ldso/ldso/dl-elf.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * This file contains the helper routines to load an ELF shared
   4  * library into memory and add the symbol table info to the chain.
   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 #include "ldso.h"
  34
  35 #ifdef __LDSO_CACHE_SUPPORT__
  36
  37 static caddr_t _dl_cache_addr = NULL;
  38 static size_t _dl_cache_size = 0;
  39
  40 int _dl_map_cache(void)
  41 {
  42         int fd;
  43         struct stat st;
  44         header_t *header;
  45         libentry_t *libent;
  46         int i, strtabsize;
  47
  48         if (_dl_cache_addr == (caddr_t) - 1)
  49                 return -1;
  50         else if (_dl_cache_addr != NULL)
  51                 return 0;
  52
  53         if (_dl_stat(LDSO_CACHE, &st)
  54             || (fd = _dl_open(LDSO_CACHE, O_RDONLY, 0)) < 0) {
  55                 _dl_cache_addr = (caddr_t) - 1; /* so we won't try again */
  56                 return -1;
  57         }
  58
  59         _dl_cache_size = st.st_size;
  60         _dl_cache_addr = (caddr_t) _dl_mmap(0, _dl_cache_size, PROT_READ, MAP_SHARED, fd, 0);
  61         _dl_close(fd);
  62         if (_dl_mmap_check_error(_dl_cache_addr)) {
  63                 _dl_dprintf(2, "%s: can't map cache '%s'\n",
  64                                 _dl_progname, LDSO_CACHE);
  65                 return -1;
  66         }
  67
  68         header = (header_t *) _dl_cache_addr;
  69
  70         if (_dl_cache_size < sizeof(header_t) ||
  71                         _dl_memcmp(header->magic, LDSO_CACHE_MAGIC, LDSO_CACHE_MAGIC_LEN)
  72                         || _dl_memcmp(header->version, LDSO_CACHE_VER, LDSO_CACHE_VER_LEN)
  73                         || _dl_cache_size <
  74                         (sizeof(header_t) + header->nlibs * sizeof(libentry_t))
  75                         || _dl_cache_addr[_dl_cache_size - 1] != '\0')
  76         {
  77                 _dl_dprintf(2, "%s: cache '%s' is corrupt\n", _dl_progname,
  78                                 LDSO_CACHE);
  79                 goto fail;
  80         }
  81
  82         strtabsize = _dl_cache_size - sizeof(header_t) -
  83                 header->nlibs * sizeof(libentry_t);
  84         libent = (libentry_t *) & header[1];
  85
  86         for (i = 0; i < header->nlibs; i++) {
  87                 if (libent[i].sooffset >= strtabsize ||
  88                                 libent[i].liboffset >= strtabsize)
  89                 {
  90                         _dl_dprintf(2, "%s: cache '%s' is corrupt\n", _dl_progname, LDSO_CACHE);
  91                         goto fail;
  92                 }
  93         }
  94
  95         return 0;
  96
  97 fail:
  98         _dl_munmap(_dl_cache_addr, _dl_cache_size);
  99         _dl_cache_addr = (caddr_t) - 1;
 100         return -1;
 101 }
 102
 103 int _dl_unmap_cache(void)
 104 {
 105         if (_dl_cache_addr == NULL || _dl_cache_addr == (caddr_t) - 1)
 106                 return -1;
 107
 108 #if 1
 109         _dl_munmap(_dl_cache_addr, _dl_cache_size);
 110         _dl_cache_addr = NULL;
 111 #endif
 112
 113         return 0;
 114 }
 115 #endif
 116
 117
 118 void
 119 _dl_protect_relro (struct elf_resolve *l)
 120 {
 121         ElfW(Addr) start = ((l->loadaddr + l->relro_addr)
 122                             & ~(_dl_pagesize - 1));
 123         ElfW(Addr) end = ((l->loadaddr + l->relro_addr + l->relro_size)
 124                           & ~(_dl_pagesize - 1));
 125         _dl_if_debug_dprint("RELRO protecting %s:  start:%x, end:%x\n", l->libname, start, end);
 126         if (start != end &&
 127             _dl_mprotect ((void *) start, end - start, PROT_READ) < 0) {
 128                 _dl_dprintf(2, "%s: cannot apply additional memory protection after relocation", l->libname);
 129                 _dl_exit(0);
 130         }
 131 }
 132
 133 /* This function's behavior must exactly match that
 134  * in uClibc/ldso/util/ldd.c */
 135 static struct elf_resolve *
 136 search_for_named_library(const char *name, int secure, const char *path_list,
 137         struct dyn_elf **rpnt)
 138 {
 139         char *path, *path_n;
 140         char mylibname[2050];
 141         struct elf_resolve *tpnt;
 142         int done = 0;
 143
 144         if (path_list==NULL)
 145                 return NULL;
 146
 147         /* We need a writable copy of this string */
 148         path = _dl_strdup(path_list);
 149         if (!path) {
 150                 _dl_dprintf(2, "Out of memory!\n");
 151                 _dl_exit(0);
 152         }
 153
 154         /* Unlike ldd.c, don't bother to eliminate double //s */
 155
 156         /* Replace colons with zeros in path_list */
 157         /* : at the beginning or end of path maps to CWD */
 158         /* :: anywhere maps CWD */
 159         /* "" maps to CWD */
 160         path_n = path;
 161         do {
 162                 if (*path == 0) {
 163                         *path = ':';
 164                         done = 1;
 165                 }
 166                 if (*path == ':') {
 167                         *path = 0;
