Don't rely on internal Skylake-specific data structures, use
generic interface to let other drivers use the same machine driver
as is, e.g. SOF to support HDaudio codecs and HDMI outputs.

Tested on LeafHill CRB board, no regression seen with this change.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

The machine drivers may need information provided by the platform
driver.  Currently the information is passed using pdata specific to
each plaform driver. This prevents other drivers, such as SOF, from
reusing machine drivers directly.

Add a new structure which contains the required fields.

This proposal requires a bit more work on the platform side but this
generic interface helps reuse code directly.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Enabling both the old AC97_BUS code and the new AC97_BUS_COMPAT causes
problems because both modules provide an exported snd_ac97_reset()
function.

I had tried to fix the problem of having both coexist earlier, but
my patch only prevented them from being built-in. This is because
of a special Kconfig feature that lets a symbol have a dependency
on another one being disabled, but still allow both to be loadable
modules.

Changing the dependency to =n avoids that problem, now we can only
build the new driver if the old one is completely disabled.

If we could figure out a way to let rename one of the reset
functions and have each driver link to exactly the old or
the compat code, that would also work, but I could not find if
that's possible.

Fixes: bec5ecdf ("ASoC: pxa: avoid AC97_BUS build warning")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

The audio support is done via simple-audio-card via DT, the custom driver
is no longer needed.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

"DACn Zero Flag" and "ADCn Overflow Flag" are read-only status
register. These information are needed for driver not for user.
Let's remove these from snd_kcontrol_new.

There is no detail explanation for these register on
datasheet, but, judging from its behavior, it seems these register
needs clock to read. Otherwise, I2C returns error.
Therefor, amixer command will be failed under non working timing.

Without this patch, user often fail amixer command.
This patch is tested on R-Car H3 ulcb-kf board, SSI3/4 TDM sound.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

snd_soc_component_update_bits() will only update the mask bits,
so remove the redundant snd_soc_component_read32().
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Current rsnd driver is using "%s[%d]" for mod name and ID,
but, this ID portion might confusable.
For example currently, CTU ID is 0 to 7, but using 00 to 13
(= 00, 01, 02, 03, 10, 11, 12, 13) is very best matching to datasheet.

In the future, we will support BUSIFn, but it will be more complicated
numbering. To avoid future confusable code, this patch modify
rsnd_mod_name() to return understandable name.

To avoid using pointless memory, it uses static char and snprintf,
thus, rsnd_mod_name() user should use it immediately, and shouldn't keep
its pointer.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

ID for CTU and SSIU are confusable.
1 CTU has 4 sub nodes. This means, CTU0 has CTU01 - CTU03, CTU1 has
CTU10 - CTU13. SSIU is more confusable. Gen2 SSIU has BUSIF0-3, Gen3
SSIU has BUSIF0-7, but not for all SSIU.
In rsnd driver, each mod drivers are assuming rsnd_mod_id() returns
main device ID (In CTU case CTU0-1, SSIU case SSIU0-9), not serial
number.
This patch adds new .id/.id_sub to handling more detail ID.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Each mod needs to have .get_status, but current driver is handling it
under rsnd_mod, instead of rsnd_mod_ops.
It is not any make sence. This patch moves it to rsnd_mod_ops, and
tidyup its parameter order to align to other callback functions.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

hw constraint for LEFT_J/I2S are same, but had duplicated code.
This code cleanup these.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

For samples sizes of 20/24/32 bit the DRR2/DXR2 registers must be used to
receive or transmit the most significant part of the 32bit sample.
We can not trick the system by using the DRR2/DXR2 register offset and use
32bit element size since these (and other McBSP) registers are 16bit ones.

We would need support for port_window in cyclic mode from the sDMA driver,
but it is not straight forward as we would need to have the sDMA frame to
cover the 32bit (DRR2+DRR1/DXR2+DXR1), but the frames must cover the ALSA
period to be able to receive periodic interrupts.

