PspLockProcessExclusive

VOID __stdcall PspLockProcessExclusive(_EPROCESS *Process, _ETHREAD *CurrentThread){
  --CurrentThread->Tcb.KernelApcDisable;
  ExAcquirePushLockExclusiveEx(&Process->ProcessLock, 0i64);
}

Referenced by:

NtSetInformationProcess
NtTerminateProcess
PspAllocateProcess
PspCreatePicoProcess