 168                         if (*path_n)
 169                                 _dl_strcpy(mylibname, path_n);
 170                         else
 171                                 _dl_strcpy(mylibname, "."); /* Assume current dir if empty path */
 172                         _dl_strcat(mylibname, "/");
 173                         _dl_strcat(mylibname, name);
 174                         if ((tpnt = _dl_load_elf_shared_library(secure, rpnt, mylibname)) != NULL)
 175                                 return tpnt;
 176                         path_n = path+1;
 177                 }
 178                 path++;
 179         } while (!done);
 180         return NULL;
 181 }
 182
 183 /* Check if the named library is already loaded... */
 184 struct elf_resolve *_dl_check_if_named_library_is_loaded(const char *full_libname,
 185                 int trace_loaded_objects)
 186 {
 187         const char *pnt, *pnt1;
 188         struct elf_resolve *tpnt1;
 189         const char *libname, *libname2;
 190         static const char libc[] = "libc.so.";
 191         static const char aborted_wrong_lib[] = "%s: aborted attempt to load %s!\n";
 192
 193         pnt = libname = full_libname;
 194
 195         _dl_if_debug_dprint("Checking if '%s' is already loaded\n", full_libname);
 196         /* quick hack to ensure mylibname buffer doesn't overflow.  don't
 197            allow full_libname or any directory to be longer than 1024. */
 198         if (_dl_strlen(full_libname) > 1024)
 199                 return NULL;
 200
 201         /* Skip over any initial initial './' and '/' stuff to
 202          * get the short form libname with no path garbage */
 203         pnt1 = _dl_strrchr(pnt, '/');
 204         if (pnt1) {
 205                 libname = pnt1 + 1;
 206         }
 207
 208         /* Make sure they are not trying to load the wrong C library!
 209          * This sometimes happens esp with shared libraries when the
 210          * library path is somehow wrong! */
 211 #define isdigit(c)  (c >= '0' && c <= '9')
 212         if ((_dl_strncmp(libname, libc, 8) == 0) &&  _dl_strlen(libname) >=8 &&
 213                         isdigit(libname[8]))
 214         {
 215                 /* Abort attempts to load glibc, libc5, etc */
 216                 if ( libname[8]!='0') {
 217                         if (!trace_loaded_objects) {
 218                                 _dl_dprintf(2, aborted_wrong_lib, libname, _dl_progname);
 219                                 _dl_exit(1);
 220                         }
 221                         return NULL;
 222                 }
 223         }
 224
 225         /* Critical step!  Weed out duplicates early to avoid
 226          * function aliasing, which wastes memory, and causes
 227          * really bad things to happen with weaks and globals. */
 228         for (tpnt1 = _dl_loaded_modules; tpnt1; tpnt1 = tpnt1->next) {
 229
 230                 /* Skip over any initial initial './' and '/' stuff to
 231                  * get the short form libname with no path garbage */
 232                 libname2 = tpnt1->libname;
 233                 pnt1 = _dl_strrchr(libname2, '/');
 234                 if (pnt1) {
 235                         libname2 = pnt1 + 1;
 236                 }
 237
 238                 if (_dl_strcmp(libname2, libname) == 0) {
 239                         /* Well, that was certainly easy */
 240                         return tpnt1;
 241                 }
 242         }
 243
 244         return NULL;
 245 }
 246
 247
 248 /* Used to return error codes back to dlopen et. al.  */
 249 unsigned long _dl_error_number;
 250 unsigned long _dl_internal_error_number;
 251
 252 struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
 253         struct elf_resolve *tpnt, char *full_libname, int __attribute__((unused)) trace_loaded_objects)
 254 {
 255         char *pnt;
 256         struct elf_resolve *tpnt1;
 257         char *libname;
 258
 259         _dl_internal_error_number = 0;
 260         libname = full_libname;
 261
 262         /* quick hack to ensure mylibname buffer doesn't overflow.  don't
 263            allow full_libname or any directory to be longer than 1024. */
 264         if (_dl_strlen(full_libname) > 1024)
 265                 goto goof;
 266
 267         /* Skip over any initial initial './' and '/' stuff to
 268          * get the short form libname with no path garbage */
 269         pnt = _dl_strrchr(libname, '/');
 270         if (pnt) {
 271                 libname = pnt + 1;
 272         }
 273
 274         /* Critical step!  Weed out duplicates early to avoid
 275          * function aliasing, which wastes memory, and causes
 276          * really bad things to happen with weaks and globals. */
 277         if ((tpnt1=_dl_check_if_named_library_is_loaded(libname, trace_loaded_objects))!=NULL) {
 278                 tpnt1->usage_count++;
 279                 return tpnt1;
 280         }
 281
 282         _dl_if_debug_dprint("\tfind library='%s'; searching\n", libname);
 283         /* If the filename has any '/', try it straight and leave it at that.
