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/kernel.h> 100 #include <linux/crc32.h> 101 #include <linux/ctype.h> 102 #include <linux/math64.h> 103 #include <linux/slab.h> 104 #include "check.h" 105 #include "efi.h" 106 107 /* This allows a kernel command line option 'gpt' to override 108 * the test for invalid PMBR. Not __initdata because reloading 109 * the partition tables happens after init too. 110 */ 111 static int force_gpt; 112 static int __init 113 force_gpt_fn(char *str) 114 { 115 force_gpt = 1; 116 return 1; 117 } 118 __setup("gpt", force_gpt_fn); 119 120 121 /** 122 * efi_crc32() - EFI version of crc32 function 123 * @buf: buffer to calculate crc32 of 124 * @len: length of buf 125 * 126 * Description: Returns EFI-style CRC32 value for @buf 127 * 128 * This function uses the little endian Ethernet polynomial 129 * but seeds the function with ~0, and xor's with ~0 at the end. 130 * Note, the EFI Specification, v1.02, has a reference to 131 * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). 132 */ 133 static inline u32 134 efi_crc32(const void *buf, unsigned long len) 135 { 136 return (crc32(~0L, buf, len) ^ ~0L); 137 } 138 139 /** 140 * last_lba(): return number of last logical block of device 141 * @bdev: block device 142 * 143 * Description: Returns last LBA value on success, 0 on error. 144 * This is stored (by sd and ide-geometry) in 145 * the part[0] entry for this disk, and is the number of 146 * physical sectors available on the disk. 147 */ 148 static u64 last_lba(struct block_device *bdev) 149 { 150 if (!bdev || !bdev->bd_inode) 151 return 0; 152 return div_u64(bdev->bd_inode->i_size, 153 bdev_logical_block_size(bdev)) - 1ULL; 154 } 155 156 static inline int pmbr_part_valid(gpt_mbr_record *part) 157 { 158 if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT) 159 goto invalid; 160 161 /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */ 162 if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA) 163 goto invalid; 164 165 return GPT_MBR_PROTECTIVE; 166 invalid: 167 return 0; 168 } 169 170 /** 171 * is_pmbr_valid(): test Protective MBR for validity 172 * @mbr: pointer to a legacy mbr structure 173 * @total_sectors: amount of sectors in the device 174 * 175 * Description: Checks for a valid protective or hybrid 176 * master boot record (MBR). The validity of a pMBR depends 177 * on all of the following properties: 178 * 1) MSDOS signature is in the last two bytes of the MBR 179 * 2) One partition of type 0xEE is found 180 * 181 * In addition, a hybrid MBR will have up to three additional 182 * primary partitions, which point to the same space that's 183 * marked out by up to three GPT partitions. 184 * 185 * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or 186 * GPT_MBR_HYBRID depending on the device layout. 187 */ 188 static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors) 189 { 190 uint32_t sz = 0; 191 int i, part = 0, ret = 0; /* invalid by default */ 192 193 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE) 194 goto done; 195 196 for (i = 0; i < 4; i++) { 197 ret = pmbr_part_valid(&mbr->partition_record[i]); 198 if (ret == GPT_MBR_PROTECTIVE) { 199 part = i; 200 /* 201 * Ok, we at least know that there's a protective MBR, 202 * now check if there are other partition types for 203 * hybrid MBR. 204 */ 205 goto check_hybrid; 206 } 207 } 208 209 if (ret != GPT_MBR_PROTECTIVE) 210 goto done; 211 check_hybrid: 212 for (i = 0; i < 4; i++) 213 if ((mbr->partition_record[i].os_type != 214 EFI_PMBR_OSTYPE_EFI_GPT) && 215 (mbr->partition_record[i].os_type != 0x00)) 216 ret = GPT_MBR_HYBRID; 217 218 /* 219 * Protective MBRs take up the lesser of the whole disk 220 * or 2 TiB (32bit LBA), ignoring the rest of the disk. 221 * Some partitioning programs, nonetheless, choose to set 222 * the size to the maximum 32-bit limitation, disregarding 223 * the disk size. 224 * 225 * Hybrid MBRs do not necessarily comply with this. 226 * 227 * Consider a bad value here to be a warning