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 /* Used to return error codes back to dlopen et. al.  */
 184 unsigned long _dl_error_number;
 185 unsigned long _dl_internal_error_number;
 186
 187 struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
 188         struct elf_resolve *tpnt, char *full_libname, int __attribute__((unused)) trace_loaded_objects)
 189 {
 190         char *pnt;
 191         struct elf_resolve *tpnt1;
 192         char *libname;
 193
 194         _dl_internal_error_number = 0;
 195         libname = full_libname;
 196
 197         /* quick hack to ensure mylibname buffer doesn't overflow.  don't
 198            allow full_libname or any directory to be longer than 1024. */
 199         if (_dl_strlen(full_libname) > 1024)
 200                 goto goof;
 201
 202         /* Skip over any initial initial './' and '/' stuff to
 203          * get the short form libname with no path garbage */
 204         pnt = _dl_strrchr(libname, '/');
 205         if (pnt) {
 206                 libname = pnt + 1;
 207         }
 208
 209         _dl_if_debug_dprint("\tfind library='%s'; searching\n", libname);
 210         /* If the filename has any '/', try it straight and leave it at that.
 211            For IBCS2 compatibility under linux, we substitute the string
 212            /usr/i486-sysv4/lib for /usr/lib in library names. */
 213
 214         if (libname != full_libname) {
 215                 _dl_if_debug_dprint("\ttrying file='%s'\n", full_libname);
 216                 tpnt1 = _dl_load_elf_shared_library(secure, rpnt, full_libname);
 217                 if (tpnt1) {
 218                         return tpnt1;
 219                 }
 220         }
 221
 222         /*
 223          * The ABI specifies that RPATH is searched before LD_LIBRARY_PATH or
 224          * the default path of /usr/lib.  Check in rpath directories.
 225          */
 226 #ifdef __LDSO_RUNPATH__
 227         pnt = (tpnt ? (char *) tpnt->dynamic_info[DT_RPATH] : NULL);
 228         if (pnt) {
 229                 pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
 230                 _dl_if_debug_dprint("\tsearching RPATH='%s'\n", pnt);
 231                 if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL)
 232                         return tpnt1;
 233         }
 234 #endif
 235
 236         /* Check in LD_{ELF_}LIBRARY_PATH, if specified and allowed */
 237         if (_dl_library_path) {
 238                 _dl_if_debug_dprint("\tsearching LD_LIBRARY_PATH='%s'\n", _dl_library_path);
 239                 if ((tpnt1 = search_for_named_library(libname, secure, _dl_library_path, rpnt)) != NULL)
 240                 {
 241                         return tpnt1;
 242                 }
 243         }
 244
 245         /*
 246          * The ABI specifies that RUNPATH is searched after LD_LIBRARY_PATH.
 247          */
 248 #ifdef __LDSO_RUNPATH__
 249         pnt = (tpnt ? (char *)tpnt->dynamic_info[DT_RUNPATH] : NULL);
 250         if (pnt) {
 251                 pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
 252                 _dl_if_debug_dprint("\tsearching RUNPATH='%s'\n", pnt);
 253                 if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL)
 254                         return tpnt1;
 255         }
 256 #endif
 257
 258         /*
 259          * Where should the cache be searched?  There is no such concept in the
 260          * ABI, so we have some flexibility here.  For now, search it before
 261          * the hard coded paths that follow (i.e before /lib and /usr/lib).
