Although we don't expect to take alignment faults on access to normal
memory, misbehaving (i.e. buggy) user code can pass MMIO pointers into
system calls, leading to things like get_user accessing device memory.

Rather than OOPS the kernel, allow any exception fixups to run and
return something like -EFAULT back to userspace. This makes the
behaviour more consistent with userspace, even though applications with
access to device mappings can easily cause other issues if they try
hard enough.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NEun Taik Lee <eun.taik.lee@samsung.com>
[will: dropped __kprobes annotation and rewrote commit mesage]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

For the same reason as commit 19514fc6 ("arm, kbuild: make "make
install" not depend on vmlinux"), the install targets should never
trigger the rebuild of the kernel.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This patch ensures that devices, which got registered before arch_initcall
will be handled correctly by IOMMU-based DMA-mapping code.

Cc: <stable@vger.kernel.org>
Fixes: 13b8629f ("arm64: Add IOMMU dma_ops")
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Changes introduced in the upstream version of libfdt pulled in by commit
91feabc2 ("scripts/dtc: Update to upstream commit b06e55c88b9b") use
the strnlen() function, which isn't currently available to the EFI name-
space. Add it to the EFI namespace to avoid a linker error.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Rob Herring <robh@kernel.org>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

ECB modes don't use an initialization vector. The kernel
/proc/crypto interface doesn't reflect this properly.
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Switching between stacks is only valid if we are tracing ourselves while on the
irq_stack, so it is only valid when in current and non-preemptible context,
otherwise is is just zeroed off.

Fixes: 132cd887 ("arm64: Modify stack trace and dump for use with irq_stack")
Acked-by: NJames Morse <james.morse@arm.com>
Tested-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NYang Shi <yang.shi@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

force_sig_info can sleep under an -rt kernel, so attempting to send a
breakpoint SIGTRAP with interrupts disabled yields the following BUG:

  BUG: sleeping function called from invalid context at
  /kernel-source/kernel/locking/rtmutex.c:917
  in_atomic(): 0, irqs_disabled(): 128, pid: 551, name: test.sh
  CPU: 5 PID: 551 Comm: test.sh Not tainted 4.1.13-rt13 #7
  Hardware name: Freescale Layerscape 2085a RDB Board (DT)
  Call trace:
	 dump_backtrace+0x0/0x128
	 show_stack+0x24/0x30
	 dump_stack+0x80/0xa0
	 ___might_sleep+0x128/0x1a0
	 rt_spin_lock+0x2c/0x40
	 force_sig_info+0xcc/0x210
	 brk_handler.part.2+0x6c/0x80
	 brk_handler+0xd8/0xe8
	 do_debug_exception+0x58/0xb8

This patch fixes the problem by ensuring that interrupts are enabled
prior to sending the SIGTRAP if they were already enabled in the user
context.
Reported-by: NYang Shi <yang.shi@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When boot arm64 kernel with KASAN enabled, the below error is reported by
kasan:

BUG: KASAN: out-of-bounds in unwind_frame+0xec/0x260 at addr ffffffc064d57ba0
Read of size 8 by task pidof/499
page:ffffffbdc39355c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
page dumped because: kasan: bad access detected
CPU: 2 PID: 499 Comm: pidof Not tainted 4.5.0-rc1 #119
Hardware name: Freescale Layerscape 2085a RDB Board (DT)
Call trace:
[<ffffffc00008d078>] dump_backtrace+0x0/0x290
[<ffffffc00008d32c>] show_stack+0x24/0x30
[<ffffffc0006a981c>] dump_stack+0x8c/0xd8
[<ffffffc0002e4400>] kasan_report_error+0x558/0x588
[<ffffffc0002e4958>] kasan_report+0x60/0x70
[<ffffffc0002e3188>] __asan_load8+0x60/0x78
[<ffffffc00008c92c>] unwind_frame+0xec/0x260
[<ffffffc000087e60>] get_wchan+0x110/0x160
[<ffffffc0003b647c>] do_task_stat+0xb44/0xb68
[<ffffffc0003b7730>] proc_tgid_stat+0x40/0x50
[<ffffffc0003ac840>] proc_single_show+0x88/0xd8
[<ffffffc000345be8>] seq_read+0x370/0x770
[<ffffffc00030aba0>] __vfs_read+0xc8/0x1d8
[<ffffffc00030c0ec>] vfs_read+0x94/0x168
[<ffffffc00030d458>] SyS_read+0xb8/0x128
[<ffffffc000086530>] el0_svc_naked+0x24/0x28
Memory state around the buggy address:
 ffffffc064d57a80: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f4 f4
 ffffffc064d57b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffc064d57b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                  ^
 ffffffc064d57c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffc064d57c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Since the shadow byte pointed by the report is 0, so it may mean it is just hit
oob in non-current task. So, disable the instrumentation to silence these
warnings.
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NYang Shi <yang.shi@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Pull ARM SoC fixes from Olof Johansson:
 "The first real batch of fixes for this release cycle, so there are a
  few more than usual.

