pskb_may_pull should be used to check if skb->data has enough space,
skb->len can not ensure that.
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
when netif_rx() is done, the netif_rx handled skb maybe be freed,
and should not be used.
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All functions used struct vport *vport except
ovs_vport_find_upcall_portid.
This fixes 1 kerneldoc warning
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
s/sock/gs
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For each Rx frame the eTSEC writes its FCS (Frame Check Sequence)
to the Rx buffer.
The eTSEC h/w manual states in the "Receive Buffer Descriptor Field
Descriptions" table:
"Data length is the number of octets written by the eTSEC into this BD's
data buffer if L is cleared (the value is equal to MRBLR), or, if L is
set, the length of the frame including *CRC*, FCB (if RCTRL[PRSDEP > 00),
preamble (if MACCFG2[PreAmRxEn]=1), time stamp (if RCTRL[TS] = 1) and
any padding (RCTRL[PAL])."
Though the FCS bytes are removed by the driver before passing the skb
to the net stack, the Rx buffer size computation does not currently
take into account the FCS bytes (4 bytes).
Because the Rx buffer size is multiple of 512 bytes, leaving out the
FCS is not a problem for the default MTU of 1500, as the Rx buffer size
is 1536 in this case. However, for custom MTUs, where the difference
between the MTU size and the Rx buffer size is less, this can be a
problem as the computed Rx buffer size won't be enough to accomodate
the FCS for a received frame that is big enough (close to MTU size).
In such case the received frame is considered to be incomplete (L flag
not set in the RxBD status) and silently dropped.
Note that the driver does not currently support S/G on Rx, so it has to
compute its Rx buffer size based on the MTU of the device.
Reported-by: Kristian Otnes <kotnes@cisco.com>
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 0b725a2ca6
net: Remove ndo_xmit_flush netdev operation, use signalling instead.
added code that looks at skb->xmit_more after the skb has
been put in TX VQ. Since some paths process the ring and free the skb
immediately, this can cause use after free.
Fix by storing xmit_more in a local variable.
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
iMX6SX IEEE 1588 module has one hw issue in capturing the ATVR register.
The current SW flow is:
ENET0->ATCR |= ENET_ATCR_CAPTURE_MASK;
ts_counter_ns = ENET0->ATVR;
The ATVR value is not expected value that cause LinuxPTP stack cannot be convergent.
ENET Block Guide/ Chapter for the iMX6SX (PELE) address the issue:
After set ENET_ATCR[Capture], there need some time cycles before the counter
value is capture in the register clock domain. The wait-time-cycles is at least
6 clock cycles of the slower clock between the register clock and the 1588 clock.
So need something like:
ENET0->ATCR |= ENET_ATCR_CAPTURE_MASK;
wait();
ts_counter_ns = ENET0->ATVR;
For iMX6SX, the 1588 ts_clk is fixed to 25Mhz, register clock is 66Mhz, so the
wait-time-cycles must be greater than 240ns (40ns * 6). The patch add 1us delay
before cpu read ATVR register.
Changes V2:
Modify the commit/comments log to describe the issue clearly.
Signed-off-by: Fugang Duan <B38611@freescale.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Identified by kbuild test robot. csk family is always set to be AF_INET or
AF_INET6, so skb will always be initialized to some value but there is no harm
in silencing the warning anyways.
Signed-off-by: Anish Bhatt <anish@chelsio.com>
Fixes : f42bb57c61 ('cxgb4i : Fix -Wunused-function warning')
Signed-off-by: David S. Miller <davem@davemloft.net>
Add ndo_gso_check which a device can define to indicate whether is
is capable of doing GSO on a packet. This funciton would be called from
the stack to determine whether software GSO is needed to be done. A
driver should populate this function if it advertises GSO types for
which there are combinations that it wouldn't be able to handle. For
instance a device that performs UDP tunneling might only implement
support for transparent Ethernet bridging type of inner packets
or might have limitations on lengths of inner headers.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
this patch is to fix the stmmac data compatibilities for
all the SoCs inside the platform file.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Anish Bhatt says:
====================
ipv6 and related cleanup for cxgb4/cxgb4i
This patch set removes some duplicated/extraneous code from cxgb4i, guards
cxgb4 against compilation failure based on ipv6 tristate, make ipv6 related
code no longer be enabled by default irrespective of ipv6 tristate and fixes
a refcnt issue.
-Anish
v2 : Provide more detailed commit messages, make subject more concise as
recommended by Dave Miller.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
There is an extra call to dst_neigh_lookup() leftover in cxgb4i that can cause
an unreleased refcnt issue. Remove extraneous call.
