fill_kinfo_proc() may be asked to load information on a zombied process,
[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 $
eecd52b2 27 * $DragonFly: src/libexec/rtld-elf/rtld.c,v 1.28 2007/11/25 18:10:06 swildner 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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150static Obj_Entry *obj_list; /* Head of linked list of shared objects */
151static Obj_Entry **obj_tail; /* Link field of last object in list */
8ca15ec8 152static Obj_Entry **preload_tail;
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153static Obj_Entry *obj_main; /* The main program shared object */
154static Obj_Entry obj_rtld; /* The dynamic linker shared object */
155static unsigned int obj_count; /* Number of objects in obj_list */
33a8b578 156static int ld_resident; /* Non-zero if resident */
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157static const char *ld_ary[LD_ARY_CACHE];
158static int ld_index;
a1eee96a 159static Objlist initlist;
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160
161static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
162 STAILQ_HEAD_INITIALIZER(list_global);
163static Objlist list_main = /* Objects loaded at program startup */
164 STAILQ_HEAD_INITIALIZER(list_main);
165static Objlist list_fini = /* Objects needing fini() calls */
166 STAILQ_HEAD_INITIALIZER(list_fini);
167
168static LockInfo lockinfo;
169
170static Elf_Sym sym_zero; /* For resolving undefined weak refs. */
171
172#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
173
174extern Elf_Dyn _DYNAMIC;
175#pragma weak _DYNAMIC
176
177/*
178 * These are the functions the dynamic linker exports to application
179 * programs. They are the only symbols the dynamic linker is willing
180 * to export from itself.
181 */
182static func_ptr_type exports[] = {
183 (func_ptr_type) &_rtld_error,
184 (func_ptr_type) &dlclose,
185 (func_ptr_type) &dlerror,
186 (func_ptr_type) &dlopen,
187 (func_ptr_type) &dlsym,
188 (func_ptr_type) &dladdr,
984263bc 189 (func_ptr_type) &dlinfo,
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190#ifdef __i386__
191 (func_ptr_type) &___tls_get_addr,
192#endif
193 (func_ptr_type) &__tls_get_addr,
a1eee96a 194 (func_ptr_type) &__tls_get_addr_tcb,
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195 (func_ptr_type) &_rtld_allocate_tls,
196 (func_ptr_type) &_rtld_free_tls,
a1eee96a 197 (func_ptr_type) &_rtld_call_init,
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198 NULL
199};
200
201/*
202 * Global declarations normally provided by crt1. The dynamic linker is
203 * not built with crt1, so we have to provide them ourselves.
204 */
205char *__progname;
206char **environ;
207
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208/*
209 * Globals to control TLS allocation.
210 */
211size_t tls_last_offset; /* Static TLS offset of last module */
212size_t tls_last_size; /* Static TLS size of last module */
213size_t tls_static_space; /* Static TLS space allocated */
214int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
215int tls_max_index = 1; /* Largest module index allocated */
216
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217/*
218 * Fill in a DoneList with an allocation large enough to hold all of
219 * the currently-loaded objects. Keep this as a macro since it calls
220 * alloca and we want that to occur within the scope of the caller.
221 */
222#define donelist_init(dlp) \
223 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
224 assert((dlp)->objs != NULL), \
225 (dlp)->num_alloc = obj_count, \
226 (dlp)->num_used = 0)
227
228static __inline void
229rlock_acquire(void)
230{
231 lockinfo.rlock_acquire(lockinfo.thelock);
232 atomic_incr_int(&lockinfo.rcount);
233 lock_check();
234}
235
236static __inline void
237wlock_acquire(void)
238{
239 lockinfo.wlock_acquire(lockinfo.thelock);
240 atomic_incr_int(&lockinfo.wcount);
241 lock_check();
242}
243
244static __inline void
245rlock_release(void)
246{
247 atomic_decr_int(&lockinfo.rcount);
248 lockinfo.rlock_release(lockinfo.thelock);
249}
250
251static __inline void
252wlock_release(void)
253{
254 atomic_decr_int(&lockinfo.wcount);
255 lockinfo.wlock_release(lockinfo.thelock);
256}
257
258/*
259 * Main entry point for dynamic linking. The first argument is the
260 * stack pointer. The stack is expected to be laid out as described
261 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
262 * Specifically, the stack pointer points to a word containing
263 * ARGC. Following that in the stack is a null-terminated sequence
264 * of pointers to argument strings. Then comes a null-terminated
265 * sequence of pointers to environment strings. Finally, there is a
266 * sequence of "auxiliary vector" entries.
267 *
268 * The second argument points to a place to store the dynamic linker's
269 * exit procedure pointer and the third to a place to store the main
270 * program's object.
271 *
272 * The return value is the main program's entry point.
273 */
a1eee96a 274
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275func_ptr_type
276_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
277{
278 Elf_Auxinfo *aux_info[AT_COUNT];
279 int i;
280 int argc;
281 char **argv;
282 char **env;
283 Elf_Auxinfo *aux;
284 Elf_Auxinfo *auxp;
285 const char *argv0;
55b88cae 286 Objlist_Entry *entry;
984263bc 287 Obj_Entry *obj;
984263bc 288
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289 ld_index = 0; /* don't use old env cache in case we are resident */
290
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291 /*
292 * On entry, the dynamic linker itself has not been relocated yet.
293 * Be very careful not to reference any global data until after
294 * init_rtld has returned. It is OK to reference file-scope statics
295 * and string constants, and to call static and global functions.
296 */
297
298 /* Find the auxiliary vector on the stack. */
299 argc = *sp++;
300 argv = (char **) sp;
301 sp += argc + 1; /* Skip over arguments and NULL terminator */
302 env = (char **) sp;
984263bc 303
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304 /*
305 * If we aren't already resident we have to dig out some more info.
306 * Note that auxinfo does not exist when we are resident.
307 */
308 if (ld_resident == 0) {
309 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
310 ;
311 aux = (Elf_Auxinfo *) sp;
312
313 /* Digest the auxiliary vector. */
314 for (i = 0; i < AT_COUNT; i++)
315 aux_info[i] = NULL;
316 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
317 if (auxp->a_type < AT_COUNT)
318 aux_info[auxp->a_type] = auxp;
319 }
320
321 /* Initialize and relocate ourselves. */
322 assert(aux_info[AT_BASE] != NULL);
323 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
324 }
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325
326 __progname = obj_rtld.path;
327 argv0 = argv[0] != NULL ? argv[0] : "(null)";
328 environ = env;
329
8ca15ec8 330 trust = (geteuid() == getuid()) && (getegid() == getgid());
984263bc 331
8ca15ec8 332 ld_bind_now = _getenv_ld("LD_BIND_NOW");
984263bc 333 if (trust) {
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MD
334 ld_debug = _getenv_ld("LD_DEBUG");
335 ld_library_path = _getenv_ld("LD_LIBRARY_PATH");
336 ld_preload = (char *)_getenv_ld("LD_PRELOAD");
984263bc 337 }
8ca15ec8 338 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS");
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339
340 if (ld_debug != NULL && *ld_debug != '\0')
341 debug = 1;
342 dbg("%s is initialized, base address = %p", __progname,
343 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
344 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
345 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
346
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347 /*
348 * If we are resident we can skip work that we have already done.
349 * Note that the stack is reset and there is no Elf_Auxinfo
350 * when running from a resident image, and the static globals setup
351 * between here and resident_skip will have already been setup.
352 */
8ca15ec8 353 if (ld_resident)
33a8b578 354 goto resident_skip1;
33a8b578 355
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356 /*
357 * Load the main program, or process its program header if it is
358 * already loaded.
359 */
360 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
361 int fd = aux_info[AT_EXECFD]->a_un.a_val;
362 dbg("loading main program");
363 obj_main = map_object(fd, argv0, NULL);
364 close(fd);
365 if (obj_main == NULL)
366 die();
367 } else { /* Main program already loaded. */
368 const Elf_Phdr *phdr;
369 int phnum;
370 caddr_t entry;
371
372 dbg("processing main program's program header");
373 assert(aux_info[AT_PHDR] != NULL);
374 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
375 assert(aux_info[AT_PHNUM] != NULL);
376 phnum = aux_info[AT_PHNUM]->a_un.a_val;
377 assert(aux_info[AT_PHENT] != NULL);
378 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
379 assert(aux_info[AT_ENTRY] != NULL);
380 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
381 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
382 die();
383 }
384
385 obj_main->path = xstrdup(argv0);
386 obj_main->mainprog = true;
387
388 /*
389 * Get the actual dynamic linker pathname from the executable if
390 * possible. (It should always be possible.) That ensures that
391 * gdb will find the right dynamic linker even if a non-standard
392 * one is being used.
393 */
394 if (obj_main->interp != NULL &&
395 strcmp(obj_main->interp, obj_rtld.path) != 0) {
396 free(obj_rtld.path);
397 obj_rtld.path = xstrdup(obj_main->interp);
b7b05c9f 398 __progname = obj_rtld.path;
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MD
399 }
400
c3098c28 401 digest_dynamic(obj_main, 0);
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402
403 linkmap_add(obj_main);
404 linkmap_add(&obj_rtld);
405
406 /* Link the main program into the list of objects. */
407 *obj_tail = obj_main;
408 obj_tail = &obj_main->next;
409 obj_count++;
410 obj_main->refcount++;
411 /* Make sure we don't call the main program's init and fini functions. */
412 obj_main->init = obj_main->fini = NULL;
413
414 /* Initialize a fake symbol for resolving undefined weak references. */
415 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
416 sym_zero.st_shndx = SHN_ABS;
417
418 dbg("loading LD_PRELOAD libraries");
419 if (load_preload_objects() == -1)
420 die();
421 preload_tail = obj_tail;
422
423 dbg("loading needed objects");
424 if (load_needed_objects(obj_main) == -1)
425 die();
426
427 /* Make a list of all objects loaded at startup. */
428 for (obj = obj_list; obj != NULL; obj = obj->next)
429 objlist_push_tail(&list_main, obj);
430
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431resident_skip1:
432
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433 if (ld_tracing) { /* We're done */
434 trace_loaded_objects(obj_main);
435 exit(0);
436 }
437
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MD
438 if (ld_resident) /* XXX clean this up! */
439 goto resident_skip2;
440
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441 if (getenv("LD_DUMP_REL_PRE") != NULL) {
442 dump_relocations(obj_main);
443 exit (0);
444 }
445
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446 /* setup TLS for main thread */
447 dbg("initializing initial thread local storage");
448 STAILQ_FOREACH(entry, &list_main, link) {
449 /*
450 * Allocate all the initial objects out of the static TLS
451 * block even if they didn't ask for it.
