rtld(1), headers, manual pages: Bring in some whitespace, comment etc. fixes.
[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 $
27 */
28
29/*
30 * Dynamic linker for ELF.
31 *
32 * John Polstra <jdp@polstra.com>.
33 */
34
35#ifndef __GNUC__
36#error "GCC is needed to compile this file"
37#endif
38
39#include <sys/param.h>
40#include <sys/mman.h>
41#include <sys/stat.h>
8ca15ec8 42#include <sys/resident.h>
bc633d63 43#include <sys/tls.h>
984263bc 44
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45#include <machine/tls.h>
46
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47#include <dlfcn.h>
48#include <err.h>
49#include <errno.h>
50#include <fcntl.h>
51#include <stdarg.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <unistd.h>
56
57#include "debug.h"
58#include "rtld.h"
59
a1eee96a 60#define PATH_RTLD "/usr/libexec/ld-elf.so.2"
8ca15ec8 61#define LD_ARY_CACHE 16
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62
63/* Types. */
64typedef void (*func_ptr_type)();
65typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
66
67/*
68 * This structure provides a reentrant way to keep a list of objects and
69 * check which ones have already been processed in some way.
70 */
71typedef struct Struct_DoneList {
72 const Obj_Entry **objs; /* Array of object pointers */
73 unsigned int num_alloc; /* Allocated size of the array */
74 unsigned int num_used; /* Number of array slots used */
75} DoneList;
76
77/*
78 * Function declarations.
79 */
984263bc 80static void die(void);
c3098c28 81static void digest_dynamic(Obj_Entry *, int);
8ca15ec8 82static const char *_getenv_ld(const char *id);
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83static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
84static Obj_Entry *dlcheck(void *);
85static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
86static bool donelist_check(DoneList *, const Obj_Entry *);
87static void errmsg_restore(char *);
88static char *errmsg_save(void);
89static void *fill_search_info(const char *, size_t, void *);
90static char *find_library(const char *, const Obj_Entry *);
b6a22d96 91static Obj_Entry *find_object(const char *);
2d6b58a8 92static Obj_Entry *find_object2(const char *, int *, struct stat *);
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93static const char *gethints(void);
94static void init_dag(Obj_Entry *);
95static void init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *);
96static void init_rtld(caddr_t);
97static void initlist_add_neededs(Needed_Entry *needed, Objlist *list);
98static void initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail,
99 Objlist *list);
100static bool is_exported(const Elf_Sym *);
101static void linkmap_add(Obj_Entry *);
102static void linkmap_delete(Obj_Entry *);
103static int load_needed_objects(Obj_Entry *);
104static int load_preload_objects(void);
105static Obj_Entry *load_object(char *);
106static void lock_check(void);
107static Obj_Entry *obj_from_addr(const void *);
108static void objlist_call_fini(Objlist *);
109static void objlist_call_init(Objlist *);
110static void objlist_clear(Objlist *);
111static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
112static void objlist_init(Objlist *);
113static void objlist_push_head(Objlist *, Obj_Entry *);
114static void objlist_push_tail(Objlist *, Obj_Entry *);
115static void objlist_remove(Objlist *, Obj_Entry *);
116static void objlist_remove_unref(Objlist *);
117static void *path_enumerate(const char *, path_enum_proc, void *);
c3098c28 118static int relocate_objects(Obj_Entry *, bool, Obj_Entry *);
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119static int rtld_dirname(const char *, char *);
120static void rtld_exit(void);
121static char *search_library_path(const char *, const char *);
122static const void **get_program_var_addr(const char *name);
123static void set_program_var(const char *, const void *);
124static const Elf_Sym *symlook_default(const char *, unsigned long hash,
125 const Obj_Entry *refobj, const Obj_Entry **defobj_out, bool in_plt);
126static const Elf_Sym *symlook_list(const char *, unsigned long,
fb0c631e 127 const Objlist *, const Obj_Entry **, bool in_plt, DoneList *);
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128static const Elf_Sym *symlook_needed(const char *, unsigned long,
129 const Needed_Entry *, const Obj_Entry **, bool in_plt, DoneList *);
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130static void trace_loaded_objects(Obj_Entry *obj);
131static void unlink_object(Obj_Entry *);
132static void unload_object(Obj_Entry *);
133static void unref_dag(Obj_Entry *);
134
135void r_debug_state(struct r_debug*, struct link_map*);
136
137/*
138 * Data declarations.
139 */
140static char *error_message; /* Message for dlerror(), or NULL */
141struct r_debug r_debug; /* for GDB; */
142static bool trust; /* False for setuid and setgid programs */
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143static const char *ld_bind_now; /* Environment variable for immediate binding */
144static const char *ld_debug; /* Environment variable for debugging */
145static const char *ld_library_path; /* Environment variable for search path */
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146static char *ld_preload; /* Environment variable for libraries to
147 load first */
8ca15ec8 148static const char *ld_tracing; /* Called from ldd(1) to print libs */
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149 /* Optional function call tracing hook */
150static int (*rtld_functrace)(const char *caller_obj,
151 const char *callee_obj,
152 const char *callee_func,
153 void *stack);
154static Obj_Entry *rtld_functrace_obj; /* Object thereof */
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155static Obj_Entry *obj_list; /* Head of linked list of shared objects */
156static Obj_Entry **obj_tail; /* Link field of last object in list */
8ca15ec8 157static Obj_Entry **preload_tail;
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158static Obj_Entry *obj_main; /* The main program shared object */
159static Obj_Entry obj_rtld; /* The dynamic linker shared object */
160static unsigned int obj_count; /* Number of objects in obj_list */
33a8b578 161static int ld_resident; /* Non-zero if resident */
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162static const char *ld_ary[LD_ARY_CACHE];
163static int ld_index;
a1eee96a 164static Objlist initlist;
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165
166static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
167 STAILQ_HEAD_INITIALIZER(list_global);
168static Objlist list_main = /* Objects loaded at program startup */
169 STAILQ_HEAD_INITIALIZER(list_main);
170static Objlist list_fini = /* Objects needing fini() calls */
171 STAILQ_HEAD_INITIALIZER(list_fini);
172
173static LockInfo lockinfo;
174
175static Elf_Sym sym_zero; /* For resolving undefined weak refs. */
176
177#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
178
179extern Elf_Dyn _DYNAMIC;
180#pragma weak _DYNAMIC
181
182/*
183 * These are the functions the dynamic linker exports to application
184 * programs. They are the only symbols the dynamic linker is willing
185 * to export from itself.
186 */
187static func_ptr_type exports[] = {
188 (func_ptr_type) &_rtld_error,
189 (func_ptr_type) &dlclose,
190 (func_ptr_type) &dlerror,
191 (func_ptr_type) &dlopen,
192 (func_ptr_type) &dlsym,
193 (func_ptr_type) &dladdr,
984263bc 194 (func_ptr_type) &dlinfo,
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195#ifdef __i386__
196 (func_ptr_type) &___tls_get_addr,
197#endif
198 (func_ptr_type) &__tls_get_addr,
a1eee96a 199 (func_ptr_type) &__tls_get_addr_tcb,
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200 (func_ptr_type) &_rtld_allocate_tls,
201 (func_ptr_type) &_rtld_free_tls,
a1eee96a 202 (func_ptr_type) &_rtld_call_init,
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203 NULL
204};
205
206/*
207 * Global declarations normally provided by crt1. The dynamic linker is
208 * not built with crt1, so we have to provide them ourselves.
209 */
210char *__progname;
211char **environ;
212
213/*
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214 * Globals to control TLS allocation.
215 */
216size_t tls_last_offset; /* Static TLS offset of last module */
217size_t tls_last_size; /* Static TLS size of last module */
218size_t tls_static_space; /* Static TLS space allocated */
219int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
220int tls_max_index = 1; /* Largest module index allocated */
221
222/*
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223 * Fill in a DoneList with an allocation large enough to hold all of
224 * the currently-loaded objects. Keep this as a macro since it calls
225 * alloca and we want that to occur within the scope of the caller.
226 */
227#define donelist_init(dlp) \
228 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
229 assert((dlp)->objs != NULL), \
230 (dlp)->num_alloc = obj_count, \
231 (dlp)->num_used = 0)
232
233static __inline void
234rlock_acquire(void)
235{
236 lockinfo.rlock_acquire(lockinfo.thelock);
237 atomic_incr_int(&lockinfo.rcount);
238 lock_check();
239}
240
241static __inline void
242wlock_acquire(void)
243{
244 lockinfo.wlock_acquire(lockinfo.thelock);
245 atomic_incr_int(&lockinfo.wcount);
246 lock_check();
247}
248
249static __inline void
250rlock_release(void)
251{
252 atomic_decr_int(&lockinfo.rcount);
253 lockinfo.rlock_release(lockinfo.thelock);
254}
255
256static __inline void
257wlock_release(void)
258{
259 atomic_decr_int(&lockinfo.wcount);
260 lockinfo.wlock_release(lockinfo.thelock);
261}
262
263/*
264 * Main entry point for dynamic linking. The first argument is the
265 * stack pointer. The stack is expected to be laid out as described
266 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
267 * Specifically, the stack pointer points to a word containing
268 * ARGC. Following that in the stack is a null-terminated sequence
269 * of pointers to argument strings. Then comes a null-terminated
270 * sequence of pointers to environment strings. Finally, there is a
271 * sequence of "auxiliary vector" entries.
272 *
273 * The second argument points to a place to store the dynamic linker's
274 * exit procedure pointer and the third to a place to store the main
275 * program's object.
276 *
277 * The return value is the main program's entry point.
278 */
279func_ptr_type
280_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
281{
282 Elf_Auxinfo *aux_info[AT_COUNT];
283 int i;
284 int argc;
285 char **argv;
286 char **env;
287 Elf_Auxinfo *aux;
288 Elf_Auxinfo *auxp;
289 const char *argv0;
55b88cae 290 Objlist_Entry *entry;
984263bc 291 Obj_Entry *obj;
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292
293 /*
294 * On entry, the dynamic linker itself has not been relocated yet.
295 * Be very careful not to reference any global data until after
296 * init_rtld has returned. It is OK to reference file-scope statics
297 * and string constants, and to call static and global functions.
298 */
299
300 /* Find the auxiliary vector on the stack. */
301 argc = *sp++;
302 argv = (char **) sp;
303 sp += argc + 1; /* Skip over arguments and NULL terminator */
304 env = (char **) sp;
984263bc 305
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306 /*
307 * If we aren't already resident we have to dig out some more info.
308 * Note that auxinfo does not exist when we are resident.
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309 *
310 * I'm not sure about the ld_resident check. It seems to read zero
311 * prior to relocation, which is what we want. When running from a
312 * resident copy everything will be relocated so we are definitely
313 * good there.
