partitions/efi: account for pmbr size in lba (27a7c642) · Commits · 戴 / test

block/partitions/efi.c

+18 −3

Original line number	Diff line number	Diff line
		@@ -166,6 +166,7 @@ invalid:
		/**
		* is_pmbr_valid(): test Protective MBR for validity
		* @mbr: pointer to a legacy mbr structure
		* @total_sectors: amount of sectors in the device
		*
		* Description: Checks for a valid protective or hybrid
		* master boot record (MBR). The validity of a pMBR depends
		@@ -180,9 +181,9 @@ invalid:
		* Returns 0 upon invalid MBR, or GPT_MBR_PROTECTIVE or
		* GPT_MBR_HYBRID depending on the device layout.
		*/
		static int is_pmbr_valid(legacy_mbr *mbr)
		static int is_pmbr_valid(legacy_mbr *mbr, sector_t total_sectors)
		{
		int i, ret = 0; /* invalid by default */
		int i, part = 0, ret = 0; /* invalid by default */

		if (!mbr \|\| le16_to_cpu(mbr->signature) != MSDOS_MBR_SIGNATURE)
		goto done;
		@@ -190,6 +191,7 @@ static int is_pmbr_valid(legacy_mbr *mbr)
		for (i = 0; i < 4; i++) {
		ret = pmbr_part_valid(&mbr->partition_record[i]);
		if (ret == GPT_MBR_PROTECTIVE) {
		part = i;
		/*
		* Ok, we at least know that there's a protective MBR,
		* now check if there are other partition types for
		@@ -207,6 +209,18 @@ check_hybrid:
		EFI_PMBR_OSTYPE_EFI_GPT) &&
		(mbr->partition_record[i].os_type != 0x00))
		ret = GPT_MBR_HYBRID;

		/*
		* Protective MBRs take up the lesser of the whole disk
		* or 2 TiB (32bit LBA), ignoring the rest of the disk.
		*
		* Hybrid MBRs do not necessarily comply with this.
		*/
		if (ret == GPT_MBR_PROTECTIVE) {
		if (le32_to_cpu(mbr->partition_record[part].size_in_lba) !=
		min((uint32_t) total_sectors - 1, 0xFFFFFFFF))
		ret = 0;
		}
		done:
		return ret;
		}
		@@ -568,6 +582,7 @@ static int find_valid_gpt(struct parsed_partitions state, gpt_header *gpt,
		gpt_header pgpt = NULL, agpt = NULL;
		gpt_entry pptes = NULL, aptes = NULL;
		legacy_mbr *legacymbr;
		sector_t total_sectors = i_size_read(state->bdev->bd_inode) >> 9;
		u64 lastlba;

		if (!ptes)
		@@ -581,7 +596,7 @@ static int find_valid_gpt(struct parsed_partitions state, gpt_header *gpt,
		goto fail;

		read_lba(state, 0, (u8 )legacymbr, sizeof(legacymbr));
		good_pmbr = is_pmbr_valid(legacymbr);
		good_pmbr = is_pmbr_valid(legacymbr, total_sectors);
		kfree(legacymbr);

		if (!good_pmbr)

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