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rtld.c (212497) rtld.c (214728)
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 *
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: head/libexec/rtld-elf/rtld.c 212497 2010-09-12 17:04:51Z nwhitehorn $
26 * $FreeBSD: head/libexec/rtld-elf/rtld.c 214728 2010-11-03 09:23:08Z kib $
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/mount.h>
41#include <sys/mman.h>
42#include <sys/stat.h>
43#include <sys/sysctl.h>
44#include <sys/uio.h>
45#include <sys/utsname.h>
46#include <sys/ktrace.h>
47
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#include "libmap.h"
61#include "rtld_tls.h"
62
63#ifndef COMPAT_32BIT
64#define PATH_RTLD "/libexec/ld-elf.so.1"
65#else
66#define PATH_RTLD "/libexec/ld-elf32.so.1"
67#endif
68
69/* Types. */
70typedef void (*func_ptr_type)();
71typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
72
73/*
74 * This structure provides a reentrant way to keep a list of objects and
75 * check which ones have already been processed in some way.
76 */
77typedef struct Struct_DoneList {
78 const Obj_Entry **objs; /* Array of object pointers */
79 unsigned int num_alloc; /* Allocated size of the array */
80 unsigned int num_used; /* Number of array slots used */
81} DoneList;
82
83/*
84 * Function declarations.
85 */
86static const char *basename(const char *);
87static void die(void) __dead2;
88static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
89 const Elf_Dyn **);
90static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *);
91static void digest_dynamic(Obj_Entry *, int);
92static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
93static Obj_Entry *dlcheck(void *);
94static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
95static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
96static bool donelist_check(DoneList *, const Obj_Entry *);
97static void errmsg_restore(char *);
98static char *errmsg_save(void);
99static void *fill_search_info(const char *, size_t, void *);
100static char *find_library(const char *, const Obj_Entry *);
101static const char *gethints(void);
102static void init_dag(Obj_Entry *);
103static void init_dag1(Obj_Entry *, Obj_Entry *, DoneList *);
104static void init_rtld(caddr_t, Elf_Auxinfo **);
105static void initlist_add_neededs(Needed_Entry *, Objlist *);
106static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
107static void linkmap_add(Obj_Entry *);
108static void linkmap_delete(Obj_Entry *);
109static int load_needed_objects(Obj_Entry *, int);
110static int load_preload_objects(void);
111static Obj_Entry *load_object(const char *, const Obj_Entry *, int);
112static Obj_Entry *obj_from_addr(const void *);
113static void objlist_call_fini(Objlist *, bool, int *);
114static void objlist_call_init(Objlist *, int *);
115static void objlist_clear(Objlist *);
116static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
117static void objlist_init(Objlist *);
118static void objlist_push_head(Objlist *, Obj_Entry *);
119static void objlist_push_tail(Objlist *, Obj_Entry *);
120static void objlist_remove(Objlist *, Obj_Entry *);
121static void *path_enumerate(const char *, path_enum_proc, void *);
122static int relocate_objects(Obj_Entry *, bool, Obj_Entry *);
123static int rtld_dirname(const char *, char *);
124static int rtld_dirname_abs(const char *, char *);
125static void rtld_exit(void);
126static char *search_library_path(const char *, const char *);
127static const void **get_program_var_addr(const char *);
128static void set_program_var(const char *, const void *);
129static const Elf_Sym *symlook_default(const char *, unsigned long,
130 const Obj_Entry *, const Obj_Entry **, const Ver_Entry *, int);
131static const Elf_Sym *symlook_list(const char *, unsigned long, const Objlist *,
132 const Obj_Entry **, const Ver_Entry *, int, DoneList *);
133static const Elf_Sym *symlook_needed(const char *, unsigned long,
134 const Needed_Entry *, const Obj_Entry **, const Ver_Entry *,
135 int, DoneList *);
136static void trace_loaded_objects(Obj_Entry *);
137static void unlink_object(Obj_Entry *);
138static void unload_object(Obj_Entry *);
139static void unref_dag(Obj_Entry *);
140static void ref_dag(Obj_Entry *);
141static int origin_subst_one(char **, const char *, const char *,
142 const char *, char *);
143static char *origin_subst(const char *, const char *);
144static int rtld_verify_versions(const Objlist *);
145static int rtld_verify_object_versions(Obj_Entry *);
146static void object_add_name(Obj_Entry *, const char *);
147static int object_match_name(const Obj_Entry *, const char *);
148static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
149static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
150 struct dl_phdr_info *phdr_info);
151
152void r_debug_state(struct r_debug *, struct link_map *);
153
154/*
155 * Data declarations.
156 */
157static char *error_message; /* Message for dlerror(), or NULL */
158struct r_debug r_debug; /* for GDB; */
159static bool libmap_disable; /* Disable libmap */
160static char *libmap_override; /* Maps to use in addition to libmap.conf */
161static bool trust; /* False for setuid and setgid programs */
162static bool dangerous_ld_env; /* True if environment variables have been
163 used to affect the libraries loaded */
164static char *ld_bind_now; /* Environment variable for immediate binding */
165static char *ld_debug; /* Environment variable for debugging */
166static char *ld_library_path; /* Environment variable for search path */
167static char *ld_preload; /* Environment variable for libraries to
168 load first */
169static char *ld_elf_hints_path; /* Environment variable for alternative hints path */
170static char *ld_tracing; /* Called from ldd to print libs */
171static char *ld_utrace; /* Use utrace() to log events. */
172static Obj_Entry *obj_list; /* Head of linked list of shared objects */
173static Obj_Entry **obj_tail; /* Link field of last object in list */
174static Obj_Entry *obj_main; /* The main program shared object */
175static Obj_Entry obj_rtld; /* The dynamic linker shared object */
176static unsigned int obj_count; /* Number of objects in obj_list */
177static unsigned int obj_loads; /* Number of objects in obj_list */
178
179static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
180 STAILQ_HEAD_INITIALIZER(list_global);
181static Objlist list_main = /* Objects loaded at program startup */
182 STAILQ_HEAD_INITIALIZER(list_main);
183static Objlist list_fini = /* Objects needing fini() calls */
184 STAILQ_HEAD_INITIALIZER(list_fini);
185
186Elf_Sym sym_zero; /* For resolving undefined weak refs. */
187
188#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
189
190extern Elf_Dyn _DYNAMIC;
191#pragma weak _DYNAMIC
192#ifndef RTLD_IS_DYNAMIC
193#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL)
194#endif
195
196int osreldate, pagesize;
197
198/*
199 * Global declarations normally provided by crt1. The dynamic linker is
200 * not built with crt1, so we have to provide them ourselves.
201 */
202char *__progname;
203char **environ;
204
205/*
206 * Globals to control TLS allocation.
207 */
208size_t tls_last_offset; /* Static TLS offset of last module */
209size_t tls_last_size; /* Static TLS size of last module */
210size_t tls_static_space; /* Static TLS space allocated */
211int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
212int tls_max_index = 1; /* Largest module index allocated */
213
214/*
215 * Fill in a DoneList with an allocation large enough to hold all of
216 * the currently-loaded objects. Keep this as a macro since it calls
217 * alloca and we want that to occur within the scope of the caller.
218 */
219#define donelist_init(dlp) \
220 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
221 assert((dlp)->objs != NULL), \
222 (dlp)->num_alloc = obj_count, \
223 (dlp)->num_used = 0)
224
225#define UTRACE_DLOPEN_START 1
226#define UTRACE_DLOPEN_STOP 2
227#define UTRACE_DLCLOSE_START 3
228#define UTRACE_DLCLOSE_STOP 4
229#define UTRACE_LOAD_OBJECT 5
230#define UTRACE_UNLOAD_OBJECT 6
231#define UTRACE_ADD_RUNDEP 7
232#define UTRACE_PRELOAD_FINISHED 8
233#define UTRACE_INIT_CALL 9
234#define UTRACE_FINI_CALL 10
235
236struct utrace_rtld {
237 char sig[4]; /* 'RTLD' */
238 int event;
239 void *handle;
240 void *mapbase; /* Used for 'parent' and 'init/fini' */
241 size_t mapsize;
242 int refcnt; /* Used for 'mode' */
243 char name[MAXPATHLEN];
244};
245
246#define LD_UTRACE(e, h, mb, ms, r, n) do { \
247 if (ld_utrace != NULL) \
248 ld_utrace_log(e, h, mb, ms, r, n); \
249} while (0)
250
251static void
252ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
253 int refcnt, const char *name)
254{
255 struct utrace_rtld ut;
256
257 ut.sig[0] = 'R';
258 ut.sig[1] = 'T';
259 ut.sig[2] = 'L';
260 ut.sig[3] = 'D';
261 ut.event = event;
262 ut.handle = handle;
263 ut.mapbase = mapbase;
264 ut.mapsize = mapsize;
265 ut.refcnt = refcnt;
266 bzero(ut.name, sizeof(ut.name));
267 if (name)
268 strlcpy(ut.name, name, sizeof(ut.name));
269 utrace(&ut, sizeof(ut));
270}
271
272/*
273 * Main entry point for dynamic linking. The first argument is the
274 * stack pointer. The stack is expected to be laid out as described
275 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
276 * Specifically, the stack pointer points to a word containing
277 * ARGC. Following that in the stack is a null-terminated sequence
278 * of pointers to argument strings. Then comes a null-terminated
279 * sequence of pointers to environment strings. Finally, there is a
280 * sequence of "auxiliary vector" entries.
281 *
282 * The second argument points to a place to store the dynamic linker's
283 * exit procedure pointer and the third to a place to store the main
284 * program's object.
285 *
286 * The return value is the main program's entry point.
287 */
288func_ptr_type
289_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
290{
291 Elf_Auxinfo *aux_info[AT_COUNT];
292 int i;
293 int argc;
294 char **argv;
295 char **env;
296 Elf_Auxinfo *aux;
297 Elf_Auxinfo *auxp;
298 const char *argv0;
299 Objlist_Entry *entry;
300 Obj_Entry *obj;
301 Obj_Entry **preload_tail;
302 Objlist initlist;
303 int lockstate;
304
305 /*
306 * On entry, the dynamic linker itself has not been relocated yet.
307 * Be very careful not to reference any global data until after
308 * init_rtld has returned. It is OK to reference file-scope statics
309 * and string constants, and to call static and global functions.
310 */
311
312 /* Find the auxiliary vector on the stack. */
313 argc = *sp++;
314 argv = (char **) sp;
315 sp += argc + 1; /* Skip over arguments and NULL terminator */
316 env = (char **) sp;
317 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
318 ;
319 aux = (Elf_Auxinfo *) sp;
320
321 /* Digest the auxiliary vector. */
322 for (i = 0; i < AT_COUNT; i++)
323 aux_info[i] = NULL;
324 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
325 if (auxp->a_type < AT_COUNT)
326 aux_info[auxp->a_type] = auxp;
327 }
328
329 /* Initialize and relocate ourselves. */
330 assert(aux_info[AT_BASE] != NULL);
331 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
332
333 __progname = obj_rtld.path;
334 argv0 = argv[0] != NULL ? argv[0] : "(null)";
335 environ = env;
336
337 trust = !issetugid();
338
339 ld_bind_now = getenv(LD_ "BIND_NOW");
340 /*
341 * If the process is tainted, then we un-set the dangerous environment
342 * variables. The process will be marked as tainted until setuid(2)
343 * is called. If any child process calls setuid(2) we do not want any
344 * future processes to honor the potentially un-safe variables.
345 */
346 if (!trust) {
347 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") ||
348 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") ||
349 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH")) {
350 _rtld_error("environment corrupt; aborting");
351 die();
352 }
353 }
354 ld_debug = getenv(LD_ "DEBUG");
355 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL;
356 libmap_override = getenv(LD_ "LIBMAP");
357 ld_library_path = getenv(LD_ "LIBRARY_PATH");
358 ld_preload = getenv(LD_ "PRELOAD");
359 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH");
360 dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
361 (ld_library_path != NULL) || (ld_preload != NULL) ||
362 (ld_elf_hints_path != NULL);
363 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS");
364 ld_utrace = getenv(LD_ "UTRACE");
365
366 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
367 ld_elf_hints_path = _PATH_ELF_HINTS;
368
369 if (ld_debug != NULL && *ld_debug != '\0')
370 debug = 1;
371 dbg("%s is initialized, base address = %p", __progname,
372 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
373 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
374 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
375
376 /*
377 * Load the main program, or process its program header if it is
378 * already loaded.
379 */
380 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
381 int fd = aux_info[AT_EXECFD]->a_un.a_val;
382 dbg("loading main program");
383 obj_main = map_object(fd, argv0, NULL);
384 close(fd);
385 if (obj_main == NULL)
386 die();
387 } else { /* Main program already loaded. */
388 const Elf_Phdr *phdr;
389 int phnum;
390 caddr_t entry;
391
392 dbg("processing main program's program header");
393 assert(aux_info[AT_PHDR] != NULL);
394 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
395 assert(aux_info[AT_PHNUM] != NULL);
396 phnum = aux_info[AT_PHNUM]->a_un.a_val;
397 assert(aux_info[AT_PHENT] != NULL);
398 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
399 assert(aux_info[AT_ENTRY] != NULL);
400 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
401 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
402 die();
403 }
404
405 if (aux_info[AT_EXECPATH] != 0) {
406 char *kexecpath;
407 char buf[MAXPATHLEN];
408
409 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
410 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
411 if (kexecpath[0] == '/')
412 obj_main->path = kexecpath;
413 else if (getcwd(buf, sizeof(buf)) == NULL ||
414 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
415 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
416 obj_main->path = xstrdup(argv0);
417 else
418 obj_main->path = xstrdup(buf);
419 } else {
420 dbg("No AT_EXECPATH");
421 obj_main->path = xstrdup(argv0);
422 }
423 dbg("obj_main path %s", obj_main->path);
424 obj_main->mainprog = true;
425
426 /*
427 * Get the actual dynamic linker pathname from the executable if
428 * possible. (It should always be possible.) That ensures that
429 * gdb will find the right dynamic linker even if a non-standard
430 * one is being used.
431 */
432 if (obj_main->interp != NULL &&
433 strcmp(obj_main->interp, obj_rtld.path) != 0) {
434 free(obj_rtld.path);
435 obj_rtld.path = xstrdup(obj_main->interp);
436 __progname = obj_rtld.path;
437 }
438
439 digest_dynamic(obj_main, 0);
440
441 linkmap_add(obj_main);
442 linkmap_add(&obj_rtld);
443
444 /* Link the main program into the list of objects. */
445 *obj_tail = obj_main;
446 obj_tail = &obj_main->next;
447 obj_count++;
448 obj_loads++;
449 /* Make sure we don't call the main program's init and fini functions. */
450 obj_main->init = obj_main->fini = (Elf_Addr)NULL;
451
452 /* Initialize a fake symbol for resolving undefined weak references. */
453 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
454 sym_zero.st_shndx = SHN_UNDEF;
455 sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
456
457 if (!libmap_disable)
458 libmap_disable = (bool)lm_init(libmap_override);
459
460 dbg("loading LD_PRELOAD libraries");
461 if (load_preload_objects() == -1)
462 die();
463 preload_tail = obj_tail;
464
465 dbg("loading needed objects");
466 if (load_needed_objects(obj_main, 0) == -1)
467 die();
468
469 /* Make a list of all objects loaded at startup. */
470 for (obj = obj_list; obj != NULL; obj = obj->next) {
471 objlist_push_tail(&list_main, obj);
472 obj->refcount++;
473 }
474
475 dbg("checking for required versions");
476 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
477 die();
478
479 if (ld_tracing) { /* We're done */
480 trace_loaded_objects(obj_main);
481 exit(0);
482 }
483
484 if (getenv(LD_ "DUMP_REL_PRE") != NULL) {
485 dump_relocations(obj_main);
486 exit (0);
487 }
488
489 /* setup TLS for main thread */
490 dbg("initializing initial thread local storage");
491 STAILQ_FOREACH(entry, &list_main, link) {
492 /*
493 * Allocate all the initial objects out of the static TLS
494 * block even if they didn't ask for it.
495 */
496 allocate_tls_offset(entry->obj);
497 }
498 allocate_initial_tls(obj_list);
499
500 if (relocate_objects(obj_main,
501 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
502 die();
503
504 dbg("doing copy relocations");
505 if (do_copy_relocations(obj_main) == -1)
506 die();
507
508 if (getenv(LD_ "DUMP_REL_POST") != NULL) {
509 dump_relocations(obj_main);
510 exit (0);
511 }
512
513 dbg("initializing key program variables");
514 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
515 set_program_var("environ", env);
516 set_program_var("__elf_aux_vector", aux);
517
518 dbg("initializing thread locks");
519 lockdflt_init();
520
521 /* Make a list of init functions to call. */
522 objlist_init(&initlist);
523 initlist_add_objects(obj_list, preload_tail, &initlist);
524
525 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
526
527 lockstate = wlock_acquire(rtld_bind_lock);
528 objlist_call_init(&initlist, &lockstate);
529 objlist_clear(&initlist);
530 wlock_release(rtld_bind_lock, lockstate);
531
532 dbg("transferring control to program entry point = %p", obj_main->entry);
533
534 /* Return the exit procedure and the program entry point. */
535 *exit_proc = rtld_exit;
536 *objp = obj_main;
537 return (func_ptr_type) obj_main->entry;
538}
539
540Elf_Addr
541_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
542{
543 const Elf_Rel *rel;
544 const Elf_Sym *def;
545 const Obj_Entry *defobj;
546 Elf_Addr *where;
547 Elf_Addr target;
548 int lockstate;
549
550 lockstate = rlock_acquire(rtld_bind_lock);
551 if (obj->pltrel)
552 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
553 else
554 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
555
556 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
557 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
558 if (def == NULL)
559 die();
560
561 target = (Elf_Addr)(defobj->relocbase + def->st_value);
562
563 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
564 defobj->strtab + def->st_name, basename(obj->path),
565 (void *)target, basename(defobj->path));
566
567 /*
568 * Write the new contents for the jmpslot. Note that depending on
569 * architecture, the value which we need to return back to the
570 * lazy binding trampoline may or may not be the target
571 * address. The value returned from reloc_jmpslot() is the value
572 * that the trampoline needs.
573 */
574 target = reloc_jmpslot(where, target, defobj, obj, rel);
575 rlock_release(rtld_bind_lock, lockstate);
576 return target;
577}
578
579/*
580 * Error reporting function. Use it like printf. If formats the message
581 * into a buffer, and sets things up so that the next call to dlerror()
582 * will return the message.
583 */
584void
585_rtld_error(const char *fmt, ...)
586{
587 static char buf[512];
588 va_list ap;
589
590 va_start(ap, fmt);
591 vsnprintf(buf, sizeof buf, fmt, ap);
592 error_message = buf;
593 va_end(ap);
594}
595
596/*
597 * Return a dynamically-allocated copy of the current error message, if any.
598 */
599static char *
600errmsg_save(void)
601{
602 return error_message == NULL ? NULL : xstrdup(error_message);
603}
604
605/*
606 * Restore the current error message from a copy which was previously saved
607 * by errmsg_save(). The copy is freed.
608 */
609static void
610errmsg_restore(char *saved_msg)
611{
612 if (saved_msg == NULL)
613 error_message = NULL;
614 else {
615 _rtld_error("%s", saved_msg);
616 free(saved_msg);
617 }
618}
619
620static const char *
621basename(const char *name)
622{
623 const char *p = strrchr(name, '/');
624 return p != NULL ? p + 1 : name;
625}
626
627static struct utsname uts;
628
629static int
630origin_subst_one(char **res, const char *real, const char *kw, const char *subst,
631 char *may_free)
632{
633 const char *p, *p1;
634 char *res1;
635 int subst_len;
636 int kw_len;
637
638 res1 = *res = NULL;
639 p = real;
640 subst_len = kw_len = 0;
641 for (;;) {
642 p1 = strstr(p, kw);
643 if (p1 != NULL) {
644 if (subst_len == 0) {
645 subst_len = strlen(subst);
646 kw_len = strlen(kw);
647 }
648 if (*res == NULL) {
649 *res = xmalloc(PATH_MAX);
650 res1 = *res;
651 }
652 if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) {
653 _rtld_error("Substitution of %s in %s cannot be performed",
654 kw, real);
655 if (may_free != NULL)
656 free(may_free);
657 free(res);
658 return (false);
659 }
660 memcpy(res1, p, p1 - p);
661 res1 += p1 - p;
662 memcpy(res1, subst, subst_len);
663 res1 += subst_len;
664 p = p1 + kw_len;
665 } else {
666 if (*res == NULL) {
667 if (may_free != NULL)
668 *res = may_free;
669 else
670 *res = xstrdup(real);
671 return (true);
672 }
673 *res1 = '\0';
674 if (may_free != NULL)
675 free(may_free);
676 if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) {
677 free(res);
678 return (false);
679 }
680 return (true);
681 }
682 }
683}
684
685static char *
686origin_subst(const char *real, const char *origin_path)
687{
688 char *res1, *res2, *res3, *res4;
689
690 if (uts.sysname[0] == '\0') {
691 if (uname(&uts) != 0) {
692 _rtld_error("utsname failed: %d", errno);
693 return (NULL);
694 }
695 }
696 if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) ||
697 !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) ||
698 !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) ||
699 !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3))
700 return (NULL);
701 return (res4);
702}
703
704static void
705die(void)
706{
707 const char *msg = dlerror();
708
709 if (msg == NULL)
710 msg = "Fatal error";
711 errx(1, "%s", msg);
712}
713
714/*
715 * Process a shared object's DYNAMIC section, and save the important
716 * information in its Obj_Entry structure.
717 */
718static void
719digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
720 const Elf_Dyn **dyn_soname)
721{
722 const Elf_Dyn *dynp;
723 Needed_Entry **needed_tail = &obj->needed;
724 int plttype = DT_REL;
725
726 *dyn_rpath = NULL;
727 *dyn_soname = NULL;
728
729 obj->bind_now = false;
730 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
731 switch (dynp->d_tag) {
732
733 case DT_REL:
734 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
735 break;
736
737 case DT_RELSZ:
738 obj->relsize = dynp->d_un.d_val;
739 break;
740
741 case DT_RELENT:
742 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
743 break;
744
745 case DT_JMPREL:
746 obj->pltrel = (const Elf_Rel *)
747 (obj->relocbase + dynp->d_un.d_ptr);
748 break;
749
750 case DT_PLTRELSZ:
751 obj->pltrelsize = dynp->d_un.d_val;
752 break;
753
754 case DT_RELA:
755 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
756 break;
757
758 case DT_RELASZ:
759 obj->relasize = dynp->d_un.d_val;
760 break;
761
762 case DT_RELAENT:
763 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
764 break;
765
766 case DT_PLTREL:
767 plttype = dynp->d_un.d_val;
768 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
769 break;
770
771 case DT_SYMTAB:
772 obj->symtab = (const Elf_Sym *)
773 (obj->relocbase + dynp->d_un.d_ptr);
774 break;
775
776 case DT_SYMENT:
777 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
778 break;
779
780 case DT_STRTAB:
781 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
782 break;
783
784 case DT_STRSZ:
785 obj->strsize = dynp->d_un.d_val;
786 break;
787
788 case DT_VERNEED:
789 obj->verneed = (const Elf_Verneed *) (obj->relocbase +
790 dynp->d_un.d_val);
791 break;
792
793 case DT_VERNEEDNUM:
794 obj->verneednum = dynp->d_un.d_val;
795 break;
796
797 case DT_VERDEF:
798 obj->verdef = (const Elf_Verdef *) (obj->relocbase +
799 dynp->d_un.d_val);
800 break;
801
802 case DT_VERDEFNUM:
803 obj->verdefnum = dynp->d_un.d_val;
804 break;
805
806 case DT_VERSYM:
807 obj->versyms = (const Elf_Versym *)(obj->relocbase +
808 dynp->d_un.d_val);
809 break;
810
811 case DT_HASH:
812 {
813 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
814 (obj->relocbase + dynp->d_un.d_ptr);
815 obj->nbuckets = hashtab[0];
816 obj->nchains = hashtab[1];
817 obj->buckets = hashtab + 2;
818 obj->chains = obj->buckets + obj->nbuckets;
819 }
820 break;
821
822 case DT_NEEDED:
823 if (!obj->rtld) {
824 Needed_Entry *nep = NEW(Needed_Entry);
825 nep->name = dynp->d_un.d_val;
826 nep->obj = NULL;
827 nep->next = NULL;
828
829 *needed_tail = nep;
830 needed_tail = &nep->next;
831 }
832 break;
833
834 case DT_PLTGOT:
835 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
836 break;
837
838 case DT_TEXTREL:
839 obj->textrel = true;
840 break;
841
842 case DT_SYMBOLIC:
843 obj->symbolic = true;
844 break;
845
846 case DT_RPATH:
847 case DT_RUNPATH: /* XXX: process separately */
848 /*
849 * We have to wait until later to process this, because we
850 * might not have gotten the address of the string table yet.
851 */
852 *dyn_rpath = dynp;
853 break;
854
855 case DT_SONAME:
856 *dyn_soname = dynp;
857 break;
858
859 case DT_INIT:
860 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
861 break;
862
863 case DT_FINI:
864 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
865 break;
866
867 /*
868 * Don't process DT_DEBUG on MIPS as the dynamic section
869 * is mapped read-only. DT_MIPS_RLD_MAP is used instead.
870 */
871
872#ifndef __mips__
873 case DT_DEBUG:
874 /* XXX - not implemented yet */
875 if (!early)
876 dbg("Filling in DT_DEBUG entry");
877 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
878 break;
879#endif
880
881 case DT_FLAGS:
882 if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
883 obj->z_origin = true;
884 if (dynp->d_un.d_val & DF_SYMBOLIC)
885 obj->symbolic = true;
886 if (dynp->d_un.d_val & DF_TEXTREL)
887 obj->textrel = true;
888 if (dynp->d_un.d_val & DF_BIND_NOW)
889 obj->bind_now = true;
890 if (dynp->d_un.d_val & DF_STATIC_TLS)
891 ;
892 break;
893#ifdef __mips__
894 case DT_MIPS_LOCAL_GOTNO:
895 obj->local_gotno = dynp->d_un.d_val;
896 break;
897
898 case DT_MIPS_SYMTABNO:
899 obj->symtabno = dynp->d_un.d_val;
900 break;
901
902 case DT_MIPS_GOTSYM:
903 obj->gotsym = dynp->d_un.d_val;
904 break;
905
906 case DT_MIPS_RLD_MAP:
907#ifdef notyet
908 if (!early)
909 dbg("Filling in DT_DEBUG entry");
910 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
911#endif
912 break;
913#endif
914
915 case DT_FLAGS_1:
916 if (dynp->d_un.d_val & DF_1_NOOPEN)
917 obj->z_noopen = true;
918 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
919 obj->z_origin = true;
920 if (dynp->d_un.d_val & DF_1_GLOBAL)
921 /* XXX */;
922 if (dynp->d_un.d_val & DF_1_BIND_NOW)
923 obj->bind_now = true;
924 if (dynp->d_un.d_val & DF_1_NODELETE)
925 obj->z_nodelete = true;
926 break;
927
928 default:
929 if (!early) {
930 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
931 (long)dynp->d_tag);
932 }
933 break;
934 }
935 }
936
937 obj->traced = false;
938
939 if (plttype == DT_RELA) {
940 obj->pltrela = (const Elf_Rela *) obj->pltrel;
941 obj->pltrel = NULL;
942 obj->pltrelasize = obj->pltrelsize;
943 obj->pltrelsize = 0;
944 }
945}
946
947static void
948digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
949 const Elf_Dyn *dyn_soname)
950{
951
952 if (obj->z_origin && obj->origin_path == NULL) {
953 obj->origin_path = xmalloc(PATH_MAX);
954 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
955 die();
956 }
957
958 if (dyn_rpath != NULL) {
959 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
960 if (obj->z_origin)
961 obj->rpath = origin_subst(obj->rpath, obj->origin_path);
962 }
963
964 if (dyn_soname != NULL)
965 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
966}
967
968static void
969digest_dynamic(Obj_Entry *obj, int early)
970{
971 const Elf_Dyn *dyn_rpath;
972 const Elf_Dyn *dyn_soname;
973
974 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname);
975 digest_dynamic2(obj, dyn_rpath, dyn_soname);
976}
977
978/*
979 * Process a shared object's program header. This is used only for the
980 * main program, when the kernel has already loaded the main program
981 * into memory before calling the dynamic linker. It creates and
982 * returns an Obj_Entry structure.
