fs/partitions/efi.c

   1 /************************************************************
   2  * EFI GUID Partition Table handling
   3  * Per Intel EFI Specification v1.02
   4  * http://developer.intel.com/technology/efi/efi.htm
   5  * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com>
   6  *   Copyright 2000,2001,2002,2004 Dell Inc.
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  *
  23  * TODO:
  24  *
  25  * Changelog:
  26  * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com>
  27  * - test for valid PMBR and valid PGPT before ever reading
  28  *   AGPT, allow override with 'gpt' kernel command line option.
  29  * - check for first/last_usable_lba outside of size of disk
  30  *
  31  * Tue  Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com>
  32  * - Ported to 2.5.7-pre1 and 2.5.7-dj2
  33  * - Applied patch to avoid fault in alternate header handling
  34  * - cleaned up find_valid_gpt
  35  * - On-disk structure and copy in memory is *always* LE now -
  36  *   swab fields as needed
  37  * - remove print_gpt_header()
  38  * - only use first max_p partition entries, to keep the kernel minor number
  39  *   and partition numbers tied.
  40  *
  41  * Mon  Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com>
  42  * - Removed __PRIPTR_PREFIX - not being used
  43  *
  44  * Mon  Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com>
  45  * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied
  46  *
  47  * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com>
  48  * - Added compare_gpts().
  49  * - moved le_efi_guid_to_cpus() back into this file.  GPT is the only
  50  *   thing that keeps EFI GUIDs on disk.
  51  * - Changed gpt structure names and members to be simpler and more Linux-like.
  52  *
  53  * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com>
  54  * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck
  55  *
  56  * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com>
  57  * - Changed function comments to DocBook style per Andreas Dilger suggestion.
  58  *
  59  * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com>
  60  * - Change read_lba() to use the page cache per Al Viro's work.
  61  * - print u64s properly on all architectures
  62  * - fixed debug_printk(), now Dprintk()
  63  *
  64  * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com>
  65  * - Style cleanups
  66  * - made most functions static
  67  * - Endianness addition
  68  * - remove test for second alternate header, as it's not per spec,
  69  *   and is unnecessary.  There's now a method to read/write the last
  70  *   sector of an odd-sized disk from user space.  No tools have ever
  71  *   been released which used this code, so it's effectively dead.
  72  * - Per Asit Mallick of Intel, added a test for a valid PMBR.
  73  * - Added kernel command line option 'gpt' to override valid PMBR test.
  74  *
  75  * Wed Jun  6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com>
  76  * - added devfs volume UUID support (/dev/volumes/uuids) for
  77  *   mounting file systems by the partition GUID.
  78  *
  79  * Tue Dec  5 2000 Matt Domsch <Matt_Domsch@dell.com>
  80  * - Moved crc32() to linux/lib, added efi_crc32().
  81  *
  82  * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com>
  83  * - Replaced Intel's CRC32 function with an equivalent
  84  *   non-license-restricted version.
  85  *
  86  * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com>
  87  * - Fixed the last_lba() call to return the proper last block
  88  *
  89  * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com>
  90  * - Thanks to Andries Brouwer for his debugging assistance.
  91  * - Code works, detects all the partitions.
  92  *
  93  ************************************************************/
  94 #include <linux/crc32.h>
  95 #include "check.h"
  96 #include "efi.h"
  97
  98 #undef EFI_DEBUG
  99 #ifdef EFI_DEBUG
 100 #define Dprintk(x...) printk(KERN_DEBUG x)
 101 #else
 102 #define Dprintk(x...)
 103 #endif
 104
 105 /* This allows a kernel command line option 'gpt' to override
 106  * the test for invalid PMBR.  Not __initdata because reloading
 107  * the partition tables happens after init too.
 108  */
 109 static int force_gpt;
 110 static int __init
 111 force_gpt_fn(char *str)
 112 {
 113         force_gpt = 1;
 114         return 1;
 115 }
 116 __setup("gpt", force_gpt_fn);
 117
 118
 119 /**
 120  * efi_crc32() - EFI version of crc32 function
 121  * @buf: buffer to calculate crc32 of
 122  * @len - length of buf
 123  *
 124  * Description: Returns EFI-style CRC32 value for @buf
 125  *
 126  * This function uses the little endian Ethernet polynomial
 127  * but seeds the function with ~0, and xor's with ~0 at the end.
 128  * Note, the EFI Specification, v1.02, has a reference to
 129  * Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
 130  */
 131 static inline u32
 132 efi_crc32(const void *buf, unsigned long len)
 133 {
 134         return (crc32(~0L, buf, len) ^ ~0L);
 135 }
 136
 137 /**
 138  * last_lba(): return number of last logical block of device
 139  * @bdev: block device
 140  *
 141  * Description: Returns last LBA value on success, 0 on error.
