Use NULL instead of 0 in various places.
[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;
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294
295 /*
296 * On entry, the dynamic linker itself has not been relocated yet.
297 * Be very careful not to reference any global data until after
298 * init_rtld has returned. It is OK to reference file-scope statics
299 * and string constants, and to call static and global functions.
300 */
301
302 /* Find the auxiliary vector on the stack. */
303 argc = *sp++;
304 argv = (char **) sp;
305 sp += argc + 1; /* Skip over arguments and NULL terminator */
306 env = (char **) sp;
984263bc 307
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308 /*
309 * If we aren't already resident we have to dig out some more info.
310 * Note that auxinfo does not exist when we are resident.
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311 *
312 * I'm not sure about the ld_resident check. It seems to read zero
313 * prior to relocation, which is what we want. When running from a
314 * resident copy everything will be relocated so we are definitely
315 * good there.
33a8b578 316 */
5347affc 317 if (ld_resident == 0) {
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MD
318 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
319 ;
320 aux = (Elf_Auxinfo *) sp;
321
322 /* Digest the auxiliary vector. */
323 for (i = 0; i < AT_COUNT; i++)
324 aux_info[i] = NULL;
325 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
326 if (auxp->a_type < AT_COUNT)
327 aux_info[auxp->a_type] = auxp;
328 }
329
330 /* Initialize and relocate ourselves. */
331 assert(aux_info[AT_BASE] != NULL);
332 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
333 }
984263bc 334
5347affc 335 ld_index = 0; /* don't use old env cache in case we are resident */
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MD
336 __progname = obj_rtld.path;
337 argv0 = argv[0] != NULL ? argv[0] : "(null)";
338 environ = env;
339
8ca15ec8 340 trust = (geteuid() == getuid()) && (getegid() == getgid());
984263bc 341
8ca15ec8 342 ld_bind_now = _getenv_ld("LD_BIND_NOW");
984263bc 343 if (trust) {
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MD
344 ld_debug = _getenv_ld("LD_DEBUG");
345 ld_library_path = _getenv_ld("LD_LIBRARY_PATH");
346 ld_preload = (char *)_getenv_ld("LD_PRELOAD");
984263bc 347 }
8ca15ec8 348 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS");
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349
350 if (ld_debug != NULL && *ld_debug != '\0')
351 debug = 1;
352 dbg("%s is initialized, base address = %p", __progname,
353 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
354 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
355 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
356
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357 /*
358 * If we are resident we can skip work that we have already done.
359 * Note that the stack is reset and there is no Elf_Auxinfo
360 * when running from a resident image, and the static globals setup
361 * between here and resident_skip will have already been setup.
362 */
8ca15ec8 363 if (ld_resident)
33a8b578 364 goto resident_skip1;
33a8b578 365
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366 /*
367 * Load the main program, or process its program header if it is
368 * already loaded.
369 */
370 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
371 int fd = aux_info[AT_EXECFD]->a_un.a_val;
372 dbg("loading main program");
373 obj_main = map_object(fd, argv0, NULL);
374 close(fd);
375 if (obj_main == NULL)
376 die();
377 } else { /* Main program already loaded. */
378 const Elf_Phdr *phdr;
379 int phnum;
380 caddr_t entry;
381
382 dbg("processing main program's program header");
383 assert(aux_info[AT_PHDR] != NULL);
384 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
385 assert(aux_info[AT_PHNUM] != NULL);
386 phnum = aux_info[AT_PHNUM]->a_un.a_val;
387 assert(aux_info[AT_PHENT] != NULL);
388 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
389 assert(aux_info[AT_ENTRY] != NULL);
390 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
391 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
392 die();
393 }
394
395 obj_main->path = xstrdup(argv0);
396 obj_main->mainprog = true;
397
398 /*
399 * Get the actual dynamic linker pathname from the executable if
400 * possible. (It should always be possible.) That ensures that
401 * gdb will find the right dynamic linker even if a non-standard
402 * one is being used.
403 */
404 if (obj_main->interp != NULL &&
405 strcmp(obj_main->interp, obj_rtld.path) != 0) {
406 free(obj_rtld.path);
407 obj_rtld.path = xstrdup(obj_main->interp);
b7b05c9f 408 __progname = obj_rtld.path;
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MD
409 }
410
c3098c28 411 digest_dynamic(obj_main, 0);
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412
413 linkmap_add(obj_main);
414 linkmap_add(&obj_rtld);
415
416 /* Link the main program into the list of objects. */
417 *obj_tail = obj_main;
418 obj_tail = &obj_main->next;
419 obj_count++;
420 obj_main->refcount++;
421 /* Make sure we don't call the main program's init and fini functions. */
422 obj_main->init = obj_main->fini = NULL;
423
424 /* Initialize a fake symbol for resolving undefined weak references. */
425 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
426 sym_zero.st_shndx = SHN_ABS;
427
428 dbg("loading LD_PRELOAD libraries");
429 if (load_preload_objects() == -1)
430 die();
431 preload_tail = obj_tail;
432
433 dbg("loading needed objects");
434 if (load_needed_objects(obj_main) == -1)
435 die();
436
437 /* Make a list of all objects loaded at startup. */
438 for (obj = obj_list; obj != NULL; obj = obj->next)
439 objlist_push_tail(&list_main, obj);
440
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441resident_skip1:
442
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443 if (ld_tracing) { /* We're done */
444 trace_loaded_objects(obj_main);
445 exit(0);
446 }
447
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448 if (ld_resident) /* XXX clean this up! */
449 goto resident_skip2;
450
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451 if (getenv("LD_DUMP_REL_PRE") != NULL) {
452 dump_relocations(obj_main);
453 exit (0);
454 }
455
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456 /* setup TLS for main thread */
457 dbg("initializing initial thread local storage");
458 STAILQ_FOREACH(entry, &list_main, link) {
459 /*
460 * Allocate all the initial objects out of the static TLS
461 * block even if they didn't ask for it.
462 */
463 allocate_tls_offset(entry->obj);
464 }
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465
466 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
467
468 /*
469 * Do not try to allocate the TLS here, let libc do it itself.
470 * (crt1 for the program will call _init_tls())
471 */
55b88cae 472
6192271e 473 if (relocate_objects(obj_main,
c3098c28 474 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
6192271e 475 die();
984263bc 476
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MD
477 dbg("doing copy relocations");
478 if (do_copy_relocations(obj_main) == -1)
479 die();
1c76efe5 480
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481resident_skip2:
482
8ca15ec8 483 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) {
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MD
484 if (exec_sys_unregister(-1) < 0) {
485 dbg("exec_sys_unregister failed %d\n", errno);
486 exit(errno);
487 }
488 dbg("exec_sys_unregister success\n");
489 exit(0);
490 }
984263bc 491
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492 if (getenv("LD_DUMP_REL_POST") != NULL) {
493 dump_relocations(obj_main);
494 exit (0);
495 }
496
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497 dbg("initializing key program variables");
498 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
499 set_program_var("environ", env);
500
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501 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) {
502 extern void resident_start(void);
503 ld_resident = 1;
504 if (exec_sys_register(resident_start) < 0) {
505 dbg("exec_sys_register failed %d\n", errno);
506 exit(errno);
507 }
508 dbg("exec_sys_register success\n");
509 exit(0);
510 }
511
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512 dbg("initializing thread locks");
513 lockdflt_init(&lockinfo);
514 lockinfo.thelock = lockinfo.lock_create(lockinfo.context);
515
516 /* Make a list of init functions to call. */
517 objlist_init(&initlist);
518 initlist_add_objects(obj_list, preload_tail, &initlist);
519
520 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
521
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522 /*
523 * Do NOT call the initlist here, give libc a chance to set up
524 * the initial TLS segment. crt1 will then call _rtld_call_init().
525 */
8ca15ec8 526
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527 dbg("transferring control to program entry point = %p", obj_main->entry);
528
529 /* Return the exit procedure and the program entry point. */
530 *exit_proc = rtld_exit;
531 *objp = obj_main;
532 return (func_ptr_type) obj_main->entry;
533}
534
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MD
535/*
536 * Call the initialization list for dynamically loaded libraries.
537 * (called from crt1.c).
538 */
539void
540_rtld_call_init(void)
541{
542 objlist_call_init(&initlist);
543 wlock_acquire();
544 objlist_clear(&initlist);
545 wlock_release();
546}
547
984263bc 548Elf_Addr
4648abf3 549_rtld_bind(Obj_Entry *obj, Elf_Size reloff, void *stack)
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MD
550{
551 const Elf_Rel *rel;
552 const Elf_Sym *def;
553 const Obj_Entry *defobj;
554 Elf_Addr *where;
555 Elf_Addr target;
38e4b3b6 556 int do_reloc = 1;
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557
558 rlock_acquire();
559 if (obj->pltrel)
560 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
561 else
562 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
563
564 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
565 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
566 if (def == NULL)
567 die();
568
569 target = (Elf_Addr)(defobj->relocbase + def->st_value);
570
571 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
572 defobj->strtab + def->st_name, basename(obj->path),
573 (void *)target, basename(defobj->path));
984263bc 574 rlock_release();
38e4b3b6
SS
575
576 /*
577 * If we have a function call tracing hook, and the
578 * hook would like to keep tracing this one function,
579 * prevent the relocation so we will wind up here
580 * the next time again.
581 *
582 * We don't want to functrace calls from the functracer
583 * to avoid recursive loops.
584 */
585 if (rtld_functrace != NULL && obj != rtld_functrace_obj) {
586 if (rtld_functrace(obj->path,
587 defobj->path,
588 defobj->strtab + def->st_name,
589 stack))
590 do_reloc = 0;
591 }
592
593 if (do_reloc)
594 reloc_jmpslot(where, target);
984263bc
MD
595 return target;
596}
597
598/*
599 * Error reporting function. Use it like printf. If formats the message
600 * into a buffer, and sets things up so that the next call to dlerror()
601 * will return the message.
602 */
603void
604_rtld_error(const char *fmt, ...)
605{
606 static char buf[512];
607 va_list ap;
608
609 va_start(ap, fmt);
610 vsnprintf(buf, sizeof buf, fmt, ap);
611 error_message = buf;
612 va_end(ap);
613}
614
615/*
616 * Return a dynamically-allocated copy of the current error message, if any.