452 */
453 allocate_tls_offset(entry->obj);
454 }
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MD
455
456 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
457
458 /*
459 * Do not try to allocate the TLS here, let libc do it itself.
460 * (crt1 for the program will call _init_tls())
461 */
55b88cae 462
6192271e 463 if (relocate_objects(obj_main,
c3098c28 464 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
6192271e 465 die();
984263bc 466
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MD
467 dbg("doing copy relocations");
468 if (do_copy_relocations(obj_main) == -1)
469 die();
1c76efe5 470
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471resident_skip2:
472
8ca15ec8 473 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) {
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MD
474 if (exec_sys_unregister(-1) < 0) {
475 dbg("exec_sys_unregister failed %d\n", errno);
476 exit(errno);
477 }
478 dbg("exec_sys_unregister success\n");
479 exit(0);
480 }
984263bc 481
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482 if (getenv("LD_DUMP_REL_POST") != NULL) {
483 dump_relocations(obj_main);
484 exit (0);
485 }
486
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487 dbg("initializing key program variables");
488 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
489 set_program_var("environ", env);
490
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MD
491 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) {
492 extern void resident_start(void);
493 ld_resident = 1;
494 if (exec_sys_register(resident_start) < 0) {
495 dbg("exec_sys_register failed %d\n", errno);
496 exit(errno);
497 }
498 dbg("exec_sys_register success\n");
499 exit(0);
500 }
501
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502 dbg("initializing thread locks");
503 lockdflt_init(&lockinfo);
504 lockinfo.thelock = lockinfo.lock_create(lockinfo.context);
505
506 /* Make a list of init functions to call. */
507 objlist_init(&initlist);
508 initlist_add_objects(obj_list, preload_tail, &initlist);
509
510 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
511
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512 /*
513 * Do NOT call the initlist here, give libc a chance to set up
514 * the initial TLS segment. crt1 will then call _rtld_call_init().
515 */
8ca15ec8 516
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517 dbg("transferring control to program entry point = %p", obj_main->entry);
518
519 /* Return the exit procedure and the program entry point. */
520 *exit_proc = rtld_exit;
521 *objp = obj_main;
522 return (func_ptr_type) obj_main->entry;
523}
524
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525/*
526 * Call the initialization list for dynamically loaded libraries.
527 * (called from crt1.c).
528 */
529void
530_rtld_call_init(void)
531{
532 objlist_call_init(&initlist);
533 wlock_acquire();
534 objlist_clear(&initlist);
535 wlock_release();
536}
537
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538Elf_Addr
539_rtld_bind(Obj_Entry *obj, Elf_Word reloff)
540{
541 const Elf_Rel *rel;
542 const Elf_Sym *def;
543 const Obj_Entry *defobj;
544 Elf_Addr *where;
545 Elf_Addr target;
546
547 rlock_acquire();
548 if (obj->pltrel)
549 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
550 else
551 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
552
553 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
554 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
555 if (def == NULL)
556 die();
557
558 target = (Elf_Addr)(defobj->relocbase + def->st_value);
559
560 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
561 defobj->strtab + def->st_name, basename(obj->path),
562 (void *)target, basename(defobj->path));
563
564 reloc_jmpslot(where, target);
565 rlock_release();
566 return target;
567}
568
569/*
570 * Error reporting function. Use it like printf. If formats the message
571 * into a buffer, and sets things up so that the next call to dlerror()
572 * will return the message.
573 */
574void
575_rtld_error(const char *fmt, ...)
576{
577 static char buf[512];
578 va_list ap;
579
580 va_start(ap, fmt);
581 vsnprintf(buf, sizeof buf, fmt, ap);
582 error_message = buf;
583 va_end(ap);
584}
585
586/*
587 * Return a dynamically-allocated copy of the current error message, if any.
588 */
589static char *
590errmsg_save(void)
591{
592 return error_message == NULL ? NULL : xstrdup(error_message);
593}
594
595/*
596 * Restore the current error message from a copy which was previously saved
597 * by errmsg_save(). The copy is freed.
598 */
599static void
600errmsg_restore(char *saved_msg)
601{
602 if (saved_msg == NULL)
603 error_message = NULL;
604 else {
605 _rtld_error("%s", saved_msg);
606 free(saved_msg);
607 }
608}
609
1c76efe5 610const char *
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611basename(const char *name)
612{
613 const char *p = strrchr(name, '/');
614 return p != NULL ? p + 1 : name;
615}
616
617static void
618die(void)
619{
620 const char *msg = dlerror();
621
622 if (msg == NULL)
623 msg = "Fatal error";
624 errx(1, "%s", msg);
625}
626
627/*
628 * Process a shared object's DYNAMIC section, and save the important
629 * information in its Obj_Entry structure.
630 */
631static void
c3098c28 632digest_dynamic(Obj_Entry *obj, int early)
984263bc
MD
633{
634 const Elf_Dyn *dynp;
635 Needed_Entry **needed_tail = &obj->needed;
636 const Elf_Dyn *dyn_rpath = NULL;
637 int plttype = DT_REL;
638
639 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
640 switch (dynp->d_tag) {
641
642 case DT_REL:
643 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
644 break;
645
646 case DT_RELSZ:
647 obj->relsize = dynp->d_un.d_val;
648 break;
649
650 case DT_RELENT:
651 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
652 break;
653
654 case DT_JMPREL:
655 obj->pltrel = (const Elf_Rel *)
656 (obj->relocbase + dynp->d_un.d_ptr);
657 break;
658
659 case DT_PLTRELSZ:
660 obj->pltrelsize = dynp->d_un.d_val;
661 break;
662
663 case DT_RELA:
664 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
665 break;
666
667 case DT_RELASZ:
668 obj->relasize = dynp->d_un.d_val;
669 break;
670
671 case DT_RELAENT:
672 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
673 break;
674
675 case DT_PLTREL:
676 plttype = dynp->d_un.d_val;
677 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
678 break;
679
680 case DT_SYMTAB:
681 obj->symtab = (const Elf_Sym *)
682 (obj->relocbase + dynp->d_un.d_ptr);
683 break;
684
685 case DT_SYMENT:
686 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
687 break;
688
689 case DT_STRTAB:
690 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
691 break;
692
693 case DT_STRSZ:
694 obj->strsize = dynp->d_un.d_val;
695 break;
696
697 case DT_HASH:
698 {
699 const Elf_Addr *hashtab = (const Elf_Addr *)
700 (obj->relocbase + dynp->d_un.d_ptr);
701 obj->nbuckets = hashtab[0];
702 obj->nchains = hashtab[1];
703 obj->buckets = hashtab + 2;
704 obj->chains = obj->buckets + obj->nbuckets;
705 }
706 break;
707
708 case DT_NEEDED:
709 if (!obj->rtld) {
710 Needed_Entry *nep = NEW(Needed_Entry);
711 nep->name = dynp->d_un.d_val;
712 nep->obj = NULL;
713 nep->next = NULL;
714
715 *needed_tail = nep;
716 needed_tail = &nep->next;
717 }
718 break;
719
720 case DT_PLTGOT:
721 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
722 break;
723
724 case DT_TEXTREL:
725 obj->textrel = true;
726 break;
727
728 case DT_SYMBOLIC:
729 obj->symbolic = true;
730 break;
731
732 case DT_RPATH:
167f7029 733 case DT_RUNPATH: /* XXX: process separately */
984263bc
MD
734 /*
735 * We have to wait until later to process this, because we
736 * might not have gotten the address of the string table yet.
737 */
738 dyn_rpath = dynp;
739 break;
740
741 case DT_SONAME:
742 /* Not used by the dynamic linker. */
743 break;
744
745 case DT_INIT:
746 obj->init = (InitFunc) (obj->relocbase + dynp->d_un.d_ptr);
747 break;
748
749 case DT_FINI:
750 obj->fini = (InitFunc) (obj->relocbase + dynp->d_un.d_ptr);
751 break;
752
753 case DT_DEBUG:
754 /* XXX - not implemented yet */
c3098c28
SS
755 if (!early)
756 dbg("Filling in DT_DEBUG entry");
984263bc
MD
757 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
758 break;
759
167f7029
JS
760 case DT_FLAGS:
761 if (dynp->d_un.d_val & DF_ORIGIN) {
762 obj->origin_path = xmalloc(PATH_MAX);
763 if (rtld_dirname(obj->path, obj->origin_path) == -1)
764 die();
765 }
766 if (dynp->d_un.d_val & DF_SYMBOLIC)
767 obj->symbolic = true;
768 if (dynp->d_un.d_val & DF_TEXTREL)
769 obj->textrel = true;
770 if (dynp->d_un.d_val & DF_BIND_NOW)
771 obj->bind_now = true;
772 if (dynp->d_un.d_val & DF_STATIC_TLS)
773 ;
774 break;
775
984263bc 776 default:
c3098c28
SS
777 if (!early)
778 dbg("Ignoring d_tag %d = %#x", dynp->d_tag, dynp->d_tag);
984263bc
MD
779 break;
780 }
781 }
782
783 obj->traced = false;
784
785 if (plttype == DT_RELA) {
786 obj->pltrela = (const Elf_Rela *) obj->pltrel;
787 obj->pltrel = NULL;
788 obj->pltrelasize = obj->pltrelsize;
789 obj->pltrelsize = 0;
790 }
791
792 if (dyn_rpath != NULL)
793 obj->rpath = obj->strtab + dyn_rpath->d_un.d_val;
794}
795
796/*
797 * Process a shared object's program header. This is used only for the
798 * main program, when the kernel has already loaded the main program
799 * into memory before calling the dynamic linker. It creates and
800 * returns an Obj_Entry structure.
