1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /************************************************************ 3 * EFI GUID Partition Table handling 4 * 5 * http://www.uefi.org/specs/ 6 * http://www.intel.com/technology/efi/ 7 * 8 * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com> 9 * Copyright 2000,2001,2002,2004 Dell Inc. 10 * 11 * TODO: 12 * 13 * Changelog: 14 * Mon August 5th, 2013 Davidlohr Bueso <davidlohr@hp.com> 15 * - detect hybrid MBRs, tighter pMBR checking & cleanups. 16 * 17 * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com> 18 * - test for valid PMBR and valid PGPT before ever reading 19 * AGPT, allow override with 'gpt' kernel command line option. 20 * - check for first/last_usable_lba outside of size of disk 21 * 22 * Tue Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com> 23 * - Ported to 2.5.7-pre1 and 2.5.7-dj2 24 * - Applied patch to avoid fault in alternate header handling 25 * - cleaned up find_valid_gpt 26 * - On-disk structure and copy in memory is *always* LE now - 27 * swab fields as needed 28 * - remove print_gpt_header() 29 * - only use first max_p partition entries, to keep the kernel minor number 30 * and partition numbers tied. 31 * 32 * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com> 33 * - Removed __PRIPTR_PREFIX - not being used 34 * 35 * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com> 36 * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied 37 * 38 * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com> 39 * - Added compare_gpts(). 40 * - moved le_efi_guid_to_cpus() back into this file. GPT is the only 41 * thing that keeps EFI GUIDs on disk. 42 * - Changed gpt structure names and members to be simpler and more Linux-like. 43 * 44 * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com> 45 * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck 46 * 47 * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com> 48 * - Changed function comments to DocBook style per Andreas Dilger suggestion. 49 * 50 * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com> 51 * - Change read_lba() to use the page cache per Al Viro's work. 52 * - print u64s properly on all architectures 53 * - fixed debug_printk(), now Dprintk() 54 * 55 * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com> 56 * - Style cleanups 57 * - made most functions static 58 * - Endianness addition 59 * - remove test for second alternate header, as it's not per spec, 60 * and is unnecessary. There's now a method to read/write the last 61 * sector of an odd-sized disk from user space. No tools have ever 62 * been released which used this code, so it's effectively dead. 63 * - Per Asit Mallick of Intel, added a test for a valid PMBR. 64 * - Added kernel command line option 'gpt' to override valid PMBR test. 65 * 66 * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com> 67 * - added devfs volume UUID support (/dev/volumes/uuids) for 68 * mounting file systems by the partition GUID. 69 * 70 * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com> 71 * - Moved crc32() to linux/lib, added efi_crc32(). 72 * 73 * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com> 74 * - Replaced Intel's CRC32 function with an equivalent 75 * non-license-restricted version. 76 * 77 * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com> 78 * - Fixed the last_lba() call to return the proper last block 79 * 80 * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com> 81 * - Thanks to Andries Brouwer for his debugging assistance. 82 * - Code works, detects all the partitions. 