617 */
618static char *
619errmsg_save(void)
620{
621 return error_message == NULL ? NULL : xstrdup(error_message);
622}
623
624/*
625 * Restore the current error message from a copy which was previously saved
626 * by errmsg_save(). The copy is freed.
627 */
628static void
629errmsg_restore(char *saved_msg)
630{
631 if (saved_msg == NULL)
632 error_message = NULL;
633 else {
634 _rtld_error("%s", saved_msg);
635 free(saved_msg);
636 }
637}
638
1c76efe5 639const char *
984263bc
MD
640basename(const char *name)
641{
642 const char *p = strrchr(name, '/');
643 return p != NULL ? p + 1 : name;
644}
645
646static void
647die(void)
648{
649 const char *msg = dlerror();
650
651 if (msg == NULL)
652 msg = "Fatal error";
653 errx(1, "%s", msg);
654}
655
656/*
657 * Process a shared object's DYNAMIC section, and save the important
658 * information in its Obj_Entry structure.
659 */
660static void
c3098c28 661digest_dynamic(Obj_Entry *obj, int early)
984263bc
MD
662{
663 const Elf_Dyn *dynp;
664 Needed_Entry **needed_tail = &obj->needed;
665 const Elf_Dyn *dyn_rpath = NULL;
666 int plttype = DT_REL;
667
668 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
669 switch (dynp->d_tag) {
670
671 case DT_REL:
672 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
673 break;
674
675 case DT_RELSZ:
676 obj->relsize = dynp->d_un.d_val;
677 break;
678
679 case DT_RELENT:
680 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
681 break;
682
683 case DT_JMPREL:
684 obj->pltrel = (const Elf_Rel *)
685 (obj->relocbase + dynp->d_un.d_ptr);
686 break;
687
688 case DT_PLTRELSZ:
689 obj->pltrelsize = dynp->d_un.d_val;
690 break;
691
692 case DT_RELA:
693 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
694 break;
695
696 case DT_RELASZ:
697 obj->relasize = dynp->d_un.d_val;
698 break;
699
700 case DT_RELAENT:
701 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
702 break;
703
704 case DT_PLTREL:
705 plttype = dynp->d_un.d_val;
706 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
707 break;
708
709 case DT_SYMTAB:
710 obj->symtab = (const Elf_Sym *)
711 (obj->relocbase + dynp->d_un.d_ptr);
712 break;
713
714 case DT_SYMENT:
715 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
716 break;
717
718 case DT_STRTAB:
719 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
720 break;
721
722 case DT_STRSZ:
723 obj->strsize = dynp->d_un.d_val;
724 break;
725
726 case DT_HASH:
727 {
d697cc44 728 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
984263bc
MD
729 (obj->relocbase + dynp->d_un.d_ptr);
730 obj->nbuckets = hashtab[0];
731 obj->nchains = hashtab[1];
732 obj->buckets = hashtab + 2;
733 obj->chains = obj->buckets + obj->nbuckets;
734 }
735 break;
736
737 case DT_NEEDED:
738 if (!obj->rtld) {
739 Needed_Entry *nep = NEW(Needed_Entry);
740 nep->name = dynp->d_un.d_val;
741 nep->obj = NULL;
742 nep->next = NULL;
743
744 *needed_tail = nep;
745 needed_tail = &nep->next;
746 }
747 break;
748
749 case DT_PLTGOT:
750 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
751 break;
752
753 case DT_TEXTREL:
754 obj->textrel = true;
755 break;
756
757 case DT_SYMBOLIC:
758 obj->symbolic = true;
759 break;
760
761 case DT_RPATH:
167f7029 762 case DT_RUNPATH: /* XXX: process separately */
984263bc
MD
763 /*
764 * We have to wait until later to process this, because we
765 * might not have gotten the address of the string table yet.
766 */
767 dyn_rpath = dynp;
768 break;
769
770 case DT_SONAME:
771 /* Not used by the dynamic linker. */
772 break;
773
774 case DT_INIT:
775 obj->init = (InitFunc) (obj->relocbase + dynp->d_un.d_ptr);
776 break;
777
778 case DT_FINI:
779 obj->fini = (InitFunc) (obj->relocbase + dynp->d_un.d_ptr);
780 break;
781
782 case DT_DEBUG:
783 /* XXX - not implemented yet */
c3098c28
SS
784 if (!early)
785 dbg("Filling in DT_DEBUG entry");
984263bc
MD
786 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
787 break;
788
167f7029
JS
789 case DT_FLAGS:
790 if (dynp->d_un.d_val & DF_ORIGIN) {
791 obj->origin_path = xmalloc(PATH_MAX);
792 if (rtld_dirname(obj->path, obj->origin_path) == -1)
793 die();
794 }
795 if (dynp->d_un.d_val & DF_SYMBOLIC)
796 obj->symbolic = true;
797 if (dynp->d_un.d_val & DF_TEXTREL)
798 obj->textrel = true;
799 if (dynp->d_un.d_val & DF_BIND_NOW)
800 obj->bind_now = true;
801 if (dynp->d_un.d_val & DF_STATIC_TLS)
802 ;
803 break;
804
984263bc 805 default:
c3098c28
SS
806 if (!early)
807 dbg("Ignoring d_tag %d = %#x", dynp->d_tag, dynp->d_tag);
984263bc
MD
808 break;
809 }
810 }
811
812 obj->traced = false;
813
814 if (plttype == DT_RELA) {
815 obj->pltrela = (const Elf_Rela *) obj->pltrel;
816 obj->pltrel = NULL;
817 obj->pltrelasize = obj->pltrelsize;
818 obj->pltrelsize = 0;
819 }
820
821 if (dyn_rpath != NULL)
822 obj->rpath = obj->strtab + dyn_rpath->d_un.d_val;
823}
824
825/*
826 * Process a shared object's program header. This is used only for the
827 * main program, when the kernel has already loaded the main program
828 * into memory before calling the dynamic linker. It creates and
829 * returns an Obj_Entry structure.
830 */
831static Obj_Entry *
832digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
833{
834 Obj_Entry *obj;
835 const Elf_Phdr *phlimit = phdr + phnum;
836 const Elf_Phdr *ph;
837 int nsegs = 0;
838
839 obj = obj_new();
840 for (ph = phdr; ph < phlimit; ph++) {
841 switch (ph->p_type) {
842
843 case PT_PHDR:
844 if ((const Elf_Phdr *)ph->p_vaddr != phdr) {
845 _rtld_error("%s: invalid PT_PHDR", path);
846 return NULL;
847 }
848 obj->phdr = (const Elf_Phdr *) ph->p_vaddr;
849 obj->phsize = ph->p_memsz;
850 break;
851
852 case PT_INTERP:
853 obj->interp = (const char *) ph->p_vaddr;
854 break;
855
856 case PT_LOAD:
857 if (nsegs == 0) { /* First load segment */
858 obj->vaddrbase = trunc_page(ph->p_vaddr);
859 obj->mapbase = (caddr_t) obj->vaddrbase;
860 obj->relocbase = obj->mapbase - obj->vaddrbase;
861 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
862 obj->vaddrbase;
863 } else { /* Last load segment */
864 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
865 obj->vaddrbase;
866 }
867 nsegs++;
868 break;
869
870 case PT_DYNAMIC:
871 obj->dynamic = (const Elf_Dyn *) ph->p_vaddr;
872 break;
55b88cae
DX
873
874 case PT_TLS:
875 obj->tlsindex = 1;
876 obj->tlssize = ph->p_memsz;
877 obj->tlsalign = ph->p_align;
878 obj->tlsinitsize = ph->p_filesz;
879 obj->tlsinit = (void*) ph->p_vaddr;
880 break;
984263bc
MD
881 }
882 }
883 if (nsegs < 1) {
884 _rtld_error("%s: too few PT_LOAD segments", path);
885 return NULL;
886 }
887
888 obj->entry = entry;
889 return obj;
890}
891
892static Obj_Entry *
893dlcheck(void *handle)
894{
895 Obj_Entry *obj;
896
897 for (obj = obj_list; obj != NULL; obj = obj->next)
898 if (obj == (Obj_Entry *) handle)
899 break;
900
901 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
902 _rtld_error("Invalid shared object handle %p", handle);
903 return NULL;
904 }
905 return obj;
906}
907
908/*
909 * If the given object is already in the donelist, return true. Otherwise
910 * add the object to the list and return false.
911 */
912static bool
913donelist_check(DoneList *dlp, const Obj_Entry *obj)
914{
915 unsigned int i;
916
917 for (i = 0; i < dlp->num_used; i++)
918 if (dlp->objs[i] == obj)
919 return true;
920 /*
921 * Our donelist allocation should always be sufficient. But if
922 * our threads locking isn't working properly, more shared objects
923 * could have been loaded since we allocated the list. That should
924 * never happen, but we'll handle it properly just in case it does.
925 */
926 if (dlp->num_used < dlp->num_alloc)
927 dlp->objs[dlp->num_used++] = obj;
928 return false;
929}
930
931/*
932 * Hash function for symbol table lookup. Don't even think about changing
933 * this. It is specified by the System V ABI.
934 */
935unsigned long
936elf_hash(const char *name)
937{
938 const unsigned char *p = (const unsigned char *) name;
939 unsigned long h = 0;
940 unsigned long g;
941
942 while (*p != '\0') {
943 h = (h << 4) + *p++;
944 if ((g = h & 0xf0000000) != 0)
945 h ^= g >> 24;
946 h &= ~g;
947 }
948 return h;
949}
950
951/*
952 * Find the library with the given name, and return its full pathname.
953 * The returned string is dynamically allocated. Generates an error
954 * message and returns NULL if the library cannot be found.
955 *
956 * If the second argument is non-NULL, then it refers to an already-
957 * loaded shared object, whose library search path will be searched.
