While preparing net flow caches, once a fail may cause potential
memory leak , fix it.
Signed-off-by: NHuajun Li <huajun.li.lee@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add configuration setting for drivers to turn spoof checking on or off
for discrete VFs.

v2 - Fix indentation problem, wrap the ifla_vf_info structure in
     #ifdef __KERNEL__ to prevent user space from accessing and
     change function paramater for the spoof check setting netdev
     op from u8 to bool.
v3 - Preset spoof check setting to -1 so that user space tools such
     as ip can detect that the driver didn't report a spoofcheck
     setting.  Prevents incorrect display of spoof check settings
     for drivers that don't report it.
Signed-off-by: NGreg Rose <gregory.v.rose@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

skb truesize currently accounts for sk_buff struct and part of skb head.
kmalloc() roundings are also ignored.

Considering that skb_shared_info is larger than sk_buff, its time to
take it into account for better memory accounting.

This patch introduces SKB_TRUESIZE(X) macro to centralize various
assumptions into a single place.

At skb alloc phase, we put skb_shared_info struct at the exact end of
skb head, to allow a better use of memory (lowering number of
reallocations), since kmalloc() gives us power-of-two memory blocks.

Unless SLUB/SLUB debug is active, both skb->head and skb_shared_info are
aligned to cache lines, as before.

Note: This patch might trigger performance regressions because of
misconfigured protocol stacks, hitting per socket or global memory
limits that were previously not reached. But its a necessary step for a
more accurate memory accounting.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Andi Kleen <ak@linux.intel.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There's no point in open-coding sock_valbool_flag().
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Amir Vadai wrote:
> When a stream is paused, and its rule is expired while it is paused,
> no new rule will be configured to the HW when traffic resume.
[...]
> - When stream was resumed, traffic was steered again by RSS, and
> because current-cpu was equal to desired-cpu,  ndo_rx_flow_steer
> wasn't called and no rule was configured to the HW.

Fix this by setting the flow's current CPU only in the table for the
newly selected RX queue.
Reported-and-tested-by: NAmir Vadai <amirv@dev.mellanox.co.il>
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The upper protocol numbers of PPPOE are different, and should be treated
specially.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 7361c36c (af_unix: Allow credentials to work across
user and pid namespaces) af_unix performance dropped a lot.

This is because we now take a reference on pid and cred in each write(),
and release them in read(), usually done from another process,
eventually from another cpu. This triggers false sharing.

# Events: 154K cycles
#
# Overhead  Command       Shared Object        Symbol
# ........  .......  ..................  .........................
#
    10.40%  hackbench  [kernel.kallsyms]   [k] put_pid
     8.60%  hackbench  [kernel.kallsyms]   [k] unix_stream_recvmsg
     7.87%  hackbench  [kernel.kallsyms]   [k] unix_stream_sendmsg
     6.11%  hackbench  [kernel.kallsyms]   [k] do_raw_spin_lock
     4.95%  hackbench  [kernel.kallsyms]   [k] unix_scm_to_skb
     4.87%  hackbench  [kernel.kallsyms]   [k] pid_nr_ns
     4.34%  hackbench  [kernel.kallsyms]   [k] cred_to_ucred
     2.39%  hackbench  [kernel.kallsyms]   [k] unix_destruct_scm
     2.24%  hackbench  [kernel.kallsyms]   [k] sub_preempt_count
     1.75%  hackbench  [kernel.kallsyms]   [k] fget_light
     1.51%  hackbench  [kernel.kallsyms]   [k]
__mutex_lock_interruptible_slowpath
     1.42%  hackbench  [kernel.kallsyms]   [k] sock_alloc_send_pskb

This patch includes SCM_CREDENTIALS information in a af_unix message/skb
only if requested by the sender, [man 7 unix for details how to include
ancillary data using sendmsg() system call]

Note: This might break buggy applications that expected SCM_CREDENTIAL
from an unaware write() system call, and receiver not using SO_PASSCRED
socket option.

If SOCK_PASSCRED is set on source or destination socket, we still
include credentials for mere write() syscalls.

