1 files changed, 500 insertions, 267 deletions

diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index bb5da66da4c1..3c427f18a04b 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -22,6 +22,7 @@
 #include <linux/scatterlist.h>
 #include <linux/string.h>
 #include <linux/jump_label.h>
+#include <linux/security.h>
 
 #define DM_MSG_PREFIX			"verity"
 
@@ -29,25 +30,40 @@
 #define DM_VERITY_ENV_VAR_NAME		"DM_VERITY_ERR_BLOCK_NR"
 
 #define DM_VERITY_DEFAULT_PREFETCH_SIZE	262144
+#define DM_VERITY_USE_BH_DEFAULT_BYTES	8192
 
 #define DM_VERITY_MAX_CORRUPTED_ERRS	100
 
 #define DM_VERITY_OPT_LOGGING		"ignore_corruption"
 #define DM_VERITY_OPT_RESTART		"restart_on_corruption"
 #define DM_VERITY_OPT_PANIC		"panic_on_corruption"
+#define DM_VERITY_OPT_ERROR_RESTART	"restart_on_error"
+#define DM_VERITY_OPT_ERROR_PANIC	"panic_on_error"
 #define DM_VERITY_OPT_IGN_ZEROES	"ignore_zero_blocks"
 #define DM_VERITY_OPT_AT_MOST_ONCE	"check_at_most_once"
 #define DM_VERITY_OPT_TASKLET_VERIFY	"try_verify_in_tasklet"
 
-#define DM_VERITY_OPTS_MAX		(4 + DM_VERITY_OPTS_FEC + \
+#define DM_VERITY_OPTS_MAX		(5 + DM_VERITY_OPTS_FEC + \
 					 DM_VERITY_ROOT_HASH_VERIFICATION_OPTS)
 
 static unsigned int dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE;
 
 module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, 0644);
 
+static unsigned int dm_verity_use_bh_bytes[4] = {
+	DM_VERITY_USE_BH_DEFAULT_BYTES,	// IOPRIO_CLASS_NONE
+	DM_VERITY_USE_BH_DEFAULT_BYTES,	// IOPRIO_CLASS_RT
+	DM_VERITY_USE_BH_DEFAULT_BYTES,	// IOPRIO_CLASS_BE
+	0				// IOPRIO_CLASS_IDLE
+};
+
+module_param_array_named(use_bh_bytes, dm_verity_use_bh_bytes, uint, NULL, 0644);
+
 static DEFINE_STATIC_KEY_FALSE(use_bh_wq_enabled);
 
+/* Is at least one dm-verity instance using ahash_tfm instead of shash_tfm? */
+static DEFINE_STATIC_KEY_FALSE(ahash_enabled);
+
 struct dm_verity_prefetch_work {
 	struct work_struct work;
 	struct dm_verity *v;
@@ -87,7 +103,7 @@ static void dm_bufio_alloc_callback(struct dm_buffer *buf)
  */
 static sector_t verity_map_sector(struct dm_verity *v, sector_t bi_sector)
 {
-	return v->data_start + dm_target_offset(v->ti, bi_sector);
+	return dm_target_offset(v->ti, bi_sector);
 }
 
 /*
@@ -102,7 +118,7 @@ static sector_t verity_position_at_level(struct dm_verity *v, sector_t block,
 	return block >> (level * v->hash_per_block_bits);
 }
 
-static int verity_hash_update(struct dm_verity *v, struct ahash_request *req,
+static int verity_ahash_update(struct dm_verity *v, struct ahash_request *req,
 				const u8 *data, size_t len,
 				struct crypto_wait *wait)
 {
@@ -135,12 +151,12 @@ static int verity_hash_update(struct dm_verity *v, struct ahash_request *req,
 /*
  * Wrapper for crypto_ahash_init, which handles verity salting.
  */
-static int verity_hash_init(struct dm_verity *v, struct ahash_request *req,
+static int verity_ahash_init(struct dm_verity *v, struct ahash_request *req,
 				struct crypto_wait *wait, bool may_sleep)
 {
 	int r;
 
-	ahash_request_set_tfm(req, v->tfm);
+	ahash_request_set_tfm(req, v->ahash_tfm);
 	ahash_request_set_callback(req,
 		may_sleep ? CRYPTO_TFM_REQ_MAY_SLEEP | CRYPTO_TFM_REQ_MAY_BACKLOG : 0,
 		crypto_req_done, (void *)wait);
@@ -155,18 +171,18 @@ static int verity_hash_init(struct dm_verity *v, struct ahash_request *req,
 	}
 
 	if (likely(v->salt_size && (v->version >= 1)))
-		r = verity_hash_update(v, req, v->salt, v->salt_size, wait);
+		r = verity_ahash_update(v, req, v->salt, v->salt_size, wait);
 
 	return r;
 }
 
-static int verity_hash_final(struct dm_verity *v, struct ahash_request *req,
-			     u8 *digest, struct crypto_wait *wait)
+static int verity_ahash_final(struct dm_verity *v, struct ahash_request *req,
+			      u8 *digest, struct crypto_wait *wait)
 {
 	int r;
 
 	if (unlikely(v->salt_size && (!v->version))) {
-		r = verity_hash_update(v, req, v->salt, v->salt_size, wait);
+		r = verity_ahash_update(v, req, v->salt, v->salt_size, wait);
 
 		if (r < 0) {
 			DMERR("%s failed updating salt: %d", __func__, r);
@@ -180,23 +196,27 @@ out:
 	return r;
 }
 
