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
 153 pmbr_part_valid(struct partition *part)
 154 {
 155         if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
 156             le32_to_cpu(part->start_sect) == 1UL)
 157                 return 1;
 158         return 0;
 159 }
 160
 161 /**
 162  * is_pmbr_valid(): test Protective MBR for validity
 163  * @mbr: pointer to a legacy mbr structure
 164  *
 165  * Description: Returns 1 if PMBR is valid, 0 otherwise.
 166  * Validity depends on two things:
 167  *  1) MSDOS signature is in the last two bytes of the MBR
 168  *  2) One partition of type 0xEE is found
 169  */
 170 static int
 171 is_pmbr_valid(legacy_mbr *mbr)
 172 {
 173         int i;
 174         if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
 175                 return 0;
 176         for (i = 0; i < 4; i++)
 177                 if (pmbr_part_valid(&mbr->partition_record[i]))
 178                         return 1;
 179         return 0;
 180 }
 181
 182 /**
 183  * read_lba(): Read bytes from disk, starting at given LBA
 184  * @state
 185  * @lba
 186  * @buffer
 187  * @size_t
 188  *
 189  * Description: Reads @count bytes from @state->bdev into @buffer.
 190  * Returns number of bytes read on success, 0 on error.
 191  */
 192 static size_t read_lba(struct parsed_partitions *state,
 193                        u64 lba, u8 *buffer, size_t count)
 194 {
 195         size_t totalreadcount = 0;
 196         struct block_device *bdev = state->bdev;
 197         sector_t n = lba * (bdev_logical_block_size(bdev) / 512);
 198
 199         if (!buffer || lba > last_lba(bdev))
 200                 return 0;
 201
 202         while (count) {
 203                 int copied = 512;
 204                 Sector sect;
 205                 unsigned char *data = read_part_sector(state, n++, &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  * @state
 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 *alloc_read_gpt_entries(struct parsed_partitions *state,
 229                                          gpt_header *gpt)
 230 {
 231         size_t count;
 232         gpt_entry *pte;
 233
 234         if (!gpt)
 235                 return NULL;
 236
 237         count = le32_to_cpu(gpt->num_partition_entries) *
 238                 le32_to_cpu(gpt->sizeof_partition_entry);
 239         if (!count)
 240                 return NULL;
 241         pte = kmalloc(count, GFP_KERNEL);
 242         if (!pte)
 243                 return NULL;
 244
 245         if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
 246                      (u8 *) pte,
 247                      count) < count) {
 248                 kfree(pte);
 249                 pte=NULL;
 250                 return NULL;
 251         }
 252         return pte;
 253 }
 254
 255 /**
 256  * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
 257  * @state
 258  * @lba is the Logical Block Address of the partition table
 259  *
 260  * Description: returns GPT header on success, NULL on error.   Allocates
 261  * and fills a GPT header starting at @ from @state->bdev.
 262  * Note: remember to free gpt when finished with it.
 263  */
 264 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
 265                                          u64 lba)
 266 {
 267         gpt_header *gpt;
 268         unsigned ssz = bdev_logical_block_size(state->bdev);
 269
 270         gpt = kmalloc(ssz, GFP_KERNEL);
 271         if (!gpt)
 272                 return NULL;
 273
 274         if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
 275                 kfree(gpt);
 276                 gpt=NULL;
 277                 return NULL;
 278         }
 279
 280         return gpt;
 281 }
 282
 283 /**
 284  * is_gpt_valid() - tests one GPT header and PTEs for validity
 285  * @state
 286  * @lba is the logical block address of the GPT header to test
 287  * @gpt is a GPT header ptr, filled on return.
 288  * @ptes is a PTEs ptr, filled on return.
 289  *
 290  * Description: returns 1 if valid,  0 on error.
 291  * If valid, returns pointers to newly allocated GPT header and PTEs.
