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 August 5th, 2013 Davidlohr Bueso <davidlohr@hp.com> 29 * - detect hybrid MBRs, tighter pMBR checking & cleanups. 30 * 31 * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com> 32 * - test for valid PMBR and valid PGPT before ever reading 33 * AGPT, allow override with 'gpt' kernel command line option. 34 * - check for first/last_usable_lba outside of size of disk 35 * 36 * Tue Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com> 37 * - Ported to 2.5.7-pre1 and 2.5.7-dj2 38 * - Applied patch to avoid fault in alternate header handling 39 * - cleaned up find_valid_gpt 40 * - On-disk structure and copy in memory is *always* LE now - 41 * swab fields as needed 42 * - remove print_gpt_header() 43 * - only use first max_p partition entries, to keep the kernel minor number 44 * and partition numbers tied. 45 * 46 * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com> 47 * - Removed __PRIPTR_PREFIX - not being used 48 * 49 * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com> 50 * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied 51 * 52 * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com> 53 * - Added compare_gpts(). 54 * - moved le_efi_guid_to_cpus() back into this file. GPT is the only 55 * thing that keeps EFI GUIDs on disk. 56 * - Changed gpt structure names and members to be simpler and more Linux-like. 57 * 58 * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com> 59 * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck 60 * 61 * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com> 62 * - Changed function comments to DocBook style per Andreas Dilger suggestion. 63 * 64 * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com> 65 * - Change read_lba() to use the page cache per Al Viro's work. 66 * - print u64s properly on all architectures 67 * - fixed debug_printk(), now Dprintk() 68 * 69 * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com> 70 * - Style cleanups 71 * - made most functions static 72 * - Endianness addition 73 * - remove test for second alternate header, as it's not per spec, 74 * and is unnecessary. There's now a method to read/write the last 75 * sector of an odd-sized disk from user space. No tools have ever 76 * been released which used this code, so it's effectively dead. 77 * - Per Asit Mallick of Intel, added a test for a valid PMBR. 78 * - Added kernel command line option 'gpt' to override valid PMBR test. 79 * 80 * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com> 81 * - added devfs volume UUID support (/dev/volumes/uuids) for 82 * mounting file systems by the partition GUID. 83 * 84 * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com> 85 * - Moved crc32() to linux/lib, added efi_crc32(). 86 * 87 * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com> 88 * - Replaced Intel's CRC32 function with an equivalent 89 * non-license-restricted version. 90 * 91 * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com> 92 * - Fixed the last_lba() call to return the proper last block 93 * 94 * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com> 95 * - Thanks to Andries Brouwer for his debugging assistance. 96 * - Code works, detects all the partitions. 97 * 98 ************************************************************/ 99 #include <linux/crc32.h> 100 #include <linux/ctype.h> 101 #include <linux/math64.h> 102 #include <linux/slab.h> 103 #include "check.h" 104 #include "efi.h" 105 106 /* This allows a kernel command line option 'gpt' to override 107 * the test for invalid PMBR. Not __initdata because reloading 108 * the partition tables happens after init too. 109 */ 110 static int force_gpt; 111 static int __init 112 force_gpt_fn(char *str) 113 { 114 force_gpt = 1; 115 return 1; 116 } 117 __setup("gpt", force_gpt_fn); 118 119 120 /** 121 * efi_crc32() - EFI version of crc32 function 122 * @buf: buffer to calculate crc32 of 123 * @len - length of buf 124 * 125 * Description: Returns EFI-style CRC32 value for @buf 126 * 127 * This function uses the little endian Ethernet polynomial 128 * but seeds the function with ~0, and xor's with ~0 at the end. 129 * Note, the EFI Specification, v1.02, has a reference to 130 * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). 