801 */
802static Obj_Entry *
803digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
804{
805 Obj_Entry *obj;
806 const Elf_Phdr *phlimit = phdr + phnum;
807 const Elf_Phdr *ph;
808 int nsegs = 0;
809
810 obj = obj_new();
811 for (ph = phdr; ph < phlimit; ph++) {
812 switch (ph->p_type) {
813
814 case PT_PHDR:
815 if ((const Elf_Phdr *)ph->p_vaddr != phdr) {
816 _rtld_error("%s: invalid PT_PHDR", path);
817 return NULL;
818 }
819 obj->phdr = (const Elf_Phdr *) ph->p_vaddr;
820 obj->phsize = ph->p_memsz;
821 break;
822
823 case PT_INTERP:
824 obj->interp = (const char *) ph->p_vaddr;
825 break;
826
827 case PT_LOAD:
828 if (nsegs == 0) { /* First load segment */
829 obj->vaddrbase = trunc_page(ph->p_vaddr);
830 obj->mapbase = (caddr_t) obj->vaddrbase;
831 obj->relocbase = obj->mapbase - obj->vaddrbase;
832 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
833 obj->vaddrbase;
834 } else { /* Last load segment */
835 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
836 obj->vaddrbase;
837 }
838 nsegs++;
839 break;
840
841 case PT_DYNAMIC:
842 obj->dynamic = (const Elf_Dyn *) ph->p_vaddr;
843 break;
55b88cae
DX
844
845 case PT_TLS:
846 obj->tlsindex = 1;
847 obj->tlssize = ph->p_memsz;
848 obj->tlsalign = ph->p_align;
849 obj->tlsinitsize = ph->p_filesz;
850 obj->tlsinit = (void*) ph->p_vaddr;
851 break;
984263bc
MD
852 }
853 }
854 if (nsegs < 1) {
855 _rtld_error("%s: too few PT_LOAD segments", path);
856 return NULL;
857 }
858
859 obj->entry = entry;
860 return obj;
861}
862
863static Obj_Entry *
864dlcheck(void *handle)
865{
866 Obj_Entry *obj;
867
868 for (obj = obj_list; obj != NULL; obj = obj->next)
869 if (obj == (Obj_Entry *) handle)
870 break;
871
872 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
873 _rtld_error("Invalid shared object handle %p", handle);
874 return NULL;
875 }
876 return obj;
877}
878
879/*
880 * If the given object is already in the donelist, return true. Otherwise
881 * add the object to the list and return false.
882 */
883static bool
884donelist_check(DoneList *dlp, const Obj_Entry *obj)
885{
886 unsigned int i;
887
888 for (i = 0; i < dlp->num_used; i++)
889 if (dlp->objs[i] == obj)
890 return true;
891 /*
892 * Our donelist allocation should always be sufficient. But if
893 * our threads locking isn't working properly, more shared objects
894 * could have been loaded since we allocated the list. That should
895 * never happen, but we'll handle it properly just in case it does.
896 */
897 if (dlp->num_used < dlp->num_alloc)
898 dlp->objs[dlp->num_used++] = obj;
899 return false;
900}
901
902/*
903 * Hash function for symbol table lookup. Don't even think about changing
904 * this. It is specified by the System V ABI.
905 */
906unsigned long
907elf_hash(const char *name)
908{
909 const unsigned char *p = (const unsigned char *) name;
910 unsigned long h = 0;
911 unsigned long g;
912
913 while (*p != '\0') {
914 h = (h << 4) + *p++;
915 if ((g = h & 0xf0000000) != 0)
916 h ^= g >> 24;
917 h &= ~g;
918 }
919 return h;
920}
921
922/*
923 * Find the library with the given name, and return its full pathname.
924 * The returned string is dynamically allocated. Generates an error
925 * message and returns NULL if the library cannot be found.
926 *
927 * If the second argument is non-NULL, then it refers to an already-
928 * loaded shared object, whose library search path will be searched.
929 *
930 * The search order is:
984263bc 931 * LD_LIBRARY_PATH
4e390e27 932 * rpath in the referencing file
984263bc
MD
933 * ldconfig hints
934 * /usr/lib
935 */
936static char *
937find_library(const char *name, const Obj_Entry *refobj)
938{
939 char *pathname;
940
941 if (strchr(name, '/') != NULL) { /* Hard coded pathname */
942 if (name[0] != '/' && !trust) {
943 _rtld_error("Absolute pathname required for shared object \"%s\"",
944 name);
945 return NULL;
946 }
947 return xstrdup(name);
948 }
949
950 dbg(" Searching for \"%s\"", name);
951
952 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
953 (refobj != NULL &&
954 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
955 (pathname = search_library_path(name, gethints())) != NULL ||
956 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
957 return pathname;
958
446c0d3a
JS
959 if(refobj != NULL && refobj->path != NULL) {
960 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
961 name, basename(refobj->path));
962 } else {
963 _rtld_error("Shared object \"%s\" not found", name);
964 }
984263bc
MD
965 return NULL;
966}
967
968/*
969 * Given a symbol number in a referencing object, find the corresponding
970 * definition of the symbol. Returns a pointer to the symbol, or NULL if
971 * no definition was found. Returns a pointer to the Obj_Entry of the
972 * defining object via the reference parameter DEFOBJ_OUT.
973 */
974const Elf_Sym *
975find_symdef(unsigned long symnum, const Obj_Entry *refobj,
976 const Obj_Entry **defobj_out, bool in_plt, SymCache *cache)
977{
978 const Elf_Sym *ref;
979 const Elf_Sym *def;
980 const Obj_Entry *defobj;
981 const char *name;
982 unsigned long hash;
983
984 /*
985 * If we have already found this symbol, get the information from
986 * the cache.
987 */
988 if (symnum >= refobj->nchains)
989 return NULL; /* Bad object */
990 if (cache != NULL && cache[symnum].sym != NULL) {
991 *defobj_out = cache[symnum].obj;
992 return cache[symnum].sym;
993 }
994
995 ref = refobj->symtab + symnum;
996 name = refobj->strtab + ref->st_name;
984263bc
MD
997 defobj = NULL;
998
0e588128
SS
999 /*
1000 * We don't have to do a full scale lookup if the symbol is local.
1001 * We know it will bind to the instance in this load module; to
1002 * which we already have a pointer (ie ref). By not doing a lookup,
1003 * we not only improve performance, but it also avoids unresolvable
1004 * symbols when local symbols are not in the hash table.
1005 *
1006 * This might occur for TLS module relocations, which simply use
1007 * symbol 0.
1008 */
1009 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1010 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
c3098c28
SS
1011 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1012 symnum);
1013 }
0e588128
SS
1014 hash = elf_hash(name);
1015 def = symlook_default(name, hash, refobj, &defobj, in_plt);
1016 } else {
c3098c28
SS
1017 def = ref;
1018 defobj = refobj;
0e588128 1019 }
984263bc
MD
1020
1021 /*
1022 * If we found no definition and the reference is weak, treat the
1023 * symbol as having the value zero.
1024 */
1025 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1026 def = &sym_zero;
1027 defobj = obj_main;
1028 }
1029
1030 if (def != NULL) {
1031 *defobj_out = defobj;
1032 /* Record the information in the cache to avoid subsequent lookups. */
1033 if (cache != NULL) {
1034 cache[symnum].sym = def;
1035 cache[symnum].obj = defobj;
1036 }
1037 } else
1038 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1039 return def;
1040}
1041
1042/*
1043 * Return the search path from the ldconfig hints file, reading it if
1044 * necessary. Returns NULL if there are problems with the hints file,
1045 * or if the search path there is empty.
1046 */
1047static const char *
1048gethints(void)
1049{
1050 static char *hints;
1051
1052 if (hints == NULL) {
1053 int fd;
1054 struct elfhints_hdr hdr;
1055 char *p;
1056
1057 /* Keep from trying again in case the hints file is bad. */
1058 hints = "";
1059
1060 if ((fd = open(_PATH_ELF_HINTS, O_RDONLY)) == -1)
1061 return NULL;
1062 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1063 hdr.magic != ELFHINTS_MAGIC ||
1064 hdr.version != 1) {
1065 close(fd);
1066 return NULL;
1067 }
1068 p = xmalloc(hdr.dirlistlen + 1);
1069 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1070 read(fd, p, hdr.dirlistlen + 1) != hdr.dirlistlen + 1) {
1071 free(p);
1072 close(fd);
1073 return NULL;
1074 }
1075 hints = p;
1076 close(fd);
1077 }
1078 return hints[0] != '\0' ? hints : NULL;
1079}
1080
1081static void
1082init_dag(Obj_Entry *root)
1083{
1084 DoneList donelist;
1085
1086 donelist_init(&donelist);
1087 init_dag1(root, root, &donelist);
1088}
1089
1090static void
1091init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1092{
1093 const Needed_Entry *needed;
1094
1095 if (donelist_check(dlp, obj))
1096 return;
1097 objlist_push_tail(&obj->dldags, root);
1098 objlist_push_tail(&root->dagmembers, obj);
1099 for (needed = obj->needed; needed != NULL; needed = needed->next)
1100 if (needed->obj != NULL)
1101 init_dag1(root, needed->obj, dlp);
1102}
1103
1104/*
1105 * Initialize the dynamic linker. The argument is the address at which
1106 * the dynamic linker has been mapped into memory. The primary task of
1107 * this function is to relocate the dynamic linker.
1108 */
1109static void
1110init_rtld(caddr_t mapbase)
1111{
c3098c28
SS
1112 Obj_Entry objtmp; /* Temporary rtld object */
1113
984263bc
MD
1114 /*
1115 * Conjure up an Obj_Entry structure for the dynamic linker.
1116 *
c3098c28
SS
1117 * The "path" member can't be initialized yet because string constatns
1118 * cannot yet be acessed. Below we will set it correctly.
984263bc 1119 */
c3098c28
SS
1120 objtmp.path = NULL;
1121 objtmp.rtld = true;
1122 objtmp.mapbase = mapbase;
984263bc 1123#ifdef PIC
c3098c28 1124 objtmp.relocbase = mapbase;
984263bc
MD
1125#endif
1126 if (&_DYNAMIC != 0) {
c3098c28
SS
1127 objtmp.dynamic = rtld_dynamic(&objtmp);
1128 digest_dynamic(&objtmp, 1);
1129 assert(objtmp.needed == NULL);
1130 assert(!objtmp.textrel);
984263bc
MD
1131
1132 /*
1133 * Temporarily put the dynamic linker entry into the object list, so
1134 * that symbols can be found.
1135 */
984263bc 1136
c3098c28 1137 relocate_objects(&objtmp, true, &objtmp);
984263bc
MD
1138 }
1139
c3098c28 1140 /* Initialize the object list. */
984263bc 1141 obj_tail = &obj_list;
c3098c28
SS
1142
1143 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1144 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
984263bc
MD
1145
1146 /* Replace the path with a dynamically allocated copy. */
c3098c28 1147 obj_rtld.path = xstrdup(PATH_RTLD);
984263bc
MD
1148
1149 r_debug.r_brk = r_debug_state;
1150 r_debug.r_state = RT_CONSISTENT;
1151}
1152
1153/*
1154 * Add the init functions from a needed object list (and its recursive
1155 * needed objects) to "list". This is not used directly; it is a helper
1156 * function for initlist_add_objects(). The write lock must be held
1157 * when this function is called.
