libfdt: More consistent handling of returned error codes.

At present, libfdt functions returning a structure offset return a
zero-or-positive offset on success, and return a negative error code
on failure.  Functions which only return an error code return a
positive version of the error code, or 0 on success.

This patch improves consistency by always returning negative error
codes on failure, for both types of function.  With this change, we do
away with the special fdt_offset_error() macro for checking whether a
returned offset value is an error and extracting the encoded error
value within.  Instead an explicit (ret_value < 0) is now the
preferred way of checking return values for both offset-returning and
error-code-returning functions.

The fdt_strerror() function in the test code is updated
correspondingly to make more sense with the new conventions.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

fdt.c

@@ -28,15 +28,15 @@ int _fdt_check_header(const void *fdt)
 	if (fdt_magic(fdt) == FDT_MAGIC) {
 		/* Complete tree */
 		if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
-			return FDT_ERR_BADVERSION;
+			return -FDT_ERR_BADVERSION;
 		if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
-			return FDT_ERR_BADVERSION;
+			return -FDT_ERR_BADVERSION;
 	} else if (fdt_magic(fdt) == SW_MAGIC) {
 		/* Unfinished sequential-write blob */
 		if (fdt_size_dt_struct(fdt) == 0)
-			return FDT_ERR_BADSTATE;
+			return -FDT_ERR_BADSTATE;
 	} else {
-		return FDT_ERR_BADMAGIC;
+		return -FDT_ERR_BADMAGIC;
 	}
 
 	return 0;
@@ -117,8 +117,8 @@ int fdt_move(const void *fdt, void *buf, int bufsize)
 		return err;
 
 	if (fdt_totalsize(fdt) > bufsize)
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 
 	memmove(buf, fdt, fdt_totalsize(fdt));
-	return FDT_ERR_OK;
+	return 0;
 }

fdt_ro.c

@@ -23,11 +23,11 @@
 
 #include "libfdt_internal.h"
 
-#define OFFSET_CHECK_HEADER(fdt) \
+#define CHECK_HEADER(fdt) \
 	{ \
 		int err; \
 		if ((err = _fdt_check_header(fdt)) != 0) \
-			return OFFSET_ERROR(err); \
+			return err; \
 	}
 
 static int offset_streq(const void *fdt, int offset,
@@ -60,11 +60,11 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
 	uint32_t tag;
 	int offset, nextoffset;
 
-	OFFSET_CHECK_HEADER(fdt);
+	CHECK_HEADER(fdt);
 
 	tag = _fdt_next_tag(fdt, parentoffset, &nextoffset);
 	if (tag != FDT_BEGIN_NODE)
-		return OFFSET_ERROR(FDT_ERR_BADOFFSET);
+		return -FDT_ERR_BADOFFSET;
 
 	do {
 		offset = nextoffset;
@@ -72,7 +72,7 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
 
 		switch (tag) {
 		case FDT_END:
-			return OFFSET_ERROR(FDT_ERR_TRUNCATED);
+			return -FDT_ERR_TRUNCATED;
 
 		case FDT_BEGIN_NODE:
 			level++;
@@ -92,11 +92,11 @@ int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
 			break;
 
 		default:
-			return OFFSET_ERROR(FDT_ERR_BADSTRUCTURE);
+			return -FDT_ERR_BADSTRUCTURE;
 		}
 	} while (level >= 0);
 
-	return OFFSET_ERROR(FDT_ERR_NOTFOUND);
+	return -FDT_ERR_NOTFOUND;
 }
 
 int fdt_subnode_offset(const void *fdt, int parentoffset,
@@ -111,10 +111,10 @@ int fdt_path_offset(const void *fdt, const char *path)
 	const char *p = path;
 	int offset = 0;
 
-	OFFSET_CHECK_HEADER(fdt);
+	CHECK_HEADER(fdt);
 
 	if (*path != '/')
-		return OFFSET_ERROR(FDT_ERR_BADPATH);
+		return -FDT_ERR_BADPATH;
 
 	while (*p) {
 		const char *q;
@@ -122,13 +122,13 @@ int fdt_path_offset(const void *fdt, const char *path)
 		while (*p == '/')
 			p++;
 		if (! *p)
-			return OFFSET_ERROR(FDT_ERR_BADPATH);
+			return -FDT_ERR_BADPATH;
 		q = strchr(p, '/');
 		if (! q)
 			q = end;
 
 		offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p);
-		if (fdt_offset_error(offset))
+		if (offset < 0)
 			return offset;
 
 		p = q;
@@ -151,7 +151,7 @@ struct fdt_property *fdt_get_property(const void *fdt,
 	if ((err = _fdt_check_header(fdt)) != 0)
 		goto fail;
 
-	err = FDT_ERR_BADOFFSET;
+	err = -FDT_ERR_BADOFFSET;
 	if (nodeoffset % FDT_TAGSIZE)
 		goto fail;
 
