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path: root/drivers/net/tun.c (follow)
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2018-06-04Allow ethtool to change tun link settingsChas Williams1-2/+25
Let user space set whatever it would like to advertise for the tun interface. Preserve the existing defaults. Signed-off-by: Chas Williams <3chas3@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-03tun: implement flush flag for ndo_xdp_xmitJesper Dangaard Brouer1-6/+13
When passed the XDP_XMIT_FLUSH flag tun_xdp_xmit now performs the same kind of socket wake up as in tun_xdp_flush(). The wake up code from tun_xdp_flush is generalized and shared with tun_xdp_xmit. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-06-03xdp: add flags argument to ndo_xdp_xmit APIJesper Dangaard Brouer1-2/+6
This patch only change the API and reject any use of flags. This is an intermediate step that allows us to implement the flush flag operation later, for each individual driver in a separate patch. The plan is to implement flush operation via XDP_XMIT_FLUSH flag and then remove XDP_XMIT_FLAGS_NONE when done. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-06-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-6/+9
Filling in the padding slot in the bpf structure as a bug fix in 'ne' overlapped with actually using that padding area for something in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-29tun: Fix NULL pointer dereference in XDP redirectToshiaki Makita1-6/+9
Calling XDP redirection requires bh disabled. Softirq can call another XDP function and redirection functions, then the percpu static variable ri->map can be overwritten to NULL. This is a generic XDP case called from tun. [ 3535.736058] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 3535.743974] PGD 0 P4D 0 [ 3535.746530] Oops: 0000 [#1] SMP PTI [ 3535.750049] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm ipmi_ssif irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel crypto_simd cryptd enclosure hpwdt hpilo glue_helper ipmi_si pcspkr wmi mei_me ioatdma mei ipmi_devintf shpchp dca ipmi_msghandler lpc_ich acpi_power_meter sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm smartpqi i40e crc32c_intel scsi_transport_sas tg3 i2c_core ptp pps_core [ 3535.813456] CPU: 5 PID: 1630 Comm: vhost-1614 Not tainted 4.17.0-rc4 #2 [ 3535.820127] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 3535.828732] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 3535.833740] RSP: 0018:ffffb4bc47bf7c58 EFLAGS: 00010246 [ 3535.839009] RAX: ffff9fdfcfea1c40 RBX: 0000000000000000 RCX: ffff9fdf27fe3100 [ 3535.846205] RDX: ffff9fdfca769200 RSI: 0000000000000000 RDI: 0000000000000000 [ 3535.853402] RBP: ffffb4bc491d9000 R08: 00000000000045ad R09: 0000000000000ec0 [ 3535.860597] R10: 0000000000000001 R11: ffff9fdf26c3ce4e R12: ffff9fdf9e72c000 [ 3535.867794] R13: 0000000000000000 R14: fffffffffffffff2 R15: ffff9fdfc82cdd00 [ 3535.874990] FS: 0000000000000000(0000) GS:ffff9fdfcfe80000(0000) knlGS:0000000000000000 [ 3535.883152] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3535.888948] CR2: 0000000000000018 CR3: 0000000bde724004 CR4: 00000000007626e0 [ 3535.896145] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 3535.903342] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 3535.910538] PKRU: 55555554 [ 3535.913267] Call Trace: [ 3535.915736] xdp_do_generic_redirect+0x7a/0x310 [ 3535.920310] do_xdp_generic.part.117+0x285/0x370 [ 3535.924970] tun_get_user+0x5b9/0x1260 [tun] [ 3535.929279] tun_sendmsg+0x52/0x70 [tun] [ 3535.933237] handle_tx+0x2ad/0x5f0 [vhost_net] [ 3535.937721] vhost_worker+0xa5/0x100 [vhost] [ 3535.942030] kthread+0xf5/0x130 [ 3535.945198] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 3535.950031] ? kthread_bind+0x10/0x10 [ 3535.953727] ret_from_fork+0x35/0x40 [ 3535.957334] Code: 0e 74 15 83 f8 10 75 05 e9 49 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 29 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 49 a9 b3 ff 31 c0 c3 [ 3535.976387] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffffb4bc47bf7c58 [ 3535.982883] CR2: 0000000000000018 [ 3535.987096] ---[ end trace 383b299dd1430240 ]--- [ 3536.131325] Kernel panic - not syncing: Fatal exception [ 3536.137484] Kernel Offset: 0x26a00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 3536.281406] ---[ end Kernel panic - not syncing: Fatal exception ]--- And a kernel with generic case fixed still panics in tun driver XDP redirect, because it disabled only preemption, but not bh. [ 2055.128746] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 [ 2055.136662] PGD 0 P4D 0 [ 2055.139219] Oops: 0000 [#1] SMP PTI [ 2055.142736] Modules linked in: vhost_net vhost tap tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter sunrpc vfat fat ext4 mbcache jbd2 intel_rapl skx_edac nfit libnvdimm x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc ses aesni_intel ipmi_ssif crypto_simd enclosure cryptd hpwdt glue_helper ioatdma hpilo wmi dca pcspkr ipmi_si acpi_power_meter ipmi_devintf shpchp mei_me ipmi_msghandler mei lpc_ich sch_fq_codel ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm i40e smartpqi tg3 scsi_transport_sas crc32c_intel i2c_core ptp pps_core [ 2055.206142] CPU: 6 PID: 1693 Comm: vhost-1683 Tainted: G W 4.17.0-rc5-fix-tun+ #1 [ 2055.215011] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 11/14/2017 [ 2055.223617] RIP: 0010:__xdp_map_lookup_elem+0x5/0x30 [ 2055.228624] RSP: 0018:ffff998b07607cc0 EFLAGS: 00010246 [ 2055.233892] RAX: ffff8dbd8e235700 RBX: ffff8dbd8ff21c40 RCX: 0000000000000004 [ 2055.241089] RDX: ffff998b097a9000 RSI: 0000000000000000 RDI: 0000000000000000 [ 2055.248286] RBP: 0000000000000000 R08: 00000000000065a8 R09: 0000000000005d80 [ 2055.255483] R10: 0000000000000040 R11: ffff8dbcf0100000 R12: ffff998b097a9000 [ 2055.262681] R13: ffff8dbd8c98c000 R14: 0000000000000000 R15: ffff998b07607d78 [ 2055.269879] FS: 0000000000000000(0000) GS:ffff8dbd8ff00000(0000) knlGS:0000000000000000 [ 2055.278039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2055.283834] CR2: 0000000000000018 CR3: 0000000c0c8cc005 CR4: 00000000007626e0 [ 2055.291030] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2055.298227] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2055.305424] PKRU: 55555554 [ 2055.308153] Call Trace: [ 2055.310624] xdp_do_redirect+0x7b/0x380 [ 2055.314499] tun_get_user+0x10fe/0x12a0 [tun] [ 2055.318895] tun_sendmsg+0x52/0x70 [tun] [ 2055.322852] handle_tx+0x2ad/0x5f0 [vhost_net] [ 2055.327337] vhost_worker+0xa5/0x100 [vhost] [ 2055.331646] kthread+0xf5/0x130 [ 2055.334813] ? vhost_dev_ioctl+0x3b0/0x3b0 [vhost] [ 2055.339646] ? kthread_bind+0x10/0x10 [ 2055.343343] ret_from_fork+0x35/0x40 [ 2055.346950] Code: 0e 74 15 83 f8 10 75 05 e9 e9 aa b3 ff f3 c3 0f 1f 80 00 00 00 00 f3 c3 e9 c9 9d b3 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 18 83 f8 0e 74 0d 83 f8 10 75 05 e9 e9 a9 b3 ff 31 c0 c3 [ 2055.366004] RIP: __xdp_map_lookup_elem+0x5/0x30 RSP: ffff998b07607cc0 [ 2055.372500] CR2: 0000000000000018 [ 2055.375856] ---[ end trace 2a2dcc5e9e174268 ]--- [ 2055.523626] Kernel panic - not syncing: Fatal exception [ 2055.529796] Kernel Offset: 0x2e000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 2055.677539] ---[ end Kernel panic - not syncing: Fatal exception ]--- v2: - Removed preempt_disable/enable since local_bh_disable will prevent preemption as well, feedback from Jason Wang. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-4/+15
Lots of easy overlapping changes in the confict resolutions here. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller1-13/+24
Alexei Starovoitov says: ==================== pull-request: bpf-next 2018-05-24 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Björn Töpel cleans up AF_XDP (removes rebind, explicit cache alignment from uapi, etc). 2) David Ahern adds mtu checks to bpf_ipv{4,6}_fib_lookup() helpers. 3) Jesper Dangaard Brouer adds bulking support to ndo_xdp_xmit. 4) Jiong Wang adds support for indirect and arithmetic shifts to NFP 5) Martin KaFai Lau cleans up BTF uapi and makes the btf_header extensible. 6) Mathieu Xhonneux adds an End.BPF action to seg6local with BPF helpers allowing to edit/grow/shrink a SRH and apply on a packet generic SRv6 actions. 7) Sandipan Das adds support for bpf2bpf function calls in ppc64 JIT. 8) Yonghong Song adds BPF_TASK_FD_QUERY command for introspection of tracing events. 9) other misc fixes from Gustavo A. R. Silva, Sirio Balmelli, John Fastabend, and Magnus Karlsson ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-24xdp: change ndo_xdp_xmit API to support bulkingJesper Dangaard Brouer1-13/+24
This patch change the API for ndo_xdp_xmit to support bulking xdp_frames. When kernel is compiled with CONFIG_RETPOLINE, XDP sees a huge slowdown. Most of the slowdown is caused by DMA API indirect function calls, but also the net_device->ndo_xdp_xmit() call. Benchmarked patch with CONFIG_RETPOLINE, using xdp_redirect_map with single flow/core test (CPU E5-1650 v4 @ 3.60GHz), showed performance improved: for driver ixgbe: 6,042,682 pps -> 6,853,768 pps = +811,086 pps for driver i40e : 6,187,169 pps -> 6,724,519 pps = +537,350 pps With frames avail as a bulk inside the driver ndo_xdp_xmit call, further optimizations are possible, like bulk DMA-mapping for TX. Testing without CONFIG_RETPOLINE show the same performance for physical NIC drivers. The virtual NIC driver tun sees a huge performance boost, as it can avoid doing per frame producer locking, but instead amortize the locking cost over the bulk. V2: Fix compile errors reported by kbuild test robot <lkp@intel.com> V4: Isolated ndo, driver changes and callers. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-23tuntap: correctly set SOCKWQ_ASYNC_NOSPACEJason Wang1-4/+15
When link is down, writes to the device might fail with -EIO. Userspace needs an indication when the status is resolved. As a fix, tun_net_open() attempts to wake up writers - but that is only effective if SOCKWQ_ASYNC_NOSPACE has been set in the past. This is not the case of vhost_net which only poll for EPOLLOUT after it meets errors during sendmsg(). This patch fixes this by making sure SOCKWQ_ASYNC_NOSPACE is set when socket is not writable or device is down to guarantee EPOLLOUT will be raised in either tun_chr_poll() or tun_sock_write_space() after device is up. Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Eric Dumazet <edumazet@google.com> Fixes: 1bd4978a88ac2 ("tun: honor IFF_UP in tun_get_user()") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-15/+12
