xref: /titanic_41/usr/src/cmd/sgs/ldd/common/ldd.c (revision 3f7d54a6b84904c8f4d8daa4c7b577bede7df8b9)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  *
21  *	Copyright (c) 1988 AT&T
22  *	  All Rights Reserved
23  *
24  *
25  * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
26  */
27 
28 /*
29  * Print the list of shared objects required by a dynamic executable or shared
30  * object.
31  *
32  * usage is: ldd [-d | -r] [-c] [-e envar] [-i] [-f] [-L] [-l] [-p] [-s]
33  *		[-U | -u] [-v] [-w] file(s)
34  *
35  * ldd opens the file and verifies the information in the elf header.
36  * If the file is a dynamic executable, we set up some environment variables
37  * and exec(2) the file.  If the file is a shared object, we preload the
38  * file with a dynamic executable stub. The runtime linker (ld.so.1) actually
39  * provides the diagnostic output, according to the environment variables set.
40  *
41  * If neither -d nor -r is specified, we set only LD_TRACE_LOADED_OBJECTS_[AE].
42  * The runtime linker will print the pathnames of all dynamic objects it
43  * loads, and then exit.  Note that we distiguish between ELF and AOUT objects
44  * when setting this environment variable - AOUT executables cause the mapping
45  * of sbcp, the dependencies of which the user isn't interested in.
46  *
47  * If -d or -r is specified, we also set LD_WARN=1; the runtime linker will
48  * perform its normal relocations and issue warning messages for unresolved
49  * references. It will then exit.
50  * If -r is specified, we set LD_BIND_NOW=1, so that the runtime linker
51  * will perform all relocations, otherwise (under -d) the runtime linker
52  * will not perform PLT (function) type relocations.
53  *
54  * If -c is specified we also set LD_NOCONFIG=1, thus disabling any
55  * configuration file use.
56  *
57  * If -e is specified the associated environment variable is set for the
58  * child process that will produce ldd's diagnostics.
59  *
60  * If -i is specified, we set LD_INIT=1. The order of inititialization
61  * sections to be executed is printed. We also set LD_WARN=1.
62  *
63  * If -f is specified, we will run ldd as root on executables that have
64  * an unsercure runtime linker that does not live under the "/usr/lib"
65  * directory.  By default we will not let this happen.
66  *
67  * If -l is specified it generates a warning for any auxiliary filter not found.
68  * Prior to 2.8 this forced any filters to load (all) their filtees.  This is
69  * now the default, however missing auxiliary filters don't generate any error
70  * diagniostic.  See also -L.
71  *
72  * If -L is specified we revert to lazy loading, thus any filtee or lazy
73  * dependency loading is deferred until relocations cause loading.  Without
74  * this option we set LD_LOADFLTR=1, thus forcing any filters to load (all)
75  * their filtees, and LD_NOLAZYLOAD=1 thus forcing immediate processing of
76  * any lazy loaded dependencies.
77  *
78  * If -s is specified we also set LD_TRACE_SEARCH_PATH=1, thus enabling
79  * the runtime linker to indicate the search algorithm used.
80  *
81  * If -v is specified we also set LD_VERBOSE=1, thus enabling the runtime
82  * linker to indicate all object dependencies (not just the first object
83  * loaded) together with any versionig requirements.
84  *
85  * If -U or -u is specified unused dependencies are detected.  -u causes
86  * LD_UNUSED=1 to be set, which causes dependencies that are unused within the
87  * process to be detected.  -U causes LD_UNREF=1 to be set, which causes
88  * unreferenced objects, and unreferenced cyclic dependencies to be detected.
89  * These options assert that at least -d is set as relocation references are
90  * what determine an objects use.
91  *
92  * If -w is specified, no unresolved weak references are allowed.  -w causes
93  * LD_NOUNRESWEAK=1 to be set.  By default, an unresolved weak reference is
94  * allowed, and a "0" is written to the relocation offset.  The -w option
95  * disables this default.  Any weak references that can not be resolved result
96  * in relocation error messages.  This option has no use without -r or -d.
