hwasan: Untag unwound stack frames by wrapping personality functions.

[pcc]

Summary

One problem with untagging memory in landing pads is that it only works
correctly if the function that catches the exception is instrumented.
If the function is uninstrumented, we have no opportunity to untag the
memory.

To address this, replace landing pad instrumentation with personality function
wrapping. Each function with an instrumented stack has its personality function
replaced with a wrapper provided by the runtime. Functions that did not have
a personality function to begin with also get wrappers if they may be unwound
past. As the unwinder calls personality functions during stack unwinding,
the original personality function is called and the function's stack frame is
untagged by the wrapper if the personality function instructs the unwinder
to keep unwinding. If unwinding stops at a landing pad, the function is
still responsible for untagging its stack frame if it resumes unwinding.

The old landing pad mechanism is preserved for compatibility with old runtimes.

[pcc]

Ping.

[eugenis]

What's the binary size overhead? I assume most of it comes from adding personality functions to noexcept but !nounwind functions?

llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp

1434 ↗

(On Diff #215729)

What if the personality function is an alias or an expression that does not strip down to a function? We could still wrap it.

[pcc]

• Support aliases and other constants

[pcc]

In D66377#1642092, @eugenis wrote:

What's the binary size overhead? I assume most of it comes from adding personality functions to noexcept but !nounwind functions?

It seems to be negative overhead, at least for Android libc++.so, presumably because we're no longer instrumenting landing pads. The size of libc++.so is 1116808 bytes without this change and 1101704 bytes with the change.

llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp

1434 ↗

(On Diff #215729)

Yes we could, done.

[eugenis]

LGTM

compiler-rt/trunk/lib/hwasan/CMakeLists.txt

 include_directories(..)
 
 # Runtime library sources and build flags.
 set(HWASAN_RTL_SOURCES
   hwasan.cpp
   hwasan_allocator.cpp
   hwasan_dynamic_shadow.cpp
+  hwasan_exceptions.cpp
   hwasan_interceptors.cpp
   hwasan_interceptors_vfork.S
   hwasan_linux.cpp
   hwasan_memintrinsics.cpp
   hwasan_poisoning.cpp
   hwasan_report.cpp
   hwasan_tag_mismatch_aarch64.S
   hwasan_thread.cpp

compiler-rt/trunk/lib/hwasan/hwasan_exceptions.cpp

+//===-- hwasan_exceptions.cpp ---------------------------------------------===//
+//
+// 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 HWAddressSanitizer.
+//
+// HWAddressSanitizer runtime.
+//===----------------------------------------------------------------------===//
+
+#include "hwasan_poisoning.h"
+#include "sanitizer_common/sanitizer_common.h"
+
+#include <unwind.h>
+
+using namespace __hwasan;
+using namespace __sanitizer;
+
+typedef _Unwind_Reason_Code PersonalityFn(int version, _Unwind_Action actions,
+                                          uint64_t exception_class,
+                                          _Unwind_Exception* unwind_exception,
+                                          _Unwind_Context* context);
+
+// Pointers to the _Unwind_GetGR and _Unwind_GetCFA functions are passed in
+// instead of being called directly. This is to handle cases where the unwinder
+// is statically linked and the sanitizer runtime and the program are linked
+// against different unwinders. The _Unwind_Context data structure is opaque so
+// it may be incompatible between unwinders.
+typedef _Unwind_Word GetGRFn(_Unwind_Context* context, int index);
+typedef _Unwind_Word GetCFAFn(_Unwind_Context* context);
+
+extern "C" _Unwind_Reason_Code __hwasan_personality_wrapper(
+    int version, _Unwind_Action actions, uint64_t exception_class,
+    _Unwind_Exception* unwind_exception, _Unwind_Context* context,
+    PersonalityFn* real_personality, GetGRFn* get_gr, GetCFAFn* get_cfa) {
+  _Unwind_Reason_Code rc;
+  if (real_personality)
+    rc = real_personality(version, actions, exception_class, unwind_exception,
+                          context);
+  else
+    rc = _URC_CONTINUE_UNWIND;
+
+  // We only untag frames without a landing pad because landing pads are
+  // responsible for untagging the stack themselves if they resume.
+  //
+  // Here we assume that the frame record appears after any locals. This is not
+  // required by AAPCS but is a requirement for HWASAN instrumented functions.
+  if ((actions & _UA_CLEANUP_PHASE) && rc == _URC_CONTINUE_UNWIND) {
+#if defined(__x86_64__)
+    uptr fp = get_gr(context, 6); // rbp
+#elif defined(__aarch64__)
+    uptr fp = get_gr(context, 29); // x29
+#else
+#error Unsupported architecture
+#endif
+    uptr sp = get_cfa(context);
+    TagMemory(sp, fp - sp, 0);
+  }
+
+  return rc;
+}

