elf/cache.c

   1 /* Copyright (C) 1999, 2000, 2001, 2002, 2003
   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: 0x%" 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] = N_("Unknown OS")
 112       };
 113 #define MAXTAG (sizeof abi_tag_os / sizeof abi_tag_os[0] - 1)
 114       unsigned int os = osversion >> 24;
 115
 116       printf (_(", OS ABI: %s %d.%d.%d"),
 117               _(abi_tag_os[os > MAXTAG ? MAXTAG : os]),
 118               (osversion >> 16) & 0xff,
 119               (osversion >> 8) & 0xff,
 120               osversion & 0xff);
 121     }
 122   printf (") => %s\n", key);
 123 }
 124
 125
 126 /* Print the whole cache file, if a file contains the new cache format
 127    hidden in the old one, print the contents of the new format.  */
 128 void
 129 print_cache (const char *cache_name)
 130 {
 131   size_t cache_size;
 132   struct stat64 st;
 133   int fd;
 134   unsigned int i;
 135   struct cache_file *cache;
 136   struct cache_file_new *cache_new = NULL;
 137   const char *cache_data;
 138   int format = 0;
 139
 140   fd = open (cache_name, O_RDONLY);
 141   if (fd < 0)
 142     error (EXIT_FAILURE, errno, _("Can't open cache file %s\n"), cache_name);
 143
 144   if (fstat64 (fd, &st) < 0
 145       /* No need to map the file if it is empty.  */
 146       || st.st_size == 0)
 147     {
 148       close (fd);
 149       return;
 150     }
 151
 152   cache = mmap (0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
 153   if (cache == MAP_FAILED)
 154     error (EXIT_FAILURE, errno, _("mmap of cache file failed.\n"));
 155   cache_size = st.st_size;
 156
 157   if (cache_size < sizeof (struct cache_file))
 158     error (EXIT_FAILURE, 0, _("File is not a cache file.\n"));
 159
 160   if (memcmp (cache->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1))
 161     {
 162       /* This can only be the new format without the old one.  */
 163       cache_new = (struct cache_file_new *) cache;
 164
 165       if (memcmp (cache_new->magic, CACHEMAGIC_NEW, sizeof CACHEMAGIC_NEW - 1)
 166           || memcmp (cache_new->version, CACHE_VERSION,
 167                       sizeof CACHE_VERSION - 1))
 168         error (EXIT_FAILURE, 0, _("File is not a cache file.\n"));
 169       format = 1;
 170       /* This is where the strings start.  */
 171       cache_data = (const char *) cache_new;
 172     }
 173   else
 174     {
 175       size_t offset = ALIGN_CACHE (sizeof (struct cache_file)
 176                                    + (cache->nlibs
 177                                       * sizeof (struct file_entry)));
 178       /* This is where the strings start.  */
 179       cache_data = (const char *) &cache->libs[cache->nlibs];
 180
 181       /* Check for a new cache embedded in the old format.  */
 182       if (cache_size >
 183           (offset + sizeof (struct cache_file_new)))
 184         {
 185
 186           cache_new = (struct cache_file_new *) ((void *)cache + offset);
 187
 188           if (memcmp (cache_new->magic, CACHEMAGIC_NEW,
 189                       sizeof CACHEMAGIC_NEW - 1) == 0
 190               && memcmp (cache_new->version, CACHE_VERSION,
 191                          sizeof CACHE_VERSION - 1) == 0)
 192             {
 193               cache_data = (const char *) cache_new;
 194               format = 1;
 195             }
 196         }
 197     }
 198
 199   if (format == 0)
 200     {
 201       printf (_("%d libs found in cache `%s'\n"), cache->nlibs, cache_name);
 202
 203       /* Print everything.  */
 204       for (i = 0; i < cache->nlibs; i++)
 205         print_entry (cache_data + cache->libs[i].key,
 206                      cache->libs[i].flags, 0, 0,
 207                      cache_data + cache->libs[i].value);
 208     }
 209   else if (format == 1)
 210     {
 211       printf (_("%d libs found in cache `%s'\n"),
 212               cache_new->nlibs, cache_name);
 213
 214       /* Print everything.  */
 215       for (i = 0; i < cache_new->nlibs; i++)
 216         print_entry (cache_data + cache_new->libs[i].key,
 217                      cache_new->libs[i].flags,
 218                      cache_new->libs[i].osversion,
 219                      cache_new->libs[i].hwcap,
 220                      cache_data + cache_new->libs[i].value);
 221     }
 222   /* Cleanup.  */
 223   munmap (cache, cache_size);
 224   close (fd);
 225 }
 226
 227 /* Initialize cache data structures.  */
 228 void
 229 init_cache (void)
 230 {
 231   entries = NULL;
 232 }
 233
 234
 235
 236 static
 237 int compare (const struct cache_entry *e1, const struct cache_entry *e2)
 238 {
 239   int res;
 240
 241   /* We need to swap entries here to get the correct sort order.  */
 242   res = _dl_cache_libcmp (e2->lib, e1->lib);
 243   if (res == 0)
 244     {
 245       if (e1->flags < e2->flags)