 284            For IBCS2 compatibility under linux, we substitute the string
 285            /usr/i486-sysv4/lib for /usr/lib in library names. */
 286
 287         if (libname != full_libname) {
 288                 _dl_if_debug_dprint("\ttrying file='%s'\n", full_libname);
 289                 tpnt1 = _dl_load_elf_shared_library(secure, rpnt, full_libname);
 290                 if (tpnt1) {
 291                         return tpnt1;
 292                 }
 293                 //goto goof;
 294         }
 295
 296         /*
 297          * The ABI specifies that RPATH is searched before LD_LIBRARY_PATH or
 298          * the default path of /usr/lib.  Check in rpath directories.
 299          */
 300 #ifdef __LDSO_RUNPATH__
 301         pnt = (tpnt ? (char *) tpnt->dynamic_info[DT_RPATH] : NULL);
 302         if (pnt) {
 303                 pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
 304                 _dl_if_debug_dprint("\tsearching RPATH='%s'\n", pnt);
 305                 if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL)
 306                         return tpnt1;
 307         }
 308 #endif
 309
 310         /* Check in LD_{ELF_}LIBRARY_PATH, if specified and allowed */
 311         if (_dl_library_path) {
 312                 _dl_if_debug_dprint("\tsearching LD_LIBRARY_PATH='%s'\n", _dl_library_path);
 313                 if ((tpnt1 = search_for_named_library(libname, secure, _dl_library_path, rpnt)) != NULL)
 314                 {
 315                         return tpnt1;
 316                 }
 317         }
 318
 319         /*
 320          * The ABI specifies that RUNPATH is searched after LD_LIBRARY_PATH.
 321          */
 322 #ifdef __LDSO_RUNPATH__
 323         pnt = (tpnt ? (char *)tpnt->dynamic_info[DT_RUNPATH] : NULL);
 324         if (pnt) {
 325                 pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
 326                 _dl_if_debug_dprint("\tsearching RUNPATH='%s'\n", pnt);
 327                 if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL)
 328                         return tpnt1;
 329         }
 330 #endif
 331
 332         /*
 333          * Where should the cache be searched?  There is no such concept in the
 334          * ABI, so we have some flexibility here.  For now, search it before
 335          * the hard coded paths that follow (i.e before /lib and /usr/lib).
 336          */
 337 #ifdef __LDSO_CACHE_SUPPORT__
 338         if (_dl_cache_addr != NULL && _dl_cache_addr != (caddr_t) - 1) {
 339                 int i;
 340                 header_t *header = (header_t *) _dl_cache_addr;
 341                 libentry_t *libent = (libentry_t *) & header[1];
 342                 char *strs = (char *) &libent[header->nlibs];
 343
 344                 _dl_if_debug_dprint("\tsearching cache='%s'\n", LDSO_CACHE);
 345                 for (i = 0; i < header->nlibs; i++) {
 346                         if ((libent[i].flags == LIB_ELF ||
 347                                                 libent[i].flags == LIB_ELF_LIBC0 ||
 348                                                 libent[i].flags == LIB_ELF_LIBC5) &&
 349                                         _dl_strcmp(libname, strs + libent[i].sooffset) == 0 &&
 350                                         (tpnt1 = _dl_load_elf_shared_library(secure,
 351                                                                                                                  rpnt, strs + libent[i].liboffset)))
 352                                 return tpnt1;
 353                 }
 354         }
 355 #endif
 356
 357         /* Look for libraries wherever the shared library loader
 358          * was installed */
 359         _dl_if_debug_dprint("\tsearching ldso dir='%s'\n", _dl_ldsopath);
 360         if ((tpnt1 = search_for_named_library(libname, secure, _dl_ldsopath, rpnt)) != NULL)
 361         {
 362                 return tpnt1;
 363         }
 364
 365
 366         /* Lastly, search the standard list of paths for the library.
