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) 2000-2006 by Erik Andersen <andersen@uclibc.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 #include <ldso.h>
  34 #include <stdio.h>
  35
  36
  37 #ifdef SHARED
  38
  39 /* When libdl is loaded as a shared library, we need to load in
  40  * and use a pile of symbols from ldso... */
  41
  42 extern char *_dl_find_hash(const char *, struct dyn_elf *, struct elf_resolve *, int);
  43 extern struct elf_resolve * _dl_load_shared_library(int, struct dyn_elf **,
  44         struct elf_resolve *, char *, int);
  45 extern int _dl_fixup(struct dyn_elf *rpnt, int lazy);
  46 extern void _dl_protect_relro(struct elf_resolve * tpnt);
  47 extern int _dl_errno;
  48 extern struct dyn_elf *_dl_symbol_tables;
  49 extern struct dyn_elf *_dl_handles;
  50 extern struct elf_resolve *_dl_loaded_modules;
  51 extern struct r_debug *_dl_debug_addr;
  52 extern unsigned long _dl_error_number;
  53 extern void *(*_dl_malloc_function)(size_t);
  54 extern void _dl_run_init_array(struct elf_resolve *);
  55 extern void _dl_run_fini_array(struct elf_resolve *);
  56 #ifdef __LDSO_CACHE_SUPPORT__
  57 int _dl_map_cache(void);
  58 int _dl_unmap_cache(void);
  59 #endif
  60 #ifdef __mips__
  61 extern void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy);
  62 #endif
  63 #ifdef __SUPPORT_LD_DEBUG__
  64 extern char *_dl_debug;
  65 #endif
  66
  67
  68 #else /* SHARED */
  69
  70 /* When libdl is linked as a static library, we need to replace all
  71  * the symbols that otherwise would have been loaded in from ldso... */
  72
  73 #ifdef __SUPPORT_LD_DEBUG__
  74 char *_dl_debug  = 0;
  75 #endif
  76 const char *_dl_progname       = "";        /* Program name */
  77 char *_dl_library_path         = 0;         /* Where we look for libraries */
  78 char *_dl_ldsopath             = 0;         /* Location of the shared lib loader */
  79 int _dl_errno                  = 0;         /* We can't use the real errno in ldso */
  80 size_t _dl_pagesize            = PAGE_SIZE; /* Store the page size for use later */
  81 /* This global variable is also to communicate with debuggers such as gdb. */
  82 struct r_debug *_dl_debug_addr = NULL;
  83 #define _dl_malloc malloc
  84 #include "../ldso/dl-debug.c"
  85 #include LDSO_ELFINTERP
  86 #include "../ldso/dl-hash.c"
  87 #define _dl_trace_loaded_objects    0
  88 #include "../ldso/dl-elf.c"
  89 #endif /* SHARED */
  90
  91 #ifdef __SUPPORT_LD_DEBUG__
  92 # define _dl_if_debug_print(fmt, args...) \
  93         do { \
  94         if (_dl_debug) \
  95                 fprintf(stderr, "%s():%i: " fmt, __FUNCTION__, __LINE__, ## args); \
  96         } while (0)
  97 #else
  98 # define _dl_if_debug_print(fmt, args...)
  99 #endif
 100
 101 static int do_dlclose(void *, int need_fini);
 102
 103
 104 static const char *dl_error_names[] = {
 105         "",
 106         "File not found",
 107         "Unable to open /dev/zero",
 108         "Not an ELF file",
 109 #if defined (__i386__)
 110         "Not i386 binary",
 111 #elif defined (__sparc__)
 112         "Not sparc binary",
 113 #elif defined (__mc68000__)
 114         "Not m68k binary",
 115 #else
 116         "Unrecognized binary type",
 117 #endif
 118         "Not an ELF shared library",
 119         "Unable to mmap file",
 120         "No dynamic section",
 121 #ifdef ELF_USES_RELOCA
 122         "Unable to process REL relocs",
 123 #else
 124         "Unable to process RELA relocs",
 125 #endif
 126         "Bad handle",
 127         "Unable to resolve symbol"
 128 };
 129
 130 void dl_cleanup(void) __attribute__ ((destructor));
 131 void 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         ElfW(Addr) from;
 144         struct elf_resolve *tpnt1;
 145         void (*dl_brk) (void);
 146         int now_flag;
 147         struct init_fini_list *tmp, *runp, *runp2, *dep_list;
 148         unsigned int nlist, i;
 149         struct elf_resolve **init_fini_list;
 150
 151         /* A bit of sanity checking... */
 152         if (!(flag & (RTLD_LAZY|RTLD_NOW))) {
 153                 _dl_error_number = LD_BAD_HANDLE;
 154                 return NULL;
 155         }
 156
 157         from = (ElfW(Addr)) __builtin_return_address(0);
 158
 159         /* Cover the trivial case first */
 160         if (!libname)
 161                 return _dl_symbol_tables;
 162
 163         _dl_map_cache();
 164
 165         /*
 166          * Try and locate the module we were called from - we
 167          * need this so that we get the correct RPATH/RUNPATH.  Note that
 168          * this is the current behavior under Solaris, but the
 169          * ABI+ specifies that we should only use the RPATH from
 170          * the application.  Thus this may go away at some time
 171          * in the future.