83 * 84 ************************************************************/ 85 #include <linux/kernel.h> 86 #include <linux/crc32.h> 87 #include <linux/ctype.h> 88 #include <linux/math64.h> 89 #include <linux/slab.h> 90 #include "check.h" 91 #include "efi.h" 92 93 /* This allows a kernel command line option 'gpt' to override 94 * the test for invalid PMBR. Not __initdata because reloading 95 * the partition tables happens after init too. 96 */ 97 static int force_gpt; 98 static int __init 99 force_gpt_fn(char *str) 100 { 101 force_gpt = 1; 102 return 1; 103 } 104 __setup("gpt", force_gpt_fn); 105 106 107 /** 108 * efi_crc32() - EFI version of crc32 function 109 * @buf: buffer to calculate crc32 of 110 * @len: length of buf 111 * 112 * Description: Returns EFI-style CRC32 value for @buf 113 * 114 * This function uses the little endian Ethernet polynomial 115 * but seeds the function with ~0, and xor's with ~0 at the end. 116 * Note, the EFI Specification, v1.02, has a reference to 117 * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). 118 */ 119 static inline u32 120 efi_crc32(const void *buf, unsigned long len) 121 { 122 return (crc32(~0L, buf, len) ^ ~0L); 123 } 124 125 /** 126 * last_lba(): return number of last logical block of device 127 * @disk: block device 128 * 129 * Description: Returns last LBA value on success, 0 on error. 130 * This is stored (by sd and ide-geometry) in 131 * the part[0] entry for this disk, and is the number of 132 * physical sectors available on the disk. 133 */ 134 static u64 last_lba(struct gendisk *disk) 135 { 136 return div_u64(disk->part0->bd_inode->i_size, 137 queue_logical_block_size(disk->queue)) - 1ULL; 138 } 139 140 static inline int pmbr_part_valid(gpt_mbr_record *part) 141 { 142 if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT) 143 goto invalid; 144 145 /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */ 146 if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA) 147 goto invalid; 148 149 return GPT_MBR_PROTECTIVE; 150 invalid: 151 return 0; 152 } 153 154 /** 155 * is_pmbr_valid(): test Protective MBR for validity 156 * @mbr: pointer to a legacy mbr structure 157 * @total_sectors: amount of sectors in the device 158 * 159 * Description: Checks for a valid protective or hybrid 160 * master boot record (MBR). The validity of a pMBR depends 161 * on all of the following properties: 162 * 1) MSDOS signature is in the last two bytes of the MBR 163 * 2) One partition of type 0xEE is found 164 * 165 * In addition, a hybrid MBR will have up to three additional 166 * primary partitions, which point to the same space that's 167 * marked out by up to three GPT partitions. 168 * 169 * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or 170 * GPT_MBR_HYBRID depending on the device layout. 171 */ 172 static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors) 173 { 174 uint32_t sz = 0; 175 int i, part = 0, ret = 0; /* invalid by default */ 176 177 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE) 178 goto done; 179 180 for (i = 0; i < 4; i++) { 181 ret = pmbr_part_valid(&mbr->partition_record[i]); 182 if (ret == GPT_MBR_PROTECTIVE) { 183 part = i; 184 /* 185 * Ok, we at least know that there's a protective MBR, 186 * now check if there are other partition types for 187 * hybrid MBR. 188 */ 189 goto check_hybrid; 190 } 191 } 192 193 if (ret != GPT_MBR_PROTECTIVE) 194 goto done; 195 check_hybrid: 196 for (i = 0; i < 4; i++) 197 if ((mbr->partition_record[i].os_type != 198 EFI_PMBR_OSTYPE_EFI_GPT) && 199 (mbr->partition_record[i].os_type != 0x00)) 200 ret = GPT_MBR_HYBRID; 201 202 /* 203 * Protective MBRs take up the lesser of the whole disk 204 * or 2 TiB (32bit LBA), ignoring the rest of the disk. 205 * Some partitioning programs, nonetheless, choose to set 206 * the size to the maximum 32-bit limitation, disregarding 207 * the disk size. 208 * 209 * Hybrid MBRs do not necessarily comply with this. 210 * 211 * Consider a bad value here to be a warning to support dd'ing 212 * an image from a smaller disk to a larger disk. 213 */ 214 if (ret == GPT_MBR_PROTECTIVE) { 215 sz = le32_to_cpu(mbr->partition_record[part].size_in_lba); 216 if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF) 217 pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n", 218 sz, min_t(uint32_t, 219 total_sectors - 1, 0xFFFFFFFF)); 220 } 221 done: 222 return ret; 223 } 224 225 /** 226 * read_lba(): Read bytes from disk, starting at given LBA 227 * @state: disk parsed partitions 228 * @lba: the Logical Block Address of the partition table 229 * @buffer: destination buffer 230 * @count: bytes to read 231 * 232 * Description: Reads @count bytes from @state->disk into @buffer. 