1 files changed, 132 insertions, 697 deletions

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index 43839b00fe6c..8ae4170aaeb4 100644
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -10,6 +10,21 @@
  * Software Foundation; either version 2 of the License, or (at your option)
  * any later version.
  *
+ * The following concept of the memory management is used:
+ *
+ * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is
+ * filled by user space with the data submitted via sendpage/sendmsg. Filling
+ * up the TX SGL does not cause a crypto operation -- the data will only be
+ * tracked by the kernel. Upon receipt of one recvmsg call, the caller must
+ * provide a buffer which is tracked with the RX SGL.
+ *
+ * During the processing of the recvmsg operation, the cipher request is
+ * allocated and prepared. As part of the recvmsg operation, the processed
+ * TX buffers are extracted from the TX SGL into a separate SGL.
+ *
+ * After the completion of the crypto operation, the RX SGL and the cipher
+ * request is released. The extracted TX SGL parts are released together with
+ * the RX SGL release.
  */
 
 #include <crypto/scatterwalk.h>
@@ -18,279 +33,16 @@
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/kernel.h>
-#include <linux/sched/signal.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/net.h>
 #include <net/sock.h>
 
-struct skcipher_sg_list {
-	struct list_head list;
-
-	int cur;
-
-	struct scatterlist sg[0];
-};
-
 struct skcipher_tfm {
 	struct crypto_skcipher *skcipher;
 	bool has_key;
 };
 
