ACPI / PM: Fix resource_lock dead lock in acpi_power_on_device

commit 40bf66ec9791f1452b90b82aadc3b6e6aee201f5 upstream.

Commit 0090def("ACPI: Add interface to register/unregister device
to/from power resources") used resource_lock to protect the devices list
that relies on power resource. It caused a mutex dead lock, as below

    acpi_power_on ---> lock resource_lock
      __acpi_power_on
        acpi_power_on_device
          acpi_power_get_inferred_state
            acpi_power_get_list_state ---> lock resource_lock

This patch adds a new mutex "devices_lock" to protect the devices list
and calls acpi_power_on_device in acpi_power_on, instead of
__acpi_power_on, after the resource_lock is released.

[rjw: Changed data type of a boolean variable to bool.]

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ACPI / PM: Use KERN_DEBUG when no power resources are found

commit f25b70613c048ceb1df052576fda03321ebf41cf upstream.

commit a606dac368eed5696fb38e16b1394f1d049c09e9 adds support to link
devices which have _PRx, if a device does not have _PRx, a warning
message will be printed.

This commit is for ZPODD on Intel ZPODD capable platforms, on other
platforms, it has no problem if there is no power resource for this
device, so a warning here is not appropriate, change it to debug.

Reported-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mmc: mxs-mmc: fix deadlock in SDIO IRQ case

commit 1af36b2a993dddfa3d6860ec4879c9e8abc9b976 upstream.

Release the lock before mmc_signal_sdio_irq is called by mxs_mmc_irq_handler.