 172          */
 173         {
 174                 struct dyn_elf *dpnt;
 175                 tfrom = NULL;
 176                 for (dpnt = _dl_symbol_tables; dpnt; dpnt = dpnt->next) {
 177                         tpnt = dpnt->dyn;
 178                         if (tpnt->loadaddr < from
 179                                         && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr))
 180                                 tfrom = tpnt;
 181                 }
 182         }
 183         for(rpnt = _dl_symbol_tables; rpnt && rpnt->next; rpnt=rpnt->next);
 184
 185         relro_ptr = rpnt;
 186         now_flag = (flag & RTLD_NOW) ? RTLD_NOW : 0;
 187         if (getenv("LD_BIND_NOW"))
 188                 now_flag = RTLD_NOW;
 189
 190         /* Try to load the specified library */
 191         _dl_if_debug_print("Trying to dlopen '%s', RTLD_GLOBAL:%d RTLD_NOW:%d\n",
 192                         (char*)libname, (flag & RTLD_GLOBAL ? 1:0), (now_flag & RTLD_NOW ? 1:0));
 193         tpnt = _dl_load_shared_library(0, &rpnt, tfrom, (char*)libname, 0);
 194
 195         if (tpnt == NULL) {
 196                 _dl_unmap_cache();
 197                 return NULL;
 198         }
 199         dyn_chain = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 200         _dl_memset(dyn_chain, 0, sizeof(struct dyn_elf));
 201         dyn_chain->dyn = tpnt;
 202         tpnt->rtld_flags |= (flag & RTLD_GLOBAL);
 203
 204         dyn_chain->next_handle = _dl_handles;
 205         _dl_handles = dyn_ptr = dyn_chain;
 206
 207         if (tpnt->usage_count > 1) {
 208                 _dl_if_debug_print("Lib: %s already opened\n", libname);
 209                 /* see if there is a handle from a earlier dlopen */
 210                 for (handle = _dl_handles->next_handle; handle; handle = handle->next_handle) {
 211                         if (handle->dyn == tpnt) {
 212                                 dyn_chain->init_fini.init_fini = handle->init_fini.init_fini;
 213                                 dyn_chain->init_fini.nlist = handle->init_fini.nlist;
 214                                 for(i=0; i < dyn_chain->init_fini.nlist; i++)
 215                                         dyn_chain->init_fini.init_fini[i]->rtld_flags |= (flag & RTLD_GLOBAL);
 216                                 dyn_chain->next = handle->next;
 217                                 break;
 218                         }
 219                 }
 220                 return dyn_chain;
 221         } else {
 222                 tpnt->init_flag |= DL_OPENED;
 223         }
 224
 225         _dl_if_debug_print("Looking for needed libraries\n");
 226         nlist = 0;
 227         runp = alloca(sizeof(*runp));
 228         runp->tpnt = tpnt;
 229         runp->next = NULL;
 230         dep_list = runp2 = runp;
 231         for (; runp; runp = runp->next)
 232         {
 233                 ElfW(Dyn) *dpnt;
 234                 char *lpntstr;
 235
 236                 nlist++;
 237                 runp->tpnt->init_fini = NULL; /* clear any previous dependcies */
 238                 for (dpnt = (ElfW(Dyn) *) runp->tpnt->dynamic_addr; dpnt->d_tag; dpnt++) {
 239                         if (dpnt->d_tag == DT_NEEDED) {
 240                                 lpntstr = (char*) (runp->tpnt->dynamic_info[DT_STRTAB] +
 241                                                 dpnt->d_un.d_val);
 242                                 _dl_if_debug_print("Trying to load '%s', needed by '%s'\n",
 243                                                 lpntstr, runp->tpnt->libname);
 244                                 tpnt1 = _dl_load_shared_library(0, &rpnt, runp->tpnt, lpntstr, 0);
 245                                 if (!tpnt1)
 246                                         goto oops;
 247
 248                                 tpnt1->rtld_flags |= (flag & RTLD_GLOBAL);
 249
 250                                 if (tpnt1->usage_count == 1) {
 251                                         tpnt1->init_flag |= DL_OPENED;
 252                                         /* This list is for dlsym() and relocation */
 253                                         dyn_ptr->next = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 254                                         _dl_memset (dyn_ptr->next, 0, sizeof (struct dyn_elf));
 255                                         dyn_ptr = dyn_ptr->next;
 256                                         dyn_ptr->dyn = tpnt1;
 257                                 }