-int verity_hash(struct dm_verity *v, struct ahash_request *req,
+int verity_hash(struct dm_verity *v, struct dm_verity_io *io,
 		const u8 *data, size_t len, u8 *digest, bool may_sleep)
 {
 	int r;
-	struct crypto_wait wait;
-
-	r = verity_hash_init(v, req, &wait, may_sleep);
-	if (unlikely(r < 0))
-		goto out;
 
-	r = verity_hash_update(v, req, data, len, &wait);
-	if (unlikely(r < 0))
-		goto out;
+	if (static_branch_unlikely(&ahash_enabled) && !v->shash_tfm) {
+		struct ahash_request *req = verity_io_hash_req(v, io);
+		struct crypto_wait wait;
 
-	r = verity_hash_final(v, req, digest, &wait);
+		r = verity_ahash_init(v, req, &wait, may_sleep) ?:
+		    verity_ahash_update(v, req, data, len, &wait) ?:
+		    verity_ahash_final(v, req, digest, &wait);
+	} else {
+		struct shash_desc *desc = verity_io_hash_req(v, io);
 
-out:
+		desc->tfm = v->shash_tfm;
+		r = crypto_shash_import(desc, v->initial_hashstate) ?:
+		    crypto_shash_finup(desc, data, len, digest);
+	}
+	if (unlikely(r))
+		DMERR("Error hashing block: %d", r);
 	return r;
 }
 
@@ -301,7 +321,7 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io,
 
 	if (static_branch_unlikely(&use_bh_wq_enabled) && io->in_bh) {
 		data = dm_bufio_get(v->bufio, hash_block, &buf);
-		if (data == NULL) {
+		if (IS_ERR_OR_NULL(data)) {
 			/*
 			 * In tasklet and the hash was not in the bufio cache.
 			 * Return early and resume execution from a work-queue
@@ -311,11 +331,27 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io,
 		}
 	} else {
 		data = dm_bufio_read_with_ioprio(v->bufio, hash_block,
-						&buf, bio_prio(bio));
+						&buf, bio->bi_ioprio);
 	}
 
-	if (IS_ERR(data))
-		return PTR_ERR(data);
+	if (IS_ERR(data)) {
+		if (skip_unverified)
+			return 1;
+		r = PTR_ERR(data);
+		data = dm_bufio_new(v->bufio, hash_block, &buf);
+		if (IS_ERR(data))
+			return r;
+		if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_METADATA,
+				      hash_block, data) == 0) {
+			aux = dm_bufio_get_aux_data(buf);
+			aux->hash_verified = 1;
+			goto release_ok;
+		} else {
+			dm_bufio_release(buf);
+			dm_bufio_forget(v->bufio, hash_block);
+			return r;
+		}
+	}
 
 	aux = dm_bufio_get_aux_data(buf);
 
@@ -325,8 +361,7 @@ 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_req(v, io),
-				data, 1 << v->hash_dev_block_bits,
+		r = verity_hash(v, io, data, 1 << v->hash_dev_block_bits,
 				verity_io_real_digest(v, io), !io->in_bh);
 		if (unlikely(r < 0))
 			goto release_ret_r;
@@ -342,14 +377,14 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io,
 			r = -EAGAIN;
 			goto release_ret_r;
 		} else if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_METADATA,
-					     hash_block, data, NULL) == 0)
+					     hash_block, data) == 0)
 			aux->hash_verified = 1;
 		else if (verity_handle_err(v,
 					   DM_VERITY_BLOCK_TYPE_METADATA,
 					   hash_block)) {
-			struct bio *bio =
-				dm_bio_from_per_bio_data(io,
-							 v->ti->per_io_data_size);
+			struct bio *bio;
+			io->had_mismatch = true;
+			bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
 			dm_audit_log_bio(DM_MSG_PREFIX, "verify-metadata", bio,
 					 block, 0);
 			r = -EIO;
@@ -357,6 +392,7 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io,
 		}
 	}
 
+release_ok:
 	data += offset;
 	memcpy(want_digest, data, v->digest_size);
 	r = 0;
@@ -404,98 +440,8 @@ out:
 	return r;
 }
 
