ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/kernel/bpf/devmap.c b/marvell/linux/kernel/bpf/devmap.c
new file mode 100644
index 0000000..08ff40e
--- /dev/null
+++ b/marvell/linux/kernel/bpf/devmap.c
@@ -0,0 +1,794 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
+ */
+
+/* Devmaps primary use is as a backend map for XDP BPF helper call
+ * bpf_redirect_map(). Because XDP is mostly concerned with performance we
+ * spent some effort to ensure the datapath with redirect maps does not use
+ * any locking. This is a quick note on the details.
+ *
+ * We have three possible paths to get into the devmap control plane bpf
+ * syscalls, bpf programs, and driver side xmit/flush operations. A bpf syscall
+ * will invoke an update, delete, or lookup operation. To ensure updates and
+ * deletes appear atomic from the datapath side xchg() is used to modify the
+ * netdev_map array. Then because the datapath does a lookup into the netdev_map
+ * array (read-only) from an RCU critical section we use call_rcu() to wait for
+ * an rcu grace period before free'ing the old data structures. This ensures the
+ * datapath always has a valid copy. However, the datapath does a "flush"
+ * operation that pushes any pending packets in the driver outside the RCU
+ * critical section. Each bpf_dtab_netdev tracks these pending operations using
+ * a per-cpu flush list. The bpf_dtab_netdev object will not be destroyed until
+ * this list is empty, indicating outstanding flush operations have completed.
+ *
+ * BPF syscalls may race with BPF program calls on any of the update, delete
+ * or lookup operations. As noted above the xchg() operation also keep the
+ * netdev_map consistent in this case. From the devmap side BPF programs
+ * calling into these operations are the same as multiple user space threads
+ * making system calls.
+ *
+ * Finally, any of the above may race with a netdev_unregister notifier. The
+ * unregister notifier must search for net devices in the map structure that
+ * contain a reference to the net device and remove them. This is a two step
+ * process (a) dereference the bpf_dtab_netdev object in netdev_map and (b)
+ * check to see if the ifindex is the same as the net_device being removed.
+ * When removing the dev a cmpxchg() is used to ensure the correct dev is
+ * removed, in the case of a concurrent update or delete operation it is
+ * possible that the initially referenced dev is no longer in the map. As the
+ * notifier hook walks the map we know that new dev references can not be
+ * added by the user because core infrastructure ensures dev_get_by_index()
+ * calls will fail at this point.
+ *
+ * The devmap_hash type is a map type which interprets keys as ifindexes and
+ * indexes these using a hashmap. This allows maps that use ifindex as key to be
+ * densely packed instead of having holes in the lookup array for unused
+ * ifindexes. The setup and packet enqueue/send code is shared between the two
+ * types of devmap; only the lookup and insertion is different.
+ */
+#include <linux/bpf.h>
+#include <net/xdp.h>
+#include <linux/filter.h>
+#include <trace/events/xdp.h>
+
+#define DEV_CREATE_FLAG_MASK \
+ (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+
+#define DEV_MAP_BULK_SIZE 16
+struct bpf_dtab_netdev;
+
+struct xdp_bulk_queue {
+ struct xdp_frame *q[DEV_MAP_BULK_SIZE];
+ struct list_head flush_node;
+ struct net_device *dev_rx;
+ struct bpf_dtab_netdev *obj;
+ unsigned int count;
+};
+
+struct bpf_dtab_netdev {
+ struct net_device *dev; /* must be first member, due to tracepoint */
+ struct hlist_node index_hlist;
+ struct bpf_dtab *dtab;
+ struct xdp_bulk_queue __percpu *bulkq;
+ struct rcu_head rcu;
+ unsigned int idx; /* keep track of map index for tracepoint */
+};
+
+struct bpf_dtab {
+ struct bpf_map map;
+ struct bpf_dtab_netdev **netdev_map; /* DEVMAP type only */
+ struct list_head __percpu *flush_list;
+ struct list_head list;
