Both Linus (most recent) and Steve (a while ago) reported that perf
related callbacks have massive stack bloat.

The problem is that software events need a pt_regs in order to
properly report the event location and unwind stack. And because we
could not assume one was present we allocated one on stack and filled
it with minimal bits required for operation.

Now, pt_regs is quite large, so this is undesirable. Furthermore it
turns out that most sites actually have a pt_regs pointer available,
making this even more onerous, as the stack space is pointless waste.

This patch addresses the problem by observing that software events
have well defined nesting semantics, therefore we can use static
per-cpu storage instead of on-stack.

Linus made the further observation that all but the scheduler callers
of perf_sw_event() have a pt_regs available, so we change the regular
perf_sw_event() to require a valid pt_regs (where it used to be
optional) and add perf_sw_event_sched() for the scheduler.

We have a scheduler specific call instead of a more generic _noregs()
like construct because we can assume non-recursion from the scheduler
and thereby simplify the code further (_noregs would have to put the
recursion context call inline in order to assertain which __perf_regs
element to use).

One last note on the implementation of perf_trace_buf_prepare(); we
allow .regs = NULL for those cases where we already have a pt_regs
pointer available and do not need another.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Javi Merino <javi.merino@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Vaibhav Nagarnaik <vnagarnaik@google.com>
Link: http://lkml.kernel.org/r/20141216115041.GW3337@twins.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'leds-fixes-for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds

Pull LED fix from Bryan Wu.

* 'leds-fixes-for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds:
  leds: netxbig: fix oops at probe time

Pull WRITE_ONCE argument order change from Christian Borntraeger:
 "As discussed on LKML[1] it was agreed that WRITE_ONCE(x, val) is
  better than ASSIGN_ONCE(val, x)

  Lets change that for 3.19 as 3.19 has no user yet, but the first users
  will hit linux-next soon"

[1] http://marc.info/?l=linux-kernel&m=142081181707596

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux:
  kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)

This patch fixes a NULL pointer dereference on led_dat->mode_val. Due to
this bug, a kernel oops can be observed at probe time on the LaCie 2Big
and 5Big v2 boards:

Unable to handle kernel NULL pointer dereference at virtual address 00000008
[...]
[<c03f244c>] (netxbig_led_probe) from [<c02c8c6c>] (platform_drv_probe+0x4c/0x9c)
[<c02c8c6c>] (platform_drv_probe) from [<c02c72d0>] (driver_probe_device+0x98/0x25c)
[<c02c72d0>] (driver_probe_device) from [<c02c7520>] (__driver_attach+0x8c/0x90)
[<c02c7520>] (__driver_attach) from [<c02c5c24>] (bus_for_each_dev+0x68/0x94)
[<c02c5c24>] (bus_for_each_dev) from [<c02c6408>] (bus_add_driver+0x124/0x1dc)
[<c02c6408>] (bus_add_driver) from [<c02c7ac0>] (driver_register+0x78/0xf8)
[<c02c7ac0>] (driver_register) from [<c000888c>] (do_one_initcall+0x80/0x1cc)
[<c000888c>] (do_one_initcall) from [<c0733618>] (kernel_init_freeable+0xe4/0x1b4)
[<c0733618>] (kernel_init_freeable) from [<c058db9c>] (kernel_init+0xc/0xec)
[<c058db9c>] (kernel_init) from [<c0009850>] (ret_from_fork+0x14/0x24)
[...]

This bug was introduced by commit 588a6a99
("leds: netxbig: fix attribute-creation race").
Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Cc: <stable@vger.kernel.org> # 3.17+
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

Feedback has shown that WRITE_ONCE(x, val) is easier to use than
ASSIGN_ONCE(val,x).
There are no in-tree users yet, so lets change it for 3.19.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Merge tag 'linux-kselftest-3.19-rc-5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:
 "This update contains three patches to fix one compile error, and two
  run-time bugs.  One of them fixes infinite loop on ARM"

* tag 'linux-kselftest-3.19-rc-5' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/vm: fix link error for transhuge-stress test
  tools: testing: selftests: mq_perf_tests: Fix infinite loop on ARM
  selftests/exec: allow shell return code of 126

Pull xen bug fixes from David Vrabel:
 "Several critical linear p2m fixes that prevented some hosts from
  booting"

* tag 'stable/for-linus-3.19-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: properly retrieve NMI reason
  xen: check for zero sized area when invalidating memory
  xen: use correct type for physical addresses
  xen: correct race in alloc_p2m_pmd()
  xen: correct error for building p2m list on 32 bits
  x86/xen: avoid freeing static 'name' when kasprintf() fails
  x86/xen: add extra memory for remapped frames during setup
  x86/xen: don't count how many PFNs are identity mapped
  x86/xen: Free bootmem in free_p2m_page() during early boot
  x86/xen: Remove unnecessary BUG_ON(preemptible()) in xen_setup_timer()

Pull thermal management fixes from Zhang Rui:
 "Specifics:

   - Fix a problem that Intel SoC DTS thermal driver does not work when
     CONFIG_THERMAL_INT340X is not set.

