[apple/xnu.git] / osfmk / kern / work_interval.c

/*
 * Copyright (c) 2017 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */


#include <sys/work_interval.h>

#include <kern/work_interval.h>

#include <kern/thread.h>
#include <kern/sched_prim.h>
#include <kern/machine.h>
#include <kern/thread_group.h>
#include <kern/ipc_kobject.h>
#include <kern/task.h>
#include <kern/coalition.h>
#include <kern/policy_internal.h>

#include <mach/kern_return.h>
#include <mach/notify.h>

#include <stdatomic.h>

/*
 * Work Interval structs
 *
 * This struct represents a thread group and/or work interval context
 * in a mechanism that is represented with a kobject.
 *
 * Every thread that has joined a WI has a +1 ref, and the port
 * has a +1 ref as well.
 *
 * TODO: groups need to have a 'is for WI' flag
 *      and they need a flag to create that says 'for WI'
 *      This would allow CLPC to avoid allocating WI support
 *      data unless it is needed
 *
 * TODO: Enforce not having more than one non-group joinable work
 *      interval per thread group.
 *      CLPC only wants to see one WI-notify callout per group.
 */

struct work_interval {
	uint64_t wi_id;
	_Atomic uint32_t wi_ref_count;
	uint32_t wi_create_flags;

	/* for debugging purposes only, does not hold a ref on port */
	ipc_port_t wi_port;

	/*
	 * holds uniqueid and version of creating process,
	 * used to permission-gate notify
	 * TODO: you'd think there would be a better way to do this
	 */
	uint64_t wi_creator_uniqueid;
	uint32_t wi_creator_pid;
	int wi_creator_pidversion;

};

static inline void
wi_retain(struct work_interval *work_interval)
{
	uint32_t old_count;
	old_count = atomic_fetch_add_explicit(&work_interval->wi_ref_count,
	                                      1, memory_order_relaxed);
	assert(old_count > 0);
}

static inline void
wi_release(struct work_interval *work_interval)
{
	uint32_t old_count;
	old_count = atomic_fetch_sub_explicit(&work_interval->wi_ref_count,
	                                      1, memory_order_relaxed);
	assert(old_count > 0);

	if (old_count == 1) {


		kfree(work_interval, sizeof(struct work_interval));
	}
}

/*
 * work_interval_port_alloc
 *
 * Description: Obtain a send right for the given work interval struct.
 *
 * Parameters:  work_interval - A work_interval struct
 *              Consumes a +1 ref count on work_interval, now owned by the port.
 *
 * Returns:     Port of type IKOT_WORK_INTERVAL with work_interval set as its kobject.
 *              Returned with a +1 send right and no-senders notification armed.
 *              Work interval struct reference is held by the port.
 */
static ipc_port_t
work_interval_port_alloc(struct work_interval *work_interval)
{
	ipc_port_t work_interval_port = ipc_port_alloc_kernel();

	if (work_interval_port == IP_NULL)
		panic("failed to allocate work interval port");

	assert(work_interval->wi_port == IP_NULL);

	ip_lock(work_interval_port);
	ipc_kobject_set_atomically(work_interval_port, (ipc_kobject_t)work_interval,
	                           IKOT_WORK_INTERVAL);

	ipc_port_t notify_port = ipc_port_make_sonce_locked(work_interval_port);
	ipc_port_t old_notify_port = IP_NULL;
	ipc_port_nsrequest(work_interval_port, 1, notify_port, &old_notify_port);
	/* port unlocked */

	assert(old_notify_port == IP_NULL);

