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0006-gpt-add-new-repair-function-to-sync-up-primary-and-b.patch
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0006-gpt-add-new-repair-function-to-sync-up-primary-and-b.patch
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From 36fc577048523438ffbf51291a40fe59eb479724 Mon Sep 17 00:00:00 2001
From: Michael Marineau <michael.marineau@coreos.com>
Date: Sat, 18 Oct 2014 18:21:07 -0700
Subject: [PATCH] gpt: add new repair function to sync up primary and backup
tables.
---
grub-core/lib/gpt.c | 90 ++++++++++++++++++++++++++++++++++++
include/grub/gpt_partition.h | 3 ++
tests/gpt_unit_test.c | 49 ++++++++++++++++++++
3 files changed, 142 insertions(+)
diff --git a/grub-core/lib/gpt.c b/grub-core/lib/gpt.c
index 43a1509..2d61df4 100644
--- a/grub-core/lib/gpt.c
+++ b/grub-core/lib/gpt.c
@@ -31,6 +31,20 @@ GRUB_MOD_LICENSE ("GPLv3+");
static grub_uint8_t grub_gpt_magic[] = GRUB_GPT_HEADER_MAGIC;
+static grub_uint64_t
+grub_gpt_size_to_sectors (grub_gpt_t gpt, grub_size_t size)
+{
+ unsigned int sector_size;
+ grub_uint64_t sectors;
+
+ sector_size = 1U << gpt->log_sector_size;
+ sectors = size / sector_size;
+ if (size % sector_size)
+ sectors++;
+
+ return sectors;
+}
+
static grub_err_t
grub_gpt_lecrc32 (void *data, grub_size_t len, grub_uint32_t *crc)
{
@@ -275,6 +289,82 @@ fail:
return NULL;
}
+grub_err_t
+grub_gpt_repair (grub_disk_t disk, grub_gpt_t gpt)
+{
+ grub_uint64_t backup_header, backup_entries;
+ grub_uint32_t crc;
+
+ if (disk->log_sector_size != gpt->log_sector_size)
+ 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 (gpt->status & GRUB_GPT_PRIMARY_HEADER_VALID)
+ {
+ backup_header = grub_le_to_cpu64 (gpt->primary.alternate_lba);
+ grub_memcpy (&gpt->backup, &gpt->primary, sizeof (gpt->backup));
+ }
+ else if (gpt->status & GRUB_GPT_BACKUP_HEADER_VALID)
+ {
+ backup_header = grub_le_to_cpu64 (gpt->backup.header_lba);
+ grub_memcpy (&gpt->primary, &gpt->backup, sizeof (gpt->primary));
+ }
+ else
+ return grub_error (GRUB_ERR_BUG, "No valid GPT header");
+
+ /* Relocate backup to end if disk whenever possible. */
+ if (disk->total_sectors != GRUB_DISK_SIZE_UNKNOWN)
+ backup_header = disk->total_sectors - 1;
+
+ backup_entries = backup_header -
+ grub_gpt_size_to_sectors (gpt, gpt->entries_size);
+
+ /* 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);
+
+ /* Writing headers larger than our header structure are unsupported. */
+ gpt->primary.headersize =
+ grub_cpu_to_le32_compile_time (sizeof (gpt->primary));
+ gpt->backup.headersize =
+ grub_cpu_to_le32_compile_time (sizeof (gpt->backup));
+
+ /* Recompute checksums. */
+ if (grub_gpt_lecrc32 (gpt->entries, gpt->entries_size, &crc))
+ return grub_errno;
+
+ gpt->primary.partentry_crc32 = crc;
+ gpt->backup.partentry_crc32 = crc;
+
+ if (grub_gpt_header_lecrc32 (&gpt->primary, &gpt->primary.crc32))
+ return grub_errno;
+
+ if (grub_gpt_header_lecrc32 (&gpt->backup, &gpt->backup.crc32))
+ return grub_errno;
+
+ /* Sanity check. */
+ if (grub_gpt_header_check (&gpt->primary, gpt->log_sector_size))
+ return grub_error (GRUB_ERR_BUG, "Generated invalid GPT primary header");
+
+ if (grub_gpt_header_check (&gpt->backup, gpt->log_sector_size))
+ return grub_error (GRUB_ERR_BUG, "Generated invalid GPT backup header");
+
