Revert "[hwasan] Record and display stack history in stack-based reports."

This reverts commit r342921: test failures on clang-cmake-arm* bots.

llvm-svn: 342922

21 files changed, 228 insertions, 908 deletions

diff --git a/compiler-rt/lib/hwasan/CMakeLists.txt b/compiler-rt/lib/hwasan/CMakeLists.txt
index 3c00eddfbfa..cb9167a3e96 100644
--- a/compiler-rt/lib/hwasan/CMakeLists.txt
+++ b/compiler-rt/lib/hwasan/CMakeLists.txt
@@ -10,7 +10,6 @@ set(HWASAN_RTL_SOURCES
   hwasan_poisoning.cc
   hwasan_report.cc
   hwasan_thread.cc
-  hwasan_thread_list.cc
   )
 
 set(HWASAN_RTL_CXX_SOURCES
@@ -26,9 +25,8 @@ set(HWASAN_RTL_HEADERS
   hwasan_mapping.h
   hwasan_poisoning.h
   hwasan_report.h
-  hwasan_thread.h
-  hwasan_thread_list.h
-  )
+  hwasan_thread.h)
+
 
 set(HWASAN_DEFINITIONS)
 append_list_if(COMPILER_RT_HWASAN_WITH_INTERCEPTORS HWASAN_WITH_INTERCEPTORS=1 HWASAN_DEFINITIONS)
diff --git a/compiler-rt/lib/hwasan/hwasan.cc b/compiler-rt/lib/hwasan/hwasan.cc
index 02aee4d61c6..79fcc6a39f0 100644
--- a/compiler-rt/lib/hwasan/hwasan.cc
+++ b/compiler-rt/lib/hwasan/hwasan.cc
@@ -17,7 +17,6 @@
 #include "hwasan_poisoning.h"
 #include "hwasan_report.h"
 #include "hwasan_thread.h"
-#include "hwasan_thread_list.h"
 #include "sanitizer_common/sanitizer_atomic.h"
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_flags.h"
@@ -175,8 +174,7 @@ static void HWAsanCheckFailed(const char *file, int line, const char *cond,
 static constexpr uptr kMemoryUsageBufferSize = 4096;
 
 static void HwasanFormatMemoryUsage(InternalScopedString &s) {
-  HwasanThreadList &thread_list = hwasanThreadList();
-  auto thread_stats = thread_list.GetThreadStats();
+  auto thread_stats = Thread::GetThreadStats();
   auto *sds = StackDepotGetStats();
   AllocatorStatCounters asc;
   GetAllocatorStats(asc);
@@ -186,7 +184,7 @@ static void HwasanFormatMemoryUsage(InternalScopedString &s) {
       " heap: %zd",
       internal_getpid(), GetRSS(), thread_stats.n_live_threads,
       thread_stats.total_stack_size,
-      thread_stats.n_live_threads * thread_list.MemoryUsedPerThread(),
+      thread_stats.n_live_threads * Thread::MemoryUsedPerThread(),
       sds->allocated, sds->n_uniq_ids, asc[AllocatorStatMapped]);
 }
 
@@ -255,12 +253,7 @@ void __hwasan_init() {
   __sanitizer_set_report_path(common_flags()->log_path);
 
   DisableCoreDumperIfNecessary();
-
   __hwasan_shadow_init();
-
-  InitThreads();
-  hwasanThreadList().CreateCurrentThread();
-
   MadviseShadow();
 
   // This may call libc -> needs initialized shadow.
@@ -275,10 +268,11 @@ void __hwasan_init() {
   InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
 
   HwasanTSDInit();
-  HwasanTSDThreadInit();
 
   HwasanAllocatorInit();
 
+  Thread::Create();
+
 #if HWASAN_CONTAINS_UBSAN
   __ubsan::InitAsPlugin();
 #endif
diff --git a/compiler-rt/lib/hwasan/hwasan.h b/compiler-rt/lib/hwasan/hwasan.h
index a3da09e883d..bfd76759cd0 100644
--- a/compiler-rt/lib/hwasan/hwasan.h
+++ b/compiler-rt/lib/hwasan/hwasan.h
@@ -41,10 +41,6 @@ typedef u8 tag_t;
 const unsigned kAddressTagShift = 56;
 const uptr kAddressTagMask = 0xFFUL << kAddressTagShift;
 
-// Minimal alignment of the shadow base address. Determines the space available
-// for threads and stack histories. This is an ABI constant.
-const unsigned kShadowBaseAlignment = 32;
-
 static inline tag_t GetTagFromPointer(uptr p) {
   return p >> kAddressTagShift;
 }
@@ -70,7 +66,6 @@ extern int hwasan_report_count;
 
 bool ProtectRange(uptr beg, uptr end);
 bool InitShadow();
-void InitThreads();
 void MadviseShadow();
 char *GetProcSelfMaps();
 void InitializeInterceptors();
@@ -147,7 +142,6 @@ class ScopedThreadLocalStateBackup {
 };
 
 void HwasanTSDInit();
-void HwasanTSDThreadInit();
 
 void HwasanOnDeadlySignal(int signo, void *info, void *context);
 
diff --git a/compiler-rt/lib/hwasan/hwasan_dynamic_shadow.cc b/compiler-rt/lib/hwasan/hwasan_dynamic_shadow.cc
index 87670f50828..09b2ccfea1e 100644
--- a/compiler-rt/lib/hwasan/hwasan_dynamic_shadow.cc
+++ b/compiler-rt/lib/hwasan/hwasan_dynamic_shadow.cc
@@ -13,7 +13,6 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#include "hwasan.h"
 #include "hwasan_dynamic_shadow.h"
 #include "hwasan_mapping.h"
 #include "sanitizer_common/sanitizer_common.h"
@@ -36,16 +35,12 @@ static void UnmapFromTo(uptr from, uptr to) {
   }
 }
 
-// Returns an address aligned to kShadowBaseAlignment, such that
-// 2**kShadowBaseAlingment on the left and shadow_size_bytes bytes on the right
-// of it are mapped no access.
+// Returns an address aligned to 8 pages, such that one page on the left and
+// shadow_size_bytes bytes on the right of it are mapped r/o.
 static uptr MapDynamicShadow(uptr shadow_size_bytes) {
   const uptr granularity = GetMmapGranularity();
-  const uptr min_alignment = granularity << kShadowScale;
-  const uptr alignment = 1ULL << kShadowBaseAlignment;
-  CHECK_GE(alignment, min_alignment);
-
-  const uptr left_padding = 1ULL << kShadowBaseAlignment;
+  const uptr alignment = granularity << kShadowScale;
+  const uptr left_padding = granularity;
   const uptr shadow_size =
       RoundUpTo(shadow_size_bytes, granularity);
   const uptr map_size = shadow_size + left_padding + alignment;
diff --git a/compiler-rt/lib/hwasan/hwasan_flags.inc b/compiler-rt/lib/hwasan/hwasan_flags.inc
index f1b416d150a..f806b83b5b1 100644
--- a/compiler-rt/lib/hwasan/hwasan_flags.inc
+++ b/compiler-rt/lib/hwasan/hwasan_flags.inc
@@ -51,7 +51,3 @@ HWASAN_FLAG(int, heap_history_size, 1023,
           "to find bugs.")
 HWASAN_FLAG(bool, export_memory_stats, true,
             "Export up-to-date memory stats through /proc")
-HWASAN_FLAG(int, stack_history_size, 1024,
-            "The number of stack frames remembered per thread. "
-            "Affects the quality of stack-related reports, but not the ability "
-            "to find bugs.")
diff --git a/compiler-rt/lib/hwasan/hwasan_linux.cc b/compiler-rt/lib/hwasan/hwasan_linux.cc
index f8e83ff0370..3285431eb12 100644
--- a/compiler-rt/lib/hwasan/hwasan_linux.cc
+++ b/compiler-rt/lib/hwasan/hwasan_linux.cc
@@ -22,7 +22,6 @@
 #include "hwasan_mapping.h"
 #include "hwasan_report.h"
 #include "hwasan_thread.h"
-#include "hwasan_thread_list.h"
 
 #include <elf.h>
 #include <link.h>
@@ -38,10 +37,6 @@
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_procmaps.h"
 
-#if HWASAN_WITH_INTERCEPTORS && !SANITIZER_ANDROID
-THREADLOCAL uptr __hwasan_tls;
-#endif
-
 namespace __hwasan {
 
 static void ReserveShadowMemoryRange(uptr beg, uptr end, const char *name) {
@@ -184,20 +179,6 @@ bool InitShadow() {
   return true;
 }
 
-void InitThreads() {
-  CHECK(__hwasan_shadow_memory_dynamic_address);
-  uptr guard_page_size = GetMmapGranularity();
-  uptr thread_space_start =
-      __hwasan_shadow_memory_dynamic_address - (1ULL << kShadowBaseAlignment);
-  uptr thread_space_end =
-      __hwasan_shadow_memory_dynamic_address - guard_page_size;
-  ReserveShadowMemoryRange(thread_space_start, thread_space_end - 1,
-                           "hwasan threads");
-  ProtectGap(thread_space_end,
-             __hwasan_shadow_memory_dynamic_address - thread_space_end);
-  InitThreadList(thread_space_start, thread_space_end - thread_space_start);
-}
-
 static void MadviseShadowRegion(uptr beg, uptr end) {
   uptr size = end - beg + 1;
   if (common_flags()->no_huge_pages_for_shadow)
@@ -233,7 +214,7 @@ void InstallAtExitHandler() {
 // ---------------------- TSD ---------------- {{{1
 
 extern "C" void __hwasan_thread_enter() {
-  hwasanThreadList().CreateCurrentThread();
+  Thread::Create();
 }
 
 extern "C" void __hwasan_thread_exit() {
@@ -241,25 +222,21 @@ extern "C" void __hwasan_thread_exit() {
   // Make sure that signal handler can not see a stale current thread pointer.
   atomic_signal_fence(memory_order_seq_cst);
   if (t)
-    hwasanThreadList().ReleaseThread(t);
+    t->Destroy();
 }
 
