block/partitions/efi.c

   1 /************************************************************
   2  * EFI GUID Partition Table handling
   3  *
   4  * http://www.uefi.org/specs/
   5  * http://www.intel.com/technology/efi/
   6  *
   7  * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com>
   8  *   Copyright 2000,2001,2002,2004 Dell Inc.
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  *
  24  *
  25  * TODO:
  26  *
  27  * Changelog:
  28  * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com>
  29  * - test for valid PMBR and valid PGPT before ever reading
  30  *   AGPT, allow override with 'gpt' kernel command line option.
  31  * - check for first/last_usable_lba outside of size of disk
  32  *
  33  * Tue  Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com>
  34  * - Ported to 2.5.7-pre1 and 2.5.7-dj2
  35  * - Applied patch to avoid fault in alternate header handling
  36  * - cleaned up find_valid_gpt
  37  * - On-disk structure and copy in memory is *always* LE now -
  38  *   swab fields as needed
  39  * - remove print_gpt_header()
  40  * - only use first max_p partition entries, to keep the kernel minor number
  41  *   and partition numbers tied.
  42  *
  43  * Mon  Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com>
  44  * - Removed __PRIPTR_PREFIX - not being used
  45  *
  46  * Mon  Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com>
  47  * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied
  48  *
  49  * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com>
  50  * - Added compare_gpts().
  51  * - moved le_efi_guid_to_cpus() back into this file.  GPT is the only
  52  *   thing that keeps EFI GUIDs on disk.
  53  * - Changed gpt structure names and members to be simpler and more Linux-like.
  54  *
  55  * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com>
  56  * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck
  57  *
  58  * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com>
  59  * - Changed function comments to DocBook style per Andreas Dilger suggestion.
  60  *
  61  * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com>
  62  * - Change read_lba() to use the page cache per Al Viro's work.
  63  * - print u64s properly on all architectures
  64  * - fixed debug_printk(), now Dprintk()
  65  *
  66  * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com>
  67  * - Style cleanups
  68  * - made most functions static
  69  * - Endianness addition
  70  * - remove test for second alternate header, as it's not per spec,
  71  *   and is unnecessary.  There's now a method to read/write the last
  72  *   sector of an odd-sized disk from user space.  No tools have ever
  73  *   been released which used this code, so it's effectively dead.
  74  * - Per Asit Mallick of Intel, added a test for a valid PMBR.
  75  * - Added kernel command line option 'gpt' to override valid PMBR test.
  76  *
  77  * Wed Jun  6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com>
  78  * - added devfs volume UUID support (/dev/volumes/uuids) for
  79  *   mounting file systems by the partition GUID.
  80  *
  81  * Tue Dec  5 2000 Matt Domsch <Matt_Domsch@dell.com>
  82  * - Moved crc32() to linux/lib, added efi_crc32().
  83  *
  84  * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com>
  85  * - Replaced Intel's CRC32 function with an equivalent
  86  *   non-license-restricted version.
  87  *
  88  * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com>
  89  * - Fixed the last_lba() call to return the proper last block
  90  *
  91  * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com>
  92  * - Thanks to Andries Brouwer for his debugging assistance.
  93  * - Code works, detects all the partitions.
  94  *
  95  ************************************************************/
  96 #include <linux/crc32.h>
  97 #include <linux/ctype.h>
  98 #include <linux/math64.h>
  99 #include <linux/slab.h>
 100 #include "check.h"
 101 #include "efi.h"
 102
 103 /* This allows a kernel command line option 'gpt' to override
 104  * the test for invalid PMBR.  Not __initdata because reloading
 105  * the partition tables happens after init too.
 106  */
 107 static int force_gpt;
 108 static int __init
 109 force_gpt_fn(char *str)
 110 {
 111         force_gpt = 1;
 112         return 1;
 113 }
 114 __setup("gpt", force_gpt_fn);
 115
 116
 117 /**
 118  * efi_crc32() - EFI version of crc32 function
 119  * @buf: buffer to calculate crc32 of
 120  * @len - length of buf
 121  *
 122  * Description: Returns EFI-style CRC32 value for @buf
 123  *
 124  * This function uses the little endian Ethernet polynomial
 125  * but seeds the function with ~0, and xor's with ~0 at the end.
