We need to tweak how we query the active capture/playback state after
the recent overhauls of common code.
Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Liam Girdwood <lrg@slimlogic.co.uk> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
If a timer interrupt was delayed too much, hrtimer_forward_now() will
forward the timer expiry more than once. When this happens, the
additional number of elapsed ALSA timer ticks must be passed to
snd_timer_interrupt() to prevent the ALSA timer from falling behind.
This mostly fixes MIDI slowdown problems on highly-loaded systems with
badly behaved interrupt handlers.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Reported-and-tested-by: Arthur Marsh <arthur.marsh@internode.on.net> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The Conexant codec driver adds the jack arrays in init callback which
may be called also in each PM resume. This results in the addition of
new jack element at each time.
The fix is to check whether the requested jack is already present in
the array.
Fix playback/capture channels patch to change supported playback
channels of au8830 to 1,2,4 and capture channels to 1,2.
This prevent oops when oss emulation use SNDCTL_DSP_CHANNELS to
set 3 Channels
Signed-off-by: Raymond Yau <superquad.vortex2@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
| drivers/media/radio/radio-aimslab.c: In function ‘rt_decvol’:
| drivers/media/radio/radio-aimslab.c:76: error: implicit declaration of function ‘msleep’
gcc 4.5+ doesn't properly evaluate some inlined expressions.
A previous patch were proposed by Andrew Morton using noinline.
However, the entire inlined function is bogus, so let's just
remove it and be happy.
Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
There was a configuration page timing out during the initial port
enable at driver load time. The port enable would fail, and this would
result in the driver unloading itself, meanwhile the driver was accessing
freed memory in another context resulting in the panic. The fix is to
prevent access to freed memory once the driver had issued the diag reset
which woke up the sleeping port enable process. The routine
_base_reset_handler was reorganized so the last sleeping process woken up was
the port_enable.
Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The ioc->hba_queue_depth is not properly resized when the controller
firmware reports that it supports more outstanding IO than what can be fit
inside the reply descriptor pool depth. This is reproduced by setting the
controller global credits larger than 30,000. The bug results in an
incorrect sizing of the queues. The fix is to resize the queue_size by
dividing queue_diff by two.
Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
When zoning end devices, the driver is not sending device
removal handshake alogrithm to firmware. This results in controller
firmware not sending sas topology add events the next time the device is
added. The fix is the driver should be doing the device removal handshake
even though the PHYSTATUS_VACANT bit is set in the PhyStatus of the
event data. The current design is avoiding the handshake when the
VACANT bit is set in the phy status.
Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
libsas makes use of scsi_schedule_eh() but forgets to clear the
host_eh_scheduled flag in its error handling routine. Because of this,
the error handler thread never gets to sleep; it's constantly awake and
trying to run the error routine leading to console spew and inability to
run anything else (at least on a UP system). The fix is to clear the
flag as we splice the work queue.
Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Our current handling of medium error assumes that data is returned up
to the bad sector. This assumption holds good for all disk devices,
all DIF arrays and most ordinary arrays. However, an LSI array engine
was recently discovered which reports a medium error without returning
any data. This means that when we report good data up to the medium
error, we've reported junk originally in the buffer as good. Worse,
if the read consists of requested data plus a readahead, and the error
occurs in readahead, we'll just strip off the readahead and report
junk up to userspace as good data with no error.
The fix for this is to have the error position computation take into
account the amount of data returned by the driver using the scsi
residual data. Unfortunately, not every driver fills in this data,
but for those who don't, it's set to zero, which means we'll think a
full set of data was transferred and the behaviour will be identical
to the prior behaviour of the code (believe the buffer up to the error
sector). All modern drivers seem to set the residual, so that should
fix up the LSI failure/corruption case.
Reported-by: Douglas Gilbert <dgilbert@interlog.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
There is a roundng error in delimiter padding computation
which causes severe throughput drop with some of AR9003.
signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Since commit 6cd0b1cb872b3bf9fc5de4536404206ab74bafdd "iwlagn: fix
hw-rfkill while the interface is down", we enable interrupts when
device is not ready to receive them. However hardware, when it is in
some inconsistent state, can generate other than rfkill interrupts
and crash the system. I can reproduce crash with "kernel BUG at
drivers/net/wireless/iwlwifi/iwl-agn.c:1010!" message, when forcing
firmware restarts.
To fix only enable rfkill interrupt when down device and after probe.
I checked patch on laptop with 5100 device, rfkill change is still
passed to user space when device is down.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The hv_netvsc gets RNDIS_STATUS_MEDIA_CONNECT event after the VM
is live migrated. Adding call to netif_notify_peers() for this event
to send GARP (Gratuitous ARP) to notify network peers. Otherwise,
the VM's network connection may stop after a live migration.
