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94#include <linux/crc32.h>
95#include "check.h"
96#include "efi.h"
97
98
99
100
101
102static int force_gpt;
103static int __init
104force_gpt_fn(char *str)
105{
106 force_gpt = 1;
107 return 1;
108}
109__setup("gpt", force_gpt_fn);
110
111
112
113
114
115
116
117
118
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120
121
122
123
124static inline u32
125efi_crc32(const void *buf, unsigned long len)
126{
127 return (crc32(~0L, buf, len) ^ ~0L);
128}
129
130
131
132
133
134
135
136
137
138
139static u64
140last_lba(struct block_device *bdev)
141{
142 if (!bdev || !bdev->bd_inode)
143 return 0;
144 return (bdev->bd_inode->i_size >> 9) - 1ULL;
145}
146
147static inline int
148pmbr_part_valid(struct partition *part)
149{
150 if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
151 le32_to_cpu(part->start_sect) == 1UL)
152 return 1;
153 return 0;
154}
155
156
157
158
159
160
161
162
163
164
165static int
166is_pmbr_valid(legacy_mbr *mbr)
167{
168 int i;
169 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
170 return 0;
171 for (i = 0; i < 4; i++)
172 if (pmbr_part_valid(&mbr->partition_record[i]))
173 return 1;
174 return 0;
175}
176
177
178
179
180
181
182
183
184
185
186
187static size_t
188read_lba(struct block_device *bdev, u64 lba, u8 * buffer, size_t count)
189{
190 size_t totalreadcount = 0;
191
192 if (!bdev || !buffer || lba > last_lba(bdev))
193 return 0;
194
195 while (count) {
196 int copied = 512;
197 Sector sect;
198 unsigned char *data = read_dev_sector(bdev, lba++, §);
199 if (!data)
200 break;
201 if (copied > count)
202 copied = count;
203 memcpy(buffer, data, copied);
204 put_dev_sector(sect);
205 buffer += copied;
206 totalreadcount +=copied;
207 count -= copied;
208 }
209 return totalreadcount;
210}
211
212
213
214
215
216
217
218
219
220
221static gpt_entry *
222alloc_read_gpt_entries(struct block_device *bdev, gpt_header *gpt)
223{
224 size_t count;
225 gpt_entry *pte;
226 if (!bdev || !gpt)
227 return NULL;
228
229 count = le32_to_cpu(gpt->num_partition_entries) *
230 le32_to_cpu(gpt->sizeof_partition_entry);
231 if (!count)
232 return NULL;
233 pte = kzalloc(count, GFP_KERNEL);
234 if (!pte)
235 return NULL;
236
237 if (read_lba(bdev, le64_to_cpu(gpt->partition_entry_lba),
238 (u8 *) pte,
239 count) < count) {
240 kfree(pte);
241 pte=NULL;
242 return NULL;
243 }
244 return pte;
245}
246
247
248
249
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251
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253
254
255
256static gpt_header *
257alloc_read_gpt_header(struct block_device *bdev, u64 lba)
258{
259 gpt_header *gpt;
260 if (!bdev)
261 return NULL;
262
263 gpt = kzalloc(sizeof (gpt_header), GFP_KERNEL);
264 if (!gpt)
265 return NULL;
266
267 if (read_lba(bdev, lba, (u8 *) gpt,
268 sizeof (gpt_header)) < sizeof (gpt_header)) {
269 kfree(gpt);
270 gpt=NULL;
271 return NULL;
272 }
273
274 return gpt;
275}
276
277
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281
282
283
284
285
286
287static int
288is_gpt_valid(struct block_device *bdev, u64 lba,
289 gpt_header **gpt, gpt_entry **ptes)
290{
291 u32 crc, origcrc;
292 u64 lastlba;
293
294 if (!bdev || !gpt || !ptes)
295 return 0;
296 if (!(*gpt = alloc_read_gpt_header(bdev, lba)))
297 return 0;
298
299
300 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
301 pr_debug("GUID Partition Table Header signature is wrong:"
302 "%lld != %lld\n",
303 (unsigned long long)le64_to_cpu((*gpt)->signature),
304 (unsigned long long)GPT_HEADER_SIGNATURE);
305 goto fail;
306 }
307
308
309 origcrc = le32_to_cpu((*gpt)->header_crc32);
310 (*gpt)->header_crc32 = 0;
311 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
312
313 if (crc != origcrc) {
314 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
