From bf63e250c4b1f21696599e0ab7117f4429dcbdc0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 6 Jun 2023 14:08:54 +0100 Subject: [PATCH] crypto: af_alg: Support MSG_SPLICE_PAGES Make AF_ALG sendmsg() support MSG_SPLICE_PAGES. This causes pages to be spliced from the source iterator. This allows ->sendpage() to be replaced by something that can handle multiple multipage folios in a single transaction. Signed-off-by: David Howells cc: Herbert Xu cc: "David S. Miller" cc: Eric Dumazet cc: Jakub Kicinski cc: Paolo Abeni cc: Jens Axboe cc: Matthew Wilcox cc: linux-crypto@vger.kernel.org cc: netdev@vger.kernel.org Acked-by: Herbert Xu Signed-off-by: Paolo Abeni --- crypto/af_alg.c | 24 ++++++++++++++++++++++-- crypto/algif_aead.c | 22 +++++++++++----------- crypto/algif_skcipher.c | 8 ++++---- 3 files changed, 37 insertions(+), 17 deletions(-) diff --git a/crypto/af_alg.c b/crypto/af_alg.c index fd56ccff6fed..9c12530d604a 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -985,7 +985,7 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, while (size) { struct scatterlist *sg; size_t len = size; - size_t plen; + ssize_t plen; /* use the existing memory in an allocated page */ if (ctx->merge) { @@ -1030,7 +1030,27 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, if (sgl->cur) sg_unmark_end(sg + sgl->cur - 1); - if (1 /* TODO check MSG_SPLICE_PAGES */) { + if (msg->msg_flags & MSG_SPLICE_PAGES) { + struct sg_table sgtable = { + .sgl = sg, + .nents = sgl->cur, + .orig_nents = sgl->cur, + }; + + plen = extract_iter_to_sg(&msg->msg_iter, len, &sgtable, + MAX_SGL_ENTS, 0); + if (plen < 0) { + err = plen; + goto unlock; + } + + for (; sgl->cur < sgtable.nents; sgl->cur++) + get_page(sg_page(&sg[sgl->cur])); + len -= plen; + ctx->used += plen; + copied += plen; + size -= plen; + } else { do { struct page *pg; unsigned int i = sgl->cur; diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c index 829878025dba..35bfa283748d 100644 --- a/crypto/algif_aead.c +++ b/crypto/algif_aead.c @@ -9,8 +9,8 @@ * 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 + * filled by user space with the data submitted via sendpage. 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. * @@ -113,19 +113,19 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg, } /* - * Data length provided by caller via sendmsg/sendpage that has not - * yet been processed. + * Data length provided by caller via sendmsg that has not yet been + * processed. */ used = ctx->used; /* - * Make sure sufficient data is present -- note, the same check is - * also present in sendmsg/sendpage. The checks in sendpage/sendmsg - * shall provide an information to the data sender that something is - * wrong, but they are irrelevant to maintain the kernel integrity. - * We need this check here too in case user space decides to not honor - * the error message in sendmsg/sendpage and still call recvmsg. This - * check here protects the kernel integrity. + * Make sure sufficient data is present -- note, the same check is also + * present in sendmsg. The checks in sendmsg shall provide an + * information to the data sender that something is wrong, but they are + * irrelevant to maintain the kernel integrity. We need this check + * here too in case user space decides to not honor the error message + * in sendmsg and still call recvmsg. This check here protects the + * kernel integrity. */ if (!aead_sufficient_data(sk)) return -EINVAL; diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index a251cd6bd5b9..b1f321b9f846 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -9,10 +9,10 @@ * 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. + * filled by user space with the data submitted via 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