[src/trunk]: src/lib/libc memcpy/memmove/bcopy: Add diagnostic code to check ...

[kent <kent%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1afa8dc5d6af
branches:  trunk
changeset: 533579:1afa8dc5d6af
user:      kent <kent%NetBSD.org@localhost>
date:      Thu Jul 04 15:48:40 2002 +0000

description:
memcpy/memmove/bcopy: Add diagnostic code to check pointer wraparound.
The code is enabled only when _DIAGNOSTIC is defined.

diffstat:

 lib/libc/arch/i386/string/bcopy.S |  43 ++++++++++++++++++++++++++++++++++++++-
 lib/libc/string/bcopy.c           |   6 +++-
 2 files changed, 46 insertions(+), 3 deletions(-)

diffs (98 lines):

diff -r 6fd9b8a4f16c -r 1afa8dc5d6af lib/libc/arch/i386/string/bcopy.S
--- a/lib/libc/arch/i386/string/bcopy.S Thu Jul 04 14:37:10 2002 +0000
+++ b/lib/libc/arch/i386/string/bcopy.S Thu Jul 04 15:48:40 2002 +0000
@@ -36,7 +36,7 @@
 #include <machine/asm.h>
 
 #if defined(LIBC_SCCS)
-       RCSID("$NetBSD: bcopy.S,v 1.6 1996/11/12 00:50:06 jtc Exp $")
+       RCSID("$NetBSD: bcopy.S,v 1.7 2002/07/04 15:48:40 kent Exp $")
 #endif
 
        /*
@@ -84,6 +84,29 @@
 1:
        addl    %ecx,%edi       /* copy backwards. */
        addl    %ecx,%esi
+#ifdef _DIAGNOSTIC
+#define _DIAGASSERT    call    _C_LABEL(__diagassert13)
+       cmpl    12(%esp),%edi   /* check pointer wraparound */
+       jae     2f
+       pushl   $diagmes1
+       pushl   $func
+       pushl   $__LINE__-4
+       pushl   $file
+       _DIAGASSERT
+       addl    $16,%esp
+       jmp     4f
+2:     
+       cmpl    16(%esp),%esi
+       jae     3f
+       pushl   $diagmes2
+       pushl   $func
+       pushl   $__LINE__-4
+       pushl   $file
+       _DIAGASSERT
+       addl    $16,%esp
+       jmp     4f
+3:
+#endif
        std
        andl    $3,%ecx         /* any fractional bytes? */
        decl    %edi
@@ -96,6 +119,7 @@
        subl    $3,%edi
        rep
        movsl
+4:
 #if defined(MEMCOPY) || defined(MEMMOVE)
        movl    12(%esp),%eax
 #endif
@@ -103,3 +127,20 @@
        popl    %esi
        cld
        ret
+
+#ifdef _DIAGNOSTIC
+file:
+       .asciz  __FILE__
+func:
+#if defined(MEMCOPY)
+       .asciz  "memcpy"
+#elseif defined(MEMMOVE)
+       .asciz  "memmove"
+#else
+       .asciz  "bcopy"
+#endif
+diagmes1:
+       .asciz  "src + length > src"
+diagmes2:
+       .asciz  "dst + length > dst"
+#endif /* _DIAGNOSTIC */
diff -r 6fd9b8a4f16c -r 1afa8dc5d6af lib/libc/string/bcopy.c
--- a/lib/libc/string/bcopy.c   Thu Jul 04 14:37:10 2002 +0000
+++ b/lib/libc/string/bcopy.c   Thu Jul 04 15:48:40 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: bcopy.c,v 1.13 2001/02/08 18:33:50 wiz Exp $   */
+/*     $NetBSD: bcopy.c,v 1.14 2002/07/04 15:48:41 kent Exp $  */
 
 /*-
  * Copyright (c) 1990, 1993
@@ -41,7 +41,7 @@
 #if 0
 static char sccsid[] = "@(#)bcopy.c    8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: bcopy.c,v 1.13 2001/02/08 18:33:50 wiz Exp $");
+__RCSID("$NetBSD: bcopy.c,v 1.14 2002/07/04 15:48:41 kent Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -132,6 +132,8 @@
                 */
                src += length;
                dst += length;
+               _DIAGASSERT((unsigned long)dst >= (unsigned long)dst0);
+               _DIAGASSERT((unsigned long)src >= (unsigned long)src0);
                u = (unsigned long)src;
                if ((u | (unsigned long)dst) & wmask) {
                        if ((u ^ (unsigned long)dst) & wmask || length <= wsize)