2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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.
30 * Dynamic linker for ELF.
32 * John Polstra <jdp@polstra.com>.
36 #error "GCC is needed to compile this file"
39 #include <sys/param.h>
40 #include <sys/mount.h>
60 #define PATH_RTLD "/libexec/ld-elf.so.1"
62 #define PATH_RTLD "/libexec/ld-elf32.so.1"
66 typedef void (*func_ptr_type)();
67 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
70 * This structure provides a reentrant way to keep a list of objects and
71 * check which ones have already been processed in some way.
73 typedef struct Struct_DoneList {
74 const Obj_Entry **objs; /* Array of object pointers */
75 unsigned int num_alloc; /* Allocated size of the array */
76 unsigned int num_used; /* Number of array slots used */
80 * Function declarations.
82 static const char *basename(const char *);
83 static void die(void);
84 static void digest_dynamic(Obj_Entry *, int);
85 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
86 static Obj_Entry *dlcheck(void *);
87 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
88 static bool donelist_check(DoneList *, const Obj_Entry *);
89 static void errmsg_restore(char *);
90 static char *errmsg_save(void);
91 static void *fill_search_info(const char *, size_t, void *);
92 static char *find_library(const char *, const Obj_Entry *);
93 static const char *gethints(void);
94 static void init_dag(Obj_Entry *);
95 static void init_dag1(Obj_Entry *, Obj_Entry *, DoneList *);
96 static void init_rtld(caddr_t);
97 static void initlist_add_neededs(Needed_Entry *, Objlist *);
98 static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
99 static bool is_exported(const Elf_Sym *);
100 static void linkmap_add(Obj_Entry *);
101 static void linkmap_delete(Obj_Entry *);
102 static int load_needed_objects(Obj_Entry *);
103 static int load_preload_objects(void);
104 static Obj_Entry *load_object(char *);
105 static Obj_Entry *obj_from_addr(const void *);
106 static void objlist_call_fini(Objlist *);
107 static void objlist_call_init(Objlist *);
108 static void objlist_clear(Objlist *);
109 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
110 static void objlist_init(Objlist *);
111 static void objlist_push_head(Objlist *, Obj_Entry *);
112 static void objlist_push_tail(Objlist *, Obj_Entry *);
113 static void objlist_remove(Objlist *, Obj_Entry *);
114 static void objlist_remove_unref(Objlist *);
115 static void *path_enumerate(const char *, path_enum_proc, void *);
116 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *);
117 static int rtld_dirname(const char *, char *);
118 static void rtld_exit(void);
119 static char *search_library_path(const char *, const char *);
120 static const void **get_program_var_addr(const char *name);
121 static void set_program_var(const char *, const void *);
122 static const Elf_Sym *symlook_default(const char *, unsigned long,
123 const Obj_Entry *, const Obj_Entry **, bool);
124 static const Elf_Sym *symlook_list(const char *, unsigned long,
125 const Objlist *, const Obj_Entry **, bool, DoneList *);
126 static const Elf_Sym *symlook_needed(const char *, unsigned long,
127 const Needed_Entry *, const Obj_Entry **, bool, DoneList *);
128 static void trace_loaded_objects(Obj_Entry *);
129 static void unlink_object(Obj_Entry *);
130 static void unload_object(Obj_Entry *);
131 static void unref_dag(Obj_Entry *);
132 static void ref_dag(Obj_Entry *);
134 void r_debug_state(struct r_debug *, struct link_map *);
139 static char *error_message; /* Message for dlerror(), or NULL */
140 struct r_debug r_debug; /* for GDB; */
141 static bool libmap_disable; /* Disable libmap */
142 static char *libmap_override; /* Maps to use in addition to libmap.conf */
143 static bool trust; /* False for setuid and setgid programs */
144 static bool dangerous_ld_env; /* True if environment variables have been
145 used to affect the libraries loaded */
146 static char *ld_bind_now; /* Environment variable for immediate binding */
147 static char *ld_debug; /* Environment variable for debugging */
148 static char *ld_library_path; /* Environment variable for search path */
149 static char *ld_preload; /* Environment variable for libraries to
151 static char *ld_tracing; /* Called from ldd to print libs */
152 static Obj_Entry *obj_list; /* Head of linked list of shared objects */
153 static Obj_Entry **obj_tail; /* Link field of last object in list */
154 static Obj_Entry *obj_main; /* The main program shared object */
155 static Obj_Entry obj_rtld; /* The dynamic linker shared object */
156 static unsigned int obj_count; /* Number of objects in obj_list */
158 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
159 STAILQ_HEAD_INITIALIZER(list_global);
160 static Objlist list_main = /* Objects loaded at program startup */
161 STAILQ_HEAD_INITIALIZER(list_main);
162 static Objlist list_fini = /* Objects needing fini() calls */
163 STAILQ_HEAD_INITIALIZER(list_fini);
165 static Elf_Sym sym_zero; /* For resolving undefined weak refs. */
167 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
169 extern Elf_Dyn _DYNAMIC;
170 #pragma weak _DYNAMIC
171 #ifndef RTLD_IS_DYNAMIC
172 #define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL)
176 * These are the functions the dynamic linker exports to application
177 * programs. They are the only symbols the dynamic linker is willing
178 * to export from itself.
180 static func_ptr_type exports[] = {
181 (func_ptr_type) &_rtld_error,
182 (func_ptr_type) &dlclose,
183 (func_ptr_type) &dlerror,
184 (func_ptr_type) &dlopen,
185 (func_ptr_type) &dlsym,
186 (func_ptr_type) &dladdr,
187 (func_ptr_type) &dllockinit,
188 (func_ptr_type) &dlinfo,
189 (func_ptr_type) &_rtld_thread_init,
191 (func_ptr_type) &___tls_get_addr,
193 (func_ptr_type) &__tls_get_addr,
194 (func_ptr_type) &_rtld_allocate_tls,
195 (func_ptr_type) &_rtld_free_tls,
200 * Global declarations normally provided by crt1. The dynamic linker is
201 * not built with crt1, so we have to provide them ourselves.
207 * Globals to control TLS allocation.
209 size_t tls_last_offset; /* Static TLS offset of last module */
210 size_t tls_last_size; /* Static TLS size of last module */
211 size_t tls_static_space; /* Static TLS space allocated */
212 int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
213 int tls_max_index = 1; /* Largest module index allocated */
216 * Fill in a DoneList with an allocation large enough to hold all of
217 * the currently-loaded objects. Keep this as a macro since it calls
218 * alloca and we want that to occur within the scope of the caller.
220 #define donelist_init(dlp) \
221 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
222 assert((dlp)->objs != NULL), \
223 (dlp)->num_alloc = obj_count, \
227 * Main entry point for dynamic linking. The first argument is the
228 * stack pointer. The stack is expected to be laid out as described
229 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
230 * Specifically, the stack pointer points to a word containing
231 * ARGC. Following that in the stack is a null-terminated sequence
232 * of pointers to argument strings. Then comes a null-terminated
233 * sequence of pointers to environment strings. Finally, there is a
234 * sequence of "auxiliary vector" entries.
236 * The second argument points to a place to store the dynamic linker's
237 * exit procedure pointer and the third to a place to store the main
240 * The return value is the main program's entry point.
243 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
245 Elf_Auxinfo *aux_info[AT_COUNT];
253 Objlist_Entry *entry;
255 Obj_Entry **preload_tail;
260 * On entry, the dynamic linker itself has not been relocated yet.
261 * Be very careful not to reference any global data until after
262 * init_rtld has returned. It is OK to reference file-scope statics
263 * and string constants, and to call static and global functions.
