On 05/13/2010 11:15 PM, Mohammed Gamal wrote:
On Thu, May 13, 2010 at 9:24 AM, Avi Kivity<avi@xxxxxxxxxx> wrote:
On 05/11/2010 07:52 PM, Mohammed Gamal wrote:
- Add 's' and 'g' field checks on segment registers
- Correct SS checks for request and descriptor privilege levels
Signed-off-by: Mohammed Gamal<m.gamal005@xxxxxxxxx>
---
arch/x86/kvm/vmx.c | 73
+++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 67 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 777e00d..9805c2a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2121,16 +2121,30 @@ static bool stack_segment_valid(struct kvm_vcpu
*vcpu)
vmx_get_segment(vcpu,&ss, VCPU_SREG_SS);
ss_rpl = ss.selector& SELECTOR_RPL_MASK;
- if (ss.unusable)
+ if (ss.dpl != ss_rpl) /* DPL != RPL */
+ return false;
+
+ if (ss.unusable) /* Short-circuit */
return true;
If ss.unusable, do the dpl and rpl have any meaning?
The idea is that dpl and rpl are checked on vmentry regardless of
whether ss is usable or not. While the other checks are performed only
if ss is usable.
Any reference to back this up? I think rpl is valid regardless of
ss.unusable (i.e. loading selector 0003 results in an unusable segment
with rpl=3), but I don't see how dpl can be valid in an unusable segment.
--
error compiling committee.c: too many arguments to function
--
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