V5/usr/sys/ken/trap.c

#
/*
 *	Copyright 1973 Bell Telephone Laboratories Inc
 */

#include "../param.h"
#include "../systm.h"
#include "../user.h"
#include "../proc.h"
#include "../reg.h"
#include "../seg.h"

#define	EBIT	1
#define	UMODE	0170000
#define	SETD	0170011
struct sysent	{
	int	count;
	int	(*call)();
} sysent[64];
char	regloc[8]
{
	R0, R1, R2, R3, R4, R5, R6, R7
};

trap(dev, sp, r1, nps, r0, pc, ps)
char *sp;
{
	register i, a;
	register struct sysent *callp;

	savfp();
	u.u_ar0 = &r0;
	if(dev == 8) {
		psignal(u.u_procp, SIGFPT);
		if((ps&UMODE) == UMODE)
			goto err;
		return;
	}
	if(dev==1 && fuword(pc-2)==SETD && u.u_signal[SIGINS]==0)
		return;
	if((ps&UMODE) != UMODE)
		goto bad;
	u.u_error = 0;
	if(dev==9 && sp < -u.u_ssize*64) {
		if(backup(&r0) == 0)
		if(!estabur(u.u_tsize, u.u_dsize, u.u_ssize+SINCR)) {
			expand(u.u_procp->p_size+SINCR);
			a = u.u_procp->p_addr + u.u_procp->p_size;
			for(i=u.u_ssize; i; i--) {
				a--;
				copyseg(a-SINCR, a);
			}
			for(i=SINCR; i; i--)
				clearseg(--a);
			u.u_ssize =+ SINCR;
			goto err;
		}
	}
	switch(dev) {

	case 0:
		i = SIGBUS;
		goto def;

	case 1:
		i = SIGINS;
		goto def;

	case 2:
		i = SIGTRC;
		goto def;

	case 3:
		i = SIGIOT;
		goto def;

	case 5:
		i = SIGEMT;
		goto def;

	case 9:
		i = SIGSEG;
		goto def;

	def:
		psignal(u.u_procp, i);

	default:
		u.u_error = dev+100;

	case 6:;
	}
	if(u.u_error)
		goto err;
	ps =& ~EBIT;
	callp = &sysent[fuword(pc-2)&077];
	if (callp == sysent) { /* indirect */
		a = fuword(pc);
		pc =+ 2;
		callp = &sysent[fuword(a)&077];
		a =+ 2;
	} else {
		a = pc;
		pc =+ callp->count*2;
	}
	for(i=0; i < callp->count; i++) {
		u.u_arg[i] = fuword(a);
		a =+ 2;
	}
	u.u_dirp = u.u_arg[0];
	trap1(callp->call);
	if(u.u_error >= 100)
		psignal(u.u_procp, SIGSYS);
err:
	if(issig())
		psig();
	if(u.u_error != 0) {
		ps =| EBIT;
		r0 = u.u_error;
	}
	u.u_procp->p_pri = PUSER + u.u_nice;
	if(u.u_dsleep++ > 15) {
		u.u_dsleep = 0;
		u.u_procp->p_pri++;
		swtch();
	}
	return;

bad:
	printf("ka6 = %o\n", *ka6);
	printf("aps = %o\n", &ps);
	panic("trap");
}

trap1(f)
int (*f)();
{

	savu(u.u_qsav);
	(*f)();
}

nosys()
{

	u.u_error = 100;
}

nullsys()
{
}