 262          */
 263 #ifdef __LDSO_CACHE_SUPPORT__
 264         if (_dl_cache_addr != NULL && _dl_cache_addr != (caddr_t) - 1) {
 265                 int i;
 266                 header_t *header = (header_t *) _dl_cache_addr;
 267                 libentry_t *libent = (libentry_t *) & header[1];
 268                 char *strs = (char *) &libent[header->nlibs];
 269
 270                 _dl_if_debug_dprint("\tsearching cache='%s'\n", LDSO_CACHE);
 271                 for (i = 0; i < header->nlibs; i++) {
 272                         if ((libent[i].flags == LIB_ELF ||
 273                                                 libent[i].flags == LIB_ELF_LIBC0 ||
 274                                                 libent[i].flags == LIB_ELF_LIBC5) &&
 275                                         _dl_strcmp(libname, strs + libent[i].sooffset) == 0 &&
 276                                         (tpnt1 = _dl_load_elf_shared_library(secure,
 277                                                                                                                  rpnt, strs + libent[i].liboffset)))
 278                                 return tpnt1;
 279                 }
 280         }
 281 #endif
 282
 283         /* Look for libraries wherever the shared library loader
 284          * was installed */
 285         _dl_if_debug_dprint("\tsearching ldso dir='%s'\n", _dl_ldsopath);
 286         if ((tpnt1 = search_for_named_library(libname, secure, _dl_ldsopath, rpnt)) != NULL)
 287         {
 288                 return tpnt1;
 289         }
 290
 291
 292         /* Lastly, search the standard list of paths for the library.
 293            This list must exactly match the list in uClibc/ldso/util/ldd.c */
 294         _dl_if_debug_dprint("\tsearching full lib path list\n");
 295         if ((tpnt1 = search_for_named_library(libname, secure,
 296                                         UCLIBC_RUNTIME_PREFIX "lib:"
 297                                         UCLIBC_RUNTIME_PREFIX "usr/lib"
 298 #ifndef __LDSO_CACHE_SUPPORT__
 299                                         ":" UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib"
 300 #endif
 301                                         , rpnt)
 302                 ) != NULL)
 303         {
 304                 return tpnt1;
 305         }
 306
 307 goof:
 308         /* Well, we shot our wad on that one.  All we can do now is punt */
 309         if (_dl_internal_error_number)
 310                 _dl_error_number = _dl_internal_error_number;
 311         else
 312                 _dl_error_number = LD_ERROR_NOFILE;
 313         _dl_if_debug_dprint("Bummer: could not find '%s'!\n", libname);
 314         return NULL;
 315 }
 316
 317
 318 /*
 319  * Read one ELF library into memory, mmap it into the correct locations and
 320  * add the symbol info to the symbol chain.  Perform any relocations that
 321  * are required.
 322  */
 323
 324 struct elf_resolve *_dl_load_elf_shared_library(int secure,
 325         struct dyn_elf **rpnt, char *libname)
 326 {
 327         ElfW(Ehdr) *epnt;
 328         unsigned long dynamic_addr = 0;
 329         ElfW(Dyn) *dpnt;
 330         struct elf_resolve *tpnt;
 331         ElfW(Phdr) *ppnt;
 332         char *status, *header;
 333         unsigned long dynamic_info[DYNAMIC_SIZE];
 334         unsigned long *lpnt;
 335         unsigned long libaddr;
 336         unsigned long minvma = 0xffffffff, maxvma = 0;
 337         int i, flags, piclib, infile;
 338         ElfW(Addr) relro_addr = 0;
 339         size_t relro_size = 0;
 340         struct stat st;
 341
 342         libaddr = 0;
 343         infile = _dl_open(libname, O_RDONLY, 0);
 344         if (infile < 0) {
 345                 _dl_internal_error_number = LD_ERROR_NOFILE;
 346                 return NULL;
 347         }
 348
 349         if (_dl_fstat(infile, &st) < 0) {
 350                 _dl_internal_error_number = LD_ERROR_NOFILE;
 351                 _dl_close(infile);
 352                 return NULL;
 353         }
 354         /* If we are in secure mode (i.e. a setu/gid binary using LD_PRELOAD),
 355            we don't load the library if it isn't setuid. */
 356         if (secure)
 357                 if (!(st.st_mode & S_ISUID)) {
 358                         _dl_close(infile);
 359                         return NULL;
 360                 }
 361
 362         /* Check if file is already loaded */
 363         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 364                 if(tpnt->st_dev == st.st_dev && tpnt->st_ino == st.st_ino) {
 365                         /* Already loaded */
