Two i915 regression fixes.

* tag 'drm-intel-fixes-2016-03-11' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Actually retry with bit-banging after GMBUS timeout
  drm/i915: Fix bogus dig_port_map[] assignment for pre-HSW

Pull ARM SoC fixes from Olof Johansson:
 "Two more fixes for 4.5:

   - One is a fix for OMAP that is urgently needed to avoid DRA7xx chips
     from premature aging, by always keeping the Ethernet clock enabled.

   - The other solves a I/O memory layout issue on Armada, where SROM
     and PCI memory windows were conflicting in some configurations"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: mvebu: fix overlap of Crypto SRAM with PCIe memory window
  ARM: dts: dra7: do not gate cpsw clock due to errata i877
  ARM: OMAP2+: hwmod: Introduce ti,no-idle dt property

Pull media fix from Mauro Carvalho Chehab:
 "One last time fix: It adds a code that prevents some media tools like
  media-ctl to hide some entities that have their IDs out of the range
  expected by those apps"

* tag 'media/v4.5-5' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] media-device: map new functions into old types for legacy API

When the Crypto SRAM mappings were added to the Device Tree files
describing the Armada XP boards in commit c466d997 ("ARM: mvebu:
define crypto SRAM ranges for all armada-xp boards"), the fact that
those mappings were overlaping with the PCIe memory aperture was
overlooked. Due to this, we currently have for all Armada XP platforms
a situation that looks like this:

Memory mapping on Armada XP boards with internal registers at
0xf1000000:

 - 0x00000000 -> 0xf0000000	3.75G 	RAM
 - 0xf0000000 -> 0xf1000000	16M	NOR flashes (AXP GP / AXP DB)
 - 0xf1000000 -> 0xf1100000	1M	internal registers
 - 0xf8000000 -> 0xffe0000	126M	PCIe memory aperture
 - 0xf8100000 -> 0xf8110000	64KB	Crypto SRAM #0	=> OVERLAPS WITH PCIE !
 - 0xf8110000 -> 0xf8120000	64KB	Crypto SRAM #1	=> OVERLAPS WITH PCIE !
 - 0xffe00000 -> 0xfff00000	1M	PCIe I/O aperture
 - 0xfff0000  -> 0xffffffff	1M	BootROM

The overlap means that when PCIe devices are added, depending on their
memory window needs, they might or might not be mapped into the
physical address space. Indeed, they will not be mapped if the area
allocated in the PCIe memory aperture by the PCI core overlaps with
one of the Crypto SRAM. Typically, a Intel IGB PCIe NIC that needs 8MB
of PCIe memory will see its PCIe memory window allocated from
0xf80000000 for 8MB, which overlaps with the Crypto SRAM windows. Due
to this, the PCIe window is not created, and any attempt to access the
PCIe window makes the kernel explode:

[    3.302213] igb: Copyright (c) 2007-2014 Intel Corporation.
[    3.307841] pci 0000:00:09.0: enabling device (0140 -> 0143)
[    3.313539] mvebu_mbus: cannot add window '4:f8', conflicts with another window
[    3.320870] mvebu-pcie soc:pcie-controller: Could not create MBus window at [mem 0xf8000000-0xf87fffff]: -22
[    3.330811] Unhandled fault: external abort on non-linefetch (0x1008) at 0xf08c0018

This problem does not occur on Armada 370 boards, because we use the
following memory mapping (for boards that have internal registers at
0xf1000000):

 - 0x00000000 -> 0xf0000000	3.75G 	RAM
 - 0xf0000000 -> 0xf1000000	16M	NOR flashes (AXP GP / AXP DB)
 - 0xf1000000 -> 0xf1100000	1M	internal registers
 - 0xf1100000 -> 0xf1110000	64KB	Crypto SRAM #0 => OK !
 - 0xf8000000 -> 0xffe0000	126M	PCIe memory
 - 0xffe00000 -> 0xfff00000	1M	PCIe I/O
 - 0xfff0000  -> 0xffffffff	1M	BootROM

Obviously, the solution is to align the location of the Crypto SRAM
mappings of Armada XP to be similar with the ones on Armada 370, i.e
have them between the "internal registers" area and the beginning of
the PCIe aperture.

