scripts/gdb: add helper and convenience function to look up tasks

                utils.container_of(t['thread_group']['next'],

                                   self.task_ptr_type, "thread_group")

        return t

def get_task_by_pid(pid):

    for task in TaskList():

        if int(task['pid']) == pid:

            return task

    return None

class LxTaskByPidFunc(gdb.Function):

    """Find Linux task by PID and return the task_struct variable.

$lx_task_by_pid(PID): Given PID, iterate over all tasks of the target and

return that task_struct variable which PID matches."""

    def __init__(self):

        super(LxTaskByPidFunc, self).__init__("lx_task_by_pid")

    def invoke(self, pid):

        task = get_task_by_pid(pid)

        if task:

            return task.dereference()

        else:

            raise gdb.GdbError("No task of PID " + str(pid))

LxTaskByPidFunc()

    import linux.symbols

    import linux.modules

    import linux.dmesg

    import linux.tasks