compiler-rt/trunk/test/hwasan/TestCases/try-catch.cpp

 // RUN: %clangxx_hwasan %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefix=GOOD
-// RUN: %clangxx_hwasan %s -mllvm -hwasan-instrument-landing-pads=0 -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=BAD
+// RUN: %clangxx_hwasan -DNO_SANITIZE_F %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefix=GOOD
+// RUN: %clangxx_hwasan_oldrt %s -o %t && %run %t 2>&1 | FileCheck %s --check-prefix=GOOD
+// RUN: %clangxx_hwasan_oldrt %s -mllvm -hwasan-instrument-landing-pads=0 -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=BAD
 
 // C++ tests on x86_64 require instrumented libc++/libstdc++.
 // REQUIRES: aarch64-target-arch
 
 #include <stdexcept>
 #include <cstdio>
 
 static void optimization_barrier(void* arg) {

 
 __attribute__((noinline, no_sanitize("hwaddress"))) void after_catch() {
   char x[10000];
   hwasan_read(&x[0], sizeof(x));
 }
 
 
 __attribute__((noinline))
+#ifdef NO_SANITIZE_F
+__attribute__((no_sanitize("hwaddress")))
+#endif
 void f() {
   char x[1000];
   try {
     // Put two tagged frames on the stack, throw an exception from the deepest one.
     g();
   } catch (const std::runtime_error &e) {
     // Put an untagged frame on stack, check that it is indeed untagged.
     // This relies on exception support zeroing out stack tags.

compiler-rt/trunk/test/hwasan/lit.cfg.py

 # -*- Python -*-
 
 import os
 
 # Setup config name.
 config.name = 'HWAddressSanitizer' + getattr(config, 'name_suffix', 'default')
 
 # Setup source root.
 config.test_source_root = os.path.dirname(__file__)
 
 # Setup default compiler flags used with -fsanitize=memory option.
 clang_cflags = [config.target_cflags] + config.debug_info_flags
 clang_cxxflags = config.cxx_mode_flags + clang_cflags
-clang_hwasan_cflags = clang_cflags + ["-fsanitize=hwaddress", "-mllvm", "-hwasan-globals", "-fuse-ld=lld"]
+clang_hwasan_oldrt_cflags = clang_cflags + ["-fsanitize=hwaddress", "-fuse-ld=lld"]
 if config.target_arch == 'x86_64':
   # This does basically the same thing as tagged-globals on aarch64. Because
   # the x86_64 implementation is for testing purposes only there is no
   # equivalent target feature implemented on x86_64.
-  clang_hwasan_cflags += ["-mcmodel=large"]
+  clang_hwasan_oldrt_cflags += ["-mcmodel=large"]
+clang_hwasan_cflags = clang_hwasan_oldrt_cflags + ["-mllvm", "-hwasan-globals",
+                                                   "-mllvm", "-hwasan-instrument-landing-pads=0",
+                                                   "-mllvm", "-hwasan-instrument-personality-functions"]
 clang_hwasan_cxxflags = config.cxx_mode_flags + clang_hwasan_cflags
+clang_hwasan_oldrt_cxxflags = config.cxx_mode_flags + clang_hwasan_oldrt_cflags
 
 def build_invocation(compile_flags):
   return " " + " ".join([config.clang] + compile_flags) + " "
 
