HardenedBSD/gnu/usr.bin/ld/rtld/sbrk.c
Peter Wemm 5584286a91 Update to handle new version ld.so.hints and info in executable for
configurable fallback search paths, as well as new crt interface version.

Also:
 - even faster getenv(), get all environment variable settings in a single
   pass.
 - ldd printf-like format specifications
 - minor code cleanups, one vsprintf -> vsnprintf (harmless)

The library search sequence is a little more complete now. Before,
it'd search $LD_LIBRARY_PATH (by opendir/readdir/closedir), then read
the hints file, then read /usr/lib (again by scanning thr directory).  It
would then fail if there was no "found" library.

Now, it does LD_LIBRARY_PATH and the hints file the same, but then uses
a longer fallback path.  The -R path is fetched from the executable if
specified at build time, the ldconfig path is appended, and /usr/lib is
appended to that. Duplicates are suppressed.  This means that simply
placing a new library in /usr/local/lib will work (the same as it did in
/usr/lib) without needing ldconfig -m.  It will find it quicker if the
ldconfig is run though.

Similar changes have been made to the NetBSD ld.so, but ours is rather
different now due to John Polstra's speedups and fixes from a while back.

The ldd printf-like format support came direct from NetBSD.

Reviewed by: nate, jdp
1996-10-01 01:52:03 +00:00

102 lines
2.8 KiB
C

/*
* Copyright (c) 1993 Paul Kranenburg
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Paul Kranenburg.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software withough specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* $Id: sbrk.c,v 1.1 1993/12/11 21:06:36 jkh Exp $
*/
#include <machine/vmparam.h>
#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/mman.h>
#ifndef BSD
#define MAP_COPY MAP_PRIVATE
#define MAP_FILE 0
#define MAP_ANON 0
#endif
#include <fcntl.h>
#include <a.out.h>
#include <stab.h>
#include <string.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include <machine/param.h>
#ifndef BSD /* Need do better than this */
#define NEED_DEV_ZERO 1
#endif
caddr_t
sbrk(incr)
int incr;
{
int fd = -1;
caddr_t curbrk;
/* Round-up increment to page size */
incr = ((incr + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1));
#if DEBUG
xprintf("sbrk: incr = %#x\n", incr);
#endif
#ifdef NEED_DEV_ZERO
fd = open("/dev/zero", O_RDWR, 0);
if (fd == -1)
perror("/dev/zero");
#endif
if ((curbrk = mmap(0, incr,
PROT_READ|PROT_WRITE,
MAP_ANON|MAP_COPY, fd, 0)) == (caddr_t)-1) {
xprintf("Cannot map anonymous memory");
_exit(1);
}
#ifdef DEBUG
xprintf("sbrk: curbrk = %#x\n", curbrk);
#endif
#ifdef NEED_DEV_ZERO
close(fd);
#endif
return(curbrk);
}