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 struct elf_resolve * _dl_check_if_named_library_is_loaded(const char *, int)
  48         __attribute__ ((__weak__));
  49 extern int _dl_fixup(struct dyn_elf *rpnt, int lazy)
  50          __attribute__ ((__weak__));
  51 extern void _dl_protect_relro(struct elf_resolve * tpnt)
  52         __attribute__ ((__weak__));
  53 extern int _dl_errno __attribute__ ((__weak__));
  54 extern struct dyn_elf *_dl_symbol_tables __attribute__ ((__weak__));
  55 extern struct dyn_elf *_dl_handles __attribute__ ((__weak__));
  56 extern struct elf_resolve *_dl_loaded_modules __attribute__ ((__weak__));
  57 extern struct r_debug *_dl_debug_addr __attribute__ ((__weak__));
  58 extern unsigned long _dl_error_number __attribute__ ((__weak__));
  59 extern void *(*_dl_malloc_function)(size_t) __attribute__ ((__weak__));
  60 #ifdef __LDSO_CACHE_SUPPORT__
  61 int _dl_map_cache(void) __attribute__ ((__weak__));
  62 int _dl_unmap_cache(void) __attribute__ ((__weak__));
  63 #endif
  64 #ifdef __mips__
  65 extern void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy)
  66         __attribute__ ((__weak__));
  67 #endif
  68 #ifdef __SUPPORT_LD_DEBUG__
  69 extern char *_dl_debug __attribute__ ((__weak__));
  70 #endif
  71
  72
  73 #else /* __LIBDL_SHARED__ */
  74
  75 /* When libdl is linked as a static library, we need to replace all
  76  * the symbols that otherwise would have been loaded in from ldso... */
  77
  78 #ifdef __SUPPORT_LD_DEBUG__
  79 char *_dl_debug  = 0;
  80 #endif
  81 char *_dl_library_path         = 0;                 /* Where we look for libraries */
  82 char *_dl_ldsopath             = 0;                 /* Location of the shared lib loader */
  83 int _dl_errno                  = 0;         /* We can't use the real errno in ldso */
  84 size_t _dl_pagesize            = PAGE_SIZE; /* Store the page size for use later */
  85 /* This global variable is also to communicate with debuggers such as gdb. */
  86 struct r_debug *_dl_debug_addr = NULL;
  87 #define _dl_malloc malloc
  88 #include "dl-progname.h"
  89 #include "../ldso/dl-hash.c"
  90 #define _dl_trace_loaded_objects    0
  91 #include "../ldso/dl-elf.c"
  92 #endif
  93
  94 static int do_dlclose(void *, int need_fini);
  95
  96
  97 static const char *dl_error_names[] = {
  98         "",
  99         "File not found",
 100         "Unable to open /dev/zero",
 101         "Not an ELF file",
 102 #if defined (__i386__)
 103         "Not i386 binary",
 104 #elif defined (__sparc__)
 105         "Not sparc binary",
 106 #elif defined (__mc68000__)
 107         "Not m68k binary",
 108 #else
 109         "Unrecognized binary type",
 110 #endif
 111         "Not an ELF shared library",
 112         "Unable to mmap file",
 113         "No dynamic section",
 114 #ifdef ELF_USES_RELOCA
 115         "Unable to process REL relocs",
 116 #else
 117         "Unable to process RELA relocs",
 118 #endif
 119         "Bad handle",
 120         "Unable to resolve symbol"
 121 };
 122
 123 void __attribute__ ((destructor)) dl_cleanup(void)
 124 {
 125         struct dyn_elf *d;
 126         for (d = _dl_handles; d; d = d->next_handle) {
 127                 do_dlclose(d, 1);
 128         }
 129 }
 130
 131 void *dlopen(const char *libname, int flag)
 132 {
 133         struct elf_resolve *tpnt, *tfrom, *tcurr=NULL;
 134         struct dyn_elf *dyn_chain, *rpnt = NULL, *dyn_ptr, *relro_ptr, *handle;
 135         struct dyn_elf *dpnt;
 136         ElfW(Addr) from;
 137         struct elf_resolve *tpnt1;
 138         void (*dl_brk) (void);
 139         int now_flag;
 140         struct init_fini_list *tmp, *runp, *runp2, *dep_list;
 141         int nlist, i;
 142         struct elf_resolve **init_fini_list;
 143
 144         /* A bit of sanity checking... */
 145         if (!(flag & (RTLD_LAZY|RTLD_NOW))) {
 146                 _dl_error_number = LD_BAD_HANDLE;
 147                 return NULL;
 148         }
 149
 150         from = (ElfW(Addr)) __builtin_return_address(0);
 151
 152         /* Cover the trivial case first */
 153         if (!libname)
 154                 return _dl_symbol_tables;
 155
