userspace_handler.c

/*
 * Copyright (c) 2017 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <kernel.h>
#include <syscall_handler.h>

static struct _k_object *validate_any_object(void *obj)
{
	struct _k_object *ko;
	int ret;

	ko = _k_object_find(obj);

	/* This can be any kernel object and it doesn't have to be
	 * initialized
	 */
	ret = _k_object_validate(ko, K_OBJ_ANY, _OBJ_INIT_ANY);
	if (ret) {
#ifdef CONFIG_PRINTK
		_dump_object_error(ret, obj, ko, K_OBJ_ANY);
#endif
		return NULL;
	}

	return ko;
}

/* Normally these would be included in userspace.c, but the way
 * syscall_dispatch.c declares weak handlers results in build errors if these
 * are located in userspace.c. Just put in a separate file.
 *
 * To avoid double _k_object_find() lookups, we don't call the implementation
 * function, but call a level deeper.
 */
_SYSCALL_HANDLER(k_object_access_grant, object, thread)
{
	struct _k_object *ko;

	_SYSCALL_OBJ_INIT(thread, K_OBJ_THREAD);
	ko = validate_any_object((void *)object);
	_SYSCALL_VERIFY_MSG(ko, "object %p access denied", (void *)object);
	_thread_perms_set(ko, (struct k_thread *)thread);

	return 0;
}

_SYSCALL_HANDLER(k_object_access_revoke, object, thread)
{
	struct _k_object *ko;

	_SYSCALL_OBJ_INIT(thread, K_OBJ_THREAD);
	ko = validate_any_object((void *)object);
	_SYSCALL_VERIFY_MSG(ko, "object %p access denied", (void *)object);
	_thread_perms_clear(ko, (struct k_thread *)thread);

	return 0;
}