+
+ /* these are only used for DEVMAP_HASH type maps */
+ struct hlist_head *dev_index_head;
+ spinlock_t index_lock;
+ unsigned int items;
+ u32 n_buckets;
+};
+
+static DEFINE_SPINLOCK(dev_map_lock);
+static LIST_HEAD(dev_map_list);
+
+static struct hlist_head *dev_map_create_hash(unsigned int entries,
+ int numa_node)
+{
+ int i;
+ struct hlist_head *hash;
+
+ hash = bpf_map_area_alloc((u64) entries * sizeof(*hash), numa_node);
+ if (hash != NULL)
+ for (i = 0; i < entries; i++)
+ INIT_HLIST_HEAD(&hash[i]);
+
+ return hash;
+}
+
+static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab,
+ int idx)
+{
+ return &dtab->dev_index_head[idx & (dtab->n_buckets - 1)];
+}
+
+static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
+{
+ int err, cpu;
+ u64 cost;
+
+ /* 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 -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;
+
+
+ bpf_map_init_from_attr(&dtab->map, attr);
+
+ /* make sure page count doesn't overflow */
+ cost = (u64) sizeof(struct list_head) * num_possible_cpus();
+
+ 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;
+
+ dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
+ cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;
+ } else {
+ cost += (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
+ }
+
+ /* if map size is larger than memlock limit, reject it */
+ err = bpf_map_charge_init(&dtab->map.memory, cost);
+ if (err)
+ return -EINVAL;
+
+ dtab->flush_list = alloc_percpu(struct list_head);
+ if (!dtab->flush_list)
+ goto free_charge;
+
+ for_each_possible_cpu(cpu)
+ INIT_LIST_HEAD(per_cpu_ptr(dtab->flush_list, cpu));
+
+ if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+ dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets,
+ dtab->map.numa_node);
+ if (!dtab->dev_index_head)
+ goto free_percpu;
+
+ spin_lock_init(&dtab->index_lock);
+ } else {
+ dtab->netdev_map = bpf_map_area_alloc((u64) dtab->map.max_entries *
+ sizeof(struct bpf_dtab_netdev *),
+ dtab->map.numa_node);
+ if (!dtab->netdev_map)
+ goto free_percpu;
+ }
+
+ return 0;
+
+free_percpu:
+ free_percpu(dtab->flush_list);
+free_charge:
+ bpf_map_charge_finish(&dtab->map.memory);
+ 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)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ u32 i;
+
+ /* 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. The following synchronize_rcu() guarantees
+ * both rcu read critical sections complete and waits for
+ * preempt-disable regions (NAPI being the relevant context here) so we
+ * are certain there will be no further reads against the netdev_map and
+ * all flush operations are complete. Flush operations can only be done
+ * from NAPI context for this reason.
+ */
+
+ spin_lock(&dev_map_lock);
+ list_del_rcu(&dtab->list);
+ spin_unlock(&dev_map_lock);
+
+ bpf_clear_redirect_map(map);
+ synchronize_rcu();
+
+ /* Make sure prior __dev_map_entry_free() have completed. */
+ rcu_barrier();
+
+ if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+ for (i = 0; i < dtab->n_buckets; i++) {
+ struct bpf_dtab_netdev *dev;
+ struct hlist_head *head;
+ struct hlist_node *next;
+
+ head = dev_map_index_hash(dtab, i);
+
+ hlist_for_each_entry_safe(dev, next, head, index_hlist) {
+ hlist_del_rcu(&dev->index_hlist);
+ free_percpu(dev->bulkq);
+ dev_put(dev->dev);
+ kfree(dev);
+ }
+ }
+
+ bpf_map_area_free(dtab->dev_index_head);
+ } else {
+ for (i = 0; i < dtab->map.max_entries; i++) {
+ struct bpf_dtab_netdev *dev;
+
+ dev = dtab->netdev_map[i];
+ if (!dev)
+ continue;
+
+ free_percpu(dev->bulkq);
+ dev_put(dev->dev);
+ kfree(dev);
+ }
+
+ bpf_map_area_free(dtab->netdev_map);
+ }
+
+ free_percpu(dtab->flush_list);
+ kfree(dtab);
+}
+
+static int dev_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ u32 index = key ? *(u32 *)key : U32_MAX;
+ u32 *next = next_key;
+
+ if (index >= dtab->map.max_entries) {
+ *next = 0;
+ return 0;
+ }
+
