linux-stable.git/arch/arm/include/asm, branch v3.14.78

ARM: 8579/1: mm: Fix definition of pmd_mknotpresent

2016-08-20T09:53:21+00:00

commit 56530f5d2ddc9b9fade7ef8db9cb886e9dc689b5 upstream.

Currently pmd_mknotpresent will use a zero entry to respresent an
invalidated pmd.

Unfortunately this definition clashes with pmd_none, thus it is
possible for a race condition to occur if zap_pmd_range sees pmd_none
whilst __split_huge_pmd_locked is running too with pmdp_invalidate
just called.

This patch fixes the race condition by modifying pmd_mknotpresent to
create non-zero faulting entries (as is done in other architectures),
removing the ambiguity with pmd_none.

[catalin.marinas@arm.com: using L_PMD_SECT_VALID instead of PMD_TYPE_SECT]

Fixes: 8d9625070073 ("ARM: mm: Transparent huge page support for LPAE systems.")
Cc:  # 3.11+
Reported-by: Kirill A. Shutemov 
Acked-by: Will Deacon 
Cc: Russell King 
Signed-off-by: Steve Capper 
Signed-off-by: Catalin Marinas 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

ARM: 8578/1: mm: ensure pmd_present only checks the valid bit

2016-07-27T16:55:49+00:00

commit 624531886987f0f1b5d01fb598034d039198e090 upstream.

In a subsequent patch, pmd_mknotpresent will clear the valid bit of the
pmd entry, resulting in a not-present entry from the hardware's
perspective. Unfortunately, pmd_present simply checks for a non-zero pmd
value and will therefore continue to return true even after a
pmd_mknotpresent operation. Since pmd_mknotpresent is only used for
managing huge entries, this is only an issue for the 3-level case.

This patch fixes the 3-level pmd_present implementation to take into
account the valid bit. For bisectability, the change is made before the
fix to pmd_mknotpresent.

[catalin.marinas@arm.com: comment update regarding pmd_mknotpresent patch]

Fixes: 8d9625070073 ("ARM: mm: Transparent huge page support for LPAE systems.")
Cc: Russell King 
Cc: Steve Capper 
Signed-off-by: Will Deacon 
Signed-off-by: Catalin Marinas 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

ARM: sunxi: fix build for THUMB2_KERNEL

2015-08-17T03:51:48+00:00

commit 1146b600044de64af0ef775025731eeef1fa2189 upstream.

Building an SMP kernel for the sunxi platform with THUMB2 instructions
fails with this error at the moment:

headsmp.S:7: Error: Thumb encoding does not support an immediate here -- `msr cpsr_fsxc,#0xd3'

Since the generic secondary_startup function already does
the same thing in a safe way, we can just drop the private
sunxi implementation and jump straight to secondary_startup.

Signed-off-by: Arnd Bergmann 
Cc: Maxime Ripard 
Signed-off-by: Kevin Hilman 
Signed-off-by: Greg Kroah-Hartman

arm64: KVM: Do not use pgd_index to index stage-2 pgd

2015-07-10T17:38:00+00:00

commit 04b8dc85bf4a64517e3cf20e409eeaa503b15cc1 upstream.

[Since we don't backport commit c647355 (KVM: arm: Add initial dirty page
locking support) for linux-3.14.y, there is no stage2_wp_range in
arch/arm/kvm/mmu.c. So ignore the change in stage2_wp_range introduced
by this patch.]

The kernel's pgd_index macro is designed to index a normal, page
sized array. KVM is a bit diffferent, as we can use concatenated
pages to have a bigger address space (for example 40bit IPA with
4kB pages gives us an 8kB PGD.

In the above case, the use of pgd_index will always return an index
inside the first 4kB, which makes a guest that has memory above
0x8000000000 rather unhappy, as it spins forever in a page fault,
whist the host happilly corrupts the lower pgd.

The obvious fix is to get our own kvm_pgd_index that does the right
thing(tm).

Tested on X-Gene with a hacked kvmtool that put memory at a stupidly
high address.

Reviewed-by: Christoffer Dall 
Signed-off-by: Marc Zyngier 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Greg Kroah-Hartman

arm/arm64: KVM: Introduce stage2_unmap_vm

2015-07-04T02:49:07+00:00

commit 957db105c99792ae8ef61ffc9ae77d910f6471da upstream.

