diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c index 0f0eb8a3d922..dab98fee0754 100644 --- a/drivers/md/dm-verity-fec.c +++ b/drivers/md/dm-verity-fec.c @@ -188,7 +188,7 @@ error: static int fec_is_erasure(struct dm_verity *v, struct dm_verity_io *io, u8 *want_digest, u8 *data) { - if (unlikely(verity_hash(v, verity_io_hash_desc(v, io), + if (unlikely(verity_hash(v, verity_io_hash_req(v, io), data, 1 << v->data_dev_block_bits, verity_io_real_digest(v, io)))) return 0; @@ -397,7 +397,7 @@ static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io, } /* Always re-validate the corrected block against the expected hash */ - r = verity_hash(v, verity_io_hash_desc(v, io), fio->output, + r = verity_hash(v, verity_io_hash_req(v, io), fio->output, 1 << v->data_dev_block_bits, verity_io_real_digest(v, io)); if (unlikely(r < 0)) diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 7335d8a3fc47..97de961a3bfc 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -93,81 +93,123 @@ static sector_t verity_position_at_level(struct dm_verity *v, sector_t block, } /* - * Wrapper for crypto_shash_init, which handles verity salting. + * Callback function for asynchrnous crypto API completion notification */ -static int verity_hash_init(struct dm_verity *v, struct shash_desc *desc) +static void verity_op_done(struct crypto_async_request *base, int err) +{ + struct verity_result *res = (struct verity_result *)base->data; + + if (err == -EINPROGRESS) + return; + + res->err = err; + complete(&res->completion); +} + +/* + * Wait for async crypto API callback + */ +static inline int verity_complete_op(struct verity_result *res, int ret) +{ + switch (ret) { + case 0: + break; + + case -EINPROGRESS: + case -EBUSY: + ret = wait_for_completion_interruptible(&res->completion); + if (!ret) + ret = res->err; + reinit_completion(&res->completion); + break; + + default: + DMERR("verity_wait_hash: crypto op submission failed: %d", ret); + } + + if (unlikely(ret < 0)) + DMERR("verity_wait_hash: crypto op failed: %d", ret); + + return ret; +} + +static int verity_hash_update(struct dm_verity *v, struct ahash_request *req, + const u8 *data, size_t len, + struct verity_result *res) +{ + struct scatterlist sg; + + sg_init_one(&sg, data, len); + ahash_request_set_crypt(req, &sg, NULL, len); + + return verity_complete_op(res, crypto_ahash_update(req)); +} + +/* + * Wrapper for crypto_ahash_init, which handles verity salting. + */ +static int verity_hash_init(struct dm_verity *v, struct ahash_request *req, + struct verity_result *res) { int r; - desc->tfm = v->tfm; - desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + ahash_request_set_tfm(req, v->tfm); + ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | + CRYPTO_TFM_REQ_MAY_BACKLOG, + verity_op_done, (void *)res); + init_completion(&res->completion); - r = crypto_shash_init(desc); + r = verity_complete_op(res, crypto_ahash_init(req)); if (unlikely(r < 0)) { - DMERR("crypto_shash_init failed: %d", r); + DMERR("crypto_ahash_init failed: %d", r); return r; } - if (likely(v->version >= 1)) { - r = crypto_shash_update(desc, v->salt, v->salt_size); - - if (unlikely(r < 0)) { - DMERR("crypto_shash_update failed: %d", r); - return r; - } - } - - return 0; -} - -static int verity_hash_update(struct dm_verity *v, struct shash_desc *desc, - const u8 *data, size_t len) -{ - int r = crypto_shash_update(desc, data, len); - - if (unlikely(r < 0)) - DMERR("crypto_shash_update failed: %d", r); + if (likely(v->version >= 1)) + r = verity_hash_update(v, req, v->salt, v->salt_size, res); return r; } -static int verity_hash_final(struct dm_verity *v, struct shash_desc *desc, - u8 *digest) +static int verity_hash_final(struct dm_verity *v, struct ahash_request *req, + u8 *digest, struct verity_result *res) { int r; if (unlikely(!v->version)) { - r = crypto_shash_update(desc, v->salt, v->salt_size); + r = verity_hash_update(v, req, v->salt, v->salt_size, res); if (r < 0) { - DMERR("crypto_shash_update failed: %d", r); - return r; + DMERR("verity_hash_final failed updating salt: %d", r); + goto out; } } - r = crypto_shash_final(desc, digest); - - if (unlikely(r < 0)) - DMERR("crypto_shash_final failed: %d", r); - + ahash_request_set_crypt(req, NULL, digest, 0); + r = verity_complete_op(res, crypto_ahash_final(req)); +out: return r; } -int verity_hash(struct dm_verity *v, struct shash_desc *desc, +int verity_hash(struct dm_verity *v, struct ahash_request *req, const u8 *data, size_t len, u8 *digest) { int r; + struct verity_result res; - r = verity_hash_init(v, desc); + r = verity_hash_init(v, req, &res); if (unlikely(r < 0)) - return r; + goto out; - r = verity_hash_update(v, desc, data, len); + r = verity_hash_update(v, req, data, len, &res); if (unlikely(r < 0)) - return r; + goto out; - return verity_hash_final(v, desc, digest); + r = verity_hash_final(v, req, digest, &res); + +out: + return r; } static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level, @@ -275,7 +317,7 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io, goto release_ret_r; } - r = verity_hash(v, verity_io_hash_desc(v, io), + r = verity_hash(v, verity_io_hash_req(v, io), data, 1 << v->hash_dev_block_bits, verity_io_real_digest(v, io)); if (unlikely(r < 0)) @@ -343,6 +385,49 @@ out: return r; } +/* + * Calculates the digest for the given bio + */ +int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io, + struct bvec_iter *iter, struct verity_result *res) +{ + unsigned int todo = 1 << v->data_dev_block_bits; + struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size); + struct scatterlist sg; + struct ahash_request *req = verity_io_hash_req(v, io); + + do { + int r; + unsigned int len; + struct bio_vec bv = bio_iter_iovec(bio, *iter); + + sg_init_table(&sg, 1); + + len = bv.bv_len; + + if (likely(len >= todo)) + len = todo; + /* + * Operating on a single page at a time looks suboptimal + * until you consider the typical block size is 4,096B. + * Going through this loops twice should be very rare. + */ + sg_set_page(&sg, bv.bv_page, len, bv.bv_offset); + ahash_request_set_crypt(req, &sg, NULL, len); + r = verity_complete_op(res, crypto_ahash_update(req)); + + if (unlikely(r < 0)) { + DMERR("verity_for_io_block crypto op failed: %d", r); + return r; + } + + bio_advance_iter(bio, iter, len); + todo -= len; + } while (todo); + + return 0; +} + /* * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec * starting from iter. @@ -381,12 +466,6 @@ int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, return 0; } -static int verity_bv_hash_update(struct dm_verity *v, struct dm_verity_io *io, - u8 *data, size_t len) -{ - return verity_hash_update(v, verity_io_hash_desc(v, io), data, len); -} - static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io, u8 *data, size_t len) { @@ -403,10 +482,11 @@ static int verity_verify_io(struct dm_verity_io *io) struct dm_verity *v = io->v; struct bvec_iter start; unsigned b; + struct verity_result res; for (b = 0; b < io->n_blocks; b++) { int r; - struct shash_desc *desc = verity_io_hash_desc(v, io); + struct ahash_request *req = verity_io_hash_req(v, io); r = verity_hash_for_block(v, io, io->block + b, verity_io_want_digest(v, io), @@ -427,16 +507,17 @@ static int verity_verify_io(struct dm_verity_io *io) continue; } - r = verity_hash_init(v, desc); + r = verity_hash_init(v, req, &res); if (unlikely(r < 0)) return r; start = io->iter; - r = verity_for_bv_block(v, io, &io->iter, verity_bv_hash_update); + r = verity_for_io_block(v, io, &io->iter, &res); if (unlikely(r < 0)) return r; - r = verity_hash_final(v, desc, verity_io_real_digest(v, io)); + r = verity_hash_final(v, req, verity_io_real_digest(v, io), + &res); if (unlikely(r < 0)) return r; @@ -705,7 +786,7 @@ static void verity_dtr(struct