   - Fix a NULL pointer dereference when processor_thermal_device driver
     is loaded on a platform without ACPI support"

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  int340x_thermal/processor_thermal_device: return failure when
  ACPI/int340x_thermal: enumerate INT3401 for Intel SoC DTS thermal driver
  ACPI/int340x_thermal: enumerate INT340X devices even if they're not in _ART/_TRT

Using the native code here can't work properly, as the hypervisor would
normally have cleared the two reason bits by the time Dom0 gets to see
the NMI (if passed to it at all). There's a shared info field for this,
and there's an existing hook to use - just fit the two together. This
is particularly relevant so that NMIs intended to be handled by APEI /
GHES actually make it to the respective handler.

Note that the hook can (and should) be used irrespective of whether
being in Dom0, as accessing port 0x61 in a DomU would be even worse,
while the shared info field would just hold zero all the time. Note
further that hardware NMI handling for PVH doesn't currently work
anyway due to missing code in the hypervisor (but it is expected to
work the native rather than the PV way).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Pull gpio fixes from Linus Walleij:
 "Here are some GPIO fixes, mainly affecting the DLN2 IRQ handling.
  Nothing special about them, just fixes:

   - Three patches fixing IRQ handling for the DLN2
   - Null pointer handling for grgpio"

* tag 'gpio-v3.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: dln2: use bus_sync_unlock instead of scheduling work
  gpio: grgpio: Avoid potential NULL pointer dereference
  gpio: dln2: Fix gpio output value in dln2_gpio_direction_output()
  gpio: dln2: fix issue when an IRQ is unmasked then enabled

Pull MMC fixes from Ulf Hansson:
 "MMC host:
   - sdhci-pci|acpi: Support some new IDs
   - sdhci: Fix sleep from atomic context
   - sdhci-pxav3: Prevent hang during ->probe()
   - sdhci: Disable re-tuning for HS400"

* tag 'mmc-v3.19-3' of git://git.linaro.org/people/ulf.hansson/mmc:
  mmc: sdhci-pci: Add support for Intel SPT
  mmc: sdhci-acpi: Add ACPI HID INT344D
  mmc: sdhci: Fix sleep in atomic after inserting SD card
  mmc: sdhci-pxav3: do the mbus window configuration after enabling clocks
  mmc: sdhci: Disable re-tuning for HS400
  mmc: sdhci: Simplify use of tuning timer
  mmc: sdhci: Add out_unlock to sdhci_execute_tuning
  mmc: sdhci: Tuning should not change max_blk_count

Pull scsi target fixes from Nicholas Bellinger:
 "Mostly minor fixes this time, including:

   - Add missing virtio-scsi -> TCM attribute conversion in vhost-scsi.
   - Fix persistent reservations write exclusive handling to allow
     readers for all registered I_T nexuses.
   - Drop arbitrary maximum I/O size limit in order to process I/Os
     larger than 4 MB, required for initiators that don't honor block
     limits EVPD.
   - Drop the now left-over fabric_max_sectors attribute"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  iscsi-target: Fix typos in enum cmd_flags_table
  MAINTAINERS: Add entry for iSER target driver
  target: Allow Write Exclusive non-reservation holders to READ
  target: Drop left-over fabric_max_sectors attribute
  target: Drop arbitrary maximum I/O size limit
  Documentation/target: Update fabric_ops to latest code
  vhost-scsi: Add missing virtio-scsi -> TCM attribute conversion

When batching up address ranges for TLB invalidation, we check tlb->end
!= 0 to indicate that some pages have actually been unmapped.

As of commit f045bbb9 ("mmu_gather: fix over-eager
tlb_flush_mmu_free() calling"), we use the same check for freeing these
pages in order to avoid a performance regression where we call
free_pages_and_swap_cache even when no pages are actually queued up.

