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1da177e4 LT |
1 | /************************************************************ |
2 | * EFI GUID Partition Table handling | |
7d13af32 KZ |
3 | * |
4 | * http://www.uefi.org/specs/ | |
5 | * http://www.intel.com/technology/efi/ | |
6 | * | |
1da177e4 LT |
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: | |
70f637e9 DB |
28 | * Mon August 5th, 2013 Davidlohr Bueso <davidlohr@hp.com> |
29 | * - detect hybrid MBRs, tighter pMBR checking & cleanups. | |
30 | * | |
1da177e4 LT |
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 | ************************************************************/ | |
1da177e4 | 99 | #include <linux/crc32.h> |
eec7ecfe | 100 | #include <linux/ctype.h> |
7d13af32 | 101 | #include <linux/math64.h> |
5a0e3ad6 | 102 | #include <linux/slab.h> |
1da177e4 LT |
103 | #include "check.h" |
104 | #include "efi.h" | |
105 | ||
1da177e4 LT |
106 | /* This allows a kernel command line option 'gpt' to override |
107 | * the test for invalid PMBR. Not __initdata because reloading | |
108 | * the partition tables happens after init too. | |
109 | */ | |
110 | static int force_gpt; | |
111 | static int __init | |
112 | force_gpt_fn(char *str) | |
113 | { | |
114 | force_gpt = 1; | |
115 | return 1; | |
116 | } | |
117 | __setup("gpt", force_gpt_fn); | |
118 | ||
119 | ||
120 | /** | |
121 | * efi_crc32() - EFI version of crc32 function | |
122 | * @buf: buffer to calculate crc32 of | |
123 | * @len - length of buf | |
124 | * | |
125 | * Description: Returns EFI-style CRC32 value for @buf | |
126 | * | |
127 | * This function uses the little endian Ethernet polynomial | |
128 | * but seeds the function with ~0, and xor's with ~0 at the end. | |
129 | * Note, the EFI Specification, v1.02, has a reference to | |
130 | * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). | |
131 | */ | |
132 | static inline u32 | |
133 | efi_crc32(const void *buf, unsigned long len) | |
134 | { | |
135 | return (crc32(~0L, buf, len) ^ ~0L); | |
136 | } | |
137 | ||
138 | /** | |
139 | * last_lba(): return number of last logical block of device | |
140 | * @bdev: block device | |
141 | * | |
142 | * Description: Returns last LBA value on success, 0 on error. | |
143 | * This is stored (by sd and ide-geometry) in | |
144 | * the part[0] entry for this disk, and is the number of | |
145 | * physical sectors available on the disk. | |
146 | */ | |
1493bf21 | 147 | static u64 last_lba(struct block_device *bdev) |
1da177e4 LT |
148 | { |
149 | if (!bdev || !bdev->bd_inode) | |
150 | return 0; | |
7d13af32 KZ |
151 | return div_u64(bdev->bd_inode->i_size, |
152 | bdev_logical_block_size(bdev)) - 1ULL; | |
1da177e4 LT |
153 | } |
154 | ||
c2ebdc24 | 155 | static inline int pmbr_part_valid(gpt_mbr_record *part) |
1da177e4 | 156 | { |
33afd7a7 DB |
157 | if (part->os_type != EFI_PMBR_OSTYPE_EFI_GPT) |
158 | goto invalid; | |
159 | ||
160 | /* set to 0x00000001 (i.e., the LBA of the GPT Partition Header) */ | |
161 | if (le32_to_cpu(part->starting_lba) != GPT_PRIMARY_PARTITION_TABLE_LBA) | |
162 | goto invalid; | |
163 | ||
b05ebbbb | 164 | return GPT_MBR_PROTECTIVE; |
33afd7a7 DB |
165 | invalid: |
166 | return 0; | |
1da177e4 LT |
167 | } |
168 | ||
169 | /** | |
