1 /************************************************************
2  * EFI GUID Partition Table handling
3  *
4  * http://www.uefi.org/specs/
5  * http://www.intel.com/technology/efi/
6  *
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:
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  ************************************************************/
96 #include <linux/crc32.h>
97 #include <linux/ctype.h>
98 #include <linux/math64.h>
99 #include <linux/slab.h>
100 #include "check.h"
101 #include "efi.h"
102 
103 /* 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  */
107 static int force_gpt;
108 static int __init
force_gpt_fn(char * str)109 force_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  */
129 static inline u32
efi_crc32(const void * buf,unsigned long len)130 efi_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  */
last_lba(struct block_device * bdev)144 static u64 last_lba(struct block_device *bdev)
145 {
146 	if (!bdev || !bdev->bd_inode)
147 		return 0;
148 	return div_u64(bdev->bd_inode->i_size,
149 		       bdev_logical_block_size(bdev)) - 1ULL;
150 }
151 
152 static inline int
pmbr_part_valid(struct partition * part)153 pmbr_part_valid(struct partition *part)
154 {
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
164  *
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  */
170 static int
is_pmbr_valid(legacy_mbr * mbr)171 is_pmbr_valid(legacy_mbr *mbr)
172 {
173 	int i;
174 	if (!mbr || le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
175                 return 0;
176 	for (i = 0; i < 4; i++)
177 		if (pmbr_part_valid(&mbr->partition_record[i]))
178                         return 1;
179 	return 0;
180 }
181 
182 /**
183  * read_lba(): Read bytes from disk, starting at given LBA
184  * @state
185  * @lba
186  * @buffer
187  * @size_t
188  *
189  * Description: Reads @count bytes from @state->bdev into @buffer.
190  * Returns number of bytes read on success, 0 on error.
191  */
read_lba(struct parsed_partitions * state,u64 lba,u8 * buffer,size_t count)192 static size_t read_lba(struct parsed_partitions *state,
193 		       u64 lba, u8 *buffer, size_t count)
194 {
195 	size_t totalreadcount = 0;
196 	struct block_device *bdev = state->bdev;
197 	sector_t n = lba * (bdev_logical_block_size(bdev) / 512);
198 
199 	if (!buffer || lba > last_lba(bdev))
200                 return 0;
201 
202 	while (count) {
203 		int copied = 512;
204 		Sector sect;
205 		unsigned char *data = read_part_sector(state, n++, &sect);
206 		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
221  * @state
222  * @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  */
alloc_read_gpt_entries(struct parsed_partitions * state,gpt_header * gpt)228 static gpt_entry *alloc_read_gpt_entries(struct parsed_partitions *state,
229 					 gpt_header *gpt)
230 {
231 	size_t count;
232 	gpt_entry *pte;
233 
234 	if (!gpt)
235 		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;
241 	pte = kzalloc(count, GFP_KERNEL);
242 	if (!pte)
243 		return NULL;
244 
245 	if (read_lba(state, le64_to_cpu(gpt->partition_entry_lba),
246                      (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
257  * @state
258  * @lba is the Logical Block Address of the partition table
259  *
260  * Description: returns GPT header on success, NULL on error.   Allocates
261  * and fills a GPT header starting at @ from @state->bdev.
262  * Note: remember to free gpt when finished with it.
263  */
alloc_read_gpt_header(struct parsed_partitions * state,u64 lba)264 static gpt_header *alloc_read_gpt_header(struct parsed_partitions *state,
265 					 u64 lba)
266 {
267 	gpt_header *gpt;
268 	unsigned ssz = bdev_logical_block_size(state->bdev);
269 
270 	gpt = kzalloc(ssz, GFP_KERNEL);
271 	if (!gpt)
272 		return NULL;
273 
274 	if (read_lba(state, lba, (u8 *) gpt, ssz) < ssz) {
275 		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
285  * @state
286  * @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  */
is_gpt_valid(struct parsed_partitions * state,u64 lba,gpt_header ** gpt,gpt_entry ** ptes)293 static int is_gpt_valid(struct parsed_partitions *state, u64 lba,
294 			gpt_header **gpt, gpt_entry **ptes)
295 {
296 	u32 crc, origcrc;
297 	u64 lastlba;
298 
299 	if (!ptes)
300 		return 0;
301 	if (!(*gpt = alloc_read_gpt_header(state, lba)))
302 		return 0;
303 
304 	/* Check the GUID Partition Table signature */
305 	if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
306 		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);
310 		goto fail;
311 	}
312 
313 	/* Check the GUID Partition Table CRC */
314 	origcrc = le32_to_cpu((*gpt)->header_crc32);
315 	(*gpt)->header_crc32 = 0;
316 	crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
317 
318 	if (crc != origcrc) {
319 		pr_debug("GUID Partition Table Header CRC is wrong: %x != %x\n",
320 			 crc, origcrc);
321 		goto fail;
322 	}
323 	(*gpt)->header_crc32 = cpu_to_le32(origcrc);
324 
325 	/* Check that the my_lba entry points to the LBA that contains
326 	 * the GUID Partition Table */
327 	if (le64_to_cpu((*gpt)->my_lba) != lba) {
328 		pr_debug("GPT my_lba incorrect: %lld != %lld\n",
329 			 (unsigned long long)le64_to_cpu((*gpt)->my_lba),
330 			 (unsigned long long)lba);
331 		goto fail;
332 	}
333 
334 	/* Check the first_usable_lba and last_usable_lba are
335 	 * within the disk.