-/*
- * Calculates the digest for the given bio
- */
-static int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io,
-			       struct bvec_iter *iter, struct crypto_wait *wait)
-{
-	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 = crypto_wait_req(crypto_ahash_update(req), wait);
-
-		if (unlikely(r < 0)) {
-			DMERR("%s crypto op failed: %d", __func__, 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.
- */
-int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io,
-			struct bvec_iter *iter,
-			int (*process)(struct dm_verity *v,
-				       struct dm_verity_io *io, u8 *data,
-				       size_t len))
-{
-	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);
-
-	do {
-		int r;
-		u8 *page;
-		unsigned int len;
-		struct bio_vec bv = bio_iter_iovec(bio, *iter);
-
-		page = bvec_kmap_local(&bv);
-		len = bv.bv_len;
-
-		if (likely(len >= todo))
-			len = todo;
-
-		r = process(v, io, page, len);
-		kunmap_local(page);
-
-		if (r < 0)
-			return r;
-
-		bio_advance_iter(bio, iter, len);
-		todo -= len;
-	} while (todo);
-
-	return 0;
-}
-
-static int verity_recheck_copy(struct dm_verity *v, struct dm_verity_io *io,
-			       u8 *data, size_t len)
-{
-	memcpy(data, io->recheck_buffer, len);
-	io->recheck_buffer += len;
-
-	return 0;
-}
-
 static noinline int verity_recheck(struct dm_verity *v, struct dm_verity_io *io,
-				   struct bvec_iter start, sector_t cur_block)
+				   sector_t cur_block, u8 *dest)
 {
 	struct page *page;
 	void *buffer;
@@ -518,8 +464,7 @@ static noinline int verity_recheck(struct dm_verity *v, struct dm_verity_io *io,
 	if (unlikely(r))
 		goto free_ret;
 
-	r = verity_hash(v, verity_io_hash_req(v, io), buffer,
-			1 << v->data_dev_block_bits,
+	r = verity_hash(v, io, buffer, 1 << v->data_dev_block_bits,
 			verity_io_real_digest(v, io), true);
 	if (unlikely(r))
 		goto free_ret;
@@ -530,11 +475,7 @@ static noinline int verity_recheck(struct dm_verity *v, struct dm_verity_io *io,
 		goto free_ret;
 	}
 
-	io->recheck_buffer = buffer;
-	r = verity_for_bv_block(v, io, &start, verity_recheck_copy);
-	if (unlikely(r))
-		goto free_ret;
-
+	memcpy(dest, buffer, 1 << v->data_dev_block_bits);
 	r = 0;
 free_ret:
 	mempool_free(page, &v->recheck_pool);
@@ -542,23 +483,37 @@ free_ret:
 	return r;
 }
 
-static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io,
-			  u8 *data, size_t len)
+static int verity_handle_data_hash_mismatch(struct dm_verity *v,
+					    struct dm_verity_io *io,
+					    struct bio *bio, sector_t blkno,
+					    u8 *data)
 {
-	memset(data, 0, len);
-	return 0;
-}
-
-/*
- * Moves the bio iter one data block forward.
- */
-static inline void verity_bv_skip_block(struct dm_verity *v,
-					struct dm_verity_io *io,
-					struct bvec_iter *iter)
-{
-	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
+	if (static_branch_unlikely(&use_bh_wq_enabled) && io->in_bh) {
+		/*
+		 * Error handling code (FEC included) cannot be run in the
+		 * BH workqueue, so fallback to a standard workqueue.
+		 */
+		return -EAGAIN;
+	}
+	if (verity_recheck(v, io, blkno, data) == 0) {
+		if (v->validated_blocks)
+			set_bit(blkno, v->validated_blocks);
+		return 0;
+	}
+#if defined(CONFIG_DM_VERITY_FEC)
+	if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_DATA, blkno,
+			      data) == 0)
+		return 0;
+#endif
+	if (bio->bi_status)
+		return -EIO; /* Error correction failed; Just return error */
 
-	bio_advance_iter(bio, iter, 1 << v->data_dev_block_bits);
+	if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA, blkno)) {
+		io->had_mismatch = true;
+		dm_audit_log_bio(DM_MSG_PREFIX, "verify-data", bio, blkno, 0);
+		return -EIO;
+	}
+	return 0;
 }
 
 /*
@@ -566,12 +521,10 @@ static inline void verity_bv_skip_block(struct dm_verity *v,
  */
 static int verity_verify_io(struct dm_verity_io *io)
 {
-	bool is_zero;
 	struct dm_verity *v = io->v;
-	struct bvec_iter start;
+	const unsigned int block_size = 1 << v->data_dev_block_bits;
 	struct bvec_iter iter_copy;
 	struct bvec_iter *iter;
-	struct crypto_wait wait;
 	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
 	unsigned int b;
 
@@ -585,16 +538,17 @@ static int verity_verify_io(struct dm_verity_io *io)
 	} else
 		iter = &io->iter;
 
-	for (b = 0; b < io->n_blocks; b++) {
+	for (b = 0; b < io->n_blocks;
+	     b++, bio_advance_iter(bio, iter, block_size)) {
 		int r;
 		sector_t cur_block = io->block + b;
-		struct ahash_request *req = verity_io_hash_req(v, io);
+		bool is_zero;
+		struct bio_vec bv;
+		void *data;
 
 		if (v->validated_blocks && bio->bi_status == BLK_STS_OK &&
-		    likely(test_bit(cur_block, v->validated_blocks))) {
-			verity_bv_skip_block(v, io, iter);
+		    likely(test_bit(cur_block, v->validated_blocks)))
 			continue;
-		}
 
 		r = verity_hash_for_block(v, io, cur_block,
 					  verity_io_want_digest(v, io),
@@ -602,67 +556,49 @@ static int verity_verify_io(struct dm_verity_io *io)
 		if (unlikely(r < 0))
 			return r;
 
