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authorJ. Bruce Fields <bfields@redhat.com>2020-05-06 12:09:34 -0400
committerJ. Bruce Fields <bfields@redhat.com>2020-05-08 21:23:10 -0400
commit52782c92ac85c4e393eb4a903a62e6c24afa633f (patch)
treeff14ce08344fd48a5d6228527bbd949c012a13d4 /kernel/kthread.c
parent31fb4bf545e230f2c7db7e64cf012c67a8d374df (diff)
kthread: save thread function
It's handy to keep the kthread_fn just as a unique cookie to identify classes of kthreads. E.g. if you can verify that a given task is running your thread_fn, then you may know what sort of type kthread_data points to. We'll use this in nfsd to pass some information into the vfs. Note it will need kthread_data() exported too. Original-patch-by: Tejun Heo <tj@kernel.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'kernel/kthread.c')
-rw-r--r--kernel/kthread.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/kernel/kthread.c b/kernel/kthread.c
index bfbfa481be3a..b84fc7eec035 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -46,6 +46,7 @@ struct kthread_create_info
struct kthread {
unsigned long flags;
unsigned int cpu;
+ int (*threadfn)(void *);
void *data;
struct completion parked;
struct completion exited;
@@ -153,6 +154,20 @@ bool kthread_freezable_should_stop(bool *was_frozen)
EXPORT_SYMBOL_GPL(kthread_freezable_should_stop);
/**
+ * kthread_func - return the function specified on kthread creation
+ * @task: kthread task in question
+ *
+ * Returns NULL if the task is not a kthread.
+ */
+void *kthread_func(struct task_struct *task)
+{
+ if (task->flags & PF_KTHREAD)
+ return to_kthread(task)->threadfn;
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(kthread_func);
+
+/**
* kthread_data - return data value specified on kthread creation
* @task: kthread task in question
*
@@ -164,6 +179,7 @@ void *kthread_data(struct task_struct *task)
{
return to_kthread(task)->data;
}
+EXPORT_SYMBOL_GPL(kthread_data);
/**
* kthread_probe_data - speculative version of kthread_data()
@@ -244,6 +260,7 @@ static int kthread(void *_create)
do_exit(-ENOMEM);
}
+ self->threadfn = threadfn;
self->data = data;
init_completion(&self->exited);
init_completion(&self->parked);