233 * Returns number of bytes read on success, 0 on error. 234 */ 235 static size_t read_lba(struct parsed_partitions *state, 236 u64 lba, u8 *buffer, size_t count) 237 { 238 size_t totalreadcount = 0; 239 sector_t n = lba * 240 (queue_logical_block_size(state->disk->queue) / 512); 241 242 if (!buffer || lba > last_lba(state->disk)) 243 return 0; 244 245 while (count) { 246 int copied = 512; 247 Sector sect; 248 unsigned char *data = read_part_sector(state, n++, §); 249 if (!data) 250 break; 251 if (copied > count) 252 copied = count; 253 memcpy(buffer, data, copied); 254 put_dev_sector(sect); 255 buffer += copied; 256 totalreadcount +=copied; 257 count -= copied; 258 } 259 return totalreadcount; 260 } 261 262 /** 263 * alloc_read_gpt_entries(): reads partition entries from disk 264 * @state: disk parsed partitions 265 * @gpt: GPT header 266 * 267 * Description: Returns ptes on success, NULL on error. 268 * Allocates space for PTEs based on information found in @gpt. 269 * Notes: remember to free pte when you're done! 270 */ 271 static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state, 272 gpt_header *gpt) 273 { 274 size_t count; 275 gpt_entry *pte; 276 277 if (!gpt) 278 return NULL; 279 280 count = (size_t)le32_to_cpu(gpt->num_partition_entries) * 281 le32_to_cpu(gpt->sizeof_partition_entry); 282 if (!count) 283 return NULL; 284 pte = kmalloc(count, GFP_KERNEL); 285 if (!pte) 286 return NULL; 287 288 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba), 289 (u8 *) pte, count) < count) { 290 kfree(pte); 291 pte=NULL; 292 return NULL; 293 } 294 return pte; 295 } 296 297 /** 298 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk 299 * @state: disk parsed partitions 300 * @lba: the Logical Block Address of the partition table 301 * 302 * Description: returns GPT header on success, NULL on error. Allocates 303 * and fills a GPT header starting at @ from @state->disk. 304 * Note: remember to free gpt when finished with it. 305 */ 306 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state, 307 u64 lba) 308 { 309 gpt_header *gpt; 310 unsigned ssz = queue_logical_block_size(state->disk->queue); 311 312 gpt = kmalloc(ssz, GFP_KERNEL); 313 if (!gpt) 314 return NULL; 315 316 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) { 317 kfree(gpt); 318 gpt=NULL; 319 return NULL; 320 } 321 322 return gpt; 323 } 324 325 /** 326 * is_gpt_valid() - tests one GPT header and PTEs for validity 327 * @state: disk parsed partitions 328 * @lba: logical block address of the GPT header to test 329 * @gpt: GPT header ptr, filled on return. 330 * @ptes: PTEs ptr, filled on return. 331 * 332 * Description: returns 1 if valid, 0 on error. 333 * If valid, returns pointers to newly allocated GPT header and PTEs. 334 */ 335 static int is_gpt_valid(struct parsed_partitions *state, u64 lba, 336 gpt_header **gpt, gpt_entry **ptes) 337 { 338 u32 crc, origcrc; 339 u64 lastlba, pt_size; 340 341 if (!ptes) 342 return 0; 343 if (!(*gpt = alloc_read_gpt_header(state, lba))) 344 return 0; 345 346 /* Check the GUID Partition Table signature */ 347 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { 348 pr_debug("GUID Partition Table Header signature is wrong:" 349 "%lld != %lld\n", 350 (unsigned long long)le64_to_cpu((*gpt)->signature), 351 (unsigned long long)GPT_HEADER_SIGNATURE); 352 goto fail; 353 } 354 355 /* Check the GUID Partition Table header size is too big */ 356 if (le32_to_cpu((*gpt)->header_size) > 357 queue_logical_block_size(state->disk->queue)) { 358 pr_debug("GUID Partition Table Header size is too large: %u > %u\n", 359 le32_to_cpu((*gpt)->header_size), 360 queue_logical_block_size(state->disk->queue)); 361 goto fail; 362 } 363 364 /* Check the GUID Partition Table header size is too small */ 365 if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) { 366 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n", 367 le32_to_cpu((*gpt)->header_size), 368 sizeof(gpt_header)); 369 goto fail; 370 } 371 372 /* Check