dm_target *ti) kfree(v->zero_digest); if (v->tfm) - crypto_free_shash(v->tfm); + crypto_free_ahash(v->tfm); kfree(v->alg_name); @@ -723,7 +804,7 @@ static void verity_dtr(struct dm_target *ti) static int verity_alloc_zero_digest(struct dm_verity *v) { int r = -ENOMEM; - struct shash_desc *desc; + struct ahash_request *req; u8 *zero_data; v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL); @@ -731,9 +812,9 @@ static int verity_alloc_zero_digest(struct dm_verity *v) if (!v->zero_digest) return r; - desc = kmalloc(v->shash_descsize, GFP_KERNEL); + req = kmalloc(v->ahash_reqsize, GFP_KERNEL); - if (!desc) + if (!req) return r; /* verity_dtr will free zero_digest */ zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL); @@ -741,11 +822,11 @@ static int verity_alloc_zero_digest(struct dm_verity *v) if (!zero_data) goto out; - r = verity_hash(v, desc, zero_data, 1 << v->data_dev_block_bits, + r = verity_hash(v, req, zero_data, 1 << v->data_dev_block_bits, v->zero_digest); out: - kfree(desc); + kfree(req); kfree(zero_data); return r; @@ -923,21 +1004,21 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) goto bad; } - v->tfm = crypto_alloc_shash(v->alg_name, 0, 0); + v->tfm = crypto_alloc_ahash(v->alg_name, 0, 0); if (IS_ERR(v->tfm)) { ti->error = "Cannot initialize hash function"; r = PTR_ERR(v->tfm); v->tfm = NULL; goto bad; } - v->digest_size = crypto_shash_digestsize(v->tfm); + 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; goto bad; } - v->shash_descsize = - sizeof(struct shash_desc) + crypto_shash_descsize(v->tfm); + 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) { @@ -1037,7 +1118,7 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) } ti->per_io_data_size = sizeof(struct dm_verity_io) + - v->shash_descsize + v->digest_size * 2; + v->ahash_reqsize + v->digest_size * 2; r = verity_fec_ctr(v); if (r) diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h index fb419f422d73..a59e0ada6fd3 100644 --- a/drivers/md/dm-verity.h +++ b/drivers/md/dm-verity.h @@ -37,7 +37,7 @@ struct dm_verity { struct dm_target *ti; struct dm_bufio_client *bufio; char *alg_name; - struct crypto_shash *tfm; + struct crypto_ahash *tfm; u8 *root_digest; /* digest of the root block */ u8 *salt; /* salt: its size is salt_size */ u8 *zero_digest; /* digest for a zero block */ @@ -52,7 +52,7 @@ struct dm_verity { 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 */ + unsigned int ahash_reqsize;/* 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 */ @@ -81,31 +81,36 @@ struct dm_verity_io { /* * Three variably-size fields follow this struct: * - * u8 hash_desc[v->shash_descsize]; + * u8 hash_req[v->ahash_reqsize]; * u8 real_digest[v->digest_size]; * u8 want_digest[v->digest_size]; * - * To access them use: verity_io_hash_desc(), verity_io_real_digest() + * To access them use: verity_io_hash_req(), verity_io_real_digest() * and verity_io_want_digest(). */ }; -static inline struct shash_desc *verity_io_hash_desc(struct dm_verity *v, +struct verity_result { + struct completion completion; + int err; +}; + +static inline struct ahash_request *verity_io_hash_req(struct dm_verity *v, struct dm_verity_io *io) { - return (struct shash_desc *)(io + 1); + return (struct ahash_request *)(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; + return (u8 *)(io + 1) + v->ahash_reqsize; } 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; + return (u8 *)(io + 1) + v->ahash_reqsize + v->digest_size; } static inline u8 *verity_io_digest_end(struct dm_verity *v, @@ -120,7 +125,7 @@ extern int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, struct dm_verity_io *io, u8 *data, size_t len)); -extern int verity_hash(struct dm_verity *v, struct shash_desc *desc, +extern int verity_hash(struct dm_verity *v, struct ahash_request *req, const u8 *data, size_t len, u8 *digest); extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io,