This patch should also be applied to stable kernel 2.6.32 and later.
The ni_labpc driver module only requests a shared IRQ for PCI devices,
requesting a non-shared IRQ for non-PCI devices.
As this module is also used by the ni_labpc_cs module for certain
National Instruments PCMCIA cards, it also needs to request a shared IRQ
for PCMCIA devices, otherwise you get a IRQ mismatch with the CardBus
controller.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Like with other host controllers capable of operating at both high
speed and full speed, we need to indicate that the emulated controller
presented by dummy-hcd has this ability. Otherwise usbcore will not
accept full-speed gadgets under dummy-hcd. This patch (as1469) sets
the appropriate has_tt flag.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This patch (as1460) fixes a regression in the usbip driver caused by
the new check for Transaction Translators in USB-2 hubs. The root hub
registered by vhci_hcd needs to have the has_tt flag set, because it
can connect to low- and full-speed devices as well as high-speed
devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
MUSB is a non-standard host implementation which
can handle all speeds with the same core. We need
to set has_tt flag after commit d199c96d41d80a567493e12b8e96ea056a1350c1 (USB: prevent
buggy hubs from crashing the USB stack) in order for
MUSB HCD to continue working.
Signed-off-by: Felipe Balbi <balbi@ti.com> Cc: Alan Stern <stern@rowland.harvard.edu> Tested-by: Michael Jones <michael.jones@matrix-vision.de> Tested-by: Alexander Holler <holler@ahsoftware.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
If anyone comes across a high-speed hub that (by mistake or by design)
claims to have no Transaction Translators, plugging a full- or
low-speed device into it will cause the USB stack to crash. This
patch (as1446) prevents the problem by ignoring such devices, since
the kernel has no way to communicate with them.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Perry Neben <neben@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Add the USB Vendor ID and Product ID for a Acton Research Corp.
spectrograph device with a FTDI chip for serial I/O.
Signed-off-by: Michael H Williamson <michael.h.williamson@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The major and minor number saved in the product_info structure
were copied from the address instead of the data, causing an
inconsistency in the reported versions during firmware loading:
usb 4-1: firmware: requesting edgeport/down.fw
/usr/src/linux/drivers/usb/serial/io_edgeport.c: downloading firmware version (930) 1.16.4
[..]
/usr/src/linux/drivers/usb/serial/io_edgeport.c: edge_startup - time 3 4328191260
/usr/src/linux/drivers/usb/serial/io_edgeport.c: FirmwareMajorVersion 0.0.4
This can cause some confusion whether firmware loaded successfully
or not.
This patch (as1442) fixes a bug in g_printer: Module parameters should
not be marked "__initdata" if they are accessible in sysfs (i.e., if
the mode value in the module_param() macro is nonzero). Otherwise
attempts to access the parameters will cause addressing violations.
Character-string module parameters must not be marked "__initdata"
if the module can be unloaded, because the kernel needs to access the
parameter variable at unload time in order to free the
dynamically-allocated string.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Roland Kletzing <devzero@web.de> CC: Craig W. Nadler <craig@nadler.us> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This patch (as1440) fixes a bug in ehci-hcd. ehci->periodic_size is
used to compute the size in a dma_alloc_coherent() call, but then it
gets changed later on. As a result, the corresponding call to
dma_free_coherent() passes a different size from the original
allocation. Fix the problem by adjusting ehci->periodic_size before
carrying out any of the memory allocations.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> CC: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
AMD Hudson also needs the same ASPM quirk as SB800
Signed-off-by: Alex He <alex.he@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
/drivers/usb/serial/option.c: Adding support for Cinterion's HC25, HC28,
HC28J, EU3-E, EU3-P and PH8 by correcting/adding Cinterion's and
Siemens' Vendor IDs as well as Product IDs and USB_DEVICE tuples
Signed-off-by: Nicolaus Colberg <nicolaus.colberg@cinterion.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
I found the original patch on the db0fhn repeater wiki (couldn't find the email
of the origial author) I guess it was never commited.
I updated and added some Icom HAM-radio devices to the ftdi driver.
Added extra comments to make clear what devices it are.
This patch (as1438) adds an unusual_devs entry for the MagicPixel
FW_Omega2 chip, used in the CamSport Evo camera. The firmware
incorrectly reports a vendor-specific bDeviceClass.
[PG: change USB_ --> US_ to match 2.6.34.x naming conventions]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: <ttkspam@free.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The TrekStor DataStation maxi g.u external hard drive enclosure uses a
JMicron USB to SATA chip which needs the US_FL_IGNORE_RESIDUE flag to work
properly.
