Commits · 7de4344f2abbaeda5c62211a8314dbd5da2bac6c · Kirill Smelkov / linux

28 Oct, 2019 7 commits

net: dpaa2: Use the correct style for SPDX License Identifier · 7de4344f

Nishad Kamdar authored Oct 24, 2019

This patch corrects the SPDX License Identifier style in
header files related to DPAA2 Ethernet driver supporting
Freescale SoCs with DPAA2. For C header files
Documentation/process/license-rules.rst mandates C-like comments
(opposed to C source files where C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7de4344f

Merge branch 'net-avoid-KCSAN-splats' · 20243058

David S. Miller authored Oct 28, 2019

Eric Dumazet says:

====================
net: avoid KCSAN splats

Often times we use skb_queue_empty() without holding a lock,
meaning that other cpus (or interrupt) can change the queue
under us. This is fine, but we need to properly annotate
the lockless intent to make sure the compiler wont over
optimize things.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

20243058

net: add READ_ONCE() annotation in __skb_wait_for_more_packets() · 7c422d0c

Eric Dumazet authored Oct 23, 2019

__skb_wait_for_more_packets() can be called while other cpus
can feed packets to the socket receive queue.

KCSAN reported :

BUG: KCSAN: data-race in __skb_wait_for_more_packets / __udp_enqueue_schedule_skb

write to 0xffff888102e40b58 of 8 bytes by interrupt on cpu 0:
 __skb_insert include/linux/skbuff.h:1852 [inline]
 __skb_queue_before include/linux/skbuff.h:1958 [inline]
 __skb_queue_tail include/linux/skbuff.h:1991 [inline]
 __udp_enqueue_schedule_skb+0x2d7/0x410 net/ipv4/udp.c:1470
 __udp_queue_rcv_skb net/ipv4/udp.c:1940 [inline]
 udp_queue_rcv_one_skb+0x7bd/0xc70 net/ipv4/udp.c:2057
 udp_queue_rcv_skb+0xb5/0x400 net/ipv4/udp.c:2074
 udp_unicast_rcv_skb.isra.0+0x7e/0x1c0 net/ipv4/udp.c:2233
 __udp4_lib_rcv+0xa44/0x17c0 net/ipv4/udp.c:2300
 udp_rcv+0x2b/0x40 net/ipv4/udp.c:2470
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955

read to 0xffff888102e40b58 of 8 bytes by task 13035 on cpu 1:
 __skb_wait_for_more_packets+0xfa/0x320 net/core/datagram.c:100
 __skb_recv_udp+0x374/0x500 net/ipv4/udp.c:1683
 udp_recvmsg+0xe1/0xb10 net/ipv4/udp.c:1712
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec+0x5c/0x70 net/socket.c:871
 ___sys_recvmsg+0x1a0/0x3e0 net/socket.c:2480
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2601
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2680
 __do_sys_recvmmsg net/socket.c:2703 [inline]
 __se_sys_recvmmsg net/socket.c:2696 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2696
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13035 Comm: syz-executor.3 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7c422d0c

net: use skb_queue_empty_lockless() in busy poll contexts · 3f926af3

Eric Dumazet authored Oct 23, 2019

Busy polling usually runs without locks.
Let's use skb_queue_empty_lockless() instead of skb_queue_empty()

Also uses READ_ONCE() in __skb_try_recv_datagram() to address
a similar potential problem.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3f926af3

net: use skb_queue_empty_lockless() in poll() handlers · 3ef7cf57

Eric Dumazet authored Oct 23, 2019

Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3ef7cf57

udp: use skb_queue_empty_lockless() · 137a0dbe

Eric Dumazet authored Oct 23, 2019

syzbot reported a data-race [1].

We should use skb_queue_empty_lockless() to document that we are
not ensuring a mutual exclusion and silence KCSAN.

[1]
BUG: KCSAN: data-race in __skb_recv_udp / __udp_enqueue_schedule_skb

write to 0xffff888122474b50 of 8 bytes by interrupt on cpu 0:
 __skb_insert include/linux/skbuff.h:1852 [inline]
 __skb_queue_before include/linux/skbuff.h:1958 [inline]
 __skb_queue_tail include/linux/skbuff.h:1991 [inline]
 __udp_enqueue_schedule_skb+0x2c1/0x410 net/ipv4/udp.c:1470
 __udp_queue_rcv_skb net/ipv4/udp.c:1940 [inline]
 udp_queue_rcv_one_skb+0x7bd/0xc70 net/ipv4/udp.c:2057
 udp_queue_rcv_skb+0xb5/0x400 net/ipv4/udp.c:2074
 udp_unicast_rcv_skb.isra.0+0x7e/0x1c0 net/ipv4/udp.c:2233
 __udp4_lib_rcv+0xa44/0x17c0 net/ipv4/udp.c:2300
 udp_rcv+0x2b/0x40 net/ipv4/udp.c:2470
 ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
 process_backlog+0x1d3/0x420 net/core/dev.c:5955

