careful mmap

2 files changed, 4 insertions, 4 deletions

diff --git a/sys/arch/mac68k/dev/asc.c b/sys/arch/mac68k/dev/asc.c
index e28c325f1d7..5cd6ce22626 100644
--- a/sys/arch/mac68k/dev/asc.c
+++ b/sys/arch/mac68k/dev/asc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: asc.c,v 1.7 1998/04/27 02:04:32 gene Exp $	*/
+/*	$OpenBSD: asc.c,v 1.8 1998/11/20 23:57:24 deraadt Exp $	*/
 /*	$NetBSD: asc.c,v 1.20 1997/02/24 05:47:33 scottr Exp $	*/
 
 /*
@@ -281,7 +281,7 @@ ascmmap(dev, off, prot)
 	vm_offset_t pa;
 
 	sc = asc_cd.cd_devs[unit];
-	if (off < MAC68K_ASC_LEN) {
+	if (off >= 0 && off < MAC68K_ASC_LEN) {
 		pa = pmap_extract(pmap_kernel(), (vm_offset_t)sc->sc_handle);
 		return mac68k_btop(pa + off);
 	}
diff --git a/sys/arch/mac68k/dev/grf.c b/sys/arch/mac68k/dev/grf.c
index 8e86c877e1f..694423e145d 100644
--- a/sys/arch/mac68k/dev/grf.c
+++ b/sys/arch/mac68k/dev/grf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: grf.c,v 1.7 1997/03/12 13:36:57 briggs Exp $	*/
+/*	$OpenBSD: grf.c,v 1.8 1998/11/20 23:57:24 deraadt Exp $	*/
 /*	$NetBSD: grf.c,v 1.41 1997/02/24 06:20:04 scottr Exp $	*/
 
 /*
@@ -331,7 +331,7 @@ grfaddr(gp, off)
 	register struct grfmode *gm = gp->sc_grfmode;
 	u_long	addr;
 
-	if (off < mac68k_round_page(gm->fbsize + gm->fboff)) {
+	if (off >= 0 && off < mac68k_round_page(gm->fbsize + gm->fboff)) {
 		addr = (u_long)(*gp->sc_phys)(gp, (vm_offset_t)gm->fbbase)+off;
 		return mac68k_btop(addr);
 	}