elf/cache.c

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