diff options
| author | Vlad Buslov <vladbu@mellanox.com> | 2019-02-11 10:55:38 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-02-12 13:41:32 -0500 |
| commit | ed76f5edccc98fa66f2337f0b3b255d6e1a568b7 (patch) | |
| tree | 408b13681d6f13914e70783a7d345a560242a219 /net/sched/sch_generic.c | |
| parent | a5654820bb4b1f5f21eb83b8fb9de79ce1382d2b (diff) | |
| download | lwn-ed76f5edccc98fa66f2337f0b3b255d6e1a568b7.tar.gz lwn-ed76f5edccc98fa66f2337f0b3b255d6e1a568b7.zip | |
net: sched: protect filter_chain list with filter_chain_lock mutex
Extend tcf_chain with new filter_chain_lock mutex. Always lock the chain
when accessing filter_chain list, instead of relying on rtnl lock.
Dereference filter_chain with tcf_chain_dereference() lockdep macro to
verify that all users of chain_list have the lock taken.
Rearrange tp insert/remove code in tc_new_tfilter/tc_del_tfilter to execute
all necessary code while holding chain lock in order to prevent
invalidation of chain_info structure by potential concurrent change. This
also serializes calls to tcf_chain0_head_change(), which allows head change
callbacks to rely on filter_chain_lock for synchronization instead of rtnl
mutex.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_generic.c')
| -rw-r--r-- | net/sched/sch_generic.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 66ba2ce2320f..e24568f9246c 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1366,7 +1366,11 @@ static void mini_qdisc_rcu_func(struct rcu_head *head) void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp, struct tcf_proto *tp_head) { - struct mini_Qdisc *miniq_old = rtnl_dereference(*miniqp->p_miniq); + /* Protected with chain0->filter_chain_lock. + * Can't access chain directly because tp_head can be NULL. + */ + struct mini_Qdisc *miniq_old = + rcu_dereference_protected(*miniqp->p_miniq, 1); struct mini_Qdisc *miniq; if (!tp_head) { |