S390 bpf_jit.S is removed in net-next and had changes in 'net', since that code isn't used any more take the removal. TLS data structures split the TX and RX components in 'net-next', put the new struct members from the bug fix in 'net' into the RX part. The 'net-next' tree had some reworking of how the ERSPAN code works in the GRE tunneling code, overlapping with a one-line headroom calculation fix in 'net'. Overlapping changes in __sock_map_ctx_update_elem(), keep the bits that read the prog members via READ_ONCE() into local variables before using them. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-16tuntap: fix use after free during releaseJason Wang1-1/+1
After commit b196d88aba8a ("tun: fix use after free for ptr_ring") we need clean up tx ring during release(). But unfortunately, it tries to do the cleanup blindly after socket were destroyed which will lead another use-after-free. Fix this by doing the cleanup before dropping the last reference of the socket in __tun_detach(). Reported-by: Andrei Vagin <avagin@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Fixes: b196d88aba8a ("tun: fix use after free for ptr_ring") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-14tun: fix use after free for ptr_ringJason Wang1-15/+12
We used to initialize ptr_ring during TUNSETIFF, this is because its size depends on the tx_queue_len of netdevice. And we try to clean it up when socket were detached from netdevice. A race were spotted when trying to do uninit during a read which will lead a use after free for pointer ring. Solving this by always initialize a zero size ptr_ring in open() and do resizing during TUNSETIFF, and then we can safely do cleanup during close(). With this, there's no need for the workaround that was introduced by commit 4df0bfc79904 ("tun: fix a memory leak for tfile->tx_array"). Reported-by: syzbot+e8b902c3c3fadf0a9dba@syzkaller.appspotmail.com Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Michael S. Tsirkin <mst@redhat.com> Fixes: 1576d9860599 ("tun: switch to use skb array for tx") Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-10tun: Do SIOCGSKNS out of rtnl_lock()Kirill Tkhai1-11/+7
Since net ns of tun device is assigned on the device creation, and it never changes, we do not need to use any lock to get it from alive tun. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-6/+1
Conflicts were simple overlapping changes in microchip driver. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller1-1/+2
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-04-21 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Initial work on BPF Type Format (BTF) is added, which is a meta data format which describes the data types of BPF programs / maps. BTF has its roots from CTF (Compact C-Type format) with a number of changes to it. First use case is to provide a generic pretty print capability for BPF maps inspection, later work will also add BTF to bpftool. pahole support to convert dwarf to BTF will be upstreamed as well (https://github.com/iamkafai/pahole/tree/btf), from Martin. 2) Add a new xdp_bpf_adjust_tail() BPF helper for XDP that allows for changing the data_end pointer. Only shrinking is currently supported which helps for crafting ICMP control messages. Minor changes in drivers have been added where needed so they recalc the packet's length also when data_end was adjusted, from Nikita. 3) Improve bpftool to make it easier to feed hex bytes via cmdline for map operations, from Quentin. 4) Add support for various missing BPF prog types and attach types that have been added to kernel recently but neither to bpftool nor libbpf yet. Doc and bash completion updates have been added as well for bpftool, from Andrey. 5) Proper fix for avoiding to leak info stored in frame data on page reuse for the two bpf_xdp_adjust_{head,meta} helpers by disallowing to move the pointers into struct xdp_frame area, from Jesper. 6) Follow-up compile fix from BTF in order to include stdbool.h in libbpf, from Björn. 7) Few fixes in BPF sample code, that is, a typo on the netdevice in a comment and fixup proper dump of XDP action code in the tracepoint exception, from Wang and Jesper. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-20tun: do not compute the rxhash, if not neededPaolo Abeni1-9/+6
Currently, the tun driver, in absence of an eBPF steering program, always compute the rxhash in its rx path, even when such value is later unused due to additional checks ( This changeset moves the all the related checks just before the __skb_get_hash_symmetric(), so that the latter is no more computed when unneeded. Also replace an unneeded RCU section with rcu_access_pointer(). Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-18bpf: make tun compatible w/ bpf_xdp_adjust_tailNikita V. Shirokov1-1/+2
