| // SPDX-License-Identifier: GPL-2.0-only | 
 | /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com | 
 |  * Copyright (c) 2016 Facebook | 
 |  */ | 
 | #include <linux/bpf.h> | 
 | #include <linux/btf.h> | 
 | #include <linux/jhash.h> | 
 | #include <linux/filter.h> | 
 | #include <linux/rculist_nulls.h> | 
 | #include <linux/random.h> | 
 | #include <uapi/linux/btf.h> | 
 | #include "percpu_freelist.h" | 
 | #include "bpf_lru_list.h" | 
 | #include "map_in_map.h" | 
 |  | 
 | #define HTAB_CREATE_FLAG_MASK						\ | 
 | 	(BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE |	\ | 
 | 	 BPF_F_ACCESS_MASK | BPF_F_ZERO_SEED) | 
 |  | 
 | struct bucket { | 
 | 	struct hlist_nulls_head head; | 
 | 	raw_spinlock_t lock; | 
 | }; | 
 |  | 
 | struct bpf_htab { | 
 | 	struct bpf_map map; | 
 | 	struct bucket *buckets; | 
 | 	void *elems; | 
 | 	union { | 
 | 		struct pcpu_freelist freelist; | 
 | 		struct bpf_lru lru; | 
 | 	}; | 
 | 	struct htab_elem *__percpu *extra_elems; | 
 | 	atomic_t count;	/* number of elements in this hashtable */ | 
 | 	u32 n_buckets;	/* number of hash buckets */ | 
 | 	u32 elem_size;	/* size of each element in bytes */ | 
 | 	u32 hashrnd; | 
 | }; | 
 |  | 
 | /* each htab element is struct htab_elem + key + value */ | 
 | struct htab_elem { | 
 | 	union { | 
 | 		struct hlist_nulls_node hash_node; | 
 | 		struct { | 
 | 			void *padding; | 
 | 			union { | 
 | 				struct bpf_htab *htab; | 
 | 				struct pcpu_freelist_node fnode; | 
 | 			}; | 
 | 		}; | 
 | 	}; | 
 | 	union { | 
 | 		struct rcu_head rcu; | 
 | 		struct bpf_lru_node lru_node; | 
 | 	}; | 
 | 	u32 hash; | 
 | 	char key[0] __aligned(8); | 
 | }; | 
 |  | 
 | static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node); | 
 |  | 
 | static bool htab_is_lru(const struct bpf_htab *htab) | 
 | { | 
 | 	return htab->map.map_type == BPF_MAP_TYPE_LRU_HASH || | 
 | 		htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH; | 
 | } | 
 |  | 
 | static bool htab_is_percpu(const struct bpf_htab *htab) | 
 | { | 
 | 	return htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH || | 
 | 		htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH; | 
 | } | 
 |  | 
 | static bool htab_is_prealloc(const struct bpf_htab *htab) | 
 | { | 
 | 	return !(htab->map.map_flags & BPF_F_NO_PREALLOC); | 
 | } | 
 |  | 
 | static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size, | 
 | 				     void __percpu *pptr) | 
 | { | 
 | 	*(void __percpu **)(l->key + key_size) = pptr; | 
 | } | 
 |  | 
 | static inline void __percpu *htab_elem_get_ptr(struct htab_elem *l, u32 key_size) | 
 | { | 
 | 	return *(void __percpu **)(l->key + key_size); | 
 | } | 
 |  | 
 | static void *fd_htab_map_get_ptr(const struct bpf_map *map, struct htab_elem *l) | 
 | { | 
 | 	return *(void **)(l->key + roundup(map->key_size, 8)); | 
 | } | 
 |  | 
 | static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i) | 
 | { | 
 | 	return (struct htab_elem *) (htab->elems + i * htab->elem_size); | 
 | } | 
 |  | 
 | static void htab_free_elems(struct bpf_htab *htab) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	if (!htab_is_percpu(htab)) | 
 | 		goto free_elems; | 
 |  | 
 | 	for (i = 0; i < htab->map.max_entries; i++) { | 
 | 		void __percpu *pptr; | 
 |  | 
 | 		pptr = htab_elem_get_ptr(get_htab_elem(htab, i), | 
 | 					 htab->map.key_size); | 
 | 		free_percpu(pptr); | 
 | 		cond_resched(); | 
 | 	} | 
 | free_elems: | 
 | 	bpf_map_area_free(htab->elems); | 
 | } | 
 |  | 
 | static struct htab_elem *prealloc_lru_pop(struct bpf_htab *htab, void *key, | 
 | 					  u32 hash) | 
 | { | 
 | 	struct bpf_lru_node *node = bpf_lru_pop_free(&htab->lru, hash); | 
 | 	struct htab_elem *l; | 
 |  | 
 | 	if (node) { | 
 | 		l = container_of(node, struct htab_elem, lru_node); | 
 | 		memcpy(l->key, key, htab->map.key_size); | 
 | 		return l; | 
 | 	} | 
 |  | 
 | 	return NULL; | 
 | } | 
 |  | 
 | static int prealloc_init(struct bpf_htab *htab) | 
 | { | 
 | 	u32 num_entries = htab->map.max_entries; | 
 | 	int err = -ENOMEM, i; | 
 |  | 
 | 	if (!htab_is_percpu(htab) && !htab_is_lru(htab)) | 
 | 		num_entries += num_possible_cpus(); | 
 |  | 
 | 	htab->elems = bpf_map_area_alloc(htab->elem_size * num_entries, | 
 | 					 htab->map.numa_node); | 
 | 	if (!htab->elems) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	if (!htab_is_percpu(htab)) | 
 | 		goto skip_percpu_elems; | 
 |  | 
 | 	for (i = 0; i < num_entries; i++) { | 
 | 		u32 size = round_up(htab->map.value_size, 8); | 
 | 		void __percpu *pptr; | 
 |  | 
 | 		pptr = __alloc_percpu_gfp(size, 8, GFP_USER | __GFP_NOWARN); | 
 | 		if (!pptr) | 
 | 			goto free_elems; | 
 | 		htab_elem_set_ptr(get_htab_elem(htab, i), htab->map.key_size, | 
 | 				  pptr); | 
 | 		cond_resched(); | 
 | 	} | 
 |  | 
 | skip_percpu_elems: | 
 | 	if (htab_is_lru(htab)) | 
 | 		err = bpf_lru_init(&htab->lru, | 
 | 				   htab->map.map_flags & BPF_F_NO_COMMON_LRU, | 
 | 				   offsetof(struct htab_elem, hash) - | 
 | 				   offsetof(struct htab_elem, lru_node), | 
 | 				   htab_lru_map_delete_node, | 
 | 				   htab); | 
 | 	else | 
 | 		err = pcpu_freelist_init(&htab->freelist); | 
 |  | 
 | 	if (err) | 
 | 		goto free_elems; | 
 |  | 
 | 	if (htab_is_lru(htab)) | 
 | 		bpf_lru_populate(&htab->lru, htab->elems, | 
 | 				 offsetof(struct htab_elem, lru_node), | 
 | 				 htab->elem_size, num_entries); | 
 | 	else | 
 | 		pcpu_freelist_populate(&htab->freelist, | 
 | 				       htab->elems + offsetof(struct htab_elem, fnode), | 
 | 				       htab->elem_size, num_entries); | 
 |  | 
 | 	return 0; | 
 |  | 
 | free_elems: | 
 | 	htab_free_elems(htab); | 
 | 	return err; | 
 | } | 
 |  | 
 | static void prealloc_destroy(struct bpf_htab *htab) | 
 | { | 
 | 	htab_free_elems(htab); | 
 |  | 
 | 	if (htab_is_lru(htab)) | 
 | 		bpf_lru_destroy(&htab->lru); | 
 | 	else | 
 | 		pcpu_freelist_destroy(&htab->freelist); | 
 | } | 
 |  | 
 | static int alloc_extra_elems(struct bpf_htab *htab) | 
 | { | 
 | 	struct htab_elem *__percpu *pptr, *l_new; | 
 | 	struct pcpu_freelist_node *l; | 
 | 	int cpu; | 
