It seems I forgot to add handling of devmap_hash type maps to the device
unregister hook for devmaps. This omission causes devices to not be
properly released, which causes hangs.
Fix this by adding the missing handler.
Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
---
kernel/bpf/devmap.c | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index d27f3b60ff6d..deb9416341e9 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -719,6 +719,35 @@ const struct bpf_map_ops dev_map_hash_ops = {
.map_check_btf = map_check_no_btf,
};
+static void dev_map_hash_remove_netdev(struct bpf_dtab *dtab,
+ struct net_device *netdev)
+{
+ int i;
+
+ for (i = 0; i < dtab->n_buckets; i++) {
+ struct bpf_dtab_netdev *dev, *odev;
+ struct hlist_head *head;
+
+ head = dev_map_index_hash(dtab, i);
+ dev = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
+ struct bpf_dtab_netdev,
+ index_hlist);
+
+ while (dev) {
+ odev = (netdev == dev->dev) ? dev : NULL;
+ dev = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&dev->index_hlist)),
+ struct bpf_dtab_netdev,
+ index_hlist);
+
+ if (odev) {
+ hlist_del_rcu(&odev->index_hlist);
+ call_rcu(&odev->rcu,
+ __dev_map_entry_free);
+ }
+ }
+ }
+}
+
static int dev_map_notification(struct notifier_block *notifier,
ulong event, void *ptr)
{
@@ -735,6 +764,11 @@ static int dev_map_notification(struct notifier_block *notifier,
*/
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;
--
2.23.0
