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) 2000-2006 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:%i: can't map '%s'\n",
  64                                 _dl_progname, __LINE__, 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, *mylibname;
 140         struct elf_resolve *tpnt;
 141         int done;
 142
 143         if (path_list==NULL)
 144                 return NULL;
 145
 146         /* We need a writable copy of this string, but we don't
 147          * need this allocated permanently since we don't want
 148          * to leak memory, so use alloca to put path on the stack */
 149         done = _dl_strlen(path_list);
 150         path = alloca(done + 1);
 151
 152         /* another bit of local storage */
 153         mylibname = alloca(2050);
 154
 155         /* gcc inlines alloca using a single instruction adjusting
 156          * the stack pointer and no stack overflow check and thus
 157          * no NULL error return.  No point leaving in dead code... */
 158 #if 0
 159         if (!path || !mylibname) {
 160                 _dl_dprintf(2, "Out of memory!\n");
 161                 _dl_exit(0);
 162         }
 163 #endif
 164
 165         _dl_memcpy(path, path_list, done);
 166
 167         /* Unlike ldd.c, don't bother to eliminate double //s */
 168
 169         /* Replace colons with zeros in path_list */
 170         /* : at the beginning or end of path maps to CWD */
 171         /* :: anywhere maps CWD */
 172         /* "" maps to CWD */
 173         done = 0;
 174         path_n = path;
 175         do {
 176                 if (*path == 0) {
 177                         *path = ':';
 178                         done = 1;
 179                 }
 180                 if (*path == ':') {
 181                         *path = 0;
 182                         if (*path_n)
 183                                 _dl_strcpy(mylibname, path_n);
 184                         else
 185                                 _dl_strcpy(mylibname, "."); /* Assume current dir if empty path */
 186                         _dl_strcat(mylibname, "/");
 187                         _dl_strcat(mylibname, name);
 188                         if ((tpnt = _dl_load_elf_shared_library(secure, rpnt, mylibname)) != NULL)
 189                                 return tpnt;
 190                         path_n = path+1;
 191                 }
 192                 path++;
 193         } while (!done);
 194         return NULL;
 195 }
 196
 197 /* Used to return error codes back to dlopen et. al.  */
 198 unsigned long _dl_error_number;
 199 unsigned long _dl_internal_error_number;
 200
 201 struct elf_resolve *_dl_load_shared_library(int secure, struct dyn_elf **rpnt,
 202         struct elf_resolve *tpnt, char *full_libname, int __attribute__((unused)) trace_loaded_objects)
 203 {
 204         char *pnt;
 205         struct elf_resolve *tpnt1;
 206         char *libname;
 207
 208         _dl_internal_error_number = 0;
 209         libname = full_libname;
 210
 211         /* quick hack to ensure mylibname buffer doesn't overflow.  don't
 212            allow full_libname or any directory to be longer than 1024. */
 213         if (_dl_strlen(full_libname) > 1024)
 214                 goto goof;
 215
 216         /* Skip over any initial initial './' and '/' stuff to
 217          * get the short form libname with no path garbage */
 218         pnt = _dl_strrchr(libname, '/');
 219         if (pnt) {
 220                 libname = pnt + 1;
 221         }
 222
 223         _dl_if_debug_dprint("\tfind library='%s'; searching\n", libname);
 224         /* If the filename has any '/', try it straight and leave it at that.
 225            For IBCS2 compatibility under linux, we substitute the string
 226            /usr/i486-sysv4/lib for /usr/lib in library names. */
 227
 228         if (libname != full_libname) {
 229                 _dl_if_debug_dprint("\ttrying file='%s'\n", full_libname);
 230                 tpnt1 = _dl_load_elf_shared_library(secure, rpnt, full_libname);
 231                 if (tpnt1) {
 232                         return tpnt1;
 233                 }
 234         }
 235
 236         /*
 237          * The ABI specifies that RPATH is searched before LD_LIBRARY_PATH or
 238          * the default path of /usr/lib.  Check in rpath directories.
