Line data Source code
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 0 : force_gpt_fn(char *str)
100 : {
101 0 : force_gpt = 1;
102 0 : 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 0 : 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 : */
134 : static u64 last_lba(struct gendisk *disk)
135 : {
136 0 : return div_u64(bdev_nr_bytes(disk->part0),
137 0 : queue_logical_block_size(disk->queue)) - 1ULL;
138 : }
139 :
140 : static inline int pmbr_part_valid(gpt_mbr_record *part)
141 : {
142 0 : 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 0 : if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA)
147 : goto invalid;
148 :
149 : return GPT_MBR_PROTECTIVE;
150 : invalid:
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 : */
172 0 : static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors)
173 : {
174 0 : uint32_t sz = 0;
175 0 : int i, part = 0, ret = 0; /* invalid by default */
176 :
177 0 : if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
178 : goto done;
179 :
180 0 : for (i = 0; i < 4; i++) {
181 0 : ret = pmbr_part_valid(&mbr->partition_record[i]);
182 0 : 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 0 : if (ret != GPT_MBR_PROTECTIVE)
194 : goto done;
195 : check_hybrid:
196 0 : for (i = 0; i < 4; i++)
197 0 : if ((mbr->partition_record[i].os_type !=
198 0 : EFI_PMBR_OSTYPE_EFI_GPT) &&
199 : (mbr->partition_record[i].os_type != 0x00))
200 0 : 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 : }
221 : done:
222 0 : 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 : */
235 0 : static size_t read_lba(struct parsed_partitions *state,
236 : u64 lba, u8 *buffer, size_t count)
237 : {
238 0 : size_t totalreadcount = 0;
239 0 : sector_t n = lba *
240 0 : (queue_logical_block_size(state->disk->queue) / 512);
241 :
242 0 : if (!buffer || lba > last_lba(state->disk))
243 : return 0;
244 :
245 0 : while (count) {
246 0 : int copied = 512;
247 : Sector sect;
248 0 : unsigned char *data = read_part_sector(state, n++, §);
249 0 : if (!data)
250 : break;
251 0 : if (copied > count)
252 0 : copied = count;
253 0 : memcpy(buffer, data, copied);
254 0 : put_dev_sector(sect);
255 0 : buffer += copied;
256 0 : totalreadcount +=copied;
257 0 : 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 : */
271 0 : static 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 0 : if (!gpt)
278 : return NULL;
279 :
280 0 : count = (size_t)le32_to_cpu(gpt->num_partition_entries) *
281 0 : le32_to_cpu(gpt->sizeof_partition_entry);
282 0 : if (!count)
283 : return NULL;
284 0 : pte = kmalloc(count, GFP_KERNEL);
285 0 : if (!pte)
286 : return NULL;
287 :
288 0 : if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
289 : (u8 *) pte, count) < count) {
290 0 : kfree(pte);
291 0 : pte=NULL;
292 0 : 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 : */
306 0 : static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
307 : u64 lba)
308 : {
309 : gpt_header *gpt;
310 0 : unsigned ssz = queue_logical_block_size(state->disk->queue);
311 :
312 0 : gpt = kmalloc(ssz, GFP_KERNEL);
313 0 : if (!gpt)
314 : return NULL;
315 :
316 0 : if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
317 0 : kfree(gpt);
318 0 : gpt=NULL;
319 0 : 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 : */
335 0 : static 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 0 : if (!ptes)
342 : return 0;
343 0 : if (!(*gpt = alloc_read_gpt_header(state, lba)))
344 : return 0;
345 :
346 : /* Check the GUID Partition Table signature */
347 0 : 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 0 : if (le32_to_cpu((*gpt)->header_size) >
357 0 : 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 0 : 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 0 : origcrc = le32_to_cpu((*gpt)->header_crc32);
374 0 : (*gpt)->header_crc32 = 0;
375 0 : crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
376 :
377 0 : if (crc != origcrc) {
378 : pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
379 : crc, origcrc);
380 : goto fail;
381 : }
