ldso/libdl/libdl.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Program to load an ELF binary on a linux system, and run it
   4  * after resolving ELF shared library symbols
   5  *
   6  * Copyright (C) 2000-2004 by Erik Andersen <andersen@codepoet.org>
   7  * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
   8  *                              David Engel, Hongjiu Lu and Mitch D'Souza
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. The name of the above contributors may not be
  16  *    used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32
  33 #define _GNU_SOURCE
  34 #include <ldso.h>
  35 #include <stdio.h>
  36
  37
  38 #if defined (__LIBDL_SHARED__)
  39
  40 /* When libdl is loaded as a shared library, we need to load in
  41  * and use a pile of symbols from ldso... */
  42
  43 extern char *_dl_find_hash(const char *, struct dyn_elf *, struct elf_resolve *, int)
  44         __attribute__ ((__weak__));
  45 extern struct elf_resolve * _dl_load_shared_library(int, struct dyn_elf **,
  46         struct elf_resolve *, char *, int) __attribute__ ((__weak__));
  47 extern int _dl_fixup(struct dyn_elf *rpnt, int lazy)
  48          __attribute__ ((__weak__));
  49 extern void _dl_protect_relro(struct elf_resolve * tpnt)
  50         __attribute__ ((__weak__));
  51 extern int _dl_errno __attribute__ ((__weak__));
  52 extern struct dyn_elf *_dl_symbol_tables __attribute__ ((__weak__));
  53 extern struct dyn_elf *_dl_handles __attribute__ ((__weak__));
  54 extern struct elf_resolve *_dl_loaded_modules __attribute__ ((__weak__));
  55 extern struct r_debug *_dl_debug_addr __attribute__ ((__weak__));
  56 extern unsigned long _dl_error_number __attribute__ ((__weak__));
  57 extern void *(*_dl_malloc_function)(size_t) __attribute__ ((__weak__));
  58 #ifdef __LDSO_CACHE_SUPPORT__
  59 int _dl_map_cache(void) __attribute__ ((__weak__));
  60 int _dl_unmap_cache(void) __attribute__ ((__weak__));
  61 #endif
  62 #ifdef __mips__
  63 extern void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy)
  64         __attribute__ ((__weak__));
  65 #endif
  66 #ifdef __SUPPORT_LD_DEBUG__
  67 extern char *_dl_debug __attribute__ ((__weak__));
  68 #endif
  69
  70
  71 #else /* __LIBDL_SHARED__ */
  72
  73 /* When libdl is linked as a static library, we need to replace all
  74  * the symbols that otherwise would have been loaded in from ldso... */
  75
  76 #ifdef __SUPPORT_LD_DEBUG__
  77 char *_dl_debug  = 0;
  78 #endif
  79 char *_dl_library_path         = 0;                 /* Where we look for libraries */
  80 char *_dl_ldsopath             = 0;                 /* Location of the shared lib loader */
  81 int _dl_errno                  = 0;         /* We can't use the real errno in ldso */
  82 size_t _dl_pagesize            = PAGE_SIZE; /* Store the page size for use later */
  83 /* This global variable is also to communicate with debuggers such as gdb. */
  84 struct r_debug *_dl_debug_addr = NULL;
  85 #define _dl_malloc malloc
  86 #include "dl-progname.h"
  87 #include "../ldso/dl-hash.c"
  88 #define _dl_trace_loaded_objects    0
  89 #include "../ldso/dl-elf.c"
  90 #endif /* __LIBDL_SHARED__ */
  91
  92 #ifdef __SUPPORT_LD_DEBUG__
  93 # define _dl_if_debug_print(fmt, args...) \
  94         do { \
  95         if (_dl_debug) \
  96                 fprintf(stderr, "%s():%i: " fmt, __FUNCTION__, __LINE__, ## args); \
  97         } while (0)
  98 #else
  99 # define _dl_if_debug_print(fmt, args...)