958 *
959 * The search order is:
984263bc 960 * LD_LIBRARY_PATH
4e390e27 961 * rpath in the referencing file
984263bc
MD
962 * ldconfig hints
963 * /usr/lib
964 */
965static char *
966find_library(const char *name, const Obj_Entry *refobj)
967{
968 char *pathname;
969
970 if (strchr(name, '/') != NULL) { /* Hard coded pathname */
971 if (name[0] != '/' && !trust) {
972 _rtld_error("Absolute pathname required for shared object \"%s\"",
973 name);
974 return NULL;
975 }
976 return xstrdup(name);
977 }
978
979 dbg(" Searching for \"%s\"", name);
980
981 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
982 (refobj != NULL &&
983 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
984 (pathname = search_library_path(name, gethints())) != NULL ||
985 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
986 return pathname;
987
446c0d3a
JS
988 if(refobj != NULL && refobj->path != NULL) {
989 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
990 name, basename(refobj->path));
991 } else {
992 _rtld_error("Shared object \"%s\" not found", name);
993 }
984263bc
MD
994 return NULL;
995}
996
997/*
998 * Given a symbol number in a referencing object, find the corresponding
999 * definition of the symbol. Returns a pointer to the symbol, or NULL if
1000 * no definition was found. Returns a pointer to the Obj_Entry of the
1001 * defining object via the reference parameter DEFOBJ_OUT.
1002 */
1003const Elf_Sym *
1004find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1005 const Obj_Entry **defobj_out, bool in_plt, SymCache *cache)
1006{
1007 const Elf_Sym *ref;
1008 const Elf_Sym *def;
1009 const Obj_Entry *defobj;
1010 const char *name;
1011 unsigned long hash;
1012
1013 /*
1014 * If we have already found this symbol, get the information from
1015 * the cache.
1016 */
1017 if (symnum >= refobj->nchains)
1018 return NULL; /* Bad object */
1019 if (cache != NULL && cache[symnum].sym != NULL) {
1020 *defobj_out = cache[symnum].obj;
1021 return cache[symnum].sym;
1022 }
1023
1024 ref = refobj->symtab + symnum;
1025 name = refobj->strtab + ref->st_name;
984263bc
MD
1026 defobj = NULL;
1027
0e588128
SS
1028 /*
1029 * We don't have to do a full scale lookup if the symbol is local.
1030 * We know it will bind to the instance in this load module; to
1031 * which we already have a pointer (ie ref). By not doing a lookup,
1032 * we not only improve performance, but it also avoids unresolvable
1033 * symbols when local symbols are not in the hash table.
1034 *
1035 * This might occur for TLS module relocations, which simply use
1036 * symbol 0.
1037 */
1038 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1039 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
c3098c28
SS
1040 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1041 symnum);
1042 }
0e588128
SS
1043 hash = elf_hash(name);
1044 def = symlook_default(name, hash, refobj, &defobj, in_plt);
1045 } else {
c3098c28
SS
1046 def = ref;
1047 defobj = refobj;
0e588128 1048 }
984263bc
MD
1049
1050 /*
1051 * If we found no definition and the reference is weak, treat the
1052 * symbol as having the value zero.
1053 */
1054 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1055 def = &sym_zero;
1056 defobj = obj_main;
1057 }
1058
1059 if (def != NULL) {
1060 *defobj_out = defobj;
1061 /* Record the information in the cache to avoid subsequent lookups. */
1062 if (cache != NULL) {
1063 cache[symnum].sym = def;
1064 cache[symnum].obj = defobj;
1065 }
1066 } else
1067 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1068 return def;
1069}
1070
1071/*
1072 * Return the search path from the ldconfig hints file, reading it if
1073 * necessary. Returns NULL if there are problems with the hints file,
1074 * or if the search path there is empty.
1075 */
1076static const char *
1077gethints(void)
1078{
1079 static char *hints;
1080
1081 if (hints == NULL) {
1082 int fd;
1083 struct elfhints_hdr hdr;
1084 char *p;
1085
1086 /* Keep from trying again in case the hints file is bad. */
1087 hints = "";
1088
1089 if ((fd = open(_PATH_ELF_HINTS, O_RDONLY)) == -1)
1090 return NULL;
1091 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1092 hdr.magic != ELFHINTS_MAGIC ||
1093 hdr.version != 1) {
1094 close(fd);
1095 return NULL;
1096 }
1097 p = xmalloc(hdr.dirlistlen + 1);
1098 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1099 read(fd, p, hdr.dirlistlen + 1) != hdr.dirlistlen + 1) {
1100 free(p);
1101 close(fd);
1102 return NULL;
1103 }
1104 hints = p;
1105 close(fd);
1106 }
1107 return hints[0] != '\0' ? hints : NULL;
1108}
1109
1110static void
1111init_dag(Obj_Entry *root)
1112{
1113 DoneList donelist;
1114
1115 donelist_init(&donelist);
1116 init_dag1(root, root, &donelist);
1117}
1118
1119static void
1120init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1121{
1122 const Needed_Entry *needed;
1123
1124 if (donelist_check(dlp, obj))
1125 return;
1126 objlist_push_tail(&obj->dldags, root);
1127 objlist_push_tail(&root->dagmembers, obj);
1128 for (needed = obj->needed; needed != NULL; needed = needed->next)
1129 if (needed->obj != NULL)
1130 init_dag1(root, needed->obj, dlp);
1131}
1132
1133/*
1134 * Initialize the dynamic linker. The argument is the address at which
1135 * the dynamic linker has been mapped into memory. The primary task of
1136 * this function is to relocate the dynamic linker.
1137 */
1138static void
1139init_rtld(caddr_t mapbase)
1140{
c3098c28
SS
1141 Obj_Entry objtmp; /* Temporary rtld object */
1142
984263bc
MD
1143 /*
1144 * Conjure up an Obj_Entry structure for the dynamic linker.
1145 *
c3098c28
SS
1146 * The "path" member can't be initialized yet because string constatns
1147 * cannot yet be acessed. Below we will set it correctly.
984263bc 1148 */
4648abf3 1149 memset(&objtmp, 0, sizeof(objtmp));
c3098c28
SS
1150 objtmp.path = NULL;
1151 objtmp.rtld = true;
1152 objtmp.mapbase = mapbase;
984263bc 1153#ifdef PIC
c3098c28 1154 objtmp.relocbase = mapbase;
984263bc
MD
1155#endif
1156 if (&_DYNAMIC != 0) {
c3098c28
SS
1157 objtmp.dynamic = rtld_dynamic(&objtmp);
1158 digest_dynamic(&objtmp, 1);
1159 assert(objtmp.needed == NULL);
1160 assert(!objtmp.textrel);
984263bc
MD
1161
1162 /*
1163 * Temporarily put the dynamic linker entry into the object list, so
1164 * that symbols can be found.
1165 */
984263bc 1166
c3098c28 1167 relocate_objects(&objtmp, true, &objtmp);
984263bc
MD
1168 }
1169
c3098c28 1170 /* Initialize the object list. */
984263bc 1171 obj_tail = &obj_list;
c3098c28
SS
1172
1173 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1174 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
984263bc
MD
1175
1176 /* Replace the path with a dynamically allocated copy. */
c3098c28 1177 obj_rtld.path = xstrdup(PATH_RTLD);
984263bc
MD
1178
1179 r_debug.r_brk = r_debug_state;
1180 r_debug.r_state = RT_CONSISTENT;
1181}
1182
1183/*
1184 * Add the init functions from a needed object list (and its recursive
1185 * needed objects) to "list". This is not used directly; it is a helper
1186 * function for initlist_add_objects(). The write lock must be held
1187 * when this function is called.
1188 */
1189static void
1190initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1191{
1192 /* Recursively process the successor needed objects. */
1193 if (needed->next != NULL)
1194 initlist_add_neededs(needed->next, list);
1195
1196 /* Process the current needed object. */
1197 if (needed->obj != NULL)
1198 initlist_add_objects(needed->obj, &needed->obj->next, list);
1199}
1200
1201/*
1202 * Scan all of the DAGs rooted in the range of objects from "obj" to
1203 * "tail" and add their init functions to "list". This recurses over
1204 * the DAGs and ensure the proper init ordering such that each object's
1205 * needed libraries are initialized before the object itself. At the
1206 * same time, this function adds the objects to the global finalization
1207 * list "list_fini" in the opposite order. The write lock must be
1208 * held when this function is called.
1209 */
1210static void
1211initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1212{
1213 if (obj->init_done)
1214 return;
1215 obj->init_done = true;
1216
1217 /* Recursively process the successor objects. */
1218 if (&obj->next != tail)
1219 initlist_add_objects(obj->next, tail, list);
1220
1221 /* Recursively process the needed objects. */
1222 if (obj->needed != NULL)
1223 initlist_add_neededs(obj->needed, list);
1224
1225 /* Add the object to the init list. */
1226 if (obj->init != NULL)
1227 objlist_push_tail(list, obj);
1228
1229 /* Add the object to the global fini list in the reverse order. */
1230 if (obj->fini != NULL)
1231 objlist_push_head(&list_fini, obj);
1232}
1233
1234static bool
1235is_exported(const Elf_Sym *def)
1236{
d697cc44 1237 Elf_Addr value;
984263bc
MD
1238 const func_ptr_type *p;
1239
d697cc44
MD
1240 value = (Elf_Addr)(obj_rtld.relocbase + def->st_value);
1241 for (p = exports; *p != NULL; p++) {
1242 if ((Elf_Addr)(*p) == value)
984263bc 1243 return true;
d697cc44 1244 }
984263bc
MD
1245 return false;
1246}
1247
1248/*
1249 * Given a shared object, traverse its list of needed objects, and load
1250 * each of them. Returns 0 on success. Generates an error message and
1251 * returns -1 on failure.