 |  | 
 | 	pptr = __alloc_percpu_gfp(sizeof(struct htab_elem *), 8, | 
 | 				  GFP_USER | __GFP_NOWARN); | 
 | 	if (!pptr) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	for_each_possible_cpu(cpu) { | 
 | 		l = pcpu_freelist_pop(&htab->freelist); | 
 | 		/* pop will succeed, since prealloc_init() | 
 | 		 * preallocated extra num_possible_cpus elements | 
 | 		 */ | 
 | 		l_new = container_of(l, struct htab_elem, fnode); | 
 | 		*per_cpu_ptr(pptr, cpu) = l_new; | 
 | 	} | 
 | 	htab->extra_elems = pptr; | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* Called from syscall */ | 
 | static int htab_map_alloc_check(union bpf_attr *attr) | 
 | { | 
 | 	bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH || | 
 | 		       attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH); | 
 | 	bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH || | 
 | 		    attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH); | 
 | 	/* percpu_lru means each cpu has its own LRU list. | 
 | 	 * it is different from BPF_MAP_TYPE_PERCPU_HASH where | 
 | 	 * the map's value itself is percpu.  percpu_lru has | 
 | 	 * nothing to do with the map's value. | 
 | 	 */ | 
 | 	bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU); | 
 | 	bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC); | 
 | 	bool zero_seed = (attr->map_flags & BPF_F_ZERO_SEED); | 
 | 	int numa_node = bpf_map_attr_numa_node(attr); | 
 |  | 
 | 	BUILD_BUG_ON(offsetof(struct htab_elem, htab) != | 
 | 		     offsetof(struct htab_elem, hash_node.pprev)); | 
 | 	BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) != | 
 | 		     offsetof(struct htab_elem, hash_node.pprev)); | 
 |  | 
 | 	if (lru && !capable(CAP_SYS_ADMIN)) | 
 | 		/* LRU implementation is much complicated than other | 
 | 		 * maps.  Hence, limit to CAP_SYS_ADMIN for now. | 
 | 		 */ | 
 | 		return -EPERM; | 
 |  | 
 | 	if (zero_seed && !capable(CAP_SYS_ADMIN)) | 
 | 		/* Guard against local DoS, and discourage production use. */ | 
 | 		return -EPERM; | 
 |  | 
 | 	if (attr->map_flags & ~HTAB_CREATE_FLAG_MASK || | 
 | 	    !bpf_map_flags_access_ok(attr->map_flags)) | 
 | 		return -EINVAL; | 
 |  | 
 | 	if (!lru && percpu_lru) | 
 | 		return -EINVAL; | 
 |  | 
 | 	if (lru && !prealloc) | 
 | 		return -ENOTSUPP; | 
 |  | 
 | 	if (numa_node != NUMA_NO_NODE && (percpu || percpu_lru)) | 
 | 		return -EINVAL; | 
 |  | 
 | 	/* check sanity of attributes. | 
 | 	 * value_size == 0 may be allowed in the future to use map as a set | 
 | 	 */ | 
 | 	if (attr->max_entries == 0 || attr->key_size == 0 || | 
 | 	    attr->value_size == 0) | 
 | 		return -EINVAL; | 
 |  | 
 | 	if (attr->key_size > MAX_BPF_STACK) | 
 | 		/* eBPF programs initialize keys on stack, so they cannot be | 
 | 		 * larger than max stack size | 
 | 		 */ | 
 | 		return -E2BIG; | 
 |  | 
 | 	if (attr->value_size >= KMALLOC_MAX_SIZE - | 
 | 	    MAX_BPF_STACK - sizeof(struct htab_elem)) | 
 | 		/* if value_size is bigger, the user space won't be able to | 
 | 		 * access the elements via bpf syscall. This check also makes | 
 | 		 * sure that the elem_size doesn't overflow and it's | 
 | 		 * kmalloc-able later in htab_map_update_elem() | 
 | 		 */ | 
 | 		return -E2BIG; | 
 | 	/* percpu map value size is bound by PCPU_MIN_UNIT_SIZE */ | 
 | 	if (percpu && round_up(attr->value_size, 8) > PCPU_MIN_UNIT_SIZE) | 
 | 		return -E2BIG; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static struct bpf_map *htab_map_alloc(union bpf_attr *attr) | 
 | { | 
 | 	bool percpu = (attr->map_type == BPF_MAP_TYPE_PERCPU_HASH || | 
 | 		       attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH); | 
 | 	bool lru = (attr->map_type == BPF_MAP_TYPE_LRU_HASH || | 
 | 		    attr->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH); | 
 | 	/* percpu_lru means each cpu has its own LRU list. | 
 | 	 * it is different from BPF_MAP_TYPE_PERCPU_HASH where | 
 | 	 * the map's value itself is percpu.  percpu_lru has | 
 | 	 * nothing to do with the map's value. | 
 | 	 */ | 
 | 	bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU); | 
 | 	bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC); | 
 | 	struct bpf_htab *htab; | 
 | 	int err, i; | 
 | 	u64 cost; | 
 |  | 
 | 	htab = kzalloc(sizeof(*htab), GFP_USER); | 
 | 	if (!htab) | 
 | 		return ERR_PTR(-ENOMEM); | 
 |  | 
 | 	bpf_map_init_from_attr(&htab->map, attr); | 
 |  | 
 | 	if (percpu_lru) { | 
 | 		/* ensure each CPU's lru list has >=1 elements. | 
 | 		 * since we are at it, make each lru list has the same | 
 | 		 * number of elements. | 
 | 		 */ | 
 | 		htab->map.max_entries = roundup(attr->max_entries, | 
 | 						num_possible_cpus()); | 
 | 		if (htab->map.max_entries < attr->max_entries) | 
 | 			htab->map.max_entries = rounddown(attr->max_entries, | 
 | 							  num_possible_cpus()); | 
 | 	} | 
 |  | 
 | 	/* hash table size must be power of 2; roundup_pow_of_two() can overflow | 
 | 	 * into UB on 32-bit arches, so check that first | 
 | 	 */ | 
 | 	err = -E2BIG; | 
 | 	if (htab->map.max_entries > 1UL << 31) | 
 | 		goto free_htab; | 
 |  | 
 | 	htab->n_buckets = roundup_pow_of_two(htab->map.max_entries); | 
 |  | 
 | 	htab->elem_size = sizeof(struct htab_elem) + | 
 | 			  round_up(htab->map.key_size, 8); | 
 | 	if (percpu) | 
 | 		htab->elem_size += sizeof(void *); | 
 | 	else | 
 | 		htab->elem_size += round_up(htab->map.value_size, 8); | 
 |  | 
 | 	/* check for u32 overflow */ | 
 | 	if (htab->n_buckets > U32_MAX / sizeof(struct bucket)) | 
 | 		goto free_htab; | 
 |  | 
 | 	cost = (u64) htab->n_buckets * sizeof(struct bucket) + | 
 | 	       (u64) htab->elem_size * htab->map.max_entries; | 
 |  | 
 | 	if (percpu) | 
 | 		cost += (u64) round_up(htab->map.value_size, 8) * | 
 | 			num_possible_cpus() * htab->map.max_entries; | 
 | 	else | 
 | 	       cost += (u64) htab->elem_size * num_possible_cpus(); | 
 |  | 
 | 	/* if map size is larger than memlock limit, reject it */ | 
 | 	err = bpf_map_charge_init(&htab->map.memory, cost); | 
 | 	if (err) | 
 | 		goto free_htab; | 
 |  | 
 | 	err = -ENOMEM; | 