Performance boost in hackbench : more than 50% gain on a 16 thread
machine (2 quad-core cpus, 2 threads per core)

hackbench 20 thread 2000

4.228 sec instead of 9.102 sec
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Acked-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

add new fib rule can cause BUG_ON happen
the reproduce shell is
ip rule add pref 38
ip rule add pref 38
ip rule add to 192.168.3.0/24 goto 38
ip rule del pref 38
ip rule add to 192.168.3.0/24 goto 38
ip rule add pref 38

then the BUG_ON will happen
del BUG_ON and use (ctarget == NULL) identify whether this rule is unresolved
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the conversion of struct flowi to a union of AF-specific structs, some
operations on the flow cache need to account for the exact size of the key.
Signed-off-by: NDavid Ward <david.ward@ll.mit.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch does several things:
- introduces __ethtool_get_settings which is called from ethtool code and
  from drivers as well. Put ASSERT_RTNL there.
- dev_ethtool_get_settings() is replaced by __ethtool_get_settings()
- changes calling in drivers so rtnl locking is respected. In
  iboe_get_rate was previously ->get_settings() called unlocked. This
  fixes it. Also prb_calc_retire_blk_tmo() in af_packet.c had the same
  problem. Also fixed by calling __dev_get_by_index() instead of
  dev_get_by_index() and holding rtnl_lock for both calls.
- introduces rtnl_lock in bnx2fc_vport_create() and fcoe_vport_create()
  so bnx2fc_if_create() and fcoe_if_create() are called locked as they
  are from other places.
- use __ethtool_get_settings() in bonding code
Signed-off-by: NJiri Pirko <jpirko@redhat.com>

v2->v3:
	-removed dev_ethtool_get_settings()
	-added ASSERT_RTNL into __ethtool_get_settings()
	-prb_calc_retire_blk_tmo - use __dev_get_by_index() and lock
	 around it and __ethtool_get_settings() call
v1->v2:
        add missing export_symbol
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> [except FCoE bits]
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a time-lag of IFF_RUNNING flag consistency between vlan and
real devices when the real devices are in problem such as link or cable
broken.

This leads to a degradation of Availability such as a delay of failover
in HA systems using vlan since the detection of the problem at real
device is delayed.

We can avoid the linkwatch delay (~1 sec) for devices linked to another
ones, since delay is already done for the realdev.

Based on a previous patch from Mitsuo Hayasaka
Reported-by: NMitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Tom Herbert <therbert@google.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Jesse Gross <jesse@nicira.com>
Tested-by: NMitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dev_forward_skb loops an skb back into host networking
stack which might hang on the memory indefinitely.
In particular, this can happen in macvtap in bridged mode.
Copy the userspace fragments to avoid blocking the
sender in that case.

As this patch makes skb_copy_ubufs extern now,
I also added some documentation and made it clear
the SKBTX_DEV_ZEROCOPY flag automatically instead
of doing it in all callers. This can be made into a separate
patch if people feel it's worth it.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

flow_cache_lookup will return a cached object (or null pointer) that the
resolver (i.e. xfrm_policy_lookup) previously found for another namespace
using the same key/family/dir.  Instead, make the namespace part of what
identifies entries in the cache.

As before, flow_entry_valid will return 0 for entries where the namespace
has been deleted, and they will be removed from the cache the next time
flow_cache_gc_task is run.
Reported-by: NAndrew Dickinson <whydna@whydna.net>
Signed-off-by: NDavid Ward <david.ward@ll.mit.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__netpoll_rx() doesnt properly handle skbs with small header

pskb_may_pull() or pskb_trim_rcsum() can change skb->data, we must
reload it.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Dave Jones reported a lockdep splat triggered by an arp_process() call
from parp_redo().

Commit faa9dcf7 (arp: RCU changes) is the origin of the bug, since
it assumed arp_process() was called under rcu_read_lock(), which is not
true in this particular path.

Instead of adding rcu_read_lock() in parp_redo(), I chose to add it in
neigh_proxy_process() to take care of IPv6 side too.

 ===================================================
 [ INFO: suspicious rcu_dereference_check() usage. ]
 ---------------------------------------------------
 include/linux/inetdevice.h:209 invoked rcu_dereference_check() without
protection!

 other info that might help us debug this:

 rcu_scheduler_active = 1, debug_locks = 0
 4 locks held by setfiles/2123:
  #0:  (&sb->s_type->i_mutex_key#13){+.+.+.}, at: [<ffffffff8114cbc4>]
walk_component+0x1ef/0x3e8
  #1:  (&isec->lock){+.+.+.}, at: [<ffffffff81204bca>]
inode_doinit_with_dentry+0x3f/0x41f
  #2:  (&tbl->proxy_timer){+.-...}, at: [<ffffffff8106a803>]
run_timer_softirq+0x157/0x372
  #3:  (class){+.-...}, at: [<ffffffff8141f256>] neigh_proxy_process
+0x36/0x103

