aboutsummaryrefslogtreecommitdiffstats
path: root/gnu/usr.bin/ld/rtld/rtld.c
blob: 05c3e369fec38822825c334c7b2ca33bdde1754b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
/*
 * 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 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.
 *
 *	$Id: rtld.c,v 1.17 1994/06/15 22:41:15 rich Exp $
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/errno.h>
#include <sys/mman.h>
#ifndef BSD
#define MAP_COPY	MAP_PRIVATE
#define MAP_ANON	0
#endif
#include <err.h>
#include <fcntl.h>
#include <a.out.h>
#include <stab.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

#include "ld.h"

#ifndef BSD		/* Need do better than this */
#define NEED_DEV_ZERO	1
#endif

/*
 * Loader private data, hung off <so_map>->som_spd
 */
struct somap_private {
	int		spd_version;
	struct so_map	*spd_parent;
	int		spd_refcount;
	int		spd_flags;
#define RTLD_MAIN	1
#define RTLD_RTLD	2
#define RTLD_DL		4

#ifdef SUN_COMPAT
	long		spd_offset;	/* Correction for Sun main programs */
#endif
};

#define LM_PRIVATE(smp)	((struct somap_private *)(smp)->som_spd)

#ifdef SUN_COMPAT
#define LM_OFFSET(smp)	(LM_PRIVATE(smp)->spd_offset)
#else
#define LM_OFFSET(smp)	(0)
#endif

/* Base address for section_dispatch_table entries */
#define LM_LDBASE(smp)	(smp->som_addr + LM_OFFSET(smp))

/* Start of text segment */
#define LM_TXTADDR(smp)	(smp->som_addr == (caddr_t)0 ? PAGSIZ : 0)

/* Start of run-time relocation_info */
#define LM_REL(smp)	((struct relocation_info *) \
	(smp->som_addr + LM_OFFSET(smp) + LD_REL((smp)->som_dynamic)))

/* Start of symbols */
#define LM_SYMBOL(smp, i)	((struct nzlist *) \
	(smp->som_addr + LM_OFFSET(smp) + LD_SYMBOL((smp)->som_dynamic) + \
		i * (LD_VERSION_NZLIST_P(smp->som_dynamic->d_version) ? \
			sizeof(struct nzlist) : sizeof(struct nlist))))

/* Start of hash table */
#define LM_HASH(smp)	((struct rrs_hash *) \
	((smp)->som_addr + LM_OFFSET(smp) + LD_HASH((smp)->som_dynamic)))

/* Start of strings */
#define LM_STRINGS(smp)	((char *) \
	((smp)->som_addr + LM_OFFSET(smp) + LD_STRINGS((smp)->som_dynamic)))

/* End of text */
#define LM_ETEXT(smp)	((char *) \
	((smp)->som_addr + LM_TXTADDR(smp) + LD_TEXTSZ((smp)->som_dynamic)))

/* PLT is in data segment, so don't use LM_OFFSET here */
#define LM_PLT(smp)	((jmpslot_t *) \
	((smp)->som_addr + LD_PLT((smp)->som_dynamic)))

/* Parent of link map */
#define LM_PARENT(smp)	(LM_PRIVATE(smp)->spd_parent)

char			**environ;
char			*__progname;
int			errno;

static uid_t		uid, euid;
static gid_t		gid, egid;
static int		careful;
static char		__main_progname[] = "main";
static char		*main_progname = __main_progname;
static char		us[] = "/usr/libexec/ld.so";

struct so_map		*link_map_head, *main_map;
struct so_map		**link_map_tail = &link_map_head;
struct rt_symbol	*rt_symbol_head;

static void		*__dlopen __P((char *, int));
static int		__dlclose __P((void *));
static void		*__dlsym __P((void *, char *));
static int		__dlctl __P((void *, int, void *));

static struct ld_entry	ld_entry = {
	__dlopen, __dlclose, __dlsym, __dlctl
};

       void		xprintf __P((char *, ...));
static void		load_objects __P((	struct crt_ldso *,
						struct _dynamic *));
static struct so_map	*map_object __P((struct sod *, struct so_map *));
static struct so_map	*alloc_link_map __P((	char *, struct sod *,
						struct so_map *, caddr_t,
						struct _dynamic *));
static inline void	check_text_reloc __P((	struct relocation_info *,
						struct so_map *,
						caddr_t));
static void		reloc_map __P((struct so_map *));
static void		reloc_copy __P((struct so_map *));
static void		init_map __P((struct so_map *, char *));
static char		*rtfindlib __P((char *, int, int, int *));
void			binder_entry __P((void));
long			binder __P((jmpslot_t *));
static struct nzlist	*lookup __P((char *, struct so_map **, int));
static inline struct rt_symbol	*lookup_rts __P((char *));
static struct rt_symbol	*enter_rts __P((char *, long, int, caddr_t,
						long, struct so_map *));

static inline int
strcmp (register const char *s1, register const char *s2)
{
	while (*s1 == *s2++)
		if (*s1++ == 0)
			return (0);
	return (*(unsigned char *)s1 - *(unsigned char *)--s2);
}