 239          */
 240 #ifdef __LDSO_RUNPATH__
 241         pnt = (tpnt ? (char *) tpnt->dynamic_info[DT_RPATH] : NULL);
 242         if (pnt) {
 243                 pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
 244                 _dl_if_debug_dprint("\tsearching RPATH='%s'\n", pnt);
 245                 if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL)
 246                         return tpnt1;
 247         }
 248 #endif
 249
 250         /* Check in LD_{ELF_}LIBRARY_PATH, if specified and allowed */
 251         if (_dl_library_path) {
 252                 _dl_if_debug_dprint("\tsearching LD_LIBRARY_PATH='%s'\n", _dl_library_path);
 253                 if ((tpnt1 = search_for_named_library(libname, secure, _dl_library_path, rpnt)) != NULL)
 254                 {
 255                         return tpnt1;
 256                 }
 257         }
 258
 259         /*
 260          * The ABI specifies that RUNPATH is searched after LD_LIBRARY_PATH.
 261          */
 262 #ifdef __LDSO_RUNPATH__
 263         pnt = (tpnt ? (char *)tpnt->dynamic_info[DT_RUNPATH] : NULL);
 264         if (pnt) {
 265                 pnt += (unsigned long) tpnt->dynamic_info[DT_STRTAB];
 266                 _dl_if_debug_dprint("\tsearching RUNPATH='%s'\n", pnt);
 267                 if ((tpnt1 = search_for_named_library(libname, secure, pnt, rpnt)) != NULL)
 268                         return tpnt1;
 269         }
 270 #endif
 271
 272         /*
 273          * Where should the cache be searched?  There is no such concept in the
 274          * ABI, so we have some flexibility here.  For now, search it before
 275          * the hard coded paths that follow (i.e before /lib and /usr/lib).
 276          */
 277 #ifdef __LDSO_CACHE_SUPPORT__
 278         if (_dl_cache_addr != NULL && _dl_cache_addr != (caddr_t) - 1) {
 279                 int i;
 280                 header_t *header = (header_t *) _dl_cache_addr;
 281                 libentry_t *libent = (libentry_t *) & header[1];
 282                 char *strs = (char *) &libent[header->nlibs];
 283
 284                 _dl_if_debug_dprint("\tsearching cache='%s'\n", LDSO_CACHE);
 285                 for (i = 0; i < header->nlibs; i++) {
 286                         if ((libent[i].flags == LIB_ELF ||
 287                                                 libent[i].flags == LIB_ELF_LIBC0 ||
 288                                                 libent[i].flags == LIB_ELF_LIBC5) &&
 289                                         _dl_strcmp(libname, strs + libent[i].sooffset) == 0 &&
 290                                         (tpnt1 = _dl_load_elf_shared_library(secure,
 291                                                                                                                  rpnt, strs + libent[i].liboffset)))
 292                                 return tpnt1;
 293                 }
 294         }
 295 #endif
 296
 297         /* Look for libraries wherever the shared library loader
 298          * was installed */
 299         _dl_if_debug_dprint("\tsearching ldso dir='%s'\n", _dl_ldsopath);
 300         if ((tpnt1 = search_for_named_library(libname, secure, _dl_ldsopath, rpnt)) != NULL)
 301         {
 302                 return tpnt1;
 303         }
 304
 305
 306         /* Lastly, search the standard list of paths for the library.
 307            This list must exactly match the list in uClibc/ldso/util/ldd.c */
 308         _dl_if_debug_dprint("\tsearching full lib path list\n");
 309         if ((tpnt1 = search_for_named_library(libname, secure,
 310                                         UCLIBC_RUNTIME_PREFIX "lib:"
 311                                         UCLIBC_RUNTIME_PREFIX "usr/lib"
 312 #ifndef __LDSO_CACHE_SUPPORT__
 313                                         ":" UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib"
 314 #endif
 315                                         , rpnt)
 316                 ) != NULL)
 317         {
 318                 return tpnt1;
 319         }
 320
 321 goof:
 322         /* Well, we shot our wad on that one.  All we can do now is punt */
 323         if (_dl_internal_error_number)
 324                 _dl_error_number = _dl_internal_error_number;
 325         else
 326                 _dl_error_number = LD_ERROR_NOFILE;
 327         _dl_if_debug_dprint("Bummer: could not find '%s'!\n", libname);
 328         return NULL;
 329 }
 330
 331
 332 /*
 333  * Read one ELF library into memory, mmap it into the correct locations and
 334  * add the symbol info to the symbol chain.  Perform any relocations that
 335  * are required.
