cpuset: fix a locking issue in cpuset_migrate_mm()

I can trigger a lockdep warning:

  # mount -t cgroup -o cpuset xxx /cgroup
  # mkdir /cgroup/cpuset
  # mkdir /cgroup/tmp
  # echo 0 > /cgroup/tmp/cpuset.cpus
  # echo 0 > /cgroup/tmp/cpuset.mems
  # echo 1 > /cgroup/tmp/cpuset.memory_migrate
  # echo $$ > /cgroup/tmp/tasks
  # echo 1 > /cgruop/tmp/cpuset.mems

  ===============================
  [ INFO: suspicious RCU usage. ]
  3.14.0-rc1-0.1-default+ #32 Not tainted
  -------------------------------
  include/linux/cgroup.h:682 suspicious rcu_dereference_check() usage!
  ...
    [<ffffffff81582174>] dump_stack+0x72/0x86
    [<ffffffff810b8f01>] lockdep_rcu_suspicious+0x101/0x140
    [<ffffffff81105ba1>] cpuset_migrate_mm+0xb1/0xe0
  ...

We used to hold cgroup_mutex when calling cpuset_migrate_mm(), but now
we hold cpuset_mutex, which causes task_css() to complain.

This is not a false-positive but a real issue.

Holding cpuset_mutex won't prevent a task from migrating to another
cpuset, and it won't prevent the original task->cgroup from destroying
during this change.

Fixes: 5d21cc2db040 (cpuset: replace cgroup_mutex locking with cpuset internal locking)
Cc: <stable@vger.kernel.org> # 3.9+
Signed-off-by: Li Zefan <lizefan@huawei.com>
Sigend-off-by: Tejun Heo <tj@kernel.org>
cpuset: fix a race condition in __cpuset_node_allowed_softwall()

It's not safe to access task's cpuset after releasing task_lock().
Holding callback_mutex won't help.

Cc: <stable@vger.kernel.org>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
firewire: net: fix use after free

Commit 8408dc1c14c1 "firewire: net: use dev_printk API" introduced a
use-after-free in a failure path.  fwnet_transmit_packet_failed(ptask)
may free ptask, then the dev_err() call dereferenced it.  The fix is
straightforward; simply reorder the two calls.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
ACPI / resources: ignore invalid ACPI device resources

ACPI table may export resource entry with 0 length.
But the current code interprets this kind of resource in a wrong way.
It will create a resource structure with
res->end = acpi_resource->start + acpi_resource->len - 1;

This patch fixes a problem on my machine that a platform device fails
to be created because one of its ACPI IO resource entry (start = 0,
end = 0, length = 0) is translated into a generic resource with
start = 0, end = 0xffffffff.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / sleep: pm_power_off needs more sanity checks to be installed

Sleep control and status registers need santity checks as well before
ACPI installs acpi_power_off to pm_power_off hook. The checking code in
acpi_enter_sleep_state() is too late, we should not allow a not-working
pm_power_off function to be hooked up.

Signed-off-by: Aubrey Li <aubrey.li@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
libata: disable queued TRIM for Crucial M500 mSATA SSDs

Queued TRIM commands cause problems and silent file system corruption
on Crucial M500 SSDs. This patch disables them for the mSATA model of
the drive.

Signed-off-by: Marios Andreopoulos <opensource@andmarios.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # 3.12+
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=71371
clk: shmobile: rcar-gen2: Use kick bit to allow Z clock frequency change

The Z clock frequency change is effective only after setting the kick
bit located in the FRQCRB register.
Without that, the CA15 CPUs clock rate will never change.

Fix that by checking if the kick bit is cleared and enable it to make
the clock rate change effective. The bit is cleared automatically upon
completion.

Signed-off-by: Benoit Cousson <bcousson+renesas@baylibre.com>
Acked-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
cpufreq: use cpufreq_cpu_get() to avoid cpufreq_get() race conditions

If a module calls cpufreq_get while cpufreq is initializing, it's
possible for it to be called after cpufreq_driver is set but before
cpufreq_cpu_data is written during subsys_interface_register.  This
happens because cpufreq_get doesn't take the cpufreq_driver_lock
around its use of cpufreq_cpu_data.

Fix this by using cpufreq_cpu_get(cpu) to look up the policy rather
than reading it out of cpufreq_cpu_data directly.  cpufreq_cpu_get()
takes the appropriate locks to prevent this race from happening.

