/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS) #define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) #define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map)) #define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY) DEFINE_PER_CPU(int, bpf_prog_active); static DEFINE_IDR(prog_idr); static DEFINE_SPINLOCK(prog_idr_lock); static DEFINE_IDR(map_idr); static DEFINE_SPINLOCK(map_idr_lock); int sysctl_unprivileged_bpf_disabled __read_mostly; static const struct bpf_map_ops * const bpf_map_types[] = { #define BPF_PROG_TYPE(_id, _ops) #define BPF_MAP_TYPE(_id, _ops) \ [_id] = &_ops, #include #undef BPF_PROG_TYPE #undef BPF_MAP_TYPE }; /* * If we're handed a bigger struct than we know of, ensure all the unknown bits * are 0 - i.e. new user-space does not rely on any kernel feature extensions * we don't know about yet. * * There is a ToCToU between this function call and the following * copy_from_user() call. However, this is not a concern since this function is * meant to be a future-proofing of bits. */ static int check_uarg_tail_zero(void __user *uaddr, size_t expected_size, size_t actual_size) { unsigned char __user *addr; unsigned char __user *end; unsigned char val; int err; if (unlikely(actual_size > PAGE_SIZE)) /* silly large */ return -E2BIG; if (unlikely(!access_ok(VERIFY_READ, uaddr, actual_size))) return -EFAULT; if (actual_size <= expected_size) return 0; addr = uaddr + expected_size; end = uaddr + actual_size; for (; addr < end; addr++) { err = get_user(val, addr); if (err) return err; if (val) return -E2BIG; } return 0; } const struct bpf_map_ops bpf_map_offload_ops = { .map_alloc = bpf_map_offload_map_alloc, .map_free = bpf_map_offload_map_free, }; static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) { const struct bpf_map_ops *ops; u32 type = attr->map_type; struct bpf_map *map; int err; if (type >= ARRAY_SIZE(bpf_map_types)) return ERR_PTR(-EINVAL); type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types)); ops = bpf_map_types[type]; if (!ops) return ERR_PTR(-EINVAL); if (ops->map_alloc_check) { err = ops->map_alloc_check(attr); if (err) return ERR_PTR(err); } if (attr->map_ifindex) ops = &bpf_map_offload_ops; map = ops->map_alloc(attr); if (IS_ERR(map)) return map; map->ops = ops; map->map_type = type; return map; } void *bpf_map_area_alloc(size_t size, int numa_node) { /* We definitely need __GFP_NORETRY, so OOM killer doesn't * trigger under memory pressure as we really just want to * fail instead. */ const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO; void *area; if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { area = kmalloc_node(size, GFP_USER | flags, numa_node); if (area != NULL) return area; } return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags, __builtin_return_address(0)); } void bpf_map_area_free(void *area) { kvfree(area); } void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr) { map->map_type = attr->map_type; map->key_size = attr->key_size; map->value_size = attr->value_size; map->max_entries = attr->max_entries; map->map_flags = attr->map_flags; map->numa_node = bpf_map_attr_numa_node(attr); } int bpf_map_precharge_memlock(u32 pages) { struct user_struct *user = get_current_user(); unsigned long memlock_limit, cur; memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; cur = atomic_long_read(&user->locked_vm); free_uid(user); if (cur + pages > memlock_limit) return -EPERM; return 0; } static int bpf_map_charge_memlock(struct bpf_map *map) { struct user_struct *user = get_current_user(); unsigned long memlock_limit; memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; atomic_long_add(map->pages, &user->locked_vm); if (atomic_long_read(&user->locked_vm) > memlock_limit) { atomic_long_sub(map->pages, &user->locked_vm); free_uid(user); return -EPERM; } map->user = user; return 0; } static void bpf_map_uncharge_memlock(struct bpf_map *map) { struct user_struct *user = map->user; atomic_long_sub(map->pages, &user->locked_vm); free_uid(user); } static int bpf_map_alloc_id(struct bpf_map *map) { int id; idr_preload(GFP_KERNEL); spin_lock_bh(&map_idr_lock); id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC); if (id > 0) map->id = id; spin_unlock_bh(&map_idr_lock); idr_preload_end(); if (WARN_ON_ONCE(!id)) return -ENOSPC; return id > 0 ? 0 : id; } void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock) { unsigned long flags; /* Offloaded maps are removed from the IDR store when their device * disappears - even if someone holds an fd to them they are unusable, * the memory is gone, all ops will fail; they are simply waiting for * refcnt to drop to be freed. */ if (!map->id) return; if (do_idr_lock) spin_lock_irqsave(&map_idr_lock, flags); else __acquire(&map_idr_lock); idr_remove(&map_idr, map->id); map->id = 0; if (do_idr_lock) spin_unlock_irqrestore(&map_idr_lock, flags); else __release(&map_idr_lock); } /* called from workqueue */ static void bpf_map_free_deferred(struct work_struct *work) { struct bpf_map *map = container_of(work, struct bpf_map, work); bpf_map_uncharge_memlock(map); security_bpf_map_free(map); btf_put(map->btf); /* implementation dependent freeing */ map->ops->map_free(map); } static void bpf_map_put_uref(struct bpf_map *map) { if (atomic_dec_and_test(&map->usercnt)) { if (map->ops->map_release_uref) map->ops->map_release_uref(map); } } /* decrement map refcnt and schedule it for freeing via workqueue * (unrelying map implementation ops->map_free() might sleep) */ static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock) { if (atomic_dec_and_test(&map->refcnt)) { /* bpf_map_free_id() must be called first */ bpf_map_free_id(map, do_idr_lock); INIT_WORK(&map->work, bpf_map_free_deferred); schedule_work(&map->work); } } void bpf_map_put(struct bpf_map *map) { __bpf_map_put(map, true); } EXPORT_SYMBOL_GPL(bpf_map_put); void bpf_map_put_with_uref(struct bpf_map *map) { bpf_map_put_uref(map); bpf_map_put(map); } static int bpf_map_release(struct inode *inode, struct file *filp) { struct bpf_map *map = filp->private_data; if (map->ops->map_release) map->ops->map_release(map, filp); bpf_map_put_with_uref(map); return 0; } #ifdef CONFIG_PROC_FS static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) { const struct bpf_map *map = filp->private_data; const struct bpf_array *array; u32 owner_prog_type = 0; u32 owner_jited = 0; if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) { array = container_of(map, struct bpf_array, map); owner_prog_type = array->owner_prog_type; owner_jited = array->owner_jited; } seq_printf(m, "map_type:\t%u\n" "key_size:\t%u\n" "value_size:\t%u\n" "max_entries:\t%u\n" "map_flags:\t%#x\n" "memlock:\t%llu\n", map->map_type, map->key_size, map->value_size, map->max_entries, map->map_flags, map->pages * 1ULL << PAGE_SHIFT); if (owner_prog_type) { seq_printf(m, "owner_prog_type:\t%u\n", owner_prog_type); seq_printf(m, "owner_jited:\t%u\n", owner_jited); } } #endif static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz, loff_t *ppos) { /* We need this handler such that alloc_file() enables * f_mode with FMODE_CAN_READ. */ return -EINVAL; } static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf, size_t siz, loff_t *ppos) { /* We need this handler such that alloc_file() enables * f_mode with FMODE_CAN_WRITE. */ return -EINVAL; } const struct file_operations bpf_map_fops = { #ifdef CONFIG_PROC_FS .show_fdinfo = bpf_map_show_fdinfo, #endif .release = bpf_map_release, .read = bpf_dummy_read, .write = bpf_dummy_write, }; int bpf_map_new_fd(struct bpf_map *map, int flags) { int ret; ret = security_bpf_map(map, OPEN_FMODE(flags)); if (ret < 0) return ret; return anon_inode_getfd("bpf-map", &bpf_map_fops, map, flags | O_CLOEXEC); } int bpf_get_file_flag(int flags) { if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY)) return -EINVAL; if (flags & BPF_F_RDONLY) return O_RDONLY; if (flags & BPF_F_WRONLY) return O_WRONLY; return O_RDWR; } /* helper macro to check that unused fields 'union bpf_attr' are zero */ #define CHECK_ATTR(CMD) \ memchr_inv((void *) &attr->CMD##_LAST_FIELD + \ sizeof(attr->CMD##_LAST_FIELD), 0, \ sizeof(*attr) - \ offsetof(union bpf_attr, CMD##_LAST_FIELD) - \ sizeof(attr->CMD##_LAST_FIELD)) != NULL /* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes. * Return 0 on success and < 0 on error. */ static int bpf_obj_name_cpy(char *dst, const char *src) { const char *end = src + BPF_OBJ_NAME_LEN; memset(dst, 0, BPF_OBJ_NAME_LEN); /* Copy all isalnum() and '_' char */ while (src < end && *src) { if (!isalnum(*src) && *src != '_') return -EINVAL; *dst++ = *src++; } /* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */ if (src == end) return -EINVAL; return 0; } #define BPF_MAP_CREATE_LAST_FIELD btf_value_id /* called via syscall */ static int map_create(union bpf_attr *attr) { int numa_node = bpf_map_attr_numa_node(attr); struct bpf_map *map; int f_flags; int err; err = CHECK_ATTR(BPF_MAP_CREATE); if (err) return -EINVAL; f_flags = bpf_get_file_flag(attr->map_flags); if (f_flags < 0) return f_flags; if (numa_node != NUMA_NO_NODE && ((unsigned int)numa_node >= nr_node_ids || !node_online(numa_node))) return -EINVAL; /* find map type and init map: hashtable vs rbtree vs bloom vs ... */ map = find_and_alloc_map(attr); if (IS_ERR(map)) return PTR_ERR(map); err = bpf_obj_name_cpy(map->name, attr->map_name); if (err) goto free_map_nouncharge; atomic_set(&map->refcnt, 1); atomic_set(&map->usercnt, 1); if (bpf_map_support_seq_show(map) && (attr->btf_key_id || attr->btf_value_id)) { struct btf *btf; if (!attr->btf_key_id || !attr->btf_value_id) { err = -EINVAL; goto free_map_nouncharge; } btf = btf_get_by_fd(attr->btf_fd); if (IS_ERR(btf)) { err = PTR_ERR(btf); goto free_map_nouncharge; } err = map->ops->map_check_btf(map, btf, attr->btf_key_id, attr->btf_value_id); if (err) { btf_put(btf); goto free_map_nouncharge; } map->btf = btf; map->btf_key_id = attr->btf_key_id; map->btf_value_id = attr->btf_value_id; } err = security_bpf_map_alloc(map); if (err) goto free_map_nouncharge; err = bpf_map_charge_memlock(map); if (err) goto free_map_sec; err = bpf_map_alloc_id(map); if (err) goto free_map; err = bpf_map_new_fd(map, f_flags); if (err < 0) { /* failed to allocate fd. * bpf_map_put() is needed because the above * bpf_map_alloc_id() has published the map * to the userspace and the userspace may * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID. */ bpf_map_put(map); return err; } return err; free_map: bpf_map_uncharge_memlock(map); free_map_sec: security_bpf_map_free(map); free_map_nouncharge: btf_put(map->btf); map->ops->map_free(map); return err; } /* if error is returned, fd is released. * On success caller should complete fd access with matching fdput() */ struct bpf_map *__bpf_map_get(struct fd f) { if (!f.file) return ERR_PTR(-EBADF); if (f.file->f_op != &bpf_map_fops) { fdput(f); return ERR_PTR(-EINVAL); } return f.file->private_data; } /* prog's and map's refcnt limit */ #define BPF_MAX_REFCNT 32768 struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref) { if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) { atomic_dec(&map->refcnt); return ERR_PTR(-EBUSY); } if (uref) atomic_inc(&map->usercnt); return map; } EXPORT_SYMBOL_GPL(bpf_map_inc); struct bpf_map *bpf_map_get_with_uref(u32 