------------------------------------------------------------------------------ -- -- -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- S Y S T E M . S T A C K _ C H E C K I N G . O P E R A T I O N S -- -- -- -- B o d y -- -- -- -- Copyright (C) 1999-2009, Free Software Foundation, Inc. -- -- -- -- GNARL is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. -- -- -- -- As a special exception under Section 7 of GPL version 3, you are granted -- -- additional permissions described in the GCC Runtime Library Exception, -- -- version 3.1, as published by the Free Software Foundation. -- -- -- -- You should have received a copy of the GNU General Public License and -- -- a copy of the GCC Runtime Library Exception along with this program; -- -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- -- . -- -- -- -- GNARL was developed by the GNARL team at Florida State University. -- -- Extensive contributions were provided by Ada Core Technologies, Inc. -- -- -- ------------------------------------------------------------------------------ -- This is the verson for VxWorks 5 and VxWorks MILS -- This file should be kept synchronized with the general implementation -- provided by s-stchop.adb. pragma Restrictions (No_Elaboration_Code); -- We want to guarantee the absence of elaboration code because the -- binder does not handle references to this package. with System.Storage_Elements; use System.Storage_Elements; with System.Parameters; use System.Parameters; with Interfaces.C; package body System.Stack_Checking.Operations is -- In order to have stack checking working appropriately on VxWorks we need -- to extract the stack size information from the VxWorks kernel itself. -- For VxWorks 5 the library for showing task-related information needs to -- be linked into the VxWorks system, when using stack checking. The -- taskShow library can be linked into the VxWorks system by either: -- * defining INCLUDE_SHOW_ROUTINES in config.h when using -- configuration header files, or -- * selecting INCLUDE_TASK_SHOW when using the Tornado project -- facility. -- VxWorks MILS includes the necessary routine in taskLib, so nothing -- special needs to be done there. Stack_Limit : Address := Boolean'Pos (Stack_Grows_Down) * Address'First + Boolean'Pos (not Stack_Grows_Down) * Address'Last; pragma Export (C, Stack_Limit, "__gnat_stack_limit"); -- Stack_Limit contains the limit of the stack. This variable is later made -- a task variable (by calling taskVarAdd) and then correctly set to the -- stack limit of the task. Before being so initialized its value must be -- valid so that any subprogram with stack checking enabled will run. We -- use extreme values according to the direction of the stack. type Set_Stack_Limit_Proc_Acc is access procedure; pragma Convention (C, Set_Stack_Limit_Proc_Acc); Set_Stack_Limit_Hook : Set_Stack_Limit_Proc_Acc; pragma Import (C, Set_Stack_Limit_Hook, "__gnat_set_stack_limit_hook"); -- Procedure to be called when a task is created to set stack -- limit. procedure Set_Stack_Limit_For_Current_Task; pragma Convention (C, Set_Stack_Limit_For_Current_Task); -- Register Initial_SP as the initial stack pointer value for the current -- task when it starts and Size as the associated stack area size. This -- should be called once, after the soft-links have been initialized? ----------------------------- -- Initialize_Stack_Limit -- ----------------------------- procedure Initialize_Stack_Limit is begin -- For the environment task Set_Stack_Limit_For_Current_Task; -- Will be called by every created task Set_Stack_Limit_Hook := Set_Stack_Limit_For_Current_Task'Access; end Initialize_Stack_Limit; -------------------------------------- -- Set_Stack_Limit_For_Current_Task -- -------------------------------------- procedure Set_Stack_Limit_For_Current_Task is use Interfaces.C; function Task_Var_Add (Tid : Interfaces.C.int; Var : Address) return Interfaces.C.int; pragma Import (C, Task_Var_Add, "taskVarAdd"); -- Import from VxWorks type OS_Stack_Info is record Size : Interfaces.C.int; Base : System.Address; Limit : System.Address; end record; pragma Convention (C, OS_Stack_Info); -- Type representing the information that we want to extract from the -- underlying kernel. procedure Get_Stack_Info (Stack : not null access OS_Stack_Info); pragma Import (C, Get_Stack_Info, "__gnat_get_stack_info"); -- Procedure that fills the stack information associated to the -- currently executing task. Stack_Info : aliased OS_Stack_Info; Limit : System.Address; begin -- Get stack bounds from VxWorks Get_Stack_Info (Stack_Info'Access); -- In s-stchop.adb, we check for overflow in the following operations, -- but we have no such check in this vxworks version. Why not ??? if Stack_Grows_Down then Limit := Stack_Info.Base - Storage_Offset (Stack_Info.Size); else Limit := Stack_Info.Base + Storage_Offset (Stack_Info.Size); end if; -- Note: taskVarAdd implicitly calls taskVarInit if required if Task_Var_Add (0, Stack_Limit'Address) = 0 then Stack_Limit := Limit; end if; end Set_Stack_Limit_For_Current_Task; end System.Stack_Checking.Operations;