266 /* Find the auxiliary vector on the stack. */
269 sp += argc + 1; /* Skip over arguments and NULL terminator */
271 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
273 aux = (Elf_Auxinfo *) sp;
275 /* Digest the auxiliary vector. */
276 for (i = 0; i < AT_COUNT; i++)
278 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
279 if (auxp->a_type < AT_COUNT)
280 aux_info[auxp->a_type] = auxp;
283 /* Initialize and relocate ourselves. */
284 assert(aux_info[AT_BASE] != NULL);
285 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
287 __progname = obj_rtld.path;
288 argv0 = argv[0] != NULL ? argv[0] : "(null)";
291 trust = !issetugid();
293 ld_bind_now = getenv(LD_ "BIND_NOW");
295 ld_debug = getenv(LD_ "DEBUG");
296 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL;
297 libmap_override = getenv(LD_ "LIBMAP");
298 ld_library_path = getenv(LD_ "LIBRARY_PATH");
299 ld_preload = getenv(LD_ "PRELOAD");
300 dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
301 (ld_library_path != NULL) || (ld_preload != NULL);
303 dangerous_ld_env = 0;
304 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS");
306 if (ld_debug != NULL && *ld_debug != '\0')
308 dbg("%s is initialized, base address = %p", __progname,
309 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
310 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
311 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
314 * Load the main program, or process its program header if it is
317 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
318 int fd = aux_info[AT_EXECFD]->a_un.a_val;
319 dbg("loading main program");
320 obj_main = map_object(fd, argv0, NULL);
322 if (obj_main == NULL)
324 } else { /* Main program already loaded. */
325 const Elf_Phdr *phdr;
329 dbg("processing main program's program header");
330 assert(aux_info[AT_PHDR] != NULL);
331 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
332 assert(aux_info[AT_PHNUM] != NULL);
333 phnum = aux_info[AT_PHNUM]->a_un.a_val;
334 assert(aux_info[AT_PHENT] != NULL);
335 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
336 assert(aux_info[AT_ENTRY] != NULL);
337 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
338 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
342 obj_main->path = xstrdup(argv0);
343 obj_main->mainprog = true;
346 * Get the actual dynamic linker pathname from the executable if
347 * possible. (It should always be possible.) That ensures that
348 * gdb will find the right dynamic linker even if a non-standard
351 if (obj_main->interp != NULL &&
352 strcmp(obj_main->interp, obj_rtld.path) != 0) {
354 obj_rtld.path = xstrdup(obj_main->interp);
355 __progname = obj_rtld.path;
358 digest_dynamic(obj_main, 0);
360 linkmap_add(obj_main);
361 linkmap_add(&obj_rtld);
363 /* Link the main program into the list of objects. */
364 *obj_tail = obj_main;
365 obj_tail = &obj_main->next;
367 /* Make sure we don't call the main program's init and fini functions. */
368 obj_main->init = obj_main->fini = (Elf_Addr)NULL;
370 /* Initialize a fake symbol for resolving undefined weak references. */
371 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
372 sym_zero.st_shndx = SHN_UNDEF;
375 libmap_disable = (bool)lm_init(libmap_override);
377 dbg("loading LD_PRELOAD libraries");
378 if (load_preload_objects() == -1)
380 preload_tail = obj_tail;
382 dbg("loading needed objects");
383 if (load_needed_objects(obj_main) == -1)
386 /* Make a list of all objects loaded at startup. */
387 for (obj = obj_list; obj != NULL; obj = obj->next) {
388 objlist_push_tail(&list_main, obj);
392 if (ld_tracing) { /* We're done */
393 trace_loaded_objects(obj_main);
397 if (getenv(LD_ "DUMP_REL_PRE") != NULL) {
398 dump_relocations(obj_main);
402 /* setup TLS for main thread */
403 dbg("initializing initial thread local storage");
404 STAILQ_FOREACH(entry, &list_main, link) {
406 * Allocate all the initial objects out of the static TLS
407 * block even if they didn't ask for it.
409 allocate_tls_offset(entry->obj);
411 allocate_initial_tls(obj_list);
413 if (relocate_objects(obj_main,
414 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
417 dbg("doing copy relocations");
418 if (do_copy_relocations(obj_main) == -1)
421 if (getenv(LD_ "DUMP_REL_POST") != NULL) {
422 dump_relocations(obj_main);
426 dbg("initializing key program variables");
427 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
428 set_program_var("environ", env);
430 dbg("initializing thread locks");
433 /* Make a list of init functions to call. */
434 objlist_init(&initlist);
435 initlist_add_objects(obj_list, preload_tail, &initlist);
437 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
439 objlist_call_init(&initlist);
440 lockstate = wlock_acquire(rtld_bind_lock);
441 objlist_clear(&initlist);
442 wlock_release(rtld_bind_lock, lockstate);
444 dbg("transferring control to program entry point = %p", obj_main->entry);
446 /* Return the exit procedure and the program entry point. */
447 *exit_proc = rtld_exit;
449 return (func_ptr_type) obj_main->entry;
453 _rtld_bind(Obj_Entry *obj, Elf_Size reloff)
457 const Obj_Entry *defobj;
462 lockstate = rlock_acquire(rtld_bind_lock);
464 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
466 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
468 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
469 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
473 target = (Elf_Addr)(defobj->relocbase + def->st_value);
475 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
476 defobj->strtab + def->st_name, basename(obj->path),
477 (void *)target, basename(defobj->path));
480 * Write the new contents for the jmpslot. Note that depending on
481 * architecture, the value which we need to return back to the
482 * lazy binding trampoline may or may not be the target
483 * address. The value returned from reloc_jmpslot() is the value
484 * that the trampoline needs.
486 target = reloc_jmpslot(where, target, defobj, obj, rel);
487 rlock_release(rtld_bind_lock, lockstate);
492 * Error reporting function. Use it like printf. If formats the message
493 * into a buffer, and sets things up so that the next call to dlerror()
494 * will return the message.
497 _rtld_error(const char *fmt, ...)
499 static char buf[512];
503 vsnprintf(buf, sizeof buf, fmt, ap);
509 * Return a dynamically-allocated copy of the current error message, if any.
514 return error_message == NULL ? NULL : xstrdup(error_message);
518 * Restore the current error message from a copy which was previously saved
519 * by errmsg_save(). The copy is freed.
522 errmsg_restore(char *saved_msg)
524 if (saved_msg == NULL)
525 error_message = NULL;
527 _rtld_error("%s", saved_msg);
533 basename(const char *name)
535 const char *p = strrchr(name, '/');
536 return p != NULL ? p + 1 : name;
542 const char *msg = dlerror();
550 * Process a shared object's DYNAMIC section, and save the important
551 * information in its Obj_Entry structure.
554 digest_dynamic(Obj_Entry *obj, int early)
557 Needed_Entry **needed_tail = &obj->needed;
558 const Elf_Dyn *dyn_rpath = NULL;
559 int plttype = DT_REL;
561 obj->bind_now = false;
562 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
563 switch (dynp->d_tag) {
566 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
570 obj->relsize = dynp->d_un.d_val;
574 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
578 obj->pltrel = (const Elf_Rel *)
579 (obj->relocbase + dynp->d_un.d_ptr);
583 obj->pltrelsize = dynp->d_un.d_val;
587 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
591 obj->relasize = dynp->d_un.d_val;
595 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
599 plttype = dynp->d_un.d_val;
600 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
604 obj->symtab = (const Elf_Sym *)
605 (obj->relocbase + dynp->d_un.d_ptr);
609 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
613 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
617 obj->strsize = dynp->d_un.d_val;
622 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
623 (obj->relocbase + dynp->d_un.d_ptr);
624 obj->nbuckets = hashtab[0];
625 obj->nchains = hashtab[1];
626 obj->buckets = hashtab + 2;
627 obj->chains = obj->buckets + obj->nbuckets;
633 Needed_Entry *nep = NEW(Needed_Entry);
634 nep->name = dynp->d_un.d_val;
639 needed_tail = &nep->next;
644 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
652 obj->symbolic = true;
656 case DT_RUNPATH: /* XXX: process separately */
658 * We have to wait until later to process this, because we
659 * might not have gotten the address of the string table yet.