Backtrace:
[   79.660000] =============================================
[   79.660000] [ INFO: possible recursive locking detected ]
[   79.660000] 3.4.0-00009-g3e96082-dirty #11 Not tainted
[   79.660000] ---------------------------------------------
[   79.660000] swapper/0 is trying to acquire lock:
[   79.660000]  (&(&host->lock)->rlock#2){-.....}, at: [<c026ea3c>] mxs_mmc_enable_sdio_irq+0x18/0xd4
[   79.660000]
[   79.660000] but task is already holding lock:
[   79.660000]  (&(&host->lock)->rlock#2){-.....}, at: [<c026f744>] mxs_mmc_irq_handler+0x1c/0xe8
[   79.660000]
[   79.660000] other info that might help us debug this:
[   79.660000]  Possible unsafe locking scenario:
[   79.660000]
[   79.660000]        CPU0
[   79.660000]        ----
[   79.660000]   lock(&(&host->lock)->rlock#2);
[   79.660000]   lock(&(&host->lock)->rlock#2);
[   79.660000]
[   79.660000]  *** DEADLOCK ***
[   79.660000]
[   79.660000]  May be due to missing lock nesting notation
[   79.660000]
[   79.660000] 1 lock held by swapper/0:
[   79.660000]  #0:  (&(&host->lock)->rlock#2){-.....}, at: [<c026f744>] mxs_mmc_irq_handler+0x1c/0xe8
[   79.660000]
[   79.660000] stack backtrace:
[   79.660000] [<c0014bd0>] (unwind_backtrace+0x0/0xf4) from [<c005f9c0>] (__lock_acquire+0x1948/0x1d48)
[   79.660000] [<c005f9c0>] (__lock_acquire+0x1948/0x1d48) from [<c005fea0>] (lock_acquire+0xe0/0xf8)
[   79.660000] [<c005fea0>] (lock_acquire+0xe0/0xf8) from [<c03a8460>] (_raw_spin_lock_irqsave+0x44/0x58)
[   79.660000] [<c03a8460>] (_raw_spin_lock_irqsave+0x44/0x58) from [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4)
[   79.660000] [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8)
[   79.660000] [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8) from [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254)
[   79.660000] [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254) from [<c006bff8>] (handle_irq_event+0x3c/0x5c)
[   79.660000] [<c006bff8>] (handle_irq_event+0x3c/0x5c) from [<c006e6d0>] (handle_level_irq+0x90/0x110)
[   79.660000] [<c006e6d0>] (handle_level_irq+0x90/0x110) from [<c006b930>] (generic_handle_irq+0x38/0x50)
[   79.660000] [<c006b930>] (generic_handle_irq+0x38/0x50) from [<c00102fc>] (handle_IRQ+0x30/0x84)
[   79.660000] [<c00102fc>] (handle_IRQ+0x30/0x84) from [<c000f058>] (__irq_svc+0x38/0x60)
[   79.660000] [<c000f058>] (__irq_svc+0x38/0x60) from [<c0010520>] (default_idle+0x2c/0x40)
[   79.660000] [<c0010520>] (default_idle+0x2c/0x40) from [<c0010a90>] (cpu_idle+0x64/0xcc)
[   79.660000] [<c0010a90>] (cpu_idle+0x64/0xcc) from [<c04ff858>] (start_kernel+0x244/0x2c8)
[   79.660000] BUG: spinlock lockup on CPU#0, swapper/0
[   79.660000]  lock: c398cb2c, .magic: dead4ead, .owner: swapper/0, .owner_cpu: 0
[   79.660000] [<c0014bd0>] (unwind_backtrace+0x0/0xf4) from [<c01ddb1c>] (do_raw_spin_lock+0xf0/0x144)
[   79.660000] [<c01ddb1c>] (do_raw_spin_lock+0xf0/0x144) from [<c03a8468>] (_raw_spin_lock_irqsave+0x4c/0x58)
[   79.660000] [<c03a8468>] (_raw_spin_lock_irqsave+0x4c/0x58) from [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4)
[   79.660000] [<c026ea3c>] (mxs_mmc_enable_sdio_irq+0x18/0xd4) from [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8)
[   79.660000] [<c026f7fc>] (mxs_mmc_irq_handler+0xd4/0xe8) from [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254)
[   79.660000] [<c006bdd8>] (handle_irq_event_percpu+0x70/0x254) from [<c006bff8>] (handle_irq_event+0x3c/0x5c)
[   79.660000] [<c006bff8>] (handle_irq_event+0x3c/0x5c) from [<c006e6d0>] (handle_level_irq+0x90/0x110)
[   79.660000] [<c006e6d0>] (handle_level_irq+0x90/0x110) from [<c006b930>] (generic_handle_irq+0x38/0x50)
[   79.660000] [<c006b930>] (generic_handle_irq+0x38/0x50) from [<c00102fc>] (handle_IRQ+0x30/0x84)
[   79.660000] [<c00102fc>] (handle_IRQ+0x30/0x84) from [<c000f058>] (__irq_svc+0x38/0x60)
[   79.660000] [<c000f058>] (__irq_svc+0x38/0x60) from [<c0010520>] (default_idle+0x2c/0x40)
[   79.660000] [<c0010520>] (default_idle+0x2c/0x40) from [<c0010a90>] (cpu_idle+0x64/0xcc)
[   79.660000] [<c0010a90>] (cpu_idle+0x64/0xcc) from [<c04ff858>] (start_kernel+0x244/0x2c8)

Signed-off-by: Lauri Hintsala <lauri.hintsala@bluegiga.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mmc: sdhci-esdhc: break out early if clock is 0

commit 74f330bceaa7b88d06062e1cac3d519a3dfc041e upstream.

Since commit 30832ab56 ("mmc: sdhci: Always pass clock request value
zero to set_clock host op") was merged, esdhc_set_clock starts hitting
"if (clock == 0)" where ESDHC_SYSTEM_CONTROL has been operated.  This
causes SDHCI card-detection function being broken.  Fix the regression
by moving "if (clock == 0)" above ESDHC_SYSTEM_CONTROL operation.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
oprofile, s390: Fix uninitialized memory access when writing to oprofilefs

commit 81ff3478d9ba7f0b48b0abef740e542fd83adf79 upstream.

If oprofilefs_ulong_from_user() is called with count equals zero, *val
remains unchanged. Depending on the implementation it might be
uninitialized. Fixing users of oprofilefs_ulong_ from_user().

We missed these s390 changes with:

 913050b oprofile: Fix uninitialized memory access when writing to writing to oprofilefs

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ahci: Add alternate identifier for the 88SE9172

commit 17c60c6b763cb5b83b0185e7d38d01d18e55a05a upstream.

This can also appear as 0x9192. Reported in bugzilla and confirmed with the
board documentation for these boards.

Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=42970
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kobject: fix oops with "input0: bad kobj_uevent_env content in show_uevent()"

commit 60e233a56609fd963c59e99bd75c663d63fa91b6 upstream.