Since the 32bit samples are not working (DMA timeout), just remove it in
case we have McBSP with reg_size of 2.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

The regulator_desc structure can be const as it is only passed as the
second argument of devm_regulator_register and the corresponding
parameter is declared as const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

The snd_soc_dai_ops structures are only stored in the ops field of a
snd_soc_dai_driver structure, so make the snd_soc_dai_ops structures
const as well.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

The snd_soc_dai_ops structures are only stored in the ops field of a
snd_soc_dai_driver structure, so make the snd_soc_dai_ops structures
const as well.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

WARN_ON() already contains an unlikely(), so it's not necessary to use
unlikely.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Randconfig testing revealed a very old bug, with gcc-8:

sound/soc/intel/atom/sst/sst_loader.c: In function 'sst_load_fw':
sound/soc/intel/atom/sst/sst_loader.c:357:5: error: 'fw' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  if (fw == NULL) {
     ^
sound/soc/intel/atom/sst/sst_loader.c:354:25: note: 'fw' was declared here
  const struct firmware *fw;

We must check the return code of request_firmware() before we look at the
pointer result that may be uninitialized when the function fails.

Fixes: 9012c954 ("ASoC: Intel: mrfld - Add DSP load and management")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

gcc notices that without either the ac97 bus or the pdata, we never
initialize the regmap pointer, which leads to an uninitialized variable
access:

sound/soc/codecs/wm9712.c: In function 'wm9712_soc_probe':
sound/soc/codecs/wm9712.c:666:2: error: 'regmap' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Since that configuration is invalid, it's better to return an error
here. I tried to avoid adding complexity to the conditions, and turned
the #ifdef into a regular if(IS_ENABLED()) check for readability.
This in turn requires moving some header file declarations out of
an #ifdef.

The same code is used in three drivers, all of which I'm changing
the same way.

Fixes: 2ed1a8e0 ("ASoC: wm9712: add ac97 new bus support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

The snd_soc_ops structure can be const as it is only stored in the
ops field of a snd_soc_dai_link structure and this field is const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

Currently, the comparison of div < 0 is always false because div is
an unsigned int. Fix this by making div an int.

Detected by CoverityScan, CID#1475309 ("Unsigned compared against 0")

Fixes: 8307b2af "(ASoC: stm32: sai: set sai as mclk clock provider")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Pull UBIFS updates from Richard Weinberger:

 - Full filesystem authentication feature, UBIFS is now able to have the
   whole filesystem structure authenticated plus user data encrypted and
   authenticated.

 - Minor cleanups

* tag 'tags/upstream-4.20-rc1' of git://git.infradead.org/linux-ubifs: (26 commits)
  ubifs: Remove unneeded semicolon
  Documentation: ubifs: Add authentication whitepaper
  ubifs: Enable authentication support
  ubifs: Do not update inode size in-place in authenticated mode
  ubifs: Add hashes and HMACs to default filesystem
  ubifs: authentication: Authenticate super block node
  ubifs: Create hash for default LPT
  ubfis: authentication: Authenticate master node
  ubifs: authentication: Authenticate LPT
  ubifs: Authenticate replayed journal
  ubifs: Add auth nodes to garbage collector journal head
  ubifs: Add authentication nodes to journal
  ubifs: authentication: Add hashes to index nodes
  ubifs: Add hashes to the tree node cache
  ubifs: Create functions to embed a HMAC in a node
  ubifs: Add helper functions for authentication support
  ubifs: Add separate functions to init/crc a node
  ubifs: Format changes for authentication support
  ubifs: Store read superblock node
  ubifs: Drop write_node
  ...