983 */
984static Obj_Entry *
985digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
986{
987 Obj_Entry *obj;
988 const Elf_Phdr *phlimit = phdr + phnum;
989 const Elf_Phdr *ph;
990 int nsegs = 0;
991
992 obj = obj_new();
993 for (ph = phdr; ph < phlimit; ph++) {
994 if (ph->p_type != PT_PHDR)
995 continue;
996
997 obj->phdr = phdr;
998 obj->phsize = ph->p_memsz;
999 obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1000 break;
1001 }
1002
1003 for (ph = phdr; ph < phlimit; ph++) {
1004 switch (ph->p_type) {
1005
1006 case PT_INTERP:
1007 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
1008 break;
1009
1010 case PT_LOAD:
1011 if (nsegs == 0) { /* First load segment */
1012 obj->vaddrbase = trunc_page(ph->p_vaddr);
1013 obj->mapbase = obj->vaddrbase + obj->relocbase;
1014 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1015 obj->vaddrbase;
1016 } else { /* Last load segment */
1017 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1018 obj->vaddrbase;
1019 }
1020 nsegs++;
1021 break;
1022
1023 case PT_DYNAMIC:
1024 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
1025 break;
1026
1027 case PT_TLS:
1028 obj->tlsindex = 1;
1029 obj->tlssize = ph->p_memsz;
1030 obj->tlsalign = ph->p_align;
1031 obj->tlsinitsize = ph->p_filesz;
1032 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
1033 break;
1034 }
1035 }
1036 if (nsegs < 1) {
1037 _rtld_error("%s: too few PT_LOAD segments", path);
1038 return NULL;
1039 }
1040
1041 obj->entry = entry;
1042 return obj;
1043}
1044
1045static Obj_Entry *
1046dlcheck(void *handle)
1047{
1048 Obj_Entry *obj;
1049
1050 for (obj = obj_list; obj != NULL; obj = obj->next)
1051 if (obj == (Obj_Entry *) handle)
1052 break;
1053
1054 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1055 _rtld_error("Invalid shared object handle %p", handle);
1056 return NULL;
1057 }
1058 return obj;
1059}
1060
1061/*
1062 * If the given object is already in the donelist, return true. Otherwise
1063 * add the object to the list and return false.
1064 */
1065static bool
1066donelist_check(DoneList *dlp, const Obj_Entry *obj)
1067{
1068 unsigned int i;
1069
1070 for (i = 0; i < dlp->num_used; i++)
1071 if (dlp->objs[i] == obj)
1072 return true;
1073 /*
1074 * Our donelist allocation should always be sufficient. But if
1075 * our threads locking isn't working properly, more shared objects
1076 * could have been loaded since we allocated the list. That should
1077 * never happen, but we'll handle it properly just in case it does.
1078 */
1079 if (dlp->num_used < dlp->num_alloc)
1080 dlp->objs[dlp->num_used++] = obj;
1081 return false;
1082}
1083
1084/*
1085 * Hash function for symbol table lookup. Don't even think about changing
1086 * this. It is specified by the System V ABI.
1087 */
1088unsigned long
1089elf_hash(const char *name)
1090{
1091 const unsigned char *p = (const unsigned char *) name;
1092 unsigned long h = 0;
1093 unsigned long g;
1094
1095 while (*p != '\0') {
1096 h = (h << 4) + *p++;
1097 if ((g = h & 0xf0000000) != 0)
1098 h ^= g >> 24;
1099 h &= ~g;
1100 }
1101 return h;
1102}
1103
1104/*
1105 * Find the library with the given name, and return its full pathname.
1106 * The returned string is dynamically allocated. Generates an error
1107 * message and returns NULL if the library cannot be found.
1108 *
1109 * If the second argument is non-NULL, then it refers to an already-
1110 * loaded shared object, whose library search path will be searched.
1111 *
1112 * The search order is:
1113 * LD_LIBRARY_PATH
1114 * rpath in the referencing file
1115 * ldconfig hints
1116 * /lib:/usr/lib
1117 */
1118static char *
1119find_library(const char *xname, const Obj_Entry *refobj)
1120{
1121 char *pathname;
1122 char *name;
1123
1124 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
1125 if (xname[0] != '/' && !trust) {
1126 _rtld_error("Absolute pathname required for shared object \"%s\"",
1127 xname);
1128 return NULL;
1129 }
1130 if (refobj != NULL && refobj->z_origin)
1131 return origin_subst(xname, refobj->origin_path);
1132 else
1133 return xstrdup(xname);
1134 }
1135
1136 if (libmap_disable || (refobj == NULL) ||
1137 (name = lm_find(refobj->path, xname)) == NULL)
1138 name = (char *)xname;
1139
1140 dbg(" Searching for \"%s\"", name);
1141
1142 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1143 (refobj != NULL &&
1144 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1145 (pathname = search_library_path(name, gethints())) != NULL ||
1146 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1147 return pathname;
1148
1149 if(refobj != NULL && refobj->path != NULL) {
1150 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1151 name, basename(refobj->path));
1152 } else {
1153 _rtld_error("Shared object \"%s\" not found", name);
1154 }
1155 return NULL;
1156}
1157
1158/*
1159 * Given a symbol number in a referencing object, find the corresponding
1160 * definition of the symbol. Returns a pointer to the symbol, or NULL if
1161 * no definition was found. Returns a pointer to the Obj_Entry of the
1162 * defining object via the reference parameter DEFOBJ_OUT.
1163 */
1164const Elf_Sym *
1165find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1166 const Obj_Entry **defobj_out, int flags, SymCache *cache)
1167{
1168 const Elf_Sym *ref;
1169 const Elf_Sym *def;
1170 const Obj_Entry *defobj;
1171 const Ver_Entry *ventry;
1172 const char *name;
1173 unsigned long hash;
1174
1175 /*
1176 * If we have already found this symbol, get the information from
1177 * the cache.
1178 */
1179 if (symnum >= refobj->nchains)
1180 return NULL; /* Bad object */
1181 if (cache != NULL && cache[symnum].sym != NULL) {
1182 *defobj_out = cache[symnum].obj;
1183 return cache[symnum].sym;
1184 }
1185
1186 ref = refobj->symtab + symnum;
1187 name = refobj->strtab + ref->st_name;
1188 defobj = NULL;
1189
1190 /*
1191 * We don't have to do a full scale lookup if the symbol is local.
1192 * We know it will bind to the instance in this load module; to
1193 * which we already have a pointer (ie ref). By not doing a lookup,
1194 * we not only improve performance, but it also avoids unresolvable
1195 * symbols when local symbols are not in the hash table. This has
1196 * been seen with the ia64 toolchain.
1197 */
1198 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1199 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
1200 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1201 symnum);
1202 }
1203 ventry = fetch_ventry(refobj, symnum);
1204 hash = elf_hash(name);
1205 def = symlook_default(name, hash, refobj, &defobj, ventry, flags);
1206 } else {
1207 def = ref;
1208 defobj = refobj;
1209 }
1210
1211 /*
1212 * If we found no definition and the reference is weak, treat the
1213 * symbol as having the value zero.
1214 */
1215 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1216 def = &sym_zero;
1217 defobj = obj_main;
1218 }
1219
1220 if (def != NULL) {
1221 *defobj_out = defobj;
1222 /* Record the information in the cache to avoid subsequent lookups. */
1223 if (cache != NULL) {
1224 cache[symnum].sym = def;
1225 cache[symnum].obj = defobj;
1226 }
1227 } else {
1228 if (refobj != &obj_rtld)
1229 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1230 }
1231 return def;
1232}
1233
1234/*
1235 * Return the search path from the ldconfig hints file, reading it if
1236 * necessary. Returns NULL if there are problems with the hints file,
1237 * or if the search path there is empty.
1238 */
1239static const char *
1240gethints(void)
1241{
1242 static char *hints;
1243
1244 if (hints == NULL) {
1245 int fd;
1246 struct elfhints_hdr hdr;
1247 char *p;
1248
1249 /* Keep from trying again in case the hints file is bad. */
1250 hints = "";
1251
1252 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1)
1253 return NULL;
1254 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1255 hdr.magic != ELFHINTS_MAGIC ||
1256 hdr.version != 1) {
1257 close(fd);
1258 return NULL;
1259 }
1260 p = xmalloc(hdr.dirlistlen + 1);
1261 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1262 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) {
1263 free(p);
1264 close(fd);
1265 return NULL;
1266 }
1267 hints = p;
1268 close(fd);
1269 }
1270 return hints[0] != '\0' ? hints : NULL;
1271}
1272
1273static void
1274init_dag(Obj_Entry *root)
1275{
1276 DoneList donelist;
1277
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/mount.h>
41#include <sys/mman.h>
42#include <sys/stat.h>
43#include <sys/sysctl.h>
44#include <sys/uio.h>
45#include <sys/utsname.h>
46#include <sys/ktrace.h>
47
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#include "libmap.h"
61#include "rtld_tls.h"
62
63#ifndef COMPAT_32BIT
64#define PATH_RTLD "/libexec/ld-elf.so.1"
65#else
66#define PATH_RTLD "/libexec/ld-elf32.so.1"
67#endif
68
69/* Types. */
70typedef void (*func_ptr_type)();
71typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
72
73/*
74 * This structure provides a reentrant way to keep a list of objects and
75 * check which ones have already been processed in some way.
76 */
77typedef struct Struct_DoneList {
78 const Obj_Entry **objs; /* Array of object pointers */
79 unsigned int num_alloc; /* Allocated size of the array */
80 unsigned int num_used; /* Number of array slots used */
81} DoneList;
82
83/*
84 * Function declarations.
85 */
86static const char *basename(const char *);
87static void die(void) __dead2;
88static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
89 const Elf_Dyn **);
90static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *);
91static void digest_dynamic(Obj_Entry *, int);
92static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
93static Obj_Entry *dlcheck(void *);
94static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
95static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
96static bool donelist_check(DoneList *, const Obj_Entry *);
97static void errmsg_restore(char *);
98static char *errmsg_save(void);
99static void *fill_search_info(const char *, size_t, void *);
100static char *find_library(const char *, const Obj_Entry *);
101static const char *gethints(void);
102static void init_dag(Obj_Entry *);
103static void init_dag1(Obj_Entry *, Obj_Entry *, DoneList *);
104static void init_rtld(caddr_t, Elf_Auxinfo **);
105static void initlist_add_neededs(Needed_Entry *, Objlist *);
106static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
107static void linkmap_add(Obj_Entry *);
108static void linkmap_delete(Obj_Entry *);
109static int load_needed_objects(Obj_Entry *, int);
110static int load_preload_objects(void);
111static Obj_Entry *load_object(const char *, const Obj_Entry *, int);
112static Obj_Entry *obj_from_addr(const void *);
113static void objlist_call_fini(Objlist *, bool, int *);
114static void objlist_call_init(Objlist *, int *);
115static void objlist_clear(Objlist *);
116static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
117static void objlist_init(Objlist *);
118static void objlist_push_head(Objlist *, Obj_Entry *);
119static void objlist_push_tail(Objlist *, Obj_Entry *);
120static void objlist_remove(Objlist *, Obj_Entry *);
121static void *path_enumerate(const char *, path_enum_proc, void *);
122static int relocate_objects(Obj_Entry *, bool, Obj_Entry *);
123static int rtld_dirname(const char *, char *);
124static int rtld_dirname_abs(const char *, char *);
125static void rtld_exit(void);
126static char *search_library_path(const char *, const char *);
127static const void **get_program_var_addr(const char *);
128static void set_program_var(const char *, const void *);
129static const Elf_Sym *symlook_default(const char *, unsigned long,
130 const Obj_Entry *, const Obj_Entry **, const Ver_Entry *, int);
131static const Elf_Sym *symlook_list(const char *, unsigned long, const Objlist *,
132 const Obj_Entry **, const Ver_Entry *, int, DoneList *);
133static const Elf_Sym *symlook_needed(const char *, unsigned long,
134 const Needed_Entry *, const Obj_Entry **, const Ver_Entry *,
135 int, DoneList *);
136static void trace_loaded_objects(Obj_Entry *);
137static void unlink_object(Obj_Entry *);
138static void unload_object(Obj_Entry *);
139static void unref_dag(Obj_Entry *);
140static void ref_dag(Obj_Entry *);
141static int origin_subst_one(char **, const char *, const char *,
142 const char *, char *);
143static char *origin_subst(const char *, const char *);
144static int rtld_verify_versions(const Objlist *);
145static int rtld_verify_object_versions(Obj_Entry *);
146static void object_add_name(Obj_Entry *, const char *);
147static int object_match_name(const Obj_Entry *, const char *);
148static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
149static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
150 struct dl_phdr_info *phdr_info);
151
152void r_debug_state(struct r_debug *, struct link_map *);
153
154/*
155 * Data declarations.
156 */
157static char *error_message; /* Message for dlerror(), or NULL */
158struct r_debug r_debug; /* for GDB; */
159static bool libmap_disable; /* Disable libmap */
160static char *libmap_override; /* Maps to use in addition to libmap.conf */
161static bool trust; /* False for setuid and setgid programs */
162static bool dangerous_ld_env; /* True if environment variables have been
163 used to affect the libraries loaded */
164static char *ld_bind_now; /* Environment variable for immediate binding */
165static char *ld_debug; /* Environment variable for debugging */
166static char *ld_library_path; /* Environment variable for search path */
167static char *ld_preload; /* Environment variable for libraries to
168 load first */
169static char *ld_elf_hints_path; /* Environment variable for alternative hints path */
170static char *ld_tracing; /* Called from ldd to print libs */
171static char *ld_utrace; /* Use utrace() to log events. */
172static Obj_Entry *obj_list; /* Head of linked list of shared objects */
173static Obj_Entry **obj_tail; /* Link field of last object in list */
174static Obj_Entry *obj_main; /* The main program shared object */
175static Obj_Entry obj_rtld; /* The dynamic linker shared object */
176static unsigned int obj_count; /* Number of objects in obj_list */
177static unsigned int obj_loads; /* Number of objects in obj_list */
178
179static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
180 STAILQ_HEAD_INITIALIZER(list_global);
181static Objlist list_main = /* Objects loaded at program startup */
182 STAILQ_HEAD_INITIALIZER(list_main);
183static Objlist list_fini = /* Objects needing fini() calls */
184 STAILQ_HEAD_INITIALIZER(list_fini);
185
186Elf_Sym sym_zero; /* For resolving undefined weak refs. */
187
188#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
189
190extern Elf_Dyn _DYNAMIC;
191#pragma weak _DYNAMIC
192#ifndef RTLD_IS_DYNAMIC
193#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL)
194#endif
195
196int osreldate, pagesize;
197
198/*
199 * Global declarations normally provided by crt1. The dynamic linker is
200 * not built with crt1, so we have to provide them ourselves.
201 */
202char *__progname;
203char **environ;
204
205/*
206 * Globals to control TLS allocation.
207 */
208size_t tls_last_offset; /* Static TLS offset of last module */
209size_t tls_last_size; /* Static TLS size of last module */
210size_t tls_static_space; /* Static TLS space allocated */
211int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
212int tls_max_index = 1; /* Largest module index allocated */
213
214/*
215 * Fill in a DoneList with an allocation large enough to hold all of
216 * the currently-loaded objects. Keep this as a macro since it calls
217 * alloca and we want that to occur within the scope of the caller.
218 */
219#define donelist_init(dlp) \
220 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
221 assert((dlp)->objs != NULL), \
222 (dlp)->num_alloc = obj_count, \
223 (dlp)->num_used = 0)
224
225#define UTRACE_DLOPEN_START 1
226#define UTRACE_DLOPEN_STOP 2
227#define UTRACE_DLCLOSE_START 3
228#define UTRACE_DLCLOSE_STOP 4
229#define UTRACE_LOAD_OBJECT 5
230#define UTRACE_UNLOAD_OBJECT 6
231#define UTRACE_ADD_RUNDEP 7
232#define UTRACE_PRELOAD_FINISHED 8
233#define UTRACE_INIT_CALL 9
234#define UTRACE_FINI_CALL 10
235
236struct utrace_rtld {
237 char sig[4]; /* 'RTLD' */
238 int event;
239 void *handle;
240 void *mapbase; /* Used for 'parent' and 'init/fini' */
241 size_t mapsize;
242 int refcnt; /* Used for 'mode' */
243 char name[MAXPATHLEN];
244};
245
246#define LD_UTRACE(e, h, mb, ms, r, n) do { \
247 if (ld_utrace != NULL) \
248 ld_utrace_log(e, h, mb, ms, r, n); \
249} while (0)
250
251static void
252ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
253 int refcnt, const char *name)
254{
255 struct utrace_rtld ut;
256
257 ut.sig[0] = 'R';
258 ut.sig[1] = 'T';
259 ut.sig[2] = 'L';
260 ut.sig[3] = 'D';
261 ut.event = event;
262 ut.handle = handle;
263 ut.mapbase = mapbase;
264 ut.mapsize = mapsize;
265 ut.refcnt = refcnt;
266 bzero(ut.name, sizeof(ut.name));
267 if (name)
268 strlcpy(ut.name, name, sizeof(ut.name));
269 utrace(&ut, sizeof(ut));
270}
271
272/*
273 * Main entry point for dynamic linking. The first argument is the
274 * stack pointer. The stack is expected to be laid out as described
275 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
276 * Specifically, the stack pointer points to a word containing
277 * ARGC. Following that in the stack is a null-terminated sequence
278 * of pointers to argument strings. Then comes a null-terminated
279 * sequence of pointers to environment strings. Finally, there is a
280 * sequence of "auxiliary vector" entries.
281 *
282 * The second argument points to a place to store the dynamic linker's
283 * exit procedure pointer and the third to a place to store the main
284 * program's object.
285 *
286 * The return value is the main program's entry point.
287 */
288func_ptr_type
289_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
290{
291 Elf_Auxinfo *aux_info[AT_COUNT];
292 int i;
293 int argc;
294 char **argv;
295 char **env;
296 Elf_Auxinfo *aux;
297 Elf_Auxinfo *auxp;
298 const char *argv0;
299 Objlist_Entry *entry;
300 Obj_Entry *obj;
301 Obj_Entry **preload_tail;
302 Objlist initlist;
303 int lockstate;
304
305 /*
306 * On entry, the dynamic linker itself has not been relocated yet.
307 * Be very careful not to reference any global data until after
308 * init_rtld has returned. It is OK to reference file-scope statics
309 * and string constants, and to call static and global functions.
310 */
311
312 /* Find the auxiliary vector on the stack. */
313 argc = *sp++;
314 argv = (char **) sp;
315 sp += argc + 1; /* Skip over arguments and NULL terminator */
316 env = (char **) sp;
317 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
318 ;
319 aux = (Elf_Auxinfo *) sp;
320
321 /* Digest the auxiliary vector. */
322 for (i = 0; i < AT_COUNT; i++)
323 aux_info[i] = NULL;
324 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
325 if (auxp->a_type < AT_COUNT)
326 aux_info[auxp->a_type] = auxp;
327 }
328
329 /* Initialize and relocate ourselves. */
330 assert(aux_info[AT_BASE] != NULL);
331 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
332
333 __progname = obj_rtld.path;
334 argv0 = argv[0] != NULL ? argv[0] : "(null)";
335 environ = env;
336
337 trust = !issetugid();
338
339 ld_bind_now = getenv(LD_ "BIND_NOW");
340 /*
341 * If the process is tainted, then we un-set the dangerous environment
342 * variables. The process will be marked as tainted until setuid(2)
343 * is called. If any child process calls setuid(2) we do not want any
344 * future processes to honor the potentially un-safe variables.
345 */
346 if (!trust) {
347 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") ||
348 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") ||
349 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH")) {
350 _rtld_error("environment corrupt; aborting");
351 die();
352 }
353 }
354 ld_debug = getenv(LD_ "DEBUG");
355 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL;
356 libmap_override = getenv(LD_ "LIBMAP");
357 ld_library_path = getenv(LD_ "LIBRARY_PATH");
358 ld_preload = getenv(LD_ "PRELOAD");
359 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH");
360 dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
361 (ld_library_path != NULL) || (ld_preload != NULL) ||
362 (ld_elf_hints_path != NULL);
363 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS");
364 ld_utrace = getenv(LD_ "UTRACE");
365
366 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
367 ld_elf_hints_path = _PATH_ELF_HINTS;
368
369 if (ld_debug != NULL && *ld_debug != '\0')
370 debug = 1;
371 dbg("%s is initialized, base address = %p", __progname,
372 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
373 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
374 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
375
376 /*
377 * Load the main program, or process its program header if it is
378 * already loaded.
379 */
380 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
381 int fd = aux_info[AT_EXECFD]->a_un.a_val;
382 dbg("loading main program");
383 obj_main = map_object(fd, argv0, NULL);
384 close(fd);
385 if (obj_main == NULL)
386 die();
387 } else { /* Main program already loaded. */
388 const Elf_Phdr *phdr;
389 int phnum;
390 caddr_t entry;
391
392 dbg("processing main program's program header");
393 assert(aux_info[AT_PHDR] != NULL);
394 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
395 assert(aux_info[AT_PHNUM] != NULL);
396 phnum = aux_info[AT_PHNUM]->a_un.a_val;
397 assert(aux_info[AT_PHENT] != NULL);
398 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
399 assert(aux_info[AT_ENTRY] != NULL);
400 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
401 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
402 die();
403 }
404
405 if (aux_info[AT_EXECPATH] != 0) {
406 char *kexecpath;
407 char buf[MAXPATHLEN];
408
409 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
410 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
411 if (kexecpath[0] == '/')
412 obj_main->path = kexecpath;
413 else if (getcwd(buf, sizeof(buf)) == NULL ||
414 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
415 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
416 obj_main->path = xstrdup(argv0);
417 else
418 obj_main->path = xstrdup(buf);
419 } else {
420 dbg("No AT_EXECPATH");
421 obj_main->path = xstrdup(argv0);
422 }
423 dbg("obj_main path %s", obj_main->path);
424 obj_main->mainprog = true;
425
426 /*
427 * Get the actual dynamic linker pathname from the executable if
428 * possible. (It should always be possible.) That ensures that
429 * gdb will find the right dynamic linker even if a non-standard
430 * one is being used.
431 */
432 if (obj_main->interp != NULL &&
433 strcmp(obj_main->interp, obj_rtld.path) != 0) {
434 free(obj_rtld.path);
435 obj_rtld.path = xstrdup(obj_main->interp);
436 __progname = obj_rtld.path;
437 }
438
439 digest_dynamic(obj_main, 0);
440
441 linkmap_add(obj_main);
442 linkmap_add(&obj_rtld);
443
444 /* Link the main program into the list of objects. */
445 *obj_tail = obj_main;
446 obj_tail = &obj_main->next;
447 obj_count++;
448 obj_loads++;
449 /* Make sure we don't call the main program's init and fini functions. */
450 obj_main->init = obj_main->fini = (Elf_Addr)NULL;
451
452 /* Initialize a fake symbol for resolving undefined weak references. */
453 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
454 sym_zero.st_shndx = SHN_UNDEF;
455 sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
456
457 if (!libmap_disable)
458 libmap_disable = (bool)lm_init(libmap_override);
459
460 dbg("loading LD_PRELOAD libraries");
461 if (load_preload_objects() == -1)
462 die();
463 preload_tail = obj_tail;
464
465 dbg("loading needed objects");
466 if (load_needed_objects(obj_main, 0) == -1)
467 die();
468
469 /* Make a list of all objects loaded at startup. */
470 for (obj = obj_list; obj != NULL; obj = obj->next) {
471 objlist_push_tail(&list_main, obj);
472 obj->refcount++;
473 }
474
475 dbg("checking for required versions");
476 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
477 die();
478
479 if (ld_tracing) { /* We're done */
480 trace_loaded_objects(obj_main);
481 exit(0);
482 }
483
484 if (getenv(LD_ "DUMP_REL_PRE") != NULL) {
485 dump_relocations(obj_main);
486 exit (0);
487 }
488
489 /* setup TLS for main thread */
490 dbg("initializing initial thread local storage");
491 STAILQ_FOREACH(entry, &list_main, link) {
492 /*
493 * Allocate all the initial objects out of the static TLS
494 * block even if they didn't ask for it.
495 */
496 allocate_tls_offset(entry->obj);
497 }
498 allocate_initial_tls(obj_list);
499
500 if (relocate_objects(obj_main,
501 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
502 die();
503
504 dbg("doing copy relocations");
505 if (do_copy_relocations(obj_main) == -1)
506 die();
507
508 if (getenv(LD_ "DUMP_REL_POST") != NULL) {
509 dump_relocations(obj_main);
510 exit (0);
511 }
512
513 dbg("initializing key program variables");
514 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
515 set_program_var("environ", env);
516 set_program_var("__elf_aux_vector", aux);
517
518 dbg("initializing thread locks");
519 lockdflt_init();
520
521 /* Make a list of init functions to call. */
522 objlist_init(&initlist);
523 initlist_add_objects(obj_list, preload_tail, &initlist);
524
525 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
526
527 lockstate = wlock_acquire(rtld_bind_lock);
528 objlist_call_init(&initlist, &lockstate);
529 objlist_clear(&initlist);
530 wlock_release(rtld_bind_lock, lockstate);
531
532 dbg("transferring control to program entry point = %p", obj_main->entry);
533
534 /* Return the exit procedure and the program entry point. */
535 *exit_proc = rtld_exit;
536 *objp = obj_main;
537 return (func_ptr_type) obj_main->entry;
538}
539
540Elf_Addr
541_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
542{
543 const Elf_Rel *rel;
544 const Elf_Sym *def;
545 const Obj_Entry *defobj;
546 Elf_Addr *where;
547 Elf_Addr target;
548 int lockstate;
549
550 lockstate = rlock_acquire(rtld_bind_lock);
551 if (obj->pltrel)
552 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
553 else
554 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
555
556 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
557 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
558 if (def == NULL)
559 die();
560
561 target = (Elf_Addr)(defobj->relocbase + def->st_value);
562
563 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
564 defobj->strtab + def->st_name, basename(obj->path),
565 (void *)target, basename(defobj->path));
566
567 /*
568 * Write the new contents for the jmpslot. Note that depending on
569 * architecture, the value which we need to return back to the
570 * lazy binding trampoline may or may not be the target
571 * address. The value returned from reloc_jmpslot() is the value
572 * that the trampoline needs.