[PG: change USB_ --> US_ to match 2.6.34.x naming conventions]
Signed-off-by: Richard Schütz <r.schtz@t-online.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Device ID removed 0x10C4/0x8149 for West Mountain Radio Computerized
Battery Analyzer. This device is actually based on a SiLabs C8051Fxxx,
see http://www.etheus.net/SiUSBXp_Linux_Driver for further info.
Alan's commit 335f8514f200e63d689113d29cb7253a5c282967 introduced
.carrier_raised function in several drivers. That also means
tty_port_block_til_ready can now suspend the process trying to open the serial
port when Carrier Detect is low and put it into tty_port.open_wait queue. We
need to wake up the process when Carrier Detect goes high and trigger TTY
hangup when CD goes low.
Some of the devices do not report modem status line changes, or at least we
don't understand the status message, so for those we remove .carrier_raised
again.
Functions set_fan_min() and set_fan_div() assume that the fan_div
values have already been read from the register. The driver currently
doesn't initialize them at load time, they are only set when function
via686a_update_device() is called. This means that set_fan_min() and
set_fan_div() misbehave if, for example, "sensors -s" is called
before any monitoring application (e.g. "sensors") is has been run.
Fix the problem by always initializing the fan_div values at device
bind time.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Guenter Roeck <guenter.roeck@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
When ASPM PM Feature is enabled on UMI link, devices that use ISOC stream of
data transfer may be exposed to longer latency causing less than optimal per-
formance of the device. The longer latencies are normal and are due to link
wake time coming out of low power state which happens frequently to save
power when the link is not active.
The following code will make exception for certain features of ASPM to be by
passed and keep the logic normal state only when the ISOC device is connected
and active. This change will allow the device to run at optimal performance
yet minimize the impact on overall power savings.
Signed-off-by: Alex He <alex.he@amd.com> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
In the vhci_urb_dequeue() function the TCP connection is checked twice.
Each time when the TCP connection is closed the URB is unlinked and given
back. Remove the second attempt of unlinking and giving back of the URB completely.
This patch fixes the bug described at https://bugzilla.kernel.org/show_bug.cgi?id=24872 .
Signed-off-by: Márton Németh <nm127@freemail.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
niu_get_ethtool_tcam_all() assumes that its output buffer is the right
size, and warns before returning if it is not. However, the output
buffer size is under user control and ETHTOOL_GRXCLSRLALL is an
unprivileged ethtool command. Therefore this is at least a local
denial-of-service vulnerability.
Change it to check before writing each entry and to return an error if
the buffer is already full.
Compile-tested only.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Commit da48524eb206 ("Prevent rt_sigqueueinfo and rt_tgsigqueueinfo
from spoofing the signal code") made the check on si_code too strict.
There are several legitimate places where glibc wants to queue a
negative si_code different from SI_QUEUE:
- This was first noticed with glibc's aio implementation, which wants
to queue a signal with si_code SI_ASYNCIO; the current kernel
causes glibc's tst-aio4 test to fail because rt_sigqueueinfo()
fails with EPERM.
- Further examination of the glibc source shows that getaddrinfo_a()
wants to use SI_ASYNCNL (which the kernel does not even define).
The timer_create() fallback code wants to queue signals with SI_TIMER.
As suggested by Oleg Nesterov <oleg@redhat.com>, loosen the check to
forbid only the problematic SI_TKILL case.
Reported-by: Klaus Dittrich <kladit@arcor.de> Acked-by: Julien Tinnes <jln@google.com> Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Userland should be able to trust the pid and uid of the sender of a
signal if the si_code is SI_TKILL.
Unfortunately, the kernel has historically allowed sigqueueinfo() to
send any si_code at all (as long as it was negative - to distinguish it
from kernel-generated signals like SIGILL etc), so it could spoof a
SI_TKILL with incorrect siginfo values.
Happily, it looks like glibc has always set si_code to the appropriate
SI_QUEUE, so there are probably no actual user code that ever uses
anything but the appropriate SI_QUEUE flag.
So just tighten the check for si_code (we used to allow any negative
value), and add a (one-time) warning in case there are binaries out
there that might depend on using other si_code values.
commit 9284bcf checks for proper length of iov entries in
blk_rq_map_user_iov(). But if the map is unaligned, kernel
will break out the loop without checking for the proper length.
So we need to check the proper length before the unalign check.