+		bv = bio_iter_iovec(bio, *iter);
+		if (unlikely(bv.bv_len < block_size)) {
+			/*
+			 * Data block spans pages.  This should not happen,
+			 * since dm-verity sets dma_alignment to the data block
+			 * size minus 1, and dm-verity also doesn't allow the
+			 * data block size to be greater than PAGE_SIZE.
+			 */
+			DMERR_LIMIT("unaligned io (data block spans pages)");
+			return -EIO;
+		}
+
+		data = bvec_kmap_local(&bv);
+
 		if (is_zero) {
 			/*
 			 * If we expect a zero block, don't validate, just
 			 * return zeros.
 			 */
-			r = verity_for_bv_block(v, io, iter,
-						verity_bv_zero);
-			if (unlikely(r < 0))
-				return r;
-
+			memset(data, 0, block_size);
+			kunmap_local(data);
 			continue;
 		}
 
-		r = verity_hash_init(v, req, &wait, !io->in_bh);
-		if (unlikely(r < 0))
-			return r;
-
-		start = *iter;
-		r = verity_for_io_block(v, io, iter, &wait);
-		if (unlikely(r < 0))
-			return r;
-
-		r = verity_hash_final(v, req, verity_io_real_digest(v, io),
-					&wait);
-		if (unlikely(r < 0))
+		r = verity_hash(v, io, data, block_size,
+				verity_io_real_digest(v, io), !io->in_bh);
+		if (unlikely(r < 0)) {
+			kunmap_local(data);
 			return r;
+		}
 
 		if (likely(memcmp(verity_io_real_digest(v, io),
 				  verity_io_want_digest(v, io), v->digest_size) == 0)) {
 			if (v->validated_blocks)
 				set_bit(cur_block, v->validated_blocks);
+			kunmap_local(data);
 			continue;
-		} else if (static_branch_unlikely(&use_bh_wq_enabled) && io->in_bh) {
-			/*
-			 * Error handling code (FEC included) cannot be run in a
-			 * tasklet since it may sleep, so fallback to work-queue.
-			 */
-			return -EAGAIN;
-		} else if (verity_recheck(v, io, start, cur_block) == 0) {
-			if (v->validated_blocks)
-				set_bit(cur_block, v->validated_blocks);
-			continue;
-#if defined(CONFIG_DM_VERITY_FEC)
-		} else if (verity_fec_decode(v, io, DM_VERITY_BLOCK_TYPE_DATA,
-					     cur_block, NULL, &start) == 0) {
-			continue;
-#endif
-		} else {
-			if (bio->bi_status) {
-				/*
-				 * Error correction failed; Just return error
-				 */
-				return -EIO;
-			}
-			if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA,
-					      cur_block)) {
-				dm_audit_log_bio(DM_MSG_PREFIX, "verify-data",
-						 bio, cur_block, 0);
-				return -EIO;
-			}
 		}
+		r = verity_handle_data_hash_mismatch(v, io, bio, cur_block,
+						     data);
+		kunmap_local(data);
+		if (unlikely(r))
+			return r;
 	}
 
 	return 0;
@@ -677,6 +613,11 @@ static inline bool verity_is_system_shutting_down(void)
 		|| system_state == SYSTEM_RESTART;
 }
 
+static void restart_io_error(struct work_struct *w)
+{
+	kernel_restart("dm-verity device has I/O error");
+}
+
 /*
  * End one "io" structure with a given error.
  */
@@ -691,6 +632,24 @@ static void verity_finish_io(struct dm_verity_io *io, blk_status_t status)
 	if (!static_branch_unlikely(&use_bh_wq_enabled) || !io->in_bh)
 		verity_fec_finish_io(io);
 
+	if (unlikely(status != BLK_STS_OK) &&
+	    unlikely(!(bio->bi_opf & REQ_RAHEAD)) &&
+	    !io->had_mismatch &&
+	    !verity_is_system_shutting_down()) {
+		if (v->error_mode == DM_VERITY_MODE_PANIC) {
+			panic("dm-verity device has I/O error");
+		}
+		if (v->error_mode == DM_VERITY_MODE_RESTART) {
+			static DECLARE_WORK(restart_work, restart_io_error);
+			queue_work(v->verify_wq, &restart_work);
+			/*
+			 * We deliberately don't call bio_endio here, because
+			 * the machine will be restarted anyway.
+			 */
+			return;
+		}
+	}
+
 	bio_endio(bio);
 }
 
@@ -720,9 +679,17 @@ static void verity_bh_work(struct work_struct *w)
 	verity_finish_io(io, errno_to_blk_status(err));
 }
 