 #if HWASAN_WITH_INTERCEPTORS
 static pthread_key_t tsd_key;
 static bool tsd_key_inited = false;
 
-void HwasanTSDThreadInit() {
-  if (tsd_key_inited)
-    CHECK_EQ(0, pthread_setspecific(tsd_key,
-                                    (void *)GetPthreadDestructorIterations()));
-}
-
 void HwasanTSDDtor(void *tsd) {
-  uptr iterations = (uptr)tsd;
-  if (iterations > 1) {
-    CHECK_EQ(0, pthread_setspecific(tsd_key, (void *)(iterations - 1)));
+  Thread *t = (Thread*)tsd;
+  if (t->destructor_iterations_ > 1) {
+    t->destructor_iterations_--;
+    CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
     return;
   }
+  t->Destroy();
   __hwasan_thread_exit();
 }
 
@@ -268,26 +245,31 @@ void HwasanTSDInit() {
   tsd_key_inited = true;
   CHECK_EQ(0, pthread_key_create(&tsd_key, HwasanTSDDtor));
 }
-#else
-void HwasanTSDInit() {}
-void HwasanTSDThreadInit() {}
-#endif
 
-#if SANITIZER_ANDROID
-uptr *GetCurrentThreadLongPtr() {
-  return (uptr *)get_android_tls_ptr();
-}
-#else
-uptr *GetCurrentThreadLongPtr() {
-  return &__hwasan_tls;
+Thread *GetCurrentThread() {
+  return (Thread *)pthread_getspecific(tsd_key);
 }
-#endif
 
+void SetCurrentThread(Thread *t) {
+  // Make sure that HwasanTSDDtor gets called at the end.
+  CHECK(tsd_key_inited);
+  // Make sure we do not reset the current Thread.
+  CHECK_EQ(0, pthread_getspecific(tsd_key));
+  pthread_setspecific(tsd_key, (void *)t);
+}
+#elif SANITIZER_ANDROID
+void HwasanTSDInit() {}
 Thread *GetCurrentThread() {
-  auto *R = (StackAllocationsRingBuffer*)GetCurrentThreadLongPtr();
-  return hwasanThreadList().GetThreadByBufferAddress((uptr)(R->Next()));
+  return (Thread*)*get_android_tls_ptr();
 }
 
+void SetCurrentThread(Thread *t) {
+  *get_android_tls_ptr() = (uptr)t;
+}
+#else
+#error unsupported configuration !HWASAN_WITH_INTERCEPTORS && !SANITIZER_ANDROID
+#endif
+
 struct AccessInfo {
   uptr addr;
   uptr size;
diff --git a/compiler-rt/lib/hwasan/hwasan_report.cc b/compiler-rt/lib/hwasan/hwasan_report.cc
index cf5f468c434..57115765a7c 100644
--- a/compiler-rt/lib/hwasan/hwasan_report.cc
+++ b/compiler-rt/lib/hwasan/hwasan_report.cc
@@ -16,7 +16,6 @@
 #include "hwasan_allocator.h"
 #include "hwasan_mapping.h"
 #include "hwasan_thread.h"
-#include "hwasan_thread_list.h"
 #include "sanitizer_common/sanitizer_allocator_internal.h"
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_flags.h"
@@ -36,31 +35,6 @@ static StackTrace GetStackTraceFromId(u32 id) {
   return res;
 }
 
-// A RAII object that holds a copy of the current thread stack ring buffer.
-// The actual stack buffer may change while we are iterating over it (for
-// example, Printf may call syslog() which can itself be built with hwasan).
-class SavedStackAllocations {
- public:
-  SavedStackAllocations(StackAllocationsRingBuffer *rb) {
-    uptr size = rb->size() * sizeof(uptr);
-    void *storage =
-        MmapAlignedOrDieOnFatalError(size, size * 2, "saved stack allocations");
-    new (&rb_) StackAllocationsRingBuffer(*rb, storage);
-  }
-
-  ~SavedStackAllocations() {
-    StackAllocationsRingBuffer *rb = get();
-    UnmapOrDie(rb->StartOfStorage(), rb->size() * sizeof(uptr));
-  }
-
-  StackAllocationsRingBuffer *get() {
-    return (StackAllocationsRingBuffer *)&rb_;
-  }
-
- private:
-  uptr rb_;
-};
-
 class Decorator: public __sanitizer::SanitizerCommonDecorator {
  public:
   Decorator() : SanitizerCommonDecorator() { }
@@ -89,9 +63,7 @@ uptr FindHeapAllocation(HeapAllocationsRingBuffer *rb,
   return 0;
 }
 
-void PrintAddressDescription(
-    uptr tagged_addr, uptr access_size,
-    StackAllocationsRingBuffer *current_stack_allocations) {
+void PrintAddressDescription(uptr tagged_addr, uptr access_size) {
   Decorator d;
   int num_descriptions_printed = 0;
   uptr untagged_addr = UntagAddr(tagged_addr);
@@ -137,7 +109,7 @@ void PrintAddressDescription(
     }
   }
 
-  hwasanThreadList().VisitAllLiveThreads([&](Thread *t) {
+  Thread::VisitAllLiveThreads([&](Thread *t) {
     // Scan all threads' ring buffers to find if it's a heap-use-after-free.
     HeapAllocationRecord har;
     if (uptr D = FindHeapAllocation(t->heap_allocations(), tagged_addr, &har)) {
@@ -173,25 +145,6 @@ void PrintAddressDescription(
       Printf("%s", d.Default());
       t->Announce();
 
-      // Temporary report section, needs to be improved.
-      Printf("Previosly allocated frames:\n");
-      auto *sa = (t == GetCurrentThread() && current_stack_allocations)
-                     ? current_stack_allocations
-                     : t->stack_allocations();
-      uptr frames = Min((uptr)flags()->stack_history_size, sa->size());
-      for (uptr i = 0; i < frames; i++) {
-        uptr record = (*sa)[i];
-        if (!record)
-          break;
-        uptr sp = (record >> 48) << 4;
-        uptr pc_mask = (1ULL << 48) - 1;
-        uptr pc = record & pc_mask;
-        uptr fixed_pc = StackTrace::GetNextInstructionPc(pc);
-        StackTrace stack(&fixed_pc, 1);
-        Printf("record: %p pc: %p sp: %p", record, pc, sp);
-        stack.Print();
-      }
-
       num_descriptions_printed++;
     }
   });
@@ -217,16 +170,13 @@ void ReportStats() {}
 void ReportInvalidAccessInsideAddressRange(const char *what, const void *start,
                                            uptr size, uptr offset) {
   ScopedErrorReportLock l;
-  SavedStackAllocations current_stack_allocations(
-      GetCurrentThread()->stack_allocations());
 
   Decorator d;
   Printf("%s", d.Warning());
   Printf("%sTag mismatch in %s%s%s at offset %zu inside [%p, %zu)%s\n",
          d.Warning(), d.Name(), what, d.Warning(), offset, start, size,
          d.Default());
-  PrintAddressDescription((uptr)start + offset, 1,
-                          current_stack_allocations.get());
+  PrintAddressDescription((uptr)start + offset, 1);
   // if (__sanitizer::Verbosity())
   //   DescribeMemoryRange(start, size);
 }
@@ -274,7 +224,7 @@ void ReportInvalidFree(StackTrace *stack, uptr tagged_addr) {
 
   stack->Print();
 
-  PrintAddressDescription(tagged_addr, 0, nullptr);
+  PrintAddressDescription(tagged_addr, 0);
 
   PrintTagsAroundAddr(tag_ptr);
 
@@ -285,8 +235,6 @@ void ReportInvalidFree(StackTrace *stack, uptr tagged_addr) {
 void ReportTagMismatch(StackTrace *stack, uptr tagged_addr, uptr access_size,
                        bool is_store) {
   ScopedErrorReportLock l;
-  SavedStackAllocations current_stack_allocations(
-      GetCurrentThread()->stack_allocations());
 
   Decorator d;
   Printf("%s", d.Error());
@@ -310,8 +258,7 @@ void ReportTagMismatch(StackTrace *stack, uptr tagged_addr, uptr access_size,
 
   stack->Print();
 
-  PrintAddressDescription(tagged_addr, access_size,
-                          current_stack_allocations.get());
+  PrintAddressDescription(tagged_addr, access_size);
   t->Announce();
 
   PrintTagsAroundAddr(tag_ptr);
diff --git a/compiler-rt/lib/hwasan/hwasan_thread.cc b/compiler-rt/lib/hwasan/hwasan_thread.cc
index 0d15c7e467c..1d008982d4d 100644
--- a/compiler-rt/lib/hwasan/hwasan_thread.cc
+++ b/compiler-rt/lib/hwasan/hwasan_thread.cc
@@ -9,7 +9,6 @@
 #include "sanitizer_common/sanitizer_placement_new.h"
 #include "sanitizer_common/sanitizer_tls_get_addr.h"
 
-
 namespace __hwasan {
 
 static u32 RandomSeed() {
@@ -25,52 +24,102 @@ static u32 RandomSeed() {
   return seed;
 }
 
