tests: Correct fdt handling of overlays without fixups and base trees without symbols
The fdt_overlay_apply() function purports to support the edge cases where
an overlay has no fixups to be applied, or a base tree which has no
symbols (the latter can only work if the former is also true). However it
gets it wrong in a couple of small ways:
* In the no fixups case, it doesn't fail immediately, but will attempt
fdt_for_each_property_offset() giving -FDT_ERR_NOTFOUND as the node
offset, which will fail. Instead it should succeed immediately, since
there's nothing to do.
* In the case of no symbols, it again doesn't fail immediately. However
if there is an actual fixup it will fail with an unexpected error,
because -FDT_ERR_NOTFOUND is passed to fdt_getprop() when attempting to
look up the symbols. We should instead return -FDT_ERR_NOTFOUND
directly.
Both of these errors lead to the code returning misleading error codes in
failing cases.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
index bb41404..56cb70e 100644
--- a/libfdt/fdt_overlay.c
+++ b/libfdt/fdt_overlay.c
@@ -359,6 +359,9 @@
int symbol_off, fixup_off;
int prop_len;
+ if (symbols_off < 0)
+ return symbols_off;
+
symbol_path = fdt_getprop(fdt, symbols_off, label,
&prop_len);
if (!symbol_path)
@@ -492,7 +495,9 @@
/* We can have overlays without any fixups */
fixups_off = fdt_path_offset(fdto, "/__fixups__");
- if ((fixups_off < 0 && (fixups_off != -FDT_ERR_NOTFOUND)))
+ if (fixups_off == -FDT_ERR_NOTFOUND)
+ return 0; /* nothing to do */
+ if (fixups_off < 0)
return fixups_off;
/* And base DTs without symbols */