However, we have a special case with the OpenBlocks AX3-4 platform,
which has a 128 MB NOR flash. Currently, this NOR flash is mapped from
0xf0000000 to 0xf8000000. This is possible because on OpenBlocks
AX3-4, the internal registers are not at 0xf1000000. And this explains
why the Crypto SRAM mappings were not configured at the same place on
Armada XP.

Hence, the solution is two-fold:

 (1) Move the NOR flash mapping on Armada XP OpenBlocks AX3-4 from
     0xe8000000 to 0xf0000000. This frees the 0xf0000000 ->
     0xf80000000 space.

 (2) Move the Crypto SRAM mappings on Armada XP to be similar to
     Armada 370 (except of course that Armada XP has two Crypto SRAM
     and not one).

After this patch, the memory mapping on Armada XP boards with
registers at 0xf1 is:

 - 0x00000000 -> 0xf0000000	3.75G 	RAM
 - 0xf0000000 -> 0xf1000000	16M	NOR flashes (AXP GP / AXP DB)
 - 0xf1000000 -> 0xf1100000	1M	internal registers
 - 0xf1100000 -> 0xf1110000	64KB	Crypto SRAM #0
 - 0xf1110000 -> 0xf1120000	64KB	Crypto SRAM #1
 - 0xf8000000 -> 0xffe0000	126M	PCIe memory
 - 0xffe00000 -> 0xfff00000	1M	PCIe I/O
 - 0xfff0000  -> 0xffffffff	1M	BootROM

And the memory mapping for the special case of the OpenBlocks AX3-4
(internal registers at 0xd0000000, NOR of 128 MB):

 - 0x00000000 -> 0xc0000000	3G 	RAM
 - 0xd0000000 -> 0xd1000000	1M	internal registers
 - 0xe800000  -> 0xf0000000	128M	NOR flash
 - 0xf1100000 -> 0xf1110000	64KB	Crypto SRAM #0
 - 0xf1110000 -> 0xf1120000	64KB	Crypto SRAM #1
 - 0xf8000000 -> 0xffe0000	126M	PCIe memory
 - 0xffe00000 -> 0xfff00000	1M	PCIe I/O
 - 0xfff0000  -> 0xffffffff	1M	BootROM

Fixes: c466d997 ("ARM: mvebu: define crypto SRAM ranges for all armada-xp boards")
Reported-by: Phil Sutter <phil@nwl.cc>
Cc: Phil Sutter <phil@nwl.cc>
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

Pull dmaengine fixes from Vinod Koul:
 "Two fixes showed up in last few days, and they should be included in
  4.5.  Summary:

  Two more late fixes to drivers, nothing major here:

   - A memory leak fix in fsdma unmap the dma descriptors on freeup

   - A fix in xdmac driver for residue calculation of dma descriptor"

* tag 'dmaengine-fix-4.5' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: at_xdmac: fix residue computation
  dmaengine: fsldma: fix memory leak

Pull power management and ACPI fixes from Rafael Wysocki:
 "Two more fixes for issues introduced recently, one in the generic
  device properties framework and one in ACPICA.

  Specifics:

   - Revert a recent ACPICA commit that has been reverted upstream,
     because it caused problems to happen on user systems and the
     problem it attempted to address will not be relevant any more after
     upcoming ACPI specification changes (Bob Moore).

   - Fix crash in the generic device properties framework introduced by
     a recent change that forgot to check pointers against error values
     in addition to checking them against NULL (Heikki Krogerus)"

* tag 'pm+acpi-4.5-final' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  device property: fwnode->secondary may contain ERR_PTR(-ENODEV)
  ACPICA: Revert "Parser: Fix for SuperName method invocation"

Pull xfs fixes from Dave Chinner:
 "This is a fix for a regression introduced in 4.5-rc1 by the new torn
  log write detection code.  The regression only affects people moving a
  clean filesystem between machines/kernels of different architecture
  (such as changing between 32 bit and 64 bit kernels), but this is the
  recommended (and only!) safe way to migrate a filesystem between
  architectures so we really need to ensure it works.