573 */
574 target = reloc_jmpslot(where, target, defobj, obj, rel);
575 rlock_release(rtld_bind_lock, lockstate);
576 return target;
577}
578
579/*
580 * Error reporting function. Use it like printf. If formats the message
581 * into a buffer, and sets things up so that the next call to dlerror()
582 * will return the message.
583 */
584void
585_rtld_error(const char *fmt, ...)
586{
587 static char buf[512];
588 va_list ap;
589
590 va_start(ap, fmt);
591 vsnprintf(buf, sizeof buf, fmt, ap);
592 error_message = buf;
593 va_end(ap);
594}
595
596/*
597 * Return a dynamically-allocated copy of the current error message, if any.
598 */
599static char *
600errmsg_save(void)
601{
602 return error_message == NULL ? NULL : xstrdup(error_message);
603}
604
605/*
606 * Restore the current error message from a copy which was previously saved
607 * by errmsg_save(). The copy is freed.
608 */
609static void
610errmsg_restore(char *saved_msg)
611{
612 if (saved_msg == NULL)
613 error_message = NULL;
614 else {
615 _rtld_error("%s", saved_msg);
616 free(saved_msg);
617 }
618}
619
620static const char *
621basename(const char *name)
622{
623 const char *p = strrchr(name, '/');
624 return p != NULL ? p + 1 : name;
625}
626
627static struct utsname uts;
628
629static int
630origin_subst_one(char **res, const char *real, const char *kw, const char *subst,
631 char *may_free)
632{
633 const char *p, *p1;
634 char *res1;
635 int subst_len;
636 int kw_len;
637
638 res1 = *res = NULL;
639 p = real;
640 subst_len = kw_len = 0;
641 for (;;) {
642 p1 = strstr(p, kw);
643 if (p1 != NULL) {
644 if (subst_len == 0) {
645 subst_len = strlen(subst);
646 kw_len = strlen(kw);
647 }
648 if (*res == NULL) {
649 *res = xmalloc(PATH_MAX);
650 res1 = *res;
651 }
652 if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) {
653 _rtld_error("Substitution of %s in %s cannot be performed",
654 kw, real);
655 if (may_free != NULL)
656 free(may_free);
657 free(res);
658 return (false);
659 }
660 memcpy(res1, p, p1 - p);
661 res1 += p1 - p;
662 memcpy(res1, subst, subst_len);
663 res1 += subst_len;
664 p = p1 + kw_len;
665 } else {
666 if (*res == NULL) {
667 if (may_free != NULL)
668 *res = may_free;
669 else
670 *res = xstrdup(real);
671 return (true);
672 }
673 *res1 = '\0';
674 if (may_free != NULL)
675 free(may_free);
676 if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) {
677 free(res);
678 return (false);
679 }
680 return (true);
681 }
682 }
683}
684
685static char *
686origin_subst(const char *real, const char *origin_path)
687{
688 char *res1, *res2, *res3, *res4;
689
690 if (uts.sysname[0] == '\0') {
691 if (uname(&uts) != 0) {
692 _rtld_error("utsname failed: %d", errno);
693 return (NULL);
694 }
695 }
696 if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) ||
697 !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) ||
698 !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) ||
699 !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3))
700 return (NULL);
701 return (res4);
702}
703
704static void
705die(void)
706{
707 const char *msg = dlerror();
708
709 if (msg == NULL)
710 msg = "Fatal error";
711 errx(1, "%s", msg);
712}
713
714/*
715 * Process a shared object's DYNAMIC section, and save the important
716 * information in its Obj_Entry structure.
717 */
718static void
719digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
720 const Elf_Dyn **dyn_soname)
721{
722 const Elf_Dyn *dynp;
723 Needed_Entry **needed_tail = &obj->needed;
724 int plttype = DT_REL;
725
726 *dyn_rpath = NULL;
727 *dyn_soname = NULL;
728
729 obj->bind_now = false;
730 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
731 switch (dynp->d_tag) {
732
733 case DT_REL:
734 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
735 break;
736
737 case DT_RELSZ:
738 obj->relsize = dynp->d_un.d_val;
739 break;
740
741 case DT_RELENT:
742 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
743 break;
744
745 case DT_JMPREL:
746 obj->pltrel = (const Elf_Rel *)
747 (obj->relocbase + dynp->d_un.d_ptr);
748 break;
749
750 case DT_PLTRELSZ:
751 obj->pltrelsize = dynp->d_un.d_val;
752 break;
753
754 case DT_RELA:
755 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
756 break;
757
758 case DT_RELASZ:
759 obj->relasize = dynp->d_un.d_val;
760 break;
761
762 case DT_RELAENT:
763 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
764 break;
765
766 case DT_PLTREL:
767 plttype = dynp->d_un.d_val;
768 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
769 break;
770
771 case DT_SYMTAB:
772 obj->symtab = (const Elf_Sym *)
773 (obj->relocbase + dynp->d_un.d_ptr);
774 break;
775
776 case DT_SYMENT:
777 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
778 break;
779
780 case DT_STRTAB:
781 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
782 break;
783
784 case DT_STRSZ:
785 obj->strsize = dynp->d_un.d_val;
786 break;
787
788 case DT_VERNEED:
789 obj->verneed = (const Elf_Verneed *) (obj->relocbase +
790 dynp->d_un.d_val);
791 break;
792
793 case DT_VERNEEDNUM:
794 obj->verneednum = dynp->d_un.d_val;
795 break;
796
797 case DT_VERDEF:
798 obj->verdef = (const Elf_Verdef *) (obj->relocbase +
799 dynp->d_un.d_val);
800 break;
801
802 case DT_VERDEFNUM:
803 obj->verdefnum = dynp->d_un.d_val;
804 break;
805
806 case DT_VERSYM:
807 obj->versyms = (const Elf_Versym *)(obj->relocbase +
808 dynp->d_un.d_val);
809 break;
810
811 case DT_HASH:
812 {
813 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
814 (obj->relocbase + dynp->d_un.d_ptr);
815 obj->nbuckets = hashtab[0];
816 obj->nchains = hashtab[1];
817 obj->buckets = hashtab + 2;
818 obj->chains = obj->buckets + obj->nbuckets;
819 }
820 break;
821
822 case DT_NEEDED:
823 if (!obj->rtld) {
824 Needed_Entry *nep = NEW(Needed_Entry);
825 nep->name = dynp->d_un.d_val;
826 nep->obj = NULL;
827 nep->next = NULL;
828
829 *needed_tail = nep;
830 needed_tail = &nep->next;
831 }
832 break;
833
834 case DT_PLTGOT:
835 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
836 break;
837
838 case DT_TEXTREL:
839 obj->textrel = true;
840 break;
841
842 case DT_SYMBOLIC:
843 obj->symbolic = true;
844 break;
845
846 case DT_RPATH:
847 case DT_RUNPATH: /* XXX: process separately */
848 /*
849 * We have to wait until later to process this, because we
850 * might not have gotten the address of the string table yet.
851 */
852 *dyn_rpath = dynp;
853 break;
854
855 case DT_SONAME:
856 *dyn_soname = dynp;
857 break;
858
859 case DT_INIT:
860 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
861 break;
862
863 case DT_FINI:
864 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
865 break;
866
867 /*
868 * Don't process DT_DEBUG on MIPS as the dynamic section
869 * is mapped read-only. DT_MIPS_RLD_MAP is used instead.
870 */
871
872#ifndef __mips__
873 case DT_DEBUG:
874 /* XXX - not implemented yet */
875 if (!early)
876 dbg("Filling in DT_DEBUG entry");
877 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
878 break;
879#endif
880
881 case DT_FLAGS:
882 if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
883 obj->z_origin = true;
884 if (dynp->d_un.d_val & DF_SYMBOLIC)
885 obj->symbolic = true;
886 if (dynp->d_un.d_val & DF_TEXTREL)
887 obj->textrel = true;
888 if (dynp->d_un.d_val & DF_BIND_NOW)
889 obj->bind_now = true;
890 if (dynp->d_un.d_val & DF_STATIC_TLS)
891 ;
892 break;
893#ifdef __mips__
894 case DT_MIPS_LOCAL_GOTNO:
895 obj->local_gotno = dynp->d_un.d_val;
896 break;
897
898 case DT_MIPS_SYMTABNO:
899 obj->symtabno = dynp->d_un.d_val;
900 break;
901
902 case DT_MIPS_GOTSYM:
903 obj->gotsym = dynp->d_un.d_val;
904 break;
905
906 case DT_MIPS_RLD_MAP:
907#ifdef notyet
908 if (!early)
909 dbg("Filling in DT_DEBUG entry");
910 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
911#endif
912 break;
913#endif
914
915 case DT_FLAGS_1:
916 if (dynp->d_un.d_val & DF_1_NOOPEN)
917 obj->z_noopen = true;
918 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
919 obj->z_origin = true;
920 if (dynp->d_un.d_val & DF_1_GLOBAL)
921 /* XXX */;
922 if (dynp->d_un.d_val & DF_1_BIND_NOW)
923 obj->bind_now = true;
924 if (dynp->d_un.d_val & DF_1_NODELETE)
925 obj->z_nodelete = true;
926 break;
927
928 default:
929 if (!early) {
930 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
931 (long)dynp->d_tag);
932 }
933 break;
934 }
935 }
936
937 obj->traced = false;
938
939 if (plttype == DT_RELA) {
940 obj->pltrela = (const Elf_Rela *) obj->pltrel;
941 obj->pltrel = NULL;
942 obj->pltrelasize = obj->pltrelsize;
943 obj->pltrelsize = 0;
944 }
945}
946
947static void
948digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
949 const Elf_Dyn *dyn_soname)
950{
951
952 if (obj->z_origin && obj->origin_path == NULL) {
953 obj->origin_path = xmalloc(PATH_MAX);
954 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
955 die();
956 }
957
958 if (dyn_rpath != NULL) {
959 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
960 if (obj->z_origin)
961 obj->rpath = origin_subst(obj->rpath, obj->origin_path);
962 }
963
964 if (dyn_soname != NULL)
965 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
966}
967
968static void
969digest_dynamic(Obj_Entry *obj, int early)
970{
971 const Elf_Dyn *dyn_rpath;
972 const Elf_Dyn *dyn_soname;
973
974 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname);
975 digest_dynamic2(obj, dyn_rpath, dyn_soname);
976}
977
978/*
979 * Process a shared object's program header. This is used only for the
980 * main program, when the kernel has already loaded the main program
981 * into memory before calling the dynamic linker. It creates and
982 * returns an Obj_Entry structure.
983 */
984static Obj_Entry *
985digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
986{
987 Obj_Entry *obj;
988 const Elf_Phdr *phlimit = phdr + phnum;
989 const Elf_Phdr *ph;
990 int nsegs = 0;
991
992 obj = obj_new();
993 for (ph = phdr; ph < phlimit; ph++) {
994 if (ph->p_type != PT_PHDR)
995 continue;
996
997 obj->phdr = phdr;
998 obj->phsize = ph->p_memsz;
999 obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1000 break;
1001 }
1002
1003 for (ph = phdr; ph < phlimit; ph++) {
1004 switch (ph->p_type) {
1005
1006 case PT_INTERP:
1007 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
1008 break;
1009
1010 case PT_LOAD:
1011 if (nsegs == 0) { /* First load segment */
1012 obj->vaddrbase = trunc_page(ph->p_vaddr);
1013 obj->mapbase = obj->vaddrbase + obj->relocbase;
1014 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1015 obj->vaddrbase;
1016 } else { /* Last load segment */
1017 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1018 obj->vaddrbase;
1019 }
1020 nsegs++;
1021 break;
1022
1023 case PT_DYNAMIC:
1024 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
1025 break;
1026
1027 case PT_TLS:
1028 obj->tlsindex = 1;
1029 obj->tlssize = ph->p_memsz;
1030 obj->tlsalign = ph->p_align;
1031 obj->tlsinitsize = ph->p_filesz;
1032 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
1033 break;
1034 }
1035 }
1036 if (nsegs < 1) {
1037 _rtld_error("%s: too few PT_LOAD segments", path);
1038 return NULL;
1039 }
1040
1041 obj->entry = entry;
1042 return obj;
1043}
1044
1045static Obj_Entry *
1046dlcheck(void *handle)
1047{
1048 Obj_Entry *obj;
1049
1050 for (obj = obj_list; obj != NULL; obj = obj->next)
1051 if (obj == (Obj_Entry *) handle)
1052 break;
1053
1054 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1055 _rtld_error("Invalid shared object handle %p", handle);
1056 return NULL;
1057 }
1058 return obj;
1059}
1060
1061/*
1062 * If the given object is already in the donelist, return true. Otherwise
1063 * add the object to the list and return false.
1064 */
1065static bool
1066donelist_check(DoneList *dlp, const Obj_Entry *obj)
1067{
1068 unsigned int i;
1069
1070 for (i = 0; i < dlp->num_used; i++)
1071 if (dlp->objs[i] == obj)
1072 return true;
1073 /*
1074 * Our donelist allocation should always be sufficient. But if
1075 * our threads locking isn't working properly, more shared objects
1076 * could have been loaded since we allocated the list. That should
1077 * never happen, but we'll handle it properly just in case it does.
1078 */
1079 if (dlp->num_used < dlp->num_alloc)
1080 dlp->objs[dlp->num_used++] = obj;
1081 return false;
1082}
1083
1084/*
1085 * Hash function for symbol table lookup. Don't even think about changing
1086 * this. It is specified by the System V ABI.
1087 */
1088unsigned long
1089elf_hash(const char *name)
1090{
1091 const unsigned char *p = (const unsigned char *) name;
1092 unsigned long h = 0;
1093 unsigned long g;
1094
1095 while (*p != '\0') {
1096 h = (h << 4) + *p++;
1097 if ((g = h & 0xf0000000) != 0)
1098 h ^= g >> 24;
1099 h &= ~g;
1100 }
1101 return h;
1102}
1103
1104/*
1105 * Find the library with the given name, and return its full pathname.
1106 * The returned string is dynamically allocated. Generates an error
1107 * message and returns NULL if the library cannot be found.
1108 *
1109 * If the second argument is non-NULL, then it refers to an already-
1110 * loaded shared object, whose library search path will be searched.
1111 *
1112 * The search order is:
1113 * LD_LIBRARY_PATH
1114 * rpath in the referencing file
1115 * ldconfig hints
1116 * /lib:/usr/lib
1117 */
1118static char *
1119find_library(const char *xname, const Obj_Entry *refobj)
1120{
1121 char *pathname;
1122 char *name;
1123
1124 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
1125 if (xname[0] != '/' && !trust) {
1126 _rtld_error("Absolute pathname required for shared object \"%s\"",
1127 xname);
1128 return NULL;
1129 }
1130 if (refobj != NULL && refobj->z_origin)
1131 return origin_subst(xname, refobj->origin_path);
1132 else
1133 return xstrdup(xname);
1134 }
1135
1136 if (libmap_disable || (refobj == NULL) ||
1137 (name = lm_find(refobj->path, xname)) == NULL)
1138 name = (char *)xname;
1139
1140 dbg(" Searching for \"%s\"", name);
1141
1142 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1143 (refobj != NULL &&
1144 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1145 (pathname = search_library_path(name, gethints())) != NULL ||
1146 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1147 return pathname;
1148
1149 if(refobj != NULL && refobj->path != NULL) {
1150 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1151 name, basename(refobj->path));
1152 } else {
1153 _rtld_error("Shared object \"%s\" not found", name);
1154 }
1155 return NULL;
1156}
1157
1158/*
1159 * Given a symbol number in a referencing object, find the corresponding
1160 * definition of the symbol. Returns a pointer to the symbol, or NULL if
1161 * no definition was found. Returns a pointer to the Obj_Entry of the
1162 * defining object via the reference parameter DEFOBJ_OUT.
1163 */
1164const Elf_Sym *
1165find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1166 const Obj_Entry **defobj_out, int flags, SymCache *cache)
1167{
1168 const Elf_Sym *ref;
1169 const Elf_Sym *def;
1170 const Obj_Entry *defobj;
1171 const Ver_Entry *ventry;
1172 const char *name;
1173 unsigned long hash;
1174
1175 /*
1176 * If we have already found this symbol, get the information from
1177 * the cache.
1178 */
1179 if (symnum >= refobj->nchains)
1180 return NULL; /* Bad object */
1181 if (cache != NULL && cache[symnum].sym != NULL) {
1182 *defobj_out = cache[symnum].obj;
1183 return cache[symnum].sym;
1184 }
1185
1186 ref = refobj->symtab + symnum;
1187 name = refobj->strtab + ref->st_name;
1188 defobj = NULL;
1189
1190 /*
1191 * We don't have to do a full scale lookup if the symbol is local.
1192 * We know it will bind to the instance in this load module; to
1193 * which we already have a pointer (ie ref). By not doing a lookup,
1194 * we not only improve performance, but it also avoids unresolvable
1195 * symbols when local symbols are not in the hash table. This has
1196 * been seen with the ia64 toolchain.
1197 */
1198 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1199 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
1200 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1201 symnum);
1202 }
1203 ventry = fetch_ventry(refobj, symnum);
1204 hash = elf_hash(name);
1205 def = symlook_default(name, hash, refobj, &defobj, ventry, flags);
1206 } else {
1207 def = ref;
1208 defobj = refobj;
1209 }
1210
1211 /*
1212 * If we found no definition and the reference is weak, treat the
1213 * symbol as having the value zero.
1214 */
1215 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1216 def = &sym_zero;
1217 defobj = obj_main;
1218 }
1219
1220 if (def != NULL) {
1221 *defobj_out = defobj;
1222 /* Record the information in the cache to avoid subsequent lookups. */
1223 if (cache != NULL) {
1224 cache[symnum].sym = def;
1225 cache[symnum].obj = defobj;
1226 }
1227 } else {
1228 if (refobj != &obj_rtld)
1229 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1230 }
1231 return def;
1232}
1233
1234/*
1235 * Return the search path from the ldconfig hints file, reading it if
1236 * necessary. Returns NULL if there are problems with the hints file,
1237 * or if the search path there is empty.
1238 */
1239static const char *
1240gethints(void)
1241{
1242 static char *hints;
1243
1244 if (hints == NULL) {
1245 int fd;
1246 struct elfhints_hdr hdr;
1247 char *p;
1248
1249 /* Keep from trying again in case the hints file is bad. */
1250 hints = "";
1251
1252 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1)
1253 return NULL;
1254 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1255 hdr.magic != ELFHINTS_MAGIC ||
1256 hdr.version != 1) {
1257 close(fd);
1258 return NULL;
1259 }
1260 p = xmalloc(hdr.dirlistlen + 1);
1261 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1262 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) {
1263 free(p);
1264 close(fd);
1265 return NULL;
1266 }
1267 hints = p;
1268 close(fd);
1269 }
1270 return hints[0] != '\0' ? hints : NULL;
1271}
1272
1273static void
1274init_dag(Obj_Entry *root)
1275{
1276 DoneList donelist;
1277
1278 if (root->dag_inited)
1279 return;
1278 donelist_init(&donelist);
1279 init_dag1(root, root, &donelist);
1280 donelist_init(&donelist);
1281 init_dag1(root, root, &donelist);
1282 root->dag_inited = true;
1280}
1281
1282static void
1283init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1284{
1285 const Needed_Entry *needed;
1286
1287 if (donelist_check(dlp, obj))
1288 return;
1289
1290 obj->refcount++;
1291 objlist_push_tail(&obj->dldags, root);
1292 objlist_push_tail(&root->dagmembers, obj);
1293 for (needed = obj->needed; needed != NULL; needed = needed->next)
1294 if (needed->obj != NULL)
1295 init_dag1(root, needed->obj, dlp);
1296}
1297
1298/*
1299 * Initialize the dynamic linker. The argument is the address at which
1300 * the dynamic linker has been mapped into memory. The primary task of
1301 * this function is to relocate the dynamic linker.
1302 */
1303static void
1304init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
1305{
1306 Obj_Entry objtmp; /* Temporary rtld object */
1307 const Elf_Dyn *dyn_rpath;
1308 const Elf_Dyn *dyn_soname;
1309
1310 /*
1311 * Conjure up an Obj_Entry structure for the dynamic linker.
1312 *
1313 * The "path" member can't be initialized yet because string constants
1314 * cannot yet be accessed. Below we will set it correctly.
1315 */
1316 memset(&objtmp, 0, sizeof(objtmp));
1317 objtmp.path = NULL;
1318 objtmp.rtld = true;
1319 objtmp.mapbase = mapbase;
1320#ifdef PIC
1321 objtmp.relocbase = mapbase;
1322#endif
1323 if (RTLD_IS_DYNAMIC()) {
1324 objtmp.dynamic = rtld_dynamic(&objtmp);
1325 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname);
1326 assert(objtmp.needed == NULL);
1327#if !defined(__mips__)
1328 /* MIPS and SH{3,5} have a bogus DT_TEXTREL. */
1329 assert(!objtmp.textrel);
1330#endif
1331
1332 /*
1333 * Temporarily put the dynamic linker entry into the object list, so
1334 * that symbols can be found.
1335 */
1336
1337 relocate_objects(&objtmp, true, &objtmp);
1338 }
1339
1340 /* Initialize the object list. */
1341 obj_tail = &obj_list;
1342
1343 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1344 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
1345
1346 if (aux_info[AT_PAGESZ] != NULL)
1347 pagesize = aux_info[AT_PAGESZ]->a_un.a_val;
1348 if (aux_info[AT_OSRELDATE] != NULL)
1349 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1350
1351 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname);
1352
1353 /* Replace the path with a dynamically allocated copy. */
1354 obj_rtld.path = xstrdup(PATH_RTLD);
1355
1356 r_debug.r_brk = r_debug_state;
1357 r_debug.r_state = RT_CONSISTENT;
1358}
1359
1360/*
1361 * Add the init functions from a needed object list (and its recursive
1362 * needed objects) to "list". This is not used directly; it is a helper
1363 * function for initlist_add_objects(). The write lock must be held
1364 * when this function is called.
1365 */
1366static void
1367initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1368{
1369 /* Recursively process the successor needed objects. */
1370 if (needed->next != NULL)
1371 initlist_add_neededs(needed->next, list);
1372
1373 /* Process the current needed object. */
1374 if (needed->obj != NULL)
1375 initlist_add_objects(needed->obj, &needed->obj->next, list);
1376}
1377
1378/*
1379 * Scan all of the DAGs rooted in the range of objects from "obj" to
1380 * "tail" and add their init functions to "list". This recurses over
1381 * the DAGs and ensure the proper init ordering such that each object's
1382 * needed libraries are initialized before the object itself. At the
1383 * same time, this function adds the objects to the global finalization
1384 * list "list_fini" in the opposite order. The write lock must be
1385 * held when this function is called.
1386 */
1387static void
1388initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1389{
1390 if (obj->init_scanned || obj->init_done)
1391 return;
1392 obj->init_scanned = true;
1393
1394 /* Recursively process the successor objects. */
1395 if (&obj->next != tail)
1396 initlist_add_objects(obj->next, tail, list);
1397
1398 /* Recursively process the needed objects. */
1399 if (obj->needed != NULL)
1400 initlist_add_neededs(obj->needed, list);
1401
1402 /* Add the object to the init list. */
1403 if (obj->init != (Elf_Addr)NULL)
1404 objlist_push_tail(list, obj);
1405
1406 /* Add the object to the global fini list in the reverse order. */
1407 if (obj->fini != (Elf_Addr)NULL && !obj->on_fini_list) {
1408 objlist_push_head(&list_fini, obj);
1409 obj->on_fini_list = true;
1410 }
1411}
1412
1413#ifndef FPTR_TARGET
1414#define FPTR_TARGET(f) ((Elf_Addr) (f))
1415#endif
1416
1417/*
1418 * Given a shared object, traverse its list of needed objects, and load
1419 * each of them. Returns 0 on success. Generates an error message and
1420 * returns -1 on failure.
1421 */
1422static int
1423load_needed_objects(Obj_Entry *first, int flags)
1424{
1425 Obj_Entry *obj, *obj1;
1426
1427 for (obj = first; obj != NULL; obj = obj->next) {
1428 Needed_Entry *needed;
1429
1430 for (needed = obj->needed; needed != NULL; needed = needed->next) {
1431 obj1 = needed->obj = load_object(obj->strtab + needed->name, obj,
1432 flags & ~RTLD_LO_NOLOAD);
1433 if (obj1 == NULL && !ld_tracing)
1434 return -1;
1435 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) {
1436 dbg("obj %s nodelete", obj1->path);
1437 init_dag(obj1);
1438 ref_dag(obj1);
1439 obj1->ref_nodel = true;
1440 }
1441 }
1442 }
1443
1444 return 0;
1445}
1446
1447static int
1448load_preload_objects(void)
1449{
1450 char *p = ld_preload;
1451 static const char delim[] = " \t:;";
1452
1453 if (p == NULL)
1454 return 0;
1455
1456 p += strspn(p, delim);
1457 while (*p != '\0') {
1458 size_t len = strcspn(p, delim);
1459 char savech;
1460
1461 savech = p[len];
1462 p[len] = '\0';
1463 if (load_object(p, NULL, 0) == NULL)
1464 return -1; /* XXX - cleanup */
1465 p[len] = savech;
1466 p += len;
1467 p += strspn(p, delim);
1468 }
1469 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
1470 return 0;
1471}
1472
1473/*
1474 * Load a shared object into memory, if it is not already loaded.
1475 *
1476 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1477 * on failure.
1478 */
1479static Obj_Entry *
1480load_object(const char *name, const Obj_Entry *refobj, int flags)
1481{
1482 Obj_Entry *obj;
1483 int fd = -1;
1484 struct stat sb;
1485 char *path;
1486
1487 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1488 if (object_match_name(obj, name))
1489 return obj;
1490
1491 path = find_library(name, refobj);
1492 if (path == NULL)
1493 return NULL;
1494
1495 /*
1496 * If we didn't find a match by pathname, open the file and check
1497 * again by device and inode. This avoids false mismatches caused
1498 * by multiple links or ".." in pathnames.
1499 *
1500 * To avoid a race, we open the file and use fstat() rather than
1501 * using stat().
1502 */
1503 if ((fd = open(path, O_RDONLY)) == -1) {
1504 _rtld_error("Cannot open \"%s\"", path);
1505 free(path);
1506 return NULL;
1507 }
1508 if (fstat(fd, &sb) == -1) {
1509 _rtld_error("Cannot fstat \"%s\"", path);
1510 close(fd);
1511 free(path);
1512 return NULL;
1513 }
1514 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1515 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) {
1516 close(fd);
1517 break;
1518 }
1519 }
1520 if (obj != NULL) {
1521 object_add_name(obj, name);
1522 free(path);
1523 close(fd);
1524 return obj;
1525 }
1526 if (flags & RTLD_LO_NOLOAD) {
1527 free(path);
1528 return (NULL);
1529 }
1530
1531 /* First use of this object, so we must map it in */
1532 obj = do_load_object(fd, name, path, &sb, flags);
1533 if (obj == NULL)
1534 free(path);
1535 close(fd);
1536
1537 return obj;
1538}
1539
1540static Obj_Entry *
1541do_load_object(int fd, const char *name, char *path, struct stat *sbp,
1542 int flags)
1543{
1544 Obj_Entry *obj;
1545 struct statfs fs;
1546
1547 /*
1548 * but first, make sure that environment variables haven't been
1549 * used to circumvent the noexec flag on a filesystem.
