3 Commits

Author	SHA1	Message	Date
Aleksandr Nogikh	b8618ff61e	[AllocToken] [Clang] Fix type inference for atomic types (#183571) ... When evaluating whether an allocated type contains a pointer to generate the `alloc_token` metadata, `typeContainsPointer` incorrectly stopped recursion upon encountering an `AtomicType`. This resulted in types like `_Atomic(int *)` (or `std::atomic<int *>` under libc++) being incorrectly evaluated as not containing a pointer. Add support for `AtomicType` in `typeContainsPointer` by recursively checking the contained type. Add tests for structs containing `_Atomic(int *)` and `_Atomic(int)`.	2026-02-26 10:57:49 -08:00
Marco Elver	dfa8732d05	[AllocToken, Clang] Infer type hints from sizeof expressions and casts (#156841) ... For the AllocToken pass to accurately calculate token ID hints, we need to attach `!alloc_token` metadata for allocation calls. Unlike new expressions, untyped allocation calls (like `malloc`, `calloc`, `::operator new(..)`, `__builtin_operator_new`, etc.) have no syntactic type associated with them. For -fsanitize=alloc-token, type hints are sufficient, and we can attempt to infer the type based on common idioms. When encountering allocation calls (with `__attribute__((malloc))` or `__attribute__((alloc_size(..))`), attach `!alloc_token` by inferring the allocated type from (a) sizeof argument expressions such as `malloc(sizeof(MyType))`, and (b) casts such as `(MyType*)malloc(4096)`. Note that non-standard allocation functions with these attributes are not instrumented by default. Use `-fsanitize-alloc-token-extended` to instrument them as well. Link: https://discourse.llvm.org/t/rfc-a-framework-for-allocator-partitioning-hints/87434 --- This change is part of the following series: 1. https://github.com/llvm/llvm-project/pull/160131 2. https://github.com/llvm/llvm-project/pull/156838 3. https://github.com/llvm/llvm-project/pull/162098 4. https://github.com/llvm/llvm-project/pull/162099 5. https://github.com/llvm/llvm-project/pull/156839 6. https://github.com/llvm/llvm-project/pull/156840 7. https://github.com/llvm/llvm-project/pull/156841 8. https://github.com/llvm/llvm-project/pull/156842	2025-10-09 09:31:16 +02:00
Marco Elver	6359980f5b	[AllocToken, Clang] Implement TypeHashPointerSplit mode (#156840) ... Implement the TypeHashPointerSplit mode: This mode assigns a token ID based on the hash of the allocated type's name, where the top half ID-space is reserved for types that contain pointers and the bottom half for types that do not contain pointers. This mode with max tokens of 2 (`-falloc-token-max=2`) may also be valuable for heap hardening strategies that simply separate pointer types from non-pointer types. Make it the new default mode. Link: https://discourse.llvm.org/t/rfc-a-framework-for-allocator-partitioning-hints/87434 --- This change is part of the following series: 1. https://github.com/llvm/llvm-project/pull/160131 2. https://github.com/llvm/llvm-project/pull/156838 3. https://github.com/llvm/llvm-project/pull/162098 4. https://github.com/llvm/llvm-project/pull/162099 5. https://github.com/llvm/llvm-project/pull/156839 6. https://github.com/llvm/llvm-project/pull/156840 7. https://github.com/llvm/llvm-project/pull/156841 8. https://github.com/llvm/llvm-project/pull/156842	2025-10-08 21:58:37 +02:00