blob: 6296b403c67a3d5ca512b05e048ecf3525330153 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/************************************************************
2 * EFI GUID Partition Table handling
Karel Zak7d13af32009-11-23 09:29:13 +01003 *
4 * http://www.uefi.org/specs/
5 * http://www.intel.com/technology/efi/
6 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com>
8 * Copyright 2000,2001,2002,2004 Dell Inc.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 *
24 *
25 * TODO:
26 *
27 * Changelog:
28 * Mon Nov 09 2004 Matt Domsch <Matt_Domsch@dell.com>
29 * - test for valid PMBR and valid PGPT before ever reading
30 * AGPT, allow override with 'gpt' kernel command line option.
31 * - check for first/last_usable_lba outside of size of disk
32 *
33 * Tue Mar 26 2002 Matt Domsch <Matt_Domsch@dell.com>
34 * - Ported to 2.5.7-pre1 and 2.5.7-dj2
35 * - Applied patch to avoid fault in alternate header handling
36 * - cleaned up find_valid_gpt
37 * - On-disk structure and copy in memory is *always* LE now -
38 * swab fields as needed
39 * - remove print_gpt_header()
40 * - only use first max_p partition entries, to keep the kernel minor number
41 * and partition numbers tied.
42 *
43 * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com>
44 * - Removed __PRIPTR_PREFIX - not being used
45 *
46 * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com>
47 * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied
48 *
49 * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com>
50 * - Added compare_gpts().
51 * - moved le_efi_guid_to_cpus() back into this file. GPT is the only
52 * thing that keeps EFI GUIDs on disk.
53 * - Changed gpt structure names and members to be simpler and more Linux-like.
54 *
55 * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com>
56 * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck
57 *
58 * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com>
59 * - Changed function comments to DocBook style per Andreas Dilger suggestion.
60 *
61 * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com>
62 * - Change read_lba() to use the page cache per Al Viro's work.
63 * - print u64s properly on all architectures
64 * - fixed debug_printk(), now Dprintk()
65 *
66 * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com>
67 * - Style cleanups
68 * - made most functions static
69 * - Endianness addition
70 * - remove test for second alternate header, as it's not per spec,
71 * and is unnecessary. There's now a method to read/write the last
72 * sector of an odd-sized disk from user space. No tools have ever
73 * been released which used this code, so it's effectively dead.
74 * - Per Asit Mallick of Intel, added a test for a valid PMBR.
75 * - Added kernel command line option 'gpt' to override valid PMBR test.
76 *
77 * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com>
78 * - added devfs volume UUID support (/dev/volumes/uuids) for
79 * mounting file systems by the partition GUID.
80 *
81 * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com>
82 * - Moved crc32() to linux/lib, added efi_crc32().
83 *
84 * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com>
85 * - Replaced Intel's CRC32 function with an equivalent
86 * non-license-restricted version.
87 *
88 * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com>
89 * - Fixed the last_lba() call to return the proper last block
90 *
91 * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com>
92 * - Thanks to Andries Brouwer for his debugging assistance.
93 * - Code works, detects all the partitions.
94 *
95 ************************************************************/
Linus Torvalds1da177e2005-04-16 15:20:36 -070096#include <linux/crc32.h>
Will Drewryeec7ecf2010-08-31 15:47:06 -050097#include <linux/ctype.h>
Karel Zak7d13af32009-11-23 09:29:13 +010098#include <linux/math64.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090099#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100#include "check.h"
101#include "efi.h"
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103/* This allows a kernel command line option 'gpt' to override
104 * the test for invalid PMBR. Not __initdata because reloading
105 * the partition tables happens after init too.
106 */
107static int force_gpt;
108static int __init
109force_gpt_fn(char *str)
110{
111 force_gpt = 1;
112 return 1;
113}
114__setup("gpt", force_gpt_fn);
115
116
117/**
118 * efi_crc32() - EFI version of crc32 function
119 * @buf: buffer to calculate crc32 of
120 * @len - length of buf
121 *
122 * Description: Returns EFI-style CRC32 value for @buf
123 *
124 * This function uses the little endian Ethernet polynomial
125 * but seeds the function with ~0, and xor's with ~0 at the end.