w/ bpf_xdp_adjust_tail helper xdp's data_end pointer could be changed as well (only "decrease" of pointer's location is going to be supported). changing of this pointer will change packet's size. for tun driver we need to adjust XDP_PASS handling by recalculating length of the packet if it was passed to the TCP/IP stack (in case if after xdp's prog run data_end pointer was adjusted) Reviewed-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-18tun: fix vlan packet truncationBjørn Mork1-6/+1
Bogus trimming in tun_net_xmit() causes truncated vlan packets. skb->len is correct whether or not skb_vlan_tag_present() is true. There is no more reason to adjust the skb length on xmit in this driver than any other driver. tun_put_user() adds 4 bytes to the total for tagged packets because it transmits the tag inline to userspace. This is similar to a nic transmitting the tag inline on the wire. Reproducing the bug by sending any tagged packet through back-to-back connected tap interfaces: socat TUN,tun-type=tap,iff-up,tun-name=in TUN,tun-type=tap,iff-up,tun-name=out & ip link add link in name in.20 type vlan id 20 ip addr add 10.9.9.9/24 dev in.20 ip link set in.20 up tshark -nxxi in -f arp -c1 2>/dev/null & tshark -nxxi out -f arp -c1 2>/dev/null & ping -c 1 10.9.9.5 >/dev/null 2>&1 The output from the 'in' and 'out' interfaces are different when the bug is present: Capturing on 'in' 0000 ff ff ff ff ff ff 76 cf 76 37 d5 0a 81 00 00 14 ......v.v7...... 0010 08 06 00 01 08 00 06 04 00 01 76 cf 76 37 d5 0a ..........v.v7.. 0020 0a 09 09 09 00 00 00 00 00 00 0a 09 09 05 .............. Capturing on 'out' 0000 ff ff ff ff ff ff 76 cf 76 37 d5 0a 81 00 00 14 ......v.v7...... 0010 08 06 00 01 08 00 06 04 00 01 76 cf 76 37 d5 0a ..........v.v7.. 0020 0a 09 09 09 00 00 00 00 00 00 .......... Fixes: aff3d70a07ff ("tun: allow to attach ebpf socket filter") Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Bjørn Mork <bjorn@mork.no> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17xdp: transition into using xdp_frame for ndo_xdp_xmitJesper Dangaard Brouer1-7/+12
Changing API ndo_xdp_xmit to take a struct xdp_frame instead of struct xdp_buff. This brings xdp_return_frame and ndp_xdp_xmit in sync. This builds towards changing the API further to become a bulk API, because xdp_buff is not a queue-able object while xdp_frame is. V4: Adjust for commit 59655a5b6c83 ("tuntap: XDP_TX can use native XDP") V7: Adjust for commit d9314c474d4f ("i40e: add support for XDP_REDIRECT") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17xdp: transition into using xdp_frame for return APIJesper Dangaard Brouer1-2/+2
Changing API xdp_return_frame() to take struct xdp_frame as argument, seems like a natural choice. But there are some subtle performance details here that needs extra care, which is a deliberate choice. When de-referencing xdp_frame on a remote CPU during DMA-TX completion, result in the cache-line is change to "Shared" state. Later when the page is reused for RX, then this xdp_frame cache-line is written, which change the state to "Modified". This situation already happens (naturally) for, virtio_net, tun and cpumap as the xdp_frame pointer is the queued object. In tun and cpumap, the ptr_ring is used for efficiently transferring cache-lines (with pointers) between CPUs. Thus, the only option is to de-referencing xdp_frame. It is only the ixgbe driver that had an optimization, in which it can avoid doing the de-reference of xdp_frame. The driver already have TX-ring queue, which (in case of remote DMA-TX completion) have to be transferred between CPUs anyhow. In this data area, we stored a struct xdp_mem_info and a data pointer, which allowed us to avoid de-referencing xdp_frame. To compensate for this, a prefetchw is used for telling the cache coherency protocol about our access pattern. My benchmarks show that this prefetchw is enough to compensate the ixgbe driver. V7: Adjust for commit d9314c474d4f ("i40e: add support for XDP_REDIRECT") V8: Adjust for commit bd658dda4237 ("net/mlx5e: Separate dma base address and offset in dma_sync call") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17xdp: rhashtable with allocator ID to pointer mappingJesper Dangaard Brouer1-0/+6
Use the IDA infrastructure for getting a cyclic increasing ID number, that is used for keeping track of each registered allocator per RX-queue xdp_rxq_info. Instead of using the IDR infrastructure, which uses a radix tree, use a dynamic rhashtable, for creating ID to pointer lookup table, because this is faster. The problem that is being solved here is that, the xdp_rxq_info pointer (stored in xdp_buff) cannot be used directly, as the guaranteed lifetime is too short. The info is needed on a (potentially) remote CPU during DMA-TX completion time . In an xdp_frame the xdp_mem_info is stored, when it got converted from an xdp_buff, which is sufficient for the simple page refcnt based recycle schemes. For more advanced allocators there is a need to store a pointer to the registered allocator. Thus, there