@@ -161,14 +161,14 @@ struct fdt_property *fdt_get_property(const void *fdt,
 
 	do {
 		offset = nextoffset;
-		err = FDT_ERR_INTERNAL;
+		err = -FDT_ERR_INTERNAL;
 		if (offset % FDT_TAGSIZE)
 			goto fail;
 
 		tag = _fdt_next_tag(fdt, offset, &nextoffset);
 		switch (tag) {
 		case FDT_END:
-			err = FDT_ERR_TRUNCATED;
+			err = -FDT_ERR_TRUNCATED;
 			goto fail;
 
 		case FDT_BEGIN_NODE:
@@ -183,7 +183,7 @@ struct fdt_property *fdt_get_property(const void *fdt,
 			if (level != 0)
 				continue;
 
-			err = FDT_ERR_BADSTRUCTURE;
+			err = -FDT_ERR_BADSTRUCTURE;
 			prop = fdt_offset_ptr_typed(fdt, offset, prop);
 			if (! prop)
 				goto fail;
@@ -207,15 +207,15 @@ struct fdt_property *fdt_get_property(const void *fdt,
 			break;
 
 		default:
-			err = FDT_ERR_BADSTRUCTURE;
+			err = -FDT_ERR_BADSTRUCTURE;
 			goto fail;
 		}
 	} while (level >= 0);
 
-	err = FDT_ERR_NOTFOUND;
+	err = -FDT_ERR_NOTFOUND;
  fail:
 	if (lenp)
-		*lenp = -err;
+		*lenp = err;
 	return NULL;
 }
 

fdt_rw.c

@@ -30,26 +30,26 @@ static int rw_check_header(void *fdt)
 	if ((err = _fdt_check_header(fdt)))
 		return err;
 	if (fdt_version(fdt) < 0x11)
-		return FDT_ERR_BADVERSION;
+		return -FDT_ERR_BADVERSION;
 	if (fdt_off_mem_rsvmap(fdt) < ALIGN(sizeof(struct fdt_header), 8))
-		return FDT_ERR_BADLAYOUT;
+		return -FDT_ERR_BADLAYOUT;
 	if (fdt_off_dt_struct(fdt) <
 	    (fdt_off_mem_rsvmap(fdt) + sizeof(struct fdt_reserve_entry)))
-		return FDT_ERR_BADLAYOUT;
+		return -FDT_ERR_BADLAYOUT;
 	if (fdt_off_dt_strings(fdt) <
 	    (fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt)))
-		return FDT_ERR_BADLAYOUT;
+		return -FDT_ERR_BADLAYOUT;
 	if (fdt_totalsize(fdt) <
 	    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)))
-		return FDT_ERR_BADLAYOUT;
+		return -FDT_ERR_BADLAYOUT;
 	return 0;
 }
 
-#define RW_OFFSET_CHECK_HEADER(fdt) \
+#define RW_CHECK_HEADER(fdt) \
 	{ \
 		int err; \
 		if ((err = rw_check_header(fdt)) != 0) \
-			return OFFSET_ERROR(err); \
+			return err; \
 	}
 
 static inline int _blob_data_size(void *fdt)
@@ -62,9 +62,9 @@ static int _blob_splice(void *fdt, void *p, int oldlen, int newlen)
 	void *end = fdt + _blob_data_size(fdt);
 
 	if (((p + oldlen) < p) || ((p + oldlen) > end))
-		return FDT_ERR_BADOFFSET;
+		return -FDT_ERR_BADOFFSET;
 	if ((end - oldlen + newlen) > (fdt + fdt_totalsize(fdt)))
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 	memmove(p + newlen, p + oldlen, end - p - oldlen);
 	return 0;
 }
@@ -111,7 +111,7 @@ static int _find_add_string(void *fdt, const char *s)
 	new = strtab + fdt_size_dt_strings(fdt);
 	err = _blob_splice_string(fdt, len);
 	if (err)
-		return -err;
+		return err;
 
 	memcpy(new, s, len);
 	return (new - strtab);
@@ -125,7 +125,7 @@ static int _resize_property(void *fdt, int nodeoffset, const char *name, int len
 
 	*prop = fdt_get_property(fdt, nodeoffset, name, &oldlen);
 	if (! (*prop))
-		return -oldlen;
+		return oldlen;
 
 	if ((err = _blob_splice_struct(fdt, (*prop)->data,
 				       ALIGN(oldlen, FDT_TAGSIZE),
@@ -147,11 +147,11 @@ static int _add_property(void *fdt, int nodeoffset, const char *name, int len,
 
 	tag = _fdt_next_tag(fdt, nodeoffset, &nextoffset);
 	if (tag != FDT_BEGIN_NODE)
-		return FDT_ERR_BADOFFSET;
+		return -FDT_ERR_BADOFFSET;
 
 	namestroff = _find_add_string(fdt, name);
 	if (namestroff < 0)
-		return -namestroff;
+		return namestroff;
 