	/* This is the only make-send that will happen on this port */
	ipc_port_t send_port = ipc_port_make_send(work_interval_port);
	assert(IP_VALID(send_port));

	work_interval->wi_port = work_interval_port;

	return send_port;
}

/*
 * work_interval_port_convert
 *
 * Called with port locked, returns reference to work interval
 * if indeed the port is a work interval kobject port
 */
static struct work_interval *
work_interval_port_convert_locked(ipc_port_t port)
{
	struct work_interval *work_interval = NULL;

	if (!IP_VALID(port))
		return NULL;

	if (!ip_active(port))
		return NULL;

	if (IKOT_WORK_INTERVAL != ip_kotype(port))
		return NULL;

	work_interval = (struct work_interval *)port->ip_kobject;

	wi_retain(work_interval);

	return work_interval;
}

/*
 * port_name_to_work_interval
 *
 * Description: Obtain a reference to the work_interval associated with a given port.
 *
 * Parameters:  name    A Mach port name to translate.
 *
 * Returns:     NULL    The given Mach port did not reference a work_interval.
 *              !NULL   The work_interval that is associated with the Mach port.
 */
static kern_return_t
port_name_to_work_interval(mach_port_name_t     name,
                           struct work_interval **work_interval)
{
	if (!MACH_PORT_VALID(name))
		return KERN_INVALID_NAME;

	ipc_port_t port = IPC_PORT_NULL;
	kern_return_t kr = KERN_SUCCESS;

	kr = ipc_port_translate_send(current_space(), name, &port);
	if (kr != KERN_SUCCESS)
		return kr;
	/* port is locked */

	assert(IP_VALID(port));

	struct work_interval *converted_work_interval;

	converted_work_interval = work_interval_port_convert_locked(port);

	/* the port is valid, but doesn't denote a work_interval */
	if (converted_work_interval == NULL)
		kr = KERN_INVALID_CAPABILITY;

	ip_unlock(port);

	if (kr == KERN_SUCCESS)
		*work_interval = converted_work_interval;

	return kr;

}


/*
 * work_interval_port_notify
 *
 * Description: Handle a no-senders notification for a work interval port.
 *              Destroys the port and releases its reference on the work interval.
 *
 * Parameters:  msg     A Mach no-senders notification message.
 *
 * Note: This assumes that there is only one create-right-from-work-interval point,
 *       if the ability to extract another send right after creation is added,
 *       this will have to change to handle make-send counts correctly.
 */
void
work_interval_port_notify(mach_msg_header_t *msg)
{
	mach_no_senders_notification_t *notification = (void *)msg;
	ipc_port_t port = notification->not_header.msgh_remote_port;
	struct work_interval *work_interval = NULL;

	if (!IP_VALID(port))
		panic("work_interval_port_notify(): invalid port");

	ip_lock(port);

	if (!ip_active(port))
		panic("work_interval_port_notify(): inactive port %p", port);

	if (ip_kotype(port) != IKOT_WORK_INTERVAL)
		panic("work_interval_port_notify(): not the right kobject: %p, %d\n",
		      port, ip_kotype(port));

	if (port->ip_mscount != notification->not_count)
		panic("work_interval_port_notify(): unexpected make-send count: %p, %d, %d",
		      port, port->ip_mscount, notification->not_count);

	if (port->ip_srights != 0)
		panic("work_interval_port_notify(): unexpected send right count: %p, %d",
		      port, port->ip_srights);

	work_interval = (struct work_interval *)port->ip_kobject;

	if (work_interval == NULL)
		panic("work_interval_port_notify(): missing kobject: %p", port);

	ipc_kobject_set_atomically(port, IKO_NULL, IKOT_NONE);

	work_interval->wi_port = MACH_PORT_NULL;

	ip_unlock(port);

	ipc_port_dealloc_kernel(port);
	wi_release(work_interval);
}

/*
 * Change thread's bound work interval to the passed-in work interval
 * Consumes +1 ref on work_interval
 *
 * May also pass NULL to un-set work_interval on the thread
 *
 * Will deallocate any old work interval on the thread
 */
static void
thread_set_work_interval(thread_t thread,
                         struct work_interval *work_interval)
{
	assert(thread == current_thread());

	struct work_interval *old_th_wi = thread->th_work_interval;

