Fix quickworld for crossbuilding - use ln -hsf to replace 'cpu' softlink
[dragonfly.git] / libexec / rtld-elf / rtld.c
CommitLineData
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1/*-
2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: src/libexec/rtld-elf/rtld.c,v 1.43.2.15 2003/02/20 20:42:46 kan Exp $
38e4b3b6 27 * $DragonFly: src/libexec/rtld-elf/rtld.c,v 1.29 2008/01/08 00:02:04 corecode Exp $
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28 */
29
30/*
31 * Dynamic linker for ELF.
32 *
33 * John Polstra <jdp@polstra.com>.
34 */
35
36#ifndef __GNUC__
37#error "GCC is needed to compile this file"
38#endif
39
40#include <sys/param.h>
41#include <sys/mman.h>
42#include <sys/stat.h>
8ca15ec8 43#include <sys/resident.h>
bc633d63 44#include <sys/tls.h>
984263bc 45
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46#include <machine/tls.h>
47
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48#include <dlfcn.h>
49#include <err.h>
50#include <errno.h>
51#include <fcntl.h>
52#include <stdarg.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <unistd.h>
57
58#include "debug.h"
59#include "rtld.h"
60
a1eee96a 61#define PATH_RTLD "/usr/libexec/ld-elf.so.2"
8ca15ec8 62#define LD_ARY_CACHE 16
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63
64/* Types. */
65typedef void (*func_ptr_type)();
66typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
67
68/*
69 * This structure provides a reentrant way to keep a list of objects and
70 * check which ones have already been processed in some way.
71 */
72typedef struct Struct_DoneList {
73 const Obj_Entry **objs; /* Array of object pointers */
74 unsigned int num_alloc; /* Allocated size of the array */
75 unsigned int num_used; /* Number of array slots used */
76} DoneList;
77
78/*
79 * Function declarations.
80 */
984263bc 81static void die(void);
c3098c28 82static void digest_dynamic(Obj_Entry *, int);
8ca15ec8 83static const char *_getenv_ld(const char *id);
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84static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
85static Obj_Entry *dlcheck(void *);
86static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
87static bool donelist_check(DoneList *, const Obj_Entry *);
88static void errmsg_restore(char *);
89static char *errmsg_save(void);
90static void *fill_search_info(const char *, size_t, void *);
91static char *find_library(const char *, const Obj_Entry *);
b6a22d96 92static Obj_Entry *find_object(const char *);
2d6b58a8 93static Obj_Entry *find_object2(const char *, int *, struct stat *);
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94static const char *gethints(void);
95static void init_dag(Obj_Entry *);
96static void init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *);
97static void init_rtld(caddr_t);
98static void initlist_add_neededs(Needed_Entry *needed, Objlist *list);
99static void initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail,
100 Objlist *list);
101static bool is_exported(const Elf_Sym *);
102static void linkmap_add(Obj_Entry *);
103static void linkmap_delete(Obj_Entry *);
104static int load_needed_objects(Obj_Entry *);
105static int load_preload_objects(void);
106static Obj_Entry *load_object(char *);
107static void lock_check(void);
108static Obj_Entry *obj_from_addr(const void *);
109static void objlist_call_fini(Objlist *);
110static void objlist_call_init(Objlist *);
111static void objlist_clear(Objlist *);
112static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
113static void objlist_init(Objlist *);
114static void objlist_push_head(Objlist *, Obj_Entry *);
115static void objlist_push_tail(Objlist *, Obj_Entry *);
116static void objlist_remove(Objlist *, Obj_Entry *);
117static void objlist_remove_unref(Objlist *);
118static void *path_enumerate(const char *, path_enum_proc, void *);
c3098c28 119static int relocate_objects(Obj_Entry *, bool, Obj_Entry *);
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120static int rtld_dirname(const char *, char *);
121static void rtld_exit(void);
122static char *search_library_path(const char *, const char *);
123static const void **get_program_var_addr(const char *name);
124static void set_program_var(const char *, const void *);
125static const Elf_Sym *symlook_default(const char *, unsigned long hash,
126 const Obj_Entry *refobj, const Obj_Entry **defobj_out, bool in_plt);
127static const Elf_Sym *symlook_list(const char *, unsigned long,
fb0c631e 128 const Objlist *, const Obj_Entry **, bool in_plt, DoneList *);
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129static const Elf_Sym *symlook_needed(const char *, unsigned long,
130 const Needed_Entry *, const Obj_Entry **, bool in_plt, DoneList *);
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131static void trace_loaded_objects(Obj_Entry *obj);
132static void unlink_object(Obj_Entry *);
133static void unload_object(Obj_Entry *);
134static void unref_dag(Obj_Entry *);
135
136void r_debug_state(struct r_debug*, struct link_map*);
137
138/*
139 * Data declarations.
140 */
141static char *error_message; /* Message for dlerror(), or NULL */
142struct r_debug r_debug; /* for GDB; */
143static bool trust; /* False for setuid and setgid programs */
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144static const char *ld_bind_now; /* Environment variable for immediate binding */
145static const char *ld_debug; /* Environment variable for debugging */
146static const char *ld_library_path; /* Environment variable for search path */
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147static char *ld_preload; /* Environment variable for libraries to
148 load first */
8ca15ec8 149static const char *ld_tracing; /* Called from ldd(1) to print libs */
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150 /* Optional function call tracing hook */
151static int (*rtld_functrace)(const char *caller_obj,
152 const char *callee_obj,
153 const char *callee_func,
154 void *stack);
155static Obj_Entry *rtld_functrace_obj; /* Object thereof */
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156static Obj_Entry *obj_list; /* Head of linked list of shared objects */
157static Obj_Entry **obj_tail; /* Link field of last object in list */
8ca15ec8 158static Obj_Entry **preload_tail;
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159static Obj_Entry *obj_main; /* The main program shared object */
160static Obj_Entry obj_rtld; /* The dynamic linker shared object */
161static unsigned int obj_count; /* Number of objects in obj_list */
33a8b578 162static int ld_resident; /* Non-zero if resident */
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163static const char *ld_ary[LD_ARY_CACHE];
164static int ld_index;
a1eee96a 165static Objlist initlist;
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166
167static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
168 STAILQ_HEAD_INITIALIZER(list_global);
169static Objlist list_main = /* Objects loaded at program startup */
170 STAILQ_HEAD_INITIALIZER(list_main);
171static Objlist list_fini = /* Objects needing fini() calls */
172 STAILQ_HEAD_INITIALIZER(list_fini);
173
174static LockInfo lockinfo;
175
176static Elf_Sym sym_zero; /* For resolving undefined weak refs. */
177
178#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
179
180extern Elf_Dyn _DYNAMIC;
181#pragma weak _DYNAMIC
182
183/*
184 * These are the functions the dynamic linker exports to application
185 * programs. They are the only symbols the dynamic linker is willing
186 * to export from itself.
187 */
188static func_ptr_type exports[] = {
189 (func_ptr_type) &_rtld_error,
190 (func_ptr_type) &dlclose,
191 (func_ptr_type) &dlerror,
192 (func_ptr_type) &dlopen,
193 (func_ptr_type) &dlsym,
194 (func_ptr_type) &dladdr,
984263bc 195 (func_ptr_type) &dlinfo,
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196#ifdef __i386__
197 (func_ptr_type) &___tls_get_addr,
198#endif
199 (func_ptr_type) &__tls_get_addr,
a1eee96a 200 (func_ptr_type) &__tls_get_addr_tcb,
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201 (func_ptr_type) &_rtld_allocate_tls,
202 (func_ptr_type) &_rtld_free_tls,
a1eee96a 203 (func_ptr_type) &_rtld_call_init,
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204 NULL
205};
206
207/*
208 * Global declarations normally provided by crt1. The dynamic linker is
209 * not built with crt1, so we have to provide them ourselves.
210 */
211char *__progname;
212char **environ;
213
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214/*
215 * Globals to control TLS allocation.
216 */
217size_t tls_last_offset; /* Static TLS offset of last module */
218size_t tls_last_size; /* Static TLS size of last module */
219size_t tls_static_space; /* Static TLS space allocated */
220int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
221int tls_max_index = 1; /* Largest module index allocated */
222
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223/*
224 * Fill in a DoneList with an allocation large enough to hold all of
225 * the currently-loaded objects. Keep this as a macro since it calls
226 * alloca and we want that to occur within the scope of the caller.
227 */
228#define donelist_init(dlp) \
229 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
230 assert((dlp)->objs != NULL), \
231 (dlp)->num_alloc = obj_count, \
232 (dlp)->num_used = 0)
233
234static __inline void
235rlock_acquire(void)
236{
237 lockinfo.rlock_acquire(lockinfo.thelock);
238 atomic_incr_int(&lockinfo.rcount);
239 lock_check();
240}
241
242static __inline void
243wlock_acquire(void)
244{
245 lockinfo.wlock_acquire(lockinfo.thelock);
246 atomic_incr_int(&lockinfo.wcount);
247 lock_check();
248}
249
250static __inline void
251rlock_release(void)
252{
253 atomic_decr_int(&lockinfo.rcount);
254 lockinfo.rlock_release(lockinfo.thelock);
255}
256
257static __inline void
258wlock_release(void)
259{
260 atomic_decr_int(&lockinfo.wcount);
261 lockinfo.wlock_release(lockinfo.thelock);
262}
263
264/*
265 * Main entry point for dynamic linking. The first argument is the
266 * stack pointer. The stack is expected to be laid out as described
267 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
268 * Specifically, the stack pointer points to a word containing
269 * ARGC. Following that in the stack is a null-terminated sequence
270 * of pointers to argument strings. Then comes a null-terminated
271 * sequence of pointers to environment strings. Finally, there is a
272 * sequence of "auxiliary vector" entries.
273 *
274 * The second argument points to a place to store the dynamic linker's
275 * exit procedure pointer and the third to a place to store the main
276 * program's object.
277 *
278 * The return value is the main program's entry point.
279 */
a1eee96a 280
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281func_ptr_type
282_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
283{
284 Elf_Auxinfo *aux_info[AT_COUNT];
285 int i;
286 int argc;
287 char **argv;
288 char **env;
289 Elf_Auxinfo *aux;
290 Elf_Auxinfo *auxp;
291 const char *argv0;
55b88cae 292 Objlist_Entry *entry;
984263bc 293 Obj_Entry *obj;
984263bc 294
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295 ld_index = 0; /* don't use old env cache in case we are resident */
296
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297 /*
298 * On entry, the dynamic linker itself has not been relocated yet.
299 * Be very careful not to reference any global data until after
300 * init_rtld has returned. It is OK to reference file-scope statics
301 * and string constants, and to call static and global functions.
302 */
303
304 /* Find the auxiliary vector on the stack. */
305 argc = *sp++;
306 argv = (char **) sp;
307 sp += argc + 1; /* Skip over arguments and NULL terminator */
308 env = (char **) sp;
984263bc 309
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310 /*
311 * If we aren't already resident we have to dig out some more info.
312 * Note that auxinfo does not exist when we are resident.
