Commit 3772f771 authored by Andrew Boie's avatar Andrew Boie Committed by Anas Nashif
Browse files

k_poll: expose to user mode 



k_poll is now accessible from user mode. A memory allocation takes place
from the caller's resource pool to copy the provided poll_events
array; this can be large enough to make allocating it on the stack
not preferable.

k_poll_signal are now proper kernel objects. Two APIs have been added,
one to reset the signaled state and one to check the current signaled
state and result value.

Signed-off-by: default avatarAndrew Boie <andrew.p.boie@intel.com>
parent 8345e5eb

include/kernel.h

+38 −7
Original line number Diff line number Diff line
@@ -4178,6 +4178,9 @@ extern void k_poll_event_init(struct k_poll_event *event, u32_t type, 
 * Before being reused for another call to k_poll(), the user has to reset the

 * state field to K_POLL_STATE_NOT_READY.

 *

 * When called from user mode, a temporary memory allocation is required from

 * the caller's resource pool.

 *

 * @param events An array of pointers to events to be polled for.

 * @param num_events The number of events in the array.

 * @param timeout Waiting period for an event to be ready (in milliseconds),
@@ -4186,9 +4189,11 @@ extern void k_poll_event_init(struct k_poll_event *event, u32_t type, 
 * @retval 0 One or more events are ready.

 * @retval -EAGAIN Waiting period timed out.

 * @retval -EINTR Poller thread has been interrupted.

 * @retval -ENOMEM Thread resource pool insufficient memory (user mode only)

 * @retval -EINVAL Bad parameters (user mode only)

 */



extern int k_poll(struct k_poll_event *events, int num_events,

__syscall int k_poll(struct k_poll_event *events, int num_events,

		     s32_t timeout);



/**
@@ -4201,7 +4206,32 @@ extern int k_poll(struct k_poll_event *events, int num_events, 
 * @return N/A

 */



extern void k_poll_signal_init(struct k_poll_signal *signal);

__syscall void k_poll_signal_init(struct k_poll_signal *signal);



/*

 * @brief Reset a poll signal object's state to unsignaled.

 *

 * @param signal A poll signal object

 */

__syscall void k_poll_signal_reset(struct k_poll_signal *signal);



static inline void _impl_k_poll_signal_reset(struct k_poll_signal *signal)

{

	signal->signaled = 0;

}



/**

 * @brief Fetch the signaled state and resylt value of a poll signal

 *

 * @param signal A poll signal object

 * @param signaled An integer buffer which will be written nonzero if the

 *		   object was signaled

 * @param result An integer destination buffer which will be written with the

 *		   result value if the object was signaed, or an undefined

 *		   value if it was not.

 */

__syscall void k_poll_signal_check(struct k_poll_signal *signal,

				   unsigned int *signaled, int *result);



/**

 * @brief Signal a poll signal object.
@@ -4211,9 +4241,10 @@ extern void k_poll_signal_init(struct k_poll_signal *signal); 
 * made ready to run. A @a result value can be specified.

 *

 * The poll signal contains a 'signaled' field that, when set by

 * k_poll_signal(), stays set until the user sets it back to 0. It thus has to

 * be reset by the user before being passed again to k_poll() or k_poll() will

 * consider it being signaled, and will return immediately.

 * k_poll_signal(), stays set until the user sets it back to 0 with

 * k_poll_signal_reset(). It thus has to be reset by the user before being

 * passed again to k_poll() or k_poll() will consider it being signaled, and

 * will return immediately.

 *

 * @param signal A poll signal.

 * @param result The value to store in the result field of the signal.
@@ -4222,7 +4253,7 @@ extern void k_poll_signal_init(struct k_poll_signal *signal); 
 * @retval -EAGAIN The polling thread's timeout is in the process of expiring.

 */



extern int k_poll_signal(struct k_poll_signal *signal, int result);

__syscall int k_poll_signal(struct k_poll_signal *signal, int result);



/**

 * @internal

kernel/poll.c

+119 −3
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <kernel_internal.h>

#include <wait_q.h>

#include <ksched.h>

#include <syscall_handler.h>

#include <misc/slist.h>

#include <misc/dlist.h>

#include <misc/__assert.h>
@@ -189,7 +190,7 @@ static inline void set_event_ready(struct k_poll_event *event, u32_t state) 
	event->state |= state;

}



int k_poll(struct k_poll_event *events, int num_events, s32_t timeout)

int _impl_k_poll(struct k_poll_event *events, int num_events, s32_t timeout)

{

	__ASSERT(!_is_in_isr(), "");

	__ASSERT(events, "NULL events\n");
@@ -263,6 +264,80 @@ int k_poll(struct k_poll_event *events, int num_events, s32_t timeout) 
	return swap_rc;

}



#ifdef CONFIG_USERSPACE

Z_SYSCALL_HANDLER(k_poll, events, num_events, timeout)

{

	int ret, key;

	struct k_poll_event *events_copy = NULL;

	unsigned int bounds;



	/* Validate the events buffer and make a copy of it in an

	 * allocated kernel-side buffer.