126 * Note, the EFI Specification, v1.02, has a reference to
127 * Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
128 */
129static inline u32
130efi_crc32(const void *buf, unsigned long len)
131{
132 return (crc32(~0L, buf, len) ^ ~0L);
133}
134
135/**
136 * last_lba(): return number of last logical block of device
137 * @bdev: block device
138 *
139 * Description: Returns last LBA value on success, 0 on error.
140 * This is stored (by sd and ide-geometry) in
141 * the part[0] entry for this disk, and is the number of
142 * physical sectors available on the disk.
143 */
Tejun Heo1493bf22010-05-15 20:09:30 +0200144static u64 last_lba(struct block_device *bdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145{
146 if (!bdev || !bdev->bd_inode)
147 return 0;
Karel Zak7d13af32009-11-23 09:29:13 +0100148 return div_u64(bdev->bd_inode->i_size,
149 bdev_logical_block_size(bdev)) - 1ULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150}
151
152static inline int
Olaf Hering4c64c302007-05-10 22:22:42 -0700153pmbr_part_valid(struct partition *part)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154{
155 if (part->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT &&
156 le32_to_cpu(part->start_sect) == 1UL)
157 return 1;
158 return 0;
159}
160
161/**
162 * is_pmbr_valid(): test Protective MBR for validity
163 * @mbr: pointer to a legacy mbr structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 *
165 * Description: Returns 1 if PMBR is valid, 0 otherwise.
166 * Validity depends on two things:
167 * 1) MSDOS signature is in the last two bytes of the MBR
168 * 2) One partition of type 0xEE is found
169 */
170static int
Olaf Hering4c64c302007-05-10 22:22:42 -0700171is_pmbr_valid(legacy_mbr *mbr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172{
173 int i;
174 if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
175 return 0;
176 for (i = 0; i < 4; i++)
Olaf Hering4c64c302007-05-10 22:22:42 -0700177 if (pmbr_part_valid(&mbr->partition_record[i]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 return 1;
179 return 0;
180}
181
182/**
183 * read_lba(): Read bytes from disk, starting at given LBA
Tejun Heo1493bf22010-05-15 20:09:30 +0200184 * @state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 * @lba
186 * @buffer
187 * @size_t
188 *
Tejun Heo1493bf22010-05-15 20:09:30 +0200189 * Description: Reads @count bytes from @state->bdev into @buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 * Returns number of bytes read on success, 0 on error.
191 */
Tejun Heo1493bf22010-05-15 20:09:30 +0200192static size_t read_lba(struct parsed_partitions *state,
193 u64 lba, u8 *buffer, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194{
195 size_t totalreadcount = 0;
Tejun Heo1493bf22010-05-15 20:09:30 +0200196 struct block_device *bdev = state->bdev;
Karel Zak7d13af32009-11-23 09:29:13 +0100197 sector_t n = lba * (bdev_logical_block_size(bdev) / 512);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
Tejun Heo1493bf22010-05-15 20:09:30 +0200199 if (!buffer || lba > last_lba(bdev))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 return 0;
201
202 while (count) {
203 int copied = 512;
204 Sector sect;
Tejun Heo1493bf22010-05-15 20:09:30 +0200205 unsigned char *data = read_part_sector(state, n++, &sect);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 if (!data)
207 break;
208 if (copied > count)
209 copied = count;
210 memcpy(buffer, data, copied);
211 put_dev_sector(sect);
212 buffer += copied;
213 totalreadcount +=copied;
214 count -= copied;
215 }
216 return totalreadcount;
217}
218
219/**
220 * alloc_read_gpt_entries(): reads partition entries from disk
Tejun Heo1493bf22010-05-15 20:09:30 +0200221 * @state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 * @gpt - GPT header
223 *
224 * Description: Returns ptes on success, NULL on error.
225 * Allocates space for PTEs based on information found in @gpt.
226 * Notes: remember to free pte when you're done!
