For usb2 ports, the port test mode Test_J_State, Test_K_State,
Test_Packet, Test_SE0_NAK and Test_Force_En can be enabled
as described in usb2 spec.

USB2 test mode is a required hardware feature for system integrators
validating their hardware according to USB spec, regarding signal
strength and stuff. It is purely a hardware test feature.

Usually you need an oscilloscope and have to enable those test modes on
the hardware. This will send some specific test patterns on D+/D-. There
is no report available (in Linux itself) as it is purely externally
visible. Regular USB usage is not possible at that time.
Anyone (well access to e.g. /dev/bus/usb/001/001 provided) can use it by
sending appropriate USB_PORT_FEAT_TEST requests to the hub.

[Add better commit message by Alexander Stein  -Mathias]
Signed-off-by: Guoqing Zhang <guoqing.zhang@intel.com>
Cc: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Change the visability of xhci_start() so that it
can be used when enabling test mode.
Signed-off-by: Guoqing Zhang <guoqing.zhang@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Refactoring slot disable related code into a helper
function xhci_disable_slot() which can be used when
enabling test mode.
Signed-off-by: Guoqing Zhang <guoqing.zhang@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Refactoring port power on/off related code into
a helper function xhci_set_power_on() which can
be reused when enabling test mode.

[set port state to neutral before writing port power -Mathias]
Signed-off-by: Guoqing Zhang <guoqing.zhang@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

EINT(Event Interrupt) is a write-1-to-clear type of bit in xhci
status register. It should be cleared by writing a 1. Writing 0
to this bit has no effect.

Xhci driver tries to clear this bit by writing 0 to it. This is
not the right way to go. This patch corrects this by reading the
register first, then clearing all RO/RW1C/RsvZ bits and setting
the clearing bit, and writing back the new value at last.

Xhci spec requires that software that uses EINT shall clear it
prior to clearing any IP flags in section 5.4.2. This is the
reason why this patch is CC'ed stable as well.

[old way didn't cause any issues, skip stable, send to next -Mathias]

Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB host controllers can take a significant amount of time to suspend
and resume, adding several hundred miliseconds to the kernel resume
time. Since the XHCI controller has no outside dependencies (other than
clocks, which are suspended late/resumed early), allow it to suspend and
resume asynchronously.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Tested-by: Andrew Bresticker <abrestic@chromium.org>
Tested-by: Robert Foss <robert.foss@collabora.com>
Signed-off-by: Robert Foss <robert.foss@collabora.com>
Reviewed-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vhci_tx_urb() should be able to get the vhci_device from
its caller vhci_urb_enqueue(), instead of brutal-force
searching it.
Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Code refactoring to make the flow easier to follow.
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add missing continue in switch.

Addresses-Coverity-ID: 1248733
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a8c06e40 ("usb: separate out sysdev pointer from
usb_bus") converted to use hcd->self.sysdev for DMA
operations instead of hcd->self.controller but forgot to do
it for one instance.

This gets caught when DMA debugging is enabled since dma map
and unmap end up using different device pointers.

Fix it.

Fixes: a8c06e40 ("usb: separate out sysdev pointer from usb_bus")
Reported-by: Carlos Hernandez <ceh@ti.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We want the usb fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull dmaengine fixes from Vinod Koul:
 "A couple of minor fixes for 4.11:

   - array bound fix for __get_unmap_pool()

   - cyclic period splitting for bcm2835"

* tag 'dmaengine-fix-4.11-rc5' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: Fix array index out of bounds warning in __get_unmap_pool()
  dmaengine: bcm2835: Fix cyclic DMA period splitting

Pull x86 fixes from Thomas Gleixner:
 "This update provides:

   - prevent KASLR from randomizing EFI regions

   - restrict the usage of -maccumulate-outgoing-args and document when
     and why it is required.

   - make the Global Physical Address calculation for UV4 systems work
     correctly.

   - address a copy->paste->forgot-edit problem in the MCE exception
     table entries.

   - assign a name to AMD MCA bank 3, so the sysfs file registration
     works.