 100 #endif
 101
 102 static int do_dlclose(void *, int need_fini);
 103
 104
 105 static const char *dl_error_names[] = {
 106         "",
 107         "File not found",
 108         "Unable to open /dev/zero",
 109         "Not an ELF file",
 110 #if defined (__i386__)
 111         "Not i386 binary",
 112 #elif defined (__sparc__)
 113         "Not sparc binary",
 114 #elif defined (__mc68000__)
 115         "Not m68k binary",
 116 #else
 117         "Unrecognized binary type",
 118 #endif
 119         "Not an ELF shared library",
 120         "Unable to mmap file",
 121         "No dynamic section",
 122 #ifdef ELF_USES_RELOCA
 123         "Unable to process REL relocs",
 124 #else
 125         "Unable to process RELA relocs",
 126 #endif
 127         "Bad handle",
 128         "Unable to resolve symbol"
 129 };
 130
 131 void __attribute__ ((destructor)) dl_cleanup(void)
 132 {
 133         struct dyn_elf *d;
 134         for (d = _dl_handles; d; d = d->next_handle) {
 135                 do_dlclose(d, 1);
 136         }
 137 }
 138
 139 void *dlopen(const char *libname, int flag)
 140 {
 141         struct elf_resolve *tpnt, *tfrom;
 142         struct dyn_elf *dyn_chain, *rpnt = NULL, *dyn_ptr, *relro_ptr, *handle;
 143         struct dyn_elf *dpnt;
 144         ElfW(Addr) from;
 145         struct elf_resolve *tpnt1;
 146         void (*dl_brk) (void);
 147         int now_flag;
 148         struct init_fini_list *tmp, *runp, *runp2, *dep_list;
 149         int nlist, i;
 150         struct elf_resolve **init_fini_list;
 151
 152         /* A bit of sanity checking... */
 153         if (!(flag & (RTLD_LAZY|RTLD_NOW))) {
 154                 _dl_error_number = LD_BAD_HANDLE;
 155                 return NULL;
 156         }
 157
 158         from = (ElfW(Addr)) __builtin_return_address(0);
 159
 160         /* Cover the trivial case first */
 161         if (!libname)
 162                 return _dl_symbol_tables;
 163
 164         _dl_map_cache();
 165
 166         /*
 167          * Try and locate the module we were called from - we
 168          * need this so that we get the correct RPATH/RUNPATH.  Note that
 169          * this is the current behavior under Solaris, but the
 170          * ABI+ specifies that we should only use the RPATH from
 171          * the application.  Thus this may go away at some time
 172          * in the future.
 173          */
 174         tfrom = NULL;
 175         for (dpnt = _dl_symbol_tables; dpnt; dpnt = dpnt->next) {
 176                 tpnt = dpnt->dyn;
 177                 if (tpnt->loadaddr < from
 178                                 && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr))
 179                         tfrom = tpnt;
 180         }
 181         for(rpnt = _dl_symbol_tables; rpnt->next; rpnt=rpnt->next);
 182
 183         relro_ptr = rpnt;
 184         now_flag = (flag & RTLD_NOW) ? RTLD_NOW : 0;
 185         if (getenv("LD_BIND_NOW"))
 186                 now_flag = RTLD_NOW;
 187
 188         /* Try to load the specified library */
 189         _dl_if_debug_print("Trying to dlopen '%s', RTLD_GLOBAL:%d RTLD_NOW:%d\n",
 190                         (char*)libname, (flag & RTLD_GLOBAL ? 1:0), (now_flag & RTLD_NOW ? 1:0));
 191         tpnt = _dl_load_shared_library(0, &rpnt, tfrom, (char*)libname, 0);
 192
 193         if (tpnt == NULL) {
 194                 _dl_unmap_cache();
 195                 return NULL;
 196         }
 197         dyn_chain = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 198         _dl_memset(dyn_chain, 0, sizeof(struct dyn_elf));
 199         dyn_chain->dyn = tpnt;
 200         tpnt->rtld_flags |= (flag & RTLD_GLOBAL);
 201
 202         dyn_chain->next_handle = _dl_handles;
 203         _dl_handles = dyn_ptr = dyn_chain;
 204
 205         if (tpnt->usage_count > 1) {
 206                 _dl_if_debug_print("Lib: %s already opened\n", libname);
 207                 /* see if there is a handle from a earlier dlopen */
 208                 for (handle = _dl_handles->next_handle; handle; handle = handle->next_handle) {
 209                         if (handle->dyn == tpnt) {
 210                                 dyn_chain->init_fini.init_fini = handle->init_fini.init_fini;
 211                                 dyn_chain->init_fini.nlist = handle->init_fini.nlist;
 212                                 for(i=0; i < dyn_chain->init_fini.nlist; i++)
 213                                         dyn_chain->init_fini.init_fini[i]->rtld_flags |= (flag & RTLD_GLOBAL);
