ldso/libdl/libdl.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Program to load an ELF binary on a linux system, and run it
   4  * after resolving ELF shared library symbols
   5  *
   6  * Copyright (C) 2000-2004 by Erik Andersen <andersen@codepoet.org>
   7  * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
   8  *                              David Engel, Hongjiu Lu and Mitch D'Souza
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. The name of the above contributors may not be
  16  *    used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32
  33 #define _GNU_SOURCE
  34 #include <ldso.h>
  35 #include <stdio.h>
  36
  37
  38 #if defined (__LIBDL_SHARED__)
  39
  40 /* When libdl is loaded as a shared library, we need to load in
  41  * and use a pile of symbols from ldso... */
  42
  43 extern char *_dl_find_hash(const char *, struct dyn_elf *, struct elf_resolve *, int)
  44         __attribute__ ((__weak__));
  45 extern struct elf_resolve * _dl_load_shared_library(int, struct dyn_elf **,
  46         struct elf_resolve *, char *, int) __attribute__ ((__weak__));
  47 extern int _dl_fixup(struct dyn_elf *rpnt, int lazy)
  48          __attribute__ ((__weak__));
  49 extern void _dl_protect_relro(struct elf_resolve * tpnt)
  50         __attribute__ ((__weak__));
  51 extern int _dl_errno __attribute__ ((__weak__));
  52 extern struct dyn_elf *_dl_symbol_tables __attribute__ ((__weak__));
  53 extern struct dyn_elf *_dl_handles __attribute__ ((__weak__));
  54 extern struct elf_resolve *_dl_loaded_modules __attribute__ ((__weak__));
  55 extern struct r_debug *_dl_debug_addr __attribute__ ((__weak__));
  56 extern unsigned long _dl_error_number __attribute__ ((__weak__));
  57 extern void *(*_dl_malloc_function)(size_t) __attribute__ ((__weak__));
  58 #ifdef __LDSO_CACHE_SUPPORT__
  59 int _dl_map_cache(void) __attribute__ ((__weak__));
  60 int _dl_unmap_cache(void) __attribute__ ((__weak__));
  61 #endif
  62 #ifdef __mips__
  63 extern void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy)
  64         __attribute__ ((__weak__));
  65 #endif
  66 #ifdef __SUPPORT_LD_DEBUG__
  67 extern char *_dl_debug __attribute__ ((__weak__));
  68 #endif
  69
  70
  71 #else /* __LIBDL_SHARED__ */
  72
  73 /* When libdl is linked as a static library, we need to replace all
  74  * the symbols that otherwise would have been loaded in from ldso... */
  75
  76 #ifdef __SUPPORT_LD_DEBUG__
  77 char *_dl_debug  = 0;
  78 #endif
  79 char *_dl_library_path         = 0;                 /* Where we look for libraries */
  80 char *_dl_ldsopath             = 0;                 /* Location of the shared lib loader */
  81 int _dl_errno                  = 0;         /* We can't use the real errno in ldso */
  82 size_t _dl_pagesize            = PAGE_SIZE; /* Store the page size for use later */
  83 /* This global variable is also to communicate with debuggers such as gdb. */
  84 struct r_debug *_dl_debug_addr = NULL;
  85 #define _dl_malloc malloc
  86 #include "dl-progname.h"
  87 #include "../ldso/dl-hash.c"
  88 #define _dl_trace_loaded_objects    0
  89 #include "../ldso/dl-elf.c"
  90 #endif
  91
  92 static int do_dlclose(void *, int need_fini);
  93
  94
  95 static const char *dl_error_names[] = {
  96         "",
  97         "File not found",
  98         "Unable to open /dev/zero",
  99         "Not an ELF file",
 100 #if defined (__i386__)
 101         "Not i386 binary",
 102 #elif defined (__sparc__)
 103         "Not sparc binary",
 104 #elif defined (__mc68000__)
 105         "Not m68k binary",
 106 #else
 107         "Unrecognized binary type",
 108 #endif
 109         "Not an ELF shared library",
 110         "Unable to mmap file",
 111         "No dynamic section",
 112 #ifdef ELF_USES_RELOCA
 113         "Unable to process REL relocs",
 114 #else
 115         "Unable to process RELA relocs",
 116 #endif
 117         "Bad handle",
 118         "Unable to resolve symbol"
 119 };
 120
 121 void __attribute__ ((destructor)) dl_cleanup(void)
 122 {
 123         struct dyn_elf *d;
 124         for (d = _dl_handles; d; d = d->next_handle) {
 125                 do_dlclose(d, 1);
 126         }
 127 }
 128
 129 void *dlopen(const char *libname, int flag)
 130 {