	/* transfer +1 ref to thread */
	thread->th_work_interval = work_interval;


	if (old_th_wi != NULL)
		wi_release(old_th_wi);
}

void
work_interval_thread_terminate(thread_t thread)
{
	if (thread->th_work_interval != NULL)
		thread_set_work_interval(thread, NULL);
}


kern_return_t
kern_work_interval_notify(thread_t thread, struct kern_work_interval_args* kwi_args)
{
	assert(thread == current_thread());
	assert(kwi_args->work_interval_id != 0);

	struct work_interval *work_interval = thread->th_work_interval;

	if (work_interval == NULL ||
	    work_interval->wi_id != kwi_args->work_interval_id) {
		/* This thread must have adopted the work interval to be able to notify */
		return (KERN_INVALID_ARGUMENT);
	}

	task_t notifying_task = current_task();

	if (work_interval->wi_creator_uniqueid   != get_task_uniqueid(notifying_task) ||
	    work_interval->wi_creator_pidversion != get_task_version(notifying_task)) {
		/* Only the creating task can do a notify */
		return (KERN_INVALID_ARGUMENT);
	}

	spl_t s = splsched();


	uint64_t urgency_param1, urgency_param2;
	kwi_args->urgency = thread_get_urgency(thread, &urgency_param1, &urgency_param2);

	splx(s);

	/* called without interrupts disabled */
	machine_work_interval_notify(thread, kwi_args);

	return (KERN_SUCCESS);
}

/* Start at 1, 0 is not a valid work interval ID */
static _Atomic uint64_t unique_work_interval_id = 1;

kern_return_t
kern_work_interval_create(thread_t thread,
                          struct kern_work_interval_create_args *create_params)
{
	assert(thread == current_thread());

	if (thread->th_work_interval != NULL) {
		/* already assigned a work interval */
		return (KERN_FAILURE);
	}

	struct work_interval *work_interval = kalloc(sizeof(*work_interval));

	if (work_interval == NULL)
		panic("failed to allocate work_interval");

	bzero(work_interval, sizeof(*work_interval));

	uint64_t old_value = atomic_fetch_add_explicit(&unique_work_interval_id, 1,
	                                               memory_order_relaxed);

	uint64_t work_interval_id = old_value + 1;

	uint32_t create_flags = create_params->wica_create_flags;

	task_t creating_task = current_task();
	if ((create_flags & WORK_INTERVAL_TYPE_MASK) == WORK_INTERVAL_TYPE_CA_CLIENT) {
		/*
		 * CA_CLIENT work intervals do not create new thread groups
		 * and are non-joinable.
		 * There can only be one CA_CLIENT work interval (created by UIKit)
		 * per each application task
		 */
		if (create_flags & (WORK_INTERVAL_FLAG_JOINABLE | WORK_INTERVAL_FLAG_GROUP))
			return (KERN_FAILURE);
		if (!task_is_app(creating_task))
			return (KERN_NOT_SUPPORTED);
		if (task_set_ca_client_wi(creating_task, true) == false)
			return (KERN_FAILURE);
	}

	*work_interval = (struct work_interval) {
		.wi_id                  = work_interval_id,
		.wi_ref_count           = 1,
		.wi_create_flags        = create_flags,
		.wi_creator_pid         = pid_from_task(creating_task),
		.wi_creator_uniqueid    = get_task_uniqueid(creating_task),
		.wi_creator_pidversion  = get_task_version(creating_task),
	};


	if (create_flags & WORK_INTERVAL_FLAG_JOINABLE) {
		/* work_interval has a +1 ref, moves to the port */
		ipc_port_t port = work_interval_port_alloc(work_interval);
		mach_port_name_t name = MACH_PORT_NULL;

		name = ipc_port_copyout_send(port, current_space());

		if (!MACH_PORT_VALID(name)) {
			/*
			 * copyout failed (port is already deallocated)
			 * Because of the port-destroyed magic,
			 * the work interval is already deallocated too.
			 */
			return KERN_RESOURCE_SHORTAGE;
		}

		create_params->wica_port = name;
	} else {
		/* work_interval has a +1 ref, moves to the thread */
		thread_set_work_interval(thread, work_interval);
		create_params->wica_port = MACH_PORT_NULL;
	}

	create_params->wica_id = work_interval_id;
	return KERN_SUCCESS;
}


kern_return_t
kern_work_interval_destroy(thread_t thread, uint64_t work_interval_id)
{
	if (work_interval_id == 0)
		return KERN_INVALID_ARGUMENT;

