Memory blocks can be onlined in random order. When this order is not natural
some memory pages are not onlined because of the redundant check in
hv_online_page().

Here is a real world scenario:
1) Host tries to hot-add the following (process_hot_add):
  pg_start=rg_start=0x48000, pfn_cnt=111616, rg_size=262144

2) This results in adding 4 memory blocks:
[  109.057866] init_memory_mapping: [mem 0x48000000-0x4fffffff]
[  114.102698] init_memory_mapping: [mem 0x50000000-0x57ffffff]
[  119.168039] init_memory_mapping: [mem 0x58000000-0x5fffffff]
[  124.233053] init_memory_mapping: [mem 0x60000000-0x67ffffff]
The last one is incomplete but we have special has->covered_end_pfn counter to
avoid onlining non-backed frames and hv_bring_pgs_online() function to bring
them online later on.

3) Now we have 4 offline memory blocks: /sys/devices/system/memory/memory9-12
$ for f in /sys/devices/system/memory/memory*/state; do echo $f `cat $f`; done | grep -v onlin
/sys/devices/system/memory/memory10/state offline
/sys/devices/system/memory/memory11/state offline
/sys/devices/system/memory/memory12/state offline
/sys/devices/system/memory/memory9/state offline

4) We bring them online in non-natural order:
$grep MemTotal /proc/meminfo
MemTotal:         966348 kB
$echo online > /sys/devices/system/memory/memory12/state && grep MemTotal /proc/meminfo
MemTotal:        1019596 kB
$echo online > /sys/devices/system/memory/memory11/state && grep MemTotal /proc/meminfo
MemTotal:        1150668 kB
$echo online > /sys/devices/system/memory/memory9/state && grep MemTotal /proc/meminfo
MemTotal:        1150668 kB

As you can see memory9 block gives us zero additional memory. We can also
observe a huge discrepancy between host- and guest-reported memory sizes.

The root cause of the issue is the redundant pg >= covered_start_pfn check (and
covered_start_pfn advancing) in hv_online_page(). When upper memory block in
being onlined before the lower one (memory12 and memory11 in the above case) we
advance the covered_start_pfn pointer and all memory9 pages do not pass the
check. If the assumption that host always gives us requests in sequential order
and pg_start always equals rg_start when the first request for the new HA
region is received (that's the case in my testing) is correct than we can get
rid of covered_start_pfn and pg >= start_pfn check in hv_online_page() is
sufficient.

The current char-next branch is broken and this patch fixes
the bug.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When add_memory() fails the following BUG is observed:
[  743.646107] hv_balloon: hot_add memory failed error is -17
[  743.679973]
[  743.680930] =====================================
[  743.680930] [ BUG: bad unlock balance detected! ]
[  743.680930] 3.19.0-rc5_bug1131426+ #552 Not tainted
[  743.680930] -------------------------------------
[  743.680930] kworker/0:2/255 is trying to release lock (&dm_device.ha_region_mutex) at:
[  743.680930] [<ffffffff81aae5fe>] mutex_unlock+0xe/0x10
[  743.680930] but there are no more locks to release!

This happens as we don't acquire ha_region_mutex and hot_add_req() expects us
to as it does unconditional mutex_unlock(). Acquire the lock on the error path.

The current char-next branch is broken and this patch fixes
the bug.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch is a continuation of the rescind handling cleanup work. We cannot
block in the global message handling work context especially if we are blocking
waiting for the host to wake us up. I would like to thank
Dexuan Cui <decui@microsoft.com> for observing this problem.

