elf/cache.c

   1 /* Copyright (C) 1999,2000,2001,2002,2003,2005
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Andreas Jaeger <aj@suse.de>, 1999.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <error.h>
  23 #include <dirent.h>
  24 #include <inttypes.h>
  25 #include <libintl.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <sys/fcntl.h>
  31 #include <sys/mman.h>
  32 #include <sys/stat.h>
  33 #include <sys/types.h>
  34
  35 #include "ldconfig.h"
  36 #include "dl-cache.h"
  37
  38 struct cache_entry
  39 {
  40   char *lib;                    /* Library name.  */
  41   char *path;                   /* Path to find library.  */
  42   int flags;                    /* Flags to indicate kind of library.  */
  43   unsigned int osversion;       /* Required OS version.  */
  44   uint64_t hwcap;               /* Important hardware capabilities.  */
  45   int bits_hwcap;               /* Number of bits set in hwcap.  */
  46   struct cache_entry *next;     /* Next entry in list.  */
  47 };
  48
  49 /* List of all cache entries.  */
  50 static struct cache_entry *entries;
  51
  52 static const char *flag_descr[] =
  53 { "libc4", "ELF", "libc5", "libc6"};
  54
  55 /* Print a single entry.  */
  56 static void
  57 print_entry (const char *lib, int flag, unsigned int osversion,
  58              uint64_t hwcap, const char *key)
  59 {
  60   printf ("\t%s (", lib);
  61   switch (flag & FLAG_TYPE_MASK)
  62     {
  63     case FLAG_LIBC4:
  64     case FLAG_ELF:
  65     case FLAG_ELF_LIBC5:
  66     case FLAG_ELF_LIBC6:
  67       fputs (flag_descr[flag & FLAG_TYPE_MASK], stdout);
  68       break;
  69     default:
  70       fputs (_("unknown"), stdout);
  71       break;
  72     }
  73   switch (flag & FLAG_REQUIRED_MASK)
  74     {
  75     case FLAG_SPARC_LIB64:
  76       fputs (",64bit", stdout);
  77       break;
  78     case FLAG_IA64_LIB64:
  79       fputs (",IA-64", stdout);
  80       break;
  81     case FLAG_X8664_LIB64:
  82       fputs (",x86-64", stdout);
  83       break;
  84     case FLAG_S390_LIB64:
  85       fputs(",64bit", stdout);
  86       break;
  87     case FLAG_POWERPC_LIB64:
  88       fputs(",64bit", stdout);
  89       break;
  90     case FLAG_MIPS64_LIBN32:
  91       fputs(",N32", stdout);
  92       break;
  93     case FLAG_MIPS64_LIBN64:
  94       fputs(",64bit", stdout);
  95     case 0:
  96       break;
  97     default:
  98       printf (",%d", flag & FLAG_REQUIRED_MASK);
  99       break;
 100     }
 101   if (hwcap != 0)
 102     printf (", hwcap: %#.16" PRIx64, hwcap);
 103   if (osversion != 0)
 104     {
 105       static const char *const abi_tag_os[] =
 106       {
 107         [0] = "Linux",
 108         [1] = "Hurd",
 109         [2] = "Solaris",
 110         [3] = "FreeBSD",
 111         [4] = "kNetBSD",
 112         [5] = N_("Unknown OS")
 113       };
 114 #define MAXTAG (sizeof abi_tag_os / sizeof abi_tag_os[0] - 1)
 115       unsigned int os = osversion >> 24;
 116
 117       printf (_(", OS ABI: %s %d.%d.%d"),
 118               _(abi_tag_os[os > MAXTAG ? MAXTAG : os]),
 119               (osversion >> 16) & 0xff,
 120               (osversion >> 8) & 0xff,
 121               osversion & 0xff);
 122     }
 123   printf (") => %s\n", key);
 124 }
 125
 126
 127 /* Print the whole cache file, if a file contains the new cache format
 128    hidden in the old one, print the contents of the new format.  */
 129 void
 130 print_cache (const char *cache_name)
 131 {
 132   size_t cache_size;
 133   struct stat64 st;
 134   int fd;
 135   unsigned int i;
 136   struct cache_file *cache;
 137   struct cache_file_new *cache_new = NULL;
 138   const char *cache_data;
 139   int format = 0;
 140
 141   fd = open (cache_name, O_RDONLY);
 142   if (fd < 0)
 143     error (EXIT_FAILURE, errno, _("Can't open cache file %s\n"), cache_name);
 144
 145   if (fstat64 (fd, &st) < 0
 146       /* No need to map the file if it is empty.  */
 147       || st.st_size == 0)
 148     {
 149       close (fd);
 150       return;
 151     }
 152
 153   cache = mmap (0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
 154   if (cache == MAP_FAILED)
 155     error (EXIT_FAILURE, errno, _("mmap of cache file failed.\n"));
 156   cache_size = st.st_size;
 157
 158   if (cache_size < sizeof (struct cache_file))
 159     error (EXIT_FAILURE, 0, _("File is not a cache file.\n"));
 160
