ldso/libdl/libdl.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Program to load an ELF binary on a linux system, and run it
   4  * after resolving ELF shared library symbols
   5  *
   6  * Copyright (C) 2000-2004 by Erik Andersen <andersen@codepoet.org>
   7  * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
   8  *                              David Engel, Hongjiu Lu and Mitch D'Souza
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. The name of the above contributors may not be
  16  *    used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32
  33 #define _GNU_SOURCE
  34 #include <ldso.h>
  35 #include <stdio.h>
  36
  37
  38 #if defined (__LIBDL_SHARED__)
  39
  40 /* When libdl is loaded as a shared library, we need to load in
  41  * and use a pile of symbols from ldso... */
  42
  43 extern char *_dl_find_hash(const char *, struct dyn_elf *, struct elf_resolve *, int)
  44         __attribute__ ((__weak__));
  45 extern struct elf_resolve * _dl_load_shared_library(int, struct dyn_elf **,
  46         struct elf_resolve *, char *, int) __attribute__ ((__weak__));
  47 extern int _dl_fixup(struct dyn_elf *rpnt, int lazy)
  48          __attribute__ ((__weak__));
  49 extern void _dl_protect_relro(struct elf_resolve * tpnt)
  50         __attribute__ ((__weak__));
  51 extern int _dl_errno __attribute__ ((__weak__));
  52 extern struct dyn_elf *_dl_symbol_tables __attribute__ ((__weak__));
  53 extern struct dyn_elf *_dl_handles __attribute__ ((__weak__));
  54 extern struct elf_resolve *_dl_loaded_modules __attribute__ ((__weak__));
  55 extern struct r_debug *_dl_debug_addr __attribute__ ((__weak__));
  56 extern unsigned long _dl_error_number __attribute__ ((__weak__));
  57 extern void *(*_dl_malloc_function)(size_t) __attribute__ ((__weak__));
  58 #ifdef __LDSO_CACHE_SUPPORT__
  59 int _dl_map_cache(void) __attribute__ ((__weak__));
  60 int _dl_unmap_cache(void) __attribute__ ((__weak__));
  61 #endif
  62 #ifdef __mips__
  63 extern void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy)
  64         __attribute__ ((__weak__));
  65 #endif
  66 #ifdef __SUPPORT_LD_DEBUG__
  67 extern char *_dl_debug __attribute__ ((__weak__));
  68 #endif
  69
  70
  71 #else /* __LIBDL_SHARED__ */
  72
  73 /* When libdl is linked as a static library, we need to replace all
  74  * the symbols that otherwise would have been loaded in from ldso... */
  75
  76 #ifdef __SUPPORT_LD_DEBUG__
  77 char *_dl_debug  = 0;
  78 #endif
  79 char *_dl_library_path         = 0;         /* Where we look for libraries */
  80 char *_dl_ldsopath             = 0;         /* Location of the shared lib loader */
  81 int _dl_errno                  = 0;         /* We can't use the real errno in ldso */
  82 size_t _dl_pagesize            = PAGE_SIZE; /* Store the page size for use later */
  83 /* This global variable is also to communicate with debuggers such as gdb. */
  84 struct r_debug *_dl_debug_addr = NULL;
  85 #define _dl_malloc malloc
  86 #include "../ldso/dl-debug.c"
  87 #include "dl-progname.h"
  88 #include "../ldso/dl-hash.c"
  89 #define _dl_trace_loaded_objects    0
  90 #include "../ldso/dl-elf.c"
  91 #endif /* __LIBDL_SHARED__ */
  92
  93 #ifdef __SUPPORT_LD_DEBUG__
  94 # define _dl_if_debug_print(fmt, args...) \
  95         do { \
  96         if (_dl_debug) \
  97                 fprintf(stderr, "%s():%i: " fmt, __FUNCTION__, __LINE__, ## args); \
  98         } while (0)
  99 #else
 100 # define _dl_if_debug_print(fmt, args...)
