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-rw-r--r--common/partitions/efi.c477
1 files changed, 477 insertions, 0 deletions
diff --git a/common/partitions/efi.c b/common/partitions/efi.c
new file mode 100644
index 0000000000..e450eebf77
--- /dev/null
+++ b/common/partitions/efi.c
@@ -0,0 +1,477 @@
+/************************************************************
+ * EFI GUID Partition Table handling
+ *
+ * http://www.uefi.org/specs/
+ * http://www.intel.com/technology/efi/
+ *
+ * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com>
+ * Copyright 2000,2001,2002,2004 Dell Inc.
+ *
+ * Copyright (C) 2013 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ *
+ * Under GPLv2 only
+ */
+
+#include <common.h>
+#include <disks.h>
+#include <init.h>
+#include <asm/unaligned.h>
+#include <dma.h>
+#include <linux/ctype.h>
+
+#include "efi.h"
+#include "parser.h"
+
+static int force_gpt = IS_ENABLED(CONFIG_PARTITION_DISK_EFI_GPT_NO_FORCE);
+
+/**
+ * efi_crc32() - EFI version of crc32 function
+ * @buf: buffer to calculate crc32 of
+ * @len - length of buf
+ *
+ * Description: Returns EFI-style CRC32 value for @buf
+ *
+ * This function uses the little endian Ethernet polynomial
+ * but seeds the function with ~0, and xor's with ~0 at the end.
+ * Note, the EFI Specification, v1.02, has a reference to
+ * Dr. Dobbs Journal, May 1994 (actually it's in May 1992).
+ */
+static inline u32
+efi_crc32(const void *buf, unsigned long len)
+{
+ return crc32(0, buf, len);
+}
+
+/**
+ * last_lba(): return number of last logical block of device
+ * @bdev: block device
+ *
+ * Description: Returns last LBA value on success, 0 on error.
+ * This is stored (by sd and ide-geometry) in
+ * the part[0] entry for this disk, and is the number of
+ * physical sectors available on the disk.
+ */
+static u64 last_lba(struct block_device *bdev)
+{
+ if (!bdev)
+ return 0;
+ return bdev->num_blocks;
+}
+
+/**
+ * alloc_read_gpt_entries(): reads partition entries from disk
+ * @dev_desc
+ * @gpt - GPT header
+ *
+ * Description: Returns ptes on success, NULL on error.
+ * Allocates space for PTEs based on information found in @gpt.
+ * Notes: remember to free pte when you're done!
+ */
+static gpt_entry *alloc_read_gpt_entries(struct block_device *blk,
+ gpt_header * pgpt_head)
+{
+ size_t count = 0;
+ gpt_entry *pte = NULL;
+ unsigned long from, size;
+ int ret;
+
+ count = le32_to_cpu(pgpt_head->num_partition_entries) *
+ le32_to_cpu(pgpt_head->sizeof_partition_entry);
+
+ if (!count)
+ return NULL;
+ pte = kzalloc(count, GFP_KERNEL);
+ if (!pte)
+ return NULL;
+
+ from = le64_to_cpu(pgpt_head->partition_entry_lba);
+ size = count / GPT_BLOCK_SIZE;
+ ret = blk->ops->read(blk, pte, from, size);
+ if (ret) {
+ kfree(pte);
+ pte=NULL;
+ return NULL;
+ }
+ return pte;
+}
+
+static inline unsigned short bdev_logical_block_size(struct block_device
+*bdev)
+{
+ return SECTOR_SIZE;
+}
+
+/**
+ * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk
+ * @state
+ * @lba is the Logical Block Address of the partition table
+ *
+ * Description: returns GPT header on success, NULL on error. Allocates
+ * and fills a GPT header starting at @ from @state->bdev.
+ * Note: remember to free gpt when finished with it.
+ */
+static gpt_header *alloc_read_gpt_header(struct block_device *blk,
+ u64 lba)
+{
+ gpt_header *gpt;
+ unsigned ssz = bdev_logical_block_size(blk);
+ int ret;
+
+ gpt = kzalloc(ssz, GFP_KERNEL);
+ if (!gpt)
+ return NULL;
+
+ ret = blk->ops->read(blk, gpt, lba, 1);
+ if (ret) {
+ kfree(gpt);
+ gpt=NULL;
+ return NULL;
+ }
+
+ return gpt;
+}
+
+/**
+ * is_gpt_valid() - tests one GPT header and PTEs for validity
+ *
+ * lba is the logical block address of the GPT header to test
+ * gpt is a GPT header ptr, filled on return.