-void Thread::Init(uptr stack_buffer_start, uptr stack_buffer_size) {
+Thread *Thread::thread_list_head;
+SpinMutex Thread::thread_list_mutex;
+Thread::ThreadStats Thread::thread_stats;
+
+void Thread::InsertIntoThreadList(Thread *t) {
+  CHECK(!t->next_);
+  SpinMutexLock l(&thread_list_mutex);
+  thread_stats.n_live_threads++;
+  thread_stats.total_stack_size += t->stack_size();
+  if (!thread_list_head) {
+    thread_list_head = t;
+    return;
+  }
+  Thread *last = thread_list_head;
+  while (last->next_)
+    last = last->next_;
+  last->next_ = t;
+}
+
+void Thread::RemoveFromThreadList(Thread *t) {
+  SpinMutexLock l(&thread_list_mutex);
+  thread_stats.n_live_threads--;
+  thread_stats.total_stack_size -= t->stack_size();
+  if (t == thread_list_head) {
+    thread_list_head = t->next_;
+    t->next_ = nullptr;
+    return;
+  }
+  Thread *prev = thread_list_head;
+  Thread *cur = prev->next_;
+  CHECK(cur);
+  while (cur) {
+    if (cur == t) {
+      prev->next_ = cur->next_;
+      return;
+    }
+    prev = cur;
+    cur = cur->next_;
+  }
+  CHECK(0 && "RemoveFromThreadList: thread not found");
+}
+
+void Thread::Create() {
   static u64 unique_id;
-  unique_id_ = unique_id++;
-  random_state_ = flags()->random_tags ? RandomSeed() : unique_id_;
+  uptr PageSize = GetPageSizeCached();
+  uptr size = RoundUpTo(sizeof(Thread), PageSize);
+  Thread *thread = (Thread*)MmapOrDie(size, __func__);
+  thread->destructor_iterations_ = GetPthreadDestructorIterations();
+  thread->unique_id_ = unique_id++;
+  thread->random_state_ =
+      flags()->random_tags ? RandomSeed() : thread->unique_id_;
   if (auto sz = flags()->heap_history_size)
-    heap_allocations_ = HeapAllocationsRingBuffer::New(sz);
+    thread->heap_allocations_ = HeapAllocationsRingBuffer::New(sz);
+  SetCurrentThread(thread);
+  thread->Init();
+  InsertIntoThreadList(thread);
+}
 
-  HwasanTSDThreadInit();  // Only needed with interceptors.
-  uptr *ThreadLong = GetCurrentThreadLongPtr();
-  // The following implicitly sets (this) as the current thread.
-  stack_allocations_ = new (ThreadLong)
-      StackAllocationsRingBuffer((void *)stack_buffer_start, stack_buffer_size);
-  // Check that it worked.
-  CHECK_EQ(GetCurrentThread(), this);
+uptr Thread::MemoryUsedPerThread() {
+  uptr res = sizeof(Thread);
+  if (auto sz = flags()->heap_history_size)
+    res += HeapAllocationsRingBuffer::SizeInBytes(sz);
+  return res;
+}
 
-  // ScopedTaggingDisable needs GetCurrentThread to be set up.
+void Thread::Init() {
+  // GetPthreadDestructorIterations may call malloc, so disable the tagging.
   ScopedTaggingDisabler disabler;
 
   // If this process is "init" (pid 1), /proc may not be mounted yet.
   if (IsMainThread() && !FileExists("/proc/self/maps")) {
     stack_top_ = stack_bottom_ = 0;
     tls_begin_ = tls_end_ = 0;
-  } else {
-    uptr tls_size;
-    uptr stack_size;
-    GetThreadStackAndTls(IsMainThread(), &stack_bottom_, &stack_size,
-                         &tls_begin_, &tls_size);
-    stack_top_ = stack_bottom_ + stack_size;
-    tls_end_ = tls_begin_ + tls_size;
-
-    int local;
-    CHECK(AddrIsInStack((uptr)&local));
+    return;
+  }
+
+  uptr tls_size;
+  uptr stack_size;
+  GetThreadStackAndTls(IsMainThread(), &stack_bottom_, &stack_size, &tls_begin_,
+                       &tls_size);
+  stack_top_ = stack_bottom_ + stack_size;
+  tls_end_ = tls_begin_ + tls_size;
+
+  int local;
+  CHECK(AddrIsInStack((uptr)&local));
+  CHECK(MemIsApp(stack_bottom_));
+  CHECK(MemIsApp(stack_top_ - 1));
+
+  if (stack_bottom_) {
     CHECK(MemIsApp(stack_bottom_));
     CHECK(MemIsApp(stack_top_ - 1));
-
-    if (stack_bottom_) {
-      CHECK(MemIsApp(stack_bottom_));
-      CHECK(MemIsApp(stack_top_ - 1));
-    }
   }
-
   if (flags()->verbose_threads) {
     if (IsMainThread()) {
-      Printf("sizeof(Thread): %zd sizeof(HeapRB): %zd sizeof(StackRB): %zd\n",
-             sizeof(Thread), heap_allocations_->SizeInBytes(),
-             stack_allocations_->size() * sizeof(uptr));
+      Printf("sizeof(Thread): %zd sizeof(RB): %zd\n", sizeof(Thread),
+             heap_allocations_->SizeInBytes());
     }
     Print("Creating  : ");
   }
@@ -88,8 +137,11 @@ void Thread::Destroy() {
     Print("Destroying: ");
   AllocatorSwallowThreadLocalCache(allocator_cache());
   ClearShadowForThreadStackAndTLS();
+  RemoveFromThreadList(this);
+  uptr size = RoundUpTo(sizeof(Thread), GetPageSizeCached());
   if (heap_allocations_)
     heap_allocations_->Delete();
+  UnmapOrDie(this, size);
   DTLS_Destroy();
 }
 
diff --git a/compiler-rt/lib/hwasan/hwasan_thread.h b/compiler-rt/lib/hwasan/hwasan_thread.h
index 4830473f4aa..6a27ba6f216 100644
--- a/compiler-rt/lib/hwasan/hwasan_thread.h
+++ b/compiler-rt/lib/hwasan/hwasan_thread.h
@@ -16,15 +16,12 @@
 
 #include "hwasan_allocator.h"
 #include "sanitizer_common/sanitizer_common.h"
-#include "sanitizer_common/sanitizer_ring_buffer.h"
 
 namespace __hwasan {
 
-typedef __sanitizer::CompactRingBuffer<uptr> StackAllocationsRingBuffer;
-
 class Thread {
  public:
-  void Init(uptr stack_buffer_start, uptr stack_buffer_size);  // Must be called from the thread itself.
+  static void Create();  // Must be called from the thread itself.
   void Destroy();
 
   uptr stack_top() { return stack_top_; }
@@ -51,15 +48,27 @@ class Thread {
   void LeaveInterceptorScope() { in_interceptor_scope_--; }
 
   AllocatorCache *allocator_cache() { return &allocator_cache_; }
-  HeapAllocationsRingBuffer *heap_allocations() { return heap_allocations_; }
-  StackAllocationsRingBuffer *stack_allocations() { return stack_allocations_; }
+  HeapAllocationsRingBuffer *heap_allocations() {
+    return heap_allocations_;
+  }
 
   tag_t GenerateRandomTag();
 
+  int destructor_iterations_;
   void DisableTagging() { tagging_disabled_++; }
   void EnableTagging() { tagging_disabled_--; }
   bool TaggingIsDisabled() const { return tagging_disabled_; }
 
+  template <class CB>
+  static void VisitAllLiveThreads(CB cb) {
+    SpinMutexLock l(&thread_list_mutex);
+    Thread *t = thread_list_head;
+    while (t) {
+      cb(t);
+      t = t->next_;
+    }
+  }
+
   u64 unique_id() const { return unique_id_; }
   void Announce() {
     if (announced_) return;
@@ -67,9 +76,22 @@ class Thread {
     Print("Thread: ");
   }
 
+  struct ThreadStats {
+    uptr n_live_threads;
+    uptr total_stack_size;
+  };
+
+  static ThreadStats GetThreadStats() {
+    SpinMutexLock l(&thread_list_mutex);
+    return thread_stats;
+  }
+
+  static uptr MemoryUsedPerThread();
+
  private:
   // NOTE: There is no Thread constructor. It is allocated
   // via mmap() and *must* be valid in zero-initialized state.
+  void Init();
   void ClearShadowForThreadStackAndTLS();
   void Print(const char *prefix);
   uptr stack_top_;
@@ -86,23 +108,23 @@ class Thread {
 
   AllocatorCache allocator_cache_;
   HeapAllocationsRingBuffer *heap_allocations_;
-  StackAllocationsRingBuffer *stack_allocations_;
 
   static void InsertIntoThreadList(Thread *t);
   static void RemoveFromThreadList(Thread *t);
   Thread *next_;  // All live threads form a linked list.
+  static SpinMutex thread_list_mutex;
+  static Thread *thread_list_head;
+  static ThreadStats thread_stats;
 
   u64 unique_id_;  // counting from zero.
 
   u32 tagging_disabled_;  // if non-zero, malloc uses zero tag in this thread.
 
   bool announced_;
-
-  friend struct ThreadListHead;
 };
 
