/* * functions to read and write an executable or file image */ #include <lib9.h>#include <bio.h>#include "mach.h" static	int	mget(Map*, uvlong, void*, int);static	int	mput(Map*, uvlong, void*, int);static	struct	segment*	reloc(Map*, uvlong, vlong*); /* * routines to get/put various types */intgeta(Map *map, uvlong addr, uvlong *x){	ulong l;	uvlong vl; 	if (mach->szaddr == 8){		if (get8(map, addr, &vl) < 0)			return -1;		*x = vl;		return 1;	} 	if (get4(map, addr, &l) < 0)		return -1;	*x = l; 	return 1;} intget8(Map *map, uvlong addr, uvlong *x){	if (!map) {		werrstr("get8: invalid map");		return -1;	} 	if (map->nsegs == 1 && map->seg[0].fd < 0) {		*x = addr;		return 1;	}	if (mget(map, addr, x, 8) < 0)		return -1;	*x = machdata->swav(*x);	return 1;} intget4(Map *map, uvlong addr, ulong *x){	if (!map) {		werrstr("get4: invalid map");		return -1;	} 	if (map->nsegs == 1 && map->seg[0].fd < 0) {		*x = addr;		return 1;	}	if (mget(map, addr, x, 4) < 0)		return -1;	*x = machdata->swal(*x);	return 1;} intget2(Map *map, uvlong addr, ushort *x){	if (!map) {		werrstr("get2: invalid map");		return -1;	} 	if (map->nsegs == 1 && map->seg[0].fd < 0) {		*x = addr;		return 1;	}	if (mget(map, addr, x, 2) < 0)		return -1;	*x = machdata->swab(*x);	return 1;} intget1(Map *map, uvlong addr, uchar *x, int size){	uchar *cp; 	if (!map) {		werrstr("get1: invalid map");		return -1;	} 	if (map->nsegs == 1 && map->seg[0].fd < 0) {		cp = (uchar*)&addr;		while (cp < (uchar*)(&addr+1) && size-- > 0)			*x++ = *cp++;		while (size-- > 0)			*x++ = 0;	} else		return mget(map, addr, x, size);	return 1;} intputa(Map *map, uvlong addr, uvlong v){	if (mach->szaddr == 8)		return put8(map, addr, v); 	return put4(map, addr, v);} intput8(Map *map, uvlong addr, uvlong v){	if (!map) {		werrstr("put8: invalid map");		return -1;	}	v = machdata->swav(v);	return mput(map, addr, &v, 8);} intput4(Map *map, uvlong addr, ulong v){	if (!map) {		werrstr("put4: invalid map");		return -1;	}	v = machdata->swal(v);	return mput(map, addr, &v, 4);} intput2(Map *map, uvlong addr, ushort v){	if (!map) {		werrstr("put2: invalid map");		return -1;	}	v = machdata->swab(v);	return mput(map, addr, &v, 2);} intput1(Map *map, uvlong addr, uchar *v, int size){	if (!map) {		werrstr("put1: invalid map");		return -1;	}	return mput(map, addr, v, size);} static intspread(struct segment *s, void *buf, int n, uvlong off){	uvlong base; 	static struct {		struct segment *s;		char a[8192];		uvlong off;	} cache; 	if(s->cache){		base = off&~(sizeof cache.a-1);		if(cache.s != s || cache.off != base){			cache.off = ~0;			if(seek(s->fd, base, 0) >= 0			&& readn(s->fd, cache.a, sizeof cache.a) == sizeof cache.a){				cache.s = s;				cache.off = base;			}		}		if(cache.s == s && cache.off == base){			off &= sizeof cache.a-1;			if(off+n > sizeof cache.a)				n = sizeof cache.a - off;			memmove(buf, cache.a+off, n);			return n;		}	} 	return pread(s->fd, buf, n, off);} static intmget(Map *map, uvlong addr, void *buf, int size){	uvlong off;	int i, j, k;	struct segment *s; 	s = reloc(map, addr, (vlong*)&off);	if (!s)		return -1;	if (s->fd < 0) {		werrstr("unreadable map");		return -1;	}	if (s->mget)		return s->mget(s, addr, off, buf, size);	for (i = j = 0; i < 2; i++) {	/* in case read crosses page */		k = spread(s, (void*)((uchar *)buf+j), size-j, off+j);		if (k < 0) {			werrstr("can't read address %llux: %r", addr);			return -1;		}		j += k;		if (j == size)			return j;	}	werrstr("partial read at address %llux (size %d j %d)", addr, size, j);	return -1;} static intmput(Map *map, uvlong addr, void *buf, int size){	vlong off;	int i, j, k;	struct segment *s; 	s = reloc(map, addr, &off);	if (!s)		return -1;	if (s->fd < 0) {		werrstr("unwritable map");		return -1;	}	if (s->mput)		return s->mput(s, addr, off, buf, size); 	seek(s->fd, off, 0);	for (i = j = 0; i < 2; i++) {	/* in case read crosses page */		k = write(s->fd, buf, size-j);		if (k < 0) {			werrstr("can't write address %llux: %r", addr);			return -1;		}		j += k;		if (j == size)			return j;	}	werrstr("partial write at address %llux", addr);	return -1;} /* *	convert address to file offset; returns nonzero if ok */static struct segment*reloc(Map *map, uvlong addr, vlong *offp){	int i; 	for (i = 0; i < map->nsegs; i++) {		if (map->seg[i].inuse)		if (map->seg[i].b <= addr && addr < map->seg[i].e) {			*offp = addr + map->seg[i].f - map->seg[i].b;			return &map->seg[i];		}	}	werrstr("can't translate address %llux", addr);	return 0;}