 	*prop = _fdt_offset_ptr(fdt, nextoffset);
 	proplen = sizeof(**prop) + ALIGN(len, FDT_TAGSIZE);
@@ -176,7 +176,7 @@ int fdt_setprop(void *fdt, int nodeoffset, const char *name,
 		return err;
 
 	err = _resize_property(fdt, nodeoffset, name, len, &prop);
-	if (err == FDT_ERR_NOTFOUND)
+	if (err == -FDT_ERR_NOTFOUND)
 		err = _add_property(fdt, nodeoffset, name, len, &prop);
 	if (err)
 		return err;
@@ -190,11 +190,11 @@ int fdt_delprop(void *fdt, int nodeoffset, const char *name)
 	struct fdt_property *prop;
 	int len, proplen;
 
-	RW_OFFSET_CHECK_HEADER(fdt);
+	RW_CHECK_HEADER(fdt);
 
 	prop = fdt_get_property(fdt, nodeoffset, name, &len);
 	if (! prop)
-		return -len;
+		return len;
 
 	proplen = sizeof(*prop) + ALIGN(len, FDT_TAGSIZE);
 	return _blob_splice_struct(fdt, prop, proplen, 0);
@@ -210,13 +210,13 @@ int fdt_add_subnode_namelen(void *fdt, int parentoffset,
 	uint32_t tag;
 	uint32_t *endtag;
 
-	RW_OFFSET_CHECK_HEADER(fdt);
+	RW_CHECK_HEADER(fdt);
 
 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
-	if ((err = fdt_offset_error(offset)) == 0)
-		return OFFSET_ERROR(FDT_ERR_EXISTS);
-	else if (err != FDT_ERR_NOTFOUND)
-		return OFFSET_ERROR(err);
+	if (offset >= 0)
+		return -FDT_ERR_EXISTS;
+	else if (offset != -FDT_ERR_NOTFOUND)
+		return offset;
 
 	/* Try to place the new node after the parent's properties */
 	_fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
@@ -230,7 +230,7 @@ int fdt_add_subnode_namelen(void *fdt, int parentoffset,
 
 	err = _blob_splice_struct(fdt, nh, 0, nodelen);
 	if (err)
-		return OFFSET_ERROR(err);
+		return err;
 
 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
 	memset(nh->name, 0, ALIGN(namelen+1, FDT_TAGSIZE));
@@ -249,11 +249,10 @@ int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
 int fdt_del_node(void *fdt, int nodeoffset)
 {
 	int endoffset;
-	int err;
 
 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
-	if ((err = fdt_offset_error(endoffset)))
-		return err;
+	if (endoffset < 0)
+		return endoffset;
 
 	return _blob_splice_struct(fdt, _fdt_offset_ptr(fdt, nodeoffset),
 				   endoffset - nodeoffset, 0);
@@ -277,7 +276,7 @@ int fdt_open_into(void *fdt, void *buf, int bufsize)
 	if (err)
 		return err;
 
-	return FDT_ERR_OK;
+	return 0;
 }
 
 int fdt_pack(void *fdt)
@@ -290,5 +289,5 @@ int fdt_pack(void *fdt)
 
 	/* FIXME: pack components */
 	fdt_set_header(fdt, totalsize, _blob_data_size(fdt));
-	return FDT_ERR_OK;
+	return 0;
 }

fdt_sw.c

@@ -26,7 +26,7 @@
 static int check_header_sw(void *fdt)
 {
 	if (fdt_magic(fdt) != SW_MAGIC)
-		return FDT_ERR_BADMAGIC;
+		return -FDT_ERR_BADMAGIC;
 	return 0;
 }
 
@@ -50,7 +50,7 @@ int fdt_create(void *buf, int bufsize)
 	void *fdt = buf;
 
 	if (bufsize < sizeof(struct fdt_header))
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 
 	memset(buf, 0, bufsize);
 
@@ -64,7 +64,7 @@ int fdt_create(void *buf, int bufsize)
 	fdt_set_header(fdt, off_dt_struct, fdt_off_mem_rsvmap(fdt));
 	fdt_set_header(fdt, off_dt_strings, bufsize);
 
