Abort execution if miri_get_alloc_id doesn't have provenance

Author: saethlin

src/intptrcast.rs

@@ -65,7 +65,7 @@ impl GlobalStateInner {
 impl<'mir, 'tcx> GlobalStateInner {
     // Returns the exposed `AllocId` that corresponds to the specified addr,
     // or `None` if the addr is out of bounds
-    pub fn alloc_id_from_addr(ecx: &MiriInterpCx<'mir, 'tcx>, addr: u64) -> Option<AllocId> {
+    fn alloc_id_from_addr(ecx: &MiriInterpCx<'mir, 'tcx>, addr: u64) -> Option<AllocId> {
         let global_state = ecx.machine.intptrcast.borrow();
         assert!(global_state.provenance_mode != ProvenanceMode::Strict);
 

src/shims/foreign_items.rs

@@ -420,13 +420,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             "miri_get_alloc_id" => {
                 let [ptr] = this.check_shim(abi, Abi::Rust, link_name, args)?;
                 let ptr = this.read_pointer(ptr)?;
-                let (prov, offset) = ptr.into_parts();
+                let (prov, _offset) = ptr.into_parts();
                 let alloc_id = if prov.is_some() {
                     let (alloc_id, _, _) = this.ptr_get_alloc_id(ptr)?;
                     alloc_id
                 } else {
-                    intptrcast::GlobalStateInner::alloc_id_from_addr(this, offset.bytes())
-                        .expect("pointer passed to miri_get_alloc_id must not be dangling")
+                    throw_machine_stop!(TerminationInfo::Abort(
+                        format!("pointer passed to miri_get_alloc_id must not be dangling, got {:?}", ptr)
+                    ))
                 };
                 this.write_scalar(Scalar::from_u64(alloc_id.0.get()), dest)?;
             }

tests/pass/stacked-borrows/stack-printing.rs

@@ -42,10 +42,5 @@ fn main() {
     }
     print_borrow_stacks(alloc_id);
 
-    // Check that we get the right AllocId even if we pass a pointer with no provenance,
-    // so long as its address corresponds to an existing allocation.
-    let ptr_without_provenance = core::ptr::null::<u8>().with_addr(ptr.addr());
-    assert_eq!(get_alloc_id(ptr_without_provenance), alloc_id);
-
     unsafe { alloc::dealloc(ptr, Layout::new::<u8>()) };
 }