#include "md-static-funcs.c"

/*
 * Called from assembler stub that has set up crtp (passed from crt0)
 * and dp (our __DYNAMIC).
 */
int
rtld(version, crtp, dp)
int			version;
struct crt_ldso		*crtp;
struct _dynamic		*dp;
{
	int			n;
	int			nreloc;		/* # of ld.so relocations */
	struct relocation_info	*reloc;
	struct so_debug		*ddp;
	struct so_map		*smp;

	/* Check version */
	if (		version != CRT_VERSION_BSD_2 &&
			version != CRT_VERSION_BSD_3 &&
			version != CRT_VERSION_SUN)
		return -1;

	/* Fixup __DYNAMIC structure */
	(long)dp->d_un.d_sdt += crtp->crt_ba;

	/* Divide by hand to avoid possible use of library division routine */
	for (	nreloc = 0, n = LD_RELSZ(dp);
		n > 0;
		n -= sizeof(struct relocation_info) ) nreloc++;

	
	/* Relocate ourselves */
	for (	reloc = (struct relocation_info *)(LD_REL(dp) + crtp->crt_ba);
		nreloc;
		nreloc--, reloc++) {

		register long	addr = reloc->r_address + crtp->crt_ba;

		md_relocate_simple(reloc, crtp->crt_ba, addr);
	}

	__progname = "ld.so";
	if (version >= CRT_VERSION_BSD_3)
		main_progname = crtp->crt_prog;

	/* Setup out (private) environ variable */
	environ = crtp->crt_ep;

	/* Get user and group identifiers */
	uid = getuid(); euid = geteuid();
	gid = getgid(); egid = getegid();

	careful = (uid != euid) || (gid != egid);

	if (careful) {
		unsetenv("LD_LIBRARY_PATH");
		unsetenv("LD_PRELOAD");
		unsetenv("LD_RUN_PATH"); /* In case we ever implement this */
	}

	/* Setup directory search */
	add_search_path(getenv("LD_RUN_PATH"));
	add_search_path(getenv("LD_LIBRARY_PATH"));
	if (getenv("LD_NOSTD_PATH") == NULL)
		std_search_path();

	/* Load required objects into the process address space */
	load_objects(crtp, dp);

	/* Relocate all loaded objects according to their RRS segments */
	for (smp = link_map_head; smp; smp = smp->som_next) {
		if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
			continue;
		reloc_map(smp);
	}

	/* Copy any relocated initialized data. */
	for (smp = link_map_head; smp; smp = smp->som_next) {
		if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
			continue;
		reloc_copy(smp);
	}

	/* Call any object initialization routines. */
	for (smp = link_map_head; smp; smp = smp->som_next) {
		if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
			continue;
		init_map(smp, ".init");
	}

	/* Fill in some field in main's __DYNAMIC structure */
	crtp->crt_dp->d_entry = &ld_entry;
	crtp->crt_dp->d_un.d_sdt->sdt_loaded = link_map_head->som_next;

	ddp = crtp->crt_dp->d_debug;
	ddp->dd_cc = rt_symbol_head;
	if (ddp->dd_in_debugger) {
		caddr_t	addr = (caddr_t)((long)crtp->crt_bp & (~(PAGSIZ - 1)));

		/* Set breakpoint for the benefit of debuggers */
		if (mprotect(addr, PAGSIZ,
				PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
			err(1, "Cannot set breakpoint (%s)", main_progname);
		}
		md_set_breakpoint((long)crtp->crt_bp, (long *)&ddp->dd_bpt_shadow);
		if (mprotect(addr, PAGSIZ, PROT_READ|PROT_EXEC) == -1) {
			err(1, "Cannot re-protect breakpoint (%s)",
				main_progname);
		}

		ddp->dd_bpt_addr = crtp->crt_bp;
		if (link_map_head)
			ddp->dd_sym_loaded = 1;
	}

