rng_get_data() returns the number of bytes read from the hardware.
The entropy argument to add_hwgenerator_randomness() is passed
directly to credit_entropy_bits() so we should be passing the
number of bits, not bytes here.

Fixes: be4000bc

 "hwrng: create filler thread"
Acked-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

For people who don't trust a hardware RNG which can not be audited,
the changes to add support for RDSEED can be troubling since 97% or
more of the entropy will be contributed from the in-CPU hardware RNG.

We now have a in-kernel khwrngd, so for those people who do want to
implicitly trust the CPU-based system, we could create an arch-rng
hw_random driver, and allow khwrng refill the entropy pool.  This
allows system administrator whether or not they trust the CPU (I
assume the NSA will trust RDRAND/RDSEED implicitly :-), and if so,
what level of entropy derating they want to use.

The reason why this is a really good idea is that if different people
use different levels of entropy derating, it will make it much more
difficult to design a backdoor'ed hwrng that can be generally
exploited in terms of the output of /dev/random when different attack
targets are using differing levels of entropy derating.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

The getrandom(2) system call was requested by the LibreSSL Portable
developers.  It is analoguous to the getentropy(2) system call in
OpenBSD.

The rationale of this system call is to provide resiliance against
file descriptor exhaustion attacks, where the attacker consumes all
available file descriptors, forcing the use of the fallback code where
/dev/[u]random is not available.  Since the fallback code is often not
well-tested, it is better to eliminate this potential failure mode
entirely.

The other feature provided by this new system call is the ability to
request randomness from the /dev/urandom entropy pool, but to block
until at least 128 bits of entropy has been accumulated in the
/dev/urandom entropy pool.  Historically, the emphasis in the
/dev/urandom development has been to ensure that urandom pool is
initialized as quickly as possible after system boot, and preferably
before the init scripts start execution.

This is because changing /dev/urandom reads to block represents an
interface change that could potentially break userspace which is not
acceptable.  In practice, on most x86 desktop and server systems, in
general the entropy pool can be initialized before it is needed (and
in modern kernels, we will printk a warning message if not).  However,
on an embedded system, this may not be the case.  And so with this new
interface, we can provide the functionality of blocking until the
urandom pool has been initialized.  Any userspace program which uses
this new functionality must take care to assure that if it is used
during the boot process, that it will not cause the init scripts or
other portions of the system startup to hang indefinitely.

SYNOPSIS
	#include <linux/random.h>

	int getrandom(void *buf, size_t buflen, unsigned int flags);

DESCRIPTION
	The system call getrandom() fills the buffer pointed to by buf
	with up to buflen random bytes which can be used to seed user
	space random number generators (i.e., DRBG's) or for other
	cryptographic uses.  It should not be used for Monte Carlo
	simulations or other programs/algorithms which are doing
	probabilistic sampling.

	If the GRND_RANDOM flags bit is set, then draw from the
	/dev/random pool instead of the /dev/urandom pool.  The
	/dev/random pool is limited based on the entropy that can be
	obtained from environmental noise, so if there is insufficient
	entropy, the requested number of bytes may not be returned.
	If there is no entropy available at all, getrandom(2) will
	either block, or return an error with errno set to EAGAIN if
	the GRND_NONBLOCK bit is set in flags.

	If the GRND_RANDOM bit is not set, then the /dev/urandom pool
	will be used.  Unlike using read(2) to fetch data from
	/dev/urandom, if the urandom pool has not been sufficiently
	initialized, getrandom(2) will block (or return -1 with the
	errno set to EAGAIN if the GRND_NONBLOCK bit is set in flags).

	The getentropy(2) system call in OpenBSD can be emulated using
	the following function:

            int getentropy(void *buf, size_t buflen)
            {
                    int     ret;

                    if (buflen > 256)
                            goto failure;
                    ret = getrandom(buf, buflen, 0);
                    if (ret < 0)
                            return ret;
                    if (ret == buflen)
                            return 0;
            failure:
                    errno = EIO;
                    return -1;
            }

RETURN VALUE
       On success, the number of bytes that was filled in the buf is
       returned.  This may not be all the bytes requested by the
       caller via buflen if insufficient entropy was present in the
       /dev/random pool, or if the system call was interrupted by a
       signal.