The sctp_asoc_get_hmac() function iterates through a peer's hmac_ids
array and attempts to ensure that only a supported hmac entry is
returned. The current code fails to do this properly - if the last id
in the array is out of range (greater than SCTP_AUTH_HMAC_ID_MAX), the
id integer remains set after exiting the loop, and the address of an
out-of-bounds entry will be returned and subsequently used in the parent
function, causing potentially ugly memory corruption. This patch resets
the id integer to 0 on encountering an invalid id so that NULL will be
returned after finishing the loop if no valid ids are found.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Don't forget to release the module refcnt if seq_open() returns failure.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: J. Bruce Fields <bfields@fieldses.org> Cc: Neil Brown <neilb@suse.de> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The value of max_output and step_output registers isn't read from the
respective registers. As a result, zero values are returned to the
user through the respective sysfs attributes, instead of the actual
fan control settings.
The problem is fixed by updating the fan max output and fan step
output information from data in registers.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Add necessary alias to autoload ip6ip6 tunnel module.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Since a8f80e8ff94ecba629542d9b4b5f5a8ee3eb565c any process with
CAP_NET_ADMIN may load any module from /lib/modules/. This doesn't mean
that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are
limited to /lib/modules/**. However, CAP_NET_ADMIN capability shouldn't
allow anybody load any module not related to networking.
This patch restricts an ability of autoloading modules to netdev modules
with explicit aliases. This fixes CVE-2011-1019.
Arnd Bergmann suggested to leave untouched the old pre-v2.6.32 behavior
of loading netdev modules by name (without any prefix) for processes
with CAP_SYS_MODULE to maintain the compatibility with network scripts
that use autoloading netdev modules by aliases like "eth0", "wlan0".
Currently there are only three users of the feature in the upstream
kernel: ipip, ip_gre and sit.
root@albatros:~# capsh --drop=$(seq -s, 0 11),$(seq -s, 13 34) --
root@albatros:~# grep Cap /proc/$$/status
CapInh: 0000000000000000
CapPrm: fffffff800001000
CapEff: fffffff800001000
CapBnd: fffffff800001000
root@albatros:~# modprobe xfs
FATAL: Error inserting xfs
(/lib/modules/2.6.38-rc6-00001-g2bf4ca3/kernel/fs/xfs/xfs.ko): Operation not permitted
root@albatros:~# lsmod | grep xfs
root@albatros:~# ifconfig xfs
xfs: error fetching interface information: Device not found
root@albatros:~# lsmod | grep xfs
root@albatros:~# lsmod | grep sit
root@albatros:~# ifconfig sit
sit: error fetching interface information: Device not found
root@albatros:~# lsmod | grep sit
root@albatros:~# ifconfig sit0
sit0 Link encap:IPv6-in-IPv4
NOARP MTU:1480 Metric:1
root@albatros:~# lsmod | grep sit
sit 10457 0
tunnel4 2957 1 sit
For CAP_SYS_MODULE module loading is still relaxed:
[PG: in 2.6.34, the bare MODULE_ALIAS for ipip/tunl0 and ip_gre/gre0
didn't exist, but this adds the limited scope MODULE_ALIAS_NETDEV ones]
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Kees Cook <kees.cook@canonical.com> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
In x25_link_free(), we destroy 'nb' before dereferencing
'nb->dev'. Don't do this, because 'nb' might be freed
by then.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Tested-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Commit 1a855a0606 (2.6.37-rc4) fixed a problem where devices were
re-added when they shouldn't be but caused a regression in a less
common case that means sometimes devices cannot be re-added when they
should be.
In particular, when re-adding a device to an array without metadata
we should always access the device, but after the above commit we
didn't.
This patch sets the In_sync flag in that case so that the re-add
succeeds.
This patch is suitable for any -stable kernel to which 1a855a0606 was
applied.
Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
posix-cpu-timers.c correctly assumes that the dying process does
posix_cpu_timers_exit_group() and removes all !CPUCLOCK_PERTHREAD
timers from signal->cpu_timers list.
But, it also assumes that timer->it.cpu.task is always the group
leader, and thus the dead ->task means the dead thread group.
This is obviously not true after de_thread() changes the leader.
After that almost every posix_cpu_timer_ method has problems.
It is not simple to fix this bug correctly. First of all, I think
that timer->it.cpu should use struct pid instead of task_struct.
Also, the locking should be reworked completely. In particular,
tasklist_lock should not be used at all. This all needs a lot of
nontrivial and hard-to-test changes.
Change __exit_signal() to do posix_cpu_timers_exit_group() when
the old leader dies during exec. This is not the fix, just the
temporary hack to hide the problem for 2.6.37 and stable. IOW,
this is obviously wrong but this is what we currently have anyway:
cpu timers do not work after mt exec.
In theory this change adds another race. The exiting leader can
detach the timers which were attached to the new leader. However,
the window between de_thread() and release_task() is small, we
can pretend that sys_timer_create() was called before de_thread().