   - add a missing include in the boot code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Include missing header file
  x86/mce/AMD: Give a name to MCA bank 3 when accessed with legacy MSRs
  x86/build: Mostly disable '-maccumulate-outgoing-args'
  x86/mm/KASLR: Exclude EFI region from KASLR VA space randomization
  x86/mce: Fix copy/paste error in exception table entries
  x86/platform/uv: Fix calculation of Global Physical Address

Pull scheduler fixes from Thomas Gleixner:
 "This update provides:

   - make the scheduler clock switch to unstable mode smooth so the
     timestamps stay at microseconds granularity instead of switching to
     tick granularity.

   - unbreak perf test tsc by taking the new offset into account which
     was added in order to proveide better sched clock continuity

   - switching sched clock to unstable mode runs all clock related
     computations which affect the sched clock output itself from a work
     queue. In case of preemption sched clock uses half updated data and
     provides wrong timestamps. Keep the math in the protected context
     and delegate only the static key switch to workqueue context.

   - remove a duplicate header include"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/headers: Remove duplicate #include <linux/sched/debug.h> line
  sched/clock: Fix broken stable to unstable transfer
  sched/clock, x86/perf: Fix "perf test tsc"
  sched/clock: Fix clear_sched_clock_stable() preempt wobbly

Pull EFI fix from Thomas Gleixner:
 "Downgrade the missing ESRT header printk to warning level and remove a
  useless error printk which just generates noise for no value"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/esrt: Cleanup bad memory map log messages

Pull timer fixes from Thomas Gleixner:
 "Two small fixes for the new CLKEVT_OF infrastructure"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  vmlinux.lds: Add __clkevt_of_table to kernel
  clockevents: Fix syntax error in clkevt-of macro

Pull irq fixes from Thomas Gleixner:
 "Two small fixlets:

   - select a required Kconfig to make the MVEBU driver compile

   - add the missing MIPS local GIC interrupts which prevent drivers to
     probe successfully"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mips-gic: Fix Local compare interrupt
  irqchip/mvebu-odmi: Select GENERIC_MSI_IRQ_DOMAIN

Pull core fix from Thomas Gleixner:
 "Prevent leaking kernel memory via /proc/$pid/syscall when the queried
  task is not in a syscall"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lib/syscall: Clear return values when no stack

Pull parisc fixes from Helge Deller:
 "Al Viro reported that - in case of read faults - our copy_from_user()
  implementation may claim to have copied more bytes than it actually
  did. In order to fix this bug and because of the way how gcc optimizes
  register usage for inline assembly in C code, we had to replace our
  pa_memcpy() function with a pure assembler implementation.

  While fixing the memcpy bug we noticed some other issues with our
  get_user() and put_user() functions, e.g. nested faults may return
  wrong data. This is now fixed by a common fixup handler for
  get_user/put_user in the exception handler which additionally makes
  generated code smaller and faster.

  The third patch is a trivial one-line fix for a patch which went in
  during 4.11-rc and which avoids stalled CPU warnings after power
  shutdown (for parisc machines which can't plug power off themselves).

  Due to the rewrite of pa_memcpy() into assembly this patch got bigger
  than what I wanted to have sent at this stage.

  Those patches have been running in production during the last few days
  on our debian build servers without any further issues"

* 'parisc-4.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Avoid stalled CPU warnings after system shutdown
  parisc: Clean up fixup routines for get_user()/put_user()
  parisc: Fix access fault handling in pa_memcpy()

Pull SCSI fixes from James Bottomley:
 "Thirteen small fixes: The hopefully final effort to get the lpfc nvme
  kconfig problems sorted, there's one important sg fix (user can induce
  read after end of buffer) and one minor enhancement (adding an extra
  PCI ID to qedi). The rest are a set of minor fixes, which mostly occur
  as user visible in error legs or on specific devices"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ufs: remove the duplicated checking for supporting clkscaling
  scsi: lpfc: fix building without debugfs support
  scsi: lpfc: Fix PT2PT PRLI reject
  scsi: hpsa: fix volume offline state
  scsi: libsas: fix ata xfer length
  scsi: scsi_dh_alua: Warn if the first argument of alua_rtpg_queue() is NULL
  scsi: scsi_dh_alua: Ensure that alua_activate() calls the completion function
  scsi: scsi_dh_alua: Check scsi_device_get() return value
  scsi: sg: check length passed to SG_NEXT_CMD_LEN
  scsi: ufshcd-platform: remove the useless cast in ERR_PTR/IS_ERR
  scsi: qedi: Add PCI device-ID for QL41xxx adapters.
  scsi: aacraid: Fix potential null access
  scsi: qla2xxx: Fix crash in qla2xxx_eh_abort on bad ptr