 126  * Note, the EFI Specification, v1.02, has a reference to
 127  * Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
 128  */
 129 static inline u32
 130 efi_crc32(const void *buf, unsigned long len)
 131 {
 132         return (crc32(~0L, buf, len) ^ ~0L);
 133 }
 134
 135 /**
 136  * last_lba(): return number of last logical block of device
 137  * @bdev: block device
 138  *
 139  * Description: Returns last LBA value on success, 0 on error.
 140  * This is stored (by sd and ide-geometry) in
 141  *  the part[0] entry for this disk, and is the number of
 142  *  physical sectors available on the disk.
 143  */
 144 static u64 last_lba(struct block_device *bdev)
 145 {
 146         if (!bdev || !bdev->bd_inode)
 147                 return 0;
 148         return div_u64(bdev->bd_inode->i_size,
 149                        bdev_logical_block_size(bdev)) - 1ULL;
 150 }
 151
 152 static inline int pmbr_part_valid(gpt_mbr_record *part)
 153 {
 154         if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT)
 155                 goto invalid;
 156
 157         /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */
 158         if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA)
 159                 goto invalid;
 160
 161         if (le32_to_cpu(part->start_sector) != 1UL)
 162                 goto invalid;
 163
 164         return 1;
 165 invalid:
 166         return 0;
 167 }
 168
 169 /**
 170  * is_pmbr_valid(): test Protective MBR for validity
 171  * @mbr: pointer to a legacy mbr structure
 172  *
 173  * Description: Returns 1 if PMBR is valid, 0 otherwise.
 174  * Validity depends on two things:
 175  *  1) MSDOS signature is in the last two bytes of the MBR
 176  *  2) One partition of type 0xEE is found
 177  */
 178 static int
 179 is_pmbr_valid(legacy_mbr *mbr)
 180 {
 181         int i;
 182         if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
 183                 return 0;
 184         for (i = 0; i < 4; i++)
 185                 if (pmbr_part_valid(&mbr->partition_record[i]))
 186                         return 1;
 187         return 0;
 188 }
 189
 190 /**
 191  * read_lba(): Read bytes from disk, starting at given LBA
 192  * @state
 193  * @lba
 194  * @buffer
 195  * @size_t
 196  *
 197  * Description: Reads @count bytes from @state->bdev into @buffer.
 198  * Returns number of bytes read on success, 0 on error.
 199  */
 200 static size_t read_lba(struct parsed_partitions *state,
 201                        u64 lba, u8 *buffer, size_t count)
 202 {
 203         size_t totalreadcount = 0;
 204         struct block_device *bdev = state->bdev;
 205         sector_t n = lba * (bdev_logical_block_size(bdev) / 512);
 206
 207         if (!buffer || lba > last_lba(bdev))
 208                 return 0;
 209
 210         while (count) {
 211                 int copied = 512;
 212                 Sector sect;
 213                 unsigned char *data = read_part_sector(state, n++, &sect);
 214                 if (!data)
 215                         break;
 216                 if (copied > count)
 217                         copied = count;
 218                 memcpy(buffer, data, copied);
 219                 put_dev_sector(sect);
 220                 buffer += copied;
 221                 totalreadcount +=copied;
 222                 count -= copied;
 223         }
 224         return totalreadcount;
 225 }
 226
 227 /**
 228  * alloc_read_gpt_entries(): reads partition entries from disk
 229  * @state
 230  * @gpt - GPT header
 231  *
 232  * Description: Returns ptes on success,  NULL on error.
 233  * Allocates space for PTEs based on information found in @gpt.
 234  * Notes: remember to free pte when you're done!
