Currently seqlocks and seqcounts don't support lockdep.

After running across a seqcount related deadlock in the timekeeping
code, I used a less-refined and more focused variant of this patch
to narrow down the cause of the issue.

This is a first-pass attempt to properly enable lockdep functionality
on seqlocks and seqcounts.

Since seqcounts are used in the vdso gettimeofday code, I've provided
non-lockdep accessors for those needs.

I've also handled one case where there were nested seqlock writers
and there may be more edge cases.

Comments and feedback would be appreciated!
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-3-git-send-email-john.stultz@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

In order to enable lockdep on seqcount/seqlock structures, we
must explicitly initialize any locks.

The u64_stats_sync structure, uses a seqcount, and thus we need
to introduce a u64_stats_init() function and use it to initialize
the structure.

This unfortunately adds a lot of fairly trivial initialization code
to a number of drivers. But the benefit of ensuring correctness makes
this worth while.

Because these changes are required for lockdep to be enabled, and the
changes are quite trivial, I've not yet split this patch out into 30-some
separate patches, as I figured it would be better to get the various
maintainers thoughts on how to best merge this change along with
the seqcount lockdep enablement.

Feedback would be appreciated!
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Acked-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: James Morris <jmorris@namei.org>
Cc: Jesse Gross <jesse@nicira.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mirko Lindner <mlindner@marvell.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Roger Luethi <rl@hellgate.ch>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Simon Horman <horms@verge.net.au>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Wensong Zhang <wensong@linux-vs.org>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1381186321-4906-2-git-send-email-john.stultz@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-52bjmtty46we26hbfd9sc9iy@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-amd6pg1mif6tikbyktfvby3y@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Notably: changed lib/rwsem* targets from lib- to obj-, no idea about
the ramifications of that.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-g0kynfh5feriwc6p3h6kpbw6@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-p9ijt8div0hwldexwfm4nlhj@git.kernel.org
[ Fixed build failure in kernel/rcu/tree_plugin.h. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-vmw5sf6vzmua1z6nx1cg69h2@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-b81ol0z3mon45m51o131yc9j@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-wl7s3tta5isufzfguc23et06@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-1ditvncg30dgbpvrz2bxfmke@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Conflicts:
	kernel/Makefile

There are conflicts in kernel/Makefile due to file moving in the
scheduler tree - resolve them.
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Completions already have their own header file: linux/completion.h
Move the implementation out of kernel/sched/core.c and into its own
file: kernel/sched/completion.c.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-x2y49rmxu5dljt66ai2lcfuw@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

For some reason only the wait part of the wait api lives in
kernel/sched/wait.c and the wake part still lives in kernel/sched/core.c;
ammend this.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-ftycee88naznulqk7ei5mbci@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-5q5yqvdaen0rmapwloeaotx3@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

There are conflicts in lockdep.c due to RCU changes, and also the RCU
tree changes kernel/Makefile - so pre-merge it to ease the moving of
locking related .c files to kernel/locking/.
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Signed-off-by: NIngo Molnar <mingo@kernel.org>

Pull MIPS fixes from Ralf Baechle:
 "Three fixes across arch/mips with the most complex one being the GIC
  interrupt fix - at nine lines still not monster.  I'm confident this
  are the final MIPS patches even if there should go for an rc8"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: ralink: fix return value check in rt_timer_probe()
  MIPS: malta: Fix GIC interrupt offsets
  MIPS: Perf: Fix 74K cache map

Negative message lengths make no sense -- so don't do negative queue
lenghts or identifier counts. Prevent them from getting negative.

Also change the underlying data types to be unsigned to avoid hairy
surprises with sign extensions in cases where those variables get
evaluated in unsigned expressions with bigger data types, e.g size_t.

In case a user still wants to have "unlimited" sizes she could just use
INT_MAX instead.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull ARM kallsyms fix from Rusty Russell:
 "Last minute perf unbreakage for ARM modules; spent a day in
  linux-next"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  scripts/kallsyms: filter symbols not in kernel address space

A vmalloc fault needs to sync up PGD/PTE entry from init_mm to current
task's "active_mm".  ARC vmalloc fault handler however was using mm.

A vmalloc fault for non user task context (actually pre-userland, from
init thread's open for /dev/console) caused the handler to deref NULL mm
(for mm->pgd)

The reasons it worked so far is amazing:

1. By default (!SMP), vmalloc fault handler uses a cached value of PGD.
   In SMP that MMU register is repurposed hence need for mm pointer deref.

2. In pre-3.12 SMP kernel, the problem triggering vmalloc didn't exist in
   pre-userland code path - it was introduced with commit 20bafb3d
   "n_tty: Move buffers into n_tty_data"
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: stable@vger.kernel.org    #3.10 and 3.11
Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch uses CONFIG_PAGE_OFFSET to filter symbols which
are not in kernel address space because these symbols are
generally for generating code purpose and can't be run at
kernel mode, so we needn't keep them in /proc/kallsyms.