665 /* Not used by the dynamic linker. */
669 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
673 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
677 /* XXX - not implemented yet */
679 dbg("Filling in DT_DEBUG entry");
680 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
684 if (dynp->d_un.d_val & DF_ORIGIN) {
685 obj->origin_path = xmalloc(PATH_MAX);
686 if (rtld_dirname(obj->path, obj->origin_path) == -1)
689 if (dynp->d_un.d_val & DF_SYMBOLIC)
690 obj->symbolic = true;
691 if (dynp->d_un.d_val & DF_TEXTREL)
693 if (dynp->d_un.d_val & DF_BIND_NOW)
694 obj->bind_now = true;
695 if (dynp->d_un.d_val & DF_STATIC_TLS)
701 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
710 if (plttype == DT_RELA) {
711 obj->pltrela = (const Elf_Rela *) obj->pltrel;
713 obj->pltrelasize = obj->pltrelsize;
717 if (dyn_rpath != NULL)
718 obj->rpath = obj->strtab + dyn_rpath->d_un.d_val;
722 * Process a shared object's program header. This is used only for the
723 * main program, when the kernel has already loaded the main program
724 * into memory before calling the dynamic linker. It creates and
725 * returns an Obj_Entry structure.
728 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
731 const Elf_Phdr *phlimit = phdr + phnum;
736 for (ph = phdr; ph < phlimit; ph++) {
737 switch (ph->p_type) {
740 if ((const Elf_Phdr *)ph->p_vaddr != phdr) {
741 _rtld_error("%s: invalid PT_PHDR", path);
744 obj->phdr = (const Elf_Phdr *) ph->p_vaddr;
745 obj->phsize = ph->p_memsz;
749 obj->interp = (const char *) ph->p_vaddr;
753 if (nsegs == 0) { /* First load segment */
754 obj->vaddrbase = trunc_page(ph->p_vaddr);
755 obj->mapbase = (caddr_t) obj->vaddrbase;
756 obj->relocbase = obj->mapbase - obj->vaddrbase;
757 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
759 } else { /* Last load segment */
760 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
767 obj->dynamic = (const Elf_Dyn *) ph->p_vaddr;
772 obj->tlssize = ph->p_memsz;
773 obj->tlsalign = ph->p_align;
774 obj->tlsinitsize = ph->p_filesz;
775 obj->tlsinit = (void*) ph->p_vaddr;
780 _rtld_error("%s: too few PT_LOAD segments", path);
789 dlcheck(void *handle)
793 for (obj = obj_list; obj != NULL; obj = obj->next)
794 if (obj == (Obj_Entry *) handle)
797 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
798 _rtld_error("Invalid shared object handle %p", handle);
805 * If the given object is already in the donelist, return true. Otherwise
806 * add the object to the list and return false.
809 donelist_check(DoneList *dlp, const Obj_Entry *obj)
813 for (i = 0; i < dlp->num_used; i++)
814 if (dlp->objs[i] == obj)
817 * Our donelist allocation should always be sufficient. But if
818 * our threads locking isn't working properly, more shared objects
819 * could have been loaded since we allocated the list. That should
820 * never happen, but we'll handle it properly just in case it does.
822 if (dlp->num_used < dlp->num_alloc)
823 dlp->objs[dlp->num_used++] = obj;
828 * Hash function for symbol table lookup. Don't even think about changing
829 * this. It is specified by the System V ABI.
832 elf_hash(const char *name)
834 const unsigned char *p = (const unsigned char *) name;
840 if ((g = h & 0xf0000000) != 0)
848 * Find the library with the given name, and return its full pathname.
849 * The returned string is dynamically allocated. Generates an error
850 * message and returns NULL if the library cannot be found.
852 * If the second argument is non-NULL, then it refers to an already-
853 * loaded shared object, whose library search path will be searched.
855 * The search order is:
857 * rpath in the referencing file
862 find_library(const char *xname, const Obj_Entry *refobj)
867 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
868 if (xname[0] != '/' && !trust) {
869 _rtld_error("Absolute pathname required for shared object \"%s\"",
873 return xstrdup(xname);
876 if (libmap_disable || (refobj == NULL) ||
877 (name = lm_find(refobj->path, xname)) == NULL)
878 name = (char *)xname;
880 dbg(" Searching for \"%s\"", name);
882 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
884 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
885 (pathname = search_library_path(name, gethints())) != NULL ||
886 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
889 if(refobj != NULL && refobj->path != NULL) {
890 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
891 name, basename(refobj->path));
893 _rtld_error("Shared object \"%s\" not found", name);
899 * Given a symbol number in a referencing object, find the corresponding
900 * definition of the symbol. Returns a pointer to the symbol, or NULL if
901 * no definition was found. Returns a pointer to the Obj_Entry of the
902 * defining object via the reference parameter DEFOBJ_OUT.
905 find_symdef(unsigned long symnum, const Obj_Entry *refobj,
906 const Obj_Entry **defobj_out, bool in_plt, SymCache *cache)
910 const Obj_Entry *defobj;
915 * If we have already found this symbol, get the information from
918 if (symnum >= refobj->nchains)
919 return NULL; /* Bad object */
920 if (cache != NULL && cache[symnum].sym != NULL) {
921 *defobj_out = cache[symnum].obj;
922 return cache[symnum].sym;
925 ref = refobj->symtab + symnum;
926 name = refobj->strtab + ref->st_name;
930 * We don't have to do a full scale lookup if the symbol is local.
931 * We know it will bind to the instance in this load module; to
932 * which we already have a pointer (ie ref). By not doing a lookup,
933 * we not only improve performance, but it also avoids unresolvable
934 * symbols when local symbols are not in the hash table. This has
935 * been seen with the ia64 toolchain.
937 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
938 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
939 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
942 hash = elf_hash(name);
943 def = symlook_default(name, hash, refobj, &defobj, in_plt);
950 * If we found no definition and the reference is weak, treat the
951 * symbol as having the value zero.
953 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
959 *defobj_out = defobj;
960 /* Record the information in the cache to avoid subsequent lookups. */
962 cache[symnum].sym = def;
963 cache[symnum].obj = defobj;
966 if (refobj != &obj_rtld)
967 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
973 * Return the search path from the ldconfig hints file, reading it if
974 * necessary. Returns NULL if there are problems with the hints file,
975 * or if the search path there is empty.
984 struct elfhints_hdr hdr;
987 /* Keep from trying again in case the hints file is bad. */
990 if ((fd = open(_PATH_ELF_HINTS, O_RDONLY)) == -1)
992 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
993 hdr.magic != ELFHINTS_MAGIC ||
998 p = xmalloc(hdr.dirlistlen + 1);
999 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1000 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) {
1008 return hints[0] != '\0' ? hints : NULL;
1012 init_dag(Obj_Entry *root)
1016 donelist_init(&donelist);
1017 init_dag1(root, root, &donelist);
1021 init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1023 const Needed_Entry *needed;
1025 if (donelist_check(dlp, obj))
1029 objlist_push_tail(&obj->dldags, root);
1030 objlist_push_tail(&root->dagmembers, obj);
1031 for (needed = obj->needed; needed != NULL; needed = needed->next)
1032 if (needed->obj != NULL)
1033 init_dag1(root, needed->obj, dlp);
1037 * Initialize the dynamic linker. The argument is the address at which
1038 * the dynamic linker has been mapped into memory. The primary task of
1039 * this function is to relocate the dynamic linker.
