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 | * @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 | return div_u64(dividend: bdev_nr_bytes(bdev: disk->part0), |
137 | divisor: queue_logical_block_size(q: disk->queue)) - 1ULL; |
138 | } |
139 | |
140 | static 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; |
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 | static 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(part: &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; |
195 | check_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 | } |
221 | done: |
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 | */ |
235 | static 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(q: state->disk->queue) / 512); |
241 | |
242 | if (!buffer || lba > last_lba(disk: 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: n++, p: §); |
249 | if (!data) |
250 | break; |
251 | if (copied > count) |
252 | copied = count; |
253 | memcpy(buffer, data, copied); |
254 | put_dev_sector(p: 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 | */ |
271 | 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 | 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(size: count, GFP_KERNEL); |
285 | if (!pte) |
286 | return NULL; |
287 | |
288 | if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba), |
289 | buffer: (u8 *) pte, count) < count) { |
290 | kfree(objp: 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 | */ |
306 | static gpt_header *(struct parsed_partitions *state, |
307 | u64 lba) |
308 | { |
309 | gpt_header *gpt; |
310 | unsigned ssz = queue_logical_block_size(q: state->disk->queue); |
311 | |
312 | gpt = kmalloc(size: ssz, GFP_KERNEL); |
313 | if (!gpt) |
314 | return NULL; |
315 | |
316 | if (read_lba(state, lba, buffer: (u8 *) gpt, count: ssz) < ssz) { |
317 | kfree(objp: 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 | */ |
335 | 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 | 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(q: 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(buf: (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(disk: 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: *gpt))) |
431 | goto fail; |
432 | |
433 | /* Check the GUID Partition Entry Array CRC */ |
434 | crc = efi_crc32(buf: (const unsigned char *) (*ptes), len: 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(objp: *ptes); |
446 | *ptes = NULL; |
447 | fail: |
448 | kfree(objp: *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 | */ |
460 | static inline int |
461 | is_pte_valid(const gpt_entry *pte, const u64 lastlba) |
462 | { |
463 | if ((!efi_guidcmp(left: 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 | */ |
480 | static void |
481 | compare_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(left: pgpt->disk_guid, right: 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 | */ |
581 | static 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(disk: state->disk); |
591 | u64 lastlba; |
592 | |
593 | if (!ptes) |
594 | return 0; |
595 | |
596 | lastlba = last_lba(disk: state->disk); |
597 | if (!force_gpt) { |
598 | /* This will be added to the EFI Spec. per Intel after v1.02. */ |
599 | legacymbr = kzalloc(size: sizeof(*legacymbr), GFP_KERNEL); |
600 | if (!legacymbr) |
601 | goto fail; |
602 | |
603 | read_lba(state, lba: 0, buffer: (u8 *)legacymbr, count: sizeof(*legacymbr)); |
604 | good_pmbr = is_pmbr_valid(mbr: legacymbr, total_sectors); |
605 | kfree(objp: 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 | gpt: &pgpt, ptes: &pptes); |
617 | if (good_pgpt) |
618 | good_agpt = is_gpt_valid(state, |
619 | le64_to_cpu(pgpt->alternate_lba), |
620 | gpt: &agpt, ptes: &aptes); |
621 | if (!good_agpt && force_gpt) |
622 | good_agpt = is_gpt_valid(state, lba: lastlba, gpt: &agpt, ptes: &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, lba: agpt_sector, |
631 | gpt: &agpt, ptes: &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(objp: agpt); |
645 | kfree(objp: 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(objp: pgpt); |
654 | kfree(objp: pptes); |
655 | pr_warn("Primary GPT is invalid, using alternate GPT.\n" ); |
656 | return 1; |
657 | } |
658 | |
659 | fail: |
660 | kfree(objp: pgpt); |
661 | kfree(objp: agpt); |
662 | kfree(objp: pptes); |
663 | kfree(objp: 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 | */ |
678 | static 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]) & 0xff; |
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 | */ |
713 | int 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(q: state->disk->queue) / 512; |
719 | |
720 | if (!find_valid_gpt(state, gpt: &gpt, ptes: &ptes) || !gpt || !ptes) { |
721 | kfree(objp: gpt); |
722 | kfree(objp: 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(pte: &ptes[i], lastlba: last_lba(disk: state->disk))) |
736 | continue; |
737 | |
738 | put_partition(p: state, n: i+1, from: start * ssz, size: size * ssz); |
739 | |
740 | /* If this is a RAID volume, tell md */ |
741 | if (!efi_guidcmp(left: 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(guid: &ptes[i].unique_partition_guid, out: 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(in: ptes[i].partition_name, size: label_max, out: info->volname); |
751 | state->parts[i + 1].has_info = true; |
752 | } |
753 | kfree(objp: ptes); |
754 | kfree(objp: gpt); |
755 | strlcat(p: state->pp_buf, q: "\n" , PAGE_SIZE); |
756 | return 1; |
757 | } |
758 | |