[rtems commit] score: Avoid NULL pointer access

[Sebastian Huber]

Module:    rtems
Branch:    master
Commit:    be3c257286ad870d8d1a64941cde53fd2d33a633
Changeset: http://git.rtems.org/rtems/commit/?id=be3c257286ad870d8d1a64941cde53fd2d33a633

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Thu Jun  5 11:17:26 2014 +0200

score: Avoid NULL pointer access

Check that the executing thread is not NULL in _Scheduler_Tick().  It
may be NULL in case the processor has an optional scheduler assigned and
the system was not able to start the processor.

---

 cpukit/score/include/rtems/score/schedulerimpl.h |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/cpukit/score/include/rtems/score/schedulerimpl.h b/cpukit/score/include/rtems/score/schedulerimpl.h
index e469214..f162ab3 100644
--- a/cpukit/score/include/rtems/score/schedulerimpl.h
+++ b/cpukit/score/include/rtems/score/schedulerimpl.h
@@ -282,9 +282,10 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Tick( void )
   for ( cpu_index = 0 ; cpu_index < cpu_count ; ++cpu_index ) {
     const Per_CPU_Control *cpu = _Per_CPU_Get_by_index( cpu_index );
     const Scheduler_Control *scheduler = _Scheduler_Get_by_CPU( cpu );
+    Thread_Control *executing = cpu->executing;
 
-    if ( scheduler != NULL ) {
-      ( *scheduler->Operations.tick )( scheduler, cpu->executing );
+    if ( scheduler != NULL && executing != NULL ) {
+      ( *scheduler->Operations.tick )( scheduler, executing );
     }
   }
 }