33a8b578 314 */
5347affc 315 if (ld_resident == 0) {
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MD
316 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
317 ;
318 aux = (Elf_Auxinfo *) sp;
319
320 /* Digest the auxiliary vector. */
321 for (i = 0; i < AT_COUNT; i++)
322 aux_info[i] = NULL;
323 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
324 if (auxp->a_type < AT_COUNT)
325 aux_info[auxp->a_type] = auxp;
326 }
327
328 /* Initialize and relocate ourselves. */
329 assert(aux_info[AT_BASE] != NULL);
330 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
331 }
984263bc 332
5347affc 333 ld_index = 0; /* don't use old env cache in case we are resident */
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MD
334 __progname = obj_rtld.path;
335 argv0 = argv[0] != NULL ? argv[0] : "(null)";
336 environ = env;
337
8ca15ec8 338 trust = (geteuid() == getuid()) && (getegid() == getgid());
984263bc 339
8ca15ec8 340 ld_bind_now = _getenv_ld("LD_BIND_NOW");
984263bc 341 if (trust) {
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MD
342 ld_debug = _getenv_ld("LD_DEBUG");
343 ld_library_path = _getenv_ld("LD_LIBRARY_PATH");
344 ld_preload = (char *)_getenv_ld("LD_PRELOAD");
984263bc 345 }
8ca15ec8 346 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS");
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MD
347
348 if (ld_debug != NULL && *ld_debug != '\0')
349 debug = 1;
350 dbg("%s is initialized, base address = %p", __progname,
351 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
352 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
353 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
354
355 /*
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356 * If we are resident we can skip work that we have already done.
357 * Note that the stack is reset and there is no Elf_Auxinfo
358 * when running from a resident image, and the static globals setup
359 * between here and resident_skip will have already been setup.
360 */
8ca15ec8 361 if (ld_resident)
33a8b578 362 goto resident_skip1;
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363
364 /*
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365 * Load the main program, or process its program header if it is
366 * already loaded.
367 */
368 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
369 int fd = aux_info[AT_EXECFD]->a_un.a_val;
370 dbg("loading main program");
371 obj_main = map_object(fd, argv0, NULL);
372 close(fd);
373 if (obj_main == NULL)
374 die();
375 } else { /* Main program already loaded. */
376 const Elf_Phdr *phdr;
377 int phnum;
378 caddr_t entry;
379
380 dbg("processing main program's program header");
381 assert(aux_info[AT_PHDR] != NULL);
382 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
383 assert(aux_info[AT_PHNUM] != NULL);
384 phnum = aux_info[AT_PHNUM]->a_un.a_val;
385 assert(aux_info[AT_PHENT] != NULL);
386 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
387 assert(aux_info[AT_ENTRY] != NULL);
388 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
389 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
390 die();
391 }
392
393 obj_main->path = xstrdup(argv0);
394 obj_main->mainprog = true;
395
396 /*
397 * Get the actual dynamic linker pathname from the executable if
398 * possible. (It should always be possible.) That ensures that
399 * gdb will find the right dynamic linker even if a non-standard
400 * one is being used.
401 */
402 if (obj_main->interp != NULL &&
403 strcmp(obj_main->interp, obj_rtld.path) != 0) {
404 free(obj_rtld.path);
405 obj_rtld.path = xstrdup(obj_main->interp);
b7b05c9f 406 __progname = obj_rtld.path;
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407 }
408
c3098c28 409 digest_dynamic(obj_main, 0);
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410
411 linkmap_add(obj_main);
412 linkmap_add(&obj_rtld);
413
414 /* Link the main program into the list of objects. */
415 *obj_tail = obj_main;
416 obj_tail = &obj_main->next;
417 obj_count++;
418 obj_main->refcount++;
419 /* Make sure we don't call the main program's init and fini functions. */
420 obj_main->init = obj_main->fini = NULL;
421
422 /* Initialize a fake symbol for resolving undefined weak references. */
423 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
424 sym_zero.st_shndx = SHN_ABS;
425
426 dbg("loading LD_PRELOAD libraries");
427 if (load_preload_objects() == -1)
428 die();
429 preload_tail = obj_tail;
430
431 dbg("loading needed objects");
432 if (load_needed_objects(obj_main) == -1)
433 die();
434
435 /* Make a list of all objects loaded at startup. */
436 for (obj = obj_list; obj != NULL; obj = obj->next)
437 objlist_push_tail(&list_main, obj);
438
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439resident_skip1:
440
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441 if (ld_tracing) { /* We're done */
442 trace_loaded_objects(obj_main);
443 exit(0);
444 }
445
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446 if (ld_resident) /* XXX clean this up! */
447 goto resident_skip2;
448
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449 if (getenv("LD_DUMP_REL_PRE") != NULL) {
450 dump_relocations(obj_main);
451 exit (0);
452 }
453
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454 /* setup TLS for main thread */
455 dbg("initializing initial thread local storage");
456 STAILQ_FOREACH(entry, &list_main, link) {
457 /*
458 * Allocate all the initial objects out of the static TLS
459 * block even if they didn't ask for it.
460 */
461 allocate_tls_offset(entry->obj);
462 }
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463
464 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
465
466 /*
467 * Do not try to allocate the TLS here, let libc do it itself.
468 * (crt1 for the program will call _init_tls())
469 */
55b88cae 470
6192271e 471 if (relocate_objects(obj_main,
c3098c28 472 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
6192271e 473 die();
984263bc 474
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MD
475 dbg("doing copy relocations");
476 if (do_copy_relocations(obj_main) == -1)
477 die();
1c76efe5 478
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479resident_skip2:
480
8ca15ec8 481 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) {
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482 if (exec_sys_unregister(-1) < 0) {
483 dbg("exec_sys_unregister failed %d\n", errno);
484 exit(errno);
485 }
486 dbg("exec_sys_unregister success\n");
487 exit(0);
488 }
984263bc 489
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490 if (getenv("LD_DUMP_REL_POST") != NULL) {
491 dump_relocations(obj_main);
492 exit (0);
493 }
494
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495 dbg("initializing key program variables");
496 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
497 set_program_var("environ", env);
498
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499 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) {
500 extern void resident_start(void);
501 ld_resident = 1;
502 if (exec_sys_register(resident_start) < 0) {
503 dbg("exec_sys_register failed %d\n", errno);
504 exit(errno);
505 }
506 dbg("exec_sys_register success\n");
507 exit(0);
508 }
509
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510 dbg("initializing thread locks");
511 lockdflt_init(&lockinfo);
512 lockinfo.thelock = lockinfo.lock_create(lockinfo.context);
513
514 /* Make a list of init functions to call. */
515 objlist_init(&initlist);
516 initlist_add_objects(obj_list, preload_tail, &initlist);
517
518 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
519
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520 /*
521 * Do NOT call the initlist here, give libc a chance to set up
522 * the initial TLS segment. crt1 will then call _rtld_call_init().
523 */
8ca15ec8 524
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525 dbg("transferring control to program entry point = %p", obj_main->entry);
526
527 /* Return the exit procedure and the program entry point. */
528 *exit_proc = rtld_exit;
529 *objp = obj_main;
530 return (func_ptr_type) obj_main->entry;
531}
532
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533/*
534 * Call the initialization list for dynamically loaded libraries.
535 * (called from crt1.c).
536 */
537void
538_rtld_call_init(void)
539{
540 objlist_call_init(&initlist);
541 wlock_acquire();
542 objlist_clear(&initlist);
543 wlock_release();
544}
545
984263bc 546Elf_Addr
4648abf3 547_rtld_bind(Obj_Entry *obj, Elf_Size reloff, void *stack)
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548{
549 const Elf_Rel *rel;
550 const Elf_Sym *def;
551 const Obj_Entry *defobj;
552 Elf_Addr *where;
553 Elf_Addr target;
38e4b3b6 554 int do_reloc = 1;
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555
556 rlock_acquire();
557 if (obj->pltrel)
558 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
559 else
560 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
561
562 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
563 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
564 if (def == NULL)
565 die();
566
567 target = (Elf_Addr)(defobj->relocbase + def->st_value);
568
569 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
570 defobj->strtab + def->st_name, basename(obj->path),
571 (void *)target, basename(defobj->path));
984263bc 572 rlock_release();
38e4b3b6
SS
573
574 /*
575 * If we have a function call tracing hook, and the
576 * hook would like to keep tracing this one function,
577 * prevent the relocation so we will wind up here
578 * the next time again.
579 *
580 * We don't want to functrace calls from the functracer
581 * to avoid recursive loops.
582 */
583 if (rtld_functrace != NULL && obj != rtld_functrace_obj) {
584 if (rtld_functrace(obj->path,
585 defobj->path,
586 defobj->strtab + def->st_name,
587 stack))
588 do_reloc = 0;
589 }
590
591 if (do_reloc)
592 reloc_jmpslot(where, target);
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593 return target;
594}
595
596/*
597 * Error reporting function. Use it like printf. If formats the message
598 * into a buffer, and sets things up so that the next call to dlerror()
599 * will return the message.
600 */
601void
602_rtld_error(const char *fmt, ...)
603{
604 static char buf[512];
605 va_list ap;
606
607 va_start(ap, fmt);
608 vsnprintf(buf, sizeof buf, fmt, ap);
609 error_message = buf;
610 va_end(ap);
611}
612
613/*
614 * Return a dynamically-allocated copy of the current error message, if any.
615 */
616static char *
617errmsg_save(void)
618{
619 return error_message == NULL ? NULL : xstrdup(error_message);
620}
621
622/*
623 * Restore the current error message from a copy which was previously saved
624 * by errmsg_save(). The copy is freed.
625 */
626static void
627errmsg_restore(char *saved_msg)
628{
629 if (saved_msg == NULL)
630 error_message = NULL;
631 else {
632 _rtld_error("%s", saved_msg);
633 free(saved_msg);
634 }
635}
636
1c76efe5 637const char *
984263bc
MD
638basename(const char *name)
639{
640 const char *p = strrchr(name, '/');
641 return p != NULL ? p + 1 : name;
642}
643
644static void
645die(void)
646{
647 const char *msg = dlerror();
648
649 if (msg == NULL)
650 msg = "Fatal error";
651 errx(1, "%s", msg);
652}
653
654/*
655 * Process a shared object's DYNAMIC section, and save the important
656 * information in its Obj_Entry structure.
657 */
658static void
c3098c28 659digest_dynamic(Obj_Entry *obj, int early)
984263bc
MD
660{
661 const Elf_Dyn *dynp;
662 Needed_Entry **needed_tail = &obj->needed;
663 const Elf_Dyn *dyn_rpath = NULL;
664 int plttype = DT_REL;
665
666 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
667 switch (dynp->d_tag) {
668
669 case DT_REL:
670 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
671 break;
672
673 case DT_RELSZ:
674 obj->relsize = dynp->d_un.d_val;
675 break;
676
677 case DT_RELENT:
678 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
679 break;
680
681 case DT_JMPREL:
682 obj->pltrel = (const Elf_Rel *)
683 (obj->relocbase + dynp->d_un.d_ptr);
684 break;
685
686 case DT_PLTRELSZ:
687 obj->pltrelsize = dynp->d_un.d_val;
688 break;
689
690 case DT_RELA:
691 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
692 break;
693
694 case DT_RELASZ:
695 obj->relasize = dynp->d_un.d_val;
696 break;
697
698 case DT_RELAENT:
699 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
700 break;
701
702 case DT_PLTREL:
703 plttype = dynp->d_un.d_val;
704 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
705 break;
706
707 case DT_SYMTAB:
708 obj->symtab = (const Elf_Sym *)
709 (obj->relocbase + dynp->d_un.d_ptr);
710 break;
711
712 case DT_SYMENT:
713 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
714 break;
715
716 case DT_STRTAB:
717 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
718 break;
719
720 case DT_STRSZ:
721 obj->strsize = dynp->d_un.d_val;
722 break;
723
724 case DT_HASH:
725 {
d697cc44 726 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
984263bc
MD
727 (obj->relocbase + dynp->d_un.d_ptr);
728 obj->nbuckets = hashtab[0];
729 obj->nchains = hashtab[1];
730 obj->buckets = hashtab + 2;
731 obj->chains = obj->buckets + obj->nbuckets;
732 }
733 break;
734
735 case DT_NEEDED:
736 if (!obj->rtld) {
737 Needed_Entry *nep = NEW(Needed_Entry);
738 nep->name = dynp->d_un.d_val;
739 nep->obj = NULL;
740 nep->next = NULL;
741
742 *needed_tail = nep;
743 needed_tail = &nep->next;
744 }
745 break;
746
747 case DT_PLTGOT:
748 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
749 break;
750
751 case DT_TEXTREL:
752 obj->textrel = true;
753 break;
754
755 case DT_SYMBOLIC:
756 obj->symbolic = true;
757 break;
758
759 case DT_RPATH:
167f7029 760 case DT_RUNPATH: /* XXX: process separately */
984263bc
MD
761 /*
762 * We have to wait until later to process this, because we
763 * might not have gotten the address of the string table yet.