Merge misc fixes from Andrew Morton:
 "11 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kasan: do not sanitize kexec purgatory
  drivers/rapidio/devices/tsi721.c: make module parameter variable name unique
  mm/hugetlb.c: don't call region_abort if region_chg fails
  kasan: report only the first error by default
  hugetlbfs: initialize shared policy as part of inode allocation
  mm: fix section name for .data..ro_after_init
  mm, hugetlb: use pte_present() instead of pmd_present() in follow_huge_pmd()
  mm: workingset: fix premature shadow node shrinking with cgroups
  mm: rmap: fix huge file mmap accounting in the memcg stats
  mm: move mm_percpu_wq initialization earlier
  mm: migrate: fix remove_migration_pte() for ksm pages

Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 4.11-rc5.

  The usual xhci fixes are here, as well as a fix for yet-another-bug-
  found-by-KASAN, those developers are doing great stuff here.

  And there's a phy build warning fix that showed up in 4.11-rc1.

  All of these have been in linux-next with no reported issues"

* tag 'usb-4.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: phy: isp1301: Fix build warning when CONFIG_OF is disabled
  xhci: Manually give back cancelled URB if we can't queue it for cancel
  xhci: Set URB actual length for stopped control transfers
  xhci: plat: Register shutdown for xhci_plat
  USB: fix linked-list corruption in rh_call_control()

Pull tty/serial fixes from Greg KH:
 "Here are some small fixes for some serial drivers and Kconfig help
  text for 4.11-rc5. Nothing major here at all, a few things resolving
  reported bugs in some random serial drivers.

  I don't think these made the last linux-next due to me getting to them
  yesterday, but I am not sure, they might have snuck in. The patches
  only affect drivers that the maintainers of sent me these patches for,
  so we should be safe here :)"

* tag 'tty-4.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: pl011: fix earlycon work-around for QDF2400 erratum 44
  serial: 8250_EXAR: fix duplicate Kconfig text and add missing help text
  tty/serial: atmel: fix TX path in atmel_console_write()
  tty/serial: atmel: fix race condition (TX+DMA)
  serial: mxs-auart: Fix baudrate calculation

Pull ACPI fixes from Rafael Wysocki:
 "These fix two issues related to IOAPIC hotplug, an overzealous build
  optimization that prevents the function graph tracer from working with
  the ACPI subsystem correctly and an RCU synchronization issue in the
  ACPI APEI code.

  Specifics:

   - drop the unconditional setting of the '-Os' gcc flag from the ACPI
     Makefile to make the function graph tracer work correctly with the
     ACPI subsystem (Josh Poimboeuf).

   - add missing synchronize_rcu() to ghes_remove() which removes an
     element from an RCU-protected list, but fails to synchronize it
     properly afterward (James Morse).

   - fix two problems related to IOAPIC hotplug, a local variable
     initialization in setup_res() and the creation of platform device
     objects for IO(x)APICs which are (a) unused and (b) leaked on
     hot-removal (Joerg Roedel)"

* tag 'acpi-4.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: Fix incompatibility with mcount-based function graph tracing
  ACPI / APEI: Add missing synchronize_rcu() on NOTIFY_SCI removal
  ACPI: Do not create a platform_device for IOAPIC/IOxAPIC
  ACPI: ioapic: Clear on-stack resource before using it

Pull power management fixes from Rafael Wysocki:
 "These fix a cpufreq core issue with the initialization of the cpufreq
  sysfs interface and a cpuidle powernv driver initialization issue.

  Specifics:

   - symbolic links from CPU directories to the corresponding cpufreq
     policy directories in sysfs are not created during initialization
     in some cases which confuses user space, so prevent that from
     happening (Rafael Wysocki).