 101 #endif
 102
 103 static int do_dlclose(void *, int need_fini);
 104
 105
 106 static const char *dl_error_names[] = {
 107         "",
 108         "File not found",
 109         "Unable to open /dev/zero",
 110         "Not an ELF file",
 111 #if defined (__i386__)
 112         "Not i386 binary",
 113 #elif defined (__sparc__)
 114         "Not sparc binary",
 115 #elif defined (__mc68000__)
 116         "Not m68k binary",
 117 #else
 118         "Unrecognized binary type",
 119 #endif
 120         "Not an ELF shared library",
 121         "Unable to mmap file",
 122         "No dynamic section",
 123 #ifdef ELF_USES_RELOCA
 124         "Unable to process REL relocs",
 125 #else
 126         "Unable to process RELA relocs",
 127 #endif
 128         "Bad handle",
 129         "Unable to resolve symbol"
 130 };
 131
 132 void __attribute__ ((destructor)) dl_cleanup(void)
 133 {
 134         struct dyn_elf *d;
 135         for (d = _dl_handles; d; d = d->next_handle) {
 136                 do_dlclose(d, 1);
 137         }
 138 }
 139
 140 void *dlopen(const char *libname, int flag)
 141 {
 142         struct elf_resolve *tpnt, *tfrom;
 143         struct dyn_elf *dyn_chain, *rpnt = NULL, *dyn_ptr, *relro_ptr, *handle;
 144         struct dyn_elf *dpnt;
 145         ElfW(Addr) from;
 146         struct elf_resolve *tpnt1;
 147         void (*dl_brk) (void);
 148         int now_flag;
 149         struct init_fini_list *tmp, *runp, *runp2, *dep_list;
 150         int nlist, i;
 151         struct elf_resolve **init_fini_list;
 152
 153         /* A bit of sanity checking... */
 154         if (!(flag & (RTLD_LAZY|RTLD_NOW))) {
 155                 _dl_error_number = LD_BAD_HANDLE;
 156                 return NULL;
 157         }
 158
 159         from = (ElfW(Addr)) __builtin_return_address(0);
 160
 161         /* Cover the trivial case first */
 162         if (!libname)
 163                 return _dl_symbol_tables;
 164
 165         _dl_map_cache();
 166
 167         /*
 168          * Try and locate the module we were called from - we
 169          * need this so that we get the correct RPATH/RUNPATH.  Note that
 170          * this is the current behavior under Solaris, but the
 171          * ABI+ specifies that we should only use the RPATH from
 172          * the application.  Thus this may go away at some time
 173          * in the future.
 174          */
 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         for(rpnt = _dl_symbol_tables; rpnt && rpnt->next; rpnt=rpnt->next);
 183
 184         relro_ptr = rpnt;
 185         now_flag = (flag & RTLD_NOW) ? RTLD_NOW : 0;
 186         if (getenv("LD_BIND_NOW"))
 187                 now_flag = RTLD_NOW;
 188
 189         /* Try to load the specified library */
 190         _dl_if_debug_print("Trying to dlopen '%s', RTLD_GLOBAL:%d RTLD_NOW:%d\n",
 191                         (char*)libname, (flag & RTLD_GLOBAL ? 1:0), (now_flag & RTLD_NOW ? 1:0));
 192         tpnt = _dl_load_shared_library(0, &rpnt, tfrom, (char*)libname, 0);
 193
 194         if (tpnt == NULL) {
 195                 _dl_unmap_cache();
 196                 return NULL;
 197         }
 198         dyn_chain = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 199         _dl_memset(dyn_chain, 0, sizeof(struct dyn_elf));
 200         dyn_chain->dyn = tpnt;
 201         tpnt->rtld_flags |= (flag & RTLD_GLOBAL);
 202
 203         dyn_chain->next_handle = _dl_handles;
 204         _dl_handles = dyn_ptr = dyn_chain;
 205
 206         if (tpnt->usage_count > 1) {
 207                 _dl_if_debug_print("Lib: %s already opened\n", libname);
 208                 /* see if there is a handle from a earlier dlopen */
 209                 for (handle = _dl_handles->next_handle; handle; handle = handle->next_handle) {
 210                         if (handle->dyn == tpnt) {
 211                                 dyn_chain->init_fini.init_fini = handle->init_fini.init_fini;
 212                                 dyn_chain->init_fini.nlist = handle->init_fini.nlist;
 213                                 for(i=0; i < dyn_chain->init_fini.nlist; i++)
 214                                         dyn_chain->init_fini.init_fini[i]->rtld_flags |= (flag & RTLD_GLOBAL);
 215                                 dyn_chain->next = handle->next;
 216                                 break;
 217                         }
 218                 }
 219                 return dyn_chain;
 220         } else {