131 */ 132 static inline u32 133 efi_crc32(const void *buf, unsigned long len) 134 { 135 return (crc32(~0L, buf, len) ^ ~0L); 136 } 137 138 /** 139 * last_lba(): return number of last logical block of device 140 * @bdev: block device 141 * 142 * Description: Returns last LBA value on success, 0 on error. 143 * This is stored (by sd and ide-geometry) in 144 * the part[0] entry for this disk, and is the number of 145 * physical sectors available on the disk. 146 */ 147 static u64 last_lba(struct block_device *bdev) 148 { 149 if (!bdev || !bdev->bd_inode) 150 return 0; 151 return div_u64(bdev->bd_inode->i_size, 152 bdev_logical_block_size(bdev)) - 1ULL; 153 } 154 155 static inline int pmbr_part_valid(gpt_mbr_record *part) 156 { 157 if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT) 158 goto invalid; 159 160 /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */ 161 if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA) 162 goto invalid; 163 164 return GPT_MBR_PROTECTIVE; 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 * @total_sectors: amount of sectors in the device 173 * 174 * Description: Checks for a valid protective or hybrid 175 * master boot record (MBR). The validity of a pMBR depends 176 * on all of the following properties: 177 * 1) MSDOS signature is in the last two bytes of the MBR 178 * 2) One partition of type 0xEE is found 179 * 180 * In addition, a hybrid MBR will have up to three additional 181 * primary partitions, which point to the same space that's 182 * marked out by up to three GPT partitions. 183 * 184 * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or 185 * GPT_MBR_HYBRID depending on the device layout. 186 */ 187 static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors) 188 { 189 uint32_t sz = 0; 190 int i, part = 0, ret = 0; /* invalid by default */ 191 192 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE) 193 goto done; 194 195 for (i = 0; i < 4; i++) { 196 ret = pmbr_part_valid(&mbr->partition_record[i]); 197 if (ret == GPT_MBR_PROTECTIVE) { 198 part = i; 199 /* 200 * Ok, we at least know that there's a protective MBR, 201 * now check if there are other partition types for 202 * hybrid MBR. 203 */ 204 goto check_hybrid; 205 } 206 } 207 208 if (ret != GPT_MBR_PROTECTIVE) 209 goto done; 210 check_hybrid: 211 for (i = 0; i < 4; i++) 212 if ((mbr->partition_record[i].os_type != 213 EFI_PMBR_OSTYPE_EFI_GPT) && 214 (mbr->partition_record[i].os_type != 0x00)) 215 ret = GPT_MBR_HYBRID; 216 217 /* 218 * Protective MBRs take up the lesser of the whole disk 219 * or 2 TiB (32bit LBA), ignoring the rest of the disk. 220 * Some partitioning programs, nonetheless, choose to set 221 * the size to the maximum 32-bit limitation, disregarding 222 * the disk size. 223 * 224 * Hybrid MBRs do not necessarily comply with this. 225 * 226 * Consider a bad value here to be a warning to support dd'ing 227 * an image from a smaller disk to a larger disk. 228 */ 229 if (ret == GPT_MBR_PROTECTIVE) { 230 sz = le32_to_cpu(mbr->partition_record[part].size_in_lba); 231 if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF) 232 pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n", 233 sz, min_t(uint32_t, 234 total_sectors - 1, 0xFFFFFFFF)); 235 } 236 done: 237 return ret; 238 } 239 240 /** 241 * read_lba(): Read bytes from disk, starting at given LBA 242 * @state 243 * @lba 244 * @buffer 245 * @size_t 246 * 247 * Description: Reads @count bytes from @state->bdev into @buffer. 