If we mount a hierarchy with a specified name, the name is unique,
and we can use it to mount the hierarchy without specifying its
set of subsystem names. This feature is documented is
Documentation/cgroups/cgroups.txt section 2.3

Here's an example:

	# mount -t cgroup -o cpuset,name=myhier xxx /cgroup1
	# mount -t cgroup -o name=myhier xxx /cgroup2

But it was broken by commit 32a8cf23
(cgroup: make the mount options parsing more accurate)

This fixes the regression.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

Gcc complains about this: "kernel/cgroup.c:2179:4: warning: suggest
parentheses around assignment used as truth value [-Wparentheses]"
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

cgroup_post_fork() is protected between threadgroup_change_begin()
and threadgroup_change_end() against concurrent changes of the
child's css_set in cgroup_task_migrate(). Also the child can't
exit and call cgroup_exit() at this stage, this means it's css_set
can't be changed with init_css_set concurrently.

For these reasons, we don't need to hold task_lock() on the child
because it's css_set can only remain stable in this place.

Let's remove the lock there.

v2: Update comment to explain that we are safe against
cgroup_exit()
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Containers <containers@lists.linux-foundation.org>
Cc: Cgroups <cgroups@vger.kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Mandeep Singh Baines <msb@chromium.org>

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

In cgroup_attach_proc it is now sufficient to only check that
oldcgrp==newcgrp once. Now that we are using threadgroup_lock()
during the migrations, oldcgrp will not change.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>

threadgroup_lock() guarantees that the target threadgroup will
remain stable - no new task will be added, no new PF_EXITING
will be set and exec won't happen.

Changes in V2:
* https://lkml.org/lkml/2011/12/20/369 (Tejun Heo)
  * Undo incorrect removal of get/put from attach_task_by_pid()
* Author
  * Remove a comment which is made stale by this change
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>

We can now assume that the css_set reference held by the task
will not go away for an exiting task. PF_EXITING state can be
trusted throughout migration by checking it after locking
threadgroup.

Changes in V4:
* https://lkml.org/lkml/2011/12/20/368 (Tejun Heo)
  * Fix typo in commit message
  * Undid the rename of css_set_check_fetched
* https://lkml.org/lkml/2011/12/20/427 (Li Zefan)
  * Fix comment in cgroup_task_migrate()
Changes in V3:
* https://lkml.org/lkml/2011/12/20/255 (Frederic Weisbecker)
  * Fixed to put error in retval
Changes in V2:
* https://lkml.org/lkml/2011/12/19/289 (Tejun Heo)
  * Updated commit message

-tj: removed stale patch description about dropped function rename.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>

When we fetch the css_set of the tasks on cgroup migration, we don't need
anymore to synchronize against cgroup_exit() that could swap the old one
with init_css_set. Now that we are using threadgroup_lock() during
the migrations, we don't need to worry about it anymore.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Containers <containers@lists.linux-foundation.org>
Cc: Cgroups <cgroups@vger.kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>

We don't need to hold the parent task_lock() on the
parent in cgroup_fork() because we are already synchronized
against the two places that may change the parent css_set
concurrently:

- cgroup_exit(), but the parent obviously can't exit concurrently
- cgroup migration: we are synchronized against threadgroup_lock()

So we can safely remove the task_lock() there.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Containers <containers@lists.linux-foundation.org>
Cc: Cgroups <cgroups@vger.kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Mandeep Singh Baines <msb@chromium.org>

We already have a reference to all elements in newcg_list.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: Paul Menage <paul@paulmenage.org>

The memparse() function already accepts const char * as the parsing string.
Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

These three methods are no longer used.  Kill them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Menage <paul@paulmenage.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>

->pre_attach() is supposed to be called before migration, which is
observed during process migration but task migration does it the other
way around.  The only ->pre_attach() user is cpuset which can do the
same operaitons in ->can_attach().  Collapse cpuset_pre_attach() into
cpuset_can_attach().

-v2: Patch contamination from later patch removed.  Spotted by Paul
     Menage.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Menage <paul@paulmenage.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>

Now that subsys->can_attach() and attach() take @tset instead of
@task, they can handle per-task operations.  Convert
->can_attach_task() and ->attach_task() users to use ->can_attach()
and attach() instead.  Most converions are straight-forward.
Noteworthy changes are,

* In cgroup_freezer, remove unnecessary NULL assignments to unused
  methods.  It's useless and very prone to get out of sync, which
  already happened.

