1 files changed, 71 insertions, 0 deletions
diff --git a/js/xpconnect/tests/unit/test_xray_SavedFrame-02.js b/js/xpconnect/tests/unit/test_xray_SavedFrame-02.js
new file mode 100644
index 0000000000..e9b5752044
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_xray_SavedFrame-02.js
@@ -0,0 +1,71 @@
+// Test calling SavedFrame getters across wrappers from privileged and
+// un-privileged globals.
+
+const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
+addDebuggerToGlobal(globalThis);
+
+const lowP = Services.scriptSecurityManager.createNullPrincipal({});
+const highP = Cc["@mozilla.org/systemprincipal;1"].createInstance(Ci.nsIPrincipal);
+
+const low  = new Cu.Sandbox(lowP);
+const high = new Cu.Sandbox(highP);
+
+function run_test() {
+  // Privileged compartment accessing unprivileged stack.
+  high.stack = getSavedFrameInstanceFromSandbox(low);
+  Cu.evalInSandbox("this.parent = stack.parent", high);
+  Cu.evalInSandbox("this.asyncParent = stack.asyncParent", high);
+  Cu.evalInSandbox("this.source = stack.source", high);
+  Cu.evalInSandbox("this.functionDisplayName = stack.functionDisplayName", high);
+
+  // Un-privileged compartment accessing privileged stack.
+  low.stack = getSavedFrameInstanceFromSandbox(high);
+  try {
+    Cu.evalInSandbox("this.parent = stack.parent", low);
+  } catch (e) { }
+  try {
+    Cu.evalInSandbox("this.asyncParent = stack.asyncParent", low);
+  } catch (e) { }
+  try {
+    Cu.evalInSandbox("this.source = stack.source", low);
+  } catch (e) { }
+  try {
+    Cu.evalInSandbox("this.functionDisplayName = stack.functionDisplayName", low);
+  } catch (e) { }
+
+  // Privileged compartment accessing privileged stack.
+  let stack = getSavedFrameInstanceFromSandbox(high);
+  let parent = stack.parent;
+  let asyncParent = stack.asyncParent;
+  let source = stack.source;
+  let functionDisplayName = stack.functionDisplayName;
+
+  ok(true, "Didn't crash");
+}
+
+// Get a SavedFrame instance from inside the given sandbox.
+//
+// We can't use Cu.getJSTestingFunctions().saveStack() because Cu isn't
+// available to sandboxes that don't have the system principal. The easiest way
+// to get the SavedFrame is to use the Debugger API to track allocation sites
+// and then do an allocation.
+function getSavedFrameInstanceFromSandbox(sandbox) {
+  const dbg = new Debugger(sandbox);
+
+  dbg.memory.trackingAllocationSites = true;
+  Cu.evalInSandbox("(function iife() { return new RegExp }())", sandbox);
+  const allocs = dbg.memory.drainAllocationsLog().filter(e => e.class === "RegExp");
+  dbg.memory.trackingAllocationSites = false;
+
+  ok(allocs[0], "We should observe the allocation");
+  const { frame } = allocs[0];
+
+  if (sandbox !== high) {
+    ok(Cu.isXrayWrapper(frame), "`frame` should be an xray...");
+    equal(Object.prototype.toString.call(Cu.waiveXrays(frame)),
+          "[object SavedFrame]",
+          "...and that xray should wrap a SavedFrame");
+  }
+
+  return frame;
+}