feat(libfdt): upgrade libfdt source files

Update the libfdt source files to the upstream commit e37c256 [1].

[1] https://github.com/dgibson/dtc/commit/e37c256

Change-Id: I00e29b467ff6f8c094f68245232a7cedeaa14aef
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>
diff --git a/lib/libfdt/fdt_rw.c b/lib/libfdt/fdt_rw.c
index 68887b9..3621d36 100644
--- a/lib/libfdt/fdt_rw.c
+++ b/lib/libfdt/fdt_rw.c
@@ -349,7 +349,10 @@
 		return offset;
 
 	/* Try to place the new node after the parent's properties */
-	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
+	tag = fdt_next_tag(fdt, parentoffset, &nextoffset);
+	/* the fdt_subnode_offset_namelen() should ensure this never hits */
+	if (!can_assume(LIBFDT_FLAWLESS) && (tag != FDT_BEGIN_NODE))
+		return -FDT_ERR_INTERNAL;
 	do {
 		offset = nextoffset;
 		tag = fdt_next_tag(fdt, offset, &nextoffset);
@@ -391,7 +394,9 @@
 }
 
 static void fdt_packblocks_(const char *old, char *new,
-			    int mem_rsv_size, int struct_size)
+			    int mem_rsv_size,
+			    int struct_size,
+			    int strings_size)
 {
 	int mem_rsv_off, struct_off, strings_off;
 
@@ -406,8 +411,7 @@
 	fdt_set_off_dt_struct(new, struct_off);
 	fdt_set_size_dt_struct(new, struct_size);
 
-	memmove(new + strings_off, old + fdt_off_dt_strings(old),
-		fdt_size_dt_strings(old));
+	memmove(new + strings_off, old + fdt_off_dt_strings(old), strings_size);
 	fdt_set_off_dt_strings(new, strings_off);
 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
 }
@@ -428,12 +432,14 @@
 
 	if (can_assume(LATEST) || fdt_version(fdt) >= 17) {
 		struct_size = fdt_size_dt_struct(fdt);
-	} else {
+	} else if (fdt_version(fdt) == 16) {
 		struct_size = 0;
 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
 			;
 		if (struct_size < 0)
 			return struct_size;
+	} else {
+		return -FDT_ERR_BADVERSION;
 	}
 
 	if (can_assume(LIBFDT_ORDER) ||
@@ -465,7 +471,8 @@
 			return -FDT_ERR_NOSPACE;
 	}
 
-	fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size);
+	fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size,
+			fdt_size_dt_strings(fdt));
 	memmove(buf, tmp, newsize);
 
 	fdt_set_magic(buf, FDT_MAGIC);
@@ -485,7 +492,8 @@
 
 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
 		* sizeof(struct fdt_reserve_entry);
-	fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
+	fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt),
+			fdt_size_dt_strings(fdt));
 	fdt_set_totalsize(fdt, fdt_data_size_(fdt));
 
 	return 0;