313 */
314 if (ld_resident == 0) {
315 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
316 ;
317 aux = (Elf_Auxinfo *) sp;
318
319 /* Digest the auxiliary vector. */
320 for (i = 0; i < AT_COUNT; i++)
321 aux_info[i] = NULL;
322 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
323 if (auxp->a_type < AT_COUNT)
324 aux_info[auxp->a_type] = auxp;
325 }
326
327 /* Initialize and relocate ourselves. */
328 assert(aux_info[AT_BASE] != NULL);
329 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
330 }
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331
332 __progname = obj_rtld.path;
333 argv0 = argv[0] != NULL ? argv[0] : "(null)";
334 environ = env;
335
8ca15ec8 336 trust = (geteuid() == getuid()) && (getegid() == getgid());
984263bc 337
8ca15ec8 338 ld_bind_now = _getenv_ld("LD_BIND_NOW");
984263bc 339 if (trust) {
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MD
340 ld_debug = _getenv_ld("LD_DEBUG");
341 ld_library_path = _getenv_ld("LD_LIBRARY_PATH");
342 ld_preload = (char *)_getenv_ld("LD_PRELOAD");
984263bc 343 }
8ca15ec8 344 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS");
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345
346 if (ld_debug != NULL && *ld_debug != '\0')
347 debug = 1;
348 dbg("%s is initialized, base address = %p", __progname,
349 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
350 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
351 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
352
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353 /*
354 * If we are resident we can skip work that we have already done.
355 * Note that the stack is reset and there is no Elf_Auxinfo
356 * when running from a resident image, and the static globals setup
357 * between here and resident_skip will have already been setup.
358 */
8ca15ec8 359 if (ld_resident)
33a8b578 360 goto resident_skip1;
33a8b578 361
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362 /*
363 * Load the main program, or process its program header if it is
364 * already loaded.
365 */
366 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
367 int fd = aux_info[AT_EXECFD]->a_un.a_val;
368 dbg("loading main program");
369 obj_main = map_object(fd, argv0, NULL);
370 close(fd);
371 if (obj_main == NULL)
372 die();
373 } else { /* Main program already loaded. */
374 const Elf_Phdr *phdr;
375 int phnum;
376 caddr_t entry;
377
378 dbg("processing main program's program header");
379 assert(aux_info[AT_PHDR] != NULL);
380 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
381 assert(aux_info[AT_PHNUM] != NULL);
382 phnum = aux_info[AT_PHNUM]->a_un.a_val;
383 assert(aux_info[AT_PHENT] != NULL);
384 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
385 assert(aux_info[AT_ENTRY] != NULL);
386 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
387 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
388 die();
389 }
390
391 obj_main->path = xstrdup(argv0);
392 obj_main->mainprog = true;
393
394 /*
395 * Get the actual dynamic linker pathname from the executable if
396 * possible. (It should always be possible.) That ensures that
397 * gdb will find the right dynamic linker even if a non-standard
398 * one is being used.
399 */
400 if (obj_main->interp != NULL &&
401 strcmp(obj_main->interp, obj_rtld.path) != 0) {
402 free(obj_rtld.path);
403 obj_rtld.path = xstrdup(obj_main->interp);
b7b05c9f 404 __progname = obj_rtld.path;
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405 }
406
c3098c28 407 digest_dynamic(obj_main, 0);
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408
409 linkmap_add(obj_main);
410 linkmap_add(&obj_rtld);
411
412 /* Link the main program into the list of objects. */
413 *obj_tail = obj_main;
414 obj_tail = &obj_main->next;
415 obj_count++;
416 obj_main->refcount++;
417 /* Make sure we don't call the main program's init and fini functions. */
418 obj_main->init = obj_main->fini = NULL;
419
420 /* Initialize a fake symbol for resolving undefined weak references. */
421 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
422 sym_zero.st_shndx = SHN_ABS;
423
424 dbg("loading LD_PRELOAD libraries");
425 if (load_preload_objects() == -1)
426 die();
427 preload_tail = obj_tail;
428
429 dbg("loading needed objects");
430 if (load_needed_objects(obj_main) == -1)
431 die();
432
433 /* Make a list of all objects loaded at startup. */
434 for (obj = obj_list; obj != NULL; obj = obj->next)
435 objlist_push_tail(&list_main, obj);
436
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437resident_skip1:
438
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439 if (ld_tracing) { /* We're done */
440 trace_loaded_objects(obj_main);
441 exit(0);
442 }
443
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444 if (ld_resident) /* XXX clean this up! */
445 goto resident_skip2;
446
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447 if (getenv("LD_DUMP_REL_PRE") != NULL) {
448 dump_relocations(obj_main);
449 exit (0);
450 }
451
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452 /* setup TLS for main thread */
453 dbg("initializing initial thread local storage");
454 STAILQ_FOREACH(entry, &list_main, link) {
455 /*
456 * Allocate all the initial objects out of the static TLS
457 * block even if they didn't ask for it.
458 */
459 allocate_tls_offset(entry->obj);
460 }
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461
462 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
463
464 /*
465 * Do not try to allocate the TLS here, let libc do it itself.
466 * (crt1 for the program will call _init_tls())
467 */
55b88cae 468
6192271e 469 if (relocate_objects(obj_main,
c3098c28 470 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
6192271e 471 die();
984263bc 472
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MD
473 dbg("doing copy relocations");
474 if (do_copy_relocations(obj_main) == -1)
475 die();
1c76efe5 476
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477resident_skip2:
478
8ca15ec8 479 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) {
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480 if (exec_sys_unregister(-1) < 0) {
481 dbg("exec_sys_unregister failed %d\n", errno);
482 exit(errno);
483 }
484 dbg("exec_sys_unregister success\n");
485 exit(0);
486 }
984263bc 487
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488 if (getenv("LD_DUMP_REL_POST") != NULL) {
489 dump_relocations(obj_main);
490 exit (0);
491 }
492
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493 dbg("initializing key program variables");
494 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
495 set_program_var("environ", env);
496
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497 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) {
498 extern void resident_start(void);
499 ld_resident = 1;
500 if (exec_sys_register(resident_start) < 0) {
501 dbg("exec_sys_register failed %d\n", errno);
502 exit(errno);
503 }
504 dbg("exec_sys_register success\n");
505 exit(0);
506 }
507
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508 dbg("initializing thread locks");
509 lockdflt_init(&lockinfo);
510 lockinfo.thelock = lockinfo.lock_create(lockinfo.context);
511
512 /* Make a list of init functions to call. */
513 objlist_init(&initlist);
514 initlist_add_objects(obj_list, preload_tail, &initlist);
515
516 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
517
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518 /*
519 * Do NOT call the initlist here, give libc a chance to set up
520 * the initial TLS segment. crt1 will then call _rtld_call_init().
521 */
8ca15ec8 522
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523 dbg("transferring control to program entry point = %p", obj_main->entry);
524
525 /* Return the exit procedure and the program entry point. */
526 *exit_proc = rtld_exit;
527 *objp = obj_main;
528 return (func_ptr_type) obj_main->entry;
529}
530
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MD
531/*
532 * Call the initialization list for dynamically loaded libraries.
533 * (called from crt1.c).
534 */
535void
536_rtld_call_init(void)
537{
538 objlist_call_init(&initlist);
539 wlock_acquire();
540 objlist_clear(&initlist);
541 wlock_release();
542}
543
984263bc 544Elf_Addr
38e4b3b6 545_rtld_bind(Obj_Entry *obj, Elf_Word reloff, void *stack)
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546{
547 const Elf_Rel *rel;
548 const Elf_Sym *def;
549 const Obj_Entry *defobj;
550 Elf_Addr *where;
551 Elf_Addr target;
38e4b3b6 552 int do_reloc = 1;
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553
554 rlock_acquire();
555 if (obj->pltrel)
556 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
557 else
558 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
559
560 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
561 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
562 if (def == NULL)
563 die();
564
565 target = (Elf_Addr)(defobj->relocbase + def->st_value);
566
567 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
568 defobj->strtab + def->st_name, basename(obj->path),
569 (void *)target, basename(defobj->path));
984263bc 570 rlock_release();
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SS
571
572 /*
573 * If we have a function call tracing hook, and the
574 * hook would like to keep tracing this one function,
575 * prevent the relocation so we will wind up here
576 * the next time again.
577 *
578 * We don't want to functrace calls from the functracer
579 * to avoid recursive loops.
580 */
581 if (rtld_functrace != NULL && obj != rtld_functrace_obj) {
582 if (rtld_functrace(obj->path,
583 defobj->path,
584 defobj->strtab + def->st_name,
585 stack))
586 do_reloc = 0;
587 }
588
589 if (do_reloc)
590 reloc_jmpslot(where, target);
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591 return target;
592}
593
594/*
595 * Error reporting function. Use it like printf. If formats the message
596 * into a buffer, and sets things up so that the next call to dlerror()
597 * will return the message.
598 */
599void
600_rtld_error(const char *fmt, ...)
601{
602 static char buf[512];
603 va_list ap;
604
605 va_start(ap, fmt);
606 vsnprintf(buf, sizeof buf, fmt, ap);
607 error_message = buf;
608 va_end(ap);
609}
610
611/*
612 * Return a dynamically-allocated copy of the current error message, if any.
613 */
614static char *
615errmsg_save(void)
616{
617 return error_message == NULL ? NULL : xstrdup(error_message);
618}
619
620/*
621 * Restore the current error message from a copy which was previously saved
622 * by errmsg_save(). The copy is freed.
623 */
624static void
625errmsg_restore(char *saved_msg)
626{
627 if (saved_msg == NULL)
628 error_message = NULL;
629 else {
630 _rtld_error("%s", saved_msg);
631 free(saved_msg);
632 }
633}
634
1c76efe5 635const char *
984263bc
MD
636basename(const char *name)
637{
638 const char *p = strrchr(name, '/');
639 return p != NULL ? p + 1 : name;
640}
641
642static void
643die(void)
644{
645 const char *msg = dlerror();
646
647 if (msg == NULL)
648 msg = "Fatal error";
649 errx(1, "%s", msg);
650}
651
652/*
653 * Process a shared object's DYNAMIC section, and save the important
654 * information in its Obj_Entry structure.
655 */
656static void
c3098c28 657digest_dynamic(Obj_Entry *obj, int early)
984263bc
MD
658{
659 const Elf_Dyn *dynp;
660 Needed_Entry **needed_tail = &obj->needed;
661 const Elf_Dyn *dyn_rpath = NULL;
662 int plttype = DT_REL;
663
664 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
665 switch (dynp->d_tag) {
666
667 case DT_REL:
668 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
669 break;
670
671 case DT_RELSZ:
672 obj->relsize = dynp->d_un.d_val;
673 break;
674
675 case DT_RELENT:
676 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
677 break;
678
679 case DT_JMPREL:
680 obj->pltrel = (const Elf_Rel *)
681 (obj->relocbase + dynp->d_un.d_ptr);
682 break;
683
684 case DT_PLTRELSZ:
685 obj->pltrelsize = dynp->d_un.d_val;
686 break;
687
688 case DT_RELA:
689 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
690 break;
691
692 case DT_RELASZ:
693 obj->relasize = dynp->d_un.d_val;
694 break;
695
696 case DT_RELAENT:
697 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
698 break;
699
700 case DT_PLTREL:
701 plttype = dynp->d_un.d_val;
702 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
703 break;
704
705 case DT_SYMTAB:
706 obj->symtab = (const Elf_Sym *)
707 (obj->relocbase + dynp->d_un.d_ptr);
708 break;
709
710 case DT_SYMENT:
711 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
712 break;
713
714 case DT_STRTAB:
715 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
716 break;
717
718 case DT_STRSZ:
719 obj->strsize = dynp->d_un.d_val;
720 break;
721
722 case DT_HASH:
723 {
724 const Elf_Addr *hashtab = (const Elf_Addr *)
725 (obj->relocbase + dynp->d_un.d_ptr);
726 obj->nbuckets = hashtab[0];
727 obj->nchains = hashtab[1];
728 obj->buckets = hashtab + 2;
729 obj->chains = obj->buckets + obj->nbuckets;
730 }
731 break;
732
733 case DT_NEEDED:
734 if (!obj->rtld) {
735 Needed_Entry *nep = NEW(Needed_Entry);
736 nep->name = dynp->d_un.d_val;
737 nep->obj = NULL;
738 nep->next = NULL;
739
740 *needed_tail = nep;
741 needed_tail = &nep->next;
742 }
743 break;
744
745 case DT_PLTGOT:
746 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
747 break;
748
749 case DT_TEXTREL:
750 obj->textrel = true;
751 break;
752
753 case DT_SYMBOLIC:
754 obj->symbolic = true;
755 break;
756
757 case DT_RPATH:
167f7029 758 case DT_RUNPATH: /* XXX: process separately */
984263bc
MD
759 /*
760 * We have to wait until later to process this, because we
761 * might not have gotten the address of the string table yet.
