Subversion Repositories planix.SVN

#include "lib.h"
#include "sys9.h"
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <setjmp.h>

extern sigset_t _psigblocked;

static struct {
        char    *msg;   /* just check prefix */
        int     num;
} sigtab[] = {
        {"hangup",                              SIGHUP},
        {"interrupt",                           SIGINT},
        {"quit",                                SIGQUIT},
        {"alarm",                               SIGALRM},
        {"sys: trap: illegal instruction",      SIGILL},
        {"sys: trap: reserved instruction",     SIGILL},
        {"sys: trap: reserved",                 SIGILL},
        {"sys: trap: arithmetic overflow",      SIGFPE},
        {"abort",                               SIGABRT},
        {"sys: fp:",                            SIGFPE},
        {"exit",                                SIGKILL},
        {"die",                                 SIGKILL},
        {"kill",                                SIGKILL},
        {"sys: trap: bus error",                SIGSEGV},
        {"sys: trap: address error",            SIGSEGV},
        {"sys: trap: TLB",                      SIGSEGV},
        {"sys: write on closed pipe",           SIGPIPE},
        {"alarm",                               SIGALRM},
        {"term",                                SIGTERM},
        {"usr1",                                SIGUSR1},
        {"usr2",                                SIGUSR2},
};
#define NSIGTAB ((sizeof sigtab)/(sizeof (sigtab[0])))

void    (*_sighdlr[MAXSIG+1])(int, char*, Ureg*); /* 0 initialized: SIG_DFL */

/* must match signal.h: extern void (*signal(int, void (*)()))(); */
//void (*signal(int sig, void (*func)(int, char*, Ureg*)))(int, char*, Ureg*)
void
(*signal(int sig, void (*func)()))()
{
        void(*oldf)(int, char*, Ureg*);

        if(sig <= 0 || sig > MAXSIG){
                errno = EINVAL;
                return SIG_ERR;
        }
        oldf = _sighdlr[sig];
        if(sig == SIGKILL)
                return oldf;    /* can't catch or ignore SIGKILL */
        _sighdlr[sig] = func;
        return oldf;
}

/* BAD CODE - see /sys/src/ape/lib/ap/$objtype/setjmp.s for real code
int
sigsetjmp(sigjmp_buf buf, int savemask)
{
        int r;

        buf[0] = savemask;
        buf[1] = _psigblocked;
        return setjmp(&buf[2]);
}
*/

/*
 * BUG: improper handling of process signal mask
 */
int
sigaction(int sig, struct sigaction *act, struct sigaction *oact)
{
        if(sig <= 0 || sig > MAXSIG || sig == SIGKILL){
                errno = EINVAL;
                return -1;
        }
        if(oact){
                oact->sa_handler = _sighdlr[sig];
                oact->sa_mask = _psigblocked;
                oact->sa_flags = 0;
        }
        if(act){
                _sighdlr[sig] = act->sa_handler;
        }
        return 0;
}

/* this is registered in _envsetup */
int
_notehandler(void *u, char *msg)
{
        int i;
        void(*f)(int, char*, Ureg*);
        extern void _doatexits(void);   /* in stdio/exit.c */

        if(_finishing)
                _finish(0, 0);
        for(i = 0; i<NSIGTAB; i++){
                if(strncmp(msg, sigtab[i].msg, strlen(sigtab[i].msg)) == 0){
                        f = _sighdlr[sigtab[i].num];
                        if(f == SIG_DFL || f == SIG_ERR)
                                break;
                        if(f != SIG_IGN) {
                                _notetramp(sigtab[i].num, f, u);
                                /* notetramp is machine-dependent; doesn't return to here */
                        }
                        _NOTED(0); /* NCONT */
                        return 0;
                }
        }
        _doatexits();
        _NOTED(1); /* NDFLT */
        return 0;
}

int
_stringsig(char *nam)
{
        int i;

        for(i = 0; i<NSIGTAB; i++)
                if(strncmp(nam, sigtab[i].msg, strlen(sigtab[i].msg)) == 0)
                        return sigtab[i].num;
        return 0;
}

char *
_sigstring(int sig)
{
        int i;

        for(i=0; i<NSIGTAB; i++)
                if(sigtab[i].num == sig)
                        return sigtab[i].msg;
        return "unknown signal";
}