From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Fri, 19 Aug 2016 13:38:11 +0100 Subject: [PATCH 1/5] arm/arm64: KVM: Don't BUG_ON if IT bits are set in ARM mode In-Reply-To: <1471610295-1456-1-git-send-email-marc.zyngier@arm.com> References: <1471610295-1456-1-git-send-email-marc.zyngier@arm.com> Message-ID: <1471610295-1456-2-git-send-email-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The ARM ARM asserts that having the IT bits set in ARM mode is unpredictable. But should a CPU do that (and still be able to run correctly), we shouldn't kill the system. So let's drop the BUG_ON that checks for this, as it is not very helpful. Signed-off-by: Marc Zyngier --- arch/arm/kvm/emulate.c | 4 +--- arch/arm64/kvm/emulate.c | 4 +--- 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c index af93e3f..eda9ddd 100644 --- a/arch/arm/kvm/emulate.c +++ b/arch/arm/kvm/emulate.c @@ -221,9 +221,7 @@ static void kvm_adjust_itstate(struct kvm_vcpu *vcpu) unsigned long cpsr = *vcpu_cpsr(vcpu); bool is_arm = !(cpsr & PSR_T_BIT); - BUG_ON(is_arm && (cpsr & PSR_IT_MASK)); - - if (!(cpsr & PSR_IT_MASK)) + if (is_arm || !(cpsr & PSR_IT_MASK)) return; cond = (cpsr & 0xe000) >> 13; diff --git a/arch/arm64/kvm/emulate.c b/arch/arm64/kvm/emulate.c index f87d8fb..df76590 100644 --- a/arch/arm64/kvm/emulate.c +++ b/arch/arm64/kvm/emulate.c @@ -120,9 +120,7 @@ static void kvm_adjust_itstate(struct kvm_vcpu *vcpu) unsigned long cpsr = *vcpu_cpsr(vcpu); bool is_arm = !(cpsr & COMPAT_PSR_T_BIT); - BUG_ON(is_arm && (cpsr & COMPAT_PSR_IT_MASK)); - - if (!(cpsr & COMPAT_PSR_IT_MASK)) + if (is_arm || !(cpsr & COMPAT_PSR_IT_MASK)) return; cond = (cpsr & 0xe000) >> 13; -- 2.1.4