From 14b83de047595a27c4ad8dadb99a42a1b5ab0194 Mon Sep 17 00:00:00 2001 From: Ramon de C Valle Date: Thu, 7 Oct 2021 15:33:13 -0700 Subject: [PATCH] Add LLVM CFI support to the Rust compiler This commit adds LLVM Control Flow Integrity (CFI) support to the Rust compiler. It initially provides forward-edge control flow protection for Rust-compiled code only by aggregating function pointers in groups identified by their number of arguments. Forward-edge control flow protection for C or C++ and Rust -compiled code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code share the same virtual address space) will be provided in later work as part of this project by defining and using compatible type identifiers (see Type metadata in the design document in the tracking issue #89653). LLVM CFI can be enabled with -Zsanitizer=cfi and requires LTO (i.e., -Clto). --- src/builder.rs | 10 ++++++++++ src/intrinsic/mod.rs | 5 +++++ 2 files changed, 15 insertions(+) diff --git a/src/builder.rs b/src/builder.rs index ac908418ee4..fff2aa6df7c 100644 --- a/src/builder.rs +++ b/src/builder.rs @@ -915,6 +915,16 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> { // TODO(antoyo) } + fn type_metadata(&mut self, _function: RValue<'gcc>, _typeid: String) { + // Unsupported. + } + + fn typeid_metadata(&mut self, _typeid: String) -> RValue<'gcc> { + // Unsupported. + self.context.new_rvalue_from_int(self.int_type, 0) + } + + fn store(&mut self, val: RValue<'gcc>, ptr: RValue<'gcc>, align: Align) -> RValue<'gcc> { self.store_with_flags(val, ptr, align, MemFlags::empty()) } diff --git a/src/intrinsic/mod.rs b/src/intrinsic/mod.rs index 375d422cb25..64bd586662d 100644 --- a/src/intrinsic/mod.rs +++ b/src/intrinsic/mod.rs @@ -367,6 +367,11 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'gcc, 'tcx> { // TODO(antoyo) } + fn type_test(&mut self, _pointer: Self::Value, _typeid: Self::Value) -> Self::Value { + // Unsupported. + self.context.new_rvalue_from_int(self.int_type, 0) + } + fn va_start(&mut self, _va_list: RValue<'gcc>) -> RValue<'gcc> { unimplemented!(); }