* In cpuset, PF_THREAD_BOUND test is checked for each task.  This
  doesn't make any practical difference but is conceptually cleaner.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: James Morris <jmorris@namei.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>

Currently, there's no way to pass multiple tasks to cgroup_subsys
methods necessitating the need for separate per-process and per-task
methods.  This patch introduces cgroup_taskset which can be used to
pass multiple tasks and their associated cgroups to cgroup_subsys
methods.

Three methods - can_attach(), cancel_attach() and attach() - are
converted to use cgroup_taskset.  This unifies passed parameters so
that all methods have access to all information.  Conversions in this
patchset are identical and don't introduce any behavior change.

-v2: documentation updated as per Paul Menage's suggestion.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Menage <paul@paulmenage.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: James Morris <jmorris@namei.org>

cgroup_attach_proc() behaves differently from cgroup_attach_task() in
the following aspects.

* All hooks are invoked even if no task is actually being moved.

* ->can_attach_task() is called for all tasks in the group whether the
  new cgrp is different from the current cgrp or not; however,
  ->attach_task() is skipped if new equals new.  This makes the calls
  asymmetric.

This patch improves old cgroup handling in cgroup_attach_proc() by
looking up the current cgroup at the head, recording it in the flex
array along with the task itself, and using it to remove the above two
differences.  This will also ease further changes.

-v2: nr_todo renamed to nr_migrating_tasks as per Paul Menage's
     suggestion.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Menage <paul@paulmenage.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>

Update cgroup to take advantage of the fack that threadgroup_lock()
guarantees stable threadgroup.

* Lock threadgroup even if the target is a single task.  This
  guarantees that when the target tasks stay stable during migration
  regardless of the target type.

* Remove PF_EXITING early exit optimization from attach_task_by_pid()
  and check it in cgroup_task_migrate() instead.  The optimization was
  for rather cold path to begin with and PF_EXITING state can be
  trusted throughout migration by checking it after locking
  threadgroup.

* Don't add PF_EXITING tasks to target task array in
  cgroup_attach_proc().  This ensures that task migration is performed
  only for live tasks.

* Remove -ESRCH failure path from cgroup_task_migrate().  With the
  above changes, it's guaranteed to be called only for live tasks.

After the changes, only live tasks are migrated and they're guaranteed
to stay alive until migration is complete.  This removes problems
caused by exec and exit racing against cgroup migration including
symmetry among cgroup attach methods and different cgroup methods
racing each other.

v2: Oleg pointed out that one more PF_EXITING check can be removed
    from cgroup_attach_proc().  Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>

threadgroup_lock() protected only protected against new addition to
the threadgroup, which was inherently somewhat incomplete and
problematic for its only user cgroup.  On-going migration could race
against exec and exit leading to interesting problems - the symmetry
between various attach methods, task exiting during method execution,
->exit() racing against attach methods, migrating task switching basic
properties during exec and so on.

This patch extends threadgroup_lock() such that it protects against
all three threadgroup altering operations - fork, exit and exec.  For
exit, threadgroup_change_begin/end() calls are added to exit_signals
around assertion of PF_EXITING.  For exec, threadgroup_[un]lock() are
updated to also grab and release cred_guard_mutex.

With this change, threadgroup_lock() guarantees that the target
threadgroup will remain stable - no new task will be added, no new
PF_EXITING will be set and exec won't happen.

The next patch will update cgroup so that it can take full advantage
of this change.

-v2: beefed up comment as suggested by Frederic.

-v3: narrowed scope of protection in exit path as suggested by
     Frederic.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>

Make the following renames to prepare for extension of threadgroup
locking.

* s/signal->threadgroup_fork_lock/signal->group_rwsem/
* s/threadgroup_fork_read_lock()/threadgroup_change_begin()/
* s/threadgroup_fork_read_unlock()/threadgroup_change_end()/
* s/threadgroup_fork_write_lock()/threadgroup_lock()/
* s/threadgroup_fork_write_unlock()/threadgroup_unlock()/

This patch doesn't cause any behavior change.

-v2: Rename threadgroup_change_done() to threadgroup_change_end() per
     KAMEZAWA's suggestion.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>

cgroup wants to make threadgroup stable while modifying cgroup
hierarchies which will introduce locking dependency on
cred_guard_mutex from cgroup_mutex.  This unfortunately completes
circular dependency.

 A. cgroup_mutex -> cred_guard_mutex -> s_type->i_mutex_key -> namespace_sem
 B. namespace_sem -> cgroup_mutex

B is from cgroup_show_options() and this patch breaks it by
introducing another mutex cgroup_root_mutex which nests inside
cgroup_mutex and protects cgroupfs_root.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>

At present, the functions freezer_count() and freezer_do_not_count()
impose the restriction that they are effective only for userspace processes.
However, now, these functions have found more utility than originally
intended by the commit which introduced it: ba96a0c8 (freezer:
fix vfork problem). And moreover, even the vfork issue actually does not
need the above restriction in these functions.

