git.monstr.eu Git - linux-2.6-microblaze.git/log

Merge remote-tracking branch 'regulator/fix/axp20x' into regulator-linus

Merge remote-tracking branch 'regulator/fix/core' into regulator-linus

Linux 4.3-rc4

Merge branch 'strscpy' of git://git./linux/kernel/git/cmetcalf/linux-tile

Pull strscpy string copy function implementation from Chris Metcalf.

Chris sent this during the merge window, but I waffled back and forth on
the pull request, which is why it's going in only now.

The new "strscpy()" function is definitely easier to use and more secure
than either strncpy() or strlcpy(), both of which are horrible nasty
interfaces that have serious and irredeemable problems.

strncpy() has a useless return value, and doesn't NUL-terminate an
overlong result.  To make matters worse, it pads a short result with
zeroes, which is a performance disaster if you have big buffers.

strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking
the insane NUL padding, but having a differently broken return value
which returns the original length of the source string.  Which means
that it will read characters past the count from the source buffer, and
you have to trust the source to be properly terminated.  It also makes
error handling fragile, since the test for overflow is unnecessarily
subtle.

strscpy() avoids both these problems, guaranteeing the NUL termination
(but not excessive padding) if the destination size wasn't zero, and
making the overflow condition very obvious by returning -E2BIG.  It also
doesn't read past the size of the source, and can thus be used for
untrusted source data too.

So why did I waffle about this for so long?

Every time we introduce a new-and-improved interface, people start doing
these interminable series of trivial conversion patches.

And every time that happens, somebody does some silly mistake, and the
conversion patch to the improved interface actually makes things worse.
Because the patch is mindnumbing and trivial, nobody has the attention
span to look at it carefully, and it's usually done over large swatches
of source code which means that not every conversion gets tested.

So I'm pulling the strscpy() support because it *is* a better interface.
But I will refuse to pull mindless conversion patches.  Use this in
places where it makes sense, but don't do trivial patches to fix things
that aren't actually known to be broken.

* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile: use global strscpy() rather than private copy
  string: provide strscpy()
  Make asm/word-at-a-time.h available on all architectures

Merge tag 'md/4.3-fixes' of git://neil.brown.name/md

Pull md fixes from Neil Brown:
"Assorted fixes for md in 4.3-rc.

  Two tagged for -stable, and one is really a cleanup to match and
  improve kmemcache interface.

* tag 'md/4.3-fixes' of git://neil.brown.name/md:
  md/bitmap: don't pass -1 to bitmap_storage_alloc.
  md/raid1: Avoid raid1 resync getting stuck
  md: drop null test before destroy functions
  md: clear CHANGE_PENDING in readonly array
  md/raid0: apply base queue limits *before* disk_stack_limits
  md/raid5: don't index beyond end of array in need_this_block().
  raid5: update analysis state for failed stripe
  md: wait for pending superblock updates before switching to read-only

Merge branch 'upstream' of git://git.linux-mips.org/ralf/upstream-linus

Pull MIPS updates from Ralf Baechle:
"This week's round of MIPS fixes:
   - Fix JZ4740 build
   - Fix fallback to GFP_DMA
   - FP seccomp in case of ENOSYS
   - Fix bootmem panic
   - A number of FP and CPS fixes
   - Wire up new syscalls
   - Make sure BPF assembler objects can properly be disassembled
   - Fix BPF assembler code for MIPS I"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: scall: Always run the seccomp syscall filters
  MIPS: Octeon: Fix kernel panic on startup from memory corruption
  MIPS: Fix R2300 FP context switch handling
  MIPS: Fix octeon FP context switch handling
  MIPS: BPF: Fix load delay slots.
  MIPS: BPF: Do all exports of symbols with FEXPORT().
  MIPS: Fix the build on jz4740 after removing the custom gpio.h
  MIPS: CPS: #ifdef on CONFIG_MIPS_MT_SMP rather than CONFIG_MIPS_MT
  MIPS: CPS: Don't include MT code in non-MT kernels.
  MIPS: CPS: Stop dangling delay slot from has_mt.
  MIPS: dma-default: Fix 32-bit fall back to GFP_DMA
  MIPS: Wire up userfaultfd and membarrier syscalls.

Merge branch 'irq-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
"This update contains:

   - Fix for a long standing race affecting /proc/irq/NNN

   - One line fix for ARM GICV3-ITS counting the wrong data

   - Warning silencing in ARM GICV3-ITS.  Another GCC trying to be
     overly clever issue"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Count additional LPIs for the aliased devices
  irqchip/gic-v3-its: Silence warning when its_lpi_alloc_chunks gets inlined
  genirq: Fix race in register_irq_proc()

MIPS: scall: Always run the seccomp syscall filters

The MIPS syscall handler code used to return -ENOSYS on invalid
syscalls. Whilst this is expected, it caused problems for seccomp
filters because the said filters never had the change to run since
the code returned -ENOSYS before triggering them. This caused
problems on the chromium testsuite for filters looking for invalid
syscalls. This has now changed and the seccomp filters are always
run even if the syscall is invalid. We return -ENOSYS once we
return from the seccomp filters. Moreover, similar codepaths have
been merged in the process which simplifies somewhat the overall
syscall code.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11236/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Merge branch 'x86-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
"Fixes all around the map: W+X kernel mapping fix, WCHAN fixes, two
  build failure fixes for corner case configs, x32 header fix and a
  speling fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds
  x86/mm: Set NX on gap between __ex_table and rodata
  x86/kexec: Fix kexec crash in syscall kexec_file_load()
  x86/process: Unify 32bit and 64bit implementations of get_wchan()
  x86/process: Add proper bound checks in 64bit get_wchan()
  x86, efi, kasan: Fix build failure on !KASAN && KMEMCHECK=y kernels
  x86/hyperv: Fix the build in the !CONFIG_KEXEC_CORE case
  x86/cpufeatures: Correct spelling of the HWP_NOTIFY flag

Merge branch 'timers-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull timer fixes from Ingo Molnar:
"An abs64() fix in the watchdog driver, and two clocksource driver
  NO_IRQ assumption fixes"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: Fix abs() usage w/ 64bit values
  clocksource/drivers/keystone: Fix bad NO_IRQ usage
  clocksource/drivers/rockchip: Fix bad NO_IRQ usage

Merge branch 'core-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull EFI fixes from Ingo Molnar:
"Two EFI fixes: one for x86, one for ARM, fixing a boot crash bug that
  can trigger under newer EFI firmware"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions
  x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down

Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
"Bunch of fixes all over the place, all pretty small: amdgpu, i915,
  exynos, one qxl and one vmwgfx.

  There is also a bunch of mst fixes, I left some cleanups in the series
  as I didn't think it was worth splitting up the tested series"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (37 commits)
  drm/dp/mst: add some defines for logical/physical ports
  drm/dp/mst: drop cancel work sync in the mstb destroy path (v2)
  drm/dp/mst: split connector registration into two parts (v2)
  drm/dp/mst: update the link_address_sent before sending the link address (v3)
  drm/dp/mst: fixup handling hotplug on port removal.
  drm/dp/mst: don't pass port into the path builder function
  drm/radeon: drop radeon_fb_helper_set_par
  drm: handle cursor_set2 in restore_fbdev_mode
  drm/exynos: Staticize local function in exynos_drm_gem.c
  drm/exynos: fimd: actually disable dp clock
  drm/exynos: dp: remove suspend/resume functions
  drm/qxl: recreate the primary surface when the bo is not primary
  drm/amdgpu: only print meaningful VM faults
  drm/amdgpu/cgs: remove import_gpu_mem
  drm/i915: Call non-locking version of drm_kms_helper_poll_enable(), v2
  drm: Add a non-locking version of drm_kms_helper_poll_enable(), v2
  drm/vmwgfx: Fix a command submission hang regression
  drm/exynos: remove unused mode_fixup() code
  drm/exynos: remove decon_mode_fixup()
  drm/exynos: remove fimd_mode_fixup()
  ...

Merge branch 'for-linus' of git://git./linux/kernel/git/dtor/input

Pull input layer fixes from Dmitry Torokhov:
"Fixes for two recent regressions (in Synaptics PS/2 and uinput
  drivers) and some more driver fixups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Revert "Input: synaptics - fix handling of disabling gesture mode"
  Input: psmouse - fix data race in __ps2_command
  Input: elan_i2c - add all valid ic type for i2c/smbus
  Input: zhenhua - ensure we have BITREVERSE
  Input: omap4-keypad - fix memory leak
  Input: serio - fix blocking of parport
  Input: uinput - fix crash when using ABS events
  Input: elan_i2c - expand maximum product_id form 0xFF to 0xFFFF
  Input: elan_i2c - add ic type 0x03
  Input: elan_i2c - don't require known iap version
  Input: imx6ul_tsc - fix controller name
  Input: imx6ul_tsc - use the preferred method for kzalloc()
  Input: imx6ul_tsc - check for negative return value
  Input: imx6ul_tsc - propagate the errors
  Input: walkera0701 - fix abs() calculations on 64 bit values
  Input: mms114 - remove unneded semicolons
  Input: pm8941-pwrkey - remove unneded semicolon
  Input: fix typo in MT documentation
  Input: cyapa - fix address of Gen3 devices in device tree documentation

clocksource: Fix abs() usage w/ 64bit values

This patch fixes one cases where abs() was being used with 64-bit
nanosecond values, where the result may be capped at 32-bits.

This potentially could cause watchdog false negatives on 32-bit
systems, so this patch addresses the issue by using abs64().

