During initialization of vmxnet3, the state of LRO
gets out of sync with netdev->features.
This leads to very poor TCP performance in a IP forwarding
setup and is hitting many VMware users.
Simplified call sequence:
1. vmxnet3_declare_features() initializes "adapter->lro" to true.
2. The kernel automatically disables LRO if IP forwarding is enabled,
so vmxnet3_set_flags() gets called. This also updates netdev->features.
3. Now vmxnet3_setup_driver_shared() is called. "adapter->lro" is still
set to true and LRO gets enabled again, even though
netdev->features shows it's disabled.
Fix it by updating "adapter->lro", too.
The private vmxnet3 adapter flags are scheduled for removal
in net-next, see commit a0d2730c95
"net: vmxnet3: convert to hw_features".
Patch applies to 2.6.37 / 2.6.38 and 2.6.39-rc6.
Please CC: comments.
Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 747df2258b ('sfc: Always map MCDI
shared memory as uncacheable') introduced a separate mapping for the
MCDI shared memory (MC_TREG_SMEM). This means we can no longer easily
include it in the register dump. Since it is not particularly useful
in debugging, substitute a recognisable dummy value.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
bridge: fix forwarding of IPv6
bonding,llc: Fix structure sizeof incompatibility for some PDUs
ipv6: restore correct ECN handling on TCP xmit
ne-h8300: Fix regression caused during net_device_ops conversion
hydra: Fix regression caused during net_device_ops conversion
zorro8390: Fix regression caused during net_device_ops conversion
sfc: Always map MCDI shared memory as uncacheable
ehea: Fix memory hotplug oops
libertas: fix cmdpendingq locking
iwlegacy: fix IBSS mode crashes
ath9k: Fix a warning due to a queued work during S3 state
mac80211: don't start the dynamic ps timer if not associated
With some combinations of arch/compiler (e.g. arm-linux-gcc) the sizeof
operator on structure returns value greater than expected. In cases when the
structure is used for mapping PDU fields it may lead to unexpected results
(such as holes and alignment problems in skb data). __packed prevents this
undesired behavior.
Signed-off-by: Vitalii Demianets <vitas@nppfactor.kiev.ua>
Signed-off-by: David S. Miller <davem@davemloft.net>
Changeset dcd39c9029 ("ne-h8300: convert to
net_device_ops") broke ne-h8300 by adding 8390.o to the link. That
meant that lib8390.c was included twice, once in ne-h8300.c and once in
8390.c, subject to different macros. This patch reverts that by
avoiding the wrappers in 8390.c.
Fix based on commits 217cbfa856 ("mac8390:
fix regression caused during net_device_ops conversion") and
4e0168fa48 ("mac8390: fix build with
NET_POLL_CONTROLLER").
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Changeset 5618f0d119 ("hydra: convert to
net_device_ops") broke hydra by adding 8390.o to the link. That
meant that lib8390.c was included twice, once in hydra.c and once in
8390.c, subject to different macros. This patch reverts that by
avoiding the wrappers in 8390.c.
Fix based on commits 217cbfa856 ("mac8390:
fix regression caused during net_device_ops conversion") and
4e0168fa48 ("mac8390: fix build with
NET_POLL_CONTROLLER").
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Changeset b6114794a1 ("zorro8390: convert to
net_device_ops") broke zorro8390 by adding 8390.o to the link. That
meant that lib8390.c was included twice, once in zorro8390.c and once in
8390.c, subject to different macros. This patch reverts that by
avoiding the wrappers in 8390.c.
Fix based on commits 217cbfa856 ("mac8390:
fix regression caused during net_device_ops conversion") and
4e0168fa48 ("mac8390: fix build with
NET_POLL_CONTROLLER").