764 */
765 dyn_rpath = dynp;
766 break;
767
768 case DT_SONAME:
769 /* Not used by the dynamic linker. */
770 break;
771
772 case DT_INIT:
773 obj->init = (InitFunc) (obj->relocbase + dynp->d_un.d_ptr);
774 break;
775
776 case DT_FINI:
777 obj->fini = (InitFunc) (obj->relocbase + dynp->d_un.d_ptr);
778 break;
779
780 case DT_DEBUG:
781 /* XXX - not implemented yet */
c3098c28
SS
782 if (!early)
783 dbg("Filling in DT_DEBUG entry");
984263bc
MD
784 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
785 break;
786
167f7029
JS
787 case DT_FLAGS:
788 if (dynp->d_un.d_val & DF_ORIGIN) {
789 obj->origin_path = xmalloc(PATH_MAX);
790 if (rtld_dirname(obj->path, obj->origin_path) == -1)
791 die();
792 }
793 if (dynp->d_un.d_val & DF_SYMBOLIC)
794 obj->symbolic = true;
795 if (dynp->d_un.d_val & DF_TEXTREL)
796 obj->textrel = true;
797 if (dynp->d_un.d_val & DF_BIND_NOW)
798 obj->bind_now = true;
799 if (dynp->d_un.d_val & DF_STATIC_TLS)
800 ;
801 break;
802
984263bc 803 default:
c3098c28
SS
804 if (!early)
805 dbg("Ignoring d_tag %d = %#x", dynp->d_tag, dynp->d_tag);
984263bc
MD
806 break;
807 }
808 }
809
810 obj->traced = false;
811
812 if (plttype == DT_RELA) {
813 obj->pltrela = (const Elf_Rela *) obj->pltrel;
814 obj->pltrel = NULL;
815 obj->pltrelasize = obj->pltrelsize;
816 obj->pltrelsize = 0;
817 }
818
819 if (dyn_rpath != NULL)
820 obj->rpath = obj->strtab + dyn_rpath->d_un.d_val;
821}
822
823/*
824 * Process a shared object's program header. This is used only for the
825 * main program, when the kernel has already loaded the main program
826 * into memory before calling the dynamic linker. It creates and
827 * returns an Obj_Entry structure.
828 */
829static Obj_Entry *
830digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
831{
832 Obj_Entry *obj;
833 const Elf_Phdr *phlimit = phdr + phnum;
834 const Elf_Phdr *ph;
835 int nsegs = 0;
836
837 obj = obj_new();
838 for (ph = phdr; ph < phlimit; ph++) {
839 switch (ph->p_type) {
840
841 case PT_PHDR:
842 if ((const Elf_Phdr *)ph->p_vaddr != phdr) {
843 _rtld_error("%s: invalid PT_PHDR", path);
844 return NULL;
845 }
846 obj->phdr = (const Elf_Phdr *) ph->p_vaddr;
847 obj->phsize = ph->p_memsz;
848 break;
849
850 case PT_INTERP:
851 obj->interp = (const char *) ph->p_vaddr;
852 break;
853
854 case PT_LOAD:
855 if (nsegs == 0) { /* First load segment */
856 obj->vaddrbase = trunc_page(ph->p_vaddr);
857 obj->mapbase = (caddr_t) obj->vaddrbase;
858 obj->relocbase = obj->mapbase - obj->vaddrbase;
859 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
860 obj->vaddrbase;
861 } else { /* Last load segment */
862 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
863 obj->vaddrbase;
864 }
865 nsegs++;
866 break;
867
868 case PT_DYNAMIC:
869 obj->dynamic = (const Elf_Dyn *) ph->p_vaddr;
870 break;
55b88cae
DX
871
872 case PT_TLS:
873 obj->tlsindex = 1;
874 obj->tlssize = ph->p_memsz;
875 obj->tlsalign = ph->p_align;
876 obj->tlsinitsize = ph->p_filesz;
877 obj->tlsinit = (void*) ph->p_vaddr;
878 break;
984263bc
MD
879 }
880 }
881 if (nsegs < 1) {
882 _rtld_error("%s: too few PT_LOAD segments", path);
883 return NULL;
884 }
885
886 obj->entry = entry;
887 return obj;
888}
889
890static Obj_Entry *
891dlcheck(void *handle)
892{
893 Obj_Entry *obj;
894
895 for (obj = obj_list; obj != NULL; obj = obj->next)
896 if (obj == (Obj_Entry *) handle)
897 break;
898
899 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
900 _rtld_error("Invalid shared object handle %p", handle);
901 return NULL;
902 }
903 return obj;
904}
905
906/*
907 * If the given object is already in the donelist, return true. Otherwise
908 * add the object to the list and return false.
909 */
910static bool
911donelist_check(DoneList *dlp, const Obj_Entry *obj)
912{
913 unsigned int i;
914
915 for (i = 0; i < dlp->num_used; i++)
916 if (dlp->objs[i] == obj)
917 return true;
918 /*
919 * Our donelist allocation should always be sufficient. But if
920 * our threads locking isn't working properly, more shared objects
921 * could have been loaded since we allocated the list. That should
922 * never happen, but we'll handle it properly just in case it does.
923 */
924 if (dlp->num_used < dlp->num_alloc)
925 dlp->objs[dlp->num_used++] = obj;
926 return false;
927}
928
929/*
930 * Hash function for symbol table lookup. Don't even think about changing
931 * this. It is specified by the System V ABI.
932 */
933unsigned long
934elf_hash(const char *name)
935{
936 const unsigned char *p = (const unsigned char *) name;
937 unsigned long h = 0;
938 unsigned long g;
939
940 while (*p != '\0') {
941 h = (h << 4) + *p++;
942 if ((g = h & 0xf0000000) != 0)
943 h ^= g >> 24;
944 h &= ~g;
945 }
946 return h;
947}
948
949/*
950 * Find the library with the given name, and return its full pathname.
951 * The returned string is dynamically allocated. Generates an error
952 * message and returns NULL if the library cannot be found.
953 *
954 * If the second argument is non-NULL, then it refers to an already-
955 * loaded shared object, whose library search path will be searched.
956 *
957 * The search order is:
984263bc 958 * LD_LIBRARY_PATH
4e390e27 959 * rpath in the referencing file
984263bc
MD
960 * ldconfig hints
961 * /usr/lib
962 */
963static char *
964find_library(const char *name, const Obj_Entry *refobj)
965{
966 char *pathname;
967
968 if (strchr(name, '/') != NULL) { /* Hard coded pathname */
969 if (name[0] != '/' && !trust) {
970 _rtld_error("Absolute pathname required for shared object \"%s\"",
971 name);
972 return NULL;
973 }
974 return xstrdup(name);
975 }
976
977 dbg(" Searching for \"%s\"", name);
978
979 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
980 (refobj != NULL &&
981 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
982 (pathname = search_library_path(name, gethints())) != NULL ||
983 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
984 return pathname;
985
446c0d3a
JS
986 if(refobj != NULL && refobj->path != NULL) {
987 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
988 name, basename(refobj->path));
989 } else {
990 _rtld_error("Shared object \"%s\" not found", name);
991 }
984263bc
MD
992 return NULL;
993}
994
995/*
996 * Given a symbol number in a referencing object, find the corresponding
997 * definition of the symbol. Returns a pointer to the symbol, or NULL if
998 * no definition was found. Returns a pointer to the Obj_Entry of the
999 * defining object via the reference parameter DEFOBJ_OUT.
1000 */
1001const Elf_Sym *
1002find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1003 const Obj_Entry **defobj_out, bool in_plt, SymCache *cache)
1004{
1005 const Elf_Sym *ref;
1006 const Elf_Sym *def;
1007 const Obj_Entry *defobj;
1008 const char *name;
1009 unsigned long hash;
1010
1011 /*
1012 * If we have already found this symbol, get the information from
1013 * the cache.
1014 */
1015 if (symnum >= refobj->nchains)
1016 return NULL; /* Bad object */
1017 if (cache != NULL && cache[symnum].sym != NULL) {
1018 *defobj_out = cache[symnum].obj;
1019 return cache[symnum].sym;
1020 }
1021
1022 ref = refobj->symtab + symnum;
1023 name = refobj->strtab + ref->st_name;
984263bc
MD
1024 defobj = NULL;
1025
0e588128
SS
1026 /*
1027 * We don't have to do a full scale lookup if the symbol is local.
1028 * We know it will bind to the instance in this load module; to
1029 * which we already have a pointer (ie ref). By not doing a lookup,
1030 * we not only improve performance, but it also avoids unresolvable
1031 * symbols when local symbols are not in the hash table.
1032 *
1033 * This might occur for TLS module relocations, which simply use
1034 * symbol 0.
1035 */
1036 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1037 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
c3098c28
SS
1038 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1039 symnum);
1040 }
0e588128
SS
1041 hash = elf_hash(name);
1042 def = symlook_default(name, hash, refobj, &defobj, in_plt);
1043 } else {
c3098c28
SS
1044 def = ref;
1045 defobj = refobj;
0e588128 1046 }
984263bc
MD
1047
1048 /*
1049 * If we found no definition and the reference is weak, treat the
1050 * symbol as having the value zero.
1051 */
1052 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1053 def = &sym_zero;
1054 defobj = obj_main;
1055 }
1056
1057 if (def != NULL) {
1058 *defobj_out = defobj;
1059 /* Record the information in the cache to avoid subsequent lookups. */
1060 if (cache != NULL) {
1061 cache[symnum].sym = def;
1062 cache[symnum].obj = defobj;
1063 }
1064 } else
1065 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1066 return def;
1067}
1068
1069/*
1070 * Return the search path from the ldconfig hints file, reading it if
1071 * necessary. Returns NULL if there are problems with the hints file,
1072 * or if the search path there is empty.