Since it's possible for policy to be NULL if the caller passes in an
invalid CPU number or calls the function before cpufreq is initialized,
delete the BUG_ON(!policy) and simply return 0.  Don't try to return
-ENOENT because that's negative and the function returns an unsigned
integer.

References: https://bbs.archlinux.org/viewtopic.php?id=177934
Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Initialize policy before making it available for others to use

Policy must be fully initialized before it is being made available
for use by others. Otherwise cpufreq_cpu_get() would be able to grab
a half initialized policy structure that might not have affected_cpus
(for example) populated. Then, anybody accessing those fields will get
a wrong value and that will lead to unpredictable results.

In order to fix this, do all the necessary initialization before we
make the policy structure available via cpufreq_cpu_get(). That will
guarantee that any code accessing fields of the policy will get
correct data from them.

Reported-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: Initialize governor for a new policy under policy->rwsem

policy->rwsem is used to lock access to all parts of code modifying
struct cpufreq_policy, but it's not used on a new policy created by
__cpufreq_add_dev().

Because of that, if cpufreq_update_policy() is called in a tight loop
on one CPU in parallel with offline/online of another CPU, then the
following crash can be triggered:

Unable to handle kernel NULL pointer dereference at virtual address 00000020
pgd = c0003000
[00000020] *pgd=80000000004003, *pmd=00000000
Internal error: Oops: 206 [#1] PREEMPT SMP ARM

PC is at __cpufreq_governor+0x10/0x1ac
LR is at cpufreq_update_policy+0x114/0x150

---[ end trace f23a8defea6cd706 ]---
Kernel panic - not syncing: Fatal exception
CPU0: stopping
CPU: 0 PID: 7136 Comm: mpdecision Tainted: G      D W    3.10.0-gd727407-00074-g979ede8 #396

[<c0afe180>] (notifier_call_chain+0x40/0x68) from [<c02a23ac>] (__blocking_notifier_call_chain+0x40/0x58)
[<c02a23ac>] (__blocking_notifier_call_chain+0x40/0x58) from [<c02a23d8>] (blocking_notifier_call_chain+0x14/0x1c)
[<c02a23d8>] (blocking_notifier_call_chain+0x14/0x1c) from [<c0803c68>] (cpufreq_set_policy+0xd4/0x2b8)
[<c0803c68>] (cpufreq_set_policy+0xd4/0x2b8) from [<c0803e7c>] (cpufreq_init_policy+0x30/0x98)
[<c0803e7c>] (cpufreq_init_policy+0x30/0x98) from [<c0805a18>] (__cpufreq_add_dev.isra.17+0x4dc/0x7a4)
[<c0805a18>] (__cpufreq_add_dev.isra.17+0x4dc/0x7a4) from [<c0805d38>] (cpufreq_cpu_callback+0x58/0x84)
[<c0805d38>] (cpufreq_cpu_callback+0x58/0x84) from [<c0afe180>] (notifier_call_chain+0x40/0x68)
[<c0afe180>] (notifier_call_chain+0x40/0x68) from [<c02812dc>] (__cpu_notify+0x28/0x44)
[<c02812dc>] (__cpu_notify+0x28/0x44) from [<c0aeed90>] (_cpu_up+0xf4/0x1dc)
[<c0aeed90>] (_cpu_up+0xf4/0x1dc) from [<c0aeeed4>] (cpu_up+0x5c/0x78)
[<c0aeeed4>] (cpu_up+0x5c/0x78) from [<c0aec808>] (store_online+0x44/0x74)
[<c0aec808>] (store_online+0x44/0x74) from [<c03a40f4>] (sysfs_write_file+0x108/0x14c)
[<c03a40f4>] (sysfs_write_file+0x108/0x14c) from [<c03517d4>] (vfs_write+0xd0/0x180)
[<c03517d4>] (vfs_write+0xd0/0x180) from [<c0351ca8>] (SyS_write+0x38/0x68)
[<c0351ca8>] (SyS_write+0x38/0x68) from [<c0205de0>] (ret_fast_syscall+0x0/0x30)

Fix that by taking locks at appropriate places in __cpufreq_add_dev()
as well.

Reported-by: Saravana Kannan <skannan@codeaurora.org>
Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / EC: Clear stale EC events on Samsung systems

A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc)
continue to log events during sleep (lid open/close, AC plug/unplug,
battery level change), which accumulate in the EC until a buffer fills.
After the buffer is full (tests suggest it holds 8 events), GPEs stop
being triggered for new events. This state persists on wake or even on
power cycle, and prevents new events from being registered until the EC
is manually polled.