170 | * is_pmbr_valid(): test Protective MBR for validity | |
171 | * @mbr: pointer to a legacy mbr structure | |
27a7c642 | 172 | * @total_sectors: amount of sectors in the device |
1da177e4 | 173 | * |
b05ebbbb DB |
174 | * Description: Checks for a valid protective or hybrid |
175 | * master boot record (MBR). The validity of a pMBR depends | |
176 | * on all of the following properties: | |
1da177e4 LT |
177 | * 1) MSDOS signature is in the last two bytes of the MBR |
178 | * 2) One partition of type 0xEE is found | |
b05ebbbb DB |
179 | * |
180 | * In addition, a hybrid MBR will have up to three additional | |
181 | * primary partitions, which point to the same space that's | |
182 | * marked out by up to three GPT partitions. | |
183 | * | |
184 | * Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or | |
185 | * GPT_MBR_HYBRID depending on the device layout. | |
1da177e4 | 186 | */ |
27a7c642 | 187 | static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors) |
1da177e4 | 188 | { |
6b02fa59 | 189 | uint32_t sz = 0; |
27a7c642 | 190 | int i, part = 0, ret = 0; /* invalid by default */ |
b05ebbbb | 191 | |
1da177e4 | 192 | if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE) |
b05ebbbb DB |
193 | goto done; |
194 | ||
195 | for (i = 0; i < 4; i++) { | |
196 | ret = pmbr_part_valid(&mbr->partition_record[i]); | |
197 | if (ret == GPT_MBR_PROTECTIVE) { | |
27a7c642 | 198 | part = i; |
b05ebbbb DB |
199 | /* |
200 | * Ok, we at least know that there's a protective MBR, | |
201 | * now check if there are other partition types for | |
202 | * hybrid MBR. | |
203 | */ | |
204 | goto check_hybrid; | |
205 | } | |
206 | } | |
207 | ||
208 | if (ret != GPT_MBR_PROTECTIVE) | |
209 | goto done; | |
210 | check_hybrid: | |
1da177e4 | 211 | for (i = 0; i < 4; i++) |
b05ebbbb DB |
212 | if ((mbr->partition_record[i].os_type != |
213 | EFI_PMBR_OSTYPE_EFI_GPT) && | |
214 | (mbr->partition_record[i].os_type != 0x00)) | |
215 | ret = GPT_MBR_HYBRID; | |
27a7c642 DB |
216 | |
217 | /* | |
218 | * Protective MBRs take up the lesser of the whole disk | |
219 | * or 2 TiB (32bit LBA), ignoring the rest of the disk. | |
6b02fa59 DB |
220 | * Some partitioning programs, nonetheless, choose to set |
221 | * the size to the maximum 32-bit limitation, disregarding | |
222 | * the disk size. | |
27a7c642 DB |
223 | * |
224 | * Hybrid MBRs do not necessarily comply with this. | |
87fc0ad2 DA |
225 | * |
226 | * Consider a bad value here to be a warning to support dd'ing | |
227 | * an image from a smaller disk to a larger disk. | |
27a7c642 DB |
228 | */ |
229 | if (ret == GPT_MBR_PROTECTIVE) { | |
6b02fa59 DB |
230 | sz = le32_to_cpu(mbr->partition_record[part].size_in_lba); |
231 | if (sz != (uint32_t) total_sectors - 1 && sz != 0xFFFFFFFF) | |
87fc0ad2 DA |
232 | pr_debug("GPT: mbr size in lba (%u) different than whole disk (%u).\n", |
233 | sz, min_t(uint32_t, | |
234 | total_sectors - 1, 0xFFFFFFFF)); | |
27a7c642 | 235 | } |
b05ebbbb DB |
236 | done: |
237 | return ret; | |
1da177e4 LT |
238 | } |
239 | ||
240 | /** | |
241 | * read_lba(): Read bytes from disk, starting at given LBA | |
1493bf21 | 242 | * @state |
1da177e4 LT |
243 | * @lba |
244 | * @buffer | |
245 | * @size_t | |
246 | * | |