1550 */
1551 if (dangerous_ld_env) {
1552 if (fstatfs(fd, &fs) != 0) {
1553 _rtld_error("Cannot fstatfs \"%s\"", path);
1554 return NULL;
1555 }
1556 if (fs.f_flags & MNT_NOEXEC) {
1557 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
1558 return NULL;
1559 }
1560 }
1561 dbg("loading \"%s\"", path);
1562 obj = map_object(fd, path, sbp);
1563 if (obj == NULL)
1564 return NULL;
1565
1566 object_add_name(obj, name);
1567 obj->path = path;
1568 digest_dynamic(obj, 0);
1569 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
1570 RTLD_LO_DLOPEN) {
1571 dbg("refusing to load non-loadable \"%s\"", obj->path);
1572 _rtld_error("Cannot dlopen non-loadable %s", obj->path);
1573 munmap(obj->mapbase, obj->mapsize);
1574 obj_free(obj);
1575 return (NULL);
1576 }
1577
1578 *obj_tail = obj;
1579 obj_tail = &obj->next;
1580 obj_count++;
1581 obj_loads++;
1582 linkmap_add(obj); /* for GDB & dlinfo() */
1583
1584 dbg(" %p .. %p: %s", obj->mapbase,
1585 obj->mapbase + obj->mapsize - 1, obj->path);
1586 if (obj->textrel)
1587 dbg(" WARNING: %s has impure text", obj->path);
1588 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
1589 obj->path);
1590
1591 return obj;
1592}
1593
1594static Obj_Entry *
1595obj_from_addr(const void *addr)
1596{
1597 Obj_Entry *obj;
1598
1599 for (obj = obj_list; obj != NULL; obj = obj->next) {
1600 if (addr < (void *) obj->mapbase)
1601 continue;
1602 if (addr < (void *) (obj->mapbase + obj->mapsize))
1603 return obj;
1604 }
1605 return NULL;
1606}
1607
1608/*
1609 * Call the finalization functions for each of the objects in "list"
1610 * which are unreferenced. All of the objects are expected to have
1611 * non-NULL fini functions.
1612 */
1613static void
1614objlist_call_fini(Objlist *list, bool force, int *lockstate)
1615{
1616 Objlist_Entry *elm, *elm_tmp;
1617 char *saved_msg;
1618
1619 /*
1620 * Preserve the current error message since a fini function might
1621 * call into the dynamic linker and overwrite it.
1622 */
1623 saved_msg = errmsg_save();
1624 STAILQ_FOREACH_SAFE(elm, list, link, elm_tmp) {
1625 if (elm->obj->refcount == 0 || force) {
1626 dbg("calling fini function for %s at %p", elm->obj->path,
1627 (void *)elm->obj->fini);
1628 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0,
1629 elm->obj->path);
1630 /* Remove object from fini list to prevent recursive invocation. */
1631 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1632 wlock_release(rtld_bind_lock, *lockstate);
1633 call_initfini_pointer(elm->obj, elm->obj->fini);
1634 *lockstate = wlock_acquire(rtld_bind_lock);
1635 /* No need to free anything if process is going down. */
1636 if (!force)
1637 free(elm);
1638 }
1639 }
1640 errmsg_restore(saved_msg);
1641}
1642
1643/*
1644 * Call the initialization functions for each of the objects in
1645 * "list". All of the objects are expected to have non-NULL init
1646 * functions.
1647 */
1648static void
1649objlist_call_init(Objlist *list, int *lockstate)
1650{
1651 Objlist_Entry *elm;
1652 Obj_Entry *obj;
1653 char *saved_msg;
1654
1655 /*
1656 * Clean init_scanned flag so that objects can be rechecked and
1657 * possibly initialized earlier if any of vectors called below
1658 * cause the change by using dlopen.
1659 */
1660 for (obj = obj_list; obj != NULL; obj = obj->next)
1661 obj->init_scanned = false;
1662
1663 /*
1664 * Preserve the current error message since an init function might
1665 * call into the dynamic linker and overwrite it.
1666 */
1667 saved_msg = errmsg_save();
1668 STAILQ_FOREACH(elm, list, link) {
1669 if (elm->obj->init_done) /* Initialized early. */
1670 continue;
1671 dbg("calling init function for %s at %p", elm->obj->path,
1672 (void *)elm->obj->init);
1673 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0,
1674 elm->obj->path);
1675 /*
1676 * Race: other thread might try to use this object before current
1677 * one completes the initilization. Not much can be done here
1678 * without better locking.
1679 */
1680 elm->obj->init_done = true;
1681 wlock_release(rtld_bind_lock, *lockstate);
1682 call_initfini_pointer(elm->obj, elm->obj->init);
1683 *lockstate = wlock_acquire(rtld_bind_lock);
1684 }
1685 errmsg_restore(saved_msg);
1686}
1687
1688static void
1689objlist_clear(Objlist *list)
1690{
1691 Objlist_Entry *elm;
1692
1693 while (!STAILQ_EMPTY(list)) {
1694 elm = STAILQ_FIRST(list);
1695 STAILQ_REMOVE_HEAD(list, link);
1696 free(elm);
1697 }
1698}
1699
1700static Objlist_Entry *
1701objlist_find(Objlist *list, const Obj_Entry *obj)
1702{
1703 Objlist_Entry *elm;
1704
1705 STAILQ_FOREACH(elm, list, link)
1706 if (elm->obj == obj)
1707 return elm;
1708 return NULL;
1709}
1710
1711static void
1712objlist_init(Objlist *list)
1713{
1714 STAILQ_INIT(list);
1715}
1716
1717static void
1718objlist_push_head(Objlist *list, Obj_Entry *obj)
1719{
1720 Objlist_Entry *elm;
1721
1722 elm = NEW(Objlist_Entry);
1723 elm->obj = obj;
1724 STAILQ_INSERT_HEAD(list, elm, link);
1725}
1726
1727static void
1728objlist_push_tail(Objlist *list, Obj_Entry *obj)
1729{
1730 Objlist_Entry *elm;
1731
1732 elm = NEW(Objlist_Entry);
1733 elm->obj = obj;
1734 STAILQ_INSERT_TAIL(list, elm, link);
1735}
1736
1737static void
1738objlist_remove(Objlist *list, Obj_Entry *obj)
1739{
1740 Objlist_Entry *elm;
1741
1742 if ((elm = objlist_find(list, obj)) != NULL) {
1743 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1744 free(elm);
1745 }
1746}
1747
1748/*
1749 * Relocate newly-loaded shared objects. The argument is a pointer to
1750 * the Obj_Entry for the first such object. All objects from the first
1751 * to the end of the list of objects are relocated. Returns 0 on success,
1752 * or -1 on failure.
1753 */
1754static int
1755relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
1756{
1757 Obj_Entry *obj;
1758
1759 for (obj = first; obj != NULL; obj = obj->next) {
1760 if (obj != rtldobj)
1761 dbg("relocating \"%s\"", obj->path);
1762 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1763 obj->symtab == NULL || obj->strtab == NULL) {
1764 _rtld_error("%s: Shared object has no run-time symbol table",
1765 obj->path);
1766 return -1;
1767 }
1768
1769 if (obj->textrel) {
1770 /* There are relocations to the write-protected text segment. */
1771 if (mprotect(obj->mapbase, obj->textsize,
1772 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1773 _rtld_error("%s: Cannot write-enable text segment: %s",
1774 obj->path, strerror(errno));
1775 return -1;
1776 }
1777 }
1778
1779 /* Process the non-PLT relocations. */
1780 if (reloc_non_plt(obj, rtldobj))
1781 return -1;
1782
1783 if (obj->textrel) { /* Re-protected the text segment. */
1784 if (mprotect(obj->mapbase, obj->textsize,
1785 PROT_READ|PROT_EXEC) == -1) {
1786 _rtld_error("%s: Cannot write-protect text segment: %s",
1787 obj->path, strerror(errno));
1788 return -1;
1789 }
1790 }
1791
1792 /* Process the PLT relocations. */
1793 if (reloc_plt(obj) == -1)
1794 return -1;
1795 /* Relocate the jump slots if we are doing immediate binding. */
1796 if (obj->bind_now || bind_now)
1797 if (reloc_jmpslots(obj) == -1)
1798 return -1;
1799
1800
1801 /*
1802 * Set up the magic number and version in the Obj_Entry. These
1803 * were checked in the crt1.o from the original ElfKit, so we
1804 * set them for backward compatibility.
1805 */
1806 obj->magic = RTLD_MAGIC;
1807 obj->version = RTLD_VERSION;
1808
1809 /* Set the special PLT or GOT entries. */
1810 init_pltgot(obj);
1811 }
1812
1813 return 0;
1814}
1815
1816/*
1817 * Cleanup procedure. It will be called (by the atexit mechanism) just
1818 * before the process exits.
1819 */
1820static void
1821rtld_exit(void)
1822{
1823 int lockstate;
1824
1825 lockstate = wlock_acquire(rtld_bind_lock);
1826 dbg("rtld_exit()");
1827 objlist_call_fini(&list_fini, true, &lockstate);
1828 /* No need to remove the items from the list, since we are exiting. */
1829 if (!libmap_disable)
1830 lm_fini();
1831 wlock_release(rtld_bind_lock, lockstate);
1832}
1833
1834static void *
1835path_enumerate(const char *path, path_enum_proc callback, void *arg)
1836{
1837#ifdef COMPAT_32BIT
1838 const char *trans;
1839#endif
1840 if (path == NULL)
1841 return (NULL);
1842
1843 path += strspn(path, ":;");
1844 while (*path != '\0') {
1845 size_t len;
1846 char *res;
1847
1848 len = strcspn(path, ":;");
1849#ifdef COMPAT_32BIT
1850 trans = lm_findn(NULL, path, len);
1851 if (trans)
1852 res = callback(trans, strlen(trans), arg);
1853 else
1854#endif
1855 res = callback(path, len, arg);
1856
1857 if (res != NULL)
1858 return (res);
1859
1860 path += len;
1861 path += strspn(path, ":;");
1862 }
1863
1864 return (NULL);
1865}
1866
1867struct try_library_args {
1868 const char *name;
1869 size_t namelen;
1870 char *buffer;
1871 size_t buflen;
1872};
1873
1874static void *
1875try_library_path(const char *dir, size_t dirlen, void *param)
1876{
1877 struct try_library_args *arg;
1878
1879 arg = param;
1880 if (*dir == '/' || trust) {
1881 char *pathname;
1882
1883 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
1884 return (NULL);
1885
1886 pathname = arg->buffer;
1887 strncpy(pathname, dir, dirlen);
1888 pathname[dirlen] = '/';
1889 strcpy(pathname + dirlen + 1, arg->name);
1890
1891 dbg(" Trying \"%s\"", pathname);
1892 if (access(pathname, F_OK) == 0) { /* We found it */
1893 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
1894 strcpy(pathname, arg->buffer);
1895 return (pathname);
1896 }
1897 }
1898 return (NULL);
1899}
1900
1901static char *
1902search_library_path(const char *name, const char *path)
1903{
1904 char *p;
1905 struct try_library_args arg;
1906
1907 if (path == NULL)
1908 return NULL;
1909
1910 arg.name = name;
1911 arg.namelen = strlen(name);
1912 arg.buffer = xmalloc(PATH_MAX);
1913 arg.buflen = PATH_MAX;
1914
1915 p = path_enumerate(path, try_library_path, &arg);
1916
1917 free(arg.buffer);
1918
1919 return (p);
1920}
1921
1922int
1923dlclose(void *handle)
1924{
1925 Obj_Entry *root;
1926 int lockstate;
1927
1928 lockstate = wlock_acquire(rtld_bind_lock);
1929 root = dlcheck(handle);
1930 if (root == NULL) {
1931 wlock_release(rtld_bind_lock, lockstate);
1932 return -1;
1933 }
1934 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
1935 root->path);
1936
1937 /* Unreference the object and its dependencies. */
1938 root->dl_refcount--;
1939
1940 unref_dag(root);
1941
1942 if (root->refcount == 0) {
1943 /*
1944 * The object is no longer referenced, so we must unload it.
1945 * First, call the fini functions.
1946 */
1947 objlist_call_fini(&list_fini, false, &lockstate);
1948
1949 /* Finish cleaning up the newly-unreferenced objects. */
1950 GDB_STATE(RT_DELETE,&root->linkmap);
1951 unload_object(root);
1952 GDB_STATE(RT_CONSISTENT,NULL);
1953 }
1954 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
1955 wlock_release(rtld_bind_lock, lockstate);
1956 return 0;
1957}
1958
1959char *
1960dlerror(void)
1961{
1962 char *msg = error_message;
1963 error_message = NULL;
1964 return msg;
1965}
1966
1967/*
1968 * This function is deprecated and has no effect.
1969 */
1970void
1971dllockinit(void *context,
1972 void *(*lock_create)(void *context),
1973 void (*rlock_acquire)(void *lock),
1974 void (*wlock_acquire)(void *lock),
1975 void (*lock_release)(void *lock),
1976 void (*lock_destroy)(void *lock),
1977 void (*context_destroy)(void *context))
1978{
1979 static void *cur_context;
1980 static void (*cur_context_destroy)(void *);
1981
1982 /* Just destroy the context from the previous call, if necessary. */
1983 if (cur_context_destroy != NULL)
1984 cur_context_destroy(cur_context);
1985 cur_context = context;
1986 cur_context_destroy = context_destroy;
1987}
1988
1989void *
1990dlopen(const char *name, int mode)
1991{
1992 Obj_Entry **old_obj_tail;
1993 Obj_Entry *obj;
1994 Objlist initlist;
1995 int result, lockstate, nodelete, lo_flags;
1996
1997 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
1998 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
1999 if (ld_tracing != NULL)
2000 environ = (char **)*get_program_var_addr("environ");
2001 nodelete = mode & RTLD_NODELETE;
2002 lo_flags = RTLD_LO_DLOPEN;
2003 if (mode & RTLD_NOLOAD)
2004 lo_flags |= RTLD_LO_NOLOAD;
2005 if (ld_tracing != NULL)
2006 lo_flags |= RTLD_LO_TRACE;
2007
2008 objlist_init(&initlist);
2009
2010 lockstate = wlock_acquire(rtld_bind_lock);
2011 GDB_STATE(RT_ADD,NULL);
2012
2013 old_obj_tail = obj_tail;
2014 obj = NULL;
2015 if (name == NULL) {
2016 obj = obj_main;
2017 obj->refcount++;
2018 } else {
2019 obj = load_object(name, obj_main, lo_flags);
2020 }
2021
2022 if (obj) {
2023 obj->dl_refcount++;
2024 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
2025 objlist_push_tail(&list_global, obj);
2026 mode &= RTLD_MODEMASK;
2027 if (*old_obj_tail != NULL) { /* We loaded something new. */
2028 assert(*old_obj_tail == obj);
2029 result = load_needed_objects(obj, RTLD_LO_DLOPEN);
2030 init_dag(obj);
2031 if (result != -1)
2032 result = rtld_verify_versions(&obj->dagmembers);
2033 if (result != -1 && ld_tracing)
2034 goto trace;
2035 if (result == -1 ||
2036 (relocate_objects(obj, mode == RTLD_NOW, &obj_rtld)) == -1) {
2037 obj->dl_refcount--;
2038 unref_dag(obj);
2039 if (obj->refcount == 0)
2040 unload_object(obj);
2041 obj = NULL;
2042 } else {
2043 /* Make list of init functions to call. */
2044 initlist_add_objects(obj, &obj->next, &initlist);
2045 }
2046 } else {
2047
1283}
1284
1285static void
1286init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1287{
1288 const Needed_Entry *needed;
1289
1290 if (donelist_check(dlp, obj))
1291 return;
1292
1293 obj->refcount++;
1294 objlist_push_tail(&obj->dldags, root);
1295 objlist_push_tail(&root->dagmembers, obj);
1296 for (needed = obj->needed; needed != NULL; needed = needed->next)
1297 if (needed->obj != NULL)
1298 init_dag1(root, needed->obj, dlp);
1299}
1300
1301/*
1302 * Initialize the dynamic linker. The argument is the address at which
1303 * the dynamic linker has been mapped into memory. The primary task of
1304 * this function is to relocate the dynamic linker.
1305 */
1306static void
1307init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
1308{
1309 Obj_Entry objtmp; /* Temporary rtld object */
1310 const Elf_Dyn *dyn_rpath;
1311 const Elf_Dyn *dyn_soname;
1312
1313 /*
1314 * Conjure up an Obj_Entry structure for the dynamic linker.
1315 *
1316 * The "path" member can't be initialized yet because string constants
1317 * cannot yet be accessed. Below we will set it correctly.
1318 */
1319 memset(&objtmp, 0, sizeof(objtmp));
1320 objtmp.path = NULL;
1321 objtmp.rtld = true;
1322 objtmp.mapbase = mapbase;
1323#ifdef PIC
1324 objtmp.relocbase = mapbase;
1325#endif
1326 if (RTLD_IS_DYNAMIC()) {
1327 objtmp.dynamic = rtld_dynamic(&objtmp);
1328 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname);
1329 assert(objtmp.needed == NULL);
1330#if !defined(__mips__)
1331 /* MIPS and SH{3,5} have a bogus DT_TEXTREL. */
1332 assert(!objtmp.textrel);
1333#endif
1334
1335 /*
1336 * Temporarily put the dynamic linker entry into the object list, so
1337 * that symbols can be found.
1338 */
1339
1340 relocate_objects(&objtmp, true, &objtmp);
1341 }
1342
1343 /* Initialize the object list. */
1344 obj_tail = &obj_list;
1345
1346 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1347 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
1348
1349 if (aux_info[AT_PAGESZ] != NULL)
1350 pagesize = aux_info[AT_PAGESZ]->a_un.a_val;
1351 if (aux_info[AT_OSRELDATE] != NULL)
1352 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1353
1354 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname);
1355
1356 /* Replace the path with a dynamically allocated copy. */
1357 obj_rtld.path = xstrdup(PATH_RTLD);
1358
1359 r_debug.r_brk = r_debug_state;
1360 r_debug.r_state = RT_CONSISTENT;
1361}
1362
1363/*
1364 * Add the init functions from a needed object list (and its recursive
1365 * needed objects) to "list". This is not used directly; it is a helper
1366 * function for initlist_add_objects(). The write lock must be held
1367 * when this function is called.
1368 */
1369static void
1370initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1371{
1372 /* Recursively process the successor needed objects. */
1373 if (needed->next != NULL)
1374 initlist_add_neededs(needed->next, list);
1375
1376 /* Process the current needed object. */
1377 if (needed->obj != NULL)
1378 initlist_add_objects(needed->obj, &needed->obj->next, list);
1379}
1380
1381/*
1382 * Scan all of the DAGs rooted in the range of objects from "obj" to
1383 * "tail" and add their init functions to "list". This recurses over
1384 * the DAGs and ensure the proper init ordering such that each object's
1385 * needed libraries are initialized before the object itself. At the
1386 * same time, this function adds the objects to the global finalization
1387 * list "list_fini" in the opposite order. The write lock must be
1388 * held when this function is called.
1389 */
1390static void
1391initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1392{
1393 if (obj->init_scanned || obj->init_done)
1394 return;
1395 obj->init_scanned = true;
1396
1397 /* Recursively process the successor objects. */
1398 if (&obj->next != tail)
1399 initlist_add_objects(obj->next, tail, list);
1400
1401 /* Recursively process the needed objects. */
1402 if (obj->needed != NULL)
1403 initlist_add_neededs(obj->needed, list);
1404
1405 /* Add the object to the init list. */
1406 if (obj->init != (Elf_Addr)NULL)
1407 objlist_push_tail(list, obj);
1408
1409 /* Add the object to the global fini list in the reverse order. */
1410 if (obj->fini != (Elf_Addr)NULL && !obj->on_fini_list) {
1411 objlist_push_head(&list_fini, obj);
1412 obj->on_fini_list = true;
1413 }
1414}
1415
1416#ifndef FPTR_TARGET
1417#define FPTR_TARGET(f) ((Elf_Addr) (f))
1418#endif
1419
1420/*
1421 * Given a shared object, traverse its list of needed objects, and load
1422 * each of them. Returns 0 on success. Generates an error message and
1423 * returns -1 on failure.
1424 */
1425static int
1426load_needed_objects(Obj_Entry *first, int flags)
1427{
1428 Obj_Entry *obj, *obj1;
1429
1430 for (obj = first; obj != NULL; obj = obj->next) {
1431 Needed_Entry *needed;
1432
1433 for (needed = obj->needed; needed != NULL; needed = needed->next) {
1434 obj1 = needed->obj = load_object(obj->strtab + needed->name, obj,
1435 flags & ~RTLD_LO_NOLOAD);
1436 if (obj1 == NULL && !ld_tracing)
1437 return -1;
1438 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) {
1439 dbg("obj %s nodelete", obj1->path);
1440 init_dag(obj1);
1441 ref_dag(obj1);
1442 obj1->ref_nodel = true;
1443 }
1444 }
1445 }
1446
1447 return 0;
1448}
1449
1450static int
1451load_preload_objects(void)
1452{
1453 char *p = ld_preload;
1454 static const char delim[] = " \t:;";
1455
1456 if (p == NULL)
1457 return 0;
1458
1459 p += strspn(p, delim);
1460 while (*p != '\0') {
1461 size_t len = strcspn(p, delim);
1462 char savech;
1463
1464 savech = p[len];
1465 p[len] = '\0';
1466 if (load_object(p, NULL, 0) == NULL)
1467 return -1; /* XXX - cleanup */
1468 p[len] = savech;
1469 p += len;
1470 p += strspn(p, delim);
1471 }
1472 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
1473 return 0;
1474}
1475
1476/*
1477 * Load a shared object into memory, if it is not already loaded.
1478 *
1479 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1480 * on failure.
1481 */
1482static Obj_Entry *
1483load_object(const char *name, const Obj_Entry *refobj, int flags)
1484{
1485 Obj_Entry *obj;
1486 int fd = -1;
1487 struct stat sb;
1488 char *path;
1489
1490 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1491 if (object_match_name(obj, name))
1492 return obj;
1493
1494 path = find_library(name, refobj);
1495 if (path == NULL)
1496 return NULL;
1497
1498 /*
1499 * If we didn't find a match by pathname, open the file and check
1500 * again by device and inode. This avoids false mismatches caused
1501 * by multiple links or ".." in pathnames.
1502 *
1503 * To avoid a race, we open the file and use fstat() rather than
1504 * using stat().
1505 */
1506 if ((fd = open(path, O_RDONLY)) == -1) {
1507 _rtld_error("Cannot open \"%s\"", path);
1508 free(path);
1509 return NULL;
1510 }
1511 if (fstat(fd, &sb) == -1) {
1512 _rtld_error("Cannot fstat \"%s\"", path);
1513 close(fd);
1514 free(path);
1515 return NULL;
1516 }
1517 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1518 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) {
1519 close(fd);
1520 break;
1521 }
1522 }
1523 if (obj != NULL) {
1524 object_add_name(obj, name);
1525 free(path);
1526 close(fd);
1527 return obj;
1528 }
1529 if (flags & RTLD_LO_NOLOAD) {
1530 free(path);
1531 return (NULL);
1532 }
1533
1534 /* First use of this object, so we must map it in */
1535 obj = do_load_object(fd, name, path, &sb, flags);
1536 if (obj == NULL)
1537 free(path);
1538 close(fd);
1539
1540 return obj;
1541}
1542
1543static Obj_Entry *
1544do_load_object(int fd, const char *name, char *path, struct stat *sbp,
1545 int flags)
1546{
1547 Obj_Entry *obj;
1548 struct statfs fs;
1549
1550 /*
1551 * but first, make sure that environment variables haven't been
1552 * used to circumvent the noexec flag on a filesystem.
1553 */
1554 if (dangerous_ld_env) {
1555 if (fstatfs(fd, &fs) != 0) {
1556 _rtld_error("Cannot fstatfs \"%s\"", path);
1557 return NULL;
1558 }
1559 if (fs.f_flags & MNT_NOEXEC) {
1560 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
1561 return NULL;
1562 }
1563 }
1564 dbg("loading \"%s\"", path);
1565 obj = map_object(fd, path, sbp);
1566 if (obj == NULL)
1567 return NULL;
1568
1569 object_add_name(obj, name);
1570 obj->path = path;
1571 digest_dynamic(obj, 0);
1572 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
1573 RTLD_LO_DLOPEN) {
1574 dbg("refusing to load non-loadable \"%s\"", obj->path);
1575 _rtld_error("Cannot dlopen non-loadable %s", obj->path);
1576 munmap(obj->mapbase, obj->mapsize);
1577 obj_free(obj);
1578 return (NULL);
1579 }
1580
1581 *obj_tail = obj;
1582 obj_tail = &obj->next;
1583 obj_count++;
1584 obj_loads++;
1585 linkmap_add(obj); /* for GDB & dlinfo() */
1586
1587 dbg(" %p .. %p: %s", obj->mapbase,
1588 obj->mapbase + obj->mapsize - 1, obj->path);
1589 if (obj->textrel)
1590 dbg(" WARNING: %s has impure text", obj->path);
1591 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
1592 obj->path);
1593
1594 return obj;
1595}
1596
1597static Obj_Entry *
1598obj_from_addr(const void *addr)
1599{
1600 Obj_Entry *obj;
1601
1602 for (obj = obj_list; obj != NULL; obj = obj->next) {
1603 if (addr < (void *) obj->mapbase)
1604 continue;
1605 if (addr < (void *) (obj->mapbase + obj->mapsize))
1606 return obj;
1607 }
1608 return NULL;
1609}
1610
1611/*
1612 * Call the finalization functions for each of the objects in "list"
1613 * which are unreferenced. All of the objects are expected to have
1614 * non-NULL fini functions.
1615 */
1616static void
1617objlist_call_fini(Objlist *list, bool force, int *lockstate)
1618{
1619 Objlist_Entry *elm, *elm_tmp;
1620 char *saved_msg;
1621
1622 /*
1623 * Preserve the current error message since a fini function might
1624 * call into the dynamic linker and overwrite it.
1625 */
1626 saved_msg = errmsg_save();
1627 STAILQ_FOREACH_SAFE(elm, list, link, elm_tmp) {
1628 if (elm->obj->refcount == 0 || force) {
1629 dbg("calling fini function for %s at %p", elm->obj->path,
1630 (void *)elm->obj->fini);
1631 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0,
1632 elm->obj->path);
1633 /* Remove object from fini list to prevent recursive invocation. */
1634 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1635 wlock_release(rtld_bind_lock, *lockstate);
1636 call_initfini_pointer(elm->obj, elm->obj->fini);
1637 *lockstate = wlock_acquire(rtld_bind_lock);
1638 /* No need to free anything if process is going down. */
1639 if (!force)
1640 free(elm);
1641 }
1642 }
1643 errmsg_restore(saved_msg);
1644}
1645
1646/*
1647 * Call the initialization functions for each of the objects in
1648 * "list". All of the objects are expected to have non-NULL init
1649 * functions.