 258                                 if (tpnt1->init_flag & DL_OPENED) {
 259                                         /* Used to record RTLD_LOCAL scope */
 260                                         tmp = alloca(sizeof(struct init_fini_list));
 261                                         tmp->tpnt = tpnt1;
 262                                         tmp->next = runp->tpnt->init_fini;
 263                                         runp->tpnt->init_fini = tmp;
 264
 265                                         for (tmp=dep_list; tmp; tmp = tmp->next) {
 266                                                 if (tpnt1 == tmp->tpnt) { /* if match => cirular dependency, drop it */
 267                                                         _dl_if_debug_print("Circular dependency, skipping '%s',\n",
 268                                                                         tmp->tpnt->libname);
 269                                                         tpnt1->usage_count--;
 270                                                         break;
 271                                                 }
 272                                         }
 273                                         if (!tmp) { /* Don't add if circular dependency detected */
 274                                                 runp2->next = alloca(sizeof(*runp));
 275                                                 runp2 = runp2->next;
 276                                                 runp2->tpnt = tpnt1;
 277                                                 runp2->next = NULL;
 278                                         }
 279                                 }
 280                         }
 281                 }
 282         }
 283         init_fini_list = malloc(nlist * sizeof(struct elf_resolve *));
 284         dyn_chain->init_fini.init_fini = init_fini_list;
 285         dyn_chain->init_fini.nlist = nlist;
 286         i = 0;
 287         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 288                 init_fini_list[i++] = runp2->tpnt;
 289                 for(runp = runp2->tpnt->init_fini; runp; runp = runp->next){
 290                         if (!(runp->tpnt->rtld_flags & RTLD_GLOBAL)) {
 291                                 tmp = malloc(sizeof(struct init_fini_list));
 292                                 tmp->tpnt = runp->tpnt;
 293                                 tmp->next = runp2->tpnt->rtld_local;
 294                                 runp2->tpnt->rtld_local = tmp;
 295                         }
 296                 }
 297
 298         }
 299         /* Sort the INIT/FINI list in dependency order. */
 300         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 301                 unsigned int j, k;
 302                 for (j = 0; init_fini_list[j] != runp2->tpnt; ++j)
 303                         /* Empty */;
 304                 for (k = j + 1; k < nlist; ++k) {
 305                         struct init_fini_list *ele = init_fini_list[k]->init_fini;
 306
 307                         for (; ele; ele = ele->next) {
 308                                 if (ele->tpnt == runp2->tpnt) {
 309                                         struct elf_resolve *here = init_fini_list[k];
 310                                         _dl_if_debug_print("Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
 311                                         for (i = (k - j); i; --i)
 312                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 313                                         init_fini_list[j] = here;
 314                                         ++j;
 315                                         break;
 316                                 }
 317                         }
 318                 }
 319         }
 320 #ifdef __SUPPORT_LD_DEBUG__
 321         if(_dl_debug) {
 322                 fprintf(stderr, "\nINIT/FINI order and dependencies:\n");
 323                 for (i=0;i < nlist;i++) {
 324                         fprintf(stderr, "lib: %s has deps:\n", init_fini_list[i]->libname);
 325                         runp = init_fini_list[i]->init_fini;
 326                         for (; runp; runp = runp->next)
 327                                 printf(" %s ", runp->tpnt->libname);
 328                         printf("\n");
 329                 }
 330         }
 331 #endif
 332
 333         _dl_if_debug_print("Beginning dlopen relocation fixups\n");
 334         /*
 335          * OK, now all of the kids are tucked into bed in their proper addresses.