 Thread *GetCurrentThread();
-uptr *GetCurrentThreadLongPtr();
+void SetCurrentThread(Thread *t);
 
 struct ScopedTaggingDisabler {
   ScopedTaggingDisabler() { GetCurrentThread()->DisableTagging(); }
diff --git a/compiler-rt/lib/hwasan/hwasan_thread_list.cc b/compiler-rt/lib/hwasan/hwasan_thread_list.cc
deleted file mode 100644
index a31eee84ed9..00000000000
--- a/compiler-rt/lib/hwasan/hwasan_thread_list.cc
+++ /dev/null
@@ -1,15 +0,0 @@
-#include "hwasan_thread_list.h"
-
-namespace __hwasan {
-static ALIGNED(16) char thread_list_placeholder[sizeof(HwasanThreadList)];
-static HwasanThreadList *hwasan_thread_list;
-
-HwasanThreadList &hwasanThreadList() { return *hwasan_thread_list; }
-
-void InitThreadList(uptr storage, uptr size) {
-  CHECK(hwasan_thread_list == nullptr);
-  hwasan_thread_list =
-      new (thread_list_placeholder) HwasanThreadList(storage, size);
-}
-
-} // namespace
diff --git a/compiler-rt/lib/hwasan/hwasan_thread_list.h b/compiler-rt/lib/hwasan/hwasan_thread_list.h
deleted file mode 100644
index 53747b51fd6..00000000000
--- a/compiler-rt/lib/hwasan/hwasan_thread_list.h
+++ /dev/null
@@ -1,200 +0,0 @@
-//===-- hwasan_thread_list.h ------------------------------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file is a part of HWAddressSanitizer.
-//
-//===----------------------------------------------------------------------===//
-
-// HwasanThreadList is a registry for live threads, as well as an allocator for
-// HwasanThread objects and their stack history ring buffers. There are
-// constraints on memory layout of the shadow region and CompactRingBuffer that
-// are part of the ABI contract between compiler-rt and llvm.
-//
-// * Start of the shadow memory region is aligned to 2**kShadowBaseAlignment.
-// * All stack ring buffers are located within (2**kShadowBaseAlignment)
-// sized region below and adjacent to the shadow region.
-// * Each ring buffer has a size of (2**N)*4096 where N is in [0, 8), and is
-// aligned to twice its size. The value of N can be different for each buffer.
-//
-// These constrains guarantee that, given an address A of any element of the
-// ring buffer,
-//     A_next = (A + sizeof(uptr)) & ~((1 << (N + 13)) - 1)
-//   is the address of the next element of that ring buffer (with wrap-around).
-// And, with K = kShadowBaseAlignment,
-//     S = (A | ((1 << K) - 1)) + 1
-//   (align up to kShadowBaseAlignment) is the start of the shadow region.
-//
-// These calculations are used in compiler instrumentation to update the ring
-// buffer and obtain the base address of shadow using only two inputs: address
-// of the current element of the ring buffer, and N (i.e. size of the ring
-// buffer). Since the value of N is very limited, we pack both inputs into a
-// single thread-local word as
-//   (1 << (N + 56)) | A
-// See the implementation of class CompactRingBuffer, which is what is stored in
-// said thread-local word.
-//
-// Note the unusual way of aligning up the address of the shadow:
-//   (A | ((1 << K) - 1)) + 1
-// It is only correct if A is not already equal to the shadow base address, but
-// it saves 2 instructions on AArch64.
-
-#include "hwasan.h"
-#include "hwasan_allocator.h"
-#include "hwasan_flags.h"
-#include "hwasan_thread.h"
-
-#include "sanitizer_common/sanitizer_placement_new.h"
-
-namespace __hwasan {
-
-static uptr RingBufferSize() {
-  uptr desired_bytes = flags()->stack_history_size * sizeof(uptr);
-  // FIXME: increase the limit to 8 once this bug is fixed:
-  // https://bugs.llvm.org/show_bug.cgi?id=39030
-  for (int shift = 1; shift < 7; ++shift) {
-    uptr size = 4096 * (1ULL << shift);
-    if (size >= desired_bytes)
-      return size;
-  }
-  Printf("stack history size too large: %d\n", flags()->stack_history_size);
-  CHECK(0);
-  return 0;
-}
-
-struct ThreadListHead {
-  Thread *list_;
-
-  ThreadListHead() : list_(nullptr) {}
-
-  void Push(Thread *t) {
-    t->next_ = list_;
-    list_ = t;
-  }
-
-  Thread *Pop() {
-    Thread *t = list_;
-    if (t)
-      list_ = t->next_;
-    return t;
-  }
-
-  void Remove(Thread *t) {
-    Thread **cur = &list_;
-    while (*cur != t) cur = &(*cur)->next_;
-    CHECK(*cur && "thread not found");
-    *cur = (*cur)->next_;
-  }
-
-  template <class CB>
-  void ForEach(CB cb) {
-    Thread *t = list_;
-    while (t) {
-      cb(t);
-      t = t->next_;
-    }
-  }
-};
-
-struct ThreadStats {
-  uptr n_live_threads;
-  uptr total_stack_size;
-};
-
-class HwasanThreadList {
- public:
-  HwasanThreadList(uptr storage, uptr size)
-      : free_space_(storage),
-        free_space_end_(storage + size),
-        ring_buffer_size_(RingBufferSize()) {}
-
-  Thread *CreateCurrentThread() {
-    Thread *t;
-    {
-      SpinMutexLock l(&list_mutex_);
-      t = free_list_.Pop();
-      if (t)
-        internal_memset((void *)t, 0, sizeof(Thread) + ring_buffer_size_);
-      else
-        t = AllocThread();
-      live_list_.Push(t);
-    }
-    t->Init((uptr)(t + 1), ring_buffer_size_);
-    AddThreadStats(t);
-    return t;
-  }
-
-  void ReleaseThread(Thread *t) {
-    // FIXME: madvise away the ring buffer?
-    RemoveThreadStats(t);
-    t->Destroy();
-    SpinMutexLock l(&list_mutex_);
-    live_list_.Remove(t);
-    free_list_.Push(t);
-  }
-
-  Thread *GetThreadByBufferAddress(uptr p) {
-    uptr align = ring_buffer_size_ * 2;
-    return (Thread *)(RoundDownTo(p, align) - sizeof(Thread));
-  }
-
-  uptr MemoryUsedPerThread() {
-    uptr res = sizeof(Thread) + ring_buffer_size_;
-    if (auto sz = flags()->heap_history_size)
-      res += HeapAllocationsRingBuffer::SizeInBytes(sz);
-    return res;
-  }
-
-  template <class CB>
-  void VisitAllLiveThreads(CB cb) {
-    SpinMutexLock l(&list_mutex_);
-    live_list_.ForEach(cb);
-  }
-
-  void AddThreadStats(Thread *t) {
-    SpinMutexLock l(&stats_mutex_);
-    stats_.n_live_threads++;
-    stats_.total_stack_size += t->stack_size();
-  }
-
-  void RemoveThreadStats(Thread *t) {
-    SpinMutexLock l(&stats_mutex_);
-    stats_.n_live_threads--;
-    stats_.total_stack_size -= t->stack_size();
-  }
-
-  ThreadStats GetThreadStats() {
-    SpinMutexLock l(&stats_mutex_);
-    return stats_;
-  }
-
- private:
-  Thread *AllocThread() {
-    uptr align = ring_buffer_size_ * 2;
-    uptr ring_buffer_start = RoundUpTo(free_space_ + sizeof(Thread), align);
-    free_space_ = ring_buffer_start + ring_buffer_size_;
-    CHECK(free_space_ <= free_space_end_ && "out of thread memory");
-    return (Thread *)(ring_buffer_start - sizeof(Thread));
-  }
-
-  uptr free_space_;
-  uptr free_space_end_;
-  uptr ring_buffer_size_;
-
-  ThreadListHead free_list_;
-  ThreadListHead live_list_;
-  SpinMutex list_mutex_;
-
-  ThreadStats stats_;
-  SpinMutex stats_mutex_;
-};
-
-void InitThreadList(uptr storage, uptr size);
-HwasanThreadList &hwasanThreadList();
-
-} // namespace
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_ring_buffer.h b/compiler-rt/lib/sanitizer_common/sanitizer_ring_buffer.h
index d15f27fd4a8..c4649c2be9f 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_ring_buffer.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_ring_buffer.h
@@ -72,91 +72,12 @@ class RingBuffer {
   // L: last_, always points to the last data element.
   // N: next_, initially equals to last_, is decremented on every push,
   //    wraps around if it's less or equal than its own address.
+
   T *last_;
   T *next_;
   T data_[1];  // flexible array.
 };
 