the GUID Partition Table CRC */ 373 origcrc = le32_to_cpu((*gpt)->header_crc32); 374 (*gpt)->header_crc32 = 0; 375 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); 376 377 if (crc != origcrc) { 378 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n", 379 crc, origcrc); 380 goto fail; 381 } 382 (*gpt)->header_crc32 = cpu_to_le32(origcrc); 383 384 /* Check that the my_lba entry points to the LBA that contains 385 * the GUID Partition Table */ 386 if (le64_to_cpu((*gpt)->my_lba) != lba) { 387 pr_debug("GPT my_lba incorrect: %lld != %lld\n", 388 (unsigned long long)le64_to_cpu((*gpt)->my_lba), 389 (unsigned long long)lba); 390 goto fail; 391 } 392 393 /* Check the first_usable_lba and last_usable_lba are 394 * within the disk. 395 */ 396 lastlba = last_lba(state->disk); 397 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) { 398 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n", 399 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba), 400 (unsigned long long)lastlba); 401 goto fail; 402 } 403 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) { 404 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 405 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 406 (unsigned long long)lastlba); 407 goto fail; 408 } 409 if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) { 410 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", 411 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), 412 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba)); 413 goto fail; 414 } 415 /* Check that sizeof_partition_entry has the correct value */ 416 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) { 417 pr_debug("GUID Partition Entry Size check failed.\n"); 418 goto fail; 419 } 420 421 /* Sanity check partition table size */ 422 pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) * 423 le32_to_cpu((*gpt)->sizeof_partition_entry); 424 if (pt_size > KMALLOC_MAX_SIZE) { 425 pr_debug("GUID Partition Table is too large: %llu > %lu bytes\n", 426 (unsigned long long)pt_size, KMALLOC_MAX_SIZE); 427 goto fail; 428 } 429 430 if (!(*ptes = alloc_read_gpt_entries(state, *gpt))) 431 goto fail; 432 433 /* Check the GUID Partition Entry Array CRC */ 434 crc = efi_crc32((const unsigned char *) (*ptes), pt_size); 435 436 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { 437 pr_debug("GUID Partition Entry Array CRC check failed.\n"); 438 goto fail_ptes; 439 } 440 441 /* We're done, all's well */ 442 return 1; 443 444 fail_ptes: 445 kfree(*ptes); 446 *ptes = NULL; 447 fail: 448 kfree(*gpt); 449 *gpt = NULL; 450 return 0; 451 } 452 453 /** 454 * is_pte_valid() - tests one PTE for validity 455 * @pte:pte to check 456 * @lastlba: last lba of the disk 457 * 458 * Description: returns 1 if valid, 0 on error. 459 */ 460 static inline int 461 is_pte_valid(const gpt_entry *pte, const u64 lastlba) 462 { 463 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) || 464 le64_to_cpu(pte->starting_lba) > lastlba || 465 le64_to_cpu(pte->ending_lba) > lastlba) 466 return 0; 467 return 1; 468 } 469 470 /** 471 * compare_gpts() - Search disk for valid GPT headers and PTEs 472 * @pgpt: primary GPT header 473 * @agpt: alternate GPT header 474 * @lastlba: last LBA number 475 * 476 * Description: Returns nothing. Sanity checks pgpt and agpt fields 477 * and prints warnings on discrepancies. 478 * 479 */ 480 static void 481 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) 482 { 483 int error_found = 0; 484 if (!pgpt || !agpt) 485 return; 486 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { 487 pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n"); 488 pr_warn("GPT:%lld != %lld\n", 489 (unsigned long long)le64_to_cpu(pgpt->my_lba), 490 (unsigned long long)le64_to_cpu(agpt->alternate_lba)); 491 error_found++; 492 } 493 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { 494 pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n"); 495 pr_warn("GPT:%lld != %lld\n", 496 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 497 (unsigned long long)le64_to_cpu(agpt->my_lba)); 498 error_found++; 499 } 500 if (le64_to_cpu(pgpt->first_usable_lba) != 501 le64_to_cpu(agpt->first_usable_lba)) { 502 pr_warn("GPT:first_usable_lbas don't match.