efi.c 22 KB

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  1. /************************************************************
  2. * EFI GUID Partition Table handling
  3. *
  4. * http://www.uefi.org/specs/
  5. * http://www.intel.com/technology/efi/
  6. *
  7. * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com>
  8. * Copyright 2000,2001,2002,2004 Dell Inc.
  9. *
  10. * This program is free software; you can redistribute it and/or modify
  11. * it under the terms of the GNU General Public License as published by
  12. * the Free Software Foundation; either version 2 of the License, or
  13. * (at your option) any later version.
  14. *
  15. * This program is distributed in the hope that it will be useful,
  16. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18. * GNU General Public License for more details.
  19. *
  20. * You should have received a copy of the GNU General Public License
  21. * along with this program; if not, write to the Free Software
  22. * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23. *
  24. *
  25. * TODO:
  26. *
  27. * Changelog:
  28. * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com>
  29. * - test for valid PMBR and valid PGPT before ever reading
  30. * AGPT, allow override with 'gpt' kernel command line option.
  31. * - check for first/last_usable_lba outside of size of disk
  32. *
  33. * Tue Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com>
  34. * - Ported to 2.5.7-pre1 and 2.5.7-dj2
  35. * - Applied patch to avoid fault in alternate header handling
  36. * - cleaned up find_valid_gpt
  37. * - On-disk structure and copy in memory is *always* LE now -
  38. * swab fields as needed
  39. * - remove print_gpt_header()
  40. * - only use first max_p partition entries, to keep the kernel minor number
  41. * and partition numbers tied.
  42. *
  43. * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com>
  44. * - Removed __PRIPTR_PREFIX - not being used
  45. *
  46. * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com>
  47. * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied
  48. *
  49. * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com>
  50. * - Added compare_gpts().
  51. * - moved le_efi_guid_to_cpus() back into this file. GPT is the only
  52. * thing that keeps EFI GUIDs on disk.
  53. * - Changed gpt structure names and members to be simpler and more Linux-like.
  54. *
  55. * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com>
  56. * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck
  57. *
  58. * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com>
  59. * - Changed function comments to DocBook style per Andreas Dilger suggestion.
  60. *
  61. * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com>
  62. * - Change read_lba() to use the page cache per Al Viro's work.
  63. * - print u64s properly on all architectures
  64. * - fixed debug_printk(), now Dprintk()
  65. *
  66. * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com>
  67. * - Style cleanups
  68. * - made most functions static
  69. * - Endianness addition
  70. * - remove test for second alternate header, as it's not per spec,
  71. * and is unnecessary. There's now a method to read/write the last
  72. * sector of an odd-sized disk from user space. No tools have ever
  73. * been released which used this code, so it's effectively dead.
  74. * - Per Asit Mallick of Intel, added a test for a valid PMBR.
  75. * - Added kernel command line option 'gpt' to override valid PMBR test.
  76. *
  77. * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com>
  78. * - added devfs volume UUID support (/dev/volumes/uuids) for
  79. * mounting file systems by the partition GUID.
  80. *
  81. * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com>
  82. * - Moved crc32() to linux/lib, added efi_crc32().
  83. *
  84. * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com>
  85. * - Replaced Intel's CRC32 function with an equivalent
  86. * non-license-restricted version.
  87. *
  88. * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com>
  89. * - Fixed the last_lba() call to return the proper last block
  90. *
  91. * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com>
  92. * - Thanks to Andries Brouwer for his debugging assistance.
  93. * - Code works, detects all the partitions.
  94. *
  95. ************************************************************/
  96. #include <linux/crc32.h>
  97. #include <linux/ctype.h>
  98. #include <linux/math64.h>
  99. #include <linux/slab.h>
  100. #include "check.h"
  101. #include "efi.h"
  102. /* This allows a kernel command line option 'gpt' to override
  103. * the test for invalid PMBR. Not __initdata because reloading
  104. * the partition tables happens after init too.