315 crc, origcrc);
316 goto fail;
317 }
318 (*gpt)->header_crc32 = cpu_to_le32(origcrc);
319
320
321
322 if (le64_to_cpu((*gpt)->my_lba) != lba) {
323 pr_debug("GPT my_lba incorrect: %lld != %lld\n",
324 (unsigned long long)le64_to_cpu((*gpt)->my_lba),
325 (unsigned long long)lba);
326 goto fail;
327 }
328
329
330
331
332 lastlba = last_lba(bdev);
333 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
334 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
335 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
336 (unsigned long long)lastlba);
337 goto fail;
338 }
339 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
340 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
341 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
342 (unsigned long long)lastlba);
343 goto fail;
344 }
345
346 if (!(*ptes = alloc_read_gpt_entries(bdev, *gpt)))
347 goto fail;
348
349
350 crc = efi_crc32((const unsigned char *) (*ptes),
351 le32_to_cpu((*gpt)->num_partition_entries) *
352 le32_to_cpu((*gpt)->sizeof_partition_entry));
353
354 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
355 pr_debug("GUID Partitition Entry Array CRC check failed.\n");
356 goto fail_ptes;
357 }
358
359
360 return 1;
361
362 fail_ptes:
363 kfree(*ptes);
364 *ptes = NULL;
365 fail:
366 kfree(*gpt);
367 *gpt = NULL;
368 return 0;
369}
370
371
372
373
374
375
376
377
378static inline int
379is_pte_valid(const gpt_entry *pte, const u64 lastlba)
380{
381 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
382 le64_to_cpu(pte->starting_lba) > lastlba ||
383 le64_to_cpu(pte->ending_lba) > lastlba)
384 return 0;
385 return 1;
386}
387
388
389
390
391
392
393
394
395
396
397static void
398compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
399{
400 int error_found = 0;
401 if (!pgpt || !agpt)
402 return;
403 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
404 printk(KERN_WARNING
405 "GPT:Primary header LBA != Alt. header alternate_lba\n");
406 printk(KERN_WARNING "GPT:%lld != %lld\n",
407 (unsigned long long)le64_to_cpu(pgpt->my_lba),
408 (unsigned long long)le64_to_cpu(agpt->alternate_lba));
409 error_found++;
410 }
411 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
412 printk(KERN_WARNING
413 "GPT:Primary header alternate_lba != Alt. header my_lba\n");
414 printk(KERN_WARNING "GPT:%lld != %lld\n",
415 (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
416 (unsigned long long)le64_to_cpu(agpt->my_lba));
417 error_found++;
418 }
419 if (le64_to_cpu(pgpt->first_usable_lba) !=
420 le64_to_cpu(agpt->first_usable_lba)) {
421 printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n");
422 printk(KERN_WARNING "GPT:%lld != %lld\n",
423 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
424 (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
425 error_found++;
426 }
427 if (le64_to_cpu(pgpt->last_usable_lba) !=
428 le64_to_cpu(agpt->last_usable_lba)) {
429 printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n");
430 printk(KERN_WARNING "GPT:%lld != %lld\n",
431 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
432 (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
433 error_found++;
434 }
435 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
436 printk(KERN_WARNING "GPT:disk_guids don't match.\n");
437 error_found++;
438 }
439 if (le32_to_cpu(pgpt->num_partition_entries) !=
440 le32_to_cpu(agpt->num_partition_entries)) {
441 printk(KERN_WARNING "GPT:num_partition_entries don't match: "
442 "0x%x != 0x%x\n",
443 le32_to_cpu(pgpt->num_partition_entries),
444 le32_to_cpu(agpt->num_partition_entries));
445 error_found++;
446 }
447 if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
448 le32_to_cpu(agpt->sizeof_partition_entry)) {
449 printk(KERN_WARNING
450 "GPT:sizeof_partition_entry values don't match: "
