elf/cache.c

   1 /* Copyright (C) 1999, 2000, 2001 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 #ifdef __sparc__
  75     case FLAG_SPARC_LIB64:
  76       fputs (",64bit", stdout);
  77 #endif
  78 #if defined __ia64__ || defined __i386__
  79     case FLAG_IA64_LIB64:
  80       fputs (",IA-64", stdout);
  81 #endif
  82 #if defined __s390__ || defined __s390x__
  83     case FLAG_S390_LIB64:
  84       fputs(",64bit", stdout);
  85 #endif
  86     case 0:
  87       break;
  88     default:
  89       printf (",%d", flag & FLAG_REQUIRED_MASK);
  90       break;
  91     }
  92   if (hwcap != 0)
  93     printf (", hwcap: 0x%" PRIx64, hwcap);
  94   if (osversion != 0)
  95     {
  96       static const char *const abi_tag_os[] =
  97       {
  98         [0] = "Linux",
  99         [1] = "Hurd",
 100         [2] = "Solaris",
 101         [3] = N_("Unknown OS")
 102       };
 103       unsigned int os = osversion >> 24;
 104
 105       printf (_(", OS ABI: %s %d.%d.%d"),
 106               _(abi_tag_os[os > 3 ? 3 : os]),
 107               (osversion >> 16) & 0xff,
 108               (osversion >> 8) & 0xff,
 109               osversion & 0xff);
 110     }
 111   printf (") => %s\n", key);
 112 }
 113
 114
 115 /* Print the whole cache file, if a file contains the new cache format
 116    hidden in the old one, print the contents of the new format.  */
 117 void
 118 print_cache (const char *cache_name)
 119 {
 120   size_t cache_size;
 121   struct stat64 st;
 122   int fd;
 123   unsigned int i;
 124   struct cache_file *cache;
 125   struct cache_file_new *cache_new = NULL;
 126   const char *cache_data;
 127   int format = 0;
 128
 129   fd = open (cache_name, O_RDONLY);
 130   if (fd < 0)
 131     error (EXIT_FAILURE, errno, _("Can't open cache file %s\n"), cache_name);
 132
 133   if (fstat64 (fd, &st) < 0
 134       /* No need to map the file if it is empty.  */
 135       || st.st_size == 0)
 136     {
 137       close (fd);
 138       return;
 139     }
 140
 141   cache = mmap (0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
 142   if (cache == MAP_FAILED)
 143     error (EXIT_FAILURE, errno, _("mmap of cache file failed.\n"));
 144   cache_size = st.st_size;
 145
 146   if (cache_size < sizeof (struct cache_file))
 147     error (EXIT_FAILURE, 0, _("File is not a cache file.\n"));
 148
 149   if (memcmp (cache->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1))
 150     {
 151       /* This can only be the new format without the old one.  */
 152       cache_new = (struct cache_file_new *) cache;
 153
 154       if (memcmp (cache_new->magic, CACHEMAGIC_NEW, sizeof CACHEMAGIC_NEW - 1)
 155           || memcmp (cache_new->version, CACHE_VERSION,
 156                       sizeof CACHE_VERSION - 1))
 157         error (EXIT_FAILURE, 0, _("File is not a cache file.\n"));
 158       format = 1;
 159       /* This is where the strings start.  */
 160       cache_data = (const char *) cache_new;
 161     }
 162   else
 163     {
 164       size_t offset = ALIGN_CACHE (sizeof (struct cache_file)
 165                                    + (cache->nlibs
 166                                       * sizeof (struct file_entry)));
 167       /* This is where the strings start.  */
 168       cache_data = (const char *) &cache->libs[cache->nlibs];
 169
 170       /* Check for a new cache embedded in the old format.  */
 171       if (cache_size >
 172           (offset + sizeof (struct cache_file_new)))
 173         {
 174
 175           cache_new = (struct cache_file_new *) ((void *)cache + offset);
 176
 177           if (memcmp (cache_new->magic, CACHEMAGIC_NEW,
 178                       sizeof CACHEMAGIC_NEW - 1) == 0
 179               && memcmp (cache_new->version, CACHE_VERSION,