 246         return 1;
 247       else if (e1->flags > e2->flags)
 248         return -1;
 249       /* Sort by most specific hwcap.  */
 250       else if (e2->bits_hwcap > e1->bits_hwcap)
 251         return 1;
 252       else if (e2->bits_hwcap < e1->bits_hwcap)
 253         return -1;
 254       else if (e2->hwcap > e1->hwcap)
 255         return 1;
 256       else if (e2->hwcap < e1->hwcap)
 257         return -1;
 258       if (e2->osversion > e1->osversion)
 259         return 1;
 260       if (e2->osversion < e1->osversion)
 261         return -1;
 262     }
 263   return res;
 264 }
 265
 266 /* Save the contents of the cache.  */
 267 void
 268 save_cache (const char *cache_name)
 269 {
 270   struct cache_entry *entry;
 271   int fd, idx_old, idx_new;
 272   size_t total_strlen, len;
 273   char *strings, *str, *temp_name;
 274   struct cache_file *file_entries = NULL;
 275   struct cache_file_new *file_entries_new = NULL;
 276   size_t file_entries_size = 0;
 277   size_t file_entries_new_size = 0;
 278   unsigned int str_offset;
 279   /* Number of cache entries.  */
 280   int cache_entry_count = 0;
 281   /* Number of normal cache entries.  */
 282   int cache_entry_old_count = 0;
 283   /* Pad for alignment of cache_file_new.  */
 284   size_t pad;
 285
 286   /* The cache entries are sorted already, save them in this order. */
 287
 288   /* Count the length of all strings.  */
 289   /* The old format doesn't contain hwcap entries and doesn't contain
 290      libraries in subdirectories with hwcaps entries.  Count therefore
 291      also all entries with hwcap == 0.  */
 292   total_strlen = 0;
 293   for (entry = entries; entry != NULL; entry = entry->next)
 294     {
 295       /* Account the final NULs.  */
 296       total_strlen += strlen (entry->lib) + strlen (entry->path) + 2;
 297       ++cache_entry_count;
 298       if (entry->hwcap == 0)
 299         ++cache_entry_old_count;
 300     }
 301
 302   /* Create the on disk cache structure.  */
 303   /* First an array for all strings.  */
 304   strings = (char *)xmalloc (total_strlen);
 305
 306   if (opt_format != 2)
 307     {
 308       /* And the list of all entries in the old format.  */
 309       file_entries_size = sizeof (struct cache_file)
 310         + cache_entry_old_count * sizeof (struct file_entry);
 311       file_entries = (struct cache_file *) xmalloc (file_entries_size);
 312
 313       /* Fill in the header.  */
 314       memset (file_entries, 0, sizeof (struct cache_file));
 315       memcpy (file_entries->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1);
 316
 317       file_entries->nlibs = cache_entry_old_count;
 318     }
 319
 320   if (opt_format != 0)
 321     {
 322       /* And the list of all entries in the new format.  */
 323       file_entries_new_size = sizeof (struct cache_file_new)
 324         + cache_entry_count * sizeof (struct file_entry_new);
 325       file_entries_new =
 326         (struct cache_file_new *) xmalloc (file_entries_new_size);
 327
 328       /* Fill in the header.  */
 329       memset (file_entries_new, 0, sizeof (struct cache_file_new));
 330       memcpy (file_entries_new->magic, CACHEMAGIC_NEW,
 331               sizeof CACHEMAGIC_NEW - 1);
 332       memcpy (file_entries_new->version, CACHE_VERSION,
 333               sizeof CACHE_VERSION - 1);
 334
 335       file_entries_new->nlibs = cache_entry_count;
 336       file_entries_new->len_strings = total_strlen;
 337     }
 338
 339   pad = ALIGN_CACHE (file_entries_size) - file_entries_size;
 340
 341   /* If we have both formats, we hide the new format in the strings
 342      table, we have to adjust all string indices for this so that
 343      old libc5/glibc 2 dynamic linkers just ignore them.  */
 344   if (opt_format != 0)
 345     str_offset = file_entries_new_size;
 346   else
 347     str_offset = 0;
 348
 349   str = strings;
 350   for (idx_old = 0, idx_new = 0, entry = entries; entry != NULL;
 351        entry = entry->next, ++idx_new)
 352     {
 353       /* First the library.  */
 354       if (opt_format != 2)
 355         {
 356           file_entries->libs[idx_old].flags = entry->flags;
 357           /* XXX: Actually we can optimize here and remove duplicates.  */
 358           file_entries->libs[idx_old].key = str_offset + pad;
 359         }
 360       if (opt_format != 0)
 361         {
 362           /* We could subtract file_entries_new_size from str_offset -
 363              not doing so makes the code easier, the string table
 364              always begins at the beginning of the the new cache
 365              struct.  */
 366           file_entries_new->libs[idx_new].flags = entry->flags;
 367           file_entries_new->libs[idx_new].osversion = entry->osversion;
 368           file_entries_new->libs[idx_new].hwcap = entry->hwcap;
