Changeset 61935 in vbox for trunk/src

Timestamp:

Jun 29, 2016 1:51:13 PM (8 years ago)

Author:

vboxsync

Message:

MachineDebuggerImpl.cpp: VMR3Suspend will fail if the VM is already suspended! The intention was actually to put the pause in the caller code (terminateVmBySession), rather than here. But, for reliablity, let's keep it, but restrict it to only kick in when actually needed.

File:

• trunk/src/VBox/Main/src-client/MachineDebuggerImpl.cpp (modified) (2 diffs)

trunk/src/VBox/Main/src-client/MachineDebuggerImpl.cpp

@@ -1359 +1359 @@
     if (SUCCEEDED(hrc))
     {
-        /* Suspend the VM first or we risk deadlocks or inconsistent guest stacks. */
-        alock.release();
-        int vrc = VMR3Suspend(ptrVM.rawUVM(), VMSUSPENDREASON_USER);
-        alock.acquire(); 
+        /*
+         * There is currently a problem with the windows diggers and SMP, where
+         * guest driver memory is being read from CPU zero in order to ensure that
+         * we've got a consisten virtual memory view.  If one of the other CPUs
+         * initiates a rendezvous while we're unwinding the stack and trying to
+         * read guest driver memory, we will deadlock.
+         *
+         * So, check the VM state and maybe suspend the VM before we continue.
+         */
+        int  vrc     = VINF_SUCCESS;
+        bool fPaused = false;
+        if (aCpuId != 0)
+        {
+            VMSTATE enmVmState = VMR3GetStateU(ptrVM.rawUVM());
+            if (   enmVmState == VMSTATE_RUNNING
+                || enmVmState == VMSTATE_RUNNING_LS
+                || enmVmState == VMSTATE_RUNNING_FT)
+            {
+                alock.release();
+                vrc = VMR3Suspend(ptrVM.rawUVM(), VMSUSPENDREASON_USER);
+                alock.acquire();
+                fPaused = RT_SUCCESS(vrc);
+            }
+        }
         if (RT_SUCCESS(vrc))
         {
             PCDBGFSTACKFRAME pFirstFrame;
-
             vrc = DBGFR3StackWalkBegin(ptrVM.rawUVM(), aCpuId, DBGFCODETYPE_GUEST, &pFirstFrame);
             if (RT_SUCCESS(vrc))
@@ -1456 +1475 @@
                 hrc = setError(E_FAIL, tr("DBGFR3StackWalkBegin failed with %Rrc"), vrc);
 
-            alock.release();
-            VMR3Resume(ptrVM.rawUVM(), VMRESUMEREASON_USER);
-            alock.acquire();
+            /*
+             * Resume the VM if we suspended it.
+             */
+            if (fPaused)
+            {
+                alock.release();
+                VMR3Resume(ptrVM.rawUVM(), VMRESUMEREASON_USER);
+            }
         }
         else