-	return FDT_ERR_OK;
+	return 0;
 }
 
 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
@@ -76,11 +76,11 @@ int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
 	if (err)
 		return err;
 	if (fdt_size_dt_struct(fdt))
-		return FDT_ERR_BADSTATE;
+		return -FDT_ERR_BADSTATE;
 
 	offset = fdt_off_dt_struct(fdt);
 	if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 
 	re = (struct fdt_reserve_entry *)((void *)fdt + offset);
 	re->address = cpu_to_fdt64(addr);
@@ -107,7 +107,7 @@ int fdt_begin_node(void *fdt, const char *name)
 
 	nh = grab_space(fdt, sizeof(*nh) + ALIGN(namelen, FDT_TAGSIZE));
 	if (! nh)
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 
 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
 	memcpy(nh->name, name, namelen);
@@ -124,7 +124,7 @@ int fdt_end_node(void *fdt)
 
 	en = grab_space(fdt, FDT_TAGSIZE);
 	if (! en)
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 
 	*en = cpu_to_fdt32(FDT_END_NODE);
 	return 0;
@@ -164,11 +164,11 @@ int fdt_property(void *fdt, const char *name, const void *val, int len)
 
 	nameoff = find_add_string(fdt, name);
 	if (nameoff == 0)
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 
 	prop = grab_space(fdt, sizeof(*prop) + ALIGN(len, FDT_TAGSIZE));
 	if (! prop)
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 
 	prop->tag = cpu_to_fdt32(FDT_PROP);
 	prop->nameoff = cpu_to_fdt32(nameoff);
@@ -192,7 +192,7 @@ int fdt_finish(void *fdt)
 	/* Add terminator */
 	end = grab_space(fdt, sizeof(*end));
 	if (! end)
-		return FDT_ERR_NOSPACE;
+		return -FDT_ERR_NOSPACE;
 	*end = cpu_to_fdt32(FDT_END);
 
 	/* Relocate the string table */
@@ -210,7 +210,7 @@ int fdt_finish(void *fdt)
 			int nameoff;
 
 			if (! prop)
-				return FDT_ERR_BADSTRUCTURE;
+				return -FDT_ERR_BADSTRUCTURE;
 
 			nameoff = fdt32_to_cpu(prop->nameoff);
 			nameoff += fdt_size_dt_strings(fdt);

fdt_wip.c

@@ -31,10 +31,10 @@ int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
 
 	propval = fdt_getprop(fdt, nodeoffset, name, &proplen);
 	if (! propval)
-		return -proplen;
+		return proplen;
 
 	if (proplen != len)
-		return FDT_ERR_SIZE_MISMATCH;
+		return -FDT_ERR_SIZE_MISMATCH;
 
 	memcpy(propval, val, len);
 	return 0;
@@ -55,7 +55,7 @@ int fdt_nop_property(void *fdt, int nodeoffset, const char *name)
 
 	prop = fdt_get_property(fdt, nodeoffset, name, &len);
 	if (! prop)
-		return -len;
+		return len;
 
 	nop_region(prop, len + sizeof(*prop));
 
@@ -70,7 +70,7 @@ int _fdt_node_end_offset(void *fdt, int nodeoffset)
 
 	tag = _fdt_next_tag(fdt, nodeoffset, &nextoffset);
 	if (tag != FDT_BEGIN_NODE)
-		return FDT_ERR_BADOFFSET;
+		return -FDT_ERR_BADOFFSET;
 	do {
 		offset = nextoffset;
 		tag = _fdt_next_tag(fdt, offset, &nextoffset);
@@ -92,7 +92,7 @@ int _fdt_node_end_offset(void *fdt, int nodeoffset)
 			break;
 
 		default:
-			return FDT_ERR_BADSTRUCTURE;
+			return -FDT_ERR_BADSTRUCTURE;
 		}
 	} while (level >= 0);
 
@@ -102,11 +102,10 @@ int _fdt_node_end_offset(void *fdt, int nodeoffset)
 int fdt_nop_node(void *fdt, int nodeoffset)
 {
 	int endoffset;
-	int err;
 
 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
-	if ((err = fdt_offset_error(endoffset)))
-		return err;
+	if (endoffset < 0)
+		return endoffset;
 
 	nop_region(fdt_offset_ptr(fdt, nodeoffset, 0), endoffset - nodeoffset);
 	return 0;

libfdt.h

@@ -66,12 +66,6 @@ void *fdt_offset_ptr(const void *fdt, int offset, int checklen);
 #define fdt_offset_ptr_typed(fdt, offset, var) \
 	((typeof(var))(fdt_offset_ptr((fdt), (offset), sizeof(*(var)))))
 
-#define fdt_offset_error(offset) \
-	( (offset) < 0 ? -(offset) : 0 )
-
-#define fdt_ptrlen_error(p, len) \
-	( (p) ? 0 : -(len) )
-
 int fdt_move(const void *fdt, void *buf, int bufsize);
 
 /* Read-only functions */

libfdt_internal.h

@@ -36,8 +36,6 @@ static inline void *_fdt_offset_ptr(const struct fdt_header *fdt, int offset)
 	return (void *)fdt + fdt_off_dt_struct(fdt) + offset;
 }
 
-#define OFFSET_ERROR(code)	-(code)
-
 #define SW_MAGIC		(~FDT_MAGIC)
 
