When we deactivate the AFU directed mode we free the scheduled process
area, but did not clear the register in the hardware that has a pointer
to it.

This should be fine since we will have already cleared out every context
and we won't do anything that would cause the hardware to access it
until after we have allocated a new one, but just to be safe this patch
clears out the register when we free the page.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Upon inspection of the implementation specific registers, it was
discovered that the high bit of the implementation specific RXCTL
register was enabled, which enables the DEADB00F debug feature.

The debug feature causes MMIO reads to a disabled AFU to respond with
0xDEADB00F instead of all Fs. In general this should not be visible as
the kernel will only allow MMIO access to enabled AFUs, but there may be
some circumstances where an AFU may become disabled while it is use.
One such case would be an AFU designed to only be used in the dedicated
process mode and to disable itself after it has completed it's work
(however even in that case the effects of this debug flag would be
limited as the userspace application must have completed any required
MMIO accesses before the AFU disables itself with or without the flag).

This patch removes the debug flag and replaces the magic value
programmed into this register with a preprocessor define so it is
clearer what the rest of this initialisation does.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

If a context is being detached and we get a translation fault for it
there is little point getting it's mm and handling the fault, so just
respond with an address error and return earlier.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In this particular error path we have already allocated the AFU
interrupts, but have not yet set the status to STARTED. The detach
context code will only attempt to release the interrupts if the context
is in state STARTED, so in this case the interrupts would remain
allocated.

This patch releases the AFU interrupts immediately if the attach call
fails to prevent them leaking.
Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

In case of error, the function ioremap() returns NULL
not ERR_PTR(). The IS_ERR() test in the return value
check should be replaced with NULL test.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

isxdigit() macro definition is the same.

isalnum() from linux/ctype.h will accept additional latin non-ASCII
characters. This is harmless since this macro is used in scanhex() which
parses user input.

isspace() from linux/ctype.h will accept vertical tab and form feed but
not NULL. The use of this macro is modified to accept NULL as
well. Additional characters are harmless since this macro is also only
used in scanhex().
Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Moving config DTL up so it is below config PPC_SPLPAR means that
menuconfig will show config DTL nicely indented right below config
PPC_SPLPAR when PPC_SPLPAR is enabled.

To contrast that, right now if I enable PPC_SPLPAR in menuconfig, all I
can immediately tell is that "something showed up further down the list
where I wasn't looking", and I end up having to toggle the option a few
times to figure out what showed up, or look at the KConfig to find out
that config DTL depends on config PPC_SPLPAR.
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Pull KVM fixes from Paolo Bonzini:
 "The important fixes are for two bugs introduced by the merge window.

  On top of this, add a couple of WARN_ONs and stop spamming dmesg on
  pretty much every boot of a virtual machine"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: warn on more invariant breakage
  kvm: fix sorting of memslots with base_gfn == 0
  kvm: x86: drop severity of "generation wraparound" message
  kvm: x86: vmx: reorder some msr writing

Pull vfs fix from Al Viro:
 "An embarrassing bug in lustre patches from this cycle ;-/"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [regression] braino in "lustre: use is_root_inode()"

Modifying a non-existent slot is not allowed.  Also check that the
first loop doesn't move a deleted slot beyond the used part of
the mslots array.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Before commit 0e60b079 (kvm: change memslot sorting rule from size
to GFN, 2014-12-01), the memslots' sorting key was npages, meaning
that a valid memslot couldn't have its sorting key equal to zero.
On the other hand, a valid memslot can have base_gfn == 0, and invalid
memslots are identified by base_gfn == npages == 0.

Because of this, commit 0e60b079 broke the invariant that invalid
memslots are at the end of the mslots array.  When a memslot with
base_gfn == 0 was created, any invalid memslot before it were left
in place.

This can be fixed by changing the insertion to use a ">=" comparison
instead of "<=", but some care is needed to avoid breaking the case
of deleting a memslot; see the comment in update_memslots.