1042 init_rtld(caddr_t mapbase)
1044 Obj_Entry objtmp; /* Temporary rtld object */
1047 * Conjure up an Obj_Entry structure for the dynamic linker.
1049 * The "path" member can't be initialized yet because string constatns
1050 * cannot yet be acessed. Below we will set it correctly.
1052 memset(&objtmp, 0, sizeof(objtmp));
1055 objtmp.mapbase = mapbase;
1057 objtmp.relocbase = mapbase;
1059 if (RTLD_IS_DYNAMIC()) {
1060 objtmp.dynamic = rtld_dynamic(&objtmp);
1061 digest_dynamic(&objtmp, 1);
1062 assert(objtmp.needed == NULL);
1063 assert(!objtmp.textrel);
1066 * Temporarily put the dynamic linker entry into the object list, so
1067 * that symbols can be found.
1070 relocate_objects(&objtmp, true, &objtmp);
1073 /* Initialize the object list. */
1074 obj_tail = &obj_list;
1076 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1077 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
1079 /* Replace the path with a dynamically allocated copy. */
1080 obj_rtld.path = xstrdup(PATH_RTLD);
1082 r_debug.r_brk = r_debug_state;
1083 r_debug.r_state = RT_CONSISTENT;
1087 * Add the init functions from a needed object list (and its recursive
1088 * needed objects) to "list". This is not used directly; it is a helper
1089 * function for initlist_add_objects(). The write lock must be held
1090 * when this function is called.
1093 initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1095 /* Recursively process the successor needed objects. */
1096 if (needed->next != NULL)
1097 initlist_add_neededs(needed->next, list);
1099 /* Process the current needed object. */
1100 if (needed->obj != NULL)
1101 initlist_add_objects(needed->obj, &needed->obj->next, list);
1105 * Scan all of the DAGs rooted in the range of objects from "obj" to
1106 * "tail" and add their init functions to "list". This recurses over
1107 * the DAGs and ensure the proper init ordering such that each object's
1108 * needed libraries are initialized before the object itself. At the
1109 * same time, this function adds the objects to the global finalization
1110 * list "list_fini" in the opposite order. The write lock must be
1111 * held when this function is called.
1114 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1118 obj->init_done = true;
1120 /* Recursively process the successor objects. */
1121 if (&obj->next != tail)
1122 initlist_add_objects(obj->next, tail, list);
1124 /* Recursively process the needed objects. */
1125 if (obj->needed != NULL)
1126 initlist_add_neededs(obj->needed, list);
1128 /* Add the object to the init list. */
1129 if (obj->init != (Elf_Addr)NULL)
1130 objlist_push_tail(list, obj);
1132 /* Add the object to the global fini list in the reverse order. */
1133 if (obj->fini != (Elf_Addr)NULL)
1134 objlist_push_head(&list_fini, obj);
1138 #define FPTR_TARGET(f) ((Elf_Addr) (f))
1142 is_exported(const Elf_Sym *def)
1145 const func_ptr_type *p;
1147 value = (Elf_Addr)(obj_rtld.relocbase + def->st_value);
1148 for (p = exports; *p != NULL; p++)
1149 if (FPTR_TARGET(*p) == value)
1155 * Given a shared object, traverse its list of needed objects, and load
1156 * each of them. Returns 0 on success. Generates an error message and
1157 * returns -1 on failure.
1160 load_needed_objects(Obj_Entry *first)
1164 for (obj = first; obj != NULL; obj = obj->next) {
1165 Needed_Entry *needed;
1167 for (needed = obj->needed; needed != NULL; needed = needed->next) {
1168 const char *name = obj->strtab + needed->name;
1169 char *path = find_library(name, obj);
1172 if (path == NULL && !ld_tracing)
1176 needed->obj = load_object(path);
1177 if (needed->obj == NULL && !ld_tracing)
1178 return -1; /* XXX - cleanup */
1187 load_preload_objects(void)
1189 char *p = ld_preload;
1190 static const char delim[] = " \t:;";
1195 p += strspn(p, delim);
1196 while (*p != '\0') {
1197 size_t len = strcspn(p, delim);
1203 if ((path = find_library(p, NULL)) == NULL)
1205 if (load_object(path) == NULL)
1206 return -1; /* XXX - cleanup */
1209 p += strspn(p, delim);
1215 * Load a shared object into memory, if it is not already loaded. The
1216 * argument must be a string allocated on the heap. This function assumes
1217 * responsibility for freeing it when necessary.
1219 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1223 load_object(char *path)
1230 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1231 if (strcmp(obj->path, path) == 0)
1235 * If we didn't find a match by pathname, open the file and check
1236 * again by device and inode. This avoids false mismatches caused
1237 * by multiple links or ".." in pathnames.
1239 * To avoid a race, we open the file and use fstat() rather than
1243 if ((fd = open(path, O_RDONLY)) == -1) {
1244 _rtld_error("Cannot open \"%s\"", path);
1247 if (fstat(fd, &sb) == -1) {
1248 _rtld_error("Cannot fstat \"%s\"", path);
1252 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
1253 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) {
1260 if (obj == NULL) { /* First use of this object, so we must map it in */
1262 * but first, make sure that environment variables haven't been
1263 * used to circumvent the noexec flag on a filesystem.
1265 if (dangerous_ld_env) {
1266 if (fstatfs(fd, &fs) != 0) {
1267 _rtld_error("Cannot fstatfs \"%s\"", path);
1271 if (fs.f_flags & MNT_NOEXEC) {
1272 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
1277 dbg("loading \"%s\"", path);
1278 obj = map_object(fd, path, &sb);
1286 digest_dynamic(obj, 0);
1289 obj_tail = &obj->next;
1291 linkmap_add(obj); /* for GDB & dlinfo() */
1293 dbg(" %p .. %p: %s", obj->mapbase,
1294 obj->mapbase + obj->mapsize - 1, obj->path);
1296 dbg(" WARNING: %s has impure text", obj->path);
1304 obj_from_addr(const void *addr)
1308 for (obj = obj_list; obj != NULL; obj = obj->next) {
1309 if (addr < (void *) obj->mapbase)
1311 if (addr < (void *) (obj->mapbase + obj->mapsize))
1318 * Call the finalization functions for each of the objects in "list"
1319 * which are unreferenced. All of the objects are expected to have
1320 * non-NULL fini functions.
1323 objlist_call_fini(Objlist *list)
1329 * Preserve the current error message since a fini function might
1330 * call into the dynamic linker and overwrite it.
1332 saved_msg = errmsg_save();
1333 STAILQ_FOREACH(elm, list, link) {
1334 if (elm->obj->refcount == 0) {
1335 dbg("calling fini function for %s at %p", elm->obj->path,
1336 (void *)elm->obj->fini);
1337 call_initfini_pointer(elm->obj, elm->obj->fini);
1340 errmsg_restore(saved_msg);
1344 * Call the initialization functions for each of the objects in
1345 * "list". All of the objects are expected to have non-NULL init
1349 objlist_call_init(Objlist *list)
1355 * Preserve the current error message since an init function might
1356 * call into the dynamic linker and overwrite it.