762 */
763 dyn_rpath = dynp;
764 break;
765
766 case DT_SONAME:
767 /* Not used by the dynamic linker. */
768 break;
769
770 case DT_INIT:
771 obj->init = (InitFunc) (obj->relocbase + dynp->d_un.d_ptr);
772 break;
773
774 case DT_FINI:
775 obj->fini = (InitFunc) (obj->relocbase + dynp->d_un.d_ptr);
776 break;
777
778 case DT_DEBUG:
779 /* XXX - not implemented yet */
c3098c28
SS
780 if (!early)
781 dbg("Filling in DT_DEBUG entry");
984263bc
MD
782 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
783 break;
784
167f7029
JS
785 case DT_FLAGS:
786 if (dynp->d_un.d_val & DF_ORIGIN) {
787 obj->origin_path = xmalloc(PATH_MAX);
788 if (rtld_dirname(obj->path, obj->origin_path) == -1)
789 die();
790 }
791 if (dynp->d_un.d_val & DF_SYMBOLIC)
792 obj->symbolic = true;
793 if (dynp->d_un.d_val & DF_TEXTREL)
794 obj->textrel = true;
795 if (dynp->d_un.d_val & DF_BIND_NOW)
796 obj->bind_now = true;
797 if (dynp->d_un.d_val & DF_STATIC_TLS)
798 ;
799 break;
800
984263bc 801 default:
c3098c28
SS
802 if (!early)
803 dbg("Ignoring d_tag %d = %#x", dynp->d_tag, dynp->d_tag);
984263bc
MD
804 break;
805 }
806 }
807
808 obj->traced = false;
809
810 if (plttype == DT_RELA) {
811 obj->pltrela = (const Elf_Rela *) obj->pltrel;
812 obj->pltrel = NULL;
813 obj->pltrelasize = obj->pltrelsize;
814 obj->pltrelsize = 0;
815 }
816
817 if (dyn_rpath != NULL)
818 obj->rpath = obj->strtab + dyn_rpath->d_un.d_val;
819}
820
821/*
822 * Process a shared object's program header. This is used only for the
823 * main program, when the kernel has already loaded the main program
824 * into memory before calling the dynamic linker. It creates and
825 * returns an Obj_Entry structure.
826 */
827static Obj_Entry *
828digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
829{
830 Obj_Entry *obj;
831 const Elf_Phdr *phlimit = phdr + phnum;
832 const Elf_Phdr *ph;
833 int nsegs = 0;
834
835 obj = obj_new();
836 for (ph = phdr; ph < phlimit; ph++) {
837 switch (ph->p_type) {
838
839 case PT_PHDR:
840 if ((const Elf_Phdr *)ph->p_vaddr != phdr) {
841 _rtld_error("%s: invalid PT_PHDR", path);
842 return NULL;
843 }
844 obj->phdr = (const Elf_Phdr *) ph->p_vaddr;
845 obj->phsize = ph->p_memsz;
846 break;
847
848 case PT_INTERP:
849 obj->interp = (const char *) ph->p_vaddr;
850 break;
851
852 case PT_LOAD:
853 if (nsegs == 0) { /* First load segment */
854 obj->vaddrbase = trunc_page(ph->p_vaddr);
855 obj->mapbase = (caddr_t) obj->vaddrbase;
856 obj->relocbase = obj->mapbase - obj->vaddrbase;
857 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
858 obj->vaddrbase;
859 } else { /* Last load segment */
860 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
861 obj->vaddrbase;
862 }
863 nsegs++;
864 break;
865
866 case PT_DYNAMIC:
867 obj->dynamic = (const Elf_Dyn *) ph->p_vaddr;
868 break;
55b88cae
DX
869
870 case PT_TLS:
871 obj->tlsindex = 1;
872 obj->tlssize = ph->p_memsz;
873 obj->tlsalign = ph->p_align;
874 obj->tlsinitsize = ph->p_filesz;
875 obj->tlsinit = (void*) ph->p_vaddr;
876 break;
984263bc
MD
877 }
878 }
879 if (nsegs < 1) {
880 _rtld_error("%s: too few PT_LOAD segments", path);
881 return NULL;
882 }
883
884 obj->entry = entry;
885 return obj;
886}
887
888static Obj_Entry *
889dlcheck(void *handle)
890{
891 Obj_Entry *obj;
892
893 for (obj = obj_list; obj != NULL; obj = obj->next)
894 if (obj == (Obj_Entry *) handle)
895 break;
896
897 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
898 _rtld_error("Invalid shared object handle %p", handle);
899 return NULL;
900 }
901 return obj;
902}
903
904/*
905 * If the given object is already in the donelist, return true. Otherwise
906 * add the object to the list and return false.
907 */
908static bool
909donelist_check(DoneList *dlp, const Obj_Entry *obj)
910{
911 unsigned int i;
912
913 for (i = 0; i < dlp->num_used; i++)
914 if (dlp->objs[i] == obj)
915 return true;
916 /*
917 * Our donelist allocation should always be sufficient. But if
918 * our threads locking isn't working properly, more shared objects
919 * could have been loaded since we allocated the list. That should
920 * never happen, but we'll handle it properly just in case it does.
921 */
922 if (dlp->num_used < dlp->num_alloc)
923 dlp->objs[dlp->num_used++] = obj;
924 return false;
925}
926
927/*
928 * Hash function for symbol table lookup. Don't even think about changing
929 * this. It is specified by the System V ABI.
930 */
931unsigned long
932elf_hash(const char *name)
933{
934 const unsigned char *p = (const unsigned char *) name;
935 unsigned long h = 0;
936 unsigned long g;
937
938 while (*p != '\0') {
939 h = (h << 4) + *p++;
940 if ((g = h & 0xf0000000) != 0)
941 h ^= g >> 24;
942 h &= ~g;
943 }
944 return h;
945}
946
947/*
948 * Find the library with the given name, and return its full pathname.
949 * The returned string is dynamically allocated. Generates an error
950 * message and returns NULL if the library cannot be found.
951 *
952 * If the second argument is non-NULL, then it refers to an already-
953 * loaded shared object, whose library search path will be searched.
954 *
955 * The search order is:
984263bc 956 * LD_LIBRARY_PATH
4e390e27 957 * rpath in the referencing file
984263bc
MD
958 * ldconfig hints
959 * /usr/lib
960 */
961static char *
962find_library(const char *name, const Obj_Entry *refobj)
963{
964 char *pathname;
965
966 if (strchr(name, '/') != NULL) { /* Hard coded pathname */
967 if (name[0] != '/' && !trust) {
968 _rtld_error("Absolute pathname required for shared object \"%s\"",
969 name);
970 return NULL;
971 }
972 return xstrdup(name);
973 }
974
975 dbg(" Searching for \"%s\"", name);
976
977 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
978 (refobj != NULL &&
979 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
980 (pathname = search_library_path(name, gethints())) != NULL ||
981 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
982 return pathname;
983
446c0d3a
JS
984 if(refobj != NULL && refobj->path != NULL) {
985 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
986 name, basename(refobj->path));
987 } else {
988 _rtld_error("Shared object \"%s\" not found", name);
989 }
984263bc
MD
990 return NULL;
991}
992
993/*
994 * Given a symbol number in a referencing object, find the corresponding
995 * definition of the symbol. Returns a pointer to the symbol, or NULL if
996 * no definition was found. Returns a pointer to the Obj_Entry of the
997 * defining object via the reference parameter DEFOBJ_OUT.
998 */
999const Elf_Sym *
1000find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1001 const Obj_Entry **defobj_out, bool in_plt, SymCache *cache)
1002{
1003 const Elf_Sym *ref;
1004 const Elf_Sym *def;
1005 const Obj_Entry *defobj;
1006 const char *name;
1007 unsigned long hash;
1008
1009 /*
1010 * If we have already found this symbol, get the information from
1011 * the cache.
1012 */
1013 if (symnum >= refobj->nchains)
1014 return NULL; /* Bad object */
1015 if (cache != NULL && cache[symnum].sym != NULL) {
1016 *defobj_out = cache[symnum].obj;
1017 return cache[symnum].sym;
1018 }
1019
1020 ref = refobj->symtab + symnum;
1021 name = refobj->strtab + ref->st_name;
984263bc
MD
1022 defobj = NULL;
1023
0e588128
SS
1024 /*
1025 * We don't have to do a full scale lookup if the symbol is local.
1026 * We know it will bind to the instance in this load module; to
1027 * which we already have a pointer (ie ref). By not doing a lookup,
1028 * we not only improve performance, but it also avoids unresolvable
1029 * symbols when local symbols are not in the hash table.
1030 *
1031 * This might occur for TLS module relocations, which simply use
1032 * symbol 0.
1033 */
1034 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1035 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
c3098c28
SS
1036 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1037 symnum);
1038 }
0e588128
SS
1039 hash = elf_hash(name);
1040 def = symlook_default(name, hash, refobj, &defobj, in_plt);
1041 } else {
c3098c28
SS
1042 def = ref;
1043 defobj = refobj;
0e588128 1044 }
984263bc
MD
1045
1046 /*
1047 * If we found no definition and the reference is weak, treat the
1048 * symbol as having the value zero.
1049 */
1050 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1051 def = &sym_zero;
1052 defobj = obj_main;
1053 }
1054
1055 if (def != NULL) {
1056 *defobj_out = defobj;
1057 /* Record the information in the cache to avoid subsequent lookups. */
1058 if (cache != NULL) {
1059 cache[symnum].sym = def;
1060 cache[symnum].obj = defobj;
1061 }
1062 } else
1063 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1064 return def;
1065}
1066
1067/*
1068 * Return the search path from the ldconfig hints file, reading it if
1069 * necessary. Returns NULL if there are problems with the hints file,
1070 * or if the search path there is empty.
