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1da177e4 LT |
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 | ************************************************************/ | |
1da177e4 LT |
94 | #include <linux/crc32.h> |
95 | #include "check.h" | |
96 | #include "efi.h" | |
97 | ||
98 | #undef EFI_DEBUG | |
99 | #ifdef EFI_DEBUG | |
100 | #define Dprintk(x...) printk(KERN_DEBUG x) | |
101 | #else | |
102 | #define Dprintk(x...) | |
103 | #endif | |
104 | ||
105 | /* This allows a kernel command line option 'gpt' to override | |
106 | * the test for invalid PMBR. Not __initdata because reloading | |
107 | * the partition tables happens after init too. | |
108 | */ | |
109 | static int force_gpt; | |
110 | static int __init | |
111 | force_gpt_fn(char *str) | |
112 | { | |
113 | force_gpt = 1; | |
114 | return 1; | |
115 | } | |
116 | __setup("gpt", force_gpt_fn); | |
117 | ||
118 | ||
119 | /** | |
120 | * efi_crc32() - EFI version of crc32 function | |
121 | * @buf: buffer to calculate crc32 of | |
122 | * @len - length of buf | |
123 | * | |
124 | * Description: Returns EFI-style CRC32 value for @buf | |
125 | * | |
126 | * This function uses the little endian Ethernet polynomial | |
127 | * but seeds the function with ~0, and xor's with ~0 at the end. | |
128 | * Note, the EFI Specification, v1.02, has a reference to | |
129 | * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). | |
130 | */ | |
131 | static inline u32 | |
132 | efi_crc32(const void *buf, unsigned long len) | |
133 | { | |
134 | return (crc32(~0L, buf, len) ^ ~0L); | |
135 | } | |
136 | ||
137 | /** | |
138 | * last_lba(): return number of last logical block of device | |
139 | * @bdev: block device | |
140 | * | |
141 | * Description: Returns last LBA value on success, 0 on error. | |
142 | * This is stored (by sd and ide-geometry) in | |
143 | * the part[0] entry for this disk, and is the number of | |
144 | * physical sectors available on the disk. | |
145 | */ | |
146 | static u64 | |
147 | last_lba(struct block_device *bdev) | |
148 | { | |
149 | if (!bdev || !bdev->bd_inode) | |
150 | return 0; | |
151 | return (bdev->bd_inode->i_size >> 9) - 1ULL; | |
152 | } | |
153 | ||
154 | static inline int | |
4c64c30a | 155 | pmbr_part_valid(struct partition *part) |
1da177e4 LT |
156 | { |
157 | if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT && | |
158 | le32_to_cpu(part->start_sect) == 1UL) | |
159 | return 1; | |
160 | return 0; | |
161 | } | |
162 | ||
163 | /** | |
164 | * is_pmbr_valid(): test Protective MBR for validity | |
165 | * @mbr: pointer to a legacy mbr structure | |
1da177e4 LT |
166 | * |
167 | * Description: Returns 1 if PMBR is valid, 0 otherwise. | |
168 | * Validity depends on two things: | |
169 | * 1) MSDOS signature is in the last two bytes of the MBR | |
170 | * 2) One partition of type 0xEE is found | |
171 | */ | |
172 | static int | |
4c64c30a | 173 | is_pmbr_valid(legacy_mbr *mbr) |
1da177e4 LT |
174 | { |
175 | int i; | |
176 | if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE) | |
177 | return 0; | |
178 | for (i = 0; i < 4; i++) | |
4c64c30a | 179 | if (pmbr_part_valid(&mbr->partition_record[i])) |
1da177e4 LT |
180 | return 1; |
181 | return 0; | |
182 | } | |
183 | ||
184 | /** | |