 221                 tpnt->init_flag |= DL_OPENED;
 222         }
 223
 224         _dl_if_debug_print("Looking for needed libraries\n");
 225         nlist = 0;
 226         runp = alloca(sizeof(*runp));
 227         runp->tpnt = tpnt;
 228         runp->next = NULL;
 229         dep_list = runp2 = runp;
 230         for (; runp; runp = runp->next)
 231         {
 232                 ElfW(Dyn) *dpnt;
 233                 char *lpntstr;
 234
 235                 nlist++;
 236                 runp->tpnt->init_fini = NULL; /* clear any previous dependcies */
 237                 for (dpnt = (ElfW(Dyn) *) runp->tpnt->dynamic_addr; dpnt->d_tag; dpnt++) {
 238                         if (dpnt->d_tag == DT_NEEDED) {
 239                                 char *name;
 240
 241                                 lpntstr = (char*) (runp->tpnt->dynamic_info[DT_STRTAB] +
 242                                                 dpnt->d_un.d_val);
 243                                 name = _dl_get_last_path_component(lpntstr);
 244                                 _dl_if_debug_print("Trying to load '%s', needed by '%s'\n",
 245                                                 lpntstr, runp->tpnt->libname);
 246                                 tpnt1 = _dl_load_shared_library(0, &rpnt, runp->tpnt, lpntstr, 0);
 247                                 if (!tpnt1)
 248                                         goto oops;
 249
 250                                 tpnt1->rtld_flags |= (flag & RTLD_GLOBAL);
 251
 252                                 if (tpnt1->usage_count == 1) {
 253                                         tpnt1->init_flag |= DL_OPENED;
 254                                         /* This list is for dlsym() and relocation */
 255                                         dyn_ptr->next = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 256                                         _dl_memset (dyn_ptr->next, 0, sizeof (struct dyn_elf));
 257                                         dyn_ptr = dyn_ptr->next;
 258                                         dyn_ptr->dyn = tpnt1;
 259                                 }
 260                                 if (tpnt1->init_flag & DL_OPENED) {
 261                                         /* Used to record RTLD_LOCAL scope */
 262                                         tmp = alloca(sizeof(struct init_fini_list));
 263                                         tmp->tpnt = tpnt1;
 264                                         tmp->next = runp->tpnt->init_fini;
 265                                         runp->tpnt->init_fini = tmp;
 266
 267                                         for (tmp=dep_list; tmp; tmp = tmp->next) {
 268                                                 if (tpnt1 == tmp->tpnt) { /* if match => cirular dependency, drop it */
 269                                                         _dl_if_debug_print("Circular dependency, skipping '%s',\n",
 270                                                                         tmp->tpnt->libname);
 271                                                         tpnt1->usage_count--;
 272                                                         break;
 273                                                 }
 274                                         }
 275                                         if (!tmp) { /* Don't add if circular dependency detected */
 276                                                 runp2->next = alloca(sizeof(*runp));
 277                                                 runp2 = runp2->next;
 278                                                 runp2->tpnt = tpnt1;
 279                                                 runp2->next = NULL;
 280                                         }
 281                                 }
 282                         }
 283                 }
 284         }
 285         init_fini_list = malloc(nlist * sizeof(struct elf_resolve *));
 286         dyn_chain->init_fini.init_fini = init_fini_list;
 287         dyn_chain->init_fini.nlist = nlist;
 288         i = 0;
 289         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 290                 init_fini_list[i++] = runp2->tpnt;
 291                 for(runp = runp2->tpnt->init_fini; runp; runp = runp->next){
 292                         if (!(runp->tpnt->rtld_flags & RTLD_GLOBAL)) {
 293                                 tmp = malloc(sizeof(struct init_fini_list));
 294                                 tmp->tpnt = runp->tpnt;