  The changes are larger than I'd prefer right at the end of the release
  cycle, but the majority of the change is just factoring code to enable
  the detection of a clean log at the correct time to avoid this issue.

  Changes:

   - Only perform torn log write detection on dirty logs.  This prevents
     failures being detected due to a clean filesystem being moved
     between machines or kernels of different architectures (e.g.  32 ->
     64 bit, BE -> LE, etc).  This fixes a regression introduced by the
     torn log write detection in 4.5-rc1"

* tag 'xfs-for-linus-4.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: only run torn log write detection on dirty logs
  xfs: refactor in-core log state update to helper
  xfs: refactor unmount record detection into helper
  xfs: separate log head record discovery from verification

Pull vfs fixes from Al Viro:
 "A couple of fixes: Fix for my dumb braino in ncpfs and a long-standing
  breakage on recovery from failed rename() in jffs2"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  jffs2: reduce the breakage on recovery from halfway failed rename()
  ncpfs: fix a braino in OOM handling in ncp_fill_cache()

* device-properties-fixes:
  device property: fwnode->secondary may contain ERR_PTR(-ENODEV)

* acpica-fixes:
  ACPICA: Revert "Parser: Fix for SuperName method invocation"

After the GMBUS transfer times out, we set force_bit=1 and
return -EAGAIN expecting the i2c core to call the .master_xfer
hook again so that we will retry the same transfer via bit-banging.
This is in case the gmbus hardware is somehow faulty.

Unfortunately we left adapter->retries to 0, meaning the i2c core
didn't actually do the retry. Let's tell the core we want one retry
when we return -EAGAIN.

Note that i2c-algo-bit also uses this retry count for some internal
retries, so we'll end up increasing those a bit as well.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: bffce907 ("drm/i915: abstract i2c bit banging fallback in gmbus xfer")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457366220-29409-2-git-send-email-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>
(cherry picked from commit 8b1f165a)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Pull KVM fixes from Paolo Bonzini:
 "A few simple fixes for ARM, x86, PPC and generic code.

  The x86 MMU fix is a bit larger because the surrounding code needed a
  cleanup, but nothing worrisome"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: MMU: fix reserved bit check for ept=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0
  KVM: MMU: fix ept=0/pte.u=1/pte.w=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0 combo
  kvm: cap halt polling at exactly halt_poll_ns
  KVM: s390: correct fprs on SIGP (STOP AND) STORE STATUS
  KVM: VMX: disable PEBS before a guest entry
  KVM: PPC: Book3S HV: Sanitize special-purpose register values on guest exit

Pull arm64 fixes from Will Deacon:
 "I thought we were done for 4.5, but then the 64k-page chaps came
  crawling out of the woodwork.  *sigh*

  The vmemmap fix I sent for -rc7 caused a regression with 64k pages and
  sparsemem and at some point during the release cycle the new hugetlb
  code using contiguous ptes started failing the libhugetlbfs tests with
  64k pages enabled.

  So here are a couple of patches that fix the vmemmap alignment and
  disable the new hugetlb page sizes whilst a proper fix is being
  developed:

   - Temporarily disable huge pages built using contiguous ptes

   - Ensure vmemmap region is sufficiently aligned for sparsemem
     sections"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: hugetlb: partial revert of 66b3923a
  arm64: account for sparsemem section alignment when choosing vmemmap offset

Pull s390 fixes from Martin Schwidefsky:
 "Three bug fixes:
   - The fix for the page table corruption (CVE-2016-2143)
   - The diagnose statistics introduced a regression for the dasd diag
     driver
   - Boot crash on systems without the set-program-parameters facility"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/mm: four page table levels vs. fork
  s390/cpumf: Fix lpp detection
  s390/dasd: fix diag 0x250 inline assembly

The legacy media controller userspace API exposes entity types that
carry both type and function information. The new API replaces the type
with a function. It preserves backward compatibility by defining legacy
functions for the existing types and using them in drivers.

