xref: /linux/kernel/bpf/syscall.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
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
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
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
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 
bpf_link_poll(struct file * file,struct poll_table_struct * pts)3154 static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
3155 {
3156 	struct bpf_link *link = file->private_data;
3157 
3158 	return link->ops->poll(file, pts);
3159 }
3160 
3161 static const struct file_operations bpf_link_fops = {
3162 #ifdef CONFIG_PROC_FS
3163 	.show_fdinfo	= bpf_link_show_fdinfo,
3164 #endif
3165 	.release	= bpf_link_release,
3166 	.read		= bpf_dummy_read,
3167 	.write		= bpf_dummy_write,
3168 };
3169 
3170 static const struct file_operations bpf_link_fops_poll = {
3171 #ifdef CONFIG_PROC_FS
3172 	.show_fdinfo	= bpf_link_show_fdinfo,
3173 #endif
3174 	.release	= bpf_link_release,
3175 	.read		= bpf_dummy_read,
3176 	.write		= bpf_dummy_write,
3177 	.poll		= bpf_link_poll,
3178 };
3179 
bpf_link_alloc_id(struct bpf_link * link)3180 static int bpf_link_alloc_id(struct bpf_link *link)
3181 {
3182 	int id;
3183 
3184 	idr_preload(GFP_KERNEL);
3185 	spin_lock_bh(&link_idr_lock);
3186 	id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
3187 	spin_unlock_bh(&link_idr_lock);
3188 	idr_preload_end();
3189 
3190 	return id;
3191 }
3192 
3193 /* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
3194  * reserving unused FD and allocating ID from link_idr. This is to be paired
3195  * with bpf_link_settle() to install FD and ID and expose bpf_link to
3196  * user-space, if bpf_link is successfully attached. If not, bpf_link and
3197  * pre-allocated resources are to be freed with bpf_cleanup() call. All the
3198  * transient state is passed around in struct bpf_link_primer.
3199  * This is preferred way to create and initialize bpf_link, especially when
3200  * there are complicated and expensive operations in between creating bpf_link
3201  * itself and attaching it to BPF hook. By using bpf_link_prime() and
3202  * bpf_link_settle() kernel code using bpf_link doesn't have to perform
3203  * expensive (and potentially failing) roll back operations in a rare case
3204  * that file, FD, or ID can't be allocated.
3205  */
bpf_link_prime(struct bpf_link * link,struct bpf_link_primer * primer)3206 int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
3207 {
3208 	struct file *file;
3209 	int fd, id;
3210 
3211 	fd = get_unused_fd_flags(O_CLOEXEC);
3212 	if (fd < 0)
3213 		return fd;
3214 
3215 
3216 	id = bpf_link_alloc_id(link);
3217 	if (id < 0) {
3218 		put_unused_fd(fd);
3219 		return id;
3220 	}
3221 
3222 	file = anon_inode_getfile("bpf_link",
3223 				  link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3224 				  link, O_CLOEXEC);
3225 	if (IS_ERR(file)) {
3226 		bpf_link_free_id(id);
3227 		put_unused_fd(fd);
3228 		return PTR_ERR(file);
3229 	}
3230 
3231 	primer->link = link;
3232 	primer->file = file;
3233 	primer->fd = fd;
3234 	primer->id = id;
3235 	return 0;
3236 }
3237 
bpf_link_settle(struct bpf_link_primer * primer)3238 int bpf_link_settle(struct bpf_link_primer *primer)
3239 {
3240 	/* make bpf_link fetchable by ID */
3241 	spin_lock_bh(&link_idr_lock);
3242 	primer->link->id = primer->id;
3243 	spin_unlock_bh(&link_idr_lock);
3244 	/* make bpf_link fetchable by FD */
3245 	fd_install(primer->fd, primer->file);
3246 	/* pass through installed FD */
3247 	return primer->fd;
3248 }
3249 
bpf_link_new_fd(struct bpf_link * link)3250 int bpf_link_new_fd(struct bpf_link *link)
3251 {
3252 	return anon_inode_getfd("bpf-link",
3253 				link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
3254 				link, O_CLOEXEC);
3255 }
3256 
bpf_link_get_from_fd(u32 ufd)3257 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
3258 {
3259 	struct fd f = fdget(ufd);
3260 	struct bpf_link *link;
3261 
3262 	if (!f.file)
3263 		return ERR_PTR(-EBADF);
3264 	if (f.file->f_op != &bpf_link_fops && f.file->f_op != &bpf_link_fops_poll) {
3265 		fdput(f);
3266 		return ERR_PTR(-EINVAL);
3267 	}
3268 
3269 	link = f.file->private_data;
3270 	bpf_link_inc(link);
3271 	fdput(f);
3272 
3273 	return link;
3274 }
3275 EXPORT_SYMBOL(bpf_link_get_from_fd);
3276 
bpf_tracing_link_release(struct bpf_link * link)3277 static void bpf_tracing_link_release(struct bpf_link *link)
3278 {
3279 	struct bpf_tracing_link *tr_link =
3280 		container_of(link, struct bpf_tracing_link, link.link);
3281 
3282 	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
3283 						tr_link->trampoline));
3284 
3285 	bpf_trampoline_put(tr_link->trampoline);
3286 
3287 	/* tgt_prog is NULL if target is a kernel function */
3288 	if (tr_link->tgt_prog)
3289 		bpf_prog_put(tr_link->tgt_prog);
3290 }
3291 
bpf_tracing_link_dealloc(struct bpf_link * link)3292 static void bpf_tracing_link_dealloc(struct bpf_link *link)
3293 {
3294 	struct bpf_tracing_link *tr_link =
3295 		container_of(link, struct bpf_tracing_link, link.link);
3296 
3297 	kfree(tr_link);
3298 }
3299 
bpf_tracing_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3300 static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
3301 					 struct seq_file *seq)
3302 {
3303 	struct bpf_tracing_link *tr_link =
3304 		container_of(link, struct bpf_tracing_link, link.link);
3305 	u32 target_btf_id, target_obj_id;
3306 
3307 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3308 				  &target_obj_id, &target_btf_id);
3309 	seq_printf(seq,
3310 		   "attach_type:\t%d\n"
3311 		   "target_obj_id:\t%u\n"
3312 		   "target_btf_id:\t%u\n",
3313 		   tr_link->attach_type,
3314 		   target_obj_id,
3315 		   target_btf_id);
3316 }
3317 
bpf_tracing_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3318 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
3319 					   struct bpf_link_info *info)
3320 {
3321 	struct bpf_tracing_link *tr_link =
3322 		container_of(link, struct bpf_tracing_link, link.link);
3323 
3324 	info->tracing.attach_type = tr_link->attach_type;
3325 	bpf_trampoline_unpack_key(tr_link->trampoline->key,
3326 				  &info->tracing.target_obj_id,
3327 				  &info->tracing.target_btf_id);
3328 
3329 	return 0;
3330 }
3331 
3332 static const struct bpf_link_ops bpf_tracing_link_lops = {
3333 	.release = bpf_tracing_link_release,
3334 	.dealloc = bpf_tracing_link_dealloc,
3335 	.show_fdinfo = bpf_tracing_link_show_fdinfo,
3336 	.fill_link_info = bpf_tracing_link_fill_link_info,
3337 };
3338 
bpf_tracing_prog_attach(struct bpf_prog * prog,int tgt_prog_fd,u32 btf_id,u64 bpf_cookie)3339 static int bpf_tracing_prog_attach(struct bpf_prog *prog,
3340 				   int tgt_prog_fd,
3341 				   u32 btf_id,
3342 				   u64 bpf_cookie)
3343 {
3344 	struct bpf_link_primer link_primer;
3345 	struct bpf_prog *tgt_prog = NULL;
3346 	struct bpf_trampoline *tr = NULL;
3347 	struct bpf_tracing_link *link;
3348 	u64 key = 0;
3349 	int err;
3350 
3351 	switch (prog->type) {
3352 	case BPF_PROG_TYPE_TRACING:
3353 		if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
3354 		    prog->expected_attach_type != BPF_TRACE_FEXIT &&
3355 		    prog->expected_attach_type != BPF_MODIFY_RETURN) {
3356 			err = -EINVAL;
3357 			goto out_put_prog;
3358 		}
3359 		break;
3360 	case BPF_PROG_TYPE_EXT:
3361 		if (prog->expected_attach_type != 0) {
3362 			err = -EINVAL;
3363 			goto out_put_prog;
3364 		}
3365 		break;
3366 	case BPF_PROG_TYPE_LSM:
3367 		if (prog->expected_attach_type != BPF_LSM_MAC) {
3368 			err = -EINVAL;
3369 			goto out_put_prog;
3370 		}
3371 		break;
3372 	default:
3373 		err = -EINVAL;
3374 		goto out_put_prog;
3375 	}
3376 
3377 	if (!!tgt_prog_fd != !!btf_id) {
3378 		err = -EINVAL;
3379 		goto out_put_prog;
3380 	}
3381 
3382 	if (tgt_prog_fd) {
3383 		/*
3384 		 * For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
3385 		 * part would be changed to implement the same for
3386 		 * BPF_PROG_TYPE_TRACING, do not forget to update the way how
3387 		 * attach_tracing_prog flag is set.
3388 		 */
3389 		if (prog->type != BPF_PROG_TYPE_EXT) {
3390 			err = -EINVAL;
3391 			goto out_put_prog;
3392 		}
3393 
3394 		tgt_prog = bpf_prog_get(tgt_prog_fd);
3395 		if (IS_ERR(tgt_prog)) {
3396 			err = PTR_ERR(tgt_prog);
3397 			tgt_prog = NULL;
3398 			goto out_put_prog;
3399 		}
3400 
3401 		key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
3402 	}
3403 
3404 	link = kzalloc(sizeof(*link), GFP_USER);
3405 	if (!link) {
3406 		err = -ENOMEM;
3407 		goto out_put_prog;
3408 	}
3409 	bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
3410 		      &bpf_tracing_link_lops, prog);
3411 	link->attach_type = prog->expected_attach_type;
3412 	link->link.cookie = bpf_cookie;
3413 
3414 	mutex_lock(&prog->aux->dst_mutex);
3415 
3416 	/* There are a few possible cases here:
3417 	 *
3418 	 * - if prog->aux->dst_trampoline is set, the program was just loaded
3419 	 *   and not yet attached to anything, so we can use the values stored
3420 	 *   in prog->aux
3421 	 *
3422 	 * - if prog->aux->dst_trampoline is NULL, the program has already been
3423          *   attached to a target and its initial target was cleared (below)
3424 	 *
3425 	 * - if tgt_prog != NULL, the caller specified tgt_prog_fd +
3426 	 *   target_btf_id using the link_create API.
3427 	 *
3428 	 * - if tgt_prog == NULL when this function was called using the old
3429 	 *   raw_tracepoint_open API, and we need a target from prog->aux
3430 	 *
3431 	 * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
3432 	 *   was detached and is going for re-attachment.
3433 	 *
3434 	 * - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
3435 	 *   are NULL, then program was already attached and user did not provide
3436 	 *   tgt_prog_fd so we have no way to find out or create trampoline
3437 	 */
3438 	if (!prog->aux->dst_trampoline && !tgt_prog) {
3439 		/*
3440 		 * Allow re-attach for TRACING and LSM programs. If it's
3441 		 * currently linked, bpf_trampoline_link_prog will fail.
3442 		 * EXT programs need to specify tgt_prog_fd, so they
3443 		 * re-attach in separate code path.
3444 		 */
3445 		if (prog->type != BPF_PROG_TYPE_TRACING &&
3446 		    prog->type != BPF_PROG_TYPE_LSM) {
3447 			err = -EINVAL;
3448 			goto out_unlock;
3449 		}
3450 		/* We can allow re-attach only if we have valid attach_btf. */
3451 		if (!prog->aux->attach_btf) {
3452 			err = -EINVAL;
3453 			goto out_unlock;
3454 		}
3455 		btf_id = prog->aux->attach_btf_id;
3456 		key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
3457 	}
3458 
3459 	if (!prog->aux->dst_trampoline ||
3460 	    (key && key != prog->aux->dst_trampoline->key)) {
3461 		/* If there is no saved target, or the specified target is
3462 		 * different from the destination specified at load time, we
3463 		 * need a new trampoline and a check for compatibility
3464 		 */
3465 		struct bpf_attach_target_info tgt_info = {};
3466 
3467 		err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
3468 					      &tgt_info);
3469 		if (err)
3470 			goto out_unlock;
3471 
3472 		if (tgt_info.tgt_mod) {
3473 			module_put(prog->aux->mod);
3474 			prog->aux->mod = tgt_info.tgt_mod;
3475 		}
3476 
3477 		tr = bpf_trampoline_get(key, &tgt_info);
3478 		if (!tr) {
3479 			err = -ENOMEM;
3480 			goto out_unlock;
3481 		}
3482 	} else {
3483 		/* The caller didn't specify a target, or the target was the
3484 		 * same as the destination supplied during program load. This
3485 		 * means we can reuse the trampoline and reference from program
3486 		 * load time, and there is no need to allocate a new one. This
3487 		 * can only happen once for any program, as the saved values in
3488 		 * prog->aux are cleared below.
3489 		 */
3490 		tr = prog->aux->dst_trampoline;
3491 		tgt_prog = prog->aux->dst_prog;
3492 	}
3493 
3494 	err = bpf_link_prime(&link->link.link, &link_primer);
3495 	if (err)
3496 		goto out_unlock;
3497 
3498 	err = bpf_trampoline_link_prog(&link->link, tr);
3499 	if (err) {
3500 		bpf_link_cleanup(&link_primer);
3501 		link = NULL;
3502 		goto out_unlock;
3503 	}
3504 
3505 	link->tgt_prog = tgt_prog;
3506 	link->trampoline = tr;
3507 
3508 	/* Always clear the trampoline and target prog from prog->aux to make
3509 	 * sure the original attach destination is not kept alive after a
3510 	 * program is (re-)attached to another target.