 366                         tpnt->usage_count++;
 367                         _dl_close(infile);
 368                         return tpnt;
 369                 }
 370         }
 371         header = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
 372                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 373         if (_dl_mmap_check_error(header)) {
 374                 _dl_dprintf(2, "%s: can't map '%s'\n", _dl_progname, libname);
 375                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 376                 _dl_close(infile);
 377                 return NULL;
 378         };
 379
 380         _dl_read(infile, header, _dl_pagesize);
 381         epnt = (ElfW(Ehdr) *) (intptr_t) header;
 382         if (epnt->e_ident[0] != 0x7f ||
 383                         epnt->e_ident[1] != 'E' ||
 384                         epnt->e_ident[2] != 'L' ||
 385                         epnt->e_ident[3] != 'F')
 386         {
 387                 _dl_dprintf(2, "%s: '%s' is not an ELF file\n", _dl_progname,
 388                                 libname);
 389                 _dl_internal_error_number = LD_ERROR_NOTELF;
 390                 _dl_close(infile);
 391                 _dl_munmap(header, _dl_pagesize);
 392                 return NULL;
 393         };
 394
 395         if ((epnt->e_type != ET_DYN) || (epnt->e_machine != MAGIC1
 396 #ifdef MAGIC2
 397                                 && epnt->e_machine != MAGIC2
 398 #endif
 399                                 ))
 400         {
 401                 _dl_internal_error_number =
 402                         (epnt->e_type != ET_DYN ? LD_ERROR_NOTDYN : LD_ERROR_NOTMAGIC);
 403                 _dl_dprintf(2, "%s: '%s' is not an ELF executable for " ELF_TARGET
 404                                 "\n", _dl_progname, libname);
 405                 _dl_close(infile);
 406                 _dl_munmap(header, _dl_pagesize);
 407                 return NULL;
 408         };
 409
 410         ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 411
 412         piclib = 1;
 413         for (i = 0; i < epnt->e_phnum; i++) {
 414
 415                 if (ppnt->p_type == PT_DYNAMIC) {
 416                         if (dynamic_addr)
 417                                 _dl_dprintf(2, "%s: '%s' has more than one dynamic section\n",
 418                                                 _dl_progname, libname);
 419                         dynamic_addr = ppnt->p_vaddr;
 420                 };
 421
 422                 if (ppnt->p_type == PT_LOAD) {
 423                         /* See if this is a PIC library. */
 424                         if (i == 0 && ppnt->p_vaddr > 0x1000000) {
 425                                 piclib = 0;
 426                                 minvma = ppnt->p_vaddr;
 427                         }
 428                         if (piclib && ppnt->p_vaddr < minvma) {
 429                                 minvma = ppnt->p_vaddr;
 430                         }
 431                         if (((unsigned long) ppnt->p_vaddr + ppnt->p_memsz) > maxvma) {
 432                                 maxvma = ppnt->p_vaddr + ppnt->p_memsz;
 433                         }
 434                 }
 435                 ppnt++;
 436         };
 437
 438         maxvma = (maxvma + ADDR_ALIGN) & ~ADDR_ALIGN;
 439         minvma = minvma & ~0xffffU;
 440
 441         flags = MAP_PRIVATE /*| MAP_DENYWRITE */ ;
 442         if (!piclib)
 443                 flags |= MAP_FIXED;
 444
 445         status = (char *) _dl_mmap((char *) (piclib ? 0 : minvma),
 446                         maxvma - minvma, PROT_NONE, flags | MAP_ANONYMOUS, -1, 0);
 447         if (_dl_mmap_check_error(status)) {
 448                 _dl_dprintf(2, "%s: can't map %s\n", _dl_progname, libname);
 449                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 450                 _dl_close(infile);
 451                 _dl_munmap(header, _dl_pagesize);
 452                 return NULL;
 453         };
 454         libaddr = (unsigned long) status;
 455         flags |= MAP_FIXED;
 456
 457         /* Get the memory to store the library */
 458         ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 459
 460         for (i = 0; i < epnt->e_phnum; i++) {
 461                 if (ppnt->p_type == PT_GNU_RELRO) {
 462                         relro_addr = ppnt->p_vaddr;
 463                         relro_size = ppnt->p_memsz;
 464                 }
 465                 if (ppnt->p_type == PT_LOAD) {
 466
 467                         /* See if this is a PIC library. */