 config.substitutions.append( ("%clangxx ", build_invocation(clang_cxxflags)) )
 config.substitutions.append( ("%clang_hwasan ", build_invocation(clang_hwasan_cflags)) )
 config.substitutions.append( ("%clangxx_hwasan ", build_invocation(clang_hwasan_cxxflags)) )
+config.substitutions.append( ("%clangxx_hwasan_oldrt ", build_invocation(clang_hwasan_oldrt_cxxflags)) )
 config.substitutions.append( ("%compiler_rt_libdir", config.compiler_rt_libdir) )
 
 default_hwasan_opts_str = ':'.join(['disable_allocator_tagging=1', 'random_tags=0'] + config.default_sanitizer_opts)
 if default_hwasan_opts_str:
   config.environment['HWASAN_OPTIONS'] = default_hwasan_opts_str
   default_hwasan_opts_str += ':'
 config.substitutions.append(('%env_hwasan_opts=',
                              'env HWASAN_OPTIONS=' + default_hwasan_opts_str))
 
 # Default test suffixes.
 config.suffixes = ['.c', '.cpp']
 
 if config.host_os not in ['Linux', 'Android'] or not config.has_lld:
   config.unsupported = True

llvm/trunk/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp

 //===- HWAddressSanitizer.cpp - detector of uninitialized reads -------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 //
 /// \file
 /// This file is a part of HWAddressSanitizer, an address sanity checker
 /// based on tagged addressing.
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Instrumentation/HWAddressSanitizer.h"
+#include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Constant.h"

 
 using namespace llvm;
 
 #define DEBUG_TYPE "hwasan"
 
 static const char *const kHwasanModuleCtorName = "hwasan.module_ctor";
 static const char *const kHwasanNoteName = "hwasan.note";
 static const char *const kHwasanInitName = "__hwasan_init";
+static const char *const kHwasanPersonalityThunkName =
+    "__hwasan_personality_thunk";
 
 static const char *const kHwasanShadowMemoryDynamicAddress =
     "__hwasan_shadow_memory_dynamic_address";
 
 // Accesses sizes are powers of two: 1, 2, 4, 8, 16.
 static const size_t kNumberOfAccessSizes = 5;
 
 static const size_t kDefaultShadowScale = 4;
ClRecordStackHistory("hwasan-record-stack-history",
                          cl::Hidden, cl::init(true));
 static cl::opt<bool>
     ClInstrumentMemIntrinsics("hwasan-instrument-mem-intrinsics",
                               cl::desc("instrument memory intrinsics"),
                               cl::Hidden, cl::init(true));
 
 static cl::opt<bool>
     ClInstrumentLandingPads("hwasan-instrument-landing-pads",
-                              cl::desc("instrument landing pads"), cl::Hidden,
-                              cl::init(true));
+                            cl::init(false));
+
+static cl::opt<bool> ClInstrumentPersonalityFunctions(
+    "hwasan-instrument-personality-functions",
+    cl::desc("instrument personality functions"), cl::Hidden, cl::init(false));
 
 static cl::opt<bool> ClInlineAllChecks("hwasan-inline-all-checks",
                                        cl::desc("inline all checks"),
                                        cl::Hidden, cl::init(false));
 
 namespace {
 
 /// An instrumentation pass implementing detection of addressability bugs
public:
   Value *getUARTag(IRBuilder<> &IRB, Value *StackTag);
 
   Value *getHwasanThreadSlotPtr(IRBuilder<> &IRB, Type *Ty);
   void emitPrologue(IRBuilder<> &IRB, bool WithFrameRecord);
 
   void instrumentGlobal(GlobalVariable *GV, uint8_t Tag);
   void instrumentGlobals();
 
+  void instrumentPersonalityFunctions();
+
 private:
   LLVMContext *C;
   Module &M;
   Triple TargetTriple;
   FunctionCallee HWAsanMemmove, HWAsanMemcpy, HWAsanMemset;
   FunctionCallee HWAsanHandleVfork;
 
   /// This struct defines the shadow mapping using the rule:
struct ShadowMapping {
     bool InGlobal;
     bool InTls;
 
     void init(Triple &TargetTriple);
     unsigned getObjectAlignment() const { return 1U << Scale; }
   };
   ShadowMapping Mapping;
 