451 "0x%x != 0x%x\n",
452 le32_to_cpu(pgpt->sizeof_partition_entry),
453 le32_to_cpu(agpt->sizeof_partition_entry));
454 error_found++;
455 }
456 if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
457 le32_to_cpu(agpt->partition_entry_array_crc32)) {
458 printk(KERN_WARNING
459 "GPT:partition_entry_array_crc32 values don't match: "
460 "0x%x != 0x%x\n",
461 le32_to_cpu(pgpt->partition_entry_array_crc32),
462 le32_to_cpu(agpt->partition_entry_array_crc32));
463 error_found++;
464 }
465 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
466 printk(KERN_WARNING
467 "GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
468 printk(KERN_WARNING "GPT:%lld != %lld\n",
469 (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
470 (unsigned long long)lastlba);
471 error_found++;
472 }
473
474 if (le64_to_cpu(agpt->my_lba) != lastlba) {
475 printk(KERN_WARNING
476 "GPT:Alternate GPT header not at the end of the disk.\n");
477 printk(KERN_WARNING "GPT:%lld != %lld\n",
478 (unsigned long long)le64_to_cpu(agpt->my_lba),
479 (unsigned long long)lastlba);
480 error_found++;
481 }
482
483 if (error_found)
484 printk(KERN_WARNING
485 "GPT: Use GNU Parted to correct GPT errors.\n");
486 return;
487}
488
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501
502
503
504static int
505find_valid_gpt(struct block_device *bdev, gpt_header **gpt, gpt_entry **ptes)
506{
507 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
508 gpt_header *pgpt = NULL, *agpt = NULL;
509 gpt_entry *pptes = NULL, *aptes = NULL;
510 legacy_mbr *legacymbr;
511 u64 lastlba;
512 if (!bdev || !gpt || !ptes)
513 return 0;
514
515 lastlba = last_lba(bdev);
516 if (!force_gpt) {
517
518 legacymbr = kzalloc(sizeof (*legacymbr), GFP_KERNEL);
519 if (legacymbr) {
520 read_lba(bdev, 0, (u8 *) legacymbr,
521 sizeof (*legacymbr));
522 good_pmbr = is_pmbr_valid(legacymbr);
523 kfree(legacymbr);
524 }
525 if (!good_pmbr)
526 goto fail;
527 }
528
529 good_pgpt = is_gpt_valid(bdev, GPT_PRIMARY_PARTITION_TABLE_LBA,
530 &pgpt, &pptes);
531 if (good_pgpt)
532 good_agpt = is_gpt_valid(bdev,
533 le64_to_cpu(pgpt->alternate_lba),
534 &agpt, &aptes);
535 if (!good_agpt && force_gpt)
536 good_agpt = is_gpt_valid(bdev, lastlba,
537 &agpt, &aptes);
538
539
540 if (!good_pgpt && !good_agpt)
541 goto fail;
542
543 compare_gpts(pgpt, agpt, lastlba);
544
545
546 if (good_pgpt) {
547 *gpt = pgpt;
548 *ptes = pptes;
549 kfree(agpt);
550 kfree(aptes);
551 if (!good_agpt) {
552 printk(KERN_WARNING
553 "Alternate GPT is invalid, "
554 "using primary GPT.\n");
555 }
556 return 1;
557 }
558 else if (good_agpt) {
559 *gpt = agpt;
560 *ptes = aptes;
561 kfree(pgpt);
562 kfree(pptes);
563 printk(KERN_WARNING
564 "Primary GPT is invalid, using alternate GPT.\n");
565 return 1;
566 }
567
568 fail:
569 kfree(pgpt);
570 kfree(agpt);
571 kfree(pptes);
572 kfree(aptes);
573 *gpt = NULL;
574 *ptes = NULL;
575 return 0;
576}
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597
598int
599efi_partition(struct parsed_partitions *state, struct block_device *bdev)
600{
601 gpt_header *gpt = NULL;
602 gpt_entry *ptes = NULL;
603 u32 i;
604
605 if (!find_valid_gpt(bdev, &gpt, &ptes) || !gpt || !ptes) {
606 kfree(gpt);
607 kfree(ptes);
608 return 0;
609 }
610
611 pr_debug("GUID Partition Table is valid! Yea!\n");
612
613 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
614 if (!is_pte_valid(&ptes[i], last_lba(bdev)))
615 continue;
616
617 put_partition(state, i+1, le64_to_cpu(ptes[i].starting_lba),
618 (le64_to_cpu(ptes[i].ending_lba) -
619 le64_to_cpu(ptes[i].starting_lba) +
620 1ULL));
621
622
623 if (!efi_guidcmp(ptes[i].partition_type_guid,
624 PARTITION_LINUX_RAID_GUID))
625 state->parts[i+1].flags = 1;
626 }
627 kfree(ptes);
628 kfree(gpt);
629 printk("\n");
630 return 1;
631}
632