 468                         if (i == 0 && ppnt->p_vaddr > 0x1000000) {
 469                                 piclib = 0;
 470                                 /* flags |= MAP_FIXED; */
 471                         }
 472
 473
 474
 475                         if (ppnt->p_flags & PF_W) {
 476                                 unsigned long map_size;
 477                                 char *cpnt;
 478
 479                                 status = (char *) _dl_mmap((char *) ((piclib ? libaddr : 0) +
 480                                                         (ppnt->p_vaddr & PAGE_ALIGN)), (ppnt->p_vaddr & ADDR_ALIGN)
 481                                                 + ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags, infile,
 482                                                 ppnt->p_offset & OFFS_ALIGN);
 483
 484                                 if (_dl_mmap_check_error(status)) {
 485                                         _dl_dprintf(2, "%s: can't map '%s'\n",
 486                                                         _dl_progname, libname);
 487                                         _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 488                                         _dl_munmap((char *) libaddr, maxvma - minvma);
 489                                         _dl_close(infile);
 490                                         _dl_munmap(header, _dl_pagesize);
 491                                         return NULL;
 492                                 };
 493
 494                                 /* Pad the last page with zeroes. */
 495                                 cpnt = (char *) (status + (ppnt->p_vaddr & ADDR_ALIGN) +
 496                                                 ppnt->p_filesz);
 497                                 while (((unsigned long) cpnt) & ADDR_ALIGN)
 498                                         *cpnt++ = 0;
 499
 500                                 /* I am not quite sure if this is completely
 501                                  * correct to do or not, but the basic way that
 502                                  * we handle bss segments is that we mmap
 503                                  * /dev/zero if there are any pages left over
 504                                  * that are not mapped as part of the file */
 505
 506                                 map_size = (ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) & PAGE_ALIGN;
 507
 508                                 if (map_size < ppnt->p_vaddr + ppnt->p_memsz)
 509                                         status = (char *) _dl_mmap((char *) map_size +
 510                                                         (piclib ? libaddr : 0),
 511                                                         ppnt->p_vaddr + ppnt->p_memsz - map_size,
 512                                                         LXFLAGS(ppnt->p_flags), flags | MAP_ANONYMOUS, -1, 0);
 513                         } else
 514                                 status = (char *) _dl_mmap((char *) (ppnt->p_vaddr & PAGE_ALIGN)
 515                                                 + (piclib ? libaddr : 0), (ppnt->p_vaddr & ADDR_ALIGN) +
 516                                                 ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags,
 517                                                 infile, ppnt->p_offset & OFFS_ALIGN);
 518                         if (_dl_mmap_check_error(status)) {
 519                                 _dl_dprintf(2, "%s: can't map '%s'\n", _dl_progname, libname);
 520                                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 521                                 _dl_munmap((char *) libaddr, maxvma - minvma);
 522                                 _dl_close(infile);
 523                                 _dl_munmap(header, _dl_pagesize);
 524                                 return NULL;
 525                         };
 526
 527                         /* if(libaddr == 0 && piclib) {
 528                            libaddr = (unsigned long) status;
 529                            flags |= MAP_FIXED;
 530                            }; */
 531                 };
 532                 ppnt++;
 533         };
 534         _dl_close(infile);
 535
 536         /* For a non-PIC library, the addresses are all absolute */
 537         if (piclib) {
 538                 dynamic_addr += (unsigned long) libaddr;
 539         }
 540
 541         /*
 542          * OK, the ELF library is now loaded into VM in the correct locations
 543          * The next step is to go through and do the dynamic linking (if needed).
