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crypto: af_alg: Use extract_iter_to_sg() to create scatterlists
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Use extract_iter_to_sg() to decant the destination iterator into a
scatterlist in af_alg_get_rsgl().  af_alg_make_sg() can then be removed.

Signed-off-by: David Howells <[email protected]>
cc: Herbert Xu <[email protected]>
cc: "David S. Miller" <[email protected]>
cc: Eric Dumazet <[email protected]>
cc: Jakub Kicinski <[email protected]>
cc: Paolo Abeni <[email protected]>
cc: Jens Axboe <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: [email protected]
cc: [email protected]
Acked-by: Herbert Xu <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
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@dhowells
dhowells authored and Paolo Abeni committed Jun 8, 2023
1 parent f9e7a5f commit c1abe6f
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Showing 5 changed files with 40 additions and 59 deletions.
57 changes: 15 additions & 42 deletions crypto/af_alg.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -531,54 +531,20 @@ static const struct net_proto_family alg_family = {
.owner = THIS_MODULE,
};

int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
{
struct page **pages = sgl->pages;
size_t off;
ssize_t n;
int npages, i;

n = iov_iter_extract_pages(iter, &pages, len, ALG_MAX_PAGES, 0, &off);
if (n < 0)
return n;

sgl->need_unpin = iov_iter_extract_will_pin(iter);

npages = DIV_ROUND_UP(off + n, PAGE_SIZE);
if (WARN_ON(npages == 0))
return -EINVAL;
/* Add one extra for linking */
sg_init_table(sgl->sg, npages + 1);

for (i = 0, len = n; i < npages; i++) {
int plen = min_t(int, len, PAGE_SIZE - off);

sg_set_page(sgl->sg + i, sgl->pages[i], plen, off);

off = 0;
len -= plen;
}
sg_mark_end(sgl->sg + npages - 1);
sgl->npages = npages;

return n;
}
EXPORT_SYMBOL_GPL(af_alg_make_sg);

static void af_alg_link_sg(struct af_alg_sgl *sgl_prev,
struct af_alg_sgl *sgl_new)
{
sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
sg_chain(sgl_prev->sg, sgl_prev->npages + 1, sgl_new->sg);
sg_unmark_end(sgl_prev->sgt.sgl + sgl_prev->sgt.nents - 1);
sg_chain(sgl_prev->sgt.sgl, sgl_prev->sgt.nents + 1, sgl_new->sgt.sgl);
}

void af_alg_free_sg(struct af_alg_sgl *sgl)
{
int i;

if (sgl->need_unpin)
for (i = 0; i < sgl->npages; i++)
unpin_user_page(sgl->pages[i]);
for (i = 0; i < sgl->sgt.nents; i++)
unpin_user_page(sg_page(&sgl->sgt.sgl[i]));
}
EXPORT_SYMBOL_GPL(af_alg_free_sg);

Expand Down Expand Up @@ -1292,8 +1258,8 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,

while (maxsize > len && msg_data_left(msg)) {
struct af_alg_rsgl *rsgl;
ssize_t err;
size_t seglen;
int err;

/* limit the amount of readable buffers */
if (!af_alg_readable(sk))
Expand All @@ -1310,16 +1276,23 @@ int af_alg_get_rsgl(struct sock *sk, struct msghdr *msg, int flags,
return -ENOMEM;
}

rsgl->sgl.npages = 0;
rsgl->sgl.sgt.sgl = rsgl->sgl.sgl;
rsgl->sgl.sgt.nents = 0;
rsgl->sgl.sgt.orig_nents = 0;
list_add_tail(&rsgl->list, &areq->rsgl_list);

/* make one iovec available as scatterlist */
err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
sg_init_table(rsgl->sgl.sgt.sgl, ALG_MAX_PAGES);
err = extract_iter_to_sg(&msg->msg_iter, seglen, &rsgl->sgl.sgt,
ALG_MAX_PAGES, 0);
if (err < 0) {
rsgl->sg_num_bytes = 0;
return err;
}

sg_mark_end(rsgl->sgl.sgt.sgl + rsgl->sgl.sgt.nents - 1);
rsgl->sgl.need_unpin =
iov_iter_extract_will_pin(&msg->msg_iter);

/* chain the new scatterlist with previous one */
if (areq->last_rsgl)
af_alg_link_sg(&areq->last_rsgl->sgl, &rsgl->sgl);
Expand Down
16 changes: 9 additions & 7 deletions crypto/algif_aead.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -210,7 +210,7 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
*/