 214                                 dyn_chain->next = handle->next;
 215                                 break;
 216                         }
 217                 }
 218                 return dyn_chain;
 219         } else {
 220                 tpnt->init_flag |= DL_OPENED;
 221         }
 222
 223         _dl_if_debug_print("Looking for needed libraries\n");
 224         nlist = 0;
 225         runp = alloca(sizeof(*runp));
 226         runp->tpnt = tpnt;
 227         runp->next = NULL;
 228         dep_list = runp2 = runp;
 229         for (; runp; runp = runp->next)
 230         {
 231                 Elf32_Dyn *dpnt;
 232                 char *lpntstr;
 233
 234                 nlist++;
 235                 runp->tpnt->init_fini = NULL; /* clear any previous dependcies */
 236                 for (dpnt = (Elf32_Dyn *) runp->tpnt->dynamic_addr; dpnt->d_tag; dpnt++) {
 237                         if (dpnt->d_tag == DT_NEEDED) {
 238                                 char *name;
 239
 240                                 lpntstr = (char*) (runp->tpnt->dynamic_info[DT_STRTAB] +
 241                                                 dpnt->d_un.d_val);
 242                                 name = _dl_get_last_path_component(lpntstr);
 243                                 _dl_if_debug_print("Trying to load '%s', needed by '%s'\n",
 244                                                 lpntstr, runp->tpnt->libname);
 245                                 tpnt1 = _dl_load_shared_library(0, &rpnt, runp->tpnt, lpntstr, 0);
 246                                 if (!tpnt1)
 247                                         goto oops;
 248
 249                                 tpnt1->rtld_flags |= (flag & RTLD_GLOBAL);
 250
 251                                 if (tpnt1->usage_count == 1) {
 252                                         tpnt1->init_flag |= DL_OPENED;
 253                                         /* This list is for dlsym() and relocation */
 254                                         dyn_ptr->next = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 255                                         _dl_memset (dyn_ptr->next, 0, sizeof (struct dyn_elf));
 256                                         dyn_ptr = dyn_ptr->next;
 257                                         dyn_ptr->dyn = tpnt1;
 258                                 }
 259                                 if (tpnt1->init_flag & DL_OPENED) {
 260                                         /* Used to record RTLD_LOCAL scope */
 261                                         tmp = alloca(sizeof(struct init_fini_list));
 262                                         tmp->tpnt = tpnt1;
 263                                         tmp->next = runp->tpnt->init_fini;
 264                                         runp->tpnt->init_fini = tmp;
 265
 266                                         for (tmp=dep_list; tmp; tmp = tmp->next) {
 267                                                 if (tpnt1 == tmp->tpnt) { /* if match => cirular dependency, drop it */
 268                                                         _dl_if_debug_print("Circular dependency, skipping '%s',\n",
 269                                                                         tmp->tpnt->libname);
 270                                                         tpnt1->usage_count--;
 271                                                         break;
 272                                                 }
 273                                         }
 274                                         if (!tmp) { /* Don't add if circular dependency detected */
 275                                                 runp2->next = alloca(sizeof(*runp));
 276                                                 runp2 = runp2->next;
 277                                                 runp2->tpnt = tpnt1;
 278                                                 runp2->next = NULL;
 279                                         }
 280                                 }
 281                         }
 282                 }
 283         }
 284         init_fini_list = malloc(nlist * sizeof(struct elf_resolve *));
 285         dyn_chain->init_fini.init_fini = init_fini_list;
 286         dyn_chain->init_fini.nlist = nlist;
 287         i = 0;
 288         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 289                 init_fini_list[i++] = runp2->tpnt;
 290                 for(runp = runp2->tpnt->init_fini; runp; runp = runp->next){
