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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/kernel.h>
100#include <linux/crc32.h>
101#include <linux/ctype.h>
102#include <linux/math64.h>
103#include <linux/slab.h>
104#include "check.h"
105#include "efi.h"
106
107/* This allows a kernel command line option 'gpt' to override
108 * the test for invalid PMBR. Not __initdata because reloading
109 * the partition tables happens after init too.
110 */
111static int force_gpt;
112static int __init
113force_gpt_fn(char *str)
114{
115 force_gpt = 1;
116 return 1;
117}
118__setup("gpt", force_gpt_fn);
119
120
121/**
122 * efi_crc32() - EFI version of crc32 function
123 * @buf: buffer to calculate crc32 of
124 * @len: length of buf
125 *
126 * Description: Returns EFI-style CRC32 value for @buf
127 *
128 * This function uses the little endian Ethernet polynomial
129 * but seeds the function with ~0, and xor's with ~0 at the end.
130 * Note, the EFI Specification, v1.02, has a reference to
131 * Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
132 */
133static inline u32
134efi_crc32(const void *buf, unsigned long len)
135{
136 return (crc32(~0L, buf, len) ^ ~0L);
137}
138
139/**
140 * last_lba(): return number of last logical block of device
141 * @bdev: block device
142 *
143 * Description: Returns last LBA value on success, 0 on error.
144 * This is stored (by sd and ide-geometry) in
145 * the part[0] entry for this disk, and is the number of
146 * physical sectors available on the disk.
147 */
148static u64 last_lba(struct block_device *bdev)
149{
150 if (!bdev || !bdev->bd_inode)
151 return 0;
152 return div_u64(bdev->bd_inode->i_size,
153 bdev_logical_block_size(bdev)) - 1ULL;
154}
155
156static inline int pmbr_part_valid(gpt_mbr_record *part)
157{
158 if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT)
159 goto invalid;
160
161 /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */
162 if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA)
163 goto invalid;
164
165 return GPT_MBR_PROTECTIVE;
166invalid:
167 return 0;
168}
169
170/**
171 * is_pmbr_valid(): test Protective MBR for validity
172 * @mbr: pointer to a legacy mbr structure
173 * @total_sectors: amount of sectors in the device
174 *
175 * Description: Checks for a valid protective or hybrid
176 * master boot record (MBR). The validity of a pMBR depends
177 * on all of the following properties:
178 * 1) MSDOS signature is in the last two bytes of the MBR
179 * 2) One partition of type 0xEE is found
180 *
181 * In addition, a hybrid MBR will have up to three additional
182 * primary partitions, which point to the same space that's
183 * marked out by up to three GPT partitions.
184 *
185 * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or
186 * GPT_MBR_HYBRID depending on the device layout.
187 */
188static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors)
189{
190 uint32_t sz = 0;
191 int i, part = 0, ret = 0; /* invalid by default */
192
193 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
194 goto done;
195
196 for (i = 0; i < 4; i++) {
197 ret = pmbr_part_valid(&mbr->partition_record[i]);
198 if (ret == GPT_MBR_PROTECTIVE) {
199 part = i;
200 /*
201 * Ok, we at least know that there's a protective MBR,
202 * now check if there are other partition types for
203 * hybrid MBR.
204 */
205 goto check_hybrid;
206 }
207 }
208
209 if (ret != GPT_MBR_PROTECTIVE)
210 goto done;
211check_hybrid:
212 for (i = 0; i < 4; i++)
213 if ((mbr->partition_record[i].os_type !=
214 EFI_PMBR_OSTYPE_EFI_GPT) &&
215 (mbr->partition_record[i].os_type != 0x00))
216 ret = GPT_MBR_HYBRID;
217
218 /*
219 * Protective MBRs take up the lesser of the whole disk
220 * or 2 TiB (32bit LBA), ignoring the rest of the disk.
221 * Some partitioning programs, nonetheless, choose to set
222 * the size to the maximum 32-bit limitation, disregarding
223 * the disk size.
224 *
225 * Hybrid MBRs do not necessarily comply with this.
226 *
227 * Consider a bad value here to be a warning to support dd'ing
228 * an image from a smaller disk to a larger disk.
229 */
230 if (ret == GPT_MBR_PROTECTIVE) {
231 sz = le32_to_cpu(mbr->partition_record[part].size_in_lba);
232 if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF)
233 pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n",
234 sz, min_t(uint32_t,
235 total_sectors - 1, 0xFFFFFFFF));
236 }
237done:
238 return ret;
239}
240
241/**
242 * read_lba(): Read bytes from disk, starting at given LBA
243 * @state: disk parsed partitions
244 * @lba: the Logical Block Address of the partition table
245 * @buffer: destination buffer
246 * @count: bytes to read
247 *
248 * Description: Reads @count bytes from @state->bdev into @buffer.
249 * Returns number of bytes read on success, 0 on error.
