Making a hypercall with the hypercall page absent should not
have a happy ending. At best it's just weird, but at worst it might
allow an otherwise failing test to pass.

Suggested-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Alejandro Vallejo <alejandro.garciavallejo@amd.com>
---
`./xtf-runner -a` passes

v3:
  * New patch based on Roger's suggestion
---
 arch/x86/hypercall_page.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/hypercall_page.S b/arch/x86/hypercall_page.S
index cc6ddc2..de0a991 100644
--- a/arch/x86/hypercall_page.S
+++ b/arch/x86/hypercall_page.S
@@ -6,8 +6,8 @@
         .p2align PAGE_SHIFT
 
 GLOBAL(hypercall_page)
-         /* Poisoned with `ret` for safety before hypercalls are set up. */
-        .fill PAGE_SIZE, 1, 0xc3
+         /* Poisoned with `int3` so a stray hypercall is patently clear */
+        .fill PAGE_SIZE, 1, 0xcc
         .type hypercall_page, STT_OBJECT
         .size hypercall_page, PAGE_SIZE
 
-- 
2.43.0