-// A ring buffer with externally provided storage that encodes its state in 8
-// bytes. Has significant constraints on size and alignment of storage.
-// See a comment in hwasan/hwasan_thread_list.h for the motivation behind this.
-#if SANITIZER_WORDSIZE == 64
-template <class T>
-class CompactRingBuffer {
-  // Top byte of long_ stores the buffer size in pages.
-  // Lower bytes store the address of the next buffer element.
-  static constexpr int kPageSizeBits = 12;
-  static constexpr int kSizeShift = 56;
-  static constexpr uptr kNextMask = (1ULL << kSizeShift) - 1;
-
-  uptr GetStorageSize() const { return (long_ >> kSizeShift) << kPageSizeBits; }
-
-  void Init(void *storage, uptr size) {
-    CHECK_EQ(sizeof(CompactRingBuffer<T>), sizeof(void *));
-    CHECK(IsPowerOfTwo(size));
-    CHECK_GE(size, 1 << kPageSizeBits);
-    CHECK_LE(size, 128 << kPageSizeBits);
-    CHECK_EQ(size % 4096, 0);
-    CHECK_EQ(size % sizeof(T), 0);
-    CHECK_EQ((uptr)storage % (size * 2), 0);
-    long_ = (uptr)storage | ((size >> kPageSizeBits) << kSizeShift);
-  }
-
-  void SetNext(const T *next) {
-    long_ = (long_ & ~kNextMask) | (uptr)next;
-  }
-
- public:
-  CompactRingBuffer(void *storage, uptr size) {
-    Init(storage, size);
-  }
-
-  // A copy constructor of sorts.
-  CompactRingBuffer(const CompactRingBuffer &other, void *storage) {
-    uptr size = other.GetStorageSize();
-    internal_memcpy(storage, other.StartOfStorage(), size);
-    Init(storage, size);
-    uptr Idx = other.Next() - (const T *)other.StartOfStorage();
-    SetNext((const T *)storage + Idx);
-  }
-
-  T *Next() const { return (T *)(long_ & kNextMask); }
-
-  void *StartOfStorage() const {
-    return (void *)((uptr)Next() & ~(GetStorageSize() - 1));
-  }
-
-  void *EndOfStorage() const {
-    return (void *)((uptr)StartOfStorage() + GetStorageSize());
-  }
-
-  uptr size() const { return GetStorageSize() / sizeof(T); }
-
-  void push(T t) {
-    T *next = Next();
-    *next = t;
-    next++;
-    next = (T *)((uptr)next & ~GetStorageSize());
-    SetNext(next);
-  }
-
-  T operator[](uptr Idx) const {
-    CHECK_LT(Idx, size());
-    const T *Begin = (const T *)StartOfStorage();
-    sptr StorageIdx = Next() - Begin;
-    StorageIdx -= (sptr)(Idx + 1);
-    if (StorageIdx < 0)
-      StorageIdx += size();
-    return Begin[StorageIdx];
-  }
-
- public:
-  ~CompactRingBuffer() {}
-  CompactRingBuffer(const CompactRingBuffer &) = delete;
-
-  uptr long_;
-};
-#endif
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_RING_BUFFER_H
diff --git a/compiler-rt/lib/sanitizer_common/tests/sanitizer_ring_buffer_test.cc b/compiler-rt/lib/sanitizer_common/tests/sanitizer_ring_buffer_test.cc
index 80aa57c5290..a9286ce6d3e 100644
--- a/compiler-rt/lib/sanitizer_common/tests/sanitizer_ring_buffer_test.cc
+++ b/compiler-rt/lib/sanitizer_common/tests/sanitizer_ring_buffer_test.cc
@@ -66,7 +66,6 @@ template <class T> void TestRB() {
 #undef EXPECT_RING_BUFFER
 }
 
-#if SANITIZER_WORDSIZE == 64
 TEST(RingBuffer, int64) {
   TestRB<int64_t>();
 }
@@ -75,25 +74,4 @@ TEST(RingBuffer, LargeStruct) {
   TestRB<LargeStruct>();
 }
 
-template<typename T>
-CompactRingBuffer<T> *AllocCompactRingBuffer(size_t count) {
-  size_t sz = sizeof(T) * count;
-  EXPECT_EQ(0ULL, sz % 4096);
-  void *p = MmapAlignedOrDieOnFatalError(sz, sz * 2, "CompactRingBuffer");
-  return new CompactRingBuffer<T>(p, sz);
-}
-
-TEST(CompactRingBuffer, int64) {
-  const size_t page_sizes[] = {1, 2, 4, 128};
-
-  for (size_t pages : page_sizes) {
-    size_t count = 4096 * pages / sizeof(int64_t);
-    auto R = AllocCompactRingBuffer<int64_t>(count);
-    int64_t top = count * 3 + 13;
-    for (int64_t i = 0; i < top; ++i) R->push(i);
-    for (int64_t i = 0; i < (int64_t)count; ++i)
-      EXPECT_EQ(top - i - 1, (*R)[i]);
-  }
-}
-#endif
 }  // namespace __sanitizer
diff --git a/compiler-rt/test/hwasan/TestCases/deep-recursion.c b/compiler-rt/test/hwasan/TestCases/deep-recursion.c
deleted file mode 100644
index 1ac0f5b15ca..00000000000
--- a/compiler-rt/test/hwasan/TestCases/deep-recursion.c
+++ /dev/null
@@ -1,73 +0,0 @@
-// RUN: %clang_hwasan -O1 %s -o %t
-// RUN: %env_hwasan_opts=stack_history_size=1 not %run %t 2>&1 | FileCheck %s --check-prefix=D1
-// RUN: %env_hwasan_opts=stack_history_size=2 not %run %t 2>&1 | FileCheck %s --check-prefix=D2
-// RUN: %env_hwasan_opts=stack_history_size=3 not %run %t 2>&1 | FileCheck %s --check-prefix=D3
-// RUN: %env_hwasan_opts=stack_history_size=5 not %run %t 2>&1 | FileCheck %s --check-prefix=D5
-// RUN:                                       not %run %t 2>&1 | FileCheck %s --check-prefix=DEFAULT
-
-// REQUIRES: stable-runtime
-
-#include <stdlib.h>
-// At least -O1 is needed for this function to not have a stack frame on
-// AArch64.
-void USE(void *x) { // pretend_to_do_something(void *x)
-  __asm__ __volatile__("" : : "r" (x) : "memory");
-}
-
-volatile int four = 4;
-
-__attribute__((noinline)) void OOB() { int x[4]; x[four] = 0; USE(&x[0]); }
-__attribute__((noinline)) void FUNC1() { int x; USE(&x); OOB(); }
-__attribute__((noinline)) void FUNC2() { int x; USE(&x); FUNC1(); }
-__attribute__((noinline)) void FUNC3() { int x; USE(&x); FUNC2(); }
-__attribute__((noinline)) void FUNC4() { int x; USE(&x); FUNC3(); }
-__attribute__((noinline)) void FUNC5() { int x; USE(&x); FUNC4(); }
-__attribute__((noinline)) void FUNC6() { int x; USE(&x); FUNC5(); }
-__attribute__((noinline)) void FUNC7() { int x; USE(&x); FUNC6(); }
-__attribute__((noinline)) void FUNC8() { int x; USE(&x); FUNC7(); }
-__attribute__((noinline)) void FUNC9() { int x; USE(&x); FUNC8(); }
-__attribute__((noinline)) void FUNC10() { int x; USE(&x); FUNC9(); }
-
-int main() { FUNC10(); }
-
-// D1: Previosly allocated frames
-// D1: in OOB
-// D1-NOT: in FUNC
-// D1: Memory tags around the buggy address
-
-// D2: Previosly allocated frames
-// D2: in OOB
-// D2: in FUNC1
-// D2-NOT: in FUNC
-// D2: Memory tags around the buggy address
-
-// D3: Previosly allocated frames
-// D3: in OOB
-// D3: in FUNC1
-// D3: in FUNC2
-// D3-NOT: in FUNC
-// D3: Memory tags around the buggy address
-
-// D5: Previosly allocated frames
-// D5: in OOB
-// D5: in FUNC1
-// D5: in FUNC2
-// D5: in FUNC3
-// D5: in FUNC4
-// D5-NOT: in FUNC
-// D5: Memory tags around the buggy address
-
-// DEFAULT: Previosly allocated frames
-// DEFAULT: in OOB
-// DEFAULT: in FUNC1
-// DEFAULT: in FUNC2
-// DEFAULT: in FUNC3
-// DEFAULT: in FUNC4
-// DEFAULT: in FUNC5
-// DEFAULT: in FUNC6
-// DEFAULT: in FUNC7
-// DEFAULT: in FUNC8
-// DEFAULT: in FUNC9
-// DEFAULT: in FUNC10
-// DEFAULT-NOT: in FUNC
-// DEFAULT: Memory tags around the buggy address
diff --git a/compiler-rt/test/hwasan/TestCases/rich-stack.c b/compiler-rt/test/hwasan/TestCases/rich-stack.c
deleted file mode 100644
index 6787d57769f..00000000000
--- a/compiler-rt/test/hwasan/TestCases/rich-stack.c
+++ /dev/null
@@ -1,66 +0,0 @@
-// Test how stack frames are reported (not fully implemented yet).
-// RUN: %clang_hwasan %s -o %t
-// RUN: not %run %t 3 2 -1 2>&1 | FileCheck %s --check-prefix=R321
-// REQUIRES: stable-runtime
-#include <stdint.h>
-#include <stdlib.h>
-void USE(void *x) { // pretend_to_do_something(void *x)
-  __asm__ __volatile__("" : : "r" (x) : "memory");
-}
-void USE2(void *a, void *b) { USE(a); USE(b); }
-void USE4(void *a, void *b, void *c, void *d) { USE2(a, b); USE2(c, d); }
-
-void BAR(int depth, int err_depth, int offset);
-
-uint64_t *leaked_ptr;
-
-void FOO(int depth, int err_depth, int offset) {
-  uint8_t v1;
-  uint16_t v2;
-  uint32_t v4;
-  uint64_t v8;
-  uint64_t v16[2];
-  uint64_t v32[4];
-  uint64_t v48[3];
-  USE4(&v1, &v2, &v4, &v8);  USE4(&v16, &v32, &v48, 0);
-  leaked_ptr = &v16[0];
-  if (depth)
-    BAR(depth - 1, err_depth, offset);
-
-  if (err_depth == depth)
-    v16[offset] = 0;  // maybe OOB.
-  if (err_depth == -depth)
-    leaked_ptr[offset] = 0; // maybe UAR.
-  USE(&v16);
-}
-
-void BAR(int depth, int err_depth, int offset) {
-  uint64_t x16[2];
-  uint64_t x32[4];
-  USE2(&x16, &x32);
-  leaked_ptr = &x16[0];
-  if (depth)
-    FOO(depth - 1, err_depth, offset);
-  if (err_depth == depth)
-    x16[offset] = 0;  // maybe OOB
-  if (err_depth == -depth)
-    leaked_ptr[offset] = 0;  // maybe UAR
-  USE(&x16);
-}
-
-
-int main(int argc, char **argv) {
-  if (argc != 4) return -1;
-  int depth = atoi(argv[1]);
-  int err_depth = atoi(argv[2]);
-  int offset = atoi(argv[3]);
-  FOO(depth, err_depth, offset);
-  return 0;
-}
-
-// R321: HWAddressSanitizer: tag-mismatch
-// R321-NEXT: WRITE of size 8
-// R321-NEXT: in BAR
-// R321-NEXT: in FOO
-// R321-NEXT: in main
-// R321: is located in stack of thread T0
diff --git a/compiler-rt/test/hwasan/TestCases/stack-history-length.c b/compiler-rt/test/hwasan/TestCases/stack-history-length.c
deleted file mode 100644
index f4c0b036fc3..00000000000
--- a/compiler-rt/test/hwasan/TestCases/stack-history-length.c
+++ /dev/null
@@ -1,36 +0,0 @@
-// RUN: %clang_hwasan -O1 -DX=2046 %s -o %t.2046
-// RUN: %clang_hwasan -O1 -DX=2047 %s -o %t.2047
-// RUN: %env_hwasan_opts=stack_history_size=2048 not %run %t.2046 2>&1 | FileCheck %s --check-prefix=YES
-// RUN: %env_hwasan_opts=stack_history_size=2048 not %run %t.2047 2>&1 | FileCheck %s --check-prefix=NO
-
-// REQUIRES: stable-runtime
-
-#include <stdlib.h>
-
-void USE(void *x) { // pretend_to_do_something(void *x)
-  __asm__ __volatile__("" : : "r" (x) : "memory");
-}
-
-volatile int four = 4;
-__attribute__((noinline)) void FUNC0() { int x[4]; USE(&x[0]); }
-__attribute__((noinline)) void FUNC() { int x[4]; USE(&x[0]); }
-__attribute__((noinline)) void OOB() { int x[4]; x[four] = 0; USE(&x[0]); }
-
-int main() {
-  // FUNC0 is X+2's element of the ring buffer.
-  // If runtime buffer size is less than it, FUNC0 record will be lost.
-  FUNC0();
-  for (int i = 0; i < X; ++i)
-    FUNC();
-  OOB();
-}
-
-// YES: Previosly allocated frames
-// YES: OOB
-// YES: FUNC
-// YES: FUNC0
-
-// NO: Previosly allocated frames
-// NO: OOB
-// NO: FUNC
-// NO-NOT: FUNC0
diff --git a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
index 0cbebbd2237..f3d8ae45bd1 100644
--- a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
@@ -63,8 +63,6 @@ static const uint64_t kDynamicShadowSentinel =
     std::numeric_limits<uint64_t>::max();
 static const unsigned kPointerTagShift = 56;
 