When stacking devices, a request_queue is not always available. This
forced us to have a no_cluster flag in the queue_limits that could be
used as a carrier until the request_queue had been set up for a
metadevice.
There were several problems with that approach. First of all it was up
to the stacking device to remember to set queue flag after stacking had
completed. Also, the queue flag and the queue limits had to be kept in
sync at all times. We got that wrong, which could lead to us issuing
commands that went beyond the max scatterlist limit set by the driver.
The proper fix is to avoid having two flags for tracking the same thing.
We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the
block layer merging functions. The queue_limit 'no_cluster' is turned
into 'cluster' to avoid double negatives and to ease stacking.
Clustering defaults to being enabled as before. The queue flag logic is
removed from the stacking function, and explicitly setting the cluster
flag is no longer necessary in DM and MD.
Reported-by: Ed Lin <ed.lin@promise.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Sjoerd Simons reports that, without using position_fix=1, recording
experiences overruns. Work around that by applying the LPIB quirk
for his hardware.
Reported-and-tested-by: Sjoerd Simons <sjoerd@debian.org> Signed-off-by: Daniel T Chen <crimsun@ubuntu.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Thus without the patch, with the boot parameters 'tcb selinux=0', adding
the above 'dont_measure obj_type=var_log_t' rule to the default IMA TCB
measurement policy, would result in nothing being measured. The patch
prevents the default TCB policy from being replaced.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Cc: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: David Safford <safford@watson.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
use mv_xor_slot_cleanup() instead of __mv_xor_slot_cleanup() as the former function
aquires the spin lock that needed to protect the drivers data.
Signed-off-by: Saeed Bishara <saeed@marvell.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The load_mixer_volumes() function, which can be triggered by
unprivileged users via the SOUND_MIXER_SETLEVELS ioctl, is vulnerable to
a buffer overflow. Because the provided "name" argument isn't
guaranteed to be NULL terminated at the expected 32 bytes, it's possible
to overflow past the end of the last element in the mixer_vols array.
Further exploitation can result in an arbitrary kernel write (via
subsequent calls to load_mixer_volumes()) leading to privilege
escalation, or arbitrary kernel reads via get_mixer_levels(). In
addition, the strcmp() may leak bytes beyond the mixer_vols array.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This USB ID is for the WUBI-100GW 802.11g Wireless LAN USB Device that
uses p54usb.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Eduardo Costa <ecosta.tmp@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Source:
http://www.linuxant.com/pipermail/driverloader/2005q3/002307.html
http://wireless.kernel.org/en/users/Drivers/p54/devices (by M. Davis)
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Add an unusual_devs entry for the Samsung YP-CP3 MP4 player.
User was getting the following errors in dmesg:
usb 2-6: reset high speed USB device using ehci_hcd and address 2
usb 2-6: reset high speed USB device using ehci_hcd and address 2
usb 2-6: reset high speed USB device using ehci_hcd and address 2
usb 2-6: USB disconnect, address 2
sd 3:0:0:0: [sdb] Assuming drive cache: write through
sdb:<2>ldm_validate_partition_table(): Disk read failed.
Dev sdb: unable to read RDB block 0
unable to read partition table
[PG: change USB_ --> US_ to match 2.6.34.x naming conventions]
Signed-off-by: Vitaly Kuznetsov <vitty@altlinux.ru> Acked-by: Alan Stern <stern@rowland.harvard.edu> CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The install_special_mapping routine (used, for example, to setup the
vdso) skips the security check before insert_vm_struct, allowing a local
attacker to bypass the mmap_min_addr security restriction by limiting
the available pages for special mappings.
bprm_mm_init() also skips the check, and although I don't think this can
be used to bypass any restrictions, I don't see any reason not to have
the security check.
It's worth noting that Red Hat are shipping with mmap_min_addr set to
4096.
Signed-off-by: Tavis Ormandy <taviso@google.com> Acked-by: Kees Cook <kees@ubuntu.com> Acked-by: Robert Swiecki <swiecki@google.com>
[ Changed to not drop the error code - akpm ] Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The port data structure related to fc_host statistics collection is
not initialized. This causes system crash when reading the fc_host
statistics. The fix is to initialize port structure during driver
attach.
Signed-off-by: Krishna Gudipati <kgudipat@brocade.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
There is a window between hidraw_table check and its dereference.
In that window, the device may be unplugged and removed form the
system and we will then dereference NULL.
Lock that place properly so that either we get NULL and jump out or we
can work with real pointer.