336 	 */
337 	lastlba = last_lba(state->bdev);
338 	if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
339 		pr_debug("GPT: first_usable_lba incorrect: %lld > %lld\n",
340 			 (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
341 			 (unsigned long long)lastlba);
342 		goto fail;
343 	}
344 	if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
345 		pr_debug("GPT: last_usable_lba incorrect: %lld > %lld\n",
346 			 (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
347 			 (unsigned long long)lastlba);
348 		goto fail;
349 	}
350 
351 	/* Check that sizeof_partition_entry has the correct value */
352 	if (le32_to_cpu((*gpt)->sizeof_partition_entry) != sizeof(gpt_entry)) {
353 		pr_debug("GUID Partitition Entry Size check failed.\n");
354 		goto fail;
355 	}
356 
357 	if (!(*ptes = alloc_read_gpt_entries(state, *gpt)))
358 		goto fail;
359 
360 	/* Check the GUID Partition Entry Array CRC */
361 	crc = efi_crc32((const unsigned char *) (*ptes),
362 			le32_to_cpu((*gpt)->num_partition_entries) *
363 			le32_to_cpu((*gpt)->sizeof_partition_entry));
364 
365 	if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
366 		pr_debug("GUID Partitition Entry Array CRC check failed.\n");
367 		goto fail_ptes;
368 	}
369 
370 	/* We're done, all's well */
371 	return 1;
372 
373  fail_ptes:
374 	kfree(*ptes);
375 	*ptes = NULL;
376  fail:
377 	kfree(*gpt);
378 	*gpt = NULL;
379 	return 0;
380 }
381 
382 /**
383  * is_pte_valid() - tests one PTE for validity
384  * @pte is the pte to check
385  * @lastlba is last lba of the disk
386  *
387  * Description: returns 1 if valid,  0 on error.
388  */
389 static inline int
is_pte_valid(const gpt_entry * pte,const u64 lastlba)390 is_pte_valid(const gpt_entry *pte, const u64 lastlba)
391 {
392 	if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
393 	    le64_to_cpu(pte->starting_lba) > lastlba         ||
394 	    le64_to_cpu(pte->ending_lba)   > lastlba)
395 		return 0;
396 	return 1;
397 }
398 
399 /**
400  * compare_gpts() - Search disk for valid GPT headers and PTEs
401  * @pgpt is the primary GPT header
402  * @agpt is the alternate GPT header
403  * @lastlba is the last LBA number
404  * Description: Returns nothing.  Sanity checks pgpt and agpt fields
405  * and prints warnings on discrepancies.