 156         _dl_map_cache();
 157
 158         /*
 159          * Try and locate the module we were called from - we
 160          * need this so that we get the correct RPATH.  Note that
 161          * this is the current behavior under Solaris, but the
 162          * ABI+ specifies that we should only use the RPATH from
 163          * the application.  Thus this may go away at some time
 164          * in the future.
 165          */
 166         tfrom = NULL;
 167         for (dpnt = _dl_symbol_tables; dpnt; dpnt = dpnt->next) {
 168                 tpnt = dpnt->dyn;
 169                 if (tpnt->loadaddr < from
 170                                 && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr))
 171                         tfrom = tpnt;
 172         }
 173         for(rpnt = _dl_symbol_tables; rpnt->next; rpnt=rpnt->next);
 174
 175         relro_ptr = rpnt;
 176         /* Try to load the specified library */
 177 #ifdef __SUPPORT_LD_DEBUG__
 178         if(_dl_debug)
 179                 fprintf(stderr, "Trying to dlopen '%s'\n", (char*)libname);
 180 #endif
 181         tpnt = _dl_check_if_named_library_is_loaded((char *)libname, 0);
 182         if (!(tpnt))
 183                 tpnt = _dl_load_shared_library(0, &rpnt, tfrom, (char*)libname, 0);
 184         else
 185                 tpnt->usage_count++;
 186         if (tpnt == NULL) {
 187                 _dl_unmap_cache();
 188                 return NULL;
 189         }
 190         dyn_chain = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 191         _dl_memset(dyn_chain, 0, sizeof(struct dyn_elf));
 192         dyn_chain->dyn = tpnt;
 193         tpnt->rtld_flags |= (flag & RTLD_GLOBAL);
 194
 195         dyn_chain->next_handle = _dl_handles;
 196         _dl_handles = dyn_ptr = dyn_chain;
 197
 198         if (tpnt->usage_count > 1) {
 199 #ifdef __SUPPORT_LD_DEBUG__
 200                 if(_dl_debug)
 201                         fprintf(stderr, "Lib: % already opened\n", libname);
 202 #endif
 203                 /* see if there is a handle from a earlier dlopen */
 204                 for (handle = _dl_handles->next_handle; handle; handle = handle->next_handle) {
 205                         if (handle->dyn == tpnt) {
 206                                 dyn_chain->init_fini.init_fini = handle->init_fini.init_fini;
 207                                 dyn_chain->init_fini.nlist = handle->init_fini.nlist;
 208                                 for(i=0; i < dyn_chain->init_fini.nlist; i++)
 209                                         dyn_chain->init_fini.init_fini[i]->rtld_flags |= (flag & RTLD_GLOBAL);
 210                                 dyn_chain->next = handle->next;
 211                                 break;
 212                         }
 213                 }
 214                 return dyn_chain;
 215         } else {
 216                 tpnt->init_flag |= DL_OPENED;
 217         }
 218
 219 #ifdef __SUPPORT_LD_DEBUG__
 220         if(_dl_debug)
 221                 fprintf(stderr, "Looking for needed libraries\n");
 222 #endif
 223         nlist = 0;
 224         runp = alloca(sizeof(*runp));
 225         runp->tpnt = tpnt;
 226         runp->next = NULL;
 227         dep_list = runp2 = runp;
 228         for (; runp; runp = runp->next)
 229         {
 230                 Elf32_Dyn *dpnt;
 231                 char *lpntstr;
 232
 233                 nlist++;
 234                 runp->tpnt->init_fini = NULL; /* clear any previous dependcies */
 235                 for (dpnt = (Elf32_Dyn *) runp->tpnt->dynamic_addr; dpnt->d_tag; dpnt++) {
 236                         if (dpnt->d_tag == DT_NEEDED) {
 237                                 char *name;
 238
 239                                 lpntstr = (char*) (runp->tpnt->dynamic_info[DT_STRTAB] +
 240                                                 dpnt->d_un.d_val);
 241                                 name = _dl_get_last_path_component(lpntstr);
 242                                 tpnt1 = _dl_check_if_named_library_is_loaded(name, 0);
 243 #ifdef __SUPPORT_LD_DEBUG__
 244                                 if(_dl_debug)
 245                                         fprintf(stderr, "Trying to load '%s', needed by '%s'\n",