ufd) { struct fd f = fdget(ufd); struct bpf_map *map; map = __bpf_map_get(f); if (IS_ERR(map)) return map; map = bpf_map_inc(map, true); fdput(f); return map; } /* map_idr_lock should have been held */ static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map, bool uref) { int refold; refold = __atomic_add_unless(&map->refcnt, 1, 0); if (refold >= BPF_MAX_REFCNT) { __bpf_map_put(map, false); return ERR_PTR(-EBUSY); } if (!refold) return ERR_PTR(-ENOENT); if (uref) atomic_inc(&map->usercnt); return map; } int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) { return -ENOTSUPP; } /* last field in 'union bpf_attr' used by this command */ #define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value static int map_lookup_elem(union bpf_attr *attr) { void __user *ukey = u64_to_user_ptr(attr->key); void __user *uvalue = u64_to_user_ptr(attr->value); int ufd = attr->map_fd; struct bpf_map *map; void *key, *value, *ptr; u32 value_size; struct fd f; int err; if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM)) return -EINVAL; f = fdget(ufd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); if (!(f.file->f_mode & FMODE_CAN_READ)) { err = -EPERM; goto err_put; } key = memdup_user(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); goto err_put; } if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) value_size = round_up(map->value_size, 8) * num_possible_cpus(); else if (IS_FD_MAP(map)) value_size = sizeof(u32); else value_size = map->value_size; err = -ENOMEM; value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); if (!value) goto free_key; if (bpf_map_is_dev_bound(map)) { err = bpf_map_offload_lookup_elem(map, key, value); } else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { err = bpf_percpu_hash_copy(map, key, value); } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { err = bpf_percpu_array_copy(map, key, value); } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { err = bpf_stackmap_copy(map, key, value); } else if (IS_FD_ARRAY(map)) { err = bpf_fd_array_map_lookup_elem(map, key, value); } else if (IS_FD_HASH(map)) { err = bpf_fd_htab_map_lookup_elem(map, key, value); } else { rcu_read_lock(); ptr = map->ops->map_lookup_elem(map, key); if (ptr) memcpy(value, ptr, value_size); rcu_read_unlock(); err = ptr ? 0 : -ENOENT; } if (err) goto free_value; err = -EFAULT; if (copy_to_user(uvalue, value, value_size) != 0) goto free_value; err = 0; free_value: kfree(value); free_key: kfree(key); err_put: fdput(f); return err; } #define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags static int map_update_elem(union bpf_attr *attr) { void __user *ukey = u64_to_user_ptr(attr->key); void __user *uvalue = u64_to_user_ptr(attr->value); int ufd = attr->map_fd; struct bpf_map *map; void *key, *value; u32 value_size; struct fd f; int err; if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM)) return -EINVAL; f = fdget(ufd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); if (!(f.file->f_mode & FMODE_CAN_WRITE)) { err = -EPERM; goto err_put; } key = memdup_user(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); goto err_put; } if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) value_size = round_up(map->value_size, 8) * num_possible_cpus(); else value_size = map->value_size; err = -ENOMEM; value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); if (!value) goto free_key; err = -EFAULT; if (copy_from_user(value, uvalue, value_size) != 0) goto free_value; /* Need to create a kthread, thus must support schedule */ if (bpf_map_is_dev_bound(map)) { err = bpf_map_offload_update_elem(map, key, value, attr->flags); goto out; } else if (map->map_type == BPF_MAP_TYPE_CPUMAP) { err = map->ops->map_update_elem(map, key, value, attr->flags); goto out; } /* must increment bpf_prog_active to avoid kprobe+bpf triggering from * inside bpf map update or delete otherwise deadlocks are possible */ preempt_disable(); __this_cpu_inc(bpf_prog_active); if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { err = bpf_percpu_hash_update(map, key, value, attr->flags); } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { err = bpf_percpu_array_update(map, key, value, attr->flags); } else if (IS_FD_ARRAY(map)) { rcu_read_lock(); err = bpf_fd_array_map_update_elem(map, f.file, key, value, attr->flags); rcu_read_unlock(); } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { rcu_read_lock(); err = bpf_fd_htab_map_update_elem(map, f.file, key, value, attr->flags); rcu_read_unlock(); } else { rcu_read_lock(); err = map->ops->map_update_elem(map, key, value, attr->flags); rcu_read_unlock(); } __this_cpu_dec(bpf_prog_active); preempt_enable(); out: free_value: kfree(value); free_key: kfree(key); err_put: fdput(f); return err; } #define BPF_MAP_DELETE_ELEM_LAST_FIELD key static int map_delete_elem(union bpf_attr *attr) { void __user *ukey = u64_to_user_ptr(attr->key); int ufd = attr->map_fd; struct bpf_map *map; struct fd f; void *key; int err; if (CHECK_ATTR(BPF_MAP_DELETE_ELEM)) return -EINVAL; f = fdget(ufd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); if (!(f.file->f_mode & FMODE_CAN_WRITE)) { err = -EPERM; goto err_put; } key = memdup_user(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); goto err_put; } if (bpf_map_is_dev_bound(map)) { err = bpf_map_offload_delete_elem(map, key); goto out; } preempt_disable(); __this_cpu_inc(bpf_prog_active); rcu_read_lock(); err = map->ops->map_delete_elem(map, key); rcu_read_unlock(); __this_cpu_dec(bpf_prog_active); preempt_enable(); out: kfree(key); err_put: fdput(f); return err; } /* last field in 'union bpf_attr' used by this command */ #define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key static int map_get_next_key(union bpf_attr *attr) { void __user *ukey = u64_to_user_ptr(attr->key); void __user *unext_key = u64_to_user_ptr(attr->next_key); int ufd = attr->map_fd; struct bpf_map *map; void *key, *next_key; struct fd f; int err; if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY)) return -EINVAL; f = fdget(ufd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); if (!