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights include:

  Bugfix:
   - Fix build issues on architectures that don't provide 64-bit cmpxchg

  Cleanups:
   - Fix a spelling mistake"

* tag 'nfs-for-4.20-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFS: fix spelling mistake, EACCESS -> EACCES
  SUNRPC: Use atomic(64)_t for seq_send(64)

Pull more timer updates from Thomas Gleixner:
 "A set of commits for the new C-SKY architecture timers"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings: timer: gx6605s SOC timer
  clocksource/drivers/c-sky: Add gx6605s SOC system timer
  dt-bindings: timer: C-SKY Multi-processor timer
  clocksource/drivers/c-sky: Add C-SKY SMP timer

Pull NTB updates from Jon Mason:
 "Fairly minor changes and bug fixes:

  NTB IDT thermal changes and hook into hwmon, ntb_netdev clean-up of
  private struct, and a few bug fixes"

* tag 'ntb-4.20' of git://github.com/jonmason/ntb:
  ntb: idt: Alter the driver info comments
  ntb: idt: Discard temperature sensor IRQ handler
  ntb: idt: Add basic hwmon sysfs interface
  ntb: idt: Alter temperature read method
  ntb_netdev: Simplify remove with client device drvdata
  NTB: transport: Try harder to alloc an aligned MW buffer
  ntb: ntb_transport: Mark expected switch fall-throughs
  ntb: idt: Set PCIe bus address to BARLIMITx
  NTB: ntb_hw_idt: replace IS_ERR_OR_NULL with regular NULL checks
  ntb: intel: fix return value for ndev_vec_mask()
  ntb_netdev: fix sleep time mismatch

Pull scheduler fixes from Ingo Molnar:
 "A memory (under-)allocation fix and a comment fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/topology: Fix off by one bug
  sched/rt: Update comment in pick_next_task_rt()

Pull x86 fixes from Ingo Molnar:
 "A number of fixes and some late updates:

   - make in_compat_syscall() behavior on x86-32 similar to other
     platforms, this touches a number of generic files but is not
     intended to impact non-x86 platforms.

   - objtool fixes

   - PAT preemption fix

   - paravirt fixes/cleanups

   - cpufeatures updates for new instructions

   - earlyprintk quirk

   - make microcode version in sysfs world-readable (it is already
     world-readable in procfs)

   - minor cleanups and fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  compat: Cleanup in_compat_syscall() callers
  x86/compat: Adjust in_compat_syscall() to generic code under !COMPAT
  objtool: Support GCC 9 cold subfunction naming scheme
  x86/numa_emulation: Fix uniform-split numa emulation
  x86/paravirt: Remove unused _paravirt_ident_32
  x86/mm/pat: Disable preemption around __flush_tlb_all()
  x86/paravirt: Remove GPL from pv_ops export
  x86/traps: Use format string with panic() call
  x86: Clean up 'sizeof x' => 'sizeof(x)'
  x86/cpufeatures: Enumerate MOVDIR64B instruction
  x86/cpufeatures: Enumerate MOVDIRI instruction
  x86/earlyprintk: Add a force option for pciserial device
  objtool: Support per-function rodata sections
  x86/microcode: Make revision and processor flags world-readable

Pull perf updates and fixes from Ingo Molnar:
 "These are almost all tooling updates: 'perf top', 'perf trace' and
  'perf script' fixes and updates, an UAPI header sync with the merge
  window versions, license marker updates, much improved Sparc support
  from David Miller, and a number of fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (66 commits)
  perf intel-pt/bts: Calculate cpumode for synthesized samples
  perf intel-pt: Insert callchain context into synthesized callchains
  perf tools: Don't clone maps from parent when synthesizing forks
  perf top: Start display thread earlier
  tools headers uapi: Update linux/if_link.h header copy
  tools headers uapi: Update linux/netlink.h header copy
  tools headers: Sync the various kvm.h header copies
  tools include uapi: Update linux/mmap.h copy
  perf trace beauty: Use the mmap flags table generated from headers
  perf beauty: Wire up the mmap flags table generator to the Makefile
  perf beauty: Add a generator for MAP_ mmap's flag constants
  tools include uapi: Update asound.h copy
  tools arch uapi: Update asm-generic/unistd.h and arm64 unistd.h copies
  tools include uapi: Update linux/fs.h copy
  perf callchain: Honour the ordering of PERF_CONTEXT_{USER,KERNEL,etc}
  perf cs-etm: Correct CPU mode for samples
  perf unwind: Take pgoff into account when reporting elf to libdwfl
  perf top: Do not use overwrite mode by default
  perf top: Allow disabling the overwrite mode
  perf trace: Beautify mount's first pathname arg
  ...