1358 saved_msg = errmsg_save();
1359 STAILQ_FOREACH(elm, list, link) {
1360 dbg("calling init function for %s at %p", elm->obj->path,
1361 (void *)elm->obj->init);
1362 call_initfini_pointer(elm->obj, elm->obj->init);
1364 errmsg_restore(saved_msg);
1368 objlist_clear(Objlist *list)
1372 while (!STAILQ_EMPTY(list)) {
1373 elm = STAILQ_FIRST(list);
1374 STAILQ_REMOVE_HEAD(list, link);
1379 static Objlist_Entry *
1380 objlist_find(Objlist *list, const Obj_Entry *obj)
1384 STAILQ_FOREACH(elm, list, link)
1385 if (elm->obj == obj)
1391 objlist_init(Objlist *list)
1397 objlist_push_head(Objlist *list, Obj_Entry *obj)
1401 elm = NEW(Objlist_Entry);
1403 STAILQ_INSERT_HEAD(list, elm, link);
1407 objlist_push_tail(Objlist *list, Obj_Entry *obj)
1411 elm = NEW(Objlist_Entry);
1413 STAILQ_INSERT_TAIL(list, elm, link);
1417 objlist_remove(Objlist *list, Obj_Entry *obj)
1421 if ((elm = objlist_find(list, obj)) != NULL) {
1422 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1428 * Remove all of the unreferenced objects from "list".
1431 objlist_remove_unref(Objlist *list)
1436 STAILQ_INIT(&newlist);
1437 while (!STAILQ_EMPTY(list)) {
1438 elm = STAILQ_FIRST(list);
1439 STAILQ_REMOVE_HEAD(list, link);
1440 if (elm->obj->refcount == 0)
1443 STAILQ_INSERT_TAIL(&newlist, elm, link);
1449 * Relocate newly-loaded shared objects. The argument is a pointer to
1450 * the Obj_Entry for the first such object. All objects from the first
1451 * to the end of the list of objects are relocated. Returns 0 on success,
1455 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
1459 for (obj = first; obj != NULL; obj = obj->next) {
1461 dbg("relocating \"%s\"", obj->path);
1462 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1463 obj->symtab == NULL || obj->strtab == NULL) {
1464 _rtld_error("%s: Shared object has no run-time symbol table",
1470 /* There are relocations to the write-protected text segment. */
1471 if (mprotect(obj->mapbase, obj->textsize,
1472 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1473 _rtld_error("%s: Cannot write-enable text segment: %s",
1474 obj->path, strerror(errno));
1479 /* Process the non-PLT relocations. */
1480 if (reloc_non_plt(obj, rtldobj))
1483 if (obj->textrel) { /* Re-protected the text segment. */
1484 if (mprotect(obj->mapbase, obj->textsize,
1485 PROT_READ|PROT_EXEC) == -1) {
1486 _rtld_error("%s: Cannot write-protect text segment: %s",
1487 obj->path, strerror(errno));
1492 /* Process the PLT relocations. */
1493 if (reloc_plt(obj) == -1)
1495 /* Relocate the jump slots if we are doing immediate binding. */
1496 if (obj->bind_now || bind_now)
1497 if (reloc_jmpslots(obj) == -1)
1502 * Set up the magic number and version in the Obj_Entry. These
1503 * were checked in the crt1.o from the original ElfKit, so we
1504 * set them for backward compatibility.
1506 obj->magic = RTLD_MAGIC;
1507 obj->version = RTLD_VERSION;
1509 /* Set the special PLT or GOT entries. */
1517 * Cleanup procedure. It will be called (by the atexit mechanism) just
1518 * before the process exits.
1526 /* Clear all the reference counts so the fini functions will be called. */
1527 for (obj = obj_list; obj != NULL; obj = obj->next)
1529 objlist_call_fini(&list_fini);
1530 /* No need to remove the items from the list, since we are exiting. */
1531 if (!libmap_disable)
1536 path_enumerate(const char *path, path_enum_proc callback, void *arg)
1544 path += strspn(path, ":;");
1545 while (*path != '\0') {
1549 len = strcspn(path, ":;");
1551 trans = lm_findn(NULL, path, len);
1553 res = callback(trans, strlen(trans), arg);
1556 res = callback(path, len, arg);
1562 path += strspn(path, ":;");
1568 struct try_library_args {
1576 try_library_path(const char *dir, size_t dirlen, void *param)
1578 struct try_library_args *arg;
1581 if (*dir == '/' || trust) {
1584 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
1587 pathname = arg->buffer;
1588 strncpy(pathname, dir, dirlen);
1589 pathname[dirlen] = '/';
1590 strcpy(pathname + dirlen + 1, arg->name);
1592 dbg(" Trying \"%s\"", pathname);
1593 if (access(pathname, F_OK) == 0) { /* We found it */
1594 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
1595 strcpy(pathname, arg->buffer);
1603 search_library_path(const char *name, const char *path)
1606 struct try_library_args arg;
1612 arg.namelen = strlen(name);
1613 arg.buffer = xmalloc(PATH_MAX);
1614 arg.buflen = PATH_MAX;
1616 p = path_enumerate(path, try_library_path, &arg);
1624 dlclose(void *handle)
1629 lockstate = wlock_acquire(rtld_bind_lock);
1630 root = dlcheck(handle);
1632 wlock_release(rtld_bind_lock, lockstate);
1636 /* Unreference the object and its dependencies. */
1637 root->dl_refcount--;
1641 if (root->refcount == 0) {
1643 * The object is no longer referenced, so we must unload it.
1644 * First, call the fini functions with no locks held.
1646 wlock_release(rtld_bind_lock, lockstate);
1647 objlist_call_fini(&list_fini);
1648 lockstate = wlock_acquire(rtld_bind_lock);
1649 objlist_remove_unref(&list_fini);
1651 /* Finish cleaning up the newly-unreferenced objects. */
1652 GDB_STATE(RT_DELETE,&root->linkmap);
1653 unload_object(root);
1654 GDB_STATE(RT_CONSISTENT,NULL);
1656 wlock_release(rtld_bind_lock, lockstate);
1663 char *msg = error_message;
1664 error_message = NULL;
1669 * This function is deprecated and has no effect.
1672 dllockinit(void *context,
1673 void *(*lock_create)(void *context),
1674 void (*rlock_acquire)(void *lock),
1675 void (*wlock_acquire)(void *lock),
1676 void (*lock_release)(void *lock),
1677 void (*lock_destroy)(void *lock),
1678 void (*context_destroy)(void *context))
1680 static void *cur_context;
1681 static void (*cur_context_destroy)(void *);
1683 /* Just destroy the context from the previous call, if necessary. */
1684 if (cur_context_destroy != NULL)
1685 cur_context_destroy(cur_context);
1686 cur_context = context;
1687 cur_context_destroy = context_destroy;
1691 dlopen(const char *name, int mode)
1693 Obj_Entry **old_obj_tail;
1696 int result, lockstate;
1698 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
1699 if (ld_tracing != NULL)
1700 environ = (char **)*get_program_var_addr("environ");
1702 objlist_init(&initlist);
1704 lockstate = wlock_acquire(rtld_bind_lock);
1705 GDB_STATE(RT_ADD,NULL);
1707 old_obj_tail = obj_tail;
1713 char *path = find_library(name, obj_main);
1715 obj = load_object(path);
1720 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
1721 objlist_push_tail(&list_global, obj);
1722 mode &= RTLD_MODEMASK;
1723 if (*old_obj_tail != NULL) { /* We loaded something new. */
1724 assert(*old_obj_tail == obj);
1726 result = load_needed_objects(obj);
1727 if (result != -1 && ld_tracing)
1731 (init_dag(obj), relocate_objects(obj, mode == RTLD_NOW,
1732 &obj_rtld)) == -1) {
1735 if (obj->refcount == 0)
1739 /* Make list of init functions to call. */
1740 initlist_add_objects(obj, &obj->next, &initlist);
1744 /* Bump the reference counts for objects on this DAG. */
1752 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
1754 /* Call the init functions with no locks held. */
1755 wlock_release(rtld_bind_lock, lockstate);
1756 objlist_call_init(&initlist);
1757 lockstate = wlock_acquire(rtld_bind_lock);
1758 objlist_clear(&initlist);
1759 wlock_release(rtld_bind_lock, lockstate);
1762 trace_loaded_objects(obj);
1763 wlock_release(rtld_bind_lock, lockstate);
1768 dlsym(void *handle, const char *name)
1771 const Obj_Entry *obj, *defobj;
1776 hash = elf_hash(name);
1780 lockstate = rlock_acquire(rtld_bind_lock);
1781 if (handle == NULL || handle == RTLD_NEXT ||
1782 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
1785 retaddr = __builtin_return_address(0); /* __GNUC__ only */
1786 if ((obj = obj_from_addr(retaddr)) == NULL) {
1787 _rtld_error("Cannot determine caller's shared object");
1788 rlock_release(rtld_bind_lock, lockstate);
1791 if (handle == NULL) { /* Just the caller's shared object. */
1792 def = symlook_obj(name, hash, obj, true);
1794 } else if (handle == RTLD_NEXT || /* Objects after caller's */
1795 handle == RTLD_SELF) { /* ... caller included */
1796 if (handle == RTLD_NEXT)
1798 for (; obj != NULL; obj = obj->next) {
1799 if ((def = symlook_obj(name, hash, obj, true)) != NULL) {
1805 assert(handle == RTLD_DEFAULT);
1806 def = symlook_default(name, hash, obj, &defobj, true);
1809 if ((obj = dlcheck(handle)) == NULL) {
1810 rlock_release(rtld_bind_lock, lockstate);
1814 donelist_init(&donelist);
1815 if (obj->mainprog) {
1816 /* Search main program and all libraries loaded by it. */
1817 def = symlook_list(name, hash, &list_main, &defobj, true,
1822 /* Search the whole DAG rooted at the given object. */
1824 fake.obj = (Obj_Entry *)obj;
1826 def = symlook_needed(name, hash, &fake, &defobj, true,
1832 rlock_release(rtld_bind_lock, lockstate);
1835 * The value required by the caller is derived from the value
1836 * of the symbol. For the ia64 architecture, we need to
1837 * construct a function descriptor which the caller can use to
1838 * call the function with the right 'gp' value. For other
1839 * architectures and for non-functions, the value is simply
1840 * the relocated value of the symbol.