This works fine, as long as newer entity functions won't be added.

Unfortunately, some tools, like media-ctl with --print-dot argument
rely on the now legacy MEDIA_ENT_T_V4L2_SUBDEV and MEDIA_ENT_T_DEVNODE
numeric ranges to identify what entities will be shown.

Also, if the entity doesn't match those ranges, it will ignore the
major/minor information on devnodes, and won't be getting the devnode
name via udev or sysfs.

As we're now adding devices outside the old range, the legacy ioctl
needs to map the new entity functions into a type at the old range,
or otherwise we'll have a regression.

Detected on all released media-ctl versions (e. g. versions <= 1.10).

Fix this by deriving the type from the function to emulate the legacy
API if the function isn't in the legacy functions range.
Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

When computing the residue we need two pieces of information: the current
descriptor and the remaining data of the current descriptor. To get
that information, we need to read consecutively two registers but we
can't do it in an atomic way. For that reason, we have to check manually
that current descriptor has not changed.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Suggested-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Reported-by: David Engraf <david.engraf@sysgo.com>
Tested-by: David Engraf <david.engraf@sysgo.com>
Fixes: e1f7c9ee ("dmaengine: at_xdmac: creation of the atmel
eXtended DMA Controller driver")
Cc: stable@vger.kernel.org #4.1 and later
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

KVM has special logic to handle pages with pte.u=1 and pte.w=0 when
CR0.WP=1.  These pages' SPTEs flip continuously between two states:
U=1/W=0 (user and supervisor reads allowed, supervisor writes not allowed)
and U=0/W=1 (supervisor reads and writes allowed, user writes not allowed).

When SMEP is in effect, however, U=0 will enable kernel execution of
this page.  To avoid this, KVM also sets NX=1 in the shadow PTE together
with U=0, making the two states U=1/W=0/NX=gpte.NX and U=0/W=1/NX=1.
When guest EFER has the NX bit cleared, the reserved bit check thinks
that the latter state is invalid; teach it that the smep_andnot_wp case
will also use the NX bit of SPTEs.

Cc: stable@vger.kernel.org
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.inel.com>
Fixes: c258b62bSigned-off-by: Paolo Bonzini <pbonzini@redhat.com>

Yes, all of these are needed. :) This is admittedly a bit odd, but
kvm-unit-tests access.flat tests this if you run it with "-cpu host"
and of course ept=0.

KVM runs the guest with CR0.WP=1, so it must handle supervisor writes
specially when pte.u=1/pte.w=0/CR0.WP=0.  Such writes cause a fault
when U=1 and W=0 in the SPTE, but they must succeed because CR0.WP=0.
When KVM gets the fault, it sets U=0 and W=1 in the shadow PTE and
restarts execution.  This will still cause a user write to fault, while
supervisor writes will succeed.  User reads will fault spuriously now,
and KVM will then flip U and W again in the SPTE (U=1, W=0).  User reads
will be enabled and supervisor writes disabled, going back to the
originary situation where supervisor writes fault spuriously.

When SMEP is in effect, however, U=0 will enable kernel execution of
this page.  To avoid this, KVM also sets NX=1 in the shadow PTE together
with U=0.  If the guest has not enabled NX, the result is a continuous
stream of page faults due to the NX bit being reserved.

The fix is to force EFER.NX=1 even if the CPU is taking care of the EFER
switch.  (All machines with SMEP have the CPU_LOAD_IA32_EFER vm-entry
control, so they do not use user-return notifiers for EFER---if they did,
EFER.NX would be forced to the same value as the host).

There is another bug in the reserved bit check, which I've split to a
separate patch for easier application to stable kernels.

Cc: stable@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Fixes: f6577a5fSigned-off-by: Paolo Bonzini <pbonzini@redhat.com>

The fork of a process with four page table levels is broken since
git commit 6252d702 "[S390] dynamic page tables."

All new mm contexts are created with three page table levels and
an asce limit of 4TB. If the parent has four levels dup_mmap will
add vmas to the new context which are outside of the asce limit.
The subsequent call to copy_page_range will walk the three level
page table structure of the new process with non-zero pgd and pud
indexes. This leads to memory clobbers as the pgd_index *and* the
pud_index is added to the mm->pgd pointer without a pgd_deref
in between.