227 */
Tejun Heo1493bf22010-05-15 20:09:30 +0200228static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state,
229 gpt_header *gpt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230{
231 size_t count;
232 gpt_entry *pte;
Tejun Heo1493bf22010-05-15 20:09:30 +0200233
234 if (!gpt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 return NULL;
236
237 count = le32_to_cpu(gpt->num_partition_entries) *
238 le32_to_cpu(gpt->sizeof_partition_entry);
239 if (!count)
240 return NULL;
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700241 pte = kzalloc(count, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 if (!pte)
243 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
Tejun Heo1493bf22010-05-15 20:09:30 +0200245 if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 (u8 *) pte,
247 count) < count) {
248 kfree(pte);
249 pte=NULL;
250 return NULL;
251 }
252 return pte;
253}
254
255/**
256 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
Tejun Heo1493bf22010-05-15 20:09:30 +0200257 * @state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 * @lba is the Logical Block Address of the partition table
259 *
260 * Description: returns GPT header on success, NULL on error. Allocates
Tejun Heo1493bf22010-05-15 20:09:30 +0200261 * and fills a GPT header starting at @ from @state->bdev.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 * Note: remember to free gpt when finished with it.
263 */
Tejun Heo1493bf22010-05-15 20:09:30 +0200264static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
265 u64 lba)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266{
267 gpt_header *gpt;
Tejun Heo1493bf22010-05-15 20:09:30 +0200268 unsigned ssz = bdev_logical_block_size(state->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
Karel Zak87038c2d2009-11-23 09:29:58 +0100270 gpt = kzalloc(ssz, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 if (!gpt)
272 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
Tejun Heo1493bf22010-05-15 20:09:30 +0200274 if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 kfree(gpt);
276 gpt=NULL;
277 return NULL;
278 }
279
280 return gpt;
281}
282
283/**
284 * is_gpt_valid() - tests one GPT header and PTEs for validity
Tejun Heo1493bf22010-05-15 20:09:30 +0200285 * @state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 * @lba is the logical block address of the GPT header to test
287 * @gpt is a GPT header ptr, filled on return.
288 * @ptes is a PTEs ptr, filled on return.
289 *
290 * Description: returns 1 if valid, 0 on error.
291 * If valid, returns pointers to newly allocated GPT header and PTEs.
292 */
Tejun Heo1493bf22010-05-15 20:09:30 +0200293static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
294 gpt_header **gpt, gpt_entry **ptes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295{
296 u32 crc, origcrc;
297 u64 lastlba;
298
Tejun Heo1493bf22010-05-15 20:09:30 +0200299 if (!ptes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 return 0;
Tejun Heo1493bf22010-05-15 20:09:30 +0200301 if (!(*gpt = alloc_read_gpt_header(state, lba)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 return 0;
303
304 /* Check the GUID Partition Table signature */
305 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
Thomas Gleixnerd9916962008-07-25 01:48:26 -0700306 pr_debug("GUID Partition Table Header signature is wrong:"
307 "%lld != %lld\n",
308 (unsigned long long)le64_to_cpu((*gpt)->signature),
309 (unsigned long long)GPT_HEADER_SIGNATURE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 goto fail;
311 }
312
Timo Warns3eb8e742011-05-26 16:25:57 -0700313 /* Check the GUID Partition Table header size */
314 if (le32_to_cpu((*gpt)->header_size) >
315 bdev_logical_block_size(state->bdev)) {
316 pr_debug("GUID Partition Table Header size is wrong: %u > %u\n",
317 le32_to_cpu((*gpt)->header_size),
318 bdev_logical_block_size(state->bdev));
319 goto fail;
320 }
321
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 /* Check the GUID Partition Table CRC */
323 origcrc = le32_to_cpu((*gpt)->header_crc32);
324 (*gpt)->header_crc32 = 0;
325 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
326
327 if (crc != origcrc) {
Thomas Gleixnerd9916962008-07-25 01:48:26 -0700328 pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
329 crc, origcrc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 goto fail;
331 }
332 (*gpt)->header_crc32 = cpu_to_le32(origcrc);
333
334 /* Check that the my_lba entry points to the LBA that contains
335 * the GUID Partition Table */
336 if (le64_to_cpu((*gpt)->my_lba) != lba) {
Thomas Gleixnerd9916962008-07-25 01:48:26 -0700337 pr_debug("GPT my_lba incorrect: %lld != %lld\n",
338 (unsigned long long)le64_to_cpu((*gpt)->my_lba),
339 (unsigned long long)lba);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 goto fail;
341 }
342
343 /* Check the first_usable_lba and last_usable_lba are
344 * within the disk.