 161   if (memcmp (cache->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1))
 162     {
 163       /* This can only be the new format without the old one.  */
 164       cache_new = (struct cache_file_new *) cache;
 165
 166       if (memcmp (cache_new->magic, CACHEMAGIC_NEW, sizeof CACHEMAGIC_NEW - 1)
 167           || memcmp (cache_new->version, CACHE_VERSION,
 168                       sizeof CACHE_VERSION - 1))
 169         error (EXIT_FAILURE, 0, _("File is not a cache file.\n"));
 170       format = 1;
 171       /* This is where the strings start.  */
 172       cache_data = (const char *) cache_new;
 173     }
 174   else
 175     {
 176       size_t offset = ALIGN_CACHE (sizeof (struct cache_file)
 177                                    + (cache->nlibs
 178                                       * sizeof (struct file_entry)));
 179       /* This is where the strings start.  */
 180       cache_data = (const char *) &cache->libs[cache->nlibs];
 181
 182       /* Check for a new cache embedded in the old format.  */
 183       if (cache_size >
 184           (offset + sizeof (struct cache_file_new)))
 185         {
 186
 187           cache_new = (struct cache_file_new *) ((void *)cache + offset);
 188
 189           if (memcmp (cache_new->magic, CACHEMAGIC_NEW,
 190                       sizeof CACHEMAGIC_NEW - 1) == 0
 191               && memcmp (cache_new->version, CACHE_VERSION,
 192                          sizeof CACHE_VERSION - 1) == 0)
 193             {
 194               cache_data = (const char *) cache_new;
 195               format = 1;
 196             }
 197         }
 198     }
 199
 200   if (format == 0)
 201     {
 202       printf (_("%d libs found in cache `%s'\n"), cache->nlibs, cache_name);
 203
 204       /* Print everything.  */
 205       for (i = 0; i < cache->nlibs; i++)
 206         print_entry (cache_data + cache->libs[i].key,
 207                      cache->libs[i].flags, 0, 0,
 208                      cache_data + cache->libs[i].value);
 209     }
 210   else if (format == 1)
 211     {
 212       printf (_("%d libs found in cache `%s'\n"),
 213               cache_new->nlibs, cache_name);
 214
 215       /* Print everything.  */
 216       for (i = 0; i < cache_new->nlibs; i++)
 217         print_entry (cache_data + cache_new->libs[i].key,
 218                      cache_new->libs[i].flags,
 219                      cache_new->libs[i].osversion,
 220                      cache_new->libs[i].hwcap,
 221                      cache_data + cache_new->libs[i].value);
 222     }
 223   /* Cleanup.  */
 224   munmap (cache, cache_size);
 225   close (fd);
 226 }
 227
 228 /* Initialize cache data structures.  */
 229 void
 230 init_cache (void)
 231 {
 232   entries = NULL;
 233 }
 234
 235
 236
 237 static
 238 int compare (const struct cache_entry *e1, const struct cache_entry *e2)
 239 {
 240   int res;
 241
 242   /* We need to swap entries here to get the correct sort order.  */
 243   res = _dl_cache_libcmp (e2->lib, e1->lib);
 244   if (res == 0)
 245     {
 246       if (e1->flags < e2->flags)
 247         return 1;
 248       else if (e1->flags > e2->flags)
 249         return -1;
 250       /* Sort by most specific hwcap.  */
 251       else if (e2->bits_hwcap > e1->bits_hwcap)
 252         return 1;
 253       else if (e2->bits_hwcap < e1->bits_hwcap)
 254         return -1;
 255       else if (e2->hwcap > e1->hwcap)
 256         return 1;
 257       else if (e2->hwcap < e1->hwcap)
 258         return -1;
 259       if (e2->osversion > e1->osversion)
 260         return 1;
 261       if (e2->osversion < e1->osversion)
 262         return -1;
 263     }
 264   return res;
 265 }
 266
 267 /* Save the contents of the cache.  */
 268 void
 269 save_cache (const char *cache_name)
 270 {
 271   struct cache_entry *entry;
 272   int fd, idx_old, idx_new;
 273   size_t total_strlen, len;
 274   char *strings, *str, *temp_name;
 275   struct cache_file *file_entries = NULL;
 276   struct cache_file_new *file_entries_new = NULL;
 277   size_t file_entries_size = 0;
 278   size_t file_entries_new_size = 0;
 279   unsigned int str_offset;
 280   /* Number of cache entries.  */
 281   int cache_entry_count = 0;
 282   /* Number of normal cache entries.  */
 283   int cache_entry_old_count = 0;
 284   /* Pad for alignment of cache_file_new.  */
 285   size_t pad;
 286
 287   /* The cache entries are sorted already, save them in this order. */
 288