[PG: slightly/trivially reworked for backport to 34]
On platforms with Intel 7500 chipset, there were some reports of system
hang/NMI's during kexec/kdump in the presence of interrupt-remapping enabled.
During kdump, there is a window where the devices might be still using old
kernel's interrupt information, while the kdump kernel is coming up. This can
cause vt-d faults as the interrupt configuration from the old kernel map to
null IRTE entries in the new kernel etc. (with out interrupt-remapping enabled,
we still have the same issue but in this case we will see benign spurious
interrupt hit the new kernel).
Based on platform config settings, these platforms seem to generate NMI/SMI
when a vt-d fault happens and there were reports that the resulting SMI causes
the system to hang.
Fix it by masking vt-d spec defined errors to platform error reporting logic.
VT-d spec related errors are already handled by the VT-d OS code, so need to
report the same error through other channels.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1291667190.2675.8.camel@sbsiddha-MOBL3.sc.intel.com> Reported-by: Max Asbock <masbock@linux.vnet.ibm.com> Reported-and-tested-by: Takao Indoh <indou.takao@jp.fujitsu.com> Acked-by: Chris Wright <chrisw@sous-sol.org> Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
In x2apic mode, we need to set the upper address register of the fault
handling interrupt register of the vt-d hardware. Without this
irq migration of the vt-d fault handling interrupt is broken.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
LKML-Reference: <1291225233.2648.39.camel@sbsiddha-MOBL3> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Chris Wright <chrisw@sous-sol.org> Tested-by: Takao Indoh <indou.takao@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Fault handling is getting enabled after enabling the interrupt-remapping (as
the success of interrupt-remapping can affect the apic mode and hence the
fault handling mode).
Hence there can potentially be some faults between the window of enabling
interrupt-remapping in the vt-d and the fault-handling of the vt-d units.
Handle any previous faults after enabling the vt-d fault handling.
For v2.6.38 cleanup, need to check if we can remove the dmar_fault() in the
enable_intr_remapping() and see if we can enable fault handling along with
enabling intr-remapping.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20101201062244.630417138@intel.com> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Interrupt-remapping gets enabled very early in the boot, as it determines the
apic mode that the processor can use. And the current code enables the vt-d
fault handling before the setup_local_APIC(). And hence the APIC LDR registers
and data structure in the memory may not be initialized. So the vt-d fault
handling in logical xapic/x2apic modes were broken.
Fix this by enabling the vt-d fault handling in the end_local_APIC_setup()
A cleaner fix of enabling fault handling while enabling intr-remapping
will be addressed for v2.6.38. [ Enabling intr-remapping determines the
usage of x2apic mode and the apic mode determines the fault-handling
configuration. ]
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
LKML-Reference: <20101201062244.541996375@intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The vdso Makefile passes linker-style -m options not to the linker but
to gcc. This happens to work with earlier gcc, but fails with gcc
4.6. Pass gcc-style -m options, instead.
Note: all currently supported versions of gcc supports -m32, so there
is no reason to conditionalize it any more.
Reported-by: H. J. Lu <hjl.tools@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <tip-*@git.kernel.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The file_ops struct for the "trace" special file defined llseek as seq_lseek().
However, if the file was opened for writing only, seq_open() was not called,
and the seek would dereference a null pointer, file->private_data.
This patch introduces a new wrapper for seq_lseek() which checks if the file
descriptor is opened for reading first. If not, it does nothing.
Signed-off-by: Slava Pestov <slavapestov@google.com>
LKML-Reference: <1290640396-24179-1-git-send-email-slavapestov@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
With v0.90 metadata, a hot-spare does not become a full member of the
array until recovery is complete. So if we re-add such a device to
the array, we know that all of it is as up-to-date as the event count
would suggest, and so it a bitmap-based recovery is possible.
However with v1.x metadata, the hot-spare immediately becomes a full
member of the array, but it record how much of the device has been
recovered. If the array is stopped and re-assembled recovery starts
from this point.
When such a device is hot-added to an array we currently lose the 'how
much is recovered' information and incorrectly included it as a full
in-sync member (after bitmap-based fixup).
This is wrong and unsafe and could corrupt data.
So be more careful about setting saved_raid_disk - which is what
guides the re-adding of devices back into an array.
The new code matches the code in slot_store which does a similar
thing, which is encouraging.
In these situations, you are usually trying to connect to a new AP, so
keeping TKIP countermeasures active is confusing. This is already how
the driver behaves (inadvertently). However, querying SIOCGIWAUTH may
tell userspace that countermeasures are active when they aren't.
Clear the setting so that the reporting matches what the driver has
done..
Signed-off by: David Kilroy <kilroyd@googlemail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Enable the port when disabling countermeasures, and disable it on
enabling countermeasures.