For example, on ARM there are some symbols which may be
linked in relocatable code section, then perf can't parse
symbols any more from /proc/kallsyms, this patch fixes the
problem (introduced b9b32bf7)

Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: NMing Lei <tom.leiming@gmail.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: stable@vger.kernel.org

Pull perf fixes from Ingo Molnar:
 "Two fixes:

   - Fix 'NMI handler took too long to run' false positives

     [ Genuine NMI overhead speedups will come for v3.13, this commit
       only fixes a measurement bug ]

   - Fix perf ring-buffer missed barrier causing (rare) ring-buffer data
     corruption on ppc64"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Fix NMI measurements
  perf: Fix perf ring buffer memory ordering

Pull USB fixes from Greg KH:
 "Here is a set of patches that revert all of the changes done to the
  pl2303 USB serial driver in the 3.12-rc timeframe, as it turns out
  they break some devices that work just fine on 3.11.  As it's not a
  good idea to break working systems, drop them all and they will be
  reworked for future kernel versions such that there is no breakage.

  I've also included a MAINTAINERS update for the USB serial subsystem
  and a new device id for the ftdi_sio driver as well"

* tag 'usb-3.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: serial: ftdi_sio: add id for Z3X Box device
  USB: Maintainers change for usb serial drivers
  Revert "USB: pl2303: restrict the divisor based baud rate encoding method to the "HX" chip type"
  Revert "usb: pl2303: fix+improve the divsor based baud rate encoding method"
  Revert "usb: pl2303: do not round to the next nearest standard baud rate for the divisor based baud rate encoding method"
  Revert "usb: pl2303: remove 500000 baud from the list of standard baud rates"
  Revert "usb: pl2303: move the two baud rate encoding methods to separate functions"
  Revert "usb: pl2303: increase the allowed baud rate range for the divisor based encoding method"
  Revert "usb: pl2303: also use the divisor based baud rate encoding method for baud rates < 115200 with HX chips"
  Revert "usb: pl2303: add two comments concerning the supported baud rates with HX chips"
  Revert "pl2303: simplify the else-if contruct for type_1 chips in pl2303_startup()"
  Revert "pl2303: improve the chip type information output on startup"
  Revert "pl2303: improve the chip type detection/distinction"
  Revert "USB: pl2303: distinguish between original and cloned HX chips"

Pull more sound fixes from Takashi Iwai:
 "The fixes for random bugs that have been reported lately in the game:
  a few fixes in ASoC dpam and wm_hubs bugs spotted by Coverity, a
  one-liner HD-audio fixup, and a fix for Oops with DPCM.

  They are not so critically urgent bugs, but all small and safe"

* tag 'sound-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: fix oops in snd_pcm_info() caused by ASoC DPCM
  ASoC: wm_hubs: Add missing break in hp_supply_event()
  ALSA: hda - Add a fixup for ASUS N76VZ
  ASoC: dapm: Return -ENOMEM in snd_soc_dapm_new_dai_widgets()
  ASoC: dapm: Fix source list debugfs outputs

Pull clock subsystem fixes from Mike Turquette.

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mturquette/linux:
  clk: fixup argument order when setting VCO parameters
  clk: socfpga: Fix incorrect sdmmc clock name
  clk: armada-370: fix tclk frequencies
  clk: nomadik: set all timers to use 2.4 MHz TIMCLK

When a memcg is deleted mem_cgroup_reparent_charges() moves charged
memory to the parent memcg.  As of v3.11-9444-g3ea67d06 "memcg: add per
cgroup writeback pages accounting" there's bad pointer read.  The goal
was to check for counter underflow.  The counter is a per cpu counter
and there are two problems with the code:

 (1) per cpu access function isn't used, instead a naked pointer is used
     which easily causes oops.
 (2) the check doesn't sum all cpus

Test:
  $ cd /sys/fs/cgroup/memory
  $ mkdir x
  $ echo 3 > /proc/sys/vm/drop_caches
  $ (echo $BASHPID >> x/tasks && exec cat) &
  [1] 7154
  $ grep ^mapped x/memory.stat
  mapped_file 53248
  $ echo 7154 > tasks
  $ rmdir x
  <OOPS>

The fix is to remove the check.  It's currently dangerous and isn't
worth fixing it to use something expensive, such as
percpu_counter_sum(), for each reparented page.  __this_cpu_read() isn't
enough to fix this because there's no guarantees of the current cpus
count.  The only guarantees is that the sum of all per-cpu counter is >=
nr_pages.

Fixes: 3ea67d06 ("memcg: add per cgroup writeback pages accounting")
Reported-and-tested-by: NFlavio Leitner <fbl@redhat.com>
Signed-off-by: NGreg Thelen <gthelen@google.com>
Reviewed-by: NSha Zhengju <handai.szj@taobao.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Custom VID/PID for Z3X Box device, popular tool for cellphone flashing.
Signed-off-by: NAlexey E. Kramarenko <alexeyk13@yandex.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Johan has been conned^Wgracious in accepting the maintainership of the
USB serial drivers, especially as he's been doing all of the real work
for the past few years.

At the same time, remove a bunch of old entries for USB serial drivers
that don't make sense anymore, given that the developers are no longer
around, and individual driver maintainerships for tiny things like this
is pretty pointless.
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit b8bdad60.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 57ce61aa.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "usb: pl2303: do not round to the next nearest standard baud rate for the divisor based baud rate encoding method"

This reverts commit 75417d9f.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit b9208c72.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit e917ba01.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit b5c16c6a.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "usb: pl2303: also use the divisor based baud rate encoding method for baud rates < 115200 with HX chips"

This reverts commit 61fa8d69.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit c23bda36.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 73b583af.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit a77a8c23.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 034d1527.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.
Reported-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>