[PATCH v1 3/5] cgroup: Protect access to task_cls_classid() when built as module
From: Daniel Wagner <hidden>
Date: 2012-08-17 14:58:12
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
Possibly related (same subject, not in this thread)
- 2012-08-23 · Re: [PATCH v1 3/5] cgroup: Protect access to task_cls_classid() when built as module · Daniel Wagner <hidden>
- 2012-08-23 · Re: [PATCH v1 3/5] cgroup: Protect access to task_cls_classid() when built as module · Glauber Costa <hidden>
- 2012-08-21 · Re: [PATCH v1 3/5] cgroup: Protect access to task_cls_classid() when built as module · Glauber Costa <hidden>
- 2012-08-20 · Re: [PATCH v1 3/5] cgroup: Protect access to task_cls_classid() when built as module · Neil Horman <hidden>
- 2012-08-20 · Re: [PATCH v1 3/5] cgroup: Protect access to task_cls_classid() when built as module · Glauber Costa <hidden>
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-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org> Cc: Gao feng <redacted> Cc: Jamal Hadi Salim <jhs-jkUAjuhPggJWk0Htik3J/w@public.gmane.org> Cc: John Fastabend <redacted> Cc: Li Zefan <redacted> Cc: Neil Horman <redacted> Cc: Tejun Heo <redacted> 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 <linux/cgroup.h> #include <linux/hardirq.h> #include <linux/rcupdate.h> +#include <linux/jump_label.h> #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