linux-stable.git/arch/arm, branch v4.4.72

KVM: arm/arm64: Handle possible NULL stage2 pud when ageing pages

2017-06-14T11:16:25+00:00

commit d6dbdd3c8558cad3b6d74cc357b408622d122331 upstream.

Under memory pressure, we start ageing pages, which amounts to parsing
the page tables. Since we don't want to allocate any extra level,
we pass NULL for our private allocation cache. Which means that
stage2_get_pud() is allowed to fail. This results in the following
splat:

[ 1520.409577] Unable to handle kernel NULL pointer dereference at virtual address 00000008
[ 1520.417741] pgd = ffff810f52fef000
[ 1520.421201] [00000008] *pgd=0000010f636c5003, *pud=0000010f56f48003, *pmd=0000000000000000
[ 1520.429546] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[ 1520.435156] Modules linked in:
[ 1520.438246] CPU: 15 PID: 53550 Comm: qemu-system-aar Tainted: G        W       4.12.0-rc4-00027-g1885c397eaec #7205
[ 1520.448705] Hardware name: FOXCONN R2-1221R-A4/C2U4N_MB, BIOS G31FB12A 10/26/2016
[ 1520.463726] task: ffff800ac5fb4e00 task.stack: ffff800ce04e0000
[ 1520.469666] PC is at stage2_get_pmd+0x34/0x110
[ 1520.474119] LR is at kvm_age_hva_handler+0x44/0xf0
[ 1520.478917] pc : [] lr : [] pstate: 40000145
[ 1520.486325] sp : ffff800ce04e33d0
[ 1520.489644] x29: ffff800ce04e33d0 x28: 0000000ffff40064
[ 1520.494967] x27: 0000ffff27e00000 x26: 0000000000000000
[ 1520.500289] x25: ffff81051ba65008 x24: 0000ffff40065000
[ 1520.505618] x23: 0000ffff40064000 x22: 0000000000000000
[ 1520.510947] x21: ffff810f52b20000 x20: 0000000000000000
[ 1520.516274] x19: 0000000058264000 x18: 0000000000000000
[ 1520.521603] x17: 0000ffffa6fe7438 x16: ffff000008278b70
[ 1520.526940] x15: 000028ccd8000000 x14: 0000000000000008
[ 1520.532264] x13: ffff7e0018298000 x12: 0000000000000002
[ 1520.537582] x11: ffff000009241b93 x10: 0000000000000940
[ 1520.542908] x9 : ffff0000092ef800 x8 : 0000000000000200
[ 1520.548229] x7 : ffff800ce04e36a8 x6 : 0000000000000000
[ 1520.553552] x5 : 0000000000000001 x4 : 0000000000000000
[ 1520.558873] x3 : 0000000000000000 x2 : 0000000000000008
[ 1520.571696] x1 : ffff000008fd5000 x0 : ffff0000080b149c
[ 1520.577039] Process qemu-system-aar (pid: 53550, stack limit = 0xffff800ce04e0000)
[...]
[ 1521.510735] [] stage2_get_pmd+0x34/0x110
[ 1521.516221] [] kvm_age_hva_handler+0x44/0xf0
[ 1521.522054] [] handle_hva_to_gpa+0xb8/0xe8
[ 1521.527716] [] kvm_age_hva+0x44/0xf0
[ 1521.532854] [] kvm_mmu_notifier_clear_flush_young+0x70/0xc0
[ 1521.539992] [] __mmu_notifier_clear_flush_young+0x88/0xd0
[ 1521.546958] [] page_referenced_one+0xf0/0x188
[ 1521.552881] [] rmap_walk_anon+0xec/0x250
[ 1521.558370] [] rmap_walk+0x78/0xa0
[ 1521.563337] [] page_referenced+0x164/0x180
[ 1521.569002] [] shrink_active_list+0x178/0x3b8
[ 1521.574922] [] shrink_node_memcg+0x328/0x600
[ 1521.580758] [] shrink_node+0xc4/0x328
[ 1521.585986] [] do_try_to_free_pages+0xc0/0x340
[ 1521.592000] [] try_to_free_pages+0xcc/0x240
[...]

The trivial fix is to handle this NULL pud value early, rather than
dereferencing it blindly.

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

arm: KVM: Allow unaligned accesses at HYP

2017-06-14T11:16:21+00:00

commit 33b5c38852b29736f3b472dd095c9a18ec22746f upstream.

We currently have the HSCTLR.A bit set, trapping unaligned accesses
at HYP, but we're not really prepared to deal with it.

Since the rest of the kernel is pretty happy about that, let's follow
its example and set HSCTLR.A to zero. Modern CPUs don't really care.

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

ARM: dts: at91: sama5d3_xplained: not all ADC channels are available

2017-05-25T12:30:15+00:00

commit d3df1ec06353e51fc44563d2e7e18d42811af290 upstream.

Remove ADC channels that are not available by default on the sama5d3_xplained
board (resistor not populated) in order to not create confusion.