Reported-by: Christian T. Steigies <cts@debian.org>
Suggested-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Christian T. Steigies <cts@debian.org>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
ARM: 6870/1: The mandatory barrier rmb() must be a dsb() in for device accesses
ARM: 6892/1: handle ptrace requests to change PC during interrupted system calls
ARM: 6890/1: memmap: only free allocated memmap entries when using SPARSEMEM
ARM: zImage: the page table memory must be considered before relocation
ARM: zImage: make sure not to relocate on top of the relocation code
ARM: zImage: Fix bad SP address after relocating kernel
ARM: zImage: make sure the stack is 64-bit aligned
ARM: RiscPC: acornfb: fix section mismatches
ARM: RiscPC: etherh: fix section mismatches
We enabled write-combining for memory-mapped registers in commit
65f0b417de, but inhibited it for the
MCDI shared memory where this is not supported. However,
write-combining mappings also allow read-reordering, which may also
be a problem.
I found that when an SFC9000-family controller is connected to an
Intel 3000 chipset, and write-combining is enabled, the controller
stops responding to PCIe read requests during driver initialisation
while the driver is polling for completion of an MCDI command. This
results in an NMI and system hang. Adding read memory barriers
between all reads to the shared memory area appears to reduce but not
eliminate the probability of this.
We have not yet established whether this is a bug in our BIU or in the
PCIe bridge. For now, work around by mapping the shared memory area
separately.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
TTY layer expects 0 if the ldisc->open operation succeeded.
Reported-by: Matvejchikov Ilya <matvejchikov@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Like other mobile broadband device ethernet interfaces, mark the LG
VL600 with the 'wwan' devtype so userspace knows it needs additional
configuration via the AT port before the interface can be used.
Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We occasionally see list corruption using libertas.
While we haven't been able to diagnose this precisely, we have spotted
a possible cause: cmdpendingq is generally modified with driver_lock
held. However, there are a couple of points where this is not the case.
Fix up those operations to execute under the lock, it seems like
the correct thing to do and will hopefully improve the situation.
Signed-off-by: Paul Fox <pgf@laptop.org>
Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Dan Williams <dcbw@redhat.com>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We should not switch to non-IBSS channels when working in IBSS mode,
otherwise there are microcode errors, and after some time system
crashes.
This bug is only observable when software scan is used in IBSS mode,
so should be considered as regression after:
commit 0263aa4529
Author: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Tue Mar 29 11:24:21 2011 +0200
iwl3945: disable hw scan by default
However IBSS mode check, which this patch add again, was removed by
commit b2f30e8bdd
Author: Johannes Berg <johannes.berg@intel.com>
Date: Thu Jan 21 07:32:20 2010 -0800
iwlwifi: remove IBSS channel sanity check
That commit claim that mac80211 will not use non-IBSS channel in IBSS
mode, what definitely is not true. Bug probably should be fixed in
mac80211, but that will require more work, so better to apply that patch
temporally, and provide proper mac80211 fix latter.
Resolves:
https://bugzilla.kernel.org/show_bug.cgi?id=34452
Reported-and-tested-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: stable@kernel.org # 2.6.38.5+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
during suspend/S3 state drv_flush is called from mac80211 irrespective of
interface count. In ath9k we queue a work in ath9k_flush which we expect
to be cancelled in the drv_stop call back. during suspend process mac80211
calls drv_stop only when the interface count(local->count) is non-zero.
unfortunately when the network manager is enabled, drv_flush is called
while drv_stop is not called as local->count reaches '0'.
So fix this by simply checking for the device presence in the
drv_flush call back in the driver before queueing work or anything else.
this patch fixes the following WARNING
Call Trace:
[<c014c6e2>] warn_slowpath_common+0x72/0xa0
[<fc133f99>] ? ieee80211_can_queue_work+0x39/0x50 [mac80211]
[<fc133f99>] ? ieee80211_can_queue_work+0x39/0x50 [mac80211]
[<c014c75b>] warn_slowpath_fmt+0x2b/0x30
[<fc133f99>] ieee80211_can_queue_work+0x39/0x50 [mac80211]
[<fc134ed1>] ieee80211_queue_delayed_work+0x21/0x50 [mac80211]
[<fc1e5b22>] ath_tx_complete_poll_work+0xb2/0x100 [ath9k]
[<c016399e>] run_workqueue+0x8e/0x150
[<fc1e5a70>] ? ath_tx_complete_poll_work+0x0/0x100 [ath9k]
[<c0163ae4>] worker_thread+0x84/0xe0
[<c0167a60>] ? autoremove_wake_function+0x0/0x50
[<c0163a60>] ? worker_thread+0x0/0xe0
[<c01677d4>] kthread+0x74/0x80
[<c0167760>] ? kthread+0x0/0x80
[<c0104087>] kernel_thread_helper+0x7/0x10
---[ end trace 2aff81010df9215b ]---
Signed-off-by: Rajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Support new device OKI SEMICONDUCTOR ML7223 IOH(Input/Output Hub).
