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>

In xen_restore_fl_direct(), xen_force_evtchn_callback() was being
called even if no events were pending.  This resulted in (depending on
workload) about a 100 times as many xen_version hypercalls as
necessary.

Fix this by correcting the sense of the conditional jump.

This seems to give a significant performance benefit for some
workloads.

There is some subtle tricksy "..since the check here is trying to
check both pending and masked in a single cmpw, but I think this is
correct. It will call check_events now only when the combined
mask+pending word is 0x0001 (aka unmasked, pending)." (Ian)

CC: stable@kernel.org
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

We did a similar check for the P-states but did not do it for
the C-states. What we want to do is ignore cases where the DSDT
has definition for sixteen CPUs, but the machine only has eight
CPUs and we get:
xen-acpi-processor: (CX): Hypervisor error (-22) for ACPI CPU14

Reported-by: Tobias Geiger <tobias.geiger@vido.info>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When we boot on a machine that can hotplug CPUs and we
are using 'dom0_max_vcpus=X' on the Xen hypervisor line
to clip the amount of CPUs available to the initial domain,
we get this:

(XEN) Command line: com1=115200,8n1 dom0_mem=8G noreboot dom0_max_vcpus=8 sync_console mce_verbosity=verbose console=com1,vga loglvl=all guest_loglvl=all
.. snip..
DMI: Intel Corporation S2600CP/S2600CP, BIOS SE5C600.86B.99.99.x032.072520111118 07/25/2011
.. snip.
SMP: Allowing 64 CPUs, 32 hotplug CPUs
installing Xen timer for CPU 7
cpu 7 spinlock event irq 361
NMI watchdog: disabled (cpu7): hardware events not enabled
Brought up 8 CPUs
.. snip..
	[acpi processor finds the CPUs are not initialized and starts calling
	arch_register_cpu, which creates /sys/devices/system/cpu/cpu8/online]
CPU 8 got hotplugged
CPU 9 got hotplugged
CPU 10 got hotplugged
.. snip..
initcall 1_acpi_battery_init_async+0x0/0x1b returned 0 after 406 usecs
calling  erst_init+0x0/0x2bb @ 1

	[and the scheduler sticks newly started tasks on the new CPUs, but
	said CPUs cannot be initialized b/c the hypervisor has limited the
	amount of vCPUS to 8 - as per the dom0_max_vcpus=8 flag.
	The spinlock tries to kick the other CPU, but the structure for that
	is not initialized and we crash.]
BUG: unable to handle kernel paging request at fffffffffffffed8
IP: [<ffffffff81035289>] xen_spin_lock+0x29/0x60
PGD 180d067 PUD 180e067 PMD 0
Oops: 0002 [#1] SMP
CPU 7
Modules linked in:

Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc2upstream-00001-gf5154e8 #1 Intel Corporation S2600CP/S2600CP
RIP: e030:[<ffffffff81035289>]  [<ffffffff81035289>] xen_spin_lock+0x29/0x60
RSP: e02b:ffff8801fb9b3a70  EFLAGS: 00010282

With this patch, we cap the amount of vCPUS that the initial domain
can run, to exactly what dom0_max_vcpus=X has specified.

In the future, if there is a hypercall that will allow a running
domain to expand past its initial set of vCPUS, this patch should
be re-evaluated.

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

In pirq_check_eoi_map use the pirq number rather than the Linux irq
number to check whether an eoi is needed in the pirq_eoi_map.

The reason is that the irq number is not always identical to the
pirq number so if we wrongly use the irq number to check the
pirq_eoi_map we are going to check for the wrong pirq to EOI.

As a consequence some interrupts might not be EOI'ed by the
guest correctly.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Tobias Geiger <tobias.geiger@vido.info>
[v1: Added some extra wording to git commit]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

There are exactly four users of __monitor and __mwait:

 - cstate.c (which allows acpi_processor_ffh_cstate_enter to be called
   when the cpuidle API drivers are used. However patch
   "cpuidle: replace xen access to x86 pm_idle and default_idle"
   provides a mechanism to disable the cpuidle and use safe_halt.
 - smpboot (which allows mwait_play_dead to be called). However
   safe_halt is always used so we skip that.
 - intel_idle (same deal as above).
 - acpi_pad.c. This the one that we do not want to run as we
   will hit the below crash.