  105. */
  106. static int force_gpt;
  107. static int __init
  108. force_gpt_fn(char *str)
  109. {
  110. force_gpt = 1;
  111. return 1;
  112. }
  113. __setup("gpt", force_gpt_fn);
  114. /**
  115. * efi_crc32() - EFI version of crc32 function
  116. * @buf: buffer to calculate crc32 of
  117. * @len - length of buf
  118. *
  119. * Description: Returns EFI-style CRC32 value for @buf
  120. *
  121. * This function uses the little endian Ethernet polynomial
  122. * but seeds the function with ~0, and xor's with ~0 at the end.
  123. * Note, the EFI Specification, v1.02, has a reference to
  124. * Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
  125. */
  126. static inline u32
  127. efi_crc32(const void *buf, unsigned long len)
  128. {
  129. return (crc32(~0L, buf, len) ^ ~0L);
  130. }
  131. /**
  132. * last_lba(): return number of last logical block of device
  133. * @bdev: block device
  134. *
  135. * Description: Returns last LBA value on success, 0 on error.
  136. * This is stored (by sd and ide-geometry) in
  137. * the part[0] entry for this disk, and is the number of
  138. * physical sectors available on the disk.
  139. */
  140. static u64 last_lba(struct block_device *bdev)
  141. {
  142. if (!bdev || !bdev->bd_inode)
  143. return 0;
  144. return div_u64(bdev->bd_inode->i_size,
  145. bdev_logical_block_size(bdev)) - 1ULL;
  146. }
  147. static inline int pmbr_part_valid(gpt_mbr_record *part)
  148. {
  149. if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT)
  150. goto invalid;
  151. /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */
  152. if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA)
  153. goto invalid;
  154. return GPT_MBR_PROTECTIVE;
  155. invalid:
  156. return 0;
  157. }
  158. /**
  159. * is_pmbr_valid(): test Protective MBR for validity
  160. * @mbr: pointer to a legacy mbr structure
  161. *
  162. * Description: Checks for a valid protective or hybrid
  163. * master boot record (MBR). The validity of a pMBR depends
  164. * on all of the following properties:
  165. * 1) MSDOS signature is in the last two bytes of the MBR
  166. * 2) One partition of type 0xEE is found
  167. *
  168. * In addition, a hybrid MBR will have up to three additional
  169. * primary partitions, which point to the same space that's
  170. * marked out by up to three GPT partitions.
  171. *
  172. * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or
  173. * GPT_MBR_HYBRID depending on the device layout.
  174. */
  175. static int is_pmbr_valid(legacy_mbr *mbr)
  176. {
  177. int i, ret = 0; /* invalid by default */
  178. if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
  179. goto done;
  180. for (i = 0; i < 4; i++) {
  181. ret = pmbr_part_valid(&mbr->partition_record[i]);
  182. if (ret == GPT_MBR_PROTECTIVE) {
  183. /*
  184. * Ok, we at least know that there's a protective MBR,
  185. * now check if there are other partition types for
  186. * hybrid MBR.
  187. */
  188. goto check_hybrid;
  189. }
  190. }
  191. if (ret != GPT_MBR_PROTECTIVE)
  192. goto done;
  193. check_hybrid:
  194. for (i = 0; i < 4; i++)
  195. if ((mbr->partition_record[i].os_type !=
  196. EFI_PMBR_OSTYPE_EFI_GPT) &&
  197. (mbr->partition_record[i].os_type != 0x00))
  198. ret = GPT_MBR_HYBRID;
  199. done:
  200. return ret;
  201. }
  202. /**
  203. * read_lba(): Read bytes from disk, starting at given LBA
  204. * @state
  205. * @lba
  206. * @buffer
  207. * @size_t
  208. *
  209. * Description: Reads @count bytes from @state->bdev into @buffer.
  210. * Returns number of bytes read on success, 0 on error.