So, modify these functions to make them work even for kernel threads, so
that they can be used at other places in the kernel, where the userspace
restriction doesn't apply.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Allow the freezer to skip wait_on_bit_killable sleeps in the sunrpc
layer. This should allow suspend and hibernate events to proceed, even
when there are RPC's pending on the wire.

Also, wrap the TASK_KILLABLE sleeps in NFS layer in freezer_do_not_count
and freezer_count calls. This allows the freezer to skip tasks that are
sleeping while looping on EJUKEBOX or NFS4ERR_DELAY sorts of errors.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Commit 944e192db53c "freezer: rename thaw_process() to __thaw_task()
and simplify the implementation" did not create a !CONFIG_FREEZER version
of __thaw_task().
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

* 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc: (24 commits)
  freezer: fix wait_event_freezable/__thaw_task races
  freezer: kill unused set_freezable_with_signal()
  dmatest: don't use set_freezable_with_signal()
  usb_storage: don't use set_freezable_with_signal()
  freezer: remove unused @sig_only from freeze_task()
  freezer: use lock_task_sighand() in fake_signal_wake_up()
  freezer: restructure __refrigerator()
  freezer: fix set_freezable[_with_signal]() race
  freezer: remove should_send_signal() and update frozen()
  freezer: remove now unused TIF_FREEZE
  freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE
  cgroup_freezer: prepare for removal of TIF_FREEZE
  freezer: clean up freeze_processes() failure path
  freezer: kill PF_FREEZING
  freezer: test freezable conditions while holding freezer_lock
  freezer: make freezing indicate freeze condition in effect
  freezer: use dedicated lock instead of task_lock() + memory barrier
  freezer: don't distinguish nosig tasks on thaw
  freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks
  freezer: rename thaw_process() to __thaw_task() and simplify the implementation
  ...

The hibernation core code forgets to release memory preallocated
for hibernation if there's an error in its early stages or if test
modes causing hibernation_snapshot() to return early are used.  This
causes the system to be hardly usable, because the amount of
preallocated memory is usually huge.  Fix this problem.
Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest:
  ktest: Check parent options for iterated tests

* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  i2c: Make i2cdev_notifier_call static
  i2c: Delete ANY_I2C_BUS
  i2c: Fix device name for 10-bit slave address
  i2c-algo-bit: Generate correct i2c address sequence for 10-bit target

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: TPS65910: Fix VDD1/2 voltage selector count

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (31 commits)
  drm: integer overflow in drm_mode_dirtyfb_ioctl()
  drivers/gpu/vga/vgaarb.c: add missing kfree
  drm/radeon/kms/atom: unify i2c gpio table handling
  drm/radeon/kms: fix up gpio i2c mask bits for r4xx for real
  ttm: Don't return the bo reserved on error path
  drm/radeon/kms: add a CS ioctl flag not to rewrite tiling flags in the CS
  drm/i915: Fix inconsistent backlight level during disabled
  drm, i915: Fix memory leak in i915_gem_busy_ioctl().
  drm/i915: Use DPCD value for max DP lanes.
  drm/i915: Initiate DP link training only on the lanes we'll be using
  drm/i915: Remove trailing white space
  drm/i915: Try harder during dp pattern 1 link training
  drm/i915: Make DP prepare/commit consistent with DP dpms
  drm/i915: Let panel power sequencing hardware do its job
  drm/i915: Treat PCH eDP like DP in most places
  drm/i915: Remove link_status field from intel_dp structure
  drm/i915: Move common PCH_PP_CONTROL setup to ironlake_get_pp_control
  drm/i915: Module parameters using '-1' as default must be signed type
  drm/i915: Turn on another required clock gating bit on gen6.
  drm/i915: Turn on a required 3D clock gating bit on Sandybridge.
  ...

wait_event_freezable() and friends stop the waiting if try_to_freeze()
fails. This is not right, we can race with __thaw_task() and in this
case

	- wait_event_freezable() returns the wrong ERESTARTSYS

	- wait_event_freezable_timeout() can return the positive
	  value while condition == F

Change the code to always check __retval/condition before return.