1071 */
1072static const char *
1073gethints(void)
1074{
1075 static char *hints;
1076
1077 if (hints == NULL) {
1078 int fd;
1079 struct elfhints_hdr hdr;
1080 char *p;
1081
1082 /* Keep from trying again in case the hints file is bad. */
1083 hints = "";
1084
1085 if ((fd = open(_PATH_ELF_HINTS, O_RDONLY)) == -1)
1086 return NULL;
1087 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1088 hdr.magic != ELFHINTS_MAGIC ||
1089 hdr.version != 1) {
1090 close(fd);
1091 return NULL;
1092 }
1093 p = xmalloc(hdr.dirlistlen + 1);
1094 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1095 read(fd, p, hdr.dirlistlen + 1) != hdr.dirlistlen + 1) {
1096 free(p);
1097 close(fd);
1098 return NULL;
1099 }
1100 hints = p;
1101 close(fd);
1102 }
1103 return hints[0] != '\0' ? hints : NULL;
1104}
1105
1106static void
1107init_dag(Obj_Entry *root)
1108{
1109 DoneList donelist;
1110
1111 donelist_init(&donelist);
1112 init_dag1(root, root, &donelist);
1113}
1114
1115static void
1116init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1117{
1118 const Needed_Entry *needed;
1119
1120 if (donelist_check(dlp, obj))
1121 return;
1122 objlist_push_tail(&obj->dldags, root);
1123 objlist_push_tail(&root->dagmembers, obj);
1124 for (needed = obj->needed; needed != NULL; needed = needed->next)
1125 if (needed->obj != NULL)
1126 init_dag1(root, needed->obj, dlp);
1127}
1128
1129/*
1130 * Initialize the dynamic linker. The argument is the address at which
1131 * the dynamic linker has been mapped into memory. The primary task of
1132 * this function is to relocate the dynamic linker.
1133 */
1134static void
1135init_rtld(caddr_t mapbase)
1136{
c3098c28
SS
1137 Obj_Entry objtmp; /* Temporary rtld object */
1138
984263bc
MD
1139 /*
1140 * Conjure up an Obj_Entry structure for the dynamic linker.
1141 *
c3098c28
SS
1142 * The "path" member can't be initialized yet because string constatns
1143 * cannot yet be acessed. Below we will set it correctly.
984263bc 1144 */
c3098c28
SS
1145 objtmp.path = NULL;
1146 objtmp.rtld = true;
1147 objtmp.mapbase = mapbase;
984263bc 1148#ifdef PIC
c3098c28 1149 objtmp.relocbase = mapbase;
984263bc
MD
1150#endif
1151 if (&_DYNAMIC != 0) {
c3098c28
SS
1152 objtmp.dynamic = rtld_dynamic(&objtmp);
1153 digest_dynamic(&objtmp, 1);
1154 assert(objtmp.needed == NULL);
1155 assert(!objtmp.textrel);
984263bc
MD
1156
1157 /*
1158 * Temporarily put the dynamic linker entry into the object list, so
1159 * that symbols can be found.
1160 */
984263bc 1161
c3098c28 1162 relocate_objects(&objtmp, true, &objtmp);
984263bc
MD
1163 }
1164
c3098c28 1165 /* Initialize the object list. */
984263bc 1166 obj_tail = &obj_list;
c3098c28
SS
1167
1168 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1169 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
984263bc
MD
1170
1171 /* Replace the path with a dynamically allocated copy. */
c3098c28 1172 obj_rtld.path = xstrdup(PATH_RTLD);
984263bc
MD
1173
1174 r_debug.r_brk = r_debug_state;
1175 r_debug.r_state = RT_CONSISTENT;
1176}
1177
1178/*
1179 * Add the init functions from a needed object list (and its recursive
1180 * needed objects) to "list". This is not used directly; it is a helper
1181 * function for initlist_add_objects(). The write lock must be held
1182 * when this function is called.
1183 */
1184static void
1185initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1186{
1187 /* Recursively process the successor needed objects. */
1188 if (needed->next != NULL)
1189 initlist_add_neededs(needed->next, list);
1190
1191 /* Process the current needed object. */
1192 if (needed->obj != NULL)
1193 initlist_add_objects(needed->obj, &needed->obj->next, list);
1194}
1195
1196/*
1197 * Scan all of the DAGs rooted in the range of objects from "obj" to
1198 * "tail" and add their init functions to "list". This recurses over
1199 * the DAGs and ensure the proper init ordering such that each object's
1200 * needed libraries are initialized before the object itself. At the
1201 * same time, this function adds the objects to the global finalization
1202 * list "list_fini" in the opposite order. The write lock must be
1203 * held when this function is called.
1204 */
1205static void
1206initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1207{
1208 if (obj->init_done)
1209 return;
1210 obj->init_done = true;
1211
1212 /* Recursively process the successor objects. */
1213 if (&obj->next != tail)
1214 initlist_add_objects(obj->next, tail, list);
1215
1216 /* Recursively process the needed objects. */
1217 if (obj->needed != NULL)
1218 initlist_add_neededs(obj->needed, list);
1219
1220 /* Add the object to the init list. */
1221 if (obj->init != NULL)
1222 objlist_push_tail(list, obj);
1223
1224 /* Add the object to the global fini list in the reverse order. */
1225 if (obj->fini != NULL)
1226 objlist_push_head(&list_fini, obj);
1227}
1228
1229static bool
1230is_exported(const Elf_Sym *def)
1231{
1232 func_ptr_type value;
1233 const func_ptr_type *p;
1234
1235 value = (func_ptr_type)(obj_rtld.relocbase + def->st_value);
1236 for (p = exports; *p != NULL; p++)
1237 if (*p == value)
1238 return true;
1239 return false;
1240}
1241
1242/*
1243 * Given a shared object, traverse its list of needed objects, and load
1244 * each of them. Returns 0 on success. Generates an error message and
1245 * returns -1 on failure.
1246 */
1247static int
1248load_needed_objects(Obj_Entry *first)
1249{
1250 Obj_Entry *obj;
1251
1252 for (obj = first; obj != NULL; obj = obj->next) {
1253 Needed_Entry *needed;
1254
1255 for (needed = obj->needed; needed != NULL; needed = needed->next) {
1256 const char *name = obj->strtab + needed->name;
1257 char *path = find_library(name, obj);
1258
1259 needed->obj = NULL;
1260 if (path == NULL && !ld_tracing)
1261 return -1;
1262
1263 if (path) {
1264 needed->obj = load_object(path);
1265 if (needed->obj == NULL && !ld_tracing)
1266 return -1; /* XXX - cleanup */
1267 }
1268 }
1269 }
1270
1271 return 0;
1272}
1273
38e4b3b6
SS
1274#define RTLD_FUNCTRACE "_rtld_functrace"
1275
984263bc
MD
1276static int
1277load_preload_objects(void)
1278{
1279 char *p = ld_preload;
1280 static const char delim[] = " \t:;";
1281
1282 if (p == NULL)
eecd52b2 1283 return 0;
984263bc
MD
1284
1285 p += strspn(p, delim);
1286 while (*p != '\0') {
1287 size_t len = strcspn(p, delim);
1288 char *path;
1289 char savech;
38e4b3b6
SS
1290 Obj_Entry *obj;
1291 const Elf_Sym *sym;
984263bc
MD
1292
1293 savech = p[len];
1294 p[len] = '\0';
1295 if ((path = find_library(p, NULL)) == NULL)
1296 return -1;
38e4b3b6
SS
1297 obj = load_object(path);
1298 if (obj == NULL)
984263bc
MD
1299 return -1; /* XXX - cleanup */
1300 p[len] = savech;
1301 p += len;
1302 p += strspn(p, delim);
38e4b3b6
SS
1303
1304 /* Check for the magic tracing function */
1305 sym = symlook_obj(RTLD_FUNCTRACE, elf_hash(RTLD_FUNCTRACE), obj, true);
1306 if (sym != NULL) {
1307 rtld_functrace = (void *)(obj->relocbase + sym->st_value);
1308 rtld_functrace_obj = obj;
1309 }
984263bc
MD
1310 }
1311 return 0;
1312}
1313
b6a22d96 1314/*
2d6b58a8 1315 * Returns a pointer to the Obj_Entry for the object with the given path.
b6a22d96
JS
1316 * Returns NULL if no matching object was found.
1317 */
1318static Obj_Entry *
1319find_object(const char *path)
1320{
1321 Obj_Entry *obj;
1322
1323 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1324 if (strcmp(obj->path, path) == 0)
1325 return(obj);
1326 }
1327 return(NULL);
1328}
1329
2d6b58a8
JS
1330/*
1331 * Returns a pointer to the Obj_Entry for the object matching device and
1332 * inode of the given path. If no matching object was found, the descriptor
1333 * is returned in fd.
1334 * Returns with obj == NULL && fd == -1 on error.
1335 */
1336static Obj_Entry *
1337find_object2(const char *path, int *fd, struct stat *sb)
1338{
1339 Obj_Entry *obj;
1340
1341 if ((*fd = open(path, O_RDONLY)) == -1) {
1342 _rtld_error("Cannot open \"%s\"", path);
1343 return(NULL);
1344 }
1345
1346 if (fstat(*fd, sb) == -1) {
1347 _rtld_error("Cannot fstat \"%s\"", path);
1348 close(*fd);
1349 *fd = -1;
1350 return NULL;
1351 }
1352
1353 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1354 if (obj->ino == sb->st_ino && obj->dev == sb->st_dev) {
1355 close(*fd);
1356 break;
1357 }
1358 }
1359
1360 return(obj);
1361}
1362
984263bc
MD
1363/*
1364 * Load a shared object into memory, if it is not already loaded. The
1365 * argument must be a string allocated on the heap. This function assumes
1366 * responsibility for freeing it when necessary.
1367 *
1368 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1369 * on failure.
1370 */
1371static Obj_Entry *
1372load_object(char *path)
1373{
1374 Obj_Entry *obj;
1375 int fd = -1;
1376 struct stat sb;
1377
b6a22d96 1378 obj = find_object(path);
2d6b58a8 1379 if (obj != NULL) {
588c673f 1380 obj->refcount++;
2d6b58a8
JS
1381 free(path);
1382 return(obj);
1383 }
984263bc 1384
2d6b58a8 1385 obj = find_object2(path, &fd, &sb);
588c673f
JS
1386 if (obj != NULL) {
1387 obj->refcount++;
2d6b58a8
JS
1388 free(path);
1389 return(obj);
588c673f
JS
1390 } else if (fd == -1) {
1391 free(path);
1392 return(NULL);
984263bc
MD
1393 }
1394
2d6b58a8
JS
1395 dbg("loading \"%s\"", path);
1396 obj = map_object(fd, path, &sb);
1397 close(fd);
1398 if (obj == NULL) {
1399 free(path);
1400 return NULL;
1401 }
984263bc 1402
2d6b58a8 1403 obj->path = path;
c3098c28 1404 digest_dynamic(obj, 0);
984263bc 1405
2d6b58a8
JS
1406 *obj_tail = obj;
1407 obj_tail = &obj->next;
1408 obj_count++;
1409 linkmap_add(obj); /* for GDB & dlinfo() */
984263bc 1410
2d6b58a8
JS
1411 dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1,
1412 obj->path);
1413 if (obj->textrel)
1414 dbg(" WARNING: %s has impure text", obj->path);
984263bc
MD
1415
1416 obj->refcount++;
1417 return obj;
1418}
1419
1420/*
1421 * Check for locking violations and die if one is found.