97  *
98  * If the -p option is specified, no unresolved PARENT or EXTERN references are
99  * allowed.  -p causes LD_NOPAREXT=1 to be set.  By default, PARENT and EXTERN
100  * references, which have been explicitly assigned via a mapfile when a shared
101  * object was built, imply that a caller will provide the symbols, and hence
102  * these are not reported as relocation errors.  Note, the -p option is asserted
103  * by default when either the -r or -d options are used to inspect a dynamic
104  * executable.  This option has no use with a shared object without -r or -d.
105  */
106 #include	<fcntl.h>
107 #include	<stdio.h>
108 #include	<string.h>
109 #include	<_libelf.h>
110 #include	<stdlib.h>
111 #include	<unistd.h>
112 #include	<wait.h>
113 #include	<locale.h>
114 #include	<errno.h>
115 #include	<signal.h>
116 #include	"machdep.h"
117 #include	"sgs.h"
118 #include	"conv.h"
119 #include	"a.out.h"
120 #include	"msg.h"
121 
122 static int	elf_check(int, char *, char *, Elf *, int);
123 static int	aout_check(int, char *, char *, int, int);
124 static int	run(int, char *, char *, const char *, int);
125 
126 
127 /*
128  * Define all environment variable strings.  The character following the "="
129  * will be written to, to disable or enable the associated feature.
130  */
131 static char	bind[] =	"LD_BIND_NOW= ",
132 		load_elf[] =	"LD_TRACE_LOADED_OBJECTS_E= ",
133 		load_aout[] =	"LD_TRACE_LOADED_OBJECTS_A= ",
134 		path[] =	"LD_TRACE_SEARCH_PATHS= ",
135 		verb[] =	"LD_VERBOSE= ",
136 		warn[] =	"LD_WARN= ",
137 		conf[] =	"LD_NOCONFIG= ",
138 		fltr[] =	"LD_LOADFLTR= ",
139 		lazy[] =	"LD_NOLAZYLOAD=1",
140 		init[] =	"LD_INIT= ",
141 		uref[] =	"LD_UNREF= ",
142 		used[] =	"LD_UNUSED= ",
143 		weak[] =	"LD_NOUNRESWEAK= ",
144 		nope[] =	"LD_NOPAREXT= ";
145 static char	*load;
146 
147 static const char	*prefile_32, *prefile_64, *prefile;
148 static APlist		*eopts = NULL;
149 
150 int
151 main(int argc, char **argv, char **envp)
152 {
153 	char	*str, *cname = argv[0];
154 
155 	Elf	*elf;
156 	int	cflag = 0, dflag = 0, fflag = 0, iflag = 0, Lflag = 0;
157 	int	lflag = 0, rflag = 0, sflag = 0, Uflag = 0, uflag = 0;
158 	int	pflag = 0, vflag = 0, wflag = 0, nfile, var, error = 0;
159 
160 	Aliste	idx;
161 
162 	/*
163 	 * If we're on a 64-bit kernel, try to exec a full 64-bit version of
164 	 * the binary.  If successful, conv_check_native() won't return.
165 	 *
166 	 * This is done to ensure that ldd can handle objects >2GB.
167 	 * ldd uses libelf, which is not large file capable. The
168 	 * 64-bit ldd can handle any sized object.
169 	 */
170 	(void) conv_check_native(argv, envp);
171 
172 	/*
173 	 * Establish locale.