 336  */
 337
 338 struct elf_resolve *_dl_load_elf_shared_library(int secure,
 339         struct dyn_elf **rpnt, char *libname)
 340 {
 341         ElfW(Ehdr) *epnt;
 342         unsigned long dynamic_addr = 0;
 343         ElfW(Dyn) *dpnt;
 344         struct elf_resolve *tpnt;
 345         ElfW(Phdr) *ppnt;
 346         char *status, *header;
 347         unsigned long dynamic_info[DYNAMIC_SIZE];
 348         unsigned long *lpnt;
 349         unsigned long libaddr;
 350         unsigned long minvma = 0xffffffff, maxvma = 0;
 351         int i, flags, piclib, infile;
 352         ElfW(Addr) relro_addr = 0;
 353         size_t relro_size = 0;
 354         struct stat st;
 355
 356         libaddr = 0;
 357         infile = _dl_open(libname, O_RDONLY, 0);
 358         if (infile < 0) {
 359                 _dl_internal_error_number = LD_ERROR_NOFILE;
 360                 return NULL;
 361         }
 362
 363         if (_dl_fstat(infile, &st) < 0) {
 364                 _dl_internal_error_number = LD_ERROR_NOFILE;
 365                 _dl_close(infile);
 366                 return NULL;
 367         }
 368         /* If we are in secure mode (i.e. a setu/gid binary using LD_PRELOAD),
 369            we don't load the library if it isn't setuid. */
 370         if (secure)
 371                 if (!(st.st_mode & S_ISUID)) {
 372                         _dl_close(infile);
 373                         return NULL;
 374                 }
 375
 376         /* Check if file is already loaded */
 377         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 378                 if(tpnt->st_dev == st.st_dev && tpnt->st_ino == st.st_ino) {
 379                         /* Already loaded */
 380                         tpnt->usage_count++;
 381                         _dl_close(infile);
 382                         return tpnt;
 383                 }
 384         }
 385         header = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
 386                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 387         if (_dl_mmap_check_error(header)) {
 388                 _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
 389                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 390                 _dl_close(infile);
 391                 return NULL;
 392         }
 393
 394         _dl_read(infile, header, _dl_pagesize);
 395         epnt = (ElfW(Ehdr) *) (intptr_t) header;
 396         if (epnt->e_ident[0] != 0x7f ||
 397                         epnt->e_ident[1] != 'E' ||
 398                         epnt->e_ident[2] != 'L' ||
 399                         epnt->e_ident[3] != 'F')
 400         {
 401                 _dl_dprintf(2, "%s: '%s' is not an ELF file\n", _dl_progname,
 402                                 libname);
 403                 _dl_internal_error_number = LD_ERROR_NOTELF;
 404                 _dl_close(infile);
 405                 _dl_munmap(header, _dl_pagesize);
 406                 return NULL;
 407         }
 408
 409         if ((epnt->e_type != ET_DYN) || (epnt->e_machine != MAGIC1
 410 #ifdef MAGIC2
 411                                 && epnt->e_machine != MAGIC2
 412 #endif
 413                                 ))
 414         {
 415                 _dl_internal_error_number =
 416                         (epnt->e_type != ET_DYN ? LD_ERROR_NOTDYN : LD_ERROR_NOTMAGIC);
 417                 _dl_dprintf(2, "%s: '%s' is not an ELF executable for " ELF_TARGET
 418                                 "\n", _dl_progname, libname);
 419                 _dl_close(infile);
 420                 _dl_munmap(header, _dl_pagesize);
 421                 return NULL;
 422         }
 423
 424         ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 425
 426         piclib = 1;
 427         for (i = 0; i < epnt->e_phnum; i++) {
 428
 429                 if (ppnt->p_type == PT_DYNAMIC) {
 430                         if (dynamic_addr)
 431                                 _dl_dprintf(2, "%s: '%s' has more than one dynamic section\n",
 432                                                 _dl_progname, libname);
 433                         dynamic_addr = ppnt->p_vaddr;
 434                 }
 435
 436                 if (ppnt->p_type == PT_LOAD) {
 437                         /* See if this is a PIC library. */
 438                         if (i == 0 && ppnt->p_vaddr > 0x1000000) {
 439                                 piclib = 0;
 440                                 minvma = ppnt->p_vaddr;
 441                         }
 442                         if (piclib && ppnt->p_vaddr < minvma) {
 443                                 minvma = ppnt->p_vaddr;
 444                         }
 445                         if (((unsigned long) ppnt->p_vaddr + ppnt->p_memsz) > maxvma) {
 446                                 maxvma = ppnt->p_vaddr + ppnt->p_memsz;
 447                         }
 448                 }
 449                 ppnt++;
 450         }
 451
 452         maxvma = (maxvma + ADDR_ALIGN) & ~ADDR_ALIGN;
 453         minvma = minvma & ~0xffffU;
 454
 455         flags = MAP_PRIVATE /*| MAP_DENYWRITE */ ;
 456         if (!piclib)
 457                 flags |= MAP_FIXED;
 458
 459         status = (char *) _dl_mmap((char *) (piclib ? 0 : minvma),
 460                         maxvma - minvma, PROT_NONE, flags | MAP_ANONYMOUS, -1, 0);
 461         if (_dl_mmap_check_error(status)) {
