Commit Graph

190 Commits

Author SHA1 Message Date
Eric W. Biederman 18b37535f8 netpoll: Consolidate neigh_tx processing in service_neigh_queue
Move the bond slave device neigh_tx handling into service_neigh_queue.

In connection with neigh_tx processing remove unnecessary tests of
a NULL netpoll_info.  As the netpoll_poll_dev has already used
and thus verified the existince of the netpoll_info.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:47:23 -04:00
Eric W. Biederman ad8d475244 netpoll: Move netpoll_trap under CONFIG_NETPOLL_TRAP
Now that we no longer need to receive packets to safely drain the
network drivers receive queue move netpoll_trap and netpoll_set_trap
under CONFIG_NETPOLL_TRAP

Making netpoll_trap and netpoll_set_trap noop inline functions
when CONFIG_NETPOLL_TRAP is not set.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:47:22 -04:00
Eric W. Biederman b6bacd550c netpoll: Don't drop all received packets.
Change the strategy of netpoll from dropping all packets received
during netpoll_poll_dev to calling napi poll with a budget of 0
(to avoid processing drivers rx queue), and to ignore packets received
with netif_rx (those will safely be placed on the backlog queue).

All of the netpoll supporting drivers have been reviewed to ensure
either thay use netif_rx or that a budget of 0 is supported by their
napi poll routine and that a budget of 0 will not process the drivers
rx queues.

Not dropping packets makes NETPOLL_RX_DROP unnecesary so it is removed.

npinfo->rx_flags is removed  as rx_flags with just the NETPOLL_RX_ENABLED
flag becomes just a redundant mirror of list_empty(&npinfo->rx_np).

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:47:22 -04:00
Eric W. Biederman ff60763143 netpoll: Add netpoll_rx_processing
Add a helper netpoll_rx_processing that reports when netpoll has
receive side processing to perform.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:47:22 -04:00
Eric W. Biederman e97dc3fcf9 netpoll: Warn if more packets are processed than are budgeted
There is already a warning for this case in the normal netpoll path,
but put a copy here in case how netpoll calls the poll functions
causes a differenet result.

netpoll will shortly call the napi poll routine with a budget 0 to
avoid any rx packets being processed.  As nothing does that today
we may encounter drivers that have problems so a netpoll specific
warning seems desirable.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:47:22 -04:00
Eric W. Biederman eb8143b469 netpoll: Visit all napi handlers in poll_napi
In poll_napi loop through all of the napi handlers even when the
budget falls to 0 to ensure that we process all of the tx_queues, and
so that we continue to call into drivers when our initial budget is 0.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:47:22 -04:00
Eric W. Biederman 9852fbec2c netpoll: Pass budget into poll_napi
This moves the control logic to the top level in netpoll_poll_dev
instead of having it dispersed throughout netpoll_poll_dev,
poll_napi and poll_one_napi.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:47:22 -04:00
Eric W. Biederman b249b51b98 netpoll: move setting of NETPOLL_RX_DROP into netpoll_poll_dev
Today netpoll depends on setting NETPOLL_RX_DROP before networking
drivers receive packets in interrupt context so that the packets can
be dropped.  Move this setting into netpoll_poll_dev from
poll_one_napi so that if ndo_poll_controller happens to receive
packets we will drop the packets on the floor instead of letting the
packets bounce through the networking stack and potentially cause problems.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:47:21 -04:00
Sabrina Dubroca 00fe11b3c6 netpoll: fix netconsole IPv6 setup
Currently, to make netconsole start over IPv6, the source address
needs to be specified. Without a source address, netpoll_parse_options
assumes we're setting up over IPv4 and the destination IPv6 address is
rejected.

Check if the IP version has been forced by a source address before
checking for a version mismatch when parsing the destination address.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-06 21:28:06 -08:00
Joe Perches c62326abac netpoll: Use ether_addr_copy
Use ether_addr_copy instead of memcpy(a, b, ETH_ALEN) to
save some cycles on arm and powerpc.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-21 18:13:05 -08:00
Jason Wang f663dd9aaf net: core: explicitly select a txq before doing l2 forwarding
Currently, the tx queue were selected implicitly in ndo_dfwd_start_xmit(). The
will cause several issues:

- NETIF_F_LLTX were removed for macvlan, so txq lock were done for macvlan
  instead of lower device which misses the necessary txq synchronization for
  lower device such as txq stopping or frozen required by dev watchdog or
  control path.
- dev_hard_start_xmit() was called with NULL txq which bypasses the net device
  watchdog.
- dev_hard_start_xmit() does not check txq everywhere which will lead a crash
  when tso is disabled for lower device.