3511 	 */
3512 	if (prog->aux->dst_prog &&
3513 	    (tgt_prog_fd || tr != prog->aux->dst_trampoline))
3514 		/* got extra prog ref from syscall, or attaching to different prog */
3515 		bpf_prog_put(prog->aux->dst_prog);
3516 	if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
3517 		/* we allocated a new trampoline, so free the old one */
3518 		bpf_trampoline_put(prog->aux->dst_trampoline);
3519 
3520 	prog->aux->dst_prog = NULL;
3521 	prog->aux->dst_trampoline = NULL;
3522 	mutex_unlock(&prog->aux->dst_mutex);
3523 
3524 	return bpf_link_settle(&link_primer);
3525 out_unlock:
3526 	if (tr && tr != prog->aux->dst_trampoline)
3527 		bpf_trampoline_put(tr);
3528 	mutex_unlock(&prog->aux->dst_mutex);
3529 	kfree(link);
3530 out_put_prog:
3531 	if (tgt_prog_fd && tgt_prog)
3532 		bpf_prog_put(tgt_prog);
3533 	return err;
3534 }
3535 
bpf_raw_tp_link_release(struct bpf_link * link)3536 static void bpf_raw_tp_link_release(struct bpf_link *link)
3537 {
3538 	struct bpf_raw_tp_link *raw_tp =
3539 		container_of(link, struct bpf_raw_tp_link, link);
3540 
3541 	bpf_probe_unregister(raw_tp->btp, raw_tp);
3542 	bpf_put_raw_tracepoint(raw_tp->btp);
3543 }
3544 
bpf_raw_tp_link_dealloc(struct bpf_link * link)3545 static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
3546 {
3547 	struct bpf_raw_tp_link *raw_tp =
3548 		container_of(link, struct bpf_raw_tp_link, link);
3549 
3550 	kfree(raw_tp);
3551 }
3552 
bpf_raw_tp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)3553 static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
3554 					struct seq_file *seq)
3555 {
3556 	struct bpf_raw_tp_link *raw_tp_link =
3557 		container_of(link, struct bpf_raw_tp_link, link);
3558 
3559 	seq_printf(seq,
3560 		   "tp_name:\t%s\n",
3561 		   raw_tp_link->btp->tp->name);
3562 }
3563 
bpf_copy_to_user(char __user * ubuf,const char * buf,u32 ulen,u32 len)3564 static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
3565 			    u32 len)
3566 {
3567 	if (ulen >= len + 1) {
3568 		if (copy_to_user(ubuf, buf, len + 1))
3569 			return -EFAULT;
3570 	} else {
3571 		char zero = '\0';
3572 
3573 		if (copy_to_user(ubuf, buf, ulen - 1))
3574 			return -EFAULT;
3575 		if (put_user(zero, ubuf + ulen - 1))
3576 			return -EFAULT;
3577 		return -ENOSPC;
3578 	}
3579 
3580 	return 0;
3581 }
3582 
bpf_raw_tp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3583 static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
3584 					  struct bpf_link_info *info)
3585 {
3586 	struct bpf_raw_tp_link *raw_tp_link =
3587 		container_of(link, struct bpf_raw_tp_link, link);
3588 	char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
3589 	const char *tp_name = raw_tp_link->btp->tp->name;
3590 	u32 ulen = info->raw_tracepoint.tp_name_len;
3591 	size_t tp_len = strlen(tp_name);
3592 
3593 	if (!ulen ^ !ubuf)
3594 		return -EINVAL;
3595 
3596 	info->raw_tracepoint.tp_name_len = tp_len + 1;
3597 
3598 	if (!ubuf)
3599 		return 0;
3600 
3601 	return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
3602 }
3603 
3604 static const struct bpf_link_ops bpf_raw_tp_link_lops = {
3605 	.release = bpf_raw_tp_link_release,
3606 	.dealloc_deferred = bpf_raw_tp_link_dealloc,
3607 	.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
3608 	.fill_link_info = bpf_raw_tp_link_fill_link_info,
3609 };
3610 
3611 #ifdef CONFIG_PERF_EVENTS
3612 struct bpf_perf_link {
3613 	struct bpf_link link;
3614 	struct file *perf_file;
3615 };
3616 
bpf_perf_link_release(struct bpf_link * link)3617 static void bpf_perf_link_release(struct bpf_link *link)
3618 {
3619 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3620 	struct perf_event *event = perf_link->perf_file->private_data;
3621 
3622 	perf_event_free_bpf_prog(event);
3623 	fput(perf_link->perf_file);
3624 }
3625 
bpf_perf_link_dealloc(struct bpf_link * link)3626 static void bpf_perf_link_dealloc(struct bpf_link *link)
3627 {
3628 	struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
3629 
3630 	kfree(perf_link);
3631 }
3632 
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)3633 static int bpf_perf_link_fill_common(const struct perf_event *event,
3634 				     char __user *uname, u32 ulen,
3635 				     u64 *probe_offset, u64 *probe_addr,
3636 				     u32 *fd_type, unsigned long *missed)
3637 {
3638 	const char *buf;
3639 	u32 prog_id;
3640 	size_t len;
3641 	int err;
3642 
3643 	if (!ulen ^ !uname)
3644 		return -EINVAL;
3645 
3646 	err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
3647 				      probe_offset, probe_addr, missed);
3648 	if (err)
3649 		return err;
3650 	if (!uname)
3651 		return 0;
3652 	if (buf) {
3653 		len = strlen(buf);
3654 		err = bpf_copy_to_user(uname, buf, ulen, len);
3655 		if (err)
3656 			return err;
3657 	} else {
3658 		char zero = '\0';
3659 
3660 		if (put_user(zero, uname))
3661 			return -EFAULT;
3662 	}
3663 	return 0;
3664 }
3665 
3666 #ifdef CONFIG_KPROBE_EVENTS
bpf_perf_link_fill_kprobe(const struct perf_event * event,struct bpf_link_info * info)3667 static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
3668 				     struct bpf_link_info *info)
3669 {
3670 	unsigned long missed;
3671 	char __user *uname;
3672 	u64 addr, offset;
3673 	u32 ulen, type;
3674 	int err;
3675 
3676 	uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
3677 	ulen = info->perf_event.kprobe.name_len;
3678 	err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr,
3679 					&type, &missed);
3680 	if (err)
3681 		return err;
3682 	if (type == BPF_FD_TYPE_KRETPROBE)
3683 		info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
3684 	else
3685 		info->perf_event.type = BPF_PERF_EVENT_KPROBE;
3686 
3687 	info->perf_event.kprobe.offset = offset;
3688 	info->perf_event.kprobe.missed = missed;
3689 	if (!kallsyms_show_value(current_cred()))
3690 		addr = 0;
3691 	info->perf_event.kprobe.addr = addr;
3692 	info->perf_event.kprobe.cookie = event->bpf_cookie;
3693 	return 0;
3694 }
3695 #endif
3696 
3697 #ifdef CONFIG_UPROBE_EVENTS
bpf_perf_link_fill_uprobe(const struct perf_event * event,struct bpf_link_info * info)3698 static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
3699 				     struct bpf_link_info *info)
3700 {
3701 	char __user *uname;
3702 	u64 addr, offset;
3703 	u32 ulen, type;
3704 	int err;
3705 
3706 	uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
3707 	ulen = info->perf_event.uprobe.name_len;
3708 	err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr,
3709 					&type, NULL);
3710 	if (err)
3711 		return err;
3712 
3713 	if (type == BPF_FD_TYPE_URETPROBE)
3714 		info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
3715 	else
3716 		info->perf_event.type = BPF_PERF_EVENT_UPROBE;
3717 	info->perf_event.uprobe.offset = offset;
3718 	info->perf_event.uprobe.cookie = event->bpf_cookie;
3719 	return 0;
3720 }
3721 #endif
3722 
bpf_perf_link_fill_probe(const struct perf_event * event,struct bpf_link_info * info)3723 static int bpf_perf_link_fill_probe(const struct perf_event *event,
3724 				    struct bpf_link_info *info)
3725 {
3726 #ifdef CONFIG_KPROBE_EVENTS
3727 	if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
3728 		return bpf_perf_link_fill_kprobe(event, info);
3729 #endif
3730 #ifdef CONFIG_UPROBE_EVENTS
3731 	if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
3732 		return bpf_perf_link_fill_uprobe(event, info);
3733 #endif
3734 	return -EOPNOTSUPP;
3735 }
3736 
bpf_perf_link_fill_tracepoint(const struct perf_event * event,struct bpf_link_info * info)3737 static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
3738 					 struct bpf_link_info *info)
3739 {
3740 	char __user *uname;
3741 	u32 ulen;
3742 
3743 	uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
3744 	ulen = info->perf_event.tracepoint.name_len;
3745 	info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
3746 	info->perf_event.tracepoint.cookie = event->bpf_cookie;
3747 	return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL, NULL);
3748 }
3749 
bpf_perf_link_fill_perf_event(const struct perf_event * event,struct bpf_link_info * info)3750 static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
3751 					 struct bpf_link_info *info)
3752 {
3753 	info->perf_event.event.type = event->attr.type;
3754 	info->perf_event.event.config = event->attr.config;
3755 	info->perf_event.event.cookie = event->bpf_cookie;
3756 	info->perf_event.type = BPF_PERF_EVENT_EVENT;
3757 	return 0;
3758 }
3759 
bpf_perf_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)3760 static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
3761 					struct bpf_link_info *info)
3762 {
3763 	struct bpf_perf_link *perf_link;
3764 	const struct perf_event *event;
3765 
3766 	perf_link = container_of(link, struct bpf_perf_link, link);
3767 	event = perf_get_event(perf_link->perf_file);
3768 	if (IS_ERR(event))
3769 		return PTR_ERR(event);
3770 
3771 	switch (event->prog->type) {
3772 	case BPF_PROG_TYPE_PERF_EVENT:
3773 		return bpf_perf_link_fill_perf_event(event, info);
3774 	case BPF_PROG_TYPE_TRACEPOINT:
3775 		return bpf_perf_link_fill_tracepoint(event, info);
3776 	case BPF_PROG_TYPE_KPROBE:
3777 		return bpf_perf_link_fill_probe(event, info);
3778 	default:
3779 		return -EOPNOTSUPP;
3780 	}
3781 }
3782 
3783 static const struct bpf_link_ops bpf_perf_link_lops = {
3784 	.release = bpf_perf_link_release,
3785 	.dealloc = bpf_perf_link_dealloc,
3786 	.fill_link_info = bpf_perf_link_fill_link_info,
3787 };
3788 
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3789 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3790 {
3791 	struct bpf_link_primer link_primer;
3792 	struct bpf_perf_link *link;
3793 	struct perf_event *event;
3794 	struct file *perf_file;
3795 	int err;
3796 
3797 	if (attr->link_create.flags)
3798 		return -EINVAL;
3799 
3800 	perf_file = perf_event_get(attr->link_create.target_fd);
3801 	if (IS_ERR(perf_file))
3802 		return PTR_ERR(perf_file);
3803 
3804 	link = kzalloc(sizeof(*link), GFP_USER);
3805 	if (!link) {
3806 		err = -ENOMEM;
3807 		goto out_put_file;
3808 	}
3809 	bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
3810 	link->perf_file = perf_file;
3811 
3812 	err = bpf_link_prime(&link->link, &link_primer);
3813 	if (err) {
3814 		kfree(link);
3815 		goto out_put_file;
3816 	}
3817 
3818 	event = perf_file->private_data;
3819 	err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
3820 	if (err) {
3821 		bpf_link_cleanup(&link_primer);
3822 		goto out_put_file;
3823 	}
3824 	/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
3825 	bpf_prog_inc(prog);
3826 
3827 	return bpf_link_settle(&link_primer);
3828 
3829 out_put_file:
3830 	fput(perf_file);
3831 	return err;
3832 }
3833 #else
bpf_perf_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)3834 static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
3835 {
3836 	return -EOPNOTSUPP;
3837 }
3838 #endif /* CONFIG_PERF_EVENTS */
3839 
bpf_raw_tp_link_attach(struct bpf_prog * prog,const char __user * user_tp_name,u64 cookie)3840 static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
3841 				  const char __user *user_tp_name, u64 cookie)
3842 {
3843 	struct bpf_link_primer link_primer;
3844 	struct bpf_raw_tp_link *link;
3845 	struct bpf_raw_event_map *btp;
3846 	const char *tp_name;
3847 	char buf[128];
3848 	int err;
3849 
3850 	switch (prog->type) {
3851 	case BPF_PROG_TYPE_TRACING:
3852 	case BPF_PROG_TYPE_EXT:
3853 	case BPF_PROG_TYPE_LSM:
3854 		if (user_tp_name)
3855 			/* The attach point for this category of programs
3856 			 * should be specified via btf_id during program load.
