In the mipsr2_decoder() function, used to emulate pre-MIPSr6
instructions that were removed in MIPSr6, the init_fpu() function is
called if a removed pre-MIPSr6 floating point instruction is the first
floating point instruction used by the task. However, init_fpu()
performs varous actions that rely upon not being migrated. For example
in the most basic case it sets the coprocessor 0 Status.CU1 bit to
enable the FPU & then loads FP register context into the FPU registers.
If the task were to migrate during this time, it may end up attempting
to load FP register context on a different CPU where it hasn't set the
CU1 bit, leading to errors such as:

    do_cpu invoked from kernel context![#2]:
    CPU: 2 PID: 7338 Comm: fp-prctl Tainted: G      D         4.7.0-00424-g49b0c82 #2
    task: 838e4000 ti: 88d38000 task.ti: 88d38000
    $ 0   : 00000000 00000001 ffffffff 88d3fef8
    $ 4   : 838e4000 88d38004 00000000 00000001
    $ 8   : 3400fc01 801f8020 808e9100 24000000
    $12   : dbffffff 807b69d8 807b0000 00000000
    $16   : 00000000 80786150 00400fc4 809c0398
    $20   : 809c0338 0040273c 88d3ff28 808e9d30
    $24   : 808e9d30 00400fb4
    $28   : 88d38000 88d3fe88 00000000 8011a2ac
    Hi    : 0040273c
    Lo    : 88d3ff28
    epc   : 80114178 _restore_fp+0x10/0xa0
    ra    : 8011a2ac mipsr2_decoder+0xd5c/0x1660
    Status: 1400fc03	KERNEL EXL IE
    Cause : 1080002c (ExcCode 0b)
    PrId  : 0001a920 (MIPS I6400)
    Modules linked in:
    Process fp-prctl (pid: 7338, threadinfo=88d38000, task=838e4000, tls=766527d0)
    Stack : 00000000 00000000 00000000 88d3fe98 00000000 00000000 809c0398 809c0338
    	  808e9100 00000000 88d3ff28 00400fc4 00400fc4 0040273c 7fb69e18 004a0000
    	  004a0000 004a0000 7664add0 8010de18 00000000 00000000 88d3fef8 88d3ff28
    	  808e9100 00000000 766527d0 8010e534 000c0000 85755000 8181d580 00000000
    	  00000000 00000000 004a0000 00000000 766527d0 7fb69e18 004a0000 80105c20
    	  ...
    Call Trace:
    [<80114178>] _restore_fp+0x10/0xa0
    [<8011a2ac>] mipsr2_decoder+0xd5c/0x1660
    [<8010de18>] do_ri+0x90/0x6b8
    [<80105c20>] ret_from_exception+0x0/0x10

Fix this by disabling preemption around the call to init_fpu(), ensuring
that it starts & completes on one CPU.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: b0a668fb ("MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6")
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.0+
Patchwork: https://patchwork.linux-mips.org/patch/14305/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The page structures associated with the vDSO pages in the kernel image
are calculated using virt_to_page(), which uses __pa() under the hood to
find the pfn associated with the virtual address. The vDSO data pointers
however point to kernel symbols, so __pa_symbol() should really be used
instead.

Since there is no equivalent to virt_to_page() which uses __pa_symbol(),
fix init_vdso_image() to work directly with pfns, calculated with
__phys_to_pfn(__pa_symbol(...)).

This issue broke the Malta Enhanced Virtual Addressing (EVA)
configuration which has a non-default implementation of __pa_symbol().
This is because it uses a physical alias so that the kernel executes
from KSeg0 (VA 0x80000000 -> PA 0x00000000), while RAM is provided to
the kernel in the KUSeg range (VA 0x00000000 -> PA 0x80000000) which
uses the same underlying RAM.

Since there are no page structures associated with the low physical
address region, some arbitrary kernel memory would be interpreted as a
page structure for the vDSO pages and badness ensues.

Fixes: ebb5e78c ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/14229/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Add lost Kconfig symbol.  This should have been part of 40e084a5
('MIPS: Add uprobes support.').

Fixes: 40e084a5 ('MIPS: Add uprobes support.')
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Commit 44a7185c ("of/platform: Add common method to populate
default bus") added new arch_initcall of_platform_default_populate_init()
that will override device_initcall octeon_publish_devices(). This broke
many OCTEON boards as important devices are not getting probed anymore
(e.g. on EdgeRouter Lite the USB mass storage/rootfs is missing).

