restructure libc/string + libc/arch/*/string coperation regarding

(potentially) MD versions (function dependent, not filename dependent)
split out memcpy/memmove/bcopy and strchr/index/strrchr/rindex
Bring back amd64 .S versions

And the final touch: switch all architectures temporarily to MI
memcpy.c, which contains syslog + abort for overlapping copies.  A nice
harsh undefined behaviour.  We will clean the entire userland of the
remaining issues in this catagory, then switch to the optimised memcpy
which skips the memmove check.

I tried to cut this change into pieces, but testing each sub-step on
every architecture is too time consuming and mindnumbing.
ok miod

1 files changed, 99 insertions, 0 deletions

diff --git a/lib/libc/string/memcpy.c b/lib/libc/string/memcpy.c
new file mode 100644
index 00000000000..1b9715e4717
--- /dev/null
+++ b/lib/libc/string/memcpy.c
@@ -0,0 +1,99 @@
+/*	$OpenBSD: memcpy.c,v 1.1 2014/11/30 19:43:56 deraadt Exp $ */
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * 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.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <syslog.h>
+
+/*
+ * sizeof(word) MUST BE A POWER OF TWO
+ * SO THAT wmask BELOW IS ALL ONES
+ */
+typedef	long word;		/* "word" used for optimal copy speed */
+
+#define	wsize	sizeof(word)
+#define	wmask	(wsize - 1)
+
+/*
+ * Copy a block of memory, not handling overlap.
+ */
+void *
+memcpy(void *dst0, const void *src0, size_t length)
+{
+	char *dst = dst0;
+	const char *src = src0;
+	size_t t;
+
+	if (length == 0 || dst == src)		/* nothing to do */
+		goto done;
+
+	if ((dst < src && dst + length > src) ||
+	    (src < dst && src + length > dst)) {
+		struct syslog_data sdata = SYSLOG_DATA_INIT;
+
+		syslog_r(LOG_CRIT, &sdata, "backwards memcpy");
+		abort();
+	}
+
+	/*
+	 * Macros: loop-t-times; and loop-t-times, t>0
+	 */
+#define	TLOOP(s) if (t) TLOOP1(s)
+#define	TLOOP1(s) do { s; } while (--t)
+
+	/*
+	 * Copy forward.
+	 */
+	t = (long)src;	/* only need low bits */
+	if ((t | (long)dst) & wmask) {
+		/*
+		 * Try to align operands.  This cannot be done
+		 * unless the low bits match.
+		 */
+		if ((t ^ (long)dst) & wmask || length < wsize)
+			t = length;
+		else
+			t = wsize - (t & wmask);
+		length -= t;
+		TLOOP1(*dst++ = *src++);
+	}
+	/*
+	 * Copy whole words, then mop up any trailing bytes.
+	 */
+	t = length / wsize;
+	TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize);
+	t = length & wmask;
+	TLOOP(*dst++ = *src++);
+done:
+	return (dst0);
+}