THP paths can defer splitting compound pages until after the actual
remap and TLB flushes to split a huge PMD/PUD. This causes radix
partition scope page table mappings to get out of synch with the host
qemu page table mappings.

This results in random memory corruption in the guest when running
with THP. The easiest way to reproduce is use KVM balloon to free up
a lot of memory in the guest and then shrink the balloon to give the
memory back, while some work is being done in the guest.

Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

At the moment the real mode handler of H_PUT_TCE calls iommu_tce_xchg_rm()
which in turn reads the old TCE and if it was a valid entry, marks
the physical page dirty if it was mapped for writing. Since it is in
real mode, realmode_pfn_to_page() is used instead of pfn_to_page()
to get the page struct. However SetPageDirty() itself reads the compound
page head and returns a virtual address for the head page struct and
setting dirty bit for that kills the system.

This adds additional dirty bit tracking into the MM/IOMMU API for use
in the real mode. Note that this does not change how VFIO and
KVM (in virtual mode) set this bit. The KVM (real mode) changes include:
- use the lowest bit of the cached host phys address to carry
the dirty bit;
- mark pages dirty when they are unpinned which happens when
the preregistered memory is released which always happens in virtual
mode;
- add mm_iommu_ua_mark_dirty_rm() helper to set delayed dirty bit;
- change iommu_tce_xchg_rm() to take the kvm struct for the mm to use
in the new mm_iommu_ua_mark_dirty_rm() helper;
- move iommu_tce_xchg_rm() to book3s_64_vio_hv.c (which is the only
caller anyway) to reduce the real mode KVM and IOMMU knowledge
across different subsystems.

This removes realmode_pfn_to_page() as it is not used anymore.

While we at it, remove some EXPORT_SYMBOL_GPL() as that code is for
the real mode only and modules cannot call it anyway.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Dan Carpenter reported that the untrusted data returns from kvm_register_read()
results in the following static checker warning:
  arch/x86/kvm/lapic.c:576 kvm_pv_send_ipi()
  error: buffer underflow 'map->phys_map' 's32min-s32max'

KVM guest can easily trigger this by executing the following assembly sequence
in Ring0:

mov $10, %rax
mov $0xFFFFFFFF, %rbx
mov $0xFFFFFFFF, %rdx
mov $0, %rsi
vmcall

As this will cause KVM to execute the following code-path:
vmx_handle_exit() -> handle_vmcall() -> kvm_emulate_hypercall() -> kvm_pv_send_ipi()
which will reach out-of-bounds access.

This patch fixes it by adding a check to kvm_pv_send_ipi() against map->max_apic_id,
ignoring destinations that are not present and delivering the rest. We also check
whether or not map->phys_map[min + i] is NULL since the max_apic_id is set to the
max apic id, some phys_map maybe NULL when apic id is sparse, especially kvm
unconditionally set max_apic_id to 255 to reserve enough space for any xAPIC ID.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Add second "if (min > map->max_apic_id)" to complete the fix. -Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

Consider the case L1 had a IRQ/NMI event until it executed
VMLAUNCH/VMRESUME which wasn't delivered because it was disallowed
(e.g. interrupts disabled). When L1 executes VMLAUNCH/VMRESUME,
L0 needs to evaluate if this pending event should cause an exit from
L2 to L1 or delivered directly to L2 (e.g. In case L1 don't intercept
EXTERNAL_INTERRUPT).

Usually this would be handled by L0 requesting a IRQ/NMI window
by setting VMCS accordingly. However, this setting was done on
VMCS01 and now VMCS02 is active instead. Thus, when L1 executes
VMLAUNCH/VMRESUME we force L0 to perform pending event evaluation by
requesting a KVM_REQ_EVENT.

Note that above scenario exists when L1 KVM is about to enter L2 but
requests an "immediate-exit". As in this case, L1 will
disable-interrupts and then send a self-IPI before entering L2.
Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com>
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

Merge tag 'kvm-arm-fixes-for-v4.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm

Fixes for KVM/ARM for Linux v4.19 v2:

 - Fix a VFP corruption in 32-bit guest
 - Add missing cache invalidation for CoW pages
 - Two small cleanups

KVM: s390: Fixes for 4.19

- Fallout from the hugetlbfs support: pfmf interpretion and locking
- VSIE: fix keywrapping for nested guests

The lock has never been used and the page tables are protected by
mmu_lock in struct kvm.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>

kvm_unmap_hva is long gone, and we only have kvm_unmap_hva_range to
deal with. Drop the now obsolete code.

