1 ------------------------------------------------------------------------------
3 -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . I N T E R R U P T _ M A N A G E M E N T --
9 -- Copyright (C) 1991-1994, Florida State University --
10 -- Copyright (C) 1995-2003, Ada Core Technologies --
12 -- GNARL is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNARL; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
30 -- GNARL was developed by the GNARL team at Florida State University. --
31 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
33 ------------------------------------------------------------------------------
35 -- This is the GNU/Linux version of this package
37 -- This file performs the system-dependent translation between machine
38 -- exceptions and the Ada exceptions, if any, that should be raised when they
39 -- occur. This version works for the x86 running linux.
41 -- This is a Sun OS (FSU THREADS) version of this package
43 -- PLEASE DO NOT add any dependences on other packages. ??? why not ???
44 -- This package is designed to work with or without tasking support.
46 -- Make a careful study of all signals available under the OS, to see which
47 -- need to be reserved, kept always unmasked, or kept always unmasked. Be on
48 -- the lookout for special signals that may be used by the thread library.
50 -- The definitions of "reserved" differ slightly between the ARM and POSIX.
51 -- Here is the ARM definition of reserved interrupt:
53 -- The set of reserved interrupts is implementation defined. A reserved
54 -- interrupt is either an interrupt for which user-defined handlers are not
55 -- supported, or one which already has an attached handler by some other
56 -- implementation-defined means. Program units can be connected to
57 -- non-reserved interrupts.
59 -- POSIX.5b/.5c specifies further:
61 -- Signals which the application cannot accept, and for which the application
62 -- cannot modify the signal action or masking, because the signals are
63 -- reserved for use by the Ada language implementation. The reserved signals
64 -- defined by this standard are Signal_Abort, Signal_Alarm,
65 -- Signal_Floating_Point_Error, Signal_Illegal_Instruction,
66 -- Signal_Segmentation_Violation, Signal_Bus_Error. If the implementation
67 -- supports any signals besides those defined by this standard, the
68 -- implementation may also reserve some of those.
70 -- The signals defined by POSIX.5b/.5c that are not specified as being
71 -- reserved are SIGHUP, SIGINT, SIGPIPE, SIGQUIT, SIGTERM, SIGUSR1, SIGUSR2,
72 -- SIGCHLD, SIGCONT, SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGIO SIGURG, and all
73 -- the real-time signals.
75 -- Beware of reserving signals that POSIX.5b/.5c require to be available for
76 -- users. POSIX.5b/.5c say:
78 -- An implementation shall not impose restrictions on the ability of an
79 -- application to send, accept, block, or ignore the signals defined by this
80 -- standard, except as specified in this standard.
82 -- Here are some other relevant requirements from POSIX.5b/.5c:
84 -- For the environment task, the initial signal mask is that specified for
87 -- It is anticipated that the paragraph above may be modified by a future
88 -- revision of this standard, to require that the realtime signals always be
89 -- initially masked for a process that is an Ada active partition.
91 -- For all other tasks, the initial signal mask shall include all the signals
92 -- that are not reserved signals and are not bound to entries of the task.
95 -- used for int and other types
97 with System.Error_Reporting;
100 with System.OS_Interface;
101 -- used for various Constants, Signal and types
104 -- used for Exception_Id
105 -- Raise_From_Signal_Handler
107 with System.Soft_Links;
108 -- used for Get_Machine_State_Addr
110 with Unchecked_Conversion;
112 package body System.Interrupt_Management is
115 use System.Error_Reporting;
116 use System.OS_Interface;
118 package TSL renames System.Soft_Links;
120 type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID;
121 Exception_Interrupts : constant Interrupt_List :=
122 (SIGFPE, SIGILL, SIGSEGV);
124 Unreserve_All_Interrupts : Interfaces.C.int;
126 (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts");
128 subtype int is Interfaces.C.int;
129 subtype unsigned_short is Interfaces.C.unsigned_short;
130 subtype unsigned_long is Interfaces.C.unsigned_long;
132 ----------------------
133 -- Notify_Exception --
134 ----------------------
136 pragma Warnings (Off);
137 -- Because many unaccessed arguments
139 Signal_Mask : aliased sigset_t;
140 -- The set of signals handled by Notify_Exception
142 -- This function identifies the Ada exception to be raised using
143 -- the information when the system received a synchronous signal.
144 -- Since this function is machine and OS dependent, different code
145 -- has to be provided for different target.
147 procedure Notify_Exception
161 trapno : unsigned_long;
165 eflags : unsigned_long;
166 esp_at_signal : unsigned_long;
168 fpstate : System.Address;
169 oldmask : unsigned_long;
170 cr2 : unsigned_long);
172 procedure Notify_Exception
186 trapno : unsigned_long;
190 eflags : unsigned_long;
191 esp_at_signal : unsigned_long;
193 fpstate : System.Address;
194 oldmask : unsigned_long;
197 pragma Warnings (On);
199 function To_Machine_State_Ptr is new
200 Unchecked_Conversion (Address, Machine_State_Ptr);
202 -- These are not directly visible
204 procedure Raise_From_Signal_Handler
205 (E : Ada.Exceptions.Exception_Id;
208 (Ada, Raise_From_Signal_Handler,
209 "ada__exceptions__raise_from_signal_handler");
210 pragma No_Return (Raise_From_Signal_Handler);
212 mstate : Machine_State_Ptr;
213 message : aliased constant String := "" & ASCII.Nul;
214 -- A null terminated String.