Fix this by explicitly introducing a new param for .ndo_select_queue() for just
selecting queues in the case of l2 forwarding offload. netdev_pick_tx() was also
extended to accept this parameter and dev_queue_xmit_accel() was used to do l2
forwarding transmission.

With this fixes, NETIF_F_LLTX could be preserved for macvlan and there's no need
to check txq against NULL in dev_hard_start_xmit(). Also there's no need to keep
a dedicated ndo_dfwd_start_xmit() and we can just reuse the code of
dev_queue_xmit() to do the transmission.

In the future, it was also required for macvtap l2 forwarding support since it
provides a necessary synchronization method.

Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: e1000-devel@lists.sourceforge.net
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-10 13:23:08 -05:00
David S. Miller aca5f58f9b netpoll: Fix missing TXQ unlock and and OOPS.
The VLAN tag handling code in netpoll_send_skb_on_dev() has two problems.

1) It exits without unlocking the TXQ.

2) It then tries to queue a NULL skb to npinfo->txq.

Reported-by: Ahmed Tamrawi <atamrawi@iastate.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-02 19:50:52 -05:00
Antonio Quartulli 8fb479a47c netpoll: fix rx_hook() interface by passing the skb
Right now skb->data is passed to rx_hook() even if the skb
has not been linearised and without giving rx_hook() a way
to linearise it.

Change the rx_hook() interface and make it accept the skb
and the offset to the UDP payload as arguments. rx_hook() is
also renamed to rx_skb_hook() to ensure that out of the tree
users notice the API change.

In this way any rx_skb_hook() implementation can perform all
the needed operations to properly (and safely) access the
skb data.

Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-25 19:26:58 -04:00
Nikolay Aleksandrov d0fe8c888b netpoll: fix NULL pointer dereference in netpoll_cleanup
I've been hitting a NULL ptr deref while using netconsole because the
np->dev check and the pointer manipulation in netpoll_cleanup are done
without rtnl and the following sequence happens when having a netconsole
over a vlan and we remove the vlan while disabling the netconsole:
	CPU 1					CPU2
					removes vlan and calls the notifier
enters store_enabled(), calls
netdev_cleanup which checks np->dev
and then waits for rtnl
					executes the netconsole netdev
					release notifier making np->dev
					== NULL and releases rtnl
continues to dereference a member of
np->dev which at this point is == NULL

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-19 14:15:53 -04:00
Sonic Zhang b0dd663b60 netpoll: Should handle ETH_P_ARP other than ETH_P_IP in netpoll_neigh_reply
The received ARP request type in the Ethernet packet head is ETH_P_ARP other than ETH_P_IP.

[ Bug introduced by commit b7394d2429
  ("netpoll: prepare for ipv6") ]

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-12 17:19:14 -04:00
Linus Torvalds 496322bc91 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "This is a re-do of the net-next pull request for the current merge
  window.  The only difference from the one I made the other day is that
  this has Eliezer's interface renames and the timeout handling changes
  made based upon your feedback, as well as a few bug fixes that have
  trickeled in.

  Highlights:

   1) Low latency device polling, eliminating the cost of interrupt
      handling and context switches.  Allows direct polling of a network
      device from socket operations, such as recvmsg() and poll().

      Currently ixgbe, mlx4, and bnx2x support this feature.

      Full high level description, performance numbers, and design in
      commit 0a4db187a9 ("Merge branch 'll_poll'")

      From Eliezer Tamir.

   2) With the routing cache removed, ip_check_mc_rcu() gets exercised
      more than ever before in the case where we have lots of multicast
      addresses.  Use a hash table instead of a simple linked list, from
      Eric Dumazet.