  Most of these are fixes and tweaks to board support (DT bugfixes,
  etc).  I've also picked up a couple of small cleanups that seemed
  innocent enough that there was little reason to wait (const/
  __initconst and Kconfig deps).

  Quite a bit of the changes on OMAP were due to fixes to no longer
  write to rodata from assembly when ARM_KERNMEM_PERMS was enabled, but
  there were also other fixes.

  Kirkwood had a bunch of gpio fixes for some boards.  OMAP had RTC
  fixes on OMAP5, and Nomadik had changes to MMC parameters in DT.

  All in all, mostly the usual mix of various fixes"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (46 commits)
  ARM: multi_v7_defconfig: enable DW_WATCHDOG
  ARM: nomadik: fix up SD/MMC DT settings
  ARM64: tegra: Add chosen node for tegra132 norrin
  ARM: realview: use "depends on" instead of "if" after prompt
  ARM: tango: use "depends on" instead of "if" after prompt
  ARM: tango: use const and __initconst for smp_operations
  ARM: realview: use const and __initconst for smp_operations
  bus: uniphier-system-bus: revive tristate prompt
  arm64: dts: Add missing DMA Abort interrupt to Juno
  bus: vexpress-config: Add missing of_node_put
  ARM: dts: am57xx: sbc-am57x: correct Eth PHY settings
  ARM: dts: am57xx: cl-som-am57x: fix CPSW EMAC pinmux
  ARM: dts: am57xx: sbc-am57x: fix UART3 pinmux
  ARM: dts: am57xx: cl-som-am57x: update SPI Flash frequency
  ARM: dts: am57xx: cl-som-am57x: set HOST mode for USB2
  ARM: dts: am57xx: sbc-am57x: fix SB-SOM EEPROM I2C address
  ARM: dts: LogicPD Torpedo: Revert Duplicative Entries
  ARM: dts: am437x: pixcir_tangoc: use correct flags for irq types
  ARM: dts: am4372: fix irq type for arm twd and global timer
  ARM: dts: at91: sama5d4 xplained: fix phy0 IRQ type
  ...

Pull mailbox fixes from Jassi Brar:

 - fix getting element from the pcc-channels array by simply indexing
   into it

 - prevent building mailbox-test driver for archs that don't have IOMEM

* 'mailbox-devel' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: Fix dependencies for !HAS_IOMEM archs
  mailbox: pcc: fix channel calculation in get_pcc_channel()

Pull USB fixes from Greg KH:
 "Here are some USB fixes for 4.5-rc3.

  The usual, xhci fixes for reported issues, combined with some small
  gadget driver fixes, and a MAINTAINERS file update.  All have been in
  linux-next with no reported issues"

* tag 'usb-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  xhci: harden xhci_find_next_ext_cap against device removal
  xhci: Fix list corruption in urb dequeue at host removal
  usb: host: xhci-plat: fix NULL pointer in probe for device tree case
  usb: xhci-mtk: fix AHB bus hang up caused by roothubs polling
  usb: xhci-mtk: fix bpkts value of LS/HS periodic eps not behind TT
  usb: xhci: apply XHCI_PME_STUCK_QUIRK to Intel Broxton-M platforms
  usb: xhci: set SSIC port unused only if xhci_suspend succeeds
  usb: xhci: add a quirk bit for ssic port unused
  usb: xhci: handle both SSIC ports in PME stuck quirk
  usb: dwc3: gadget: set the OTG flag in dwc3 gadget driver.
  Revert "xhci: don't finish a TD if we get a short-transfer event mid TD"
  MAINTAINERS: fix my email address
  usb: dwc2: Fix probe problem on bcm2835
  Revert "usb: dwc2: Move reset into dwc2_get_hwparams()"
  usb: musb: ux500: Fix NULL pointer dereference at system PM
  usb: phy: mxs: declare variable with initialized value
  usb: phy: msm: fix error handling in probe.

