Commit 7cc05662 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David S. Miller
Browse files

net: remove sock_iocb 



The sock_iocb structure is allocate on stack for each read/write-like
operation on sockets, and contains various fields of which only the
embedded msghdr and sometimes a pointer to the scm_cookie is ever used.
Get rid of the sock_iocb and put a msghdr directly on the stack and pass
the scm_cookie explicitly to netlink_mmap_sendmsg.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a154e6f6

include/net/sock.h

+0 −23
Original line number Diff line number Diff line
@@ -1374,29 +1374,6 @@ void sk_prot_clear_portaddr_nulls(struct sock *sk, int size); 
#define SOCK_BINDADDR_LOCK	4

#define SOCK_BINDPORT_LOCK	8



/* sock_iocb: used to kick off async processing of socket ios */

struct sock_iocb {

	struct list_head	list;



	int			flags;

	int			size;

	struct socket		*sock;

	struct sock		*sk;

	struct scm_cookie	*scm;

	struct msghdr		*msg, async_msg;

	struct kiocb		*kiocb;

};



static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)

{

	return (struct sock_iocb *)iocb->private;

}



static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)

{

	return si->kiocb;

}



struct socket_alloc {

	struct socket socket;

	struct inode vfs_inode;

net/netlink/af_netlink.c

+10 −18
Original line number Diff line number Diff line
@@ -695,7 +695,7 @@ static void netlink_ring_setup_skb(struct sk_buff *skb, struct sock *sk, 


static int netlink_mmap_sendmsg(struct sock *sk, struct msghdr *msg,

				u32 dst_portid, u32 dst_group,

				struct sock_iocb *siocb)

				struct scm_cookie *scm)

{

	struct netlink_sock *nlk = nlk_sk(sk);

	struct netlink_ring *ring;
@@ -741,7 +741,7 @@ static int netlink_mmap_sendmsg(struct sock *sk, struct msghdr *msg, 


		NETLINK_CB(skb).portid	  = nlk->portid;

		NETLINK_CB(skb).dst_group = dst_group;

		NETLINK_CB(skb).creds	  = siocb->scm->creds;

		NETLINK_CB(skb).creds	  = scm->creds;



		err = security_netlink_send(sk, skb);

		if (err) {
@@ -820,7 +820,7 @@ static void netlink_ring_set_copied(struct sock *sk, struct sk_buff *skb) 
#define netlink_tx_is_mmaped(sk)	false

#define netlink_mmap			sock_no_mmap

#define netlink_poll			datagram_poll

#define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, siocb)	0

#define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, scm)	0

#endif /* CONFIG_NETLINK_MMAP */



static void netlink_skb_destructor(struct sk_buff *skb)
@@ -2259,7 +2259,6 @@ static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) 
static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,

			   struct msghdr *msg, size_t len)

{

	struct sock_iocb *siocb = kiocb_to_siocb(kiocb);

	struct sock *sk = sock->sk;

	struct netlink_sock *nlk = nlk_sk(sk);

	DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
@@ -2273,10 +2272,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, 
	if (msg->msg_flags&MSG_OOB)

		return -EOPNOTSUPP;



	if (NULL == siocb->scm)

		siocb->scm = &scm;



	err = scm_send(sock, msg, siocb->scm, true);

	err = scm_send(sock, msg, &scm, true);

	if (err < 0)

		return err;
@@ -2305,7 +2301,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, 
	if (netlink_tx_is_mmaped(sk) &&

	    msg->msg_iter.iov->iov_base == NULL) {

		err = netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group,

					   siocb);

					   &scm);

		goto out;

	}
@@ -2319,7 +2315,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, 


	NETLINK_CB(skb).portid	= nlk->portid;

	NETLINK_CB(skb).dst_group = dst_group;

	NETLINK_CB(skb).creds	= siocb->scm->creds;

	NETLINK_CB(skb).creds	= scm.creds;

	NETLINK_CB(skb).flags	= netlink_skb_flags;



	err = -EFAULT;
@@ -2341,7 +2337,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, 
	err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT);



out:

	scm_destroy(siocb->scm);

	scm_destroy(&scm);

	return err;

}
@@ -2349,7 +2345,6 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, 
			   struct msghdr *msg, size_t len,

			   int flags)