 #endif /* _LIBFDT_INTERNAL_H */

tests/del_node.c

@@ -42,19 +42,21 @@ int main(int argc, char *argv[])
 	oldsize = fdt_totalsize(fdt);
 
 	subnode1_offset = fdt_path_offset(fdt, "/subnode1");
-	if ((err = fdt_offset_error(subnode1_offset)))
-		FAIL("Couldn't find \"/subnode1\": %s", fdt_strerror(err));
+	if (subnode1_offset < 0)
+		FAIL("Couldn't find \"/subnode1\": %s",
+		     fdt_strerror(subnode1_offset));
 	check_getprop_typed(fdt, subnode1_offset, "prop-int", TEST_VALUE_1);
 
 	subnode2_offset = fdt_path_offset(fdt, "/subnode2");
-	if ((err = fdt_offset_error(subnode2_offset)))
-		FAIL("Couldn't find \"/subnode2\": %s", fdt_strerror(err));
+	if (subnode2_offset < 0)
+		FAIL("Couldn't find \"/subnode2\": %s",
+		     fdt_strerror(subnode2_offset));
 	check_getprop_typed(fdt, subnode2_offset, "prop-int", TEST_VALUE_2);
 
 	subsubnode2_offset = fdt_path_offset(fdt, "/subnode2/subsubnode");
-	if ((err = fdt_offset_error(subsubnode2_offset)))
+	if (subsubnode2_offset < 0)
 		FAIL("Couldn't find \"/subnode2/subsubnode\": %s",
-		     fdt_strerror(err));
+		     fdt_strerror(subsubnode2_offset));
 	check_getprop_typed(fdt, subsubnode2_offset, "prop-int", TEST_VALUE_2);
 
 	err = fdt_del_node(fdt, subnode1_offset);
@@ -62,19 +64,21 @@ int main(int argc, char *argv[])
 		FAIL("fdt_del_node(subnode1): %s", fdt_strerror(err));
 
 	subnode1_offset = fdt_path_offset(fdt, "/subnode1");
-	if ((err = fdt_offset_error(subnode1_offset)) != FDT_ERR_NOTFOUND)
+	if (subnode1_offset != -FDT_ERR_NOTFOUND)
 		FAIL("fdt_path_offset(subnode1) returned \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_NOTFOUND));
+		     fdt_strerror(subnode1_offset),
+		     fdt_strerror(-FDT_ERR_NOTFOUND));
 
 	subnode2_offset = fdt_path_offset(fdt, "/subnode2");
-	if ((err = fdt_offset_error(subnode2_offset)))
-		FAIL("Couldn't find \"/subnode2\": %s", fdt_strerror(err));
+	if (subnode2_offset < 0)
+		FAIL("Couldn't find \"/subnode2\": %s",
+		     fdt_strerror(subnode2_offset));
 	check_getprop_typed(fdt, subnode2_offset, "prop-int", TEST_VALUE_2);
 
 	subsubnode2_offset = fdt_path_offset(fdt, "/subnode2/subsubnode");
-	if ((err = fdt_offset_error(subsubnode2_offset)))
+	if (subsubnode2_offset < 0)
 		FAIL("Couldn't find \"/subnode2/subsubnode\": %s",
-		     fdt_strerror(err));
+		     fdt_strerror(subsubnode2_offset));
 	check_getprop_typed(fdt, subsubnode2_offset, "prop-int", TEST_VALUE_2);
 
 	err = fdt_del_node(fdt, subnode2_offset);
@@ -82,19 +86,22 @@ int main(int argc, char *argv[])
 		FAIL("fdt_del_node(subnode2): %s", fdt_strerror(err));
 
 	subnode1_offset = fdt_path_offset(fdt, "/subnode1");
-	if ((err = fdt_offset_error(subnode1_offset)) != FDT_ERR_NOTFOUND)
+	if (subnode1_offset != -FDT_ERR_NOTFOUND)
 		FAIL("fdt_path_offset(subnode1) returned \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_NOTFOUND));
+		     fdt_strerror(subnode1_offset),
+		     fdt_strerror(-FDT_ERR_NOTFOUND));
 
 	subnode2_offset = fdt_path_offset(fdt, "/subnode2");
-	if ((err = fdt_offset_error(subnode2_offset)) != FDT_ERR_NOTFOUND)
+	if (subnode2_offset != -FDT_ERR_NOTFOUND)
 		FAIL("fdt_path_offset(subnode2) returned \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_NOTFOUND));
+		     fdt_strerror(subnode2_offset),
+		     fdt_strerror(-FDT_ERR_NOTFOUND));
 