250 */
251static size_t read_lba(struct parsed_partitions *state,
252 u64 lba, u8 *buffer, size_t count)
253{
254 size_t totalreadcount = 0;
255 struct block_device *bdev = state->bdev;
256 sector_t n = lba * (bdev_logical_block_size(bdev) / 512);
257
258 if (!buffer || lba > last_lba(bdev))
259 return 0;
260
261 while (count) {
262 int copied = 512;
263 Sector sect;
264 unsigned char *data = read_part_sector(state, n++, §);
265 if (!data)
266 break;
267 if (copied > count)
268 copied = count;
269 memcpy(buffer, data, copied);
270 put_dev_sector(sect);
271 buffer += copied;
272 totalreadcount +=copied;
273 count -= copied;
274 }
275 return totalreadcount;
276}
277
278/**
279 * alloc_read_gpt_entries(): reads partition entries from disk
280 * @state: disk parsed partitions
281 * @gpt: GPT header
282 *
283 * Description: Returns ptes on success, NULL on error.
284 * Allocates space for PTEs based on information found in @gpt.
285 * Notes: remember to free pte when you're done!
286 */
287static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state,
288 gpt_header *gpt)
289{
290 size_t count;
291 gpt_entry *pte;
292
293 if (!gpt)
294 return NULL;
295
296 count = le32_to_cpu(gpt->num_partition_entries) *
297 le32_to_cpu(gpt->sizeof_partition_entry);
298 if (!count)
299 return NULL;
300 pte = kmalloc(count, GFP_KERNEL);
301 if (!pte)
302 return NULL;
303
304 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
305 (u8 *) pte, count) < count) {
306 kfree(pte);
307 pte=NULL;
308 return NULL;
309 }
310 return pte;
311}
312
313/**
314 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
315 * @state: disk parsed partitions
316 * @lba: the Logical Block Address of the partition table
317 *
318 * Description: returns GPT header on success, NULL on error. Allocates
319 * and fills a GPT header starting at @ from @state->bdev.
320 * Note: remember to free gpt when finished with it.
321 */
322static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
323 u64 lba)
324{
325 gpt_header *gpt;
326 unsigned ssz = bdev_logical_block_size(state->bdev);
327
328 gpt = kmalloc(ssz, GFP_KERNEL);
329 if (!gpt)
330 return NULL;
331
332 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
333 kfree(gpt);
334 gpt=NULL;
335 return NULL;
336 }
337
338 return gpt;
339}
340
341/**
342 * is_gpt_valid() - tests one GPT header and PTEs for validity
343 * @state: disk parsed partitions
344 * @lba: logical block address of the GPT header to test
345 * @gpt: GPT header ptr, filled on return.
346 * @ptes: PTEs ptr, filled on return.
347 *
348 * Description: returns 1 if valid, 0 on error.
349 * If valid, returns pointers to newly allocated GPT header and PTEs.
350 */
351static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
352 gpt_header **gpt, gpt_entry **ptes)
353{
354 u32 crc, origcrc;
355 u64 lastlba;
356
357 if (!ptes)
358 return 0;
359 if (!(*gpt = alloc_read_gpt_header(state, lba)))
360 return 0;
361
362 /* Check the GUID Partition Table signature */
363 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
364 pr_debug("GUID Partition Table Header signature is wrong:"
365 "%lld != %lld\n",
366 (unsigned long long)le64_to_cpu((*gpt)->signature),
367 (unsigned long long)GPT_HEADER_SIGNATURE);
368 goto fail;
369 }
370
371 /* Check the GUID Partition Table header size is too big */
372 if (le32_to_cpu((*gpt)->header_size) >
373 bdev_logical_block_size(state->bdev)) {
374 pr_debug("GUID Partition Table Header size is too large: %u > %u\n",
375 le32_to_cpu((*gpt)->header_size),
376 bdev_logical_block_size(state->bdev));
377 goto fail;
378 }
379
380 /* Check the GUID Partition Table header size is too small */
381 if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) {
382 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n",
383 le32_to_cpu((*gpt)->header_size),
384 sizeof(gpt_header));
385 goto fail;
386 }
387
388 /* Check the GUID Partition Table CRC */
389 origcrc = le32_to_cpu((*gpt)->header_crc32);
390 (*gpt)->header_crc32 = 0;
391 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
392
393 if (crc != origcrc) {
394 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
395 crc, origcrc);
396 goto fail;
397 }
398 (*gpt)->header_crc32 = cpu_to_le32(origcrc);
399
400 /* Check that the my_lba entry points to the LBA that contains
401 * the GUID Partition Table */
402 if (le64_to_cpu((*gpt)->my_lba) != lba) {
403 pr_debug("GPT my_lba incorrect: %lld != %lld\n",
404 (unsigned long long)le64_to_cpu((*gpt)->my_lba),
405 (unsigned long long)lba);
406 goto fail;
407 }
408
409 /* Check the first_usable_lba and last_usable_lba are
410 * within the disk.