 | 	htab->buckets = bpf_map_area_alloc(htab->n_buckets * | 
 | 					   sizeof(struct bucket), | 
 | 					   htab->map.numa_node); | 
 | 	if (!htab->buckets) | 
 | 		goto free_charge; | 
 |  | 
 | 	if (htab->map.map_flags & BPF_F_ZERO_SEED) | 
 | 		htab->hashrnd = 0; | 
 | 	else | 
 | 		htab->hashrnd = get_random_int(); | 
 |  | 
 | 	for (i = 0; i < htab->n_buckets; i++) { | 
 | 		INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i); | 
 | 		raw_spin_lock_init(&htab->buckets[i].lock); | 
 | 	} | 
 |  | 
 | 	if (prealloc) { | 
 | 		err = prealloc_init(htab); | 
 | 		if (err) | 
 | 			goto free_buckets; | 
 |  | 
 | 		if (!percpu && !lru) { | 
 | 			/* lru itself can remove the least used element, so | 
 | 			 * there is no need for an extra elem during map_update. | 
 | 			 */ | 
 | 			err = alloc_extra_elems(htab); | 
 | 			if (err) | 
 | 				goto free_prealloc; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	return &htab->map; | 
 |  | 
 | free_prealloc: | 
 | 	prealloc_destroy(htab); | 
 | free_buckets: | 
 | 	bpf_map_area_free(htab->buckets); | 
 | free_charge: | 
 | 	bpf_map_charge_finish(&htab->map.memory); | 
 | free_htab: | 
 | 	kfree(htab); | 
 | 	return ERR_PTR(err); | 
 | } | 
 |  | 
 | static inline u32 htab_map_hash(const void *key, u32 key_len, u32 hashrnd) | 
 | { | 
 | 	return jhash(key, key_len, hashrnd); | 
 | } | 
 |  | 
 | static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash) | 
 | { | 
 | 	return &htab->buckets[hash & (htab->n_buckets - 1)]; | 
 | } | 
 |  | 
 | static inline struct hlist_nulls_head *select_bucket(struct bpf_htab *htab, u32 hash) | 
 | { | 
 | 	return &__select_bucket(htab, hash)->head; | 
 | } | 
 |  | 
 | /* this lookup function can only be called with bucket lock taken */ | 
 | static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash, | 
 | 					 void *key, u32 key_size) | 
 | { | 
 | 	struct hlist_nulls_node *n; | 
 | 	struct htab_elem *l; | 
 |  | 
 | 	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node) | 
 | 		if (l->hash == hash && !memcmp(&l->key, key, key_size)) | 
 | 			return l; | 
 |  | 
 | 	return NULL; | 
 | } | 
 |  | 
 | /* can be called without bucket lock. it will repeat the loop in | 
 |  * the unlikely event when elements moved from one bucket into another | 
 |  * while link list is being walked | 
 |  */ | 
 | static struct htab_elem *lookup_nulls_elem_raw(struct hlist_nulls_head *head, | 
 | 					       u32 hash, void *key, | 
 | 					       u32 key_size, u32 n_buckets) | 
 | { | 
 | 	struct hlist_nulls_node *n; | 
 | 	struct htab_elem *l; | 
 |  | 
 | again: | 
 | 	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node) | 
 | 		if (l->hash == hash && !memcmp(&l->key, key, key_size)) | 
 | 			return l; | 
 |  | 
 | 	if (unlikely(get_nulls_value(n) != (hash & (n_buckets - 1)))) | 
 | 		goto again; | 
 |  | 
 | 	return NULL; | 
 | } | 
 |  | 
 | /* Called from syscall or from eBPF program directly, so | 
 |  * arguments have to match bpf_map_lookup_elem() exactly. | 
 |  * The return value is adjusted by BPF instructions | 
 |  * in htab_map_gen_lookup(). | 
 |  */ | 
 | static void *__htab_map_lookup_elem(struct bpf_map *map, void *key) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct hlist_nulls_head *head; | 
 | 	struct htab_elem *l; | 
 | 	u32 hash, key_size; | 
 |  | 
 | 	/* Must be called with rcu_read_lock. */ | 
 | 	WARN_ON_ONCE(!rcu_read_lock_held()); | 
 |  | 
 | 	key_size = map->key_size; | 
 |  | 
 | 	hash = htab_map_hash(key, key_size, htab->hashrnd); | 
 |  | 
 | 	head = select_bucket(htab, hash); | 
 |  | 
 | 	l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets); | 
 |  | 
 | 	return l; | 
 | } | 
 |  | 
 | static void *htab_map_lookup_elem(struct bpf_map *map, void *key) | 
 | { | 
 | 	struct htab_elem *l = __htab_map_lookup_elem(map, key); | 
 |  | 
 | 	if (l) | 
 | 		return l->key + round_up(map->key_size, 8); | 
 |  | 
 | 	return NULL; | 
 | } | 
 |  | 
 | /* inline bpf_map_lookup_elem() call. | 
 |  * Instead of: | 
 |  * bpf_prog | 
 |  *   bpf_map_lookup_elem | 
 |  *     map->ops->map_lookup_elem | 
 |  *       htab_map_lookup_elem | 
 |  *         __htab_map_lookup_elem | 
 |  * do: | 
 |  * bpf_prog | 
 |  *   __htab_map_lookup_elem | 
 |  */ | 
 | static u32 htab_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) | 
 | { | 
 | 	struct bpf_insn *insn = insn_buf; | 
 | 	const int ret = BPF_REG_0; | 
 |  | 
 | 	BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem, | 
 | 		     (void *(*)(struct bpf_map *map, void *key))NULL)); | 
 | 	*insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem)); | 
 | 	*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 1); | 
 | 	*insn++ = BPF_ALU64_IMM(BPF_ADD, ret, | 
 | 				offsetof(struct htab_elem, key) + | 
 | 				round_up(map->key_size, 8)); | 
 | 	return insn - insn_buf; | 
 | } | 
 |  | 
 | static __always_inline void *__htab_lru_map_lookup_elem(struct bpf_map *map, | 
 | 							void *key, const bool mark) | 
 | { | 
 | 	struct htab_elem *l = __htab_map_lookup_elem(map, key); | 
 |  | 
 | 	if (l) { | 
 | 		if (mark) | 
 | 			bpf_lru_node_set_ref(&l->lru_node); | 
 | 		return l->key + round_up(map->key_size, 8); | 
 | 	} | 
 |  | 
 | 	return NULL; | 
 | } | 
 |  | 
 | static void *htab_lru_map_lookup_elem(struct bpf_map *map, void *key) | 
 | { | 
 | 	return __htab_lru_map_lookup_elem(map, key, true); | 
 | } | 
 |  | 
 | static void *htab_lru_map_lookup_elem_sys(struct bpf_map *map, void *key) | 
 | { | 
 | 	return __htab_lru_map_lookup_elem(map, key, false); | 
 | } | 
 |  | 
 | static u32 htab_lru_map_gen_lookup(struct bpf_map *map, | 
 | 				   struct bpf_insn *insn_buf) | 
 | { | 
 | 	struct bpf_insn *insn = insn_buf; | 
 | 	const int ret = BPF_REG_0; | 
 | 	const int ref_reg = BPF_REG_1; | 
 |  | 
 | 	BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem, | 
 | 		     (void *(*)(struct bpf_map *map, void *key))NULL)); | 
 | 	*insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem)); | 
 | 	*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 4); | 
 | 	*insn++ = BPF_LDX_MEM(BPF_B, ref_reg, ret, | 
