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crypto: af_alg: Support MSG_SPLICE_PAGES

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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 <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: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
David Howells 2023-06-06 14:08:54 +01:00 committed by Paolo Abeni
parent 73d7409cfd
commit bf63e250c4
3 changed files with 37 additions and 17 deletions
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24
crypto/af_alg.c
View File

@ -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;

22
crypto/algif_aead.c
View File

@ -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;

8
crypto/algif_skcipher.c
View File

@ -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