From f5edbdc5910a35966903868133ff9b8c9e7e8353 Mon Sep 17 00:00:00 2001
From: guenther <guenther@openbsd.org>
Date: Sun, 16 Apr 2023 06:38:50 +0000
Subject: [PATCH] Handle T_CP traps from userland by generating SIGILL, with
 code ILL_ILLOPC or ILL_BADSTK depending on the error from hardware

lack of handling noted by deraadt@
ok jsg@
---
 sys/arch/amd64/amd64/trap.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sys/arch/amd64/amd64/trap.c b/sys/arch/amd64/amd64/trap.c
index 783184b2b17..8c9abf64bd7 100644
--- a/sys/arch/amd64/amd64/trap.c
+++ b/sys/arch/amd64/amd64/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.98 2023/04/15 01:22:50 jsg Exp $	*/
+/*	$OpenBSD: trap.c,v 1.99 2023/04/16 06:38:50 guenther Exp $	*/
 /*	$NetBSD: trap.c,v 1.2 2003/05/04 23:51:56 fvdl Exp $	*/
 
 /*-
@@ -431,6 +431,11 @@ usertrap(struct trapframe *frame)
 		sig = SIGTRAP;
 		code = TRAP_BRKPT;
 		break;
+	case T_CP:
+		sig = SIGILL;
+		code = (frame->tf_err & 0x7fff) < 4 ? ILL_ILLOPC
+		    : ILL_BADSTK;
+		break;
 
 	case T_PAGEFLT:			/* page fault */
 		if (!uvm_map_inentry(p, &p->p_spinentry, PROC_STACK(p),
-- 
2.20.1