NetBSD/usr.bin/ldd/ldd_elf/ldd.c
skrll d900731978 Resolve dlsym(3) and friends directly so that dlsym(RTLD_NEXT,...) works.
Previously dlsym resolved to the version in crt0.o or libc which would
mean that the caller's shared object couldn't be determined correctly
using __builtin_return_address(0).

Mainly from FreeBSD, but adapted by me. Benefits of this solutions are:

	- backward comptibility maintained
	- existing broken binaries are fixed with a new ld.elf_so
	- __mainprog_obj can be removed from crt0.o
	- we do the same thing as FreeBSD

Fixes PR 22067.

OKed by Jason and Christos.
2003-08-12 09:18:38 +00:00

284 lines
8.3 KiB
C

/* $NetBSD: ldd.c,v 1.20 2003/08/12 09:18:38 skrll Exp $ */
/*-
* Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Paul Kranenburg.
*
* 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 the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 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.
*/
/*
* Copyright 1996 John D. Polstra.
* Copyright 1996 Matt Thomas <matt@3am-software.com>
* 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 John Polstra.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without 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.
*/
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <a.out.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "debug.h"
#include "rtld.h"
/*
* Data declarations.
*/
static char *error_message; /* Message for dlopen(), or NULL */
bool _rtld_trust; /* False for setuid and setgid programs */
Obj_Entry *_rtld_objlist; /* Head of linked list of shared objects */
Obj_Entry **_rtld_objtail = &_rtld_objlist;
/* Link field of last object in list */
Obj_Entry *_rtld_objmain; /* The main program shared object */
int _rtld_pagesz;
Search_Path *_rtld_default_paths;
Search_Path *_rtld_paths;
Library_Xform *_rtld_xforms;
static void print_needed(Obj_Entry *);
static int ldd_aout(char *, int);
int
main(int argc, char **argv)
{
struct stat st;
#ifdef DEBUG
debug = 1;
#endif
_rtld_add_paths(&_rtld_default_paths, RTLD_DEFAULT_LIBRARY_PATH);
_rtld_pagesz = sysconf(_SC_PAGESIZE);
for (argc--, argv++; argc != 0; argc--, argv++) {
int fd = open(*argv, O_RDONLY);
if (fd == -1) {
warn("%s", *argv);
continue;
}
if (fstat(fd, &st) < 0) {
warn("%s", *argv);
close(fd);
continue;
}
_rtld_paths = NULL;
_rtld_trust = (st.st_mode & (S_ISUID | S_ISGID)) == 0;
if (_rtld_trust)
_rtld_add_paths(&_rtld_paths, getenv("LD_LIBRARY_PATH"));
_rtld_process_hints(&_rtld_paths, &_rtld_xforms, _PATH_LD_HINTS);
_rtld_objmain = _rtld_map_object(xstrdup(*argv), fd, &st);
if (_rtld_objmain == NULL) {
if (ldd_aout(*argv, fd) < 0)
warnx("%s", error_message);
close(fd);
continue;
}
close(fd);
_rtld_objmain->path = xstrdup(*argv);
_rtld_digest_dynamic(_rtld_objmain);
/* Link the main program into the list of objects. */
*_rtld_objtail = _rtld_objmain;
_rtld_objtail = &_rtld_objmain->next;
++_rtld_objmain->refcount;
(void) _rtld_load_needed_objects(_rtld_objmain, 0);
printf("%s:\n", _rtld_objmain->path);
print_needed(_rtld_objmain);
while (_rtld_objlist != NULL) {
Obj_Entry *obj = _rtld_objlist;
_rtld_objlist = obj->next;
while (obj->rpaths != NULL) {
const Search_Path *rpath = obj->rpaths;
obj->rpaths = rpath->sp_next;
free((void *) rpath->sp_path);
free((void *) rpath);
}
while (obj->needed != NULL) {
const Needed_Entry *needed = obj->needed;
obj->needed = needed->next;
free((void *) needed);
}
(void) munmap(obj->mapbase, obj->mapsize);
free(obj->path);
free(obj);
}
_rtld_objmain = NULL;
_rtld_objtail = &_rtld_objlist;
}
return 0;
}
/*
* Error reporting function. Use it like printf. If formats the message
* into a buffer, and sets things up so that the next call to dlerror()
* will return the message.
*/
void
_rtld_error(const char *fmt, ...)
{
static char buf[512];
va_list ap;
va_start(ap, fmt);
xvsnprintf(buf, sizeof buf, fmt, ap);
error_message = buf;
va_end(ap);
}
char *
dlerror()
{
char *msg = error_message;
error_message = NULL;
return msg;
}
static void
print_needed(Obj_Entry *obj)
{
const Needed_Entry *needed;
for (needed = obj->needed; needed != NULL; needed = needed->next) {
char libnamebuf[200];
const char *libname = obj->strtab + needed->name, *cp;
if (strncmp(libname, "lib", 3) == 0
&& (cp = strstr(libname, ".so")) != NULL) {
strcpy(libnamebuf, "-l");
memcpy(&libnamebuf[2], libname + 3, cp - (libname + 3));
strcpy(&libnamebuf[cp - (libname + 3) + 2], cp + 3);
libname = libnamebuf;
}
if (needed->obj != NULL) {
print_needed(needed->obj);
if (!needed->obj->printed) {
printf("\t %s => %s\n", libname,
needed->obj->path);
needed->obj->printed = 1;
}
} else {
printf("\t %s => not found\n", libname);
}
}
}
static int
ldd_aout(char *file, int fd)
{
struct exec hdr;
int status, rval;
lseek(fd, 0, SEEK_SET);
if (read(fd, &hdr, sizeof hdr) != sizeof hdr
|| (N_GETFLAG(hdr) & EX_DPMASK) != EX_DYNAMIC
#if 1 /* Compatibility */
|| hdr.a_entry < N_PAGSIZ(hdr)
#endif
) {
/* calling function prints warning */
return -1;
}
setenv("LD_TRACE_LOADED_OBJECTS", "", 1);
setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", file, 1);
printf("%s:\n", file);
fflush(stdout);
rval = 0;
switch (fork()) {
case -1:
err(1, "fork");
break;
default:
if (wait(&status) <= 0) {
warn("wait");
rval |= 1;
} else if (WIFSIGNALED(status)) {
fprintf(stderr, "%s: signal %d\n",
file, WTERMSIG(status));
rval |= 1;
} else if (WIFEXITED(status) && WEXITSTATUS(status)) {
fprintf(stderr, "%s: exit status %d\n",
file, WEXITSTATUS(status));
rval |= 1;
}
break;
case 0:
rval |= execl(file, file, NULL) != 0;
perror(file);
_exit(1);
}
return rval;
}