cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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dm-verity.h (3758B)

      1/* SPDX-License-Identifier: GPL-2.0-only */
      2/*
      3 * Copyright (C) 2012 Red Hat, Inc.
      4 * Copyright (C) 2015 Google, Inc.
      5 *
      6 * Author: Mikulas Patocka <mpatocka@redhat.com>
      7 *
      8 * Based on Chromium dm-verity driver (C) 2011 The Chromium OS Authors
      9 */
     10
     11#ifndef DM_VERITY_H
     12#define DM_VERITY_H
     13
     14#include <linux/dm-bufio.h>
     15#include <linux/device-mapper.h>
     16#include <crypto/hash.h>
     17
     18#define DM_VERITY_MAX_LEVELS		63
     19
     20enum verity_mode {
     21	DM_VERITY_MODE_EIO,
     22	DM_VERITY_MODE_LOGGING,
     23	DM_VERITY_MODE_RESTART,
     24	DM_VERITY_MODE_PANIC
     25};
     26
     27enum verity_block_type {
     28	DM_VERITY_BLOCK_TYPE_DATA,
     29	DM_VERITY_BLOCK_TYPE_METADATA
     30};
     31
     32struct dm_verity_fec;
     33
     34struct dm_verity {
     35	struct dm_dev *data_dev;
     36	struct dm_dev *hash_dev;
     37	struct dm_target *ti;
     38	struct dm_bufio_client *bufio;
     39	char *alg_name;
     40	struct crypto_ahash *tfm;
     41	u8 *root_digest;	/* digest of the root block */
     42	u8 *salt;		/* salt: its size is salt_size */
     43	u8 *zero_digest;	/* digest for a zero block */
     44	unsigned salt_size;
     45	sector_t data_start;	/* data offset in 512-byte sectors */
     46	sector_t hash_start;	/* hash start in blocks */
     47	sector_t data_blocks;	/* the number of data blocks */
     48	sector_t hash_blocks;	/* the number of hash blocks */
     49	unsigned char data_dev_block_bits;	/* log2(data blocksize) */
     50	unsigned char hash_dev_block_bits;	/* log2(hash blocksize) */
     51	unsigned char hash_per_block_bits;	/* log2(hashes in hash block) */
     52	unsigned char levels;	/* the number of tree levels */
     53	unsigned char version;
     54	unsigned digest_size;	/* digest size for the current hash algorithm */
     55	unsigned int ahash_reqsize;/* the size of temporary space for crypto */
     56	int hash_failed;	/* set to 1 if hash of any block failed */
     57	enum verity_mode mode;	/* mode for handling verification errors */
     58	unsigned corrupted_errs;/* Number of errors for corrupted blocks */
     59
     60	struct workqueue_struct *verify_wq;
     61
     62	/* starting blocks for each tree level. 0 is the lowest level. */
     63	sector_t hash_level_block[DM_VERITY_MAX_LEVELS];
     64
     65	struct dm_verity_fec *fec;	/* forward error correction */
     66	unsigned long *validated_blocks; /* bitset blocks validated */
     67
     68	char *signature_key_desc; /* signature keyring reference */
     69};
     70
     71struct dm_verity_io {
     72	struct dm_verity *v;
     73
     74	/* original value of bio->bi_end_io */
     75	bio_end_io_t *orig_bi_end_io;
     76
     77	sector_t block;
     78	unsigned n_blocks;
     79
     80	struct bvec_iter iter;
     81
     82	struct work_struct work;
     83
     84	/*
     85	 * Three variably-size fields follow this struct:
     86	 *
     87	 * u8 hash_req[v->ahash_reqsize];
     88	 * u8 real_digest[v->digest_size];
     89	 * u8 want_digest[v->digest_size];
     90	 *
     91	 * To access them use: verity_io_hash_req(), verity_io_real_digest()
     92	 * and verity_io_want_digest().
     93	 */
     94};
     95
     96static inline struct ahash_request *verity_io_hash_req(struct dm_verity *v,
     97						     struct dm_verity_io *io)
     98{
     99	return (struct ahash_request *)(io + 1);
    100}
    101
    102static inline u8 *verity_io_real_digest(struct dm_verity *v,
    103					struct dm_verity_io *io)
    104{
    105	return (u8 *)(io + 1) + v->ahash_reqsize;
    106}
    107
    108static inline u8 *verity_io_want_digest(struct dm_verity *v,
    109					struct dm_verity_io *io)
    110{
    111	return (u8 *)(io + 1) + v->ahash_reqsize + v->digest_size;
    112}
    113
    114static inline u8 *verity_io_digest_end(struct dm_verity *v,
    115				       struct dm_verity_io *io)
    116{
    117	return verity_io_want_digest(v, io) + v->digest_size;
    118}
    119
    120extern int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io,
    121			       struct bvec_iter *iter,
    122			       int (*process)(struct dm_verity *v,
    123					      struct dm_verity_io *io,
    124					      u8 *data, size_t len));
    125
    126extern int verity_hash(struct dm_verity *v, struct ahash_request *req,
    127		       const u8 *data, size_t len, u8 *digest);
    128
    129extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io,
    130				 sector_t block, u8 *digest, bool *is_zero);
    131
    132#endif /* DM_VERITY_H */