+  Type *VoidTy = Type::getVoidTy(M.getContext());
   Type *IntptrTy;
   Type *Int8PtrTy;
   Type *Int8Ty;
   Type *Int32Ty;
   Type *Int64Ty = Type::getInt64Ty(M.getContext());
 
   bool CompileKernel;
   bool Recover;
+  bool InstrumentLandingPads;
 
   Function *HwasanCtorFunction;
 
   FunctionCallee HwasanMemoryAccessCallback[2][kNumberOfAccessSizes];
   FunctionCallee HwasanMemoryAccessCallbackSized[2];
 
   FunctionCallee HwasanTagMemoryFunc;
   FunctionCallee HwasanGenerateTagFunc;
std::tie(HwasanCtorFunction, std::ignore) =
             // time. Hook them into the global ctors list in that case:
             [&](Function *Ctor, FunctionCallee) {
               Comdat *CtorComdat = M.getOrInsertComdat(kHwasanModuleCtorName);
               Ctor->setComdat(CtorComdat);
               appendToGlobalCtors(M, Ctor, 0, Ctor);
             });
 
     // Older versions of Android do not have the required runtime support for
-    // global instrumentation. On other platforms we currently require using the
-    // latest version of the runtime.
-    bool InstrumentGlobals =
+    // global or personality function instrumentation. On other platforms we
+    // currently require using the latest version of the runtime.
+    bool NewRuntime =
         !TargetTriple.isAndroid() || !TargetTriple.isAndroidVersionLT(30);
-    if (ClGlobals.getNumOccurrences())
-      InstrumentGlobals = ClGlobals;
+
+    bool InstrumentGlobals =
+        ClGlobals.getNumOccurrences() ? ClGlobals : NewRuntime;
     if (InstrumentGlobals)
       instrumentGlobals();
+
+    // If we don't have personality function support, fall back to landing pads.
+    InstrumentLandingPads = ClInstrumentLandingPads.getNumOccurrences()
+                                ? ClInstrumentLandingPads
+                                : !NewRuntime;
+
+    bool InstrumentPersonalityFunctions =
+        ClInstrumentPersonalityFunctions.getNumOccurrences()
+            ? ClInstrumentPersonalityFunctions
+            : NewRuntime;
+    if (InstrumentPersonalityFunctions)
+      instrumentPersonalityFunctions();
   }
 
   if (!TargetTriple.isAndroid()) {
     Constant *C = M.getOrInsertGlobal("__hwasan_tls", IntptrTy, [&] {
       auto *GV = new GlobalVariable(M, IntptrTy, /*isConstant=*/false,
                                     GlobalValue::ExternalLinkage, nullptr,
                                     "__hwasan_tls", nullptr,
                                     GlobalVariable::InitialExecTLSModel);
for (auto &Inst : BB) {
       if (isa<ReturnInst>(Inst) || isa<ResumeInst>(Inst) ||
           isa<CleanupReturnInst>(Inst))
         RetVec.push_back(&Inst);
 
       if (auto *DDI = dyn_cast<DbgDeclareInst>(&Inst))
         if (auto *Alloca = dyn_cast_or_null<AllocaInst>(DDI->getAddress()))
           AllocaDeclareMap[Alloca].push_back(DDI);
 
-      if (ClInstrumentLandingPads && isa<LandingPadInst>(Inst))
+      if (InstrumentLandingPads && isa<LandingPadInst>(Inst))
         LandingPadVec.push_back(&Inst);
 
       Value *MaybeMask = nullptr;
       bool IsWrite;
       unsigned Alignment;
       uint64_t TypeSize;
       Value *Addr = isInterestingMemoryAccess(&Inst, &IsWrite, &TypeSize,
                                               &Alignment, &MaybeMask);
       if (Addr || isa<MemIntrinsic>(Inst))
         ToInstrument.push_back(&Inst);
     }
   }
 
   initializeCallbacks(*F.getParent());
 
   if (!LandingPadVec.empty())
     instrumentLandingPads(LandingPadVec);
 
