[TySan] Add initial Type Sanitizer support to Clang) (llvm#76260)

This patch introduces the Clang components of type sanitizer: a
sanitizer for type-based aliasing violations.

It is based on Hal Finkel's https://reviews.llvm.org/D32198.

The Clang changes are mostly formulaic, the one specific change being
that when the TBAA sanitizer is enabled, TBAA is always generated, even
at -O0.

It goes together with the corresponding LLVM changes
(llvm#76259) and compiler-rt
changes (llvm#76261)

PR: llvm#76260

clang/docs/ReleaseNotes.rst

@@ -1176,6 +1176,10 @@ Sanitizers
   <https://clang.llvm.org/docs/SanitizerSpecialCaseList.html>`_. See that link
   for examples.
 
+- Introduced an experimental Type Sanitizer, activated by using the
+  ``-fsanitize=type`` flag. This sanitizer detects violations of C/C++ type-based
+  aliasing rules.
+
 Python Binding Changes
 ----------------------
 - Fixed an issue that led to crashes when calling ``Type.get_exception_specification_kind``.

clang/include/clang/Basic/Features.def

@@ -102,6 +102,7 @@ FEATURE(numerical_stability_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Nume
 FEATURE(memory_sanitizer,
         LangOpts.Sanitize.hasOneOf(SanitizerKind::Memory |
                                    SanitizerKind::KernelMemory))
+FEATURE(type_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Type))
 FEATURE(thread_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Thread))
 FEATURE(dataflow_sanitizer, LangOpts.Sanitize.has(SanitizerKind::DataFlow))
 FEATURE(scudo, LangOpts.Sanitize.hasOneOf(SanitizerKind::Scudo))

clang/include/clang/Basic/Sanitizers.def

@@ -73,6 +73,9 @@ SANITIZER("fuzzer", Fuzzer)
 // libFuzzer-required instrumentation, no linking.
 SANITIZER("fuzzer-no-link", FuzzerNoLink)
 
+// TypeSanitizer
+SANITIZER("type", Type)
+
 // ThreadSanitizer
 SANITIZER("thread", Thread)
 

clang/include/clang/Driver/SanitizerArgs.h

@@ -87,6 +87,7 @@ class SanitizerArgs {
   bool needsHwasanAliasesRt() const {
     return needsHwasanRt() && HwasanUseAliases;
   }
+  bool needsTysanRt() const { return Sanitizers.has(SanitizerKind::Type); }
   bool needsTsanRt() const { return Sanitizers.has(SanitizerKind::Thread); }
   bool needsMsanRt() const { return Sanitizers.has(SanitizerKind::Memory); }
   bool needsFuzzer() const { return Sanitizers.has(SanitizerKind::Fuzzer); }

clang/lib/CodeGen/BackendUtil.cpp

@@ -77,6 +77,7 @@
 #include "llvm/Transforms/Instrumentation/SanitizerBinaryMetadata.h"
 #include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
 #include "llvm/Transforms/Instrumentation/ThreadSanitizer.h"
+#include "llvm/Transforms/Instrumentation/TypeSanitizer.h"
 #include "llvm/Transforms/ObjCARC.h"
 #include "llvm/Transforms/Scalar/EarlyCSE.h"
 #include "llvm/Transforms/Scalar/GVN.h"
@@ -735,6 +736,11 @@ static void addSanitizers(const Triple &TargetTriple,
       MPM.addPass(createModuleToFunctionPassAdaptor(ThreadSanitizerPass()));
     }
 
+    if (LangOpts.Sanitize.has(SanitizerKind::Type)) {
+      MPM.addPass(ModuleTypeSanitizerPass());
+      MPM.addPass(createModuleToFunctionPassAdaptor(TypeSanitizerPass()));
+    }
+
     if (LangOpts.Sanitize.has(SanitizerKind::NumericalStability))
       MPM.addPass(NumericalStabilitySanitizerPass());
 

clang/lib/CodeGen/CGDeclCXX.cpp

@@ -479,6 +479,10 @@ llvm::Function *CodeGenModule::CreateGlobalInitOrCleanUpFunction(
       !isInNoSanitizeList(SanitizerKind::MemtagStack, Fn, Loc))
     Fn->addFnAttr(llvm::Attribute::SanitizeMemTag);
 
