1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
7 * This program is distributed in the hope that it will be useful, but
8 * WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10 * General Public License for more details.
12 #include <linux/bpf.h>
13 #include <linux/bpf_trace.h>
14 #include <linux/syscalls.h>
15 #include <linux/slab.h>
16 #include <linux/sched/signal.h>
17 #include <linux/vmalloc.h>
18 #include <linux/mmzone.h>
19 #include <linux/anon_inodes.h>
20 #include <linux/file.h>
21 #include <linux/license.h>
22 #include <linux/filter.h>
23 #include <linux/version.h>
24 #include <linux/kernel.h>
25 #include <linux/idr.h>
26 #include <linux/cred.h>
27 #include <linux/timekeeping.h>
28 #include <linux/ctype.h>
30 #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
31 (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
32 (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
33 (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
34 #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
35 #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map))
37 #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY)
39 DEFINE_PER_CPU(int, bpf_prog_active);
40 static DEFINE_IDR(prog_idr);
41 static DEFINE_SPINLOCK(prog_idr_lock);
42 static DEFINE_IDR(map_idr);
43 static DEFINE_SPINLOCK(map_idr_lock);
45 int sysctl_unprivileged_bpf_disabled __read_mostly;
47 static const struct bpf_map_ops * const bpf_map_types[] = {
48 #define BPF_PROG_TYPE(_id, _ops)
49 #define BPF_MAP_TYPE(_id, _ops) \
51 #include <linux/bpf_types.h>
57 * If we're handed a bigger struct than we know of, ensure all the unknown bits
58 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
59 * we don't know about yet.
61 * There is a ToCToU between this function call and the following
62 * copy_from_user() call. However, this is not a concern since this function is
63 * meant to be a future-proofing of bits.
65 static int check_uarg_tail_zero(void __user *uaddr,
69 unsigned char __user *addr;
70 unsigned char __user *end;
74 if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
77 if (unlikely(!access_ok(VERIFY_READ, uaddr, actual_size)))
80 if (actual_size <= expected_size)
83 addr = uaddr + expected_size;
84 end = uaddr + actual_size;
86 for (; addr < end; addr++) {
87 err = get_user(val, addr);
97 const struct bpf_map_ops bpf_map_offload_ops = {
98 .map_alloc = bpf_map_offload_map_alloc,
99 .map_free = bpf_map_offload_map_free,
102 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
104 const struct bpf_map_ops *ops;
108 if (attr->map_type >= ARRAY_SIZE(bpf_map_types))
109 return ERR_PTR(-EINVAL);
110 ops = bpf_map_types[attr->map_type];
112 return ERR_PTR(-EINVAL);
114 if (ops->map_alloc_check) {
115 err = ops->map_alloc_check(attr);
119 if (attr->map_ifindex)
120 ops = &bpf_map_offload_ops;
121 map = ops->map_alloc(attr);
125 map->map_type = attr->map_type;
129 void *bpf_map_area_alloc(size_t size, int numa_node)
131 /* We definitely need __GFP_NORETRY, so OOM killer doesn't
132 * trigger under memory pressure as we really just want to
135 const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
138 if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
139 area = kmalloc_node(size, GFP_USER | flags, numa_node);
144 return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
145 __builtin_return_address(0));
148 void bpf_map_area_free(void *area)
153 void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
155 map->map_type = attr->map_type;
156 map->key_size = attr->key_size;
157 map->value_size = attr->value_size;
158 map->max_entries = attr->max_entries;
159 map->map_flags = attr->map_flags;
160 map->numa_node = bpf_map_attr_numa_node(attr);
163 int bpf_map_precharge_memlock(u32 pages)
165 struct user_struct *user = get_current_user();
166 unsigned long memlock_limit, cur;
168 memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
169 cur = atomic_long_read(&user->locked_vm);
171 if (cur + pages > memlock_limit)
176 static int bpf_map_charge_memlock(struct bpf_map *map)
178 struct user_struct *user = get_current_user();
179 unsigned long memlock_limit;
181 memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
183 atomic_long_add(map->pages, &user->locked_vm);
185 if (atomic_long_read(&user->locked_vm) > memlock_limit) {
186 atomic_long_sub(map->pages, &user->locked_vm);
194 static void bpf_map_uncharge_memlock(struct bpf_map *map)
196 struct user_struct *user = map->user;
198 atomic_long_sub(map->pages, &user->locked_vm);
202 static int bpf_map_alloc_id(struct bpf_map *map)
206 spin_lock_bh(&map_idr_lock);
207 id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
210 spin_unlock_bh(&map_idr_lock);
212 if (WARN_ON_ONCE(!id))
215 return id > 0 ? 0 : id;
218 void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
222 /* Offloaded maps are removed from the IDR store when their device
223 * disappears - even if someone holds an fd to them they are unusable,
224 * the memory is gone, all ops will fail; they are simply waiting for
225 * refcnt to drop to be freed.