       On error, -1 is returned, and errno is set appropriately.

ERRORS
	EINVAL		An invalid flag was passed to getrandom(2)

	EFAULT		buf is outside the accessible address space.

	EAGAIN		The requested entropy was not available, and
			getentropy(2) would have blocked if the
			GRND_NONBLOCK flag was not set.

	EINTR		While blocked waiting for entropy, the call was
			interrupted by a signal handler; see the description
			of how interrupted read(2) calls on "slow" devices
			are handled with and without the SA_RESTART flag
			in the signal(7) man page.

NOTES
	For small requests (buflen <= 256) getrandom(2) will not
	return EINTR when reading from the urandom pool once the
	entropy pool has been initialized, and it will return all of
	the bytes that have been requested.  This is the recommended
	way to use getrandom(2), and is designed for compatibility
	with OpenBSD's getentropy() system call.

	However, if you are using GRND_RANDOM, then getrandom(2) may
	block until the entropy accounting determines that sufficient
	environmental noise has been gathered such that getrandom(2)
	will be operating as a NRBG instead of a DRBG for those people
	who are working in the NIST SP 800-90 regime.  Since it may
	block for a long time, these guarantees do *not* apply.  The
	user may want to interrupt a hanging process using a signal,
	so blocking until all of the requested bytes are returned
	would be unfriendly.

	For this reason, the user of getrandom(2) MUST always check
	the return value, in case it returns some error, or if fewer
	bytes than requested was returned.  In the case of
	!GRND_RANDOM and small request, the latter should never
	happen, but the careful userspace code (and all crypto code
	should be careful) should check for this anyway!

	Finally, unless you are doing long-term key generation (and
	perhaps not even then), you probably shouldn't be using
	GRND_RANDOM.  The cryptographic algorithms used for
	/dev/urandom are quite conservative, and so should be
	sufficient for all purposes.  The disadvantage of GRND_RANDOM
	is that it can block, and the increased complexity required to
	deal with partially fulfilled getrandom(2) requests.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Zach Brown <zab@zabbo.net>

Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

For CPU's that don't have a cycle counter, or something equivalent
which can be used for random_get_entropy(), random_get_entropy() will
always return 0.  In that case, substitute with the saved interrupt
registers to add a bit more unpredictability.

Some folks have suggested hashing all of the registers
unconditionally, but this would increase the overhead of
add_interrupt_randomness() by at least an order of magnitude, and this
would very likely be unacceptable.

The changes in this commit have been benchmarked as mostly unaffecting
the overhead of add_interrupt_randomness() if the entropy counter is
present, and doubling the overhead if it is not present.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: Jörn Engel <joern@logfs.org>

This patch introduces a derating factor to struct hwrng for
the random bits going into the kernel input pool, and a common
default derating for drivers which do not specify one.

Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: H. Peter Anvin <hpa@zytor.com>

This can be viewed as the in-kernel equivalent of hwrngd;
like FUSE it is a good thing to have a mechanism in user land,
but for some reasons (simplicity, secrecy, integrity, speed)
it may be better to have it in kernel space.

This patch creates a thread once a hwrng registers, and uses
the previously established add_hwgenerator_randomness() to feed
its data to the input pool as long as needed. A derating factor
is used to bias the entropy estimation and to disable this
mechanism entirely when set to zero.

Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: H. Peter Anvin <hpa@zytor.com>

This patch adds an interface to the random pool for feeding entropy
in-kernel.

Signed-off-by: Torsten Duwe <duwe@suse.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: H. Peter Anvin <hpa@zytor.com>

Use more efficient fast_mix() function.  Thanks to George Spelvin for
doing the leg work to find a more efficient mixing function.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: George Spelvin <linux@horizon.com>

For architectures that don't have cycle counters, the algorithm for
deciding when to avoid giving entropy credit due to back-to-back timer
interrupts didn't make any sense, since we were checking every 64
interrupts.  Change it so that we only give an entropy credit if the
majority of the interrupts are not based on the timer.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: George Spelvin <linux@horizon.com>

In xfer_secondary_pull(), check to make sure we need to pull from the
secondary pool before checking and potentially updating the
last_pulled time.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: George Spelvin <linux@horizon.com>

We previously extracted a portion of the entropy pool in
mix_pool_bytes() and hashed it in to avoid racing CPU's from returning
duplicate random values.  Now that we are using a spinlock to prevent
this from happening, this is no longer necessary.  So remove it, to
simplify the code a bit.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: George Spelvin <linux@horizon.com>

Instead of using lockless techniques introduced in commit
902c098a

, use spin_trylock to try to grab entropy pool's lock.  If
we can't get the lock, then just try again on the next interrupt.