 131         struct elf_resolve *tpnt, *tfrom, *tcurr=NULL;
 132         struct dyn_elf *dyn_chain, *rpnt = NULL, *dyn_ptr, *relro_ptr, *handle;
 133         struct dyn_elf *dpnt;
 134         ElfW(Addr) from;
 135         struct elf_resolve *tpnt1;
 136         void (*dl_brk) (void);
 137         int now_flag;
 138         struct init_fini_list *tmp, *runp, *runp2, *dep_list;
 139         int nlist, i;
 140         struct elf_resolve **init_fini_list;
 141
 142         /* A bit of sanity checking... */
 143         if (!(flag & (RTLD_LAZY|RTLD_NOW))) {
 144                 _dl_error_number = LD_BAD_HANDLE;
 145                 return NULL;
 146         }
 147
 148         from = (ElfW(Addr)) __builtin_return_address(0);
 149
 150         /* Cover the trivial case first */
 151         if (!libname)
 152                 return _dl_symbol_tables;
 153
 154         _dl_map_cache();
 155
 156         /*
 157          * Try and locate the module we were called from - we
 158          * need this so that we get the correct RPATH.  Note that
 159          * this is the current behavior under Solaris, but the
 160          * ABI+ specifies that we should only use the RPATH from
 161          * the application.  Thus this may go away at some time
 162          * in the future.
 163          */
 164         tfrom = NULL;
 165         for (dpnt = _dl_symbol_tables; dpnt; dpnt = dpnt->next) {
 166                 tpnt = dpnt->dyn;
 167                 if (tpnt->loadaddr < from
 168                                 && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr))
 169                         tfrom = tpnt;
 170         }
 171         for(rpnt = _dl_symbol_tables; rpnt->next; rpnt=rpnt->next);
 172
 173         relro_ptr = rpnt;
 174         /* Try to load the specified library */
 175 #ifdef __SUPPORT_LD_DEBUG__
 176         if(_dl_debug)
 177                 fprintf(stderr, "Trying to dlopen '%s'\n", (char*)libname);
 178 #endif
 179         tpnt = _dl_load_shared_library(0, &rpnt, tfrom, (char*)libname, 0);
 180
 181         if (tpnt == NULL) {
 182                 _dl_unmap_cache();
 183                 return NULL;
 184         }
 185         dyn_chain = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 186         _dl_memset(dyn_chain, 0, sizeof(struct dyn_elf));
 187         dyn_chain->dyn = tpnt;
 188         tpnt->rtld_flags |= (flag & RTLD_GLOBAL);
 189
 190         dyn_chain->next_handle = _dl_handles;
 191         _dl_handles = dyn_ptr = dyn_chain;
 192
 193         if (tpnt->usage_count > 1) {
 194 #ifdef __SUPPORT_LD_DEBUG__
 195                 if(_dl_debug)
 196                         fprintf(stderr, "Lib: % already opened\n", libname);
 197 #endif
 198                 /* see if there is a handle from a earlier dlopen */
 199                 for (handle = _dl_handles->next_handle; handle; handle = handle->next_handle) {
 200                         if (handle->dyn == tpnt) {
 201                                 dyn_chain->init_fini.init_fini = handle->init_fini.init_fini;
 202                                 dyn_chain->init_fini.nlist = handle->init_fini.nlist;
 203                                 for(i=0; i < dyn_chain->init_fini.nlist; i++)
 204                                         dyn_chain->init_fini.init_fini[i]->rtld_flags |= (flag & RTLD_GLOBAL);
 205                                 dyn_chain->next = handle->next;
 206                                 break;
 207                         }
 208                 }
 209                 return dyn_chain;
 210         } else {
 211                 tpnt->init_flag |= DL_OPENED;
 212         }
 213
 214 #ifdef __SUPPORT_LD_DEBUG__
 215         if(_dl_debug)
 216                 fprintf(stderr, "Looking for needed libraries\n");
 217 #endif
 218         nlist = 0;
 219         runp = alloca(sizeof(*runp));
 220         runp->tpnt = tpnt;
 221         runp->next = NULL;
 222         dep_list = runp2 = runp;
 223         for (; runp; runp = runp->next)
 224         {
 225                 Elf32_Dyn *dpnt;
 226                 char *lpntstr;
 227
 228                 nlist++;
 229                 runp->tpnt->init_fini = NULL; /* clear any previous dependcies */
 230                 for (dpnt = (Elf32_Dyn *) runp->tpnt->dynamic_addr; dpnt->d_tag; dpnt++) {