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1442279124-7309-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Merge tag 'arm64-fixes' of git://git./linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:

- Fix for transparent huge page change_protection() logic which was
   inadvertently changing a huge pmd page into a pmd table entry.

- Function graph tracer panic fix caused by the return_to_handler code
   corrupting the multi-regs function return value (composite types).

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: ftrace: fix function_graph tracer panic
  arm64: Fix THP protection change logic

Merge branch 'for-linus' of git://git./linux/kernel/git/geert/linux-m68k

Pull m68k updates from Geert Uytterhoeven:
"Summary:
   - Fix for accidental modification of arguments of syscall functions
   - Wire up new syscalls
   - Update defconfigs"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k/defconfig: Update defconfigs for v4.3-rc1
  m68k: Define asmlinkage_protect
  m68k: Wire up membarrier
  m68k: Wire up userfaultfd
  m68k: Wire up direct socket calls

irqchip/gic-v3-its: Count additional LPIs for the aliased devices

When configuring the interrupt mapping for a new device, we
iterate over all the possible aliases to account for their
maximum MSI allocation. This was introduced by e8137f4f5088
("irqchip: gicv3-its: Iterate over PCI aliases to generate ITS configuration").

Turns out that the code doing that is a bit braindead, and repeatedly
accounts for the same device over and over.

Fix this by counting the actual alias that is passed to us by the
core code.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1443800646-8074-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

irqchip/gic-v3-its: Silence warning when its_lpi_alloc_chunks gets inlined

More agressive inlining in recent versions of GCC have uncovered
a new set of warnings:

drivers/irqchip/irq-gic-v3-its.c: In function its_msi_prepare:
  drivers/irqchip/irq-gic-v3-its.c:1148:26: warning: lpi_base may be used
    uninitialized in this function [-Wmaybe-uninitialized]
     dev->event_map.lpi_base = lpi_base;
                          ^
drivers/irqchip/irq-gic-v3-its.c:1116:6: note: lpi_base was declared here
  int lpi_base;
      ^
drivers/irqchip/irq-gic-v3-its.c:1149:25: warning: nr_lpis may be used
  uninitialized in this function [-Wmaybe-uninitialized]
   dev->event_map.nr_lpis = nr_lpis;
                         ^
drivers/irqchip/irq-gic-v3-its.c:1117:6: note: nr_lpis was declared here
  int nr_lpis;
      ^
The warning is fairly benign (there is no code path that could
actually use uninitialized variables), but let's silence it anyway
by zeroing the variables on the error path.

Reported-by: Alex Shi <alex.shi@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1443800646-8074-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Merge tag 'dmaengine-fix-4.3-rc4' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine fixes from Vinod Koul:
"This contains fixes spread throughout the drivers, and also fixes one
  more instance of privatecnt in dmaengine.

  Driver fixes summary:
   - bunch of pxa_dma fixes for reuse of descriptor issue, residue and
     no-requestor
   - odd fixes in xgene, idma, sun4i and zxdma
   - at_xdmac fixes for cleaning descriptor and block addr mode"

* tag 'dmaengine-fix-4.3-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: pxa_dma: fix residue corner case
  dmaengine: pxa_dma: fix the no-requestor case
  dmaengine: zxdma: Fix off-by-one for testing valid pchan request
  dmaengine: at_xdmac: clean used descriptor
  dmaengine: at_xdmac: change block increment addressing mode
  dmaengine: dw: properly read DWC_PARAMS register
  dmaengine: xgene-dma: Fix overwritting DMA tx ring
  dmaengine: fix balance of privatecnt
  dmaengine: sun4i: fix unsafe list iteration
  dmaengine: idma64: improve residue estimation
  dmaengine: xgene-dma: fix handling xgene_dma_get_ring_size result
  dmaengine: pxa_dma: fix initial list move

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
"Another week, another round of fixes.

  These have been brewing for a bit and in various iterations, but I
  feel pretty comfortable about the quality of them.  They fix real
  issues.  The pull request is mostly blk-mq related, and the only one
  not fixing a real bug, is the tag iterator abstraction from Christoph.
  But it's pretty trivial, and we'll need it for another fix soon.

  Apart from the blk-mq fixes, there's an NVMe affinity fix from Keith,
  and a single fix for xen-blkback from Roger fixing failure to free
  requests on disconnect"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: factor out a helper to iterate all tags for a request_queue
  blk-mq: fix racy updates of rq->errors
  blk-mq: fix deadlock when reading cpu_list
  blk-mq: avoid inserting requests before establishing new mapping
  blk-mq: fix q->mq_usage_counter access race
  blk-mq: Fix use after of free q->mq_map
  blk-mq: fix sysfs registration/unregistration race
  blk-mq: avoid setting hctx->tags->cpumask before allocation
  NVMe: Set affinity after allocating request queues
  xen/blkback: free requests on disconnection

Revert "Input: synaptics - fix handling of disabling gesture mode"

This reverts commit e51e38494a8ecc18650efb0c840600637891de2c: we
actually do want the device to work in extended W mode, as this is the
mode that allows us receiving multiple contact information.

Cc: stable@vger.kernel.org

MIPS: Octeon: Fix kernel panic on startup from memory corruption

During development it was found that a number of builds would panic
during the kernel init process, more specifically in 'delayed_fput()'.
The panic showed the kernel trying to access a memory address of
'0xb7fdc00' while traversing the 'delayed_fput_list' structure.
Comparing this memory address to the value of the pointer used on
builds that did not panic confirmed that the pointer on crashing
builds must have been corrupted at some stage earlier in the init
process.

By traversing the list earlier and earlier in the code it was found
that 'plat_mem_setup()' was responsible for corrupting the list.
Specifically the line:

memory = cvmx_bootmem_phy_alloc(mem_alloc_size,
__pa_symbol(&__init_end), -1,
0x100000,
CVMX_BOOTMEM_FLAG_NO_LOCKING);

Which would eventually call:

cvmx_bootmem_phy_set_size(new_ent_addr,
cvmx_bootmem_phy_get_size
(ent_addr) -
(desired_min_addr -
ent_addr));

Where 'new_ent_addr'=0x4800000 (the address of 'delayed_fput_list')
and the second argument (size)=0xb7fdc00 (the address causing the
kernel panic). The job of this part of 'plat_mem_setup()' is to
allocate chunks of memory for the kernel to use. At the start of
each chunk of memory the size of the chunk is written, hence the
value 0xb7fdc00 is written onto memory at 0x4800000, therefore the
kernel panics when it goes back to access 'delayed_fput_list' later
on in the initialisation process.

On builds that were not crashing it was found that the compiler had
placed 'delayed_fput_list' at 0x4800008, meaning it wasn't corrupted
(but something else in memory was overwritten).

As can be seen in the first function call above the code begins to
allocate chunks of memory beginning from the symbol '__init_end'.
The MIPS linker script (vmlinux.lds.S) however defines the .bss
section to begin after '__init_end'. Therefore memory within the
.bss section is allocated to the kernel to use (System.map shows
'delayed_fput_list' and other kernel structures to be in .bss).

To stop the kernel panic (and the .bss section being corrupted)
memory should begin being allocated from the symbol '_end'.

Signed-off-by: Matt Bennett <matt.bennett@alliedtelesis.co.nz>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: aleksey.makarov@auriga.com
Patchwork: https://patchwork.linux-mips.org/patch/11251/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Fix R2300 FP context switch handling

Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed FP
context saving from the asm-written resume function in favour of reusing
existing code to perform the same task. However it only removed the FP
context saving code from the r4k_switch.S implementation of resume.
Remove it from the r2300_switch.S implementation too in order to prevent
attempting to save the FP context twice, which would likely lead to an
exception from the second save because the FPU had already been disabled
by the first save.

This patch has only been build tested, using rbtx49xx_defconfig.

Fixes: 1a3d59579b9f ("MIPS: Tidy up FPU context switching")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/11167/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Fix octeon FP context switch handling

Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed FP
context saving from the asm-written resume function in favour of reusing
existing code to perform the same task. However it only removed the FP
context saving code from the r4k_switch.S implementation of resume.
Octeon uses its own implementation in octeon_switch.S, so remove FP
context saving there too in order to prevent attempting to save context
twice. That formerly led to an exception from the second save as follows
because the FPU had already been disabled by the first save:

    do_cpu invoked from kernel context![#1]:
    CPU: 0 PID: 2 Comm: kthreadd Not tainted 4.3.0-rc2-dirty #2
    task: 800000041f84a008 ti: 800000041f864000 task.ti: 800000041f864000
    $ 0   : 0000000000000000 0000000010008ce1 0000000000100000 ffffffffbfffffff
    $ 4   : 800000041f84a008 800000041f84ac08 800000041f84c000 0000000000000004
    $ 8   : 0000000000000001 0000000000000000 0000000000000000 0000000000000001
    $12   : 0000000010008ce3 0000000000119c60 0000000000000036 800000041f864000
    $16   : 800000041f84ac08 800000000792ce80 800000041f84a008 ffffffff81758b00
    $20   : 0000000000000000 ffffffff8175ae50 0000000000000000 ffffffff8176c740
    $24   : 0000000000000006 ffffffff81170300
    $28   : 800000041f864000 800000041f867d90 0000000000000000 ffffffff815f3fa0
    Hi    : 0000000000fa8257
    Lo    : ffffffffe15cfc00
    epc   : ffffffff8112821c resume+0x9c/0x200
    ra    : ffffffff815f3fa0 __schedule+0x3f0/0x7d8
    Status: 10008ce2        KX SX UX KERNEL EXL
    Cause : 1080002c (ExcCode 0b)
    PrId  : 000d0601 (Cavium Octeon+)
    Modules linked in:
    Process kthreadd (pid: 2, threadinfo=800000041f864000, task=800000041f84a008, tls=0000000000000000)
    Stack : ffffffff81604218 ffffffff815f7e08 800000041f84a008 ffffffff811681b0
              800000041f84a008 ffffffff817e9878 0000000000000000 ffffffff81770000
              ffffffff81768340 ffffffff81161398 0000000000000001 0000000000000000
              0000000000000000 ffffffff815f4424 0000000000000000 ffffffff81161d68
              ffffffff81161be8 0000000000000000 0000000000000000 0000000000000000
              0000000000000000 0000000000000000 0000000000000000 ffffffff8111e16c
              0000000000000000 0000000000000000 0000000000000000 0000000000000000
              0000000000000000 0000000000000000 0000000000000000 0000000000000000
              0000000000000000 0000000000000000 0000000000000000 0000000000000000
              0000000000000000 0000000000000000 0000000000000000 0000000000000000
              ...
    Call Trace:
    [<ffffffff8112821c>] resume+0x9c/0x200
    [<ffffffff815f3fa0>] __schedule+0x3f0/0x7d8
    [<ffffffff815f4424>] schedule+0x34/0x98
    [<ffffffff81161d68>] kthreadd+0x180/0x198
    [<ffffffff8111e16c>] ret_from_kernel_thread+0x14/0x1c