+ if (index == dtab->map.max_entries - 1)
+ return -ENOENT;
+ *next = index + 1;
+ return 0;
+}
+
+struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ struct hlist_head *head = dev_map_index_hash(dtab, key);
+ struct bpf_dtab_netdev *dev;
+
+ hlist_for_each_entry_rcu(dev, head, index_hlist,
+ lockdep_is_held(&dtab->index_lock))
+ if (dev->idx == key)
+ return dev;
+
+ return NULL;
+}
+
+static int dev_map_hash_get_next_key(struct bpf_map *map, void *key,
+ void *next_key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ u32 idx, *next = next_key;
+ struct bpf_dtab_netdev *dev, *next_dev;
+ struct hlist_head *head;
+ int i = 0;
+
+ if (!key)
+ goto find_first;
+
+ idx = *(u32 *)key;
+
+ dev = __dev_map_hash_lookup_elem(map, idx);
+ if (!dev)
+ goto find_first;
+
+ next_dev = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&dev->index_hlist)),
+ struct bpf_dtab_netdev, index_hlist);
+
+ if (next_dev) {
+ *next = next_dev->idx;
+ return 0;
+ }
+
+ i = idx & (dtab->n_buckets - 1);
+ i++;
+
+ find_first:
+ for (; i < dtab->n_buckets; i++) {
+ head = dev_map_index_hash(dtab, i);
+
+ next_dev = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
+ struct bpf_dtab_netdev,
+ index_hlist);
+ if (next_dev) {
+ *next = next_dev->idx;
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
+static int bq_xmit_all(struct xdp_bulk_queue *bq, u32 flags)
+{
+ struct bpf_dtab_netdev *obj = bq->obj;
+ struct net_device *dev = obj->dev;
+ int sent = 0, drops = 0, err = 0;
+ int i;
+
+ if (unlikely(!bq->count))
+ return 0;
+
+ for (i = 0; i < bq->count; i++) {
+ struct xdp_frame *xdpf = bq->q[i];
+
+ prefetch(xdpf);
+ }
+
+ sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, flags);
+ if (sent < 0) {
+ err = sent;
+ sent = 0;
+ goto error;
+ }
+ drops = bq->count - sent;
+out:
+ bq->count = 0;
+
+ 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);
+ return 0;
+error:
+ /* If ndo_xdp_xmit fails with an errno, no frames have been
+ * xmit'ed and it's our responsibility to them free all.
+ */
+ for (i = 0; i < bq->count; i++) {
+ struct xdp_frame *xdpf = bq->q[i];
+
+ xdp_return_frame_rx_napi(xdpf);
+ drops++;
+ }
+ goto out;
+}
+
+/* __dev_map_flush is called from xdp_do_flush_map() which _must_ be signaled
+ * from the driver before returning from its napi->poll() routine. The poll()
+ * routine is called either from busy_poll context or net_rx_action signaled
+ * from NET_RX_SOFTIRQ. Either way the poll routine must complete before the
+ * net device can be torn down. On devmap tear down we ensure the flush list
+ * is empty before completing to ensure all flush operations have completed.
+ */
+void __dev_map_flush(struct bpf_map *map)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ struct list_head *flush_list = this_cpu_ptr(dtab->flush_list);
+ struct xdp_bulk_queue *bq, *tmp;
+
+ rcu_read_lock();
+ list_for_each_entry_safe(bq, tmp, flush_list, flush_node)
+ bq_xmit_all(bq, XDP_XMIT_FLUSH);
+ rcu_read_unlock();
+}
+
+/* rcu_read_lock (from syscall and BPF contexts) ensures that if a delete and/or
+ * update happens in parallel here a dev_put wont happen until after reading the
+ * ifindex.
+ */
+struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ struct bpf_dtab_netdev *obj;
+
+ if (key >= map->max_entries)
+ return NULL;
+
+ obj = READ_ONCE(dtab->netdev_map[key]);
+ return obj;
+}
+
+/* Runs under RCU-read-side, plus in softirq under NAPI protection.
+ * Thus, safe percpu variable access.
+ */
+static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf,
+ struct net_device *dev_rx)
+
+{
+ struct list_head *flush_list = this_cpu_ptr(obj->dtab->flush_list);
+ struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq);
+
+ if (unlikely(bq->count == DEV_MAP_BULK_SIZE))
+ bq_xmit_all(bq, 0);
+
+ /* Ingress dev_rx will be the same for all xdp_frame's in
+ * bulk_queue, because bq stored per-CPU and must be flushed
+ * from net_device drivers NAPI func end.