 336          * Now we go through and look for REL and RELA records that indicate fixups
 337          * to the GOT tables.  We need to do this in reverse order so that COPY
 338          * directives work correctly */
 339 #ifdef __mips__
 340         /*
 341          * Relocation of the GOT entries for MIPS have to be done
 342          * after all the libraries have been loaded.
 343          */
 344         _dl_perform_mips_global_got_relocations(tpnt, !now_flag);
 345 #endif
 346
 347         if (_dl_fixup(dyn_chain, now_flag))
 348                 goto oops;
 349
 350         if (relro_ptr) {
 351                 for (rpnt = relro_ptr->next; rpnt; rpnt = rpnt->next) {
 352                         if (rpnt->dyn->relro_size)
 353                                 _dl_protect_relro(rpnt->dyn);
 354                 }
 355         }
 356         /* TODO:  Should we set the protections of all pages back to R/O now ? */
 357
 358
 359         /* Notify the debugger we have added some objects. */
 360         if (_dl_debug_addr) {
 361                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 362                 if (dl_brk != NULL) {
 363                         _dl_debug_addr->r_state = RT_ADD;
 364                         (*dl_brk) ();
 365
 366                         _dl_debug_addr->r_state = RT_CONSISTENT;
 367                         (*dl_brk) ();
 368                 }
 369         }
 370
 371 #ifdef SHARED
 372         /* Run the ctors and setup the dtors */
 373         for (i = nlist; i; --i) {
 374                 tpnt = init_fini_list[i-1];
 375                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 376                         continue;
 377                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 378
 379                 if (tpnt->dynamic_info[DT_INIT]) {
 380                         void (*dl_elf_func) (void);
 381                         dl_elf_func = (void (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 382                         if (dl_elf_func && *dl_elf_func != NULL) {
 383                                 _dl_if_debug_print("running ctors for library %s at '%p'\n",
 384                                                 tpnt->libname, dl_elf_func);
 385                                 (*dl_elf_func) ();
 386                         }
 387                 }
 388
 389                 _dl_run_init_array(tpnt);
 390         }
 391 #endif /* SHARED */
 392
 393         _dl_unmap_cache();
 394         return (void *) dyn_chain;
 395
 396 oops:
 397         /* Something went wrong.  Clean up and return NULL. */
 398         _dl_unmap_cache();
 399         do_dlclose(dyn_chain, 0);
 400         return NULL;
 401 }
 402
 403 void *dlsym(void *vhandle, const char *name)
 404 {
 405         struct elf_resolve *tpnt, *tfrom;
 406         struct dyn_elf *handle;
 407         ElfW(Addr) from;
 408         struct dyn_elf *rpnt;
 409         void *ret;
 410
 411         handle = (struct dyn_elf *) vhandle;
 412
 413         /* First of all verify that we have a real handle
 414            of some kind.  Return NULL if not a valid handle. */
 415
 416         if (handle == NULL)
 417                 handle = _dl_symbol_tables;
 418         else if (handle != RTLD_NEXT && handle != _dl_symbol_tables) {
 419                 for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle)
 420                         if (rpnt == handle)
 421                                 break;
 422                 if (!rpnt) {
 423                         _dl_error_number = LD_BAD_HANDLE;
 424                         return NULL;
 425                 }
 426         } else if (handle == RTLD_NEXT) {
 427                 /*
 428                  * Try and locate the module we were called from - we
 429                  * need this so that we know where to start searching
 430                  * from.  We never pass RTLD_NEXT down into the actual
 431                  * dynamic loader itself, as it doesn't know
 432                  * how to properly treat it.
 433                  */
 434                 from = (ElfW(Addr)) __builtin_return_address(0);
 435
 436                 tfrom = NULL;
 437                 for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next) {
 438                         tpnt = rpnt->dyn;
 439                         if (tpnt->loadaddr < from
 440                                         && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr)) {
 441                                 tfrom = tpnt;
 442                                 handle = rpnt->next;
 443                         }
 444                 }
 445         }
 446
 447         ret = _dl_find_hash((char*)name, handle, NULL, 0);
 448
 449         /*
 450          * Nothing found.