Tested using cavium_octeon_defconfig on an EdgeRouter Lite.

Fixes: 1a3d59579b9f ("MIPS: Tidy up FPU context switching")
Reported-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Aleksey Makarov <aleksey.makarov@auriga.com>
Cc: linux-kernel@vger.kernel.org
Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Leonid Rosenboim <lrosenboim@caviumnetworks.com>
Patchwork: https://patchwork.linux-mips.org/patch/11166/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Merge tag 'mmc-v4.3-rc3' of git://git.linaro.org/people/ulf.hansson/mmc

Pull MMC fixes from Ulf Hansson:
"Here are some mmc fixes intended for v4.3 rc4:

  MMC core:
   - Allow users of mmc_of_parse() to succeed when CONFIG_GPIOLIB is
     unset
   - Prevent infinite loop of re-tuning for CRC-errors for CMD19 and
     CMD21

   MMC host:
   - pxamci: Fix issues with card detect
   - sunxi: Fix clk-delay settings"

* tag 'mmc-v4.3-rc3' of git://git.linaro.org/people/ulf.hansson/mmc:
  mmc: core: fix dead loop of mmc_retune
  mmc: pxamci: fix card detect with slot-gpio API
  mmc: sunxi: Fix clk-delay settings
  mmc: core: Don't return an error for CD/WP GPIOs when GPIOLIB is unset

Merge git://git.infradead.org/intel-iommu

Pull IOVA fixes from David Woodhouse:
"The main fix here is the first one, fixing the over-allocation of
   size-aligned requests.  The other patches simply make the existing
  IOVA code available to users other than the Intel VT-d driver, with no
  functional change.

  I concede the latter really *should* have been submitted during the
  merge window, but since it's basically risk-free and people are
  waiting to build on top of it and it's my fault I didn't get it in, I
  (and they) would be grateful if you'd take it"

* git://git.infradead.org/intel-iommu:
  iommu: Make the iova library a module
  iommu: iova: Export symbols
  iommu: iova: Move iova cache management to the iova library
  iommu/iova: Avoid over-allocating when size-aligned

arm64: ftrace: fix function_graph tracer panic

When function graph tracer is enabled, the following operation
will trigger panic:

mount -t debugfs nodev /sys/kernel
echo next_tgid > /sys/kernel/tracing/set_ftrace_filter
echo function_graph > /sys/kernel/tracing/current_tracer
ls /proc/

------------[ cut here ]------------
[  198.501417] Unable to handle kernel paging request at virtual address cb88537fdc8ba316
[  198.506126] pgd = ffffffc008f79000
[  198.509363] [cb88537fdc8ba316] *pgd=00000000488c6003, *pud=00000000488c6003, *pmd=0000000000000000
[  198.517726] Internal error: Oops: 94000005 [#1] SMP
[  198.518798] Modules linked in:
[  198.520582] CPU: 1 PID: 1388 Comm: ls Tainted: G
[  198.521800] Hardware name: linux,dummy-virt (DT)
[  198.522852] task: ffffffc0fa9e8000 ti: ffffffc0f9ab0000 task.ti: ffffffc0f9ab0000
[  198.524306] PC is at next_tgid+0x30/0x100
[  198.525205] LR is at return_to_handler+0x0/0x20
[  198.526090] pc : [<ffffffc0002a1070>] lr : [<ffffffc0000907c0>] pstate: 60000145
[  198.527392] sp : ffffffc0f9ab3d40
[  198.528084] x29: ffffffc0f9ab3d40 x28: ffffffc0f9ab0000
[  198.529406] x27: ffffffc000d6a000 x26: ffffffc000b786e8
[  198.530659] x25: ffffffc0002a1900 x24: ffffffc0faf16c00
[  198.531942] x23: ffffffc0f9ab3ea0 x22: 0000000000000002
[  198.533202] x21: ffffffc000d85050 x20: 0000000000000002
[  198.534446] x19: 0000000000000002 x18: 0000000000000000
[  198.535719] x17: 000000000049fa08 x16: ffffffc000242efc
[  198.537030] x15: 0000007fa472b54c x14: ffffffffff000000
[  198.538347] x13: ffffffc0fada84a0 x12: 0000000000000001
[  198.539634] x11: ffffffc0f9ab3d70 x10: ffffffc0f9ab3d70
[  198.540915] x9 : ffffffc0000907c0 x8 : ffffffc0f9ab3d40
[  198.542215] x7 : 0000002e330f08f0 x6 : 0000000000000015
[  198.543508] x5 : 0000000000000f08 x4 : ffffffc0f9835ec0
[  198.544792] x3 : cb88537fdc8ba316 x2 : cb88537fdc8ba306
[  198.546108] x1 : 0000000000000002 x0 : ffffffc000d85050
[  198.547432]
[  198.547920] Process ls (pid: 1388, stack limit = 0xffffffc0f9ab0020)
[  198.549170] Stack: (0xffffffc0f9ab3d40 to 0xffffffc0f9ab4000)
[  198.582568] Call trace:
[  198.583313] [<ffffffc0002a1070>] next_tgid+0x30/0x100
[  198.584359] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
[  198.585503] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
[  198.586574] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
[  198.587660] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70
[  198.588896] Code: aa0003f5 2a0103f4 b4000102 91004043 (885f7c60)
[  198.591092] ---[ end trace 6a346f8f20949ac8 ]---

This is because when using function graph tracer, if the traced
function return value is in multi regs ([x0-x7]), return_to_handler
may corrupt them. So in return_to_handler, the parameter regs should
be protected properly.

Cc: <stable@vger.kernel.org> # 3.18+
Signed-off-by: Li Bin <huawei.libin@huawei.com>
Acked-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

MIPS: BPF: Fix load delay slots.

The entire bpf_jit_asm.S is written in noreorder mode because "we know
better" according to a comment. This also prevented the assembler from
throwing in the required NOPs for MIPS I processors which have no
load-use interlock, thus the load's consumer might end up using the
old value of the register from prior to the load.

Fixed by putting the assembler in reorder mode for just the affected
load instructions. This is not enough for gas to actually try to be
clever by looking at the next instruction and inserting a nop only
when needed but as the comment said "we know better", so getting gas
to unconditionally emit a NOP is just right in this case and prevents
adding further ifdefery.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds

On x32, gcc predefines __x86_64__ but long is only 32-bit.  Use
__ILP32__ to distinguish x32.

Fixes this compiler error in perf:

tools/include/asm-generic/bitops/__ffs.h: In function '__ffs':
tools/include/asm-generic/bitops/__ffs.h:19:8: error: right shift count >= width of type [-Werror=shift-count-overflow]
  word >>= 32;
       ^

This isn't sufficient to build perf for x32, though.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443660043.2730.15.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

md/bitmap: don't pass -1 to bitmap_storage_alloc.

Passing -1 to bitmap_storage_alloc() causes page->index to be set to
-1, which is quite problematic.

So only pass ->cluster_slot if mddev_is_clustered().

Fixes: b97e92574c0b ("Use separate bitmaps for each nodes in the cluster")
Cc: stable@vger.kernel.org (v4.1+)
Signed-off-by: NeilBrown <neilb@suse.com>

md/raid1: Avoid raid1 resync getting stuck

close_sync() needs to set conf->next_resync to a large, but safe value
below MaxSector and use it to determine whether or not to set
start_next_window in wait_barrier()

Solution suggested by Neil Brown.

Reported-by: Nate Dailey <nate.dailey@stratus.com>
Tested-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>

md: drop null test before destroy functions

Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ expression x; @@
-if (x != NULL)
$kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy$(x);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NeilBrown <neilb@suse.com>

md: clear CHANGE_PENDING in readonly array

If faulty disks of an array are more than allowed degraded number, the
array enters error handling. It will be marked as read-only with
MD_CHANGE_PENDING/RECOVERY_NEEDED set. But currently recovery doesn't
clear CHANGE_PENDING bit for read-only array. If MD_CHANGE_PENDING is
set for a raid5 array, all returned IO will be hold on a list till the
bit is clear. But recovery nevery clears this bit, the IO is always in
pending state and nevery finish. This has bad effects like upper layer
can't get an IO error and the array can't be stopped.