Based on discussions with George Spelvin.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: George Spelvin <linux@horizon.com>

Pull ext4 bugfixes from Ted Ts'o:
 "More bug fixes for ext4 -- most importantly, a fix for a bug
  introduced in 3.15 that can end up triggering a file system corruption
  error after a journal replay.

  It shouldn't lead to any actual data corruption, but it is scary and
  can force file systems to be remounted read-only, etc"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix potential null pointer dereference in ext4_free_inode
  ext4: fix a potential deadlock in __ext4_es_shrink()
  ext4: revert commit which was causing fs corruption after journal replays
  ext4: disable synchronous transaction batching if max_batch_time==0
  ext4: clarify ext4_error message in ext4_mb_generate_buddy_error()
  ext4: clarify error count warning messages
  ext4: fix unjournalled bg descriptor while initializing inode bitmap

Pull clock driver fixes from Mike Turquette:
 "This batch of fixes is for a handful of clock drivers from Allwinner,
  Samsung, ST & TI.  Most of them are of the "this hardware won't work
  without this fix" variety, including patches that fix platforms that
  did not boot under certain configurations.  Other fixes are the result
  of changes to the clock core introduced in 3.15 that had subtle
  impacts on the clock drivers.

  There are no fixes to the clock framework core in this pull request"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: spear3xx: Set proper clock parent of uart1/2
  clk: spear3xx: Use proper control register offset
  clk: qcom: HDMI source sel is 3 not 2
  clk: sunxi: fix devm_ioremap_resource error detection code
  clk: s2mps11: Fix double free corruption during driver unbind
  clk: ti: am43x: Fix boot with CONFIG_SOC_AM33XX disabled
  clk: exynos5420: Remove aclk66_peric from the clock tree description
  clk/exynos5250: fix bit number for tv sysmmu clock
  clk: s3c64xx: Hookup SPI clocks correctly
  clk: samsung: exynos4: Remove SRC_MASK_ISP gates
  clk: samsung: add more aliases for s3c24xx
  clk: samsung: fix several typos to fix boot on s3c2410
  clk: ti: set CLK_SET_RATE_NO_REPARENT for ti,mux-clock
  clk: ti: am43x: Fix boot with CONFIG_SOC_AM33XX disabled
  clk: ti: dra7: return error code in failure case
  clk: ti: apll: not allocating enough data

Pull ARM SoC fixes from Olof Johansson:
 "This week's arm-soc fixes:

   - Another set of OMAP fixes
     * Clock fixes
     * Restart handling
     * PHY regulators
     * SATA hwmod data for DRA7
     + Some trivial fixes and removal of a bit of dead code
   - Exynos fixes
     * A bunch of clock fixes
     * Some SMP fixes
     * Exynos multi-core timer: register as clocksource and fix ftrace.
     + a few other minor fixes

  There's also a couple more patches, and at91 fix for USB caused by
  common clock conversion, and more MAINTAINERS entries for shmobile.

  We're definitely switching to only regression fixes from here on out,
  we've been a little less strict than usual up until now"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (26 commits)
  ARM: at91: at91sam9x5: add clocks for usb device
  ARM: EXYNOS: Register cpuidle device only on exynos4210 and 5250
  ARM: dts: Add clock property for mfc_pd in exynos5420
  clk: exynos5420: Add IDs for clocks used in PD mfc
  ARM: EXYNOS: Add support for clock handling in power domain
  ARM: OMAP2+: Remove non working OMAP HDMI audio initialization
  ARM: imx: fix shared gate clock
  ARM: dts: Update the parent for Audss clocks in Exynos5420
  ARM: EXYNOS: Update secondary boot addr for secure mode
  ARM: dts: Fix TI CPSW Phy mode selection on IGEP COM AQUILA.
  ARM: dts: am335x-evmsk: Enable the McASP FIFO for audio
  ARM: dts: am335x-evm: Enable the McASP FIFO for audio
  ARM: OMAP2+: Make GPMC skip disabled devices
  ARM: OMAP2+: create dsp device only on OMAP3 SoCs
  ARM: dts: dra7-evm: Make VDDA_1V8_PHY supply always on
  ARM: DRA7/AM43XX: fix header definition for omap44xx_restart
  ARM: OMAP2+: clock/dpll: fix _dpll_test_fint arithmetics overflow
  ARM: DRA7: hwmod: Add SYSCONFIG for usb_otg_ss
  ARM: DRA7: hwmod: Fixup SATA hwmod
  ARM: OMAP3: PRM/CM: Add back macros used by TI DSP/Bridge driver
  ...