	if (thread->th_work_interval == NULL ||
	    thread->th_work_interval->wi_id != work_interval_id) {
		/* work ID isn't valid or doesn't match joined work interval ID */
		return (KERN_INVALID_ARGUMENT);
	}

	thread_set_work_interval(thread, NULL);

	return KERN_SUCCESS;
}

kern_return_t
kern_work_interval_join(thread_t            thread,
                        mach_port_name_t    port_name)
{
	struct work_interval *work_interval = NULL;
	kern_return_t kr;

	if (port_name == MACH_PORT_NULL) {
		/* 'Un-join' the current work interval */
		thread_set_work_interval(thread, NULL);
		return KERN_SUCCESS;
	}

	kr = port_name_to_work_interval(port_name, &work_interval);
	if (kr != KERN_SUCCESS)
		return kr;
	/* work_interval has a +1 ref */

	assert(work_interval != NULL);

	thread_set_work_interval(thread, work_interval);

	/* ref was consumed by passing it to the thread */

	return KERN_SUCCESS;
}
Commit	Line	Data
5ba3f43e A	1	/*
	2	* Copyright (c) 2017 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28
	29
	30	#include <sys/work_interval.h>
	31
	32	#include <kern/work_interval.h>
	33
	34	#include <kern/thread.h>
	35	#include <kern/sched_prim.h>
	36	#include <kern/machine.h>
	37	#include <kern/thread_group.h>
	38	#include <kern/ipc_kobject.h>
	39	#include <kern/task.h>
a39ff7e2 A	40	#include <kern/coalition.h>
a39ff7e2 A	41	#include <kern/policy_internal.h>
5ba3f43e A	42
	43	#include <mach/kern_return.h>
	44	#include <mach/notify.h>
	45
	46	#include <stdatomic.h>
	47
	48	/*
	49	* Work Interval structs
	50	*
	51	* This struct represents a thread group and/or work interval context
	52	* in a mechanism that is represented with a kobject.
	53	*
	54	* Every thread that has joined a WI has a +1 ref, and the port
	55	* has a +1 ref as well.
	56	*
	57	* TODO: groups need to have a 'is for WI' flag
	58	* and they need a flag to create that says 'for WI'
	59	* This would allow CLPC to avoid allocating WI support
	60	* data unless it is needed
	61	*
	62	* TODO: Enforce not having more than one non-group joinable work
	63	* interval per thread group.
	64	* CLPC only wants to see one WI-notify callout per group.
	65	*/
	66
	67	struct work_interval {
	68	uint64_t wi_id;
	69	_Atomic uint32_t wi_ref_count;
	70	uint32_t wi_create_flags;
	71
	72	/* for debugging purposes only, does not hold a ref on port */
	73	ipc_port_t wi_port;
	74
	75	/*
	76	* holds uniqueid and version of creating process,
	77	* used to permission-gate notify
	78	* TODO: you'd think there would be a better way to do this
	79	*/
	80	uint64_t wi_creator_uniqueid;
	81	uint32_t wi_creator_pid;
	82	int wi_creator_pidversion;
	83
	84	};
	85
	86	static inline void
	87	wi_retain(struct work_interval *work_interval)
	88	{
	89	uint32_t old_count;
	90	old_count = atomic_fetch_add_explicit(&work_interval->wi_ref_count,
	91	1, memory_order_relaxed);
	92	assert(old_count > 0);
	93	}
	94
	95	static inline void
	96	wi_release(struct work_interval *work_interval)
	97	{
	98	uint32_t old_count;
	99	old_count = atomic_fetch_sub_explicit(&work_interval->wi_ref_count,
	100	1, memory_order_relaxed);
	101	assert(old_count > 0);
	102
	103	if (old_count == 1) {
	104
	105
106	kfree(work_interval, sizeof(struct work_interval));
107	}
108	}
109
110	/*
111	* work_interval_port_alloc
112	*
113	* Description: Obtain a send right for the given work interval struct.
114	*
115	* Parameters: work_interval - A work_interval struct
116	* Consumes a +1 ref count on work_interval, now owned by the port.
117	*
118	* Returns: Port of type IKOT_WORK_INTERVAL with work_interval set as its kobject.