read to 0xffff888122474b50 of 8 bytes by task 8921 on cpu 1:
 skb_queue_empty include/linux/skbuff.h:1494 [inline]
 __skb_recv_udp+0x18d/0x500 net/ipv4/udp.c:1653
 udp_recvmsg+0xe1/0xb10 net/ipv4/udp.c:1712
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec+0x5c/0x70 net/socket.c:871
 ___sys_recvmsg+0x1a0/0x3e0 net/socket.c:2480
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2601
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2680
 __do_sys_recvmmsg net/socket.c:2703 [inline]
 __se_sys_recvmmsg net/socket.c:2696 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2696
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8921 Comm: syz-executor.4 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

137a0dbe

net: add skb_queue_empty_lockless() · d7d16a89

Eric Dumazet authored Oct 23, 2019

Some paths call skb_queue_empty() without holding
the queue lock. We must use a barrier in order
to not let the compiler do strange things, and avoid
KCSAN splats.

Adding a barrier in skb_queue_empty() might be overkill,
I prefer adding a new helper to clearly identify
points where the callers might be lockless. This might
help us finding real bugs.

The corresponding WRITE_ONCE() should add zero cost
for current compilers.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

d7d16a89

27 Oct, 2019 2 commits

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf · fc11078d

David S. Miller authored Oct 27, 2019

Pablo Neira Ayuso says:

====================
Netfilter/IPVS fixes for net

The following patchset contains Netfilter/IPVS fixes for net:

1) Fix crash on flowtable due to race between garbage collection
   and insertion.

2) Restore callback unbinding in netfilter offloads.

3) Fix races on IPVS module removal, from Davide Caratti.

4) Make old_secure_tcp per-netns to fix sysbot report,
   from Eric Dumazet.

5) Validate matching length in netfilter offloads, from wenxu.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

fc11078d

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf · 1a51a474

David S. Miller authored Oct 26, 2019

Daniel Borkmann says:

====================
pull-request: bpf 2019-10-27

The following pull-request contains BPF updates for your *net* tree.

We've added 7 non-merge commits during the last 11 day(s) which contain
a total of 7 files changed, 66 insertions(+), 16 deletions(-).

The main changes are:

1) Fix two use-after-free bugs in relation to RCU in jited symbol exposure to
   kallsyms, from Daniel Borkmann.

2) Fix NULL pointer dereference in AF_XDP rx-only sockets, from Magnus Karlsson.

3) Fix hang in netdev unregister for hash based devmap as well as another overflow
   bug on 32 bit archs in memlock cost calculation, from Toke Høiland-Jørgensen.

4) Fix wrong memory access in LWT BPF programs on reroute due to invalid dst.
   Also fix BPF selftests to use more compatible nc options, from Jiri Benc.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

1a51a474

26 Oct, 2019 11 commits

Merge branch 'ipv4-fix-route-update-on-metric-change' · 45f33806

David S. Miller authored Oct 26, 2019

Paolo Abeni says:

====================
ipv4: fix route update on metric change.

This fixes connected route update on some edge cases for ip addr metric
change.
It additionally includes self tests for the covered scenarios. The new tests
fail on unpatched kernels and pass on the patched one.

v1 -> v2:
 - add selftests
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

45f33806

selftests: fib_tests: add more tests for metric update · 37de3b35

Paolo Abeni authored Oct 26, 2019

This patch adds two more tests to ipv4_addr_metric_test() to
explicitly cover the scenarios fixed by the previous patch.
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

37de3b35

ipv4: fix route update on metric change. · 0b834ba0

Paolo Abeni authored Oct 26, 2019

Since commit af4d768a ("net/ipv4: Add support for specifying metric
of connected routes"), when updating an IP address with a different metric,
the associated connected route is updated, too.

Still, the mentioned commit doesn't handle properly some corner cases:

$ ip addr add dev eth0 192.168.1.0/24
$ ip addr add dev eth0 192.168.2.1/32 peer 192.168.2.2
$ ip addr add dev eth0 192.168.3.1/24
$ ip addr change dev eth0 192.168.1.0/24 metric 10
$ ip addr change dev eth0 192.168.2.1/32 peer 192.168.2.2 metric 10
$ ip addr change dev eth0 192.168.3.1/24 metric 10
$ ip -4 route
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.0
192.168.2.2 dev eth0 proto kernel scope link src 192.168.2.1
192.168.3.0/24 dev eth0 proto kernel scope link src 192.168.2.1 metric 10

Only the last route is correctly updated.