Pull staging and IIO driver fixes from Greg KH:
 "Here are some IIO and staging driver fixes for 4.5-rc3.

  All of them, except one, are for IIO drivers, and one is for a speakup
  driver fix caused by some earlier patches, to resolve a reported build
  failure"

* tag 'staging-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  Staging: speakup: Fix allyesconfig build on mn10300
  iio: dht11: Use boottime
  iio: ade7753: avoid uninitialized data
  iio: pressure: mpl115: fix temperature offset sign
  iio: imu: Fix dependencies for !HAS_IOMEM archs
  staging: iio: Fix dependencies for !HAS_IOMEM archs
  iio: adc: Fix dependencies for !HAS_IOMEM archs
  iio: inkern: fix a NULL dereference on error
  iio:adc:ti_am335x_adc Fix buffered mode by identifying as software buffer.
  iio: light: acpi-als: Report data as processed
  iio: dac: mcp4725: set iio name property in sysfs
  iio: add HAS_IOMEM dependency to VF610_ADC
  iio: add IIO_TRIGGER dependency to STK8BA50
  iio: proximity: lidar: correct return value
  iio-light: Use a signed return type for ltr501_match_samp_freq()

Merge fixes from Andrew Morton:
 "22 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits)
  epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUT
  radix-tree: fix oops after radix_tree_iter_retry
  MAINTAINERS: trim the file triggers for ABI/API
  dax: dirty inode only if required
  thp: make deferred_split_scan() work again
  mm: replace vma_lock_anon_vma with anon_vma_lock_read/write
  ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup
  um: asm/page.h: remove the pte_high member from struct pte_t
  mm, hugetlb: don't require CMA for runtime gigantic pages
  mm/hugetlb: fix gigantic page initialization/allocation
  mm: downgrade VM_BUG in isolate_lru_page() to warning
  mempolicy: do not try to queue pages from !vma_migratable()
  mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress
  vmstat: make vmstat_update deferrable
  mm, vmstat: make quiet_vmstat lighter
  mm/Kconfig: correct description of DEFERRED_STRUCT_PAGE_INIT
  memblock: don't mark memblock_phys_mem_size() as __init
  dump_stack: avoid potential deadlocks
  mm: validate_mm browse_rb SMP race condition
  m32r: fix build failure due to SMP and MMU
  ...

Pull Ceph fixes from Sage Weil:
 "We have a few wire protocol compatibility fixes, ports of a few recent
  CRUSH mapping changes, and a couple error path fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  libceph: MOSDOpReply v7 encoding
  libceph: advertise support for TUNABLES5
  crush: decode and initialize chooseleaf_stable
  crush: add chooseleaf_stable tunable
  crush: ensure take bucket value is valid
  crush: ensure bucket id is valid before indexing buckets array
  ceph: fix snap context leak in error path
  ceph: checking for IS_ERR instead of NULL

Pull drm fixes from Dave Airlie:
 "Fixes all over the place:

   - amdkfd: two static checker fixes
   - mst: a bunch of static checker and spec/hw interaction fixes
   - amdgpu: fix Iceland hw properly, and some fiji bugs, along with
     some write-combining fixes.
   - exynos: some regression fixes
   - adv7511: fix some EDID reading issues"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (38 commits)
  drm/dp/mst: deallocate payload on port destruction
  drm/dp/mst: Reverse order of MST enable and clearing VC payload table.
  drm/dp/mst: move GUID storage from mgr, port to only mst branch
  drm/dp/mst: change MST detection scheme
  drm/dp/mst: Calculate MST PBN with 31.32 fixed point
  drm: Add drm_fixp_from_fraction and drm_fixp2int_ceil
  drm/mst: Add range check for max_payloads during init
  drm/mst: Don't ignore the MST PBN self-test result
  drm: fix missing reference counting decrease
  drm/amdgpu: disable uvd and vce clockgating on Fiji
  drm/amdgpu: remove exp hardware support from iceland
  drm/amdgpu: load MEC ucode manually on iceland
  drm/amdgpu: don't load MEC2 on topaz
  drm/amdgpu: drop topaz support from gmc8 module
  drm/amdgpu: pull topaz gmc bits into gmc_v7
  drm/amdgpu: The VI specific EXE bit should only apply to GMC v8.0 above
  drm/amdgpu: iceland use CI based MC IP
  drm/amdgpu: move gmc7 support out of CIK dependency
  drm/amdgpu/gfx7: enable cp inst/reg error interrupts
  drm/amdgpu/gfx8: enable cp inst/reg error interrupts
  ...