1493bf21 | 247 | * Description: Reads @count bytes from @state->bdev into @buffer. |
1da177e4 LT |
248 | * Returns number of bytes read on success, 0 on error. |
249 | */ | |
1493bf21 TH |
250 | static size_t read_lba(struct parsed_partitions *state, |
251 | u64 lba, u8 *buffer, size_t count) | |
1da177e4 LT |
252 | { |
253 | size_t totalreadcount = 0; | |
1493bf21 | 254 | struct block_device *bdev = state->bdev; |
7d13af32 | 255 | sector_t n = lba * (bdev_logical_block_size(bdev) / 512); |
1da177e4 | 256 | |
1493bf21 | 257 | if (!buffer || lba > last_lba(bdev)) |
1da177e4 LT |
258 | return 0; |
259 | ||
260 | while (count) { | |
261 | int copied = 512; | |
262 | Sector sect; | |
1493bf21 | 263 | unsigned char *data = read_part_sector(state, n++, §); |
1da177e4 LT |
264 | if (!data) |
265 | break; | |
266 | if (copied > count) | |
267 | copied = count; | |
268 | memcpy(buffer, data, copied); | |
269 | put_dev_sector(sect); | |
270 | buffer += copied; | |
271 | totalreadcount +=copied; | |
272 | count -= copied; | |
273 | } | |
274 | return totalreadcount; | |
275 | } | |
276 | ||
277 | /** | |
278 | * alloc_read_gpt_entries(): reads partition entries from disk | |
1493bf21 | 279 | * @state |
1da177e4 LT |
280 | * @gpt - GPT header |
281 | * | |
282 | * Description: Returns ptes on success, NULL on error. | |
283 | * Allocates space for PTEs based on information found in @gpt. | |
284 | * Notes: remember to free pte when you're done! | |
285 | */ | |
1493bf21 TH |
286 | static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state, |
287 | gpt_header *gpt) | |
1da177e4 LT |
288 | { |
289 | size_t count; | |
290 | gpt_entry *pte; | |
1493bf21 TH |
291 | |
292 | if (!gpt) | |
1da177e4 LT |
293 | return NULL; |
294 | ||
295 | count = le32_to_cpu(gpt->num_partition_entries) * | |
296 | le32_to_cpu(gpt->sizeof_partition_entry); | |
297 | if (!count) | |
298 | return NULL; | |
ea56505b | 299 | pte = kmalloc(count, GFP_KERNEL); |
1da177e4 LT |
300 | if (!pte) |
301 | return NULL; | |
1da177e4 | 302 | |
1493bf21 | 303 | if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba), |
70f637e9 | 304 | (u8 *) pte, count) < count) { |
1da177e4 LT |
305 | kfree(pte); |
306 | pte=NULL; | |
307 | return NULL; | |
308 | } | |
309 | return pte; | |
310 | } | |
311 | ||
312 | /** | |
313 | * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk | |
1493bf21 | 314 | * @state |
1da177e4 LT |
315 | * @lba is the Logical Block Address of the partition table |
316 | * | |
317 | * Description: returns GPT header on success, NULL on error. Allocates | |
1493bf21 | 318 | * and fills a GPT header starting at @ from @state->bdev. |
1da177e4 LT |
319 | * Note: remember to free gpt when finished with it. |
320 | */ | |
1493bf21 TH |
321 | static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state, |
322 | u64 lba) | |
1da177e4 LT |
323 | { |
324 | gpt_header *gpt; | |
1493bf21 | 325 | unsigned ssz = bdev_logical_block_size(state->bdev); |
1da177e4 | 326 | |
ea56505b | 327 | gpt = kmalloc(ssz, GFP_KERNEL); |
1da177e4 LT |
328 | if (!gpt) |
329 | return NULL; | |
1da177e4 | 330 | |
1493bf21 | 331 | if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) { |
1da177e4 LT |
332 | kfree(gpt); |
333 | gpt=NULL; | |
334 | return NULL; | |
335 | } | |
