fields.
643 	 *
644 	 * While spin_lock, timer, and kptr have no relation to map BTF,
645 	 * list_head metadata is specific to map BTF, the btf and value_rec
646 	 * members in particular. btf is the map BTF, while value_rec points to
647 	 * btf_record in that map BTF.
648 	 *
649 	 * So while by default, we don't rely on the map BTF (which the records
650 	 * were parsed from) matching for both records, which is not backwards
651 	 * compatible, in case list_head is part of it, we implicitly rely on
652 	 * that by way of depending on memcmp succeeding for it.
653 	 */
654 	return !memcmp(rec_a, rec_b, size);
655 }
656 
bpf_obj_free_timer(const struct btf_record * rec,void * obj)657 void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
658 {
659 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
660 		return;
661 	bpf_timer_cancel_and_free(obj + rec->timer_off);
662 }
663 
bpf_obj_free_workqueue(const struct btf_record * rec,void * obj)664 void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
665 {
666 	if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
667 		return;
668 	bpf_wq_cancel_and_free(obj + rec->wq_off);
669 }
670 
bpf_obj_free_fields(const struct btf_record * rec,void * obj)671 void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
672 {
673 	const struct btf_field *fields;
674 	int i;
675 
676 	if (IS_ERR_OR_NULL(rec))
677 		return;
678 	fields = rec->fields;
679 	for (i = 0; i < rec->cnt; i++) {
680 		struct btf_struct_meta *pointee_struct_meta;
681 		const struct btf_field *field = &fields[i];
682 		void *field_ptr = obj + field->offset;
683 		void *xchgd_field;
684 
685 		switch (fields[i].type) {
686 		case BPF_SPIN_LOCK:
687 			break;
688 		case BPF_TIMER:
689 			bpf_timer_cancel_and_free(field_ptr);
690 			break;
691 		case BPF_WORKQUEUE:
692 			bpf_wq_cancel_and_free(field_ptr);
693 			break;
694 		case BPF_KPTR_UNREF:
695 			WRITE_ONCE(*(u64 *)field_ptr, 0);
696 			break;
697 		case BPF_KPTR_REF:
698 		case BPF_KPTR_PERCPU:
699 			xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
700 			if (!xchgd_field)
701 				break;
702 
703 			if (!btf_is_kernel(field->kptr.btf)) {
704 				pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
705 									   field->kptr.btf_id);
706 				migrate_disable();
707 				__bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
708 								 pointee_struct_meta->record : NULL,
709 								 fields[i].type == BPF_KPTR_PERCPU);
710 				migrate_enable();
711 			} else {
712 				field->kptr.dtor(xchgd_field);
713 			}
714 			break;
715 		case BPF_LIST_HEAD:
716 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
717 				continue;
718 			bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
719 			break;
720 		case BPF_RB_ROOT:
721 			if (WARN_ON_ONCE(rec->spin_lock_off < 0))
722 				continue;
723 			bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
724 			break;
725 		case BPF_LIST_NODE:
726 		case BPF_RB_NODE:
727 		case BPF_REFCOUNT:
728 			break;
729 		default:
730 			WARN_ON_ONCE(1);
731 			continue;
732 		}
733 	}
734 }
735 
736 /* called from workqueue */
bpf_map_free_deferred(struct work_struct * work)737 static void bpf_map_free_deferred(struct work_struct *work)
738 {
739 	struct bpf_map *map = container_of(work, struct bpf_map, work);
740 	struct btf_record *rec = map->record;
741 	struct btf *btf = map->btf;
742 
743 	security_bpf_map_free(map);
744 	bpf_map_release_memcg(map);
745 	/* implementation dependent freeing */
746 	map->ops->map_free(map);
747 	/* Delay freeing of btf_record for maps, as map_free
748 	 * callback usually needs access to them. It is better to do it here
749 	 * than require each callback to do the free itself manually.
750 	 *
751 	 * Note that the btf_record stashed in map->inner_map_meta->record was
752 	 * already freed using the map_free callback for map in map case which
753 	 * eventually calls bpf_map_free_meta, since inner_map_meta is only a
754 	 * template bpf_map struct used during verification.
755 	 */
756 	btf_record_free(rec);
757 	/* Delay freeing of btf for maps, as map_free callback may need
758 	 * struct_meta info which will be freed with btf_put().
759 	 */
760 	btf_put(btf);
761 }
762 
bpf_map_put_uref(struct bpf_map * map)763 static void bpf_map_put_uref(struct bpf_map *map)
764 {
765 	if (atomic64_dec_and_test(&map->usercnt)) {
766 		if (map->ops->map_release_uref)
767 			map->ops->map_release_uref(map);
768 	}
769 }
770 
bpf_map_free_in_work(struct bpf_map * map)771 static void bpf_map_free_in_work(struct bpf_map *map)
772 {
773 	INIT_WORK(&map->work, bpf_map_free_deferred);
774 	/* Avoid spawning kworkers, since they all might contend
775 	 * for the same mutex like slab_mutex.
776 	 */
777 	queue_work(system_unbound_wq, &map->work);
778 }
779 
bpf_map_free_rcu_gp(struct rcu_head * rcu)780 static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
781 {
782 	bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
783 }
784 
bpf_map_free_mult_rcu_gp(struct rcu_head * rcu)785 static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
786 {
787 	if (rcu_trace_implies_rcu_gp())
788 		bpf_map_free_rcu_gp(rcu);
789 	else
790 		call_rcu(rcu, bpf_map_free_rcu_gp);
791 }
792 
793 /* decrement map refcnt and schedule it for freeing via workqueue
794  * (underlying map implementation ops->map_free() might sleep)
795  */
bpf_map_put(struct bpf_map * map)796 void bpf_map_put(struct bpf_map *map)
797 {
798 	if (atomic64_dec_and_test(&map->refcnt)) {
799 		/* bpf_map_free_id() must be called first */
800 		bpf_map_free_id(map);
801 
802 		WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
803 		if (READ_ONCE(map->free_after_mult_rcu_gp))
804 			call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
805 		else if (READ_ONCE(map->free_after_rcu_gp))
806 			call_rcu(&map->rcu, bpf_map_free_rcu_gp);
807 		else
808 			bpf_map_free_in_work(map);
809 	}
810 }
811 EXPORT_SYMBOL_GPL(bpf_map_put);
812 
bpf_map_put_with_uref(struct bpf_map * map)813 void bpf_map_put_with_uref(struct bpf_map *map)
814 {
815 	bpf_map_put_uref(map);
816 	bpf_map_put(map);
817 }
818 
bpf_map_release(struct inode * inode,struct file * filp)819 static int bpf_map_release(struct inode *inode, struct file *filp)
820 {
821 	struct bpf_map *map = filp->private_data;
822 
823 	if (map->ops->map_release)
824 		map->ops->map_release(map, filp);
825 
826 	bpf_map_put_with_uref(map);
827 	return 0;
828 }
829 
map_get_sys_perms(struct bpf_map * map,struct fd f)830 static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
831 {
832 	fmode_t mode = f.file->f_mode;
833 
834 	/* Our file permissions may have been overridden by global
835 	 * map permissions facing syscall side.
836 	 */
837 	if (READ_ONCE(map->frozen))
838 		mode &= ~FMODE_CAN_WRITE;
839 	return mode;
840 }
841 
842 #ifdef CONFIG_PROC_FS
843 /* Show the memory usage of a bpf map */
bpf_map_memory_usage(const struct bpf_map * map)844 static u64 bpf_map_memory_usage(const struct bpf_map *map)
845 {
846 	return map->ops->map_mem_usage(map);
847 }
848 
bpf_map_show_fdinfo(struct seq_file * m,struct file * filp)849 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
850 {
851 	struct bpf_map *map = filp->private_data;
852 	u32 type = 0, jited = 0;
853 
854 	if (map_type_contains_progs(map)) {
855 		spin_lock(&map->owner.lock);
856 		type  = map->owner.type;
857 		jited = map->owner.jited;
858 		spin_unlock(&map->owner.lock);
859 	}
860 
861 	seq_printf(m,
862 		   "map_type:\t%u\n"
863 		   "key_size:\t%u\n"
864 		   "value_size:\t%u\n"
865 		   "max_entries:\t%u\n"
866 		   "map_flags:\t%#x\n"
867 		   "map_extra:\t%#llx\n"
868 		   "memlock:\t%llu\n"
869 		   "map_id:\t%u\n"
870 		   "frozen:\t%u\n",
871 		   map->map_type,
872 		   map->key_size,
873 		   map->value_size,
874 		   map->max_entries,
875 		   map->map_flags,
876 		   (unsigned long long)map->map_extra,
877 		   bpf_map_memory_usage(map),
878 		   map->id,
879 		   READ_ONCE(map->frozen));
880 	if (type) {
881 		seq_printf(m, "owner_prog_type:\t%u\n", type);
882 		seq_printf(m, "owner_jited:\t%u\n", jited);
883 	}
884 }
885 #endif
886 
bpf_dummy_read(struct file * filp,char __user * buf,size_t siz,loff_t * ppos)887 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
888 			      loff_t *ppos)
889 {
890 	/* We need this handler such that alloc_file() enables
891 	 * f_mode with FMODE_CAN_READ.
892 	 */
893 	return -EINVAL;
894 }
895 
bpf_dummy_write(struct file * filp,const char __user * buf,size_t siz,loff_t * ppos)896 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
897 			       size_t siz, loff_t *ppos)
898 {
899 	/* We need this handler such that alloc_file() enables
900 	 * f_mode with FMODE_CAN_WRITE.
901 	 */
902 	return -EINVAL;
903 }
904 
905 /* called for any extra memory-mapped regions (except initial) */
bpf_map_mmap_open(struct vm_area_struct * vma)906 static void bpf_map_mmap_open(struct vm_area_struct *vma)
907 {
908 	struct bpf_map *map = vma->vm_file->private_data;
909 
910 	if (vma->vm_flags & VM_MAYWRITE)
911 		bpf_map_write_active_inc(map);
912 }
913 
914 /* called for all unmapped memory region (including initial) */
bpf_map_mmap_close(struct vm_area_struct * vma)915 static void bpf_map_mmap_close(struct vm_area_struct *vma)
916 {
917 	struct bpf_map *map = vma->vm_file->private_data;
918 
919 	if (vma->vm_flags & VM_MAYWRITE)
920 		bpf_map_write_active_dec(map);
921 }
922 
923 static const struct vm_operations_struct bpf_map_default_vmops = {
924 	.open		= bpf_map_mmap_open,
925 	.close		= bpf_map_mmap_close,
926 };
927 
bpf_map_mmap(struct file * filp,struct vm_area_struct * vma)928 static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
929 {
930 	struct bpf_map *map = filp->private_data;
931 	int err;
932 
933 	if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
934 		return -ENOTSUPP;
935 
936 	if (!(vma->vm_flags & VM_SHARED))
937 		return -EINVAL;
938 
939 	mutex_lock(&map->freeze_mutex);
940 
941 	if (vma->vm_flags & VM_WRITE) {
942 		if (map->frozen) {
943 			err = -EPERM;
944 			goto out;
945 		}
946 		/* map is meant to be read-only, so do not allow mapping as
947 		 * writable, because it's possible to leak a writable page
948 		 * reference and allows user-space to still modify it after
949 		 * freezing, while verifier will assume contents do not change
950 		 */
951 		if (map->map_flags & BPF_F_RDONLY_PROG) {
952 			err = -EACCES;
953 			goto out;
954 		}
955 	}
956 
957 	/* set default open/close callbacks */
958 	vma->vm_ops = &bpf_map_default_vmops;
959 	vma->vm_private_data = map;
960 	vm_flags_clear(vma, VM_MAYEXEC);
961 	if (!(vma->vm_flags & VM_WRITE))
962 		/* disallow re-mapping with PROT_WRITE */
963 		vm_flags_clear(vma, VM_MAYWRITE);
964 
965 	err = map->ops->map_mmap(map, vma);
966 	if (err)
967 		goto out;
968 
969 	if (vma->vm_flags & VM_MAYWRITE)
970 		bpf_map_write_active_inc(map);
971 out:
972 	mutex_unlock(&map->freeze_mutex);
973 	return err;
974 }
975 
bpf_map_poll(struct file * filp,struct poll_table_struct * pts)976 static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
977 {
978 	struct bpf_map *map = filp->private_data;
979 
980 	if (map->ops->map_poll)
981 		return map->ops->map_poll(map, filp, pts);
982 
983 	return EPOLLERR;
984 }
985 
bpf_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)986 static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
987 					   unsigned long len, unsigned long pgoff,
988 					   unsigned long flags)
989 {
990 	struct bpf_map *map = filp->private_data;
991 
992 	if (map->ops->map_get_unmapped_area)
993 		return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
994 #ifdef CONFIG_MMU
995 	return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
996 #else
997 	return addr;
998 #endif
999 }
1000 
1001 const struct file_operations bpf_map_fops = {
1002 #ifdef CONFIG_PROC_FS
1003 	.show_fdinfo	= bpf_map_show_fdinfo,
1004 #endif
1005 	.release	= bpf_map_release,
1006 	.read		= bpf_dummy_read,
1007 	.write		= bpf_dummy_write,
1008 	.mmap		= bpf_map_mmap,
1009 	.poll		= bpf_map_poll,
1010 	.get_unmapped_area = bpf_get_unmapped_area,
1011 };
1012 
bpf_map_new_fd(struct bpf_map * map,int flags)1013 int bpf_map_new_fd(struct bpf_map *map, int flags)
1014 {
1015 	int ret;
1016 
1017 	ret = security_bpf_map(map, OPEN_FMODE(flags));
1018 	if (ret < 0)
1019 		return ret;
1020 
1021 	return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
1022 				flags | O_CLOEXEC);
1023 }
1024 
bpf_get_file_flag(int flags)1025 int bpf_get_file_flag(int flags)
1026 {
1027 	if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
1028 		return -EINVAL;
1029 	if (flags & BPF_F_RDONLY)
1030 		return O_RDONLY;
1031 	if (flags & BPF_F_WRONLY)
1032 		return O_WRONLY;
1033 	return O_RDWR;
1034 }
1035 
1036 /* helper macro to check that unused fields 'union bpf_attr' are zero */
1037 #define CHECK_ATTR(CMD) \
1038 	memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
1039 		   sizeof(attr->CMD##_LAST_FIELD), 0, \
1040 		   sizeof(*attr) - \
1041 		   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
1042 		   sizeof(attr->CMD##_LAST_FIELD)) != NULL
1043 
1044 /* dst and src must have at least "size" number of bytes.
1045  * Return strlen on success and < 0 on error.
1046  */
bpf_obj_name_cpy(char * dst,const char * src,unsigned int size)1047 int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
1048 {
1049 	const char *end = src + size;
1050 	const char *orig_src = src;
1051 
1052 	memset(dst, 0, size);
1053 	/* Copy all isalnum(), '_' and '.' chars. */
1054 	while (src < end && *src) {
1055 		if (!isalnum(*src) &&
1056 		    *src != '_' && *src != '.')
1057 			return -EINVAL;
1058 		*dst++ = *src++;
1059 	}
1060 
1061 	/* No '\0' found in "size" number of bytes */
1062 	if (src == end)
1063 		return -EINVAL;
1064 
1065 	return src - orig_src;
1066 }
1067 
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)1068 int map_check_no_btf(const struct bpf_map *map,
1069 		     const struct btf *btf,
1070 		     const struct btf_type *key_type,
1071 		     const struct btf_type *value_type)
1072 {
1073 	return -ENOTSUPP;
1074 }
1075 
map_check_btf(struct bpf_map * map,struct bpf_token * token,const struct btf * btf,u32 btf_key_id,u32 btf_value_id)1076 static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
1077 			 const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
1078 {
1079 	const struct btf_type *key_type, *value_type;
1080 	u32 key_size, value_size;
1081 	int ret = 0;
1082 
1083 	/* Some maps allow key to be unspecified. */
1084 	if (btf_key_id) {
1085 		key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
1086 		if (!key_type || key_size != map->key_size)
1087 			return -EINVAL;
1088 	} else {
1089 		key_type = btf_type_by_id(btf, 0);
1090 		if (!map->ops->map_check_btf)
1091 			return -EINVAL;
1092 	}
1093 
1094 	value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
1095 	if (!value_type || value_size != map->value_size)
1096 		return -EINVAL;
1097 
1098 	map->record = btf_parse_fields(btf, value_type,
1099 				       BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
1100 				       BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE,
1101 				       map->value_size);
1102 	if (!IS_ERR_OR_NULL(map->record)) {
1103 		int i;
1104 
1105 		if (!bpf_token_capable(token, CAP_BPF)) {
1106 			ret = -EPERM;
1107 			goto free_map_tab;
1108 		}
1109 		if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
1110 			ret = -EACCES;
1111 			goto free_map_tab;
1112 		}
1113 		for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
1114 			switch (map->record->field_mask & (1 << i)) {
1115 			case 0:
1116 				continue;
1117 			case BPF_SPIN_LOCK:
1118 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1119 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1120 				    map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
1121 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1122 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1123 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1124 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1125 					ret = -EOPNOTSUPP;
1126 					goto free_map_tab;
1127 				}
1128 				break;
1129 			case BPF_TIMER:
1130 			case BPF_WORKQUEUE:
1131 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1132 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1133 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1134 					ret = -EOPNOTSUPP;
1135 					goto free_map_tab;
1136 				}
1137 				break;
1138 			case BPF_KPTR_UNREF:
1139 			case BPF_KPTR_REF:
1140 			case BPF_KPTR_PERCPU:
1141 			case BPF_REFCOUNT:
1142 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1143 				    map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
1144 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1145 				    map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
1146 				    map->map_type != BPF_MAP_TYPE_ARRAY &&
1147 				    map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
1148 				    map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
1149 				    map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
1150 				    map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
1151 				    map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
1152 					ret = -EOPNOTSUPP;
1153 					goto free_map_tab;
1154 				}
1155 				break;
1156 			case BPF_LIST_HEAD:
1157 			case BPF_RB_ROOT:
1158 				if (map->map_type != BPF_MAP_TYPE_HASH &&
1159 				    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
1160 				    map->map_type != BPF_MAP_TYPE_ARRAY) {
1161 					ret = -EOPNOTSUPP;
1162 					goto free_map_tab;
1163 				}
1164 				break;
1165 			default:
1166 				/* Fail if map_type checks are missing for a field type */
1167 				ret = -EOPNOTSUPP;
1168 				goto free_map_tab;
1169 			}
1170 		}
1171 	}
1172 
1173 	ret = btf_check_and_fixup_fields(btf, map->record);
1174 	if (ret < 0)
1175 		goto free_map_tab;
1176 
1177 	if (map->ops->map_check_btf) {
1178 		ret = map->ops->map_check_btf(map, btf, key_type, value_type);
1179 		if (ret < 0)
1180 			goto free_map_tab;
1181 	}
1182 
1183 	return ret;
1184 free_map_tab:
1185 	bpf_map_free_record(map);
1186 	return ret;
1187 }
1188 
bpf_net_capable(void)1189 static bool bpf_net_capable(void)
1190 {
1191 	return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
1192 }
1193 
1194 #define BPF_MAP_CREATE_LAST_FIELD map_token_fd
1195 /* called via syscall */
map_create(union bpf_attr * attr)1196 static int map_create(union bpf_attr *attr)
1197 {
1198 	const struct bpf_map_ops *ops;
1199 	struct bpf_token *token = NULL;
1200 	int numa_node = bpf_map_attr_numa_node(attr);
1201 	u32 map_type = attr->map_type;
1202 	struct bpf_map *map;
1203 	bool token_flag;
1204 	int f_flags;
1205 	int err;
1206 
1207 	err = CHECK_ATTR(BPF_MAP_CREATE);
1208 	if (err)
1209 		return -EINVAL;
1210 
1211 	/* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
1212 	 * to avoid per-map type checks tripping on unknown flag
1213 	 */
1214 	token_flag = attr->map_flags & BPF_F_TOKEN_FD;
1215 	attr->map_flags &= ~BPF_F_TOKEN_FD;
1216 
1217 	if (attr->btf_vmlinux_value_type_id) {
1218 		if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
1219 		    attr->btf_key_type_id || attr->btf_value_type_id)
1220 			return -EINVAL;
1221 	} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
1222 		return -EINVAL;
1223 	}
1224 
1225 	if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
1226 	    attr->map_type != BPF_MAP_TYPE_ARENA &&
1227 	    attr->map_extra != 0)
1228 		return -EINVAL;
1229 
1230 	f_flags = bpf_get_file_flag(attr->map_flags);
1231 	if (f_flags < 0)
1232 		return f_flags;
1233 
1234 	if (numa_node != NUMA_NO_NODE &&
1235 	    ((unsigned int)numa_node >= nr_node_ids ||
1236 	     !node_online(numa_node)))
1237 		return -EINVAL;
1238 
1239 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
1240 	map_type = attr->map_type;
1241 	if (map_type >= ARRAY_SIZE(bpf_map_types))
1242 		return -EINVAL;
1243 	map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
1244 	ops = bpf_map_types[map_type];
1245 	if (!ops)
1246 		return -EINVAL;
1247 
1248 	if (ops->map_alloc_check) {
1249 		err = ops->map_alloc_check(attr);
1250 		if (err)
1251 			return err;
1252 	}
1253 	if (attr->map_ifindex)
1254 		ops = &bpf_map_offload_ops;
1255 	if (!ops->map_mem_usage)
1256 		return -EINVAL;
1257 
1258 	if (token_flag) {
1259 		token = bpf_token_get_from_fd(attr->map_token_fd);
1260 		if (IS_ERR(token))
1261 			return PTR_ERR(token);
1262 
1263 		/* if current token doesn't grant map creation permissions,
1264 		 * then we can't use this token, so ignore it and rely on
1265 		 * system-wide capabilities checks
1266 		 */
1267 		if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
1268 		    !bpf_token_allow_map_type(token, attr->map_type)) {
1269 			bpf_token_put(token);
1270 			token = NULL;
1271 		}
1272 	}
1273 
1274 	err = -EPERM;
1275 
1276 	/* Intent here is for unprivileged_bpf_disabled to block BPF map
1277 	 * creation for unprivileged users; other actions depend
1278 	 * on fd availability and access to bpffs, so are dependent on
1279 	 * object creation success. Even with unprivileged BPF disabled,
1280 	 * capability checks are still carried out.