Thanks to Tiejun Chen for posting an initial patch for this bug.
Reported-by: Jamie Heilman <jamie@audible.transient.net>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Tested-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull sound fixes from Takashi Iwai:
 "Just a couple of fixes for the new Intel Skylake HD-audio support"

* tag 'sound-3.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda_intel: apply the Seperate stream_tag for Skylake
  ALSA: hda_controller: Separate stream_tag for input and output streams.

Since most virtual machines raise this message once, it is a bit annoying.
Make it KERN_DEBUG severity.

Cc: stable@vger.kernel.org
Fixes: 7a2e8aafSigned-off-by: Paolo Bonzini <pbonzini@redhat.com>

The commit 34a1cd60, "x86: vmx: move some vmx setting from
vmx_init() to hardware_setup()", tried to refactor some codes
specific to vmx hardware setting into hardware_setup(), but some
msr writing should depend on our previous setting condition like
enable_apicv, enable_ept and so on.
Reported-by: Jamie Heilman <jamie@audible.transient.net>
Tested-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

In one of the places (ll_md_blocking_ast()) we had open-coded
!is_root_inode(inode) and replaced it with is_root_inode(inode).
See the last chunk of f76c23:
-                   inode != inode->i_sb->s_root->d_inode)
+                   is_root_inode(inode))
should've been
+                   !is_root_inode(inode))
obviously...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull parisc build fix from Helge Deller:
 "This unbreaks the kernel compilation on parisc with gcc-4.9"

* 'parisc-3.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: fix out-of-register compiler error in ldcw inline assembler function

The __ldcw macro has a problem when its argument needs to be reloaded from
memory. The output memory operand and the input register operand both need to
be reloaded using a register in class R1_REGS when generating 64-bit code.
This fails because there's only a single register in the class. Instead, use a
memory clobber. This also makes the __ldcw macro a compiler memory barrier.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org>        [3.13+]
Signed-off-by: Helge Deller <deller@gmx.de>

The total stream number of Skylake's input and output stream
exceeds 15, which will cause some streams do not work because
of the overflow on SDxCTL.STRM field if using the legacy
stream tag allocation method.

This patch uses the new stream tag allocation method by add
the flag AZX_DCAPS_SEPARATE_STREAM_TAG for Skylake platform.
Signed-off-by: Libin Yang <libin.yang@intel.com>
Reviewed-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Implemented separate stream_tag assignment for input and output streams.
According to hda specification stream tag must be unique throughout the
input streams group, however an output stream might use a stream tag
which is already in use by an input stream. This change is necessary
to support HW which provides a total of more than 15 stream DMA engines
which with legacy implementation causes an overflow on SDxCTL.STRM
field (and the whole SDxCTL register) and as a result usage of
Reserved value 0 in the SDxCTL.STRM field which confuses HDA controller.
Signed-off-by: Rafal Redzimski <rafal.f.redzimski@intel.com>
Signed-off-by: Jayachandran B <jayachandran.b@intel.com>
Signed-off-by: Libin Yang <libin.yang@intel.com>
Reviewed-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Pull drm fixes from Dave Airlie:
 "Xmas fixes pull:

  core:
      one atomic fix, revert the WARN_ON dumb buffers patch.

  agp:
      fixup Dave J.

  nouveau:
      fix 3.18 regression for old userspace

  tegra fixes:
      vblank and iommu fixes

  amdkfd:
      fix bugs shown by testing with userspace, init apertures once

  msm:
      hdmi fixes and cleanup

  i915:
      misc fixes

  There is also a link ordering fix that I've asked to be cc'ed to you,
  putting iommu before gpu, it fixes an issue with amdkfd when things
  are all in the kernel, but I didn't like sending it via my tree
  without discussion.

