From a0ac3c2bf049eb28e77a19dd70cbd570585f4747 Mon Sep 17 00:00:00 2001 From: Alexey Samsonov Date: Fri, 17 Oct 2014 22:37:33 +0000 Subject: [ASan] Improve blacklisting of global variables. This commit changes the way we blacklist global variables in ASan. Now the global is excluded from instrumentation (either regular bounds checking, or initialization-order checking) if: 1) Global is explicitly blacklisted by its mangled name. This part is left unchanged. 2) SourceLocation of a global is in blacklisted source file. This changes the old behavior, where instead of looking at the SourceLocation of a variable we simply considered llvm::Module identifier. This was wrong, as identifier may not correspond to the file name, and we incorrectly disabled instrumentation for globals coming from #include'd files. 3) Global is blacklisted by type. Now we build the type of a global variable using Clang machinery (QualType::getAsString()), instead of llvm::StructType::getName(). After this commit, the active users of ASan blacklist files may have to revisit them (this is a backwards-incompatible change). llvm-svn: 220097 --- clang/lib/CodeGen/CodeGenModule.cpp | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) (limited to 'clang/lib/CodeGen/CodeGenModule.cpp') diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index c5afaa1..a9c5fb2 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -1186,6 +1186,34 @@ bool CodeGenModule::isInSanitizerBlacklist(llvm::Function *Fn, return false; } +bool CodeGenModule::isInSanitizerBlacklist(llvm::GlobalVariable *GV, + SourceLocation Loc, QualType Ty, + StringRef Category) const { + // For now globals can be blacklisted only in ASan. + if (!LangOpts.Sanitize.Address) + return false; + const auto &SanitizerBL = getContext().getSanitizerBlacklist(); + if (SanitizerBL.isBlacklistedGlobal(GV->getName(), Category)) + return true; + if (SanitizerBL.isBlacklistedLocation(Loc, Category)) + return true; + // Check global type. + if (!Ty.isNull()) { + // Drill down the array types: if global variable of a fixed type is + // blacklisted, we also don't instrument arrays of them. + while (auto AT = dyn_cast(Ty.getTypePtr())) + Ty = AT->getElementType(); + Ty = Ty.getCanonicalType().getUnqualifiedType(); + // We allow to blacklist only record types (classes, structs etc.) + if (Ty->isRecordType()) { + std::string TypeStr = Ty.getAsString(getContext().getPrintingPolicy()); + if (SanitizerBL.isBlacklistedType(TypeStr, Category)) + return true; + } + } + return false; +} + bool CodeGenModule::MayDeferGeneration(const ValueDecl *Global) { // Never defer when EmitAllDecls is specified. if (LangOpts.EmitAllDecls) @@ -2800,7 +2828,8 @@ CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S, if (Entry) *Entry = GV; - SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), ""); + SanitizerMD->reportGlobalToASan(GV, S->getStrTokenLoc(0), "", + QualType()); return GV; } -- cgit v1.1