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 #ifdef 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 extern struct elf_resolve * _dl_load_shared_library(int, struct dyn_elf **,
  45         struct elf_resolve *, char *, int);
  46 extern int _dl_fixup(struct dyn_elf *rpnt, int lazy);
  47 extern void _dl_protect_relro(struct elf_resolve * tpnt);
  48 extern int _dl_errno;
  49 extern struct dyn_elf *_dl_symbol_tables;
  50 extern struct dyn_elf *_dl_handles;
  51 extern struct elf_resolve *_dl_loaded_modules;
  52 extern struct r_debug *_dl_debug_addr;
  53 extern unsigned long _dl_error_number;
  54 extern void *(*_dl_malloc_function)(size_t);
  55 #ifdef __LDSO_CACHE_SUPPORT__
  56 int _dl_map_cache(void);
  57 int _dl_unmap_cache(void);
  58 #endif
  59 #ifdef __mips__
  60 extern void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy);
  61 #endif
  62 #ifdef __SUPPORT_LD_DEBUG__
  63 extern char *_dl_debug;
  64 #endif
  65
  66
  67 #else /* SHARED */
  68
  69 /* When libdl is linked as a static library, we need to replace all
  70  * the symbols that otherwise would have been loaded in from ldso... */
  71
  72 #ifdef __SUPPORT_LD_DEBUG__
  73 char *_dl_debug  = 0;
  74 #endif
  75 const char *_dl_progname       = "";        /* Program name */
  76 char *_dl_library_path         = 0;         /* Where we look for libraries */
  77 char *_dl_ldsopath             = 0;         /* Location of the shared lib loader */
  78 int _dl_errno                  = 0;         /* We can't use the real errno in ldso */
  79 size_t _dl_pagesize            = PAGE_SIZE; /* Store the page size for use later */
  80 /* This global variable is also to communicate with debuggers such as gdb. */
  81 struct r_debug *_dl_debug_addr = NULL;
  82 #define _dl_malloc malloc
  83 #include "../ldso/dl-debug.c"
  84 #include "dl-progname.h"
  85 #include "../ldso/dl-hash.c"
  86 #define _dl_trace_loaded_objects    0
  87 #include "../ldso/dl-elf.c"
  88 #endif /* SHARED */
  89
  90 #ifdef __SUPPORT_LD_DEBUG__
  91 # define _dl_if_debug_print(fmt, args...) \
  92         do { \
  93         if (_dl_debug) \
  94                 fprintf(stderr, "%s():%i: " fmt, __FUNCTION__, __LINE__, ## args); \
  95         } while (0)
  96 #else
  97 # define _dl_if_debug_print(fmt, args...)
  98 #endif
  99
 100 static int do_dlclose(void *, int need_fini);
 101
 102
 103 static const char *dl_error_names[] = {
 104         "",
 105         "File not found",
 106         "Unable to open /dev/zero",
 107         "Not an ELF file",
 108 #if defined (__i386__)
 109         "Not i386 binary",
 110 #elif defined (__sparc__)
 111         "Not sparc binary",
 112 #elif defined (__mc68000__)
 113         "Not m68k binary",
 114 #else
 115         "Unrecognized binary type",
 116 #endif
 117         "Not an ELF shared library",
 118         "Unable to mmap file",
 119         "No dynamic section",
 120 #ifdef ELF_USES_RELOCA
 121         "Unable to process REL relocs",
 122 #else
 123         "Unable to process RELA relocs",
 124 #endif
 125         "Bad handle",
 126         "Unable to resolve symbol"
 127 };
 128
 129 void __attribute__ ((destructor)) dl_cleanup(void)
 130 {
 131         struct dyn_elf *d;
 132         for (d = _dl_handles; d; d = d->next_handle) {
 133                 do_dlclose(d, 1);
 134         }
 135 }
 136
 137 void *dlopen(const char *libname, int flag)
 138 {
 139         struct elf_resolve *tpnt, *tfrom;
 140         struct dyn_elf *dyn_chain, *rpnt = NULL, *dyn_ptr, *relro_ptr, *handle;
 141         struct dyn_elf *dpnt;
 142         ElfW(Addr) from;
 143         struct elf_resolve *tpnt1;
 144         void (*dl_brk) (void);
 145         int now_flag;
 146         struct init_fini_list *tmp, *runp, *runp2, *dep_list;
 147         int nlist, i;
 148         struct elf_resolve **init_fini_list;
 149
 150         /* A bit of sanity checking... */
 151         if (!(flag & (RTLD_LAZY|RTLD_NOW))) {
 152                 _dl_error_number = LD_BAD_HANDLE;
 153                 return NULL;
 154         }
 155
 156         from = (ElfW(Addr)) __builtin_return_address(0);
 157
 158         /* Cover the trivial case first */
 159         if (!libname)
 160                 return _dl_symbol_tables;
 161
 162         _dl_map_cache();
 163
 164         /*
 165          * Try and locate the module we were called from - we
 166          * need this so that we get the correct RPATH/RUNPATH.  Note that
 167          * this is the current behavior under Solaris, but the
 168          * ABI+ specifies that we should only use the RPATH from
 169          * the application.  Thus this may go away at some time
 170          * in the future.
