From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Wagner Subject: [PATCH v1 3/5] cgroup: Protect access to task_cls_classid() when built as module Date: Fri, 17 Aug 2012 16:58:12 +0200 Message-ID: <1345215494-9181-4-git-send-email-wagi@monom.org> References: <1345215494-9181-1-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: <1345215494-9181-1-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_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-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org --- include/net/cls_cgroup.h | 5 ++++- net/core/sock.c | 5 +++++ net/sched/cls_cgroup.c | 9 +++++++++ 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h index 401672c..bbbd957 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 @@ -44,6 +45,8 @@ 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; @@ -52,7 +55,7 @@ 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..0635894 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -44,12 +44,21 @@ static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp) if (cgrp->parent) cs->classid = cgrp_cls_state(cgrp->parent)->classid; +#if IS_MODULE(CONFIG_NET_CLS_CGROUP) + else if (!clscg_enabled) + static_key_slow_inc(&cgroup_cls_enabled); +#endif return &cs->css; } static void cgrp_destroy(struct cgroup *cgrp) { +#if IS_MODULE(CONFIG_NET_CLS_CGROUP) + if (!cgrp->parent && clscg_enabled) + static_key_slow_dec(&cgroup_cls_enabled); +#endif + kfree(cgrp_cls_state(cgrp)); } -- 1.7.12.rc1.16.g05a20c8