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>

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 4665b79..eb78fe8 100644 (file)
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -338,49 +338,31 @@ static const struct net_proto_family alg_family = {
        .owner  =       THIS_MODULE,
 };
 
-int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len,
-                  int write)
+int af_alg_make_sg(struct af_alg_sgl *sgl, struct iov_iter *iter, int len)
 {
-       unsigned long from = (unsigned long)addr;
-       unsigned long npages;
-       unsigned off;
-       int err;
-       int i;
-
-       err = -EFAULT;
-       if (!access_ok(write ? VERIFY_READ : VERIFY_WRITE, addr, len))
-               goto out;
-
-       off = from & ~PAGE_MASK;
-       npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-       if (npages > ALG_MAX_PAGES)
-               npages = ALG_MAX_PAGES;
+       size_t off;
+       ssize_t n;
+       int npages, i;
 
-       err = get_user_pages_fast(from, npages, write, sgl->pages);
-       if (err < 0)
-               goto out;
+       n = iov_iter_get_pages(iter, sgl->pages, len, ALG_MAX_PAGES, &off);
+       if (n < 0)
+               return n;
 
-       npages = err;
-       err = -EINVAL;
+       npages = PAGE_ALIGN(off + n);
        if (WARN_ON(npages == 0))
-               goto out;
-
-       err = 0;
+               return -EINVAL;
 
        sg_init_table(sgl->sg, npages);
 
-       for (i = 0; i < npages; i++) {
+       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;
-               err += plen;
        }
-
-out:
-       return err;
+       return n;
 }
 EXPORT_SYMBOL_GPL(af_alg_make_sg);
 

diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 01f56eb..01da360 100644 (file)
--- 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;

diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c
index c12207c..37110fd 100644 (file)
--- a/crypto/algif_skcipher.c
+++ b/crypto/algif_skcipher.c
@@ -426,67 +426,59 @@ static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock,
                &ctx->req));
        struct skcipher_sg_list *sgl;
        struct scatterlist *sg;
-       unsigned long iovlen;
-       const struct iovec *iov;
        int err = -EAGAIN;
        int used;
        long copied = 0;
 
        lock_sock(sk);
-       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 (seglen) {
-                       sgl = list_first_entry(&ctx->tsgl,
-                                              struct skcipher_sg_list, list);
-                       sg = sgl->sg;
-
-                       while (!sg->length)
-                               sg++;
-
-                       if (!ctx->used) {
-                               err = skcipher_wait_for_data(sk, flags);
-                               if (err)
-                                       goto unlock;
-                       }
+       while (iov_iter_count(&msg->msg_iter)) {
+               sgl = list_first_entry(&ctx->tsgl,
+                                      struct skcipher_sg_list, list);
+               sg = sgl->sg;
 
-                       used = min_t(unsigned long, ctx->used, seglen);
+               while (!sg->length)
+                       sg++;
 
-                       used = af_alg_make_sg(&ctx->rsgl, from, used, 1);
-                       err = used;
-                       if (err < 0)
+               used = ctx->used;
+               if (!used) {
+                       err = skcipher_wait_for_data(sk, flags);
+                       if (err)
                                goto unlock;
+               }
+
+               used = min_t(unsigned long, used, iov_iter_count(&msg->msg_iter));
+
+               used = af_alg_make_sg(&ctx->rsgl, &msg->msg_iter, used);
+               err = used;
+               if (err < 0)
+                       goto unlock;
 
-                       if (ctx->more || used < ctx->used)
-                               used -= used % bs;
+               if (ctx->more || used < ctx->used)
+                       used -= used % bs;
 
-                       err = -EINVAL;
-                       if (!used)
-                               goto free;
+               err = -EINVAL;
+               if (!used)
+                       goto free;
 
-                       ablkcipher_request_set_crypt(&ctx->req, sg,
-                                                    ctx->rsgl.sg, used,
-                                                    ctx->iv);
+               ablkcipher_request_set_crypt(&ctx->req, sg,
+                                            ctx->rsgl.sg, used,
+                                            ctx->iv);
 
-                       err = af_alg_wait_for_completion(
+               err = af_alg_wait_for_completion(
                                ctx->enc ?
                                        crypto_ablkcipher_encrypt(&ctx->req) :
                                        crypto_ablkcipher_decrypt(&ctx->req),
                                &ctx->completion);
 
 free:
-                       af_alg_free_sg(&ctx->rsgl);
+               af_alg_free_sg(&ctx->rsgl);
 
-                       if (err)
-                               goto unlock;
+               if (err)
+                       goto unlock;
 
-                       copied += used;
-                       from += used;
-                       seglen -= used;
-                       skcipher_pull_sgl(sk, used);
-               }
+               copied += used;
+               skcipher_pull_sgl(sk, used);
+               iov_iter_advance(&msg->msg_iter, used);
        }
 
        err = 0;

diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h
index cd62bf4..88ea64e 100644 (file)
--- a/include/crypto/if_alg.h
+++ b/include/crypto/if_alg.h
@@ -67,8 +67,7 @@ int af_alg_unregister_type(const struct af_alg_type *type);
 int af_alg_release(struct socket *sock);
 int af_alg_accept(struct sock *sk, struct socket *newsock);
 
-int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len,
-                  int write);
+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);
 
 int af_alg_cmsg_send(struct msghdr *msg, struct af_alg_control *con);