-struct skcipher_ctx {
-	struct list_head tsgl;
-	struct af_alg_sgl rsgl;
-
-	void *iv;
-
-	struct af_alg_completion completion;
-
-	atomic_t inflight;
-	size_t used;
-
-	unsigned int len;
-	bool more;
-	bool merge;
-	bool enc;
-
-	struct skcipher_request req;
-};
-
-struct skcipher_async_rsgl {
-	struct af_alg_sgl sgl;
-	struct list_head list;
-};
-
-struct skcipher_async_req {
-	struct kiocb *iocb;
-	struct skcipher_async_rsgl first_sgl;
-	struct list_head list;
-	struct scatterlist *tsg;
-	atomic_t *inflight;
-	struct skcipher_request req;
-};
-
-#define MAX_SGL_ENTS ((4096 - sizeof(struct skcipher_sg_list)) / \
-		      sizeof(struct scatterlist) - 1)
-
-static void skcipher_free_async_sgls(struct skcipher_async_req *sreq)
-{
-	struct skcipher_async_rsgl *rsgl, *tmp;
-	struct scatterlist *sgl;
-	struct scatterlist *sg;
-	int i, n;
-
-	list_for_each_entry_safe(rsgl, tmp, &sreq->list, list) {
-		af_alg_free_sg(&rsgl->sgl);
-		if (rsgl != &sreq->first_sgl)
-			kfree(rsgl);
-	}
-	sgl = sreq->tsg;
-	n = sg_nents(sgl);
-	for_each_sg(sgl, sg, n, i)
-		put_page(sg_page(sg));
-
-	kfree(sreq->tsg);
-}
-
-static void skcipher_async_cb(struct crypto_async_request *req, int err)
-{
-	struct skcipher_async_req *sreq = req->data;
-	struct kiocb *iocb = sreq->iocb;
-
-	atomic_dec(sreq->inflight);
-	skcipher_free_async_sgls(sreq);
-	kzfree(sreq);
-	iocb->ki_complete(iocb, err, err);
-}
-
-static inline int skcipher_sndbuf(struct sock *sk)
-{
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-
-	return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
-			  ctx->used, 0);
-}
-
-static inline bool skcipher_writable(struct sock *sk)
-{
-	return PAGE_SIZE <= skcipher_sndbuf(sk);
-}
-
-static int skcipher_alloc_sgl(struct sock *sk)
-{
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-	struct skcipher_sg_list *sgl;
-	struct scatterlist *sg = NULL;
-
-	sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
-	if (!list_empty(&ctx->tsgl))
-		sg = sgl->sg;
-
-	if (!sg || sgl->cur >= MAX_SGL_ENTS) {
-		sgl = sock_kmalloc(sk, sizeof(*sgl) +
-				       sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1),
-				   GFP_KERNEL);
-		if (!sgl)
-			return -ENOMEM;
-
-		sg_init_table(sgl->sg, MAX_SGL_ENTS + 1);
-		sgl->cur = 0;
-
-		if (sg)
-			sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg);
-
-		list_add_tail(&sgl->list, &ctx->tsgl);
-	}
-
-	return 0;
-}
-
-static void skcipher_pull_sgl(struct sock *sk, size_t used, int put)
-{
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-	struct skcipher_sg_list *sgl;
-	struct scatterlist *sg;
-	int i;
-
-	while (!list_empty(&ctx->tsgl)) {
-		sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list,
-				       list);
-		sg = sgl->sg;
-
-		for (i = 0; i < sgl->cur; i++) {
-			size_t plen = min_t(size_t, used, sg[i].length);
-
-			if (!sg_page(sg + i))
-				continue;
-
-			sg[i].length -= plen;
-			sg[i].offset += plen;
-
-			used -= plen;
-			ctx->used -= plen;
-
-			if (sg[i].length)
-				return;
-			if (put)
-				put_page(sg_page(sg + i));
-			sg_assign_page(sg + i, NULL);
-		}
-
-		list_del(&sgl->list);
-		sock_kfree_s(sk, sgl,
-			     sizeof(*sgl) + sizeof(sgl->sg[0]) *
-					    (MAX_SGL_ENTS + 1));
-	}
-
-	if (!ctx->used)
-		ctx->merge = 0;
-}
-
-static void skcipher_free_sgl(struct sock *sk)
-{
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-
-	skcipher_pull_sgl(sk, ctx->used, 1);
-}
-
-static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags)
-{
-	DEFINE_WAIT_FUNC(wait, woken_wake_function);
-	int err = -ERESTARTSYS;
-	long timeout;
-
-	if (flags & MSG_DONTWAIT)
-		return -EAGAIN;
-
-	sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
-
-	add_wait_queue(sk_sleep(sk), &wait);
-	for (;;) {
-		if (signal_pending(current))
-			break;
-		timeout = MAX_SCHEDULE_TIMEOUT;
-		if (sk_wait_event(sk, &timeout, skcipher_writable(sk), &wait)) {
-			err = 0;
-			break;
-		}
-	}
-	remove_wait_queue(sk_sleep(sk), &wait);
-
-	return err;
-}
-
-static void skcipher_wmem_wakeup(struct sock *sk)
-{
-	struct socket_wq *wq;
-
-	if (!skcipher_writable(sk))
-		return;
-
-	rcu_read_lock();
-	wq = rcu_dereference(sk->sk_wq);
-	if (skwq_has_sleeper(wq))
-		wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
-							   POLLRDNORM |
-							   POLLRDBAND);
-	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
-	rcu_read_unlock();
-}
-
-static int skcipher_wait_for_data(struct sock *sk, unsigned flags)
-{
-	DEFINE_WAIT_FUNC(wait, woken_wake_function);
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-	long timeout;
-	int err = -ERESTARTSYS;
-
-	if (flags & MSG_DONTWAIT) {
-		return -EAGAIN;
-	}
-
-	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
-
-	add_wait_queue(sk_sleep(sk), &wait);
-	for (;;) {
-		if (signal_pending(current))
-			break;
-		timeout = MAX_SCHEDULE_TIMEOUT;
-		if (sk_wait_event(sk, &timeout, ctx->used, &wait)) {
-			err = 0;
-			break;
-		}
-	}
-	remove_wait_queue(sk_sleep(sk), &wait);
-
-	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
-
-	return err;
-}
-
-static void skcipher_data_wakeup(struct sock *sk)
-{
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-	struct socket_wq *wq;
-
-	if (!ctx->used)
-		return;
-
-	rcu_read_lock();
-	wq = rcu_dereference(sk->sk_wq);
-	if (skwq_has_sleeper(wq))
-		wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
-							   POLLRDNORM |
-							   POLLRDBAND);
-	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
-	rcu_read_unlock();
-}
-
 static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
 			    size_t size)
 {
@@ -298,445 +50,143 @@ static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
 	struct alg_sock *ask = alg_sk(sk);
 	struct sock *psk = ask->parent;
 	struct alg_sock *pask = alg_sk(psk);
-	struct skcipher_ctx *ctx = ask->private;
 	struct skcipher_tfm *skc = pask->private;
 	struct crypto_skcipher *tfm = skc->skcipher;
 	unsigned ivsize = crypto_skcipher_ivsize(tfm);
-	struct skcipher_sg_list *sgl;
-	struct af_alg_control con = {};
-	long copied = 0;
-	bool enc = 0;
-	bool init = 0;
-	int err;
-	int i;
-
-	if (msg->msg_controllen) {
-		err = af_alg_cmsg_send(msg, &con);
-		if (err)
-			return err;
-
-		init = 1;
-		switch (con.op) {
-		case ALG_OP_ENCRYPT:
-			enc = 1;
-			break;
-		case ALG_OP_DECRYPT:
-			enc = 0;
-			break;
-		default:
-			return -EINVAL;
-		}
-
-		if (con.iv && con.iv->ivlen != ivsize)
-			return -EINVAL;
-	}
-
-	err = -EINVAL;
-
-	lock_sock(sk);
-	if (!ctx->more && ctx->used)
-		goto unlock;
-
-	if (init) {
-		ctx->enc = enc;
-		if (con.iv)
-			memcpy(ctx->iv, con.iv->iv, ivsize);
-	}
-
-	while (size) {
-		struct scatterlist *sg;
-		unsigned long len = size;
-		size_t plen;
-
-		if (ctx->merge) {
-			sgl = list_entry(ctx->tsgl.prev,
-					 struct skcipher_sg_list, list);
-			sg = sgl->sg + sgl->cur - 1;
-			len = min_t(unsigned long, len,
-				    PAGE_SIZE - sg->offset - sg->length);
-
-			err = memcpy_from_msg(page_address(sg_page(sg)) +
-					      sg->offset + sg->length,
-					      msg, len);
-			if (err)
-				goto unlock;
-
-			sg->length += len;
-			ctx->merge = (sg->offset + sg->length) &
-				     (PAGE_SIZE - 1);
-
-			ctx->used += len;
-			copied += len;
-			size -= len;
-			continue;
-		}
 
