[Lldb-commits] [lldb] r282632 - Add the ability for the task port to change when a process execs.

[Greg Clayton via lldb-commits]

Author: gclayton
Date: Wed Sep 28 16:07:34 2016
New Revision: 282632

URL: http://llvm.org/viewvc/llvm-project?rev=282632&view=rev
Log:
Add the ability for the task port to change when a process execs.

<rdar://problem/28476369>

Modified:
    lldb/trunk/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py
    lldb/trunk/tools/debugserver/source/MacOSX/MachException.cpp
    lldb/trunk/tools/debugserver/source/MacOSX/MachTask.h
    lldb/trunk/tools/debugserver/source/MacOSX/MachTask.mm

Modified: lldb/trunk/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py?rev=282632&r1=282631&r2=282632&view=diff
==============================================================================
--- lldb/trunk/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py (original)
+++ lldb/trunk/packages/Python/lldbsuite/test/functionalities/exec/TestExec.py Wed Sep 28 16:07:34 2016
@@ -27,7 +27,6 @@ class ExecTestCase(TestBase):
     mydir = TestBase.compute_mydir(__file__)
 
     @skipUnlessDarwin
-    @expectedFailureAll(oslist=["macosx"], bugnumber="rdar://28476369")
     def test(self):
         if self.getArchitecture() == 'x86_64':
             source = os.path.join(os.getcwd(), "main.cpp")

Modified: lldb/trunk/tools/debugserver/source/MacOSX/MachException.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/source/MacOSX/MachException.cpp?rev=282632&r1=282631&r2=282632&view=diff
==============================================================================
--- lldb/trunk/tools/debugserver/source/MacOSX/MachException.cpp (original)
+++ lldb/trunk/tools/debugserver/source/MacOSX/MachException.cpp Wed Sep 28 16:07:34 2016
@@ -106,15 +106,30 @@ catch_mach_exception_raise(mach_port_t e
                    (uint64_t)(exc_data_count > 0 ? exc_data[0] : 0xBADDBADD),
                    (uint64_t)(exc_data_count > 1 ? exc_data[1] : 0xBADDBADD));
   }
+  g_message->exc_type = 0;
+  g_message->exc_data.clear();
 
   if (task_port == g_message->task_port) {
     g_message->task_port = task_port;
     g_message->thread_port = thread_port;
     g_message->exc_type = exc_type;
-    g_message->exc_data.resize(exc_data_count);
-    ::memcpy(&g_message->exc_data[0], exc_data,
-             g_message->exc_data.size() * sizeof(mach_exception_data_type_t));
+    for (mach_msg_type_number_t i=0; i<exc_data_count; ++i)
+      g_message->exc_data.push_back(exc_data[i]);
     return KERN_SUCCESS;
+  } else if (!MachTask::IsValid(g_message->task_port)) {
+    // Our original exception port isn't valid anymore check for a SIGTRAP
+    if (exc_type == EXC_SOFTWARE && exc_data_count == 2 &&
+        exc_data[0] == EXC_SOFT_SIGNAL && exc_data[1] == SIGTRAP) {
+      // We got a SIGTRAP which indicates we might have exec'ed and possibly
+      // lost our old task port during the exec, so we just need to switch over
+      // to using this new task port
+      g_message->task_port = task_port;
+      g_message->thread_port = thread_port;
+      g_message->exc_type = exc_type;
+      for (mach_msg_type_number_t i=0; i<exc_data_count; ++i)
+        g_message->exc_data.push_back(exc_data[i]);
+      return KERN_SUCCESS;
+    }
   }
   return KERN_FAILURE;
 }

Modified: lldb/trunk/tools/debugserver/source/MacOSX/MachTask.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/source/MacOSX/MachTask.h?rev=282632&r1=282631&r2=282632&view=diff
==============================================================================
--- lldb/trunk/tools/debugserver/source/MacOSX/MachTask.h (original)
+++ lldb/trunk/tools/debugserver/source/MacOSX/MachTask.h Wed Sep 28 16:07:34 2016
@@ -82,6 +82,7 @@ public:
   bool IsValid() const;
   static bool IsValid(task_t task);
   static void *ExceptionThread(void *arg);
+  void TaskPortChanged(task_t task);
   task_t TaskPort() const { return m_task; }
   task_t TaskPortForProcessID(DNBError &err, bool force = false);
   static task_t TaskPortForProcessID(pid_t pid, DNBError &err,

Modified: lldb/trunk/tools/debugserver/source/MacOSX/MachTask.mm
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/tools/debugserver/source/MacOSX/MachTask.mm?rev=282632&r1=282631&r2=282632&view=diff
==============================================================================
--- lldb/trunk/tools/debugserver/source/MacOSX/MachTask.mm (original)
+++ lldb/trunk/tools/debugserver/source/MacOSX/MachTask.mm Wed Sep 28 16:07:34 2016
@@ -867,6 +867,16 @@ void *MachTask::ExceptionThread(void *ar
       // TODO: notify of error?
     } else {
       if (exception_message.CatchExceptionRaise(task)) {
+        if (exception_message.state.task_port != task) {
+          if (exception_message.state.IsValid()) {
+            // We exec'ed and our task port changed on us.
+            DNBLogThreadedIf(LOG_EXCEPTIONS,
+                             "task port changed from 0x%4.4x to 0x%4.4x",
+                             task, exception_message.state.task_port);
+            task = exception_message.state.task_port;
+            mach_task->TaskPortChanged(exception_message.state.task_port);
+          }
+        }
         ++num_exceptions_received;
         mach_proc->ExceptionMessageReceived(exception_message);
       }
@@ -984,3 +994,8 @@ nub_bool_t MachTask::DeallocateMemory(nu
 }
 
 nub_size_t MachTask::PageSize() { return m_vm_memory.PageSize(m_task); }
+
+void MachTask::TaskPortChanged(task_t task)
+{
+  m_task = task;
+}