 180                          sizeof CACHE_VERSION - 1) == 0)
 181             {
 182               cache_data = (const char *) cache_new;
 183               format = 1;
 184             }
 185         }
 186     }
 187
 188   if (format == 0)
 189     {
 190       printf (_("%d libs found in cache `%s'\n"), cache->nlibs, cache_name);
 191
 192       /* Print everything.  */
 193       for (i = 0; i < cache->nlibs; i++)
 194         print_entry (cache_data + cache->libs[i].key,
 195                      cache->libs[i].flags, 0, 0,
 196                      cache_data + cache->libs[i].value);
 197     }
 198   else if (format == 1)
 199     {
 200       printf (_("%d libs found in cache `%s'\n"),
 201               cache_new->nlibs, cache_name);
 202
 203       /* Print everything.  */
 204       for (i = 0; i < cache_new->nlibs; i++)
 205         print_entry (cache_data + cache_new->libs[i].key,
 206                      cache_new->libs[i].flags,
 207                      cache_new->libs[i].osversion,
 208                      cache_new->libs[i].hwcap,
 209                      cache_data + cache_new->libs[i].value);
 210     }
 211   /* Cleanup.  */
 212   munmap (cache, cache_size);
 213   close (fd);
 214 }
 215
 216 /* Initialize cache data structures.  */
 217 void
 218 init_cache (void)
 219 {
 220   entries = NULL;
 221 }
 222
 223
 224
 225 static
 226 int compare (const struct cache_entry *e1, const struct cache_entry *e2)
 227 {
 228   int res;
 229
 230   /* We need to swap entries here to get the correct sort order.  */
 231   res = _dl_cache_libcmp (e2->lib, e1->lib);
 232   if (res == 0)
 233     {
 234       if (e1->flags < e2->flags)
 235         return 1;
 236       else if (e1->flags > e2->flags)
 237         return -1;
 238       /* Sort by most specific hwcap.  */
 239       else if (e2->bits_hwcap > e1->bits_hwcap)
 240         return 1;
 241       else if (e2->bits_hwcap < e1->bits_hwcap)
 242         return -1;
 243       else if (e2->hwcap > e1->hwcap)
 244         return 1;
 245       else if (e2->hwcap < e1->hwcap)
 246         return -1;
 247       if (e2->osversion > e1->osversion)
 248         return 1;
 249       if (e2->osversion < e1->osversion)
 250         return -1;
 251     }
 252   return res;
 253 }
 254
 255 /* Save the contents of the cache.  */
 256 void
 257 save_cache (const char *cache_name)
 258 {
 259   struct cache_entry *entry;
 260   int fd, idx_old, idx_new;
 261   size_t total_strlen, len;
 262   char *strings, *str, *temp_name;
 263   struct cache_file *file_entries = NULL;
 264   struct cache_file_new *file_entries_new = NULL;
 265   size_t file_entries_size = 0;
 266   size_t file_entries_new_size = 0;
 267   unsigned int str_offset;
 268   /* Number of cache entries.  */
 269   int cache_entry_count = 0;
 270   /* Number of normal cache entries.  */
 271   int cache_entry_old_count = 0;
 272   /* Pad for alignment of cache_file_new.  */
 273   size_t pad;
 274
 275   /* The cache entries are sorted already, save them in this order. */
 276
 277   /* Count the length of all strings.  */
 278   /* The old format doesn't contain hwcap entries and doesn't contain
 279      libraries in subdirectories with hwcaps entries.  Count therefore
 280      also all entries with hwcap == 0.  */
 281   total_strlen = 0;
 282   for (entry = entries; entry != NULL; entry = entry->next)
 283     {
 284       /* Account the final NULs.  */
 285       total_strlen += strlen (entry->lib) + strlen (entry->path) + 2;
 286       ++cache_entry_count;
 287       if (entry->hwcap == 0)
 288         ++cache_entry_old_count;
 289     }
 290
 291   /* Create the on disk cache structure.  */
 292   /* First an array for all strings.  */
 293   strings = (char *)xmalloc (total_strlen);
 294