   - the powernv cpuidle driver fails to pass a correct cpumaks to the
     cpuidle core in some cases which causes subsequent failures to
     occur, so fix it (Vaidyanathan Srinivasan)"

* tag 'pm-4.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpuidle: powernv: Pass correct drv->cpumask for registration
  cpufreq: Fix creation of symbolic links to policy directories

Pull i2c fixes from Wolfram Sang:
 "Two bugfixes from I2C, specifically the I2C mux section. Thanks to
  peda for collecting them"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: mux: pca954x: Add missing pca9546 definition to chip_desc
  Revert "i2c: mux: pca954x: Add ACPI support for pca954x"

Pull ARC fixes from Vineet Gupta:
 "Accumulated fixes for ARC which I've been been sitting on for a while:

   - reading clk from driver vs device tree [Vlad]

   - fix support for UIO in VDK platform [Alexey]

   - SLC busy bit reading workaround

   - build warning with kprobes header reorg"

* tag 'arc-4.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: fix build warnings with !CONFIG_KPROBES
  ARCv2: SLC: Make sure busy bit is set properly on SLC flushing
  ARC: vdk: Fix support of UIO
  ARCv2: make unimplemented vectors as no-ops rather than halt core
  ARC: get rate from clk driver instead of reading device tree
  ARC: [dts] add cpu nodes to ARCHS SMP device tree
  ARC: [dts] add input clocks for cpu nodes

Pull nfsd fixes from Bruce Fields:
 "The restriction of NFSv4 to TCP went overboard and also broke the
  backchannel; fix.

  Also some minor refinements to the nfsd version-setting interface that
  we'd like to get fixed before release"

* tag 'nfsd-4.11-1' of git://linux-nfs.org/~bfields/linux:
  svcrdma: set XPT_CONG_CTRL flag for bc xprt
  NFSD: fix nfsd_reset_versions for NFSv4.
  NFSD: fix nfsd_minorversion(.., NFSD_AVAIL)
  NFSD: further refinement of content of /proc/fs/nfsd/versions
  nfsd: map the ENOKEY to nfserr_perm for avoiding warning
  SUNRPC/backchanel: set XPT_CONG_CTRL flag for bc xprt

The work-around for the Qualcomm Datacenter Technologies QDF2400
erratum 44 sets the "qdf2400_e44_present" global variable if the
work-around is needed.  However, this check does not happen until after
earlycon is initialized, which means the work-around is not
used, and the console hangs as soon as it displays one character.

Fixes: d8a4995b ("tty: pl011: Work around QDF2400 E44 stuck BUSY bit")
Signed-off-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

write_used was introduced with commit 884b600f ("[PATCH] USB: fix acm
trouble with terminals") but never used since.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Adds a similar log message to USB_CDC_NOTIFY_SERIAL_STATE as it is
already done with USB_CDC_NOTIFY_NETWORK_CONNECTION.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB devices may have very limited endpoint packet sizes, so that
notifications can not be transferred within one single usb packet.
Reassembling of multiple packages may be necessary.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Notifications may only be 8 bytes long. Accessing the 9th and
10th byte of unimplemented/unknown notifications may be insecure.
Also check the length of known notifications before accessing anything
behind the 8th byte.
Signed-off-by: Tobias Herzog <t-herzog@gmx.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull btrfs fixes from Chris Mason:
 "We have three small fixes queued up in my for-linus-4.11 branch"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix an integer overflow check
  btrfs: Change qgroup_meta_rsv to 64bit
  Btrfs: bring back repair during read

Fixes this:

  kexec: Undefined symbol: __asan_load8_noabort
  kexec-bzImage64: Loading purgatory failed

Link: http://lkml.kernel.org/r/1489672155.4458.7.camel@gmx.deSigned-off-by: Mike Galbraith <efault@gmx.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kbuild test robot reported a non-static variable name collision between
a staging driver and a RapidIO driver, with a generic variable name of
'dbg_level'.

Both drivers should be changed so that they don't use this generic
public variable name.  This patch fixes the RapidIO driver but does not
change the user interface (name) for the module parameter.

  drivers/staging/built-in.o:(.bss+0x109d0): multiple definition of `dbg_level'
  drivers/rapidio/built-in.o:(.bss+0x16c): first defined here

Link: http://lkml.kernel.org/r/ab527fc5-aa3c-4b07-5d48-eef5de703192@infradead.orgSigned-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Changes to hugetlbfs reservation maps is a two step process.  The first
step is a call to region_chg to determine what needs to be changed, and
prepare that change.  This should be followed by a call to call to
region_add to commit the change, or region_abort to abort the change.