3857 			 */
3858 			return -EINVAL;
3859 		if (prog->type == BPF_PROG_TYPE_TRACING &&
3860 		    prog->expected_attach_type == BPF_TRACE_RAW_TP) {
3861 			tp_name = prog->aux->attach_func_name;
3862 			break;
3863 		}
3864 		return bpf_tracing_prog_attach(prog, 0, 0, 0);
3865 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
3866 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
3867 		if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
3868 			return -EFAULT;
3869 		buf[sizeof(buf) - 1] = 0;
3870 		tp_name = buf;
3871 		break;
3872 	default:
3873 		return -EINVAL;
3874 	}
3875 
3876 	btp = bpf_get_raw_tracepoint(tp_name);
3877 	if (!btp)
3878 		return -ENOENT;
3879 
3880 	link = kzalloc(sizeof(*link), GFP_USER);
3881 	if (!link) {
3882 		err = -ENOMEM;
3883 		goto out_put_btp;
3884 	}
3885 	bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
3886 		      &bpf_raw_tp_link_lops, prog);
3887 	link->btp = btp;
3888 	link->cookie = cookie;
3889 
3890 	err = bpf_link_prime(&link->link, &link_primer);
3891 	if (err) {
3892 		kfree(link);
3893 		goto out_put_btp;
3894 	}
3895 
3896 	err = bpf_probe_register(link->btp, link);
3897 	if (err) {
3898 		bpf_link_cleanup(&link_primer);
3899 		goto out_put_btp;
3900 	}
3901 
3902 	return bpf_link_settle(&link_primer);
3903 
3904 out_put_btp:
3905 	bpf_put_raw_tracepoint(btp);
3906 	return err;
3907 }
3908 
3909 #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
3910 
bpf_raw_tracepoint_open(const union bpf_attr * attr)3911 static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
3912 {
3913 	struct bpf_prog *prog;
3914 	void __user *tp_name;
3915 	__u64 cookie;
3916 	int fd;
3917 
3918 	if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
3919 		return -EINVAL;
3920 
3921 	prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
3922 	if (IS_ERR(prog))
3923 		return PTR_ERR(prog);
3924 
3925 	tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
3926 	cookie = attr->raw_tracepoint.cookie;
3927 	fd = bpf_raw_tp_link_attach(prog, tp_name, cookie);
3928 	if (fd < 0)
3929 		bpf_prog_put(prog);
3930 	return fd;
3931 }
3932 
3933 static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)3934 attach_type_to_prog_type(enum bpf_attach_type attach_type)
3935 {
3936 	switch (attach_type) {
3937 	case BPF_CGROUP_INET_INGRESS:
3938 	case BPF_CGROUP_INET_EGRESS:
3939 		return BPF_PROG_TYPE_CGROUP_SKB;
3940 	case BPF_CGROUP_INET_SOCK_CREATE:
3941 	case BPF_CGROUP_INET_SOCK_RELEASE:
3942 	case BPF_CGROUP_INET4_POST_BIND:
3943 	case BPF_CGROUP_INET6_POST_BIND:
3944 		return BPF_PROG_TYPE_CGROUP_SOCK;
3945 	case BPF_CGROUP_INET4_BIND:
3946 	case BPF_CGROUP_INET6_BIND:
3947 	case BPF_CGROUP_INET4_CONNECT:
3948 	case BPF_CGROUP_INET6_CONNECT:
3949 	case BPF_CGROUP_UNIX_CONNECT:
3950 	case BPF_CGROUP_INET4_GETPEERNAME:
3951 	case BPF_CGROUP_INET6_GETPEERNAME:
3952 	case BPF_CGROUP_UNIX_GETPEERNAME:
3953 	case BPF_CGROUP_INET4_GETSOCKNAME:
3954 	case BPF_CGROUP_INET6_GETSOCKNAME:
3955 	case BPF_CGROUP_UNIX_GETSOCKNAME:
3956 	case BPF_CGROUP_UDP4_SENDMSG:
3957 	case BPF_CGROUP_UDP6_SENDMSG:
3958 	case BPF_CGROUP_UNIX_SENDMSG:
3959 	case BPF_CGROUP_UDP4_RECVMSG:
3960 	case BPF_CGROUP_UDP6_RECVMSG:
3961 	case BPF_CGROUP_UNIX_RECVMSG:
3962 		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
3963 	case BPF_CGROUP_SOCK_OPS:
3964 		return BPF_PROG_TYPE_SOCK_OPS;
3965 	case BPF_CGROUP_DEVICE:
3966 		return BPF_PROG_TYPE_CGROUP_DEVICE;
3967 	case BPF_SK_MSG_VERDICT:
3968 		return BPF_PROG_TYPE_SK_MSG;
3969 	case BPF_SK_SKB_STREAM_PARSER:
3970 	case BPF_SK_SKB_STREAM_VERDICT:
3971 	case BPF_SK_SKB_VERDICT:
3972 		return BPF_PROG_TYPE_SK_SKB;
3973 	case BPF_LIRC_MODE2:
3974 		return BPF_PROG_TYPE_LIRC_MODE2;
3975 	case BPF_FLOW_DISSECTOR:
3976 		return BPF_PROG_TYPE_FLOW_DISSECTOR;
3977 	case BPF_CGROUP_SYSCTL:
3978 		return BPF_PROG_TYPE_CGROUP_SYSCTL;
3979 	case BPF_CGROUP_GETSOCKOPT:
3980 	case BPF_CGROUP_SETSOCKOPT:
3981 		return BPF_PROG_TYPE_CGROUP_SOCKOPT;
3982 	case BPF_TRACE_ITER:
3983 	case BPF_TRACE_RAW_TP:
3984 	case BPF_TRACE_FENTRY:
3985 	case BPF_TRACE_FEXIT:
3986 	case BPF_MODIFY_RETURN:
3987 		return BPF_PROG_TYPE_TRACING;
3988 	case BPF_LSM_MAC:
3989 		return BPF_PROG_TYPE_LSM;
3990 	case BPF_SK_LOOKUP:
3991 		return BPF_PROG_TYPE_SK_LOOKUP;
3992 	case BPF_XDP:
3993 		return BPF_PROG_TYPE_XDP;
3994 	case BPF_LSM_CGROUP:
3995 		return BPF_PROG_TYPE_LSM;
3996 	case BPF_TCX_INGRESS:
3997 	case BPF_TCX_EGRESS:
3998 	case BPF_NETKIT_PRIMARY:
3999 	case BPF_NETKIT_PEER:
4000 		return BPF_PROG_TYPE_SCHED_CLS;
4001 	default:
4002 		return BPF_PROG_TYPE_UNSPEC;
4003 	}
4004 }
4005 
bpf_prog_attach_check_attach_type(const struct bpf_prog * prog,enum bpf_attach_type attach_type)4006 static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
4007 					     enum bpf_attach_type attach_type)
4008 {
4009 	enum bpf_prog_type ptype;
4010 
4011 	switch (prog->type) {
4012 	case BPF_PROG_TYPE_CGROUP_SOCK:
4013 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4014 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4015 	case BPF_PROG_TYPE_SK_LOOKUP:
4016 		return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
4017 	case BPF_PROG_TYPE_CGROUP_SKB:
4018 		if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
4019 			/* cg-skb progs can be loaded by unpriv user.
4020 			 * check permissions at attach time.
4021 			 */
4022 			return -EPERM;
4023 
4024 		ptype = attach_type_to_prog_type(attach_type);
4025 		if (prog->type != ptype)
4026 			return -EINVAL;
4027 
4028 		return prog->enforce_expected_attach_type &&
4029 			prog->expected_attach_type != attach_type ?
4030 			-EINVAL : 0;
4031 	case BPF_PROG_TYPE_EXT:
4032 		return 0;
4033 	case BPF_PROG_TYPE_NETFILTER:
4034 		if (attach_type != BPF_NETFILTER)
4035 			return -EINVAL;
4036 		return 0;
4037 	case BPF_PROG_TYPE_PERF_EVENT:
4038 	case BPF_PROG_TYPE_TRACEPOINT:
4039 		if (attach_type != BPF_PERF_EVENT)
4040 			return -EINVAL;
4041 		return 0;
4042 	case BPF_PROG_TYPE_KPROBE:
4043 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
4044 		    attach_type != BPF_TRACE_KPROBE_MULTI)
4045 			return -EINVAL;
4046 		if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
4047 		    attach_type != BPF_TRACE_KPROBE_SESSION)
4048 			return -EINVAL;
4049 		if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
4050 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4051 			return -EINVAL;
4052 		if (attach_type != BPF_PERF_EVENT &&
4053 		    attach_type != BPF_TRACE_KPROBE_MULTI &&
4054 		    attach_type != BPF_TRACE_KPROBE_SESSION &&
4055 		    attach_type != BPF_TRACE_UPROBE_MULTI)
4056 			return -EINVAL;
4057 		return 0;
4058 	case BPF_PROG_TYPE_SCHED_CLS:
4059 		if (attach_type != BPF_TCX_INGRESS &&
4060 		    attach_type != BPF_TCX_EGRESS &&
4061 		    attach_type != BPF_NETKIT_PRIMARY &&
4062 		    attach_type != BPF_NETKIT_PEER)
4063 			return -EINVAL;
4064 		return 0;
4065 	default:
4066 		ptype = attach_type_to_prog_type(attach_type);
4067 		if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
4068 			return -EINVAL;
4069 		return 0;
4070 	}
4071 }
4072 
4073 #define BPF_PROG_ATTACH_LAST_FIELD expected_revision
4074 
4075 #define BPF_F_ATTACH_MASK_BASE	\
4076 	(BPF_F_ALLOW_OVERRIDE |	\
4077 	 BPF_F_ALLOW_MULTI |	\
4078 	 BPF_F_REPLACE)
4079 
4080 #define BPF_F_ATTACH_MASK_MPROG	\
4081 	(BPF_F_REPLACE |	\
4082 	 BPF_F_BEFORE |		\
4083 	 BPF_F_AFTER |		\
4084 	 BPF_F_ID |		\
4085 	 BPF_F_LINK)
4086 
bpf_prog_attach(const union bpf_attr * attr)4087 static int bpf_prog_attach(const union bpf_attr *attr)
4088 {
4089 	enum bpf_prog_type ptype;
4090 	struct bpf_prog *prog;
4091 	int ret;
4092 
4093 	if (CHECK_ATTR(BPF_PROG_ATTACH))
4094 		return -EINVAL;
4095 
4096 	ptype = attach_type_to_prog_type(attr->attach_type);
4097 	if (ptype == BPF_PROG_TYPE_UNSPEC)
4098 		return -EINVAL;
4099 	if (bpf_mprog_supported(ptype)) {
4100 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4101 			return -EINVAL;
4102 	} else {
4103 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
4104 			return -EINVAL;
4105 		if (attr->relative_fd ||
4106 		    attr->expected_revision)
4107 			return -EINVAL;
4108 	}
4109 
4110 	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4111 	if (IS_ERR(prog))
4112 		return PTR_ERR(prog);
4113 
4114 	if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
4115 		bpf_prog_put(prog);
4116 		return -EINVAL;
4117 	}
4118 
4119 	switch (ptype) {
4120 	case BPF_PROG_TYPE_SK_SKB:
4121 	case BPF_PROG_TYPE_SK_MSG:
4122 		ret = sock_map_get_from_fd(attr, prog);
4123 		break;
4124 	case BPF_PROG_TYPE_LIRC_MODE2:
4125 		ret = lirc_prog_attach(attr, prog);
4126 		break;
4127 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4128 		ret = netns_bpf_prog_attach(attr, prog);
4129 		break;
4130 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4131 	case BPF_PROG_TYPE_CGROUP_SKB:
4132 	case BPF_PROG_TYPE_CGROUP_SOCK:
4133 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4134 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4135 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4136 	case BPF_PROG_TYPE_SOCK_OPS:
4137 	case BPF_PROG_TYPE_LSM:
4138 		if (ptype == BPF_PROG_TYPE_LSM &&
4139 		    prog->expected_attach_type != BPF_LSM_CGROUP)
4140 			ret = -EINVAL;
4141 		else
4142 			ret = cgroup_bpf_prog_attach(attr, ptype, prog);
4143 		break;
4144 	case BPF_PROG_TYPE_SCHED_CLS:
4145 		if (attr->attach_type == BPF_TCX_INGRESS ||
4146 		    attr->attach_type == BPF_TCX_EGRESS)
4147 			ret = tcx_prog_attach(attr, prog);
4148 		else
4149 			ret = netkit_prog_attach(attr, prog);
4150 		break;
4151 	default:
4152 		ret = -EINVAL;
4153 	}
4154 
4155 	if (ret)
4156 		bpf_prog_put(prog);
4157 	return ret;
4158 }
4159 
4160 #define BPF_PROG_DETACH_LAST_FIELD expected_revision
4161 
bpf_prog_detach(const union bpf_attr * attr)4162 static int bpf_prog_detach(const union bpf_attr *attr)
4163 {
4164 	struct bpf_prog *prog = NULL;
4165 	enum bpf_prog_type ptype;
4166 	int ret;
4167 
4168 	if (CHECK_ATTR(BPF_PROG_DETACH))
4169 		return -EINVAL;
4170 
4171 	ptype = attach_type_to_prog_type(attr->attach_type);
4172 	if (bpf_mprog_supported(ptype)) {
4173 		if (ptype == BPF_PROG_TYPE_UNSPEC)
4174 			return -EINVAL;
4175 		if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
4176 			return -EINVAL;
4177 		if (attr->attach_bpf_fd) {
4178 			prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
4179 			if (IS_ERR(prog))
4180 				return PTR_ERR(prog);
4181 		}
4182 	} else if (attr->attach_flags ||
4183 		   attr->relative_fd ||
4184 		   attr->expected_revision) {
4185 		return -EINVAL;
4186 	}
4187 
4188 	switch (ptype) {
4189 	case BPF_PROG_TYPE_SK_MSG:
4190 	case BPF_PROG_TYPE_SK_SKB:
4191 		ret = sock_map_prog_detach(attr, ptype);
4192 		break;
4193 	case BPF_PROG_TYPE_LIRC_MODE2:
