libexec/ld.elf_so/hash.c

1.1.6.2  sborrill /*	$NetBSD: hash.c,v 1.1.6.2 2023/08/11 12:13:10 sborrill Exp $	 */
1.1.6.2  sborrill
1.1.6.2  sborrill /*
1.1.6.2  sborrill  * Copyright 1996 John D. Polstra.
1.1.6.2  sborrill  * Copyright 1996 Matt Thomas <matt (at) 3am-software.com>
1.1.6.2  sborrill  * Copyright 2002 Charles M. Hannum <root (at) ihack.net>
1.1.6.2  sborrill  * All rights reserved.
1.1.6.2  sborrill  *
1.1.6.2  sborrill  * Redistribution and use in source and binary forms, with or without
1.1.6.2  sborrill  * modification, are permitted provided that the following conditions
1.1.6.2  sborrill  * are met:
1.1.6.2  sborrill  * 1. Redistributions of source code must retain the above copyright
1.1.6.2  sborrill  *    notice, this list of conditions and the following disclaimer.
1.1.6.2  sborrill  * 2. Redistributions in binary form must reproduce the above copyright
1.1.6.2  sborrill  *    notice, this list of conditions and the following disclaimer in the
1.1.6.2  sborrill  *    documentation and/or other materials provided with the distribution.
1.1.6.2  sborrill  * 3. All advertising materials mentioning features or use of this software
1.1.6.2  sborrill  *    must display the following acknowledgement:
1.1.6.2  sborrill  *      This product includes software developed by John Polstra.
1.1.6.2  sborrill  * 4. The name of the author may not be used to endorse or promote products
1.1.6.2  sborrill  *    derived from this software without specific prior written permission.
1.1.6.2  sborrill  *
1.1.6.2  sborrill  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
1.1.6.2  sborrill  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
1.1.6.2  sborrill  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
1.1.6.2  sborrill  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
1.1.6.2  sborrill  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
1.1.6.2  sborrill  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.1.6.2  sborrill  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.1.6.2  sborrill  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.1.6.2  sborrill  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1.1.6.2  sborrill  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.1.6.2  sborrill  */
1.1.6.2  sborrill
1.1.6.2  sborrill /*
1.1.6.2  sborrill  * Dynamic linker for ELF.
1.1.6.2  sborrill  *
1.1.6.2  sborrill  * John Polstra <jdp (at) polstra.com>.
1.1.6.2  sborrill  */
1.1.6.2  sborrill
1.1.6.2  sborrill #include <sys/cdefs.h>
1.1.6.2  sborrill #ifndef lint
1.1.6.2  sborrill __RCSID("$NetBSD: hash.c,v 1.1.6.2 2023/08/11 12:13:10 sborrill Exp $");
1.1.6.2  sborrill #endif /* not lint */
1.1.6.2  sborrill
1.1.6.2  sborrill #include <stdint.h>
1.1.6.2  sborrill
1.1.6.2  sborrill #include "hash.h"
1.1.6.2  sborrill
1.1.6.2  sborrill /*
1.1.6.2  sborrill  * SysV hash function for symbol table lookup.  It is a slightly optimized
1.1.6.2  sborrill  * version of the hash specified by the System V ABI.
1.1.6.2  sborrill  */
1.1.6.2  sborrill Elf32_Word
1.1.6.2  sborrill _rtld_elf_hash(const char *name)
1.1.6.2  sborrill {
1.1.6.2  sborrill 	const unsigned char *p = (const unsigned char *) name;
1.1.6.2  sborrill 	Elf32_Word h = 0;
1.1.6.2  sborrill
1.1.6.2  sborrill 	while (__predict_true(*p != '\0')) {
1.1.6.2  sborrill 		h = (h << 4) + *p++;
1.1.6.2  sborrill 		h ^= (h >> 24) & 0xf0;
1.1.6.2  sborrill 	}
1.1.6.2  sborrill 	return (h & 0x0fffffff);
1.1.6.2  sborrill }