From: Alexandru Elisei alexandru.elisei@arm.com
mainline inclusion from mainline-v5.11-rc1 commit 9bbfa4b565379eeb2fb8fdbcc9979549ae0e48d9 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4NP0K CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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When enabling the PMU in kvm_arm_pmu_v3_enable(), KVM returns early if the PMU flag created is false and skips any other checks. Because PMU emulation is gated only on the VCPU feature being set, this makes it possible for userspace to get away with setting the VCPU feature but not doing any initialization for the PMU. Fix it by returning an error when trying to run the VCPU if the PMU hasn't been initialized correctly.
The PMU is marked as created only if the interrupt ID has been set when using an in-kernel irqchip. This means the same check in kvm_arm_pmu_v3_enable() is redundant, remove it.
Signed-off-by: Alexandru Elisei alexandru.elisei@arm.com Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20201126144916.164075-1-alexandru.elisei@arm.com Signed-off-by: Jingyi Wang wangjingyi11@huawei.com Reviewed-by: Zenghui Yu yuzenghui@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- arch/arm64/kvm/pmu-emul.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index a2a20f358f13..00bf8733e718 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -830,9 +830,12 @@ bool kvm_arm_support_pmu_v3(void)
int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu) { - if (!vcpu->arch.pmu.created) + if (!kvm_vcpu_has_pmu(vcpu)) return 0;
+ if (!vcpu->arch.pmu.created) + return -EINVAL; + /* * A valid interrupt configuration for the PMU is either to have a * properly configured interrupt number and using an in-kernel @@ -840,9 +843,6 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu) */ if (irqchip_in_kernel(vcpu->kvm)) { int irq = vcpu->arch.pmu.irq_num; - if (!kvm_arm_pmu_irq_initialized(vcpu)) - return -EINVAL; - /* * If we are using an in-kernel vgic, at this point we know * the vgic will be initialized, so we can check the PMU irq