{

	struct sock_iocb *siocb = kiocb_to_siocb(kiocb);

	struct scm_cookie scm;

	struct sock *sk = sock->sk;

	struct netlink_sock *nlk = nlk_sk(sk);
@@ -2412,11 +2407,8 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, 
	if (nlk->flags & NETLINK_RECV_PKTINFO)

		netlink_cmsg_recv_pktinfo(msg, skb);



	if (NULL == siocb->scm) {

	memset(&scm, 0, sizeof(scm));

		siocb->scm = &scm;

	}

	siocb->scm->creds = *NETLINK_CREDS(skb);

	scm.creds = *NETLINK_CREDS(skb);

	if (flags & MSG_TRUNC)

		copied = data_skb->len;
@@ -2431,7 +2423,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, 
		}

	}



	scm_recv(sock, msg, siocb->scm, flags);

	scm_recv(sock, msg, &scm, flags);

out:

	netlink_rcv_wake(sk);

	return err ? : copied;

net/socket.c

+4 −41
Original line number Diff line number Diff line
@@ -613,13 +613,6 @@ EXPORT_SYMBOL(__sock_tx_timestamp); 
static inline int __sock_sendmsg_nosec(struct kiocb *iocb, struct socket *sock,

				       struct msghdr *msg, size_t size)

{

	struct sock_iocb *si = kiocb_to_siocb(iocb);



	si->sock = sock;

	si->scm = NULL;

	si->msg = msg;

	si->size = size;



	return sock->ops->sendmsg(iocb, sock, msg, size);

}
@@ -635,11 +628,9 @@ static int do_sock_sendmsg(struct socket *sock, struct msghdr *msg, 
			   size_t size, bool nosec)

{

	struct kiocb iocb;

	struct sock_iocb siocb;

	int ret;



	init_sync_kiocb(&iocb, NULL);

	iocb.private = &siocb;

	ret = nosec ? __sock_sendmsg_nosec(&iocb, sock, msg, size) :

		      __sock_sendmsg(&iocb, sock, msg, size);

	if (-EIOCBQUEUED == ret)
@@ -756,14 +747,6 @@ EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops); 
static inline int __sock_recvmsg_nosec(struct kiocb *iocb, struct socket *sock,

				       struct msghdr *msg, size_t size, int flags)

{

	struct sock_iocb *si = kiocb_to_siocb(iocb);



	si->sock = sock;

	si->scm = NULL;

	si->msg = msg;

	si->size = size;

	si->flags = flags;



	return sock->ops->recvmsg(iocb, sock, msg, size, flags);

}
@@ -779,11 +762,9 @@ int sock_recvmsg(struct socket *sock, struct msghdr *msg, 
		 size_t size, int flags)

{

	struct kiocb iocb;

	struct sock_iocb siocb;

	int ret;



	init_sync_kiocb(&iocb, NULL);

	iocb.private = &siocb;

	ret = __sock_recvmsg(&iocb, sock, msg, size, flags);

	if (-EIOCBQUEUED == ret)

		ret = wait_on_sync_kiocb(&iocb);
@@ -795,11 +776,9 @@ static int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg, 
			      size_t size, int flags)

{

	struct kiocb iocb;

	struct sock_iocb siocb;

	int ret;



	init_sync_kiocb(&iocb, NULL);

	iocb.private = &siocb;

	ret = __sock_recvmsg_nosec(&iocb, sock, msg, size, flags);

	if (-EIOCBQUEUED == ret)

		ret = wait_on_sync_kiocb(&iocb);
@@ -866,14 +845,6 @@ static ssize_t sock_splice_read(struct file *file, loff_t *ppos, 
	return sock->ops->splice_read(sock, ppos, pipe, len, flags);

}



static struct sock_iocb *alloc_sock_iocb(struct kiocb *iocb,

					 struct sock_iocb *siocb)

{

	siocb->kiocb = iocb;

	iocb->private = siocb;

	return siocb;

}



static ssize_t do_sock_read(struct msghdr *msg, struct kiocb *iocb,

		struct file *file, const struct iovec *iov,

		unsigned long nr_segs)
@@ -893,7 +864,7 @@ static ssize_t do_sock_read(struct msghdr *msg, struct kiocb *iocb, 
static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,

				unsigned long nr_segs, loff_t pos)