 295   if (opt_format != 2)
 296     {
 297       /* And the list of all entries in the old format.  */
 298       file_entries_size = sizeof (struct cache_file)
 299         + cache_entry_old_count * sizeof (struct file_entry);
 300       file_entries = (struct cache_file *) xmalloc (file_entries_size);
 301
 302       /* Fill in the header.  */
 303       memset (file_entries, 0, sizeof (struct cache_file));
 304       memcpy (file_entries->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1);
 305
 306       file_entries->nlibs = cache_entry_old_count;
 307     }
 308
 309   if (opt_format != 0)
 310     {
 311       /* And the list of all entries in the new format.  */
 312       file_entries_new_size = sizeof (struct cache_file_new)
 313         + cache_entry_count * sizeof (struct file_entry_new);
 314       file_entries_new =
 315         (struct cache_file_new *) xmalloc (file_entries_new_size);
 316
 317       /* Fill in the header.  */
 318       memset (file_entries_new, 0, sizeof (struct cache_file_new));
 319       memcpy (file_entries_new->magic, CACHEMAGIC_NEW,
 320               sizeof CACHEMAGIC_NEW - 1);
 321       memcpy (file_entries_new->version, CACHE_VERSION,
 322               sizeof CACHE_VERSION - 1);
 323
 324       file_entries_new->nlibs = cache_entry_count;
 325       file_entries_new->len_strings = total_strlen;
 326     }
 327
 328   pad = ALIGN_CACHE (file_entries_size) - file_entries_size;
 329
 330   /* If we have both formats, we hide the new format in the strings
 331      table, we have to adjust all string indices for this so that
 332      old libc5/glibc 2 dynamic linkers just ignore them.  */
 333   if (opt_format != 0)
 334     str_offset = file_entries_new_size;
 335   else
 336     str_offset = 0;
 337
 338   str = strings;
 339   for (idx_old = 0, idx_new = 0, entry = entries; entry != NULL;
 340        entry = entry->next, ++idx_new)
 341     {
 342       /* First the library.  */
 343       if (opt_format != 2)
 344         {
 345           file_entries->libs[idx_old].flags = entry->flags;
 346           /* XXX: Actually we can optimize here and remove duplicates.  */
 347           file_entries->libs[idx_old].key = str_offset + pad;
 348         }
 349       if (opt_format != 0)
 350         {
 351           /* We could subtract file_entries_new_size from str_offset -
 352              not doing so makes the code easier, the string table
 353              always begins at the beginning of the the new cache
 354              struct.  */
 355           file_entries_new->libs[idx_new].flags = entry->flags;
 356           file_entries_new->libs[idx_new].osversion = entry->osversion;
 357           file_entries_new->libs[idx_new].hwcap = entry->hwcap;
 358           file_entries_new->libs[idx_new].key = str_offset;
 359         }
 360       len = strlen (entry->lib);
 361       str = stpcpy (str, entry->lib);
 362       /* Account the final NUL.  */
 363       ++str;
 364       str_offset += len + 1;
 365       /* Then the path.  */
 366       if (opt_format != 2)
 367         file_entries->libs[idx_old].value = str_offset + pad;
 368       if (opt_format != 0)
 369         file_entries_new->libs[idx_new].value = str_offset;
 370       len = strlen (entry->path);
 371       str = stpcpy (str, entry->path);
 372       /* Account the final NUL.  */
 373       ++str;
 374       str_offset += len + 1;
 375       /* Ignore entries with hwcap for old format.  */
 376       if (entry->hwcap == 0)
 377         ++idx_old;
 378     }
 379
 380   /* Write out the cache.  */
 381
 382   /* Write cache first to a temporary file and rename it later.  */
 383   temp_name = xmalloc (strlen (cache_name) + 2);
 384   sprintf (temp_name, "%s~", cache_name);
