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