Index: lldb/trunk/packages/Python/lldbsuite/test/functionalities/gdb_remote_client/TestWriteMemory.py
===================================================================
--- lldb/trunk/packages/Python/lldbsuite/test/functionalities/gdb_remote_client/TestWriteMemory.py
+++ lldb/trunk/packages/Python/lldbsuite/test/functionalities/gdb_remote_client/TestWriteMemory.py
@@ -13,6 +13,14 @@
             def setBreakpoint(self, packet):
                 return "OK"
 
+    def setUp(self):
+        super(TestWriteMemory, self).setUp()
+        self._initial_platform = lldb.DBG.GetSelectedPlatform()
+
+    def tearDown(self):
+        lldb.DBG.SetSelectedPlatform(self._initial_platform)
+        super(TestWriteMemory, self).tearDown()
+
         self.server.responder = MyResponder()
         target = self.dbg.CreateTargetWithFileAndTargetTriple('', 'x86_64-pc-linux')
         process = self.connect(target)
Index: lldb/trunk/packages/Python/lldbsuite/test/functionalities/postmortem/elf-core/gcore/TestGCore.py
===================================================================
--- lldb/trunk/packages/Python/lldbsuite/test/functionalities/postmortem/elf-core/gcore/TestGCore.py
+++ lldb/trunk/packages/Python/lldbsuite/test/functionalities/postmortem/elf-core/gcore/TestGCore.py
@@ -15,7 +15,13 @@
     NO_DEBUG_INFO_TESTCASE = True
 
     mydir = TestBase.compute_mydir(__file__)
-    _initial_platform = lldb.DBG.GetSelectedPlatform()
+    def setUp(self):
+        super(GCoreTestCase, self).setUp()
+        self._initial_platform = lldb.DBG.GetSelectedPlatform()
+
+    def tearDown(self):
+        lldb.DBG.SetSelectedPlatform(self._initial_platform)
+        super(GCoreTestCase, self).tearDown()
 
     _i386_pid = 5586
     _x86_64_pid = 5669
@@ -47,4 +53,3 @@
             self.assertEqual(signal, 19)
 
         self.dbg.DeleteTarget(target)
-        lldb.DBG.SetSelectedPlatform(self._initial_platform)
Index: lldb/trunk/packages/Python/lldbsuite/test/functionalities/postmortem/elf-core/thread_crash/TestLinuxCoreThreads.py
===================================================================
--- lldb/trunk/packages/Python/lldbsuite/test/functionalities/postmortem/elf-core/thread_crash/TestLinuxCoreThreads.py
+++ lldb/trunk/packages/Python/lldbsuite/test/functionalities/postmortem/elf-core/thread_crash/TestLinuxCoreThreads.py
@@ -15,7 +15,14 @@
     NO_DEBUG_INFO_TESTCASE = True
 
     mydir = TestBase.compute_mydir(__file__)
-    _initial_platform = lldb.DBG.GetSelectedPlatform()
+
+    def setUp(self):
+        super(LinuxCoreThreadsTestCase, self).setUp()
+        self._initial_platform = lldb.DBG.GetSelectedPlatform()
+
+    def tearDown(self):
+        lldb.DBG.SetSelectedPlatform(self._initial_platform)
+        super(LinuxCoreThreadsTestCase, self).tearDown()
 
     _i386_pid = 5193
     _x86_64_pid = 5222
@@ -56,4 +63,3 @@
                 self.assertEqual(signal, 0)
 
         self.dbg.DeleteTarget(target)
-        lldb.DBG.SetSelectedPlatform(self._initial_platform)
Index: lldb/trunk/packages/Python/lldbsuite/test/tools/lldb-server/platform-process-connect/TestPlatformProcessConnect.py
===================================================================
--- lldb/trunk/packages/Python/lldbsuite/test/tools/lldb-server/platform-process-connect/TestPlatformProcessConnect.py
+++ lldb/trunk/packages/Python/lldbsuite/test/tools/lldb-server/platform-process-connect/TestPlatformProcessConnect.py
@@ -11,6 +11,14 @@
 class TestPlatformProcessConnect(gdbremote_testcase.GdbRemoteTestCaseBase):
     mydir = TestBase.compute_mydir(__file__)
 
+    def setUp(self):
+        super(TestPlatformProcessConnect, self).setUp()
+        self._initial_platform = lldb.DBG.GetSelectedPlatform()
+
+    def tearDown(self):
+        lldb.DBG.SetSelectedPlatform(self._initial_platform)
+        super(TestPlatformProcessConnect, self).tearDown()
+
     @llgs_test
     @no_debug_info_test
     @skipIf(remote=False)