The current char-next branch is broken and this patch fixes
the bug.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the new group field of struct miscdevice for managing the sysfs
entries instead of manually adding/removing via device_create_file()
and device_remove_file().  This simplifies the code a lot and fixes
the possible races.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add groups field to struct miscdevice for passing the attribute groups
at device creation.  In this way, the driver can avoid the manual call
of device_create_file() after the device registration, which is
basically a racy operation, in addition to the reduction of manual
device_remove_file() calls.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

return type of wait_for_completion_timeout is unsigned long not int. The
rc variable is renamed timeout to reflect its use and the type adjusted to
unsigned long.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

return type of wait_for_completion_timeout is unsigned long not int. The
rc variable is renamed timeout to reflect its use and the type adjusted to
unsigned long.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

return type of wait_for_completion_timeout is unsigned long not int. The
rc variable is in use for other calls so an additional timeout variable
of type unsigned long is added.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

an open syscall now assignes file->private_data to a pointer to the
miscdevice structure. This reminds people not to duplicate code if
they want this and not to depend on it being NULL.
Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In mei_host_client_init function we enable the all internal
connected clients including NFC. This is done before we set the device
to enabled state and let userspace call open.
We need to check only for MEI_FILE_CONNECTED in mei_cl_is_connected
in order to enable the communication with the clients before
MEI_DEV_ENABLED is set.
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The current maximum size of a queue in a queue pair is 128 MB. If
we increase that in the future, the queue pair allocation routines
may run into overflow issues. This change adds additional checks
to guard against this.
Acked-by: Andy King <acking@vmware.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Ensure that the size filled in by userland in the datagram header
matches the size of the buffer passed down in the IOCTL. Note that we
account for the size of the header itself in the check.
Acked-by: Jorgen Hansen <jhansen@vmware.com>
Acked-by: Aditya Sarwade <asarwade@vmware.com>
Signed-off-by: Andy King <acking@vmware.com>
Reported-by: David Ramos <daramos@stanford.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

As of 240ddd49 (vmw_vmci: Convert driver to use get_user_pages_fast())
we no longer user get_user_pages(), thus update the warning.

Also convert to pr_debug, which is a more appropriate level of logging.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge branch 'fix_ioremap_wc' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag into char-misc-next

We want those fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit b1a3f243 ("checkkconfigsymbols.py: make it Git aware")
mistakenly removed to print undefined Kconfig symbols in alphabetical
order.  Furthermore, the script does not print anything anymore when the
entire tree is checked (i.e., when no commit is specified).

This patch restores the sorted output and adds the missing print for the
default case.  Additionally, the file lists are now sorted as well which
(a) makes it easier to read and (b) makes the output deterministic.
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When ioremap_wc() or ioremap_cached() are used without first including
asm/pgtable.h, the _PAGE_CACHEABLE or _PAGE_WR_COMBINE definitions
aren't found, resulting in build errors like the following (in
next-20150323 due to "lib: devres: add a helper function for
ioremap_wc"):

lib/devres.c: In function ‘devm_ioremap_wc’:
lib/devres.c:91: error: ‘_PAGE_WR_COMBINE’ undeclared

We can't easily include asm/pgtable.h in asm/io.h due to dependency
problems, so split out the _PAGE_* definitions from asm/pgtable.h into a
separate asm/pgtable-bits.h header (as a couple of other architectures
already do), and include that in io.h instead.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Cc: Abhilash Kesavan <a.kesavan@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull bugfix for md from Neil Brown:
 "One fix for md in 4.0-rc4

  Regression in recent patch causes crash on error path"

* tag 'md/4.0-rc4-fix' of git://neil.brown.name/md:
  md: fix problems with freeing private data after ->run failure.

Pull driver core fixes from Greg KH:
 "Here are two bugfixes for things reported.  One regression in kernfs,
  and another issue fixed in the LZ4 code that was fixed in the
  "upstream" codebase that solves a reported kernel crash

  Both have been in linux-next for a while"

* tag 'driver-core-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  LZ4 : fix the data abort issue
  kernfs: handle poll correctly on 'direct_read' files.