1281 	 */
1282 	if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
1283 		goto put_token;
1284 
1285 	/* check privileged map type permissions */
1286 	switch (map_type) {
1287 	case BPF_MAP_TYPE_ARRAY:
1288 	case BPF_MAP_TYPE_PERCPU_ARRAY:
1289 	case BPF_MAP_TYPE_PROG_ARRAY:
1290 	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
1291 	case BPF_MAP_TYPE_CGROUP_ARRAY:
1292 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
1293 	case BPF_MAP_TYPE_HASH:
1294 	case BPF_MAP_TYPE_PERCPU_HASH:
1295 	case BPF_MAP_TYPE_HASH_OF_MAPS:
1296 	case BPF_MAP_TYPE_RINGBUF:
1297 	case BPF_MAP_TYPE_USER_RINGBUF:
1298 	case BPF_MAP_TYPE_CGROUP_STORAGE:
1299 	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
1300 		/* unprivileged */
1301 		break;
1302 	case BPF_MAP_TYPE_SK_STORAGE:
1303 	case BPF_MAP_TYPE_INODE_STORAGE:
1304 	case BPF_MAP_TYPE_TASK_STORAGE:
1305 	case BPF_MAP_TYPE_CGRP_STORAGE:
1306 	case BPF_MAP_TYPE_BLOOM_FILTER:
1307 	case BPF_MAP_TYPE_LPM_TRIE:
1308 	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
1309 	case BPF_MAP_TYPE_STACK_TRACE:
1310 	case BPF_MAP_TYPE_QUEUE:
1311 	case BPF_MAP_TYPE_STACK:
1312 	case BPF_MAP_TYPE_LRU_HASH:
1313 	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
1314 	case BPF_MAP_TYPE_STRUCT_OPS:
1315 	case BPF_MAP_TYPE_CPUMAP:
1316 	case BPF_MAP_TYPE_ARENA:
1317 		if (!bpf_token_capable(token, CAP_BPF))
1318 			goto put_token;
1319 		break;
1320 	case BPF_MAP_TYPE_SOCKMAP:
1321 	case BPF_MAP_TYPE_SOCKHASH:
1322 	case BPF_MAP_TYPE_DEVMAP:
1323 	case BPF_MAP_TYPE_DEVMAP_HASH:
1324 	case BPF_MAP_TYPE_XSKMAP:
1325 		if (!bpf_token_capable(token, CAP_NET_ADMIN))
1326 			goto put_token;
1327 		break;
1328 	default:
1329 		WARN(1, "unsupported map type %d", map_type);
1330 		goto put_token;
1331 	}
1332 
1333 	map = ops->map_alloc(attr);
1334 	if (IS_ERR(map)) {
1335 		err = PTR_ERR(map);
1336 		goto put_token;
1337 	}
1338 	map->ops = ops;
1339 	map->map_type = map_type;
1340 
1341 	err = bpf_obj_name_cpy(map->name, attr->map_name,
1342 			       sizeof(attr->map_name));
1343 	if (err < 0)
1344 		goto free_map;
1345 
1346 	atomic64_set(&map->refcnt, 1);
1347 	atomic64_set(&map->usercnt, 1);
1348 	mutex_init(&map->freeze_mutex);
1349 	spin_lock_init(&map->owner.lock);
1350 
1351 	if (attr->btf_key_type_id || attr->btf_value_type_id ||
1352 	    /* Even the map's value is a kernel's struct,
1353 	     * the bpf_prog.o must have BTF to begin with
1354 	     * to figure out the corresponding kernel's
1355 	     * counter part.  Thus, attr->btf_fd has
1356 	     * to be valid also.
1357 	     */
1358 	    attr->btf_vmlinux_value_type_id) {
1359 		struct btf *btf;
1360 
1361 		btf = btf_get_by_fd(attr->btf_fd);
1362 		if (IS_ERR(btf)) {
1363 			err = PTR_ERR(btf);
1364 			goto free_map;
1365 		}
1366 		if (btf_is_kernel(btf)) {
1367 			btf_put(btf);
1368 			err = -EACCES;
1369 			goto free_map;
1370 		}
1371 		map->btf = btf;
1372 
1373 		if (attr->btf_value_type_id) {
1374 			err = map_check_btf(map, token, btf, attr->btf_key_type_id,
1375 					    attr->btf_value_type_id);
1376 			if (err)
1377 				goto free_map;
1378 		}
1379 
1380 		map->btf_key_type_id = attr->btf_key_type_id;
1381 		map->btf_value_type_id = attr->btf_value_type_id;
1382 		map->btf_vmlinux_value_type_id =
1383 			attr->btf_vmlinux_value_type_id;
1384 	}
1385 
1386 	err = security_bpf_map_create(map, attr, token);
1387 	if (err)
1388 		goto free_map_sec;
1389 
1390 	err = bpf_map_alloc_id(map);
1391 	if (err)
1392 		goto free_map_sec;
1393 
1394 	bpf_map_save_memcg(map);
1395 	bpf_token_put(token);
1396 
1397 	err = bpf_map_new_fd(map, f_flags);
1398 	if (err < 0) {
1399 		/* failed to allocate fd.
1400 		 * bpf_map_put_with_uref() is needed because the above
1401 		 * bpf_map_alloc_id() has published the map
1402 		 * to the userspace and the userspace may
1403 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
1404 		 */
1405 		bpf_map_put_with_uref(map);
1406 		return err;
1407 	}
1408 
1409 	return err;
1410 
1411 free_map_sec:
1412 	security_bpf_map_free(map);
1413 free_map:
1414 	btf_put(map->btf);
1415 	map->ops->map_free(map);
1416 put_token:
1417 	bpf_token_put(token);
1418 	return err;
1419 }
1420 
1421 /* if error is returned, fd is released.
1422  * On success caller should complete fd access with matching fdput()
1423  */
__bpf_map_get(struct fd f)1424 struct bpf_map *__bpf_map_get(struct fd f)
1425 {
1426 	if (!f.file)
1427 		return ERR_PTR(-EBADF);
1428 	if (f.file->f_op != &bpf_map_fops) {
1429 		fdput(f);
1430 		return ERR_PTR(-EINVAL);
1431 	}
1432 
1433 	return f.file->private_data;
1434 }
1435 
bpf_map_inc(struct bpf_map * map)1436 void bpf_map_inc(struct bpf_map *map)
1437 {
1438 	atomic64_inc(&map->refcnt);
1439 }
1440 EXPORT_SYMBOL_GPL(bpf_map_inc);
1441 
bpf_map_inc_with_uref(struct bpf_map * map)1442 void bpf_map_inc_with_uref(struct bpf_map *map)
1443 {
1444 	atomic64_inc(&map->refcnt);
1445 	atomic64_inc(&map->usercnt);
1446 }
1447 EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
1448 
bpf_map_get(u32 ufd)1449 struct bpf_map *bpf_map_get(u32 ufd)
1450 {
1451 	struct fd f = fdget(ufd);
1452 	struct bpf_map *map;
1453 
1454 	map = __bpf_map_get(f);
1455 	if (IS_ERR(map))
1456 		return map;
1457 
1458 	bpf_map_inc(map);
1459 	fdput(f);
1460 
1461 	return map;
1462 }
1463 EXPORT_SYMBOL(bpf_map_get);
1464 
bpf_map_get_with_uref(u32 ufd)1465 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
1466 {
1467 	struct fd f = fdget(ufd);
1468 	struct bpf_map *map;
1469 
1470 	map = __bpf_map_get(f);
1471 	if (IS_ERR(map))
1472 		return map;
1473 
1474 	bpf_map_inc_with_uref(map);
1475 	fdput(f);
1476 
1477 	return map;
1478 }
1479 
1480 /* map_idr_lock should have been held or the map should have been
1481  * protected by rcu read lock.
1482  */
__bpf_map_inc_not_zero(struct bpf_map * map,bool uref)1483 struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
1484 {
1485 	int refold;
1486 
1487 	refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
1488 	if (!refold)
1489 		return ERR_PTR(-ENOENT);
1490 	if (uref)
1491 		atomic64_inc(&map->usercnt);
1492 
1493 	return map;
1494 }
1495 
bpf_map_inc_not_zero(struct bpf_map * map)1496 struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
1497 {
1498 	spin_lock_bh(&map_idr_lock);
1499 	map = __bpf_map_inc_not_zero(map, false);
1500 	spin_unlock_bh(&map_idr_lock);
1501 
1502 	return map;
1503 }
1504 EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
1505 
bpf_stackmap_copy(struct bpf_map * map,void * key,void * value)1506 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
1507 {
1508 	return -ENOTSUPP;
1509 }
1510 
__bpf_copy_key(void __user * ukey,u64 key_size)1511 static void *__bpf_copy_key(void __user *ukey, u64 key_size)
1512 {
1513 	if (key_size)
1514 		return vmemdup_user(ukey, key_size);
1515 
1516 	if (ukey)
1517 		return ERR_PTR(-EINVAL);
1518 
1519 	return NULL;
1520 }
1521 
___bpf_copy_key(bpfptr_t ukey,u64 key_size)1522 static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
1523 {
1524 	if (key_size)
1525 		return kvmemdup_bpfptr(ukey, key_size);
1526 
1527 	if (!bpfptr_is_null(ukey))
1528 		return ERR_PTR(-EINVAL);
1529 
1530 	return NULL;
1531 }
1532 
1533 /* last field in 'union bpf_attr' used by this command */
1534 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
1535 
map_lookup_elem(union bpf_attr * attr)1536 static int map_lookup_elem(union bpf_attr *attr)
1537 {
1538 	void __user *ukey = u64_to_user_ptr(attr->key);
1539 	void __user *uvalue = u64_to_user_ptr(attr->value);
1540 	int ufd = attr->map_fd;
1541 	struct bpf_map *map;
1542 	void *key, *value;
1543 	u32 value_size;
1544 	struct fd f;
1545 	int err;
1546 
1547 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
1548 		return -EINVAL;
1549 
1550 	if (attr->flags & ~BPF_F_LOCK)
1551 		return -EINVAL;
1552 
1553 	f = fdget(ufd);
1554 	map = __bpf_map_get(f);
1555 	if (IS_ERR(map))
1556 		return PTR_ERR(map);
1557 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1558 		err = -EPERM;
1559 		goto err_put;
1560 	}
1561 
1562 	if ((attr->flags & BPF_F_LOCK) &&
1563 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1564 		err = -EINVAL;
1565 		goto err_put;
1566 	}
1567 
1568 	key = __bpf_copy_key(ukey, map->key_size);
1569 	if (IS_ERR(key)) {
1570 		err = PTR_ERR(key);
1571 		goto err_put;
1572 	}
1573 
1574 	value_size = bpf_map_value_size(map);
1575 
1576 	err = -ENOMEM;
1577 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1578 	if (!value)
1579 		goto free_key;
1580 
1581 	if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
1582 		if (copy_from_user(value, uvalue, value_size))
1583 			err = -EFAULT;
1584 		else
1585 			err = bpf_map_copy_value(map, key, value, attr->flags);
1586 		goto free_value;
1587 	}
1588 
1589 	err = bpf_map_copy_value(map, key, value, attr->flags);
1590 	if (err)
1591 		goto free_value;
1592 
1593 	err = -EFAULT;
1594 	if (copy_to_user(uvalue, value, value_size) != 0)
1595 		goto free_value;
1596 
1597 	err = 0;
1598 
1599 free_value:
1600 	kvfree(value);
1601 free_key:
1602 	kvfree(key);
1603 err_put:
1604 	fdput(f);
1605 	return err;
1606 }
1607 
1608 
1609 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
1610 
map_update_elem(union bpf_attr * attr,bpfptr_t uattr)1611 static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
1612 {
1613 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1614 	bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
1615 	int ufd = attr->map_fd;
1616 	struct bpf_map *map;
1617 	void *key, *value;
1618 	u32 value_size;
1619 	struct fd f;
1620 	int err;
1621 
1622 	if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
1623 		return -EINVAL;
1624 
1625 	f = fdget(ufd);
1626 	map = __bpf_map_get(f);
1627 	if (IS_ERR(map))
1628 		return PTR_ERR(map);
1629 	bpf_map_write_active_inc(map);
1630 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1631 		err = -EPERM;
1632 		goto err_put;
1633 	}
1634 
1635 	if ((attr->flags & BPF_F_LOCK) &&
1636 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1637 		err = -EINVAL;
1638 		goto err_put;
1639 	}
1640 
1641 	key = ___bpf_copy_key(ukey, map->key_size);
1642 	if (IS_ERR(key)) {
1643 		err = PTR_ERR(key);
1644 		goto err_put;
1645 	}
1646 
1647 	value_size = bpf_map_value_size(map);
1648 	value = kvmemdup_bpfptr(uvalue, value_size);
1649 	if (IS_ERR(value)) {
1650 		err = PTR_ERR(value);
1651 		goto free_key;
1652 	}
1653 
1654 	err = bpf_map_update_value(map, f.file, key, value, attr->flags);
1655 	if (!err)
1656 		maybe_wait_bpf_programs(map);
1657 
1658 	kvfree(value);
1659 free_key:
1660 	kvfree(key);
1661 err_put:
1662 	bpf_map_write_active_dec(map);
1663 	fdput(f);
1664 	return err;
1665 }
1666 
1667 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
1668 
map_delete_elem(union bpf_attr * attr,bpfptr_t uattr)1669 static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
1670 {
1671 	bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
1672 	int ufd = attr->map_fd;
1673 	struct bpf_map *map;
1674 	struct fd f;
1675 	void *key;
1676 	int err;
1677 
1678 	if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
1679 		return -EINVAL;
1680 
1681 	f = fdget(ufd);
1682 	map = __bpf_map_get(f);
1683 	if (IS_ERR(map))
1684 		return PTR_ERR(map);
1685 	bpf_map_write_active_inc(map);
1686 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
1687 		err = -EPERM;
1688 		goto err_put;
1689 	}
1690 
1691 	key = ___bpf_copy_key(ukey, map->key_size);
1692 	if (IS_ERR(key)) {
1693 		err = PTR_ERR(key);
1694 		goto err_put;
1695 	}
1696 
1697 	if (bpf_map_is_offloaded(map)) {
1698 		err = bpf_map_offload_delete_elem(map, key);
1699 		goto out;
1700 	} else if (IS_FD_PROG_ARRAY(map) ||
1701 		   map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
1702 		/* These maps require sleepable context */
1703 		err = map->ops->map_delete_elem(map, key);
1704 		goto out;
1705 	}
1706 
1707 	bpf_disable_instrumentation();
1708 	rcu_read_lock();
1709 	err = map->ops->map_delete_elem(map, key);
1710 	rcu_read_unlock();
1711 	bpf_enable_instrumentation();
1712 	if (!err)
1713 		maybe_wait_bpf_programs(map);
1714 out:
1715 	kvfree(key);
1716 err_put:
1717 	bpf_map_write_active_dec(map);
1718 	fdput(f);
1719 	return err;
1720 }
1721 
1722 /* last field in 'union bpf_attr' used by this command */
1723 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
1724 
map_get_next_key(union bpf_attr * attr)1725 static int map_get_next_key(union bpf_attr *attr)
1726 {
1727 	void __user *ukey = u64_to_user_ptr(attr->key);
1728 	void __user *unext_key = u64_to_user_ptr(attr->next_key);
1729 	int ufd = attr->map_fd;
1730 	struct bpf_map *map;
1731 	void *key, *next_key;
1732 	struct fd f;
1733 	int err;
1734 
1735 	if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
1736 		return -EINVAL;
1737 
1738 	f = fdget(ufd);
1739 	map = __bpf_map_get(f);
1740 	if (IS_ERR(map))
1741 		return PTR_ERR(map);
1742 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
1743 		err = -EPERM;
1744 		goto err_put;
1745 	}
1746 
1747 	if (ukey) {
1748 		key = __bpf_copy_key(ukey, map->key_size);
1749 		if (IS_ERR(key)) {
1750 			err = PTR_ERR(key);
1751 			goto err_put;
1752 		}
1753 	} else {
1754 		key = NULL;
1755 	}
1756 
1757 	err = -ENOMEM;
1758 	next_key = kvmalloc(map->key_size, GFP_USER);
1759 	if (!next_key)
1760 		goto free_key;
1761 
1762 	if (bpf_map_is_offloaded(map)) {
1763 		err = bpf_map_offload_get_next_key(map, key, next_key);
1764 		goto out;
1765 	}
1766 
1767 	rcu_read_lock();
1768 	err = map->ops->map_get_next_key(map, key, next_key);
1769 	rcu_read_unlock();
1770 out:
1771 	if (err)
1772 		goto free_next_key;
1773 
1774 	err = -EFAULT;
1775 	if (copy_to_user(unext_key, next_key, map->key_size) != 0)
1776 		goto free_next_key;
1777 
1778 	err = 0;
1779 
1780 free_next_key:
1781 	kvfree(next_key);
1782 free_key:
1783 	kvfree(key);
1784 err_put:
1785 	fdput(f);
1786 	return err;
1787 }
1788 
generic_map_delete_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1789 int generic_map_delete_batch(struct bpf_map *map,
1790 			     const union bpf_attr *attr,
1791 			     union bpf_attr __user *uattr)
1792 {
1793 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1794 	u32 cp, max_count;
1795 	int err = 0;
1796 	void *key;
1797 
1798 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1799 		return -EINVAL;
1800 
1801 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1802 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1803 		return -EINVAL;
1804 	}
1805 
1806 	max_count = attr->batch.count;
1807 	if (!max_count)
1808 		return 0;
1809 
1810 	if (put_user(0, &uattr->batch.count))
1811 		return -EFAULT;
1812 
1813 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1814 	if (!key)
1815 		return -ENOMEM;
1816 
1817 	for (cp = 0; cp < max_count; cp++) {
1818 		err = -EFAULT;
1819 		if (copy_from_user(key, keys + cp * map->key_size,
1820 				   map->key_size))
1821 			break;
1822 
1823 		if (bpf_map_is_offloaded(map)) {
1824 			err = bpf_map_offload_delete_elem(map, key);
1825 			break;
1826 		}
1827 
1828 		bpf_disable_instrumentation();
1829 		rcu_read_lock();
1830 		err = map->ops->map_delete_elem(map, key);
1831 		rcu_read_unlock();
1832 		bpf_enable_instrumentation();
1833 		if (err)
1834 			break;
1835 		cond_resched();
1836 	}
1837 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1838 		err = -EFAULT;
1839 
1840 	kvfree(key);
1841 
1842 	return err;
1843 }
1844 
generic_map_update_batch(struct bpf_map * map,struct file * map_file,const union bpf_attr * attr,union bpf_attr __user * uattr)1845 int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
1846 			     const union bpf_attr *attr,
1847 			     union bpf_attr __user *uattr)
1848 {
1849 	void __user *values = u64_to_user_ptr(attr->batch.values);
1850 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1851 	u32 value_size, cp, max_count;
1852 	void *key, *value;
1853 	int err = 0;
1854 
1855 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1856 		return -EINVAL;
1857 
1858 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1859 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
1860 		return -EINVAL;
1861 	}
1862 
1863 	value_size = bpf_map_value_size(map);
1864 
1865 	max_count = attr->batch.count;
1866 	if (!max_count)
1867 		return 0;
1868 
1869 	if (put_user(0, &uattr->batch.count))
1870 		return -EFAULT;
1871 
1872 	key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1873 	if (!key)
1874 		return -ENOMEM;
1875 
1876 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
1877 	if (!value) {
1878 		kvfree(key);
1879 		return -ENOMEM;
1880 	}
1881 
1882 	for (cp = 0; cp < max_count; cp++) {
1883 		err = -EFAULT;
1884 		if (copy_from_user(key, keys + cp * map->key_size,
1885 		    map->key_size) ||
1886 		    copy_from_user(value, values + cp * value_size, value_size))
1887 			break;
1888 
1889 		err = bpf_map_update_value(map, map_file, key, value,
1890 					   attr->batch.elem_flags);
1891 
1892 		if (err)
1893 			break;
1894 		cond_resched();
1895 	}
1896 
1897 	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
1898 		err = -EFAULT;
1899 
1900 	kvfree(value);
1901 	kvfree(key);
1902 
1903 	return err;
1904 }
1905 
1906 #define MAP_LOOKUP_RETRIES 3
1907 
generic_map_lookup_batch(struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)1908 int generic_map_lookup_batch(struct bpf_map *map,
1909 				    const union bpf_attr *attr,
1910 				    union bpf_attr __user *uattr)
1911 {
1912 	void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
1913 	void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
1914 	void __user *values = u64_to_user_ptr(attr->batch.values);
1915 	void __user *keys = u64_to_user_ptr(attr->batch.keys);
1916 	void *buf, *buf_prevkey, *prev_key, *key, *value;
1917 	int err, retry = MAP_LOOKUP_RETRIES;
1918 	u32 value_size, cp, max_count;
1919 
1920 	if (attr->batch.elem_flags & ~BPF_F_LOCK)
1921 		return -EINVAL;
1922 
1923 	if ((attr->batch.elem_flags & BPF_F_LOCK) &&
1924 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK))
1925 		return -EINVAL;
1926 
1927 	value_size = bpf_map_value_size(map);
1928 
1929 	max_count = attr->batch.count;
1930 	if (!max_count)
1931 		return 0;
1932 
1933 	if (put_user(0, &uattr->batch.count))
1934 		return -EFAULT;
1935 
1936 	buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
1937 	if (!buf_prevkey)
1938 		return -ENOMEM;
1939 
1940 	buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
1941 	if (!buf) {
1942 		kvfree(buf_prevkey);
1943 		return -ENOMEM;
1944 	}
1945 
1946 	err = -EFAULT;
1947 	prev_key = NULL;
1948 	if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
1949 		goto free_buf;
1950 	key = buf;
1951 	value = key + map->key_size;
1952 	if (ubatch)
1953 		prev_key = buf_prevkey;
1954 
1955 	for (cp = 0; cp < max_count;) {
1956 		rcu_read_lock();
1957 		err = map->ops->map_get_next_key(map, prev_key, key);
1958 		rcu_read_unlock();
1959 		if (err)
1960 			break;
1961 		err = bpf_map_copy_value(map, key, value,
1962 					 attr->batch.elem_flags);
1963 
1964 		if (err == -ENOENT) {
1965 			if (retry) {
1966 				retry--;
1967 				continue;
1968 			}
1969 			err = -EINTR;
1970 			break;
1971 		}
1972 
1973 		if (err)
1974 			goto free_buf;
1975 
1976 		if (copy_to_user(keys + cp * map->key_size, key,
1977 				 map->key_size)) {
1978 			err = -EFAULT;
1979 			goto free_buf;
1980 		}
1981 		if (copy_to_user(values + cp * value_size, value, value_size)) {
1982 			err = -EFAULT;
1983 			goto free_buf;
1984 		}
1985 
1986 		if (!prev_key)
1987 			prev_key = buf_prevkey;
1988 
1989 		swap(prev_key, key);
1990 		retry = MAP_LOOKUP_RETRIES;
1991 		cp++;
1992 		cond_resched();
1993 	}
1994 
1995 	if (err == -EFAULT)
1996 		goto free_buf;
1997 
1998 	if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
1999 		    (cp && copy_to_user(uobatch, prev_key, map->key_size))))
2000 		err = -EFAULT;
2001 
2002 free_buf:
2003 	kvfree(buf_prevkey);
2004 	kvfree(buf);
2005 	return err;
2006 }
2007 
2008 #define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
2009 
map_lookup_and_delete_elem(union bpf_attr * attr)2010 static int map_lookup_and_delete_elem(union bpf_attr *attr)
2011 {
2012 	void __user *ukey = u64_to_user_ptr(attr->key);
2013 	void __user *uvalue = u64_to_user_ptr(attr->value);
2014 	int ufd = attr->map_fd;
2015 	struct bpf_map *map;
2016 	void *key, *value;
2017 	u32 value_size;
2018 	struct fd f;
2019 	int err;
2020 
2021 	if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
2022 		return -EINVAL;
2023 
2024 	if (attr->flags & ~BPF_F_LOCK)
2025 		return -EINVAL;
2026 
2027 	f = fdget(ufd);
2028 	map = __bpf_map_get(f);
2029 	if (IS_ERR(map))
2030 		return PTR_ERR(map);
2031 	bpf_map_write_active_inc(map);
2032 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
2033 	    !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2034 		err = -EPERM;
2035 		goto err_put;
2036 	}
2037 
2038 	if (attr->flags &&
2039 	    (map->map_type == BPF_MAP_TYPE_QUEUE ||
2040 	     map->map_type == BPF_MAP_TYPE_STACK)) {
2041 		err = -EINVAL;
2042 		goto err_put;
2043 	}
2044 
2045 	if ((attr->flags & BPF_F_LOCK) &&
2046 	    !btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
2047 		err = -EINVAL;
2048 		goto err_put;
2049 	}
2050 
2051 	key = __bpf_copy_key(ukey, map->key_size);
2052 	if (IS_ERR(key)) {
2053 		err = PTR_ERR(key);
2054 		goto err_put;
2055 	}
2056 
2057 	value_size = bpf_map_value_size(map);
2058 
2059 	err = -ENOMEM;
2060 	value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
2061 	if (!value)
2062 		goto free_key;
2063 
2064 	err = -ENOTSUPP;
2065 	if (map->map_type == BPF_MAP_TYPE_QUEUE ||
2066 	    map->map_type == BPF_MAP_TYPE_STACK) {
2067 		err = map->ops->map_pop_elem(map, value);
2068 	} else if (map->map_type == BPF_MAP_TYPE_HASH ||
2069 		   map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
2070 		   map->map_type == BPF_MAP_TYPE_LRU_HASH ||
2071 		   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
2072 		if (!bpf_map_is_offloaded(map)) {
2073 			bpf_disable_instrumentation();
2074 			rcu_read_lock();
2075 			err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
2076 			rcu_read_unlock();
2077 			bpf_enable_instrumentation();
2078 		}
2079 	}
2080 
2081 	if (err)
2082 		goto free_value;
2083 
2084 	if (copy_to_user(uvalue, value, value_size) != 0) {
2085 		err = -EFAULT;
2086 		goto free_value;
2087 	}
2088 
2089 	err = 0;
2090 
2091 free_value:
2092 	kvfree(value);
2093 free_key:
2094 	kvfree(key);
2095 err_put:
2096 	bpf_map_write_active_dec(map);
2097 	fdput(f);
2098 	return err;
2099 }
2100 
2101 #define BPF_MAP_FREEZE_LAST_FIELD map_fd
2102 
map_freeze(const union bpf_attr * attr)2103 static int map_freeze(const union bpf_attr *attr)
2104 {
2105 	int err = 0, ufd = attr->map_fd;
2106 	struct bpf_map *map;
2107 	struct fd f;
2108 
2109 	if (CHECK_ATTR(BPF_MAP_FREEZE))
2110 		return -EINVAL;
2111 
2112 	f = fdget(ufd);
2113 	map = __bpf_map_get(f);
2114 	if (IS_ERR(map))
2115 		return PTR_ERR(map);
2116 
2117 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record)) {
2118 		fdput(f);
2119 		return -ENOTSUPP;
2120 	}
2121 
2122 	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
2123 		fdput(f);
2124 		return -EPERM;
2125 	}
2126 
2127 	mutex_lock(&map->freeze_mutex);
2128 	if (bpf_map_write_active(map)) {
2129 		err = -EBUSY;
2130 		goto err_put;
2131 	}
2132 	if (READ_ONCE(map->frozen)) {
2133 		err = -EBUSY;
2134 		goto err_put;
2135 	}
2136 
2137 	WRITE_ONCE(map->frozen, true);
2138 err_put:
2139 	mutex_unlock(&map->freeze_mutex);
2140 	fdput(f);
2141 	return err;
2142 }
2143 
2144 static const struct bpf_prog_ops * const bpf_prog_types[] = {
2145 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
2146 	[_id] = & _name ## _prog_ops,
2147 #define BPF_MAP_TYPE(_id, _ops)
2148 #define BPF_LINK_TYPE(_id, _name)
2149 #include <linux/bpf_types.h>
2150 #undef BPF_PROG_TYPE
2151 #undef BPF_MAP_TYPE
2152 #undef BPF_LINK_TYPE
2153 };
2154 
find_prog_type(enum bpf_prog_type type,struct bpf_prog * prog)2155 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
2156 {
2157 	const struct bpf_prog_ops *ops;
2158 
2159 	if (type >= ARRAY_SIZE(bpf_prog_types))
2160 		return -EINVAL;
2161 	type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
2162 	ops = bpf_prog_types[type];
2163 	if (!ops)
2164 		return -EINVAL;
2165 
2166 	if (!bpf_prog_is_offloaded(prog->aux))
2167 		prog->aux->ops = ops;
2168 	else
2169 		prog->aux->ops = &bpf_offload_prog_ops;
2170 	prog->type = type;
2171 	return 0;
2172 }
2173 
2174 enum bpf_audit {
2175 	BPF_AUDIT_LOAD,
2176 	BPF_AUDIT_UNLOAD,
2177 	BPF_AUDIT_MAX,
2178 };
2179 
2180 static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
2181 	[BPF_AUDIT_LOAD]   = "LOAD",
2182 	[BPF_AUDIT_UNLOAD] = "UNLOAD",
2183 };
2184 
bpf_audit_prog(const struct bpf_prog * prog,unsigned int op)2185 static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
2186 {
2187 	struct audit_context *ctx = NULL;
2188 	struct audit_buffer *ab;
2189 
2190 	if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
2191 		return;
2192 	if (audit_enabled == AUDIT_OFF)
2193 		return;
2194 	if (!in_irq() && !irqs_disabled())
2195 		ctx = audit_context();
2196 	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
2197 	if (unlikely(!ab))
2198 		return;
2199 	audit_log_format(ab, "prog-id=%u op=%s",
2200 			 prog->aux->id, bpf_audit_str[op]);
2201 	audit_log_end(ab);
2202 }
2203 
bpf_prog_alloc_id(struct bpf_prog * prog)2204 static int bpf_prog_alloc_id(struct bpf_prog *prog)
2205 {
2206 	int id;
2207 
2208 	idr_preload(GFP_KERNEL);
2209 	spin_lock_bh(&prog_idr_lock);
2210 	id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
2211 	if (id > 0)
2212 		prog->aux->id = id;
2213 	spin_unlock_bh(&prog_idr_lock);
2214 	idr_preload_end();
2215 
2216 	/* id is in [1, INT_MAX) */
2217 	if (WARN_ON_ONCE(!id))
2218 		return -ENOSPC;
2219 
2220 	return id > 0 ? 0 : id;
2221 }
2222 
bpf_prog_free_id(struct bpf_prog * prog)2223 void bpf_prog_free_id(struct bpf_prog *prog)
2224 {
2225 	unsigned long flags;
2226 
2227 	/* cBPF to eBPF migrations are currently not in the idr store.