 171          */
 172         tfrom = NULL;
 173         for (dpnt = _dl_symbol_tables; dpnt; dpnt = dpnt->next) {
 174                 tpnt = dpnt->dyn;
 175                 if (tpnt->loadaddr < from
 176                                 && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr))
 177                         tfrom = tpnt;
 178         }
 179         for(rpnt = _dl_symbol_tables; rpnt && rpnt->next; rpnt=rpnt->next);
 180
 181         relro_ptr = rpnt;
 182         now_flag = (flag & RTLD_NOW) ? RTLD_NOW : 0;
 183         if (getenv("LD_BIND_NOW"))
 184                 now_flag = RTLD_NOW;
 185
 186         /* Try to load the specified library */
 187         _dl_if_debug_print("Trying to dlopen '%s', RTLD_GLOBAL:%d RTLD_NOW:%d\n",
 188                         (char*)libname, (flag & RTLD_GLOBAL ? 1:0), (now_flag & RTLD_NOW ? 1:0));
 189         tpnt = _dl_load_shared_library(0, &rpnt, tfrom, (char*)libname, 0);
 190
 191         if (tpnt == NULL) {
 192                 _dl_unmap_cache();
 193                 return NULL;
 194         }
 195         dyn_chain = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 196         _dl_memset(dyn_chain, 0, sizeof(struct dyn_elf));
 197         dyn_chain->dyn = tpnt;
 198         tpnt->rtld_flags |= (flag & RTLD_GLOBAL);
 199
 200         dyn_chain->next_handle = _dl_handles;
 201         _dl_handles = dyn_ptr = dyn_chain;
 202
 203         if (tpnt->usage_count > 1) {
 204                 _dl_if_debug_print("Lib: %s already opened\n", libname);
 205                 /* see if there is a handle from a earlier dlopen */
 206                 for (handle = _dl_handles->next_handle; handle; handle = handle->next_handle) {
 207                         if (handle->dyn == tpnt) {
 208                                 dyn_chain->init_fini.init_fini = handle->init_fini.init_fini;
 209                                 dyn_chain->init_fini.nlist = handle->init_fini.nlist;
 210                                 for(i=0; i < dyn_chain->init_fini.nlist; i++)
 211                                         dyn_chain->init_fini.init_fini[i]->rtld_flags |= (flag & RTLD_GLOBAL);
 212                                 dyn_chain->next = handle->next;
 213                                 break;
 214                         }
 215                 }
 216                 return dyn_chain;
 217         } else {
 218                 tpnt->init_flag |= DL_OPENED;
 219         }
 220
 221         _dl_if_debug_print("Looking for needed libraries\n");
 222         nlist = 0;
 223         runp = alloca(sizeof(*runp));
 224         runp->tpnt = tpnt;
 225         runp->next = NULL;
 226         dep_list = runp2 = runp;
 227         for (; runp; runp = runp->next)
 228         {
 229                 ElfW(Dyn) *dpnt;
 230                 char *lpntstr;
 231
 232                 nlist++;
 233                 runp->tpnt->init_fini = NULL; /* clear any previous dependcies */
 234                 for (dpnt = (ElfW(Dyn) *) runp->tpnt->dynamic_addr; dpnt->d_tag; dpnt++) {
 235                         if (dpnt->d_tag == DT_NEEDED) {
 236                                 char *name;
 237
 238                                 lpntstr = (char*) (runp->tpnt->dynamic_info[DT_STRTAB] +
 239                                                 dpnt->d_un.d_val);
 240                                 name = _dl_get_last_path_component(lpntstr);
 241                                 _dl_if_debug_print("Trying to load '%s', needed by '%s'\n",
 242                                                 lpntstr, runp->tpnt->libname);
 243                                 tpnt1 = _dl_load_shared_library(0, &rpnt, runp->tpnt, lpntstr, 0);
 244                                 if (!tpnt1)
 245                                         goto oops;
 246
 247                                 tpnt1->rtld_flags |= (flag & RTLD_GLOBAL);
 248
 249                                 if (tpnt1->usage_count == 1) {
 250                                         tpnt1->init_flag |= DL_OPENED;
 251                                         /* This list is for dlsym() and relocation */
 252                                         dyn_ptr->next = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 253                                         _dl_memset (dyn_ptr->next, 0, sizeof (struct dyn_elf));
 254                                         dyn_ptr = dyn_ptr->next;
 255                                         dyn_ptr->dyn = tpnt1;
 256                                 }