+ * ptes is a PTEs ptr, filled on return.
+ *
+ * Description: returns 1 if valid, 0 on error.
+ * If valid, returns pointers to PTEs.
+ */
+static int is_gpt_valid(struct block_device *blk, u64 lba,
+ gpt_header **gpt, gpt_entry **ptes)
+{
+ u32 crc, origcrc;
+ u64 lastlba;
+
+ if (!ptes)
+ return 0;
+ if (!(*gpt = alloc_read_gpt_header(blk, lba)))
+ return 0;
+
+ /* Check the GPT header signature */
+ if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) {
+ dev_dbg(blk->dev, "GUID Partition Table Header signature is wrong:"
+ "0x%llX != 0x%llX\n",
+ (unsigned long long)le64_to_cpu((*gpt)->signature),
+ (unsigned long long)GPT_HEADER_SIGNATURE);
+ goto fail;
+ }
+
+ /* Check the GUID Partition Table CRC */
+ origcrc = le32_to_cpu((*gpt)->header_crc32);
+ (*gpt)->header_crc32 = 0;
+ crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
+
+ if (crc != origcrc) {
+ dev_dbg(blk->dev, "GUID Partition Table Header CRC is wrong: %x != %x\n",
+ crc, origcrc);
+ goto fail;
+ }
+ (*gpt)->header_crc32 = cpu_to_le32(origcrc);
+
+ /* Check that the my_lba entry points to the LBA that contains
+ * the GUID Partition Table */
+ if (le64_to_cpu((*gpt)->my_lba) != lba) {
+ dev_dbg(blk->dev, "GPT: my_lba incorrect: %llX != %llX\n",
+ (unsigned long long)le64_to_cpu((*gpt)->my_lba),
+ (unsigned long long)lba);
+ goto fail;
+ }
+
+ /* Check the first_usable_lba and last_usable_lba are within the disk. */
+ lastlba = last_lba(blk);
+ if (le64_to_cpu((*gpt)->first_usable_lba) > lastlba) {
+ dev_dbg(blk->dev, "GPT: first_usable_lba incorrect: %lld > %lld\n",
+ (unsigned long long)le64_to_cpu((*gpt)->first_usable_lba),
+ (unsigned long long)lastlba);
+ goto fail;
+ }
+ if (le64_to_cpu((*gpt)->last_usable_lba) > lastlba) {
+ dev_dbg(blk->dev, "GPT: last_usable_lba incorrect: %lld > %lld\n",
+ (unsigned long long)le64_to_cpu((*gpt)->last_usable_lba),
+ (unsigned long long)lastlba);
+ goto fail;
+ }
+
+ if (!(*ptes = alloc_read_gpt_entries(blk, *gpt)))
+ goto fail;
+
+ /* Check the GUID Partition Table Entry Array CRC */
+ crc = efi_crc32((const unsigned char *)*ptes,
+ le32_to_cpu((*gpt)->num_partition_entries) *
+ le32_to_cpu((*gpt)->sizeof_partition_entry));
+
+ if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
+ dev_dbg(blk->dev, "GUID Partitition Entry Array CRC check failed.\n");
+ goto fail_ptes;
+ }
+
+ /* We're done, all's well */
+ return 1;
+
+ fail_ptes:
+ kfree(*ptes);
+ *ptes = NULL;
+ fail:
+ kfree(*gpt);
+ *gpt = NULL;
+ return 0;
+}
+
+/**
+ * is_pte_valid() - tests one PTE for validity
+ * @pte is the pte to check
+ * @lastlba is last lba of the disk
+ *
+ * Description: returns 1 if valid, 0 on error.
+ */
+static inline int
+is_pte_valid(const gpt_entry *pte, const u64 lastlba)
+{
+ if ((!efi_guidcmp(pte->partition_type_guid, NULL_GUID)) ||
+ le64_to_cpu(pte->starting_lba) > lastlba ||
+ le64_to_cpu(pte->ending_lba) > lastlba)
+ return 0;
+ return 1;
+}
+
+/**
+ * compare_gpts() - Search disk for valid GPT headers and PTEs
+ * @pgpt is the primary GPT header
+ * @agpt is the alternate GPT header
+ * @lastlba is the last LBA number
+ * Description: Returns nothing. Sanity checks pgpt and agpt fields
+ * and prints warnings on discrepancies.