Fix by changing octeon_publish_devices() to arch_initcall.

Fixes: 44a7185c ("of/platform: Add common method to populate default bus")
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Rob Herring <robh@kernel.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14041/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Commit 1685ddbe ("MIPS: Octeon: Changes to support readq()/writeq()
usage.") added bitwise shift operations that assume that unsigned long
is always 64-bits. This broke the build of VDSO code, as it gets compiled
also in "faked" 32-bit mode. Althought the failing inline functions are
never executed in 32-bit mode, they still need to pass the compilation.
Fix by using 64-bit types explicitly.

The patch fixes the following build failure:

  CC      arch/mips/vdso/gettimeofday-o32.o
In file included from los/git/devel/linux/arch/mips/include/asm/io.h:32:0,
                 from los/git/devel/linux/arch/mips/include/asm/page.h:194,
                 from los/git/devel/linux/arch/mips/vdso/vdso.h:26,
                 from los/git/devel/linux/arch/mips/vdso/gettimeofday.c:11:
los/git/devel/linux/arch/mips/include/asm/mach-cavium-octeon/mangle-port.h: In function '__should_swizzle_bits':
los/git/devel/linux/arch/mips/include/asm/mach-cavium-octeon/mangle-port.h:19:40: error: right shift count >= width of type [-Werror=shift-count-overflow]
  unsigned long did = ((unsigned long)a >> 40) & 0xff;
                                        ^~

Fixes: 1685ddbe ("MIPS: Octeon: Changes to support readq()/writeq() usage.")
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: David Daney <ddaney@caviumnetworks.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Steven J. Hill <steven.hill@cavium.com>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14039/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

cpu_has_fpu macro uses smp_processor_id() and is currently executed
with preemption enabled, that triggers the warning at runtime.

It is assumed throughout the kernel that if any CPU has an FPU, then all
CPUs would have an FPU as well, so it is safe to perform the check with
preemption enabled - change the code to use raw_ variant of the check to
avoid the warning.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org  # 4.0+
Patchwork: https://patchwork.linux-mips.org/patch/14125/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Commit f70ddc07 ("MIPS: c-r4k: Avoid small flush_icache_range SMP
calls") adds checks to force use of hit-type cache ops for small icache
flushes where they are globalised & index-type cache ops aren't, in
order to avoid the overhead of IPIs in those cases. However it
calculated the size of the region being flushed incorrectly, subtracting
the end address from the start address rather than the reverse. This
would have led to an overflow with size wrapping round to some large
value, and likely to the special case for avoiding IPIs not actually
being hit.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Fixes: f70ddc07 ("MIPS: c-r4k: Avoid small flush_icache_range SMP calls")
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14211/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Commit 842dfc11 ("MIPS: Fix build with binutils 2.24.51+") missing
a ".set pop" in macro fpu_restore_16even, so add it.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Acked-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Steven J . Hill <Steven.Hill@caviumnetworks.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # 3.18+
Patchwork: https://patchwork.linux-mips.org/patch/14210/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

If the paravirt machine is compiles without CONFIG_SMP, the following
linker error occurs

arch/mips/kernel/head.o: In function `kernel_entry':
(.ref.text+0x10): undefined reference to `smp_bootstrap'

due to the kernel entry macro always including SMP startup code.
Wrap this code in CONFIG_SMP to fix the error.
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # 3.16+
Patchwork: https://patchwork.linux-mips.org/patch/14212/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Commit c1a0e9bc ("MIPS: Allow compact branch policy to be changed")
added Kconfig entries allowing for the compact branch policy used by the
compiler for MIPSr6 kernels to be specified. This can be useful for
debugging, particularly in systems where compact branches have recently
been introduced.

Unfortunately mainline gcc 5.x supports MIPSr6 but not the
-mcompact-branches compiler flag, leading to MIPSr6 kernels failing to
build with gcc 5.x with errors such as:

  mipsel-linux-gnu-gcc: error: unrecognized command line option '-mcompact-branches=optimal'
  make[2]: *** [kernel/bounds.s] Error 1

Fixing this by hiding the Kconfig entry behind another seems to be more
hassle than it's worth, as MIPSr6 & compact branches have been around
for a while now and if policy does need to be set for debug it can be
done easily enough with KCFLAGS. Therefore remove the compact branch
policy Kconfig entries & their handling in the Makefile.

