------------------------------------------------------------------------------ -- -- -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- -- -- -- 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 -- -- -- -- B o d y -- -- -- -- -- -- Copyright (C) 1991-2002 Florida State University -- -- -- -- 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 2, or (at your option) any later ver- -- -- sion. GNARL 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. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNARL; see file COPYING. If not, write -- -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, USA. -- -- -- -- As a special exception, if other files instantiate generics from this -- -- unit, or you link this unit with other files to produce an executable, -- -- this unit does not by itself cause the resulting executable to be -- -- covered by the GNU General Public License. This exception does not -- -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- -- GNARL was developed by the GNARL team at Florida State University. It is -- -- now maintained by Ada Core Technologies Inc. in cooperation with Florida -- -- State University (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ -- This is the GNU/Linux version of this package -- This file performs the system-dependent translation between machine -- exceptions and the Ada exceptions, if any, that should be raised when they -- occur. This version works for the x86 running linux. -- This is a Sun OS (FSU THREADS) version of this package -- PLEASE DO NOT add any dependences on other packages. ??? why not ??? -- This package is designed to work with or without tasking support. -- Make a careful study of all signals available under the OS, to see which -- need to be reserved, kept always unmasked, or kept always unmasked. Be on -- the lookout for special signals that may be used by the thread library. -- The definitions of "reserved" differ slightly between the ARM and POSIX. -- Here is the ARM definition of reserved interrupt: -- The set of reserved interrupts is implementation defined. A reserved -- interrupt is either an interrupt for which user-defined handlers are not -- supported, or one which already has an attached handler by some other -- implementation-defined means. Program units can be connected to -- non-reserved interrupts. -- POSIX.5b/.5c specifies further: -- Signals which the application cannot accept, and for which the application -- cannot modify the signal action or masking, because the signals are -- reserved for use by the Ada language implementation. The reserved signals -- defined by this standard are Signal_Abort, Signal_Alarm, -- Signal_Floating_Point_Error, Signal_Illegal_Instruction, -- Signal_Segmentation_Violation, Signal_Bus_Error. If the implementation -- supports any signals besides those defined by this standard, the -- implementation may also reserve some of those. -- The signals defined by POSIX.5b/.5c that are not specified as being -- reserved are SIGHUP, SIGINT, SIGPIPE, SIGQUIT, SIGTERM, SIGUSR1, SIGUSR2, -- SIGCHLD, SIGCONT, SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGIO SIGURG, and all -- the real-time signals. -- Beware of reserving signals that POSIX.5b/.5c require to be available for -- users. POSIX.5b/.5c say: -- An implementation shall not impose restrictions on the ability of an -- application to send, accept, block, or ignore the signals defined by this -- standard, except as specified in this standard. -- Here are some other relevant requirements from POSIX.5b/.5c: -- For the environment task, the initial signal mask is that specified for -- the process... -- It is anticipated that the paragraph above may be modified by a future -- revision of this standard, to require that the realtime signals always be -- initially masked for a process that is an Ada active partition. -- For all other tasks, the initial signal mask shall include all the signals -- that are not reserved signals and are not bound to entries of the task. with Interfaces.C; -- used for int and other types with System.Error_Reporting; -- used for Shutdown with System.OS_Interface; -- used for various Constants, Signal and types with Ada.Exceptions; -- used for Exception_Id -- Raise_From_Signal_Handler with System.Soft_Links; -- used for Get_Machine_State_Addr with Unchecked_Conversion; package body System.Interrupt_Management is use Interfaces.C; use System.Error_Reporting; use System.OS_Interface; package TSL renames System.Soft_Links; type Interrupt_List is array (Interrupt_ID range <>) of Interrupt_ID; Exception_Interrupts : constant Interrupt_List := (SIGFPE, SIGILL, SIGSEGV); Unreserve_All_Interrupts : Interfaces.C.int; pragma Import (C, Unreserve_All_Interrupts, "__gl_unreserve_all_interrupts"); subtype int is Interfaces.C.int; subtype unsigned_short is Interfaces.C.unsigned_short; subtype unsigned_long is Interfaces.C.unsigned_long; ---------------------- -- Notify_Exception -- ---------------------- Signal_Mask : aliased sigset_t; -- The set of signals handled by Notify_Exception -- This function identifies the Ada exception to be raised using -- the information