231 spin_lock_irqsave(&map_idr_lock, flags);
233 __acquire(&map_idr_lock);
235 idr_remove(&map_idr, map->id);
239 spin_unlock_irqrestore(&map_idr_lock, flags);
241 __release(&map_idr_lock);
244 /* called from workqueue */
245 static void bpf_map_free_deferred(struct work_struct *work)
247 struct bpf_map *map = container_of(work, struct bpf_map, work);
249 bpf_map_uncharge_memlock(map);
250 security_bpf_map_free(map);
251 /* implementation dependent freeing */
252 map->ops->map_free(map);
255 static void bpf_map_put_uref(struct bpf_map *map)
257 if (atomic_dec_and_test(&map->usercnt)) {
258 if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
259 bpf_fd_array_map_clear(map);
263 /* decrement map refcnt and schedule it for freeing via workqueue
264 * (unrelying map implementation ops->map_free() might sleep)
266 static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
268 if (atomic_dec_and_test(&map->refcnt)) {
269 /* bpf_map_free_id() must be called first */
270 bpf_map_free_id(map, do_idr_lock);
271 INIT_WORK(&map->work, bpf_map_free_deferred);
272 schedule_work(&map->work);
276 void bpf_map_put(struct bpf_map *map)
278 __bpf_map_put(map, true);
281 void bpf_map_put_with_uref(struct bpf_map *map)
283 bpf_map_put_uref(map);
287 static int bpf_map_release(struct inode *inode, struct file *filp)
289 struct bpf_map *map = filp->private_data;
291 if (map->ops->map_release)
292 map->ops->map_release(map, filp);
294 bpf_map_put_with_uref(map);
298 #ifdef CONFIG_PROC_FS
299 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
301 const struct bpf_map *map = filp->private_data;
302 const struct bpf_array *array;
303 u32 owner_prog_type = 0;
306 if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
307 array = container_of(map, struct bpf_array, map);
308 owner_prog_type = array->owner_prog_type;
309 owner_jited = array->owner_jited;
324 map->pages * 1ULL << PAGE_SHIFT);
326 if (owner_prog_type) {
327 seq_printf(m, "owner_prog_type:\t%u\n",
329 seq_printf(m, "owner_jited:\t%u\n",
335 static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
338 /* We need this handler such that alloc_file() enables
339 * f_mode with FMODE_CAN_READ.
344 static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
345 size_t siz, loff_t *ppos)
347 /* We need this handler such that alloc_file() enables
348 * f_mode with FMODE_CAN_WRITE.
353 const struct file_operations bpf_map_fops = {
354 #ifdef CONFIG_PROC_FS
355 .show_fdinfo = bpf_map_show_fdinfo,
357 .release = bpf_map_release,
358 .read = bpf_dummy_read,
359 .write = bpf_dummy_write,
362 int bpf_map_new_fd(struct bpf_map *map, int flags)
366 ret = security_bpf_map(map, OPEN_FMODE(flags));
370 return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
374 int bpf_get_file_flag(int flags)
376 if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
378 if (flags & BPF_F_RDONLY)
380 if (flags & BPF_F_WRONLY)
385 /* helper macro to check that unused fields 'union bpf_attr' are zero */
386 #define CHECK_ATTR(CMD) \
387 memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
388 sizeof(attr->CMD##_LAST_FIELD), 0, \
390 offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
391 sizeof(attr->CMD##_LAST_FIELD)) != NULL
393 /* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes.
394 * Return 0 on success and < 0 on error.
396 static int bpf_obj_name_cpy(char *dst, const char *src)
398 const char *end = src + BPF_OBJ_NAME_LEN;
400 memset(dst, 0, BPF_OBJ_NAME_LEN);
402 /* Copy all isalnum() and '_' char */
403 while (src < end && *src) {
404 if (!isalnum(*src) && *src != '_')
409 /* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */
416 #define BPF_MAP_CREATE_LAST_FIELD map_ifindex
417 /* called via syscall */
418 static int map_create(union bpf_attr *attr)
420 int numa_node = bpf_map_attr_numa_node(attr);
425 err = CHECK_ATTR(BPF_MAP_CREATE);
429 f_flags = bpf_get_file_flag(attr->map_flags);
433 if (numa_node != NUMA_NO_NODE &&
434 ((unsigned int)numa_node >= nr_node_ids ||
435 !node_online(numa_node)))
438 /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
439 map = find_and_alloc_map(attr);
443 err = bpf_obj_name_cpy(map->name, attr->map_name);
445 goto free_map_nouncharge;
447 atomic_set(&map->refcnt, 1);
448 atomic_set(&map->usercnt, 1);
450 err = security_bpf_map_alloc(map);
452 goto free_map_nouncharge;
454 err = bpf_map_charge_memlock(map);
458 err = bpf_map_alloc_id(map);
462 err = bpf_map_new_fd(map, f_flags);
464 /* failed to allocate fd.