4194 		ret = lirc_prog_detach(attr);
4195 		break;
4196 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
4197 		ret = netns_bpf_prog_detach(attr, ptype);
4198 		break;
4199 	case BPF_PROG_TYPE_CGROUP_DEVICE:
4200 	case BPF_PROG_TYPE_CGROUP_SKB:
4201 	case BPF_PROG_TYPE_CGROUP_SOCK:
4202 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
4203 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
4204 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
4205 	case BPF_PROG_TYPE_SOCK_OPS:
4206 	case BPF_PROG_TYPE_LSM:
4207 		ret = cgroup_bpf_prog_detach(attr, ptype);
4208 		break;
4209 	case BPF_PROG_TYPE_SCHED_CLS:
4210 		if (attr->attach_type == BPF_TCX_INGRESS ||
4211 		    attr->attach_type == BPF_TCX_EGRESS)
4212 			ret = tcx_prog_detach(attr, prog);
4213 		else
4214 			ret = netkit_prog_detach(attr, prog);
4215 		break;
4216 	default:
4217 		ret = -EINVAL;
4218 	}
4219 
4220 	if (prog)
4221 		bpf_prog_put(prog);
4222 	return ret;
4223 }
4224 
4225 #define BPF_PROG_QUERY_LAST_FIELD query.revision
4226 
bpf_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)4227 static int bpf_prog_query(const union bpf_attr *attr,
4228 			  union bpf_attr __user *uattr)
4229 {
4230 	if (!bpf_net_capable())
4231 		return -EPERM;
4232 	if (CHECK_ATTR(BPF_PROG_QUERY))
4233 		return -EINVAL;
4234 	if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
4235 		return -EINVAL;
4236 
4237 	switch (attr->query.attach_type) {
4238 	case BPF_CGROUP_INET_INGRESS:
4239 	case BPF_CGROUP_INET_EGRESS:
4240 	case BPF_CGROUP_INET_SOCK_CREATE:
4241 	case BPF_CGROUP_INET_SOCK_RELEASE:
4242 	case BPF_CGROUP_INET4_BIND:
4243 	case BPF_CGROUP_INET6_BIND:
4244 	case BPF_CGROUP_INET4_POST_BIND:
4245 	case BPF_CGROUP_INET6_POST_BIND:
4246 	case BPF_CGROUP_INET4_CONNECT:
4247 	case BPF_CGROUP_INET6_CONNECT:
4248 	case BPF_CGROUP_UNIX_CONNECT:
4249 	case BPF_CGROUP_INET4_GETPEERNAME:
4250 	case BPF_CGROUP_INET6_GETPEERNAME:
4251 	case BPF_CGROUP_UNIX_GETPEERNAME:
4252 	case BPF_CGROUP_INET4_GETSOCKNAME:
4253 	case BPF_CGROUP_INET6_GETSOCKNAME:
4254 	case BPF_CGROUP_UNIX_GETSOCKNAME:
4255 	case BPF_CGROUP_UDP4_SENDMSG:
4256 	case BPF_CGROUP_UDP6_SENDMSG:
4257 	case BPF_CGROUP_UNIX_SENDMSG:
4258 	case BPF_CGROUP_UDP4_RECVMSG:
4259 	case BPF_CGROUP_UDP6_RECVMSG:
4260 	case BPF_CGROUP_UNIX_RECVMSG:
4261 	case BPF_CGROUP_SOCK_OPS:
4262 	case BPF_CGROUP_DEVICE:
4263 	case BPF_CGROUP_SYSCTL:
4264 	case BPF_CGROUP_GETSOCKOPT:
4265 	case BPF_CGROUP_SETSOCKOPT:
4266 	case BPF_LSM_CGROUP:
4267 		return cgroup_bpf_prog_query(attr, uattr);
4268 	case BPF_LIRC_MODE2:
4269 		return lirc_prog_query(attr, uattr);
4270 	case BPF_FLOW_DISSECTOR:
4271 	case BPF_SK_LOOKUP:
4272 		return netns_bpf_prog_query(attr, uattr);
4273 	case BPF_SK_SKB_STREAM_PARSER:
4274 	case BPF_SK_SKB_STREAM_VERDICT:
4275 	case BPF_SK_MSG_VERDICT:
4276 	case BPF_SK_SKB_VERDICT:
4277 		return sock_map_bpf_prog_query(attr, uattr);
4278 	case BPF_TCX_INGRESS:
4279 	case BPF_TCX_EGRESS:
4280 		return tcx_prog_query(attr, uattr);
4281 	case BPF_NETKIT_PRIMARY:
4282 	case BPF_NETKIT_PEER:
4283 		return netkit_prog_query(attr, uattr);
4284 	default:
4285 		return -EINVAL;
4286 	}
4287 }
4288 
4289 #define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
4290 
bpf_prog_test_run(const union bpf_attr * attr,union bpf_attr __user * uattr)4291 static int bpf_prog_test_run(const union bpf_attr *attr,
4292 			     union bpf_attr __user *uattr)
4293 {
4294 	struct bpf_prog *prog;
4295 	int ret = -ENOTSUPP;
4296 
4297 	if (CHECK_ATTR(BPF_PROG_TEST_RUN))
4298 		return -EINVAL;
4299 
4300 	if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
4301 	    (!attr->test.ctx_size_in && attr->test.ctx_in))
4302 		return -EINVAL;
4303 
4304 	if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
4305 	    (!attr->test.ctx_size_out && attr->test.ctx_out))
4306 		return -EINVAL;
4307 
4308 	prog = bpf_prog_get(attr->test.prog_fd);
4309 	if (IS_ERR(prog))
4310 		return PTR_ERR(prog);
4311 
4312 	if (prog->aux->ops->test_run)
4313 		ret = prog->aux->ops->test_run(prog, attr, uattr);
4314 
4315 	bpf_prog_put(prog);
4316 	return ret;
4317 }
4318 
4319 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
4320 
bpf_obj_get_next_id(const union bpf_attr * attr,union bpf_attr __user * uattr,struct idr * idr,spinlock_t * lock)4321 static int bpf_obj_get_next_id(const union bpf_attr *attr,
4322 			       union bpf_attr __user *uattr,
4323 			       struct idr *idr,
4324 			       spinlock_t *lock)
4325 {
4326 	u32 next_id = attr->start_id;
4327 	int err = 0;
4328 
4329 	if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
4330 		return -EINVAL;
4331 
4332 	if (!capable(CAP_SYS_ADMIN))
4333 		return -EPERM;
4334 
4335 	next_id++;
4336 	spin_lock_bh(lock);
4337 	if (!idr_get_next(idr, &next_id))
4338 		err = -ENOENT;
4339 	spin_unlock_bh(lock);
4340 
4341 	if (!err)
4342 		err = put_user(next_id, &uattr->next_id);
4343 
4344 	return err;
4345 }
4346 
bpf_map_get_curr_or_next(u32 * id)4347 struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
4348 {
4349 	struct bpf_map *map;
4350 
4351 	spin_lock_bh(&map_idr_lock);
4352 again:
4353 	map = idr_get_next(&map_idr, id);
4354 	if (map) {
4355 		map = __bpf_map_inc_not_zero(map, false);
4356 		if (IS_ERR(map)) {
4357 			(*id)++;
4358 			goto again;
4359 		}
4360 	}
4361 	spin_unlock_bh(&map_idr_lock);
4362 
4363 	return map;
4364 }
4365 
bpf_prog_get_curr_or_next(u32 * id)4366 struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
4367 {
4368 	struct bpf_prog *prog;
4369 
4370 	spin_lock_bh(&prog_idr_lock);
4371 again:
4372 	prog = idr_get_next(&prog_idr, id);
4373 	if (prog) {
4374 		prog = bpf_prog_inc_not_zero(prog);
4375 		if (IS_ERR(prog)) {
4376 			(*id)++;
4377 			goto again;
4378 		}
4379 	}
4380 	spin_unlock_bh(&prog_idr_lock);
4381 
4382 	return prog;
4383 }
4384 
4385 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
4386 
bpf_prog_by_id(u32 id)4387 struct bpf_prog *bpf_prog_by_id(u32 id)
4388 {
4389 	struct bpf_prog *prog;
4390 
4391 	if (!id)
4392 		return ERR_PTR(-ENOENT);
4393 
4394 	spin_lock_bh(&prog_idr_lock);
4395 	prog = idr_find(&prog_idr, id);
4396 	if (prog)
4397 		prog = bpf_prog_inc_not_zero(prog);
4398 	else
4399 		prog = ERR_PTR(-ENOENT);
4400 	spin_unlock_bh(&prog_idr_lock);
4401 	return prog;
4402 }
4403 
bpf_prog_get_fd_by_id(const union bpf_attr * attr)4404 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
4405 {
4406 	struct bpf_prog *prog;
4407 	u32 id = attr->prog_id;
4408 	int fd;
4409 
4410 	if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
4411 		return -EINVAL;
4412 
4413 	if (!capable(CAP_SYS_ADMIN))
4414 		return -EPERM;
4415 
4416 	prog = bpf_prog_by_id(id);
4417 	if (IS_ERR(prog))
4418 		return PTR_ERR(prog);
4419 
4420 	fd = bpf_prog_new_fd(prog);
4421 	if (fd < 0)
4422 		bpf_prog_put(prog);
4423 
4424 	return fd;
4425 }
4426 
4427 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
4428 
bpf_map_get_fd_by_id(const union bpf_attr * attr)4429 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
4430 {
4431 	struct bpf_map *map;
4432 	u32 id = attr->map_id;
4433 	int f_flags;
4434 	int fd;
4435 
4436 	if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
4437 	    attr->open_flags & ~BPF_OBJ_FLAG_MASK)
4438 		return -EINVAL;
4439 
4440 	if (!capable(CAP_SYS_ADMIN))
4441 		return -EPERM;
4442 
4443 	f_flags = bpf_get_file_flag(attr->open_flags);
4444 	if (f_flags < 0)
4445 		return f_flags;
4446 
4447 	spin_lock_bh(&map_idr_lock);
4448 	map = idr_find(&map_idr, id);
4449 	if (map)
4450 		map = __bpf_map_inc_not_zero(map, true);
4451 	else
4452 		map = ERR_PTR(-ENOENT);
4453 	spin_unlock_bh(&map_idr_lock);
4454 
4455 	if (IS_ERR(map))
4456 		return PTR_ERR(map);
4457 
4458 	fd = bpf_map_new_fd(map, f_flags);
4459 	if (fd < 0)
4460 		bpf_map_put_with_uref(map);
4461 
4462 	return fd;
4463 }
4464 
bpf_map_from_imm(const struct bpf_prog * prog,unsigned long addr,u32 * off,u32 * type)4465 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
4466 					      unsigned long addr, u32 *off,
4467 					      u32 *type)
4468 {
4469 	const struct bpf_map *map;
4470 	int i;
4471 
4472 	mutex_lock(&prog->aux->used_maps_mutex);
4473 	for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
4474 		map = prog->aux->used_maps[i];
4475 		if (map == (void *)addr) {
4476 			*type = BPF_PSEUDO_MAP_FD;
4477 			goto out;
4478 		}
4479 		if (!map->ops->map_direct_value_meta)
4480 			continue;
4481 		if (!map->ops->map_direct_value_meta(map, addr, off)) {
4482 			*type = BPF_PSEUDO_MAP_VALUE;
4483 			goto out;
4484 		}
4485 	}
4486 	map = NULL;
4487 
4488 out:
4489 	mutex_unlock(&prog->aux->used_maps_mutex);
4490 	return map;
4491 }
4492 
bpf_insn_prepare_dump(const struct bpf_prog * prog,const struct cred * f_cred)4493 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
4494 					      const struct cred *f_cred)
4495 {
4496 	const struct bpf_map *map;
4497 	struct bpf_insn *insns;
4498 	u32 off, type;
4499 	u64 imm;
4500 	u8 code;
4501 	int i;
4502 
4503 	insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
4504 			GFP_USER);
4505 	if (!insns)
4506 		return insns;
4507 
4508 	for (i = 0; i < prog->len; i++) {
4509 		code = insns[i].code;
4510 
4511 		if (code == (BPF_JMP | BPF_TAIL_CALL)) {
4512 			insns[i].code = BPF_JMP | BPF_CALL;
4513 			insns[i].imm = BPF_FUNC_tail_call;
4514 			/* fall-through */
4515 		}
4516 		if (code == (BPF_JMP | BPF_CALL) ||
4517 		    code == (BPF_JMP | BPF_CALL_ARGS)) {
4518 			if (code == (BPF_JMP | BPF_CALL_ARGS))
4519 				insns[i].code = BPF_JMP | BPF_CALL;
4520 			if (!bpf_dump_raw_ok(f_cred))
4521 				insns[i].imm = 0;
4522 			continue;
4523 		}
4524 		if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
4525 			insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
4526 			continue;
4527 		}
4528 
4529 		if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
4530 		     BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
4531 			insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
4532 			continue;
4533 		}
4534 
4535 		if (code != (BPF_LD | BPF_IMM | BPF_DW))
4536 			continue;
4537 
4538 		imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
4539 		map = bpf_map_from_imm(prog, imm, &off, &type);
4540 		if (map) {
4541 			insns[i].src_reg = type;
4542 			insns[i].imm = map->id;
4543 			insns[i + 1].imm = off;
4544 			continue;
4545 		}
4546 	}
4547 
4548 	return insns;
4549 }
4550 
set_info_rec_size(struct bpf_prog_info * info)4551 static int set_info_rec_size(struct bpf_prog_info *info)
4552 {
4553 	/*
4554 	 * Ensure info.*_rec_size is the same as kernel expected size
4555 	 *
4556 	 * or
4557 	 *
4558 	 * Only allow zero *_rec_size if both _rec_size and _cnt are
4559 	 * zero.  In this case, the kernel will set the expected
4560 	 * _rec_size back to the info.