 295                                 tmp->next = runp2->tpnt->rtld_local;
 296                                 runp2->tpnt->rtld_local = tmp;
 297                         }
 298                 }
 299
 300         }
 301         /* Sort the INIT/FINI list in dependency order. */
 302         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 303                 int j, k;
 304                 for (j = 0; init_fini_list[j] != runp2->tpnt; ++j)
 305                         /* Empty */;
 306                 for (k = j + 1; k < nlist; ++k) {
 307                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 308
 309                         for (; runp; runp = runp->next) {
 310                                 if (runp->tpnt == runp2->tpnt) {
 311                                         struct elf_resolve *here = init_fini_list[k];
 312                                         _dl_if_debug_print("Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
 313                                         for (i = (k - j); i; --i)
 314                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 315                                         init_fini_list[j] = here;
 316                                         ++j;
 317                                         break;
 318                                 }
 319                         }
 320                 }
 321         }
 322 #ifdef __SUPPORT_LD_DEBUG__
 323         if(_dl_debug) {
 324                 fprintf(stderr, "\nINIT/FINI order and dependencies:\n");
 325                 for (i=0;i < nlist;i++) {
 326                         fprintf(stderr, "lib: %s has deps:\n", init_fini_list[i]->libname);
 327                         runp = init_fini_list[i]->init_fini;
 328                         for (; runp; runp = runp->next)
 329                                 printf(" %s ", runp->tpnt->libname);
 330                         printf("\n");
 331                 }
 332         }
 333 #endif
 334
 335         _dl_if_debug_print("Beginning dlopen relocation fixups\n");
 336         /*
 337          * OK, now all of the kids are tucked into bed in their proper addresses.
 338          * Now we go through and look for REL and RELA records that indicate fixups
 339          * to the GOT tables.  We need to do this in reverse order so that COPY
 340          * directives work correctly */
 341 #ifdef __mips__
 342         /*
 343          * Relocation of the GOT entries for MIPS have to be done
 344          * after all the libraries have been loaded.
 345          */
 346         _dl_perform_mips_global_got_relocations(tpnt, !now_flag);
 347 #endif
 348
 349         if (_dl_fixup(dyn_chain, now_flag))
 350                 goto oops;
 351
 352         if (relro_ptr) {
 353                 for (rpnt = relro_ptr->next; rpnt; rpnt = rpnt->next) {
 354                         if (rpnt->dyn->relro_size)
 355                                 _dl_protect_relro(rpnt->dyn);
 356                 }
 357         }
 358         /* TODO:  Should we set the protections of all pages back to R/O now ? */
 359
 360
 361         /* Notify the debugger we have added some objects. */
 362         if (_dl_debug_addr) {
 363                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 364                 if (dl_brk != NULL) {
 365                         _dl_debug_addr->r_state = RT_ADD;
 366                         (*dl_brk) ();
 367
 368                         _dl_debug_addr->r_state = RT_CONSISTENT;
 369                         (*dl_brk) ();
 370                 }
 371         }
 372
 373 #if defined (__LIBDL_SHARED__)
 374         /* Run the ctors and setup the dtors */
 375         for (i = nlist; i; --i) {
 376                 tpnt = init_fini_list[i-1];
 377                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 378                         continue;
 379                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 380
 381                 if (tpnt->dynamic_info[DT_INIT]) {
 382                         void (*dl_elf_func) (void);
 383                         dl_elf_func = (void (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 384                         if (dl_elf_func && *dl_elf_func != NULL) {
 385                                 _dl_if_debug_print("running ctors for library %s at '%p'\n",
 386                                                 tpnt->libname, dl_elf_func);
 387                                 (*dl_elf_func) ();
