xen-blkback: implement safe iterator for the list of persistent grants

Change foreach_grant iterator to a safe version, that allows freeing
the element while iterating. Also move the free code in
free_persistent_gnts to prevent freeing the element before the rb_next
call.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
HID: remove x bit from sensor doc

Reported-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
llist/xen-blkfront: implement safe version of llist_for_each_entry

Implement a safe version of llist_for_each_entry, and use it in
blkif_free. Previously grants where freed while iterating the list,
which lead to dereferences when trying to fetch the next item.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by:  Andrew Morton <akpm@linux-foundation.org>
[v2: Move the llist_for_each_entry_safe in llist.h]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
xen-blkfront: handle bvecs with partial data

Currently blkfront fails to handle cases in blkif_completion like the
following:

1st loop in rq_for_each_segment
 * bv_offset: 3584
 * bv_len: 512
 * offset += bv_len
 * i: 0

2nd loop:
 * bv_offset: 0
 * bv_len: 512
 * i: 0

In the second loop i should be 1, since we assume we only wanted to
read a part of the previous page. This patches fixes this cases where
only a part of the shared page is read, and blkif_completion assumes
that if the bv_offset of a bvec is less than the previous bv_offset
plus the bv_size we have to switch to the next shared page.

Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: linux-kernel@vger.kernel.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
block: remove deadlock in disk_clear_events

In disk_clear_events, do not put work on system_nrt_freezable_wq.
Instead, put it on system_nrt_wq.

There is a race between probing a usb and suspending the device.  Since
probing a usb calls disk_clear_events, which puts work on a frozen
workqueue, probing cannot finish after the workqueue is frozen.  However,
suspending cannot finish until the usb probe is finished, so we get a
deadlock, causing the system to reboot.

The way to reproduce this bug is to wake up from suspend with a usb
storage device plugged in, or plugging in a usb storage device right
before suspend.  The window of time is on the order of time it takes to
probe the usb device.  As long as the workqueues are frozen before the
call to add_disk within sd_probe_async finishes, there will be a deadlock
(which calls blkdev_get, sd_open, check_disk_change, then
disk_clear_events).  This is not difficult to reproduce after figuring out
the timings.

[akpm@linux-foundation.org: fix up comment]
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: prevent race/cleanup

Remove a race condition which causes a warning in disk_clear_events.  This
is a race between disk_clear_events() and disk_flush_events().
ev->clearing will be altered by disk_flush_events() even though we are
blocking event checking through disk_flush_events().  If this happens
after ev->clearing was cleared for disk_clear_events(), this can cause the
WARN_ON_ONCE() in that function to be triggered.

This change also has disk_clear_events() not go through a workqueue.
Since we have to wait for the work to complete, we should just call the
function directly.  Also, since this work cannot be put on a freezable
workqueue, it will have to contend with increased demand, so calling the
function directly avoids this.

[akpm@linux-foundation.org: fix spello in comment]
Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Merge branch 'stable/for-jens-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-linus

Konrad writes:

Please git pull the following branch:

 git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/for-jens-3.8

which has a bug-fix to the xen-blkfront and xen-blkback driver
when using the persistent mode. An issue was discovered where LVM
disks could not be read correctly and this fixes it. There
is also a change in llist.h which has been blessed by akpm.
[media] gspca_kinect: add Kinect for Windows USB id

Add the USB ID for the Kinect for Windows RGB camera so it can be used
with the gspca_kinect driver.

Signed-off-by: Jacob Schloss <jacob.schloss@unlimitedautomata.com>
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
[media] gspca_sonixb: Properly wait between i2c writes

We must wait for the previous i2c write to complete before starting a new
one. Sofar we were getting away with this, but it seems that some parts
of the usb-subsystem has been sped up making us go to fast :)
This fixes streaming on sn9c103 based cams not working with an
"i2c_w error" error.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
[media] gspca_sonixj: Add a small delay after i2c_w1

We already have the same delay in i2c_w8, but it was missing from i2c_w1,
adding this delay fixes the Microsoft VX-3000 camera often (but not always)
streaming video data with a very green-ish tint.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
mtd: bcm47xxnflash: increase NFLASH_READY_RETRIES

Recently imlemented writing support has shown that current num of
retries is too low. Writing requires longer waiting than simple reading.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
m68k: Provide dma_alloc_attrs()/dma_free_attrs()

Since commit 0049fb2603b7afb1080776ee691dfa5a3d282357 ("OMAPFB: use
dma_alloc_attrs to allocate memory") we have one non-arch user of
dma_{alloc,free}_attrs().

