1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /************************************************************
3 * EFI GUID Partition Table handling
4 *
5 * http://www.uefi.org/specs/
6 * http://www.intel.com/technology/efi/
7 *
8 * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com>
9 * Copyright 2000,2001,2002,2004 Dell Inc.
10 *
11 * TODO:
12 *
13 * Changelog:
14 * Mon August 5th, 2013 Davidlohr Bueso <davidlohr@hp.com>
15 * - detect hybrid MBRs, tighter pMBR checking & cleanups.
16 *
17 * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com>
18 * - test for valid PMBR and valid PGPT before ever reading
19 * AGPT, allow override with 'gpt' kernel command line option.
20 * - check for first/last_usable_lba outside of size of disk
21 *
22 * Tue Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com>
23 * - Ported to 2.5.7-pre1 and 2.5.7-dj2
24 * - Applied patch to avoid fault in alternate header handling
25 * - cleaned up find_valid_gpt
26 * - On-disk structure and copy in memory is *always* LE now -
27 * swab fields as needed
28 * - remove print_gpt_header()
29 * - only use first max_p partition entries, to keep the kernel minor number
30 * and partition numbers tied.
31 *
32 * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com>
33 * - Removed __PRIPTR_PREFIX - not being used
34 *
35 * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com>
36 * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied
37 *
38 * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com>
39 * - Added compare_gpts().
40 * - moved le_efi_guid_to_cpus() back into this file. GPT is the only
41 * thing that keeps EFI GUIDs on disk.
42 * - Changed gpt structure names and members to be simpler and more Linux-like.
43 *
44 * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com>
45 * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck
46 *
47 * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com>
48 * - Changed function comments to DocBook style per Andreas Dilger suggestion.
49 *
50 * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com>
51 * - Change read_lba() to use the page cache per Al Viro's work.
52 * - print u64s properly on all architectures
53 * - fixed debug_printk(), now Dprintk()
54 *
55 * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com>
56 * - Style cleanups
57 * - made most functions static
58 * - Endianness addition
59 * - remove test for second alternate header, as it's not per spec,
60 * and is unnecessary. There's now a method to read/write the last
61 * sector of an odd-sized disk from user space. No tools have ever
62 * been released which used this code, so it's effectively dead.
63 * - Per Asit Mallick of Intel, added a test for a valid PMBR.
64 * - Added kernel command line option 'gpt' to override valid PMBR test.
65 *
66 * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com>
67 * - added devfs volume UUID support (/dev/volumes/uuids) for
68 * mounting file systems by the partition GUID.
69 *
70 * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com>
71 * - Moved crc32() to linux/lib, added efi_crc32().
72 *
73 * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com>
74 * - Replaced Intel's CRC32 function with an equivalent
75 * non-license-restricted version.
76 *
77 * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com>
78 * - Fixed the last_lba() call to return the proper last block
79 *
80 * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com>
81 * - Thanks to Andries Brouwer for his debugging assistance.
82 * - Code works, detects all the partitions.
83 *
84 ************************************************************/
85 #include <linux/kernel.h>
86 #include <linux/crc32.h>
87 #include <linux/ctype.h>
88 #include <linux/math64.h>
89 #include <linux/slab.h>
90 #include "check.h"
91 #include "efi.h"
92
93 /* This allows a kernel command line option 'gpt' to override
94 * the test for invalid PMBR. Not __initdata because reloading
95 * the partition tables happens after init too.
96 */
97 static int force_gpt;
98 static int __init
99 force_gpt_fn(char *str)
100 {
101 force_gpt = 1;
102 return 1;
103 }
104 __setup("gpt", force_gpt_fn);
105
106
107 /**
108 * efi_crc32() - EFI version of crc32 function
109 * @buf: buffer to calculate crc32 of
110 * @len: length of buf
111 *
112 * Description: Returns EFI-style CRC32 value for @buf
113 *
114 * This function uses the little endian Ethernet polynomial
115 * but seeds the function with ~0, and xor's with ~0 at the end.