   3) Add driver for Atheros CQA98xx 802.11ac wireless devices, from
      Bartosz Markowski, Janusz Dziedzic, Kalle Valo, Marek Kwaczynski,
      Marek Puzyniak, Michal Kazior, and Sujith Manoharan.

   4) Support reporting the TUN device persist flag to userspace, from
      Pavel Emelyanov.

   5) Allow controlling network device VF link state using netlink, from
      Rony Efraim.

   6) Support GRE tunneling in openvswitch, from Pravin B Shelar.

   7) Adjust SOCK_MIN_RCVBUF and SOCK_MIN_SNDBUF for modern times, from
      Daniel Borkmann and Eric Dumazet.

   8) Allow controlling of TCP quickack behavior on a per-route basis,
      from Cong Wang.

   9) Several bug fixes and improvements to vxlan from Stephen
      Hemminger, Pravin B Shelar, and Mike Rapoport.  In particular,
      support receiving on multiple UDP ports.

  10) Major cleanups, particular in the area of debugging and cookie
      lifetime handline, to the SCTP protocol code.  From Daniel
      Borkmann.

  11) Allow packets to cross network namespaces when traversing tunnel
      devices.  From Nicolas Dichtel.

  12) Allow monitoring netlink traffic via AF_PACKET sockets, in a
      manner akin to how we monitor real network traffic via ptype_all.
      From Daniel Borkmann.

  13) Several bug fixes and improvements for the new alx device driver,
      from Johannes Berg.

  14) Fix scalability issues in the netem packet scheduler's time queue,
      by using an rbtree.  From Eric Dumazet.

  15) Several bug fixes in TCP loss recovery handling, from Yuchung
      Cheng.

  16) Add support for GSO segmentation of MPLS packets, from Simon
      Horman.

  17) Make network notifiers have a real data type for the opaque
      pointer that's passed into them.  Use this to properly handle
      network device flag changes in arp_netdev_event().  From Jiri
      Pirko and Timo Teräs.

  18) Convert several drivers over to module_pci_driver(), from Peter
      Huewe.

  19) tcp_fixup_rcvbuf() can loop 500 times over loopback, just use a
      O(1) calculation instead.  From Eric Dumazet.

  20) Support setting of explicit tunnel peer addresses in ipv6, just
      like ipv4.  From Nicolas Dichtel.

  21) Protect x86 BPF JIT against spraying attacks, from Eric Dumazet.

  22) Prevent a single high rate flow from overruning an individual cpu
      during RX packet processing via selective flow shedding.  From
      Willem de Bruijn.

  23) Don't use spinlocks in TCP md5 signing fast paths, from Eric
      Dumazet.

  24) Don't just drop GSO packets which are above the TBF scheduler's
      burst limit, chop them up so they are in-bounds instead.  Also
      from Eric Dumazet.

  25) VLAN offloads are missed when configured on top of a bridge, fix
      from Vlad Yasevich.

  26) Support IPV6 in ping sockets.  From Lorenzo Colitti.

  27) Receive flow steering targets should be updated at poll() time
      too, from David Majnemer.

  28) Fix several corner case regressions in PMTU/redirect handling due
      to the routing cache removal, from Timo Teräs.

  29) We have to be mindful of ipv4 mapped ipv6 sockets in
      upd_v6_push_pending_frames().  From Hannes Frederic Sowa.