Pull char/misc fixes from Greg KH:
 "Here are three fixes for 4.0-rc5 that revert 3 PCMCIA patches that
  were merged in 4.0-rc1 that cause regressions.  So let's revert them
  for now and they will be reworked and resent sometime in the future.

  All have been tested in linux-next for a while"

* tag 'char-misc-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Revert "pcmcia: add a new resource manager for non ISA systems"
  Revert "pcmcia: fix incorrect bracketing on a test"
  Revert "pcmcia: add missing include for new pci resource handler"

Pull staging driver fixes from Greg KH:
 "Here are four small staging driver fixes, all for the vt6656 and
  vt6655 drivers, that resolve some reported issues with them.

  All of these patches have been in linux next for a while"

* tag 'staging-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  vt6655: Fix late setting of byRFType.
  vt6655: RFbSetPower fix missing rate RATE_12M
  staging: vt6656: vnt_rf_setpower: fix missing rate RATE_12M
  staging: vt6655: vnt_tx_packet fix dma_idx selection.

Pull tty/serial driver fix from Greg KH:
 "Here's a single 8250 serial driver that fixes a reported deadlock with
  the serial console and the tty driver.

  It's been in linux-next for a while now"

* tag 'tty-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250_dw: Fix deadlock in LCR workaround

Pull USB / PHY driver fixes from Greg KH:
 "Here's a number of USB and PHY driver fixes for 4.0-rc5.

  The largest thing here is a revert of a gadget function driver patch
  that removes 500 lines of code.  Other than that, it's a number of
  reported bugs fixes and new quirk/id entries.

  All have been in linux-next for a while"

* tag 'usb-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
  usb: common: otg-fsm: only signal connect after switching to peripheral
  uas: Add US_FL_NO_ATA_1X for Initio Corporation controllers / devices
  USB: ehci-atmel: rework clk handling
  MAINTAINERS: add entry for USB OTG FSM
  usb: chipidea: otg: add a_alt_hnp_support response for B device
  phy: omap-usb2: Fix missing clk_prepare call when using old dt name
  phy: ti/omap: Fix modalias
  phy: core: Fixup return value of phy_exit when !pm_runtime_enabled
  phy: miphy28lp: Convert to devm_kcalloc and fix wrong sizof
  phy: miphy365x: Convert to devm_kcalloc and fix wrong sizeof
  phy: twl4030-usb: Remove redundant assignment for twl->linkstat
  phy: exynos5-usbdrd: Fix off-by-one valid value checking for args->args[0]
  phy: Find the right match in devm_phy_destroy()
  phy: rockchip-usb: Fixup rockchip_usb_phy_power_on failure path
  phy: ti-pipe3: Simplify ti_pipe3_dpll_wait_lock implementation
  phy: samsung-usb2: Remove NULL terminating entry from phys array
  phy: hix5hd2-sata: Check return value of platform_get_resource
  phy: exynos-dp-video: Kill exynos_dp_video_phy_pwr_isol function
  Revert "usb: gadget: zero: Add support for interrupt EP"
  Revert "xhci: Clear the host side toggle manually when endpoint is 'soft reset'"
  ...

Pull slave dmaengine fixes from Vinod Koul:
 "Four fixes for dw, pl08x, imx-sdma and at_hdmac driver.  Nothing
  unusual here, simple fixes to these drivers"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: pl08x: Define capabilities for generic capabilities reporting
  dmaengine: dw: append MODULE_ALIAS for platform driver
  dmaengine: imx-sdma: switch to dynamic context mode after script loaded
  dmaengine: at_hdmac: Fix calculation of the residual bytes

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are fixes for recent regressions (PCI/ACPI resources and at91
  RTC locking), a stable-candidate powercap RAPL driver fix and two ARM
  cpuidle fixes (one stable-candidate too).

  Specifics:

   - Revert a recent PCI commit related to IRQ resources management that
     introduced a regression for drivers attempting to bind to devices
     whose previous drivers did not balance pci_enable_device() and
     pci_disable_device() as expected (Rafael J Wysocki).