Pull ARM fixes from Russell King:
 "Another round of fixes for ARM:
   - a set of kprobes fixes from Jon Medhurst
   - fix the revision checking for the L2 cache which wasn't noticed to
     have been broken"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: l2c: fix revision checking
  ARM: kprobes: Fix test code compilation errors for ARMv4 targets
  ARM: kprobes: Disallow instructions with PC and register specified shift
  ARM: kprobes: Prevent known test failures stopping other tests running

Pull m68k fixes from Geert Uytterhoeven:
 "Summary:
  - Fix for a boot regression introduced in v3.16-rc1,
  - Fix for a build issue in -next"

Christoph Hellwig questioned why mach_random_get_entropy should be
exported to modules, and Geert explains that random_get_entropy() is
called by at least the crypto layer and ends up using it on m68k.  On
most other architectures it just uses get_cycles() (which is typically
inlined and doesn't need exporting),

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Export mach_random_get_entropy to modules
  m68k: Fix boot regression on machines with RAM at non-zero

Pull parisc fixes from Helge Deller:
 "The major patch in here is one which fixes the fanotify_mark() syscall
  in the compat layer of the 64bit parisc kernel.  It went unnoticed so
  long, because the calling syntax when using a 64bit parameter in a
  32bit syscall is quite complex and even worse, it may be even
  different if you call syscall() or the glibc wrapper.  This patch
  makes the kernel accept the calling convention when called by the
  glibc wrapper.

  The other two patches are trivial and remove unused headers, #includes
  and adds the serial ports of the fastest C8000 workstation to the
  parisc-kernel internal hardware database"

* 'parisc-3.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: drop unused defines and header includes
  parisc: fix fanotify_mark() syscall on 32bit compat kernel
  parisc: add serial ports of C8000/1GHz machine to hardware database

The uarts only work when the parent is ras_ahb_clk. The stale 3.5
based ST tree does this in the board file.

Add it to the clk init function. Not pretty, but the mess there is
amazing anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

The control register is at offset 0x10, not 0x0. This is wreckaged
since commit 5df33a62

 (SPEAr: Switch to common clock framework).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+

On parisc we can not use the existing compat implementation for fanotify_mark()
because for the 64bit mask parameter the higher and lower 32bits are ordered
differently than what the compat function expects from big endian
architectures.

Specifically:
It finally turned out, that on hppa we end up with different assignments
of parameters to kernel arguments depending on if we call the glibc
wrapper function
 int fanotify_mark (int __fanotify_fd, unsigned int __flags,
                    uint64_t __mask, int __dfd, const char *__pathname);
or directly calling the syscall manually
 syscall(__NR_fanotify_mark, ...)

Reason is, that the syscall() function is implemented as C-function and
because we now have the sysno as first parameter in front of the other
parameters the compiler will unexpectedly add an empty paramenter in
front of the u64 value to ensure the correct calling alignment for 64bit
values.
This means, on hppa you can't simply use syscall() to call the kernel
fanotify_mark() function directly, but you have to use the glibc
function instead.

This patch fixes the kernel in the hppa-arch specifc coding to adjust
the parameters in a way as if userspace calls the glibc wrapper function
fanotify_mark().