 385   /* First remove an old copy if it exists.  */
 386   if (unlink (temp_name) && errno != ENOENT)
 387     error (EXIT_FAILURE, errno, _("Can't remove old temporary cache file %s"),
 388            temp_name);
 389
 390   /* Create file.  */
 391   fd = open (temp_name, O_CREAT|O_WRONLY|O_TRUNC|O_NOFOLLOW,
 392              S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 393   if (fd < 0)
 394     error (EXIT_FAILURE, errno, _("Can't create temporary cache file %s"),
 395            temp_name);
 396
 397   /* Write contents.  */
 398   if (opt_format != 2)
 399     {
 400       if (write (fd, file_entries, file_entries_size)
 401           != (ssize_t)file_entries_size)
 402         error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 403     }
 404   if (opt_format != 0)
 405     {
 406       /* Align cache.  */
 407       if (opt_format != 2)
 408         {
 409           char zero[pad];
 410           if (write (fd, zero, pad) != (ssize_t)pad)
 411             error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 412         }
 413       if (write (fd, file_entries_new, file_entries_new_size)
 414           != (ssize_t)file_entries_new_size)
 415         error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 416     }
 417
 418   if (write (fd, strings, total_strlen) != (ssize_t)total_strlen)
 419     error (EXIT_FAILURE, errno, _("Writing of cache data failed."));
 420
 421   close (fd);
 422
 423   /* Make sure user can always read cache file */
 424   if (chmod (temp_name, S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR))
 425     error (EXIT_FAILURE, errno,
 426            _("Changing access rights of %s to %#o failed"), temp_name,
 427            S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 428
 429   /* Move temporary to its final location.  */
 430   if (rename (temp_name, cache_name))
 431     error (EXIT_FAILURE, errno, _("Renaming of %s to %s failed"), temp_name,
 432            cache_name);
 433
 434   /* Free all allocated memory.  */
 435   free (file_entries);
 436   free (strings);
 437
 438   while (entries)
 439     {
 440       entry = entries;
 441       free (entry->path);
 442       free (entry->lib);
 443       entries = entries->next;
 444       free (entry);
 445     }
 446 }
 447
 448
 449 /* Add one library to the cache.  */
 450 void
 451 add_to_cache (const char *path, const char *lib, int flags,
 452               unsigned int osversion, uint64_t hwcap)
 453 {
 454   struct cache_entry *new_entry, *ptr, *prev;
 455   char *full_path;
 456   int len, i;
 457
 458   new_entry = (struct cache_entry *) xmalloc (sizeof (struct cache_entry));
 459
 460   len = strlen (lib) + strlen (path) + 2;
 461
 462   full_path = (char *) xmalloc (len);
 463   snprintf (full_path, len, "%s/%s", path, lib);
 464
 465   new_entry->lib = xstrdup (lib);
 466   new_entry->path = full_path;
 467   new_entry->flags = flags;
 468   new_entry->osversion = osversion;
 469   new_entry->hwcap = hwcap;
 470   new_entry->bits_hwcap = 0;
 471
 472   /* Count the number of bits set in the masked value.  */
 473   for (i = 0; (~((1ULL << i) - 1) & hwcap) != 0; ++i)
 474     if ((hwcap & (1ULL << i)) != 0)
 475       ++new_entry->bits_hwcap;
 476
 477
 478   /* Keep the list sorted - search for right place to insert.  */
 479   ptr = entries;
 480   prev = entries;
 481   while (ptr != NULL)
 482     {
 483       if (compare (ptr, new_entry) > 0)
 484         break;
 485       prev = ptr;
 486       ptr = ptr->next;
 487     }
 488   /* Is this the first entry?  */
 489   if (ptr == entries)
 490     {
 491       new_entry->next = entries;
 492       entries = new_entry;
 493     }
 494   else
 495     {
 496       new_entry->next = prev->next;
 497       prev->next = new_entry;
 498     }
 499 }