diff options
| author | Avi Kivity <avi@redhat.com> | 2012-05-13 19:53:23 +0300 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-05-16 16:03:19 -0300 |
| commit | 512d5649e8dc3ed36f2ebf0818da64a4d4c2544a (patch) | |
| tree | 75fa25fcf4c7e7fc8f9fc8ab4c2aa01227ab9983 /arch/x86/kvm/vmx.c | |
| parent | d54e4237bcbb400fda11c902fd538aa0b4805720 (diff) | |
KVM: VMX: Fix %ds/%es clobber
The vmx exit code unconditionally restores %ds and %es to __USER_DS. This
can override the user's values, since %ds and %es are not saved and restored
in x86_64 syscalls. In practice, this isn't dangerous since nobody uses
segment registers in long mode, least of all programs that use KVM.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3062ea95266..f2ee016e100 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6102,7 +6102,10 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx) static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) { struct vcpu_vmx *vmx = to_vmx(vcpu); + u16 _ds, _es; + savesegment(ds, _ds); + savesegment(es, _es); if (is_guest_mode(vcpu) && !vmx->nested.nested_run_pending) { struct vmcs12 *vmcs12 = get_vmcs12(vcpu); if (vmcs12->idt_vectoring_info_field & @@ -6263,7 +6266,8 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) } } - asm("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS)); + loadsegment(ds, _ds); + loadsegment(es, _es); vmx->loaded_vmcs->launched = 1; vmx->exit_reason = vmcs_read32(VM_EXIT_REASON); |