Fengguang Wu <fengguang.wu@intel.com> writes:

> After the __devinit* removal series, I can still get kernel panic in
> show_uevent(). So there are more sources of bug..
>
> Debug patch:
>
> @@ -343,8 +343,11 @@ static ssize_t show_uevent(struct device
>                 goto out;
>
>         /* copy keys to file */
> -       for (i = 0; i < env->envp_idx; i++)
> +       dev_err(dev, "uevent %d env[%d]: %s/.../%s\n", env->buflen, env->envp_idx, top_kobj->name, dev->kobj.name);
> +       for (i = 0; i < env->envp_idx; i++) {
> +               printk(KERN_ERR "uevent %d env[%d]: %s\n", (int)count, i, env->envp[i]);
>                 count += sprintf(&buf[count], "%s\n", env->envp[i]);
> +       }
>
> Oops message, the env[] is again not properly initilized:
>
> [   44.068623] input input0: uevent 61 env[805306368]: input0/.../input0
> [   44.069552] uevent 0 env[0]: (null)

This is a completely different CONFIG_HOTPLUG problem, only
demonstrating another reason why CONFIG_HOTPLUG should go away.  I had a
hard time trying to disable it anyway ;-)

The problem this time is lots of code assuming that a call to
add_uevent_var() will guarantee that env->buflen > 0.  This is not true
if CONFIG_HOTPLUG is unset.  So things like this end up overwriting
env->envp_idx because the array index is -1:

	if (add_uevent_var(env, "MODALIAS="))
		return -ENOMEM;
        len = input_print_modalias(&env->buf[env->buflen - 1],
				   sizeof(env->buf) - env->buflen,
				   dev, 0);

Don't know what the best action is, given that there seem to be a *lot*
of this around the kernel.  This patch "fixes" the problem for me, but I
don't know if it can be considered an appropriate fix.

[ It is the correct fix for now, for 3.7 forcing CONFIG_HOTPLUG to
always be on is the longterm fix, but it's too late for 3.6 and older
kernels to resolve this that way - gregkh ]

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Redefine ATOMIC_INIT and ATOMIC64_INIT to drop the casts

commit 67a806d9499353fabd5b5ff07337f3aa88a1c3ba upstream.

The following build error occurred during an alpha build:

  net/core/sock.c:274:36: error: initializer element is not constant

Dave Anglin says:
> Here is the line in sock.i:
>
> struct static_key memalloc_socks = ((struct static_key) { .enabled =
> ((atomic_t) { (0) }) });

The above line contains two compound literals.  It also uses a designated
initializer to initialize the field enabled.  A compound literal is not a
constant expression.

The location of the above statement isn't fully clear, but if a compound
literal occurs outside the body of a function, the initializer list must
consist of constant expressions.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
digsig: add hash size comparision on signature verification

commit bc01637a80f5b670bd70a0279d3f93fa8de1c96d upstream.

When pkcs_1_v1_5_decode_emsa() returns without error and hash sizes do
not match, hash comparision is not done and digsig_verify_rsa() returns
no error.  This is a bug and this patch fixes it.

The bug was introduced in v3.3 by commit b35e286a640f ("lib/digsig:
pkcs_1_v1_5_decode_emsa cleanup").

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
md: Don't truncate size at 4TB for RAID0 and Linear

commit 667a5313ecd7308d79629c0738b0db588b0b0a4e upstream.

commit 27a7b260f71439c40546b43588448faac01adb93
   md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.

changed 0.90 metadata handling to truncated size to 4TB as that is
all that 0.90 can record.
However for RAID0 and Linear, 0.90 doesn't need to record the size, so
this truncation is not needed and causes working arrays to become too small.

So avoid the truncation for RAID0 and Linear

This bug was introduced in 3.1 and is suitable for any stable kernels
from then onwards.
As the offending commit was tagged for 'stable', any stable kernel
that it was applied to should also get this patch.  That includes
at least 2.6.32, 2.6.33 and 3.0. (Thanks to Ben Hutchings for
providing that list).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
md: make sure metadata is updated when spares are activated or removed.

commit 6dafab6b1383e912cd252fa809570b484eb6e0dc upstream.