  30) Fix L2TP sequence number handling bugs, from James Chapman."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1214 commits)
  drivers/net: caif: fix wrong rtnl_is_locked() usage
  drivers/net: enic: release rtnl_lock on error-path
  vhost-net: fix use-after-free in vhost_net_flush
  net: mv643xx_eth: do not use port number as platform device id
  net: sctp: confirm route during forward progress
  virtio_net: fix race in RX VQ processing
  virtio: support unlocked queue poll
  net/cadence/macb: fix bug/typo in extracting gem_irq_read_clear bit
  Documentation: Fix references to defunct linux-net@vger.kernel.org
  net/fs: change busy poll time accounting
  net: rename low latency sockets functions to busy poll
  bridge: fix some kernel warning in multicast timer
  sfc: Fix memory leak when discarding scattered packets
  sit: fix tunnel update via netlink
  dt:net:stmmac: Add dt specific phy reset callback support.
  dt:net:stmmac: Add support to dwmac version 3.610 and 3.710
  dt:net:stmmac: Allocate platform data only if its NULL.
  net:stmmac: fix memleak in the open method
  ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
  net: ipv6: fix wrong ping_v6_sendmsg return value
  ...
2013-07-09 18:24:39 -07:00
Andy Shevchenko 4cd5773a2a net: core: move mac_pton() to lib/net_utils.c
Since we have at least one user of this function outside of CONFIG_NET
scope, we have to provide this function independently. The proposed
solution is to move it under lib/net_utils.c with corresponding
configuration variable and select wherever it is needed.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-05 12:00:27 -07:00
Amerigo Wang 00f97da17a netpoll: fix position of network header
Similar to the problem in pktgen, netpoll uses skb_tail_offset()
too, as the code is copied from pktgen.

Also use return values of skb_put() directly, this will simiplify
the code.

Reported-by: Thomas Graf <tgraf@suug.ch>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Daniel Borkmann <dborkmann@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-04 17:37:04 -07:00
Simon Horman 7cc4619005 net, ipv4, ipv6: Correct assignment of skb->network_header to skb->tail
This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer however skb->network_header is now
an offset.

This patch corrects the problem by adding a wrapper to return skb tail as
an offset regardless of the value of NET_SKBUFF_DATA_USES_OFFSET. It seems
that skb->tail that this offset may be more than 64k and some care has been
taken to treat such cases as an error.

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-28 23:49:07 -07:00
dingtianhong da6e378ba9 netpoll: remove return value from netpoll_rx_disable()
The netpoll_rx_disable() will always return 0, it is no use and looks wordy,
so remove the unnecessary code and get rid of it in _dev_open and _dev_close.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-27 23:18:50 -07:00
Dan Carpenter a3dbbc2bab netpoll: inverted down_trylock() test
The return value is reversed from mutex_trylock().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-06 11:06:52 -04:00
Neil Horman bd7c4b604a netpoll: convert mutex into a semaphore
Bart Van Assche recently reported a warning to me:

<IRQ>  [<ffffffff8103d79f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8103d7fa>] warn_slowpath_null+0x1a/0x20
[<ffffffff814761dd>] mutex_trylock+0x16d/0x180
[<ffffffff813968c9>] netpoll_poll_dev+0x49/0xc30
[<ffffffff8136a2d2>] ? __alloc_skb+0x82/0x2a0
[<ffffffff81397715>] netpoll_send_skb_on_dev+0x265/0x410
[<ffffffff81397c5a>] netpoll_send_udp+0x28a/0x3a0
[<ffffffffa0541843>] ? write_msg+0x53/0x110 [netconsole]
[<ffffffffa05418bf>] write_msg+0xcf/0x110 [netconsole]
[<ffffffff8103eba1>] call_console_drivers.constprop.17+0xa1/0x1c0
[<ffffffff8103fb76>] console_unlock+0x2d6/0x450
[<ffffffff8104011e>] vprintk_emit+0x1ee/0x510
[<ffffffff8146f9f6>] printk+0x4d/0x4f
[<ffffffffa0004f1d>] scsi_print_command+0x7d/0xe0 [scsi_mod]

This resulted from my commit ca99ca14c which introduced a mutex_trylock
operation in a path that could execute in interrupt context.  When mutex
debugging is enabled, the above warns the user when we are in fact
exectuting in interrupt context
interrupt context.

After some discussion, It seems that a semaphore is the proper mechanism to use
here.  While mutexes are defined to be unusable in interrupt context, no such
condition exists for semaphores (save for the fact that the non blocking api
calls, like up and down_trylock must be used when in irq context).