+static inline bool verity_use_bh(unsigned int bytes, unsigned short ioprio)
+{
+	return ioprio <= IOPRIO_CLASS_IDLE &&
+		bytes <= READ_ONCE(dm_verity_use_bh_bytes[ioprio]);
+}
+
 static void verity_end_io(struct bio *bio)
 {
 	struct dm_verity_io *io = bio->bi_private;
+	unsigned short ioprio = IOPRIO_PRIO_CLASS(bio->bi_ioprio);
+	unsigned int bytes = io->n_blocks << io->v->data_dev_block_bits;
 
 	if (bio->bi_status &&
 	    (!verity_fec_is_enabled(io->v) ||
@@ -732,9 +699,14 @@ static void verity_end_io(struct bio *bio)
 		return;
 	}
 
-	if (static_branch_unlikely(&use_bh_wq_enabled) && io->v->use_bh_wq) {
-		INIT_WORK(&io->bh_work, verity_bh_work);
-		queue_work(system_bh_wq, &io->bh_work);
+	if (static_branch_unlikely(&use_bh_wq_enabled) && io->v->use_bh_wq &&
+		verity_use_bh(bytes, ioprio)) {
+		if (in_hardirq() || irqs_disabled()) {
+			INIT_WORK(&io->bh_work, verity_bh_work);
+			queue_work(system_bh_wq, &io->bh_work);
+		} else {
+			verity_bh_work(&io->bh_work);
+		}
 	} else {
 		INIT_WORK(&io->work, verity_work);
 		queue_work(io->v->verify_wq, &io->work);
@@ -849,6 +821,7 @@ static int verity_map(struct dm_target *ti, struct bio *bio)
 	io->orig_bi_end_io = bio->bi_end_io;
 	io->block = bio->bi_iter.bi_sector >> (v->data_dev_block_bits - SECTOR_SHIFT);
 	io->n_blocks = bio->bi_iter.bi_size >> v->data_dev_block_bits;
+	io->had_mismatch = false;
 
 	bio->bi_end_io = verity_end_io;
 	bio->bi_private = io;
@@ -856,13 +829,20 @@ static int verity_map(struct dm_target *ti, struct bio *bio)
 
 	verity_fec_init_io(io);
 
-	verity_submit_prefetch(v, io, bio_prio(bio));
+	verity_submit_prefetch(v, io, bio->bi_ioprio);
 
 	submit_bio_noacct(bio);
 
 	return DM_MAPIO_SUBMITTED;
 }
 
+static void verity_postsuspend(struct dm_target *ti)
+{
+	struct dm_verity *v = ti->private;
+	flush_workqueue(v->verify_wq);
+	dm_bufio_client_reset(v->bufio);
+}
+
 /*
  * Status: V (valid) or C (corruption found)
  */
@@ -899,6 +879,8 @@ static void verity_status(struct dm_target *ti, status_type_t type,
 				DMEMIT("%02x", v->salt[x]);
 		if (v->mode != DM_VERITY_MODE_EIO)
 			args++;
+		if (v->error_mode != DM_VERITY_MODE_EIO)
+			args++;
 		if (verity_fec_is_enabled(v))
 			args += DM_VERITY_OPTS_FEC;
 		if (v->zero_digest)
@@ -928,6 +910,19 @@ static void verity_status(struct dm_target *ti, status_type_t type,
 				BUG();
 			}
 		}
+		if (v->error_mode != DM_VERITY_MODE_EIO) {
+			DMEMIT(" ");
+			switch (v->error_mode) {
+			case DM_VERITY_MODE_RESTART:
+				DMEMIT(DM_VERITY_OPT_ERROR_RESTART);
+				break;
+			case DM_VERITY_MODE_PANIC:
+				DMEMIT(DM_VERITY_OPT_ERROR_PANIC);
+				break;
+			default:
+				BUG();
+			}
+		}
 		if (v->zero_digest)
 			DMEMIT(" " DM_VERITY_OPT_IGN_ZEROES);
 		if (v->validated_blocks)
@@ -980,6 +975,19 @@ static void verity_status(struct dm_target *ti, status_type_t type,
 				DMEMIT("invalid");
 			}
 		}
+		if (v->error_mode != DM_VERITY_MODE_EIO) {
+			DMEMIT(",verity_error_mode=");
+			switch (v->error_mode) {
+			case DM_VERITY_MODE_RESTART:
+				DMEMIT(DM_VERITY_OPT_ERROR_RESTART);
+				break;
+			case DM_VERITY_MODE_PANIC:
+				DMEMIT(DM_VERITY_OPT_ERROR_PANIC);
+				break;
+			default:
+				DMEMIT("invalid");
+			}
+		}
 		DMEMIT(";");
 		break;
 	}
@@ -991,7 +999,7 @@ static int verity_prepare_ioctl(struct dm_target *ti, struct block_device **bdev
 
 	*bdev = v->data_dev->bdev;
 
-	if (v->data_start || ti->len != bdev_nr_sectors(v->data_dev->bdev))
+	if (ti->len != bdev_nr_sectors(v->data_dev->bdev))
 		return 1;
 	return 0;
 }
@@ -1001,7 +1009,7 @@ static int verity_iterate_devices(struct dm_target *ti,
 {
 	struct dm_verity *v = ti->private;
 