4561 	 */
4562 
4563 	if ((info->nr_func_info || info->func_info_rec_size) &&
4564 	    info->func_info_rec_size != sizeof(struct bpf_func_info))
4565 		return -EINVAL;
4566 
4567 	if ((info->nr_line_info || info->line_info_rec_size) &&
4568 	    info->line_info_rec_size != sizeof(struct bpf_line_info))
4569 		return -EINVAL;
4570 
4571 	if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
4572 	    info->jited_line_info_rec_size != sizeof(__u64))
4573 		return -EINVAL;
4574 
4575 	info->func_info_rec_size = sizeof(struct bpf_func_info);
4576 	info->line_info_rec_size = sizeof(struct bpf_line_info);
4577 	info->jited_line_info_rec_size = sizeof(__u64);
4578 
4579 	return 0;
4580 }
4581 
bpf_prog_get_info_by_fd(struct file * file,struct bpf_prog * prog,const union bpf_attr * attr,union bpf_attr __user * uattr)4582 static int bpf_prog_get_info_by_fd(struct file *file,
4583 				   struct bpf_prog *prog,
4584 				   const union bpf_attr *attr,
4585 				   union bpf_attr __user *uattr)
4586 {
4587 	struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4588 	struct btf *attach_btf = bpf_prog_get_target_btf(prog);
4589 	struct bpf_prog_info info;
4590 	u32 info_len = attr->info.info_len;
4591 	struct bpf_prog_kstats stats;
4592 	char __user *uinsns;
4593 	u32 ulen;
4594 	int err;
4595 
4596 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4597 	if (err)
4598 		return err;
4599 	info_len = min_t(u32, sizeof(info), info_len);
4600 
4601 	memset(&info, 0, sizeof(info));
4602 	if (copy_from_user(&info, uinfo, info_len))
4603 		return -EFAULT;
4604 
4605 	info.type = prog->type;
4606 	info.id = prog->aux->id;
4607 	info.load_time = prog->aux->load_time;
4608 	info.created_by_uid = from_kuid_munged(current_user_ns(),
4609 					       prog->aux->user->uid);
4610 	info.gpl_compatible = prog->gpl_compatible;
4611 
4612 	memcpy(info.tag, prog->tag, sizeof(prog->tag));
4613 	memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
4614 
4615 	mutex_lock(&prog->aux->used_maps_mutex);
4616 	ulen = info.nr_map_ids;
4617 	info.nr_map_ids = prog->aux->used_map_cnt;
4618 	ulen = min_t(u32, info.nr_map_ids, ulen);
4619 	if (ulen) {
4620 		u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
4621 		u32 i;
4622 
4623 		for (i = 0; i < ulen; i++)
4624 			if (put_user(prog->aux->used_maps[i]->id,
4625 				     &user_map_ids[i])) {
4626 				mutex_unlock(&prog->aux->used_maps_mutex);
4627 				return -EFAULT;
4628 			}
4629 	}
4630 	mutex_unlock(&prog->aux->used_maps_mutex);
4631 
4632 	err = set_info_rec_size(&info);
4633 	if (err)
4634 		return err;
4635 
4636 	bpf_prog_get_stats(prog, &stats);
4637 	info.run_time_ns = stats.nsecs;
4638 	info.run_cnt = stats.cnt;
4639 	info.recursion_misses = stats.misses;
4640 
4641 	info.verified_insns = prog->aux->verified_insns;
4642 
4643 	if (!bpf_capable()) {
4644 		info.jited_prog_len = 0;
4645 		info.xlated_prog_len = 0;
4646 		info.nr_jited_ksyms = 0;
4647 		info.nr_jited_func_lens = 0;
4648 		info.nr_func_info = 0;
4649 		info.nr_line_info = 0;
4650 		info.nr_jited_line_info = 0;
4651 		goto done;
4652 	}
4653 
4654 	ulen = info.xlated_prog_len;
4655 	info.xlated_prog_len = bpf_prog_insn_size(prog);
4656 	if (info.xlated_prog_len && ulen) {
4657 		struct bpf_insn *insns_sanitized;
4658 		bool fault;
4659 
4660 		if (prog->blinded && !bpf_dump_raw_ok(file->f_cred)) {
4661 			info.xlated_prog_insns = 0;
4662 			goto done;
4663 		}
4664 		insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
4665 		if (!insns_sanitized)
4666 			return -ENOMEM;
4667 		uinsns = u64_to_user_ptr(info.xlated_prog_insns);
4668 		ulen = min_t(u32, info.xlated_prog_len, ulen);
4669 		fault = copy_to_user(uinsns, insns_sanitized, ulen);
4670 		kfree(insns_sanitized);
4671 		if (fault)
4672 			return -EFAULT;
4673 	}
4674 
4675 	if (bpf_prog_is_offloaded(prog->aux)) {
4676 		err = bpf_prog_offload_info_fill(&info, prog);
4677 		if (err)
4678 			return err;
4679 		goto done;
4680 	}
4681 
4682 	/* NOTE: the following code is supposed to be skipped for offload.
4683 	 * bpf_prog_offload_info_fill() is the place to fill similar fields
4684 	 * for offload.
4685 	 */
4686 	ulen = info.jited_prog_len;
4687 	if (prog->aux->func_cnt) {
4688 		u32 i;
4689 
4690 		info.jited_prog_len = 0;
4691 		for (i = 0; i < prog->aux->func_cnt; i++)
4692 			info.jited_prog_len += prog->aux->func[i]->jited_len;
4693 	} else {
4694 		info.jited_prog_len = prog->jited_len;
4695 	}
4696 
4697 	if (info.jited_prog_len && ulen) {
4698 		if (bpf_dump_raw_ok(file->f_cred)) {
4699 			uinsns = u64_to_user_ptr(info.jited_prog_insns);
4700 			ulen = min_t(u32, info.jited_prog_len, ulen);
4701 
4702 			/* for multi-function programs, copy the JITed
4703 			 * instructions for all the functions
4704 			 */
4705 			if (prog->aux->func_cnt) {
4706 				u32 len, free, i;
4707 				u8 *img;
4708 
4709 				free = ulen;
4710 				for (i = 0; i < prog->aux->func_cnt; i++) {
4711 					len = prog->aux->func[i]->jited_len;
4712 					len = min_t(u32, len, free);
4713 					img = (u8 *) prog->aux->func[i]->bpf_func;
4714 					if (copy_to_user(uinsns, img, len))
4715 						return -EFAULT;
4716 					uinsns += len;
4717 					free -= len;
4718 					if (!free)
4719 						break;
4720 				}
4721 			} else {
4722 				if (copy_to_user(uinsns, prog->bpf_func, ulen))
4723 					return -EFAULT;
4724 			}
4725 		} else {
4726 			info.jited_prog_insns = 0;
4727 		}
4728 	}
4729 
4730 	ulen = info.nr_jited_ksyms;
4731 	info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
4732 	if (ulen) {
4733 		if (bpf_dump_raw_ok(file->f_cred)) {
4734 			unsigned long ksym_addr;
4735 			u64 __user *user_ksyms;
4736 			u32 i;
4737 
4738 			/* copy the address of the kernel symbol
4739 			 * corresponding to each function
4740 			 */
4741 			ulen = min_t(u32, info.nr_jited_ksyms, ulen);
4742 			user_ksyms = u64_to_user_ptr(info.jited_ksyms);
4743 			if (prog->aux->func_cnt) {
4744 				for (i = 0; i < ulen; i++) {
4745 					ksym_addr = (unsigned long)
4746 						prog->aux->func[i]->bpf_func;
4747 					if (put_user((u64) ksym_addr,
4748 						     &user_ksyms[i]))
4749 						return -EFAULT;
4750 				}
4751 			} else {
4752 				ksym_addr = (unsigned long) prog->bpf_func;
4753 				if (put_user((u64) ksym_addr, &user_ksyms[0]))
4754 					return -EFAULT;
4755 			}
4756 		} else {
4757 			info.jited_ksyms = 0;
4758 		}
4759 	}
4760 
4761 	ulen = info.nr_jited_func_lens;
4762 	info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
4763 	if (ulen) {
4764 		if (bpf_dump_raw_ok(file->f_cred)) {
4765 			u32 __user *user_lens;
4766 			u32 func_len, i;
4767 
4768 			/* copy the JITed image lengths for each function */
4769 			ulen = min_t(u32, info.nr_jited_func_lens, ulen);
4770 			user_lens = u64_to_user_ptr(info.jited_func_lens);
4771 			if (prog->aux->func_cnt) {
4772 				for (i = 0; i < ulen; i++) {
4773 					func_len =
4774 						prog->aux->func[i]->jited_len;
4775 					if (put_user(func_len, &user_lens[i]))
4776 						return -EFAULT;
4777 				}
4778 			} else {
4779 				func_len = prog->jited_len;
4780 				if (put_user(func_len, &user_lens[0]))
4781 					return -EFAULT;
4782 			}
4783 		} else {
4784 			info.jited_func_lens = 0;
4785 		}
4786 	}
4787 
4788 	if (prog->aux->btf)
4789 		info.btf_id = btf_obj_id(prog->aux->btf);
4790 	info.attach_btf_id = prog->aux->attach_btf_id;
4791 	if (attach_btf)
4792 		info.attach_btf_obj_id = btf_obj_id(attach_btf);
4793 
4794 	ulen = info.nr_func_info;
4795 	info.nr_func_info = prog->aux->func_info_cnt;
4796 	if (info.nr_func_info && ulen) {
4797 		char __user *user_finfo;
4798 
4799 		user_finfo = u64_to_user_ptr(info.func_info);
4800 		ulen = min_t(u32, info.nr_func_info, ulen);
4801 		if (copy_to_user(user_finfo, prog->aux->func_info,
4802 				 info.func_info_rec_size * ulen))
4803 			return -EFAULT;
4804 	}
4805 
4806 	ulen = info.nr_line_info;
4807 	info.nr_line_info = prog->aux->nr_linfo;
4808 	if (info.nr_line_info && ulen) {
4809 		__u8 __user *user_linfo;
4810 
4811 		user_linfo = u64_to_user_ptr(info.line_info);
4812 		ulen = min_t(u32, info.nr_line_info, ulen);
4813 		if (copy_to_user(user_linfo, prog->aux->linfo,
4814 				 info.line_info_rec_size * ulen))
4815 			return -EFAULT;
4816 	}
4817 
4818 	ulen = info.nr_jited_line_info;
4819 	if (prog->aux->jited_linfo)
4820 		info.nr_jited_line_info = prog->aux->nr_linfo;
4821 	else
4822 		info.nr_jited_line_info = 0;
4823 	if (info.nr_jited_line_info && ulen) {
4824 		if (bpf_dump_raw_ok(file->f_cred)) {
4825 			unsigned long line_addr;
4826 			__u64 __user *user_linfo;
4827 			u32 i;
4828 
4829 			user_linfo = u64_to_user_ptr(info.jited_line_info);
4830 			ulen = min_t(u32, info.nr_jited_line_info, ulen);
4831 			for (i = 0; i < ulen; i++) {
4832 				line_addr = (unsigned long)prog->aux->jited_linfo[i];
4833 				if (put_user((__u64)line_addr, &user_linfo[i]))
4834 					return -EFAULT;
4835 			}
4836 		} else {
4837 			info.jited_line_info = 0;
4838 		}
4839 	}
4840 
4841 	ulen = info.nr_prog_tags;
4842 	info.nr_prog_tags = prog->aux->func_cnt ? : 1;
4843 	if (ulen) {
4844 		__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
4845 		u32 i;
4846 
4847 		user_prog_tags = u64_to_user_ptr(info.prog_tags);
4848 		ulen = min_t(u32, info.nr_prog_tags, ulen);
4849 		if (prog->aux->func_cnt) {
4850 			for (i = 0; i < ulen; i++) {
4851 				if (copy_to_user(user_prog_tags[i],
4852 						 prog->aux->func[i]->tag,
4853 						 BPF_TAG_SIZE))
4854 					return -EFAULT;
4855 			}
4856 		} else {
4857 			if (copy_to_user(user_prog_tags[0],
4858 					 prog->tag, BPF_TAG_SIZE))
4859 				return -EFAULT;
4860 		}
4861 	}
4862 
4863 done:
4864 	if (copy_to_user(uinfo, &info, info_len) ||
4865 	    put_user(info_len, &uattr->info.info_len))
4866 		return -EFAULT;
4867 
4868 	return 0;
4869 }
4870 
bpf_map_get_info_by_fd(struct file * file,struct bpf_map * map,const union bpf_attr * attr,union bpf_attr __user * uattr)4871 static int bpf_map_get_info_by_fd(struct file *file,
4872 				  struct bpf_map *map,
4873 				  const union bpf_attr *attr,
4874 				  union bpf_attr __user *uattr)
4875 {
4876 	struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4877 	struct bpf_map_info info;
4878 	u32 info_len = attr->info.info_len;
4879 	int err;
4880 
4881 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4882 	if (err)
4883 		return err;
4884 	info_len = min_t(u32, sizeof(info), info_len);
4885 
4886 	memset(&info, 0, sizeof(info));
4887 	info.type = map->map_type;
4888 	info.id = map->id;
4889 	info.key_size = map->key_size;
4890 	info.value_size = map->value_size;
4891 	info.max_entries = map->max_entries;
4892 	info.map_flags = map->map_flags;
4893 	info.map_extra = map->map_extra;
4894 	memcpy(info.name, map->name, sizeof(map->name));
4895 
4896 	if (map->btf) {
4897 		info.btf_id = btf_obj_id(map->btf);
4898 		info.btf_key_type_id = map->btf_key_type_id;
4899 		info.btf_value_type_id = map->btf_value_type_id;
4900 	}
4901 	info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