	 */

	if (Z_SYSCALL_VERIFY(num_events > 0)) {

		ret = -EINVAL;

		goto out;

	}

	if (Z_SYSCALL_VERIFY_MSG(

		!__builtin_umul_overflow(num_events,

					sizeof(struct k_poll_event),

					&bounds), "num_events too large")) {

		ret = -EINVAL;

		goto out;

	}

	events_copy = z_thread_malloc(bounds);

	if (!events_copy) {

		ret = -ENOMEM;

		goto out;

	}



	key = irq_lock();

	if (Z_SYSCALL_MEMORY_WRITE(events, bounds)) {

		irq_unlock(key);

		goto oops_free;

	}

	memcpy(events_copy, (void *)events, bounds);

	irq_unlock(key);



	/* Validate what's inside events_copy */

	for (int i = 0; i < num_events; i++) {

		struct k_poll_event *e = &events_copy[i];



		if (Z_SYSCALL_VERIFY(e->mode == K_POLL_MODE_NOTIFY_ONLY)) {

			ret = -EINVAL;

			goto out_free;

		}



		switch (e->type) {

		case K_POLL_TYPE_IGNORE:

			break;

		case K_POLL_TYPE_SIGNAL:

			Z_OOPS(Z_SYSCALL_OBJ(e->signal, K_OBJ_POLL_SIGNAL));

			break;

		case K_POLL_TYPE_SEM_AVAILABLE:

			Z_OOPS(Z_SYSCALL_OBJ(e->sem, K_OBJ_SEM));

			break;

		case K_POLL_TYPE_DATA_AVAILABLE:

			Z_OOPS(Z_SYSCALL_OBJ(e->queue, K_OBJ_QUEUE));

			break;

		default:

			ret = -EINVAL;

			goto out_free;

		}

	}



	ret = k_poll(events_copy, num_events, timeout);

	memcpy((void *)events, events_copy, bounds);

out_free:

	k_free(events_copy);

out:

	return ret;

oops_free:

	k_free(events_copy);

	Z_OOPS(1);

}

#endif



/* must be called with interrupts locked */

static int signal_poll_event(struct k_poll_event *event, u32_t state)

{
@@ -309,14 +384,44 @@ void _handle_obj_poll_events(sys_dlist_t *events, u32_t state) 
	}

}



void k_poll_signal_init(struct k_poll_signal *signal)

void _impl_k_poll_signal_init(struct k_poll_signal *signal)

{

	sys_dlist_init(&signal->poll_events);

	signal->signaled = 0;

	/* signal->result is left unitialized */

	_k_object_init(signal);

}



#ifdef CONFIG_USERSPACE

Z_SYSCALL_HANDLER(k_poll_signal_init, signal)

{

	Z_OOPS(Z_SYSCALL_OBJ_INIT(signal, K_OBJ_POLL_SIGNAL));

	_impl_k_poll_signal_init((struct k_poll_signal *)signal);

	return 0;

}

#endif



void _impl_k_poll_signal_check(struct k_poll_signal *signal,

			       unsigned int *signaled, int *result)

{

	*signaled = signal->signaled;

	*result = signal->result;

}



int k_poll_signal(struct k_poll_signal *signal, int result)

#ifdef CONFIG_USERSPACE

Z_SYSCALL_HANDLER(k_poll_signal_check, signal, signaled, result)

{

	Z_OOPS(Z_SYSCALL_OBJ(signal, K_OBJ_POLL_SIGNAL));

	Z_OOPS(Z_SYSCALL_MEMORY_WRITE(signaled, sizeof(unsigned int)));

	Z_OOPS(Z_SYSCALL_MEMORY_WRITE(result, sizeof(int)));



	_impl_k_poll_signal_check((struct k_poll_signal *)signal,

				  (unsigned int *)signaled, (int *)result);

	return 0;

}

#endif



int _impl_k_poll_signal(struct k_poll_signal *signal, int result)

{

	unsigned int key = irq_lock();

	struct k_poll_event *poll_event;
@@ -335,3 +440,14 @@ int k_poll_signal(struct k_poll_signal *signal, int result) 
	_reschedule(key);

	return rc;

}



#ifdef CONFIG_USERSPACE

Z_SYSCALL_HANDLER(k_poll_signal, signal, result)

{

	Z_OOPS(Z_SYSCALL_OBJ(signal, K_OBJ_POLL_SIGNAL));

	return _impl_k_poll_signal((struct k_poll_signal *)signal, result);

}

Z_SYSCALL_HANDLER1_SIMPLE_VOID(k_poll_signal_reset, K_OBJ_POLL_SIGNAL,

			       struct k_poll_signal *);

#endif

scripts/gen_kobject_list.py

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ kobjects = [ 
    "k_mutex",

    "k_pipe",

    "k_queue",

    "k_poll_signal",

    "k_sem",

    "k_stack",

    "k_thread",

tests/kernel/poll/prj.conf

+1 −0
Original line number Diff line number Diff line 
CONFIG_ZTEST=y

CONFIG_POLL=y

CONFIG_DYNAMIC_OBJECTS=y

tests/kernel/poll/src/main.c

+8 −1
Original line number Diff line number Diff line
@@ -15,12 +15,19 @@ 
extern void test_poll_no_wait(void);

extern void test_poll_wait(void);

extern void test_poll_multi(void);

extern void test_poll_grant_access(void);



K_MEM_POOL_DEFINE(test_pool, 128, 128, 4, 4);



/*test case main entry*/

void test_main(void)

{

	test_poll_grant_access();



	k_thread_resource_pool_assign(k_current_get(), &test_pool);



	ztest_test_suite(poll_api,

			ztest_unit_test(test_poll_no_wait),

			ztest_user_unit_test(test_poll_no_wait),

			ztest_unit_test(test_poll_wait),

			ztest_unit_test(test_poll_multi));

	ztest_run_test_suite(poll_api);

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