 544          */
 545
 546         /* Start by scanning the dynamic section to get all of the pointers */
 547
 548         if (!dynamic_addr) {
 549                 _dl_internal_error_number = LD_ERROR_NODYNAMIC;
 550                 _dl_dprintf(2, "%s: '%s' is missing a dynamic section\n",
 551                                 _dl_progname, libname);
 552                 _dl_munmap(header, _dl_pagesize);
 553                 return NULL;
 554         }
 555
 556         dpnt = (ElfW(Dyn) *) dynamic_addr;
 557         _dl_memset(dynamic_info, 0, sizeof(dynamic_info));
 558         _dl_parse_dynamic_info(dpnt, dynamic_info, NULL, libaddr);
 559         /* If the TEXTREL is set, this means that we need to make the pages
 560            writable before we perform relocations.  Do this now. They get set
 561            back again later. */
 562
 563         if (dynamic_info[DT_TEXTREL]) {
 564 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 565                 ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 566                 for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
 567                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 568                                 _dl_mprotect((void *) ((piclib ? libaddr : 0) +
 569                                                         (ppnt->p_vaddr & PAGE_ALIGN)),
 570                                                 (ppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) ppnt->p_filesz,
 571                                                 PROT_READ | PROT_WRITE | PROT_EXEC);
 572                 }
 573 #else
 574                 _dl_dprintf(_dl_debug_file, "Can't modify %s's text section. Use GCC option -fPIC for shared objects, please.\n",libname);
 575                 _dl_exit(1);
 576 #endif
 577         }
 578
 579         tpnt = _dl_add_elf_hash_table(libname, (char *) libaddr, dynamic_info,
 580                         dynamic_addr, 0);
 581         tpnt->relro_addr = relro_addr;
 582         tpnt->relro_size = relro_size;
 583         tpnt->st_dev = st.st_dev;
 584         tpnt->st_ino = st.st_ino;
 585         tpnt->ppnt = (ElfW(Phdr) *)(intptr_t) (tpnt->loadaddr + epnt->e_phoff);
 586         tpnt->n_phent = epnt->e_phnum;
 587
 588         /*
 589          * Add this object into the symbol chain
 590          */
 591         if (*rpnt) {
 592                 (*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 593                 _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
 594                 (*rpnt)->next->prev = (*rpnt);
 595                 *rpnt = (*rpnt)->next;
 596                 (*rpnt)->dyn = tpnt;
 597                 tpnt->symbol_scope = _dl_symbol_tables;
 598         }
 599         tpnt->usage_count++;
 600         tpnt->libtype = elf_lib;
 601
 602         /*
 603          * OK, the next thing we need to do is to insert the dynamic linker into
 604          * the proper entry in the GOT so that the PLT symbols can be properly
 605          * resolved.