+ */
+ if (!bq->dev_rx)
+ bq->dev_rx = dev_rx;
+
+ bq->q[bq->count++] = xdpf;
+
+ if (!bq->flush_node.prev)
+ list_add(&bq->flush_node, flush_list);
+
+ return 0;
+}
+
+int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
+ struct net_device *dev_rx)
+{
+ struct net_device *dev = dst->dev;
+ struct xdp_frame *xdpf;
+ int err;
+
+ if (!dev->netdev_ops->ndo_xdp_xmit)
+ return -EOPNOTSUPP;
+
+ err = xdp_ok_fwd_dev(dev, xdp->data_end - xdp->data);
+ if (unlikely(err))
+ return err;
+
+ xdpf = convert_to_xdp_frame(xdp);
+ if (unlikely(!xdpf))
+ return -EOVERFLOW;
+
+ return bq_enqueue(dst, xdpf, dev_rx);
+}
+
+int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
+ struct bpf_prog *xdp_prog)
+{
+ int err;
+
+ err = xdp_ok_fwd_dev(dst->dev, skb->len);
+ if (unlikely(err))
+ return err;
+ skb->dev = dst->dev;
+ generic_xdp_tx(skb, xdp_prog);
+
+ return 0;
+}
+
+static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key);
+ struct net_device *dev = obj ? obj->dev : NULL;
+
+ return dev ? &dev->ifindex : NULL;
+}
+
+static void *dev_map_hash_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_dtab_netdev *obj = __dev_map_hash_lookup_elem(map,
+ *(u32 *)key);
+ struct net_device *dev = obj ? obj->dev : NULL;
+
+ return dev ? &dev->ifindex : NULL;
+}
+
+static void __dev_map_entry_free(struct rcu_head *rcu)
+{
+ struct bpf_dtab_netdev *dev;
+
+ dev = container_of(rcu, struct bpf_dtab_netdev, rcu);
+ free_percpu(dev->bulkq);
+ dev_put(dev->dev);
+ kfree(dev);
+}
+
+static int dev_map_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ struct bpf_dtab_netdev *old_dev;
+ u32 k = *(u32 *)key;
+
+ if (k >= map->max_entries)
+ return -EINVAL;
+
+ /* Use call_rcu() here to ensure any rcu critical sections have
+ * completed as well as any flush operations because call_rcu
+ * will wait for preempt-disable region to complete, NAPI in this
+ * context. And additionally, the driver tear down ensures all
+ * soft irqs are complete before removing the net device in the
+ * case of dev_put equals zero.
+ */
+ old_dev = xchg(&dtab->netdev_map[k], NULL);
+ if (old_dev)
+ call_rcu(&old_dev->rcu, __dev_map_entry_free);
+ return 0;
+}
+
+static int dev_map_hash_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ struct bpf_dtab_netdev *old_dev;
+ u32 k = *(u32 *)key;
+ unsigned long flags;
+ int ret = -ENOENT;
+
+ spin_lock_irqsave(&dtab->index_lock, flags);
+
+ old_dev = __dev_map_hash_lookup_elem(map, k);
+ if (old_dev) {
+ dtab->items--;
+ hlist_del_init_rcu(&old_dev->index_hlist);
+ call_rcu(&old_dev->rcu, __dev_map_entry_free);
+ ret = 0;
+ }
+ spin_unlock_irqrestore(&dtab->index_lock, flags);
+
+ return ret;
+}
+
+static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
+ struct bpf_dtab *dtab,
+ u32 ifindex,
+ unsigned int idx)
+{
+ 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;
+ u32 i = *(u32 *)key;
+
+ if (unlikely(map_flags > BPF_EXIST))
+ return -EINVAL;
+ if (unlikely(i >= dtab->map.max_entries))
+ return -E2BIG;
+ if (unlikely(map_flags == BPF_NOEXIST))
+ return -EEXIST;
+
+ if (!ifindex) {
+ dev = NULL;
+ } else {
+ 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
+ * Remembering the driver side flush operation will happen before the
+ * net device is removed.