 235  */
 236 static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state,
 237                                          gpt_header *gpt)
 238 {
 239         size_t count;
 240         gpt_entry *pte;
 241
 242         if (!gpt)
 243                 return NULL;
 244
 245         count = le32_to_cpu(gpt->num_partition_entries) *
 246                 le32_to_cpu(gpt->sizeof_partition_entry);
 247         if (!count)
 248                 return NULL;
 249         pte = kmalloc(count, GFP_KERNEL);
 250         if (!pte)
 251                 return NULL;
 252
 253         if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
 254                      (u8 *) pte,
 255                      count) < count) {
 256                 kfree(pte);
 257                 pte=NULL;
 258                 return NULL;
 259         }
 260         return pte;
 261 }
 262
 263 /**
 264  * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
 265  * @state
 266  * @lba is the Logical Block Address of the partition table
 267  *
 268  * Description: returns GPT header on success, NULL on error.   Allocates
 269  * and fills a GPT header starting at @ from @state->bdev.
 270  * Note: remember to free gpt when finished with it.
 271  */
 272 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
 273                                          u64 lba)
 274 {
 275         gpt_header *gpt;
 276         unsigned ssz = bdev_logical_block_size(state->bdev);
 277
 278         gpt = kmalloc(ssz, GFP_KERNEL);
 279         if (!gpt)
 280                 return NULL;
 281
 282         if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
 283                 kfree(gpt);
 284                 gpt=NULL;
 285                 return NULL;
 286         }
 287
 288         return gpt;
 289 }
 290
 291 /**
 292  * is_gpt_valid() - tests one GPT header and PTEs for validity
 293  * @state
 294  * @lba is the logical block address of the GPT header to test
 295  * @gpt is a GPT header ptr, filled on return.
 296  * @ptes is a PTEs ptr, filled on return.
 297  *
 298  * Description: returns 1 if valid,  0 on error.
 299  * If valid, returns pointers to newly allocated GPT header and PTEs.
 300  */
 301 static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
 302                         gpt_header **gpt, gpt_entry **ptes)
 303 {
 304         u32 crc, origcrc;
 305         u64 lastlba;
 306
 307         if (!ptes)
 308                 return 0;
 309         if (!(*gpt = alloc_read_gpt_header(state, lba)))
 310                 return 0;
 311
 312         /* Check the GUID Partition Table signature */
 313         if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
 314                 pr_debug("GUID Partition Table Header signature is wrong:"
 315                          "%lld != %lld\n",
 316                          (unsigned long long)le64_to_cpu((*gpt)->signature),
 317                          (unsigned long long)GPT_HEADER_SIGNATURE);
 318                 goto fail;
 319         }
 320
 321         /* Check the GUID Partition Table header size is too big */
 322         if (le32_to_cpu((*gpt)->header_size) >
 323                         bdev_logical_block_size(state->bdev)) {
 324                 pr_debug("GUID Partition Table Header size is too large: %u > %u\n",
 325                         le32_to_cpu((*gpt)->header_size),
 326                         bdev_logical_block_size(state->bdev));
 327                 goto fail;
 328         }
 329
 330         /* Check the GUID Partition Table header size is too small */
 331         if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) {
 332                 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n",
 333                         le32_to_cpu((*gpt)->header_size),
 334                         sizeof(gpt_header));
 335                 goto fail;
 336         }
 337
 338         /* Check the GUID Partition Table CRC */
 339         origcrc = le32_to_cpu((*gpt)->header_crc32);
 340         (*gpt)->header_crc32 = 0;
 341         crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
 342
 343         if (crc != origcrc) {
 344                 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
 345                          crc, origcrc);
 346                 goto fail;
 347         }
 348         (*gpt)->header_crc32 = cpu_to_le32(origcrc);
 349
 350         /* Check that the my_lba entry points to the LBA that contains
 351          * the GUID Partition Table */
 352         if (le64_to_cpu((*gpt)->my_lba) != lba) {
 353                 pr_debug("GPT my_lba incorrect: %lld != %lld\n",
 354                          (unsigned long long)le64_to_cpu((*gpt)->my_lba),
 355                          (unsigned long long)lba);
 356                 goto fail;
 357         }
 358
 359         /* Check the first_usable_lba and last_usable_lba are
 360          * within the disk.
