1 files changed, 223 insertions, 365 deletions

diff --git a/crypto/xts.c b/crypto/xts.c
index d86c11a8c882..3da8f5e053d6 100644
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -1,18 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* XTS: as defined in IEEE1619/D16
  *	http://grouper.ieee.org/groups/1619/email/pdf00086.pdf
- *	(sector sizes which are not a multiple of 16 bytes are,
- *	however currently unsupported)
  *
  * Copyright (c) 2007 Rik Snel <rsnel@cube.dyndns.org>
  *
  * Based on ecb.c
  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 2 of the License, or (at your option)
- * any later version.
  */
+#include <crypto/internal/cipher.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/scatterwalk.h>
 #include <linux/err.h>
@@ -26,39 +21,27 @@
 #include <crypto/b128ops.h>
 #include <crypto/gf128mul.h>
 
-#define XTS_BUFFER_SIZE 128u
-
-struct priv {
+struct xts_tfm_ctx {
 	struct crypto_skcipher *child;
 	struct crypto_cipher *tweak;
 };
 
 struct xts_instance_ctx {
 	struct crypto_skcipher_spawn spawn;
-	char name[CRYPTO_MAX_ALG_NAME];
+	struct crypto_cipher_spawn tweak_spawn;
 };
 
-struct rctx {
-	le128 buf[XTS_BUFFER_SIZE / sizeof(le128)];
-
+struct xts_request_ctx {
 	le128 t;
-
-	le128 *ext;
-
-	struct scatterlist srcbuf[2];
-	struct scatterlist dstbuf[2];
-	struct scatterlist *src;
-	struct scatterlist *dst;
-
-	unsigned int left;
-
+	struct scatterlist *tail;
+	struct scatterlist sg[2];
 	struct skcipher_request subreq;
 };
 
-static int setkey(struct crypto_skcipher *parent, const u8 *key,
-		  unsigned int keylen)
+static int xts_setkey(struct crypto_skcipher *parent, const u8 *key,
+		      unsigned int keylen)
 {
-	struct priv *ctx = crypto_skcipher_ctx(parent);
+	struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(parent);
 	struct crypto_skcipher *child;
 	struct crypto_cipher *tweak;
 	int err;
@@ -79,8 +62,6 @@ static int setkey(struct crypto_skcipher *parent, const u8 *key,
 	crypto_cipher_set_flags(tweak, crypto_skcipher_get_flags(parent) &
 				       CRYPTO_TFM_REQ_MASK);
 	err = crypto_cipher_setkey(tweak, key + keylen, keylen);
-	crypto_skcipher_set_flags(parent, crypto_cipher_get_flags(tweak) &
-					  CRYPTO_TFM_RES_MASK);
 	if (err)
 		return err;
 
@@ -89,355 +70,233 @@ static int setkey(struct crypto_skcipher *parent, const u8 *key,
 	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
 					 CRYPTO_TFM_REQ_MASK);
-	err = crypto_skcipher_setkey(child, key, keylen);
-	crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
-					  CRYPTO_TFM_RES_MASK);
-
-	return err;
+	return crypto_skcipher_setkey(child, key, keylen);
 }
 
-static int post_crypt(struct skcipher_request *req)
+/*
+ * We compute the tweak masks twice (both before and after the ECB encryption or
+ * decryption) to avoid having to allocate a temporary buffer and/or make
+ * mutliple calls to the 'ecb(..)' instance, which usually would be slower than
+ * just doing the gf128mul_x_ble() calls again.
+ */
+static int xts_xor_tweak(struct skcipher_request *req, bool second_pass,
+			 bool enc)
 {
-	struct rctx *rctx = skcipher_request_ctx(req);
-	le128 *buf = rctx->ext ?: rctx->buf;
-	struct skcipher_request *subreq;
+	struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	const bool cts = (req->cryptlen % XTS_BLOCK_SIZE);
 	const int bs = XTS_BLOCK_SIZE;
 	struct skcipher_walk w;
-	struct scatterlist *sg;
-	unsigned offset;
+	le128 t = rctx->t;
 	int err;
 