Fixes: c3cce6cda162 ("md/raid5: ensure device failure recorded before write request returns.")
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>

md/raid0: apply base queue limits *before* disk_stack_limits

Calling e.g. blk_queue_max_hw_sectors() after calls to
disk_stack_limits() discards the settings determined by
disk_stack_limits().
So we need to make those calls first.

Fixes: 199dc6ed5179 ("md/raid0: update queue parameter in a safer location.")
Cc: stable@vger.kernel.org (v2.6.35+ - please apply with 199dc6ed5179).
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>

md/raid5: don't index beyond end of array in need_this_block().

When need_this_block probably shouldn't be called when there
are more than 2 failed devices, we really don't want it to try
indexing beyond the end of the failed_num[] of fdev[] arrays.

So limit the loops to at most 2 iterations.

Reported-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.de>

raid5: update analysis state for failed stripe

handle_failed_stripe() makes the stripe fail, eg, all IO will return
with a failure, but it doesn't update stripe_head_state. Later
handle_stripe() has special handling for raid6 for handle_stripe_fill().
That check before handle_stripe_fill() doesn't skip the failed stripe
and we get a kernel crash in need_this_block. This patch clear the
analysis state to make sure no functions wrongly called after
handle_failed_stripe()

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>

md: wait for pending superblock updates before switching to read-only

If a superblock update is pending, wait for it to complete before
letting md_set_readonly() switch to readonly.
Otherwise we might lose important information about a device having
failed.

For external arrays, waiting for superblock updates can wait on
user-space, so in that case, just return an error.

Reported-and-tested-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>

x86/mm: Set NX on gap between __ex_table and rodata

Unused space between the end of __ex_table and the start of
rodata can be left W+x in the kernel page tables.  Extend the
setting of the NX bit to cover this gap by starting from
text_end rather than rodata_start.

  Before:
  ---[ High Kernel Mapping ]---
  0xffffffff80000000-0xffffffff81000000          16M                               pmd
  0xffffffff81000000-0xffffffff81600000           6M     ro         PSE     GLB x  pmd
  0xffffffff81600000-0xffffffff81754000        1360K     ro                 GLB x  pte
  0xffffffff81754000-0xffffffff81800000         688K     RW                 GLB x  pte
  0xffffffff81800000-0xffffffff81a00000           2M     ro         PSE     GLB NX pmd
  0xffffffff81a00000-0xffffffff81b3b000        1260K     ro                 GLB NX pte
  0xffffffff81b3b000-0xffffffff82000000        4884K     RW                 GLB NX pte
  0xffffffff82000000-0xffffffff82200000           2M     RW         PSE     GLB NX pmd
  0xffffffff82200000-0xffffffffa0000000         478M                               pmd

  After:
  ---[ High Kernel Mapping ]---
  0xffffffff80000000-0xffffffff81000000          16M                               pmd
  0xffffffff81000000-0xffffffff81600000           6M     ro         PSE     GLB x  pmd
  0xffffffff81600000-0xffffffff81754000        1360K     ro                 GLB x  pte
  0xffffffff81754000-0xffffffff81800000         688K     RW                 GLB NX pte
  0xffffffff81800000-0xffffffff81a00000           2M     ro         PSE     GLB NX pmd
  0xffffffff81a00000-0xffffffff81b3b000        1260K     ro                 GLB NX pte
  0xffffffff81b3b000-0xffffffff82000000        4884K     RW                 GLB NX pte
  0xffffffff82000000-0xffffffff82200000           2M     RW         PSE     GLB NX pmd
  0xffffffff82200000-0xffffffffa0000000         478M                               pmd

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.gov
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/kexec: Fix kexec crash in syscall kexec_file_load()

The original bug is a page fault crash that sometimes happens
on big machines when preparing ELF headers:

    BUG: unable to handle kernel paging request at ffffc90613fc9000
    IP: [<ffffffff8103d645>] prepare_elf64_ram_headers_callback+0x165/0x260

The bug is caused by us under-counting the number of memory ranges
and subsequently not allocating enough ELF header space for them.
The bug is typically masked on smaller systems, because the ELF header
allocation is rounded up to the next page.

This patch modifies the code in fill_up_crash_elf_data() by using
walk_system_ram_res() instead of walk_system_ram_range() to correctly
count the max number of crash memory ranges. That's because the
walk_system_ram_range() filters out small memory regions that
reside in the same page, but walk_system_ram_res() does not.

Here's how I found the bug:

After tracing prepare_elf64_headers() and prepare_elf64_ram_headers_callback(),
the code uses walk_system_ram_res() to fill-in crash memory regions information
to the program header, so it counts those small memory regions that
reside in a page area.

But, when the kernel was using walk_system_ram_range() in
fill_up_crash_elf_data() to count the number of crash memory regions,
it filters out small regions.

I printed those small memory regions, for example:

  kexec: Get nr_ram ranges. vaddr=0xffff880077592258 paddr=0x77592258, sz=0xdc0

Based on the code in walk_system_ram_range(), this memory region
will be filtered out:

  pfn = (0x77592258 + 0x1000 - 1) >> 12 = 0x77593
  end_pfn = (0x77592258 + 0xfc0 -1 + 1) >> 12 = 0x77593
  end_pfn - pfn = 0x77593 - 0x77593 = 0  <=== if (end_pfn > pfn) is FALSE

So, the max_nr_ranges that's counted by the kernel doesn't include
small memory regions - causing us to under-allocate the required space.
That causes the page fault crash that happens in a later code path
when preparing ELF headers.

This bug is not easy to reproduce on small machines that have few
CPUs, because the allocated page aligned ELF buffer has more free
space to cover those small memory regions' PT_LOAD headers.

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: kexec@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1443531537-29436-1-git-send-email-jlee@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

drm/dp/mst: add some defines for logical/physical ports

This just removes the magic number.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/dp/mst: drop cancel work sync in the mstb destroy path (v2)

Since 9eb1e57f564d4e6e10991402726cc83fe0b9172f
drm/dp/mst: make sure mst_primary mstb is valid in work function

we validate the mstb structs in the work function, and doing
that takes a reference. So we should never get here with the
work function running using the mstb device, only if the work
function hasn't run yet or is running for another mstb.

So we don't need to sync the work here, this was causing
lockdep spew as below.

[  +0.000160] =============================================
[  +0.000001] [ INFO: possible recursive locking detected ]
[  +0.000002] 3.10.0-320.el7.rhel72.stable.backport.3.x86_64.debug #1 Tainted: G        W      ------------
[  +0.000001] ---------------------------------------------
[  +0.000001] kworker/4:2/1262 is trying to acquire lock:
[  +0.000001]  ((&mgr->work)){+.+.+.}, at: [<ffffffff810b29a5>] flush_work+0x5/0x2e0
[  +0.000007]
but task is already holding lock:
[  +0.000001]  ((&mgr->work)){+.+.+.}, at: [<ffffffff810b57e4>] process_one_work+0x1b4/0x710
[  +0.000004]
other info that might help us debug this:
[  +0.000001]  Possible unsafe locking scenario:

[  +0.000002]        CPU0
[  +0.000000]        ----
[  +0.000001]   lock((&mgr->work));
[  +0.000002]   lock((&mgr->work));
[  +0.000001]
*** DEADLOCK ***

[  +0.000001]  May be due to missing lock nesting notation

[  +0.000002] 2 locks held by kworker/4:2/1262:
[  +0.000001]  #0:  (events_long){.+.+.+}, at: [<ffffffff810b57e4>] process_one_work+0x1b4/0x710
[  +0.000004]  #1:  ((&mgr->work)){+.+.+.}, at: [<ffffffff810b57e4>] process_one_work+0x1b4/0x710
[  +0.000003]
stack backtrace:
[  +0.000003] CPU: 4 PID: 1262 Comm: kworker/4:2 Tainted: G        W      ------------   3.10.0-320.el7.rhel72.stable.backport.3.x86_64.debug #1
[  +0.000001] Hardware name: LENOVO 20EGS0R600/20EGS0R600, BIOS GNET71WW (2.19 ) 02/05/2015
[  +0.000008] Workqueue: events_long drm_dp_mst_link_probe_work [drm_kms_helper]
[  +0.000001]  ffffffff82c26c90 00000000a527b914 ffff88046399bae8 ffffffff816fe04d
[  +0.000004]  ffff88046399bb58 ffffffff8110f47f ffff880461438000 0001009b840fc003
[  +0.000002]  ffff880461438a98 0000000000000000 0000000804dc26e1 ffffffff824a2c00
[  +0.000003] Call Trace:
[  +0.000004]  [<ffffffff816fe04d>] dump_stack+0x19/0x1b
[  +0.000004]  [<ffffffff8110f47f>] __lock_acquire+0x115f/0x1250
[  +0.000002]  [<ffffffff8110fd49>] lock_acquire+0x99/0x1e0
[  +0.000002]  [<ffffffff810b29a5>] ? flush_work+0x5/0x2e0
[  +0.000002]  [<ffffffff810b29ee>] flush_work+0x4e/0x2e0
[  +0.000002]  [<ffffffff810b29a5>] ? flush_work+0x5/0x2e0
[  +0.000004]  [<ffffffff81025905>] ? native_sched_clock+0x35/0x80
[  +0.000002]  [<ffffffff81025959>] ? sched_clock+0x9/0x10
[  +0.000002]  [<ffffffff810da1f5>] ? local_clock+0x25/0x30
[  +0.000002]  [<ffffffff8110dca9>] ? mark_held_locks+0xb9/0x140
[  +0.000003]  [<ffffffff810b4ed5>] ? __cancel_work_timer+0x95/0x160
[  +0.000002]  [<ffffffff810b4ee8>] __cancel_work_timer+0xa8/0x160
[  +0.000002]  [<ffffffff810b4fb0>] cancel_work_sync+0x10/0x20
[  +0.000007]  [<ffffffffa0160d17>] drm_dp_destroy_mst_branch_device+0x27/0x120 [drm_kms_helper]
[  +0.000006]  [<ffffffffa0163968>] drm_dp_mst_link_probe_work+0x78/0xa0 [drm_kms_helper]
[  +0.000002]  [<ffffffff810b5850>] process_one_work+0x220/0x710
[  +0.000002]  [<ffffffff810b57e4>] ? process_one_work+0x1b4/0x710
[  +0.000005]  [<ffffffff810b5e5b>] worker_thread+0x11b/0x3a0
[  +0.000003]  [<ffffffff810b5d40>] ? process_one_work+0x710/0x710
[  +0.000002]  [<ffffffff810beced>] kthread+0xed/0x100
[  +0.000003]  [<ffffffff810bec00>] ? insert_kthread_work+0x80/0x80
[  +0.000003]  [<ffffffff817121d8>] ret_from_fork+0x58/0x90

v2: add flush_work.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/dp/mst: split connector registration into two parts (v2)