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Bart Van Assche <bvanassche@acm.org>
CC: Bart Van Assche <bvanassche@acm.org>
CC: David Miller <davem@davemloft.net>
CC: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-01 15:00:24 -04:00
Patrick McHardy 86a9bad3ab net: vlan: add protocol argument to packet tagging functions
Add a protocol argument to the VLAN packet tagging functions. In case of HW
tagging, we need that protocol available in the ndo_start_xmit functions,
so it is stored in a new field in the skb. The new field fits into a hole
(on 64 bit) and doesn't increase the sks's size.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-19 14:46:06 -04:00
Patrick McHardy f646968f8f net: vlan: rename NETIF_F_HW_VLAN_* feature flags to NETIF_F_HW_VLAN_CTAG_*
Rename the hardware VLAN acceleration features to include "CTAG" to indicate
that they only support CTAGs. Follow up patches will introduce 802.1ad
server provider tagging (STAGs) and require the distinction for hardware not
supporting acclerating both.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-19 14:45:26 -04:00
Lai Jiangshan 7f9421c264 netpoll: use DEFINE_STATIC_SRCU() to define netpoll_srcu
DEFINE_STATIC_SRCU() defines srcu struct and do init at build time.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-17 12:42:43 -04:00
Neil Horman 959d5fdee7 netpoll: fix smatch warnings in netpoll core code
Dan Carpenter contacted me with some notes regarding some smatch warnings in the
netpoll code, some of which I introduced with my recent netpoll locking fixes,
some which were there prior.   Specifically they were:

net-next/net/core/netpoll.c:243 netpoll_poll_dev() warn: inconsistent
  returns mutex:&ni->dev_lock: locked (213,217) unlocked (210,243)
net-next/net/core/netpoll.c:706 netpoll_neigh_reply() warn: potential
  pointer math issue ('skb_transport_header(send_skb)' is a 128 bit pointer)

This patch corrects the locking imbalance (the first error), and adds some
parenthesis to correct the second error.  Tested by myself. Applies to net-next

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Dan Carpenter <dan.carpenter@oracle.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-13 11:56:46 -05:00
Neil Horman 0790bbb68f netpoll: cleanup sparse warnings
With my recent commit I introduced two sparse warnings.  Looking closer there
were a few more in the same file, so I fixed them all up.  Basic rcu pointer
dereferencing suff.

I've validated these changes using CONFIG_PROVE_RCU while starting and stopping
netconsole repeatedly in bonded and non-bonded configurations

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: fengguang.wu@intel.com
CC: David Miller <davem@davemloft.net>
CC: eric.dumazet@gmail.com

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-11 19:19:58 -05:00
Neil Horman 2cde6acd49 netpoll: Fix __netpoll_rcu_free so that it can hold the rtnl lock
__netpoll_rcu_free is used to free netpoll structures when the rtnl_lock is
already held.  The mechanism is used to asynchronously call __netpoll_cleanup
outside of the holding of the rtnl_lock, so as to avoid deadlock.
Unfortunately, __netpoll_cleanup modifies pointers (dev->np), which means the
rtnl_lock must be held while calling it.  Further, it cannot be held, because
rcu callbacks may be issued in softirq contexts, which cannot sleep.

Fix this by converting the rcu callback to a work queue that is guaranteed to
get scheduled in process context, so that we can hold the rtnl properly while
calling __netpoll_cleanup

Tested successfully by myself.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Cong Wang <amwang@redhat.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-11 19:19:33 -05:00
Neil Horman ca99ca14c9 netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb4 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called.  Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes.  Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.

As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution.  We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.

I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device.  While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-06 15:45:03 -05:00
Cong Wang 556e6256c8 netpoll: use the net namespace of current process instead of init_net
This will allow us to setup netconsole in a different namespace
rather than where init_net is.

Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-28 18:32:55 -05:00
Cong Wang faeed828f9 netpoll: use ipv6_addr_equal() to compare ipv6 addr
ipv6_addr_equal() is faster.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-28 18:32:55 -05:00
Cong Wang e39363a9de netpoll: fix an uninitialized variable
Fengguang reported:

   net/core/netpoll.c: In function 'netpoll_setup':
   net/core/netpoll.c:1049:6: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]

in !CONFIG_IPV6 case, we may error out without initializing
'err'.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-22 23:18:59 -05:00
Cong Wang 5bd30d3987 netpoll: fix a missing dev refcounting
__dev_get_by_name() doesn't refcount the network device,
so we have to do this by ourselves. Noticed by Eric.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-16 23:33:06 -05:00
Cong Wang f92d318023 netpoll: fix a rtnl lock assertion failure
v4: hold rtnl lock for the whole netpoll_setup()
v3: remove the comment
v2: use RCU read lock

