From 855c7e9b9c2c39fb8d108ac70d0eed530f80a2aa Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 25 Mar 2020 12:12:59 -0700 Subject: KVM: x86: Fix BUILD_BUG() in __cpuid_entry_get_reg() w/ CONFIG_UBSAN=y Take the target reg in __cpuid_entry_get_reg() instead of a pointer to a struct cpuid_reg. When building with -fsanitize=alignment (enabled by CONFIG_UBSAN=y), some versions of gcc get tripped up on the pointer and trigger the BUILD_BUG(). Reported-by: Randy Dunlap Fixes: d8577a4c238f8 ("KVM: x86: Do host CPUID at load time to mask KVM cpu caps") Fixes: 4c61534aaae2a ("KVM: x86: Introduce cpuid_entry_{get,has}() accessors") Signed-off-by: Sean Christopherson Message-Id: <20200325191259.23559-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/cpuid.h | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index b18c31a26cc2..901cd1fdecd9 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -269,7 +269,7 @@ static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask) cpuid_count(cpuid.function, cpuid.index, &entry.eax, &entry.ebx, &entry.ecx, &entry.edx); - kvm_cpu_caps[leaf] &= *__cpuid_entry_get_reg(&entry, &cpuid); + kvm_cpu_caps[leaf] &= *__cpuid_entry_get_reg(&entry, cpuid.reg); } void kvm_set_cpu_caps(void) diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index 23b4cd1ad986..63a70f6a3df3 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -99,9 +99,9 @@ static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_featu } static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, - const struct cpuid_reg *cpuid) + u32 reg) { - switch (cpuid->reg) { + switch (reg) { case CPUID_EAX: return &entry->eax; case CPUID_EBX: @@ -121,7 +121,7 @@ static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, { const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature); - return __cpuid_entry_get_reg(entry, &cpuid); + return __cpuid_entry_get_reg(entry, cpuid.reg); } static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry, @@ -189,7 +189,7 @@ static __always_inline u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu, if (!entry) return NULL; - return __cpuid_entry_get_reg(entry, &cpuid); + return __cpuid_entry_get_reg(entry, cpuid.reg); } static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu, -- cgit v1.2.3