diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/partitions/efi.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/partitions/efi.c')
-rw-r--r-- | fs/partitions/efi.c | 645 |
1 files changed, 645 insertions, 0 deletions
diff --git a/fs/partitions/efi.c b/fs/partitions/efi.c new file mode 100644 index 00000000000..0f5b017aeba --- /dev/null +++ b/fs/partitions/efi.c | |||
@@ -0,0 +1,645 @@ | |||
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/config.h> | ||
95 | #include <linux/crc32.h> | ||
96 | #include "check.h" | ||
97 | #include "efi.h" | ||
98 | |||
99 | #undef EFI_DEBUG | ||
100 | #ifdef EFI_DEBUG | ||
101 | #define Dprintk(x...) printk(KERN_DEBUG x) | ||
102 | #else | ||
103 | #define Dprintk(x...) | ||
104 | #endif | ||
105 | |||
106 | /* This allows a kernel command line option 'gpt' to override | ||
107 | * the test for invalid PMBR. Not __initdata because reloading | ||
108 | * the partition tables happens after init too. | ||
109 | */ | ||
110 | static int force_gpt; | ||
111 | static int __init | ||
112 | force_gpt_fn(char *str) | ||
113 | { | ||
114 | force_gpt = 1; | ||
115 | return 1; | ||
116 | } | ||
117 | __setup("gpt", force_gpt_fn); | ||
118 | |||
119 | |||
120 | /** | ||
121 | * efi_crc32() - EFI version of crc32 function | ||
122 | * @buf: buffer to calculate crc32 of | ||
123 | * @len - length of buf | ||
124 | * | ||
125 | * Description: Returns EFI-style CRC32 value for @buf | ||
126 | * | ||
127 | * This function uses the little endian Ethernet polynomial | ||
128 | * but seeds the function with ~0, and xor's with ~0 at the end. | ||
129 | * Note, the EFI Specification, v1.02, has a reference to | ||
130 | * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). | ||
131 | */ | ||
132 | static inline u32 | ||
133 | efi_crc32(const void *buf, unsigned long len) | ||
134 | { | ||
135 | return (crc32(~0L, buf, len) ^ ~0L); | ||
136 | } | ||
137 | |||
138 | /** | ||
139 | * last_lba(): return number of last logical block of device | ||
140 | * @bdev: block device | ||
141 | * | ||
142 | * Description: Returns last LBA value on success, 0 on error. | ||
143 | * This is stored (by sd and ide-geometry) in | ||
144 | * the part[0] entry for this disk, and is the number of | ||
145 | * physical sectors available on the disk. | ||
146 | */ | ||
147 | static u64 | ||
148 | last_lba(struct block_device *bdev) | ||
149 | { | ||
150 | if (!bdev || !bdev->bd_inode) | ||
151 | return 0; | ||
152 | return (bdev->bd_inode->i_size >> 9) - 1ULL; | ||
153 | } | ||
154 | |||
155 | static inline int | ||
156 | pmbr_part_valid(struct partition *part, u64 lastlba) | ||
157 | { | ||
158 | if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT && | ||
159 | le32_to_cpu(part->start_sect) == 1UL) | ||
160 | return 1; | ||
161 | return 0; | ||
162 | } | ||
163 | |||
164 | /** | ||
165 | * is_pmbr_valid(): test Protective MBR for validity | ||
166 | * @mbr: pointer to a legacy mbr structure | ||
167 | * @lastlba: last_lba for the whole device | ||
168 | * | ||
169 | * Description: Returns 1 if PMBR is valid, 0 otherwise. | ||
170 | * Validity depends on two things: | ||
171 | * 1) MSDOS signature is in the last two bytes of the MBR | ||
172 | * 2) One partition of type 0xEE is found | ||
173 | */ | ||
174 | static int | ||
175 | is_pmbr_valid(legacy_mbr *mbr, u64 lastlba) | ||
176 | { | ||
177 | int i; | ||
178 | if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE) | ||
179 | return 0; | ||
180 | for (i = 0; i < 4; i++) | ||
181 | if (pmbr_part_valid(&mbr->partition_record[i], lastlba)) | ||
182 | return 1; | ||
183 | return 0; | ||
184 | } | ||
185 | |||
186 | /** | ||
187 | * read_lba(): Read bytes from disk, starting at given LBA | ||
188 | * @bdev | ||
189 | * @lba | ||
190 | * @buffer | ||
191 | * @size_t | ||
192 | * | ||
193 | * Description: Reads @count bytes from @bdev into @buffer. | ||
194 | * Returns number of bytes read on success, 0 on error. | ||
195 | */ | ||
196 | static size_t | ||
197 | read_lba(struct block_device *bdev, u64 lba, u8 * buffer, size_t count) | ||
198 | { | ||
199 | size_t totalreadcount = 0; | ||
200 | |||
201 | if (!bdev || !buffer || lba > last_lba(bdev)) | ||
202 | return 0; | ||
203 | |||
204 | while (count) { | ||
205 | int copied = 512; | ||
206 | Sector sect; | ||
207 | unsigned char *data = read_dev_sector(bdev, lba++, §); | ||
208 | if (!data) | ||
209 | break; | ||
210 | if (copied > count) | ||
211 | copied = count; | ||
212 | memcpy(buffer, data, copied); | ||
213 | put_dev_sector(sect); | ||
214 | buffer += copied; | ||
215 | totalreadcount +=copied; | ||
216 | count -= copied; | ||
217 | } | ||
218 | return totalreadcount; | ||
219 | } | ||
220 | |||
221 | /** | ||
222 | * alloc_read_gpt_entries(): reads partition entries from disk | ||
223 | * @bdev | ||
224 | * @gpt - GPT header | ||
225 | * | ||
226 | * Description: Returns ptes on success, NULL on error. | ||
227 | * Allocates space for PTEs based on information found in @gpt. | ||
228 | * Notes: remember to free pte when you're done! | ||
229 | */ | ||
230 | static gpt_entry * | ||
231 | alloc_read_gpt_entries(struct block_device *bdev, gpt_header *gpt) | ||
232 | { | ||
233 | size_t count; | ||
234 | gpt_entry *pte; | ||
235 | if (!bdev || !gpt) | ||
236 | return NULL; | ||
237 | |||
238 | count = le32_to_cpu(gpt->num_partition_entries) * | ||
239 | le32_to_cpu(gpt->sizeof_partition_entry); | ||
240 | if (!count) | ||
241 | return NULL; | ||
242 | pte = kmalloc(count, GFP_KERNEL); | ||
243 | if (!pte) | ||
244 | return NULL; | ||
245 | memset(pte, 0, count); | ||
246 | |||
247 | if (read_lba(bdev, le64_to_cpu(gpt->partition_entry_lba), | ||
248 | (u8 *) pte, | ||
249 | count) < count) { | ||
250 | kfree(pte); | ||
251 | pte=NULL; | ||
252 | return NULL; | ||
253 | } | ||
254 | return pte; | ||
255 | } | ||
256 | |||
257 | /** | ||
258 | * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk | ||
259 | * @bdev | ||
260 | * @lba is the Logical Block Address of the partition table | ||
261 | * | ||
262 | * Description: returns GPT header on success, NULL on error. Allocates | ||
263 | * and fills a GPT header starting at @ from @bdev. | ||
264 | * Note: remember to free gpt when finished with it. | ||
265 | */ | ||
266 | static gpt_header * | ||
267 | alloc_read_gpt_header(struct block_device *bdev, u64 lba) | ||
268 | { | ||
269 | gpt_header *gpt; | ||
270 | if (!bdev) | ||
271 | return NULL; | ||
272 | |||
273 | gpt = kmalloc(sizeof (gpt_header), GFP_KERNEL); | ||
274 | if (!gpt) | ||
275 | return NULL; | ||
276 | memset(gpt, 0, sizeof (gpt_header)); | ||
277 | |||
278 | if (read_lba(bdev, lba, (u8 *) gpt, | ||
279 | sizeof (gpt_header)) < sizeof (gpt_header)) { | ||
280 | kfree(gpt); | ||
281 | gpt=NULL; | ||
282 | return NULL; | ||
283 | } | ||
284 | |||
285 | return gpt; | ||
286 | } | ||
287 | |||
288 | /** | ||
289 | * is_gpt_valid() - tests one GPT header and PTEs for validity | ||
290 | * @bdev | ||
291 | * @lba is the logical block address of the GPT header to test | ||
292 | * @gpt is a GPT header ptr, filled on return. | ||
293 | * @ptes is a PTEs ptr, filled on return. | ||
294 | * | ||
295 | * Description: returns 1 if valid, 0 on error. | ||
296 | * If valid, returns pointers to newly allocated GPT header and PTEs. | ||
297 | */ | ||
298 | static int | ||
299 | is_gpt_valid(struct block_device *bdev, u64 lba, | ||
300 | gpt_header **gpt, gpt_entry **ptes) | ||
301 | { | ||
302 | u32 crc, origcrc; | ||
303 | u64 lastlba; | ||
304 | |||
305 | if (!bdev || !gpt || !ptes) | ||
306 | return 0; | ||
307 | if (!(*gpt = alloc_read_gpt_header(bdev, lba))) | ||
308 | return 0; | ||
309 | |||
310 | /* Check the GUID Partition Table signature */ | ||
311 | if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { | ||
312 | Dprintk("GUID Partition Table Header signature is wrong:" | ||
313 | "%lld != %lld\n", | ||
314 | (unsigned long long)le64_to_cpu((*gpt)->signature), | ||
315 | (unsigned long long)GPT_HEADER_SIGNATURE); | ||
316 | goto fail; | ||
317 | } | ||
318 | |||
319 | /* Check the GUID Partition Table CRC */ | ||
320 | origcrc = le32_to_cpu((*gpt)->header_crc32); | ||
321 | (*gpt)->header_crc32 = 0; | ||
322 | crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); | ||
323 | |||
324 | if (crc != origcrc) { | ||
325 | Dprintk | ||
326 | ("GUID Partition Table Header CRC is wrong: %x != %x\n", | ||
327 | crc, origcrc); | ||
328 | goto fail; | ||
329 | } | ||
330 | (*gpt)->header_crc32 = cpu_to_le32(origcrc); | ||
331 | |||
332 | /* Check that the my_lba entry points to the LBA that contains | ||
333 | * the GUID Partition Table */ | ||
334 | if (le64_to_cpu((*gpt)->my_lba) != lba) { | ||
335 | Dprintk("GPT my_lba incorrect: %lld != %lld\n", | ||
336 | (unsigned long long)le64_to_cpu((*gpt)->my_lba), | ||
337 | (unsigned long long)lba); | ||
338 | goto fail; | ||
339 | } | ||
340 | |||
341 | /* Check the first_usable_lba and last_usable_lba are | ||
342 | * within the disk. | ||
343 | */ | ||
344 | lastlba = last_lba(bdev); | ||
345 | if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) { | ||
346 | Dprintk("GPT: first_usable_lba incorrect: %lld > %lld\n", | ||
347 | (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba), | ||
348 | (unsigned long long)lastlba); | ||
349 | goto fail; | ||
350 | } | ||
351 | if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) { | ||
352 | Dprintk("GPT: last_usable_lba incorrect: %lld > %lld\n", | ||
353 | (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), | ||
354 | (unsigned long long)lastlba); | ||
355 | goto fail; | ||
356 | } | ||
357 | |||
358 | if (!(*ptes = alloc_read_gpt_entries(bdev, *gpt))) | ||
359 | goto fail; | ||
360 | |||
361 | /* Check the GUID Partition Entry Array CRC */ | ||
362 | crc = efi_crc32((const unsigned char *) (*ptes), | ||
363 | le32_to_cpu((*gpt)->num_partition_entries) * | ||
364 | le32_to_cpu((*gpt)->sizeof_partition_entry)); | ||
365 | |||
366 | if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { | ||
367 | Dprintk("GUID Partitition Entry Array CRC check failed.\n"); | ||
368 | goto fail_ptes; | ||
369 | } | ||
370 | |||
371 | /* We're done, all's well */ | ||
372 | return 1; | ||
373 | |||
374 | fail_ptes: | ||
375 | kfree(*ptes); | ||
376 | *ptes = NULL; | ||
377 | fail: | ||
378 | kfree(*gpt); | ||
379 | *gpt = NULL; | ||
380 | return 0; | ||
381 | } | ||
382 | |||
383 | /** | ||
384 | * is_pte_valid() - tests one PTE for validity | ||
385 | * @pte is the pte to check | ||
386 | * @lastlba is last lba of the disk | ||
387 | * | ||
388 | * Description: returns 1 if valid, 0 on error. | ||
389 | */ | ||
390 | static inline int | ||
391 | is_pte_valid(const gpt_entry *pte, const u64 lastlba) | ||
392 | { | ||
393 | if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) || | ||
394 | le64_to_cpu(pte->starting_lba) > lastlba || | ||
395 | le64_to_cpu(pte->ending_lba) > lastlba) | ||
396 | return 0; | ||
397 | return 1; | ||
398 | } | ||
399 | |||
400 | /** | ||
401 | * compare_gpts() - Search disk for valid GPT headers and PTEs | ||
402 | * @pgpt is the primary GPT header | ||
403 | * @agpt is the alternate GPT header | ||
404 | * @lastlba is the last LBA number | ||
405 | * Description: Returns nothing. Sanity checks pgpt and agpt fields | ||
406 | * and prints warnings on discrepancies. | ||
407 | * | ||
408 | */ | ||
409 | static void | ||
410 | compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) | ||
411 | { | ||
412 | int error_found = 0; | ||
413 | if (!pgpt || !agpt) | ||
414 | return; | ||
415 | if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { | ||
416 | printk(KERN_WARNING | ||
417 | "GPT:Primary header LBA != Alt. header alternate_lba\n"); | ||
418 | printk(KERN_WARNING "GPT:%lld != %lld\n", | ||
419 | (unsigned long long)le64_to_cpu(pgpt->my_lba), | ||
420 | (unsigned long long)le64_to_cpu(agpt->alternate_lba)); | ||
421 | error_found++; | ||
422 | } | ||
423 | if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { | ||
424 | printk(KERN_WARNING | ||
425 | "GPT:Primary header alternate_lba != Alt. header my_lba\n"); | ||
426 | printk(KERN_WARNING "GPT:%lld != %lld\n", | ||
427 | (unsigned long long)le64_to_cpu(pgpt->alternate_lba), | ||
428 | (unsigned long long)le64_to_cpu(agpt->my_lba)); | ||
429 | error_found++; | ||
430 | } | ||
431 | if (le64_to_cpu(pgpt->first_usable_lba) != | ||
432 | le64_to_cpu(agpt->first_usable_lba)) { | ||
433 | printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n"); | ||
434 | printk(KERN_WARNING "GPT:%lld != %lld\n", | ||
435 | (unsigned long long)le64_to_cpu(pgpt->first_usable_lba), | ||
436 | (unsigned long long)le64_to_cpu(agpt->first_usable_lba)); | ||
437 | error_found++; | ||
438 | } | ||
439 | if (le64_to_cpu(pgpt->last_usable_lba) != | ||
440 | le64_to_cpu(agpt->last_usable_lba)) { | ||
441 | printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n"); | ||
442 | printk(KERN_WARNING "GPT:%lld != %lld\n", | ||
443 | (unsigned long long)le64_to_cpu(pgpt->last_usable_lba), | ||
444 | (unsigned long long)le64_to_cpu(agpt->last_usable_lba)); | ||
445 | error_found++; | ||
446 | } | ||
447 | if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { | ||
448 | printk(KERN_WARNING "GPT:disk_guids don't match.\n"); | ||
449 | error_found++; | ||
450 | } | ||
451 | if (le32_to_cpu(pgpt->num_partition_entries) != | ||
452 | le32_to_cpu(agpt->num_partition_entries)) { | ||
453 | printk(KERN_WARNING "GPT:num_partition_entries don't match: " | ||
454 | "0x%x != 0x%x\n", | ||
455 | le32_to_cpu(pgpt->num_partition_entries), | ||
456 | le32_to_cpu(agpt->num_partition_entries)); | ||
457 | error_found++; | ||
458 | } | ||
459 | if (le32_to_cpu(pgpt->sizeof_partition_entry) != | ||
460 | le32_to_cpu(agpt->sizeof_partition_entry)) { | ||
461 | printk(KERN_WARNING | ||
462 | "GPT:sizeof_partition_entry values don't match: " | ||
463 | "0x%x != 0x%x\n", | ||
464 | le32_to_cpu(pgpt->sizeof_partition_entry), | ||
465 | le32_to_cpu(agpt->sizeof_partition_entry)); | ||
466 | error_found++; | ||
467 | } | ||
468 | if (le32_to_cpu(pgpt->partition_entry_array_crc32) != | ||
469 | le32_to_cpu(agpt->partition_entry_array_crc32)) { | ||
470 | printk(KERN_WARNING | ||
471 | "GPT:partition_entry_array_crc32 values don't match: " | ||
472 | "0x%x != 0x%x\n", | ||
473 | le32_to_cpu(pgpt->partition_entry_array_crc32), | ||
474 | le32_to_cpu(agpt->partition_entry_array_crc32)); | ||
475 | error_found++; | ||
476 | } | ||
477 | if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { | ||
478 | printk(KERN_WARNING | ||
479 | "GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); | ||
480 | printk(KERN_WARNING "GPT:%lld != %lld\n", | ||
481 | (unsigned long long)le64_to_cpu(pgpt->alternate_lba), | ||
482 | (unsigned long long)lastlba); | ||
483 | error_found++; | ||
484 | } | ||
485 | |||
486 | if (le64_to_cpu(agpt->my_lba) != lastlba) { | ||
487 | printk(KERN_WARNING | ||
488 | "GPT:Alternate GPT header not at the end of the disk.\n"); | ||
489 | printk(KERN_WARNING "GPT:%lld != %lld\n", | ||
490 | (unsigned long long)le64_to_cpu(agpt->my_lba), | ||
491 | (unsigned long long)lastlba); | ||
492 | error_found++; | ||
493 | } | ||
494 | |||
495 | if (error_found) | ||
496 | printk(KERN_WARNING | ||
497 | "GPT: Use GNU Parted to correct GPT errors.\n"); | ||
498 | return; | ||
499 | } | ||
500 | |||
501 | /** | ||
502 | * find_valid_gpt() - Search disk for valid GPT headers and PTEs | ||
503 | * @bdev | ||
504 | * @gpt is a GPT header ptr, filled on return. | ||
505 | * @ptes is a PTEs ptr, filled on return. | ||
506 | * Description: Returns 1 if valid, 0 on error. | ||
507 | * If valid, returns pointers to newly allocated GPT header and PTEs. | ||
508 | * Validity depends on PMBR being valid (or being overridden by the | ||
509 | * 'gpt' kernel command line option) and finding either the Primary | ||
510 | * GPT header and PTEs valid, or the Alternate GPT header and PTEs | ||
511 | * valid. If the Primary GPT header is not valid, the Alternate GPT header | ||
512 | * is not checked unless the 'gpt' kernel command line option is passed. | ||
513 | * This protects against devices which misreport their size, and forces | ||
514 | * the user to decide to use the Alternate GPT. | ||
515 | */ | ||
516 | static int | ||
517 | find_valid_gpt(struct block_device *bdev, gpt_header **gpt, gpt_entry **ptes) | ||
518 | { | ||
519 | int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; | ||
520 | gpt_header *pgpt = NULL, *agpt = NULL; | ||
521 | gpt_entry *pptes = NULL, *aptes = NULL; | ||
522 | legacy_mbr *legacymbr = NULL; | ||
523 | u64 lastlba; | ||