 292  */
 293 static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
 294                         gpt_header **gpt, gpt_entry **ptes)
 295 {
 296         u32 crc, origcrc;
 297         u64 lastlba;
 298
 299         if (!ptes)
 300                 return 0;
 301         if (!(*gpt = alloc_read_gpt_header(state, lba)))
 302                 return 0;
 303
 304         /* Check the GUID Partition Table signature */
 305         if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
 306                 pr_debug("GUID Partition Table Header signature is wrong:"
 307                          "%lld != %lld\n",
 308                          (unsigned long long)le64_to_cpu((*gpt)->signature),
 309                          (unsigned long long)GPT_HEADER_SIGNATURE);
 310                 goto fail;
 311         }
 312
 313         /* Check the GUID Partition Table header size is too big */
 314         if (le32_to_cpu((*gpt)->header_size) >
 315                         bdev_logical_block_size(state->bdev)) {
 316                 pr_debug("GUID Partition Table Header size is too large: %u > %u\n",
 317                         le32_to_cpu((*gpt)->header_size),
 318                         bdev_logical_block_size(state->bdev));
 319                 goto fail;
 320         }
 321
 322         /* Check the GUID Partition Table header size is too small */
 323         if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) {
 324                 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n",
 325                         le32_to_cpu((*gpt)->header_size),
 326                         sizeof(gpt_header));
 327                 goto fail;
 328         }
 329
 330         /* Check the GUID Partition Table CRC */
 331         origcrc = le32_to_cpu((*gpt)->header_crc32);
 332         (*gpt)->header_crc32 = 0;
 333         crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
 334
 335         if (crc != origcrc) {
 336                 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
 337                          crc, origcrc);
 338                 goto fail;
 339         }
 340         (*gpt)->header_crc32 = cpu_to_le32(origcrc);
 341
 342         /* Check that the my_lba entry points to the LBA that contains
 343          * the GUID Partition Table */
 344         if (le64_to_cpu((*gpt)->my_lba) != lba) {
 345                 pr_debug("GPT my_lba incorrect: %lld != %lld\n",
 346                          (unsigned long long)le64_to_cpu((*gpt)->my_lba),
 347                          (unsigned long long)lba);
 348                 goto fail;
 349         }
 350
 351         /* Check the first_usable_lba and last_usable_lba are
 352          * within the disk.
 353          */
 354         lastlba = last_lba(state->bdev);
 355         if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
 356                 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
 357                          (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
 358                          (unsigned long long)lastlba);
 359                 goto fail;
 360         }
 361         if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
 362                 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
 363                          (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
 364                          (unsigned long long)lastlba);
 365                 goto fail;
 366         }
 367
 368         /* Check that sizeof_partition_entry has the correct value */
 369         if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
 370                 pr_debug("GUID Partitition Entry Size check failed.\n");
 371                 goto fail;
 372         }
 373
 374         if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
 375                 goto fail;
 376
 377         /* Check the GUID Partition Entry Array CRC */
 378         crc = efi_crc32((const unsigned char *) (*ptes),
 379                         le32_to_cpu((*gpt)->num_partition_entries) *
 380                         le32_to_cpu((*gpt)->sizeof_partition_entry));
 381
 382         if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
 383                 pr_debug("GUID Partitition Entry Array CRC check failed.\n");
 384                 goto fail_ptes;
 385         }
 386
 387         /* We're done, all's well */
 388         return 1;
 389
 390  fail_ptes:
 391         kfree(*ptes);
 392         *ptes = NULL;
 393  fail:
 394         kfree(*gpt);
 395         *gpt = NULL;
 396         return 0;
 397 }
 398
 399 /**
 400  * is_pte_valid() - tests one PTE for validity
 401  * @pte is the pte to check
 402  * @lastlba is last lba of the disk
 403  *
 404  * Description: returns 1 if valid,  0 on error.
 405  */
 406 static inline int
 407 is_pte_valid(const gpt_entry *pte, const u64 lastlba)
 408 {
 409         if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
 410             le64_to_cpu(pte->starting_lba) > lastlba         ||
 411             le64_to_cpu(pte->ending_lba)   > lastlba)
 412                 return 0;
 413         return 1;
 414 }
 415
 416 /**
 417  * compare_gpts() - Search disk for valid GPT headers and PTEs
 418  * @pgpt is the primary GPT header
 419  * @agpt is the alternate GPT header
 420  * @lastlba is the last LBA number
 421  * Description: Returns nothing.  Sanity checks pgpt and agpt fields
 422  * and prints warnings on discrepancies.