411 */
412 lastlba = last_lba(state->bdev);
413 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
414 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
415 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
416 (unsigned long long)lastlba);
417 goto fail;
418 }
419 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
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)lastlba);
423 goto fail;
424 }
425 if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) {
426 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
427 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
428 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba));
429 goto fail;
430 }
431 /* Check that sizeof_partition_entry has the correct value */
432 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
433 pr_debug("GUID Partitition Entry Size check failed.\n");
434 goto fail;
435 }
436
437 if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
438 goto fail;
439
440 /* Check the GUID Partition Entry Array CRC */
441 crc = efi_crc32((const unsigned char *) (*ptes),
442 le32_to_cpu((*gpt)->num_partition_entries) *
443 le32_to_cpu((*gpt)->sizeof_partition_entry));
444
445 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
446 pr_debug("GUID Partitition Entry Array CRC check failed.\n");
447 goto fail_ptes;
448 }
449
450 /* We're done, all's well */
451 return 1;
452
453 fail_ptes:
454 kfree(*ptes);
455 *ptes = NULL;
456 fail:
457 kfree(*gpt);
458 *gpt = NULL;
459 return 0;
460}
461
462/**
463 * is_pte_valid() - tests one PTE for validity
464 * @pte:pte to check
465 * @lastlba: last lba of the disk
466 *
467 * Description: returns 1 if valid, 0 on error.
468 */
469static inline int
470is_pte_valid(const gpt_entry *pte, const u64 lastlba)
471{
472 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
473 le64_to_cpu(pte->starting_lba) > lastlba ||
474 le64_to_cpu(pte->ending_lba) > lastlba)
475 return 0;
476 return 1;
477}
478
479/**
480 * compare_gpts() - Search disk for valid GPT headers and PTEs
481 * @pgpt: primary GPT header
482 * @agpt: alternate GPT header
483 * @lastlba: last LBA number
484 *
485 * Description: Returns nothing. Sanity checks pgpt and agpt fields
486 * and prints warnings on discrepancies.
487 *
488 */
489static void
490compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
491{
492 int error_found = 0;
493 if (!pgpt || !agpt)
494 return;
495 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
496 pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n");
497 pr_warn("GPT:%lld != %lld\n",
498 (unsigned long long)le64_to_cpu(pgpt->my_lba),
499 (unsigned long long)le64_to_cpu(agpt->alternate_lba));
500 error_found++;
501 }
502 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
503 pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n");
504 pr_warn("GPT:%lld != %lld\n",
505 (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
506 (unsigned long long)le64_to_cpu(agpt->my_lba));
507 error_found++;
508 }
509 if (le64_to_cpu(pgpt->first_usable_lba) !=
510 le64_to_cpu(agpt->first_usable_lba)) {
511 pr_warn("GPT:first_usable_lbas don't match.\n");
512 pr_warn("GPT:%lld != %lld\n",
513 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
514 (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
515 error_found++;
516 }
517 if (le64_to_cpu(pgpt->last_usable_lba) !=
518 le64_to_cpu(agpt->last_usable_lba)) {
519 pr_warn("GPT:last_usable_lbas don't match.\n");
520 pr_warn("GPT:%lld != %lld\n",
521 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
522 (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
523 error_found++;
524 }
525 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
526 pr_warn("GPT:disk_guids don't match.\n");
527 error_found++;
528 }
529 if (le32_to_cpu(pgpt->num_partition_entries) !=
530 le32_to_cpu(agpt->num_partition_entries)) {
531 pr_warn("GPT:num_partition_entries don't match: "
532 "0x%x != 0x%x\n",
533 le32_to_cpu(pgpt->num_partition_entries),
534 le32_to_cpu(agpt->num_partition_entries));
535 error_found++;
536 }
537 if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
538 le32_to_cpu(agpt->sizeof_partition_entry)) {
539 pr_warn("GPT:sizeof_partition_entry values don't match: "
540 "0x%x != 0x%x\n",
541 le32_to_cpu(pgpt->sizeof_partition_entry),
542 le32_to_cpu(agpt->sizeof_partition_entry));
543 error_found++;
544 }
545 if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
546 le32_to_cpu(agpt->partition_entry_array_crc32)) {
547 pr_warn("GPT:partition_entry_array_crc32 values don't match: "
548 "0x%x != 0x%x\n",
549 le32_to_cpu(pgpt->partition_entry_array_crc32),
550 le32_to_cpu(agpt->partition_entry_array_crc32));
551 error_found++;
552 }
553 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
554 pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
555 pr_warn("GPT:%lld != %lld\n",
556 (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
557 (unsigned long long)lastlba);
558 error_found++;
559 }
560
561 if (le64_to_cpu(agpt->my_lba) != lastlba) {
562 pr_warn("GPT:Alternate GPT header not at the end of the disk.\n");
563 pr_warn("GPT:%lld != %lld\n",
564 (unsigned long long)le64_to_cpu(agpt->my_lba),
565 (unsigned long long)lastlba);
566 error_found++;
567 }
568
569 if (error_found)
570 pr_warn("GPT: Use GNU Parted to correct GPT errors.\n");
571 return;
572}
573
574/**
575 * find_valid_gpt() - Search disk for valid GPT headers and PTEs
576 * @state: disk parsed partitions
577 * @gpt: GPT header ptr, filled on return.