 289   /* Count the length of all strings.  */
 290   /* The old format doesn't contain hwcap entries and doesn't contain
 291      libraries in subdirectories with hwcaps entries.  Count therefore
 292      also all entries with hwcap == 0.  */
 293   total_strlen = 0;
 294   for (entry = entries; entry != NULL; entry = entry->next)
 295     {
 296       /* Account the final NULs.  */
 297       total_strlen += strlen (entry->lib) + strlen (entry->path) + 2;
 298       ++cache_entry_count;
 299       if (entry->hwcap == 0)
 300         ++cache_entry_old_count;
 301     }
 302
 303   /* Create the on disk cache structure.  */
 304   /* First an array for all strings.  */
 305   strings = (char *)xmalloc (total_strlen);
 306
 307   if (opt_format != 2)
 308     {
 309       /* struct cache_file_new is 64-bit aligned on some arches while
 310          only 32-bit aligned on other arches.  Duplicate last old
 311          cache entry so that new cache in ld.so.cache can be used by
 312          both.  */
 313       if (opt_format != 0)
 314         cache_entry_old_count = (cache_entry_old_count + 1) & ~1;
 315
 316       /* And the list of all entries in the old format.  */
 317       file_entries_size = sizeof (struct cache_file)
 318         + cache_entry_old_count * sizeof (struct file_entry);
 319       file_entries = (struct cache_file *) xmalloc (file_entries_size);
 320
 321       /* Fill in the header.  */
 322       memset (file_entries, 0, sizeof (struct cache_file));
 323       memcpy (file_entries->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1);
 324
 325       file_entries->nlibs = cache_entry_old_count;
 326     }
 327
 328   if (opt_format != 0)
 329     {
 330       /* And the list of all entries in the new format.  */
 331       file_entries_new_size = sizeof (struct cache_file_new)
 332         + cache_entry_count * sizeof (struct file_entry_new);
 333       file_entries_new =
 334         (struct cache_file_new *) xmalloc (file_entries_new_size);
 335
 336       /* Fill in the header.  */
 337       memset (file_entries_new, 0, sizeof (struct cache_file_new));
 338       memcpy (file_entries_new->magic, CACHEMAGIC_NEW,
 339               sizeof CACHEMAGIC_NEW - 1);
 340       memcpy (file_entries_new->version, CACHE_VERSION,
 341               sizeof CACHE_VERSION - 1);
 342
 343       file_entries_new->nlibs = cache_entry_count;
 344       file_entries_new->len_strings = total_strlen;
 345     }
 346
 347   pad = ALIGN_CACHE (file_entries_size) - file_entries_size;
 348
 349   /* If we have both formats, we hide the new format in the strings
 350      table, we have to adjust all string indices for this so that
 351      old libc5/glibc 2 dynamic linkers just ignore them.  */
 352   if (opt_format != 0)
 353     str_offset = file_entries_new_size;
 354   else
 355     str_offset = 0;
 356
 357   str = strings;
 358   for (idx_old = 0, idx_new = 0, entry = entries; entry != NULL;
 359        entry = entry->next, ++idx_new)
 360     {
 361       /* First the library.  */
 362       if (opt_format != 2 && entry->hwcap == 0)
 363         {
 364           file_entries->libs[idx_old].flags = entry->flags;
 365           /* XXX: Actually we can optimize here and remove duplicates.  */
 366           file_entries->libs[idx_old].key = str_offset + pad;
 367         }
 368       if (opt_format != 0)
 369         {
 370           /* We could subtract file_entries_new_size from str_offset -
 371              not doing so makes the code easier, the string table
 372              always begins at the beginning of the the new cache
 373              struct.  */
 374           file_entries_new->libs[idx_new].flags = entry->flags;
 375           file_entries_new->libs[idx_new].osversion = entry->osversion;
 376           file_entries_new->libs[idx_new].hwcap = entry->hwcap;
 377           file_entries_new->libs[idx_new].key = str_offset;
 378         }
 379       len = strlen (entry->lib);
 380       str = stpcpy (str, entry->lib);
 381       /* Account the final NUL.  */
 382       ++str;
 383       str_offset += len + 1;
 384       /* Then the path.  */
 385       if (opt_format != 2 && entry->hwcap == 0)
 386         file_entries->libs[idx_old].value = str_offset + pad;
 387       if (opt_format != 0)
 388         file_entries_new->libs[idx_new].value = str_offset;
 389       len = strlen (entry->path);
 390       str = stpcpy (str, entry->path);
 391       /* Account the final NUL.  */