  211. */
  212. static size_t read_lba(struct parsed_partitions *state,
  213. u64 lba, u8 *buffer, size_t count)
  214. {
  215. size_t totalreadcount = 0;
  216. struct block_device *bdev = state->bdev;
  217. sector_t n = lba * (bdev_logical_block_size(bdev) / 512);
  218. if (!buffer || lba > last_lba(bdev))
  219. return 0;
  220. while (count) {
  221. int copied = 512;
  222. Sector sect;
  223. unsigned char *data = read_part_sector(state, n++, &sect);
  224. if (!data)
  225. break;
  226. if (copied > count)
  227. copied = count;
  228. memcpy(buffer, data, copied);
  229. put_dev_sector(sect);
  230. buffer += copied;
  231. totalreadcount +=copied;
  232. count -= copied;
  233. }
  234. return totalreadcount;
  235. }
  236. /**
  237. * alloc_read_gpt_entries(): reads partition entries from disk
  238. * @state
  239. * @gpt - GPT header
  240. *
  241. * Description: Returns ptes on success, NULL on error.
  242. * Allocates space for PTEs based on information found in @gpt.
  243. * Notes: remember to free pte when you're done!
  244. */
  245. static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state,
  246. gpt_header *gpt)
  247. {
  248. size_t count;
  249. gpt_entry *pte;
  250. if (!gpt)
  251. return NULL;
  252. count = le32_to_cpu(gpt->num_partition_entries) *
  253. le32_to_cpu(gpt->sizeof_partition_entry);
  254. if (!count)
  255. return NULL;
  256. pte = kmalloc(count, GFP_KERNEL);
  257. if (!pte)
  258. return NULL;
  259. if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
  260. (u8 *) pte,
  261. count) < count) {
  262. kfree(pte);
  263. pte=NULL;
  264. return NULL;
  265. }
  266. return pte;
  267. }
  268. /**
  269. * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
  270. * @state
  271. * @lba is the Logical Block Address of the partition table
  272. *
  273. * Description: returns GPT header on success, NULL on error. Allocates
  274. * and fills a GPT header starting at @ from @state->bdev.
  275. * Note: remember to free gpt when finished with it.
  276. */
  277. static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
  278. u64 lba)
  279. {
  280. gpt_header *gpt;
  281. unsigned ssz = bdev_logical_block_size(state->bdev);
  282. gpt = kmalloc(ssz, GFP_KERNEL);
  283. if (!gpt)
  284. return NULL;
  285. if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
  286. kfree(gpt);
  287. gpt=NULL;
  288. return NULL;
  289. }
  290. return gpt;
  291. }
  292. /**
  293. * is_gpt_valid() - tests one GPT header and PTEs for validity
  294. * @state
  295. * @lba is the logical block address of the GPT header to test
  296. * @gpt is a GPT header ptr, filled on return.
  297. * @ptes is a PTEs ptr, filled on return.
  298. *
  299. * Description: returns 1 if valid, 0 on error.
  300. * If valid, returns pointers to newly allocated GPT header and PTEs.
  301. */
  302. static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
  303. gpt_header **gpt, gpt_entry **ptes)
  304. {
  305. u32 crc, origcrc;
  306. u64 lastlba;
  307. if (!ptes)
  308. return 0;
  309. if (!(*gpt = alloc_read_gpt_header(state, lba)))
  310. return 0;
  311. /* Check the GUID Partition Table signature */
  312. if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
  313. pr_debug("GUID Partition Table Header signature is wrong:"
  314. "%lld != %lld\n",
  315. (unsigned long long)le64_to_cpu((*gpt)->signature),
  316. (unsigned long long)GPT_HEADER_SIGNATURE);
  317. goto fail;
  318. }
  319. /* Check the GUID Partition Table header size is too big */
  320. if (le32_to_cpu((*gpt)->header_size) >
  321. bdev_logical_block_size(state->bdev)) {
  322. pr_debug("GUID Partition Table Header size is too large: %u > %u\n",
  323. le32_to_cpu((*gpt)->header_size),
  324. bdev_logical_block_size(state->bdev));
  325. goto fail;
  326. }
  327. /* Check the GUID Partition Table header size is too small */
  328. if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) {
  329. pr_debug("GUID Partition Table Header size is too small: %u < %zu\n",
  330. le32_to_cpu((*gpt)->header_size),
  331. sizeof(gpt_header));
  332. goto fail;
  333. }
  334. /* Check the GUID Partition Table CRC */
  335. origcrc = le32_to_cpu((*gpt)->header_crc32);
  336. (*gpt)->header_crc32 = 0;
  337. crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
  338. if (crc != origcrc) {
  339. pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
  340. crc, origcrc);
  341. goto fail;
  342. }
  343. (*gpt)->header_crc32 = cpu_to_le32(origcrc);
  344. /* Check that the my_lba entry points to the LBA that contains
  345. * the GUID Partition Table */
  346. if (le64_to_cpu((*gpt)->my_lba) != lba) {
  347. pr_debug("GPT my_lba incorrect: %lld != %lld\n",
  348. (unsigned long long)le64_to_cpu((*gpt)->my_lba),
  349. (unsigned long long)lba);
  350. goto fail;
  351. }
  352. /* Check the first_usable_lba and last_usable_lba are
  353. * within the disk.