 | 			      offsetof(struct htab_elem, lru_node) + | 
 | 			      offsetof(struct bpf_lru_node, ref)); | 
 | 	*insn++ = BPF_JMP_IMM(BPF_JNE, ref_reg, 0, 1); | 
 | 	*insn++ = BPF_ST_MEM(BPF_B, ret, | 
 | 			     offsetof(struct htab_elem, lru_node) + | 
 | 			     offsetof(struct bpf_lru_node, ref), | 
 | 			     1); | 
 | 	*insn++ = BPF_ALU64_IMM(BPF_ADD, ret, | 
 | 				offsetof(struct htab_elem, key) + | 
 | 				round_up(map->key_size, 8)); | 
 | 	return insn - insn_buf; | 
 | } | 
 |  | 
 | /* It is called from the bpf_lru_list when the LRU needs to delete | 
 |  * older elements from the htab. | 
 |  */ | 
 | static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) | 
 | { | 
 | 	struct bpf_htab *htab = (struct bpf_htab *)arg; | 
 | 	struct htab_elem *l = NULL, *tgt_l; | 
 | 	struct hlist_nulls_head *head; | 
 | 	struct hlist_nulls_node *n; | 
 | 	unsigned long flags; | 
 | 	struct bucket *b; | 
 |  | 
 | 	tgt_l = container_of(node, struct htab_elem, lru_node); | 
 | 	b = __select_bucket(htab, tgt_l->hash); | 
 | 	head = &b->head; | 
 |  | 
 | 	raw_spin_lock_irqsave(&b->lock, flags); | 
 |  | 
 | 	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node) | 
 | 		if (l == tgt_l) { | 
 | 			hlist_nulls_del_rcu(&l->hash_node); | 
 | 			break; | 
 | 		} | 
 |  | 
 | 	raw_spin_unlock_irqrestore(&b->lock, flags); | 
 |  | 
 | 	return l == tgt_l; | 
 | } | 
 |  | 
 | /* Called from syscall */ | 
 | static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct hlist_nulls_head *head; | 
 | 	struct htab_elem *l, *next_l; | 
 | 	u32 hash, key_size; | 
 | 	int i = 0; | 
 |  | 
 | 	WARN_ON_ONCE(!rcu_read_lock_held()); | 
 |  | 
 | 	key_size = map->key_size; | 
 |  | 
 | 	if (!key) | 
 | 		goto find_first_elem; | 
 |  | 
 | 	hash = htab_map_hash(key, key_size, htab->hashrnd); | 
 |  | 
 | 	head = select_bucket(htab, hash); | 
 |  | 
 | 	/* lookup the key */ | 
 | 	l = lookup_nulls_elem_raw(head, hash, key, key_size, htab->n_buckets); | 
 |  | 
 | 	if (!l) | 
 | 		goto find_first_elem; | 
 |  | 
 | 	/* key was found, get next key in the same bucket */ | 
 | 	next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_next_rcu(&l->hash_node)), | 
 | 				  struct htab_elem, hash_node); | 
 |  | 
 | 	if (next_l) { | 
 | 		/* if next elem in this hash list is non-zero, just return it */ | 
 | 		memcpy(next_key, next_l->key, key_size); | 
 | 		return 0; | 
 | 	} | 
 |  | 
 | 	/* no more elements in this hash list, go to the next bucket */ | 
 | 	i = hash & (htab->n_buckets - 1); | 
 | 	i++; | 
 |  | 
 | find_first_elem: | 
 | 	/* iterate over buckets */ | 
 | 	for (; i < htab->n_buckets; i++) { | 
 | 		head = select_bucket(htab, i); | 
 |  | 
 | 		/* pick first element in the bucket */ | 
 | 		next_l = hlist_nulls_entry_safe(rcu_dereference_raw(hlist_nulls_first_rcu(head)), | 
 | 					  struct htab_elem, hash_node); | 
 | 		if (next_l) { | 
 | 			/* if it's not empty, just return it */ | 
 | 			memcpy(next_key, next_l->key, key_size); | 
 | 			return 0; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	/* iterated over all buckets and all elements */ | 
 | 	return -ENOENT; | 
 | } | 
 |  | 
 | static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l) | 
 | { | 
 | 	if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH) | 
 | 		free_percpu(htab_elem_get_ptr(l, htab->map.key_size)); | 
 | 	kfree(l); | 
 | } | 
 |  | 
 | static void htab_elem_free_rcu(struct rcu_head *head) | 
 | { | 
 | 	struct htab_elem *l = container_of(head, struct htab_elem, rcu); | 
 | 	struct bpf_htab *htab = l->htab; | 
 |  | 
 | 	htab_elem_free(htab, l); | 
 | } | 
 |  | 
 | static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l) | 
 | { | 
 | 	struct bpf_map *map = &htab->map; | 
 | 	void *ptr; | 
 |  | 
 | 	if (map->ops->map_fd_put_ptr) { | 
 | 		ptr = fd_htab_map_get_ptr(map, l); | 
 | 		map->ops->map_fd_put_ptr(map, ptr, true); | 
 | 	} | 
 | } | 
 |  | 
 | static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) | 
 | { | 
 | 	htab_put_fd_value(htab, l); | 
 |  | 
 | 	if (htab_is_prealloc(htab)) { | 
 | 		__pcpu_freelist_push(&htab->freelist, &l->fnode); | 
 | 	} else { | 
 | 		atomic_dec(&htab->count); | 
 | 		l->htab = htab; | 
 | 		call_rcu(&l->rcu, htab_elem_free_rcu); | 
 | 	} | 
 | } | 
 |  | 
 | static void pcpu_copy_value(struct bpf_htab *htab, void __percpu *pptr, | 
 | 			    void *value, bool onallcpus) | 
 | { | 
 | 	if (!onallcpus) { | 
 | 		/* copy true value_size bytes */ | 
 | 		memcpy(this_cpu_ptr(pptr), value, htab->map.value_size); | 
 | 	} else { | 
 | 		u32 size = round_up(htab->map.value_size, 8); | 
 | 		int off = 0, cpu; | 
 |  | 
 | 		for_each_possible_cpu(cpu) { | 
 | 			bpf_long_memcpy(per_cpu_ptr(pptr, cpu), | 
 | 					value + off, size); | 
 | 			off += size; | 
 | 		} | 
 | 	} | 
 | } | 
 |  | 
 | static void pcpu_init_value(struct bpf_htab *htab, void __percpu *pptr, | 
 | 			    void *value, bool onallcpus) | 
 | { | 
 | 	/* When using prealloc and not setting the initial value on all cpus, | 
 | 	 * zero-fill element values for other cpus (just as what happens when | 
 | 	 * not using prealloc). Otherwise, bpf program has no way to ensure | 
 | 	 * known initial values for cpus other than current one | 
 | 	 * (onallcpus=false always when coming from bpf prog). | 
 | 	 */ | 
 | 	if (htab_is_prealloc(htab) && !onallcpus) { | 
 | 		u32 size = round_up(htab->map.value_size, 8); | 
 | 		int current_cpu = raw_smp_processor_id(); | 
 | 		int cpu; | 
 |  | 
 | 		for_each_possible_cpu(cpu) { | 
 | 			if (cpu == current_cpu) | 
 | 				bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value, | 
 | 						size); | 
 | 			else | 
 | 				memset(per_cpu_ptr(pptr, cpu), 0, size); | 
 | 		} | 
 | 	} else { | 
 | 		pcpu_copy_value(htab, pptr, value, onallcpus); | 
 | 	} | 
 | } | 
 |  | 
 | static bool fd_htab_map_needs_adjust(const struct bpf_htab *htab) | 
 | { | 
 | 	return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS && | 
 | 	       BITS_PER_LONG == 64; | 
 | } | 
 |  | 
 | static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key, | 