 291                         if (!(runp->tpnt->rtld_flags & RTLD_GLOBAL)) {
 292                                 tmp = malloc(sizeof(struct init_fini_list));
 293                                 tmp->tpnt = runp->tpnt;
 294                                 tmp->next = runp2->tpnt->rtld_local;
 295                                 runp2->tpnt->rtld_local = tmp;
 296                         }
 297                 }
 298
 299         }
 300         /* Sort the INIT/FINI list in dependency order. */
 301         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 302                 int j, k;
 303                 for (j = 0; init_fini_list[j] != runp2->tpnt; ++j)
 304                         /* Empty */;
 305                 for (k = j + 1; k < nlist; ++k) {
 306                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 307
 308                         for (; runp; runp = runp->next) {
 309                                 if (runp->tpnt == runp2->tpnt) {
 310                                         struct elf_resolve *here = init_fini_list[k];
 311                                         _dl_if_debug_print("Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
 312                                         for (i = (k - j); i; --i)
 313                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 314                                         init_fini_list[j] = here;
 315                                         ++j;
 316                                         break;
 317                                 }
 318                         }
 319                 }
 320         }
 321 #ifdef __SUPPORT_LD_DEBUG__
 322         if(_dl_debug) {
 323                 fprintf(stderr, "\nINIT/FINI order and dependencies:\n");
 324                 for (i=0;i < nlist;i++) {
 325                         fprintf(stderr, "lib: %s has deps:\n", init_fini_list[i]->libname);
 326                         runp = init_fini_list[i]->init_fini;
 327                         for (; runp; runp = runp->next)
 328                                 printf(" %s ", runp->tpnt->libname);
 329                         printf("\n");
 330                 }
 331         }
 332 #endif
 333
 334         _dl_if_debug_print("Beginning dlopen relocation fixups\n");
 335         /*
 336          * OK, now all of the kids are tucked into bed in their proper addresses.
 337          * Now we go through and look for REL and RELA records that indicate fixups
 338          * to the GOT tables.  We need to do this in reverse order so that COPY
 339          * directives work correctly */
 340 #ifdef __mips__
 341         /*
 342          * Relocation of the GOT entries for MIPS have to be done
 343          * after all the libraries have been loaded.
 344          */
 345         _dl_perform_mips_global_got_relocations(tpnt, !now_flag);
 346 #endif
 347
 348         if (_dl_fixup(dyn_chain, now_flag))
 349                 goto oops;
 350
 351         for (rpnt = relro_ptr->next; rpnt; rpnt = rpnt->next) {
 352                 if (rpnt->dyn->relro_size)
 353                         _dl_protect_relro(rpnt->dyn);
 354         }
 355         /* TODO:  Should we set the protections of all pages back to R/O now ? */
 356
 357
 358         /* Notify the debugger we have added some objects. */
 359         if (_dl_debug_addr) {
 360                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 361                 if (dl_brk != NULL) {
 362                         _dl_debug_addr->r_state = RT_ADD;
 363                         (*dl_brk) ();
 364
 365                         _dl_debug_addr->r_state = RT_CONSISTENT;
 366                         (*dl_brk) ();
 367                 }
 368         }
 369
 370 #if defined (__LIBDL_SHARED__)
 371         /* Run the ctors and setup the dtors */
 372         for (i = nlist; i; --i) {
 373                 tpnt = init_fini_list[i-1];
 374                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 375                         continue;
 376                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 377
 378                 if (tpnt->dynamic_info[DT_INIT]) {
 379                         void (*dl_elf_func) (void);
 380                         dl_elf_func = (void (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 381                         if (dl_elf_func && *dl_elf_func != NULL) {
 382                                 _dl_if_debug_print("running ctors for library %s at '%x'\n",