 246                                                         lpntstr, runp->tpnt->libname);
 247 #endif
 248                                 if (tpnt1) {
 249                                         tpnt1->usage_count++;
 250                                 } else {
 251                                         tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, 0);
 252                                         if (!tpnt1)
 253                                                 goto oops;
 254                                         tpnt1->init_flag |= DL_OPENED;
 255
 256                                 }
 257                                 tpnt1->rtld_flags |= (flag & RTLD_GLOBAL);
 258
 259                                 if (tpnt1->usage_count == 1) {
 260                                         /* This list is for dlsym() and relocation */
 261                                         dyn_ptr->next = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 262                                         _dl_memset (dyn_ptr->next, 0, sizeof (struct dyn_elf));
 263                                         dyn_ptr = dyn_ptr->next;
 264                                         dyn_ptr->dyn = tpnt1;
 265                                 }
 266                                 if (tpnt1->init_flag & DL_OPENED) {
 267                                         /* Used to record RTLD_LOCAL scope */
 268                                         tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
 269                                         tmp->tpnt = tpnt1;
 270                                         tmp->next = runp->tpnt->init_fini;
 271                                         runp->tpnt->init_fini = tmp;
 272
 273                                         runp2->next = alloca(sizeof(*runp)); /* Allocates on stack, no need to free this memory */
 274                                         runp2 = runp2->next;
 275                                         runp2->tpnt = tpnt1;
 276                                         runp2->next = NULL;
 277                                 }
 278                         }
 279                 }
 280         }
 281         init_fini_list = malloc(nlist * sizeof(struct elf_resolve *));
 282         dyn_chain->init_fini.init_fini = init_fini_list;
 283         dyn_chain->init_fini.nlist = nlist;
 284         i = 0;
 285         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 286                 init_fini_list[i++] = runp2->tpnt;
 287                 for(runp = runp2->tpnt->init_fini; runp; runp = runp->next){
 288                         if (!(runp->tpnt->rtld_flags & RTLD_GLOBAL)) {
 289                                 tmp = malloc(sizeof(struct init_fini_list));
 290                                 tmp->tpnt = runp->tpnt;
 291                                 tmp->next = runp2->tpnt->rtld_local;
 292                                 runp2->tpnt->rtld_local = tmp;
 293                         }
 294                 }
 295
 296         }
 297         /* Sort the INIT/FINI list in dependency order. */
 298         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 299                 int j, k;
 300                 for (j = 0; init_fini_list[j] != runp2->tpnt; ++j)
 301                         /* Empty */;
 302                 for (k = j + 1; k < nlist; ++k) {
 303                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 304
 305                         for (; runp; runp = runp->next) {
 306                                 if (runp->tpnt == runp2->tpnt) {
 307                                         struct elf_resolve *here = init_fini_list[k];
 308 #ifdef __SUPPORT_LD_DEBUG__
 309                                         if(_dl_debug)
 310                                                 fprintf(stderr, "Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
 311 #endif
 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 #ifdef __SUPPORT_LD_DEBUG__
 335         if(_dl_debug)
 336                 fprintf(stderr, "Beginning dlopen relocation fixups\n");
 337 #endif
 338         /*
 339          * OK, now all of the kids are tucked into bed in their proper addresses.