1252 */
1253static int
1254load_needed_objects(Obj_Entry *first)
1255{
1256 Obj_Entry *obj;
1257
1258 for (obj = first; obj != NULL; obj = obj->next) {
1259 Needed_Entry *needed;
1260
1261 for (needed = obj->needed; needed != NULL; needed = needed->next) {
1262 const char *name = obj->strtab + needed->name;
1263 char *path = find_library(name, obj);
1264
1265 needed->obj = NULL;
1266 if (path == NULL && !ld_tracing)
1267 return -1;
1268
1269 if (path) {
1270 needed->obj = load_object(path);
1271 if (needed->obj == NULL && !ld_tracing)
1272 return -1; /* XXX - cleanup */
1273 }
1274 }
1275 }
1276
1277 return 0;
1278}
1279
38e4b3b6
SS
1280#define RTLD_FUNCTRACE "_rtld_functrace"
1281
984263bc
MD
1282static int
1283load_preload_objects(void)
1284{
1285 char *p = ld_preload;
1286 static const char delim[] = " \t:;";
1287
1288 if (p == NULL)
eecd52b2 1289 return 0;
984263bc
MD
1290
1291 p += strspn(p, delim);
1292 while (*p != '\0') {
1293 size_t len = strcspn(p, delim);
1294 char *path;
1295 char savech;
38e4b3b6
SS
1296 Obj_Entry *obj;
1297 const Elf_Sym *sym;
984263bc
MD
1298
1299 savech = p[len];
1300 p[len] = '\0';
1301 if ((path = find_library(p, NULL)) == NULL)
1302 return -1;
38e4b3b6
SS
1303 obj = load_object(path);
1304 if (obj == NULL)
984263bc
MD
1305 return -1; /* XXX - cleanup */
1306 p[len] = savech;
1307 p += len;
1308 p += strspn(p, delim);
38e4b3b6
SS
1309
1310 /* Check for the magic tracing function */
1311 sym = symlook_obj(RTLD_FUNCTRACE, elf_hash(RTLD_FUNCTRACE), obj, true);
1312 if (sym != NULL) {
1313 rtld_functrace = (void *)(obj->relocbase + sym->st_value);
1314 rtld_functrace_obj = obj;
1315 }
984263bc
MD
1316 }
1317 return 0;
1318}
1319
b6a22d96 1320/*
2d6b58a8 1321 * Returns a pointer to the Obj_Entry for the object with the given path.
b6a22d96
JS
1322 * Returns NULL if no matching object was found.
1323 */
1324static Obj_Entry *
1325find_object(const char *path)
1326{
1327 Obj_Entry *obj;
1328
1329 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1330 if (strcmp(obj->path, path) == 0)
1331 return(obj);
1332 }
1333 return(NULL);
1334}
1335
2d6b58a8
JS
1336/*
1337 * Returns a pointer to the Obj_Entry for the object matching device and
1338 * inode of the given path. If no matching object was found, the descriptor
1339 * is returned in fd.
1340 * Returns with obj == NULL && fd == -1 on error.
1341 */
1342static Obj_Entry *
1343find_object2(const char *path, int *fd, struct stat *sb)
1344{
1345 Obj_Entry *obj;
1346
1347 if ((*fd = open(path, O_RDONLY)) == -1) {
1348 _rtld_error("Cannot open \"%s\"", path);
1349 return(NULL);
1350 }
1351
1352 if (fstat(*fd, sb) == -1) {
1353 _rtld_error("Cannot fstat \"%s\"", path);
1354 close(*fd);
1355 *fd = -1;
1356 return NULL;
1357 }
1358
1359 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1360 if (obj->ino == sb->st_ino && obj->dev == sb->st_dev) {
1361 close(*fd);
1362 break;
1363 }
1364 }
1365
1366 return(obj);
1367}
1368
984263bc
MD
1369/*
1370 * Load a shared object into memory, if it is not already loaded. The
1371 * argument must be a string allocated on the heap. This function assumes
1372 * responsibility for freeing it when necessary.
1373 *
1374 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1375 * on failure.
1376 */
1377static Obj_Entry *
1378load_object(char *path)
1379{
1380 Obj_Entry *obj;
1381 int fd = -1;
1382 struct stat sb;
1383
b6a22d96 1384 obj = find_object(path);
2d6b58a8 1385 if (obj != NULL) {
588c673f 1386 obj->refcount++;
2d6b58a8
JS
1387 free(path);
1388 return(obj);
1389 }
984263bc 1390
2d6b58a8 1391 obj = find_object2(path, &fd, &sb);
588c673f
JS
1392 if (obj != NULL) {
1393 obj->refcount++;
2d6b58a8
JS
1394 free(path);
1395 return(obj);
588c673f
JS
1396 } else if (fd == -1) {
1397 free(path);
1398 return(NULL);
984263bc
MD
1399 }
1400
2d6b58a8
JS
1401 dbg("loading \"%s\"", path);
1402 obj = map_object(fd, path, &sb);
1403 close(fd);
1404 if (obj == NULL) {
1405 free(path);
1406 return NULL;
1407 }
984263bc 1408
2d6b58a8 1409 obj->path = path;
c3098c28 1410 digest_dynamic(obj, 0);
984263bc 1411
2d6b58a8
JS
1412 *obj_tail = obj;
1413 obj_tail = &obj->next;
1414 obj_count++;
1415 linkmap_add(obj); /* for GDB & dlinfo() */
984263bc 1416
2d6b58a8
JS
1417 dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1,
1418 obj->path);
1419 if (obj->textrel)
1420 dbg(" WARNING: %s has impure text", obj->path);
984263bc
MD
1421
1422 obj->refcount++;
1423 return obj;
1424}
1425
1426/*
1427 * Check for locking violations and die if one is found.
1428 */
1429static void
1430lock_check(void)
1431{
1432 int rcount, wcount;
1433
1434 rcount = lockinfo.rcount;
1435 wcount = lockinfo.wcount;
1436 assert(rcount >= 0);
1437 assert(wcount >= 0);
1438 if (wcount > 1 || (wcount != 0 && rcount != 0)) {
1439 _rtld_error("Application locking error: %d readers and %d writers"
1440 " in dynamic linker. See DLLOCKINIT(3) in manual pages.",
1441 rcount, wcount);
1442 die();
1443 }
1444}
1445
1446static Obj_Entry *
1447obj_from_addr(const void *addr)
1448{
984263bc
MD
1449 Obj_Entry *obj;
1450
984263bc 1451 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc
MD
1452 if (addr < (void *) obj->mapbase)
1453 continue;
c6873e56 1454 if (addr < (void *) (obj->mapbase + obj->mapsize))
984263bc
MD
1455 return obj;
1456 }
1457 return NULL;
1458}
1459
1460/*
1461 * Call the finalization functions for each of the objects in "list"
1462 * which are unreferenced. All of the objects are expected to have
1463 * non-NULL fini functions.
1464 */
1465static void
1466objlist_call_fini(Objlist *list)
1467{
1468 Objlist_Entry *elm;
1469 char *saved_msg;
1470
1471 /*
1472 * Preserve the current error message since a fini function might
1473 * call into the dynamic linker and overwrite it.
1474 */
1475 saved_msg = errmsg_save();
1476 STAILQ_FOREACH(elm, list, link) {
1477 if (elm->obj->refcount == 0) {
1478 dbg("calling fini function for %s", elm->obj->path);
1479 (*elm->obj->fini)();
1480 }
1481 }
1482 errmsg_restore(saved_msg);
1483}
1484
1485/*
1486 * Call the initialization functions for each of the objects in
1487 * "list". All of the objects are expected to have non-NULL init
1488 * functions.
1489 */
1490static void
1491objlist_call_init(Objlist *list)
1492{
1493 Objlist_Entry *elm;
1494 char *saved_msg;
1495
1496 /*
1497 * Preserve the current error message since an init function might
1498 * call into the dynamic linker and overwrite it.
1499 */
1500 saved_msg = errmsg_save();
1501 STAILQ_FOREACH(elm, list, link) {
1502 dbg("calling init function for %s", elm->obj->path);
1503 (*elm->obj->init)();
1504 }
1505 errmsg_restore(saved_msg);
1506}
1507
1508static void
1509objlist_clear(Objlist *list)
1510{
1511 Objlist_Entry *elm;
1512
1513 while (!STAILQ_EMPTY(list)) {
1514 elm = STAILQ_FIRST(list);
1515 STAILQ_REMOVE_HEAD(list, link);
1516 free(elm);
1517 }
1518}
1519
1520static Objlist_Entry *
1521objlist_find(Objlist *list, const Obj_Entry *obj)
1522{
1523 Objlist_Entry *elm;
1524
1525 STAILQ_FOREACH(elm, list, link)
1526 if (elm->obj == obj)
1527 return elm;
1528 return NULL;
1529}
1530
1531static void
1532objlist_init(Objlist *list)
1533{
1534 STAILQ_INIT(list);
1535}
1536
1537static void
1538objlist_push_head(Objlist *list, Obj_Entry *obj)
1539{
1540 Objlist_Entry *elm;
1541
1542 elm = NEW(Objlist_Entry);
1543 elm->obj = obj;
1544 STAILQ_INSERT_HEAD(list, elm, link);
1545}
1546
1547static void
1548objlist_push_tail(Objlist *list, Obj_Entry *obj)
1549{
1550 Objlist_Entry *elm;
1551
1552 elm = NEW(Objlist_Entry);
1553 elm->obj = obj;
1554 STAILQ_INSERT_TAIL(list, elm, link);
1555}
1556
1557static void
1558objlist_remove(Objlist *list, Obj_Entry *obj)
1559{
1560 Objlist_Entry *elm;
1561
1562 if ((elm = objlist_find(list, obj)) != NULL) {
1563 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1564 free(elm);
1565 }
1566}
1567
1568/*
1569 * Remove all of the unreferenced objects from "list".
1570 */
1571static void
1572objlist_remove_unref(Objlist *list)
1573{
1574 Objlist newlist;
1575 Objlist_Entry *elm;
1576
1577 STAILQ_INIT(&newlist);
1578 while (!STAILQ_EMPTY(list)) {
1579 elm = STAILQ_FIRST(list);
1580 STAILQ_REMOVE_HEAD(list, link);
1581 if (elm->obj->refcount == 0)
1582 free(elm);
1583 else
1584 STAILQ_INSERT_TAIL(&newlist, elm, link);
1585 }
1586 *list = newlist;
1587}
1588
1589/*
1590 * Relocate newly-loaded shared objects. The argument is a pointer to
1591 * the Obj_Entry for the first such object. All objects from the first
1592 * to the end of the list of objects are relocated. Returns 0 on success,
1593 * or -1 on failure.