116 * Note, the EFI Specification, v1.02, has a reference to
117 * Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
118 */
119 static inline u32
120 efi_crc32(const void *buf, unsigned long len)
121 {
122 return (crc32(~0L, buf, len) ^ ~0L);
123 }
124
125 /**
126 * last_lba(): return number of last logical block of device
127 * @bdev: block device
128 *
129 * Description: Returns last LBA value on success, 0 on error.
130 * This is stored (by sd and ide-geometry) in
131 * the part[0] entry for this disk, and is the number of
132 * physical sectors available on the disk.
133 */
134 static u64 last_lba(struct block_device *bdev)
135 {
136 if (!bdev || !bdev->bd_inode)
137 return 0;
138 return div_u64(bdev->bd_inode->i_size,
139 bdev_logical_block_size(bdev)) - 1ULL;
140 }
141
142 static inline int pmbr_part_valid(gpt_mbr_record *part)
143 {
144 if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT)
145 goto invalid;
146
147 /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */
148 if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA)
149 goto invalid;
150
151 return GPT_MBR_PROTECTIVE;
152 invalid:
153 return 0;
154 }
155
156 /**
157 * is_pmbr_valid(): test Protective MBR for validity
158 * @mbr: pointer to a legacy mbr structure
159 * @total_sectors: amount of sectors in the device
160 *
161 * Description: Checks for a valid protective or hybrid
162 * master boot record (MBR). The validity of a pMBR depends
163 * on all of the following properties:
164 * 1) MSDOS signature is in the last two bytes of the MBR
165 * 2) One partition of type 0xEE is found
166 *
167 * In addition, a hybrid MBR will have up to three additional
168 * primary partitions, which point to the same space that's
169 * marked out by up to three GPT partitions.
170 *
171 * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or
172 * GPT_MBR_HYBRID depending on the device layout.
173 */
174 static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors)
175 {
176 uint32_t sz = 0;
177 int i, part = 0, ret = 0; /* invalid by default */
178
179 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
180 goto done;
181
182 for (i = 0; i < 4; i++) {
183 ret = pmbr_part_valid(&mbr->partition_record[i]);
184 if (ret == GPT_MBR_PROTECTIVE) {
185 part = i;
186 /*
187 * Ok, we at least know that there's a protective MBR,
188 * now check if there are other partition types for
189 * hybrid MBR.
190 */
191 goto check_hybrid;
192 }
193 }
194
195 if (ret != GPT_MBR_PROTECTIVE)
196 goto done;
197 check_hybrid:
198 for (i = 0; i < 4; i++)
199 if ((mbr->partition_record[i].os_type !=
200 EFI_PMBR_OSTYPE_EFI_GPT) &&
201 (mbr->partition_record[i].os_type != 0x00))
202 ret = GPT_MBR_HYBRID;
203
204 /*
205 * Protective MBRs take up the lesser of the whole disk
206 * or 2 TiB (32bit LBA), ignoring the rest of the disk.
207 * Some partitioning programs, nonetheless, choose to set
208 * the size to the maximum 32-bit limitation, disregarding
209 * the disk size.
210 *
211 * Hybrid MBRs do not necessarily comply with this.
212 *
213 * Consider a bad value here to be a warning to support dd'ing
214 * an image from a smaller disk to a larger disk.
215 */
216 if (ret == GPT_MBR_PROTECTIVE) {
217 sz = le32_to_cpu(mbr->partition_record[part].size_in_lba);
218 if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF)
219 pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n",
220 sz, min_t(uint32_t,
221 total_sectors - 1, 0xFFFFFFFF));
222 }
223 done:
224 return ret;
225 }
226
227 /**
228 * read_lba(): Read bytes from disk, starting at given LBA
229 * @state: disk parsed partitions
230 * @lba: the Logical Block Address of the partition table
231 * @buffer: destination buffer
232 * @count: bytes to read
233 *
234 * Description: Reads @count bytes from @state->bdev into @buffer.
235 * Returns number of bytes read on success, 0 on error.