 340          * Now we go through and look for REL and RELA records that indicate fixups
 341          * to the GOT tables.  We need to do this in reverse order so that COPY
 342          * directives work correctly */
 343         now_flag = (flag & RTLD_NOW) ? RTLD_NOW : 0;
 344         if (getenv("LD_BIND_NOW"))
 345                 now_flag = RTLD_NOW;
 346
 347 #ifdef __mips__
 348         /*
 349          * Relocation of the GOT entries for MIPS have to be done
 350          * after all the libraries have been loaded.
 351          */
 352         _dl_perform_mips_global_got_relocations(tpnt, !now_flag);
 353 #endif
 354
 355         if (_dl_fixup(dyn_chain, now_flag))
 356                 goto oops;
 357
 358         for (rpnt = relro_ptr->next; rpnt; rpnt = rpnt->next) {
 359                 if (rpnt->dyn->relro_size)
 360                         _dl_protect_relro(rpnt->dyn);
 361         }
 362         /* TODO:  Should we set the protections of all pages back to R/O now ? */
 363
 364
 365         /* Notify the debugger we have added some objects. */
 366         if (_dl_debug_addr) {
 367                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 368                 if (dl_brk != NULL) {
 369                         _dl_debug_addr->r_state = RT_ADD;
 370                         (*dl_brk) ();
 371
 372                         _dl_debug_addr->r_state = RT_CONSISTENT;
 373                         (*dl_brk) ();
 374                 }
 375         }
 376
 377 #if defined (__LIBDL_SHARED__)
 378         /* Run the ctors and setup the dtors */
 379         for (i = nlist; i; --i) {
 380                 tpnt = init_fini_list[i-1];
 381                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 382                         continue;
 383                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 384
 385                 if (tpnt->dynamic_info[DT_INIT]) {
 386                         void (*dl_elf_func) (void);
 387                         dl_elf_func = (void (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 388                         if (dl_elf_func && *dl_elf_func != NULL) {
 389 #ifdef __SUPPORT_LD_DEBUG__
 390                                 if(_dl_debug)
 391                                         fprintf(stderr, "running ctors for library %s at '%x'\n", tpnt->libname, (unsigned)dl_elf_func);
 392 #endif
 393                                 (*dl_elf_func) ();
 394                         }
 395                 }
 396         }
 397 #endif
 398         _dl_unmap_cache();
 399         return (void *) dyn_chain;
 400
 401 oops:
 402         /* Something went wrong.  Clean up and return NULL. */
 403         _dl_unmap_cache();
 404         do_dlclose(dyn_chain, 0);
 405         return NULL;
 406 }
 407
 408 void *dlsym(void *vhandle, const char *name)
 409 {
 410         struct elf_resolve *tpnt, *tfrom;
 411         struct dyn_elf *handle;
 412         ElfW(Addr) from;
 413         struct dyn_elf *rpnt;
 414         void *ret;
 415
 416         handle = (struct dyn_elf *) vhandle;
 417
 418         /* First of all verify that we have a real handle
 419            of some kind.  Return NULL if not a valid handle. */
 420
 421         if (handle == NULL)
 422                 handle = _dl_symbol_tables;
 423         else if (handle != RTLD_NEXT && handle != _dl_symbol_tables) {
 424                 for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle)
 425                         if (rpnt == handle)
 426                                 break;
 427                 if (!rpnt) {
 428                         _dl_error_number = LD_BAD_HANDLE;
 429                         return NULL;
 430                 }
 431         } else if (handle == RTLD_NEXT) {
 432                 /*
 433                  * Try and locate the module we were called from - we
 434                  * need this so that we know where to start searching
 435                  * from.  We never pass RTLD_NEXT down into the actual
 436                  * dynamic loader itself, as it doesn't know
 437                  * how to properly treat it.
