From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Wagner Subject: [PATCH v2 03/10] cgroup: net_cls: Protect access to task_cls_classid() when built as module Date: Fri, 24 Aug 2012 16:01:37 +0200 Message-ID: <1345816904-21745-4-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@vger.kernel.org, cgroups@vger.kernel.org Return-path: Received: from hotel311.server4you.de ([85.25.146.15]:40410 "EHLO hotel311.server4you.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932458Ab2HXOBt (ORCPT ); Fri, 24 Aug 2012 10:01:49 -0400 In-Reply-To: <1345816904-21745-1-git-send-email-wagi@monom.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Daniel Wagner The module version of task_cls_classid() checks if net_cls_sbusys_id is valid to indentify when it is okay to access the controller. Instead relying on the subusys_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@vger.kernel.org Cc: cgroups@vger.kernel.org --- include/net/cls_cgroup.h | 6 +++++- net/core/sock.c | 5 +++++ net/sched/cls_cgroup.c | 11 +++++++++++ 3 files changed, 21 insertions(+), 1 deletion(-) diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h index 401672c..24443d2 100644 --- a/include/net/cls_cgroup.h +++ b/include/net/cls_cgroup.h @@ -16,6 +16,7 @@ #include #include #include +#include #ifdef CONFIG_CGROUPS struct cgroup_cls_state @@ -45,6 +46,9 @@ static inline u32 task_cls_classid(struct task_struct *p) #elif IS_MODULE(CONFIG_NET_CLS_CGROUP) +extern struct static_key cgroup_cls_enabled; +#define clscg_enabled static_key_false(&cgroup_cls_enabled) + extern int net_cls_subsys_id; static inline u32 task_cls_classid(struct task_struct *p) @@ -52,7 +56,7 @@ static inline u32 task_cls_classid(struct task_struct *p) int id; u32 classid = 0; - if (in_interrupt()) + if (!clscg_enabled || in_interrupt()) return 0; rcu_read_lock(); diff --git a/net/core/sock.c b/net/core/sock.c index 8f67ced..8106e77 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -327,6 +327,11 @@ int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) EXPORT_SYMBOL(__sk_backlog_rcv); #if defined(CONFIG_CGROUPS) +#if IS_MODULE(CONFIG_NET_CLS_CGROUP) +struct static_key cgroup_cls_enabled = STATIC_KEY_INIT_FALSE; +EXPORT_SYMBOL_GPL(cgroup_cls_enabled); +#endif + #if !defined(CONFIG_NET_CLS_CGROUP) int net_cls_subsys_id = -1; EXPORT_SYMBOL_GPL(net_cls_subsys_id); diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c index 7743ea8..554dc5b 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -293,6 +293,12 @@ static int __init init_cgroup_cls(void) if (ret) cgroup_unload_subsys(&net_cls_subsys); +#if IS_MODULE(CONFIG_NET_CLS_CGROUP) + if (ret) + goto out; + static_key_slow_inc(&cgroup_cls_enabled); +#endif + out: return ret; } @@ -306,6 +312,11 @@ static void __exit exit_cgroup_cls(void) synchronize_rcu(); #endif +#if IS_MODULE(CONFIG_NET_CLS_CGROUP) + static_key_slow_dec(&cgroup_cls_enabled); + rcu_barrier(); +#endif + cgroup_unload_subsys(&net_cls_subsys); } -- 1.7.12.rc1.16.g05a20c8