Make sure copyoutstr() invoked with a length of zero returns ENAMETOOLONG.

This bug has been present in that file since the very beginning, more than
28 years ago.

diff --git a/sys/arch/m88k/m88k/subr.S b/sys/arch/m88k/m88k/subr.S
index ff73eec..b930841 100644 (file)
--- a/sys/arch/m88k/m88k/subr.S
+++ b/sys/arch/m88k/m88k/subr.S
@@ -1,4 +1,4 @@
-/* $OpenBSD: subr.S,v 1.31 2023/12/12 07:37:21 deraadt Exp $   */
+/* $OpenBSD: subr.S,v 1.32 2024/03/08 16:18:53 miod Exp $      */
 /*
  * Mach Operating System
  * Copyright (c) 1993-1992 Carnegie Mellon University
@@ -714,7 +714,7 @@ ENTRY(copyoutstr)
        or      %r6,  %r6,  %lo16(Lcosflt)
        st      %r6,  %r7,  PCB_ONFAULT
        bcnd    lt0,  CNT,  Lcosflt
-       bcnd    eq0,  CNT,  Lcosdone
+       bcnd    eq0,  CNT,  2f
        or      %r6,  %r0,  0
 1:
        ld.bu   %r7,  SRC,  %r6
@@ -727,13 +727,14 @@ ENTRY(copyoutstr)
 #else
        st.b.usr        %r7,  DEST,  %r6
 #endif
-       bcnd.n  eq0,  %r7, 2f           /* all done */
+       bcnd.n  eq0,  %r7, 3f           /* all done */
         addu   %r6,  %r6, 1
        cmp     %r7,  %r6, CNT
        bb1     lt,   %r7, 1b
+2:
        br.n    Lcosdone
         or     %r2,  %r0, ENAMETOOLONG
-2:
+3:
        br.n    Lcosdone
         or     %r2,  %r0, 0