4902 	if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
4903 		bpf_map_struct_ops_info_fill(&info, map);
4904 
4905 	if (bpf_map_is_offloaded(map)) {
4906 		err = bpf_map_offload_info_fill(&info, map);
4907 		if (err)
4908 			return err;
4909 	}
4910 
4911 	if (copy_to_user(uinfo, &info, info_len) ||
4912 	    put_user(info_len, &uattr->info.info_len))
4913 		return -EFAULT;
4914 
4915 	return 0;
4916 }
4917 
bpf_btf_get_info_by_fd(struct file * file,struct btf * btf,const union bpf_attr * attr,union bpf_attr __user * uattr)4918 static int bpf_btf_get_info_by_fd(struct file *file,
4919 				  struct btf *btf,
4920 				  const union bpf_attr *attr,
4921 				  union bpf_attr __user *uattr)
4922 {
4923 	struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4924 	u32 info_len = attr->info.info_len;
4925 	int err;
4926 
4927 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
4928 	if (err)
4929 		return err;
4930 
4931 	return btf_get_info_by_fd(btf, attr, uattr);
4932 }
4933 
bpf_link_get_info_by_fd(struct file * file,struct bpf_link * link,const union bpf_attr * attr,union bpf_attr __user * uattr)4934 static int bpf_link_get_info_by_fd(struct file *file,
4935 				  struct bpf_link *link,
4936 				  const union bpf_attr *attr,
4937 				  union bpf_attr __user *uattr)
4938 {
4939 	struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
4940 	struct bpf_link_info info;
4941 	u32 info_len = attr->info.info_len;
4942 	int err;
4943 
4944 	err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
4945 	if (err)
4946 		return err;
4947 	info_len = min_t(u32, sizeof(info), info_len);
4948 
4949 	memset(&info, 0, sizeof(info));
4950 	if (copy_from_user(&info, uinfo, info_len))
4951 		return -EFAULT;
4952 
4953 	info.type = link->type;
4954 	info.id = link->id;
4955 	if (link->prog)
4956 		info.prog_id = link->prog->aux->id;
4957 
4958 	if (link->ops->fill_link_info) {
4959 		err = link->ops->fill_link_info(link, &info);
4960 		if (err)
4961 			return err;
4962 	}
4963 
4964 	if (copy_to_user(uinfo, &info, info_len) ||
4965 	    put_user(info_len, &uattr->info.info_len))
4966 		return -EFAULT;
4967 
4968 	return 0;
4969 }
4970 
4971 
4972 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
4973 
bpf_obj_get_info_by_fd(const union bpf_attr * attr,union bpf_attr __user * uattr)4974 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
4975 				  union bpf_attr __user *uattr)
4976 {
4977 	int ufd = attr->info.bpf_fd;
4978 	struct fd f;
4979 	int err;
4980 
4981 	if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
4982 		return -EINVAL;
4983 
4984 	f = fdget(ufd);
4985 	if (!f.file)
4986 		return -EBADFD;
4987 
4988 	if (f.file->f_op == &bpf_prog_fops)
4989 		err = bpf_prog_get_info_by_fd(f.file, f.file->private_data, attr,
4990 					      uattr);
4991 	else if (f.file->f_op == &bpf_map_fops)
4992 		err = bpf_map_get_info_by_fd(f.file, f.file->private_data, attr,
4993 					     uattr);
4994 	else if (f.file->f_op == &btf_fops)
4995 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
4996 	else if (f.file->f_op == &bpf_link_fops || f.file->f_op == &bpf_link_fops_poll)
4997 		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
4998 					      attr, uattr);
4999 	else
5000 		err = -EINVAL;
5001 
5002 	fdput(f);
5003 	return err;
5004 }
5005 
5006 #define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
5007 
bpf_btf_load(const union bpf_attr * attr,bpfptr_t uattr,__u32 uattr_size)5008 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
5009 {
5010 	struct bpf_token *token = NULL;
5011 
5012 	if (CHECK_ATTR(BPF_BTF_LOAD))
5013 		return -EINVAL;
5014 
5015 	if (attr->btf_flags & ~BPF_F_TOKEN_FD)
5016 		return -EINVAL;
5017 
5018 	if (attr->btf_flags & BPF_F_TOKEN_FD) {
5019 		token = bpf_token_get_from_fd(attr->btf_token_fd);
5020 		if (IS_ERR(token))
5021 			return PTR_ERR(token);
5022 		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
5023 			bpf_token_put(token);
5024 			token = NULL;
5025 		}
5026 	}
5027 
5028 	if (!bpf_token_capable(token, CAP_BPF)) {
5029 		bpf_token_put(token);
5030 		return -EPERM;
5031 	}
5032 
5033 	bpf_token_put(token);
5034 
5035 	return btf_new_fd(attr, uattr, uattr_size);
5036 }
5037 
5038 #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
5039 
bpf_btf_get_fd_by_id(const union bpf_attr * attr)5040 static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
5041 {
5042 	if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
5043 		return -EINVAL;
5044 
5045 	if (!capable(CAP_SYS_ADMIN))
5046 		return -EPERM;
5047 
5048 	return btf_get_fd_by_id(attr->btf_id);
5049 }
5050 
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)5051 static int bpf_task_fd_query_copy(const union bpf_attr *attr,
5052 				    union bpf_attr __user *uattr,
5053 				    u32 prog_id, u32 fd_type,
5054 				    const char *buf, u64 probe_offset,
5055 				    u64 probe_addr)
5056 {
5057 	char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
5058 	u32 len = buf ? strlen(buf) : 0, input_len;
5059 	int err = 0;
5060 
5061 	if (put_user(len, &uattr->task_fd_query.buf_len))
5062 		return -EFAULT;
5063 	input_len = attr->task_fd_query.buf_len;
5064 	if (input_len && ubuf) {
5065 		if (!len) {
5066 			/* nothing to copy, just make ubuf NULL terminated */
5067 			char zero = '\0';
5068 
5069 			if (put_user(zero, ubuf))
5070 				return -EFAULT;
5071 		} else if (input_len >= len + 1) {
5072 			/* ubuf can hold the string with NULL terminator */
5073 			if (copy_to_user(ubuf, buf, len + 1))
5074 				return -EFAULT;
5075 		} else {
5076 			/* ubuf cannot hold the string with NULL terminator,
5077 			 * do a partial copy with NULL terminator.
5078 			 */
5079 			char zero = '\0';
5080 
5081 			err = -ENOSPC;
5082 			if (copy_to_user(ubuf, buf, input_len - 1))
5083 				return -EFAULT;
5084 			if (put_user(zero, ubuf + input_len - 1))
5085 				return -EFAULT;
5086 		}
5087 	}
5088 
5089 	if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
5090 	    put_user(fd_type, &uattr->task_fd_query.fd_type) ||
5091 	    put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
5092 	    put_user(probe_addr, &uattr->task_fd_query.probe_addr))
5093 		return -EFAULT;
5094 
5095 	return err;
5096 }
5097 
5098 #define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
5099 
bpf_task_fd_query(const union bpf_attr * attr,union bpf_attr __user * uattr)5100 static int bpf_task_fd_query(const union bpf_attr *attr,
5101 			     union bpf_attr __user *uattr)
5102 {
5103 	pid_t pid = attr->task_fd_query.pid;
5104 	u32 fd = attr->task_fd_query.fd;
5105 	const struct perf_event *event;
5106 	struct task_struct *task;
5107 	struct file *file;
5108 	int err;
5109 
5110 	if (CHECK_ATTR(BPF_TASK_FD_QUERY))
5111 		return -EINVAL;
5112 
5113 	if (!capable(CAP_SYS_ADMIN))
5114 		return -EPERM;
5115 
5116 	if (attr->task_fd_query.flags != 0)
5117 		return -EINVAL;
5118 
5119 	rcu_read_lock();
5120 	task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
5121 	rcu_read_unlock();
5122 	if (!task)
5123 		return -ENOENT;
5124 
5125 	err = 0;
5126 	file = fget_task(task, fd);
5127 	put_task_struct(task);
5128 	if (!file)
5129 		return -EBADF;
5130 
5131 	if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
5132 		struct bpf_link *link = file->private_data;
5133 
5134 		if (link->ops == &bpf_raw_tp_link_lops) {
5135 			struct bpf_raw_tp_link *raw_tp =
5136 				container_of(link, struct bpf_raw_tp_link, link);
5137 			struct bpf_raw_event_map *btp = raw_tp->btp;
5138 
5139 			err = bpf_task_fd_query_copy(attr, uattr,
5140 						     raw_tp->link.prog->aux->id,
5141 						     BPF_FD_TYPE_RAW_TRACEPOINT,
5142 						     btp->tp->name, 0, 0);
5143 			goto put_file;
5144 		}
5145 		goto out_not_supp;
5146 	}
5147 
5148 	event = perf_get_event(file);
5149 	if (!IS_ERR(event)) {
5150 		u64 probe_offset, probe_addr;
5151 		u32 prog_id, fd_type;
5152 		const char *buf;
5153 
5154 		err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
5155 					      &buf, &probe_offset,
5156 					      &probe_addr, NULL);
5157 		if (!err)
5158 			err = bpf_task_fd_query_copy(attr, uattr, prog_id,
5159 						     fd_type, buf,
5160 						     probe_offset,
5161 						     probe_addr);
5162 		goto put_file;
5163 	}
5164 
5165 out_not_supp:
5166 	err = -ENOTSUPP;
5167 put_file:
5168 	fput(file);
5169 	return err;
5170 }
5171 
5172 #define BPF_MAP_BATCH_LAST_FIELD batch.flags
5173 
5174 #define BPF_DO_BATCH(fn, ...)			\
5175 	do {					\
5176 		if (!fn) {			\
5177 			err = -ENOTSUPP;	\
5178 			goto err_put;		\
5179 		}				\
5180 		err = fn(__VA_ARGS__);		\
5181 	} while (0)
5182 
bpf_map_do_batch(const union bpf_attr * attr,union bpf_attr __user * uattr,int cmd)5183 static int bpf_map_do_batch(const union bpf_attr *attr,
5184 			    union bpf_attr __user *uattr,
5185 			    int cmd)
5186 {
5187 	bool has_read  = cmd == BPF_MAP_LOOKUP_BATCH ||
5188 			 cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
5189 	bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
5190 	struct bpf_map *map;
5191 	int err, ufd;
5192 	struct fd f;
5193 
5194 	if (CHECK_ATTR(BPF_MAP_BATCH))
5195 		return -EINVAL;
5196 
5197 	ufd = attr->batch.map_fd;
5198 	f = fdget(ufd);
5199 	map = __bpf_map_get(f);
5200 	if (IS_ERR(map))
5201 		return PTR_ERR(map);
5202 	if (has_write)
5203 		bpf_map_write_active_inc(map);
5204 	if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
5205 		err = -EPERM;
5206 		goto err_put;
5207 	}
5208 	if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
5209 		err = -EPERM;
5210 		goto err_put;
5211 	}
5212 
5213 	if (cmd == BPF_MAP_LOOKUP_BATCH)
5214 		BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
5215 	else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
5216 		BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
5217 	else if (cmd == BPF_MAP_UPDATE_BATCH)
5218 		BPF_DO_BATCH(map->ops->map_update_batch, map, f.file, attr, uattr);
5219 	else
5220 		BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
5221 err_put:
5222 	if (has_write) {
5223 		maybe_wait_bpf_programs(map);
5224 		bpf_map_write_active_dec(map);
5225 	}
5226 	fdput(f);
5227 	return err;
5228 }
5229 
5230 #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
link_create(union bpf_attr * attr,bpfptr_t uattr)5231 static int link_create(union bpf_attr *attr, bpfptr_t uattr)
5232 {
5233 	struct bpf_prog *prog;
5234 	int ret;
5235 
5236 	if (CHECK_ATTR(BPF_LINK_CREATE))
5237 		return -EINVAL;
5238 
5239 	if (attr->link_create.attach_type == BPF_STRUCT_OPS)
5240 		return bpf_struct_ops_link_create(attr);
5241 
5242 	prog = bpf_prog_get(attr->link_create.prog_fd);
5243 	if (IS_ERR(prog))
5244 		return PTR_ERR(prog);
5245 
5246 	ret = bpf_prog_attach_check_attach_type(prog,
5247 						attr->link_create.attach_type);
5248 	if (ret)
5249 		goto out;
5250 
5251 	switch (prog->type) {
5252 	case BPF_PROG_TYPE_CGROUP_SKB:
5253 	case BPF_PROG_TYPE_CGROUP_SOCK:
5254 	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
5255 	case BPF_PROG_TYPE_SOCK_OPS:
