[ros-diffs] [weiden] 14268: fixed a few race conditions during thread/process termination leading to dead-locks

fixed a few race conditions during thread/process termination leading to
dead-locks
Modified: trunk/reactos/ntoskrnl/include/internal/ps.h
Modified: trunk/reactos/ntoskrnl/ps/create.c
Modified: trunk/reactos/ntoskrnl/ps/kill.c
  _____  

Modified: trunk/reactos/ntoskrnl/include/internal/ps.h
--- trunk/reactos/ntoskrnl/include/internal/ps.h	2005-03-22
17:17:02 UTC (rev 14267)
+++ trunk/reactos/ntoskrnl/include/internal/ps.h	2005-03-22
17:32:15 UTC (rev 14268)
@@ -428,7 +428,6 @@

    */
   MADDRESS_SPACE        AddressSpace;
   LIST_ENTRY            ProcessListEntry;
-  FAST_MUTEX            TebLock;
   PVOID                 TebBlock;
   PVOID                 TebLastAllocated;
 };
  _____  

Modified: trunk/reactos/ntoskrnl/ps/create.c
--- trunk/reactos/ntoskrnl/ps/create.c	2005-03-22 17:17:02 UTC (rev
14267)
+++ trunk/reactos/ntoskrnl/ps/create.c	2005-03-22 17:32:15 UTC (rev
14268)
@@ -166,7 +166,7 @@

    else
      {
        Process = Thread->ThreadsProcess;
-       ExAcquireFastMutex(&Process->TebLock);
+       PsLockProcess(Process, FALSE);
        if (NULL == Process->TebBlock ||
            Process->TebBlock == Process->TebLastAllocated)
          {
@@ -180,7 +180,7 @@
                                             PAGE_READWRITE);
            if (! NT_SUCCESS(Status))
              {
-               ExReleaseFastMutex(&Process->TebLock);
+               PsUnlockProcess(Process);
                DPRINT1("Failed to reserve virtual memory for TEB\n");
                return Status;
              }
@@ -199,7 +199,7 @@
            return Status;
          }
        Process->TebLastAllocated = TebBase;
-       ExReleaseFastMutex(&Process->TebLock);
+       PsUnlockProcess(Process);
      }
 
    DPRINT ("TebBase %p TebSize %lu\n", TebBase, TebSize);
  _____  

Modified: trunk/reactos/ntoskrnl/ps/kill.c
--- trunk/reactos/ntoskrnl/ps/kill.c	2005-03-22 17:17:02 UTC (rev
14267)
+++ trunk/reactos/ntoskrnl/ps/kill.c	2005-03-22 17:32:15 UTC (rev
14268)
@@ -101,9 +101,9 @@

         
             /* Make sure it didn't already terminate */
             if (!Thread->HasTerminated) {
-        
+
                 Thread->HasTerminated = TRUE;
-
+                
                 /* Terminate it by APC */
                 PspTerminateThreadByPointer(Thread, ExitStatus);
             }
@@ -143,7 +143,7 @@
     PETHREAD Thread = (PETHREAD)ObjectBody;
     PEPROCESS Process = Thread->ThreadsProcess;
 
-    DPRINT("PiDeleteThread(ObjectBody %x)\n",ObjectBody);
+    DPRINT("PiDeleteThread(ObjectBody 0x%x, process
0x%x)\n",ObjectBody, Thread->ThreadsProcess);
 
     /* Deassociate the Process */
     Thread->ThreadsProcess = NULL;
@@ -179,12 +179,15 @@
     PVOID TebBlock;
     PTERMINATION_PORT TerminationPort;
 
-    DPRINT("PsTerminateCurrentThread(ExitStatus %x), Current: 0x%x\n",
ExitStatus, PsGetCurrentThread());
+    DPRINT("PspExitThread(ExitStatus %x), Current: 0x%x\n", ExitStatus,
PsGetCurrentThread());
 
     /* Get the Current Thread and Process */
     CurrentThread = PsGetCurrentThread();
-    CurrentThread->HasTerminated = TRUE;
     CurrentProcess = CurrentThread->ThreadsProcess;
+    
+    /* Set the Exit Status and Exit Time */
+    CurrentThread->ExitStatus = ExitStatus;
+    KeQuerySystemTime(&CurrentThread->ExitTime);
 
     /* Can't terminate a thread if it attached another process */
     if (KeIsAttachedProcess()) {
@@ -198,16 +201,15 @@
     /* Lower to Passive Level */
     KeLowerIrql(PASSIVE_LEVEL);
 