236 */
237 static size_t read_lba(struct parsed_partitions *state,
238 u64 lba, u8 *buffer, size_t count)
239 {
240 size_t totalreadcount = 0;
241 struct block_device *bdev = state->bdev;
242 sector_t n = lba * (bdev_logical_block_size(bdev) / 512);
243
244 if (!buffer || lba > last_lba(bdev))
245 return 0;
246
247 while (count) {
248 int copied = 512;
249 Sector sect;
250 unsigned char *data = read_part_sector(state, n++, §);
251 if (!data)
252 break;
253 if (copied > count)
254 copied = count;
255 memcpy(buffer, data, copied);
256 put_dev_sector(sect);
257 buffer += copied;
258 totalreadcount +=copied;
259 count -= copied;
260 }
261 return totalreadcount;
262 }
263
264 /**
265 * alloc_read_gpt_entries(): reads partition entries from disk
266 * @state: disk parsed partitions
267 * @gpt: GPT header
268 *
269 * Description: Returns ptes on success, NULL on error.
270 * Allocates space for PTEs based on information found in @gpt.
271 * Notes: remember to free pte when you're done!
272 */
273 static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state,
274 gpt_header *gpt)
275 {
276 size_t count;
277 gpt_entry *pte;
278
279 if (!gpt)
280 return NULL;
281
282 count = (size_t)le32_to_cpu(gpt->num_partition_entries) *
283 le32_to_cpu(gpt->sizeof_partition_entry);
284 if (!count)
285 return NULL;
286 pte = kmalloc(count, GFP_KERNEL);
287 if (!pte)
288 return NULL;
289
290 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
291 (u8 *) pte, count) < count) {
292 kfree(pte);
293 pte=NULL;
294 return NULL;
295 }
296 return pte;
297 }
298
299 /**
300 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
301 * @state: disk parsed partitions
302 * @lba: the Logical Block Address of the partition table
303 *
304 * Description: returns GPT header on success, NULL on error. Allocates
305 * and fills a GPT header starting at @ from @state->bdev.
306 * Note: remember to free gpt when finished with it.
307 */
308 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
309 u64 lba)
310 {
311 gpt_header *gpt;
312 unsigned ssz = bdev_logical_block_size(state->bdev);
313
314 gpt = kmalloc(ssz, GFP_KERNEL);
315 if (!gpt)
316 return NULL;
317
318 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
319 kfree(gpt);
320 gpt=NULL;
321 return NULL;
322 }
323
324 return gpt;
325 }
326
327 /**
328 * is_gpt_valid() - tests one GPT header and PTEs for validity
329 * @state: disk parsed partitions
330 * @lba: logical block address of the GPT header to test
331 * @gpt: GPT header ptr, filled on return.
332 * @ptes: PTEs ptr, filled on return.
333 *
334 * Description: returns 1 if valid, 0 on error.
335 * If valid, returns pointers to newly allocated GPT header and PTEs.
336 */
337 static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
338 gpt_header **gpt, gpt_entry **ptes)
339 {
340 u32 crc, origcrc;
341 u64 lastlba, pt_size;
342
343 if (!ptes)
344 return 0;
345 if (!(*gpt = alloc_read_gpt_header(state, lba)))
346 return 0;
347
348 /* Check the GUID Partition Table signature */
349 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
350 pr_debug("GUID Partition Table Header signature is wrong:"
351 "%lld != %lld\n",
352 (unsigned long long)le64_to_cpu((*gpt)->signature),
353 (unsigned long long)GPT_HEADER_SIGNATURE);
354 goto fail;
355 }
356
357 /* Check the GUID Partition Table header size is too big */
358 if (le32_to_cpu((*gpt)->header_size) >
359 bdev_logical_block_size(state->bdev)) {
360 pr_debug("GUID Partition Table Header size is too large: %u > %u\n",
361 le32_to_cpu((*gpt)->header_size),
362 bdev_logical_block_size(state->bdev));
363 goto fail;
364 }
365
366 /* Check the GUID Partition Table header size is too small */
367 if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) {
368 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n",
369 le32_to_cpu((*gpt)->header_size),
370 sizeof(gpt_header));
371 goto fail;
372 }
373
374 /* Check the GUID Partition Table CRC */
375 origcrc = le32_to_cpu((*gpt)->header_crc32);
376 (*gpt)->header_crc32 = 0;
377 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
378
379 if (crc != origcrc) {
380 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
381 crc, origcrc);
382 goto fail;
383 }
384 (*gpt)->header_crc32 = cpu_to_le32(origcrc);
385
386 /* Check that the my_lba entry points to the LBA that contains
387 * the GUID Partition Table */
388 if (le64_to_cpu((*gpt)->my_lba) != lba) {
389 pr_debug("GPT my_lba incorrect: %lld != %lld\n",
390 (unsigned long long)le64_to_cpu((*gpt)->my_lba),
391 (unsigned long long)lba);
392 goto fail;
393 }
394
395 /* Check the first_usable_lba and last_usable_lba are
396 * within the disk.