1073 */
1074static const char *
1075gethints(void)
1076{
1077 static char *hints;
1078
1079 if (hints == NULL) {
1080 int fd;
1081 struct elfhints_hdr hdr;
1082 char *p;
1083
1084 /* Keep from trying again in case the hints file is bad. */
1085 hints = "";
1086
1087 if ((fd = open(_PATH_ELF_HINTS, O_RDONLY)) == -1)
1088 return NULL;
1089 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1090 hdr.magic != ELFHINTS_MAGIC ||
1091 hdr.version != 1) {
1092 close(fd);
1093 return NULL;
1094 }
1095 p = xmalloc(hdr.dirlistlen + 1);
1096 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1097 read(fd, p, hdr.dirlistlen + 1) != hdr.dirlistlen + 1) {
1098 free(p);
1099 close(fd);
1100 return NULL;
1101 }
1102 hints = p;
1103 close(fd);
1104 }
1105 return hints[0] != '\0' ? hints : NULL;
1106}
1107
1108static void
1109init_dag(Obj_Entry *root)
1110{
1111 DoneList donelist;
1112
1113 donelist_init(&donelist);
1114 init_dag1(root, root, &donelist);
1115}
1116
1117static void
1118init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1119{
1120 const Needed_Entry *needed;
1121
1122 if (donelist_check(dlp, obj))
1123 return;
1124 objlist_push_tail(&obj->dldags, root);
1125 objlist_push_tail(&root->dagmembers, obj);
1126 for (needed = obj->needed; needed != NULL; needed = needed->next)
1127 if (needed->obj != NULL)
1128 init_dag1(root, needed->obj, dlp);
1129}
1130
1131/*
1132 * Initialize the dynamic linker. The argument is the address at which
1133 * the dynamic linker has been mapped into memory. The primary task of
1134 * this function is to relocate the dynamic linker.
1135 */
1136static void
1137init_rtld(caddr_t mapbase)
1138{
c3098c28
SS
1139 Obj_Entry objtmp; /* Temporary rtld object */
1140
984263bc
MD
1141 /*
1142 * Conjure up an Obj_Entry structure for the dynamic linker.
1143 *
c3098c28
SS
1144 * The "path" member can't be initialized yet because string constatns
1145 * cannot yet be acessed. Below we will set it correctly.
984263bc 1146 */
4648abf3 1147 memset(&objtmp, 0, sizeof(objtmp));
c3098c28
SS
1148 objtmp.path = NULL;
1149 objtmp.rtld = true;
1150 objtmp.mapbase = mapbase;
984263bc 1151#ifdef PIC
c3098c28 1152 objtmp.relocbase = mapbase;
984263bc
MD
1153#endif
1154 if (&_DYNAMIC != 0) {
c3098c28
SS
1155 objtmp.dynamic = rtld_dynamic(&objtmp);
1156 digest_dynamic(&objtmp, 1);
1157 assert(objtmp.needed == NULL);
1158 assert(!objtmp.textrel);
984263bc
MD
1159
1160 /*
1161 * Temporarily put the dynamic linker entry into the object list, so
1162 * that symbols can be found.
1163 */
984263bc 1164
c3098c28 1165 relocate_objects(&objtmp, true, &objtmp);
984263bc
MD
1166 }
1167
c3098c28 1168 /* Initialize the object list. */
984263bc 1169 obj_tail = &obj_list;
c3098c28
SS
1170
1171 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1172 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
984263bc
MD
1173
1174 /* Replace the path with a dynamically allocated copy. */
c3098c28 1175 obj_rtld.path = xstrdup(PATH_RTLD);
984263bc
MD
1176
1177 r_debug.r_brk = r_debug_state;
1178 r_debug.r_state = RT_CONSISTENT;
1179}
1180
1181/*
1182 * Add the init functions from a needed object list (and its recursive
1183 * needed objects) to "list". This is not used directly; it is a helper
1184 * function for initlist_add_objects(). The write lock must be held
1185 * when this function is called.
1186 */
1187static void
1188initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1189{
1190 /* Recursively process the successor needed objects. */
1191 if (needed->next != NULL)
1192 initlist_add_neededs(needed->next, list);
1193
1194 /* Process the current needed object. */
1195 if (needed->obj != NULL)
1196 initlist_add_objects(needed->obj, &needed->obj->next, list);
1197}
1198
1199/*
1200 * Scan all of the DAGs rooted in the range of objects from "obj" to
1201 * "tail" and add their init functions to "list". This recurses over
1202 * the DAGs and ensure the proper init ordering such that each object's
1203 * needed libraries are initialized before the object itself. At the
1204 * same time, this function adds the objects to the global finalization
1205 * list "list_fini" in the opposite order. The write lock must be
1206 * held when this function is called.
1207 */
1208static void
1209initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1210{
1211 if (obj->init_done)
1212 return;
1213 obj->init_done = true;
1214
1215 /* Recursively process the successor objects. */
1216 if (&obj->next != tail)
1217 initlist_add_objects(obj->next, tail, list);
1218
1219 /* Recursively process the needed objects. */
1220 if (obj->needed != NULL)
1221 initlist_add_neededs(obj->needed, list);
1222
1223 /* Add the object to the init list. */
1224 if (obj->init != NULL)
1225 objlist_push_tail(list, obj);
1226
1227 /* Add the object to the global fini list in the reverse order. */
1228 if (obj->fini != NULL)
1229 objlist_push_head(&list_fini, obj);
1230}
1231
1232static bool
1233is_exported(const Elf_Sym *def)
1234{
d697cc44 1235 Elf_Addr value;
984263bc
MD
1236 const func_ptr_type *p;
1237
d697cc44
MD
1238 value = (Elf_Addr)(obj_rtld.relocbase + def->st_value);
1239 for (p = exports; *p != NULL; p++) {
1240 if ((Elf_Addr)(*p) == value)
984263bc 1241 return true;
d697cc44 1242 }
984263bc
MD
1243 return false;
1244}
1245
1246/*
1247 * Given a shared object, traverse its list of needed objects, and load
1248 * each of them. Returns 0 on success. Generates an error message and
1249 * returns -1 on failure.
1250 */
1251static int
1252load_needed_objects(Obj_Entry *first)
1253{
1254 Obj_Entry *obj;
1255
1256 for (obj = first; obj != NULL; obj = obj->next) {
1257 Needed_Entry *needed;
1258
1259 for (needed = obj->needed; needed != NULL; needed = needed->next) {
1260 const char *name = obj->strtab + needed->name;
1261 char *path = find_library(name, obj);
1262
1263 needed->obj = NULL;
1264 if (path == NULL && !ld_tracing)
1265 return -1;
1266
1267 if (path) {
1268 needed->obj = load_object(path);
1269 if (needed->obj == NULL && !ld_tracing)
1270 return -1; /* XXX - cleanup */
1271 }
1272 }
1273 }
1274
1275 return 0;
1276}
1277
38e4b3b6
SS
1278#define RTLD_FUNCTRACE "_rtld_functrace"
1279
984263bc
MD
1280static int
1281load_preload_objects(void)
1282{
1283 char *p = ld_preload;
1284 static const char delim[] = " \t:;";
1285
1286 if (p == NULL)
eecd52b2 1287 return 0;
984263bc
MD
1288
1289 p += strspn(p, delim);
1290 while (*p != '\0') {
1291 size_t len = strcspn(p, delim);
1292 char *path;
1293 char savech;
38e4b3b6
SS
1294 Obj_Entry *obj;
1295 const Elf_Sym *sym;
984263bc
MD
1296
1297 savech = p[len];
1298 p[len] = '\0';
1299 if ((path = find_library(p, NULL)) == NULL)
1300 return -1;
38e4b3b6
SS
1301 obj = load_object(path);
1302 if (obj == NULL)
984263bc
MD
1303 return -1; /* XXX - cleanup */
1304 p[len] = savech;
1305 p += len;
1306 p += strspn(p, delim);
38e4b3b6
SS
1307
1308 /* Check for the magic tracing function */
1309 sym = symlook_obj(RTLD_FUNCTRACE, elf_hash(RTLD_FUNCTRACE), obj, true);
1310 if (sym != NULL) {
1311 rtld_functrace = (void *)(obj->relocbase + sym->st_value);
1312 rtld_functrace_obj = obj;
1313 }
984263bc
MD
1314 }
1315 return 0;
1316}
1317
1318/*
2d6b58a8 1319 * Returns a pointer to the Obj_Entry for the object with the given path.
b6a22d96
JS
1320 * Returns NULL if no matching object was found.
1321 */
1322static Obj_Entry *
1323find_object(const char *path)
1324{
1325 Obj_Entry *obj;
1326
1327 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1328 if (strcmp(obj->path, path) == 0)
1329 return(obj);
1330 }
1331 return(NULL);
1332}
1333
1334/*
2d6b58a8
JS
1335 * Returns a pointer to the Obj_Entry for the object matching device and
1336 * inode of the given path. If no matching object was found, the descriptor
1337 * is returned in fd.
1338 * Returns with obj == NULL && fd == -1 on error.
1339 */
1340static Obj_Entry *
1341find_object2(const char *path, int *fd, struct stat *sb)
1342{
1343 Obj_Entry *obj;
1344
1345 if ((*fd = open(path, O_RDONLY)) == -1) {
1346 _rtld_error("Cannot open \"%s\"", path);
1347 return(NULL);
1348 }
2d6b58a8
JS
1349 if (fstat(*fd, sb) == -1) {
1350 _rtld_error("Cannot fstat \"%s\"", path);
1351 close(*fd);
1352 *fd = -1;
1353 return NULL;
1354 }
2d6b58a8
JS
1355 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1356 if (obj->ino == sb->st_ino && obj->dev == sb->st_dev) {
1357 close(*fd);
1358 break;
1359 }
1360 }
1361
1362 return(obj);
1363}
1364
1365/*
984263bc
MD
1366 * Load a shared object into memory, if it is not already loaded. The
1367 * argument must be a string allocated on the heap. This function assumes
1368 * responsibility for freeing it when necessary.
1369 *
1370 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1371 * on failure.
1372 */
1373static Obj_Entry *
1374load_object(char *path)
1375{
1376 Obj_Entry *obj;
1377 int fd = -1;
1378 struct stat sb;
1379
b6a22d96 1380 obj = find_object(path);
2d6b58a8 1381 if (obj != NULL) {
588c673f 1382 obj->refcount++;
2d6b58a8
JS
1383 free(path);
1384 return(obj);
1385 }
984263bc 1386
2d6b58a8 1387 obj = find_object2(path, &fd, &sb);
588c673f
JS
1388 if (obj != NULL) {
1389 obj->refcount++;
2d6b58a8
JS
1390 free(path);
1391 return(obj);
588c673f
JS
1392 } else if (fd == -1) {
1393 free(path);
1394 return(NULL);
984263bc 1395 }
2d6b58a8
JS
1396 dbg("loading \"%s\"", path);
1397 obj = map_object(fd, path, &sb);
1398 close(fd);
1399 if (obj == NULL) {
1400 free(path);
1401 return NULL;
1402 }
984263bc 1403
2d6b58a8 1404 obj->path = path;
c3098c28 1405 digest_dynamic(obj, 0);
984263bc 1406
2d6b58a8
JS
1407 *obj_tail = obj;
1408 obj_tail = &obj->next;
1409 obj_count++;
1410 linkmap_add(obj); /* for GDB & dlinfo() */
984263bc 1411
139b8f34
SW
1412 dbg(" %p .. %p: %s", obj->mapbase,
1413 obj->mapbase + obj->mapsize - 1, obj->path);
2d6b58a8
JS
1414 if (obj->textrel)
1415 dbg(" WARNING: %s has impure text", obj->path);
984263bc
MD
1416
1417 obj->refcount++;
1418 return obj;
1419}
1420
1421/*
1422 * Check for locking violations and die if one is found.