406  *
407  */
408 static void
compare_gpts(gpt_header * pgpt,gpt_header * agpt,u64 lastlba)409 compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
410 {
411 	int error_found = 0;
412 	if (!pgpt || !agpt)
413 		return;
414 	if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
415 		printk(KERN_WARNING
416 		       "GPT:Primary header LBA != Alt. header alternate_lba\n");
417 		printk(KERN_WARNING "GPT:%lld != %lld\n",
418 		       (unsigned long long)le64_to_cpu(pgpt->my_lba),
419                        (unsigned long long)le64_to_cpu(agpt->alternate_lba));
420 		error_found++;
421 	}
422 	if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
423 		printk(KERN_WARNING
424 		       "GPT:Primary header alternate_lba != Alt. header my_lba\n");
425 		printk(KERN_WARNING "GPT:%lld != %lld\n",
426 		       (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
427                        (unsigned long long)le64_to_cpu(agpt->my_lba));
428 		error_found++;
429 	}
430 	if (le64_to_cpu(pgpt->first_usable_lba) !=
431             le64_to_cpu(agpt->first_usable_lba)) {
432 		printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n");
433 		printk(KERN_WARNING "GPT:%lld != %lld\n",
434 		       (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
435                        (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
436 		error_found++;
437 	}
438 	if (le64_to_cpu(pgpt->last_usable_lba) !=
439             le64_to_cpu(agpt->last_usable_lba)) {
440 		printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n");
441 		printk(KERN_WARNING "GPT:%lld != %lld\n",
442 		       (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
443                        (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
444 		error_found++;
445 	}
446 	if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
447 		printk(KERN_WARNING "GPT:disk_guids don't match.\n");
448 		error_found++;
449 	}
450 	if (le32_to_cpu(pgpt->num_partition_entries) !=
451             le32_to_cpu(agpt->num_partition_entries)) {
452 		printk(KERN_WARNING "GPT:num_partition_entries don't match: "
453 		       "0x%x != 0x%x\n",
454 		       le32_to_cpu(pgpt->num_partition_entries),
455 		       le32_to_cpu(agpt->num_partition_entries));
456 		error_found++;
457 	}
458 	if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
459             le32_to_cpu(agpt->sizeof_partition_entry)) {
460 		printk(KERN_WARNING
461 		       "GPT:sizeof_partition_entry values don't match: "
462 		       "0x%x != 0x%x\n",
463                        le32_to_cpu(pgpt->sizeof_partition_entry),
464 		       le32_to_cpu(agpt->sizeof_partition_entry));
465 		error_found++;
466 	}
467 	if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
468             le32_to_cpu(agpt->partition_entry_array_crc32)) {
469 		printk(KERN_WARNING
470 		       "GPT:partition_entry_array_crc32 values don't match: "
471 		       "0x%x != 0x%x\n",
472                        le32_to_cpu(pgpt->partition_entry_array_crc32),
473 		       le32_to_cpu(agpt->partition_entry_array_crc32));
474 		error_found++;
475 	}
476 	if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
477 		printk(KERN_WARNING
478 		       "GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
479 		printk(KERN_WARNING "GPT:%lld != %lld\n",
480 			(unsigned long long)le64_to_cpu(pgpt->alternate_lba),
481 			(unsigned long long)lastlba);
482 		error_found++;
483 	}
484 
485 	if (le64_to_cpu(agpt->my_lba) != lastlba) {
486 		printk(KERN_WARNING
487 		       "GPT:Alternate GPT header not at the end of the disk.\n");
488 		printk(KERN_WARNING "GPT:%lld != %lld\n",
489 			(unsigned long long)le64_to_cpu(agpt->my_lba),
490 			(unsigned long long)lastlba);
491 		error_found++;
492 	}
493 
494 	if (error_found)
495 		printk(KERN_WARNING
496 		       "GPT: Use GNU Parted to correct GPT errors.\n");
497 	return;
498 }
499 
500 /**
501  * find_valid_gpt() - Search disk for valid GPT headers and PTEs
502  * @state
503  * @gpt is a GPT header ptr, filled on return.
504  * @ptes is a PTEs ptr, filled on return.
505  * Description: Returns 1 if valid, 0 on error.
506  * If valid, returns pointers to newly allocated GPT header and PTEs.
507  * Validity depends on PMBR being valid (or being overridden by the
508  * 'gpt' kernel command line option) and finding either the Primary
509  * GPT header and PTEs valid, or the Alternate GPT header and PTEs
510  * valid.  If the Primary GPT header is not valid, the Alternate GPT header
511  * is not checked unless the 'gpt' kernel command line option is passed.
512  * This protects against devices which misreport their size, and forces
513  * the user to decide to use the Alternate GPT.