 257                                 if (tpnt1->init_flag & DL_OPENED) {
 258                                         /* Used to record RTLD_LOCAL scope */
 259                                         tmp = alloca(sizeof(struct init_fini_list));
 260                                         tmp->tpnt = tpnt1;
 261                                         tmp->next = runp->tpnt->init_fini;
 262                                         runp->tpnt->init_fini = tmp;
 263
 264                                         for (tmp=dep_list; tmp; tmp = tmp->next) {
 265                                                 if (tpnt1 == tmp->tpnt) { /* if match => cirular dependency, drop it */
 266                                                         _dl_if_debug_print("Circular dependency, skipping '%s',\n",
 267                                                                         tmp->tpnt->libname);
 268                                                         tpnt1->usage_count--;
 269                                                         break;
 270                                                 }
 271                                         }
 272                                         if (!tmp) { /* Don't add if circular dependency detected */
 273                                                 runp2->next = alloca(sizeof(*runp));
 274                                                 runp2 = runp2->next;
 275                                                 runp2->tpnt = tpnt1;
 276                                                 runp2->next = NULL;
 277                                         }
 278                                 }
 279                         }
 280                 }
 281         }
 282         init_fini_list = malloc(nlist * sizeof(struct elf_resolve *));
 283         dyn_chain->init_fini.init_fini = init_fini_list;
 284         dyn_chain->init_fini.nlist = nlist;
 285         i = 0;
 286         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 287                 init_fini_list[i++] = runp2->tpnt;
 288                 for(runp = runp2->tpnt->init_fini; runp; runp = runp->next){
 289                         if (!(runp->tpnt->rtld_flags & RTLD_GLOBAL)) {
 290                                 tmp = malloc(sizeof(struct init_fini_list));
 291                                 tmp->tpnt = runp->tpnt;
 292                                 tmp->next = runp2->tpnt->rtld_local;
 293                                 runp2->tpnt->rtld_local = tmp;
 294                         }
 295                 }
 296
 297         }
 298         /* Sort the INIT/FINI list in dependency order. */
 299         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 300                 int j, k;
 301                 for (j = 0; init_fini_list[j] != runp2->tpnt; ++j)
 302                         /* Empty */;
 303                 for (k = j + 1; k < nlist; ++k) {
 304                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 305
 306                         for (; runp; runp = runp->next) {
 307                                 if (runp->tpnt == runp2->tpnt) {
 308                                         struct elf_resolve *here = init_fini_list[k];
 309                                         _dl_if_debug_print("Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
 310                                         for (i = (k - j); i; --i)
 311                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 312                                         init_fini_list[j] = here;
 313                                         ++j;
 314                                         break;
 315                                 }
 316                         }
 317                 }
 318         }
 319 #ifdef __SUPPORT_LD_DEBUG__
 320         if(_dl_debug) {
 321                 fprintf(stderr, "\nINIT/FINI order and dependencies:\n");
 322                 for (i=0;i < nlist;i++) {
 323                         fprintf(stderr, "lib: %s has deps:\n", init_fini_list[i]->libname);
 324                         runp = init_fini_list[i]->init_fini;
 325                         for (; runp; runp = runp->next)
 326                                 printf(" %s ", runp->tpnt->libname);
 327                         printf("\n");
 328                 }
 329         }
 330 #endif
 331
 332         _dl_if_debug_print("Beginning dlopen relocation fixups\n");
 333         /*
 334          * OK, now all of the kids are tucked into bed in their proper addresses.