to support dd'ing 228 * an image from a smaller disk to a larger disk. 229 */ 230 if (ret == GPT_MBR_PROTECTIVE) { 231 sz = le32_to_cpu(mbr->partition_record[part].size_in_lba); 232 if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF) 233 pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n", 234 sz, min_t(uint32_t, 235 total_sectors - 1, 0xFFFFFFFF)); 236 } 237 done: 238 return ret; 239 } 240 241 /** 242 * read_lba(): Read bytes from disk, starting at given LBA 243 * @state: disk parsed partitions 244 * @lba: the Logical Block Address of the partition table 245 * @buffer: destination buffer 246 * @count: bytes to read 247 * 248 * Description: Reads @count bytes from @state->bdev into @buffer. 249 * Returns number of bytes read on success, 0 on error. 250 */ 251 static size_t read_lba(struct parsed_partitions *state, 252 u64 lba, u8 *buffer, size_t count) 253 { 254 size_t totalreadcount = 0; 255 struct block_device *bdev = state->bdev; 256 sector_t n = lba * (bdev_logical_block_size(bdev) / 512); 257 258 if (!buffer || lba > last_lba(bdev)) 259 return 0; 260 261 while (count) { 262 int copied = 512; 263 Sector sect; 264 unsigned char *data = read_part_sector(state, n++, §); 265 if (!data) 266 break; 267 if (copied > count) 268 copied = count; 269 memcpy(buffer, data, copied); 270 put_dev_sector(sect); 271 buffer += copied; 272 totalreadcount +=copied; 273 count -= copied; 274 } 275 return totalreadcount; 276 } 277 278 /** 279 * alloc_read_gpt_entries(): reads partition entries from disk 280 * @state: disk parsed partitions 281 * @gpt: GPT header 282 * 283 * Description: Returns ptes on success, NULL on error. 284 * Allocates space for PTEs based on information found in @gpt. 285 * Notes: remember to free pte when you're done! 286 */ 287 static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state, 288 gpt_header *gpt) 289 { 290 size_t count; 291 gpt_entry *pte; 292 293 if (!gpt) 294 return NULL; 295 296 count = (size_t)le32_to_cpu(gpt->num_partition_entries) * 297 le32_to_cpu(gpt->sizeof_partition_entry); 298 if (!count) 299 return NULL; 300 pte = kmalloc(count, GFP_KERNEL); 301 if (!pte) 302 return NULL; 303 304 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba), 305 (u8 *) pte, count) < count) { 306 kfree(pte); 307 pte=NULL; 308 return NULL; 309 } 310 return pte; 311 } 312 313 /** 314 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk 315 * @state: disk parsed partitions 316 * @lba: the Logical Block Address of the partition table 317 * 318 * Description: returns GPT header on success, NULL on error. Allocates 319 * and fills a GPT header starting at @ from @state->bdev. 320 * Note: remember to free gpt when finished with it. 321 */ 322 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state, 323 u64 lba) 324 { 325 gpt_header *gpt; 326 unsigned ssz = bdev_logical_block_size(state->bdev); 327 328 gpt = kmalloc(ssz, GFP_KERNEL); 329 if (!gpt) 330 return NULL; 331 332 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) { 333 kfree(gpt); 334 gpt=NULL; 335 return NULL; 336 } 337 338 return gpt; 339 } 340 341 /** 342 * is_gpt_valid() - tests one GPT header and PTEs for validity 343 * @state: disk parsed partitions 344 * @lba: logical block address of the GPT header to test 345 * @gpt: GPT header ptr, filled on return. 346 * @ptes: PTEs ptr, filled on return. 347 * 348 * Description: returns 1 if valid, 0 on error. 349 * If valid, returns pointers to newly allocated GPT header and PTEs. 350 */ 351 static int is_gpt_valid(struct parsed_partitions *state, u64 lba, 352 gpt_header **gpt, gpt_entry **ptes) 353 { 354 u32 crc, origcrc; 355 u64 lastlba, pt_size; 356 357 if (!ptes) 358 return 0; 359 if (!