 462                 _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
 463                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 464                 _dl_close(infile);
 465                 _dl_munmap(header, _dl_pagesize);
 466                 return NULL;
 467         }
 468         libaddr = (unsigned long) status;
 469         flags |= MAP_FIXED;
 470
 471         /* Get the memory to store the library */
 472         ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 473
 474         for (i = 0; i < epnt->e_phnum; i++) {
 475                 if (ppnt->p_type == PT_GNU_RELRO) {
 476                         relro_addr = ppnt->p_vaddr;
 477                         relro_size = ppnt->p_memsz;
 478                 }
 479                 if (ppnt->p_type == PT_LOAD) {
 480
 481                         /* See if this is a PIC library. */
 482                         if (i == 0 && ppnt->p_vaddr > 0x1000000) {
 483                                 piclib = 0;
 484                                 /* flags |= MAP_FIXED; */
 485                         }
 486
 487
 488
 489                         if (ppnt->p_flags & PF_W) {
 490                                 unsigned long map_size;
 491                                 char *cpnt;
 492
 493                                 status = (char *) _dl_mmap((char *) ((piclib ? libaddr : 0) +
 494                                                         (ppnt->p_vaddr & PAGE_ALIGN)), (ppnt->p_vaddr & ADDR_ALIGN)
 495                                                 + ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags, infile,
 496                                                 ppnt->p_offset & OFFS_ALIGN);
 497
 498                                 if (_dl_mmap_check_error(status)) {
 499                                         _dl_dprintf(2, "%s:%i: can't map '%s'\n",
 500                                                         _dl_progname, __LINE__, libname);
 501                                         _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 502                                         _dl_munmap((char *) libaddr, maxvma - minvma);
 503                                         _dl_close(infile);
 504                                         _dl_munmap(header, _dl_pagesize);
 505                                         return NULL;
 506                                 }
 507
 508                                 /* Pad the last page with zeroes. */
 509                                 cpnt = (char *) (status + (ppnt->p_vaddr & ADDR_ALIGN) +
 510                                                 ppnt->p_filesz);
 511                                 while (((unsigned long) cpnt) & ADDR_ALIGN)
 512                                         *cpnt++ = 0;
 513
 514                                 /* I am not quite sure if this is completely
 515                                  * correct to do or not, but the basic way that
 516                                  * we handle bss segments is that we mmap
 517                                  * /dev/zero if there are any pages left over
 518                                  * that are not mapped as part of the file */
 519
 520                                 map_size = (ppnt->p_vaddr + ppnt->p_filesz + ADDR_ALIGN) & PAGE_ALIGN;
 521
 522                                 if (map_size < ppnt->p_vaddr + ppnt->p_memsz)
 523                                         status = (char *) _dl_mmap((char *) map_size +
 524                                                         (piclib ? libaddr : 0),
 525                                                         ppnt->p_vaddr + ppnt->p_memsz - map_size,
 526                                                         LXFLAGS(ppnt->p_flags), flags | MAP_ANONYMOUS, -1, 0);
 527                         } else
 528                                 status = (char *) _dl_mmap((char *) (ppnt->p_vaddr & PAGE_ALIGN)
 529                                                 + (piclib ? libaddr : 0), (ppnt->p_vaddr & ADDR_ALIGN) +
 530                                                 ppnt->p_filesz, LXFLAGS(ppnt->p_flags), flags,
 531                                                 infile, ppnt->p_offset & OFFS_ALIGN);
 532                         if (_dl_mmap_check_error(status)) {
 533                                 _dl_dprintf(2, "%s:%i: can't map '%s'\n", _dl_progname, __LINE__, libname);
 534                                 _dl_internal_error_number = LD_ERROR_MMAP_FAILED;
 535                                 _dl_munmap((char *) libaddr, maxvma - minvma);
 536                                 _dl_close(infile);
 537                                 _dl_munmap(header, _dl_pagesize);
 538                                 return NULL;
 539                         }
 540
 541                         /* if(libaddr == 0 && piclib) {
 542                            libaddr = (unsigned long) status;
 543                            flags |= MAP_FIXED;
 544                            } */
 545                 }
 546                 ppnt++;
 547         }
 548         _dl_close(infile);
 549
 550         /* For a non-PIC library, the addresses are all absolute */
 551         if (piclib) {
 552                 dynamic_addr += (unsigned long) libaddr;
 553         }
 554
 555         /*
 556          * OK, the ELF library is now loaded into VM in the correct locations
 557          * The next step is to go through and do the dynamic linking (if needed).