 388                         }
 389                 }
 390         }
 391 #endif
 392         _dl_unmap_cache();
 393         return (void *) dyn_chain;
 394
 395 oops:
 396         /* Something went wrong.  Clean up and return NULL. */
 397         _dl_unmap_cache();
 398         do_dlclose(dyn_chain, 0);
 399         return NULL;
 400 }
 401
 402 void *dlsym(void *vhandle, const char *name)
 403 {
 404         struct elf_resolve *tpnt, *tfrom;
 405         struct dyn_elf *handle;
 406         ElfW(Addr) from;
 407         struct dyn_elf *rpnt;
 408         void *ret;
 409
 410         handle = (struct dyn_elf *) vhandle;
 411
 412         /* First of all verify that we have a real handle
 413            of some kind.  Return NULL if not a valid handle. */
 414
 415         if (handle == NULL)
 416                 handle = _dl_symbol_tables;
 417         else if (handle != RTLD_NEXT && handle != _dl_symbol_tables) {
 418                 for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle)
 419                         if (rpnt == handle)
 420                                 break;
 421                 if (!rpnt) {
 422                         _dl_error_number = LD_BAD_HANDLE;
 423                         return NULL;
 424                 }
 425         } else if (handle == RTLD_NEXT) {
 426                 /*
 427                  * Try and locate the module we were called from - we
 428                  * need this so that we know where to start searching
 429                  * from.  We never pass RTLD_NEXT down into the actual
 430                  * dynamic loader itself, as it doesn't know
 431                  * how to properly treat it.
 432                  */
 433                 from = (ElfW(Addr)) __builtin_return_address(0);
 434
 435                 tfrom = NULL;
 436                 for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next) {
 437                         tpnt = rpnt->dyn;
 438                         if (tpnt->loadaddr < from
 439                                         && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr)) {
 440                                 tfrom = tpnt;
 441                                 handle = rpnt->next;
 442                         }
 443                 }
 444         }
 445
 446         ret = _dl_find_hash((char*)name, handle, NULL, 0);
 447
 448         /*
 449          * Nothing found.
 450          */
 451         if (!ret)
 452                 _dl_error_number = LD_NO_SYMBOL;
 453         return ret;
 454 }
 455
 456 static int do_dlclose(void *vhandle, int need_fini)
 457 {
 458         struct dyn_elf *rpnt, *rpnt1;
 459         struct init_fini_list *runp, *tmp;
 460         ElfW(Phdr) *ppnt;
 461         struct elf_resolve *tpnt, *run_tpnt;
 462         int (*dl_elf_fini) (void);
 463         void (*dl_brk) (void);
 464         struct dyn_elf *handle;
 465         unsigned int end;
 466         int i = 0, j;
 467
 468         handle = (struct dyn_elf *) vhandle;
 469         if (handle == _dl_symbol_tables)
 470                 return 0;
 471         rpnt1 = NULL;
 472         for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle) {
 473                 if (rpnt == handle)
 474                         break;
 475                 rpnt1 = rpnt;
 476         }
 477
 478         if (!rpnt) {
 479                 _dl_error_number = LD_BAD_HANDLE;
 480                 return 1;
 481         }
 482         if (rpnt1)
 483                 rpnt1->next_handle = rpnt->next_handle;
 484         else
 485                 _dl_handles = rpnt->next_handle;
 486         _dl_if_debug_print("%s: usage count: %d\n",
 487                         handle->dyn->libname, handle->dyn->usage_count);
 488         if (handle->dyn->usage_count != 1) {
 489                 handle->dyn->usage_count--;
 490                 free(handle);
 491                 return 0;
 492         }
 493         /* OK, this is a valid handle - now close out the file */
 494         for (j = 0; j < handle->init_fini.nlist; ++j) {
 495                 tpnt = handle->init_fini.init_fini[j];
 496                 if (--tpnt->usage_count == 0) {
 497                         if (tpnt->dynamic_info[DT_FINI] && need_fini &&
 498                             !(tpnt->init_flag & FINI_FUNCS_CALLED)) {
 499                                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 500                                 dl_elf_fini = (int (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 501                                 _dl_if_debug_print("running dtors for library %s at '%p'\n",