 361          */
 362         lastlba = last_lba(state->bdev);
 363         if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
 364                 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
 365                          (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
 366                          (unsigned long long)lastlba);
 367                 goto fail;
 368         }
 369         if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
 370                 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
 371                          (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
 372                          (unsigned long long)lastlba);
 373                 goto fail;
 374         }
 375
 376         /* Check that sizeof_partition_entry has the correct value */
 377         if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
 378                 pr_debug("GUID Partitition Entry Size check failed.\n");
 379                 goto fail;
 380         }
 381
 382         if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
 383                 goto fail;
 384
 385         /* Check the GUID Partition Entry Array CRC */
 386         crc = efi_crc32((const unsigned char *) (*ptes),
 387                         le32_to_cpu((*gpt)->num_partition_entries) *
 388                         le32_to_cpu((*gpt)->sizeof_partition_entry));
 389
 390         if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
 391                 pr_debug("GUID Partitition Entry Array CRC check failed.\n");
 392                 goto fail_ptes;
 393         }
 394
 395         /* We're done, all's well */
 396         return 1;
 397
 398  fail_ptes:
 399         kfree(*ptes);
 400         *ptes = NULL;
 401  fail:
 402         kfree(*gpt);
 403         *gpt = NULL;
 404         return 0;
 405 }
 406
 407 /**
 408  * is_pte_valid() - tests one PTE for validity
 409  * @pte is the pte to check
 410  * @lastlba is last lba of the disk
 411  *
 412  * Description: returns 1 if valid,  0 on error.
 413  */
 414 static inline int
 415 is_pte_valid(const gpt_entry *pte, const u64 lastlba)
 416 {
 417         if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
 418             le64_to_cpu(pte->starting_lba) > lastlba         ||
 419             le64_to_cpu(pte->ending_lba)   > lastlba)
 420                 return 0;
 421         return 1;
 422 }
 423
 424 /**
 425  * compare_gpts() - Search disk for valid GPT headers and PTEs
 426  * @pgpt is the primary GPT header
 427  * @agpt is the alternate GPT header
 428  * @lastlba is the last LBA number
 429  * Description: Returns nothing.  Sanity checks pgpt and agpt fields
 430  * and prints warnings on discrepancies.
 431  *
 432  */
 433 static void
 434 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
 435 {
 436         int error_found = 0;
 437         if (!pgpt || !agpt)
 438                 return;
 439         if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
 440                 printk(KERN_WARNING
 441                        "GPT:Primary header LBA != Alt. header alternate_lba\n");
 442                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 443                        (unsigned long long)le64_to_cpu(pgpt->my_lba),
 444                        (unsigned long long)le64_to_cpu(agpt->alternate_lba));
 445                 error_found++;
 446         }
 447         if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
 448                 printk(KERN_WARNING
 449                        "GPT:Primary header alternate_lba != Alt. header my_lba\n");
 450                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 451                        (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
 452                        (unsigned long long)le64_to_cpu(agpt->my_lba));
 453                 error_found++;
 454         }
 455         if (le64_to_cpu(pgpt->first_usable_lba) !=
 456             le64_to_cpu(agpt->first_usable_lba)) {
 457                 printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n");
 458                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 459                        (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
 460                        (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
 461                 error_found++;
 462         }
 463         if (le64_to_cpu(pgpt->last_usable_lba) !=
 464             le64_to_cpu(agpt->last_usable_lba)) {
 465                 printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n");
 466                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 467                        (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