-	subreq = &rctx->subreq;
-	err = skcipher_walk_virt(&w, subreq, false);
-
-	while (w.nbytes) {
-		unsigned int avail = w.nbytes;
-		le128 *wdst;
-
-		wdst = w.dst.virt.addr;
-
-		do {
-			le128_xor(wdst, buf++, wdst);
-			wdst++;
-		} while ((avail -= bs) >= bs);
-
-		err = skcipher_walk_done(&w, avail);
-	}
-
-	rctx->left -= subreq->cryptlen;
-
-	if (err || !rctx->left)
-		goto out;
-
-	rctx->dst = rctx->dstbuf;
-
-	scatterwalk_done(&w.out, 0, 1);
-	sg = w.out.sg;
-	offset = w.out.offset;
-
-	if (rctx->dst != sg) {
-		rctx->dst[0] = *sg;
-		sg_unmark_end(rctx->dst);
-		scatterwalk_crypto_chain(rctx->dst, sg_next(sg), 0, 2);
+	if (second_pass) {
+		req = &rctx->subreq;
+		/* set to our TFM to enforce correct alignment: */
+		skcipher_request_set_tfm(req, tfm);
 	}
-	rctx->dst[0].length -= offset - sg->offset;
-	rctx->dst[0].offset = offset;
-
-out:
-	return err;
-}
-
-static int pre_crypt(struct skcipher_request *req)
-{
-	struct rctx *rctx = skcipher_request_ctx(req);
-	le128 *buf = rctx->ext ?: rctx->buf;
-	struct skcipher_request *subreq;
-	const int bs = XTS_BLOCK_SIZE;
-	struct skcipher_walk w;
-	struct scatterlist *sg;
-	unsigned cryptlen;
-	unsigned offset;
-	bool more;
-	int err;
-
-	subreq = &rctx->subreq;
-	cryptlen = subreq->cryptlen;
-
-	more = rctx->left > cryptlen;
-	if (!more)
-		cryptlen = rctx->left;
-
-	skcipher_request_set_crypt(subreq, rctx->src, rctx->dst,
-				   cryptlen, NULL);
-
-	err = skcipher_walk_virt(&w, subreq, false);
+	err = skcipher_walk_virt(&w, req, false);
 
 	while (w.nbytes) {
 		unsigned int avail = w.nbytes;
-		le128 *wsrc;
+		const le128 *wsrc;
 		le128 *wdst;
 
 		wsrc = w.src.virt.addr;
 		wdst = w.dst.virt.addr;
 
 		do {
-			*buf++ = rctx->t;
-			le128_xor(wdst++, &rctx->t, wsrc++);
-			gf128mul_x_ble(&rctx->t, &rctx->t);
+			if (unlikely(cts) &&
+			    w.total - w.nbytes + avail < 2 * XTS_BLOCK_SIZE) {
+				if (!enc) {
+					if (second_pass)
+						rctx->t = t;
+					gf128mul_x_ble(&t, &t);
+				}
+				le128_xor(wdst, &t, wsrc);
+				if (enc && second_pass)
+					gf128mul_x_ble(&rctx->t, &t);
+				skcipher_walk_done(&w, avail - bs);
+				return 0;
+			}
+
+			le128_xor(wdst++, &t, wsrc++);
+			gf128mul_x_ble(&t, &t);
 		} while ((avail -= bs) >= bs);
 
 		err = skcipher_walk_done(&w, avail);
 	}
 
-	skcipher_request_set_crypt(subreq, rctx->dst, rctx->dst,
-				   cryptlen, NULL);
-
-	if (err || !more)
-		goto out;
-
-	rctx->src = rctx->srcbuf;
-
-	scatterwalk_done(&w.in, 0, 1);
-	sg = w.in.sg;
-	offset = w.in.offset;
-
-	if (rctx->src != sg) {
-		rctx->src[0] = *sg;
-		sg_unmark_end(rctx->src);
-		scatterwalk_crypto_chain(rctx->src, sg_next(sg), 0, 2);
-	}
-	rctx->src[0].length -= offset - sg->offset;
-	rctx->src[0].offset = offset;
-
-out:
 	return err;
 }
 
