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Merge pull request #38 from marineam/cleanup

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gpt: various cleanup and error handling improvements
This commit is contained in:
Michael Marineau 2016-09-22 13:31:55 -07:00 committed by GitHub
commit d5ba259c89
3 changed files with 104 additions and 84 deletions
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2
grub-core/commands/gptprio.c
View file

@ -127,7 +127,7 @@ grub_find_next (const char *disk_name,
grub_gptprio_set_tries_left (part_found, tries_left - 1);
if (grub_gpt_update_checksums (gpt))
if (grub_gpt_update (gpt))
goto done;
if (grub_gpt_write (dev->disk, gpt))

179
grub-core/lib/gpt.c
View file

@ -32,6 +32,11 @@ GRUB_MOD_LICENSE ("GPLv3+");
static grub_uint8_t grub_gpt_magic[] = GRUB_GPT_HEADER_MAGIC;
static grub_err_t
grub_gpt_read_entries (grub_disk_t disk, grub_gpt_t gpt,
struct grub_gpt_header *header,
void **ret_entries,
grub_size_t *ret_entries_size);
char *
grub_gpt_guid_to_str (grub_gpt_guid_t *guid)
@ -373,6 +378,11 @@ grub_gpt_check_backup (grub_gpt_t gpt)
if (backup <= end)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid backup GPT LBA");
/* If both primary and backup are valid but differ prefer the primary. */
if ((gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID) &&
!grub_gpt_headers_equal (gpt))
return grub_error (GRUB_ERR_BAD_PART_TABLE, "backup GPT out of sync");
return GRUB_ERR_NONE;
}
@ -396,12 +406,21 @@ grub_gpt_read_primary (grub_disk_t disk, grub_gpt_t gpt)
return grub_errno;
gpt->status |= GRUB_GPT_PRIMARY_HEADER_VALID;
if (grub_gpt_read_entries (disk, gpt, &gpt->primary,
&gpt->entries, &gpt->entries_size))
return grub_errno;
gpt->status |= GRUB_GPT_PRIMARY_ENTRIES_VALID;
return GRUB_ERR_NONE;
}
static grub_err_t
grub_gpt_read_backup (grub_disk_t disk, grub_gpt_t gpt)
{
void *entries = NULL;
grub_size_t entries_size;
grub_uint64_t sector;
grub_disk_addr_t addr;
@ -428,18 +447,36 @@ grub_gpt_read_backup (grub_disk_t disk, grub_gpt_t gpt)
if (grub_le_to_cpu64 (gpt->backup.header_lba) != sector)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "invalid backup GPT LBA");
/* If both primary and backup are valid but differ prefer the primary. */
if ((gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID) &&
!grub_gpt_headers_equal(gpt))
return grub_error (GRUB_ERR_BAD_PART_TABLE, "backup GPT of of sync");
gpt->status |= GRUB_GPT_BACKUP_HEADER_VALID;
if (grub_gpt_read_entries (disk, gpt, &gpt->backup,
&entries, &entries_size))
return grub_errno;
if (gpt->status & GRUB_GPT_PRIMARY_ENTRIES_VALID)
{
if (entries_size != gpt->entries_size ||
grub_memcmp (entries, gpt->entries, entries_size) != 0)
return grub_error (GRUB_ERR_BAD_PART_TABLE, "backup GPT out of sync");
grub_free (entries);
}
else
{
gpt->entries = entries;
gpt->entries_size = entries_size;
}
gpt->status |= GRUB_GPT_BACKUP_ENTRIES_VALID;
return GRUB_ERR_NONE;
}
static grub_err_t
grub_gpt_read_entries (grub_disk_t disk, grub_gpt_t gpt,
struct grub_gpt_header *header)
struct grub_gpt_header *header,
void **ret_entries,
grub_size_t *ret_entries_size)
{
void *entries = NULL;
grub_uint32_t count, size, crc;
@ -481,9 +518,8 @@ grub_gpt_read_entries (grub_disk_t disk, grub_gpt_t gpt,
goto fail;
}
grub_free (gpt->entries);
gpt->entries = entries;