119	* Returned with a +1 send right and no-senders notification armed.
120	* Work interval struct reference is held by the port.
121	*/
122	static ipc_port_t
123	work_interval_port_alloc(struct work_interval *work_interval)
124	{
125	ipc_port_t work_interval_port = ipc_port_alloc_kernel();
126
127	if (work_interval_port == IP_NULL)
128	panic("failed to allocate work interval port");
129
130	assert(work_interval->wi_port == IP_NULL);
131
132	ip_lock(work_interval_port);
133	ipc_kobject_set_atomically(work_interval_port, (ipc_kobject_t)work_interval,
134	IKOT_WORK_INTERVAL);
135
136	ipc_port_t notify_port = ipc_port_make_sonce_locked(work_interval_port);
137	ipc_port_t old_notify_port = IP_NULL;
138	ipc_port_nsrequest(work_interval_port, 1, notify_port, &old_notify_port);
139	/* port unlocked */
140
141	assert(old_notify_port == IP_NULL);
142
143	/* This is the only make-send that will happen on this port */
144	ipc_port_t send_port = ipc_port_make_send(work_interval_port);
145	assert(IP_VALID(send_port));
146
147	work_interval->wi_port = work_interval_port;
148
149	return send_port;
150	}
151
152	/*
153	* work_interval_port_convert
154	*
155	* Called with port locked, returns reference to work interval
156	* if indeed the port is a work interval kobject port
157	*/
158	static struct work_interval *
159	work_interval_port_convert_locked(ipc_port_t port)
160	{
161	struct work_interval *work_interval = NULL;
162
163	if (!IP_VALID(port))
164	return NULL;
165
166	if (!ip_active(port))
167	return NULL;
168
169	if (IKOT_WORK_INTERVAL != ip_kotype(port))
170	return NULL;
171
172	work_interval = (struct work_interval *)port->ip_kobject;
173
174	wi_retain(work_interval);
175
176	return work_interval;
177	}
178
179	/*
180	* port_name_to_work_interval
181	*
182	* Description: Obtain a reference to the work_interval associated with a given port.
183	*
184	* Parameters: name A Mach port name to translate.
185	*
186	* Returns: NULL The given Mach port did not reference a work_interval.
187	* !NULL The work_interval that is associated with the Mach port.
188	*/
189	static kern_return_t
190	port_name_to_work_interval(mach_port_name_t name,
191	struct work_interval **work_interval)
192	{
193	if (!MACH_PORT_VALID(name))
194	return KERN_INVALID_NAME;
195
196	ipc_port_t port = IPC_PORT_NULL;
197	kern_return_t kr = KERN_SUCCESS;
198
199	kr = ipc_port_translate_send(current_space(), name, &port);
200	if (kr != KERN_SUCCESS)
201	return kr;
202	/* port is locked */
203
204	assert(IP_VALID(port));
205
206	struct work_interval *converted_work_interval;
207
208	converted_work_interval = work_interval_port_convert_locked(port);
209
210	/* the port is valid, but doesn't denote a work_interval */
211	if (converted_work_interval == NULL)
212	kr = KERN_INVALID_CAPABILITY;
213
214	ip_unlock(port);
215
216	if (kr == KERN_SUCCESS)
217	*work_interval = converted_work_interval;
218
219	return kr;
220
221	}
222
223
224	/*
225	* work_interval_port_notify
226	*
227	* Description: Handle a no-senders notification for a work interval port.
228	* Destroys the port and releases its reference on the work interval.
229	*
230	* Parameters: msg A Mach no-senders notification message.
231	*
232	* Note: This assumes that there is only one create-right-from-work-interval point,
233	* if the ability to extract another send right after creation is added,
234	* this will have to change to handle make-send counts correctly.
235	*/
236	void
237	work_interval_port_notify(mach_msg_header_t *msg)
238	{