Unfortunately, the range could have been reset (tlb->end = 0) by
tlb_end_vma, which has been shown to cause memory leaks on arm64.
Furthermore, investigation into these leaks revealed that the fullmm
case on task exit no longer invalidates the TLB, by virtue of tlb->end
 == 0 (in 3.18, need_flush would have been set).

This patch resolves the problem by reverting commit f045bbb9, using
instead tlb->local.nr as the predicate for page freeing in
tlb_flush_mmu_free and ensuring that tlb->end is initialised to a
non-zero value in the fullmm case.
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Dave Hansen <dave@sr71.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With the introduction of the linear mapped p2m list setting memory
areas to "invalid" had to be delayed. When doing the invalidation
make sure no zero sized areas are processed.
Signed-off-by: Juegren Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

When converting a pfn to a physical address be sure to use 64 bit
wide types or convert the physical address to a pfn if possible.
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

When allocating a new pmd for the linear mapped p2m list a check is
done for not introducing another pmd when this just happened on
another cpu. In this case the old pte pointer was returned which
points to the p2m_missing or p2m_identity page. The correct value
would be the pointer to the found new page.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

In xen_rebuild_p2m_list() for large areas of invalid or identity
mapped memory the pmd entries on 32 bit systems are initialized
wrong. Correct this error.
Suggested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Add PCI IDs for SPT eMMC, SDIO and SD card.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Add ACPI HID INT344D for an Intel SDIO host controller.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Sleep in atomic context happened on Trats2 board after inserting or
removing SD card because mmc_gpio_get_cd() was called under spin lock.

Fix this by moving card detection earlier, before acquiring spin lock.
The mmc_gpio_get_cd() call does not have to be protected by spin lock
because it does not access any sdhci internal data.
The sdhci_do_get_cd() call access host flags (SDHCI_DEVICE_DEAD). After
moving it out side of spin lock it could theoretically race with driver
removal but still there is no actual protection against manual card
eject.

Dmesg after inserting SD card:
[   41.663414] BUG: sleeping function called from invalid context at drivers/gpio/gpiolib.c:1511
[   41.670469] in_atomic(): 1, irqs_disabled(): 128, pid: 30, name: kworker/u8:1
[   41.677580] INFO: lockdep is turned off.
[   41.681486] irq event stamp: 61972
[   41.684872] hardirqs last  enabled at (61971): [<c0490ee0>] _raw_spin_unlock_irq+0x24/0x5c
[   41.693118] hardirqs last disabled at (61972): [<c04907ac>] _raw_spin_lock_irq+0x18/0x54
[   41.701190] softirqs last  enabled at (61648): [<c0026fd4>] __do_softirq+0x234/0x2c8
[   41.708914] softirqs last disabled at (61631): [<c00273a0>] irq_exit+0xd0/0x114
[   41.716206] Preemption disabled at:[<  (null)>]   (null)
[   41.721500]
[   41.722985] CPU: 3 PID: 30 Comm: kworker/u8:1 Tainted: G        W      3.18.0-rc5-next-20141121 #883
[   41.732111] Workqueue: kmmcd mmc_rescan
[   41.735945] [<c0014d2c>] (unwind_backtrace) from [<c0011c80>] (show_stack+0x10/0x14)
[   41.743661] [<c0011c80>] (show_stack) from [<c0489d14>] (dump_stack+0x70/0xbc)
[   41.750867] [<c0489d14>] (dump_stack) from [<c0228b74>] (gpiod_get_raw_value_cansleep+0x18/0x30)
[   41.759628] [<c0228b74>] (gpiod_get_raw_value_cansleep) from [<c03646e8>] (mmc_gpio_get_cd+0x38/0x58)
[   41.768821] [<c03646e8>] (mmc_gpio_get_cd) from [<c036d378>] (sdhci_request+0x50/0x1a4)
[   41.776808] [<c036d378>] (sdhci_request) from [<c0357934>] (mmc_start_request+0x138/0x268)
[   41.785051] [<c0357934>] (mmc_start_request) from [<c0357cc8>] (mmc_wait_for_req+0x58/0x1a0)
[   41.793469] [<c0357cc8>] (mmc_wait_for_req) from [<c0357e68>] (mmc_wait_for_cmd+0x58/0x78)
[   41.801714] [<c0357e68>] (mmc_wait_for_cmd) from [<c0361c00>] (mmc_io_rw_direct_host+0x98/0x124)
[   41.810480] [<c0361c00>] (mmc_io_rw_direct_host) from [<c03620f8>] (sdio_reset+0x2c/0x64)
[   41.818641] [<c03620f8>] (sdio_reset) from [<c035a3d8>] (mmc_rescan+0x254/0x2e4)
[   41.826028] [<c035a3d8>] (mmc_rescan) from [<c003a0e0>] (process_one_work+0x180/0x3f4)
[   41.833920] [<c003a0e0>] (process_one_work) from [<c003a3bc>] (worker_thread+0x34/0x4b0)
[   41.841991] [<c003a3bc>] (worker_thread) from [<c003fed8>] (kthread+0xe4/0x104)
[   41.849285] [<c003fed8>] (kthread) from [<c000f268>] (ret_from_fork+0x14/0x2c)
[   42.038276] mmc0: new high speed SDHC card at address 1234
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: 94144a46 ("mmc: sdhci: add get_cd() implementation")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