397 */
398 lastlba = last_lba(state->bdev);
399 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
400 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
401 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
402 (unsigned long long)lastlba);
403 goto fail;
404 }
405 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
406 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
407 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
408 (unsigned long long)lastlba);
409 goto fail;
410 }
411 if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) {
412 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
413 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
414 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba));
415 goto fail;
416 }
417 /* Check that sizeof_partition_entry has the correct value */
418 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
419 pr_debug("GUID Partition Entry Size check failed.\n");
420 goto fail;
421 }
422
423 /* Sanity check partition table size */
424 pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) *
425 le32_to_cpu((*gpt)->sizeof_partition_entry);
426 if (pt_size > KMALLOC_MAX_SIZE) {
427 pr_debug("GUID Partition Table is too large: %llu > %lu bytes\n",
428 (unsigned long long)pt_size, KMALLOC_MAX_SIZE);
429 goto fail;
430 }
431
432 if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
433 goto fail;
434
435 /* Check the GUID Partition Entry Array CRC */
436 crc = efi_crc32((const unsigned char *) (*ptes), pt_size);
437
438 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
439 pr_debug("GUID Partition Entry Array CRC check failed.\n");
440 goto fail_ptes;
441 }
442
443 /* We're done, all's well */
444 return 1;
445
446 fail_ptes:
447 kfree(*ptes);
448 *ptes = NULL;
449 fail:
450 kfree(*gpt);
451 *gpt = NULL;
452 return 0;
453 }
454
455 /**
456 * is_pte_valid() - tests one PTE for validity
457 * @pte:pte to check
458 * @lastlba: last lba of the disk
459 *
460 * Description: returns 1 if valid, 0 on error.
461 */
462 static inline int
463 is_pte_valid(const gpt_entry *pte, const u64 lastlba)
464 {
465 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
466 le64_to_cpu(pte->starting_lba) > lastlba ||
467 le64_to_cpu(pte->ending_lba) > lastlba)
468 return 0;
469 return 1;
470 }
471
472 /**
473 * compare_gpts() - Search disk for valid GPT headers and PTEs
474 * @pgpt: primary GPT header
475 * @agpt: alternate GPT header
476 * @lastlba: last LBA number
477 *
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: disk parsed partitions
570 * @gpt: GPT header ptr, filled on return.
571 * @ptes: PTEs ptr, filled on return.
572 *
573 * Description: Returns 1 if valid, 0 on error.
574 * If valid, returns pointers to newly allocated GPT header and PTEs.
575 * Validity depends on PMBR being valid (or being overridden by the
576 * 'gpt' kernel command line option) and finding either the Primary
577 * GPT header and PTEs valid, or the Alternate GPT header and PTEs
578 * valid. If the Primary GPT header is not valid, the Alternate GPT header
579 * is not checked unless the 'gpt' kernel command line option is passed.
580 * This protects against devices which misreport their size, and forces
581 * the user to decide to use the Alternate GPT.