The init_new_context() function is selecting the number of page
table levels for a new context. The function is used by mm_init()
which in turn is called by dup_mm() and mm_alloc(). These two are
used by fork() and exec(). The init_new_context() function can
distinguish the two cases by looking at mm->context.asce_limit,
for fork() the mm struct has been copied and the number of page
table levels may not change. For exec() the mm_alloc() function
set the new mm structure to zero, in this case a three-level page
table is created as the temporary stack space is located at
STACK_TOP_MAX = 4TB.

This fixes CVE-2016-2143.
Reported-by: Marcin Kościelnicki <koriakin@0x04.net>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Pull spi fixes from Mark Brown:
 "A few driver specific fixes for the Rockchip and i.MX SPI controllers,
  especially for the i.MX they're annoying bugs if you run into them"

* tag 'spi-fix-v4.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: imx: fix spi resource leak with dma transfer
  spi: imx: allow only WML aligned transfers to use DMA
  spi: rockchip: add missing spi_master_put
  spi: rockchip: disable runtime pm when in err case

Pull ext4 fix from Ted Ts'o:
 "This fixes a regression which crept in v4.5-rc5"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: iterate over buffer heads correctly in move_extent_per_page()

Pull drm fixes from Dave Airlie:
 "A few imx fixes I missed from a couple of weeks ago, they still aren't
  that big and fix some regression and a fail to boot problem.

  Other than that, a couple of regression fixes for radeon/amdgpu, one
  regression fix for vmwgfx and one regression fix for tda998x"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  Revert "drm/radeon/pm: adjust display configuration after powerstate"
  drm/amdgpu/dp: add back special handling for NUTMEG
  drm/radeon/dp: add back special handling for NUTMEG
  drm/i2c: tda998x: Choose between atomic or non atomic dpms helper
  drm/vmwgfx: Add back ->detect() and ->fill_modes()
  drm/radeon: Fix error handling in radeon_flip_work_func.
  drm/amdgpu: Fix error handling in amdgpu_flip_work_func.
  drm/imx: Add missing DRM_FORMAT_RGB565 to ipu_plane_formats
  drm/imx: notify DRM core about CRTC vblank state
  gpu: ipu-v3: Reset IPU before activating IRQ
  gpu: ipu-v3: Do not bail out on missing optional port nodes

Merge tag 'trace-fixes-v4.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "I previously sent a fix that prevents all trace events from being
  called if the current cpu is offline.

  But I forgot that in 3.18, we added lockdep checks to test RCU usage
  even when the event is disabled.  Although there cannot be any bug
  when a cpu is going offline, we now get false warnings triggered by
  the added checks of the event being disabled.

  I removed the check from the tracepoint code itself, and added it to
  the condition section (which is "1" for 'no condition').  This way the
  online cpu check will get checked in all the right locations"

* tag 'trace-fixes-v4.5-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix check for cpu online when event is disabled

In commit bcff2488 ("ext4: don't read blocks from disk after extents
being swapped") bh is not updated correctly in the for loop and wrong
data has been written to disk. generic/324 catches this on sub-page
block size ext4.

Fixes: bcff2488 ("ext4: don't read blocks from disk after extentsbeing swapped")
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Merge fixes from Andrew Morton:
 "13 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  dma-mapping: avoid oops when parameter cpu_addr is null
  mm/hugetlb: use EOPNOTSUPP in hugetlb sysctl handlers
  memremap: check pfn validity before passing to pfn_to_page()
  mm, thp: fix migration of PTE-mapped transparent huge pages
  dax: check return value of dax_radix_entry()
  ocfs2: fix return value from ocfs2_page_mkwrite()
  arm64: kasan: clear stale stack poison
  sched/kasan: remove stale KASAN poison after hotplug
  kasan: add functions to clear stack poison
  mm: fix mixed zone detection in devm_memremap_pages
  list: kill list_force_poison()
  mm: __delete_from_page_cache show Bad page if mapped
  mm/hugetlb: hugetlb_no_page: rate-limit warning message