Introduce a new function to unmap user RAM regions in the stage2 page
tables.  This is needed on reboot (or when the guest turns off the MMU)
to ensure we fault in pages again and make the dcache, RAM, and icache
coherent.

Using unmap_stage2_range for the whole guest physical range does not
work, because that unmaps IO regions (such as the GIC) which will not be
recreated or in the best case faulted in on a page-by-page basis.

Call this function on secondary and subsequent calls to the
KVM_ARM_VCPU_INIT ioctl so that a reset VCPU will detect the guest
Stage-1 MMU is off when faulting in pages and make the caches coherent.

Acked-by: Marc Zyngier 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Greg Kroah-Hartman

arm/arm64: KVM: Reset the HCR on each vcpu when resetting the vcpu

2015-07-04T02:49:06+00:00

commit b856a59141b1066d3c896a0d0231f84dabd040af upstream.

When userspace resets the vcpu using KVM_ARM_VCPU_INIT, we should also
reset the HCR, because we now modify the HCR dynamically to
enable/disable trapping of guest accesses to the VM registers.

This is crucial for reboot of VMs working since otherwise we will not be
doing the necessary cache maintenance operations when faulting in pages
with the guest MMU off.

Acked-by: Marc Zyngier 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Greg Kroah-Hartman

ARM/arm64: KVM: fix use of WnR bit in kvm_is_write_fault()

2015-07-04T02:49:05+00:00

commit a7d079cea2dffb112e26da2566dd84c0ef1fce97 upstream.

[Since we don't backport commit 9804788 (arm/arm64: KVM: Support
KVM_CAP_READONLY_MEM), ingore the changes in kvm_handle_guest_abort
introduced by this patch.]

The ISS encoding for an exception from a Data Abort has a WnR
bit[6] that indicates whether the Data Abort was caused by a
read or a write instruction. While there are several fields
in the encoding that are only valid if the ISV bit[24] is set,
WnR is not one of them, so we can read it unconditionally.

Instead of fixing both implementations of kvm_is_write_fault()
in place, reimplement it just once using kvm_vcpu_dabt_iswrite(),
which already does the right thing with respect to the WnR bit.
Also fix up the callers to pass 'vcpu'

Acked-by: Laszlo Ersek 
Acked-by: Marc Zyngier 
Acked-by: Christoffer Dall 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Marc Zyngier 
Signed-off-by: Shannon Zhao 
Signed-off-by: Greg Kroah-Hartman

KVM: ARM/arm64: fix non-const declaration of function returning const

2015-06-29T19:25:38+00:00

commit 6951e48bff0b55d2a8e825a953fc1f8e3a34bf1c upstream.

Sparse kicks up about a type mismatch for kvm_target_cpu:

arch/arm64/kvm/guest.c:271:25: error: symbol 'kvm_target_cpu' redeclared with different type (originally declared at ./arch/arm64/include/asm/kvm_host.h:45) - different modifiers

so fix this by adding the missing const attribute to the function
declaration.

Cc: Christoffer Dall 
Cc: Marc Zyngier 
Signed-off-by: Will Deacon 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Greg Kroah-Hartman

arm/arm64: KVM: Fix and refactor unmap_range

2015-06-29T19:25:37+00:00

commit 4f853a714bf16338ff5261128e6c7ae2569e9505 upstream.

unmap_range() was utterly broken, to quote Marc, and broke in all sorts
of situations.  It was also quite complicated to follow and didn't
follow the usual scheme of having a separate iterating function for each
level of page tables.

Address this by refactoring the code and introduce a pgd_clear()
function.

Reviewed-by: Jungseok Lee 
Reviewed-by: Mario Smarduch 
Acked-by: Marc Zyngier 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Greg Kroah-Hartman

ARM: KVM: trap VM system registers until MMU and caches are ON

2015-05-17T16:53:52+00:00

commit 8034699a42d68043b495c7e0cfafccd920707ec8 upstream.

In order to be able to detect the point where the guest enables
its MMU and caches, trap all the VM related system registers.

Once we see the guest enabling both the MMU and the caches, we
can go back to a saner mode of operation, which is to leave these
registers in complete control of the guest.

Signed-off-by: Marc Zyngier 
Acked-by: Catalin Marinas 
Reviewed-by: Christoffer Dall 
Cc: Shannon Zhao 
Signed-off-by: Greg Kroah-Hartman