 142  * This is stored (by sd and ide-geometry) in
 143  *  the part[0] entry for this disk, and is the number of
 144  *  physical sectors available on the disk.
 145  */
 146 static u64
 147 last_lba(struct block_device *bdev)
 148 {
 149         if (!bdev || !bdev->bd_inode)
 150                 return 0;
 151         return (bdev->bd_inode->i_size >> 9) - 1ULL;
 152 }
 153
 154 static inline int
 155 pmbr_part_valid(struct partition *part)
 156 {
 157         if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
 158             le32_to_cpu(part->start_sect) == 1UL)
 159                 return 1;
 160         return 0;
 161 }
 162
 163 /**
 164  * is_pmbr_valid(): test Protective MBR for validity
 165  * @mbr: pointer to a legacy mbr structure
 166  *
 167  * Description: Returns 1 if PMBR is valid, 0 otherwise.
 168  * Validity depends on two things:
 169  *  1) MSDOS signature is in the last two bytes of the MBR
 170  *  2) One partition of type 0xEE is found
 171  */
 172 static int
 173 is_pmbr_valid(legacy_mbr *mbr)
 174 {
 175         int i;
 176         if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
 177                 return 0;
 178         for (i = 0; i < 4; i++)
 179                 if (pmbr_part_valid(&mbr->partition_record[i]))
 180                         return 1;
 181         return 0;
 182 }
 183
 184 /**
 185  * read_lba(): Read bytes from disk, starting at given LBA
 186  * @bdev
 187  * @lba
 188  * @buffer
 189  * @size_t
 190  *
 191  * Description:  Reads @count bytes from @bdev into @buffer.
 192  * Returns number of bytes read on success, 0 on error.
 193  */
 194 static size_t
 195 read_lba(struct block_device *bdev, u64 lba, u8 * buffer, size_t count)
 196 {
 197         size_t totalreadcount = 0;
 198
 199         if (!bdev || !buffer || lba > last_lba(bdev))
 200                 return 0;
 201
 202         while (count) {
 203                 int copied = 512;
 204                 Sector sect;
 205                 unsigned char *data = read_dev_sector(bdev, lba++, &sect);
 206                 if (!data)
 207                         break;
 208                 if (copied > count)
 209                         copied = count;
 210                 memcpy(buffer, data, copied);
 211                 put_dev_sector(sect);
 212                 buffer += copied;
 213                 totalreadcount +=copied;
 214                 count -= copied;
 215         }
 216         return totalreadcount;
 217 }
 218
 219 /**
 220  * alloc_read_gpt_entries(): reads partition entries from disk
 221  * @bdev
 222  * @gpt - GPT header
 223  *
 224  * Description: Returns ptes on success,  NULL on error.
 225  * Allocates space for PTEs based on information found in @gpt.
 226  * Notes: remember to free pte when you're done!
 227  */
 228 static gpt_entry *
 229 alloc_read_gpt_entries(struct block_device *bdev, gpt_header *gpt)
 230 {
 231         size_t count;
 232         gpt_entry *pte;
 233         if (!bdev || !gpt)
 234                 return NULL;
 235
 236         count = le32_to_cpu(gpt->num_partition_entries) *
 237                 le32_to_cpu(gpt->sizeof_partition_entry);
 238         if (!count)
 239                 return NULL;
 240         pte = kzalloc(count, GFP_KERNEL);
 241         if (!pte)
 242                 return NULL;
 243
 244         if (read_lba(bdev, le64_to_cpu(gpt->partition_entry_lba),
 245                      (u8 *) pte,
 246                      count) < count) {
 247                 kfree(pte);
 248                 pte=NULL;
 249                 return NULL;
 250         }
 251         return pte;
 252 }
 253
 254 /**
 255  * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
 256  * @bdev
 257  * @lba is the Logical Block Address of the partition table
 258  *
 259  * Description: returns GPT header on success, NULL on error.   Allocates
 260  * and fills a GPT header starting at @ from @bdev.
 261  * Note: remember to free gpt when finished with it.