1650 */
1651static void
1652objlist_call_init(Objlist *list, int *lockstate)
1653{
1654 Objlist_Entry *elm;
1655 Obj_Entry *obj;
1656 char *saved_msg;
1657
1658 /*
1659 * Clean init_scanned flag so that objects can be rechecked and
1660 * possibly initialized earlier if any of vectors called below
1661 * cause the change by using dlopen.
1662 */
1663 for (obj = obj_list; obj != NULL; obj = obj->next)
1664 obj->init_scanned = false;
1665
1666 /*
1667 * Preserve the current error message since an init function might
1668 * call into the dynamic linker and overwrite it.
1669 */
1670 saved_msg = errmsg_save();
1671 STAILQ_FOREACH(elm, list, link) {
1672 if (elm->obj->init_done) /* Initialized early. */
1673 continue;
1674 dbg("calling init function for %s at %p", elm->obj->path,
1675 (void *)elm->obj->init);
1676 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0,
1677 elm->obj->path);
1678 /*
1679 * Race: other thread might try to use this object before current
1680 * one completes the initilization. Not much can be done here
1681 * without better locking.
1682 */
1683 elm->obj->init_done = true;
1684 wlock_release(rtld_bind_lock, *lockstate);
1685 call_initfini_pointer(elm->obj, elm->obj->init);
1686 *lockstate = wlock_acquire(rtld_bind_lock);
1687 }
1688 errmsg_restore(saved_msg);
1689}
1690
1691static void
1692objlist_clear(Objlist *list)
1693{
1694 Objlist_Entry *elm;
1695
1696 while (!STAILQ_EMPTY(list)) {
1697 elm = STAILQ_FIRST(list);
1698 STAILQ_REMOVE_HEAD(list, link);
1699 free(elm);
1700 }
1701}
1702
1703static Objlist_Entry *
1704objlist_find(Objlist *list, const Obj_Entry *obj)
1705{
1706 Objlist_Entry *elm;
1707
1708 STAILQ_FOREACH(elm, list, link)
1709 if (elm->obj == obj)
1710 return elm;
1711 return NULL;
1712}
1713
1714static void
1715objlist_init(Objlist *list)
1716{
1717 STAILQ_INIT(list);
1718}
1719
1720static void
1721objlist_push_head(Objlist *list, Obj_Entry *obj)
1722{
1723 Objlist_Entry *elm;
1724
1725 elm = NEW(Objlist_Entry);
1726 elm->obj = obj;
1727 STAILQ_INSERT_HEAD(list, elm, link);
1728}
1729
1730static void
1731objlist_push_tail(Objlist *list, Obj_Entry *obj)
1732{
1733 Objlist_Entry *elm;
1734
1735 elm = NEW(Objlist_Entry);
1736 elm->obj = obj;
1737 STAILQ_INSERT_TAIL(list, elm, link);
1738}
1739
1740static void
1741objlist_remove(Objlist *list, Obj_Entry *obj)
1742{
1743 Objlist_Entry *elm;
1744
1745 if ((elm = objlist_find(list, obj)) != NULL) {
1746 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1747 free(elm);
1748 }
1749}
1750
1751/*
1752 * Relocate newly-loaded shared objects. The argument is a pointer to
1753 * the Obj_Entry for the first such object. All objects from the first
1754 * to the end of the list of objects are relocated. Returns 0 on success,
1755 * or -1 on failure.
1756 */
1757static int
1758relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
1759{
1760 Obj_Entry *obj;
1761
1762 for (obj = first; obj != NULL; obj = obj->next) {
1763 if (obj != rtldobj)
1764 dbg("relocating \"%s\"", obj->path);
1765 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1766 obj->symtab == NULL || obj->strtab == NULL) {
1767 _rtld_error("%s: Shared object has no run-time symbol table",
1768 obj->path);
1769 return -1;
1770 }
1771
1772 if (obj->textrel) {
1773 /* There are relocations to the write-protected text segment. */
1774 if (mprotect(obj->mapbase, obj->textsize,
1775 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1776 _rtld_error("%s: Cannot write-enable text segment: %s",
1777 obj->path, strerror(errno));
1778 return -1;
1779 }
1780 }
1781
1782 /* Process the non-PLT relocations. */
1783 if (reloc_non_plt(obj, rtldobj))
1784 return -1;
1785
1786 if (obj->textrel) { /* Re-protected the text segment. */
1787 if (mprotect(obj->mapbase, obj->textsize,
1788 PROT_READ|PROT_EXEC) == -1) {
1789 _rtld_error("%s: Cannot write-protect text segment: %s",
1790 obj->path, strerror(errno));
1791 return -1;
1792 }
1793 }
1794
1795 /* Process the PLT relocations. */
1796 if (reloc_plt(obj) == -1)
1797 return -1;
1798 /* Relocate the jump slots if we are doing immediate binding. */
1799 if (obj->bind_now || bind_now)
1800 if (reloc_jmpslots(obj) == -1)
1801 return -1;
1802
1803
1804 /*
1805 * Set up the magic number and version in the Obj_Entry. These
1806 * were checked in the crt1.o from the original ElfKit, so we
1807 * set them for backward compatibility.
1808 */
1809 obj->magic = RTLD_MAGIC;
1810 obj->version = RTLD_VERSION;
1811
1812 /* Set the special PLT or GOT entries. */
1813 init_pltgot(obj);
1814 }
1815
1816 return 0;
1817}
1818
1819/*
1820 * Cleanup procedure. It will be called (by the atexit mechanism) just
1821 * before the process exits.
1822 */
1823static void
1824rtld_exit(void)
1825{
1826 int lockstate;
1827
1828 lockstate = wlock_acquire(rtld_bind_lock);
1829 dbg("rtld_exit()");
1830 objlist_call_fini(&list_fini, true, &lockstate);
1831 /* No need to remove the items from the list, since we are exiting. */
1832 if (!libmap_disable)
1833 lm_fini();
1834 wlock_release(rtld_bind_lock, lockstate);
1835}
1836
1837static void *
1838path_enumerate(const char *path, path_enum_proc callback, void *arg)
1839{
1840#ifdef COMPAT_32BIT
1841 const char *trans;
1842#endif
1843 if (path == NULL)
1844 return (NULL);
1845
1846 path += strspn(path, ":;");
1847 while (*path != '\0') {
1848 size_t len;
1849 char *res;
1850
1851 len = strcspn(path, ":;");
1852#ifdef COMPAT_32BIT
1853 trans = lm_findn(NULL, path, len);
1854 if (trans)
1855 res = callback(trans, strlen(trans), arg);
1856 else
1857#endif
1858 res = callback(path, len, arg);
1859
1860 if (res != NULL)
1861 return (res);
1862
1863 path += len;
1864 path += strspn(path, ":;");
1865 }
1866
1867 return (NULL);
1868}
1869
1870struct try_library_args {
1871 const char *name;
1872 size_t namelen;
1873 char *buffer;
1874 size_t buflen;
1875};
1876
1877static void *
1878try_library_path(const char *dir, size_t dirlen, void *param)
1879{
1880 struct try_library_args *arg;
1881
1882 arg = param;
1883 if (*dir == '/' || trust) {
1884 char *pathname;
1885
1886 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
1887 return (NULL);
1888
1889 pathname = arg->buffer;
1890 strncpy(pathname, dir, dirlen);
1891 pathname[dirlen] = '/';
1892 strcpy(pathname + dirlen + 1, arg->name);
1893
1894 dbg(" Trying \"%s\"", pathname);
1895 if (access(pathname, F_OK) == 0) { /* We found it */
1896 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
1897 strcpy(pathname, arg->buffer);
1898 return (pathname);
1899 }
1900 }
1901 return (NULL);
1902}
1903
1904static char *
1905search_library_path(const char *name, const char *path)
1906{
1907 char *p;
1908 struct try_library_args arg;
1909
1910 if (path == NULL)
1911 return NULL;
1912
1913 arg.name = name;
1914 arg.namelen = strlen(name);
1915 arg.buffer = xmalloc(PATH_MAX);
1916 arg.buflen = PATH_MAX;
1917
1918 p = path_enumerate(path, try_library_path, &arg);
1919
1920 free(arg.buffer);
1921
1922 return (p);
1923}
1924
1925int
1926dlclose(void *handle)
1927{
1928 Obj_Entry *root;
1929 int lockstate;
1930
1931 lockstate = wlock_acquire(rtld_bind_lock);
1932 root = dlcheck(handle);
1933 if (root == NULL) {
1934 wlock_release(rtld_bind_lock, lockstate);
1935 return -1;
1936 }
1937 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
1938 root->path);
1939
1940 /* Unreference the object and its dependencies. */
1941 root->dl_refcount--;
1942
1943 unref_dag(root);
1944
1945 if (root->refcount == 0) {
1946 /*
1947 * The object is no longer referenced, so we must unload it.
1948 * First, call the fini functions.
1949 */
1950 objlist_call_fini(&list_fini, false, &lockstate);
1951
1952 /* Finish cleaning up the newly-unreferenced objects. */
1953 GDB_STATE(RT_DELETE,&root->linkmap);
1954 unload_object(root);
1955 GDB_STATE(RT_CONSISTENT,NULL);
1956 }
1957 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
1958 wlock_release(rtld_bind_lock, lockstate);
1959 return 0;
1960}
1961
1962char *
1963dlerror(void)
1964{
1965 char *msg = error_message;
1966 error_message = NULL;
1967 return msg;
1968}
1969
1970/*
1971 * This function is deprecated and has no effect.
1972 */
1973void
1974dllockinit(void *context,
1975 void *(*lock_create)(void *context),
1976 void (*rlock_acquire)(void *lock),
1977 void (*wlock_acquire)(void *lock),
1978 void (*lock_release)(void *lock),
1979 void (*lock_destroy)(void *lock),
1980 void (*context_destroy)(void *context))
1981{
1982 static void *cur_context;
1983 static void (*cur_context_destroy)(void *);
1984
1985 /* Just destroy the context from the previous call, if necessary. */
1986 if (cur_context_destroy != NULL)
1987 cur_context_destroy(cur_context);
1988 cur_context = context;
1989 cur_context_destroy = context_destroy;
1990}
1991
1992void *
1993dlopen(const char *name, int mode)
1994{
1995 Obj_Entry **old_obj_tail;
1996 Obj_Entry *obj;
1997 Objlist initlist;
1998 int result, lockstate, nodelete, lo_flags;
1999
2000 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
2001 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
2002 if (ld_tracing != NULL)
2003 environ = (char **)*get_program_var_addr("environ");
2004 nodelete = mode & RTLD_NODELETE;
2005 lo_flags = RTLD_LO_DLOPEN;
2006 if (mode & RTLD_NOLOAD)
2007 lo_flags |= RTLD_LO_NOLOAD;
2008 if (ld_tracing != NULL)
2009 lo_flags |= RTLD_LO_TRACE;
2010
2011 objlist_init(&initlist);
2012
2013 lockstate = wlock_acquire(rtld_bind_lock);
2014 GDB_STATE(RT_ADD,NULL);
2015
2016 old_obj_tail = obj_tail;
2017 obj = NULL;
2018 if (name == NULL) {
2019 obj = obj_main;
2020 obj->refcount++;
2021 } else {
2022 obj = load_object(name, obj_main, lo_flags);
2023 }
2024
2025 if (obj) {
2026 obj->dl_refcount++;
2027 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
2028 objlist_push_tail(&list_global, obj);
2029 mode &= RTLD_MODEMASK;
2030 if (*old_obj_tail != NULL) { /* We loaded something new. */
2031 assert(*old_obj_tail == obj);
2032 result = load_needed_objects(obj, RTLD_LO_DLOPEN);
2033 init_dag(obj);
2034 if (result != -1)
2035 result = rtld_verify_versions(&obj->dagmembers);
2036 if (result != -1 && ld_tracing)
2037 goto trace;
2038 if (result == -1 ||
2039 (relocate_objects(obj, mode == RTLD_NOW, &obj_rtld)) == -1) {
2040 obj->dl_refcount--;
2041 unref_dag(obj);
2042 if (obj->refcount == 0)
2043 unload_object(obj);
2044 obj = NULL;
2045 } else {
2046 /* Make list of init functions to call. */
2047 initlist_add_objects(obj, &obj->next, &initlist);
2048 }
2049 } else {
2050
2048 /* Bump the reference counts for objects on this DAG. */
2049 ref_dag(obj);
2051 /*
2052 * Bump the reference counts for objects on this DAG. If
2053 * this is the first dlopen() call for the object that was
2054 * already loaded as a dependency, initialize the dag
2055 * starting at it.
2056 */
2057 if (obj->dl_refcount == 1)
2058 init_dag(obj);
2059 else
2060 ref_dag(obj);
2050
2051 if (ld_tracing)
2052 goto trace;
2053 }
2054 if (obj != NULL && (nodelete || obj->z_nodelete) && !obj->ref_nodel) {
2055 dbg("obj %s nodelete", obj->path);
2056 ref_dag(obj);
2057 obj->z_nodelete = obj->ref_nodel = true;
2058 }
2059 }
2060
2061 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
2062 name);
2063 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
2064
2065 /* Call the init functions. */
2066 objlist_call_init(&initlist, &lockstate);
2067 objlist_clear(&initlist);
2068 wlock_release(rtld_bind_lock, lockstate);
2069 return obj;
2070trace:
2071 trace_loaded_objects(obj);
2072 wlock_release(rtld_bind_lock, lockstate);
2073 exit(0);
2074}
2075
2076static void *
2077do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
2078 int flags)
2079{
2080 DoneList donelist;
2081 const Obj_Entry *obj, *defobj;
2082 const Elf_Sym *def, *symp;
2083 unsigned long hash;
2084 int lockstate;
2085
2086 hash = elf_hash(name);
2087 def = NULL;
2088 defobj = NULL;
2089 flags |= SYMLOOK_IN_PLT;
2090
2091 lockstate = rlock_acquire(rtld_bind_lock);
2092 if (handle == NULL || handle == RTLD_NEXT ||
2093 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
2094
2095 if ((obj = obj_from_addr(retaddr)) == NULL) {
2096 _rtld_error("Cannot determine caller's shared object");
2097 rlock_release(rtld_bind_lock, lockstate);
2098 return NULL;
2099 }
2100 if (handle == NULL) { /* Just the caller's shared object. */
2101 def = symlook_obj(name, hash, obj, ve, flags);
2102 defobj = obj;
2103 } else if (handle == RTLD_NEXT || /* Objects after caller's */
2104 handle == RTLD_SELF) { /* ... caller included */
2105 if (handle == RTLD_NEXT)
2106 obj = obj->next;
2107 for (; obj != NULL; obj = obj->next) {
2108 if ((symp = symlook_obj(name, hash, obj, ve, flags)) != NULL) {
2109 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2110 def = symp;
2111 defobj = obj;
2112 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2113 break;
2114 }
2115 }
2116 }
2117 /*
2118 * Search the dynamic linker itself, and possibly resolve the
2119 * symbol from there. This is how the application links to
2120 * dynamic linker services such as dlopen.
2121 */
2122 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2123 symp = symlook_obj(name, hash, &obj_rtld, ve, flags);
2124 if (symp != NULL) {
2125 def = symp;
2126 defobj = &obj_rtld;
2127 }
2128 }
2129 } else {
2130 assert(handle == RTLD_DEFAULT);
2131 def = symlook_default(name, hash, obj, &defobj, ve, flags);
2132 }
2133 } else {
2134 if ((obj = dlcheck(handle)) == NULL) {
2135 rlock_release(rtld_bind_lock, lockstate);
2136 return NULL;
2137 }
2138
2139 donelist_init(&donelist);
2140 if (obj->mainprog) {
2141 /* Search main program and all libraries loaded by it. */
2142 def = symlook_list(name, hash, &list_main, &defobj, ve, flags,
2143 &donelist);
2144
2145 /*
2146 * We do not distinguish between 'main' object and global scope.
2147 * If symbol is not defined by objects loaded at startup, continue
2148 * search among dynamically loaded objects with RTLD_GLOBAL
2149 * scope.
2150 */
2151 if (def == NULL)
2152 def = symlook_list(name, hash, &list_global, &defobj, ve,
2153 flags, &donelist);
2154 } else {
2155 Needed_Entry fake;
2156
2157 /* Search the whole DAG rooted at the given object. */
2158 fake.next = NULL;
2159 fake.obj = (Obj_Entry *)obj;
2160 fake.name = 0;
2161 def = symlook_needed(name, hash, &fake, &defobj, ve, flags,
2162 &donelist);
2163 }
2164 }
2165
2166 if (def != NULL) {
2167 rlock_release(rtld_bind_lock, lockstate);
2168
2169 /*
2170 * The value required by the caller is derived from the value
2171 * of the symbol. For the ia64 architecture, we need to
2172 * construct a function descriptor which the caller can use to
2173 * call the function with the right 'gp' value. For other
2174 * architectures and for non-functions, the value is simply
2175 * the relocated value of the symbol.
2176 */
2177 if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
2178 return make_function_pointer(def, defobj);
2179 else
2180 return defobj->relocbase + def->st_value;
2181 }
2182
2183 _rtld_error("Undefined symbol \"%s\"", name);
2184 rlock_release(rtld_bind_lock, lockstate);
2185 return NULL;
2186}
2187
2188void *
2189dlsym(void *handle, const char *name)
2190{
2191 return do_dlsym(handle, name, __builtin_return_address(0), NULL,
2192 SYMLOOK_DLSYM);
2193}
2194
2195dlfunc_t
2196dlfunc(void *handle, const char *name)
2197{
2198 union {
2199 void *d;
2200 dlfunc_t f;
2201 } rv;
2202
2203 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
2204 SYMLOOK_DLSYM);
2205 return (rv.f);
2206}
2207
2208void *
2209dlvsym(void *handle, const char *name, const char *version)
2210{
2211 Ver_Entry ventry;
2212
2213 ventry.name = version;
2214 ventry.file = NULL;
2215 ventry.hash = elf_hash(version);
2216 ventry.flags= 0;
2217 return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
2218 SYMLOOK_DLSYM);
2219}
2220
2221int
2222_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
2223{
2224 const Obj_Entry *obj;
2225 int lockstate;
2226
2227 lockstate = rlock_acquire(rtld_bind_lock);
2228 obj = obj_from_addr(addr);
2229 if (obj == NULL) {
2230 _rtld_error("No shared object contains address");
2231 rlock_release(rtld_bind_lock, lockstate);
2232 return (0);
2233 }
2234 rtld_fill_dl_phdr_info(obj, phdr_info);
2235 rlock_release(rtld_bind_lock, lockstate);
2236 return (1);
2237}
2238
2239int
2240dladdr(const void *addr, Dl_info *info)
2241{
2242 const Obj_Entry *obj;
2243 const Elf_Sym *def;
2244 void *symbol_addr;
2245 unsigned long symoffset;
2246 int lockstate;
2247
2248 lockstate = rlock_acquire(rtld_bind_lock);
2249 obj = obj_from_addr(addr);
2250 if (obj == NULL) {
2251 _rtld_error("No shared object contains address");
2252 rlock_release(rtld_bind_lock, lockstate);
2253 return 0;
2254 }
2255 info->dli_fname = obj->path;
2256 info->dli_fbase = obj->mapbase;
2257 info->dli_saddr = (void *)0;
2258 info->dli_sname = NULL;
2259
2260 /*
2261 * Walk the symbol list looking for the symbol whose address is
2262 * closest to the address sent in.
2263 */
2264 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
2265 def = obj->symtab + symoffset;
2266
2267 /*
2268 * For skip the symbol if st_shndx is either SHN_UNDEF or
2269 * SHN_COMMON.
2270 */
2271 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
2272 continue;
2273
2274 /*
2275 * If the symbol is greater than the specified address, or if it
2276 * is further away from addr than the current nearest symbol,
2277 * then reject it.
2278 */
2279 symbol_addr = obj->relocbase + def->st_value;
2280 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
2281 continue;
2282
2283 /* Update our idea of the nearest symbol. */
2284 info->dli_sname = obj->strtab + def->st_name;
2285 info->dli_saddr = symbol_addr;
2286
2287 /* Exact match? */
2288 if (info->dli_saddr == addr)
2289 break;
2290 }
2291 rlock_release(rtld_bind_lock, lockstate);
2292 return 1;
2293}
2294
2295int
2296dlinfo(void *handle, int request, void *p)
2297{
2298 const Obj_Entry *obj;
2299 int error, lockstate;
2300
2301 lockstate = rlock_acquire(rtld_bind_lock);
2302
2303 if (handle == NULL || handle == RTLD_SELF) {
2304 void *retaddr;
2305
2306 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2307 if ((obj = obj_from_addr(retaddr)) == NULL)
2308 _rtld_error("Cannot determine caller's shared object");
2309 } else
2310 obj = dlcheck(handle);
2311
2312 if (obj == NULL) {
2313 rlock_release(rtld_bind_lock, lockstate);
2314 return (-1);
2315 }
2316
2317 error = 0;
2318 switch (request) {
2319 case RTLD_DI_LINKMAP:
2320 *((struct link_map const **)p) = &obj->linkmap;
2321 break;
2322 case RTLD_DI_ORIGIN:
2323 error = rtld_dirname(obj->path, p);
2324 break;
2325
2326 case RTLD_DI_SERINFOSIZE:
2327 case RTLD_DI_SERINFO:
2328 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2329 break;
2330
2331 default:
2332 _rtld_error("Invalid request %d passed to dlinfo()", request);
2333 error = -1;
2334 }
2335
2336 rlock_release(rtld_bind_lock, lockstate);
2337
2338 return (error);
2339}
2340
2341static void
2342rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
2343{
2344
2345 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
2346 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ?
2347 STAILQ_FIRST(&obj->names)->name : obj->path;
2348 phdr_info->dlpi_phdr = obj->phdr;
2349 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
2350 phdr_info->dlpi_tls_modid = obj->tlsindex;
2351 phdr_info->dlpi_tls_data = obj->tlsinit;
2352 phdr_info->dlpi_adds = obj_loads;
2353 phdr_info->dlpi_subs = obj_loads - obj_count;
2354}
2355
2356int
2357dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
2358{
2359 struct dl_phdr_info phdr_info;
2360 const Obj_Entry *obj;
2361 int error, bind_lockstate, phdr_lockstate;
2362
2363 phdr_lockstate = wlock_acquire(rtld_phdr_lock);
2364 bind_lockstate = rlock_acquire(rtld_bind_lock);
2365
2366 error = 0;
2367
2368 for (obj = obj_list; obj != NULL; obj = obj->next) {
2369 rtld_fill_dl_phdr_info(obj, &phdr_info);
2370 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
2371 break;
2372
2373 }
2374 rlock_release(rtld_bind_lock, bind_lockstate);
2375 wlock_release(rtld_phdr_lock, phdr_lockstate);
2376
2377 return (error);
2378}
2379
2380struct fill_search_info_args {
2381 int request;
2382 unsigned int flags;
2383 Dl_serinfo *serinfo;
2384 Dl_serpath *serpath;
2385 char *strspace;
2386};
2387
2388static void *
2389fill_search_info(const char *dir, size_t dirlen, void *param)
2390{
2391 struct fill_search_info_args *arg;
2392
2393 arg = param;
2394
2395 if (arg->request == RTLD_DI_SERINFOSIZE) {
2396 arg->serinfo->dls_cnt ++;
2397 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1;
2398 } else {
2399 struct dl_serpath *s_entry;
2400
2401 s_entry = arg->serpath;
2402 s_entry->dls_name = arg->strspace;
2403 s_entry->dls_flags = arg->flags;
2404
2405 strncpy(arg->strspace, dir, dirlen);
2406 arg->strspace[dirlen] = '\0';
2407
2408 arg->strspace += dirlen + 1;
2409 arg->serpath++;
2410 }
2411
2412 return (NULL);
2413}
2414
2415static int
2416do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2417{
2418 struct dl_serinfo _info;
2419 struct fill_search_info_args args;
2420
2421 args.request = RTLD_DI_SERINFOSIZE;
2422 args.serinfo = &_info;
2423
2424 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2425 _info.dls_cnt = 0;
2426
2427 path_enumerate(ld_library_path, fill_search_info, &args);
2428 path_enumerate(obj->rpath, fill_search_info, &args);
2429 path_enumerate(gethints(), fill_search_info, &args);
2430 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2431
2432
2433 if (request == RTLD_DI_SERINFOSIZE) {
2434 info->dls_size = _info.dls_size;
2435 info->dls_cnt = _info.dls_cnt;
2436 return (0);
2437 }
2438
2439 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2440 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2441 return (-1);
2442 }
2443
2444 args.request = RTLD_DI_SERINFO;
2445 args.serinfo = info;
2446 args.serpath = &info->dls_serpath[0];
2447 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2448
2449 args.flags = LA_SER_LIBPATH;
2450 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2451 return (-1);
2452
2453 args.flags = LA_SER_RUNPATH;
2454 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2455 return (-1);
2456
2457 args.flags = LA_SER_CONFIG;
2458 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2459 return (-1);
2460
2461 args.flags = LA_SER_DEFAULT;
2462 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2463 return (-1);
2464 return (0);
2465}
2466
2467static int
2468rtld_dirname(const char *path, char *bname)
2469{
2470 const char *endp;
2471
2472 /* Empty or NULL string gets treated as "." */
2473 if (path == NULL || *path == '\0') {
2474 bname[0] = '.';
2475 bname[1] = '\0';
2476 return (0);
2477 }
2478
2479 /* Strip trailing slashes */
2480 endp = path + strlen(path) - 1;
2481 while (endp > path && *endp == '/')
2482 endp--;
2483
2484 /* Find the start of the dir */
2485 while (endp > path && *endp != '/')
2486 endp--;
2487
2488 /* Either the dir is "/" or there are no slashes */
2489 if (endp == path) {
2490 bname[0] = *endp == '/' ? '/' : '.';
2491 bname[1] = '\0';
2492 return (0);
2493 } else {
2494 do {
2495 endp--;
2496 } while (endp > path && *endp == '/');
2497 }
2498
2499 if (endp - path + 2 > PATH_MAX)
2500 {
2501 _rtld_error("Filename is too long: %s", path);
2502 return(-1);
2503 }
2504
2505 strncpy(bname, path, endp - path + 1);
2506 bname[endp - path + 1] = '\0';
2507 return (0);
2508}
2509
2510static int
2511rtld_dirname_abs(const char *path, char *base)
2512{
2513 char base_rel[PATH_MAX];
2514
2515 if (rtld_dirname(path, base) == -1)
2516 return (-1);
2517 if (base[0] == '/')
2518 return (0);
2519 if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
2520 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
2521 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
2522 return (-1);
2523 strcpy(base, base_rel);
2524 return (0);
2525}
2526
2527static void
2528linkmap_add(Obj_Entry *obj)
2529{
2530 struct link_map *l = &obj->linkmap;
2531 struct link_map *prev;
2532
2533 obj->linkmap.l_name = obj->path;
2534 obj->linkmap.l_addr = obj->mapbase;
2535 obj->linkmap.l_ld = obj->dynamic;
2536#ifdef __mips__
2537 /* GDB needs load offset on MIPS to use the symbols */
2538 obj->linkmap.l_offs = obj->relocbase;
2539#endif
2540
2541 if (r_debug.r_map == NULL) {
2542 r_debug.r_map = l;
2543 return;
2544 }
2545
2546 /*
2547 * Scan to the end of the list, but not past the entry for the
2548 * dynamic linker, which we want to keep at the very end.
