diff options
| author | Vlad Buslov <vladbu@mellanox.com> | 2018-08-10 20:51:49 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-08-11 12:37:09 -0700 |
| commit | c8814552fe51358f5fc46bc1c4aa4bb68454f4eb (patch) | |
| tree | 71af6a057faa64a3c469f9491320e50df0697486 /net | |
| parent | 5e48180ed8bcfa60e02887ba801307caf14bbe40 (diff) | |
net: sched: act_skbmod: remove dependency on rtnl lock
Move read of skbmod_p rcu pointer to be protected by tcf spinlock. Use tcf
spinlock to protect private skbmod data from concurrent modification during
dump.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sched/act_skbmod.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c index c437c6d51a71..e9c86ade3b40 100644 --- a/net/sched/act_skbmod.c +++ b/net/sched/act_skbmod.c @@ -156,7 +156,6 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla, d = to_skbmod(*a); - ASSERT_RTNL(); p = kzalloc(sizeof(struct tcf_skbmod_params), GFP_KERNEL); if (unlikely(!p)) { tcf_idr_release(*a, bind); @@ -166,10 +165,10 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla, p->flags = lflags; d->tcf_action = parm->action; - p_old = rtnl_dereference(d->skbmod_p); - if (ovr) spin_lock_bh(&d->tcf_lock); + /* Protected by tcf_lock if overwriting existing action. */ + p_old = rcu_dereference_protected(d->skbmod_p, 1); if (lflags & SKBMOD_F_DMAC) ether_addr_copy(p->eth_dst, daddr); @@ -205,15 +204,18 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a, { struct tcf_skbmod *d = to_skbmod(a); unsigned char *b = skb_tail_pointer(skb); - struct tcf_skbmod_params *p = rtnl_dereference(d->skbmod_p); + struct tcf_skbmod_params *p; struct tc_skbmod opt = { .index = d->tcf_index, .refcnt = refcount_read(&d->tcf_refcnt) - ref, .bindcnt = atomic_read(&d->tcf_bindcnt) - bind, - .action = d->tcf_action, }; struct tcf_t t; + spin_lock_bh(&d->tcf_lock); + opt.action = d->tcf_action; + p = rcu_dereference_protected(d->skbmod_p, + lockdep_is_held(&d->tcf_lock)); opt.flags = p->flags; if (nla_put(skb, TCA_SKBMOD_PARMS, sizeof(opt), &opt)) goto nla_put_failure; @@ -231,8 +233,10 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a, if (nla_put_64bit(skb, TCA_SKBMOD_TM, sizeof(t), &t, TCA_SKBMOD_PAD)) goto nla_put_failure; + spin_unlock_bh(&d->tcf_lock); return skb->len; nla_put_failure: + spin_unlock_bh(&d->tcf_lock); nlmsg_trim(skb, b); return -1; } |