 383                                                 tpnt->libname, (unsigned)dl_elf_func);
 384                                 (*dl_elf_func) ();
 385                         }
 386                 }
 387         }
 388 #endif
 389         _dl_unmap_cache();
 390         return (void *) dyn_chain;
 391
 392 oops:
 393         /* Something went wrong.  Clean up and return NULL. */
 394         _dl_unmap_cache();
 395         do_dlclose(dyn_chain, 0);
 396         return NULL;
 397 }
 398
 399 void *dlsym(void *vhandle, const char *name)
 400 {
 401         struct elf_resolve *tpnt, *tfrom;
 402         struct dyn_elf *handle;
 403         ElfW(Addr) from;
 404         struct dyn_elf *rpnt;
 405         void *ret;
 406
 407         handle = (struct dyn_elf *) vhandle;
 408
 409         /* First of all verify that we have a real handle
 410            of some kind.  Return NULL if not a valid handle. */
 411
 412         if (handle == NULL)
 413                 handle = _dl_symbol_tables;
 414         else if (handle != RTLD_NEXT && handle != _dl_symbol_tables) {
 415                 for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle)
 416                         if (rpnt == handle)
 417                                 break;
 418                 if (!rpnt) {
 419                         _dl_error_number = LD_BAD_HANDLE;
 420                         return NULL;
 421                 }
 422         } else if (handle == RTLD_NEXT) {
 423                 /*
 424                  * Try and locate the module we were called from - we
 425                  * need this so that we know where to start searching
 426                  * from.  We never pass RTLD_NEXT down into the actual
 427                  * dynamic loader itself, as it doesn't know
 428                  * how to properly treat it.
 429                  */
 430                 from = (ElfW(Addr)) __builtin_return_address(0);
 431
 432                 tfrom = NULL;
 433                 for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next) {
 434                         tpnt = rpnt->dyn;
 435                         if (tpnt->loadaddr < from
 436                                         && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr)) {
 437                                 tfrom = tpnt;
 438                                 handle = rpnt->next;
 439                         }
 440                 }
 441         }
 442
 443         ret = _dl_find_hash((char*)name, handle, NULL, 0);
 444
 445         /*
 446          * Nothing found.
 447          */
 448         if (!ret)
 449                 _dl_error_number = LD_NO_SYMBOL;
 450         return ret;
 451 }
 452
 453 static int do_dlclose(void *vhandle, int need_fini)
 454 {
 455         struct dyn_elf *rpnt, *rpnt1;
 456         struct init_fini_list *runp, *tmp;
 457         ElfW(Phdr) *ppnt;
 458         struct elf_resolve *tpnt, *run_tpnt;
 459         int (*dl_elf_fini) (void);
 460         void (*dl_brk) (void);
 461         struct dyn_elf *handle;
 462         unsigned int end;
 463         int i = 0, j;
 464
 465         handle = (struct dyn_elf *) vhandle;
 466         if (handle == _dl_symbol_tables)
 467                 return 0;
 468         rpnt1 = NULL;
 469         for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle) {
 470                 if (rpnt == handle)
 471                         break;
 472                 rpnt1 = rpnt;
 473         }
 474
 475         if (!rpnt) {
 476                 _dl_error_number = LD_BAD_HANDLE;
 477                 return 1;
 478         }
 479         if (rpnt1)
 480                 rpnt1->next_handle = rpnt->next_handle;
 481         else
 482                 _dl_handles = rpnt->next_handle;
 483         _dl_if_debug_print("%s: usage count: %d\n",
 484                         handle->dyn->libname, handle->dyn->usage_count);
 485         if (handle->dyn->usage_count != 1) {
 486                 handle->dyn->usage_count--;
 487                 free(handle);
 488                 return 0;
 489         }
 490         /* OK, this is a valid handle - now close out the file */
 491         for (j = 0; j < handle->init_fini.nlist; ++j) {
 492                 tpnt = handle->init_fini.init_fini[j];
 493                 if (--tpnt->usage_count == 0) {
 494                         if (tpnt->dynamic_info[DT_FINI] && need_fini &&
 495                             !(tpnt->init_flag & FINI_FUNCS_CALLED)) {