(*gpt = alloc_read_gpt_header(state, lba))) 360 return 0; 361 362 /* Check the GUID Partition Table signature */ 363 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { 364 pr_debug("GUID Partition Table Header signature is wrong:" 365 "%lld != %lld\n", 366 (unsigned long long)le64_to_cpu((*gpt)->signature), 367 (unsigned long long)GPT_HEADER_SIGNATURE); 368 goto fail; 369 } 370 371 /* Check the GUID Partition Table header size is too big */ 372 if (le32_to_cpu((*gpt)->header_size) > 373 bdev_logical_block_size(state->bdev)) { 374 pr_debug("GUID Partition Table Header size is too large: %u > %u\n", 375 le32_to_cpu((*gpt)->header_size), 376 bdev_logical_block_size(state->bdev)); 377 goto fail; 378 } 379 380 /* Check the GUID Partition Table header size is too small */ 381 if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) { 382 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n", 383 le32_to_cpu((*gpt)->header_size), 384 sizeof(gpt_header)); 385 goto fail; 386 } 387 388 /* Check the GUID Partition Table CRC */ 389 origcrc = le32_to_cpu((*gpt)->header_crc32); 390 (*gpt)->header_crc32 = 0; 391 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); 392 393 if (crc != origcrc) { 394 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n", 395 crc, origcrc); 396 goto fail; 397 } 398 (*gpt)->header_crc32 = cpu_to_le32(origcrc); 399 400 /* Check that the my_lba entry points to the LBA that contains 401 * the GUID Partition Table */ 402 if (le64_to_cpu((*gpt)->my_lba) != lba) { 403 pr_debug("GPT my_lba incorrect: %lld != %lld\n", 404 (unsigned long long)le64_to_cpu((*gpt)->my_lba), 405 (unsigned long long)lba); 406 goto fail; 407 } 408 409 /* Check the first_usable_lba and last_usable_lba are 410 * within the disk. 411 */ 412 lastlba = last_lba(state->bdev); 413 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) { 414 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n", 415 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba), 416 (unsigned long long)lastlba); 417 goto fail; 418 } 419 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) { 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)lastlba); 423 goto fail; 424 } 425 if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) { 426 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 427 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 428 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba)); 429 goto fail; 430 } 431 /* Check that sizeof_partition_entry has the correct value */ 432 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) { 433 pr_debug("GUID Partition Entry Size check failed.\n"); 434 goto fail; 435 } 436 437 /* Sanity check partition table size */ 438 pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) * 439 le32_to_cpu((*gpt)->sizeof_partition_entry); 440 if (pt_size > KMALLOC_MAX_SIZE) { 441 pr_debug("GUID Partition Table is too large: %llu > %lu bytes\n", 442 (unsigned long long)pt_size, KMALLOC_MAX_SIZE); 443 goto fail; 444 } 445 446 if (!(*ptes = alloc_read_gpt_entries(state, *gpt))) 447 goto fail; 448 449 /* Check the GUID Partition Entry Array CRC */ 450 crc = efi_crc32((const unsigned char *) (*ptes), pt_size); 451 452 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { 453 pr_debug("GUID Partition Entry Array CRC check failed.\n"); 454 goto fail_ptes; 455 } 456 457 /* We're done, all's well */ 458 return 1; 459 460 fail_ptes: 461 kfree(*ptes); 462 *ptes = NULL; 463 fail: 464 kfree(*gpt); 465 *gpt = NULL; 466 return 0; 467 } 468 469 /** 470 * is_pte_valid() - tests one PTE for validity 471 * @pte:pte to check 472 * @lastlba: last lba of the disk 473 * 474 * Description: returns 1 if valid, 0 on error. 475 */ 476 static inline int 477 is_pte_valid(const gpt_entry *pte, const u64 lastlba) 478 { 479 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) || 480 le64_to_cpu(pte->starting_lba) > lastlba || 481 le64_to_cpu(pte->ending_lba) > lastlba) 482 return 0; 483 return 1; 484 } 485 486 /** 487 * compare_gpts() - Search disk for valid GPT headers and PTEs 488 * @pgpt: primary GPT header 489 * @agpt: alternate GPT header 490 * @lastlba: last LBA number 491 * 492 * Description: Returns nothing. Sanity checks pgpt and agpt fields 493 * and prints warnings on discrepancies. 