 367            This list must exactly match the list in uClibc/ldso/util/ldd.c */
 368         _dl_if_debug_dprint("\tsearching full lib path list\n");
 369         if ((tpnt1 = search_for_named_library(libname, secure,
 370                                         UCLIBC_RUNTIME_PREFIX "lib:"
 371                                         UCLIBC_RUNTIME_PREFIX "usr/lib"
 372 #ifndef __LDSO_CACHE_SUPPORT__
 373                                         ":" UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib"
 374 #endif
 375                                         , rpnt)
 376                 ) != NULL)
 377         {
 378                 return tpnt1;
 379         }
 380
 381 goof:
 382         /* Well, we shot our wad on that one.  All we can do now is punt */
 383         if (_dl_internal_error_number)
 384                 _dl_error_number = _dl_internal_error_number;
 385         else
 386                 _dl_error_number = LD_ERROR_NOFILE;
 387         _dl_if_debug_dprint("Bummer: could not find '%s'!\n", libname);
 388         return NULL;
 389 }
 390
 391
 392 /*
 393  * Read one ELF library into memory, mmap it into the correct locations and
 394  * add the symbol info to the symbol chain.  Perform any relocations that
 395  * are required.
 396  */
 397
 398 struct elf_resolve *_dl_load_elf_shared_library(int secure,
 399         struct dyn_elf **rpnt, char *libname)
 400 {
 401         ElfW(Ehdr) *epnt;
 402         unsigned long dynamic_addr = 0;
 403         ElfW(Dyn) *dpnt;
 404         struct elf_resolve *tpnt;
 405         ElfW(Phdr) *ppnt;
 406         char *status, *header;
 407         unsigned long dynamic_info[DYNAMIC_SIZE];
 408         unsigned long *lpnt;
 409         unsigned long libaddr;
 410         unsigned long minvma = 0xffffffff, maxvma = 0;
 411         int i, flags, piclib, infile;
 412         ElfW(Addr) relro_addr = 0;
 413         size_t relro_size = 0;
 414
 415         /* If this file is already loaded, skip this step */
 416         tpnt = _dl_check_hashed_files(libname);
 417         if (tpnt) {
 418                 if (*rpnt) {
 419                         (*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 420                         _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
 421                         (*rpnt)->next->prev = (*rpnt);
 422                         *rpnt = (*rpnt)->next;
 423                         (*rpnt)->dyn = tpnt;
 424                         tpnt->symbol_scope = _dl_symbol_tables;
 425                 }
 426                 tpnt->usage_count++;
 427                 tpnt->libtype = elf_lib;
 428                 _dl_if_debug_dprint("file='%s';  already loaded\n", libname);
 429                 return tpnt;
 430         }
 431
 432         /* If we are in secure mode (i.e. a setu/gid binary using LD_PRELOAD),
 433            we don't load the library if it isn't setuid. */
 434
 435         if (secure) {
 436                 struct stat st;
 437
 438                 if (_dl_stat(libname, &st) || !(st.st_mode & S_ISUID))
 439                         return NULL;
 440         }
 441
 442         libaddr = 0;
 443         infile = _dl_open(libname, O_RDONLY, 0);
 444         if (infile < 0) {
 445 #if 0
 446                 /*
 447                  * NO!  When we open shared libraries we may search several paths.
 448                  * it is inappropriate to generate an error here.
