xdp: fix hang while unregistering device bound to xdp socket
Device that bound to XDP socket will not have zero refcount until the
userspace application will not close it. This leads to hang inside
'netdev_wait_allrefs()' if device unregistering requested:
# ip link del p1
< hang on recvmsg on netlink socket >
# ps -x | grep ip
5126 pts/0 D+ 0:00 ip link del p1
# journalctl -b
Jun 05 07:19:16 kernel:
unregister_netdevice: waiting for p1 to become free. Usage count = 1
Jun 05 07:19:27 kernel:
unregister_netdevice: waiting for p1 to become free. Usage count = 1
...
Fix that by implementing NETDEV_UNREGISTER event notification handler
to properly clean up all the resources and unref device.
This should also allow socket killing via ss(8) utility.
Fixes: 965a99098443 ("xsk: add support for bind for Rx")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index d074b6d..7da1551 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -61,6 +61,11 @@ struct xdp_sock {
struct xsk_queue *tx ____cacheline_aligned_in_smp;
struct list_head list;
bool zc;
+ enum {
+ XSK_READY = 0,
+ XSK_BOUND,
+ XSK_UNBOUND,
+ } state;
/* Protects multiple processes in the control path */
struct mutex mutex;
/* Mutual exclusion of NAPI TX thread and sendmsg error paths