-static int init_crypt(struct skcipher_request *req, crypto_completion_t done)
+static int xts_xor_tweak_pre(struct skcipher_request *req, bool enc)
 {
-	struct priv *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
-	struct rctx *rctx = skcipher_request_ctx(req);
-	struct skcipher_request *subreq;
-	gfp_t gfp;
-
-	subreq = &rctx->subreq;
-	skcipher_request_set_tfm(subreq, ctx->child);
-	skcipher_request_set_callback(subreq, req->base.flags, done, req);
-
-	gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
-							   GFP_ATOMIC;
-	rctx->ext = NULL;
-
-	subreq->cryptlen = XTS_BUFFER_SIZE;
-	if (req->cryptlen > XTS_BUFFER_SIZE) {
-		unsigned int n = min(req->cryptlen, (unsigned int)PAGE_SIZE);
-
-		rctx->ext = kmalloc(n, gfp);
-		if (rctx->ext)
-			subreq->cryptlen = n;
-	}
-
-	rctx->src = req->src;
-	rctx->dst = req->dst;
-	rctx->left = req->cryptlen;
-
-	/* calculate first value of T */
-	crypto_cipher_encrypt_one(ctx->tweak, (u8 *)&rctx->t, req->iv);
-
-	return 0;
+	return xts_xor_tweak(req, false, enc);
 }
 
-static void exit_crypt(struct skcipher_request *req)
+static int xts_xor_tweak_post(struct skcipher_request *req, bool enc)
 {
-	struct rctx *rctx = skcipher_request_ctx(req);
-
-	rctx->left = 0;
-
-	if (rctx->ext)
-		kzfree(rctx->ext);
+	return xts_xor_tweak(req, true, enc);
 }
 
-static int do_encrypt(struct skcipher_request *req, int err)
+static void xts_cts_done(void *data, int err)
 {
-	struct rctx *rctx = skcipher_request_ctx(req);
-	struct skcipher_request *subreq;
-
-	subreq = &rctx->subreq;
+	struct skcipher_request *req = data;
+	le128 b;
 
-	while (!err && rctx->left) {
-		err = pre_crypt(req) ?:
-		      crypto_skcipher_encrypt(subreq) ?:
-		      post_crypt(req);
+	if (!err) {
+		struct xts_request_ctx *rctx = skcipher_request_ctx(req);
 
-		if (err == -EINPROGRESS ||
-		    (err == -EBUSY &&
-		     req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
-			return err;
+		scatterwalk_map_and_copy(&b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
+		le128_xor(&b, &rctx->t, &b);
+		scatterwalk_map_and_copy(&b, rctx->tail, 0, XTS_BLOCK_SIZE, 1);
 	}
 
-	exit_crypt(req);
-	return err;
+	skcipher_request_complete(req, err);
 }
 
-static void encrypt_done(struct crypto_async_request *areq, int err)
+static int xts_cts_final(struct skcipher_request *req,
+			 int (*crypt)(struct skcipher_request *req))
 {
-	struct skcipher_request *req = areq->data;
-	struct skcipher_request *subreq;
-	struct rctx *rctx;
+	const struct xts_tfm_ctx *ctx =
+		crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+	int offset = req->cryptlen & ~(XTS_BLOCK_SIZE - 1);
+	struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+	struct skcipher_request *subreq = &rctx->subreq;
+	int tail = req->cryptlen % XTS_BLOCK_SIZE;
+	le128 b[2];
+	int err;
 
-	rctx = skcipher_request_ctx(req);
+	rctx->tail = scatterwalk_ffwd(rctx->sg, req->dst,
+				      offset - XTS_BLOCK_SIZE);
 
-	if (err == -EINPROGRESS) {
-		if (rctx->left != req->cryptlen)
-			return;
-		goto out;
-	}
+	scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
+	b[1] = b[0];
+	scatterwalk_map_and_copy(b, req->src, offset, tail, 0);
 
-	subreq = &rctx->subreq;
-	subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
+	le128_xor(b, &rctx->t, b);
 
-	err = do_encrypt(req, err ?: post_crypt(req));
-	if (rctx->left)
-		return;
+	scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE + tail, 1);
 
