Author: samsonov Date: Fri Jul 18 12:50:06 2014 New Revision: 213392 URL: http://llvm.org/viewvc/llvm-project?rev=213392&view=rev Log: Make sure globals created by UBSan are not instrumented by ASan.
Summary: This change adds description of globals created by UBSan instrumentation (UBSan handlers, type descriptors, filenames) to llvm.asan.globals metadata, effectively "blacklisting" them. This can dramatically decrease the data section in binaries built with UBSan+ASan, as UBSan tends to create a lot of handlers, and ASan instrumentation increases the global size to at least 64 bytes. Test Plan: clang regression test suite Reviewers: rsmith Reviewed By: rsmith Subscribers: cfe-commits, byoungyoung, kcc Differential Revision: http://reviews.llvm.org/D4575 Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp cfe/trunk/lib/CodeGen/CodeGenModule.cpp cfe/trunk/lib/CodeGen/CodeGenModule.h cfe/trunk/test/CodeGenCXX/catch-undef-behavior.cpp Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExpr.cpp?rev=213392&r1=213391&r2=213392&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CGExpr.cpp (original) +++ cfe/trunk/lib/CodeGen/CGExpr.cpp Fri Jul 18 12:50:06 2014 @@ -2127,6 +2127,7 @@ llvm::Constant *CodeGenFunction::EmitChe CGM.getModule(), Descriptor->getType(), /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor); GV->setUnnamedAddr(true); + CGM.disableSanitizerForGlobal(GV); // Remember the descriptor for this type. CGM.setTypeDescriptorInMap(T, GV); @@ -2170,14 +2171,23 @@ llvm::Value *CodeGenFunction::EmitCheckV /// \endcode /// For an invalid SourceLocation, the Filename pointer is null. llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) { + llvm::Constant *Filename; + int Line, Column; + PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc); + if (PLoc.isValid()) { + auto FilenameGV = CGM.GetAddrOfConstantCString(PLoc.getFilename(), ".src"); + CGM.disableSanitizerForGlobal(FilenameGV); + Filename = FilenameGV; + Line = PLoc.getLine(); + Column = PLoc.getColumn(); + } else { + Filename = llvm::Constant::getNullValue(Int8PtrTy); + Line = Column = 0; + } - llvm::Constant *Data[] = { - PLoc.isValid() ? CGM.GetAddrOfConstantCString(PLoc.getFilename(), ".src") - : llvm::Constant::getNullValue(Int8PtrTy), - Builder.getInt32(PLoc.isValid() ? PLoc.getLine() : 0), - Builder.getInt32(PLoc.isValid() ? PLoc.getColumn() : 0) - }; + llvm::Constant *Data[] = {Filename, Builder.getInt32(Line), + Builder.getInt32(Column)}; return llvm::ConstantStruct::getAnon(Data); } @@ -2214,6 +2224,7 @@ void CodeGenFunction::EmitCheck(llvm::Va new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false, llvm::GlobalVariable::PrivateLinkage, Info); InfoPtr->setUnnamedAddr(true); + CGM.disableSanitizerForGlobal(InfoPtr); SmallVector<llvm::Value *, 4> Args; SmallVector<llvm::Type *, 4> ArgTypes; Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=213392&r1=213391&r2=213392&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original) +++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Fri Jul 18 12:50:06 2014 @@ -1951,11 +1951,11 @@ void CodeGenModule::EmitGlobalVarDefinit void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV, SourceLocation Loc, StringRef Name, - bool IsDynInit) { + bool IsDynInit, bool IsBlacklisted) { if (!LangOpts.Sanitize.Address) return; IsDynInit &= !SanitizerBL.isIn(*GV, "init"); - bool IsBlacklisted = SanitizerBL.isIn(*GV); + IsBlacklisted |= SanitizerBL.isIn(*GV); llvm::GlobalVariable *LocDescr = nullptr; llvm::GlobalVariable *GlobalName = nullptr; @@ -2008,6 +2008,13 @@ void CodeGenModule::reportGlobalToASan(l reportGlobalToASan(GV, D.getLocation(), OS.str(), IsDynInit); } +void CodeGenModule::disableSanitizerForGlobal(llvm::GlobalVariable *GV) { + // For now, just make sure the global is not modified by the ASan + // instrumentation. + if (LangOpts.Sanitize.Address) + reportGlobalToASan(GV, SourceLocation(), "", false, true); +} + static bool isVarDeclStrongDefinition(const VarDecl *D, bool NoCommon) { // Don't give variables common linkage if -fno-common was specified unless it // was overridden by a NoCommon attribute. Modified: cfe/trunk/lib/CodeGen/CodeGenModule.h URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.h?rev=213392&r1=213391&r2=213392&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CodeGenModule.h (original) +++ cfe/trunk/lib/CodeGen/CodeGenModule.h Fri Jul 18 12:50:06 2014 @@ -1018,7 +1018,11 @@ public: void reportGlobalToASan(llvm::GlobalVariable *GV, const VarDecl &D, bool IsDynInit = false); void reportGlobalToASan(llvm::GlobalVariable *GV, SourceLocation Loc, - StringRef Name, bool IsDynInit = false); + StringRef Name, bool IsDynInit = false, + bool IsBlacklisted = false); + + /// Disable sanitizer instrumentation for this global. + void disableSanitizerForGlobal(llvm::GlobalVariable *GV); void addDeferredVTable(const CXXRecordDecl *RD) { DeferredVTables.push_back(RD); Modified: cfe/trunk/test/CodeGenCXX/catch-undef-behavior.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/catch-undef-behavior.cpp?rev=213392&r1=213391&r2=213392&view=diff ============================================================================== --- cfe/trunk/test/CodeGenCXX/catch-undef-behavior.cpp (original) +++ cfe/trunk/test/CodeGenCXX/catch-undef-behavior.cpp Fri Jul 18 12:50:06 2014 @@ -1,4 +1,5 @@ // RUN: %clang_cc1 -std=c++11 -fsanitize=signed-integer-overflow,integer-divide-by-zero,float-divide-by-zero,shift,unreachable,return,vla-bound,alignment,null,vptr,object-size,float-cast-overflow,bool,enum,array-bounds,function -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s +// RUN: %clang_cc1 -std=c++11 -fsanitize=vptr,address -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=CHECK-ASAN struct S { double d; @@ -6,6 +7,12 @@ struct S { virtual int f(); }; +// Check that type descriptor global is not modified by ASan. +// CHECK-ASAN: [[TYPE_DESCR:@[0-9]+]] = private unnamed_addr constant { i16, i16, [4 x i8] } { i16 -1, i16 0, [4 x i8] c"'S'\00" } + +// Check that type mismatch handler is not modified by ASan. +// CHECK-ASAN: private unnamed_addr global { { [{{.*}} x i8]*, i32, i32 }, { i16, i16, [4 x i8] }*, i8*, i8 } { {{.*}}, { i16, i16, [4 x i8] }* [[TYPE_DESCR]], {{.*}} } + struct T : S {}; // CHECK-LABEL: @_Z17reference_binding @@ -31,6 +38,7 @@ void reference_binding(int *p, S *q) { } // CHECK-LABEL: @_Z13member_access +// CHECK-ASAN-LABEL: @_Z13member_access void member_access(S *p) { // (1a) Check 'p' is appropriately sized and aligned for member access. _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
