Merge "Do tearDown iff we did setUp"
diff --git a/pvmfw/avb/src/lib.rs b/pvmfw/avb/src/lib.rs
index 8fea162..d83737f 100644
--- a/pvmfw/avb/src/lib.rs
+++ b/pvmfw/avb/src/lib.rs
@@ -15,8 +15,6 @@
 //! A library implementing the payload verification for pvmfw with libavb
 
 #![cfg_attr(not(test), no_std)]
-// For usize.checked_add_signed(isize), available in Rust 1.66.0
-#![feature(mixed_integer_ops)]
 
 mod descriptor;
 mod error;
diff --git a/vmbase/entry.S b/vmbase/entry.S
index ab46465..408f5d1 100644
--- a/vmbase/entry.S
+++ b/vmbase/entry.S
@@ -225,6 +225,9 @@
 	adr_l x30, __stack_chk_guard
 	str x29, [x30]
 
+	/* Write a null byte to the top of the stack guard to act as a string terminator. */
+	strb wzr, [x30]
+
 	/* Call into Rust code. */
 	bl rust_entry