 449                  */
 450                 _dl_dprintf(2, "%s: can't open '%s'\n", _dl_progname, libname);
 451 #endif
 452                 _dl_internal_error_number = LD_ERROR_NOFILE;
 453                 return NULL;
 454         }
 455
 456         header = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
 457                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 458         if (_dl_mmap_check_error(header)) {
 459                 _dl_dprintf(2, "%s: can't map '%s'\n", _dl_progname, libname);
 460                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 461                 _dl_close(infile);
 462                 return NULL;
 463         };
 464
 465         _dl_read(infile, header, _dl_pagesize);
 466         epnt = (ElfW(Ehdr) *) (intptr_t) header;
 467         if (epnt->e_ident[0] != 0x7f ||
 468                         epnt->e_ident[1] != 'E' ||
 469                         epnt->e_ident[2] != 'L' ||
 470                         epnt->e_ident[3] != 'F')
 471         {
 472                 _dl_dprintf(2, "%s: '%s' is not an ELF file\n", _dl_progname,
 473                                 libname);
 474                 _dl_internal_error_number = LD_ERROR_NOTELF;
 475                 _dl_close(infile);
 476                 _dl_munmap(header, _dl_pagesize);
 477                 return NULL;
 478         };
 479
 480         if ((epnt->e_type != ET_DYN) || (epnt->e_machine != MAGIC1
 481 #ifdef MAGIC2
 482                                 && epnt->e_machine != MAGIC2
 483 #endif
 484                                 ))
 485         {
 486                 _dl_internal_error_number =
 487                         (epnt->e_type != ET_DYN ? LD_ERROR_NOTDYN : LD_ERROR_NOTMAGIC);
 488                 _dl_dprintf(2, "%s: '%s' is not an ELF executable for " ELF_TARGET
 489                                 "\n", _dl_progname, libname);
 490                 _dl_close(infile);
 491                 _dl_munmap(header, _dl_pagesize);
 492                 return NULL;
 493         };
 494
 495         ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 496
 497         piclib = 1;
 498         for (i = 0; i < epnt->e_phnum; i++) {
 499
 500                 if (ppnt->p_type == PT_DYNAMIC) {
 501                         if (dynamic_addr)
 502                                 _dl_dprintf(2, "%s: '%s' has more than one dynamic section\n",
 503                                                 _dl_progname, libname);
 504                         dynamic_addr = ppnt->p_vaddr;
 505                 };
 506
 507                 if (ppnt->p_type == PT_LOAD) {
 508                         /* See if this is a PIC library. */
 509                         if (i == 0 && ppnt->p_vaddr > 0x1000000) {
 510                                 piclib = 0;
 511                                 minvma = ppnt->p_vaddr;
 512                         }
 513                         if (piclib && ppnt->p_vaddr < minvma) {
 514                                 minvma = ppnt->p_vaddr;
 515                         }
 516                         if (((unsigned long) ppnt->p_vaddr + ppnt->p_memsz) > maxvma) {
 517                                 maxvma = ppnt->p_vaddr + ppnt->p_memsz;
 518                         }
 519                 }
 520                 ppnt++;
 521         };
 522
 523         maxvma = (maxvma + ADDR_ALIGN) & ~ADDR_ALIGN;
 524         minvma = minvma & ~0xffffU;
 525
 526         flags = MAP_PRIVATE /*| MAP_DENYWRITE */ ;
 527         if (!piclib)
 528                 flags |= MAP_FIXED;
 529
 530         status = (char *) _dl_mmap((char *) (piclib ? 0 : minvma),
 531                         maxvma - minvma, PROT_NONE, flags | MAP_ANONYMOUS, -1, 0);
 532         if (_dl_mmap_check_error(status)) {
 533                 _dl_dprintf(2, "%s: can't map %s\n", _dl_progname, libname);
 534                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 535                 _dl_close(infile);
 536                 _dl_munmap(header, _dl_pagesize);
 537                 return NULL;
 538         };
 539         libaddr = (unsigned long) status;
 540         flags |= MAP_FIXED;
 541
 542         /* Get the memory to store the library */
 543         ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 544
 545         for (i = 0; i < epnt->e_phnum; i++) {
 546                 if (ppnt->p_type == PT_GNU_RELRO) {
 547                         relro_addr = ppnt->p_vaddr;
 548                         relro_size = ppnt->p_memsz;
 549                 }
 550                 if (ppnt->p_type == PT_LOAD) {
 551
 552                         /* See if this is a PIC library. */
 553                         if (i == 0 && ppnt->p_vaddr > 0x1000000) {
 554                                 piclib = 0;
 555                                 /* flags |= MAP_FIXED; */
 556                         }
 557
 558
 559
 560                         if (ppnt->p_flags & PF_W) {
 561                                 unsigned long map_size;
 562                                 char *cpnt;
 563
 564                                 status = (char *) _dl_mmap((char *) ((piclib ? libaddr : 0) +
 565                                                         (ppnt->p_vaddr & PAGE_ALIGN)), (ppnt->p_vaddr & ADDR_ALIGN)
 566                                                 + ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags, infile,
 567                                                 ppnt->p_offset & OFFS_ALIGN);
 568
 569                                 if (_dl_mmap_check_error(status)) {
 570                                         _dl_dprintf(2, "%s: can't map '%s'\n",
 571                                                         _dl_progname, libname);
 572                                         _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 573                                         _dl_munmap((char *) libaddr, maxvma - minvma);
 574                                         _dl_close(infile);
 575                                         _dl_munmap(header, _dl_pagesize);
 576                                         return NULL;