-out:
-	skcipher_request_complete(req, err);
-}
+	skcipher_request_set_tfm(subreq, ctx->child);
+	skcipher_request_set_callback(subreq, req->base.flags, xts_cts_done,
+				      req);
+	skcipher_request_set_crypt(subreq, rctx->tail, rctx->tail,
+				   XTS_BLOCK_SIZE, NULL);
 
-static int encrypt(struct skcipher_request *req)
-{
-	return do_encrypt(req, init_crypt(req, encrypt_done));
+	err = crypt(subreq);
+	if (err)
+		return err;
+
+	scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 0);
+	le128_xor(b, &rctx->t, b);
+	scatterwalk_map_and_copy(b, rctx->tail, 0, XTS_BLOCK_SIZE, 1);
+
+	return 0;
 }
 
-static int do_decrypt(struct skcipher_request *req, int err)
+static void xts_encrypt_done(void *data, int err)
 {
-	struct rctx *rctx = skcipher_request_ctx(req);
-	struct skcipher_request *subreq;
+	struct skcipher_request *req = data;
 
-	subreq = &rctx->subreq;
+	if (!err) {
+		struct xts_request_ctx *rctx = skcipher_request_ctx(req);
 
-	while (!err && rctx->left) {
-		err = pre_crypt(req) ?:
-		      crypto_skcipher_decrypt(subreq) ?:
-		      post_crypt(req);
+		rctx->subreq.base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
+		err = xts_xor_tweak_post(req, true);
 
-		if (err == -EINPROGRESS ||
-		    (err == -EBUSY &&
-		     req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
-			return err;
+		if (!err && unlikely(req->cryptlen % XTS_BLOCK_SIZE)) {
+			err = xts_cts_final(req, crypto_skcipher_encrypt);
+			if (err == -EINPROGRESS || err == -EBUSY)
+				return;
+		}
 	}
 
-	exit_crypt(req);
-	return err;
+	skcipher_request_complete(req, err);
 }
 
-static void decrypt_done(struct crypto_async_request *areq, int err)
+static void xts_decrypt_done(void *data, int err)
 {
-	struct skcipher_request *req = areq->data;
-	struct skcipher_request *subreq;
-	struct rctx *rctx;
+	struct skcipher_request *req = data;
 
-	rctx = skcipher_request_ctx(req);
+	if (!err) {
+		struct xts_request_ctx *rctx = skcipher_request_ctx(req);
 
-	if (err == -EINPROGRESS) {
-		if (rctx->left != req->cryptlen)
-			return;
-		goto out;
-	}
-
-	subreq = &rctx->subreq;
-	subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
+		rctx->subreq.base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
+		err = xts_xor_tweak_post(req, false);
 
-	err = do_decrypt(req, err ?: post_crypt(req));
-	if (rctx->left)
-		return;
+		if (!err && unlikely(req->cryptlen % XTS_BLOCK_SIZE)) {
+			err = xts_cts_final(req, crypto_skcipher_decrypt);
+			if (err == -EINPROGRESS || err == -EBUSY)
+				return;
+		}
+	}
 
-out:
 	skcipher_request_complete(req, err);
 }
 
-static int decrypt(struct skcipher_request *req)
+static int xts_init_crypt(struct skcipher_request *req,
+			  crypto_completion_t compl)
 {
-	return do_decrypt(req, init_crypt(req, decrypt_done));
-}
+	const struct xts_tfm_ctx *ctx =
+		crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
+	struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+	struct skcipher_request *subreq = &rctx->subreq;
 
-int xts_crypt(struct blkcipher_desc *desc, struct scatterlist *sdst,
-	      struct scatterlist *ssrc, unsigned int nbytes,
-	      struct xts_crypt_req *req)
-{
-	const unsigned int bsize = XTS_BLOCK_SIZE;
-	const unsigned int max_blks = req->tbuflen / bsize;
-	struct blkcipher_walk walk;
-	unsigned int nblocks;
-	le128 *src, *dst, *t;
-	le128 *t_buf = req->tbuf;
-	int err, i;
-
-	BUG_ON(max_blks < 1);
-
-	blkcipher_walk_init(&walk, sdst, ssrc, nbytes);
-
-	err = blkcipher_walk_virt(desc, &walk);
-	nbytes = walk.nbytes;
-	if (!nbytes)
-		return err;
+	if (req->cryptlen < XTS_BLOCK_SIZE)
+		return -EINVAL;
 
