ssp: add Object Size Checking for strings.h

The implementation is from NetBSD, with the addition of explicit_bzero
for parity with glibc.

Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>

newlib/libc/include/ssp/strings.h

@@ -0,0 +1,55 @@
+/*	$NetBSD: strings.h,v 1.3 2008/04/28 20:22:54 martin Exp $	*/
+
+/*-
+ * Copyright (c) 2007 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Christos Zoulas.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _SSP_STRINGS_H_
+#define _SSP_STRINGS_H_
+
+#include <ssp/ssp.h>
+
+#if __SSP_FORTIFY_LEVEL > 0
+
+#if __BSD_VISIBLE || __POSIX_VISIBLE <= 200112
+#define bcopy(src, dst, len) \
+    ((__ssp_bos0(dst) != (size_t)-1) ? \
+    __builtin___memmove_chk(dst, src, len, __ssp_bos0(dst)) : \
+    __memmove_ichk(dst, src, len))
+#define bzero(dst, len) \
+    ((__ssp_bos0(dst) != (size_t)-1) ? \
+    __builtin___memset_chk(dst, 0, len, __ssp_bos0(dst)) : \
+    __memset_ichk(dst, 0, len))
+#endif
+
+#if __BSD_VISIBLE
+__ssp_redirect0(void, explicit_bzero, (void *__buf, size_t __len), \
+    (__buf, __len));
+#endif
+
+#endif /* __SSP_FORTIFY_LEVEL > 0 */
+#endif /* _SSP_STRINGS_H_ */

newlib/libc/include/strings.h

@@ -73,4 +73,8 @@ int	 strncasecmp_l (const char *, const char *, size_t, locale_t);
 #endif
 __END_DECLS
 
+#if __SSP_FORTIFY_LEVEL > 0
+#include <ssp/strings.h>
+#endif
+
 #endif /* _STRINGS_H_ */