2228 	 * Offloaded programs are removed from the store when their device
2229 	 * disappears - even if someone grabs an fd to them they are unusable,
2230 	 * simply waiting for refcnt to drop to be freed.
2231 	 */
2232 	if (!prog->aux->id)
2233 		return;
2234 
2235 	spin_lock_irqsave(&prog_idr_lock, flags);
2236 	idr_remove(&prog_idr, prog->aux->id);
2237 	prog->aux->id = 0;
2238 	spin_unlock_irqrestore(&prog_idr_lock, flags);
2239 }
2240 
__bpf_prog_put_rcu(struct rcu_head * rcu)2241 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
2242 {
2243 	struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
2244 
2245 	kvfree(aux->func_info);
2246 	kfree(aux->func_info_aux);
2247 	free_uid(aux->user);
2248 	security_bpf_prog_free(aux->prog);
2249 	bpf_prog_free(aux->prog);
2250 }
2251 
__bpf_prog_put_noref(struct bpf_prog * prog,bool deferred)2252 static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
2253 {
2254 	bpf_prog_kallsyms_del_all(prog);
2255 	btf_put(prog->aux->btf);
2256 	module_put(prog->aux->mod);
2257 	kvfree(prog->aux->jited_linfo);
2258 	kvfree(prog->aux->linfo);
2259 	kfree(prog->aux->kfunc_tab);
2260 	if (prog->aux->attach_btf)
2261 		btf_put(prog->aux->attach_btf);
2262 
2263 	if (deferred) {
2264 		if (prog->sleepable)
2265 			call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
2266 		else
2267 			call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
2268 	} else {
2269 		__bpf_prog_put_rcu(&prog->aux->rcu);
2270 	}
2271 }
2272 
bpf_prog_put_deferred(struct work_struct * work)2273 static void bpf_prog_put_deferred(struct work_struct *work)
2274 {
2275 	struct bpf_prog_aux *aux;
2276 	struct bpf_prog *prog;
2277 
2278 	aux = container_of(work, struct bpf_prog_aux, work);
2279 	prog = aux->prog;
2280 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2281 	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
2282 	bpf_prog_free_id(prog);
2283 	__bpf_prog_put_noref(prog, true);
2284 }
2285 
__bpf_prog_put(struct bpf_prog * prog)2286 static void __bpf_prog_put(struct bpf_prog *prog)
2287 {
2288 	struct bpf_prog_aux *aux = prog->aux;
2289 
2290 	if (atomic64_dec_and_test(&aux->refcnt)) {
2291 		if (in_irq() || irqs_disabled()) {
2292 			INIT_WORK(&aux->work, bpf_prog_put_deferred);
2293 			schedule_work(&aux->work);
2294 		} else {
2295 			bpf_prog_put_deferred(&aux->work);
2296 		}
2297 	}
2298 }
2299 
bpf_prog_put(struct bpf_prog * prog)2300 void bpf_prog_put(struct bpf_prog *prog)
2301 {
2302 	__bpf_prog_put(prog);
2303 }
2304 EXPORT_SYMBOL_GPL(bpf_prog_put);
2305 
bpf_prog_release(struct inode * inode,struct file * filp)2306 static int bpf_prog_release(struct inode *inode, struct file *filp)
2307 {
2308 	struct bpf_prog *prog = filp->private_data;
2309 
2310 	bpf_prog_put(prog);
2311 	return 0;
2312 }
2313 
2314 struct bpf_prog_kstats {
2315 	u64 nsecs;
2316 	u64 cnt;
2317 	u64 misses;
2318 };
2319 
bpf_prog_inc_misses_counter(struct bpf_prog * prog)2320 void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
2321 {
2322 	struct bpf_prog_stats *stats;
2323 	unsigned int flags;
2324 
2325 	stats = this_cpu_ptr(prog->stats);
2326 	flags = u64_stats_update_begin_irqsave(&stats->syncp);
2327 	u64_stats_inc(&stats->misses);
2328 	u64_stats_update_end_irqrestore(&stats->syncp, flags);
2329 }
2330 
bpf_prog_get_stats(const struct bpf_prog * prog,struct bpf_prog_kstats * stats)2331 static void bpf_prog_get_stats(const struct bpf_prog *prog,
2332 			       struct bpf_prog_kstats *stats)
2333 {
2334 	u64 nsecs = 0, cnt = 0, misses = 0;
2335 	int cpu;
2336 
2337 	for_each_possible_cpu(cpu) {
2338 		const struct bpf_prog_stats *st;
2339 		unsigned int start;
2340 		u64 tnsecs, tcnt, tmisses;
2341 
2342 		st = per_cpu_ptr(prog->stats, cpu);
2343 		do {
2344 			start = u64_stats_fetch_begin(&st->syncp);
2345 			tnsecs = u64_stats_read(&st->nsecs);
2346 			tcnt = u64_stats_read(&st->cnt);
2347 			tmisses = u64_stats_read(&st->misses);
2348 		} while (u64_stats_fetch_retry(&st->syncp, start));
2349 		nsecs += tnsecs;
2350 		cnt += tcnt;
2351 		misses += tmisses;
2352 	}
2353 	stats->nsecs = nsecs;
2354 	stats->cnt = cnt;
2355 	stats->misses = misses;
2356 }
2357 
2358 #ifdef CONFIG_PROC_FS
bpf_prog_show_fdinfo(struct seq_file * m,struct file * filp)2359 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
2360 {
2361 	const struct bpf_prog *prog = filp->private_data;
2362 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
2363 	struct bpf_prog_kstats stats;
2364 
2365 	bpf_prog_get_stats(prog, &stats);
2366 	bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
2367 	seq_printf(m,
2368 		   "prog_type:\t%u\n"
2369 		   "prog_jited:\t%u\n"
2370 		   "prog_tag:\t%s\n"
2371 		   "memlock:\t%llu\n"
2372 		   "prog_id:\t%u\n"
2373 		   "run_time_ns:\t%llu\n"
2374 		   "run_cnt:\t%llu\n"
2375 		   "recursion_misses:\t%llu\n"
2376 		   "verified_insns:\t%u\n",
2377 		   prog->type,
2378 		   prog->jited,
2379 		   prog_tag,
2380 		   prog->pages * 1ULL << PAGE_SHIFT,
2381 		   prog->aux->id,
2382 		   stats.nsecs,
2383 		   stats.cnt,
2384 		   stats.misses,
2385 		   prog->aux->verified_insns);
2386 }
2387 #endif
2388 
2389 const struct file_operations bpf_prog_fops = {
2390 #ifdef CONFIG_PROC_FS
2391 	.show_fdinfo	= bpf_prog_show_fdinfo,
2392 #endif
2393 	.release	= bpf_prog_release,
2394 	.read		= bpf_dummy_read,
2395 	.write		= bpf_dummy_write,
2396 };
2397 
bpf_prog_new_fd(struct bpf_prog * prog)2398 int bpf_prog_new_fd(struct bpf_prog *prog)
2399 {
2400 	int ret;
2401 
2402 	ret = security_bpf_prog(prog);
2403 	if (ret < 0)
2404 		return ret;
2405 
2406 	return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
2407 				O_RDWR | O_CLOEXEC);
2408 }
2409 
____bpf_prog_get(struct fd f)2410 static struct bpf_prog *____bpf_prog_get(struct fd f)
2411 {
2412 	if (!f.file)
2413 		return ERR_PTR(-EBADF);
2414 	if (f.file->f_op != &bpf_prog_fops) {
2415 		fdput(f);
2416 		return ERR_PTR(-EINVAL);
2417 	}
2418 
2419 	return f.file->private_data;
2420 }
2421 
bpf_prog_add(struct bpf_prog * prog,int i)2422 void bpf_prog_add(struct bpf_prog *prog, int i)
2423 {
2424 	atomic64_add(i, &prog->aux->refcnt);
2425 }
2426 EXPORT_SYMBOL_GPL(bpf_prog_add);
2427 
bpf_prog_sub(struct bpf_prog * prog,int i)2428 void bpf_prog_sub(struct bpf_prog *prog, int i)
2429 {
2430 	/* Only to be used for undoing previous bpf_prog_add() in some
2431 	 * error path. We still know that another entity in our call
2432 	 * path holds a reference to the program, thus atomic_sub() can
2433 	 * be safely used in such cases!
2434 	 */
2435 	WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
2436 }
2437 EXPORT_SYMBOL_GPL(bpf_prog_sub);
2438 
bpf_prog_inc(struct bpf_prog * prog)2439 void bpf_prog_inc(struct bpf_prog *prog)
2440 {
2441 	atomic64_inc(&prog->aux->refcnt);
2442 }
2443 EXPORT_SYMBOL_GPL(bpf_prog_inc);
2444 
2445 /* prog_idr_lock should have been held */
bpf_prog_inc_not_zero(struct bpf_prog * prog)2446 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
2447 {
2448 	int refold;
2449 
2450 	refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
2451 
2452 	if (!refold)
2453 		return ERR_PTR(-ENOENT);
2454 
2455 	return prog;
2456 }
2457 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
2458 
bpf_prog_get_ok(struct bpf_prog * prog,enum bpf_prog_type * attach_type,bool attach_drv)2459 bool bpf_prog_get_ok(struct bpf_prog *prog,
2460 			    enum bpf_prog_type *attach_type, bool attach_drv)
2461 {
2462 	/* not an attachment, just a refcount inc, always allow */
2463 	if (!attach_type)
2464 		return true;
2465 
2466 	if (prog->type != *attach_type)
2467 		return false;
2468 	if (bpf_prog_is_offloaded(prog->aux) && !attach_drv)
2469 		return false;
2470 
2471 	return true;
2472 }
2473 
__bpf_prog_get(u32 ufd,enum bpf_prog_type * attach_type,bool attach_drv)2474 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
2475 				       bool attach_drv)
2476 {
2477 	struct fd f = fdget(ufd);
2478 	struct bpf_prog *prog;
2479 
2480 	prog = ____bpf_prog_get(f);
2481 	if (IS_ERR(prog))
2482 		return prog;
2483 	if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
2484 		prog = ERR_PTR(-EINVAL);
2485 		goto out;
2486 	}
2487 
2488 	bpf_prog_inc(prog);
2489 out:
2490 	fdput(f);
2491 	return prog;
2492 }
2493 
bpf_prog_get(u32 ufd)2494 struct bpf_prog *bpf_prog_get(u32 ufd)
2495 {
2496 	return __bpf_prog_get(ufd, NULL, false);
2497 }
2498 
bpf_prog_get_type_dev(u32 ufd,enum bpf_prog_type type,bool attach_drv)2499 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
2500 				       bool attach_drv)
2501 {
2502 	return __bpf_prog_get(ufd, &type, attach_drv);
2503 }
2504 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
2505 
2506 /* Initially all BPF programs could be loaded w/o specifying
2507  * expected_attach_type. Later for some of them specifying expected_attach_type
2508  * at load time became required so that program could be validated properly.
2509  * Programs of types that are allowed to be loaded both w/ and w/o (for
2510  * backward compatibility) expected_attach_type, should have the default attach
2511  * type assigned to expected_attach_type for the latter case, so that it can be
2512  * validated later at attach time.
2513  *
2514  * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
2515  * prog type requires it but has some attach types that have to be backward
2516  * compatible.
2517  */
bpf_prog_load_fixup_attach_type(union bpf_attr * attr)2518 static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
2519 {
2520 	switch (attr->prog_type) {
2521 	case BPF_PROG_TYPE_CGROUP_SOCK:
2522 		/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
2523 		 * exist so checking for non-zero is the way to go here.
2524 		 */
2525 		if (!attr->expected_attach_type)
2526 			attr->expected_attach_type =
2527 				BPF_CGROUP_INET_SOCK_CREATE;
2528 		break;
2529 	case BPF_PROG_TYPE_SK_REUSEPORT:
2530 		if (!attr->expected_attach_type)
2531 			attr->expected_attach_type =
2532 				BPF_SK_REUSEPORT_SELECT;
2533 		break;
2534 	}
2535 }
2536 
2537 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)2538 bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
2539 			   enum bpf_attach_type expected_attach_type,
2540 			   struct btf *attach_btf, u32 btf_id,
2541 			   struct bpf_prog *dst_prog)
2542 {
2543 	if (btf_id) {
2544 		if (btf_id > BTF_MAX_TYPE)
2545 			return -EINVAL;
2546 
2547 		if (!attach_btf && !dst_prog)
2548 			return -EINVAL;
2549 
2550 		switch (prog_type) {
2551 		case BPF_PROG_TYPE_TRACING:
2552 		case BPF_PROG_TYPE_LSM:
2553 		case BPF_PROG_TYPE_STRUCT_OPS:
2554 		case BPF_PROG_TYPE_EXT:
2555 			break;
2556 		default:
2557 			return -EINVAL;
2558 		}
2559 	}
2560 
2561 	if (attach_btf && (!btf_id || dst_prog))
2562 		return -EINVAL;
2563 
2564 	if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
2565 	    prog_type != BPF_PROG_TYPE_EXT)
2566 		return -EINVAL;
2567 
2568 	switch (prog_type) {
2569 	case BPF_PROG_TYPE_CGROUP_SOCK:
2570 		switch (expected_attach_type) {
2571 		case BPF_CGROUP_INET_SOCK_CREATE:
2572 		case BPF_CGROUP_INET_SOCK_RELEASE:
2573 		case BPF_CGROUP_INET4_POST_BIND:
2574 		case BPF_CGROUP_INET6_POST_BIND:
2575 			return 0;
2576 		default:
2577 			return -EINVAL;
2578 		}
2579 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2580 		switch (expected_attach_type) {
2581 		case BPF_CGROUP_INET4_BIND:
2582 		case BPF_CGROUP_INET6_BIND:
2583 		case BPF_CGROUP_INET4_CONNECT:
2584 		case BPF_CGROUP_INET6_CONNECT:
2585 		case BPF_CGROUP_UNIX_CONNECT:
2586 		case BPF_CGROUP_INET4_GETPEERNAME:
2587 		case BPF_CGROUP_INET6_GETPEERNAME:
2588 		case BPF_CGROUP_UNIX_GETPEERNAME:
2589 		case BPF_CGROUP_INET4_GETSOCKNAME:
2590 		case BPF_CGROUP_INET6_GETSOCKNAME:
2591 		case BPF_CGROUP_UNIX_GETSOCKNAME:
2592 		case BPF_CGROUP_UDP4_SENDMSG:
2593 		case BPF_CGROUP_UDP6_SENDMSG:
2594 		case BPF_CGROUP_UNIX_SENDMSG:
2595 		case BPF_CGROUP_UDP4_RECVMSG:
2596 		case BPF_CGROUP_UDP6_RECVMSG:
2597 		case BPF_CGROUP_UNIX_RECVMSG:
2598 			return 0;
2599 		default:
2600 			return -EINVAL;
2601 		}
2602 	case BPF_PROG_TYPE_CGROUP_SKB:
2603 		switch (expected_attach_type) {
2604 		case BPF_CGROUP_INET_INGRESS:
2605 		case BPF_CGROUP_INET_EGRESS:
2606 			return 0;
2607 		default:
2608 			return -EINVAL;
2609 		}
2610 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2611 		switch (expected_attach_type) {
2612 		case BPF_CGROUP_SETSOCKOPT:
2613 		case BPF_CGROUP_GETSOCKOPT:
2614 			return 0;
2615 		default:
2616 			return -EINVAL;
2617 		}
2618 	case BPF_PROG_TYPE_SK_LOOKUP:
2619 		if (expected_attach_type == BPF_SK_LOOKUP)
2620 			return 0;
2621 		return -EINVAL;
2622 	case BPF_PROG_TYPE_SK_REUSEPORT:
2623 		switch (expected_attach_type) {
2624 		case BPF_SK_REUSEPORT_SELECT:
2625 		case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
2626 			return 0;
2627 		default:
2628 			return -EINVAL;
2629 		}
2630 	case BPF_PROG_TYPE_NETFILTER:
2631 		if (expected_attach_type == BPF_NETFILTER)
2632 			return 0;
2633 		return -EINVAL;
2634 	case BPF_PROG_TYPE_SYSCALL:
2635 	case BPF_PROG_TYPE_EXT:
2636 		if (expected_attach_type)
2637 			return -EINVAL;
2638 		fallthrough;
2639 	default:
2640 		return 0;
2641 	}
2642 }
2643 
is_net_admin_prog_type(enum bpf_prog_type prog_type)2644 static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
2645 {
2646 	switch (prog_type) {
2647 	case BPF_PROG_TYPE_SCHED_CLS:
2648 	case BPF_PROG_TYPE_SCHED_ACT:
2649 	case BPF_PROG_TYPE_XDP:
2650 	case BPF_PROG_TYPE_LWT_IN:
2651 	case BPF_PROG_TYPE_LWT_OUT:
2652 	case BPF_PROG_TYPE_LWT_XMIT:
2653 	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2654 	case BPF_PROG_TYPE_SK_SKB:
2655 	case BPF_PROG_TYPE_SK_MSG:
2656 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
2657 	case BPF_PROG_TYPE_CGROUP_DEVICE:
2658 	case BPF_PROG_TYPE_CGROUP_SOCK:
2659 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2660 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
2661 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
2662 	case BPF_PROG_TYPE_SOCK_OPS:
2663 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2664 	case BPF_PROG_TYPE_NETFILTER:
2665 		return true;
2666 	case BPF_PROG_TYPE_CGROUP_SKB:
2667 		/* always unpriv */
2668 	case BPF_PROG_TYPE_SK_REUSEPORT:
2669 		/* equivalent to SOCKET_FILTER. need CAP_BPF only */
2670 	default:
2671 		return false;
2672 	}
2673 }
2674 
is_perfmon_prog_type(enum bpf_prog_type prog_type)2675 static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
2676 {
2677 	switch (prog_type) {
2678 	case BPF_PROG_TYPE_KPROBE:
2679 	case BPF_PROG_TYPE_TRACEPOINT:
2680 	case BPF_PROG_TYPE_PERF_EVENT:
2681 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
2682 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2683 	case BPF_PROG_TYPE_TRACING:
2684 	case BPF_PROG_TYPE_LSM:
2685 	case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
2686 	case BPF_PROG_TYPE_EXT: /* extends any prog */
2687 		return true;
2688 	default:
2689 		return false;
2690 	}
2691 }
2692 
2693 /* last field in 'union bpf_attr' used by this command */
2694 #define BPF_PROG_LOAD_LAST_FIELD prog_token_fd
2695 
bpf_prog_load(union bpf_attr * attr,bpfptr_t uattr,u32 uattr_size)2696 static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
2697 {
2698 	enum bpf_prog_type type = attr->prog_type;
2699 	struct bpf_prog *prog, *dst_prog = NULL;
2700 	struct btf *attach_btf = NULL;
2701 	struct bpf_token *token = NULL;
2702 	bool bpf_cap;
2703 	int err;
2704 	char license[128];
2705 
2706 	if (CHECK_ATTR(BPF_PROG_LOAD))
2707 		return -EINVAL;
2708 
2709 	if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
2710 				 BPF_F_ANY_ALIGNMENT |
2711 				 BPF_F_TEST_STATE_FREQ |
2712 				 BPF_F_SLEEPABLE |
2713 				 BPF_F_TEST_RND_HI32 |
2714 				 BPF_F_XDP_HAS_FRAGS |
2715 				 BPF_F_XDP_DEV_BOUND_ONLY |
2716 				 BPF_F_TEST_REG_INVARIANTS |
2717 				 BPF_F_TOKEN_FD))
2718 		return -EINVAL;
2719 
2720 	bpf_prog_load_fixup_attach_type(attr);
2721 
2722 	if (attr->prog_flags & BPF_F_TOKEN_FD) {
2723 		token = bpf_token_get_from_fd(attr->prog_token_fd);
2724 		if (IS_ERR(token))
2725 			return PTR_ERR(token);
2726 		/* if current token doesn't grant prog loading permissions,
2727 		 * then we can't use this token, so ignore it and rely on
2728 		 * system-wide capabilities checks
2729 		 */
2730 		if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
2731 		    !bpf_token_allow_prog_type(token, attr->prog_type,
2732 					       attr->expected_attach_type)) {
2733 			bpf_token_put(token);
2734 			token = NULL;
2735 		}
2736 	}
2737 
2738 	bpf_cap = bpf_token_capable(token, CAP_BPF);
2739 	err = -EPERM;
2740 
2741 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
2742 	    (attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
2743 	    !bpf_cap)
2744 		goto put_token;
2745 
2746 	/* Intent here is for unprivileged_bpf_disabled to block BPF program
2747 	 * creation for unprivileged users; other actions depend
2748 	 * on fd availability and access to bpffs, so are dependent on
2749 	 * object creation success. Even with unprivileged BPF disabled,
2750 	 * capability checks are still carried out for these
2751 	 * and other operations.