336 | ||
337 | return gpt; | |
338 | } | |
339 | ||
340 | /** | |
341 | * is_gpt_valid() - tests one GPT header and PTEs for validity | |
1493bf21 | 342 | * @state |
1da177e4 LT |
343 | * @lba is the logical block address of the GPT header to test |
344 | * @gpt is a GPT header ptr, filled on return. | |
345 | * @ptes is a PTEs ptr, filled on return. | |
346 | * | |
347 | * Description: returns 1 if valid, 0 on error. | |
348 | * If valid, returns pointers to newly allocated GPT header and PTEs. | |
349 | */ | |
1493bf21 TH |
350 | static int is_gpt_valid(struct parsed_partitions *state, u64 lba, |
351 | gpt_header **gpt, gpt_entry **ptes) | |
1da177e4 LT |
352 | { |
353 | u32 crc, origcrc; | |
354 | u64 lastlba; | |
355 | ||
1493bf21 | 356 | if (!ptes) |
1da177e4 | 357 | return 0; |
1493bf21 | 358 | if (!(*gpt = alloc_read_gpt_header(state, lba))) |
1da177e4 LT |
359 | return 0; |
360 | ||
361 | /* Check the GUID Partition Table signature */ | |
362 | if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { | |
d9916962 TG |
363 | pr_debug("GUID Partition Table Header signature is wrong:" |
364 | "%lld != %lld\n", | |
365 | (unsigned long long)le64_to_cpu((*gpt)->signature), | |
366 | (unsigned long long)GPT_HEADER_SIGNATURE); | |
1da177e4 LT |
367 | goto fail; |
368 | } | |
369 | ||
8b8a6e18 | 370 | /* Check the GUID Partition Table header size is too big */ |
3eb8e74e TW |
371 | if (le32_to_cpu((*gpt)->header_size) > |
372 | bdev_logical_block_size(state->bdev)) { | |
8b8a6e18 | 373 | pr_debug("GUID Partition Table Header size is too large: %u > %u\n", |
3eb8e74e TW |
374 | le32_to_cpu((*gpt)->header_size), |
375 | bdev_logical_block_size(state->bdev)); | |
376 | goto fail; | |
377 | } | |
378 | ||
8b8a6e18 PJ |
379 | /* Check the GUID Partition Table header size is too small */ |
380 | if (le32_to_cpu((*gpt)->header_size) < sizeof(gpt_header)) { | |
381 | pr_debug("GUID Partition Table Header size is too small: %u < %zu\n", | |
382 | le32_to_cpu((*gpt)->header_size), | |
383 | sizeof(gpt_header)); | |
384 | goto fail; | |
385 | } | |
386 | ||
1da177e4 LT |
387 | /* Check the GUID Partition Table CRC */ |
388 | origcrc = le32_to_cpu((*gpt)->header_crc32); | |
389 | (*gpt)->header_crc32 = 0; | |
390 | crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); | |
391 | ||
392 | if (crc != origcrc) { | |
d9916962 TG |
393 | pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n", |
394 | crc, origcrc); | |
1da177e4 LT |
395 | goto fail; |
396 | } | |
397 | (*gpt)->header_crc32 = cpu_to_le32(origcrc); | |
398 | ||
399 | /* Check that the my_lba entry points to the LBA that contains | |
400 | * the GUID Partition Table */ | |
401 | if (le64_to_cpu((*gpt)->my_lba) != lba) { | |
d9916962 TG |
402 | pr_debug("GPT my_lba incorrect: %lld != %lld\n", |
403 | (unsigned long long)le64_to_cpu((*gpt)->my_lba), | |
404 | (unsigned long long)lba); | |
1da177e4 LT |
405 | goto fail; |
406 | } | |
407 | ||
408 | /* Check the first_usable_lba and last_usable_lba are | |
409 | * within the disk. | |
410 | */ | |
1493bf21 | 411 | lastlba = last_lba(state->bdev); |
1da177e4 | 412 | if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) { |
d9916962 TG |
413 | pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n", |