1158 */
1159static void
1160initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1161{
1162 /* Recursively process the successor needed objects. */
1163 if (needed->next != NULL)
1164 initlist_add_neededs(needed->next, list);
1165
1166 /* Process the current needed object. */
1167 if (needed->obj != NULL)
1168 initlist_add_objects(needed->obj, &needed->obj->next, list);
1169}
1170
1171/*
1172 * Scan all of the DAGs rooted in the range of objects from "obj" to
1173 * "tail" and add their init functions to "list". This recurses over
1174 * the DAGs and ensure the proper init ordering such that each object's
1175 * needed libraries are initialized before the object itself. At the
1176 * same time, this function adds the objects to the global finalization
1177 * list "list_fini" in the opposite order. The write lock must be
1178 * held when this function is called.
1179 */
1180static void
1181initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1182{
1183 if (obj->init_done)
1184 return;
1185 obj->init_done = true;
1186
1187 /* Recursively process the successor objects. */
1188 if (&obj->next != tail)
1189 initlist_add_objects(obj->next, tail, list);
1190
1191 /* Recursively process the needed objects. */
1192 if (obj->needed != NULL)
1193 initlist_add_neededs(obj->needed, list);
1194
1195 /* Add the object to the init list. */
1196 if (obj->init != NULL)
1197 objlist_push_tail(list, obj);
1198
1199 /* Add the object to the global fini list in the reverse order. */
1200 if (obj->fini != NULL)
1201 objlist_push_head(&list_fini, obj);
1202}
1203
1204static bool
1205is_exported(const Elf_Sym *def)
1206{
1207 func_ptr_type value;
1208 const func_ptr_type *p;
1209
1210 value = (func_ptr_type)(obj_rtld.relocbase + def->st_value);
1211 for (p = exports; *p != NULL; p++)
1212 if (*p == value)
1213 return true;
1214 return false;
1215}
1216
1217/*
1218 * Given a shared object, traverse its list of needed objects, and load
1219 * each of them. Returns 0 on success. Generates an error message and
1220 * returns -1 on failure.
1221 */
1222static int
1223load_needed_objects(Obj_Entry *first)
1224{
1225 Obj_Entry *obj;
1226
1227 for (obj = first; obj != NULL; obj = obj->next) {
1228 Needed_Entry *needed;
1229
1230 for (needed = obj->needed; needed != NULL; needed = needed->next) {
1231 const char *name = obj->strtab + needed->name;
1232 char *path = find_library(name, obj);
1233
1234 needed->obj = NULL;
1235 if (path == NULL && !ld_tracing)
1236 return -1;
1237
1238 if (path) {
1239 needed->obj = load_object(path);
1240 if (needed->obj == NULL && !ld_tracing)
1241 return -1; /* XXX - cleanup */
1242 }
1243 }
1244 }
1245
1246 return 0;
1247}
1248
1249static int
1250load_preload_objects(void)
1251{
1252 char *p = ld_preload;
1253 static const char delim[] = " \t:;";
1254
1255 if (p == NULL)
eecd52b2 1256 return 0;
984263bc
MD
1257
1258 p += strspn(p, delim);
1259 while (*p != '\0') {
1260 size_t len = strcspn(p, delim);
1261 char *path;
1262 char savech;
1263
1264 savech = p[len];
1265 p[len] = '\0';
1266 if ((path = find_library(p, NULL)) == NULL)
1267 return -1;
1268 if (load_object(path) == NULL)
1269 return -1; /* XXX - cleanup */
1270 p[len] = savech;
1271 p += len;
1272 p += strspn(p, delim);
1273 }
1274 return 0;
1275}
1276
b6a22d96 1277/*
2d6b58a8 1278 * Returns a pointer to the Obj_Entry for the object with the given path.
b6a22d96
JS
1279 * Returns NULL if no matching object was found.
1280 */
1281static Obj_Entry *
1282find_object(const char *path)
1283{
1284 Obj_Entry *obj;
1285
1286 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1287 if (strcmp(obj->path, path) == 0)
1288 return(obj);
1289 }
1290 return(NULL);
1291}
1292
2d6b58a8
JS
1293/*
1294 * Returns a pointer to the Obj_Entry for the object matching device and
1295 * inode of the given path. If no matching object was found, the descriptor
1296 * is returned in fd.
1297 * Returns with obj == NULL && fd == -1 on error.
1298 */
1299static Obj_Entry *
1300find_object2(const char *path, int *fd, struct stat *sb)
1301{
1302 Obj_Entry *obj;
1303
1304 if ((*fd = open(path, O_RDONLY)) == -1) {
1305 _rtld_error("Cannot open \"%s\"", path);
1306 return(NULL);
1307 }
1308
1309 if (fstat(*fd, sb) == -1) {
1310 _rtld_error("Cannot fstat \"%s\"", path);
1311 close(*fd);
1312 *fd = -1;
1313 return NULL;
1314 }
1315
1316 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1317 if (obj->ino == sb->st_ino && obj->dev == sb->st_dev) {
1318 close(*fd);
1319 break;
1320 }
1321 }
1322
1323 return(obj);
1324}
1325
984263bc
MD
1326/*
1327 * Load a shared object into memory, if it is not already loaded. The
1328 * argument must be a string allocated on the heap. This function assumes
1329 * responsibility for freeing it when necessary.
1330 *
1331 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1332 * on failure.
1333 */
1334static Obj_Entry *
1335load_object(char *path)
1336{
1337 Obj_Entry *obj;
1338 int fd = -1;
1339 struct stat sb;
1340
b6a22d96 1341 obj = find_object(path);
2d6b58a8 1342 if (obj != NULL) {
588c673f 1343 obj->refcount++;
2d6b58a8
JS
1344 free(path);
1345 return(obj);
1346 }
984263bc 1347
2d6b58a8 1348 obj = find_object2(path, &fd, &sb);
588c673f
JS
1349 if (obj != NULL) {
1350 obj->refcount++;
2d6b58a8
JS
1351 free(path);
1352 return(obj);
588c673f
JS
1353 } else if (fd == -1) {
1354 free(path);
1355 return(NULL);
984263bc
MD
1356 }
1357
2d6b58a8
JS
1358 dbg("loading \"%s\"", path);
1359 obj = map_object(fd, path, &sb);
1360 close(fd);
1361 if (obj == NULL) {
1362 free(path);
1363 return NULL;
1364 }
984263bc 1365
2d6b58a8 1366 obj->path = path;
c3098c28 1367 digest_dynamic(obj, 0);
984263bc 1368
2d6b58a8
JS
1369 *obj_tail = obj;
1370 obj_tail = &obj->next;
1371 obj_count++;
1372 linkmap_add(obj); /* for GDB & dlinfo() */
984263bc 1373
2d6b58a8
JS
1374 dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1,
1375 obj->path);
1376 if (obj->textrel)
1377 dbg(" WARNING: %s has impure text", obj->path);
984263bc
MD
1378
1379 obj->refcount++;
1380 return obj;
1381}
1382
1383/*
1384 * Check for locking violations and die if one is found.
1385 */
1386static void
1387lock_check(void)
1388{
1389 int rcount, wcount;
1390
1391 rcount = lockinfo.rcount;
1392 wcount = lockinfo.wcount;
1393 assert(rcount >= 0);
1394 assert(wcount >= 0);
1395 if (wcount > 1 || (wcount != 0 && rcount != 0)) {
1396 _rtld_error("Application locking error: %d readers and %d writers"
1397 " in dynamic linker. See DLLOCKINIT(3) in manual pages.",
1398 rcount, wcount);
1399 die();
1400 }
1401}
1402
1403static Obj_Entry *
1404obj_from_addr(const void *addr)
1405{
984263bc
MD
1406 Obj_Entry *obj;
1407
984263bc 1408 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc
MD
1409 if (addr < (void *) obj->mapbase)
1410 continue;
c6873e56 1411 if (addr < (void *) (obj->mapbase + obj->mapsize))
984263bc
MD
1412 return obj;
1413 }
1414 return NULL;
1415}
1416
1417/*
1418 * Call the finalization functions for each of the objects in "list"
1419 * which are unreferenced. All of the objects are expected to have
1420 * non-NULL fini functions.
1421 */
1422static void
1423objlist_call_fini(Objlist *list)
1424{
1425 Objlist_Entry *elm;
1426 char *saved_msg;
1427
1428 /*
1429 * Preserve the current error message since a fini function might
1430 * call into the dynamic linker and overwrite it.
1431 */
1432 saved_msg = errmsg_save();
1433 STAILQ_FOREACH(elm, list, link) {
1434 if (elm->obj->refcount == 0) {
1435 dbg("calling fini function for %s", elm->obj->path);
1436 (*elm->obj->fini)();
1437 }
1438 }
1439 errmsg_restore(saved_msg);
1440}
1441
1442/*
1443 * Call the initialization functions for each of the objects in
1444 * "list". All of the objects are expected to have non-NULL init
1445 * functions.
1446 */
1447static void
1448objlist_call_init(Objlist *list)
1449{
1450 Objlist_Entry *elm;
1451 char *saved_msg;
1452
1453 /*
1454 * Preserve the current error message since an init function might
1455 * call into the dynamic linker and overwrite it.
1456 */
1457 saved_msg = errmsg_save();
1458 STAILQ_FOREACH(elm, list, link) {
1459 dbg("calling init function for %s", elm->obj->path);
1460 (*elm->obj->init)();
1461 }
1462 errmsg_restore(saved_msg);
1463}
1464
1465static void
1466objlist_clear(Objlist *list)
1467{
1468 Objlist_Entry *elm;
1469
1470 while (!STAILQ_EMPTY(list)) {
1471 elm = STAILQ_FIRST(list);
1472 STAILQ_REMOVE_HEAD(list, link);
1473 free(elm);
1474 }
1475}
1476
1477static Objlist_Entry *
1478objlist_find(Objlist *list, const Obj_Entry *obj)
1479{
1480 Objlist_Entry *elm;
1481
1482 STAILQ_FOREACH(elm, list, link)
1483 if (elm->obj == obj)
1484 return elm;
1485 return NULL;
1486}
1487
1488static void
1489objlist_init(Objlist *list)
1490{
1491 STAILQ_INIT(list);
1492}
1493
1494static void
1495objlist_push_head(Objlist *list, Obj_Entry *obj)
1496{
1497 Objlist_Entry *elm;
1498
1499 elm = NEW(Objlist_Entry);
1500 elm->obj = obj;
1501 STAILQ_INSERT_HEAD(list, elm, link);
1502}
1503
1504static void
1505objlist_push_tail(Objlist *list, Obj_Entry *obj)
1506{
1507 Objlist_Entry *elm;
1508
1509 elm = NEW(Objlist_Entry);
1510 elm->obj = obj;
1511 STAILQ_INSERT_TAIL(list, elm, link);
1512}
1513
1514static void
1515objlist_remove(Objlist *list, Obj_Entry *obj)
1516{
1517 Objlist_Entry *elm;
1518
1519 if ((elm = objlist_find(list, obj)) != NULL) {
1520 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1521 free(elm);
1522 }
1523}
1524
1525/*
1526 * Remove all of the unreferenced objects from "list".
