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 if (ret == GPT_MBR_PROTECTIVE) { 227 sz = le32_to_cpu(mbr->partition_record[part].size_in_lba); 228 if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF) 229 ret = 0; 230 } 231 done: 232 return ret; 233 } 234 235 /** 236 * read_lba(): Read bytes from disk, starting at given LBA 237 * @state 238 * @lba 239 * @buffer 240 * @size_t 241 * 242 * Description: Reads @count bytes from @state->bdev into @buffer. 243 * Returns number of bytes read on success, 0 on error. 244 */ 245 static size_t read_lba(struct parsed_partitions *state, 246 u64 lba, u8 *buffer, size_t count) 247 { 248 size_t totalreadcount = 0; 249 struct block_device *bdev = state->bdev; 250 sector_t n = lba * (bdev_logical_block_size(bdev) / 512); 251 252 if (!buffer || lba > last_lba(bdev)) 253 return 0; 254 255 while (count) { 256 int copied = 512; 257 Sector sect; 258 unsigned char *data = read_part_sector(state, n++, §); 259 if (!data) 260 break; 261 if (copied > count) 262 copied = count; 263 memcpy(buffer, data, copied); 264 put_dev_sector(sect); 265 buffer += copied; 266 totalreadcount +=copied; 267 count -= copied; 268 } 269 return totalreadcount; 270 } 271 272 /** 273 * alloc_read_gpt_entries(): reads partition entries from disk 274 * @state 275 * @gpt - GPT header 276 * 277 * Description: Returns ptes on success, NULL on error. 278 * Allocates space for PTEs based on information found in @gpt. 279 * Notes: remember to free pte when you're done! 280 */ 281 static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state, 282 gpt_header *gpt) 283 { 284 size_t count; 285 gpt_entry *pte; 286 287 if (!gpt) 288 return NULL; 289 290 count = le32_to_cpu(gpt->num_partition_entries) * 291 le32_to_cpu(gpt->sizeof_partition_entry); 292 if (!count) 293 return NULL; 294 pte = kmalloc(count, GFP_KERNEL); 295 if (!pte) 296 return NULL; 297 298 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba), 299 (u8 *) pte, count) < count) { 300 kfree(pte); 301 pte=NULL; 302 return NULL; 303 } 304 return pte; 305 } 306 307 /** 308 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk 309 * @state 310 * @lba is the Logical Block Address of the partition table 311 * 312 * Description: returns GPT header on success, NULL on error. Allocates 313 * and fills a GPT header starting at @ from @state->bdev. 314 * Note: remember to free gpt when finished with it. 315 */ 316 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state, 317 u64 lba) 318 { 319 gpt_header *gpt; 320 unsigned ssz = bdev_logical_block_size(state->bdev); 321 322 gpt = kmalloc(ssz, GFP_KERNEL); 323 if (!gpt) 324 return NULL; 325 326 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) { 327 kfree(gpt); 328 gpt=NULL; 329 return NULL; 330 } 331 332 return gpt; 333 } 334 335 /** 336 * is_gpt_valid() - tests one GPT header and PTEs for validity 337 * @state 338 * @lba is the logical block address of the GPT header to test 339 * @gpt is a GPT header ptr, filled on return. 340 * @ptes is a PTEs ptr, filled on return. 341 * 342 * Description: returns 1 if valid, 0 on error. 343 * If valid, returns pointers to newly allocated GPT header and PTEs. 344 */ 345 static int is_gpt_valid(struct parsed_partitions *state, u64 lba, 346 gpt_header **gpt, gpt_entry **ptes) 347 { 348 u32 crc, origcrc; 349 u64 lastlba; 350 351 if (!ptes) 352 return 0; 353 if (!