pcpu_embed_first_chunk() allocates memory for each node, copies percpu
data and frees unused portions of it before proceeding to the next
group.  This assumes that allocations for different nodes doesn't
overlap; however, depending on memory topology, the bootmem allocator
may end up allocating memory from a different node than the requested
one which may overlap with the portion freed from one of the previous
percpu areas.  This leads to percpu groups for different nodes
overlapping which is a serious bug.

This patch separates out copy & partial free from the allocation loop
such that all allocations are complete before partial frees happen.

This also fixes overlapping frees which could happen on allocation
failure path - out_free_areas path frees whole groups but the groups
could have portions freed at that point.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Reported-by: "Pavel V. Panteleev" <pp_84@mail.ru>
Tested-by: "Pavel V. Panteleev" <pp_84@mail.ru>
LKML-Reference: <E1SNhwY-0007ui-V7.pp_84-mail-ru@f220.mail.ru>

Pull drm fixes from Dave Airlie:
 "Two fixes from Intel, one a regression, one because I merged an early
  version of a fix.

  Also the nouveau revert of the i2c code that was tested on the list."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau/i2c: resume use of i2c-algo-bit, rather than custom stack
  drm/i915: Do no set Stencil Cache eviction LRA w/a on gen7+
  drm/i915: disable sdvo hotplug on i945g/gm

Merge tag 'stable/for-linus-3.4-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull xen fixes from Konrad Rzeszutek Wilk:
 - fix to Kconfig to make it fit within 80 line characters,
 - two bootup fixes (AMD 8-core and with PCI BIOS),
 - cleanup code in a Xen PV fb driver,
 - and a crash fix when trying to see non-existent PTE's

* tag 'stable/for-linus-3.4-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/Kconfig: fix Kconfig layout
  xen/pci: don't use PCI BIOS service for configuration space accesses
  xen/pte: Fix crashes when trying to see non-existent PGD/PMD/PUD/PTEs
  xen/apic: Return the APIC ID (and version) for CPU 0.
  drivers/video/xen-fbfront.c: add missing cleanup code

Pull two percpu fixes from Tejun Heo:
 "One adds missing KERN_CONT on split printk()s and the other makes
  the percpu allocator avoid using PMD_SIZE as atom_size on x86_32.

  Using PMD_SIZE led to vmalloc area exhaustion on certain
  configurations (x86_32 android) and the only cost of using PAGE_SIZE
  instead is static percpu area not being aligned to large page
  mapping."

* 'for-3.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu, x86: don't use PMD_SIZE as embedded atom_size on 32bit
  percpu: use KERN_CONT in pcpu_dump_alloc_info()

Pull ARM fixes from Russell King:
 "This is mainly audit fixes, found by folks who happened to enable this
  feature and then found it broke their user applications."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7414/1: SMP: prevent use of the console when using idmap_pgd
  ARM: 7412/1: audit: use only AUDIT_ARCH_ARM regardless of endianness
  ARM: 7411/1: audit: fix treatment of saved ip register during syscall tracing
  ARM: 7410/1: Add extra clobber registers for assembly in kernel_execve

With the embed percpu first chunk allocator, x86 uses either PAGE_SIZE
or PMD_SIZE for atom_size.  PMD_SIZE is used when CPU supports PSE so
that percpu areas are aligned to PMD mappings and possibly allow using
PMD mappings in vmalloc areas in the future.  Using larger atom_size
doesn't waste actual memory; however, it does require larger vmalloc
space allocation later on for !first chunks.

With reasonably sized vmalloc area, PMD_SIZE shouldn't be a problem
but x86_32 at this point is anything but reasonable in terms of
address space and using larger atom_size reportedly leads to frequent
percpu allocation failures on certain setups.