   - Fix a deadlock in at91_rtc_interrupt() introduced by a typo in a
     recent commit related to wakeup interrupt handling (Dan Carpenter).

   - Allow the power capping RAPL (Running-Average Power Limit) driver
     to use different energy units for domains within one CPU package
     which is necessary to handle Intel Haswell EP processors correctly
     (Jacob Pan).

   - Improve the cpuidle mvebu driver's handling of Armada XP SoCs by
     updating the target residency and exit latency numbers for those
     chips (Sebastien Rannou).

   - Prevent the cpuidle mvebu driver from calling cpu_pm_enter() twice
     in a row before cpu_pm_exit() is called on the same CPU which
     breaks the core's assumptions regarding the usage of those
     functions (Gregory Clement)"

* tag 'pm+acpi-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "x86/PCI: Refine the way to release PCI IRQ resources"
  rtc: at91rm9200: double locking bug in at91_rtc_interrupt()
  powercap / RAPL: handle domains with different energy units
  cpuidle: mvebu: Update cpuidle thresholds for Armada XP SOCs
  cpuidle: mvebu: Fix the CPU PM notifier usage

Pull drm updates from Dave Airlie:
 "A bunch of fixes across drivers:

  radeon:
     disable two ended allocation for now, it breaks some stuff

  amdkfd:
     misc fixes

  nouveau:
     fix irq loop problem, add basic support for GM206 (new hw)

  i915:
     fix some WARNs people were seeing

  exynos:
     fix some iommu interactions causing boot failures"

* git://people.freedesktop.org/~airlied/linux:
  drm/radeon: drop ttm two ended allocation
  drm/exynos: fix the initialization order in FIMD
  drm/exynos: fix typo config name correctly.
  drm/exynos: Check for NULL dereference of crtc
  drm/exynos: IS_ERR() vs NULL bug
  drm/exynos: remove unused files
  drm/i915: Make sure the primary plane is enabled before reading out the fb state
  drm/nouveau/bios: fix i2c table parsing for dcb 4.1
  drm/nouveau/device/gm100: Basic GM206 bring up (as copy of GM204)
  drm/nouveau/device: post write to NV_PMC_BOOT_1 when flipping endian switch
  drm/nouveau/gr/gf100: fix some accidental or'ing of buffer addresses
  drm/nouveau/fifo/nv04: remove the loop from the interrupt handler
  drm/radeon: Changing number of compute pipe lines
  drm/amdkfd: Fix SDMA queue init. in non-HWS mode
  drm/amdkfd: destroy mqd when destroying kernel queue
  drm/i915: Ensure plane->state->fb stays in sync with plane->fb

Merge tag 'devicetree-fixes-for-4.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull more DeviceTree fixes vfom Rob Herring:

 - revert setting stdout-path as preferred console.  This caused
   regressions in PowerMACs and other systems.

 - yet another fix for stdout-path option parsing.

 - fix error path handling in of_irq_parse_one

* tag 'devicetree-fixes-for-4.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  Revert "of: Fix premature bootconsole disable with 'stdout-path'"
  of: handle both '/' and ':' in path strings
  of: unittest: Add option string test case with longer path
  of/irq: Fix of_irq_parse_one() returned error codes

Pull SCSI target fixes from Nicholas Bellinger:
 "Here are current target-pending fixes for v4.0-rc5 code that have made
  their way into the queue over the last weeks.