is a need to guard the lifetime or validity of the allocator pointer, which is done through this rhashtable ID map to pointer. The removal and validity of of the allocator and helper struct xdp_mem_allocator is guarded by RCU. The allocator will be created by the driver, and registered with xdp_rxq_info_reg_mem_model(). It is up-to debate who is responsible for freeing the allocator pointer or invoking the allocator destructor function. In any case, this must happen via RCU freeing. Use the IDA infrastructure for getting a cyclic increasing ID number, that is used for keeping track of each registered allocator per RX-queue xdp_rxq_info. V4: Per req of Jason Wang - Use xdp_rxq_info_reg_mem_model() in all drivers implementing XDP_REDIRECT, even-though it's not strictly necessary when allocator==NULL for type MEM_TYPE_PAGE_SHARED (given it's zero). V6: Per req of Alex Duyck - Introduce rhashtable_lookup() call in later patch V8: Address sparse should be static warnings (from kbuild test robot) Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17tun: convert to use generic xdp_frame and xdp_return_frame APIJesper Dangaard Brouer1-23/+20
The tuntap driver invented it's own driver specific way of queuing XDP packets, by storing the xdp_buff information in the top of the XDP frame data. Convert it over to use the more generic xdp_frame structure. The main problem with the in-driver method is that the xdp_rxq_info pointer cannot be trused/used when dequeueing the frame. V3: Remove check based on feedback from Jason Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11tun: send netlink notification when the device is modifiedSabrina Dubroca1-2/+22
I added dumping of link information about tun devices over netlink in commit 1ec010e70593 ("tun: export flags, uid, gid, queue information over netlink"), but didn't add the missing netlink notifications when the device's exported properties change. This patch adds notifications when owner/group or flags are modified, when queues are attached/detached, and when a tun fd is closed. Reported-by: Thomas Haller <thaller@redhat.com> Fixes: 1ec010e70593 ("tun: export flags, uid, gid, queue information over netlink") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-11tun: set the flags before registering the netdeviceSabrina Dubroca1-3/+6
Otherwise, register_netdevice advertises the creation of the device with the default flags, instead of what the user requested. Reported-by: Thomas Haller <thaller@redhat.com> Fixes: 1ec010e70593 ("tun: export flags, uid, gid, queue information over netlink") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+2
Fun set of conflict resolutions here... For the mac80211 stuff, these were fortunately just parallel adds. Trivially resolved. In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the function phy_disable_interrupts() earlier in the file, whilst in 'net-next' the phy_error() call from this function was removed. In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the 'rt_table_id' member of rtable collided with a bug fix in 'net' that added a new struct member "rt_mtu_locked" which needs to be copied over here. The mlxsw driver conflict consisted of net-next separating the span code and definitions into separate files, whilst a 'net' bug fix made some changes to that moved code. The mlx5 infiniband conflict resolution was quite non-trivial, the RDMA tree's merge commit was used as a guide here, and here are their notes: ==================== Due to bug fixes found by the syzkaller bot and taken into the for-rc branch after development for the 4.17 merge window had already started being taken into the for-next branch, there were fairly non-trivial merge issues that would need to be resolved between the for-rc branch and the for-next branch. This merge resolves those conflicts and provides a unified base upon which ongoing development for 4.17 can be based. Conflicts: drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f9524 (IB/mlx5: Fix cleanup order on unload) added to for-rc and commit b5ca15ad7e61 (IB/mlx5: Add proper representors support) add as part of the devel cycle both needed to modify the init/de-init functions used by mlx5. To support the new representors, the new functions added by the cleanup patch needed to be made non-static, and the init/de-init list added by the representors patch needed to be modified to match the init/de-init list changes made by the cleanup patch. Updates: drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function prototypes added by representors patch to reflect new function names as changed by cleanup patch drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init stage list to match new order from cleanup patch ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-14tuntap: XDP_TX can use native XDPJason Wang1-11/+8
Now we have ndo_xdp_xmit, switch to use it instead of the slow generic XDP TX routine. XDP_TX on TAP gets ~20% improvements from ~1.5Mpps to ~1.8Mpps on 2.60GHz Core(TM) i7-5600U. Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-09vhost_net: examine pointer types during un-producingJason Wang1-1/+2
