kernel: add syscalls for k_object_access APIs

These modify kernel object metadata and are intended to be callable from
user threads, need a privilege elevation for these to work.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

include/kernel.h

@@ -215,7 +215,33 @@ int _k_object_validate(void *obj, enum k_objects otype, int init);
  * @param object Address of the kernel object
  */
 void _k_object_init(void *obj);
+#else
+static inline int _k_object_validate(void *obj, enum k_objects otype, int init)
+{
+	ARG_UNUSED(obj);
+	ARG_UNUSED(otype);
+	ARG_UNUSED(init);
 
+	return 0;
+}
+
+static inline void _k_object_init(void *obj)
+{
+	ARG_UNUSED(obj);
+}
+
+static inline void _impl_k_object_access_grant(void *object,
+					       struct k_thread *thread)
+{
+	ARG_UNUSED(object);
+	ARG_UNUSED(thread);
+}
+
+static inline void _impl_k_object_access_all_grant(void *object)
+{
+	ARG_UNUSED(object);
+}
+#endif /* !CONFIG_USERSPACE */
 
 /**
  * grant a thread access to a kernel object
@@ -227,7 +253,7 @@ void _k_object_init(void *obj);
  * @param object Address of kernel object
  * @param thread Thread to grant access to the object
  */
-void k_object_access_grant(void *object, struct k_thread *thread);
+__syscall void k_object_access_grant(void *object, struct k_thread *thread);
 
 
 /**
@@ -244,29 +270,7 @@ void k_object_access_grant(void *object, struct k_thread *thread);
  *
  * @param object Address of kernel object
  */
-void k_object_access_all_grant(void *object);
-
-#else
-static inline int _k_object_validate(void *obj, enum k_objects otype, int init)
-{
-	ARG_UNUSED(obj);
-	ARG_UNUSED(otype);
-	ARG_UNUSED(init);
-
-	return 0;
-}
-
-static inline void _k_object_init(void *obj)
-{
-	ARG_UNUSED(obj);
-}
-
-static inline void k_object_access_grant(void *object, struct k_thread *thread)
-{
-	ARG_UNUSED(object);
-	ARG_UNUSED(thread);
-}
-#endif /* CONFIG_USERSPACE */
+__syscall void k_object_access_all_grant(void *object);
 
 /* timeouts */
 

kernel/Makefile

@@ -37,4 +37,4 @@ lib-$(CONFIG_SYS_CLOCK_EXISTS) += timer.o
 lib-$(CONFIG_ATOMIC_OPERATIONS_C) += atomic_c.o
 lib-$(CONFIG_POLL) += poll.o
 lib-$(CONFIG_PTHREAD_IPC) += pthread.o
-lib-$(CONFIG_USERSPACE) += userspace.o mem_domain.o
+lib-$(CONFIG_USERSPACE) += userspace.o userspace_handler.o mem_domain.o

kernel/userspace.c

@@ -174,7 +174,7 @@ static struct _k_object *access_check(void *object)
 	return ko;
 }
 
-void k_object_access_grant(void *object, struct k_thread *thread)
+void _impl_k_object_access_grant(void *object, struct k_thread *thread)
 {
 	struct _k_object *ko = access_check(object);
 
@@ -183,7 +183,7 @@ void k_object_access_grant(void *object, struct k_thread *thread)
 	}
 }
 
-void k_object_access_all_grant(void *object)
+void _impl_k_object_access_all_grant(void *object)
 {
 	struct _k_object *ko = access_check(object);
 

kernel/userspace_handler.c

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2017 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <kernel.h>
+#include <syscall_handler.h>
+
+/* 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.
+ */
+
+u32_t _handler_k_object_access_grant(u32_t object, u32_t thread, u32_t arg3,
+				     u32_t arg4, u32_t arg5, u32_t arg6,
+				     void *ssf)
+{
+	_SYSCALL_ARG2;
+
+	_SYSCALL_IS_OBJ(thread, K_OBJ_THREAD, 0, ssf);
+	_impl_k_object_access_grant((void *)object, (struct k_thread *)thread);
+	return 0;
+}
+
+u32_t _handler_k_object_access_all_grant(u32_t object, u32_t arg2, u32_t arg3,
+					 u32_t arg4, u32_t arg5, u32_t arg6,
+					 void *ssf)
+{
+	_SYSCALL_ARG1;
+
+	_impl_k_object_access_all_grant((void *)object);
+	return 0;
+}