345 */
Tejun Heo1493bf22010-05-15 20:09:30 +0200346 lastlba = last_lba(state->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
Thomas Gleixnerd9916962008-07-25 01:48:26 -0700348 pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
349 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
350 (unsigned long long)lastlba);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 goto fail;
352 }
353 if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
Thomas Gleixnerd9916962008-07-25 01:48:26 -0700354 pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
355 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
356 (unsigned long long)lastlba);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 goto fail;
358 }
359
Timo Warnsfa039d52011-05-06 13:47:35 +0200360 /* Check that sizeof_partition_entry has the correct value */
361 if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
362 pr_debug("GUID Partitition Entry Size check failed.\n");
363 goto fail;
364 }
365
Tejun Heo1493bf22010-05-15 20:09:30 +0200366 if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 goto fail;
368
369 /* Check the GUID Partition Entry Array CRC */
370 crc = efi_crc32((const unsigned char *) (*ptes),
371 le32_to_cpu((*gpt)->num_partition_entries) *
372 le32_to_cpu((*gpt)->sizeof_partition_entry));
373
374 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
Thomas Gleixnerd9916962008-07-25 01:48:26 -0700375 pr_debug("GUID Partitition Entry Array CRC check failed.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 goto fail_ptes;
377 }
378
379 /* We're done, all's well */
380 return 1;
381
382 fail_ptes:
383 kfree(*ptes);
384 *ptes = NULL;
385 fail:
386 kfree(*gpt);
387 *gpt = NULL;
388 return 0;
389}
390
391/**
392 * is_pte_valid() - tests one PTE for validity
393 * @pte is the pte to check
394 * @lastlba is last lba of the disk
395 *
396 * Description: returns 1 if valid, 0 on error.
397 */
398static inline int
399is_pte_valid(const gpt_entry *pte, const u64 lastlba)
400{
401 if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
402 le64_to_cpu(pte->starting_lba) > lastlba ||
403 le64_to_cpu(pte->ending_lba) > lastlba)
404 return 0;
405 return 1;
406}
407
408/**
409 * compare_gpts() - Search disk for valid GPT headers and PTEs
410 * @pgpt is the primary GPT header
411 * @agpt is the alternate GPT header
412 * @lastlba is the last LBA number
413 * Description: Returns nothing. Sanity checks pgpt and agpt fields
414 * and prints warnings on discrepancies.
415 *
416 */
417static void
418compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
419{
420 int error_found = 0;
421 if (!pgpt || !agpt)
422 return;
423 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
424 printk(KERN_WARNING
425 "GPT:Primary header LBA != Alt. header alternate_lba\n");
426 printk(KERN_WARNING "GPT:%lld != %lld\n",
427 (unsigned long long)le64_to_cpu(pgpt->my_lba),
428 (unsigned long long)le64_to_cpu(agpt->alternate_lba));
429 error_found++;
430 }
431 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
432 printk(KERN_WARNING
433 "GPT:Primary header alternate_lba != Alt. header my_lba\n");
434 printk(KERN_WARNING "GPT:%lld != %lld\n",
435 (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
436 (unsigned long long)le64_to_cpu(agpt->my_lba));
437 error_found++;
438 }
439 if (le64_to_cpu(pgpt->first_usable_lba) !=
440 le64_to_cpu(agpt->first_usable_lba)) {
441 printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n");
442 printk(KERN_WARNING "GPT:%lld != %lld\n",
443 (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
444 (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
445 error_found++;
446 }
447 if (le64_to_cpu(pgpt->last_usable_lba) !=
448 le64_to_cpu(agpt->last_usable_lba)) {
449 printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n");
450 printk(KERN_WARNING "GPT:%lld != %lld\n",
451 (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
452 (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
453 error_found++;
454 }
455 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
456 printk(KERN_WARNING "GPT:disk_guids don't match.\n");
457 error_found++;
458 }
459 if (le32_to_cpu(pgpt->num_partition_entries) !=
460 le32_to_cpu(agpt->num_partition_entries)) {
461 printk(KERN_WARNING "GPT:num_partition_entries don't match: "
462 "0x%x != 0x%x\n",
463 le32_to_cpu(pgpt->num_partition_entries),
464 le32_to_cpu(agpt->num_partition_entries));
465 error_found++;
466 }
467 if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
468 le32_to_cpu(agpt->sizeof_partition_entry)) {
469 printk(KERN_WARNING
470 "GPT:sizeof_partition_entry values don't match: "
471 "0x%x != 0x%x\n",
472 le32_to_cpu(pgpt->sizeof_partition_entry),
473 le32_to_cpu(agpt->sizeof_partition_entry));
474 error_found++;
475 }