578 * @ptes: PTEs ptr, filled on return.
579 *
580 * Description: Returns 1 if valid, 0 on error.
581 * If valid, returns pointers to newly allocated GPT header and PTEs.
582 * Validity depends on PMBR being valid (or being overridden by the
583 * 'gpt' kernel command line option) and finding either the Primary
584 * GPT header and PTEs valid, or the Alternate GPT header and PTEs
585 * valid. If the Primary GPT header is not valid, the Alternate GPT header
586 * is not checked unless the 'gpt' kernel command line option is passed.
587 * This protects against devices which misreport their size, and forces
588 * the user to decide to use the Alternate GPT.
589 */
590static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
591 gpt_entry **ptes)
592{
593 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
594 gpt_header *pgpt = NULL, *agpt = NULL;
595 gpt_entry *pptes = NULL, *aptes = NULL;
596 legacy_mbr *legacymbr;
597 sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9;
598 u64 lastlba;
599
600 if (!ptes)
601 return 0;
602
603 lastlba = last_lba(state->bdev);
604 if (!force_gpt) {
605 /* This will be added to the EFI Spec. per Intel after v1.02. */
606 legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL);
607 if (!legacymbr)
608 goto fail;
609
610 read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr));
611 good_pmbr = is_pmbr_valid(legacymbr, total_sectors);
612 kfree(legacymbr);
613
614 if (!good_pmbr)
615 goto fail;
616
617 pr_debug("Device has a %s MBR\n",
618 good_pmbr == GPT_MBR_PROTECTIVE ?
619 "protective" : "hybrid");
620 }
621
622 good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
623 &pgpt, &pptes);
624 if (good_pgpt)
625 good_agpt = is_gpt_valid(state,
626 le64_to_cpu(pgpt->alternate_lba),
627 &agpt, &aptes);
628 if (!good_agpt && force_gpt)
629 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
630
631 /* The obviously unsuccessful case */
632 if (!good_pgpt && !good_agpt)
633 goto fail;
634
635 compare_gpts(pgpt, agpt, lastlba);
636
637 /* The good cases */
638 if (good_pgpt) {
639 *gpt = pgpt;
640 *ptes = pptes;
641 kfree(agpt);
642 kfree(aptes);
643 if (!good_agpt)
644 pr_warn("Alternate GPT is invalid, using primary GPT.\n");
645 return 1;
646 }
647 else if (good_agpt) {
648 *gpt = agpt;
649 *ptes = aptes;
650 kfree(pgpt);
651 kfree(pptes);
652 pr_warn("Primary GPT is invalid, using alternate GPT.\n");
653 return 1;
654 }
655
656 fail:
657 kfree(pgpt);
658 kfree(agpt);
659 kfree(pptes);
660 kfree(aptes);
661 *gpt = NULL;
662 *ptes = NULL;
663 return 0;
664}
665
666/**
667 * efi_partition(struct parsed_partitions *state)
668 * @state: disk parsed partitions
669 *
670 * Description: called from check.c, if the disk contains GPT
671 * partitions, sets up partition entries in the kernel.
672 *
673 * If the first block on the disk is a legacy MBR,
674 * it will get handled by msdos_partition().
675 * If it's a Protective MBR, we'll handle it here.
676 *
677 * We do not create a Linux partition for GPT, but
678 * only for the actual data partitions.
679 * Returns:
680 * -1 if unable to read the partition table
681 * 0 if this isn't our partition table
682 * 1 if successful
683 *
684 */
685int efi_partition(struct parsed_partitions *state)
686{
687 gpt_header *gpt = NULL;
688 gpt_entry *ptes = NULL;
689 u32 i;
690 unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
691
692 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
693 kfree(gpt);
694 kfree(ptes);
695 return 0;
696 }
697
698 pr_debug("GUID Partition Table is valid! Yea!\n");
699
700 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
701 struct partition_meta_info *info;
702 unsigned label_count = 0;
703 unsigned label_max;
704 u64 start = le64_to_cpu(ptes[i].starting_lba);
705 u64 size = le64_to_cpu(ptes[i].ending_lba) -
706 le64_to_cpu(ptes[i].starting_lba) + 1ULL;
707
708 if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
709 continue;
710
711 put_partition(state, i+1, start * ssz, size * ssz);
712
713 /* If this is a RAID volume, tell md */
714 if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID))
715 state->parts[i + 1].flags = ADDPART_FLAG_RAID;
716
717 info = &state->parts[i + 1].info;
718 efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid);
719
720 /* Naively convert UTF16-LE to 7 bits. */
721 label_max = min(ARRAY_SIZE(info->volname) - 1,
722 ARRAY_SIZE(ptes[i].partition_name));
723 info->volname[label_max] = 0;
724 while (label_count < label_max) {
725 u8 c = ptes[i].partition_name[label_count] & 0xff;
726 if (c && !isprint(c))
727 c = '!';
728 info->volname[label_count] = c;
729 label_count++;
730 }