185 | * read_lba(): Read bytes from disk, starting at given LBA | |
186 | * @bdev | |
187 | * @lba | |
188 | * @buffer | |
189 | * @size_t | |
190 | * | |
191 | * Description: Reads @count bytes from @bdev into @buffer. | |
192 | * Returns number of bytes read on success, 0 on error. | |
193 | */ | |
194 | static size_t | |
195 | read_lba(struct block_device *bdev, u64 lba, u8 * buffer, size_t count) | |
196 | { | |
197 | size_t totalreadcount = 0; | |
198 | ||
199 | if (!bdev || !buffer || lba > last_lba(bdev)) | |
200 | return 0; | |
201 | ||
202 | while (count) { | |
203 | int copied = 512; | |
204 | Sector sect; | |
205 | unsigned char *data = read_dev_sector(bdev, lba++, §); | |
206 | if (!data) | |
207 | break; | |
208 | if (copied > count) | |
209 | copied = count; | |
210 | memcpy(buffer, data, copied); | |
211 | put_dev_sector(sect); | |
212 | buffer += copied; | |
213 | totalreadcount +=copied; | |
214 | count -= copied; | |
215 | } | |
216 | return totalreadcount; | |
217 | } | |
218 | ||
219 | /** | |
220 | * alloc_read_gpt_entries(): reads partition entries from disk | |
221 | * @bdev | |
222 | * @gpt - GPT header | |
223 | * | |
224 | * Description: Returns ptes on success, NULL on error. | |
225 | * Allocates space for PTEs based on information found in @gpt. | |
226 | * Notes: remember to free pte when you're done! | |
227 | */ | |
228 | static gpt_entry * | |
229 | alloc_read_gpt_entries(struct block_device *bdev, gpt_header *gpt) | |
230 | { | |
231 | size_t count; | |
232 | gpt_entry *pte; | |
233 | if (!bdev || !gpt) | |
234 | return NULL; | |
235 | ||
236 | count = le32_to_cpu(gpt->num_partition_entries) * | |
237 | le32_to_cpu(gpt->sizeof_partition_entry); | |
238 | if (!count) | |
239 | return NULL; | |
f8314dc6 | 240 | pte = kzalloc(count, GFP_KERNEL); |
1da177e4 LT |
241 | if (!pte) |
242 | return NULL; | |
1da177e4 LT |
243 | |
244 | if (read_lba(bdev, le64_to_cpu(gpt->partition_entry_lba), | |
245 | (u8 *) pte, | |
246 | count) < count) { | |
247 | kfree(pte); | |
248 | pte=NULL; | |
249 | return NULL; | |
250 | } | |
251 | return pte; | |
252 | } | |
253 | ||
254 | /** | |
255 | * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk | |
256 | * @bdev | |
257 | * @lba is the Logical Block Address of the partition table | |
258 | * | |
259 | * Description: returns GPT header on success, NULL on error. Allocates | |
260 | * and fills a GPT header starting at @ from @bdev. | |
261 | * Note: remember to free gpt when finished with it. | |
262 | */ | |
263 | static gpt_header * | |
264 | alloc_read_gpt_header(struct block_device *bdev, u64 lba) | |
265 | { | |
266 | gpt_header *gpt; | |
267 | if (!bdev) | |
268 | return NULL; | |
269 | ||
f8314dc6 | 270 | gpt = kzalloc(sizeof (gpt_header), GFP_KERNEL); |
1da177e4 LT |
271 | if (!gpt) |
272 | return NULL; | |
1da177e4 LT |
273 | |
274 | if (read_lba(bdev, lba, (u8 *) gpt, | |
275 | sizeof (gpt_header)) < sizeof (gpt_header)) { | |
276 | kfree(gpt); | |
277 | gpt=NULL; | |
278 | return NULL; | |
279 | } | |
280 | ||
281 | return gpt; | |
282 | } | |
283 | ||
284 | /** | |
285 | * is_gpt_valid() - tests one GPT header and PTEs for validity | |
286 | * @bdev | |
287 | * @lba is the logical block address of the GPT header to test | |