1527 */
1528static void
1529objlist_remove_unref(Objlist *list)
1530{
1531 Objlist newlist;
1532 Objlist_Entry *elm;
1533
1534 STAILQ_INIT(&newlist);
1535 while (!STAILQ_EMPTY(list)) {
1536 elm = STAILQ_FIRST(list);
1537 STAILQ_REMOVE_HEAD(list, link);
1538 if (elm->obj->refcount == 0)
1539 free(elm);
1540 else
1541 STAILQ_INSERT_TAIL(&newlist, elm, link);
1542 }
1543 *list = newlist;
1544}
1545
1546/*
1547 * Relocate newly-loaded shared objects. The argument is a pointer to
1548 * the Obj_Entry for the first such object. All objects from the first
1549 * to the end of the list of objects are relocated. Returns 0 on success,
1550 * or -1 on failure.
1551 */
1552static int
c3098c28 1553relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
984263bc
MD
1554{
1555 Obj_Entry *obj;
1556
1557 for (obj = first; obj != NULL; obj = obj->next) {
c3098c28 1558 if (obj != rtldobj)
984263bc
MD
1559 dbg("relocating \"%s\"", obj->path);
1560 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1561 obj->symtab == NULL || obj->strtab == NULL) {
1562 _rtld_error("%s: Shared object has no run-time symbol table",
1563 obj->path);
1564 return -1;
1565 }
1566
1567 if (obj->textrel) {
1568 /* There are relocations to the write-protected text segment. */
1569 if (mprotect(obj->mapbase, obj->textsize,
1570 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1571 _rtld_error("%s: Cannot write-enable text segment: %s",
1572 obj->path, strerror(errno));
1573 return -1;
1574 }
1575 }
1576
1577 /* Process the non-PLT relocations. */
c3098c28 1578 if (reloc_non_plt(obj, rtldobj))
984263bc
MD
1579 return -1;
1580
4b89341e
MD
1581 /*
1582 * Reprotect the text segment. Make sure it is included in the
1583 * core dump since we modified it. This unfortunately causes the
1584 * entire text segment to core-out but we don't have much of a
1585 * choice. We could try to only reenable core dumps on pages
1586 * in which relocations occured but that is likely most of the text
1587 * pages anyway, and even that would not work because the rest of
1588 * the text pages would wind up as a read-only OBJT_DEFAULT object
1589 * (created due to our modifications) backed by the original OBJT_VNODE
1590 * object, and the ELF coredump code is currently only able to dump
1591 * vnode records for pure vnode-backed mappings, not vnode backings
1592 * to memory objects.
1593 */
1594 if (obj->textrel) {
1595 madvise(obj->mapbase, obj->textsize, MADV_CORE);
984263bc
MD
1596 if (mprotect(obj->mapbase, obj->textsize,
1597 PROT_READ|PROT_EXEC) == -1) {
1598 _rtld_error("%s: Cannot write-protect text segment: %s",
1599 obj->path, strerror(errno));
1600 return -1;
1601 }
1602 }
1603
1604 /* Process the PLT relocations. */
1605 if (reloc_plt(obj) == -1)
1606 return -1;
1607 /* Relocate the jump slots if we are doing immediate binding. */
167f7029 1608 if (obj->bind_now || bind_now)
984263bc
MD
1609 if (reloc_jmpslots(obj) == -1)
1610 return -1;
1611
1612
1613 /*
1614 * Set up the magic number and version in the Obj_Entry. These
1615 * were checked in the crt1.o from the original ElfKit, so we
1616 * set them for backward compatibility.
1617 */
1618 obj->magic = RTLD_MAGIC;
1619 obj->version = RTLD_VERSION;
1620
1621 /* Set the special PLT or GOT entries. */
1622 init_pltgot(obj);
1623 }
1624
1625 return 0;
1626}
1627
1628/*
1629 * Cleanup procedure. It will be called (by the atexit mechanism) just
1630 * before the process exits.
1631 */
1632static void
1633rtld_exit(void)
1634{
1635 Obj_Entry *obj;
1636
1637 dbg("rtld_exit()");
1638 /* Clear all the reference counts so the fini functions will be called. */
1639 for (obj = obj_list; obj != NULL; obj = obj->next)
1640 obj->refcount = 0;
1641 objlist_call_fini(&list_fini);
1642 /* No need to remove the items from the list, since we are exiting. */
1643}
1644
1645static void *
1646path_enumerate(const char *path, path_enum_proc callback, void *arg)
1647{
1648 if (path == NULL)
1649 return (NULL);
1650
1651 path += strspn(path, ":;");
1652 while (*path != '\0') {
1653 size_t len;
1654 char *res;
1655
1656 len = strcspn(path, ":;");
1657 res = callback(path, len, arg);
1658
1659 if (res != NULL)
1660 return (res);
1661
1662 path += len;
1663 path += strspn(path, ":;");
1664 }
1665
1666 return (NULL);
1667}
1668
1669struct try_library_args {
1670 const char *name;
1671 size_t namelen;
1672 char *buffer;
1673 size_t buflen;
1674};
1675
1676static void *
1677try_library_path(const char *dir, size_t dirlen, void *param)
1678{
1679 struct try_library_args *arg;
1680
1681 arg = param;
1682 if (*dir == '/' || trust) {
1683 char *pathname;
1684
1685 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
1686 return (NULL);
1687
1688 pathname = arg->buffer;
1689 strncpy(pathname, dir, dirlen);
1690 pathname[dirlen] = '/';
1691 strcpy(pathname + dirlen + 1, arg->name);
1692
1693 dbg(" Trying \"%s\"", pathname);
1694 if (access(pathname, F_OK) == 0) { /* We found it */
1695 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
1696 strcpy(pathname, arg->buffer);
1697 return (pathname);
1698 }
1699 }
1700 return (NULL);
1701}
1702
1703static char *
1704search_library_path(const char *name, const char *path)
1705{
1706 char *p;
1707 struct try_library_args arg;
1708
1709 if (path == NULL)
1710 return NULL;
1711
1712 arg.name = name;
1713 arg.namelen = strlen(name);
1714 arg.buffer = xmalloc(PATH_MAX);
1715 arg.buflen = PATH_MAX;
1716
1717 p = path_enumerate(path, try_library_path, &arg);
1718
1719 free(arg.buffer);
1720
1721 return (p);
1722}
1723
1724int
1725dlclose(void *handle)
1726{
1727 Obj_Entry *root;
1728
1729 wlock_acquire();
1730 root = dlcheck(handle);
1731 if (root == NULL) {
1732 wlock_release();
1733 return -1;
1734 }
1735
1736 /* Unreference the object and its dependencies. */
1737 root->dl_refcount--;
1738 unref_dag(root);
1739
1740 if (root->refcount == 0) {
1741 /*
1742 * The object is no longer referenced, so we must unload it.
1743 * First, call the fini functions with no locks held.
1744 */
1745 wlock_release();
1746 objlist_call_fini(&list_fini);
1747 wlock_acquire();
1748 objlist_remove_unref(&list_fini);
1749
1750 /* Finish cleaning up the newly-unreferenced objects. */
1751 GDB_STATE(RT_DELETE,&root->linkmap);
1752 unload_object(root);
1753 GDB_STATE(RT_CONSISTENT,NULL);
1754 }
1755 wlock_release();
1756 return 0;
1757}
1758
1759const char *
1760dlerror(void)
1761{
1762 char *msg = error_message;
1763 error_message = NULL;
1764 return msg;
1765}
1766
984263bc
MD
1767void *
1768dlopen(const char *name, int mode)
1769{
1770 Obj_Entry **old_obj_tail;
1771 Obj_Entry *obj;
1772 Objlist initlist;
1773 int result;
1774
1775 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
1776 if (ld_tracing != NULL)
1777 environ = (char **)*get_program_var_addr("environ");
1778
1779 objlist_init(&initlist);
1780
1781 wlock_acquire();
1782 GDB_STATE(RT_ADD,NULL);
1783
1784 old_obj_tail = obj_tail;
1785 obj = NULL;
1786 if (name == NULL) {
1787 obj = obj_main;
1788 obj->refcount++;
1789 } else {
1790 char *path = find_library(name, obj_main);
1791 if (path != NULL)
1792 obj = load_object(path);
1793 }
1794
1795 if (obj) {
1796 obj->dl_refcount++;
8ca15ec8 1797 if ((mode & RTLD_GLOBAL) && objlist_find(&list_global, obj) == NULL)
984263bc
MD
1798 objlist_push_tail(&list_global, obj);
1799 mode &= RTLD_MODEMASK;
1800 if (*old_obj_tail != NULL) { /* We loaded something new. */
1801 assert(*old_obj_tail == obj);
1802
1803 result = load_needed_objects(obj);
1804 if (result != -1 && ld_tracing)
1805 goto trace;
1806
1807 if (result == -1 ||
c3098c28
SS
1808 (init_dag(obj), relocate_objects(obj, mode == RTLD_NOW,
1809 &obj_rtld)) == -1) {
984263bc
MD
1810 obj->dl_refcount--;
1811 unref_dag(obj);
1812 if (obj->refcount == 0)
1813 unload_object(obj);
1814 obj = NULL;
1815 } else {
1816 /* Make list of init functions to call. */
1817 initlist_add_objects(obj, &obj->next, &initlist);
1818 }
1819 } else if (ld_tracing)
1820 goto trace;
1821 }
1822
1823 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
1824
1825 /* Call the init functions with no locks held. */
1826 wlock_release();
1827 objlist_call_init(&initlist);
1828 wlock_acquire();
1829 objlist_clear(&initlist);
1830 wlock_release();
1831 return obj;
1832trace:
1833 trace_loaded_objects(obj);
1834 wlock_release();
1835 exit(0);
1836}
1837
1838void *
1839dlsym(void *handle, const char *name)
1840{
1841 const Obj_Entry *obj;
1842 unsigned long hash;
1843 const Elf_Sym *def;
1844 const Obj_Entry *defobj;
1845
1846 hash = elf_hash(name);
1847 def = NULL;
1848 defobj = NULL;
1849
1850 rlock_acquire();
1851 if (handle == NULL || handle == RTLD_NEXT ||
1852 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
1853 void *retaddr;
1854
1855 retaddr = __builtin_return_address(0); /* __GNUC__ only */
1856 if ((obj = obj_from_addr(retaddr)) == NULL) {
1857 _rtld_error("Cannot determine caller's shared object");
1858 rlock_release();
1859 return NULL;
1860 }
1861 if (handle == NULL) { /* Just the caller's shared object. */
1862 def = symlook_obj(name, hash, obj, true);
1863 defobj = obj;
1864 } else if (handle == RTLD_NEXT || /* Objects after caller's */
1865 handle == RTLD_SELF) { /* ... caller included */
1866 if (handle == RTLD_NEXT)
1867 obj = obj->next;
1868 for (; obj != NULL; obj = obj->next) {
1869 if ((def = symlook_obj(name, hash, obj, true)) != NULL) {
1870 defobj = obj;
1871 break;
1872 }
1873 }
1874 } else {
1875 assert(handle == RTLD_DEFAULT);
1876 def = symlook_default(name, hash, obj, &defobj, true);
1877 }
1878 } else {
fb0c631e
SS
1879 DoneList donelist;
1880
984263bc
MD
1881 if ((obj = dlcheck(handle)) == NULL) {
1882 rlock_release();
1883 return NULL;
1884 }
1885
fb0c631e 1886 donelist_init(&donelist);
984263bc 1887 if (obj->mainprog) {
984263bc 1888 /* Search main program and all libraries loaded by it. */
984263bc
MD
1889 def = symlook_list(name, hash, &list_main, &defobj, true,
1890 &donelist);
1891 } else {
cebaf0af
SS
1892 Needed_Entry fake;
1893
1894 /* Search the given object and its needed objects. */
1895 fake.next = NULL;
1896 fake.obj = (Obj_Entry *)obj;
1897 fake.name = 0;
1898 def = symlook_needed(name, hash, &fake, &defobj, true,
fb0c631e 1899 &donelist);
984263bc
MD
1900 }
1901 }
1902
1903 if (def != NULL) {
1904 rlock_release();
1905 return defobj->relocbase + def->st_value;
1906 }
1907
1908 _rtld_error("Undefined symbol \"%s\"", name);
1909 rlock_release();
1910 return NULL;
1911}
1912
1913int
1914dladdr(const void *addr, Dl_info *info)
1915{
1916 const Obj_Entry *obj;
1917 const Elf_Sym *def;
1918 void *symbol_addr;
1919 unsigned long symoffset;
1920
1921 rlock_acquire();
1922 obj = obj_from_addr(addr);
1923 if (obj == NULL) {
1924 _rtld_error("No shared object contains address");
1925 rlock_release();
1926 return 0;
1927 }
1928 info->dli_fname = obj->path;
1929 info->dli_fbase = obj->mapbase;
1930 info->dli_saddr = (void *)0;
1931 info->dli_sname = NULL;
1932
1933 /*
1934 * Walk the symbol list looking for the symbol whose address is
1935 * closest to the address sent in.