414 | (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba), | |
415 | (unsigned long long)lastlba); | |
1da177e4 LT |
416 | goto fail; |
417 | } | |
418 | if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) { | |
d9916962 TG |
419 | pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", |
420 | (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), | |
421 | (unsigned long long)lastlba); | |
1da177e4 LT |
422 | goto fail; |
423 | } | |
aa054bc9 DB |
424 | if (le64_to_cpu((*gpt)->last_usable_lba) < le64_to_cpu((*gpt)->first_usable_lba)) { |
425 | pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n", | |
426 | (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba), | |
427 | (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba)); | |
428 | goto fail; | |
429 | } | |
fa039d5f TW |
430 | /* Check that sizeof_partition_entry has the correct value */ |
431 | if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) { | |
432 | pr_debug("GUID Partitition Entry Size check failed.\n"); | |
433 | goto fail; | |
434 | } | |
435 | ||
1493bf21 | 436 | if (!(*ptes = alloc_read_gpt_entries(state, *gpt))) |
1da177e4 LT |
437 | goto fail; |
438 | ||
439 | /* Check the GUID Partition Entry Array CRC */ | |
440 | crc = efi_crc32((const unsigned char *) (*ptes), | |
441 | le32_to_cpu((*gpt)->num_partition_entries) * | |
442 | le32_to_cpu((*gpt)->sizeof_partition_entry)); | |
443 | ||
444 | if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { | |
d9916962 | 445 | pr_debug("GUID Partitition Entry Array CRC check failed.\n"); |
1da177e4 LT |
446 | goto fail_ptes; |
447 | } | |
448 | ||
449 | /* We're done, all's well */ | |
450 | return 1; | |
451 | ||
452 | fail_ptes: | |
453 | kfree(*ptes); | |
454 | *ptes = NULL; | |
455 | fail: | |
456 | kfree(*gpt); | |
457 | *gpt = NULL; | |
458 | return 0; | |
459 | } | |
460 | ||
461 | /** | |
462 | * is_pte_valid() - tests one PTE for validity | |
463 | * @pte is the pte to check | |
464 | * @lastlba is last lba of the disk | |
465 | * | |
466 | * Description: returns 1 if valid, 0 on error. | |
467 | */ | |
468 | static inline int | |
469 | is_pte_valid(const gpt_entry *pte, const u64 lastlba) | |
470 | { | |
471 | if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) || | |
472 | le64_to_cpu(pte->starting_lba) > lastlba || | |
473 | le64_to_cpu(pte->ending_lba) > lastlba) | |
474 | return 0; | |
475 | return 1; | |
476 | } | |
477 | ||
478 | /** | |
479 | * compare_gpts() - Search disk for valid GPT headers and PTEs | |
480 | * @pgpt is the primary GPT header | |
481 | * @agpt is the alternate GPT header | |
482 | * @lastlba is the last LBA number | |
483 | * Description: Returns nothing. Sanity checks pgpt and agpt fields | |
484 | * and prints warnings on discrepancies. | |
485 | * | |
486 | */ | |
487 | static void | |
488 | compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) | |
489 | { | |
490 | int error_found = 0; | |
491 | if (!pgpt || !agpt) | |
492 | return; | |
493 | if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { | |
b4bc4a18 AM |
494 | pr_warn("GPT:Primary header LBA != Alt. header alternate_lba\n"); |
495 | pr_warn("GPT:%lld != %lld\n", | |
1da177e4 LT |
496 | (unsigned long long)le64_to_cpu(pgpt->my_lba), |