 369           file_entries_new->libs[idx_new].key = str_offset;
 370         }
 371       len = strlen (entry->lib);
 372       str = stpcpy (str, entry->lib);
 373       /* Account the final NUL.  */
 374       ++str;
 375       str_offset += len + 1;
 376       /* Then the path.  */
 377       if (opt_format != 2)
 378         file_entries->libs[idx_old].value = str_offset + pad;
 379       if (opt_format != 0)
 380         file_entries_new->libs[idx_new].value = str_offset;
 381       len = strlen (entry->path);
 382       str = stpcpy (str, entry->path);
 383       /* Account the final NUL.  */
 384       ++str;
 385       str_offset += len + 1;
 386       /* Ignore entries with hwcap for old format.  */
 387       if (entry->hwcap == 0)
 388         ++idx_old;
 389     }
 390
 391   /* Write out the cache.  */
 392
 393   /* Write cache first to a temporary file and rename it later.  */
 394   temp_name = xmalloc (strlen (cache_name) + 2);
 395   sprintf (temp_name, "%s~", cache_name);
 396   /* First remove an old copy if it exists.  */
 397   if (unlink (temp_name) && errno != ENOENT)
 398     error (EXIT_FAILURE, errno, _("Can't remove old temporary cache file %s"),
 399            temp_name);
 400
 401   /* Create file.  */
 402   fd = open (temp_name, O_CREAT|O_WRONLY|O_TRUNC|O_NOFOLLOW,
 403              S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 404   if (fd < 0)
 405     error (EXIT_FAILURE, errno, _("Can't create temporary cache file %s"),
 406            temp_name);
 407
 408   /* Write contents.  */
 409   if (opt_format != 2)
 410     {
 411       if (write (fd, file_entries, file_entries_size)
 412           != (ssize_t)file_entries_size)
 413         error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 414     }
 415   if (opt_format != 0)
 416     {
 417       /* Align cache.  */
 418       if (opt_format != 2)
 419         {
 420           char zero[pad];
 421           if (write (fd, zero, pad) != (ssize_t)pad)
 422             error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 423         }
 424       if (write (fd, file_entries_new, file_entries_new_size)
 425           != (ssize_t)file_entries_new_size)
 426         error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 427     }
 428
 429   if (write (fd, strings, total_strlen) != (ssize_t)total_strlen)
 430     error (EXIT_FAILURE, errno, _("Writing of cache data failed."));
 431
 432   close (fd);
 433
 434   /* Make sure user can always read cache file */
 435   if (chmod (temp_name, S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR))
 436     error (EXIT_FAILURE, errno,
 437            _("Changing access rights of %s to %#o failed"), temp_name,
 438            S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 439
 440   /* Move temporary to its final location.  */
 441   if (rename (temp_name, cache_name))
 442     error (EXIT_FAILURE, errno, _("Renaming of %s to %s failed"), temp_name,
 443            cache_name);
 444
 445   /* Free all allocated memory.  */
 446   free (file_entries);
 447   free (strings);
 448
 449   while (entries)
 450     {
 451       entry = entries;
 452       free (entry->path);
 453       free (entry->lib);
 454       entries = entries->next;
 455       free (entry);
 456     }
 457 }
 458
 459
 460 /* Add one library to the cache.  */
 461 void
 462 add_to_cache (const char *path, const char *lib, int flags,
 463               unsigned int osversion, uint64_t hwcap)
 464 {
 465   struct cache_entry *new_entry, *ptr, *prev;
 466   char *full_path;
 467   size_t len, i;
 468
 469   new_entry = (struct cache_entry *) xmalloc (sizeof (struct cache_entry));
 470
 471   len = strlen (lib) + strlen (path) + 2;
 472
 473   full_path = (char *) xmalloc (len);
 474   snprintf (full_path, len, "%s/%s", path, lib);
 475
 476   new_entry->lib = xstrdup (lib);
 477   new_entry->path = full_path;
 478   new_entry->flags = flags;
 479   new_entry->osversion = osversion;
 480   new_entry->hwcap = hwcap;
 481   new_entry->bits_hwcap = 0;
 482
 483   /* Count the number of bits set in the masked value.  */
 484   for (i = 0; (~((1ULL << i) - 1) & hwcap) != 0 && i < 8 * sizeof (hwcap); ++i)
 485     if ((hwcap & (1ULL << i)) != 0)
 486       ++new_entry->bits_hwcap;
 487
 488
 489   /* Keep the list sorted - search for right place to insert.  */
 490   ptr = entries;
 491   prev = entries;
 492   while (ptr != NULL)
 493     {
 494       if (compare (ptr, new_entry) > 0)
 495         break;
 496       prev = ptr;
 497       ptr = ptr->next;
 498     }
 499   /* Is this the first entry?  */
 500   if (ptr == entries)
 501     {
 502       new_entry->next = entries;
 503       entries = new_entry;
 504     }
 505   else
 506     {
 507       new_entry->next = prev->next;
 508       prev->next = new_entry;
 509     }
 510 }