+  if (AllocasToInstrument.empty() && F.hasPersonalityFn() &&
+      F.getPersonalityFn()->getName() == kHwasanPersonalityThunkName) {
+    // __hwasan_personality_thunk is a no-op for functions without an
+    // instrumented stack, so we can drop it.
+    F.setPersonalityFn(nullptr);
+  }
+
   if (AllocasToInstrument.empty() && ToInstrument.empty())
     return false;
 
   assert(!LocalDynamicShadow);
 
   Instruction *InsertPt = &*F.getEntryBlock().begin();
   IRBuilder<> EntryIRB(InsertPt);
   emitPrologue(EntryIRB,
void HWAddressSanitizer::instrumentGlobals() {
   for (GlobalVariable *GV : Globals) {
     // Skip tag 0 in order to avoid collisions with untagged memory.
     if (Tag == 0)
       Tag = 1;
     instrumentGlobal(GV, Tag++);
   }
 }
 
+void HWAddressSanitizer::instrumentPersonalityFunctions() {
+  // We need to untag stack frames as we unwind past them. That is the job of
+  // the personality function wrapper, which either wraps an existing
+  // personality function or acts as a personality function on its own. Each
+  // function that has a personality function or that can be unwound past has
+  // its personality function changed to a thunk that calls the personality
+  // function wrapper in the runtime.
+  MapVector<Constant *, std::vector<Function *>> PersonalityFns;
+  for (Function &F : M) {
+    if (F.isDeclaration() || !F.hasFnAttribute(Attribute::SanitizeHWAddress))
+      continue;
+
+    if (F.hasPersonalityFn()) {
+      PersonalityFns[F.getPersonalityFn()->stripPointerCasts()].push_back(&F);
+    } else if (!F.hasFnAttribute(Attribute::NoUnwind)) {
+      PersonalityFns[nullptr].push_back(&F);
+    }
+  }
+
+  if (PersonalityFns.empty())
+    return;
+
+  FunctionCallee HwasanPersonalityWrapper = M.getOrInsertFunction(
+      "__hwasan_personality_wrapper", Int32Ty, Int32Ty, Int32Ty, Int64Ty,
+      Int8PtrTy, Int8PtrTy, Int8PtrTy, Int8PtrTy, Int8PtrTy);
+  FunctionCallee UnwindGetGR = M.getOrInsertFunction("_Unwind_GetGR", VoidTy);
+  FunctionCallee UnwindGetCFA = M.getOrInsertFunction("_Unwind_GetCFA", VoidTy);
+
+  for (auto &P : PersonalityFns) {
+    std::string ThunkName = kHwasanPersonalityThunkName;
+    if (P.first)
+      ThunkName += ("." + P.first->getName()).str();
+    FunctionType *ThunkFnTy = FunctionType::get(
+        Int32Ty, {Int32Ty, Int32Ty, Int64Ty, Int8PtrTy, Int8PtrTy}, false);
+    bool IsLocal = P.first && (!isa<GlobalValue>(P.first) ||
+                               cast<GlobalValue>(P.first)->hasLocalLinkage());
+    auto *ThunkFn = Function::Create(ThunkFnTy,
+                                     IsLocal ? GlobalValue::InternalLinkage
+                                             : GlobalValue::LinkOnceODRLinkage,
+                                     ThunkName, &M);
+    if (!IsLocal) {
+      ThunkFn->setVisibility(GlobalValue::HiddenVisibility);
+      ThunkFn->setComdat(M.getOrInsertComdat(ThunkName));
+    }
+
+    auto *BB = BasicBlock::Create(*C, "entry", ThunkFn);
+    IRBuilder<> IRB(BB);
+    CallInst *WrapperCall = IRB.CreateCall(
+        HwasanPersonalityWrapper,
+        {ThunkFn->getArg(0), ThunkFn->getArg(1), ThunkFn->getArg(2),
+         ThunkFn->getArg(3), ThunkFn->getArg(4),
+         P.first ? IRB.CreateBitCast(P.first, Int8PtrTy)
+                 : Constant::getNullValue(Int8PtrTy),
+         IRB.CreateBitCast(UnwindGetGR.getCallee(), Int8PtrTy),
+         IRB.CreateBitCast(UnwindGetCFA.getCallee(), Int8PtrTy)});
+    WrapperCall->setTailCall();
+    IRB.CreateRet(WrapperCall);
+
+    for (Function *F : P.second)
+      F->setPersonalityFn(ThunkFn);
+  }
+}
+
 void HWAddressSanitizer::ShadowMapping::init(Triple &TargetTriple) {
   Scale = kDefaultShadowScale;
   if (ClMappingOffset.getNumOccurrences() > 0) {
     InGlobal = false;
     InTls = false;
     Offset = ClMappingOffset;
   } else if (ClEnableKhwasan || ClInstrumentWithCalls) {
     InGlobal = false;