Note: with or without this patch the timeout logic looks strange,
probably we should recalc timeout if try_to_freeze() returns T.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>

There's no in-kernel user of set_freezable_with_signal() left.  Mixing
TIF_SIGPENDING with kernel threads can lead to nasty corner cases as
kernel threads never travel signal delivery path on their own.

e.g. the current implementation is buggy in the cancelation path of
__thaw_task().  It calls recalc_sigpending_and_wake() in an attempt to
clear TIF_SIGPENDING but the function never clears it regardless of
sigpending state.  This means that signallable freezable kthreads may
continue executing with !freezing() && stuck TIF_SIGPENDING, which can
be troublesome.

This patch removes set_freezable_with_signal() along with
PF_FREEZER_NOSIG and recalc_sigpending*() calls in freezer.  User
tasks get TIF_SIGPENDING, kernel tasks get woken up and the spurious
sigpending is dealt with in the usual signal delivery path.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>

Commit 981ed70d (dmatest: make dmatest threads freezable) made
dmatest kthread use set_freezable_with_signal(); however, the
interface is scheduled to be removed in the next merge window.

The problem is that unlike userland tasks there's no default place
which handles signal pending state and it isn't clear who owns and/or
is responsible for clearing TIF_SIGPENDING.  For example, in the
current code, try_to_freeze() clears TIF_SIGPENDING but it isn't sure
whether it actually owns the TIF_SIGPENDING nor is it race-free -
ie. the task may continue to run with TIF_SIGPENDING set after the
freezable section.

Unfortunately, we don't have wait_for_completion_freezable_timeout().
This patch open codes it and uses wait_event_freezable_timeout()
instead and removes timeout reloading - wait_event_freezable_timeout()
won't return across freezing events (currently racy but fix scheduled)
and timer doesn't decrement while the task is in freezer.  Although
this does lose timer-reset-over-freezing, given that timeout is
supposed to be long enough and failure to finish inside is considered
irrecoverable, I don't think this is worth the complexity.

While at it, move completion to outer scope and explain that we're
ignoring dangling pointer problem after timeout.  This should give
slightly better chance at avoiding oops after timeout.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>

Count of selector voltage is required for regulator_set_voltage
to work via set_voltage_sel. VDD1/2 currently have it as zero,
so regulator_set_voltage won't work for VDD1/2.
Update count (n_voltages) for VDD1/2.

Output Voltage = (step value * 12.5 mV + 562.5 mV) * gain

With above expr, number of voltages that can be selected is
step value count * gain count

constant for gain count will be called VDD1_2_NUM_VOLT_COARSE

existing constant for step value count is VDD1_2_NUM_VOLTS,
use VDD1_2_NUM_VOLT_FINE instead to make clear that step value
is not the only component in deciding selectable voltage count
Signed-off-by: Afzal Mohammed <afzal@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

The function i2cdev_notifier_call is used only in i2c-dev file
making it static.
Also removes the following sparse warning

drivers/i2c/i2c-dev.c:582:5: warning: symbol 'i2cdev_notifier_call'
was not declared. Should it be static?
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Last piece of code using ANY_I2C_BUS was deleted almost 2 years ago,
so ANY_I2C_BUS can go away as well.
Signed-off-by: Jean Delvare <khali@linux-fr.org>

10-bit addresses overlap with traditional 7-bit addresses, leading in
device name collisions. Add an arbitrary offset to 10-bit addresses to
prevent this collision. The offset was chosen so that the address is
still easily recognizable.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>

The wrong bits were put on the wire, fix that.

This fixes kernel bug #42562.
Signed-off-by: Sheng-Hui J. Chu <jeffchu@broadcom.com>
Cc: stable@kernel.org
Signed-off-by: Jean Delvare <khali@linux-fr.org>

There is a potential integer overflow in drm_mode_dirtyfb_ioctl()
if userspace passes in a large num_clips.  The call to kmalloc would
allocate a small buffer, and the call to fb->funcs->dirty may result
in a memory corruption.
Reported-by: Haogang Chen <haogangchen@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

This reverts commit dc937280.

As requested by Ben Herrenschmidt:
  "This breaks some powerpc platforms at least.  The practice of having
   a node provide an explicit "interrupt-parent" property pointing to
   itself is an old trick that we've used in the past to allow a
   device-node to have interrupts routed to different controllers.

   In that case, the node also contains an interrupt-map, so the node is
   its own parent, the interrupt resolution hits the map, which then can
   route each individual interrupt to a different parent."

Grant says:
  "Ah, nuts, yes that is broken then.  Yes, please revert the commit and
   Rob & I will come up with a better solution.

   Rob, I think it can be done by explicitly checking for np ==
   desc->interrupt_parent in of_irq_init() instead of relying on
   of_irq_find_parent() returning NULL."
Requested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Cc: Tanmay Inamdar <tinamdar@apm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>