 stack backtrace:
 Pid: 2123, comm: setfiles Tainted: G        W
3.1.0-0.rc2.git7.2.fc16.x86_64 #1
 Call Trace:
  <IRQ>  [<ffffffff8108ca23>] lockdep_rcu_dereference+0xa7/0xaf
  [<ffffffff8146a0b7>] __in_dev_get_rcu+0x55/0x5d
  [<ffffffff8146a751>] arp_process+0x25/0x4d7
  [<ffffffff8146ac11>] parp_redo+0xe/0x10
  [<ffffffff8141f2ba>] neigh_proxy_process+0x9a/0x103
  [<ffffffff8106a8c4>] run_timer_softirq+0x218/0x372
  [<ffffffff8106a803>] ? run_timer_softirq+0x157/0x372
  [<ffffffff8141f220>] ? neigh_stat_seq_open+0x41/0x41
  [<ffffffff8108f2f0>] ? mark_held_locks+0x6d/0x95
  [<ffffffff81062bb6>] __do_softirq+0x112/0x25a
  [<ffffffff8150d27c>] call_softirq+0x1c/0x30
  [<ffffffff81010bf5>] do_softirq+0x4b/0xa2
  [<ffffffff81062f65>] irq_exit+0x5d/0xcf
  [<ffffffff8150dc11>] smp_apic_timer_interrupt+0x7c/0x8a
  [<ffffffff8150baf3>] apic_timer_interrupt+0x73/0x80
  <EOI>  [<ffffffff8108f439>] ? trace_hardirqs_on_caller+0x121/0x158
  [<ffffffff814fc285>] ? __slab_free+0x30/0x24c
  [<ffffffff814fc283>] ? __slab_free+0x2e/0x24c
  [<ffffffff81204e74>] ? inode_doinit_with_dentry+0x2e9/0x41f
  [<ffffffff81204e74>] ? inode_doinit_with_dentry+0x2e9/0x41f
  [<ffffffff81204e74>] ? inode_doinit_with_dentry+0x2e9/0x41f
  [<ffffffff81130cb0>] kfree+0x108/0x131
  [<ffffffff81204e74>] inode_doinit_with_dentry+0x2e9/0x41f
  [<ffffffff81204fc6>] selinux_d_instantiate+0x1c/0x1e
  [<ffffffff81200f4f>] security_d_instantiate+0x21/0x23
  [<ffffffff81154625>] d_instantiate+0x5c/0x61
  [<ffffffff811563ca>] d_splice_alias+0xbc/0xd2
  [<ffffffff811b17ff>] ext4_lookup+0xba/0xeb
  [<ffffffff8114bf1e>] d_alloc_and_lookup+0x45/0x6b
  [<ffffffff8114cbea>] walk_component+0x215/0x3e8
  [<ffffffff8114cdf8>] lookup_last+0x3b/0x3d
  [<ffffffff8114daf3>] path_lookupat+0x82/0x2af
  [<ffffffff8110fc53>] ? might_fault+0xa5/0xac
  [<ffffffff8110fc0a>] ? might_fault+0x5c/0xac
  [<ffffffff8114c564>] ? getname_flags+0x31/0x1ca
  [<ffffffff8114dd48>] do_path_lookup+0x28/0x97
  [<ffffffff8114df2c>] user_path_at+0x59/0x96
  [<ffffffff811467ad>] ? cp_new_stat+0xf7/0x10d
  [<ffffffff811469a6>] vfs_fstatat+0x44/0x6e
  [<ffffffff811469ee>] vfs_lstat+0x1e/0x20
  [<ffffffff81146b3d>] sys_newlstat+0x1a/0x33
  [<ffffffff8108f439>] ? trace_hardirqs_on_caller+0x121/0x158
  [<ffffffff812535fe>] ? trace_hardirqs_on_thunk+0x3a/0x3f
  [<ffffffff8150af82>] system_call_fastpath+0x16/0x1b
Reported-by: NDave Jones <davej@redhat.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: netdev@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Skip IPIP header to get proper layer-4 information.

Like GRE tunnels, this only works if rxhash is not already provided by
the device itself (ethtool -K ethX rxhash off), to allow kernel compute
a software rxhash.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now, when vlan tag on untagged in non-accelerated path is stripped from
skb, headers are reset right away. Benefit from that and avoid calling
__netif_receive_skb recursivelly and just use another_round.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Inspect the payload of PPPOE session messages for the 4 tuples to generate
skb->rxhash.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For the 802.1Q packets, if the NIC doesn't support hw-accel-vlan-rx, RPS
won't inspect the internal 4 tuples to generate skb->rxhash, so this kind
of traffic can't get any benefit from RPS.

This patch adds the support for 802.1Q to RPS.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove no longer used operation.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use IFF_UNICAST_FTL to find out if driver handles unicast address
filtering. In case it does not, promisc mode is entered.