  I'll probably be a bit on/off for a few weeks with pulls now, due to
  holidays and LCA, so don't be surprised if stuff gets a bit backed up,
  and things end up a bit large due to lag"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (28 commits)
  Revert "drm/gem: Warn on illegal use of the dumb buffer interface v2"
  agp: Fix up email address & attributions in AGP MODULE_AUTHOR tags
  nouveau: bring back legacy mmap handler
  drm/msm/hdmi: rework HDMI IRQ handler
  drm/msm/hdmi: enable regulators before clocks to avoid warnings
  drm/msm/mdp5: update irqs on crtc<->encoder link change
  drm/msm: block incoming update on pending updates
  drm/atomic: fix potential null ptr on plane enable
  drm/msm: Deletion of unnecessary checks before the function call "release_firmware"
  drm/msm: Deletion of unnecessary checks before two function calls
  drm/tegra: dc: Select root window for event dispatch
  drm/tegra: gem: Use the proper size for GEM objects
  drm/tegra: gem: Flush buffer objects upon allocation
  drm/tegra: dc: Fix a potential race on page-flip completion
  drm/tegra: dc: Consistently use the same pipe
  drm/irq: Add drm_crtc_vblank_count()
  drm/irq: Add drm_crtc_handle_vblank()
  drm/irq: Add drm_crtc_send_vblank_event()
  drm/i915: Disable PSMI sleep messages on all rings around context switches
  drm/i915: Force the CS stall for invalidate flushes
  ...

Pull ipmi driver bugfixes from Corey Minyard:
 "Fix two bugs:

  One that lockdep turned up, I didn't go far enough with cleanup of
  attributes for IPMI.  This has been there a long time; my previous fix
  of this didn't fix all the attributes.

  One fix for some arches that need an explicit linux/ctype.h for
  isspace()"

* tag 'for-linus-2' of git://git.code.sf.net/p/openipmi/linux-ipmi:
  ipmi: Fix compile issue with isspace()
  ipmi: Finish cleanup of BMC attributes

This reverts commit 355a7018.

This had some bad side effects under normal operation, and should
have been dropped earlier.
Signed-off-by: Dave Airlie <airlied@redhat.com>

- Display MEC fw version in topology. Without this, the HSA userspace
  stack is broken.

- Init apertures information only once per process

* tag 'amdkfd-fixes-2014-12-23' of git://people.freedesktop.org/~gabbayo/linux:
  amdkfd: init aperture once per process
  amdkfd: Display MEC fw version in topology node
  drm/radeon: Add implementation of get_fw_version
  drm/amd: Add get_fw_version to kfd-->kgd interface

Pull audit fixes from Paul Moore:
 "Four patches to fix various problems with the audit subsystem, all are
  fairly small and straightforward.

  One patch fixes a problem where we weren't using the correct gfp
  allocation flags (GFP_KERNEL regardless of context, oops), one patch
  fixes a problem with old userspace tools (this was broken for a
  while), one patch fixes a problem where we weren't recording pathnames
  correctly, and one fixes a problem with PID based filters.

  In general I don't think there is anything controversial with this
  patchset, and it fixes some rather unfortunate bugs; the allocation
  flag one can be particularly scary looking for users"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: restore AUDIT_LOGINUID unset ABI
  audit: correctly record file names with different path name types
  audit: use supplied gfp_mask from audit_buffer in kauditd_send_multicast_skb
  audit: don't attempt to lookup PIDs when changing PID filtering audit rules

A regression was caused by commit 780a7654:
	 audit: Make testing for a valid loginuid explicit.
(which in turn attempted to fix a regression caused by e1760bd5)

When audit_krule_to_data() fills in the rules to get a listing, there was a
missing clause to convert back from AUDIT_LOGINUID_SET to AUDIT_LOGINUID.

This broke userspace by not returning the same information that was sent and
expected.

The rule:
	auditctl -a exit,never -F auid=-1
gives:
	auditctl -l
		LIST_RULES: exit,never f24=0 syscall=all
when it should give:
		LIST_RULES: exit,never auid=-1 (0xffffffff) syscall=all

Tag it so that it is reported the same way it was set.  Create a new
private flags audit_krule field (pflags) to store it that won't interact with
the public one from the API.