1594 */
1595static int
c3098c28 1596relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
984263bc
MD
1597{
1598 Obj_Entry *obj;
1599
1600 for (obj = first; obj != NULL; obj = obj->next) {
c3098c28 1601 if (obj != rtldobj)
984263bc
MD
1602 dbg("relocating \"%s\"", obj->path);
1603 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1604 obj->symtab == NULL || obj->strtab == NULL) {
1605 _rtld_error("%s: Shared object has no run-time symbol table",
1606 obj->path);
1607 return -1;
1608 }
1609
1610 if (obj->textrel) {
1611 /* There are relocations to the write-protected text segment. */
1612 if (mprotect(obj->mapbase, obj->textsize,
1613 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1614 _rtld_error("%s: Cannot write-enable text segment: %s",
1615 obj->path, strerror(errno));
1616 return -1;
1617 }
1618 }
1619
1620 /* Process the non-PLT relocations. */
c3098c28 1621 if (reloc_non_plt(obj, rtldobj))
984263bc
MD
1622 return -1;
1623
4b89341e
MD
1624 /*
1625 * Reprotect the text segment. Make sure it is included in the
1626 * core dump since we modified it. This unfortunately causes the
1627 * entire text segment to core-out but we don't have much of a
1628 * choice. We could try to only reenable core dumps on pages
1629 * in which relocations occured but that is likely most of the text
1630 * pages anyway, and even that would not work because the rest of
1631 * the text pages would wind up as a read-only OBJT_DEFAULT object
1632 * (created due to our modifications) backed by the original OBJT_VNODE
1633 * object, and the ELF coredump code is currently only able to dump
1634 * vnode records for pure vnode-backed mappings, not vnode backings
1635 * to memory objects.
1636 */
1637 if (obj->textrel) {
1638 madvise(obj->mapbase, obj->textsize, MADV_CORE);
984263bc
MD
1639 if (mprotect(obj->mapbase, obj->textsize,
1640 PROT_READ|PROT_EXEC) == -1) {
1641 _rtld_error("%s: Cannot write-protect text segment: %s",
1642 obj->path, strerror(errno));
1643 return -1;
1644 }
1645 }
1646
1647 /* Process the PLT relocations. */
1648 if (reloc_plt(obj) == -1)
1649 return -1;
1650 /* Relocate the jump slots if we are doing immediate binding. */
167f7029 1651 if (obj->bind_now || bind_now)
984263bc
MD
1652 if (reloc_jmpslots(obj) == -1)
1653 return -1;
1654
1655
1656 /*
1657 * Set up the magic number and version in the Obj_Entry. These
1658 * were checked in the crt1.o from the original ElfKit, so we
1659 * set them for backward compatibility.
1660 */
1661 obj->magic = RTLD_MAGIC;
1662 obj->version = RTLD_VERSION;
1663
1664 /* Set the special PLT or GOT entries. */
1665 init_pltgot(obj);
1666 }
1667
1668 return 0;
1669}
1670
1671/*
1672 * Cleanup procedure. It will be called (by the atexit mechanism) just
1673 * before the process exits.
1674 */
1675static void
1676rtld_exit(void)
1677{
1678 Obj_Entry *obj;
1679
1680 dbg("rtld_exit()");
1681 /* Clear all the reference counts so the fini functions will be called. */
1682 for (obj = obj_list; obj != NULL; obj = obj->next)
1683 obj->refcount = 0;
1684 objlist_call_fini(&list_fini);
1685 /* No need to remove the items from the list, since we are exiting. */
1686}
1687
1688static void *
1689path_enumerate(const char *path, path_enum_proc callback, void *arg)
1690{
1691 if (path == NULL)
1692 return (NULL);
1693
1694 path += strspn(path, ":;");
1695 while (*path != '\0') {
1696 size_t len;
1697 char *res;
1698
1699 len = strcspn(path, ":;");
1700 res = callback(path, len, arg);
1701
1702 if (res != NULL)
1703 return (res);
1704
1705 path += len;
1706 path += strspn(path, ":;");
1707 }
1708
1709 return (NULL);
1710}
1711
1712struct try_library_args {
1713 const char *name;
1714 size_t namelen;
1715 char *buffer;
1716 size_t buflen;
1717};
1718
1719static void *
1720try_library_path(const char *dir, size_t dirlen, void *param)
1721{
1722 struct try_library_args *arg;
1723
1724 arg = param;
1725 if (*dir == '/' || trust) {
1726 char *pathname;
1727
1728 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
1729 return (NULL);
1730
1731 pathname = arg->buffer;
1732 strncpy(pathname, dir, dirlen);
1733 pathname[dirlen] = '/';
1734 strcpy(pathname + dirlen + 1, arg->name);
1735
1736 dbg(" Trying \"%s\"", pathname);
1737 if (access(pathname, F_OK) == 0) { /* We found it */
1738 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
1739 strcpy(pathname, arg->buffer);
1740 return (pathname);
1741 }
1742 }
1743 return (NULL);
1744}
1745
1746static char *
1747search_library_path(const char *name, const char *path)
1748{
1749 char *p;
1750 struct try_library_args arg;
1751
1752 if (path == NULL)
1753 return NULL;
1754
1755 arg.name = name;
1756 arg.namelen = strlen(name);
1757 arg.buffer = xmalloc(PATH_MAX);
1758 arg.buflen = PATH_MAX;
1759
1760 p = path_enumerate(path, try_library_path, &arg);
1761
1762 free(arg.buffer);
1763
1764 return (p);
1765}
1766
1767int
1768dlclose(void *handle)
1769{
1770 Obj_Entry *root;
1771
1772 wlock_acquire();
1773 root = dlcheck(handle);
1774 if (root == NULL) {
1775 wlock_release();
1776 return -1;
1777 }
1778
1779 /* Unreference the object and its dependencies. */
1780 root->dl_refcount--;
1781 unref_dag(root);
1782
1783 if (root->refcount == 0) {
1784 /*
1785 * The object is no longer referenced, so we must unload it.
1786 * First, call the fini functions with no locks held.
1787 */
1788 wlock_release();
1789 objlist_call_fini(&list_fini);
1790 wlock_acquire();
1791 objlist_remove_unref(&list_fini);
1792
1793 /* Finish cleaning up the newly-unreferenced objects. */
1794 GDB_STATE(RT_DELETE,&root->linkmap);
1795 unload_object(root);
1796 GDB_STATE(RT_CONSISTENT,NULL);
1797 }
1798 wlock_release();
1799 return 0;
1800}
1801
1802const char *
1803dlerror(void)
1804{
1805 char *msg = error_message;
1806 error_message = NULL;
1807 return msg;
1808}
1809
984263bc
MD
1810void *
1811dlopen(const char *name, int mode)
1812{
1813 Obj_Entry **old_obj_tail;
1814 Obj_Entry *obj;
1815 Objlist initlist;
1816 int result;
1817
1818 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
1819 if (ld_tracing != NULL)
1820 environ = (char **)*get_program_var_addr("environ");
1821
1822 objlist_init(&initlist);
1823
1824 wlock_acquire();
1825 GDB_STATE(RT_ADD,NULL);
1826
1827 old_obj_tail = obj_tail;
1828 obj = NULL;
1829 if (name == NULL) {
1830 obj = obj_main;
1831 obj->refcount++;
1832 } else {
1833 char *path = find_library(name, obj_main);
1834 if (path != NULL)
1835 obj = load_object(path);
1836 }
1837
1838 if (obj) {
1839 obj->dl_refcount++;
8ca15ec8 1840 if ((mode & RTLD_GLOBAL) && objlist_find(&list_global, obj) == NULL)
984263bc
MD
1841 objlist_push_tail(&list_global, obj);
1842 mode &= RTLD_MODEMASK;
1843 if (*old_obj_tail != NULL) { /* We loaded something new. */
1844 assert(*old_obj_tail == obj);
1845
1846 result = load_needed_objects(obj);
1847 if (result != -1 && ld_tracing)
1848 goto trace;
1849
1850 if (result == -1 ||
c3098c28
SS
1851 (init_dag(obj), relocate_objects(obj, mode == RTLD_NOW,
1852 &obj_rtld)) == -1) {
984263bc
MD
1853 obj->dl_refcount--;
1854 unref_dag(obj);
1855 if (obj->refcount == 0)
1856 unload_object(obj);
1857 obj = NULL;
1858 } else {
1859 /* Make list of init functions to call. */
1860 initlist_add_objects(obj, &obj->next, &initlist);
1861 }
1862 } else if (ld_tracing)
1863 goto trace;
1864 }
1865
1866 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
1867
1868 /* Call the init functions with no locks held. */
1869 wlock_release();
1870 objlist_call_init(&initlist);
1871 wlock_acquire();
1872 objlist_clear(&initlist);
1873 wlock_release();
1874 return obj;
1875trace:
1876 trace_loaded_objects(obj);
1877 wlock_release();
1878 exit(0);
1879}
1880
1881void *
1882dlsym(void *handle, const char *name)
1883{
1884 const Obj_Entry *obj;
1885 unsigned long hash;
1886 const Elf_Sym *def;
1887 const Obj_Entry *defobj;
1888
1889 hash = elf_hash(name);
1890 def = NULL;
1891 defobj = NULL;
1892
1893 rlock_acquire();
1894 if (handle == NULL || handle == RTLD_NEXT ||
1895 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
1896 void *retaddr;
1897
1898 retaddr = __builtin_return_address(0); /* __GNUC__ only */
1899 if ((obj = obj_from_addr(retaddr)) == NULL) {
1900 _rtld_error("Cannot determine caller's shared object");
1901 rlock_release();
1902 return NULL;
1903 }
1904 if (handle == NULL) { /* Just the caller's shared object. */
1905 def = symlook_obj(name, hash, obj, true);
1906 defobj = obj;
1907 } else if (handle == RTLD_NEXT || /* Objects after caller's */
1908 handle == RTLD_SELF) { /* ... caller included */
1909 if (handle == RTLD_NEXT)
1910 obj = obj->next;
1911 for (; obj != NULL; obj = obj->next) {
1912 if ((def = symlook_obj(name, hash, obj, true)) != NULL) {
1913 defobj = obj;
1914 break;
1915 }
1916 }
1917 } else {
1918 assert(handle == RTLD_DEFAULT);
1919 def = symlook_default(name, hash, obj, &defobj, true);
1920 }
1921 } else {
fb0c631e
SS
1922 DoneList donelist;
1923
984263bc
MD
1924 if ((obj = dlcheck(handle)) == NULL) {
1925 rlock_release();
1926 return NULL;
1927 }
1928
fb0c631e 1929 donelist_init(&donelist);
984263bc 1930 if (obj->mainprog) {
984263bc 1931 /* Search main program and all libraries loaded by it. */
984263bc
MD
1932 def = symlook_list(name, hash, &list_main, &defobj, true,
1933 &donelist);
1934 } else {
cebaf0af
SS
1935 Needed_Entry fake;
1936
1937 /* Search the given object and its needed objects. */
1938 fake.next = NULL;
1939 fake.obj = (Obj_Entry *)obj;
1940 fake.name = 0;
1941 def = symlook_needed(name, hash, &fake, &defobj, true,
fb0c631e 1942 &donelist);
984263bc
MD
1943 }
1944 }
1945
1946 if (def != NULL) {
1947 rlock_release();
1948 return defobj->relocbase + def->st_value;
1949 }
1950
1951 _rtld_error("Undefined symbol \"%s\"", name);
1952 rlock_release();
1953 return NULL;
1954}
1955
1956int
1957dladdr(const void *addr, Dl_info *info)
1958{
1959 const Obj_Entry *obj;
1960 const Elf_Sym *def;
1961 void *symbol_addr;
1962 unsigned long symoffset;
1963
1964 rlock_acquire();
1965 obj = obj_from_addr(addr);
1966 if (obj == NULL) {
1967 _rtld_error("No shared object contains address");
1968 rlock_release();
1969 return 0;
1970 }
1971 info->dli_fname = obj->path;
1972 info->dli_fbase = obj->mapbase;
1973 info->dli_saddr = (void *)0;
1974 info->dli_sname = NULL;
1975
1976 /*
1977 * Walk the symbol list looking for the symbol whose address is
1978 * closest to the address sent in.
