Revert r298158.
Revert "[asan] Fix dead stripping of globals on Linux."
OOM in gold linker.
llvm-svn: 298288
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index c20ad6d..afcf865 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -101,10 +101,6 @@
"__asan_register_image_globals";
static const char *const kAsanUnregisterImageGlobalsName =
"__asan_unregister_image_globals";
-static const char *const kAsanRegisterElfGlobalsName =
- "__asan_register_elf_globals";
-static const char *const kAsanUnregisterElfGlobalsName =
- "__asan_unregister_elf_globals";
static const char *const kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
static const char *const kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
static const char *const kAsanInitName = "__asan_init";
@@ -124,11 +120,8 @@
"__asan_poison_stack_memory";
static const char *const kAsanUnpoisonStackMemoryName =
"__asan_unpoison_stack_memory";
-
-// ASan version script has __asan_* wildcard. Triple underscore prevents a
-// linker (gold) warning about attempting to export a local symbol.
static const char *const kAsanGlobalsRegisteredFlagName =
- "___asan_globals_registered";
+ "__asan_globals_registered";
static const char *const kAsanOptionDetectUseAfterReturn =
"__asan_option_detect_stack_use_after_return";
@@ -619,10 +612,6 @@
void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
ArrayRef<GlobalVariable *> ExtendedGlobals,
ArrayRef<Constant *> MetadataInitializers);
- void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
- ArrayRef<GlobalVariable *> ExtendedGlobals,
- ArrayRef<Constant *> MetadataInitializers,
- const std::string &UniqueModuleId);
void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
ArrayRef<GlobalVariable *> ExtendedGlobals,
ArrayRef<Constant *> MetadataInitializers);
@@ -633,8 +622,7 @@
GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
StringRef OriginalName);
- void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
- StringRef InternalSuffix);
+ void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata);
IRBuilder<> CreateAsanModuleDtor(Module &M);
bool ShouldInstrumentGlobal(GlobalVariable *G);
@@ -659,8 +647,6 @@
Function *AsanUnregisterGlobals;
Function *AsanRegisterImageGlobals;
Function *AsanUnregisterImageGlobals;
- Function *AsanRegisterElfGlobals;
- Function *AsanUnregisterElfGlobals;
};
// Stack poisoning does not play well with exception handling.
@@ -1610,22 +1596,12 @@
checkSanitizerInterfaceFunction(M.getOrInsertFunction(
kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy, nullptr));
AsanUnregisterImageGlobals->setLinkage(Function::ExternalLinkage);
-
- AsanRegisterElfGlobals = checkSanitizerInterfaceFunction(
- M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
- IntptrTy, IntptrTy, IntptrTy, nullptr));
- AsanRegisterElfGlobals->setLinkage(Function::ExternalLinkage);
-
- AsanUnregisterElfGlobals = checkSanitizerInterfaceFunction(
- M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
- IntptrTy, IntptrTy, IntptrTy, nullptr));
- AsanUnregisterElfGlobals->setLinkage(Function::ExternalLinkage);
}
// Put the metadata and the instrumented global in the same group. This ensures
// that the metadata is discarded if the instrumented global is discarded.
void AddressSanitizerModule::SetComdatForGlobalMetadata(
- GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
+ GlobalVariable *G, GlobalVariable *Metadata) {
Module &M = *G->getParent();
Comdat *C = G->getComdat();
if (!C) {
@@ -1635,15 +1611,7 @@
assert(G->hasLocalLinkage());
G->setName(Twine(kAsanGenPrefix) + "_anon_global");
}
-
- if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
- std::string Name = G->getName();
- Name += InternalSuffix;
- C = M.getOrInsertComdat(Name);
- } else {
- C = M.getOrInsertComdat(G->getName());
- }
-
+ C = M.getOrInsertComdat(G->getName());
// Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF.
if (TargetTriple.isOSBinFormatCOFF())
C->setSelectionKind(Comdat::NoDuplicates);
@@ -1698,69 +1666,10 @@
"global metadata will not be padded appropriately");
Metadata->setAlignment(SizeOfGlobalStruct);
- SetComdatForGlobalMetadata(G, Metadata, "");
+ SetComdatForGlobalMetadata(G, Metadata);
}
}
-void AddressSanitizerModule::InstrumentGlobalsELF(
- IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
- ArrayRef<Constant *> MetadataInitializers,
- const std::string &UniqueModuleId) {
- assert(ExtendedGlobals.size() == MetadataInitializers.size());
-
- SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
- for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
- GlobalVariable *G = ExtendedGlobals[i];
- GlobalVariable *Metadata =
- CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
- MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
- Metadata->setMetadata(LLVMContext::MD_associated, MD);
- MetadataGlobals[i] = Metadata;
-
- SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
- }
-
- // Update llvm.compiler.used, adding the new metadata globals. This is
- // needed so that during LTO these variables stay alive.
- if (!MetadataGlobals.empty())
- appendToCompilerUsed(M, MetadataGlobals);
-
- // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
- // to look up the loaded image that contains it. Second, we can store in it
- // whether registration has already occurred, to prevent duplicate
- // registration.
- //
- // Common linkage ensures that there is only one global per shared library.
- GlobalVariable *RegisteredFlag = new GlobalVariable(
- M, IntptrTy, false, GlobalVariable::CommonLinkage,
- ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
- RegisteredFlag->setVisibility(GlobalVariable::HiddenVisibility);
-
- // Create start and stop symbols.
- GlobalVariable *StartELFMetadata = new GlobalVariable(
- M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
- "__start_" + getGlobalMetadataSection());
- StartELFMetadata->setVisibility(GlobalVariable::HiddenVisibility);
- GlobalVariable *StopELFMetadata = new GlobalVariable(
- M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
- "__stop_" + getGlobalMetadataSection());
- StopELFMetadata->setVisibility(GlobalVariable::HiddenVisibility);
-
- // Create a call to register the globals with the runtime.
- IRB.CreateCall(AsanRegisterElfGlobals,
- {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
- IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
- IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
-
- // We also need to unregister globals at the end, e.g., when a shared library
- // gets closed.
- IRBuilder<> IRB_Dtor = CreateAsanModuleDtor(M);
- IRB_Dtor.CreateCall(AsanUnregisterElfGlobals,
- {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
- IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
- IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
-}
-
void AddressSanitizerModule::InstrumentGlobalsMachO(
IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
ArrayRef<Constant *> MetadataInitializers) {
@@ -2003,12 +1912,7 @@
Initializers[i] = Initializer;
}
- std::string ELFUniqueModuleId =
- TargetTriple.isOSBinFormatELF() ? getUniqueModuleId(&M) : "";
-
- if (!ELFUniqueModuleId.empty()) {
- InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
- } else if (TargetTriple.isOSBinFormatCOFF()) {
+ if (TargetTriple.isOSBinFormatCOFF()) {
InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
} else if (ShouldUseMachOGlobalsSection()) {
InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);