{

	struct sock_iocb siocb, *x;

	struct msghdr msg;



	if (pos != 0)

		return -ESPIPE;
@@ -901,11 +872,7 @@ static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov, 
	if (iocb->ki_nbytes == 0)	/* Match SYS5 behaviour */

		return 0;





	x = alloc_sock_iocb(iocb, &siocb);

	if (!x)

		return -ENOMEM;

	return do_sock_read(&x->async_msg, iocb, iocb->ki_filp, iov, nr_segs);

	return do_sock_read(&msg, iocb, iocb->ki_filp, iov, nr_segs);

}



static ssize_t do_sock_write(struct msghdr *msg, struct kiocb *iocb,
@@ -929,16 +896,12 @@ static ssize_t do_sock_write(struct msghdr *msg, struct kiocb *iocb, 
static ssize_t sock_aio_write(struct kiocb *iocb, const struct iovec *iov,

			  unsigned long nr_segs, loff_t pos)

{

	struct sock_iocb siocb, *x;

	struct msghdr msg;



	if (pos != 0)

		return -ESPIPE;



	x = alloc_sock_iocb(iocb, &siocb);

	if (!x)

		return -ENOMEM;



	return do_sock_write(&x->async_msg, iocb, iocb->ki_filp, iov, nr_segs);

	return do_sock_write(&msg, iocb, iocb->ki_filp, iov, nr_segs);

}



/*

net/unix/af_unix.c

+29 −44
Original line number Diff line number Diff line
@@ -1445,7 +1445,6 @@ static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock, 
static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,

			      struct msghdr *msg, size_t len)

{

	struct sock_iocb *siocb = kiocb_to_siocb(kiocb);

	struct sock *sk = sock->sk;

	struct net *net = sock_net(sk);

	struct unix_sock *u = unix_sk(sk);
@@ -1456,14 +1455,12 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, 
	unsigned int hash;

	struct sk_buff *skb;

	long timeo;

	struct scm_cookie tmp_scm;

	struct scm_cookie scm;

	int max_level;

	int data_len = 0;



	if (NULL == siocb->scm)

		siocb->scm = &tmp_scm;

	wait_for_unix_gc();

	err = scm_send(sock, msg, siocb->scm, false);

	err = scm_send(sock, msg, &scm, false);

	if (err < 0)

		return err;
@@ -1507,11 +1504,11 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock, 
	if (skb == NULL)

		goto out;



	err = unix_scm_to_skb(siocb->scm, skb, true);

	err = unix_scm_to_skb(&scm, skb, true);

	if (err < 0)

		goto out_free;

	max_level = err + 1;

	unix_get_secdata(siocb->scm, skb);

	unix_get_secdata(&scm, skb);



	skb_put(skb, len - data_len);

	skb->data_len = data_len;
@@ -1606,7 +1603,7 @@ restart: 
	unix_state_unlock(other);

	other->sk_data_ready(other);

	sock_put(other);

	scm_destroy(siocb->scm);

	scm_destroy(&scm);

	return len;



out_unlock:
@@ -1616,7 +1613,7 @@ out_free: 
out:

	if (other)

		sock_put(other);

	scm_destroy(siocb->scm);

	scm_destroy(&scm);

	return err;

}
@@ -1628,21 +1625,18 @@ out: 
static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,

			       struct msghdr *msg, size_t len)

{

	struct sock_iocb *siocb = kiocb_to_siocb(kiocb);

	struct sock *sk = sock->sk;

	struct sock *other = NULL;

	int err, size;

	struct sk_buff *skb;

	int sent = 0;

	struct scm_cookie tmp_scm;

	struct scm_cookie scm;

	bool fds_sent = false;

	int max_level;

	int data_len;



	if (NULL == siocb->scm)

		siocb->scm = &tmp_scm;

	wait_for_unix_gc();

	err = scm_send(sock, msg, siocb->scm, false);

	err = scm_send(sock, msg, &scm, false);

	if (err < 0)

		return err;
@@ -1683,7 +1677,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 
			goto out_err;



		/* Only send the fds in the first buffer */

		err = unix_scm_to_skb(siocb->scm, skb, !fds_sent);

		err = unix_scm_to_skb(&scm, skb, !fds_sent);

		if (err < 0) {

			kfree_skb(skb);

			goto out_err;
@@ -1715,8 +1709,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 
		sent += size;

	}



	scm_destroy(siocb->scm);

	siocb->scm = NULL;

	scm_destroy(&scm);



	return sent;
@@ -1728,8 +1721,7 @@ pipe_err: 
		send_sig(SIGPIPE, current, 0);

	err = -EPIPE;

out_err:

	scm_destroy(siocb->scm);

	siocb->scm = NULL;

	scm_destroy(&scm);

	return sent ? : err;