 	subsubnode2_offset = fdt_path_offset(fdt, "/subnode2/subsubnode");
-	if ((err = fdt_offset_error(subsubnode2_offset)) != FDT_ERR_NOTFOUND)
+	if (subsubnode2_offset != -FDT_ERR_NOTFOUND)
 		FAIL("fdt_path_offset(subsubnode2) returned \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_NOTFOUND));
+		     fdt_strerror(subsubnode2_offset),
+		     fdt_strerror(-FDT_ERR_NOTFOUND));
 
 	delsize = fdt_totalsize(fdt);
 

tests/del_property.c

@@ -52,8 +52,9 @@ int main(int argc, char *argv[])
 	intp = fdt_getprop(fdt, 0, "prop-int", &lenerr);
 	if (intp)
 		FAIL("prop-int still present after deletion");
-	if ((err = fdt_ptrlen_error(intp, lenerr)) != FDT_ERR_NOTFOUND)
-		FAIL("Unexpected error on second getprop: %s", fdt_strerror(err));
+	if (lenerr != -FDT_ERR_NOTFOUND)
+		FAIL("Unexpected error on second getprop: %s",
+		     fdt_strerror(lenerr));
 
 	strp = check_getprop(fdt, 0, "prop-str", strlen(TEST_STRING_1)+1,
 			     TEST_STRING_1);
@@ -65,8 +66,9 @@ int main(int argc, char *argv[])
 	strp = fdt_getprop(fdt, 0, "prop-str", &lenerr);
 	if (strp)
 		FAIL("prop-str still present after deletion");
-	if ((err = fdt_ptrlen_error(strp, lenerr)) != FDT_ERR_NOTFOUND)
-		FAIL("Unexpected error on second getprop: %s", fdt_strerror(err));
+	if (lenerr != -FDT_ERR_NOTFOUND)
+		FAIL("Unexpected error on second getprop: %s",
+		     fdt_strerror(lenerr));
 
 	delsize = fdt_totalsize(fdt);
 

tests/nop_node.c

@@ -39,19 +39,21 @@ int main(int argc, char *argv[])
 	fdt = load_blob_arg(argc, argv);
 
 	subnode1_offset = fdt_path_offset(fdt, "/subnode1");
-	if ((err = fdt_offset_error(subnode1_offset)))
-		FAIL("Couldn't find \"/subnode1\": %s", fdt_strerror(err));
+	if (subnode1_offset < 0)
+		FAIL("Couldn't find \"/subnode1\": %s",
+		     fdt_strerror(subnode1_offset));
 	check_getprop_typed(fdt, subnode1_offset, "prop-int", TEST_VALUE_1);
 
 	subnode2_offset = fdt_path_offset(fdt, "/subnode2");
-	if ((err = fdt_offset_error(subnode2_offset)))
-		FAIL("Couldn't find \"/subnode2\": %s", fdt_strerror(err));
+	if (subnode2_offset < 0)
+		FAIL("Couldn't find \"/subnode2\": %s",
+		     fdt_strerror(subnode2_offset));
 	check_getprop_typed(fdt, subnode2_offset, "prop-int", TEST_VALUE_2);
 
 	subsubnode2_offset = fdt_path_offset(fdt, "/subnode2/subsubnode");
-	if ((err = fdt_offset_error(subsubnode2_offset)))
+	if (subsubnode2_offset < 0)
 		FAIL("Couldn't find \"/subnode2/subsubnode\": %s",
-		     fdt_strerror(err));
+		     fdt_strerror(subsubnode2_offset));
 	check_getprop_typed(fdt, subsubnode2_offset, "prop-int", TEST_VALUE_2);
 
 	err = fdt_nop_node(fdt, subnode1_offset);
@@ -59,19 +61,21 @@ int main(int argc, char *argv[])
 		FAIL("fdt_nop_node(subnode1): %s", fdt_strerror(err));
 
 	subnode1_offset = fdt_path_offset(fdt, "/subnode1");
-	if ((err = fdt_offset_error(subnode1_offset)) != FDT_ERR_NOTFOUND)
+	if (subnode1_offset != -FDT_ERR_NOTFOUND)
 		FAIL("fdt_path_offset(subnode1) returned \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_NOTFOUND));
+		     fdt_strerror(subnode1_offset),
+		     fdt_strerror(-FDT_ERR_NOTFOUND));
 
 	subnode2_offset = fdt_path_offset(fdt, "/subnode2");
-	if ((err = fdt_offset_error(subnode2_offset)))
-		FAIL("Couldn't find \"/subnode2\": %s", fdt_strerror(err));
+	if (subnode2_offset < 0)
+		FAIL("Couldn't find \"/subnode2\": %s",
+		     fdt_strerror(subnode2_offset));
 	check_getprop_typed(fdt, subnode2_offset, "prop-int", TEST_VALUE_2);
 
