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linux/virt/kvm/arm
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Andre Przywara b3e336de65 KVM: arm/arm64: Fix reference to uninitialised VGIC 
commit b3aff6ccbb upstream.

Commit 4b4b4512da ("arm/arm64: KVM: Rework the arch timer to use
level-triggered semantics") brought the virtual architected timer
closer to the VGIC. There is one occasion were we don't properly
check for the VGIC actually having been initialized before, but
instead go on to check the active state of some IRQ number.
If userland hasn't instantiated a virtual GIC, we end up with a
kernel NULL pointer dereference:
=========
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc9745c5000
[00000000] *pgd=00000009f631e003, *pud=00000009f631e003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#2] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 2144 Comm: kvm_simplest-ar Tainted: G      D 4.5.0-rc2+ #1300
Hardware name: ARM Juno development board (r1) (DT)
task: ffffffc976da8000 ti: ffffffc976e28000 task.ti: ffffffc976e28000
PC is at vgic_bitmap_get_irq_val+0x78/0x90
LR is at kvm_vgic_map_is_active+0xac/0xc8
pc : [<ffffffc0000b7e28>] lr : [<ffffffc0000b972c>] pstate: 20000145
....
=========

Fix this by bailing out early of kvm_timer_flush_hwstate() if we don't
have a VGIC at all.

Reported-by: Cosmin Gorgovan <cosmin@linux-geek.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2016-02-25 12:01:20 -08:00
..
arch_timer.c KVM: arm/arm64: Fix reference to uninitialised VGIC 2016-02-25 12:01:20 -08:00
trace.h arm/arm64: KVM: Add tracepoints for vgic and timer 2015-10-22 23:01:48 +02:00
vgic-v2-emul.c KVM: arm/arm64: rework MMIO abort handling to use KVM MMIO bus 2015-03-30 17:07:19 +01:00
vgic-v2.c KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr() 2015-11-04 15:29:49 +01:00
vgic-v3-emul.c KVM: arm: vgic: Drop useless Group0 warning 2015-06-17 09:58:12 +01:00
vgic-v3.c KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr() 2015-11-04 15:29:49 +01:00
vgic.c KVM: arm/arm64: vgic: Fix kvm_vgic_map_is_active's dist check 2015-12-11 16:33:31 +00:00
vgic.h KVM: arm/arm64: rework MMIO abort handling to use KVM MMIO bus 2015-03-30 17:07:19 +01:00