\n"); 503 pr_warn("GPT:%lld != %lld\n", 504 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba), 505 (unsigned long long)le64_to_cpu(agpt->first_usable_lba)); 506 error_found++; 507 } 508 if (le64_to_cpu(pgpt->last_usable_lba) != 509 le64_to_cpu(agpt->last_usable_lba)) { 510 pr_warn("GPT:last_usable_lbas don't match.\n"); 511 pr_warn("GPT:%lld != %lld\n", 512 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba), 513 (unsigned long long)le64_to_cpu(agpt->last_usable_lba)); 514 error_found++; 515 } 516 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { 517 pr_warn("GPT:disk_guids don't match.\n"); 518 error_found++; 519 } 520 if (le32_to_cpu(pgpt->num_partition_entries) != 521 le32_to_cpu(agpt->num_partition_entries)) { 522 pr_warn("GPT:num_partition_entries don't match: " 523 "0x%x != 0x%x\n", 524 le32_to_cpu(pgpt->num_partition_entries), 525 le32_to_cpu(agpt->num_partition_entries)); 526 error_found++; 527 } 528 if (le32_to_cpu(pgpt->sizeof_partition_entry) != 529 le32_to_cpu(agpt->sizeof_partition_entry)) { 530 pr_warn("GPT:sizeof_partition_entry values don't match: " 531 "0x%x != 0x%x\n", 532 le32_to_cpu(pgpt->sizeof_partition_entry), 533 le32_to_cpu(agpt->sizeof_partition_entry)); 534 error_found++; 535 } 536 if (le32_to_cpu(pgpt->partition_entry_array_crc32) != 537 le32_to_cpu(agpt->partition_entry_array_crc32)) { 538 pr_warn("GPT:partition_entry_array_crc32 values don't match: " 539 "0x%x != 0x%x\n", 540 le32_to_cpu(pgpt->partition_entry_array_crc32), 541 le32_to_cpu(agpt->partition_entry_array_crc32)); 542 error_found++; 543 } 544 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { 545 pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); 546 pr_warn("GPT:%lld != %lld\n", 547 (unsigned long long)le64_to_cpu(pgpt->alternate_lba), 548 (unsigned long long)lastlba); 549 error_found++; 550 } 551 552 if (le64_to_cpu(agpt->my_lba) != lastlba) { 553 pr_warn("GPT:Alternate GPT header not at the end of the disk.\n"); 554 pr_warn("GPT:%lld != %lld\n", 555 (unsigned long long)le64_to_cpu(agpt->my_lba), 556 (unsigned long long)lastlba); 557 error_found++; 558 } 559 560 if (error_found) 561 pr_warn("GPT: Use GNU Parted to correct GPT errors.\n"); 562 return; 563 } 564 565 /** 566 * find_valid_gpt() - Search disk for valid GPT headers and PTEs 567 * @state: disk parsed partitions 568 * @gpt: GPT header ptr, filled on return. 569 * @ptes: PTEs ptr, filled on return. 570 * 571 * Description: Returns 1 if valid, 0 on error. 572 * If valid, returns pointers to newly allocated GPT header and PTEs. 573 * Validity depends on PMBR being valid (or being overridden by the 574 * 'gpt' kernel command line option) and finding either the Primary 575 * GPT header and PTEs valid, or the Alternate GPT header and PTEs 576 * valid. If the Primary GPT header is not valid, the Alternate GPT header 577 * is not checked unless the 'gpt' kernel command line option is passed. 578 * This protects against devices which misreport their size, and forces 579 * the user to decide to use the Alternate GPT. 580 */ 581 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt, 582 gpt_entry **ptes) 583 { 584 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; 585 gpt_header *pgpt = NULL, *agpt = NULL; 586 gpt_entry *pptes = NULL, *aptes = NULL; 587 legacy_mbr *legacymbr; 588 struct gendisk *disk = state->disk; 589 const struct block_device_operations *fops = disk->fops; 590 sector_t total_sectors = get_capacity(state->disk); 591 u64 lastlba; 592 593 if (!ptes) 594 return 0; 595 596 lastlba = last_lba(state->disk); 597 if (!force_gpt) { 598 /* This will be added to the EFI Spec. per Intel after v1.02. */ 599 legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL); 600 if (!legacymbr) 601 goto fail; 602 603 read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr)); 604 good_pmbr = is_pmbr_valid(legacymbr, total_sectors); 605 kfree(legacymbr); 606 607 if (!good_pmbr) 608 goto fail; 609 610 pr_debug("Device has a %s MBR\n", 611 good_pmbr == GPT_MBR_PROTECTIVE ? 