From: Ralf Jung <post@ralfj.de>
Date: Sat, 3 Dec 2022 12:33:00 +0000 (+0100)
Subject: interpret: clobber return place when calling function
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;h=51ac2af99ffd46cf83760ceef2404dad0ce238a9;p=rust.git

interpret: clobber return place when calling function
---

diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs
index 79450fccfc4..e17d3e516a6 100644
--- a/compiler/rustc_const_eval/src/interpret/eval_context.rs
+++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs
@@ -676,6 +676,10 @@ pub fn push_stack_frame(
         return_to_block: StackPopCleanup,
     ) -> InterpResult<'tcx> {
         trace!("body: {:#?}", body);
+        // Clobber previous return place contents, nobody is supposed to be able to see them any more
+        // This also checks dereferenceable, but not align. We rely on all constructed places being
+        // sufficiently aligned (in particular we rely on `deref_operand` checking alignment).
+        self.write_uninit(return_place)?;
         // first push a stack frame so we have access to the local substs
         let pre_frame = Frame {
             body,