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 #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       break;
  82 #endif
  83 #if defined __x86_64__ || defined __i386__
  84     case FLAG_X8664_LIB64:
  85       fputs (",x86-64", stdout);
  86       break;
  87 #endif
  88 #if defined __s390__ || defined __s390x__
  89     case FLAG_S390_LIB64:
  90       fputs(",64bit", stdout);
  91 #endif
  92     case 0:
  93       break;
  94     default:
  95       printf (",%d", flag & FLAG_REQUIRED_MASK);
  96       break;
  97     }
  98   if (hwcap != 0)
  99     printf (", hwcap: 0x%" PRIx64, hwcap);
 100   if (osversion != 0)
 101     {
 102       static const char *const abi_tag_os[] =
 103       {
 104         [0] = "Linux",
 105         [1] = "Hurd",
 106         [2] = "Solaris",
 107         [3] = N_("Unknown OS")
 108       };
 109       unsigned int os = osversion >> 24;
 110
 111       printf (_(", OS ABI: %s %d.%d.%d"),
 112               _(abi_tag_os[os > 3 ? 3 : os]),
 113               (osversion >> 16) & 0xff,
 114               (osversion >> 8) & 0xff,
 115               osversion & 0xff);
 116     }
 117   printf (") => %s\n", key);
 118 }
 119
 120
 121 /* Print the whole cache file, if a file contains the new cache format
 122    hidden in the old one, print the contents of the new format.  */
 123 void
 124 print_cache (const char *cache_name)
 125 {
 126   size_t cache_size;
 127   struct stat64 st;
 128   int fd;
 129   unsigned int i;
 130   struct cache_file *cache;
 131   struct cache_file_new *cache_new = NULL;
 132   const char *cache_data;
 133   int format = 0;
 134
 135   fd = open (cache_name, O_RDONLY);
 136   if (fd < 0)
 137     error (EXIT_FAILURE, errno, _("Can't open cache file %s\n"), cache_name);
 138
 139   if (fstat64 (fd, &st) < 0
 140       /* No need to map the file if it is empty.  */
 141       || st.st_size == 0)
 142     {
 143       close (fd);
 144       return;
 145     }
 146
 147   cache = mmap (0, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
 148   if (cache == MAP_FAILED)
 149     error (EXIT_FAILURE, errno, _("mmap of cache file failed.\n"));
 150   cache_size = st.st_size;
 151
 152   if (cache_size < sizeof (struct cache_file))
 153     error (EXIT_FAILURE, 0, _("File is not a cache file.\n"));
 154
 155   if (memcmp (cache->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1))
 156     {
 157       /* This can only be the new format without the old one.  */
 158       cache_new = (struct cache_file_new *) cache;
 159
 160       if (memcmp (cache_new->magic, CACHEMAGIC_NEW, sizeof CACHEMAGIC_NEW - 1)
 161           || memcmp (cache_new->version, CACHE_VERSION,
 162                       sizeof CACHE_VERSION - 1))
 163         error (EXIT_FAILURE, 0, _("File is not a cache file.\n"));
 164       format = 1;
 165       /* This is where the strings start.  */
 166       cache_data = (const char *) cache_new;
 167     }
 168   else
 169     {
 170       size_t offset = ALIGN_CACHE (sizeof (struct cache_file)
 171                                    + (cache->nlibs
 172                                       * sizeof (struct file_entry)));
 173       /* This is where the strings start.  */
 174       cache_data = (const char *) &cache->libs[cache->nlibs];
 175
 176       /* Check for a new cache embedded in the old format.  */
 177       if (cache_size >
 178           (offset + sizeof (struct cache_file_new)))
 179         {
 180
 181           cache_new = (struct cache_file_new *) ((void *)cache + offset);
 182
 183           if (memcmp (cache_new->magic, CACHEMAGIC_NEW,
 184                       sizeof CACHEMAGIC_NEW - 1) == 0
 185               && memcmp (cache_new->version, CACHE_VERSION,
 186                          sizeof CACHE_VERSION - 1) == 0)