In order to cache the EDID properly for tiled displays, we
need to retrieve it before we register the connector with
userspace, otherwise userspace can call get resources
and try and get the edid before we've even cached it.

This fixes some problems when hotplugging mst monitors,
with X/mutter running. As mutter seems to get 0 modes
for one of the monitors in the tile.

v2: fix warning in radeon
handle tile setting in cached path rather than
get edid path.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/dp/mst: update the link_address_sent before sending the link address (v3)

Update the state before sending the msg to close it.

v2: reset value if return indicates we haven't send the msg.
v3: just clean the code up.
Pointed out by Adam J Richter on

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91481

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/dp/mst: fixup handling hotplug on port removal.

output ports should always have a connector, unless
in the rare case connector allocation fails in the
driver.

In this case we only need to teardown the pdt,
and free the struct, and there is no need to
send a hotplug msg.

In the case were we add the port to the destroy
list we need to send a hotplug if we destroy
any connectors, so userspace knows to reprobe
stuff.

this patch also handles port->connector allocation
failing which should be a rare event, but makes
the code consistent.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/dp/mst: don't pass port into the path builder function

This is unnecessary and it makes it easier to see what is needed
from port.

also add blank line to make things nicer.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm/radeon: drop radeon_fb_helper_set_par

It was just a wrapper around drm_fb_helper_set_par that
called cursor_set2 in addition. Now that the core handles
this, drop this radeon specific version.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drm: handle cursor_set2 in restore_fbdev_mode

If a driver uses the cursor_set2 crtc callback rather than
cursor_set, use that. This fixes the fbdev helper for drivers
that use cursor_set2.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
"12 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  dmapool: fix overflow condition in pool_find_page()
  thermal: avoid division by zero in power allocator
  memcg: remove pcp_counter_lock
  kprobes: use _do_fork() in samples to make them work again
  drivers/input/joystick/Kconfig: zhenhua.c needs BITREVERSE
  memcg: make mem_cgroup_read_stat() unsigned
  memcg: fix dirty page migration
  dax: fix NULL pointer in __dax_pmd_fault()
  mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault
  mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)
  userfaultfd: remove kernel header include from uapi header
  arch/x86/include/asm/efi.h: fix build failure

Merge tag 'pm+acpi-4.3-rc4' of git://git./linux/kernel/git/rafael/linux-pm

Pull power management and ACPI fixes from Rafael Wysocki:
"These are fixes mostly, for a few changes made in this cycle (the
  intel_idle driver, the OPP library, the ACPI EC driver, turbostat) and
  for some issues that have just been discovered (ACPI PCI IRQ
  management, PCI power management documentation, turbostat), with a
  couple of cleanups on top of them.

  Specifics:

   - intel_idle driver fixup for the recently added Skylake chips
     support (Len Brown).

   - Operating Performance Points (OPP) library fix related to the
     recently added support for new DT bindings and a fix for a typo in
     a comment (Viresh Kumar, Stephen Boyd).

   - ACPI EC driver fix for a recently introduced memory leak in an
     error code path (Lv Zheng).

   - ACPI PCI IRQ management fix for the issue where an ISA IRQ is
     shared with a PCI device which requires it to be configured in a
     different way and may cause an interrupt storm to happen as a
     result with an extra ACPI SCI IRQ handling simplification on top of
     it (Jiang Liu).

   - Update of the PCI power management documentation that became
     outdated and started to actively confuse the readers to make it
     actually reflect the code (Rafael J Wysocki).

   - turbostat fixes including an IVB Xeon regression fix (related to
     the --debug command line option), Skylake adjustment for the TSC
     running at a frequency that doesn't match the base one exactly, and
     a Knights Landing quirk to account for the fact that it only
     updates APERF and MPERF every 1024 clock cycles plus bumping up the
     turbostat version number (Len Brown, Hubert Chrzaniuk)"

* tag 'pm+acpi-4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  tools/power turbosat: update version number
  tools/power turbostat: SKL: Adjust for TSC difference from base frequency
  tools/power turbostat: KNL workaround for %Busy and Avg_MHz
  tools/power turbostat: IVB Xeon: fix --debug regression
  ACPI / PCI: Remove duplicated penalty on SCI IRQ
  ACPI, PCI, irq: Do not share PCI IRQ with ISA IRQ
  ACPI / EC: Fix a memory leak issue in acpi_ec_query()
  PM / OPP: Fix typo modifcation -> modification
  PCI / PM: Update runtime PM documentation for PCI devices
  PM / OPP: of_property_count_u32_elems() can return errors
  intel_idle: Skylake Client Support - updated

Merge git://git./linux/kernel/git/davem/net

Pull networking fixes from David Miller:

1) Fix regression in SKB partial checksum handling, from Pravin B
   Shalar.

2) Fix VLAN inside of VXLAN handling in i40e driver, from Jesse
   Brandeburg.

3) Cure softlockups during accept() in SCTP, from Karl Heiss.

4) MSG_PEEK should return multiple SKBs worth of data in AF_UNIX, from
   Aaron Conole.

5) IPV6 erroneously ignores output interface specifier in lookup key for
   route lookups, fix from David Ahern.

6) In Marvell DSA driver, forward unknown frames to CPU port, from
   Andrew Lunn.

7) Mission flow flag initializations in some code paths, from David
   Ahern.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: Initialize flow flags in input path
  net: dsa: fix preparation of a port STP update
  testptp: Silence compiler warnings on ppc64
  net/mlx4: Handle return codes in mlx4_qp_attach_common
  dsa: mv88e6xxx: Enable forwarding for unknown to the CPU port
  skbuff: Fix skb checksum partial check.
  net: ipv6: Add RT6_LOOKUP_F_IFACE flag if oif is set
  net sysfs: Print link speed as signed integer
  bna: fix error handling
  af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag
  af_unix: Convert the unix_sk macro to an inline function for type safety
  net: sctp: Don't use 64 kilobyte lookup table for four elements
  l2tp: protect tunnel->del_work by ref_count
  net/ibm/emac: bump version numbers for correct work with ethtool
  sctp: Prevent soft lockup when sctp_accept() is called during a timeout event
  sctp: Whitespace fix
  i40e/i40evf: check for stopped admin queue
  i40e: fix VLAN inside VXLAN
  r8169: fix handling rtl_readphy result
  net: hisilicon: fix handling platform_get_irq result

dmapool: fix overflow condition in pool_find_page()

If a DMA pool lies at the very top of the dma_addr_t range (as may
happen with an IOMMU involved), the calculated end address of the pool
wraps around to zero, and page lookup always fails.

Tweak the relevant calculation to be overflow-proof.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

thermal: avoid division by zero in power allocator

During boot I get a div by zero Oops regression starting in v4.3-rc3.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Javi Merino <javi.merino@arm.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: remove pcp_counter_lock

Commit 733a572e66d2 ("memcg: make mem_cgroup_read_{stat|event}() iterate
possible cpus instead of online") removed the last use of the per memcg
pcp_counter_lock but forgot to remove the variable.

Kill the vestigial variable.

Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kprobes: use _do_fork() in samples to make them work again

Commit 3033f14ab78c ("clone: support passing tls argument via C rather
than pt_regs magic") introduced _do_fork() that allowed to pass @tls
parameter.

The old do_fork() is defined only for architectures that are not ready
to use this way and do not define HAVE_COPY_THREAD_TLS.

Let's use _do_fork() in the kprobe examples to make them work again on
all architectures.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thiago Macieira <thiago.macieira@intel.com>
Cc: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/input/joystick/Kconfig: zhenhua.c needs BITREVERSE

It uses bitrev8(), so it must ensure that lib/bitrev.o gets included in
vmlinux.

Cc: Fengguang Wu <fengguang.wu@gmail.com>
Cc: yalin wang <yalin.wang2010@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: make mem_cgroup_read_stat() unsigned

mem_cgroup_read_stat() returns a page count by summing per cpu page
counters.  The summing is racy wrt.  updates, so a transient negative
sum is possible.  Callers don't want negative values:

- mem_cgroup_wb_stats() doesn't want negative nr_dirty or nr_writeback.
   This could confuse dirty throttling.

- oom reports and memory.stat shouldn't show confusing negative usage.

- tree_usage() already avoids negatives.