 423  *
 424  */
 425 static void
 426 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
 427 {
 428         int error_found = 0;
 429         if (!pgpt || !agpt)
 430                 return;
 431         if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
 432                 printk(KERN_WARNING
 433                        "GPT:Primary header LBA != Alt. header alternate_lba\n");
 434                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 435                        (unsigned long long)le64_to_cpu(pgpt->my_lba),
 436                        (unsigned long long)le64_to_cpu(agpt->alternate_lba));
 437                 error_found++;
 438         }
 439         if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
 440                 printk(KERN_WARNING
 441                        "GPT:Primary header alternate_lba != Alt. header my_lba\n");
 442                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 443                        (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
 444                        (unsigned long long)le64_to_cpu(agpt->my_lba));
 445                 error_found++;
 446         }
 447         if (le64_to_cpu(pgpt->first_usable_lba) !=
 448             le64_to_cpu(agpt->first_usable_lba)) {
 449                 printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n");
 450                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 451                        (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
 452                        (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
 453                 error_found++;
 454         }
 455         if (le64_to_cpu(pgpt->last_usable_lba) !=
 456             le64_to_cpu(agpt->last_usable_lba)) {
 457                 printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n");
 458                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 459                        (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
 460                        (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
 461                 error_found++;
 462         }
 463         if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
 464                 printk(KERN_WARNING "GPT:disk_guids don't match.\n");
 465                 error_found++;
 466         }
 467         if (le32_to_cpu(pgpt->num_partition_entries) !=
 468             le32_to_cpu(agpt->num_partition_entries)) {
 469                 printk(KERN_WARNING "GPT:num_partition_entries don't match: "
 470                        "0x%x != 0x%x\n",
 471                        le32_to_cpu(pgpt->num_partition_entries),
 472                        le32_to_cpu(agpt->num_partition_entries));
 473                 error_found++;
 474         }
 475         if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
 476             le32_to_cpu(agpt->sizeof_partition_entry)) {
 477                 printk(KERN_WARNING
 478                        "GPT:sizeof_partition_entry values don't match: "
 479                        "0x%x != 0x%x\n",
 480                        le32_to_cpu(pgpt->sizeof_partition_entry),
 481                        le32_to_cpu(agpt->sizeof_partition_entry));
 482                 error_found++;
 483         }
 484         if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
 485             le32_to_cpu(agpt->partition_entry_array_crc32)) {
 486                 printk(KERN_WARNING
 487                        "GPT:partition_entry_array_crc32 values don't match: "
 488                        "0x%x != 0x%x\n",
 489                        le32_to_cpu(pgpt->partition_entry_array_crc32),
 490                        le32_to_cpu(agpt->partition_entry_array_crc32));
 491                 error_found++;
 492         }
 493         if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
 494                 printk(KERN_WARNING
 495                        "GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
 496                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 497                         (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
 498                         (unsigned long long)lastlba);
 499                 error_found++;
 500         }
 501
 502         if (le64_to_cpu(agpt->my_lba) != lastlba) {
 503                 printk(KERN_WARNING
 504                        "GPT:Alternate GPT header not at the end of the disk.\n");
 505                 printk(KERN_WARNING "GPT:%lld != %lld\n",
 506                         (unsigned long long)le64_to_cpu(agpt->my_lba),
 507                         (unsigned long long)lastlba);
 508                 error_found++;
 509         }
 510
 511         if (error_found)
 512                 printk(KERN_WARNING
 513                        "GPT: Use GNU Parted to correct GPT errors.\n");
 514         return;
 515 }
 516
 517 /**
 518  * find_valid_gpt() - Search disk for valid GPT headers and PTEs
 519  * @state
 520  * @gpt is a GPT header ptr, filled on return.
 521  * @ptes is a PTEs ptr, filled on return.
 522  * Description: Returns 1 if valid, 0 on error.
 523  * If valid, returns pointers to newly allocated GPT header and PTEs.
 524  * Validity depends on PMBR being valid (or being overridden by the
 525  * 'gpt' kernel command line option) and finding either the Primary
 526  * GPT header and PTEs valid, or the Alternate GPT header and PTEs
 527  * valid.  If the Primary GPT header is not valid, the Alternate GPT header
 528  * is not checked unless the 'gpt' kernel command line option is passed.
 529  * This protects against devices which misreport their size, and forces
 530  * the user to decide to use the Alternate GPT.
