Index: lib/asan/asan_allocator.h
===================================================================
--- lib/asan/asan_allocator.h
+++ lib/asan/asan_allocator.h
@@ -133,11 +133,15 @@
 const uptr kAllocatorSize  =  0x2000000000ULL;  // 128G.
 typedef VeryCompactSizeClassMap SizeClassMap;
 # elif defined(__aarch64__)
-// AArch64/SANITIZER_CAN_USER_ALLOCATOR64 is only for 42-bit VMA
+// AArch64/SANITIZER_CAN_USE_ALLOCATOR64 is only for 42-bit VMA
 // so no need to different values for different VMA.
 const uptr kAllocatorSpace =  0x10000000000ULL;
 const uptr kAllocatorSize  =  0x10000000000ULL;  // 3T.
 typedef DefaultSizeClassMap SizeClassMap;
+#elif defined(__sparc__)
+const uptr kAllocatorSpace = ~(uptr)0;
+const uptr kAllocatorSize = 0x20000000000ULL;  // 2T.
+typedef DefaultSizeClassMap SizeClassMap;
 # elif SANITIZER_WINDOWS
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize  =  0x8000000000ULL;  // 500G
Index: lib/asan/asan_mapping.h
===================================================================
--- lib/asan/asan_mapping.h
+++ lib/asan/asan_mapping.h
@@ -100,6 +100,13 @@
 // || `[0x10000000000000, 0x11ffffffffffff]` || LowShadow  ||
 // || `[0x00000000000000, 0x0fffffffffffff]` || LowMem     ||
 //
+// Default Linux/SPARC64 (52-bit VMA) mapping:
+// || `[0x8000000000000, 0xfffffffffffff]` || HighMem    ||
+// || `[0x1080000000000, 0x207ffffffffff]` || HighShadow ||
+// || `[0x0090000000000, 0x107ffffffffff]` || ShadowGap  ||
+// || `[0x0080000000000, 0x008ffffffffff]` || LowShadow  ||
+// || `[0x0000000000000, 0x007ffffffffff]` || LowMem     ||
+//
 // Shadow mapping on FreeBSD/x86-64 with SHADOW_OFFSET == 0x400000000000:
 // || `[0x500000000000, 0x7fffffffffff]` || HighMem    ||
 // || `[0x4a0000000000, 0x4fffffffffff]` || HighShadow ||
@@ -162,6 +169,7 @@
 static const u64 kMIPS64_ShadowOffset64 = 1ULL << 37;
 static const u64 kPPC64_ShadowOffset64 = 1ULL << 44;
 static const u64 kSystemZ_ShadowOffset64 = 1ULL << 52;
+static const u64 kSPARC64_ShadowOffset64 = 1ULL << 43;  // 0x80000000000
 static const u64 kFreeBSD_ShadowOffset32 = 1ULL << 30;  // 0x40000000
 static const u64 kFreeBSD_ShadowOffset64 = 1ULL << 46;  // 0x400000000000
 static const u64 kNetBSD_ShadowOffset32 = 1ULL << 30;  // 0x40000000
@@ -224,6 +232,8 @@
 #   define SHADOW_OFFSET kDefaultShadowOffset64
 #  elif defined(__mips64)
 #   define SHADOW_OFFSET kMIPS64_ShadowOffset64
+#elif defined(__sparc__)
+#define SHADOW_OFFSET kSPARC64_ShadowOffset64
 #  elif SANITIZER_WINDOWS64
 #   define SHADOW_OFFSET __asan_shadow_memory_dynamic_address
 #  else
@@ -270,6 +280,8 @@
 
 #if SANITIZER_MYRIAD2
 #include "asan_mapping_myriad.h"
+#elif defined(__sparc__) && SANITIZER_WORDSIZE == 64
+#include "asan_mapping_sparc64.h"
 #else
 #define MEM_TO_SHADOW(mem) (((mem) >> SHADOW_SCALE) + (SHADOW_OFFSET))
 
Index: lib/asan/asan_mapping_sparc64.h
===================================================================
--- lib/asan/asan_mapping_sparc64.h
+++ lib/asan/asan_mapping_sparc64.h
@@ -0,0 +1,101 @@
+//===-- asan_mapping_sparc64.h ----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// SPARC64-specific definitions for ASan memory mapping.