After commit fc72d1d54dd9 ("tuntap: XDP transmission"), we can actually queueing XDP pointers in the pointer ring, so we should examine the pointer type before freeing the pointer. Fixes: fc72d1d54dd9 ("tuntap: XDP transmission") Reported-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-15/+7
All of the conflicts were cases of overlapping changes. In net/core/devlink.c, we have to make care that the resouce size_params have become a struct member rather than a pointer to such an object. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26tuntap: correctly add the missing XDP flushJason Wang1-0/+1
We don't flush batched XDP packets through xdp_do_flush_map(), this will cause packets stall at TX queue. Consider we don't do XDP on NAPI poll(), the only possible fix is to call xdp_do_flush_map() immediately after xdp_do_redirect(). Note, this in fact won't try to batch packets through devmap, we could address in the future. Reported-by: Christoffer Dall <christoffer.dall@linaro.org> Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26tuntap: disable preemption during XDP processingJason Wang1-0/+6
Except for tuntap, all other drivers' XDP was implemented at NAPI poll() routine in a bh. This guarantees all XDP operation were done at the same CPU which is required by e.g BFP_MAP_TYPE_PERCPU_ARRAY. But for tuntap, we do it in process context and we try to protect XDP processing by RCU reader lock. This is insufficient since CONFIG_PREEMPT_RCU can preempt the RCU reader critical section which breaks the assumption that all XDP were processed in the same CPU. Fixing this by simply disabling preemption during XDP processing. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-26Revert "tuntap: add missing xdp flush"Jason Wang1-15/+0
This reverts commit 762c330d670e3d4b795cf7a8d761866fdd1eef49. The reason is we try to batch packets for devmap which causes calling xdp_do_flush() in the process context. Simply disabling preemption may not work since process may move among processors which lead xdp_do_flush() to miss some flushes on some processors. So simply revert the patch, a follow-up patch will add the xdp flush correctly. Reported-by: Christoffer Dall <christoffer.dall@linaro.org> Fixes: 762c330d670e ("tuntap: add missing xdp flush") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-10/+6
2018-02-16tun: export flags, uid, gid, queue information over netlinkSabrina Dubroca1-0/+56
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tun: fix tun_napi_alloc_frags() frag allocatorEric Dumazet1-10/+6
<Mark Rutland reported> While fuzzing arm64 v4.16-rc1 with Syzkaller, I've been hitting a misaligned atomic in __skb_clone:         atomic_inc(&(skb_shinfo(skb)->dataref)); where dataref doesn't have the required natural alignment, and the atomic operation faults. e.g. i often see it aligned to a single byte boundary rather than a four byte boundary. AFAICT, the skb_shared_info is misaligned at the instant it's allocated in __napi_alloc_skb() __napi_alloc_skb() </end of report> Problem is caused by tun_napi_alloc_frags() using napi_alloc_frag() with user provided seg sizes, leading to other users of this API getting unaligned page fragments. Since we would like to not necessarily add paddings or alignments to the frags that tun_napi_alloc_frags() attaches to the skb, switch to another page frag allocator. As a bonus skb_page_frag_refill() can use GFP_KERNEL allocations, meaning that we can not deplete memory reserves as easily. Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-15tun: Add ioctl() SIOCGSKNS cmd to allow obtaining net ns of tun deviceKirill Tkhai1-2/+14
This patch adds possibility to get tun device's net namespace fd in the same way we allow to do that for sockets. Socket ioctl numbers do not intersect with tun-specific, and there is already SIOCSIFHWADDR used in tun code. So, SIOCGSKNS number is choosen instead of custom-made for this functionality. Note, that open_related_ns() uses plain get_net_ns() and it's safe (net can't be already dead at this moment): tun socket is allocated via sk_alloc() with zero last arg (kern = 0). So, each alive socket increments net::count, and the socket is definitely alive during ioctl syscall. Also, common variable net is introduced, so small cleanup in TUNSETIFF is made. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-6/+6
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-08tuntap: add missing xdp flushJason Wang1-0/+15
When using devmap to redirect packets between interfaces, xdp_do_flush() is usually a must to flush any batched packets. Unfortunately this is missed in current tuntap implementation. Unlike most hardware driver which did XDP inside NAPI loop and call xdp_do_flush() at then end of each round of poll. TAP did it in the context of process e.g tun_get_user(). So fix this by count the pending redirected packets and flush when it exceeds NAPI_POLL_WEIGHT or MSG_MORE was cleared by sendmsg() caller. With this fix, xdp_redirect_map works again between two TAPs. Fixes: 761876c857cb ("tap: XDP support") Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-83/+376