+ */
+ old_dev = xchg(&dtab->netdev_map[i], dev);
+ if (old_dev)
+ call_rcu(&old_dev->rcu, __dev_map_entry_free);
+
+ 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);
+}
+
+static int __dev_map_hash_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;
+ u32 idx = *(u32 *)key;
+ unsigned long flags;
+ int err = -EEXIST;
+
+ if (unlikely(map_flags > BPF_EXIST || !ifindex))
+ return -EINVAL;
+
+ spin_lock_irqsave(&dtab->index_lock, flags);
+
+ old_dev = __dev_map_hash_lookup_elem(map, idx);
+ if (old_dev && (map_flags & BPF_NOEXIST))
+ goto out_err;
+
+ dev = __dev_map_alloc_node(net, dtab, ifindex, idx);
+ if (IS_ERR(dev)) {
+ err = PTR_ERR(dev);
+ goto out_err;
+ }
+
+ if (old_dev) {
+ hlist_del_rcu(&old_dev->index_hlist);
+ } else {
+ if (dtab->items >= dtab->map.max_entries) {
+ spin_unlock_irqrestore(&dtab->index_lock, flags);
+ call_rcu(&dev->rcu, __dev_map_entry_free);
+ return -E2BIG;
+ }
+ dtab->items++;
+ }
+
+ hlist_add_head_rcu(&dev->index_hlist,
+ dev_map_index_hash(dtab, idx));
+ spin_unlock_irqrestore(&dtab->index_lock, flags);
+
+ if (old_dev)
+ call_rcu(&old_dev->rcu, __dev_map_entry_free);
+
+ return 0;
+
+out_err:
+ spin_unlock_irqrestore(&dtab->index_lock, flags);
+ return err;
+}
+
+static int dev_map_hash_update_elem(struct bpf_map *map, void *key, void *value,
+ u64 map_flags)
+{
+ return __dev_map_hash_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,
+ .map_get_next_key = dev_map_get_next_key,
+ .map_lookup_elem = dev_map_lookup_elem,
+ .map_update_elem = dev_map_update_elem,
+ .map_delete_elem = dev_map_delete_elem,
+ .map_check_btf = map_check_no_btf,
+};
+
+const struct bpf_map_ops dev_map_hash_ops = {
+ .map_alloc = dev_map_alloc,
+ .map_free = dev_map_free,
+ .map_get_next_key = dev_map_hash_get_next_key,
+ .map_lookup_elem = dev_map_hash_lookup_elem,
+ .map_update_elem = dev_map_hash_update_elem,
+ .map_delete_elem = dev_map_hash_delete_elem,
+ .map_check_btf = map_check_no_btf,
+};
+
+static void dev_map_hash_remove_netdev(struct bpf_dtab *dtab,
+ struct net_device *netdev)
+{
+ unsigned long flags;
+ u32 i;
+
+ spin_lock_irqsave(&dtab->index_lock, flags);
+ for (i = 0; i < dtab->n_buckets; i++) {
+ struct bpf_dtab_netdev *dev;
+ struct hlist_head *head;
+ struct hlist_node *next;
+
+ head = dev_map_index_hash(dtab, i);
+
+ hlist_for_each_entry_safe(dev, next, head, index_hlist) {
+ if (netdev != dev->dev)
+ continue;
+
+ dtab->items--;
+ hlist_del_rcu(&dev->index_hlist);
+ call_rcu(&dev->rcu, __dev_map_entry_free);
+ }
+ }
+ spin_unlock_irqrestore(&dtab->index_lock, flags);
+}
+
+static int dev_map_notification(struct notifier_block *notifier,
+ ulong event, void *ptr)
+{
+ struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+ struct bpf_dtab *dtab;
+ int i;
+
+ switch (event) {
+ case NETDEV_UNREGISTER:
+ /* This rcu_read_lock/unlock pair is needed because
+ * dev_map_list is an RCU list AND to ensure a delete
+ * operation does not free a netdev_map entry while we
+ * are comparing it against the netdev being unregistered.
+ */
+ rcu_read_lock();
+ list_for_each_entry_rcu(dtab, &dev_map_list, list) {
+ if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
+ dev_map_hash_remove_netdev(dtab, netdev);
+ continue;
+ }
+
+ for (i = 0; i < dtab->map.max_entries; i++) {
+ struct bpf_dtab_netdev *dev, *odev;
+
+ dev = READ_ONCE(dtab->netdev_map[i]);
+ if (!dev || netdev != dev->dev)
+ continue;
+ odev = cmpxchg(&dtab->netdev_map[i], dev, NULL);
+ if (dev == odev)
+ call_rcu(&dev->rcu,
+ __dev_map_entry_free);
+ }
+ }
+ rcu_read_unlock();
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block dev_map_notifier = {
+ .notifier_call = dev_map_notification,
+};
+
+static int __init dev_map_init(void)
+{
+ /* 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);
+ return 0;
+}
+
+subsys_initcall(dev_map_init);