As there is no reason to not use PMD_SIZE on x86_64 as vmalloc space
is aplenty and most x86_64 configurations support PSE, fix the issue
by always using PMD_SIZE on x86_64 and PAGE_SIZE on x86_32.

v2: drop cpu_has_pse test and make x86_64 always use PMD_SIZE and
    x86_32 PAGE_SIZE as suggested by hpa.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Yanmin Zhang <yanmin.zhang@intel.com>
Reported-by: ShuoX Liu <shuox.liu@intel.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <4F97BA98.6010001@intel.com>
Cc: stable@vger.kernel.org

Fit it into 80 columns so that it is readable in menuconfig.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The accessing PCI configuration space with the PCI BIOS32 service does
not work in PV guests.

On systems without MMCONFIG or where the BIOS hasn't marked the
MMCONFIG region as reserved in the e820 map, the BIOS service is
probed (even though direct access is preferred) and this hangs.

CC: stable@kernel.org
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
[v1: Fixed compile error when CONFIG_PCI is not set]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

If I try to do "cat /sys/kernel/debug/kernel_page_tables"
I end up with:

BUG: unable to handle kernel paging request at ffffc7fffffff000
IP: [<ffffffff8106aa51>] ptdump_show+0x221/0x480
PGD 0
Oops: 0000 [#1] SMP
CPU 0
.. snip..
RAX: 0000000000000000 RBX: ffffc00000000fff RCX: 0000000000000000
RDX: 0000800000000000 RSI: 0000000000000000 RDI: ffffc7fffffff000

which is due to the fact we are trying to access a PFN that is not
accessible to us. The reason (at least in this case) was that
PGD[256] is set to __HYPERVISOR_VIRT_START which was setup (by the
hypervisor) to point to a read-only linear map of the MFN->PFN array.
During our parsing we would get the MFN (a valid one), try to look
it up in the MFN->PFN tree and find it invalid and return ~0 as PFN.
Then pte_mfn_to_pfn would happilly feed that in, attach the flags
and return it back to the caller. 'ptdump_show' bitshifts it and
gets and invalid value that it tries to dereference.

Instead of doing all of that, we detect the ~0 case and just
return !_PAGE_PRESENT.

This bug has been in existence .. at least until 2.6.37 (yikes!)

CC: stable@kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

On x86_64 on AMD machines where the first APIC_ID is not zero, we get:

ACPI: LAPIC (acpi_id[0x01] lapic_id[0x10] enabled)
BIOS bug: APIC version is 0 for CPU 1/0x10, fixing up to 0x10
BIOS bug: APIC version mismatch, boot CPU: 0, CPU 1: version 10

which means that when the ACPI processor driver loads and
tries to parse the _Pxx states it fails to do as, as it
ends up calling acpi_get_cpuid which does this:

for_each_possible_cpu(i) {
        if (cpu_physical_id(i) == apic_id)
                return i;
}

And the bootup CPU, has not been found so it fails and returns -1
for the first CPU - which then subsequently in the loop that
"acpi_processor_get_info" does results in returning an error, which
means that "acpi_processor_add" failing and per_cpu(processor)
is never set (and is NULL).

That means that when xen-acpi-processor tries to load (much much
later on) and parse the P-states it gets -ENODEV from
acpi_processor_register_performance() (which tries to read
the per_cpu(processor)) and fails to parse the data.
Reported-by-and-Tested-by: Stefan Bader <stefan.bader@canonical.com>
Suggested-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
[v2: Bit-shift APIC ID by 24 bits]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The operations in the subsequent error-handling code appear to be also
useful here.
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
[v1: Collapse some of the error handling functions]
[v2: Fix compile warning]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Previous issues with i2c-algo-bit have now been resolved.

This is a revert of f553b79c mostly,
due to fixes in the i2c core repairing the original issue, this code
isn't required and was causing regressions.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reported-by: Nick Bowler <nbowler@elliptictech.com>
Tested-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Daniel wrote:

2 little patches:
- One regression fix to disable sdvo hotplug on broken hw.
- One patch to upconvert the snb hang workaround from patch v1 to patch
 v2.