Pull power management and ACPI fixes from Rafael Wysocki:
 "These are: a fix for a recently introduced false-positive warnings
  about PM domain pointers being changed inappropriately (harmless but
  annoying), an MCH size workaround quirk for one more platform, a
  compiler warning fix (generic power domains framework), an ACPI LPSS
  (Intel SoCs) driver fixup and a cleanup of the ACPI CPPC core code.

  Specifics:

   - PM core fix to avoid false-positive warnings generated when the
     pm_domain field is cleared for a device that appears to be bound to
     a driver (Rafael Wysocki).

   - New MCH size workaround quirk for Intel Haswell-ULT (Josh Boyer).

   - Fix for an "unused function" compiler warning in the generic power
     domains framework (Ulf Hansson).

   - Fixup for the ACPI driver for Intel SoCs (acpi-lpss) to set the PM
     domain pointer of a device properly in one place that was
     overlooked by a recent PM core update (Andy Shevchenko).

   - Removal of a redundant function declaration in the ACPI CPPC core
     code (Timur Tabi)"

* tag 'pm+acpi-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: Avoid false-positive warnings in dev_pm_domain_set()
  PM / Domains: Silence compiler warning for an unused function
  ACPI / CPPC: remove redundant mbox_send_message() declaration
  ACPI / LPSS: set PM domain via helper setter
  PNP: Add Haswell-ULT to Intel MCH size workaround

In the current implementation of the EPOLLEXCLUSIVE flag (added for
4.5-rc1), if epoll waiters create different POLL* sets and register them
as exclusive against the same target fd, the current implementation will
stop waking any further waiters once it finds the first idle waiter.
This means that waiters could miss wakeups in certain cases.

For example, when we wake up a pipe for reading we do:
wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); So if
one epoll set or epfd is added to pipe p with POLLIN and a second set
epfd2 is added to pipe p with POLLRDNORM, only epfd may receive the
wakeup since the current implementation will stop after it finds any
intersection of events with a waiter that is blocked in epoll_wait().

We could potentially address this by requiring all epoll waiters that
are added to p be required to pass the same set of POLL* events.  IE the
first EPOLL_CTL_ADD that passes EPOLLEXCLUSIVE establishes the set POLL*
flags to be used by any other epfds that are added as EPOLLEXCLUSIVE.
However, I think it might be somewhat confusing interface as we would
have to reference count the number of users for that set, and so
userspace would have to keep track of that count, or we would need a
more involved interface.  It also adds some shared state that we'd have
store somewhere.  I don't think anybody will want to bloat
__wait_queue_head for this.

I think what we could do instead, is to simply restrict EPOLLEXCLUSIVE
such that it can only be specified with EPOLLIN and/or EPOLLOUT.  So
that way if the wakeup includes 'POLLIN' and not 'POLLOUT', we can stop
once we hit the first idle waiter that specifies the EPOLLIN bit, since
any remaining waiters that only have 'POLLOUT' set wouldn't need to be
woken.  Likewise, we can do the same thing if 'POLLOUT' is in the wakeup
bit set and not 'POLLIN'.  If both 'POLLOUT' and 'POLLIN' are set in the
wake bit set (there is at least one example of this I saw in fs/pipe.c),
then we just wake the entire exclusive list.  Having both 'POLLOUT' and
'POLLIN' both set should not be on any performance critical path, so I
think that's ok (in fs/pipe.c its in pipe_release()).  We also continue
to include EPOLLERR and EPOLLHUP by default in any exclusive set.  Thus,
the user can specify EPOLLERR and/or EPOLLHUP but is not required to do
so.