In commit 5491ce3f ("mmc: sdhci-pxav3: add support for the Armada
38x SDHCI controller"), the sdhci-pxav3 driver was extended to include
support for the SDHCI controller found in the Armada 38x
processor. This mainly involved adding some MBus window related
configuration.

However, this configuration is currently done too early in ->probe():
it is done before clocks are enabled, while this configuration
involves touching the registers of the controller, which will hang the
SoC if the clock is disabled. It wasn't noticed until now because the
bootloader typically leaves gatable clocks enabled, but in situations
where we have a deferred probe (due to a CD GPIO that cannot be taken,
for example), then the probe will be re-tried later, after a clock
disable has been done in the exit path of the failed probe attempt of
the device. This second probe() will hang the system due to the clock
being disabled.

This can for example be produced on Armada 385 GP, which has a CD GPIO
connected to an I2C PCA9555. If the driver for the PCA9555 is not
compiled into the kernel, then we will have the following sequence of
events:

  1. The SDHCI probes
  2. It does the MBus configuration (which works, because the clock is
     left enabled by the bootloader)
  3. It enables the clock
  4. It tries to get the CD GPIO, which fails due to the driver being
     missing, so -EPROBE_DEFER is returned.
  5. Before returning -EPROBE_DEFER, the driver cleans up what was
     done, which includes disabling the clock.
  6. Later on, the SDHCI probe is tried again.
  7. It does the MBus configuration, which hangs because the clock is
     no longer enabled.

This commit does the obvious fix of doing the MBus configuration after
the clock has been enabled by the driver.

Fixes: 5491ce3f ("mmc: sdhci-pxav3: add support for the Armada 38x SDHCI controller")
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Re-tuning for HS400 mode must be done in HS200
mode. Currently there is no support for that.
That needs to be reflected in the code.
Specifically, if tuning is executed in HS400 mode
then return an error, and do not start the
tuning timer if HS200 tuning is being done prior
to switching to HS400.

Note that periodic re-tuning is not expected
to be needed for HS400 but re-tuning is still
needed after the host controller has lost power.
In the case of suspend/resume that is not necessary
because the card is fully re-initialised. That
just leaves runtime suspend/resume with no support
for HS400 re-tuning.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

The tuning timer is always used if the tuning mode
is 1 and there is a tuning count, irrespective of
whether this is the first call, or any subsequent
call. Consequently the logic to start the timer
can be simplified.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

A 'goto' can be used to save duplicating unlocking
and returning.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Re-tuning requires that the maximum data length
is limited to 4MiB. The code currently changes
max_blk_count in an attempt to achieve that.
This is wrong because max_blk_count is a different
limit, but it is also un-necessary because
max_req_size is 512KiB anyway. Consequently, the
changes to max_blk_count are removed and the
comment for max_req_size adjusted accordingly.
The comment is also tweaked to show that the 512KiB
limit is a SDMA limit not an ADMA limit.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Pull ARM fixes from Russell King:
 "Three small fixes from over the Christmas period, and wiring up the
  new execveat syscall for ARM"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8275/1: mm: fix PMD_SECT_RDONLY undeclared compile error
  ARM: 8253/1: mm: use phys_addr_t type in map_lowmem() for kernel mem region
  ARM: 8249/1: mm: dump: don't skip regions
  ARM: wire up execveat syscall

Pull x86 fixes from Ingo Molnar:
 "Misc fixes: two vdso fixes, two kbuild fixes and a boot failure fix
  with certain odd memory mappings"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, vdso: Use asm volatile in __getcpu
  x86/build: Clean auto-generated processor feature files
  x86: Fix mkcapflags.sh bash-ism
  x86: Fix step size adjustment during initial memory mapping
  x86_64, vdso: Fix the vdso address randomization algorithm