 231                         if (dpnt->d_tag == DT_NEEDED) {
 232                                 char *name;
 233
 234                                 lpntstr = (char*) (runp->tpnt->dynamic_info[DT_STRTAB] +
 235                                                 dpnt->d_un.d_val);
 236                                 name = _dl_get_last_path_component(lpntstr);
 237 #ifdef __SUPPORT_LD_DEBUG__
 238                                 if(_dl_debug)
 239                                         fprintf(stderr, "Trying to load '%s', needed by '%s'\n",
 240                                                         lpntstr, runp->tpnt->libname);
 241 #endif
 242                                 tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, 0);
 243                                 if (!tpnt1)
 244                                         goto oops;
 245
 246                                 tpnt1->rtld_flags |= (flag & RTLD_GLOBAL);
 247
 248                                 if (tpnt1->usage_count == 1) {
 249                                         tpnt1->init_flag |= DL_OPENED;
 250                                         /* This list is for dlsym() and relocation */
 251                                         dyn_ptr->next = (struct dyn_elf *) malloc(sizeof(struct dyn_elf));
 252                                         _dl_memset (dyn_ptr->next, 0, sizeof (struct dyn_elf));
 253                                         dyn_ptr = dyn_ptr->next;
 254                                         dyn_ptr->dyn = tpnt1;
 255                                 }
 256                                 if (tpnt1->init_flag & DL_OPENED) {
 257                                         /* Used to record RTLD_LOCAL scope */
 258                                         tmp = alloca(sizeof(struct init_fini_list));
 259                                         tmp->tpnt = tpnt1;
 260                                         tmp->next = runp->tpnt->init_fini;
 261                                         runp->tpnt->init_fini = tmp;
 262
 263                                         for (tmp=dep_list; tmp; tmp = tmp->next) {
 264                                                 if (tpnt1 == tmp->tpnt) { /* if match => cirular dependency, drop it */
 265 #ifdef __SUPPORT_LD_DEBUG__
 266                                                         if(_dl_debug)
 267                                                                 fprintf(stderr, "Circular dependency, skipping '%s',\n",
 268                                                                         tmp->tpnt->libname);
 269 #endif
 270                                                         tpnt1->usage_count--;
 271                                                         break;
 272                                                 }
 273                                         }
 274                                         if (!tmp) { /* Don't add if circular dependency detected */
 275                                                 runp2->next = alloca(sizeof(*runp));
 276                                                 runp2 = runp2->next;
 277                                                 runp2->tpnt = tpnt1;
 278                                                 runp2->next = NULL;
 279                                         }
 280                                 }
 281                         }
 282                 }
 283         }
 284         init_fini_list = malloc(nlist * sizeof(struct elf_resolve *));
 285         dyn_chain->init_fini.init_fini = init_fini_list;
 286         dyn_chain->init_fini.nlist = nlist;
 287         i = 0;
 288         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 289                 init_fini_list[i++] = runp2->tpnt;
 290                 for(runp = runp2->tpnt->init_fini; runp; runp = runp->next){
 291                         if (!(runp->tpnt->rtld_flags & RTLD_GLOBAL)) {
 292                                 tmp = malloc(sizeof(struct init_fini_list));
 293                                 tmp->tpnt = runp->tpnt;
 294                                 tmp->next = runp2->tpnt->rtld_local;
 295                                 runp2->tpnt->rtld_local = tmp;
 296                         }
 297                 }
 298
 299         }
