From fe85ce31b2891611a2e4d788872be815cea85a4b Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 27 Nov 2024 16:55:34 -0800 Subject: [PATCH] KVM: selftests: Assert that vcpu_{g,s}et_reg() won't truncate Assert that the register being read/written by vcpu_{g,s}et_reg() is no larger than a uint64_t, i.e. that a selftest isn't unintentionally truncating the value being read/written. Ideally, the assert would be done at compile-time, but that would limit the checks to hardcoded accesses and/or require fancier compile-time assertion infrastructure to filter out dynamic usage. Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20241128005547.4077116-4-seanjc@google.com Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/include/kvm_util.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index 287a3ec06df47..4c4e5a847f67c 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -707,6 +707,8 @@ static inline uint64_t vcpu_get_reg(struct kvm_vcpu *vcpu, uint64_t id) uint64_t val; struct kvm_one_reg reg = { .id = id, .addr = (uint64_t)&val }; + TEST_ASSERT(KVM_REG_SIZE(id) <= sizeof(val), "Reg %lx too big", id); + vcpu_ioctl(vcpu, KVM_GET_ONE_REG, ®); return val; } @@ -714,6 +716,8 @@ static inline void vcpu_set_reg(struct kvm_vcpu *vcpu, uint64_t id, uint64_t val { struct kvm_one_reg reg = { .id = id, .addr = (uint64_t)&val }; + TEST_ASSERT(KVM_REG_SIZE(id) <= sizeof(val), "Reg %lx too big", id); + vcpu_ioctl(vcpu, KVM_SET_ONE_REG, ®); } -- 2.50.1