The error path in hugetlb_reserve_pages called region_abort after a
failed call to region_chg.  As a result, the adds_in_progress counter in
the reservation map is off by 1.  This is caught by a VM_BUG_ON in
resv_map_release when the reservation map is freed.

syzkaller fuzzer (when using an injected kmalloc failure) found this
bug, that resulted in the following:

 kernel BUG at mm/hugetlb.c:742!
 Call Trace:
  hugetlbfs_evict_inode+0x7b/0xa0 fs/hugetlbfs/inode.c:493
  evict+0x481/0x920 fs/inode.c:553
  iput_final fs/inode.c:1515 [inline]
  iput+0x62b/0xa20 fs/inode.c:1542
  hugetlb_file_setup+0x593/0x9f0 fs/hugetlbfs/inode.c:1306
  newseg+0x422/0xd30 ipc/shm.c:575
  ipcget_new ipc/util.c:285 [inline]
  ipcget+0x21e/0x580 ipc/util.c:639
  SYSC_shmget ipc/shm.c:673 [inline]
  SyS_shmget+0x158/0x230 ipc/shm.c:657
  entry_SYSCALL_64_fastpath+0x1f/0xc2
 RIP: resv_map_release+0x265/0x330 mm/hugetlb.c:742

Link: http://lkml.kernel.org/r/1490821682-23228-1-git-send-email-mike.kravetz@oracle.comSigned-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Disable kasan after the first report.  There are several reasons for
this:

 - Single bug quite often has multiple invalid memory accesses causing
   storm in the dmesg.

 - Write OOB access might corrupt metadata so the next report will print
   bogus alloc/free stacktraces.

 - Reports after the first easily could be not bugs by itself but just
   side effects of the first one.

Given that multiple reports usually only do harm, it makes sense to
disable kasan after the first one.  If user wants to see all the
reports, the boot-time parameter kasan_multi_shot must be used.

[aryabinin@virtuozzo.com: wrote changelog and doc, added missing include]
Link: http://lkml.kernel.org/r/20170323154416.30257-1-aryabinin@virtuozzo.comSigned-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Any time after inode allocation, destroy_inode can be called.  The
hugetlbfs inode contains a shared_policy structure, and
mpol_free_shared_policy is unconditionally called as part of
hugetlbfs_destroy_inode.  Initialize the policy as part of inode
allocation so that any quick (error path) calls to destroy_inode will be
handed an initialized policy.

syzkaller fuzzer found this bug, that resulted in the following:

    BUG: KASAN: user-memory-access in atomic_inc
    include/asm-generic/atomic-instrumented.h:87 [inline] at addr
    000000131730bd7a
    BUG: KASAN: user-memory-access in __lock_acquire+0x21a/0x3a80
    kernel/locking/lockdep.c:3239 at addr 000000131730bd7a
    Write of size 4 by task syz-executor6/14086
    CPU: 3 PID: 14086 Comm: syz-executor6 Not tainted 4.11.0-rc3+ #364
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Call Trace:
     atomic_inc include/asm-generic/atomic-instrumented.h:87 [inline]
     __lock_acquire+0x21a/0x3a80 kernel/locking/lockdep.c:3239
     lock_acquire+0x1ee/0x590 kernel/locking/lockdep.c:3762
     __raw_write_lock include/linux/rwlock_api_smp.h:210 [inline]
     _raw_write_lock+0x33/0x50 kernel/locking/spinlock.c:295
     mpol_free_shared_policy+0x43/0xb0 mm/mempolicy.c:2536
     hugetlbfs_destroy_inode+0xca/0x120 fs/hugetlbfs/inode.c:952
     alloc_inode+0x10d/0x180 fs/inode.c:216
     new_inode_pseudo+0x69/0x190 fs/inode.c:889
     new_inode+0x1c/0x40 fs/inode.c:918
     hugetlbfs_get_inode+0x40/0x420 fs/hugetlbfs/inode.c:734
     hugetlb_file_setup+0x329/0x9f0 fs/hugetlbfs/inode.c:1282
     newseg+0x422/0xd30 ipc/shm.c:575
     ipcget_new ipc/util.c:285 [inline]
     ipcget+0x21e/0x580 ipc/util.c:639
     SYSC_shmget ipc/shm.c:673 [inline]
     SyS_shmget+0x158/0x230 ipc/shm.c:657
     entry_SYSCALL_64_fastpath+0x1f/0xc2

Analysis provided by Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

Link: http://lkml.kernel.org/r/1490477850-7944-1-git-send-email-mike.kravetz@oracle.comSigned-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>