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+

Pull slave-dmaengine fixes from Vinod Koul:
 "We have two small fixes.  First one from Daniel to handle 0-length
  packets for usb cppi dma.  Second by Russell for imx-sdam cyclic
  residue reporting"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  Update imx-sdma cyclic handling to report residue
  dma: cppi41: handle 0-length packets

Merge tag 'samsung-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into fixes

Merge "Samsung fixes-3 for 3.16" from Kukjin Kim:

Samsung fixes-3 for v3.16
- update the parent for Auudss clock because kernel will be hang
  during late boot if the parent clock is disabled in bootloader.
- enable clk handing in power domain because while power domain
  on/off, its regarding clock source will be reset and it causes
  a problem so need to handle it.
- add mux clocks to be used by power domain for exynos5420-mfc
  during power domain on/off and property in device tree also.
- register cpuidle only for exynos4210 and exynos5250 because a
  system failure will be happened on other exynos SoCs.

* tag 'samsung-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung

:
  ARM: EXYNOS: Register cpuidle device only on exynos4210 and 5250
  ARM: dts: Add clock property for mfc_pd in exynos5420
  clk: exynos5420: Add IDs for clocks used in PD mfc
  ARM: EXYNOS: Add support for clock handling in power domain
  ARM: dts: Update the parent for Audss clocks in Exynos5420

Signed-off-by: Olof Johansson <olof@lixom.net>

Pull USB fixes from Greg KH:
 "Here are some small USB fixes, PHY driver fixes (they ended up in this
  tree for lack of somewhere else to put them), and some new USB device
  ids"

* tag 'usb-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  phy: omap-usb2: Balance pm_runtime_enable() on probe failure and remove
  phy: core: Fix error path in phy_create()
  drivers: phy: phy-samsung-usb2.c: Add missing MODULE_DEVICE_TABLE
  phy: omap-usb2: fix devm_ioremap_resource error detection code
  phy: sun4i: depend on RESET_CONTROLLER
  USB: serial: ftdi_sio: Add Infineon Triboard
  USB: ftdi_sio: Add extra PID.
  usb: option: Add ID for Telewell TW-LTE 4G v2
  USB: cp210x: add support for Corsair usb dongle

Pull tty/serial fixes from Greg KH:
 "Here are some small serial fixes that resolve some reported problems
  that started in 3.15 with some serial drivers.

  And there's a new dt binding for a serial driver, which was all that
  was needed for the renesas serial driver"

* tag 'tty-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: sh-sci: Add device tree support for r8a7{778,740,3a4} and sh73a0
  serial: imx: Fix build breakage
  serial: arc_uart: Use uart_circ_empty() for open-coded comparison
  serial: Test for no tx data on tx restart

Pull char/misc driver fixes from Greg KH:
 "Here are two hyperv driver fixes, and one i8k driver fix for 3.16"

* tag 'char-misc-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  i8k: Fix non-SMP operation
  Drivers: hv: util: Fix a bug in the KVP code
  Drivers: hv: vmbus: Fix a bug in the channel callback dispatch code

Pull IIO fixes from Greg KH:
 "Here are some IIO driver fixes for 3.16-rc5.  Nothing major, just
  resolves some minor issues that have been reported"

* tag 'staging-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: ti_am335x_adc: Fix: Use same step id at FIFOs both ends
  iio:tcs3472: Check for buffer enabled and locking
  iio: hid-sensor-prox: Fix return values
  iio: hid-sensor-gyro-3d: Fix return values
  iio: hid-sensor-als: Fix return values
  iio: hid-sensor-magn-3d: Fix return values
  iio: hid-sensor-accel-3d: Fix return values
  iio: hid-sensor-press: Fix return values

Fix potential null pointer dereferencing problem caused by e43bb4e6


("ext4: decrement free clusters/inodes counters when block group declared bad")

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>

This fixes the following lockdep complaint:

[ INFO: possible circular locking dependency detected ]
3.16.0-rc2-mm1+ #7 Tainted: G           O  
-------------------------------------------------------
kworker/u24:0/4356 is trying to acquire lock:
 (&(&sbi->s_es_lru_lock)->rlock){+.+.-.}, at: [<ffffffff81285fff>] __ext4_es_shrink+0x4f/0x2e0

but task is already holding lock:
 (&ei->i_es_lock){++++-.}, at: [<ffffffff81286961>] ext4_es_insert_extent+0x71/0x180

which lock already depends on the new lock.