Why do we want to expose MWAIT_LEAF in the first place?
We want it for the xen-acpi-processor driver - which uploads
C-states to the hypervisor. If MWAIT_LEAF is set, the cstate.c
sets the proper address in the C-states so that the hypervisor
can benefit from using the MWAIT functionality. And that is
the sole reason for using it.

Without this patch, if a module performs mwait or monitor we
get this:

invalid opcode: 0000 [#1] SMP
CPU 2
.. snip..
Pid: 5036, comm: insmod Tainted: G           O 3.4.0-rc2upstream-dirty #2 Intel Corporation S2600CP/S2600CP
RIP: e030:[<ffffffffa000a017>]  [<ffffffffa000a017>] mwait_check_init+0x17/0x1000 [mwait_check]
RSP: e02b:ffff8801c298bf18  EFLAGS: 00010282
RAX: ffff8801c298a010 RBX: ffffffffa03b2000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8801c29800d8 RDI: ffff8801ff097200
RBP: ffff8801c298bf18 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: ffffffffa000a000 R14: 0000005148db7294 R15: 0000000000000003
FS:  00007fbb364f2700(0000) GS:ffff8801ff08c000(0000) knlGS:0000000000000000
CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 000000000179f038 CR3: 00000001c9469000 CR4: 0000000000002660
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process insmod (pid: 5036, threadinfo ffff8801c298a000, task ffff8801c29cd7e0)
Stack:
 ffff8801c298bf48 ffffffff81002124 ffffffffa03b2000 00000000000081fd
 000000000178f010 000000000178f030 ffff8801c298bf78 ffffffff810c41e6
 00007fff3fb30db9 00007fff3fb30db9 00000000000081fd 0000000000010000
Call Trace:
 [<ffffffff81002124>] do_one_initcall+0x124/0x170
 [<ffffffff810c41e6>] sys_init_module+0xc6/0x220
 [<ffffffff815b15b9>] system_call_fastpath+0x16/0x1b
Code: <0f> 01 c8 31 c0 0f 01 c9 c9 c3 00 00 00 00 00 00 00 00 00 00 00 00
RIP  [<ffffffffa000a017>] mwait_check_init+0x17/0x1000 [mwait_check]
 RSP <ffff8801c298bf18>
---[ end trace 16582fc8a3d1e29a ]---
Kernel panic - not syncing: Fatal exception

With this module (which is what acpi_pad.c would hit):

MODULE_AUTHOR("Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>");
MODULE_DESCRIPTION("mwait_check_and_back");
MODULE_LICENSE("GPL");
MODULE_VERSION();

static int __init mwait_check_init(void)
{
	__monitor((void *)&current_thread_info()->flags, 0, 0);
	__mwait(0, 0);
	return 0;
}
static void __exit mwait_check_exit(void)
{
}
module_init(mwait_check_init);
module_exit(mwait_check_exit);

Reported-by: Liu, Jinsong <jinsong.liu@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This reverts commit b960d6c4

.

If we have another thread (very likely) touched the list, we
end up hitting a problem "that the next element is wrong because
we should be able to cope with that. The problem is that the
next->next pointer would be set LIST_POISON1. " (Stefano's
comment on the patch).

Reverting for now.

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

linux/drivers/xen/manage.c: In function 'do_suspend':
linux/drivers/xen/manage.c:160:5: warning: 'si.cancelled' may be used uninitialized in this function

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

A rather annoying and common case is when booting a PVonHVM guest
and exposing the PV KBD and PV VFB - as broken toolstacks don't
always initialize the backends correctly.

Normally The HVM guest is using the VGA driver and the emulated
keyboard for this (though upstream version of QEMU implements
PV KBD, but still uses a VGA driver). We provide a very basic
two-stage wait mechanism - where we wait for 30 seconds for all
devices, and then for 270 for all them except the two mentioned.

That allows us to wait for the essential devices, like network
or disk for the full 6 minutes.

