fdt: Fix parent pointer being set to temporary memory

1 files changed, 27 insertions, 16 deletions

diff --git a/src/fdt.zig b/src/fdt.zig
index 4fa47b3..b4fae6c 100644
--- a/src/fdt.zig
+++ b/src/fdt.zig
@@ -223,12 +223,14 @@ pub const Header = struct {
         const dt_strings: [*:0]const u8 = @ptrFromInt(dt_strings_addr);
 
         while (std.mem.bigToNative(u32, @as(*u32, @ptrFromInt(dt_struct_addr)).*) != token_end) {
-            const parsed = try parseNode(allocator, dt_struct_addr, dt_strings, null);
+            const parsed = try parseNode(allocator, dt_struct_addr, dt_strings);
             dt_struct_addr = parsed.addr;
             try nodes.insert(0, parsed.value);
         }
 
-        return .{ .nodes = nodes };
+        var tree = Tree{ .nodes = nodes };
+        initParentPtrs(&tree);
+        return tree;
     }
 };
 
@@ -286,7 +288,7 @@ fn nodeNameFilter(node: Node, name: []const u8) bool {
     return std.mem.eql(u8, trueName, name);
 }
 
-fn parseNode(allocator: std.mem.Allocator, dt_struct_addr: usize, dt_strings: [*:0]const u8, parent: ?*Node) !ParseResult(Node) {
+fn parseNode(allocator: std.mem.Allocator, dt_struct_addr: usize, dt_strings: [*:0]const u8) !ParseResult(Node) {
     var props = std.StringHashMap([]const u8).init(allocator);
     var subnodes = std.ArrayList(Node).init(allocator);
 
@@ -326,7 +328,7 @@ fn parseNode(allocator: std.mem.Allocator, dt_struct_addr: usize, dt_strings: [*
             // Skip Nop tokens
             Header.token_nop => addr += @sizeOf(u32),
             Header.token_begin_node => {
-                const parsed = try parseNode(allocator, addr, dt_strings, null);
+                const parsed = try parseNode(allocator, addr, dt_strings);
                 addr = parsed.addr;
                 try subnodes.insert(0, parsed.value);
             },
@@ -336,20 +338,14 @@ fn parseNode(allocator: std.mem.Allocator, dt_struct_addr: usize, dt_strings: [*
 
     addr += @sizeOf(u32);
 
-    var self: Node = .{
-        .name = std.mem.span(name),
-        .props = props,
-        .parent = parent,
-        .subnodes = subnodes,
-    };
-
-    for (0..self.subnodes.items.len) |i| {
-        self.subnodes.items[i].parent = &self;
-    }
-
     return .{
         .addr = addr,
-        .value = self,
+        .value = .{
+            .name = std.mem.span(name),
+            .props = props,
+            .parent = null,
+            .subnodes = subnodes,
+        },
     };
 }
 
@@ -388,3 +384,18 @@ fn parseProperty(dt_struct_addr: usize, dt_strings: [*:0]const u8) !ParseResult(
         },
     };
 }
+
+fn initParentPtrs(dt: *Tree) void {
+    for (dt.nodes.items, 0..) |_, i| {
+        for (dt.nodes.items[i].subnodes.items, 0..) |_, j| {
+            initParentPtrsRecursive(&dt.nodes.items[i].subnodes.items[j], &dt.nodes.items[i]);
+        }
+    }
+}
+
+fn initParentPtrsRecursive(node: *Node, parent: *Node) void {
+    node.parent = parent;
+    for (node.subnodes.items, 0..) |_, i| {
+        initParentPtrsRecursive(&node.subnodes.items[i], node);
+    }
+}