-	nblocks = min(nbytes / bsize, max_blks);
-	src = (le128 *)walk.src.virt.addr;
-	dst = (le128 *)walk.dst.virt.addr;
+	skcipher_request_set_tfm(subreq, ctx->child);
+	skcipher_request_set_callback(subreq, req->base.flags, compl, req);
+	skcipher_request_set_crypt(subreq, req->dst, req->dst,
+				   req->cryptlen & ~(XTS_BLOCK_SIZE - 1), NULL);
 
 	/* calculate first value of T */
-	req->tweak_fn(req->tweak_ctx, (u8 *)&t_buf[0], walk.iv);
-
-	i = 0;
-	goto first;
+	crypto_cipher_encrypt_one(ctx->tweak, (u8 *)&rctx->t, req->iv);
 
-	for (;;) {
-		do {
-			for (i = 0; i < nblocks; i++) {
-				gf128mul_x_ble(&t_buf[i], t);
-first:
-				t = &t_buf[i];
+	return 0;
+}
 
-				/* PP <- T xor P */
-				le128_xor(dst + i, t, src + i);
-			}
+static int xts_encrypt(struct skcipher_request *req)
+{
+	struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+	struct skcipher_request *subreq = &rctx->subreq;
+	int err;
 
-			/* CC <- E(Key2,PP) */
-			req->crypt_fn(req->crypt_ctx, (u8 *)dst,
-				      nblocks * bsize);
+	err = xts_init_crypt(req, xts_encrypt_done) ?:
+	      xts_xor_tweak_pre(req, true) ?:
+	      crypto_skcipher_encrypt(subreq) ?:
+	      xts_xor_tweak_post(req, true);
 
-			/* C <- T xor CC */
-			for (i = 0; i < nblocks; i++)
-				le128_xor(dst + i, dst + i, &t_buf[i]);
+	if (err || likely((req->cryptlen % XTS_BLOCK_SIZE) == 0))
+		return err;
 
-			src += nblocks;
-			dst += nblocks;
-			nbytes -= nblocks * bsize;
-			nblocks = min(nbytes / bsize, max_blks);
-		} while (nblocks > 0);
+	return xts_cts_final(req, crypto_skcipher_encrypt);
+}
 
-		*(le128 *)walk.iv = *t;
+static int xts_decrypt(struct skcipher_request *req)
+{
+	struct xts_request_ctx *rctx = skcipher_request_ctx(req);
+	struct skcipher_request *subreq = &rctx->subreq;
+	int err;
 
-		err = blkcipher_walk_done(desc, &walk, nbytes);
-		nbytes = walk.nbytes;
-		if (!nbytes)
-			break;
+	err = xts_init_crypt(req, xts_decrypt_done) ?:
+	      xts_xor_tweak_pre(req, false) ?:
+	      crypto_skcipher_decrypt(subreq) ?:
+	      xts_xor_tweak_post(req, false);
 
-		nblocks = min(nbytes / bsize, max_blks);
-		src = (le128 *)walk.src.virt.addr;
-		dst = (le128 *)walk.dst.virt.addr;
-	}
+	if (err || likely((req->cryptlen % XTS_BLOCK_SIZE) == 0))
+		return err;
 
-	return err;
+	return xts_cts_final(req, crypto_skcipher_decrypt);
 }
-EXPORT_SYMBOL_GPL(xts_crypt);
 
-static int init_tfm(struct crypto_skcipher *tfm)
+static int xts_init_tfm(struct crypto_skcipher *tfm)
 {
 	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
 	struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
-	struct priv *ctx = crypto_skcipher_ctx(tfm);
+	struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct crypto_skcipher *child;
 	struct crypto_cipher *tweak;
 
@@ -447,7 +306,7 @@ static int init_tfm(struct crypto_skcipher *tfm)
 
 	ctx->child = child;
 