2752 	 */
2753 	if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
2754 		goto put_token;
2755 
2756 	if (attr->insn_cnt == 0 ||
2757 	    attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
2758 		err = -E2BIG;
2759 		goto put_token;
2760 	}
2761 	if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
2762 	    type != BPF_PROG_TYPE_CGROUP_SKB &&
2763 	    !bpf_cap)
2764 		goto put_token;
2765 
2766 	if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
2767 		goto put_token;
2768 	if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
2769 		goto put_token;
2770 
2771 	/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
2772 	 * or btf, we need to check which one it is
2773 	 */
2774 	if (attr->attach_prog_fd) {
2775 		dst_prog = bpf_prog_get(attr->attach_prog_fd);
2776 		if (IS_ERR(dst_prog)) {
2777 			dst_prog = NULL;
2778 			attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
2779 			if (IS_ERR(attach_btf)) {
2780 				err = -EINVAL;
2781 				goto put_token;
2782 			}
2783 			if (!btf_is_kernel(attach_btf)) {
2784 				/* attaching through specifying bpf_prog's BTF
2785 				 * objects directly might be supported eventually
2786 				 */
2787 				btf_put(attach_btf);
2788 				err = -ENOTSUPP;
2789 				goto put_token;
2790 			}
2791 		}
2792 	} else if (attr->attach_btf_id) {
2793 		/* fall back to vmlinux BTF, if BTF type ID is specified */
2794 		attach_btf = bpf_get_btf_vmlinux();
2795 		if (IS_ERR(attach_btf)) {
2796 			err = PTR_ERR(attach_btf);
2797 			goto put_token;
2798 		}
2799 		if (!attach_btf) {
2800 			err = -EINVAL;
2801 			goto put_token;
2802 		}
2803 		btf_get(attach_btf);
2804 	}
2805 
2806 	if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
2807 				       attach_btf, attr->attach_btf_id,
2808 				       dst_prog)) {
2809 		if (dst_prog)
2810 			bpf_prog_put(dst_prog);
2811 		if (attach_btf)
2812 			btf_put(attach_btf);
2813 		err = -EINVAL;
2814 		goto put_token;
2815 	}
2816 
2817 	/* plain bpf_prog allocation */
2818 	prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
2819 	if (!prog) {
2820 		if (dst_prog)
2821 			bpf_prog_put(dst_prog);
2822 		if (attach_btf)
2823 			btf_put(attach_btf);
2824 		err = -EINVAL;
2825 		goto put_token;
2826 	}
2827 
2828 	prog->expected_attach_type = attr->expected_attach_type;
2829 	prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
2830 	prog->aux->attach_btf = attach_btf;
2831 	prog->aux->attach_btf_id = attr->attach_btf_id;
2832 	prog->aux->dst_prog = dst_prog;
2833 	prog->aux->dev_bound = !!attr->prog_ifindex;
2834 	prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
2835 
2836 	/* move token into prog->aux, reuse taken refcnt */
2837 	prog->aux->token = token;
2838 	token = NULL;
2839 
2840 	prog->aux->user = get_current_user();
2841 	prog->len = attr->insn_cnt;
2842 
2843 	err = -EFAULT;
2844 	if (copy_from_bpfptr(prog->insns,
2845 			     make_bpfptr(attr->insns, uattr.is_kernel),
2846 			     bpf_prog_insn_size(prog)) != 0)
2847 		goto free_prog;
2848 	/* copy eBPF program license from user space */
2849 	if (strncpy_from_bpfptr(license,
2850 				make_bpfptr(attr->license, uattr.is_kernel),
2851 				sizeof(license) - 1) < 0)
2852 		goto free_prog;
2853 	license[sizeof(license) - 1] = 0;
2854 
2855 	/* eBPF programs must be GPL compatible to use GPL-ed functions */
2856 	prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
2857 
2858 	prog->orig_prog = NULL;
2859 	prog->jited = 0;
2860 
2861 	atomic64_set(&prog->aux->refcnt, 1);
2862 
2863 	if (bpf_prog_is_dev_bound(prog->aux)) {
2864 		err = bpf_prog_dev_bound_init(prog, attr);
2865 		if (err)
2866 			goto free_prog;
2867 	}
2868 
2869 	if (type == BPF_PROG_TYPE_EXT && dst_prog &&
2870 	    bpf_prog_is_dev_bound(dst_prog->aux)) {
2871 		err = bpf_prog_dev_bound_inherit(prog, dst_prog);
2872 		if (err)
2873 			goto free_prog;
2874 	}
2875 
2876 	/*
2877 	 * Bookkeeping for managing the program attachment chain.
2878 	 *
2879 	 * It might be tempting to set attach_tracing_prog flag at the attachment
2880 	 * time, but this will not prevent from loading bunch of tracing prog
2881 	 * first, then attach them one to another.
2882 	 *
2883 	 * The flag attach_tracing_prog is set for the whole program lifecycle, and
2884 	 * doesn't have to be cleared in bpf_tracing_link_release, since tracing
2885 	 * programs cannot change attachment target.
2886 	 */
2887 	if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
2888 	    dst_prog->type == BPF_PROG_TYPE_TRACING) {
2889 		prog->aux->attach_tracing_prog = true;
2890 	}
2891 
2892 	/* find program type: socket_filter vs tracing_filter */
2893 	err = find_prog_type(type, prog);
2894 	if (err < 0)
2895 		goto free_prog;
2896 
2897 	prog->aux->load_time = ktime_get_boottime_ns();
2898 	err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
2899 			       sizeof(attr->prog_name));
2900 	if (err < 0)
2901 		goto free_prog;
2902 
2903 	err = security_bpf_prog_load(prog, attr, token);
2904 	if (err)
2905 		goto free_prog_sec;
2906 
2907 	/* run eBPF verifier */
2908 	err = bpf_check(&prog, attr, uattr, uattr_size);
2909 	if (err < 0)
2910 		goto free_used_maps;
2911 
2912 	prog = bpf_prog_select_runtime(prog, &err);
2913 	if (err < 0)
2914 		goto free_used_maps;
2915 
2916 	err = bpf_prog_alloc_id(prog);
2917 	if (err)
2918 		goto free_used_maps;
2919 
2920 	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
2921 	 * effectively publicly exposed. However, retrieving via
2922 	 * bpf_prog_get_fd_by_id() will take another reference,
2923 	 * therefore it cannot be gone underneath us.
2924 	 *
2925 	 * Only for the time /after/ successful bpf_prog_new_fd()
2926 	 * and before returning to userspace, we might just hold
2927 	 * one reference and any parallel close on that fd could
2928 	 * rip everything out. Hence, below notifications must
2929 	 * happen before bpf_prog_new_fd().
2930 	 *
2931 	 * Also, any failure handling from this point onwards must
2932 	 * be using bpf_prog_put() given the program is exposed.
2933 	 */
2934 	bpf_prog_kallsyms_add(prog);
2935 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
2936 	bpf_audit_prog(prog, BPF_AUDIT_LOAD);
2937 
2938 	err = bpf_prog_new_fd(prog);
2939 	if (err < 0)
2940 		bpf_prog_put(prog);
2941 	return err;
2942 
2943 free_used_maps:
2944 	/* In case we have subprogs, we need to wait for a grace
2945 	 * period before we can tear down JIT memory since symbols
2946 	 * are already exposed under kallsyms.
2947 	 */
2948 	__bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
2949 	return err;
2950 
2951 free_prog_sec:
2952 	security_bpf_prog_free(prog);
2953 free_prog:
2954 	free_uid(prog->aux->user);
2955 	if (prog->aux->attach_btf)
2956 		btf_put(prog->aux->attach_btf);
2957 	bpf_prog_free(prog);
2958 put_token:
2959 	bpf_token_put(token);
2960 	return err;
2961 }
2962 
2963 #define BPF_OBJ_LAST_FIELD path_fd
2964 
bpf_obj_pin(const union bpf_attr * attr)2965 static int bpf_obj_pin(const union bpf_attr *attr)
2966 {
2967 	int path_fd;
2968 
2969 	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
2970 		return -EINVAL;
2971 
2972 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
2973 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
2974 		return -EINVAL;
2975 
2976 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
2977 	return bpf_obj_pin_user(attr->bpf_fd, path_fd,
2978 				u64_to_user_ptr(attr->pathname));
2979 }
2980 
bpf_obj_get(const union bpf_attr * attr)2981 static int bpf_obj_get(const union bpf_attr *attr)
2982 {
2983 	int path_fd;
2984 
2985 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
2986 	    attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
2987 		return -EINVAL;
2988 
2989 	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
2990 	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
2991 		return -EINVAL;
2992 
2993 	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
2994 	return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
2995 				attr->file_flags);
2996 }
2997 
bpf_link_init(struct bpf_link * link,enum bpf_link_type type,const struct bpf_link_ops * ops,struct bpf_prog * prog)2998 void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
2999 		   const struct bpf_link_ops *ops, struct bpf_prog *prog)
3000 {
3001 	WARN_ON(ops->dealloc && ops->dealloc_deferred);
3002 	atomic64_set(&link->refcnt, 1);
3003 	link->type = type;
3004 	link->id = 0;
3005 	link->ops = ops;
3006 	link->prog = prog;
3007 }
3008 
bpf_link_free_id(int id)3009 static void bpf_link_free_id(int id)
3010 {
3011 	if (!id)
3012 		return;
3013 
3014 	spin_lock_bh(&link_idr_lock);
3015 	idr_remove(&link_idr, id);
3016 	spin_unlock_bh(&link_idr_lock);
3017 }
3018 
3019 /* Clean up bpf_link and corresponding anon_inode file and FD. After
3020  * anon_inode is created, bpf_link can't be just kfree()'d due to deferred
3021  * anon_inode's release() call. This helper marks bpf_link as
3022  * defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
3023  * is not decremented, it's the responsibility of a calling code that failed
3024  * to complete bpf_link initialization.
3025  * This helper eventually calls link's dealloc callback, but does not call
3026  * link's release callback.
3027  */
bpf_link_cleanup(struct bpf_link_primer * primer)3028 void bpf_link_cleanup(struct bpf_link_primer *primer)
3029 {
3030 	primer->link->prog = NULL;
3031 	bpf_link_free_id(primer->id);
3032 	fput(primer->file);
3033 	put_unused_fd(primer->fd);
3034 }
3035 
bpf_link_inc(struct bpf_link * link)3036 void bpf_link_inc(struct bpf_link *link)
3037 {
3038 	atomic64_inc(&link->refcnt);
3039 }
3040 
bpf_link_defer_dealloc_rcu_gp(struct rcu_head * rcu)3041 static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
3042 {
3043 	struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
3044 
3045 	/* free bpf_link and its containing memory */
3046 	link->ops->dealloc_deferred(link);
3047 }
3048 
bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head * rcu)3049 static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
3050 {
3051 	if (rcu_trace_implies_rcu_gp())
3052 		bpf_link_defer_dealloc_rcu_gp(rcu);
3053 	else
3054 		call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
3055 }
3056 
3057 /* bpf_link_free is guaranteed to be called from process context */
bpf_link_free(struct bpf_link * link)3058 static void bpf_link_free(struct bpf_link *link)
3059 {
3060 	const struct bpf_link_ops *ops = link->ops;
3061 	bool sleepable = false;
3062 
3063 	bpf_link_free_id(link->id);
3064 	if (link->prog) {
3065 		sleepable = link->prog->sleepable;
3066 		/* detach BPF program, clean up used resources */
3067 		ops->release(link);
3068 		bpf_prog_put(link->prog);
3069 	}
3070 	if (ops->dealloc_deferred) {
3071 		/* schedule BPF link deallocation; if underlying BPF program
3072 		 * is sleepable, we need to first wait for RCU tasks trace
3073 		 * sync, then go through "classic" RCU grace period
3074 		 */
3075 		if (sleepable)
3076 			call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
3077 		else
3078 			call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
3079 	} else if (ops->dealloc)
3080 		ops->dealloc(link);
3081 }
3082 
bpf_link_put_deferred(struct work_struct * work)3083 static void bpf_link_put_deferred(struct work_struct *work)
3084 {
3085 	struct bpf_link *link = container_of(work, struct bpf_link, work);
3086 
3087 	bpf_link_free(link);
3088 }
3089 
3090 /* bpf_link_put might be called from atomic context. It needs to be called
3091  * from sleepable context in order to acquire sleeping locks during the process.
3092  */
bpf_link_put(struct bpf_link * link)3093 void bpf_link_put(struct bpf_link *link)
3094 {
3095 	if (!atomic64_dec_and_test(&link->refcnt))
3096 		return;
3097 
3098 	INIT_WORK(&link->work, bpf_link_put_deferred);
3099 	schedule_work(&link->work);
3100 }
3101 EXPORT_SYMBOL(bpf_link_put);
3102 
bpf_link_put_direct(struct bpf_link * link)3103 static void bpf_link_put_direct(struct bpf_link *link)
3104 {
3105 	if (!atomic64_dec_and_test(&link->refcnt))
3106 		return;
3107 	bpf_link_free(link);
3108 }
3109 
bpf_link_release(struct inode * inode,struct file * filp)3110 static int bpf_link_release(struct inode *inode, struct file *filp)
3111 {
3112 	struct bpf_link *link = filp->private_data;
3113 
3114 	bpf_link_put_direct(link);
3115 	return 0;
3116 }
3117 
3118 #ifdef CONFIG_PROC_FS
3119 #define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
3120 #define BPF_MAP_TYPE(_id, _ops)
3121 #define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
3122 static const char *bpf_link_type_strs[] = {
3123 	[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
3124 #include <linux/bpf_types.h>
3125 };
3126 #undef BPF_PROG_TYPE
3127 #undef BPF_MAP_TYPE
3128 #undef BPF_LINK_TYPE
3129 
bpf_link_show_fdinfo(struct seq_file * m,struct file * filp)3130 static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
3131 {
3132 	const struct bpf_link *link = filp->private_data;
3133 	const struct bpf_prog *prog = link->prog;
3134 	char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
3135 
3136 	seq_printf(m,
3137 		   "link_type:\t%s\n"
3138 		   "link_id:\t%u\n",
3139 		   bpf_link_type_strs[link->type],
3140 		   link->id);
3141 	if (prog) {
3142 		bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
3143 		seq_printf(m,
3144 			   "prog_tag:\t%s\n"
3145 			   "prog_id:\t%u\n",
3146 			   prog_tag,
3147 			   prog->aux->id);
3148 	}
3149 	if (link->ops->show_fdinfo)
3150 		link->ops->show_fdinfo(link, m);
3151 }
3152 #endif
3153 
3154 static const struct file_operations bpf_link_fops = {
3155 #ifdef CONFIG_PROC_FS
3156 	.show_fdinfo	= bpf_link_show_fdinfo,
3157 #endif
3158 	.release	= bpf_link_release,
3159 	.read		= bpf_dummy_read,
3160 	.write		= bpf_dummy_write,
3161 };
3162 
bpf_link_alloc_id(struct bpf_link * link)3163 static int bpf_link_alloc_id(struct bpf_link *link)
3164 {
3165 	int id;
3166 
3167 	idr_preload(GFP_KERNEL);
3168 	spin_lock_bh(&link_idr_lock);
3169 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3170 	spin_unlock_bh(&link_idr_lock);
3171 	idr_preload_end();
3172 
3173 	return id;
3174 }
3175 
3176 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3177  * reserving unused FD and allocating ID from link_idr. This is to be paired
3178  * with bpf_link_settle() to install FD and ID and expose bpf_link to
3179  * user-space, if bpf_link is successfully attached. If not, bpf_link and
3180  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3181  * transient state is passed around in struct bpf_link_primer.
3182  * This is preferred way to create and initialize bpf_link, especially when
3183  * there are complicated and expensive operations in between creating bpf_link
3184  * itself and attaching it to BPF hook. By using bpf_link_prime() and
3185  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3186  * expensive (and potentially failing) roll back operations in a rare case
3187  * that file, FD, or ID can't be allocated.
3188  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3189 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3190 {
3191 	struct file *file;
3192 	int fd, id;
3193 
3194 	fd = get_unused_fd_flags(O_CLOEXEC);
3195 	if (fd < 0)
3196 		return fd;
3197 
3198 
3199 	id = bpf_link_alloc_id(link);
3200 	if (id < 0) {
3201 		put_unused_fd(fd);
3202 		return id;
3203 	}
3204 
3205 	file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
3206 	if (IS_ERR(file)) {
3207 		bpf_link_free_id(id);
3208 		put_unused_fd(fd);
3209 		return PTR_ERR(file);
3210 	}
3211 
3212 	primer->link = link;
3213 	primer->file = file;
3214 	primer->fd = fd;
3215 	primer->id = id;
3216 	return 0;
3217 }
3218 
bpf_link_settle(struct bpf_link_primer * primer)3219 int bpf_link_settle(struct bpf_link_primer *primer)
3220 {
3221 	/* make bpf_link fetchable by ID */
3222 	spin_lock_bh(&link_idr_lock);
3223 	primer->link->id = primer->id;
3224 	spin_unlock_bh(&link_idr_lock);
3225 	/* make bpf_link fetchable by FD */
3226 	fd_install(primer->fd, primer->file);
3227 	/* pass through installed FD */
3228 	return primer->fd;
3229 }
3230 
bpf_link_new_fd(struct bpf_link * link)3231 int bpf_link_new_fd(struct bpf_link *link)
3232 {
3233 	return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
3234 }
3235 
bpf_link_get_from_fd(u32 ufd)3236 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3237 {
3238 	struct fd f = fdget(ufd);
3239 	struct bpf_link *link;
3240 
3241 	if (!f.file)
3242 		return ERR_PTR(-EBADF);
3243 	if (f.file->f_op != &bpf_link_fops) {
3244 		fdput(f);
3245 		return ERR_PTR(-EINVAL);
3246 	}
3247 
3248 	link = f.file->private_data;
3249 	bpf_link_inc(link);
3250 	fdput(f);
3251 
3252 	return link;
3253 }
3254 EXPORT_SYMBOL(bpf_link_get_from_fd);
3255 
bpf_tracing_link_release(struct bpf_link * link)3256 static void bpf_tracing_link_release(struct bpf_link *link)
3257 {
3258 	struct bpf_tracing_link *tr_link =
3259 		container_of(link, struct bpf_tracing_link, link.link);
3260 
3261 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3262 						tr_link->trampoline));
3263 
3264 	bpf_trampoline_put(tr_link->trampoline);
3265 
3266 	/* tgt_prog is NULL if target is a kernel function */
3267 	if (tr_link->tgt_prog)
3268 		bpf_prog_put(tr_link->tgt_prog);
3269 }
3270 
bpf_tracing_link_dealloc(struct bpf_link * link)3271 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3272 {
3273 	struct bpf_tracing_link *tr_link =
3274 		container_of(link, struct bpf_tracing_link, link.link);
3275 
3276 	kfree(tr_link);
3277 }
3278 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3279 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3280 					 struct seq_file *seq)
3281 {
3282 	struct bpf_tracing_link *tr_link =
3283 		container_of(link, struct bpf_tracing_link, link.link);
3284 	u32 target_btf_id, target_obj_id;
3285 
3286 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3287 				  &target_obj_id, &target_btf_id);
3288 	seq_printf(seq,
3289 		   "attach_type:\t%d\n"
3290 		   "target_obj_id:\t%u\n"
3291 		   "target_btf_id:\t%u\n",
3292 		   tr_link->attach_type,
3293 		   target_obj_id,
3294 		   target_btf_id);
3295 }
3296 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3297 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3298 					   struct bpf_link_info *info)
3299 {
3300 	struct bpf_tracing_link *tr_link =
3301 		container_of(link, struct bpf_tracing_link, link.link);
3302 
3303 	info->tracing.attach_type = tr_link->attach_type;
3304 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3305 				  &info->tracing.target_obj_id,
3306 				  &info->tracing.target_btf_id);
3307 
3308 	return 0;
3309 }
3310 
3311 static const struct bpf_link_ops bpf_tracing_link_lops = {
3312 	.release = bpf_tracing_link_release,
3313 	.dealloc = bpf_tracing_link_dealloc,
3314 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3315 	.fill_link_info = bpf_tracing_link_fill_link_info,
3316 };
3317 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)3318 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3319 				   int tgt_prog_fd,
3320 				   u32 btf_id,
3321 				   u64 bpf_cookie)
3322 {
3323 	struct bpf_link_primer link_primer;
3324 	struct bpf_prog *tgt_prog = NULL;
3325 	struct bpf_trampoline *tr = NULL;
3326 	struct bpf_tracing_link *link;
3327 	u64 key = 0;
3328 	int err;
3329 
3330 	switch (prog->type) {
3331 	case BPF_PROG_TYPE_TRACING:
3332 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3333 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3334 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3335 			err = -EINVAL;
3336 			goto out_put_prog;
3337 		}
3338 		break;
3339 	case BPF_PROG_TYPE_EXT:
3340 		if (prog->expected_attach_type != 0) {
3341 			err = -EINVAL;
3342 			goto out_put_prog;
3343 		}
3344 		break;
3345 	case BPF_PROG_TYPE_LSM:
3346 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3347 			err = -EINVAL;
3348 			goto out_put_prog;
3349 		}
3350 		break;
3351 	default:
3352 		err = -EINVAL;
3353 		goto out_put_prog;
3354 	}
3355 
3356 	if (!!tgt_prog_fd != !!btf_id) {
3357 		err = -EINVAL;
3358 		goto out_put_prog;
3359 	}
3360 
3361 	if (tgt_prog_fd) {
3362 		/*
3363 		 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3364 		 * part would be changed to implement the same for
3365 		 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3366 		 * attach_tracing_prog flag is set.