This reverts commit c1a0e9bc ("MIPS: Allow compact branch policy to
be changed").
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: c1a0e9bc ("MIPS: Allow compact branch policy to be changed")
Cc: stable <stable@vger.kernel.org> # v4.4+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14241/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

The alignment of MIPS MAAR region addresses isn't quite right.

- It rounds an already 64 KiB aligned start address up to the next
  64 KiB boundary, e.g. 0x80000000 is rounded up to 0x80010000.

- It assumes the end address is already on a 64 KiB boundary and doesn't
  round it down. Should that not be the case it will hit the second
  BUG_ON() in write_maar_pair().

Both cases are addressed by rounding up and down to 64 KiB boundaries in
the more traditional way of adding 0xffff (for rounding up) and masking
off the low 16 bits.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13858/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Memory regions added with add_memory_region() at the top of the physical
address space will have their end address overflow to 0. This causes
them to be rejected as invalid, and would cause various other issues
later on.

This causes issues on Malta and Boston platforms when wanting to use all
2GB of RAM on a 32-bit kernel, either via highmem (using physical
addresses 0x90000000..0xFFFFFFFF), or with the Malta Enhanced Virtual
Addressing (EVA) layout which exposes the whole 0x80000000..0xFFFFFFFF
physical address range to kernel mode at 0x00000000..0x7FFFFFFF.

Due to the abundance of these non-overflow assumptions and the fact that
memblock already avoids the arithmetic overflow by limiting the size of
new memory regions without the arch code knowing it (in particular
mem_init_free_highmem() will trigger a page dump due to nonzero mapcount
on the last page), it is simpler and safer to just limit the size of the
region in a similar way to memblock but at the arch level to allow most
of the RAM to be used without arithmetic overflows.

Therefore we detect this case specifically and reduce the size of the
region slightly to avoid the arithmetic overflows and cause the last
page to be ignored.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13857/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

When a uprobe-replacement breakpoint instruction is handled, a notifier
is called with DIE_UPROBE argument, but a corresponding exception notify
handler for MIPS attempts to handle DIE_BREAK instead. As a result
the breakpoint instruction isn't handled by the uprobe code and the probed
application terminates with SIGTRAP.
Fix this by changing arch_uprobe_exception_notify code to handle
DIE_UPROBE as a pre-singlestep condition instead of DIE_BREAK.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13884/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

clk_register_fixed_factor returns an ERR_PTR in case of an error and
should have an IS_ERR check instead of a null check.

The Coccinelle semantic patch used to find this issue is as follows:
@@
expression e;
statement S;
@@

*e = clk_register_fixed_factor(...);
if (!e) S
Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Cc: julia.lawall@lip6.fr
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13894/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Commit aa719874 ("nvme: fabrics drivers don't need the nvme-pci
driver") removed the dependency on BLK_DEV_NVME, but the cdoe does
depend on the block layer (which used to be an implicit dependency
through BLK_DEV_NVME).

Otherwise you get various errors from the kbuild test robot random
config testing when that happens to hit a configuration with BLOCK
device support disabled.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jay Freyensee <james_p_freyensee@linux.intel.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull IIO fixes from Greg KH:
 "Here are a few small IIO fixes for 4.8-rc6.

  Nothing major, full details are in the shortlog, all of these have
  been in linux-next with no reported issues"

* tag 'staging-4.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio:core: fix IIO_VAL_FRACTIONAL sign handling
  iio: ensure ret is initialized to zero before entering do loop
  iio: accel: kxsd9: Fix scaling bug
  iio: accel: bmc150: reset chip at init time
  iio: fix pressure data output unit in hid-sensor-attributes
  tools:iio:iio_generic_buffer: fix trigger-less mode

Pull USB fixes from Greg KH:
 "Here are some small USB gadget, phy, and xhci fixes for 4.8-rc6.

  All of these resolve minor issues that have been reported, and all
  have been in linux-next with no reported issues"

* tag 'usb-4.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: chipidea: udc: fix NULL ptr dereference in isr_setup_status_phase
  xhci: fix null pointer dereference in stop command timeout function
  usb: dwc3: pci: fix build warning on !PM_SLEEP
  usb: gadget: prevent potenial null pointer dereference on skb->len
  usb: renesas_usbhs: fix clearing the {BRDY,BEMP}STS condition
  usb: phy: phy-generic: Check clk_prepare_enable() error
  usb: gadget: udc: renesas-usb3: clear VBOUT bit in DRD_CON
  Revert "usb: dwc3: gadget: always decrement by 1"

Pull libnvdimm fixes from Dan Williams:
 "nvdimm fixes for v4.8, two of them are tagged for -stable:

   - Fix devm_memremap_pages() to use track_pfn_insert().  Otherwise,
     DAX pmd mappings end up with an uncached pgprot, and unusable
     performance for the device-dax interface.  The device-dax interface
     appeared in 4.7 so this is tagged for -stable.