 496                                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 497                                 dl_elf_fini = (int (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 498                                 _dl_if_debug_print("running dtors for library %s at '%x'\n",
 499                                                 tpnt->libname, (unsigned)dl_elf_fini);
 500                                 (*dl_elf_fini) ();
 501                         }
 502
 503                         _dl_if_debug_print("unmapping: %s\n", tpnt->libname);
 504                         end = 0;
 505                         for (i = 0, ppnt = tpnt->ppnt;
 506                                         i < tpnt->n_phent; ppnt++, i++) {
 507                                 if (ppnt->p_type != PT_LOAD)
 508                                         continue;
 509                                 if (end < ppnt->p_vaddr + ppnt->p_memsz)
 510                                         end = ppnt->p_vaddr + ppnt->p_memsz;
 511                         }
 512                         _dl_munmap((void*)tpnt->loadaddr, end);
 513                         /* Free elements in RTLD_LOCAL scope list */
 514                         for (runp = tpnt->rtld_local; runp; runp = tmp) {
 515                                 tmp = runp->next;
 516                                 free(runp);
 517                         }
 518
 519                         /* Next, remove tpnt from the loaded_module list */
 520                         if (_dl_loaded_modules == tpnt) {
 521                                 _dl_loaded_modules = tpnt->next;
 522                                 if (_dl_loaded_modules)
 523                                         _dl_loaded_modules->prev = 0;
 524                         } else
 525                                 for (run_tpnt = _dl_loaded_modules; run_tpnt; run_tpnt = run_tpnt->next)
 526                                         if (run_tpnt->next == tpnt) {
 527                                                 _dl_if_debug_print("removing loaded_modules: %s\n", tpnt->libname);
 528                                                 run_tpnt->next = run_tpnt->next->next;
 529                                                 if (run_tpnt->next)
 530                                                         run_tpnt->next->prev = run_tpnt;
 531                                                 break;
 532                                         }
 533
 534                         /* Next, remove tpnt from the global symbol table list */
 535                         if (_dl_symbol_tables->dyn == tpnt) {
 536                                 _dl_symbol_tables = _dl_symbol_tables->next;
 537                                 if (_dl_symbol_tables)
 538                                         _dl_symbol_tables->prev = 0;
 539                         } else
 540                                 for (rpnt1 = _dl_symbol_tables; rpnt1->next; rpnt1 = rpnt1->next) {
 541                                         if (rpnt1->next->dyn == tpnt) {
 542                                                 _dl_if_debug_print("removing symbol_tables: %s\n", tpnt->libname);
 543                                                 free(rpnt1->next);
 544                                                 rpnt1->next = rpnt1->next->next;
 545                                                 if (rpnt1->next)
 546                                                         rpnt1->next->prev = rpnt1;
 547                                                 break;
 548                                         }
 549                                 }
 550                         free(tpnt->libname);
 551                         free(tpnt);
 552                 }
 553         }
 554         free(handle->init_fini.init_fini);
 555         free(handle);
 556
 557
 558         if (_dl_debug_addr) {
 559                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 560                 if (dl_brk != NULL) {
 561                         _dl_debug_addr->r_state = RT_DELETE;
 562                         (*dl_brk) ();
 563
 564                         _dl_debug_addr->r_state = RT_CONSISTENT;
 565                         (*dl_brk) ();
 566                 }
 567         }
 568
 569         return 0;
 570 }
 571
 572 int dlclose(void *vhandle)
 573 {
 574         return do_dlclose(vhandle, 1);
 575 }
 576
 577 char *dlerror(void)
 578 {
 579         const char *retval;
 580
 581         if (!_dl_error_number)
 582                 return NULL;
 583         retval = dl_error_names[_dl_error_number];
