From: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx>
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 <daniel.wagner@xxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Gao feng <gaofeng@xxxxxxxxxxxxxx>
Cc: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Cc: John Fastabend <john.r.fastabend@xxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: Neil Horman <nhorman@xxxxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: cgroups@xxxxxxxxxxxxxxx
---
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
--
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