 300         /* Sort the INIT/FINI list in dependency order. */
 301         for (runp2 = dep_list; runp2; runp2 = runp2->next) {
 302                 int j, k;
 303                 for (j = 0; init_fini_list[j] != runp2->tpnt; ++j)
 304                         /* Empty */;
 305                 for (k = j + 1; k < nlist; ++k) {
 306                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 307
 308                         for (; runp; runp = runp->next) {
 309                                 if (runp->tpnt == runp2->tpnt) {
 310                                         struct elf_resolve *here = init_fini_list[k];
 311 #ifdef __SUPPORT_LD_DEBUG__
 312                                         if(_dl_debug)
 313                                                 fprintf(stderr, "Move %s from pos %d to %d in INIT/FINI list.\n", here->libname, k, j);
 314 #endif
 315                                         for (i = (k - j); i; --i)
 316                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 317                                         init_fini_list[j] = here;
 318                                         ++j;
 319                                         break;
 320                                 }
 321                         }
 322                 }
 323         }
 324 #ifdef __SUPPORT_LD_DEBUG__
 325         if(_dl_debug) {
 326                 fprintf(stderr, "\nINIT/FINI order and dependencies:\n");
 327                 for (i=0;i < nlist;i++) {
 328                         fprintf(stderr, "lib: %s has deps:\n", init_fini_list[i]->libname);
 329                         runp = init_fini_list[i]->init_fini;
 330                         for ( ;runp; runp = runp->next)
 331                                 printf(" %s ", runp->tpnt->libname);
 332                         printf("\n");
 333                 }
 334         }
 335 #endif
 336
 337 #ifdef __SUPPORT_LD_DEBUG__
 338         if(_dl_debug)
 339                 fprintf(stderr, "Beginning dlopen relocation fixups\n");
 340 #endif
 341         /*
 342          * OK, now all of the kids are tucked into bed in their proper addresses.
 343          * Now we go through and look for REL and RELA records that indicate fixups
 344          * to the GOT tables.  We need to do this in reverse order so that COPY
 345          * directives work correctly */
 346         now_flag = (flag & RTLD_NOW) ? RTLD_NOW : 0;
 347         if (getenv("LD_BIND_NOW"))
 348                 now_flag = RTLD_NOW;
 349
 350 #ifdef __mips__
 351         /*
 352          * Relocation of the GOT entries for MIPS have to be done
 353          * after all the libraries have been loaded.
 354          */
 355         _dl_perform_mips_global_got_relocations(tpnt, !now_flag);
 356 #endif
 357
 358         if (_dl_fixup(dyn_chain, now_flag))
 359                 goto oops;
 360
 361         for (rpnt = relro_ptr->next; rpnt; rpnt = rpnt->next) {
 362                 if (rpnt->dyn->relro_size)
 363                         _dl_protect_relro(rpnt->dyn);
 364         }
 365         /* TODO:  Should we set the protections of all pages back to R/O now ? */
 366
 367
 368         /* Notify the debugger we have added some objects. */
 369         if (_dl_debug_addr) {
 370                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 371                 if (dl_brk != NULL) {
 372                         _dl_debug_addr->r_state = RT_ADD;
 373                         (*dl_brk) ();
 374
 375                         _dl_debug_addr->r_state = RT_CONSISTENT;
 376                         (*dl_brk) ();
 377                 }
 378         }
 379
 380 #if defined (__LIBDL_SHARED__)
 381         /* Run the ctors and setup the dtors */
 382         for (i = nlist; i; --i) {
 383                 tpnt = init_fini_list[i-1];
 384                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 385                         continue;
 386                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 387
 388                 if (tpnt->dynamic_info[DT_INIT]) {
 389                         void (*dl_elf_func) (void);
 390                         dl_elf_func = (void (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 391                         if (dl_elf_func && *dl_elf_func != NULL) {