 502                                                 tpnt->libname, dl_elf_fini);
 503                                 (*dl_elf_fini) ();
 504                         }
 505
 506                         _dl_if_debug_print("unmapping: %s\n", tpnt->libname);
 507                         end = 0;
 508                         for (i = 0, ppnt = tpnt->ppnt;
 509                                         i < tpnt->n_phent; ppnt++, i++) {
 510                                 if (ppnt->p_type != PT_LOAD)
 511                                         continue;
 512                                 if (end < ppnt->p_vaddr + ppnt->p_memsz)
 513                                         end = ppnt->p_vaddr + ppnt->p_memsz;
 514                         }
 515                         _dl_munmap((void*)tpnt->loadaddr, end);
 516                         /* Free elements in RTLD_LOCAL scope list */
 517                         for (runp = tpnt->rtld_local; runp; runp = tmp) {
 518                                 tmp = runp->next;
 519                                 free(runp);
 520                         }
 521
 522                         /* Next, remove tpnt from the loaded_module list */
 523                         if (_dl_loaded_modules == tpnt) {
 524                                 _dl_loaded_modules = tpnt->next;
 525                                 if (_dl_loaded_modules)
 526                                         _dl_loaded_modules->prev = 0;
 527                         } else
 528                                 for (run_tpnt = _dl_loaded_modules; run_tpnt; run_tpnt = run_tpnt->next)
 529                                         if (run_tpnt->next == tpnt) {
 530                                                 _dl_if_debug_print("removing loaded_modules: %s\n", tpnt->libname);
 531                                                 run_tpnt->next = run_tpnt->next->next;
 532                                                 if (run_tpnt->next)
 533                                                         run_tpnt->next->prev = run_tpnt;
 534                                                 break;
 535                                         }
 536
 537                         /* Next, remove tpnt from the global symbol table list */
 538                         if (_dl_symbol_tables) {
 539                                 if (_dl_symbol_tables->dyn == tpnt) {
 540                                         _dl_symbol_tables = _dl_symbol_tables->next;
 541                                         if (_dl_symbol_tables)
 542                                                 _dl_symbol_tables->prev = 0;
 543                                 } else
 544                                         for (rpnt1 = _dl_symbol_tables; rpnt1->next; rpnt1 = rpnt1->next) {
 545                                                 if (rpnt1->next->dyn == tpnt) {
 546                                                         _dl_if_debug_print("removing symbol_tables: %s\n", tpnt->libname);
 547                                                         free(rpnt1->next);
 548                                                         rpnt1->next = rpnt1->next->next;
 549                                                         if (rpnt1->next)
 550                                                                 rpnt1->next->prev = rpnt1;
 551                                                         break;
 552                                                 }
 553                                         }
 554                         }
 555                         free(tpnt->libname);
 556                         free(tpnt);
 557                 }
 558         }
 559         free(handle->init_fini.init_fini);
 560         free(handle);
 561
 562
 563         if (_dl_debug_addr) {
 564                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 565                 if (dl_brk != NULL) {
 566                         _dl_debug_addr->r_state = RT_DELETE;
 567                         (*dl_brk) ();
 568
 569                         _dl_debug_addr->r_state = RT_CONSISTENT;
 570                         (*dl_brk) ();
 571                 }
 572         }
 573
 574         return 0;
 575 }
 576
 577 int dlclose(void *vhandle)
 578 {
 579         return do_dlclose(vhandle, 1);
 580 }
 581
 582 char *dlerror(void)
 583 {
