UPSTREAM: dm verity: factor out structures and functions useful to separate object (2baabee2) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/md/dm-verity-target.c

+16 −101

Original line number	Diff line number	Diff line
		@@ -14,12 +14,10 @@
		* access behavior.
		*/

		#include "dm-bufio.h"
		#include "dm-verity.h"

		#include <linux/module.h>
		#include <linux/device-mapper.h>
		#include <linux/reboot.h>
		#include <crypto/hash.h>

		#define DM_MSG_PREFIX "verity"

		@@ -28,7 +26,6 @@

		#define DM_VERITY_DEFAULT_PREFETCH_SIZE 262144

		#define DM_VERITY_MAX_LEVELS 63
		#define DM_VERITY_MAX_CORRUPTED_ERRS 100

		#define DM_VERITY_OPT_LOGGING "ignore_corruption"
		@@ -40,73 +37,6 @@ static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE;

		module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO \| S_IWUSR);

		enum verity_mode {
		DM_VERITY_MODE_EIO,
		DM_VERITY_MODE_LOGGING,
		DM_VERITY_MODE_RESTART
		};

		enum verity_block_type {
		DM_VERITY_BLOCK_TYPE_DATA,
		DM_VERITY_BLOCK_TYPE_METADATA
		};

		struct dm_verity {
		struct dm_dev *data_dev;
		struct dm_dev *hash_dev;
		struct dm_target *ti;
		struct dm_bufio_client *bufio;
		char *alg_name;
		struct crypto_shash *tfm;
		u8 root_digest; / digest of the root block */
		u8 salt; / salt: its size is salt_size */
		unsigned salt_size;
		sector_t data_start; /* data offset in 512-byte sectors */
		sector_t hash_start; /* hash start in blocks */
		sector_t data_blocks; /* the number of data blocks */
		sector_t hash_blocks; /* the number of hash blocks */
		unsigned char data_dev_block_bits; /* log2(data blocksize) */
		unsigned char hash_dev_block_bits; /* log2(hash blocksize) */
		unsigned char hash_per_block_bits; /* log2(hashes in hash block) */
		unsigned char levels; /* the number of tree levels */
		unsigned char version;
		unsigned digest_size; /* digest size for the current hash algorithm */
		unsigned shash_descsize;/* the size of temporary space for crypto */
		int hash_failed; /* set to 1 if hash of any block failed */
		enum verity_mode mode; /* mode for handling verification errors */
		unsigned corrupted_errs;/* Number of errors for corrupted blocks */

		struct workqueue_struct *verify_wq;

		/* starting blocks for each tree level. 0 is the lowest level. */
		sector_t hash_level_block[DM_VERITY_MAX_LEVELS];
		};

		struct dm_verity_io {
		struct dm_verity *v;

		/* original values of bio->bi_end_io and bio->bi_private */
		bio_end_io_t *orig_bi_end_io;
		void *orig_bi_private;

		sector_t block;
		unsigned n_blocks;

		struct bvec_iter iter;

		struct work_struct work;

		/*
		* Three variably-size fields follow this struct:
		*
		* u8 hash_desc[v->shash_descsize];
		* u8 real_digest[v->digest_size];
		* u8 want_digest[v->digest_size];
		*
		* To access them use: io_hash_desc(), io_real_digest() and io_want_digest().
		*/
		};

		struct dm_verity_prefetch_work {
		struct work_struct work;
		struct dm_verity *v;
		@@ -114,21 +44,6 @@ struct dm_verity_prefetch_work {
		unsigned n_blocks;
		};

		static struct shash_desc io_hash_desc(struct dm_verity v, struct dm_verity_io *io)
		{
		return (struct shash_desc *)(io + 1);
		}

		static u8 io_real_digest(struct dm_verity v, struct dm_verity_io *io)
		{
		return (u8 *)(io + 1) + v->shash_descsize;
		}

		static u8 io_want_digest(struct dm_verity v, struct dm_verity_io *io)
		{
		return (u8 *)(io + 1) + v->shash_descsize + v->digest_size;
		}

		/*
		* Auxiliary structure appended to each dm-bufio buffer. If the value
		* hash_verified is nonzero, hash of the block has been verified.
		@@ -237,7 +152,7 @@ static int verity_hash_final(struct dm_verity v, struct shash_desc desc,
		return r;
		}

		static int verity_hash(struct dm_verity v, struct shash_desc desc,
		int verity_hash(struct dm_verity v, struct shash_desc desc,
		const u8 data, size_t len, u8 digest)
		{
		int r;
		@@ -326,12 +241,12 @@ out:
		* Verify hash of a metadata block pertaining to the specified data block
		* ("block" argument) at a specified level ("level" argument).
		*
		* On successful return, io_want_digest(v, io) contains the hash value for
		* a lower tree level or for the data block (if we're at the lowest leve).
		* On successful return, verity_io_want_digest(v, io) contains the hash value
		* for a lower tree level or for the data block (if we're at the lowest level).
		*
		* If "skip_unverified" is true, unverified buffer is skipped and 1 is returned.
		* If "skip_unverified" is false, unverified buffer is hashed and verified
		* against current value of io_want_digest(v, io).
		* against current value of verity_io_want_digest(v, io).
		*/
		static int verity_verify_level(struct dm_verity v, struct dm_verity_io io,
		sector_t block, int level, bool skip_unverified,
		@@ -358,13 +273,13 @@ static int verity_verify_level(struct dm_verity v, struct dm_verity_io io,
		goto release_ret_r;
		}

		r = verity_hash(v, io_hash_desc(v, io),
		r = verity_hash(v, verity_io_hash_desc(v, io),
		data, 1 << v->hash_dev_block_bits,
		io_real_digest(v, io));
		verity_io_real_digest(v, io));
		if (unlikely(r < 0))
		goto release_ret_r;