(*gpt = alloc_read_gpt_header(state, lba))) 354 return 0; 355 356 /* Check the GUID Partition Table signature */ 357 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { 358 pr_debug("GUID Partition Table Header signature is wrong:" 359 "%lld != %lld\n", 360 (unsigned long long)le64_to_cpu((*gpt)->signature), 361 (unsigned long long)GPT_HEADER_SIGNATURE); 362 goto fail; 363 } 364 365 /* Check the GUID Partition Table header size is too big */ 366 if (le32_to_cpu((*gpt)->header_size) > 367 bdev_logical_block_size(state->bdev)) { 368 pr_debug("GUID Partition Table Header size is too large: %u > %u\n", 369 le32_to_cpu((*gpt)->header_size), 370 bdev_logical_block_size(state->bdev)); 371 goto fail; 372 } 373 374 /* Check the GUID Partition Table header size is too small */ 375 if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) { 376 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n", 377 le32_to_cpu((*gpt)->header_size), 378 sizeof(gpt_header)); 379 goto fail; 380 } 381 382 /* Check the GUID Partition Table CRC */ 383 origcrc = le32_to_cpu((*gpt)->header_crc32); 384 (*gpt)->header_crc32 = 0; 385 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); 386 387 if (crc != origcrc) { 388 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n", 389 crc, origcrc); 390 goto fail; 391 } 392 (*gpt)->header_crc32 = cpu_to_le32(origcrc); 393 394 /* Check that the my_lba entry points to the LBA that contains 395 * the GUID Partition Table */ 396 if (le64_to_cpu((*gpt)->my_lba) != lba) { 397 pr_debug("GPT my_lba incorrect: %lld != %lld\n", 398 (unsigned long long)le64_to_cpu((*gpt)->my_lba), 399 (unsigned long long)lba); 400 goto fail; 401 } 402 403 /* Check the first_usable_lba and last_usable_lba are 404 * within the disk. 405 */ 406 lastlba = last_lba(state->bdev); 407 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) { 408 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n", 409 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba), 410 (unsigned long long)lastlba); 411 goto fail; 412 } 413 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) { 414 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 415 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 416 (unsigned long long)lastlba); 417 goto fail; 418 } 419 if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) { 420 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 421 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 422 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba)); 423 goto fail; 424 } 425 /* Check that sizeof_partition_entry has the correct value */ 426 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) { 427 pr_debug("GUID Partitition Entry Size check failed.\n"); 428 goto fail; 429 } 430 431 if (!(*ptes = alloc_read_gpt_entries(state, *gpt))) 432 goto fail; 433 434 /* Check the GUID Partition Entry Array CRC */ 435 crc = efi_crc32((const unsigned char *) (*ptes), 436 le32_to_cpu((*gpt)->num_partition_entries) * 437 le32_to_cpu((*gpt)->sizeof_partition_entry)); 438 439 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { 440 pr_debug("GUID Partitition Entry Array CRC check failed.\n"); 441 goto fail_ptes; 442 } 443 444 /* We're done, all's well */ 445 return 1; 446 447 fail_ptes: 448 kfree(*ptes); 449 *ptes = NULL; 450 fail: 451 kfree(*gpt); 452 *gpt = NULL; 453 return 0; 454 } 455 456 /** 457 * is_pte_valid() - tests one PTE for validity 458 * @pte is the pte to check 459 * @lastlba is last lba of the disk 460 * 461 * Description: returns 1 if valid, 0 on error. 462 */ 463 static inline int 464 is_pte_valid(const gpt_entry *pte, const u64 lastlba) 465 { 466 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) || 467 le64_to_cpu(pte->starting_lba) > lastlba || 468 le64_to_cpu(pte->ending_lba) > lastlba) 469 return 0; 470 return 1; 471 } 472 473 /** 474 * compare_gpts() - Search disk for valid GPT headers and PTEs 475 * @pgpt is the primary GPT header 476 * @agpt is the alternate GPT header 477 * @lastlba is the last LBA number 478 * Description: Returns nothing. Sanity checks pgpt and agpt fields 479 * and prints warnings on discrepancies. 