To trigger this, put this in your guest config:

vfb = [ 'vnc=1, vnclisten=0.0.0.0 ,vncunused=1']

instead of this:
vnc=1
vnclisten="0.0.0.0"

CC: stable@kernel.org
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
[v3: Split delay in non-essential (30 seconds) and essential
 devices per Ian and Stefano suggestion]
[v4: Added comments per Stefano suggestion]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/block/xen-blkback/xenbus.c: In function 'xen_blkbk_discard':
drivers/block/xen-blkback/xenbus.c:419:4: warning: passing argument 1 of 'dev_warn' makes pointer from integer without a cast
+[enabled by default]
include/linux/device.h:894:5: note: expected 'const struct device *' but argument is of type 'long int'

It is unclear how that mistake made it in. It surely is wrong.

Acked-by: Jens Axboe <axboe@kernel.dk>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

* commit 'c104f1fa': (14566 commits)
  cpufreq: OMAP: fix build errors: depends on ARCH_OMAP2PLUS
  sparc64: Eliminate obsolete __handle_softirq() function
  sparc64: Fix bootup crash on sun4v.
  kconfig: delete last traces of __enabled_ from autoconf.h
  Revert "kconfig: fix __enabled_ macros definition for invisible and un-selected symbols"
  kconfig: fix IS_ENABLED to not require all options to be defined
  irq_domain: fix type mismatch in debugfs output format
  staging: android: fix mem leaks in __persistent_ram_init()
  staging: vt6656: Don't leak memory in drivers/staging/vt6656/ioctl.c::private_ioctl()
  staging: iio: hmc5843: Fix crash in probe function.
  panic: fix stack dump print on direct call to panic()
  drivers/rtc/rtc-pl031.c: enable clock on all ST variants
  Revert "mm: vmscan: fix misused nr_reclaimed in shrink_mem_cgroup_zone()"
  hugetlb: fix race condition in hugetlb_fault()
  drivers/rtc/rtc-twl.c: use static register while reading time
  drivers/rtc/rtc-s3c.c: add placeholder for driver private data
  drivers/rtc/rtc-s3c.c: fix compilation error
  MAINTAINERS: add PCDP console maintainer
  memcg: do not open code accesses to res_counter members
  drivers/rtc/rtc-efi.c: fix section mismatch warning
  ...

Use list_for_each_entry_safe and remove the spin_lock acquisition in
m2p_find_override.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Since we are using the m2p_override we do have struct pages
corresponding to the user vma mmap'ed by gntdev.

Removing the VM_PFNMAP flag makes get_user_pages work on that vma.
An example test case would be using a Xen userspace block backend
(QDISK) on a file on NFS using O_DIRECT.

CC: stable@kernel.org
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Jump to the label ini_nomem as done on the failure of the page allocations
above.

The code at ini_nomem is modified to accommodate different return values.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Pull block driver bits from Jens Axboe:

 - A series of fixes for mtip32xx.  Most from Asai at Micron, but also
   one from Greg, getting rid of the dependency on PCIE_HOTPLUG.

 - A few bug fixes for xen-blkfront, and blkback.

 - A virtio-blk fix for Vivek, making resize actually work.

 - Two fixes from Stephen, making larger transfers possible on cciss.
   This is needed for tape drive support.

* 'for-3.4/drivers' of git://git.kernel.dk/linux-block:
  block: mtip32xx: remove HOTPLUG_PCI_PCIE dependancy
  mtip32xx: dump tagmap on failure
  mtip32xx: fix handling of commands in various scenarios
  mtip32xx: Shorten macro names
  mtip32xx: misc changes
  mtip32xx: Add new sysfs entry 'status'
  mtip32xx: make setting comp_time as common
  mtip32xx: Add new bitwise flag 'dd_flag'
  mtip32xx: fix error handling in mtip_init()
  virtio-blk: Call revalidate_disk() upon online disk resize
  xen/blkback: Make optional features be really optional.
  xen/blkback: Squash the discard support for 'file' and 'phy' type.
  mtip32xx: fix incorrect value set for drv_cleanup_done, and re-initialize and start port in mtip_restart_port()
  cciss: Fix scsi tape io with more than 255 scatter gather elements
  cciss: Initialize scsi host max_sectors for tape drive support
  xen-blkfront: make blkif_io_lock spinlock per-device
  xen/blkfront: don't put bdev right after getting it
  xen-blkfront: use bitmap_set() and bitmap_clear()
  xen/blkback: Enable blkback on HVM guests
  xen/blkback: use grant-table.c hypercall wrappers

Pull block core bits from Jens Axboe:
 "It's a nice and quiet round this time, since most of the tricky stuff
  has been pushed to 3.5 to give it more time to mature.  After a few
  hectic block IO core changes for 3.3 and 3.2, I'm quite happy with a
  slow round.