497 | (unsigned long long)le64_to_cpu(agpt->alternate_lba)); | |
498 | error_found++; | |
499 | } | |
500 | if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { | |
b4bc4a18 AM |
501 | pr_warn("GPT:Primary header alternate_lba != Alt. header my_lba\n"); |
502 | pr_warn("GPT:%lld != %lld\n", | |
1da177e4 LT |
503 | (unsigned long long)le64_to_cpu(pgpt->alternate_lba), |
504 | (unsigned long long)le64_to_cpu(agpt->my_lba)); | |
505 | error_found++; | |
506 | } | |
507 | if (le64_to_cpu(pgpt->first_usable_lba) != | |
508 | le64_to_cpu(agpt->first_usable_lba)) { | |
b4bc4a18 AM |
509 | pr_warn("GPT:first_usable_lbas don't match.\n"); |
510 | pr_warn("GPT:%lld != %lld\n", | |
1da177e4 LT |
511 | (unsigned long long)le64_to_cpu(pgpt->first_usable_lba), |
512 | (unsigned long long)le64_to_cpu(agpt->first_usable_lba)); | |
513 | error_found++; | |
514 | } | |
515 | if (le64_to_cpu(pgpt->last_usable_lba) != | |
516 | le64_to_cpu(agpt->last_usable_lba)) { | |
b4bc4a18 AM |
517 | pr_warn("GPT:last_usable_lbas don't match.\n"); |
518 | pr_warn("GPT:%lld != %lld\n", | |
1da177e4 LT |
519 | (unsigned long long)le64_to_cpu(pgpt->last_usable_lba), |
520 | (unsigned long long)le64_to_cpu(agpt->last_usable_lba)); | |
521 | error_found++; | |
522 | } | |
523 | if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { | |
b4bc4a18 | 524 | pr_warn("GPT:disk_guids don't match.\n"); |
1da177e4 LT |
525 | error_found++; |
526 | } | |
527 | if (le32_to_cpu(pgpt->num_partition_entries) != | |
528 | le32_to_cpu(agpt->num_partition_entries)) { | |
b4bc4a18 | 529 | pr_warn("GPT:num_partition_entries don't match: " |
1da177e4 LT |
530 | "0x%x != 0x%x\n", |
531 | le32_to_cpu(pgpt->num_partition_entries), | |
532 | le32_to_cpu(agpt->num_partition_entries)); | |
533 | error_found++; | |
534 | } | |
535 | if (le32_to_cpu(pgpt->sizeof_partition_entry) != | |
536 | le32_to_cpu(agpt->sizeof_partition_entry)) { | |
b4bc4a18 | 537 | pr_warn("GPT:sizeof_partition_entry values don't match: " |
1da177e4 LT |
538 | "0x%x != 0x%x\n", |
539 | le32_to_cpu(pgpt->sizeof_partition_entry), | |
540 | le32_to_cpu(agpt->sizeof_partition_entry)); | |
541 | error_found++; | |
542 | } | |
543 | if (le32_to_cpu(pgpt->partition_entry_array_crc32) != | |
544 | le32_to_cpu(agpt->partition_entry_array_crc32)) { | |
b4bc4a18 | 545 | pr_warn("GPT:partition_entry_array_crc32 values don't match: " |
1da177e4 LT |
546 | "0x%x != 0x%x\n", |
547 | le32_to_cpu(pgpt->partition_entry_array_crc32), | |
548 | le32_to_cpu(agpt->partition_entry_array_crc32)); | |
549 | error_found++; | |
550 | } | |
551 | if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { | |
b4bc4a18 AM |
552 | pr_warn("GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); |
553 | pr_warn("GPT:%lld != %lld\n", | |
1da177e4 LT |
554 | (unsigned long long)le64_to_cpu(pgpt->alternate_lba), |
555 | (unsigned long long)lastlba); | |
556 | error_found++; | |
557 | } | |
558 | ||
559 | if (le64_to_cpu(agpt->my_lba) != lastlba) { | |
b4bc4a18 AM |
560 | pr_warn("GPT:Alternate GPT header not at the end of the disk.\n"); |
561 | pr_warn("GPT:%lld != %lld\n", | |
1da177e4 LT |
562 | (unsigned long long)le64_to_cpu(agpt->my_lba), |
563 | (unsigned long long)lastlba); | |
564 | error_found++; | |
565 | } | |
566 | ||