 | 					 void *value, u32 key_size, u32 hash, | 
 | 					 bool percpu, bool onallcpus, | 
 | 					 struct htab_elem *old_elem) | 
 | { | 
 | 	u32 size = htab->map.value_size; | 
 | 	bool prealloc = htab_is_prealloc(htab); | 
 | 	struct htab_elem *l_new, **pl_new; | 
 | 	void __percpu *pptr; | 
 |  | 
 | 	if (prealloc) { | 
 | 		if (old_elem) { | 
 | 			/* if we're updating the existing element, | 
 | 			 * use per-cpu extra elems to avoid freelist_pop/push | 
 | 			 */ | 
 | 			pl_new = this_cpu_ptr(htab->extra_elems); | 
 | 			l_new = *pl_new; | 
 | 			htab_put_fd_value(htab, old_elem); | 
 | 			*pl_new = old_elem; | 
 | 		} else { | 
 | 			struct pcpu_freelist_node *l; | 
 |  | 
 | 			l = __pcpu_freelist_pop(&htab->freelist); | 
 | 			if (!l) | 
 | 				return ERR_PTR(-E2BIG); | 
 | 			l_new = container_of(l, struct htab_elem, fnode); | 
 | 		} | 
 | 	} else { | 
 | 		if (atomic_inc_return(&htab->count) > htab->map.max_entries) | 
 | 			if (!old_elem) { | 
 | 				/* when map is full and update() is replacing | 
 | 				 * old element, it's ok to allocate, since | 
 | 				 * old element will be freed immediately. | 
 | 				 * Otherwise return an error | 
 | 				 */ | 
 | 				l_new = ERR_PTR(-E2BIG); | 
 | 				goto dec_count; | 
 | 			} | 
 | 		l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN, | 
 | 				     htab->map.numa_node); | 
 | 		if (!l_new) { | 
 | 			l_new = ERR_PTR(-ENOMEM); | 
 | 			goto dec_count; | 
 | 		} | 
 | 		check_and_init_map_lock(&htab->map, | 
 | 					l_new->key + round_up(key_size, 8)); | 
 | 	} | 
 |  | 
 | 	memcpy(l_new->key, key, key_size); | 
 | 	if (percpu) { | 
 | 		size = round_up(size, 8); | 
 | 		if (prealloc) { | 
 | 			pptr = htab_elem_get_ptr(l_new, key_size); | 
 | 		} else { | 
 | 			/* alloc_percpu zero-fills */ | 
 | 			pptr = __alloc_percpu_gfp(size, 8, | 
 | 						  GFP_ATOMIC | __GFP_NOWARN); | 
 | 			if (!pptr) { | 
 | 				kfree(l_new); | 
 | 				l_new = ERR_PTR(-ENOMEM); | 
 | 				goto dec_count; | 
 | 			} | 
 | 		} | 
 |  | 
 | 		pcpu_init_value(htab, pptr, value, onallcpus); | 
 |  | 
 | 		if (!prealloc) | 
 | 			htab_elem_set_ptr(l_new, key_size, pptr); | 
 | 	} else if (fd_htab_map_needs_adjust(htab)) { | 
 | 		size = round_up(size, 8); | 
 | 		memcpy(l_new->key + round_up(key_size, 8), value, size); | 
 | 	} else { | 
 | 		copy_map_value(&htab->map, | 
 | 			       l_new->key + round_up(key_size, 8), | 
 | 			       value); | 
 | 	} | 
 |  | 
 | 	l_new->hash = hash; | 
 | 	return l_new; | 
 | dec_count: | 
 | 	atomic_dec(&htab->count); | 
 | 	return l_new; | 
 | } | 
 |  | 
 | static int check_flags(struct bpf_htab *htab, struct htab_elem *l_old, | 
 | 		       u64 map_flags) | 
 | { | 
 | 	if (l_old && (map_flags & ~BPF_F_LOCK) == BPF_NOEXIST) | 
 | 		/* elem already exists */ | 
 | 		return -EEXIST; | 
 |  | 
 | 	if (!l_old && (map_flags & ~BPF_F_LOCK) == BPF_EXIST) | 
 | 		/* elem doesn't exist, cannot update it */ | 
 | 		return -ENOENT; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | /* Called from syscall or from eBPF program */ | 
 | static int htab_map_update_elem(struct bpf_map *map, void *key, void *value, | 
 | 				u64 map_flags) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct htab_elem *l_new = NULL, *l_old; | 
 | 	struct hlist_nulls_head *head; | 
 | 	unsigned long flags; | 
 | 	struct bucket *b; | 
 | 	u32 key_size, hash; | 
 | 	int ret; | 
 |  | 
 | 	if (unlikely((map_flags & ~BPF_F_LOCK) > BPF_EXIST)) | 
 | 		/* unknown flags */ | 
 | 		return -EINVAL; | 
 |  | 
 | 	WARN_ON_ONCE(!rcu_read_lock_held()); | 
 |  | 
 | 	key_size = map->key_size; | 
 |  | 
 | 	hash = htab_map_hash(key, key_size, htab->hashrnd); | 
 |  | 
 | 	b = __select_bucket(htab, hash); | 
 | 	head = &b->head; | 
 |  | 
 | 	if (unlikely(map_flags & BPF_F_LOCK)) { | 
 | 		if (unlikely(!map_value_has_spin_lock(map))) | 
 | 			return -EINVAL; | 
 | 		/* find an element without taking the bucket lock */ | 
 | 		l_old = lookup_nulls_elem_raw(head, hash, key, key_size, | 
 | 					      htab->n_buckets); | 
 | 		ret = check_flags(htab, l_old, map_flags); | 
 | 		if (ret) | 
 | 			return ret; | 
 | 		if (l_old) { | 
 | 			/* grab the element lock and update value in place */ | 
 | 			copy_map_value_locked(map, | 
 | 					      l_old->key + round_up(key_size, 8), | 
 | 					      value, false); | 
 | 			return 0; | 
 | 		} | 
 | 		/* fall through, grab the bucket lock and lookup again. | 
 | 		 * 99.9% chance that the element won't be found, | 
 | 		 * but second lookup under lock has to be done. | 
 | 		 */ | 
 | 	} | 
 |  | 
 | 	/* bpf_map_update_elem() can be called in_irq() */ | 
 | 	raw_spin_lock_irqsave(&b->lock, flags); | 
 |  | 
 | 	l_old = lookup_elem_raw(head, hash, key, key_size); | 
 |  | 
 | 	ret = check_flags(htab, l_old, map_flags); | 
 | 	if (ret) | 
 | 		goto err; | 
 |  | 
 | 	if (unlikely(l_old && (map_flags & BPF_F_LOCK))) { | 
 | 		/* first lookup without the bucket lock didn't find the element, | 
 | 		 * but second lookup with the bucket lock found it. | 
 | 		 * This case is highly unlikely, but has to be dealt with: | 
 | 		 * grab the element lock in addition to the bucket lock | 
 | 		 * and update element in place | 
 | 		 */ | 
 | 		copy_map_value_locked(map, | 
 | 				      l_old->key + round_up(key_size, 8), | 
 | 				      value, false); | 
 | 		ret = 0; | 
 | 		goto err; | 
 | 	} | 
 |  | 
 | 	l_new = alloc_htab_elem(htab, key, value, key_size, hash, false, false, | 
 | 				l_old); | 
 | 	if (IS_ERR(l_new)) { | 
 | 		/* all pre-allocated elements are in use or memory exhausted */ | 
 | 		ret = PTR_ERR(l_new); | 
 | 		goto err; | 
 | 	} | 
 |  | 
 | 	/* add new element to the head of the list, so that | 
 | 	 * concurrent search will find it before old elem | 
 | 	 */ | 
 | 	hlist_nulls_add_head_rcu(&l_new->hash_node, head); | 
 | 	if (l_old) { | 
 | 		hlist_nulls_del_rcu(&l_old->hash_node); | 
 | 		if (!htab_is_prealloc(htab)) | 
 | 			free_htab_elem(htab, l_old); | 
 | 	} | 
 | 	ret = 0; | 
 | err: | 
 | 	raw_spin_unlock_irqrestore(&b->lock, flags); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value, | 