  Really minor stuff in here, the only real functional change is making
  the auto-unplug threshold a per-queue entity.  The threshold is set so
  that it's low enough that we don't hold off IO for too long, but still
  big enough to get a nice benefit from the batched insert (and hence
  queue lock cost reduction).  For raid configurations, this currently
  breaks down."

* 'for-3.4/core' of git://git.kernel.dk/linux-block:
  block: make auto block plug flush threshold per-disk based
  Documentation: Add sysfs ABI change for cfq's target latency.
  block: Make cfq_target_latency tunable through sysfs.
  block: use lockdep_assert_held for queue locking
  block: blk_alloc_queue_node(): use caller's GFP flags instead of GFP_KERNEL

The OMAP driver needs a 'depends on ARCH_OMAP2PLUS' since it only
builds for OMAP2+ platforms.

This 'depends on' was in the original patch from Russell King, but was
erroneously removed by me when making this option user-selectable in
commit b09db45c

 (cpufreq: OMAP driver depends CPUfreq tables.)  This
patch remedies that.

Apologies to Russell King for breaking his originally working patch.

Also, thanks to Grazvydas Ignotas for reporting the same problem.

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull sparc fixes from David Miller.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Eliminate obsolete __handle_softirq() function
  sparc64: Fix bootup crash on sun4v.

Pull hwmon patches from Guenter Roeck:
 "Fix build warnings in four drivers"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (pmbus_core) Fix compiler warning
  hwmon: (smsc47m1) Fix compiler warning
  hwmon: (acpi_power_meter) Fix compiler warning seen in some configurations
  hwmon: (smsc47b397) Fix compiler warning

Pull GPIO bug fixes from Grant Likely:
 "Miscellaneous bug fixes to GPIO drivers and for a corner case in the
  gpio device tree parsing code."

* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  gpio/exynos: Fix compiler warning in gpio-samsung.c file
  gpio: Fix range check in of_gpio_simple_xlate()
  gpio: Fix uninitialized variable bit in adp5588_irq_handler
  gpio/sodaville: Convert sodaville driver to new irqdomain API

Pull SPI bug fixes from Grant Likely:
 "Miscellaneous driver bug fixes.  No major changes in this branch."

* tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  spi/imx: prevent NULL pointer dereference in spi_imx_probe()
  spi/imx: mark base member in spi_imx_data as __iomem
  spi/mpc83xx: fix NULL pdata dereference bug
  spi/davinci: Fix DMA API usage in davinci
  spi/pL022: include types.h to remove compilation warnings

The invocation of softirq is now handled by irq_exit(), so there is no
need for sparc64 to invoke it on the trap-return path.  In fact, doing so
is a bug because if the trap occurred in the idle loop, this invocation
can result in lockdep-RCU failures.  The problem is that RCU ignores idle
CPUs, and the sparc64 trap-return path to the softirq handlers fails to
tell RCU that the CPU must be considered non-idle while those handlers
are executing.  This means that RCU is ignoring any RCU read-side critical
sections in those handlers, which in turn means that RCU-protected data
can be yanked out from under those read-side critical sections.

The shiny new lockdep-RCU ability to detect RCU read-side critical sections
that RCU is ignoring located this problem.

The fix is straightforward: Make sparc64 stop manually invoking the
softirq handlers.

Reported-by: Meelis Roos <mroos@linux.ee>
Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Meelis Roos <mroos@linux.ee>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

The DS driver registers as a subsys_initcall() but this can be too
early, in particular this risks registering before we've had a chance
to allocate and setup module_kset in kernel/params.c which is
performed also as a subsyts_initcall().

Register DS using device_initcall() insteal.

Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: stable@vger.kernel.org

Pull infiniband fix from Roland Dreier:
 "Add a fix for a bug hit by Alexey Shvetsov in ib_srtp that hits on
  non-mlx4 hardware."

* tag 'srpt-srq-type' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB/srpt: Set srq_type to IB_SRQT_BASIC

We've now fixed IS_ENABLED() and friends to not require any special
"__enabled_" prefixed versions of the normal Kconfig options, so delete
the last traces of them being generated.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This reverts commit 953742c8

.