+ gpt->status |= (GRUB_GPT_PRIMARY_HEADER_VALID |
+ GRUB_GPT_PRIMARY_ENTRIES_VALID |
+ GRUB_GPT_BACKUP_HEADER_VALID |
+ GRUB_GPT_BACKUP_ENTRIES_VALID);
+
+ return GRUB_ERR_NONE;
+}
+
void
grub_gpt_free (grub_gpt_t gpt)
{
diff --git a/include/grub/gpt_partition.h b/include/grub/gpt_partition.h
index 21ea08d..b45acbd 100644
--- a/include/grub/gpt_partition.h
+++ b/include/grub/gpt_partition.h
@@ -141,6 +141,9 @@ grub_gpt_sector_to_addr (grub_gpt_t gpt, grub_uint64_t sector)
/* Allocates and fills new grub_gpt structure, free with grub_gpt_free. */
grub_gpt_t grub_gpt_read (grub_disk_t disk);
+/* Sync up primary and backup headers, recompute checksums. */
+grub_err_t grub_gpt_repair (grub_disk_t disk, grub_gpt_t gpt);
+
void grub_gpt_free (grub_gpt_t gpt);
grub_err_t grub_gpt_pmbr_check (struct grub_msdos_partition_mbr *mbr);
diff --git a/tests/gpt_unit_test.c b/tests/gpt_unit_test.c
index 4d70868..83198be 100644
--- a/tests/gpt_unit_test.c
+++ b/tests/gpt_unit_test.c
@@ -24,6 +24,7 @@
#include <grub/err.h>
#include <grub/gpt_partition.h>
#include <grub/msdos_partition.h>
+#include <grub/lib/hexdump.h>
#include <grub/test.h>
#include <errno.h>
@@ -442,6 +443,52 @@ read_fallback_test (void)
close_disk (&data);
}
+static void
+repair_test (void)
+{
+ struct test_data data;
+ grub_gpt_t gpt;
+
+ open_disk (&data);
+
+ /* Erase/Repair primary. */
+ memset (&data.raw->primary_header, 0, sizeof (data.raw->primary_header));
+ sync_disk (&data);
+ gpt = read_disk (&data);
+ grub_gpt_repair (data.dev->disk, gpt);
+ grub_test_assert (grub_errno == GRUB_ERR_NONE,
+ "repair failed: %s", grub_errmsg);
+ if (memcmp (&gpt->primary, &example_primary, sizeof (gpt->primary)))
+ {
+ printf ("Invalid restored primary header:\n");
+ hexdump (16, (char*)&gpt->primary, sizeof (gpt->primary));
+ printf ("Expected primary header:\n");
+ hexdump (16, (char*)&example_primary, sizeof (example_primary));
+ grub_test_assert (0, "repair did not restore primary header");
+ }
+ grub_gpt_free (gpt);
+ reset_disk (&data);
+
+ /* Erase/Repair backup. */
+ memset (&data.raw->backup_header, 0, sizeof (data.raw->backup_header));
+ sync_disk (&data);
+ gpt = read_disk (&data);
+ grub_gpt_repair (data.dev->disk, gpt);
+ grub_test_assert (grub_errno == GRUB_ERR_NONE,
+ "repair failed: %s", grub_errmsg);
+ if (memcmp (&gpt->backup, &example_backup, sizeof (gpt->backup)))
+ {
+ printf ("Invalid restored backup header:\n");
+ hexdump (16, (char*)&gpt->backup, sizeof (gpt->backup));
+ printf ("Expected backup header:\n");
+ hexdump (16, (char*)&example_backup, sizeof (example_backup));
+ grub_test_assert (0, "repair did not restore backup header");
+ }
+ grub_gpt_free (gpt);
+ reset_disk (&data);
+
+ close_disk (&data);
+}
void
grub_unit_test_init (void)
{
@@ -453,6 +500,7 @@ grub_unit_test_init (void)
grub_test_register ("gpt_read_valid_test", read_valid_test);
grub_test_register ("gpt_read_invalid_test", read_invalid_entries_test);
grub_test_register ("gpt_read_fallback_test", read_fallback_test);
+ grub_test_register ("gpt_repair_test", repair_test);
}
void
@@ -463,5 +511,6 @@ grub_unit_test_fini (void)
grub_test_unregister ("gpt_read_valid_test");
grub_test_unregister ("gpt_read_invalid_test");
grub_test_unregister ("gpt_read_fallback_test");
+ grub_test_unregister ("gpt_repair_test");
grub_fini_all ();
}
--
2.21.3