[compiler-rt] [Darwin] Strip MTE tags from ASAN and TSAN (llvm#166453)

ASAN and TSAN need to strip tags in order to compute the correct shadow
addresses.

rdar://163518624

Author: ndrewh

compiler-rt/lib/asan/asan_mapping.h

@@ -285,7 +285,7 @@ extern uptr kHighMemEnd, kMidMemBeg, kMidMemEnd;  // Initialized in __asan_init.
 #    include "asan_mapping_sparc64.h"
 #  else
 #    define MEM_TO_SHADOW(mem) \
-      (((mem) >> ASAN_SHADOW_SCALE) + (ASAN_SHADOW_OFFSET))
+      ((STRIP_MTE_TAG(mem) >> ASAN_SHADOW_SCALE) + (ASAN_SHADOW_OFFSET))
 #    define SHADOW_TO_MEM(mem) \
       (((mem) - (ASAN_SHADOW_OFFSET)) << (ASAN_SHADOW_SCALE))
 
@@ -377,6 +377,7 @@ static inline uptr MemToShadowSize(uptr size) {
 
 static inline bool AddrIsInMem(uptr a) {
   PROFILE_ASAN_MAPPING();
+  a = STRIP_MTE_TAG(a);
   return AddrIsInLowMem(a) || AddrIsInMidMem(a) || AddrIsInHighMem(a) ||
          (flags()->protect_shadow_gap == 0 && AddrIsInShadowGap(a));
 }
@@ -389,6 +390,7 @@ static inline uptr MemToShadow(uptr p) {
 
 static inline bool AddrIsInShadow(uptr a) {
   PROFILE_ASAN_MAPPING();
+  a = STRIP_MTE_TAG(a);
   return AddrIsInLowShadow(a) || AddrIsInMidShadow(a) || AddrIsInHighShadow(a);
 }
 

compiler-rt/lib/sanitizer_common/sanitizer_platform.h

@@ -497,4 +497,11 @@
 #  endif
 #endif
 
+#if SANITIZER_APPLE && SANITIZER_WORDSIZE == 64
+// MTE uses the lower half of the top byte.
+#  define STRIP_MTE_TAG(addr) ((addr) & ~((uptr)0x0f << 56))
+#else
+#  define STRIP_MTE_TAG(addr) (addr)
+#endif
+
 #endif  // SANITIZER_PLATFORM_H

compiler-rt/lib/tsan/rtl/tsan_platform.h

@@ -958,7 +958,9 @@ struct IsAppMemImpl {
 };
 
 ALWAYS_INLINE
-bool IsAppMem(uptr mem) { return SelectMapping<IsAppMemImpl>(mem); }
+bool IsAppMem(uptr mem) {
+  return SelectMapping<IsAppMemImpl>(STRIP_MTE_TAG(mem));
+}
 
 struct IsShadowMemImpl {
   template <typename Mapping>
@@ -997,7 +999,8 @@ struct MemToShadowImpl {
 
 ALWAYS_INLINE
 RawShadow *MemToShadow(uptr x) {
-  return reinterpret_cast<RawShadow *>(SelectMapping<MemToShadowImpl>(x));
+  return reinterpret_cast<RawShadow*>(
+      SelectMapping<MemToShadowImpl>(STRIP_MTE_TAG(x)));
 }
 
 struct MemToMetaImpl {
@@ -1011,7 +1014,9 @@ struct MemToMetaImpl {
 };
 
 ALWAYS_INLINE
-u32 *MemToMeta(uptr x) { return SelectMapping<MemToMetaImpl>(x); }
+u32* MemToMeta(uptr x) {
+  return SelectMapping<MemToMetaImpl>(STRIP_MTE_TAG(x));
+}
 
 struct ShadowToMemImpl {
   template <typename Mapping>