 468                        (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
 469                 error_found++;
 470         }
 471         if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
 472                 printk(KERN_WARNING "GPT:disk_guids don't match.\n");
 473                 error_found++;
 474         }
 475         if (le32_to_cpu(pgpt->num_partition_entries) !=
 476             le32_to_cpu(agpt->num_partition_entries)) {
 477                 printk(KERN_WARNING "GPT:num_partition_entries don't match: "
 478                        "0x%x != 0x%x\n",
 479                        le32_to_cpu(pgpt->num_partition_entries),
 480                        le32_to_cpu(agpt->num_partition_entries));
 481                 error_found++;
 482         }
 483         if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
 484             le32_to_cpu(agpt->sizeof_partition_entry)) {
 485                 printk(KERN_WARNING
 486                        "GPT:sizeof_partition_entry values don't match: "
 487                        "0x%x != 0x%x\n",
 488                        le32_to_cpu(pgpt->sizeof_partition_entry),
 489                        le32_to_cpu(agpt->sizeof_partition_entry));
 490                 error_found++;
 491         }
 492         if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
 493             le32_to_cpu(agpt->partition_entry_array_crc32)) {
 494                 printk(KERN_WARNING
 495                        "GPT:partition_entry_array_crc32 values don't match: "
 496                        "0x%x != 0x%x\n",
 497                        le32_to_cpu(pgpt->partition_entry_array_crc32),
 498                        le32_to_cpu(agpt->partition_entry_array_crc32));
 499                 error_found++;
 500         }
 501         if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
 502                 printk(KERN_WARNING
 503                        "GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
 504                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 505                         (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
 506                         (unsigned long long)lastlba);
 507                 error_found++;
 508         }
 509
 510         if (le64_to_cpu(agpt->my_lba) != lastlba) {
 511                 printk(KERN_WARNING
 512                        "GPT:Alternate GPT header not at the end of the disk.\n");
 513                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 514                         (unsigned long long)le64_to_cpu(agpt->my_lba),
 515                         (unsigned long long)lastlba);
 516                 error_found++;
 517         }
 518
 519         if (error_found)
 520                 printk(KERN_WARNING
 521                        "GPT: Use GNU Parted to correct GPT errors.\n");
 522         return;
 523 }
 524
 525 /**
 526  * find_valid_gpt() - Search disk for valid GPT headers and PTEs
 527  * @state
 528  * @gpt is a GPT header ptr, filled on return.
 529  * @ptes is a PTEs ptr, filled on return.
 530  * Description: Returns 1 if valid, 0 on error.
 531  * If valid, returns pointers to newly allocated GPT header and PTEs.
 532  * Validity depends on PMBR being valid (or being overridden by the
 533  * 'gpt' kernel command line option) and finding either the Primary
 534  * GPT header and PTEs valid, or the Alternate GPT header and PTEs
 535  * valid.  If the Primary GPT header is not valid, the Alternate GPT header
 536  * is not checked unless the 'gpt' kernel command line option is passed.
 537  * This protects against devices which misreport their size, and forces
 538  * the user to decide to use the Alternate GPT.
 539  */
 540 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
 541                           gpt_entry **ptes)
 542 {
 543         int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
 544         gpt_header *pgpt = NULL, *agpt = NULL;
 545         gpt_entry *pptes = NULL, *aptes = NULL;
 546         legacy_mbr *legacymbr;
 547         u64 lastlba;
 548
 549         if (!ptes)
 550                 return 0;
 551
 552         lastlba = last_lba(state->bdev);
 553         if (!force_gpt) {
 554                 /* This will be added to the EFI Spec. per Intel after v1.02. */
 555                 legacymbr = kzalloc(sizeof (*legacymbr), GFP_KERNEL);
 556                 if (legacymbr) {
 557                         read_lba(state, 0, (u8 *) legacymbr,
 558                                  sizeof (*legacymbr));
 559                         good_pmbr = is_pmbr_valid(legacymbr);
 560                         kfree(legacymbr);
 561                 }
 562                 if (!good_pmbr)
 563                         goto fail;