582 */
583 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
584 gpt_entry **ptes)
585 {
586 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
587 gpt_header *pgpt = NULL, *agpt = NULL;
588 gpt_entry *pptes = NULL, *aptes = NULL;
589 legacy_mbr *legacymbr;
590 sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9;
591 u64 lastlba;
592
593 if (!ptes)
594 return 0;
595
596 lastlba = last_lba(state->bdev);
597 if (!force_gpt) {
598 /* This will be added to the EFI Spec. per Intel after v1.02. */
599 legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL);
600 if (!legacymbr)
601 goto fail;
602
603 read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr));
604 good_pmbr = is_pmbr_valid(legacymbr, total_sectors);
605 kfree(legacymbr);
606
607 if (!good_pmbr)
608 goto fail;
609
610 pr_debug("Device has a %s MBR\n",
611 good_pmbr == GPT_MBR_PROTECTIVE ?
612 "protective" : "hybrid");
613 }
614
615 good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
616 &pgpt, &pptes);
617 if (good_pgpt)
618 good_agpt = is_gpt_valid(state,
619 le64_to_cpu(pgpt->alternate_lba),
620 &agpt, &aptes);
621 if (!good_agpt && force_gpt)
622 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
623
624 /* The obviously unsuccessful case */
625 if (!good_pgpt && !good_agpt)
626 goto fail;
627
628 compare_gpts(pgpt, agpt, lastlba);
629
630 /* The good cases */
631 if (good_pgpt) {
632 *gpt = pgpt;
633 *ptes = pptes;
634 kfree(agpt);
635 kfree(aptes);
636 if (!good_agpt)
637 pr_warn("Alternate GPT is invalid, using primary GPT.\n");
638 return 1;
639 }
640 else if (good_agpt) {
641 *gpt = agpt;
642 *ptes = aptes;
643 kfree(pgpt);
644 kfree(pptes);
645 pr_warn("Primary GPT is invalid, using alternate GPT.\n");
646 return 1;
647 }
648
649 fail:
650 kfree(pgpt);
651 kfree(agpt);
652 kfree(pptes);
653 kfree(aptes);
654 *gpt = NULL;
655 *ptes = NULL;
656 return 0;
657 }
658
659 /**
660 * efi_partition(struct parsed_partitions *state)
661 * @state: disk parsed partitions
662 *
663 * Description: called from check.c, if the disk contains GPT
664 * partitions, sets up partition entries in the kernel.
665 *
666 * If the first block on the disk is a legacy MBR,
667 * it will get handled by msdos_partition().
668 * If it's a Protective MBR, we'll handle it here.
669 *
670 * We do not create a Linux partition for GPT, but
671 * only for the actual data partitions.
672 * Returns:
673 * -1 if unable to read the partition table
674 * 0 if this isn't our partition table
675 * 1 if successful
676 *
677 */
678 int efi_partition(struct parsed_partitions *state)
679 {
680 gpt_header *gpt = NULL;
681 gpt_entry *ptes = NULL;
682 u32 i;
683 unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
684
685 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
686 kfree(gpt);
687 kfree(ptes);
688 return 0;
689 }
690
691 pr_debug("GUID Partition Table is valid! Yea!\n");
692
693 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
694 struct partition_meta_info *info;
695 unsigned label_count = 0;
696 unsigned label_max;
697 u64 start = le64_to_cpu(ptes[i].starting_lba);
698 u64 size = le64_to_cpu(ptes[i].ending_lba) -
699 le64_to_cpu(ptes[i].starting_lba) + 1ULL;
700
701 if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
702 continue;
703
704 put_partition(state, i+1, start * ssz, size * ssz);
705
706 /* If this is a RAID volume, tell md */
707 if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID))
708 state->parts[i + 1].flags = ADDPART_FLAG_RAID;
709
710 info = &state->parts[i + 1].info;
711 efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid);
712
713 /* Naively convert UTF16-LE to 7 bits. */
714 label_max = min(ARRAY_SIZE(info->volname) - 1,
715 ARRAY_SIZE(ptes[i].partition_name));
716 info->volname[label_max] = 0;
717 while (label_count < label_max) {
718 u8 c = ptes[i].partition_name[label_count] & 0xff;
719 if (c && !isprint(c))
720 c = '!';
721 info->volname[label_count] = c;
722 label_count++;
723 }
724 state->parts[i + 1].has_info = true;
725 }
726 kfree(ptes);
727 kfree(gpt);
728 strlcat(state->pp_buf, "\n", PAGE_SIZE);
729 return 1;
730 }