Import sources from 2011-03-30 iso image

1 files changed, 272 insertions, 0 deletions

diff --git a/sys/src/libmach/access.c b/sys/src/libmach/access.c
new file mode 100755
index 000000000..784ee6158
--- /dev/null
+++ b/sys/src/libmach/access.c
@@ -0,0 +1,272 @@
+/*
+ * functions to read and write an executable or file image
+ */
+
+#include <u.h>
+#include <libc.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
+ */
+int
+geta(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;
+}
+
+int
+get8(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;
+}
+
+int
+get4(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;
+}
+
+int
+get2(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;
+}
+
+int
+get1(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;
+}
+
+int
+puta(Map *map, uvlong addr, uvlong v)
+{
+	if (mach->szaddr == 8)
+		return put8(map, addr, v);
+
+	return put4(map, addr, v);
+}
+
+int
+put8(Map *map, uvlong addr, uvlong v)
+{
+	if (!map) {
+		werrstr("put8: invalid map");
+		return -1;
+	}
+	v = machdata->swav(v);
+	return mput(map, addr, &v, 8);
+}
+
+int
+put4(Map *map, uvlong addr, ulong v)
+{
+	if (!map) {
+		werrstr("put4: invalid map");
+		return -1;
+	}
+	v = machdata->swal(v);
+	return mput(map, addr, &v, 4);
+}
+
+int
+put2(Map *map, uvlong addr, ushort v)
+{
+	if (!map) {
+		werrstr("put2: invalid map");
+		return -1;
+	}
+	v = machdata->swab(v);
+	return mput(map, addr, &v, 2);
+}
+
+int
+put1(Map *map, uvlong addr, uchar *v, int size)
+{
+	if (!map) {
+		werrstr("put1: invalid map");
+		return -1;
+	}
+	return mput(map, addr, v, size);
+}
+
+static int
+spread(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 int
+mget(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;
+	}
+	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 int
+mput(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;
+	}
+
+	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;
+}