diff options
Diffstat (limited to 'kernel/bpf/hashtab.c')
-rw-r--r-- | kernel/bpf/hashtab.c | 416 |
1 files changed, 216 insertions, 200 deletions
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 3a088a5349bc..71f9931ac64c 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -16,6 +16,7 @@ #include "bpf_lru_list.h" #include "map_in_map.h" #include <linux/bpf_mem_alloc.h> +#include <asm/rqspinlock.h> #define HTAB_CREATE_FLAG_MASK \ (BPF_F_NO_PREALLOC | BPF_F_NO_COMMON_LRU | BPF_F_NUMA_NODE | \ @@ -78,7 +79,7 @@ */ struct bucket { struct hlist_nulls_head head; - raw_spinlock_t raw_lock; + rqspinlock_t raw_lock; }; #define HASHTAB_MAP_LOCK_COUNT 8 @@ -104,8 +105,6 @@ struct bpf_htab { u32 n_buckets; /* number of hash buckets */ u32 elem_size; /* size of each element in bytes */ u32 hashrnd; - struct lock_class_key lockdep_key; - int __percpu *map_locked[HASHTAB_MAP_LOCK_COUNT]; }; /* each htab element is struct htab_elem + key + value */ @@ -140,45 +139,26 @@ static void htab_init_buckets(struct bpf_htab *htab) for (i = 0; i < htab->n_buckets; i++) { INIT_HLIST_NULLS_HEAD(&htab->buckets[i].head, i); - raw_spin_lock_init(&htab->buckets[i].raw_lock); - lockdep_set_class(&htab->buckets[i].raw_lock, - &htab->lockdep_key); + raw_res_spin_lock_init(&htab->buckets[i].raw_lock); cond_resched(); } } -static inline int htab_lock_bucket(const struct bpf_htab *htab, - struct bucket *b, u32 hash, - unsigned long *pflags) +static inline int htab_lock_bucket(struct bucket *b, unsigned long *pflags) { unsigned long flags; + int ret; - hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1); - - preempt_disable(); - local_irq_save(flags); - if (unlikely(__this_cpu_inc_return(*(htab->map_locked[hash])) != 1)) { - __this_cpu_dec(*(htab->map_locked[hash])); - local_irq_restore(flags); - preempt_enable(); - return -EBUSY; - } - - raw_spin_lock(&b->raw_lock); + ret = raw_res_spin_lock_irqsave(&b->raw_lock, flags); + if (ret) + return ret; *pflags = flags; - return 0; } -static inline void htab_unlock_bucket(const struct bpf_htab *htab, - struct bucket *b, u32 hash, - unsigned long flags) +static inline void htab_unlock_bucket(struct bucket *b, unsigned long flags) { - hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1); - raw_spin_unlock(&b->raw_lock); - __this_cpu_dec(*(htab->map_locked[hash])); - local_irq_restore(flags); - preempt_enable(); + raw_res_spin_unlock_irqrestore(&b->raw_lock, flags); } static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node); @@ -195,20 +175,30 @@ static bool htab_is_percpu(const struct bpf_htab *htab) htab->map.map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH; } +static inline bool is_fd_htab(const struct bpf_htab *htab) +{ + return htab->map.map_type == BPF_MAP_TYPE_HASH_OF_MAPS; +} + +static inline void *htab_elem_value(struct htab_elem *l, u32 key_size) +{ + return l->key + round_up(key_size, 8); +} + static inline void htab_elem_set_ptr(struct htab_elem *l, u32 key_size, void __percpu *pptr) { - *(void __percpu **)(l->key + key_size) = pptr; + *(void __percpu **)htab_elem_value(l, 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); + return *(void __percpu **)htab_elem_value(l, 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)); + return *(void **)htab_elem_value(l, map->key_size); } static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i) @@ -216,18 +206,20 @@ static struct htab_elem *get_htab_elem(struct bpf_htab *htab, int i) return (struct htab_elem *) (htab->elems + i * (u64)htab->elem_size); } +/* Both percpu and fd htab support in-place update, so no need for + * extra elem. LRU itself can remove the least used element, so + * there is no need for an extra elem