1936 */
1937 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
1938 def = obj->symtab + symoffset;
1939
1940 /*
1941 * For skip the symbol if st_shndx is either SHN_UNDEF or
1942 * SHN_COMMON.
1943 */
1944 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
1945 continue;
1946
1947 /*
1948 * If the symbol is greater than the specified address, or if it
1949 * is further away from addr than the current nearest symbol,
1950 * then reject it.
1951 */
1952 symbol_addr = obj->relocbase + def->st_value;
1953 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
1954 continue;
1955
1956 /* Update our idea of the nearest symbol. */
1957 info->dli_sname = obj->strtab + def->st_name;
1958 info->dli_saddr = symbol_addr;
1959
1960 /* Exact match? */
1961 if (info->dli_saddr == addr)
1962 break;
1963 }
1964 rlock_release();
1965 return 1;
1966}
1967
1968int
1969dlinfo(void *handle, int request, void *p)
1970{
1971 const Obj_Entry *obj;
1972 int error;
1973
1974 rlock_acquire();
1975
1976 if (handle == NULL || handle == RTLD_SELF) {
1977 void *retaddr;
1978
1979 retaddr = __builtin_return_address(0); /* __GNUC__ only */
1980 if ((obj = obj_from_addr(retaddr)) == NULL)
1981 _rtld_error("Cannot determine caller's shared object");
1982 } else
1983 obj = dlcheck(handle);
1984
1985 if (obj == NULL) {
1986 rlock_release();
1987 return (-1);
1988 }
1989
1990 error = 0;
1991 switch (request) {
1992 case RTLD_DI_LINKMAP:
1993 *((struct link_map const **)p) = &obj->linkmap;
1994 break;
1995 case RTLD_DI_ORIGIN:
1996 error = rtld_dirname(obj->path, p);
1997 break;
1998
1999 case RTLD_DI_SERINFOSIZE:
2000 case RTLD_DI_SERINFO:
2001 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2002 break;
2003
2004 default:
2005 _rtld_error("Invalid request %d passed to dlinfo()", request);
2006 error = -1;
2007 }
2008
2009 rlock_release();
2010
2011 return (error);
2012}
2013
2014struct fill_search_info_args {
2015 int request;
2016 unsigned int flags;
2017 Dl_serinfo *serinfo;
2018 Dl_serpath *serpath;
2019 char *strspace;
2020};
2021
2022static void *
2023fill_search_info(const char *dir, size_t dirlen, void *param)
2024{
2025 struct fill_search_info_args *arg;
2026
2027 arg = param;
2028
2029 if (arg->request == RTLD_DI_SERINFOSIZE) {
2030 arg->serinfo->dls_cnt ++;
2031 arg->serinfo->dls_size += dirlen + 1;
2032 } else {
2033 struct dl_serpath *s_entry;
2034
2035 s_entry = arg->serpath;
2036 s_entry->dls_name = arg->strspace;
2037 s_entry->dls_flags = arg->flags;
2038
2039 strncpy(arg->strspace, dir, dirlen);
2040 arg->strspace[dirlen] = '\0';
2041
2042 arg->strspace += dirlen + 1;
2043 arg->serpath++;
2044 }
2045
2046 return (NULL);
2047}
2048
2049static int
2050do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2051{
2052 struct dl_serinfo _info;
2053 struct fill_search_info_args args;
2054
2055 args.request = RTLD_DI_SERINFOSIZE;
2056 args.serinfo = &_info;
2057
2058 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2059 _info.dls_cnt = 0;
2060
2061 path_enumerate(ld_library_path, fill_search_info, &args);
2062 path_enumerate(obj->rpath, fill_search_info, &args);
2063 path_enumerate(gethints(), fill_search_info, &args);
2064 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2065
2066
2067 if (request == RTLD_DI_SERINFOSIZE) {
2068 info->dls_size = _info.dls_size;
2069 info->dls_cnt = _info.dls_cnt;
2070 return (0);
2071 }
2072
2073 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2074 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2075 return (-1);
2076 }
2077
2078 args.request = RTLD_DI_SERINFO;
2079 args.serinfo = info;
2080 args.serpath = &info->dls_serpath[0];
2081 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2082
2083 args.flags = LA_SER_LIBPATH;
2084 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2085 return (-1);
2086
2087 args.flags = LA_SER_RUNPATH;
2088 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2089 return (-1);
2090
2091 args.flags = LA_SER_CONFIG;
2092 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2093 return (-1);
2094
2095 args.flags = LA_SER_DEFAULT;
2096 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2097 return (-1);
2098 return (0);
2099}
2100
2101static int
2102rtld_dirname(const char *path, char *bname)
2103{
2104 const char *endp;
2105
2106 /* Empty or NULL string gets treated as "." */
2107 if (path == NULL || *path == '\0') {
2108 bname[0] = '.';
2109 bname[1] = '\0';
2110 return (0);
2111 }
2112
2113 /* Strip trailing slashes */
2114 endp = path + strlen(path) - 1;
2115 while (endp > path && *endp == '/')
2116 endp--;
2117
2118 /* Find the start of the dir */
2119 while (endp > path && *endp != '/')
2120 endp--;
2121
2122 /* Either the dir is "/" or there are no slashes */
2123 if (endp == path) {
2124 bname[0] = *endp == '/' ? '/' : '.';
2125 bname[1] = '\0';
2126 return (0);
2127 } else {
2128 do {
2129 endp--;
2130 } while (endp > path && *endp == '/');
2131 }
2132
2133 if (endp - path + 2 > PATH_MAX)
2134 {
2135 _rtld_error("Filename is too long: %s", path);
2136 return(-1);
2137 }
2138
2139 strncpy(bname, path, endp - path + 1);
2140 bname[endp - path + 1] = '\0';
2141 return (0);
2142}
2143
2144static void
2145linkmap_add(Obj_Entry *obj)
2146{
2147 struct link_map *l = &obj->linkmap;
2148 struct link_map *prev;
2149
2150 obj->linkmap.l_name = obj->path;
2151 obj->linkmap.l_addr = obj->mapbase;
2152 obj->linkmap.l_ld = obj->dynamic;
2153#ifdef __mips__
2154 /* GDB needs load offset on MIPS to use the symbols */
2155 obj->linkmap.l_offs = obj->relocbase;
2156#endif
2157
2158 if (r_debug.r_map == NULL) {
2159 r_debug.r_map = l;
2160 return;
2161 }
2162
2163 /*
2164 * Scan to the end of the list, but not past the entry for the
2165 * dynamic linker, which we want to keep at the very end.
2166 */
2167 for (prev = r_debug.r_map;
2168 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2169 prev = prev->l_next)
2170 ;
2171
2172 /* Link in the new entry. */
2173 l->l_prev = prev;
2174 l->l_next = prev->l_next;
2175 if (l->l_next != NULL)
2176 l->l_next->l_prev = l;
2177 prev->l_next = l;
2178}
2179
2180static void
2181linkmap_delete(Obj_Entry *obj)
2182{
2183 struct link_map *l = &obj->linkmap;
2184
2185 if (l->l_prev == NULL) {
2186 if ((r_debug.r_map = l->l_next) != NULL)
2187 l->l_next->l_prev = NULL;
2188 return;
2189 }
2190
2191 if ((l->l_prev->l_next = l->l_next) != NULL)
2192 l->l_next->l_prev = l->l_prev;
2193}
2194
2195/*
2196 * Function for the debugger to set a breakpoint on to gain control.
2197 *
2198 * The two parameters allow the debugger to easily find and determine
2199 * what the runtime loader is doing and to whom it is doing it.