567 | if (error_found) | |
b4bc4a18 | 568 | pr_warn("GPT: Use GNU Parted to correct GPT errors.\n"); |
1da177e4 LT |
569 | return; |
570 | } | |
571 | ||
572 | /** | |
573 | * find_valid_gpt() - Search disk for valid GPT headers and PTEs | |
1493bf21 | 574 | * @state |
1da177e4 LT |
575 | * @gpt is a GPT header ptr, filled on return. |
576 | * @ptes is a PTEs ptr, filled on return. | |
577 | * Description: Returns 1 if valid, 0 on error. | |
578 | * If valid, returns pointers to newly allocated GPT header and PTEs. | |
579 | * Validity depends on PMBR being valid (or being overridden by the | |
580 | * 'gpt' kernel command line option) and finding either the Primary | |
581 | * GPT header and PTEs valid, or the Alternate GPT header and PTEs | |
582 | * valid. If the Primary GPT header is not valid, the Alternate GPT header | |
583 | * is not checked unless the 'gpt' kernel command line option is passed. | |
584 | * This protects against devices which misreport their size, and forces | |
585 | * the user to decide to use the Alternate GPT. | |
586 | */ | |
1493bf21 TH |
587 | static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt, |
588 | gpt_entry **ptes) | |
1da177e4 LT |
589 | { |
590 | int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; | |
591 | gpt_header *pgpt = NULL, *agpt = NULL; | |
592 | gpt_entry *pptes = NULL, *aptes = NULL; | |
4c64c30a | 593 | legacy_mbr *legacymbr; |
27a7c642 | 594 | sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9; |
1da177e4 | 595 | u64 lastlba; |
1493bf21 TH |
596 | |
597 | if (!ptes) | |
1da177e4 LT |
598 | return 0; |
599 | ||
1493bf21 | 600 | lastlba = last_lba(state->bdev); |
1da177e4 | 601 | if (!force_gpt) { |
b05ebbbb DB |
602 | /* This will be added to the EFI Spec. per Intel after v1.02. */ |
603 | legacymbr = kzalloc(sizeof(*legacymbr), GFP_KERNEL); | |
604 | if (!legacymbr) | |
605 | goto fail; | |
606 | ||
607 | read_lba(state, 0, (u8 *)legacymbr, sizeof(*legacymbr)); | |
27a7c642 | 608 | good_pmbr = is_pmbr_valid(legacymbr, total_sectors); |
b05ebbbb DB |
609 | kfree(legacymbr); |
610 | ||
611 | if (!good_pmbr) | |
612 | goto fail; | |
613 | ||
614 | pr_debug("Device has a %s MBR\n", | |
615 | good_pmbr == GPT_MBR_PROTECTIVE ? | |
616 | "protective" : "hybrid"); | |
617 | } | |
1da177e4 | 618 | |
1493bf21 | 619 | good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA, |
1da177e4 LT |
620 | &pgpt, &pptes); |
621 | if (good_pgpt) | |
1493bf21 | 622 | good_agpt = is_gpt_valid(state, |
1da177e4 LT |
623 | le64_to_cpu(pgpt->alternate_lba), |
624 | &agpt, &aptes); | |
625 | if (!good_agpt && force_gpt) | |
1493bf21 | 626 | good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes); |
1da177e4 LT |
627 | |
628 | /* The obviously unsuccessful case */ | |
629 | if (!good_pgpt && !good_agpt) | |
630 | goto fail; | |
631 | ||
632 | compare_gpts(pgpt, agpt, lastlba); | |
633 | ||
634 | /* The good cases */ | |
635 | if (good_pgpt) { | |
636 | *gpt = pgpt; | |
637 | *ptes = pptes; | |
638 | kfree(agpt); | |
639 | kfree(aptes); | |
70f637e9 | 640 | if (!good_agpt) |
b4bc4a18 | 641 | pr_warn("Alternate GPT is invalid, using primary GPT.\n"); |
1da177e4 LT |
642 | return 1; |
643 | } | |
644 | else if (good_agpt) { | |
645 | *gpt = agpt; | |
646 | *ptes = aptes; | |
