UBUNTU: SAUCE: x86/kvm: Fix stuff_RSB() for 32-bit

CVE-2017-5753
CVE-2017-5715
Signed-off-by: William Grant <wgrant@ubuntu.com>
Acked-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>

arch/x86/include/asm/kvm_host.h

@@ -194,9 +194,13 @@ static inline void stuff_RSB(void)
 .label31:	\n\
 	call .label32	\n\
 	pause	\n\
-.label32: \n\
-	add $(32*8), %%rsp 	\n\
-": : :"memory");
+.label32: \n"
+#ifdef CONFIG_X86_64
+" 	add $(32*8), %%rsp 	\n"
+#else
+" 	add $(32*4), %%esp 	\n"
+#endif
+: : :"memory");
 }
 
 enum kvm_reg {