From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Wagner Subject: [PATCH v2 04/10] cgroup: net_prio: Protect access to task_netprioidx() when built as module Date: Fri, 24 Aug 2012 16:01:38 +0200 Message-ID: <1345816904-21745-5-git-send-email-wagi@monom.org> References: <1345816904-21745-1-git-send-email-wagi@monom.org> Cc: Daniel Wagner , "David S. Miller" , Gao feng , Jamal Hadi Salim , John Fastabend , Li Zefan , Neil Horman , Tejun Heo To: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: In-Reply-To: <1345816904-21745-1-git-send-email-wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org From: Daniel Wagner The module version of task_netprioidex() checks if net_prio_subsys_id is valid to indentify when it is okay to access the controller. Instead relying on the net_prio_subsys_id to be set, make it explicit with a jump label. Signed-off-by: Daniel Wagner Cc: "David S. Miller" Cc: Gao feng Cc: Jamal Hadi Salim Cc: John Fastabend Cc: Li Zefan Cc: Neil Horman Cc: Tejun Heo Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org --- include/net/netprio_cgroup.h | 8 +++++++- net/core/netprio_cgroup.c | 9 +++++++++ net/core/sock.c | 4 ++++ 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/include/net/netprio_cgroup.h b/include/net/netprio_cgroup.h index 2719dec..9ff58e4 100644 --- a/include/net/netprio_cgroup.h +++ b/include/net/netprio_cgroup.h @@ -16,7 +16,7 @@ #include #include #include - +#include struct netprio_map { struct rcu_head rcu; @@ -54,12 +54,18 @@ static inline u32 task_netprioidx(struct task_struct *p) #elif IS_MODULE(CONFIG_NETPRIO_CGROUP) +extern struct static_key cgroup_netprio_enabled; +#define netpriocg_enabled static_key_false(&cgroup_netprio_enabled) + static inline u32 task_netprioidx(struct task_struct *p) { struct cgroup_netprio_state *state; int subsys_id; u32 idx = 0; + if (!netpriocg_enabled) + return 0; + rcu_read_lock(); subsys_id = rcu_dereference_index_check(net_prio_subsys_id, rcu_read_lock_held()); diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index c75e3f9..400ab94 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -371,6 +371,10 @@ static int __init init_cgroup_netprio(void) net_prio_subsys_id = net_prio_subsys.subsys_id; #endif +#if IS_MODULE(CONFIG_NETPRIO_CGROUP) + static_key_slow_inc(&cgroup_netprio_enabled); +#endif + register_netdevice_notifier(&netprio_device_notifier); out: @@ -391,6 +395,11 @@ static void __exit exit_cgroup_netprio(void) synchronize_rcu(); #endif +#if IS_MODULE(CONFIG_NETPRIO_CGROUP) + static_key_slow_dec(&cgroup_netprio_enabled); + rcu_barrier(); +#endif + rtnl_lock(); for_each_netdev(&init_net, dev) { old = rtnl_dereference(dev->priomap); diff --git a/net/core/sock.c b/net/core/sock.c index 8106e77..1f119d2 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -331,6 +331,10 @@ EXPORT_SYMBOL(__sk_backlog_rcv); struct static_key cgroup_cls_enabled = STATIC_KEY_INIT_FALSE; EXPORT_SYMBOL_GPL(cgroup_cls_enabled); #endif +#if IS_MODULE(CONFIG_NETPRIO_CGROUP) +struct static_key cgroup_netprio_enabled = STATIC_KEY_INIT_FALSE; +EXPORT_SYMBOL_GPL(cgroup_netprio_enabled); +#endif #if !defined(CONFIG_NET_CLS_CGROUP) int net_cls_subsys_id = -1; -- 1.7.12.rc1.16.g05a20c8