1423 */
1424static void
1425lock_check(void)
1426{
1427 int rcount, wcount;
1428
1429 rcount = lockinfo.rcount;
1430 wcount = lockinfo.wcount;
1431 assert(rcount >= 0);
1432 assert(wcount >= 0);
1433 if (wcount > 1 || (wcount != 0 && rcount != 0)) {
1434 _rtld_error("Application locking error: %d readers and %d writers"
1435 " in dynamic linker. See DLLOCKINIT(3) in manual pages.",
1436 rcount, wcount);
1437 die();
1438 }
1439}
1440
1441static Obj_Entry *
1442obj_from_addr(const void *addr)
1443{
984263bc
MD
1444 Obj_Entry *obj;
1445
984263bc 1446 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc
MD
1447 if (addr < (void *) obj->mapbase)
1448 continue;
c6873e56 1449 if (addr < (void *) (obj->mapbase + obj->mapsize))
984263bc
MD
1450 return obj;
1451 }
1452 return NULL;
1453}
1454
1455/*
1456 * Call the finalization functions for each of the objects in "list"
1457 * which are unreferenced. All of the objects are expected to have
1458 * non-NULL fini functions.
1459 */
1460static void
1461objlist_call_fini(Objlist *list)
1462{
1463 Objlist_Entry *elm;
1464 char *saved_msg;
1465
1466 /*
1467 * Preserve the current error message since a fini function might
1468 * call into the dynamic linker and overwrite it.
1469 */
1470 saved_msg = errmsg_save();
1471 STAILQ_FOREACH(elm, list, link) {
1472 if (elm->obj->refcount == 0) {
1473 dbg("calling fini function for %s", elm->obj->path);
1474 (*elm->obj->fini)();
1475 }
1476 }
1477 errmsg_restore(saved_msg);
1478}
1479
1480/*
1481 * Call the initialization functions for each of the objects in
1482 * "list". All of the objects are expected to have non-NULL init
1483 * functions.
1484 */
1485static void
1486objlist_call_init(Objlist *list)
1487{
1488 Objlist_Entry *elm;
1489 char *saved_msg;
1490
1491 /*
1492 * Preserve the current error message since an init function might
1493 * call into the dynamic linker and overwrite it.
1494 */
1495 saved_msg = errmsg_save();
1496 STAILQ_FOREACH(elm, list, link) {
1497 dbg("calling init function for %s", elm->obj->path);
1498 (*elm->obj->init)();
1499 }
1500 errmsg_restore(saved_msg);
1501}
1502
1503static void
1504objlist_clear(Objlist *list)
1505{
1506 Objlist_Entry *elm;
1507
1508 while (!STAILQ_EMPTY(list)) {
1509 elm = STAILQ_FIRST(list);
1510 STAILQ_REMOVE_HEAD(list, link);
1511 free(elm);
1512 }
1513}
1514
1515static Objlist_Entry *
1516objlist_find(Objlist *list, const Obj_Entry *obj)
1517{
1518 Objlist_Entry *elm;
1519
1520 STAILQ_FOREACH(elm, list, link)
1521 if (elm->obj == obj)
1522 return elm;
1523 return NULL;
1524}
1525
1526static void
1527objlist_init(Objlist *list)
1528{
1529 STAILQ_INIT(list);
1530}
1531
1532static void
1533objlist_push_head(Objlist *list, Obj_Entry *obj)
1534{
1535 Objlist_Entry *elm;
1536
1537 elm = NEW(Objlist_Entry);
1538 elm->obj = obj;
1539 STAILQ_INSERT_HEAD(list, elm, link);
1540}
1541
1542static void
1543objlist_push_tail(Objlist *list, Obj_Entry *obj)
1544{
1545 Objlist_Entry *elm;
1546
1547 elm = NEW(Objlist_Entry);
1548 elm->obj = obj;
1549 STAILQ_INSERT_TAIL(list, elm, link);
1550}
1551
1552static void
1553objlist_remove(Objlist *list, Obj_Entry *obj)
1554{
1555 Objlist_Entry *elm;
1556
1557 if ((elm = objlist_find(list, obj)) != NULL) {
1558 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1559 free(elm);
1560 }
1561}
1562
1563/*
1564 * Remove all of the unreferenced objects from "list".
1565 */
1566static void
1567objlist_remove_unref(Objlist *list)
1568{
1569 Objlist newlist;
1570 Objlist_Entry *elm;
1571
1572 STAILQ_INIT(&newlist);
1573 while (!STAILQ_EMPTY(list)) {
1574 elm = STAILQ_FIRST(list);
1575 STAILQ_REMOVE_HEAD(list, link);
1576 if (elm->obj->refcount == 0)
1577 free(elm);
1578 else
1579 STAILQ_INSERT_TAIL(&newlist, elm, link);
1580 }
1581 *list = newlist;
1582}
1583
1584/*
1585 * Relocate newly-loaded shared objects. The argument is a pointer to
1586 * the Obj_Entry for the first such object. All objects from the first
1587 * to the end of the list of objects are relocated. Returns 0 on success,
1588 * or -1 on failure.
1589 */
1590static int
c3098c28 1591relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
984263bc
MD
1592{
1593 Obj_Entry *obj;
1594
1595 for (obj = first; obj != NULL; obj = obj->next) {
c3098c28 1596 if (obj != rtldobj)
984263bc
MD
1597 dbg("relocating \"%s\"", obj->path);
1598 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1599 obj->symtab == NULL || obj->strtab == NULL) {
1600 _rtld_error("%s: Shared object has no run-time symbol table",
1601 obj->path);
1602 return -1;
1603 }
1604
1605 if (obj->textrel) {
1606 /* There are relocations to the write-protected text segment. */
1607 if (mprotect(obj->mapbase, obj->textsize,
1608 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1609 _rtld_error("%s: Cannot write-enable text segment: %s",
1610 obj->path, strerror(errno));
1611 return -1;
1612 }
1613 }
1614
1615 /* Process the non-PLT relocations. */
c3098c28 1616 if (reloc_non_plt(obj, rtldobj))
984263bc
MD
1617 return -1;
1618
4b89341e
MD
1619 /*
1620 * Reprotect the text segment. Make sure it is included in the
1621 * core dump since we modified it. This unfortunately causes the
1622 * entire text segment to core-out but we don't have much of a
1623 * choice. We could try to only reenable core dumps on pages
1624 * in which relocations occured but that is likely most of the text
1625 * pages anyway, and even that would not work because the rest of
1626 * the text pages would wind up as a read-only OBJT_DEFAULT object
1627 * (created due to our modifications) backed by the original OBJT_VNODE
1628 * object, and the ELF coredump code is currently only able to dump
1629 * vnode records for pure vnode-backed mappings, not vnode backings
1630 * to memory objects.
1631 */
1632 if (obj->textrel) {
1633 madvise(obj->mapbase, obj->textsize, MADV_CORE);
984263bc
MD
1634 if (mprotect(obj->mapbase, obj->textsize,
1635 PROT_READ|PROT_EXEC) == -1) {
1636 _rtld_error("%s: Cannot write-protect text segment: %s",
1637 obj->path, strerror(errno));
1638 return -1;
1639 }
1640 }
1641
1642 /* Process the PLT relocations. */
1643 if (reloc_plt(obj) == -1)
1644 return -1;
1645 /* Relocate the jump slots if we are doing immediate binding. */
167f7029 1646 if (obj->bind_now || bind_now)
984263bc
MD
1647 if (reloc_jmpslots(obj) == -1)
1648 return -1;
1649
1650
1651 /*
1652 * Set up the magic number and version in the Obj_Entry. These
1653 * were checked in the crt1.o from the original ElfKit, so we
1654 * set them for backward compatibility.
1655 */
1656 obj->magic = RTLD_MAGIC;
1657 obj->version = RTLD_VERSION;
1658
1659 /* Set the special PLT or GOT entries. */
1660 init_pltgot(obj);
1661 }
1662
1663 return 0;
1664}
1665
1666/*
1667 * Cleanup procedure. It will be called (by the atexit mechanism) just
1668 * before the process exits.
1669 */
1670static void
1671rtld_exit(void)
1672{
1673 Obj_Entry *obj;
1674
1675 dbg("rtld_exit()");
1676 /* Clear all the reference counts so the fini functions will be called. */
1677 for (obj = obj_list; obj != NULL; obj = obj->next)
1678 obj->refcount = 0;
1679 objlist_call_fini(&list_fini);
1680 /* No need to remove the items from the list, since we are exiting. */
1681}
1682
1683static void *
1684path_enumerate(const char *path, path_enum_proc callback, void *arg)
1685{
1686 if (path == NULL)
1687 return (NULL);
1688
1689 path += strspn(path, ":;");
1690 while (*path != '\0') {
1691 size_t len;
1692 char *res;
1693
1694 len = strcspn(path, ":;");
1695 res = callback(path, len, arg);
1696
1697 if (res != NULL)
1698 return (res);
1699
1700 path += len;
1701 path += strspn(path, ":;");
1702 }
1703
1704 return (NULL);
1705}
1706
1707struct try_library_args {
1708 const char *name;
1709 size_t namelen;
1710 char *buffer;
1711 size_t buflen;
1712};
1713
1714static void *
1715try_library_path(const char *dir, size_t dirlen, void *param)
1716{
1717 struct try_library_args *arg;
1718
1719 arg = param;
1720 if (*dir == '/' || trust) {
1721 char *pathname;
1722
1723 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
1724 return (NULL);
1725
1726 pathname = arg->buffer;
1727 strncpy(pathname, dir, dirlen);
1728 pathname[dirlen] = '/';
1729 strcpy(pathname + dirlen + 1, arg->name);
1730
1731 dbg(" Trying \"%s\"", pathname);
1732 if (access(pathname, F_OK) == 0) { /* We found it */
1733 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
1734 strcpy(pathname, arg->buffer);
1735 return (pathname);
1736 }
1737 }
1738 return (NULL);
1739}
1740
1741static char *
1742search_library_path(const char *name, const char *path)
1743{
1744 char *p;
1745 struct try_library_args arg;
1746
1747 if (path == NULL)
1748 return NULL;
1749
1750 arg.name = name;
1751 arg.namelen = strlen(name);
1752 arg.buffer = xmalloc(PATH_MAX);
1753 arg.buflen = PATH_MAX;
1754
1755 p = path_enumerate(path, try_library_path, &arg);
1756
1757 free(arg.buffer);
1758
1759 return (p);
1760}
1761
1762int
1763dlclose(void *handle)
1764{
1765 Obj_Entry *root;
1766
1767 wlock_acquire();
1768 root = dlcheck(handle);
1769 if (root == NULL) {
1770 wlock_release();
1771 return -1;
1772 }
1773
1774 /* Unreference the object and its dependencies. */
1775 root->dl_refcount--;
139b8f34 1776
984263bc
MD
1777 unref_dag(root);
1778
1779 if (root->refcount == 0) {
1780 /*
1781 * The object is no longer referenced, so we must unload it.
1782 * First, call the fini functions with no locks held.