Pull irq fixes from Ingo Molnar:
 "An irqchip driver fix and a memory (over-)allocation fix"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/irq-mvebu-sei: Fix a NULL vs IS_ERR() bug in probe function
  irq/matrix: Fix memory overallocation

With the addition of the NUMA identity level, we increased @level by
one and will run off the end of the array in the distance sort loop.

Fixed: 051f3ca0 ("sched/topology: Introduce NUMA identity node sched domain")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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

Pull ARM SoC fixes from Olof Johansson:
 "A few fixes who have come in near or during the merge window:

   - Removal of a VLA usage in Marvell mpp platform code

   - Enable some IPMI options for ARM64 servers by default, helps
     testing

   - Enable PREEMPT on 32-bit ARMv7 defconfig

   - Minor fix for stm32 DT (removal of an unused DMA property)

   - Bugfix for TI OMAP1-based ams-delta (-EINVAL -> IRQ_NOTCONNECTED)"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: stm32: update HASH1 dmas property on stm32mp157c
  ARM: orion: avoid VLA in orion_mpp_conf
  ARM: defconfig: Update multi_v7 to use PREEMPT
  arm64: defconfig: Enable some IPMI configs
  soc: ti: QMSS: Fix usage of irq_set_affinity_hint
  ARM: OMAP1: ams-delta: Fix impossible .irq < 0

Pull more arm64 updates from Catalin Marinas:

 - fix W+X page (mark RO) allocated by the arm64 kprobes code

 - Makefile fix for .i files in out of tree modules

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: kprobe: make page to RO mode when allocate it
  arm64: kdump: fix small typo
  arm64: makefile fix build of .i file in external module case

Pull dma-mapping fix from Christoph Hellwig:
 "Avoid compile warnings on non-default arm64 configs"

* tag 'dma-mapping-4.20-2' of git://git.infradead.org/users/hch/dma-mapping:
  arm64: fix warnings without CONFIG_IOMMU_DMA

Pull Kbuild updates from Masahiro Yamada:

 - clean-up leftovers in Kconfig files

 - remove stale oldnoconfig and silentoldconfig targets

 - remove unneeded cc-fullversion and cc-name variables

 - improve merge_config script to allow overriding option prefix

* tag 'kbuild-v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: remove cc-name variable
  kbuild: replace cc-name test with CONFIG_CC_IS_CLANG
  merge_config.sh: Allow to define config prefix
  kbuild: remove unused cc-fullversion variable
  kconfig: remove silentoldconfig target
  kconfig: remove oldnoconfig target
  powerpc: PCI_MSI needs PCI
  powerpc: remove CONFIG_MCA leftovers
  powerpc: remove CONFIG_PCI_QSPAN
  scsi: aha152x: rename the PCMCIA define

Pull cifs fixes and updates from Steve French:
 "Three small fixes (one Kerberos related, one for stable, and another
  fixes an oops in xfstest 377), two helpful debugging improvements,
  three patches for cifs directio and some minor cleanup"

* tag '4.20-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix signed/unsigned mismatch on aio_read patch
  cifs: don't dereference smb_file_target before null check
  CIFS: Add direct I/O functions to file_operations
  CIFS: Add support for direct I/O write
  CIFS: Add support for direct I/O read
  smb3: missing defines and structs for reparse point handling
  smb3: allow more detailed protocol info on open files for debugging
  smb3: on kerberos mount if server doesn't specify auth type use krb5
  smb3: add trace point for tree connection
  cifs: fix spelling mistake, EACCESS -> EACCES
  cifs: fix return value for cifs_listxattr

Pull 9p fix from Al Viro:
 "Regression fix for net/9p handling of iov_iter; broken by braino when
  switching to iov_iter_is_kvec() et.al., spotted and fixed by Marc"

