Add helper functions to read and write struct timeval and struct
timespec from userspace.  We already had helper functions for reading
and writing struct compat_timespec; add a set of functions to do the
same with struct timeval, and add a second suite of functions which
can be sensitive to COMPAT_USE_64BIT_TIME and access either 32- or
64-bit time structures.

This also exports these helper functions to modules.

Rename the existing inlines for converting between struct
compat_timeval and native struct timespec so we can have a saner
naming convention for the exported functions.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Allow a compatibility ABI to use a 64-bit time_t and 64-bit members in
struct timeval and struct timespec to avoid the Y2038 problem.

This will be used for the x32 ABI.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Change <linux/sysinfo.h> to use explicitly sized types.  Replace
long/unsigned long with __kernel_[u]long_t so that a non-legacy 32-bit
ABI running on a 64-bit kernel can export those as 64-bit types.

Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

This is the same as the 64-bit posix_types.h, except that
__kernel_[u]long_t is defined to be [unsigned] long long and therefore
64 bits.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Introduce __kernel_[u]long_t, which allows an ABI to override all
defaults of type [unsigned] long.

This enables x32 and potentially other 32-bit userspace on 64-bit
kernel ABIs.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

struct sysinfo is just about the only thing exported to userspace from
<linux/kernel.h>, so move it into a separate header file with a
residual #include in <linux/kernel.h>.

Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org

Use explicit sizes (__u64) instead of implicit sizes (unsigned long)
in the definition for sigcontext.h; this will allow this structure to
be shared between the x86-64 native ABI and the x32 ABI.

Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org

Factor out IA32 (compatibility instruction set) from 32-bit address
space in the thread_info flags; this is a precondition patch for x32
support.

Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org

Delete the __FD_*() functions for operating on fd_set structs from
linux/time.h as they're no longer used within the kernel with the preceding
patch and are not exported to userspace.

Whilst linux/time.h *does* export the FD_*() equivalents as wrappers around
__FD_*(), userspace provides its own definition of __FD_*().

Note that the definition of FD_ZERO() in linux/time.h may not be used with the
fd_sets associated with struct fdtable as the fd_set may have been allocated in
a truncated fashion.

Signed-off-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20120216175006.23314.18984.stgit@warthog.procyon.org.uk


Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>

Replace the fd_sets in struct fdtable with an array of unsigned longs and then
use the standard non-atomic bit operations rather than the FD_* macros.

This:

 (1) Removes the abuses of struct fd_set:

     (a) Since we don't want to allocate a full fd_set the vast majority of the
     	 time, we actually, in effect, just allocate a just-big-enough array of
     	 unsigned longs and cast it to an fd_set type - so why bother with the
     	 fd_set at all?

     (b) Some places outside of the core fdtable handling code (such as
     	 SELinux) want to look inside the array of unsigned longs hidden inside
     	 the fd_set struct for more efficient iteration over the entire set.

 (2) Eliminates the use of FD_*() macros in the kernel completely.

 (3) Permits the __FD_*() macros to be deleted entirely where not exposed to
     userspace.

Signed-off-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20120216174954.23314.48147.stgit@warthog.procyon.org.uk


Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>

Wrap accesses to the fd_sets in struct fdtable (for recording open files and
close-on-exec flags) so that we can move away from using fd_sets since we
abuse the fd_set structs by not allocating the full-sized structure under
normal circumstances and by non-core code looking at the internals of the
fd_sets.

The first abuse means that use of FD_ZERO() on these fd_sets is not permitted,
since that cannot be told about their abnormal lengths.

This introduces six wrapper functions for setting, clearing and testing
close-on-exec flags and fd-is-open flags:

	void __set_close_on_exec(int fd, struct fdtable *fdt);
	void __clear_close_on_exec(int fd, struct fdtable *fdt);
	bool close_on_exec(int fd, const struct fdtable *fdt);
	void __set_open_fd(int fd, struct fdtable *fdt);
	void __clear_open_fd(int fd, struct fdtable *fdt);
	bool fd_is_open(int fd, const struct fdtable *fdt);

Note that I've prepended '__' to the names of the set/clear functions because
they require the caller to hold a lock to use them.

Note also that I haven't added wrappers for looking behind the scenes at the
the array.  Possibly that should exist too.

Signed-off-by: David Howells <dhowells@redhat.com>
Link: http://lkml.kernel.org/r/20120216174942.23314.1364.stgit@warthog.procyon.org.uk


Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>

<asm/posix_types.h> includes a set of macros that operate on file
descriptors.  Way long ago those were exported to user space, but
nowadays they are #ifdef __KERNEL__.

