Commit c662b043 authored by David Howells's avatar David Howells Committed by Paolo Abeni
Browse files

crypto: af_alg/hash: Support MSG_SPLICE_PAGES 



Make AF_ALG sendmsg() support MSG_SPLICE_PAGES in the hashing code.  This
causes pages to be spliced from the source iterator if possible.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Herbert Xu <herbert@gondor.apana.org.au>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-crypto@vger.kernel.org
cc: netdev@vger.kernel.org
Acked-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent fb800fa4

crypto/af_alg.c

+8 −3
Original line number Diff line number Diff line
@@ -542,9 +542,14 @@ void af_alg_free_sg(struct af_alg_sgl *sgl) 
{

	int i;



	if (sgl->sgt.sgl) {

		if (sgl->need_unpin)

			for (i = 0; i < sgl->sgt.nents; i++)

				unpin_user_page(sg_page(&sgl->sgt.sgl[i]));

		if (sgl->sgt.sgl != sgl->sgl)

			kvfree(sgl->sgt.sgl);

		sgl->sgt.sgl = NULL;

	}

}

EXPORT_SYMBOL_GPL(af_alg_free_sg);

crypto/algif_hash.c

+62 −38
Original line number Diff line number Diff line
@@ -63,78 +63,102 @@ static void hash_free_result(struct sock *sk, struct hash_ctx *ctx) 
static int hash_sendmsg(struct socket *sock, struct msghdr *msg,

			size_t ignored)

{

	int limit = ALG_MAX_PAGES * PAGE_SIZE;

	struct sock *sk = sock->sk;

	struct alg_sock *ask = alg_sk(sk);

	struct hash_ctx *ctx = ask->private;

	long copied = 0;

	ssize_t copied = 0;

	size_t len, max_pages, npages;

	bool continuing = ctx->more, need_init = false;

	int err;



	if (limit > sk->sk_sndbuf)

		limit = sk->sk_sndbuf;

	max_pages = min_t(size_t, ALG_MAX_PAGES,

			  DIV_ROUND_UP(sk->sk_sndbuf, PAGE_SIZE));



	lock_sock(sk);

	if (!ctx->more) {

	if (!continuing) {

		if ((msg->msg_flags & MSG_MORE))

			hash_free_result(sk, ctx);



		err = crypto_wait_req(crypto_ahash_init(&ctx->req), &ctx->wait);

		if (err)

			goto unlock;

		need_init = true;

	}



	ctx->more = false;



	while (msg_data_left(msg)) {

		int len = msg_data_left(msg);



		if (len > limit)

			len = limit;



		ctx->sgl.sgt.sgl = ctx->sgl.sgl;

		ctx->sgl.sgt.nents = 0;

		ctx->sgl.sgt.orig_nents = 0;



		len = extract_iter_to_sg(&msg->msg_iter, len, &ctx->sgl.sgt,

					 ALG_MAX_PAGES, 0);

		if (len < 0) {

			err = copied ? 0 : len;

			goto unlock;

		err = -EIO;

		npages = iov_iter_npages(&msg->msg_iter, max_pages);

		if (npages == 0)

			goto unlock_free;



		if (npages > ARRAY_SIZE(ctx->sgl.sgl)) {

			err = -ENOMEM;

			ctx->sgl.sgt.sgl =

				kvmalloc(array_size(npages,

						    sizeof(*ctx->sgl.sgt.sgl)),

					 GFP_KERNEL);

			if (!ctx->sgl.sgt.sgl)

				goto unlock_free;

		}

		sg_mark_end(ctx->sgl.sgt.sgl + ctx->sgl.sgt.nents);

		sg_init_table(ctx->sgl.sgl, npages);



		ctx->sgl.need_unpin = iov_iter_extract_will_pin(&msg->msg_iter);



		ahash_request_set_crypt(&ctx->req, ctx->sgl.sgt.sgl, NULL, len);

		err = extract_iter_to_sg(&msg->msg_iter, LONG_MAX,

					 &ctx->sgl.sgt, npages, 0);

		if (err < 0)

			goto unlock_free;

		len = err;

		sg_mark_end(ctx->sgl.sgt.sgl + ctx->sgl.sgt.nents - 1);



		err = crypto_wait_req(crypto_ahash_update(&ctx->req),

				      &ctx->wait);

		af_alg_free_sg(&ctx->sgl);

		if (err) {

			iov_iter_revert(&msg->msg_iter, len);

			goto unlock;

		if (!msg_data_left(msg)) {

			err = hash_alloc_result(sk, ctx);

			if (err)

				goto unlock_free;

		}



		copied += len;

		ahash_request_set_crypt(&ctx->req, ctx->sgl.sgt.sgl,

					ctx->result, len);



		if (!msg_data_left(msg) && !continuing &&

		    !(msg->msg_flags & MSG_MORE)) {

			err = crypto_ahash_digest(&ctx->req);

		} else {

			if (need_init) {

				err = crypto_wait_req(

					crypto_ahash_init(&ctx->req),

					&ctx->wait);

				if (err)

					goto unlock_free;

				need_init = false;

			}



	err = 0;

			if (msg_data_left(msg) || (msg->msg_flags & MSG_MORE))

				err = crypto_ahash_update(&ctx->req);

			else

				err = crypto_ahash_finup(&ctx->req);

			continuing = true;

		}



	ctx->more = msg->msg_flags & MSG_MORE;

	if (!ctx->more) {

		err = hash_alloc_result(sk, ctx);

		err = crypto_wait_req(err, &ctx->wait);

		if (err)

			goto unlock;

			goto unlock_free;



		ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);

		err = crypto_wait_req(crypto_ahash_final(&ctx->req),

				      &ctx->wait);

		copied += len;

		af_alg_free_sg(&ctx->sgl);

	}



	ctx->more = msg->msg_flags & MSG_MORE;

	err = 0;

unlock:

	release_sock(sk);

	return copied ?: err;



	return err ?: copied;

unlock_free:

	af_alg_free_sg(&ctx->sgl);

	goto unlock;

}



static ssize_t hash_sendpage(struct socket *sock, struct page *page,