 451          */
 452         if (!ret)
 453                 _dl_error_number = LD_NO_SYMBOL;
 454         return ret;
 455 }
 456
 457 #if 0
 458 void *dlvsym(void *vhandle, const char *name, const char *version)
 459 {
 460         return dlsym(vhandle, name);
 461 }
 462 #endif
 463
 464 static int do_dlclose(void *vhandle, int need_fini)
 465 {
 466         struct dyn_elf *rpnt, *rpnt1, *rpnt1_tmp;
 467         struct init_fini_list *runp, *tmp;
 468         ElfW(Phdr) *ppnt;
 469         struct elf_resolve *tpnt, *run_tpnt;
 470         int (*dl_elf_fini) (void);
 471         void (*dl_brk) (void);
 472         struct dyn_elf *handle;
 473         unsigned int end;
 474         unsigned int i, j;
 475
 476         handle = (struct dyn_elf *) vhandle;
 477         if (handle == _dl_symbol_tables)
 478                 return 0;
 479         rpnt1 = NULL;
 480         for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle) {
 481                 if (rpnt == handle)
 482                         break;
 483                 rpnt1 = rpnt;
 484         }
 485
 486         if (!rpnt) {
 487                 _dl_error_number = LD_BAD_HANDLE;
 488                 return 1;
 489         }
 490         if (rpnt1)
 491                 rpnt1->next_handle = rpnt->next_handle;
 492         else
 493                 _dl_handles = rpnt->next_handle;
 494         _dl_if_debug_print("%s: usage count: %d\n",
 495                         handle->dyn->libname, handle->dyn->usage_count);
 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]
 506                              || tpnt->dynamic_info[DT_FINI_ARRAY])
 507                             && need_fini &&
 508                             !(tpnt->init_flag & FINI_FUNCS_CALLED)) {
 509                                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 510 #ifdef SHARED
 511                                 _dl_run_fini_array(tpnt);
 512 #endif
 513
 514                                 if (tpnt->dynamic_info[DT_FINI]) {
 515                                         dl_elf_fini = (int (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 516                                         _dl_if_debug_print("running dtors for library %s at '%p'\n",
 517                                                         tpnt->libname, dl_elf_fini);
 518                                         (*dl_elf_fini) ();
 519                                 }
 520                         }
 521
 522                         _dl_if_debug_print("unmapping: %s\n", tpnt->libname);
 523                         end = 0;
 524                         for (i = 0, ppnt = tpnt->ppnt;
 525                                         i < tpnt->n_phent; ppnt++, i++) {
 526                                 if (ppnt->p_type != PT_LOAD)
 527                                         continue;
 528                                 if (end < ppnt->p_vaddr + ppnt->p_memsz)
 529                                         end = ppnt->p_vaddr + ppnt->p_memsz;
 530                         }
 531                         _dl_munmap((void*)tpnt->loadaddr, end);
 532                         /* Free elements in RTLD_LOCAL scope list */
 533                         for (runp = tpnt->rtld_local; runp; runp = tmp) {
 534                                 tmp = runp->next;
 535                                 free(runp);
 536                         }
 537
 538                         /* Next, remove tpnt from the loaded_module list */
 539                         if (_dl_loaded_modules == tpnt) {
 540                                 _dl_loaded_modules = tpnt->next;
 541                                 if (_dl_loaded_modules)
 542                                         _dl_loaded_modules->prev = 0;
 543                         } else
 544                                 for (run_tpnt = _dl_loaded_modules; run_tpnt; run_tpnt = run_tpnt->next)
 545                                         if (run_tpnt->next == tpnt) {
 546                                                 _dl_if_debug_print("removing loaded_modules: %s\n", tpnt->libname);
 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) {
 555                                 if (_dl_symbol_tables->dyn == tpnt) {
 556                                         _dl_symbol_tables = _dl_symbol_tables->next;
 557                                         if (_dl_symbol_tables)
 558                                                 _dl_symbol_tables->prev = 0;
 559                                 } else
 560                                         for (rpnt1 = _dl_symbol_tables; rpnt1->next; rpnt1 = rpnt1->next) {
 561                                                 if (rpnt1->next->dyn == tpnt) {
