efi.c 19 KB

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