 187             {
 188               cache_data = (const char *) cache_new;
 189               format = 1;
 190             }
 191         }
 192     }
 193
 194   if (format == 0)
 195     {
 196       printf (_("%d libs found in cache `%s'\n"), cache->nlibs, cache_name);
 197
 198       /* Print everything.  */
 199       for (i = 0; i < cache->nlibs; i++)
 200         print_entry (cache_data + cache->libs[i].key,
 201                      cache->libs[i].flags, 0, 0,
 202                      cache_data + cache->libs[i].value);
 203     }
 204   else if (format == 1)
 205     {
 206       printf (_("%d libs found in cache `%s'\n"),
 207               cache_new->nlibs, cache_name);
 208
 209       /* Print everything.  */
 210       for (i = 0; i < cache_new->nlibs; i++)
 211         print_entry (cache_data + cache_new->libs[i].key,
 212                      cache_new->libs[i].flags,
 213                      cache_new->libs[i].osversion,
 214                      cache_new->libs[i].hwcap,
 215                      cache_data + cache_new->libs[i].value);
 216     }
 217   /* Cleanup.  */
 218   munmap (cache, cache_size);
 219   close (fd);
 220 }
 221
 222 /* Initialize cache data structures.  */
 223 void
 224 init_cache (void)
 225 {
 226   entries = NULL;
 227 }
 228
 229
 230
 231 static
 232 int compare (const struct cache_entry *e1, const struct cache_entry *e2)
 233 {
 234   int res;
 235
 236   /* We need to swap entries here to get the correct sort order.  */
 237   res = _dl_cache_libcmp (e2->lib, e1->lib);
 238   if (res == 0)
 239     {
 240       if (e1->flags < e2->flags)
 241         return 1;
 242       else if (e1->flags > e2->flags)
 243         return -1;
 244       /* Sort by most specific hwcap.  */
 245       else if (e2->bits_hwcap > e1->bits_hwcap)
 246         return 1;
 247       else if (e2->bits_hwcap < e1->bits_hwcap)
 248         return -1;
 249       else if (e2->hwcap > e1->hwcap)
 250         return 1;
 251       else if (e2->hwcap < e1->hwcap)
 252         return -1;
 253       if (e2->osversion > e1->osversion)
 254         return 1;
 255       if (e2->osversion < e1->osversion)
 256         return -1;
 257     }
 258   return res;
 259 }
 260
 261 /* Save the contents of the cache.  */
 262 void
 263 save_cache (const char *cache_name)
 264 {
 265   struct cache_entry *entry;
 266   int fd, idx_old, idx_new;
 267   size_t total_strlen, len;
 268   char *strings, *str, *temp_name;
 269   struct cache_file *file_entries = NULL;
 270   struct cache_file_new *file_entries_new = NULL;
 271   size_t file_entries_size = 0;
 272   size_t file_entries_new_size = 0;
 273   unsigned int str_offset;
 274   /* Number of cache entries.  */
 275   int cache_entry_count = 0;
 276   /* Number of normal cache entries.  */
 277   int cache_entry_old_count = 0;
 278   /* Pad for alignment of cache_file_new.  */
 279   size_t pad;
 280
 281   /* The cache entries are sorted already, save them in this order. */
 282
 283   /* Count the length of all strings.  */
 284   /* The old format doesn't contain hwcap entries and doesn't contain
 285      libraries in subdirectories with hwcaps entries.  Count therefore
 286      also all entries with hwcap == 0.  */
 287   total_strlen = 0;
 288   for (entry = entries; entry != NULL; entry = entry->next)
 289     {
 290       /* Account the final NULs.  */
 291       total_strlen += strlen (entry->lib) + strlen (entry->path) + 2;
 292       ++cache_entry_count;
 293       if (entry->hwcap == 0)
 294         ++cache_entry_old_count;
 295     }
 296
 297   /* Create the on disk cache structure.  */
 298   /* First an array for all strings.  */
 299   strings = (char *)xmalloc (total_strlen);
 300