Fixes: fb1522e0 ("KVM: update to new mmu_notifier semantic v2")
Cc: James Hogan <jhogan@kernel.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>

If trapping FPSIMD in the context of an AArch32 guest, it is critical
to set FPEXC32_EL2.EN to 1 so that the trapping is taken to EL2 and
not EL1.

Conversely, it is just as critical *not* to set FPEXC32_EL2.EN to 1
if we're not going to trap FPSIMD, as we then corrupt the existing
VFP state.

Moving the call to __activate_traps_fpsimd32 to the point where we
know for sure that we are going to trap ensures that we don't set that
bit spuriously.

Fixes: e6b673b7 ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing")
Cc: stable@vger.kernel.org # v4.18
Cc: Dave Martin <dave.martin@arm.com>
Reported-by: Alexander Graf <agraf@suse.de>
Tested-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>

When triggering a CoW, we unmap the RO page via an MMU notifier
(invalidate_range_start), and then populate the new PTE using another
one (change_pte). In the meantime, we'll have copied the old page
into the new one.

The problem is that the data for the new page is sitting in the
cache, and should the guest have an uncached mapping to that page
(or its MMU off), following accesses will bypass the cache.

In a way, this is similar to what happens on a translation fault:
We need to clean the page to the PoC before mapping it. So let's just
do that.

This fixes a KVM unit test regression observed on a HiSilicon platform,
and subsequently reproduced on Seattle.

Fixes: a9c0e12e ("KVM: arm/arm64: Only clean the dcache on translation fault")
Cc: stable@vger.kernel.org # v4.16+
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>

PPC KVM fixes for 4.19

Two small fixes for KVM on POWER machines; one fixes a bug where pages
might not get marked dirty, causing guest memory corruption on migration,
and the other fixes a bug causing reads from guest memory to use the
wrong guest real address for very large HPT guests (>256G of memory),
leading to failures in instruction emulation.

We have to do down_write on the mm semaphore to set a bitfield in the
mm context.
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: a4499382 ("KVM: s390: Add huge page enablement control")
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Copy the key mask to the right offset inside the shadow CRYCB

Fixes: bbeaa58b ("KVM: s390: vsie: support aes dea wrapping keys")
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Cc: stable@vger.kernel.org # v4.8+
Message-Id: <1535019956-23539-2-git-send-email-pmorel@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

We should not return with a lock.
We also have to increase the address when we do page clearing.

Fixes: bd096f64 ("KVM: s390: Add skey emulation fault handling")
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-Id: <20180830081355.59234-1-frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

Pull devicetree updates from Rob Herring:
 "A couple of new helper functions in preparation for some tree wide
  clean-ups.

  I'm sending these new helpers now for rc2 in order to simplify the
  dependencies on subsequent cleanups across the tree in 4.20"

* tag 'devicetree-fixes-for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: Add device_type access helper functions
  of: add node name compare helper functions
  of: add helper to lookup compatible child node

Pull ARM SoC fixes from Olof Johansson:
 "First batch of fixes post-merge window:

   - A handful of devicetree changes for i.MX2{3,8} to change over to
     new panel bindings. The platforms were moved from legacy
     framebuffers to DRM and some development board panels hadn't yet
     been converted.

   - OMAP fixes related to ti-sysc driver conversion fallout, fixing
     some register offsets, no_console_suspend fixes, etc.

   - Droid4 changes to fix flaky eMMC probing and vibrator DTS mismerge.

   - Fixed 0755->0644 permissions on a newly added file.

   - Defconfig changes to make ARM Versatile more useful with QEMU
     (helps testing).

