@@ -501,20 +501,15 @@ int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
struct kvm_cpuid2 *cpuid,
struct kvm_cpuid_entry2 __user *entries)
{
- int r;
-
- r = -E2BIG;
if (cpuid->nent < vcpu->arch.cpuid_nent)
- goto out;
- r = -EFAULT;
+ return -E2BIG;
+
if (copy_to_user(entries, vcpu->arch.cpuid_entries,
vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
- goto out;
- return 0;
+ return -EFAULT;
-out:
cpuid->nent = vcpu->arch.cpuid_nent;
- return r;
+ return 0;
}
/* Mask kvm_cpu_caps for @leaf with the raw CPUID capabilities of this CPU. */
Update cpuid->nent if and only if kvm_vcpu_ioctl_get_cpuid2() succeeds. The sole caller copies @cpuid to userspace only on success, i.e. the existing code effectively does nothing. Arguably, KVM should report the number of entries when returning -E2BIG so that userspace doesn't have to guess the size, but all other similar KVM ioctls() don't report the size either, i.e. userspace is conditioned to guess. Suggested-by: Takahiro Itazuri <itazur@amazon.com> Link: https://lore.kernel.org/all/20230410141820.57328-1-itazur@amazon.com Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/cpuid.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-)