This bug causes the response of the system to certain attacks to be
ineffective.
It also prevents wpa_supplicant from getting scan results, as
wpa_supplicant disables countermeasures on startup - preventing the
hardware from scanning.
wpa_supplicant works with ap_mode=2 despite this bug because the commit
handler re-enables the port.
The log tends to look like:
State: DISCONNECTED -> SCANNING
Starting AP scan for wildcard SSID
Scan requested (ret=0) - scan timeout 5 seconds
EAPOL: disable timer tick
EAPOL: Supplicant port status: Unauthorized
Scan timeout - try to get results
Failed to get scan results
Failed to get scan results - try scanning again
Setting scan request: 1 sec 0 usec
Starting AP scan for wildcard SSID
Scan requested (ret=-1) - scan timeout 5 seconds
Failed to initiate AP scan.
Reported by: Giacomo Comes <comes@naic.edu>
Signed-off by: David Kilroy <kilroyd@googlemail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Some Panasonic Toughbooks create nodes in module level code.
Module level code is the executable AML code outside of control method,
for example, below AML code creates a node \_SB.PCI0.GFX0.DD02.CUBL
If (\_OSI ("Windows 2006"))
{
Scope (\_SB.PCI0.GFX0.DD02)
{
Name (CUBL, Ones)
...
}
}
Scope() op does not actually create a new object, it refers to an
existing object(\_SB.PCI0.GFX0.DD02 in above example). However, for
Scope(), we want to indeed open a new scope, so the child nodes(CUBL in
above example) can be created correctly under it.
https://bugzilla.kernel.org/show_bug.cgi?id=19462
Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The user-space hibernation sends a wrong notification after the image
restoration because of thinko for the file flag check. RDONLY
corresponds to hibernation and WRONLY to restoration, confusingly.
Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
In ib_uverbs_poll_cq() code there is a potential integer overflow if
userspace passes in a large cmd.ne. The calls to kmalloc() would
allocate smaller buffers than intended, leading to memory corruption.
There iss also an information leak if resp wasn't all used.
Unprivileged userspace may call this function, although only if an
RDMA device that uses this function is present.
Fix this by copying CQ entries one at a time, which avoids the
allocation entirely, and also by moving this copying into a function
that makes sure to initialize all memory copied to userspace.
Special thanks to Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
for his help and advice.
Signed-off-by: Dan Carpenter <error27@gmail.com>
[ Monkey around with things a bit to avoid bad code generation by gcc
when designated initializers are used. - Roland ]
Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
When matching error address to the range contained by one memory node,
we're in valid range when node interleaving
1. is disabled, or
2. enabled and when the address bits we interleave on match the
interleave selector on this node (see the "Node Interleaving" section in
the BKDG for an enlightening example).
Thus, when we early-exit, we need to reverse the compound logic
statement properly.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
When an xprt is created, it has a refcount of 1, and XPT_BUSY is set.
The refcount is *not* owned by the thread that created the xprt
(as is clear from the fact that creators never put the reference).
Rather, it is owned by the absence of XPT_DEAD. Once XPT_DEAD is set,
(And XPT_BUSY is clear) that initial reference is dropped and the xprt
can be freed.
So when a creator clears XPT_BUSY it is dropping its only reference and
so must not touch the xprt again.
However svc_recv, after calling ->xpo_accept (and so getting an XPT_BUSY
reference on a new xprt), calls svc_xprt_recieved. This clears
XPT_BUSY and then svc_xprt_enqueue - this last without owning a reference.
This is dangerous and has been seen to leave svc_xprt_enqueue working
with an xprt containing garbage.
So we need to hold an extra counted reference over that call to
svc_xprt_received.
For safety, any time we clear XPT_BUSY and then use the xprt again, we
first get a reference, and the put it again afterwards.
Note that svc_close_all does not need this extra protection as there are
no threads running, and the final free can only be called asynchronously
from such a thread.
Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The commit 129a84de2347002f09721cda3155ccfd19fade40 (locks: fix F_GETLK
regression (failure to find conflicts)) fixed the posix_test_lock()
function by itself, however, its usage in NFS changed by the commit 9d6a8c5c213e34c475e72b245a8eb709258e968c (locks: give posix_test_lock
same interface as ->lock) remained broken - subsequent NFS-specific
locking code received F_UNLCK instead of the user-specified lock type.
To fix the problem, fl->fl_type needs to be saved before the
posix_test_lock() call and restored if no local conflicts were reported.
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=23892 Tested-by: Alexander Morozov <amorozov@etersoft.ru> Signed-off-by: Sergey Vlasov <vsu@altlinux.ru> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
If vfs_getattr in fill_post_wcc returns an error, we don't
set fh_post_change.
