crypto: switch af_alg_make_sg() to iov_iter

With that, all ->sendmsg() instances are converted to iov_iter primitives
and are agnostic wrt the kind of iov_iter they are working with.
So's the last remaining ->recvmsg() instance that wasn't kind-agnostic yet.
All ->sendmsg() and ->recvmsg() advance ->msg_iter by the amount actually
copied and none of them modifies the underlying iovec, etc.

Cc: linux-crypto@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 17 insertions, 28 deletions

diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 01f56eb7816e..01da360bdb55 100644
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -41,8 +41,6 @@ static int hash_sendmsg(struct kiocb *unused, struct socket *sock,
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
 	struct hash_ctx *ctx = ask->private;
-	unsigned long iovlen;
-	const struct iovec *iov;
 	long copied = 0;
 	int err;
 
@@ -58,37 +56,28 @@ static int hash_sendmsg(struct kiocb *unused, struct socket *sock,
 
 	ctx->more = 0;
 
-	for (iov = msg->msg_iter.iov, iovlen = msg->msg_iter.nr_segs; iovlen > 0;
-	     iovlen--, iov++) {
-		unsigned long seglen = iov->iov_len;
-		char __user *from = iov->iov_base;
+	while (iov_iter_count(&msg->msg_iter)) {
+		int len = iov_iter_count(&msg->msg_iter);
 
-		while (seglen) {
-			int len = min_t(unsigned long, seglen, limit);
-			int newlen;
+		if (len > limit)
+			len = limit;
 
-			newlen = af_alg_make_sg(&ctx->sgl, from, len, 0);
-			if (newlen < 0) {
-				err = copied ? 0 : newlen;
-				goto unlock;
-			}
-
-			ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL,
-						newlen);
-
-			err = af_alg_wait_for_completion(
-				crypto_ahash_update(&ctx->req),
-				&ctx->completion);
+		len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len);
+		if (len < 0) {
+			err = copied ? 0 : len;
+			goto unlock;
+		}
 
-			af_alg_free_sg(&ctx->sgl);
+		ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len);
 
-			if (err)
-				goto unlock;
+		err = af_alg_wait_for_completion(crypto_ahash_update(&ctx->req),
+						 &ctx->completion);
+		af_alg_free_sg(&ctx->sgl);
+		if (err)
+			goto unlock;
 
-			seglen -= newlen;
-			from += newlen;
-			copied += newlen;
-		}
+		copied += len;
+		iov_iter_advance(&msg->msg_iter, len);
 	}
 
 	err = 0;