-static const unsigned kShadowBaseAlignment = 32;
-
 static cl::opt<std::string> ClMemoryAccessCallbackPrefix(
     "hwasan-memory-access-callback-prefix",
     cl::desc("Prefix for memory access callbacks"), cl::Hidden,
@@ -134,18 +132,6 @@ static cl::opt<bool>
                 cl::desc("Access dynamic shadow through an ifunc global on "
                          "platforms that support this"),
                 cl::Hidden, cl::init(false));
-
-static cl::opt<bool> ClWithTls(
-    "hwasan-with-tls",
-    cl::desc("Access dynamic shadow through an thread-local pointer on "
-             "platforms that support this"),
-    cl::Hidden, cl::init(true));
-
-static cl::opt<bool>
-    ClRecordStackHistory("hwasan-record-stack-history",
-                         cl::desc("Record stack frames with tagged allocations "
-                                  "in a thread-local ring buffer"),
-                         cl::Hidden, cl::init(true));
 namespace {
 
 /// An instrumentation pass implementing detection of addressability bugs
@@ -169,7 +155,7 @@ public:
 
   void initializeCallbacks(Module &M);
 
-  Value *getDynamicShadowNonTls(IRBuilder<> &IRB);
+  void maybeInsertDynamicShadowAtFunctionEntry(Function &F);
 
   void untagPointerOperand(Instruction *I, Value *Addr);
   Value *memToShadow(Value *Shadow, Type *Ty, IRBuilder<> &IRB);
@@ -186,16 +172,13 @@ public:
   Value *tagPointer(IRBuilder<> &IRB, Type *Ty, Value *PtrLong, Value *Tag);
   Value *untagPointer(IRBuilder<> &IRB, Value *PtrLong);
   bool instrumentStack(SmallVectorImpl<AllocaInst *> &Allocas,
-                       SmallVectorImpl<Instruction *> &RetVec, Value *StackTag);
+                       SmallVectorImpl<Instruction *> &RetVec);
   Value *getNextTagWithCall(IRBuilder<> &IRB);
   Value *getStackBaseTag(IRBuilder<> &IRB);
   Value *getAllocaTag(IRBuilder<> &IRB, Value *StackTag, AllocaInst *AI,
                      unsigned AllocaNo);
   Value *getUARTag(IRBuilder<> &IRB, Value *StackTag);
 
-  Value *getHwasanThreadSlotPtr(IRBuilder<> &IRB, Type *Ty);
-  Value *emitPrologue(IRBuilder<> &IRB, bool WithFrameRecord);
-
 private:
   LLVMContext *C;
   Triple TargetTriple;
@@ -205,14 +188,10 @@ private:
   /// If InGlobal is true, then
   ///   extern char __hwasan_shadow[];
   ///   shadow = (mem >> Scale) + &__hwasan_shadow
-  /// If InTls is true, then
-  ///   extern char *__hwasan_tls;
-  ///   shadow = (mem >> Scale) + align_up(__hwasan_shadow, kShadowBaseAlignment)
   struct ShadowMapping {
     int Scale;
     uint64_t Offset;
     bool InGlobal;
-    bool InTls;
 
     void init(Triple &TargetTriple);
     unsigned getAllocaAlignment() const { return 1U << Scale; }
@@ -237,7 +216,6 @@ private:
   Constant *ShadowGlobal;
 
   Value *LocalDynamicShadow = nullptr;
-  GlobalValue *ThreadPtrGlobal = nullptr;
 };
 
 } // end anonymous namespace
@@ -285,12 +263,6 @@ bool HWAddressSanitizer::doInitialization(Module &M) {
                                             /*InitArgs=*/{});
     appendToGlobalCtors(M, HwasanCtorFunction, 0);
   }
-  if (!TargetTriple.isAndroid())
-    appendToCompilerUsed(
-        M, ThreadPtrGlobal = new GlobalVariable(
-               M, IntptrTy, false, GlobalVariable::ExternalLinkage, nullptr,
-               "__hwasan_tls", nullptr, GlobalVariable::InitialExecTLSModel));
-
   return true;
 }
 
@@ -325,11 +297,12 @@ void HWAddressSanitizer::initializeCallbacks(Module &M) {
                                        ArrayType::get(IRB.getInt8Ty(), 0));
 }
 
-Value *HWAddressSanitizer::getDynamicShadowNonTls(IRBuilder<> &IRB) {
+void HWAddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
   // Generate code only when dynamic addressing is needed.
   if (Mapping.Offset != kDynamicShadowSentinel)
-    return nullptr;
+    return;
 
+  IRBuilder<> IRB(&F.front().front());
   if (Mapping.InGlobal) {
     // An empty inline asm with input reg == output reg.
     // An opaque pointer-to-int cast, basically.
@@ -337,12 +310,11 @@ Value *HWAddressSanitizer::getDynamicShadowNonTls(IRBuilder<> &IRB) {
         FunctionType::get(IntptrTy, {ShadowGlobal->getType()}, false),
         StringRef(""), StringRef("=r,0"),
         /*hasSideEffects=*/false);
-    return IRB.CreateCall(Asm, {ShadowGlobal}, ".hwasan.shadow");
+    LocalDynamicShadow = IRB.CreateCall(Asm, {ShadowGlobal}, ".hwasan.shadow");
   } else {
-    Value *GlobalDynamicAddress =
-        IRB.GetInsertBlock()->getParent()->getParent()->getOrInsertGlobal(
-            kHwasanShadowMemoryDynamicAddress, IntptrTy);
-    return IRB.CreateLoad(GlobalDynamicAddress);
+    Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
+        kHwasanShadowMemoryDynamicAddress, IntptrTy);
+    LocalDynamicShadow = IRB.CreateLoad(GlobalDynamicAddress);
   }
 }
 
@@ -591,7 +563,7 @@ Value *HWAddressSanitizer::getNextTagWithCall(IRBuilder<> &IRB) {
 
 Value *HWAddressSanitizer::getStackBaseTag(IRBuilder<> &IRB) {
   if (ClGenerateTagsWithCalls)
-    return getNextTagWithCall(IRB);
+    return nullptr;
   // FIXME: use addressofreturnaddress (but implement it in aarch64 backend
   // first).
   Module *M = IRB.GetInsertBlock()->getParent()->getParent();
@@ -659,88 +631,15 @@ Value *HWAddressSanitizer::untagPointer(IRBuilder<> &IRB, Value *PtrLong) {
   return UntaggedPtrLong;
 }
 