+//===----------------------------------------------------------------------===//
+#ifndef ASAN_MAPPING_SPARC64_H
+#define ASAN_MAPPING_SPARC64_H
+
+// This is tailored to the 52-bit VM layout on SPARC-T4 and later.
+// The VM space is split into two 51-bit halves at both ends: the low part
+// has all the bits above the 51st cleared, while the high part has them set.
+//   0xfff8000000000000 - 0xffffffffffffffff
+//   0x0000000000000000 - 0x0007ffffffffffff
+
+#define VMA_BITS 52
+#define HIGH_BITS (64 - VMA_BITS)
+
+// The idea is to chop the high bits before doing the scaling, so the two
+// parts become contiguous again and the usual scheme can be applied.
+
+#define MEM_TO_SHADOW(mem) \
+  ((((mem) << HIGH_BITS) >> (HIGH_BITS + (SHADOW_SCALE))) + (SHADOW_OFFSET))
+
+#define kLowMemBeg 0
+#define kLowMemEnd (SHADOW_OFFSET - 1)
+
+#define kLowShadowBeg SHADOW_OFFSET
+#define kLowShadowEnd MEM_TO_SHADOW(kLowMemEnd)
+
+// But of course there is the huge hole between the high shadow memory,
+// which is in the low part, and the beginning of the high part.
+
+#define kHighMemBeg (-(1ULL << (VMA_BITS - 1)))
+
+#define kHighShadowBeg MEM_TO_SHADOW(kHighMemBeg)
+#define kHighShadowEnd MEM_TO_SHADOW(kHighMemEnd)
+
+#define kMidShadowBeg 0
+#define kMidShadowEnd 0
+
+// With the zero shadow base we can not actually map pages starting from 0.
+// This constant is somewhat arbitrary.
+#define kZeroBaseShadowStart 0
+#define kZeroBaseMaxShadowStart (1 << 18)
+
+#define kShadowGapBeg (kLowShadowEnd + 1)
+#define kShadowGapEnd (kHighShadowBeg - 1)
+
+#define kShadowGap2Beg 0
+#define kShadowGap2End 0
+
+#define kShadowGap3Beg 0
+#define kShadowGap3End 0
+
+namespace __asan {
+
+static inline bool AddrIsInLowMem(uptr a) {
+  PROFILE_ASAN_MAPPING();
+  return a <= kLowMemEnd;
+}
+
+static inline bool AddrIsInLowShadow(uptr a) {
+  PROFILE_ASAN_MAPPING();
+  return a >= kLowShadowBeg && a <= kLowShadowEnd;
+}
+
+static inline bool AddrIsInMidMem(uptr a) {
+  PROFILE_ASAN_MAPPING();
+  return false;
+}
+
+static inline bool AddrIsInMidShadow(uptr a) {
+  PROFILE_ASAN_MAPPING();
+  return false;
+}
+
+static inline bool AddrIsInHighMem(uptr a) {
+  PROFILE_ASAN_MAPPING();
+  return kHighMemBeg && a >= kHighMemBeg && a <= kHighMemEnd;
+}
+
+static inline bool AddrIsInHighShadow(uptr a) {
+  PROFILE_ASAN_MAPPING();
+  return kHighMemBeg && a >= kHighShadowBeg && a <= kHighShadowEnd;
+}
+
+static inline bool AddrIsInShadowGap(uptr a) {
+  PROFILE_ASAN_MAPPING();
+  return a >= kShadowGapBeg && a <= kShadowGapEnd;
+}
+
+}  // namespace __asan
+
+#endif  // ASAN_MAPPING_SPARC64_H