From 1f7c5c88ca384baa312a0714c6e93174605418a7 Mon Sep 17 00:00:00 2001
From: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date: Fri, 25 Sep 2015 21:31:00 +0200
Subject: score: Fix atomic compare exchange

---
 cpukit/score/cpu/sparc/sparcv8-atomic.c         |  8 ++++++--
 cpukit/score/include/rtems/score/cpustdatomic.h | 18 +++++++++++++++---
 2 files changed, 21 insertions(+), 5 deletions(-)

(limited to 'cpukit')

diff --git a/cpukit/score/cpu/sparc/sparcv8-atomic.c b/cpukit/score/cpu/sparc/sparcv8-atomic.c
index b1c4f23c88..2b3bdbc451 100644
--- a/cpukit/score/cpu/sparc/sparcv8-atomic.c
+++ b/cpukit/score/cpu/sparc/sparcv8-atomic.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2014-2015 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -118,12 +118,16 @@ bool __atomic_compare_exchange_4(
 {
   bool equal;
   ISR_Level level;
+  uint32_t actual;
 
   level = _SPARCV8_Acquire_the_one_lock();
 
-  equal = *mem == *expected;
+  actual = *mem;
+  equal = ( actual == *expected );
   if ( equal ) {
     *mem = desired;
+  } else {
+    *expected = actual;
   }
 
   _SPARCV8_Release_the_one_lock( level );
diff --git a/cpukit/score/include/rtems/score/cpustdatomic.h b/cpukit/score/include/rtems/score/cpustdatomic.h
index 2696e3afbc..c66dd7eb34 100644
--- a/cpukit/score/include/rtems/score/cpustdatomic.h
+++ b/cpukit/score/include/rtems/score/cpustdatomic.h
@@ -577,13 +577,17 @@ static inline bool _CPU_atomic_Compare_exchange_uint( CPU_atomic_Uint *obj, unsi
 #else
   bool success;
   ISR_Level level;
+  unsigned int actual;
 
   (void) succ;
   (void) fail;
   _ISR_Disable( level );
-  success = *obj == *expected;
+  actual = *obj;
+  success = ( actual == *expected );
   if ( success ) {
     *obj = desired;
+  } else {
+    *expected = actual;
   }
   _ISR_Enable( level );
 
@@ -600,13 +604,17 @@ static inline bool _CPU_atomic_Compare_exchange_ulong( CPU_atomic_Ulong *obj, un
 #else
   bool success;
   ISR_Level level;
+  unsigned long actual;
 
   (void) succ;
   (void) fail;
   _ISR_Disable( level );
-  success = *obj == *expected;
+  actual = *obj;
+  success = ( actual == *expected );
   if ( success ) {
     *obj = desired;
+  } else {
+    *expected = actual;
   }
   _ISR_Enable( level );
 
@@ -623,13 +631,17 @@ static inline bool _CPU_atomic_Compare_exchange_ptr( CPU_atomic_Pointer *obj, vo
 #else
   bool success;
   ISR_Level level;
+  uintptr_t actual;
 
   (void) succ;
   (void) fail;
   _ISR_Disable( level );
-  success = *obj == (uintptr_t) *expected;
+  actual = *obj;
+  success = ( actual == (uintptr_t) *expected );
   if ( success ) {
     *obj = (uintptr_t) desired;
+  } else {
+    *expected = (void *) actual;
   }
   _ISR_Enable( level );
 
-- 
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