-	return fn(ti, v->data_dev, v->data_start, ti->len, data);
+	return fn(ti, v->data_dev, 0, ti->len, data);
 }
 
 static void verity_io_hints(struct dm_target *ti, struct queue_limits *limits)
@@ -1014,9 +1022,52 @@ static void verity_io_hints(struct dm_target *ti, struct queue_limits *limits)
 	if (limits->physical_block_size < 1 << v->data_dev_block_bits)
 		limits->physical_block_size = 1 << v->data_dev_block_bits;
 
-	blk_limits_io_min(limits, limits->logical_block_size);
+	limits->io_min = limits->logical_block_size;
+
+	/*
+	 * Similar to what dm-crypt does, opt dm-verity out of support for
+	 * direct I/O that is aligned to less than the traditional direct I/O
+	 * alignment requirement of logical_block_size.  This prevents dm-verity
+	 * data blocks from crossing pages, eliminating various edge cases.
+	 */
+	limits->dma_alignment = limits->logical_block_size - 1;
+}
+
+#ifdef CONFIG_SECURITY
+
+static int verity_init_sig(struct dm_verity *v, const void *sig,
+			   size_t sig_size)
+{
+	v->sig_size = sig_size;
+
+	if (sig) {
+		v->root_digest_sig = kmemdup(sig, v->sig_size, GFP_KERNEL);
+		if (!v->root_digest_sig)
+			return -ENOMEM;
+	}
+
+	return 0;
 }
 
+static void verity_free_sig(struct dm_verity *v)
+{
+	kfree(v->root_digest_sig);
+}
+
+#else
+
+static inline int verity_init_sig(struct dm_verity *v, const void *sig,
+				  size_t sig_size)
+{
+	return 0;
+}
+
+static inline void verity_free_sig(struct dm_verity *v)
+{
+}
+
+#endif /* CONFIG_SECURITY */
+
 static void verity_dtr(struct dm_target *ti)
 {
 	struct dm_verity *v = ti->private;
@@ -1033,11 +1084,17 @@ static void verity_dtr(struct dm_target *ti)
 
 	kvfree(v->validated_blocks);
 	kfree(v->salt);
+	kfree(v->initial_hashstate);
 	kfree(v->root_digest);
 	kfree(v->zero_digest);
+	verity_free_sig(v);
 
-	if (v->tfm)
-		crypto_free_ahash(v->tfm);
+	if (v->ahash_tfm) {
+		static_branch_dec(&ahash_enabled);
+		crypto_free_ahash(v->ahash_tfm);
+	} else {
+		crypto_free_shash(v->shash_tfm);
+	}
 
 	kfree(v->alg_name);
 
@@ -1083,7 +1140,7 @@ static int verity_alloc_most_once(struct dm_verity *v)
 static int verity_alloc_zero_digest(struct dm_verity *v)
 {
 	int r = -ENOMEM;
-	struct ahash_request *req;
+	struct dm_verity_io *io;
 	u8 *zero_data;
 
 	v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL);
@@ -1091,9 +1148,9 @@ static int verity_alloc_zero_digest(struct dm_verity *v)
 	if (!v->zero_digest)
 		return r;
 
-	req = kmalloc(v->ahash_reqsize, GFP_KERNEL);
+	io = kmalloc(sizeof(*io) + v->hash_reqsize, GFP_KERNEL);
 
-	if (!req)
+	if (!io)
 		return r; /* verity_dtr will free zero_digest */
 
 	zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL);
@@ -1101,11 +1158,11 @@ static int verity_alloc_zero_digest(struct dm_verity *v)
 	if (!zero_data)
 		goto out;
 
-	r = verity_hash(v, req, zero_data, 1 << v->data_dev_block_bits,
+	r = verity_hash(v, io, zero_data, 1 << v->data_dev_block_bits,
 			v->zero_digest, true);
 
 out:
-	kfree(req);
+	kfree(io);
 	kfree(zero_data);
 
 	return r;
@@ -1133,6 +1190,25 @@ static int verity_parse_verity_mode(struct dm_verity *v, const char *arg_name)
 	return 0;
 }
 
+static inline bool verity_is_verity_error_mode(const char *arg_name)
+{
+	return (!strcasecmp(arg_name, DM_VERITY_OPT_ERROR_RESTART) ||
+		!strcasecmp(arg_name, DM_VERITY_OPT_ERROR_PANIC));
+}
+
+static int verity_parse_verity_error_mode(struct dm_verity *v, const char *arg_name)
+{
+	if (v->error_mode)
+		return -EINVAL;
+
+	if (!strcasecmp(arg_name, DM_VERITY_OPT_ERROR_RESTART))
+		v->error_mode = DM_VERITY_MODE_RESTART;
+	else if (!strcasecmp(arg_name, DM_VERITY_OPT_ERROR_PANIC))
+		v->error_mode = DM_VERITY_MODE_PANIC;
+
+	return 0;
+}
+
 static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
 				 struct dm_verity_sig_opts *verify_args,
 				 bool only_modifier_opts)
@@ -1167,6 +1243,16 @@ static int verity_parse_opt_args(struct dm_arg_set *as, struct dm_verity *v,
 			}
 			continue;
 