174 	 */
175 	(void) setlocale(LC_MESSAGES, MSG_ORIG(MSG_STR_EMPTY));
176 	(void) textdomain(MSG_ORIG(MSG_SUNW_OST_SGS));
177 
178 	/*
179 	 * verify command line syntax and process arguments
180 	 */
181 	opterr = 0;				/* disable getopt error mesg */
182 
183 	while ((var = getopt(argc, argv, MSG_ORIG(MSG_STR_GETOPT))) != EOF) {
184 		switch (var) {
185 		case 'c' :			/* enable config search */
186 			cflag = 1;
187 			break;
188 		case 'd' :			/* perform data relocations */
189 			dflag = 1;
190 			if (rflag)
191 				error++;
192 			break;
193 		case 'e' :
194 			if (aplist_append(&eopts, optarg, 10) == NULL) {
195 				(void) fprintf(stderr, MSG_INTL(MSG_SYS_MALLOC),
196 				    cname);
197 				exit(1);
198 			}
199 			break;
200 		case 'f' :
201 			fflag = 1;
202 			break;
203 		case 'L' :
204 			Lflag = 1;
205 			break;
206 		case 'l' :
207 			lflag = 1;
208 			break;
209 		case 'i' :			/* print the order of .init */
210 			iflag = 1;
211 			break;
212 		case 'p' :
213 			pflag = 1;		/* expose unreferenced */
214 			break;			/*	parent or externals */
215 		case 'r' :			/* perform all relocations */
216 			rflag = 1;
217 			if (dflag)
218 				error++;
219 			break;
220 		case 's' :			/* enable search path output */
221 			sflag = 1;
222 			break;
223 		case 'U' :			/* list unreferenced */
224 			Uflag = 1;		/*	dependencies */
225 			if (uflag)
226 				error++;
227 			break;
228 		case 'u' :			/* list unused dependencies */
229 			uflag = 1;
230 			if (Uflag)
231 				error++;
232 			break;
233 		case 'v' :			/* enable verbose output */
234 			vflag = 1;
235 			break;
236 		case 'w' :			/* expose unresolved weak */
237 			wflag = 1;		/*	references */
238 			break;
239 		default :
240 			error++;
241 			break;
242 		}
243 		if (error)
244 			break;
245 	}
246 	if (error) {
247 		(void) fprintf(stderr, MSG_INTL(MSG_ARG_USAGE), cname);
248 		exit(1);
249 	}
250 
251 	/*
252 	 * Determine if any of the LD_PRELOAD family is already set in the
253 	 * environment, if so we'll continue to analyze each object with the
254 	 * appropriate setting.
255 	 */
256 	if (((prefile_32 = getenv(MSG_ORIG(MSG_LD_PRELOAD_32))) == NULL) ||
257 	    (*prefile_32 == '\0')) {
258 		prefile_32 = MSG_ORIG(MSG_STR_EMPTY);
259 	}
260 	if (((prefile_64 = getenv(MSG_ORIG(MSG_LD_PRELOAD_64))) == NULL) ||
261 	    (*prefile_64 == '\0')) {
262 		prefile_64 = MSG_ORIG(MSG_STR_EMPTY);
263 	}
264 	if (((prefile = getenv(MSG_ORIG(MSG_LD_PRELOAD))) == NULL) ||
265 	    (*prefile == '\0')) {
266 		prefile = MSG_ORIG(MSG_STR_EMPTY);
267 	}
268 
269 	/*
270 	 * Determine if any environment requests are for the LD_PRELOAD family,
271 	 * and if so override any environment settings we've established above.