 392       ++str;
 393       str_offset += len + 1;
 394       /* Ignore entries with hwcap for old format.  */
 395       if (entry->hwcap == 0)
 396         ++idx_old;
 397     }
 398
 399   /* Duplicate last old cache entry if needed.  */
 400   if (opt_format != 2
 401       && idx_old < cache_entry_old_count)
 402     file_entries->libs[idx_old] = file_entries->libs[idx_old - 1];
 403
 404   /* Write out the cache.  */
 405
 406   /* Write cache first to a temporary file and rename it later.  */
 407   temp_name = xmalloc (strlen (cache_name) + 2);
 408   sprintf (temp_name, "%s~", cache_name);
 409   /* First remove an old copy if it exists.  */
 410   if (unlink (temp_name) && errno != ENOENT)
 411     error (EXIT_FAILURE, errno, _("Can't remove old temporary cache file %s"),
 412            temp_name);
 413
 414   /* Create file.  */
 415   fd = open (temp_name, O_CREAT|O_WRONLY|O_TRUNC|O_NOFOLLOW,
 416              S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 417   if (fd < 0)
 418     error (EXIT_FAILURE, errno, _("Can't create temporary cache file %s"),
 419            temp_name);
 420
 421   /* Write contents.  */
 422   if (opt_format != 2)
 423     {
 424       if (write (fd, file_entries, file_entries_size)
 425           != (ssize_t)file_entries_size)
 426         error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 427     }
 428   if (opt_format != 0)
 429     {
 430       /* Align cache.  */
 431       if (opt_format != 2)
 432         {
 433           char zero[pad];
 434           if (write (fd, zero, pad) != (ssize_t)pad)
 435             error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 436         }
 437       if (write (fd, file_entries_new, file_entries_new_size)
 438           != (ssize_t)file_entries_new_size)
 439         error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 440     }
 441
 442   if (write (fd, strings, total_strlen) != (ssize_t)total_strlen)
 443     error (EXIT_FAILURE, errno, _("Writing of cache data failed."));
 444
 445   close (fd);
 446
 447   /* Make sure user can always read cache file */
 448   if (chmod (temp_name, S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR))
 449     error (EXIT_FAILURE, errno,
 450            _("Changing access rights of %s to %#o failed"), temp_name,
 451            S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 452
 453   /* Move temporary to its final location.  */
 454   if (rename (temp_name, cache_name))
 455     error (EXIT_FAILURE, errno, _("Renaming of %s to %s failed"), temp_name,
 456            cache_name);
 457
 458   /* Free all allocated memory.  */
 459   free (file_entries);
 460   free (strings);
 461
 462   while (entries)
 463     {
 464       entry = entries;
 465       free (entry->path);
 466       free (entry->lib);
 467       entries = entries->next;
 468       free (entry);
 469     }
 470 }
 471
 472
 473 /* Add one library to the cache.  */
 474 void
 475 add_to_cache (const char *path, const char *lib, int flags,
 476               unsigned int osversion, uint64_t hwcap)
 477 {
 478   struct cache_entry *new_entry, *ptr, *prev;
 479   char *full_path;
 480   size_t len, i;
 481
 482   new_entry = (struct cache_entry *) xmalloc (sizeof (struct cache_entry));
 483
 484   len = strlen (lib) + strlen (path) + 2;
 485
 486   full_path = (char *) xmalloc (len);
 487   snprintf (full_path, len, "%s/%s", path, lib);
 488
 489   new_entry->lib = xstrdup (lib);
 490   new_entry->path = full_path;
 491   new_entry->flags = flags;
 492   new_entry->osversion = osversion;
 493   new_entry->hwcap = hwcap;
 494   new_entry->bits_hwcap = 0;
 495
 496   /* Count the number of bits set in the masked value.  */
 497   for (i = 0; (~((1ULL << i) - 1) & hwcap) != 0 && i < 8 * sizeof (hwcap); ++i)
 498     if ((hwcap & (1ULL << i)) != 0)
 499       ++new_entry->bits_hwcap;
 500
 501
 502   /* Keep the list sorted - search for right place to insert.  */
 503   ptr = entries;
 504   prev = entries;
 505   while (ptr != NULL)
 506     {
 507       if (compare (ptr, new_entry) > 0)
 508         break;
 509       prev = ptr;
 510       ptr = ptr->next;
 511     }
 512   /* Is this the first entry?  */
 513   if (ptr == entries)
 514     {
 515       new_entry->next = entries;
 516       entries = new_entry;
 517     }
 518   else
 519     {
 520       new_entry->next = prev->next;
 521       prev->next = new_entry;
 522     }
 523 }