 606          */
 607
 608         lpnt = (unsigned long *) dynamic_info[DT_PLTGOT];
 609
 610         if (lpnt) {
 611                 lpnt = (unsigned long *) (dynamic_info[DT_PLTGOT]);
 612                 INIT_GOT(lpnt, tpnt);
 613         }
 614
 615         _dl_if_debug_dprint("\n\tfile='%s';  generating link map\n", libname);
 616         _dl_if_debug_dprint("\t\tdynamic: %x  base: %x\n", dynamic_addr, libaddr);
 617         _dl_if_debug_dprint("\t\t  entry: %x  phdr: %x  phnum: %x\n\n",
 618                         epnt->e_entry + libaddr, tpnt->ppnt, tpnt->n_phent);
 619
 620         _dl_munmap(header, _dl_pagesize);
 621
 622         return tpnt;
 623 }
 624
 625 /* now_flag must be RTLD_NOW or zero */
 626 int _dl_fixup(struct dyn_elf *rpnt, int now_flag)
 627 {
 628         int goof = 0;
 629         struct elf_resolve *tpnt;
 630         ElfW(Word) reloc_size, relative_count;
 631         ElfW(Addr) reloc_addr;
 632
 633         if (rpnt->next)
 634                 goof = _dl_fixup(rpnt->next, now_flag);
 635         if (goof)
 636                 return goof;
 637         tpnt = rpnt->dyn;
 638
 639         if(!(tpnt->init_flag & RELOCS_DONE))
 640                 _dl_if_debug_dprint("relocation processing: %s\n", tpnt->libname);
 641
 642         if (unlikely(tpnt->dynamic_info[UNSUPPORTED_RELOC_TYPE])) {
 643                 _dl_if_debug_dprint("%s: can't handle %s relocation records\n",
 644                                 _dl_progname, UNSUPPORTED_RELOC_STR);
 645                 goof++;
 646                 return goof;
 647         }
 648
 649         reloc_size = tpnt->dynamic_info[DT_RELOC_TABLE_SIZE];
 650 /* On some machines, notably SPARC & PPC, DT_REL* includes DT_JMPREL in its
 651    range.  Note that according to the ELF spec, this is completely legal! */
 652 #ifdef ELF_MACHINE_PLTREL_OVERLAP
 653         reloc_size -= tpnt->dynamic_info [DT_PLTRELSZ];
 654 #endif
 655         if (tpnt->dynamic_info[DT_RELOC_TABLE_ADDR] &&
 656             !(tpnt->init_flag & RELOCS_DONE)) {
 657                 reloc_addr = tpnt->dynamic_info[DT_RELOC_TABLE_ADDR];
 658                 relative_count = tpnt->dynamic_info[DT_RELCONT_IDX];
 659                 if (relative_count) { /* Optimize the XX_RELATIVE relocations if possible */
 660                         reloc_size -= relative_count * sizeof(ELF_RELOC);
 661                         elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count);
 662                         reloc_addr += relative_count * sizeof(ELF_RELOC);
 663                 }
 664                 goof += _dl_parse_relocation_information(rpnt,
 665                                 reloc_addr,
 666                                 reloc_size);
 667                 tpnt->init_flag |= RELOCS_DONE;
 668         }
 669         if (tpnt->dynamic_info[DT_BIND_NOW])
 670                 now_flag = RTLD_NOW;
 671         if (tpnt->dynamic_info[DT_JMPREL] &&
 672             (!(tpnt->init_flag & JMP_RELOCS_DONE) ||
 673              (now_flag && !(tpnt->rtld_flags & now_flag)))) {
 674                 tpnt->rtld_flags |= now_flag;
 675                 if (!(tpnt->rtld_flags & RTLD_NOW)) {
 676                         _dl_parse_lazy_relocation_information(rpnt,
 677                                         tpnt->dynamic_info[DT_JMPREL],
 678                                         tpnt->dynamic_info [DT_PLTRELSZ]);
 679                 } else {
 680                         goof += _dl_parse_relocation_information(rpnt,
 681                                         tpnt->dynamic_info[DT_JMPREL],
 682                                         tpnt->dynamic_info[DT_PLTRELSZ]);
 683                 }
 684                 tpnt->init_flag |= JMP_RELOCS_DONE;
 685         }
 686         return goof;
 687 }
 688
 689 /* Minimal printf which handles only %s, %d, and %x */
 690 void _dl_dprintf(int fd, const char *fmt, ...)
