KTHREAD_IS_PARKED,
};
-#define __to_kthread(vfork) \
- container_of(vfork, struct kthread, exited)
+static inline void set_kthread_struct(void *kthread)
+{
+ /*
+ * We abuse ->set_child_tid to avoid the new member and because it
+ * can't be wrongly copied by copy_process(). We also rely on fact
+ * that the caller can't exec, so PF_KTHREAD can't be cleared.
+ */
+ current->set_child_tid = (__force void __user *)kthread;
+}
static inline struct kthread *to_kthread(struct task_struct *k)
{
- return __to_kthread(k->vfork_done);
+ WARN_ON(!(k->flags & PF_KTHREAD));
+ return (__force void *)k->set_child_tid;
}
-static struct kthread *to_live_kthread(struct task_struct *k)
+void free_kthread_struct(struct task_struct *k)
{
- struct completion *vfork = ACCESS_ONCE(k->vfork_done);
- if (likely(vfork) && try_get_task_stack(k))
- return __to_kthread(vfork);
- return NULL;
+ /*
+ * Can be NULL if this kthread was created by kernel_thread()
+ * or if kmalloc() in kthread() failed.
+ */
+ kfree(to_kthread(k));
}
/**
int (*threadfn)(void *data) = create->threadfn;
void *data = create->data;
struct completion *done;
- struct kthread self;
+ struct kthread *self;
int ret;
- self.flags = 0;
- self.data = data;
- init_completion(&self.exited);
- init_completion(&self.parked);
- current->vfork_done = &self.exited;
+ self = kmalloc(sizeof(*self), GFP_KERNEL);
+ set_kthread_struct(self);
/* If user was SIGKILLed, I release the structure. */
done = xchg(&create->done, NULL);
kfree(create);
do_exit(-EINTR);
}
+
+ if (!self) {
+ create->result = ERR_PTR(-ENOMEM);
+ complete(done);
+ do_exit(-ENOMEM);
+ }
+
+ self->flags = 0;
+ self->data = data;
+ init_completion(&self->exited);
+ init_completion(&self->parked);
+ current->vfork_done = &self->exited;
+
/* OK, tell user we're spawned, wait for stop or wakeup */
__set_current_state(TASK_UNINTERRUPTIBLE);
create->result = current;
schedule();
ret = -EINTR;
-
- if (!test_bit(KTHREAD_SHOULD_STOP, &self.flags)) {
- __kthread_parkme(&self);
+ if (!test_bit(KTHREAD_SHOULD_STOP, &self->flags)) {
+ __kthread_parkme(self);
ret = threadfn(data);
}
- /* we can't just return, we must preserve "self" on stack */
do_exit(ret);
}
}
}
-static struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
+static __printf(4, 0)
+struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
void *data, int node,
const char namefmt[],
va_list args)
return p;
}
-static void __kthread_unpark(struct task_struct *k, struct kthread *kthread)
+/**
+ * kthread_unpark - unpark a thread created by kthread_create().
+ * @k: thread created by kthread_create().
+ *
+ * Sets kthread_should_park() for @k to return false, wakes it, and
+ * waits for it to return. If the thread is marked percpu then its
+ * bound to the cpu again.
+ */
+void kthread_unpark(struct task_struct *k)
{
+ struct kthread *kthread = to_kthread(k);
+
clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
/*
* We clear the IS_PARKED bit here as we don't wait
wake_up_state(k, TASK_PARKED);
}
}
-
-/**
- * kthread_unpark - unpark a thread created by kthread_create().
- * @k: thread created by kthread_create().
- *
- * Sets kthread_should_park() for @k to return false, wakes it, and
- * waits for it to return. If the thread is marked percpu then its
- * bound to the cpu again.
- */
-void kthread_unpark(struct task_struct *k)
-{
- struct kthread *kthread = to_live_kthread(k);
-
- if (kthread) {
- __kthread_unpark(k, kthread);
- put_task_stack(k);
- }
-}
EXPORT_SYMBOL_GPL(kthread_unpark);
/**
*/
int kthread_park(struct task_struct *k)
{
- struct kthread *kthread = to_live_kthread(k);
- int ret = -ENOSYS;
-
- if (kthread) {
- if (!test_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
- set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
- if (k != current) {
- wake_up_process(k);
- wait_for_completion(&kthread->parked);
- }
+ struct kthread *kthread = to_kthread(k);
+
+ if (WARN_ON(k->flags & PF_EXITING))
+ return -ENOSYS;
+
+ if (!test_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
+ set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
+ if (k != current) {
+ wake_up_process(k);
+ wait_for_completion(&kthread->parked);
}
- put_task_stack(k);
- ret = 0;
}
- return ret;
+
+ return 0;
}
EXPORT_SYMBOL_GPL(kthread_park);
trace_sched_kthread_stop(k);
get_task_struct(k);
- kthread = to_live_kthread(k);
- if (kthread) {
- set_bit(KTHREAD_SHOULD_STOP, &kthread->flags);
- __kthread_unpark(k, kthread);
- wake_up_process(k);
- wait_for_completion(&kthread->exited);
- put_task_stack(k);
- }
+ kthread = to_kthread(k);
+ set_bit(KTHREAD_SHOULD_STOP, &kthread->flags);
+ kthread_unpark(k);
+ wake_up_process(k);
+ wait_for_completion(&kthread->exited);
ret = k->exit_code;
put_task_struct(k);
}
EXPORT_SYMBOL_GPL(kthread_worker_fn);
-static struct kthread_worker *
+static __printf(3, 0) struct kthread_worker *
__kthread_create_worker(int cpu, unsigned int flags,
const char namefmt[], va_list args)
{
struct kthread_worker *worker;
struct task_struct *task;
+ int node = -1;
worker = kzalloc(sizeof(*worker), GFP_KERNEL);
if (!worker)
kthread_init_worker(worker);
- if (cpu >= 0) {
- char name[TASK_COMM_LEN];
-
- /*
- * kthread_create_worker_on_cpu() allows to pass a generic
- * namefmt in compare with kthread_create_on_cpu. We need
- * to format it here.
- */
- vsnprintf(name, sizeof(name), namefmt, args);
- task = kthread_create_on_cpu(kthread_worker_fn, worker,
- cpu, name);
- } else {
- task = __kthread_create_on_node(kthread_worker_fn, worker,
- -1, namefmt, args);
- }
+ if (cpu >= 0)
+ node = cpu_to_node(cpu);
+ task = __kthread_create_on_node(kthread_worker_fn, worker,
+ node, namefmt, args);
if (IS_ERR(task))
goto fail_task;
+ if (cpu >= 0)
+ kthread_bind(task, cpu);
+
worker->flags = flags;
worker->task = task;
wake_up_process(task);
projects / mirror_ubuntu-bionic-kernel.git / blobdiff