288 | * @gpt is a GPT header ptr, filled on return. | |
289 | * @ptes is a PTEs ptr, filled on return. | |
290 | * | |
291 | * Description: returns 1 if valid, 0 on error. | |
292 | * If valid, returns pointers to newly allocated GPT header and PTEs. | |
293 | */ | |
294 | static int | |
295 | is_gpt_valid(struct block_device *bdev, u64 lba, | |
296 | gpt_header **gpt, gpt_entry **ptes) | |
297 | { | |
298 | u32 crc, origcrc; | |
299 | u64 lastlba; | |
300 | ||
301 | if (!bdev || !gpt || !ptes) | |
302 | return 0; | |
303 | if (!(*gpt = alloc_read_gpt_header(bdev, lba))) | |
304 | return 0; | |
305 | ||
306 | /* Check the GUID Partition Table signature */ | |
307 | if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { | |
308 | Dprintk("GUID Partition Table Header signature is wrong:" | |
309 | "%lld != %lld\n", | |
310 | (unsigned long long)le64_to_cpu((*gpt)->signature), | |
311 | (unsigned long long)GPT_HEADER_SIGNATURE); | |
312 | goto fail; | |
313 | } | |
314 | ||
315 | /* Check the GUID Partition Table CRC */ | |
316 | origcrc = le32_to_cpu((*gpt)->header_crc32); | |
317 | (*gpt)->header_crc32 = 0; | |
318 | crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); | |
319 | ||
320 | if (crc != origcrc) { | |
321 | Dprintk | |
322 | ("GUID Partition Table Header CRC is wrong: %x != %x\n", | |
323 | crc, origcrc); | |
324 | goto fail; | |
325 | } | |
326 | (*gpt)->header_crc32 = cpu_to_le32(origcrc); | |
327 | ||
328 | /* Check that the my_lba entry points to the LBA that contains | |
329 | * the GUID Partition Table */ | |
330 | if (le64_to_cpu((*gpt)->my_lba) != lba) { | |
331 | Dprintk("GPT my_lba incorrect: %lld != %lld\n", | |
332 | (unsigned long long)le64_to_cpu((*gpt)->my_lba), | |
333 | (unsigned long long)lba); | |
334 | goto fail; | |
335 | } | |
336 | ||
337 | /* Check the first_usable_lba and last_usable_lba are | |
338 | * within the disk. | |
339 | */ | |
340 | lastlba = last_lba(bdev); | |
341 | if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) { | |
342 | Dprintk("GPT: first_usable_lba incorrect: %lld > %lld\n", | |
343 | (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba), | |
344 | (unsigned long long)lastlba); | |
345 | goto fail; | |
346 | } | |
347 | if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) { | |
348 | Dprintk("GPT: last_usable_lba incorrect: %lld > %lld\n", | |
349 | (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), | |
350 | (unsigned long long)lastlba); | |
351 | goto fail; | |
352 | } | |
353 | ||
354 | if (!(*ptes = alloc_read_gpt_entries(bdev, *gpt))) | |
355 | goto fail; | |
356 | ||
357 | /* Check the GUID Partition Entry Array CRC */ | |
358 | crc = efi_crc32((const unsigned char *) (*ptes), | |
359 | le32_to_cpu((*gpt)->num_partition_entries) * | |
360 | le32_to_cpu((*gpt)->sizeof_partition_entry)); | |
361 | ||
362 | if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { | |
363 | Dprintk("GUID Partitition Entry Array CRC check failed.\n"); | |
364 | goto fail_ptes; | |
365 | } | |
366 | ||
367 | /* We're done, all's well */ | |
368 | return 1; | |
369 | ||
370 | fail_ptes: | |
371 | kfree(*ptes); | |
372 | *ptes = NULL; | |
373 | fail: | |
374 | kfree(*gpt); | |
375 | *gpt = NULL; | |
376 | return 0; | |
377 | } | |
378 | ||
379 | /** | |
