[PATCH v2 03/10] cgroup: net_cls: Protect access to task_cls_classid() when built as module
From: Daniel Wagner <hidden>
Date: 2012-08-24 14:01:49
Also in:
netdev
Subsystem:
networking [general], networking [sockets], tc subsystem, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds
From: Daniel Wagner <redacted> 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 <redacted> Cc: "David S. Miller" <davem@davemloft.net> Cc: Gao feng <redacted> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: John Fastabend <redacted> Cc: Li Zefan <redacted> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Tejun Heo <tj@kernel.org> 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 <linux/cgroup.h> #include <linux/hardirq.h> #include <linux/rcupdate.h> +#include <linux/jump_label.h> #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