gpt->entries_size = entries_size;
*ret_entries = entries;
*ret_entries_size = entries_size;
return GRUB_ERR_NONE;
fail:
@ -522,30 +558,7 @@ grub_gpt_read (grub_disk_t disk)
grub_gpt_read_backup (disk, gpt);
/* If either succeeded clear any possible error from the other. */
if (gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID ||
gpt->status & GRUB_GPT_BACKUP_HEADER_VALID)
grub_errno = GRUB_ERR_NONE;
else
goto fail;
/* Similarly, favor the value or error from the primary table. */
if (gpt->status & GRUB_GPT_BACKUP_HEADER_VALID &&
!grub_gpt_read_entries (disk, gpt, &gpt->backup))
{
grub_dprintf ("gpt", "read valid backup GPT from %s\n", disk->name);
gpt->status |= GRUB_GPT_BACKUP_ENTRIES_VALID;
}
grub_errno = GRUB_ERR_NONE;
if (gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID &&
!grub_gpt_read_entries (disk, gpt, &gpt->primary))
{
grub_dprintf ("gpt", "read valid primary GPT from %s\n", disk->name);
gpt->status |= GRUB_GPT_PRIMARY_ENTRIES_VALID;
}
if (gpt->status & GRUB_GPT_PRIMARY_ENTRIES_VALID ||
gpt->status & GRUB_GPT_BACKUP_ENTRIES_VALID)
if (grub_gpt_primary_valid (gpt) || grub_gpt_backup_valid (gpt))
grub_errno = GRUB_ERR_NONE;
else
goto fail;
@ -577,8 +590,6 @@ grub_gpt_get_partentry (grub_gpt_t gpt, grub_uint32_t n)
grub_err_t
grub_gpt_repair (grub_disk_t disk, grub_gpt_t gpt)
{
grub_uint64_t backup_header, backup_entries;
/* Skip if there is nothing to do. */
if (grub_gpt_both_valid (gpt))
return GRUB_ERR_NONE;
@ -589,71 +600,61 @@ grub_gpt_repair (grub_disk_t disk, grub_gpt_t gpt)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"GPT sector size must match disk sector size");
if (!(gpt->status & GRUB_GPT_PRIMARY_ENTRIES_VALID ||
gpt->status & GRUB_GPT_BACKUP_ENTRIES_VALID))
return grub_error (GRUB_ERR_BUG, "No valid GPT entries");
if (grub_gpt_primary_valid (gpt))
{
grub_uint64_t backup_header;
if (gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID)
{
grub_dprintf ("gpt", "primary GPT header is valid\n");
grub_dprintf ("gpt", "primary GPT is valid\n");
/* Relocate backup to end if disk if the disk has grown. */
backup_header = grub_le_to_cpu64 (gpt->primary.alternate_lba);
if (grub_gpt_disk_size_valid (disk) &&
disk->total_sectors - 1 > backup_header)
{
backup_header = disk->total_sectors - 1;
grub_dprintf ("gpt", "backup GPT header relocated to 0x%llx\n",
(unsigned long long) backup_header);
gpt->primary.alternate_lba = grub_cpu_to_le64 (backup_header);
}
grub_memcpy (&gpt->backup, &gpt->primary, sizeof (gpt->backup));
gpt->backup.header_lba = gpt->primary.alternate_lba;
gpt->backup.alternate_lba = gpt->primary.header_lba;
gpt->backup.partitions = grub_cpu_to_le64 (backup_header -
grub_gpt_size_to_sectors (gpt, gpt->entries_size));
}
else if (gpt->status & GRUB_GPT_BACKUP_HEADER_VALID)
else if (grub_gpt_backup_valid (gpt))
{
grub_dprintf ("gpt", "backup GPT header is valid\n");
backup_header = grub_le_to_cpu64 (gpt->backup.header_lba);
grub_dprintf ("gpt", "backup GPT is valid\n");
grub_memcpy (&gpt->primary, &gpt->backup, sizeof (gpt->primary));
gpt->primary.header_lba = gpt->backup.alternate_lba;
gpt->primary.alternate_lba = gpt->backup.header_lba;
gpt->primary.partitions = grub_cpu_to_le64_compile_time (2);
}
else
return grub_error (GRUB_ERR_BUG, "No valid GPT header");
return grub_error (GRUB_ERR_BUG, "No valid GPT");