The problem is the current test in fib_modify_prefix_metric():

	if (!(dev->flags & IFF_UP) ||
	    ifa->ifa_flags & (IFA_F_SECONDARY | IFA_F_NOPREFIXROUTE) ||
	    ipv4_is_zeronet(prefix) ||
	    prefix == ifa->ifa_local || ifa->ifa_prefixlen == 32)

Which should be the logical 'not' of the pre-existing test in
fib_add_ifaddr():

	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) &&
	    (prefix != addr || ifa->ifa_prefixlen < 32))

To properly negate the original expression, we need to change the last
logical 'or' to a logical 'and'.

Fixes: af4d768a ("net/ipv4: Add support for specifying metric of connected routes")
Reported-and-suggested-by: Beniamino Galvani <bgalvani@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

0b834ba0

net: Zeroing the structure ethtool_wolinfo in ethtool_get_wol() · 5ff223e8

zhanglin authored Oct 26, 2019

memset() the structure ethtool_wolinfo that has padded bytes
but the padded bytes have not been zeroed out.
Signed-off-by: zhanglin <zhang.lin16@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

5ff223e8

Merge tag 'ipvs-fixes-for-v5.4' of https://git.kernel.org/pub/scm/linux/kernel/git/horms/ipvs · 52b33b4f

Pablo Neira Ayuso authored Oct 26, 2019

Simon Horman says:

====================
IPVS fixes for v5.4

* Eric Dumazet resolves a race condition in switching the defense level
* Davide Caratti resolves a race condition in module removal
====================
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

52b33b4f

cxgb4: request the TX CIDX updates to status page · 7c3bebc3

Raju Rangoju authored Oct 23, 2019

For adapters which support the SGE Doorbell Queue Timer facility,
we configured the Ethernet TX Queues to send CIDX Updates to the
Associated Ethernet RX Response Queue with CPL_SGE_EGR_UPDATE
messages to allow us to respond more quickly to the CIDX Updates.
But, this was adding load to PCIe Link RX bandwidth and,
potentially, resulting in higher CPU Interrupt load.

This patch requests the HW to deliver the CIDX updates to the TX
queue status page rather than generating an ingress queue message
(as an interrupt). With this patch, the load on RX bandwidth is
reduced and a substantial improvement in BW is noticed at lower
IO sizes.

Fixes: d429005f ("cxgb4/cxgb4vf: Add support for SGE doorbell queue timer")
Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7c3bebc3

netns: fix GFP flags in rtnl_net_notifyid() · d4e4fdf9

Guillaume Nault authored Oct 23, 2019

In rtnl_net_notifyid(), we certainly can't pass a null GFP flag to
rtnl_notify(). A GFP_KERNEL flag would be fine in most circumstances,
but there are a few paths calling rtnl_net_notifyid() from atomic
context or from RCU critical sections. The later also precludes the use
of gfp_any() as it wouldn't detect the RCU case. Also, the nlmsg_new()
call is wrong too, as it uses GFP_KERNEL unconditionally.

Therefore, we need to pass the GFP flags as parameter and propagate it
through function calls until the proper flags can be determined.

In most cases, GFP_KERNEL is fine. The exceptions are:
  * openvswitch: ovs_vport_cmd_get() and ovs_vport_cmd_dump()
    indirectly call rtnl_net_notifyid() from RCU critical section,

  * rtnetlink: rtmsg_ifinfo_build_skb() already receives GFP flags as
    parameter.

Also, in ovs_vport_cmd_build_info(), let's change the GFP flags used
by nlmsg_new(). The function is allowed to sleep, so better make the
flags consistent with the ones used in the following
ovs_vport_cmd_fill_info() call.

Found by code inspection.

Fixes: 9a963454 ("netns: notify netns id events")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

d4e4fdf9

net: ethernet: Use the correct style for SPDX License Identifier · 16d65287

Nishad Kamdar authored Oct 23, 2019

This patch corrects the SPDX License Identifier style in
header file related to ethernet driver for Cortina Gemini
devices. For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

16d65287

Merge branch 'smc-fixes' · 31af5057

David S. Miller authored Oct 25, 2019

Karsten Graul says:

====================
net/smc: fixes for -net

Fixes for the net tree, covering a memleak when closing
SMC fallback sockets and fix SMC-R connection establishment
when vlan-ids are used.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

31af5057

net/smc: keep vlan_id for SMC-R in smc_listen_work() · ca5f8d2d

Ursula Braun authored Oct 23, 2019

Creating of an SMC-R connection with vlan-id fails, because
smc_listen_work() determines the vlan_id of the connection,
saves it in struct smc_init_info ini, but clears the ini area
again if SMC-D is not applicable.
This patch just resets the ISM device before investigating
SMC-R availability.