Since epoll waiters may be interested in other events as well besides
EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP, these can still be added by
doing a 'dup' call on the target fd and adding that as one normally
would with EPOLL_CTL_ADD.  Since I think that the POLLIN and POLLOUT
events are what we are interest in balancing, I think that the 'dup'
thing could perhaps be added to only one of the waiter threads.
However, I think that EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP should be
sufficient for the majority of use-cases.

Since EPOLLEXCLUSIVE is intended to be used with a target fd shared
among multiple epfds, where between 1 and n of the epfds may receive an
event, it does not satisfy the semantics of EPOLLONESHOT where only 1
epfd would get an event.  Thus, it is not allowed to be specified in
conjunction with EPOLLEXCLUSIVE.

EPOLL_CTL_MOD is also not allowed if the fd was previously added as
EPOLLEXCLUSIVE.  It seems with the limited number of flags to not be as
interesting, but this could be relaxed at some further point.
Signed-off-by: NJason Baron <jbaron@akamai.com>
Tested-by: NMadars Vitolins <m@silodev.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Eric Wong <normalperson@yhbt.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Helper radix_tree_iter_retry() resets next_index to the current index.
In following radix_tree_next_slot current chunk size becomes zero.  This
isn't checked and it tries to dereference null pointer in slot.

Tagged iterator is fine because retry happens only at slot 0 where tag
bitmask in iter->tags is filled with single bit.

Fixes: 46437f9a ("radix-tree: fix race in gang lookup")
Signed-off-by: NKonstantin Khlebnikov <koct9i@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Jeremiah Mahler <jmmahler@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit ea8f8fc8 ("MAINTAINERS: add linux-api for review of API/ABI
changes") added file triggers for various paths that likely indicated
API/ABI changes.  However, catching all changes in Documentation/ABI/
and include/uapi/ produces a large volume of mail to linux-api, rather
than only API/ABI changes.  Drop those two entries, but leave
include/linux/syscalls.h and kernel/sys_ni.c to catch syscall-related
changes.

[josh@joshtriplett.org: redid changelog]
Signed-off-by: NMichael Kerrisk <mtk.man-pages@gmail.com>
Acked-by: NShuah khan <shuahkh@osg.samsung.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We need to iterate over split_queue, not local empty list to get
anything split from the shrinker.

Fixes: e3ae1953 ("thp: limit number of object to scan on deferred_split_scan()")
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sequence vma_lock_anon_vma() - vma_unlock_anon_vma() isn't safe if
anon_vma appeared between lock and unlock.  We have to check anon_vma
first or call anon_vma_prepare() to be sure that it's here.  There are
only few users of these legacy helpers.  Let's get rid of them.

This patch fixes anon_vma lock imbalance in validate_mm().  Write lock
isn't required here, read lock is enough.

And reorders expand_downwards/expand_upwards: security_mmap_addr() and
wrapping-around check don't have to be under anon vma lock.

Link: https://lkml.kernel.org/r/CACT4Y+Y908EjM2z=706dv4rV6dWtxTLK9nFg9_7DhRMLppBo2g@mail.gmail.comSigned-off-by: NKonstantin Khlebnikov <koct9i@gmail.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When recovery master down, dlm_do_local_recovery_cleanup() only remove
the $RECOVERY lock owned by dead node, but do not clear the refmap bit.
Which will make umount thread falling in dead loop migrating $RECOVERY
to the dead node.
Signed-off-by: Nxuejiufei <xuejiufei@huawei.com>
Reviewed-by: NJoseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 16da3068 ("um: kill pfn_t") introduced a compile warning for
defconfig (SUBARCH=i386):

  arch/um/kernel/skas/mmu.c:38:206:
      warning: right shift count >= width of type [-Wshift-count-overflow]

Aforementioned patch changes the definition of the phys_to_pfn() macro
from

  ((pfn_t) ((p) >> PAGE_SHIFT))

to

  ((p) >> PAGE_SHIFT)

This effectively changes the phys_to_pfn() expansion's type from
unsigned long long to unsigned long.

Through the callchain init_stub_pte() => mk_pte(), the expansion of
phys_to_pfn() is (indirectly) fed into the 'phys' argument of the
pte_set_val(pte, phys, prot) macro, eventually leading to

  (pte).pte_high = (phys) >> 32;

This results in the warning from above.

