| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Alexei Starovoitov | 3348 | 49.52% | 11 | 27.50% |
| Martin KaFai Lau | 2609 | 38.59% | 8 | 20.00% |
| Daniel Borkmann | 336 | 4.97% | 7 | 17.50% |
| Jakub Kiciński | 187 | 2.77% | 3 | 7.50% |
| Yonghong Song | 110 | 1.63% | 1 | 2.50% |
| Lei Ming | 100 | 1.48% | 3 | 7.50% |
| Mauricio Vasquez B | 33 | 0.49% | 1 | 2.50% |
| Sasha Levin | 14 | 0.21% | 1 | 2.50% |
| Teng Qin | 10 | 0.15% | 1 | 2.50% |
| Eric Dumazet | 6 | 0.09% | 1 | 2.50% |
| Johannes Berg | 5 | 0.07% | 1 | 2.50% |
| Yang Shi | 2 | 0.03% | 1 | 2.50% |
| Chenbo Feng | 1 | 0.01% | 1 | 2.50% |
| Total | 6761 | 40 |
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com * Copyright (c) 2016 Facebook * * 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 <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_RDONLY | BPF_F_WRONLY) 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); 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 (attr->map_flags & ~HTAB_CREATE_FLAG_MASK) /* reserved bits should not be used */ 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; 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 */ 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); err = -E2BIG; /* prevent zero size kmalloc and check for u32 overflow */ if (htab->n_buckets == 0 || 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 (cost >= U32_MAX - PAGE_SIZE) /* make sure page count doesn't overflow */ goto free_htab; htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; /* if map size is larger than memlock limit, reject it early */ err = bpf_map_precharge_memlock(htab->map.pages); 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_htab; 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_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 void *htab_lru_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 l->key + round_up(map->key_size, 8); } return NULL; } 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; /* must increment bpf_prog_active to avoid kprobe+bpf triggering while * we're calling kfree, otherwise deadlock is possible if kprobes * are placed somewhere inside of slub */ preempt_disable(); __this_cpu_inc(bpf_prog_active); htab_elem_free(htab, l); __this_cpu_dec(bpf_prog_active); preempt_enable(); } static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) { struct bpf_map *map = &htab->map; if (map->ops->map_fd_put_ptr) { void *ptr = fd_htab_map_get_ptr(map, l); map->ops->map_fd_put_ptr(ptr); } 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 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 u32 htab_size_value(const struct bpf_htab *htab, bool percpu) { u32 size = htab->map.value_size; if (percpu || fd_htab_map_needs_adjust(htab)) size = round_up(size, 8); return size; } 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_size_value(htab, percpu); 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; *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; } } memcpy(l_new->key, key, key_size); if (percpu) { 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_copy_value(htab, pptr, value, onallcpus); if (!prealloc) htab_elem_set_ptr(l_new, key_size, pptr); } else { memcpy(l_new->key + round_up(key_size, 8), value, size); } 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_NOEXIST) /* elem already exists */ return -EEXIST; if (!l_old && map_flags == 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_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; 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_copy_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_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 bpf_htab *htab = container_of(map, struct bpf_htab, map); 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; if (htab_is_lru(htab)) bpf_lru_node_set_ref(&l->lru_node); 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; } 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, }; 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, }; 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(ptr); } } 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(ptr); 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, };
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