1842 if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
1843 return make_function_pointer(def, defobj);
1845 return defobj->relocbase + def->st_value;
1848 _rtld_error("Undefined symbol \"%s\"", name);
1849 rlock_release(rtld_bind_lock, lockstate);
1854 dladdr(const void *addr, Dl_info *info)
1856 const Obj_Entry *obj;
1859 unsigned long symoffset;
1862 lockstate = rlock_acquire(rtld_bind_lock);
1863 obj = obj_from_addr(addr);
1865 _rtld_error("No shared object contains address");
1866 rlock_release(rtld_bind_lock, lockstate);
1869 info->dli_fname = obj->path;
1870 info->dli_fbase = obj->mapbase;
1871 info->dli_saddr = (void *)0;
1872 info->dli_sname = NULL;
1875 * Walk the symbol list looking for the symbol whose address is
1876 * closest to the address sent in.
1878 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
1879 def = obj->symtab + symoffset;
1882 * For skip the symbol if st_shndx is either SHN_UNDEF or
1885 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
1889 * If the symbol is greater than the specified address, or if it
1890 * is further away from addr than the current nearest symbol,
1893 symbol_addr = obj->relocbase + def->st_value;
1894 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
1897 /* Update our idea of the nearest symbol. */
1898 info->dli_sname = obj->strtab + def->st_name;
1899 info->dli_saddr = symbol_addr;
1902 if (info->dli_saddr == addr)
1905 rlock_release(rtld_bind_lock, lockstate);
1910 dlinfo(void *handle, int request, void *p)
1912 const Obj_Entry *obj;
1913 int error, lockstate;
1915 lockstate = rlock_acquire(rtld_bind_lock);
1917 if (handle == NULL || handle == RTLD_SELF) {
1920 retaddr = __builtin_return_address(0); /* __GNUC__ only */
1921 if ((obj = obj_from_addr(retaddr)) == NULL)
1922 _rtld_error("Cannot determine caller's shared object");
1924 obj = dlcheck(handle);
1927 rlock_release(rtld_bind_lock, lockstate);
1933 case RTLD_DI_LINKMAP:
1934 *((struct link_map const **)p) = &obj->linkmap;
1936 case RTLD_DI_ORIGIN:
1937 error = rtld_dirname(obj->path, p);
1940 case RTLD_DI_SERINFOSIZE:
1941 case RTLD_DI_SERINFO:
1942 error = do_search_info(obj, request, (struct dl_serinfo *)p);
1946 _rtld_error("Invalid request %d passed to dlinfo()", request);
1950 rlock_release(rtld_bind_lock, lockstate);
1955 struct fill_search_info_args {
1958 Dl_serinfo *serinfo;
1959 Dl_serpath *serpath;
1964 fill_search_info(const char *dir, size_t dirlen, void *param)
1966 struct fill_search_info_args *arg;
1970 if (arg->request == RTLD_DI_SERINFOSIZE) {
1971 arg->serinfo->dls_cnt ++;
1972 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1;
1974 struct dl_serpath *s_entry;
1976 s_entry = arg->serpath;
1977 s_entry->dls_name = arg->strspace;
1978 s_entry->dls_flags = arg->flags;
1980 strncpy(arg->strspace, dir, dirlen);
1981 arg->strspace[dirlen] = '\0';
1983 arg->strspace += dirlen + 1;
1991 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
1993 struct dl_serinfo _info;
1994 struct fill_search_info_args args;
1996 args.request = RTLD_DI_SERINFOSIZE;
1997 args.serinfo = &_info;
1999 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2002 path_enumerate(ld_library_path, fill_search_info, &args);
2003 path_enumerate(obj->rpath, fill_search_info, &args);
2004 path_enumerate(gethints(), fill_search_info, &args);
2005 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2008 if (request == RTLD_DI_SERINFOSIZE) {
2009 info->dls_size = _info.dls_size;
2010 info->dls_cnt = _info.dls_cnt;
2014 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2015 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2019 args.request = RTLD_DI_SERINFO;
2020 args.serinfo = info;
2021 args.serpath = &info->dls_serpath[0];
2022 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2024 args.flags = LA_SER_LIBPATH;
2025 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2028 args.flags = LA_SER_RUNPATH;
2029 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2032 args.flags = LA_SER_CONFIG;
2033 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2036 args.flags = LA_SER_DEFAULT;
2037 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2043 rtld_dirname(const char *path, char *bname)
2047 /* Empty or NULL string gets treated as "." */
2048 if (path == NULL || *path == '\0') {
2054 /* Strip trailing slashes */
2055 endp = path + strlen(path) - 1;
2056 while (endp > path && *endp == '/')
2059 /* Find the start of the dir */
2060 while (endp > path && *endp != '/')
2063 /* Either the dir is "/" or there are no slashes */
2065 bname[0] = *endp == '/' ? '/' : '.';
2071 } while (endp > path && *endp == '/');
2074 if (endp - path + 2 > PATH_MAX)
2076 _rtld_error("Filename is too long: %s", path);
2080 strncpy(bname, path, endp - path + 1);
2081 bname[endp - path + 1] = '\0';
2086 linkmap_add(Obj_Entry *obj)
2088 struct link_map *l = &obj->linkmap;
2089 struct link_map *prev;
2091 obj->linkmap.l_name = obj->path;
2092 obj->linkmap.l_addr = obj->mapbase;
2093 obj->linkmap.l_ld = obj->dynamic;
2095 /* GDB needs load offset on MIPS to use the symbols */
2096 obj->linkmap.l_offs = obj->relocbase;
2099 if (r_debug.r_map == NULL) {
2105 * Scan to the end of the list, but not past the entry for the
2106 * dynamic linker, which we want to keep at the very end.