239	mach_no_senders_notification_t notification = (void )msg;
240	ipc_port_t port = notification->not_header.msgh_remote_port;
241	struct work_interval *work_interval = NULL;
242
243	if (!IP_VALID(port))
244	panic("work_interval_port_notify(): invalid port");
245
246	ip_lock(port);
247
248	if (!ip_active(port))
249	panic("work_interval_port_notify(): inactive port %p", port);
250
251	if (ip_kotype(port) != IKOT_WORK_INTERVAL)
252	panic("work_interval_port_notify(): not the right kobject: %p, %d\n",
253	port, ip_kotype(port));
254
255	if (port->ip_mscount != notification->not_count)
256	panic("work_interval_port_notify(): unexpected make-send count: %p, %d, %d",
257	port, port->ip_mscount, notification->not_count);
258
259	if (port->ip_srights != 0)
260	panic("work_interval_port_notify(): unexpected send right count: %p, %d",
261	port, port->ip_srights);
262
263	work_interval = (struct work_interval *)port->ip_kobject;
264
265	if (work_interval == NULL)
266	panic("work_interval_port_notify(): missing kobject: %p", port);
267
268	ipc_kobject_set_atomically(port, IKO_NULL, IKOT_NONE);
269
270	work_interval->wi_port = MACH_PORT_NULL;
271
272	ip_unlock(port);
273
274	ipc_port_dealloc_kernel(port);
275	wi_release(work_interval);
276	}
277
278	/*
279	* Change thread's bound work interval to the passed-in work interval
280	* Consumes +1 ref on work_interval
281	*
282	* May also pass NULL to un-set work_interval on the thread
283	*
284	* Will deallocate any old work interval on the thread
285	*/
286	static void
287	thread_set_work_interval(thread_t thread,
288	struct work_interval *work_interval)
289	{
290	assert(thread == current_thread());
291
292	struct work_interval *old_th_wi = thread->th_work_interval;
293
294	/* transfer +1 ref to thread */
295	thread->th_work_interval = work_interval;
296
297
298	if (old_th_wi != NULL)
299	wi_release(old_th_wi);
300	}
301
302	void
303	work_interval_thread_terminate(thread_t thread)
304	{
305	if (thread->th_work_interval != NULL)
306	thread_set_work_interval(thread, NULL);
307	}
308
309
310
311	kern_return_t
312	kern_work_interval_notify(thread_t thread, struct kern_work_interval_args* kwi_args)
313	{
314	assert(thread == current_thread());
315	assert(kwi_args->work_interval_id != 0);
316
317	struct work_interval *work_interval = thread->th_work_interval;
318
319	if (work_interval == NULL \|\|
320	work_interval->wi_id != kwi_args->work_interval_id) {
321	/* This thread must have adopted the work interval to be able to notify */
322	return (KERN_INVALID_ARGUMENT);
323	}
324
325	task_t notifying_task = current_task();
326
327	if (work_interval->wi_creator_uniqueid != get_task_uniqueid(notifying_task) \|\|
328	work_interval->wi_creator_pidversion != get_task_version(notifying_task)) {
329	/* Only the creating task can do a notify */
330	return (KERN_INVALID_ARGUMENT);
331	}
332
333	spl_t s = splsched();
334
335
336	uint64_t urgency_param1, urgency_param2;
337	kwi_args->urgency = thread_get_urgency(thread, &urgency_param1, &urgency_param2);
338
339	splx(s);
340
341	/* called without interrupts disabled */
342	machine_work_interval_notify(thread, kwi_args);
343
344	return (KERN_SUCCESS);
345	}
346
347	/* Start at 1, 0 is not a valid work interval ID */
348	static _Atomic uint64_t unique_work_interval_id = 1;
349
350	kern_return_t
351	kern_work_interval_create(thread_t thread,
352	struct kern_work_interval_create_args *create_params)
353	{
354	assert(thread == current_thread());
355
356	if (thread->th_work_interval != NULL) {
357	/* already assigned a work interval */
