mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

CFI: Fix ICE in KCFI non-associated function pointers

Browse Source 
We oddly weren't testing the more usual case of casting non-methods to
function pointers. The KCFI shim insertion logic would ICE on these due
to asking for an irrefutable associated item if we cast a function to a
function pointer without needing a traditional shim.
This commit is contained in:
Matthew Maurer 2024-04-08 16:37:06 +00:00
parent ab3dba92db
commit 284da5d6b4
2 changed files with 10 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
compiler/rustc_middle/src/ty/instance.rs
View File

@ -520,7 +520,10 @@ pub fn resolve_for_fn_ptr(
// Reify `Trait::method` implementations if KCFI is enabled
// FIXME(maurer) only reify it if it is a vtable-safe function
_ if tcx.sess.is_sanitizer_kcfi_enabled()
&& tcx.associated_item(def_id).trait_item_def_id.is_some() =>
&& tcx
.opt_associated_item(def_id)
.and_then(|assoc| assoc.trait_item_def_id)
.is_some() =>
{
// If this function could also go in a vtable, we need to `ReifyShim` it with
// KCFI because it can only attach one type per function.

8
tests/ui/sanitizer/cfi-method-fn-ptr-cast.rs → tests/ui/sanitizer/cfi-fn-ptr.rs
View File

@ -1,4 +1,4 @@
// Verifies that casting a method to a function pointer works.
// Verifies that casting to a function pointer works.
//@ revisions: cfi kcfi
// FIXME(#122848) Remove only-linux once OSX CFI binaries work
@ -46,6 +46,8 @@ impl Trait1 for Type1 {
fn foo(&self) {}
}
fn foo<T>(_: &T) {}
fn main() {
let type1 = Type1 {};
let f = <Type1 as Trait1>::foo;
@ -53,5 +55,7 @@ fn main() {
// Check again with different optimization barriers
S2 { f: <S as Foo>::foo }.foo(&S);
// Check mismatched #[track_caller]
S2 { f: <S as Foo>::bar }.foo(&S)
S2 { f: <S as Foo>::bar }.foo(&S);
// Check non-method functions
S2 { f: foo }.foo(&S)
}