The ML7223 IOH is for MP(Media Phone) use.
The ML7223 is companion chip for Intel Atom E6xx series.
The ML7223 is completely compatible for Intel EG20T PCH.
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The checksum judgment was mistaken.
Judgment result
0:Correct 1:Wrong
This patch fixes the issue.
Signed-off-by: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The collision detection setting was invalid.
When collision occurred, because data was not resent,
there was an issue to which a transmitting throughput falls.
This patch enables the collision detection.
Signed-off-by: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TTY layer expects 0 if the ldisc->open operation succeeded.
Signed-off-by : Matvejchikov Ilya <matvejchikov@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixed bug to make sure 'pvid' retrieval will work on big endian hosts.
Fixed incorrect comparison between the Rx Completion's 16-bit VLAN TCI
and the PVID. Now comparing only the relevant 12 bits corresponding to
the VID.
Renamed 'vid' field under Rx Completion to 'vlan_tag' to reflect
accurate description.
Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently EHEA reports to ethtool as supporting 10M, 100M, 1G and
10G and connected to FIBRE independent of the hardware configuration.
However, when connected to FIBRE the only supported speed is 10G
full-duplex, and the other speeds and modes are only supported
when connected to twisted pair.
Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
Acked-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The USB protocol this driver implements appears to require 2 bytes of
padding in front of each received packet. This used to be equal to
the value of NET_IP_ALIGN on x86, so the driver abused that constant
and mostly worked, but this is no longer the case. The driver also
mixed up the URB and packet lengths, resulting in 2 bytes of junk at
the end of the skb.
Introduce a private constant for the 2 bytes of padding; fix this
confusion and check for the under-length case.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
WARNING: drivers/net/arm/built-in.o(.data+0x0): Section mismatch in reference from the variable etherh_driver to the function .init.text:etherh_probe()
The variable etherh_driver references
the function __init etherh_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
RTR frames do have a valid data length code on CAN.
The driver for SJA1000 did not handle that situation properly.
Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
84c49d8c3e ("veth: remove unneeded
ifname code from veth_newlink()") caused regression on veth
creation. This patch reverts the original one.
Reported-by: Michał Mirosław <mirqus@gmail.com>
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The reset loop check should check the MII_BMCR register value for
BMCR_RESET rather than for MII_BMCR (the register address, which also
happens to be zero).
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: David S. Miller <davem@davemloft.net>
tg3 is supposed to enable WoL by default on adapters which support
that, but it fails to do so unless the adapter's
/sys/devices/.../power/wakeup file contains 'enabled' during the
initialization of the adapter. Fix that by making tg3 use
device_set_wakeup_enable() to enable wakeup automatically whenever
WoL should be enabled by default.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support of pause frames advertise in mii_get_an. This provides all drivers
that use mii_ethtool_gset to represent their own and Link partner flow control
abilities in ethtool.
Signed-off-by: Artem Polyakov <artpol84@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adam Jaremko <adam.jaremko@gmail.com>
Acked-by: Po-Yu Chuang <ratbert@faraday-tech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some newer Huawei devices (T-Mobile Rocket, others) have cdc-ether
compatible ports, so recognize and expose them.