+  if (getLangOpts().Sanitize.has(SanitizerKind::Type) &&
+      !isInNoSanitizeList(SanitizerKind::Type, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeType);
+
   if (getLangOpts().Sanitize.has(SanitizerKind::Thread) &&
       !isInNoSanitizeList(SanitizerKind::Thread, Fn, Loc))
     Fn->addFnAttr(llvm::Attribute::SanitizeThread);

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -837,6 +837,8 @@ void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy,
       Fn->addFnAttr(llvm::Attribute::SanitizeMemTag);
     if (SanOpts.has(SanitizerKind::Thread))
       Fn->addFnAttr(llvm::Attribute::SanitizeThread);
+    if (SanOpts.has(SanitizerKind::Type))
+      Fn->addFnAttr(llvm::Attribute::SanitizeType);
     if (SanOpts.has(SanitizerKind::NumericalStability))
       Fn->addFnAttr(llvm::Attribute::SanitizeNumericalStability);
     if (SanOpts.hasOneOf(SanitizerKind::Memory | SanitizerKind::KernelMemory))

clang/lib/CodeGen/CodeGenModule.cpp

@@ -397,8 +397,8 @@ CodeGenModule::CodeGenModule(ASTContext &C,
   if (LangOpts.HLSL)
     createHLSLRuntime();
 
-  // Enable TBAA unless it's suppressed. ThreadSanitizer needs TBAA even at O0.
-  if (LangOpts.Sanitize.has(SanitizerKind::Thread) ||
+  // Enable TBAA unless it's suppressed. TSan and TySan need TBAA even at O0.
+  if (LangOpts.Sanitize.hasOneOf(SanitizerKind::Thread | SanitizerKind::Type) ||
       (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0))
     TBAA.reset(new CodeGenTBAA(Context, getTypes(), TheModule, CodeGenOpts,
                                getLangOpts()));

clang/lib/CodeGen/CodeGenTBAA.cpp

@@ -314,8 +314,10 @@ llvm::MDNode *CodeGenTBAA::getTypeInfoHelper(const Type *Ty) {
 }
 
 llvm::MDNode *CodeGenTBAA::getTypeInfo(QualType QTy) {
-  // At -O0 or relaxed aliasing, TBAA is not emitted for regular types.
-  if (CodeGenOpts.OptimizationLevel == 0 || CodeGenOpts.RelaxedAliasing)
+  // At -O0 or relaxed aliasing, TBAA is not emitted for regular types (unless
+  // we're running TypeSanitizer).
+  if (!Features.Sanitize.has(SanitizerKind::Type) &&
+      (CodeGenOpts.OptimizationLevel == 0 || CodeGenOpts.RelaxedAliasing))
     return nullptr;
 
   // If the type has the may_alias attribute (even on a typedef), it is

clang/lib/CodeGen/SanitizerMetadata.cpp

@@ -19,9 +19,10 @@ using namespace CodeGen;
 
 SanitizerMetadata::SanitizerMetadata(CodeGenModule &CGM) : CGM(CGM) {}
 
-static bool isAsanHwasanOrMemTag(const SanitizerSet &SS) {
+static bool isAsanHwasanMemTagOrTysan(const SanitizerSet &SS) {
   return SS.hasOneOf(SanitizerKind::Address | SanitizerKind::KernelAddress |
-                     SanitizerKind::HWAddress | SanitizerKind::MemTag);
+                     SanitizerKind::HWAddress | SanitizerKind::MemTag |
+                     SanitizerKind::Type);
 }
 
 static SanitizerMask expandKernelSanitizerMasks(SanitizerMask Mask) {
@@ -68,7 +69,7 @@ void SanitizerMetadata::reportGlobal(llvm::GlobalVariable *GV,
                                      SanitizerMask NoSanitizeAttrMask,
                                      bool IsDynInit) {
   SanitizerSet FsanitizeArgument = CGM.getLangOpts().Sanitize;
-  if (!isAsanHwasanOrMemTag(FsanitizeArgument))
+  if (!isAsanHwasanMemTagOrTysan(FsanitizeArgument))
     return;
 