To keep consistent with kfree, which tolerate ptr is NULL.  We do this
because sometimes we may use goto statement, so that success and failure
case can share parts of the code.  But unfortunately, dma_free_coherent
called with parameter cpu_addr is null will cause oops, such as showed
below:

  Unable to handle kernel paging request at virtual address ffffffc020d3b2b8
  pgd = ffffffc083a61000
  [ffffffc020d3b2b8] *pgd=0000000000000000, *pud=0000000000000000
  CPU: 4 PID: 1489 Comm: malloc_dma_1 Tainted: G           O    4.1.12 #1
  Hardware name: ARM64 (DT)
  PC is at __dma_free_coherent.isra.10+0x74/0xc8
  LR is at __dma_free+0x9c/0xb0
  Process malloc_dma_1 (pid: 1489, stack limit = 0xffffffc0837fc020)
  [...]
  Call trace:
    __dma_free_coherent.isra.10+0x74/0xc8
    __dma_free+0x9c/0xb0
    malloc_dma+0x104/0x158 [dma_alloc_coherent_mtmalloc]
    kthread+0xec/0xfc
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Replace ENOTSUPP with EOPNOTSUPP.  If hugepages are not supported, this
value is propagated to userspace.  EOPNOTSUPP is part of uapi and is
widely supported by libc libraries.

It gives nicer message to user, rather than:

  # cat /proc/sys/vm/nr_hugepages
  cat: /proc/sys/vm/nr_hugepages: Unknown error 524

And also LTP's proc01 test was failing because this ret code (524)
was unexpected:

  proc01      1  TFAIL  :  proc01.c:396: read failed: /proc/sys/vm/nr_hugepages: errno=???(524): Unknown error 524
  proc01      2  TFAIL  :  proc01.c:396: read failed: /proc/sys/vm/nr_hugepages_mempolicy: errno=???(524): Unknown error 524
  proc01      3  TFAIL  :  proc01.c:396: read failed: /proc/sys/vm/nr_overcommit_hugepages: errno=???(524): Unknown error 524
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In memremap's helper function try_ram_remap(), we dereference a struct
page pointer that was derived from a PFN that is known to be covered by
a 'System RAM' iomem region, and is thus assumed to be a 'valid' PFN,
i.e., a PFN that has a struct page associated with it and is covered by
the kernel direct mapping.

However, the assumption that there is a 1:1 relation between the System
RAM iomem region and the kernel direct mapping is not universally valid
on all architectures, and on ARM and arm64, 'System RAM' may include
regions for which pfn_valid() returns false.

Generally speaking, both __va() and pfn_to_page() should only ever be
called on PFNs/physical addresses for which pfn_valid() returns true, so
add that check to try_ram_remap().
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We don't have native support of THP migration, so we have to split huge
page into small pages in order to migrate it to different node.  This
includes PTE-mapped huge pages.

I made mistake in refcounting patchset: we don't actually split
PTE-mapped huge page in queue_pages_pte_range(), if we step on head
page.

The result is that the head page is queued for migration, but none of
tail pages: putting head page on queue takes pin on the page and any
subsequent attempts of split_huge_pages() would fail and we skip queuing
tail pages.

unmap_and_move_huge_page() will eventually split the huge pages, but
only one of 512 pages would get migrated.

Let's fix the situation.

Fixes: 248db92d ("migrate_pages: try to split pages on queuing")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dax_pfn_mkwrite() previously wasn't checking the return value of the
call to dax_radix_entry(), which was a mistake.

Instead, capture this return value and return the appropriate VM_FAULT_
value.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ocfs2_page_mkwrite() could mistakenly return error code instead of
mkwrite status value.  Fix it.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Functions which the compiler has instrumented for KASAN place poison on
the stack shadow upon entry and remove this poison prior to returning.

In the case of cpuidle, CPUs exit the kernel a number of levels deep in
C code.  Any instrumented functions on this critical path will leave
portions of the stack shadow poisoned.