/* Use the RX SGL as source (and destination) for crypto op. */
rsgl_src = areq->first_rsgl.sgl.sg;
rsgl_src = areq->first_rsgl.sgl.sgt.sgl;

if (ctx->enc) {
/*
Expand All @@ -224,7 +224,8 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
* RX SGL: AAD || PT || Tag
*/
err = crypto_aead_copy_sgl(null_tfm, tsgl_src,
areq->first_rsgl.sgl.sg, processed);
areq->first_rsgl.sgl.sgt.sgl,
processed);
if (err)
goto free;
af_alg_pull_tsgl(sk, processed, NULL, 0);
Expand All @@ -242,7 +243,8 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,

/* Copy AAD || CT to RX SGL buffer for in-place operation. */
err = crypto_aead_copy_sgl(null_tfm, tsgl_src,
areq->first_rsgl.sgl.sg, outlen);
areq->first_rsgl.sgl.sgt.sgl,
outlen);
if (err)
goto free;

Expand All @@ -267,18 +269,18 @@ static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
if (usedpages) {
/* RX SGL present */
struct af_alg_sgl *sgl_prev = &areq->last_rsgl->sgl;
struct scatterlist *sg = sgl_prev->sgt.sgl;

sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
sg_chain(sgl_prev->sg, sgl_prev->npages + 1,
areq->tsgl);
sg_unmark_end(sg + sgl_prev->sgt.nents - 1);
sg_chain(sg, sgl_prev->sgt.nents + 1, areq->tsgl);
} else
/* no RX SGL present (e.g. authentication only) */
rsgl_src = areq->tsgl;
}

/* Initialize the crypto operation */
aead_request_set_crypt(&areq->cra_u.aead_req, rsgl_src,
areq->first_rsgl.sgl.sg, used, ctx->iv);
areq->first_rsgl.sgl.sgt.sgl, used, ctx->iv);
aead_request_set_ad(&areq->cra_u.aead_req, ctx->aead_assoclen);
aead_request_set_tfm(&areq->cra_u.aead_req, tfm);

Expand Down
18 changes: 13 additions & 5 deletions crypto/algif_hash.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -91,13 +91,21 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
if (len > limit)
len = limit;

len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len);
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;
}
sg_mark_end(ctx->sgl.sgt.sgl + ctx->sgl.sgt.nents);

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

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

err = crypto_wait_req(crypto_ahash_update(&ctx->req),
&ctx->wait);
Expand Down Expand Up @@ -141,8 +149,8 @@ static ssize_t hash_sendpage(struct socket *sock, struct page *page,
flags |= MSG_MORE;

lock_sock(sk);
sg_init_table(ctx->sgl.sg, 1);
sg_set_page(ctx->sgl.sg, page, size, offset);
sg_init_table(ctx->sgl.sgl, 1);
sg_set_page(ctx->sgl.sgl, page, size, offset);

if (!(flags & MSG_MORE)) {
err = hash_alloc_result(sk, ctx);
Expand All @@ -151,7 +159,7 @@ static ssize_t hash_sendpage(struct socket *sock, struct page *page,
} else if (!ctx->more)
hash_free_result(sk, ctx);

ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
ahash_request_set_crypt(&ctx->req, ctx->sgl.sgl, ctx->result, size);

if (!(flags & MSG_MORE)) {
if (ctx->more)
Expand Down
2 changes: 1 addition & 1 deletion crypto/algif_skcipher.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -105,7 +105,7 @@ static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
/* 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);
areq->first_rsgl.sgl.sgt.sgl, len, ctx->iv);

if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
/* AIO operation */
Expand Down
6 changes: 2 additions & 4 deletions include/crypto/if_alg.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,9 +56,8 @@ struct af_alg_type {
};

struct af_alg_sgl {
struct scatterlist sg[ALG_MAX_PAGES + 1];
struct page *pages[ALG_MAX_PAGES];
unsigned int npages;
struct sg_table sgt;
struct scatterlist sgl[ALG_MAX_PAGES + 1];
bool need_unpin;
};

Expand Down Expand Up @@ -164,7 +163,6 @@ int af_alg_release(struct socket *sock);
void af_alg_release_parent(struct sock *sk);
int af_alg_accept(struct sock *sk, struct socket *newsock, bool kern);

int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len);
void af_alg_free_sg(struct af_alg_sgl *sgl);

static inline struct alg_sock *alg_sk(struct sock *sk)
Expand Down

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