Signed-off-by: Dan Williams <dcbw@redhat.com>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This oops was recently reported to me:
invalid opcode: 0000 [#1] SMP
last sysfs file:
/sys/devices/pci0000:00/0000:00:01.0/0000:01:0d.0/0000:02:05.0/device
CPU 1
Modules linked in: bnx2(+) sunrpc ipv6 dm_mirror dm_region_hash dm_log sg
microcode serio_raw amd64_edac_mod edac_core edac_mce_amd k8temp i2c_piix4
shpchp ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase
scsi_transport_sas radeon ttm drm_kms_helper drm hwmon i2c_algo_bit i2c_core
dm_mod [last unloaded: bnx2]
Modules linked in: bnx2(+) sunrpc ipv6 dm_mirror dm_region_hash dm_log sg
microcode serio_raw amd64_edac_mod edac_core edac_mce_amd k8temp i2c_piix4
shpchp ext4 mbcache jbd2 sd_mod crc_t10dif mptsas mptscsih mptbase
scsi_transport_sas radeon ttm drm_kms_helper drm hwmon i2c_algo_bit i2c_core
dm_mod [last unloaded: bnx2]
Pid: 23900, comm: pidof Not tainted 2.6.32-130.el6.x86_64 #1 BladeCenter LS21
-[797251Z]-
RIP: 0010:[<ffffffffa058b270>] [<ffffffffa058b270>] 0xffffffffa058b270
RSP: 0018:ffff880002083e48 EFLAGS: 00010246
RAX: ffff880002083e90 RBX: ffff88007ccd4000 RCX: 0000000000000000
RDX: 0000000000000100 RSI: dead000000200200 RDI: ffff8800007b8700
RBP: ffff880002083ed0 R08: ffff88000208db40 R09: 0000022d191d27c8
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800007b9bc8
R13: ffff880002083e90 R14: ffff8800007b8700 R15: ffffffffa058b270
FS: 00007fbb3bcf7700(0000) GS:ffff880002080000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001664a98 CR3: 0000000060395000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process pidof (pid: 23900, threadinfo ffff8800007e8000, task ffff8800091c0040)
Stack:
ffffffff81079f77 ffffffff8109e010 ffff88007ccd5c20 ffff88007ccd5820
<0> ffff88007ccd5420 ffff8800007e9fd8 ffff8800007e9fd8 0000010000000000
<0> ffff88007ccd5020 ffff880002083e90 ffff880002083e90 ffffffff8102a00d
Call Trace:
<IRQ>
[<ffffffff81079f77>] ? run_timer_softirq+0x197/0x340
[<ffffffff8109e010>] ? tick_sched_timer+0x0/0xc0
[<ffffffff8102a00d>] ? lapic_next_event+0x1d/0x30
[<ffffffff8106f737>] __do_softirq+0xb7/0x1e0
[<ffffffff81092cc0>] ? hrtimer_interrupt+0x140/0x250
[<ffffffff81185f90>] ? filldir+0x0/0xe0
[<ffffffff8100c2cc>] call_softirq+0x1c/0x30
[<ffffffff8100df05>] do_softirq+0x65/0xa0
[<ffffffff8106f525>] irq_exit+0x85/0x90
[<ffffffff814e3340>] smp_apic_timer_interrupt+0x70/0x9b
[<ffffffff8100bc93>] apic_timer_interrupt+0x13/0x20
<EOI>
[<ffffffff81211ba5>] ? selinux_file_permission+0x45/0x150
[<ffffffff81262a75>] ? _atomic_dec_and_lock+0x55/0x80
[<ffffffff812050c6>] security_file_permission+0x16/0x20
[<ffffffff811861c1>] vfs_readdir+0x71/0xe0
[<ffffffff81186399>] sys_getdents+0x89/0xf0
[<ffffffff8100b172>] system_call_fastpath+0x16/0x1b
It occured during some stress testing, in which the reporter was repeatedly
removing and modprobing the bnx2 module while doing various other random
operations on the bnx2 registered net device. Noting that this error occured on
a serdes based device, we noted that there were a few ethtool operations (most
notably self_test and set_phys_id) that have execution paths that lead into
bnx2_setup_serdes_phy. This function is notable because it executes a mod_timer
call, which starts the bp->timer running. Currently bnx2 is setup to assume
that this timer only nees to be stopped when bnx2_close or bnx2_suspend is
called. Since the above ethtool operations are not gated on the net device
having been opened however, that assumption is incorrect, and can lead to the
timer still running after the module has been removed, leading to the oops above
(as well as other simmilar oopses).