 558          */
 559
 560         /* Start by scanning the dynamic section to get all of the pointers */
 561
 562         if (!dynamic_addr) {
 563                 _dl_internal_error_number = LD_ERROR_NODYNAMIC;
 564                 _dl_dprintf(2, "%s: '%s' is missing a dynamic section\n",
 565                                 _dl_progname, libname);
 566                 _dl_munmap(header, _dl_pagesize);
 567                 return NULL;
 568         }
 569
 570         dpnt = (ElfW(Dyn) *) dynamic_addr;
 571         _dl_memset(dynamic_info, 0, sizeof(dynamic_info));
 572         _dl_parse_dynamic_info(dpnt, dynamic_info, NULL, libaddr);
 573         /* If the TEXTREL is set, this means that we need to make the pages
 574            writable before we perform relocations.  Do this now. They get set
 575            back again later. */
 576
 577         if (dynamic_info[DT_TEXTREL]) {
 578 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 579                 ppnt = (ElfW(Phdr) *)(intptr_t) & header[epnt->e_phoff];
 580                 for (i = 0; i < epnt->e_phnum; i++, ppnt++) {
 581                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 582                                 _dl_mprotect((void *) ((piclib ? libaddr : 0) +
 583                                                         (ppnt->p_vaddr & PAGE_ALIGN)),
 584                                                 (ppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) ppnt->p_filesz,
 585                                                 PROT_READ | PROT_WRITE | PROT_EXEC);
 586                 }
 587 #else
 588                 _dl_dprintf(_dl_debug_file, "Can't modify %s's text section. Use GCC option -fPIC for shared objects, please.\n",libname);
 589                 _dl_exit(1);
 590 #endif
 591         }
 592
 593         tpnt = _dl_add_elf_hash_table(libname, (char *) libaddr, dynamic_info,
 594                         dynamic_addr, 0);
 595         tpnt->relro_addr = relro_addr;
 596         tpnt->relro_size = relro_size;
 597         tpnt->st_dev = st.st_dev;
 598         tpnt->st_ino = st.st_ino;
 599         tpnt->ppnt = (ElfW(Phdr) *)(intptr_t) (tpnt->loadaddr + epnt->e_phoff);
 600         tpnt->n_phent = epnt->e_phnum;
 601
 602         /*
 603          * Add this object into the symbol chain
 604          */
 605         if (*rpnt) {
 606                 (*rpnt)->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 607                 _dl_memset((*rpnt)->next, 0, sizeof(struct dyn_elf));
 608                 (*rpnt)->next->prev = (*rpnt);
 609                 *rpnt = (*rpnt)->next;
 610                 (*rpnt)->dyn = tpnt;
 611                 tpnt->symbol_scope = _dl_symbol_tables;
 612         }
 613         tpnt->usage_count++;
 614         tpnt->libtype = elf_lib;
 615
 616         /*
 617          * OK, the next thing we need to do is to insert the dynamic linker into
 618          * the proper entry in the GOT so that the PLT symbols can be properly
 619          * resolved.