If CPUs lose context and return to the kernel via a cold path, we
restore a prior context saved in __cpu_suspend_enter are forgotten, and
we never remove the poison they placed in the stack shadow area by
functions calls between this and the actual exit of the kernel.

Thus, (depending on stackframe layout) subsequent calls to instrumented
functions may hit this stale poison, resulting in (spurious) KASAN
splats to the console.

To avoid this, clear any stale poison from the idle thread for a CPU
prior to bringing a CPU online.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Functions which the compiler has instrumented for KASAN place poison on
the stack shadow upon entry and remove this poision prior to returning.

In the case of CPU hotplug, CPUs exit the kernel a number of levels deep
in C code.  Any instrumented functions on this critical path will leave
portions of the stack shadow poisoned.

When a CPU is subsequently brought back into the kernel via a different
path, depending on stackframe, layout calls to instrumented functions
may hit this stale poison, resulting in (spurious) KASAN splats to the
console.

To avoid this, clear any stale poison from the idle thread for a CPU
prior to bringing a CPU online.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Functions which the compiler has instrumented for ASAN place poison on
the stack shadow upon entry and remove this poison prior to returning.

In some cases (e.g. hotplug and idle), CPUs may exit the kernel a
number of levels deep in C code.  If there are any instrumented
functions on this critical path, these will leave portions of the idle
thread stack shadow poisoned.

If a CPU returns to the kernel via a different path (e.g. a cold
entry), then depending on stack frame layout subsequent calls to
instrumented functions may use regions of the stack with stale poison,
resulting in (spurious) KASAN splats to the console.

Contemporary GCCs always add stack shadow poisoning when ASAN is
enabled, even when asked to not instrument a function [1], so we can't
simply annotate functions on the critical path to avoid poisoning.

Instead, this series explicitly removes any stale poison before it can
be hit.  In the common hotplug case we clear the entire stack shadow in
common code, before a CPU is brought online.

On architectures which perform a cold return as part of cpu idle may
retain an architecture-specific amount of stack contents.  To retain the
poison for this retained context, the arch code must call the core KASAN
code, passing a "watermark" stack pointer value beyond which shadow will
be cleared.  Architectures which don't perform a cold return as part of
idle do not need any additional code.

This patch (of 3):

Functions which the compiler has instrumented for KASAN place poison on
the stack shadow upon entry and remove this poision prior to returning.

In some cases (e.g.  hotplug and idle), CPUs may exit the kernel a number
of levels deep in C code.  If there are any instrumented functions on this
critical path, these will leave portions of the stack shadow poisoned.

If a CPU returns to the kernel via a different path (e.g.  a cold entry),
then depending on stack frame layout subsequent calls to instrumented
functions may use regions of the stack with stale poison, resulting in
(spurious) KASAN splats to the console.

To avoid this, we must clear stale poison from the stack prior to
instrumented functions being called.  This patch adds functions to the
KASAN core for removing poison from (portions of) a task's stack.  These
will be used by subsequent patches to avoid problems with hotplug and
idle.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The check for whether we overlap "System RAM" needs to be done at
section granularity.  For example a system with the following mapping:

    100000000-37bffffff : System RAM
    37c000000-837ffffff : Persistent Memory

...is unable to use devm_memremap_pages() as it would result in two
zones colliding within a given section.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Given we have uninitialized list_heads being passed to list_add() it
will always be the case that those uninitialized values randomly trigger
the poison value.  Especially since a list_add() operation will seed the
stack with the poison value for later stack allocations to trip over.