731 state->parts[i + 1].has_info = true;
732 }
733 kfree(ptes);
734 kfree(gpt);
735 strlcat(state->pp_buf, "\n", PAGE_SIZE);
736 return 1;
737}
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 */
97static int force_gpt;
98static int __init
99force_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 */
119static inline u32
120efi_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 * @disk: 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 */
134static u64 last_lba(struct gendisk *disk)
135{
136 return div_u64(bdev_nr_bytes(disk->part0),
137 queue_logical_block_size(disk->queue)) - 1ULL;
138}
139
140static inline int pmbr_part_valid(gpt_mbr_record *part)
141{
142 if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT)
143 goto invalid;
144
145 /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */
146 if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA)
147 goto invalid;
148
149 return GPT_MBR_PROTECTIVE;
150invalid:
151 return 0;
152}
153
154/**
155 * is_pmbr_valid(): test Protective MBR for validity
156 * @mbr: pointer to a legacy mbr structure
157 * @total_sectors: amount of sectors in the device
158 *
159 * Description: Checks for a valid protective or hybrid
160 * master boot record (MBR). The validity of a pMBR depends
161 * on all of the following properties:
162 * 1) MSDOS signature is in the last two bytes of the MBR
163 * 2) One partition of type 0xEE is found
164 *
165 * In addition, a hybrid MBR will have up to three additional
166 * primary partitions, which point to the same space that's
167 * marked out by up to three GPT partitions.
168 *
169 * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or
170 * GPT_MBR_HYBRID depending on the device layout.
171 */
172static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors)
173{
174 uint32_t sz = 0;
175 int i, part = 0, ret = 0; /* invalid by default */
176
177 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
178 goto done;
179
180 for (i = 0; i < 4; i++) {
181 ret = pmbr_part_valid(&mbr->partition_record[i]);
182 if (ret == GPT_MBR_PROTECTIVE) {
183 part = i;
184 /*
185 * Ok, we at least know that there's a protective MBR,
186 * now check if there are other partition types for
187 * hybrid MBR.
188 */
189 goto check_hybrid;
190 }
191 }
192
193 if (ret != GPT_MBR_PROTECTIVE)
194 goto done;
195check_hybrid:
196 for (i = 0; i < 4; i++)
197 if ((mbr->partition_record[i].os_type !=
198 EFI_PMBR_OSTYPE_EFI_GPT) &&
199 (mbr->partition_record[i].os_type != 0x00))
200 ret = GPT_MBR_HYBRID;
201
202 /*
203 * Protective MBRs take up the lesser of the whole disk
204 * or 2 TiB (32bit LBA), ignoring the rest of the disk.
205 * Some partitioning programs, nonetheless, choose to set
206 * the size to the maximum 32-bit limitation, disregarding
207 * the disk size.
208 *
209 * Hybrid MBRs do not necessarily comply with this.
210 *
211 * Consider a bad value here to be a warning to support dd'ing
212 * an image from a smaller disk to a larger disk.
213 */
214 if (ret == GPT_MBR_PROTECTIVE) {
215 sz = le32_to_cpu(mbr->partition_record[part].size_in_lba);
216 if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF)
217 pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n",
218 sz, min_t(uint32_t,
219 total_sectors - 1, 0xFFFFFFFF));
220 }
221done:
222 return ret;
223}
224
225/**
226 * read_lba(): Read bytes from disk, starting at given LBA
227 * @state: disk parsed partitions
228 * @lba: the Logical Block Address of the partition table
229 * @buffer: destination buffer
230 * @count: bytes to read
231 *
232 * Description: Reads @count bytes from @state->disk into @buffer.
233 * Returns number of bytes read on success, 0 on error.
234 */
235static size_t read_lba(struct parsed_partitions *state,
236 u64 lba, u8 *buffer, size_t count)
237{
238 size_t totalreadcount = 0;
239 sector_t n = lba *
240 (queue_logical_block_size(state->disk->queue) / 512);
241
242 if (!buffer || lba > last_lba(state->disk))
243 return 0;
244
245 while (count) {
246 int copied = 512;
247 Sector sect;
248 unsigned char *data = read_part_sector(state, n++, §);
249 if (!data)
250 break;
251 if (copied > count)
252 copied = count;
253 memcpy(buffer, data, copied);
254 put_dev_sector(sect);
255 buffer += copied;
256 totalreadcount +=copied;
257 count -= copied;
258 }
259 return totalreadcount;
260}
261
262/**
263 * alloc_read_gpt_entries(): reads partition entries from disk
264 * @state: disk parsed partitions
265 * @gpt: GPT header
266 *
267 * Description: Returns ptes on success, NULL on error.
268 * Allocates space for PTEs based on information found in @gpt.
269 * Notes: remember to free pte when you're done!
