From: Keir Fraser <keir@xen.org>
Date: Fri, 23 Mar 2012 20:51:48 +0000 (+0000)
Subject: x86_emulate: Do not push an error code onto a #UD exception stack
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/success//%22http:/www.example.com/cgi/success/?a=commitdiff_plain;h=ebe5e562487f3f3bc814463ac42043fc0074b0f3;p=xen.git

x86_emulate: Do not push an error code onto a #UD exception stack

Signed-off-by: Keir Fraser <keir@xen.org>
---

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c b/xen/arch/x86/x86_emulate/x86_emulate.c
index 7f842ce0af..b894d807d5 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1429,7 +1429,7 @@ x86_emulate(
     }
 
     /* Lock prefix is allowed only on RMW instructions. */
-    generate_exception_if((d & Mov) && lock_prefix, EXC_UD, 0);
+    generate_exception_if((d & Mov) && lock_prefix, EXC_UD, -1);
 
     /* ModRM and SIB bytes. */
     if ( d & ModRM )
@@ -1712,12 +1712,12 @@ x86_emulate(
             lock_prefix &&
             ((b < 0x20) || (b > 0x23)) && /* MOV CRn/DRn */
             (b != 0xc7),                  /* CMPXCHG{8,16}B */
-            EXC_UD, 0);
+            EXC_UD, -1);
         dst.type = OP_NONE;
         break;
 
     case DstReg:
-        generate_exception_if(lock_prefix, EXC_UD, 0);
+        generate_exception_if(lock_prefix, EXC_UD, -1);
         dst.type = OP_REG;
         if ( d & ByteOp )
         {
@@ -1773,7 +1773,7 @@ x86_emulate(
         dst = ea;
         if ( dst.type == OP_REG )
         {
-            generate_exception_if(lock_prefix, EXC_UD, 0);
+            generate_exception_if(lock_prefix, EXC_UD, -1);
             switch ( dst.bytes )
             {
             case 1: dst.val = *(uint8_t  *)dst.reg; break;
@@ -3785,14 +3785,14 @@ x86_emulate(
         struct segment_register cs = { 0 }, ss = { 0 };
         int rc;
 
-        generate_exception_if(in_realmode(ctxt, ops), EXC_UD, 0);
-        generate_exception_if(!in_protmode(ctxt, ops), EXC_UD, 0);
+        generate_exception_if(in_realmode(ctxt, ops), EXC_UD, -1);
+        generate_exception_if(!in_protmode(ctxt, ops), EXC_UD, -1);
 
         /* Inject #UD if syscall/sysret are disabled. */
         fail_if(ops->read_msr == NULL);
         if ( (rc = ops->read_msr(MSR_EFER, &msr_content, ctxt)) != 0 )
             goto done;
-        generate_exception_if((msr_content & EFER_SCE) == 0, EXC_UD, 0);
+        generate_exception_if((msr_content & EFER_SCE) == 0, EXC_UD, -1);
 
         if ( (rc = ops->read_msr(MSR_STAR, &msr_content, ctxt)) != 0 )
             goto done;