Fixes: bc36d2fc ("net/smc: consolidate function parameters")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ca5f8d2d

net/smc: fix closing of fallback SMC sockets · f536dffc

Ursula Braun authored Oct 23, 2019

For SMC sockets forced to fallback to TCP, the file is propagated
from the outer SMC to the internal TCP socket. When closing the SMC
socket, the internal TCP socket file pointer must be restored to the
original NULL value, otherwise memory leaks may show up (found with
CONFIG_DEBUG_KMEMLEAK).

The internal TCP socket is released in smc_clcsock_release(), which
calls __sock_release() function in net/socket.c. This calls the
needed iput(SOCK_INODE(sock)) only, if the file pointer has been reset
to the original NULL-value.

Fixes: 07603b23 ("net/smc: propagate file from SMC to TCP socket")
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

f536dffc

25 Oct, 2019 3 commits

net: hwbm: if CONFIG_NET_HWBM unset, make stub functions static · 91e2e576

Ben Dooks (Codethink) authored Oct 23, 2019

If CONFIG_NET_HWBM is not set, then these stub functions in
<net/hwbm.h> should be declared static to avoid trying to
export them from any driver that includes this.

Fixes the following sparse warnings:

./include/net/hwbm.h:24:6: warning: symbol 'hwbm_buf_free' was not declared. Should it be static?
./include/net/hwbm.h:25:5: warning: symbol 'hwbm_pool_refill' was not declared. Should it be static?
./include/net/hwbm.h:26:5: warning: symbol 'hwbm_pool_add' was not declared. Should it be static?
Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

91e2e576

net: mvneta: make stub functions static inline · 3f6b2c44

Ben Dooks (Codethink) authored Oct 23, 2019

If the CONFIG_MVNET_BA is not set, then make the stub functions
static inline to avoid trying to export them, and remove hte
following sparse warnings:

drivers/net/ethernet/marvell/mvneta_bm.h:163:6: warning: symbol 'mvneta_bm_pool_destroy' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:165:6: warning: symbol 'mvneta_bm_bufs_free' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:167:5: warning: symbol 'mvneta_bm_construct' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:168:5: warning: symbol 'mvneta_bm_pool_refill' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:170:23: warning: symbol 'mvneta_bm_pool_use' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:181:18: warning: symbol 'mvneta_bm_get' was not declared. Should it be static?
drivers/net/ethernet/marvell/mvneta_bm.h:182:6: warning: symbol 'mvneta_bm_put' was not declared. Should it be static?
Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

3f6b2c44

net: sch_generic: Use pfifo_fast as fallback scheduler for CAN hardware · fa784f2a

Vincent Prince authored Oct 22, 2019

There is networking hardware that isn't based on Ethernet for layers 1 and 2.

For example CAN.

CAN is a multi-master serial bus standard for connecting Electronic Control
Units [ECUs] also known as nodes. A frame on the CAN bus carries up to 8 bytes
of payload. Frame corruption is detected by a CRC. However frame loss due to
corruption is possible, but a quite unusual phenomenon.

While fq_codel works great for TCP/IP, it doesn't for CAN. There are a lot of
legacy protocols on top of CAN, which are not build with flow control or high
CAN frame drop rates in mind.

When using fq_codel, as soon as the queue reaches a certain delay based length,
skbs from the head of the queue are silently dropped. Silently meaning that the
user space using a send() or similar syscall doesn't get an error. However
TCP's flow control algorithm will detect dropped packages and adjust the
bandwidth accordingly.

When using fq_codel and sending raw frames over CAN, which is the common use
case, the user space thinks the package has been sent without problems, because
send() returned without an error. pfifo_fast will drop skbs, if the queue
length exceeds the maximum. But with this scheduler the skbs at the tail are
dropped, an error (-ENOBUFS) is propagated to user space. So that the user
space can slow down the package generation.

On distributions, where fq_codel is made default via CONFIG_DEFAULT_NET_SCH
during compile time, or set default during runtime with sysctl
net.core.default_qdisc (see [1]), we get a bad user experience. In my test case
with pfifo_fast, I can transfer thousands of million CAN frames without a frame
drop. On the other hand with fq_codel there is more then one lost CAN frame per
thousand frames.