220 -- Raise_From_Signal_Handler makes sure that the exception is raised
221 -- safely from this signal handler.
223 -- ??? The original signal mask (the one we had before coming into this
224 -- signal catching function) should be restored by
225 -- Raise_From_Signal_Handler. For now, restore it explicitely
227 Result := pthread_sigmask (SIG_UNBLOCK, Signal_Mask'Access, null);
228 pragma Assert (Result = 0);
230 -- Check that treatment of exception propagation here
231 -- is consistent with treatment of the abort signal in
232 -- System.Task_Primitives.Operations.
234 mstate := To_Machine_State_Ptr (TSL.Get_Machine_State_Addr.all);
237 mstate.esp := esp_at_signal;
244 Raise_From_Signal_Handler
245 (Constraint_Error'Identity, message'Address);
247 Raise_From_Signal_Handler
248 (Constraint_Error'Identity, message'Address);
250 Raise_From_Signal_Handler
251 (Storage_Error'Identity, message'Address);
253 if Shutdown ("Unexpected signal") then
257 end Notify_Exception;
259 ---------------------------
260 -- Initialize_Interrupts --
261 ---------------------------
263 -- Nothing needs to be done on this platform.
265 procedure Initialize_Interrupts is
268 end Initialize_Interrupts;
272 act : aliased struct_sigaction;
273 old_act : aliased struct_sigaction;
276 function State (Int : Interrupt_ID) return Character;
277 pragma Import (C, State, "__gnat_get_interrupt_state");
278 -- Get interrupt state. Defined in a-init.c
279 -- The input argument is the interrupt number,
280 -- and the result is one of the following:
282 User : constant Character := 'u';
283 Runtime : constant Character := 'r';
284 Default : constant Character := 's';
285 -- 'n' this interrupt not set by any Interrupt_State pragma
286 -- 'u' Interrupt_State pragma set state to User
287 -- 'r' Interrupt_State pragma set state to Runtime
288 -- 's' Interrupt_State pragma set state to System (use "default"
292 -- Need to call pthread_init very early because it is doing signal
297 Abort_Task_Interrupt := SIGADAABORT;
299 act.sa_handler := Notify_Exception'Address;
303 -- On some targets, we set sa_flags to SA_NODEFER so that during the
304 -- handler execution we do not change the Signal_Mask to be masked for
307 -- This is a temporary fix to the problem that the Signal_Mask is
308 -- not restored after the exception (longjmp) from the handler.
309 -- The right fix should be made in sigsetjmp so that we save
310 -- the Signal_Set and restore it after a longjmp.
312 -- Since SA_NODEFER is obsolete, instead we reset explicitely
313 -- the mask in the exception handler.
315 Result := sigemptyset (Signal_Mask'Access);
316 pragma Assert (Result = 0);
318 -- Add signals that map to Ada exceptions to the mask.
320 for J in Exception_Interrupts'Range loop
321 if State (Exception_Interrupts (J)) /= Default then
323 sigaddset (Signal_Mask'Access, Signal (Exception_Interrupts (J)));
324 pragma Assert (Result = 0);
328 act.sa_mask := Signal_Mask;
330 pragma Assert (Keep_Unmasked = (Interrupt_ID'Range => False));
331 pragma Assert (Reserve = (Interrupt_ID'Range => False));
333 -- Process state of exception signals
335 for J in Exception_Interrupts'Range loop
336 if State (Exception_Interrupts (J)) /= User then
337 Keep_Unmasked (Exception_Interrupts (J)) := True;
338 Reserve (Exception_Interrupts (J)) := True;
340 if State (Exception_Interrupts (J)) /= Default then
343 (Signal (Exception_Interrupts (J)), act'Unchecked_Access,
344 old_act'Unchecked_Access);
345 pragma Assert (Result = 0);
350 if State (Abort_Task_Interrupt) /= User then
351 Keep_Unmasked (Abort_Task_Interrupt) := True;
352 Reserve (Abort_Task_Interrupt) := True;
355 -- Set SIGINT to unmasked state as long as it's
356 -- not in "User" state. Check for Unreserve_All_Interrupts last
358 if State (SIGINT) /= User then
359 Keep_Unmasked (SIGINT) := True;
360 Reserve (SIGINT) := True;
363 -- Check all signals for state that requires keeping them
364 -- unmasked and reserved
366 for J in Interrupt_ID'Range loop
367 if State (J) = Default or else State (J) = Runtime then
368 Keep_Unmasked (J) := True;
373 -- Add the set of signals that must always be unmasked for this target
375 for J in Unmasked'Range loop
376 Keep_Unmasked (Interrupt_ID (Unmasked (J))) := True;
377 Reserve (Interrupt_ID (Unmasked (J))) := True;
380 -- Add target-specific reserved signals
382 for J in Reserved'Range loop
383 Reserve (Interrupt_ID (Reserved (J))) := True;
386 -- Process pragma Unreserve_All_Interrupts. This overrides any
387 -- settings due to pragma Interrupt_State:
389 if Unreserve_All_Interrupts /= 0 then
390 Keep_Unmasked (SIGINT) := False;
391 Reserve (SIGINT) := False;
394 -- We do not have Signal 0 in reality. We just use this value
395 -- to identify non-existent signals (see s-intnam.ads). Therefore,
396 -- Signal 0 should not be used in all signal related operations hence
397 -- mark it as reserved.
401 end System.Interrupt_Management;