	/* Close our file descriptor */
	(void)close(crtp->crt_ldfd);
	return 0;
}


static void
load_objects(crtp, dp)
struct crt_ldso	*crtp;
struct _dynamic	*dp;
{
	struct so_map	*smp;
	int		tracing = (int)getenv("LD_TRACE_LOADED_OBJECTS");

	/* Handle LD_PRELOAD's here */

	/* Make an entry for the main program */
	smp = alloc_link_map(main_progname, (struct sod *)0, (struct so_map *)0,
					(caddr_t)0, crtp->crt_dp);
	LM_PRIVATE(smp)->spd_refcount++;
	LM_PRIVATE(smp)->spd_flags |= RTLD_MAIN;

	/* Make an entry for ourselves */
	smp = alloc_link_map(us, (struct sod *)0, (struct so_map *)0,
					(caddr_t)crtp->crt_ba, dp);
	LM_PRIVATE(smp)->spd_refcount++;
	LM_PRIVATE(smp)->spd_flags |= RTLD_RTLD;

	for (smp = link_map_head; smp; smp = smp->som_next) {
		struct sod	*sodp;
		long		next = 0;

		if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
			continue;

		if (smp->som_dynamic)
			next = LD_NEED(smp->som_dynamic);

		while (next) {
			struct so_map	*newmap;

			sodp = (struct sod *)(LM_LDBASE(smp) + next);
			if ((newmap = map_object(sodp, smp)) == NULL) {
				if (!tracing) {
					char *name = (char *)
					    (sodp->sod_name + LM_LDBASE(smp));
					char *fmt = sodp->sod_library ?
						"%s: lib%s.so.%d.%d" :
						"%s: %s";
					err(1, fmt, main_progname, name,
						sodp->sod_major,
						sodp->sod_minor);
				}
				newmap = alloc_link_map(NULL, sodp, smp, 0, 0);
			}
			LM_PRIVATE(newmap)->spd_refcount++;
			next = sodp->sod_next;
		}
	}

	if (! tracing)
		return;

	for (smp = link_map_head; smp; smp = smp->som_next) {
		struct sod	*sodp;
		char		*name, *path;

		if ((sodp = smp->som_sod) == NULL)
			continue;
		name = sodp->sod_name + LM_LDBASE(LM_PARENT(smp));

		if ((path = smp->som_path) == NULL)
			path = "not found";

		if (sodp->sod_library)
			printf("\t-l%s.%d => %s (%p)\n", name,
					sodp->sod_major, path, smp->som_addr);
		else
			printf("\t%s => %s (%p)\n", name, path, smp->som_addr);
	}

	exit(0);
}

/*
 * Allocate a new link map for shared object NAME loaded at ADDR as a
 * result of the presence of link object LOP in the link map PARENT.
 */
	static struct so_map *
alloc_link_map(path, sodp, parent, addr, dp)
	char		*path;
	struct sod	*sodp;
	struct so_map	*parent;
	caddr_t		addr;
	struct _dynamic	*dp;
{
	struct so_map		*smp;
	struct somap_private	*smpp;

	smpp = (struct somap_private *)xmalloc(sizeof(struct somap_private));
	smp = (struct so_map *)xmalloc(sizeof(struct so_map));
	smp->som_next = NULL;
	*link_map_tail = smp;
	link_map_tail = &smp->som_next;

	smp->som_addr = addr;
	smp->som_path = strdup(path);
	smp->som_sod = sodp;
	smp->som_dynamic = dp;
	smp->som_spd = (caddr_t)smpp;

/*XXX*/	if (addr == 0) main_map = smp;

	smpp->spd_refcount = 0;
	smpp->spd_flags = 0;
	smpp->spd_parent = parent;

#ifdef SUN_COMPAT
	smpp->spd_offset =
		(addr==0 && dp && dp->d_version==LD_VERSION_SUN) ? PAGSIZ : 0;
#endif
	return smp;
}

/*
 * Map object identified by link object LOP which was found
 * in link map LMP.
 */
	static struct so_map *
map_object(sodp, smp)
	struct sod	*sodp;
	struct so_map	*smp;
{
	struct _dynamic	*dp;
	char		*path, *name = (char *)(sodp->sod_name + LM_LDBASE(smp));
	int		fd;
	caddr_t		addr;
	struct exec	hdr;
	int		usehints = 0;
	struct so_map	*p;

	if (sodp->sod_library) {
		usehints = 1;
again:
		path = rtfindlib(name, sodp->sod_major,
						sodp->sod_minor, &usehints);
		if (path == NULL) {
			errno = ENOENT;
			return NULL;
		}
	} else {
		if (careful && *name != '/') {
			errno = EACCES;
			return NULL;
		}
		path = name;
	}