480 * 481 */ 482 static void 483 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) 484 { 485 int error_found = 0; 486 if (!pgpt || !agpt) 487 return; 488 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { 489 pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n"); 490 pr_warn("GPT:%lld != %lld\n", 491 (unsigned long long)le64_to_cpu(pgpt->my_lba), 492 (unsigned long long)le64_to_cpu(agpt->alternate_lba)); 493 error_found++; 494 } 495 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { 496 pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n"); 497 pr_warn("GPT:%lld != %lld\n", 498 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 499 (unsigned long long)le64_to_cpu(agpt->my_lba)); 500 error_found++; 501 } 502 if (le64_to_cpu(pgpt->first_usable_lba) != 503 le64_to_cpu(agpt->first_usable_lba)) { 504 pr_warn("GPT:first_usable_lbas don't match.\n"); 505 pr_warn("GPT:%lld != %lld\n", 506 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba), 507 (unsigned long long)le64_to_cpu(agpt->first_usable_lba)); 508 error_found++; 509 } 510 if (le64_to_cpu(pgpt->last_usable_lba) != 511 le64_to_cpu(agpt->last_usable_lba)) { 512 pr_warn("GPT:last_usable_lbas don't match.\n"); 513 pr_warn("GPT:%lld != %lld\n", 514 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba), 515 (unsigned long long)le64_to_cpu(agpt->last_usable_lba)); 516 error_found++; 517 } 518 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { 519 pr_warn("GPT:disk_guids don't match.\n"); 520 error_found++; 521 } 522 if (le32_to_cpu(pgpt->num_partition_entries) != 523 le32_to_cpu(agpt->num_partition_entries)) { 524 pr_warn("GPT:num_partition_entries don't match: " 525 "0x%x != 0x%x\n", 526 le32_to_cpu(pgpt->num_partition_entries), 527 le32_to_cpu(agpt->num_partition_entries)); 528 error_found++; 529 } 530 if (le32_to_cpu(pgpt->sizeof_partition_entry) != 531 le32_to_cpu(agpt->sizeof_partition_entry)) { 532 pr_warn("GPT:sizeof_partition_entry values don't match: " 533 "0x%x != 0x%x\n", 534 le32_to_cpu(pgpt->sizeof_partition_entry), 535 le32_to_cpu(agpt->sizeof_partition_entry)); 536 error_found++; 537 } 538 if (le32_to_cpu(pgpt->partition_entry_array_crc32) != 539 le32_to_cpu(agpt->partition_entry_array_crc32)) { 540 pr_warn("GPT:partition_entry_array_crc32 values don't match: " 541 "0x%x != 0x%x\n", 542 le32_to_cpu(pgpt->partition_entry_array_crc32), 543 le32_to_cpu(agpt->partition_entry_array_crc32)); 544 error_found++; 545 } 546 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { 547 pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); 548 pr_warn("GPT:%lld != %lld\n", 549 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 550 (unsigned long long)lastlba); 551 error_found++; 552 } 553 554 if (le64_to_cpu(agpt->my_lba) != lastlba) { 555 pr_warn("GPT:Alternate GPT header not at the end of the disk.\n"); 556 pr_warn("GPT:%lld != %lld\n", 557 (unsigned long long)le64_to_cpu(agpt->my_lba), 558 (unsigned long long)lastlba); 559 error_found++; 560 } 561 562 if (error_found) 563 pr_warn("GPT: Use GNU Parted to correct GPT errors.\n"); 564 return; 565 } 566 567 /** 568 * find_valid_gpt() - Search disk for valid GPT headers and PTEs 569 * @state 570 * @gpt is a GPT header ptr, filled on return. 571 * @ptes is a PTEs ptr, filled on return. 572 * Description: Returns 1 if valid, 0 on error. 573 * If valid, returns pointers to newly allocated GPT header and PTEs. 574 * Validity depends on PMBR being valid (or being overridden by the 575 * 'gpt' kernel command line option) and finding either the Primary 576 * GPT header and PTEs valid, or the Alternate GPT header and PTEs 577 * valid. If the Primary GPT header is not valid, the Alternate GPT header 578 * is not checked unless the 'gpt' kernel command line option is passed. 