Signed-off-by: Anish Bhatt <anish@chelsio.com>
Fixes : 759a0cc5a3 ('cxgb4i: Add ipv6 code to driver, call into libcxgbi ipv6 api')
Signed-off-by: David S. Miller <davem@davemloft.net>
A bunch of ipv6 related code is left on by default. While this causes no
compilation issues, there is no need to have this enabled by default. Guard
with an ipv6 check, which also takes care of a -Wunused-function warning.
Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cxgb4 ipv6 does not guard against ipv6 being disabled, or the standard
ipv6 module vs inbuilt tri-state issue. This was fixed for cxgb4i & iw_cxgb4
but missed for cxgb4.
Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cxgb4 already handles CLIP updates from a previous changeset for iw_cxgb4,
there is no need to have this functionality in cxgb4i. Remove duplicated code
Signed-off-by: Anish Bhatt <anish@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP Small queues tries to keep number of packets in qdisc
as small as possible, and depends on a tasklet to feed following
packets at TX completion time.
Choice of tasklet was driven by latencies requirements.
Then, TCP stack tries to avoid reorders, by locking flows with
outstanding packets in qdisc in a given TX queue.
What can happen is that many flows get attracted by a low performing
TX queue, and cpu servicing TX completion has to feed packets for all of
them, making this cpu 100% busy in softirq mode.
This became particularly visible with latest skb->xmit_more support
Strategy adopted in this patch is to detect when tcp_wfree() is called
from ksoftirqd and let the outstanding queue for this flow being drained
before feeding additional packets, so that skb->ooo_okay can be set
to allow select_queue() to select the optimal queue :
Incoming ACKS are normally handled by different cpus, so this patch
gives more chance for these cpus to take over the burden of feeding
qdisc with future packets.
Tested:
lpaa23:~# ./super_netperf 1400 --google-pacing-rate 3028000 -H lpaa24 -l 3600 &
lpaa23:~# sar -n DEV 1 10 | grep eth1
06:16:18 AM eth1 595448.00 1190564.00 38381.09 1760253.12 0.00 0.00 1.00
06:16:19 AM eth1 594858.00 1189686.00 38340.76 1758952.72 0.00 0.00 0.00
06:16:20 AM eth1 597017.00 1194019.00 38480.79 1765370.29 0.00 0.00 1.00
06:16:21 AM eth1 595450.00 1190936.00 38380.19 1760805.05 0.00 0.00 0.00
06:16:22 AM eth1 596385.00 1193096.00 38442.56 1763976.29 0.00 0.00 1.00
06:16:23 AM eth1 598155.00 1195978.00 38552.97 1768264.60 0.00 0.00 0.00
06:16:24 AM eth1 594405.00 1188643.00 38312.57 1757414.89 0.00 0.00 1.00
06:16:25 AM eth1 593366.00 1187154.00 38252.16 1755195.83 0.00 0.00 0.00
06:16:26 AM eth1 593188.00 1186118.00 38232.88 1753682.57 0.00 0.00 1.00
06:16:27 AM eth1 596301.00 1192241.00 38440.94 1762733.09 0.00 0.00 0.00
Average: eth1 595457.30 1190843.50 38381.69 1760664.84 0.00 0.00 0.50
lpaa23:~# ./tc -s -d qd sh dev eth1 | grep backlog
backlog 7606336b 2513p requeues 167982
backlog 224072b 74p requeues 566
backlog 581376b 192p requeues 5598
backlog 181680b 60p requeues 1070
backlog 5305056b 1753p requeues 110166 // Here, this TX queue is attracting flows
backlog 157456b 52p requeues 1758
backlog 672216b 222p requeues 3025
backlog 60560b 20p requeues 24541
backlog 448144b 148p requeues 21258
lpaa23:~# echo 1 >/proc/sys/net/ipv4/tcp_tsq_enable_tcp_wfree_ksoftirqd_detect
Immediate jump to full bandwidth, and traffic is properly
shard on all tx queues.