Hence provide these functions, as wrappers around
dma_{alloc,free}_coherent().

Note that most architectures do it the other way around. But as so far
m68k doesn't support the attributes at all, our solution should generate
smaller code.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
asm-generic/dma-mapping-broken.h: Provide dma_alloc_attrs()/dma_free_attrs()

Since commit 0049fb2603b7afb1080776ee691dfa5a3d282357 ("OMAPFB: use
dma_alloc_attrs to allocate memory") we have one non-arch user of
dma_{alloc,free}_attrs().

Hence provide these functions, as wrappers around
dma_{alloc,free}_coherent().

Note that most architectures do it the other way around. But as these are
dummy functions, we don't care.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
m68k: Wire up finit_module

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Ensure that kernel_init_freeable() is not inlined into non __init code

Commit d6b2123802d "make sure that we always have a return path from
kernel_execve()" reshuffled kernel_init()/init_post() to ensure that
kernel_execve() has a caller to return to.

It removed __init annotation for kernel_init() and introduced/calls a
new routine kernel_init_freeable(). Latter however is inlined by any
reasonable compiler (ARC gcc 4.4 in this case), causing slight code
bloat.

This patch forces kernel_init_freeable() as noinline reducing the .text

bloat-o-meter vmlinux vmlinux_new
add/remove: 1/0 grow/shrink: 0/1 up/down: 374/-334 (40)
function                        old     new   delta
kernel_init_freeable              -     374    +374 (.init.text)
kernel_init                     628     294    -334 (.text)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
CONFIG_GENERIC_SIGALTSTACK build breakage with asm-generic/syscalls.h

Saner transition plan for GENERIC_SIGALTSTACK conversion - instead of
adding #define sys_sigaltstack sys_sigaltstack in asm/syscalls.h of
architecture if it's pulls asm-generic/syscalls.h, only to have those
defines removed once all architectures are converted, make the
declaration in said asm-generic/syscalls.h conditional on the lack
of GENERIC_SIGALTSTACK.  Less messy in intermediate stages that way...

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: james.hogan@imgtec.com
Cc: arnd@arndb.de
Cc: torvalds@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINE

Makes sigaltstack conversion easier to split into per-architecture
parts.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINE

Strictly speaking, ppc64 needs it for C ABI compliance.  Realistically
I would be very surprised if e.g. passing 0xffffffff as 'options'
argument to waitid() from 32bit task would cause problems, but yes,
it puts us into undefined behaviour territory.  ppc64 expects int
argument to be passed in 64bit register with bits 31..63 containing
the same value.  SYSCALL_DEFINE on ppc provides a wrapper that normalizes
the value passed from userland; so does COMPAT_SYSCALL_DEFINE.  Plain
declaration of compat_sys_something() with an int argument obviously
doesn't.  Again, for wait4 and waitid I would be extremely surprised
if gcc started to produce code depending on that value having been
properly sign-extended - the argument(s) in question end up passed
blindly to sys_wait4 and sys_waitid resp. and normalization for native
syscalls takes care of their use there.  Still, better to use
COMPAT_SYSCALL_DEFINE here than worry about nasal daemons...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
x32: fix waitid()

It needs 64bit rusage and 32bit siginfo.  glibc never calls it with
non-NULL rusage pointer, or we would've seen breakage already...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
x32: fix sigtimedwait

It needs 64bit timespec.  As it is, we end up truncating the timeout
to whole seconds; usually it doesn't matter, but for having all
sub-second timeouts truncated to one jiffy is visibly wrong.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>