358	return (KERN_FAILURE);
359	}
360
361	struct work_interval work_interval = kalloc(sizeof(work_interval));
362
363	if (work_interval == NULL)
364	panic("failed to allocate work_interval");
365
366	bzero(work_interval, sizeof(*work_interval));
367
368	uint64_t old_value = atomic_fetch_add_explicit(&unique_work_interval_id, 1,
369	memory_order_relaxed);
370
371	uint64_t work_interval_id = old_value + 1;
372
373	uint32_t create_flags = create_params->wica_create_flags;
374
375	task_t creating_task = current_task();
a39ff7e2 A	376	if ((create_flags & WORK_INTERVAL_TYPE_MASK) == WORK_INTERVAL_TYPE_CA_CLIENT) {
	377	/*
	378	* CA_CLIENT work intervals do not create new thread groups
	379	* and are non-joinable.
	380	* There can only be one CA_CLIENT work interval (created by UIKit)
	381	* per each application task
	382	*/
	383	if (create_flags & (WORK_INTERVAL_FLAG_JOINABLE \| WORK_INTERVAL_FLAG_GROUP))
	384	return (KERN_FAILURE);
	385	if (!task_is_app(creating_task))
	386	return (KERN_NOT_SUPPORTED);
	387	if (task_set_ca_client_wi(creating_task, true) == false)
	388	return (KERN_FAILURE);
	389	}
5ba3f43e A	390
	391	*work_interval = (struct work_interval) {
	392	.wi_id = work_interval_id,
	393	.wi_ref_count = 1,
	394	.wi_create_flags = create_flags,
	395	.wi_creator_pid = pid_from_task(creating_task),
	396	.wi_creator_uniqueid = get_task_uniqueid(creating_task),
	397	.wi_creator_pidversion = get_task_version(creating_task),
	398	};
	399
	400
	401	if (create_flags & WORK_INTERVAL_FLAG_JOINABLE) {
	402	/* work_interval has a +1 ref, moves to the port */
	403	ipc_port_t port = work_interval_port_alloc(work_interval);
	404	mach_port_name_t name = MACH_PORT_NULL;
	405
	406	name = ipc_port_copyout_send(port, current_space());
	407
	408	if (!MACH_PORT_VALID(name)) {
	409	/*
	410	* copyout failed (port is already deallocated)
	411	* Because of the port-destroyed magic,
	412	* the work interval is already deallocated too.
	413	*/
	414	return KERN_RESOURCE_SHORTAGE;
	415	}
	416
	417	create_params->wica_port = name;
	418	} else {
	419	/* work_interval has a +1 ref, moves to the thread */
	420	thread_set_work_interval(thread, work_interval);
	421	create_params->wica_port = MACH_PORT_NULL;
	422	}
	423
	424	create_params->wica_id = work_interval_id;
5ba3f43e A	425	return KERN_SUCCESS;
	426	}
	427
a39ff7e2	428
5ba3f43e	429	kern_return_t
a39ff7e2	430	kern_work_interval_destroy(thread_t thread, uint64_t work_interval_id)
5ba3f43e A	431	{
	432	if (work_interval_id == 0)
	433	return KERN_INVALID_ARGUMENT;
	434
	435	if (thread->th_work_interval == NULL \|\|
	436	thread->th_work_interval->wi_id != work_interval_id) {
	437	/* work ID isn't valid or doesn't match joined work interval ID */
	438	return (KERN_INVALID_ARGUMENT);
	439	}
	440
	441	thread_set_work_interval(thread, NULL);
	442
	443	return KERN_SUCCESS;
	444	}
	445
	446	kern_return_t
	447	kern_work_interval_join(thread_t thread,
	448	mach_port_name_t port_name)
	449	{
	450	struct work_interval *work_interval = NULL;
	451	kern_return_t kr;
	452
	453	if (port_name == MACH_PORT_NULL) {
	454	/* 'Un-join' the current work interval */
	455	thread_set_work_interval(thread, NULL);
	456	return KERN_SUCCESS;
	457	}
	458
	459	kr = port_name_to_work_interval(port_name, &work_interval);
	460	if (kr != KERN_SUCCESS)
	461	return kr;
	462	/* work_interval has a +1 ref */
	463
	464	assert(work_interval != NULL);
	465
	466	thread_set_work_interval(thread, work_interval);
	467
	468	/* ref was consumed by passing it to the thread */
	469
	470	return KERN_SUCCESS;
	471	}