 335          * Now we go through and look for REL and RELA records that indicate fixups
 336          * to the GOT tables.  We need to do this in reverse order so that COPY
 337          * directives work correctly */
 338 #ifdef __mips__
 339         /*
 340          * Relocation of the GOT entries for MIPS have to be done
 341          * after all the libraries have been loaded.
 342          */
 343         _dl_perform_mips_global_got_relocations(tpnt, !now_flag);
 344 #endif
 345
 346         if (_dl_fixup(dyn_chain, now_flag))
 347                 goto oops;
 348
 349         /* Notify the debugger we have added some objects. */
 350         if (_dl_debug_addr) {
 351                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 352                 if (dl_brk != NULL) {
 353                         _dl_debug_addr->r_state = RT_ADD;
 354                         (*dl_brk) ();
 355
 356                         _dl_debug_addr->r_state = RT_CONSISTENT;
 357                         (*dl_brk) ();
 358                 }
 359         }
 360
 361 #ifdef SHARED
 362         /* Run the ctors and setup the dtors */
 363         for (i = nlist; i; --i) {
 364                 tpnt = init_fini_list[i-1];
 365                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 366                         continue;
 367                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 368
 369                 if (tpnt->dynamic_info[DT_INIT]) {
 370                         void (*dl_elf_func) (void);
 371                         dl_elf_func = (void (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 372                         if (dl_elf_func && *dl_elf_func != NULL) {
 373                                 _dl_if_debug_print("running ctors for library %s at '%p'\n",
 374                                                 tpnt->libname, dl_elf_func);
 375                                 (*dl_elf_func) ();
 376                         }
 377                 }
 378         }
 379 #endif
 380
 381         if (relro_ptr) {
 382                 for (rpnt = relro_ptr->next; rpnt; rpnt = rpnt->next) {
 383                         if (rpnt->dyn->relro_size)
 384                                 _dl_protect_relro(rpnt->dyn);
 385                 }
 386         }
 387         /* TODO:  Should we set the protections of all pages back to R/O now ? */
 388
 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 #if 0
 454 void *dlvsym(void *vhandle, const char *name, const char *version)
 455 {
 456         return dlsym(vhandle, name);
 457 }
 458 #endif
 459
 460 static int do_dlclose(void *vhandle, int need_fini)
 461 {
 462         struct dyn_elf *rpnt, *rpnt1, *rpnt1_tmp;
 463         struct init_fini_list *runp, *tmp;
 464         ElfW(Phdr) *ppnt;
 465         struct elf_resolve *tpnt, *run_tpnt;
 466         int (*dl_elf_fini) (void);
 467         void (*dl_brk) (void);
 468         struct dyn_elf *handle;
 469         unsigned int end;
 470         int i = 0, j;
 471
 472         handle = (struct dyn_elf *) vhandle;
 473         if (handle == _dl_symbol_tables)
 474                 return 0;
 475         rpnt1 = NULL;
 476         for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle) {
 477                 if (rpnt == handle)
 478                         break;
 479                 rpnt1 = rpnt;
 480         }
 481
 482         if (!rpnt) {
 483                 _dl_error_number = LD_BAD_HANDLE;
 484                 return 1;
 485         }
 486         if (rpnt1)
 487                 rpnt1->next_handle = rpnt->next_handle;
 488         else
 489                 _dl_handles = rpnt->next_handle;
 490         _dl_if_debug_print("%s: usage count: %d\n",
 491                         handle->dyn->libname, handle->dyn->usage_count);
 492         if (handle->dyn->usage_count != 1) {
 493                 handle->dyn->usage_count--;
 494                 free(handle);
 495                 return 0;
 496         }
 497         /* OK, this is a valid handle - now close out the file */
 498         for (j = 0; j < handle->init_fini.nlist; ++j) {
 499                 tpnt = handle->init_fini.init_fini[j];
 500                 if (--tpnt->usage_count == 0) {
 501                         if (tpnt->dynamic_info[DT_FINI] && need_fini &&
 502                             !(tpnt->init_flag & FINI_FUNCS_CALLED)) {
 503                                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 504                                 dl_elf_fini = (int (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 505                                 _dl_if_debug_print("running dtors for library %s at '%p'\n",
 506                                                 tpnt->libname, dl_elf_fini);
 507                                 (*dl_elf_fini) ();
 508                         }
 509
 510                         _dl_if_debug_print("unmapping: %s\n", tpnt->libname);
 511                         end = 0;
 512                         for (i = 0, ppnt = tpnt->ppnt;
 513                                         i < tpnt->n_phent; ppnt++, i++) {
 514                                 if (ppnt->p_type != PT_LOAD)
 515                                         continue;
 516                                 if (end < ppnt->p_vaddr + ppnt->p_memsz)
 517                                         end = ppnt->p_vaddr + ppnt->p_memsz;
 518                         }
 519                         _dl_munmap((void*)tpnt->loadaddr, end);
 520                         /* Free elements in RTLD_LOCAL scope list */
 521                         for (runp = tpnt->rtld_local; runp; runp = tmp) {
 522                                 tmp = runp->next;
 523                                 free(runp);
 524                         }
 525
 526                         /* Next, remove tpnt from the loaded_module list */
 527                         if (_dl_loaded_modules == tpnt) {
 528                                 _dl_loaded_modules = tpnt->next;
 529                                 if (_dl_loaded_modules)
 530                                         _dl_loaded_modules->prev = 0;
 531                         } else
 532                                 for (run_tpnt = _dl_loaded_modules; run_tpnt; run_tpnt = run_tpnt->next)
 533                                         if (run_tpnt->next == tpnt) {
 534                                                 _dl_if_debug_print("removing loaded_modules: %s\n", tpnt->libname);
 535                                                 run_tpnt->next = run_tpnt->next->next;
 536                                                 if (run_tpnt->next)
 537                                                         run_tpnt->next->prev = run_tpnt;
 538                                                 break;
 539                                         }
 540
 541                         /* Next, remove tpnt from the global symbol table list */
 542                         if (_dl_symbol_tables) {
 543                                 if (_dl_symbol_tables->dyn == tpnt) {
 544                                         _dl_symbol_tables = _dl_symbol_tables->next;
 545                                         if (_dl_symbol_tables)
 546                                                 _dl_symbol_tables->prev = 0;
 547                                 } else
 548                                         for (rpnt1 = _dl_symbol_tables; rpnt1->next; rpnt1 = rpnt1->next) {
 549                                                 if (rpnt1->next->dyn == tpnt) {
 550                                                         _dl_if_debug_print("removing symbol_tables: %s\n", tpnt->libname);
 551                                                         rpnt1_tmp = rpnt1->next->next;
 552                                                         free(rpnt1->next);
 553                                                         rpnt1->next = rpnt1_tmp;
 554                                                         if (rpnt1->next)
 555                                                                 rpnt1->next->prev = rpnt1;
 556                                                         break;
 557                                                 }
 558                                         }
 559                         }
 560                         free(tpnt->libname);
 561                         free(tpnt);
 562                 }
 563         }
 564         free(handle->init_fini.init_fini);
 565         free(handle);
 566
 567
 568         if (_dl_debug_addr) {
 569                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 570                 if (dl_brk != NULL) {
 571                         _dl_debug_addr->r_state = RT_DELETE;
 572                         (*dl_brk) ();
 573
 574                         _dl_debug_addr->r_state = RT_CONSISTENT;
 575                         (*dl_brk) ();
 576                 }
 577         }
 578
 579         return 0;
 580 }
 581
 582 int dlclose(void *vhandle)
 583 {
 584         return do_dlclose(vhandle, 1);
