Lockdep has found the real bug, but the output doesn't look right to me:

> =========================================================
> [ INFO: possible irq lock inversion dependency detected ]
> 2.6.33-rc5 #77
> ---------------------------------------------------------
> emacs/1609 just changed the state of lock:
>  (&(&tty->ctrl_lock)->rlock){+.....}, at: [<ffffffff8127c648>] tty_fasync+0xe8/0x190
> but this lock took another, HARDIRQ-unsafe lock in the past:
>  (&(&sighand->siglock)->rlock){-.....}

"HARDIRQ-unsafe" and "this lock took another" looks wrong, afaics.

>   ... key      at: [<ffffffff81c054a4>] __key.46539+0x0/0x8
>   ... acquired at:
>    [<ffffffff81089af6>] __lock_acquire+0x1056/0x15a0
>    [<ffffffff8108a0df>] lock_acquire+0x9f/0x120
>    [<ffffffff81423012>] _raw_spin_lock_irqsave+0x52/0x90
>    [<ffffffff8127c1be>] __proc_set_tty+0x3e/0x150
>    [<ffffffff8127e01d>] tty_open+0x51d/0x5e0

The stack-trace shows that this lock (ctrl_lock) was taken under
->siglock (which is hopefully irq-safe).

This is a clear typo in check_usage_backwards() where we tell the print a
fancy routine we're forwards.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100126181641.GA10460@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Commit 70362511 exposed that f_modown()
should call write_lock_irqsave instead of just write_lock_irq so that
because a caller could have a spinlock held and it would not be good to
renable interrupts.

Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Tavis Ormandy <taviso@google.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Drop EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE flag
  ext4: Fix quota accounting error with fallocate
  ext4: Handle -EDQUOT error on write

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  [WATCHDOG] sbc_fitpc2_wdt: fix I/O space access technique.
  [WATCHDOG] ixp2000: Fix build failure caused by missing include

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ASoC: fix a memory-leak in wm8903
  ALSA: hda - add possibility to choose speakers configuration for 4930g
  ALSA: hda - Fix HP T5735 automute
  ALSA: hda - Turn on EAPD only if available for Realtek codecs
  ALSA: hda - Fix parsing pin node 0x21 on ALC259

* 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Fix leak of free lapic date in kvm_arch_vcpu_init()
  KVM: x86: Fix probable memory leak of vcpu->arch.mce_banks
  KVM: S390: fix potential array overrun in intercept handling
  KVM: fix spurious interrupt with irqfd
  eventfd - allow atomic read and waitqueue remove
  KVM: MMU: bail out pagewalk on kvm_read_guest error
  KVM: properly check max PIC pin in irq route setup
  KVM: only allow one gsi per fd
  KVM: x86: Fix host_mapping_level()
  KVM: powerpc: Show timing option only on embedded
  KVM: Fix race between APIC TMR and IRR

* 'linux-next' of git://git.infradead.org/ubi-2.6:
  UBI: fix memory leak in update path
  UBI: add more checks to chdev open
  UBI: initialise update marker

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  hwmon: (fschmd) Fix a memleak on multiple opens of /dev/watchdog
  hwmon: (asus_atk0110) Do not fail if MBIF is missing
  hwmon: (amc6821) Double unlock bug
  hwmon: (smsc47m1) Fix section mismatch

* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (95 commits)
  drm/radeon/kms: preface warning printk with driver name
  drm/radeon/kms: drop unnecessary printks.
  drm: fix regression in fb blank handling
  drm/radeon/kms: make hibernate work on IGPs
  drm/vmwgfx: Optimize memory footprint for DMA buffers.
  drm/ttm: Allow system memory as a busy placement.
  drm/ttm: Fix race condition in ttm_bo_delayed_delete (v3, final)
  drm/nv50: prevent switching off SOR when in use for DVI-over-DP
  drm/nv50: fail auxch transaction if reply count not what we expect
  drm/nouveau: fix failure path if userspace specifies no valid memtypes
  drm/nouveau: report LVDS as disconnected if lid closed
  drm/radeon/kms: fix legacy get_engine/memory clock
  drm/radeon/kms/atom: atom parser fixes
  drm/radeon/kms: clean up atombios pll code
  drm/radeon/kms: clean up pll struct
  drm/radeon/kms/atom: fix crtc lock ordering
  drm/radeon: r6xx/r7xx possible security issue, system ram access
  drm/radeon/kms: r600/r700 don't test ib if ib initialization fails
  drm/radeon/kms: Forbid creation of framebuffer with no valid GEM object
  drm/radeon/kms: r600 handle irq vector ring overflow
  ...