Dumping two lines into autoconf.h for all existing Kconfig options
results in a giant file (~16k lines) we have to process each time we
compile something.  We've weaned IS_ENABLED() and similar off of
requiring the __enabled_ definitions so now we can revert the change
which caused all the extra lines.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Using IS_ENABLED() within C (vs.  within CPP #if statements) in its
current form requires us to actually define every possible bool/tristate
Kconfig option twice (__enabled_* and __enabled_*_MODULE variants).

This results in a huge autoconf.h file, on the order of 16k lines for a
x86_64 defconfig.

Fixing IS_ENABLED to be able to work on the smaller subset of just
things that we really have defined is step one to fixing this.  Which
means it has to not choke when fed non-enabled options, such as:

  include/linux/netdevice.h:964:1: warning: "__enabled_CONFIG_FCOE_MODULE" is not defined [-Wundef]

The original prototype of how to implement a C and preprocessor
compatible way of doing this came from the Google+ user "comex ." in
response to Linus' crowdsourcing challenge for a possible improvement on
his earlier C specific solution:

	#define config_enabled(x)       (__stringify(x)[0] == '1')

In this implementation, I've chosen variable names that hopefully make
how it works more understandable.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull USB fixes from Greg KH:
 "Here are a number of fixes for the USB core and drivers for 3.4-rc2

  Lots of tiny xhci fixes here, a few usb-serial driver fixes and new
  device ids, and a smattering of other minor fixes in different USB
  drivers.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org&gt;">

* tag 'usb-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (30 commits)
  USB: update usbtmc api documentation
  xHCI: Correct the #define XHCI_LEGACY_DISABLE_SMI
  xHCI: use gfp flags from caller instead of GFP_ATOMIC
  xHCI: add XHCI_RESET_ON_RESUME quirk for VIA xHCI host
  USB: fix bug of device descriptor got from superspeed device
  xhci: Fix register save/restore order.
  xhci: Restore event ring dequeue pointer on resume.
  xhci: Don't write zeroed pointers to xHC registers.
  xhci: Warn when hosts don't halt.
  xhci: don't re-enable IE constantly
  usb: xhci: fix section mismatch in linux-next
  xHCI: correct to print the true HSEE of USBCMD
  USB: serial: fix race between probe and open
  UHCI: hub_status_data should indicate if ports are resuming
  EHCI: keep track of ports being resumed and indicate in hub_status_data
  USB: fix race between root-hub suspend and remote wakeup
  USB: sierra: add support for Sierra Wireless MC7710
  USB: ftdi_sio: fix race condition in TIOCMIWAIT, and abort of TIOCMIWAIT when the device is removed
  USB: ftdi_sio: fix status line change handling for TIOCMIWAIT and TIOCGICOUNT
  USB: don't ignore suspend errors for root hubs
  ...

Pull tty and serial fixes from Greg KH:
 "Here are some tty and serial fixes for 3.4-rc2.

  Most important here is the pl011 fix, which has been reported by about
  100 different people, which means more people use it than I expected
  :)

  There are also some 8250 driver reverts due to some problems reported
  by them.  And other minor fixes as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org&gt;">

* tag 'tty-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  pch_uart: Add Kontron COMe-mTT10 uart clock quirk
  pch_uart: Fix MSI setting issue
  serial/8250_pci: add a "force background timer" flag and use it for the "kt" serial port
  Revert "serial/8250_pci: setup-quirk workaround for the kt serial controller"
  Revert "serial/8250_pci: init-quirk msi support for kt serial controller"
  tty/serial/omap: console can only be built-in
  serial: samsung: fix omission initialize ulcon in reset port fn()
  printk(): add KERN_CONT where needed in hpet and vt code
  tty/serial: atmel_serial: fix RS485 half-duplex problem
  tty: serial: altera_uart: Check for NULL platform_data in probe.
  isdn/gigaset: use gig_dbg() for debugging output
  omap-serial: Fix the error handling in the omap_serial probe
  serial: PL011: move interrupt clearing

Pull staging tree fixes from Greg KH:
 "Here are a number of bugfixes for the drivers/staging/ portion of the
  kernel that have been reported recently.