(f.file->f_mode & FMODE_CAN_READ)) { err = -EPERM; goto err_put; } if (ukey) { key = memdup_user(ukey, map->key_size); if (IS_ERR(key)) { err = PTR_ERR(key); goto err_put; } } else { key = NULL; } err = -ENOMEM; next_key = kmalloc(map->key_size, GFP_USER); if (!next_key) goto free_key; if (bpf_map_is_dev_bound(map)) { err = bpf_map_offload_get_next_key(map, key, next_key); goto out; } rcu_read_lock(); err = map->ops->map_get_next_key(map, key, next_key); rcu_read_unlock(); out: if (err) goto free_next_key; err = -EFAULT; if (copy_to_user(unext_key, next_key, map->key_size) != 0) goto free_next_key; err = 0; free_next_key: kfree(next_key); free_key: kfree(key); err_put: fdput(f); return err; } static const struct bpf_prog_ops * const bpf_prog_types[] = { #define BPF_PROG_TYPE(_id, _name) \ [_id] = & _name ## _prog_ops, #define BPF_MAP_TYPE(_id, _ops) #include #undef BPF_PROG_TYPE #undef BPF_MAP_TYPE }; static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) { const struct bpf_prog_ops *ops; if (type >= ARRAY_SIZE(bpf_prog_types)) return -EINVAL; type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); ops = bpf_prog_types[type]; if (!ops) return -EINVAL; if (!bpf_prog_is_dev_bound(prog->aux)) prog->aux->ops = ops; else prog->aux->ops = &bpf_offload_prog_ops; prog->type = type; return 0; } /* drop refcnt on maps used by eBPF program and free auxilary data */ static void free_used_maps(struct bpf_prog_aux *aux) { int i; for (i = 0; i < aux->used_map_cnt; i++) bpf_map_put(aux->used_maps[i]); kfree(aux->used_maps); } int __bpf_prog_charge(struct user_struct *user, u32 pages) { unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; unsigned long user_bufs; if (user) { user_bufs = atomic_long_add_return(pages, &user->locked_vm); if (user_bufs > memlock_limit) { atomic_long_sub(pages, &user->locked_vm); return -EPERM; } } return 0; } void __bpf_prog_uncharge(struct user_struct *user, u32 pages) { if (user) atomic_long_sub(pages, &user->locked_vm); } static int bpf_prog_charge_memlock(struct bpf_prog *prog) { struct user_struct *user = get_current_user(); int ret; ret = __bpf_prog_charge(user, prog->pages); if (ret) { free_uid(user); return ret; } prog->aux->user = user; return 0; } static void bpf_prog_uncharge_memlock(struct bpf_prog *prog) { struct user_struct *user = prog->aux->user; __bpf_prog_uncharge(user, prog->pages); free_uid(user); } static int bpf_prog_alloc_id(struct bpf_prog *prog) { int id; idr_preload(GFP_KERNEL); spin_lock_bh(&prog_idr_lock); id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC); if (id > 0) prog->aux->id = id; spin_unlock_bh(&prog_idr_lock); idr_preload_end(); /* id is in [1, INT_MAX) */ if (WARN_ON_ONCE(!id)) return -ENOSPC; return id > 0 ? 0 : id; } void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock) { /* cBPF to eBPF migrations are currently not in the idr store. * Offloaded programs are removed from the store when their device * disappears - even if someone grabs an fd to them they are unusable, * simply waiting for refcnt to drop to be freed. */ if (!prog->aux->id) return; if (do_idr_lock) spin_lock_bh(&prog_idr_lock); else __acquire(&prog_idr_lock); idr_remove(&prog_idr, prog->aux->id); prog->aux->id = 0; if (do_idr_lock) spin_unlock_bh(&prog_idr_lock); else __release(&prog_idr_lock); } static void __bpf_prog_put_rcu(struct rcu_head *rcu) { struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); free_used_maps(aux); bpf_prog_uncharge_memlock(aux->prog); security_bpf_prog_free(aux); bpf_prog_free(aux->prog); } static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) { if (atomic_dec_and_test(&prog->aux->refcnt)) { int i; /* bpf_prog_free_id() must be called first */ bpf_prog_free_id(prog, do_idr_lock); for (i = 0; i < prog->aux->func_cnt; i++) bpf_prog_kallsyms_del(prog->aux->func[i]); bpf_prog_kallsyms_del(prog); call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); } } void bpf_prog_put(struct bpf_prog *prog) { __bpf_prog_put(prog, true); } EXPORT_SYMBOL_GPL(bpf_prog_put); static int bpf_prog_release(struct inode *inode, struct file *filp) { struct bpf_prog *prog = filp->private_data; bpf_prog_put(prog); return 0; } #ifdef CONFIG_PROC_FS static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp) { const struct bpf_prog *prog = filp->private_data; char prog_tag[sizeof(prog->tag) * 2 + 1] = { }; bin2hex(prog_tag, prog->tag, sizeof(prog->tag)); seq_printf(m, "prog_type:\t%u\n" "prog_jited:\t%u\n" "prog_tag:\t%s\n" "memlock:\t%llu\n", prog->type, prog->jited, prog_tag, prog->pages * 1ULL << PAGE_SHIFT); } #endif const struct file_operations bpf_prog_fops = { #ifdef CONFIG_PROC_FS .show_fdinfo = bpf_prog_show_fdinfo, #endif .release = bpf_prog_release, .read = bpf_dummy_read, .write = bpf_dummy_write, }; int bpf_prog_new_fd(struct bpf_prog *prog) { int ret; ret = security_bpf_prog(prog); if (ret < 0) return ret; return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog, O_RDWR | O_CLOEXEC); } static struct bpf_prog *____bpf_prog_get(struct fd f) { if (!f.file) return ERR_PTR(-EBADF); if (f.file->f_op != &bpf_prog_fops) { fdput(f); return ERR_PTR(-EINVAL); } return