linux/net/xdp, branch v5.3-rc4

xdp: fix potential deadlock on socket mutex

2019-07-12T13:02:21Z

There are 2 call chains: a) xsk_bind --> xdp_umem_assign_dev b) unregister_netdevice_queue --> xsk_notifier with the following locking order: a) xs->mutex --> rtnl_lock b) rtnl_lock --> xdp.lock --> xs->mutex Different order of taking 'xs->mutex' and 'rtnl_lock' could produce a deadlock here. Fix that by moving the 'rtnl_lock' before 'xs->lock' in the bind call chain (a). Reported-by: syzbot+bf64ec93de836d7f4c2c@syzkaller.appspotmail.com Fixes: 455302d1c9ae ("xdp: fix hang while unregistering device bound to xdp socket") Signed-off-by: Ilya Maximets Acked-by: Jonathan Lemon Signed-off-by: Daniel Borkmann

xdp: fix possible cq entry leak

2019-07-12T12:54:57Z

Completion queue address reservation could not be undone. In case of bad 'queue_id' or skb allocation failure, reserved entry will be leaked reducing the total capacity of completion queue. Fix that by moving reservation to the point where failure is not possible. Additionally, 'queue_id' checking moved out from the loop since there is no point to check it there. Fixes: 35fcde7f8deb ("xsk: support for Tx") Signed-off-by: Ilya Maximets Acked-by: Björn Töpel Tested-by: William Tu Signed-off-by: Daniel Borkmann

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-07-09T02:48:57Z

Two cases of overlapping changes, nothing fancy. Signed-off-by: David S. Miller

xdp: fix race on generic receive path

2019-07-08T23:43:26Z

Unlike driver mode, generic xdp receive could be triggered by different threads on different CPU cores at the same time leading to the fill and rx queue breakage. For example, this could happen while sending packets from two processes to the first interface of veth pair while the second part of it is open with AF_XDP socket. Need to take a lock for each generic receive to avoid race. Fixes: c497176cb2e4 ("xsk: add Rx receive functions and poll support") Signed-off-by: Ilya Maximets Acked-by: Magnus Karlsson Tested-by: William Tu Signed-off-by: Daniel Borkmann

xdp: fix hang while unregistering device bound to xdp socket

2019-07-03T13:10:55Z

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 Acked-by: Jonathan Lemon Signed-off-by: Daniel Borkmann

xdp: hold device for umem regardless of zero-copy mode

2019-07-03T13:10:55Z

Device pointer stored in umem regardless of zero-copy mode, so we heed to hold the device in all cases. Fixes: c9b47cc1fabc ("xsk: fix bug when trying to use both copy and zero-copy on one queue id") Signed-off-by: Ilya Maximets Acked-by: Jonathan Lemon Signed-off-by: Daniel Borkmann

xsk: Return the whole xdp_desc from xsk_umem_consume_tx

2019-06-27T20:53:27Z

Some drivers want to access the data transmitted in order to implement acceleration features of the NICs. It is also useful in AF_XDP TX flow. Change the xsk_umem_consume_tx API to return the whole xdp_desc, that contains the data pointer, length and DMA address, instead of only the latter two. Adapt the implementation of i40e and ixgbe to this change. Signed-off-by: Maxim Mikityanskiy Signed-off-by: Tariq Toukan Acked-by: Saeed Mahameed Cc: Björn Töpel Cc: Magnus Karlsson Acked-by: Björn Töpel Signed-off-by: Daniel Borkmann

xsk: Add getsockopt XDP_OPTIONS

2019-06-27T20:53:26Z

Make it possible for the application to determine whether the AF_XDP socket is running in zero-copy mode. To achieve this, add a new getsockopt option XDP_OPTIONS that returns flags. The only flag supported for now is the zero-copy mode indicator. Signed-off-by: Maxim Mikityanskiy Signed-off-by: Tariq Toukan Acked-by: Saeed Mahameed Acked-by: Björn Töpel Signed-off-by: Daniel Borkmann

xsk: Add API to check for available entries in FQ

2019-06-27T20:53:26Z

Add a function that checks whether the Fill Ring has the specified amount of descriptors available. It will be useful for mlx5e that wants to check in advance, whether it can allocate a bulk of RX descriptors, to get the best performance. Signed-off-by: Maxim Mikityanskiy Signed-off-by: Tariq Toukan Acked-by: Saeed Mahameed Acked-by: Björn Töpel Signed-off-by: Daniel Borkmann

xsk: Properly terminate assignment in xskq_produce_flush_desc

2019-06-26T12:39:05Z

Clang warns: In file included from net/xdp/xsk_queue.c:10: net/xdp/xsk_queue.h:292:2: warning: expression result unused [-Wunused-value] WRITE_ONCE(q->ring->producer, q->prod_tail); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:284:6: note: expanded from macro 'WRITE_ONCE' __u.__val; \ ~~~ ^~~~~ 1 warning generated. The q->prod_tail assignment has a comma at the end, not a semi-colon. Fix that so clang no longer warns and everything works as expected. Fixes: c497176cb2e4 ("xsk: add Rx receive functions and poll support") Link: https://github.com/ClangBuiltLinux/linux/issues/544 Signed-off-by: Nathan Chancellor Acked-by: Nick Desaulniers Acked-by: Jonathan Lemon Acked-by: Björn Töpel Acked-by: Song Liu Signed-off-by: Daniel Borkmann