 438                  */
 439                 from = (ElfW(Addr)) __builtin_return_address(0);
 440
 441                 tfrom = NULL;
 442                 for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next) {
 443                         tpnt = rpnt->dyn;
 444                         if (tpnt->loadaddr < from
 445                                         && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr)) {
 446                                 tfrom = tpnt;
 447                                 handle = rpnt->next;
 448                         }
 449                 }
 450         }
 451
 452         ret = _dl_find_hash((char*)name, handle, NULL, 0);
 453
 454         /*
 455          * Nothing found.
 456          */
 457         if (!ret)
 458                 _dl_error_number = LD_NO_SYMBOL;
 459         return ret;
 460 }
 461
 462 static int do_dlclose(void *vhandle, int need_fini)
 463 {
 464         struct dyn_elf *rpnt, *rpnt1;
 465         struct init_fini_list *runp, *tmp;
 466         ElfW(Phdr) *ppnt;
 467         struct elf_resolve *tpnt, *run_tpnt;
 468         int (*dl_elf_fini) (void);
 469         void (*dl_brk) (void);
 470         struct dyn_elf *handle;
 471         unsigned int end;
 472         int i = 0, j;
 473
 474         handle = (struct dyn_elf *) vhandle;
 475         if (handle == _dl_symbol_tables)
 476                 return 0;
 477         rpnt1 = NULL;
 478         for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle) {
 479                 if (rpnt == handle)
 480                         break;
 481                 rpnt1 = rpnt;
 482         }
 483
 484         if (!rpnt) {
 485                 _dl_error_number = LD_BAD_HANDLE;
 486                 return 1;
 487         }
 488         if (rpnt1)
 489                 rpnt1->next_handle = rpnt->next_handle;
 490         else
 491                 _dl_handles = rpnt->next_handle;
 492 #ifdef __SUPPORT_LD_DEBUG__
 493         if(_dl_debug)
 494                 fprintf(stderr, "dlclose: %s, usage count: %d\n", handle->dyn->libname, handle->dyn->usage_count);
 495 #endif
 496         if (handle->dyn->usage_count != 1) {
 497                 handle->dyn->usage_count--;
 498                 free(handle);
 499                 return 0;
 500         }
 501         /* OK, this is a valid handle - now close out the file */
 502         for (j = 0; j < handle->init_fini.nlist; ++j) {
 503                 tpnt = handle->init_fini.init_fini[j];
 504                 if (--tpnt->usage_count == 0) {
 505                         if (tpnt->dynamic_info[DT_FINI] && need_fini &&
 506                             !(tpnt->init_flag & FINI_FUNCS_CALLED)) {
 507                                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 508                                 dl_elf_fini = (int (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 509 #ifdef __SUPPORT_LD_DEBUG__
 510                                 if(_dl_debug)
 511                                         fprintf(stderr, "running dtors for library %s at '%x'\n", tpnt->libname, (unsigned)dl_elf_fini);
 512 #endif
 513                                 (*dl_elf_fini) ();
 514                         }
 515
 516 #ifdef __SUPPORT_LD_DEBUG__
 517                         if(_dl_debug)
 518                                 fprintf(stderr, "dlclose unmapping: %s\n", tpnt->libname);
 519 #endif
 520                         end = 0;
 521                         for (i = 0, ppnt = tpnt->ppnt;
 522                                         i < tpnt->n_phent; ppnt++, i++) {
 523                                 if (ppnt->p_type != PT_LOAD)
 524                                         continue;
 525                                 if (end < ppnt->p_vaddr + ppnt->p_memsz)
 526                                         end = ppnt->p_vaddr + ppnt->p_memsz;
 527                         }
 528                         _dl_munmap((void*)tpnt->loadaddr, end);
 529                         /* Free elements in RTLD_LOCAL scope list */
 530                         for (runp = tpnt->rtld_local; runp; runp = tmp) {
