diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-04-04 13:24:13 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2024-04-08 11:01:05 +0100 |
| commit | eec53cc38c4aba41bc3fabd0a75bc30c2c8ea332 (patch) | |
| tree | 671b02db22453cf2682e0c64a3ba35f007abeb11 /net/ipv6/addrlabel.c | |
| parent | 802e12ff9cbff3bafb0b6f0fe79cff04dce9de16 (diff) | |
| download | linux-eec53cc38c4aba41bc3fabd0a75bc30c2c8ea332.tar.gz linux-eec53cc38c4aba41bc3fabd0a75bc30c2c8ea332.tar.bz2 linux-eec53cc38c4aba41bc3fabd0a75bc30c2c8ea332.zip | |
ipv6: remove RTNL protection from ip6addrlbl_dump()
No longer hold RTNL while calling ip6addrlbl_dump()
("ip addrlabel show")
ip6addrlbl_dump() was already mostly relying on RCU anyway.
Add READ_ONCE()/WRITE_ONCE() annotations around
net->ipv6.ip6addrlbl_table.seq
Note that ifal_seq value is currently ignored in iproute2,
and a bit weak.
We might user later cb->seq / nl_dump_check_consistent()
protocol if needed.
Also change return value for a completed dump,
so that NLMSG_DONE can be appended to current skb,
saving one recvmsg() system call.
v2: read net->ipv6.ip6addrlbl_table.seq once, (David Ahern)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link:https://lore.kernel.org/netdev/67f5cb70-14a4-4455-8372-f039da2f15c2@kernel.org/
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/addrlabel.c')
| -rw-r--r-- | net/ipv6/addrlabel.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c index 17ac45aa7194..acd70b5992a7 100644 --- a/net/ipv6/addrlabel.c +++ b/net/ipv6/addrlabel.c @@ -234,7 +234,8 @@ static int __ip6addrlbl_add(struct net *net, struct ip6addrlbl_entry *newp, hlist_add_head_rcu(&newp->list, &net->ipv6.ip6addrlbl_table.head); out: if (!ret) - net->ipv6.ip6addrlbl_table.seq++; + WRITE_ONCE(net->ipv6.ip6addrlbl_table.seq, + net->ipv6.ip6addrlbl_table.seq + 1); return ret; } @@ -445,7 +446,7 @@ static void ip6addrlbl_putmsg(struct nlmsghdr *nlh, }; static int ip6addrlbl_fill(struct sk_buff *skb, - struct ip6addrlbl_entry *p, + const struct ip6addrlbl_entry *p, u32 lseq, u32 portid, u32 seq, int event, unsigned int flags) @@ -498,7 +499,8 @@ static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb) struct net *net = sock_net(skb->sk); struct ip6addrlbl_entry *p; int idx = 0, s_idx = cb->args[0]; - int err; + int err = 0; + u32 lseq; if (cb->strict_check) { err = ip6addrlbl_valid_dump_req(nlh, cb->extack); @@ -507,10 +509,11 @@ static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb) } rcu_read_lock(); + lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq); hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) { if (idx >= s_idx) { err = ip6addrlbl_fill(skb, p, - net->ipv6.ip6addrlbl_table.seq, + lseq, NETLINK_CB(cb->skb).portid, nlh->nlmsg_seq, RTM_NEWADDRLABEL, @@ -522,7 +525,7 @@ static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb) } rcu_read_unlock(); cb->args[0] = idx; - return skb->len; + return err; } static inline int ip6addrlbl_msgsize(void) @@ -614,7 +617,7 @@ static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr *nlh, rcu_read_lock(); p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index); - lseq = net->ipv6.ip6addrlbl_table.seq; + lseq = READ_ONCE(net->ipv6.ip6addrlbl_table.seq); if (p) err = ip6addrlbl_fill(skb, p, lseq, NETLINK_CB(in_skb).portid, @@ -647,6 +650,7 @@ int __init ipv6_addr_label_rtnl_register(void) return ret; ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, - ip6addrlbl_dump, RTNL_FLAG_DOIT_UNLOCKED); + ip6addrlbl_dump, RTNL_FLAG_DOIT_UNLOCKED | + RTNL_FLAG_DUMP_UNLOCKED); return ret; } |