llvm/trunk/test/Instrumentation/HWAddressSanitizer/landingpad.ll

-; RUN: opt < %s -mtriple aarch64-linux-android -hwasan -S | FileCheck %s --check-prefixes=COMMON,ARM
-; RUN: opt < %s -mtriple x86_64-linux          -hwasan -S | FileCheck %s --check-prefixes=COMMON,X86
+; RUN: opt < %s -mtriple aarch64-linux-android29 -hwasan -S | FileCheck %s --check-prefixes=COMMON,LP,ARM
+; RUN: opt < %s -mtriple x86_64-linux -hwasan-instrument-landing-pads -hwasan -S | FileCheck %s --check-prefixes=COMMON,LP,X86
+; RUN: opt < %s -mtriple aarch64-linux-android30 -hwasan -S | FileCheck %s --check-prefixes=COMMON,NOLP
 
 target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
 target triple = "aarch64-unknown-linux-android"
 
 define i32 @f() local_unnamed_addr sanitize_hwaddress personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
 entry:
   invoke void @g()
           to label %return unwind label %lpad
 
 lpad:
   ; COMMON:       landingpad { i8*, i32 }
   ; COMMON-NEXT:    catch i8* null
   %0 = landingpad { i8*, i32 }
           catch i8* null
 
-  ; COMMON-NEXT: %[[X:[^ ]*]] = call i64 @llvm.read_register.i64(metadata ![[META:[^ ]*]])
-  ; COMMON-NEXT: call void @__hwasan_handle_vfork(i64 %[[X]])
+  ; NOLP-NOT: call void @__hwasan_handle_vfork
+  ; LP-NEXT: %[[X:[^ ]*]] = call i64 @llvm.read_register.i64(metadata ![[META:[^ ]*]])
+  ; LP-NEXT: call void @__hwasan_handle_vfork(i64 %[[X]])
 
   %1 = extractvalue { i8*, i32 } %0, 0
   %2 = tail call i8* @__cxa_begin_catch(i8* %1)
   tail call void @__cxa_end_catch()
   br label %return
 return:
   %retval.0 = phi i32 [ 1, %lpad ], [ 0, %entry ]
   ret i32 %retval.0

