diff options
Diffstat (limited to 'kernel/bpf/devmap.c')
| -rw-r--r-- | kernel/bpf/devmap.c | 57 |
1 files changed, 28 insertions, 29 deletions
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 7f3b34452243..9e0e3b0a18e4 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -83,7 +83,6 @@ struct bpf_dtab { u32 n_buckets; }; -static DEFINE_PER_CPU(struct list_head, dev_flush_list); static DEFINE_SPINLOCK(dev_map_lock); static LIST_HEAD(dev_map_list); @@ -107,7 +106,7 @@ static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab, return &dtab->dev_index_head[idx & (dtab->n_buckets - 1)]; } -static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) +static int dev_map_alloc_check(union bpf_attr *attr) { u32 valsize = attr->value_size; @@ -121,23 +120,28 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) attr->map_flags & ~DEV_CREATE_FLAG_MASK) return -EINVAL; + if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) { + /* Hash table size must be power of 2; roundup_pow_of_two() + * can overflow into UB on 32-bit arches + */ + if (attr->max_entries > 1UL << 31) + return -EINVAL; + } + + return 0; +} + +static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) +{ /* Lookup returns a pointer straight to dev->ifindex, so make sure the * verifier prevents writes from the BPF side */ attr->map_flags |= BPF_F_RDONLY_PROG; - - bpf_map_init_from_attr(&dtab->map, attr); if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) { - /* hash table size must be power of 2; roundup_pow_of_two() can - * overflow into UB on 32-bit arches, so check that first - */ - if (dtab->map.max_entries > 1UL << 31) - return -EINVAL; - + /* Hash table size must be power of 2 */ dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries); - dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets, dtab->map.numa_node); if (!dtab->dev_index_head) @@ -196,7 +200,14 @@ static void dev_map_free(struct bpf_map *map) list_del_rcu(&dtab->list); spin_unlock(&dev_map_lock); - bpf_clear_redirect_map(map); + /* bpf_redirect_info->map is assigned in __bpf_xdp_redirect_map() + * during NAPI callback and cleared after the XDP redirect. There is no + * explicit RCU read section which protects bpf_redirect_info->map but + * local_bh_disable() also marks the beginning an RCU section. This + * makes the complete softirq callback RCU protected. Thus after + * following synchronize_rcu() there no bpf_redirect_info->map == map + * assignment. + */ synchronize_rcu(); /* Make sure prior __dev_map_entry_free() have completed. */ @@ -406,9 +417,8 @@ out: * driver before returning from its napi->poll() routine. See the comment above * xdp_do_flush() in filter.c. */ -void __dev_flush(void) +void __dev_flush(struct list_head *flush_list) { - struct list_head *flush_list = this_cpu_ptr(&dev_flush_list); struct xdp_dev_bulk_queue *bq, *tmp; list_for_each_entry_safe(bq, tmp, flush_list, flush_node) { @@ -419,16 +429,6 @@ void __dev_flush(void) } } -#ifdef CONFIG_DEBUG_NET -bool dev_check_flush(void) -{ - if (list_empty(this_cpu_ptr(&dev_flush_list))) - return false; - __dev_flush(); - return true; -} -#endif - /* Elements are kept alive by RCU; either by rcu_read_lock() (from syscall) or * by local_bh_disable() (from XDP calls inside NAPI). The * rcu_read_lock_bh_held() below makes lockdep accept both. @@ -453,7 +453,6 @@ static void *__dev_map_lookup_elem(struct bpf_map *map, u32 key) static void bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf, struct net_device *dev_rx, struct bpf_prog *xdp_prog) { - struct list_head *flush_list = this_cpu_ptr(&dev_flush_list); struct xdp_dev_bulk_queue *bq = this_cpu_ptr(dev->xdp_bulkq); if (unlikely(bq->count == DEV_MAP_BULK_SIZE)) @@ -467,6 +466,8 @@ static void bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf, * are only ever modified together. */ if (!bq->dev_rx) { + struct list_head *flush_list = bpf_net_ctx_get_dev_flush_list(); + bq->dev_rx = dev_rx; bq->xdp_prog = xdp_prog; list_add(&bq->flush_node, flush_list); @@ -1040,6 +1041,7 @@ static u64 dev_map_mem_usage(const struct bpf_map *map) BTF_ID_LIST_SINGLE(dev_map_btf_ids, struct, bpf_dtab) const struct bpf_map_ops dev_map_ops = { .map_meta_equal = bpf_map_meta_equal, + .map_alloc_check = dev_map_alloc_check, .map_alloc = dev_map_alloc, .map_free = dev_map_free, .map_get_next_key = dev_map_get_next_key, @@ -1054,6 +1056,7 @@ const struct bpf_map_ops dev_map_ops = { const struct bpf_map_ops dev_map_hash_ops = { .map_meta_equal = bpf_map_meta_equal, + .map_alloc_check = dev_map_alloc_check, .map_alloc = dev_map_alloc, .map_free = dev_map_free, .map_get_next_key = dev_map_hash_get_next_key, @@ -1153,15 +1156,11 @@ static struct notifier_block dev_map_notifier = { static int __init dev_map_init(void) { - int cpu; - /* Assure tracepoint shadow struct _bpf_dtab_netdev is in sync */ BUILD_BUG_ON(offsetof(struct bpf_dtab_netdev, dev) != offsetof(struct _bpf_dtab_netdev, dev)); register_netdevice_notifier(&dev_map_notifier); - for_each_possible_cpu(cpu) - INIT_LIST_HEAD(&per_cpu(dev_flush_list, cpu)); return 0; } |