2549 */
2550 for (prev = r_debug.r_map;
2551 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2552 prev = prev->l_next)
2553 ;
2554
2555 /* Link in the new entry. */
2556 l->l_prev = prev;
2557 l->l_next = prev->l_next;
2558 if (l->l_next != NULL)
2559 l->l_next->l_prev = l;
2560 prev->l_next = l;
2561}
2562
2563static void
2564linkmap_delete(Obj_Entry *obj)
2565{
2566 struct link_map *l = &obj->linkmap;
2567
2568 if (l->l_prev == NULL) {
2569 if ((r_debug.r_map = l->l_next) != NULL)
2570 l->l_next->l_prev = NULL;
2571 return;
2572 }
2573
2574 if ((l->l_prev->l_next = l->l_next) != NULL)
2575 l->l_next->l_prev = l->l_prev;
2576}
2577
2578/*
2579 * Function for the debugger to set a breakpoint on to gain control.
2580 *
2581 * The two parameters allow the debugger to easily find and determine
2582 * what the runtime loader is doing and to whom it is doing it.
2583 *
2584 * When the loadhook trap is hit (r_debug_state, set at program
2585 * initialization), the arguments can be found on the stack:
2586 *
2587 * +8 struct link_map *m
2588 * +4 struct r_debug *rd
2589 * +0 RetAddr
2590 */
2591void
2592r_debug_state(struct r_debug* rd, struct link_map *m)
2593{
2594}
2595
2596/*
2597 * Get address of the pointer variable in the main program.
2598 */
2599static const void **
2600get_program_var_addr(const char *name)
2601{
2602 const Obj_Entry *obj;
2603 unsigned long hash;
2604
2605 hash = elf_hash(name);
2606 for (obj = obj_main; obj != NULL; obj = obj->next) {
2607 const Elf_Sym *def;
2608
2609 if ((def = symlook_obj(name, hash, obj, NULL, 0)) != NULL) {
2610 const void **addr;
2611
2612 addr = (const void **)(obj->relocbase + def->st_value);
2613 return addr;
2614 }
2615 }
2616 return NULL;
2617}
2618
2619/*
2620 * Set a pointer variable in the main program to the given value. This
2621 * is used to set key variables such as "environ" before any of the
2622 * init functions are called.
2623 */
2624static void
2625set_program_var(const char *name, const void *value)
2626{
2627 const void **addr;
2628
2629 if ((addr = get_program_var_addr(name)) != NULL) {
2630 dbg("\"%s\": *%p <-- %p", name, addr, value);
2631 *addr = value;
2632 }
2633}
2634
2635/*
2636 * Given a symbol name in a referencing object, find the corresponding
2637 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2638 * no definition was found. Returns a pointer to the Obj_Entry of the
2639 * defining object via the reference parameter DEFOBJ_OUT.
2640 */
2641static const Elf_Sym *
2642symlook_default(const char *name, unsigned long hash, const Obj_Entry *refobj,
2643 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags)
2644{
2645 DoneList donelist;
2646 const Elf_Sym *def;
2647 const Elf_Sym *symp;
2648 const Obj_Entry *obj;
2649 const Obj_Entry *defobj;
2650 const Objlist_Entry *elm;
2651 def = NULL;
2652 defobj = NULL;
2653 donelist_init(&donelist);
2654
2655 /* Look first in the referencing object if linked symbolically. */
2656 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
2657 symp = symlook_obj(name, hash, refobj, ventry, flags);
2658 if (symp != NULL) {
2659 def = symp;
2660 defobj = refobj;
2661 }
2662 }
2663
2664 /* Search all objects loaded at program start up. */
2665 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2666 symp = symlook_list(name, hash, &list_main, &obj, ventry, flags,
2667 &donelist);
2668 if (symp != NULL &&
2669 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2670 def = symp;
2671 defobj = obj;
2672 }
2673 }
2674
2675 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2676 STAILQ_FOREACH(elm, &list_global, link) {
2677 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2678 break;
2679 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry,
2680 flags, &donelist);
2681 if (symp != NULL &&
2682 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2683 def = symp;
2684 defobj = obj;
2685 }
2686 }
2687
2688 /* Search all dlopened DAGs containing the referencing object. */
2689 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2690 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2691 break;
2692 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry,
2693 flags, &donelist);
2694 if (symp != NULL &&
2695 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2696 def = symp;
2697 defobj = obj;
2698 }
2699 }
2700
2701 /*
2702 * Search the dynamic linker itself, and possibly resolve the
2703 * symbol from there. This is how the application links to
2704 * dynamic linker services such as dlopen.
2705 */
2706 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2707 symp = symlook_obj(name, hash, &obj_rtld, ventry, flags);
2708 if (symp != NULL) {
2709 def = symp;
2710 defobj = &obj_rtld;
2711 }
2712 }
2713
2714 if (def != NULL)
2715 *defobj_out = defobj;
2716 return def;
2717}
2718
2719static const Elf_Sym *
2720symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
2721 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags,
2722 DoneList *dlp)
2723{
2724 const Elf_Sym *symp;
2725 const Elf_Sym *def;
2726 const Obj_Entry *defobj;
2727 const Objlist_Entry *elm;
2728
2729 def = NULL;
2730 defobj = NULL;
2731 STAILQ_FOREACH(elm, objlist, link) {
2732 if (donelist_check(dlp, elm->obj))
2733 continue;
2734 if ((symp = symlook_obj(name, hash, elm->obj, ventry, flags)) != NULL) {
2735 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2736 def = symp;
2737 defobj = elm->obj;
2738 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2739 break;
2740 }
2741 }
2742 }
2743 if (def != NULL)
2744 *defobj_out = defobj;
2745 return def;
2746}
2747
2748/*
2749 * Search the symbol table of a shared object and all objects needed
2750 * by it for a symbol of the given name. Search order is
2751 * breadth-first. Returns a pointer to the symbol, or NULL if no
2752 * definition was found.
2753 */
2754static const Elf_Sym *
2755symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
2756 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags,
2757 DoneList *dlp)
2758{
2759 const Elf_Sym *def, *def_w;
2760 const Needed_Entry *n;
2761 const Obj_Entry *obj, *defobj, *defobj1;
2762
2763 def = def_w = NULL;
2764 defobj = NULL;
2765 for (n = needed; n != NULL; n = n->next) {
2766 if ((obj = n->obj) == NULL ||
2767 donelist_check(dlp, obj) ||
2768 (def = symlook_obj(name, hash, obj, ventry, flags)) == NULL)
2769 continue;
2770 defobj = obj;
2771 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2772 *defobj_out = defobj;
2773 return (def);
2774 }
2775 }
2776 /*
2777 * There we come when either symbol definition is not found in
2778 * directly needed objects, or found symbol is weak.
2779 */
2780 for (n = needed; n != NULL; n = n->next) {
2781 if ((obj = n->obj) == NULL)
2782 continue;
2783 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
2784 ventry, flags, dlp);
2785 if (def_w == NULL)
2786 continue;
2787 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
2788 def = def_w;
2789 defobj = defobj1;
2790 }
2791 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
2792 break;
2793 }
2794 if (def != NULL)
2795 *defobj_out = defobj;
2796 return (def);
2797}
2798
2799/*
2800 * Search the symbol table of a single shared object for a symbol of
2801 * the given name and version, if requested. Returns a pointer to the
2802 * symbol, or NULL if no definition was found.
2803 *
2804 * The symbol's hash value is passed in for efficiency reasons; that
2805 * eliminates many recomputations of the hash value.
2806 */
2807const Elf_Sym *
2808symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
2809 const Ver_Entry *ventry, int flags)
2810{
2811 unsigned long symnum;
2812 const Elf_Sym *vsymp;
2813 Elf_Versym verndx;
2814 int vcount;
2815
2816 if (obj->buckets == NULL)
2817 return NULL;
2818
2819 vsymp = NULL;
2820 vcount = 0;
2821 symnum = obj->buckets[hash % obj->nbuckets];
2822
2823 for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
2824 const Elf_Sym *symp;
2825 const char *strp;
2826
2827 if (symnum >= obj->nchains)
2828 return NULL; /* Bad object */
2829
2830 symp = obj->symtab + symnum;
2831 strp = obj->strtab + symp->st_name;
2832
2833 switch (ELF_ST_TYPE(symp->st_info)) {
2834 case STT_FUNC:
2835 case STT_NOTYPE:
2836 case STT_OBJECT:
2837 if (symp->st_value == 0)
2838 continue;
2839 /* fallthrough */
2840 case STT_TLS:
2841 if (symp->st_shndx != SHN_UNDEF)
2842 break;
2843#ifndef __mips__
2844 else if (((flags & SYMLOOK_IN_PLT) == 0) &&
2845 (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
2846 break;
2847 /* fallthrough */
2848#endif
2849 default:
2850 continue;
2851 }
2852 if (name[0] != strp[0] || strcmp(name, strp) != 0)
2853 continue;
2854
2855 if (ventry == NULL) {
2856 if (obj->versyms != NULL) {
2857 verndx = VER_NDX(obj->versyms[symnum]);
2858 if (verndx > obj->vernum) {
2859 _rtld_error("%s: symbol %s references wrong version %d",
2860 obj->path, obj->strtab + symnum, verndx);
2861 continue;
2862 }
2863 /*
2864 * If we are not called from dlsym (i.e. this is a normal
2865 * relocation from unversioned binary, accept the symbol
2866 * immediately if it happens to have first version after
2867 * this shared object became versioned. Otherwise, if
2868 * symbol is versioned and not hidden, remember it. If it
2869 * is the only symbol with this name exported by the
2870 * shared object, it will be returned as a match at the
2871 * end of the function. If symbol is global (verndx < 2)
2872 * accept it unconditionally.
2873 */
2874 if ((flags & SYMLOOK_DLSYM) == 0 && verndx == VER_NDX_GIVEN)
2875 return symp;
2876 else if (verndx >= VER_NDX_GIVEN) {
2877 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) {
2878 if (vsymp == NULL)
2879 vsymp = symp;
2880 vcount ++;
2881 }
2882 continue;
2883 }
2884 }
2885 return symp;
2886 } else {
2887 if (obj->versyms == NULL) {
2888 if (object_match_name(obj, ventry->name)) {
2889 _rtld_error("%s: object %s should provide version %s for "
2890 "symbol %s", obj_rtld.path, obj->path, ventry->name,
2891 obj->strtab + symnum);
2892 continue;
2893 }
2894 } else {
2895 verndx = VER_NDX(obj->versyms[symnum]);
2896 if (verndx > obj->vernum) {
2897 _rtld_error("%s: symbol %s references wrong version %d",
2898 obj->path, obj->strtab + symnum, verndx);
2899 continue;
2900 }
2901 if (obj->vertab[verndx].hash != ventry->hash ||
2902 strcmp(obj->vertab[verndx].name, ventry->name)) {
2903 /*
2904 * Version does not match. Look if this is a global symbol
2905 * and if it is not hidden. If global symbol (verndx < 2)
2906 * is available, use it. Do not return symbol if we are
2907 * called by dlvsym, because dlvsym looks for a specific
2908 * version and default one is not what dlvsym wants.
2909 */
2910 if ((flags & SYMLOOK_DLSYM) ||
2911 (obj->versyms[symnum] & VER_NDX_HIDDEN) ||
2912 (verndx >= VER_NDX_GIVEN))
2913 continue;
2914 }
2915 }
2916 return symp;
2917 }
2918 }
2919 return (vcount == 1) ? vsymp : NULL;
2920}
2921
2922static void
2923trace_loaded_objects(Obj_Entry *obj)
2924{
2925 char *fmt1, *fmt2, *fmt, *main_local, *list_containers;
2926 int c;
2927
2928 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
2929 main_local = "";
2930
2931 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL)
2932 fmt1 = "\t%o => %p (%x)\n";
2933
2934 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL)
2935 fmt2 = "\t%o (%x)\n";
2936
2937 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL");
2938
2939 for (; obj; obj = obj->next) {
2940 Needed_Entry *needed;
2941 char *name, *path;
2942 bool is_lib;
2943
2944 if (list_containers && obj->needed != NULL)
2945 printf("%s:\n", obj->path);
2946 for (needed = obj->needed; needed; needed = needed->next) {
2947 if (needed->obj != NULL) {
2948 if (needed->obj->traced && !list_containers)
2949 continue;
2950 needed->obj->traced = true;
2951 path = needed->obj->path;
2952 } else
2953 path = "not found";
2954
2955 name = (char *)obj->strtab + needed->name;
2956 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
2957
2958 fmt = is_lib ? fmt1 : fmt2;
2959 while ((c = *fmt++) != '\0') {
2960 switch (c) {
2961 default:
2962 putchar(c);
2963 continue;
2964 case '\\':
2965 switch (c = *fmt) {
2966 case '\0':
2967 continue;
2968 case 'n':
2969 putchar('\n');
2970 break;
2971 case 't':
2972 putchar('\t');
2973 break;
2974 }
2975 break;
2976 case '%':
2977 switch (c = *fmt) {
2978 case '\0':
2979 continue;
2980 case '%':
2981 default:
2982 putchar(c);
2983 break;
2984 case 'A':
2985 printf("%s", main_local);
2986 break;
2987 case 'a':
2988 printf("%s", obj_main->path);
2989 break;
2990 case 'o':
2991 printf("%s", name);
2992 break;
2993#if 0
2994 case 'm':
2995 printf("%d", sodp->sod_major);
2996 break;
2997 case 'n':
2998 printf("%d", sodp->sod_minor);
2999 break;
3000#endif
3001 case 'p':
3002 printf("%s", path);
3003 break;
3004 case 'x':
3005 printf("%p", needed->obj ? needed->obj->mapbase : 0);
3006 break;
3007 }
3008 break;
3009 }
3010 ++fmt;
3011 }
3012 }
3013 }
3014}
3015
3016/*
3017 * Unload a dlopened object and its dependencies from memory and from
3018 * our data structures. It is assumed that the DAG rooted in the
3019 * object has already been unreferenced, and that the object has a
3020 * reference count of 0.
3021 */
3022static void
3023unload_object(Obj_Entry *root)
3024{
3025 Obj_Entry *obj;
3026 Obj_Entry **linkp;
3027
3028 assert(root->refcount == 0);
3029
3030 /*
3031 * Pass over the DAG removing unreferenced objects from
3032 * appropriate lists.
3033 */
3034 unlink_object(root);
3035
3036 /* Unmap all objects that are no longer referenced. */
3037 linkp = &obj_list->next;
3038 while ((obj = *linkp) != NULL) {
3039 if (obj->refcount == 0) {
3040 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
3041 obj->path);
3042 dbg("unloading \"%s\"", obj->path);
3043 munmap(obj->mapbase, obj->mapsize);
3044 linkmap_delete(obj);
3045 *linkp = obj->next;
3046 obj_count--;
3047 obj_free(obj);
3048 } else
3049 linkp = &obj->next;
3050 }
3051 obj_tail = linkp;
3052}
3053
3054static void
3055unlink_object(Obj_Entry *root)
3056{
3057 Objlist_Entry *elm;
3058
3059 if (root->refcount == 0) {
3060 /* Remove the object from the RTLD_GLOBAL list. */
3061 objlist_remove(&list_global, root);
3062
3063 /* Remove the object from all objects' DAG lists. */
3064 STAILQ_FOREACH(elm, &root->dagmembers, link) {
3065 objlist_remove(&elm->obj->dldags, root);
3066 if (elm->obj != root)
3067 unlink_object(elm->obj);
3068 }
3069 }
3070}
3071
3072static void
3073ref_dag(Obj_Entry *root)
3074{
3075 Objlist_Entry *elm;
3076
3077 STAILQ_FOREACH(elm, &root->dagmembers, link)
3078 elm->obj->refcount++;
3079}
3080
3081static void
3082unref_dag(Obj_Entry *root)
3083{
3084 Objlist_Entry *elm;
3085
3086 STAILQ_FOREACH(elm, &root->dagmembers, link)
3087 elm->obj->refcount--;
3088}
3089
3090/*
3091 * Common code for MD __tls_get_addr().
3092 */
3093void *
3094tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset)
3095{
3096 Elf_Addr* dtv = *dtvp;
3097 int lockstate;
3098
3099 /* Check dtv generation in case new modules have arrived */
3100 if (dtv[0] != tls_dtv_generation) {
3101 Elf_Addr* newdtv;
3102 int to_copy;
3103
3104 lockstate = wlock_acquire(rtld_bind_lock);
3105 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
3106 to_copy = dtv[1];
3107 if (to_copy > tls_max_index)
3108 to_copy = tls_max_index;
3109 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
3110 newdtv[0] = tls_dtv_generation;
3111 newdtv[1] = tls_max_index;
3112 free(dtv);
3113 wlock_release(rtld_bind_lock, lockstate);
3114 *dtvp = newdtv;
3115 }
3116
3117 /* Dynamically allocate module TLS if necessary */
3118 if (!dtv[index + 1]) {
3119 /* Signal safe, wlock will block out signals. */
3120 lockstate = wlock_acquire(rtld_bind_lock);
3121 if (!dtv[index + 1])
3122 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
3123 wlock_release(rtld_bind_lock, lockstate);
3124 }
3125 return (void*) (dtv[index + 1] + offset);
3126}
3127
3128/* XXX not sure what variants to use for arm. */
3129
3130#if defined(__ia64__) || defined(__powerpc__)
3131
3132/*
3133 * Allocate Static TLS using the Variant I method.
3134 */
3135void *
3136allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
3137{
3138 Obj_Entry *obj;
3139 char *tcb;
3140 Elf_Addr **tls;
3141 Elf_Addr *dtv;
3142 Elf_Addr addr;
3143 int i;
3144
3145 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
3146 return (oldtcb);
3147
3148 assert(tcbsize >= TLS_TCB_SIZE);
3149 tcb = calloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
3150 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
3151
3152 if (oldtcb != NULL) {
3153 memcpy(tls, oldtcb, tls_static_space);
3154 free(oldtcb);
3155
3156 /* Adjust the DTV. */
3157 dtv = tls[0];
3158 for (i = 0; i < dtv[1]; i++) {
3159 if (dtv[i+2] >= (Elf_Addr)oldtcb &&
3160 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
3161 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
3162 }
3163 }
3164 } else {
3165 dtv = calloc(tls_max_index + 2, sizeof(Elf_Addr));
3166 tls[0] = dtv;
3167 dtv[0] = tls_dtv_generation;
3168 dtv[1] = tls_max_index;
3169
3170 for (obj = objs; obj; obj = obj->next) {
3171 if (obj->tlsoffset > 0) {
3172 addr = (Elf_Addr)tls + obj->tlsoffset;
3173 if (obj->tlsinitsize > 0)
3174 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
3175 if (obj->tlssize > obj->tlsinitsize)
3176 memset((void*) (addr + obj->tlsinitsize), 0,
3177 obj->tlssize - obj->tlsinitsize);
3178 dtv[obj->tlsindex + 1] = addr;
3179 }
3180 }
3181 }
3182
3183 return (tcb);
3184}
3185
3186void
3187free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
3188{
3189 Elf_Addr *dtv;
3190 Elf_Addr tlsstart, tlsend;
3191 int dtvsize, i;
3192
3193 assert(tcbsize >= TLS_TCB_SIZE);
3194
3195 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
3196 tlsend = tlsstart + tls_static_space;
3197
3198 dtv = *(Elf_Addr **)tlsstart;
3199 dtvsize = dtv[1];
3200 for (i = 0; i < dtvsize; i++) {
3201 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
3202 free((void*)dtv[i+2]);
3203 }
3204 }
3205 free(dtv);
3206 free(tcb);
3207}
3208
3209#endif
3210
3211#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \
3212 defined(__arm__) || defined(__mips__)
3213
3214/*
3215 * Allocate Static TLS using the Variant II method.
3216 */
3217void *
3218allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
3219{
3220 Obj_Entry *obj;
3221 size_t size;
3222 char *tls;
3223 Elf_Addr *dtv, *olddtv;
3224 Elf_Addr segbase, oldsegbase, addr;
3225 int i;
3226
3227 size = round(tls_static_space, tcbalign);
3228
3229 assert(tcbsize >= 2*sizeof(Elf_Addr));
3230 tls = calloc(1, size + tcbsize);
3231 dtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
3232
3233 segbase = (Elf_Addr)(tls + size);
3234 ((Elf_Addr*)segbase)[0] = segbase;
3235 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
3236
3237 dtv[0] = tls_dtv_generation;
3238 dtv[1] = tls_max_index;
3239
3240 if (oldtls) {
3241 /*
3242 * Copy the static TLS block over whole.
3243 */
3244 oldsegbase = (Elf_Addr) oldtls;
3245 memcpy((void *)(segbase - tls_static_space),
3246 (const void *)(oldsegbase - tls_static_space),
3247 tls_static_space);
3248
3249 /*
3250 * If any dynamic TLS blocks have been created tls_get_addr(),
3251 * move them over.
3252 */
3253 olddtv = ((Elf_Addr**)oldsegbase)[1];
3254 for (i = 0; i < olddtv[1]; i++) {
3255 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
3256 dtv[i+2] = olddtv[i+2];
3257 olddtv[i+2] = 0;
3258 }
3259 }
3260
3261 /*
3262 * We assume that this block was the one we created with
3263 * allocate_initial_tls().
3264 */
3265 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
3266 } else {
3267 for (obj = objs; obj; obj = obj->next) {
3268 if (obj->tlsoffset) {
3269 addr = segbase - obj->tlsoffset;
3270 memset((void*) (addr + obj->tlsinitsize),
3271 0, obj->tlssize - obj->tlsinitsize);
3272 if (obj->tlsinit)
3273 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
3274 dtv[obj->tlsindex + 1] = addr;
3275 }
3276 }
3277 }
3278
3279 return (void*) segbase;
3280}
3281
3282void
3283free_tls(void *tls, size_t tcbsize, size_t tcbalign)
3284{
3285 size_t size;
3286 Elf_Addr* dtv;
3287 int dtvsize, i;
3288 Elf_Addr tlsstart, tlsend;
3289
3290 /*
3291 * Figure out the size of the initial TLS block so that we can
3292 * find stuff which ___tls_get_addr() allocated dynamically.
3293 */
3294 size = round(tls_static_space, tcbalign);
3295
3296 dtv = ((Elf_Addr**)tls)[1];
3297 dtvsize = dtv[1];
3298 tlsend = (Elf_Addr) tls;
3299 tlsstart = tlsend - size;
3300 for (i = 0; i < dtvsize; i++) {
3301 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) {
3302 free((void*) dtv[i+2]);
3303 }
3304 }
3305
3306 free((void*) tlsstart);
3307 free((void*) dtv);
3308}
3309
3310#endif
3311
3312/*
3313 * Allocate TLS block for module with given index.
3314 */
3315void *
3316allocate_module_tls(int index)
3317{
3318 Obj_Entry* obj;
3319 char* p;
3320
3321 for (obj = obj_list; obj; obj = obj->next) {
3322 if (obj->tlsindex == index)
3323 break;
3324 }
3325 if (!obj) {
3326 _rtld_error("Can't find module with TLS index %d", index);
3327 die();
3328 }
3329
3330 p = malloc(obj->tlssize);
3331 if (p == NULL) {
3332 _rtld_error("Cannot allocate TLS block for index %d", index);
3333 die();
3334 }
3335 memcpy(p, obj->tlsinit, obj->tlsinitsize);
3336 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
3337
3338 return p;
3339}
3340
3341bool
3342allocate_tls_offset(Obj_Entry *obj)
3343{
3344 size_t off;
3345
3346 if (obj->tls_done)
3347 return true;
3348
3349 if (obj->tlssize == 0) {
3350 obj->tls_done = true;
3351 return true;
3352 }
3353
3354 if (obj->tlsindex == 1)
3355 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
3356 else
3357 off = calculate_tls_offset(tls_last_offset, tls_last_size,
3358 obj->tlssize, obj->tlsalign);
3359
3360 /*
3361 * If we have already fixed the size of the static TLS block, we
3362 * must stay within that size. When allocating the static TLS, we
3363 * leave a small amount of space spare to be used for dynamically
3364 * loading modules which use static TLS.
3365 */
3366 if (tls_static_space) {
3367 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
3368 return false;
3369 }
3370
3371 tls_last_offset = obj->tlsoffset = off;
3372 tls_last_size = obj->tlssize;
3373 obj->tls_done = true;
3374
3375 return true;
3376}
3377
3378void
3379free_tls_offset(Obj_Entry *obj)
3380{
3381
3382 /*
3383 * If we were the last thing to allocate out of the static TLS
3384 * block, we give our space back to the 'allocator'. This is a
3385 * simplistic workaround to allow libGL.so.1 to be loaded and
3386 * unloaded multiple times.
3387 */
3388 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
3389 == calculate_tls_end(tls_last_offset, tls_last_size)) {
3390 tls_last_offset -= obj->tlssize;
3391 tls_last_size = 0;
3392 }
3393}
3394
3395void *
3396_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
3397{
3398 void *ret;
3399 int lockstate;
3400
3401 lockstate = wlock_acquire(rtld_bind_lock);
3402 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign);
3403 wlock_release(rtld_bind_lock, lockstate);
3404 return (ret);
3405}
3406
3407void
3408_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
3409{
3410 int lockstate;
3411
3412 lockstate = wlock_acquire(rtld_bind_lock);
3413 free_tls(tcb, tcbsize, tcbalign);
3414 wlock_release(rtld_bind_lock, lockstate);
3415}
3416
3417static void
3418object_add_name(Obj_Entry *obj, const char *name)
3419{
3420 Name_Entry *entry;
3421 size_t len;
3422
3423 len = strlen(name);
3424 entry = malloc(sizeof(Name_Entry) + len);
3425
3426 if (entry != NULL) {
3427 strcpy(entry->name, name);
3428 STAILQ_INSERT_TAIL(&obj->names, entry, link);
3429 }
3430}
3431
3432static int
3433object_match_name(const Obj_Entry *obj, const char *name)
3434{
3435 Name_Entry *entry;
3436
3437 STAILQ_FOREACH(entry, &obj->names, link) {
3438 if (strcmp(name, entry->name) == 0)
3439 return (1);
3440 }
3441 return (0);
3442}
3443
3444static Obj_Entry *
3445locate_dependency(const Obj_Entry *obj, const char *name)
3446{
3447 const Objlist_Entry *entry;
3448 const Needed_Entry *needed;
3449
3450 STAILQ_FOREACH(entry, &list_main, link) {
3451 if (object_match_name(entry->obj, name))
3452 return entry->obj;
3453 }
3454
3455 for (needed = obj->needed; needed != NULL; needed = needed->next) {
3456 if (needed->obj == NULL)
3457 continue;
3458 if (object_match_name(needed->obj, name))
3459 return needed->obj;
3460 }
3461 _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
3462 obj->path, name);
3463 die();
3464}
3465
3466static int
3467check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
3468 const Elf_Vernaux *vna)
3469{
3470 const Elf_Verdef *vd;
3471 const char *vername;
3472
3473 vername = refobj->strtab + vna->vna_name;
3474 vd = depobj->verdef;
3475 if (vd == NULL) {
3476 _rtld_error("%s: version %s required by %s not defined",
3477 depobj->path, vername, refobj->path);
3478 return (-1);
3479 }
3480 for (;;) {
3481 if (vd->vd_version != VER_DEF_CURRENT) {
3482 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
3483 depobj->path, vd->vd_version);
3484 return (-1);
3485 }
3486 if (vna->vna_hash == vd->vd_hash) {
3487 const Elf_Verdaux *aux = (const Elf_Verdaux *)
3488 ((char *)vd + vd->vd_aux);
3489 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
3490 return (0);
3491 }
3492 if (vd->vd_next == 0)
3493 break;
3494 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3495 }
3496 if (vna->vna_flags & VER_FLG_WEAK)
3497 return (0);
3498 _rtld_error("%s: version %s required by %s not found",
3499 depobj->path, vername, refobj->path);
3500 return (-1);
3501}
3502
3503static int
3504rtld_verify_object_versions(Obj_Entry *obj)
3505{
3506 const Elf_Verneed *vn;
3507 const Elf_Verdef *vd;
3508 const Elf_Verdaux *vda;
3509 const Elf_Vernaux *vna;
3510 const Obj_Entry *depobj;
3511 int maxvernum, vernum;
3512
3513 maxvernum = 0;
3514 /*
3515 * Walk over defined and required version records and figure out
3516 * max index used by any of them. Do very basic sanity checking
3517 * while there.
