ATLEDGE 201 Pointer returned may be null

Added a check for this null pointer.

Signed-off-by: Kevin Moloney <kevin.moloney@emutex.com>

Author: Kevin Moloney

system/libarc32_edu/framework/src/os/os.c

@@ -41,12 +41,17 @@ void * cfw_alloc(int size, OS_ERR_TYPE * err) {
     void * ptr;
     unsigned int flags = interrupt_lock();
     ptr = malloc(size+sizeof(void*));
-    (*(int*) ptr) = size;
+    if (ptr != NULL) {
+        (*(int*) ptr) = size;
 #ifdef TRACK_ALLOCS
-    alloc_count++;
+        alloc_count++;
 #endif
-    interrupt_unlock(flags);
-    return ptr;
+        interrupt_unlock(flags);
+        return ptr;
+    } else {
+        interrupt_unlock(flags);
+        return 0;
+    }
 }
 
 void cfw_free(void * ptr, OS_ERR_TYPE * err) {