Pull networking updates from David Miller: 1) Significantly shrink the core networking routing structures. Result of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf 2) Add netdevsim driver for testing various offloads, from Jakub Kicinski. 3) Support cross-chip FDB operations in DSA, from Vivien Didelot. 4) Add a 2nd listener hash table for TCP, similar to what was done for UDP. From Martin KaFai Lau. 5) Add eBPF based queue selection to tun, from Jason Wang. 6) Lockless qdisc support, from John Fastabend. 7) SCTP stream interleave support, from Xin Long. 8) Smoother TCP receive autotuning, from Eric Dumazet. 9) Lots of erspan tunneling enhancements, from William Tu. 10) Add true function call support to BPF, from Alexei Starovoitov. 11) Add explicit support for GRO HW offloading, from Michael Chan. 12) Support extack generation in more netlink subsystems. From Alexander Aring, Quentin Monnet, and Jakub Kicinski. 13) Add 1000BaseX, flow control, and EEE support to mvneta driver. From Russell King. 14) Add flow table abstraction to netfilter, from Pablo Neira Ayuso. 15) Many improvements and simplifications to the NFP driver bpf JIT, from Jakub Kicinski. 16) Support for ipv6 non-equal cost multipath routing, from Ido Schimmel. 17) Add resource abstration to devlink, from Arkadi Sharshevsky. 18) Packet scheduler classifier shared filter block support, from Jiri Pirko. 19) Avoid locking in act_csum, from Davide Caratti. 20) devinet_ioctl() simplifications from Al viro. 21) More TCP bpf improvements from Lawrence Brakmo. 22) Add support for onlink ipv6 route flag, similar to ipv4, from David Ahern. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1925 commits) tls: Add support for encryption using async offload accelerator ip6mr: fix stale iterator net/sched: kconfig: Remove blank help texts openvswitch: meter: Use 64-bit arithmetic instead of 32-bit tcp_nv: fix potential integer overflow in tcpnv_acked r8169: fix RTL8168EP take too long to complete driver initialization. qmi_wwan: Add support for Quectel EP06 rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK ipmr: Fix ptrdiff_t print formatting ibmvnic: Wait for device response when changing MAC qlcnic: fix deadlock bug tcp: release sk_frag.page in tcp_disconnect ipv4: Get the address of interface correctly. net_sched: gen_estimator: fix lockdep splat net: macb: Handle HRESP error net/mlx5e: IPoIB, Fix copy-paste bug in flow steering refactoring ipv6: addrconf: break critical section in addrconf_verify_rtnl() ipv6: change route cache aging logic i40e/i40evf: Update DESC_NEEDED value to reflect larger value bnxt_en: cleanup DIM work on device shutdown ...
2018-01-30Merge branch 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-2/+2
Pull poll annotations from Al Viro: "This introduces a __bitwise type for POLL### bitmap, and propagates the annotations through the tree. Most of that stuff is as simple as 'make ->poll() instances return __poll_t and do the same to local variables used to hold the future return value'. Some of the obvious brainos found in process are fixed (e.g. POLLIN misspelled as POLL_IN). At that point the amount of sparse warnings is low and most of them are for genuine bugs - e.g. ->poll() instance deciding to return -EINVAL instead of a bitmap. I hadn't touched those in this series - it's large enough as it is. Another problem it has caught was eventpoll() ABI mess; select.c and eventpoll.c assumed that corresponding POLL### and EPOLL### were equal. That's true for some, but not all of them - EPOLL### are arch-independent, but POLL### are not. The last commit in this series separates userland POLL### values from the (now arch-independent) kernel-side ones, converting between them in the few places where they are copied to/from userland. AFAICS, this is the least disruptive fix preserving poll(2) ABI and making epoll() work on all architectures. As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and it will trigger only on what would've triggered EPOLLWRBAND on other architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered at all on sparc. With this patch they should work consistently on all architectures" * 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits) make kernel-side POLL... arch-independent eventpoll: no need to mask the result of epi_item_poll() again eventpoll: constify struct epoll_event pointers debugging printk in sg_poll() uses %x to print POLL... bitmap annotate poll(2) guts 9p: untangle ->poll() mess ->si_band gets POLL... bitmap stored into a user-visible long field ring_buffer_poll_wait() return value used as return value of ->poll() the rest of drivers/*: annotate ->poll() instances media: annotate ->poll() instances fs: annotate ->poll() instances ipc, kernel, mm: annotate ->poll() instances net: annotate ->poll() instances apparmor: annotate ->poll() instances tomoyo: annotate ->poll() instances sound: annotate ->poll() instances acpi: annotate ->poll() instances crypto: annotate ->poll() instances block: annotate ->poll() instances x86: annotate ->poll() instances ...