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc64: Fix IRQ ->set_affinity() methods.
  sparc: cpumask_of_node() should handle -1 as a node
  sparc64: Update defconfig.
  sparc: Add missing SW perf fault events.
  sparc64: Fully support both performance counters.
  sparc64: Add perf callchain support.
  sparc: convert to arch_gettimeoffset()
  sparc: leds_resource.end assigned to itself in clock_board_probe()
  sparc32: Fix page_to_phys().
  sparc: Simplify param.h by simply including <asm-generic/param.h>
  sparc32: Update defconfig.
  SPARC: use helpers for rlimits
  sparc: copy_from_user() should not return -EFAULT

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (42 commits)
  virtio_net: Make delayed refill more reliable
  sfc: Use fixed-size buffers for MCDI NVRAM requests
  sfc: Add workspace for GMAC bug workaround to MCDI MAC_STATS buffer
  tcp_probe: avoid modulus operation and wrap fix
  qlge: Only free resources if they were allocated
  netns xfrm: deal with dst entries in netns
  sky2: revert config space change
  vlan: fix vlan_skb_recv()
  netns xfrm: fix "ip xfrm state|policy count" misreport
  sky2: Enable/disable WOL per hardware device
  net: Fix IPv6 GSO type checks in Intel ethernet drivers
  igb/igbvf: cleanup exception handling in tx_map_adv
  MAINTAINERS: Add Intel igbvf maintainer
  e1000/e1000e: don't use small hardware rx buffers
  fmvj18x_cs: add new id (Panasonic lan & modem card)
  be2net: swap only first 2 fields of mcc_wrb
  Please add support for Microsoft MN-120 PCMCIA network card
  be2net: fix bug in rx page posting
  wimax/i2400m: Add support for more i6x50 SKUs
  e1000e: enhance frame fragment detection
  ...

Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6

* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: (25 commits)
  OMAP2/3: DMTIMER: Clear pending interrupts when stopping a timer
  PM debug: Fix warning when no CONFIG_DEBUG_FS
  OMAP3: PM: DSS PM_WKEN to refill DMA
  OMAP: timekeeping: time should not stop during suspend
  OMAP3: PM: Force write last pad config register into save area
  OMAP: omap3_pm_get_suspend_state() error ignored in pwrdm_suspend_get()
  OMAP3: PM: Enable wake-up from McBSP2, 3 and 4 modules
  OMAP3: PM debug: fix build error when !CONFIG_DEBUG_FS
  OMAP3: PM: Removing redundant and potentially dangerous PRCM configration
  OMAP3: Fixed ARM aux ctrl register save/restore
  OMAP3: CPUidle: Fixed timer resolution
  OMAP3: PM: Remove duplicate code blocks
  OMAP3: PM: Disable interrupt controller AUTOIDLE before WFI
  OMAP3: PM: Enable system control module autoidle
  OMAP3: PM: Ack pending interrupts before entering suspend
  omap: Enable GPMC clock in gpmc_init
  OMAP1 clock: fix for "BUG: spinlock lockup on CPU#0"
  OMAP4: clocks: Fix the clksel_rate struct DPLL divs
  OMAP4: PRCM: Fix the base address for CHIRONSS reg defines
  OMAP: dma_chan[lch_head].flag & OMAP_DMA_ACTIVE tested twice in omap_dma_unlink_lch()
  ...

I have seen RX stalls on a machine that experienced a suspected
OOM.  After the stall, the RX buffer is empty on the guest side
and there are exactly 16 entries available on the host side.  As
the number of entries is less than that required by a maximal
skb, the host cannot proceed.

The guest did not have a refill job scheduled.

My diagnosis is that an OOM had occured, with the delayed refill
job scheduled.  The job was able to allocate at least one skb, but
not enough to overcome the minimum required by the host to proceed.

As the refill job would only reschedule itself if it failed completely
to allocate any skbs, this would lead to an RX stall.

The following patch removes this stall possibility by always
rescheduling the refill job until the ring is totally refilled.

Testing has shown that the RX stall no longer occurs whereas
previously it would occur within a day.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

The low-level MCDI code always uses 32-bit MMIO operations, and
callers must pad input and output buffers to multiples of 4 bytes.
The MCDI NVRAM functions are not doing this.  Also, their buffers are
declared as variable-length arrays with no explicit maximum length.

Switch to a fixed buffer size based on the chunk size used by the
MTD driver (which is a multiple of 4).
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Due to a hardware bug in the SFC9000 family, the firmware must
transfer raw GMAC statistics to host memory before aggregating them
into the cooked (speed-independent) MAC statistics.  Extend the stats
buffer to support this.