2200 *
2201 * When the loadhook trap is hit (r_debug_state, set at program
2202 * initialization), the arguments can be found on the stack:
2203 *
2204 * +8 struct link_map *m
2205 * +4 struct r_debug *rd
2206 * +0 RetAddr
2207 */
2208void
2209r_debug_state(struct r_debug* rd, struct link_map *m)
2210{
2211}
2212
2213/*
2214 * Get address of the pointer variable in the main program.
2215 */
2216static const void **
2217get_program_var_addr(const char *name)
2218{
2219 const Obj_Entry *obj;
2220 unsigned long hash;
2221
2222 hash = elf_hash(name);
2223 for (obj = obj_main; obj != NULL; obj = obj->next) {
2224 const Elf_Sym *def;
2225
2226 if ((def = symlook_obj(name, hash, obj, false)) != NULL) {
2227 const void **addr;
2228
2229 addr = (const void **)(obj->relocbase + def->st_value);
2230 return addr;
2231 }
2232 }
2233 return NULL;
2234}
2235
2236/*
2237 * Set a pointer variable in the main program to the given value. This
2238 * is used to set key variables such as "environ" before any of the
2239 * init functions are called.
2240 */
2241static void
2242set_program_var(const char *name, const void *value)
2243{
2244 const void **addr;
2245
2246 if ((addr = get_program_var_addr(name)) != NULL) {
2247 dbg("\"%s\": *%p <-- %p", name, addr, value);
2248 *addr = value;
2249 }
2250}
2251
8ca15ec8
MD
2252/*
2253 * This is a special version of getenv which is far more efficient
2254 * at finding LD_ environment vars.
2255 */
2256static
2257const char *
2258_getenv_ld(const char *id)
2259{
2260 const char *envp;
2261 int i, j;
2262 int idlen = strlen(id);
2263
2264 if (ld_index == LD_ARY_CACHE)
2265 return(getenv(id));
2266 if (ld_index == 0) {
2267 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) {
2268 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_')
2269 ld_ary[j++] = envp;
2270 }
2271 if (j == 0)
2272 ld_ary[j++] = "";
2273 ld_index = j;
2274 }
2275 for (i = ld_index - 1; i >= 0; --i) {
2276 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=')
2277 return(ld_ary[i] + idlen + 1);
2278 }
2279 return(NULL);
2280}
2281
984263bc
MD
2282/*
2283 * Given a symbol name in a referencing object, find the corresponding
2284 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2285 * no definition was found. Returns a pointer to the Obj_Entry of the
2286 * defining object via the reference parameter DEFOBJ_OUT.
2287 */
2288static const Elf_Sym *
2289symlook_default(const char *name, unsigned long hash,
2290 const Obj_Entry *refobj, const Obj_Entry **defobj_out, bool in_plt)
2291{
2292 DoneList donelist;
2293 const Elf_Sym *def;
2294 const Elf_Sym *symp;
2295 const Obj_Entry *obj;
2296 const Obj_Entry *defobj;
2297 const Objlist_Entry *elm;
2298 def = NULL;
2299 defobj = NULL;
2300 donelist_init(&donelist);
2301
2302 /* Look first in the referencing object if linked symbolically. */
2303 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
2304 symp = symlook_obj(name, hash, refobj, in_plt);
2305 if (symp != NULL) {
2306 def = symp;
2307 defobj = refobj;
2308 }
2309 }
2310
2311 /* Search all objects loaded at program start up. */
2312 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2313 symp = symlook_list(name, hash, &list_main, &obj, in_plt, &donelist);
2314 if (symp != NULL &&
2315 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2316 def = symp;
2317 defobj = obj;
2318 }
2319 }
2320
2321 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2322 STAILQ_FOREACH(elm, &list_global, link) {
2323 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2324 break;
2325 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2326 &donelist);
2327 if (symp != NULL &&
2328 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2329 def = symp;
2330 defobj = obj;
2331 }
2332 }
2333
2334 /* Search all dlopened DAGs containing the referencing object. */
2335 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2336 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2337 break;
2338 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2339 &donelist);
2340 if (symp != NULL &&
2341 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2342 def = symp;
2343 defobj = obj;
2344 }
2345 }
2346
2347 /*
2348 * Search the dynamic linker itself, and possibly resolve the
2349 * symbol from there. This is how the application links to
2350 * dynamic linker services such as dlopen. Only the values listed
2351 * in the "exports" array can be resolved from the dynamic linker.
2352 */
2353 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2354 symp = symlook_obj(name, hash, &obj_rtld, in_plt);
2355 if (symp != NULL && is_exported(symp)) {
2356 def = symp;
2357 defobj = &obj_rtld;
2358 }
2359 }
2360
2361 if (def != NULL)
2362 *defobj_out = defobj;
2363 return def;
2364}
2365
2366static const Elf_Sym *
fb0c631e 2367symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
984263bc
MD
2368 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2369{
2370 const Elf_Sym *symp;
2371 const Elf_Sym *def;
2372 const Obj_Entry *defobj;
2373 const Objlist_Entry *elm;
2374
2375 def = NULL;
2376 defobj = NULL;
2377 STAILQ_FOREACH(elm, objlist, link) {
2378 if (donelist_check(dlp, elm->obj))
2379 continue;
2380 if ((symp = symlook_obj(name, hash, elm->obj, in_plt)) != NULL) {
2381 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2382 def = symp;
2383 defobj = elm->obj;
2384 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2385 break;
2386 }
2387 }
2388 }
2389 if (def != NULL)
2390 *defobj_out = defobj;
2391 return def;
2392}
2393
cebaf0af
SS
2394/*
2395 * Search the symbol table of a shared object and all objects needed
2396 * by it for a symbol of the given name. Search order is
2397 * breadth-first. Returns a pointer to the symbol, or NULL if no
2398 * definition was found.
2399 */
2400static const Elf_Sym *
2401symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
2402 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2403{
2404 const Elf_Sym *def, *def_w;
2405 const Needed_Entry *n;
2406 const Obj_Entry *obj, *defobj, *defobj1;
2407
2408 def = def_w = NULL;
2409 defobj = NULL;
2410 for (n = needed; n != NULL; n = n->next) {
2411 if ((obj = n->obj) == NULL ||
2412 donelist_check(dlp, obj) ||
2413 (def = symlook_obj(name, hash, obj, in_plt)) == NULL)
2414 continue;
2415 defobj = obj;
2416 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2417 *defobj_out = defobj;
2418 return (def);
2419 }
2420 }
2421 /*
2422 * There we come when either symbol definition is not found in
2423 * directly needed objects, or found symbol is weak.
2424 */
2425 for (n = needed; n != NULL; n = n->next) {
2426 if ((obj = n->obj) == NULL)
2427 continue;
2428 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
2429 in_plt, dlp);
2430 if (def_w == NULL)
2431 continue;
2432 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
2433 def = def_w;
2434 defobj = defobj1;
2435 }
2436 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
2437 break;
2438 }
2439 if (def != NULL)
2440 *defobj_out = defobj;
2441 return def;
2442}
2443
984263bc
MD
2444/*
2445 * Search the symbol table of a single shared object for a symbol of
2446 * the given name. Returns a pointer to the symbol, or NULL if no
2447 * definition was found.
2448 *
2449 * The symbol's hash value is passed in for efficiency reasons; that
2450 * eliminates many recomputations of the hash value.
2451 */
2452const Elf_Sym *
2453symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
2454 bool in_plt)
2455{
2456 if (obj->buckets != NULL) {
2457 unsigned long symnum = obj->buckets[hash % obj->nbuckets];
2458
2459 while (symnum != STN_UNDEF) {
2460 const Elf_Sym *symp;
2461 const char *strp;
2462
2463 if (symnum >= obj->nchains)
2464 return NULL; /* Bad object */
2465 symp = obj->symtab + symnum;
2466 strp = obj->strtab + symp->st_name;
2467
2468 if (name[0] == strp[0] && strcmp(name, strp) == 0)
2469 return symp->st_shndx != SHN_UNDEF ||
2470 (!in_plt && symp->st_value != 0 &&
2471 ELF_ST_TYPE(symp->st_info) == STT_FUNC) ? symp : NULL;
2472
2473 symnum = obj->chains[symnum];
2474 }
2475 }
2476 return NULL;
2477}
2478
2479static void
2480trace_loaded_objects(Obj_Entry *obj)
2481{
8ca15ec8 2482 const char *fmt1, *fmt2, *fmt, *main_local;
984263bc
MD
2483 int c;
2484
8ca15ec8 2485 if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
984263bc
MD
2486 main_local = "";
2487
8ca15ec8 2488 if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL)
984263bc
MD
2489 fmt1 = "\t%o => %p (%x)\n";
2490
8ca15ec8 2491 if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
984263bc
MD
2492 fmt2 = "\t%o (%x)\n";
2493
2494 for (; obj; obj = obj->next) {
2495 Needed_Entry *needed;
2496 char *name, *path;
2497 bool is_lib;
2498
2499 for (needed = obj->needed; needed; needed = needed->next) {
2500 if (needed->obj != NULL) {
2501 if (needed->obj->traced)
2502 continue;
2503 needed->obj->traced = true;
2504 path = needed->obj->path;
2505 } else
2506 path = "not found";
2507
2508 name = (char *)obj->strtab + needed->name;
2509 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
2510
2511 fmt = is_lib ? fmt1 : fmt2;
2512 while ((c = *fmt++) != '\0') {
2513 switch (c) {
2514 default:
2515 putchar(c);
2516 continue;
2517 case '\\':
2518 switch (c = *fmt) {
2519 case '\0':
2520 continue;
2521 case 'n':
2522 putchar('\n');
2523 break;
2524 case 't':
2525 putchar('\t');
2526 break;
2527 }
2528 break;
2529 case '%':
2530 switch (c = *fmt) {
2531 case '\0':
2532 continue;
2533 case '%':
2534 default:
2535 putchar(c);
2536 break;
2537 case 'A':
2538 printf("%s", main_local);
2539 break;
2540 case 'a':
2541 printf("%s", obj_main->path);
2542 break;
2543 case 'o':
2544 printf("%s", name);
2545 break;
2546#if 0
2547 case 'm':
2548 printf("%d", sodp->sod_major);
2549 break;
2550 case 'n':
2551 printf("%d", sodp->sod_minor);
2552 break;
2553#endif
2554 case 'p':
2555 printf("%s", path);
2556 break;
2557 case 'x':
2558 printf("%p", needed->obj ? needed->obj->mapbase : 0);
2559 break;
2560 }
2561 break;
2562 }
2563 ++fmt;
2564 }
2565 }
2566 }
2567}
2568
2569/*
2570 * Unload a dlopened object and its dependencies from memory and from
2571 * our data structures. It is assumed that the DAG rooted in the
2572 * object has already been unreferenced, and that the object has a
2573 * reference count of 0.
