On 22/08/2024 05:04, Aneesh Kumar K.V wrote:
> Steven Price <steven.price@xxxxxxx> writes:
>
> ....
>
>> +static int rec_exit_ripas_change(struct kvm_vcpu *vcpu)
>> +{
>> + struct kvm *kvm = vcpu->kvm;
>> + struct realm *realm = &kvm->arch.realm;
>> + struct realm_rec *rec = &vcpu->arch.rec;
>> + unsigned long base = rec->run->exit.ripas_base;
>> + unsigned long top = rec->run->exit.ripas_top;
>> + unsigned long ripas = rec->run->exit.ripas_value & 1;
>> + unsigned long top_ipa;
>> + int ret = -EINVAL;
>> +
>> + if (realm_is_addr_protected(realm, base) &&
>> + realm_is_addr_protected(realm, top - 1)) {
>> + kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_cache,
>> + kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu));
>> + write_lock(&kvm->mmu_lock);
>> + ret = realm_set_ipa_state(vcpu, base, top, ripas, &top_ipa);
>> + write_unlock(&kvm->mmu_lock);
>> + }
>> +
>> + WARN(ret && ret != -ENOMEM,
>> + "Unable to satisfy SET_IPAS for %#lx - %#lx, ripas: %#lx\n",
>> + base, top, ripas);
>> +
>> + /* Exit to VMM to complete the change */
>> + kvm_prepare_memory_fault_exit(vcpu, base, top_ipa - base, false, false,
>> + ripas == 1);
>> +
>> + return 0;
>> +}
>> +
>
> arch/arm64/kvm/rme-exit.c:100:6: warning: variable 'top_ipa' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
> if (realm_is_addr_protected(realm, base) &&
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> arch/arm64/kvm/rme-exit.c:114:44: note: uninitialized use occurs here
> kvm_prepare_memory_fault_exit(vcpu, base, top_ipa - base, false, false,
> ^~~~~~~
I'm not sure why I didn't notice this before, if the condition is false
then we're hitting the WARN (i.e. this shouldn't happen), but I should
fix that up to handle the situation better.
Steve