 585 }
 586
 587 char *dlerror(void)
 588 {
 589         const char *retval;
 590
 591         if (!_dl_error_number)
 592                 return NULL;
 593         retval = dl_error_names[_dl_error_number];
 594         _dl_error_number = 0;
 595         return (char *)retval;
 596 }
 597
 598 /*
 599  * Dump information to stderrr about the current loaded modules
 600  */
 601 static char *type[] = { "Lib", "Exe", "Int", "Mod" };
 602
 603 int dlinfo(void)
 604 {
 605         struct elf_resolve *tpnt;
 606         struct dyn_elf *rpnt, *hpnt;
 607
 608         fprintf(stderr, "List of loaded modules\n");
 609         /* First start with a complete list of all of the loaded files. */
 610         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 611                 fprintf(stderr, "\t%p %p %p %s %d %s\n",
 612                         tpnt->loadaddr, tpnt, tpnt->symbol_scope,
 613                         type[tpnt->libtype],
 614                         tpnt->usage_count, tpnt->libname);
 615         }
 616
 617         /* Next dump the module list for the application itself */
 618         fprintf(stderr, "\nModules for application (%p):\n", _dl_symbol_tables);
 619         for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next)
 620                 fprintf(stderr, "\t%p %s\n", rpnt->dyn, rpnt->dyn->libname);
 621
 622         for (hpnt = _dl_handles; hpnt; hpnt = hpnt->next_handle) {
 623                 fprintf(stderr, "Modules for handle %p\n", hpnt);
 624                 for (rpnt = hpnt; rpnt; rpnt = rpnt->next)
 625                         fprintf(stderr, "\t%p %s\n", rpnt->dyn, rpnt->dyn->libname);
 626         }
 627         return 0;
 628 }
 629
 630 int dladdr(const void *__address, Dl_info * __info)
 631 {
 632         struct elf_resolve *pelf;
 633         struct elf_resolve *rpnt;
 634
 635         _dl_map_cache();
 636
 637         /*
 638          * Try and locate the module address is in
 639          */
 640         pelf = NULL;
 641
 642 #if 0
 643         fprintf(stderr, "dladdr( %p, %p )\n", __address, __info);
 644 #endif
 645
 646         for (rpnt = _dl_loaded_modules; rpnt; rpnt = rpnt->next) {
 647                 struct elf_resolve *tpnt;
 648
 649                 tpnt = rpnt;
 650 #if 0
 651                 fprintf(stderr, "Module \"%s\" at %p\n",
 652                                 tpnt->libname, tpnt->loadaddr);
 653 #endif
 654                 if (tpnt->loadaddr < (ElfW(Addr)) __address
 655                                 && (pelf == NULL || pelf->loadaddr < tpnt->loadaddr)) {
 656                         pelf = tpnt;
 657                 }
 658         }
 659
 660         if (!pelf) {
 661                 return 0;
 662         }
 663
 664         /*
 665          * Try and locate the symbol of address
 666          */
 667
 668         {
 669                 char *strtab;
 670                 ElfW(Sym) *symtab;
 671                 int hn, si;
 672                 int sf;
 673                 int sn = 0;
 674                 ElfW(Addr) sa;
 675
 676                 sa = 0;
 677                 symtab = (ElfW(Sym) *) (pelf->dynamic_info[DT_SYMTAB]);
 678                 strtab = (char *) (pelf->dynamic_info[DT_STRTAB]);
 679
 680                 sf = 0;
 681                 for (hn = 0; hn < pelf->nbucket; hn++) {
 682                         for (si = pelf->elf_buckets[hn]; si; si = pelf->chains[si]) {
 683                                 ElfW(Addr) symbol_addr;
 684
 685                                 symbol_addr = pelf->loadaddr + symtab[si].st_value;
 686                                 if (symbol_addr <= (ElfW(Addr))__address && (!sf || sa < symbol_addr)) {
 687                                         sa = symbol_addr;
 688                                         sn = si;
 689                                         sf = 1;
 690                                 }
 691 #if 0
 692                                 fprintf(stderr, "Symbol \"%s\" at %p\n",
 693                                                 strtab + symtab[si].st_name, symbol_addr);
 694 #endif
 695                         }
 696                 }
 697
 698                 if (sf) {
 699                         __info->dli_fname = pelf->libname;
 700                         __info->dli_fbase = (void *)pelf->loadaddr;
 701                         __info->dli_sname = strtab + symtab[sn].st_name;
 702                         __info->dli_saddr = (void *)sa;
 703                 }
 704                 return 1;
 705         }
 706 }