File : s-stchop-vxworks.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- 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 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1999-2015, Free Software Foundation, Inc. --
10 -- --
11 -- GNARL is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 -- --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- This is the verson for VxWorks 5, VxWorks 6 Cert and VxWorks MILS
33
34 -- This file should be kept synchronized with the general implementation
35 -- provided by s-stchop.adb.
36
37 pragma Restrictions (No_Elaboration_Code);
38 -- We want to guarantee the absence of elaboration code because the
39 -- binder does not handle references to this package.
40
41 with System.Storage_Elements; use System.Storage_Elements;
42 with System.Parameters; use System.Parameters;
43 with Interfaces.C;
44
45 package body System.Stack_Checking.Operations is
46
47 -- In order to have stack checking working appropriately on VxWorks we need
48 -- to extract the stack size information from the VxWorks kernel itself.
49
50 -- For VxWorks 5 & 6 the library for showing task-related information
51 -- needs to be linked into the VxWorks system, when using stack checking.
52 -- The taskShow library can be linked into the VxWorks system by either:
53
54 -- * defining INCLUDE_SHOW_ROUTINES in config.h when using
55 -- configuration header files, or
56
57 -- * selecting INCLUDE_TASK_SHOW when using the Tornado project
58 -- facility.
59
60 -- VxWorks MILS includes the necessary routine in taskLib, so nothing
61 -- special needs to be done there.
62
63 Stack_Limit : Address;
64
65 pragma Import (C, Stack_Limit, "__gnat_stack_limit");
66
67 -- Stack_Limit contains the limit of the stack. This variable is later made
68 -- a task variable (by calling taskVarAdd) and then correctly set to the
69 -- stack limit of the task. Before being so initialized its value must be
70 -- valid so that any subprogram with stack checking enabled will run. We
71 -- use extreme values according to the direction of the stack.
72
73 type Set_Stack_Limit_Proc_Acc is access procedure;
74 pragma Convention (C, Set_Stack_Limit_Proc_Acc);
75
76 Set_Stack_Limit_Hook : Set_Stack_Limit_Proc_Acc;
77 pragma Import (C, Set_Stack_Limit_Hook, "__gnat_set_stack_limit_hook");
78 -- Procedure to be called when a task is created to set stack
79 -- limit.
80
81 procedure Set_Stack_Limit_For_Current_Task;
82 pragma Convention (C, Set_Stack_Limit_For_Current_Task);
83 -- Register Initial_SP as the initial stack pointer value for the current
84 -- task when it starts and Size as the associated stack area size. This
85 -- should be called once, after the soft-links have been initialized?
86
87 -----------------------------
88 -- Initialize_Stack_Limit --
89 -----------------------------
90
91 procedure Initialize_Stack_Limit is
92 begin
93
94 Set_Stack_Limit_For_Current_Task;
95
96 -- Will be called by every created task
97
98 Set_Stack_Limit_Hook := Set_Stack_Limit_For_Current_Task'Access;
99 end Initialize_Stack_Limit;
100
101 --------------------------------------
102 -- Set_Stack_Limit_For_Current_Task --
103 --------------------------------------
104
105 procedure Set_Stack_Limit_For_Current_Task is
106 use Interfaces.C;
107
108 type OS_Stack_Info is record
109 Size : Interfaces.C.int;
110 Base : System.Address;
111 Limit : System.Address;
112 end record;
113 pragma Convention (C, OS_Stack_Info);
114 -- Type representing the information that we want to extract from the
115 -- underlying kernel.
116
117 procedure Get_Stack_Info (Stack : not null access OS_Stack_Info);
118 pragma Import (C, Get_Stack_Info, "__gnat_get_stack_info");
119 -- Procedure that fills the stack information associated to the
120 -- currently executing task.
121
122 Stack_Info : aliased OS_Stack_Info;
123
124 Limit : System.Address;
125
126 begin
127
128 -- Get stack bounds from VxWorks
129
130 Get_Stack_Info (Stack_Info'Access);
131
132 if Stack_Grows_Down then
133 Limit :=
134 Stack_Info.Base - Storage_Offset (Stack_Info.Size) +
135 Storage_Offset'(12_000);
136 else
137 Limit :=
138 Stack_Info.Base + Storage_Offset (Stack_Info.Size) -
139 Storage_Offset'(12_000);
140 end if;
141
142 Stack_Limit := Limit;
143
144 end Set_Stack_Limit_For_Current_Task;
145 end System.Stack_Checking.Operations;