		if (likely(memcmp(io_real_digest(v, io), want_digest,
		if (likely(memcmp(verity_io_real_digest(v, io), want_digest,
		v->digest_size) == 0))
		aux->hash_verified = 1;
		else if (verity_handle_err(v,
		@@ -388,7 +303,7 @@ release_ret_r:
		* Find a hash for a given block, write it to digest and verify the integrity
		* of the hash tree if necessary.
		*/
		static int verity_hash_for_block(struct dm_verity v, struct dm_verity_io io,
		int verity_hash_for_block(struct dm_verity v, struct dm_verity_io io,
		sector_t block, u8 *digest)
		{
		int i;
		@@ -431,10 +346,10 @@ static int verity_verify_io(struct dm_verity_io *io)
		for (b = 0; b < io->n_blocks; b++) {
		int r;
		unsigned todo;
		struct shash_desc *desc = io_hash_desc(v, io);
		struct shash_desc *desc = verity_io_hash_desc(v, io);

		r = verity_hash_for_block(v, io, io->block + b,
		io_want_digest(v, io));
		verity_io_want_digest(v, io));
		if (unlikely(r < 0))
		return r;

		@@ -463,12 +378,12 @@ static int verity_verify_io(struct dm_verity_io *io)
		todo -= len;
		} while (todo);

		r = verity_hash_final(v, desc, io_real_digest(v, io));
		r = verity_hash_final(v, desc, verity_io_real_digest(v, io));
		if (unlikely(r < 0))
		return r;

		if (likely(memcmp(io_real_digest(v, io),
		io_want_digest(v, io), v->digest_size) == 0))
		if (likely(memcmp(verity_io_real_digest(v, io),
		verity_io_want_digest(v, io), v->digest_size) == 0))
		continue;
		else if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA,
		io->block + b))

drivers/md/dm-verity.h

0 → 100644

+113 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2012 Red Hat, Inc.
		* Copyright (C) 2015 Google, Inc.
		*
		* Author: Mikulas Patocka <mpatocka@redhat.com>
		*
		* Based on Chromium dm-verity driver (C) 2011 The Chromium OS Authors
		*
		* This file is released under the GPLv2.
		*/

		#ifndef DM_VERITY_H
		#define DM_VERITY_H

		#include "dm-bufio.h"
		#include <linux/device-mapper.h>
		#include <crypto/hash.h>

		#define DM_VERITY_MAX_LEVELS 63

		enum verity_mode {
		DM_VERITY_MODE_EIO,
		DM_VERITY_MODE_LOGGING,
		DM_VERITY_MODE_RESTART
		};

		enum verity_block_type {
		DM_VERITY_BLOCK_TYPE_DATA,
		DM_VERITY_BLOCK_TYPE_METADATA
		};

		struct dm_verity {
		struct dm_dev *data_dev;
		struct dm_dev *hash_dev;
		struct dm_target *ti;
		struct dm_bufio_client *bufio;
		char *alg_name;
		struct crypto_shash *tfm;
		u8 root_digest; / digest of the root block */
		u8 salt; / salt: its size is salt_size */
		unsigned salt_size;
		sector_t data_start; /* data offset in 512-byte sectors */
		sector_t hash_start; /* hash start in blocks */
		sector_t data_blocks; /* the number of data blocks */
		sector_t hash_blocks; /* the number of hash blocks */
		unsigned char data_dev_block_bits; /* log2(data blocksize) */
		unsigned char hash_dev_block_bits; /* log2(hash blocksize) */
		unsigned char hash_per_block_bits; /* log2(hashes in hash block) */
		unsigned char levels; /* the number of tree levels */
		unsigned char version;
		unsigned digest_size; /* digest size for the current hash algorithm */
		unsigned shash_descsize;/* the size of temporary space for crypto */
		int hash_failed; /* set to 1 if hash of any block failed */
		enum verity_mode mode; /* mode for handling verification errors */
		unsigned corrupted_errs;/* Number of errors for corrupted blocks */

		struct workqueue_struct *verify_wq;

		/* starting blocks for each tree level. 0 is the lowest level. */
		sector_t hash_level_block[DM_VERITY_MAX_LEVELS];
		};

		struct dm_verity_io {
		struct dm_verity *v;

		/* original values of bio->bi_end_io and bio->bi_private */
		bio_end_io_t *orig_bi_end_io;
		void *orig_bi_private;

		sector_t block;
		unsigned n_blocks;

		struct bvec_iter iter;

		struct work_struct work;

		/*
		* Three variably-size fields follow this struct:
		*
		* u8 hash_desc[v->shash_descsize];
		* u8 real_digest[v->digest_size];
		* u8 want_digest[v->digest_size];
		*
		* To access them use: verity_io_hash_desc(), verity_io_real_digest()
		* and verity_io_want_digest().
		*/
		};

		static inline struct shash_desc verity_io_hash_desc(struct dm_verity v,
		struct dm_verity_io *io)
		{
		return (struct shash_desc *)(io + 1);
		}

		static inline u8 verity_io_real_digest(struct dm_verity v,
		struct dm_verity_io *io)
		{
		return (u8 *)(io + 1) + v->shash_descsize;
		}

		static inline u8 verity_io_want_digest(struct dm_verity v,
		struct dm_verity_io *io)
		{
		return (u8 *)(io + 1) + v->shash_descsize + v->digest_size;
		}

		extern int verity_hash(struct dm_verity v, struct shash_desc desc,
		const u8 data, size_t len, u8 digest);

		extern int verity_hash_for_block(struct dm_verity v, struct dm_verity_io io,
		sector_t block, u8 *digest);

		#endif /* DM_VERITY_H */