From: miod <miod@openbsd.org>
Date: Mon, 20 Nov 2023 16:10:37 +0000 (+0000)
Subject: Make sure the low two bits of stvec are always zero (since we don't use
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=f03cce2a7dce1ef3e80716902f3eadde9117ad73;p=openbsd

Make sure the low two bits of stvec are always zero (since we don't use
vectored exceptions) by adding an alignment constraint to cpu_exception_handler.
---

diff --git a/sys/arch/riscv64/riscv64/exception.S b/sys/arch/riscv64/riscv64/exception.S
index 1fe16a33c4d..c9eb9b3467c 100644
--- a/sys/arch/riscv64/riscv64/exception.S
+++ b/sys/arch/riscv64/riscv64/exception.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: exception.S,v 1.6 2022/12/02 12:27:08 jca Exp $	*/
+/*	$OpenBSD: exception.S,v 1.7 2023/11/20 16:10:37 miod Exp $	*/
 
 /*-
  * Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com>
@@ -208,6 +208,12 @@
 2:
 .endm
 
+	/*
+	 * cpu_exception_handler needs to be aligned to a 32-bit
+	 * boundary, but ENTRY() only enforces 16-bit alignment.
+	 */
+	.text
+	.p2align 2
 ENTRY(cpu_exception_handler)
 	csrrw	sp, sscratch, sp
 	beqz	sp, 1f