1783 */
1784 wlock_release();
1785 objlist_call_fini(&list_fini);
1786 wlock_acquire();
1787 objlist_remove_unref(&list_fini);
1788
1789 /* Finish cleaning up the newly-unreferenced objects. */
1790 GDB_STATE(RT_DELETE,&root->linkmap);
1791 unload_object(root);
1792 GDB_STATE(RT_CONSISTENT,NULL);
1793 }
1794 wlock_release();
1795 return 0;
1796}
1797
1798const char *
1799dlerror(void)
1800{
1801 char *msg = error_message;
1802 error_message = NULL;
1803 return msg;
1804}
1805
984263bc
MD
1806void *
1807dlopen(const char *name, int mode)
1808{
1809 Obj_Entry **old_obj_tail;
1810 Obj_Entry *obj;
1811 Objlist initlist;
1812 int result;
1813
1814 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
1815 if (ld_tracing != NULL)
1816 environ = (char **)*get_program_var_addr("environ");
1817
1818 objlist_init(&initlist);
1819
1820 wlock_acquire();
1821 GDB_STATE(RT_ADD,NULL);
1822
1823 old_obj_tail = obj_tail;
1824 obj = NULL;
1825 if (name == NULL) {
1826 obj = obj_main;
1827 obj->refcount++;
1828 } else {
1829 char *path = find_library(name, obj_main);
1830 if (path != NULL)
1831 obj = load_object(path);
1832 }
1833
1834 if (obj) {
1835 obj->dl_refcount++;
139b8f34 1836 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
984263bc
MD
1837 objlist_push_tail(&list_global, obj);
1838 mode &= RTLD_MODEMASK;
1839 if (*old_obj_tail != NULL) { /* We loaded something new. */
1840 assert(*old_obj_tail == obj);
984263bc
MD
1841 result = load_needed_objects(obj);
1842 if (result != -1 && ld_tracing)
1843 goto trace;
1844
1845 if (result == -1 ||
c3098c28
SS
1846 (init_dag(obj), relocate_objects(obj, mode == RTLD_NOW,
1847 &obj_rtld)) == -1) {
984263bc
MD
1848 obj->dl_refcount--;
1849 unref_dag(obj);
1850 if (obj->refcount == 0)
1851 unload_object(obj);
1852 obj = NULL;
1853 } else {
1854 /* Make list of init functions to call. */
1855 initlist_add_objects(obj, &obj->next, &initlist);
1856 }
1857 } else if (ld_tracing)
1858 goto trace;
1859 }
1860
1861 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
1862
1863 /* Call the init functions with no locks held. */
1864 wlock_release();
1865 objlist_call_init(&initlist);
1866 wlock_acquire();
1867 objlist_clear(&initlist);
1868 wlock_release();
1869 return obj;
1870trace:
1871 trace_loaded_objects(obj);
1872 wlock_release();
1873 exit(0);
1874}
1875
1876void *
1877dlsym(void *handle, const char *name)
1878{
1879 const Obj_Entry *obj;
1880 unsigned long hash;
1881 const Elf_Sym *def;
1882 const Obj_Entry *defobj;
1883
1884 hash = elf_hash(name);
1885 def = NULL;
1886 defobj = NULL;
1887
1888 rlock_acquire();
1889 if (handle == NULL || handle == RTLD_NEXT ||
1890 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
1891 void *retaddr;
1892
1893 retaddr = __builtin_return_address(0); /* __GNUC__ only */
1894 if ((obj = obj_from_addr(retaddr)) == NULL) {
1895 _rtld_error("Cannot determine caller's shared object");
1896 rlock_release();
1897 return NULL;
1898 }
1899 if (handle == NULL) { /* Just the caller's shared object. */
1900 def = symlook_obj(name, hash, obj, true);
1901 defobj = obj;
1902 } else if (handle == RTLD_NEXT || /* Objects after caller's */
1903 handle == RTLD_SELF) { /* ... caller included */
1904 if (handle == RTLD_NEXT)
1905 obj = obj->next;
1906 for (; obj != NULL; obj = obj->next) {
1907 if ((def = symlook_obj(name, hash, obj, true)) != NULL) {
1908 defobj = obj;
1909 break;
1910 }
1911 }
1912 } else {
1913 assert(handle == RTLD_DEFAULT);
1914 def = symlook_default(name, hash, obj, &defobj, true);
1915 }
1916 } else {
fb0c631e
SS
1917 DoneList donelist;
1918
984263bc
MD
1919 if ((obj = dlcheck(handle)) == NULL) {
1920 rlock_release();
1921 return NULL;
1922 }
1923
fb0c631e 1924 donelist_init(&donelist);
984263bc 1925 if (obj->mainprog) {
984263bc 1926 /* Search main program and all libraries loaded by it. */
984263bc
MD
1927 def = symlook_list(name, hash, &list_main, &defobj, true,
1928 &donelist);
1929 } else {
cebaf0af
SS
1930 Needed_Entry fake;
1931
1932 /* Search the given object and its needed objects. */
1933 fake.next = NULL;
1934 fake.obj = (Obj_Entry *)obj;
1935 fake.name = 0;
1936 def = symlook_needed(name, hash, &fake, &defobj, true,
fb0c631e 1937 &donelist);
984263bc
MD
1938 }
1939 }
1940
1941 if (def != NULL) {
1942 rlock_release();
1943 return defobj->relocbase + def->st_value;
1944 }
1945
1946 _rtld_error("Undefined symbol \"%s\"", name);
1947 rlock_release();
1948 return NULL;
1949}
1950
1951int
1952dladdr(const void *addr, Dl_info *info)
1953{
1954 const Obj_Entry *obj;
1955 const Elf_Sym *def;
1956 void *symbol_addr;
1957 unsigned long symoffset;
1958
1959 rlock_acquire();
1960 obj = obj_from_addr(addr);
1961 if (obj == NULL) {
1962 _rtld_error("No shared object contains address");
1963 rlock_release();
1964 return 0;
1965 }
1966 info->dli_fname = obj->path;
1967 info->dli_fbase = obj->mapbase;
60233e58 1968 info->dli_saddr = NULL;
984263bc
MD
1969 info->dli_sname = NULL;
1970
1971 /*
1972 * Walk the symbol list looking for the symbol whose address is
1973 * closest to the address sent in.
1974 */
1975 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
1976 def = obj->symtab + symoffset;
1977
1978 /*
1979 * For skip the symbol if st_shndx is either SHN_UNDEF or
1980 * SHN_COMMON.
1981 */
1982 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
1983 continue;
1984
1985 /*
1986 * If the symbol is greater than the specified address, or if it
1987 * is further away from addr than the current nearest symbol,
1988 * then reject it.
1989 */
1990 symbol_addr = obj->relocbase + def->st_value;
1991 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
1992 continue;
1993
1994 /* Update our idea of the nearest symbol. */
1995 info->dli_sname = obj->strtab + def->st_name;
1996 info->dli_saddr = symbol_addr;
1997
1998 /* Exact match? */
1999 if (info->dli_saddr == addr)
2000 break;
2001 }
2002 rlock_release();
2003 return 1;
2004}
2005
2006int
2007dlinfo(void *handle, int request, void *p)
2008{
2009 const Obj_Entry *obj;
2010 int error;
2011
2012 rlock_acquire();
2013
2014 if (handle == NULL || handle == RTLD_SELF) {
2015 void *retaddr;
2016
2017 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2018 if ((obj = obj_from_addr(retaddr)) == NULL)
2019 _rtld_error("Cannot determine caller's shared object");
2020 } else
2021 obj = dlcheck(handle);
2022
2023 if (obj == NULL) {
2024 rlock_release();
2025 return (-1);
2026 }
2027
2028 error = 0;
2029 switch (request) {
2030 case RTLD_DI_LINKMAP:
2031 *((struct link_map const **)p) = &obj->linkmap;
2032 break;
2033 case RTLD_DI_ORIGIN:
2034 error = rtld_dirname(obj->path, p);
2035 break;
2036
2037 case RTLD_DI_SERINFOSIZE:
2038 case RTLD_DI_SERINFO:
2039 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2040 break;
2041
2042 default:
2043 _rtld_error("Invalid request %d passed to dlinfo()", request);
2044 error = -1;
2045 }
2046
2047 rlock_release();
2048
2049 return (error);
2050}
2051
2052struct fill_search_info_args {
2053 int request;
2054 unsigned int flags;
2055 Dl_serinfo *serinfo;
2056 Dl_serpath *serpath;
2057 char *strspace;
2058};
2059
2060static void *
2061fill_search_info(const char *dir, size_t dirlen, void *param)
2062{
2063 struct fill_search_info_args *arg;
2064
2065 arg = param;
2066
2067 if (arg->request == RTLD_DI_SERINFOSIZE) {
2068 arg->serinfo->dls_cnt ++;
2069 arg->serinfo->dls_size += dirlen + 1;
2070 } else {
2071 struct dl_serpath *s_entry;
2072
2073 s_entry = arg->serpath;
2074 s_entry->dls_name = arg->strspace;
2075 s_entry->dls_flags = arg->flags;
2076
2077 strncpy(arg->strspace, dir, dirlen);
2078 arg->strspace[dirlen] = '\0';
2079
2080 arg->strspace += dirlen + 1;
2081 arg->serpath++;
2082 }
2083
2084 return (NULL);
2085}
2086
2087static int
2088do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2089{
2090 struct dl_serinfo _info;
2091 struct fill_search_info_args args;
2092
2093 args.request = RTLD_DI_SERINFOSIZE;
2094 args.serinfo = &_info;
2095
2096 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2097 _info.dls_cnt = 0;
2098
2099 path_enumerate(ld_library_path, fill_search_info, &args);
2100 path_enumerate(obj->rpath, fill_search_info, &args);
2101 path_enumerate(gethints(), fill_search_info, &args);
2102 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2103
2104
2105 if (request == RTLD_DI_SERINFOSIZE) {
2106 info->dls_size = _info.dls_size;
2107 info->dls_cnt = _info.dls_cnt;
2108 return (0);
2109 }
2110
2111 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2112 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2113 return (-1);
2114 }
2115
2116 args.request = RTLD_DI_SERINFO;
2117 args.serinfo = info;
2118 args.serpath = &info->dls_serpath[0];
2119 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2120
2121 args.flags = LA_SER_LIBPATH;
2122 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2123 return (-1);
2124
2125 args.flags = LA_SER_RUNPATH;
2126 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2127 return (-1);
2128
2129 args.flags = LA_SER_CONFIG;
2130 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2131 return (-1);
2132
2133 args.flags = LA_SER_DEFAULT;
2134 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2135 return (-1);
2136 return (0);
2137}
2138
2139static int
2140rtld_dirname(const char *path, char *bname)
2141{
2142 const char *endp;
2143
2144 /* Empty or NULL string gets treated as "." */
2145 if (path == NULL || *path == '\0') {
2146 bname[0] = '.';
2147 bname[1] = '\0';
2148 return (0);
2149 }
2150
2151 /* Strip trailing slashes */
2152 endp = path + strlen(path) - 1;
2153 while (endp > path && *endp == '/')
2154 endp--;
2155
2156 /* Find the start of the dir */
2157 while (endp > path && *endp != '/')
2158 endp--;
2159
2160 /* Either the dir is "/" or there are no slashes */
2161 if (endp == path) {
2162 bname[0] = *endp == '/' ? '/' : '.';
2163 bname[1] = '\0';
2164 return (0);
2165 } else {
2166 do {
2167 endp--;
2168 } while (endp > path && *endp == '/');
2169 }
2170
2171 if (endp - path + 2 > PATH_MAX)
2172 {
2173 _rtld_error("Filename is too long: %s", path);
2174 return(-1);
2175 }
2176
2177 strncpy(bname, path, endp - path + 1);
2178 bname[endp - path + 1] = '\0';
2179 return (0);
2180}
2181
2182static void
2183linkmap_add(Obj_Entry *obj)
2184{
2185 struct link_map *l = &obj->linkmap;
2186 struct link_map *prev;
2187
2188 obj->linkmap.l_name = obj->path;
2189 obj->linkmap.l_addr = obj->mapbase;
2190 obj->linkmap.l_ld = obj->dynamic;
2191#ifdef __mips__
2192 /* GDB needs load offset on MIPS to use the symbols */
2193 obj->linkmap.l_offs = obj->relocbase;
2194#endif
2195
2196 if (r_debug.r_map == NULL) {
2197 r_debug.r_map = l;
2198 return;
2199 }
2200
2201 /*
2202 * Scan to the end of the list, but not past the entry for the
2203 * dynamic linker, which we want to keep at the very end.
