Changeset 28705 in vbox

Timestamp:

Apr 25, 2010 12:39:42 PM (15 years ago)

Author:

vboxsync

Message:

AHCI: Fix race condition where a task could be used even if it is already active

File:

• trunk/src/VBox/Devices/Storage/DevAHCI.cpp (modified) (5 diffs)

trunk/src/VBox/Devices/Storage/DevAHCI.cpp

@@ -292 +292 @@
      * and the callback copies the data to the destination. */
     PFNAHCIPOSTPROCESS         pfnPostProcess;
+#ifdef RT_STRICT
+    /** Flag whether the task state is currently active - used for debugging */
+    volatile bool              fActive;
+#endif
 } AHCIPORTTASKSTATE;
 
@@ -4886 +4890 @@
         ASMAtomicOrU32(&pAhciPort->u32QueuedTasksFinished, (1 << pAhciPortTaskState->uTag));
 
+#ifdef RT_STRICT
+        bool fXchg = ASMAtomicCmpXchgBool(&pAhciPortTaskState->fActive, false, true);
+        AssertMsg(fXchg, ("Task is not active\n"));
+#endif
+
         if (!cOutstandingTasks)
-            ahciSendSDBFis(pAhciPort, pAhciPort->u32QueuedTasksFinished, pAhciPortTaskState, true);
+            ahciSendSDBFis(pAhciPort, 0, pAhciPortTaskState, true);
     }
     else
+    {
+#ifdef RT_STRICT
+        bool fXchg = ASMAtomicCmpXchgBool(&pAhciPortTaskState->fActive, false, true);
+        AssertMsg(fXchg, ("Task is not active\n"));
+#endif
+
         ahciSendD2HFis(pAhciPort, pAhciPortTaskState, pAhciPortTaskState->cmdFis, true);
+    }
 
     /* Add the task to the cache. */
@@ -5236 +5252 @@
         ahciLog(("%s: Processing command at slot %d\n", __FUNCTION__, pNotifierItem->iTask));
 
-        /* Check if there is already an allocated task struct in the cache.
+        /*
+         * Check if there is already an allocated task struct in the cache.
          * Allocate a new task otherwise.
          */
@@ -5248 +5265 @@
             pAhciPortTaskState = pAhciPort->aCachedTasks[pNotifierItem->iTask];
         }
+
+#ifdef RT_STRICT
+        bool fXchg = ASMAtomicCmpXchgBool(&pAhciPortTaskState->fActive, true, false);
+        AssertMsg(fXchg, ("Task is already active\n"));
+#endif
 
         /** Set current command slot */
@@ -5338 +5360 @@
         else
         {
+#ifdef RT_STRICT
+            bool fXchg = ASMAtomicCmpXchgBool(&pAhciPortTaskState->fActive, false, true);
+            AssertMsg(fXchg, ("Task is not active\n"));
+#endif
+
             /* There is nothing left to do. Notify the guest. */
             ahciSendD2HFis(pAhciPort, pAhciPortTaskState, &pAhciPortTaskState->cmdFis[0], true);