-		if (!skcipher_writable(sk)) {
-			err = skcipher_wait_for_wmem(sk, msg->msg_flags);
-			if (err)
-				goto unlock;
-		}
-
-		len = min_t(unsigned long, len, skcipher_sndbuf(sk));
-
-		err = skcipher_alloc_sgl(sk);
-		if (err)
-			goto unlock;
-
-		sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
-		sg = sgl->sg;
-		if (sgl->cur)
-			sg_unmark_end(sg + sgl->cur - 1);
-		do {
-			i = sgl->cur;
-			plen = min_t(size_t, len, PAGE_SIZE);
-
-			sg_assign_page(sg + i, alloc_page(GFP_KERNEL));
-			err = -ENOMEM;
-			if (!sg_page(sg + i))
-				goto unlock;
-
-			err = memcpy_from_msg(page_address(sg_page(sg + i)),
-					      msg, plen);
-			if (err) {
-				__free_page(sg_page(sg + i));
-				sg_assign_page(sg + i, NULL);
-				goto unlock;
-			}
-
-			sg[i].length = plen;
-			len -= plen;
-			ctx->used += plen;
-			copied += plen;
-			size -= plen;
-			sgl->cur++;
-		} while (len && sgl->cur < MAX_SGL_ENTS);
-
-		if (!size)
-			sg_mark_end(sg + sgl->cur - 1);
-
-		ctx->merge = plen & (PAGE_SIZE - 1);
-	}
-
-	err = 0;
-
-	ctx->more = msg->msg_flags & MSG_MORE;
-
-unlock:
-	skcipher_data_wakeup(sk);
-	release_sock(sk);
-
-	return copied ?: err;
+	return af_alg_sendmsg(sock, msg, size, ivsize);
 }
 