 620          */
 621
 622         lpnt = (unsigned long *) dynamic_info[DT_PLTGOT];
 623
 624         if (lpnt) {
 625                 lpnt = (unsigned long *) (dynamic_info[DT_PLTGOT]);
 626                 INIT_GOT(lpnt, tpnt);
 627         }
 628
 629         _dl_if_debug_dprint("\n\tfile='%s';  generating link map\n", libname);
 630         _dl_if_debug_dprint("\t\tdynamic: %x  base: %x\n", dynamic_addr, libaddr);
 631         _dl_if_debug_dprint("\t\t  entry: %x  phdr: %x  phnum: %x\n\n",
 632                         epnt->e_entry + libaddr, tpnt->ppnt, tpnt->n_phent);
 633
 634         _dl_munmap(header, _dl_pagesize);
 635
 636         return tpnt;
 637 }
 638
 639 /* now_flag must be RTLD_NOW or zero */
 640 int _dl_fixup(struct dyn_elf *rpnt, int now_flag)
 641 {
 642         int goof = 0;
 643         struct elf_resolve *tpnt;
 644         ElfW(Word) reloc_size, relative_count;
 645         ElfW(Addr) reloc_addr;
 646
 647         if (rpnt->next)
 648                 goof = _dl_fixup(rpnt->next, now_flag);
 649         if (goof)
 650                 return goof;
 651         tpnt = rpnt->dyn;
 652
 653         if(!(tpnt->init_flag & RELOCS_DONE))
 654                 _dl_if_debug_dprint("relocation processing: %s\n", tpnt->libname);
 655
 656         if (unlikely(tpnt->dynamic_info[UNSUPPORTED_RELOC_TYPE])) {
 657                 _dl_if_debug_dprint("%s: can't handle %s relocation records\n",
 658                                 _dl_progname, UNSUPPORTED_RELOC_STR);
 659                 goof++;
 660                 return goof;
 661         }
 662
 663         reloc_size = tpnt->dynamic_info[DT_RELOC_TABLE_SIZE];
 664 /* On some machines, notably SPARC & PPC, DT_REL* includes DT_JMPREL in its
 665    range.  Note that according to the ELF spec, this is completely legal! */
 666 #ifdef ELF_MACHINE_PLTREL_OVERLAP
 667         reloc_size -= tpnt->dynamic_info [DT_PLTRELSZ];
 668 #endif
 669         if (tpnt->dynamic_info[DT_RELOC_TABLE_ADDR] &&
 670             !(tpnt->init_flag & RELOCS_DONE)) {
 671                 reloc_addr = tpnt->dynamic_info[DT_RELOC_TABLE_ADDR];
 672                 relative_count = tpnt->dynamic_info[DT_RELCONT_IDX];
 673                 if (relative_count) { /* Optimize the XX_RELATIVE relocations if possible */
 674                         reloc_size -= relative_count * sizeof(ELF_RELOC);
 675                         elf_machine_relative(tpnt->loadaddr, reloc_addr, relative_count);
 676                         reloc_addr += relative_count * sizeof(ELF_RELOC);
 677                 }
 678                 goof += _dl_parse_relocation_information(rpnt,
 679                                 reloc_addr,
 680                                 reloc_size);
 681                 tpnt->init_flag |= RELOCS_DONE;
 682         }
 683         if (tpnt->dynamic_info[DT_BIND_NOW])
 684                 now_flag = RTLD_NOW;
 685         if (tpnt->dynamic_info[DT_JMPREL] &&
 686             (!(tpnt->init_flag & JMP_RELOCS_DONE) ||
 687              (now_flag && !(tpnt->rtld_flags & now_flag)))) {
 688                 tpnt->rtld_flags |= now_flag;
 689                 if (!(tpnt->rtld_flags & RTLD_NOW)) {
 690                         _dl_parse_lazy_relocation_information(rpnt,
 691                                         tpnt->dynamic_info[DT_JMPREL],
 692                                         tpnt->dynamic_info [DT_PLTRELSZ]);
 693                 } else {
 694                         goof += _dl_parse_relocation_information(rpnt,
 695                                         tpnt->dynamic_info[DT_JMPREL],
 696                                         tpnt->dynamic_info[DT_PLTRELSZ]);
 697                 }
 698                 tpnt->init_flag |= JMP_RELOCS_DONE;
 699         }
 700         return goof;
 701 }
 702
 703 /* Minimal printf which handles only %s, %d, and %x */
 704 void _dl_dprintf(int fd, const char *fmt, ...)