	/* Check if already loaded */
	for (p = link_map_head; p; p = p->som_next)
		if (p->som_path && strcmp(p->som_path, path) == 0)
			break;

	if (p != NULL)
		return p;

	if ((fd = open(path, O_RDONLY, 0)) == -1) {
		if (usehints) {
			usehints = 0;
			goto again;
		}
		return NULL;
	}

	if (read(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) {
		(void)close(fd);
		/*errno = x;*/
		return NULL;
	}

	if (N_BADMAG(hdr)) {
		(void)close(fd);
		errno = EFTYPE;
		return NULL;
	}

	if ((addr = mmap(0, hdr.a_text + hdr.a_data,
				PROT_READ|PROT_EXEC,
				MAP_FILE|MAP_COPY, fd, 0)) == (caddr_t)-1) {
		(void)close(fd);
		return NULL;
	}

#if 0
	if (mmap(addr + hdr.a_text, hdr.a_data,
				PROT_READ|PROT_WRITE|PROT_EXEC,
				MAP_FILE|MAP_FIXED|MAP_COPY,
				fd, hdr.a_text) == (caddr_t)-1) {
		(void)close(fd);
		return NULL;
	}
#endif
	if (mprotect(addr + hdr.a_text, hdr.a_data,
	    PROT_READ|PROT_WRITE|PROT_EXEC) != 0) {
		(void)close(fd);
		return NULL;
	}

	(void)close(fd);

	fd = -1;
#ifdef NEED_DEV_ZERO
	if ((fd = open("/dev/zero", O_RDWR, 0)) == -1)
		warn("open: %s", "/dev/zero");
#endif
	if (hdr.a_bss && mmap(addr + hdr.a_text + hdr.a_data, hdr.a_bss,
				PROT_READ|PROT_WRITE|PROT_EXEC,
				MAP_ANON|MAP_FIXED|MAP_COPY,
				fd, hdr.a_text + hdr.a_data) == (caddr_t)-1)
		return NULL;

#ifdef NEED_DEV_ZERO
	close(fd);
#endif

	/* Assume _DYNAMIC is the first data item */
	dp = (struct _dynamic *)(addr+hdr.a_text);

	/* Fixup __DYNAMIC structure */
	(long)dp->d_un.d_sdt += (long)addr;

	return alloc_link_map(path, sodp, smp, addr, dp);
}

static inline void
check_text_reloc(r, smp, addr)
struct relocation_info	*r;
struct so_map		*smp;
caddr_t			addr;
{
	char	*sym;

	if (addr >= LM_ETEXT(smp))
		return;

	if (RELOC_EXTERN_P(r))
		sym = LM_STRINGS(smp) +
				LM_SYMBOL(smp, RELOC_SYMBOL(r))->nz_strx;
	else
		sym = "";

	if (getenv("LD_WARN_NON_PURE_CODE") != NULL)
		fprintf(stderr,
			"ld.so: warning: non pure code in %s at %x (%s)\n",
				smp->som_path, r->r_address, sym);

	if (smp->som_write == 0 &&
		mprotect(smp->som_addr + LM_TXTADDR(smp),
				LD_TEXTSZ(smp->som_dynamic),
				PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {

		err(1, "Cannot enable writes to %s:%s",
					main_progname, smp->som_path);
	}

	smp->som_write = 1;
}

static void
reloc_map(smp)
	struct so_map		*smp;
{
	struct _dynamic		*dp = smp->som_dynamic;
	struct relocation_info	*r = LM_REL(smp);
	struct relocation_info	*rend = r + LD_RELSZ(dp)/sizeof(*r);
	long			symbolbase = (long)LM_SYMBOL(smp, 0);
	char			*stringbase = LM_STRINGS(smp);
	int symsize		= LD_VERSION_NZLIST_P(dp->d_version) ?
					sizeof(struct nzlist) :
					sizeof(struct nlist);

	if (LD_PLTSZ(dp))
		md_fix_jmpslot(LM_PLT(smp),
				(long)LM_PLT(smp), (long)binder_entry);

	for (; r < rend; r++) {
		char	*sym;
		caddr_t	addr = smp->som_addr + r->r_address;

		check_text_reloc(r, smp, addr);

		if (RELOC_EXTERN_P(r)) {
			struct so_map	*src_map = NULL;
			struct nzlist	*p, *np;
			long	relocation = md_get_addend(r, addr);

			if (RELOC_LAZY_P(r))
				continue;

			p = (struct nzlist *)
				(symbolbase + symsize * RELOC_SYMBOL(r));

			if (p->nz_type == (N_SETV + N_EXT))
				src_map = smp;

			sym = stringbase + p->nz_strx;

			np = lookup(sym, &src_map, 0/*XXX-jumpslots!*/);
			if (np == NULL)
				errx(1, "Undefined symbol \"%s\" in %s:%s\n",
					sym, main_progname, smp->som_path);