-Value *HWAddressSanitizer::getHwasanThreadSlotPtr(IRBuilder<> &IRB, Type *Ty) {
-  Module *M = IRB.GetInsertBlock()->getParent()->getParent();
-  if (TargetTriple.isAArch64() && TargetTriple.isAndroid()) {
-    Function *ThreadPointerFunc =
-        Intrinsic::getDeclaration(M, Intrinsic::thread_pointer);
-    Value *SlotPtr = IRB.CreatePointerCast(
-        IRB.CreateConstGEP1_32(IRB.CreateCall(ThreadPointerFunc), 0x40),
-        Ty->getPointerTo(0));
-    return SlotPtr;
-  }
-  if (ThreadPtrGlobal)
-    return ThreadPtrGlobal;
-
-
-  return nullptr;
-}
-
-Value *HWAddressSanitizer::emitPrologue(IRBuilder<> &IRB,
-                                        bool WithFrameRecord) {
-  if (!Mapping.InTls)
-    return getDynamicShadowNonTls(IRB);
-
-  Value *SlotPtr = getHwasanThreadSlotPtr(IRB, IntptrTy);
-  assert(SlotPtr);
-
-  Value *ThreadLong = IRB.CreateLoad(SlotPtr);
-  // Extract the address field from ThreadLong. Unnecessary on AArch64 with TBI.
-  Value *ThreadLongMaybeUntagged =
-      TargetTriple.isAArch64() ? ThreadLong : untagPointer(IRB, ThreadLong);
-
-  if (WithFrameRecord) {
-    // Prepare ring buffer data.
-    Function *F = IRB.GetInsertBlock()->getParent();
-    auto PC = IRB.CreatePtrToInt(F, IntptrTy);
-    auto GetStackPointerFn =
-        Intrinsic::getDeclaration(F->getParent(), Intrinsic::frameaddress);
-    Value *SP = IRB.CreatePtrToInt(
-        IRB.CreateCall(GetStackPointerFn,
-                       {Constant::getNullValue(IRB.getInt32Ty())}),
-        IntptrTy);
-    // Mix SP and PC. TODO: also add the tag to the mix.
-    // Assumptions:
-    // PC is 0x0000PPPPPPPPPPPP  (48 bits are meaningful, others are zero)
-    // SP is 0xsssssssssssSSSS0  (4 lower bits are zero)
-    // We only really need ~20 lower non-zero bits (SSSS), so we mix like this:
-    //       0xSSSSPPPPPPPPPPPP
-    SP = IRB.CreateShl(SP, 44);
-
-    // Store data to ring buffer.
-    Value *RecordPtr =
-        IRB.CreateIntToPtr(ThreadLongMaybeUntagged, IntptrTy->getPointerTo(0));
-    IRB.CreateStore(IRB.CreateOr(PC, SP), RecordPtr);
-
-    // Update the ring buffer. Top byte of ThreadLong defines the size of the
-    // buffer in pages, it must be a power of two, and the start of the buffer
-    // must be aligned by twice that much. Therefore wrap around of the ring
-    // buffer is simply Addr &= ~((ThreadLong >> 56) << 12).
-    // The use of AShr instead of LShr is due to
-    //   https://bugs.llvm.org/show_bug.cgi?id=39030
-    // Runtime library makes sure not to use the highest bit.
-    Value *WrapMask = IRB.CreateXor(
-        IRB.CreateShl(IRB.CreateAShr(ThreadLong, 56), 12, "", true, true),
-        ConstantInt::get(IntptrTy, (uint64_t)-1));
-    Value *ThreadLongNew = IRB.CreateAnd(
-        IRB.CreateAdd(ThreadLong, ConstantInt::get(IntptrTy, 8)), WrapMask);
-    IRB.CreateStore(ThreadLongNew, SlotPtr);
-  }
-
-  // Get shadow base address by aligning RecordPtr up.
-  // Note: this is not correct if the pointer is already aligned.
-  // Runtime library will make sure this never happens.
-  Value *ShadowBase = IRB.CreateAdd(
-      IRB.CreateOr(
-          ThreadLongMaybeUntagged,
-          ConstantInt::get(IntptrTy, (1UL << kShadowBaseAlignment) - 1)),
-      ConstantInt::get(IntptrTy, 1), "hwasan.shadow");
-  return ShadowBase;
-}
-
 bool HWAddressSanitizer::instrumentStack(
     SmallVectorImpl<AllocaInst *> &Allocas,
-    SmallVectorImpl<Instruction *> &RetVec, Value *StackTag) {
+    SmallVectorImpl<Instruction *> &RetVec) {
+  Function *F = Allocas[0]->getParent()->getParent();
+  Instruction *InsertPt = &*F->getEntryBlock().begin();
+  IRBuilder<> IRB(InsertPt);
+
+  Value *StackTag = getStackBaseTag(IRB);
+
   // Ideally, we want to calculate tagged stack base pointer, and rewrite all
   // alloca addresses using that. Unfortunately, offsets are not known yet
   // (unless we use ASan-style mega-alloca). Instead we keep the base tag in a
@@ -748,7 +647,7 @@ bool HWAddressSanitizer::instrumentStack(
   // This generates one extra instruction per alloca use.
   for (unsigned N = 0; N < Allocas.size(); ++N) {
     auto *AI = Allocas[N];
-    IRBuilder<> IRB(AI->getNextNode());
+    IRB.SetInsertPoint(AI->getNextNode());
 
     // Replace uses of the alloca with tagged address.
     Value *Tag = getAllocaTag(IRB, StackTag, AI, N);
@@ -803,6 +702,12 @@ bool HWAddressSanitizer::runOnFunction(Function &F) {
 
   LLVM_DEBUG(dbgs() << "Function: " << F.getName() << "\n");
 
+  initializeCallbacks(*F.getParent());
+
+  assert(!LocalDynamicShadow);
+  maybeInsertDynamicShadowAtFunctionEntry(F);
+
+  bool Changed = false;
   SmallVector<Instruction*, 16> ToInstrument;
   SmallVector<AllocaInst*, 8> AllocasToInstrument;
   SmallVector<Instruction*, 8> RetVec;
@@ -835,25 +740,8 @@ bool HWAddressSanitizer::runOnFunction(Function &F) {
     }
   }
 
-  if (AllocasToInstrument.empty() && ToInstrument.empty())
-    return false;
-
-  initializeCallbacks(*F.getParent());
-
-  assert(!LocalDynamicShadow);
-
-  Instruction *InsertPt = &*F.getEntryBlock().begin();
-  IRBuilder<> EntryIRB(InsertPt);
-  LocalDynamicShadow = emitPrologue(EntryIRB,
-                                    /*WithFrameRecord*/ ClRecordStackHistory &&
-                                        !AllocasToInstrument.empty());
-
-  bool Changed = false;
-  if (!AllocasToInstrument.empty()) {
-    Value *StackTag =
-        ClGenerateTagsWithCalls ? nullptr : getStackBaseTag(EntryIRB);
-    Changed |= instrumentStack(AllocasToInstrument, RetVec, StackTag);
-  }
+  if (!AllocasToInstrument.empty())
+    Changed |= instrumentStack(AllocasToInstrument, RetVec);
 
   for (auto Inst : ToInstrument)
     Changed |= instrumentMemAccess(Inst);
@@ -864,26 +752,26 @@ bool HWAddressSanitizer::runOnFunction(Function &F) {
 }
 
 void HWAddressSanitizer::ShadowMapping::init(Triple &TargetTriple) {
+  const bool IsAndroid = TargetTriple.isAndroid();
+  const bool IsAndroidWithIfuncSupport =
+      IsAndroid && !TargetTriple.isAndroidVersionLT(21);
+
   Scale = kDefaultShadowScale;
+  const bool WithIfunc = ClWithIfunc.getNumOccurrences() > 0
+                             ? ClWithIfunc
+                             : IsAndroidWithIfuncSupport;
+
   if (ClMappingOffset.getNumOccurrences() > 0) {
     InGlobal = false;
-    InTls = false;
     Offset = ClMappingOffset;
   } else if (ClEnableKhwasan || ClInstrumentWithCalls) {
     InGlobal = false;
-    InTls = false;
     Offset = 0;
-  } else if (ClWithIfunc) {
+  } else if (WithIfunc) {
     InGlobal = true;
-    InTls = false;
-    Offset = kDynamicShadowSentinel;
-  } else if (ClWithTls) {
-    InGlobal = false;
-    InTls = true;
     Offset = kDynamicShadowSentinel;
   } else {
     InGlobal = false;
-    InTls = false;
     Offset = kDynamicShadowSentinel;
   }
 }
diff --git a/llvm/test/Instrumentation/HWAddressSanitizer/alloca.ll b/llvm/test/Instrumentation/HWAddressSanitizer/alloca.ll
index f13274171f0..011e8e4ad63 100644
--- a/llvm/test/Instrumentation/HWAddressSanitizer/alloca.ll
+++ b/llvm/test/Instrumentation/HWAddressSanitizer/alloca.ll
@@ -1,8 +1,8 @@
 ; Test alloca instrumentation.
 ;
-; RUN: opt < %s -hwasan -hwasan-with-ifunc=1 -S | FileCheck %s --check-prefixes=CHECK,DYNAMIC-SHADOW,NO-UAR-TAGS
+; RUN: opt < %s -hwasan -S | FileCheck %s --check-prefixes=CHECK,DYNAMIC-SHADOW,NO-UAR-TAGS
 ; RUN: opt < %s -hwasan -hwasan-mapping-offset=0 -S | FileCheck %s --check-prefixes=CHECK,ZERO-BASED-SHADOW,NO-UAR-TAGS
-; RUN: opt < %s -hwasan -hwasan-with-ifunc=1 -hwasan-uar-retag-to-zero=0 -S | FileCheck %s --check-prefixes=CHECK,DYNAMIC-SHADOW,UAR-TAGS
+; RUN: opt < %s -hwasan -hwasan-uar-retag-to-zero=0 -S | FileCheck %s --check-prefixes=CHECK,DYNAMIC-SHADOW,UAR-TAGS
 