3367 		 */
3368 		if (prog->type != BPF_PROG_TYPE_EXT) {
3369 			err = -EINVAL;
3370 			goto out_put_prog;
3371 		}
3372 
3373 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3374 		if (IS_ERR(tgt_prog)) {
3375 			err = PTR_ERR(tgt_prog);
3376 			tgt_prog = NULL;
3377 			goto out_put_prog;
3378 		}
3379 
3380 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3381 	}
3382 
3383 	link = kzalloc(sizeof(*link), GFP_USER);
3384 	if (!link) {
3385 		err = -ENOMEM;
3386 		goto out_put_prog;
3387 	}
3388 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3389 		      &bpf_tracing_link_lops, prog);
3390 	link->attach_type = prog->expected_attach_type;
3391 	link->link.cookie = bpf_cookie;
3392 
3393 	mutex_lock(&prog->aux->dst_mutex);
3394 
3395 	/* There are a few possible cases here:
3396 	 *
3397 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3398 	 *   and not yet attached to anything, so we can use the values stored
3399 	 *   in prog->aux
3400 	 *
3401 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3402          *   attached to a target and its initial target was cleared (below)
3403 	 *
3404 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3405 	 *   target_btf_id using the link_create API.
3406 	 *
3407 	 * - if tgt_prog == NULL when this function was called using the old
3408 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3409 	 *
3410 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3411 	 *   was detached and is going for re-attachment.
3412 	 *
3413 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3414 	 *   are NULL, then program was already attached and user did not provide
3415 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3416 	 */
3417 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3418 		/*
3419 		 * Allow re-attach for TRACING and LSM programs. If it's
3420 		 * currently linked, bpf_trampoline_link_prog will fail.
3421 		 * EXT programs need to specify tgt_prog_fd, so they
3422 		 * re-attach in separate code path.
3423 		 */
3424 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3425 		    prog->type != BPF_PROG_TYPE_LSM) {
3426 			err = -EINVAL;
3427 			goto out_unlock;
3428 		}
3429 		/* We can allow re-attach only if we have valid attach_btf. */
3430 		if (!prog->aux->attach_btf) {
3431 			err = -EINVAL;
3432 			goto out_unlock;
3433 		}
3434 		btf_id = prog->aux->attach_btf_id;
3435 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3436 	}
3437 
3438 	if (!prog->aux->dst_trampoline ||
3439 	    (key && key != prog->aux->dst_trampoline->key)) {
3440 		/* If there is no saved target, or the specified target is
3441 		 * different from the destination specified at load time, we
3442 		 * need a new trampoline and a check for compatibility
3443 		 */
3444 		struct bpf_attach_target_info tgt_info = {};
3445 
3446 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3447 					      &tgt_info);
3448 		if (err)
3449 			goto out_unlock;
3450 
3451 		if (tgt_info.tgt_mod) {
3452 			module_put(prog->aux->mod);
3453 			prog->aux->mod = tgt_info.tgt_mod;
3454 		}
3455 
3456 		tr = bpf_trampoline_get(key, &tgt_info);
3457 		if (!tr) {
3458 			err = -ENOMEM;
3459 			goto out_unlock;
3460 		}
3461 	} else {
3462 		/* The caller didn't specify a target, or the target was the
3463 		 * same as the destination supplied during program load. This
3464 		 * means we can reuse the trampoline and reference from program
3465 		 * load time, and there is no need to allocate a new one. This
3466 		 * can only happen once for any program, as the saved values in
3467 		 * prog->aux are cleared below.
3468 		 */
3469 		tr = prog->aux->dst_trampoline;
3470 		tgt_prog = prog->aux->dst_prog;
3471 	}
3472 
3473 	err = bpf_link_prime(&link->link.link, &link_primer);
3474 	if (err)
3475 		goto out_unlock;
3476 
3477 	err = bpf_trampoline_link_prog(&link->link, tr);
3478 	if (err) {
3479 		bpf_link_cleanup(&link_primer);
3480 		link = NULL;
3481 		goto out_unlock;
3482 	}
3483 
3484 	link->tgt_prog = tgt_prog;
3485 	link->trampoline = tr;
3486 
3487 	/* Always clear the trampoline and target prog from prog->aux to make
3488 	 * sure the original attach destination is not kept alive after a
3489 	 * program is (re-)attached to another target.
3490 	 */
3491 	if (prog->aux->dst_prog &&
3492 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3493 		/* got extra prog ref from syscall, or attaching to different prog */
3494 		bpf_prog_put(prog->aux->dst_prog);
3495 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3496 		/* we allocated a new trampoline, so free the old one */
3497 		bpf_trampoline_put(prog->aux->dst_trampoline);
3498 
3499 	prog->aux->dst_prog = NULL;
3500 	prog->aux->dst_trampoline = NULL;
3501 	mutex_unlock(&prog->aux->dst_mutex);
3502 
3503 	return bpf_link_settle(&link_primer);
3504 out_unlock:
3505 	if (tr && tr != prog->aux->dst_trampoline)
3506 		bpf_trampoline_put(tr);
3507 	mutex_unlock(&prog->aux->dst_mutex);
3508 	kfree(link);
3509 out_put_prog:
3510 	if (tgt_prog_fd && tgt_prog)
3511 		bpf_prog_put(tgt_prog);
3512 	return err;
3513 }
3514 
bpf_raw_tp_link_release(struct bpf_link * link)3515 static void bpf_raw_tp_link_release(struct bpf_link *link)
3516 {
3517 	struct bpf_raw_tp_link *raw_tp =
3518 		container_of(link, struct bpf_raw_tp_link, link);
3519 
3520 	bpf_probe_unregister(raw_tp->btp, raw_tp);
3521 	bpf_put_raw_tracepoint(raw_tp->btp);
3522 }
3523 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3524 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3525 {
3526 	struct bpf_raw_tp_link *raw_tp =
3527 		container_of(link, struct bpf_raw_tp_link, link);
3528 
3529 	kfree(raw_tp);
3530 }
3531 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3532 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3533 					struct seq_file *seq)
3534 {
3535 	struct bpf_raw_tp_link *raw_tp_link =
3536 		container_of(link, struct bpf_raw_tp_link, link);
3537 
3538 	seq_printf(seq,
3539 		   "tp_name:\t%s\n",
3540 		   raw_tp_link->btp->tp->name);
3541 }
3542 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3543 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3544 			    u32 len)
3545 {
3546 	if (ulen >= len + 1) {
3547 		if (copy_to_user(ubuf, buf, len + 1))
3548 			return -EFAULT;
3549 	} else {
3550 		char zero = '\0';
3551 
3552 		if (copy_to_user(ubuf, buf, ulen - 1))
3553 			return -EFAULT;
3554 		if (put_user(zero, ubuf + ulen - 1))
3555 			return -EFAULT;
3556 		return -ENOSPC;
3557 	}
3558 
3559 	return 0;
3560 }
3561 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3562 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3563 					  struct bpf_link_info *info)
3564 {
3565 	struct bpf_raw_tp_link *raw_tp_link =
3566 		container_of(link, struct bpf_raw_tp_link, link);
3567 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3568 	const char *tp_name = raw_tp_link->btp->tp->name;
3569 	u32 ulen = info->raw_tracepoint.tp_name_len;
3570 	size_t tp_len = strlen(tp_name);
3571 
3572 	if (!ulen ^ !ubuf)
3573 		return -EINVAL;
3574 
3575 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3576 
3577 	if (!ubuf)
3578 		return 0;
3579 
3580 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3581 }
3582 
3583 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3584 	.release = bpf_raw_tp_link_release,
3585 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3586 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3587 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3588 };
3589 
3590 #ifdef CONFIG_PERF_EVENTS
3591 struct bpf_perf_link {
3592 	struct bpf_link link;
3593 	struct file *perf_file;
3594 };
3595 
bpf_perf_link_release(struct bpf_link * link)3596 static void bpf_perf_link_release(struct bpf_link *link)
3597 {
3598 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3599 	struct perf_event *event = perf_link->perf_file->private_data;
3600 
3601 	perf_event_free_bpf_prog(event);
3602 	fput(perf_link->perf_file);
3603 }
3604 
bpf_perf_link_dealloc(struct bpf_link * link)3605 static void bpf_perf_link_dealloc(struct bpf_link *link)
3606 {
3607 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3608 
3609 	kfree(perf_link);
3610 }
3611 
bpf_perf_link_fill_common(const struct perf_event * event,char __user * uname,u32 ulen,u64 * probe_offset,u64 * probe_addr,u32 * fd_type,unsigned long * missed)3612 static int bpf_perf_link_fill_common(const struct perf_event *event,
3613 				     char __user *uname, u32 ulen,
3614 				     u64 *probe_offset, u64 *probe_addr,
3615 				     u32 *fd_type, unsigned long *missed)
3616 {
3617 	const char *buf;
3618 	u32 prog_id;
3619 	size_t len;
3620 	int err;
3621 
3622 	if (!ulen ^ !uname)
3623 		return -EINVAL;
3624 
3625 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3626 				      probe_offset, probe_addr, missed);
3627 	if (err)
3628 		return err;
3629 	if (!uname)
3630 		return 0;
3631 	if (buf) {
3632 		len = strlen(buf);
3633 		err = bpf_copy_to_user(uname, buf, ulen, len);
3634 		if (err)
3635 			return err;
3636 	} else {
3637 		char zero = '\0';
3638 
3639 		if (put_user(zero, uname))
3640 			return -EFAULT;
3641 	}
3642 	return 0;
3643 }
3644 
3645 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3646 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3647 				     struct bpf_link_info *info)
3648 {
3649 	unsigned long missed;
3650 	char __user *uname;
3651 	u64 addr, offset;
3652 	u32 ulen, type;
3653 	int err;
3654 
3655 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3656 	ulen = info->perf_event.kprobe.name_len;
3657 	err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr,
3658 					&type, &missed);
3659 	if (err)
3660 		return err;
3661 	if (type == BPF_FD_TYPE_KRETPROBE)
3662 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3663 	else
3664 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3665 
3666 	info->perf_event.kprobe.offset = offset;
3667 	info->perf_event.kprobe.missed = missed;
3668 	if (!kallsyms_show_value(current_cred()))
3669 		addr = 0;
3670 	info->perf_event.kprobe.addr = addr;
3671 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3672 	return 0;
3673 }
3674 #endif
3675 
3676 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3677 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3678 				     struct bpf_link_info *info)
3679 {
3680 	char __user *uname;
3681 	u64 addr, offset;
3682 	u32 ulen, type;
3683 	int err;
3684 
3685 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3686 	ulen = info->perf_event.uprobe.name_len;
3687 	err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr,
3688 					&type, NULL);
3689 	if (err)
3690 		return err;
3691 
3692 	if (type == BPF_FD_TYPE_URETPROBE)
3693 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3694 	else
3695 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3696 	info->perf_event.uprobe.offset = offset;
3697 	info->perf_event.uprobe.cookie = event->bpf_cookie;
3698 	return 0;
3699 }
3700 #endif
3701 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)3702 static int bpf_perf_link_fill_probe(const struct perf_event *event,
3703 				    struct bpf_link_info *info)
3704 {
3705 #ifdef CONFIG_KPROBE_EVENTS
3706 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
3707 		return bpf_perf_link_fill_kprobe(event, info);
3708 #endif
3709 #ifdef CONFIG_UPROBE_EVENTS
3710 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
3711 		return bpf_perf_link_fill_uprobe(event, info);
3712 #endif
3713 	return -EOPNOTSUPP;
3714 }
3715 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)3716 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
3717 					 struct bpf_link_info *info)
3718 {
3719 	char __user *uname;
3720 	u32 ulen;
3721 
3722 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
3723 	ulen = info->perf_event.tracepoint.name_len;
3724 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
3725 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
3726 	return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL, NULL);
3727 }
3728 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)3729 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
3730 					 struct bpf_link_info *info)
3731 {
3732 	info->perf_event.event.type = event->attr.type;
3733 	info->perf_event.event.config = event->attr.config;
3734 	info->perf_event.event.cookie = event->bpf_cookie;
3735 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
3736 	return 0;
3737 }
3738 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3739 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
3740 					struct bpf_link_info *info)
3741 {
3742 	struct bpf_perf_link *perf_link;
3743 	const struct perf_event *event;
3744 
3745 	perf_link = container_of(link, struct bpf_perf_link, link);
3746 	event = perf_get_event(perf_link->perf_file);
3747 	if (IS_ERR(event))
3748 		return PTR_ERR(event);
3749 
3750 	switch (event->prog->type) {
3751 	case BPF_PROG_TYPE_PERF_EVENT:
3752 		return bpf_perf_link_fill_perf_event(event, info);
3753 	case BPF_PROG_TYPE_TRACEPOINT:
3754 		return bpf_perf_link_fill_tracepoint(event, info);
3755 	case BPF_PROG_TYPE_KPROBE:
3756 		return bpf_perf_link_fill_probe(event, info);
3757 	default:
3758 		return -EOPNOTSUPP;
3759 	}
3760 }
3761 
3762 static const struct bpf_link_ops bpf_perf_link_lops = {
3763 	.release = bpf_perf_link_release,
3764 	.dealloc = bpf_perf_link_dealloc,
3765 	.fill_link_info = bpf_perf_link_fill_link_info,
3766 };
3767 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3768 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3769 {
3770 	struct bpf_link_primer link_primer;
3771 	struct bpf_perf_link *link;
3772 	struct perf_event *event;
3773 	struct file *perf_file;
3774 	int err;
3775 
3776 	if (attr->link_create.flags)
3777 		return -EINVAL;
3778 
3779 	perf_file = perf_event_get(attr->link_create.target_fd);
3780 	if (IS_ERR(perf_file))
3781 		return PTR_ERR(perf_file);
3782 
3783 	link = kzalloc(sizeof(*link), GFP_USER);
3784 	if (!link) {
3785 		err = -ENOMEM;
3786 		goto out_put_file;
3787 	}
3788 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3789 	link->perf_file = perf_file;
3790 
3791 	err = bpf_link_prime(&link->link, &link_primer);
3792 	if (err) {
3793 		kfree(link);
3794 		goto out_put_file;
3795 	}
3796 
3797 	event = perf_file->private_data;
3798 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3799 	if (err) {
3800 		bpf_link_cleanup(&link_primer);
3801 		goto out_put_file;
3802 	}
3803 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3804 	bpf_prog_inc(prog);
3805 
3806 	return bpf_link_settle(&link_primer);
3807 
3808 out_put_file:
3809 	fput(perf_file);
3810 	return err;
3811 }
3812 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3813 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3814 {
3815 	return -EOPNOTSUPP;
3816 }
3817 #endif /* CONFIG_PERF_EVENTS */
3818 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie)3819 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3820 				  const char __user *user_tp_name, u64 cookie)
3821 {
3822 	struct bpf_link_primer link_primer;
3823 	struct bpf_raw_tp_link *link;
3824 	struct bpf_raw_event_map *btp;
3825 	const char *tp_name;
3826 	char buf[128];
3827 	int err;
3828 
3829 	switch (prog->type) {
3830 	case BPF_PROG_TYPE_TRACING:
3831 	case BPF_PROG_TYPE_EXT:
3832 	case BPF_PROG_TYPE_LSM:
3833 		if (user_tp_name)
3834 			/* The attach point for this category of programs
3835 			 * should be specified via btf_id during program load.
3836 			 */
3837 			return -EINVAL;
3838 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3839 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3840 			tp_name = prog->aux->attach_func_name;
3841 			break;
3842 		}
3843 		return bpf_tracing_prog_attach(prog, 0, 0, 0);
3844 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3845 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3846 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3847 			return -EFAULT;
3848 		buf[sizeof(buf) - 1] = 0;
3849 		tp_name = buf;
3850 		break;
3851 	default:
3852 		return -EINVAL;
3853 	}
3854 
3855 	btp = bpf_get_raw_tracepoint(tp_name);
3856 	if (!btp)
3857 		return -ENOENT;
3858 
3859 	link = kzalloc(sizeof(*link), GFP_USER);
3860 	if (!link) {
3861 		err = -ENOMEM;
3862 		goto out_put_btp;
3863 	}
3864 	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3865 		      &bpf_raw_tp_link_lops, prog);
3866 	link->btp = btp;
3867 	link->cookie = cookie;
3868 
3869 	err = bpf_link_prime(&link->link, &link_primer);
3870 	if (err) {
3871 		kfree(link);
3872 		goto out_put_btp;
3873 	}
3874 
3875 	err = bpf_probe_register(link->btp, link);
3876 	if (err) {
3877 		bpf_link_cleanup(&link_primer);
3878 		goto out_put_btp;
3879 	}
3880 
3881 	return bpf_link_settle(&link_primer);
3882 
3883 out_put_btp:
3884 	bpf_put_raw_tracepoint(btp);
3885 	return err;
3886 }
3887 
3888 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
3889 
bpf_raw_tracepoint_open(const union bpf_attr * attr)3890 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
3891 {
3892 	struct bpf_prog *prog;
3893 	void __user *tp_name;
3894 	__u64 cookie;
3895 	int fd;
3896 
3897 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
3898 		return -EINVAL;
3899 
3900 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
3901 	if (IS_ERR(prog))
3902 		return PTR_ERR(prog);
3903 
3904 	tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
3905 	cookie = attr->raw_tracepoint.cookie;
3906 	fd = bpf_raw_tp_link_attach(prog, tp_name, cookie);
3907 	if (fd < 0)
3908 		bpf_prog_put(prog);
3909 	return fd;
3910 }
3911 
3912 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)3913 attach_type_to_prog_type(enum bpf_attach_type attach_type)
3914 {
3915 	switch (attach_type) {
3916 	case BPF_CGROUP_INET_INGRESS:
3917 	case BPF_CGROUP_INET_EGRESS:
3918 		return BPF_PROG_TYPE_CGROUP_SKB;
3919 	case BPF_CGROUP_INET_SOCK_CREATE:
3920 	case BPF_CGROUP_INET_SOCK_RELEASE:
3921 	case BPF_CGROUP_INET4_POST_BIND:
3922 	case BPF_CGROUP_INET6_POST_BIND:
3923 		return BPF_PROG_TYPE_CGROUP_SOCK;
3924 	case BPF_CGROUP_INET4_BIND:
3925 	case BPF_CGROUP_INET6_BIND:
3926 	case BPF_CGROUP_INET4_CONNECT:
3927 	case BPF_CGROUP_INET6_CONNECT:
3928 	case BPF_CGROUP_UNIX_CONNECT:
3929 	case BPF_CGROUP_INET4_GETPEERNAME:
3930 	case BPF_CGROUP_INET6_GETPEERNAME:
3931 	case BPF_CGROUP_UNIX_GETPEERNAME:
3932 	case BPF_CGROUP_INET4_GETSOCKNAME:
3933 	case BPF_CGROUP_INET6_GETSOCKNAME:
3934 	case BPF_CGROUP_UNIX_GETSOCKNAME:
3935 	case BPF_CGROUP_UDP4_SENDMSG:
3936 	case BPF_CGROUP_UDP6_SENDMSG:
3937 	case BPF_CGROUP_UNIX_SENDMSG:
3938 	case BPF_CGROUP_UDP4_RECVMSG:
3939 	case BPF_CGROUP_UDP6_RECVMSG:
3940 	case BPF_CGROUP_UNIX_RECVMSG:
3941 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
3942 	case BPF_CGROUP_SOCK_OPS:
3943 		return BPF_PROG_TYPE_SOCK_OPS;
3944 	case BPF_CGROUP_DEVICE:
3945 		return BPF_PROG_TYPE_CGROUP_DEVICE;
3946 	case BPF_SK_MSG_VERDICT:
3947 		return BPF_PROG_TYPE_SK_MSG;
3948 	case BPF_SK_SKB_STREAM_PARSER:
3949 	case BPF_SK_SKB_STREAM_VERDICT:
3950 	case BPF_SK_SKB_VERDICT:
3951 		return BPF_PROG_TYPE_SK_SKB;
3952 	case BPF_LIRC_MODE2:
3953 		return BPF_PROG_TYPE_LIRC_MODE2;
3954 	case BPF_FLOW_DISSECTOR:
3955 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
3956 	case BPF_CGROUP_SYSCTL:
3957 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
3958 	case BPF_CGROUP_GETSOCKOPT:
3959 	case BPF_CGROUP_SETSOCKOPT:
3960 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
3961 	case BPF_TRACE_ITER:
3962 	case BPF_TRACE_RAW_TP:
3963 	case BPF_TRACE_FENTRY:
3964 	case BPF_TRACE_FEXIT:
3965 	case BPF_MODIFY_RETURN:
3966 		return BPF_PROG_TYPE_TRACING;
3967 	case BPF_LSM_MAC:
3968 		return BPF_PROG_TYPE_LSM;
3969 	case BPF_SK_LOOKUP:
3970 		return BPF_PROG_TYPE_SK_LOOKUP;
3971 	case BPF_XDP:
3972 		return BPF_PROG_TYPE_XDP;
3973 	case BPF_LSM_CGROUP:
3974 		return BPF_PROG_TYPE_LSM;
3975 	case BPF_TCX_INGRESS:
3976 	case BPF_TCX_EGRESS:
3977 	case BPF_NETKIT_PRIMARY:
3978 	case BPF_NETKIT_PEER:
3979 		return BPF_PROG_TYPE_SCHED_CLS;
3980 	default:
3981 		return BPF_PROG_TYPE_UNSPEC;
3982 	}
3983 }
3984 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)3985 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
3986 					     enum bpf_attach_type attach_type)
3987 {
3988 	enum bpf_prog_type ptype;
3989 
3990 	switch (prog->type) {
3991 	case BPF_PROG_TYPE_CGROUP_SOCK:
3992 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
3993 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
3994 	case BPF_PROG_TYPE_SK_LOOKUP:
3995 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
3996 	case BPF_PROG_TYPE_CGROUP_SKB:
3997 		if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
3998 			/* cg-skb progs can be loaded by unpriv user.