   - Enable defconfig options for new TI SoC platform that was merged
     this window (AM6)"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  arm64: defconfig: Enable TI's AM6 SoC platform
  ARM: defconfig: Update the ARM Versatile defconfig
  ARM: dts: omap4-droid4: Fix emmc errors seen on some devices
  ARM: dts: Fix file permission for am335x-osd3358-sm-red.dts
  ARM: imx_v6_v7_defconfig: Select CONFIG_DRM_PANEL_SEIKO_43WVF1G
  ARM: mxs_defconfig: Select CONFIG_DRM_PANEL_SEIKO_43WVF1G
  ARM: dts: imx23-evk: Convert to the new display bindings
  ARM: dts: imx23-evk: Move regulators outside simple-bus
  ARM: dts: imx28-evk: Convert to the new display bindings
  ARM: dts: imx28-evk: Move regulators outside simple-bus
  Revert "ARM: dts: imx7d: Invert legacy PCI irq mapping"
  arm: dts: am4372: setup rtc as system-power-controller
  ARM: dts: omap4-droid4: fix vibrations on Droid 4
  bus: ti-sysc: Fix no_console_suspend handling
  bus: ti-sysc: Fix module register ioremap for larger offsets
  ARM: OMAP2+: Fix module address for modules using mpu_rt_idx
  ARM: OMAP2+: Fix null hwmod for ti-sysc debug

Pull x86 fixes from Thomas Gleixner:
 "Speculation:

   - Make the microcode check more robust

   - Make the L1TF memory limit depend on the internal cache physical
     address space and not on the CPUID advertised physical address
     space, which might be significantly smaller. This avoids disabling
     L1TF on machines which utilize the full physical address space.

   - Fix the GDT mapping for EFI calls on 32bit PTI

   - Fix the MCE nospec implementation to prevent #GP

  Fixes and robustness:

   - Use the proper operand order for LSL in the VDSO

   - Prevent NMI uaccess race against CR3 switching

   - Add a lockdep check to verify that text_mutex is held in
     text_poke() functions

   - Repair the fallout of giving native_restore_fl() a prototype

   - Prevent kernel memory dumps based on usermode RIP

   - Wipe KASAN shadow stack before rewinding the stack to prevent false
     positives

   - Move the AMS GOTO enforcement to the actual build stage to allow
     user API header extraction without a compiler

   - Fix a section mismatch introduced by the on demand VDSO mapping
     change

  Miscellaneous:

   - Trivial typo, GCC quirk removal and CC_SET/OUT() cleanups"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pti: Fix section mismatch warning/error
  x86/vdso: Fix lsl operand order
  x86/mce: Fix set_mce_nospec() to avoid #GP fault
  x86/efi: Load fixmap GDT in efi_call_phys_epilog()
  x86/nmi: Fix NMI uaccess race against CR3 switching
  x86: Allow generating user-space headers without a compiler
  x86/dumpstack: Don't dump kernel memory based on usermode RIP
  x86/asm: Use CC_SET()/CC_OUT() in __gen_sigismember()
  x86/alternatives: Lockdep-enforce text_mutex in text_poke*()
  x86/entry/64: Wipe KASAN stack shadow before rewind_stack_do_exit()
  x86/irqflags: Mark native_restore_fl extern inline
  x86/build: Remove jump label quirk for GCC older than 4.5.2
  x86/Kconfig: Fix trivial typo
  x86/speculation/l1tf: Increase l1tf memory limit for Nehalem+
  x86/spectre: Add missing family 6 check to microcode check

Pull CPU hotplug fix from Thomas Gleixner:
 "Remove the stale skip_onerr member from the hotplug states"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Remove skip_onerr field from cpuhp_step structure

Pull core fixes from Thomas Gleixner:
 "A small set of updates for core code:

   - Prevent tracing in functions which are called from trace patching
     via stop_machine() to prevent executing half patched function trace
     entries.

   - Remove old GCC workarounds

   - Remove pointless includes of notifier.h"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Remove workaround for unreachable warnings from old GCC
  notifier: Remove notifier header file wherever not used
  watchdog: Mark watchdog touch functions as notrace

Fix the section mismatch warning in arch/x86/mm/pti.c:

WARNING: vmlinux.o(.text+0x6972a): Section mismatch in reference from the function pti_clone_pgtable() to the function .init.text:pti_user_pagetable_walk_pte()
The function pti_clone_pgtable() references
the function __init pti_user_pagetable_walk_pte().
This is often because pti_clone_pgtable lacks a __init
annotation or the annotation of pti_user_pagetable_walk_pte is wrong.
FATAL: modpost: Section mismatches detected.