 584         _dl_error_number = 0;
 585         return (char *)retval;
 586 }
 587
 588 /*
 589  * Dump information to stderrr about the current loaded modules
 590  */
 591 static char *type[] = { "Lib", "Exe", "Int", "Mod" };
 592
 593 int dlinfo(void)
 594 {
 595         struct elf_resolve *tpnt;
 596         struct dyn_elf *rpnt, *hpnt;
 597
 598         fprintf(stderr, "List of loaded modules\n");
 599         /* First start with a complete list of all of the loaded files. */
 600         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 601                 fprintf(stderr, "\t%x %x %x %s %d %s\n",
 602                                 (unsigned) tpnt->loadaddr, (unsigned) tpnt,
 603                                 (unsigned) tpnt->symbol_scope,
 604                                 type[tpnt->libtype],
 605                                 tpnt->usage_count, tpnt->libname);
 606         }
 607
 608         /* Next dump the module list for the application itself */
 609         fprintf(stderr, "\nModules for application (%x):\n",
 610                         (unsigned) _dl_symbol_tables);
 611         for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next)
 612                 fprintf(stderr, "\t%x %s\n", (unsigned) rpnt->dyn, rpnt->dyn->libname);
 613
 614         for (hpnt = _dl_handles; hpnt; hpnt = hpnt->next_handle) {
 615                 fprintf(stderr, "Modules for handle %x\n", (unsigned) hpnt);
 616                 for (rpnt = hpnt; rpnt; rpnt = rpnt->next)
 617                         fprintf(stderr, "\t%x %s\n", (unsigned) rpnt->dyn,
 618                                         rpnt->dyn->libname);
 619         }
 620         return 0;
 621 }
 622
 623 int dladdr(const void *__address, Dl_info * __info)
 624 {
 625         struct elf_resolve *pelf;
 626         struct elf_resolve *rpnt;
 627
 628         _dl_map_cache();
 629
 630         /*
 631          * Try and locate the module address is in
 632          */
 633         pelf = NULL;
 634
 635 #if 0
 636         fprintf(stderr, "dladdr( %x, %x )\n", __address, __info);
 637 #endif
 638
 639         for (rpnt = _dl_loaded_modules; rpnt; rpnt = rpnt->next) {
 640                 struct elf_resolve *tpnt;
 641
 642                 tpnt = rpnt;
 643 #if 0
 644                 fprintf(stderr, "Module \"%s\" at %x\n",
 645                                 tpnt->libname, tpnt->loadaddr);
 646 #endif
 647                 if (tpnt->loadaddr < (ElfW(Addr)) __address
 648                                 && (pelf == NULL || pelf->loadaddr < tpnt->loadaddr)) {
 649                         pelf = tpnt;
 650                 }
 651         }
 652
 653         if (!pelf) {
 654                 return 0;
 655         }
 656
 657         /*
 658          * Try and locate the symbol of address
 659          */
 660
 661         {
 662                 char *strtab;
 663                 Elf32_Sym *symtab;
 664                 int hn, si;
 665                 int sf;
 666                 int sn = 0;
 667                 ElfW(Addr) sa;
 668
 669                 sa = 0;
 670                 symtab = (Elf32_Sym *) (pelf->dynamic_info[DT_SYMTAB]);
 671                 strtab = (char *) (pelf->dynamic_info[DT_STRTAB]);
 672
 673                 sf = 0;
 674                 for (hn = 0; hn < pelf->nbucket; hn++) {
 675                         for (si = pelf->elf_buckets[hn]; si; si = pelf->chains[si]) {
 676                                 ElfW(Addr) symbol_addr;
 677
 678                                 symbol_addr = pelf->loadaddr + symtab[si].st_value;
 679                                 if (symbol_addr <= (ElfW(Addr))__address && (!sf || sa < symbol_addr)) {
 680                                         sa = symbol_addr;
 681                                         sn = si;
 682                                         sf = 1;
 683                                 }
 684 #if 0
 685                                 fprintf(stderr, "Symbol \"%s\" at %x\n",
 686                                                 strtab + symtab[si].st_name, symbol_addr);
 687 #endif
 688                         }
 689                 }
 690
 691                 if (sf) {
 692                         __info->dli_fname = pelf->libname;
 693                         __info->dli_fbase = (void *)pelf->loadaddr;
 694                         __info->dli_sname = strtab + symtab[sn].st_name;
 695                         __info->dli_saddr = (void *)sa;
 696                 }
 697                 return 1;
 698         }
 699 }