Pull scheduler fixes from Ingo Molnar:
 "Misc fixes: group scheduling corner case fix, two deadline scheduler
  fixes, effective_load() overflow fix, nested sleep fix, 6144 CPUs
  system fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix RCU stall upon -ENOMEM in sched_create_group()
  sched/deadline: Avoid double-accounting in case of missed deadlines
  sched/deadline: Fix migration of SCHED_DEADLINE tasks
  sched: Fix odd values in effective_load() calculations
  sched, fanotify: Deal with nested sleeps
  sched: Fix KMALLOC_MAX_SIZE overflow during cpumask allocation

Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also some kernel side fixes: uncore PMU
  driver fix, user regs sampling fix and an instruction decoder fix that
  unbreaks PEBS precise sampling"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/uncore/hsw-ep: Handle systems with only two SBOXes
  perf/x86_64: Improve user regs sampling
  perf: Move task_pt_regs sampling into arch code
  x86: Fix off-by-one in instruction decoder
  perf hists browser: Fix segfault when showing callchain
  perf callchain: Free callchains when hist entries are deleted
  perf hists: Fix children sort key behavior
  perf diff: Fix to sort by baseline field by default
  perf list: Fix --raw-dump option
  perf probe: Fix crash in dwarf_getcfi_elf
  perf probe: Fix to fall back to find probe point in symbols
  perf callchain: Append callchains only when requested
  perf ui/tui: Print backtrace symbols when segfault occurs
  perf report: Show progress bar for output resorting

Pull locking fixes from Ingo Molnar:
 "A liblockdep fix and a mutex_unlock() mutex-debugging fix"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mutex: Always clear owner field upon mutex_unlock()
  tools/liblockdep: Fix debug_check thinko in mutex destroy

Fix for BUG_ON(anon_vma->degree) splashes in unlink_anon_vmas() ("kernel
BUG at mm/rmap.c:399!") caused by commit 7a3ef208 ("mm: prevent
endless growth of anon_vma hierarchy")

Anon_vma_clone() is usually called for a copy of source vma in
destination argument.  If source vma has anon_vma it should be already
in dst->anon_vma.  NULL in dst->anon_vma is used as a sign that it's
called from anon_vma_fork().  In this case anon_vma_clone() finds
anon_vma for reusing.

Vma_adjust() calls it differently and this breaks anon_vma reusing
logic: anon_vma_clone() links vma to old anon_vma and updates degree
counters but vma_adjust() overrides vma->anon_vma right after that.  As
a result final unlink_anon_vmas() decrements degree for wrong anon_vma.

This patch assigns ->anon_vma before calling anon_vma_clone().
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Reported-and-tested-by: Chris Clayton <chris2553@googlemail.com>
Reported-and-tested-by: Oded Gabbay <oded.gabbay@amd.com>
Reported-and-tested-by: Chih-Wei Huang <cwhuang@android-x86.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Daniel Forrest <dan.forrest@ssec.wisc.edu>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: stable@vger.kernel.org  # to match back-porting of 7a3ef208Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit fee7e49d ("mm: propagate error from stack expansion even for
guard page") made sure that we return the error properly for stack
growth conditions.  It also theorized that counting the guard page
towards the stack limit might break something, but also said "Let's see
if anybody notices".

Somebody did notice.  Apparently android-x86 sets the stack limit very
close to the limit indeed, and including the guard page in the rlimit
check causes the android 'zygote' process problems.

So this adds the (fairly trivial) code to make the stack rlimit check be
against the actual real stack size, rather than the size of the vma that
includes the guard page.
Reported-and-tested-by: Chih-Wei Huang <cwhuang@android-x86.org>
Cc: Jay Foad <jay.foad@gmail.com>
Cc: stable@kernel.org  # to match back-porting of fee7e49dSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull VFIO fix from Alex Williamson:
 "Fix PCI header check in vfio_pci_probe() (Wei Yang)"

* tag 'vfio-v3.19-rc4' of git://github.com/awilliam/linux-vfio:
  vfio-pci: Fix the check on pci device type in vfio_pci_probe()

Pull SCSI fix from James Bottomley:
 "Just one fix: a qlogic busy wait regression"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  qla2xxx: fix busy wait regression

Pull sound fixes from Takashi Iwai:
 "All a few small regression or stable fixes: a Nvidia HDMI ID addition,
  a regression fix for CAIAQ stream count, a typo fix for GPIO setup
  with STAC/IDT HD-audio codecs, and a Fireworks big-endian fix"