when the system received a synchronous signal. -- Since this function is machine and OS dependent, different code -- has to be provided for different target. procedure Notify_Exception (signo : Signal; gs : unsigned_short; fs : unsigned_short; es : unsigned_short; ds : unsigned_short; edi : unsigned_long; esi : unsigned_long; ebp : unsigned_long; esp : unsigned_long; ebx : unsigned_long; edx : unsigned_long; ecx : unsigned_long; eax : unsigned_long; trapno : unsigned_long; err : unsigned_long; eip : unsigned_long; cs : unsigned_short; eflags : unsigned_long; esp_at_signal : unsigned_long; ss : unsigned_short; fpstate : System.Address; oldmask : unsigned_long; cr2 : unsigned_long); procedure Notify_Exception (signo : Signal; gs : unsigned_short; fs : unsigned_short; es : unsigned_short; ds : unsigned_short; edi : unsigned_long; esi : unsigned_long; ebp : unsigned_long; esp : unsigned_long; ebx : unsigned_long; edx : unsigned_long; ecx : unsigned_long; eax : unsigned_long; trapno : unsigned_long; err : unsigned_long; eip : unsigned_long; cs : unsigned_short; eflags : unsigned_long; esp_at_signal : unsigned_long; ss : unsigned_short; fpstate : System.Address; oldmask : unsigned_long; cr2 : unsigned_long) is function To_Machine_State_Ptr is new Unchecked_Conversion (Address, Machine_State_Ptr); -- These are not directly visible procedure Raise_From_Signal_Handler (E : Ada.Exceptions.Exception_Id; M : System.Address); pragma Import (Ada, Raise_From_Signal_Handler, "ada__exceptions__raise_from_signal_handler"); pragma No_Return (Raise_From_Signal_Handler); mstate : Machine_State_Ptr; message : aliased constant String := "" & ASCII.Nul; -- a null terminated String. Result : int; begin -- Raise_From_Signal_Handler makes sure that the exception is raised -- safely from this signal handler. -- ??? The original signal mask (the one we had before coming into this -- signal catching function) should be restored by -- Raise_From_Signal_Handler. For now, restore it explicitly Result := pthread_sigmask (SIG_UNBLOCK, Signal_Mask'Access, null); pragma Assert (Result = 0); -- Check that treatment of exception propagation here -- is consistent with treatment of the abort signal in -- System.Task_Primitives.Operations. mstate := To_Machine_State_Ptr (TSL.Get_Machine_State_Addr.all); mstate.eip := eip; mstate.ebx := ebx; mstate.esp := esp_at_signal; mstate.ebp := ebp; mstate.esi := esi; mstate.edi := edi; case signo is when SIGFPE => Raise_From_Signal_Handler (Constraint_Error'Identity, message'Address); when SIGILL => Raise_From_Signal_Handler (Constraint_Error'Identity, message'Address); when SIGSEGV => Raise_From_Signal_Handler (Storage_Error'Identity, message'Address); when others => if Shutdown ("Unexpected signal") then null; end if; end case; end Notify_Exception; --------------------------- -- Initialize_Interrupts -- --------------------------- -- Nothing needs to be done on this platform. procedure Initialize_Interrupts is begin null; end Initialize_Interrupts; begin declare act : aliased struct_sigaction; old_act : aliased struct_sigaction; Result : int; begin -- Need to call pthread_init very early because it is doing signal -- initializations. pthread_init; Abort_Task_Interrupt := SIGADAABORT; act.sa_handler := Notify_Exception'Address; act.sa_flags := 0; -- On some targets, we set sa_flags to SA_NODEFER so that during the -- handler execution we do not change the Signal_Mask to be masked for -- the Signal. -- This is a temporary fix to the problem that the Signal_Mask is -- not restored after the exception (longjmp) from the handler. -- The right fix should be made in sigsetjmp so that we save -- the Signal_Set and restore it after a longjmp. -- Since SA_NODEFER is obsolete, instead we reset explicitly -- the mask in the exception handler. Result := sigemptyset (Signal_Mask'Access); pragma Assert (Result = 0); for J in Exception_Interrupts'Range loop Result := sigaddset (Signal_Mask'Access, Signal (Exception_Interrupts (J))); pragma Assert (Result = 0); end loop; act.sa_mask := Signal_Mask; for J in Exception_Interrupts'Range loop Keep_Unmasked (Exception_Interrupts (J)) := True; Result := sigaction (Signal (Exception_Interrupts (J)), act'Unchecked_Access, old_act'Unchecked_Access); pragma Assert (Result = 0); end loop; Keep_Unmasked (Abort_Task_Interrupt) := True; -- By keeping SIGINT unmasked, allow the user to do a Ctrl-C, but in the -- same time, disable the ability of handling this signal -- via Ada.Interrupts. -- The pragma Unreserve_All_Interrupts allows the user to -- change this behavior. if Unreserve_All_Interrupts = 0 then Keep_Unmasked (SIGINT) := True; end if; for J in Unmasked'Range loop Keep_Unmasked (Interrupt_ID (Unmasked (J))) := True; end loop; Reserve := Keep_Unmasked or Keep_Masked; for J in Reserved'Range loop Reserve (Interrupt_ID (Reserved (J))) := True; end loop; Reserve (0) := True; -- We do not have Signal 0 in reality. We just use this value -- to identify non-existent signals (see s-intnam.ads). Therefore, -- Signal 0 should not be used in all signal related operations hence -- mark it as reserved. end; end System.Interrupt_Management;