1422 */
1423static void
1424lock_check(void)
1425{
1426 int rcount, wcount;
1427
1428 rcount = lockinfo.rcount;
1429 wcount = lockinfo.wcount;
1430 assert(rcount >= 0);
1431 assert(wcount >= 0);
1432 if (wcount > 1 || (wcount != 0 && rcount != 0)) {
1433 _rtld_error("Application locking error: %d readers and %d writers"
1434 " in dynamic linker. See DLLOCKINIT(3) in manual pages.",
1435 rcount, wcount);
1436 die();
1437 }
1438}
1439
1440static Obj_Entry *
1441obj_from_addr(const void *addr)
1442{
984263bc
MD
1443 Obj_Entry *obj;
1444
984263bc 1445 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc
MD
1446 if (addr < (void *) obj->mapbase)
1447 continue;
c6873e56 1448 if (addr < (void *) (obj->mapbase + obj->mapsize))
984263bc
MD
1449 return obj;
1450 }
1451 return NULL;
1452}
1453
1454/*
1455 * Call the finalization functions for each of the objects in "list"
1456 * which are unreferenced. All of the objects are expected to have
1457 * non-NULL fini functions.
1458 */
1459static void
1460objlist_call_fini(Objlist *list)
1461{
1462 Objlist_Entry *elm;
1463 char *saved_msg;
1464
1465 /*
1466 * Preserve the current error message since a fini function might
1467 * call into the dynamic linker and overwrite it.
1468 */
1469 saved_msg = errmsg_save();
1470 STAILQ_FOREACH(elm, list, link) {
1471 if (elm->obj->refcount == 0) {
1472 dbg("calling fini function for %s", elm->obj->path);
1473 (*elm->obj->fini)();
1474 }
1475 }
1476 errmsg_restore(saved_msg);
1477}
1478
1479/*
1480 * Call the initialization functions for each of the objects in
1481 * "list". All of the objects are expected to have non-NULL init
1482 * functions.
1483 */
1484static void
1485objlist_call_init(Objlist *list)
1486{
1487 Objlist_Entry *elm;
1488 char *saved_msg;
1489
1490 /*
1491 * Preserve the current error message since an init function might
1492 * call into the dynamic linker and overwrite it.
1493 */
1494 saved_msg = errmsg_save();
1495 STAILQ_FOREACH(elm, list, link) {
1496 dbg("calling init function for %s", elm->obj->path);
1497 (*elm->obj->init)();
1498 }
1499 errmsg_restore(saved_msg);
1500}
1501
1502static void
1503objlist_clear(Objlist *list)
1504{
1505 Objlist_Entry *elm;
1506
1507 while (!STAILQ_EMPTY(list)) {
1508 elm = STAILQ_FIRST(list);
1509 STAILQ_REMOVE_HEAD(list, link);
1510 free(elm);
1511 }
1512}
1513
1514static Objlist_Entry *
1515objlist_find(Objlist *list, const Obj_Entry *obj)
1516{
1517 Objlist_Entry *elm;
1518
1519 STAILQ_FOREACH(elm, list, link)
1520 if (elm->obj == obj)
1521 return elm;
1522 return NULL;
1523}
1524
1525static void
1526objlist_init(Objlist *list)
1527{
1528 STAILQ_INIT(list);
1529}
1530
1531static void
1532objlist_push_head(Objlist *list, Obj_Entry *obj)
1533{
1534 Objlist_Entry *elm;
1535
1536 elm = NEW(Objlist_Entry);
1537 elm->obj = obj;
1538 STAILQ_INSERT_HEAD(list, elm, link);
1539}
1540
1541static void
1542objlist_push_tail(Objlist *list, Obj_Entry *obj)
1543{
1544 Objlist_Entry *elm;
1545
1546 elm = NEW(Objlist_Entry);
1547 elm->obj = obj;
1548 STAILQ_INSERT_TAIL(list, elm, link);
1549}
1550
1551static void
1552objlist_remove(Objlist *list, Obj_Entry *obj)
1553{
1554 Objlist_Entry *elm;
1555
1556 if ((elm = objlist_find(list, obj)) != NULL) {
1557 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1558 free(elm);
1559 }
1560}
1561
1562/*
1563 * Remove all of the unreferenced objects from "list".
1564 */
1565static void
1566objlist_remove_unref(Objlist *list)
1567{
1568 Objlist newlist;
1569 Objlist_Entry *elm;
1570
1571 STAILQ_INIT(&newlist);
1572 while (!STAILQ_EMPTY(list)) {
1573 elm = STAILQ_FIRST(list);
1574 STAILQ_REMOVE_HEAD(list, link);
1575 if (elm->obj->refcount == 0)
1576 free(elm);
1577 else
1578 STAILQ_INSERT_TAIL(&newlist, elm, link);
1579 }
1580 *list = newlist;
1581}
1582
1583/*
1584 * Relocate newly-loaded shared objects. The argument is a pointer to
1585 * the Obj_Entry for the first such object. All objects from the first
1586 * to the end of the list of objects are relocated. Returns 0 on success,
1587 * or -1 on failure.
1588 */
1589static int
c3098c28 1590relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
984263bc
MD
1591{
1592 Obj_Entry *obj;
1593
1594 for (obj = first; obj != NULL; obj = obj->next) {
c3098c28 1595 if (obj != rtldobj)
984263bc
MD
1596 dbg("relocating \"%s\"", obj->path);
1597 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1598 obj->symtab == NULL || obj->strtab == NULL) {
1599 _rtld_error("%s: Shared object has no run-time symbol table",
1600 obj->path);
1601 return -1;
1602 }
1603
1604 if (obj->textrel) {
1605 /* There are relocations to the write-protected text segment. */
1606 if (mprotect(obj->mapbase, obj->textsize,
1607 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1608 _rtld_error("%s: Cannot write-enable text segment: %s",
1609 obj->path, strerror(errno));
1610 return -1;
1611 }
1612 }
1613
1614 /* Process the non-PLT relocations. */
c3098c28 1615 if (reloc_non_plt(obj, rtldobj))
984263bc
MD
1616 return -1;
1617
4b89341e
MD
1618 /*
1619 * Reprotect the text segment. Make sure it is included in the
1620 * core dump since we modified it. This unfortunately causes the
1621 * entire text segment to core-out but we don't have much of a
1622 * choice. We could try to only reenable core dumps on pages
1623 * in which relocations occured but that is likely most of the text
1624 * pages anyway, and even that would not work because the rest of
1625 * the text pages would wind up as a read-only OBJT_DEFAULT object
1626 * (created due to our modifications) backed by the original OBJT_VNODE
1627 * object, and the ELF coredump code is currently only able to dump
1628 * vnode records for pure vnode-backed mappings, not vnode backings
1629 * to memory objects.
1630 */
1631 if (obj->textrel) {
1632 madvise(obj->mapbase, obj->textsize, MADV_CORE);
984263bc
MD
1633 if (mprotect(obj->mapbase, obj->textsize,
1634 PROT_READ|PROT_EXEC) == -1) {
1635 _rtld_error("%s: Cannot write-protect text segment: %s",
1636 obj->path, strerror(errno));
1637 return -1;
1638 }
1639 }
1640
1641 /* Process the PLT relocations. */
1642 if (reloc_plt(obj) == -1)
1643 return -1;
1644 /* Relocate the jump slots if we are doing immediate binding. */
167f7029 1645 if (obj->bind_now || bind_now)
984263bc
MD
1646 if (reloc_jmpslots(obj) == -1)
1647 return -1;
1648
1649
1650 /*
1651 * Set up the magic number and version in the Obj_Entry. These
1652 * were checked in the crt1.o from the original ElfKit, so we
1653 * set them for backward compatibility.
1654 */
1655 obj->magic = RTLD_MAGIC;
1656 obj->version = RTLD_VERSION;
1657
1658 /* Set the special PLT or GOT entries. */
1659 init_pltgot(obj);
1660 }
1661
1662 return 0;
1663}
1664
1665/*
1666 * Cleanup procedure. It will be called (by the atexit mechanism) just
1667 * before the process exits.
1668 */
1669static void
1670rtld_exit(void)
1671{
1672 Obj_Entry *obj;
1673
1674 dbg("rtld_exit()");
1675 /* Clear all the reference counts so the fini functions will be called. */
1676 for (obj = obj_list; obj != NULL; obj = obj->next)
1677 obj->refcount = 0;
1678 objlist_call_fini(&list_fini);
1679 /* No need to remove the items from the list, since we are exiting. */
1680}
1681
1682static void *
1683path_enumerate(const char *path, path_enum_proc callback, void *arg)
1684{
1685 if (path == NULL)
1686 return (NULL);
1687
1688 path += strspn(path, ":;");
1689 while (*path != '\0') {
1690 size_t len;
1691 char *res;
1692
1693 len = strcspn(path, ":;");
1694 res = callback(path, len, arg);
1695
1696 if (res != NULL)
1697 return (res);
1698
1699 path += len;
1700 path += strspn(path, ":;");
1701 }
1702
1703 return (NULL);
1704}
1705
1706struct try_library_args {
1707 const char *name;
1708 size_t namelen;
1709 char *buffer;
1710 size_t buflen;
1711};
1712
1713static void *
1714try_library_path(const char *dir, size_t dirlen, void *param)
1715{
1716 struct try_library_args *arg;
1717
1718 arg = param;
1719 if (*dir == '/' || trust) {
1720 char *pathname;
1721
1722 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
1723 return (NULL);
1724
1725 pathname = arg->buffer;
1726 strncpy(pathname, dir, dirlen);
1727 pathname[dirlen] = '/';
1728 strcpy(pathname + dirlen + 1, arg->name);
1729
1730 dbg(" Trying \"%s\"", pathname);
1731 if (access(pathname, F_OK) == 0) { /* We found it */
1732 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
1733 strcpy(pathname, arg->buffer);
1734 return (pathname);
1735 }
1736 }
1737 return (NULL);
1738}
1739
1740static char *
1741search_library_path(const char *name, const char *path)
1742{
1743 char *p;
1744 struct try_library_args arg;
1745
1746 if (path == NULL)
1747 return NULL;
1748
1749 arg.name = name;
1750 arg.namelen = strlen(name);
1751 arg.buffer = xmalloc(PATH_MAX);
1752 arg.buflen = PATH_MAX;
1753
1754 p = path_enumerate(path, try_library_path, &arg);
1755
1756 free(arg.buffer);
1757
1758 return (p);
1759}
1760
1761int
1762dlclose(void *handle)
1763{
1764 Obj_Entry *root;
1765
1766 wlock_acquire();
1767 root = dlcheck(handle);
1768 if (root == NULL) {
1769 wlock_release();
1770 return -1;
1771 }
1772
1773 /* Unreference the object and its dependencies. */
1774 root->dl_refcount--;
1775 unref_dag(root);
1776
1777 if (root->refcount == 0) {
1778 /*
1779 * The object is no longer referenced, so we must unload it.
1780 * First, call the fini functions with no locks held.