 262  */
 263 static gpt_header *
 264 alloc_read_gpt_header(struct block_device *bdev, u64 lba)
 265 {
 266         gpt_header *gpt;
 267         if (!bdev)
 268                 return NULL;
 269
 270         gpt = kzalloc(sizeof (gpt_header), GFP_KERNEL);
 271         if (!gpt)
 272                 return NULL;
 273
 274         if (read_lba(bdev, lba, (u8 *) gpt,
 275                      sizeof (gpt_header)) < sizeof (gpt_header)) {
 276                 kfree(gpt);
 277                 gpt=NULL;
 278                 return NULL;
 279         }
 280
 281         return gpt;
 282 }
 283
 284 /**
 285  * is_gpt_valid() - tests one GPT header and PTEs for validity
 286  * @bdev
 287  * @lba is the logical block address of the GPT header to test
 288  * @gpt is a GPT header ptr, filled on return.
 289  * @ptes is a PTEs ptr, filled on return.
 290  *
 291  * Description: returns 1 if valid,  0 on error.
 292  * If valid, returns pointers to newly allocated GPT header and PTEs.
 293  */
 294 static int
 295 is_gpt_valid(struct block_device *bdev, u64 lba,
 296              gpt_header **gpt, gpt_entry **ptes)
 297 {
 298         u32 crc, origcrc;
 299         u64 lastlba;
 300
 301         if (!bdev || !gpt || !ptes)
 302                 return 0;
 303         if (!(*gpt = alloc_read_gpt_header(bdev, lba)))
 304                 return 0;
 305
 306         /* Check the GUID Partition Table signature */
 307         if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
 308                 Dprintk("GUID Partition Table Header signature is wrong:"
 309                         "%lld != %lld\n",
 310                         (unsigned long long)le64_to_cpu((*gpt)->signature),
 311                         (unsigned long long)GPT_HEADER_SIGNATURE);
 312                 goto fail;
 313         }
 314
 315         /* Check the GUID Partition Table CRC */
 316         origcrc = le32_to_cpu((*gpt)->header_crc32);
 317         (*gpt)->header_crc32 = 0;
 318         crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
 319
 320         if (crc != origcrc) {
 321                 Dprintk
 322                     ("GUID Partition Table Header CRC is wrong: %x != %x\n",
 323                      crc, origcrc);
 324                 goto fail;
 325         }
 326         (*gpt)->header_crc32 = cpu_to_le32(origcrc);
 327
 328         /* Check that the my_lba entry points to the LBA that contains
 329          * the GUID Partition Table */
 330         if (le64_to_cpu((*gpt)->my_lba) != lba) {
 331                 Dprintk("GPT my_lba incorrect: %lld != %lld\n",
 332                         (unsigned long long)le64_to_cpu((*gpt)->my_lba),
 333                         (unsigned long long)lba);
 334                 goto fail;
 335         }
 336
 337         /* Check the first_usable_lba and last_usable_lba are
 338          * within the disk.
 339          */
 340         lastlba = last_lba(bdev);
 341         if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
 342                 Dprintk("GPT: first_usable_lba incorrect: %lld > %lld\n",
 343                         (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
 344                         (unsigned long long)lastlba);
 345                 goto fail;
 346         }
 347         if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
 348                 Dprintk("GPT: last_usable_lba incorrect: %lld > %lld\n",
 349                         (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
 350                         (unsigned long long)lastlba);
 351                 goto fail;
 352         }
 353
 354         if (!(*ptes = alloc_read_gpt_entries(bdev, *gpt)))
 355                 goto fail;
 356
 357         /* Check the GUID Partition Entry Array CRC */
 358         crc = efi_crc32((const unsigned char *) (*ptes),
 359                         le32_to_cpu((*gpt)->num_partition_entries) *
 360                         le32_to_cpu((*gpt)->sizeof_partition_entry));
 361
 362         if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
 363                 Dprintk("GUID Partitition Entry Array CRC check failed.\n");
 364                 goto fail_ptes;
 365         }
 366
 367         /* We're done, all's well */
 368         return 1;
 369
 370  fail_ptes:
 371         kfree(*ptes);
 372         *ptes = NULL;
 373  fail:
 374         kfree(*gpt);
 375         *gpt = NULL;
 376         return 0;
 377 }
 378
 379 /**
 380  * is_pte_valid() - tests one PTE for validity
 381  * @pte is the pte to check
 382  * @lastlba is last lba of the disk
 383  *
 384  * Description: returns 1 if valid,  0 on error.
 385  */
 386 static inline int
 387 is_pte_valid(const gpt_entry *pte, const u64 lastlba)
 388 {
 389         if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
 390             le64_to_cpu(pte->starting_lba) > lastlba         ||
 391             le64_to_cpu(pte->ending_lba)   > lastlba)
 392                 return 0;
 393         return 1;
 394 }
 395
 396 /**
 397  * compare_gpts() - Search disk for valid GPT headers and PTEs
 398  * @pgpt is the primary GPT header
 399  * @agpt is the alternate GPT header
 400  * @lastlba is the last LBA number
 401  * Description: Returns nothing.  Sanity checks pgpt and agpt fields
 402  * and prints warnings on discrepancies.
