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authorNadav Amit <namit@cs.technion.ac.il>2014-09-18 22:39:37 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-14 08:59:55 -0800
commit9cbba3890c81368ba739ebf2468767e5a306d489 (patch)
tree5c482ef2a2be5711acc49dd99cedad81b5c6add3 /arch/x86/kvm
parent76b73a19275a8eea9e460f348bf14b65d90ca6fd (diff)
KVM: x86: Fix wrong masking on relative jump/call
commit 05c83ec9b73c8124555b706f6af777b10adf0862 upstream. Relative jumps and calls do the masking according to the operand size, and not according to the address size as the KVM emulator does today. This patch fixes KVM behavior. Signed-off-by: Nadav Amit <namit@cs.technion.ac.il> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/emulate.c27
1 files changed, 22 insertions, 5 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 7bff3e2a7a11..44fc76b8b3fc 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -498,11 +498,6 @@ static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc)
masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc);
}
-static inline void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
-{
- register_address_increment(ctxt, &ctxt->_eip, rel);
-}
-
static u32 desc_limit_scaled(struct desc_struct *desc)
{
u32 limit = get_desc_limit(desc);
@@ -576,6 +571,28 @@ static int emulate_nm(struct x86_emulate_ctxt *ctxt)
return emulate_exception(ctxt, NM_VECTOR, 0, false);
}
+static inline void assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst)
+{
+ switch (ctxt->op_bytes) {
+ case 2:
+ ctxt->_eip = (u16)dst;
+ break;
+ case 4:
+ ctxt->_eip = (u32)dst;
+ break;
+ case 8:
+ ctxt->_eip = dst;
+ break;
+ default:
+ WARN(1, "unsupported eip assignment size\n");
+ }
+}
+
+static inline void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
+{
+ assign_eip_near(ctxt, ctxt->_eip + rel);
+}
+
static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg)
{
u16 selector;