/* Relocate backup to end if disk whenever possible. */
if (grub_gpt_disk_size_valid(disk))
backup_header = disk->total_sectors - 1;
grub_dprintf ("gpt", "backup GPT header will be located at 0x%llx\n",
(unsigned long long) backup_header);
backup_entries = backup_header -
grub_gpt_size_to_sectors (gpt, gpt->entries_size);
grub_dprintf ("gpt", "backup GPT entries will be located at 0x%llx\n",
(unsigned long long) backup_entries);
/* Update/fixup header and partition table locations. */
gpt->primary.header_lba = grub_cpu_to_le64_compile_time (1);
gpt->primary.alternate_lba = grub_cpu_to_le64 (backup_header);
gpt->primary.partitions = grub_cpu_to_le64_compile_time (2);
gpt->backup.header_lba = gpt->primary.alternate_lba;
gpt->backup.alternate_lba = gpt->primary.header_lba;
gpt->backup.partitions = grub_cpu_to_le64 (backup_entries);
/* Recompute checksums. */
if (grub_gpt_update_checksums (gpt))
if (grub_gpt_update (gpt))
return grub_errno;
/* Sanity check. */
if (grub_gpt_check_primary (gpt))
return grub_error (GRUB_ERR_BUG, "Generated invalid GPT primary header");
gpt->status |= (GRUB_GPT_PRIMARY_HEADER_VALID |
GRUB_GPT_PRIMARY_ENTRIES_VALID);
if (grub_gpt_check_backup (gpt))
return grub_error (GRUB_ERR_BUG, "Generated invalid GPT backup header");
gpt->status |= (GRUB_GPT_BACKUP_HEADER_VALID |
GRUB_GPT_BACKUP_ENTRIES_VALID);
grub_dprintf ("gpt", "repairing GPT for %s successful\n", disk->name);
return GRUB_ERR_NONE;
}
grub_err_t
grub_gpt_update_checksums (grub_gpt_t gpt)
grub_gpt_update (grub_gpt_t gpt)
{
grub_uint32_t crc;
/* Clear status bits, require revalidation of everything. */
gpt->status &= ~(GRUB_GPT_PRIMARY_HEADER_VALID |
GRUB_GPT_PRIMARY_ENTRIES_VALID |
GRUB_GPT_BACKUP_HEADER_VALID |
GRUB_GPT_BACKUP_ENTRIES_VALID);
/* Writing headers larger than our header structure are unsupported. */
gpt->primary.headersize =
grub_cpu_to_le32_compile_time (sizeof (gpt->primary));
@ -667,6 +668,24 @@ grub_gpt_update_checksums (grub_gpt_t gpt)
grub_gpt_header_lecrc32 (&gpt->primary.crc32, &gpt->primary);
grub_gpt_header_lecrc32 (&gpt->backup.crc32, &gpt->backup);
if (grub_gpt_check_primary (gpt))
{
grub_error_push ();
return grub_error (GRUB_ERR_BUG, "Generated invalid GPT primary header");
}
gpt->status |= (GRUB_GPT_PRIMARY_HEADER_VALID |
GRUB_GPT_PRIMARY_ENTRIES_VALID);
if (grub_gpt_check_backup (gpt))
{
grub_error_push ();
return grub_error (GRUB_ERR_BUG, "Generated invalid GPT backup header");
}
gpt->status |= (GRUB_GPT_BACKUP_HEADER_VALID |
GRUB_GPT_BACKUP_ENTRIES_VALID);
return GRUB_ERR_NONE;
}

7
include/grub/gpt_partition.h
View file

@ -232,11 +232,12 @@ grub_gpt_t grub_gpt_read (grub_disk_t disk);
struct grub_gpt_partentry * grub_gpt_get_partentry (grub_gpt_t gpt,
grub_uint32_t n);
/* Sync up primary and backup headers, recompute checksums. */
/* Sync and update primary and backup headers if either are invalid. */
grub_err_t grub_gpt_repair (grub_disk_t disk, grub_gpt_t gpt);
/* Recompute checksums, must be called after modifying GPT data. */
grub_err_t grub_gpt_update_checksums (grub_gpt_t gpt);
/* Recompute checksums and revalidate everything, must be called after
* modifying any GPT data. */
grub_err_t grub_gpt_update (grub_gpt_t gpt);
/* Write headers and entry tables back to disk. */
grub_err_t grub_gpt_write (grub_disk_t disk, grub_gpt_t gpt);