1979 */
1980 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
1981 def = obj->symtab + symoffset;
1982
1983 /*
1984 * For skip the symbol if st_shndx is either SHN_UNDEF or
1985 * SHN_COMMON.
1986 */
1987 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
1988 continue;
1989
1990 /*
1991 * If the symbol is greater than the specified address, or if it
1992 * is further away from addr than the current nearest symbol,
1993 * then reject it.
1994 */
1995 symbol_addr = obj->relocbase + def->st_value;
1996 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
1997 continue;
1998
1999 /* Update our idea of the nearest symbol. */
2000 info->dli_sname = obj->strtab + def->st_name;
2001 info->dli_saddr = symbol_addr;
2002
2003 /* Exact match? */
2004 if (info->dli_saddr == addr)
2005 break;
2006 }
2007 rlock_release();
2008 return 1;
2009}
2010
2011int
2012dlinfo(void *handle, int request, void *p)
2013{
2014 const Obj_Entry *obj;
2015 int error;
2016
2017 rlock_acquire();
2018
2019 if (handle == NULL || handle == RTLD_SELF) {
2020 void *retaddr;
2021
2022 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2023 if ((obj = obj_from_addr(retaddr)) == NULL)
2024 _rtld_error("Cannot determine caller's shared object");
2025 } else
2026 obj = dlcheck(handle);
2027
2028 if (obj == NULL) {
2029 rlock_release();
2030 return (-1);
2031 }
2032
2033 error = 0;
2034 switch (request) {
2035 case RTLD_DI_LINKMAP:
2036 *((struct link_map const **)p) = &obj->linkmap;
2037 break;
2038 case RTLD_DI_ORIGIN:
2039 error = rtld_dirname(obj->path, p);
2040 break;
2041
2042 case RTLD_DI_SERINFOSIZE:
2043 case RTLD_DI_SERINFO:
2044 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2045 break;
2046
2047 default:
2048 _rtld_error("Invalid request %d passed to dlinfo()", request);
2049 error = -1;
2050 }
2051
2052 rlock_release();
2053
2054 return (error);
2055}
2056
2057struct fill_search_info_args {
2058 int request;
2059 unsigned int flags;
2060 Dl_serinfo *serinfo;
2061 Dl_serpath *serpath;
2062 char *strspace;
2063};
2064
2065static void *
2066fill_search_info(const char *dir, size_t dirlen, void *param)
2067{
2068 struct fill_search_info_args *arg;
2069
2070 arg = param;
2071
2072 if (arg->request == RTLD_DI_SERINFOSIZE) {
2073 arg->serinfo->dls_cnt ++;
2074 arg->serinfo->dls_size += dirlen + 1;
2075 } else {
2076 struct dl_serpath *s_entry;
2077
2078 s_entry = arg->serpath;
2079 s_entry->dls_name = arg->strspace;
2080 s_entry->dls_flags = arg->flags;
2081
2082 strncpy(arg->strspace, dir, dirlen);
2083 arg->strspace[dirlen] = '\0';
2084
2085 arg->strspace += dirlen + 1;
2086 arg->serpath++;
2087 }
2088
2089 return (NULL);
2090}
2091
2092static int
2093do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2094{
2095 struct dl_serinfo _info;
2096 struct fill_search_info_args args;
2097
2098 args.request = RTLD_DI_SERINFOSIZE;
2099 args.serinfo = &_info;
2100
2101 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2102 _info.dls_cnt = 0;
2103
2104 path_enumerate(ld_library_path, fill_search_info, &args);
2105 path_enumerate(obj->rpath, fill_search_info, &args);
2106 path_enumerate(gethints(), fill_search_info, &args);
2107 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2108
2109
2110 if (request == RTLD_DI_SERINFOSIZE) {
2111 info->dls_size = _info.dls_size;
2112 info->dls_cnt = _info.dls_cnt;
2113 return (0);
2114 }
2115
2116 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2117 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2118 return (-1);
2119 }
2120
2121 args.request = RTLD_DI_SERINFO;
2122 args.serinfo = info;
2123 args.serpath = &info->dls_serpath[0];
2124 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2125
2126 args.flags = LA_SER_LIBPATH;
2127 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2128 return (-1);
2129
2130 args.flags = LA_SER_RUNPATH;
2131 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2132 return (-1);
2133
2134 args.flags = LA_SER_CONFIG;
2135 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2136 return (-1);
2137
2138 args.flags = LA_SER_DEFAULT;
2139 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2140 return (-1);
2141 return (0);
2142}
2143
2144static int
2145rtld_dirname(const char *path, char *bname)
2146{
2147 const char *endp;
2148
2149 /* Empty or NULL string gets treated as "." */
2150 if (path == NULL || *path == '\0') {
2151 bname[0] = '.';
2152 bname[1] = '\0';
2153 return (0);
2154 }
2155
2156 /* Strip trailing slashes */
2157 endp = path + strlen(path) - 1;
2158 while (endp > path && *endp == '/')
2159 endp--;
2160
2161 /* Find the start of the dir */
2162 while (endp > path && *endp != '/')
2163 endp--;
2164
2165 /* Either the dir is "/" or there are no slashes */
2166 if (endp == path) {
2167 bname[0] = *endp == '/' ? '/' : '.';
2168 bname[1] = '\0';
2169 return (0);
2170 } else {
2171 do {
2172 endp--;
2173 } while (endp > path && *endp == '/');
2174 }
2175
2176 if (endp - path + 2 > PATH_MAX)
2177 {
2178 _rtld_error("Filename is too long: %s", path);
2179 return(-1);
2180 }
2181
2182 strncpy(bname, path, endp - path + 1);
2183 bname[endp - path + 1] = '\0';
2184 return (0);
2185}
2186
2187static void
2188linkmap_add(Obj_Entry *obj)
2189{
2190 struct link_map *l = &obj->linkmap;
2191 struct link_map *prev;
2192
2193 obj->linkmap.l_name = obj->path;
2194 obj->linkmap.l_addr = obj->mapbase;
2195 obj->linkmap.l_ld = obj->dynamic;
2196#ifdef __mips__
2197 /* GDB needs load offset on MIPS to use the symbols */
2198 obj->linkmap.l_offs = obj->relocbase;
2199#endif
2200
2201 if (r_debug.r_map == NULL) {
2202 r_debug.r_map = l;
2203 return;
2204 }
2205
2206 /*
2207 * Scan to the end of the list, but not past the entry for the
2208 * dynamic linker, which we want to keep at the very end.
2209 */
2210 for (prev = r_debug.r_map;
2211 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2212 prev = prev->l_next)
2213 ;
2214
2215 /* Link in the new entry. */
2216 l->l_prev = prev;
2217 l->l_next = prev->l_next;
2218 if (l->l_next != NULL)
2219 l->l_next->l_prev = l;
2220 prev->l_next = l;
2221}
2222
2223static void
2224linkmap_delete(Obj_Entry *obj)
2225{
2226 struct link_map *l = &obj->linkmap;
2227
2228 if (l->l_prev == NULL) {
2229 if ((r_debug.r_map = l->l_next) != NULL)
2230 l->l_next->l_prev = NULL;
2231 return;
2232 }
2233
2234 if ((l->l_prev->l_next = l->l_next) != NULL)
2235 l->l_next->l_prev = l->l_prev;
2236}
2237
2238/*
2239 * Function for the debugger to set a breakpoint on to gain control.
2240 *
2241 * The two parameters allow the debugger to easily find and determine
2242 * what the runtime loader is doing and to whom it is doing it.
2243 *
2244 * When the loadhook trap is hit (r_debug_state, set at program
2245 * initialization), the arguments can be found on the stack:
2246 *
2247 * +8 struct link_map *m
2248 * +4 struct r_debug *rd
2249 * +0 RetAddr
2250 */
2251void
2252r_debug_state(struct r_debug* rd, struct link_map *m)
2253{
2254}
2255
2256/*
2257 * Get address of the pointer variable in the main program.
2258 */
2259static const void **
2260get_program_var_addr(const char *name)
2261{
2262 const Obj_Entry *obj;
2263 unsigned long hash;
2264
2265 hash = elf_hash(name);
2266 for (obj = obj_main; obj != NULL; obj = obj->next) {
2267 const Elf_Sym *def;
2268
2269 if ((def = symlook_obj(name, hash, obj, false)) != NULL) {
2270 const void **addr;
2271
2272 addr = (const void **)(obj->relocbase + def->st_value);
2273 return addr;
2274 }
2275 }
2276 return NULL;
2277}
2278
2279/*
2280 * Set a pointer variable in the main program to the given value. This
2281 * is used to set key variables such as "environ" before any of the
2282 * init functions are called.
