From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: [PATCH v2 10/18] tipc: tipc ->sendmsg() conversion Date: Mon, 2 Feb 2015 07:59:29 +0000 Message-ID: <1422863977-17668-10-git-send-email-viro@ZenIV.linux.org.uk> References: <20150131035513.GK29656@ZenIV.linux.org.uk> Cc: netdev@vger.kernel.org, Jon Maloy To: David Miller Return-path: Received: from zeniv.linux.org.uk ([195.92.253.2]:32979 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932601AbbBBH7j (ORCPT ); Mon, 2 Feb 2015 02:59:39 -0500 In-Reply-To: <20150131035513.GK29656@ZenIV.linux.org.uk> Sender: netdev-owner@vger.kernel.org List-ID: From: Al Viro This one needs to copy the same data from user potentially more than once. Sadly, MTU changes can trigger that ;-/ Cc: Jon Maloy Signed-off-by: Al Viro --- net/tipc/msg.c | 7 ++----- net/tipc/socket.c | 14 ++++++++++++-- 2 files changed, 14 insertions(+), 7 deletions(-) diff --git a/net/tipc/msg.c b/net/tipc/msg.c index 18aba9e..da67c8d 100644 --- a/net/tipc/msg.c +++ b/net/tipc/msg.c @@ -189,7 +189,6 @@ err: * tipc_msg_build - create buffer chain containing specified header and data * @mhdr: Message header, to be prepended to data * @m: User message - * @offset: Posision in iov to start copying from * @dsz: Total length of user data * @pktmax: Max packet size that can be used * @list: Buffer or chain of buffers to be returned to caller @@ -221,8 +220,7 @@ int tipc_msg_build(struct net *net, struct tipc_msg *mhdr, struct msghdr *m, __skb_queue_tail(list, skb); skb_copy_to_linear_data(skb, mhdr, mhsz); pktpos = skb->data + mhsz; - if (!dsz || !memcpy_fromiovecend(pktpos, m->msg_iter.iov, offset, - dsz)) + if (copy_from_iter(pktpos, dsz, &m->msg_iter) == dsz) return dsz; rc = -EFAULT; goto error; @@ -252,12 +250,11 @@ int tipc_msg_build(struct net *net, struct tipc_msg *mhdr, struct msghdr *m, if (drem < pktrem) pktrem = drem; - if (memcpy_fromiovecend(pktpos, m->msg_iter.iov, offset, pktrem)) { + if (copy_from_iter(pktpos, pktrem, &m->msg_iter) != pktrem) { rc = -EFAULT; goto error; } drem -= pktrem; - offset += pktrem; if (!drem) break; diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 679a220..caa4d66 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -733,6 +733,7 @@ static int tipc_sendmcast(struct socket *sock, struct tipc_name_seq *seq, struct net *net = sock_net(sk); struct tipc_msg *mhdr = &tipc_sk(sk)->phdr; struct sk_buff_head head; + struct iov_iter save = msg->msg_iter; uint mtu; int rc; @@ -758,8 +759,10 @@ new_mtu: rc = dsz; break; } - if (rc == -EMSGSIZE) + if (rc == -EMSGSIZE) { + msg->msg_iter = save; goto new_mtu; + } if (rc != -ELINKCONG) break; tipc_sk(sk)->link_cong = 1; @@ -895,6 +898,7 @@ static int tipc_sendmsg(struct kiocb *iocb, struct socket *sock, struct sk_buff_head head; struct sk_buff *skb; struct tipc_name_seq *seq = &dest->addr.nameseq; + struct iov_iter save; u32 mtu; long timeo; int rc; @@ -963,6 +967,7 @@ static int tipc_sendmsg(struct kiocb *iocb, struct socket *sock, msg_set_hdr_sz(mhdr, BASIC_H_SIZE); } + save = m->msg_iter; new_mtu: mtu = tipc_node_get_mtu(net, dnode, tsk->portid); __skb_queue_head_init(&head); @@ -980,8 +985,10 @@ new_mtu: rc = dsz; break; } - if (rc == -EMSGSIZE) + if (rc == -EMSGSIZE) { + m->msg_iter = save; goto new_mtu; + } if (rc != -ELINKCONG) break; tsk->link_cong = 1; @@ -1052,6 +1059,7 @@ static int tipc_send_stream(struct kiocb *iocb, struct socket *sock, long timeo; u32 dnode; uint mtu, send, sent = 0; + struct iov_iter save; /* Handle implied connection establishment */ if (unlikely(dest)) { @@ -1078,6 +1086,7 @@ static int tipc_send_stream(struct kiocb *iocb, struct socket *sock, dnode = tsk_peer_node(tsk); next: + save = m->msg_iter; mtu = tsk->max_pkt; send = min_t(uint, dsz - sent, TIPC_MAX_USER_MSG_SIZE); __skb_queue_head_init(&head); @@ -1097,6 +1106,7 @@ next: if (rc == -EMSGSIZE) { tsk->max_pkt = tipc_node_get_mtu(net, dnode, portid); + m->msg_iter = save; goto next; } if (rc != -ELINKCONG) -- 2.1.4