5256 	case BPF_PROG_TYPE_CGROUP_DEVICE:
5257 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
5258 	case BPF_PROG_TYPE_CGROUP_SOCKOPT:
5259 		ret = cgroup_bpf_link_attach(attr, prog);
5260 		break;
5261 	case BPF_PROG_TYPE_EXT:
5262 		ret = bpf_tracing_prog_attach(prog,
5263 					      attr->link_create.target_fd,
5264 					      attr->link_create.target_btf_id,
5265 					      attr->link_create.tracing.cookie);
5266 		break;
5267 	case BPF_PROG_TYPE_LSM:
5268 	case BPF_PROG_TYPE_TRACING:
5269 		if (attr->link_create.attach_type != prog->expected_attach_type) {
5270 			ret = -EINVAL;
5271 			goto out;
5272 		}
5273 		if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
5274 			ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie);
5275 		else if (prog->expected_attach_type == BPF_TRACE_ITER)
5276 			ret = bpf_iter_link_attach(attr, uattr, prog);
5277 		else if (prog->expected_attach_type == BPF_LSM_CGROUP)
5278 			ret = cgroup_bpf_link_attach(attr, prog);
5279 		else
5280 			ret = bpf_tracing_prog_attach(prog,
5281 						      attr->link_create.target_fd,
5282 						      attr->link_create.target_btf_id,
5283 						      attr->link_create.tracing.cookie);
5284 		break;
5285 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
5286 	case BPF_PROG_TYPE_SK_LOOKUP:
5287 		ret = netns_bpf_link_create(attr, prog);
5288 		break;
5289 	case BPF_PROG_TYPE_SK_MSG:
5290 	case BPF_PROG_TYPE_SK_SKB:
5291 		ret = sock_map_link_create(attr, prog);
5292 		break;
5293 #ifdef CONFIG_NET
5294 	case BPF_PROG_TYPE_XDP:
5295 		ret = bpf_xdp_link_attach(attr, prog);
5296 		break;
5297 	case BPF_PROG_TYPE_SCHED_CLS:
5298 		if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
5299 		    attr->link_create.attach_type == BPF_TCX_EGRESS)
5300 			ret = tcx_link_attach(attr, prog);
5301 		else
5302 			ret = netkit_link_attach(attr, prog);
5303 		break;
5304 	case BPF_PROG_TYPE_NETFILTER:
5305 		ret = bpf_nf_link_attach(attr, prog);
5306 		break;
5307 #endif
5308 	case BPF_PROG_TYPE_PERF_EVENT:
5309 	case BPF_PROG_TYPE_TRACEPOINT:
5310 		ret = bpf_perf_link_attach(attr, prog);
5311 		break;
5312 	case BPF_PROG_TYPE_KPROBE:
5313 		if (attr->link_create.attach_type == BPF_PERF_EVENT)
5314 			ret = bpf_perf_link_attach(attr, prog);
5315 		else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
5316 			 attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
5317 			ret = bpf_kprobe_multi_link_attach(attr, prog);
5318 		else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI)
5319 			ret = bpf_uprobe_multi_link_attach(attr, prog);
5320 		break;
5321 	default:
5322 		ret = -EINVAL;
5323 	}
5324 
5325 out:
5326 	if (ret < 0)
5327 		bpf_prog_put(prog);
5328 	return ret;
5329 }
5330 
link_update_map(struct bpf_link * link,union bpf_attr * attr)5331 static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
5332 {
5333 	struct bpf_map *new_map, *old_map = NULL;
5334 	int ret;
5335 
5336 	new_map = bpf_map_get(attr->link_update.new_map_fd);
5337 	if (IS_ERR(new_map))
5338 		return PTR_ERR(new_map);
5339 
5340 	if (attr->link_update.flags & BPF_F_REPLACE) {
5341 		old_map = bpf_map_get(attr->link_update.old_map_fd);
5342 		if (IS_ERR(old_map)) {
5343 			ret = PTR_ERR(old_map);
5344 			goto out_put;
5345 		}
5346 	} else if (attr->link_update.old_map_fd) {
5347 		ret = -EINVAL;
5348 		goto out_put;
5349 	}
5350 
5351 	ret = link->ops->update_map(link, new_map, old_map);
5352 
5353 	if (old_map)
5354 		bpf_map_put(old_map);
5355 out_put:
5356 	bpf_map_put(new_map);
5357 	return ret;
5358 }
5359 
5360 #define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
5361 
link_update(union bpf_attr * attr)5362 static int link_update(union bpf_attr *attr)
5363 {
5364 	struct bpf_prog *old_prog = NULL, *new_prog;
5365 	struct bpf_link *link;
5366 	u32 flags;
5367 	int ret;
5368 
5369 	if (CHECK_ATTR(BPF_LINK_UPDATE))
5370 		return -EINVAL;
5371 
5372 	flags = attr->link_update.flags;
5373 	if (flags & ~BPF_F_REPLACE)
5374 		return -EINVAL;
5375 
5376 	link = bpf_link_get_from_fd(attr->link_update.link_fd);
5377 	if (IS_ERR(link))
5378 		return PTR_ERR(link);
5379 
5380 	if (link->ops->update_map) {
5381 		ret = link_update_map(link, attr);
5382 		goto out_put_link;
5383 	}
5384 
5385 	new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
5386 	if (IS_ERR(new_prog)) {
5387 		ret = PTR_ERR(new_prog);
5388 		goto out_put_link;
5389 	}
5390 
5391 	if (flags & BPF_F_REPLACE) {
5392 		old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
5393 		if (IS_ERR(old_prog)) {
5394 			ret = PTR_ERR(old_prog);
5395 			old_prog = NULL;
5396 			goto out_put_progs;
5397 		}
5398 	} else if (attr->link_update.old_prog_fd) {
5399 		ret = -EINVAL;
5400 		goto out_put_progs;
5401 	}
5402 
5403 	if (link->ops->update_prog)
5404 		ret = link->ops->update_prog(link, new_prog, old_prog);
5405 	else
5406 		ret = -EINVAL;
5407 
5408 out_put_progs:
5409 	if (old_prog)
5410 		bpf_prog_put(old_prog);
5411 	if (ret)
5412 		bpf_prog_put(new_prog);
5413 out_put_link:
5414 	bpf_link_put_direct(link);
5415 	return ret;
5416 }
5417 
5418 #define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
5419 
link_detach(union bpf_attr * attr)5420 static int link_detach(union bpf_attr *attr)
5421 {
5422 	struct bpf_link *link;
5423 	int ret;
5424 
5425 	if (CHECK_ATTR(BPF_LINK_DETACH))
5426 		return -EINVAL;
5427 
5428 	link = bpf_link_get_from_fd(attr->link_detach.link_fd);
5429 	if (IS_ERR(link))
5430 		return PTR_ERR(link);
5431 
5432 	if (link->ops->detach)
5433 		ret = link->ops->detach(link);
5434 	else
5435 		ret = -EOPNOTSUPP;
5436 
5437 	bpf_link_put_direct(link);
5438 	return ret;
5439 }
5440 
bpf_link_inc_not_zero(struct bpf_link * link)5441 struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
5442 {
5443 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
5444 }
5445 EXPORT_SYMBOL(bpf_link_inc_not_zero);
5446 
bpf_link_by_id(u32 id)5447 struct bpf_link *bpf_link_by_id(u32 id)
5448 {
5449 	struct bpf_link *link;
5450 
5451 	if (!id)
5452 		return ERR_PTR(-ENOENT);
5453 
5454 	spin_lock_bh(&link_idr_lock);
5455 	/* before link is "settled", ID is 0, pretend it doesn't exist yet */
5456 	link = idr_find(&link_idr, id);
5457 	if (link) {
5458 		if (link->id)
5459 			link = bpf_link_inc_not_zero(link);
5460 		else
5461 			link = ERR_PTR(-EAGAIN);
5462 	} else {
5463 		link = ERR_PTR(-ENOENT);
5464 	}
5465 	spin_unlock_bh(&link_idr_lock);
5466 	return link;
5467 }
5468 
bpf_link_get_curr_or_next(u32 * id)5469 struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
5470 {
5471 	struct bpf_link *link;
5472 
5473 	spin_lock_bh(&link_idr_lock);
5474 again:
5475 	link = idr_get_next(&link_idr, id);
5476 	if (link) {
5477 		link = bpf_link_inc_not_zero(link);
5478 		if (IS_ERR(link)) {
5479 			(*id)++;
5480 			goto again;
5481 		}
5482 	}
5483 	spin_unlock_bh(&link_idr_lock);
5484 
5485 	return link;
5486 }
5487 
5488 #define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
5489 
bpf_link_get_fd_by_id(const union bpf_attr * attr)5490 static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
5491 {
5492 	struct bpf_link *link;
5493 	u32 id = attr->link_id;
5494 	int fd;
5495 
5496 	if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
5497 		return -EINVAL;
5498 
5499 	if (!capable(CAP_SYS_ADMIN))
5500 		return -EPERM;
5501 
5502 	link = bpf_link_by_id(id);
5503 	if (IS_ERR(link))
5504 		return PTR_ERR(link);
5505 
5506 	fd = bpf_link_new_fd(link);
5507 	if (fd < 0)
5508 		bpf_link_put_direct(link);
5509 
5510 	return fd;
5511 }
5512 
5513 DEFINE_MUTEX(bpf_stats_enabled_mutex);
5514 
bpf_stats_release(struct inode * inode,struct file * file)5515 static int bpf_stats_release(struct inode *inode, struct file *file)
5516 {
5517 	mutex_lock(&bpf_stats_enabled_mutex);
5518 	static_key_slow_dec(&bpf_stats_enabled_key.key);
5519 	mutex_unlock(&bpf_stats_enabled_mutex);
5520 	return 0;
5521 }
5522 
5523 static const struct file_operations bpf_stats_fops = {
5524 	.release = bpf_stats_release,
5525 };
5526 
bpf_enable_runtime_stats(void)5527 static int bpf_enable_runtime_stats(void)
5528 {
5529 	int fd;
5530 
5531 	mutex_lock(&bpf_stats_enabled_mutex);
5532 
5533 	/* Set a very high limit to avoid overflow */
5534 	if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
5535 		mutex_unlock(&bpf_stats_enabled_mutex);
5536 		return -EBUSY;
5537 	}
5538 
5539 	fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
5540 	if (fd >= 0)
5541 		static_key_slow_inc(&bpf_stats_enabled_key.key);
5542 
5543 	mutex_unlock(&bpf_stats_enabled_mutex);
5544 	return fd;
5545 }
5546 
5547 #define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
5548 
bpf_enable_stats(union bpf_attr * attr)5549 static int bpf_enable_stats(union bpf_attr *attr)
5550 {
5551 
5552 	if (CHECK_ATTR(BPF_ENABLE_STATS))
5553 		return -EINVAL;
5554 
5555 	if (!capable(CAP_SYS_ADMIN))
5556 		return -EPERM;
5557 
5558 	switch (attr->enable_stats.type) {
5559 	case BPF_STATS_RUN_TIME:
5560 		return bpf_enable_runtime_stats();
5561 	default:
5562 		break;
5563 	}
5564 	return -EINVAL;
5565 }
5566 
5567 #define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
5568 
bpf_iter_create(union bpf_attr * attr)5569 static int bpf_iter_create(union bpf_attr *attr)
5570 {
5571 	struct bpf_link *link;
5572 	int err;
5573 
5574 	if (CHECK_ATTR(BPF_ITER_CREATE))
5575 		return -EINVAL;
5576 
5577 	if (attr->iter_create.flags)
5578 		return -EINVAL;
5579 
5580 	link = bpf_link_get_from_fd(attr->iter_create.link_fd);
5581 	if (IS_ERR(link))
5582 		return PTR_ERR(link);
5583 
5584 	err = bpf_iter_new_fd(link);
5585 	bpf_link_put_direct(link);
5586 
5587 	return err;
5588 }
5589 
5590 #define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
5591 
bpf_prog_bind_map(union bpf_attr * attr)5592 static int bpf_prog_bind_map(union bpf_attr *attr)
5593 {
5594 	struct bpf_prog *prog;
5595 	struct bpf_map *map;
5596 	struct bpf_map **used_maps_old, **used_maps_new;
5597 	int i, ret = 0;
5598 
5599 	if (CHECK_ATTR(BPF_PROG_BIND_MAP))
5600 		return -EINVAL;
5601 
5602 	if (attr->prog_bind_map.flags)
5603 		return -EINVAL;
5604 
5605 	prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
5606 	if (IS_ERR(prog))
5607 		return PTR_ERR(prog);
5608 
5609 	map = bpf_map_get(attr->prog_bind_map.map_fd);
5610 	if (IS_ERR(map)) {
5611 		ret = PTR_ERR(map);
5612 		goto out_prog_put;
5613 	}
5614 
5615 	mutex_lock(&prog->aux->used_maps_mutex);
5616 
5617 	used_maps_old = prog->aux->used_maps;
5618 
5619 	for (i = 0; i < prog->aux->used_map_cnt; i++)
5620 		if (used_maps_old[i] == map) {
5621 			bpf_map_put(map);
5622 			goto out_unlock;
5623 		}
5624 
5625 	used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
5626 				      sizeof(used_maps_new[0]),
5627 				      GFP_KERNEL);
5628 	if (!used_maps_new) {
5629 		ret = -ENOMEM;
5630 		goto out_unlock;
5631 	}
5632 
5633 	/* The bpf program will not access the bpf map, but for the sake of
5634 	 * simplicity, increase sleepable_refcnt for sleepable program as well.