  354. */
  355. lastlba = last_lba(state->bdev);
  356. if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
  357. pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
  358. (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
  359. (unsigned long long)lastlba);
  360. goto fail;
  361. }
  362. if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
  363. pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
  364. (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
  365. (unsigned long long)lastlba);
  366. goto fail;
  367. }
  368. /* Check that sizeof_partition_entry has the correct value */
  369. if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
  370. pr_debug("GUID Partitition Entry Size check failed.\n");
  371. goto fail;
  372. }
  373. if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
  374. goto fail;
  375. /* Check the GUID Partition Entry Array CRC */
  376. crc = efi_crc32((const unsigned char *) (*ptes),
  377. le32_to_cpu((*gpt)->num_partition_entries) *
  378. le32_to_cpu((*gpt)->sizeof_partition_entry));
  379. if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
  380. pr_debug("GUID Partitition Entry Array CRC check failed.\n");
  381. goto fail_ptes;
  382. }
  383. /* We're done, all's well */
  384. return 1;
  385. fail_ptes:
  386. kfree(*ptes);
  387. *ptes = NULL;
  388. fail:
  389. kfree(*gpt);
  390. *gpt = NULL;
  391. return 0;
  392. }
  393. /**
  394. * is_pte_valid() - tests one PTE for validity
  395. * @pte is the pte to check
  396. * @lastlba is last lba of the disk
  397. *
  398. * Description: returns 1 if valid, 0 on error.
  399. */
  400. static inline int
  401. is_pte_valid(const gpt_entry *pte, const u64 lastlba)
  402. {
  403. if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
  404. le64_to_cpu(pte->starting_lba) > lastlba ||
  405. le64_to_cpu(pte->ending_lba) > lastlba)
  406. return 0;
  407. return 1;
  408. }
  409. /**
  410. * compare_gpts() - Search disk for valid GPT headers and PTEs
  411. * @pgpt is the primary GPT header
  412. * @agpt is the alternate GPT header
  413. * @lastlba is the last LBA number
  414. * Description: Returns nothing. Sanity checks pgpt and agpt fields
  415. * and prints warnings on discrepancies.
  416. *
  417. */
  418. static void
  419. compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
  420. {
  421. int error_found = 0;
  422. if (!pgpt || !agpt)
  423. return;
  424. if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
  425. printk(KERN_WARNING
  426. "GPT:Primary header LBA != Alt. header alternate_lba\n");
  427. printk(KERN_WARNING "GPT:%lld != %lld\n",
  428. (unsigned long long)le64_to_cpu(pgpt->my_lba),
  429. (unsigned long long)le64_to_cpu(agpt->alternate_lba));
  430. error_found++;
  431. }
  432. if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
  433. printk(KERN_WARNING
  434. "GPT:Primary header alternate_lba != Alt. header my_lba\n");
  435. printk(KERN_WARNING "GPT:%lld != %lld\n",
  436. (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
  437. (unsigned long long)le64_to_cpu(agpt->my_lba));
  438. error_found++;
  439. }
  440. if (le64_to_cpu(pgpt->first_usable_lba) !=
  441. le64_to_cpu(agpt->first_usable_lba)) {
  442. printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n");
  443. printk(KERN_WARNING "GPT:%lld != %lld\n",
  444. (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
  445. (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
  446. error_found++;
  447. }
  448. if (le64_to_cpu(pgpt->last_usable_lba) !=
  449. le64_to_cpu(agpt->last_usable_lba)) {
  450. printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n");
  451. printk(KERN_WARNING "GPT:%lld != %lld\n",
  452. (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