* 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel:
  drm/i915: Do no set Stencil Cache eviction LRA w/a on gen7+
  drm/i915: disable sdvo hotplug on i945g/gm

I've flagged this while reviewing the first version and Ken Graunke
fixed it up in v2, but unfortunately Dave Airlie picked up the wrong
version.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Kenneth Graunke <kenneth@whitecape.org>
Cc: stable@kernel.org
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Chris Wilson dug out a hw erratum saying that there's noise on the
interrupt line on i945G chips. We also have a bug report from a i945GM
chip with an sdvo hotplug interrupt storm (and no apparent cause).

Play it safe and disable sdvo hotplug on all i945 variants.

Note that this is a regression that has been introduced in 3.1,
when we've enabled sdvo hotplug support with

commit cc68c81a
Author: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
Date:   Wed Sep 21 17:13:30 2011 +0100

    drm/i915: Enable SDVO hotplug interrupts for HDMI and DVI

Cc: stable@kernel.org
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=38442Reported-and-tested-by: Dominik Köppl <dominik@devwork.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Commit ce7e5d2d ("x86: fix broken TASK_SIZE for ia32_aout") breaks
kernel builds when "CONFIG_IA32_AOUT=m" with

  ERROR: "set_personality_ia32" [arch/x86/ia32/ia32_aout.ko] undefined!
  make[1]: *** [__modpost] Error 1

The entry point needs to be exported.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Al Viro <viro@zeniv.linux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull x86 fixes form Peter Anvin

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  intel_mid_powerbtn: mark irq as IRQF_NO_SUSPEND
  arch/x86/platform/geode/net5501.c: change active_low to 0 for LED driver
  x86, relocs: Remove an unused variable
  asm-generic: Use __BITS_PER_LONG in statfs.h
  x86/amd: Re-enable CPU topology extensions in case BIOS has disabled it

Pull btrfs fixes from Chris Mason:
 "The big ones here are a memory leak we introduced in rc1, and a
  scheduling while atomic if the transid on disk doesn't match the
  transid we expected.  This happens for corrupt blocks, or out of date
  disks.

  It also fixes up the ioctl definition for our ioctl to resolve logical
  inode numbers.  The __u32 was a merging error and doesn't match what
  we ship in the progs."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: avoid sleeping in verify_parent_transid while atomic
  Btrfs: fix crash in scrub repair code when device is missing
  btrfs: Fix mismatching struct members in ioctl.h
  Btrfs: fix page leak when allocing extent buffers
  Btrfs: Add properly locking around add_root_to_dirty_list

Setting TIF_IA32 in load_aout_binary() used to be enough; these days
TASK_SIZE is controlled by TIF_ADDR32 and that one doesn't get set
there.  Switch to use of set_personality_ia32()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

verify_parent_transid needs to lock the extent range to make
sure no IO is underway, and so it can safely clear the
uptodate bits if our checks fail.

But, a few callers are using it with spinlocks held.  Most
of the time, the generation numbers are going to match, and
we don't want to switch to a blocking lock just for the error
case.  This adds an atomic flag to verify_parent_transid,
and changes it to return EAGAIN if it needs to block to
properly verifiy things.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Commit 4e8ee7de (ARM: SMP: use
idmap_pgd for mapping MMU enable during secondary booting)
switched secondary boot to use idmap_pgd, which is initialized
during early_initcall, instead of a page table initialized during
__cpu_up.  This causes idmap_pgd to contain the static mappings
but be missing all dynamic mappings.

If a console is registered that creates a dynamic mapping, the
printk in secondary_start_kernel will trigger a data abort on
the missing mapping before the exception handlers have been
initialized, leading to a hang.  Initial boot is not affected
because no consoles have been registered, and resume is usually
not affected because the offending console is suspended.
Onlining a cpu with hotplug triggers the problem.

A workaround is to the printk in secondary_start_kernel until
after the page tables have been switched back to init_mm.

