score: Fix a release/cancel job race condition

Split up the potential thread priority change in the scheduler
release/cancel job operation.  Protect the rate monotonic period state
with a dedicated SMP lock.  This avoids a race condition during
_Rate_monotonic_Timeout() while _Rate_monotonic_Cancel() is called on
another processor.

2 files changed, 11 insertions, 6 deletions

diff --git a/cpukit/rtems/include/rtems/rtems/ratemon.h b/cpukit/rtems/include/rtems/rtems/ratemon.h
index 3203eab394..a2df13f025 100644
--- a/cpukit/rtems/include/rtems/rtems/ratemon.h
+++ b/cpukit/rtems/include/rtems/rtems/ratemon.h
@@ -194,6 +194,11 @@ typedef struct {
   /** This field is the object management portion of a Period instance. */
   Objects_Control                         Object;
 
+  /**
+   * @brief Protects the rate monotonic period state.
+   */
+  ISR_LOCK_MEMBER(                        Lock )
+
   /** This is the timer used to provide the unblocking mechanism. */
   Watchdog_Control                        Timer;
 
diff --git a/cpukit/rtems/include/rtems/rtems/ratemonimpl.h b/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
index 9963cab612..b6b3ffd404 100644
--- a/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
+++ b/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
@@ -69,19 +69,19 @@ RTEMS_INLINE_ROUTINE Rate_monotonic_Control *_Rate_monotonic_Allocate( void )
 }
 
 RTEMS_INLINE_ROUTINE void _Rate_monotonic_Acquire_critical(
-  Thread_Control   *the_thread,
-  ISR_lock_Context *lock_context
+  Rate_monotonic_Control *the_period,
+  ISR_lock_Context       *lock_context
 )
 {
-  _Thread_Wait_acquire_default_critical( the_thread, lock_context );
+  _ISR_lock_Acquire( &the_period->Lock, lock_context );
 }
 
 RTEMS_INLINE_ROUTINE void _Rate_monotonic_Release(
-  Thread_Control   *the_thread,
-  ISR_lock_Context *lock_context
+  Rate_monotonic_Control *the_period,
+  ISR_lock_Context       *lock_context
 )
 {
-  _Thread_Wait_release_default( the_thread, lock_context );
+  _ISR_lock_Release_and_ISR_enable( &the_period->Lock, lock_context );
 }
 
 RTEMS_INLINE_ROUTINE Rate_monotonic_Control *_Rate_monotonic_Get(