272 	 */
273 	for (APLIST_TRAVERSE(eopts, idx, str)) {
274 		if ((strncmp(str, MSG_ORIG(MSG_LD_PRELOAD_32),
275 		    MSG_LD_PRELOAD_32_SIZE)) == 0) {
276 			str += MSG_LD_PRELOAD_32_SIZE;
277 			if ((*str++ == '=') && (*str != '\0'))
278 				prefile_32 = str;
279 			continue;
280 		}
281 		if ((strncmp(str, MSG_ORIG(MSG_LD_PRELOAD_64),
282 		    MSG_LD_PRELOAD_64_SIZE)) == 0) {
283 			str += MSG_LD_PRELOAD_64_SIZE;
284 			if ((*str++ == '=') && (*str != '\0'))
285 				prefile_64 = str;
286 			continue;
287 		}
288 		if ((strncmp(str, MSG_ORIG(MSG_LD_PRELOAD),
289 		    MSG_LD_PRELOAD_SIZE)) == 0) {
290 			str += MSG_LD_PRELOAD_SIZE;
291 			if ((*str++ == '=') && (*str != '\0'))
292 				prefile = str;
293 			continue;
294 		}
295 	}
296 
297 	/*
298 	 * Set the appropriate relocation environment variables (Note unsetting
299 	 * the environment variables is done just in case the user already
300 	 * has these in their environment ... sort of thing the test folks
301 	 * would do :-)
302 	 */
303 	warn[sizeof (warn) - 2] = (dflag || rflag || Uflag || uflag) ? '1' :
304 	    '\0';
305 	bind[sizeof (bind) - 2] = (rflag) ? '1' : '\0';
306 	path[sizeof (path) - 2] = (sflag) ? '1' : '\0';
307 	verb[sizeof (verb) - 2] = (vflag) ? '1' : '\0';
308 	fltr[sizeof (fltr) - 2] = (Lflag) ? '\0' : (lflag) ? '2' : '1';
309 	init[sizeof (init) - 2] = (iflag) ? '1' : '\0';
310 	conf[sizeof (conf) - 2] = (cflag) ? '1' : '\0';
311 	lazy[sizeof (lazy) - 2] = (Lflag) ? '\0' : '1';
312 	uref[sizeof (uref) - 2] = (Uflag) ? '1' : '\0';
313 	used[sizeof (used) - 2] = (uflag) ? '1' : '\0';
314 	weak[sizeof (weak) - 2] = (wflag) ? '1' : '\0';
315 	nope[sizeof (nope) - 2] = (pflag) ? '1' : '\0';
316 
317 	/*
318 	 * coordinate libelf's version information
319 	 */
320 	if (elf_version(EV_CURRENT) == EV_NONE) {
321 		(void) fprintf(stderr, MSG_INTL(MSG_ELF_LIBELF), cname,
322 		    EV_CURRENT);
323 		exit(1);
324 	}
325 
326 	/*
327 	 * Loop through remaining arguments.  Note that from here on there
328 	 * are no exit conditions so that we can process a list of files,
329 	 * any error condition is retained for a final exit status.
330 	 */
331 	nfile = argc - optind;
332 	for (; optind < argc; optind++) {
333 		char	*fname = argv[optind];
334 
335 		/*
336 		 * Open file (do this before checking access so that we can
337 		 * provide the user with better diagnostics).
338 		 */
339 		if ((var = open(fname, O_RDONLY)) == -1) {
340 			int	err = errno;
341 			(void) fprintf(stderr, MSG_INTL(MSG_SYS_OPEN), cname,
342 			    fname, strerror(err));
343 			error = 1;
344 			continue;
345 		}
346 
347 		/*
348 		 * Get the files elf descriptor and process it as an elf or
349 		 * a.out (4.x) file.