Cc: stable@vger.kernel.org # v3.10-rc1+
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

Pull arm64 fixes from Catalin Marinas:
 - __cpu_suspend mm switching fix after warm boot
 - arch_setup_dma_ops implementation
 - pgd_page compilation error fix
 - defconfig updates

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mm: Add pgd_page to support RCU fast_gup
  arm64: defconfig: defconfig update for 3.19
  arm64: kernel: fix __cpu_suspend mm switch on warm-boot
  arm64: Replace set_arch_dma_coherent_ops with arch_setup_dma_ops

This patch adds pgd_page definition in order to keep supporting
HAVE_GENERIC_RCU_GUP configuration. In addition, it changes pud_page
expression to align with pmd_page for readability.

An introduction of pgd_page resolves the following build breakage
under 4KB + 4Level memory management combo.

mm/gup.c: In function 'gup_huge_pgd':
mm/gup.c:889:2: error: implicit declaration of function 'pgd_page' [-Werror=implicit-function-declaration]
  head = pgd_page(orig);
  ^
mm/gup.c:889:7: warning: assignment makes pointer from integer without a cast
  head = pgd_page(orig);

Cc: Will Deacon <will.deacon@arm.com>
Cc: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
[catalin.marinas@arm.com: remove duplicate pmd_page definition]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The usual defconfig tweaks, this time:

  - FHANDLE and AUTOFS4_FS to keep systemd happy
  - PID_NS, QUOTA and KEYS to keep LTP happy
  - Disable DEBUG_PREEMPT, as this *really* hurts performance
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

On arm64 the TTBR0_EL1 register is set to either the reserved TTBR0
page tables on boot or to the active_mm mappings belonging to user space
processes, it must never be set to swapper_pg_dir page tables mappings.

When a CPU is booted its active_mm is set to init_mm even though its
TTBR0_EL1 points at the reserved TTBR0 page mappings. This implies
that when __cpu_suspend is triggered the active_mm can point at
init_mm even if the current TTBR0_EL1 register contains the reserved
TTBR0_EL1 mappings.

Therefore, the mm save and restore executed in __cpu_suspend might
turn out to be erroneous in that, if the current->active_mm corresponds
to init_mm, on resume from low power it ends up restoring in the
TTBR0_EL1 the init_mm mappings that are global and can cause speculation
of TLB entries which end up being propagated to user space.

This patch fixes the issue by checking the active_mm pointer before
restoring the TTBR0 mappings. If the current active_mm == &init_mm,
the code sets the TTBR0_EL1 to the reserved TTBR0 mapping instead of
switching back to the active_mm, which is the expected behaviour
corresponding to the TTBR0_EL1 settings when __cpu_suspend was entered.

Fixes: 95322526 ("arm64: kernel: cpu_{suspend/resume} implementation")
Cc: <stable@vger.kernel.org> # 3.14+: 18ab7db6
Cc: <stable@vger.kernel.org> # 3.14+: 714f5992
Cc: <stable@vger.kernel.org> # 3.14+: c3684fbb
Cc: <stable@vger.kernel.org> # 3.14+
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

- Remove soon-to-be-dead @redhat address.
- Jeff Hartmann wrote the bulk of the original backend code, and should
  at least get a mention in the MODULE_AUTHOR for backend.o
- Various people at Intel have done a lot more work than myself on the
  intel-* drivers, so again, mention that.
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Pull device mapper fixes from Mike Snitzer:
 "Thre stable fixes and one fix for a regression introduced during 3.19
  merge:

   - Fix inability to discard used space when the thin-pool target is in
     out-of-data-space mode and also transition the thin-pool back to
     write mode once free space is made available.

   - Fix DM core bio-based end_io bug that prevented proper
     post-processing of the error code returned from the block layer.