 577                                 };
 578
 579                                 /* Pad the last page with zeroes. */
 580                                 cpnt = (char *) (status + (ppnt->p_vaddr & ADDR_ALIGN) +
 581                                                 ppnt->p_filesz);
 582                                 while (((unsigned long) cpnt) & ADDR_ALIGN)
 583                                         *cpnt++ = 0;
 584
 585                                 /* I am not quite sure if this is completely
 586                                  * correct to do or not, but the basic way that
 587                                  * we handle bss segments is that we mmap
 588                                  * /dev/zero if there are any pages left over
 589                                  * that are not mapped as part of the file */
 590
 591                                 map_size = (ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) & PAGE_ALIGN;
 592
 593                                 if (map_size < ppnt->p_vaddr + ppnt->p_memsz)
 594                                         status = (char *) _dl_mmap((char *) map_size +
 595                                                         (piclib ? libaddr : 0),
 596                                                         ppnt->p_vaddr + ppnt->p_memsz - map_size,
 597                                                         LXFLAGS(ppnt->p_flags), flags | MAP_ANONYMOUS, -1, 0);
 598                         } else
 599                                 status = (char *) _dl_mmap((char *) (ppnt->p_vaddr & PAGE_ALIGN)
 600                                                 + (piclib ? libaddr : 0), (ppnt->p_vaddr & ADDR_ALIGN) +
 601                                                 ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags,
 602                                                 infile, ppnt->p_offset & OFFS_ALIGN);
 603                         if (_dl_mmap_check_error(status)) {
 604                                 _dl_dprintf(2, "%s: can't map '%s'\n", _dl_progname, libname);
 605                                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 606                                 _dl_munmap((char *) libaddr, maxvma - minvma);
 607                                 _dl_close(infile);
 608                                 _dl_munmap(header, _dl_pagesize);
 609                                 return NULL;
 610                         };
 611
 612                         /* if(libaddr == 0 && piclib) {
 613                            libaddr = (unsigned long) status;
 614                            flags |= MAP_FIXED;
 615                            }; */
 616                 };
 617                 ppnt++;
 618         };
 619         _dl_close(infile);
 620
 621         /* For a non-PIC library, the addresses are all absolute */
 622         if (piclib) {
 623                 dynamic_addr += (unsigned long) libaddr;
 624         }
 625
 626         /*
 627          * OK, the ELF library is now loaded into VM in the correct locations
 628          * The next step is to go through and do the dynamic linking (if needed).
 629          */
 630
 631         /* Start by scanning the dynamic section to get all of the pointers */
 632
 633         if (!dynamic_addr) {
 634                 _dl_internal_error_number = LD_ERROR_NODYNAMIC;
 635                 _dl_dprintf(2, "%s: '%s' is missing a dynamic section\n",
 636                                 _dl_progname, libname);
 637                 _dl_munmap(header, _dl_pagesize);
 638                 return NULL;
 639         }
 640
 641         dpnt = (ElfW(Dyn) *) dynamic_addr;
 642         _dl_memset(dynamic_info, 0, sizeof(dynamic_info));
 643         _dl_parse_dynamic_info(dpnt, dynamic_info, NULL, libaddr);
 644         /* If the TEXTREL is set, this means that we need to make the pages
 645            writable before we perform relocations.  Do this now. They get set
 646            back again later. */
 647
 648         if (dynamic_info[DT_TEXTREL]) {
 649 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 650                 ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 651                 for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
 652                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 653                                 _dl_mprotect((void *) ((piclib ? libaddr : 0) +
 654                                                         (ppnt->p_vaddr & PAGE_ALIGN)),
 655                                                 (ppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) ppnt->p_filesz,
 656                                                 PROT_READ | PROT_WRITE | PROT_EXEC);
 657                 }
 658 #else
 659                 _dl_dprintf(_dl_debug_file, "Can't modify %s's text section. Use GCC option -fPIC for shared objects, please.\n",libname);
 660                 _dl_exit(1);
 661 #endif
 662         }
 663
 664         tpnt = _dl_add_elf_hash_table(libname, (char *) libaddr, dynamic_info,
 665                         dynamic_addr, 0);
 666         tpnt->relro_addr = relro_addr;
 667         tpnt->relro_size = relro_size;
 668         tpnt->ppnt = (ElfW(Phdr) *)(intptr_t) (tpnt->loadaddr + epnt->e_phoff);
 669         tpnt->n_phent = epnt->e_phnum;
 670
 671         /*
 672          * Add this object into the symbol chain
 673          */
 674         if (*rpnt) {
 675                 (*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 676                 _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
 677                 (*rpnt)->next->prev = (*rpnt);
 678                 *rpnt = (*rpnt)->next;
 679                 (*rpnt)->dyn = tpnt;
 680                 tpnt->symbol_scope = _dl_symbol_tables;
 681         }
 682         tpnt->usage_count++;
 683         tpnt->libtype = elf_lib;
 684
 685         /*
 686          * OK, the next thing we need to do is to insert the dynamic linker into
 687          * the proper entry in the GOT so that the PLT symbols can be properly
 688          * resolved.