2283 */
2284static void
2285set_program_var(const char *name, const void *value)
2286{
2287 const void **addr;
2288
2289 if ((addr = get_program_var_addr(name)) != NULL) {
2290 dbg("\"%s\": *%p <-- %p", name, addr, value);
2291 *addr = value;
2292 }
2293}
2294
8ca15ec8
MD
2295/*
2296 * This is a special version of getenv which is far more efficient
2297 * at finding LD_ environment vars.
2298 */
2299static
2300const char *
2301_getenv_ld(const char *id)
2302{
2303 const char *envp;
2304 int i, j;
2305 int idlen = strlen(id);
2306
2307 if (ld_index == LD_ARY_CACHE)
2308 return(getenv(id));
2309 if (ld_index == 0) {
2310 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) {
2311 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_')
2312 ld_ary[j++] = envp;
2313 }
2314 if (j == 0)
2315 ld_ary[j++] = "";
2316 ld_index = j;
2317 }
2318 for (i = ld_index - 1; i >= 0; --i) {
2319 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=')
2320 return(ld_ary[i] + idlen + 1);
2321 }
2322 return(NULL);
2323}
2324
984263bc
MD
2325/*
2326 * Given a symbol name in a referencing object, find the corresponding
2327 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2328 * no definition was found. Returns a pointer to the Obj_Entry of the
2329 * defining object via the reference parameter DEFOBJ_OUT.
2330 */
2331static const Elf_Sym *
2332symlook_default(const char *name, unsigned long hash,
2333 const Obj_Entry *refobj, const Obj_Entry **defobj_out, bool in_plt)
2334{
2335 DoneList donelist;
2336 const Elf_Sym *def;
2337 const Elf_Sym *symp;
2338 const Obj_Entry *obj;
2339 const Obj_Entry *defobj;
2340 const Objlist_Entry *elm;
2341 def = NULL;
2342 defobj = NULL;
2343 donelist_init(&donelist);
2344
2345 /* Look first in the referencing object if linked symbolically. */
2346 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
2347 symp = symlook_obj(name, hash, refobj, in_plt);
2348 if (symp != NULL) {
2349 def = symp;
2350 defobj = refobj;
2351 }
2352 }
2353
2354 /* Search all objects loaded at program start up. */
2355 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2356 symp = symlook_list(name, hash, &list_main, &obj, in_plt, &donelist);
2357 if (symp != NULL &&
2358 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2359 def = symp;
2360 defobj = obj;
2361 }
2362 }
2363
2364 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2365 STAILQ_FOREACH(elm, &list_global, link) {
2366 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2367 break;
2368 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2369 &donelist);
2370 if (symp != NULL &&
2371 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2372 def = symp;
2373 defobj = obj;
2374 }
2375 }
2376
2377 /* Search all dlopened DAGs containing the referencing object. */
2378 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2379 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2380 break;
2381 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2382 &donelist);
2383 if (symp != NULL &&
2384 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2385 def = symp;
2386 defobj = obj;
2387 }
2388 }
2389
2390 /*
2391 * Search the dynamic linker itself, and possibly resolve the
2392 * symbol from there. This is how the application links to
2393 * dynamic linker services such as dlopen. Only the values listed
2394 * in the "exports" array can be resolved from the dynamic linker.
2395 */
2396 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2397 symp = symlook_obj(name, hash, &obj_rtld, in_plt);
2398 if (symp != NULL && is_exported(symp)) {
2399 def = symp;
2400 defobj = &obj_rtld;
2401 }
2402 }
2403
2404 if (def != NULL)
2405 *defobj_out = defobj;
2406 return def;
2407}
2408
2409static const Elf_Sym *
fb0c631e 2410symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
984263bc
MD
2411 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2412{
2413 const Elf_Sym *symp;
2414 const Elf_Sym *def;
2415 const Obj_Entry *defobj;
2416 const Objlist_Entry *elm;
2417
2418 def = NULL;
2419 defobj = NULL;
2420 STAILQ_FOREACH(elm, objlist, link) {
2421 if (donelist_check(dlp, elm->obj))
2422 continue;
2423 if ((symp = symlook_obj(name, hash, elm->obj, in_plt)) != NULL) {
2424 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2425 def = symp;
2426 defobj = elm->obj;
2427 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2428 break;
2429 }
2430 }
2431 }
2432 if (def != NULL)
2433 *defobj_out = defobj;
2434 return def;
2435}
2436
cebaf0af
SS
2437/*
2438 * Search the symbol table of a shared object and all objects needed
2439 * by it for a symbol of the given name. Search order is
2440 * breadth-first. Returns a pointer to the symbol, or NULL if no
2441 * definition was found.
2442 */
2443static const Elf_Sym *
2444symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
2445 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2446{
2447 const Elf_Sym *def, *def_w;
2448 const Needed_Entry *n;
2449 const Obj_Entry *obj, *defobj, *defobj1;
2450
2451 def = def_w = NULL;
2452 defobj = NULL;
2453 for (n = needed; n != NULL; n = n->next) {
2454 if ((obj = n->obj) == NULL ||
2455 donelist_check(dlp, obj) ||
2456 (def = symlook_obj(name, hash, obj, in_plt)) == NULL)
2457 continue;
2458 defobj = obj;
2459 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2460 *defobj_out = defobj;
2461 return (def);
2462 }
2463 }
2464 /*
2465 * There we come when either symbol definition is not found in
2466 * directly needed objects, or found symbol is weak.
2467 */
2468 for (n = needed; n != NULL; n = n->next) {
2469 if ((obj = n->obj) == NULL)
2470 continue;
2471 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
2472 in_plt, dlp);
2473 if (def_w == NULL)
2474 continue;
2475 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
2476 def = def_w;
2477 defobj = defobj1;
2478 }
2479 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
2480 break;
2481 }
2482 if (def != NULL)
2483 *defobj_out = defobj;
2484 return def;
2485}
2486
984263bc
MD
2487/*
2488 * Search the symbol table of a single shared object for a symbol of
2489 * the given name. Returns a pointer to the symbol, or NULL if no
2490 * definition was found.
2491 *
2492 * The symbol's hash value is passed in for efficiency reasons; that
2493 * eliminates many recomputations of the hash value.
2494 */
2495const Elf_Sym *
2496symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
2497 bool in_plt)
2498{
2499 if (obj->buckets != NULL) {
2500 unsigned long symnum = obj->buckets[hash % obj->nbuckets];
2501
2502 while (symnum != STN_UNDEF) {
2503 const Elf_Sym *symp;
2504 const char *strp;
2505
2506 if (symnum >= obj->nchains)
2507 return NULL; /* Bad object */
2508 symp = obj->symtab + symnum;
2509 strp = obj->strtab + symp->st_name;
2510
2511 if (name[0] == strp[0] && strcmp(name, strp) == 0)
2512 return symp->st_shndx != SHN_UNDEF ||
2513 (!in_plt && symp->st_value != 0 &&
2514 ELF_ST_TYPE(symp->st_info) == STT_FUNC) ? symp : NULL;
2515
2516 symnum = obj->chains[symnum];
2517 }
2518 }
2519 return NULL;
2520}
2521
2522static void
2523trace_loaded_objects(Obj_Entry *obj)
2524{
8ca15ec8 2525 const char *fmt1, *fmt2, *fmt, *main_local;
984263bc
MD
2526 int c;
2527
8ca15ec8 2528 if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
984263bc
MD
2529 main_local = "";
2530
8ca15ec8 2531 if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL)
984263bc
MD
2532 fmt1 = "\t%o => %p (%x)\n";
2533
8ca15ec8 2534 if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
984263bc
MD
2535 fmt2 = "\t%o (%x)\n";
2536
2537 for (; obj; obj = obj->next) {
2538 Needed_Entry *needed;
2539 char *name, *path;
2540 bool is_lib;
2541
2542 for (needed = obj->needed; needed; needed = needed->next) {
2543 if (needed->obj != NULL) {
2544 if (needed->obj->traced)
2545 continue;
2546 needed->obj->traced = true;
2547 path = needed->obj->path;
2548 } else
2549 path = "not found";
2550
2551 name = (char *)obj->strtab + needed->name;
2552 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
2553
2554 fmt = is_lib ? fmt1 : fmt2;
2555 while ((c = *fmt++) != '\0') {
2556 switch (c) {
2557 default:
2558 putchar(c);
2559 continue;
2560 case '\\':
2561 switch (c = *fmt) {
2562 case '\0':
2563 continue;
2564 case 'n':
2565 putchar('\n');
2566 break;
2567 case 't':
2568 putchar('\t');
2569 break;
2570 }
2571 break;
2572 case '%':
2573 switch (c = *fmt) {
2574 case '\0':
2575 continue;
2576 case '%':
2577 default:
2578 putchar(c);
2579 break;
2580 case 'A':
2581 printf("%s", main_local);
2582 break;
2583 case 'a':
2584 printf("%s", obj_main->path);
2585 break;
2586 case 'o':
2587 printf("%s", name);
2588 break;
2589#if 0
2590 case 'm':
2591 printf("%d", sodp->sod_major);
2592 break;
2593 case 'n':
2594 printf("%d", sodp->sod_minor);
2595 break;
2596#endif
2597 case 'p':
2598 printf("%s", path);
2599 break;
2600 case 'x':
2601 printf("%p", needed->obj ? needed->obj->mapbase : 0);
2602 break;
2603 }
2604 break;
2605 }
2606 ++fmt;
2607 }
2608 }
2609 }
2610}
2611
2612/*
2613 * Unload a dlopened object and its dependencies from memory and from
2614 * our data structures. It is assumed that the DAG rooted in the
2615 * object has already been unreferenced, and that the object has a
2616 * reference count of 0.
2617 */
2618static void
2619unload_object(Obj_Entry *root)
2620{
2621 Obj_Entry *obj;
2622 Obj_Entry **linkp;
2623
2624 assert(root->refcount == 0);
2625
2626 /*
2627 * Pass over the DAG removing unreferenced objects from
2628 * appropriate lists.