 | 				    u64 map_flags) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct htab_elem *l_new, *l_old = NULL; | 
 | 	struct hlist_nulls_head *head; | 
 | 	unsigned long flags; | 
 | 	struct bucket *b; | 
 | 	u32 key_size, hash; | 
 | 	int ret; | 
 |  | 
 | 	if (unlikely(map_flags > BPF_EXIST)) | 
 | 		/* unknown flags */ | 
 | 		return -EINVAL; | 
 |  | 
 | 	WARN_ON_ONCE(!rcu_read_lock_held()); | 
 |  | 
 | 	key_size = map->key_size; | 
 |  | 
 | 	hash = htab_map_hash(key, key_size, htab->hashrnd); | 
 |  | 
 | 	b = __select_bucket(htab, hash); | 
 | 	head = &b->head; | 
 |  | 
 | 	/* For LRU, we need to alloc before taking bucket's | 
 | 	 * spinlock because getting free nodes from LRU may need | 
 | 	 * to remove older elements from htab and this removal | 
 | 	 * operation will need a bucket lock. | 
 | 	 */ | 
 | 	l_new = prealloc_lru_pop(htab, key, hash); | 
 | 	if (!l_new) | 
 | 		return -ENOMEM; | 
 | 	memcpy(l_new->key + round_up(map->key_size, 8), value, map->value_size); | 
 |  | 
 | 	/* bpf_map_update_elem() can be called in_irq() */ | 
 | 	raw_spin_lock_irqsave(&b->lock, flags); | 
 |  | 
 | 	l_old = lookup_elem_raw(head, hash, key, key_size); | 
 |  | 
 | 	ret = check_flags(htab, l_old, map_flags); | 
 | 	if (ret) | 
 | 		goto err; | 
 |  | 
 | 	/* add new element to the head of the list, so that | 
 | 	 * concurrent search will find it before old elem | 
 | 	 */ | 
 | 	hlist_nulls_add_head_rcu(&l_new->hash_node, head); | 
 | 	if (l_old) { | 
 | 		bpf_lru_node_set_ref(&l_new->lru_node); | 
 | 		hlist_nulls_del_rcu(&l_old->hash_node); | 
 | 	} | 
 | 	ret = 0; | 
 |  | 
 | err: | 
 | 	raw_spin_unlock_irqrestore(&b->lock, flags); | 
 |  | 
 | 	if (ret) | 
 | 		bpf_lru_push_free(&htab->lru, &l_new->lru_node); | 
 | 	else if (l_old) | 
 | 		bpf_lru_push_free(&htab->lru, &l_old->lru_node); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key, | 
 | 					 void *value, u64 map_flags, | 
 | 					 bool onallcpus) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct htab_elem *l_new = NULL, *l_old; | 
 | 	struct hlist_nulls_head *head; | 
 | 	unsigned long flags; | 
 | 	struct bucket *b; | 
 | 	u32 key_size, hash; | 
 | 	int ret; | 
 |  | 
 | 	if (unlikely(map_flags > BPF_EXIST)) | 
 | 		/* unknown flags */ | 
 | 		return -EINVAL; | 
 |  | 
 | 	WARN_ON_ONCE(!rcu_read_lock_held()); | 
 |  | 
 | 	key_size = map->key_size; | 
 |  | 
 | 	hash = htab_map_hash(key, key_size, htab->hashrnd); | 
 |  | 
 | 	b = __select_bucket(htab, hash); | 
 | 	head = &b->head; | 
 |  | 
 | 	/* bpf_map_update_elem() can be called in_irq() */ | 
 | 	raw_spin_lock_irqsave(&b->lock, flags); | 
 |  | 
 | 	l_old = lookup_elem_raw(head, hash, key, key_size); | 
 |  | 
 | 	ret = check_flags(htab, l_old, map_flags); | 
 | 	if (ret) | 
 | 		goto err; | 
 |  | 
 | 	if (l_old) { | 
 | 		/* per-cpu hash map can update value in-place */ | 
 | 		pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size), | 
 | 				value, onallcpus); | 
 | 	} else { | 
 | 		l_new = alloc_htab_elem(htab, key, value, key_size, | 
 | 					hash, true, onallcpus, NULL); | 
 | 		if (IS_ERR(l_new)) { | 
 | 			ret = PTR_ERR(l_new); | 
 | 			goto err; | 
 | 		} | 
 | 		hlist_nulls_add_head_rcu(&l_new->hash_node, head); | 
 | 	} | 
 | 	ret = 0; | 
 | err: | 
 | 	raw_spin_unlock_irqrestore(&b->lock, flags); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, | 
 | 					     void *value, u64 map_flags, | 
 | 					     bool onallcpus) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct htab_elem *l_new = NULL, *l_old; | 
 | 	struct hlist_nulls_head *head; | 
 | 	unsigned long flags; | 
 | 	struct bucket *b; | 
 | 	u32 key_size, hash; | 
 | 	int ret; | 
 |  | 
 | 	if (unlikely(map_flags > BPF_EXIST)) | 
 | 		/* unknown flags */ | 
 | 		return -EINVAL; | 
 |  | 
 | 	WARN_ON_ONCE(!rcu_read_lock_held()); | 
 |  | 
 | 	key_size = map->key_size; | 
 |  | 
 | 	hash = htab_map_hash(key, key_size, htab->hashrnd); | 
 |  | 
 | 	b = __select_bucket(htab, hash); | 
 | 	head = &b->head; | 
 |  | 
 | 	/* For LRU, we need to alloc before taking bucket's | 
 | 	 * spinlock because LRU's elem alloc may need | 
 | 	 * to remove older elem from htab and this removal | 
 | 	 * operation will need a bucket lock. | 
 | 	 */ | 
 | 	if (map_flags != BPF_EXIST) { | 
 | 		l_new = prealloc_lru_pop(htab, key, hash); | 
 | 		if (!l_new) | 
 | 			return -ENOMEM; | 
 | 	} | 
 |  | 
 | 	/* bpf_map_update_elem() can be called in_irq() */ | 
 | 	raw_spin_lock_irqsave(&b->lock, flags); | 
 |  | 
 | 	l_old = lookup_elem_raw(head, hash, key, key_size); | 
 |  | 
 | 	ret = check_flags(htab, l_old, map_flags); | 
 | 	if (ret) | 
 | 		goto err; | 
 |  | 
 | 	if (l_old) { | 
 | 		bpf_lru_node_set_ref(&l_old->lru_node); | 
 |  | 
 | 		/* per-cpu hash map can update value in-place */ | 
 | 		pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size), | 
 | 				value, onallcpus); | 
 | 	} else { | 
 | 		pcpu_init_value(htab, htab_elem_get_ptr(l_new, key_size), | 
 | 				value, onallcpus); | 
 | 		hlist_nulls_add_head_rcu(&l_new->hash_node, head); | 
 | 		l_new = NULL; | 
 | 	} | 
 | 	ret = 0; | 
 | err: | 
 | 	raw_spin_unlock_irqrestore(&b->lock, flags); | 
 | 	if (l_new) | 
 | 		bpf_lru_push_free(&htab->lru, &l_new->lru_node); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int htab_percpu_map_update_elem(struct bpf_map *map, void *key, | 
 | 				       void *value, u64 map_flags) | 
 | { | 
 | 	return __htab_percpu_map_update_elem(map, key, value, map_flags, false); | 
 | } | 
 |  | 
 | static int htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, | 
 | 					   void *value, u64 map_flags) | 
 | { | 
 | 	return __htab_lru_percpu_map_update_elem(map, key, value, map_flags, | 
 | 						 false); | 
 | } | 
 |  | 
 | /* Called from syscall or from eBPF program */ | 
 | static int htab_map_delete_elem(struct bpf_map *map, void *key) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct hlist_nulls_head *head; | 
 | 	struct bucket *b; | 
 | 	struct htab_elem *l; | 
 | 	unsigned long flags; | 
 | 	u32 hash, key_size; | 
 | 	int ret = -ENOENT; | 
 |  | 