 531                                 tmp = runp->next;
 532                                 free(runp);
 533                         }
 534
 535                         /* Next, remove tpnt from the loaded_module list */
 536                         if (_dl_loaded_modules == tpnt) {
 537                                 _dl_loaded_modules = tpnt->next;
 538                                 if (_dl_loaded_modules)
 539                                         _dl_loaded_modules->prev = 0;
 540                         } else
 541                                 for (run_tpnt = _dl_loaded_modules; run_tpnt; run_tpnt = run_tpnt->next)
 542                                         if (run_tpnt->next == tpnt) {
 543 #ifdef __SUPPORT_LD_DEBUG__
 544                                                 if(_dl_debug)
 545                                                         fprintf(stderr, "dlclose removing loaded_modules: %s\n", tpnt->libname);
 546 #endif
 547                                                 run_tpnt->next = run_tpnt->next->next;
 548                                                 if (run_tpnt->next)
 549                                                         run_tpnt->next->prev = run_tpnt;
 550                                                 break;
 551                                         }
 552
 553                         /* Next, remove tpnt from the global symbol table list */
 554                         if (_dl_symbol_tables->dyn == tpnt) {
 555                                 _dl_symbol_tables = _dl_symbol_tables->next;
 556                                 if (_dl_symbol_tables)
 557                                         _dl_symbol_tables->prev = 0;
 558                         } else
 559                                 for (rpnt1 = _dl_symbol_tables; rpnt1->next; rpnt1 = rpnt1->next) {
 560                                         if (rpnt1->next->dyn == tpnt) {
 561 #ifdef __SUPPORT_LD_DEBUG__
 562                                                 if(_dl_debug)
 563                                                         fprintf(stderr, "dlclose removing symbol_tables: %s\n", tpnt->libname);
 564 #endif
 565                                                 free(rpnt1->next);
 566                                                 rpnt1->next = rpnt1->next->next;
 567                                                 if (rpnt1->next)
 568                                                         rpnt1->next->prev = rpnt1;
 569                                                 break;
 570                                         }
 571                                 }
 572                         free(tpnt->libname);
 573                         free(tpnt);
 574                 }
 575         }
 576         free(handle->init_fini.init_fini);
 577         free(handle);
 578
 579
 580         if (_dl_debug_addr) {
 581                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 582                 if (dl_brk != NULL) {
 583                         _dl_debug_addr->r_state = RT_DELETE;
 584                         (*dl_brk) ();
 585
 586                         _dl_debug_addr->r_state = RT_CONSISTENT;
 587                         (*dl_brk) ();
 588                 }
 589         }
 590
 591         return 0;
 592 }
 593
 594 int dlclose(void *vhandle)
 595 {
 596         return do_dlclose(vhandle, 1);
 597 }
 598
 599 char *dlerror(void)
 600 {
 601         const char *retval;
 602
 603         if (!_dl_error_number)
 604                 return NULL;
 605         retval = dl_error_names[_dl_error_number];
 606         _dl_error_number = 0;
 607         return (char *)retval;
 608 }
 609
 610 /*
 611  * Dump information to stderrr about the current loaded modules
 612  */
 613 static char *type[] = { "Lib", "Exe", "Int", "Mod" };
 614
 615 int dlinfo(void)
 616 {
 617         struct elf_resolve *tpnt;
 618         struct dyn_elf *rpnt, *hpnt;
 619
 620         fprintf(stderr, "List of loaded modules\n");
 621         /* First start with a complete list of all of the loaded files. */