380 | * is_pte_valid() - tests one PTE for validity | |
381 | * @pte is the pte to check | |
382 | * @lastlba is last lba of the disk | |
383 | * | |
384 | * Description: returns 1 if valid, 0 on error. | |
385 | */ | |
386 | static inline int | |
387 | is_pte_valid(const gpt_entry *pte, const u64 lastlba) | |
388 | { | |
389 | if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) || | |
390 | le64_to_cpu(pte->starting_lba) > lastlba || | |
391 | le64_to_cpu(pte->ending_lba) > lastlba) | |
392 | return 0; | |
393 | return 1; | |
394 | } | |
395 | ||
396 | /** | |
397 | * compare_gpts() - Search disk for valid GPT headers and PTEs | |
398 | * @pgpt is the primary GPT header | |
399 | * @agpt is the alternate GPT header | |
400 | * @lastlba is the last LBA number | |
401 | * Description: Returns nothing. Sanity checks pgpt and agpt fields | |
402 | * and prints warnings on discrepancies. | |
403 | * | |
404 | */ | |
405 | static void | |
406 | compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) | |
407 | { | |
408 | int error_found = 0; | |
409 | if (!pgpt || !agpt) | |
410 | return; | |
411 | if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { | |
412 | printk(KERN_WARNING | |
413 | "GPT:Primary header LBA != Alt. header alternate_lba\n"); | |
414 | printk(KERN_WARNING "GPT:%lld != %lld\n", | |
415 | (unsigned long long)le64_to_cpu(pgpt->my_lba), | |
416 | (unsigned long long)le64_to_cpu(agpt->alternate_lba)); | |
417 | error_found++; | |
418 | } | |
419 | if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { | |
420 | printk(KERN_WARNING | |
421 | "GPT:Primary header alternate_lba != Alt. header my_lba\n"); | |
422 | printk(KERN_WARNING "GPT:%lld != %lld\n", | |
423 | (unsigned long long)le64_to_cpu(pgpt->alternate_lba), | |
424 | (unsigned long long)le64_to_cpu(agpt->my_lba)); | |
425 | error_found++; | |
426 | } | |
427 | if (le64_to_cpu(pgpt->first_usable_lba) != | |
428 | le64_to_cpu(agpt->first_usable_lba)) { | |
429 | printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n"); | |
430 | printk(KERN_WARNING "GPT:%lld != %lld\n", | |
431 | (unsigned long long)le64_to_cpu(pgpt->first_usable_lba), | |
432 | (unsigned long long)le64_to_cpu(agpt->first_usable_lba)); | |
433 | error_found++; | |
434 | } | |
435 | if (le64_to_cpu(pgpt->last_usable_lba) != | |
436 | le64_to_cpu(agpt->last_usable_lba)) { | |
437 | printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n"); | |
438 | printk(KERN_WARNING "GPT:%lld != %lld\n", | |
439 | (unsigned long long)le64_to_cpu(pgpt->last_usable_lba), | |
440 | (unsigned long long)le64_to_cpu(agpt->last_usable_lba)); | |
441 | error_found++; | |
442 | } | |
443 | if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { | |
444 | printk(KERN_WARNING "GPT:disk_guids don't match.\n"); | |
445 | error_found++; | |
446 | } | |
447 | if (le32_to_cpu(pgpt->num_partition_entries) != | |
448 | le32_to_cpu(agpt->num_partition_entries)) { | |
449 | printk(KERN_WARNING "GPT:num_partition_entries don't match: " | |
450 | "0x%x != 0x%x\n", | |
451 | le32_to_cpu(pgpt->num_partition_entries), | |
452 | le32_to_cpu(agpt->num_partition_entries)); | |
453 | error_found++; | |
454 | } | |
455 | if (le32_to_cpu(pgpt->sizeof_partition_entry) != | |
456 | le32_to_cpu(agpt->sizeof_partition_entry)) { | |