f.file->private_data; } struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i) { if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) { atomic_sub(i, &prog->aux->refcnt); return ERR_PTR(-EBUSY); } return prog; } EXPORT_SYMBOL_GPL(bpf_prog_add); void bpf_prog_sub(struct bpf_prog *prog, int i) { /* Only to be used for undoing previous bpf_prog_add() in some * error path. We still know that another entity in our call * path holds a reference to the program, thus atomic_sub() can * be safely used in such cases! */ WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0); } EXPORT_SYMBOL_GPL(bpf_prog_sub); struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog) { return bpf_prog_add(prog, 1); } EXPORT_SYMBOL_GPL(bpf_prog_inc); /* prog_idr_lock should have been held */ struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog) { int refold; refold = __atomic_add_unless(&prog->aux->refcnt, 1, 0); if (refold >= BPF_MAX_REFCNT) { __bpf_prog_put(prog, false); return ERR_PTR(-EBUSY); } if (!refold) return ERR_PTR(-ENOENT); return prog; } EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero); bool bpf_prog_get_ok(struct bpf_prog *prog, enum bpf_prog_type *attach_type, bool attach_drv) { /* not an attachment, just a refcount inc, always allow */ if (!attach_type) return true; if (prog->type != *attach_type) return false; if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv) return false; return true; } static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type, bool attach_drv) { struct fd f = fdget(ufd); struct bpf_prog *prog; prog = ____bpf_prog_get(f); if (IS_ERR(prog)) return prog; if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) { prog = ERR_PTR(-EINVAL); goto out; } prog = bpf_prog_inc(prog); out: fdput(f); return prog; } struct bpf_prog *bpf_prog_get(u32 ufd) { return __bpf_prog_get(ufd, NULL, false); } struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type, bool attach_drv) { return __bpf_prog_get(ufd, &type, attach_drv); } EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev); /* Initially all BPF programs could be loaded w/o specifying * expected_attach_type. Later for some of them specifying expected_attach_type * at load time became required so that program could be validated properly. * Programs of types that are allowed to be loaded both w/ and w/o (for * backward compatibility) expected_attach_type, should have the default attach * type assigned to expected_attach_type for the latter case, so that it can be * validated later at attach time. * * bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if * prog type requires it but has some attach types that have to be backward * compatible. */ static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) { switch (attr->prog_type) { case BPF_PROG_TYPE_CGROUP_SOCK: /* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't * exist so checking for non-zero is the way to go here. */ if (!attr->expected_attach_type) attr->expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE; break; } } static int bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type, enum bpf_attach_type expected_attach_type) { switch (prog_type) { case BPF_PROG_TYPE_CGROUP_SOCK: switch (expected_attach_type) { case BPF_CGROUP_INET_SOCK_CREATE: case BPF_CGROUP_INET4_POST_BIND: case BPF_CGROUP_INET6_POST_BIND: return 0; default: return -EINVAL; } case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: switch (expected_attach_type) { case BPF_CGROUP_INET4_BIND: case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: return 0; default: return -EINVAL; } default: return 0; } } /* last field in 'union bpf_attr' used by this command */ #define BPF_PROG_LOAD_LAST_FIELD expected_attach_type static int bpf_prog_load(union bpf_attr *attr) { enum bpf_prog_type type = attr->prog_type; struct bpf_prog *prog; int err; char license[128]; bool is_gpl; if (CHECK_ATTR(BPF_PROG_LOAD)) return -EINVAL; if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT) return -EINVAL; /* copy eBPF program license from user space */ if (strncpy_from_user(license, u64_to_user_ptr(attr->license), sizeof(license) - 1) < 0) return -EFAULT; license[sizeof(license) - 1] = 0; /* eBPF programs must be GPL compatible to use GPL-ed functions */ is_gpl = license_is_gpl_compatible(license); if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS) return -E2BIG; if (type == BPF_PROG_TYPE_KPROBE && attr->kern_version != LINUX_VERSION_CODE) return -EINVAL; if (type != BPF_PROG_TYPE_SOCKET_FILTER && type != BPF_PROG_TYPE_CGROUP_SKB && !capable(CAP_SYS_ADMIN)) return -EPERM; bpf_prog_load_fixup_attach_type(attr); if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type)) return -EINVAL; /* plain bpf_prog allocation */ prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER); if (!prog) return -ENOMEM; prog->expected_attach_type = attr->expected_attach_type; prog->aux->offload_requested = !!attr->prog_ifindex; err = security_bpf_prog_alloc(prog->aux); if (err) goto free_prog_nouncharge; err = bpf_prog_charge_memlock(prog); if (err) goto free_prog_sec; prog->len = attr->insn_cnt; err = -EFAULT; if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns), bpf_prog_insn_size(prog)) != 0) goto free_prog; prog->orig_prog = NULL; prog->jited = 0; atomic_set(&prog->aux->refcnt, 1); prog->gpl_compatible = is_gpl ? 