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-rw-r--r--fs/namespace.c6
-rw-r--r--fs/proc/proc_net.c4
-rw-r--r--fs/proc_namespace.c8
-rw-r--r--include/linux/nsproxy.h16
-rw-r--r--ipc/namespace.c6
-rw-r--r--kernel/nsproxy.c15
-rw-r--r--kernel/utsname.c6
-rw-r--r--net/core/net_namespace.c10
8 files changed, 31 insertions, 40 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 182bc41..7187d01 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2972,13 +2972,13 @@ static void *mntns_get(struct task_struct *task)
struct mnt_namespace *ns = NULL;
struct nsproxy *nsproxy;
- rcu_read_lock();
- nsproxy = task_nsproxy(task);
+ task_lock(task);
+ nsproxy = task->nsproxy;
if (nsproxy) {
ns = nsproxy->mnt_ns;
get_mnt_ns(ns);
}
- rcu_read_unlock();
+ task_unlock(task);
return ns;
}
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index 4677bb7..a63af3e 100644
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -113,9 +113,11 @@ static struct net *get_proc_task_net(struct inode *dir)
rcu_read_lock();
task = pid_task(proc_pid(dir), PIDTYPE_PID);
if (task != NULL) {
- ns = task_nsproxy(task);
+ task_lock(task);
+ ns = task->nsproxy;
if (ns != NULL)
net = get_net(ns->net_ns);
+ task_unlock(task);
}
rcu_read_unlock();
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 1a81373..73ca174 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -232,17 +232,15 @@ static int mounts_open_common(struct inode *inode, struct file *file,
if (!task)
goto err;
- rcu_read_lock();
- nsp = task_nsproxy(task);
+ task_lock(task);
+ nsp = task->nsproxy;
if (!nsp || !nsp->mnt_ns) {
- rcu_read_unlock();
+ task_unlock(task);
put_task_struct(task);
goto err;
}
ns = nsp->mnt_ns;
get_mnt_ns(ns);
- rcu_read_unlock();
- task_lock(task);
if (!task->fs) {
task_unlock(task);
put_task_struct(task);
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
index b4ec59d..35fa08f 100644
--- a/include/linux/nsproxy.h
+++ b/include/linux/nsproxy.h
@@ -40,32 +40,28 @@ extern struct nsproxy init_nsproxy;
* the namespaces access rules are:
*
* 1. only current task is allowed to change tsk->nsproxy pointer or
- * any pointer on the nsproxy itself
+ * any pointer on the nsproxy itself. Current must hold the task_lock
+ * when changing tsk->nsproxy.
*
* 2. when accessing (i.e. reading) current task's namespaces - no
* precautions should be taken - just dereference the pointers
*
* 3. the access to other task namespaces is performed like this
- * rcu_read_lock();
- * nsproxy = task_nsproxy(tsk);
+ * task_lock(task);
+ * nsproxy = task->nsproxy;
* if (nsproxy != NULL) {
* / *
* * work with the namespaces here
* * e.g. get the reference on one of them
* * /
* } / *
- * * NULL task_nsproxy() means that this task is
+ * * NULL task->nsproxy means that this task is
* * almost dead (zombie)
* * /
- * rcu_read_unlock();
+ * task_unlock(task);
*
*/
-static inline struct nsproxy *task_nsproxy(struct task_struct *tsk)
-{
- return rcu_dereference(tsk->nsproxy);
-}
-
int copy_namespaces(unsigned long flags, struct task_struct *tsk);
void exit_task_namespaces(struct task_struct *tsk);
void switch_task_namespaces(struct task_struct *tsk, struct nsproxy *new);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 59451c1..b54468e 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -154,11 +154,11 @@ static void *ipcns_get(struct task_struct *task)
struct ipc_namespace *ns = NULL;
struct nsproxy *nsproxy;
- rcu_read_lock();
- nsproxy = task_nsproxy(task);
+ task_lock(task);
+ nsproxy = task->nsproxy;
if (nsproxy)
ns = get_ipc_ns(nsproxy->ipc_ns);
- rcu_read_unlock();
+ task_unlock(task);
return ns;
}
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 8e78110..ef42d0a 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -204,20 +204,13 @@ void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
might_sleep();
+ task_lock(p);
ns = p->nsproxy;
+ p->nsproxy = new;
+ task_unlock(p);
- rcu_assign_pointer(p->nsproxy, new);
-
- if (ns && atomic_dec_and_test(&ns->count)) {
- /*
- * wait for others to get what they want from this nsproxy.
- *
- * cannot release this nsproxy via the call_rcu() since
- * put_mnt_ns() will want to sleep
- */
- synchronize_rcu();
+ if (ns && atomic_dec_and_test(&ns->count))
free_nsproxy(ns);
- }
}
void exit_task_namespaces(struct task_struct *p)
diff --git a/kernel/utsname.c b/kernel/utsname.c
index fd39312..883aaaa 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -93,13 +93,13 @@ static void *utsns_get(struct task_struct *task)
struct uts_namespace *ns = NULL;
struct nsproxy *nsproxy;
- rcu_read_lock();
- nsproxy = task_nsproxy(task);
+ task_lock(task);
+ nsproxy = task->nsproxy;
if (nsproxy) {
ns = nsproxy->uts_ns;
get_uts_ns(ns);
}
- rcu_read_unlock();
+ task_unlock(task);
return ns;
}
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 85b6269..7c6b51a 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -373,9 +373,11 @@ struct net *get_net_ns_by_pid(pid_t pid)
tsk = find_task_by_vpid(pid);
if (tsk) {
struct nsproxy *nsproxy;
- nsproxy = task_nsproxy(tsk);
+ task_lock(tsk);
+ nsproxy = tsk->nsproxy;
if (nsproxy)
net = get_net(nsproxy->net_ns);
+ task_unlock(tsk);
}
rcu_read_unlock();
return net;
@@ -632,11 +634,11 @@ static void *netns_get(struct task_struct *task)
struct net *net = NULL;
struct nsproxy *nsproxy;
- rcu_read_lock();
- nsproxy = task_nsproxy(task);
+ task_lock(task);
+ nsproxy = task->nsproxy;
if (nsproxy)
net = get_net(nsproxy->net_ns);
- rcu_read_unlock();
+ task_unlock(task);
return net;
}
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