2629 */
2630 unlink_object(root);
2631
2632 /* Unmap all objects that are no longer referenced. */
2633 linkp = &obj_list->next;
2634 while ((obj = *linkp) != NULL) {
2635 if (obj->refcount == 0) {
2636 dbg("unloading \"%s\"", obj->path);
2637 munmap(obj->mapbase, obj->mapsize);
2638 linkmap_delete(obj);
2639 *linkp = obj->next;
2640 obj_count--;
2641 obj_free(obj);
2642 } else
2643 linkp = &obj->next;
2644 }
2645 obj_tail = linkp;
2646}
2647
2648static void
2649unlink_object(Obj_Entry *root)
2650{
2651 const Needed_Entry *needed;
2652 Objlist_Entry *elm;
2653
2654 if (root->refcount == 0) {
2655 /* Remove the object from the RTLD_GLOBAL list. */
2656 objlist_remove(&list_global, root);
2657
2658 /* Remove the object from all objects' DAG lists. */
2659 STAILQ_FOREACH(elm, &root->dagmembers , link)
2660 objlist_remove(&elm->obj->dldags, root);
2661 }
2662
2663 for (needed = root->needed; needed != NULL; needed = needed->next)
2664 if (needed->obj != NULL)
2665 unlink_object(needed->obj);
2666}
2667
2668static void
2669unref_dag(Obj_Entry *root)
2670{
2671 const Needed_Entry *needed;
2672
2673 if (root->refcount == 0)
2674 return;
2675 root->refcount--;
2676 if (root->refcount == 0)
2677 for (needed = root->needed; needed != NULL; needed = needed->next)
2678 if (needed->obj != NULL)
2679 unref_dag(needed->obj);
2680}
55b88cae
DX
2681
2682/*
2683 * Common code for MD __tls_get_addr().
2684 */
2685void *
bc633d63 2686tls_get_addr_common(void **dtvp, int index, size_t offset)
55b88cae
DX
2687{
2688 Elf_Addr* dtv = *dtvp;
2689
2690 /* Check dtv generation in case new modules have arrived */
2691 if (dtv[0] != tls_dtv_generation) {
2692 Elf_Addr* newdtv;
2693 int to_copy;
2694
2695 wlock_acquire();
2696
2697 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
2698 to_copy = dtv[1];
2699 if (to_copy > tls_max_index)
2700 to_copy = tls_max_index;
2701 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
2702 newdtv[0] = tls_dtv_generation;
2703 newdtv[1] = tls_max_index;
2704 free(dtv);
bc633d63 2705 *dtvp = newdtv;
55b88cae
DX
2706
2707 wlock_release();
55b88cae
DX
2708 }
2709
2710 /* Dynamically allocate module TLS if necessary */
2711 if (!dtv[index + 1]) {
2712 /* XXX
2713 * here we should avoid to be re-entered by signal handler
2714 * code, I assume wlock_acquire will masked all signals,
2715 * otherwise there is race and dead lock thread itself.
2716 */
2717 wlock_acquire();
2718 if (!dtv[index + 1])
2719 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
2720 wlock_release();
2721 }
2722
2723 return (void*) (dtv[index + 1] + offset);
2724}
2725
9e2ee207 2726#if defined(RTLD_STATIC_TLS_VARIANT_II)
55b88cae
DX
2727
2728/*
bc633d63
MD
2729 * Allocate the static TLS area. Return a pointer to the TCB. The
2730 * static area is based on negative offsets relative to the tcb.
a1eee96a
MD
2731 *
2732 * The TCB contains an errno pointer for the system call layer, but because
2733 * we are the RTLD we really have no idea how the caller was compiled so
2734 * the information has to be passed in. errno can either be:
2735 *
2736 * type 0 errno is a simple non-TLS global pointer.
2737 * (special case for e.g. libc_rtld)
2738 * type 1 errno accessed by GOT entry (dynamically linked programs)
2739 * type 2 errno accessed by %gs:OFFSET (statically linked programs)
55b88cae 2740 */
bc633d63 2741struct tls_tcb *
a1eee96a 2742allocate_tls(Obj_Entry *objs)
55b88cae
DX
2743{
2744 Obj_Entry *obj;
bc633d63 2745 size_t data_size;
bc633d63
MD
2746 size_t dtv_size;
2747 struct tls_tcb *tcb;
a1eee96a 2748 Elf_Addr *dtv;
bc633d63 2749 Elf_Addr addr;
55b88cae 2750
bc633d63
MD
2751 /*
2752 * Allocate the new TCB. static TLS storage is placed just before the
2753 * TCB to support the %gs:OFFSET (negative offset) model.
2754 */
bc633d63
MD
2755 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
2756 ~RTLD_STATIC_TLS_ALIGN_MASK;
f20fd431 2757 tcb = malloc(data_size + sizeof(*tcb));
bc633d63 2758 tcb = (void *)((char *)tcb + data_size); /* actual tcb location */
55b88cae 2759
bc633d63
MD
2760 dtv_size = (tls_max_index + 2) * sizeof(Elf_Addr);
2761 dtv = malloc(dtv_size);
2762 bzero(dtv, dtv_size);
55b88cae 2763
9e2ee207
JS
2764#ifdef RTLD_TCB_HAS_SELF_POINTER
2765 tcb->tcb_self = tcb;
2766#endif
2767 tcb->tcb_dtv = dtv;
2768 tcb->tcb_pthread = NULL;
55b88cae
DX
2769
2770 dtv[0] = tls_dtv_generation;
2771 dtv[1] = tls_max_index;
2772
a1eee96a
MD
2773 for (obj = objs; obj; obj = obj->next) {
2774 if (obj->tlsoffset) {
2775 addr = (Elf_Addr)tcb - obj->tlsoffset;
2776 memset((void *)(addr + obj->tlsinitsize),
2777 0, obj->tlssize - obj->tlsinitsize);
2778 if (obj->tlsinit)
2779 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
2780 dtv[obj->tlsindex + 1] = addr;
55b88cae
DX
2781 }
2782 }
bc633d63 2783 return(tcb);
55b88cae
DX
2784}
2785
2786void
f20fd431 2787free_tls(struct tls_tcb *tcb)
bc633d63
MD
2788{
2789 Elf_Addr *dtv;
2790 int dtv_size, i;
2791 Elf_Addr tls_start, tls_end;
2792 size_t data_size;
2793
2794 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
2795 ~RTLD_STATIC_TLS_ALIGN_MASK;
9e2ee207 2796 dtv = tcb->tcb_dtv;
bc633d63
MD
2797 dtv_size = dtv[1];
2798 tls_end = (Elf_Addr)tcb;
2799 tls_start = (Elf_Addr)tcb - data_size;
2800 for (i = 0; i < dtv_size; i++) {
eecd52b2 2801 if (dtv[i+2] != 0 && (dtv[i+2] < tls_start || dtv[i+2] > tls_end)) {
bc633d63 2802 free((void *)dtv[i+2]);
55b88cae
DX
2803 }
2804 }
bc633d63 2805 free((void *)tls_start);
55b88cae
DX
2806}
2807
9e2ee207
JS
2808#else
2809#error "Unsupported TLS layout"
55b88cae
DX
2810#endif
2811
2812/*
2813 * Allocate TLS block for module with given index.
2814 */
2815void *
2816allocate_module_tls(int index)
2817{
2818 Obj_Entry* obj;
2819 char* p;
2820
2821 for (obj = obj_list; obj; obj = obj->next) {
2822 if (obj->tlsindex == index)
2823 break;
2824 }
2825 if (!obj) {
2826 _rtld_error("Can't find module with TLS index %d", index);
2827 die();
2828 }
2829
2830 p = malloc(obj->tlssize);
2831 memcpy(p, obj->tlsinit, obj->tlsinitsize);
2832 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
2833
2834 return p;
2835}
2836
2837bool
2838allocate_tls_offset(Obj_Entry *obj)
2839{
2840 size_t off;
2841
2842 if (obj->tls_done)
2843 return true;
2844
2845 if (obj->tlssize == 0) {
2846 obj->tls_done = true;
2847 return true;
2848 }
2849
2850 if (obj->tlsindex == 1)
2851 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
2852 else
2853 off = calculate_tls_offset(tls_last_offset, tls_last_size,
2854 obj->tlssize, obj->tlsalign);
2855
2856 /*
2857 * If we have already fixed the size of the static TLS block, we
2858 * must stay within that size. When allocating the static TLS, we
2859 * leave a small amount of space spare to be used for dynamically
2860 * loading modules which use static TLS.
2861 */
2862 if (tls_static_space) {
2863 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
2864 return false;
2865 }
2866
2867 tls_last_offset = obj->tlsoffset = off;
2868 tls_last_size = obj->tlssize;
2869 obj->tls_done = true;
2870
2871 return true;
2872}
2873
2874void
2875free_tls_offset(Obj_Entry *obj)
2876{
9e2ee207 2877#ifdef RTLD_STATIC_TLS_VARIANT_II
55b88cae
DX
2878 /*
2879 * If we were the last thing to allocate out of the static TLS
2880 * block, we give our space back to the 'allocator'. This is a
2881 * simplistic workaround to allow libGL.so.1 to be loaded and
2882 * unloaded multiple times. We only handle the Variant II
2883 * mechanism for now - this really needs a proper allocator.
2884 */
2885 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
2886 == calculate_tls_end(tls_last_offset, tls_last_size)) {
2887 tls_last_offset -= obj->tlssize;
2888 tls_last_size = 0;
2889 }
2890#endif
2891}
2892
bc633d63 2893struct tls_tcb *
a1eee96a 2894_rtld_allocate_tls(void)
55b88cae 2895{
bc633d63 2896 struct tls_tcb *new_tcb;
55b88cae
DX
2897
2898 wlock_acquire();
a1eee96a 2899 new_tcb = allocate_tls(obj_list);
55b88cae
DX
2900 wlock_release();
2901
bc633d63 2902 return (new_tcb);
55b88cae
DX
2903}
2904
2905void
f20fd431 2906_rtld_free_tls(struct tls_tcb *tcb)
55b88cae
DX
2907{
2908 wlock_acquire();
f20fd431 2909 free_tls(tcb);
55b88cae
DX
2910 wlock_release();
2911}
bc633d63 2912