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_es_lock);
                               lock(&(&sbi->s_es_lru_lock)->rlock);
                               lock(&ei->i_es_lock);
  lock(&(&sbi->s_es_lru_lock)->rlock);

 *** DEADLOCK ***

6 locks held by kworker/u24:0/4356:
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff81071d00>] process_one_work+0x180/0x560
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff81071d00>] process_one_work+0x180/0x560
 #2:  (&type->s_umount_key#22){++++++}, at: [<ffffffff811a9c74>] grab_super_passive+0x44/0x90
 #3:  (jbd2_handle){+.+...}, at: [<ffffffff812979f9>] start_this_handle+0x189/0x5f0
 #4:  (&ei->i_data_sem){++++..}, at: [<ffffffff81247062>] ext4_map_blocks+0x132/0x550
 #5:  (&ei->i_es_lock){++++-.}, at: [<ffffffff81286961>] ext4_es_insert_extent+0x71/0x180

stack backtrace:
CPU: 0 PID: 4356 Comm: kworker/u24:0 Tainted: G           O   3.16.0-rc2-mm1+ #7
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: writeback bdi_writeback_workfn (flush-253:0)
 ffffffff8213dce0 ffff880014b07538 ffffffff815df0bb 0000000000000007
 ffffffff8213e040 ffff880014b07588 ffffffff815db3dd ffff880014b07568
 ffff880014b07610 ffff88003b868930 ffff88003b868908 ffff88003b868930
Call Trace:
 [<ffffffff815df0bb>] dump_stack+0x4e/0x68
 [<ffffffff815db3dd>] print_circular_bug+0x1fb/0x20c
 [<ffffffff810a7a3e>] __lock_acquire+0x163e/0x1d00
 [<ffffffff815e89dc>] ? retint_restore_args+0xe/0xe
 [<ffffffff815ddc7b>] ? __slab_alloc+0x4a8/0x4ce
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff810a8707>] lock_acquire+0x87/0x120
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff8128592d>] ? ext4_es_free_extent+0x5d/0x70
 [<ffffffff815e6f09>] _raw_spin_lock+0x39/0x50
 [<ffffffff81285fff>] ? __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff8119760b>] ? kmem_cache_alloc+0x18b/0x1a0
 [<ffffffff81285fff>] __ext4_es_shrink+0x4f/0x2e0
 [<ffffffff812869b8>] ext4_es_insert_extent+0xc8/0x180
 [<ffffffff812470f4>] ext4_map_blocks+0x1c4/0x550
 [<ffffffff8124c4c4>] ext4_writepages+0x6d4/0xd00
	...

Reported-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Minchan Kim <minchan@kernel.org>
Cc: stable@vger.kernel.org
Cc: Zheng Liu <gnehzuil.liu@gmail.com>

Dell kernel driver dell-smo8800 provides same freefall interface as hp_accel so
program hpfall.c works also on Dell laptops. So rename it to freefall.c.

Dell driver does not provide hp::hddprotect led so make sure that freefall.c
works also if hp::hddprotect does not exist in sysfs.

Additionally write info to syslog.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Cc: Sonal Santan <sonal.santan@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch fixed spelling typo in various template files
within Documentation/Docbook.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch fixed spelling typo found in DocBook/mtdnand.tmpl.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Object-like macros are different than function-like macros:
https://gcc.gnu.org/onlinedocs/cpp/Object-like-Macros.html
https://gcc.gnu.org/onlinedocs/cpp/Function-like-Macros.html



They are not parsed correctly, generating invalid intermediate
files (xmls) for cases like:
    #define BIT_MASK    (0xFF << BIT_SHIFT)
where "OxFF <<" is considered to be parameter type.

When parsing, we can differentiate beween these two types of macros by
checking whether there is at least one whitespace b/w "#define" and
first opening parenthesis.

Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The paragraph on mcelog currently describes kernel v2.6.31. In that
kernel the mce code (for i386, that is) was in transition. Ever since
v2.6.32 the situation is much simpler (eg, mcelog is now needed to
process events on almost all x86 machines, i386 and x86-64). Since this
"document is designed to provide a list of the minimum levels of
software necessary to run the 3.0 kernels" let's just describe that
situation.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add clocks for usb device, or else switch to CCF, the gadget
won't work.

Reported-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Tested-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Olof Johansson <olof@lixom.net>