Patchwork kvm tools: powerpc: Fix init order for xics

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Submitter Michael Neuling
Date Aug. 20, 2013, 3:28 a.m.
Message ID <32637.1376969314@ale.ozlabs.ibm.com>
Download mbox | patch
Permalink /patch/268354/
State New
Headers show

Comments

Michael Neuling - Aug. 20, 2013, 3:28 a.m.
xics_init() assumes kvm->nrcpus is already setup.  kvm->nrcpus is setup
in kvm_cpu_init()

Unfortunately xics_init() and kvm_cpu_init() both use base_init().  So
depending on the order randomly determined by the compiler, xics_init()
may initialised see kvm->nrcpus as 0 and not setup any of the icp VCPU
pointers.  This manifests itself later in boot when trying to raise an
IRQ resulting in a null pointer deference/segv.

This moves xics_init() to use dev_base_init() to ensure it happens after
kvm_cpu_init().

Signed-off-by: Michael Neuling <mikey@neuling.org>

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Pekka Enberg - Aug. 27, 2013, 11:52 a.m.
On Tue, Aug 20, 2013 at 6:28 AM, Michael Neuling <mikey@neuling.org> wrote:
> xics_init() assumes kvm->nrcpus is already setup.  kvm->nrcpus is setup
> in kvm_cpu_init()
>
> Unfortunately xics_init() and kvm_cpu_init() both use base_init().  So
> depending on the order randomly determined by the compiler, xics_init()
> may initialised see kvm->nrcpus as 0 and not setup any of the icp VCPU
> pointers.  This manifests itself later in boot when trying to raise an
> IRQ resulting in a null pointer deference/segv.
>
> This moves xics_init() to use dev_base_init() to ensure it happens after
> kvm_cpu_init().
>
> Signed-off-by: Michael Neuling <mikey@neuling.org>

Applied, thanks a lot!
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Patch

diff --git a/tools/kvm/powerpc/xics.c b/tools/kvm/powerpc/xics.c
index cf64a08..c1ef35b 100644
--- a/tools/kvm/powerpc/xics.c
+++ b/tools/kvm/powerpc/xics.c
@@ -505,7 +505,7 @@  static int xics_init(struct kvm *kvm)
 
 	return 0;
 }
-base_init(xics_init);
+dev_base_init(xics_init);
 
 
 void kvm__irq_line(struct kvm *kvm, int irq, int level)