2108 for (prev = r_debug.r_map;
2109 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2110 prev = prev->l_next)
2113 /* Link in the new entry. */
2115 l->l_next = prev->l_next;
2116 if (l->l_next != NULL)
2117 l->l_next->l_prev = l;
2122 linkmap_delete(Obj_Entry *obj)
2124 struct link_map *l = &obj->linkmap;
2126 if (l->l_prev == NULL) {
2127 if ((r_debug.r_map = l->l_next) != NULL)
2128 l->l_next->l_prev = NULL;
2132 if ((l->l_prev->l_next = l->l_next) != NULL)
2133 l->l_next->l_prev = l->l_prev;
2137 * Function for the debugger to set a breakpoint on to gain control.
2139 * The two parameters allow the debugger to easily find and determine
2140 * what the runtime loader is doing and to whom it is doing it.
2142 * When the loadhook trap is hit (r_debug_state, set at program
2143 * initialization), the arguments can be found on the stack:
2145 * +8 struct link_map *m
2146 * +4 struct r_debug *rd
2150 r_debug_state(struct r_debug* rd, struct link_map *m)
2155 * Get address of the pointer variable in the main program.
2157 static const void **
2158 get_program_var_addr(const char *name)
2160 const Obj_Entry *obj;
2163 hash = elf_hash(name);
2164 for (obj = obj_main; obj != NULL; obj = obj->next) {
2167 if ((def = symlook_obj(name, hash, obj, false)) != NULL) {
2170 addr = (const void **)(obj->relocbase + def->st_value);
2178 * Set a pointer variable in the main program to the given value. This
2179 * is used to set key variables such as "environ" before any of the
2180 * init functions are called.
2183 set_program_var(const char *name, const void *value)
2187 if ((addr = get_program_var_addr(name)) != NULL) {
2188 dbg("\"%s\": *%p <-- %p", name, addr, value);
2194 * Given a symbol name in a referencing object, find the corresponding
2195 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2196 * no definition was found. Returns a pointer to the Obj_Entry of the
2197 * defining object via the reference parameter DEFOBJ_OUT.
2199 static const Elf_Sym *
2200 symlook_default(const char *name, unsigned long hash,
2201 const Obj_Entry *refobj, const Obj_Entry **defobj_out, bool in_plt)
2205 const Elf_Sym *symp;
2206 const Obj_Entry *obj;
2207 const Obj_Entry *defobj;
2208 const Objlist_Entry *elm;
2211 donelist_init(&donelist);
2213 /* Look first in the referencing object if linked symbolically. */
2214 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
2215 symp = symlook_obj(name, hash, refobj, in_plt);
2222 /* Search all objects loaded at program start up. */
2223 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2224 symp = symlook_list(name, hash, &list_main, &obj, in_plt, &donelist);
2226 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2232 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2233 STAILQ_FOREACH(elm, &list_global, link) {
2234 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2236 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2239 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2245 /* Search all dlopened DAGs containing the referencing object. */
2246 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2247 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2249 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, in_plt,
2252 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2259 * Search the dynamic linker itself, and possibly resolve the
2260 * symbol from there. This is how the application links to
2261 * dynamic linker services such as dlopen. Only the values listed
2262 * in the "exports" array can be resolved from the dynamic linker.
2264 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2265 symp = symlook_obj(name, hash, &obj_rtld, in_plt);
2266 if (symp != NULL && is_exported(symp)) {
2273 *defobj_out = defobj;
2277 static const Elf_Sym *
2278 symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
2279 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2281 const Elf_Sym *symp;
2283 const Obj_Entry *defobj;
2284 const Objlist_Entry *elm;
2288 STAILQ_FOREACH(elm, objlist, link) {
2289 if (donelist_check(dlp, elm->obj))
2291 if ((symp = symlook_obj(name, hash, elm->obj, in_plt)) != NULL) {
2292 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2295 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2301 *defobj_out = defobj;
2306 * Search the symbol table of a shared object and all objects needed
2307 * by it for a symbol of the given name. Search order is
2308 * breadth-first. Returns a pointer to the symbol, or NULL if no
2309 * definition was found.
2311 static const Elf_Sym *
2312 symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
2313 const Obj_Entry **defobj_out, bool in_plt, DoneList *dlp)
2315 const Elf_Sym *def, *def_w;
2316 const Needed_Entry *n;
2317 const Obj_Entry *obj, *defobj, *defobj1;
2321 for (n = needed; n != NULL; n = n->next) {
2322 if ((obj = n->obj) == NULL ||
2323 donelist_check(dlp, obj) ||
2324 (def = symlook_obj(name, hash, obj, in_plt)) == NULL)
2327 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2328 *defobj_out = defobj;
2333 * There we come when either symbol definition is not found in
2334 * directly needed objects, or found symbol is weak.
2336 for (n = needed; n != NULL; n = n->next) {
2337 if ((obj = n->obj) == NULL)
2339 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
2343 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
2347 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
2351 *defobj_out = defobj;
2356 * Search the symbol table of a single shared object for a symbol of
2357 * the given name. Returns a pointer to the symbol, or NULL if no
2358 * definition was found.
2360 * The symbol's hash value is passed in for efficiency reasons; that
2361 * eliminates many recomputations of the hash value.
2364 symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
2367 if (obj->buckets != NULL) {
2368 unsigned long symnum = obj->buckets[hash % obj->nbuckets];
2370 while (symnum != STN_UNDEF) {
2371 const Elf_Sym *symp;
2374 if (symnum >= obj->nchains)
2375 return NULL; /* Bad object */
2376 symp = obj->symtab + symnum;
2377 strp = obj->strtab + symp->st_name;
2379 if (name[0] == strp[0] && strcmp(name, strp) == 0)
2380 return symp->st_shndx != SHN_UNDEF ||
2381 (!in_plt && symp->st_value != 0 &&
2382 ELF_ST_TYPE(symp->st_info) == STT_FUNC) ? symp : NULL;
2384 symnum = obj->chains[symnum];
2391 trace_loaded_objects(Obj_Entry *obj)
2393 char *fmt1, *fmt2, *fmt, *main_local, *list_containers;
2396 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
2399 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL)
2400 fmt1 = "\t%o => %p (%x)\n";
2402 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL)
2403 fmt2 = "\t%o (%x)\n";
2405 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL");
2407 for (; obj; obj = obj->next) {
2408 Needed_Entry *needed;
2412 if (list_containers && obj->needed != NULL)
2413 printf("%s:\n", obj->path);
2414 for (needed = obj->needed; needed; needed = needed->next) {
2415 if (needed->obj != NULL) {
2416 if (needed->obj->traced && !list_containers)
2418 needed->obj->traced = true;
2419 path = needed->obj->path;
2423 name = (char *)obj->strtab + needed->name;
2424 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
2426 fmt = is_lib ? fmt1 : fmt2;
2427 while ((c = *fmt++) != '\0') {
2453 printf("%s", main_local);
2456 printf("%s", obj_main->path);
2463 printf("%d", sodp->sod_major);
2466 printf("%d", sodp->sod_minor);
2473 printf("%p", needed->obj ? needed->obj->mapbase : 0);
2485 * Unload a dlopened object and its dependencies from memory and from
2486 * our data structures. It is assumed that the DAG rooted in the
2487 * object has already been unreferenced, and that the object has a
2488 * reference count of 0.
2491 unload_object(Obj_Entry *root)
2496 assert(root->refcount == 0);
2499 * Pass over the DAG removing unreferenced objects from
2500 * appropriate lists.
