[PATCH] x86/extable: Adjust UD1 encoding in stub_selftest()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

The 0x90 is a ModRM byte and technically needs following by an imm32.

Switch to 0xc0 which encodes two %eax operands, and is a complete instruction.

No practical change.

Reported-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Teddy Astie <teddy.astie@xxxxxxxxxx>
---
 xen/arch/x86/extable.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/extable.c b/xen/arch/x86/extable.c
index a9b6c6b904f5..e1c8c9fab811 100644
--- a/xen/arch/x86/extable.c
+++ b/xen/arch/x86/extable.c
@@ -157,7 +157,7 @@ int __init cf_check stub_selftest(void)
         union stub_exception_token res;
     } tests[] __initconst = {
 #define endbr64 0xf3, 0x0f, 0x1e, 0xfa
-        { .opc = { endbr64, 0x0f, 0xb9, 0x90 }, /* ud1 */
+        { .opc = { endbr64, 0x0f, 0xb9, 0xc0 }, /* ud1 %eax,%eax */
           .res.fields.trapnr = X86_EXC_UD },
         { .opc = { endbr64, 0x90, 0x02, 0x00 }, /* nop; add (%rax),%al */
           .rax = 0x0123456789abcdef,
-- 
2.39.5