Fix the problem by ensuring that the timer is stopped when pci_device_unregister
is called.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Hushan Jia <hjia@redhat.com>
CC: Michael Chan <mchan@broadcom.com>
CC: "David S. Miller" <davem@davemloft.net>
Acked-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Need to use broadcast sta_id for management frames, otherwise we broke
BA session in the firmware and get messages like that:
"Received BA when not expected"
or (on older kernels):
"BA scd_flow 0 does not match txq_id 10"
This fix regression introduced in 2.6.35 during station management
code rewrite by:
commit 2a87c26bbe
Author: Johannes Berg <johannes.berg@intel.com>
Date: Fri Apr 30 11:30:45 2010 -0700
iwlwifi: use iwl_find_station less
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Need to use broadcast sta_id for management frames, otherwise we broke
BA session in the firmware and get messages like that:
"Received BA when not expected"
or (on older kernels):
"BA scd_flow 0 does not match txq_id 10"
This fix regression introduced in 2.6.35 during station management
code rewrite by:
commit 2a87c26bbe
Author: Johannes Berg <johannes.berg@intel.com>
Date: Fri Apr 30 11:30:45 2010 -0700
iwlwifi: use iwl_find_station less
Patch partially resolve:
https://bugzilla.kernel.org/show_bug.cgi?id=16691
However, there are still 11n performance problems on 4965 and 5xxx
devices that need to be investigated.
Cc: stable@kernel.org # 2.6.35+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Resubmit interrupt URB if device is open. Use a flag set in
usbnet_open() to determine this state. Also kill and free
interrupt URB in usbnet_disconnect().
[Rebased off git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git]
Signed-off-by: Paul Stewart <pstew@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 5ed540aecc change the led behavior
for iwlwifi driver; the side effect cause led blink all the time.
Modify the led blink table to fix this problem
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The default maximum transmit length for NCM USB frames should be so
that a short packet happens at the end if the device supports a length
greater than the defined maximum. This is achieved by adding 4 bytes
to the maximum length so that the existing logic can fit a short
packet there.
Signed-off-by: Hans Petter Selasky <hselasky@c2i.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The firmware is cached during the first successfull call to open() and
released once the network device is unregistered. The driver uses the
cached firmware between open() and unregister_netdev().
So far the firmware is optional : a failure to load the firmware does
not prevent open() to success. It is thus necessary to 1) unregister
all 816x / 810[23] devices and 2) force a driver probe to issue a new
firmware load.
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Fixed-by: Ciprian Docan <docan@eden.rutgers.edu>
Cc: Realtek linux nic maintainers <nic_swsd@realtek.com>
Fixed packets parameters for FW in UDP checksum offload flow.
Do not dereference TCP headers on non TCP frames.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A deadlock was reported to me recently that occured when netconsole was being
used in a virtual guest. If the virtio_net driver was removed while netconsole
was setup to use an interface that was driven by that driver, the guest
deadlocked. No backtrace was provided because netconsole was the only console
configured, but it became clear pretty quickly what the problem was. In
netconsole_netdev_event, if we get an unregister event, we call
__netpoll_cleanup with the target_list_lock held and irqs disabled.
__netpoll_cleanup can, if pending netpoll packets are waiting call
cancel_delayed_work_sync, which is a sleeping path. the might_sleep call in
that path gets triggered, causing a console warning to be issued. The
netconsole write handler of course tries to take the target_list_lock again,
which we already hold, causing deadlock.
The fix is pretty striaghtforward. Simply drop the target_list_lock and
re-enable irqs prior to calling __netpoll_cleanup, the re-acquire the lock, and
restart the loop. Confirmed by myself to fix the problem reported.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds