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