 403  *
 404  */
 405 static void
 406 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
 407 {
 408         int error_found = 0;
 409         if (!pgpt || !agpt)
 410                 return;
 411         if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
 412                 printk(KERN_WARNING
 413                        "GPT:Primary header LBA != Alt. header alternate_lba\n");
 414                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 415                        (unsigned long long)le64_to_cpu(pgpt->my_lba),
 416                        (unsigned long long)le64_to_cpu(agpt->alternate_lba));
 417                 error_found++;
 418         }
 419         if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
 420                 printk(KERN_WARNING
 421                        "GPT:Primary header alternate_lba != Alt. header my_lba\n");
 422                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 423                        (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
 424                        (unsigned long long)le64_to_cpu(agpt->my_lba));
 425                 error_found++;
 426         }
 427         if (le64_to_cpu(pgpt->first_usable_lba) !=
 428             le64_to_cpu(agpt->first_usable_lba)) {
 429                 printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n");
 430                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 431                        (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
 432                        (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
 433                 error_found++;
 434         }
 435         if (le64_to_cpu(pgpt->last_usable_lba) !=
 436             le64_to_cpu(agpt->last_usable_lba)) {
 437                 printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n");
 438                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 439                        (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
 440                        (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
 441                 error_found++;
 442         }
 443         if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
 444                 printk(KERN_WARNING "GPT:disk_guids don't match.\n");
 445                 error_found++;
 446         }
 447         if (le32_to_cpu(pgpt->num_partition_entries) !=
 448             le32_to_cpu(agpt->num_partition_entries)) {
 449                 printk(KERN_WARNING "GPT:num_partition_entries don't match: "
 450                        "0x%x != 0x%x\n",
 451                        le32_to_cpu(pgpt->num_partition_entries),
 452                        le32_to_cpu(agpt->num_partition_entries));
 453                 error_found++;
 454         }
 455         if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
 456             le32_to_cpu(agpt->sizeof_partition_entry)) {
 457                 printk(KERN_WARNING
 458                        "GPT:sizeof_partition_entry values don't match: "
 459                        "0x%x != 0x%x\n",
 460                        le32_to_cpu(pgpt->sizeof_partition_entry),
 461                        le32_to_cpu(agpt->sizeof_partition_entry));
 462                 error_found++;
 463         }
 464         if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
 465             le32_to_cpu(agpt->partition_entry_array_crc32)) {
 466                 printk(KERN_WARNING
 467                        "GPT:partition_entry_array_crc32 values don't match: "
 468                        "0x%x != 0x%x\n",
 469                        le32_to_cpu(pgpt->partition_entry_array_crc32),
 470                        le32_to_cpu(agpt->partition_entry_array_crc32));
 471                 error_found++;
 472         }
 473         if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
 474                 printk(KERN_WARNING
 475                        "GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
 476                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 477                         (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
 478                         (unsigned long long)lastlba);
 479                 error_found++;
 480         }
 481
 482         if (le64_to_cpu(agpt->my_lba) != lastlba) {
 483                 printk(KERN_WARNING
 484                        "GPT:Alternate GPT header not at the end of the disk.\n");
 485                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 486                         (unsigned long long)le64_to_cpu(agpt->my_lba),
 487                         (unsigned long long)lastlba);
 488                 error_found++;
 489         }
 490
 491         if (error_found)
 492                 printk(KERN_WARNING
 493                        "GPT: Use GNU Parted to correct GPT errors.\n");
 494         return;
 495 }
 496
 497 /**
 498  * find_valid_gpt() - Search disk for valid GPT headers and PTEs
 499  * @bdev
 500  * @gpt is a GPT header ptr, filled on return.
 501  * @ptes is a PTEs ptr, filled on return.
 502  * Description: Returns 1 if valid, 0 on error.
 503  * If valid, returns pointers to newly allocated GPT header and PTEs.
 504  * Validity depends on PMBR being valid (or being overridden by the
 505  * 'gpt' kernel command line option) and finding either the Primary
 506  * GPT header and PTEs valid, or the Alternate GPT header and PTEs
 507  * valid.  If the Primary GPT header is not valid, the Alternate GPT header
 508  * is not checked unless the 'gpt' kernel command line option is passed.
 509  * This protects against devices which misreport their size, and forces
 510  * the user to decide to use the Alternate GPT.