476 if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
477 le32_to_cpu(agpt->partition_entry_array_crc32)) {
478 printk(KERN_WARNING
479 "GPT:partition_entry_array_crc32 values don't match: "
480 "0x%x != 0x%x\n",
481 le32_to_cpu(pgpt->partition_entry_array_crc32),
482 le32_to_cpu(agpt->partition_entry_array_crc32));
483 error_found++;
484 }
485 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
486 printk(KERN_WARNING
487 "GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
488 printk(KERN_WARNING "GPT:%lld != %lld\n",
489 (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
490 (unsigned long long)lastlba);
491 error_found++;
492 }
493
494 if (le64_to_cpu(agpt->my_lba) != lastlba) {
495 printk(KERN_WARNING
496 "GPT:Alternate GPT header not at the end of the disk.\n");
497 printk(KERN_WARNING "GPT:%lld != %lld\n",
498 (unsigned long long)le64_to_cpu(agpt->my_lba),
499 (unsigned long long)lastlba);
500 error_found++;
501 }
502
503 if (error_found)
504 printk(KERN_WARNING
505 "GPT: Use GNU Parted to correct GPT errors.\n");
506 return;
507}
508
509/**
510 * find_valid_gpt() - Search disk for valid GPT headers and PTEs
Tejun Heo1493bf22010-05-15 20:09:30 +0200511 * @state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 * @gpt is a GPT header ptr, filled on return.
513 * @ptes is a PTEs ptr, filled on return.
514 * Description: Returns 1 if valid, 0 on error.
515 * If valid, returns pointers to newly allocated GPT header and PTEs.
516 * Validity depends on PMBR being valid (or being overridden by the
517 * 'gpt' kernel command line option) and finding either the Primary
518 * GPT header and PTEs valid, or the Alternate GPT header and PTEs
519 * valid. If the Primary GPT header is not valid, the Alternate GPT header
520 * is not checked unless the 'gpt' kernel command line option is passed.
521 * This protects against devices which misreport their size, and forces
522 * the user to decide to use the Alternate GPT.
523 */
Tejun Heo1493bf22010-05-15 20:09:30 +0200524static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
525 gpt_entry **ptes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526{
527 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
528 gpt_header *pgpt = NULL, *agpt = NULL;
529 gpt_entry *pptes = NULL, *aptes = NULL;
Olaf Hering4c64c302007-05-10 22:22:42 -0700530 legacy_mbr *legacymbr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 u64 lastlba;
Tejun Heo1493bf22010-05-15 20:09:30 +0200532
533 if (!ptes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 return 0;
535
Tejun Heo1493bf22010-05-15 20:09:30 +0200536 lastlba = last_lba(state->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 if (!force_gpt) {
538 /* This will be added to the EFI Spec. per Intel after v1.02. */
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700539 legacymbr = kzalloc(sizeof (*legacymbr), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 if (legacymbr) {
Tejun Heo1493bf22010-05-15 20:09:30 +0200541 read_lba(state, 0, (u8 *) legacymbr,
542 sizeof (*legacymbr));
Olaf Hering4c64c302007-05-10 22:22:42 -0700543 good_pmbr = is_pmbr_valid(legacymbr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 kfree(legacymbr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 }
546 if (!good_pmbr)
547 goto fail;
548 }
549
Tejun Heo1493bf22010-05-15 20:09:30 +0200550 good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 &pgpt, &pptes);
552 if (good_pgpt)
Tejun Heo1493bf22010-05-15 20:09:30 +0200553 good_agpt = is_gpt_valid(state,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 le64_to_cpu(pgpt->alternate_lba),
555 &agpt, &aptes);
556 if (!good_agpt && force_gpt)
Tejun Heo1493bf22010-05-15 20:09:30 +0200557 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
559 /* The obviously unsuccessful case */
560 if (!good_pgpt && !good_agpt)
561 goto fail;
562
563 compare_gpts(pgpt, agpt, lastlba);
564
565 /* The good cases */
566 if (good_pgpt) {
567 *gpt = pgpt;
568 *ptes = pptes;
569 kfree(agpt);
570 kfree(aptes);
571 if (!good_agpt) {
572 printk(KERN_WARNING
573 "Alternate GPT is invalid, "
574 "using primary GPT.\n");
575 }
576 return 1;
577 }
578 else if (good_agpt) {
579 *gpt = agpt;
580 *ptes = aptes;
581 kfree(pgpt);
582 kfree(pptes);
583 printk(KERN_WARNING
584 "Primary GPT is invalid, using alternate GPT.\n");
585 return 1;
586 }
587
588 fail:
589 kfree(pgpt);
590 kfree(agpt);
591 kfree(pptes);
592 kfree(aptes);
593 *gpt = NULL;
594 *ptes = NULL;
595 return 0;
596}
597
598/**
Tejun Heo1493bf22010-05-15 20:09:30 +0200599 * efi_partition(struct parsed_partitions *state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 * @state
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 *
602 * Description: called from check.c, if the disk contains GPT
603 * partitions, sets up partition entries in the kernel.