However, they are nothing but standard (nonatomic) bit operations, and
we already have optimized versions of bit operations in the kernel.
We can't include <linux/bitops.h> in <asm/posix_types.h> but we can
move the definitions to <linux/time.h> and define them there in terms
of standard kernel bitops.

[ v2: folds the following fixes in:

  a) Stray space in __FD_SET(), reported by Andrew Morton
  b) #include <linux/string.h> needed for memset(), reported by Tony Luck ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-22-git-send-email-hpa@zytor.com
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>

Change the xtensa architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-21-git-send-email-hpa@zytor.com
Cc: Chris Zankel <chris@zankel.net>

Change the x86 architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-20-git-send-email-hpa@zytor.com
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>

Change the sparc architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/1328677745-20121-19-git-send-email-hpa@zytor.com

Remove type overrides in <asm/posix_types.h> for the sh architecture
that are no longer necessary.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-18-git-send-email-hpa@zytor.com
Cc: Paul Mundt <lethal@linux-sh.org>

Change the s390 architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/1328677745-20121-17-git-send-email-hpa@zytor.com
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <linux390@de.ibm.com>

Change the powerpc architecture to use <asm-generic/posix_types.h>.

[ v2: fix the definition for __kernel_ssize_t ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-16-git-send-email-hpa@zytor.com
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>

Change the parisc architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-15-git-send-email-hpa@zytor.com
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: James Bottomley <jejb@parisc-linux.org>

Change the mn10300 architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-14-git-send-email-hpa@zytor.com
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>

Change the mips architecture to use <asm-generic/posix_types.h>.

[ v2: remove redundant definition of __kernel_loff_t ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-13-git-send-email-hpa@zytor.com
Cc: Ralf Baechle <ralf@linux-mips.org>

Change the m68k architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-12-git-send-email-hpa@zytor.com
Cc: Geert Uytterhoeven <geert@linux-m68k.org>

Change the m32r architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-11-git-send-email-hpa@zytor.com
Cc: Hirokazu Takata <takata@linux-m32r.org>

Change the ia64 architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-10-git-send-email-hpa@zytor.com
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>

Change the h8300 architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-9-git-send-email-hpa@zytor.com
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>

Change the frv architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-8-git-send-email-hpa@zytor.com
Cc: David Howells <dhowells@redhat.com>

Change the cris architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Mikael Starvik <starvik@axis.com>
Link: http://lkml.kernel.org/r/1328677745-20121-7-git-send-email-hpa@zytor.com

Change the avr32 architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-6-git-send-email-hpa@zytor.com
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>

Change the arm architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/1328677745-20121-5-git-send-email-hpa@zytor.com

Change the alpha architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-4-git-send-email-hpa@zytor.com
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>

__kernel_fsid_t has members of type "long" on at least one
architecture (MIPS32), so make it possible to override the definition.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-3-git-send-email-hpa@zytor.com
Cc: Arnd Bergmann <arnd@arndb.de>

All ports use unsigned int for __kernel_[ug]id32_t, but not all ports
use unsigned int for __kernel_[ug]id_t.  Thus, change the default for
the "32" types so ports don't need to override them.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-2-git-send-email-hpa@zytor.com
Cc: Arnd Bergmann <arnd@arndb.de>

One patch fixes an bug in the ARM/MSM IOMMU code which returned sucess
in the unmap function even when an error occured and the other patch
adds a workaround into the AMD IOMMU driver to better handle broken IVRS
ACPI tables (this patch fixes the case when a device is not listed in
the table but actually translated by the iommu).

* 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/msm: Fix error handling in msm_iommu_unmap()
  iommu/amd: Work around broken IVRS tables

This series contains pending target bug-fixes and cleanups for v3.3-rc3
that have been addressed the past weeks in lio-core.git.