}
@@ -1778,8 +1770,7 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 
			      struct msghdr *msg, size_t size,

			      int flags)

{

	struct sock_iocb *siocb = kiocb_to_siocb(iocb);

	struct scm_cookie tmp_scm;

	struct scm_cookie scm;

	struct sock *sk = sock->sk;

	struct unix_sock *u = unix_sk(sk);

	int noblock = flags & MSG_DONTWAIT;
@@ -1831,16 +1822,14 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 
	if (sock_flag(sk, SOCK_RCVTSTAMP))

		__sock_recv_timestamp(msg, sk, skb);



	if (!siocb->scm) {

		siocb->scm = &tmp_scm;

		memset(&tmp_scm, 0, sizeof(tmp_scm));

	}

	scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);

	unix_set_secdata(siocb->scm, skb);

	memset(&scm, 0, sizeof(scm));



	scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);

	unix_set_secdata(&scm, skb);



	if (!(flags & MSG_PEEK)) {

		if (UNIXCB(skb).fp)

			unix_detach_fds(siocb->scm, skb);

			unix_detach_fds(&scm, skb);



		sk_peek_offset_bwd(sk, skb->len);

	} else {
@@ -1860,11 +1849,11 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, 
		sk_peek_offset_fwd(sk, size);



		if (UNIXCB(skb).fp)

			siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);

			scm.fp = scm_fp_dup(UNIXCB(skb).fp);

	}

	err = (flags & MSG_TRUNC) ? skb->len - skip : size;



	scm_recv(sock, msg, siocb->scm, flags);

	scm_recv(sock, msg, &scm, flags);



out_free:

	skb_free_datagram(sk, skb);
@@ -1915,8 +1904,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 
			       struct msghdr *msg, size_t size,

			       int flags)

{

	struct sock_iocb *siocb = kiocb_to_siocb(iocb);

	struct scm_cookie tmp_scm;

	struct scm_cookie scm;

	struct sock *sk = sock->sk;

	struct unix_sock *u = unix_sk(sk);

	DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name);
@@ -1943,10 +1931,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, 
	 * while sleeps in memcpy_tomsg

	 */



	if (!siocb->scm) {

		siocb->scm = &tmp_scm;

		memset(&tmp_scm, 0, sizeof(tmp_scm));

	}

	memset(&scm, 0, sizeof(scm));



	err = mutex_lock_interruptible(&u->readlock);

	if (unlikely(err)) {
@@ -2012,13 +1997,13 @@ again: 


		if (check_creds) {

			/* Never glue messages from different writers */

			if ((UNIXCB(skb).pid  != siocb->scm->pid) ||

			    !uid_eq(UNIXCB(skb).uid, siocb->scm->creds.uid) ||

			    !gid_eq(UNIXCB(skb).gid, siocb->scm->creds.gid))

			if ((UNIXCB(skb).pid  != scm.pid) ||

			    !uid_eq(UNIXCB(skb).uid, scm.creds.uid) ||

			    !gid_eq(UNIXCB(skb).gid, scm.creds.gid))

				break;

		} else if (test_bit(SOCK_PASSCRED, &sock->flags)) {

			/* Copy credentials */

			scm_set_cred(siocb->scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);

			scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);

			check_creds = 1;

		}
@@ -2045,7 +2030,7 @@ again: 
			sk_peek_offset_bwd(sk, chunk);



			if (UNIXCB(skb).fp)

				unix_detach_fds(siocb->scm, skb);

				unix_detach_fds(&scm, skb);



			if (unix_skb_len(skb))

				break;
@@ -2053,13 +2038,13 @@ again: 
			skb_unlink(skb, &sk->sk_receive_queue);

			consume_skb(skb);



			if (siocb->scm->fp)

			if (scm.fp)

				break;

		} else {

			/* It is questionable, see note in unix_dgram_recvmsg.

			 */

			if (UNIXCB(skb).fp)

				siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);

				scm.fp = scm_fp_dup(UNIXCB(skb).fp);



			sk_peek_offset_fwd(sk, chunk);
@@ -2068,7 +2053,7 @@ again: 
	} while (size);



	mutex_unlock(&u->readlock);

	scm_recv(sock, msg, siocb->scm, flags);

	scm_recv(sock, msg, &scm, flags);

out:

	return copied ? : err;

}

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