   - Fix crash in DM thin-pool due to thin device being added to the
     pool's active_thins list before properly initializing the thin
     device's refcount"

* tag 'dm-3.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: fix missed error code if .end_io isn't implemented by target_type
  dm thin: fix crash by initializing thin device's refcount and completion earlier
  dm thin: fix missing out-of-data-space to write mode transition if blocks are released
  dm thin: fix inability to discard blocks when in out-of-data-space mode

This reverts commit c8475d14.

There are several[1][2] of bug reports which points to this commit as potential
cause[3].

Let's revert it until we figure out what's going on.

[1] https://lkml.org/lkml/2014/11/14/342
[2] https://lkml.org/lkml/2014/12/22/213
[3] https://lkml.org/lkml/2014/12/9/741Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/tegra: Fixes for v3.19-rc1

This is a set of fixes for two regressions and one bug in the IOMMU
mapping code. It turns out that all of these issues turn up primarily
on Tegra30 hardware. The IOMMU mapping bug only manifests on buffers
that aren't multiples of the page size. I happened to be testing HDMI
with 1080p while writing the code and framebuffers for that happen to
fit exactly within 2025 pages of 4 KiB each.

One of the regressions is caused by the IOMMU code allocating pages from
shmem which can have associated cache lines. If the pages aren't flushed
then these cache lines may be flushed later on and cause framebuffer
corruption. I'm not sure why I didn't see this before. Perhaps the board
that I was using had enough RAM so that the pages shmem would hand out
had a better chance of being unused. Or maybe I didn't look too closely.
The fix for this is to fake up an SG table so that it can be passed to
the DMA API. Ideally this would use drm_clflush_*(), but implementing
that for ARM causes DRM to fail to build as a module since some of the
low-level cache maintenance functions aren't exported. Hopefully we can
get a suitable API exported on ARM for the next release.

The second regression is caused by a mismatch between the hardware pipe
number and the CRTC's DRM index. These were used inconsistently, which
could cause one code location to call drm_vblank_get() with a different
pipe than the corresponding drm_vblank_put(), thereby causing the
reference count to become unbalanced. Alexandre also reported a possible
race condition related to this, which this series also fixes.

* tag 'drm/tegra/for-3.19-rc1-fixes' of git://people.freedesktop.org/~tagr/linux:
  drm/tegra: dc: Select root window for event dispatch
  drm/tegra: gem: Use the proper size for GEM objects
  drm/tegra: gem: Flush buffer objects upon allocation
  drm/tegra: dc: Fix a potential race on page-flip completion
  drm/tegra: dc: Consistently use the same pipe
  drm/irq: Add drm_crtc_vblank_count()
  drm/irq: Add drm_crtc_handle_vblank()
  drm/irq: Add drm_crtc_send_vblank_event()

Merge tag 'drm-intel-next-fixes-2014-12-17' of git://anongit.freedesktop.org/drm-intel into drm-fixes

misc i915 fixes.

* tag 'drm-intel-next-fixes-2014-12-17' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Disable PSMI sleep messages on all rings around context switches
  drm/i915: Force the CS stall for invalidate flushes
  drm/i915: Invalidate media caches on gen7
  drm/i915: sanitize RPS resetting during GPU reset
  drm/i915: move RPS PM_IER enabling to gen6_enable_rps_interrupts
  drm/i915: vlv: fix IRQ masking when uninstalling interrupts

Yeah a pull for one patch is a bit overkill but I started to assemble the
various patches for 3.20 in a branch for atomic props/ioctl and didn't
realize that this bugfix here at the beginnning of the branch should be in
3.19 (because msm is using the helpers arleady). So if you'd merge we'd
have it twice or or I need to shuffle branches again. Can do if you want.