   FsanitizeArgument.Mask = expandKernelSanitizerMasks(FsanitizeArgument.Mask);
@@ -105,11 +106,32 @@ void SanitizerMetadata::reportGlobal(llvm::GlobalVariable *GV,
                                            GV, Loc, Ty, "init");
 
   GV->setSanitizerMetadata(Meta);
+
+  if (Ty.isNull() || !CGM.getLangOpts().Sanitize.has(SanitizerKind::Type) ||
+      NoSanitizeAttrMask & SanitizerKind::Type)
+    return;
+
+  llvm::MDNode *TBAAInfo = CGM.getTBAATypeInfo(Ty);
+  if (!TBAAInfo || TBAAInfo == CGM.getTBAATypeInfo(CGM.getContext().CharTy))
+    return;
+
+  llvm::Metadata *GlobalMetadata[] = {llvm::ConstantAsMetadata::get(GV),
+                                      TBAAInfo};
+
+  // Metadata for the global already registered.
+  if (llvm::MDNode::getIfExists(CGM.getLLVMContext(), GlobalMetadata))
+    return;
+
+  llvm::MDNode *ThisGlobal =
+      llvm::MDNode::get(CGM.getLLVMContext(), GlobalMetadata);
+  llvm::NamedMDNode *TysanGlobals =
+      CGM.getModule().getOrInsertNamedMetadata("llvm.tysan.globals");
+  TysanGlobals->addOperand(ThisGlobal);
 }
 
 void SanitizerMetadata::reportGlobal(llvm::GlobalVariable *GV, const VarDecl &D,
                                      bool IsDynInit) {
-  if (!isAsanHwasanOrMemTag(CGM.getLangOpts().Sanitize))
+  if (!isAsanHwasanMemTagOrTysan(CGM.getLangOpts().Sanitize))
     return;
   std::string QualName;
   llvm::raw_string_ostream OS(QualName);