465 * bpf_map_put() is needed because the above
466 * bpf_map_alloc_id() has published the map
467 * to the userspace and the userspace may
468 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
474 trace_bpf_map_create(map, err);
478 bpf_map_uncharge_memlock(map);
480 security_bpf_map_free(map);
482 map->ops->map_free(map);
486 /* if error is returned, fd is released.
487 * On success caller should complete fd access with matching fdput()
489 struct bpf_map *__bpf_map_get(struct fd f)
492 return ERR_PTR(-EBADF);
493 if (f.file->f_op != &bpf_map_fops) {
495 return ERR_PTR(-EINVAL);
498 return f.file->private_data;
501 /* prog's and map's refcnt limit */
502 #define BPF_MAX_REFCNT 32768
504 struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
506 if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
507 atomic_dec(&map->refcnt);
508 return ERR_PTR(-EBUSY);
511 atomic_inc(&map->usercnt);
515 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
517 struct fd f = fdget(ufd);
520 map = __bpf_map_get(f);
524 map = bpf_map_inc(map, true);
530 /* map_idr_lock should have been held */
531 static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map,
536 refold = __atomic_add_unless(&map->refcnt, 1, 0);
538 if (refold >= BPF_MAX_REFCNT) {
539 __bpf_map_put(map, false);
540 return ERR_PTR(-EBUSY);
544 return ERR_PTR(-ENOENT);
547 atomic_inc(&map->usercnt);
552 int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
557 /* last field in 'union bpf_attr' used by this command */
558 #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
560 static int map_lookup_elem(union bpf_attr *attr)
562 void __user *ukey = u64_to_user_ptr(attr->key);
563 void __user *uvalue = u64_to_user_ptr(attr->value);
564 int ufd = attr->map_fd;
566 void *key, *value, *ptr;
571 if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
575 map = __bpf_map_get(f);
579 if (!(f.file->f_mode & FMODE_CAN_READ)) {
584 key = memdup_user(ukey, map->key_size);
590 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
591 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
592 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
593 value_size = round_up(map->value_size, 8) * num_possible_cpus();
594 else if (IS_FD_MAP(map))
595 value_size = sizeof(u32);
597 value_size = map->value_size;
600 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
604 if (bpf_map_is_dev_bound(map)) {
605 err = bpf_map_offload_lookup_elem(map, key, value);
606 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
607 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
608 err = bpf_percpu_hash_copy(map, key, value);
609 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
610 err = bpf_percpu_array_copy(map, key, value);
611 } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
612 err = bpf_stackmap_copy(map, key, value);
613 } else if (IS_FD_ARRAY(map)) {
614 err = bpf_fd_array_map_lookup_elem(map, key, value);
615 } else if (IS_FD_HASH(map)) {
616 err = bpf_fd_htab_map_lookup_elem(map, key, value);
619 ptr = map->ops->map_lookup_elem(map, key);
621 memcpy(value, ptr, value_size);
623 err = ptr ? 0 : -ENOENT;
630 if (copy_to_user(uvalue, value, value_size) != 0)
633 trace_bpf_map_lookup_elem(map, ufd, key, value);
645 #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
647 static int map_update_elem(union bpf_attr *attr)
649 void __user *ukey = u64_to_user_ptr(attr->key);
650 void __user *uvalue = u64_to_user_ptr(attr->value);
651 int ufd = attr->map_fd;
658 if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
662 map = __bpf_map_get(f);
666 if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
671 key = memdup_user(ukey, map->key_size);
677 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
678 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
679 map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
680 value_size = round_up(map->value_size, 8) * num_possible_cpus();
682 value_size = map->value_size;
685 value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
690 if (copy_from_user(value, uvalue, value_size) != 0)
693 /* Need to create a kthread, thus must support schedule */
694 if (bpf_map_is_dev_bound(map)) {
695 err = bpf_map_offload_update_elem(map, key, value, attr->flags);
697 } else if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
698 err = map->ops->map_update_elem(map, key, value, attr->flags);
702 /* must increment bpf_prog_active to avoid kprobe+bpf triggering from
703 * inside bpf map update or delete otherwise deadlocks are possible