This is the root cause of a number of bugs, including AC not being
detected properly, lid close not triggering suspend, and low ambient
light not triggering the keyboard backlight. The bug also seemed to be
responsible for performance issues on at least one user's machine.

Juan Manuel Cabo found the cause of bug and the workaround of polling
the EC manually on wake.

The loop which clears the stale events is based on an earlier patch by
Lan Tianyu (see referenced attachment).

This patch:
 - Adds a function acpi_ec_clear() which polls the EC for stale _Q
   events at most ACPI_EC_CLEAR_MAX (currently 100) times. A warning is
   logged if this limit is reached.
 - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI
   system vendor is Samsung. This check could be replaced by several
   more specific DMI vendor/product pairs, but it's likely that the bug
   affects more Samsung products than just the five series mentioned
   above. Further, it should not be harmful to run acpi_ec_clear() on
   systems without the bug; it will return immediately after finding no
   data waiting.
 - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add()
 - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions()

References: https://bugzilla.kernel.org/show_bug.cgi?id=44161
References: https://bugzilla.kernel.org/show_bug.cgi?id=45461
References: https://bugzilla.kernel.org/show_bug.cgi?id=57271
References: https://bugzilla.kernel.org/attachment.cgi?id=126801
Suggested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com>
Signed-off-by: Kieran Clancy <clancy.kieran@gmail.com>
Reviewed-by: Lan Tianyu <tianyu.lan@intel.com>
Reviewed-by: Dennis Jansen <dennis.jansen@web.de>
Tested-by: Kieran Clancy <clancy.kieran@gmail.com>
Tested-by: Juan Manuel Cabo <juanmanuel.cabo@gmail.com>
Tested-by: Dennis Jansen <dennis.jansen@web.de>
Tested-by: Maurizio D'Addona <mauritiusdadd@gmail.com>
Tested-by: San Zamoyski <san@plusnet.pl>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
firewire: ohci: fix probe failure with Agere/LSI controllers

Since commit bd972688eb24
"firewire: ohci: Fix 'failed to read phy reg' on FW643 rev8",
there is a high chance that firewire-ohci fails to initialize LSI née
Agere controllers.
https://bugzilla.kernel.org/show_bug.cgi?id=65151

Peter Hurley points out the reason:  IEEE 1394a:2000 clause 5A.1 (or
IEEE 1394:2008 clause 17.2.1) say:  "The PHY shall insure that no more
than 10 ms elapse from the reassertion of LPS until the interface is
reset.  The link shall not assert LReq until the reset is complete."
In other words, the link needs to give the PHY at least 10 ms to get
the interface operational.

With just the msleep(1) in bd972688eb24, the first read_phy_reg()
during ohci_enable() may happen before the phy-link interface reset was
finished, and fail.  Due to the high variability of msleep(n) with small
n, this failure was not fully reproducible, and not apparent at all with
low CONFIG_HZ setting.

On the other hand, Peter can no longer reproduce the issue with FW643
rev8.  The read phy reg failures that happened back then may have had an
unrelated cause.  So, just revert bd972688eb24, except for the valid
comment on TSB82AA2 cards.

Reported-by: Mikhail Gavrilov
Reported-by: Jay Fenlason <fenlason@redhat.com>
Reported-by: Clemens Ladisch <clemens@ladisch.de>
Reported-by: Peter Hurley <peter@hurleysoftware.com>
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
firewire: don't use PREPARE_DELAYED_WORK

PREPARE_[DELAYED_]WORK() are being phased out.  They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.

firewire core-device and sbp2 have been been multiplexing work items
with multiple work functions.  Introduce fw_device_workfn() and
sbp2_lu_workfn() which invoke fw_device->workfn and
sbp2_logical_unit->workfn respectively and always use the two
functions as the work functions and update the users to set the
->workfn fields instead of overriding work functions using
PREPARE_DELAYED_WORK().

This fixes a variety of possible regressions since a2c1c57be8d9
"workqueue: consider work function when searching for busy work items"
due to which fw_workqueue lost its required non-reentrancy property.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: linux1394-devel@lists.sourceforge.net
Cc: stable@vger.kernel.org # v3.9+
Cc: stable@vger.kernel.org # v3.8.2+
Cc: stable@vger.kernel.org # v3.4.60+
Cc: stable@vger.kernel.org # v3.2.40+
libata: add ATA_HORKAGE_BROKEN_FPDMA_AA quirk for Seagate Momentus SpinPoint M8 (2BA30001)

Via commit 87809942d3fa "libata: add ATA_HORKAGE_BROKEN_FPDMA_AA quirk
for Seagate Momentus SpinPoint M8" we added a quirk for disks named
"ST1000LM024 HN-M101MBB" with firmware revision "2AR10001".

