From 5cfa5dc8dbdd7814d60de1662983772e06dc2a51 Mon Sep 17 00:00:00 2001
From: Andrew Boie <andrew.p.boie@intel.com>
Date: Wed, 30 Aug 2017 14:17:44 -0700
Subject: [PATCH] kernel: add K_USER flag and _is_thread_user()

Indicates that the thread is configured to run in user mode.
Delete stub function in userspace.c

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
---
 include/kernel.h        |  5 +++++
 kernel/include/ksched.h | 13 +++++++++++++
 kernel/userspace.c      |  8 +-------
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/include/kernel.h b/include/kernel.h
index 4508bbf20c5..a052b98df2b 100644
--- a/include/kernel.h
+++ b/include/kernel.h
@@ -427,6 +427,11 @@ extern void k_call_stacks_analyze(void);
 #define K_FP_REGS (1 << 1)
 #endif
 
+/* This thread has dropped from supervisor mode to user mode and consequently
+ * has additional restrictions
+ */
+#define K_USER (1 << 2)
+
 #ifdef CONFIG_X86
 /* x86 Bitmask definitions for threads user options */
 
diff --git a/kernel/include/ksched.h b/kernel/include/ksched.h
index 2b1bfb51ed1..fff2afe1682 100644
--- a/kernel/include/ksched.h
+++ b/kernel/include/ksched.h
@@ -516,4 +516,17 @@ static inline struct k_thread *_unpend_first_thread(_wait_q_t *wait_q)
 	return thread;
 }
 
+#ifdef CONFIG_USERSPACE
+/**
+ * Indicate whether the currently running thread has been configured to be
+ * a user thread.
+ *
+ * @return nonzero if the current thread is a user thread, regardless of what
+ *         mode the CPU is currently in
+ */
+static inline int _is_thread_user(void)
+{
+	return _current->base.user_options & K_USER;
+}
+#endif /* CONFIG_USERSPACE */
 #endif /* _ksched__h_ */
diff --git a/kernel/userspace.c b/kernel/userspace.c
index bc9f01f9d56..a5a5f81d066 100644
--- a/kernel/userspace.c
+++ b/kernel/userspace.c
@@ -10,6 +10,7 @@
 #include <misc/printk.h>
 #include <kernel_structs.h>
 #include <sys_io.h>
+#include <ksched.h>
 
 /**
  * Kernel object validation function
@@ -84,13 +85,6 @@ static int test_thread_perms(struct _k_object *ko)
 	return 1;
 }
 
-static int _is_thread_user(void)
-{
-	/* STUB */
-
-	return 0;
-}
-
 void k_object_grant_access(void *object, struct k_thread *thread)
 {
 	struct _k_object *ko = _k_object_find(object);