-static ssize_t skcipher_sendpage(struct socket *sock, struct page *page,
-				 int offset, size_t size, int flags)
-{
-	struct sock *sk = sock->sk;
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-	struct skcipher_sg_list *sgl;
-	int err = -EINVAL;
-
-	if (flags & MSG_SENDPAGE_NOTLAST)
-		flags |= MSG_MORE;
-
-	lock_sock(sk);
-	if (!ctx->more && ctx->used)
-		goto unlock;
-
-	if (!size)
-		goto done;
-
-	if (!skcipher_writable(sk)) {
-		err = skcipher_wait_for_wmem(sk, flags);
-		if (err)
-			goto unlock;
-	}
-
-	err = skcipher_alloc_sgl(sk);
-	if (err)
-		goto unlock;
-
-	ctx->merge = 0;
-	sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list);
-
-	if (sgl->cur)
-		sg_unmark_end(sgl->sg + sgl->cur - 1);
-
-	sg_mark_end(sgl->sg + sgl->cur);
-	get_page(page);
-	sg_set_page(sgl->sg + sgl->cur, page, size, offset);
-	sgl->cur++;
-	ctx->used += size;
-
-done:
-	ctx->more = flags & MSG_MORE;
-
-unlock:
-	skcipher_data_wakeup(sk);
-	release_sock(sk);
-
-	return err ?: size;
-}
-
-static int skcipher_all_sg_nents(struct skcipher_ctx *ctx)
-{
-	struct skcipher_sg_list *sgl;
-	struct scatterlist *sg;
-	int nents = 0;
-
-	list_for_each_entry(sgl, &ctx->tsgl, list) {
-		sg = sgl->sg;
-
-		while (!sg->length)
-			sg++;
-
-		nents += sg_nents(sg);
-	}
-	return nents;
-}
-
-static int skcipher_recvmsg_async(struct socket *sock, struct msghdr *msg,
-				  int flags)
+static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
+			     size_t ignored, int flags)
 {
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
 	struct sock *psk = ask->parent;
 	struct alg_sock *pask = alg_sk(psk);
-	struct skcipher_ctx *ctx = ask->private;
+	struct af_alg_ctx *ctx = ask->private;
 	struct skcipher_tfm *skc = pask->private;
 	struct crypto_skcipher *tfm = skc->skcipher;
-	struct skcipher_sg_list *sgl;
-	struct scatterlist *sg;
-	struct skcipher_async_req *sreq;
-	struct skcipher_request *req;
-	struct skcipher_async_rsgl *last_rsgl = NULL;
-	unsigned int txbufs = 0, len = 0, tx_nents;
-	unsigned int reqsize = crypto_skcipher_reqsize(tfm);
-	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
-	int err = -ENOMEM;
-	bool mark = false;
-	char *iv;
-
-	sreq = kzalloc(sizeof(*sreq) + reqsize + ivsize, GFP_KERNEL);
-	if (unlikely(!sreq))
-		goto out;
-
-	req = &sreq->req;
-	iv = (char *)(req + 1) + reqsize;
-	sreq->iocb = msg->msg_iocb;
-	INIT_LIST_HEAD(&sreq->list);
-	sreq->inflight = &ctx->inflight;
+	unsigned int bs = crypto_skcipher_blocksize(tfm);
+	struct af_alg_async_req *areq;
+	int err = 0;
+	size_t len = 0;
 