612 "protective" : "hybrid"); 613 } 614 615 good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA, 616 &pgpt, &pptes); 617 if (good_pgpt) 618 good_agpt = is_gpt_valid(state, 619 le64_to_cpu(pgpt->alternate_lba), 620 &agpt, &aptes); 621 if (!good_agpt && force_gpt) 622 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes); 623 624 if (!good_agpt && force_gpt && fops->alternative_gpt_sector) { 625 sector_t agpt_sector; 626 int err; 627 628 err = fops->alternative_gpt_sector(disk, &agpt_sector); 629 if (!err) 630 good_agpt = is_gpt_valid(state, agpt_sector, 631 &agpt, &aptes); 632 } 633 634 /* The obviously unsuccessful case */ 635 if (!good_pgpt && !good_agpt) 636 goto fail; 637 638 compare_gpts(pgpt, agpt, lastlba); 639 640 /* The good cases */ 641 if (good_pgpt) { 642 *gpt = pgpt; 643 *ptes = pptes; 644 kfree(agpt); 645 kfree(aptes); 646 if (!good_agpt) 647 pr_warn("Alternate GPT is invalid, using primary GPT.\n"); 648 return 1; 649 } 650 else if (good_agpt) { 651 *gpt = agpt; 652 *ptes = aptes; 653 kfree(pgpt); 654 kfree(pptes); 655 pr_warn("Primary GPT is invalid, using alternate GPT.\n"); 656 return 1; 657 } 658 659 fail: 660 kfree(pgpt); 661 kfree(agpt); 662 kfree(pptes); 663 kfree(aptes); 664 *gpt = NULL; 665 *ptes = NULL; 666 return 0; 667 } 668 669 /** 670 * utf16_le_to_7bit(): Naively converts a UTF-16LE string to 7-bit ASCII characters 671 * @in: input UTF-16LE string 672 * @size: size of the input string 673 * @out: output string ptr, should be capable to store @size+1 characters 674 * 675 * Description: Converts @size UTF16-LE symbols from @in string to 7-bit 676 * ASCII characters and stores them to @out. Adds trailing zero to @out array. 677 */ 678 static void utf16_le_to_7bit(const __le16 *in, unsigned int size, u8 *out) 679 { 680 unsigned int i = 0; 681 682 out[size] = 0; 683 684 while (i < size) { 685 u8 c = le16_to_cpu(in[i]) & 0xff; 686 687 if (c && !isprint(c)) 688 c = '!'; 689 out[i] = c; 690 i++; 691 } 692 } 693 694 /** 695 * efi_partition - scan for GPT partitions 696 * @state: disk parsed partitions 697 * 698 * Description: called from check.c, if the disk contains GPT 699 * partitions, sets up partition entries in the kernel. 700 * 701 * If the first block on the disk is a legacy MBR, 702 * it will get handled by msdos_partition(). 703 * If it's a Protective MBR, we'll handle it here. 704 * 705 * We do not create a Linux partition for GPT, but 706 * only for the actual data partitions. 707 * Returns: 708 * -1 if unable to read the partition table 709 * 0 if this isn't our partition table 710 * 1 if successful 711 * 712 */ 713 int efi_partition(struct parsed_partitions *state) 714 { 715 gpt_header *gpt = NULL; 716 gpt_entry *ptes = NULL; 717 u32 i; 718 unsigned ssz = queue_logical_block_size(state->disk->queue) / 512; 719 720 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) { 721 kfree(gpt); 722 kfree(ptes); 723 return 0; 724 } 725 726 pr_debug("GUID Partition Table is valid! Yea!\n"); 727 728 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { 729 struct partition_meta_info *info; 730 unsigned label_max; 731 u64 start = le64_to_cpu(ptes[i].starting_lba); 732 u64 size = le64_to_cpu(ptes[i].ending_lba) - 733 le64_to_cpu(ptes[i].starting_lba) + 1ULL; 734 735 if (!is_pte_valid(&ptes[i], last_lba(state->disk))) 736 continue; 737 738 put_partition(state, i+1, start * ssz, size * ssz); 739 740 /* If this is a RAID volume, tell md */ 741 if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID)) 742 state->parts[i + 1].flags = ADDPART_FLAG_RAID; 743 744 info = &state->parts[i + 1].info; 745 efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid); 746 747 /* Naively convert UTF16-LE to 7 bits. */ 748 label_max = min(ARRAY_SIZE(info->volname) - 1, 749 ARRAY_SIZE(ptes[i].partition_name)); 750 utf16_le_to_7bit(ptes[i].partition_name, label_max, info->volname); 751 state->parts[i + 1].has_info = true; 752 } 753 kfree(ptes); 754 kfree(gpt); 755 strlcat(state->pp_buf, "\n", PAGE_SIZE); 756 return 1; 757 } 758