[Xen-devel] [PATCH] x86: emulate lea with two register operands correctly

[David Vrabel <david.vrabel@xxxxxxxxxx>]

An lea instruction with two register operands should raise an
undefined instruction exception.

Skype does such a instruction and will crash when starting if it does
not get the exception.

Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>

diff -r efaa28639a71 -r e25b7798f13b xen/arch/x86/x86_emulate/x86_emulate.c
--- a/xen/arch/x86/x86_emulate/x86_emulate.c    Wed Jan 04 16:12:44 2012 +0000
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c    Thu Jan 05 14:58:56 2012 +0000
@@ -2240,6 +2240,7 @@ x86_emulate(
     }
 
     case 0x8d: /* lea */
+        generate_exception_if(modrm_mod == 3, EXC_UD, -1);
         dst.val = ea.mem.off;
         break;
 

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