524 | if (!bdev || !gpt || !ptes) | ||
525 | return 0; | ||
526 | |||
527 | lastlba = last_lba(bdev); | ||
528 | if (!force_gpt) { | ||
529 | /* This will be added to the EFI Spec. per Intel after v1.02. */ | ||
530 | legacymbr = kmalloc(sizeof (*legacymbr), GFP_KERNEL); | ||
531 | if (legacymbr) { | ||
532 | memset(legacymbr, 0, sizeof (*legacymbr)); | ||
533 | read_lba(bdev, 0, (u8 *) legacymbr, | ||
534 | sizeof (*legacymbr)); | ||
535 | good_pmbr = is_pmbr_valid(legacymbr, lastlba); | ||
536 | kfree(legacymbr); | ||
537 | legacymbr=NULL; | ||
538 | } | ||
539 | if (!good_pmbr) | ||
540 | goto fail; | ||
541 | } | ||
542 | |||
543 | good_pgpt = is_gpt_valid(bdev, GPT_PRIMARY_PARTITION_TABLE_LBA, | ||
544 | &pgpt, &pptes); | ||
545 | if (good_pgpt) | ||
546 | good_agpt = is_gpt_valid(bdev, | ||
547 | le64_to_cpu(pgpt->alternate_lba), | ||
548 | &agpt, &aptes); | ||
549 | if (!good_agpt && force_gpt) | ||
550 | good_agpt = is_gpt_valid(bdev, lastlba, | ||
551 | &agpt, &aptes); | ||
552 | |||
553 | /* The obviously unsuccessful case */ | ||
554 | if (!good_pgpt && !good_agpt) | ||
555 | goto fail; | ||
556 | |||
557 | compare_gpts(pgpt, agpt, lastlba); | ||
558 | |||
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 | |||
582 | fail: | ||
583 | kfree(pgpt); | ||
584 | kfree(agpt); | ||
585 | kfree(pptes); | ||
586 | kfree(aptes); | ||
587 | *gpt = NULL; | ||
588 | *ptes = NULL; | ||
589 | return 0; | ||
590 | } | ||
591 | |||
592 | /** | ||
593 | * efi_partition(struct parsed_partitions *state, struct block_device *bdev) | ||
594 | * @state | ||
595 | * @bdev | ||
596 | * | ||
597 | * Description: called from check.c, if the disk contains GPT | ||
598 | * partitions, sets up partition entries in the kernel. | ||
599 | * | ||
600 | * If the first block on the disk is a legacy MBR, | ||
601 | * it will get handled by msdos_partition(). | ||
602 | * If it's a Protective MBR, we'll handle it here. | ||
603 | * | ||
604 | * We do not create a Linux partition for GPT, but | ||
605 | * only for the actual data partitions. | ||
606 | * Returns: | ||
607 | * -1 if unable to read the partition table | ||
608 | * 0 if this isn't our partition table | ||
609 | * 1 if successful | ||
610 | * | ||
611 | */ | ||
612 | int | ||
613 | efi_partition(struct parsed_partitions *state, struct block_device *bdev) | ||
614 | { | ||
615 | gpt_header *gpt = NULL; | ||
616 | gpt_entry *ptes = NULL; | ||
617 | u32 i; | ||
618 | |||
619 | if (!find_valid_gpt(bdev, &gpt, &ptes) || !gpt || !ptes) { | ||
620 | kfree(gpt); | ||
621 | kfree(ptes); | ||
622 | return 0; | ||
623 | } | ||
624 | |||
625 | Dprintk("GUID Partition Table is valid! Yea!\n"); | ||
626 | |||
627 | for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { | ||
628 | if (!is_pte_valid(&ptes[i], last_lba(bdev))) | ||
629 | continue; | ||
630 | |||
631 | put_partition(state, i+1, le64_to_cpu(ptes[i].starting_lba), | ||
632 | (le64_to_cpu(ptes[i].ending_lba) - | ||
633 | le64_to_cpu(ptes[i].starting_lba) + | ||
634 | 1ULL)); | ||
635 | |||
636 | /* If this is a RAID volume, tell md */ | ||
637 | if (!efi_guidcmp(ptes[i].partition_type_guid, | ||
638 | PARTITION_LINUX_RAID_GUID)) | ||
639 | state->parts[i+1].flags = 1; | ||
640 | } | ||
641 | kfree(ptes); | ||
642 | kfree(gpt); | ||
643 | printk("\n"); | ||
644 | return 1; | ||
645 | } | ||