Index: compiler-rt/lib/msan/msan.h
===================================================================
--- compiler-rt/lib/msan/msan.h
+++ compiler-rt/lib/msan/msan.h
@@ -72,88 +72,48 @@
 // - 0x0007f80000000-0x0007fffffffff: 39-bits libraries segments
 // - 0x002aa00000000-0x002ab00000000: 42-bits PIE program segments
 // - 0x003ff00000000-0x003ffffffffff: 42-bits libraries segments
-// - 0x0aaaaa0000000-0x0aaab00000000: 48-bits PIE program segments
-// - 0xffff000000000-0x1000000000000: 48-bits libraries segments
-// It is fragmented in multiples segments to increase the memory available
-// on 42-bits (12.21% of total VMA available for 42-bits and 13.28 for
-// 39 bits). The 48-bits segments only cover the usual PIE/default segments
-// plus some more segments (262144GB total, 0.39% total VMA).
+// - 0x0aaa000000000-0x0aab000000000: 48-bits PIE program segments
+// - 0xff00000000000-0x1000000000000: 48-bits libraries segments
+// The 48-bits segments only cover the usual PIE/default segments
+// plus some more segments (262144GB total, 0.51% total VMA).
 const MappingDesc kMemoryLayout[] = {
-    {0x00000000000ULL, 0x01000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x01000000000ULL, 0x02000000000ULL, MappingDesc::SHADOW, "shadow-2"},
-    {0x02000000000ULL, 0x03000000000ULL, MappingDesc::ORIGIN, "origin-2"},
-    {0x03000000000ULL, 0x04000000000ULL, MappingDesc::SHADOW, "shadow-1"},
-    {0x04000000000ULL, 0x05000000000ULL, MappingDesc::ORIGIN, "origin-1"},
-    {0x05000000000ULL, 0x06000000000ULL, MappingDesc::APP, "app-1"},
-    {0x06000000000ULL, 0x07000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x07000000000ULL, 0x08000000000ULL, MappingDesc::APP, "app-2"},
-    {0x08000000000ULL, 0x09000000000ULL, MappingDesc::INVALID, "invalid"},
-    // The mappings below are used only for 42-bits VMA.
-    {0x09000000000ULL, 0x0A000000000ULL, MappingDesc::SHADOW, "shadow-3"},
-    {0x0A000000000ULL, 0x0B000000000ULL, MappingDesc::ORIGIN, "origin-3"},
-    {0x0B000000000ULL, 0x0F000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0F000000000ULL, 0x10000000000ULL, MappingDesc::APP, "app-3"},
-    {0x10000000000ULL, 0x11000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x11000000000ULL, 0x12000000000ULL, MappingDesc::APP, "app-4"},
-    {0x12000000000ULL, 0x17000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x17000000000ULL, 0x18000000000ULL, MappingDesc::SHADOW, "shadow-4"},
-    {0x18000000000ULL, 0x19000000000ULL, MappingDesc::ORIGIN, "origin-4"},
-    {0x19000000000ULL, 0x20000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x20000000000ULL, 0x21000000000ULL, MappingDesc::APP, "app-5"},
-    {0x21000000000ULL, 0x26000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x26000000000ULL, 0x27000000000ULL, MappingDesc::SHADOW, "shadow-5"},
-    {0x27000000000ULL, 0x28000000000ULL, MappingDesc::ORIGIN, "origin-5"},
-    {0x28000000000ULL, 0x29000000000ULL, MappingDesc::SHADOW, "shadow-7"},
-    {0x29000000000ULL, 0x2A000000000ULL, MappingDesc::ORIGIN, "origin-7"},
-    {0x2A000000000ULL, 0x2B000000000ULL, MappingDesc::APP, "app-6"},
-    {0x2B000000000ULL, 0x2C000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x2C000000000ULL, 0x2D000000000ULL, MappingDesc::SHADOW, "shadow-6"},
-    {0x2D000000000ULL, 0x2E000000000ULL, MappingDesc::ORIGIN, "origin-6"},
-    {0x2E000000000ULL, 0x2F000000000ULL, MappingDesc::APP, "app-7"},
-    {0x2F000000000ULL, 0x39000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x39000000000ULL, 0x3A000000000ULL, MappingDesc::SHADOW, "shadow-9"},
-    {0x3A000000000ULL, 0x3B000000000ULL, MappingDesc::ORIGIN, "origin-9"},
-    {0x3B000000000ULL, 0x3C000000000ULL, MappingDesc::APP, "app-8"},
-    {0x3C000000000ULL, 0x3D000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x3D000000000ULL, 0x3E000000000ULL, MappingDesc::SHADOW, "shadow-8"},
-    {0x3E000000000ULL, 0x3F000000000ULL, MappingDesc::ORIGIN, "origin-8"},
-    {0x3F000000000ULL, 0x40000000000ULL, MappingDesc::APP, "app-9"},
-    // The mappings below are used only for 48-bits VMA.