* tag 'topic/atomic-fixes-2014-12-17' of git://anongit.freedesktop.org/drm-intel:
  drm/atomic: fix potential null ptr on plane enable

A few msm fixes for 3.19:
 * hdmi regulators fix
 * hdmi fix for spurious HPD interrupts
 * fix for sync atomic update after async update (which could show
   up with a setcrtc following a pageflip)
 * couple little Coccinelle cleanups

* 'msm-fixes-3.19' of git://people.freedesktop.org/~robclark/linux:
  drm/msm/hdmi: rework HDMI IRQ handler
  drm/msm/hdmi: enable regulators before clocks to avoid warnings
  drm/msm/mdp5: update irqs on crtc<->encoder link change
  drm/msm: block incoming update on pending updates
  drm/msm: Deletion of unnecessary checks before the function call "release_firmware"
  drm/msm: Deletion of unnecessary checks before two function calls

nouveau userspace back at 1.0.1 used to call the X server
DRIOpenDRMMaster interface even for DRI2 (doh!), this attempts
to map the sarea and fails if it can't.

Since 884c6dab from Daniel,
this fails, but only ancient drivers would see it.

Revert the nouveau bits of that fix.
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: <stable@vger.kernel.org>  # 3.18
Signed-off-by: Dave Airlie <airlied@redhat.com>

There is a problem with the audit system when multiple audit records
are created for the same path, each with a different path name type.
The root cause of the problem is in __audit_inode() when an exact
match (both the path name and path name type) is not found for a
path name record; the existing code creates a new path name record,
but it never sets the path name in this record, leaving it NULL.
This patch corrects this problem by assigning the path name to these
newly created records.

There are many ways to reproduce this problem, but one of the
easiest is the following (assuming auditd is running):

  # mkdir /root/tmp/test
  # touch /root/tmp/test/567
  # auditctl -a always,exit -F dir=/root/tmp/test
  # touch /root/tmp/test/567

Afterwards, or while the commands above are running, check the audit
log and pay special attention to the PATH records.  A faulty kernel
will display something like the following for the file creation:

  type=SYSCALL msg=audit(1416957442.025:93): arch=c000003e syscall=2
    success=yes exit=3 ... comm="touch" exe="/usr/bin/touch"
  type=CWD msg=audit(1416957442.025:93):  cwd="/root/tmp"
  type=PATH msg=audit(1416957442.025:93): item=0 name="test/"
    inode=401409 ... nametype=PARENT
  type=PATH msg=audit(1416957442.025:93): item=1 name=(null)
    inode=393804 ... nametype=NORMAL
  type=PATH msg=audit(1416957442.025:93): item=2 name=(null)
    inode=393804 ... nametype=NORMAL

While a patched kernel will show the following:

  type=SYSCALL msg=audit(1416955786.566:89): arch=c000003e syscall=2
    success=yes exit=3 ... comm="touch" exe="/usr/bin/touch"
  type=CWD msg=audit(1416955786.566:89):  cwd="/root/tmp"
  type=PATH msg=audit(1416955786.566:89): item=0 name="test/"
    inode=401409 ... nametype=PARENT
  type=PATH msg=audit(1416955786.566:89): item=1 name="test/567"
    inode=393804 ... nametype=NORMAL

This issue was brought up by a number of people, but special credit
should go to hujianyang@huawei.com for reporting the problem along
with an explanation of the problem and a patch.  While the original
patch did have some problems (see the archive link below), it did
demonstrate the problem and helped kickstart the fix presented here.

  * https://lkml.org/lkml/2014/9/5/66Reported-by: hujianyang <hujianyang@huawei.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>

Commit a3a60f81 (dma-mapping: replace set_arch_dma_coherent_ops with
arch_setup_dma_ops) changes the of_dma_configure() arch dma_ops callback
to arch_setup_dma_ops but only the arch/arm code is updated. Subsequent
commit 97890ba9 (dma-mapping: detect and configure IOMMU in
of_dma_configure) changes the arch_setup_dma_ops() prototype further to
handle iommu. The patch makes the corresponding arm64 changes.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Will Deacon <will.deacon@arm.com>