KVM: arm64: Fix kvm_reset_vcpu() return code being incorrect with SVE

If SVE is enabled then 'ret' can be assigned the return value of
kvm_vcpu_enable_sve() which may be 0 causing future "goto out" sites to
erroneously return 0 on failure rather than -EINVAL as expected.

Remove the initialisation of 'ret' and make setting the return value
explicit to avoid this situation in the future.

Fixes: 9a3cdf26e3 ("KVM: arm64/sve: Allow userspace to enable SVE for vcpus")
Cc: stable@vger.kernel.org
Reported-by: James Morse <james.morse@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200617105456.28245-1-steven.price@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Steven Price 2020-06-17 11:54:56 +01:00 committed by Greg Kroah-Hartman
parent a494529add
commit 79aaeec712

View File

@ -258,7 +258,7 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
int kvm_reset_vcpu(struct kvm_vcpu *vcpu) int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
{ {
const struct kvm_regs *cpu_reset; const struct kvm_regs *cpu_reset;
int ret = -EINVAL; int ret;
bool loaded; bool loaded;
/* Reset PMU outside of the non-preemptible section */ /* Reset PMU outside of the non-preemptible section */
@ -281,15 +281,19 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) || if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) ||
test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) { test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) {
if (kvm_vcpu_enable_ptrauth(vcpu)) if (kvm_vcpu_enable_ptrauth(vcpu)) {
ret = -EINVAL;
goto out; goto out;
}
} }
switch (vcpu->arch.target) { switch (vcpu->arch.target) {
default: default:
if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) { if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
if (!cpu_has_32bit_el1()) if (!cpu_has_32bit_el1()) {
ret = -EINVAL;
goto out; goto out;
}
cpu_reset = &default_regs_reset32; cpu_reset = &default_regs_reset32;
} else { } else {
cpu_reset = &default_regs_reset; cpu_reset = &default_regs_reset;