248 * Returns number of bytes read on success, 0 on error. 249 */ 250 static size_t read_lba(struct parsed_partitions *state, 251 u64 lba, u8 *buffer, size_t count) 252 { 253 size_t totalreadcount = 0; 254 struct block_device *bdev = state->bdev; 255 sector_t n = lba * (bdev_logical_block_size(bdev) / 512); 256 257 if (!buffer || lba > last_lba(bdev)) 258 return 0; 259 260 while (count) { 261 int copied = 512; 262 Sector sect; 263 unsigned char *data = read_part_sector(state, n++, §); 264 if (!data) 265 break; 266 if (copied > count) 267 copied = count; 268 memcpy(buffer, data, copied); 269 put_dev_sector(sect); 270 buffer += copied; 271 totalreadcount +=copied; 272 count -= copied; 273 } 274 return totalreadcount; 275 } 276 277 /** 278 * alloc_read_gpt_entries(): reads partition entries from disk 279 * @state 280 * @gpt - GPT header 281 * 282 * Description: Returns ptes on success, NULL on error. 283 * Allocates space for PTEs based on information found in @gpt. 284 * Notes: remember to free pte when you're done! 285 */ 286 static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state, 287 gpt_header *gpt) 288 { 289 size_t count; 290 gpt_entry *pte; 291 292 if (!gpt) 293 return NULL; 294 295 count = le32_to_cpu(gpt->num_partition_entries) * 296 le32_to_cpu(gpt->sizeof_partition_entry); 297 if (!count) 298 return NULL; 299 pte = kmalloc(count, GFP_KERNEL); 300 if (!pte) 301 return NULL; 302 303 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba), 304 (u8 *) pte, count) < count) { 305 kfree(pte); 306 pte=NULL; 307 return NULL; 308 } 309 return pte; 310 } 311 312 /** 313 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk 314 * @state 315 * @lba is the Logical Block Address of the partition table 316 * 317 * Description: returns GPT header on success, NULL on error. Allocates 318 * and fills a GPT header starting at @ from @state->bdev. 319 * Note: remember to free gpt when finished with it. 320 */ 321 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state, 322 u64 lba) 323 { 324 gpt_header *gpt; 325 unsigned ssz = bdev_logical_block_size(state->bdev); 326 327 gpt = kmalloc(ssz, GFP_KERNEL); 328 if (!gpt) 329 return NULL; 330 331 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) { 332 kfree(gpt); 333 gpt=NULL; 334 return NULL; 335 } 336 337 return gpt; 338 } 339 340 /** 341 * is_gpt_valid() - tests one GPT header and PTEs for validity 342 * @state 343 * @lba is the logical block address of the GPT header to test 344 * @gpt is a GPT header ptr, filled on return. 345 * @ptes is a PTEs ptr, filled on return. 346 * 347 * Description: returns 1 if valid, 0 on error. 348 * If valid, returns pointers to newly allocated GPT header and PTEs. 349 */ 350 static int is_gpt_valid(struct parsed_partitions *state, u64 lba, 351 gpt_header **gpt, gpt_entry **ptes) 352 { 353 u32 crc, origcrc; 354 u64 lastlba; 355 356 if (!ptes) 357 return 0; 358 if (!(*gpt = alloc_read_gpt_header(state, lba))) 359 return 0; 360 361 /* Check the GUID Partition Table signature */ 362 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { 363 pr_debug("GUID Partition Table Header signature is wrong:" 364 "%lld != %lld\n", 365 (unsigned long long)le64_to_cpu((*gpt)->signature), 366 (unsigned long long)GPT_HEADER_SIGNATURE); 367 goto fail; 368 } 369 370 /* Check the GUID Partition Table header size is too big */ 371 if (le32_to_cpu((*gpt)->header_size) > 372 bdev_logical_block_size(state->bdev)) { 373 pr_debug("GUID Partition Table Header size is too large: %u > %u\n", 374 le32_to_cpu((*gpt)->header_size), 375 bdev_logical_block_size(state->bdev)); 376 goto fail; 377 } 378 379 /* Check the GUID Partition Table header size is too small */ 380 if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) { 381 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n", 382 le32_to_cpu((*gpt)->header_size), 383 sizeof(gpt_header)); 384 goto fail; 385 } 386 387 /* Check the GUID Partition Table CRC */ 388 origcrc = le32_to_cpu((*gpt)->header_crc32); 389 (*gpt)->header_crc32 = 0; 390 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); 391 392 if (crc != origcrc) { 393 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n", 394 crc, origcrc); 395 goto fail; 396 } 397 (*gpt)->header_crc32 = cpu_to_le32(origcrc); 398 399 /* Check that the my_lba entry points to the LBA that contains 400 * the GUID Partition Table */ 401 if (le64_to_cpu((*gpt)->my_lba) != lba) { 402 pr_debug("GPT my_lba incorrect: %lld != %lld\n", 403 (unsigned long long)le64_to_cpu((*gpt)->my_lba), 404 (unsigned long long)lba); 405 goto fail; 406 } 407 408 /* Check the first_usable_lba and last_usable_lba are 409 * within the disk. 410 */ 411 lastlba = last_lba(state->bdev); 412 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) { 413 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n", 414 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba), 415 (unsigned long long)lastlba); 416 goto fail; 417 } 418 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) { 419 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 420 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 421 (unsigned long long)lastlba); 422 goto fail; 423 } 424 if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) { 425 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 426 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 427 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba)); 428 goto fail; 429 } 430 /* Check that sizeof_partition_entry has the correct value */ 431 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) { 432 pr_debug("GUID Partitition Entry Size check failed.\n"); 433 goto fail; 434 } 435 436 if (!(*ptes = alloc_read_gpt_entries(state, *gpt))) 437 goto fail; 438 439 /* Check the GUID Partition Entry Array CRC */ 440 crc = efi_crc32((const unsigned char *) (*ptes), 441 le32_to_cpu((*gpt)->num_partition_entries) * 442 le32_to_cpu((*gpt)->sizeof_partition_entry)); 443 444 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { 445 pr_debug("GUID Partitition Entry Array CRC check failed.\n"); 446 goto fail_ptes; 447 } 448 449 /* We're done, all's well */ 450 return 1; 451 452 fail_ptes: 453 kfree(*ptes); 454 *ptes = NULL; 455 fail: 456 kfree(*gpt); 457 *gpt = NULL; 458 return 0; 459 } 460 461 /** 462 * is_pte_valid() - tests one PTE for validity 463 * @pte is the pte to check 464 * @lastlba is last lba of the disk 465 * 466 * Description: returns 1 if valid, 0 on error. 467 */ 468 static inline int 469 is_pte_valid(const gpt_entry *pte, const u64 lastlba) 470 { 471 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) || 472 le64_to_cpu(pte->starting_lba) > lastlba || 473 le64_to_cpu(pte->ending_lba) > lastlba) 474 return 0; 475 return 1; 476 } 477 478 /** 479 * compare_gpts() - Search disk for valid GPT headers and PTEs 480 * @pgpt is the primary GPT header 481 * @agpt is the alternate GPT header 482 * @lastlba is the last LBA number 483 * Description: Returns nothing. Sanity checks pgpt and agpt fields 484 * and prints warnings on discrepancies. 