+		} else if (verity_is_verity_error_mode(arg_name)) {
+			if (only_modifier_opts)
+				continue;
+			r = verity_parse_verity_error_mode(v, arg_name);
+			if (r) {
+				ti->error = "Conflicting error handling parameters";
+				return r;
+			}
+			continue;
+
 		} else if (!strcasecmp(arg_name, DM_VERITY_OPT_IGN_ZEROES)) {
 			if (only_modifier_opts)
 				continue;
@@ -1226,6 +1312,113 @@ 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;
+	struct crypto_shash *shash = NULL;
+	const char *driver_name;
+
+	v->alg_name = kstrdup(alg_name, GFP_KERNEL);
+	if (!v->alg_name) {
+		ti->error = "Cannot allocate algorithm name";
+		return -ENOMEM;
+	}
+
+	/*
+	 * Allocate the hash transformation object that this dm-verity instance
+	 * will use.  The vast majority of dm-verity users use CPU-based
+	 * hashing, so when possible use the shash API to minimize the crypto
+	 * API overhead.  If the ahash API resolves to a different driver
+	 * (likely an off-CPU hardware offload), use ahash instead.  Also use
+	 * ahash if the obsolete dm-verity format with the appended salt is
+	 * being used, so that quirk only needs to be handled in one place.
+	 */
+	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);
+	}
+	driver_name = crypto_ahash_driver_name(ahash);
+	if (v->version >= 1 /* salt prepended, not appended? */) {
+		shash = crypto_alloc_shash(alg_name, 0, 0);
+		if (!IS_ERR(shash) &&
+		    strcmp(crypto_shash_driver_name(shash), driver_name) != 0) {
+			/*
+			 * ahash gave a different driver than shash, so probably
+			 * this is a case of real hardware offload.  Use ahash.
+			 */
+			crypto_free_shash(shash);
+			shash = NULL;
+		}
+	}
+	if (!IS_ERR_OR_NULL(shash)) {
+		crypto_free_ahash(ahash);
+		ahash = NULL;
+		v->shash_tfm = shash;
+		v->digest_size = crypto_shash_digestsize(shash);
+		v->hash_reqsize = sizeof(struct shash_desc) +
+				  crypto_shash_descsize(shash);
+		DMINFO("%s using shash \"%s\"", alg_name, driver_name);
+	} else {
+		v->ahash_tfm = ahash;
+		static_branch_inc(&ahash_enabled);
+		v->digest_size = crypto_ahash_digestsize(ahash);
+		v->hash_reqsize = sizeof(struct ahash_request) +
+				  crypto_ahash_reqsize(ahash);
+		DMINFO("%s using ahash \"%s\"", alg_name, driver_name);
+	}
+	if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) {
+		ti->error = "Digest size too big";
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int verity_setup_salt_and_hashstate(struct dm_verity *v, const char *arg)
+{
+	struct dm_target *ti = v->ti;
+
+	if (strcmp(arg, "-") != 0) {
+		v->salt_size = strlen(arg) / 2;
+		v->salt = kmalloc(v->salt_size, GFP_KERNEL);
+		if (!v->salt) {
+			ti->error = "Cannot allocate salt";
+			return -ENOMEM;
+		}
+		if (strlen(arg) != v->salt_size * 2 ||
+		    hex2bin(v->salt, arg, v->salt_size)) {
+			ti->error = "Invalid salt";
+			return -EINVAL;
+		}
+	}
+	if (v->shash_tfm) {
+		SHASH_DESC_ON_STACK(desc, v->shash_tfm);
+		int r;
+
+		/*
+		 * Compute the pre-salted hash state that can be passed to
+		 * crypto_shash_import() for each block later.
+		 */
+		v->initial_hashstate = kmalloc(
+			crypto_shash_statesize(v->shash_tfm), GFP_KERNEL);
+		if (!v->initial_hashstate) {
+			ti->error = "Cannot allocate initial hash state";
+			return -ENOMEM;
+		}
+		desc->tfm = v->shash_tfm;
+		r = crypto_shash_init(desc) ?:
+		    crypto_shash_update(desc, v->salt, v->salt_size) ?:
+		    crypto_shash_export(desc, v->initial_hashstate);
+		if (r) {
+			ti->error = "Cannot set up initial hash state";
+			return r;
+		}
+	}
+	return 0;
+}
+
 /*
  * Target parameters:
  *	<version>	The current format is version 1.
@@ -1350,38 +1543,9 @@ 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) {
@@ -1397,21 +1561,9 @@ static int verity_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 	root_hash_digest_to_validate = argv[8];
 