Avoid returning negative page counts from mem_cgroup_read_stat() and
convert it to unsigned.

[akpm@linux-foundation.org: fix old typo while we're in there]
Signed-off-by: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org> [4.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: fix dirty page migration

The problem starts with a file backed dirty page which is charged to a
memcg.  Then page migration is used to move oldpage to newpage.

Migration:
- copies the oldpage's data to newpage
- clears oldpage.PG_dirty
- sets newpage.PG_dirty
- uncharges oldpage from memcg
- charges newpage to memcg

Clearing oldpage.PG_dirty decrements the charged memcg's dirty page
count.

However, because newpage is not yet charged, setting newpage.PG_dirty
does not increment the memcg's dirty page count.  After migration
completes newpage.PG_dirty is eventually cleared, often in
account_page_cleaned().  At this time newpage is charged to a memcg so
the memcg's dirty page count is decremented which causes underflow
because the count was not previously incremented by migration.  This
underflow causes balance_dirty_pages() to see a very large unsigned
number of dirty memcg pages which leads to aggressive throttling of
buffered writes by processes in non root memcg.

This issue:
- can harm performance of non root memcg buffered writes.
- can report too small (even negative) values in
   memory.stat[(total_)dirty] counters of all memcg, including the root.

To avoid polluting migrate.c with #ifdef CONFIG_MEMCG checks, introduce
page_memcg() and set_page_memcg() helpers.

Test:
    0) setup and enter limited memcg
    mkdir /sys/fs/cgroup/test
    echo 1G > /sys/fs/cgroup/test/memory.limit_in_bytes
    echo $$ > /sys/fs/cgroup/test/cgroup.procs

    1) buffered writes baseline
    dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
    sync
    grep ^dirty /sys/fs/cgroup/test/memory.stat

    2) buffered writes with compaction antagonist to induce migration
    yes 1 > /proc/sys/vm/compact_memory &
    rm -rf /data/tmp/foo
    dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
    kill %
    sync
    grep ^dirty /sys/fs/cgroup/test/memory.stat

    3) buffered writes without antagonist, should match baseline
    rm -rf /data/tmp/foo
    dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k
    sync
    grep ^dirty /sys/fs/cgroup/test/memory.stat

                       (speed, dirty residue)
             unpatched                       patched
    1) 841 MB/s 0 dirty pages          886 MB/s 0 dirty pages
    2) 611 MB/s -33427456 dirty pages  793 MB/s 0 dirty pages
    3) 114 MB/s -33427456 dirty pages  891 MB/s 0 dirty pages

    Notice that unpatched baseline performance (1) fell after
    migration (3): 841 -> 114 MB/s.  In the patched kernel, post
    migration performance matches baseline.

Fixes: c4843a7593a9 ("memcg: add per cgroup dirty page accounting")
Signed-off-by: Greg Thelen <gthelen@google.com>
Reported-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org> [4.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dax: fix NULL pointer in __dax_pmd_fault()

Commit 46c043ede471 ("mm: take i_mmap_lock in unmap_mapping_range() for
DAX") moved some code in __dax_pmd_fault() that was responsible for
zeroing newly allocated PMD pages. The new location didn't properly set
up 'kaddr', so when run this code resulted in a NULL pointer BUG.

Fix this by getting the correct 'kaddr' via bdev_direct_access().

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@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>

mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault

SunDong reported the following on

  https://bugzilla.kernel.org/show_bug.cgi?id=103841

I think I find a linux bug, I have the test cases is constructed. I
can stable recurring problems in fedora22(4.0.4) kernel version,
arch for x86_64.  I construct transparent huge page, when the parent
and child process with MAP_SHARE, MAP_PRIVATE way to access the same
huge page area, it has the opportunity to lead to huge page copy on
write failure, and then it will munmap the child corresponding mmap
area, but then the child mmap area with VM_MAYSHARE attributes, child
process munmap this area can trigger VM_BUG_ON in set_vma_resv_flags
functions (vma - > vm_flags & VM_MAYSHARE).

There were a number of problems with the report (e.g.  it's hugetlbfs that
triggers this, not transparent huge pages) but it was fundamentally
correct in that a VM_BUG_ON in set_vma_resv_flags() can be triggered that
looks like this

vma ffff8804651fd0d0 start 00007fc474e00000 end 00007fc475e00000
next ffff8804651fd018 prev ffff8804651fd188 mm ffff88046b1b1800
prot 8000000000000027 anon_vma           (null) vm_ops ffffffff8182a7a0
pgoff 0 file ffff88106bdb9800 private_data           (null)
flags: 0x84400fb(read|write|shared|mayread|maywrite|mayexec|mayshare|dontexpand|hugetlb)
------------
kernel BUG at mm/hugetlb.c:462!
SMP
Modules linked in: xt_pkttype xt_LOG xt_limit [..]
CPU: 38 PID: 26839 Comm: map Not tainted 4.0.4-default #1
Hardware name: Dell Inc. PowerEdge R810/0TT6JF, BIOS 2.7.4 04/26/2012
set_vma_resv_flags+0x2d/0x30

The VM_BUG_ON is correct because private and shared mappings have
different reservation accounting but the warning clearly shows that the
VMA is shared.

When a private COW fails to allocate a new page then only the process
that created the VMA gets the page -- all the children unmap the page.
If the children access that data in the future then they get killed.

The problem is that the same file is mapped shared and private.  During
the COW, the allocation fails, the VMAs are traversed to unmap the other
private pages but a shared VMA is found and the bug is triggered.  This
patch identifies such VMAs and skips them.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: SunDong <sund_sky@126.com>
Reviewed-by: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Rientjes <rientjes@google.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)

Commit description is copied from the original post of this bug:

  http://comments.gmane.org/gmane.linux.kernel.mm/135349

Kernels after v3.9 use kmalloc_size(INDEX_NODE + 1) to get the next
larger cache size than the size index INDEX_NODE mapping.  In kernels
3.9 and earlier we used malloc_sizes[INDEX_L3 + 1].cs_size.

However, sometimes we can't get the right output we expected via
kmalloc_size(INDEX_NODE + 1), causing a BUG().

The mapping table in the latest kernel is like:
    index = {0,   1,  2 ,  3,  4,   5,   6,   n}
     size = {0,   96, 192, 8, 16,  32,  64,   2^n}
The mapping table before 3.10 is like this:
    index = {0 , 1 , 2,   3,  4 ,  5 ,  6,   n}
    size  = {32, 64, 96, 128, 192, 256, 512, 2^(n+3)}

The problem on my mips64 machine is as follows:

(1) When configured DEBUG_SLAB && DEBUG_PAGEALLOC && DEBUG_LOCK_ALLOC
    && DEBUG_SPINLOCK, the sizeof(struct kmem_cache_node) will be "150",
    and the macro INDEX_NODE turns out to be "2": #define INDEX_NODE
    kmalloc_index(sizeof(struct kmem_cache_node))

(2) Then the result of kmalloc_size(INDEX_NODE + 1) is 8.

(3) Then "if(size >= kmalloc_size(INDEX_NODE + 1)" will lead to "size
    = PAGE_SIZE".

(4) Then "if ((size >= (PAGE_SIZE >> 3))" test will be satisfied and
    "flags |= CFLGS_OFF_SLAB" will be covered.

(5) if (flags & CFLGS_OFF_SLAB)" test will be satisfied and will go to
    "cachep->slabp_cache = kmalloc_slab(slab_size, 0u)", and the result
    here may be NULL while kernel bootup.

(6) Finally,"BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));" causes the
    BUG info as the following shows (may be only mips64 has this problem):

This patch fixes the problem of kmalloc_size(INDEX_NODE + 1) and removes
the BUG by adding 'size >= 256' check to guarantee that all necessary
small sized slabs are initialized regardless sequence of slab size in
mapping table.

Fixes: e33660165c90 ("slab: Use common kmalloc_index/kmalloc_size...")
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reported-by: Liuhailong <liu.hailong6@zte.com.cn>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

userfaultfd: remove kernel header include from uapi header

As include/uapi/linux/userfaultfd.h is a user visible header file, it
should not include kernel-exclusive header files.

So trying to build the userfaultfd test program from the selftests
directory fails, since it contains a reference to linux/compiler.h. As
it turns out, that header is not really needed there, so we can simply
remove it to fix that issue.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/include/asm/efi.h: fix build failure

With KMEMCHECK=y, KASAN=n:

  arch/x86/platform/efi/efi.c:673:3: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
  arch/x86/platform/efi/efi_64.c:139:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]
  arch/x86/include/asm/desc.h:121:2: error: implicit declaration of function `memcpy' [-Werror=implicit-function-declaration]

Don't #undef memcpy if KASAN=n.

Fixes: 769a8089c1fd ("x86, efi, kasan: #undef memset/memcpy/memmove per arch")
Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Reported-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'drm-intel-fixes-2015-10-01' of git://anongit.freedesktop.org/drm-intel into drm-fixes

a few i915 fixes for v4.3.

* tag 'drm-intel-fixes-2015-10-01' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Call non-locking version of drm_kms_helper_poll_enable(), v2
  drm: Add a non-locking version of drm_kms_helper_poll_enable(), v2
  drm/i915: Consider HW CSB write pointer before resetting the sw read pointer
  drm/i915/skl: Don't call intel_prepare_ddi when encoder list isn't yet initialized.

Merge tag 'vmwgfx-fixes-4.3-151001' of git://people.freedesktop.org/~thomash/linux into drm-fixes

A single commit to fix a command submission hang regression.