579 * This protects against devices which misreport their size, and forces 580 * the user to decide to use the Alternate GPT. 581 */ 582 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt, 583 gpt_entry **ptes) 584 { 585 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; 586 gpt_header *pgpt = NULL, *agpt = NULL; 587 gpt_entry *pptes = NULL, *aptes = NULL; 588 legacy_mbr *legacymbr; 589 sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9; 590 u64 lastlba; 591 592 if (!ptes) 593 return 0; 594 595 lastlba = last_lba(state->bdev); 596 if (!force_gpt) { 597 /* This will be added to the EFI Spec. per Intel after v1.02. */ 598 legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL); 599 if (!legacymbr) 600 goto fail; 601 602 read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr)); 603 good_pmbr = is_pmbr_valid(legacymbr, total_sectors); 604 kfree(legacymbr); 605 606 if (!good_pmbr) 607 goto fail; 608 609 pr_debug("Device has a %s MBR\n", 610 good_pmbr == GPT_MBR_PROTECTIVE ? 611 "protective" : "hybrid"); 612 } 613 614 good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA, 615 &pgpt, &pptes); 616 if (good_pgpt) 617 good_agpt = is_gpt_valid(state, 618 le64_to_cpu(pgpt->alternate_lba), 619 &agpt, &aptes); 620 if (!good_agpt && force_gpt) 621 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes); 622 623 /* The obviously unsuccessful case */ 624 if (!good_pgpt && !good_agpt) 625 goto fail; 626 627 compare_gpts(pgpt, agpt, lastlba); 628 629 /* The good cases */ 630 if (good_pgpt) { 631 *gpt = pgpt; 632 *ptes = pptes; 633 kfree(agpt); 634 kfree(aptes); 635 if (!good_agpt) 636 pr_warn("Alternate GPT is invalid, using primary GPT.\n"); 637 return 1; 638 } 639 else if (good_agpt) { 640 *gpt = agpt; 641 *ptes = aptes; 642 kfree(pgpt); 643 kfree(pptes); 644 pr_warn("Primary GPT is invalid, using alternate GPT.\n"); 645 return 1; 646 } 647 648 fail: 649 kfree(pgpt); 650 kfree(agpt); 651 kfree(pptes); 652 kfree(aptes); 653 *gpt = NULL; 654 *ptes = NULL; 655 return 0; 656 } 657 658 /** 659 * efi_partition(struct parsed_partitions *state) 660 * @state 661 * 662 * Description: called from check.c, if the disk contains GPT 663 * partitions, sets up partition entries in the kernel. 664 * 665 * If the first block on the disk is a legacy MBR, 666 * it will get handled by msdos_partition(). 667 * If it's a Protective MBR, we'll handle it here. 668 * 669 * We do not create a Linux partition for GPT, but 670 * only for the actual data partitions. 671 * Returns: 672 * -1 if unable to read the partition table 673 * 0 if this isn't our partition table 674 * 1 if successful 675 * 676 */ 677 int efi_partition(struct parsed_partitions *state) 678 { 679 gpt_header *gpt = NULL; 680 gpt_entry *ptes = NULL; 681 u32 i; 682 unsigned ssz = bdev_logical_block_size(state->bdev) / 512; 683 684 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) { 685 kfree(gpt); 686 kfree(ptes); 687 return 0; 688 } 689 690 pr_debug("GUID Partition Table is valid! Yea!\n"); 691 692 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { 693 struct partition_meta_info *info; 694 unsigned label_count = 0; 695 unsigned label_max; 696 u64 start = le64_to_cpu(ptes[i].starting_lba); 697 u64 size = le64_to_cpu(ptes[i].ending_lba) - 698 le64_to_cpu(ptes[i].starting_lba) + 1ULL; 699 700 if (!is_pte_valid(&ptes[i], last_lba(state->bdev))) 701 continue; 702 703 put_partition(state, i+1, start * ssz, size * ssz); 704 705 /* If this is a RAID volume, tell md */ 706 if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID)) 707 state->parts[i + 1].flags = ADDPART_FLAG_RAID; 708 709 info = &state->parts[i + 1].info; 710 efi_guid_unparse(&ptes[i].unique_partition_guid, info->uuid); 711 712 /* Naively convert UTF16-LE to 7 bits. */ 713 label_max = min(sizeof(info->volname) - 1, 714 sizeof(ptes[i].partition_name)); 715 info->volname[label_max] = 0; 716 while (label_count < label_max) { 717 u8 c = ptes[i].partition_name[label_count] & 0xff; 718 if (c && !isprint(c)) 719 c = '!'; 720 info->volname[label_count] = c; 721 label_count++; 722 } 723 state->parts[i + 1].has_info = true; 724 } 725 kfree(ptes); 726 kfree(gpt); 727 strlcat(state->pp_buf, "\n", PAGE_SIZE); 728 return 1; 729 } 730