+ *
+ */
+static void
+compare_gpts(struct device_d *dev, gpt_header *pgpt, gpt_header *agpt, u64 lastlba)
+{
+ int error_found = 0;
+ if (!pgpt || !agpt)
+ return;
+ if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) {
+ dev_warn(dev,
+ "GPT:Primary header LBA != Alt. header alternate_lba\n");
+ dev_warn(dev, "GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->my_lba),
+ (unsigned long long)le64_to_cpu(agpt->alternate_lba));
+ error_found++;
+ }
+ if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) {
+ dev_warn(dev,
+ "GPT:Primary header alternate_lba != Alt. header my_lba\n");
+ dev_warn(dev, "GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
+ (unsigned long long)le64_to_cpu(agpt->my_lba));
+ error_found++;
+ }
+ if (le64_to_cpu(pgpt->first_usable_lba) !=
+ le64_to_cpu(agpt->first_usable_lba)) {
+ dev_warn(dev, "GPT:first_usable_lbas don't match.\n");
+ dev_warn(dev, "GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->first_usable_lba),
+ (unsigned long long)le64_to_cpu(agpt->first_usable_lba));
+ error_found++;
+ }
+ if (le64_to_cpu(pgpt->last_usable_lba) !=
+ le64_to_cpu(agpt->last_usable_lba)) {
+ dev_warn(dev, "GPT:last_usable_lbas don't match.\n");
+ dev_warn(dev, "GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->last_usable_lba),
+ (unsigned long long)le64_to_cpu(agpt->last_usable_lba));
+ error_found++;
+ }
+ if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) {
+ dev_warn(dev, "GPT:disk_guids don't match.\n");
+ error_found++;
+ }
+ if (le32_to_cpu(pgpt->num_partition_entries) !=
+ le32_to_cpu(agpt->num_partition_entries)) {
+ dev_warn(dev, "GPT:num_partition_entries don't match: "
+ "0x%x != 0x%x\n",
+ le32_to_cpu(pgpt->num_partition_entries),
+ le32_to_cpu(agpt->num_partition_entries));
+ error_found++;
+ }
+ if (le32_to_cpu(pgpt->sizeof_partition_entry) !=
+ le32_to_cpu(agpt->sizeof_partition_entry)) {
+ dev_warn(dev,
+ "GPT:sizeof_partition_entry values don't match: "
+ "0x%x != 0x%x\n",
+ le32_to_cpu(pgpt->sizeof_partition_entry),
+ le32_to_cpu(agpt->sizeof_partition_entry));
+ error_found++;
+ }
+ if (le32_to_cpu(pgpt->partition_entry_array_crc32) !=
+ le32_to_cpu(agpt->partition_entry_array_crc32)) {
+ dev_warn(dev,
+ "GPT:partition_entry_array_crc32 values don't match: "
+ "0x%x != 0x%x\n",
+ le32_to_cpu(pgpt->partition_entry_array_crc32),
+ le32_to_cpu(agpt->partition_entry_array_crc32));
+ error_found++;
+ }
+ if (le64_to_cpu(pgpt->alternate_lba) != lastlba) {
+ dev_warn(dev,
+ "GPT:Primary header thinks Alt. header is not at the end of the disk.\n");
+ dev_warn(dev, "GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(pgpt->alternate_lba),
+ (unsigned long long)lastlba);
+ error_found++;
+ }
+
+ if (le64_to_cpu(agpt->my_lba) != lastlba) {
+ dev_warn(dev,
+ "GPT:Alternate GPT header not at the end of the disk.\n");
+ dev_warn(dev, "GPT:%lld != %lld\n",
+ (unsigned long long)le64_to_cpu(agpt->my_lba),
+ (unsigned long long)lastlba);
+ error_found++;
+ }
+
+ if (error_found)
+ dev_warn(dev, "GPT: Use GNU Parted to correct GPT errors.\n");
+ return;
+}
+
+/**
+ * find_valid_gpt() - Search disk for valid GPT headers and PTEs
+ * @state
+ * @gpt is a GPT header ptr, filled on return.
+ * @ptes is a PTEs ptr, filled on return.
+ * Description: Returns 1 if valid, 0 on error.
+ * If valid, returns pointers to newly allocated GPT header and PTEs.
+ * Validity depends on PMBR being valid (or being overridden by the
+ * 'gpt' kernel command line option) and finding either the Primary
+ * GPT header and PTEs valid, or the Alternate GPT header and PTEs
+ * valid. If the Primary GPT header is not valid, the Alternate GPT header
+ * is not checked unless the 'gpt' kernel command line option is passed.
