Commit 44d36a2e authored by Eric Biggers's avatar Eric Biggers Committed by Mikulas Patocka
Browse files

dm-verity: move hash algorithm setup into its own function 



Move the code that sets up the hash transformation into its own
function.  No change in behavior.

Reviewed-by: default avatarSami Tolvanen <samitolvanen@google.com>
Acked-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
parent 140ce37f

drivers/md/dm-verity-target.c

+39 −31
Original line number Diff line number Diff line
@@ -1226,6 +1226,43 @@ static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v, 
	return r;

}



static int verity_setup_hash_alg(struct dm_verity *v, const char *alg_name)

{

	struct dm_target *ti = v->ti;

	struct crypto_ahash *ahash;



	v->alg_name = kstrdup(alg_name, GFP_KERNEL);

	if (!v->alg_name) {

		ti->error = "Cannot allocate algorithm name";

		return -ENOMEM;

	}



	ahash = crypto_alloc_ahash(alg_name, 0,

				   v->use_bh_wq ? CRYPTO_ALG_ASYNC : 0);

	if (IS_ERR(ahash)) {

		ti->error = "Cannot initialize hash function";

		return PTR_ERR(ahash);

	}

	v->tfm = ahash;



	/*

	 * dm-verity performance can vary greatly depending on which hash

	 * algorithm implementation is used.  Help people debug performance

	 * problems by logging the ->cra_driver_name.

	 */

	DMINFO("%s using implementation \"%s\"", alg_name,

	       crypto_hash_alg_common(ahash)->base.cra_driver_name);



	v->digest_size = crypto_ahash_digestsize(ahash);

	if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) {

		ti->error = "Digest size too big";

		return -EINVAL;

	}

	v->ahash_reqsize = sizeof(struct ahash_request) +

			   crypto_ahash_reqsize(ahash);

	return 0;

}



/*

 * Target parameters:

 *	<version>	The current format is version 1.
@@ -1350,38 +1387,9 @@ static int verity_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
	}

	v->hash_start = num_ll;



	v->alg_name = kstrdup(argv[7], GFP_KERNEL);

	if (!v->alg_name) {

		ti->error = "Cannot allocate algorithm name";

		r = -ENOMEM;

		goto bad;

	}



	v->tfm = crypto_alloc_ahash(v->alg_name, 0,

				    v->use_bh_wq ? CRYPTO_ALG_ASYNC : 0);

	if (IS_ERR(v->tfm)) {

		ti->error = "Cannot initialize hash function";

		r = PTR_ERR(v->tfm);

		v->tfm = NULL;

		goto bad;

	}



	/*

	 * dm-verity performance can vary greatly depending on which hash

	 * algorithm implementation is used.  Help people debug performance

	 * problems by logging the ->cra_driver_name.

	 */

	DMINFO("%s using implementation \"%s\"", v->alg_name,

	       crypto_hash_alg_common(v->tfm)->base.cra_driver_name);



	v->digest_size = crypto_ahash_digestsize(v->tfm);

	if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) {

		ti->error = "Digest size too big";

		r = -EINVAL;

	r = verity_setup_hash_alg(v, argv[7]);

	if (r)

		goto bad;

	}

	v->ahash_reqsize = sizeof(struct ahash_request) +

		crypto_ahash_reqsize(v->tfm);



	v->root_digest = kmalloc(v->digest_size, GFP_KERNEL);

	if (!v->root_digest) {