[scudo] Fix running tests under hwasan.
When built with hwasan, assume that the target architecture does not
support TBI. HWASan uses that byte for its own purpose, and changing it
breaks things.
Reviewed By: hctim
Differential Revision: https://reviews.llvm.org/D111842
GitOrigin-RevId: 439e00a25bde9df851c6f25e356f11f83e884c2f
diff --git a/memtag.h b/memtag.h
index 8097b77..df346bc 100644
--- a/memtag.h
+++ b/memtag.h
@@ -23,7 +23,9 @@
// We assume that Top-Byte Ignore is enabled if the architecture supports memory
// tagging. Not all operating systems enable TBI, so we only claim architectural
// support for memory tagging if the operating system enables TBI.
-#if SCUDO_LINUX && !defined(SCUDO_DISABLE_TBI)
+// HWASan uses the top byte for its own purpose and Scudo should not touch it.
+#if SCUDO_LINUX && !defined(SCUDO_DISABLE_TBI) && \
+ !__has_feature(hwaddress_sanitizer)
inline constexpr bool archSupportsMemoryTagging() { return true; }
#else
inline constexpr bool archSupportsMemoryTagging() { return false; }