clang/lib/Driver/SanitizerArgs.cpp

@@ -37,15 +37,15 @@ static const SanitizerMask NotAllowedWithMinimalRuntime = SanitizerKind::Vptr;
 static const SanitizerMask NotAllowedWithExecuteOnly =
     SanitizerKind::Function | SanitizerKind::KCFI;
 static const SanitizerMask NeedsUnwindTables =
-    SanitizerKind::Address | SanitizerKind::HWAddress | SanitizerKind::Thread |
-    SanitizerKind::Memory | SanitizerKind::DataFlow |
+    SanitizerKind::Address | SanitizerKind::HWAddress | SanitizerKind::Type |
+    SanitizerKind::Thread | SanitizerKind::Memory | SanitizerKind::DataFlow |
     SanitizerKind::NumericalStability;
 static const SanitizerMask SupportsCoverage =
     SanitizerKind::Address | SanitizerKind::HWAddress |
     SanitizerKind::KernelAddress | SanitizerKind::KernelHWAddress |
-    SanitizerKind::MemtagStack | SanitizerKind::MemtagHeap |
-    SanitizerKind::MemtagGlobals | SanitizerKind::Memory |
-    SanitizerKind::KernelMemory | SanitizerKind::Leak |
+    SanitizerKind::Type | SanitizerKind::MemtagStack |
+    SanitizerKind::MemtagHeap | SanitizerKind::MemtagGlobals |
+    SanitizerKind::Memory | SanitizerKind::KernelMemory | SanitizerKind::Leak |
     SanitizerKind::Undefined | SanitizerKind::Integer | SanitizerKind::Bounds |
     SanitizerKind::ImplicitConversion | SanitizerKind::Nullability |
     SanitizerKind::DataFlow | SanitizerKind::Fuzzer |
@@ -182,6 +182,7 @@ static void addDefaultIgnorelists(const Driver &D, SanitizerMask Kinds,
                      {"msan_ignorelist.txt", SanitizerKind::Memory},
                      {"nsan_ignorelist.txt", SanitizerKind::NumericalStability},
                      {"tsan_ignorelist.txt", SanitizerKind::Thread},
+                     {"tysan_blacklist.txt", SanitizerKind::Type},
                      {"dfsan_abilist.txt", SanitizerKind::DataFlow},
                      {"cfi_ignorelist.txt", SanitizerKind::CFI},
                      {"ubsan_ignorelist.txt",
@@ -542,6 +543,10 @@ SanitizerArgs::SanitizerArgs(const ToolChain &TC,
   std::pair<SanitizerMask, SanitizerMask> IncompatibleGroups[] = {
       std::make_pair(SanitizerKind::Address,
                      SanitizerKind::Thread | SanitizerKind::Memory),
+      std::make_pair(SanitizerKind::Type,
+                     SanitizerKind::Address | SanitizerKind::KernelAddress |
+                         SanitizerKind::Memory | SanitizerKind::Leak |
+                         SanitizerKind::Thread | SanitizerKind::KernelAddress),
       std::make_pair(SanitizerKind::Thread, SanitizerKind::Memory),
       std::make_pair(SanitizerKind::Leak,
                      SanitizerKind::Thread | SanitizerKind::Memory),

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -1480,6 +1480,8 @@ collectSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
     }
     if (SanArgs.needsTsanRt())
       SharedRuntimes.push_back("tsan");
+    if (SanArgs.needsTysanRt())
+      SharedRuntimes.push_back("tysan");
     if (SanArgs.needsHwasanRt()) {
       if (SanArgs.needsHwasanAliasesRt())
         SharedRuntimes.push_back("hwasan_aliases");
@@ -1552,6 +1554,8 @@ collectSanitizerRuntimes(const ToolChain &TC, const ArgList &Args,
     if (SanArgs.linkCXXRuntimes())
       StaticRuntimes.push_back("tsan_cxx");
   }
+  if (!SanArgs.needsSharedRt() && SanArgs.needsTysanRt())
+    StaticRuntimes.push_back("tysan");
   if (!SanArgs.needsSharedRt() && SanArgs.needsUbsanRt()) {
     if (SanArgs.requiresMinimalRuntime()) {
       StaticRuntimes.push_back("ubsan_minimal");

clang/lib/Driver/ToolChains/Darwin.cpp

@@ -1600,6 +1600,8 @@ void DarwinClang::AddLinkRuntimeLibArgs(const ArgList &Args,
              "Static sanitizer runtimes not supported");
       AddLinkSanitizerLibArgs(Args, CmdArgs, "tsan");
     }
+    if (Sanitize.needsTysanRt())
+      AddLinkSanitizerLibArgs(Args, CmdArgs, "tysan");
     if (Sanitize.needsFuzzer() && !Args.hasArg(options::OPT_dynamiclib)) {
       AddLinkSanitizerLibArgs(Args, CmdArgs, "fuzzer", /*shared=*/false);
 
@@ -3603,6 +3605,10 @@ SanitizerMask Darwin::getSupportedSanitizers() const {
     Res |= SanitizerKind::Thread;
   }
 