+    /* Lock the Process before we modify its thread entries */
+    PsLockProcess(CurrentProcess, FALSE);
+    
+    /* wake up the thread so we don't deadlock on PsLockProcess */
+    KeForceResumeThread(&CurrentThread->Tcb);
+    
     /* Run Thread Notify Routines before we desintegrate the thread */
     PspRunCreateThreadNotifyRoutines(CurrentThread, FALSE);
-    
-    /* Set the Exit Status and Exit Time */
-    CurrentThread->ExitStatus = ExitStatus;
-    KeQuerySystemTime(&CurrentThread->ExitTime);
 
-    /* Lock the Process before we modify its thread entries */
-    PsLockProcess(CurrentProcess, FALSE);
-
     /* Remove the thread from the thread list of its process */
     RemoveEntryList(&CurrentThread->ThreadListEntry);
     Last = IsListEmpty(&CurrentProcess->ThreadListHead);
@@ -250,36 +252,31 @@
     PsTerminateWin32Thread(CurrentThread);
     if (Last) PsTerminateWin32Process(CurrentProcess);
    
-    /* Cancel I/O for the thread. */
-    IoCancelThreadIo(CurrentThread);
-   
     /* Rundown Registry Notifications. TODO (refers to NtChangeNotify,
not Cm callbacks) */
     //CmNotifyRunDown(CurrentThread);
-     
+    
     /* Free the TEB */
     if(CurrentThread->Tcb.Teb) {
-        
+
         DPRINT("Decommit teb at %p\n", CurrentThread->Tcb.Teb);
-        ExAcquireFastMutex(&CurrentProcess->TebLock);
         TebBlock = MM_ROUND_DOWN(CurrentThread->Tcb.Teb,
MM_VIRTMEM_GRANULARITY);
-     
+
         ZwFreeVirtualMemory(NtCurrentProcess(),
                            (PVOID *)&CurrentThread->Tcb.Teb,
                            &Length,
                            MEM_DECOMMIT);
-        
+
         DPRINT("teb %p, TebBlock %p\n", CurrentThread->Tcb.Teb,
TebBlock);
-     
+
         if (TebBlock != CurrentProcess->TebBlock ||
             CurrentProcess->TebBlock ==
CurrentProcess->TebLastAllocated) {
-            
+
             MmLockAddressSpace(&CurrentProcess->AddressSpace);
             MmReleaseMemoryAreaIfDecommitted(CurrentProcess,
&CurrentProcess->AddressSpace, TebBlock);
             MmUnlockAddressSpace(&CurrentProcess->AddressSpace);
         }
-    
+
         CurrentThread->Tcb.Teb = NULL;
-        ExReleaseFastMutex(&CurrentProcess->TebLock);
     }
    
     /* The last Thread shuts down the Process */
@@ -288,6 +285,9 @@
     /* Unlock the Process */
     PsUnlockProcess(CurrentProcess);
     
+    /* Cancel I/O for the thread. */
+    IoCancelThreadIo(CurrentThread);
+    
     /* Rundown Timers */
     ExTimerRundown();
     KeCancelTimer(&CurrentThread->Tcb.Timer);
@@ -318,7 +318,7 @@
 {
     NTSTATUS ExitStatus = (NTSTATUS)Apc->NormalContext;
     
-    DPRINT("PsExitSpecialApc called: 0x%x\n", PsGetCurrentThread());
+    DPRINT("PsExitSpecialApc called: 0x%x (proc: 0x%x)\n",
PsGetCurrentThread(), PsGetCurrentProcess());
     
     /* Free the APC */
     ExFreePool(Apc);
@@ -396,7 +396,7 @@
 STDCALL
 PspExitProcess(PEPROCESS Process)
 {
-    DPRINT("PspExitProcess\n");
+    DPRINT("PspExitProcess 0x%x\n", Process);
            
     PspRunCreateProcessNotifyRoutines(Process, FALSE);
            
@@ -421,25 +421,31 @@
 {
     NTSTATUS Status;
     PEPROCESS Process;
+    PETHREAD CurrentThread;
+    BOOLEAN KillByHandle;
    
     PAGED_CODE();
    
     DPRINT("NtTerminateProcess(ProcessHandle %x, ExitStatus %x)\n",
             ProcessHandle, ExitStatus);
     
