From fca16e51078e8e5c0af839426b3d2dcd2bede135 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Fri, 26 Jul 2019 18:06:53 +0200 Subject: [PATCH] xdp: Refactor devmap allocation code for reuse MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The subsequent patch to add a new devmap sub-type can re-use much of the initialisation and allocation code, so refactor it into separate functions. Signed-off-by: Toke Høiland-Jørgensen Acked-by: Yonghong Song Acked-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov --- kernel/bpf/devmap.c | 136 ++++++++++++++++++++++++++++++++-------------------- 1 file changed, 83 insertions(+), 53 deletions(-) diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index d83cf8c..a050126 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -60,9 +60,9 @@ struct xdp_bulk_queue { struct bpf_dtab_netdev { struct net_device *dev; /* must be first member, due to tracepoint */ struct bpf_dtab *dtab; - unsigned int bit; struct xdp_bulk_queue __percpu *bulkq; struct rcu_head rcu; + unsigned int idx; /* keep track of map index for tracepoint */ }; struct bpf_dtab { @@ -75,28 +75,21 @@ struct bpf_dtab { static DEFINE_SPINLOCK(dev_map_lock); static LIST_HEAD(dev_map_list); -static struct bpf_map *dev_map_alloc(union bpf_attr *attr) +static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) { - struct bpf_dtab *dtab; int err, cpu; u64 cost; - if (!capable(CAP_NET_ADMIN)) - return ERR_PTR(-EPERM); - /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || attr->value_size != 4 || attr->map_flags & ~DEV_CREATE_FLAG_MASK) - return ERR_PTR(-EINVAL); + return -EINVAL; /* 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; - dtab = kzalloc(sizeof(*dtab), GFP_USER); - if (!dtab) - return ERR_PTR(-ENOMEM); bpf_map_init_from_attr(&dtab->map, attr); @@ -107,9 +100,7 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr) /* if map size is larger than memlock limit, reject it */ err = bpf_map_charge_init(&dtab->map.memory, cost); if (err) - goto free_dtab; - - err = -ENOMEM; + return -EINVAL; dtab->flush_list = alloc_percpu(struct list_head); if (!dtab->flush_list) @@ -124,19 +115,38 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr) if (!dtab->netdev_map) goto free_percpu; - spin_lock(&dev_map_lock); - list_add_tail_rcu(&dtab->list, &dev_map_list); - spin_unlock(&dev_map_lock); - - return &dtab->map; + return 0; free_percpu: free_percpu(dtab->flush_list); free_charge: bpf_map_charge_finish(&dtab->map.memory); -free_dtab: - kfree(dtab); - return ERR_PTR(err); + return -ENOMEM; +} + +static struct bpf_map *dev_map_alloc(union bpf_attr *attr) +{ + struct bpf_dtab *dtab; + int err; + + if (!capable(CAP_NET_ADMIN)) + return ERR_PTR(-EPERM); + + dtab = kzalloc(sizeof(*dtab), GFP_USER); + if (!dtab) + return ERR_PTR(-ENOMEM); + + err = dev_map_init_map(dtab, attr); + if (err) { + kfree(dtab); + return ERR_PTR(err); + } + + spin_lock(&dev_map_lock); + list_add_tail_rcu(&dtab->list, &dev_map_list); + spin_unlock(&dev_map_lock); + + return &dtab->map; } static void dev_map_free(struct bpf_map *map) @@ -235,7 +245,7 @@ static int bq_xmit_all(struct xdp_bulk_queue *bq, u32 flags, out: bq->count = 0; - trace_xdp_devmap_xmit(&obj->dtab->map, obj->bit, + trace_xdp_devmap_xmit(&obj->dtab->map, obj->idx, sent, drops, bq->dev_rx, dev, err); bq->dev_rx = NULL; __list_del_clearprev(&bq->flush_node); @@ -412,17 +422,52 @@ static int dev_map_delete_elem(struct bpf_map *map, void *key) return 0; } -static int dev_map_update_elem(struct bpf_map *map, void *key, void *value, - u64 map_flags) +static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net, + struct bpf_dtab *dtab, + u32 ifindex, + unsigned int idx) { - struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); - struct net *net = current->nsproxy->net_ns; gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN; + struct bpf_dtab_netdev *dev; + struct xdp_bulk_queue *bq; + int cpu; + + dev = kmalloc_node(sizeof(*dev), gfp, dtab->map.numa_node); + if (!dev) + return ERR_PTR(-ENOMEM); + + dev->bulkq = __alloc_percpu_gfp(sizeof(*dev->bulkq), + sizeof(void *), gfp); + if (!dev->bulkq) { + kfree(dev); + return ERR_PTR(-ENOMEM); + } + + for_each_possible_cpu(cpu) { + bq = per_cpu_ptr(dev->bulkq, cpu); + bq->obj = dev; + } + + dev->dev = dev_get_by_index(net, ifindex); + if (!dev->dev) { + free_percpu(dev->bulkq); + kfree(dev); + return ERR_PTR(-EINVAL); + } + + dev->idx = idx; + dev->dtab = dtab; + + return dev; +} + +static int __dev_map_update_elem(struct net *net, struct bpf_map *map, + void *key, void *value, u64 map_flags) +{ + struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct bpf_dtab_netdev *dev, *old_dev; u32 ifindex = *(u32 *)value; - struct xdp_bulk_queue *bq; u32 i = *(u32 *)key; - int cpu; if (unlikely(map_flags > BPF_EXIST)) return -EINVAL; @@ -434,31 +479,9 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value, if (!ifindex) { dev = NULL; } else { - dev = kmalloc_node(sizeof(*dev), gfp, map->numa_node); - if (!dev) - return -ENOMEM; - - dev->bulkq = __alloc_percpu_gfp(sizeof(*dev->bulkq), - sizeof(void *), gfp); - if (!dev->bulkq) { - kfree(dev); - return -ENOMEM; - } - - for_each_possible_cpu(cpu) { - bq = per_cpu_ptr(dev->bulkq, cpu); - bq->obj = dev; - } - - dev->dev = dev_get_by_index(net, ifindex); - if (!dev->dev) { - free_percpu(dev->bulkq); - kfree(dev); - return -EINVAL; - } - - dev->bit = i; - dev->dtab = dtab; + dev = __dev_map_alloc_node(net, dtab, ifindex, i); + if (IS_ERR(dev)) + return PTR_ERR(dev); } /* Use call_rcu() here to ensure rcu critical sections have completed @@ -472,6 +495,13 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value, return 0; } +static int dev_map_update_elem(struct bpf_map *map, void *key, void *value, + u64 map_flags) +{ + return __dev_map_update_elem(current->nsproxy->net_ns, + map, key, value, map_flags); +} + const struct bpf_map_ops dev_map_ops = { .map_alloc = dev_map_alloc, .map_free = dev_map_free, -- 2.7.4