+  if ((IsX86_64 || IsAArch64) && isTargetMacOSBased()) {
+    Res |= SanitizerKind::Type;
+  }
+
   if (IsX86_64)
     Res |= SanitizerKind::NumericalStability;
 

clang/lib/Driver/ToolChains/Linux.cpp

@@ -837,6 +837,8 @@ SanitizerMask Linux::getSupportedSanitizers() const {
   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsPowerPC64 || IsSystemZ ||
       IsLoongArch64 || IsRISCV64)
     Res |= SanitizerKind::Thread;
+  if (IsX86_64 || IsAArch64)
+    Res |= SanitizerKind::Type;
   if (IsX86_64 || IsSystemZ || IsPowerPC64)
     Res |= SanitizerKind::KernelMemory;
   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsX86 || IsMIPS || IsArmArch ||

clang/test/CodeGen/sanitize-type-attr.cpp

@@ -0,0 +1,85 @@
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s | FileCheck -check-prefix=WITHOUT %s
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s -fsanitize=type | FileCheck -check-prefix=TYSAN %s
+// RUN: echo "src:%s" | sed -e 's/\\/\\\\/g' > %t
+// RUN: %clang_cc1 -triple x86_64-linux-gnu -emit-llvm -o - %s -fsanitize=type -fsanitize-blacklist=%t | FileCheck -check-prefix=BL %s
+
+// The sanitize_type attribute should be attached to functions
+// when TypeSanitizer is enabled, unless no_sanitize("type") attribute
+// is present.
+
+// WITHOUT:  NoTYSAN1{{.*}}) [[NOATTR:#[0-9]+]]
+// BL:  NoTYSAN1{{.*}}) [[NOATTR:#[0-9]+]]
+// TYSAN:  NoTYSAN1{{.*}}) [[NOATTR:#[0-9]+]]
+__attribute__((no_sanitize("type"))) int NoTYSAN1(int *a) { return *a; }
+
+// WITHOUT:  NoTYSAN2{{.*}}) [[NOATTR]]
+// BL:  NoTYSAN2{{.*}}) [[NOATTR]]
+// TYSAN:  NoTYSAN2{{.*}}) [[NOATTR]]
+__attribute__((no_sanitize("type"))) int NoTYSAN2(int *a);
+int NoTYSAN2(int *a) { return *a; }
+
+// WITHOUT:  NoTYSAN3{{.*}}) [[NOATTR:#[0-9]+]]
+// BL:  NoTYSAN3{{.*}}) [[NOATTR:#[0-9]+]]
+// TYSAN:  NoTYSAN3{{.*}}) [[NOATTR:#[0-9]+]]
+__attribute__((no_sanitize("type"))) int NoTYSAN3(int *a) { return *a; }
+
+// WITHOUT:  TYSANOk{{.*}}) [[NOATTR]]
+// BL:  TYSANOk{{.*}}) [[NOATTR]]
+// TYSAN: TYSANOk{{.*}}) [[WITH:#[0-9]+]]
+int TYSANOk(int *a) { return *a; }
+
+// WITHOUT:  TemplateTYSANOk{{.*}}) [[NOATTR]]
+// BL:  TemplateTYSANOk{{.*}}) [[NOATTR]]
+// TYSAN: TemplateTYSANOk{{.*}}) [[WITH]]
+template <int i>
+int TemplateTYSANOk() { return i; }
+
+// WITHOUT:  TemplateNoTYSAN{{.*}}) [[NOATTR]]
+// BL:  TemplateNoTYSAN{{.*}}) [[NOATTR]]
+// TYSAN: TemplateNoTYSAN{{.*}}) [[NOATTR]]
+template <int i>
+__attribute__((no_sanitize("type"))) int TemplateNoTYSAN() { return i; }
+
+int force_instance = TemplateTYSANOk<42>() + TemplateNoTYSAN<42>();
+
+// Check that __cxx_global_var_init* get the sanitize_type attribute.
+int global1 = 0;
+int global2 = *(int *)((char *)&global1 + 1);
+// WITHOUT: @__cxx_global_var_init{{.*}}[[NOATTR:#[0-9]+]]
+// BL: @__cxx_global_var_init{{.*}}[[NOATTR:#[0-9]+]]
+// TYSAN: @__cxx_global_var_init{{.*}}[[WITH:#[0-9]+]]
+
+// Make sure that we don't add globals to the list for which we don't have a
+// specific type description.
+// FIXME: We now have a type description for this type and a global is added. Should it?
+struct SX {
+  int a, b;
+};
+SX sx;
+
+void consumer(const char *);
+
+void char_caller() {
+  // TYSAN: void @_Z11char_callerv()
+  // TYSAN-NEXT: entry:
+  // TYSAN-NEXT: call void @_Z8consumerPKc(ptr noundef @.str)
+  // TYSAN-NEXT: ret void
+
+  consumer("foo");
+}
+
+// WITHOUT: attributes [[NOATTR]] = { noinline nounwind{{.*}} }
+
+// BL: attributes [[NOATTR]] = { noinline nounwind{{.*}} }
+
+// TYSAN: attributes [[NOATTR]] = { mustprogress noinline nounwind{{.*}} }
+// TYSAN: attributes [[WITH]] = { noinline nounwind sanitize_type{{.*}} }
+
+// TYSAN-DAG: !llvm.tysan.globals = !{[[G1MD:![0-9]+]], [[G2MD:![0-9]+]], [[G3MD:![0-9]+]], [[SXMD:![0-9]+]]}
+// TYSAN-DAG: [[G1MD]] = !{ptr @force_instance, [[INTMD:![0-9]+]]}
+// TYSAN-DAG: [[INTMD]] = !{!"int",
+// TYSAN-DAG: [[G2MD]] = !{ptr @global1, [[INTMD]]}
+// TYSAN-DAG: [[G3MD]] = !{ptr @global2, [[INTMD]]}
+// TYSAN-DAG: [[SXMD]] = !{ptr @sx, [[SXTYMD:![0-9]+]]}
+// TYSAN-DAG: [[SXTYMD]] = !{!"_ZTS2SX", [[INTMD]], i64 0, !1, i64 4}
+// TYSAN-DAG: Simple C++ TBAA