 689          */
 690
 691         lpnt = (unsigned long *) dynamic_info[DT_PLTGOT];
 692
 693         if (lpnt) {
 694                 lpnt = (unsigned long *) (dynamic_info[DT_PLTGOT]);
 695                 INIT_GOT(lpnt, tpnt);
 696         }
 697
 698         _dl_if_debug_dprint("\n\tfile='%s';  generating link map\n", libname);
 699         _dl_if_debug_dprint("\t\tdynamic: %x  base: %x\n", dynamic_addr, libaddr);
 700         _dl_if_debug_dprint("\t\t  entry: %x  phdr: %x  phnum: %x\n\n",
 701                         epnt->e_entry + libaddr, tpnt->ppnt, tpnt->n_phent);
 702
 703         _dl_munmap(header, _dl_pagesize);
 704
 705         return tpnt;
 706 }
 707
 708 /* now_flag must be RTLD_NOW or zero */
 709 int _dl_fixup(struct dyn_elf *rpnt, int now_flag)
 710 {
 711         int goof = 0;
 712         struct elf_resolve *tpnt;
 713         ElfW(Word) reloc_size, relative_count;
 714         ElfW(Addr) reloc_addr;
 715
 716         if (rpnt->next)
 717                 goof += _dl_fixup(rpnt->next, now_flag);
 718         tpnt = rpnt->dyn;
 719
 720         if(!(tpnt->init_flag & RELOCS_DONE))
 721                 _dl_if_debug_dprint("relocation processing: %s\n", tpnt->libname);
 722
 723         if (unlikely(tpnt->dynamic_info[UNSUPPORTED_RELOC_TYPE])) {
 724                 _dl_if_debug_dprint("%s: can't handle %s relocation records\n",
 725                                 _dl_progname, UNSUPPORTED_RELOC_STR);
 726                 goof++;
 727                 return goof;
 728         }
 729
 730         reloc_size = tpnt->dynamic_info[DT_RELOC_TABLE_SIZE];
 731 /* On some machines, notably SPARC & PPC, DT_REL* includes DT_JMPREL in its
 732    range.  Note that according to the ELF spec, this is completely legal! */
 733 #ifdef ELF_MACHINE_PLTREL_OVERLAP
 734         reloc_size -= tpnt->dynamic_info [DT_PLTRELSZ];
 735 #endif
 736         if (tpnt->dynamic_info[DT_RELOC_TABLE_ADDR] &&
 737             !(tpnt->init_flag & RELOCS_DONE)) {
 738                 tpnt->init_flag |= RELOCS_DONE;
 739                 reloc_addr = tpnt->dynamic_info[DT_RELOC_TABLE_ADDR];
 740                 relative_count = tpnt->dynamic_info[DT_RELCONT_IDX];
 741                 if (relative_count) { /* Optimize the XX_RELATIVE relocations if possible */
 742                         reloc_size -= relative_count * sizeof(ELF_RELOC);
 743                         elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count);
 744                         reloc_addr += relative_count * sizeof(ELF_RELOC);
 745                 }
 746                 goof += _dl_parse_relocation_information(rpnt,
 747                                 reloc_addr,
 748                                 reloc_size);
 749         }
 750         if (tpnt->dynamic_info[DT_BIND_NOW])
 751                 now_flag = RTLD_NOW;
 752         if (tpnt->dynamic_info[DT_JMPREL] &&
 753             (!(tpnt->init_flag & JMP_RELOCS_DONE) ||
 754              (now_flag && !(tpnt->rtld_flags & now_flag)))) {
 755                 tpnt->rtld_flags |= now_flag;
 756                 tpnt->init_flag |= JMP_RELOCS_DONE;
 757                 if (!(tpnt->rtld_flags & RTLD_NOW)) {
 758                         _dl_parse_lazy_relocation_information(rpnt,
 759                                         tpnt->dynamic_info[DT_JMPREL],
 760                                         tpnt->dynamic_info [DT_PLTRELSZ]);
 761                 } else {
 762                         goof += _dl_parse_relocation_information(rpnt,
 763                                         tpnt->dynamic_info[DT_JMPREL],
 764                                         tpnt->dynamic_info[DT_PLTRELSZ]);
 765                 }
 766         }
 767         return goof;
 768 }
 769
 770 /* Minimal printf which handles only %s, %d, and %x */
 771 void _dl_dprintf(int fd, const char *fmt, ...)