350 		 */
351 		elf = elf_begin(var, ELF_C_READ, (Elf *)0);
352 		switch (elf_kind(elf)) {
353 		case ELF_K_AR :
354 			(void) fprintf(stderr, MSG_INTL(MSG_USP_NODYNORSO),
355 			    cname, fname);
356 			error = 1;
357 			break;
358 		case ELF_K_COFF:
359 			(void) fprintf(stderr, MSG_INTL(MSG_USP_UNKNOWN),
360 			    cname, fname);
361 			error = 1;
362 			break;
363 		case ELF_K_ELF:
364 			if (elf_check(nfile, fname, cname, elf, fflag) != NULL)
365 				error = 1;
366 			break;
367 		default:
368 			/*
369 			 * This is either an unknown file or an aout format
370 			 */
371 			if (aout_check(nfile, fname, cname, var, fflag) != NULL)
372 				error = 1;
373 			break;
374 		}
375 		(void) elf_end(elf);
376 		(void) close(var);
377 	}
378 	return (error);
379 }
380 
381 
382 
383 static int
384 elf_check(int nfile, char *fname, char *cname, Elf *elf, int fflag)
385 {
386 	Conv_inv_buf_t	inv_buf;
387 	GElf_Ehdr 	ehdr;
388 	GElf_Phdr 	phdr;
389 	int		dynamic = 0, interp = 0, cnt, class;
390 
391 	/*
392 	 * verify information in file header
393 	 */
394 	if (gelf_getehdr(elf, &ehdr) == NULL) {
395 		(void) fprintf(stderr, MSG_INTL(MSG_ELF_GETEHDR),
396 		    cname, fname, elf_errmsg(-1));
397 		return (1);
398 	}
399 
400 	/*
401 	 * Compatible machine
402 	 */
403 	if ((ehdr.e_machine != M_MACH_32) && (ehdr.e_machine != M_MACH_64) &&
404 	    (ehdr.e_machine != M_MACHPLUS)) {
405 		(void) fprintf(stderr, MSG_INTL(MSG_ELF_MACHTYPE), cname, fname,
406 		    conv_ehdr_mach(ehdr.e_machine, 0, &inv_buf));
407 		return (1);
408 	}
409 
410 	/*
411 	 * Compatible encoding (byte order)
412 	 */
413 	if (ehdr.e_ident[EI_DATA] != M_DATA) {
414 		(void) fprintf(stderr, MSG_INTL(MSG_ELF_DATA), cname, fname,
415 		    conv_ehdr_data(ehdr.e_ident[EI_DATA], 0, &inv_buf));
416 		return (1);
417 	}
418 
419 	/*
420 	 * Compatible class
421 	 */
422 	switch (class = ehdr.e_ident[EI_CLASS]) {
423 	case ELFCLASS32:
424 		/*
425 		 * If M_MACH is not the same thing as M_MACHPLUS and this
426 		 * is an M_MACHPLUS object, then the corresponding header
427 		 * flag must be set.
428 		 */
429 		if ((ehdr.e_machine != M_MACH) &&
430 		    ((ehdr.e_flags & M_FLAGSPLUS) == 0)) {
431 			(void) fprintf(stderr, MSG_INTL(MSG_ELF_MACHFLAGS),
432 			    cname, fname);
433 			return (1);
434 		}
435 		break;
436 	case ELFCLASS64:
437 		/* Requires 64-bit kernel */
438 		if (conv_sys_eclass() == ELFCLASS32) {
439 			(void) fprintf(stderr, MSG_INTL(MSG_ELF_KCLASS32),
440 			    cname, fname, conv_ehdr_class(class, 0, &inv_buf));
441 			return (1);
442 		}
443 		break;
444 	default:
445 		(void) fprintf(stderr, MSG_INTL(MSG_ELF_CLASS), cname, fname,
446 		    conv_ehdr_class(class, 0, &inv_buf));
447 		return (1);
448 	}
449 
450 	/*
451 	 * Object type
452 	 */
453 	if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN) &&
454 	    (ehdr.e_type != ET_REL)) {
455 		(void) fprintf(stderr, MSG_INTL(MSG_ELF_BADMAGIC),
456 		    cname, fname);
457 		return (1);
458 	}
459 
460 	/*
461 	 * Check that the file is executable.  Dynamic executables must be
462 	 * executable to be exec'ed.  Shared objects need not be executable to
463 	 * be mapped with a dynamic executable, however, by convention they're
464 	 * supposed to be executable.
465 	 */
466 	if (access(fname, X_OK) != 0) {
467 		if (ehdr.e_type == ET_EXEC) {
468 			(void) fprintf(stderr, MSG_INTL(MSG_USP_NOTEXEC_1),
469 			    cname, fname);
470 			return (1);
471 		}
472 		(void) fprintf(stderr, MSG_INTL(MSG_USP_NOTEXEC_2), cname,
473 		    fname);
474 	}
475 
476 	/*
477 	 * Determine whether we have a dynamic section or interpretor.