2018-01-22tun: avoid calling xdp_rxq_info_unreg() twiceCong Wang1-2/+0
Similarly to tx ring, xdp_rxq_info is only registered when !tfile->detached, so we need to avoid calling xdp_rxq_info_unreg() twice too. The helper tun_cleanup_tx_ring() already checks for this properly, so it is correct to put xdp_rxq_info_unreg() just inside there. Reported-by: syzbot+1c788d7ce0f0888f1d7f@syzkaller.appspotmail.com Fixes: 8565d26bcb2f ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net") Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-22tun: add missing rcu annotationJason Wang1-1/+2
This patch fixes the following sparse warnings: drivers/net/tun.c:2241:15: error: incompatible types in comparison expression (different address spaces) Fixes: cd5681d7d890 ("tuntap: rename struct tun_steering_prog to struct tun_prog") Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-4/+14
The BPF verifier conflict was some minor contextual issue. The TUN conflict was less trivial. Cong Wang fixed a memory leak of tfile->tx_array in 'net'. This is an skb_array. But meanwhile in net-next tun changed tfile->tx_arry into tfile->tx_ring which is a ptr_ring. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17tun: allow to attach ebpf socket filterJason Wang1-4/+34
This patch allows userspace to attach eBPF filter to tun. This will allow to implement VM dataplane filtering in a more efficient way compared to cBPF filter by allowing either qemu or libvirt to attach eBPF filter to tun. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17tuntap: rename struct tun_steering_prog to struct tun_progJason Wang1-16/+16
To be reused by other eBPF program other than queue selection. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-17tun: fix a memory leak for tfile->tx_arrayCong Wang1-2/+13
tfile->tun could be detached before we close the tun fd, via tun_detach_all(), so it should not be used to check for tfile->tx_array. As Jason suggested, we probably have to clean it up unconditionally both in __tun_deatch() and tun_detach_all(), but this requires to check if it is initialized or not. Currently skb_array_cleanup() doesn't have such a check, so I check it in the caller and introduce a helper function, it is a bit ugly but we can always improve it in net-next. Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 1576d9860599 ("tun: switch to use skb array for tx") Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-09tuntap: XDP transmissionJason Wang1-32/+179
This patch implements XDP transmission for TAP. Since we can't create new queues for TAP during XDP set, exist ptr_ring was reused for queuing XDP buffers. To differ xdp_buff from sk_buff, TUN_XDP_FLAG (0x1UL) was encoded into lowest bit of xpd_buff pointer during ptr_ring_produce, and was decoded during consuming. XDP metadata was stored in the headroom of the packet which should work in most of cases since driver usually reserve enough headroom. Very minor changes were done for vhost_net: it just need to peek the length depends on the type of pointer. Tests were done on two Intel E5-2630 2.40GHz machines connected back to back through two 82599ES. Traffic were generated/received through MoonGen/testpmd(rxonly). It reports ~20% improvements when xdp_redirect_map is doing redirection from ixgbe to TAP (from 2.50Mpps to 3.05Mpps) Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-09tun/tap: use ptr_ring instead of skb_arrayJason Wang1-20/+22
This patch switches to use ptr_ring instead of skb_array. This will be used to enqueue different types of pointers by encoding type into lower bits. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-05tun: setup xdp_rxq_infoJesper Dangaard Brouer1-1/+23
Driver hook points for xdp_rxq_info: * reg : tun_attach * unreg: __tun_detach I've done some manual testing of this tun driver, but I would appriciate good review and someone else running their use-case tests, as I'm not 100% sure I understand the tfile->detached semantics. V2: Removed the skb_array_cleanup() call from V1 by request from Jason Wang. Cc: Jason Wang <jasowang@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-08tuntap: fix possible deadlock when fail to register netdevJason Wang1-3/+4
Private destructor could be called when register_netdev() fail with rtnl lock held. This will lead deadlock in tun_free_netdev() who tries to hold rtnl_lock. Fixing this by switching to use spinlock to synchronize. Fixes: 96f84061620c ("tun: add eBPF based queue selection method") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-06tun: avoid unnecessary READ_ONCE in tun_net_xmitWillem de Bruijn1-3/+1
The statement no longer serves a purpose. Commit fa35864e0bb7 ("tuntap: Fix for a race in accessing numqueues") added the ACCESS_ONCE to avoid a race condition with skb_queue_len. Commit 436accebb530 ("tuntap: remove unnecessary sk_receive_queue length check during xmit") removed the affected skb_queue_len check. Commit 96f84061620c ("tun: add eBPF based queue selection method") split the function, reading the field a second time in the callee. The temp variable is now only read once, so just remove it. Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>