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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-05-25 07:34:04 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-05-25 17:55:32 -0400 |
| commit | 2907c35ff64708065e5a7fd54e8ded8263eb3074 (patch) | |
| tree | b5046b08b0b4b13c45a2fffef4ad3218c9db07d8 /net | |
| parent | 1dcb14d9e874d12bab9ceeba776b742f1682b0a6 (diff) | |
| download | lwn-2907c35ff64708065e5a7fd54e8ded8263eb3074.tar.gz lwn-2907c35ff64708065e5a7fd54e8ded8263eb3074.zip | |
net: hold rtnl again in dump callbacks
Commit e67f88dd12f6 (dont hold rtnl mutex during netlink dump callbacks)
missed fact that rtnl_fill_ifinfo() must be called with rtnl held.
Because of possible deadlocks between two mutexes (cb_mutex and rtnl),
its not easy to solve this problem, so revert this part of the patch.
It also forgot one rcu_read_unlock() in FIB dump_rules()
Add one ASSERT_RTNL() in rtnl_fill_ifinfo() to remind us the rule.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McHardy <kaber@trash.net>
CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/fib_rules.c | 1 | ||||
| -rw-r--r-- | net/core/rtnetlink.c | 9 |
2 files changed, 8 insertions, 2 deletions
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index 3911586e12e4..008dc70b064b 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -602,6 +602,7 @@ static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, skip: idx++; } + rcu_read_unlock(); cb->args[1] = idx; rules_ops_put(ops); diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index d1644e317e70..2d56cb9b0b94 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -850,6 +850,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, struct nlattr *attr, *af_spec; struct rtnl_af_ops *af_ops; + ASSERT_RTNL(); nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ifm), flags); if (nlh == NULL) return -EMSGSIZE; @@ -1876,6 +1877,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) int min_len; int family; int type; + int err; type = nlh->nlmsg_type; if (type > RTM_MAX) @@ -1902,8 +1904,11 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (dumpit == NULL) return -EOPNOTSUPP; + __rtnl_unlock(); rtnl = net->rtnl; - return netlink_dump_start(rtnl, skb, nlh, dumpit, NULL); + err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL); + rtnl_lock(); + return err; } memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *))); @@ -1975,7 +1980,7 @@ static int __net_init rtnetlink_net_init(struct net *net) { struct sock *sk; sk = netlink_kernel_create(net, NETLINK_ROUTE, RTNLGRP_MAX, - rtnetlink_rcv, NULL, THIS_MODULE); + rtnetlink_rcv, &rtnl_mutex, THIS_MODULE); if (!sk) return -ENOMEM; net->rtnl = sk; |