 392 #ifdef __SUPPORT_LD_DEBUG__
 393                                 if(_dl_debug)
 394                                         fprintf(stderr, "running ctors for library %s at '%x'\n", tpnt->libname, (unsigned)dl_elf_func);
 395 #endif
 396                                 (*dl_elf_func) ();
 397                         }
 398                 }
 399         }
 400 #endif
 401         _dl_unmap_cache();
 402         return (void *) dyn_chain;
 403
 404 oops:
 405         /* Something went wrong.  Clean up and return NULL. */
 406         _dl_unmap_cache();
 407         do_dlclose(dyn_chain, 0);
 408         return NULL;
 409 }
 410
 411 void *dlsym(void *vhandle, const char *name)
 412 {
 413         struct elf_resolve *tpnt, *tfrom;
 414         struct dyn_elf *handle;
 415         ElfW(Addr) from;
 416         struct dyn_elf *rpnt;
 417         void *ret;
 418
 419         handle = (struct dyn_elf *) vhandle;
 420
 421         /* First of all verify that we have a real handle
 422            of some kind.  Return NULL if not a valid handle. */
 423
 424         if (handle == NULL)
 425                 handle = _dl_symbol_tables;
 426         else if (handle != RTLD_NEXT && handle != _dl_symbol_tables) {
 427                 for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle)
 428                         if (rpnt == handle)
 429                                 break;
 430                 if (!rpnt) {
 431                         _dl_error_number = LD_BAD_HANDLE;
 432                         return NULL;
 433                 }
 434         } else if (handle == RTLD_NEXT) {
 435                 /*
 436                  * Try and locate the module we were called from - we
 437                  * need this so that we know where to start searching
 438                  * from.  We never pass RTLD_NEXT down into the actual
 439                  * dynamic loader itself, as it doesn't know
 440                  * how to properly treat it.
 441                  */
 442                 from = (ElfW(Addr)) __builtin_return_address(0);
 443
 444                 tfrom = NULL;
 445                 for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next) {
 446                         tpnt = rpnt->dyn;
 447                         if (tpnt->loadaddr < from
 448                                         && (tfrom == NULL || tfrom->loadaddr < tpnt->loadaddr)) {
 449                                 tfrom = tpnt;
 450                                 handle = rpnt->next;
 451                         }
 452                 }
 453         }
 454
 455         ret = _dl_find_hash((char*)name, handle, NULL, 0);
 456
 457         /*
 458          * Nothing found.
 459          */
 460         if (!ret)
 461                 _dl_error_number = LD_NO_SYMBOL;
 462         return ret;
 463 }
 464
 465 static int do_dlclose(void *vhandle, int need_fini)
 466 {
 467         struct dyn_elf *rpnt, *rpnt1;
 468         struct init_fini_list *runp, *tmp;
 469         ElfW(Phdr) *ppnt;
 470         struct elf_resolve *tpnt, *run_tpnt;
 471         int (*dl_elf_fini) (void);
 472         void (*dl_brk) (void);
 473         struct dyn_elf *handle;
 474         unsigned int end;
 475         int i = 0, j;
 476
 477         handle = (struct dyn_elf *) vhandle;
 478         if (handle == _dl_symbol_tables)
 479                 return 0;
 480         rpnt1 = NULL;
 481         for (rpnt = _dl_handles; rpnt; rpnt = rpnt->next_handle) {
 482                 if (rpnt == handle)
 483                         break;
 484                 rpnt1 = rpnt;
 485         }
 486
 487         if (!rpnt) {
 488                 _dl_error_number = LD_BAD_HANDLE;
 489                 return 1;
 490         }
 491         if (rpnt1)
 492                 rpnt1->next_handle = rpnt->next_handle;
 493         else
 494                 _dl_handles = rpnt->next_handle;
 495 #ifdef __SUPPORT_LD_DEBUG__
 496         if(_dl_debug)
 497                 fprintf(stderr, "dlclose: %s, usage count: %d\n", handle->dyn->libname, handle->dyn->usage_count);
 498 #endif
 499         if (handle->dyn->usage_count != 1) {
 500                 handle->dyn->usage_count--;
 501                 free(handle);
 502                 return 0;
 503         }