			/*
			 * Found symbol definition.
			 * If it's in a link map, adjust value
			 * according to the load address of that map.
			 * Otherwise it's a run-time allocated common
			 * whose value is already up-to-date.
			 */
			relocation += np->nz_value;
			if (src_map)
				relocation += (long)src_map->som_addr;

			if (RELOC_PCREL_P(r))
				relocation -= (long)smp->som_addr;

			if (RELOC_COPY_P(r) && src_map) {
				(void)enter_rts(sym,
					(long)addr,
					N_DATA + N_EXT,
					src_map->som_addr + np->nz_value,
					np->nz_size, src_map);
				continue;
			}
			md_relocate(r, relocation, addr, 0);

		} else {
			md_relocate(r,
#ifdef SUN_COMPAT
				md_get_rt_segment_addend(r, addr)
#else
				md_get_addend(r, addr)
#endif
					+ (long)smp->som_addr, addr, 0);
		}

	}

	if (smp->som_write) {
		if (mprotect(smp->som_addr + LM_TXTADDR(smp),
				LD_TEXTSZ(smp->som_dynamic),
				PROT_READ|PROT_EXEC) == -1) {

			err(1, "Cannot disable writes to %s:%s\n",
						main_progname, smp->som_path);
		}
		smp->som_write = 0;
	}
}

static void
reloc_copy(smp)
	struct so_map		*smp;
{
	struct rt_symbol	*rtsp;

	for (rtsp = rt_symbol_head; rtsp; rtsp = rtsp->rt_next)
		if ((rtsp->rt_smp == NULL || rtsp->rt_smp == smp) &&
				rtsp->rt_sp->nz_type == N_DATA + N_EXT) {
			bcopy(rtsp->rt_srcaddr, (caddr_t)rtsp->rt_sp->nz_value,
							rtsp->rt_sp->nz_size);
		}
}

static void
init_map(smp, sym)
	struct so_map		*smp;
	char			*sym;
{
	struct so_map		*src_map = smp;
	struct nzlist		*np;

	np = lookup(sym, &src_map, 1);
	if (np)
		(*(void (*)())(src_map->som_addr + np->nz_value))();
}

/*
 * Run-time common symbol table.
 */

#define RTC_TABSIZE		57
static struct rt_symbol 	*rt_symtab[RTC_TABSIZE];

/*
 * Compute hash value for run-time symbol table
 */
	static inline int
hash_string(key)
	char *key;
{
	register char *cp;
	register int k;

	cp = key;
	k = 0;
	while (*cp)
		k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff;

	return k;
}

/*
 * Lookup KEY in the run-time common symbol table.
 */

	static inline struct rt_symbol *
lookup_rts(key)
	char *key;
{
	register int			hashval;
	register struct rt_symbol	*rtsp;

	/* Determine which bucket.  */

	hashval = hash_string(key) % RTC_TABSIZE;

	/* Search the bucket.  */

	for (rtsp = rt_symtab[hashval]; rtsp; rtsp = rtsp->rt_link)
		if (strcmp(key, rtsp->rt_sp->nz_name) == 0)
			return rtsp;

	return NULL;
}

	static struct rt_symbol *
enter_rts(name, value, type, srcaddr, size, smp)
	char		*name;
	long		value;
	int		type;
	caddr_t		srcaddr;
	long		size;
	struct so_map	*smp;
{
	register int			hashval;
	register struct rt_symbol	*rtsp, **rpp;

	/* Determine which bucket */
	hashval = hash_string(name) % RTC_TABSIZE;

	/* Find end of bucket */
	for (rpp = &rt_symtab[hashval]; *rpp; rpp = &(*rpp)->rt_link)
		;