494 * 495 */ 496 static void 497 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) 498 { 499 int error_found = 0; 500 if (!pgpt || !agpt) 501 return; 502 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { 503 pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n"); 504 pr_warn("GPT:%lld != %lld\n", 505 (unsigned long long)le64_to_cpu(pgpt->my_lba), 506 (unsigned long long)le64_to_cpu(agpt->alternate_lba)); 507 error_found++; 508 } 509 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { 510 pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n"); 511 pr_warn("GPT:%lld != %lld\n", 512 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 513 (unsigned long long)le64_to_cpu(agpt->my_lba)); 514 error_found++; 515 } 516 if (le64_to_cpu(pgpt->first_usable_lba) != 517 le64_to_cpu(agpt->first_usable_lba)) { 518 pr_warn("GPT:first_usable_lbas don't match.\n"); 519 pr_warn("GPT:%lld != %lld\n", 520 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba), 521 (unsigned long long)le64_to_cpu(agpt->first_usable_lba)); 522 error_found++; 523 } 524 if (le64_to_cpu(pgpt->last_usable_lba) != 525 le64_to_cpu(agpt->last_usable_lba)) { 526 pr_warn("GPT:last_usable_lbas don't match.\n"); 527 pr_warn("GPT:%lld != %lld\n", 528 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba), 529 (unsigned long long)le64_to_cpu(agpt->last_usable_lba)); 530 error_found++; 531 } 532 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { 533 pr_warn("GPT:disk_guids don't match.\n"); 534 error_found++; 535 } 536 if (le32_to_cpu(pgpt->num_partition_entries) != 537 le32_to_cpu(agpt->num_partition_entries)) { 538 pr_warn("GPT:num_partition_entries don't match: " 539 "0x%x != 0x%x\n", 540 le32_to_cpu(pgpt->num_partition_entries), 541 le32_to_cpu(agpt->num_partition_entries)); 542 error_found++; 543 } 544 if (le32_to_cpu(pgpt->sizeof_partition_entry) != 545 le32_to_cpu(agpt->sizeof_partition_entry)) { 546 pr_warn("GPT:sizeof_partition_entry values don't match: " 547 "0x%x != 0x%x\n", 548 le32_to_cpu(pgpt->sizeof_partition_entry), 549 le32_to_cpu(agpt->sizeof_partition_entry)); 550 error_found++; 551 } 552 if (le32_to_cpu(pgpt->partition_entry_array_crc32) != 553 le32_to_cpu(agpt->partition_entry_array_crc32)) { 554 pr_warn("GPT:partition_entry_array_crc32 values don't match: " 555 "0x%x != 0x%x\n", 556 le32_to_cpu(pgpt->partition_entry_array_crc32), 557 le32_to_cpu(agpt->partition_entry_array_crc32)); 558 error_found++; 559 } 560 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { 561 pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); 562 pr_warn("GPT:%lld != %lld\n", 563 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 564 (unsigned long long)lastlba); 565 error_found++; 566 } 567 568 if (le64_to_cpu(agpt->my_lba) != lastlba) { 569 pr_warn("GPT:Alternate GPT header not at the end of the disk.\n"); 570 pr_warn("GPT:%lld != %lld\n", 571 (unsigned long long)le64_to_cpu(agpt->my_lba), 572 (unsigned long long)lastlba); 573 error_found++; 574 } 575 576 if (error_found) 577 pr_warn("GPT: Use GNU Parted to correct GPT errors.\n"); 578 return; 579 } 580 581 /** 582 * find_valid_gpt() - Search disk for valid GPT headers and PTEs 583 * @state: disk parsed partitions 584 * @gpt: GPT header ptr, filled on return. 585 * @ptes: PTEs ptr, filled on return. 586 * 587 * Description: Returns 1 if valid, 0 on error. 588 * If valid, returns pointers to newly allocated GPT header and PTEs. 589 * Validity depends on PMBR being valid (or being overridden by the 590 * 'gpt' kernel command line option) and finding either the Primary 591 * GPT header and PTEs valid, or the Alternate GPT header and PTEs 592 * valid. If the Primary GPT header is not valid, the Alternate GPT header 593 * is not checked unless the 'gpt' kernel command line option is passed. 