-	lock_sock(sk);
-	tx_nents = skcipher_all_sg_nents(ctx);
-	sreq->tsg = kcalloc(tx_nents, sizeof(*sg), GFP_KERNEL);
-	if (unlikely(!sreq->tsg))
-		goto unlock;
-	sg_init_table(sreq->tsg, tx_nents);
-	memcpy(iv, ctx->iv, ivsize);
-	skcipher_request_set_tfm(req, tfm);
-	skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
-				      skcipher_async_cb, sreq);
-
-	while (iov_iter_count(&msg->msg_iter)) {
-		struct skcipher_async_rsgl *rsgl;
-		int used;
-
-		if (!ctx->used) {
-			err = skcipher_wait_for_data(sk, flags);
-			if (err)
-				goto free;
-		}
-		sgl = list_first_entry(&ctx->tsgl,
-				       struct skcipher_sg_list, list);
-		sg = sgl->sg;
-
-		while (!sg->length)
-			sg++;
-
-		used = min_t(unsigned long, ctx->used,
-			     iov_iter_count(&msg->msg_iter));
-		used = min_t(unsigned long, used, sg->length);
-
-		if (txbufs == tx_nents) {
-			struct scatterlist *tmp;
-			int x;
-			/* Ran out of tx slots in async request
-			 * need to expand */
-			tmp = kcalloc(tx_nents * 2, sizeof(*tmp),
-				      GFP_KERNEL);
-			if (!tmp) {
-				err = -ENOMEM;
-				goto free;
-			}
-
-			sg_init_table(tmp, tx_nents * 2);
-			for (x = 0; x < tx_nents; x++)
-				sg_set_page(&tmp[x], sg_page(&sreq->tsg[x]),
-					    sreq->tsg[x].length,
-					    sreq->tsg[x].offset);
-			kfree(sreq->tsg);
-			sreq->tsg = tmp;
-			tx_nents *= 2;
-			mark = true;
-		}
-		/* Need to take over the tx sgl from ctx
-		 * to the asynch req - these sgls will be freed later */
-		sg_set_page(sreq->tsg + txbufs++, sg_page(sg), sg->length,
-			    sg->offset);
-
-		if (list_empty(&sreq->list)) {
-			rsgl = &sreq->first_sgl;
-			list_add_tail(&rsgl->list, &sreq->list);
-		} else {
-			rsgl = kmalloc(sizeof(*rsgl), GFP_KERNEL);
-			if (!rsgl) {
-				err = -ENOMEM;
-				goto free;
-			}
-			list_add_tail(&rsgl->list, &sreq->list);
-		}
+	/* Allocate cipher request for current operation. */
+	areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
+				     crypto_skcipher_reqsize(tfm));
+	if (IS_ERR(areq))
+		return PTR_ERR(areq);
 
-		used = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, used);
-		err = used;
-		if (used < 0)
-			goto free;
-		if (last_rsgl)
-			af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
-
-		last_rsgl = rsgl;
-		len += used;
-		skcipher_pull_sgl(sk, used, 0);
-		iov_iter_advance(&msg->msg_iter, used);
+	/* convert iovecs of output buffers into RX SGL */
+	err = af_alg_get_rsgl(sk, msg, flags, areq, -1, &len);
+	if (err)
+		goto free;
+
+	/* Process only as much RX buffers for which we have TX data */
+	if (len > ctx->used)
+		len = ctx->used;
+
+	/*
+	 * If more buffers are to be expected to be processed, process only
+	 * full block size buffers.
+	 */
+	if (ctx->more || len < ctx->used)
+		len -= len % bs;
+
+	/*
+	 * Create a per request TX SGL for this request which tracks the
+	 * SG entries from the global TX SGL.
+	 */
+	areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0);
+	if (!areq->tsgl_entries)
+		areq->tsgl_entries = 1;
+	areq->tsgl = sock_kmalloc(sk, sizeof(*areq->tsgl) * areq->tsgl_entries,
+				  GFP_KERNEL);
+	if (!areq->tsgl) {
+		err = -ENOMEM;
+		goto free;
+	}
+	sg_init_table(areq->tsgl, areq->tsgl_entries);
+	af_alg_pull_tsgl(sk, len, areq->tsgl, 0);
+
+	/* Initialize the crypto operation */
+	skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm);
+	skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl,
+				   areq->first_rsgl.sgl.sg, len, ctx->iv);
+
+	if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
+		/* AIO operation */
+		areq->iocb = msg->msg_iocb;
+		skcipher_request_set_callback(&areq->cra_u.skcipher_req,
+					      CRYPTO_TFM_REQ_MAY_SLEEP,
+					      af_alg_async_cb, areq);
+		err = ctx->enc ?
+			crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
+			crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
+	} else {
+		/* Synchronous operation */
+		skcipher_request_set_callback(&areq->cra_u.skcipher_req,
+					      CRYPTO_TFM_REQ_MAY_SLEEP |
+					      CRYPTO_TFM_REQ_MAY_BACKLOG,
+					      af_alg_complete,
+					      &ctx->completion);
+		err = af_alg_wait_for_completion(ctx->enc ?
+			crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
+			crypto_skcipher_decrypt(&areq->cra_u.skcipher_req),
+						 &ctx->completion);
 	}
 