  The fixes this round include:

   - Fix long-standing iser-target logout bug related to early
     conn_logout_comp completion, resulting in iscsi_conn use-after-tree
     OOpsen.  (Sagi + nab)

   - Fix long-standing tcm_fc bug in ft_invl_hw_context() failure
     handing for DDP hw offload.  (DanC)

   - Fix incorrect use of unprotected __transport_register_session() in
     tcm_qla2xxx + other single local se_node_acl fabrics.  (Bart)

   - Fix reference leak in target_submit_cmd() -> target_get_sess_cmd()
     for ack_kref=1 failure path.  (Bart)

   - Fix pSCSI backend ->get_device_type() statistics OOPs with
     un-configured device.  (Olaf + nab)

   - Fix virtual LUN=0 target_configure_device failure OOPs at modprobe
     time.  (Claudio + nab)

   - Fix FUA write false positive failure regression in v4.0-rc1 code.
     (Christophe Vu-Brugier + HCH)"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0
  target: Fix virtual LUN=0 target_configure_device failure OOPs
  target/pscsi: Fix NULL pointer dereference in get_device_type
  tcm_fc: missing curly braces in ft_invl_hw_context()
  target: Fix reference leak in target_get_sess_cmd() error path
  loop/usb/vhost-scsi/xen-scsiback: Fix use of __transport_register_session
  tcm_qla2xxx: Fix incorrect use of __transport_register_session
  iscsi-target: Avoid early conn_logout_comp for iser connections
  Revert "iscsi-target: Avoid IN_LOGOUT failure case for iser-target"
  target: Disallow changing of WRITE cache/FUA attrs after export

Pull devicemapper fixes from Mike Snitzer:
 "A handful of stable fixes for DM:
   - fix thin target to always zero-fill reads to unprovisioned blocks
   - fix to interlock device destruction's suspend from internal
     suspends
   - fix 2 snapshot exception store handover bugs
   - fix dm-io to cope with DISCARD and WRITE_SAME capabilities changing"

* tag 'dm-4.0-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm io: deal with wandering queue limits when handling REQ_DISCARD and REQ_WRITE_SAME
  dm snapshot: suspend merging snapshot when doing exception handover
  dm snapshot: suspend origin when doing exception handover
  dm: hold suspend_lock while suspending device during device deletion
  dm thin: fix to consistently zero-fill reads to unprovisioned blocks

Pull btrfs fixes from Chris Mason:
 "Most of these are fixing extent reservation accounting, or corners
  with tree writeback during commit.

  Josef's set does add a test, which isn't strictly a fix, but it'll
  keep us from making this same mistake again"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix outstanding_extents accounting in DIO
  Btrfs: add sanity test for outstanding_extents accounting
  Btrfs: just free dummy extent buffers
  Btrfs: account merges/splits properly
  Btrfs: prepare block group cache before writing
  Btrfs: fix ASSERT(list_empty(&cur_trans->dirty_bgs_list)
  Btrfs: account for the correct number of extents for delalloc reservations
  Btrfs: fix merge delalloc logic
  Btrfs: fix comp_oper to get right order
  Btrfs: catch transaction abortion after waiting for it
  btrfs: fix sizeof format specifier in btrfs_check_super_valid()

Pull nfsd bufix from Bruce Fields:
 "This is a fix for a crash easily triggered by 4.1 activity to a server
  built with CONFIG_NFSD_PNFS.

  There are some more bugfixes queued up that I intend to pass along
  next week, but this is the most critical"

* 'for-4.0' of git://linux-nfs.org/~bfields/linux:
  Subject: nfsd: don't recursively call nfsd4_cb_layout_fail

Pull UBI fix from Artem Bityutskiy:
 "This fixes a bug introduced during the v4.0 merge window where we
  forgot to put braces where they should be"

* tag 'upstream-4.0-rc5' of git://git.infradead.org/linux-ubifs:
  UBI: fix missing brace control flow

Pull arm64 fixes from Catalin Marinas:

 - mm switching fix where the kernel pgd ends up in the user TTBR0 after
   returning from an EFI run-time services call

 - fix __GFP_ZERO handling for atomic pool and CMA DMA allocations (the
   generic code does get the gfp flags, so it's left with the arch code
   to memzero accordingly)

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: Honor __GFP_ZERO in dma allocations
  arm64: efi: don't restore TTBR0 if active_mm points at init_mm

Pull ARM fixes from Russell King:
 "Another few ARM fixes.  Fabrice fixed the L2 cache DT parsing to allow
  prefetch configuration to be specified even when the cache size
  parsing fails.

