Pull VFS fixes from Al Viro:
 "A bunch of assorted fixes, most of them followups to overlayfs merge"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ovl: initialize ->is_cursor
  Return short read or 0 at end of a raw device, not EIO
  isofs: don't bother with ->d_op for normal case
  isofs_cmp(): we'll never see a dentry for . or ..
  overlayfs: fix lockdep misannotation
  ovl: fix check for cursor
  overlayfs: barriers for opening upper-layer directory
  rcu: Provide counterpart to rcu_dereference() for non-RCU situations
  staging: android: logger: Fix log corruption regression

As a follow-up to commit 6cab7a37f5c04 ("staging: comedi: (regression)
channel list must be set for COMEDI_CMD ioctl"), Hartley Sweeten pointed
out another couple of bugs stemming from commit 6cab7a37f5c04 ("staging:
comedi: comedi_fops: introduce __comedi_get_user_chanlist()").

Firstly, `do_cmdtest_ioctl()` never frees the kernel copy of the user
chanlist allocated by `__comedi_get_user_chanlist()`, so that memory is
leaked.  Fix it by freeing the allocated kernel memory pointed to by
`cmd.chanlist` before that pointer is overwritten with its original
pointer to user memory before `cmd` is copied back to user-space.

Secondly, if `__comedi_get_user_chanlist()` returns an error,
`cmd->chanlist` is left unchanged and in fact will be a pointer to user
memory.  This causes `do_cmd_ioctl()` to `goto cleanup` and call
`do_become_nonbusy()` which would attempt to free the memory pointed to
by the user-space pointer.  Fix it by setting `cmd->chanlist` to NULL at
the start of `__comedi_get_user_chanlist()`.

Fixes: c6cd0eefb27b ("staging: comedi: comedi_fops: introduce __comedi_get_user_chanlist()")
Reported-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: <stable@vger.kernel.org> # 3.15.y 3.16.y 3.17.y: 6cab7a37f5c04
Cc: <stable@vger.kernel.org> # 3.15.y 3.16.y 3.17.y

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

A merge conflict between commits
fbfd9c8a1782f33d7b67294b2a42587063e61c0c ("staging: comedi:
addi_apci_3120: use dma_alloc_coherent()") and
aff5b1f8eb71b64bb613dc64c50b6904e89f79b9 ("staging: comedi: remove
comedi_fc module") left the COMEDI_ADDI_APCI_3120 config option
depending on VIRT_TO_BUS when it no longer needs to do so.  The
dependency was removed by the first commit and accidentally reinstated
by the second commit.  Remove the dependency again.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For the `COMEDI_LOCK`, `COMEDI_UNLOCK`, `COMEDI_CANCEL`, and
`COMEDI_POLL` ioctls the third argument is a comedi subdevice number.
This is passed as an `unsigned long`, but when it is passed down to the
ioctl command-specific handler functions `do_lock_ioctl()`,
`do_unlock_ioctl()`, `do_cancel_ioctl()`, and `do_poll_ioctl()`, the
value has been narrowed to an `unsigned int`.  Pass through the argument
as an `unsigned long` to avoid truncating the value on 64-bit
architectures.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit cd678fce4280 ("switch logger to ->write_iter()"), any
attempt to write to the log results in the log data being written over
its own metadata, thus rendering the log unreadable.

The problem was first detected when I ran an Android userspace on the
v3.18-rc1 kernel. However the issue can also be observed with a
non-Android userspace by using echo/cat to write to/from /dev/log_main .

This patch resolves the problem by using a temporary to track the status
of not-yet-committed writes to the log buffer.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Jonathan writes:

First round of IIO fixes for the 3.18 cycle.

* ad5933 - fix a null pointer dereference due to an old change that prevents
  different channels being registered for the buffer and used for sysfs
  interfaces.
* ad5933 - Drop a bonus _raw from attribute names.
* st-sensors - Makes sure the correct number of elements are copied when
  filling a local buffer copy.
* mxs-lradc - Disable clocks in a failure path during probe so they aren't
  left running.

Make sure struct eeprom_priv->mac_addr is 2 byte aligned to work with
ether_addr_copy()

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

COMEDI_II_PCI20KC needs HAS_IOMEM, so depend on it. The related error (
with allmodconfig under um):

    CC [M]  drivers/staging/comedi/drivers/ii_pci20kc.o
  drivers/staging/comedi/drivers/ii_pci20kc.c: In function ‘ii20k_attach’:
  drivers/staging/comedi/drivers/ii_pci20kc.c:442:2: error: implicit declaration of function ‘ioremap’ [-Werror=implicit-function-declaration]
    dev->mmio = ioremap(membase, II20K_SIZE);
    ^
  drivers/staging/comedi/drivers/ii_pci20kc.c:442:12: warning: assignment makes pointer from integer without a cast [enabled by default]
    dev->mmio = ioremap(membase, II20K_SIZE);
              ^
  drivers/staging/comedi/drivers/ii_pci20kc.c: In function ‘ii20k_detach’:
  drivers/staging/comedi/drivers/ii_pci20kc.c:512:3: error: implicit declaration of function ‘iounmap’ [-Werror=implicit-function-declaration]
     iounmap(dev->mmio);
     ^

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

`do_cmd_ioctl()`, the handler for the `COMEDI_CMD` ioctl can incorrectly
call the Comedi subdevice's `do_cmd()` handler with a NULL channel list
pointer.  This is a regression as the `do_cmd()` handler has never been
expected to deal with that, leading to a kernel OOPS when it tries to
dereference it.