457 | printk(KERN_WARNING | |
458 | "GPT:sizeof_partition_entry values don't match: " | |
459 | "0x%x != 0x%x\n", | |
460 | le32_to_cpu(pgpt->sizeof_partition_entry), | |
461 | le32_to_cpu(agpt->sizeof_partition_entry)); | |
462 | error_found++; | |
463 | } | |
464 | if (le32_to_cpu(pgpt->partition_entry_array_crc32) != | |
465 | le32_to_cpu(agpt->partition_entry_array_crc32)) { | |
466 | printk(KERN_WARNING | |
467 | "GPT:partition_entry_array_crc32 values don't match: " | |
468 | "0x%x != 0x%x\n", | |
469 | le32_to_cpu(pgpt->partition_entry_array_crc32), | |
470 | le32_to_cpu(agpt->partition_entry_array_crc32)); | |
471 | error_found++; | |
472 | } | |
473 | if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { | |
474 | printk(KERN_WARNING | |
475 | "GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); | |
476 | printk(KERN_WARNING "GPT:%lld != %lld\n", | |
477 | (unsigned long long)le64_to_cpu(pgpt->alternate_lba), | |
478 | (unsigned long long)lastlba); | |
479 | error_found++; | |
480 | } | |
481 | ||
482 | if (le64_to_cpu(agpt->my_lba) != lastlba) { | |
483 | printk(KERN_WARNING | |
484 | "GPT:Alternate GPT header not at the end of the disk.\n"); | |
485 | printk(KERN_WARNING "GPT:%lld != %lld\n", | |
486 | (unsigned long long)le64_to_cpu(agpt->my_lba), | |
487 | (unsigned long long)lastlba); | |
488 | error_found++; | |
489 | } | |
490 | ||
491 | if (error_found) | |
492 | printk(KERN_WARNING | |
493 | "GPT: Use GNU Parted to correct GPT errors.\n"); | |
494 | return; | |
495 | } | |
496 | ||
497 | /** | |
498 | * find_valid_gpt() - Search disk for valid GPT headers and PTEs | |
499 | * @bdev | |
500 | * @gpt is a GPT header ptr, filled on return. | |
501 | * @ptes is a PTEs ptr, filled on return. | |
502 | * Description: Returns 1 if valid, 0 on error. | |
503 | * If valid, returns pointers to newly allocated GPT header and PTEs. | |
504 | * Validity depends on PMBR being valid (or being overridden by the | |
505 | * 'gpt' kernel command line option) and finding either the Primary | |
506 | * GPT header and PTEs valid, or the Alternate GPT header and PTEs | |
507 | * valid. If the Primary GPT header is not valid, the Alternate GPT header | |
508 | * is not checked unless the 'gpt' kernel command line option is passed. | |
509 | * This protects against devices which misreport their size, and forces | |
510 | * the user to decide to use the Alternate GPT. | |
511 | */ | |
512 | static int | |
513 | find_valid_gpt(struct block_device *bdev, gpt_header **gpt, gpt_entry **ptes) | |
514 | { | |
515 | int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; | |
516 | gpt_header *pgpt = NULL, *agpt = NULL; | |
517 | gpt_entry *pptes = NULL, *aptes = NULL; | |
4c64c30a | 518 | legacy_mbr *legacymbr; |
1da177e4 LT |
519 | u64 lastlba; |
520 | if (!bdev || !gpt || !ptes) | |
521 | return 0; | |
522 | ||
523 | lastlba = last_lba(bdev); | |
524 | if (!force_gpt) { | |
525 | /* This will be added to the EFI Spec. per Intel after v1.02. */ | |
f8314dc6 | 526 | legacymbr = kzalloc(sizeof (*legacymbr), GFP_KERNEL); |
1da177e4 | 527 | if (legacymbr) { |
1da177e4 LT |
528 | read_lba(bdev, 0, (u8 *) legacymbr, |
529 | sizeof (*legacymbr)); | |
4c64c30a | 530 | good_pmbr = is_pmbr_valid(legacymbr); |