 564         }
 565
 566         good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
 567                                  &pgpt, &pptes);
 568         if (good_pgpt)
 569                 good_agpt = is_gpt_valid(state,
 570                                          le64_to_cpu(pgpt->alternate_lba),
 571                                          &agpt, &aptes);
 572         if (!good_agpt && force_gpt)
 573                 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
 574
 575         /* The obviously unsuccessful case */
 576         if (!good_pgpt && !good_agpt)
 577                 goto fail;
 578
 579         compare_gpts(pgpt, agpt, lastlba);
 580
 581         /* The good cases */
 582         if (good_pgpt) {
 583                 *gpt  = pgpt;
 584                 *ptes = pptes;
 585                 kfree(agpt);
 586                 kfree(aptes);
 587                 if (!good_agpt) {
 588                         printk(KERN_WARNING
 589                                "Alternate GPT is invalid, "
 590                                "using primary GPT.\n");
 591                 }
 592                 return 1;
 593         }
 594         else if (good_agpt) {
 595                 *gpt  = agpt;
 596                 *ptes = aptes;
 597                 kfree(pgpt);
 598                 kfree(pptes);
 599                 printk(KERN_WARNING
 600                        "Primary GPT is invalid, using alternate GPT.\n");
 601                 return 1;
 602         }
 603
 604  fail:
 605         kfree(pgpt);
 606         kfree(agpt);
 607         kfree(pptes);
 608         kfree(aptes);
 609         *gpt = NULL;
 610         *ptes = NULL;
 611         return 0;
 612 }
 613
 614 /**
 615  * efi_partition(struct parsed_partitions *state)
 616  * @state
 617  *
 618  * Description: called from check.c, if the disk contains GPT
 619  * partitions, sets up partition entries in the kernel.
 620  *
 621  * If the first block on the disk is a legacy MBR,
 622  * it will get handled by msdos_partition().
 623  * If it's a Protective MBR, we'll handle it here.
 624  *
 625  * We do not create a Linux partition for GPT, but
 626  * only for the actual data partitions.
 627  * Returns:
 628  * -1 if unable to read the partition table
 629  *  0 if this isn't our partition table
 630  *  1 if successful
 631  *
 632  */
 633 int efi_partition(struct parsed_partitions *state)
 634 {
 635         gpt_header *gpt = NULL;
 636         gpt_entry *ptes = NULL;
 637         u32 i;
 638         unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
 639
 640         if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
 641                 kfree(gpt);
 642                 kfree(ptes);
 643                 return 0;
 644         }
 645
 646         pr_debug("GUID Partition Table is valid!  Yea!\n");
 647
 648         for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
 649                 struct partition_meta_info *info;
 650                 unsigned label_count = 0;
 651                 unsigned label_max;
 652                 u64 start = le64_to_cpu(ptes[i].starting_lba);
 653                 u64 size = le64_to_cpu(ptes[i].ending_lba) -
 654                            le64_to_cpu(ptes[i].starting_lba) + 1ULL;
 655
 656                 if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
 657                         continue;
 658
 659                 put_partition(state, i+1, start * ssz, size * ssz);
 660
 661                 /* If this is a RAID volume, tell md */
 662                 if (!efi_guidcmp(ptes[i].partition_type_guid,
 663                                  PARTITION_LINUX_RAID_GUID))
 664                         state->parts[i + 1].flags = ADDPART_FLAG_RAID;
 665
 666                 info = &state->parts[i + 1].info;
 667                 efi_guid_unparse(&ptes[i].unique_partition_guid, info->uuid);
 668
 669                 /* Naively convert UTF16-LE to 7 bits. */
 670                 label_max = min(sizeof(info->volname) - 1,
 671                                 sizeof(ptes[i].partition_name));
 672                 info->volname[label_max] = 0;
 673                 while (label_count < label_max) {
 674                         u8 c = ptes[i].partition_name[label_count] & 0xff;
 675                         if (c && !isprint(c))
 676                                 c = '!';
 677                         info->volname[label_count] = c;
 678                         label_count++;
 679                 }
 680                 state->parts[i + 1].has_info = true;
 681         }
 682         kfree(ptes);
 683         kfree(gpt);
 684         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 685         return 1;
 686 }