478 	 */
479 	for (cnt = 0; cnt < (int)ehdr.e_phnum; cnt++) {
480 		if (dynamic && interp)
481 			break;
482 
483 		if (gelf_getphdr(elf, cnt, &phdr) == NULL) {
484 			(void) fprintf(stderr, MSG_INTL(MSG_ELF_GETPHDR),
485 			    cname, fname, elf_errmsg(-1));
486 			return (1);
487 		}
488 
489 		if (phdr.p_type == PT_DYNAMIC) {
490 			dynamic = 1;
491 			continue;
492 		}
493 
494 		if (phdr.p_type != PT_INTERP)
495 			continue;
496 
497 		interp = 1;
498 
499 		/*
500 		 * If fflag is not set, and euid == root, and the interpreter
501 		 * does not live under /lib, /usr/lib or /etc/lib then don't
502 		 * allow ldd to execute the image.  This prevents someone
503 		 * creating a `trojan horse' by substituting their own
504 		 * interpreter that could preform privileged operations
505 		 * when ldd is against it.
506 		 */
507 		if ((fflag == 0) && (geteuid() == 0) &&
508 		    (strcmp(fname, conv_lddstub(class)) != 0)) {
509 			char	*interpreter;
510 
511 			/*
512 			 * Does the interpreter live under a trusted directory.
513 			 */
514 			interpreter = elf_getident(elf, 0) + phdr.p_offset;
515 
516 			if ((strncmp(interpreter, MSG_ORIG(MSG_PTH_USRLIB),
517 			    MSG_PTH_USRLIB_SIZE) != 0) &&
518 			    (strncmp(interpreter, MSG_ORIG(MSG_PTH_LIB),
519 			    MSG_PTH_LIB_SIZE) != 0) &&
520 			    (strncmp(interpreter, MSG_ORIG(MSG_PTH_ETCLIB),
521 			    MSG_PTH_ETCLIB_SIZE) != 0)) {
522 				(void) fprintf(stderr, MSG_INTL(MSG_USP_ELFINS),
523 				    cname, fname, interpreter);
524 				return (1);
525 			}
526 		}
527 	}
528 
529 	/*
530 	 * Catch the case of a static executable (ie, an ET_EXEC that has a set
531 	 * of program headers but no PT_DYNAMIC).
532 	 */
533 	if (ehdr.e_phnum && !dynamic) {
534 		(void) fprintf(stderr, MSG_INTL(MSG_USP_NODYNORSO), cname,
535 		    fname);
536 		return (1);
537 	}
538 
539 	/*
540 	 * If there is a dynamic section, then check for the DF_1_NOHDR
541 	 * flag, and bail if it is present. Such objects are created using
542 	 * a mapfile option (?N in the version 1 syntax, or HDR_NOALLOC
543 	 * otherwise). The ELF header and program headers are
544 	 * not mapped as part of the first segment, and virtual addresses
545 	 * are computed without them. If ldd tries to interpret such
546 	 * a file, it will become confused and generate bad output or
547 	 * crash. Such objects are always special purpose files (like an OS
548 	 * kernel) --- files for which the ldd operation doesn't make sense.
549 	 */
550 	if (dynamic && (_gelf_getdyndtflags_1(elf) & DF_1_NOHDR)) {
551 		(void) fprintf(stderr, MSG_INTL(MSG_USP_NOHDR), cname,
552 		    fname);
553 		return (1);
554 	}
555 
556 	load = load_elf;
557 
558 	/*
559 	 * Run the required program (shared and relocatable objects require the
560 	 * use of lddstub).