-	if (mark)
-		sg_mark_end(sreq->tsg + txbufs - 1);
-
-	skcipher_request_set_crypt(req, sreq->tsg, sreq->first_sgl.sgl.sg,
-				   len, iv);
-	err = ctx->enc ? crypto_skcipher_encrypt(req) :
-			 crypto_skcipher_decrypt(req);
+	/* AIO operation in progress */
 	if (err == -EINPROGRESS) {
-		atomic_inc(&ctx->inflight);
-		err = -EIOCBQUEUED;
-		sreq = NULL;
-		goto unlock;
+		sock_hold(sk);
+
+		/* Remember output size that will be generated. */
+		areq->outlen = len;
+
+		return -EIOCBQUEUED;
 	}
+
 free:
-	skcipher_free_async_sgls(sreq);
-unlock:
-	skcipher_wmem_wakeup(sk);
-	release_sock(sk);
-	kzfree(sreq);
-out:
-	return err;
+	af_alg_free_areq_sgls(areq);
+	sock_kfree_s(sk, areq, areq->areqlen);
+
+	return err ? err : len;
 }
 
-static int skcipher_recvmsg_sync(struct socket *sock, struct msghdr *msg,
-				 int flags)
+static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
+			    size_t ignored, int flags)
 {
 	struct sock *sk = sock->sk;
-	struct alg_sock *ask = alg_sk(sk);
-	struct sock *psk = ask->parent;
-	struct alg_sock *pask = alg_sk(psk);
-	struct skcipher_ctx *ctx = ask->private;
-	struct skcipher_tfm *skc = pask->private;
-	struct crypto_skcipher *tfm = skc->skcipher;
-	unsigned bs = crypto_skcipher_blocksize(tfm);
-	struct skcipher_sg_list *sgl;
-	struct scatterlist *sg;
-	int err = -EAGAIN;
-	int used;
-	long copied = 0;
+	int ret = 0;
 
 	lock_sock(sk);
 	while (msg_data_left(msg)) {
-		if (!ctx->used) {
-			err = skcipher_wait_for_data(sk, flags);
-			if (err)
-				goto unlock;
+		int err = _skcipher_recvmsg(sock, msg, ignored, flags);
+
+		/*
+		 * This error covers -EIOCBQUEUED which implies that we can
+		 * only handle one AIO request. If the caller wants to have
+		 * multiple AIO requests in parallel, he must make multiple
+		 * separate AIO calls.
+		 *
+		 * Also return the error if no data has been processed so far.
+		 */
+		if (err <= 0) {
+			if (err == -EIOCBQUEUED || !ret)
+				ret = err;
+			goto out;
 		}
 
-		used = min_t(unsigned long, ctx->used, msg_data_left(msg));
-
-		used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
-		err = used;
-		if (err < 0)
-			goto unlock;
-
-		if (ctx->more || used < ctx->used)
-			used -= used % bs;
-
-		err = -EINVAL;
-		if (!used)
-			goto free;
-
-		sgl = list_first_entry(&ctx->tsgl,
-				       struct skcipher_sg_list, list);
-		sg = sgl->sg;
-
-		while (!sg->length)
-			sg++;
-
-		skcipher_request_set_crypt(&ctx->req, sg, ctx->rsgl.sg, used,
-					   ctx->iv);
-
-		err = af_alg_wait_for_completion(
-				ctx->enc ?
-					crypto_skcipher_encrypt(&ctx->req) :
-					crypto_skcipher_decrypt(&ctx->req),
-				&ctx->completion);
-
-free:
-		af_alg_free_sg(&ctx->rsgl);
-
-		if (err)
-			goto unlock;
-
-		copied += used;
-		skcipher_pull_sgl(sk, used, 1);
-		iov_iter_advance(&msg->msg_iter, used);
+		ret += err;
 	}
 
-	err = 0;
-
-unlock:
-	skcipher_wmem_wakeup(sk);
+out:
+	af_alg_wmem_wakeup(sk);
 	release_sock(sk);
-
-	return copied ?: err;
-}
-
-static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
-			    size_t ignored, int flags)
-{
-	return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
-		skcipher_recvmsg_async(sock, msg, flags) :
-		skcipher_recvmsg_sync(sock, msg, flags);
+	return ret;
 }
 