604 *
605 * If the first block on the disk is a legacy MBR,
606 * it will get handled by msdos_partition().
607 * If it's a Protective MBR, we'll handle it here.
608 *
609 * We do not create a Linux partition for GPT, but
610 * only for the actual data partitions.
611 * Returns:
612 * -1 if unable to read the partition table
613 * 0 if this isn't our partition table
614 * 1 if successful
615 *
616 */
Tejun Heo1493bf22010-05-15 20:09:30 +0200617int efi_partition(struct parsed_partitions *state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618{
619 gpt_header *gpt = NULL;
620 gpt_entry *ptes = NULL;
621 u32 i;
Tejun Heo1493bf22010-05-15 20:09:30 +0200622 unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
Will Drewryeec7ecf2010-08-31 15:47:06 -0500623 u8 unparsed_guid[37];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
Tejun Heo1493bf22010-05-15 20:09:30 +0200625 if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 kfree(gpt);
627 kfree(ptes);
628 return 0;
629 }
630
Thomas Gleixnerd9916962008-07-25 01:48:26 -0700631 pr_debug("GUID Partition Table is valid! Yea!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
633 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
Will Drewryeec7ecf2010-08-31 15:47:06 -0500634 struct partition_meta_info *info;
635 unsigned label_count = 0;
636 unsigned label_max;
Karel Zak7d13af32009-11-23 09:29:13 +0100637 u64 start = le64_to_cpu(ptes[i].starting_lba);
638 u64 size = le64_to_cpu(ptes[i].ending_lba) -
639 le64_to_cpu(ptes[i].starting_lba) + 1ULL;
640
Tejun Heo1493bf22010-05-15 20:09:30 +0200641 if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 continue;
643
Karel Zak7d13af32009-11-23 09:29:13 +0100644 put_partition(state, i+1, start * ssz, size * ssz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645
646 /* If this is a RAID volume, tell md */
647 if (!efi_guidcmp(ptes[i].partition_type_guid,
648 PARTITION_LINUX_RAID_GUID))
Cesar Eduardo Barroscc910622010-04-17 19:28:09 -0300649 state->parts[i + 1].flags = ADDPART_FLAG_RAID;
Will Drewryeec7ecf2010-08-31 15:47:06 -0500650
651 info = &state->parts[i + 1].info;
652 /* Instead of doing a manual swap to big endian, reuse the
653 * common ASCII hex format as the interim.
654 */
655 efi_guid_unparse(&ptes[i].unique_partition_guid, unparsed_guid);
656 part_pack_uuid(unparsed_guid, info->uuid);
657
658 /* Naively convert UTF16-LE to 7 bits. */
659 label_max = min(sizeof(info->volname) - 1,
660 sizeof(ptes[i].partition_name));
661 info->volname[label_max] = 0;
662 while (label_count < label_max) {
663 u8 c = ptes[i].partition_name[label_count] & 0xff;
664 if (c && !isprint(c))
665 c = '!';
666 info->volname[label_count] = c;
667 label_count++;
668 }
669 state->parts[i + 1].has_info = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 }
671 kfree(ptes);
672 kfree(gpt);
Alexey Dobriyan9c867fb2010-08-10 18:03:14 -0700673 strlcat(state->pp_buf, "\n", PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 return 1;
675}