Cc: <stable@vger.kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull alpha fixes from Matt Turner:
 "My alpha tree is back up (after taking quite some time to get my GPG
  key signed).  It contains just some simple fixes."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha:
  alpha: silence 'const' warning in sys_marvel.c
  alpha: include module.h to fix modpost on Tsunami
  alpha: properly define get/set_rtc_time on Marvel/SMP
  alpha: VGA_HOSE depends on VGA_CONSOLE

The test in pdc_console_tty_close '!tty->count' was always wrong
because tty->count is decremented after tty->ops->close is called and
thus can never be zero. Hence the 'then' branch was never executed and
the timer never deleted.

This did not matter until commit 5dd5bc40 ("TTY: pdc_cons, use
tty_port").  There we needed to set TTY in tty_port to NULL, but this
never happened due to the bug above.

So change the test to really trigger at the last close by changing the
condition to 'tty->count == 1'.

Well, the driver should not touch tty->count at all.  It should use
tty_port->count and count open count there itself.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-and-tested-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull sound sound fixes from Takashi Iwai:
 "As good as nothing exciting here; just a few trivial fixes for various
  ASoC stuff."

* tag 'sound-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ASoC: omap-pcm: Free dma buffers in case of error.
  ASoC: s3c2412-i2s: Fix dai registration
  ASoC: wm8350: Don't use locally allocated codec struct
  ASoC: tlv312aic23: unbreak resume
  ASoC: bf5xx-ssm2602: Set DAI format
  ASoC: core: check of_property_count_strings failure
  ASoC: dt: sgtl5000.txt: Add description for 'reg' field
  ASoC: wm_hubs: Make sure we don't disable differential line outputs

Pull an ACPI patch from Len Brown:
 "It fixes a D3 issue new in 3.4-rc1."

By Lin Ming via Len Brown:
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  ACPI: Fix D3hot v D3cold confusion

Currently, we'll try mounting any device who's major device number is
UNNAMED_MAJOR as NFS root.  This would happen for non-NFS devices as
well (such as 9p devices) but it wouldn't cause any issues since
mounting the device as NFS would fail quickly and the code proceeded to
doing the proper mount:

       [  101.522716] VFS: Unable to mount root fs via NFS, trying floppy.
       [  101.534499] VFS: Mounted root (9p filesystem) on device 0:18.

Commit 6829a048102a ("NFS: Retry mounting NFSROOT") introduced retries
when mounting NFS root, which means that now we don't immediately fail
and instead it takes an additional 90+ seconds until we stop retrying,
which has revealed the issue this patch fixes.

This meant that it would take an additional 90 seconds to boot when
we're not using a device type which gets detected in order before NFS.

This patch modifies the NFS type check to require device type to be
'Root_NFS' instead of requiring the device to have an UNNAMED_MAJOR
major.  This makes boot process cleaner since we now won't go through
the NFS mounting code at all when the device isn't an NFS root
("/dev/nfs").
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The machine endianness has no direct correspondence to the syscall ABI,
so use only AUDIT_ARCH_ARM when identifying the ABI to the audit tools
in userspace.

Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The ARM audit code incorrectly uses the saved application ip register
value to infer syscall entry or exit. Additionally, the saved value will
be clobbered if the current task is not being traced, which can lead to
libc corruption if ip is live (apparently glibc uses it for the TLS
pointer).

This patch fixes the syscall tracing code so that the why parameter is
used to infer the syscall direction and the saved ip is only updated if
we know that we will be signalling a ptrace trap.
Reported-and-Tested-by: Jon Masters <jcm@jonmasters.org>

Cc: stable@vger.kernel.org
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The inline assembly in kernel_execve() uses r8 and r9.  Since this
code sequence does not return, it usually doesn't matter if the
register clobber list is accurate.  However, I saw a case where a
particular version of gcc used r8 as an intermediate for the value
eventually passed to r9.  Because r8 is used in the inline
assembly, and not mentioned in the clobber list, r9 was set
to an incorrect value.

This resulted in a kernel panic on execution of the first user-space
program in the system.  r9 is used in ret_to_user as the thread_info
pointer, and if it's wrong, bad things happen.