This patch fixes the following warning:

[   72.013864] RTNL: assertion failed at net/core/dev.c (4955)
[   72.017758] Pid: 668, comm: netpoll-prep-v6 Not tainted 3.8.0-rc1+ #474
[   72.019582] Call Trace:
[   72.020295]  [<ffffffff8176653d>] netdev_master_upper_dev_get+0x35/0x58
[   72.022545]  [<ffffffff81784edd>] netpoll_setup+0x61/0x340
[   72.024846]  [<ffffffff815d837e>] store_enabled+0x82/0xc3
[   72.027466]  [<ffffffff815d7e51>] netconsole_target_attr_store+0x35/0x37
[   72.029348]  [<ffffffff811c3479>] configfs_write_file+0xe2/0x10c
[   72.030959]  [<ffffffff8115d239>] vfs_write+0xaf/0xf6
[   72.032359]  [<ffffffff81978a05>] ? sysret_check+0x22/0x5d
[   72.033824]  [<ffffffff8115d453>] sys_write+0x5c/0x84
[   72.035328]  [<ffffffff819789d9>] system_call_fastpath+0x16/0x1b

In case of other races, hold rtnl lock for the entire netpoll_setup() function.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-16 15:26:03 -05:00
Cong Wang b3d936f3ea netpoll: add IPv6 support
Currently, netpoll only supports IPv4. This patch adds IPv6
support to netpoll so that we can run netconsole over IPv6 network.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-08 17:56:10 -08:00
Cong Wang b7394d2429 netpoll: prepare for ipv6
This patch adjusts some struct and functions, to prepare
for supporting IPv6.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-08 17:56:09 -08:00
Jiri Pirko 49bd8fb0b1 netpoll: remove usage of dev->master
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-04 13:31:50 -08:00
Abhijit Pawar a71258d79e net: remove obsolete simple_strto<foo>
This patch removes the redundant occurences of simple_strto<foo>

Signed-off-by: Abhijit Pawar <abhi.c.pawar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-11 12:49:53 -05:00
Abhijit Pawar 4b5511ebc7 net: remove obsolete simple_strto<foo>
This patch replace the obsolete simple_strto<foo> with kstrto<foo>

Signed-off-by: Abhijit Pawar <abhi.c.pawar@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-10 14:09:00 -05:00
Amerigo Wang 8c4c49df5c netpoll: call ->ndo_select_queue() in tx path
In netpoll tx path, we miss the chance of calling ->ndo_select_queue(),
thus could cause problems when bonding is involved.

This patch makes dev_pick_tx() extern (and rename it to netdev_pick_tx())
to let netpoll call it in netpoll_send_skb_on_dev().

Reported-by: Sylvain Munaut <s.munaut@whatever-company.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Tested-by: Sylvain Munaut <s.munaut@whatever-company.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-19 17:19:09 -04:00
David S. Miller c32f38619a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Merge the 'net' tree to get the recent set of netfilter bug fixes in
order to assist with some merge hassles Pablo is going to have to deal
with for upcoming changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-31 15:14:18 -04:00
Eric Dumazet ee13040901 netpoll: provide an IP ident in UDP frames
Let's fill IP header ident field with a meaningful value,
it might help some setups.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-30 12:32:14 -04:00
Amerigo Wang 072a9c4860 netpoll: revert 6bdb7fe310 and fix be_poll() instead
Against -net.