 562                                                         _dl_if_debug_print("removing symbol_tables: %s\n", tpnt->libname);
 563                                                         rpnt1_tmp = rpnt1->next->next;
 564                                                         free(rpnt1->next);
 565                                                         rpnt1->next = rpnt1_tmp;
 566                                                         if (rpnt1->next)
 567                                                                 rpnt1->next->prev = rpnt1;
 568                                                         break;
 569                                                 }
 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 stderr about the current loaded modules
 612  */
 613 #ifdef __USE_GNU
 614 static char *type[] = { "Lib", "Exe", "Int", "Mod" };
 615
 616 int dlinfo(void)
 617 {
 618         struct elf_resolve *tpnt;
 619         struct dyn_elf *rpnt, *hpnt;
 620
 621         fprintf(stderr, "List of loaded modules\n");
 622         /* First start with a complete list of all of the loaded files. */
 623         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 624                 fprintf(stderr, "\t%p %p %p %s %d %s\n",
 625                         tpnt->loadaddr, tpnt, 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 (%p):\n", _dl_symbol_tables);
 632         for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next)
 633                 fprintf(stderr, "\t%p %s\n", rpnt->dyn, rpnt->dyn->libname);
 634
 635         for (hpnt = _dl_handles; hpnt; hpnt = hpnt->next_handle) {
 636                 fprintf(stderr, "Modules for handle %p\n", hpnt);
 637                 for (rpnt = hpnt; rpnt; rpnt = rpnt->next)
 638                         fprintf(stderr, "\t%p %s\n", rpnt->dyn, rpnt->dyn->libname);
 639         }
 640         return 0;
 641 }
 642
 643 int dladdr(const void *__address, Dl_info * __info)
 644 {
 645         struct elf_resolve *pelf;
 646         struct elf_resolve *rpnt;
 647
 648         _dl_map_cache();
 649
 650         /*
 651          * Try and locate the module address is in
 652          */
 653         pelf = NULL;
 654
 655 #if 0
 656         fprintf(stderr, "dladdr( %p, %p )\n", __address, __info);
 657 #endif
 658
 659         for (rpnt = _dl_loaded_modules; rpnt; rpnt = rpnt->next) {
 660                 struct elf_resolve *tpnt;
 661
 662                 tpnt = rpnt;
 663 #if 0
 664                 fprintf(stderr, "Module \"%s\" at %p\n",
 665                                 tpnt->libname, tpnt->loadaddr);
 666 #endif
 667                 if (tpnt->loadaddr < (ElfW(Addr)) __address
 668                                 && (pelf == NULL || pelf->loadaddr < tpnt->loadaddr)) {
 669                         pelf = tpnt;
 670                 }
 671         }
 672
 673         if (!pelf) {
 674                 return 0;
 675         }
 676
 677         /*
 678          * Try and locate the symbol of address
 679          */
 680
 681         {
 682                 char *strtab;
 683                 ElfW(Sym) *symtab;
 684                 unsigned int hn, si, sn, sf;
 685                 ElfW(Addr) sa;
 686
 687                 sa = 0;
 688                 symtab = (ElfW(Sym) *) (pelf->dynamic_info[DT_SYMTAB]);
 689                 strtab = (char *) (pelf->dynamic_info[DT_STRTAB]);
 690
 691                 sf = sn = 0;
 692                 for (hn = 0; hn < pelf->nbucket; hn++) {
 693                         for (si = pelf->elf_buckets[hn]; si; si = pelf->chains[si]) {
 694                                 ElfW(Addr) symbol_addr;
 695
 696                                 symbol_addr = pelf->loadaddr + symtab[si].st_value;
 697                                 if (symbol_addr <= (ElfW(Addr))__address && (!sf || sa < symbol_addr)) {
 698                                         sa = symbol_addr;
 699                                         sn = si;
 700                                         sf = 1;
 701                                 }
 702 #if 0
 703                                 fprintf(stderr, "Symbol \"%s\" at %p\n",
 704                                                 strtab + symtab[si].st_name, symbol_addr);
 705 #endif
 706                         }
 707                 }
 708
 709                 if (sf) {
 710                         __info->dli_fname = pelf->libname;
 711                         __info->dli_fbase = (void *)pelf->loadaddr;
 712                         __info->dli_sname = strtab + symtab[sn].st_name;
 713                         __info->dli_saddr = (void *)sa;
 714                 }
 715                 return 1;
 716         }
 717 }
 718 #endif