It isn't always necessary to update the metadata when spares are
removed as the presence-or-not of a spare isn't really important to
the integrity of an array.
Also activating a spare doesn't always require updating the metadata
as the update on 'recovery-completed' is usually sufficient.

However the introduction of 'replacement' devices have made these
transitions sometimes more important.  For example the 'Replacement'
flag isn't cleared until the original device is removed, so we need
to ensure a metadata update after that 'spare' is removed.

So set MD_CHANGE_DEVS whenever a spare is activated or removed, to
complement the current situation where it is set when a spare is added
or a device is failed (or a number of other less common situations).

This is suitable for -stable as out-of-data metadata could lead
to data corruption.
This is only relevant for 3.3 and later 9when 'replacement' as
introduced.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
md/raid5: fix calculate of 'degraded' when a replacement becomes active.

commit e5c86471f933608db5d43679f84cb4346c32033e upstream.

When a replacement device becomes active, we mark the device that it
replaces as 'faulty' so that it can subsequently get removed.
However 'calc_degraded' only pays attention to the primary device, not
the replacement, so the array appears to become degraded, which is
wrong.

So teach 'calc_degraded' to consider any replacement if a primary
device is faulty.

This is suitable for -stable as an incorrect 'degraded' value can
confuse md and could lead to data corruption.
This is only relevant for 3.3 and later.

Reported-by: Robin Hill <robin@robinhill.me.uk>
Reported-by: John Drescher <drescherjm@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nbd: clear waiting_queue on shutdown

commit fded4e090c60100d709318896c79816d68d5b47d upstream.

Fix a serious but uncommon bug in nbd which occurs when there is heavy
I/O going to the nbd device while, at the same time, a failure (server,
network) or manual disconnect of the nbd connection occurs.

There is a small window between the time that the nbd_thread is stopped
and the socket is shutdown where requests can continue to be queued to
nbd's internal waiting_queue.  When this happens, those requests are
never completed or freed.

The fix is to clear the waiting_queue on shutdown of the nbd device, in
the same way that the nbd request queue (queue_head) is already being
cleared.

Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ASoC: samsung dma - Don't indicate support for pause/resume.

commit 57b2d68863f281737d8596cb3d76d89d9cc54fd8 upstream.

The pause and resume operations indicate that the stream can be
un-paused/resumed from the exact location they were paused/suspended.
This is not true for this driver, the pause and suspend triggers share
the same code path with stop, they flush all pending DMA transfers.
This drops all pending samples.  The pause_release/resume triggers are
the same as start, except that prepare won't be called beforehand,
nothing will be enqueued to the DMA engine and nothing will happen (no
audio).  Removing the pause flag will let apps know that it isn't
supported.  Removing the resume flag will cause user space to call
prepare and start instead of resume, so audio will continue playing when
the system wakes up.

Before removing the pause and resume flags, I tested this on an exynos
5250, using 'aplay -i'. Pause/un-pause leads to silence followed by a
write error.  Suspend/resume testing led to the same result.  Removing
the two flags fixes suspend/resume (since snd_pcm_prepare is called
again). And leads to a proper reporting of pause not supported.

Signed-off-by: Dylan Reid <dgreid@chromium.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/page_alloc: fix the page address of higher page's buddy calculation

commit 0ba8f2d59304dfe69b59c034de723ad80f7ab9ac upstream.

The heuristic method for buddy has been introduced since commit
43506fad21ca ("mm/page_alloc.c: simplify calculation of combined index
of adjacent buddy lists").  But the page address of higher page's buddy
was wrongly calculated, which will lead page_is_buddy to fail for ever.
IOW, the heuristic method would be disabled with the wrong page address
of higher page's buddy.

Calculating the page address of higher page's buddy should be based
higher_page with the offset between index of higher page and index of
higher page's buddy.

Signed-off-by: Haifeng Li <omycle@gmail.com>
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KyongHo Cho <pullip.cho@samsung.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/rtc/rtc-twl.c: ensure all interrupts are disabled during probe

commit 8dcebaa9a0ae8a0487f4342f3d56d2cb1c980860 upstream.

On some platforms, bootloaders are known to do some interesting RTC
programming.  Without going into the obscurities as to why this may be
the case, suffice it to say the the driver should not make any
assumptions about the state of the RTC when the driver loads.  In
particular, the driver probe should be sure that all interrupts are
disabled until otherwise programmed.