-    // TODO(unknown): 48-bit mapping ony covers the usual PIE, non-PIE
-    // segments and some more segments totalizing 262144GB of VMA (which cover
-    // only 0.32% of all 48-bit VMA). Memory availability can be increase by
-    // adding multiple application segments like 39 and 42 mapping.
-    {0x0040000000000ULL, 0x0041000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0041000000000ULL, 0x0042000000000ULL, MappingDesc::APP, "app-10"},
-    {0x0042000000000ULL, 0x0047000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0047000000000ULL, 0x0048000000000ULL, MappingDesc::SHADOW, "shadow-10"},
-    {0x0048000000000ULL, 0x0049000000000ULL, MappingDesc::ORIGIN, "origin-10"},
-    {0x0049000000000ULL, 0x0050000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0050000000000ULL, 0x0051000000000ULL, MappingDesc::APP, "app-11"},
-    {0x0051000000000ULL, 0x0056000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0056000000000ULL, 0x0057000000000ULL, MappingDesc::SHADOW, "shadow-11"},
-    {0x0057000000000ULL, 0x0058000000000ULL, MappingDesc::ORIGIN, "origin-11"},
-    {0x0058000000000ULL, 0x0059000000000ULL, MappingDesc::APP, "app-12"},
-    {0x0059000000000ULL, 0x005E000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x005E000000000ULL, 0x005F000000000ULL, MappingDesc::SHADOW, "shadow-12"},
-    {0x005F000000000ULL, 0x0060000000000ULL, MappingDesc::ORIGIN, "origin-12"},
-    {0x0060000000000ULL, 0x0061000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0061000000000ULL, 0x0062000000000ULL, MappingDesc::APP, "app-13"},
-    {0x0062000000000ULL, 0x0067000000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0067000000000ULL, 0x0068000000000ULL, MappingDesc::SHADOW, "shadow-13"},
-    {0x0068000000000ULL, 0x0069000000000ULL, MappingDesc::ORIGIN, "origin-13"},
-    {0x0069000000000ULL, 0x0AAAAA0000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0AAAAA0000000ULL, 0x0AAAB00000000ULL, MappingDesc::APP, "app-14"},
-    {0x0AAAB00000000ULL, 0x0AACAA0000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0AACAA0000000ULL, 0x0AACB00000000ULL, MappingDesc::SHADOW, "shadow-14"},
-    {0x0AACB00000000ULL, 0x0AADAA0000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0AADAA0000000ULL, 0x0AADB00000000ULL, MappingDesc::ORIGIN, "origin-14"},
-    {0x0AADB00000000ULL, 0x0FF9F00000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0FF9F00000000ULL, 0x0FFA000000000ULL, MappingDesc::SHADOW, "shadow-15"},
-    {0x0FFA000000000ULL, 0x0FFAF00000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0FFAF00000000ULL, 0x0FFB000000000ULL, MappingDesc::ORIGIN, "origin-15"},
-    {0x0FFB000000000ULL, 0x0FFFF00000000ULL, MappingDesc::INVALID, "invalid"},
-    {0x0FFFF00000000ULL, 0x1000000000000ULL, MappingDesc::APP, "app-15"},
+    {0X0000000000000, 0X0001000000000, MappingDesc::INVALID, "invalid"},
+    {0X0001000000000, 0X0002000000000, MappingDesc::SHADOW, "shadow-13"},
+    {0X0002000000000, 0X0011000000000, MappingDesc::INVALID, "invalid"},