For example, see these two false positive reports:

  list_add attempted on force-poisoned entry
  WARNING: at lib/list_debug.c:34
  [..]
  NIP [c00000000043c390] __list_add+0xb0/0x150
  LR [c00000000043c38c] __list_add+0xac/0x150
  Call Trace:
    __list_add+0xac/0x150 (unreliable)
    __down+0x4c/0xf8
    down+0x68/0x70
    xfs_buf_lock+0x4c/0x150 [xfs]

  list_add attempted on force-poisoned entry(0000000000000500),
   new->next == d0000000059ecdb0, new->prev == 0000000000000500
  WARNING: at lib/list_debug.c:33
  [..]
  NIP [c00000000042db78] __list_add+0xa8/0x140
  LR [c00000000042db74] __list_add+0xa4/0x140
  Call Trace:
    __list_add+0xa4/0x140 (unreliable)
    rwsem_down_read_failed+0x6c/0x1a0
    down_read+0x58/0x60
    xfs_log_commit_cil+0x7c/0x600 [xfs]

Fixes: commit 5c2c2587 ("mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gup")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Eryu Guan <eguan@redhat.com>
Tested-by: Eryu Guan <eguan@redhat.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit e1534ae9 ("mm: differentiate page_mapped() from
page_mapcount() for compound pages") changed the famous
BUG_ON(page_mapped(page)) in __delete_from_page_cache() to
VM_BUG_ON_PAGE(page_mapped(page)): which gives us more info when
CONFIG_DEBUG_VM=y, but nothing at all when not.

Although it has not usually been very helpul, being hit long after the
error in question, we do need to know if it actually happens on users'
systems; but reinstating a crash there is likely to be opposed :)

In the non-debug case, pr_alert("BUG: Bad page cache") plus dump_page(),
dump_stack(), add_taint() - I don't really believe LOCKDEP_NOW_UNRELIABLE,
but that seems to be the standard procedure now.  Move that, or the
VM_BUG_ON_PAGE(), up before the deletion from tree: so that the
unNULLified page->mapping gives a little more information.

If the inode is being evicted (rather than truncated), it won't have any
vmas left, so it's safe(ish) to assume that the raised mapcount is
erroneous, and we can discount it from page_count to avoid leaking the
page (I'm less worried by leaking the occasional 4kB, than losing a
potential 2MB page with each 4kB page leaked).
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The warning message "killed due to inadequate hugepage pool" simply
indicates that SIGBUS was sent, not that the process was forcibly killed.
If the process has a signal handler installed does not fix the problem,
this message can rapidly spam the kernel log.

On my amd64 dev machine that does not have hugepages configured, I can
reproduce the repeated warnings easily by setting vm.nr_hugepages=2 (i.e.,
4 megabytes of huge pages) and running something that sets a signal
handler and forks, like

  #include <sys/mman.h>
  #include <signal.h>
  #include <stdlib.h>
  #include <unistd.h>

  sig_atomic_t counter = 10;
  void handler(int signal)
  {
      if (counter-- == 0)
         exit(0);
  }

  int main(void)
  {
      int status;
      char *addr = mmap(NULL, 4 * 1048576, PROT_READ | PROT_WRITE,
              MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
      if (addr == MAP_FAILED) {perror("mmap"); return 1;}
      *addr = 'x';
      switch (fork()) {
         case -1:
            perror("fork"); return 1;
         case 0:
            signal(SIGBUS, handler);
            *addr = 'x';
            break;
         default:
            *addr = 'x';
            wait(&status);
            if (WIFSIGNALED(status)) {
               psignal(WTERMSIG(status), "child");
            }
            break;
      }
  }
Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'for-v4.5-rc/omap-critical-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into fixes

ARM: OMAP2+: critical DRA7xx fix for v4.5-rc

Force the DRA7xx Ethernet internal clock source to stay enabled
per TI erratum i877:

http://www.ti.com/lit/er/sprz429h/sprz429h.pdf

Otherwise, if the Ethernet internal clock source is disabled, the
chip will age prematurely, and the RGMII I/O timing will soon
fail to meet the delay time and skew specifications for 1000Mbps
Ethernet.

This fix should go in as soon as possible.

Basic build, boot, and PM test results are available here:

http://www.pwsan.com/omap/testlogs/omap-critical-fixes-for-v4.5-rc/20160307014209/

* tag 'for-v4.5-rc/omap-critical-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending:
  ARM: dts: dra7: do not gate cpsw clock due to errata i877
  ARM: OMAP2+: hwmod: Introduce ti,no-idle dt property
Signed-off-by: Olof Johansson <olof@lixom.net>