Pull request of 2015-10-01

* tag 'vmwgfx-fixes-4.3-151001' of git://people.freedesktop.org/~thomash/linux:
drm/vmwgfx: Fix a command submission hang regression

Merge branch 'exynos-drm-fixes' of git://git./linux/kernel/git/daeinki/drm-exynos into drm-fixes

   This pull request includes regression fixups, build warnings, and
   trivial cleanups which mostly remove some codes not used anymore.

* 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
  drm/exynos: Staticize local function in exynos_drm_gem.c
  drm/exynos: fimd: actually disable dp clock
  drm/exynos: dp: remove suspend/resume functions
  drm/exynos: remove unused mode_fixup() code
  drm/exynos: remove decon_mode_fixup()
  drm/exynos: remove fimd_mode_fixup()
  drm/exynos: rotator: Clock control is unused if !PM
  drm/exynos: fimc: Clock control is unused if !PM
  drm/exynos: Suspend/resume is unused if !PM
  drm/exynos: create a fake mmap offset with gem creation
  drm/exynos: remove call to drm_gem_free_mmap_offset()
  drm/exynos: Remove useless EXPORT_SYMBOL_GPLs
  drm/exynos: cleanup line feed in exynos_drm_gem_get_ioctl
  drm/exynos: cleanup function calling written twice
  drm/exynos: staticize exynos_drm_gem_init()
  drm/exynos: remove unnecessary NULL assignment
  drm/exynos: fix missed calling of drm_prime_gem_destroy()
  drm/exynos: fix layering violation of address

Merge branch 'drm-fixes-4.3' of git://people.freedesktop.org/~agd5f/linux into drm-fixes

radeon and amdgpu fixes for 4.3.
- backlight s/r fixes
- typo fix from Dan
- vm debugging fix
- remove import_gpu_mem after discussion with Daniel

* 'drm-fixes-4.3' of git://people.freedesktop.org/~agd5f/linux:
  drm/amdgpu: only print meaningful VM faults
  drm/amdgpu/cgs: remove import_gpu_mem
  drm/amdgpu:  Restore LCD backlight level on resume
  drm/radeon: Restore LCD backlight level on resume (>= R5xx)
  drm/amdgpu: signedness bug in amdgpu_cs_parser_init()

Merge tag 'for-linus' of git://git./virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
"(Relatively) a lot of reverts, mostly.

  Bugs have trickled in for a new feature in 4.2 (MTRR support in
  guests) so I'm reverting it all; let's not make this -rc period busier
  for KVM than it's been so far.  This covers the four reverts from me.

  The fifth patch is being reverted because Radim found a bug in the
  implementation of stable scheduler clock, *but* also managed to
  implement the feature entirely without hypervisor support.  So instead
  of fixing the hypervisor side we can remove it completely; 4.4 will
  get the new implementation"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS
  Update KVM homepage Url
  Revert "KVM: SVM: use NPT page attributes"
  Revert "KVM: svm: handle KVM_X86_QUIRK_CD_NW_CLEARED in svm_get_mt_mask"
  Revert "KVM: SVM: Sync g_pat with guest-written PAT value"
  Revert "KVM: x86: apply guest MTRR virtualization on host reserved pages"
  Revert "KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR"

Merge tag 'for-linus' of git://git./linux/kernel/git/dledford/rdma

Pull rdma fixes from Doug Ledford:
- Fixes for mlx5 related issues
- Fixes for ipoib multicast handling

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  IB/ipoib: increase the max mcast backlog queue
  IB/ipoib: Make sendonly multicast joins create the mcast group
  IB/ipoib: Expire sendonly multicast joins
  IB/mlx5: Remove pa_lkey usages
  IB/mlx5: Remove support for IB_DEVICE_LOCAL_DMA_LKEY
  IB/iser: Add module parameter for always register memory
  xprtrdma: Replace global lkey with lkey local to PD

Merge branches 'pm-cpuidle', 'pm-opp' and 'pm-tools'

* pm-cpuidle:
  intel_idle: Skylake Client Support - updated

* pm-opp:
  PM / OPP: Fix typo modifcation -> modification
  PM / OPP: of_property_count_u32_elems() can return errors

* pm-tools:
  tools/power turbosat: update version number
  tools/power turbostat: SKL: Adjust for TSC difference from base frequency
  tools/power turbostat: KNL workaround for %Busy and Avg_MHz
  tools/power turbostat: IVB Xeon: fix --debug regression

Merge branch 'acpi-ec'

* acpi-ec:
ACPI / EC: Fix a memory leak issue in acpi_ec_query()

Merge branches 'pm-pci' and 'acpi-pci'

* pm-pci:
  PCI / PM: Update runtime PM documentation for PCI devices

* acpi-pci:
  ACPI / PCI: Remove duplicated penalty on SCI IRQ
  ACPI, PCI, irq: Do not share PCI IRQ with ISA IRQ

arm64: Fix THP protection change logic

6910fa1 ("arm64: enable PTE type bit in the mask for pte_modify") fixes
a problem whereby a large block of PROT_NONE mapped memory is
incorrectly mapped as block descriptors when mprotect is called.

Unfortunately, a subtle bug was introduced by this fix to the THP logic.

If one mmaps a large block of memory, then faults it such that it is
collapsed into THPs; resulting calls to mprotect on this area of memory
will lead to incorrect table descriptors being written instead of block
descriptors. This is because pmd_modify calls pte_modify which is now
allowed to modify the type of the page table entry.

This patch reverts commit 6910fa16dbe142f6a0fd0fd7c249f9883ff7fc8a, and
fixes the problem it was trying to address by adjusting PAGE_NONE to
represent a table entry. Thus no change in pte type is required when
moving from PROT_NONE to a different protection.

Fixes: 6910fa16dbe1 ("arm64: enable PTE type bit in the mask for pte_modify")
Cc: <stable@vger.kernel.org> # 4.0+
Cc: Feng Kan <fkan@apm.com>
Reported-by: Ganapatrao Kulkarni <Ganapatrao.Kulkarni@caviumnetworks.com>
Tested-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

MIPS: BPF: Do all exports of symbols with FEXPORT().

FEXPORT also marks the symbol as code using .type symbol, @function.
Without objdump -d will output only a hexdump for code following the
affected symbols.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS

The cpu feature flags are not ever going to change, so warning
everytime can cause a lot of kernel log spam
(in our case more than 10GB/hour).

The warning seems to only occur when nested virtualization is
enabled, so it's probably triggered by a KVM bug. This is a
sensible and safe change anyway, and the KVM bug fix might not
be suitable for stable releases anyway.

Cc: stable@vger.kernel.org
Signed-off-by: Dirk Mueller <dmueller@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Update KVM homepage Url

The old one appears to be a generic catch all page, which
is unhelpful.

Signed-off-by: Dirk Mueller <dmueller@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge tag 'upstream-4.3-rc4' of git://git.infradead.org/linux-ubifs

Pull UBI/UBIFS fixes from Richard Weinberger:
"This contains three bug fixes for both UBI and UBIFS"

* tag 'upstream-4.3-rc4' of git://git.infradead.org/linux-ubifs:
  UBI: return ENOSPC if no enough space available
  UBI: Validate data_size
  UBIFS: Kill unneeded locking in ubifs_init_security

Merge branch 'for-linus' of git://git./linux/kernel/git/jmorris/linux-security

Pull key signing fixes from James Morris:
"Keyrings and modsign fixes from David Howells"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  MODSIGN: Change from CMS to PKCS#7 signing if the openssl is too old
  X.509: Don't strip leading 00's from key ID when constructing key description
  KEYS: Remove unnecessary header #inclusions from extract-cert.c
  KEYS: Fix race between key destruction and finding a keyring by name

Revert "KVM: SVM: use NPT page attributes"

This reverts commit 3c2e7f7de3240216042b61073803b61b9b3cfb22.
Initializing the mapping from MTRR to PAT values was reported to
fail nondeterministically, and it also caused extremely slow boot
(due to caching getting disabled---bug 103321) with assigned devices.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Sebastian Schuette <dracon@ewetel.net>
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Revert "KVM: svm: handle KVM_X86_QUIRK_CD_NW_CLEARED in svm_get_mt_mask"

This reverts commit 5492830370171b6a4ede8a3bfba687a8d0f25fa5.
It builds on the commit that is being reverted next.

Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Revert "KVM: SVM: Sync g_pat with guest-written PAT value"

This reverts commit e098223b789b4a618dacd79e5e0dad4a9d5018d1,
which has a dependency on other commits being reverted.

Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Revert "KVM: x86: apply guest MTRR virtualization on host reserved pages"

This reverts commit fd717f11015f673487ffc826e59b2bad69d20fe5.
It was reported to cause Machine Check Exceptions (bug 104091).

Reported-by: harn-solo@gmx.de
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions

The new Properties Table feature introduced in UEFIv2.5 may
split memory regions that cover PE/COFF memory images into
separate code and data regions. Since these regions only differ
in the type (runtime code vs runtime data) and the permission
bits, but not in the memory type attributes (UC/WC/WT/WB), the
spec does not require them to be aligned to 64 KB.

Since the relative offset of PE/COFF .text and .data segments
cannot be changed on the fly, this means that we can no longer
pad out those regions to be mappable using 64 KB pages.
Unfortunately, there is no annotation in the UEFI memory map
that identifies data regions that were split off from a code
region, so we must apply this logic to all adjacent runtime
regions whose attributes only differ in the permission bits.

So instead of rounding each memory region to 64 KB alignment at
both ends, only round down regions that are not directly
preceded by another runtime region with the same type
attributes. Since the UEFI spec does not mandate that the memory
map be sorted, this means we also need to sort it first.

