diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-16 11:28:59 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-16 11:28:59 -0700 |
commit | 48bddb143befb1dd93c0e5a66af62cfd60c86b04 (patch) | |
tree | 8d71225922209f780d0e0a1f27beaac3e836972b /net/sched/cls_api.c | |
parent | c8503720fd0b952ff25bcc49b6eb9c492e22f3c6 (diff) | |
parent | 8e29f97979c300406c21994986bdfcdb67fe4ff7 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
1) Fix hotplug deadlock in hv_netvsc, from Stephen Hemminger.
2) Fix double-free in rmnet driver, from Dan Carpenter.
3) INET connection socket layer can double put request sockets, fix
from Eric Dumazet.
4) Don't match collect metadata-mode tunnels if the device is down,
from Haishuang Yan.
5) Do not perform TSO6/GSO on ipv6 packets with extensions headers in
be2net driver, from Suresh Reddy.
6) Fix scaling error in gen_estimator, from Eric Dumazet.
7) Fix 64-bit statistics deadlock in systemport driver, from Florian
Fainelli.
8) Fix use-after-free in sctp_sock_dump, from Xin Long.
9) Reject invalid BPF_END instructions in verifier, from Edward Cree.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (43 commits)
mlxsw: spectrum_router: Only handle IPv4 and IPv6 events
Documentation: link in networking docs
tcp: fix data delivery rate
bpf/verifier: reject BPF_ALU64|BPF_END
sctp: do not mark sk dumped when inet_sctp_diag_fill returns err
sctp: fix an use-after-free issue in sctp_sock_dump
netvsc: increase default receive buffer size
tcp: update skb->skb_mstamp more carefully
net: ipv4: fix l3slave check for index returned in IP_PKTINFO
net: smsc911x: Quieten netif during suspend
net: systemport: Fix 64-bit stats deadlock
net: vrf: avoid gcc-4.6 warning
qed: remove unnecessary call to memset
tg3: clean up redundant initialization of tnapi
tls: make tls_sw_free_resources static
sctp: potential read out of bounds in sctp_ulpevent_type_enabled()
MAINTAINERS: review Renesas DT bindings as well
net_sched: gen_estimator: fix scaling error in bytes/packets samples
nfp: wait for the NSP resource to appear on boot
nfp: wait for board state before talking to the NSP
...
Diffstat (limited to 'net/sched/cls_api.c')
-rw-r--r-- | net/sched/cls_api.c | 63 |
1 files changed, 40 insertions, 23 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index c743f03cfebd..0b2219adf520 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -182,7 +182,7 @@ static struct tcf_chain *tcf_chain_create(struct tcf_block *block, list_add_tail(&chain->list, &block->chain_list); chain->block = block; chain->index = chain_index; - chain->refcnt = 0; + chain->refcnt = 1; return chain; } @@ -194,21 +194,20 @@ static void tcf_chain_flush(struct tcf_chain *chain) RCU_INIT_POINTER(*chain->p_filter_chain, NULL); while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) { RCU_INIT_POINTER(chain->filter_chain, tp->next); + tcf_chain_put(chain); tcf_proto_destroy(tp); } } static void tcf_chain_destroy(struct tcf_chain *chain) { - /* May be already removed from the list by the previous call. */ - if (!list_empty(&chain->list)) - list_del_init(&chain->list); + list_del(&chain->list); + kfree(chain); +} - /* There might still be a reference held when we got here from - * tcf_block_put. Wait for the user to drop reference before free. - */ - if (!chain->refcnt) - kfree(chain); +static void tcf_chain_hold(struct tcf_chain *chain) +{ + ++chain->refcnt; } struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, @@ -217,24 +216,19 @@ struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, struct tcf_chain *chain; list_for_each_entry(chain, &block->chain_list, list) { - if (chain->index == chain_index) - goto incref; + if (chain->index == chain_index) { + tcf_chain_hold(chain); + return chain; + } } - chain = create ? tcf_chain_create(block, chain_index) : NULL; -incref: - if (chain) - chain->refcnt++; - return chain; + return create ? tcf_chain_create(block, chain_index) : NULL; } EXPORT_SYMBOL(tcf_chain_get); void tcf_chain_put(struct tcf_chain *chain) { - /* Destroy unused chain, with exception of chain 0, which is the - * default one and has to be always present. - */ - if (--chain->refcnt == 0 && !chain->filter_chain && chain->index != 0) + if (--chain->refcnt == 0) tcf_chain_destroy(chain); } EXPORT_SYMBOL(tcf_chain_put); @@ -279,10 +273,31 @@ void tcf_block_put(struct tcf_block *block) if (!block) return; - list_for_each_entry_safe(chain, tmp, &block->chain_list, list) { + /* XXX: Standalone actions are not allowed to jump to any chain, and + * bound actions should be all removed after flushing. However, + * filters are destroyed in RCU callbacks, we have to hold the chains + * first, otherwise we would always race with RCU callbacks on this list + * without proper locking. + */ + + /* Wait for existing RCU callbacks to cool down. */ + rcu_barrier(); + + /* Hold a refcnt for all chains, except 0, in case they are gone. */ + list_for_each_entry(chain, &block->chain_list, list) + if (chain->index) + tcf_chain_hold(chain); + + /* No race on the list, because no chain could be destroyed. */ + list_for_each_entry(chain, &block->chain_list, list) tcf_chain_flush(chain); - tcf_chain_destroy(chain); - } + + /* Wait for RCU callbacks to release the reference count. */ + rcu_barrier(); + + /* At this point, all the chains should have refcnt == 1. */ + list_for_each_entry_safe(chain, tmp, &block->chain_list, list) + tcf_chain_put(chain); kfree(block); } EXPORT_SYMBOL(tcf_block_put); @@ -360,6 +375,7 @@ static void tcf_chain_tp_insert(struct tcf_chain *chain, rcu_assign_pointer(*chain->p_filter_chain, tp); RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info)); rcu_assign_pointer(*chain_info->pprev, tp); + tcf_chain_hold(chain); } static void tcf_chain_tp_remove(struct tcf_chain *chain, @@ -371,6 +387,7 @@ static void tcf_chain_tp_remove(struct tcf_chain *chain, if (chain->p_filter_chain && tp == chain->filter_chain) RCU_INIT_POINTER(*chain->p_filter_chain, next); RCU_INIT_POINTER(*chain_info->pprev, next); + tcf_chain_put(chain); } static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain, |