  453. (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
  454. error_found++;
  455. }
  456. if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
  457. printk(KERN_WARNING "GPT:disk_guids don't match.\n");
  458. error_found++;
  459. }
  460. if (le32_to_cpu(pgpt->num_partition_entries) !=
  461. le32_to_cpu(agpt->num_partition_entries)) {
  462. printk(KERN_WARNING "GPT:num_partition_entries don't match: "
  463. "0x%x != 0x%x\n",
  464. le32_to_cpu(pgpt->num_partition_entries),
  465. le32_to_cpu(agpt->num_partition_entries));
  466. error_found++;
  467. }
  468. if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
  469. le32_to_cpu(agpt->sizeof_partition_entry)) {
  470. printk(KERN_WARNING
  471. "GPT:sizeof_partition_entry values don't match: "
  472. "0x%x != 0x%x\n",
  473. le32_to_cpu(pgpt->sizeof_partition_entry),
  474. le32_to_cpu(agpt->sizeof_partition_entry));
  475. error_found++;
  476. }
  477. if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
  478. le32_to_cpu(agpt->partition_entry_array_crc32)) {
  479. printk(KERN_WARNING
  480. "GPT:partition_entry_array_crc32 values don't match: "
  481. "0x%x != 0x%x\n",
  482. le32_to_cpu(pgpt->partition_entry_array_crc32),
  483. le32_to_cpu(agpt->partition_entry_array_crc32));
  484. error_found++;
  485. }
  486. if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
  487. printk(KERN_WARNING
  488. "GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
  489. printk(KERN_WARNING "GPT:%lld != %lld\n",
  490. (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
  491. (unsigned long long)lastlba);
  492. error_found++;
  493. }
  494. if (le64_to_cpu(agpt->my_lba) != lastlba) {
  495. printk(KERN_WARNING
  496. "GPT:Alternate GPT header not at the end of the disk.\n");
  497. printk(KERN_WARNING "GPT:%lld != %lld\n",
  498. (unsigned long long)le64_to_cpu(agpt->my_lba),
  499. (unsigned long long)lastlba);
  500. error_found++;
  501. }
  502. if (error_found)
  503. printk(KERN_WARNING
  504. "GPT: Use GNU Parted to correct GPT errors.\n");
  505. return;
  506. }
  507. /**
  508. * find_valid_gpt() - Search disk for valid GPT headers and PTEs
  509. * @state
  510. * @gpt is a GPT header ptr, filled on return.
  511. * @ptes is a PTEs ptr, filled on return.
  512. * Description: Returns 1 if valid, 0 on error.
  513. * If valid, returns pointers to newly allocated GPT header and PTEs.
  514. * Validity depends on PMBR being valid (or being overridden by the
  515. * 'gpt' kernel command line option) and finding either the Primary
  516. * GPT header and PTEs valid, or the Alternate GPT header and PTEs
  517. * valid. If the Primary GPT header is not valid, the Alternate GPT header
  518. * is not checked unless the 'gpt' kernel command line option is passed.
  519. * This protects against devices which misreport their size, and forces
  520. * the user to decide to use the Alternate GPT.
  521. */
  522. static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
  523. gpt_entry **ptes)
  524. {
  525. int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
  526. gpt_header *pgpt = NULL, *agpt = NULL;
  527. gpt_entry *pptes = NULL, *aptes = NULL;
  528. legacy_mbr *legacymbr;
  529. u64 lastlba;
  530. if (!ptes)
  531. return 0;
  532. lastlba = last_lba(state->bdev);
  533. if (!force_gpt) {
  534. /* This will be added to the EFI Spec. per Intel after v1.02. */
  535. legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL);
  536. if (!legacymbr)
  537. goto fail;
  538. read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr));
  539. good_pmbr = is_pmbr_valid(legacymbr);
  540. kfree(legacymbr);
  541. if (!good_pmbr)
  542. goto fail;
  543. pr_debug("Device has a %s MBR\n",
  544. good_pmbr == GPT_MBR_PROTECTIVE ?