  Nothing major here, with maybe the exception of the ramster code can
  now be built so it is enabled in the build again, and lots of memory
  leaks that people like to have fixed on their systems.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org&gt;">

* tag 'staging-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: android: fix mem leaks in __persistent_ram_init()
  staging: vt6656: Don't leak memory in drivers/staging/vt6656/ioctl.c::private_ioctl()
  staging: iio: hmc5843: Fix crash in probe function.
  staging/xgifb: fix display on XGI Volari Z11m cards
  Staging: android: timed_gpio: Fix resource leak in timed_gpio_probe error paths
  android: make persistent_ram based drivers depend on HAVE_MEMBLOCK
  staging: iio: ak8975: Remove i2c client data corruption
  staging: drm/omap: move where DMM driver is registered
  staging: zsmalloc: fix memory leak
  Staging: rts_pstor: off by one in for loop
  staging: ozwpan: Added new maintainer for ozwpan
  staging:rts_pstor:Avoid "Bad target number" message when probing driver
  staging:rts_pstor:Fix possible panic by NULL pointer dereference
  Staging: vt6655-6: check keysize before memcpy()
  staging/media/as102: Don't call release_firmware() on uninitialized variable
  staging:iio:core add missing increment of loop index in iio_map_array_unregister()
  staging: ramster: unbreak my heart
  staging/vme: Fix module parameters
  staging: sep: Fix sign of error

Pull driver core and kobject fixes from Greg KH:
 "Here are some minor fixes for the driver core and kobjects that people
  have reported recently.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org&gt;">

* tag 'driver-core-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  kobject: provide more diagnostic info for kobject_add_internal() failures
  sysfs: handle 'parent deleted before child added'
  sysfs: Prevent crash on unset sysfs group attributes
  sysfs: Update the name hash for an entry after changing the namespace
  drivers/base: fix compiler warning in SoC export driver - idr should be ida
  drivers/base: Remove unneeded spin_lock_init call for soc_lock

Pull a fix for the recent irqdomain bug fixes from Grant Likely:
 "I flubbed one patch in the last pull request which broke a format
  string on 64 bit platforms.  Here's the fix."

* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  irq_domain: fix type mismatch in debugfs output format

sizeof(void*) returns an unsigned long, but it was being used as a width parameter to a "%-*s" format string which requires an int.  On 64 bit platforms this causes a type mismatch:

    linux/kernel/irq/irqdomain.c:575: warning: field width should have type
    'int', but argument 6 has type 'long unsigned int'

This change casts the size to an int so printf gets the right data type.

Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: David Daney <david.daney@cavium.com>

Pull trivial perf build failure fix from Thomas Gleixner.

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools: Fix getrusage() related build failure on glibc trunk

Pull timer fixes from Thomas Gleixner:
 "The itimer removal one is not strictly a fix, but I really wanted to
  avoid a rebase of the urgent ones."

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "clocksource: Load the ACPI PM clocksource asynchronously"
  clockevents: tTack broadcast device mode change in tick_broadcast_switch_to_oneshot()
  itimer: Use printk_once instead of WARN_ONCE
  nohz: Fix stale jiffies update in tick_nohz_restart()
  tick: Document TICK_ONESHOT config option
  proc: stats: Use arch_idle_time for idle and iowait times if available
  itimer: Schedule silent NULL pointer fixup in setitimer() for removal

Pull x86 fixes from Thomas Gleixner.

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Use correct byte-sized register constraint in __add()
  x86: Use correct byte-sized register constraint in __xchg_op()
  x86: vsyscall: Use NULL instead 0 for a pointer argument

If, in __persistent_ram_init(), the call to
persistent_ram_buffer_init() fails or the call to
persistent_ram_init_ecc() fails then we fail to free the memory we
allocated to 'prz' with kzalloc() - thus leaking it.

To prevent the leaks I consolidated all error exits from the function
at a 'err:' label at the end and made all error cases jump to that
label where we can then make sure we always free 'prz'. This is safe
since all the situations where the code bails out happen before 'prz'
has been stored anywhere and although we'll do a redundant kfree(NULL)
call in the case of kzalloc() itself failing that's OK since kfree()
deals gracefully with NULL pointers and I felt it was more important
to keep all error exits at a single location than to avoid that one
harmless/redundant kfree() on a error path.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Colin Cross <ccross@android.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>