--- cci/sys/tahoe/machdep.c	2019/07/28 12:24:19	1.1.1.1
+++ cci/sys/tahoe/machdep.c	2019/07/28 12:30:04	1.1.1.2
@@ -308,7 +308,9 @@ sendsig(p, sig, sigmask)
 		grow((unsigned)fp);
 	;
 #ifndef lint
-	asm("probew $1,(r10),$7*4");
+	asm("probew $1,(r10),$1");
+	asm("jeql bad");
+	asm("probew $1,7*4-1(r10),$1");
 	asm("jeql bad");
 #else
 	if (useracc((caddr_t)fp, sizeof (struct sigframe), 1))
@@ -318,7 +320,9 @@ sendsig(p, sig, sigmask)
 		grow((unsigned)scp);
 	;			/* Avoid asm() label botch */
 #ifndef lint
-	asm("probew $1,(r12),$5*4");
+	asm("probew $1,(r12),$1");
+	asm("beql bad");
+	asm("probew $1,5*4-1(r12),$1");
 	asm("beql bad");
 #else
 	if (useracc((caddr_t)scp, sizeof (struct sigcontext), 1))
@@ -382,8 +386,10 @@ sigcleanup()
 #ifndef lint
 	;			/* Avoid asm() label botch */
 	/* only probe 12 here because that's all we need */
-	asm("prober $1,(r12),$12");
+	asm("prober $1,(r12),$1");
 	asm("bnequ 1f; ret; 1:");
+	asm("prober $1,11(r12),$1");
+	asm("bnequ 2f; ret; 2:");
 #else
 	if (useracc((caddr_t)scp, sizeof (*scp), 0))
 		return;