As pointed out fq_codel is not suited for CAN hardware, so this patch changes
attach_one_default_qdisc() to use pfifo_fast for "ARPHRD_CAN" network devices.

During transition of a netdev from down to up state the default queuing
discipline is attached by attach_default_qdiscs() with the help of
attach_one_default_qdisc(). This patch modifies attach_one_default_qdisc() to
attach the pfifo_fast (pfifo_fast_ops) if the network device type is
"ARPHRD_CAN".

[1] https://github.com/systemd/systemd/issues/9194Signed-off-by: Vincent Prince <vincent.prince.fr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

fa784f2a

24 Oct, 2019 17 commits

Merge branch 'net-fix-nested-device-bugs' · 65921376

David S. Miller authored Oct 24, 2019

Taehee Yoo says:

====================
net: fix nested device bugs

This patchset fixes several bugs that are related to nesting
device infrastructure.
Current nesting infrastructure code doesn't limit the depth level of
devices. nested devices could be handled recursively. at that moment,
it needs huge memory and stack overflow could occur.
Below devices type have same bug.
VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, and VXLAN.
But I couldn't test all interface types so there could be more device
types, which have similar problems.
Maybe qmi_wwan.c code could have same problem.
So, I would appreciate if someone test qmi_wwan.c and other modules.

Test commands:
    ip link add dummy0 type dummy
    ip link add vlan1 link dummy0 type vlan id 1

    for i in {2..100}
    do
	    let A=$i-1
	    ip link add name vlan$i link vlan$A type vlan id $i
    done
    ip link del dummy0

1st patch actually fixes the root cause.
It adds new common variables {upper/lower}_level that represent
depth level. upper_level variable is depth of upper devices.
lower_level variable is depth of lower devices.

      [U][L]       [U][L]
vlan1  1  5  vlan4  1  4
vlan2  2  4  vlan5  2  3
vlan3  3  3    |
  |            |
  +------------+
  |
vlan6  4  2
dummy0 5  1

After this patch, the nesting infrastructure code uses this variable to
check the depth level.

2nd patch fixes Qdisc lockdep related problem.
Before this patch, devices use static lockdep map.
So, if devices that are same types are nested, lockdep will warn about
recursive situation.
These patches make these devices use dynamic lockdep key instead of
static lock or subclass.

3rd patch fixes unexpected IFF_BONDING bit unset.
When nested bonding interface scenario, bonding interface could lost it's
IFF_BONDING flag. This should not happen.
This patch adds a condition before unsetting IFF_BONDING.

4th patch fixes nested locking problem in bonding interface
Bonding interface has own lock and this uses static lock.
Bonding interface could be nested and it uses same lockdep key.
So that unexisting lockdep warning occurs.

5th patch fixes nested locking problem in team interface
Team interface has own lock and this uses static lock.
Team interface could be nested and it uses same lockdep key.
So that unexisting lockdep warning occurs.

6th patch fixes a refcnt leak in the macsec module.
When the macsec module is unloaded, refcnt leaks occur.
But actually, that holding refcnt is unnecessary.
So this patch just removes these code.

7th patch adds ignore flag to an adjacent structure.
In order to exchange an adjacent node safely, ignore flag is needed.

8th patch makes vxlan add an adjacent link to limit depth level.
Vxlan interface could set it's lower interface and these lower interfaces
are handled recursively.
So, if the depth of lower interfaces is too deep, stack overflow could
happen.

9th patch removes unnecessary variables and callback.
After 1st patch, subclass callback and variables are unnecessary.
This patch just removes these variables and callback.

10th patch fix refcnt leaks in the virt_wifi module
Like every nested interface, the upper interface should be deleted
before the lower interface is deleted.
In order to fix this, the notifier routine is added in this patch.

v4 -> v5 :
 - Update log messages
 - Move variables position, 1st patch
 - Fix iterator routine, 1st patch
 - Add generic lockdep key code, which replaces 2, 4, 5, 6, 7 patches.
 - Log message update, 10th patch
 - Fix wrong error value in error path of __init routine, 10th patch
 - hold module refcnt when interface is created, 10th patch
v3 -> v4 :
 - Add new 12th patch to fix refcnt leaks in the virt_wifi module
 - Fix wrong usage netdev_upper_dev_link() in the vxlan.c
 - Preserve reverse christmas tree variable ordering in the vxlan.c
 - Add missing static keyword in the dev.c
 - Expose netdev_adjacent_change_{prepare/commit/abort} instead of
   netdev_adjacent_dev_{enable/disable}
v2 -> v3 :
 - Modify nesting infrastructure code to use iterator instead of recursive.
v1 -> v2 :
 - Make the 3rd patch do not add a new priv_flag.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

65921376