posix_signal.cpp

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/*
===========================================================================

Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company. 

This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).  

Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Doom 3 Source Code is distributed in the hope that it will be useful,
but WITHOUT 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
along with Doom 3 Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

===========================================================================
*/
#include "../../idlib/precompiled.h"
#include "posix_public.h"

#include <string.h>
#include <errno.h>

const int siglist[] = {
        SIGHUP,
        SIGQUIT,
        SIGILL,
        SIGTRAP,
        SIGIOT,
        SIGBUS,
        SIGFPE,
        SIGSEGV,
        SIGPIPE,
        SIGABRT,
        //      SIGTTIN,
        //      SIGTTOU,
        -1
        };

const char *signames[] = {
        "SIGHUP",
        "SIGQUIT",
        "SIGILL",
        "SIGTRAP",
        "SIGIOT",
        "SIGBUS",
        "SIGFPE",
        "SIGSEGV",
        "SIGPIPE",
        "SIGABRT",
        //      "SIGTTIN",
        //      "SIGTTOUT"
};

static char fatalError[ 1024 ];

/*
================
Posix_ClearSigs
================
*/
void Posix_ClearSigs( ) {
        struct sigaction action;
        int i;
        
        /* Set up the structure */
        action.sa_handler = SIG_DFL;
        sigemptyset( &action.sa_mask );
        action.sa_flags = 0;

        i = 0;
        while ( siglist[ i ] != -1 ) {
                if ( sigaction( siglist[ i ], &action, NULL ) != 0 ) {
                        Sys_Printf( "Failed to reset %s handler: %s\n", signames[ i ], strerror( errno ) );
                }
                i++;
        }
}

/*
================
sig_handler
================
*/
static void sig_handler( int signum, siginfo_t *info, void *context ) {
        static bool double_fault = false;
        
        if ( double_fault ) {
                Sys_Printf( "double fault %s, bailing out\n", strsignal( signum ) );
                Posix_Exit( signum );
        }
        
        double_fault = true;
        
        // NOTE: see sigaction man page, could verbose the whole siginfo_t and print human readable si_code
        Sys_Printf( "signal caught: %s\nsi_code %d\n", strsignal( signum ), info->si_code );    
        
#ifndef ID_BT_STUB
        Sys_Printf( "callstack:\n%s", Sys_GetCallStackCurStr( 30 ) );
#endif

        if ( fatalError[ 0 ] ) {
                Sys_Printf( "Was in fatal error shutdown: %s\n", fatalError );
        }
        
        Sys_Printf( "Trying to exit gracefully..\n" );
        
        Posix_SetExit( signum );
        
        common->Quit();
}

/*
================
Posix_InitSigs
================
*/
void Posix_InitSigs( ) {
        struct sigaction action;
        int i;

        fatalError[0] = '\0';
        
        /* Set up the structure */
        action.sa_sigaction = sig_handler;
        sigemptyset( &action.sa_mask );
        action.sa_flags = SA_SIGINFO | SA_NODEFER;

        i = 0;
        while ( siglist[ i ] != -1 ) {
                if ( siglist[ i ] == SIGFPE ) {
                        action.sa_sigaction = Sys_FPE_handler;
                        if ( sigaction( siglist[ i ], &action, NULL ) != 0 ) {
                                Sys_Printf( "Failed to set SIGFPE handler: %s\n", strerror( errno ) );
                        }
                        action.sa_sigaction = sig_handler;
                } else if ( sigaction( siglist[ i ], &action, NULL ) != 0 ) {
                        Sys_Printf( "Failed to set %s handler: %s\n", signames[ i ], strerror( errno ) );
                }
                i++;
        }

        // if the process is backgrounded (running non interactively)
        // then SIGTTIN or SIGTOU could be emitted, if not caught, turns into a SIGSTP
        signal( SIGTTIN, SIG_IGN );
        signal( SIGTTOU, SIG_IGN );     
}

/*
==================
Sys_SetFatalError
==================
*/
void Sys_SetFatalError( const char *error ) {
        strncpy( fatalError, error, sizeof( fatalError ) );
}