2574 */
2575static void
2576unload_object(Obj_Entry *root)
2577{
2578 Obj_Entry *obj;
2579 Obj_Entry **linkp;
2580
2581 assert(root->refcount == 0);
2582
2583 /*
2584 * Pass over the DAG removing unreferenced objects from
2585 * appropriate lists.
2586 */
2587 unlink_object(root);
2588
2589 /* Unmap all objects that are no longer referenced. */
2590 linkp = &obj_list->next;
2591 while ((obj = *linkp) != NULL) {
2592 if (obj->refcount == 0) {
2593 dbg("unloading \"%s\"", obj->path);
2594 munmap(obj->mapbase, obj->mapsize);
2595 linkmap_delete(obj);
2596 *linkp = obj->next;
2597 obj_count--;
2598 obj_free(obj);
2599 } else
2600 linkp = &obj->next;
2601 }
2602 obj_tail = linkp;
2603}
2604
2605static void
2606unlink_object(Obj_Entry *root)
2607{
2608 const Needed_Entry *needed;
2609 Objlist_Entry *elm;
2610
2611 if (root->refcount == 0) {
2612 /* Remove the object from the RTLD_GLOBAL list. */
2613 objlist_remove(&list_global, root);
2614
2615 /* Remove the object from all objects' DAG lists. */
2616 STAILQ_FOREACH(elm, &root->dagmembers , link)
2617 objlist_remove(&elm->obj->dldags, root);
2618 }
2619
2620 for (needed = root->needed; needed != NULL; needed = needed->next)
2621 if (needed->obj != NULL)
2622 unlink_object(needed->obj);
2623}
2624
2625static void
2626unref_dag(Obj_Entry *root)
2627{
2628 const Needed_Entry *needed;
2629
2630 if (root->refcount == 0)
2631 return;
2632 root->refcount--;
2633 if (root->refcount == 0)
2634 for (needed = root->needed; needed != NULL; needed = needed->next)
2635 if (needed->obj != NULL)
2636 unref_dag(needed->obj);
2637}
55b88cae
DX
2638
2639/*
2640 * Common code for MD __tls_get_addr().
2641 */
2642void *
bc633d63 2643tls_get_addr_common(void **dtvp, int index, size_t offset)
55b88cae
DX
2644{
2645 Elf_Addr* dtv = *dtvp;
2646
2647 /* Check dtv generation in case new modules have arrived */
2648 if (dtv[0] != tls_dtv_generation) {
2649 Elf_Addr* newdtv;
2650 int to_copy;
2651
2652 wlock_acquire();
2653
2654 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
2655 to_copy = dtv[1];
2656 if (to_copy > tls_max_index)
2657 to_copy = tls_max_index;
2658 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
2659 newdtv[0] = tls_dtv_generation;
2660 newdtv[1] = tls_max_index;
2661 free(dtv);
bc633d63 2662 *dtvp = newdtv;
55b88cae
DX
2663
2664 wlock_release();
55b88cae
DX
2665 }
2666
2667 /* Dynamically allocate module TLS if necessary */
2668 if (!dtv[index + 1]) {
2669 /* XXX
2670 * here we should avoid to be re-entered by signal handler
2671 * code, I assume wlock_acquire will masked all signals,
2672 * otherwise there is race and dead lock thread itself.
2673 */
2674 wlock_acquire();
2675 if (!dtv[index + 1])
2676 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
2677 wlock_release();
2678 }
2679
2680 return (void*) (dtv[index + 1] + offset);
2681}
2682
9e2ee207 2683#if defined(RTLD_STATIC_TLS_VARIANT_II)
55b88cae
DX
2684
2685/*
bc633d63
MD
2686 * Allocate the static TLS area. Return a pointer to the TCB. The
2687 * static area is based on negative offsets relative to the tcb.
a1eee96a
MD
2688 *
2689 * The TCB contains an errno pointer for the system call layer, but because
2690 * we are the RTLD we really have no idea how the caller was compiled so
2691 * the information has to be passed in. errno can either be:
2692 *
2693 * type 0 errno is a simple non-TLS global pointer.
2694 * (special case for e.g. libc_rtld)
2695 * type 1 errno accessed by GOT entry (dynamically linked programs)
2696 * type 2 errno accessed by %gs:OFFSET (statically linked programs)
55b88cae 2697 */
bc633d63 2698struct tls_tcb *
a1eee96a 2699allocate_tls(Obj_Entry *objs)
55b88cae
DX
2700{
2701 Obj_Entry *obj;
bc633d63 2702 size_t data_size;
bc633d63
MD
2703 size_t dtv_size;
2704 struct tls_tcb *tcb;
a1eee96a 2705 Elf_Addr *dtv;
bc633d63 2706 Elf_Addr addr;
55b88cae 2707
bc633d63
MD
2708 /*
2709 * Allocate the new TCB. static TLS storage is placed just before the
2710 * TCB to support the %gs:OFFSET (negative offset) model.
2711 */
bc633d63
MD
2712 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
2713 ~RTLD_STATIC_TLS_ALIGN_MASK;
f20fd431 2714 tcb = malloc(data_size + sizeof(*tcb));
bc633d63 2715 tcb = (void *)((char *)tcb + data_size); /* actual tcb location */
55b88cae 2716
bc633d63
MD
2717 dtv_size = (tls_max_index + 2) * sizeof(Elf_Addr);
2718 dtv = malloc(dtv_size);
2719 bzero(dtv, dtv_size);
55b88cae 2720
9e2ee207
JS
2721#ifdef RTLD_TCB_HAS_SELF_POINTER
2722 tcb->tcb_self = tcb;
2723#endif
2724 tcb->tcb_dtv = dtv;
2725 tcb->tcb_pthread = NULL;
55b88cae
DX
2726
2727 dtv[0] = tls_dtv_generation;
2728 dtv[1] = tls_max_index;
2729
a1eee96a
MD
2730 for (obj = objs; obj; obj = obj->next) {
2731 if (obj->tlsoffset) {
2732 addr = (Elf_Addr)tcb - obj->tlsoffset;
2733 memset((void *)(addr + obj->tlsinitsize),
2734 0, obj->tlssize - obj->tlsinitsize);
2735 if (obj->tlsinit)
2736 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
2737 dtv[obj->tlsindex + 1] = addr;
55b88cae
DX
2738 }
2739 }
bc633d63 2740 return(tcb);
55b88cae
DX
2741}
2742
2743void
f20fd431 2744free_tls(struct tls_tcb *tcb)
bc633d63
MD
2745{
2746 Elf_Addr *dtv;
2747 int dtv_size, i;
2748 Elf_Addr tls_start, tls_end;
2749 size_t data_size;
2750
2751 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
2752 ~RTLD_STATIC_TLS_ALIGN_MASK;
9e2ee207 2753 dtv = tcb->tcb_dtv;
bc633d63
MD
2754 dtv_size = dtv[1];
2755 tls_end = (Elf_Addr)tcb;
2756 tls_start = (Elf_Addr)tcb - data_size;
2757 for (i = 0; i < dtv_size; i++) {
eecd52b2 2758 if (dtv[i+2] != 0 && (dtv[i+2] < tls_start || dtv[i+2] > tls_end)) {
bc633d63 2759 free((void *)dtv[i+2]);
55b88cae
DX
2760 }
2761 }
bc633d63 2762 free((void *)tls_start);
55b88cae
DX
2763}
2764
9e2ee207
JS
2765#else
2766#error "Unsupported TLS layout"
55b88cae
DX
2767#endif
2768
2769/*
2770 * Allocate TLS block for module with given index.
2771 */
2772void *
2773allocate_module_tls(int index)
2774{
2775 Obj_Entry* obj;
2776 char* p;
2777
2778 for (obj = obj_list; obj; obj = obj->next) {
2779 if (obj->tlsindex == index)
2780 break;
2781 }
2782 if (!obj) {
2783 _rtld_error("Can't find module with TLS index %d", index);
2784 die();
2785 }
2786
2787 p = malloc(obj->tlssize);
2788 memcpy(p, obj->tlsinit, obj->tlsinitsize);
2789 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
2790
2791 return p;
2792}
2793
2794bool
2795allocate_tls_offset(Obj_Entry *obj)
2796{
2797 size_t off;
2798
2799 if (obj->tls_done)
2800 return true;
2801
2802 if (obj->tlssize == 0) {
2803 obj->tls_done = true;
2804 return true;
2805 }
2806
2807 if (obj->tlsindex == 1)
2808 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
2809 else
2810 off = calculate_tls_offset(tls_last_offset, tls_last_size,
2811 obj->tlssize, obj->tlsalign);
2812
2813 /*
2814 * If we have already fixed the size of the static TLS block, we
2815 * must stay within that size. When allocating the static TLS, we
2816 * leave a small amount of space spare to be used for dynamically
2817 * loading modules which use static TLS.
2818 */
2819 if (tls_static_space) {
2820 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
2821 return false;
2822 }
2823
2824 tls_last_offset = obj->tlsoffset = off;
2825 tls_last_size = obj->tlssize;
2826 obj->tls_done = true;
2827
2828 return true;
2829}
2830
2831void
2832free_tls_offset(Obj_Entry *obj)
2833{
9e2ee207 2834#ifdef RTLD_STATIC_TLS_VARIANT_II
55b88cae
DX
2835 /*
2836 * If we were the last thing to allocate out of the static TLS
2837 * block, we give our space back to the 'allocator'. This is a
2838 * simplistic workaround to allow libGL.so.1 to be loaded and
2839 * unloaded multiple times. We only handle the Variant II
2840 * mechanism for now - this really needs a proper allocator.
2841 */
2842 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
2843 == calculate_tls_end(tls_last_offset, tls_last_size)) {
2844 tls_last_offset -= obj->tlssize;
2845 tls_last_size = 0;
2846 }
2847#endif
2848}
2849
bc633d63 2850struct tls_tcb *
a1eee96a 2851_rtld_allocate_tls(void)
55b88cae 2852{
bc633d63 2853 struct tls_tcb *new_tcb;
55b88cae
DX
2854
2855 wlock_acquire();
a1eee96a 2856 new_tcb = allocate_tls(obj_list);
55b88cae
DX
2857 wlock_release();
2858
bc633d63 2859 return (new_tcb);
55b88cae
DX
2860}
2861
2862void
f20fd431 2863_rtld_free_tls(struct tls_tcb *tcb)
55b88cae
DX
2864{
2865 wlock_acquire();
f20fd431 2866 free_tls(tcb);
55b88cae
DX
2867 wlock_release();
2868}
bc633d63 2869