Signed-off-by: Ludovic Desroches 
Acked-by: Nicolas Ferre 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Greg Kroah-Hartman

ARM: dts: at91: sama5d3_xplained: fix ADC vref

2017-05-25T12:30:15+00:00

commit 9cdd31e5913c1f86dce7e201b086155b3f24896b upstream.

The voltage reference for the ADC is not 3V but 3.3V since it is connected to
VDDANA.

Signed-off-by: Ludovic Desroches 
Acked-by: Nicolas Ferre 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Greg Kroah-Hartman

ARM: tegra: paz00: Mark panel regulator as enabled on boot

2017-05-25T12:30:07+00:00

commit 0c18927f51f4d390abdcf385bff5f995407ee732 upstream.

Current U-Boot enables the display already. Marking the regulator as
enabled on boot fixes sporadic panel initialization failures.

Signed-off-by: Marc Dietrich 
Tested-by: Misha Komarovskiy 
Signed-off-by: Thierry Reding 
Signed-off-by: Greg Kroah-Hartman

KVM: arm/arm64: fix races in kvm_psci_vcpu_on

2017-05-20T12:27:00+00:00

commit 6c7a5dce22b3f3cc44be098e2837fa6797edb8b8 upstream.

Fix potential races in kvm_psci_vcpu_on() by taking the kvm->lock
mutex.  In general, it's a bad idea to allow more than one PSCI_CPU_ON
to process the same target VCPU at the same time.  One such problem
that may arise is that one PSCI_CPU_ON could be resetting the target
vcpu, which fills the entire sys_regs array with a temporary value
including the MPIDR register, while another looks up the VCPU based
on the MPIDR value, resulting in no target VCPU found.  Resolves both
races found with the kvm-unit-tests/arm/psci unit test.

Reviewed-by: Marc Zyngier 
Reviewed-by: Christoffer Dall 
Reported-by: Levente Kurusa 
Suggested-by: Christoffer Dall 
Signed-off-by: Andrew Jones 
Signed-off-by: Christoffer Dall 
Signed-off-by: Greg Kroah-Hartman

ARM: OMAP5 / DRA7: Fix HYP mode boot for thumb2 build

2017-05-14T11:32:55+00:00

commit 448c077eeb02240c430db2a2c3bf5285a4c65d66 upstream.

'adr' yields a data-pointer, not a function-pointer.

Fixes: 999f934de195 ("ARM: omap5/dra7xx: Enable booting secondary
CPU in HYP mode")
Signed-off-by: Matthijs van Duin 
Signed-off-by: Tony Lindgren 
Signed-off-by: Greg Kroah-Hartman

ARM: 8452/3: PJ4: make coprocessor access sequences buildable in Thumb2 mode

2017-05-14T11:32:54+00:00

commit 5008efc83bf85b647aa1cbc44718b1675bbb7444 upstream.

The PJ4 inline asm sequence to write to cp15 cannot be built in Thumb-2
mode, due to the way it performs arithmetic on the program counter, so it
is built in ARM mode instead. However, building C files in ARM mode under
CONFIG_THUMB2_KERNEL is problematic, since the instrumentation performed
by subsystems like ftrace does not expect having to deal with interworking
branches.

Since the sequence in question is simply a poor man's ISB instruction,
let's use a straight 'isb' instead when building in Thumb2 mode. Thumb2
implies V7, so 'isb' should always be supported in that case.

Acked-by: Arnd Bergmann 
Acked-by: Nicolas Pitre 
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

ARM: OMAP2+: timer: add probe for clocksources

2017-05-03T04:19:47+00:00

commit 970f9091d25df14e9540ec7ff48a2f709e284cd1 upstream.

A few platforms are currently missing clocksource_probe() completely
in their time_init functionality. On OMAP3430 for example, this is
causing cpuidle to be pretty much dead, as the counter32k is not
going to be registered and instead a gptimer is used as a clocksource.
This will tick in periodic mode, preventing any deeper idle states.

While here, also drop one unnecessary check for populated DT before
existing clocksource_probe() call.

Signed-off-by: Tero Kristo 
Signed-off-by: Tony Lindgren 
Cc: Julia Lawall 
Signed-off-by: Greg Kroah-Hartman

kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd

2017-04-27T07:09:33+00:00

commit 8b3405e345b5a098101b0c31b264c812bba045d9 upstream.

In kvm_free_stage2_pgd() we don't hold the kvm->mmu_lock while calling
unmap_stage2_range() on the entire memory range for the guest. This could
cause problems with other callers (e.g, munmap on a memslot) trying to
unmap a range. And since we have to unmap the entire Guest memory range
holding a spinlock, make sure we yield the lock if necessary, after we
unmap each PUD range.

Fixes: commit d5d8184d35c9 ("KVM: ARM: Memory virtualization setup")
Cc: Paolo Bonzini 
Cc: Marc Zyngier 
Cc: Christoffer Dall 
Cc: Mark Rutland 
Signed-off-by: Suzuki K Poulose 
[ Avoid vCPU starvation and lockup detector warnings ]
Signed-off-by: Marc Zyngier 
Signed-off-by: Suzuki K Poulose 
Signed-off-by: Christoffer Dall 
Signed-off-by: Greg Kroah-Hartman