For NFSv4, this can result in set_change_info triggering a BUG_ON.
i.e. fh_post_saved being zero isn't really a bug.
So:
- instead of BUGging when fh_post_saved is zero, just clear ->atomic.
- if vfs_getattr fails in fill_post_wcc, take a copy of i_ctime anyway.
This will be used i seg_change_info, but not overly trusted.
- While we are there, remove the pointless 'if' statements in set_change_info.
There is no harm setting all the values.
Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
After a few unsuccessful NFS mount attempts in which the client and
server cannot agree on an authentication flavor both support, the
client panics. nfs_umount() is invoked in the kernel in this case.
Turns out nfs_umount()'s UMNT RPC invocation causes the RPC client to
write off the end of the rpc_clnt's iostat array. This is because the
mount client's nrprocs field is initialized with the count of defined
procedures (two: MNT and UMNT), rather than the size of the client's
proc array (four).
The fix is to use the same initialization technique used by most other
upper layer clients in the kernel.
Introduced by commit 0b524123, which failed to update nrprocs when
support was added for UMNT in the kernel.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=24302 BugLink: http://bugs.launchpad.net/bugs/683938 Reported-by: Stefan Bader <stefan.bader@canonical.com> Tested-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This fixes a bug as seen on 2.6.32 based kernels where timers got
enqueued on offline cpus.
If a cpu goes offline it might still have pending timers. These will
be migrated during CPU_DEAD handling after the cpu is offline.
However while the cpu is going offline it will schedule the idle task
which will then call tick_nohz_stop_sched_tick().
That function in turn will call get_next_timer_intterupt() to figure
out if the tick of the cpu can be stopped or not. If it turns out that
the next tick is just one jiffy off (delta_jiffies == 1)
tick_nohz_stop_sched_tick() incorrectly assumes that the tick should
not stop and takes an early exit and thus it won't update the load
balancer cpu.
Just afterwards the cpu will be killed and the load balancer cpu could
be the offline cpu.
On 2.6.32 based kernel get_nohz_load_balancer() gets called to decide
on which cpu a timer should be enqueued (see __mod_timer()). Which
leads to the possibility that timers get enqueued on an offline cpu.
These will never expire and can cause a system hang.
This has been observed 2.6.32 kernels. On current kernels
__mod_timer() uses get_nohz_timer_target() which doesn't have that
problem. However there might be other problems because of the too
early exit tick_nohz_stop_sched_tick() in case a cpu goes offline.
The easiest and probably safest fix seems to be to let
get_next_timer_interrupt() just lie and let it say there isn't any
pending timer if the current cpu is offline.
I also thought of moving migrate_[hr]timers() from CPU_DEAD to
CPU_DYING, but seeing that there already have been fixes at least in
the hrtimer code in this area I'm afraid that this could add new
subtle bugs.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101201091109.GA8984@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This patch fixes a hang observed with 2.6.32 kernels where timers got enqueued
on offline cpus.
printk_needs_cpu() may return 1 if called on offline cpus. When a cpu gets
offlined it schedules the idle process which, before killing its own cpu, will
call tick_nohz_stop_sched_tick(). That function in turn will call
printk_needs_cpu() in order to check if the local tick can be disabled. On
offline cpus this function should naturally return 0 since regardless if the
tick gets disabled or not the cpu will be dead short after. That is besides the
fact that __cpu_disable() should already have made sure that no interrupts on
the offlined cpu will be delivered anyway.
In this case it prevents tick_nohz_stop_sched_tick() to call
select_nohz_load_balancer(). No idea if that really is a problem. However what
made me debug this is that on 2.6.32 the function get_nohz_load_balancer() is
used within __mod_timer() to select a cpu on which a timer gets enqueued. If
printk_needs_cpu() returns 1 then the nohz_load_balancer cpu doesn't get
updated when a cpu gets offlined. It may contain the cpu number of an offline
cpu. In turn timers get enqueued on an offline cpu and not very surprisingly
they never expire and cause system hangs.
This has been observed 2.6.32 kernels. On current kernels __mod_timer() uses
get_nohz_timer_target() which doesn't have that problem. However there might be
other problems because of the too early exit tick_nohz_stop_sched_tick() in
case a cpu goes offline.
Easiest way to fix this is just to test if the current cpu is offline and call
printk_tick() directly which clears the condition.
Alternatively I tried a cpu hotplug notifier which would clear the condition,
however between calling the notifier function and printk_needs_cpu() something
could have called printk() again and the problem is back again. This seems to
be the safest fix.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101126120235.406766476@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
projects / karo-tx-linux.git / log