2204 */
2205 for (prev = r_debug.r_map;
2206 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2207 prev = prev->l_next)
2208 ;
2209
2210 /* Link in the new entry. */
2211 l->l_prev = prev;
2212 l->l_next = prev->l_next;
2213 if (l->l_next != NULL)
2214 l->l_next->l_prev = l;
2215 prev->l_next = l;
2216}
2217
2218static void
2219linkmap_delete(Obj_Entry *obj)
2220{
2221 struct link_map *l = &obj->linkmap;
2222
2223 if (l->l_prev == NULL) {
2224 if ((r_debug.r_map = l->l_next) != NULL)
2225 l->l_next->l_prev = NULL;
2226 return;
2227 }
2228
2229 if ((l->l_prev->l_next = l->l_next) != NULL)
2230 l->l_next->l_prev = l->l_prev;
2231}
2232
2233/*
2234 * Function for the debugger to set a breakpoint on to gain control.
2235 *
2236 * The two parameters allow the debugger to easily find and determine
2237 * what the runtime loader is doing and to whom it is doing it.
2238 *
2239 * When the loadhook trap is hit (r_debug_state, set at program
2240 * initialization), the arguments can be found on the stack:
2241 *
2242 * +8 struct link_map *m
2243 * +4 struct r_debug *rd
2244 * +0 RetAddr
2245 */
2246void
2247r_debug_state(struct r_debug* rd, struct link_map *m)
2248{
2249}
2250
2251/*
2252 * Get address of the pointer variable in the main program.
2253 */
2254static const void **
2255get_program_var_addr(const char *name)
2256{
2257 const Obj_Entry *obj;
2258 unsigned long hash;
2259
2260 hash = elf_hash(name);
2261 for (obj = obj_main; obj != NULL; obj = obj->next) {
2262 const Elf_Sym *def;
2263
2264 if ((def = symlook_obj(name, hash, obj, false)) != NULL) {
2265 const void **addr;
2266
2267 addr = (const void **)(obj->relocbase + def->st_value);
2268 return addr;
2269 }
2270 }
2271 return NULL;
2272}
2273
2274/*
2275 * Set a pointer variable in the main program to the given value. This
2276 * is used to set key variables such as "environ" before any of the
2277 * init functions are called.
2278 */
2279static void
2280set_program_var(const char *name, const void *value)
2281{
2282 const void **addr;
2283
2284 if ((addr = get_program_var_addr(name)) != NULL) {
2285 dbg("\"%s\": *%p <-- %p", name, addr, value);
2286 *addr = value;
2287 }
2288}
2289
2290/*
8ca15ec8
MD
2291 * This is a special version of getenv which is far more efficient
2292 * at finding LD_ environment vars.
2293 */
2294static
2295const char *
2296_getenv_ld(const char *id)
2297{
2298 const char *envp;
2299 int i, j;
2300 int idlen = strlen(id);
2301
2302 if (ld_index == LD_ARY_CACHE)
2303 return(getenv(id));
2304 if (ld_index == 0) {
2305 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) {
2306 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_')
2307 ld_ary[j++] = envp;
2308 }
2309 if (j == 0)
2310 ld_ary[j++] = "";
2311 ld_index = j;
2312 }
2313 for (i = ld_index - 1; i >= 0; --i) {
2314 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=')
2315 return(ld_ary[i] + idlen + 1);
2316 }
2317 return(NULL);
2318}
2319
2320/*
984263bc
MD
2321 * Given a symbol name in a referencing object, find the corresponding
2322 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2323 * no definition was found. Returns a pointer to the Obj_Entry of the
2324 * defining object via the reference parameter DEFOBJ_OUT.
2325 */
2326static const Elf_Sym *
2327symlook_default(const char *name, unsigned long hash,
2328 const Obj_Entry *refobj, const Obj_Entry **defobj_out, bool in_plt)
2329{
2330 DoneList donelist;
2331 const Elf_Sym *def;
2332 const Elf_Sym *symp;
2333 const Obj_Entry *obj;
2334 const Obj_Entry *defobj;
2335 const Objlist_Entry *elm;
2336 def = NULL;
2337 defobj = NULL;
2338 donelist_init(&donelist);
2339
2340 /* Look first in the referencing object if linked symbolically. */
2341 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
2342 symp = symlook_obj(name, hash, refobj, in_plt);
2343 if (symp != NULL) {
2344 def = symp;
2345 defobj = refobj;
2346 }
2347 }
2348
2349 /* Search all objects loaded at program start up. */
2350 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2351 symp = symlook_list(name, hash, &list_main, &obj, in_plt, &donelist);
2352 if (symp != NULL &&
2353 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2354 def = symp;
2355 defobj = obj;
2356 }
2357 }
2358
2359 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2360 STAILQ_FOREACH(elm, &list_global, link) {
2361 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2362 break;
2363 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2364 &donelist);
2365 if (symp != NULL &&
2366 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2367 def = symp;
2368 defobj = obj;
2369 }
2370 }
2371
2372 /* Search all dlopened DAGs containing the referencing object. */
2373 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2374 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2375 break;
2376 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2377 &donelist);
2378 if (symp != NULL &&
2379 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2380 def = symp;
2381 defobj = obj;
2382 }
2383 }
2384
2385 /*
2386 * Search the dynamic linker itself, and possibly resolve the
2387 * symbol from there. This is how the application links to
2388 * dynamic linker services such as dlopen. Only the values listed
2389 * in the "exports" array can be resolved from the dynamic linker.
2390 */
2391 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2392 symp = symlook_obj(name, hash, &obj_rtld, in_plt);
2393 if (symp != NULL && is_exported(symp)) {
2394 def = symp;
2395 defobj = &obj_rtld;
2396 }
2397 }
2398
2399 if (def != NULL)
2400 *defobj_out = defobj;
2401 return def;
2402}
2403
2404static const Elf_Sym *
fb0c631e 2405symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
984263bc
MD
2406 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2407{
2408 const Elf_Sym *symp;
2409 const Elf_Sym *def;
2410 const Obj_Entry *defobj;
2411 const Objlist_Entry *elm;
2412
2413 def = NULL;
2414 defobj = NULL;
2415 STAILQ_FOREACH(elm, objlist, link) {
2416 if (donelist_check(dlp, elm->obj))
2417 continue;
2418 if ((symp = symlook_obj(name, hash, elm->obj, in_plt)) != NULL) {
2419 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2420 def = symp;
2421 defobj = elm->obj;
2422 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2423 break;
2424 }
2425 }
2426 }
2427 if (def != NULL)
2428 *defobj_out = defobj;
2429 return def;
2430}
2431
2432/*
cebaf0af
SS
2433 * Search the symbol table of a shared object and all objects needed
2434 * by it for a symbol of the given name. Search order is
2435 * breadth-first. Returns a pointer to the symbol, or NULL if no
2436 * definition was found.
2437 */
2438static const Elf_Sym *
2439symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
2440 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2441{
2442 const Elf_Sym *def, *def_w;
2443 const Needed_Entry *n;
2444 const Obj_Entry *obj, *defobj, *defobj1;
2445
2446 def = def_w = NULL;
2447 defobj = NULL;
2448 for (n = needed; n != NULL; n = n->next) {
2449 if ((obj = n->obj) == NULL ||
2450 donelist_check(dlp, obj) ||
2451 (def = symlook_obj(name, hash, obj, in_plt)) == NULL)
2452 continue;
2453 defobj = obj;
2454 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2455 *defobj_out = defobj;
2456 return (def);
2457 }
2458 }
2459 /*
2460 * There we come when either symbol definition is not found in
2461 * directly needed objects, or found symbol is weak.
2462 */
2463 for (n = needed; n != NULL; n = n->next) {
2464 if ((obj = n->obj) == NULL)
2465 continue;
2466 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
2467 in_plt, dlp);
2468 if (def_w == NULL)
2469 continue;
2470 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
2471 def = def_w;
2472 defobj = defobj1;
2473 }
2474 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
2475 break;
2476 }
2477 if (def != NULL)
2478 *defobj_out = defobj;
2479 return def;
2480}
2481
2482/*
984263bc
MD
2483 * Search the symbol table of a single shared object for a symbol of
2484 * the given name. Returns a pointer to the symbol, or NULL if no
2485 * definition was found.
2486 *
2487 * The symbol's hash value is passed in for efficiency reasons; that
2488 * eliminates many recomputations of the hash value.
2489 */
2490const Elf_Sym *
2491symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
2492 bool in_plt)
2493{
2494 if (obj->buckets != NULL) {
2495 unsigned long symnum = obj->buckets[hash % obj->nbuckets];
2496
2497 while (symnum != STN_UNDEF) {
2498 const Elf_Sym *symp;
2499 const char *strp;
2500
2501 if (symnum >= obj->nchains)
2502 return NULL; /* Bad object */
139b8f34 2503
984263bc
MD
2504 symp = obj->symtab + symnum;
2505 strp = obj->strtab + symp->st_name;
2506
2507 if (name[0] == strp[0] && strcmp(name, strp) == 0)
2508 return symp->st_shndx != SHN_UNDEF ||
2509 (!in_plt && symp->st_value != 0 &&
2510 ELF_ST_TYPE(symp->st_info) == STT_FUNC) ? symp : NULL;
2511
2512 symnum = obj->chains[symnum];
2513 }
2514 }
2515 return NULL;
2516}
2517
2518static void
2519trace_loaded_objects(Obj_Entry *obj)
2520{
8ca15ec8 2521 const char *fmt1, *fmt2, *fmt, *main_local;
984263bc
MD
2522 int c;
2523
8ca15ec8 2524 if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
984263bc
MD
2525 main_local = "";
2526
8ca15ec8 2527 if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL)
984263bc
MD
2528 fmt1 = "\t%o => %p (%x)\n";
2529
8ca15ec8 2530 if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
984263bc
MD
2531 fmt2 = "\t%o (%x)\n";
2532
2533 for (; obj; obj = obj->next) {
2534 Needed_Entry *needed;
2535 char *name, *path;
2536 bool is_lib;
2537
2538 for (needed = obj->needed; needed; needed = needed->next) {
2539 if (needed->obj != NULL) {
2540 if (needed->obj->traced)
2541 continue;
2542 needed->obj->traced = true;
2543 path = needed->obj->path;
2544 } else
2545 path = "not found";
2546
2547 name = (char *)obj->strtab + needed->name;
2548 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
2549
2550 fmt = is_lib ? fmt1 : fmt2;
2551 while ((c = *fmt++) != '\0') {
2552 switch (c) {
2553 default:
2554 putchar(c);
2555 continue;
2556 case '\\':
2557 switch (c = *fmt) {
2558 case '\0':
2559 continue;
2560 case 'n':
2561 putchar('\n');
2562 break;
2563 case 't':
2564 putchar('\t');
2565 break;
2566 }
2567 break;
2568 case '%':
2569 switch (c = *fmt) {
2570 case '\0':
2571 continue;
2572 case '%':
2573 default:
2574 putchar(c);
2575 break;
2576 case 'A':
2577 printf("%s", main_local);
2578 break;
2579 case 'a':
2580 printf("%s", obj_main->path);
2581 break;
2582 case 'o':
2583 printf("%s", name);
2584 break;
2585#if 0
2586 case 'm':
2587 printf("%d", sodp->sod_major);
2588 break;
2589 case 'n':
2590 printf("%d", sodp->sod_minor);
2591 break;
2592#endif
2593 case 'p':
2594 printf("%s", path);
2595 break;
2596 case 'x':
2597 printf("%p", needed->obj ? needed->obj->mapbase : 0);
2598 break;
2599 }
2600 break;
2601 }
2602 ++fmt;
2603 }
2604 }
2605 }
2606}
2607
2608/*
2609 * Unload a dlopened object and its dependencies from memory and from
2610 * our data structures. It is assumed that the DAG rooted in the
2611 * object has already been unreferenced, and that the object has a
2612 * reference count of 0.
