Merge changes I1e5a8903,I43c6ad22,If9a102a6,I702e619c into main am: e5b8c171c5

Original change: https://android-review.googlesource.com/c/platform/external/dtc/+/2784253

Change-Id: I0afccef8cf1d66b917fb815c72692f047b7b7672
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

1 files changed, 19 insertions, 26 deletions

diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
index 53db8ce..09d92d4 100644
--- a/libfdt/fdt_ro.c
+++ b/libfdt/fdt_ro.c
@@ -10,14 +10,6 @@
 
 #include "libfdt_internal.h"
 
-/* Check if a buffer contains a nul-terminated string.
- * Used for checking property values which should be strings.
- */
-static bool is_nul_string(const char *buf, const size_t buf_len) {
-	return buf_len > 0 && buf[buf_len - 1] == '\0' &&
-		strnlen(buf, buf_len) == buf_len - 1;
-}
-
 static int fdt_nodename_eq_(const void *fdt, int offset,
 			    const char *s, int len)
 {
@@ -533,30 +525,31 @@ uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
 	return fdt32_ld_(php);
 }
 
+static const void *fdt_path_getprop_namelen(const void *fdt, const char *path,
+					    const char *propname, int propnamelen,
+					    int *lenp)
+{
+	int offset = fdt_path_offset(fdt, path);
+
+	if (offset < 0)
+		return NULL;
+
+	return fdt_getprop_namelen(fdt, offset, propname, propnamelen, lenp);
+}
+
 const char *fdt_get_alias_namelen(const void *fdt,
 				  const char *name, int namelen)
 {
-	const char *prop;
-	int aliasoffset;
-	int prop_len;
+	int len;
+	const char *alias;
 
-	aliasoffset = fdt_path_offset(fdt, "/aliases");
-	if (aliasoffset < 0)
-		return NULL;
+	alias = fdt_path_getprop_namelen(fdt, "/aliases", name, namelen, &len);
 
-	prop = fdt_getprop_namelen(fdt, aliasoffset, name, namelen, &prop_len);
-	if (prop && !can_assume(VALID_INPUT)) {
-		/* Validate the alias value.  From the devicetree spec v0.3:
-		 * "An alias value is a device path and is encoded as a string.
-		 *  The value representes the full path to a node, ..."
-		 * A full path must start at the root to prevent recursion.
-		 */
-		if (prop_len == 0 || *prop != '/' || !is_nul_string(prop, prop_len)) {
-			prop = NULL;
-		}
-	}
+	if (!can_assume(VALID_DTB) &&
+	    !(alias && len > 0 && alias[len - 1] == '\0' && *alias == '/'))
+		return NULL;
 
-	return prop;
+	return alias;
 }
 
 const char *fdt_get_alias(const void *fdt, const char *name)