270 */
271static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state,
272 gpt_header *gpt)
273{
274 size_t count;
275 gpt_entry *pte;
276
277 if (!gpt)
278 return NULL;
279
280 count = (size_t)le32_to_cpu(gpt->num_partition_entries) *
281 le32_to_cpu(gpt->sizeof_partition_entry);
282 if (!count)
283 return NULL;
284 pte = kmalloc(count, GFP_KERNEL);
285 if (!pte)
286 return NULL;
287
288 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
289 (u8 *) pte, count) < count) {
290 kfree(pte);
291 pte=NULL;
292 return NULL;
293 }
294 return pte;
295}
296
297/**
298 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
299 * @state: disk parsed partitions
300 * @lba: the Logical Block Address of the partition table
301 *
302 * Description: returns GPT header on success, NULL on error. Allocates
303 * and fills a GPT header starting at @ from @state->disk.
304 * Note: remember to free gpt when finished with it.
305 */
306static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
307 u64 lba)
308{
309 gpt_header *gpt;
310 unsigned ssz = queue_logical_block_size(state->disk->queue);
311
312 gpt = kmalloc(ssz, GFP_KERNEL);
313 if (!gpt)
314 return NULL;
315
316 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
317 kfree(gpt);
318 gpt=NULL;
319 return NULL;
320 }
321
322 return gpt;
323}
324
325/**
326 * is_gpt_valid() - tests one GPT header and PTEs for validity
327 * @state: disk parsed partitions
328 * @lba: logical block address of the GPT header to test
329 * @gpt: GPT header ptr, filled on return.
330 * @ptes: PTEs ptr, filled on return.
331 *
332 * Description: returns 1 if valid, 0 on error.
333 * If valid, returns pointers to newly allocated GPT header and PTEs.
334 */
335static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
336 gpt_header **gpt, gpt_entry **ptes)
337{
338 u32 crc, origcrc;
339 u64 lastlba, pt_size;
340
341 if (!ptes)
342 return 0;
343 if (!(*gpt = alloc_read_gpt_header(state, lba)))
344 return 0;
345
346 /* Check the GUID Partition Table signature */
347 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
348 pr_debug("GUID Partition Table Header signature is wrong:"
349 "%lld != %lld\n",
350 (unsigned long long)le64_to_cpu((*gpt)->signature),
351 (unsigned long long)GPT_HEADER_SIGNATURE);
352 goto fail;
353 }
354
355 /* Check the GUID Partition Table header size is too big */
356 if (le32_to_cpu((*gpt)->header_size) >
357 queue_logical_block_size(state->disk->queue)) {
358 pr_debug("GUID Partition Table Header size is too large: %u > %u\n",
359 le32_to_cpu((*gpt)->header_size),
360 queue_logical_block_size(state->disk->queue));
361 goto fail;
362 }
363
364 /* Check the GUID Partition Table header size is too small */
365 if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) {
366 pr_debug("GUID Partition Table Header size is too small: %u < %zu\n",
367 le32_to_cpu((*gpt)->header_size),
368 sizeof(gpt_header));
369 goto fail;
370 }
371
372 /* Check the GUID Partition Table CRC */
373 origcrc = le32_to_cpu((*gpt)->header_crc32);
374 (*gpt)->header_crc32 = 0;
375 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
376
377 if (crc != origcrc) {
378 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
379 crc, origcrc);
380 goto fail;
381 }
382 (*gpt)->header_crc32 = cpu_to_le32(origcrc);
383
384 /* Check that the my_lba entry points to the LBA that contains
385 * the GUID Partition Table */
386 if (le64_to_cpu((*gpt)->my_lba) != lba) {
387 pr_debug("GPT my_lba incorrect: %lld != %lld\n",
388 (unsigned long long)le64_to_cpu((*gpt)->my_lba),
389 (unsigned long long)lba);
390 goto fail;
391 }
392
393 /* Check the first_usable_lba and last_usable_lba are
394 * within the disk.
395 */
396 lastlba = last_lba(state->disk);
397 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
398 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
399 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
400 (unsigned long long)lastlba);
401 goto fail;
402 }
403 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
404 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
405 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
406 (unsigned long long)lastlba);
407 goto fail;
408 }
409 if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) {
410 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
411 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
412 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba));
413 goto fail;
414 }
415 /* Check that sizeof_partition_entry has the correct value */
416 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
417 pr_debug("GUID Partition Entry Size check failed.\n");
418 goto fail;
419 }
420
421 /* Sanity check partition table size */
422 pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) *
423 le32_to_cpu((*gpt)->sizeof_partition_entry);
424 if (pt_size > KMALLOC_MAX_SIZE) {
425 pr_debug("GUID Partition Table is too large: %llu > %lu bytes\n",
426 (unsigned long long)pt_size, KMALLOC_MAX_SIZE);
427 goto fail;
428 }
429
430 if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
431 goto fail;
432
433 /* Check the GUID Partition Entry Array CRC */
434 crc = efi_crc32((const unsigned char *) (*ptes), pt_size);
435
436 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
437 pr_debug("GUID Partition Entry Array CRC check failed.\n");
438 goto fail_ptes;
439 }
440
441 /* We're done, all's well */
442 return 1;
443
444 fail_ptes:
445 kfree(*ptes);
446 *ptes = NULL;
447 fail:
448 kfree(*gpt);
449 *gpt = NULL;
450 return 0;
451}
452
453/**
454 * is_pte_valid() - tests one PTE for validity
455 * @pte:pte to check
456 * @lastlba: last lba of the disk
457 *
458 * Description: returns 1 if valid, 0 on error.
