switch kernel_sendmsg() and kernel_recvmsg() to iov_iter_kvec()

For kernel_sendmsg() that eliminates the need to play with setfs();
for kernel_recvmsg() it does *not* - a couple of callers are using
it with non-NULL ->msg_control, which would be treated as userland
address on recvmsg side of things.

In all cases we are really setting a kvec-backed iov_iter, though.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-03-21 19:56:16 -04:00
Родитель da18428498
Коммит 6aa248145a
1 изменённых файлов: 3 добавлений и 17 удалений

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@ -627,18 +627,8 @@ EXPORT_SYMBOL(sock_sendmsg);
int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
struct kvec *vec, size_t num, size_t size)
{
mm_segment_t oldfs = get_fs();
int result;
set_fs(KERNEL_DS);
/*
* the following is safe, since for compiler definitions of kvec and
* iovec are identical, yielding the same in-core layout and alignment
*/
iov_iter_init(&msg->msg_iter, WRITE, (struct iovec *)vec, num, size);
result = sock_sendmsg(sock, msg, size);
set_fs(oldfs);
return result;
iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, vec, num, size);
return sock_sendmsg(sock, msg, size);
}
EXPORT_SYMBOL(kernel_sendmsg);
@ -755,12 +745,8 @@ int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
mm_segment_t oldfs = get_fs();
int result;
iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, vec, num, size);
set_fs(KERNEL_DS);
/*
* the following is safe, since for compiler definitions of kvec and
* iovec are identical, yielding the same in-core layout and alignment
*/
iov_iter_init(&msg->msg_iter, READ, (struct iovec *)vec, num, size);
result = sock_recvmsg(sock, msg, size, flags);
set_fs(oldfs);
return result;