lpaa23:~# sar -n DEV 1 10 | grep eth1
06:16:46 AM eth1 1397632.00 2795397.00 90081.87 4133031.26 0.00 0.00 1.00
06:16:47 AM eth1 1396874.00 2793614.00 90032.99 4130385.46 0.00 0.00 0.00
06:16:48 AM eth1 1395842.00 2791600.00 89966.46 4127409.67 0.00 0.00 1.00
06:16:49 AM eth1 1395528.00 2791017.00 89946.17 4126551.24 0.00 0.00 0.00
06:16:50 AM eth1 1397891.00 2795716.00 90098.74 4133497.39 0.00 0.00 1.00
06:16:51 AM eth1 1394951.00 2789984.00 89908.96 4125022.51 0.00 0.00 0.00
06:16:52 AM eth1 1394608.00 2789190.00 89886.90 4123851.36 0.00 0.00 1.00
06:16:53 AM eth1 1395314.00 2790653.00 89934.33 4125983.09 0.00 0.00 0.00
06:16:54 AM eth1 1396115.00 2792276.00 89984.25 4128411.21 0.00 0.00 1.00
06:16:55 AM eth1 1396829.00 2793523.00 90030.19 4130250.28 0.00 0.00 0.00
Average: eth1 1396158.40 2792297.00 89987.09 4128439.35 0.00 0.00 0.50
lpaa23:~# tc -s -d qd sh dev eth1 | grep backlog
backlog 7900052b 2609p requeues 173287
backlog 878120b 290p requeues 589
backlog 1068884b 354p requeues 5621
backlog 996212b 329p requeues 1088
backlog 984100b 325p requeues 115316
backlog 956848b 316p requeues 1781
backlog 1080996b 357p requeues 3047
backlog 975016b 322p requeues 24571
backlog 990156b 327p requeues 21274
(All 8 TX queues get a fair share of the traffic)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rajesh Borundia says:
====================
qlcnic: Bug fixes
This series fixes following issues.
* We were programming maximum number of arguments supported by
adapter instead of required in a command.
* Destroy tx command requires three arguments instead of two.
Please apply these patches to net.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
o Number of arguments taken by destroy tx command is three
instead of two.
Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
o Initially we were programming maximum number of arguments.
Instead we should program number of arguments required in
a command.
o Maximum number of arguments for 82xx adapter is four. Fix it
for GET_ESWITCH_STATS command.
Signed-off-by: Rajesh Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Resolve "logical 'and' applied to non-boolean constant" warnings"
that appear in W=2 builds by adding !! to a bit test.
Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Unlike normal kfree() it is never right to call sock_kfree_s() with
a NULL pointer, because sock_kfree_s() also has the side effect of
discharging the memory from the sockets quota.
Signed-off-by: David S. Miller <davem@davemloft.net>
It is okay to free a NULL pointer but not okay to mischarge the socket optmem
accounting. Compile test only.
Reported-by: rucsoftsec@gmail.com
Cc: Chien Yen <chien.yen@oracle.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use t4_fw_upgrade instead of t4_load_fw to write firmware into FLASH, since
t4_load_fw doesn't co-ordinate with the firmware and the adapter can get hosed
enough to require a power cycle of the system.
Based on original work by Casey Leedom <leedom@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Giuseppe Cavallaro says:
====================
stmmac: review and fix the dwmac-sti glue-logic
This patch is to review the whole glue logic adopted on STi SoCs that
was bugged.
In the old glue-logic there was a lot of confusion when setup the
retiming especially for STiD127 where, for example, the bits 6 and 7
(in the GMAC control register) have a different meaning of what is
used for STiH4xx SoCs. So we cannot adopt the same glue for all these
SoCs.
Moreover, GiGa on STiD127 didn't work and, for all the SoCs, the RGMII
couldn't run when the speed was 10Mbps (because the clock was not properly
managed).
Note that the phy clock needs to be provided by the platform as well as
documented in the related binding file (updated as consequence).
The old code supported too many configurations never adopted and validated.
This made the code very complex to maintain and debug in case of issues.
The patch simplifies all the configurations as commented in the tables
inside the file and obviously it has been tested on all the boards
based on the SoCs mentioned.
With this patch, the dwmac-sti is also ready to support new configurations that
will be available on next SoC generations.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is to review the whole glue logic adopted on STi SoCs that
was bugged.
In the old glue-logic there was a lot of confusion when setup the
retiming especially for STiD127 where, for example, the bits 6 and 7
(in the GMAC control register) have a different meaning of what is
used for STiH4xx SoCs. So we cannot adopt the same glue for all these
SoCs.
Moreover, GiGa on STiD127 didn't work and, for all the SoCs, the RGMII
couldn't run when the speed was 10Mbps (because the clock was not properly
managed).
Note that the phy clock needs to be provided by the platform as well as
documented in the related binding file (updated as consequence).
The old code supported too many configurations never adopted and validated.
This made the code very complex to maintain and debug in case of issues.
The patch simplifies all the configurations as commented in the tables
inside the file and obviously it has been tested on all the boards
based on the SoCs mentioned.
With this patch, the dwmac-sti is also ready to support new configurations that
will be available on next SoC generations.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds the missing compatibility to the STiH407 SoC.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On several STi platforms: e.g. stihxxx-b2120 an Ethernet switch is
embedded and connected to the stmmac via RGMII mode. So this is managed
by using the FIXED_PHY. In that case, the support in the platform needs
to be fixed to allow the stmmac to dialog with the switch via fixed-link
by using phy_bus_name property.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tag_protocol is now an enum, so drivers have to check against it.
Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Iyappan Subramanian says:
====================
Adding SGMII based 1GbE basic support to APM X-Gene SoC ethernet driver.
v2: Address comments from v1
* Split the patchset into two, the first one being preparatory patch
* Added link_state function pointer to the xgene_mac_ops structure
* Added xgene_indirect_ctl structure for indirect read/write arguments
v1:
* Initial version
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: Keyur Chudgar <kchudgar@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: Keyur Chudgar <kchudgar@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- Added link_state function pointer to the xgene__mac_ops structure
- Moved ring manager (pdata->rm) assignment to xgene_enet_setup_ops
- Removed unused variable (pdata->phy_addr) and macro (FULL_DUPLEX)
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: Keyur Chudgar <kchudgar@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: Keyur Chudgar <kchudgar@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
userspace programs that use eBPF instruction macros need to include two files:
uapi/linux/filter.h and uapi/linux/bpf.h
Move common macro definitions that are shared between classic BPF and eBPF
into uapi/linux/bpf_common.h, so that user app can include only one bpf.h file
Cc: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
parent cfusbl was used instead of first structure member 'layer'
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
remove all the child devices from the system to make sure that re-insert of
cpsw module doesn't fail on child device populated by of_platform_populate().
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
memories allocated with devm_* apis must not be freed with kfree apis,
so removing the kfree calls
Fixes: e194312854 ('drivers: net: davinci_cpdma: Convert kzalloc() to devm_kzalloc().')
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ring TX doorbell only if xmit_more is not set or the queue is stopped.
Suggested-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Prashant Sreedharan <prashant@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fib_nh_match does not match nexthops correctly. Example:
ip route add 172.16.10/24 nexthop via 192.168.122.12 dev eth0 \
nexthop via 192.168.122.13 dev eth0
ip route del 172.16.10/24 nexthop via 192.168.122.14 dev eth0 \
nexthop via 192.168.122.15 dev eth0
Del command is successful and route is removed. After this patch
applied, the route is correctly matched and result is:
RTNETLINK answers: No such process
Please consider this for stable trees as well.
Fixes: 4e902c5741 ("[IPv4]: FIB configuration using struct fib_config")
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We worked hard to improve tcp_ack() performance, by not accessing
skb_shinfo() in fast path (cd7d8498c9 tcp: change tcp_skb_pcount()
location)
We still have one spurious access because of ACK timestamping,
added in commit e1c8a607b2 ("net-timestamp: ACK timestamp for
bytestreams")
By checking if sk_tsflags has SOF_TIMESTAMPING_TX_ACK set,
we can avoid two cache line misses for the common case.
While we are at it, add two prefetchw() :
One in tcp_ack() to bring skb at the head of write queue.
One in tcp_clean_rtx_queue() loop to bring following skb,
as we will delete skb from the write queue and dirty skb->next->prev.
Add a couple of [un]likely() clauses.
After this patch, tcp_ack() is no longer the most consuming
function in tcp stack.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Van Jacobson <vanj@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tilman Schmidt says:
====================
Coverity patches for drivers/isdn
Here's a series of patches for the ISDN CAPI subsystem and the
Gigaset ISDN driver.
Patches 1 to 7 are specific fixes for Coverity warnings.
Patches 8 to 11 fix related problems with the handling of invalid
CAPI command codes I noticed while working on this.
Patch 12 fixes an unrelated problem I noticed during the subsequent
regression tests.
It would be great if these could still be merged.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
In usb_gigaset function gigaset_write_cmd(), the length field of
the command buffer structure could be cleared by the transmit
tasklet before it was used for the function's return value.
Fix by copying to a local variable before scheduling the tasklet.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
capi_cmd2str() is used in many places to build log messages.
None of them is prepared to handle NULL as a result.
Change the function to return printable string "INVALID_COMMAND"
instead.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Have callers of capi_cmsg2message and capi_message2cmsg handle
non-zero return values indicating failure.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
An invalid CAPI 2.0 command/subcommand combination may retrieve a
NULL pointer from the cpars[] array which will later be dereferenced
by the parser routines.
Fix by adding NULL pointer checks in strategic places.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
Encapsulate accesses to the CAPI 2.0 command/subcommand name and
parameter tables in a single place in preparation for redesign.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
The result of the function command_2_index() is used to index two
arrays mnames[] and cpars[] with max. index 0x4e but in its current
form that function can produce results up to 3*(0x9+0x9)+0x7f =
0xb5.
Fix by clamping all result values potentially overrunning the arrays
to zero which is already handled as an invalid value.
Re-spotted with Coverity.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