382 0 : (*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 0 : 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 0 : lastlba = last_lba(state->disk);
397 0 : 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 0 : 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 0 : 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 0 : 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 0 : pt_size = (u64)le32_to_cpu((*gpt)->num_partition_entries) *
423 0 : le32_to_cpu((*gpt)->sizeof_partition_entry);
424 0 : 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 0 : if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
431 : goto fail;
432 :
433 : /* Check the GUID Partition Entry Array CRC */
434 0 : crc = efi_crc32((const unsigned char *) (*ptes), pt_size);
435 :
436 0 : 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 0 : kfree(*ptes);
446 0 : *ptes = NULL;
447 : fail:
448 0 : kfree(*gpt);
449 0 : *gpt = NULL;
450 0 : 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 : */
460 : static inline int
461 0 : is_pte_valid(const gpt_entry *pte, const u64 lastlba)
462 : {
463 0 : if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
464 0 : le64_to_cpu(pte->starting_lba) > lastlba ||
465 0 : le64_to_cpu(pte->ending_lba) > lastlba)
466 : return 0;
467 0 : 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 : */
480 : static void
481 0 : compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
482 : {
483 0 : int error_found = 0;
484 0 : if (!pgpt || !agpt)
485 : return;
486 0 : if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
487 0 : pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n");
488 0 : 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 0 : error_found++;
492 : }
493 0 : if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
494 0 : pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n");
495 0 : 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 0 : error_found++;
499 : }
500 0 : if (le64_to_cpu(pgpt->first_usable_lba) !=
501 0 : le64_to_cpu(agpt->first_usable_lba)) {
502 0 : pr_warn("GPT:first_usable_lbas don't match.\n");
503 0 : 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 0 : error_found++;
507 : }
508 0 : if (le64_to_cpu(pgpt->last_usable_lba) !=
509 0 : le64_to_cpu(agpt->last_usable_lba)) {
510 0 : pr_warn("GPT:last_usable_lbas don't match.\n");
511 0 : 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 0 : error_found++;
515 : }
516 0 : if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
517 0 : pr_warn("GPT:disk_guids don't match.\n");
518 0 : error_found++;
519 : }
520 0 : if (le32_to_cpu(pgpt->num_partition_entries) !=
521 0 : le32_to_cpu(agpt->num_partition_entries)) {
522 0 : 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 0 : error_found++;
527 : }
528 0 : if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
529 0 : le32_to_cpu(agpt->sizeof_partition_entry)) {
530 0 : 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 0 : error_found++;
535 : }
536 0 : if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
537 0 : le32_to_cpu(agpt->partition_entry_array_crc32)) {
538 0 : 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 0 : error_found++;
543 : }
544 0 : if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
545 0 : pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
546 0 : pr_warn("GPT:%lld != %lld\n",
547 : (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
548 : (unsigned long long)lastlba);
549 0 : error_found++;
550 : }
551 :
552 0 : if (le64_to_cpu(agpt->my_lba) != lastlba) {
553 0 : pr_warn("GPT:Alternate GPT header not at the end of the disk.\n");
554 0 : pr_warn("GPT:%lld != %lld\n",
555 : (unsigned long long)le64_to_cpu(agpt->my_lba),
556 : (unsigned long long)lastlba);
557 0 : error_found++;
558 : }
559 :
560 0 : if (error_found)
561 0 : 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 : */
581 0 : static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
582 : gpt_entry **ptes)
583 : {
584 0 : int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
585 0 : gpt_header *pgpt = NULL, *agpt = NULL;
586 0 : gpt_entry *pptes = NULL, *aptes = NULL;