 | 	WARN_ON_ONCE(!rcu_read_lock_held()); | 
 |  | 
 | 	key_size = map->key_size; | 
 |  | 
 | 	hash = htab_map_hash(key, key_size, htab->hashrnd); | 
 | 	b = __select_bucket(htab, hash); | 
 | 	head = &b->head; | 
 |  | 
 | 	raw_spin_lock_irqsave(&b->lock, flags); | 
 |  | 
 | 	l = lookup_elem_raw(head, hash, key, key_size); | 
 |  | 
 | 	if (l) { | 
 | 		hlist_nulls_del_rcu(&l->hash_node); | 
 | 		free_htab_elem(htab, l); | 
 | 		ret = 0; | 
 | 	} | 
 |  | 
 | 	raw_spin_unlock_irqrestore(&b->lock, flags); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int htab_lru_map_delete_elem(struct bpf_map *map, void *key) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct hlist_nulls_head *head; | 
 | 	struct bucket *b; | 
 | 	struct htab_elem *l; | 
 | 	unsigned long flags; | 
 | 	u32 hash, key_size; | 
 | 	int ret = -ENOENT; | 
 |  | 
 | 	WARN_ON_ONCE(!rcu_read_lock_held()); | 
 |  | 
 | 	key_size = map->key_size; | 
 |  | 
 | 	hash = htab_map_hash(key, key_size, htab->hashrnd); | 
 | 	b = __select_bucket(htab, hash); | 
 | 	head = &b->head; | 
 |  | 
 | 	raw_spin_lock_irqsave(&b->lock, flags); | 
 |  | 
 | 	l = lookup_elem_raw(head, hash, key, key_size); | 
 |  | 
 | 	if (l) { | 
 | 		hlist_nulls_del_rcu(&l->hash_node); | 
 | 		ret = 0; | 
 | 	} | 
 |  | 
 | 	raw_spin_unlock_irqrestore(&b->lock, flags); | 
 | 	if (l) | 
 | 		bpf_lru_push_free(&htab->lru, &l->lru_node); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static void delete_all_elements(struct bpf_htab *htab) | 
 | { | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < htab->n_buckets; i++) { | 
 | 		struct hlist_nulls_head *head = select_bucket(htab, i); | 
 | 		struct hlist_nulls_node *n; | 
 | 		struct htab_elem *l; | 
 |  | 
 | 		hlist_nulls_for_each_entry_safe(l, n, head, hash_node) { | 
 | 			hlist_nulls_del_rcu(&l->hash_node); | 
 | 			htab_elem_free(htab, l); | 
 | 		} | 
 | 	} | 
 | } | 
 |  | 
 | /* Called when map->refcnt goes to zero, either from workqueue or from syscall */ | 
 | static void htab_map_free(struct bpf_map *map) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 |  | 
 | 	/* at this point bpf_prog->aux->refcnt == 0 and this map->refcnt == 0, | 
 | 	 * so the programs (can be more than one that used this map) were | 
 | 	 * disconnected from events. Wait for outstanding critical sections in | 
 | 	 * these programs to complete | 
 | 	 */ | 
 | 	synchronize_rcu(); | 
 |  | 
 | 	/* some of free_htab_elem() callbacks for elements of this map may | 
 | 	 * not have executed. Wait for them. | 
 | 	 */ | 
 | 	rcu_barrier(); | 
 | 	if (!htab_is_prealloc(htab)) | 
 | 		delete_all_elements(htab); | 
 | 	else | 
 | 		prealloc_destroy(htab); | 
 |  | 
 | 	free_percpu(htab->extra_elems); | 
 | 	bpf_map_area_free(htab->buckets); | 
 | 	kfree(htab); | 
 | } | 
 |  | 
 | static void htab_map_seq_show_elem(struct bpf_map *map, void *key, | 
 | 				   struct seq_file *m) | 
 | { | 
 | 	void *value; | 
 |  | 
 | 	rcu_read_lock(); | 
 |  | 
 | 	value = htab_map_lookup_elem(map, key); | 
 | 	if (!value) { | 
 | 		rcu_read_unlock(); | 
 | 		return; | 
 | 	} | 
 |  | 
 | 	btf_type_seq_show(map->btf, map->btf_key_type_id, key, m); | 
 | 	seq_puts(m, ": "); | 
 | 	btf_type_seq_show(map->btf, map->btf_value_type_id, value, m); | 
 | 	seq_puts(m, "\n"); | 
 |  | 
 | 	rcu_read_unlock(); | 
 | } | 
 |  | 
 | const struct bpf_map_ops htab_map_ops = { | 
 | 	.map_alloc_check = htab_map_alloc_check, | 
 | 	.map_alloc = htab_map_alloc, | 
 | 	.map_free = htab_map_free, | 
 | 	.map_get_next_key = htab_map_get_next_key, | 
 | 	.map_lookup_elem = htab_map_lookup_elem, | 
 | 	.map_update_elem = htab_map_update_elem, | 
 | 	.map_delete_elem = htab_map_delete_elem, | 
 | 	.map_gen_lookup = htab_map_gen_lookup, | 
 | 	.map_seq_show_elem = htab_map_seq_show_elem, | 
 | }; | 
 |  | 
 | const struct bpf_map_ops htab_lru_map_ops = { | 
 | 	.map_alloc_check = htab_map_alloc_check, | 
 | 	.map_alloc = htab_map_alloc, | 
 | 	.map_free = htab_map_free, | 
 | 	.map_get_next_key = htab_map_get_next_key, | 
 | 	.map_lookup_elem = htab_lru_map_lookup_elem, | 
 | 	.map_lookup_elem_sys_only = htab_lru_map_lookup_elem_sys, | 
 | 	.map_update_elem = htab_lru_map_update_elem, | 
 | 	.map_delete_elem = htab_lru_map_delete_elem, | 
 | 	.map_gen_lookup = htab_lru_map_gen_lookup, | 
 | 	.map_seq_show_elem = htab_map_seq_show_elem, | 
 | }; | 
 |  | 
 | /* Called from eBPF program */ | 
 | static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key) | 
 | { | 
 | 	struct htab_elem *l = __htab_map_lookup_elem(map, key); | 
 |  | 
 | 	if (l) | 
 | 		return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size)); | 
 | 	else | 
 | 		return NULL; | 
 | } | 
 |  | 
 | static void *htab_lru_percpu_map_lookup_elem(struct bpf_map *map, void *key) | 
 | { | 
 | 	struct htab_elem *l = __htab_map_lookup_elem(map, key); | 
 |  | 
 | 	if (l) { | 
 | 		bpf_lru_node_set_ref(&l->lru_node); | 
 | 		return this_cpu_ptr(htab_elem_get_ptr(l, map->key_size)); | 
 | 	} | 
 |  | 
 | 	return NULL; | 
 | } | 
 |  | 
 | int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value) | 
 | { | 
 | 	struct htab_elem *l; | 
 | 	void __percpu *pptr; | 
 | 	int ret = -ENOENT; | 
 | 	int cpu, off = 0; | 
 | 	u32 size; | 
 |  | 
 | 	/* per_cpu areas are zero-filled and bpf programs can only | 
 | 	 * access 'value_size' of them, so copying rounded areas | 
 | 	 * will not leak any kernel data | 
 | 	 */ | 
 | 	size = round_up(map->value_size, 8); | 
 | 	rcu_read_lock(); | 
 | 	l = __htab_map_lookup_elem(map, key); | 
 | 	if (!l) | 
 | 		goto out; | 
 | 	/* We do not mark LRU map element here in order to not mess up | 
 | 	 * eviction heuristics when user space does a map walk. | 
 | 	 */ | 
 | 	pptr = htab_elem_get_ptr(l, map->key_size); | 
 | 	for_each_possible_cpu(cpu) { | 
 | 		bpf_long_memcpy(value + off, | 
 | 				per_cpu_ptr(pptr, cpu), size); | 
 | 		off += size; | 
 | 	} | 
 | 	ret = 0; | 
 | out: | 
 | 	rcu_read_unlock(); | 
 | 	return ret; | 
 | } | 
 |  | 
 | int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, | 
