diff options
Diffstat (limited to 'include/linux/nsproxy.h')
-rw-r--r-- | include/linux/nsproxy.h | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h index b4ec59d159ac..35fa08fd7739 100644 --- a/include/linux/nsproxy.h +++ b/include/linux/nsproxy.h | |||
@@ -40,32 +40,28 @@ extern struct nsproxy init_nsproxy; | |||
40 | * the namespaces access rules are: | 40 | * the namespaces access rules are: |
41 | * | 41 | * |
42 | * 1. only current task is allowed to change tsk->nsproxy pointer or | 42 | * 1. only current task is allowed to change tsk->nsproxy pointer or |
43 | * any pointer on the nsproxy itself | 43 | * any pointer on the nsproxy itself. Current must hold the task_lock |
44 | * when changing tsk->nsproxy. | ||
44 | * | 45 | * |
45 | * 2. when accessing (i.e. reading) current task's namespaces - no | 46 | * 2. when accessing (i.e. reading) current task's namespaces - no |
46 | * precautions should be taken - just dereference the pointers | 47 | * precautions should be taken - just dereference the pointers |
47 | * | 48 | * |
48 | * 3. the access to other task namespaces is performed like this | 49 | * 3. the access to other task namespaces is performed like this |
49 | * rcu_read_lock(); | 50 | * task_lock(task); |
50 | * nsproxy = task_nsproxy(tsk); | 51 | * nsproxy = task->nsproxy; |
51 | * if (nsproxy != NULL) { | 52 | * if (nsproxy != NULL) { |
52 | * / * | 53 | * / * |
53 | * * work with the namespaces here | 54 | * * work with the namespaces here |
54 | * * e.g. get the reference on one of them | 55 | * * e.g. get the reference on one of them |
55 | * * / | 56 | * * / |
56 | * } / * | 57 | * } / * |
57 | * * NULL task_nsproxy() means that this task is | 58 | * * NULL task->nsproxy means that this task is |
58 | * * almost dead (zombie) | 59 | * * almost dead (zombie) |
59 | * * / | 60 | * * / |
60 | * rcu_read_unlock(); | 61 | * task_unlock(task); |
61 | * | 62 | * |
62 | */ | 63 | */ |
63 | 64 | ||
64 | static inline struct nsproxy *task_nsproxy(struct task_struct *tsk) | ||
65 | { | ||
66 | return rcu_dereference(tsk->nsproxy); | ||
67 | } | ||
68 | |||
69 | int copy_namespaces(unsigned long flags, struct task_struct *tsk); | 65 | int copy_namespaces(unsigned long flags, struct task_struct *tsk); |
70 | void exit_task_namespaces(struct task_struct *tsk); | 66 | void exit_task_namespaces(struct task_struct *tsk); |
71 | void switch_task_namespaces(struct task_struct *tsk, struct nsproxy *new); | 67 | void switch_task_namespaces(struct task_struct *tsk, struct nsproxy *new); |