-	tweak = crypto_alloc_cipher(ictx->name, 0, 0);
+	tweak = crypto_spawn_cipher(&ictx->tweak_spawn);
 	if (IS_ERR(tweak)) {
 		crypto_free_skcipher(ctx->child);
 		return PTR_ERR(tweak);
@@ -456,41 +315,41 @@ static int init_tfm(struct crypto_skcipher *tfm)
 	ctx->tweak = tweak;
 
 	crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(child) +
-					 sizeof(struct rctx));
+					 sizeof(struct xts_request_ctx));
 
 	return 0;
 }
 
-static void exit_tfm(struct crypto_skcipher *tfm)
+static void xts_exit_tfm(struct crypto_skcipher *tfm)
 {
-	struct priv *ctx = crypto_skcipher_ctx(tfm);
+	struct xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
 
 	crypto_free_skcipher(ctx->child);
 	crypto_free_cipher(ctx->tweak);
 }
 
-static void free(struct skcipher_instance *inst)
+static void xts_free_instance(struct skcipher_instance *inst)
 {
-	crypto_drop_skcipher(skcipher_instance_ctx(inst));
+	struct xts_instance_ctx *ictx = skcipher_instance_ctx(inst);
+
+	crypto_drop_skcipher(&ictx->spawn);
+	crypto_drop_cipher(&ictx->tweak_spawn);
 	kfree(inst);
 }
 
-static int create(struct crypto_template *tmpl, struct rtattr **tb)
+static int xts_create(struct crypto_template *tmpl, struct rtattr **tb)
 {
+	struct skcipher_alg_common *alg;
+	char name[CRYPTO_MAX_ALG_NAME];
 	struct skcipher_instance *inst;
-	struct crypto_attr_type *algt;
 	struct xts_instance_ctx *ctx;
-	struct skcipher_alg *alg;
 	const char *cipher_name;
 	u32 mask;
 	int err;
 
-	algt = crypto_get_attr_type(tb);
-	if (IS_ERR(algt))
-		return PTR_ERR(algt);
-
-	if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
-		return -EINVAL;
+	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
+	if (err)
+		return err;
 
 	cipher_name = crypto_attr_alg_name(tb[1]);
 	if (IS_ERR(cipher_name))
@@ -502,38 +361,35 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 
 	ctx = skcipher_instance_ctx(inst);
 
-	crypto_set_skcipher_spawn(&ctx->spawn, skcipher_crypto_instance(inst));
-
-	mask = crypto_requires_off(algt->type, algt->mask,
-				   CRYPTO_ALG_NEED_FALLBACK |
-				   CRYPTO_ALG_ASYNC);
-
-	err = crypto_grab_skcipher(&ctx->spawn, cipher_name, 0, mask);
-	if (err == -ENOENT) {
+	err = crypto_grab_skcipher(&ctx->spawn, skcipher_crypto_instance(inst),
+				   cipher_name, 0, mask);
+	if (err == -ENOENT && memcmp(cipher_name, "ecb(", 4)) {
 		err = -ENAMETOOLONG;
-		if (snprintf(ctx->name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
+		if (snprintf(name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
 			     cipher_name) >= CRYPTO_MAX_ALG_NAME)
 			goto err_free_inst;
 
-		err = crypto_grab_skcipher(&ctx->spawn, ctx->name, 0, mask);
+		err = crypto_grab_skcipher(&ctx->spawn,
+					   skcipher_crypto_instance(inst),
+					   name, 0, mask);
 	}
 
 	if (err)
 		goto err_free_inst;
 
-	alg = crypto_skcipher_spawn_alg(&ctx->spawn);
+	alg = crypto_spawn_skcipher_alg_common(&ctx->spawn);
 
 	err = -EINVAL;
 	if (alg->base.cra_blocksize != XTS_BLOCK_SIZE)
-		goto err_drop_spawn;
+		goto err_free_inst;
 
-	if (crypto_skcipher_alg_ivsize(alg))
-		goto err_drop_spawn;
+	if (alg->ivsize)
+		goto err_free_inst;
 
 	err = crypto_inst_setname(skcipher_crypto_instance(inst), "xts",
 				  &alg->base);
 	if (err)
-		goto err_drop_spawn;
+		goto err_free_inst;
 
 	err = -EINVAL;
 	cipher_name = alg->base.cra_name;
@@ -541,78 +397,80 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb)
 	/* Alas we screwed up the naming so we have to mangle the
 	 * cipher name.
 	 */
-	if (!strncmp(cipher_name, "ecb(", 4)) {
-		unsigned len;
+	if (!memcmp(cipher_name, "ecb(", 4)) {
+		int len;
 