 | 			   u64 map_flags) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	int ret; | 
 |  | 
 | 	rcu_read_lock(); | 
 | 	if (htab_is_lru(htab)) | 
 | 		ret = __htab_lru_percpu_map_update_elem(map, key, value, | 
 | 							map_flags, true); | 
 | 	else | 
 | 		ret = __htab_percpu_map_update_elem(map, key, value, map_flags, | 
 | 						    true); | 
 | 	rcu_read_unlock(); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static void htab_percpu_map_seq_show_elem(struct bpf_map *map, void *key, | 
 | 					  struct seq_file *m) | 
 | { | 
 | 	struct htab_elem *l; | 
 | 	void __percpu *pptr; | 
 | 	int cpu; | 
 |  | 
 | 	rcu_read_lock(); | 
 |  | 
 | 	l = __htab_map_lookup_elem(map, key); | 
 | 	if (!l) { | 
 | 		rcu_read_unlock(); | 
 | 		return; | 
 | 	} | 
 |  | 
 | 	btf_type_seq_show(map->btf, map->btf_key_type_id, key, m); | 
 | 	seq_puts(m, ": {\n"); | 
 | 	pptr = htab_elem_get_ptr(l, map->key_size); | 
 | 	for_each_possible_cpu(cpu) { | 
 | 		seq_printf(m, "\tcpu%d: ", cpu); | 
 | 		btf_type_seq_show(map->btf, map->btf_value_type_id, | 
 | 				  per_cpu_ptr(pptr, cpu), m); | 
 | 		seq_puts(m, "\n"); | 
 | 	} | 
 | 	seq_puts(m, "}\n"); | 
 |  | 
 | 	rcu_read_unlock(); | 
 | } | 
 |  | 
 | const struct bpf_map_ops htab_percpu_map_ops = { | 
 | 	.map_alloc_check = htab_map_alloc_check, | 
 | 	.map_alloc = htab_map_alloc, | 
 | 	.map_free = htab_map_free, | 
 | 	.map_get_next_key = htab_map_get_next_key, | 
 | 	.map_lookup_elem = htab_percpu_map_lookup_elem, | 
 | 	.map_update_elem = htab_percpu_map_update_elem, | 
 | 	.map_delete_elem = htab_map_delete_elem, | 
 | 	.map_seq_show_elem = htab_percpu_map_seq_show_elem, | 
 | }; | 
 |  | 
 | const struct bpf_map_ops htab_lru_percpu_map_ops = { | 
 | 	.map_alloc_check = htab_map_alloc_check, | 
 | 	.map_alloc = htab_map_alloc, | 
 | 	.map_free = htab_map_free, | 
 | 	.map_get_next_key = htab_map_get_next_key, | 
 | 	.map_lookup_elem = htab_lru_percpu_map_lookup_elem, | 
 | 	.map_update_elem = htab_lru_percpu_map_update_elem, | 
 | 	.map_delete_elem = htab_lru_map_delete_elem, | 
 | 	.map_seq_show_elem = htab_percpu_map_seq_show_elem, | 
 | }; | 
 |  | 
 | static int fd_htab_map_alloc_check(union bpf_attr *attr) | 
 | { | 
 | 	if (attr->value_size != sizeof(u32)) | 
 | 		return -EINVAL; | 
 | 	return htab_map_alloc_check(attr); | 
 | } | 
 |  | 
 | static void fd_htab_map_free(struct bpf_map *map) | 
 | { | 
 | 	struct bpf_htab *htab = container_of(map, struct bpf_htab, map); | 
 | 	struct hlist_nulls_node *n; | 
 | 	struct hlist_nulls_head *head; | 
 | 	struct htab_elem *l; | 
 | 	int i; | 
 |  | 
 | 	for (i = 0; i < htab->n_buckets; i++) { | 
 | 		head = select_bucket(htab, i); | 
 |  | 
 | 		hlist_nulls_for_each_entry_safe(l, n, head, hash_node) { | 
 | 			void *ptr = fd_htab_map_get_ptr(map, l); | 
 |  | 
 | 			map->ops->map_fd_put_ptr(map, ptr, false); | 
 | 		} | 
 | 	} | 
 |  | 
 | 	htab_map_free(map); | 
 | } | 
 |  | 
 | /* only called from syscall */ | 
 | int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) | 
 | { | 
 | 	void **ptr; | 
 | 	int ret = 0; | 
 |  | 
 | 	if (!map->ops->map_fd_sys_lookup_elem) | 
 | 		return -ENOTSUPP; | 
 |  | 
 | 	rcu_read_lock(); | 
 | 	ptr = htab_map_lookup_elem(map, key); | 
 | 	if (ptr) | 
 | 		*value = map->ops->map_fd_sys_lookup_elem(READ_ONCE(*ptr)); | 
 | 	else | 
 | 		ret = -ENOENT; | 
 | 	rcu_read_unlock(); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | /* only called from syscall */ | 
 | int bpf_fd_htab_map_update_elem(struct bpf_map *map, struct file *map_file, | 
 | 				void *key, void *value, u64 map_flags) | 
 | { | 
 | 	void *ptr; | 
 | 	int ret; | 
 | 	u32 ufd = *(u32 *)value; | 
 |  | 
 | 	ptr = map->ops->map_fd_get_ptr(map, map_file, ufd); | 
 | 	if (IS_ERR(ptr)) | 
 | 		return PTR_ERR(ptr); | 
 |  | 
 | 	ret = htab_map_update_elem(map, key, &ptr, map_flags); | 
 | 	if (ret) | 
 | 		map->ops->map_fd_put_ptr(map, ptr, false); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static struct bpf_map *htab_of_map_alloc(union bpf_attr *attr) | 
 | { | 
 | 	struct bpf_map *map, *inner_map_meta; | 
 |  | 
 | 	inner_map_meta = bpf_map_meta_alloc(attr->inner_map_fd); | 
 | 	if (IS_ERR(inner_map_meta)) | 
 | 		return inner_map_meta; | 
 |  | 
 | 	map = htab_map_alloc(attr); | 
 | 	if (IS_ERR(map)) { | 
 | 		bpf_map_meta_free(inner_map_meta); | 
 | 		return map; | 
 | 	} | 
 |  | 
 | 	map->inner_map_meta = inner_map_meta; | 
 |  | 
 | 	return map; | 
 | } | 
 |  | 
 | static void *htab_of_map_lookup_elem(struct bpf_map *map, void *key) | 
 | { | 
 | 	struct bpf_map **inner_map  = htab_map_lookup_elem(map, key); | 
 |  | 
 | 	if (!inner_map) | 
 | 		return NULL; | 
 |  | 
 | 	return READ_ONCE(*inner_map); | 
 | } | 
 |  | 
 | static u32 htab_of_map_gen_lookup(struct bpf_map *map, | 
 | 				  struct bpf_insn *insn_buf) | 
 | { | 
 | 	struct bpf_insn *insn = insn_buf; | 
 | 	const int ret = BPF_REG_0; | 
 |  | 
 | 	BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem, | 
 | 		     (void *(*)(struct bpf_map *map, void *key))NULL)); | 
 | 	*insn++ = BPF_EMIT_CALL(BPF_CAST_CALL(__htab_map_lookup_elem)); | 
 | 	*insn++ = BPF_JMP_IMM(BPF_JEQ, ret, 0, 2); | 
 | 	*insn++ = BPF_ALU64_IMM(BPF_ADD, ret, | 
 | 				offsetof(struct htab_elem, key) + | 
 | 				round_up(map->key_size, 8)); | 
 | 	*insn++ = BPF_LDX_MEM(BPF_DW, ret, ret, 0); | 
 |  | 
 | 	return insn - insn_buf; | 
 | } | 
 |  | 
 | static void htab_of_map_free(struct bpf_map *map) | 
 | { | 
 | 	bpf_map_meta_free(map->inner_map_meta); | 
 | 	fd_htab_map_free(map); | 
 | } | 
 |  | 
 | const struct bpf_map_ops htab_of_maps_map_ops = { | 
 | 	.map_alloc_check = fd_htab_map_alloc_check, | 
 | 	.map_alloc = htab_of_map_alloc, | 
 | 	.map_free = htab_of_map_free, | 
 | 	.map_get_next_key = htab_map_get_next_key, | 
 | 	.map_lookup_elem = htab_of_map_lookup_elem, | 
 | 	.map_delete_elem = htab_map_delete_elem, | 
 | 	.map_fd_get_ptr = bpf_map_fd_get_ptr, | 
 | 	.map_fd_put_ptr = bpf_map_fd_put_ptr, | 
 | 	.map_fd_sys_lookup_elem = bpf_map_fd_sys_lookup_elem, | 
 | 	.map_gen_lookup = htab_of_map_gen_lookup, | 
 | 	.map_check_btf = map_check_no_btf, | 
 | }; |