   - Fix a couple VM_BUG_ON() checks in the show_smaps() path to
     understand DAX pmd entries.  This fix is tagged for -stable.

   - Fix a mis-merge of the nfit machine-check handler to flip the
     polarity of an if() to match the final version of the patch that
     Vishal sent for 4.8-rc1.  Without this the nfit machine check
     handler never detects / inserts new 'badblocks' entries which
     applications use to identify lost portions of files.

   - For test purposes, fix the nvdimm_clear_poison() path to operate on
     legacy / simulated nvdimm memory ranges.  Without this fix a test
     can set badblocks, but never clear them on these ranges.

   - Fix the range checking done by dax_dev_pmd_fault().  This is not
     tagged for -stable since this problem is mitigated by specifying
     aligned resources at device-dax setup time.

  These patches have appeared in a next release over the past week.  The
  recent rebase you can see in the timestamps was to drop an invalid fix
  as identified by the updated device-dax unit tests [1].  The -mm
  touches have an ack from Andrew"

[1]: "[ndctl PATCH 0/3] device-dax test for recent kernel bugs"
   https://lists.01.org/pipermail/linux-nvdimm/2016-September/006855.html

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm: allow legacy (e820) pmem region to clear bad blocks
  nfit, mce: Fix SPA matching logic in MCE handler
  mm: fix cache mode of dax pmd mappings
  mm: fix show_smap() for zone_device-pmd ranges
  dax: fix mapping size check

Pull i2c fixes from Wolfram Sang:
 "Mostly driver bugfixes, but also a few cleanups which are nice to have
  out of the way"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: rk3x: Restore clock settings at resume time
  i2c: Spelling s/acknowedge/acknowledge/
  i2c: designware: save the preset value of DW_IC_SDA_HOLD
  Documentation: i2c: slave-interface: add note for driver development
  i2c: mux: demux-pinctrl: run properly with multiple instances
  i2c: bcm-kona: fix inconsistent indenting
  i2c: rcar: use proper device with dma_mapping_error
  i2c: sh_mobile: use proper device with dma_mapping_error
  i2c: mux: demux-pinctrl: invalidate properly when switching fails

Pull fscrypto fixes fromTed Ts'o:
 "Fix some brown-paper-bag bugs for fscrypto, including one one which
  allows a malicious user to set an encryption policy on an empty
  directory which they do not own"

* tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  fscrypto: require write access to mount to set encryption policy
  fscrypto: only allow setting encryption policy on directories
  fscrypto: add authorization check for setting encryption policy

Since setting an encryption policy requires writing metadata to the
filesystem, it should be guarded by mnt_want_write/mnt_drop_write.
Otherwise, a user could cause a write to a frozen or readonly
filesystem.  This was handled correctly by f2fs but not by ext4.  Make
fscrypt_process_policy() handle it rather than relying on the filesystem
to get it right.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@vger.kernel.org # 4.1+; check fs/{ext4,f2fs}
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>

The FS_IOC_SET_ENCRYPTION_POLICY ioctl allowed setting an encryption
policy on nondirectory files.  This was unintentional, and in the case
of nonempty regular files did not behave as expected because existing
data was not actually encrypted by the ioctl.

In the case of ext4, the user could also trigger filesystem errors in
->empty_dir(), e.g. due to mismatched "directory" checksums when the
kernel incorrectly tried to interpret a regular file as a directory.

This bug affected ext4 with kernels v4.8-rc1 or later and f2fs with
kernels v4.6 and later.  It appears that older kernels only permitted
directories and that the check was accidentally lost during the
refactoring to share the file encryption code between ext4 and f2fs.

This patch restores the !S_ISDIR() check that was present in older
kernels.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

On an ext4 or f2fs filesystem with file encryption supported, a user
could set an encryption policy on any empty directory(*) to which they
had readonly access.  This is obviously problematic, since such a
directory might be owned by another user and the new encryption policy
would prevent that other user from creating files in their own directory
(for example).

Fix this by requiring inode_owner_or_capable() permission to set an
encryption policy.  This means that either the caller must own the file,
or the caller must have the capability CAP_FOWNER.