706 __this_cpu_inc(bpf_prog_active);
707 if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
708 map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
709 err = bpf_percpu_hash_update(map, key, value, attr->flags);
710 } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
711 err = bpf_percpu_array_update(map, key, value, attr->flags);
712 } else if (map->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY ||
713 map->map_type == BPF_MAP_TYPE_PROG_ARRAY ||
714 map->map_type == BPF_MAP_TYPE_CGROUP_ARRAY ||
715 map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) {
717 err = bpf_fd_array_map_update_elem(map, f.file, key, value,
720 } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
722 err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
727 err = map->ops->map_update_elem(map, key, value, attr->flags);
730 __this_cpu_dec(bpf_prog_active);
734 trace_bpf_map_update_elem(map, ufd, key, value);
744 #define BPF_MAP_DELETE_ELEM_LAST_FIELD key
746 static int map_delete_elem(union bpf_attr *attr)
748 void __user *ukey = u64_to_user_ptr(attr->key);
749 int ufd = attr->map_fd;
755 if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
759 map = __bpf_map_get(f);
763 if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
768 key = memdup_user(ukey, map->key_size);
774 if (bpf_map_is_dev_bound(map)) {
775 err = bpf_map_offload_delete_elem(map, key);
780 __this_cpu_inc(bpf_prog_active);
782 err = map->ops->map_delete_elem(map, key);
784 __this_cpu_dec(bpf_prog_active);
788 trace_bpf_map_delete_elem(map, ufd, key);
795 /* last field in 'union bpf_attr' used by this command */
796 #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
798 static int map_get_next_key(union bpf_attr *attr)
800 void __user *ukey = u64_to_user_ptr(attr->key);
801 void __user *unext_key = u64_to_user_ptr(attr->next_key);
802 int ufd = attr->map_fd;
804 void *key, *next_key;
808 if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
812 map = __bpf_map_get(f);
816 if (!(f.file->f_mode & FMODE_CAN_READ)) {
822 key = memdup_user(ukey, map->key_size);
832 next_key = kmalloc(map->key_size, GFP_USER);
836 if (bpf_map_is_dev_bound(map)) {
837 err = bpf_map_offload_get_next_key(map, key, next_key);
842 err = map->ops->map_get_next_key(map, key, next_key);
849 if (copy_to_user(unext_key, next_key, map->key_size) != 0)
852 trace_bpf_map_next_key(map, ufd, key, next_key);
864 static const struct bpf_prog_ops * const bpf_prog_types[] = {
865 #define BPF_PROG_TYPE(_id, _name) \
866 [_id] = & _name ## _prog_ops,
867 #define BPF_MAP_TYPE(_id, _ops)
868 #include <linux/bpf_types.h>
873 static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
875 if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
878 if (!bpf_prog_is_dev_bound(prog->aux))
879 prog->aux->ops = bpf_prog_types[type];
881 prog->aux->ops = &bpf_offload_prog_ops;
886 /* drop refcnt on maps used by eBPF program and free auxilary data */
887 static void free_used_maps(struct bpf_prog_aux *aux)
891 for (i = 0; i < aux->used_map_cnt; i++)
892 bpf_map_put(aux->used_maps[i]);
894 kfree(aux->used_maps);
897 int __bpf_prog_charge(struct user_struct *user, u32 pages)
899 unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
900 unsigned long user_bufs;
903 user_bufs = atomic_long_add_return(pages, &user->locked_vm);
904 if (user_bufs > memlock_limit) {
905 atomic_long_sub(pages, &user->locked_vm);
913 void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
916 atomic_long_sub(pages, &user->locked_vm);
919 static int bpf_prog_charge_memlock(struct bpf_prog *prog)
921 struct user_struct *user = get_current_user();
924 ret = __bpf_prog_charge(user, prog->pages);
930 prog->aux->user = user;
934 static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
936 struct user_struct *user = prog->aux->user;
938 __bpf_prog_uncharge(user, prog->pages);
942 static int bpf_prog_alloc_id(struct bpf_prog *prog)
946 spin_lock_bh(&prog_idr_lock);
947 id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
950 spin_unlock_bh(&prog_idr_lock);
952 /* id is in [1, INT_MAX) */
953 if (WARN_ON_ONCE(!id))
956 return id > 0 ? 0 : id;
959 void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
961 /* cBPF to eBPF migrations are currently not in the idr store.
962 * Offloaded programs are removed from the store when their device
963 * disappears - even if someone grabs an fd to them they are unusable,
964 * simply waiting for refcnt to drop to be freed.