A NULL channel list pointer is allowed for the `COMEDI_CMDTEST` ioctl,
handled by `do_cmdtest_ioctl()` and the subdevice's `do_cmdtest()`
handler, but not for the `COMEDI_CMD` ioctl and its handlers.

Both `do_cmd_ioctl()` and `do_cmdtest_ioctl()` call
`__comedi_get_user_chanlist()` to copy the channel list from user memory
into dynamically allocated kernel memory and check it for consistency.
That function currently returns 0 if the `user_chanlist` parameter
(pointing to the channel list in user memory) is NULL.  That's fine for
`do_cmdtest_ioctl()`, but `do_cmd_ioctl()` incorrectly assumes the
kernel copy of the channel list has been set-up correctly.

Fix it by not allowing the `user_chanlist` parameter to be NULL in
`__comedi_get_user_chanlist()`, and only calling it from
`do_cmdtest_ioctl()` if the parameter is non-NULL.

Thanks to Bernd Porr for reporting the bug via an initial patch sent
privately.

Fixes: c6cd0eefb27b ("staging: comedi: comedi_fops: introduce __comedi_get_user_chanlist()")
Reported-by: Bernd Porr <mail@berndporr.me.uk>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Bernd Porr <mail@berndporr.me.uk>
Cc: <stable@vger.kernel.org> # 3.15.y 3.16.y 3.17.y
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull drm updates from Dave Airlie:
 "This is the main git pull for the drm,

  I pretty much froze major pulls at -rc5/6 time, and haven't had much
  fallout, so will probably continue doing that.

  Lots of changes all over, big internal header cleanup to make it clear
  drm features are legacy things and what are things that modern KMS
  drivers should be using.  Also big move to use the new generic fences
  in all the TTM drivers.

  core:
        atomic prep work,
        vblank rework changes, allows immediate vblank disables
        major header reworking and cleanups to better delinate legacy
        interfaces from what KMS drivers should be using.
        cursor planes locking fixes

  ttm:
        move to generic fences (affects all TTM drivers)
        ppc64 caching fixes

  radeon:
        userptr support,
        uvd for old asics,
        reset rework for fence changes
        better buffer placement changes,
        dpm feature enablement
        hdmi audio support fixes

  intel:
        Cherryview work,
        180 degree rotation,
        skylake prep work,
        execlist command submission
        full ppgtt prep work
        cursor improvements
        edid caching,
        vdd handling improvements

  nouveau:
        fence reworking
        kepler memory clock work
        gt21x clock work
        fan control improvements
        hdmi infoframe fixes
        DP audio

  ast:
        ppc64 fixes
        caching fix

  rcar:
        rcar-du DT support

  ipuv3:
        prep work for capture support

  msm:
        LVDS support for mdp4, new panel, gpu refactoring

  exynos:
        exynos3250 SoC support, drop bad mmap interface,
        mipi dsi changes, and component match support"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (640 commits)
  drm/mst: rework payload table allocation to conform better.
  drm/ast: Fix HW cursor image
  drm/radeon/kv: add uvd/vce info to dpm debugfs output
  drm/radeon/ci: add uvd/vce info to dpm debugfs output
  drm/radeon: export reservation_object from dmabuf to ttm
  drm/radeon: cope with foreign fences inside the reservation object
  drm/radeon: cope with foreign fences inside display
  drm/core: use helper to check driver features
  drm/radeon/cik: write gfx ucode version to ucode addr reg
  drm/radeon/si: print full CS when we hit a packet 0
  drm/radeon: remove unecessary includes
  drm/radeon/combios: declare legacy_connector_convert as static
  drm/radeon/atombios: declare connector convert tables as static
  drm/radeon: drop btc_get_max_clock_from_voltage_dependency_table
  drm/radeon/dpm: drop clk/voltage dependency filters for BTC
  drm/radeon/dpm: drop clk/voltage dependency filters for CI
  drm/radeon/dpm: drop clk/voltage dependency filters for SI
  drm/radeon/dpm: drop clk/voltage dependency filters for NI
  drm/radeon: disable audio when we disable hdmi (v2)
  drm/radeon: split audio enable between eg and r600 (v2)
  ...