1781 */
1782 wlock_release();
1783 objlist_call_fini(&list_fini);
1784 wlock_acquire();
1785 objlist_remove_unref(&list_fini);
1786
1787 /* Finish cleaning up the newly-unreferenced objects. */
1788 GDB_STATE(RT_DELETE,&root->linkmap);
1789 unload_object(root);
1790 GDB_STATE(RT_CONSISTENT,NULL);
1791 }
1792 wlock_release();
1793 return 0;
1794}
1795
1796const char *
1797dlerror(void)
1798{
1799 char *msg = error_message;
1800 error_message = NULL;
1801 return msg;
1802}
1803
984263bc
MD
1804void *
1805dlopen(const char *name, int mode)
1806{
1807 Obj_Entry **old_obj_tail;
1808 Obj_Entry *obj;
1809 Objlist initlist;
1810 int result;
1811
1812 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
1813 if (ld_tracing != NULL)
1814 environ = (char **)*get_program_var_addr("environ");
1815
1816 objlist_init(&initlist);
1817
1818 wlock_acquire();
1819 GDB_STATE(RT_ADD,NULL);
1820
1821 old_obj_tail = obj_tail;
1822 obj = NULL;
1823 if (name == NULL) {
1824 obj = obj_main;
1825 obj->refcount++;
1826 } else {
1827 char *path = find_library(name, obj_main);
1828 if (path != NULL)
1829 obj = load_object(path);
1830 }
1831
1832 if (obj) {
1833 obj->dl_refcount++;
8ca15ec8 1834 if ((mode & RTLD_GLOBAL) && objlist_find(&list_global, obj) == NULL)
984263bc
MD
1835 objlist_push_tail(&list_global, obj);
1836 mode &= RTLD_MODEMASK;
1837 if (*old_obj_tail != NULL) { /* We loaded something new. */
1838 assert(*old_obj_tail == obj);
1839
1840 result = load_needed_objects(obj);
1841 if (result != -1 && ld_tracing)
1842 goto trace;
1843
1844 if (result == -1 ||
c3098c28
SS
1845 (init_dag(obj), relocate_objects(obj, mode == RTLD_NOW,
1846 &obj_rtld)) == -1) {
984263bc
MD
1847 obj->dl_refcount--;
1848 unref_dag(obj);
1849 if (obj->refcount == 0)
1850 unload_object(obj);
1851 obj = NULL;
1852 } else {
1853 /* Make list of init functions to call. */
1854 initlist_add_objects(obj, &obj->next, &initlist);
1855 }
1856 } else if (ld_tracing)
1857 goto trace;
1858 }
1859
1860 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
1861
1862 /* Call the init functions with no locks held. */
1863 wlock_release();
1864 objlist_call_init(&initlist);
1865 wlock_acquire();
1866 objlist_clear(&initlist);
1867 wlock_release();
1868 return obj;
1869trace:
1870 trace_loaded_objects(obj);
1871 wlock_release();
1872 exit(0);
1873}
1874
1875void *
1876dlsym(void *handle, const char *name)
1877{
1878 const Obj_Entry *obj;
1879 unsigned long hash;
1880 const Elf_Sym *def;
1881 const Obj_Entry *defobj;
1882
1883 hash = elf_hash(name);
1884 def = NULL;
1885 defobj = NULL;
1886
1887 rlock_acquire();
1888 if (handle == NULL || handle == RTLD_NEXT ||
1889 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
1890 void *retaddr;
1891
1892 retaddr = __builtin_return_address(0); /* __GNUC__ only */
1893 if ((obj = obj_from_addr(retaddr)) == NULL) {
1894 _rtld_error("Cannot determine caller's shared object");
1895 rlock_release();
1896 return NULL;
1897 }
1898 if (handle == NULL) { /* Just the caller's shared object. */
1899 def = symlook_obj(name, hash, obj, true);
1900 defobj = obj;
1901 } else if (handle == RTLD_NEXT || /* Objects after caller's */
1902 handle == RTLD_SELF) { /* ... caller included */
1903 if (handle == RTLD_NEXT)
1904 obj = obj->next;
1905 for (; obj != NULL; obj = obj->next) {
1906 if ((def = symlook_obj(name, hash, obj, true)) != NULL) {
1907 defobj = obj;
1908 break;
1909 }
1910 }
1911 } else {
1912 assert(handle == RTLD_DEFAULT);
1913 def = symlook_default(name, hash, obj, &defobj, true);
1914 }
1915 } else {
fb0c631e
SS
1916 DoneList donelist;
1917
984263bc
MD
1918 if ((obj = dlcheck(handle)) == NULL) {
1919 rlock_release();
1920 return NULL;
1921 }
1922
fb0c631e 1923 donelist_init(&donelist);
984263bc 1924 if (obj->mainprog) {
984263bc 1925 /* Search main program and all libraries loaded by it. */
984263bc
MD
1926 def = symlook_list(name, hash, &list_main, &defobj, true,
1927 &donelist);
1928 } else {
cebaf0af
SS
1929 Needed_Entry fake;
1930
1931 /* Search the given object and its needed objects. */
1932 fake.next = NULL;
1933 fake.obj = (Obj_Entry *)obj;
1934 fake.name = 0;
1935 def = symlook_needed(name, hash, &fake, &defobj, true,
fb0c631e 1936 &donelist);
984263bc
MD
1937 }
1938 }
1939
1940 if (def != NULL) {
1941 rlock_release();
1942 return defobj->relocbase + def->st_value;
1943 }
1944
1945 _rtld_error("Undefined symbol \"%s\"", name);
1946 rlock_release();
1947 return NULL;
1948}
1949
1950int
1951dladdr(const void *addr, Dl_info *info)
1952{
1953 const Obj_Entry *obj;
1954 const Elf_Sym *def;
1955 void *symbol_addr;
1956 unsigned long symoffset;
1957
1958 rlock_acquire();
1959 obj = obj_from_addr(addr);
1960 if (obj == NULL) {
1961 _rtld_error("No shared object contains address");
1962 rlock_release();
1963 return 0;
1964 }
1965 info->dli_fname = obj->path;
1966 info->dli_fbase = obj->mapbase;
1967 info->dli_saddr = (void *)0;
1968 info->dli_sname = NULL;
1969
1970 /*
1971 * Walk the symbol list looking for the symbol whose address is
1972 * closest to the address sent in.
1973 */
1974 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
1975 def = obj->symtab + symoffset;
1976
1977 /*
1978 * For skip the symbol if st_shndx is either SHN_UNDEF or
1979 * SHN_COMMON.
1980 */
1981 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
1982 continue;
1983
1984 /*
1985 * If the symbol is greater than the specified address, or if it
1986 * is further away from addr than the current nearest symbol,
1987 * then reject it.
1988 */
1989 symbol_addr = obj->relocbase + def->st_value;
1990 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
1991 continue;
1992
1993 /* Update our idea of the nearest symbol. */
1994 info->dli_sname = obj->strtab + def->st_name;
1995 info->dli_saddr = symbol_addr;
1996
1997 /* Exact match? */
1998 if (info->dli_saddr == addr)
1999 break;
2000 }
2001 rlock_release();
2002 return 1;
2003}
2004
2005int
2006dlinfo(void *handle, int request, void *p)
2007{
2008 const Obj_Entry *obj;
2009 int error;
2010
2011 rlock_acquire();
2012
2013 if (handle == NULL || handle == RTLD_SELF) {
2014 void *retaddr;
2015
2016 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2017 if ((obj = obj_from_addr(retaddr)) == NULL)
2018 _rtld_error("Cannot determine caller's shared object");
2019 } else
2020 obj = dlcheck(handle);
2021
2022 if (obj == NULL) {
2023 rlock_release();
2024 return (-1);
2025 }
2026
2027 error = 0;
2028 switch (request) {
2029 case RTLD_DI_LINKMAP:
2030 *((struct link_map const **)p) = &obj->linkmap;
2031 break;
2032 case RTLD_DI_ORIGIN:
2033 error = rtld_dirname(obj->path, p);
2034 break;
2035
2036 case RTLD_DI_SERINFOSIZE:
2037 case RTLD_DI_SERINFO:
2038 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2039 break;
2040
2041 default:
2042 _rtld_error("Invalid request %d passed to dlinfo()", request);
2043 error = -1;
2044 }
2045
2046 rlock_release();
2047
2048 return (error);
2049}
2050
2051struct fill_search_info_args {
2052 int request;
2053 unsigned int flags;
2054 Dl_serinfo *serinfo;
2055 Dl_serpath *serpath;
2056 char *strspace;
2057};
2058
2059static void *
2060fill_search_info(const char *dir, size_t dirlen, void *param)
2061{
2062 struct fill_search_info_args *arg;
2063
2064 arg = param;
2065
2066 if (arg->request == RTLD_DI_SERINFOSIZE) {
2067 arg->serinfo->dls_cnt ++;
2068 arg->serinfo->dls_size += dirlen + 1;
2069 } else {
2070 struct dl_serpath *s_entry;
2071
2072 s_entry = arg->serpath;
2073 s_entry->dls_name = arg->strspace;
2074 s_entry->dls_flags = arg->flags;
2075
2076 strncpy(arg->strspace, dir, dirlen);
2077 arg->strspace[dirlen] = '\0';
2078
2079 arg->strspace += dirlen + 1;
2080 arg->serpath++;
2081 }
2082
2083 return (NULL);
2084}
2085
2086static int
2087do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2088{
2089 struct dl_serinfo _info;
2090 struct fill_search_info_args args;
2091
2092 args.request = RTLD_DI_SERINFOSIZE;
2093 args.serinfo = &_info;
2094
2095 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2096 _info.dls_cnt = 0;
2097
2098 path_enumerate(ld_library_path, fill_search_info, &args);
2099 path_enumerate(obj->rpath, fill_search_info, &args);
2100 path_enumerate(gethints(), fill_search_info, &args);
2101 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2102
2103
2104 if (request == RTLD_DI_SERINFOSIZE) {
2105 info->dls_size = _info.dls_size;
2106 info->dls_cnt = _info.dls_cnt;
2107 return (0);
2108 }
2109
2110 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2111 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2112 return (-1);
2113 }
2114
2115 args.request = RTLD_DI_SERINFO;
2116 args.serinfo = info;
2117 args.serpath = &info->dls_serpath[0];
2118 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2119
2120 args.flags = LA_SER_LIBPATH;
2121 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2122 return (-1);
2123
2124 args.flags = LA_SER_RUNPATH;
2125 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2126 return (-1);
2127
2128 args.flags = LA_SER_CONFIG;
2129 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2130 return (-1);
2131
2132 args.flags = LA_SER_DEFAULT;
2133 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2134 return (-1);
2135 return (0);
2136}
2137
2138static int
2139rtld_dirname(const char *path, char *bname)
2140{
2141 const char *endp;
2142
2143 /* Empty or NULL string gets treated as "." */
2144 if (path == NULL || *path == '\0') {
2145 bname[0] = '.';
2146 bname[1] = '\0';
2147 return (0);
2148 }
2149
2150 /* Strip trailing slashes */
2151 endp = path + strlen(path) - 1;
2152 while (endp > path && *endp == '/')
2153 endp--;
2154
2155 /* Find the start of the dir */
2156 while (endp > path && *endp != '/')
2157 endp--;
2158
2159 /* Either the dir is "/" or there are no slashes */
2160 if (endp == path) {
2161 bname[0] = *endp == '/' ? '/' : '.';
2162 bname[1] = '\0';
2163 return (0);
2164 } else {
2165 do {
2166 endp--;
2167 } while (endp > path && *endp == '/');
2168 }
2169
2170 if (endp - path + 2 > PATH_MAX)
2171 {
2172 _rtld_error("Filename is too long: %s", path);
2173 return(-1);
2174 }
2175
2176 strncpy(bname, path, endp - path + 1);
2177 bname[endp - path + 1] = '\0';
2178 return (0);
2179}
2180
2181static void
2182linkmap_add(Obj_Entry *obj)
2183{
2184 struct link_map *l = &obj->linkmap;
2185 struct link_map *prev;
2186
2187 obj->linkmap.l_name = obj->path;
2188 obj->linkmap.l_addr = obj->mapbase;
2189 obj->linkmap.l_ld = obj->dynamic;
2190#ifdef __mips__
2191 /* GDB needs load offset on MIPS to use the symbols */
2192 obj->linkmap.l_offs = obj->relocbase;
2193#endif
2194
2195 if (r_debug.r_map == NULL) {
2196 r_debug.r_map = l;
2197 return;
2198 }
2199
2200 /*
2201 * Scan to the end of the list, but not past the entry for the
2202 * dynamic linker, which we want to keep at the very end.