5635 	 */
5636 	if (prog->sleepable)
5637 		atomic64_inc(&map->sleepable_refcnt);
5638 	memcpy(used_maps_new, used_maps_old,
5639 	       sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
5640 	used_maps_new[prog->aux->used_map_cnt] = map;
5641 
5642 	prog->aux->used_map_cnt++;
5643 	prog->aux->used_maps = used_maps_new;
5644 
5645 	kfree(used_maps_old);
5646 
5647 out_unlock:
5648 	mutex_unlock(&prog->aux->used_maps_mutex);
5649 
5650 	if (ret)
5651 		bpf_map_put(map);
5652 out_prog_put:
5653 	bpf_prog_put(prog);
5654 	return ret;
5655 }
5656 
5657 #define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
5658 
token_create(union bpf_attr * attr)5659 static int token_create(union bpf_attr *attr)
5660 {
5661 	if (CHECK_ATTR(BPF_TOKEN_CREATE))
5662 		return -EINVAL;
5663 
5664 	/* no flags are supported yet */
5665 	if (attr->token_create.flags)
5666 		return -EINVAL;
5667 
5668 	return bpf_token_create(attr);
5669 }
5670 
__sys_bpf(int cmd,bpfptr_t uattr,unsigned int size)5671 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
5672 {
5673 	union bpf_attr attr;
5674 	int err;
5675 
5676 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
5677 	if (err)
5678 		return err;
5679 	size = min_t(u32, size, sizeof(attr));
5680 
5681 	/* copy attributes from user space, may be less than sizeof(bpf_attr) */
5682 	memset(&attr, 0, sizeof(attr));
5683 	if (copy_from_bpfptr(&attr, uattr, size) != 0)
5684 		return -EFAULT;
5685 
5686 	err = security_bpf(cmd, &attr, size);
5687 	if (err < 0)
5688 		return err;
5689 
5690 	switch (cmd) {
5691 	case BPF_MAP_CREATE:
5692 		err = map_create(&attr);
5693 		break;
5694 	case BPF_MAP_LOOKUP_ELEM:
5695 		err = map_lookup_elem(&attr);
5696 		break;
5697 	case BPF_MAP_UPDATE_ELEM:
5698 		err = map_update_elem(&attr, uattr);
5699 		break;
5700 	case BPF_MAP_DELETE_ELEM:
5701 		err = map_delete_elem(&attr, uattr);
5702 		break;
5703 	case BPF_MAP_GET_NEXT_KEY:
5704 		err = map_get_next_key(&attr);
5705 		break;
5706 	case BPF_MAP_FREEZE:
5707 		err = map_freeze(&attr);
5708 		break;
5709 	case BPF_PROG_LOAD:
5710 		err = bpf_prog_load(&attr, uattr, size);
5711 		break;
5712 	case BPF_OBJ_PIN:
5713 		err = bpf_obj_pin(&attr);
5714 		break;
5715 	case BPF_OBJ_GET:
5716 		err = bpf_obj_get(&attr);
5717 		break;
5718 	case BPF_PROG_ATTACH:
5719 		err = bpf_prog_attach(&attr);
5720 		break;
5721 	case BPF_PROG_DETACH:
5722 		err = bpf_prog_detach(&attr);
5723 		break;
5724 	case BPF_PROG_QUERY:
5725 		err = bpf_prog_query(&attr, uattr.user);
5726 		break;
5727 	case BPF_PROG_TEST_RUN:
5728 		err = bpf_prog_test_run(&attr, uattr.user);
5729 		break;
5730 	case BPF_PROG_GET_NEXT_ID:
5731 		err = bpf_obj_get_next_id(&attr, uattr.user,
5732 					  &prog_idr, &prog_idr_lock);
5733 		break;
5734 	case BPF_MAP_GET_NEXT_ID:
5735 		err = bpf_obj_get_next_id(&attr, uattr.user,
5736 					  &map_idr, &map_idr_lock);
5737 		break;
5738 	case BPF_BTF_GET_NEXT_ID:
5739 		err = bpf_obj_get_next_id(&attr, uattr.user,
5740 					  &btf_idr, &btf_idr_lock);
5741 		break;
5742 	case BPF_PROG_GET_FD_BY_ID:
5743 		err = bpf_prog_get_fd_by_id(&attr);
5744 		break;
5745 	case BPF_MAP_GET_FD_BY_ID:
5746 		err = bpf_map_get_fd_by_id(&attr);
5747 		break;
5748 	case BPF_OBJ_GET_INFO_BY_FD:
5749 		err = bpf_obj_get_info_by_fd(&attr, uattr.user);
5750 		break;
5751 	case BPF_RAW_TRACEPOINT_OPEN:
5752 		err = bpf_raw_tracepoint_open(&attr);
5753 		break;
5754 	case BPF_BTF_LOAD:
5755 		err = bpf_btf_load(&attr, uattr, size);
5756 		break;
5757 	case BPF_BTF_GET_FD_BY_ID:
5758 		err = bpf_btf_get_fd_by_id(&attr);
5759 		break;
5760 	case BPF_TASK_FD_QUERY:
5761 		err = bpf_task_fd_query(&attr, uattr.user);
5762 		break;
5763 	case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
5764 		err = map_lookup_and_delete_elem(&attr);
5765 		break;
5766 	case BPF_MAP_LOOKUP_BATCH:
5767 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
5768 		break;
5769 	case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
5770 		err = bpf_map_do_batch(&attr, uattr.user,
5771 				       BPF_MAP_LOOKUP_AND_DELETE_BATCH);
5772 		break;
5773 	case BPF_MAP_UPDATE_BATCH:
5774 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
5775 		break;
5776 	case BPF_MAP_DELETE_BATCH:
5777 		err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
5778 		break;
5779 	case BPF_LINK_CREATE:
5780 		err = link_create(&attr, uattr);
5781 		break;
5782 	case BPF_LINK_UPDATE:
5783 		err = link_update(&attr);
5784 		break;
5785 	case BPF_LINK_GET_FD_BY_ID:
5786 		err = bpf_link_get_fd_by_id(&attr);
5787 		break;
5788 	case BPF_LINK_GET_NEXT_ID:
5789 		err = bpf_obj_get_next_id(&attr, uattr.user,
5790 					  &link_idr, &link_idr_lock);
5791 		break;
5792 	case BPF_ENABLE_STATS:
5793 		err = bpf_enable_stats(&attr);
5794 		break;
5795 	case BPF_ITER_CREATE:
5796 		err = bpf_iter_create(&attr);
5797 		break;
5798 	case BPF_LINK_DETACH:
5799 		err = link_detach(&attr);
5800 		break;
5801 	case BPF_PROG_BIND_MAP:
5802 		err = bpf_prog_bind_map(&attr);
5803 		break;
5804 	case BPF_TOKEN_CREATE:
5805 		err = token_create(&attr);
5806 		break;
5807 	default:
5808 		err = -EINVAL;
5809 		break;
5810 	}
5811 
5812 	return err;
5813 }
5814 
SYSCALL_DEFINE3(bpf,int,cmd,union bpf_attr __user *,uattr,unsigned int,size)5815 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
5816 {
5817 	return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
5818 }
5819 
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)5820 static bool syscall_prog_is_valid_access(int off, int size,
5821 					 enum bpf_access_type type,
5822 					 const struct bpf_prog *prog,
5823 					 struct bpf_insn_access_aux *info)
5824 {
5825 	if (off < 0 || off >= U16_MAX)
5826 		return false;
5827 	if (off % size != 0)
5828 		return false;
5829 	return true;
5830 }
5831 
BPF_CALL_3(bpf_sys_bpf,int,cmd,union bpf_attr *,attr,u32,attr_size)5832 BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
5833 {
5834 	switch (cmd) {
5835 	case BPF_MAP_CREATE:
5836 	case BPF_MAP_DELETE_ELEM:
5837 	case BPF_MAP_UPDATE_ELEM:
5838 	case BPF_MAP_FREEZE:
5839 	case BPF_MAP_GET_FD_BY_ID:
5840 	case BPF_PROG_LOAD:
5841 	case BPF_BTF_LOAD:
5842 	case BPF_LINK_CREATE:
5843 	case BPF_RAW_TRACEPOINT_OPEN:
5844 		break;
5845 	default:
5846 		return -EINVAL;
5847 	}
5848 	return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
5849 }
5850 
5851 
5852 /* To shut up -Wmissing-prototypes.
5853  * This function is used by the kernel light skeleton
5854  * to load bpf programs when modules are loaded or during kernel boot.
5855  * See tools/lib/bpf/skel_internal.h
5856  */
5857 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
5858 
kern_sys_bpf(int cmd,union bpf_attr * attr,unsigned int size)5859 int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
5860 {
5861 	struct bpf_prog * __maybe_unused prog;
5862 	struct bpf_tramp_run_ctx __maybe_unused run_ctx;
5863 
5864 	switch (cmd) {
5865 #ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
5866 	case BPF_PROG_TEST_RUN:
5867 		if (attr->test.data_in || attr->test.data_out ||
5868 		    attr->test.ctx_out || attr->test.duration ||
5869 		    attr->test.repeat || attr->test.flags)
5870 			return -EINVAL;
5871 
5872 		prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
5873 		if (IS_ERR(prog))
5874 			return PTR_ERR(prog);
5875 
5876 		if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
5877 		    attr->test.ctx_size_in > U16_MAX) {
5878 			bpf_prog_put(prog);
5879 			return -EINVAL;
5880 		}
5881 
5882 		run_ctx.bpf_cookie = 0;
5883 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
5884 			/* recursion detected */
5885 			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
5886 			bpf_prog_put(prog);
5887 			return -EBUSY;
5888 		}
5889 		attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
5890 		__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
5891 						&run_ctx);
5892 		bpf_prog_put(prog);
5893 		return 0;
5894 #endif
5895 	default:
5896 		return ____bpf_sys_bpf(cmd, attr, size);
5897 	}
5898 }
5899 EXPORT_SYMBOL(kern_sys_bpf);
5900 
5901 static const struct bpf_func_proto bpf_sys_bpf_proto = {
5902 	.func		= bpf_sys_bpf,
5903 	.gpl_only	= false,
5904 	.ret_type	= RET_INTEGER,
5905 	.arg1_type	= ARG_ANYTHING,
5906 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
5907 	.arg3_type	= ARG_CONST_SIZE,
5908 };
5909 
5910 const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5911 tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5912 {
5913 	return bpf_base_func_proto(func_id, prog);
5914 }
5915 
BPF_CALL_1(bpf_sys_close,u32,fd)5916 BPF_CALL_1(bpf_sys_close, u32, fd)
5917 {
5918 	/* When bpf program calls this helper there should not be
5919 	 * an fdget() without matching completed fdput().
5920 	 * This helper is allowed in the following callchain only:
5921 	 * sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
5922 	 */
5923 	return close_fd(fd);
5924 }
5925 
5926 static const struct bpf_func_proto bpf_sys_close_proto = {
5927 	.func		= bpf_sys_close,
5928 	.gpl_only	= false,
5929 	.ret_type	= RET_INTEGER,
5930 	.arg1_type	= ARG_ANYTHING,
5931 };
5932 
BPF_CALL_4(bpf_kallsyms_lookup_name,const char *,name,int,name_sz,int,flags,u64 *,res)5933 BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
5934 {
5935 	if (flags)
5936 		return -EINVAL;
5937 
5938 	if (name_sz <= 1 || name[name_sz - 1])
5939 		return -EINVAL;
5940 
5941 	if (!bpf_dump_raw_ok(current_cred()))
5942 		return -EPERM;
5943 
5944 	*res = kallsyms_lookup_name(name);
5945 	return *res ? 0 : -ENOENT;
5946 }
5947 
5948 static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
5949 	.func		= bpf_kallsyms_lookup_name,
5950 	.gpl_only	= false,
5951 	.ret_type	= RET_INTEGER,
5952 	.arg1_type	= ARG_PTR_TO_MEM,
5953 	.arg2_type	= ARG_CONST_SIZE_OR_ZERO,
5954 	.arg3_type	= ARG_ANYTHING,
5955 	.arg4_type	= ARG_PTR_TO_LONG,
5956 };
5957 
5958 static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id,const struct bpf_prog * prog)5959 syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
5960 {
5961 	switch (func_id) {
5962 	case BPF_FUNC_sys_bpf:
5963 		return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
5964 		       ? NULL : &bpf_sys_bpf_proto;
5965 	case BPF_FUNC_btf_find_by_name_kind:
5966 		return &bpf_btf_find_by_name_kind_proto;
5967 	case BPF_FUNC_sys_close:
5968 		return &bpf_sys_close_proto;
5969 	case BPF_FUNC_kallsyms_lookup_name:
5970 		return &bpf_kallsyms_lookup_name_proto;
5971 	default:
5972 		return tracing_prog_func_proto(func_id, prog);
5973 	}
5974 }
5975 
5976 const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
5977 	.get_func_proto  = syscall_prog_func_proto,
5978 	.is_valid_access = syscall_prog_is_valid_access,
5979 };
5980 
5981 const struct bpf_prog_ops bpf_syscall_prog_ops = {
5982 	.test_run = bpf_prog_test_run_syscall,
5983 };
5984 
5985 #ifdef CONFIG_SYSCTL
bpf_stats_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)5986 static int bpf_stats_handler(const struct ctl_table *table, int write,
5987 			     void *buffer, size_t *lenp, loff_t *ppos)
5988 {
5989 	struct static_key *key = (struct static_key *)table->data;
5990 	static int saved_val;
5991 	int val, ret;
5992 	struct ctl_table tmp = {
5993 		.data   = &val,
5994 		.maxlen = sizeof(val),
5995 		.mode   = table->mode,
5996 		.extra1 = SYSCTL_ZERO,
5997 		.extra2 = SYSCTL_ONE,
5998 	};
5999 
6000 	if (write && !capable(CAP_SYS_ADMIN))
6001 		return -EPERM;
6002 
6003 	mutex_lock(&bpf_stats_enabled_mutex);
6004 	val = saved_val;
6005 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6006 	if (write && !ret && val != saved_val) {
6007 		if (val)
6008 			static_key_slow_inc(key);
6009 		else
6010 			static_key_slow_dec(key);
6011 		saved_val = val;
6012 	}
6013 	mutex_unlock(&bpf_stats_enabled_mutex);
6014 	return ret;
6015 }
6016 
unpriv_ebpf_notify(int new_state)6017 void __weak unpriv_ebpf_notify(int new_state)
6018 {
6019 }
6020 
bpf_unpriv_handler(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)6021 static int bpf_unpriv_handler(const struct ctl_table *table, int write,
6022 			      void *buffer, size_t *lenp, loff_t *ppos)
6023 {
6024 	int ret, unpriv_enable = *(int *)table->data;
6025 	bool locked_state = unpriv_enable == 1;
6026 	struct ctl_table tmp = *table;
6027 
6028 	if (write && !capable(CAP_SYS_ADMIN))
6029 		return -EPERM;
6030 
6031 	tmp.data = &unpriv_enable;
6032 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
6033 	if (write && !ret) {
6034 		if (locked_state && unpriv_enable != 1)
6035 			return -EPERM;
6036 		*(int *)table->data = unpriv_enable;
6037 	}
6038 
6039 	if (write)
6040 		unpriv_ebpf_notify(unpriv_enable);
6041 
6042 	return ret;
6043 }
6044 
6045 static struct ctl_table bpf_syscall_table[] = {
6046 	{
6047 		.procname	= "unprivileged_bpf_disabled",
6048 		.data		= &sysctl_unprivileged_bpf_disabled,
6049 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
6050 		.mode		= 0644,
6051 		.proc_handler	= bpf_unpriv_handler,
6052 		.extra1		= SYSCTL_ZERO,
6053 		.extra2		= SYSCTL_TWO,
6054 	},
6055 	{
6056 		.procname	= "bpf_stats_enabled",
6057 		.data		= &bpf_stats_enabled_key.key,
6058 		.mode		= 0644,
6059 		.proc_handler	= bpf_stats_handler,
6060 	},
6061 };
6062 
bpf_syscall_sysctl_init(void)6063 static int __init bpf_syscall_sysctl_init(void)
6064 {
6065 	register_sysctl_init("kernel", bpf_syscall_table);
6066 	return 0;
6067 }
6068 late_initcall(bpf_syscall_sysctl_init);
6069 #endif /* CONFIG_SYSCTL */
6070