+    {0X0011000000000, 0X0012000000000, MappingDesc::ORIGIN, "origin-13"},
+    {0X0012000000000, 0X0021000000000, MappingDesc::INVALID, "invalid"},
+    {0X0021000000000, 0X0022000000000, MappingDesc::SHADOW, "shadow-10"},
+    {0X0022000000000, 0X0030000000000, MappingDesc::INVALID, "invalid"},
+    {0X0030000000000, 0X0031000000000, MappingDesc::SHADOW, "shadow-11"},
+    {0X0031000000000, 0X0032000000000, MappingDesc::ORIGIN, "origin-10"},
+    {0X0032000000000, 0X0038000000000, MappingDesc::INVALID, "invalid"},
+    {0X0038000000000, 0X0039000000000, MappingDesc::SHADOW, "shadow-12"},
+    {0X0039000000000, 0X0040000000000, MappingDesc::INVALID, "invalid"},
+    {0X0040000000000, 0X0041000000000, MappingDesc::ORIGIN, "origin-11"},
+    {0X0041000000000, 0X0042000000000, MappingDesc::APP, "app-10"},
+    {0X0042000000000, 0X0048000000000, MappingDesc::INVALID, "invalid"},
+    {0X0048000000000, 0X0049000000000, MappingDesc::ORIGIN, "origin-12"},
+    {0X0049000000000, 0X0050000000000, MappingDesc::INVALID, "invalid"},
+    {0X0050000000000, 0X0051000000000, MappingDesc::APP, "app-11"},
+    {0X0051000000000, 0X0058000000000, MappingDesc::INVALID, "invalid"},
+    {0X0058000000000, 0X0059000000000, MappingDesc::APP, "app-12"},
+    {0X0059000000000, 0X0060000000000, MappingDesc::INVALID, "invalid"},
+    {0X0060000000000, 0X0060100000000, MappingDesc::SHADOW, "shadow-1"},
+    {0X0060100000000, 0X0061000000000, MappingDesc::INVALID, "invalid"},
+    {0X0061000000000, 0X0062000000000, MappingDesc::APP, "app-13"},
+    {0X0062000000000, 0X0070000000000, MappingDesc::INVALID, "invalid"},
+    {0X0070000000000, 0X0070100000000, MappingDesc::ORIGIN, "origin-1"},
+    {0X0070100000000, 0X0AAA000000000, MappingDesc::INVALID, "invalid"},
+    {0X0AAA000000000, 0X0AAB000000000, MappingDesc::APP, "app-14"},
+    {0X0AAB000000000, 0X0ACA000000000, MappingDesc::INVALID, "invalid"},
+    {0X0ACA000000000, 0X0ACB000000000, MappingDesc::SHADOW, "shadow-14"},
+    {0X0ACB000000000, 0X0ADA000000000, MappingDesc::INVALID, "invalid"},
+    {0X0ADA000000000, 0X0ADB000000000, MappingDesc::ORIGIN, "origin-14"},
+    {0X0ADB000000000, 0X0F90000000000, MappingDesc::INVALID, "invalid"},
+    {0X0F90000000000, 0X0FA0000000000, MappingDesc::SHADOW, "shadow-15"},
+    {0X0FA0000000000, 0X0FB0000000000, MappingDesc::ORIGIN, "origin-15"},
+    {0X0FB0000000000, 0X0FF0000000000, MappingDesc::INVALID, "invalid"},
+    {0X0FF0000000000, 0X1000000000000, MappingDesc::APP, "app-15"},
 };
 # define MEM_TO_SHADOW(mem) ((uptr)mem ^ 0x6000000000ULL)
 # define SHADOW_TO_ORIGIN(shadow) (((uptr)(shadow)) + 0x1000000000ULL)
Index: llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -436,9 +436,9 @@
 // aarch64 Linux
 static const MemoryMapParams Linux_AArch64_MemoryMapParams = {
     0,             // AndMask (not used)
-    0x06000000000, // XorMask
+    0x60000000000, // XorMask
     0,             // ShadowBase (not used)
-    0x01000000000, // OriginBase
+    0x10000000000, // OriginBase
 };
 
 // aarch64 FreeBSD