1 : 0; if (bpf_prog_is_dev_bound(prog->aux)) { err = bpf_prog_offload_init(prog, attr); if (err) goto free_prog; } /* find program type: socket_filter vs tracing_filter */ err = find_prog_type(type, prog); if (err < 0) goto free_prog; prog->aux->load_time = ktime_get_boot_ns(); err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name); if (err) goto free_prog; /* run eBPF verifier */ err = bpf_check(&prog, attr); if (err < 0) goto free_used_maps; /* eBPF program is ready to be JITed */ if (!prog->bpf_func) prog = bpf_prog_select_runtime(prog, &err); if (err < 0) goto free_used_maps; err = bpf_prog_alloc_id(prog); if (err) goto free_used_maps; err = bpf_prog_new_fd(prog); if (err < 0) { /* failed to allocate fd. * bpf_prog_put() is needed because the above * bpf_prog_alloc_id() has published the prog * to the userspace and the userspace may * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID. */ bpf_prog_put(prog); return err; } bpf_prog_kallsyms_add(prog); return err; free_used_maps: free_used_maps(prog->aux); free_prog: bpf_prog_uncharge_memlock(prog); free_prog_sec: security_bpf_prog_free(prog->aux); free_prog_nouncharge: bpf_prog_free(prog); return err; } #define BPF_OBJ_LAST_FIELD file_flags static int bpf_obj_pin(const union bpf_attr *attr) { if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0) return -EINVAL; return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname)); } static int bpf_obj_get(const union bpf_attr *attr) { if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 || attr->file_flags & ~BPF_OBJ_FLAG_MASK) return -EINVAL; return bpf_obj_get_user(u64_to_user_ptr(attr->pathname), attr->file_flags); } struct bpf_raw_tracepoint { struct bpf_raw_event_map *btp; struct bpf_prog *prog; }; static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp) { struct bpf_raw_tracepoint *raw_tp = filp->private_data; if (raw_tp->prog) { bpf_probe_unregister(raw_tp->btp, raw_tp->prog); bpf_prog_put(raw_tp->prog); } kfree(raw_tp); return 0; } static const struct file_operations bpf_raw_tp_fops = { .release = bpf_raw_tracepoint_release, .read = bpf_dummy_read, .write = bpf_dummy_write, }; #define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd static int bpf_raw_tracepoint_open(const union bpf_attr *attr) { struct bpf_raw_tracepoint *raw_tp; struct bpf_raw_event_map *btp; struct bpf_prog *prog; char tp_name[128]; int tp_fd, err; if (strncpy_from_user(tp_name, u64_to_user_ptr(attr->raw_tracepoint.name), sizeof(tp_name) - 1) < 0) return -EFAULT; tp_name[sizeof(tp_name) - 1] = 0; btp = bpf_find_raw_tracepoint(tp_name); if (!btp) return -ENOENT; raw_tp = kzalloc(sizeof(*raw_tp), GFP_USER); if (!raw_tp) return -ENOMEM; raw_tp->btp = btp; prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd, BPF_PROG_TYPE_RAW_TRACEPOINT); if (IS_ERR(prog)) { err = PTR_ERR(prog); goto out_free_tp; } err = bpf_probe_register(raw_tp->btp, prog); if (err) goto out_put_prog; raw_tp->prog = prog; tp_fd = anon_inode_getfd("bpf-raw-tracepoint", &bpf_raw_tp_fops, raw_tp, O_CLOEXEC); if (tp_fd < 0) { bpf_probe_unregister(raw_tp->btp, prog); err = tp_fd; goto out_put_prog; } return tp_fd; out_put_prog: bpf_prog_put(prog); out_free_tp: kfree(raw_tp); return err; } #ifdef CONFIG_CGROUP_BPF static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, enum bpf_attach_type attach_type) { switch (prog->type) { case BPF_PROG_TYPE_CGROUP_SOCK: case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: return attach_type == prog->expected_attach_type ? 0 : -EINVAL; default: return 0; } } #define BPF_PROG_ATTACH_LAST_FIELD attach_flags static int sockmap_get_from_fd(const union bpf_attr *attr, int type, bool attach) { struct bpf_prog *prog = NULL; int ufd = attr->target_fd; struct bpf_map *map; struct fd f; int err; f = fdget(ufd); map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); if (attach) { prog = bpf_prog_get_type(attr->attach_bpf_fd, type); if (IS_ERR(prog)) { fdput(f); return PTR_ERR(prog); } } err = sock_map_prog(map, prog, attr->attach_type); if (err) { fdput(f); if (prog) bpf_prog_put(prog); return err; } fdput(f); return 0; } #define BPF_F_ATTACH_MASK \ (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI) static int bpf_prog_attach(const union bpf_attr *attr) { enum bpf_prog_type ptype; struct bpf_prog *prog; struct cgroup *cgrp; int ret; if (!capable(CAP_NET_ADMIN)) return -EPERM; if (CHECK_ATTR(BPF_PROG_ATTACH)) return -EINVAL; if (attr->attach_flags & ~BPF_F_ATTACH_MASK) return -EINVAL; switch (attr->attach_type) { case BPF_CGROUP_INET_INGRESS: case BPF_CGROUP_INET_EGRESS: ptype = BPF_PROG_TYPE_CGROUP_SKB; break; case BPF_CGROUP_INET_SOCK_CREATE: case BPF_CGROUP_INET4_POST_BIND: case BPF_CGROUP_INET6_POST_BIND: ptype = BPF_PROG_TYPE_CGROUP_SOCK; break; case BPF_CGROUP_INET4_BIND: case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR; break; case BPF_CGROUP_SOCK_OPS: ptype = BPF_PROG_TYPE_SOCK_OPS; break; case BPF_CGROUP_DEVICE: ptype = BPF_PROG_TYPE_CGROUP_DEVICE; break; case BPF_SK_MSG_VERDICT: return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, true); case BPF_SK_SKB_STREAM_PARSER: case BPF_SK_SKB_STREAM_VERDICT: return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, true); default: return -EINVAL; } prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); if (IS_ERR(prog)) return PTR_ERR(prog); if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) { bpf_prog_put(prog); return -EINVAL; } cgrp = cgroup_get_from_fd(attr->target_fd); if (IS_ERR(cgrp)) { bpf_prog_put(prog); return PTR_ERR(cgrp); } ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type, attr->attach_flags); if (ret) bpf_prog_put(prog); cgroup_put(cgrp); return ret; } #define BPF_PROG_DETACH_LAST_FIELD attach_type static int bpf_prog_detach(const union bpf_attr *attr) { enum bpf_prog_type ptype; struct bpf_prog *prog; struct cgroup *cgrp; int ret; if (!capable(CAP_NET_ADMIN)) return -EPERM; if (CHECK_ATTR(BPF_PROG_DETACH)) return -EINVAL; switch (attr->attach_type) { case BPF_CGROUP_INET_INGRESS: case BPF_CGROUP_INET_EGRESS: ptype = BPF_PROG_TYPE_CGROUP_SKB; break; case BPF_CGROUP_INET_SOCK_CREATE: case BPF_CGROUP_INET4_POST_BIND: case BPF_CGROUP_INET6_POST_BIND: ptype = BPF_PROG_TYPE_CGROUP_SOCK; break; case BPF_CGROUP_INET4_BIND: case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR; break; case BPF_CGROUP_SOCK_OPS: ptype = BPF_PROG_TYPE_SOCK_OPS; break; case BPF_CGROUP_DEVICE: ptype = BPF_PROG_TYPE_CGROUP_DEVICE; break; case BPF_SK_MSG_VERDICT: return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, false); case BPF_SK_SKB_STREAM_PARSER: case BPF_SK_SKB_STREAM_VERDICT: return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, false); default: return -EINVAL; } cgrp = cgroup_get_from_fd(attr->target_fd); if (IS_ERR(cgrp)) return PTR_ERR(cgrp); prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype); if (IS_ERR(prog)) prog = NULL; ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0); if (prog) bpf_prog_put(prog); cgroup_put(cgrp); return ret; } #define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt static int bpf_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr) { struct cgroup *cgrp; int ret; if (!capable(CAP_NET_ADMIN)) return -EPERM; if (CHECK_ATTR(BPF_PROG_QUERY)) return -EINVAL; if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE) return -EINVAL; switch (attr->query.attach_type) { case BPF_CGROUP_INET_INGRESS: case BPF_CGROUP_INET_EGRESS: case BPF_CGROUP_INET_SOCK_CREATE: case BPF_CGROUP_INET4_BIND: case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_POST_BIND: case BPF_CGROUP_INET6_POST_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: case BPF_CGROUP_SOCK_OPS: case BPF_CGROUP_DEVICE: break; default: return -EINVAL; } cgrp = cgroup_get_from_fd(attr->query.target_fd); if (IS_ERR(cgrp)) return PTR_ERR(cgrp); ret = cgroup_bpf_query(cgrp, attr, uattr); cgroup_put(cgrp); return ret; } #endif /* CONFIG_CGROUP_BPF */ #define BPF_PROG_TEST_RUN_LAST_FIELD test.duration static int bpf_prog_test_run(const union bpf_attr *attr, union bpf_attr __user *uattr) { struct bpf_prog *prog; int ret = -ENOTSUPP; if (!capable(CAP_SYS_ADMIN)) return -EPERM; if (CHECK_ATTR(BPF_PROG_TEST_RUN)) return -EINVAL; prog = bpf_prog_get(attr->test.prog_fd); if (IS_ERR(prog)) return PTR_ERR(prog); if (prog->aux->ops->test_run) ret = prog->aux->ops->test_run(prog, attr, uattr); bpf_prog_put(prog); return ret; } #define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id static int bpf_obj_get_next_id(const union bpf_attr *attr, union bpf_attr __user *uattr, struct idr *idr, spinlock_t *lock) { u32 next_id = attr->start_id; int err = 0; if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; next_id++; spin_lock_bh(lock); if (!idr_get_next(idr, &next_id)) err = -ENOENT; spin_unlock_bh(lock); if (!err) err = put_user(next_id, &uattr->next_id); return err; } #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id static int bpf_prog_get_fd_by_id(const union bpf_attr *attr) { struct bpf_prog *prog; u32 id = attr->prog_id; int fd; if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID)) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; spin_lock_bh(&prog_idr_lock); prog = idr_find(&prog_idr, id); if (prog) prog = bpf_prog_inc_not_zero(prog); else prog = ERR_PTR(-ENOENT); spin_unlock_bh(&prog_idr_lock); if (IS_ERR(prog)) return PTR_ERR(prog); fd = bpf_prog_new_fd(prog); if (fd < 0) bpf_prog_put(prog); return fd; } #define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags static int bpf_map_get_fd_by_id(const union bpf_attr *attr) { struct bpf_map *map; u32 id = attr->map_id; int f_flags; int fd; if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) || attr->open_flags & ~BPF_OBJ_FLAG_MASK) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; f_flags = bpf_get_file_flag(attr->open_flags); if (f_flags < 0) return f_flags; spin_lock_bh(&map_idr_lock); map = idr_find(&map_idr, id); if (map) map = bpf_map_inc_not_zero(map, true); else map = ERR_PTR(-ENOENT); spin_unlock_bh(&map_idr_lock); if (IS_ERR(map)) return PTR_ERR(map); fd = bpf_map_new_fd(map, f_flags); if (fd < 0) bpf_map_put(map); return fd; } static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, unsigned long addr) { int i; for (i = 0; i < prog->aux->used_map_cnt; i++) if (prog->aux->used_maps[i] == (void *)addr) return prog->aux->used_maps[i]; return NULL; } static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog) { const struct bpf_map *map; struct bpf_insn *insns; u64 imm; int i; insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), GFP_USER); if (!insns) return insns; for (i = 0; i < prog->len; i++) { if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) { insns[i].code = BPF_JMP | BPF_CALL; insns[i].imm = BPF_FUNC_tail_call; /* fall-through */ } if (insns[i].code == (BPF_JMP | BPF_CALL) || insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) { if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) insns[i].code = BPF_JMP | BPF_CALL; if (!bpf_dump_raw_ok()) insns[i].imm = 0; continue; } if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW)) continue; imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; map = bpf_map_from_imm(prog, imm); if (map) { insns[i].src_reg = BPF_PSEUDO_MAP_FD; insns[i].imm = map->id; insns[i + 1].imm = 0; continue; } if (!bpf_dump_raw_ok() && imm == (unsigned long)prog->aux) { insns[i].imm = 0; insns[i + 1].imm = 0; continue; } } return insns; } static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, const union bpf_attr *attr, union bpf_attr __user *uattr) { struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info); struct bpf_prog_info info = {}; u32 info_len = attr->info.info_len; char __user *uinsns; u32 