-		len = strlcpy(ctx->name, cipher_name + 4, sizeof(ctx->name));
-		if (len < 2 || len >= sizeof(ctx->name))
-			goto err_drop_spawn;
+		len = strscpy(name, cipher_name + 4, sizeof(name));
+		if (len < 2)
+			goto err_free_inst;
 
-		if (ctx->name[len - 1] != ')')
-			goto err_drop_spawn;
+		if (name[len - 1] != ')')
+			goto err_free_inst;
 
-		ctx->name[len - 1] = 0;
+		name[len - 1] = 0;
 
 		if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
-			     "xts(%s)", ctx->name) >= CRYPTO_MAX_ALG_NAME)
-			return -ENAMETOOLONG;
+			     "xts(%s)", name) >= CRYPTO_MAX_ALG_NAME) {
+			err = -ENAMETOOLONG;
+			goto err_free_inst;
+		}
 	} else
-		goto err_drop_spawn;
+		goto err_free_inst;
+
+	err = crypto_grab_cipher(&ctx->tweak_spawn,
+				 skcipher_crypto_instance(inst), name, 0, mask);
+	if (err)
+		goto err_free_inst;
 
-	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 	inst->alg.base.cra_priority = alg->base.cra_priority;
 	inst->alg.base.cra_blocksize = XTS_BLOCK_SIZE;
 	inst->alg.base.cra_alignmask = alg->base.cra_alignmask |
 				       (__alignof__(u64) - 1);
 
 	inst->alg.ivsize = XTS_BLOCK_SIZE;
-	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) * 2;
-	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) * 2;
+	inst->alg.min_keysize = alg->min_keysize * 2;
+	inst->alg.max_keysize = alg->max_keysize * 2;
 
-	inst->alg.base.cra_ctxsize = sizeof(struct priv);
+	inst->alg.base.cra_ctxsize = sizeof(struct xts_tfm_ctx);
 
-	inst->alg.init = init_tfm;
-	inst->alg.exit = exit_tfm;
+	inst->alg.init = xts_init_tfm;
+	inst->alg.exit = xts_exit_tfm;
 
-	inst->alg.setkey = setkey;
-	inst->alg.encrypt = encrypt;
-	inst->alg.decrypt = decrypt;
+	inst->alg.setkey = xts_setkey;
+	inst->alg.encrypt = xts_encrypt;
+	inst->alg.decrypt = xts_decrypt;
 
-	inst->free = free;
+	inst->free = xts_free_instance;
 
 	err = skcipher_register_instance(tmpl, inst);
-	if (err)
-		goto err_drop_spawn;
-
-out:
-	return err;
-
-err_drop_spawn:
-	crypto_drop_skcipher(&ctx->spawn);
+	if (err) {
 err_free_inst:
-	kfree(inst);
-	goto out;
+		xts_free_instance(inst);
+	}
+	return err;
 }
 
-static struct crypto_template crypto_tmpl = {
+static struct crypto_template xts_tmpl = {
 	.name = "xts",
-	.create = create,
+	.create = xts_create,
 	.module = THIS_MODULE,
 };
 
-static int __init crypto_module_init(void)
+static int __init xts_module_init(void)
 {
-	return crypto_register_template(&crypto_tmpl);
+	return crypto_register_template(&xts_tmpl);
 }
 
-static void __exit crypto_module_exit(void)
+static void __exit xts_module_exit(void)
 {
-	crypto_unregister_template(&crypto_tmpl);
+	crypto_unregister_template(&xts_tmpl);
 }
 
-module_init(crypto_module_init);
-module_exit(crypto_module_exit);
+module_init(xts_module_init);
+module_exit(xts_module_exit);
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("XTS block cipher mode");
 MODULE_ALIAS_CRYPTO("xts");
+MODULE_IMPORT_NS("CRYPTO_INTERNAL");
+MODULE_SOFTDEP("pre: ecb");