 target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
 target triple = "aarch64--linux-android"
diff --git a/llvm/test/Instrumentation/HWAddressSanitizer/basic.ll b/llvm/test/Instrumentation/HWAddressSanitizer/basic.ll
index e8010992945..77d3c8cc4a6 100644
--- a/llvm/test/Instrumentation/HWAddressSanitizer/basic.ll
+++ b/llvm/test/Instrumentation/HWAddressSanitizer/basic.ll
@@ -1,7 +1,7 @@
 ; Test basic address sanitizer instrumentation.
 ;
-; RUN: opt < %s -hwasan -hwasan-recover=0 -hwasan-with-ifunc=1 -hwasan-with-tls=0 -S | FileCheck %s --check-prefixes=CHECK,ABORT,DYNAMIC-SHADOW
-; RUN: opt < %s -hwasan -hwasan-recover=1 -hwasan-with-ifunc=1 -hwasan-with-tls=0 -S | FileCheck %s --check-prefixes=CHECK,RECOVER,DYNAMIC-SHADOW
+; RUN: opt < %s -hwasan -hwasan-recover=0 -S | FileCheck %s --check-prefixes=CHECK,ABORT,DYNAMIC-SHADOW
+; RUN: opt < %s -hwasan -hwasan-recover=1 -S | FileCheck %s --check-prefixes=CHECK,RECOVER,DYNAMIC-SHADOW
 ; RUN: opt < %s -hwasan -hwasan-recover=0 -hwasan-mapping-offset=0 -S | FileCheck %s --check-prefixes=CHECK,ABORT,ZERO-BASED-SHADOW
 ; RUN: opt < %s -hwasan -hwasan-recover=1 -hwasan-mapping-offset=0 -S | FileCheck %s --check-prefixes=CHECK,RECOVER,ZERO-BASED-SHADOW
 
@@ -342,6 +342,7 @@ entry:
 define i8 @test_load_addrspace(i8 addrspace(256)* %a) sanitize_hwaddress {
 ; CHECK-LABEL: @test_load_addrspace(
 ; CHECK-NEXT: entry:
+; DYNAMIC-SHADOW: %.hwasan.shadow = call i64 asm "", "=r,0"([0 x i8]* @__hwasan_shadow)
 ; CHECK-NEXT: %[[B:[^ ]*]] = load i8, i8 addrspace(256)* %a
 ; CHECK-NEXT: ret i8 %[[B]]
 
diff --git a/llvm/test/Instrumentation/HWAddressSanitizer/prologue.ll b/llvm/test/Instrumentation/HWAddressSanitizer/prologue.ll
deleted file mode 100644
index 6b02b9863cd..00000000000
--- a/llvm/test/Instrumentation/HWAddressSanitizer/prologue.ll
+++ /dev/null
@@ -1,88 +0,0 @@
-; Test -hwasan-with-ifunc flag.
-;
-; RUN: opt -hwasan -S < %s | \
-; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-TLS,CHECK-HISTORY
-; RUN: opt -hwasan -S -hwasan-with-ifunc=0 -hwasan-with-tls=1 -hwasan-record-stack-history=1 < %s | \
-; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-TLS,CHECK-HISTORY
-; RUN: opt -hwasan -S -hwasan-with-ifunc=0 -hwasan-with-tls=1 -hwasan-record-stack-history=0 < %s | \
-; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-TLS,CHECK-NOHISTORY
-; RUN: opt -hwasan -S -hwasan-with-ifunc=0 -hwasan-with-tls=0 < %s | \
-; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-GLOBAL,CHECK-NOHISTORY
-; RUN: opt -hwasan -S -hwasan-with-ifunc=1  -hwasan-with-tls=0 < %s | \
-; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-IFUNC,CHECK-NOHISTORY
-
-target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
-target triple = "aarch64--linux-android22"
-
-; CHECK-IFUNC: @__hwasan_shadow = external global [0 x i8]
-; CHECK-NOIFUNC: @__hwasan_shadow_memory_dynamic_address = external global i64
-
-define i32 @test_load(i32* %a) sanitize_hwaddress {
-; First instrumentation in the function must be to load the dynamic shadow
-; address into a local variable.
-; CHECK-LABEL: @test_load
-; CHECK: entry:
-
-; CHECK-IFUNC:   %[[A:[^ ]*]] = call i64 asm "", "=r,0"([0 x i8]* @__hwasan_shadow)
-; CHECK-IFUNC:   add i64 %{{.*}}, %[[A]]
-
-; CHECK-GLOBAL: load i64, i64* @__hwasan_shadow_memory_dynamic_address
-
-; CHECK-TLS:   %[[A:[^ ]*]] = call i8* @llvm.thread.pointer()
-; CHECK-TLS:   %[[B:[^ ]*]] = getelementptr i8, i8* %[[A]], i32 64
-; CHECK-TLS:   %[[C:[^ ]*]] = bitcast i8* %[[B]] to i64*
-; CHECK-TLS:   %[[D:[^ ]*]] = load i64, i64* %[[C]]
-; CHECK-TLS:   %[[E:[^ ]*]] = or i64 %[[D]], 4294967295
-; CHECK-TLS:   = add i64 %[[E]], 1
-
-; "store i64" is only used to update stack history (this input IR intentionally does not use any i64)
-; W/o any allocas, the history is not updated, even if it is enabled explicitly with -hwasan-record-stack-history=1
-; CHECK-NOT: store i64
-
-; CHECK: ret i32
-
-entry:
-  %x = load i32, i32* %a, align 4
-  ret i32 %x
-}
-
-declare void @use(i32* %p)
-
-define void @test_alloca() sanitize_hwaddress {
-; First instrumentation in the function must be to load the dynamic shadow
-; address into a local variable.
-; CHECK-LABEL: @test_alloca
-; CHECK: entry:
-
-; CHECK-IFUNC:   %[[A:[^ ]*]] = call i64 asm "", "=r,0"([0 x i8]* @__hwasan_shadow)
-; CHECK-IFUNC:   add i64 %{{.*}}, %[[A]]
-
-; CHECK-GLOBAL: load i64, i64* @__hwasan_shadow_memory_dynamic_address
-
-; CHECK-TLS:   %[[A:[^ ]*]] = call i8* @llvm.thread.pointer()
-; CHECK-TLS:   %[[B:[^ ]*]] = getelementptr i8, i8* %[[A]], i32 64
-; CHECK-TLS:   %[[C:[^ ]*]] = bitcast i8* %[[B]] to i64*
-; CHECK-TLS:   %[[D:[^ ]*]] = load i64, i64* %[[C]]
-
-; CHECK-NOHISTORY-NOT: store i64
-
-; CHECK-HISTORY: %[[PTR:[^ ]*]] = inttoptr i64 %[[D]] to i64*
-; CHECK-HISTORY: store i64 %{{.*}}, i64* %[[PTR]]
-; CHECK-HISTORY: %[[D1:[^ ]*]] = ashr i64 %[[D]], 56
-; CHECK-HISTORY: %[[D2:[^ ]*]] = shl nuw nsw i64 %[[D1]], 12
-; CHECK-HISTORY: %[[D3:[^ ]*]] = xor i64 %[[D2]], -1
-; CHECK-HISTORY: %[[D4:[^ ]*]] = add i64 %[[D]], 8
-; CHECK-HISTORY: %[[D5:[^ ]*]] = and i64 %[[D4]], %[[D3]]
-; CHECK-HISTORY: store i64 %[[D5]], i64* %[[C]]
-
-; CHECK-TLS:   %[[E:[^ ]*]] = or i64 %[[D]], 4294967295
-; CHECK-TLS:   = add i64 %[[E]], 1
-
-; CHECK-NOHISTORY-NOT: store i64
-
-
-entry:
-  %x = alloca i32, align 4
-  call void @use(i32* %x)
-  ret void
-}
diff --git a/llvm/test/Instrumentation/HWAddressSanitizer/with-ifunc.ll b/llvm/test/Instrumentation/HWAddressSanitizer/with-ifunc.ll
new file mode 100644
index 00000000000..2f4abb49b29
--- /dev/null
+++ b/llvm/test/Instrumentation/HWAddressSanitizer/with-ifunc.ll
@@ -0,0 +1,30 @@
+; Test -hwasan-with-ifunc flag.
+;
+; RUN: opt -hwasan -S < %s | \
+; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-IFUNC
+; RUN: opt -hwasan -S -hwasan-with-ifunc=0 < %s | \
+; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-NOIFUNC
+; RUN: opt -hwasan -S -hwasan-with-ifunc=1 < %s | \
+; RUN:     FileCheck %s --check-prefixes=CHECK,CHECK-IFUNC
+
+target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+target triple = "aarch64--linux-android22"
+
+; CHECK-IFUNC: @__hwasan_shadow = external global [0 x i8]
+; CHECK-NOIFUNC: @__hwasan_shadow_memory_dynamic_address = external global i64
+
+define i32 @test_load(i32* %a) sanitize_hwaddress {
+; First instrumentation in the function must be to load the dynamic shadow
+; address into a local variable.
+; CHECK-LABEL: @test_load
+; CHECK: entry:
+
+; CHECK-IFUNC:   %[[A:[^ ]*]] = call i64 asm "", "=r,0"([0 x i8]* @__hwasan_shadow)
+; CHECK-IFUNC:   add i64 %{{.*}}, %[[A]]
+
+; CHECK-NOIFUNC: load i64, i64* @__hwasan_shadow_memory_dynamic_address
+
+entry:
+  %x = load i32, i32* %a, align 4
+  ret i32 %x
+}