[kvm-unit-tests PATCH 3/4] arm/arm64: Track whether thread_info has been initialized

[Nikos Nikoleris <nikos.nikoleris@arm.com>]

Introduce a new flag in the thread_info to track whether a thread_info
struct is initialized yet or not.

Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
---
 lib/arm/asm/thread_info.h | 1 +
 lib/arm/processor.c       | 5 +++--
 lib/arm64/processor.c     | 5 +++--
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/lib/arm/asm/thread_info.h b/lib/arm/asm/thread_info.h
index eaa7258..926c2a3 100644
--- a/lib/arm/asm/thread_info.h
+++ b/lib/arm/asm/thread_info.h
@@ -45,6 +45,7 @@ static inline void *thread_stack_alloc(void)
 }
 
 #define TIF_USER_MODE		(1U << 0)
+#define TIF_VALID		(1U << 1)
 
 struct thread_info {
 	int cpu;
diff --git a/lib/arm/processor.c b/lib/arm/processor.c
index a2d39a4..702fbc3 100644
--- a/lib/arm/processor.c
+++ b/lib/arm/processor.c
@@ -119,7 +119,7 @@ void thread_info_init(struct thread_info *ti, unsigned int flags)
 {
 	memset(ti, 0, sizeof(struct thread_info));
 	ti->cpu = mpidr_to_cpu(get_mpidr());
-	ti->flags = flags;
+	ti->flags = flags | TIF_VALID;
 }
 
 void start_usr(void (*func)(void *arg), void *arg, unsigned long sp_usr)
@@ -143,7 +143,8 @@ void start_usr(void (*func)(void *arg), void *arg, unsigned long sp_usr)
 
 bool is_user(void)
 {
-	return current_thread_info()->flags & TIF_USER_MODE;
+	struct thread_info *ti = current_thread_info();
+	return (ti->flags & TIF_VALID) && (ti->flags & TIF_USER_MODE);
 }
 
 bool __mmu_enabled(void)
diff --git a/lib/arm64/processor.c b/lib/arm64/processor.c
index ef55862..231d71e 100644
--- a/lib/arm64/processor.c
+++ b/lib/arm64/processor.c
@@ -227,7 +227,7 @@ static void __thread_info_init(struct thread_info *ti, unsigned int flags)
 {
 	memset(ti, 0, sizeof(struct thread_info));
 	ti->cpu = mpidr_to_cpu(get_mpidr());
-	ti->flags = flags;
+	ti->flags = flags | TIF_VALID;
 }
 
 void thread_info_init(struct thread_info *ti, unsigned int flags)
@@ -255,7 +255,8 @@ void start_usr(void (*func)(void *arg), void *arg, unsigned long sp_usr)
 
 bool is_user(void)
 {
-	return current_thread_info()->flags & TIF_USER_MODE;
+	struct thread_info *ti = current_thread_info();
+	return (ti->flags & TIF_VALID) && (ti->flags & TIF_USER_MODE);
 }
 
 bool __mmu_enabled(void)
-- 
2.25.1