Since UML only deals with 32 bit addresses, the upper 32 bits from
'phys' used to be always zero anyway.  Also, all page protection flags
defined by UML don't use any bits beyond bit 9.  Since the contents of a
PTE are defined within architecture scope only, the ->pte_high member
can be safely removed.

Remove the ->pte_high member from struct pte_t.
Rename ->pte_low to ->pte.
Adapt the pte helper macros in arch/um/include/asm/page.h.

Noteworthy is the pte_copy() macro where a smp_wmb() gets dropped.  This
write barrier doesn't seem to be paired with any read barrier though and
thus, was useless anyway.

Fixes: 16da3068 ("um: kill pfn_t")
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 944d9fec ("hugetlb: add support for gigantic page allocation
at runtime") has added the runtime gigantic page allocation via
alloc_contig_range(), making this support available only when CONFIG_CMA
is enabled.  Because it doesn't depend on MIGRATE_CMA pageblocks and the
associated infrastructure, it is possible with few simple adjustments to
require only CONFIG_MEMORY_ISOLATION instead of full CONFIG_CMA.

After this patch, alloc_contig_range() and related functions are
available and used for gigantic pages with just CONFIG_MEMORY_ISOLATION
enabled.  Note CONFIG_CMA selects CONFIG_MEMORY_ISOLATION.  This allows
supporting runtime gigantic pages without the CMA-specific checks in
page allocator fastpaths.
Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Attempting to preallocate 1G gigantic huge pages at boot time with
"hugepagesz=1G hugepages=1" on the kernel command line will prevent
booting with the following:

  kernel BUG at mm/hugetlb.c:1218!

When mapcount accounting was reworked, the setting of
compound_mapcount_ptr in prep_compound_gigantic_page was overlooked.  As
a result, the validation of mapcount in free_huge_page fails.

The "BUG_ON" checks in free_huge_page were also changed to
"VM_BUG_ON_PAGE" to assist with debugging.

Fixes: 53f9263b ("mm: rework mapcount accounting to enable 4k mapping of THPs")
Signed-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Tested-by: NVlastimil Babka <vbabka@suse.cz>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Calling isolate_lru_page() is wrong and shouldn't happen, but it not
nessesary fatal: the page just will not be isolated if it's not on LRU.

Let's downgrade the VM_BUG_ON_PAGE() to WARN_RATELIMIT().
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Maybe I miss some point, but I don't see a reason why we try to queue
pages from non migratable VMAs.

This testcase steps on VM_BUG_ON_PAGE() in isolate_lru_page():

    #include <fcntl.h>
    #include <unistd.h>
    #include <stdio.h>
    #include <sys/mman.h>
    #include <numaif.h>

    #define SIZE 0x2000

    int foo;

    int main()
    {
        int fd;
        char *p;
        unsigned long mask = 2;

        fd = open("/dev/sg0", O_RDWR);
        p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
        /* Faultin pages */
        foo = p[0] + p[0x1000];
        mbind(p, SIZE, MPOL_BIND, &mask, 4, MPOL_MF_MOVE | MPOL_MF_STRICT);
        return 0;
    }

The only case when we can queue pages from such VMA is MPOL_MF_STRICT
plus MPOL_MF_MOVE or MPOL_MF_MOVE_ALL for VMA which has pages on LRU,
but gfp mask is not sutable for migaration (see mapping_gfp_mask() check
in vma_migratable()).  That's looks like a bug to me.

Let's filter out non-migratable vma at start of queue_pages_test_walk()
and go to queue_pages_pte_range() only if MPOL_MF_MOVE or
MPOL_MF_MOVE_ALL flag is set.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Jan Stancek has reported that system occasionally hanging after "oom01"
testcase from LTP triggers OOM.  Guessing from a result that there is a
kworker thread doing memory allocation and the values between "Node 0
Normal free:" and "Node 0 Normal:" differs when hanging, vmstat is not
up-to-date for some reason.

According to commit 373ccbe5 ("mm, vmstat: allow WQ concurrency to
discover memory reclaim doesn't make any progress"), it meant to force
the kworker thread to take a short sleep, but it by error used
schedule_timeout(1).  We missed that schedule_timeout() in state
TASK_RUNNING doesn't do anything.

Fix it by using schedule_timeout_uninterruptible(1) which forces the
kworker thread to take a short sleep in order to make sure that vmstat
is up-to-date.