459 */
460static inline int
461is_pte_valid(const gpt_entry *pte, const u64 lastlba)
462{
463 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
464 le64_to_cpu(pte->starting_lba) > lastlba ||
465 le64_to_cpu(pte->ending_lba) > lastlba)
466 return 0;
467 return 1;
468}
469
470/**
471 * compare_gpts() - Search disk for valid GPT headers and PTEs
472 * @pgpt: primary GPT header
473 * @agpt: alternate GPT header
474 * @lastlba: last LBA number
475 *
476 * Description: Returns nothing. Sanity checks pgpt and agpt fields
477 * and prints warnings on discrepancies.
478 *
479 */
480static void
481compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
482{
483 int error_found = 0;
484 if (!pgpt || !agpt)
485 return;
486 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
487 pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n");
488 pr_warn("GPT:%lld != %lld\n",
489 (unsigned long long)le64_to_cpu(pgpt->my_lba),
490 (unsigned long long)le64_to_cpu(agpt->alternate_lba));
491 error_found++;
492 }
493 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
494 pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n");
495 pr_warn("GPT:%lld != %lld\n",
496 (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
497 (unsigned long long)le64_to_cpu(agpt->my_lba));
498 error_found++;
499 }
500 if (le64_to_cpu(pgpt->first_usable_lba) !=
501 le64_to_cpu(agpt->first_usable_lba)) {
502 pr_warn("GPT:first_usable_lbas don't match.\n");
503 pr_warn("GPT:%lld != %lld\n",
504 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
505 (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
506 error_found++;
507 }
508 if (le64_to_cpu(pgpt->last_usable_lba) !=
509 le64_to_cpu(agpt->last_usable_lba)) {
510 pr_warn("GPT:last_usable_lbas don't match.\n");
511 pr_warn("GPT:%lld != %lld\n",
512 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
513 (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
514 error_found++;
515 }
516 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
517 pr_warn("GPT:disk_guids don't match.\n");
518 error_found++;
519 }
520 if (le32_to_cpu(pgpt->num_partition_entries) !=
521 le32_to_cpu(agpt->num_partition_entries)) {
522 pr_warn("GPT:num_partition_entries don't match: "
523 "0x%x != 0x%x\n",
524 le32_to_cpu(pgpt->num_partition_entries),
525 le32_to_cpu(agpt->num_partition_entries));
526 error_found++;
527 }
528 if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
529 le32_to_cpu(agpt->sizeof_partition_entry)) {
530 pr_warn("GPT:sizeof_partition_entry values don't match: "
531 "0x%x != 0x%x\n",
532 le32_to_cpu(pgpt->sizeof_partition_entry),
533 le32_to_cpu(agpt->sizeof_partition_entry));
534 error_found++;
535 }
536 if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
537 le32_to_cpu(agpt->partition_entry_array_crc32)) {
538 pr_warn("GPT:partition_entry_array_crc32 values don't match: "
539 "0x%x != 0x%x\n",
540 le32_to_cpu(pgpt->partition_entry_array_crc32),
541 le32_to_cpu(agpt->partition_entry_array_crc32));
542 error_found++;
543 }
544 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
545 pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
546 pr_warn("GPT:%lld != %lld\n",
547 (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
548 (unsigned long long)lastlba);
549 error_found++;
550 }
551
552 if (le64_to_cpu(agpt->my_lba) != lastlba) {
553 pr_warn("GPT:Alternate GPT header not at the end of the disk.\n");
554 pr_warn("GPT:%lld != %lld\n",
555 (unsigned long long)le64_to_cpu(agpt->my_lba),
556 (unsigned long long)lastlba);
557 error_found++;
558 }
559
560 if (error_found)
561 pr_warn("GPT: Use GNU Parted to correct GPT errors.\n");
562 return;
563}
564
565/**
566 * find_valid_gpt() - Search disk for valid GPT headers and PTEs
567 * @state: disk parsed partitions
568 * @gpt: GPT header ptr, filled on return.
569 * @ptes: PTEs ptr, filled on return.
570 *
571 * Description: Returns 1 if valid, 0 on error.
572 * If valid, returns pointers to newly allocated GPT header and PTEs.
573 * Validity depends on PMBR being valid (or being overridden by the
574 * 'gpt' kernel command line option) and finding either the Primary
575 * GPT header and PTEs valid, or the Alternate GPT header and PTEs
576 * valid. If the Primary GPT header is not valid, the Alternate GPT header
577 * is not checked unless the 'gpt' kernel command line option is passed.