The length of the buffer is explicit in the MAC_STATS command, so this
change is backward-compatible on both sides.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

By rounding up the buffer size to power of 2, several expensive
modulus operations can be avoided.  This patch also solves a bug where
the gap need when ring gets full was not being accounted for.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently qlge tries to release regions even if they were not allocated.
This causes messages like the following in the kernel log

Trying to free nonexistent resource <00000000006af400-00000000006af4ff>
Trying to free nonexistent resource <00003c04ff9f4000-00003c04ff9f7fff>
Trying to free nonexistent resource <00003c04ffc00000-00003c04ffcfffff>

This patch fixes the goto logic in order to not release the resources
if they were not allocated.
Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The mdelay function was used between I/O access commands, that causes peak
in CPU usage. Fix it by substitution mdelay to msleep.

Expand usage on fitPC2 compatible boards according to DMI identification.
Signed-off-by: Denis Turischev <denis@compulab.co.il>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

Remember to free the temporary register-cache.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org

In function kvm_arch_vcpu_init(), if the memory malloc for
vcpu->arch.mce_banks is fail, it does not free the memory
of lapic date. This patch fixed it.

Cc: stable@kernel.org
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

vcpu->arch.mce_banks is malloc in kvm_arch_vcpu_init(), but
never free in any place, this may cause memory leak. So this
patch fixed to free it in kvm_arch_vcpu_uninit().

Cc: stable@kernel.org
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

kvm_handle_sie_intercept uses a jump table to get the intercept handler
for a SIE intercept. Static code analysis revealed a potential problem:
the intercept_funcs jump table was defined to contain (0x48 >> 2) entries,
but we only checked for code > 0x48 which would cause an off-by-one
array overflow if code == 0x48.

Use the compiler and ARRAY_SIZE to automatically set the limits.

Cc: stable@kernel.org
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

kvm didn't clear irqfd counter on deassign, as a result we could get a
spurious interrupt when irqfd is assigned back. this leads to poor
performance and, in theory, guest crash.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

KVM needs a wait to atomically remove themselves from the eventfd ->poll()
wait queue head, in order to handle correctly their IRQfd deassign
operation.

This patch introduces such API, plus a way to read an eventfd from its
context.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Avi Kivity <avi@redhat.com>

Exit the guest pagetable walk loop if reading gpte failed. Otherwise its
possible to enter an endless loop processing the previous present pte.

Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Otherwise memory beyond irq_states[16] might be accessed.

Noticed by Juan Quintela.

Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

Looks like repeatedly binding same fd to multiple gsi's with irqfd can
use up a ton of kernel memory for irqfd structures.

A simple fix is to allow each fd to only trigger one gsi: triggering a
storm of interrupts in guest is likely useless anyway, and we can do it
by binding a single gsi to many interrupts if we really want to.

Cc: stable@kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Acked-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

When found a error hva, should not return PAGE_SIZE but the level...

Also clean up the coding style of the following loop.

Cc: stable@kernel.org
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Embedded PowerPC KVM has an exit timing implementation to track and evaluate
how much time was spent in which exit path.

For Book3S, we don't implement it. So let's not expose it as a config option
either.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

When we queue an interrupt to the local apic, we set the IRR before the TMR.
The vcpu can pick up the IRR and inject the interrupt before setting the TMR,
and perhaps even EOI it, causing incorrect behaviour.

The race is really insignificant since it can only occur on the first
interrupt (usually following interrupts will not change TMR), but it's better
closed than open.

Fixed by reordering setting the TMR vs IRR.

Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

When /dev/watchdog gets opened a second time we return -EBUSY, but
we already have got a kref then, so we end up leaking our data struct.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org

MBIF (motherboard identification) is only used to print the name of
the board, it's not essential for the driver; do not fail if it's
missing. Based on Juan's patch.
Signed-off-by: Luca Tettamanti <kronos.it@gmail.com>
Acked-by: Juan RP <xtraeme@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

The mutex gets unlocked after we goto EXIT.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

smsc47m1_restore is called from sm_smsc47m1_exit, which is an __exit
function, so it can't be __init.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Now one can choose speaker configuration in e.g. PulseAudio mixer
Signed-off-by: Łukasz Wojniłowicz <lukasz.wojnilowicz@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

GC is non-existent in netns, so after you hit GC threshold, no new
dst entries will be created until someone triggers cleanup in init_net.

Make xfrm4_dst_ops and xfrm6_dst_ops per-netns.
This is not done in a generic way, because it woule waste
(AF_MAX - 2) * sizeof(struct dst_ops) bytes per-netns.

Reorder GC threshold initialization so it'd be done before registering
XFRM policies.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Obviously, this register had some other impact that is causing
the regression.  Either it is masking some other access or needs
to be reset in some path.

Either, way it is best to just revert the change for 2.6.33

This reverts commit 166a0fd4.
Signed-off-by: David S. Miller <davem@davemloft.net>

This just adds a little more info to the warning for old -ati/mesa
userspaces.
Signed-off-by: Dave Airlie <airlied@redhat.com>

These printks aren't required anymore.
Signed-off-by: Dave Airlie <airlied@redhat.com>