 504         /* OK, this is a valid handle - now close out the file */
 505         for (j = 0; j < handle->init_fini.nlist; ++j) {
 506                 tpnt = handle->init_fini.init_fini[j];
 507                 if (--tpnt->usage_count == 0) {
 508                         if (tpnt->dynamic_info[DT_FINI] && need_fini &&
 509                             !(tpnt->init_flag & FINI_FUNCS_CALLED)) {
 510                                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 511                                 dl_elf_fini = (int (*)(void)) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 512 #ifdef __SUPPORT_LD_DEBUG__
 513                                 if(_dl_debug)
 514                                         fprintf(stderr, "running dtors for library %s at '%x'\n", tpnt->libname, (unsigned)dl_elf_fini);
 515 #endif
 516                                 (*dl_elf_fini) ();
 517                         }
 518
 519 #ifdef __SUPPORT_LD_DEBUG__
 520                         if(_dl_debug)
 521                                 fprintf(stderr, "dlclose unmapping: %s\n", tpnt->libname);
 522 #endif
 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 #ifdef __SUPPORT_LD_DEBUG__
 547                                                 if(_dl_debug)
 548                                                         fprintf(stderr, "dlclose removing loaded_modules: %s\n", tpnt->libname);
 549 #endif
 550                                                 run_tpnt->next = run_tpnt->next->next;
 551                                                 if (run_tpnt->next)
 552                                                         run_tpnt->next->prev = run_tpnt;
 553                                                 break;
 554                                         }
 555
 556                         /* Next, remove tpnt from the global symbol table list */
 557                         if (_dl_symbol_tables->dyn == tpnt) {
 558                                 _dl_symbol_tables = _dl_symbol_tables->next;
 559                                 if (_dl_symbol_tables)
 560                                         _dl_symbol_tables->prev = 0;
 561                         } else
 562                                 for (rpnt1 = _dl_symbol_tables; rpnt1->next; rpnt1 = rpnt1->next) {
 563                                         if (rpnt1->next->dyn == tpnt) {
 564 #ifdef __SUPPORT_LD_DEBUG__
 565                                                 if(_dl_debug)
 566                                                         fprintf(stderr, "dlclose removing symbol_tables: %s\n", tpnt->libname);
 567 #endif
 568                                                 free(rpnt1->next);
 569                                                 rpnt1->next = rpnt1->next->next;
 570                                                 if (rpnt1->next)
 571                                                         rpnt1->next->prev = rpnt1;
 572                                                 break;
 573                                         }
 574                                 }
 575                         free(tpnt->libname);
 576                         free(tpnt);
 577                 }
 578         }
 579         free(handle->init_fini.init_fini);
 580         free(handle);
 581
 582
 583         if (_dl_debug_addr) {
 584                 dl_brk = (void (*)(void)) _dl_debug_addr->r_brk;
 585                 if (dl_brk != NULL) {
 586                         _dl_debug_addr->r_state = RT_DELETE;
 587                         (*dl_brk) ();
 588
 589                         _dl_debug_addr->r_state = RT_CONSISTENT;
 590                         (*dl_brk) ();
 591                 }
 592         }
 593
 594         return 0;
 595 }
 596
 597 int dlclose(void *vhandle)
 598 {
 599         return do_dlclose(vhandle, 1);
 600 }
 601
 602 char *dlerror(void)
 603 {
 604         const char *retval;
 605
 606         if (!_dl_error_number)
 607                 return NULL;
 608         retval = dl_error_names[_dl_error_number];
 609         _dl_error_number = 0;
 610         return (char *)retval;
 611 }
 612
 613 /*
 614  * Dump information to stderrr about the current loaded modules
 615  */
 616 static char *type[] = { "Lib", "Exe", "Int", "Mod" };
 617