561 	 */
562 	if ((ehdr.e_type == ET_EXEC) && interp)
563 		return (run(nfile, cname, fname, (const char *)fname, class));
564 	else
565 		return (run(nfile, cname, fname, conv_lddstub(class), class));
566 }
567 
568 static int
569 aout_check(int nfile, char *fname, char *cname, int fd, int fflag)
570 {
571 	struct exec32	aout;
572 	int		err;
573 
574 	if (lseek(fd, 0, SEEK_SET) != 0) {
575 		err = errno;
576 		(void) fprintf(stderr, MSG_INTL(MSG_SYS_LSEEK), cname, fname,
577 		    strerror(err));
578 		return (1);
579 	}
580 	if (read(fd, (char *)&aout, sizeof (aout)) != sizeof (aout)) {
581 		err = errno;
582 		(void) fprintf(stderr, MSG_INTL(MSG_SYS_READ), cname, fname,
583 		    strerror(err));
584 		return (1);
585 	}
586 	if (aout.a_machtype != M_SPARC) {
587 		(void) fprintf(stderr, MSG_INTL(MSG_USP_UNKNOWN), cname, fname);
588 		return (1);
589 	}
590 	if (N_BADMAG(aout) || !aout.a_dynamic) {
591 		(void) fprintf(stderr, MSG_INTL(MSG_USP_NODYNORSO), cname,
592 		    fname);
593 		return (1);
594 	}
595 	if (!fflag && (geteuid() == 0)) {
596 		(void) fprintf(stderr, MSG_INTL(MSG_USP_AOUTINS), cname, fname);
597 		return (1);
598 	}
599 
600 	/*
601 	 * Run the required program.
602 	 */
603 	if ((aout.a_magic == ZMAGIC) && (aout.a_entry <= sizeof (aout))) {
604 		load = load_elf;
605 		return (run(nfile, cname, fname, conv_lddstub(ELFCLASS32),
606 		    ELFCLASS32));
607 	} else {
608 		load = load_aout;
609 		return (run(nfile, cname, fname, (const char *)fname,
610 		    ELFCLASS32));
611 	}
612 }
613 
614 
615 /*
616  * Run the required program, setting the preload and trace environment
617  * variables accordingly.
618  */
619 static int
620 run(int nfile, char *cname, char *fname, const char *ename, int class)
621 {
622 	const char	*preload = 0;
623 	int		pid, status;
624 
625 	if ((pid = fork()) == -1) {
626 		int	err = errno;
627 		(void) fprintf(stderr, MSG_INTL(MSG_SYS_FORK), cname,
628 		    strerror(err));
629 		return (1);
630 	}
631 
632 	if (pid) {				/* parent */
633 		while (wait(&status) != pid)
634 			;
635 		if (WIFSIGNALED(status) && ((WSIGMASK & status) != SIGPIPE)) {
636 			(void) fprintf(stderr, MSG_INTL(MSG_SYS_EXEC), cname,
637 			    fname);
638 			(void) fprintf(stderr, MSG_INTL(MSG_SYS_EXEC_SIG),
639 			    (WSIGMASK & status), ((status & WCOREFLG) ?
640 			    MSG_INTL(MSG_SYS_EXEC_CORE) :
641 			    MSG_ORIG(MSG_STR_EMPTY)));
642 			status = 1;
643 		} else if (WHIBYTE(status)) {
644 			(void) fprintf(stderr, MSG_INTL(MSG_SYS_EXEC), cname,
645 			    fname);
646 			(void) fprintf(stderr, MSG_INTL(MSG_SYS_EXEC_STAT),
647 			    WHIBYTE(status));
648 			status = 1;
649 		}
650 	} else {				/* child */
651 		Aliste	idx;
652 		char	*str;
653 		size_t	size;
654 
655 		/*
656 		 * When using ldd(1) to analyze a shared object we preload the
657 		 * shared object with lddstub.  Any additional preload
658 		 * requirements are added after the object being analyzed, this
659 		 * allows us to skip the first object but produce diagnostics
660 		 * for each other preloaded object.