Note that this change will result in all EFI_MEMORY_RUNTIME
regions whose start addresses are not aligned to the OS page
size to be mapped with executable permissions (i.e., on kernels
compiled with 64 KB pages). However, since these mappings are
only active during the time that UEFI Runtime Services are being
invoked, the window for abuse is rather small.

Tested-by: Mark Salter <msalter@redhat.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [UEFI 2.4 only]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Reviewed-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org> # v4.0+
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443218539-7610-3-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down

Beginning with UEFI v2.5 EFI_PROPERTIES_TABLE was introduced
that signals that the firmware PE/COFF loader supports splitting
code and data sections of PE/COFF images into separate EFI
memory map entries. This allows the kernel to map those regions
with strict memory protections, e.g. EFI_MEMORY_RO for code,
EFI_MEMORY_XP for data, etc.

Unfortunately, an unwritten requirement of this new feature is
that the regions need to be mapped with the same offsets
relative to each other as observed in the EFI memory map. If
this is not done crashes like this may occur,

  BUG: unable to handle kernel paging request at fffffffefe6086dd
  IP: [<fffffffefe6086dd>] 0xfffffffefe6086dd
  Call Trace:
   [<ffffffff8104c90e>] efi_call+0x7e/0x100
   [<ffffffff81602091>] ? virt_efi_set_variable+0x61/0x90
   [<ffffffff8104c583>] efi_delete_dummy_variable+0x63/0x70
   [<ffffffff81f4e4aa>] efi_enter_virtual_mode+0x383/0x392
   [<ffffffff81f37e1b>] start_kernel+0x38a/0x417
   [<ffffffff81f37495>] x86_64_start_reservations+0x2a/0x2c
   [<ffffffff81f37582>] x86_64_start_kernel+0xeb/0xef

Here 0xfffffffefe6086dd refers to an address the firmware
expects to be mapped but which the OS never claimed was mapped.
The issue is that included in these regions are relative
addresses to other regions which were emitted by the firmware
toolchain before the "splitting" of sections occurred at
runtime.

Needless to say, we don't satisfy this unwritten requirement on
x86_64 and instead map the EFI memory map entries in reverse
order. The above crash is almost certainly triggerable with any
kernel newer than v3.13 because that's when we rewrote the EFI
runtime region mapping code, in commit d2f7cbe7b26a ("x86/efi:
Runtime services virtual mapping"). For kernel versions before
v3.13 things may work by pure luck depending on the
fragmentation of the kernel virtual address space at the time we
map the EFI regions.

Instead of mapping the EFI memory map entries in reverse order,
where entry N has a higher virtual address than entry N+1, map
them in the same order as they appear in the EFI memory map to
preserve this relative offset between regions.

This patch has been kept as small as possible with the intention
that it should be applied aggressively to stable and
distribution kernels. It is very much a bugfix rather than
support for a new feature, since when EFI_PROPERTIES_TABLE is
enabled we must map things as outlined above to even boot - we
have no way of asking the firmware not to split the code/data
regions.

In fact, this patch doesn't even make use of the more strict
memory protections available in UEFI v2.5. That will come later.

Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: <stable@vger.kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Chun-Yi <jlee@suse.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: James Bottomley <JBottomley@Odin.com>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1443218539-7610-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

genirq: Fix race in register_irq_proc()

Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created. In the case of
a shared IRQ, multiple tasks can race to create a directory. This
race condition seems to have been present forever, but is easier to
hit with async probing.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org

regulator: core: Handle probe deferral from DT when resolving supplies

When resolving regulator-regulator supplies we ignore probe deferral
returns from regulator_dev_lookup() (such as are generated for DT when
we can see a supply is registered) and just fall back to the dummy
regulator if there are full constraints (as is the case for DT). This
means that probe deferral is broken for DT systems, fix that by paying
attention to -EPROBE_DEFER return codes like we do -ENODEV.

A further patch will simplify this further, this is a minimal fix for
the specific issue.

Fixes: 9f7e25edb1575a6d2 (regulator: core: Handle full constraints systems when resolving supplies)
Reported-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonnie@kernel.org>
Cc: stable@vger.kernel.org

blk-mq: factor out a helper to iterate all tags for a request_queue

And replace the blk_mq_tag_busy_iter with it - the driver use has been
replaced with a new helper a while ago, and internal to the block we
only need the new version.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

blk-mq: fix racy updates of rq->errors

blk_mq_complete_request may be a no-op if the request has already
been completed by others means (e.g. a timeout or cancellation), but
currently drivers have to set rq->errors before calling
blk_mq_complete_request, which might leave us with the wrong error value.

Add an error parameter to blk_mq_complete_request so that we can
defer setting rq->errors until we known we won the race to complete the
request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

MIPS: Fix the build on jz4740 after removing the custom gpio.h

Somehow the wrong version of the patch to remove the use of custom
gpio.h on mips has been merged. This patch add the missing fixes for a
build error on jz4740 because linux/gpio.h doesn't provide any machine
specfics definitions anymore.

Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11089/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Merge remote-tracking branch 'tglx/x86/urgent' into x86/urgent

Pick up the WCHAN fixes from Thomas.

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

drm/exynos: Staticize local function in exynos_drm_gem.c

The exynos_drm_gem_mmap_buffer() is not used outside so make it static.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drm/exynos: fimd: actually disable dp clock

fimd_dp_clock_enable() was setting the always to enabled,
this patch fix this to actually use the value that is set to 'val'.

Reported-by: Emilio López <emilio.lopez@collabora.co.uk>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drm/exynos: dp: remove suspend/resume functions

This patch removes unnecessary pm suspend/resume functions.

All kms sub drivers will be controlled by top of Exynos drm driver
and connector dpms so these sub drivers shouldn't have their own
pm interfaces.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

drm/qxl: recreate the primary surface when the bo is not primary

When disabling/enabling a crtc the primary area must be updated
independently of which crtc has been disabled/enabled.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1264735

Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

dmaengine: pxa_dma: fix residue corner case

A very tiny temporal window exists in the residue calculation where :
- upon entering residue calculation, the transfer is ongoing
- when reading the current transfer pointer, it just changed to
   the "finisher/linker" descriptor

In this case, the residue returned is the whole transfer length instead
of 0. Fix it.

This appears almost in one extreme case, where the driver is used
by older clients which inquire for residue in interrupt context, such
as the smsc91x ethernet driver, in a tight loop :
  interrupt_handler()
    dmaengine_submit()
    do {
      dmaengine_tx_status()
    } while (residue > 0 || status != DMA_ERROR)

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: pxa_dma: fix the no-requestor case

A very small number of devices don't use the flow control offered by
requestor lines. In these specific cases, the pxa dma driver should be
aware of that and not try to use a requestor line.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: zxdma: Fix off-by-one for testing valid pchan request

The valid pchan range is 0 ~ d->dma_requests - 1.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: at_xdmac: clean used descriptor

When putting back a descriptor to the free descs list, some fields are
not set to 0, it can cause bugs if someone uses it without having this
in mind.
Descriptor are not put back one by one so it is easier to clean
descriptors when we request them.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: stable@vger.kernel.org #4.2
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

dmaengine: at_xdmac: change block increment addressing mode

The addressing mode we were using was not only incrementing the address at
each microblock, but also at each data boundary, which was severely slowing
the transfer, without any benefit since we were not using the data stride.

Switch to the micro block increment only in order to get back to an
acceptable performance level.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Fixes: 6007ccb57744 ("dmaengine: xdmac: Add interleaved transfer support")
Cc: stable@vger.kernel.org #4.2
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

x86/process: Unify 32bit and 64bit implementations of get_wchan()

The stack layout and the functionality is identical. Use the 64bit
version for all of x86.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Link: http://lkml.kernel.org/r/20150930083302.779694618@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

x86/process: Add proper bound checks in 64bit get_wchan()

Dmitry Vyukov reported the following using trinity and the memory
error detector AddressSanitizer
(https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel).

[ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on
address ffff88002e280000
[ 124.576801] ffff88002e280000 is located 131938492886538 bytes to
the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a)
[ 124.578633] Accessed by thread T10915:
[ 124.579295] inlined in describe_heap_address
./arch/x86/mm/asan/report.c:164
[ 124.579295] #0 ffffffff810dd277 in asan_report_error
./arch/x86/mm/asan/report.c:278
[ 124.580137] #1 ffffffff810dc6a0 in asan_check_region
./arch/x86/mm/asan/asan.c:37
[ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0
[ 124.581893] #3 ffffffff8107c093 in get_wchan
./arch/x86/kernel/process_64.c:444

The address checks in the 64bit implementation of get_wchan() are
wrong in several ways:

- The lower bound of the stack is not the start of the stack
   page. It's the start of the stack page plus sizeof (struct
   thread_info)

- The upper bound must be:

       top_of_stack - TOP_OF_KERNEL_STACK_PADDING - 2 * sizeof(unsigned long).

   The 2 * sizeof(unsigned long) is required because the stack pointer
   points at the frame pointer. The layout on the stack is: ... IP FP
   ... IP FP. So we need to make sure that both IP and FP are in the
   bounds.

Fix the bound checks and get rid of the mix of numeric constants, u64
and unsigned long. Making all unsigned long allows us to use the same
function for 32bit as well.

Use READ_ONCE() when accessing the stack. This does not prevent a
concurrent wakeup of the task and the stack changing, but at least it
avoids TOCTOU.

Also check task state at the end of the loop. Again that does not
prevent concurrent changes, but it avoids walking for nothing.

Add proper comments while at it.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Based-on-patch-from: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>