From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Wagner Subject: [PATCH v0 3/5] cgroup: Protect access to task_cls_classid() when built as module Date: Thu, 16 Aug 2012 16:12:14 +0200 Message-ID: <1345126336-20755-4-git-send-email-wagi@monom.org> References: <1345126336-20755-1-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]:32922 "EHLO hotel311.server4you.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752992Ab2HPOMU (ORCPT ); Thu, 16 Aug 2012 10:12:20 -0400 In-Reply-To: <1345126336-20755-1-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 | 8 +++++++- net/core/sock.c | 5 +++++ net/sched/cls_cgroup.c | 5 +++++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h index 401672c..5b91220 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 @@ -24,6 +25,11 @@ struct cgroup_cls_state u32 classid; }; +#if IS_ENABLED(CONFIG_NET_CLS_CGROUP) +extern struct static_key cgroup_cls_enabled; +#define clscg_enabled static_key_false(&cgroup_cls_enabled) +#endif + extern void sock_update_classid(struct sock *sk); #if IS_BUILTIN(CONFIG_NET_CLS_CGROUP) @@ -52,7 +58,7 @@ 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..8d3a400 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_ENABLED(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..f40086b 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -44,12 +44,17 @@ static struct cgroup_subsys_state *cgrp_create(struct cgroup *cgrp) if (cgrp->parent) cs->classid = cgrp_cls_state(cgrp->parent)->classid; + else if (!clscg_enabled) + static_key_slow_inc(&cgroup_cls_enabled); return &cs->css; } static void cgrp_destroy(struct cgroup *cgrp) { + if (!cgrp->parent && clscg_enabled) + static_key_slow_dec(&cgroup_cls_enabled); + kfree(cgrp_cls_state(cgrp)); } -- 1.7.12.rc1.16.g05a20c8