Fixes: 373ccbe5 ("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make any progress")
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: NJan Stancek <jstancek@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Cristopher Lameter <clameter@sgi.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Arkadiusz Miskiewicz <arekm@maven.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 0eb77e98 ("vmstat: make vmstat_updater deferrable again and
shut down on idle") made vmstat_shepherd deferrable.  vmstat_update
itself is still useing standard timer which might interrupt idle task.
This is possible because "mm, vmstat: make quiet_vmstat lighter" removed
cancel_delayed_work from the quiet_vmstat.

Change vmstat_work to use DEFERRABLE_WORK to prevent from pointless
wakeups from the idle context.
Acked-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mike has reported a considerable overhead of refresh_cpu_vm_stats from
the idle entry during pipe test:

    12.89%  [kernel]       [k] refresh_cpu_vm_stats.isra.12
     4.75%  [kernel]       [k] __schedule
     4.70%  [kernel]       [k] mutex_unlock
     3.14%  [kernel]       [k] __switch_to

This is caused by commit 0eb77e98 ("vmstat: make vmstat_updater
deferrable again and shut down on idle") which has placed quiet_vmstat
into cpu_idle_loop.  The main reason here seems to be that the idle
entry has to get over all zones and perform atomic operations for each
vmstat entry even though there might be no per cpu diffs.  This is a
pointless overhead for _each_ idle entry.

Make sure that quiet_vmstat is as light as possible.

First of all it doesn't make any sense to do any local sync if the
current cpu is already set in oncpu_stat_off because vmstat_update puts
itself there only if there is nothing to do.

Then we can check need_update which should be a cheap way to check for
potential per-cpu diffs and only then do refresh_cpu_vm_stats.

The original patch also did cancel_delayed_work which we are not doing
here.  There are two reasons for that.  Firstly cancel_delayed_work from
idle context will blow up on RT kernels (reported by Mike):

  CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.5.0-rt3 #7
  Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013
  Call Trace:
    dump_stack+0x49/0x67
    ___might_sleep+0xf5/0x180
    rt_spin_lock+0x20/0x50
    try_to_grab_pending+0x69/0x240
    cancel_delayed_work+0x26/0xe0
    quiet_vmstat+0x75/0xa0
    cpu_idle_loop+0x38/0x3e0
    cpu_startup_entry+0x13/0x20
    start_secondary+0x114/0x140

And secondly, even on !RT kernels it might add some non trivial overhead
which is not necessary.  Even if the vmstat worker wakes up and preempts
idle then it will be most likely a single shot noop because the stats
were already synced and so it would end up on the oncpu_stat_off anyway.
We just need to teach both vmstat_shepherd and vmstat_update to stop
scheduling the worker if there is nothing to do.

[mgalbraith@suse.de: cancel pending work of the cpu_stat_off CPU]
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NMike Galbraith <umgwanakikbuti@gmail.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NMike Galbraith <mgalbraith@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The description mentions kswapd threads, while the deferred struct page
initialization is actually done by one-off "pgdatinitX" threads.

Fix the description so that potentially users are not confused about
pgdatinit threads using CPU after boot instead of kswapd.
Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

At the moment memblock_phys_mem_size() is marked as __init, and so is
discarded after boot.  This is different from most of the memblock
functions which are marked __init_memblock, and are only discarded after
boot if memory hotplug is not configured.

To allow for upcoming code which will need memblock_phys_mem_size() in
the hotplug path, change it from __init to __init_memblock.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some servers experienced fatal deadlocks because of a combination of
bugs, leading to multiple cpus calling dump_stack().

The checksumming bug was fixed in commit 34ae6a1a ("ipv6: update
skb->csum when CE mark is propagated").

The second problem is a faulty locking in dump_stack()

CPU1 runs in process context and calls dump_stack(), grabs dump_lock.

   CPU2 receives a TCP packet under softirq, grabs socket spinlock, and
   call dump_stack() from netdev_rx_csum_fault().

   dump_stack() spins on atomic_cmpxchg(&dump_lock, -1, 2), since
   dump_lock is owned by CPU1

While dumping its stack, CPU1 is interrupted by a softirq, and happens
to process a packet for the TCP socket locked by CPU2.

