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

src/lib/libc/string/Makefile.inc

@@ -1,11 +1,11 @@
-#	$OpenBSD: Makefile.inc,v 1.35 2014/06/13 02:12:17 matthew Exp $
+#	$OpenBSD: Makefile.inc,v 1.36 2014/11/30 19:43:56 deraadt Exp $
 
 # string sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_CPU}/string ${LIBCSRCDIR}/string
 
 SRCS+=	explicit_bzero.c memccpy.c memmem.c memrchr.c stpcpy.c stpncpy.c \
 	strcasecmp.c strcasestr.c strcoll.c strdup.c \
-	strerror.c strerror_r.c strlcat.c strmode.c strndup.c strnlen.c \
+	strerror.c strerror_r.c strmode.c strndup.c strnlen.c \
 	strsignal.c strtok.c strxfrm.c \
 	timingsafe_bcmp.c timingsafe_memcmp.c \
 	wcscat.c wcschr.c wcscmp.c wcscpy.c wcscspn.c wcslcat.c wcslcpy.c \
@@ -14,136 +14,15 @@ SRCS+=	explicit_bzero.c memccpy.c memmem.c memrchr.c stpcpy.c stpncpy.c \
 	wmemmove.c wmemset.c wcsdup.c wcscasecmp.c
 
 # machine-dependent net sources
-# m-d Makefile.inc must include sources for:
+# ../arch/ARCH/Makefile.inc must include sources for:
 #	bcmp() bcopy() bzero() ffs() index() memchr() memcmp() memset()
-#	rindex() strcat() strcmp() strcpy() strcspn() strlen() strlcpy()
-#	strncat() strncmp() strncpy() strpbrk() strsep()
-#	strspn() strstr() swav()
-# m-d Makefile.inc may include sources for:
-#	memcpy() memmove() strchr() strrchr()
+#	memcpy() memmove() memset() rindex() strcat() strchr()
+#	strcmp() strcpy() strcspn() strlen() strlcat() strlcpy()
+#	strncat() strncmp() strncpy() strpbrk() strrchr() strsep()
+#	strspn() strstr() swab()
 
 .include "${LIBCSRCDIR}/arch/${MACHINE_CPU}/string/Makefile.inc"
 
-# if no machine specific memmove(3), build one out of bcopy(3).
-.if empty(SRCS:Mmemmove.S)
-OBJS+=	memmove.o
-memmove.o: bcopy.c
-	${CC} -DMEMMOVE ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-memmove.go: bcopy.c
-	${CC} -g -DMEMMOVE ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-memmove.po: bcopy.c
-	${CC} -DMEMMOVE ${CFLAGS} ${CPPFLAGS} -c -p ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -X -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-memmove.so: bcopy.c
-	${CC} ${PICFLAG} -DPIC -DMEMMOVE ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} \
-		-o ${.TARGET}
-
-memmove.do: bcopy.c
-	${CC} -DMEMMOVE ${CFLAGS} ${CPPFLAGS} ${DIST_CFLAGS} -c ${.ALLSRC} \
-	    -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-.endif
-
-# if no machine specific memcpy(3), build one out of bcopy(3).
-# if there is a machine specific memmove(3), we'll assume it aliases
-# memcpy(3).
-.if empty(SRCS:Mmemcpy.S)
-.if empty(SRCS:Mmemmove.S)
-OBJS+=	memcpy.o
-memcpy.o: bcopy.c
-	${CC} -DMEMCOPY ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-memcpy.go: bcopy.c
-	${CC} -g -DMEMCOPY ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-memcpy.po: bcopy.c
-	${CC} -DMEMCOPY ${CFLAGS} ${CPPFLAGS} -c -p ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -X -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-memcpy.so: bcopy.c
-	${CC} ${PICFLAG} -DPIC -DMEMCOPY ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} \
-		-o ${.TARGET}
-
-memcpy.do: bcopy.c
-	${CC} -DMEMCOPY ${CFLAGS} ${CPPFLAGS} ${DIST_CFLAGS} -c ${.ALLSRC} \
-	    -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-.endif
-.endif
-
-# if no machine specific strchr(3), build one out of index(3).
-.if empty(SRCS:Mstrchr.S)
-OBJS+=	strchr.o
-strchr.o: index.c
-	${CC} -DSTRCHR ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-strchr.go: index.c
-	${CC} -g -DSTRCHR ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-strchr.po: index.c
-	${CC} -DSTRCHR ${CFLAGS} ${CPPFLAGS} -c -p ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -X -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-strchr.so: index.c
-	${CC} ${PICFLAG} -DPIC -DSTRCHR ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} \
-	    -o ${.TARGET}
-
-strchr.do: index.c
-	${CC} -DSTRCHR ${CFLAGS} ${CPPFLAGS} ${DIST_CFLAGS} -c ${.ALLSRC} \
-	    -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-.endif
-
-# if no machine specific strrchr(3), build one out of rindex(3).
-.if empty(SRCS:Mstrrchr.S)
-OBJS+=	strrchr.o
-strrchr.o: rindex.c
-	${CC} -DSTRRCHR ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-strrchr.go: rindex.c
-	${CC} -g -DSTRRCHR ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-strrchr.po: rindex.c
-	${CC} -DSTRRCHR ${CFLAGS} ${CPPFLAGS} -c -p ${.ALLSRC} -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -X -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-
-strrchr.so: rindex.c
-	${CC} ${PICFLAG} -DPIC -DSTRRCHR ${CFLAGS} ${CPPFLAGS} -c ${.ALLSRC} \
-	    -o ${.TARGET}
-
-strrchr.do: rindex.c
-	${CC} -DSTRRCHR ${CFLAGS} ${CPPFLAGS} ${DIST_CFLAGS} -c ${.ALLSRC} \
-	    -o ${.TARGET}
-	@${LD} -o ${.TARGET}.tmp -x -r ${.TARGET}
-	@mv ${.TARGET}.tmp ${.TARGET}
-.endif
-
 MAN+=	bcmp.3 bcopy.3 bstring.3 bzero.3 ffs.3 memccpy.3 memchr.3 \
 	memcmp.3 memcpy.3 memmem.3 memmove.3 memset.3 stpcpy.3 strcasecmp.3 \
 	strcat.3 strchr.3 strcmp.3 strcoll.3 strcpy.3 strcspn.3 strdup.3 \