+    KillByHandle = (ProcessHandle != NULL);
+
     /* Get the Process Object */
-    Status = ObReferenceObjectByHandle(ProcessHandle,
+    Status = ObReferenceObjectByHandle((KillByHandle ? ProcessHandle :
NtCurrentProcess()),
                                        PROCESS_TERMINATE,
                                        PsProcessType,
                                        KeGetPreviousMode(),
                                        (PVOID*)&Process,
                                        NULL);
     if (!NT_SUCCESS(Status)) {
-    
+
         DPRINT1("Invalid handle to Process\n");
         return(Status);
     }
     
+    CurrentThread = PsGetCurrentThread();
+    
     PsLockProcess(Process, FALSE);
     
     if(Process->ExitTime.QuadPart != 0)
@@ -450,36 +456,43 @@
     
     /* Terminate all the Process's Threads */
     PspTerminateProcessThreads(Process, ExitStatus);
-            
-    /* Only master thread remains... kill it off */
-    if (PsGetCurrentThread()->ThreadsProcess == Process) {
-        
+    
+    /* only kill the calling thread if it either passed a process
handle or
+       NtCurrentProcess() */
+    if (KillByHandle) {
+
         /* set the exit time as we're about to release the process lock
before
            we kill ourselves to prevent threads outside of our process
trying
            to kill us */
         KeQuerySystemTime(&Process->ExitTime);
-        
-        PsUnlockProcess(Process);
-        
-        /* we can safely dereference the process because the current
thread
-           holds a reference to it until it gets reaped */
-        ObDereferenceObject(Process);
-        
-        /* now the other threads get a chance to terminate, we don't
wait but
-           just kill ourselves right now. The process will be run down
when the
-           last thread terminates */
 
-        PspExitThread(ExitStatus);
-        
-        /* we should never reach this point! */
-        KEBUGCHECK(0);
+        /* Only master thread remains... kill it off */
+        if (CurrentThread->ThreadsProcess == Process) {
+
+            /* mark our thread as terminating so attempts to terminate
it, when
+               unlocking the process, fail */
+            CurrentThread->HasTerminated = TRUE;
+
+            PsUnlockProcess(Process);
+
+            /* we can safely dereference the process because the
current thread
+               holds a reference to it until it gets reaped */
+            ObDereferenceObject(Process);
+
+            /* now the other threads get a chance to terminate, we
don't wait but
+               just kill ourselves right now. The process will be run
down when the
+               last thread terminates */
+
+            PspExitThread(ExitStatus);
+
+            /* we should never reach this point! */
+            KEBUGCHECK(0);
+        }
     }
-    else
-    {
-        /* unlock and dereference the process so the threads can kill
themselves */
-        PsUnlockProcess(Process);
-        ObDereferenceObject(Process);
-    }
+
+    /* unlock and dereference the process so the threads can kill
themselves */
+    PsUnlockProcess(Process);
+    ObDereferenceObject(Process);
     
     return(STATUS_SUCCESS);
 }
@@ -501,7 +514,7 @@
                                        KeGetPreviousMode(),
                                        (PVOID*)&Thread,
                                        NULL);
-    if (Status != STATUS_SUCCESS) {
+    if (!NT_SUCCESS(Status)) {
         
         DPRINT1("Could not reference thread object\n");
         return(Status);
@@ -518,15 +531,27 @@
     /* Check to see if we're running in the same thread */
     if (Thread != PsGetCurrentThread())  {
                  
-         /* This isn't our thread, check if it's terminated already */
+        /* we need to lock the process to make sure it's not already
terminating */
+        PsLockProcess(Thread->ThreadsProcess, FALSE);
+        
+        /* This isn't our thread, terminate it if not already done */
         if (!Thread->HasTerminated) {
          
+             Thread->HasTerminated = TRUE;
+             
              /* Terminate it */
              PspTerminateThreadByPointer(Thread, ExitStatus);
-         }
+        }
         
+        PsUnlockProcess(Thread->ThreadsProcess);
+        
+        /* Dereference the Thread and return */
+        ObDereferenceObject(Thread);
+        
     } else {
 
+        Thread->HasTerminated = TRUE;
+        
         /* it's safe to dereference thread, there's at least the
keep-alive
            reference which will be removed by the thread reaper causing
the
            thread to be finally destroyed */
@@ -539,8 +564,6 @@
         KEBUGCHECK(0);
     }
     
-    /* Dereference the Thread and return */
-    ObDereferenceObject(Thread);
     return(STATUS_SUCCESS);
 }