	/* Allocate new common symbol */
	rtsp = (struct rt_symbol *)malloc(sizeof(struct rt_symbol));
	rtsp->rt_sp = (struct nzlist *)malloc(sizeof(struct nzlist));
	rtsp->rt_sp->nz_name = strdup(name);
	rtsp->rt_sp->nz_value = value;
	rtsp->rt_sp->nz_type = type;
	rtsp->rt_sp->nz_size = size;
	rtsp->rt_srcaddr = srcaddr;
	rtsp->rt_smp = smp;
	rtsp->rt_link = NULL;

	/* Link onto linear list as well */
	rtsp->rt_next = rt_symbol_head;
	rt_symbol_head = rtsp;

	*rpp = rtsp;

	return rtsp;
}


/*
 * Lookup NAME in the link maps. The link map producing a definition
 * is returned in SRC_MAP. If SRC_MAP is not NULL on entry the search is
 * confined to that map. If STRONG is set, the symbol returned must
 * have a proper type (used by binder()).
 */
	static struct nzlist *
lookup(name, src_map, strong)
	char		*name;
	struct so_map	**src_map;	/* IN/OUT */
	int		strong;
{
	long			common_size = 0;
	struct so_map		*smp;
	struct rt_symbol	*rtsp;

	if ((rtsp = lookup_rts(name)) != NULL)
		return rtsp->rt_sp;

	/*
	 * Search all maps for a definition of NAME
	 */
	for (smp = link_map_head; smp; smp = smp->som_next) {
		int		buckets = LD_BUCKETS(smp->som_dynamic);
		long		hashval;
		struct rrs_hash	*hp;
		char		*cp;
		struct	nzlist	*np;

		/* Some local caching */
		long		symbolbase;
		struct rrs_hash	*hashbase;
		char		*stringbase;
		int		symsize;

		if (LM_PRIVATE(smp)->spd_flags & RTLD_RTLD)
			continue;

		if (*src_map && smp != *src_map)
			continue;

restart:
		/*
		 * Compute bucket in which the symbol might be found.
		 */
		for (hashval = 0, cp = name; *cp; cp++)
			hashval = (hashval << 1) + *cp;

		hashval = (hashval & 0x7fffffff) % buckets;

		hashbase = LM_HASH(smp);
		hp = hashbase + hashval;
		if (hp->rh_symbolnum == -1)
			/* Nothing in this bucket */
			continue;

		symbolbase = (long)LM_SYMBOL(smp, 0);
		stringbase = LM_STRINGS(smp);
		symsize	= LD_VERSION_NZLIST_P(smp->som_dynamic->d_version)?
				sizeof(struct nzlist) :
				sizeof(struct nlist);
		while (hp) {
			np = (struct nzlist *)
				(symbolbase + hp->rh_symbolnum * symsize);
			cp = stringbase + np->nz_strx;
			if (strcmp(cp, name) == 0)
				break;
			if (hp->rh_next == 0)
				hp = NULL;
			else
				hp = hashbase + hp->rh_next;
		}
		if (hp == NULL)
			/* Nothing in this bucket */
			continue;

		/*
		 * We have a symbol with the name we're looking for.
		 */
		if (np->nz_type == N_INDR+N_EXT) {
			/*
			 * Next symbol gives the aliased name. Restart
			 * search with new name and confine to this map.
			 */
			name = stringbase + (++np)->nz_strx;
			*src_map = smp;
			goto restart;
		}

		if (np->nz_value == 0)
			/* It's not a definition */
			continue;

		if (np->nz_type == N_UNDF+N_EXT && np->nz_value != 0) {
			if (np->nz_other == AUX_FUNC) {
				/* It's a weak function definition */
				if (strong)
					continue;
			} else {
				/* It's a common, note value and continue search */
				if (common_size < np->nz_value)
					common_size = np->nz_value;
				continue;
			}
		}

		*src_map = smp;
		return np;
	}

	if (common_size == 0)
		/* Not found */
		return NULL;

	/*
	 * It's a common, enter into run-time common symbol table.
	 */
	rtsp = enter_rts(name, (long)calloc(1, common_size),
					N_UNDF + N_EXT, 0, common_size, NULL);

#if DEBUG
xprintf("Allocating common: %s size %d at %#x\n", name, common_size, rtsp->rt_sp->nz_value);
#endif

	return rtsp->rt_sp;
}


/*
 * This routine is called from the jumptable to resolve
 * procedure calls to shared objects.
 */
	long
binder(jsp)
	jmpslot_t	*jsp;
{
	struct so_map	*smp, *src_map = NULL;
	long		addr;
	char		*sym;
	struct nzlist	*np;
	int		index;