970 spin_lock_bh(&prog_idr_lock);
972 __acquire(&prog_idr_lock);
974 idr_remove(&prog_idr, prog->aux->id);
978 spin_unlock_bh(&prog_idr_lock);
980 __release(&prog_idr_lock);
983 static void __bpf_prog_put_rcu(struct rcu_head *rcu)
985 struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
988 bpf_prog_uncharge_memlock(aux->prog);
989 security_bpf_prog_free(aux);
990 bpf_prog_free(aux->prog);
993 static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
995 if (atomic_dec_and_test(&prog->aux->refcnt)) {
998 trace_bpf_prog_put_rcu(prog);
999 /* bpf_prog_free_id() must be called first */
1000 bpf_prog_free_id(prog, do_idr_lock);
1002 for (i = 0; i < prog->aux->func_cnt; i++)
1003 bpf_prog_kallsyms_del(prog->aux->func[i]);
1004 bpf_prog_kallsyms_del(prog);
1006 call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
1010 void bpf_prog_put(struct bpf_prog *prog)
1012 __bpf_prog_put(prog, true);
1014 EXPORT_SYMBOL_GPL(bpf_prog_put);
1016 static int bpf_prog_release(struct inode *inode, struct file *filp)
1018 struct bpf_prog *prog = filp->private_data;
1024 #ifdef CONFIG_PROC_FS
1025 static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
1027 const struct bpf_prog *prog = filp->private_data;
1028 char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
1030 bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
1039 prog->pages * 1ULL << PAGE_SHIFT);
1043 const struct file_operations bpf_prog_fops = {
1044 #ifdef CONFIG_PROC_FS
1045 .show_fdinfo = bpf_prog_show_fdinfo,
1047 .release = bpf_prog_release,
1048 .read = bpf_dummy_read,
1049 .write = bpf_dummy_write,
1052 int bpf_prog_new_fd(struct bpf_prog *prog)
1056 ret = security_bpf_prog(prog);
1060 return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
1061 O_RDWR | O_CLOEXEC);
1064 static struct bpf_prog *____bpf_prog_get(struct fd f)
1067 return ERR_PTR(-EBADF);
1068 if (f.file->f_op != &bpf_prog_fops) {
1070 return ERR_PTR(-EINVAL);
1073 return f.file->private_data;
1076 struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
1078 if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
1079 atomic_sub(i, &prog->aux->refcnt);
1080 return ERR_PTR(-EBUSY);
1084 EXPORT_SYMBOL_GPL(bpf_prog_add);
1086 void bpf_prog_sub(struct bpf_prog *prog, int i)
1088 /* Only to be used for undoing previous bpf_prog_add() in some
1089 * error path. We still know that another entity in our call
1090 * path holds a reference to the program, thus atomic_sub() can
1091 * be safely used in such cases!
1093 WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
1095 EXPORT_SYMBOL_GPL(bpf_prog_sub);
1097 struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
1099 return bpf_prog_add(prog, 1);
1101 EXPORT_SYMBOL_GPL(bpf_prog_inc);
1103 /* prog_idr_lock should have been held */
1104 struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
1108 refold = __atomic_add_unless(&prog->aux->refcnt, 1, 0);
1110 if (refold >= BPF_MAX_REFCNT) {
1111 __bpf_prog_put(prog, false);
1112 return ERR_PTR(-EBUSY);
1116 return ERR_PTR(-ENOENT);
1120 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
1122 bool bpf_prog_get_ok(struct bpf_prog *prog,
1123 enum bpf_prog_type *attach_type, bool attach_drv)
1125 /* not an attachment, just a refcount inc, always allow */
1129 if (prog->type != *attach_type)
1131 if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
1137 static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
1140 struct fd f = fdget(ufd);
1141 struct bpf_prog *prog;
1143 prog = ____bpf_prog_get(f);
1146 if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
1147 prog = ERR_PTR(-EINVAL);
1151 prog = bpf_prog_inc(prog);
1157 struct bpf_prog *bpf_prog_get(u32 ufd)
1159 return __bpf_prog_get(ufd, NULL, false);
1162 struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
1165 struct bpf_prog *prog = __bpf_prog_get(ufd, &type, attach_drv);
1168 trace_bpf_prog_get_type(prog);
1171 EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
1173 /* last field in 'union bpf_attr' used by this command */
1174 #define BPF_PROG_LOAD_LAST_FIELD prog_ifindex
1176 static int bpf_prog_load(union bpf_attr *attr)
1178 enum bpf_prog_type type = attr->prog_type;
1179 struct bpf_prog *prog;
1184 if (CHECK_ATTR(BPF_PROG_LOAD))
1187 if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
1190 /* copy eBPF program license from user space */
1191 if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
1192 sizeof(license) - 1) < 0)
1194 license[sizeof(license) - 1] = 0;
1196 /* eBPF programs must be GPL compatible to use GPL-ed functions */
1197 is_gpl = license_is_gpl_compatible(license);
1199 if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
1202 if (type == BPF_PROG_TYPE_KPROBE &&
1203 attr->kern_version != LINUX_VERSION_CODE)
1206 if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
1207 type != BPF_PROG_TYPE_CGROUP_SKB &&
1208 !capable(CAP_SYS_ADMIN))
1211 /* plain bpf_prog allocation */
1212 prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
1216 prog->aux->offload_requested = !!attr->prog_ifindex;
1218 err = security_bpf_prog_alloc(prog->aux);
1220 goto free_prog_nouncharge;
1222 err = bpf_prog_charge_memlock(prog);
1226 prog->len = attr->insn_cnt;
1229 if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
1230 bpf_prog_insn_size(prog)) != 0)
1233 prog->orig_prog = NULL;
1236 atomic_set(&prog->aux->refcnt, 1);
1237 prog->gpl_compatible = is_gpl ? 1 : 0;
1239 if (bpf_prog_is_dev_bound(prog->aux)) {
1240 err = bpf_prog_offload_init(prog, attr);
1245 /* find program type: socket_filter vs tracing_filter */
1246 err = find_prog_type(type, prog);
1250 prog->aux->load_time = ktime_get_boot_ns();
1251 err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name);
1255 /* run eBPF verifier */
1256 err = bpf_check(&prog, attr);
1258 goto free_used_maps;
1260 /* eBPF program is ready to be JITed */
1261 if (!prog->bpf_func)
1262 prog = bpf_prog_select_runtime(prog, &err);
1264 goto free_used_maps;
1266 err = bpf_prog_alloc_id(prog);
1268 goto free_used_maps;
1270 err = bpf_prog_new_fd(prog);
1272 /* failed to allocate fd.