3999 			 * check permissions at attach time.
4000 			 */
4001 			return -EPERM;
4002 
4003 		ptype = attach_type_to_prog_type(attach_type);
4004 		if (prog->type != ptype)
4005 			return -EINVAL;
4006 
4007 		return prog->enforce_expected_attach_type &&
4008 			prog->expected_attach_type != attach_type ?
4009 			-EINVAL : 0;
4010 	case BPF_PROG_TYPE_EXT:
4011 		return 0;
4012 	case BPF_PROG_TYPE_NETFILTER:
4013 		if (attach_type != BPF_NETFILTER)
4014 			return -EINVAL;
4015 		return 0;
4016 	case BPF_PROG_TYPE_PERF_EVENT:
4017 	case BPF_PROG_TYPE_TRACEPOINT:
4018 		if (attach_type != BPF_PERF_EVENT)
4019 			return -EINVAL;
4020 		return 0;
4021 	case BPF_PROG_TYPE_KPROBE:
4022 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4023 		    attach_type != BPF_TRACE_KPROBE_MULTI)
4024 			return -EINVAL;
4025 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4026 		    attach_type != BPF_TRACE_KPROBE_SESSION)
4027 			return -EINVAL;
4028 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4029 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4030 			return -EINVAL;
4031 		if (attach_type != BPF_PERF_EVENT &&
4032 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
4033 		    attach_type != BPF_TRACE_KPROBE_SESSION &&
4034 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4035 			return -EINVAL;
4036 		return 0;
4037 	case BPF_PROG_TYPE_SCHED_CLS:
4038 		if (attach_type != BPF_TCX_INGRESS &&
4039 		    attach_type != BPF_TCX_EGRESS &&
4040 		    attach_type != BPF_NETKIT_PRIMARY &&
4041 		    attach_type != BPF_NETKIT_PEER)
4042 			return -EINVAL;
4043 		return 0;
4044 	default:
4045 		ptype = attach_type_to_prog_type(attach_type);
4046 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4047 			return -EINVAL;
4048 		return 0;
4049 	}
4050 }
4051 
4052 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4053 
4054 #define BPF_F_ATTACH_MASK_BASE	\
4055 	(BPF_F_ALLOW_OVERRIDE |	\
4056 	 BPF_F_ALLOW_MULTI |	\
4057 	 BPF_F_REPLACE)
4058 
4059 #define BPF_F_ATTACH_MASK_MPROG	\
4060 	(BPF_F_REPLACE |	\
4061 	 BPF_F_BEFORE |		\
4062 	 BPF_F_AFTER |		\
4063 	 BPF_F_ID |		\
4064 	 BPF_F_LINK)
4065 
bpf_prog_attach(const union bpf_attr * attr)4066 static int bpf_prog_attach(const union bpf_attr *attr)
4067 {
4068 	enum bpf_prog_type ptype;
4069 	struct bpf_prog *prog;
4070 	int ret;
4071 
4072 	if (CHECK_ATTR(BPF_PROG_ATTACH))
4073 		return -EINVAL;
4074 
4075 	ptype = attach_type_to_prog_type(attr->attach_type);
4076 	if (ptype == BPF_PROG_TYPE_UNSPEC)
4077 		return -EINVAL;
4078 	if (bpf_mprog_supported(ptype)) {
4079 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4080 			return -EINVAL;
4081 	} else {
4082 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4083 			return -EINVAL;
4084 		if (attr->relative_fd ||
4085 		    attr->expected_revision)
4086 			return -EINVAL;
4087 	}
4088 
4089 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4090 	if (IS_ERR(prog))
4091 		return PTR_ERR(prog);
4092 
4093 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4094 		bpf_prog_put(prog);
4095 		return -EINVAL;
4096 	}
4097 
4098 	switch (ptype) {
4099 	case BPF_PROG_TYPE_SK_SKB:
4100 	case BPF_PROG_TYPE_SK_MSG:
4101 		ret = sock_map_get_from_fd(attr, prog);
4102 		break;
4103 	case BPF_PROG_TYPE_LIRC_MODE2:
4104 		ret = lirc_prog_attach(attr, prog);
4105 		break;
4106 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4107 		ret = netns_bpf_prog_attach(attr, prog);
4108 		break;
4109 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4110 	case BPF_PROG_TYPE_CGROUP_SKB:
4111 	case BPF_PROG_TYPE_CGROUP_SOCK:
4112 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4113 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4114 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4115 	case BPF_PROG_TYPE_SOCK_OPS:
4116 	case BPF_PROG_TYPE_LSM:
4117 		if (ptype == BPF_PROG_TYPE_LSM &&
4118 		    prog->expected_attach_type != BPF_LSM_CGROUP)
4119 			ret = -EINVAL;
4120 		else
4121 			ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4122 		break;
4123 	case BPF_PROG_TYPE_SCHED_CLS:
4124 		if (attr->attach_type == BPF_TCX_INGRESS ||
4125 		    attr->attach_type == BPF_TCX_EGRESS)
4126 			ret = tcx_prog_attach(attr, prog);
4127 		else
4128 			ret = netkit_prog_attach(attr, prog);
4129 		break;
4130 	default:
4131 		ret = -EINVAL;
4132 	}
4133 
4134 	if (ret)
4135 		bpf_prog_put(prog);
4136 	return ret;
4137 }
4138 
4139 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4140 
bpf_prog_detach(const union bpf_attr * attr)4141 static int bpf_prog_detach(const union bpf_attr *attr)
4142 {
4143 	struct bpf_prog *prog = NULL;
4144 	enum bpf_prog_type ptype;
4145 	int ret;
4146 
4147 	if (CHECK_ATTR(BPF_PROG_DETACH))
4148 		return -EINVAL;
4149 
4150 	ptype = attach_type_to_prog_type(attr->attach_type);
4151 	if (bpf_mprog_supported(ptype)) {
4152 		if (ptype == BPF_PROG_TYPE_UNSPEC)
4153 			return -EINVAL;
4154 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4155 			return -EINVAL;
4156 		if (attr->attach_bpf_fd) {
4157 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4158 			if (IS_ERR(prog))
4159 				return PTR_ERR(prog);
4160 		}
4161 	} else if (attr->attach_flags ||
4162 		   attr->relative_fd ||
4163 		   attr->expected_revision) {
4164 		return -EINVAL;
4165 	}
4166 
4167 	switch (ptype) {
4168 	case BPF_PROG_TYPE_SK_MSG:
4169 	case BPF_PROG_TYPE_SK_SKB:
4170 		ret = sock_map_prog_detach(attr, ptype);
4171 		break;
4172 	case BPF_PROG_TYPE_LIRC_MODE2:
4173 		ret = lirc_prog_detach(attr);
4174 		break;
4175 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4176 		ret = netns_bpf_prog_detach(attr, ptype);
4177 		break;
4178 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4179 	case BPF_PROG_TYPE_CGROUP_SKB:
4180 	case BPF_PROG_TYPE_CGROUP_SOCK:
4181 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4182 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4183 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4184 	case BPF_PROG_TYPE_SOCK_OPS:
4185 	case BPF_PROG_TYPE_LSM:
4186 		ret = cgroup_bpf_prog_detach(attr, ptype);
4187 		break;
4188 	case BPF_PROG_TYPE_SCHED_CLS:
4189 		if (attr->attach_type == BPF_TCX_INGRESS ||
4190 		    attr->attach_type == BPF_TCX_EGRESS)
4191 			ret = tcx_prog_detach(attr, prog);
4192 		else
4193 			ret = netkit_prog_detach(attr, prog);
4194 		break;
4195 	default:
4196 		ret = -EINVAL;
4197 	}
4198 
4199 	if (prog)
4200 		bpf_prog_put(prog);
4201 	return ret;
4202 }
4203 
4204 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4205 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4206 static int bpf_prog_query(const union bpf_attr *attr,
4207 			  union bpf_attr __user *uattr)
4208 {
4209 	if (!bpf_net_capable())
4210 		return -EPERM;
4211 	if (CHECK_ATTR(BPF_PROG_QUERY))
4212 		return -EINVAL;
4213 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4214 		return -EINVAL;
4215 
4216 	switch (attr->query.attach_type) {
4217 	case BPF_CGROUP_INET_INGRESS:
4218 	case BPF_CGROUP_INET_EGRESS:
4219 	case BPF_CGROUP_INET_SOCK_CREATE:
4220 	case BPF_CGROUP_INET_SOCK_RELEASE:
4221 	case BPF_CGROUP_INET4_BIND:
4222 	case BPF_CGROUP_INET6_BIND:
4223 	case BPF_CGROUP_INET4_POST_BIND:
4224 	case BPF_CGROUP_INET6_POST_BIND:
4225 	case BPF_CGROUP_INET4_CONNECT:
4226 	case BPF_CGROUP_INET6_CONNECT:
4227 	case BPF_CGROUP_UNIX_CONNECT:
4228 	case BPF_CGROUP_INET4_GETPEERNAME:
4229 	case BPF_CGROUP_INET6_GETPEERNAME:
4230 	case BPF_CGROUP_UNIX_GETPEERNAME:
4231 	case BPF_CGROUP_INET4_GETSOCKNAME:
4232 	case BPF_CGROUP_INET6_GETSOCKNAME:
4233 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4234 	case BPF_CGROUP_UDP4_SENDMSG:
4235 	case BPF_CGROUP_UDP6_SENDMSG:
4236 	case BPF_CGROUP_UNIX_SENDMSG:
4237 	case BPF_CGROUP_UDP4_RECVMSG:
4238 	case BPF_CGROUP_UDP6_RECVMSG:
4239 	case BPF_CGROUP_UNIX_RECVMSG:
4240 	case BPF_CGROUP_SOCK_OPS:
4241 	case BPF_CGROUP_DEVICE:
4242 	case BPF_CGROUP_SYSCTL:
4243 	case BPF_CGROUP_GETSOCKOPT:
4244 	case BPF_CGROUP_SETSOCKOPT:
4245 	case BPF_LSM_CGROUP:
4246 		return cgroup_bpf_prog_query(attr, uattr);
4247 	case BPF_LIRC_MODE2:
4248 		return lirc_prog_query(attr, uattr);
4249 	case BPF_FLOW_DISSECTOR:
4250 	case BPF_SK_LOOKUP:
4251 		return netns_bpf_prog_query(attr, uattr);
4252 	case BPF_SK_SKB_STREAM_PARSER:
4253 	case BPF_SK_SKB_STREAM_VERDICT:
4254 	case BPF_SK_MSG_VERDICT:
4255 	case BPF_SK_SKB_VERDICT:
4256 		return sock_map_bpf_prog_query(attr, uattr);
4257 	case BPF_TCX_INGRESS:
4258 	case BPF_TCX_EGRESS:
4259 		return tcx_prog_query(attr, uattr);
4260 	case BPF_NETKIT_PRIMARY:
4261 	case BPF_NETKIT_PEER:
4262 		return netkit_prog_query(attr, uattr);
4263 	default:
4264 		return -EINVAL;
4265 	}
4266 }
4267 
4268 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4269 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4270 static int bpf_prog_test_run(const union bpf_attr *attr,
4271 			     union bpf_attr __user *uattr)
4272 {
4273 	struct bpf_prog *prog;
4274 	int ret = -ENOTSUPP;
4275 
4276 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4277 		return -EINVAL;
4278 
4279 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4280 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4281 		return -EINVAL;
4282 
4283 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4284 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4285 		return -EINVAL;
4286 
4287 	prog = bpf_prog_get(attr->test.prog_fd);
4288 	if (IS_ERR(prog))
4289 		return PTR_ERR(prog);
4290 
4291 	if (prog->aux->ops->test_run)
4292 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4293 
4294 	bpf_prog_put(prog);
4295 	return ret;
4296 }
4297 
4298 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4299 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4300 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4301 			       union bpf_attr __user *uattr,
4302 			       struct idr *idr,
4303 			       spinlock_t *lock)
4304 {
4305 	u32 next_id = attr->start_id;
4306 	int err = 0;
4307 
4308 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4309 		return -EINVAL;
4310 
4311 	if (!capable(CAP_SYS_ADMIN))
4312 		return -EPERM;
4313 
4314 	next_id++;
4315 	spin_lock_bh(lock);
4316 	if (!idr_get_next(idr, &next_id))
4317 		err = -ENOENT;
4318 	spin_unlock_bh(lock);
4319 
4320 	if (!err)
4321 		err = put_user(next_id, &uattr->next_id);
4322 
4323 	return err;
4324 }
4325 
bpf_map_get_curr_or_next(u32 * id)4326 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4327 {
4328 	struct bpf_map *map;
4329 
4330 	spin_lock_bh(&map_idr_lock);
4331 again:
4332 	map = idr_get_next(&map_idr, id);
4333 	if (map) {
4334 		map = __bpf_map_inc_not_zero(map, false);
4335 		if (IS_ERR(map)) {
4336 			(*id)++;
4337 			goto again;
4338 		}
4339 	}
4340 	spin_unlock_bh(&map_idr_lock);
4341 
4342 	return map;
4343 }
4344 
bpf_prog_get_curr_or_next(u32 * id)4345 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4346 {
4347 	struct bpf_prog *prog;
4348 
4349 	spin_lock_bh(&prog_idr_lock);
4350 again:
4351 	prog = idr_get_next(&prog_idr, id);
4352 	if (prog) {
4353 		prog = bpf_prog_inc_not_zero(prog);
4354 		if (IS_ERR(prog)) {
4355 			(*id)++;
4356 			goto again;
4357 		}
4358 	}
4359 	spin_unlock_bh(&prog_idr_lock);
4360 
4361 	return prog;
4362 }
4363 
4364 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4365 
bpf_prog_by_id(u32 id)4366 struct bpf_prog *bpf_prog_by_id(u32 id)
4367 {
4368 	struct bpf_prog *prog;
4369 
4370 	if (!id)
4371 		return ERR_PTR(-ENOENT);
4372 
4373 	spin_lock_bh(&prog_idr_lock);
4374 	prog = idr_find(&prog_idr, id);
4375 	if (prog)
4376 		prog = bpf_prog_inc_not_zero(prog);
4377 	else
4378 		prog = ERR_PTR(-ENOENT);
4379 	spin_unlock_bh(&prog_idr_lock);
4380 	return prog;
4381 }
4382 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4383 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4384 {
4385 	struct bpf_prog *prog;
4386 	u32 id = attr->prog_id;
4387 	int fd;
4388 
4389 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4390 		return -EINVAL;
4391 
4392 	if (!capable(CAP_SYS_ADMIN))
4393 		return -EPERM;
4394 
4395 	prog = bpf_prog_by_id(id);
4396 	if (IS_ERR(prog))
4397 		return PTR_ERR(prog);
4398 
4399 	fd = bpf_prog_new_fd(prog);
4400 	if (fd < 0)
4401 		bpf_prog_put(prog);
4402 
4403 	return fd;
4404 }
4405 
4406 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4407 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4408 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4409 {
4410 	struct bpf_map *map;
4411 	u32 id = attr->map_id;
4412 	int f_flags;
4413 	int fd;
4414 
4415 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4416 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4417 		return -EINVAL;
4418 
4419 	if (!capable(CAP_SYS_ADMIN))
4420 		return -EPERM;
4421 
4422 	f_flags = bpf_get_file_flag(attr->open_flags);
4423 	if (f_flags < 0)
4424 		return f_flags;
4425 
4426 	spin_lock_bh(&map_idr_lock);
4427 	map = idr_find(&map_idr, id);
4428 	if (map)
4429 		map = __bpf_map_inc_not_zero(map, true);
4430 	else
4431 		map = ERR_PTR(-ENOENT);
4432 	spin_unlock_bh(&map_idr_lock);
4433 
4434 	if (IS_ERR(map))
4435 		return PTR_ERR(map);
4436 
4437 	fd = bpf_map_new_fd(map, f_flags);
4438 	if (fd < 0)
4439 		bpf_map_put_with_uref(map);
4440 
4441 	return fd;
4442 }
4443 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4444 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4445 					      unsigned long addr, u32 *off,
4446 					      u32 *type)
4447 {
4448 	const struct bpf_map *map;
4449 	int i;
4450 
4451 	mutex_lock(&prog->aux->used_maps_mutex);
4452 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4453 		map = prog->aux->used_maps[i];
4454 		if (map == (void *)addr) {
4455 			*type = BPF_PSEUDO_MAP_FD;
4456 			goto out;
4457 		}
4458 		if (!map->ops->map_direct_value_meta)
4459 			continue;
4460 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4461 			*type = BPF_PSEUDO_MAP_VALUE;
4462 			goto out;
4463 		}
4464 	}
4465 	map = NULL;
4466 
4467 out:
4468 	mutex_unlock(&prog->aux->used_maps_mutex);
4469 	return map;
4470 }
4471 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4472 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4473 					      const struct cred *f_cred)
4474 {
4475 	const struct bpf_map *map;
4476 	struct bpf_insn *insns;
4477 	u32 off, type;
4478 	u64 imm;
4479 	u8 code;
4480 	int i;
4481 
4482 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4483 			GFP_USER);
4484 	if (!insns)
4485 		return insns;
4486 
4487 	for (i = 0; i < prog->len; i++) {
4488 		code = insns[i].code;
4489 
4490 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4491 			insns[i].code = BPF_JMP | BPF_CALL;
4492 			insns[i].imm = BPF_FUNC_tail_call;
4493 			/* fall-through */
4494 		}
4495 		if (code == (BPF_JMP | BPF_CALL) ||
4496 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4497 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4498 				insns[i].code = BPF_JMP | BPF_CALL;
4499 			if (!bpf_dump_raw_ok(f_cred))
4500 				insns[i].imm = 0;
4501 			continue;
4502 		}
4503 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4504 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4505 			continue;
4506 		}
4507 
4508 		if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4509 		     BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4510 			insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4511 			continue;
4512 		}
4513 
4514 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4515 			continue;
4516 
4517 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4518 		map = bpf_map_from_imm(prog, imm, &off, &type);
4519 		if (map) {
4520 			insns[i].src_reg = type;
4521 			insns[i].imm = map->id;
4522 			insns[i + 1].imm = off;
4523 			continue;
4524 		}
4525 	}
4526 
4527 	return insns;
4528 }
4529 
set_info_rec_size(struct bpf_prog_info * info)4530 static int set_info_rec_size(struct bpf_prog_info *info)
4531 {
4532 	/*
4533 	 * Ensure info.*_rec_size is the same as kernel expected size
4534 	 *
4535 	 * or
4536 	 *
4537 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4538 	 * zero.  In this case, the kernel will set the expected
4539 	 * _rec_size back to the info.
4540 	 */
4541 
4542 	if ((info->nr_func_info || info->func_info_rec_size) &&
4543 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4544 		return -EINVAL;
4545 
4546 	if ((info->nr_line_info || info->line_info_rec_size) &&
4547 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
4548 		return -EINVAL;
4549 
4550 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4551 	    info->jited_line_info_rec_size != sizeof(__u64))
4552 		return -EINVAL;
4553 
4554 	info->func_info_rec_size = sizeof(struct bpf_func_info);
4555 	info->line_info_rec_size = sizeof(struct bpf_line_info);
4556 	info->jited_line_info_rec_size = sizeof(__u64);
4557 
4558 	return 0;
4559 }
4560 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4561 static int bpf_prog_get_info_by_fd(struct file *file,
4562 				   struct bpf_prog *prog,
4563 				   const union bpf_attr *attr,
4564 				   union bpf_attr __user *uattr)
4565 {
4566 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4567 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4568 	struct bpf_prog_info info;
4569 	u32 info_len = attr->info.info_len;
4570 	struct bpf_prog_kstats stats;
4571 	char __user *uinsns;
4572 	u32 ulen;
4573 	int err;
4574 
4575 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4576 	if (err)
4577 		return err;
4578 	info_len = min_t(u32, sizeof(info), info_len);
4579 
4580 	memset(&info, 0, sizeof(info));
4581 	if (copy_from_user(&info, uinfo, info_len))
4582 		return -EFAULT;
4583 
4584 	info.type = prog->type;
4585 	info.id = prog->aux->id;
4586 	info.load_time = prog->aux->load_time;
4587 	info.created_by_uid = from_kuid_munged(current_user_ns(),
4588 					       prog->aux->user->uid);
4589 	info.gpl_compatible = prog->gpl_compatible;
4590 
4591 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
4592 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
4593 
4594 	mutex_lock(&prog->aux->used_maps_mutex);
4595 	ulen = info.nr_map_ids;
4596 	info.nr_map_ids = prog->aux->used_map_cnt;
4597 	ulen = min_t(u32, info.nr_map_ids, ulen);
4598 	if (ulen) {
4599 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
4600 		u32 i;
4601 
4602 		for (i = 0; i < ulen; i++)
4603 			if (put_user(prog->aux->used_maps[i]->id,
4604 				     &user_map_ids[i])) {
4605 				mutex_unlock(&prog->aux->used_maps_mutex);
4606 				return -EFAULT;
4607 			}
4608 	}
4609 	mutex_unlock(&prog->aux->used_maps_mutex);
4610 
4611 	err = set_info_rec_size(&info);
4612 	if (err)
4613 		return err;
4614 
4615 	bpf_prog_get_stats(prog, &stats);
4616 	info.run_time_ns = stats.nsecs;
4617 	info.run_cnt = stats.cnt;
4618 	info.recursion_misses = stats.misses;
4619 
4620 	info.verified_insns = prog->aux->verified_insns;
4621 
4622 	if (!bpf_capable()) {
4623 		info.jited_prog_len = 0;
4624 		info.xlated_prog_len = 0;
4625 		info.nr_jited_ksyms = 0;
4626 		info.nr_jited_func_lens = 0;
4627 		info.nr_func_info = 0;
4628 		info.nr_line_info = 0;
4629 		info.nr_jited_line_info = 0;
4630 		goto done;
4631 	}
4632 
4633 	ulen = info.xlated_prog_len;
4634 	info.xlated_prog_len = bpf_prog_insn_size(prog);
4635 	if (info.xlated_prog_len && ulen) {
4636 		struct bpf_insn *insns_sanitized;
4637 		bool fault;
4638 
4639 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
4640 			info.xlated_prog_insns = 0;
4641 			goto done;
4642 		}
4643 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
4644 		if (!insns_sanitized)
4645 			return -ENOMEM;
4646 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
4647 		ulen = min_t(u32, info.xlated_prog_len, ulen);
4648 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
4649 		kfree(insns_sanitized);
4650 		if (fault)
4651 			return -EFAULT;
4652 	}
4653 
4654 	if (bpf_prog_is_offloaded(prog->aux)) {
4655 		err = bpf_prog_offload_info_fill(&info, prog);
4656 		if (err)
4657 			return err;
4658 		goto done;
4659 	}
4660 
4661 	/* NOTE: the following code is supposed to be skipped for offload.