 705 {
 706 #if __WORDSIZE > 32
 707         long int num;
 708 #else
 709         int num;
 710 #endif
 711         va_list args;
 712         char *start, *ptr, *string;
 713         static char *buf;
 714
 715         if (!fmt)
 716                 return;
 717
 718         buf = _dl_mmap((void *) 0, _dl_pagesize, PROT_READ | PROT_WRITE,
 719                         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 720         if (_dl_mmap_check_error(buf)) {
 721                 _dl_write(fd, "mmap of a spare page failed!\n", 29);
 722                 _dl_exit(20);
 723         }
 724
 725         start = ptr = buf;
 726
 727         if (_dl_strlen(fmt) >= (_dl_pagesize - 1)) {
 728                 _dl_write(fd, "overflow\n", 11);
 729                 _dl_exit(20);
 730         }
 731
 732         _dl_strcpy(buf, fmt);
 733         va_start(args, fmt);
 734
 735         while (start) {
 736                 while (*ptr != '%' && *ptr) {
 737                         ptr++;
 738                 }
 739
 740                 if (*ptr == '%') {
 741                         *ptr++ = '\0';
 742                         _dl_write(fd, start, _dl_strlen(start));
 743
 744                         switch (*ptr++) {
 745                                 case 's':
 746                                         string = va_arg(args, char *);
 747
 748                                         if (!string)
 749                                                 _dl_write(fd, "(null)", 6);
 750                                         else
 751                                                 _dl_write(fd, string, _dl_strlen(string));
 752                                         break;
 753
 754                                 case 'i':
 755                                 case 'd':
 756                                         {
 757                                                 char tmp[22];
 758 #if __WORDSIZE > 32
 759                                                 num = va_arg(args, long int);
 760 #else
 761                                                 num = va_arg(args, int);
 762 #endif
 763                                                 string = _dl_simple_ltoa(tmp, num);
 764                                                 _dl_write(fd, string, _dl_strlen(string));
 765                                                 break;
 766                                         }
 767                                 case 'x':
 768                                 case 'X':
 769                                         {
 770                                                 char tmp[22];
 771 #if __WORDSIZE > 32
 772                                                 num = va_arg(args, long int);
 773 #else
 774                                                 num = va_arg(args, int);
 775 #endif
 776                                                 string = _dl_simple_ltoahex(tmp, num);
 777                                                 _dl_write(fd, string, _dl_strlen(string));
 778                                                 break;
 779                                         }
 780                                 default:
 781                                         _dl_write(fd, "(null)", 6);
 782                                         break;
 783                         }
 784
 785                         start = ptr;
 786                 } else {
 787                         _dl_write(fd, start, _dl_strlen(start));
 788                         start = NULL;
 789                 }
 790         }
 791         _dl_munmap(buf, _dl_pagesize);
 792         return;
 793 }
 794
 795 char *_dl_strdup(const char *string)
 796 {
 797         char *retval;
 798         int len;
 799
 800         len = _dl_strlen(string);
 801         retval = _dl_malloc(len + 1);
 802         _dl_strcpy(retval, string);
 803         return retval;
 804 }
 805
 806 void _dl_parse_dynamic_info(ElfW(Dyn) *dpnt, unsigned long dynamic_info[], void *debug_addr, ElfW(Addr) load_off)
 807 {
 808         __dl_parse_dynamic_info(dpnt, dynamic_info, debug_addr, load_off);
 809 }
 810
 811 /* we want this in ldso.so and libdl.a but nowhere else */
 812 #ifdef __USE_GNU
 813 #if defined IS_IN_rtld || (defined IS_IN_libdl && ! defined SHARED)
 814 extern __typeof(dl_iterate_phdr) __dl_iterate_phdr;
 815 int
 816 __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info, size_t size, void *data), void *data)
 817 {
 818         struct elf_resolve *l;
 819         struct dl_phdr_info info;
 820         int ret = 0;
 821
 822         for (l = _dl_loaded_modules; l != NULL; l = l->next) {
 823                 info.dlpi_addr = l->loadaddr;
 824                 info.dlpi_name = l->libname;
 825                 info.dlpi_phdr = l->ppnt;
 826                 info.dlpi_phnum = l->n_phent;
 827                 ret = callback (&info, sizeof (struct dl_phdr_info), data);
 828                 if (ret)
 829                         break;
 830         }
 831         return ret;
 832 }
 833 strong_alias(__dl_iterate_phdr, dl_iterate_phdr)
 834 #endif
 835 #endif