 511  */
 512 static int
 513 find_valid_gpt(struct block_device *bdev, gpt_header **gpt, gpt_entry **ptes)
 514 {
 515         int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
 516         gpt_header *pgpt = NULL, *agpt = NULL;
 517         gpt_entry *pptes = NULL, *aptes = NULL;
 518         legacy_mbr *legacymbr;
 519         u64 lastlba;
 520         if (!bdev || !gpt || !ptes)
 521                 return 0;
 522
 523         lastlba = last_lba(bdev);
 524         if (!force_gpt) {
 525                 /* This will be added to the EFI Spec. per Intel after v1.02. */
 526                 legacymbr = kzalloc(sizeof (*legacymbr), GFP_KERNEL);
 527                 if (legacymbr) {
 528                         read_lba(bdev, 0, (u8 *) legacymbr,
 529                                  sizeof (*legacymbr));
 530                         good_pmbr = is_pmbr_valid(legacymbr);
 531                         kfree(legacymbr);
 532                 }
 533                 if (!good_pmbr)
 534                         goto fail;
 535         }
 536
 537         good_pgpt = is_gpt_valid(bdev, GPT_PRIMARY_PARTITION_TABLE_LBA,
 538                                  &pgpt, &pptes);
 539         if (good_pgpt)
 540                 good_agpt = is_gpt_valid(bdev,
 541                                          le64_to_cpu(pgpt->alternate_lba),
 542                                          &agpt, &aptes);
 543         if (!good_agpt && force_gpt)
 544                 good_agpt = is_gpt_valid(bdev, lastlba,
 545                                          &agpt, &aptes);
 546
 547         /* The obviously unsuccessful case */
 548         if (!good_pgpt && !good_agpt)
 549                 goto fail;
 550
 551         compare_gpts(pgpt, agpt, lastlba);
 552
 553         /* The good cases */
 554         if (good_pgpt) {
 555                 *gpt  = pgpt;
 556                 *ptes = pptes;
 557                 kfree(agpt);
 558                 kfree(aptes);
 559                 if (!good_agpt) {
 560                         printk(KERN_WARNING
 561                                "Alternate GPT is invalid, "
 562                                "using primary GPT.\n");
 563                 }
 564                 return 1;
 565         }
 566         else if (good_agpt) {
 567                 *gpt  = agpt;
 568                 *ptes = aptes;
 569                 kfree(pgpt);
 570                 kfree(pptes);
 571                 printk(KERN_WARNING
 572                        "Primary GPT is invalid, using alternate GPT.\n");
 573                 return 1;
 574         }
 575
 576  fail:
 577         kfree(pgpt);
 578         kfree(agpt);
 579         kfree(pptes);
 580         kfree(aptes);
 581         *gpt = NULL;
 582         *ptes = NULL;
 583         return 0;
 584 }
 585
 586 /**
 587  * efi_partition(struct parsed_partitions *state, struct block_device *bdev)
 588  * @state
 589  * @bdev
 590  *
 591  * Description: called from check.c, if the disk contains GPT
 592  * partitions, sets up partition entries in the kernel.
 593  *
 594  * If the first block on the disk is a legacy MBR,
 595  * it will get handled by msdos_partition().
 596  * If it's a Protective MBR, we'll handle it here.
 597  *
 598  * We do not create a Linux partition for GPT, but
 599  * only for the actual data partitions.
 600  * Returns:
 601  * -1 if unable to read the partition table
 602  *  0 if this isn't our partition table
 603  *  1 if successful
 604  *
 605  */
 606 int
 607 efi_partition(struct parsed_partitions *state, struct block_device *bdev)
 608 {
 609         gpt_header *gpt = NULL;
 610         gpt_entry *ptes = NULL;
 611         u32 i;
 612
 613         if (!find_valid_gpt(bdev, &gpt, &ptes) || !gpt || !ptes) {
 614                 kfree(gpt);
 615                 kfree(ptes);
 616                 return 0;
 617         }
 618
 619         Dprintk("GUID Partition Table is valid!  Yea!\n");
 620
 621         for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
 622                 if (!is_pte_valid(&ptes[i], last_lba(bdev)))
 623                         continue;
 624
 625                 put_partition(state, i+1, le64_to_cpu(ptes[i].starting_lba),
 626                                  (le64_to_cpu(ptes[i].ending_lba) -
 627                                   le64_to_cpu(ptes[i].starting_lba) +
 628                                   1ULL));
 629
 630                 /* If this is a RAID volume, tell md */
 631                 if (!efi_guidcmp(ptes[i].partition_type_guid,
 632                                  PARTITION_LINUX_RAID_GUID))
 633                         state->parts[i+1].flags = 1;
 634         }
 635         kfree(ptes);
 636         kfree(gpt);
 637         printk("\n");
 638         return 1;
 639 }