587 : legacy_mbr *legacymbr;
588 0 : struct gendisk *disk = state->disk;
589 0 : const struct block_device_operations *fops = disk->fops;
590 0 : sector_t total_sectors = get_capacity(state->disk);
591 : u64 lastlba;
592 :
593 0 : if (!ptes)
594 : return 0;
595 :
596 0 : lastlba = last_lba(state->disk);
597 0 : if (!force_gpt) {
598 : /* This will be added to the EFI Spec. per Intel after v1.02. */
599 0 : legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL);
600 0 : if (!legacymbr)
601 : goto fail;
602 :
603 0 : read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr));
604 0 : good_pmbr = is_pmbr_valid(legacymbr, total_sectors);
605 0 : kfree(legacymbr);
606 :
607 0 : 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 0 : good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
616 : &pgpt, &pptes);
617 0 : if (good_pgpt)
618 0 : good_agpt = is_gpt_valid(state,
619 0 : le64_to_cpu(pgpt->alternate_lba),
620 : &agpt, &aptes);
621 0 : if (!good_agpt && force_gpt)
622 0 : good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
623 :
624 0 : if (!good_agpt && force_gpt && fops->alternative_gpt_sector) {
625 : sector_t agpt_sector;
626 : int err;
627 :
628 0 : err = fops->alternative_gpt_sector(disk, &agpt_sector);
629 0 : if (!err)
630 0 : good_agpt = is_gpt_valid(state, agpt_sector,
631 : &agpt, &aptes);
632 : }
633 :
634 : /* The obviously unsuccessful case */
635 0 : if (!good_pgpt && !good_agpt)
636 : goto fail;
637 :
638 0 : compare_gpts(pgpt, agpt, lastlba);
639 :
640 : /* The good cases */
641 0 : if (good_pgpt) {
642 0 : *gpt = pgpt;
643 0 : *ptes = pptes;
644 0 : kfree(agpt);
645 0 : kfree(aptes);
646 0 : if (!good_agpt)
647 0 : pr_warn("Alternate GPT is invalid, using primary GPT.\n");
648 : return 1;
649 : }
650 0 : else if (good_agpt) {
651 0 : *gpt = agpt;
652 0 : *ptes = aptes;
653 0 : kfree(pgpt);
654 0 : kfree(pptes);
655 0 : pr_warn("Primary GPT is invalid, using alternate GPT.\n");
656 0 : return 1;
657 : }
658 :
659 : fail:
660 0 : kfree(pgpt);
661 0 : kfree(agpt);
662 0 : kfree(pptes);
663 0 : kfree(aptes);
664 0 : *gpt = NULL;
665 0 : *ptes = NULL;
666 0 : 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 : */
678 : static void utf16_le_to_7bit(const __le16 *in, unsigned int size, u8 *out)
679 : {
680 0 : unsigned int i = 0;
681 :
682 0 : out[size] = 0;
683 :
684 0 : while (i < size) {
685 0 : u8 c = le16_to_cpu(in[i]) & 0xff;
686 :
687 0 : if (c && !isprint(c))
688 0 : c = '!';
689 0 : out[i] = c;
690 0 : 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 : */
713 0 : int efi_partition(struct parsed_partitions *state)
714 : {
715 0 : gpt_header *gpt = NULL;
716 0 : gpt_entry *ptes = NULL;
717 : u32 i;
718 0 : unsigned ssz = queue_logical_block_size(state->disk->queue) / 512;
719 :
720 0 : if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
721 0 : kfree(gpt);
722 0 : kfree(ptes);
723 0 : return 0;
724 : }
725 :
726 : pr_debug("GUID Partition Table is valid! Yea!\n");
727 :
728 0 : 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 0 : u64 start = le64_to_cpu(ptes[i].starting_lba);
732 0 : u64 size = le64_to_cpu(ptes[i].ending_lba) -
733 : le64_to_cpu(ptes[i].starting_lba) + 1ULL;
734 :
735 0 : if (!is_pte_valid(&ptes[i], last_lba(state->disk)))
736 0 : continue;
737 :
738 0 : put_partition(state, i+1, start * ssz, size * ssz);
739 :
740 : /* If this is a RAID volume, tell md */
741 0 : if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID))
742 0 : state->parts[i + 1].flags = ADDPART_FLAG_RAID;
743 :
744 0 : info = &state->parts[i + 1].info;
745 0 : efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid);
746 :
747 : /* Naively convert UTF16-LE to 7 bits. */
748 0 : label_max = min(ARRAY_SIZE(info->volname) - 1,
749 : ARRAY_SIZE(ptes[i].partition_name));
750 0 : utf16_le_to_7bit(ptes[i].partition_name, label_max, info->volname);
751 0 : state->parts[i + 1].has_info = true;
752 : }
753 0 : kfree(ptes);
754 0 : kfree(gpt);
755 0 : strlcat(state->pp_buf, "\n", PAGE_SIZE);
756 0 : return 1;
757 : }
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