(*) Or also on any regular file, for f2fs v4.6 and later and ext4
    v4.8-rc1 and later; a separate bug fix is coming for that.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@vger.kernel.org # 4.1+; check fs/{ext4,f2fs}
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Bad blocks can be injected via /sys/block/pmemN/badblocks. In a situation
where legacy pmem is being used or a pmem region created by using memmap
kernel parameter, the injected bad blocks are not cleared due to
nvdimm_clear_poison() failing from lack of ndctl function pointer. In
this case we need to just return as handled and allow the bad blocks to
be cleared rather than fail.
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

The check for a 'pmem' type SPA in the MCE handler was inverted due to a
merge/rebase error.

Fixes: 6839a6d9 nfit: do an ARS scrub on hitting a latent media error
Cc: linux-acpi@vger.kernel.org
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

track_pfn_insert() in vmf_insert_pfn_pmd() is marking dax mappings as
uncacheable rendering them impractical for application usage.  DAX-pte
mappings are cached and the goal of establishing DAX-pmd mappings is to
attain more performance, not dramatically less (3 orders of magnitude).

track_pfn_insert() relies on a previous call to reserve_memtype() to
establish the expected page_cache_mode for the range.  While memremap()
arranges for reserve_memtype() to be called, devm_memremap_pages() does
not.  So, teach track_pfn_insert() and untrack_pfn() how to handle
tracking without a vma, and arrange for devm_memremap_pages() to
establish the write-back-cache reservation in the memtype tree.

Cc: <stable@vger.kernel.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Toshi Kani <toshi.kani@hpe.com>
Reported-by: Kai Zhang <kai.ka.zhang@oracle.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Attempting to dump /proc/<pid>/smaps for a process with pmd dax mappings
currently results in the following VM_BUG_ONs:

 kernel BUG at mm/huge_memory.c:1105!
 task: ffff88045f16b140 task.stack: ffff88045be14000
 RIP: 0010:[<ffffffff81268f9b>]  [<ffffffff81268f9b>] follow_trans_huge_pmd+0x2cb/0x340
 [..]
 Call Trace:
  [<ffffffff81306030>] smaps_pte_range+0xa0/0x4b0
  [<ffffffff814c2755>] ? vsnprintf+0x255/0x4c0
  [<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0
  [<ffffffff8123c8a2>] walk_page_vma+0x62/0x80
  [<ffffffff81307656>] show_smap+0xa6/0x2b0

 kernel BUG at fs/proc/task_mmu.c:585!
 RIP: 0010:[<ffffffff81306469>]  [<ffffffff81306469>] smaps_pte_range+0x499/0x4b0
 Call Trace:
  [<ffffffff814c2795>] ? vsnprintf+0x255/0x4c0
  [<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0
  [<ffffffff8123c8a2>] walk_page_vma+0x62/0x80
  [<ffffffff81307696>] show_smap+0xa6/0x2b0

These locations are sanity checking page flags that must be set for an
anonymous transparent huge page, but are not set for the zone_device
pages associated with dax mappings.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Pull virtio fixes from Michael Tsirkin:
 "This includes a couple of bugfixs for virtio.

  The virtio console patch is actually also in x86/tip targeting 4.9
  because it helps vmap stacks, but it also fixes IOMMU_PLATFORM which
  was added in 4.8, and it seems important not to ship that in a broken
  configuration"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_console: Stop doing DMA on the stack
  virtio: mark vring_dma_dev() static

Pull power management fixes from Rafael Wysocki:
 "This includes a PM QoS framework fix from Tejun to prevent interrupts
  from being enabled unexpectedly during early boot and a cpufreq
  documentation fix.

  Specifics:

   - If the PM QoS framework invokes cancel_delayed_work_sync() during
     early boot, it will enable interrupts which is not expected at that
     point, so prevent it from happening (Tejun Heo)

   - Fix cpufreq statistic documentation to follow a recent change in
     behavior that forgot to update it as appropriate (Jean Delvare)"

* tag 'pm-4.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq-stats: Minor documentation fix
  PM / QoS: avoid calling cancel_delayed_work_sync() during early boot

* pm-core-fixes:
  PM / QoS: avoid calling cancel_delayed_work_sync() during early boot

* pm-cpufreq-fixes:
  cpufreq-stats: Minor documentation fix

Pull GPIO fixes from Linus Walleij:
 "Some GPIO fixes that have been boiling the last two weeks or so.
  Nothing special, I'm trying to sort out some Kconfig business and
  Russell needs a fix in for -his SA1100 rework.