 	subsubnode2_offset = fdt_path_offset(fdt, "/subnode2/subsubnode");
-	if ((err = fdt_offset_error(subsubnode2_offset)))
+	if (subsubnode2_offset < 0)
 		FAIL("Couldn't find \"/subnode2/subsubnode\": %s",
-		     fdt_strerror(err));
+		     fdt_strerror(subsubnode2_offset));
 	check_getprop_typed(fdt, subsubnode2_offset, "prop-int", TEST_VALUE_2);
 
 	err = fdt_nop_node(fdt, subnode2_offset);
@@ -79,19 +83,22 @@ int main(int argc, char *argv[])
 		FAIL("fdt_nop_node(subnode2): %s", fdt_strerror(err));
 
 	subnode1_offset = fdt_path_offset(fdt, "/subnode1");
-	if ((err = fdt_offset_error(subnode1_offset)) != FDT_ERR_NOTFOUND)
+	if (subnode1_offset != -FDT_ERR_NOTFOUND)
 		FAIL("fdt_path_offset(subnode1) returned \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_NOTFOUND));
+		     fdt_strerror(subnode1_offset),
+		     fdt_strerror(-FDT_ERR_NOTFOUND));
 
 	subnode2_offset = fdt_path_offset(fdt, "/subnode2");
-	if ((err = fdt_offset_error(subnode2_offset)) != FDT_ERR_NOTFOUND)
+	if (subnode2_offset != -FDT_ERR_NOTFOUND)
 		FAIL("fdt_path_offset(subnode2) returned \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_NOTFOUND));
+		     fdt_strerror(subnode2_offset),
+		     fdt_strerror(-FDT_ERR_NOTFOUND));
 
 	subsubnode2_offset = fdt_path_offset(fdt, "/subnode2/subsubnode");
-	if ((err = fdt_offset_error(subsubnode2_offset)) != FDT_ERR_NOTFOUND)
+	if (subsubnode2_offset != -FDT_ERR_NOTFOUND)
 		FAIL("fdt_path_offset(subsubnode2) returned \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_NOTFOUND));
+		     fdt_strerror(subsubnode2_offset),
+		     fdt_strerror(-FDT_ERR_NOTFOUND));
 
 	PASS();
 }

tests/nop_property.c

@@ -50,7 +50,7 @@ int main(int argc, char *argv[])
 	intp = fdt_getprop(fdt, 0, "prop-int", &lenerr);
 	if (intp)
 		FAIL("prop-int still present after nopping");
-	if ((err = fdt_ptrlen_error(intp, lenerr)) != FDT_ERR_NOTFOUND)
+	if (lenerr != -FDT_ERR_NOTFOUND)
 		FAIL("Unexpected error on second getprop: %s", fdt_strerror(err));
 	
 	strp = check_getprop(fdt, 0, "prop-str", strlen(TEST_STRING_1)+1,
@@ -63,7 +63,7 @@ int main(int argc, char *argv[])
 	strp = fdt_getprop(fdt, 0, "prop-str", &lenerr);
 	if (strp)
 		FAIL("prop-str still present after nopping");
-	if ((err = fdt_ptrlen_error(strp, lenerr)) != FDT_ERR_NOTFOUND)
+	if (lenerr != -FDT_ERR_NOTFOUND)
 		FAIL("Unexpected error on second getprop: %s", fdt_strerror(err));
 
 	PASS();

tests/notfound.c

@@ -29,8 +29,8 @@
 
 void check_error(const char *s, int err)
 {
-	if (err != FDT_ERR_NOTFOUND)
-		FAIL("%s return error %s instead of FDT_ERR_NOTFOUND", s,
+	if (err != -FDT_ERR_NOTFOUND)
+		FAIL("%s return error %s instead of -FDT_ERR_NOTFOUND", s,
 		     fdt_strerror(err));
 }
 
@@ -41,38 +41,32 @@ int main(int argc, char *argv[])
 	int offset;
 	int subnode1_offset;
 	void *val;
-	int err;
 	int lenerr;
 
 	test_init(argc, argv);
 	fdt = load_blob_arg(argc, argv);
 
 	prop = fdt_get_property(fdt, 0, "nonexistant-property", &lenerr);
-	check_error("fdt_get_property(\"nonexistant-property\")",
-		    fdt_ptrlen_error(prop, lenerr));
+	check_error("fdt_get_property(\"nonexistant-property\")", lenerr);
 
 	val = fdt_getprop(fdt, 0, "nonexistant-property", &lenerr);
-	check_error("fdt_getprop(\"nonexistant-property\"",
-		    fdt_ptrlen_error(val, lenerr));
+	check_error("fdt_getprop(\"nonexistant-property\"", lenerr);
 
 	subnode1_offset = fdt_subnode_offset(fdt, 0, "subnode1");
-	if ((err = fdt_offset_error(subnode1_offset)))
-		FAIL("Couldn't find subnode1: %s", fdt_strerror(err));
+	if (subnode1_offset < 0)
+		FAIL("Couldn't find subnode1: %s", fdt_strerror(subnode1_offset));
 