1da177e4 | 531 | kfree(legacymbr); |
1da177e4 LT |
532 | } |
533 | if (!good_pmbr) | |
534 | goto fail; | |
535 | } | |
536 | ||
537 | good_pgpt = is_gpt_valid(bdev, GPT_PRIMARY_PARTITION_TABLE_LBA, | |
538 | &pgpt, &pptes); | |
539 | if (good_pgpt) | |
540 | good_agpt = is_gpt_valid(bdev, | |
541 | le64_to_cpu(pgpt->alternate_lba), | |
542 | &agpt, &aptes); | |
543 | if (!good_agpt && force_gpt) | |
544 | good_agpt = is_gpt_valid(bdev, lastlba, | |
545 | &agpt, &aptes); | |
546 | ||
547 | /* The obviously unsuccessful case */ | |
548 | if (!good_pgpt && !good_agpt) | |
549 | goto fail; | |
550 | ||
551 | compare_gpts(pgpt, agpt, lastlba); | |
552 | ||
553 | /* The good cases */ | |
554 | if (good_pgpt) { | |
555 | *gpt = pgpt; | |
556 | *ptes = pptes; | |
557 | kfree(agpt); | |
558 | kfree(aptes); | |
559 | if (!good_agpt) { | |
560 | printk(KERN_WARNING | |
561 | "Alternate GPT is invalid, " | |
562 | "using primary GPT.\n"); | |
563 | } | |
564 | return 1; | |
565 | } | |
566 | else if (good_agpt) { | |
567 | *gpt = agpt; | |
568 | *ptes = aptes; | |
569 | kfree(pgpt); | |
570 | kfree(pptes); | |
571 | printk(KERN_WARNING | |
572 | "Primary GPT is invalid, using alternate GPT.\n"); | |
573 | return 1; | |
574 | } | |
575 | ||
576 | fail: | |
577 | kfree(pgpt); | |
578 | kfree(agpt); | |
579 | kfree(pptes); | |
580 | kfree(aptes); | |
581 | *gpt = NULL; | |
582 | *ptes = NULL; | |
583 | return 0; | |
584 | } | |
585 | ||
586 | /** | |
587 | * efi_partition(struct parsed_partitions *state, struct block_device *bdev) | |
588 | * @state | |
589 | * @bdev | |
590 | * | |
591 | * Description: called from check.c, if the disk contains GPT | |
592 | * partitions, sets up partition entries in the kernel. | |
593 | * | |
594 | * If the first block on the disk is a legacy MBR, | |
595 | * it will get handled by msdos_partition(). | |
596 | * If it's a Protective MBR, we'll handle it here. | |
597 | * | |
598 | * We do not create a Linux partition for GPT, but | |
599 | * only for the actual data partitions. | |
600 | * Returns: | |
601 | * -1 if unable to read the partition table | |
602 | * 0 if this isn't our partition table | |
603 | * 1 if successful | |
604 | * | |
605 | */ | |
606 | int | |
607 | efi_partition(struct parsed_partitions *state, struct block_device *bdev) | |
608 | { | |
609 | gpt_header *gpt = NULL; | |
610 | gpt_entry *ptes = NULL; | |
611 | u32 i; | |
612 | ||
613 | if (!find_valid_gpt(bdev, &gpt, &ptes) || !gpt || !ptes) { | |
614 | kfree(gpt); | |
615 | kfree(ptes); | |
616 | return 0; | |
617 | } | |
618 | ||
619 | Dprintk("GUID Partition Table is valid! Yea!\n"); | |
620 | ||
621 | for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { | |
622 | if (!is_pte_valid(&ptes[i], last_lba(bdev))) | |
623 | continue; | |
624 | ||
625 | put_partition(state, i+1, le64_to_cpu(ptes[i].starting_lba), | |
626 | (le64_to_cpu(ptes[i].ending_lba) - | |
627 | le64_to_cpu(ptes[i].starting_lba) + | |
628 | 1ULL)); | |
629 | ||
630 | /* If this is a RAID volume, tell md */ | |
631 | if (!efi_guidcmp(ptes[i].partition_type_guid, | |
632 | PARTITION_LINUX_RAID_GUID)) | |
633 | state->parts[i+1].flags = 1; | |
634 | } | |
635 | kfree(ptes); | |
636 | kfree(gpt); | |
637 | printk("\n"); | |
638 | return 1; | |
639 | } |