Patch also fixes following drivers:
stmmac, niu: support uc filtering and yet it propagated
	ndo_set_multicast_list
bna, benet, pxa168_eth, ks8851, ks8851_mll, ksz884x : has set
	ndo_set_rx_mode but do not support uc filtering
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Crack open GRE packets in __skb_get_rxhash to compute 4-tuple hash on
in encapsulated packet.  Note that this is used only when the
__skb_get_rxhash is taken, in particular only when the device does
not compute provide the rxhash (ie. feature is disabled).

This was tested by creating a single GRE tunnel between two 16 core
AMD machines.  200 netperf TCP_RR streams were ran with 1 byte
request and response size.

Without patch: 157497 tps, 50/90/99% latencies 1250/1292/1364 usecs
With patch: 325896 tps, 50/90/99% latencies 603/848/1169
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Basics for looking for ports in encapsulated packets in tunnels.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The l4_rxhash flag was added to the skb structure to indicate
that the rxhash value was computed over the 4 tuple for the
packet which includes the port information in the encapsulated
transport packet.  This is used by the stack to preserve the
rxhash value in __skb_rx_tunnel.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use some variables for clarity and extensibility.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RCU api had been completed and rcu_access_pointer() or
rcu_dereference_protected() are better than generic
rcu_dereference_raw()
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the artificial HZ latency on arp resolution.

Instead of firing a timer in one jiffy (up to 10 ms if HZ=100), lets
send the ARP message immediately.

Before patch :

# arp -d 192.168.20.108 ; ping -c 3 192.168.20.108
PING 192.168.20.108 (192.168.20.108) 56(84) bytes of data.
64 bytes from 192.168.20.108: icmp_seq=1 ttl=64 time=9.91 ms
64 bytes from 192.168.20.108: icmp_seq=2 ttl=64 time=0.065 ms
64 bytes from 192.168.20.108: icmp_seq=3 ttl=64 time=0.061 ms

After patch :

$ arp -d 192.168.20.108 ; ping -c 3 192.168.20.108
PING 192.168.20.108 (192.168.20.108) 56(84) bytes of data.
64 bytes from 192.168.20.108: icmp_seq=1 ttl=64 time=0.152 ms
64 bytes from 192.168.20.108: icmp_seq=2 ttl=64 time=0.064 ms
64 bytes from 192.168.20.108: icmp_seq=3 ttl=64 time=0.074 ms
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dev->real_num_tx_queues is correctly set already in alloc_netdev_mqs.
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch corrects an erroneous update of credential's gid with uid
introduced in commit 257b5358 since 2.6.36.
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Followup of commit f2c31e32 (fix NULL dereferences in
check_peer_redir()).

We need to make sure dst neighbour doesnt change in dst_ifdown().

Fix some sparse errors.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.
Reported-by: NDan Kaminsky <dan@doxpara.com>
Tested-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since skb_copy_bits() is called from assembly, add a fat comment to make
clear we should think twice before changing its prototype.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pktgen attempts to transmit shared skbs to net devices, which can't be used by
some drivers as they keep state information in skbs.  This patch adds a flag
marking drivers as being able to handle shared skbs in their tx path.  Drivers
are defaulted to being unable to do so, but calling ether_setup enables this
flag, as 90% of the drivers calling ether_setup touch real hardware and can
handle shared skbs.  A subsequent patch will audit drivers to ensure that the
flag is set properly
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
Reported-by: NJiri Pirko <jpirko@redhat.com>
CC: Robert Olsson <robert.olsson@its.uu.se>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Alexey Dobriyan <adobriyan@gmail.com>
CC: David S. Miller <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No need to use int, its uses are boolean.
May save a few bytes one day.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As reported by Ben Greer and Froncois Romieu. The code path in
the netif_carrier code leads it to try and disable
a late workqueue to reenable it immediately
netif_carrier_on
-> linkwatch_fire_event
   -> linkwatch_schedule_work
      -> cancel_delayed_work
         -> del_timer_sync

If __cancel_delayed_work is used instead then there is no
problem of waiting for running linkwatch_event.

There is a race between linkwatch_event running re-scheduling
but it is harmless to schedule an extra scan of the linkwatch queue.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some drivers (ab)use the ethtool_ops::get_regs operation to expose
only a hardware revision ID.  Commit
a77f5db3 ('ethtool: Allocate register
dump buffer with vmalloc()') had the side-effect of breaking these, as
vmalloc() returns a null pointer for size=0 whereas kmalloc() did not.

For backward-compatibility, allow zero-length dumps again.
Reported-by: NKalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org [2.6.37+]
Signed-off-by: NDavid S. Miller <davem@davemloft.net>