* 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  iov_iter: Fix 9p virtio breakage

Pull more SCSI updates from James Bottomley:
 "This is a set of minor small (and safe changes) that didn't make the
  initial pull request plus some bug fixes"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: mvsas: Remove set but not used variable 'id'
  scsi: qla2xxx: Remove two arguments from qlafx00_error_entry()
  scsi: qla2xxx: Make sure that qlafx00_ioctl_iosb_entry() initializes 'res'
  scsi: qla2xxx: Remove a set-but-not-used variable
  scsi: qla2xxx: Make qla2x00_sysfs_write_nvram() easier to analyze
  scsi: qla2xxx: Declare local functions 'static'
  scsi: qla2xxx: Improve several kernel-doc headers
  scsi: qla2xxx: Modify fall-through annotations
  scsi: 3w-sas: 3w-9xxx: Use unsigned char for cdb
  scsi: mvsas: Use dma_pool_zalloc
  scsi: target: Don't request modules that aren't even built
  scsi: target: Set response length for REPORT TARGET PORT GROUPS

Merge more updates from Andrew Morton:

 - more ocfs2 work

 - various leftovers

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  memory_hotplug: cond_resched in __remove_pages
  bfs: add sanity check at bfs_fill_super()
  kernel/sysctl.c: remove duplicated include
  kernel/kexec_file.c: remove some duplicated includes
  mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask
  ocfs2: fix clusters leak in ocfs2_defrag_extent()
  ocfs2: dlmglue: clean up timestamp handling
  ocfs2: don't put and assigning null to bh allocated outside
  ocfs2: fix a misuse a of brelse after failing ocfs2_check_dir_entry
  ocfs2: don't use iocb when EIOCBQUEUED returns
  ocfs2: without quota support, avoid calling quota recovery
  ocfs2: remove ocfs2_is_o2cb_active()
  mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings
  include/linux/notifier.h: SRCU: fix ctags
  mm: handle no memcg case in memcg_kmem_charge() properly

We have received a bug report that unbinding a large pmem (>1TB) can
result in a soft lockup:

  NMI watchdog: BUG: soft lockup - CPU#9 stuck for 23s! [ndctl:4365]
  [...]
  Supported: Yes
  CPU: 9 PID: 4365 Comm: ndctl Not tainted 4.12.14-94.40-default #1 SLE12-SP4
  Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
  task: ffff9cce7d4410c0 task.stack: ffffbe9eb1bc4000
  RIP: 0010:__put_page+0x62/0x80
  Call Trace:
   devm_memremap_pages_release+0x152/0x260
   release_nodes+0x18d/0x1d0
   device_release_driver_internal+0x160/0x210
   unbind_store+0xb3/0xe0
   kernfs_fop_write+0x102/0x180
   __vfs_write+0x26/0x150
   vfs_write+0xad/0x1a0
   SyS_write+0x42/0x90
   do_syscall_64+0x74/0x150
   entry_SYSCALL_64_after_hwframe+0x3d/0xa2
  RIP: 0033:0x7fd13166b3d0

It has been reported on an older (4.12) kernel but the current upstream
code doesn't cond_resched in the hot remove code at all and the given
range to remove might be really large.  Fix the issue by calling
cond_resched once per memory section.

Link: http://lkml.kernel.org/r/20181031125840.23982-1-mhocko@kernel.orgSigned-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

syzbot is reporting too large memory allocation at bfs_fill_super() [1].
Since file system image is corrupted such that bfs_sb->s_start == 0,
bfs_fill_super() is trying to allocate 8MB of continuous memory. Fix
this by adding a sanity check on bfs_sb->s_start, __GFP_NOWARN and
printf().

[1] https://syzkaller.appspot.com/bug?id=16a87c236b951351374a84c8a32f40edbc034e96

Link: http://lkml.kernel.org/r/1525862104-3407-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jpSigned-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+71c6b5d68e91149fc8a4@syzkaller.appspotmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tigran Aivazian <aivazian.tigran@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>