libfdt: overlay_merge: remove resolved symbols
Merging two overlay blobs will involve merging contents of nodes such as
__symbols__. Not all properties need to be merged however at the end of merge
process. overlay_symbol_update() may already have updated base blob's
__symbols__ node to reflect new position of some nodes from overlay blob. Remove
such symbols from overlay blob's __symbols__ node, to prevent a subsequent merge
of __symbols__ node of both blobs from creating duplicate entries representing
same node.
Change-Id: I8ce45011db3f565d903ace922870a2c2616a560c
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
index 1491ccc..da27d69 100644
--- a/libfdt/fdt_overlay.c
+++ b/libfdt/fdt_overlay.c
@@ -855,6 +855,7 @@
* overlay_symbol_update - Update the symbols of base tree after a merge
* @fdt: Base Device Tree blob
* @fdto: Device tree overlay blob
+ * @merge: Both input blobs are overlay blobs that are being merged
*
* overlay_symbol_update() updates the symbols of the base tree with the
* symbols of the applied overlay
@@ -867,9 +868,9 @@
* 0 on success
* Negative error code on failure
*/
-static int overlay_symbol_update(void *fdt, void *fdto)
+static int overlay_symbol_update(void *fdt, void *fdto, int merge)
{
- int root_sym, ov_sym, prop, path_len, fragment, target;
+ int root_sym, ov_sym, prop, next_prop, path_len, fragment, target;
int len, frag_name_len, ret, rel_path_len;
const char *s, *e;
const char *path;
@@ -897,7 +898,12 @@
return root_sym;
/* iterate over each overlay symbol */
- fdt_for_each_property_offset(prop, fdto, ov_sym) {
+
+ /* Safeguard against property being possibly deleted in this loop */
+ prop = fdt_first_property_offset(fdto, ov_sym);
+ while (prop >= 0) {
+ next_prop = fdt_next_property_offset(fdto, prop);
+
path = fdt_getprop_by_offset(fdto, prop, &name, &path_len);
if (!path)
return path_len;
@@ -955,8 +961,14 @@
/* get the target of the fragment */
ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path);
- if (ret < 0)
+ if (ret < 0) {
+ if (ret == -FDT_ERR_BADPHANDLE && merge) {
+ prop = next_prop;
+ continue;
+ }
+
return ret;
+ }
target = ret;
/* if we have a target path use */
@@ -997,6 +1009,31 @@
buf[len] = '/';
memcpy(buf + len + 1, rel_path, rel_path_len);
buf[len + 1 + rel_path_len] = '\0';
+
+ /*
+ * In case of merging two overlay blobs, we will be merging
+ * contents of nodes such as __symbols__ from both overlay
+ * blobs. Delete this property in __symbols__ node of second
+ * overlay blob, as it has already been reflected in
+ * first/combined blob's __symbols__ node.
+ */
+ if (merge) {
+ ret = fdt_delprop(fdto, ov_sym, name);
+ if (ret < 0)
+ return ret;
+
+ /* Bail if this was the last property */
+ if (next_prop < 0)
+ break;
+
+ /*
+ * Continue with same 'prop' offset, as the next
+ * property is now available at the same offset
+ */
+ continue;
+ }
+
+ prop = next_prop;
}
return 0;
@@ -1030,7 +1067,7 @@
if (ret)
goto err;
- ret = overlay_symbol_update(fdt, fdto);
+ ret = overlay_symbol_update(fdt, fdto, 0);
if (ret)
goto err;
@@ -1383,7 +1420,7 @@
if (ret)
goto err;
- ret = overlay_symbol_update(fdt, fdto);
+ ret = overlay_symbol_update(fdt, fdto, 1);
if (ret)
goto err;