4662 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
4663 	 * for offload.
4664 	 */
4665 	ulen = info.jited_prog_len;
4666 	if (prog->aux->func_cnt) {
4667 		u32 i;
4668 
4669 		info.jited_prog_len = 0;
4670 		for (i = 0; i < prog->aux->func_cnt; i++)
4671 			info.jited_prog_len += prog->aux->func[i]->jited_len;
4672 	} else {
4673 		info.jited_prog_len = prog->jited_len;
4674 	}
4675 
4676 	if (info.jited_prog_len && ulen) {
4677 		if (bpf_dump_raw_ok(file->f_cred)) {
4678 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
4679 			ulen = min_t(u32, info.jited_prog_len, ulen);
4680 
4681 			/* for multi-function programs, copy the JITed
4682 			 * instructions for all the functions
4683 			 */
4684 			if (prog->aux->func_cnt) {
4685 				u32 len, free, i;
4686 				u8 *img;
4687 
4688 				free = ulen;
4689 				for (i = 0; i < prog->aux->func_cnt; i++) {
4690 					len = prog->aux->func[i]->jited_len;
4691 					len = min_t(u32, len, free);
4692 					img = (u8 *) prog->aux->func[i]->bpf_func;
4693 					if (copy_to_user(uinsns, img, len))
4694 						return -EFAULT;
4695 					uinsns += len;
4696 					free -= len;
4697 					if (!free)
4698 						break;
4699 				}
4700 			} else {
4701 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
4702 					return -EFAULT;
4703 			}
4704 		} else {
4705 			info.jited_prog_insns = 0;
4706 		}
4707 	}
4708 
4709 	ulen = info.nr_jited_ksyms;
4710 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4711 	if (ulen) {
4712 		if (bpf_dump_raw_ok(file->f_cred)) {
4713 			unsigned long ksym_addr;
4714 			u64 __user *user_ksyms;
4715 			u32 i;
4716 
4717 			/* copy the address of the kernel symbol
4718 			 * corresponding to each function
4719 			 */
4720 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4721 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4722 			if (prog->aux->func_cnt) {
4723 				for (i = 0; i < ulen; i++) {
4724 					ksym_addr = (unsigned long)
4725 						prog->aux->func[i]->bpf_func;
4726 					if (put_user((u64) ksym_addr,
4727 						     &user_ksyms[i]))
4728 						return -EFAULT;
4729 				}
4730 			} else {
4731 				ksym_addr = (unsigned long) prog->bpf_func;
4732 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
4733 					return -EFAULT;
4734 			}
4735 		} else {
4736 			info.jited_ksyms = 0;
4737 		}
4738 	}
4739 
4740 	ulen = info.nr_jited_func_lens;
4741 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4742 	if (ulen) {
4743 		if (bpf_dump_raw_ok(file->f_cred)) {
4744 			u32 __user *user_lens;
4745 			u32 func_len, i;
4746 
4747 			/* copy the JITed image lengths for each function */
4748 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4749 			user_lens = u64_to_user_ptr(info.jited_func_lens);
4750 			if (prog->aux->func_cnt) {
4751 				for (i = 0; i < ulen; i++) {
4752 					func_len =
4753 						prog->aux->func[i]->jited_len;
4754 					if (put_user(func_len, &user_lens[i]))
4755 						return -EFAULT;
4756 				}
4757 			} else {
4758 				func_len = prog->jited_len;
4759 				if (put_user(func_len, &user_lens[0]))
4760 					return -EFAULT;
4761 			}
4762 		} else {
4763 			info.jited_func_lens = 0;
4764 		}
4765 	}
4766 
4767 	if (prog->aux->btf)
4768 		info.btf_id = btf_obj_id(prog->aux->btf);
4769 	info.attach_btf_id = prog->aux->attach_btf_id;
4770 	if (attach_btf)
4771 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
4772 
4773 	ulen = info.nr_func_info;
4774 	info.nr_func_info = prog->aux->func_info_cnt;
4775 	if (info.nr_func_info && ulen) {
4776 		char __user *user_finfo;
4777 
4778 		user_finfo = u64_to_user_ptr(info.func_info);
4779 		ulen = min_t(u32, info.nr_func_info, ulen);
4780 		if (copy_to_user(user_finfo, prog->aux->func_info,
4781 				 info.func_info_rec_size * ulen))
4782 			return -EFAULT;
4783 	}
4784 
4785 	ulen = info.nr_line_info;
4786 	info.nr_line_info = prog->aux->nr_linfo;
4787 	if (info.nr_line_info && ulen) {
4788 		__u8 __user *user_linfo;
4789 
4790 		user_linfo = u64_to_user_ptr(info.line_info);
4791 		ulen = min_t(u32, info.nr_line_info, ulen);
4792 		if (copy_to_user(user_linfo, prog->aux->linfo,
4793 				 info.line_info_rec_size * ulen))
4794 			return -EFAULT;
4795 	}
4796 
4797 	ulen = info.nr_jited_line_info;
4798 	if (prog->aux->jited_linfo)
4799 		info.nr_jited_line_info = prog->aux->nr_linfo;
4800 	else
4801 		info.nr_jited_line_info = 0;
4802 	if (info.nr_jited_line_info && ulen) {
4803 		if (bpf_dump_raw_ok(file->f_cred)) {
4804 			unsigned long line_addr;
4805 			__u64 __user *user_linfo;
4806 			u32 i;
4807 
4808 			user_linfo = u64_to_user_ptr(info.jited_line_info);
4809 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
4810 			for (i = 0; i < ulen; i++) {
4811 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
4812 				if (put_user((__u64)line_addr, &user_linfo[i]))
4813 					return -EFAULT;
4814 			}
4815 		} else {
4816 			info.jited_line_info = 0;
4817 		}
4818 	}
4819 
4820 	ulen = info.nr_prog_tags;
4821 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4822 	if (ulen) {
4823 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4824 		u32 i;
4825 
4826 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
4827 		ulen = min_t(u32, info.nr_prog_tags, ulen);
4828 		if (prog->aux->func_cnt) {
4829 			for (i = 0; i < ulen; i++) {
4830 				if (copy_to_user(user_prog_tags[i],
4831 						 prog->aux->func[i]->tag,
4832 						 BPF_TAG_SIZE))
4833 					return -EFAULT;
4834 			}
4835 		} else {
4836 			if (copy_to_user(user_prog_tags[0],
4837 					 prog->tag, BPF_TAG_SIZE))
4838 				return -EFAULT;
4839 		}
4840 	}
4841 
4842 done:
4843 	if (copy_to_user(uinfo, &info, info_len) ||
4844 	    put_user(info_len, &uattr->info.info_len))
4845 		return -EFAULT;
4846 
4847 	return 0;
4848 }
4849 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4850 static int bpf_map_get_info_by_fd(struct file *file,
4851 				  struct bpf_map *map,
4852 				  const union bpf_attr *attr,
4853 				  union bpf_attr __user *uattr)
4854 {
4855 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4856 	struct bpf_map_info info;
4857 	u32 info_len = attr->info.info_len;
4858 	int err;
4859 
4860 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4861 	if (err)
4862 		return err;
4863 	info_len = min_t(u32, sizeof(info), info_len);
4864 
4865 	memset(&info, 0, sizeof(info));
4866 	info.type = map->map_type;
4867 	info.id = map->id;
4868 	info.key_size = map->key_size;
4869 	info.value_size = map->value_size;
4870 	info.max_entries = map->max_entries;
4871 	info.map_flags = map->map_flags;
4872 	info.map_extra = map->map_extra;
4873 	memcpy(info.name, map->name, sizeof(map->name));
4874 
4875 	if (map->btf) {
4876 		info.btf_id = btf_obj_id(map->btf);
4877 		info.btf_key_type_id = map->btf_key_type_id;
4878 		info.btf_value_type_id = map->btf_value_type_id;
4879 	}
4880 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
4881 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
4882 		bpf_map_struct_ops_info_fill(&info, map);
4883 
4884 	if (bpf_map_is_offloaded(map)) {
4885 		err = bpf_map_offload_info_fill(&info, map);
4886 		if (err)
4887 			return err;
4888 	}
4889 
4890 	if (copy_to_user(uinfo, &info, info_len) ||
4891 	    put_user(info_len, &uattr->info.info_len))
4892 		return -EFAULT;
4893 
4894 	return 0;
4895 }
4896 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)4897 static int bpf_btf_get_info_by_fd(struct file *file,
4898 				  struct btf *btf,
4899 				  const union bpf_attr *attr,
4900 				  union bpf_attr __user *uattr)
4901 {
4902 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4903 	u32 info_len = attr->info.info_len;
4904 	int err;
4905 
4906 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
4907 	if (err)
4908 		return err;
4909 
4910 	return btf_get_info_by_fd(btf, attr, uattr);
4911 }
4912 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)4913 static int bpf_link_get_info_by_fd(struct file *file,
4914 				  struct bpf_link *link,
4915 				  const union bpf_attr *attr,
4916 				  union bpf_attr __user *uattr)
4917 {
4918 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4919 	struct bpf_link_info info;
4920 	u32 info_len = attr->info.info_len;
4921 	int err;
4922 
4923 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4924 	if (err)
4925 		return err;
4926 	info_len = min_t(u32, sizeof(info), info_len);
4927 
4928 	memset(&info, 0, sizeof(info));
4929 	if (copy_from_user(&info, uinfo, info_len))
4930 		return -EFAULT;
4931 
4932 	info.type = link->type;
4933 	info.id = link->id;
4934 	if (link->prog)
4935 		info.prog_id = link->prog->aux->id;
4936 
4937 	if (link->ops->fill_link_info) {
4938 		err = link->ops->fill_link_info(link, &info);
4939 		if (err)
4940 			return err;
4941 	}
4942 
4943 	if (copy_to_user(uinfo, &info, info_len) ||
4944 	    put_user(info_len, &uattr->info.info_len))
4945 		return -EFAULT;
4946 
4947 	return 0;
4948 }
4949 
4950 
4951 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
4952 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)4953 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
4954 				  union bpf_attr __user *uattr)
4955 {
4956 	int ufd = attr->info.bpf_fd;
4957 	struct fd f;
4958 	int err;
4959 
4960 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
4961 		return -EINVAL;
4962 
4963 	f = fdget(ufd);
4964 	if (!f.file)
4965 		return -EBADFD;
4966 
4967 	if (f.file->f_op == &bpf_prog_fops)
4968 		err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
4969 					      uattr);
4970 	else if (f.file->f_op == &bpf_map_fops)
4971 		err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
4972 					     uattr);
4973 	else if (f.file->f_op == &btf_fops)
4974 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
4975 	else if (f.file->f_op == &bpf_link_fops)
4976 		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
4977 					      attr, uattr);
4978 	else
4979 		err = -EINVAL;
4980 
4981 	fdput(f);
4982 	return err;
4983 }
4984 
4985 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
4986 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)4987 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
4988 {
4989 	struct bpf_token *token = NULL;
4990 
4991 	if (CHECK_ATTR(BPF_BTF_LOAD))
4992 		return -EINVAL;
4993 
4994 	if (attr->btf_flags & ~BPF_F_TOKEN_FD)
4995 		return -EINVAL;
4996 
4997 	if (attr->btf_flags & BPF_F_TOKEN_FD) {
4998 		token = bpf_token_get_from_fd(attr->btf_token_fd);
4999 		if (IS_ERR(token))
5000 			return PTR_ERR(token);
5001 		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5002 			bpf_token_put(token);
5003 			token = NULL;
5004 		}
5005 	}
5006 
5007 	if (!bpf_token_capable(token, CAP_BPF)) {
5008 		bpf_token_put(token);
5009 		return -EPERM;
5010 	}
5011 
5012 	bpf_token_put(token);
5013 
5014 	return btf_new_fd(attr, uattr, uattr_size);
5015 }
5016 
5017 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
5018 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5019 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5020 {
5021 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5022 		return -EINVAL;
5023 
5024 	if (!capable(CAP_SYS_ADMIN))
5025 		return -EPERM;
5026 
5027 	return btf_get_fd_by_id(attr->btf_id);
5028 }
5029 
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)5030 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5031 				    union bpf_attr __user *uattr,
5032 				    u32 prog_id, u32 fd_type,
5033 				    const char *buf, u64 probe_offset,
5034 				    u64 probe_addr)
5035 {
5036 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5037 	u32 len = buf ? strlen(buf) : 0, input_len;
5038 	int err = 0;
5039 
5040 	if (put_user(len, &uattr->task_fd_query.buf_len))
5041 		return -EFAULT;
5042 	input_len = attr->task_fd_query.buf_len;
5043 	if (input_len && ubuf) {
5044 		if (!len) {
5045 			/* nothing to copy, just make ubuf NULL terminated */
5046 			char zero = '\0';
5047 
5048 			if (put_user(zero, ubuf))
5049 				return -EFAULT;
5050 		} else if (input_len >= len + 1) {
5051 			/* ubuf can hold the string with NULL terminator */
5052 			if (copy_to_user(ubuf, buf, len + 1))
5053 				return -EFAULT;
5054 		} else {
5055 			/* ubuf cannot hold the string with NULL terminator,
5056 			 * do a partial copy with NULL terminator.
5057 			 */
5058 			char zero = '\0';
5059 
5060 			err = -ENOSPC;
5061 			if (copy_to_user(ubuf, buf, input_len - 1))
5062 				return -EFAULT;
5063 			if (put_user(zero, ubuf + input_len - 1))
5064 				return -EFAULT;
5065 		}
5066 	}
5067 
5068 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5069 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5070 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5071 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5072 		return -EFAULT;
5073 
5074 	return err;
5075 }
5076 
5077 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5078 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5079 static int bpf_task_fd_query(const union bpf_attr *attr,
5080 			     union bpf_attr __user *uattr)
5081 {
5082 	pid_t pid = attr->task_fd_query.pid;
5083 	u32 fd = attr->task_fd_query.fd;
5084 	const struct perf_event *event;
5085 	struct task_struct *task;
5086 	struct file *file;
5087 	int err;
5088 
5089 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5090 		return -EINVAL;
5091 
5092 	if (!capable(CAP_SYS_ADMIN))
5093 		return -EPERM;
5094 
5095 	if (attr->task_fd_query.flags != 0)
5096 		return -EINVAL;
5097 
5098 	rcu_read_lock();
5099 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5100 	rcu_read_unlock();
5101 	if (!task)
5102 		return -ENOENT;
5103 
5104 	err = 0;
5105 	file = fget_task(task, fd);
5106 	put_task_struct(task);
5107 	if (!file)
5108 		return -EBADF;
5109 
5110 	if (file->f_op == &bpf_link_fops) {
5111 		struct bpf_link *link = file->private_data;
5112 
5113 		if (link->ops == &bpf_raw_tp_link_lops) {
5114 			struct bpf_raw_tp_link *raw_tp =
5115 				container_of(link, struct bpf_raw_tp_link, link);
5116 			struct bpf_raw_event_map *btp = raw_tp->btp;
5117 
5118 			err = bpf_task_fd_query_copy(attr, uattr,
5119 						     raw_tp->link.prog->aux->id,
5120 						     BPF_FD_TYPE_RAW_TRACEPOINT,
5121 						     btp->tp->name, 0, 0);
5122 			goto put_file;
5123 		}
5124 		goto out_not_supp;
5125 	}
5126 
5127 	event = perf_get_event(file);
5128 	if (!IS_ERR(event)) {
5129 		u64 probe_offset, probe_addr;
5130 		u32 prog_id, fd_type;
5131 		const char *buf;
5132 
5133 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5134 					      &buf, &probe_offset,
5135 					      &probe_addr, NULL);
5136 		if (!err)
5137 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5138 						     fd_type, buf,
5139 						     probe_offset,
5140 						     probe_addr);
5141 		goto put_file;
5142 	}
5143 
5144 out_not_supp:
5145 	err = -ENOTSUPP;
5146 put_file:
5147 	fput(file);
5148 	return err;
5149 }
5150 
5151 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5152 
5153 #define BPF_DO_BATCH(fn, ...)			\
5154 	do {					\
5155 		if (!fn) {			\
5156 			err = -ENOTSUPP;	\
5157 			goto err_put;		\
5158 		}				\
5159 		err = fn(__VA_ARGS__);		\
5160 	} while (0)
5161 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5162 static int bpf_map_do_batch(const union bpf_attr *attr,
5163 			    union bpf_attr __user *uattr,
5164 			    int cmd)
5165 {
5166 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
5167 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5168 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5169 	struct bpf_map *map;
5170 	int err, ufd;
5171 	struct fd f;
5172 
5173 	if (CHECK_ATTR(BPF_MAP_BATCH))
5174 		return -EINVAL;
5175 
5176 	ufd = attr->batch.map_fd;
5177 	f = fdget(ufd);
5178 	map = __bpf_map_get(f);
5179 	if (IS_ERR(map))
5180 		return PTR_ERR(map);
5181 	if (has_write)
5182 		bpf_map_write_active_inc(map);
5183 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5184 		err = -EPERM;
5185 		goto err_put;
5186 	}
5187 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5188 		err = -EPERM;
5189 		goto err_put;
5190 	}
5191 
5192 	if (cmd == BPF_MAP_LOOKUP_BATCH)
5193 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5194 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5195 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5196 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5197 		BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr);
5198 	else
5199 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5200 err_put:
5201 	if (has_write) {
5202 		maybe_wait_bpf_programs(map);
5203 		bpf_map_write_active_dec(map);
5204 	}
5205 	fdput(f);
5206 	return err;
5207 }
5208 
5209 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5210 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5211 {
5212 	struct bpf_prog *prog;
5213 	int ret;
5214 
5215 	if (CHECK_ATTR(BPF_LINK_CREATE))
5216 		return -EINVAL;
5217 
5218 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5219 		return bpf_struct_ops_link_create(attr);
5220 
5221 	prog = bpf_prog_get(attr->link_create.prog_fd);
5222 	if (IS_ERR(prog))
5223 		return PTR_ERR(prog);
5224 
5225 	ret = bpf_prog_attach_check_attach_type(prog,
5226 						attr->link_create.attach_type);
5227 	if (ret)
5228 		goto out;
5229 
5230 	switch (prog->type) {
5231 	case BPF_PROG_TYPE_CGROUP_SKB:
5232 	case BPF_PROG_TYPE_CGROUP_SOCK:
5233 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5234 	case BPF_PROG_TYPE_SOCK_OPS:
5235 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5236 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5237 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5238 		ret = cgroup_bpf_link_attach(attr, prog);
5239 		break;
5240 	case BPF_PROG_TYPE_EXT:
5241 		ret = bpf_tracing_prog_attach(prog,
5242 					      attr->link_create.target_fd,
5243 					      attr->link_create.target_btf_id,
5244 					      attr->link_create.tracing.cookie);
5245 		break;
5246 	case BPF_PROG_TYPE_LSM:
5247 	case BPF_PROG_TYPE_TRACING:
5248 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5249 			ret = -EINVAL;
5250 			goto out;
5251 		}
5252 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5253 			ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie);
5254 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5255 			ret = bpf_iter_link_attach(attr, uattr, prog);
5256 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5257 			ret = cgroup_bpf_link_attach(attr, prog);
5258 		else
5259 			ret = bpf_tracing_prog_attach(prog,
5260 						      attr->link_create.target_fd,
5261 						      attr->link_create.target_btf_id,
5262 						      attr->link_create.tracing.cookie);
5263 		break;
5264 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5265 	case BPF_PROG_TYPE_SK_LOOKUP:
5266 		ret = netns_bpf_link_create(attr, prog);
5267 		break;
5268 	case BPF_PROG_TYPE_SK_MSG:
5269 	case BPF_PROG_TYPE_SK_SKB:
5270 		ret = sock_map_link_create(attr, prog);
5271 		break;
5272 #ifdef CONFIG_NET
5273 	case BPF_PROG_TYPE_XDP:
5274 		ret = bpf_xdp_link_attach(attr, prog);
5275 		break;
5276 	case BPF_PROG_TYPE_SCHED_CLS:
5277 		if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5278 		    attr->link_create.attach_type == BPF_TCX_EGRESS)
5279 			ret = tcx_link_attach(attr, prog);
5280 		else
5281 			ret = netkit_link_attach(attr, prog);
5282 		break;
5283 	case BPF_PROG_TYPE_NETFILTER:
5284 		ret = bpf_nf_link_attach(attr, prog);
5285 		break;
5286 #endif
5287 	case BPF_PROG_TYPE_PERF_EVENT:
5288 	case BPF_PROG_TYPE_TRACEPOINT:
5289 		ret = bpf_perf_link_attach(attr, prog);
5290 		break;
5291 	case BPF_PROG_TYPE_KPROBE:
5292 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5293 			ret = bpf_perf_link_attach(attr, prog);
5294 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5295 			 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5296 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5297 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI)
5298 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5299 		break;
5300 	default:
5301 		ret = -EINVAL;
5302 	}
5303 
5304 out:
5305 	if (ret < 0)
5306 		bpf_prog_put(prog);
5307 	return ret;
5308 }
5309 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5310 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5311 {
5312 	struct bpf_map *new_map, *old_map = NULL;
5313 	int ret;
5314 
5315 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5316 	if (IS_ERR(new_map))
5317 		return PTR_ERR(new_map);
5318 
5319 	if (attr->link_update.flags & BPF_F_REPLACE) {
5320 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5321 		if (IS_ERR(old_map)) {
5322 			ret = PTR_ERR(old_map);
5323 			goto out_put;
5324 		}
5325 	} else if (attr->link_update.old_map_fd) {
5326 		ret = -EINVAL;
5327 		goto out_put;
5328 	}
5329 