Fixes: 85900ea5 ("x86/pti: Map the vsyscall page if needed")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/43a6d6a3-d69d-5eda-da09-0b1c88215a2a@infradead.org

Merge tag 'omap-for-v4.19/fixes-v2-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes

Fixes for omap variants against v4.19-rc1

These are mostly fixes related to using ti-sysc interconnect target module
driver for accessing right register offsets for sgx and cpsw and for
no_console_suspend regression.

There is also a droid4 emmc fix where emmc may not get detected for some
models, and vibrator dts mismerge fix.

And we have a file permission fix for am335x-osd3358-sm-red.dts that
just got added. And we must tag RTC as system-power-controller for
am437x for PMIC to shut down during poweroff.

* tag 'omap-for-v4.19/fixes-v2-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: dts: omap4-droid4: Fix emmc errors seen on some devices
  ARM: dts: Fix file permission for am335x-osd3358-sm-red.dts
  arm: dts: am4372: setup rtc as system-power-controller
  ARM: dts: omap4-droid4: fix vibrations on Droid 4
  bus: ti-sysc: Fix no_console_suspend handling
  bus: ti-sysc: Fix module register ioremap for larger offsets
  ARM: OMAP2+: Fix module address for modules using mpu_rt_idx
  ARM: OMAP2+: Fix null hwmod for ti-sysc debug
Signed-off-by: Olof Johansson <olof@lixom.net>

In the __getcpu function, lsl is using the wrong target and destination
registers. Luckily, the compiler tends to choose %eax for both variables,
so it has been working so far.

Fixes: a582c540 ("x86/vdso: Use RDPID in preference to LSL when available")
Signed-off-by: Samuel Neves <sneves@dei.uc.pt>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180901201452.27828-1-sneves@dei.uc.pt

Pull watchdog fixlet from Wim Van Sebroeck:
 "Document support for r8a774a1"

* tag 'linux-watchdog-4.19-rc2' of git://www.linux-watchdog.org/linux-watchdog:
  dt-bindings: watchdog: renesas-wdt: Document r8a774a1 support

Pull clk fixes from Stephen Boyd:
 "Two small fixes, one for the x86 Stoney SoC to get a more accurate clk
  frequency and the other to fix a bad allocation in the Nuvoton NPCM7XX
  driver"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: x86: Set default parent to 48Mhz
  clk: npcm7xx: fix memory allocation

The trick with flipping bit 63 to avoid loading the address of the 1:1
mapping of the poisoned page while the 1:1 map is updated used to work when
unmapping the page. But it falls down horribly when attempting to directly
set the page as uncacheable.

The problem is that when the cache mode is changed to uncachable, the pages
needs to be flushed from the cache first. But the decoy address is
non-canonical due to bit 63 flipped, and the CLFLUSH instruction throws a
#GP fault.

Add code to change_page_attr_set_clr() to fix the address before calling
flush.

Fixes: 284ce401 ("x86/memory_failure: Introduce {set, clear}_mce_nospec()")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Link: https://lkml.kernel.org/r/20180831165506.GA9605@agluck-desk

Pull arm64 fixes from Will Deacon:
 "A few arm64 fixes came in this week, specifically fixing some nasty
  truncation of return values from firmware calls and resolving a
  VM_BUG_ON due to accessing uninitialised struct pages corresponding to
  NOMAP pages.

  Summary:

   - Fix typos in SVE documentation

   - Fix type-checking and implicit truncation for SMCCC calls

   - Force CONFIG_HOLES_IN_ZONE=y so that SLAB doesn't fall over NOMAP
     regions"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mm: always enable CONFIG_HOLES_IN_ZONE
  arm/arm64: smccc-1.1: Handle function result as parameters
  arm/arm64: smccc-1.1: Make return values unsigned long
  Documentation/arm64/sve: Couple of improvements and typos

When PTI is enabled on x86-32 the kernel uses the GDT mapped in the fixmap
for the simple reason that this address is also mapped for user-space.

The efi_call_phys_prolog()/efi_call_phys_epilog() wrappers change the GDT
to call EFI runtime services and switch back to the kernel GDT when they
return. But the switch-back uses the writable GDT, not the fixmap GDT.

When that happened and and the CPU returns to user-space it switches to the
user %cr3 and tries to restore user segment registers. This fails because
the writable GDT is not mapped in the user page-table, and without a GDT
the fault handlers also can't be launched. The result is a triple fault and
reboot of the machine.

Fix that by restoring the GDT back to the fixmap GDT which is also mapped
in the user page-table.