2613 */
2614static void
2615unload_object(Obj_Entry *root)
2616{
2617 Obj_Entry *obj;
2618 Obj_Entry **linkp;
2619
2620 assert(root->refcount == 0);
2621
2622 /*
2623 * Pass over the DAG removing unreferenced objects from
2624 * appropriate lists.
2625 */
2626 unlink_object(root);
2627
2628 /* Unmap all objects that are no longer referenced. */
2629 linkp = &obj_list->next;
2630 while ((obj = *linkp) != NULL) {
2631 if (obj->refcount == 0) {
2632 dbg("unloading \"%s\"", obj->path);
2633 munmap(obj->mapbase, obj->mapsize);
2634 linkmap_delete(obj);
2635 *linkp = obj->next;
2636 obj_count--;
2637 obj_free(obj);
2638 } else
2639 linkp = &obj->next;
2640 }
2641 obj_tail = linkp;
2642}
2643
2644static void
2645unlink_object(Obj_Entry *root)
2646{
2647 const Needed_Entry *needed;
2648 Objlist_Entry *elm;
2649
2650 if (root->refcount == 0) {
2651 /* Remove the object from the RTLD_GLOBAL list. */
2652 objlist_remove(&list_global, root);
2653
2654 /* Remove the object from all objects' DAG lists. */
2655 STAILQ_FOREACH(elm, &root->dagmembers , link)
2656 objlist_remove(&elm->obj->dldags, root);
2657 }
2658
2659 for (needed = root->needed; needed != NULL; needed = needed->next)
2660 if (needed->obj != NULL)
2661 unlink_object(needed->obj);
2662}
2663
2664static void
2665unref_dag(Obj_Entry *root)
2666{
2667 const Needed_Entry *needed;
2668
2669 if (root->refcount == 0)
2670 return;
2671 root->refcount--;
2672 if (root->refcount == 0)
2673 for (needed = root->needed; needed != NULL; needed = needed->next)
2674 if (needed->obj != NULL)
2675 unref_dag(needed->obj);
2676}
55b88cae
DX
2677
2678/*
2679 * Common code for MD __tls_get_addr().
2680 */
2681void *
bc633d63 2682tls_get_addr_common(void **dtvp, int index, size_t offset)
55b88cae
DX
2683{
2684 Elf_Addr* dtv = *dtvp;
2685
2686 /* Check dtv generation in case new modules have arrived */
2687 if (dtv[0] != tls_dtv_generation) {
2688 Elf_Addr* newdtv;
2689 int to_copy;
2690
2691 wlock_acquire();
2692
2693 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
2694 to_copy = dtv[1];
2695 if (to_copy > tls_max_index)
2696 to_copy = tls_max_index;
2697 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
2698 newdtv[0] = tls_dtv_generation;
2699 newdtv[1] = tls_max_index;
2700 free(dtv);
bc633d63 2701 *dtvp = newdtv;
55b88cae
DX
2702
2703 wlock_release();
55b88cae
DX
2704 }
2705
2706 /* Dynamically allocate module TLS if necessary */
2707 if (!dtv[index + 1]) {
2708 /* XXX
2709 * here we should avoid to be re-entered by signal handler
2710 * code, I assume wlock_acquire will masked all signals,
2711 * otherwise there is race and dead lock thread itself.
2712 */
2713 wlock_acquire();
2714 if (!dtv[index + 1])
2715 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
2716 wlock_release();
2717 }
55b88cae
DX
2718 return (void*) (dtv[index + 1] + offset);
2719}
2720
9e2ee207 2721#if defined(RTLD_STATIC_TLS_VARIANT_II)
55b88cae
DX
2722
2723/*
bc633d63
MD
2724 * Allocate the static TLS area. Return a pointer to the TCB. The
2725 * static area is based on negative offsets relative to the tcb.
a1eee96a
MD
2726 *
2727 * The TCB contains an errno pointer for the system call layer, but because
2728 * we are the RTLD we really have no idea how the caller was compiled so
2729 * the information has to be passed in. errno can either be:
2730 *
2731 * type 0 errno is a simple non-TLS global pointer.
2732 * (special case for e.g. libc_rtld)
2733 * type 1 errno accessed by GOT entry (dynamically linked programs)
2734 * type 2 errno accessed by %gs:OFFSET (statically linked programs)
55b88cae 2735 */
bc633d63 2736struct tls_tcb *
a1eee96a 2737allocate_tls(Obj_Entry *objs)
55b88cae
DX
2738{
2739 Obj_Entry *obj;
bc633d63 2740 size_t data_size;
bc633d63
MD
2741 size_t dtv_size;
2742 struct tls_tcb *tcb;
a1eee96a 2743 Elf_Addr *dtv;
bc633d63 2744 Elf_Addr addr;
55b88cae 2745
bc633d63
MD
2746 /*
2747 * Allocate the new TCB. static TLS storage is placed just before the
2748 * TCB to support the %gs:OFFSET (negative offset) model.
2749 */
bc633d63
MD
2750 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
2751 ~RTLD_STATIC_TLS_ALIGN_MASK;
f20fd431 2752 tcb = malloc(data_size + sizeof(*tcb));
bc633d63 2753 tcb = (void *)((char *)tcb + data_size); /* actual tcb location */
55b88cae 2754
bc633d63
MD
2755 dtv_size = (tls_max_index + 2) * sizeof(Elf_Addr);
2756 dtv = malloc(dtv_size);
2757 bzero(dtv, dtv_size);
55b88cae 2758
9e2ee207
JS
2759#ifdef RTLD_TCB_HAS_SELF_POINTER
2760 tcb->tcb_self = tcb;
2761#endif
2762 tcb->tcb_dtv = dtv;
2763 tcb->tcb_pthread = NULL;
55b88cae
DX
2764
2765 dtv[0] = tls_dtv_generation;
2766 dtv[1] = tls_max_index;
2767
a1eee96a
MD
2768 for (obj = objs; obj; obj = obj->next) {
2769 if (obj->tlsoffset) {
2770 addr = (Elf_Addr)tcb - obj->tlsoffset;
2771 memset((void *)(addr + obj->tlsinitsize),
2772 0, obj->tlssize - obj->tlsinitsize);
2773 if (obj->tlsinit)
2774 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
2775 dtv[obj->tlsindex + 1] = addr;
55b88cae
DX
2776 }
2777 }
bc633d63 2778 return(tcb);
55b88cae
DX
2779}
2780
2781void
f20fd431 2782free_tls(struct tls_tcb *tcb)
bc633d63
MD
2783{
2784 Elf_Addr *dtv;
2785 int dtv_size, i;
2786 Elf_Addr tls_start, tls_end;
2787 size_t data_size;
2788
2789 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
2790 ~RTLD_STATIC_TLS_ALIGN_MASK;
9e2ee207 2791 dtv = tcb->tcb_dtv;
bc633d63
MD
2792 dtv_size = dtv[1];
2793 tls_end = (Elf_Addr)tcb;
2794 tls_start = (Elf_Addr)tcb - data_size;
2795 for (i = 0; i < dtv_size; i++) {
eecd52b2 2796 if (dtv[i+2] != 0 && (dtv[i+2] < tls_start || dtv[i+2] > tls_end)) {
bc633d63 2797 free((void *)dtv[i+2]);
55b88cae
DX
2798 }
2799 }
bc633d63 2800 free((void *)tls_start);
55b88cae
DX
2801}
2802
9e2ee207
JS
2803#else
2804#error "Unsupported TLS layout"
55b88cae
DX
2805#endif
2806
2807/*
2808 * Allocate TLS block for module with given index.
2809 */
2810void *
2811allocate_module_tls(int index)
2812{
2813 Obj_Entry* obj;
2814 char* p;
2815
2816 for (obj = obj_list; obj; obj = obj->next) {
2817 if (obj->tlsindex == index)
2818 break;
2819 }
2820 if (!obj) {
2821 _rtld_error("Can't find module with TLS index %d", index);
2822 die();
2823 }
2824
2825 p = malloc(obj->tlssize);
2826 memcpy(p, obj->tlsinit, obj->tlsinitsize);
2827 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
2828
2829 return p;
2830}
2831
2832bool
2833allocate_tls_offset(Obj_Entry *obj)
2834{
2835 size_t off;
2836
2837 if (obj->tls_done)
2838 return true;
2839
2840 if (obj->tlssize == 0) {
2841 obj->tls_done = true;
2842 return true;
2843 }
2844
2845 if (obj->tlsindex == 1)
2846 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
2847 else
2848 off = calculate_tls_offset(tls_last_offset, tls_last_size,
2849 obj->tlssize, obj->tlsalign);
2850
2851 /*
2852 * If we have already fixed the size of the static TLS block, we
2853 * must stay within that size. When allocating the static TLS, we
2854 * leave a small amount of space spare to be used for dynamically
2855 * loading modules which use static TLS.
2856 */
2857 if (tls_static_space) {
2858 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
2859 return false;
2860 }
2861
2862 tls_last_offset = obj->tlsoffset = off;
2863 tls_last_size = obj->tlssize;
2864 obj->tls_done = true;
2865
2866 return true;
2867}
2868
2869void
2870free_tls_offset(Obj_Entry *obj)
2871{
9e2ee207 2872#ifdef RTLD_STATIC_TLS_VARIANT_II
55b88cae
DX
2873 /*
2874 * If we were the last thing to allocate out of the static TLS
2875 * block, we give our space back to the 'allocator'. This is a
2876 * simplistic workaround to allow libGL.so.1 to be loaded and
2877 * unloaded multiple times. We only handle the Variant II
2878 * mechanism for now - this really needs a proper allocator.
2879 */
2880 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
2881 == calculate_tls_end(tls_last_offset, tls_last_size)) {
2882 tls_last_offset -= obj->tlssize;
2883 tls_last_size = 0;
2884 }
2885#endif
2886}
2887
bc633d63 2888struct tls_tcb *
a1eee96a 2889_rtld_allocate_tls(void)
55b88cae 2890{
bc633d63 2891 struct tls_tcb *new_tcb;
55b88cae
DX
2892
2893 wlock_acquire();
a1eee96a 2894 new_tcb = allocate_tls(obj_list);
55b88cae
DX
2895 wlock_release();
2896
bc633d63 2897 return (new_tcb);
55b88cae
DX
2898}
2899
2900void
f20fd431 2901_rtld_free_tls(struct tls_tcb *tcb)
55b88cae
DX
2902{
2903 wlock_acquire();
f20fd431 2904 free_tls(tcb);
55b88cae
DX
2905 wlock_release();
2906}
bc633d63 2907