 772 {
 773 #if __WORDSIZE > 32
 774         long int num;
 775 #else
 776         int num;
 777 #endif
 778         va_list args;
 779         char *start, *ptr, *string;
 780         static char *buf;
 781
 782         buf = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
 783                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 784         if (_dl_mmap_check_error(buf)) {
 785                 _dl_write(fd, "mmap of a spare page failed!\n", 29);
 786                 _dl_exit(20);
 787         }
 788
 789         start = ptr = buf;
 790
 791         if (!fmt)
 792                 return;
 793
 794         if (_dl_strlen(fmt) >= (_dl_pagesize - 1)) {
 795                 _dl_write(fd, "overflow\n", 11);
 796                 _dl_exit(20);
 797         }
 798
 799         _dl_strcpy(buf, fmt);
 800         va_start(args, fmt);
 801
 802         while (start) {
 803                 while (*ptr != '%' && *ptr) {
 804                         ptr++;
 805                 }
 806
 807                 if (*ptr == '%') {
 808                         *ptr++ = '\0';
 809                         _dl_write(fd, start, _dl_strlen(start));
 810
 811                         switch (*ptr++) {
 812                                 case 's':
 813                                         string = va_arg(args, char *);
 814
 815                                         if (!string)
 816                                                 _dl_write(fd, "(null)", 6);
 817                                         else
 818                                                 _dl_write(fd, string, _dl_strlen(string));
 819                                         break;
 820
 821                                 case 'i':
 822                                 case 'd':
 823                                         {
 824                                                 char tmp[22];
 825 #if __WORDSIZE > 32
 826                                                 num = va_arg(args, long int);
 827 #else
 828                                                 num = va_arg(args, int);
 829 #endif
 830                                                 string = _dl_simple_ltoa(tmp, num);
 831                                                 _dl_write(fd, string, _dl_strlen(string));
 832                                                 break;
 833                                         }
 834                                 case 'x':
 835                                 case 'X':
 836                                         {
 837                                                 char tmp[22];
 838 #if __WORDSIZE > 32
 839                                                 num = va_arg(args, long int);
 840 #else
 841                                                 num = va_arg(args, int);
 842 #endif
 843                                                 string = _dl_simple_ltoahex(tmp, num);
 844                                                 _dl_write(fd, string, _dl_strlen(string));
 845                                                 break;
 846                                         }
 847                                 default:
 848                                         _dl_write(fd, "(null)", 6);
 849                                         break;
 850                         }
 851
 852                         start = ptr;
 853                 } else {
 854                         _dl_write(fd, start, _dl_strlen(start));
 855                         start = NULL;
 856                 }
 857         }
 858         _dl_munmap(buf, _dl_pagesize);
 859         return;
 860 }
 861
 862 char *_dl_strdup(const char *string)
 863 {
 864         char *retval;
 865         int len;
 866
 867         len = _dl_strlen(string);
 868         retval = _dl_malloc(len + 1);
 869         _dl_strcpy(retval, string);
 870         return retval;
 871 }
 872
 873 void _dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info[], void *debug_addr, ElfW(Addr) load_off)
 874 {
 875         __dl_parse_dynamic_info(dpnt, dynamic_info, debug_addr, load_off);
 876 }
 877 #ifdef __USE_GNU
 878 #if ! defined LIBDL || (! defined PIC && ! defined __PIC__)
 879 int
 880 __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, size_t size, void *data), void *data)
 881 {
 882         struct elf_resolve *l;
 883         struct dl_phdr_info info;
 884         int ret = 0;
 885
 886         for (l = _dl_loaded_modules; l != NULL; l = l->next) {
 887                 info.dlpi_addr = l->loadaddr;
 888                 info.dlpi_name = l->libname;
 889                 info.dlpi_phdr = l->ppnt;
 890                 info.dlpi_phnum = l->n_phent;
 891                 ret = callback (&info, sizeof (struct dl_phdr_info), data);
 892                 if (ret)
 893                         break;
 894         }
 895         return ret;
 896 }
 897 strong_alias(__dl_iterate_phdr, dl_iterate_phdr);
 898 #endif
 899 #endif