linux-stable.git/arch/arm/include, branch v3.18.35

ARM: 8457/1: psci-smp is built only for SMP

2016-04-12T21:06:25+00:00

[ Upstream commit be95485a0b8288a93402705730d3ea32f9f812b9 ]

The PSCI SMP implementation is built only when both CONFIG_SMP and
CONFIG_ARM_PSCI are set, so a configuration that has the latter
but not the former can get a link error when it tries to call
psci_smp_available().

arch/arm/mach-tegra/built-in.o: In function `tegra114_cpuidle_init':
cpuidle-tegra114.c:(.init.text+0x52a): undefined reference to `psci_smp_available'

This corrects the #ifdef in the psci.h header file to match the
Makefile conditional we have for building that function.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Russell King 
Signed-off-by: Sasha Levin

ARM: 8320/1: fix integer overflow in ELF_ET_DYN_BASE

2015-05-17T23:11:57+00:00

[ Upstream commit 8defb3367fcd19d1af64c07792aade0747b54e0f ]

Usually ELF_ET_DYN_BASE is 2/3 of TASK_SIZE. With 3G/1G user/kernel
split this is not so, because 2*TASK_SIZE overflows 32 bits,
so the actual value of ELF_ET_DYN_BASE is:
	(2 * TASK_SIZE / 3) = 0x2a000000

When ASLR is disabled PIE binaries will load at ELF_ET_DYN_BASE address.
On 32bit platforms AddressSanitzer uses addresses [0x20000000 - 0x40000000]
for shadow memory [1]. So ASan doesn't work for PIE binaries when ASLR disabled
as it fails to map shadow memory.
Also after Kees's 'split ET_DYN ASLR from mmap ASLR' patchset PIE binaries
has a high chance of loading somewhere in between [0x2a000000 - 0x40000000]
even if ASLR enabled. This makes ASan with PIE absolutely incompatible.

Fix overflow by dividing TASK_SIZE prior to multiplying.
After this patch ELF_ET_DYN_BASE equals to (for CONFIG_VMSPLIT_3G=y):
	(TASK_SIZE / 3 * 2) = 0x7f555554

[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm#Mapping

Signed-off-by: Andrey Ryabinin 
Reported-by: Maria Guseva 
Cc: stable@vger.kernel.org
Signed-off-by: Russell King 
Signed-off-by: Sasha Levin

KVM: arm/arm64: check IRQ number on userland injection

2015-05-17T23:11:50+00:00

[ Upstream commit fd1d0ddf2ae92fb3df42ed476939861806c5d785 ]

When userland injects a SPI via the KVM_IRQ_LINE ioctl we currently
only check it against a fixed limit, which historically is set
to 127. With the new dynamic IRQ allocation the effective limit may
actually be smaller (64).
So when now a malicious or buggy userland injects a SPI in that
range, we spill over on our VGIC bitmaps and bytemaps memory.
I could trigger a host kernel NULL pointer dereference with current
mainline by injecting some bogus IRQ number from a hacked kvmtool:
-----------------
....
DEBUG: kvm_vgic_inject_irq(kvm, cpu=0, irq=114, level=1)
DEBUG: vgic_update_irq_pending(kvm, cpu=0, irq=114, level=1)
DEBUG: IRQ #114 still in the game, writing to bytemap now...
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc07652e000
[00000000] *pgd=00000000f658b003, *pud=00000000f658b003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 1053 Comm: lkvm-msi-irqinj Not tainted 4.0.0-rc7+ #3027
Hardware name: FVP Base (DT)
task: ffffffc0774e9680 ti: ffffffc0765a8000 task.ti: ffffffc0765a8000
PC is at kvm_vgic_inject_irq+0x234/0x310
LR is at kvm_vgic_inject_irq+0x30c/0x310
pc : [] lr : [] pstate: 80000145
.....

So this patch fixes this by checking the SPI number against the
actual limit. Also we remove the former legacy hard limit of
127 in the ioctl code.

Signed-off-by: Andre Przywara 
Reviewed-by: Christoffer Dall 
CC:  # 4.0, 3.19, 3.18
[maz: wrap KVM_ARM_IRQ_GIC_MAX with #ifndef __KERNEL__,
as suggested by Christopher Covington]
Signed-off-by: Marc Zyngier 
Signed-off-by: Sasha Levin

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

2015-05-11T11:07:37+00:00

commit 04b8dc85bf4a64517e3cf20e409eeaa503b15cc1 upstream.