	/*
	 * Find the PLT map that contains JSP.
	 */
	for (smp = link_map_head; smp; smp = smp->som_next) {
		if (LM_PLT(smp) < jsp &&
			jsp < LM_PLT(smp) + LD_PLTSZ(smp->som_dynamic)/sizeof(*jsp))
			break;
	}

	if (smp == NULL)
		errx(1, "Call to binder from unknown location: %#x\n", jsp);

	index = jsp->reloc_index & JMPSLOT_RELOC_MASK;

	/* Get the local symbol this jmpslot refers to */
	sym = LM_STRINGS(smp) +
		LM_SYMBOL(smp,RELOC_SYMBOL(&LM_REL(smp)[index]))->nz_strx;

	np = lookup(sym, &src_map, 1);
	if (np == NULL)
		errx(1, "Undefined symbol \"%s\" called from %s:%s at %#x",
				sym, main_progname, smp->som_path, jsp);

	/* Fixup jmpslot so future calls transfer directly to target */
	addr = np->nz_value;
	if (src_map)
		addr += (long)src_map->som_addr;

	md_fix_jmpslot(jsp, (long)jsp, addr);

#if DEBUG
xprintf(" BINDER: %s located at = %#x in %s\n", sym, addr, src_map->som_path);
#endif
	return addr;
}


static struct hints_header	*hheader;
static struct hints_bucket	*hbuckets;
static char			*hstrtab;

#define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1)

	static void
maphints()
{
	caddr_t		addr;
	long		msize;
	int		fd;

	if ((fd = open(_PATH_LD_HINTS, O_RDONLY, 0)) == -1) {
		hheader = (struct hints_header *)-1;
		return;
	}

	msize = PAGSIZ;
	addr = mmap(0, msize, PROT_READ, MAP_FILE|MAP_COPY, fd, 0);

	if (addr == (caddr_t)-1) {
		hheader = (struct hints_header *)-1;
		return;
	}

	hheader = (struct hints_header *)addr;
	if (HH_BADMAG(*hheader)) {
		munmap(addr, msize);
		hheader = (struct hints_header *)-1;
		return;
	}

	if (hheader->hh_version != LD_HINTS_VERSION_1) {
		munmap(addr, msize);
		hheader = (struct hints_header *)-1;
		return;
	}

	if (hheader->hh_ehints > msize) {
		if (mmap(addr+msize, hheader->hh_ehints - msize,
				PROT_READ, MAP_FILE|MAP_COPY|MAP_FIXED,
				fd, msize) != (caddr_t)(addr+msize)) {

			munmap((caddr_t)hheader, msize);
			hheader = (struct hints_header *)-1;
			return;
		}
	}
	close(fd);

	hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab);
	hstrtab = (char *)(addr + hheader->hh_strtab);
}

	int
hinthash(cp, vmajor, vminor)
	char	*cp;
	int	vmajor, vminor;
{
	int	k = 0;

	while (*cp)
		k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff;

	k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff;
	k = (((k << 1) + (k >> 14)) ^ (vminor*167)) & 0x3fff;

	return k;
}

#undef major
#undef minor

	static char *
findhint(name, major, minor, preferred_path)
	char	*name;
	int	major, minor;
	char	*preferred_path;
{
	struct hints_bucket	*bp;

	bp = hbuckets + (hinthash(name, major, minor) % hheader->hh_nbucket);

	while (1) {
		/* Sanity check */
		if (bp->hi_namex >= hheader->hh_strtab_sz) {
			fprintf(stderr, "Bad name index: %#x\n", bp->hi_namex);
			break;
		}
		if (bp->hi_pathx >= hheader->hh_strtab_sz) {
			fprintf(stderr, "Bad path index: %#x\n", bp->hi_pathx);
			break;
		}

		if (strcmp(name, hstrtab + bp->hi_namex) == 0) {
			/* It's `name', check version numbers */
			if (bp->hi_major == major &&
				(bp->hi_ndewey < 2 || bp->hi_minor == minor)) {
					if (preferred_path == NULL ||
					    strcmp(preferred_path,
						hstrtab + bp->hi_pathx) == 0) {
						return hstrtab + bp->hi_pathx;
					}
			}
		}

		if (bp->hi_next == -1)
			break;