llvm/trunk/test/Instrumentation/HWAddressSanitizer/personality.ll

+; RUN: opt < %s -mtriple aarch64-linux-android29 -hwasan -S | FileCheck %s --check-prefix=NOPERS
+; RUN: opt < %s -mtriple aarch64-linux-android30 -hwasan -S | FileCheck %s --check-prefix=PERS
+
+; NOPERS: define void @nostack() #{{[0-9]+}} {
+; PERS: define void @nostack() #{{[0-9]+}} {
+define void @nostack() sanitize_hwaddress {
+  ret void
+}
+
+; NOPERS: define void @stack1() #{{[0-9]+}} {
+; PERS: personality {{.*}} @__hwasan_personality_thunk
+define void @stack1() sanitize_hwaddress {
+  %p = alloca i8
+  call void @sink(i8* %p)
+  ret void
+}
+
+
+; NOPERS: personality void ()* @global
+; PERS: personality {{.*}} @__hwasan_personality_thunk.global
+define void @stack2() sanitize_hwaddress personality void ()* @global {
+  %p = alloca i8
+  call void @sink(i8* %p)
+  ret void
+}
+
+define internal void @local() {
+  ret void
+}
+
+@local_alias = internal alias void (), void ()* @local
+
+; NOPERS: personality void ()* @local
+; PERS: personality {{.*}} @__hwasan_personality_thunk.local
+define void @stack3() sanitize_hwaddress personality void ()* @local {
+  %p = alloca i8
+  call void @sink(i8* %p)
+  ret void
+}
+
+; NOPERS: personality void ()* @local_alias
+; PERS: personality {{.*}} @__hwasan_personality_thunk.local_alias
+define void @stack4() sanitize_hwaddress personality void ()* @local_alias {
+  %p = alloca i8
+  call void @sink(i8* %p)
+  ret void
+}
+
+; NOPERS: personality void ()* inttoptr (i64 1 to void ()*)
+; PERS: personality i32 (i32, i32, i64, i8*, i8*)* @__hwasan_personality_thunk.
+define void @stack5() sanitize_hwaddress personality void ()* inttoptr (i64 1 to void ()*) {
+  %p = alloca i8
+  call void @sink(i8* %p)
+  ret void
+}
+
+; NOPERS: personality void ()* inttoptr (i64 2 to void ()*)
+; PERS: personality i32 (i32, i32, i64, i8*, i8*)* @__hwasan_personality_thunk..1
+define void @stack6() sanitize_hwaddress personality void ()* inttoptr (i64 2 to void ()*) {
+  %p = alloca i8
+  call void @sink(i8* %p)
+  ret void
+}
+
+declare void @global()
+declare void @sink(i8*)
+
+; PERS: define linkonce_odr hidden i32 @__hwasan_personality_thunk(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4) comdat
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4, i8* null, i8* bitcast (void ()* @_Unwind_GetGR to i8*), i8* bitcast (void ()* @_Unwind_GetCFA to i8*))
+; PERS: ret i32 %5
+
+; PERS: define linkonce_odr hidden i32 @__hwasan_personality_thunk.global(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4) comdat
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4, i8* bitcast (void ()* @global to i8*), i8* bitcast (void ()* @_Unwind_GetGR to i8*), i8* bitcast (void ()* @_Unwind_GetCFA to i8*))
+; PERS: ret i32 %5
+
+; PERS: define internal i32 @__hwasan_personality_thunk.local(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4)
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4, i8* bitcast (void ()* @local to i8*), i8* bitcast (void ()* @_Unwind_GetGR to i8*), i8* bitcast (void ()* @_Unwind_GetCFA to i8*))
+; PERS: ret i32 %5
+
+; PERS: define internal i32 @__hwasan_personality_thunk.local_alias(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4)
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4, i8* bitcast (void ()* @local_alias to i8*), i8* bitcast (void ()* @_Unwind_GetGR to i8*), i8* bitcast (void ()* @_Unwind_GetCFA to i8*))
+; PERS: ret i32 %5
+
+; PERS: define internal i32 @__hwasan_personality_thunk.(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4) {
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4, i8* inttoptr (i64 1 to i8*), i8* bitcast (void ()* @_Unwind_GetGR to i8*), i8* bitcast (void ()* @_Unwind_GetCFA to i8*))
+; PERS: ret i32 %5
+
+; PERS: define internal i32 @__hwasan_personality_thunk..1(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4) {
+; PERS: %5 = tail call i32 @__hwasan_personality_wrapper(i32 %0, i32 %1, i64 %2, i8* %3, i8* %4, i8* inttoptr (i64 2 to i8*), i8* bitcast (void ()* @_Unwind_GetGR to i8*), i8* bitcast (void ()* @_Unwind_GetCFA to i8*))
+; PERS: ret i32 %5

llvm/trunk/utils/gn/secondary/compiler-rt/lib/hwasan/BUILD.gn

source_set("sources") {
   ]
   sources = [
     "hwasan.cpp",
     "hwasan.h",
     "hwasan_allocator.cpp",
     "hwasan_allocator.h",
     "hwasan_dynamic_shadow.cpp",
     "hwasan_dynamic_shadow.h",
+    "hwasan_exceptions.cpp",
     "hwasan_flags.h",
     "hwasan_interceptors.cpp",
     "hwasan_interceptors_vfork.S",
     "hwasan_interface_internal.h",
     "hwasan_linux.cpp",
     "hwasan_malloc_bisect.h",
     "hwasan_mapping.h",
     "hwasan_memintrinsics.cpp",