1273 * bpf_prog_put() is needed because the above
1274 * bpf_prog_alloc_id() has published the prog
1275 * to the userspace and the userspace may
1276 * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
1282 bpf_prog_kallsyms_add(prog);
1283 trace_bpf_prog_load(prog, err);
1287 free_used_maps(prog->aux);
1289 bpf_prog_uncharge_memlock(prog);
1291 security_bpf_prog_free(prog->aux);
1292 free_prog_nouncharge:
1293 bpf_prog_free(prog);
1297 #define BPF_OBJ_LAST_FIELD file_flags
1299 static int bpf_obj_pin(const union bpf_attr *attr)
1301 if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
1304 return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
1307 static int bpf_obj_get(const union bpf_attr *attr)
1309 if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
1310 attr->file_flags & ~BPF_OBJ_FLAG_MASK)
1313 return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
1317 #ifdef CONFIG_CGROUP_BPF
1319 #define BPF_PROG_ATTACH_LAST_FIELD attach_flags
1321 static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach)
1323 struct bpf_prog *prog = NULL;
1324 int ufd = attr->target_fd;
1325 struct bpf_map *map;
1330 map = __bpf_map_get(f);
1332 return PTR_ERR(map);
1335 prog = bpf_prog_get_type(attr->attach_bpf_fd,
1336 BPF_PROG_TYPE_SK_SKB);
1339 return PTR_ERR(prog);
1343 err = sock_map_prog(map, prog, attr->attach_type);
1355 #define BPF_F_ATTACH_MASK \
1356 (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
1358 static int bpf_prog_attach(const union bpf_attr *attr)
1360 enum bpf_prog_type ptype;
1361 struct bpf_prog *prog;
1362 struct cgroup *cgrp;
1365 if (!capable(CAP_NET_ADMIN))
1368 if (CHECK_ATTR(BPF_PROG_ATTACH))
1371 if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
1374 switch (attr->attach_type) {
1375 case BPF_CGROUP_INET_INGRESS:
1376 case BPF_CGROUP_INET_EGRESS:
1377 ptype = BPF_PROG_TYPE_CGROUP_SKB;
1379 case BPF_CGROUP_INET_SOCK_CREATE:
1380 ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1382 case BPF_CGROUP_SOCK_OPS:
1383 ptype = BPF_PROG_TYPE_SOCK_OPS;
1385 case BPF_CGROUP_DEVICE:
1386 ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1388 case BPF_SK_SKB_STREAM_PARSER:
1389 case BPF_SK_SKB_STREAM_VERDICT:
1390 return sockmap_get_from_fd(attr, true);
1395 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1397 return PTR_ERR(prog);
1399 cgrp = cgroup_get_from_fd(attr->target_fd);
1402 return PTR_ERR(cgrp);
1405 ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type,
1406 attr->attach_flags);
1414 #define BPF_PROG_DETACH_LAST_FIELD attach_type
1416 static int bpf_prog_detach(const union bpf_attr *attr)
1418 enum bpf_prog_type ptype;
1419 struct bpf_prog *prog;
1420 struct cgroup *cgrp;
1423 if (!capable(CAP_NET_ADMIN))
1426 if (CHECK_ATTR(BPF_PROG_DETACH))
1429 switch (attr->attach_type) {
1430 case BPF_CGROUP_INET_INGRESS:
1431 case BPF_CGROUP_INET_EGRESS:
1432 ptype = BPF_PROG_TYPE_CGROUP_SKB;
1434 case BPF_CGROUP_INET_SOCK_CREATE:
1435 ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1437 case BPF_CGROUP_SOCK_OPS:
1438 ptype = BPF_PROG_TYPE_SOCK_OPS;
1440 case BPF_CGROUP_DEVICE:
1441 ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1443 case BPF_SK_SKB_STREAM_PARSER:
1444 case BPF_SK_SKB_STREAM_VERDICT:
1445 return sockmap_get_from_fd(attr, false);
1450 cgrp = cgroup_get_from_fd(attr->target_fd);
1452 return PTR_ERR(cgrp);
1454 prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1458 ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0);
1465 #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
1467 static int bpf_prog_query(const union bpf_attr *attr,
1468 union bpf_attr __user *uattr)
1470 struct cgroup *cgrp;
1473 if (!capable(CAP_NET_ADMIN))
1475 if (CHECK_ATTR(BPF_PROG_QUERY))
1477 if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
1480 switch (attr->query.attach_type) {
1481 case BPF_CGROUP_INET_INGRESS:
1482 case BPF_CGROUP_INET_EGRESS:
1483 case BPF_CGROUP_INET_SOCK_CREATE:
1484 case BPF_CGROUP_SOCK_OPS:
1485 case BPF_CGROUP_DEVICE:
1490 cgrp = cgroup_get_from_fd(attr->query.target_fd);
1492 return PTR_ERR(cgrp);