clang/test/Driver/sanitizer-ld.c

@@ -274,6 +274,29 @@
 // CHECK-ASAN-ANDROID-SHARED-NOT: "-lpthread"
 // CHECK-ASAN-ANDROID-SHARED-NOT: "-lresolv"
 
+
+// RUN: %clangxx %s -### -o %t.o 2>&1 \
+// RUN:     --target=x86_64-unknown-linux -fuse-ld=ld -stdlib=platform -lstdc++ \
+// RUN:     -fsanitize=type \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-TYSAN-LINUX-CXX %s
+//
+// CHECK-TYSAN-LINUX-CXX: "{{(.*[^-.0-9A-Z_a-z])?}}ld{{(.exe)?}}"
+// CHECK-TYSAN-LINUX-CXX-NOT: stdc++
+// CHECK-TYSAN-LINUX-CXX: "--whole-archive" "{{.*}}libclang_rt.tysan{{[^.]*}}.a" "--no-whole-archive"
+// CHECK-TYSAN-LINUX-CXX: stdc++
+
+// RUN: %clangxx -fsanitize=type -### %s 2>&1 \
+// RUN:     -mmacosx-version-min=10.6 \
+// RUN:     --target=x86_64-apple-darwin13.4.0 -fuse-ld=ld -stdlib=platform \
+// RUN:     -resource-dir=%S/Inputs/resource_dir \
+// RUN:     --sysroot=%S/Inputs/basic_linux_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-TYSAN-DARWIN-CXX %s
+// CHECK-TYSAN-DARWIN-CXX: "{{.*}}ld{{(.exe)?}}"
+// CHECK-TYSAN-DARWIN-CXX: libclang_rt.tysan_osx_dynamic.dylib
+// CHECK-TYSAN-DARWIN-CXX-NOT: -lc++abi
+
 // RUN: %clangxx -### %s 2>&1 \
 // RUN:     --target=x86_64-unknown-linux -fuse-ld=ld -stdlib=platform -lstdc++ \
 // RUN:     -fsanitize=thread \