647 | kfree(pgpt); | |
648 | kfree(pptes); | |
b4bc4a18 | 649 | pr_warn("Primary GPT is invalid, using alternate GPT.\n"); |
1da177e4 LT |
650 | return 1; |
651 | } | |
652 | ||
653 | fail: | |
654 | kfree(pgpt); | |
655 | kfree(agpt); | |
656 | kfree(pptes); | |
657 | kfree(aptes); | |
658 | *gpt = NULL; | |
659 | *ptes = NULL; | |
660 | return 0; | |
661 | } | |
662 | ||
663 | /** | |
1493bf21 | 664 | * efi_partition(struct parsed_partitions *state) |
1da177e4 | 665 | * @state |
1da177e4 LT |
666 | * |
667 | * Description: called from check.c, if the disk contains GPT | |
668 | * partitions, sets up partition entries in the kernel. | |
669 | * | |
670 | * If the first block on the disk is a legacy MBR, | |
671 | * it will get handled by msdos_partition(). | |
672 | * If it's a Protective MBR, we'll handle it here. | |
673 | * | |
674 | * We do not create a Linux partition for GPT, but | |
675 | * only for the actual data partitions. | |
676 | * Returns: | |
677 | * -1 if unable to read the partition table | |
678 | * 0 if this isn't our partition table | |
679 | * 1 if successful | |
680 | * | |
681 | */ | |
1493bf21 | 682 | int efi_partition(struct parsed_partitions *state) |
1da177e4 LT |
683 | { |
684 | gpt_header *gpt = NULL; | |
685 | gpt_entry *ptes = NULL; | |
686 | u32 i; | |
1493bf21 | 687 | unsigned ssz = bdev_logical_block_size(state->bdev) / 512; |
1da177e4 | 688 | |
1493bf21 | 689 | if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) { |
1da177e4 LT |
690 | kfree(gpt); |
691 | kfree(ptes); | |
692 | return 0; | |
693 | } | |
694 | ||
d9916962 | 695 | pr_debug("GUID Partition Table is valid! Yea!\n"); |
1da177e4 LT |
696 | |
697 | for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) { | |
eec7ecfe WD |
698 | struct partition_meta_info *info; |
699 | unsigned label_count = 0; | |
700 | unsigned label_max; | |
7d13af32 KZ |
701 | u64 start = le64_to_cpu(ptes[i].starting_lba); |
702 | u64 size = le64_to_cpu(ptes[i].ending_lba) - | |
703 | le64_to_cpu(ptes[i].starting_lba) + 1ULL; | |
704 | ||
1493bf21 | 705 | if (!is_pte_valid(&ptes[i], last_lba(state->bdev))) |
1da177e4 LT |
706 | continue; |
707 | ||
7d13af32 | 708 | put_partition(state, i+1, start * ssz, size * ssz); |
1da177e4 LT |
709 | |
710 | /* If this is a RAID volume, tell md */ | |
70f637e9 | 711 | if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID)) |
cc910624 | 712 | state->parts[i + 1].flags = ADDPART_FLAG_RAID; |
eec7ecfe WD |
713 | |
714 | info = &state->parts[i + 1].info; | |
1ad7e899 | 715 | efi_guid_unparse(&ptes[i].unique_partition_guid, info->uuid); |
eec7ecfe WD |
716 | |
717 | /* Naively convert UTF16-LE to 7 bits. */ | |
718 | label_max = min(sizeof(info->volname) - 1, | |
719 | sizeof(ptes[i].partition_name)); | |
720 | info->volname[label_max] = 0; | |
721 | while (label_count < label_max) { | |
722 | u8 c = ptes[i].partition_name[label_count] & 0xff; | |
723 | if (c && !isprint(c)) | |
724 | c = '!'; | |
725 | info->volname[label_count] = c; | |
726 | label_count++; | |
727 | } | |
728 | state->parts[i + 1].has_info = true; | |
1da177e4 LT |
729 | } |
730 | kfree(ptes); | |
731 | kfree(gpt); | |
9c867fbe | 732 | strlcat(state->pp_buf, "\n", PAGE_SIZE); |
1da177e4 LT |
733 | return 1; |
734 | } |