1493 ret = cgroup_bpf_query(cgrp, attr, uattr);
1497 #endif /* CONFIG_CGROUP_BPF */
1499 #define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
1501 static int bpf_prog_test_run(const union bpf_attr *attr,
1502 union bpf_attr __user *uattr)
1504 struct bpf_prog *prog;
1505 int ret = -ENOTSUPP;
1507 if (CHECK_ATTR(BPF_PROG_TEST_RUN))
1510 prog = bpf_prog_get(attr->test.prog_fd);
1512 return PTR_ERR(prog);
1514 if (prog->aux->ops->test_run)
1515 ret = prog->aux->ops->test_run(prog, attr, uattr);
1521 #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
1523 static int bpf_obj_get_next_id(const union bpf_attr *attr,
1524 union bpf_attr __user *uattr,
1528 u32 next_id = attr->start_id;
1531 if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
1534 if (!capable(CAP_SYS_ADMIN))
1539 if (!idr_get_next(idr, &next_id))
1541 spin_unlock_bh(lock);
1544 err = put_user(next_id, &uattr->next_id);
1549 #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
1551 static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
1553 struct bpf_prog *prog;
1554 u32 id = attr->prog_id;
1557 if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
1560 if (!capable(CAP_SYS_ADMIN))
1563 spin_lock_bh(&prog_idr_lock);
1564 prog = idr_find(&prog_idr, id);
1566 prog = bpf_prog_inc_not_zero(prog);
1568 prog = ERR_PTR(-ENOENT);
1569 spin_unlock_bh(&prog_idr_lock);
1572 return PTR_ERR(prog);
1574 fd = bpf_prog_new_fd(prog);
1581 #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
1583 static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
1585 struct bpf_map *map;
1586 u32 id = attr->map_id;
1590 if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
1591 attr->open_flags & ~BPF_OBJ_FLAG_MASK)
1594 if (!capable(CAP_SYS_ADMIN))
1597 f_flags = bpf_get_file_flag(attr->open_flags);
1601 spin_lock_bh(&map_idr_lock);
1602 map = idr_find(&map_idr, id);
1604 map = bpf_map_inc_not_zero(map, true);
1606 map = ERR_PTR(-ENOENT);
1607 spin_unlock_bh(&map_idr_lock);
1610 return PTR_ERR(map);
1612 fd = bpf_map_new_fd(map, f_flags);
1619 static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
1624 for (i = 0; i < prog->aux->used_map_cnt; i++)
1625 if (prog->aux->used_maps[i] == (void *)addr)
1626 return prog->aux->used_maps[i];
1630 static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
1632 const struct bpf_map *map;
1633 struct bpf_insn *insns;
1637 insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
1642 for (i = 0; i < prog->len; i++) {
1643 if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
1644 insns[i].code = BPF_JMP | BPF_CALL;
1645 insns[i].imm = BPF_FUNC_tail_call;
1648 if (insns[i].code == (BPF_JMP | BPF_CALL) ||
1649 insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
1650 if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
1651 insns[i].code = BPF_JMP | BPF_CALL;
1652 if (!bpf_dump_raw_ok())
1657 if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
1660 imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
1661 map = bpf_map_from_imm(prog, imm);
1663 insns[i].src_reg = BPF_PSEUDO_MAP_FD;
1664 insns[i].imm = map->id;
1665 insns[i + 1].imm = 0;
1669 if (!bpf_dump_raw_ok() &&
1670 imm == (unsigned long)prog->aux) {
1672 insns[i + 1].imm = 0;
1680 static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
1681 const union bpf_attr *attr,
1682 union bpf_attr __user *uattr)
1684 struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1685 struct bpf_prog_info info = {};
1686 u32 info_len = attr->info.info_len;
1687 char __user *uinsns;
1691 err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1694 info_len = min_t(u32, sizeof(info), info_len);
1696 if (copy_from_user(&info, uinfo, info_len))
1699 info.type = prog->type;
1700 info.id = prog->aux->id;
1701 info.load_time = prog->aux->load_time;
1702 info.created_by_uid = from_kuid_munged(current_user_ns(),
1703 prog->aux->user->uid);
1705 memcpy(info.tag, prog->tag, sizeof(prog->tag));
1706 memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
1708 ulen = info.nr_map_ids;
1709 info.nr_map_ids = prog->aux->used_map_cnt;
1710 ulen = min_t(u32, info.nr_map_ids, ulen);