during map_update. + */ static bool htab_has_extra_elems(struct bpf_htab *htab) { - return !htab_is_percpu(htab) && !htab_is_lru(htab); + return !htab_is_percpu(htab) && !htab_is_lru(htab) && !is_fd_htab(htab); } -static void htab_free_prealloced_timers(struct bpf_htab *htab) +static void htab_free_prealloced_timers_and_wq(struct bpf_htab *htab) { u32 num_entries = htab->map.max_entries; int i; - if (!btf_record_has_field(htab->map.record, BPF_TIMER)) - return; if (htab_has_extra_elems(htab)) num_entries += num_possible_cpus(); @@ -235,7 +227,12 @@ static void htab_free_prealloced_timers(struct bpf_htab *htab) struct htab_elem *elem; elem = get_htab_elem(htab, i); - bpf_obj_free_timer(htab->map.record, elem->key + round_up(htab->map.key_size, 8)); + if (btf_record_has_field(htab->map.record, BPF_TIMER)) + bpf_obj_free_timer(htab->map.record, + htab_elem_value(elem, htab->map.key_size)); + if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) + bpf_obj_free_workqueue(htab->map.record, + htab_elem_value(elem, htab->map.key_size)); cond_resched(); } } @@ -262,7 +259,8 @@ static void htab_free_prealloced_fields(struct bpf_htab *htab) cond_resched(); } } else { - bpf_obj_free_fields(htab->map.record, elem->key + round_up(htab->map.key_size, 8)); + bpf_obj_free_fields(htab->map.record, + htab_elem_value(elem, htab->map.key_size)); cond_resched(); } cond_resched(); @@ -459,6 +457,9 @@ static int htab_map_alloc_check(union bpf_attr *attr) * 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; } @@ -467,8 +468,6 @@ 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 @@ -477,14 +476,12 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) 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; + int err; htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE); if (!htab) return ERR_PTR(-ENOMEM); - lockdep_register_key(&htab->lockdep_key); - bpf_map_init_from_attr(&htab->map, attr); if (percpu_lru) { @@ -530,15 +527,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) if (!htab->buckets) goto free_elem_count; - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) { - htab->map_locked[i] = bpf_map_alloc_percpu(&htab->map, - sizeof(int), - sizeof(int), - GFP_USER); - if (!htab->map_locked[i]) - goto free_map_locked; - } - if (htab->map.map_flags & BPF_F_ZERO_SEED) htab->hashrnd = 0; else @@ -574,10 +562,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) if (err) goto free_map_locked; - if (!percpu && !lru) { - /* lru itself can remove the least used element, so - * there is no need for an extra elem during map_update. - */ + if (htab_has_extra_elems(htab)) { err = alloc_extra_elems(htab); if (err) goto free_prealloc; @@ -601,15 +586,12 @@ free_prealloc: free_map_locked: if (htab->use_percpu_counter) percpu_counter_destroy(&htab->pcount); - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) - free_percpu(htab->map_locked[i]); bpf_map_area_free(htab->buckets); bpf_mem_alloc_destroy(&htab->pcpu_ma); bpf_mem_alloc_destroy(&htab->ma); free_elem_count: bpf_map_free_elem_count(&htab->map); free_htab: - lockdep_unregister_key(&htab->lockdep_key); bpf_map_area_free(htab); return ERR_PTR(err); } @@ -698,7 +680,7 @@ 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 htab_elem_value(l, map->key_size); return NULL; } @@ -737,7 +719,7 @@ static __always_inline void *__htab_lru_map_lookup_elem(struct bpf_map *map, if (l) { if (mark) bpf_lru_node_set_ref(&l->lru_node); - return l->key + round_up(map->key_size, 8); + return htab_elem_value(l, map->key_size); } return NULL; @@ -781,6 +763,9 @@ static int htab_lru_map_gen_lookup(struct bpf_map *map, static void check_and_free_fields(struct bpf_htab *htab, struct htab_elem *elem) { + if (IS_ERR_OR_NULL(htab->map.record)) + return; + if (htab_is_percpu(htab)) { void __percpu *pptr = htab_elem_get_ptr(elem, htab->map.key_size); int cpu; @@ -788,7 +773,7 @@ static void check_and_free_fields(struct bpf_htab *htab, for_each_possible_cpu(cpu) bpf_obj_free_fields(htab->map.record, per_cpu_ptr(pptr, cpu)); } else { - void *map_value = elem->key + round_up(htab->map.key_size, 8); + void *map_value = htab_elem_value(elem, htab->map.key_size); bpf_obj_free_fields(htab->map.record, map_value); } @@ -811,20 +796,21 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) b = __select_bucket(htab, tgt_l->hash); head = &b->head; - ret = htab_lock_bucket(htab, b, tgt_l->hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return false; hlist_nulls_for_each_entry_rcu(l, n, head, hash_node) if (l == tgt_l) { hlist_nulls_del_rcu(&l->hash_node); - check_and_free_fields(htab, l); bpf_map_dec_elem_count(&htab->map); break; } - htab_unlock_bucket(htab, b, tgt_l->hash, flags); + htab_unlock_bucket(b, flags); + if (l == tgt_l) + check_and_free_fields(htab, l); return l == tgt_l; } @@ -890,6 +876,7 @@ find_first_elem: static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l) { check_and_free_fields(htab, l); + if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH) bpf_mem_cache_free(&htab->pcpu_ma, l->ptr_to_pptr); bpf_mem_cache_free(&htab->ma, l); @@ -942,7 +929,7 @@ static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) if (htab_is_prealloc(htab)) { bpf_map_dec_elem_count(&htab->map); check_and_free_fields(htab, l); - __pcpu_freelist_push(&htab->freelist, &l->fnode); + pcpu_freelist_push(&htab->freelist, &l->fnode); } else { dec_elem_count(htab); htab_elem_free(htab, l); @@ -991,8 +978,7 @@ static void pcpu_init_value(struct bpf_htab *htab, void __percpu *pptr, 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; + return is_fd_htab(htab) && BITS_PER_LONG == 64; } static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key, @@ -1012,7 +998,6 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key, */ 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; @@ -1046,14 +1031,15 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key, pptr = htab_elem_get_ptr(l_new, key_size); } else { /* alloc_percpu zero-fills */ - pptr = bpf_mem_cache_alloc(&htab->pcpu_ma); - if (!pptr) { + void *ptr = bpf_mem_cache_alloc(&htab->pcpu_ma); + + if (!ptr) { bpf_mem_cache_free(&htab->ma, l_new); l_new = ERR_PTR(-ENOMEM); goto dec_count; } - l_new->ptr_to_pptr = pptr; - pptr = *(void **)pptr; + l_new->ptr_to_pptr = ptr; + pptr = *(void __percpu **)ptr; } pcpu_init_value(htab, pptr, value, onallcpus); @@ -1062,11 +1048,9 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key, 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); + memcpy(htab_elem_value(l_new, key_size), value, size); } else { - copy_map_value(&htab->map, - l_new->key + round_up(key_size, 8), - value); + copy_map_value(&htab->map, htab_elem_value(l_new, key_size), value); } l_new->hash = hash; @@ -1095,7 +1079,7 @@ static long 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 htab_elem *l_new, *l_old; struct hlist_nulls_head *head; unsigned long flags; struct bucket *b; @@ -1128,7 +1112,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, 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), + htab_elem_value(l_old, key_size), value, false); return 0; } @@ -1138,7 +1122,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, */ } - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return ret; @@ -1156,7 +1140,7 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, * and update element in place */ copy_map_value_locked(map, - l_old->key + round_up(key_size, 8), + htab_elem_value(l_old, key_size), value, false); ret = 0; goto err; @@ -1176,14 +1160,19 @@ static long htab_map_update_elem(struct bpf_map *map, void *key, void *value, 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); - else + + /* l_old has already been stashed in htab->extra_elems, free + * its special fields before it is available for reuse. + */ + if (htab_is_prealloc(htab)) check_and_free_fields(htab, l_old); } - ret = 0; + htab_unlock_bucket(b, flags); + if (l_old && !htab_is_prealloc(htab)) + free_htab_elem(htab, l_old); + return 0; err: - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); return ret; } @@ -1227,10 +1216,9 @@ static long htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value l_new = prealloc_lru_pop(htab, key, hash); if (!l_new) return -ENOMEM; - copy_map_value(&htab->map, - l_new->key + round_up(map->key_size, 8), value); + copy_map_value(&htab->map, htab_elem_value(l_new, map->key_size), value); - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) goto err_lock_bucket; @@ -1251,7 +1239,7 @@ static long htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value ret = 0; err: - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); err_lock_bucket: if (ret) @@ -1262,13 +1250,14 @@ err_lock_bucket: return ret; } -static long __htab_percpu_map_update_elem(struct bpf_map *map, void *key, +static long htab_map_update_elem_in_place(struct bpf_map *map, void *key, void *value, u64 map_flags, - bool onallcpus) + bool percpu, bool onallcpus) { struct bpf_htab *htab = container_of(map, struct bpf_htab, map); - struct htab_elem *l_new = NULL, *l_old; + struct htab_elem *l_new, *l_old; struct hlist_nulls_head *head; + void *old_map_ptr = NULL; unsigned long flags; struct bucket *b; u32 key_size, hash; @@ -1288,7 +1277,7 @@ static long __htab_percpu_map_update_elem(struct bpf_map *map, void *key, b = __select_bucket(htab, hash); head = &b->head; - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return ret; @@ -1299,21 +1288,29 @@ static long __htab_percpu_map_update_elem(struct bpf_map *map, void *key, 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); + /* Update value in-place */ + if (percpu) { + pcpu_copy_value(htab, htab_elem_get_ptr(l_old, key_size), + value, onallcpus); + } else { + void **inner_map_pptr = htab_elem_value(l_old, key_size); + + old_map_ptr = *inner_map_pptr; + WRITE_ONCE(*inner_map_pptr, *(void **)value); + } } else { l_new = alloc_htab_elem(htab, key, value, key_size, - hash, true, onallcpus, NULL); + hash, percpu, 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: - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); + if (old_map_ptr) + map->ops->map_fd_put_ptr(map, old_map_ptr, true); return ret; } @@ -1354,7 +1351,7 @@ static long __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, return -ENOMEM; } - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) goto err_lock_bucket; @@ -1378,7 +1375,7 @@ static long __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, } ret = 0; err: - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); err_lock_bucket: if (l_new) { bpf_map_dec_elem_count(&htab->map); @@ -1390,7 +1387,7 @@ err_lock_bucket: static long 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); + return htab_map_update_elem_in_place(map, key, value, map_flags, true, false); } static long htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, @@ -1420,20 +1417,20 @@ static long htab_map_delete_elem(struct bpf_map *map, void *key) b = __select_bucket(htab, hash); head = &b->head; - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return ret; l = lookup_elem_raw(head, hash, key, key_size); - - if (l) { + if (l) hlist_nulls_del_rcu(&l->hash_node); - free_htab_elem(htab, l); - } else { + else ret = -ENOENT; - } - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); + + if (l) + free_htab_elem(htab, l); return ret; } @@ -1456,7 +1453,7 @@ static long htab_lru_map_delete_elem(struct bpf_map *map, void *key) b = __select_bucket(htab, hash); head = &b->head; - ret = htab_lock_bucket(htab, b, hash, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) return ret; @@ -1467,7 +1464,7 @@ static long htab_lru_map_delete_elem(struct bpf_map *map, void *key) else ret = -ENOENT; - htab_unlock_bucket(htab, b, hash, flags); + htab_unlock_bucket(b, flags); if (l) htab_lru_push_free(htab, l); return ret; @@ -1477,10 +1474,9 @@ static void delete_all_elements(struct bpf_htab *htab) { int i; - /* It's called from a worker thread, so disable migration here, - * since bpf_mem_cache_free() relies on that. + /* It's called from a worker thread and migration has been disabled, + * therefore, it is OK to invoke bpf_mem_cache_free() directly. */ - migrate_disable(); for (i = 0; i < htab->n_buckets; i++) { struct hlist_nulls_head *head = select_bucket(htab, i); struct hlist_nulls_node *n; @@ -1490,11 +1486,11 @@ static void delete_all_elements(struct bpf_htab *htab) hlist_nulls_del_rcu(&l->hash_node); htab_elem_free(htab, l); } + cond_resched(); } - migrate_enable(); } -static void htab_free_malloced_timers(struct bpf_htab *htab) +static void htab_free_malloced_timers_and_wq(struct bpf_htab *htab) { int i; @@ -1506,31 +1502,35 @@ static void htab_free_malloced_timers(struct bpf_htab *htab) hlist_nulls_for_each_entry(l, n, head, hash_node) { /* We only free timer on uref dropping to zero */ - bpf_obj_free_timer(htab->map.record, l->key + round_up(htab->map.key_size, 8)); + if (btf_record_has_field(htab->map.record, BPF_TIMER)) + bpf_obj_free_timer(htab->map.record, + htab_elem_value(l, htab->map.key_size)); + if (btf_record_has_field(htab->map.record, BPF_WORKQUEUE)) + bpf_obj_free_workqueue(htab->map.record, + htab_elem_value(l, htab->map.key_size)); } cond_resched_rcu(); } rcu_read_unlock(); } -static void htab_map_free_timers(struct bpf_map *map) +static void htab_map_free_timers_and_wq(struct bpf_map *map) { struct bpf_htab *htab = container_of(map, struct bpf_htab, map); - /* We only free timer on uref dropping to zero */ - if (!btf_record_has_field(htab->map.record, BPF_TIMER)) - return; - if (!htab_is_prealloc(htab)) - htab_free_malloced_timers(htab); - else - htab_free_prealloced_timers(htab); + /* We only free timer and workqueue on uref dropping to zero */ + if (btf_record_has_field(htab->map.record, BPF_TIMER | BPF_WORKQUEUE)) { + if (!htab_is_prealloc(htab)) + htab_free_malloced_timers_and_wq(htab); + else + htab_free_prealloced_timers_and_wq(htab); + } } /* 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); - int i; /* bpf_free_used_maps() or close(map_fd) will trigger this map_free callback. * bpf_free_used_maps() is called after bpf prog is no longer executing. @@ -1538,7 +1538,7 @@ static void htab_map_free(struct bpf_map *map) */ /* htab no longer uses call_rcu() directly. bpf_mem_alloc does it - * underneath and is reponsible for waiting for callbacks to finish + * underneath and is responsible for waiting for callbacks to finish * during bpf_mem_alloc_destroy(). */ if (!htab_is_prealloc(htab)) { @@ -1555,9 +1555,6 @@ static void htab_map_free(struct bpf_map *map) bpf_mem_alloc_destroy(&htab->ma); if (htab->use_percpu_counter) percpu_counter_destroy(&htab->pcount); - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) - free_percpu(htab->map_locked[i]); - lockdep_unregister_key(&htab->lockdep_key); bpf_map_area_free(htab); } @@ -1577,7 +1574,7 @@ static void htab_map_seq_show_elem(struct bpf_map *map, void *key, 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"); + seq_putc(m, '\n'); rcu_read_unlock(); } @@ -1600,48 +1597,48 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key, b = __select_bucket(htab, hash); head = &b->head; - ret = htab_lock_bucket(htab, b, hash, &bflags); + ret = htab_lock_bucket(b, &bflags); if (ret) return ret; l = lookup_elem_raw(head, hash, key, key_size); if (!l) { ret = -ENOENT; - } else { - if (is_percpu) { - u32 roundup_value_size = round_up(map->value_size, 8); - void __percpu *pptr; - int off = 0, cpu; + goto out_unlock; + } - pptr = htab_elem_get_ptr(l, key_size); - for_each_possible_cpu(cpu) { - copy_map_value_long(&htab->map, value + off, per_cpu_ptr(pptr, cpu)); - check_and_init_map_value(&htab->map, value + off); - off += roundup_value_size; - } - } else { - u32 roundup_key_size = round_up(map->key_size, 8); + if (is_percpu) { + u32 roundup_value_size = round_up(map->value_size, 8); + void __percpu *pptr; + int off = 0, cpu; - if (flags & BPF_F_LOCK) - copy_map_value_locked(map, value, l->key + - roundup_key_size, - true); - else - copy_map_value(map, value, l->key + - roundup_key_size); - /* Zeroing special fields in the temp buffer */ - check_and_init_map_value(map, value); + pptr = htab_elem_get_ptr(l, key_size); + for_each_possible_cpu(cpu) { + copy_map_value_long(&htab->map, value + off, per_cpu_ptr(pptr, cpu)); + check_and_init_map_value(&htab->map, value + off); + off += roundup_value_size; } + } else { + void *src = htab_elem_value(l, map->key_size); - hlist_nulls_del_rcu(&l->hash_node); - if (!is_lru_map) - free_htab_elem(htab, l); + if (flags & BPF_F_LOCK) + copy_map_value_locked(map, value, src, true); + else + copy_map_value(map, value, src); + /* Zeroing special fields in the temp buffer */ + check_and_init_map_value(map, value); } + hlist_nulls_del_rcu(&l->hash_node); - htab_unlock_bucket(htab, b, hash, bflags); +out_unlock: + htab_unlock_bucket(b, bflags); - if (is_lru_map && l) - htab_lru_push_free(htab, l); + if (l) { + if (is_lru_map) + htab_lru_push_free(htab, l); + else + free_htab_elem(htab, l); + } return ret; } @@ -1684,12 +1681,12 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, bool is_percpu) { struct bpf_htab *htab = container_of(map, struct bpf_htab, map); - u32 bucket_cnt, total, key_size, value_size, roundup_key_size; void *keys = NULL, *values = NULL, *value, *dst_key, *dst_val; void __user *uvalues = u64_to_user_ptr(attr->batch.values); void __user *ukeys = u64_to_user_ptr(attr->batch.keys); void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch); u32 batch, max_count, size, bucket_size, map_id; + u32 bucket_cnt, total, key_size, value_size; struct htab_elem *node_to_free = NULL; u64 elem_map_flags, map_flags; struct hlist_nulls_head *head; @@ -1724,7 +1721,6 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, return -ENOENT; key_size = htab->map.key_size; - roundup_key_size = round_up(htab->map.key_size, 8); value_size = htab->map.value_size; size = round_up(value_size, 8); if (is_percpu) @@ -1756,7 +1752,7 @@ again_nocopy: head = &b->head; /* do not grab the lock unless need it (bucket_cnt > 0). */ if (locked) { - ret = htab_lock_bucket(htab, b, batch, &flags); + ret = htab_lock_bucket(b, &flags); if (ret) { rcu_read_unlock(); bpf_enable_instrumentation(); @@ -1779,7 +1775,7 @@ again_nocopy: /* Note that since bucket_cnt > 0 here, it is implicit * that the locked was grabbed, so release it. */ - htab_unlock_bucket(htab, b, batch, flags); + htab_unlock_bucket(b, flags); rcu_read_unlock(); bpf_enable_instrumentation(); goto after_loop; @@ -1790,7 +1786,7 @@ again_nocopy: /* Note that since bucket_cnt > 0 here, it is implicit * that the locked was grabbed, so release it. */ - htab_unlock_bucket(htab, b, batch, flags); + htab_unlock_bucket(b, flags); rcu_read_unlock(); bpf_enable_instrumentation(); kvfree(keys); @@ -1816,8 +1812,8 @@ again_nocopy: off += size; } } else { - value = l->key + roundup_key_size; - if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) { + value = htab_elem_value(l, key_size); + if (is_fd_htab(htab)) { struct bpf_map **inner_map = value; /* Actual value is the id of the inner map */ @@ -1840,25 +1836,29 @@ again_nocopy: * may cause deadlock. See comments in function * prealloc_lru_pop(). Let us do bpf_lru_push_free() * after releasing the bucket lock. + * + * For htab of maps, htab_put_fd_value() in + * free_htab_elem() may acquire a spinlock with bucket + * lock being held and it violates the lock rule, so + * invoke free_htab_elem() after unlock as well. */ - if (is_lru_map) { - l->batch_flink = node_to_free; - node_to_free = l; - } else { - free_htab_elem(htab, l); - } + l->batch_flink = node_to_free; + node_to_free = l; } dst_key += key_size; dst_val += value_size; } - htab_unlock_bucket(htab, b, batch, flags); + htab_unlock_bucket(b, flags); locked = false; while (node_to_free) { l = node_to_free; node_to_free = node_to_free->batch_flink; - htab_lru_push_free(htab, l); + if (is_lru_map) + htab_lru_push_free(htab, l); + else + free_htab_elem(htab, l); } next_batch: @@ -2063,11 +2063,11 @@ static void *bpf_hash_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) static int __bpf_hash_map_seq_show(struct seq_file *seq, struct htab_elem *elem) { struct bpf_iter_seq_hash_map_info *info = seq->private; - u32 roundup_key_size, roundup_value_size; struct bpf_iter__bpf_map_elem ctx = {}; struct bpf_map *map = info->map; struct bpf_iter_meta meta; int ret = 0, off = 0, cpu; + u32 roundup_value_size; struct bpf_prog *prog; void __percpu *pptr; @@ -2077,10 +2077,9 @@ static int __bpf_hash_map_seq_show(struct seq_file *seq, struct htab_elem *elem) ctx.meta = &meta; ctx.map = info->map; if (elem) { - roundup_key_size = round_up(map->key_size, 8); ctx.key = elem->key; if (!info->percpu_value_buf) { - ctx.value = elem->key + roundup_key_size; + ctx.value = htab_elem_value(elem, map->key_size); } else { roundup_value_size = round_up(map->value_size, 8); pptr = htab_elem_get_ptr(elem, map->key_size); @@ -2165,7 +2164,6 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_ struct hlist_nulls_head *head; struct hlist_nulls_node *n; struct htab_elem *elem; - u32 roundup_key_size; int i, num_elems = 0; void __percpu *pptr; struct bucket *b; @@ -2173,29 +2171,29 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_ bool is_percpu; u64 ret = 0; + cant_migrate(); + if (flags != 0) return -EINVAL; is_percpu = htab_is_percpu(htab); - roundup_key_size = round_up(map->key_size, 8); - /* disable migration so percpu value prepared here will be the - * same as the one seen by the bpf program with bpf_map_lookup_elem(). + /* migration has been disabled, so percpu value prepared here will be + * the same as the one seen by the bpf program with + * bpf_map_lookup_elem(). */ - if (is_percpu) - migrate_disable(); for (i = 0; i < htab->n_buckets; i++) { b = &htab->buckets[i]; rcu_read_lock(); head = &b->head; - hlist_nulls_for_each_entry_rcu(elem, n, head, hash_node) { + hlist_nulls_for_each_entry_safe(elem, n, head, hash_node) { key = elem->key; if (is_percpu) { /* current cpu value for percpu map */ pptr = htab_elem_get_ptr(elem, map->key_size); val = this_cpu_ptr(pptr); } else { - val = elem->key + roundup_key_size; + val = htab_elem_value(elem, map->key_size); } num_elems++; ret = callback_fn((u64)(long)map, (u64)(long)key, @@ -2209,8 +2207,6 @@ static long bpf_for_each_hash_elem(struct bpf_map *map, bpf_callback_t callback_ rcu_read_unlock(); } out: - if (is_percpu) - migrate_enable(); return num_elems; } @@ -2259,7 +2255,7 @@ const struct bpf_map_ops htab_map_ops = { .map_alloc = htab_map_alloc, .map_free = htab_map_free, .map_get_next_key = htab_map_get_next_key, - .map_release_uref = htab_map_free_timers, + .map_release_uref = htab_map_free_timers_and_wq, .map_lookup_elem = htab_map_lookup_elem, .map_lookup_and_delete_elem = htab_map_lookup_and_delete_elem, .map_update_elem = htab_map_update_elem, @@ -2280,7 +2276,7 @@ const struct bpf_map_ops htab_lru_map_ops = { .map_alloc = htab_map_alloc, .map_free = htab_map_free, .map_get_next_key = htab_map_get_next_key, - .map_release_uref = htab_map_free_timers, + .map_release_uref = htab_map_free_timers_and_wq, .map_lookup_elem = htab_lru_map_lookup_elem, .map_lookup_and_delete_elem = htab_lru_map_lookup_and_delete_elem, .map_lookup_elem_sys_only = htab_lru_map_lookup_elem_sys, @@ -2307,6 +2303,26 @@ static void *htab_percpu_map_lookup_elem(struct bpf_map *map, void *key) return NULL; } +/* inline bpf_map_lookup_elem() call for per-CPU hashmap */ +static int htab_percpu_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) +{ + struct bpf_insn *insn = insn_buf; + + if (!bpf_jit_supports_percpu_insn()) + return -EOPNOTSUPP; + + BUILD_BUG_ON(!__same_type(&__htab_map_lookup_elem, + (void *(*)(struct bpf_map *map, void *key))NULL)); + *insn++ = BPF_EMIT_CALL(__htab_map_lookup_elem); + *insn++ = BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3); + *insn++ = BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, + offsetof(struct htab_elem, key) + roundup(map->key_size, 8)); + *insn++ = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0); + *insn++ = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0); + + return insn - insn_buf; +} + static void *htab_percpu_map_lookup_percpu_elem(struct bpf_map *map, void *key, u32 cpu) { struct htab_elem *l; @@ -2392,8 +2408,8 @@ int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, 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); + ret = htab_map_update_elem_in_place(map, key, value, map_flags, + true, true); rcu_read_unlock(); return ret; @@ -2421,7 +2437,7 @@ static void htab_percpu_map_seq_show_elem(struct bpf_map *map, void *key, 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_putc(m, '\n'); } seq_puts(m, "}\n"); @@ -2435,6 +2451,7 @@ const struct bpf_map_ops htab_percpu_map_ops = { .map_free = htab_map_free, .map_get_next_key = htab_map_get_next_key, .map_lookup_elem = htab_percpu_map_lookup_elem, + .map_gen_lookup = htab_percpu_map_gen_lookup, .map_lookup_and_delete_elem = htab_percpu_map_lookup_and_delete_elem, .map_update_elem = htab_percpu_map_update_elem, .map_delete_elem = htab_map_delete_elem, @@ -2516,24 +2533,23 @@ int bpf_fd_htab_map_lookup_elem(struct bpf_map *map, void *key, u32 *value) return ret; } -/* only called from syscall */ +/* 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); + ptr = map->ops->map_fd_get_ptr(map, map_file, *(int *)value); if (IS_ERR(ptr)) return PTR_ERR(ptr); /* The htab bucket lock is always held during update operations in fd * htab map, and the following rcu_read_lock() is only used to avoid - * the WARN_ON_ONCE in htab_map_update_elem(). + * the WARN_ON_ONCE in htab_map_update_elem_in_place(). */ rcu_read_lock(); - ret = htab_map_update_elem(map, key, &ptr, map_flags); + ret = htab_map_update_elem_in_place(map, key, &ptr, map_flags, false, false); rcu_read_unlock(); if (ret) map->ops->map_fd_put_ptr(map, ptr, false); |