3518 */
3519 vn = obj->verneed;
3520 while (vn != NULL) {
3521 if (vn->vn_version != VER_NEED_CURRENT) {
3522 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
3523 obj->path, vn->vn_version);
3524 return (-1);
3525 }
3526 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
3527 for (;;) {
3528 vernum = VER_NEED_IDX(vna->vna_other);
3529 if (vernum > maxvernum)
3530 maxvernum = vernum;
3531 if (vna->vna_next == 0)
3532 break;
3533 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
3534 }
3535 if (vn->vn_next == 0)
3536 break;
3537 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
3538 }
3539
3540 vd = obj->verdef;
3541 while (vd != NULL) {
3542 if (vd->vd_version != VER_DEF_CURRENT) {
3543 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
3544 obj->path, vd->vd_version);
3545 return (-1);
3546 }
3547 vernum = VER_DEF_IDX(vd->vd_ndx);
3548 if (vernum > maxvernum)
3549 maxvernum = vernum;
3550 if (vd->vd_next == 0)
3551 break;
3552 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3553 }
3554
3555 if (maxvernum == 0)
3556 return (0);
3557
3558 /*
3559 * Store version information in array indexable by version index.
3560 * Verify that object version requirements are satisfied along the
3561 * way.
3562 */
3563 obj->vernum = maxvernum + 1;
3564 obj->vertab = calloc(obj->vernum, sizeof(Ver_Entry));
3565
3566 vd = obj->verdef;
3567 while (vd != NULL) {
3568 if ((vd->vd_flags & VER_FLG_BASE) == 0) {
3569 vernum = VER_DEF_IDX(vd->vd_ndx);
3570 assert(vernum <= maxvernum);
3571 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
3572 obj->vertab[vernum].hash = vd->vd_hash;
3573 obj->vertab[vernum].name = obj->strtab + vda->vda_name;
3574 obj->vertab[vernum].file = NULL;
3575 obj->vertab[vernum].flags = 0;
3576 }
3577 if (vd->vd_next == 0)
3578 break;
3579 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3580 }
3581
3582 vn = obj->verneed;
3583 while (vn != NULL) {
3584 depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
3585 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
3586 for (;;) {
3587 if (check_object_provided_version(obj, depobj, vna))
3588 return (-1);
3589 vernum = VER_NEED_IDX(vna->vna_other);
3590 assert(vernum <= maxvernum);
3591 obj->vertab[vernum].hash = vna->vna_hash;
3592 obj->vertab[vernum].name = obj->strtab + vna->vna_name;
3593 obj->vertab[vernum].file = obj->strtab + vn->vn_file;
3594 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
3595 VER_INFO_HIDDEN : 0;
3596 if (vna->vna_next == 0)
3597 break;
3598 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
3599 }
3600 if (vn->vn_next == 0)
3601 break;
3602 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
3603 }
3604 return 0;
3605}
3606
3607static int
3608rtld_verify_versions(const Objlist *objlist)
3609{
3610 Objlist_Entry *entry;
3611 int rc;
3612
3613 rc = 0;
3614 STAILQ_FOREACH(entry, objlist, link) {
3615 /*
3616 * Skip dummy objects or objects that have their version requirements
3617 * already checked.
3618 */
3619 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
3620 continue;
3621 if (rtld_verify_object_versions(entry->obj) == -1) {
3622 rc = -1;
3623 if (ld_tracing == NULL)
3624 break;
3625 }
3626 }
3627 if (rc == 0 || ld_tracing != NULL)
3628 rc = rtld_verify_object_versions(&obj_rtld);
3629 return rc;
3630}
3631
3632const Ver_Entry *
3633fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
3634{
3635 Elf_Versym vernum;
3636
3637 if (obj->vertab) {
3638 vernum = VER_NDX(obj->versyms[symnum]);
3639 if (vernum >= obj->vernum) {
3640 _rtld_error("%s: symbol %s has wrong verneed value %d",
3641 obj->path, obj->strtab + symnum, vernum);
3642 } else if (obj->vertab[vernum].hash != 0) {
3643 return &obj->vertab[vernum];
3644 }
3645 }
3646 return NULL;
3647}
3648
3649/*
3650 * Overrides for libc_pic-provided functions.
3651 */
3652
3653int
3654__getosreldate(void)
3655{
3656 size_t len;
3657 int oid[2];
3658 int error, osrel;
3659
3660 if (osreldate != 0)
3661 return (osreldate);
3662
3663 oid[0] = CTL_KERN;
3664 oid[1] = KERN_OSRELDATE;
3665 osrel = 0;
3666 len = sizeof(osrel);
3667 error = sysctl(oid, 2, &osrel, &len, NULL, 0);
3668 if (error == 0 && osrel > 0 && len == sizeof(osrel))
3669 osreldate = osrel;
3670 return (osreldate);
3671}
3672
3673/*
3674 * No unresolved symbols for rtld.
3675 */
3676void
3677__pthread_cxa_finalize(struct dl_phdr_info *a)
3678{
3679}
2061
2062 if (ld_tracing)
2063 goto trace;
2064 }
2065 if (obj != NULL && (nodelete || obj->z_nodelete) && !obj->ref_nodel) {
2066 dbg("obj %s nodelete", obj->path);
2067 ref_dag(obj);
2068 obj->z_nodelete = obj->ref_nodel = true;
2069 }
2070 }
2071
2072 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
2073 name);
2074 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
2075
2076 /* Call the init functions. */
2077 objlist_call_init(&initlist, &lockstate);
2078 objlist_clear(&initlist);
2079 wlock_release(rtld_bind_lock, lockstate);
2080 return obj;
2081trace:
2082 trace_loaded_objects(obj);
2083 wlock_release(rtld_bind_lock, lockstate);
2084 exit(0);
2085}
2086
2087static void *
2088do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
2089 int flags)
2090{
2091 DoneList donelist;
2092 const Obj_Entry *obj, *defobj;
2093 const Elf_Sym *def, *symp;
2094 unsigned long hash;
2095 int lockstate;
2096
2097 hash = elf_hash(name);
2098 def = NULL;
2099 defobj = NULL;
2100 flags |= SYMLOOK_IN_PLT;
2101
2102 lockstate = rlock_acquire(rtld_bind_lock);
2103 if (handle == NULL || handle == RTLD_NEXT ||
2104 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
2105
2106 if ((obj = obj_from_addr(retaddr)) == NULL) {
2107 _rtld_error("Cannot determine caller's shared object");
2108 rlock_release(rtld_bind_lock, lockstate);
2109 return NULL;
2110 }
2111 if (handle == NULL) { /* Just the caller's shared object. */
2112 def = symlook_obj(name, hash, obj, ve, flags);
2113 defobj = obj;
2114 } else if (handle == RTLD_NEXT || /* Objects after caller's */
2115 handle == RTLD_SELF) { /* ... caller included */
2116 if (handle == RTLD_NEXT)
2117 obj = obj->next;
2118 for (; obj != NULL; obj = obj->next) {
2119 if ((symp = symlook_obj(name, hash, obj, ve, flags)) != NULL) {
2120 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2121 def = symp;
2122 defobj = obj;
2123 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2124 break;
2125 }
2126 }
2127 }
2128 /*
2129 * Search the dynamic linker itself, and possibly resolve the
2130 * symbol from there. This is how the application links to
2131 * dynamic linker services such as dlopen.
2132 */
2133 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2134 symp = symlook_obj(name, hash, &obj_rtld, ve, flags);
2135 if (symp != NULL) {
2136 def = symp;
2137 defobj = &obj_rtld;
2138 }
2139 }
2140 } else {
2141 assert(handle == RTLD_DEFAULT);
2142 def = symlook_default(name, hash, obj, &defobj, ve, flags);
2143 }
2144 } else {
2145 if ((obj = dlcheck(handle)) == NULL) {
2146 rlock_release(rtld_bind_lock, lockstate);
2147 return NULL;
2148 }
2149
2150 donelist_init(&donelist);
2151 if (obj->mainprog) {
2152 /* Search main program and all libraries loaded by it. */
2153 def = symlook_list(name, hash, &list_main, &defobj, ve, flags,
2154 &donelist);
2155
2156 /*
2157 * We do not distinguish between 'main' object and global scope.
2158 * If symbol is not defined by objects loaded at startup, continue
2159 * search among dynamically loaded objects with RTLD_GLOBAL
2160 * scope.
2161 */
2162 if (def == NULL)
2163 def = symlook_list(name, hash, &list_global, &defobj, ve,
2164 flags, &donelist);
2165 } else {
2166 Needed_Entry fake;
2167
2168 /* Search the whole DAG rooted at the given object. */
2169 fake.next = NULL;
2170 fake.obj = (Obj_Entry *)obj;
2171 fake.name = 0;
2172 def = symlook_needed(name, hash, &fake, &defobj, ve, flags,
2173 &donelist);
2174 }
2175 }
2176
2177 if (def != NULL) {
2178 rlock_release(rtld_bind_lock, lockstate);
2179
2180 /*
2181 * The value required by the caller is derived from the value
2182 * of the symbol. For the ia64 architecture, we need to
2183 * construct a function descriptor which the caller can use to
2184 * call the function with the right 'gp' value. For other
2185 * architectures and for non-functions, the value is simply
2186 * the relocated value of the symbol.
2187 */
2188 if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
2189 return make_function_pointer(def, defobj);
2190 else
2191 return defobj->relocbase + def->st_value;
2192 }
2193
2194 _rtld_error("Undefined symbol \"%s\"", name);
2195 rlock_release(rtld_bind_lock, lockstate);
2196 return NULL;
2197}
2198
2199void *
2200dlsym(void *handle, const char *name)
2201{
2202 return do_dlsym(handle, name, __builtin_return_address(0), NULL,
2203 SYMLOOK_DLSYM);
2204}
2205
2206dlfunc_t
2207dlfunc(void *handle, const char *name)
2208{
2209 union {
2210 void *d;
2211 dlfunc_t f;
2212 } rv;
2213
2214 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
2215 SYMLOOK_DLSYM);
2216 return (rv.f);
2217}
2218
2219void *
2220dlvsym(void *handle, const char *name, const char *version)
2221{
2222 Ver_Entry ventry;
2223
2224 ventry.name = version;
2225 ventry.file = NULL;
2226 ventry.hash = elf_hash(version);
2227 ventry.flags= 0;
2228 return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
2229 SYMLOOK_DLSYM);
2230}
2231
2232int
2233_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
2234{
2235 const Obj_Entry *obj;
2236 int lockstate;
2237
2238 lockstate = rlock_acquire(rtld_bind_lock);
2239 obj = obj_from_addr(addr);
2240 if (obj == NULL) {
2241 _rtld_error("No shared object contains address");
2242 rlock_release(rtld_bind_lock, lockstate);
2243 return (0);
2244 }
2245 rtld_fill_dl_phdr_info(obj, phdr_info);
2246 rlock_release(rtld_bind_lock, lockstate);
2247 return (1);
2248}
2249
2250int
2251dladdr(const void *addr, Dl_info *info)
2252{
2253 const Obj_Entry *obj;
2254 const Elf_Sym *def;
2255 void *symbol_addr;
2256 unsigned long symoffset;
2257 int lockstate;
2258
2259 lockstate = rlock_acquire(rtld_bind_lock);
2260 obj = obj_from_addr(addr);
2261 if (obj == NULL) {
2262 _rtld_error("No shared object contains address");
2263 rlock_release(rtld_bind_lock, lockstate);
2264 return 0;
2265 }
2266 info->dli_fname = obj->path;
2267 info->dli_fbase = obj->mapbase;
2268 info->dli_saddr = (void *)0;
2269 info->dli_sname = NULL;
2270
2271 /*
2272 * Walk the symbol list looking for the symbol whose address is
2273 * closest to the address sent in.
2274 */
2275 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
2276 def = obj->symtab + symoffset;
2277
2278 /*
2279 * For skip the symbol if st_shndx is either SHN_UNDEF or
2280 * SHN_COMMON.
2281 */
2282 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
2283 continue;
2284
2285 /*
2286 * If the symbol is greater than the specified address, or if it
2287 * is further away from addr than the current nearest symbol,
2288 * then reject it.
2289 */
2290 symbol_addr = obj->relocbase + def->st_value;
2291 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
2292 continue;
2293
2294 /* Update our idea of the nearest symbol. */
2295 info->dli_sname = obj->strtab + def->st_name;
2296 info->dli_saddr = symbol_addr;
2297
2298 /* Exact match? */
2299 if (info->dli_saddr == addr)
2300 break;
2301 }
2302 rlock_release(rtld_bind_lock, lockstate);
2303 return 1;
2304}
2305
2306int
2307dlinfo(void *handle, int request, void *p)
2308{
2309 const Obj_Entry *obj;
2310 int error, lockstate;
2311
2312 lockstate = rlock_acquire(rtld_bind_lock);
2313
2314 if (handle == NULL || handle == RTLD_SELF) {
2315 void *retaddr;
2316
2317 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2318 if ((obj = obj_from_addr(retaddr)) == NULL)
2319 _rtld_error("Cannot determine caller's shared object");
2320 } else
2321 obj = dlcheck(handle);
2322
2323 if (obj == NULL) {
2324 rlock_release(rtld_bind_lock, lockstate);
2325 return (-1);
2326 }
2327
2328 error = 0;
2329 switch (request) {
2330 case RTLD_DI_LINKMAP:
2331 *((struct link_map const **)p) = &obj->linkmap;
2332 break;
2333 case RTLD_DI_ORIGIN:
2334 error = rtld_dirname(obj->path, p);
2335 break;
2336
2337 case RTLD_DI_SERINFOSIZE:
2338 case RTLD_DI_SERINFO:
2339 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2340 break;
2341
2342 default:
2343 _rtld_error("Invalid request %d passed to dlinfo()", request);
2344 error = -1;
2345 }
2346
2347 rlock_release(rtld_bind_lock, lockstate);
2348
2349 return (error);
2350}
2351
2352static void
2353rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
2354{
2355
2356 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
2357 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ?
2358 STAILQ_FIRST(&obj->names)->name : obj->path;
2359 phdr_info->dlpi_phdr = obj->phdr;
2360 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
2361 phdr_info->dlpi_tls_modid = obj->tlsindex;
2362 phdr_info->dlpi_tls_data = obj->tlsinit;
2363 phdr_info->dlpi_adds = obj_loads;
2364 phdr_info->dlpi_subs = obj_loads - obj_count;
2365}
2366
2367int
2368dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
2369{
2370 struct dl_phdr_info phdr_info;
2371 const Obj_Entry *obj;
2372 int error, bind_lockstate, phdr_lockstate;
2373
2374 phdr_lockstate = wlock_acquire(rtld_phdr_lock);
2375 bind_lockstate = rlock_acquire(rtld_bind_lock);
2376
2377 error = 0;
2378
2379 for (obj = obj_list; obj != NULL; obj = obj->next) {
2380 rtld_fill_dl_phdr_info(obj, &phdr_info);
2381 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
2382 break;
2383
2384 }
2385 rlock_release(rtld_bind_lock, bind_lockstate);
2386 wlock_release(rtld_phdr_lock, phdr_lockstate);
2387
2388 return (error);
2389}
2390
2391struct fill_search_info_args {
2392 int request;
2393 unsigned int flags;
2394 Dl_serinfo *serinfo;
2395 Dl_serpath *serpath;
2396 char *strspace;
2397};
2398
2399static void *
2400fill_search_info(const char *dir, size_t dirlen, void *param)
2401{
2402 struct fill_search_info_args *arg;
2403
2404 arg = param;
2405
2406 if (arg->request == RTLD_DI_SERINFOSIZE) {
2407 arg->serinfo->dls_cnt ++;
2408 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1;
2409 } else {
2410 struct dl_serpath *s_entry;
2411
2412 s_entry = arg->serpath;
2413 s_entry->dls_name = arg->strspace;
2414 s_entry->dls_flags = arg->flags;
2415
2416 strncpy(arg->strspace, dir, dirlen);
2417 arg->strspace[dirlen] = '\0';
2418
2419 arg->strspace += dirlen + 1;
2420 arg->serpath++;
2421 }
2422
2423 return (NULL);
2424}
2425
2426static int
2427do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2428{
2429 struct dl_serinfo _info;
2430 struct fill_search_info_args args;
2431
2432 args.request = RTLD_DI_SERINFOSIZE;
2433 args.serinfo = &_info;
2434
2435 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2436 _info.dls_cnt = 0;
2437
2438 path_enumerate(ld_library_path, fill_search_info, &args);
2439 path_enumerate(obj->rpath, fill_search_info, &args);
2440 path_enumerate(gethints(), fill_search_info, &args);
2441 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2442
2443
2444 if (request == RTLD_DI_SERINFOSIZE) {
2445 info->dls_size = _info.dls_size;
2446 info->dls_cnt = _info.dls_cnt;
2447 return (0);
2448 }
2449
2450 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2451 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2452 return (-1);
2453 }
2454
2455 args.request = RTLD_DI_SERINFO;
2456 args.serinfo = info;
2457 args.serpath = &info->dls_serpath[0];
2458 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2459
2460 args.flags = LA_SER_LIBPATH;
2461 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2462 return (-1);
2463
2464 args.flags = LA_SER_RUNPATH;
2465 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2466 return (-1);
2467
2468 args.flags = LA_SER_CONFIG;
2469 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2470 return (-1);
2471
2472 args.flags = LA_SER_DEFAULT;
2473 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2474 return (-1);
2475 return (0);
2476}
2477
2478static int
2479rtld_dirname(const char *path, char *bname)
2480{
2481 const char *endp;
2482
2483 /* Empty or NULL string gets treated as "." */
2484 if (path == NULL || *path == '\0') {
2485 bname[0] = '.';
2486 bname[1] = '\0';
2487 return (0);
2488 }
2489
2490 /* Strip trailing slashes */
2491 endp = path + strlen(path) - 1;
2492 while (endp > path && *endp == '/')
2493 endp--;
2494
2495 /* Find the start of the dir */
2496 while (endp > path && *endp != '/')
2497 endp--;
2498
2499 /* Either the dir is "/" or there are no slashes */
2500 if (endp == path) {
2501 bname[0] = *endp == '/' ? '/' : '.';
2502 bname[1] = '\0';
2503 return (0);
2504 } else {
2505 do {
2506 endp--;
2507 } while (endp > path && *endp == '/');
2508 }
2509
2510 if (endp - path + 2 > PATH_MAX)
2511 {
2512 _rtld_error("Filename is too long: %s", path);
2513 return(-1);
2514 }
2515
2516 strncpy(bname, path, endp - path + 1);
2517 bname[endp - path + 1] = '\0';
2518 return (0);
2519}
2520
2521static int
2522rtld_dirname_abs(const char *path, char *base)
2523{
2524 char base_rel[PATH_MAX];
2525
2526 if (rtld_dirname(path, base) == -1)
2527 return (-1);
2528 if (base[0] == '/')
2529 return (0);
2530 if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
2531 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
2532 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
2533 return (-1);
2534 strcpy(base, base_rel);
2535 return (0);
2536}
2537
2538static void
2539linkmap_add(Obj_Entry *obj)
2540{
2541 struct link_map *l = &obj->linkmap;
2542 struct link_map *prev;
2543
2544 obj->linkmap.l_name = obj->path;
2545 obj->linkmap.l_addr = obj->mapbase;
2546 obj->linkmap.l_ld = obj->dynamic;
2547#ifdef __mips__
2548 /* GDB needs load offset on MIPS to use the symbols */
2549 obj->linkmap.l_offs = obj->relocbase;
2550#endif
2551
2552 if (r_debug.r_map == NULL) {
2553 r_debug.r_map = l;
2554 return;
2555 }
2556
2557 /*
2558 * Scan to the end of the list, but not past the entry for the
2559 * dynamic linker, which we want to keep at the very end.
2560 */
2561 for (prev = r_debug.r_map;
2562 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2563 prev = prev->l_next)
2564 ;
2565
2566 /* Link in the new entry. */
2567 l->l_prev = prev;
2568 l->l_next = prev->l_next;
2569 if (l->l_next != NULL)
2570 l->l_next->l_prev = l;
2571 prev->l_next = l;
2572}
2573
2574static void
2575linkmap_delete(Obj_Entry *obj)
2576{
2577 struct link_map *l = &obj->linkmap;
2578
2579 if (l->l_prev == NULL) {
2580 if ((r_debug.r_map = l->l_next) != NULL)
2581 l->l_next->l_prev = NULL;
2582 return;
2583 }
2584
2585 if ((l->l_prev->l_next = l->l_next) != NULL)
2586 l->l_next->l_prev = l->l_prev;
2587}
2588
2589/*
2590 * Function for the debugger to set a breakpoint on to gain control.
2591 *
2592 * The two parameters allow the debugger to easily find and determine
2593 * what the runtime loader is doing and to whom it is doing it.
2594 *
2595 * When the loadhook trap is hit (r_debug_state, set at program
2596 * initialization), the arguments can be found on the stack:
2597 *
2598 * +8 struct link_map *m
2599 * +4 struct r_debug *rd
2600 * +0 RetAddr
2601 */
2602void
2603r_debug_state(struct r_debug* rd, struct link_map *m)
2604{
2605}
2606
2607/*
2608 * Get address of the pointer variable in the main program.
2609 */
2610static const void **
2611get_program_var_addr(const char *name)
2612{
2613 const Obj_Entry *obj;
2614 unsigned long hash;
2615
2616 hash = elf_hash(name);
2617 for (obj = obj_main; obj != NULL; obj = obj->next) {
2618 const Elf_Sym *def;
2619
2620 if ((def = symlook_obj(name, hash, obj, NULL, 0)) != NULL) {
2621 const void **addr;
2622
2623 addr = (const void **)(obj->relocbase + def->st_value);
2624 return addr;
2625 }
2626 }
2627 return NULL;
2628}
2629
2630/*
2631 * Set a pointer variable in the main program to the given value. This
2632 * is used to set key variables such as "environ" before any of the
2633 * init functions are called.
2634 */
2635static void
2636set_program_var(const char *name, const void *value)
2637{
2638 const void **addr;
2639
2640 if ((addr = get_program_var_addr(name)) != NULL) {
2641 dbg("\"%s\": *%p <-- %p", name, addr, value);
2642 *addr = value;
2643 }
2644}
2645
2646/*
2647 * Given a symbol name in a referencing object, find the corresponding
2648 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2649 * no definition was found. Returns a pointer to the Obj_Entry of the
2650 * defining object via the reference parameter DEFOBJ_OUT.
2651 */
2652static const Elf_Sym *
2653symlook_default(const char *name, unsigned long hash, const Obj_Entry *refobj,
2654 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags)
2655{
2656 DoneList donelist;
2657 const Elf_Sym *def;
2658 const Elf_Sym *symp;
2659 const Obj_Entry *obj;
2660 const Obj_Entry *defobj;
2661 const Objlist_Entry *elm;
2662 def = NULL;
2663 defobj = NULL;
2664 donelist_init(&donelist);
2665
2666 /* Look first in the referencing object if linked symbolically. */
2667 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
2668 symp = symlook_obj(name, hash, refobj, ventry, flags);
2669 if (symp != NULL) {
2670 def = symp;
2671 defobj = refobj;
2672 }
2673 }
2674
2675 /* Search all objects loaded at program start up. */
2676 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2677 symp = symlook_list(name, hash, &list_main, &obj, ventry, flags,
2678 &donelist);
2679 if (symp != NULL &&
2680 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2681 def = symp;
2682 defobj = obj;
2683 }
2684 }
2685
2686 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2687 STAILQ_FOREACH(elm, &list_global, link) {
2688 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2689 break;
2690 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry,
2691 flags, &donelist);
2692 if (symp != NULL &&
2693 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2694 def = symp;
2695 defobj = obj;
2696 }
2697 }
2698
2699 /* Search all dlopened DAGs containing the referencing object. */
2700 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2701 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2702 break;
2703 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry,
2704 flags, &donelist);
2705 if (symp != NULL &&
2706 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2707 def = symp;
2708 defobj = obj;
2709 }
2710 }
2711
2712 /*
2713 * Search the dynamic linker itself, and possibly resolve the
2714 * symbol from there. This is how the application links to
2715 * dynamic linker services such as dlopen.
2716 */
2717 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2718 symp = symlook_obj(name, hash, &obj_rtld, ventry, flags);
2719 if (symp != NULL) {
2720 def = symp;
2721 defobj = &obj_rtld;
2722 }
2723 }
2724
2725 if (def != NULL)
2726 *defobj_out = defobj;
2727 return def;
2728}
2729
2730static const Elf_Sym *
2731symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
2732 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags,
2733 DoneList *dlp)
2734{
2735 const Elf_Sym *symp;
2736 const Elf_Sym *def;
2737 const Obj_Entry *defobj;
2738 const Objlist_Entry *elm;
2739
2740 def = NULL;
2741 defobj = NULL;
2742 STAILQ_FOREACH(elm, objlist, link) {
2743 if (donelist_check(dlp, elm->obj))
2744 continue;
2745 if ((symp = symlook_obj(name, hash, elm->obj, ventry, flags)) != NULL) {
2746 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2747 def = symp;
2748 defobj = elm->obj;
2749 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2750 break;
2751 }
2752 }
2753 }
2754 if (def != NULL)
2755 *defobj_out = defobj;
2756 return def;
2757}
2758
2759/*
2760 * Search the symbol table of a shared object and all objects needed
2761 * by it for a symbol of the given name. Search order is
2762 * breadth-first. Returns a pointer to the symbol, or NULL if no
2763 * definition was found.