514  */
find_valid_gpt(struct parsed_partitions * state,gpt_header ** gpt,gpt_entry ** ptes)515 static int find_valid_gpt(struct parsed_partitions *state, gpt_header **gpt,
516 			  gpt_entry **ptes)
517 {
518 	int good_pgpt = 0, good_agpt = 0, good_pmbr = 0;
519 	gpt_header *pgpt = NULL, *agpt = NULL;
520 	gpt_entry *pptes = NULL, *aptes = NULL;
521 	legacy_mbr *legacymbr;
522 	u64 lastlba;
523 
524 	if (!ptes)
525 		return 0;
526 
527 	lastlba = last_lba(state->bdev);
528         if (!force_gpt) {
529                 /* This will be added to the EFI Spec. per Intel after v1.02. */
530                 legacymbr = kzalloc(sizeof (*legacymbr), GFP_KERNEL);
531                 if (legacymbr) {
532                         read_lba(state, 0, (u8 *) legacymbr,
533 				 sizeof (*legacymbr));
534                         good_pmbr = is_pmbr_valid(legacymbr);
535                         kfree(legacymbr);
536                 }
537                 if (!good_pmbr)
538                         goto fail;
539         }
540 
541 	good_pgpt = is_gpt_valid(state, GPT_PRIMARY_PARTITION_TABLE_LBA,
542 				 &pgpt, &pptes);
543         if (good_pgpt)
544 		good_agpt = is_gpt_valid(state,
545 					 le64_to_cpu(pgpt->alternate_lba),
546 					 &agpt, &aptes);
547         if (!good_agpt && force_gpt)
548                 good_agpt = is_gpt_valid(state, lastlba, &agpt, &aptes);
549 
550         /* The obviously unsuccessful case */
551         if (!good_pgpt && !good_agpt)
552                 goto fail;
553 
554         compare_gpts(pgpt, agpt, lastlba);
555 
556         /* The good cases */
557         if (good_pgpt) {
558                 *gpt  = pgpt;
559                 *ptes = pptes;
560                 kfree(agpt);
561                 kfree(aptes);
562                 if (!good_agpt) {
563                         printk(KERN_WARNING
564 			       "Alternate GPT is invalid, "
565                                "using primary GPT.\n");
566                 }
567                 return 1;
568         }
569         else if (good_agpt) {
570                 *gpt  = agpt;
571                 *ptes = aptes;
572                 kfree(pgpt);
573                 kfree(pptes);
574                 printk(KERN_WARNING
575                        "Primary GPT is invalid, using alternate GPT.\n");
576                 return 1;
577         }
578 
579  fail:
580         kfree(pgpt);
581         kfree(agpt);
582         kfree(pptes);
583         kfree(aptes);
584         *gpt = NULL;
585         *ptes = NULL;
586         return 0;
587 }
588 
589 /**
590  * efi_partition(struct parsed_partitions *state)
591  * @state
592  *
593  * Description: called from check.c, if the disk contains GPT
594  * partitions, sets up partition entries in the kernel.
595  *
596  * If the first block on the disk is a legacy MBR,
597  * it will get handled by msdos_partition().
598  * If it's a Protective MBR, we'll handle it here.
599  *
600  * We do not create a Linux partition for GPT, but
601  * only for the actual data partitions.
602  * Returns:
603  * -1 if unable to read the partition table
604  *  0 if this isn't our partition table
605  *  1 if successful
606  *
607  */
efi_partition(struct parsed_partitions * state)608 int efi_partition(struct parsed_partitions *state)
609 {
610 	gpt_header *gpt = NULL;
611 	gpt_entry *ptes = NULL;
612 	u32 i;
613 	unsigned ssz = bdev_logical_block_size(state->bdev) / 512;
614 	u8 unparsed_guid[37];
615 
616 	if (!find_valid_gpt(state, &gpt, &ptes) || !gpt || !ptes) {
617 		kfree(gpt);
618 		kfree(ptes);
619 		return 0;
620 	}
621 
622 	pr_debug("GUID Partition Table is valid!  Yea!\n");
623 
624 	for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < state->limit-1; i++) {
625 		struct partition_meta_info *info;
626 		unsigned label_count = 0;
627 		unsigned label_max;
628 		u64 start = le64_to_cpu(ptes[i].starting_lba);
629 		u64 size = le64_to_cpu(ptes[i].ending_lba) -
630 			   le64_to_cpu(ptes[i].starting_lba) + 1ULL;
631 
632 		if (!is_pte_valid(&ptes[i], last_lba(state->bdev)))
633 			continue;
634 
635 		put_partition(state, i+1, start * ssz, size * ssz);
636 
637 		/* If this is a RAID volume, tell md */
638 		if (!efi_guidcmp(ptes[i].partition_type_guid,
639 				 PARTITION_LINUX_RAID_GUID))
640 			state->parts[i + 1].flags = ADDPART_FLAG_RAID;
641 
642 		info = &state->parts[i + 1].info;
643 		/* Instead of doing a manual swap to big endian, reuse the
644 		 * common ASCII hex format as the interim.
645 		 */
646 		efi_guid_unparse(&ptes[i].unique_partition_guid, unparsed_guid);
647 		part_pack_uuid(unparsed_guid, info->uuid);
648 
649 		/* Naively convert UTF16-LE to 7 bits. */
650 		label_max = min(sizeof(info->volname) - 1,
651 				sizeof(ptes[i].partition_name));
652 		info->volname[label_max] = 0;
653 		while (label_count < label_max) {
654 			u8 c = ptes[i].partition_name[label_count] & 0xff;
655 			if (c && !isprint(c))
656 				c = '!';
657 			info->volname[label_count] = c;
658 			label_count++;
659 		}
660 		state->parts[i + 1].has_info = true;
661 	}
662 	kfree(ptes);
663 	kfree(gpt);
664 	strlcat(state->pp_buf, "\n", PAGE_SIZE);
665 	return 1;
666 }
667