Fixes: 7757d607 x86/pti: ('Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32')
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: hpa@zytor.com
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/1535702738-10971-1-git-send-email-joro@8bytes.org

Pull xen fixes from Juergen Gross:

 - minor cleanup avoiding a warning when building with new gcc

 - a patch to add a new sysfs node for Xen frontend/backend drivers to
   make it easier to obtain the state of a pv device

 - two fixes for 32-bit pv-guests to avoid intermediate L1TF vulnerable
   PTEs

* tag 'for-linus-4.19b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: remove redundant variable save_pud
  xen: export device state to sysfs
  x86/pae: use 64 bit atomic xchg function in native_ptep_get_and_clear
  x86/xen: don't write ptes directly in 32-bit PV guests

Pull m68k fix from Geert Uytterhoeven:
 "Just a single fix for a bug introduced during the merge window: fix
  wrong date and time on PMU-based Macs"

* tag 'm68k-for-v4.19-tag2' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k/mac: Use correct PMU response format

Pull i2c fixes from Wolfram Sang:

 - regression fixes for i801 and designware

 - better API and leak fix for releasing DMA safe buffers

 - better greppable strings for the bitbang algorithm

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: sh_mobile: fix leak when using DMA bounce buffer
  i2c: sh_mobile: define start_ch() void as it only returns 0 anyhow
  i2c: refactor function to release a DMA safe buffer
  i2c: algos: bit: make the error messages grepable
  i2c: designware: Re-init controllers with pm_disabled set on resume
  i2c: i801: Allow ACPI AML access I/O ports not reserved for SMBus

A NMI can hit in the middle of context switching or in the middle of
switch_mm_irqs_off().  In either case, CR3 might not match current->mm,
which could cause copy_from_user_nmi() and friends to read the wrong
memory.

Fix it by adding a new nmi_uaccess_okay() helper and checking it in
copy_from_user_nmi() and in __copy_from_user_nmi()'s callers.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rik van Riel <riel@surriel.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/dd956eba16646fd0b15c3c0741269dfd84452dac.1535557289.git.luto@kernel.org

When bootstrapping an architecture, it's usual to generate the kernel's
user-space headers (make headers_install) before building a compiler.  Move
the compiler check (for asm goto support) to the archprepare target so that
it is only done when building code for the target.

Fixes: e501ce95 ("x86: Force asm-goto")
Reported-by: Helmut Grohne <helmutg@debian.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180829194317.GA4765@decadent.org.uk

show_opcodes() is used both for dumping kernel instructions and for dumping
user instructions. If userspace causes #PF by jumping to a kernel address,
show_opcodes() can be reached with regs->ip controlled by the user,
pointing to kernel code. Make sure that userspace can't trick us into
dumping kernel memory into dmesg.

Fixes: 7cccf072 ("x86/dumpstack: Add a show_ip() function")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: security@kernel.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180828154901.112726-1-jannh@google.com

In preparation to remove direct access to device_node.type, add
of_node_is_type() and of_node_get_device_type() helpers to check and
retrieve the device type.

Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

When notifiers were there, `skip_onerr` was used to avoid calling
particular step startup/teardown callbacks in the CPU up/down rollback
path, which made the hotplug asymmetric.

As notifiers are gone now after the full state machine conversion, the
`skip_onerr` field is no longer required.

Remove it from the structure and its usage.
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1535439294-31426-1-git-send-email-mojha@codeaurora.org

Commit 6d526ee2 ("arm64: mm: enable CONFIG_HOLES_IN_ZONE for NUMA")
only enabled HOLES_IN_ZONE for NUMA systems because the NUMA code was
choking on the missing zone for nomap pages. This problem doesn't just
apply to NUMA systems.

If the architecture doesn't set HAVE_ARCH_PFN_VALID, pfn_valid() will
return true if the pfn is part of a valid sparsemem section.

When working with multiple pages, the mm code uses pfn_valid_within()
to test each page it uses within the sparsemem section is valid. On
most systems memory comes in MAX_ORDER_NR_PAGES chunks which all
have valid/initialised struct pages. In this case pfn_valid_within()
is optimised out.

Systems where this isn't true (e.g. due to nomap) should set
HOLES_IN_ZONE and provide HAVE_ARCH_PFN_VALID so that mm tests each
page as it works with it.