-static unsigned int skcipher_poll(struct file *file, struct socket *sock,
-				  poll_table *wait)
-{
-	struct sock *sk = sock->sk;
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-	unsigned int mask;
-
-	sock_poll_wait(file, sk_sleep(sk), wait);
-	mask = 0;
-
-	if (ctx->used)
-		mask |= POLLIN | POLLRDNORM;
-
-	if (skcipher_writable(sk))
-		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
-
-	return mask;
-}
 
 static struct proto_ops algif_skcipher_ops = {
 	.family		=	PF_ALG,
@@ -755,9 +205,9 @@ static struct proto_ops algif_skcipher_ops = {
 
 	.release	=	af_alg_release,
 	.sendmsg	=	skcipher_sendmsg,
-	.sendpage	=	skcipher_sendpage,
+	.sendpage	=	af_alg_sendpage,
 	.recvmsg	=	skcipher_recvmsg,
-	.poll		=	skcipher_poll,
+	.poll		=	af_alg_poll,
 };
 
 static int skcipher_check_key(struct socket *sock)
@@ -819,7 +269,7 @@ static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
 	if (err)
 		return err;
 
-	return skcipher_sendpage(sock, page, offset, size, flags);
+	return af_alg_sendpage(sock, page, offset, size, flags);
 }
 
 static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
@@ -853,7 +303,7 @@ static struct proto_ops algif_skcipher_ops_nokey = {
 	.sendmsg	=	skcipher_sendmsg_nokey,
 	.sendpage	=	skcipher_sendpage_nokey,
 	.recvmsg	=	skcipher_recvmsg_nokey,
-	.poll		=	skcipher_poll,
+	.poll		=	af_alg_poll,
 };
 
 static void *skcipher_bind(const char *name, u32 type, u32 mask)
@@ -895,26 +345,16 @@ static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
 	return err;
 }
 
-static void skcipher_wait(struct sock *sk)
-{
-	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-	int ctr = 0;
-
-	while (atomic_read(&ctx->inflight) && ctr++ < 100)
-		msleep(100);
-}
-
 static void skcipher_sock_destruct(struct sock *sk)
 {
 	struct alg_sock *ask = alg_sk(sk);
-	struct skcipher_ctx *ctx = ask->private;
-	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(&ctx->req);
-
-	if (atomic_read(&ctx->inflight))
-		skcipher_wait(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct sock *psk = ask->parent;
+	struct alg_sock *pask = alg_sk(psk);
+	struct skcipher_tfm *skc = pask->private;
+	struct crypto_skcipher *tfm = skc->skcipher;
 
-	skcipher_free_sgl(sk);
+	af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
 	sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
 	sock_kfree_s(sk, ctx, ctx->len);
 	af_alg_release_parent(sk);
@@ -922,11 +362,11 @@ static void skcipher_sock_destruct(struct sock *sk)
 
 static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
 {
-	struct skcipher_ctx *ctx;
+	struct af_alg_ctx *ctx;
 	struct alg_sock *ask = alg_sk(sk);
 	struct skcipher_tfm *tfm = private;
 	struct crypto_skcipher *skcipher = tfm->skcipher;
-	unsigned int len = sizeof(*ctx) + crypto_skcipher_reqsize(skcipher);
+	unsigned int len = sizeof(*ctx);
 
 	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
 	if (!ctx)
@@ -941,22 +381,17 @@ static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
 
 	memset(ctx->iv, 0, crypto_skcipher_ivsize(skcipher));
 
-	INIT_LIST_HEAD(&ctx->tsgl);
+	INIT_LIST_HEAD(&ctx->tsgl_list);
 	ctx->len = len;
 	ctx->used = 0;
+	ctx->rcvused = 0;
 	ctx->more = 0;
 	ctx->merge = 0;
 	ctx->enc = 0;
-	atomic_set(&ctx->inflight, 0);
 	af_alg_init_completion(&ctx->completion);
 
 	ask->private = ctx;
 
-	skcipher_request_set_tfm(&ctx->req, skcipher);
-	skcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_SLEEP |
-						 CRYPTO_TFM_REQ_MAY_BACKLOG,
-				      af_alg_complete, &ctx->completion);
-
 	sk->sk_destruct = skcipher_sock_destruct;
 
 	return 0;