 691 {
 692 #if __WORDSIZE > 32
 693         long int num;
 694 #else
 695         int num;
 696 #endif
 697         va_list args;
 698         char *start, *ptr, *string;
 699         static char *buf;
 700
 701         if (!fmt)
 702                 return;
 703
 704         buf = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
 705                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 706         if (_dl_mmap_check_error(buf)) {
 707                 _dl_write(fd, "mmap of a spare page failed!\n", 29);
 708                 _dl_exit(20);
 709         }
 710
 711         start = ptr = buf;
 712
 713         if (_dl_strlen(fmt) >= (_dl_pagesize - 1)) {
 714                 _dl_write(fd, "overflow\n", 11);
 715                 _dl_exit(20);
 716         }
 717
 718         _dl_strcpy(buf, fmt);
 719         va_start(args, fmt);
 720
 721         while (start) {
 722                 while (*ptr != '%' && *ptr) {
 723                         ptr++;
 724                 }
 725
 726                 if (*ptr == '%') {
 727                         *ptr++ = '\0';
 728                         _dl_write(fd, start, _dl_strlen(start));
 729
 730                         switch (*ptr++) {
 731                                 case 's':
 732                                         string = va_arg(args, char *);
 733
 734                                         if (!string)
 735                                                 _dl_write(fd, "(null)", 6);
 736                                         else
 737                                                 _dl_write(fd, string, _dl_strlen(string));
 738                                         break;
 739
 740                                 case 'i':
 741                                 case 'd':
 742                                         {
 743                                                 char tmp[22];
 744 #if __WORDSIZE > 32
 745                                                 num = va_arg(args, long int);
 746 #else
 747                                                 num = va_arg(args, int);
 748 #endif
 749                                                 string = _dl_simple_ltoa(tmp, num);
 750                                                 _dl_write(fd, string, _dl_strlen(string));
 751                                                 break;
 752                                         }
 753                                 case 'x':
 754                                 case 'X':
 755                                         {
 756                                                 char tmp[22];
 757 #if __WORDSIZE > 32
 758                                                 num = va_arg(args, long int);
 759 #else
 760                                                 num = va_arg(args, int);
 761 #endif
 762                                                 string = _dl_simple_ltoahex(tmp, num);
 763                                                 _dl_write(fd, string, _dl_strlen(string));
 764                                                 break;
 765                                         }
 766                                 default:
 767                                         _dl_write(fd, "(null)", 6);
 768                                         break;
 769                         }
 770
 771                         start = ptr;
 772                 } else {
 773                         _dl_write(fd, start, _dl_strlen(start));
 774                         start = NULL;
 775                 }
 776         }
 777         _dl_munmap(buf, _dl_pagesize);
 778         return;
 779 }
 780
 781 char *_dl_strdup(const char *string)
 782 {
 783         char *retval;
 784         int len;
 785
 786         len = _dl_strlen(string);
 787         retval = _dl_malloc(len + 1);
 788         _dl_strcpy(retval, string);
 789         return retval;
 790 }
 791
 792 void _dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info[], void *debug_addr, ElfW(Addr) load_off)
 793 {
 794         __dl_parse_dynamic_info(dpnt, dynamic_info, debug_addr, load_off);
 795 }
 796
 797 /* we want this in ldso.so and libdl.a but nowhere else */
 798 #ifdef __USE_GNU
 799 #if defined IS_IN_rtld || (defined IS_IN_libdl && ! defined SHARED)
 800 int
 801 __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, size_t size, void *data), void *data)
 802 {
 803         struct elf_resolve *l;
 804         struct dl_phdr_info info;
 805         int ret = 0;
 806
 807         for (l = _dl_loaded_modules; l != NULL; l = l->next) {
 808                 info.dlpi_addr = l->loadaddr;
 809                 info.dlpi_name = l->libname;
 810                 info.dlpi_phdr = l->ppnt;
 811                 info.dlpi_phnum = l->n_phent;
 812                 ret = callback (&info, sizeof (struct dl_phdr_info), data);
 813                 if (ret)
 814                         break;
 815         }
 816         return ret;
 817 }
 818 strong_alias(__dl_iterate_phdr, dl_iterate_phdr)
 819 #endif
 820 #endif