Some of the highlights include:

 - Fix handling for control CDBs with data greater than PAGE_SIZE (andy)
 - Use IP_FREEBIND for iscsi-target to address network portal creation
   issues with systemd (dax)
 - Allow PERSISTENT RESERVE IN for non-reservation holder (marco)
 - Fix iblock se_dev_attrib.unmap_granularity (marco)
 - Fix unsupported WRITE_SAME sense payload handling (martin)
 - Add workaround for zero-length control CDB handling (nab)
 - Fix discovery with INADDR_ANY and IN6ADDR_ANY_INIT (nab)
 - Fix target_submit_cmd() exception handling (nab)
 - Return correct ASC for unimplemented VPD pages (roland)
 - Don't zero pages used for data buffers (roland)
 - Fix return code of core_tpg_.*_lun (sebastian)

* '3.3-rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (26 commits)
  target: Fix unsupported WRITE_SAME sense payload
  iscsi: use IP_FREEBIND socket option
  iblock: fix handling of large requests
  target: handle empty string writes in sysfs
  iscsi_target: in_aton needs linux/inet.h
  target: Fix iblock se_dev_attrib.unmap_granularity
  target: Fix target_submit_cmd() exception handling
  target: Change target_submit_cmd() to return void
  target: accept REQUEST_SENSE with 18bytes
  target: Fail INQUIRY commands with EVPD==0 but PAGE CODE!=0
  target: Return correct ASC for unimplemented VPD pages
  iscsi-target: Fix discovery with INADDR_ANY and IN6ADDR_ANY_INIT
  target: Allow control CDBs with data > 1 page
  iscsi-target: Fix up a few assignments
  iscsi-target: make one-bit bitfields unsigned
  iscsi-target: Fix double list_add with iscsit_alloc_buffs reject
  iscsi-target: Fix reject release handling in iscsit_free_cmd()
  target: fix return code of core_tpg_.*_lun
  target: use save/restore lock primitive in core_dec_lacl_count()
  target: avoid multiple outputs in scsi_dump_inquiry()
  ...

Some simple md-related fixes.

1/ two small fixes to ensure we handle an interrupted resync properly.
2/ avoid loading the bitmap multiple times in dm-raid

* tag 'md-3.3-fixes' of git://neil.brown.name/md:
  md: two small fixes to handling interrupt resync.
  Prevent DM RAID from loading bitmap twice.

SPI bug fixes for v3.3-rc2

Minor SPI device driver changes.  A rename of the pch_spi_pcidev symbol
that merely eliminates a modpost warning, and a Kconfig change to allow
the Samsung spi driver to build on EXYNOS.

* tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  spi-topcliff-pch: rename pch_spi_pcidev to pch_spi_pcidev_driver
  spi: Add spi-s3c64xx driver dependency on ARCH_EXYNOS4

Five fixes

* branch 'akpm':
  pcmcia: fix socket refcount decrementing on each resume
  mm: fix UP THP spin_is_locked BUGs
  drivers/leds/leds-lm3530.c: fix setting pltfm->als_vmax
  mm: compaction: check for overlapping nodes during isolation for migration
  nilfs2: avoid overflowing segment numbers in nilfs_ioctl_clean_segments()

This fixes a memory-corrupting bug: not only does it cause the warning,
but as a result of dropping the refcount to zero, it causes the
pcmcia_socket0 device structure to be freed while it still has
references, causing slab caches corruption.  A fatal oops quickly
follows this warning - often even just a 'dmesg' following the warning
causes the kernel to oops.

While testing suspend/resume on an ARM device with PCMCIA support, and a
CF card inserted, I found that after five suspend and resumes, the
kernel would complain, and shortly die after with slab corruption.

  WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()

As the message doesn't give a clue about which kobject, and the built-in
debugging in drivers/base/power/main.c happens too late, this was added
right before each get_device():

  printk("%s: %p [%s] %u\n", __func__, dev, kobject_name(&dev->kobj), atomic_read(&dev->kobj.kref.refcount));

and on the 3rd s2ram cycle, the following behaviour observed:

On the 3rd suspend/resume cycle:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 3
  dpm_suspend: c1a0d998 [pcmcia_socket0] 3
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 3
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 3
  dpm_resume: c1a0d998 [pcmcia_socket0] 3
  dpm_complete: c1a0d998 [pcmcia_socket0] 2

4th:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 2
  dpm_suspend: c1a0d998 [pcmcia_socket0] 2
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 2
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 2
  dpm_resume: c1a0d998 [pcmcia_socket0] 2
  dpm_complete: c1a0d998 [pcmcia_socket0] 1

