| // Copyright 2022 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include <lib/zircon-internal/unique-backtrace.h> |
| #include <zircon/compiler.h> |
| |
| // In the HWASan build, this file provides weak definitions for all the |
| // same entry points that are defined by the HWASan runtime library. |
| // The definitions here are stubs that are used only during the |
| // dynamic linker's startup phase before the HWASan runtime shared |
| // library has been loaded. These are required to satisfy the |
| // references in libc's own code. |
| // |
| // LLVM provides no documentation on the ABI between the compiler and |
| // the runtime. The set of function signatures here was culled from |
| // the LLVM sources for the compiler instrumentation and the runtime |
| // (see llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp and |
| // compiler-rt/lib/hwasan/*). |
| |
| #if __has_feature(hwaddress_sanitizer) |
| |
| // These should never actually be called until the hwasan runtime is loaded. |
| #define HWASAN_TRAP_STUB(name) \ |
| extern "C" __EXPORT __WEAK __NO_SAFESTACK void __hwasan_##name(void) { \ |
| CRASH_WITH_UNIQUE_BACKTRACE(); \ |
| } |
| |
| // These can be called before the runtime is loaded, but they should effectively |
| // do nothing until then. |
| #define HWASAN_STUB(name) \ |
| extern "C" __EXPORT __WEAK __NO_SAFESTACK void __hwasan_##name(void) {} |
| |
| HWASAN_TRAP_STUB(init) |
| HWASAN_STUB(storeN) |
| HWASAN_STUB(store1) |
| HWASAN_STUB(store2) |
| HWASAN_STUB(store4) |
| HWASAN_STUB(store8) |
| HWASAN_STUB(store16) |
| HWASAN_STUB(loadN) |
| HWASAN_STUB(load1) |
| HWASAN_STUB(load2) |
| HWASAN_STUB(load4) |
| HWASAN_STUB(load8) |
| HWASAN_STUB(load16) |
| |
| // TODO(https://fxbug.dev/42060386): The llvm flag for replacing memory checking with |
| // libcalls also replaces memory tagging. Memory tagging can continue to be |
| // inlined though since it's perfectly fine to write tags to shadow memory after |
| // it's set up. |
| HWASAN_STUB(tag_memory) |
| |
| // This is instrumented by hwasan into the prologue of every function. Its |
| // purpose is to add stack information to a thread-local ring buffer in the |
| // hwasan runtime. This information is used during error reporting to check if |
| // an access is being made to the stack within a particular function frame. |
| // This particular stub needs to be empty since it will be called many times |
| // before the runtime has been loaded. Additionally, if hwasan were to find an |
| // actual bug, we should end up crashing in one of the trap stubs above. |
| HWASAN_STUB(add_frame_record) |
| |
| #endif // __has_feature(hwaddress_sanitizer) |