+ * This protects against devices which misreport their size, and forces
+ * the user to decide to use the Alternate GPT.
+ */
+static int find_valid_gpt(void *buf, struct block_device *blk, gpt_header **gpt,
+ gpt_entry **ptes)
+{
+ int good_pgpt = 0, good_agpt = 0;
+ gpt_header *pgpt = NULL, *agpt = NULL;
+ gpt_entry *pptes = NULL, *aptes = NULL;
+ u64 lastlba;
+
+ if (!ptes)
+ return 0;
+
+ lastlba = last_lba(blk);
+ if (force_gpt) {
+ /* This will be added to the EFI Spec. per Intel after v1.02. */
+ if (file_detect_type(buf, SECTOR_SIZE * 2) != filetype_gpt)
+ goto fail;
+ }
+
+ good_pgpt = is_gpt_valid(blk, GPT_PRIMARY_PARTITION_TABLE_LBA,
+ &pgpt, &pptes);
+ if (good_pgpt)
+ good_agpt = is_gpt_valid(blk,
+ le64_to_cpu(pgpt->alternate_lba),
+ &agpt, &aptes);
+ if (!good_agpt && force_gpt)
+ good_agpt = is_gpt_valid(blk, lastlba, &agpt, &aptes);
+
+ /* The obviously unsuccessful case */
+ if (!good_pgpt && !good_agpt)
+ goto fail;
+
+ if (IS_ENABLED(CONFIG_PARTITION_DISK_EFI_GPT_COMPARE))
+ compare_gpts(blk->dev, pgpt, agpt, lastlba);
+
+ /* The good cases */
+ if (good_pgpt) {
+ *gpt = pgpt;
+ *ptes = pptes;
+ kfree(agpt);
+ kfree(aptes);
+ if (!good_agpt)
+ dev_warn(blk->dev, "Alternate GPT is invalid, using primary GPT.\n");
+ return 1;
+ }
+ else if (good_agpt) {
+ *gpt = agpt;
+ *ptes = aptes;
+ kfree(pgpt);
+ kfree(pptes);
+ dev_warn(blk->dev, "Primary GPT is invalid, using alternate GPT.\n");
+ return 1;
+ }
+
+ fail:
+ kfree(pgpt);
+ kfree(agpt);
+ kfree(pptes);
+ kfree(aptes);
+ *gpt = NULL;
+ *ptes = NULL;
+ return 0;
+}
+
+static void part_set_efi_name(gpt_entry *pte, char *dest)
+{
+ int i;
+
+ for (i = 0; i < GPT_PARTNAME_MAX_SIZE ; i++) {
+ u8 c;
+ c = pte->partition_name[i] & 0xff;
+ c = (c && !isprint(c)) ? '.' : c;
+ dest[i] = c;
+ }
+ dest[i] = 0;
+}
+
+static void efi_partition(void *buf, struct block_device *blk,
+ struct partition_desc *pd)
+{
+ gpt_header *gpt = NULL;
+ gpt_entry *ptes = NULL;
+ int i = 0;
+ int nb_part;
+ struct partition *pentry;
+
+ if (!find_valid_gpt(buf, blk, &gpt, &ptes) || !gpt || !ptes) {
+ kfree(gpt);
+ kfree(ptes);
+ return;
+ }
+
+ nb_part = le32_to_cpu(gpt->num_partition_entries);
+ for (i = 0; i < MAX_PARTITION && i < nb_part; i++) {
+ if (!is_pte_valid(&ptes[i], last_lba(blk))) {
+ dev_dbg(blk->dev, "Invalid pte %d\n", i);
+ return;
+ }
+
+ pentry = &pd->parts[pd->used_entries];
+ pentry->first_sec = le64_to_cpu(ptes[i].starting_lba);
+ pentry->size = le64_to_cpu(ptes[i].ending_lba) - pentry->first_sec;
+ pentry->size++;
+ part_set_efi_name(&ptes[i], pentry->name);
+ pd->used_entries++;
+ }
+
+ if (i > MAX_PARTITION)
+ dev_warn(blk->dev, "num_partition_entries (%d) > max partition number (%d)\n",
+ nb_part, MAX_PARTITION);
+}
+
+static struct partition_parser efi_partition_parser = {
+ .parse = efi_partition,
+ .type = filetype_gpt,
+};
+
+static int efi_partition_init(void)
+{
+ return partition_parser_register(&efi_partition_parser);
+}
+postconsole_initcall(efi_partition_init);
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-24 03:23:54 +0000