 584         const char *retval;
 585
 586         if (!_dl_error_number)
 587                 return NULL;
 588         retval = dl_error_names[_dl_error_number];
 589         _dl_error_number = 0;
 590         return (char *)retval;
 591 }
 592
 593 /*
 594  * Dump information to stderrr about the current loaded modules
 595  */
 596 static char *type[] = { "Lib", "Exe", "Int", "Mod" };
 597
 598 int dlinfo(void)
 599 {
 600         struct elf_resolve *tpnt;
 601         struct dyn_elf *rpnt, *hpnt;
 602
 603         fprintf(stderr, "List of loaded modules\n");
 604         /* First start with a complete list of all of the loaded files. */
 605         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 606                 fprintf(stderr, "\t%p %p %p %s %d %s\n",
 607                         tpnt->loadaddr, tpnt, tpnt->symbol_scope,
 608                         type[tpnt->libtype],
 609                         tpnt->usage_count, tpnt->libname);
 610         }
 611
 612         /* Next dump the module list for the application itself */
 613         fprintf(stderr, "\nModules for application (%p):\n", _dl_symbol_tables);
 614         for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next)
 615                 fprintf(stderr, "\t%p %s\n", rpnt->dyn, rpnt->dyn->libname);
 616
 617         for (hpnt = _dl_handles; hpnt; hpnt = hpnt->next_handle) {
 618                 fprintf(stderr, "Modules for handle %p\n", hpnt);
 619                 for (rpnt = hpnt; rpnt; rpnt = rpnt->next)
 620                         fprintf(stderr, "\t%p %s\n", rpnt->dyn, rpnt->dyn->libname);
 621         }
 622         return 0;
 623 }
 624
 625 int dladdr(const void *__address, Dl_info * __info)
 626 {
 627         struct elf_resolve *pelf;
 628         struct elf_resolve *rpnt;
 629
 630         _dl_map_cache();
 631
 632         /*
 633          * Try and locate the module address is in
 634          */
 635         pelf = NULL;
 636
 637 #if 0
 638         fprintf(stderr, "dladdr( %p, %p )\n", __address, __info);
 639 #endif
 640
 641         for (rpnt = _dl_loaded_modules; rpnt; rpnt = rpnt->next) {
 642                 struct elf_resolve *tpnt;
 643
 644                 tpnt = rpnt;
 645 #if 0
 646                 fprintf(stderr, "Module \"%s\" at %p\n",
 647                                 tpnt->libname, tpnt->loadaddr);
 648 #endif
 649                 if (tpnt->loadaddr < (ElfW(Addr)) __address
 650                                 && (pelf == NULL || pelf->loadaddr < tpnt->loadaddr)) {
 651                         pelf = tpnt;
 652                 }
 653         }
 654
 655         if (!pelf) {
 656                 return 0;
 657         }
 658
 659         /*
 660          * Try and locate the symbol of address
 661          */
 662
 663         {
 664                 char *strtab;
 665                 ElfW(Sym) *symtab;
 666                 int hn, si;
 667                 int sf;
 668                 int sn = 0;
 669                 ElfW(Addr) sa;
 670
 671                 sa = 0;
 672                 symtab = (ElfW(Sym) *) (pelf->dynamic_info[DT_SYMTAB]);
 673                 strtab = (char *) (pelf->dynamic_info[DT_STRTAB]);
 674
 675                 sf = 0;
 676                 for (hn = 0; hn < pelf->nbucket; hn++) {
 677                         for (si = pelf->elf_buckets[hn]; si; si = pelf->chains[si]) {
 678                                 ElfW(Addr) symbol_addr;
 679
 680                                 symbol_addr = pelf->loadaddr + symtab[si].st_value;
 681                                 if (symbol_addr <= (ElfW(Addr))__address && (!sf || sa < symbol_addr)) {
 682                                         sa = symbol_addr;
 683                                         sn = si;
 684                                         sf = 1;
 685                                 }
 686 #if 0
 687                                 fprintf(stderr, "Symbol \"%s\" at %p\n",
 688                                                 strtab + symtab[si].st_name, symbol_addr);
 689 #endif
 690                         }
 691                 }
 692
 693                 if (sf) {
 694                         __info->dli_fname = pelf->libname;
 695                         __info->dli_fbase = (void *)pelf->loadaddr;
 696                         __info->dli_sname = strtab + symtab[sn].st_name;
 697                         __info->dli_saddr = (void *)sa;
 698                 }
 699                 return 1;
 700         }
 701 }