  545. "protective" : "hybrid");
  546. }
  547. good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
  548. &pgpt, &pptes);
  549. if (good_pgpt)
  550. good_agpt = is_gpt_valid(state,
  551. le64_to_cpu(pgpt->alternate_lba),
  552. &agpt, &aptes);
  553. if (!good_agpt && force_gpt)
  554. good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
  555. /* The obviously unsuccessful case */
  556. if (!good_pgpt && !good_agpt)
  557. goto fail;
  558. compare_gpts(pgpt, agpt, lastlba);
  559. /* The good cases */
  560. if (good_pgpt) {
  561. *gpt = pgpt;
  562. *ptes = pptes;
  563. kfree(agpt);
  564. kfree(aptes);
  565. if (!good_agpt) {
  566. printk(KERN_WARNING
  567. "Alternate GPT is invalid, "
  568. "using primary GPT.\n");
  569. }
  570. return 1;
  571. }
  572. else if (good_agpt) {
  573. *gpt = agpt;
  574. *ptes = aptes;
  575. kfree(pgpt);
  576. kfree(pptes);
  577. printk(KERN_WARNING
  578. "Primary GPT is invalid, using alternate GPT.\n");
  579. return 1;
  580. }
  581. fail:
  582. kfree(pgpt);
  583. kfree(agpt);
  584. kfree(pptes);
  585. kfree(aptes);
  586. *gpt = NULL;
  587. *ptes = NULL;
  588. return 0;
  589. }
  590. /**
  591. * efi_partition(struct parsed_partitions *state)
  592. * @state
  593. *
  594. * Description: called from check.c, if the disk contains GPT
  595. * partitions, sets up partition entries in the kernel.
  596. *
  597. * If the first block on the disk is a legacy MBR,
  598. * it will get handled by msdos_partition().
  599. * If it's a Protective MBR, we'll handle it here.
  600. *
  601. * We do not create a Linux partition for GPT, but
  602. * only for the actual data partitions.
  603. * Returns:
  604. * -1 if unable to read the partition table
  605. * 0 if this isn't our partition table
  606. * 1 if successful
  607. *
  608. */
  609. int efi_partition(struct parsed_partitions *state)
  610. {
  611. gpt_header *gpt = NULL;
  612. gpt_entry *ptes = NULL;
  613. u32 i;
  614. unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
  615. if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
  616. kfree(gpt);
  617. kfree(ptes);
  618. return 0;
  619. }
  620. pr_debug("GUID Partition Table is valid! Yea!\n");
  621. for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
  622. struct partition_meta_info *info;
  623. unsigned label_count = 0;
  624. unsigned label_max;
  625. u64 start = le64_to_cpu(ptes[i].starting_lba);
  626. u64 size = le64_to_cpu(ptes[i].ending_lba) -
  627. le64_to_cpu(ptes[i].starting_lba) + 1ULL;
  628. if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
  629. continue;
  630. put_partition(state, i+1, start * ssz, size * ssz);
  631. /* If this is a RAID volume, tell md */
  632. if (!efi_guidcmp(ptes[i].partition_type_guid,
  633. PARTITION_LINUX_RAID_GUID))
  634. state->parts[i + 1].flags = ADDPART_FLAG_RAID;
  635. info = &state->parts[i + 1].info;
  636. efi_guid_unparse(&ptes[i].unique_partition_guid, info->uuid);
  637. /* Naively convert UTF16-LE to 7 bits. */
  638. label_max = min(sizeof(info->volname) - 1,
  639. sizeof(ptes[i].partition_name));
  640. info->volname[label_max] = 0;
  641. while (label_count < label_max) {
  642. u8 c = ptes[i].partition_name[label_count] & 0xff;
  643. if (c && !isprint(c))
  644. c = '!';
  645. info->volname[label_count] = c;
  646. label_count++;
  647. }
  648. state->parts[i + 1].has_info = true;
  649. }
  650. kfree(ptes);
  651. kfree(gpt);
  652. strlcat(state->pp_buf, "\n", PAGE_SIZE);
  653. return 1;
  654. }