在 2019/8/7 0:10, Pablo Neira Ayuso 写道: > On Sun, Aug 04, 2019 at 09:24:00PM +0800, wenxu@xxxxxxxxx wrote: >> diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h >> index 8f1a7b8..6022dd0 100644 >> --- a/include/net/flow_offload.h >> +++ b/include/net/flow_offload.h > [...] >> @@ -282,6 +282,8 @@ int flow_block_cb_setup_simple(struct flow_block_offload *f, >> } >> EXPORT_SYMBOL(flow_block_cb_setup_simple); >> >> +static LIST_HEAD(block_ing_cb_list); >> + >> static struct rhashtable indr_setup_block_ht; >> >> struct flow_indr_block_cb { >> @@ -295,7 +297,6 @@ struct flow_indr_block_dev { >> struct rhash_head ht_node; >> struct net_device *dev; >> unsigned int refcnt; >> - flow_indr_block_ing_cmd_t *block_ing_cmd_cb; >> struct list_head cb_list; >> }; >> >> @@ -389,6 +390,22 @@ static void flow_indr_block_cb_del(struct flow_indr_block_cb *indr_block_cb) >> kfree(indr_block_cb); >> } >> >> +static void flow_block_ing_cmd(struct net_device *dev, >> + flow_indr_block_bind_cb_t *cb, >> + void *cb_priv, >> + enum flow_block_command command) >> +{ >> + struct flow_indr_block_ing_entry *entry; >> + >> + rcu_read_lock(); >> + > unnecessary empty line. > >> + list_for_each_entry_rcu(entry, &block_ing_cb_list, list) { >> + entry->cb(dev, cb, cb_priv, command); >> + } >> + >> + rcu_read_unlock(); > OK, there's rcu_read_lock here... > >> +} >> + >> int __flow_indr_block_cb_register(struct net_device *dev, void *cb_priv, >> flow_indr_block_bind_cb_t *cb, >> void *cb_ident) >> @@ -406,10 +423,8 @@ int __flow_indr_block_cb_register(struct net_device *dev, void *cb_priv, >> if (err) >> goto err_dev_put; >> >> - if (indr_dev->block_ing_cmd_cb) >> - indr_dev->block_ing_cmd_cb(dev, indr_block_cb->cb, >> - indr_block_cb->cb_priv, >> - FLOW_BLOCK_BIND); >> + flow_block_ing_cmd(dev, indr_block_cb->cb, indr_block_cb->cb_priv, >> + FLOW_BLOCK_BIND); >> >> return 0; >> >> @@ -448,10 +463,8 @@ void __flow_indr_block_cb_unregister(struct net_device *dev, >> if (!indr_block_cb) >> return; >> >> - if (indr_dev->block_ing_cmd_cb) >> - indr_dev->block_ing_cmd_cb(dev, indr_block_cb->cb, >> - indr_block_cb->cb_priv, >> - FLOW_BLOCK_UNBIND); >> + flow_block_ing_cmd(dev, indr_block_cb->cb, indr_block_cb->cb_priv, >> + FLOW_BLOCK_UNBIND); >> >> flow_indr_block_cb_del(indr_block_cb); >> flow_indr_block_dev_put(indr_dev); >> @@ -469,7 +482,6 @@ void flow_indr_block_cb_unregister(struct net_device *dev, >> EXPORT_SYMBOL_GPL(flow_indr_block_cb_unregister); >> >> void flow_indr_block_call(struct net_device *dev, >> - flow_indr_block_ing_cmd_t cb, >> struct flow_block_offload *bo, >> enum flow_block_command command) >> { >> @@ -480,15 +492,24 @@ void flow_indr_block_call(struct net_device *dev, >> if (!indr_dev) >> return; >> >> - indr_dev->block_ing_cmd_cb = command == FLOW_BLOCK_BIND >> - ? cb : NULL; >> - >> list_for_each_entry(indr_block_cb, &indr_dev->cb_list, list) >> indr_block_cb->cb(dev, indr_block_cb->cb_priv, TC_SETUP_BLOCK, >> bo); >> } >> EXPORT_SYMBOL_GPL(flow_indr_block_call); >> >> +void flow_indr_add_block_ing_cb(struct flow_indr_block_ing_entry *entry) >> +{ > ... but registration does not protect the list with a mutex. > >> + list_add_tail_rcu(&entry->list, &block_ing_cb_list); >> +} >> +EXPORT_SYMBOL_GPL(flow_indr_add_block_ing_cb); flow_indr_add_block_ing_cb called from tc and nft in different order. subsys_initcall(tc_filter_init) and nf_tables_module_init It will be called at the same time? And any nft need flow_indr_del_block_ing_cb. It also does nedd the lock?