2203 */
2204 for (prev = r_debug.r_map;
2205 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2206 prev = prev->l_next)
2207 ;
2208
2209 /* Link in the new entry. */
2210 l->l_prev = prev;
2211 l->l_next = prev->l_next;
2212 if (l->l_next != NULL)
2213 l->l_next->l_prev = l;
2214 prev->l_next = l;
2215}
2216
2217static void
2218linkmap_delete(Obj_Entry *obj)
2219{
2220 struct link_map *l = &obj->linkmap;
2221
2222 if (l->l_prev == NULL) {
2223 if ((r_debug.r_map = l->l_next) != NULL)
2224 l->l_next->l_prev = NULL;
2225 return;
2226 }
2227
2228 if ((l->l_prev->l_next = l->l_next) != NULL)
2229 l->l_next->l_prev = l->l_prev;
2230}
2231
2232/*
2233 * Function for the debugger to set a breakpoint on to gain control.
2234 *
2235 * The two parameters allow the debugger to easily find and determine
2236 * what the runtime loader is doing and to whom it is doing it.
2237 *
2238 * When the loadhook trap is hit (r_debug_state, set at program
2239 * initialization), the arguments can be found on the stack:
2240 *
2241 * +8 struct link_map *m
2242 * +4 struct r_debug *rd
2243 * +0 RetAddr
2244 */
2245void
2246r_debug_state(struct r_debug* rd, struct link_map *m)
2247{
2248}
2249
2250/*
2251 * Get address of the pointer variable in the main program.
2252 */
2253static const void **
2254get_program_var_addr(const char *name)
2255{
2256 const Obj_Entry *obj;
2257 unsigned long hash;
2258
2259 hash = elf_hash(name);
2260 for (obj = obj_main; obj != NULL; obj = obj->next) {
2261 const Elf_Sym *def;
2262
2263 if ((def = symlook_obj(name, hash, obj, false)) != NULL) {
2264 const void **addr;
2265
2266 addr = (const void **)(obj->relocbase + def->st_value);
2267 return addr;
2268 }
2269 }
2270 return NULL;
2271}
2272
2273/*
2274 * Set a pointer variable in the main program to the given value. This
2275 * is used to set key variables such as "environ" before any of the
2276 * init functions are called.
2277 */
2278static void
2279set_program_var(const char *name, const void *value)
2280{
2281 const void **addr;
2282
2283 if ((addr = get_program_var_addr(name)) != NULL) {
2284 dbg("\"%s\": *%p <-- %p", name, addr, value);
2285 *addr = value;
2286 }
2287}
2288
8ca15ec8
MD
2289/*
2290 * This is a special version of getenv which is far more efficient
2291 * at finding LD_ environment vars.
2292 */
2293static
2294const char *
2295_getenv_ld(const char *id)
2296{
2297 const char *envp;
2298 int i, j;
2299 int idlen = strlen(id);
2300
2301 if (ld_index == LD_ARY_CACHE)
2302 return(getenv(id));
2303 if (ld_index == 0) {
2304 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) {
2305 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_')
2306 ld_ary[j++] = envp;
2307 }
2308 if (j == 0)
2309 ld_ary[j++] = "";
2310 ld_index = j;
2311 }
2312 for (i = ld_index - 1; i >= 0; --i) {
2313 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=')
2314 return(ld_ary[i] + idlen + 1);
2315 }
2316 return(NULL);
2317}
2318
984263bc
MD
2319/*
2320 * Given a symbol name in a referencing object, find the corresponding
2321 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2322 * no definition was found. Returns a pointer to the Obj_Entry of the
2323 * defining object via the reference parameter DEFOBJ_OUT.
2324 */
2325static const Elf_Sym *
2326symlook_default(const char *name, unsigned long hash,
2327 const Obj_Entry *refobj, const Obj_Entry **defobj_out, bool in_plt)
2328{
2329 DoneList donelist;
2330 const Elf_Sym *def;
2331 const Elf_Sym *symp;
2332 const Obj_Entry *obj;
2333 const Obj_Entry *defobj;
2334 const Objlist_Entry *elm;
2335 def = NULL;
2336 defobj = NULL;
2337 donelist_init(&donelist);
2338
2339 /* Look first in the referencing object if linked symbolically. */
2340 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
2341 symp = symlook_obj(name, hash, refobj, in_plt);
2342 if (symp != NULL) {
2343 def = symp;
2344 defobj = refobj;
2345 }
2346 }
2347
2348 /* Search all objects loaded at program start up. */
2349 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2350 symp = symlook_list(name, hash, &list_main, &obj, in_plt, &donelist);
2351 if (symp != NULL &&
2352 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2353 def = symp;
2354 defobj = obj;
2355 }
2356 }
2357
2358 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2359 STAILQ_FOREACH(elm, &list_global, link) {
2360 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2361 break;
2362 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2363 &donelist);
2364 if (symp != NULL &&
2365 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2366 def = symp;
2367 defobj = obj;
2368 }
2369 }
2370
2371 /* Search all dlopened DAGs containing the referencing object. */
2372 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2373 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2374 break;
2375 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2376 &donelist);
2377 if (symp != NULL &&
2378 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2379 def = symp;
2380 defobj = obj;
2381 }
2382 }
2383
2384 /*
2385 * Search the dynamic linker itself, and possibly resolve the
2386 * symbol from there. This is how the application links to
2387 * dynamic linker services such as dlopen. Only the values listed
2388 * in the "exports" array can be resolved from the dynamic linker.
2389 */
2390 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2391 symp = symlook_obj(name, hash, &obj_rtld, in_plt);
2392 if (symp != NULL && is_exported(symp)) {
2393 def = symp;
2394 defobj = &obj_rtld;
2395 }
2396 }
2397
2398 if (def != NULL)
2399 *defobj_out = defobj;
2400 return def;
2401}
2402
2403static const Elf_Sym *
fb0c631e 2404symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
984263bc
MD
2405 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2406{
2407 const Elf_Sym *symp;
2408 const Elf_Sym *def;
2409 const Obj_Entry *defobj;
2410 const Objlist_Entry *elm;
2411
2412 def = NULL;
2413 defobj = NULL;
2414 STAILQ_FOREACH(elm, objlist, link) {
2415 if (donelist_check(dlp, elm->obj))
2416 continue;
2417 if ((symp = symlook_obj(name, hash, elm->obj, in_plt)) != NULL) {
2418 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2419 def = symp;
2420 defobj = elm->obj;
2421 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2422 break;
2423 }
2424 }
2425 }
2426 if (def != NULL)
2427 *defobj_out = defobj;
2428 return def;
2429}
2430
cebaf0af
SS
2431/*
2432 * Search the symbol table of a shared object and all objects needed
2433 * by it for a symbol of the given name. Search order is
2434 * breadth-first. Returns a pointer to the symbol, or NULL if no
2435 * definition was found.
2436 */
2437static const Elf_Sym *
2438symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
2439 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2440{
2441 const Elf_Sym *def, *def_w;
2442 const Needed_Entry *n;
2443 const Obj_Entry *obj, *defobj, *defobj1;
2444
2445 def = def_w = NULL;
2446 defobj = NULL;
2447 for (n = needed; n != NULL; n = n->next) {
2448 if ((obj = n->obj) == NULL ||
2449 donelist_check(dlp, obj) ||
2450 (def = symlook_obj(name, hash, obj, in_plt)) == NULL)
2451 continue;
2452 defobj = obj;
2453 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2454 *defobj_out = defobj;
2455 return (def);
2456 }
2457 }
2458 /*
2459 * There we come when either symbol definition is not found in
2460 * directly needed objects, or found symbol is weak.
2461 */
2462 for (n = needed; n != NULL; n = n->next) {
2463 if ((obj = n->obj) == NULL)
2464 continue;
2465 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
2466 in_plt, dlp);
2467 if (def_w == NULL)
2468 continue;
2469 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
2470 def = def_w;
2471 defobj = defobj1;
2472 }
2473 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
2474 break;
2475 }
2476 if (def != NULL)
2477 *defobj_out = defobj;
2478 return def;
2479}
2480
984263bc
MD
2481/*
2482 * Search the symbol table of a single shared object for a symbol of
2483 * the given name. Returns a pointer to the symbol, or NULL if no
2484 * definition was found.
2485 *
2486 * The symbol's hash value is passed in for efficiency reasons; that
2487 * eliminates many recomputations of the hash value.
2488 */
2489const Elf_Sym *
2490symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
2491 bool in_plt)
2492{
2493 if (obj->buckets != NULL) {
2494 unsigned long symnum = obj->buckets[hash % obj->nbuckets];
2495
2496 while (symnum != STN_UNDEF) {
2497 const Elf_Sym *symp;
2498 const char *strp;
2499
2500 if (symnum >= obj->nchains)
2501 return NULL; /* Bad object */
2502 symp = obj->symtab + symnum;
2503 strp = obj->strtab + symp->st_name;
2504
2505 if (name[0] == strp[0] && strcmp(name, strp) == 0)
2506 return symp->st_shndx != SHN_UNDEF ||
2507 (!in_plt && symp->st_value != 0 &&
2508 ELF_ST_TYPE(symp->st_info) == STT_FUNC) ? symp : NULL;
2509
2510 symnum = obj->chains[symnum];
2511 }
2512 }
2513 return NULL;
2514}
2515
2516static void
2517trace_loaded_objects(Obj_Entry *obj)
2518{
8ca15ec8 2519 const char *fmt1, *fmt2, *fmt, *main_local;
984263bc
MD
2520 int c;
2521
8ca15ec8 2522 if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
984263bc
MD
2523 main_local = "";
2524
8ca15ec8 2525 if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL)
984263bc
MD
2526 fmt1 = "\t%o => %p (%x)\n";
2527
8ca15ec8 2528 if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
984263bc
MD
2529 fmt2 = "\t%o (%x)\n";
2530
2531 for (; obj; obj = obj->next) {
2532 Needed_Entry *needed;
2533 char *name, *path;
2534 bool is_lib;
2535
2536 for (needed = obj->needed; needed; needed = needed->next) {
2537 if (needed->obj != NULL) {
2538 if (needed->obj->traced)
2539 continue;
2540 needed->obj->traced = true;
2541 path = needed->obj->path;
2542 } else
2543 path = "not found";
2544
2545 name = (char *)obj->strtab + needed->name;
2546 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
2547
2548 fmt = is_lib ? fmt1 : fmt2;
2549 while ((c = *fmt++) != '\0') {
2550 switch (c) {
2551 default:
2552 putchar(c);
2553 continue;
2554 case '\\':
2555 switch (c = *fmt) {
2556 case '\0':
2557 continue;
2558 case 'n':
2559 putchar('\n');
2560 break;
2561 case 't':
2562 putchar('\t');
2563 break;
2564 }
2565 break;
2566 case '%':
2567 switch (c = *fmt) {
2568 case '\0':
2569 continue;
2570 case '%':
2571 default:
2572 putchar(c);
2573 break;
2574 case 'A':
2575 printf("%s", main_local);
2576 break;
2577 case 'a':
2578 printf("%s", obj_main->path);
2579 break;
2580 case 'o':
2581 printf("%s", name);
2582 break;
2583#if 0
2584 case 'm':
2585 printf("%d", sodp->sod_major);
2586 break;
2587 case 'n':
2588 printf("%d", sodp->sod_minor);
2589 break;
2590#endif
2591 case 'p':
2592 printf("%s", path);
2593 break;
2594 case 'x':
2595 printf("%p", needed->obj ? needed->obj->mapbase : 0);
2596 break;
2597 }
2598 break;
2599 }
2600 ++fmt;
2601 }
2602 }
2603 }
2604}
2605
2606/*
2607 * Unload a dlopened object and its dependencies from memory and from
2608 * our data structures. It is assumed that the DAG rooted in the
2609 * object has already been unreferenced, and that the object has a
2610 * reference count of 0.