485 * 486 */ 487 static void 488 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) 489 { 490 int error_found = 0; 491 if (!pgpt || !agpt) 492 return; 493 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { 494 pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n"); 495 pr_warn("GPT:%lld != %lld\n", 496 (unsigned long long)le64_to_cpu(pgpt->my_lba), 497 (unsigned long long)le64_to_cpu(agpt->alternate_lba)); 498 error_found++; 499 } 500 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { 501 pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n"); 502 pr_warn("GPT:%lld != %lld\n", 503 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 504 (unsigned long long)le64_to_cpu(agpt->my_lba)); 505 error_found++; 506 } 507 if (le64_to_cpu(pgpt->first_usable_lba) != 508 le64_to_cpu(agpt->first_usable_lba)) { 509 pr_warn("GPT:first_usable_lbas don't match.\n"); 510 pr_warn("GPT:%lld != %lld\n", 511 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba), 512 (unsigned long long)le64_to_cpu(agpt->first_usable_lba)); 513 error_found++; 514 } 515 if (le64_to_cpu(pgpt->last_usable_lba) != 516 le64_to_cpu(agpt->last_usable_lba)) { 517 pr_warn("GPT:last_usable_lbas don't match.\n"); 518 pr_warn("GPT:%lld != %lld\n", 519 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba), 520 (unsigned long long)le64_to_cpu(agpt->last_usable_lba)); 521 error_found++; 522 } 523 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { 524 pr_warn("GPT:disk_guids don't match.\n"); 525 error_found++; 526 } 527 if (le32_to_cpu(pgpt->num_partition_entries) != 528 le32_to_cpu(agpt->num_partition_entries)) { 529 pr_warn("GPT:num_partition_entries don't match: " 530 "0x%x != 0x%x\n", 531 le32_to_cpu(pgpt->num_partition_entries), 532 le32_to_cpu(agpt->num_partition_entries)); 533 error_found++; 534 } 535 if (le32_to_cpu(pgpt->sizeof_partition_entry) != 536 le32_to_cpu(agpt->sizeof_partition_entry)) { 537 pr_warn("GPT:sizeof_partition_entry values don't match: " 538 "0x%x != 0x%x\n", 539 le32_to_cpu(pgpt->sizeof_partition_entry), 540 le32_to_cpu(agpt->sizeof_partition_entry)); 541 error_found++; 542 } 543 if (le32_to_cpu(pgpt->partition_entry_array_crc32) != 544 le32_to_cpu(agpt->partition_entry_array_crc32)) { 545 pr_warn("GPT:partition_entry_array_crc32 values don't match: " 546 "0x%x != 0x%x\n", 547 le32_to_cpu(pgpt->partition_entry_array_crc32), 548 le32_to_cpu(agpt->partition_entry_array_crc32)); 549 error_found++; 550 } 551 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { 552 pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); 553 pr_warn("GPT:%lld != %lld\n", 554 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 555 (unsigned long long)lastlba); 556 error_found++; 557 } 558 559 if (le64_to_cpu(agpt->my_lba) != lastlba) { 560 pr_warn("GPT:Alternate GPT header not at the end of the disk.\n"); 561 pr_warn("GPT:%lld != %lld\n", 562 (unsigned long long)le64_to_cpu(agpt->my_lba), 563 (unsigned long long)lastlba); 564 error_found++; 565 } 566 567 if (error_found) 568 pr_warn("GPT: Use GNU Parted to correct GPT errors.\n"); 569 return; 570 } 571 572 /** 573 * find_valid_gpt() - Search disk for valid GPT headers and PTEs 574 * @state 575 * @gpt is a GPT header ptr, filled on return. 576 * @ptes is a PTEs ptr, filled on return. 577 * Description: Returns 1 if valid, 0 on error. 578 * If valid, returns pointers to newly allocated GPT header and PTEs. 579 * Validity depends on PMBR being valid (or being overridden by the 580 * 'gpt' kernel command line option) and finding either the Primary 581 * GPT header and PTEs valid, or the Alternate GPT header and PTEs 582 * valid. If the Primary GPT header is not valid, the Alternate GPT header 583 * is not checked unless the 'gpt' kernel command line option is passed. 