ulen; int err; err = check_uarg_tail_zero(uinfo, sizeof(info), info_len); if (err) return err; info_len = min_t(u32, sizeof(info), info_len); if (copy_from_user(&info, uinfo, info_len)) return -EFAULT; info.type = prog->type; info.id = prog->aux->id; info.load_time = prog->aux->load_time; info.created_by_uid = from_kuid_munged(current_user_ns(), prog->aux->user->uid); info.gpl_compatible = prog->gpl_compatible; memcpy(info.tag, prog->tag, sizeof(prog->tag)); memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); ulen = info.nr_map_ids; info.nr_map_ids = prog->aux->used_map_cnt; ulen = min_t(u32, info.nr_map_ids, ulen); if (ulen) { u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids); u32 i; for (i = 0; i < ulen; i++) if (put_user(prog->aux->used_maps[i]->id, &user_map_ids[i])) return -EFAULT; } if (!capable(CAP_SYS_ADMIN)) { info.jited_prog_len = 0; info.xlated_prog_len = 0; goto done; } ulen = info.xlated_prog_len; info.xlated_prog_len = bpf_prog_insn_size(prog); if (info.xlated_prog_len && ulen) { struct bpf_insn *insns_sanitized; bool fault; if (prog->blinded && !bpf_dump_raw_ok()) { info.xlated_prog_insns = 0; goto done; } insns_sanitized = bpf_insn_prepare_dump(prog); if (!insns_sanitized) return -ENOMEM; uinsns = u64_to_user_ptr(info.xlated_prog_insns); ulen = min_t(u32, info.xlated_prog_len, ulen); fault = copy_to_user(uinsns, insns_sanitized, ulen); kfree(insns_sanitized); if (fault) return -EFAULT; } if (bpf_prog_is_dev_bound(prog->aux)) { err = bpf_prog_offload_info_fill(&info, prog); if (err) return err; goto done; } /* NOTE: the following code is supposed to be skipped for offload. * bpf_prog_offload_info_fill() is the place to fill similar fields * for offload. */ ulen = info.jited_prog_len; info.jited_prog_len = prog->jited_len; if (info.jited_prog_len && ulen) { if (bpf_dump_raw_ok()) { uinsns = u64_to_user_ptr(info.jited_prog_insns); ulen = min_t(u32, info.jited_prog_len, ulen); if (copy_to_user(uinsns, prog->bpf_func, ulen)) return -EFAULT; } else { info.jited_prog_insns = 0; } } done: if (copy_to_user(uinfo, &info, info_len) || put_user(info_len, &uattr->info.info_len)) return -EFAULT; return 0; } static int bpf_map_get_info_by_fd(struct bpf_map *map, const union bpf_attr *attr, union bpf_attr __user *uattr) { struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info); struct bpf_map_info info = {}; u32 info_len = attr->info.info_len; int err; err = check_uarg_tail_zero(uinfo, sizeof(info), info_len); if (err) return err; info_len = min_t(u32, sizeof(info), info_len); info.type = map->map_type; info.id = map->id; info.key_size = map->key_size; info.value_size = map->value_size; info.max_entries = map->max_entries; info.map_flags = map->map_flags; memcpy(info.name, map->name, sizeof(map->name)); if (bpf_map_is_dev_bound(map)) { err = bpf_map_offload_info_fill(&info, map); if (err) return err; } if (copy_to_user(uinfo, &info, info_len) || put_user(info_len, &uattr->info.info_len)) return -EFAULT; return 0; } #define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, union bpf_attr __user *uattr) { int ufd = attr->info.bpf_fd; struct fd f; int err; if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD)) return -EINVAL; f = fdget(ufd); if (!f.file) return -EBADFD; if (f.file->f_op == &bpf_prog_fops) err = bpf_prog_get_info_by_fd(f.file->private_data, attr, uattr); else if (f.file->f_op == &bpf_map_fops) err = bpf_map_get_info_by_fd(f.file->private_data, attr, uattr); else if (f.file->f_op == &btf_fops) err = btf_get_info_by_fd(f.file->private_data, attr, uattr); else err = -EINVAL; fdput(f); return err; } #define BPF_BTF_LOAD_LAST_FIELD btf_log_level static int bpf_btf_load(const union bpf_attr *attr) { if (CHECK_ATTR(BPF_BTF_LOAD)) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; return btf_new_fd(attr); } SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) { union bpf_attr attr = {}; int err; if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN)) return -EPERM; err = check_uarg_tail_zero(uattr, sizeof(attr), size); if (err) return err; size = min_t(u32, size, sizeof(attr)); /* copy attributes from user space, may be less than sizeof(bpf_attr) */ if (copy_from_user(&attr, uattr, size) != 0) return -EFAULT; err = security_bpf(cmd, &attr, size); if (err < 0) return err; switch (cmd) { case BPF_MAP_CREATE: err = map_create(&attr); break; case BPF_MAP_LOOKUP_ELEM: err = map_lookup_elem(&attr); break; case BPF_MAP_UPDATE_ELEM: err = map_update_elem(&attr); break; case BPF_MAP_DELETE_ELEM: err = map_delete_elem(&attr); break; case BPF_MAP_GET_NEXT_KEY: err = map_get_next_key(&attr); break; case BPF_PROG_LOAD: err = bpf_prog_load(&attr); break; case BPF_OBJ_PIN: err = bpf_obj_pin(&attr); break; case BPF_OBJ_GET: err = bpf_obj_get(&attr); break; #ifdef CONFIG_CGROUP_BPF case BPF_PROG_ATTACH: err = bpf_prog_attach(&attr); break; case BPF_PROG_DETACH: err = bpf_prog_detach(&attr); break; case BPF_PROG_QUERY: err = bpf_prog_query(&attr, uattr); break; #endif case BPF_PROG_TEST_RUN: err = bpf_prog_test_run(&attr, uattr); break; case BPF_PROG_GET_NEXT_ID: err = bpf_obj_get_next_id(&attr, uattr, &prog_idr, &prog_idr_lock); break; case BPF_MAP_GET_NEXT_ID: err = bpf_obj_get_next_id(&attr, uattr, &map_idr, &map_idr_lock); break; case BPF_PROG_GET_FD_BY_ID: err = bpf_prog_get_fd_by_id(&attr); break; case BPF_MAP_GET_FD_BY_ID: err = bpf_map_get_fd_by_id(&attr); break; case BPF_OBJ_GET_INFO_BY_FD: err = bpf_obj_get_info_by_fd(&attr, uattr); break; case BPF_RAW_TRACEPOINT_OPEN: err = bpf_raw_tracepoint_open(&attr); break; case BPF_BTF_LOAD: err = bpf_btf_load(&attr); break; default: err = -EINVAL; break; } return err; }