CPU1 spins forever in spin_lock() : deadlock

Stack trace on CPU1 looked like :

    NMI backtrace for cpu 1
    RIP: _raw_spin_lock+0x25/0x30
    ...
    Call Trace:
      <IRQ>
      tcp_v6_rcv+0x243/0x620
      ip6_input_finish+0x11f/0x330
      ip6_input+0x38/0x40
      ip6_rcv_finish+0x3c/0x90
      ipv6_rcv+0x2a9/0x500
      process_backlog+0x461/0xaa0
      net_rx_action+0x147/0x430
      __do_softirq+0x167/0x2d0
      call_softirq+0x1c/0x30
      do_softirq+0x3f/0x80
      irq_exit+0x6e/0xc0
      smp_call_function_single_interrupt+0x35/0x40
      call_function_single_interrupt+0x6a/0x70
      <EOI>
      printk+0x4d/0x4f
      printk_address+0x31/0x33
      print_trace_address+0x33/0x3c
      print_context_stack+0x7f/0x119
      dump_trace+0x26b/0x28e
      show_trace_log_lvl+0x4f/0x5c
      show_stack_log_lvl+0x104/0x113
      show_stack+0x42/0x44
      dump_stack+0x46/0x58
      netdev_rx_csum_fault+0x38/0x3c
      __skb_checksum_complete_head+0x6e/0x80
      __skb_checksum_complete+0x11/0x20
      tcp_rcv_established+0x2bd5/0x2fd0
      tcp_v6_do_rcv+0x13c/0x620
      sk_backlog_rcv+0x15/0x30
      release_sock+0xd2/0x150
      tcp_recvmsg+0x1c1/0xfc0
      inet_recvmsg+0x7d/0x90
      sock_recvmsg+0xaf/0xe0
      ___sys_recvmsg+0x111/0x3b0
      SyS_recvmsg+0x5c/0xb0
      system_call_fastpath+0x16/0x1b

Fixes: b58d9774 ("dump_stack: serialize the output from dump_stack()")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The mmap_sem for reading in validate_mm called from expand_stack is not
enough to prevent the argumented rbtree rb_subtree_gap information to
change from under us because expand_stack may be running from other
threads concurrently which will hold the mmap_sem for reading too.

The argumented rbtree is updated with vma_gap_update under the
page_table_lock so use it in browse_rb() too to avoid false positives.
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Tested-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

One of the randconfig build failed with the error:

  arch/m32r/kernel/smp.c: In function 'smp_flush_tlb_mm':
  arch/m32r/kernel/smp.c:283:20: error: subscripted value is neither array nor pointer nor vector
    mmc = &mm->context[cpu_id];
                      ^
  arch/m32r/kernel/smp.c: In function 'smp_flush_tlb_page':
  arch/m32r/kernel/smp.c:353:20: error: subscripted value is neither array nor pointer nor vector
    mmc = &mm->context[cpu_id];
                      ^
  arch/m32r/kernel/smp.c: In function 'smp_invalidate_interrupt':
  arch/m32r/kernel/smp.c:479:41: error: subscripted value is neither array nor pointer nor vector
    unsigned long *mmc = &flush_mm->context[cpu_id];

It turned out that CONFIG_SMP was defined but CONFIG_MMU was not
defined.  But arch/m32r/include/asm/mmu.h only defines mm_context_t as
an array when both CONFIG_SMP and CONFIG_MMU are defined.  And
arch/m32r/kernel/smp.c is always using context as an array.  So without
MMU SMP can not work.
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Previously the pfn_mkwrite() fault handler for raw block devices called
bldev_dax_fault() -> __dax_fault() to do a full DAX page fault.

Really what the pfn_mkwrite() fault handler needs to do is call
dax_pfn_mkwrite() to make sure that the radix tree entry for the given
PTE is marked as dirty so that a follow-up fsync or msync call will
flush it durably to media.

Fixes: 5a023cdb ("block: enable dax for raw block devices")
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A random wakeup can get us out of sigsuspend() without TIF_SIGPENDING
being set.

Avoid that by making sure we were signaled, like sys_pause() does.
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* pm-core:
  PM: Avoid false-positive warnings in dev_pm_domain_set()
  ACPI / LPSS: set PM domain via helper setter

* pm-domains:
  PM / Domains: Silence compiler warning for an unused function