As reported on https://bugzilla.redhat.com/show_bug.cgi?id=1073901,
we need to also add firmware revision 2BA30001 as it is broken as well.

Reported-by: Nicholas <arealityfarbetween@googlemail.com>
Signed-off-by: Michele Baldessari <michele@acksyn.org>
Tested-by: Guilherme Amadio <guilherme.amadio@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Merge branches 'acpi-resources', 'acpi-ec' and 'acpi-sleep'

* acpi-resources:
  ACPI / resources: ignore invalid ACPI device resources

* acpi-ec:
  ACPI / EC: Clear stale EC events on Samsung systems

* acpi-sleep:
  ACPI / sleep: pm_power_off needs more sanity checks to be installed
Merge branch 'pm-cpufreq'

* pm-cpufreq:
  cpufreq: Initialize governor for a new policy under policy->rwsem
  cpufreq: Initialize policy before making it available for others to use
  cpufreq: use cpufreq_cpu_get() to avoid cpufreq_get() race conditions
Merge tag 'pm+acpi-3.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael Wysocki:

 - ACPI tables in some BIOSes list device resources with size equal to
   0, which doesn't make sense, so we should ignore them, but instead we
   try to use them and mangle things completely.  Fix from Zhang Rui.

 - Several models of Samsung laptops accumulate EC events when they are
   in sleep states which leads to EC buffer overflows that prevent new
   events from being signaled after system resume or reboot.  This has
   been affecting many users for quite a while and may be addressed by
   clearing the EC buffer during system resume and system startup on
   those machines.  From Kieran Clancy.

 - If the ACPI sleep control and status registers are not present (which
   happens if the Hardware Reduced ACPI mode bit is set in the ACPI
   tables, but also may result from BIOS bugs), we should not try to use
   ACPI to power off the system and ACPI S5 should not be listed as
   supported.  Fix from Aubrey Li.

 - There's a race condition in cpufreq_get() that leads to a kernel
   crash if that function is called at a wrong time.  Fix from Aaron
   Plattner.

 - cpufreq policy objects have to be initialized entirely before they
   are first accessed by their users which isn't the case currently and
   that potentially leads to various kinds of breakage that is difficult
   to debug.  Fix from Viresh Kumar.

 - Locking is missing in __cpufreq_add_dev() which leads to a race
   condition that may trigger a kernel crash.  Fix from Viresh Kumar.

* tag 'pm+acpi-3.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / EC: Clear stale EC events on Samsung systems
  cpufreq: Initialize governor for a new policy under policy->rwsem
  cpufreq: Initialize policy before making it available for others to use
  cpufreq: use cpufreq_cpu_get() to avoid cpufreq_get() race conditions
  ACPI / sleep: pm_power_off needs more sanity checks to be installed
  ACPI / resources: ignore invalid ACPI device resources
Merge tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux

Pull clk driver fix from Mike Turquette:
 "Single fix for a clock driver merged in 3.14-rc1.  Without this fix
  the CPU frequency cannot be scaled"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: shmobile: rcar-gen2: Use kick bit to allow Z clock frequency change
Merge tag 'firewire-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

Pull firewire fixes from Stefan Richter:
 "Fix a use-after-free regression since v3.4 and an initialization
  regression since v3.10"

* tag 'firewire-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: ohci: fix probe failure with Agere/LSI controllers
  firewire: net: fix use after free
Merge branch 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue fix from Tejun Heo:
 "This pull request contains a workqueue usage fix for firewire.

  For quite a long time now, workqueue only treats two work items
  identical iff both their addresses and callbacks match.  This is to
  avoid introducing false dependency through the work item being
  recycled while being executed.  This changes non-reentrancy guarantee
  for the users of PREPARE[_DELAYED]_WORK() - if the function changes,
  reentrancy isn't guaranteed against the previous instance.  Firewire
  depended on such nonreentrancy guarantee.

  This is fixed by doing the work item multiplexing from firewire proper
  while keeping the work function unchanged"

* 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  firewire: don't use PREPARE_DELAYED_WORK