Index: compiler-rt/lib/asan/asan_mapping.h
===================================================================
--- compiler-rt/lib/asan/asan_mapping.h
+++ compiler-rt/lib/asan/asan_mapping.h
@@ -139,7 +139,8 @@
 static const u64 kDefaultShadowSentinel = ~(uptr)0;
 static const u64 kDefaultShadowOffset32 = 1ULL << 29;  // 0x20000000
 static const u64 kDefaultShadowOffset64 = 1ULL << 44;
-static const u64 kDefaultShort64bitShadowOffset = 0x7FFF8000;  // < 2G.
+static const u64 kDefaultShort64bitShadowOffset =
+    0x7FFFFFFF & ~((1 << (12 + kDefaultShadowScale)) - 1);  // < 2G.
 static const u64 kIosShadowOffset32 = 1ULL << 30;  // 0x40000000
 static const u64 kIosShadowOffset64 = 0x120200000;
 static const u64 kIosSimShadowOffset32 = 1ULL << 30;
Index: llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -101,7 +101,8 @@
 static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
 static const uint64_t kIOSSimShadowOffset32 = 1ULL << 30;
 static const uint64_t kIOSSimShadowOffset64 = kDefaultShadowOffset64;
-static const uint64_t kSmallX86_64ShadowOffset = 0x7FFF8000;  // < 2G.
+static const uint64_t kSmallX86_64ShadowOffset =
+    0x7FFFFFFF & ~((1 << (12 + kDefaultShadowScale)) - 1);  // < 2G.
 static const uint64_t kLinuxKasan_ShadowOffset64 = 0xdffffc0000000000;
 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
 static const uint64_t kSystemZ_ShadowOffset64 = 1ULL << 52;