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: Sasha Levin

arm64: KVM: Fix stage-2 PGD allocation to have per-page refcounting

2015-05-11T11:07:36+00:00

commit a987370f8e7a1677ae385042644326d9cd145a20 upstream.

We're using __get_free_pages with to allocate the guest's stage-2
PGD. The standard behaviour of this function is to return a set of
pages where only the head page has a valid refcount.

This behaviour gets us into trouble when we're trying to increment
the refcount on a non-head page:

page:ffff7c00cfb693c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: VM_BUG_ON_PAGE((*({ __attribute__((unused)) typeof((&page->_count)->counter) __var = ( typeof((&page->_count)->counter)) 0; (volatile typeof((&page->_count)->counter) *)&((&page->_count)->counter); })) <= 0)
BUG: failure at include/linux/mm.h:548/get_page()!
Kernel panic - not syncing: BUG!
CPU: 1 PID: 1695 Comm: kvm-vcpu-0 Not tainted 4.0.0-rc1+ #3825
Hardware name: APM X-Gene Mustang board (DT)
Call trace:
[] dump_backtrace+0x0/0x13c
[] show_stack+0x10/0x1c
[] dump_stack+0x74/0x94
[] panic+0x100/0x240
[] stage2_get_pmd+0x17c/0x2bc
[] kvm_handle_guest_abort+0x4b4/0x6b0
[] handle_exit+0x58/0x180
[] kvm_arch_vcpu_ioctl_run+0x114/0x45c
[] kvm_vcpu_ioctl+0x2e0/0x754
[] do_vfs_ioctl+0x424/0x5c8
[] SyS_ioctl+0x40/0x78
CPU0: stopping

A possible approach for this is to split the compound page using
split_page() at allocation time, and change the teardown path to
free one page at a time.  It turns out that alloc_pages_exact() and
free_pages_exact() does exactly that.

While we're at it, the PGD allocation code is reworked to reduce
duplication.

This has been tested on an X-Gene platform with a 4kB/48bit-VA host
kernel, and kvmtool hacked to place memory in the second page of
the hardware PGD (PUD for the host kernel). Also regression-tested
on a Cubietruck (Cortex-A7).

 [ Reworked to use alloc_pages_exact() and free_pages_exact() and to
   return pointers directly instead of by reference as arguments
    - Christoffer ]

Reported-by: Mark Rutland 
Signed-off-by: Marc Zyngier 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Sasha Levin

ARM: KVM: Fix size check in __coherent_cache_guest_page

2015-05-11T11:07:36+00:00

commit a050dfb21cc22ac0c666d52531040c1bc48184cc upstream.

The check is supposed to catch page-unaligned sizes, not the inverse.

Signed-off-by: Jan Kiszka 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Sasha Levin

arm/arm64: KVM: Use kernel mapping to perform invalidation on page fault

2015-05-11T11:07:36+00:00

commit 0d3e4d4fade6b04e933b11e69e80044f35e9cd60 upstream.

When handling a fault in stage-2, we need to resync I$ and D$, just
to be sure we don't leave any old cache line behind.

That's very good, except that we do so using the *user* address.
Under heavy load (swapping like crazy), we may end up in a situation
where the page gets mapped in stage-2 while being unmapped from
userspace by another CPU.

At that point, the DC/IC instructions can generate a fault, which
we handle with kvm->mmu_lock held. The box quickly deadlocks, user
is unhappy.

Instead, perform this invalidation through the kernel mapping,
which is guaranteed to be present. The box is much happier, and so
am I.

Signed-off-by: Marc Zyngier 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Sasha Levin

arm/arm64: KVM: Invalidate data cache on unmap

2015-05-11T11:07:35+00:00

commit 363ef89f8e9bcedc28b976d0fe2d858fe139c122 upstream.

Let's assume a guest has created an uncached mapping, and written
to that page. Let's also assume that the host uses a cache-coherent
IO subsystem. Let's finally assume that the host is under memory
pressure and starts to swap things out.

Before this "uncached" page is evicted, we need to make sure
we invalidate potential speculated, clean cache lines that are
sitting there, or the IO subsystem is going to swap out the
cached view, loosing the data that has been written directly
into memory.

Signed-off-by: Marc Zyngier 
Signed-off-by: Christoffer Dall 
Signed-off-by: Shannon Zhao 
Signed-off-by: Sasha Levin

arm/arm64: KVM: Introduce stage2_unmap_vm

2015-05-11T11:07:32+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: Sasha Levin

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

2015-05-11T11:07:32+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: Sasha Levin