[PATCH 1/5] kvm tools: arm: don't crash when no compatible CPU is found

[Will Deacon <will.deacon@arm.com>]

From: Marc Zyngier <Marc.Zyngier@arm.com>

If the kernel against which kvm tools was compiled supports more
CPU types than kvm tools does, then we can hit a situation where
we dereference an empty target slot.

Just stepping over empty slots fixes the issue.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 tools/kvm/arm/kvm-cpu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/kvm/arm/kvm-cpu.c b/tools/kvm/arm/kvm-cpu.c
index 7a0eff45..2716690 100644
--- a/tools/kvm/arm/kvm-cpu.c
+++ b/tools/kvm/arm/kvm-cpu.c
@@ -56,6 +56,8 @@ struct kvm_cpu *kvm_cpu__arch_init(struct kvm *kvm, unsigned long cpu_id)
 
 	/* Find an appropriate target CPU type. */
 	for (i = 0; i < ARRAY_SIZE(kvm_arm_targets); ++i) {
+		if (!kvm_arm_targets[i])
+			continue;
 		vcpu_init.target = kvm_arm_targets[i]->id;
 		err = ioctl(vcpu->vcpu_fd, KVM_ARM_VCPU_INIT, &vcpu_init);
 		if (!err)
-- 
1.8.0