584 * This protects against devices which misreport their size, and forces 585 * the user to decide to use the Alternate GPT. 586 */ 587 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt, 588 gpt_entry **ptes) 589 { 590 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; 591 gpt_header *pgpt = NULL, *agpt = NULL; 592 gpt_entry *pptes = NULL, *aptes = NULL; 593 legacy_mbr *legacymbr; 594 sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9; 595 u64 lastlba; 596 597 if (!ptes) 598 return 0; 599 600 lastlba = last_lba(state->bdev); 601 if (!force_gpt) { 602 /* This will be added to the EFI Spec. per Intel after v1.02. */ 603 legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL); 604 if (!legacymbr) 605 goto fail; 606 607 read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr)); 608 good_pmbr = is_pmbr_valid(legacymbr, total_sectors); 609 kfree(legacymbr); 610 611 if (!good_pmbr) 612 goto fail; 613 614 pr_debug("Device has a %s MBR\n", 615 good_pmbr == GPT_MBR_PROTECTIVE ? 616 "protective" : "hybrid"); 617 } 618 619 good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA, 620 &pgpt, &pptes); 621 if (good_pgpt) 622 good_agpt = is_gpt_valid(state, 623 le64_to_cpu(pgpt->alternate_lba), 624 &agpt, &aptes); 625 if (!good_agpt && force_gpt) 626 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes); 627 628 /* The obviously unsuccessful case */ 629 if (!good_pgpt && !good_agpt) 630 goto fail; 631 632 compare_gpts(pgpt, agpt, lastlba); 633 634 /* The good cases */ 635 if (good_pgpt) { 636 *gpt = pgpt; 637 *ptes = pptes; 638 kfree(agpt); 639 kfree(aptes); 640 if (!good_agpt) 641 pr_warn("Alternate GPT is invalid, using primary GPT.\n"); 642 return 1; 643 } 644 else if (good_agpt) { 645 *gpt = agpt; 646 *ptes = aptes; 647 kfree(pgpt); 648 kfree(pptes); 649 pr_warn("Primary GPT is invalid, using alternate GPT.\n"); 650 return 1; 651 } 652 653 fail: 654 kfree(pgpt); 655 kfree(agpt); 656 kfree(pptes); 657 kfree(aptes); 658 *gpt = NULL; 659 *ptes = NULL; 660 return 0; 661 } 662 663 /** 664 * efi_partition(struct parsed_partitions *state) 665 * @state 666 * 667 * Description: called from check.c, if the disk contains GPT 668 * partitions, sets up partition entries in the kernel. 669 * 670 * If the first block on the disk is a legacy MBR, 671 * it will get handled by msdos_partition(). 672 * If it's a Protective MBR, we'll handle it here. 673 * 674 * We do not create a Linux partition for GPT, but 675 * only for the actual data partitions. 676 * Returns: 677 * -1 if unable to read the partition table 678 * 0 if this isn't our partition table 679 * 1 if successful 680 * 681 */ 682 int efi_partition(struct parsed_partitions *state) 683 { 684 gpt_header *gpt = NULL; 685 gpt_entry *ptes = NULL; 686 u32 i; 687 unsigned ssz = bdev_logical_block_size(state->bdev) / 512; 688 689 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) { 690 kfree(gpt); 691 kfree(ptes); 692 return 0; 693 } 694 695 pr_debug("GUID Partition Table is valid! Yea!\n"); 696 697 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { 698 struct partition_meta_info *info; 699 unsigned label_count = 0; 700 unsigned label_max; 701 u64 start = le64_to_cpu(ptes[i].starting_lba); 702 u64 size = le64_to_cpu(ptes[i].ending_lba) - 703 le64_to_cpu(ptes[i].starting_lba) + 1ULL; 704 705 if (!is_pte_valid(&ptes[i], last_lba(state->bdev))) 706 continue; 707 708 put_partition(state, i+1, start * ssz, size * ssz); 709 710 /* If this is a RAID volume, tell md */ 711 if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID)) 712 state->parts[i + 1].flags = ADDPART_FLAG_RAID; 713 714 info = &state->parts[i + 1].info; 715 efi_guid_unparse(&ptes[i].unique_partition_guid, info->uuid); 716 717 /* Naively convert UTF16-LE to 7 bits. */ 718 label_max = min(sizeof(info->volname) - 1, 719 sizeof(ptes[i].partition_name)); 720 info->volname[label_max] = 0; 721 while (label_count < label_max) { 722 u8 c = ptes[i].partition_name[label_count] & 0xff; 723 if (c && !isprint(c)) 724 c = '!'; 725 info->volname[label_count] = c; 726 label_count++; 727 } 728 state->parts[i + 1].has_info = true; 729 } 730 kfree(ptes); 731 kfree(gpt); 732 strlcat(state->pp_buf, "\n", PAGE_SIZE); 733 return 1; 734 } 735