src/lib/libc/string/bcopy.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: bcopy.c,v 1.5 2005/08/08 08:05:37 espie Exp $ */
+/*	$OpenBSD: bcopy.c,v 1.6 2014/11/30 19:43:56 deraadt Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -44,21 +44,9 @@ typedef	long word;		/* "word" used for optimal copy speed */
 
 /*
  * Copy a block of memory, handling overlap.
- * This is the routine that actually implements
- * (the portable versions of) bcopy, memcpy, and memmove.
  */
-#ifdef MEMCOPY
-void *
-memcpy(void *dst0, const void *src0, size_t length)
-#else
-#ifdef MEMMOVE
-void *
-memmove(void *dst0, const void *src0, size_t length)
-#else
 void
 bcopy(const void *src0, void *dst0, size_t length)
-#endif
-#endif
 {
 	char *dst = dst0;
 	const char *src = src0;
@@ -120,9 +108,5 @@ bcopy(const void *src0, void *dst0, size_t length)
 		TLOOP(*--dst = *--src);
 	}
 done:
-#if defined(MEMCOPY) || defined(MEMMOVE)
-	return (dst0);
-#else
 	return;
-#endif
 }

src/lib/libc/string/index.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: index.c,v 1.5 2005/08/08 08:05:37 espie Exp $ */
+/*	$OpenBSD: index.c,v 1.6 2014/11/30 19:43:56 deraadt Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -31,11 +31,7 @@
 #include <string.h>
 
 char *
-#ifdef STRCHR
-strchr(const char *p, int ch)
-#else
 index(const char *p, int ch)
-#endif
 {
 	for (;; ++p) {
 		if (*p == ch)

src/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);
+}

src/lib/libc/string/memmove.c

@@ -0,0 +1,112 @@
+/*	$OpenBSD: memmove.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>
+
+/*
+ * 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, handling overlap.
+ */
+void *
+memmove(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;
+
+	/*
+	 * Macros: loop-t-times; and loop-t-times, t>0
+	 */
+#define	TLOOP(s) if (t) TLOOP1(s)
+#define	TLOOP1(s) do { s; } while (--t)
+
+	if ((unsigned long)dst < (unsigned long)src) {
+		/*
+		 * 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++);
+	} else {
+		/*
+		 * Copy backwards.  Otherwise essentially the same.
+		 * Alignment works as before, except that it takes
+		 * (t&wmask) bytes to align, not wsize-(t&wmask).
+		 */
+		src += length;
+		dst += length;
+		t = (long)src;
+		if ((t | (long)dst) & wmask) {
+			if ((t ^ (long)dst) & wmask || length <= wsize)
+				t = length;
+			else
+				t &= wmask;
+			length -= t;
+			TLOOP1(*--dst = *--src);
+		}
+		t = length / wsize;
+		TLOOP(src -= wsize; dst -= wsize; *(word *)dst = *(word *)src);
+		t = length & wmask;
+		TLOOP(*--dst = *--src);
+	}
+done:
+	return (dst0);
+}

src/lib/libc/string/rindex.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: rindex.c,v 1.6 2005/08/08 08:05:37 espie Exp $ */
+/*	$OpenBSD: rindex.c,v 1.7 2014/11/30 19:43:56 deraadt Exp $ */
 /*
  * Copyright (c) 1988 Regents of the University of California.
  * All rights reserved.
@@ -31,11 +31,7 @@
 #include <string.h>
 
 char *
-#ifdef STRRCHR
-strrchr(const char *p, int ch)
-#else
 rindex(const char *p, int ch)
-#endif
 {
 	char *save;
 

src/lib/libc/string/strchr.c

@@ -0,0 +1,43 @@
+/*	$OpenBSD: strchr.c,v 1.1 2014/11/30 19:43:57 deraadt Exp $ */
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * 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>
+
+char *
+strchr(const char *p, int ch)
+{
+	for (;; ++p) {
+		if (*p == ch)
+			return((char *)p);
+		if (!*p)
+			return((char *)NULL);
+	}
+	/* NOTREACHED */
+}

src/lib/libc/string/strrchr.c

@@ -0,0 +1,45 @@
+/*	$OpenBSD: strrchr.c,v 1.1 2014/11/30 19:43:57 deraadt Exp $ */
+/*
+ * Copyright (c) 1988 Regents of the University of California.
+ * All rights reserved.
+ *
+ * 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>
+
+char *
+strrchr(const char *p, int ch)
+{
+	char *save;
+
+	for (save = NULL;; ++p) {
+		if (*p == ch)
+			save = (char *)p;
+		if (!*p)
+			return(save);
+	}
+	/* NOTREACHED */
+}