2764 */
2765static const Elf_Sym *
2766symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
2767 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags,
2768 DoneList *dlp)
2769{
2770 const Elf_Sym *def, *def_w;
2771 const Needed_Entry *n;
2772 const Obj_Entry *obj, *defobj, *defobj1;
2773
2774 def = def_w = NULL;
2775 defobj = NULL;
2776 for (n = needed; n != NULL; n = n->next) {
2777 if ((obj = n->obj) == NULL ||
2778 donelist_check(dlp, obj) ||
2779 (def = symlook_obj(name, hash, obj, ventry, flags)) == NULL)
2780 continue;
2781 defobj = obj;
2782 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2783 *defobj_out = defobj;
2784 return (def);
2785 }
2786 }
2787 /*
2788 * There we come when either symbol definition is not found in
2789 * directly needed objects, or found symbol is weak.
2790 */
2791 for (n = needed; n != NULL; n = n->next) {
2792 if ((obj = n->obj) == NULL)
2793 continue;
2794 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
2795 ventry, flags, dlp);
2796 if (def_w == NULL)
2797 continue;
2798 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
2799 def = def_w;
2800 defobj = defobj1;
2801 }
2802 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
2803 break;
2804 }
2805 if (def != NULL)
2806 *defobj_out = defobj;
2807 return (def);
2808}
2809
2810/*
2811 * Search the symbol table of a single shared object for a symbol of
2812 * the given name and version, if requested. Returns a pointer to the
2813 * symbol, or NULL if no definition was found.
2814 *
2815 * The symbol's hash value is passed in for efficiency reasons; that
2816 * eliminates many recomputations of the hash value.
2817 */
2818const Elf_Sym *
2819symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
2820 const Ver_Entry *ventry, int flags)
2821{
2822 unsigned long symnum;
2823 const Elf_Sym *vsymp;
2824 Elf_Versym verndx;
2825 int vcount;
2826
2827 if (obj->buckets == NULL)
2828 return NULL;
2829
2830 vsymp = NULL;
2831 vcount = 0;
2832 symnum = obj->buckets[hash % obj->nbuckets];
2833
2834 for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
2835 const Elf_Sym *symp;
2836 const char *strp;
2837
2838 if (symnum >= obj->nchains)
2839 return NULL; /* Bad object */
2840
2841 symp = obj->symtab + symnum;
2842 strp = obj->strtab + symp->st_name;
2843
2844 switch (ELF_ST_TYPE(symp->st_info)) {
2845 case STT_FUNC:
2846 case STT_NOTYPE:
2847 case STT_OBJECT:
2848 if (symp->st_value == 0)
2849 continue;
2850 /* fallthrough */
2851 case STT_TLS:
2852 if (symp->st_shndx != SHN_UNDEF)
2853 break;
2854#ifndef __mips__
2855 else if (((flags & SYMLOOK_IN_PLT) == 0) &&
2856 (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
2857 break;
2858 /* fallthrough */
2859#endif
2860 default:
2861 continue;
2862 }
2863 if (name[0] != strp[0] || strcmp(name, strp) != 0)
2864 continue;
2865
2866 if (ventry == NULL) {
2867 if (obj->versyms != NULL) {
2868 verndx = VER_NDX(obj->versyms[symnum]);
2869 if (verndx > obj->vernum) {
2870 _rtld_error("%s: symbol %s references wrong version %d",
2871 obj->path, obj->strtab + symnum, verndx);
2872 continue;
2873 }
2874 /*
2875 * If we are not called from dlsym (i.e. this is a normal
2876 * relocation from unversioned binary, accept the symbol
2877 * immediately if it happens to have first version after
2878 * this shared object became versioned. Otherwise, if
2879 * symbol is versioned and not hidden, remember it. If it
2880 * is the only symbol with this name exported by the
2881 * shared object, it will be returned as a match at the
2882 * end of the function. If symbol is global (verndx < 2)
2883 * accept it unconditionally.
2884 */
2885 if ((flags & SYMLOOK_DLSYM) == 0 && verndx == VER_NDX_GIVEN)
2886 return symp;
2887 else if (verndx >= VER_NDX_GIVEN) {
2888 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) {
2889 if (vsymp == NULL)
2890 vsymp = symp;
2891 vcount ++;
2892 }
2893 continue;
2894 }
2895 }
2896 return symp;
2897 } else {
2898 if (obj->versyms == NULL) {
2899 if (object_match_name(obj, ventry->name)) {
2900 _rtld_error("%s: object %s should provide version %s for "
2901 "symbol %s", obj_rtld.path, obj->path, ventry->name,
2902 obj->strtab + symnum);
2903 continue;
2904 }
2905 } else {
2906 verndx = VER_NDX(obj->versyms[symnum]);
2907 if (verndx > obj->vernum) {
2908 _rtld_error("%s: symbol %s references wrong version %d",
2909 obj->path, obj->strtab + symnum, verndx);
2910 continue;
2911 }
2912 if (obj->vertab[verndx].hash != ventry->hash ||
2913 strcmp(obj->vertab[verndx].name, ventry->name)) {
2914 /*
2915 * Version does not match. Look if this is a global symbol
2916 * and if it is not hidden. If global symbol (verndx < 2)
2917 * is available, use it. Do not return symbol if we are
2918 * called by dlvsym, because dlvsym looks for a specific
2919 * version and default one is not what dlvsym wants.
2920 */
2921 if ((flags & SYMLOOK_DLSYM) ||
2922 (obj->versyms[symnum] & VER_NDX_HIDDEN) ||
2923 (verndx >= VER_NDX_GIVEN))
2924 continue;
2925 }
2926 }
2927 return symp;
2928 }
2929 }
2930 return (vcount == 1) ? vsymp : NULL;
2931}
2932
2933static void
2934trace_loaded_objects(Obj_Entry *obj)
2935{
2936 char *fmt1, *fmt2, *fmt, *main_local, *list_containers;
2937 int c;
2938
2939 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
2940 main_local = "";
2941
2942 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL)
2943 fmt1 = "\t%o => %p (%x)\n";
2944
2945 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL)
2946 fmt2 = "\t%o (%x)\n";
2947
2948 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL");
2949
2950 for (; obj; obj = obj->next) {
2951 Needed_Entry *needed;
2952 char *name, *path;
2953 bool is_lib;
2954
2955 if (list_containers && obj->needed != NULL)
2956 printf("%s:\n", obj->path);
2957 for (needed = obj->needed; needed; needed = needed->next) {
2958 if (needed->obj != NULL) {
2959 if (needed->obj->traced && !list_containers)
2960 continue;
2961 needed->obj->traced = true;
2962 path = needed->obj->path;
2963 } else
2964 path = "not found";
2965
2966 name = (char *)obj->strtab + needed->name;
2967 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
2968
2969 fmt = is_lib ? fmt1 : fmt2;
2970 while ((c = *fmt++) != '\0') {
2971 switch (c) {
2972 default:
2973 putchar(c);
2974 continue;
2975 case '\\':
2976 switch (c = *fmt) {
2977 case '\0':
2978 continue;
2979 case 'n':
2980 putchar('\n');
2981 break;
2982 case 't':
2983 putchar('\t');
2984 break;
2985 }
2986 break;
2987 case '%':
2988 switch (c = *fmt) {
2989 case '\0':
2990 continue;
2991 case '%':
2992 default:
2993 putchar(c);
2994 break;
2995 case 'A':
2996 printf("%s", main_local);
2997 break;
2998 case 'a':
2999 printf("%s", obj_main->path);
3000 break;
3001 case 'o':
3002 printf("%s", name);
3003 break;
3004#if 0
3005 case 'm':
3006 printf("%d", sodp->sod_major);
3007 break;
3008 case 'n':
3009 printf("%d", sodp->sod_minor);
3010 break;
3011#endif
3012 case 'p':
3013 printf("%s", path);
3014 break;
3015 case 'x':
3016 printf("%p", needed->obj ? needed->obj->mapbase : 0);
3017 break;
3018 }
3019 break;
3020 }
3021 ++fmt;
3022 }
3023 }
3024 }
3025}
3026
3027/*
3028 * Unload a dlopened object and its dependencies from memory and from
3029 * our data structures. It is assumed that the DAG rooted in the
3030 * object has already been unreferenced, and that the object has a
3031 * reference count of 0.
3032 */
3033static void
3034unload_object(Obj_Entry *root)
3035{
3036 Obj_Entry *obj;
3037 Obj_Entry **linkp;
3038
3039 assert(root->refcount == 0);
3040
3041 /*
3042 * Pass over the DAG removing unreferenced objects from
3043 * appropriate lists.
3044 */
3045 unlink_object(root);
3046
3047 /* Unmap all objects that are no longer referenced. */
3048 linkp = &obj_list->next;
3049 while ((obj = *linkp) != NULL) {
3050 if (obj->refcount == 0) {
3051 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
3052 obj->path);
3053 dbg("unloading \"%s\"", obj->path);
3054 munmap(obj->mapbase, obj->mapsize);
3055 linkmap_delete(obj);
3056 *linkp = obj->next;
3057 obj_count--;
3058 obj_free(obj);
3059 } else
3060 linkp = &obj->next;
3061 }
3062 obj_tail = linkp;
3063}
3064
3065static void
3066unlink_object(Obj_Entry *root)
3067{
3068 Objlist_Entry *elm;
3069
3070 if (root->refcount == 0) {
3071 /* Remove the object from the RTLD_GLOBAL list. */
3072 objlist_remove(&list_global, root);
3073
3074 /* Remove the object from all objects' DAG lists. */
3075 STAILQ_FOREACH(elm, &root->dagmembers, link) {
3076 objlist_remove(&elm->obj->dldags, root);
3077 if (elm->obj != root)
3078 unlink_object(elm->obj);
3079 }
3080 }
3081}
3082
3083static void
3084ref_dag(Obj_Entry *root)
3085{
3086 Objlist_Entry *elm;
3087
3088 STAILQ_FOREACH(elm, &root->dagmembers, link)
3089 elm->obj->refcount++;
3090}
3091
3092static void
3093unref_dag(Obj_Entry *root)
3094{
3095 Objlist_Entry *elm;
3096
3097 STAILQ_FOREACH(elm, &root->dagmembers, link)
3098 elm->obj->refcount--;
3099}
3100
3101/*
3102 * Common code for MD __tls_get_addr().
3103 */
3104void *
3105tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset)
3106{
3107 Elf_Addr* dtv = *dtvp;
3108 int lockstate;
3109
3110 /* Check dtv generation in case new modules have arrived */
3111 if (dtv[0] != tls_dtv_generation) {
3112 Elf_Addr* newdtv;
3113 int to_copy;
3114
3115 lockstate = wlock_acquire(rtld_bind_lock);
3116 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
3117 to_copy = dtv[1];
3118 if (to_copy > tls_max_index)
3119 to_copy = tls_max_index;
3120 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
3121 newdtv[0] = tls_dtv_generation;
3122 newdtv[1] = tls_max_index;
3123 free(dtv);
3124 wlock_release(rtld_bind_lock, lockstate);
3125 *dtvp = newdtv;
3126 }
3127
3128 /* Dynamically allocate module TLS if necessary */
3129 if (!dtv[index + 1]) {
3130 /* Signal safe, wlock will block out signals. */
3131 lockstate = wlock_acquire(rtld_bind_lock);
3132 if (!dtv[index + 1])
3133 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
3134 wlock_release(rtld_bind_lock, lockstate);
3135 }
3136 return (void*) (dtv[index + 1] + offset);
3137}
3138
3139/* XXX not sure what variants to use for arm. */
3140
3141#if defined(__ia64__) || defined(__powerpc__)
3142
3143/*
3144 * Allocate Static TLS using the Variant I method.
3145 */
3146void *
3147allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
3148{
3149 Obj_Entry *obj;
3150 char *tcb;
3151 Elf_Addr **tls;
3152 Elf_Addr *dtv;
3153 Elf_Addr addr;
3154 int i;
3155
3156 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
3157 return (oldtcb);
3158
3159 assert(tcbsize >= TLS_TCB_SIZE);
3160 tcb = calloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
3161 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
3162
3163 if (oldtcb != NULL) {
3164 memcpy(tls, oldtcb, tls_static_space);
3165 free(oldtcb);
3166
3167 /* Adjust the DTV. */
3168 dtv = tls[0];
3169 for (i = 0; i < dtv[1]; i++) {
3170 if (dtv[i+2] >= (Elf_Addr)oldtcb &&
3171 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
3172 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
3173 }
3174 }
3175 } else {
3176 dtv = calloc(tls_max_index + 2, sizeof(Elf_Addr));
3177 tls[0] = dtv;
3178 dtv[0] = tls_dtv_generation;
3179 dtv[1] = tls_max_index;
3180
3181 for (obj = objs; obj; obj = obj->next) {
3182 if (obj->tlsoffset > 0) {
3183 addr = (Elf_Addr)tls + obj->tlsoffset;
3184 if (obj->tlsinitsize > 0)
3185 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
3186 if (obj->tlssize > obj->tlsinitsize)
3187 memset((void*) (addr + obj->tlsinitsize), 0,
3188 obj->tlssize - obj->tlsinitsize);
3189 dtv[obj->tlsindex + 1] = addr;
3190 }
3191 }
3192 }
3193
3194 return (tcb);
3195}
3196
3197void
3198free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
3199{
3200 Elf_Addr *dtv;
3201 Elf_Addr tlsstart, tlsend;
3202 int dtvsize, i;
3203
3204 assert(tcbsize >= TLS_TCB_SIZE);
3205
3206 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
3207 tlsend = tlsstart + tls_static_space;
3208
3209 dtv = *(Elf_Addr **)tlsstart;
3210 dtvsize = dtv[1];
3211 for (i = 0; i < dtvsize; i++) {
3212 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
3213 free((void*)dtv[i+2]);
3214 }
3215 }
3216 free(dtv);
3217 free(tcb);
3218}
3219
3220#endif
3221
3222#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \
3223 defined(__arm__) || defined(__mips__)
3224
3225/*
3226 * Allocate Static TLS using the Variant II method.
3227 */
3228void *
3229allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
3230{
3231 Obj_Entry *obj;
3232 size_t size;
3233 char *tls;
3234 Elf_Addr *dtv, *olddtv;
3235 Elf_Addr segbase, oldsegbase, addr;
3236 int i;
3237
3238 size = round(tls_static_space, tcbalign);
3239
3240 assert(tcbsize >= 2*sizeof(Elf_Addr));
3241 tls = calloc(1, size + tcbsize);
3242 dtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
3243
3244 segbase = (Elf_Addr)(tls + size);
3245 ((Elf_Addr*)segbase)[0] = segbase;
3246 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
3247
3248 dtv[0] = tls_dtv_generation;
3249 dtv[1] = tls_max_index;
3250
3251 if (oldtls) {
3252 /*
3253 * Copy the static TLS block over whole.
3254 */
3255 oldsegbase = (Elf_Addr) oldtls;
3256 memcpy((void *)(segbase - tls_static_space),
3257 (const void *)(oldsegbase - tls_static_space),
3258 tls_static_space);
3259
3260 /*
3261 * If any dynamic TLS blocks have been created tls_get_addr(),
3262 * move them over.
3263 */
3264 olddtv = ((Elf_Addr**)oldsegbase)[1];
3265 for (i = 0; i < olddtv[1]; i++) {
3266 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
3267 dtv[i+2] = olddtv[i+2];
3268 olddtv[i+2] = 0;
3269 }
3270 }
3271
3272 /*
3273 * We assume that this block was the one we created with
3274 * allocate_initial_tls().
3275 */
3276 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
3277 } else {
3278 for (obj = objs; obj; obj = obj->next) {
3279 if (obj->tlsoffset) {
3280 addr = segbase - obj->tlsoffset;
3281 memset((void*) (addr + obj->tlsinitsize),
3282 0, obj->tlssize - obj->tlsinitsize);
3283 if (obj->tlsinit)
3284 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
3285 dtv[obj->tlsindex + 1] = addr;
3286 }
3287 }
3288 }
3289
3290 return (void*) segbase;
3291}
3292
3293void
3294free_tls(void *tls, size_t tcbsize, size_t tcbalign)
3295{
3296 size_t size;
3297 Elf_Addr* dtv;
3298 int dtvsize, i;
3299 Elf_Addr tlsstart, tlsend;
3300
3301 /*
3302 * Figure out the size of the initial TLS block so that we can
3303 * find stuff which ___tls_get_addr() allocated dynamically.
3304 */
3305 size = round(tls_static_space, tcbalign);
3306
3307 dtv = ((Elf_Addr**)tls)[1];
3308 dtvsize = dtv[1];
3309 tlsend = (Elf_Addr) tls;
3310 tlsstart = tlsend - size;
3311 for (i = 0; i < dtvsize; i++) {
3312 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) {
3313 free((void*) dtv[i+2]);
3314 }
3315 }
3316
3317 free((void*) tlsstart);
3318 free((void*) dtv);
3319}
3320
3321#endif
3322
3323/*
3324 * Allocate TLS block for module with given index.
3325 */
3326void *
3327allocate_module_tls(int index)
3328{
3329 Obj_Entry* obj;
3330 char* p;
3331
3332 for (obj = obj_list; obj; obj = obj->next) {
3333 if (obj->tlsindex == index)
3334 break;
3335 }
3336 if (!obj) {
3337 _rtld_error("Can't find module with TLS index %d", index);
3338 die();
3339 }
3340
3341 p = malloc(obj->tlssize);
3342 if (p == NULL) {
3343 _rtld_error("Cannot allocate TLS block for index %d", index);
3344 die();
3345 }
3346 memcpy(p, obj->tlsinit, obj->tlsinitsize);
3347 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
3348
3349 return p;
3350}
3351
3352bool
3353allocate_tls_offset(Obj_Entry *obj)
3354{
3355 size_t off;
3356
3357 if (obj->tls_done)
3358 return true;
3359
3360 if (obj->tlssize == 0) {
3361 obj->tls_done = true;
3362 return true;
3363 }
3364
3365 if (obj->tlsindex == 1)
3366 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
3367 else
3368 off = calculate_tls_offset(tls_last_offset, tls_last_size,
3369 obj->tlssize, obj->tlsalign);
3370
3371 /*
3372 * If we have already fixed the size of the static TLS block, we
3373 * must stay within that size. When allocating the static TLS, we
3374 * leave a small amount of space spare to be used for dynamically
3375 * loading modules which use static TLS.
3376 */
3377 if (tls_static_space) {
3378 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
3379 return false;
3380 }
3381
3382 tls_last_offset = obj->tlsoffset = off;
3383 tls_last_size = obj->tlssize;
3384 obj->tls_done = true;
3385
3386 return true;
3387}
3388
3389void
3390free_tls_offset(Obj_Entry *obj)
3391{
3392
3393 /*
3394 * If we were the last thing to allocate out of the static TLS
3395 * block, we give our space back to the 'allocator'. This is a
3396 * simplistic workaround to allow libGL.so.1 to be loaded and
3397 * unloaded multiple times.
3398 */
3399 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
3400 == calculate_tls_end(tls_last_offset, tls_last_size)) {
3401 tls_last_offset -= obj->tlssize;
3402 tls_last_size = 0;
3403 }
3404}
3405
3406void *
3407_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
3408{
3409 void *ret;
3410 int lockstate;
3411
3412 lockstate = wlock_acquire(rtld_bind_lock);
3413 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign);
3414 wlock_release(rtld_bind_lock, lockstate);
3415 return (ret);
3416}
3417
3418void
3419_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
3420{
3421 int lockstate;
3422
3423 lockstate = wlock_acquire(rtld_bind_lock);
3424 free_tls(tcb, tcbsize, tcbalign);
3425 wlock_release(rtld_bind_lock, lockstate);
3426}
3427
3428static void
3429object_add_name(Obj_Entry *obj, const char *name)
3430{
3431 Name_Entry *entry;
3432 size_t len;
3433
3434 len = strlen(name);
3435 entry = malloc(sizeof(Name_Entry) + len);
3436
3437 if (entry != NULL) {
3438 strcpy(entry->name, name);
3439 STAILQ_INSERT_TAIL(&obj->names, entry, link);
3440 }
3441}
3442
3443static int
3444object_match_name(const Obj_Entry *obj, const char *name)
3445{
3446 Name_Entry *entry;
3447
3448 STAILQ_FOREACH(entry, &obj->names, link) {
3449 if (strcmp(name, entry->name) == 0)
3450 return (1);
3451 }
3452 return (0);
3453}
3454
3455static Obj_Entry *
3456locate_dependency(const Obj_Entry *obj, const char *name)
3457{
3458 const Objlist_Entry *entry;
3459 const Needed_Entry *needed;
3460
3461 STAILQ_FOREACH(entry, &list_main, link) {
3462 if (object_match_name(entry->obj, name))
3463 return entry->obj;
3464 }
3465
3466 for (needed = obj->needed; needed != NULL; needed = needed->next) {
3467 if (needed->obj == NULL)
3468 continue;
3469 if (object_match_name(needed->obj, name))
3470 return needed->obj;
3471 }
3472 _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
3473 obj->path, name);
3474 die();
3475}
3476
3477static int
3478check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
3479 const Elf_Vernaux *vna)
3480{
3481 const Elf_Verdef *vd;
3482 const char *vername;
3483
3484 vername = refobj->strtab + vna->vna_name;
3485 vd = depobj->verdef;
3486 if (vd == NULL) {
3487 _rtld_error("%s: version %s required by %s not defined",
3488 depobj->path, vername, refobj->path);
3489 return (-1);
3490 }
3491 for (;;) {
3492 if (vd->vd_version != VER_DEF_CURRENT) {
3493 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
3494 depobj->path, vd->vd_version);
3495 return (-1);
3496 }
3497 if (vna->vna_hash == vd->vd_hash) {
3498 const Elf_Verdaux *aux = (const Elf_Verdaux *)
3499 ((char *)vd + vd->vd_aux);
3500 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
3501 return (0);
3502 }
3503 if (vd->vd_next == 0)
3504 break;
3505 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3506 }
3507 if (vna->vna_flags & VER_FLG_WEAK)
3508 return (0);
3509 _rtld_error("%s: version %s required by %s not found",
3510 depobj->path, vername, refobj->path);
3511 return (-1);
3512}
3513
3514static int
3515rtld_verify_object_versions(Obj_Entry *obj)
3516{
3517 const Elf_Verneed *vn;
3518 const Elf_Verdef *vd;
3519 const Elf_Verdaux *vda;
3520 const Elf_Vernaux *vna;
3521 const Obj_Entry *depobj;
3522 int maxvernum, vernum;
3523
3524 maxvernum = 0;
3525 /*
3526 * Walk over defined and required version records and figure out
3527 * max index used by any of them. Do very basic sanity checking
3528 * while there.
3529 */
3530 vn = obj->verneed;
3531 while (vn != NULL) {
3532 if (vn->vn_version != VER_NEED_CURRENT) {
3533 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
3534 obj->path, vn->vn_version);
3535 return (-1);
3536 }
3537 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
3538 for (;;) {
3539 vernum = VER_NEED_IDX(vna->vna_other);
3540 if (vernum > maxvernum)
3541 maxvernum = vernum;
3542 if (vna->vna_next == 0)
3543 break;
3544 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
3545 }
3546 if (vn->vn_next == 0)
3547 break;
3548 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
3549 }
3550
3551 vd = obj->verdef;
3552 while (vd != NULL) {
3553 if (vd->vd_version != VER_DEF_CURRENT) {
3554 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
3555 obj->path, vd->vd_version);
3556 return (-1);
3557 }
3558 vernum = VER_DEF_IDX(vd->vd_ndx);
3559 if (vernum > maxvernum)
3560 maxvernum = vernum;
3561 if (vd->vd_next == 0)
3562 break;
3563 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3564 }
3565
3566 if (maxvernum == 0)
3567 return (0);
3568
3569 /*
3570 * Store version information in array indexable by version index.
3571 * Verify that object version requirements are satisfied along the
3572 * way.
3573 */
3574 obj->vernum = maxvernum + 1;
3575 obj->vertab = calloc(obj->vernum, sizeof(Ver_Entry));
3576
3577 vd = obj->verdef;
3578 while (vd != NULL) {
3579 if ((vd->vd_flags & VER_FLG_BASE) == 0) {
3580 vernum = VER_DEF_IDX(vd->vd_ndx);
3581 assert(vernum <= maxvernum);
3582 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
3583 obj->vertab[vernum].hash = vd->vd_hash;
3584 obj->vertab[vernum].name = obj->strtab + vda->vda_name;
3585 obj->vertab[vernum].file = NULL;
3586 obj->vertab[vernum].flags = 0;
3587 }
3588 if (vd->vd_next == 0)
3589 break;
3590 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3591 }
3592
3593 vn = obj->verneed;
3594 while (vn != NULL) {
3595 depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
3596 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
3597 for (;;) {
3598 if (check_object_provided_version(obj, depobj, vna))
3599 return (-1);
3600 vernum = VER_NEED_IDX(vna->vna_other);
3601 assert(vernum <= maxvernum);
3602 obj->vertab[vernum].hash = vna->vna_hash;
3603 obj->vertab[vernum].name = obj->strtab + vna->vna_name;
3604 obj->vertab[vernum].file = obj->strtab + vn->vn_file;
3605 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
3606 VER_INFO_HIDDEN : 0;
3607 if (vna->vna_next == 0)
3608 break;
3609 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
3610 }
3611 if (vn->vn_next == 0)
3612 break;
3613 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
3614 }
3615 return 0;
3616}
3617
3618static int
3619rtld_verify_versions(const Objlist *objlist)
3620{
3621 Objlist_Entry *entry;
3622 int rc;
3623
3624 rc = 0;
3625 STAILQ_FOREACH(entry, objlist, link) {
3626 /*
3627 * Skip dummy objects or objects that have their version requirements
3628 * already checked.
3629 */
3630 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
3631 continue;
3632 if (rtld_verify_object_versions(entry->obj) == -1) {
3633 rc = -1;
3634 if (ld_tracing == NULL)
3635 break;
3636 }
3637 }
3638 if (rc == 0 || ld_tracing != NULL)
3639 rc = rtld_verify_object_versions(&obj_rtld);
3640 return rc;
3641}
3642
3643const Ver_Entry *
3644fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
3645{
3646 Elf_Versym vernum;
3647
3648 if (obj->vertab) {
3649 vernum = VER_NDX(obj->versyms[symnum]);
3650 if (vernum >= obj->vernum) {
3651 _rtld_error("%s: symbol %s has wrong verneed value %d",
3652 obj->path, obj->strtab + symnum, vernum);
3653 } else if (obj->vertab[vernum].hash != 0) {
3654 return &obj->vertab[vernum];
3655 }
3656 }
3657 return NULL;
3658}
3659
3660/*
3661 * Overrides for libc_pic-provided functions.
3662 */
3663
3664int
3665__getosreldate(void)
3666{
3667 size_t len;
3668 int oid[2];
3669 int error, osrel;
3670
3671 if (osreldate != 0)
3672 return (osreldate);
3673
3674 oid[0] = CTL_KERN;
3675 oid[1] = KERN_OSRELDATE;
3676 osrel = 0;
3677 len = sizeof(osrel);
3678 error = sysctl(oid, 2, &osrel, &len, NULL, 0);
3679 if (error == 0 && osrel > 0 && len == sizeof(osrel))
3680 osreldate = osrel;
3681 return (osreldate);
3682}
3683
3684/*
3685 * No unresolved symbols for rtld.
3686 */
3687void
3688__pthread_cxa_finalize(struct dl_phdr_info *a)
3689{
3690}