[HWASAN] Fix HwasanReallocate in aliasing mode

HWASAN_ALIASING_MODE needs to untag only
primary allocator pointers.

Reviewed By: kstoimenov

Differential Revision: https://reviews.llvm.org/D149293

Author: vitalybuka

compiler-rt/lib/hwasan/hwasan_allocator.cpp

@@ -384,9 +384,12 @@ static void *HwasanReallocate(StackTrace *stack, void *tagged_ptr_old,
   if (tagged_ptr_old && tagged_ptr_new) {
     Metadata *meta =
         reinterpret_cast<Metadata *>(allocator.GetMetaData(untagged_ptr_old));
-    internal_memcpy(
-        UntagPtr(tagged_ptr_new), untagged_ptr_old,
-        Min(new_size, static_cast<uptr>(meta->GetRequestedSize())));
+    void *untagged_ptr_new =
+        InTaggableRegion(reinterpret_cast<uptr>(tagged_ptr_new))
+            ? UntagPtr(tagged_ptr_new)
+            : tagged_ptr_new;
+    internal_memcpy(untagged_ptr_new, untagged_ptr_old,
+                    Min(new_size, static_cast<uptr>(meta->GetRequestedSize())));
     HwasanDeallocate(stack, tagged_ptr_old);
   }
   return tagged_ptr_new;

compiler-rt/test/sanitizer_common/TestCases/max_allocation_size.cpp

@@ -43,9 +43,6 @@
 // win32 is disabled due to failing errno tests.
 // UNSUPPORTED: ubsan, target={{.*windows-msvc.*}}
 
-// FIXME: Something crashes.
-// XFAIL: hwasan-aliasing
-
 #include <assert.h>
 #include <errno.h>
 #include <limits>