594 * This protects against devices which misreport their size, and forces 595 * the user to decide to use the Alternate GPT. 596 */ 597 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt, 598 gpt_entry **ptes) 599 { 600 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; 601 gpt_header *pgpt = NULL, *agpt = NULL; 602 gpt_entry *pptes = NULL, *aptes = NULL; 603 legacy_mbr *legacymbr; 604 sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9; 605 u64 lastlba; 606 607 if (!ptes) 608 return 0; 609 610 lastlba = last_lba(state->bdev); 611 if (!force_gpt) { 612 /* This will be added to the EFI Spec. per Intel after v1.02. */ 613 legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL); 614 if (!legacymbr) 615 goto fail; 616 617 read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr)); 618 good_pmbr = is_pmbr_valid(legacymbr, total_sectors); 619 kfree(legacymbr); 620 621 if (!good_pmbr) 622 goto fail; 623 624 pr_debug("Device has a %s MBR\n", 625 good_pmbr == GPT_MBR_PROTECTIVE ? 626 "protective" : "hybrid"); 627 } 628 629 good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA, 630 &pgpt, &pptes); 631 if (good_pgpt) 632 good_agpt = is_gpt_valid(state, 633 le64_to_cpu(pgpt->alternate_lba), 634 &agpt, &aptes); 635 if (!good_agpt && force_gpt) 636 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes); 637 638 /* The obviously unsuccessful case */ 639 if (!good_pgpt && !good_agpt) 640 goto fail; 641 642 compare_gpts(pgpt, agpt, lastlba); 643 644 /* The good cases */ 645 if (good_pgpt) { 646 *gpt = pgpt; 647 *ptes = pptes; 648 kfree(agpt); 649 kfree(aptes); 650 if (!good_agpt) 651 pr_warn("Alternate GPT is invalid, using primary GPT.\n"); 652 return 1; 653 } 654 else if (good_agpt) { 655 *gpt = agpt; 656 *ptes = aptes; 657 kfree(pgpt); 658 kfree(pptes); 659 pr_warn("Primary GPT is invalid, using alternate GPT.\n"); 660 return 1; 661 } 662 663 fail: 664 kfree(pgpt); 665 kfree(agpt); 666 kfree(pptes); 667 kfree(aptes); 668 *gpt = NULL; 669 *ptes = NULL; 670 return 0; 671 } 672 673 /** 674 * efi_partition(struct parsed_partitions *state) 675 * @state: disk parsed partitions 676 * 677 * Description: called from check.c, if the disk contains GPT 678 * partitions, sets up partition entries in the kernel. 679 * 680 * If the first block on the disk is a legacy MBR, 681 * it will get handled by msdos_partition(). 682 * If it's a Protective MBR, we'll handle it here. 683 * 684 * We do not create a Linux partition for GPT, but 685 * only for the actual data partitions. 686 * Returns: 687 * -1 if unable to read the partition table 688 * 0 if this isn't our partition table 689 * 1 if successful 690 * 691 */ 692 int efi_partition(struct parsed_partitions *state) 693 { 694 gpt_header *gpt = NULL; 695 gpt_entry *ptes = NULL; 696 u32 i; 697 unsigned ssz = bdev_logical_block_size(state->bdev) / 512; 698 699 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) { 700 kfree(gpt); 701 kfree(ptes); 702 return 0; 703 } 704 705 pr_debug("GUID Partition Table is valid! Yea!\n"); 706 707 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { 708 struct partition_meta_info *info; 709 unsigned label_count = 0; 710 unsigned label_max; 711 u64 start = le64_to_cpu(ptes[i].starting_lba); 712 u64 size = le64_to_cpu(ptes[i].ending_lba) - 713 le64_to_cpu(ptes[i].starting_lba) + 1ULL; 714 715 if (!is_pte_valid(&ptes[i], last_lba(state->bdev))) 716 continue; 717 718 put_partition(state, i+1, start * ssz, size * ssz); 719 720 /* If this is a RAID volume, tell md */ 721 if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID)) 722 state->parts[i + 1].flags = ADDPART_FLAG_RAID; 723 724 info = &state->parts[i + 1].info; 725 efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid); 726 727 /* Naively convert UTF16-LE to 7 bits. */ 728 label_max = min(ARRAY_SIZE(info->volname) - 1, 729 ARRAY_SIZE(ptes[i].partition_name)); 730 info->volname[label_max] = 0; 731 while (label_count < label_max) { 732 u8 c = ptes[i].partition_name[label_count] & 0xff; 733 if (c && !isprint(c)) 734 c = '!'; 735 info->volname[label_count] = c; 736 label_count++; 737 } 738 state->parts[i + 1].has_info = true; 739 } 740 kfree(ptes); 741 kfree(gpt); 742 strlcat(state->pp_buf, "\n", PAGE_SIZE); 743 return 1; 744 } 745