5330 	ret = link->ops->update_map(link, new_map, old_map);
5331 
5332 	if (old_map)
5333 		bpf_map_put(old_map);
5334 out_put:
5335 	bpf_map_put(new_map);
5336 	return ret;
5337 }
5338 
5339 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5340 
link_update(union bpf_attr * attr)5341 static int link_update(union bpf_attr *attr)
5342 {
5343 	struct bpf_prog *old_prog = NULL, *new_prog;
5344 	struct bpf_link *link;
5345 	u32 flags;
5346 	int ret;
5347 
5348 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5349 		return -EINVAL;
5350 
5351 	flags = attr->link_update.flags;
5352 	if (flags & ~BPF_F_REPLACE)
5353 		return -EINVAL;
5354 
5355 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5356 	if (IS_ERR(link))
5357 		return PTR_ERR(link);
5358 
5359 	if (link->ops->update_map) {
5360 		ret = link_update_map(link, attr);
5361 		goto out_put_link;
5362 	}
5363 
5364 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5365 	if (IS_ERR(new_prog)) {
5366 		ret = PTR_ERR(new_prog);
5367 		goto out_put_link;
5368 	}
5369 
5370 	if (flags & BPF_F_REPLACE) {
5371 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5372 		if (IS_ERR(old_prog)) {
5373 			ret = PTR_ERR(old_prog);
5374 			old_prog = NULL;
5375 			goto out_put_progs;
5376 		}
5377 	} else if (attr->link_update.old_prog_fd) {
5378 		ret = -EINVAL;
5379 		goto out_put_progs;
5380 	}
5381 
5382 	if (link->ops->update_prog)
5383 		ret = link->ops->update_prog(link, new_prog, old_prog);
5384 	else
5385 		ret = -EINVAL;
5386 
5387 out_put_progs:
5388 	if (old_prog)
5389 		bpf_prog_put(old_prog);
5390 	if (ret)
5391 		bpf_prog_put(new_prog);
5392 out_put_link:
5393 	bpf_link_put_direct(link);
5394 	return ret;
5395 }
5396 
5397 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5398 
link_detach(union bpf_attr * attr)5399 static int link_detach(union bpf_attr *attr)
5400 {
5401 	struct bpf_link *link;
5402 	int ret;
5403 
5404 	if (CHECK_ATTR(BPF_LINK_DETACH))
5405 		return -EINVAL;
5406 
5407 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5408 	if (IS_ERR(link))
5409 		return PTR_ERR(link);
5410 
5411 	if (link->ops->detach)
5412 		ret = link->ops->detach(link);
5413 	else
5414 		ret = -EOPNOTSUPP;
5415 
5416 	bpf_link_put_direct(link);
5417 	return ret;
5418 }
5419 
bpf_link_inc_not_zero(struct bpf_link * link)5420 static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5421 {
5422 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5423 }
5424 
bpf_link_by_id(u32 id)5425 struct bpf_link *bpf_link_by_id(u32 id)
5426 {
5427 	struct bpf_link *link;
5428 
5429 	if (!id)
5430 		return ERR_PTR(-ENOENT);
5431 
5432 	spin_lock_bh(&link_idr_lock);
5433 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5434 	link = idr_find(&link_idr, id);
5435 	if (link) {
5436 		if (link->id)
5437 			link = bpf_link_inc_not_zero(link);
5438 		else
5439 			link = ERR_PTR(-EAGAIN);
5440 	} else {
5441 		link = ERR_PTR(-ENOENT);
5442 	}
5443 	spin_unlock_bh(&link_idr_lock);
5444 	return link;
5445 }
5446 
bpf_link_get_curr_or_next(u32 * id)5447 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5448 {
5449 	struct bpf_link *link;
5450 
5451 	spin_lock_bh(&link_idr_lock);
5452 again:
5453 	link = idr_get_next(&link_idr, id);
5454 	if (link) {
5455 		link = bpf_link_inc_not_zero(link);
5456 		if (IS_ERR(link)) {
5457 			(*id)++;
5458 			goto again;
5459 		}
5460 	}
5461 	spin_unlock_bh(&link_idr_lock);
5462 
5463 	return link;
5464 }
5465 
5466 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5467 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5468 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5469 {
5470 	struct bpf_link *link;
5471 	u32 id = attr->link_id;
5472 	int fd;
5473 
5474 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5475 		return -EINVAL;
5476 
5477 	if (!capable(CAP_SYS_ADMIN))
5478 		return -EPERM;
5479 
5480 	link = bpf_link_by_id(id);
5481 	if (IS_ERR(link))
5482 		return PTR_ERR(link);
5483 
5484 	fd = bpf_link_new_fd(link);
5485 	if (fd < 0)
5486 		bpf_link_put_direct(link);
5487 
5488 	return fd;
5489 }
5490 
5491 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5492 
bpf_stats_release(struct inode * inode,struct file * file)5493 static int bpf_stats_release(struct inode *inode, struct file *file)
5494 {
5495 	mutex_lock(&bpf_stats_enabled_mutex);
5496 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5497 	mutex_unlock(&bpf_stats_enabled_mutex);
5498 	return 0;
5499 }
5500 
5501 static const struct file_operations bpf_stats_fops = {
5502 	.release = bpf_stats_release,
5503 };
5504 
bpf_enable_runtime_stats(void)5505 static int bpf_enable_runtime_stats(void)
5506 {
5507 	int fd;
5508 
5509 	mutex_lock(&bpf_stats_enabled_mutex);
5510 
5511 	/* Set a very high limit to avoid overflow */
5512 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5513 		mutex_unlock(&bpf_stats_enabled_mutex);
5514 		return -EBUSY;
5515 	}
5516 
5517 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5518 	if (fd >= 0)
5519 		static_key_slow_inc(&bpf_stats_enabled_key.key);
5520 
5521 	mutex_unlock(&bpf_stats_enabled_mutex);
5522 	return fd;
5523 }
5524 
5525 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5526 
bpf_enable_stats(union bpf_attr * attr)5527 static int bpf_enable_stats(union bpf_attr *attr)
5528 {
5529 
5530 	if (CHECK_ATTR(BPF_ENABLE_STATS))
5531 		return -EINVAL;
5532 
5533 	if (!capable(CAP_SYS_ADMIN))
5534 		return -EPERM;
5535 
5536 	switch (attr->enable_stats.type) {
5537 	case BPF_STATS_RUN_TIME:
5538 		return bpf_enable_runtime_stats();
5539 	default:
5540 		break;
5541 	}
5542 	return -EINVAL;
5543 }
5544 
5545 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
5546 
bpf_iter_create(union bpf_attr * attr)5547 static int bpf_iter_create(union bpf_attr *attr)
5548 {
5549 	struct bpf_link *link;
5550 	int err;
5551 
5552 	if (CHECK_ATTR(BPF_ITER_CREATE))
5553 		return -EINVAL;
5554 
5555 	if (attr->iter_create.flags)
5556 		return -EINVAL;
5557 
5558 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
5559 	if (IS_ERR(link))
5560 		return PTR_ERR(link);
5561 
5562 	err = bpf_iter_new_fd(link);
5563 	bpf_link_put_direct(link);
5564 
5565 	return err;
5566 }
5567 
5568 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
5569 
bpf_prog_bind_map(union bpf_attr * attr)5570 static int bpf_prog_bind_map(union bpf_attr *attr)
5571 {
5572 	struct bpf_prog *prog;
5573 	struct bpf_map *map;
5574 	struct bpf_map **used_maps_old, **used_maps_new;
5575 	int i, ret = 0;
5576 
5577 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
5578 		return -EINVAL;
5579 
5580 	if (attr->prog_bind_map.flags)
5581 		return -EINVAL;
5582 
5583 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
5584 	if (IS_ERR(prog))
5585 		return PTR_ERR(prog);
5586 
5587 	map = bpf_map_get(attr->prog_bind_map.map_fd);
5588 	if (IS_ERR(map)) {
5589 		ret = PTR_ERR(map);
5590 		goto out_prog_put;
5591 	}
5592 
5593 	mutex_lock(&prog->aux->used_maps_mutex);
5594 
5595 	used_maps_old = prog->aux->used_maps;
5596 
5597 	for (i = 0; i < prog->aux->used_map_cnt; i++)
5598 		if (used_maps_old[i] == map) {
5599 			bpf_map_put(map);
5600 			goto out_unlock;
5601 		}
5602 
5603 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
5604 				      sizeof(used_maps_new[0]),
5605 				      GFP_KERNEL);
5606 	if (!used_maps_new) {
5607 		ret = -ENOMEM;
5608 		goto out_unlock;
5609 	}
5610 
5611 	/* The bpf program will not access the bpf map, but for the sake of
5612 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
5613 	 */
5614 	if (prog->sleepable)
5615 		atomic64_inc(&map->sleepable_refcnt);
5616 	memcpy(used_maps_new, used_maps_old,
5617 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
5618 	used_maps_new[prog->aux->used_map_cnt] = map;
5619 
5620 	prog->aux->used_map_cnt++;
5621 	prog->aux->used_maps = used_maps_new;
5622 
5623 	kfree(used_maps_old);
5624 
5625 out_unlock:
5626 	mutex_unlock(&prog->aux->used_maps_mutex);
5627 
5628 	if (ret)
5629 		bpf_map_put(map);
5630 out_prog_put:
5631 	bpf_prog_put(prog);
5632 	return ret;
5633 }
5634 
5635 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
5636 
token_create(union bpf_attr * attr)5637 static int token_create(union bpf_attr *attr)
5638 {
5639 	if (CHECK_ATTR(BPF_TOKEN_CREATE))
5640 		return -EINVAL;
5641 
5642 	/* no flags are supported yet */
5643 	if (attr->token_create.flags)
5644 		return -EINVAL;
5645 
5646 	return bpf_token_create(attr);
5647 }
5648 
__sys_bpf(int cmd,bpfptr_t uattr,unsigned int size)5649 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
5650 {
5651 	union bpf_attr attr;
5652 	int err;
5653 
5654 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
5655 	if (err)
5656 		return err;
5657 	size = min_t(u32, size, sizeof(attr));
5658 
5659 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
5660 	memset(&attr, 0, sizeof(attr));
5661 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
5662 		return -EFAULT;
5663 
5664 	err = security_bpf(cmd, &attr, size);
5665 	if (err < 0)
5666 		return err;
5667 
5668 	switch (cmd) {
5669 	case BPF_MAP_CREATE:
5670 		err = map_create(&attr);
5671 		break;
5672 	case BPF_MAP_LOOKUP_ELEM:
5673 		err = map_lookup_elem(&attr);
5674 		break;
5675 	case BPF_MAP_UPDATE_ELEM:
5676 		err = map_update_elem(&attr, uattr);
5677 		break;
5678 	case BPF_MAP_DELETE_ELEM:
5679 		err = map_delete_elem(&attr, uattr);
5680 		break;
5681 	case BPF_MAP_GET_NEXT_KEY:
5682 		err = map_get_next_key(&attr);
5683 		break;
5684 	case BPF_MAP_FREEZE:
5685 		err = map_freeze(&attr);
5686 		break;
5687 	case BPF_PROG_LOAD:
5688 		err = bpf_prog_load(&attr, uattr, size);
5689 		break;
5690 	case BPF_OBJ_PIN:
5691 		err = bpf_obj_pin(&attr);
5692 		break;
5693 	case BPF_OBJ_GET:
5694 		err = bpf_obj_get(&attr);
5695 		break;
5696 	case BPF_PROG_ATTACH:
5697 		err = bpf_prog_attach(&attr);
5698 		break;
5699 	case BPF_PROG_DETACH:
5700 		err = bpf_prog_detach(&attr);
5701 		break;
5702 	case BPF_PROG_QUERY:
5703 		err = bpf_prog_query(&attr, uattr.user);
5704 		break;
5705 	case BPF_PROG_TEST_RUN:
5706 		err = bpf_prog_test_run(&attr, uattr.user);
5707 		break;
5708 	case BPF_PROG_GET_NEXT_ID:
5709 		err = bpf_obj_get_next_id(&attr, uattr.user,
5710 					  &prog_idr, &prog_idr_lock);
5711 		break;
5712 	case BPF_MAP_GET_NEXT_ID:
5713 		err = bpf_obj_get_next_id(&attr, uattr.user,
5714 					  &map_idr, &map_idr_lock);
5715 		break;
5716 	case BPF_BTF_GET_NEXT_ID:
5717 		err = bpf_obj_get_next_id(&attr, uattr.user,
5718 					  &btf_idr, &btf_idr_lock);
5719 		break;
5720 	case BPF_PROG_GET_FD_BY_ID:
5721 		err = bpf_prog_get_fd_by_id(&attr);
5722 		break;
5723 	case BPF_MAP_GET_FD_BY_ID:
5724 		err = bpf_map_get_fd_by_id(&attr);
5725 		break;
5726 	case BPF_OBJ_GET_INFO_BY_FD:
5727 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
5728 		break;
5729 	case BPF_RAW_TRACEPOINT_OPEN:
5730 		err = bpf_raw_tracepoint_open(&attr);
5731 		break;
5732 	case BPF_BTF_LOAD:
5733 		err = bpf_btf_load(&attr, uattr, size);
5734 		break;
5735 	case BPF_BTF_GET_FD_BY_ID:
5736 		err = bpf_btf_get_fd_by_id(&attr);
5737 		break;
5738 	case BPF_TASK_FD_QUERY:
5739 		err = bpf_task_fd_query(&attr, uattr.user);
5740 		break;
5741 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
5742 		err = map_lookup_and_delete_elem(&attr);
5743 		break;
5744 	case BPF_MAP_LOOKUP_BATCH:
5745 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
5746 		break;
5747 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
5748 		err = bpf_map_do_batch(&attr, uattr.user,
5749 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
5750 		break;
5751 	case BPF_MAP_UPDATE_BATCH:
5752 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
5753 		break;
5754 	case BPF_MAP_DELETE_BATCH:
5755 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
5756 		break;
5757 	case BPF_LINK_CREATE:
5758 		err = link_create(&attr, uattr);
5759 		break;
5760 	case BPF_LINK_UPDATE:
5761 		err = link_update(&attr);
5762 		break;
5763 	case BPF_LINK_GET_FD_BY_ID:
5764 		err = bpf_link_get_fd_by_id(&attr);
5765 		break;
5766 	case BPF_LINK_GET_NEXT_ID:
5767 		err = bpf_obj_get_next_id(&attr, uattr.user,
5768 					  &link_idr, &link_idr_lock);
5769 		break;
5770 	case BPF_ENABLE_STATS:
5771 		err = bpf_enable_stats(&attr);
5772 		break;
5773 	case BPF_ITER_CREATE:
5774 		err = bpf_iter_create(&attr);
5775 		break;
5776 	case BPF_LINK_DETACH:
5777 		err = link_detach(&attr);
5778 		break;
5779 	case BPF_PROG_BIND_MAP:
5780 		err = bpf_prog_bind_map(&attr);
5781 		break;
5782 	case BPF_TOKEN_CREATE:
5783 		err = token_create(&attr);
5784 		break;
5785 	default:
5786 		err = -EINVAL;
5787 		break;
5788 	}
5789 
5790 	return err;
5791 }
5792 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5793 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5794 {
5795 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5796 }
5797 
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)5798 static bool syscall_prog_is_valid_access(int off, int size,
5799 					 enum bpf_access_type type,
5800 					 const struct bpf_prog *prog,
5801 					 struct bpf_insn_access_aux *info)
5802 {
5803 	if (off < 0 || off >= U16_MAX)
5804 		return false;
5805 	if (off % size != 0)
5806 		return false;
5807 	return true;
5808 }
5809 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5810 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5811 {
5812 	switch (cmd) {
5813 	case BPF_MAP_CREATE:
5814 	case BPF_MAP_DELETE_ELEM:
5815 	case BPF_MAP_UPDATE_ELEM:
5816 	case BPF_MAP_FREEZE:
5817 	case BPF_MAP_GET_FD_BY_ID:
5818 	case BPF_PROG_LOAD:
5819 	case BPF_BTF_LOAD:
5820 	case BPF_LINK_CREATE:
5821 	case BPF_RAW_TRACEPOINT_OPEN:
5822 		break;
5823 	default:
5824 		return -EINVAL;
5825 	}
5826 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5827 }
5828 
5829 
5830 /* To shut up -Wmissing-prototypes.
5831  * This function is used by the kernel light skeleton
5832  * to load bpf programs when modules are loaded or during kernel boot.
5833  * See tools/lib/bpf/skel_internal.h
5834  */
5835 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
5836 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5837 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5838 {
5839 	struct bpf_prog * __maybe_unused prog;
5840 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5841 
5842 	switch (cmd) {
5843 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5844 	case BPF_PROG_TEST_RUN:
5845 		if (attr->test.data_in || attr->test.data_out ||
5846 		    attr->test.ctx_out || attr->test.duration ||
5847 		    attr->test.repeat || attr->test.flags)
5848 			return -EINVAL;
5849 
5850 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5851 		if (IS_ERR(prog))
5852 			return PTR_ERR(prog);
5853 
5854 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
5855 		    attr->test.ctx_size_in > U16_MAX) {
5856 			bpf_prog_put(prog);
5857 			return -EINVAL;
5858 		}
5859 
5860 		run_ctx.bpf_cookie = 0;
5861 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
5862 			/* recursion detected */
5863 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
5864 			bpf_prog_put(prog);
5865 			return -EBUSY;
5866 		}
5867 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
5868 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
5869 						&run_ctx);
5870 		bpf_prog_put(prog);
5871 		return 0;
5872 #endif
5873 	default:
5874 		return ____bpf_sys_bpf(cmd, attr, size);
5875 	}
5876 }
5877 EXPORT_SYMBOL(kern_sys_bpf);
5878 
5879 static const struct bpf_func_proto bpf_sys_bpf_proto = {
5880 	.func		= bpf_sys_bpf,
5881 	.gpl_only	= false,
5882 	.ret_type	= RET_INTEGER,
5883 	.arg1_type	= ARG_ANYTHING,
5884 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
5885 	.arg3_type	= ARG_CONST_SIZE,
5886 };
5887 
5888 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5889 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5890 {
5891 	return bpf_base_func_proto(func_id, prog);
5892 }
5893 
BPF_CALL_1(bpf_sys_close,u32,fd)5894 BPF_CALL_1(bpf_sys_close, u32, fd)
5895 {
5896 	/* When bpf program calls this helper there should not be
5897 	 * an fdget() without matching completed fdput().
5898 	 * This helper is allowed in the following callchain only:
5899 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
5900 	 */
5901 	return close_fd(fd);
5902 }
5903 
5904 static const struct bpf_func_proto bpf_sys_close_proto = {
5905 	.func		= bpf_sys_close,
5906 	.gpl_only	= false,
5907 	.ret_type	= RET_INTEGER,
5908 	.arg1_type	= ARG_ANYTHING,
5909 };
5910 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)5911 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
5912 {
5913 	if (flags)
5914 		return -EINVAL;
5915 
5916 	if (name_sz <= 1 || name[name_sz - 1])
5917 		return -EINVAL;
5918 
5919 	if (!bpf_dump_raw_ok(current_cred()))
5920 		return -EPERM;
5921 
5922 	*res = kallsyms_lookup_name(name);
5923 	return *res ? 0 : -ENOENT;
5924 }
5925 
5926 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
5927 	.func		= bpf_kallsyms_lookup_name,
5928 	.gpl_only	= false,
5929 	.ret_type	= RET_INTEGER,
5930 	.arg1_type	= ARG_PTR_TO_MEM,
5931 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
5932 	.arg3_type	= ARG_ANYTHING,
5933 	.arg4_type	= ARG_PTR_TO_LONG,
5934 };
5935 
5936 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5937 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5938 {
5939 	switch (func_id) {
5940 	case BPF_FUNC_sys_bpf:
5941 		return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
5942 		       ? NULL : &bpf_sys_bpf_proto;
5943 	case BPF_FUNC_btf_find_by_name_kind:
5944 		return &bpf_btf_find_by_name_kind_proto;
5945 	case BPF_FUNC_sys_close:
5946 		return &bpf_sys_close_proto;
5947 	case BPF_FUNC_kallsyms_lookup_name:
5948 		return &bpf_kallsyms_lookup_name_proto;
5949 	default:
5950 		return tracing_prog_func_proto(func_id, prog);
5951 	}
5952 }
5953 
5954 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
5955 	.get_func_proto  = syscall_prog_func_proto,
5956 	.is_valid_access = syscall_prog_is_valid_access,
5957 };
5958 
5959 const struct bpf_prog_ops bpf_syscall_prog_ops = {
5960 	.test_run = bpf_prog_test_run_syscall,
5961 };
5962 
5963 #ifdef CONFIG_SYSCTL
bpf_stats_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5964 static int bpf_stats_handler(struct ctl_table *table, int write,
5965 			     void *buffer, size_t *lenp, loff_t *ppos)
5966 {
5967 	struct static_key *key = (struct static_key *)table->data;
5968 	static int saved_val;
5969 	int val, ret;
5970 	struct ctl_table tmp = {
5971 		.data   = &val,
5972 		.maxlen = sizeof(val),
5973 		.mode   = table->mode,
5974 		.extra1 = SYSCTL_ZERO,
5975 		.extra2 = SYSCTL_ONE,
5976 	};
5977 
5978 	if (write && !capable(CAP_SYS_ADMIN))
5979 		return -EPERM;
5980 
5981 	mutex_lock(&bpf_stats_enabled_mutex);
5982 	val = saved_val;
5983 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
5984 	if (write && !ret && val != saved_val) {
5985 		if (val)
5986 			static_key_slow_inc(key);
5987 		else
5988 			static_key_slow_dec(key);
5989 		saved_val = val;
5990 	}
5991 	mutex_unlock(&bpf_stats_enabled_mutex);
5992 	return ret;
5993 }
5994 
unpriv_ebpf_notify(int new_state)5995 void __weak unpriv_ebpf_notify(int new_state)
5996 {
5997 }
5998 
bpf_unpriv_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5999 static int bpf_unpriv_handler(struct ctl_table *table, int write,
6000 			      void *buffer, size_t *lenp, loff_t *ppos)
6001 {
6002 	int ret, unpriv_enable = *(int *)table->data;
6003 	bool locked_state = unpriv_enable == 1;
6004 	struct ctl_table tmp = *table;
6005 
6006 	if (write && !capable(CAP_SYS_ADMIN))
6007 		return -EPERM;
6008 
6009 	tmp.data = &unpriv_enable;
6010 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6011 	if (write && !ret) {
6012 		if (locked_state && unpriv_enable != 1)
6013 			return -EPERM;
6014 		*(int *)table->data = unpriv_enable;
6015 	}
6016 
6017 	if (write)
6018 		unpriv_ebpf_notify(unpriv_enable);
6019 
6020 	return ret;
6021 }
6022 
6023 static struct ctl_table bpf_syscall_table[] = {
6024 	{
6025 		.procname	= "unprivileged_bpf_disabled",
6026 		.data		= &sysctl_unprivileged_bpf_disabled,
6027 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
6028 		.mode		= 0644,
6029 		.proc_handler	= bpf_unpriv_handler,
6030 		.extra1		= SYSCTL_ZERO,
6031 		.extra2		= SYSCTL_TWO,
6032 	},
6033 	{
6034 		.procname	= "bpf_stats_enabled",
6035 		.data		= &bpf_stats_enabled_key.key,
6036 		.mode		= 0644,
6037 		.proc_handler	= bpf_stats_handler,
6038 	},
6039 };
6040 
bpf_syscall_sysctl_init(void)6041 static int __init bpf_syscall_sysctl_init(void)
6042 {
6043 	register_sysctl_init("kernel", bpf_syscall_table);
6044 	return 0;
6045 }
6046 late_initcall(bpf_syscall_sysctl_init);
6047 #endif /* CONFIG_SYSCTL */
6048