661 		 */
662 		if (fname != ename) {
663 			char		*str;
664 			const char	*files = prefile;
665 			const char	*format = MSG_ORIG(MSG_STR_FMT1);
666 
667 			for (str = fname; *str; str++)
668 				if (*str == '/') {
669 					format = MSG_ORIG(MSG_STR_FMT2);
670 					break;
671 			}
672 
673 			preload = MSG_ORIG(MSG_LD_PRELOAD);
674 
675 			/*
676 			 * Determine which preload files and preload environment
677 			 * variable to use.
678 			 */
679 			if (class == ELFCLASS64) {
680 				if (prefile_64 != MSG_ORIG(MSG_STR_EMPTY)) {
681 					files = prefile_64;
682 					preload = MSG_ORIG(MSG_LD_PRELOAD_64);
683 				}
684 			} else {
685 				if (prefile_32 != MSG_ORIG(MSG_STR_EMPTY)) {
686 					files = prefile_32;
687 					preload = MSG_ORIG(MSG_LD_PRELOAD_32);
688 				}
689 			}
690 
691 			if ((str = (char *)malloc(strlen(preload) +
692 			    strlen(fname) + strlen(files) + 5)) == 0) {
693 				(void) fprintf(stderr, MSG_INTL(MSG_SYS_MALLOC),
694 				    cname);
695 				exit(1);
696 			}
697 
698 			(void) sprintf(str, format, preload, fname, files);
699 			if (putenv(str) != 0) {
700 				(void) fprintf(stderr, MSG_INTL(MSG_ENV_FAILED),
701 				    cname);
702 				exit(1);
703 			}
704 
705 			/*
706 			 * The pointer "load" has be assigned to load_elf[] or
707 			 * load_aout[].  Use the size of load_elf[] as the size
708 			 * of load_aout[] is the same.
709 			 */
710 			load[sizeof (load_elf) - 2] = '2';
711 		} else
712 			load[sizeof (load_elf) - 2] = '1';
713 
714 
715 		/*
716 		 * Establish new environment variables to affect the child
717 		 * process.
718 		 */
719 		if ((putenv(warn) != 0) || (putenv(bind) != 0) ||
720 		    (putenv(path) != 0) || (putenv(verb) != 0) ||
721 		    (putenv(fltr) != 0) || (putenv(conf) != 0) ||
722 		    (putenv(init) != 0) || (putenv(lazy) != 0) ||
723 		    (putenv(uref) != 0) || (putenv(used) != 0) ||
724 		    (putenv(weak) != 0) || (putenv(load) != 0) ||
725 		    (putenv(nope) != 0)) {
726 			(void) fprintf(stderr, MSG_INTL(MSG_ENV_FAILED), cname);
727 			exit(1);
728 		}
729 
730 		/*
731 		 * Establish explicit environment requires (but don't override
732 		 * any preload request established to process a shared object).
733 		 */
734 		size = 0;
735 		for (APLIST_TRAVERSE(eopts, idx, str)) {
736 			if (preload) {
737 				if (size == 0)
738 					size = strlen(preload);
739 				if ((strncmp(preload, str, size) == 0) &&
740 				    (str[size] == '=')) {
741 					continue;
742 				}
743 			}
744 			if (putenv(str) != 0) {
745 				(void) fprintf(stderr, MSG_INTL(MSG_ENV_FAILED),
746 				    cname);
747 				exit(1);
748 			}
749 		}
750 
751 		/*
752 		 * Execute the object and let ld.so.1 do the rest.
753 		 */
754 		if (nfile > 1)
755 			(void) printf(MSG_ORIG(MSG_STR_FMT3), fname);
756 		(void) fflush(stdout);
757 		if ((execl(ename, ename, (char *)0)) == -1) {
758 			(void) fprintf(stderr, MSG_INTL(MSG_SYS_EXEC), cname,
759 			    fname);
760 			perror(ename);
761 			_exit(0);
762 			/* NOTREACHED */
763 		}
764 	}
765 	return (status);
766 }
767 
768 const char *
769 _ldd_msg(Msg mid)
770 {
771 	return (gettext(MSG_ORIG(mid)));
772 }
773