  Summary:

   - Revert a pointless attempt to add an include to solve the UM allyes
     compilation problem.

   - Make the mcp23s08 depend on OF_GPIO as it uses it and doesn't
     compile properly without it.

   - Fix a probing problem for ucb1x00"

* tag 'gpio-v4.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: sa1100: fix irq probing for ucb1x00
  gpio: mcp23s08: make driver depend on OF_GPIO
  Revert "gpio: include <linux/io-mapping.h> in gpiolib-of"

Pull fuse fix from Miklos Szeredi:
 "This fixes a deadlock when fuse, direct I/O and loop device are
  combined"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: direct-io: don't dirty ITER_BVEC pages

Pull overlayfs fix from Miklos Szeredi:
 "This fixes a regression caused by the last pull request"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix workdir creation

Pull btrfs fixes from Chris Mason:
 "I'm not proud of how long it took me to track down that one liner in
  btrfs_sync_log(), but the good news is the patches I was trying to
  blame for these problems were actually fine (sorry Filipe)"

* 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: introduce tickets_id to determine whether asynchronous metadata reclaim work makes progress
  btrfs: remove root_log_ctx from ctx list before btrfs_sync_log returns
  btrfs: do not decrease bytes_may_use when replaying extents

Pull sound fixes from Takashi Iwai:
 "We've got quite a few fixes at this time, and all are stable patches.

  syzkaller strikes back again (episode 19 or so), and we had to plug
  some holes in ALSA core part (mostly timer).

  In addition, a couple of FireWire audio fixes for the invalid copy
  user calls in locks, and a few quirks for HD-audio and USB-audio as
  usual are included"

* tag 'sound-4.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: rawmidi: Fix possible deadlock with virmidi registration
  ALSA: timer: Fix zero-division by continue of uninitialized instance
  ALSA: timer: fix NULL pointer dereference in read()/ioctl() race
  ALSA: fireworks: accessing to user space outside spinlock
  ALSA: firewire-tascam: accessing to user space outside spinlock
  ALSA: hda - Enable subwoofer on Dell Inspiron 7559
  ALSA: hda - Add headset mic quirk for Dell Inspiron 5468
  ALSA: usb-audio: Add sample rate inquiry quirk for B850V3 CP2114
  ALSA: timer: fix NULL pointer dereference on memory allocation failure
  ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE

virtio_console uses a small DMA buffer for control requests.  Move
that buffer into heap memory.

Doing virtio DMA on the stack is normally okay on non-DMA-API virtio
systems (which is currently most of them), but it breaks completely
if the stack is virtually mapped.

Tested by typing both directions using picocom aimed at /dev/hvc0.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>

We get 1 warning when building kernel with W=1:
drivers/virtio/virtio_ring.c:170:16: warning: no previous prototype for 'vring_dma_dev' [-Wmissing-prototypes]

In fact, this function is only used in the file in which it is
declared and don't need a declaration, but can be made static.
so this patch marks this function with 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Pull arm64 fixes from Catalin Marinas:

 - smp_mb__before_spinlock() changed to smp_mb() on arm64 since the
   generic definition to smp_wmb() is not sufficient

 - avoid a recursive loop with the graph tracer by using using
   preempt_(enable|disable)_notrace in _percpu_(read|write)

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: use preempt_disable_notrace in _percpu_read/write
  arm64: spinlocks: implement smp_mb__before_spinlock() as smp_mb()

Pull powerpc fixes from Michael Ellerman:
 "Fixes marked for stable:
   - Don't alias user region to other regions below PAGE_OFFSET from
     Paul Mackerras
   - Fix again csum_partial_copy_generic() on 32-bit from Christophe
     Leroy
   - Fix corrupted PE allocation bitmap on releasing PE from Gavin Shan

  Fixes for code merged this cycle:
   - Fix crash on releasing compound PE from Gavin Shan
   - Fix processor numbers in OPAL ICP from Benjamin Herrenschmidt
   - Fix little endian build with CONFIG_KEXEC=n from Thiago Jung
     Bauermann"

* tag 'powerpc-4.8-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Don't alias user region to other regions below PAGE_OFFSET
  powerpc/32: Fix again csum_partial_copy_generic()
  powerpc/powernv: Fix corrupted PE allocation bitmap on releasing PE
  powerpc/powernv: Fix crash on releasing compound PE
  powerpc/xics/opal: Fix processor numbers in OPAL ICP
  powerpc/pseries: Fix little endian build with CONFIG_KEXEC=n