 301   if (opt_format != 2)
 302     {
 303       /* And the list of all entries in the old format.  */
 304       file_entries_size = sizeof (struct cache_file)
 305         + cache_entry_old_count * sizeof (struct file_entry);
 306       file_entries = (struct cache_file *) xmalloc (file_entries_size);
 307
 308       /* Fill in the header.  */
 309       memset (file_entries, 0, sizeof (struct cache_file));
 310       memcpy (file_entries->magic, CACHEMAGIC, sizeof CACHEMAGIC - 1);
 311
 312       file_entries->nlibs = cache_entry_old_count;
 313     }
 314
 315   if (opt_format != 0)
 316     {
 317       /* And the list of all entries in the new format.  */
 318       file_entries_new_size = sizeof (struct cache_file_new)
 319         + cache_entry_count * sizeof (struct file_entry_new);
 320       file_entries_new =
 321         (struct cache_file_new *) xmalloc (file_entries_new_size);
 322
 323       /* Fill in the header.  */
 324       memset (file_entries_new, 0, sizeof (struct cache_file_new));
 325       memcpy (file_entries_new->magic, CACHEMAGIC_NEW,
 326               sizeof CACHEMAGIC_NEW - 1);
 327       memcpy (file_entries_new->version, CACHE_VERSION,
 328               sizeof CACHE_VERSION - 1);
 329
 330       file_entries_new->nlibs = cache_entry_count;
 331       file_entries_new->len_strings = total_strlen;
 332     }
 333
 334   pad = ALIGN_CACHE (file_entries_size) - file_entries_size;
 335
 336   /* If we have both formats, we hide the new format in the strings
 337      table, we have to adjust all string indices for this so that
 338      old libc5/glibc 2 dynamic linkers just ignore them.  */
 339   if (opt_format != 0)
 340     str_offset = file_entries_new_size;
 341   else
 342     str_offset = 0;
 343
 344   str = strings;
 345   for (idx_old = 0, idx_new = 0, entry = entries; entry != NULL;
 346        entry = entry->next, ++idx_new)
 347     {
 348       /* First the library.  */
 349       if (opt_format != 2)
 350         {
 351           file_entries->libs[idx_old].flags = entry->flags;
 352           /* XXX: Actually we can optimize here and remove duplicates.  */
 353           file_entries->libs[idx_old].key = str_offset + pad;
 354         }
 355       if (opt_format != 0)
 356         {
 357           /* We could subtract file_entries_new_size from str_offset -
 358              not doing so makes the code easier, the string table
 359              always begins at the beginning of the the new cache
 360              struct.  */
 361           file_entries_new->libs[idx_new].flags = entry->flags;
 362           file_entries_new->libs[idx_new].osversion = entry->osversion;
 363           file_entries_new->libs[idx_new].hwcap = entry->hwcap;
 364           file_entries_new->libs[idx_new].key = str_offset;
 365         }
 366       len = strlen (entry->lib);
 367       str = stpcpy (str, entry->lib);
 368       /* Account the final NUL.  */
 369       ++str;
 370       str_offset += len + 1;
 371       /* Then the path.  */
 372       if (opt_format != 2)
 373         file_entries->libs[idx_old].value = str_offset + pad;
 374       if (opt_format != 0)
 375         file_entries_new->libs[idx_new].value = str_offset;
 376       len = strlen (entry->path);
 377       str = stpcpy (str, entry->path);
 378       /* Account the final NUL.  */
 379       ++str;
 380       str_offset += len + 1;
 381       /* Ignore entries with hwcap for old format.  */
 382       if (entry->hwcap == 0)
 383         ++idx_old;
 384     }
 385
 386   /* Write out the cache.  */
 387
 388   /* Write cache first to a temporary file and rename it later.  */
 389   temp_name = xmalloc (strlen (cache_name) + 2);
 390   sprintf (temp_name, "%s~", cache_name);
 391   /* First remove an old copy if it exists.  */
