diff options
| -rw-r--r-- | include/linux/kthread.h | 1 | ||||
| -rw-r--r-- | kernel/kthread.c | 19 |
2 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 8d816646f766..7dcef3317689 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -43,6 +43,7 @@ bool kthread_should_stop(void); bool kthread_should_park(void); bool kthread_freezable_should_stop(bool *was_frozen); void *kthread_data(struct task_struct *k); +void *probe_kthread_data(struct task_struct *k); int kthread_park(struct task_struct *k); void kthread_unpark(struct task_struct *k); void kthread_parkme(void); diff --git a/kernel/kthread.c b/kernel/kthread.c index 16d8ddd268b1..760e86df8c20 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -17,6 +17,7 @@ #include <linux/slab.h> #include <linux/freezer.h> #include <linux/ptrace.h> +#include <linux/uaccess.h> #include <trace/events/sched.h> static DEFINE_SPINLOCK(kthread_create_lock); @@ -135,6 +136,24 @@ void *kthread_data(struct task_struct *task) return to_kthread(task)->data; } +/** + * probe_kthread_data - speculative version of kthread_data() + * @task: possible kthread task in question + * + * @task could be a kthread task. Return the data value specified when it + * was created if accessible. If @task isn't a kthread task or its data is + * inaccessible for any reason, %NULL is returned. This function requires + * that @task itself is safe to dereference. + */ +void *probe_kthread_data(struct task_struct *task) +{ + struct kthread *kthread = to_kthread(task); + void *data = NULL; + + probe_kernel_read(&data, &kthread->data, sizeof(data)); + return data; +} + static void __kthread_parkme(struct kthread *self) { __set_current_state(TASK_PARKED); |