5th:

  dpm_prepare: c1a0d998 [pcmcia_socket0] 1
  dpm_suspend: c1a0d998 [pcmcia_socket0] 1
  dpm_suspend_noirq: c1a0d998 [pcmcia_socket0] 1
  dpm_resume_noirq: c1a0d998 [pcmcia_socket0] 1
  dpm_resume: c1a0d998 [pcmcia_socket0] 1
  dpm_complete: c1a0d998 [pcmcia_socket0] 0
  ------------[ cut here ]------------
  WARNING: at include/linux/kref.h:41 kobject_get+0x28/0x50()
  Modules linked in: ucb1x00_core
  Backtrace:
  [<c0212090>] (dump_backtrace+0x0/0x110) from [<c04799dc>] (dump_stack+0x18/0x1c)
  [<c04799c4>] (dump_stack+0x0/0x1c) from [<c021cba0>] (warn_slowpath_common+0x50/0x68)
  [<c021cb50>] (warn_slowpath_common+0x0/0x68) from [<c021cbdc>] (warn_slowpath_null+0x24/0x28)
  [<c021cbb8>] (warn_slowpath_null+0x0/0x28) from [<c0335374>] (kobject_get+0x28/0x50)
  [<c033534c>] (kobject_get+0x0/0x50) from [<c03804f4>] (get_device+0x1c/0x24)
  [<c0388c90>] (dpm_complete+0x0/0x1a0) from [<c0389cc0>] (dpm_resume_end+0x1c/0x20)
  ...

Looking at commit 7b24e798

 ("pcmcia: split up central event handler"),
the following change was made to cs.c:

                return 0;
        }
 #endif
-
-       send_event(skt, CS_EVENT_PM_RESUME, CS_EVENT_PRI_LOW);
+       if (!(skt->state & SOCKET_CARDBUS) && (skt->callback))
+               skt->callback->early_resume(skt);
        return 0;
 }

And the corresponding change in ds.c is from:

-static int ds_event(struct pcmcia_socket *skt, event_t event, int priority)
-{
-       struct pcmcia_socket *s = pcmcia_get_socket(skt);
...
-       switch (event) {
...
-       case CS_EVENT_PM_RESUME:
-               if (verify_cis_cache(skt) != 0) {
-                       dev_dbg(&skt->dev, "cis mismatch - different card\n");
-                       /* first, remove the card */
-                       ds_event(skt, CS_EVENT_CARD_REMOVAL, CS_EVENT_PRI_HIGH);
-                       mutex_lock(&s->ops_mutex);
-                       destroy_cis_cache(skt);
-                       kfree(skt->fake_cis);
-                       skt->fake_cis = NULL;
-                       s->functions = 0;
-                       mutex_unlock(&s->ops_mutex);
-                       /* now, add the new card */
-                       ds_event(skt, CS_EVENT_CARD_INSERTION,
-                                CS_EVENT_PRI_LOW);
-               }
-               break;
...
-    }

-    pcmcia_put_socket(s);

-    return 0;
-} /* ds_event */

to:

+static int pcmcia_bus_early_resume(struct pcmcia_socket *skt)
+{
+       if (!verify_cis_cache(skt)) {
+               pcmcia_put_socket(skt);
+               return 0;
+       }

+       dev_dbg(&skt->dev, "cis mismatch - different card\n");

+       /* first, remove the card */
+       pcmcia_bus_remove(skt);
+       mutex_lock(&skt->ops_mutex);
+       destroy_cis_cache(skt);
+       kfree(skt->fake_cis);
+       skt->fake_cis = NULL;
+       skt->functions = 0;
+       mutex_unlock(&skt->ops_mutex);

+       /* now, add the new card */
+       pcmcia_bus_add(skt);
+       return 0;
+}

As can be seen, the original function called pcmcia_get_socket() and
pcmcia_put_socket() around the guts, whereas the replacement code
calls pcmcia_put_socket() only in one path.  This creates an imbalance
in the refcounting.

Testing with pcmcia_put_socket() put removed shows that the bug is gone:

  dpm_suspend: c1a10998 [pcmcia_socket0] 5
  dpm_suspend_noirq: c1a10998 [pcmcia_socket0] 5
  dpm_resume_noirq: c1a10998 [pcmcia_socket0] 5
  dpm_resume: c1a10998 [pcmcia_socket0] 5
  dpm_complete: c1a10998 [pcmcia_socket0] 5

Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y
CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always false,
and so triggers some BUGs in Transparent HugePage codepaths.

asm-generic/bug.h mentions this problem, and provides a WARN_ON_SMP(x);
but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, WARN_ON_SMP_ONCE,
VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing VM_BUG_ONs.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>