  Laura noticed that the setting of page attributes wasn't working for
  modules due to is_module_addr() always returning false.

  Marc Gonzalez (aka Mason) noticed a potential latent bug with the way
  we read one of the CPUID registers (where we could attempt to read a
  non-present CPUID register which may fault.)

  I've fixed an issue where 32-bit DMA masks were failing with memory
  which extended to the top of physical address space, and I've also
  added debugging output of the page tables when we hit a data access
  exception which we don't specifically handle - prompted by the lack of
  information in a bug report"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8313/1: Use read_cpuid_ext() macro instead of inline asm
  ARM: 8311/1: Don't use is_module_addr in setting page attributes
  ARM: 8310/1: l2c: Fix prefetch settings dt parsing
  ARM: dump pgd, pmd and pte states on unhandled data abort faults
  ARM: dma-api: fix off-by-one error in __dma_supported()

* pm-cpuidle:
  cpuidle: mvebu: Update cpuidle thresholds for Armada XP SOCs
  cpuidle: mvebu: Fix the CPU PM notifier usage

* powercap:
  powercap / RAPL: handle domains with different energy units

* irq-pm:
  rtc: at91rm9200: double locking bug in at91_rtc_interrupt()

* acpi-resources:
  Revert "x86/PCI: Refine the way to release PCI IRQ resources"

If ->run() fails, it can either free the data structures it
allocated, or leave that task to ->free() which will be called
on failures.

However:
  md.c calls ->free() even if ->private_data is NULL, which
     causes problems in some personalities.
  raid0.c frees the data, but doesn't clear ->private_data,
     which will become a problem when we fix md.c

So better fix both these issues at once.
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Fixes: 5aa61f42
URL: https://bugzilla.kernel.org/show_bug.cgi?id=94381Signed-off-by: NeilBrown <neilb@suse.de>

Current implementation doesn't zero out the pages allocated.
Honor the __GFP_ZERO flag and zero out if set.

Cc: <stable@vger.kernel.org> # v3.14+
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

init_mm isn't a normal mm: it has swapper_pg_dir as its pgd (which
contains kernel mappings) and is used as the active_mm for the idle
thread.

When restoring the pgd after an EFI call, we write current->active_mm
into TTBR0. If the current task is actually the idle thread (e.g. when
initialising the EFI RTC before entering userspace), then the TLB can
erroneously populate itself with junk global entries as a result of
speculative table walks.

When we do eventually return to userspace, the task can end up hitting
these junk mappings leading to lockups, corruption or crashes.

This patch fixes the problem in the same way as the CPU suspend code by
ensuring that we never switch to the init_mm in efi_set_pgd and instead
point TTBR0 at the zero page. A check is also added to cpu_switch_mm to
BUG if we get passed swapper_pg_dir.
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Fixes: f3cdfd23 ("arm64/efi: move SetVirtualAddressMap() to UEFI stub")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Commit b4b55cda (Refine the way to release PCI IRQ resources)
introduced a regression in the PCI IRQ resource management by causing
the IRQ resource of a device, established when pci_enabled_device()
is called on a fully disabled device, to be released when the driver
is unbound from the device, regardless of the enable_cnt.

This leads to the situation that an ill-behaved driver can now make a
device unusable to subsequent drivers by an imbalance in their use of
pci_enable/disable_device().  That is a serious problem for secondary
drivers like vfio-pci, which are innocent of the transgressions of
the previous driver.

Since the solution of this problem is not immediate and requires
further discussion, revert commit b4b55cda and the issue it was
supposed to address (a bug related to xen-pciback) will be taken
care of in a different way going forward.
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>