2502 unlink_object(root);
2504 /* Unmap all objects that are no longer referenced. */
2505 linkp = &obj_list->next;
2506 while ((obj = *linkp) != NULL) {
2507 if (obj->refcount == 0) {
2508 dbg("unloading \"%s\"", obj->path);
2509 munmap(obj->mapbase, obj->mapsize);
2510 linkmap_delete(obj);
2521 unlink_object(Obj_Entry *root)
2525 if (root->refcount == 0) {
2526 /* Remove the object from the RTLD_GLOBAL list. */
2527 objlist_remove(&list_global, root);
2529 /* Remove the object from all objects' DAG lists. */
2530 STAILQ_FOREACH(elm, &root->dagmembers , link) {
2531 objlist_remove(&elm->obj->dldags, root);
2532 if (elm->obj != root)
2533 unlink_object(elm->obj);
2539 ref_dag(Obj_Entry *root)
2543 STAILQ_FOREACH(elm, &root->dagmembers , link)
2544 elm->obj->refcount++;
2548 unref_dag(Obj_Entry *root)
2552 STAILQ_FOREACH(elm, &root->dagmembers , link)
2553 elm->obj->refcount--;
2557 * Common code for MD __tls_get_addr().
2560 tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset)
2562 Elf_Addr* dtv = *dtvp;
2565 /* Check dtv generation in case new modules have arrived */
2566 if (dtv[0] != tls_dtv_generation) {
2570 lockstate = wlock_acquire(rtld_bind_lock);
2571 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
2573 if (to_copy > tls_max_index)
2574 to_copy = tls_max_index;
2575 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
2576 newdtv[0] = tls_dtv_generation;
2577 newdtv[1] = tls_max_index;
2579 wlock_release(rtld_bind_lock, lockstate);
2583 /* Dynamically allocate module TLS if necessary */
2584 if (!dtv[index + 1]) {
2585 /* Signal safe, wlock will block out signals. */
2586 lockstate = wlock_acquire(rtld_bind_lock);
2587 if (!dtv[index + 1])
2588 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
2589 wlock_release(rtld_bind_lock, lockstate);
2591 return (void*) (dtv[index + 1] + offset);
2594 /* XXX not sure what variants to use for arm. */
2596 #if defined(__ia64__) || defined(__alpha__) || defined(__powerpc__)
2599 * Allocate Static TLS using the Variant I method.
2602 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
2611 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
2614 assert(tcbsize >= TLS_TCB_SIZE);
2615 tcb = calloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
2616 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
2618 if (oldtcb != NULL) {
2619 memcpy(tls, oldtcb, tls_static_space);
2622 /* Adjust the DTV. */
2624 for (i = 0; i < dtv[1]; i++) {
2625 if (dtv[i+2] >= (Elf_Addr)oldtcb &&
2626 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
2627 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
2631 dtv = calloc(tls_max_index + 2, sizeof(Elf_Addr));
2633 dtv[0] = tls_dtv_generation;
2634 dtv[1] = tls_max_index;
2636 for (obj = objs; obj; obj = obj->next) {
2637 if (obj->tlsoffset) {
2638 addr = (Elf_Addr)tls + obj->tlsoffset;
2639 memset((void*) (addr + obj->tlsinitsize),
2640 0, obj->tlssize - obj->tlsinitsize);
2642 memcpy((void*) addr, obj->tlsinit,
2644 dtv[obj->tlsindex + 1] = addr;
2653 free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
2656 Elf_Addr tlsstart, tlsend;
2659 assert(tcbsize >= TLS_TCB_SIZE);
2661 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
2662 tlsend = tlsstart + tls_static_space;
2664 dtv = *(Elf_Addr **)tlsstart;
2666 for (i = 0; i < dtvsize; i++) {
2667 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
2668 free((void*)dtv[i+2]);
2677 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \
2681 * Allocate Static TLS using the Variant II method.
2684 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
2689 Elf_Addr *dtv, *olddtv;
2690 Elf_Addr segbase, oldsegbase, addr;
2693 size = round(tls_static_space, tcbalign);
2695 assert(tcbsize >= 2*sizeof(Elf_Addr));
2696 tls = malloc(size + tcbsize);
2697 dtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
2699 segbase = (Elf_Addr)(tls + size);
2700 ((Elf_Addr*)segbase)[0] = segbase;
2701 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
2703 dtv[0] = tls_dtv_generation;
2704 dtv[1] = tls_max_index;
2708 * Copy the static TLS block over whole.
2710 oldsegbase = (Elf_Addr) oldtls;
2711 memcpy((void *)(segbase - tls_static_space),
2712 (const void *)(oldsegbase - tls_static_space),
2716 * If any dynamic TLS blocks have been created tls_get_addr(),
2719 olddtv = ((Elf_Addr**)oldsegbase)[1];
2720 for (i = 0; i < olddtv[1]; i++) {
2721 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
2722 dtv[i+2] = olddtv[i+2];
2728 * We assume that this block was the one we created with
2729 * allocate_initial_tls().
2731 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
2733 for (obj = objs; obj; obj = obj->next) {
2734 if (obj->tlsoffset) {
2735 addr = segbase - obj->tlsoffset;
2736 memset((void*) (addr + obj->tlsinitsize),
2737 0, obj->tlssize - obj->tlsinitsize);
2739 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
2740 dtv[obj->tlsindex + 1] = addr;
2745 return (void*) segbase;
2749 free_tls(void *tls, size_t tcbsize, size_t tcbalign)
2754 Elf_Addr tlsstart, tlsend;
2757 * Figure out the size of the initial TLS block so that we can
2758 * find stuff which ___tls_get_addr() allocated dynamically.
2760 size = round(tls_static_space, tcbalign);
2762 dtv = ((Elf_Addr**)tls)[1];
2764 tlsend = (Elf_Addr) tls;
2765 tlsstart = tlsend - size;
2766 for (i = 0; i < dtvsize; i++) {
2767 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] > tlsend)) {
2768 free((void*) dtv[i+2]);
2772 free((void*) tlsstart);
2778 * Allocate TLS block for module with given index.
2781 allocate_module_tls(int index)
2786 for (obj = obj_list; obj; obj = obj->next) {
2787 if (obj->tlsindex == index)
2791 _rtld_error("Can't find module with TLS index %d", index);
2795 p = malloc(obj->tlssize);
2796 memcpy(p, obj->tlsinit, obj->tlsinitsize);
2797 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
2803 allocate_tls_offset(Obj_Entry *obj)
2810 if (obj->tlssize == 0) {
2811 obj->tls_done = true;
2815 if (obj->tlsindex == 1)
2816 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
2818 off = calculate_tls_offset(tls_last_offset, tls_last_size,
2819 obj->tlssize, obj->tlsalign);
2822 * If we have already fixed the size of the static TLS block, we
2823 * must stay within that size. When allocating the static TLS, we
2824 * leave a small amount of space spare to be used for dynamically
2825 * loading modules which use static TLS.
2827 if (tls_static_space) {
2828 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
2832 tls_last_offset = obj->tlsoffset = off;
2833 tls_last_size = obj->tlssize;
2834 obj->tls_done = true;
2840 free_tls_offset(Obj_Entry *obj)
2842 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) || \
2845 * If we were the last thing to allocate out of the static TLS
2846 * block, we give our space back to the 'allocator'. This is a
2847 * simplistic workaround to allow libGL.so.1 to be loaded and
2848 * unloaded multiple times. We only handle the Variant II
2849 * mechanism for now - this really needs a proper allocator.
2851 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
2852 == calculate_tls_end(tls_last_offset, tls_last_size)) {
2853 tls_last_offset -= obj->tlssize;
2860 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
2865 lockstate = wlock_acquire(rtld_bind_lock);
2866 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign);
2867 wlock_release(rtld_bind_lock, lockstate);
2872 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
2876 lockstate = wlock_acquire(rtld_bind_lock);
2877 free_tls(tcb, tcbsize, tcbalign);
2878 wlock_release(rtld_bind_lock, lockstate);