From: visa <visa@openbsd.org>
Date: Tue, 6 Jun 2017 14:35:53 +0000 (+0000)
Subject: Implement startup smashing in C. The code should be moved
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=97ee410f21483da75c533fa5dc7e87abc48507bd;p=openbsd

Implement startup smashing in C. The code should be moved
under arch/mips64 once loongson and sgi have gap.o.

Discussed with deraadt@
---

diff --git a/sys/arch/octeon/octeon/autoconf.c b/sys/arch/octeon/octeon/autoconf.c
index eb9fd9bc7d4..0adad7ea22a 100644
--- a/sys/arch/octeon/octeon/autoconf.c
+++ b/sys/arch/octeon/octeon/autoconf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: autoconf.c,v 1.10 2017/04/22 12:34:44 visa Exp $	*/
+/*	$OpenBSD: autoconf.c,v 1.11 2017/06/06 14:35:53 visa Exp $	*/
 /*
  * Copyright (c) 2009 Miodrag Vallat.
  *
@@ -32,6 +32,17 @@ char    bootdev[16];
 enum devclass bootdev_class = DV_DULL;
 extern char uboot_rootdev[];
 
+void
+unmap_startup(void)
+{
+	extern uint32_t kernel_text[], endboot[];
+	uint32_t *word = kernel_text;
+
+	/* Cannot unmap KSEG0; smash with trap. */
+	while (word < endboot)
+		*word++ = 0x00000034u;	/* TEQ zero, zero */
+}
+
 void
 cpu_configure(void)
 {
@@ -40,6 +51,8 @@ cpu_configure(void)
 	softintr_init();
 	(void)config_rootfound("mainbus", NULL);
 
+	unmap_startup();
+
 	splinit();
 	cold = 0;
 }
diff --git a/sys/arch/octeon/octeon/locore.S b/sys/arch/octeon/octeon/locore.S
index 579a2ebce26..1755759df92 100644
--- a/sys/arch/octeon/octeon/locore.S
+++ b/sys/arch/octeon/octeon/locore.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.S,v 1.13 2017/06/05 15:23:11 visa Exp $ */
+/*	$OpenBSD: locore.S,v 1.14 2017/06/06 14:35:53 visa Exp $ */
 
 /*
  * Copyright (c) 2001-2004 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -121,17 +121,6 @@ locore_start:
 	blt	t0, t1, 1b
 	sd	v0, -8(t0)			# store to randomdata
 
-	/*
-	 * Smash the very early boot code by overwriting it.
-	 */
-	li	v0, 0x00000034			# TEQ zero, zero
-	LA	t0, start
-	LA	t1, endboot
-1:
-	daddu	t0, t0, 4
-	blt	t0, t1, 1b
-	sw	v0, -4(t0)
-
 	/*
 	 * Initialize stack and call machine startup.
 	 */