In the patch "netpoll: re-enable irq in poll_napi()", I tried to
fix the following warning:

[100718.051041] ------------[ cut here ]------------
[100718.051048] WARNING: at kernel/softirq.c:159 local_bh_enable_ip+0x7d/0xb0()
(Not tainted)
[100718.051049] Hardware name: ProLiant BL460c G7
...
[100718.051068] Call Trace:
[100718.051073]  [<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0
[100718.051075]  [<ffffffff8106b79a>] ? warn_slowpath_null+0x1a/0x20
[100718.051077]  [<ffffffff810747ed>] ? local_bh_enable_ip+0x7d/0xb0
[100718.051080]  [<ffffffff8150041b>] ? _spin_unlock_bh+0x1b/0x20
[100718.051085]  [<ffffffffa00ee974>] ? be_process_mcc+0x74/0x230 [be2net]
[100718.051088]  [<ffffffffa00ea68c>] ? be_poll_tx_mcc+0x16c/0x290 [be2net]
[100718.051090]  [<ffffffff8144fe76>] ? netpoll_poll_dev+0xd6/0x490
[100718.051095]  [<ffffffffa01d24a5>] ? bond_poll_controller+0x75/0x80 [bonding]
[100718.051097]  [<ffffffff8144fde5>] ? netpoll_poll_dev+0x45/0x490
[100718.051100]  [<ffffffff81161b19>] ? ksize+0x19/0x80
[100718.051102]  [<ffffffff81450437>] ? netpoll_send_skb_on_dev+0x157/0x240

by reenabling IRQ before calling ->poll, but it seems more
problems are introduced after that patch:

http://ozlabs.org/~akpm/stuff/IMG_20120824_122054.jpg
http://marc.info/?l=linux-netdev&m=134563282530588&w=2

So it is safe to fix be2net driver code directly.

This patch reverts the offending commit and fixes be_poll() by
avoid disabling BH there, this is okay because be_poll()
can be called either by poll_napi() which already disables
IRQ, or by net_rx_action() which already disables BH.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Sylvain Munaut <s.munaut@whatever-company.com>
Cc: Sylvain Munaut <s.munaut@whatever-company.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>
Cc: Sathya Perla <sathya.perla@emulex.com>
Cc: Subbu Seetharaman <subbu.seetharaman@emulex.com>
Cc: Ajit Khaparde <ajit.khaparde@emulex.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Tested-by: Sylvain Munaut <s.munaut@whatever-company.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-29 15:03:23 -04:00
Amerigo Wang 6bdb7fe310 netpoll: re-enable irq in poll_napi()
napi->poll() needs IRQ enabled, so we have to re-enable IRQ before
calling it.

Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 14:33:33 -07:00
Amerigo Wang 689971b446 netpoll: handle vlan tags in netpoll tx and rx path
Without this patch, I can't get netconsole logs remotely over
vlan. The reason is probably we don't handle vlan tags in either
netpoll tx or rx path.

I am not sure if I use these vlan functions correctly, at
least this patch works.

Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 14:33:32 -07:00
Amerigo Wang 2899656b49 netpoll: take rcu_read_lock_bh() in netpoll_send_skb_on_dev()
This patch fixes several problems in the call path of
netpoll_send_skb_on_dev():

1. Disable IRQ's before calling netpoll_send_skb_on_dev().

2. All the callees of netpoll_send_skb_on_dev() should use
   rcu_dereference_bh() to dereference ->npinfo.

3. Rename arp_reply() to netpoll_arp_reply(), the former is too generic.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 14:33:31 -07:00
Amerigo Wang 57c5d46191 netpoll: take rcu_read_lock_bh() in netpoll_rx()
In __netpoll_rx(), it dereferences ->npinfo without rcu_dereference_bh(),
this patch fixes it by using the 'npinfo' passed from netpoll_rx()
where it is already dereferenced with rcu_dereference_bh().

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 14:33:31 -07:00
Amerigo Wang 38e6bc185d netpoll: make __netpoll_cleanup non-block
Like the previous patch, slave_disable_netpoll() and __netpoll_cleanup()
may be called with read_lock() held too, so we should make them
non-block, by moving the cleanup and kfree() to call_rcu_bh() callbacks.

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 14:33:30 -07:00
Amerigo Wang 47be03a28c netpoll: use GFP_ATOMIC in slave_enable_netpoll() and __netpoll_setup()
slave_enable_netpoll() and __netpoll_setup() may be called
with read_lock() held, so should use GFP_ATOMIC to allocate
memory. Eric suggested to pass gfp flags to __netpoll_setup().

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 14:33:30 -07:00
Jiri Pirko 30fdd8a082 netpoll: move np->dev and np->dev_name init into __netpoll_setup()
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17 09:02:36 -07:00