* tag 'sound-3.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: fireworks: fix an endianness bug for transaction length
  ALSA: hda - Add new GPU codec ID 0x10de0072 to snd-hda
  ALSA: hda - Fix wrong gpio_dir & gpio_mask hint setups for IDT/STAC codecs
  ALSA: snd-usb-caiaq: fix stream count check

Pull HID updates from Jiri Kosina:

 - bounds checking fixes in logitech and roccat drivers, from Peter Wu
   and Dan Carpenter

 - double-kfree fix in i2c-hid driver on bus shutdown, from Mika
   Westerberg

 - a couple of various small driver fixes

 - a few device id additions

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: roccat: potential out of bounds in pyra_sysfs_write_settings()
  HID: Add a new id 0x501a for Genius MousePen i608X
  HID: logitech-hidpp: prefix the name with "Logitech"
  HID: logitech-hidpp: avoid unintended fall-through
  HID: Allow HID_BATTERY_STRENGTH to be enabled
  HID: i2c-hid: Do not free buffers in i2c_hid_stop()
  HID: add battery quirk for USB_DEVICE_ID_APPLE_ALU_WIRELESS_2011_ISO keyboard
  HID: logitech-hidpp: check WTP report length
  HID: logitech-dj: check report length

Pull drm fixes from Dave Airlie:
 "I'm briefly working between holidays and LCA, so this is close to a
  couple of weeks of fixes,

  Two sets of amdkfd fixes, this is a new feature this kernel, and this
  pull fixes a few issues since it got merged, ordering when built-in to
  kernel and also the iommu vs gpu ordering patch, it also reworks the
  ioctl before the initial release.

  Otherwise:
   - radeon: some misc fixes all over, hdmi, 4k, dpm
   - nouveau: mcp77 init fixes, oops fix, bug on fix, msi fix
   - i915: power fixes, revert VGACNTR patch

  Probably be quiteer next week since I'll be at LCA anyways"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (33 commits)
  drm/amdkfd: rewrite kfd_ioctl() according to drm_ioctl()
  drm/amdkfd: reformat IOCTL definitions to drm-style
  drm/amdkfd: Do copy_to/from_user in general kfd_ioctl()
  drm/radeon: integer underflow in radeon_cp_dispatch_texture()
  drm/radeon: adjust default bapm settings for KV
  drm/radeon: properly filter DP1.2 4k modes on non-DP1.2 hw
  drm/radeon: fix sad_count check for dce3
  drm/radeon: KV has three PPLLs (v2)
  drm/amdkfd: unmap VMID<-->PASID when relesing VMID (non-HWS)
  drm/radeon: Init amdkfd only if it was compiled
  amdkfd: actually allocate longs for the pasid bitmask
  drm/nouveau/nouveau: Do not BUG_ON(!spin_is_locked()) on UP
  drm/nv4c/mc: disable msi
  drm/nouveau/fb/ram/mcp77: enable NISO poller
  drm/nouveau/fb/ram/mcp77: use carveout reg to determine size
  drm/nouveau/fb/ram/mcp77: subclass nouveau_ram
  drm/nouveau: wake up the card if necessary during gem callbacks
  drm/nouveau/device: Add support for GK208B, resolves bug 86935
  drm/nouveau: fix missing return statement in nouveau_ttm_tt_unpopulate
  drm/nouveau/bios: fix oops on pre-nv50 chipsets
  ...

Pull arm64 fixes from Will Deacon:
 "Here is a handful of minor arm64 fixes discovered and fixed over the
  Christmas break.  The main part is adding some missing #includes that
  we seem to be getting transitively but have started causing problems
  in -next.

   - Fix early mapping fixmap corruption by EFI runtime services
   - Fix __NR_compat_syscalls off-by-one
   - Add missing sanity checks for some 32-bit registers
   - Add some missing #includes which we get transitively
   - Remove unused prepare_to_copy() macro"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/efi: add missing call to early_ioremap_reset()
  arm64: fix missing asm/io.h include in kernel/smp_spin_table.c
  arm64: fix missing asm/alternative.h include in kernel/module.c
  arm64: fix missing linux/bug.h include in asm/arch_timer.h
  arm64: fix missing asm/pgtable-hwdef.h include in asm/processor.h
  arm64: sanity checks: add missing AArch32 registers
  arm64: Remove unused prepare_to_copy()
  arm64: Correct __NR_compat_syscalls for bpf