Currently non-NUMA arm64 systems can't enable HOLES_IN_ZONE, leading to
a VM_BUG_ON():

| page:fffffdff802e1780 is uninitialized and poisoned
| raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
| raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
| page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
| ------------[ cut here ]------------
| kernel BUG at include/linux/mm.h:978!
| Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[...]
| CPU: 1 PID: 25236 Comm: dd Not tainted 4.18.0 #7
| Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
| pstate: 40000085 (nZcv daIf -PAN -UAO)
| pc : move_freepages_block+0x144/0x248
| lr : move_freepages_block+0x144/0x248
| sp : fffffe0071177680
[...]
| Process dd (pid: 25236, stack limit = 0x0000000094cc07fb)
| Call trace:
|  move_freepages_block+0x144/0x248
|  steal_suitable_fallback+0x100/0x16c
|  get_page_from_freelist+0x440/0xb20
|  __alloc_pages_nodemask+0xe8/0x838
|  new_slab+0xd4/0x418
|  ___slab_alloc.constprop.27+0x380/0x4a8
|  __slab_alloc.isra.21.constprop.26+0x24/0x34
|  kmem_cache_alloc+0xa8/0x180
|  alloc_buffer_head+0x1c/0x90
|  alloc_page_buffers+0x68/0xb0
|  create_empty_buffers+0x20/0x1ec
|  create_page_buffers+0xb0/0xf0
|  __block_write_begin_int+0xc4/0x564
|  __block_write_begin+0x10/0x18
|  block_write_begin+0x48/0xd0
|  blkdev_write_begin+0x28/0x30
|  generic_perform_write+0x98/0x16c
|  __generic_file_write_iter+0x138/0x168
|  blkdev_write_iter+0x80/0xf0
|  __vfs_write+0xe4/0x10c
|  vfs_write+0xb4/0x168
|  ksys_write+0x44/0x88
|  sys_write+0xc/0x14
|  el0_svc_naked+0x30/0x34
| Code: aa1303e0 90001a01 91296421 94008902 (d4210000)
| ---[ end trace 1601ba47f6e883fe ]---

Remove the NUMA dependency.

Link: https://www.spinics.net/lists/arm-kernel/msg671851.html
Cc: <stable@vger.kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com>
Tested-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Now that the 68k Mac port has adopted the via-pmu driver, it must decode
the PMU response accordingly otherwise the date and time will be wrong.

Fixes: ebd72227 ("macintosh/via-pmu: Replace via-pmu68k driver with via-pmu driver")
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

Pull drm fixes from Dave Airlie:
 "Regular fixes pull:

   - Mediatek has a bunch of fixes to their RDMA and Overlay engines.

   - i915 has some Cannonlake/Geminilake watermark workarounds, LSPCON
     fix, HDCP free fix, audio fix and a ppgtt reference counting fix.

   - amdgpu has some SRIOV, Kasan, memory leaks and other misc fixes"

* tag 'drm-fixes-2018-08-31' of git://anongit.freedesktop.org/drm/drm: (35 commits)
  drm/i915/audio: Hook up component bindings even if displays are disabled
  drm/i915: Increase LSPCON timeout
  drm/i915: Stop holding a ref to the ppgtt from each vma
  drm/i915: Free write_buf that we allocated with kzalloc.
  drm/i915: Fix glk/cnl display w/a #1175
  drm/amdgpu: Need to set moved to true when evict bo
  drm/amdgpu: Remove duplicated power source update
  drm/amd/display: Fix memory leak caused by missed dc_sink_release
  drm/amdgpu: fix holding mn_lock while allocating memory
  drm/amdgpu: Power on uvd block when hw_fini
  drm/amdgpu: Update power state at the end of smu hw_init.
  drm/amdgpu: Fix vce initialize failed on Kaveri/Mullins
  drm/amdgpu: Enable/disable gfx PG feature in rlc safe mode
  drm/amdgpu: Adjust the VM size based on system memory size v2
  drm/mediatek: fix connection from RDMA2 to DSI1
  drm/mediatek: update some variable name from ovl to comp
  drm/mediatek: use layer_nr function to get layer number to init plane
  drm/mediatek: add function to return RDMA layer number
  drm/mediatek: add function to return OVL layer number
  drm/mediatek: add function to get layer number for component
  ...

They are too noisy
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>