2611 */
2612static void
2613unload_object(Obj_Entry *root)
2614{
2615 Obj_Entry *obj;
2616 Obj_Entry **linkp;
2617
2618 assert(root->refcount == 0);
2619
2620 /*
2621 * Pass over the DAG removing unreferenced objects from
2622 * appropriate lists.
2623 */
2624 unlink_object(root);
2625
2626 /* Unmap all objects that are no longer referenced. */
2627 linkp = &obj_list->next;
2628 while ((obj = *linkp) != NULL) {
2629 if (obj->refcount == 0) {
2630 dbg("unloading \"%s\"", obj->path);
2631 munmap(obj->mapbase, obj->mapsize);
2632 linkmap_delete(obj);
2633 *linkp = obj->next;
2634 obj_count--;
2635 obj_free(obj);
2636 } else
2637 linkp = &obj->next;
2638 }
2639 obj_tail = linkp;
2640}
2641
2642static void
2643unlink_object(Obj_Entry *root)
2644{
2645 const Needed_Entry *needed;
2646 Objlist_Entry *elm;
2647
2648 if (root->refcount == 0) {
2649 /* Remove the object from the RTLD_GLOBAL list. */
2650 objlist_remove(&list_global, root);
2651
2652 /* Remove the object from all objects' DAG lists. */
2653 STAILQ_FOREACH(elm, &root->dagmembers , link)
2654 objlist_remove(&elm->obj->dldags, root);
2655 }
2656
2657 for (needed = root->needed; needed != NULL; needed = needed->next)
2658 if (needed->obj != NULL)
2659 unlink_object(needed->obj);
2660}
2661
2662static void
2663unref_dag(Obj_Entry *root)
2664{
2665 const Needed_Entry *needed;
2666
2667 if (root->refcount == 0)
2668 return;
2669 root->refcount--;
2670 if (root->refcount == 0)
2671 for (needed = root->needed; needed != NULL; needed = needed->next)
2672 if (needed->obj != NULL)
2673 unref_dag(needed->obj);
2674}
55b88cae
DX
2675
2676/*
2677 * Common code for MD __tls_get_addr().
2678 */
2679void *
bc633d63 2680tls_get_addr_common(void **dtvp, int index, size_t offset)
55b88cae
DX
2681{
2682 Elf_Addr* dtv = *dtvp;
2683
2684 /* Check dtv generation in case new modules have arrived */
2685 if (dtv[0] != tls_dtv_generation) {
2686 Elf_Addr* newdtv;
2687 int to_copy;
2688
2689 wlock_acquire();
2690
2691 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
2692 to_copy = dtv[1];
2693 if (to_copy > tls_max_index)
2694 to_copy = tls_max_index;
2695 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
2696 newdtv[0] = tls_dtv_generation;
2697 newdtv[1] = tls_max_index;
2698 free(dtv);
bc633d63 2699 *dtvp = newdtv;
55b88cae
DX
2700
2701 wlock_release();
55b88cae
DX
2702 }
2703
2704 /* Dynamically allocate module TLS if necessary */
2705 if (!dtv[index + 1]) {
2706 /* XXX
2707 * here we should avoid to be re-entered by signal handler
2708 * code, I assume wlock_acquire will masked all signals,
2709 * otherwise there is race and dead lock thread itself.
2710 */
2711 wlock_acquire();
2712 if (!dtv[index + 1])
2713 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
2714 wlock_release();
2715 }
2716
2717 return (void*) (dtv[index + 1] + offset);
2718}
2719
9e2ee207 2720#if defined(RTLD_STATIC_TLS_VARIANT_II)
55b88cae
DX
2721
2722/*
bc633d63
MD
2723 * Allocate the static TLS area. Return a pointer to the TCB. The
2724 * static area is based on negative offsets relative to the tcb.
a1eee96a
MD
2725 *
2726 * The TCB contains an errno pointer for the system call layer, but because
2727 * we are the RTLD we really have no idea how the caller was compiled so
2728 * the information has to be passed in. errno can either be:
2729 *
2730 * type 0 errno is a simple non-TLS global pointer.
2731 * (special case for e.g. libc_rtld)
2732 * type 1 errno accessed by GOT entry (dynamically linked programs)
2733 * type 2 errno accessed by %gs:OFFSET (statically linked programs)
55b88cae 2734 */
bc633d63 2735struct tls_tcb *
a1eee96a 2736allocate_tls(Obj_Entry *objs)
55b88cae
DX
2737{
2738 Obj_Entry *obj;
bc633d63 2739 size_t data_size;
bc633d63
MD
2740 size_t dtv_size;
2741 struct tls_tcb *tcb;
a1eee96a 2742 Elf_Addr *dtv;
bc633d63 2743 Elf_Addr addr;
55b88cae 2744
bc633d63
MD
2745 /*
2746 * Allocate the new TCB. static TLS storage is placed just before the
2747 * TCB to support the %gs:OFFSET (negative offset) model.
2748 */
bc633d63
MD
2749 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
2750 ~RTLD_STATIC_TLS_ALIGN_MASK;
f20fd431 2751 tcb = malloc(data_size + sizeof(*tcb));
bc633d63 2752 tcb = (void *)((char *)tcb + data_size); /* actual tcb location */
55b88cae 2753
bc633d63
MD
2754 dtv_size = (tls_max_index + 2) * sizeof(Elf_Addr);
2755 dtv = malloc(dtv_size);
2756 bzero(dtv, dtv_size);
55b88cae 2757
9e2ee207
JS
2758#ifdef RTLD_TCB_HAS_SELF_POINTER
2759 tcb->tcb_self = tcb;
2760#endif
2761 tcb->tcb_dtv = dtv;
2762 tcb->tcb_pthread = NULL;
55b88cae
DX
2763
2764 dtv[0] = tls_dtv_generation;
2765 dtv[1] = tls_max_index;
2766
a1eee96a
MD
2767 for (obj = objs; obj; obj = obj->next) {
2768 if (obj->tlsoffset) {
2769 addr = (Elf_Addr)tcb - obj->tlsoffset;
2770 memset((void *)(addr + obj->tlsinitsize),
2771 0, obj->tlssize - obj->tlsinitsize);
2772 if (obj->tlsinit)
2773 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
2774 dtv[obj->tlsindex + 1] = addr;
55b88cae
DX
2775 }
2776 }
bc633d63 2777 return(tcb);
55b88cae
DX
2778}
2779
2780void
f20fd431 2781free_tls(struct tls_tcb *tcb)
bc633d63
MD
2782{
2783 Elf_Addr *dtv;
2784 int dtv_size, i;
2785 Elf_Addr tls_start, tls_end;
2786 size_t data_size;
2787
2788 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
2789 ~RTLD_STATIC_TLS_ALIGN_MASK;
9e2ee207 2790 dtv = tcb->tcb_dtv;
bc633d63
MD
2791 dtv_size = dtv[1];
2792 tls_end = (Elf_Addr)tcb;
2793 tls_start = (Elf_Addr)tcb - data_size;
2794 for (i = 0; i < dtv_size; i++) {
eecd52b2 2795 if (dtv[i+2] != 0 && (dtv[i+2] < tls_start || dtv[i+2] > tls_end)) {
bc633d63 2796 free((void *)dtv[i+2]);
55b88cae
DX
2797 }
2798 }
bc633d63 2799 free((void *)tls_start);
55b88cae
DX
2800}
2801
9e2ee207
JS
2802#else
2803#error "Unsupported TLS layout"
55b88cae
DX
2804#endif
2805
2806/*
2807 * Allocate TLS block for module with given index.
2808 */
2809void *
2810allocate_module_tls(int index)
2811{
2812 Obj_Entry* obj;
2813 char* p;
2814
2815 for (obj = obj_list; obj; obj = obj->next) {
2816 if (obj->tlsindex == index)
2817 break;
2818 }
2819 if (!obj) {
2820 _rtld_error("Can't find module with TLS index %d", index);
2821 die();
2822 }
2823
2824 p = malloc(obj->tlssize);
2825 memcpy(p, obj->tlsinit, obj->tlsinitsize);
2826 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
2827
2828 return p;
2829}
2830
2831bool
2832allocate_tls_offset(Obj_Entry *obj)
2833{
2834 size_t off;
2835
2836 if (obj->tls_done)
2837 return true;
2838
2839 if (obj->tlssize == 0) {
2840 obj->tls_done = true;
2841 return true;
2842 }
2843
2844 if (obj->tlsindex == 1)
2845 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
2846 else
2847 off = calculate_tls_offset(tls_last_offset, tls_last_size,
2848 obj->tlssize, obj->tlsalign);
2849
2850 /*
2851 * If we have already fixed the size of the static TLS block, we
2852 * must stay within that size. When allocating the static TLS, we
2853 * leave a small amount of space spare to be used for dynamically
2854 * loading modules which use static TLS.
2855 */
2856 if (tls_static_space) {
2857 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
2858 return false;
2859 }
2860
2861 tls_last_offset = obj->tlsoffset = off;
2862 tls_last_size = obj->tlssize;
2863 obj->tls_done = true;
2864
2865 return true;
2866}
2867
2868void
2869free_tls_offset(Obj_Entry *obj)
2870{
9e2ee207 2871#ifdef RTLD_STATIC_TLS_VARIANT_II
55b88cae
DX
2872 /*
2873 * If we were the last thing to allocate out of the static TLS
2874 * block, we give our space back to the 'allocator'. This is a
2875 * simplistic workaround to allow libGL.so.1 to be loaded and
2876 * unloaded multiple times. We only handle the Variant II
2877 * mechanism for now - this really needs a proper allocator.
2878 */
2879 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
2880 == calculate_tls_end(tls_last_offset, tls_last_size)) {
2881 tls_last_offset -= obj->tlssize;
2882 tls_last_size = 0;
2883 }
2884#endif
2885}
2886
bc633d63 2887struct tls_tcb *
a1eee96a 2888_rtld_allocate_tls(void)
55b88cae 2889{
bc633d63 2890 struct tls_tcb *new_tcb;
55b88cae
DX
2891
2892 wlock_acquire();
a1eee96a 2893 new_tcb = allocate_tls(obj_list);
55b88cae
DX
2894 wlock_release();
2895
bc633d63 2896 return (new_tcb);
55b88cae
DX
2897}
2898
2899void
f20fd431 2900_rtld_free_tls(struct tls_tcb *tcb)
55b88cae
DX
2901{
2902 wlock_acquire();
f20fd431 2903 free_tls(tcb);
55b88cae
DX
2904 wlock_release();
2905}
bc633d63 2906