		/* Move on to next in bucket */
		bp = &hbuckets[bp->hi_next];
	}

	/* No hints available for name */
	return NULL;
}

	static char *
rtfindlib(name, major, minor, usehints)
	char	*name;
	int	major, minor;
	int	*usehints;
{
	char	*hint;
	char	*cp, *ld_path = getenv("LD_LIBRARY_PATH");

	if (hheader == NULL)
		maphints();

	if (!HINTS_VALID || !(*usehints)) {
		*usehints = 0;
		return (char *)findshlib(name, &major, &minor, 0);
	}

	if (ld_path != NULL) {
		/* Prefer paths from LD_LIBRARY_PATH */
		while ((cp = strsep(&ld_path, ":")) != NULL) {

			hint = findhint(name, major, minor, cp);
			if (ld_path)
				*(ld_path-1) = ':';
			if (hint)
				return hint;
		}
		/* Not found in hints, try directory search */
		hint = (char *)findshlib(name, &major, &minor, 0);
		if (hint)
			return hint;
	}

	/* No LD_LIBRARY_PATH or lib not found in there; check default */
	hint = findhint(name, major, minor, NULL);
	if (hint)
		return hint;

	/* No hints available for name */
	*usehints = 0;
	return (char *)findshlib(name, &major, &minor, 0);
}

static struct somap_private dlmap_private = {
		0,
		(struct so_map *)0,
		0,
#ifdef SUN_COMPAT
		0,
#endif
};

static struct so_map dlmap = {
	(caddr_t)0,
	"internal",
	(struct so_map *)0,
	(struct sod *)0,
	(caddr_t)0,
	(u_int)0,
	(struct _dynamic *)0,
	(caddr_t)&dlmap_private
};
static int dlerrno;

	static void *
__dlopen(name, mode)
	char	*name;
	int	mode;
{
	struct sod	*sodp;
	struct so_map	*smp;

	/*
	 * A NULL argument returns the current set of mapped objects.
	 */
	if (name == NULL)
		return link_map_head;

	if ((sodp = (struct sod *)malloc(sizeof(struct sod))) == NULL) {
		dlerrno = ENOMEM;
		return NULL;
	}

	sodp->sod_name = (long)strdup(name);
	sodp->sod_library = 0;
	sodp->sod_major = sodp->sod_minor = 0;

	if ((smp = map_object(sodp, &dlmap)) == NULL) {
#ifdef DEBUG
xprintf("%s: %s\n", name, strerror(errno));
#endif
		dlerrno = errno;
		return NULL;
	}
	if (LM_PRIVATE(smp)->spd_refcount++ == 0) {
		LM_PRIVATE(smp)->spd_flags |= RTLD_DL;
		reloc_map(smp);
		reloc_copy(smp);
		init_map(smp, ".init");
		init_map(smp, "_init");
	}

	return smp;
}

	static int
__dlclose(fd)
	void	*fd;
{
	struct so_map	*smp = (struct so_map *)fd;

#ifdef DEBUG
xprintf("dlclose(%s): refcount = %d\n", smp->som_path, LM_PRIVATE(smp)->spd_refcount);
#endif
	if (--LM_PRIVATE(smp)->spd_refcount != 0)
		return 0;

	/* Dismantle shared object map and descriptor */
	init_map(smp, "_fini");
#if 0
	unmap_object(smp);
	free(smp->som_sod->sod_name);
	free(smp->som_sod);
	free(smp);
#endif

	return 0;
}

	static void *
__dlsym(fd, sym)
	void	*fd;
	char	*sym;
{
	struct so_map	*smp = (struct so_map *)fd, *src_map = NULL;
	struct nzlist	*np;
	long		addr;

	/*
	 * Restrict search to passed map if dlopen()ed.
	 */
	if (LM_PRIVATE(smp)->spd_flags & RTLD_DL)
		src_map = smp;

	np = lookup(sym, &src_map, 1);
	if (np == NULL)
		return NULL;

	/* Fixup jmpslot so future calls transfer directly to target */
	addr = np->nz_value;
	if (src_map)
		addr += (long)src_map->som_addr;

	return (void *)addr;
}

	static int
__dlctl(fd, cmd, arg)
	void	*fd, *arg;
	int	cmd;
{
	switch (cmd) {
	case DL_GETERRNO:
		*(int *)arg = dlerrno;
		return 0;
	default:
		dlerrno = EOPNOTSUPP;
		return -1;
	}
	return 0;
}

void
#if __STDC__
xprintf(char *fmt, ...)
#else
xprintf(fmt, va_alist)
char	*fmt;
#endif
{
	char buf[256];
	va_list	ap;
#if __STDC__
	va_start(ap, fmt);
#else
	va_start(ap);
#endif

	vsprintf(buf, fmt, ap);
	(void)write(1, buf, strlen(buf));
	va_end(ap);
}