578 * This protects against devices which misreport their size, and forces
579 * the user to decide to use the Alternate GPT.
580 */
581static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
582 gpt_entry **ptes)
583{
584 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
585 gpt_header *pgpt = NULL, *agpt = NULL;
586 gpt_entry *pptes = NULL, *aptes = NULL;
587 legacy_mbr *legacymbr;
588 struct gendisk *disk = state->disk;
589 const struct block_device_operations *fops = disk->fops;
590 sector_t total_sectors = get_capacity(state->disk);
591 u64 lastlba;
592
593 if (!ptes)
594 return 0;
595
596 lastlba = last_lba(state->disk);
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 if (!good_agpt && force_gpt && fops->alternative_gpt_sector) {
625 sector_t agpt_sector;
626 int err;
627
628 err = fops->alternative_gpt_sector(disk, &agpt_sector);
629 if (!err)
630 good_agpt = is_gpt_valid(state, agpt_sector,
631 &agpt, &aptes);
632 }
633
634 /* The obviously unsuccessful case */
635 if (!good_pgpt && !good_agpt)
636 goto fail;
637
638 compare_gpts(pgpt, agpt, lastlba);
639
640 /* The good cases */
641 if (good_pgpt) {
642 *gpt = pgpt;
643 *ptes = pptes;
644 kfree(agpt);
645 kfree(aptes);
646 if (!good_agpt)
647 pr_warn("Alternate GPT is invalid, using primary GPT.\n");
648 return 1;
649 }
650 else if (good_agpt) {
651 *gpt = agpt;
652 *ptes = aptes;
653 kfree(pgpt);
654 kfree(pptes);
655 pr_warn("Primary GPT is invalid, using alternate GPT.\n");
656 return 1;
657 }
658
659 fail:
660 kfree(pgpt);
661 kfree(agpt);
662 kfree(pptes);
663 kfree(aptes);
664 *gpt = NULL;
665 *ptes = NULL;
666 return 0;
667}
668
669/**
670 * utf16_le_to_7bit(): Naively converts a UTF-16LE string to 7-bit ASCII characters
671 * @in: input UTF-16LE string
672 * @size: size of the input string
673 * @out: output string ptr, should be capable to store @size+1 characters
674 *
675 * Description: Converts @size UTF16-LE symbols from @in string to 7-bit
676 * ASCII characters and stores them to @out. Adds trailing zero to @out array.
677 */
678static void utf16_le_to_7bit(const __le16 *in, unsigned int size, u8 *out)
679{
680 unsigned int i = 0;
681
682 out[size] = 0;
683
684 while (i < size) {
685 u8 c = le16_to_cpu(in[i]) & 0x7f;
686
687 if (c && !isprint(c))
688 c = '!';
689 out[i] = c;
690 i++;
691 }
692}
693
694/**
695 * efi_partition - scan for GPT partitions
696 * @state: disk parsed partitions
697 *
698 * Description: called from check.c, if the disk contains GPT
699 * partitions, sets up partition entries in the kernel.
700 *
701 * If the first block on the disk is a legacy MBR,
702 * it will get handled by msdos_partition().
703 * If it's a Protective MBR, we'll handle it here.
704 *
705 * We do not create a Linux partition for GPT, but
706 * only for the actual data partitions.
707 * Returns:
708 * -1 if unable to read the partition table
709 * 0 if this isn't our partition table
710 * 1 if successful
711 *
712 */
713int efi_partition(struct parsed_partitions *state)
714{
715 gpt_header *gpt = NULL;
716 gpt_entry *ptes = NULL;
717 u32 i;
718 unsigned ssz = queue_logical_block_size(state->disk->queue) / 512;
719
720 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
721 kfree(gpt);
722 kfree(ptes);
723 return 0;
724 }
725
726 pr_debug("GUID Partition Table is valid! Yea!\n");
727
728 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
729 struct partition_meta_info *info;
730 unsigned label_max;
731 u64 start = le64_to_cpu(ptes[i].starting_lba);
732 u64 size = le64_to_cpu(ptes[i].ending_lba) -
733 le64_to_cpu(ptes[i].starting_lba) + 1ULL;
734
735 if (!is_pte_valid(&ptes[i], last_lba(state->disk)))
736 continue;
737
738 put_partition(state, i+1, start * ssz, size * ssz);
739
740 /* If this is a RAID volume, tell md */
741 if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID))
742 state->parts[i + 1].flags = ADDPART_FLAG_RAID;
743
744 info = &state->parts[i + 1].info;
745 efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid);
746
747 /* Naively convert UTF16-LE to 7 bits. */
748 label_max = min(ARRAY_SIZE(info->volname) - 1,
749 ARRAY_SIZE(ptes[i].partition_name));
750 utf16_le_to_7bit(ptes[i].partition_name, label_max, info->volname);
751 state->parts[i + 1].has_info = true;
752 }
753 kfree(ptes);
754 kfree(gpt);
755 strlcat(state->pp_buf, "\n", PAGE_SIZE);
756 return 1;
757}