 622         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 623                 fprintf(stderr, "\t%x %x %x %s %d %s\n",
 624                                 (unsigned) tpnt->loadaddr, (unsigned) tpnt,
 625                                 (unsigned) tpnt->symbol_scope,
 626                                 type[tpnt->libtype],
 627                                 tpnt->usage_count, tpnt->libname);
 628         }
 629
 630         /* Next dump the module list for the application itself */
 631         fprintf(stderr, "\nModules for application (%x):\n",
 632                         (unsigned) _dl_symbol_tables);
 633         for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next)
 634                 fprintf(stderr, "\t%x %s\n", (unsigned) rpnt->dyn, rpnt->dyn->libname);
 635
 636         for (hpnt = _dl_handles; hpnt; hpnt = hpnt->next_handle) {
 637                 fprintf(stderr, "Modules for handle %x\n", (unsigned) hpnt);
 638                 for (rpnt = hpnt; rpnt; rpnt = rpnt->next)
 639                         fprintf(stderr, "\t%x %s\n", (unsigned) rpnt->dyn,
 640                                         rpnt->dyn->libname);
 641         }
 642         return 0;
 643 }
 644
 645 int dladdr(const void *__address, Dl_info * __info)
 646 {
 647         struct elf_resolve *pelf;
 648         struct elf_resolve *rpnt;
 649
 650         _dl_map_cache();
 651
 652         /*
 653          * Try and locate the module address is in
 654          */
 655         pelf = NULL;
 656
 657 #if 0
 658         fprintf(stderr, "dladdr( %x, %x )\n", __address, __info);
 659 #endif
 660
 661         for (rpnt = _dl_loaded_modules; rpnt; rpnt = rpnt->next) {
 662                 struct elf_resolve *tpnt;
 663
 664                 tpnt = rpnt;
 665 #if 0
 666                 fprintf(stderr, "Module \"%s\" at %x\n",
 667                                 tpnt->libname, tpnt->loadaddr);
 668 #endif
 669                 if (tpnt->loadaddr < (ElfW(Addr)) __address
 670                                 && (pelf == NULL || pelf->loadaddr < tpnt->loadaddr)) {
 671                         pelf = tpnt;
 672                 }
 673         }
 674
 675         if (!pelf) {
 676                 return 0;
 677         }
 678
 679         /*
 680          * Try and locate the symbol of address
 681          */
 682
 683         {
 684                 char *strtab;
 685                 Elf32_Sym *symtab;
 686                 int hn, si;
 687                 int sf;
 688                 int sn = 0;
 689                 ElfW(Addr) sa;
 690
 691                 sa = 0;
 692                 symtab = (Elf32_Sym *) (pelf->dynamic_info[DT_SYMTAB]);
 693                 strtab = (char *) (pelf->dynamic_info[DT_STRTAB]);
 694
 695                 sf = 0;
 696                 for (hn = 0; hn < pelf->nbucket; hn++) {
 697                         for (si = pelf->elf_buckets[hn]; si; si = pelf->chains[si]) {
 698                                 ElfW(Addr) symbol_addr;
 699
 700                                 symbol_addr = pelf->loadaddr + symtab[si].st_value;
 701                                 if (symbol_addr <= (ElfW(Addr))__address && (!sf || sa < symbol_addr)) {
 702                                         sa = symbol_addr;
 703                                         sn = si;
 704                                         sf = 1;
 705                                 }
 706 #if 0
 707                                 fprintf(stderr, "Symbol \"%s\" at %x\n",
 708                                                 strtab + symtab[si].st_name, symbol_addr);
 709 #endif
 710                         }
 711                 }
 712
 713                 if (sf) {
 714                         __info->dli_fname = pelf->libname;
 715                         __info->dli_fbase = (void *)pelf->loadaddr;
 716                         __info->dli_sname = strtab + symtab[sn].st_name;
 717                         __info->dli_saddr = (void *)sa;
 718                 }
 719                 return 1;
 720         }
 721 }