 	val = fdt_getprop(fdt, subnode1_offset, "prop-str", &lenerr);
-	check_error("fdt_getprop(\"prop-str\")", fdt_ptrlen_error(val, lenerr));
+	check_error("fdt_getprop(\"prop-str\")", lenerr);
 
 	offset = fdt_subnode_offset(fdt, 0, "nonexistant-subnode");
-	check_error("fdt_subnode_offset(\"nonexistant-subnode\")",
-		    fdt_offset_error(offset));
+	check_error("fdt_subnode_offset(\"nonexistant-subnode\")", offset);
 
 	offset = fdt_subnode_offset(fdt, 0, "subsubnode");
-	check_error("fdt_subnode_offset(\"subsubnode\")",
-		    fdt_offset_error(offset));
+	check_error("fdt_subnode_offset(\"subsubnode\")", offset);
 
 	offset = fdt_path_offset(fdt, "/nonexistant-subnode");
-	check_error("fdt_path_offset(\"/nonexistant-subnode\")",
-		    fdt_offset_error(offset));
+	check_error("fdt_path_offset(\"/nonexistant-subnode\")", offset);
 	
 	PASS();
 }

tests/path_offset.c

@@ -30,15 +30,14 @@
 int check_subnode(void *fdt, int parent, const char *name)
 {
 	int offset;
-	int err;
 	struct fdt_node_header *nh;
 	uint32_t tag;
 
 	verbose_printf("Checking subnode \"%s\" of %d...", name, parent);
 	offset = fdt_subnode_offset(fdt, parent, name);
 	verbose_printf("offset %d...", offset);
-	if ((err = fdt_offset_error(offset)))
-		FAIL("fdt_subnode_offset(\"%s\"): %s", name, fdt_strerror(err));
+	if (offset < 0)
+		FAIL("fdt_subnode_offset(\"%s\"): %s", name, fdt_strerror(offset));
 	nh = fdt_offset_ptr_typed(fdt, offset, nh);
 	verbose_printf("pointer %p\n", nh);
 	if (! nh)

tests/rw_tree1.c

@@ -40,9 +40,9 @@
 
 #define OFF_CHECK(off, code) \
 	{ \
-		err = fdt_offset_error((off) = (code)); \
-		if (err) \
-			FAIL(#code ": %s", fdt_strerror(err)); \
+		(off) = (code); \
+		if (off < 0) \
+			FAIL(#code ": %s", fdt_strerror(off)); \
 	}
 
 int main(int argc, char *argv[])

tests/subnode_offset.c

@@ -30,15 +30,14 @@
 int check_subnode(struct fdt_header *fdt, int parent, const char *name)
 {
 	int offset;
-	int err;
 	struct fdt_node_header *nh;
 	uint32_t tag;
 
 	verbose_printf("Checking subnode \"%s\" of %d...", name, parent);
 	offset = fdt_subnode_offset(fdt, parent, name);
 	verbose_printf("offset %d...", offset);
-	if ((err = fdt_offset_error(offset)))
-		FAIL("fdt_subnode_offset(\"%s\"): %s", name, fdt_strerror(err));
+	if (offset < 0)
+		FAIL("fdt_subnode_offset(\"%s\"): %s", name, fdt_strerror(offset));
 	nh = fdt_offset_ptr_typed(fdt, offset, nh);
 	verbose_printf("pointer %p\n", nh);
 	if (! nh)

tests/testutils.c

@@ -97,10 +97,12 @@ static struct errtabent errtable[] = {
 
 const char *fdt_strerror(int errval)
 {
-	if ((errval >= 0) && (errval < ERRTABSIZE))
-		return errtable[errval].str;
+	if (errval > 0)
+		return "<valid offset>";
+	else if (errval < -ERRTABSIZE)
+		return "<unknown error>";
 	else
-		return "Unknown FDT error code";
+		return errtable[-errval].str;
 }
 
 void check_property(void *fdt, int nodeoffset, const char *name,

tests/truncated_property.c

@@ -40,10 +40,9 @@ int main(int argc, char *argv[])
 	prop = fdt_getprop(fdt, 0, "truncated", &len);
 	if (prop)
 		FAIL("fdt_getprop() succeeded on truncated property");
-	err = fdt_ptrlen_error(prop, len);
-	if (err != FDT_ERR_BADSTRUCTURE)
+	if (len != -FDT_ERR_BADSTRUCTURE)
 		FAIL("fdt_getprop() failed with \"%s\" instead of \"%s\"",
-		     fdt_strerror(err), fdt_strerror(FDT_ERR_BADSTRUCTURE));
+		     fdt_strerror(err), fdt_strerror(-FDT_ERR_BADSTRUCTURE));
 
 	PASS();
 }