This was discovered when finding bursty I2C traffic every second on
Overo platforms.  This I2C overhead was keeping the SoC from hitting
deep power states.  The cause was found to be the RTC firing every
second on the I2C-connected TWL PMIC.

Special thanks to Felipe Balbi for suggesting to look for a rogue driver
as the source of the I2C traffic rather than the I2C driver itself.

Special thanks to Steve Sakoman for helping track down the source of the
continuous RTC interrups on the Overo boards.

Signed-off-by: Kevin Hilman <khilman@ti.com>
Cc: Felipe Balbi <balbi@ti.com>
Tested-by: Steve Sakoman <steve@sakoman.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Tested-by: Shubhrajyoti Datta <omaplinuxkernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hwmon: (twl4030-madc-hwmon) Initialize uninitialized structure elements

commit 73d7c119255615a26070f9d6cdb722a166a29015 upstream.

twl4030_madc_conversion uses do_avg and type structure elements of
twl4030_madc_request. Initialize structure to avoid random operation.

Fix for: Coverity CID 200794 Uninitialized scalar variable.

Cc: Keerthy <j-keerthy@ti.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sched: Add missing call to calc_load_exit_idle()

commit 749c8814f08f12baa4a9c2812a7c6ede7d69507d upstream.

Azat Khuzhin reported high loadavg in Linux v3.6

After checking the upstream scheduler code, I found Peter's commit:

  5167e8d5417b sched/nohz: Rewrite and fix load-avg computation -- again

not fully applied, missing the call to calc_load_exit_idle().

After that idle exit in sampling window will always be calculated
to non-idle, and the load will be higher than normal.

This patch adds the missing call to calc_load_exit_idle().

Signed-off-by: Charles Wang <muming.wq@taobao.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1345449754-27130-1-git-send-email-muming.wq@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
can: mcp251x: avoid repeated frame bug

commit cab32f39dcc5b35db96497dc0a026b5dea76e4e7 upstream.

The MCP2515 has a silicon bug causing repeated frame transmission, see section
5 of MCP2515 Rev. B Silicon Errata Revision G (March 2007).

Basically, setting TXBnCTRL.TXREQ in either SPI mode (00 or 11) will eventually
cause the bug. The workaround proposed by Microchip is to use mode 00 and send
a RTS command on the SPI bus to initiate the transmission.

Signed-off-by: Benoît Locher <Benoit.Locher@skf.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/ia64: fix a memory block size bug

commit 05cf96398e1b6502f9e191291b715c7463c9d5dd upstream.

I found following definition in include/linux/memory.h, in my IA64
platform, SECTION_SIZE_BITS is equal to 32, and MIN_MEMORY_BLOCK_SIZE
will be 0.

  #define MIN_MEMORY_BLOCK_SIZE     (1 << SECTION_SIZE_BITS)

Because MIN_MEMORY_BLOCK_SIZE is int type and length of 32bits,
so MIN_MEMORY_BLOCK_SIZE(1 << 32) will will equal to 0.
Actually when SECTION_SIZE_BITS >= 31, MIN_MEMORY_BLOCK_SIZE will be wrong.
This will cause wrong system memory infomation in sysfs.
I think it should be:

  #define MIN_MEMORY_BLOCK_SIZE     (1UL << SECTION_SIZE_BITS)

And "echo offline > memory0/state" will cause following call trace:

  kernel BUG at mm/memory_hotplug.c:885!
  sh[6455]: bugcheck! 0 [1]
  Pid: 6455, CPU 0, comm:                   sh
  psr : 0000101008526030 ifs : 8000000000000fa4 ip  : [<a0000001008c40f0>]    Not tainted (3.6.0-rc1)
  ip is at offline_pages+0x210/0xee0
  Call Trace:
    show_stack+0x80/0xa0
    show_regs+0x640/0x920
    die+0x190/0x2c0
    die_if_kernel+0x50/0x80
    ia64_bad_break+0x3d0/0x6e0
    ia64_native_leave_kernel+0x0/0x270
    offline_pages+0x210/0xee0
    alloc_pages_current+0x180/0x2a0

Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>