2.9BSD/usr/src/cmd/adb/access.c

#
/*
 *
 *	UNIX debugger
 *
 */

#include "defs.h"


MSG		ODDADR;
MSG		BADDAT;
MSG		BADTXT;
MAP		txtmap;
MAP		datmap;
INT		wtflag;
STRING		errflg;
INT		errno;

INT		pid;

struct ovhead		ovlseg;
L_INT		ovloff[];
OVTAG		curov;
int		overlay;

L_INT		var[];



/* file handling and access routines */

put(adr,space,value)
L_INT	adr;
{
	access(WT,adr,space,value);
}

POS	get(adr, space)
L_INT		adr;
{
	return(access(RD,adr,space,0));
}

POS	chkget(n, space)
L_INT		n;
{
	REG INT		w;

	w = get(n, space);
	chkerr();
	return(w);
}

access(mode,adr,space,value)
L_INT	adr;
{
	INT		w, w1, pmode, rd, file;
	BKPTR	bkptr, scanbkpt();
	rd = mode==RD;

	IF space == NSP THEN return(0); FI

	IF pid		/* tracing on? */
	THEN IF (adr&01) ANDF !rd THEN error(ODDADR); FI
	     pmode = (space&DSP?(rd?RDUSER:WDUSER):(rd?RIUSER:WIUSER));
	     if (bkptr=scanbkpt((POS)adr)) {
		if (rd) {
		    return(bkptr->ins);
		} else {
		    bkptr->ins = value;
		    return(0);
		}
	     }
	     w = ptrace(pmode, pid, shorten(adr&~01), value);
	     IF adr&01
	     THEN w1 = ptrace(pmode, pid, shorten(adr+1), value);
		  w = (w>>8)&LOBYTE | (w1<<8);
	     FI
	     IF errno
	     THEN errflg = (space&DSP ? BADDAT : BADTXT);
	     FI
	     return(w);
	FI
	w = 0;
	IF mode==WT ANDF wtflag==0
	THEN	error("not in write mode");
	FI
	IF !chkmap(&adr,space)
	THEN return(0);
	FI
	file=(space&DSP?datmap.ufd:txtmap.ufd);
	IF longseek(file,adr)==0 ORF
	   (rd ? read(file,&w,2) : write(file,&value,2)) < 1
	THEN	errflg=(space&DSP?BADDAT:BADTXT);
	FI
	return(w);

}

chkmap(adr,space)
	REG L_INT	*adr;
	REG INT		space;
{
	REG MAPPTR amap;
	amap=((space&DSP?&datmap:&txtmap));
	switch(space&(ISP|DSP|STAR)) {

		case ISP:
			IF within(*adr, amap->b1, amap->e1)
			THEN *adr += (amap->f1) - (amap->b1);
				break;
			ELIF within(*adr, amap->bo, amap->eo)
			THEN *adr += (amap->fo) - (amap->bo);
				break;
			FI
			/* falls through */

		case ISP+STAR:
			IF within(*adr, amap->b2, amap->e2)
			THEN *adr += (amap->f2) - (amap->b2);
				break;
			ELSE goto error;
			FI

		case DSP:
			IF within(*adr, amap->b1, amap->e1)
			THEN *adr += (amap->f1) - (amap->b1);
				break;
			FI
			/* falls through */

		case DSP+STAR:
			IF within(*adr, amap->b2, amap->e2)
			THEN *adr += (amap->f2) - (amap->b2);
				break;
			FI
			/* falls through */

		default:
		error:
			errflg = (space&DSP ? BADDAT: BADTXT);
			return(0);
	}
	return(1);
}

setovmap(ovno)
OVTAG ovno;
{
	REG MAPPTR amap;

	if ((!overlay) || (ovno < 0) || (ovno > 7))
		return;
	amap = &txtmap;
	IF ovno == 0
	THEN	amap->eo = amap->bo;
		amap->fo = 0;
	ELSE 	amap->eo = amap->bo + ovlseg.ov[ovno-1];
		amap->fo = ovloff[ovno-1];
	FI
	var[VARC] = curov = ovno;
	if (pid)
		choverlay(ovno);
}

within(adr,lbd,ubd)
L_INT	adr, lbd, ubd;
{
	return(adr>=lbd && adr<ubd);
}