Cc: <stable@vger.kernel.org>
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ASoC: Updates for 3.4

Nothing terribly exciting here, a bunch of small and simple fixes
scattered around the place.

Before this patch, ACPI_STATE_D3 incorrectly referenced D3hot
in some places, but D3cold in other places.

After this patch, ACPI_STATE_D3 always means ACPI_STATE_D3_COLD;
and all references to D3hot use ACPI_STATE_D3_HOT.

ACPI's _PR3 method is used to enter both D3hot and D3cold states.
What distinguishes D3hot from D3cold is the presence _PR3
(Power Resources for D3hot)  If these resources are all ON,
then the state is D3hot.  If _PR3 is not present,
or all _PR0 resources for the devices are OFF,
then the state is D3cold.

This patch applies after Linux-3.4-rc1.
A future syntax cleanup may remove ACPI_STATE_D3
to emphasize that it always means ACPI_STATE_D3_COLD.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>

Commit ec81aecb ("hfs: fix a potential buffer overflow") fixed a few
potential buffer overflows in the hfs filesystem.  But as Timo Warns
pointed out, these changes also need to be made on the hfsplus
filesystem as well.
Reported-by: Timo Warns <warns@pre-sense.de>
Acked-by: WANG Cong <amwang@redhat.com>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Cc: Sage Weil <sage@newdream.net>
Cc: Eugene Teo <eteo@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dave Anderson <anderson@redhat.com>
Cc: stable <stable@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull timer fix from Thomas Gleixner.

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rtc: Fix possible null pointer dereference in rtc-mpc5121.c

Pull CIFS fixes from Steve French.

* git://git.samba.org/sfrench/cifs-2.6:
  fs/cifs: fix parsing of dfs referrals
  cifs: make sure we ignore the credentials= and cred= options
  [CIFS] Update cifs version to 1.78
  cifs - check S_AUTOMOUNT in revalidate
  cifs: add missing initialization of server->req_lock
  cifs: don't cap ra_pages at the same level as default_backing_dev_info
  CIFS: Fix indentation in cifs_show_options

Remove myself as cpufreq maintainer.
x86 driver changes can go through the regular x86/ACPI trees.
ARM driver changes through the ARM trees.
cpufreq core changes are rare these days, and can just go to lkml/direct.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The normal read_seqcount_begin() function will wait for any current
writers to exit their critical region by looping until the sequence
count is even.

That "wait for sequence count to stabilize" is the right thing to do if
the read-locker will just retry the whole operation on contention: no
point in doing a potentially expensive reader sequence if we know at the
beginning that we'll just end up re-doing it all.

HOWEVER.  Some users don't actually retry the operation, but instead
will abort and do the operation with proper locking.  So the sequence
count case may be the optimistic quick case, but in the presense of
writers you may want to do full locking in order to guarantee forward
progress.  The prime example of this would be the RCU name lookup.

And in that case, you may well be better off without the "retry early",
and are in a rush to instead get to the failure handling.  Thus this
"raw" interface that just returns the sequence number without testing it
- it just forces the low bit to zero so that read_seqcount_retry() will
always fail such a "active concurrent writer" scenario.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We really need to use a ACCESS_ONCE() on the sequence value read in
__read_seqcount_begin(), because otherwise the compiler might end up
reloading the value in between the test and the return of it.  As a
result, it might end up returning an odd value (which means that a write
is in progress).

If the reader is then fast enough that that odd value is still the
current one when the read_seqcount_retry() is done, we might end up with
a "successful" read sequence, even despite the concurrent write being
active.

In practice this probably never really happens - there just isn't
anything else going on around the read of the sequence count, and the
common case is that we end up having a read barrier immediately
afterwards.

So the code sequence in which gcc might decide to reaload from memory is
small, and there's no reason to believe it would ever actually do the
reload.  But if the compiler ever were to decide to do so, it would be
incredibly annoying to debug.  Let's just make sure.

Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>