x86/xen: Fix initialisation in hypercall_page after rethunk

The hypercall_page is special and the RETs there should not be changed into rethunk calls (but can have SLS mitigation). Change the initial instructions to ret + int3 padding, as was done in upstream commit 5b2fc51 "x86/ibt,xen: Sprinkle the ENDBR". Signed-off-by: Ben Hutchings <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
openbmc · Jul 23, 2022 · 96907c5 · 96907c5
1 parent 86ccf19
commit 96907c5
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
@@ -69,9 +69,9 @@ SYM_CODE_END(asm_cpu_bringup_and_idle)
 SYM_CODE_START(hypercall_page)
 	.rept (PAGE_SIZE / 32)
 		UNWIND_HINT_FUNC
-		.skip 31, 0x90
 		ANNOTATE_UNRET_SAFE
-		RET
+		ret
+		.skip 31, 0xcc
 	.endr
 
 #define HYPERCALL(n) \