 392   if (unlink (temp_name) && errno != ENOENT)
 393     error (EXIT_FAILURE, errno, _("Can't remove old temporary cache file %s"),
 394            temp_name);
 395
 396   /* Create file.  */
 397   fd = open (temp_name, O_CREAT|O_WRONLY|O_TRUNC|O_NOFOLLOW,
 398              S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 399   if (fd < 0)
 400     error (EXIT_FAILURE, errno, _("Can't create temporary cache file %s"),
 401            temp_name);
 402
 403   /* Write contents.  */
 404   if (opt_format != 2)
 405     {
 406       if (write (fd, file_entries, file_entries_size)
 407           != (ssize_t)file_entries_size)
 408         error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 409     }
 410   if (opt_format != 0)
 411     {
 412       /* Align cache.  */
 413       if (opt_format != 2)
 414         {
 415           char zero[pad];
 416           if (write (fd, zero, pad) != (ssize_t)pad)
 417             error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 418         }
 419       if (write (fd, file_entries_new, file_entries_new_size)
 420           != (ssize_t)file_entries_new_size)
 421         error (EXIT_FAILURE, errno, _("Writing of cache data failed"));
 422     }
 423
 424   if (write (fd, strings, total_strlen) != (ssize_t)total_strlen)
 425     error (EXIT_FAILURE, errno, _("Writing of cache data failed."));
 426
 427   close (fd);
 428
 429   /* Make sure user can always read cache file */
 430   if (chmod (temp_name, S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR))
 431     error (EXIT_FAILURE, errno,
 432            _("Changing access rights of %s to %#o failed"), temp_name,
 433            S_IROTH|S_IRGRP|S_IRUSR|S_IWUSR);
 434
 435   /* Move temporary to its final location.  */
 436   if (rename (temp_name, cache_name))
 437     error (EXIT_FAILURE, errno, _("Renaming of %s to %s failed"), temp_name,
 438            cache_name);
 439
 440   /* Free all allocated memory.  */
 441   free (file_entries);
 442   free (strings);
 443
 444   while (entries)
 445     {
 446       entry = entries;
 447       free (entry->path);
 448       free (entry->lib);
 449       entries = entries->next;
 450       free (entry);
 451     }
 452 }
 453
 454
 455 /* Add one library to the cache.  */
 456 void
 457 add_to_cache (const char *path, const char *lib, int flags,
 458               unsigned int osversion, uint64_t hwcap)
 459 {
 460   struct cache_entry *new_entry, *ptr, *prev;
 461   char *full_path;
 462   int len, i;
 463
 464   new_entry = (struct cache_entry *) xmalloc (sizeof (struct cache_entry));
 465
 466   len = strlen (lib) + strlen (path) + 2;
 467
 468   full_path = (char *) xmalloc (len);
 469   snprintf (full_path, len, "%s/%s", path, lib);
 470
 471   new_entry->lib = xstrdup (lib);
 472   new_entry->path = full_path;
 473   new_entry->flags = flags;
 474   new_entry->osversion = osversion;
 475   new_entry->hwcap = hwcap;
 476   new_entry->bits_hwcap = 0;
 477
 478   /* Count the number of bits set in the masked value.  */
 479   for (i = 0; (~((1ULL << i) - 1) & hwcap) != 0; ++i)
 480     if ((hwcap & (1ULL << i)) != 0)
 481       ++new_entry->bits_hwcap;
 482
 483
 484   /* Keep the list sorted - search for right place to insert.  */
 485   ptr = entries;
 486   prev = entries;
 487   while (ptr != NULL)
 488     {
 489       if (compare (ptr, new_entry) > 0)
 490         break;
 491       prev = ptr;
 492       ptr = ptr->next;
 493     }
 494   /* Is this the first entry?  */
 495   if (ptr == entries)
 496     {
 497       new_entry->next = entries;
 498       entries = new_entry;
 499     }
 500   else
 501     {
 502       new_entry->next = prev->next;
 503       prev->next = new_entry;
 504     }
 505 }