1712 u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
1715 for (i = 0; i < ulen; i++)
1716 if (put_user(prog->aux->used_maps[i]->id,
1721 if (!capable(CAP_SYS_ADMIN)) {
1722 info.jited_prog_len = 0;
1723 info.xlated_prog_len = 0;
1727 ulen = info.jited_prog_len;
1728 info.jited_prog_len = prog->jited_len;
1729 if (info.jited_prog_len && ulen) {
1730 if (bpf_dump_raw_ok()) {
1731 uinsns = u64_to_user_ptr(info.jited_prog_insns);
1732 ulen = min_t(u32, info.jited_prog_len, ulen);
1733 if (copy_to_user(uinsns, prog->bpf_func, ulen))
1736 info.jited_prog_insns = 0;
1740 ulen = info.xlated_prog_len;
1741 info.xlated_prog_len = bpf_prog_insn_size(prog);
1742 if (info.xlated_prog_len && ulen) {
1743 struct bpf_insn *insns_sanitized;
1746 if (prog->blinded && !bpf_dump_raw_ok()) {
1747 info.xlated_prog_insns = 0;
1750 insns_sanitized = bpf_insn_prepare_dump(prog);
1751 if (!insns_sanitized)
1753 uinsns = u64_to_user_ptr(info.xlated_prog_insns);
1754 ulen = min_t(u32, info.xlated_prog_len, ulen);
1755 fault = copy_to_user(uinsns, insns_sanitized, ulen);
1756 kfree(insns_sanitized);
1761 if (bpf_prog_is_dev_bound(prog->aux)) {
1762 err = bpf_prog_offload_info_fill(&info, prog);
1768 if (copy_to_user(uinfo, &info, info_len) ||
1769 put_user(info_len, &uattr->info.info_len))
1775 static int bpf_map_get_info_by_fd(struct bpf_map *map,
1776 const union bpf_attr *attr,
1777 union bpf_attr __user *uattr)
1779 struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1780 struct bpf_map_info info = {};
1781 u32 info_len = attr->info.info_len;
1784 err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1787 info_len = min_t(u32, sizeof(info), info_len);
1789 info.type = map->map_type;
1791 info.key_size = map->key_size;
1792 info.value_size = map->value_size;
1793 info.max_entries = map->max_entries;
1794 info.map_flags = map->map_flags;
1795 memcpy(info.name, map->name, sizeof(map->name));
1797 if (copy_to_user(uinfo, &info, info_len) ||
1798 put_user(info_len, &uattr->info.info_len))
1804 #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
1806 static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
1807 union bpf_attr __user *uattr)
1809 int ufd = attr->info.bpf_fd;
1813 if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
1820 if (f.file->f_op == &bpf_prog_fops)
1821 err = bpf_prog_get_info_by_fd(f.file->private_data, attr,
1823 else if (f.file->f_op == &bpf_map_fops)
1824 err = bpf_map_get_info_by_fd(f.file->private_data, attr,
1833 SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
1835 union bpf_attr attr = {};
1838 if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled)
1841 err = check_uarg_tail_zero(uattr, sizeof(attr), size);
1844 size = min_t(u32, size, sizeof(attr));
1846 /* copy attributes from user space, may be less than sizeof(bpf_attr) */
1847 if (copy_from_user(&attr, uattr, size) != 0)
1850 err = security_bpf(cmd, &attr, size);
1855 case BPF_MAP_CREATE:
1856 err = map_create(&attr);
1858 case BPF_MAP_LOOKUP_ELEM:
1859 err = map_lookup_elem(&attr);
1861 case BPF_MAP_UPDATE_ELEM:
1862 err = map_update_elem(&attr);
1864 case BPF_MAP_DELETE_ELEM:
1865 err = map_delete_elem(&attr);
1867 case BPF_MAP_GET_NEXT_KEY:
1868 err = map_get_next_key(&attr);
1871 err = bpf_prog_load(&attr);
1874 err = bpf_obj_pin(&attr);
1877 err = bpf_obj_get(&attr);
1879 #ifdef CONFIG_CGROUP_BPF
1880 case BPF_PROG_ATTACH:
1881 err = bpf_prog_attach(&attr);
1883 case BPF_PROG_DETACH:
1884 err = bpf_prog_detach(&attr);
1886 case BPF_PROG_QUERY:
1887 err = bpf_prog_query(&attr, uattr);
1890 case BPF_PROG_TEST_RUN:
1891 err = bpf_prog_test_run(&attr, uattr);
1893 case BPF_PROG_GET_NEXT_ID:
1894 err = bpf_obj_get_next_id(&attr, uattr,
1895 &prog_idr, &prog_idr_lock);
1897 case BPF_MAP_GET_NEXT_ID:
1898 err = bpf_obj_get_next_id(&attr, uattr,
1899 &map_idr, &map_idr_lock);
1901 case BPF_PROG_GET_FD_BY_ID:
1902 err = bpf_prog_get_fd_by_id(&attr);
1904 case BPF_MAP_GET_FD_BY_ID:
1905 err = bpf_map_get_fd_by_id(&attr);
1907 case BPF_OBJ_GET_INFO_BY_FD:
1908 err = bpf_obj_get_info_by_fd(&attr, uattr);