-	if (strcmp(argv[9], "-")) {
-		v->salt_size = strlen(argv[9]) / 2;
-		v->salt = kmalloc(v->salt_size, GFP_KERNEL);
-		if (!v->salt) {
-			ti->error = "Cannot allocate salt";
-			r = -ENOMEM;
-			goto bad;
-		}
-		if (strlen(argv[9]) != v->salt_size * 2 ||
-		    hex2bin(v->salt, argv[9], v->salt_size)) {
-			ti->error = "Invalid salt";
-			r = -EINVAL;
-			goto bad;
-		}
-	}
+	r = verity_setup_salt_and_hashstate(v, argv[9]);
+	if (r)
+		goto bad;
 
 	argv += 10;
 	argc -= 10;
@@ -1434,6 +1586,13 @@ static int verity_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		ti->error = "Root hash verification failed";
 		goto bad;
 	}
+
+	r = verity_init_sig(v, verify_args.sig, verify_args.sig_size);
+	if (r < 0) {
+		ti->error = "Cannot allocate root digest signature";
+		goto bad;
+	}
+
 	v->hash_per_block_bits =
 		__fls((1 << v->hash_dev_block_bits) / v->digest_size);
 
@@ -1513,8 +1672,7 @@ static int verity_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad;
 	}
 
-	ti->per_io_data_size = sizeof(struct dm_verity_io) +
-				v->ahash_reqsize + v->digest_size * 2;
+	ti->per_io_data_size = sizeof(struct dm_verity_io) + v->hash_reqsize;
 
 	r = verity_fec_ctr(v);
 	if (r)
@@ -1539,14 +1697,6 @@ bad:
 }
 
 /*
- * Check whether a DM target is a verity target.
- */
-bool dm_is_verity_target(struct dm_target *ti)
-{
-	return ti->type->module == THIS_MODULE;
-}
-
-/*
  * Get the verity mode (error behavior) of a verity target.
  *
  * Returns the verity mode of the target, or -EINVAL if 'ti' is not a verity
@@ -1584,21 +1734,104 @@ int dm_verity_get_root_digest(struct dm_target *ti, u8 **root_digest, unsigned i
 	return 0;
 }
 
+#ifdef CONFIG_SECURITY
+
+#ifdef CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG
+
+static int verity_security_set_signature(struct block_device *bdev,
+					 struct dm_verity *v)
+{
+	/*
+	 * if the dm-verity target is unsigned, v->root_digest_sig will
+	 * be NULL, and the hook call is still required to let LSMs mark
+	 * the device as unsigned. This information is crucial for LSMs to
+	 * block operations such as execution on unsigned files
+	 */
+	return security_bdev_setintegrity(bdev,
+					  LSM_INT_DMVERITY_SIG_VALID,
+					  v->root_digest_sig,
+					  v->sig_size);
+}
+
+#else
+
+static inline int verity_security_set_signature(struct block_device *bdev,
+						struct dm_verity *v)
+{
+	return 0;
+}
+
+#endif /* CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG */
+
+/*
+ * Expose verity target's root hash and signature data to LSMs before resume.
+ *
+ * Returns 0 on success, or -ENOMEM if the system is out of memory.
+ */
+static int verity_preresume(struct dm_target *ti)
+{
+	struct block_device *bdev;
+	struct dm_verity_digest root_digest;
+	struct dm_verity *v;
+	int r;
+
+	v = ti->private;
+	bdev = dm_disk(dm_table_get_md(ti->table))->part0;
+	root_digest.digest = v->root_digest;
+	root_digest.digest_len = v->digest_size;
+	if (static_branch_unlikely(&ahash_enabled) && !v->shash_tfm)
+		root_digest.alg = crypto_ahash_alg_name(v->ahash_tfm);
+	else
+		root_digest.alg = crypto_shash_alg_name(v->shash_tfm);
+
+	r = security_bdev_setintegrity(bdev, LSM_INT_DMVERITY_ROOTHASH, &root_digest,
+				       sizeof(root_digest));
+	if (r)
+		return r;
+
+	r =  verity_security_set_signature(bdev, v);
+	if (r)
+		goto bad;
+
+	return 0;
+
+bad:
+
+	security_bdev_setintegrity(bdev, LSM_INT_DMVERITY_ROOTHASH, NULL, 0);
+
+	return r;
+}
+
+#endif /* CONFIG_SECURITY */
+
 static struct target_type verity_target = {
 	.name		= "verity",
+/* Note: the LSMs depend on the singleton and immutable features */
 	.features	= DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE,
-	.version	= {1, 10, 0},
+	.version	= {1, 11, 0},
 	.module		= THIS_MODULE,
 	.ctr		= verity_ctr,
 	.dtr		= verity_dtr,
 	.map		= verity_map,
+	.postsuspend	= verity_postsuspend,
 	.status		= verity_status,
 	.prepare_ioctl	= verity_prepare_ioctl,
 	.iterate_devices = verity_iterate_devices,
 	.io_hints	= verity_io_hints,
+#ifdef CONFIG_SECURITY
+	.preresume	= verity_preresume,
+#endif /* CONFIG_SECURITY */
 };
 module_dm(verity);
 
+/*
+ * Check whether a DM target is a verity target.
+ */
+bool dm_is_verity_target(struct dm_target *ti)
+{
+	return ti->type == &verity_target;
+}
+
 MODULE_AUTHOR("Mikulas Patocka <mpatocka@redhat.com>");
 MODULE_AUTHOR("Mandeep Baines <msb@chromium.org>");
 MODULE_AUTHOR("Will Drewry <wad@chromium.org>");