 618 int dlinfo(void)
 619 {
 620         struct elf_resolve *tpnt;
 621         struct dyn_elf *rpnt, *hpnt;
 622
 623         fprintf(stderr, "List of loaded modules\n");
 624         /* First start with a complete list of all of the loaded files. */
 625         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 626                 fprintf(stderr, "\t%x %x %x %s %d %s\n",
 627                                 (unsigned) tpnt->loadaddr, (unsigned) tpnt,
 628                                 (unsigned) tpnt->symbol_scope,
 629                                 type[tpnt->libtype],
 630                                 tpnt->usage_count, tpnt->libname);
 631         }
 632
 633         /* Next dump the module list for the application itself */
 634         fprintf(stderr, "\nModules for application (%x):\n",
 635                         (unsigned) _dl_symbol_tables);
 636         for (rpnt = _dl_symbol_tables; rpnt; rpnt = rpnt->next)
 637                 fprintf(stderr, "\t%x %s\n", (unsigned) rpnt->dyn, rpnt->dyn->libname);
 638
 639         for (hpnt = _dl_handles; hpnt; hpnt = hpnt->next_handle) {
 640                 fprintf(stderr, "Modules for handle %x\n", (unsigned) hpnt);
 641                 for (rpnt = hpnt; rpnt; rpnt = rpnt->next)
 642                         fprintf(stderr, "\t%x %s\n", (unsigned) rpnt->dyn,
 643                                         rpnt->dyn->libname);
 644         }
 645         return 0;
 646 }
 647
 648 int dladdr(const void *__address, Dl_info * __info)
 649 {
 650         struct elf_resolve *pelf;
 651         struct elf_resolve *rpnt;
 652
 653         _dl_map_cache();
 654
 655         /*
 656          * Try and locate the module address is in
 657          */
 658         pelf = NULL;
 659
 660 #if 0
 661         fprintf(stderr, "dladdr( %x, %x )\n", __address, __info);
 662 #endif
 663
 664         for (rpnt = _dl_loaded_modules; rpnt; rpnt = rpnt->next) {
 665                 struct elf_resolve *tpnt;
 666
 667                 tpnt = rpnt;
 668 #if 0
 669                 fprintf(stderr, "Module \"%s\" at %x\n",
 670                                 tpnt->libname, tpnt->loadaddr);
 671 #endif
 672                 if (tpnt->loadaddr < (ElfW(Addr)) __address
 673                                 && (pelf == NULL || pelf->loadaddr < tpnt->loadaddr)) {
 674                         pelf = tpnt;
 675                 }
 676         }
 677
 678         if (!pelf) {
 679                 return 0;
 680         }
 681
 682         /*
 683          * Try and locate the symbol of address
 684          */
 685
 686         {
 687                 char *strtab;
 688                 Elf32_Sym *symtab;
 689                 int hn, si;
 690                 int sf;
 691                 int sn = 0;
 692                 ElfW(Addr) sa;
 693
 694                 sa = 0;
 695                 symtab = (Elf32_Sym *) (pelf->dynamic_info[DT_SYMTAB]);
 696                 strtab = (char *) (pelf->dynamic_info[DT_STRTAB]);
 697
 698                 sf = 0;
 699                 for (hn = 0; hn < pelf->nbucket; hn++) {
 700                         for (si = pelf->elf_buckets[hn]; si; si = pelf->chains[si]) {
 701                                 ElfW(Addr) symbol_addr;
 702
 703                                 symbol_addr = pelf->loadaddr + symtab[si].st_value;
 704                                 if (symbol_addr <= (ElfW(Addr))__address && (!sf || sa < symbol_addr)) {
 705                                         sa = symbol_addr;
 706                                         sn = si;
 707                                         sf = 1;
 708                                 }
 709 #if 0
 710                                 fprintf(stderr, "Symbol \"%s\" at %x\n",
 711                                                 strtab + symtab[si].st_name, symbol_addr);
 712 #endif
 713                         }
 714                 }
 715
 716                 if (sf) {
 717                         __info->dli_fname = pelf->libname;
 718                         __info->dli_fbase = (void *)pelf->loadaddr;
 719                         __info->dli_sname = strtab + symtab[sn].st_name;
 720                         __info->dli_saddr = (void *)sa;
 721                 }
 722                 return 1;
 723         }
 724 }