 531  */
 532 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
 533                           gpt_entry **ptes)
 534 {
 535         int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
 536         gpt_header *pgpt = NULL, *agpt = NULL;
 537         gpt_entry *pptes = NULL, *aptes = NULL;
 538         legacy_mbr *legacymbr;
 539         u64 lastlba;
 540
 541         if (!ptes)
 542                 return 0;
 543
 544         lastlba = last_lba(state->bdev);
 545         if (!force_gpt) {
 546                 /* This will be added to the EFI Spec. per Intel after v1.02. */
 547                 legacymbr = kzalloc(sizeof (*legacymbr), GFP_KERNEL);
 548                 if (legacymbr) {
 549                         read_lba(state, 0, (u8 *) legacymbr,
 550                                  sizeof (*legacymbr));
 551                         good_pmbr = is_pmbr_valid(legacymbr);
 552                         kfree(legacymbr);
 553                 }
 554                 if (!good_pmbr)
 555                         goto fail;
 556         }
 557
 558         good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
 559                                  &pgpt, &pptes);
 560         if (good_pgpt)
 561                 good_agpt = is_gpt_valid(state,
 562                                          le64_to_cpu(pgpt->alternate_lba),
 563                                          &agpt, &aptes);
 564         if (!good_agpt && force_gpt)
 565                 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
 566
 567         /* The obviously unsuccessful case */
 568         if (!good_pgpt && !good_agpt)
 569                 goto fail;
 570
 571         compare_gpts(pgpt, agpt, lastlba);
 572
 573         /* The good cases */
 574         if (good_pgpt) {
 575                 *gpt  = pgpt;
 576                 *ptes = pptes;
 577                 kfree(agpt);
 578                 kfree(aptes);
 579                 if (!good_agpt) {
 580                         printk(KERN_WARNING
 581                                "Alternate GPT is invalid, "
 582                                "using primary GPT.\n");
 583                 }
 584                 return 1;
 585         }
 586         else if (good_agpt) {
 587                 *gpt  = agpt;
 588                 *ptes = aptes;
 589                 kfree(pgpt);
 590                 kfree(pptes);
 591                 printk(KERN_WARNING
 592                        "Primary GPT is invalid, using alternate GPT.\n");
 593                 return 1;
 594         }
 595
 596  fail:
 597         kfree(pgpt);
 598         kfree(agpt);
 599         kfree(pptes);
 600         kfree(aptes);
 601         *gpt = NULL;
 602         *ptes = NULL;
 603         return 0;
 604 }
 605
 606 /**
 607  * efi_partition(struct parsed_partitions *state)
 608  * @state
 609  *
 610  * Description: called from check.c, if the disk contains GPT
 611  * partitions, sets up partition entries in the kernel.
 612  *
 613  * If the first block on the disk is a legacy MBR,
 614  * it will get handled by msdos_partition().
 615  * If it's a Protective MBR, we'll handle it here.
 616  *
 617  * We do not create a Linux partition for GPT, but
 618  * only for the actual data partitions.
 619  * Returns:
 620  * -1 if unable to read the partition table
 621  *  0 if this isn't our partition table
 622  *  1 if successful
 623  *
 624  */
 625 int efi_partition(struct parsed_partitions *state)
 626 {
 627         gpt_header *gpt = NULL;
 628         gpt_entry *ptes = NULL;
 629         u32 i;
 630         unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
 631
 632         if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
 633                 kfree(gpt);
 634                 kfree(ptes);
 635                 return 0;
 636         }
 637
 638         pr_debug("GUID Partition Table is valid!  Yea!\n");
 639
 640         for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
 641                 struct partition_meta_info *info;
 642                 unsigned label_count = 0;
 643                 unsigned label_max;
 644                 u64 start = le64_to_cpu(ptes[i].starting_lba);
 645                 u64 size = le64_to_cpu(ptes[i].ending_lba) -
 646                            le64_to_cpu(ptes[i].starting_lba) + 1ULL;
 647
 648                 if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
 649                         continue;
 650
 651                 put_partition(state, i+1, start * ssz, size * ssz);
 652
 653                 /* If this is a RAID volume, tell md */
 654                 if (!efi_guidcmp(ptes[i].partition_type_guid,
 655                                  PARTITION_LINUX_RAID_GUID))
 656                         state->parts[i + 1].flags = ADDPART_FLAG_RAID;
 657
 658                 info = &state->parts[i + 1].info;
 659                 efi_guid_unparse(&ptes[i].unique_partition_guid, info->uuid);
 660
 661                 /* Naively convert UTF16-LE to 7 bits. */
 662                 label_max = min(sizeof(info->volname) - 1,
 663                                 sizeof(ptes[i].partition_name));
 664                 info->volname[label_max] = 0;
 665                 while (label_count < label_max) {
 666                         u8 c = ptes[i].partition_name[label_count] & 0xff;
 667                         if (c && !isprint(c))
 668                                 c = '!';
 669                         info->volname[label_count] = c;
 670                         label_count++;
 671                 }
 672                 state->parts[i + 1].has_info = true;
 673         }
 674         kfree(ptes);
 675         kfree(gpt);
 676         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 677         return 1;
 678 }