From: Alexey Samsonov Date: Sat, 12 Jul 2014 00:42:52 +0000 (+0000) Subject: [ASan] Collect unmangled names of global variables in Clang to print them in error... X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a9b243cdf1b4b0adfb6a74e8c96638138634e979;p=clang [ASan] Collect unmangled names of global variables in Clang to print them in error reports. Currently ASan instrumentation pass creates a string with global name for each instrumented global (to include global names in the error report). Global name is already mangled at this point, and we may not be able to demangle it at runtime (e.g. there is no __cxa_demangle on Android). Instead, create a string with fully qualified global name in Clang, and pass it to ASan instrumentation pass in llvm.asan.globals metadata. If there is no metadata for some global, ASan will use the original algorithm. This fixes https://code.google.com/p/address-sanitizer/issues/detail?id=264. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@212872 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp index 9bd61d7164..91f8041930 100644 --- a/lib/CodeGen/CGDecl.cpp +++ b/lib/CodeGen/CGDecl.cpp @@ -345,7 +345,7 @@ void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D, DMEntry = castedAddr; CGM.setStaticLocalDeclAddress(&D, castedAddr); - CGM.reportGlobalToASan(var, D.getLocation()); + CGM.reportGlobalToASan(var, D); // Emit global variable debug descriptor for static vars. CGDebugInfo *DI = getDebugInfo(); diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp index 2f87392c36..66ac524f2b 100644 --- a/lib/CodeGen/CodeGenModule.cpp +++ b/lib/CodeGen/CodeGenModule.cpp @@ -1952,7 +1952,7 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { if (NeedsGlobalCtor || NeedsGlobalDtor) EmitCXXGlobalVarDeclInitFunc(D, GV, NeedsGlobalCtor); - reportGlobalToASan(GV, D->getLocation(), NeedsGlobalCtor); + reportGlobalToASan(GV, *D, NeedsGlobalCtor); // Emit global variable debug information. if (CGDebugInfo *DI = getModuleDebugInfo()) @@ -1961,24 +1961,25 @@ void CodeGenModule::EmitGlobalVarDefinition(const VarDecl *D) { } void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV, - SourceLocation Loc, bool IsDynInit) { + SourceLocation Loc, StringRef Name, + bool IsDynInit) { if (!LangOpts.Sanitize.Address) return; IsDynInit &= !SanitizerBL.isIn(*GV, "init"); bool IsBlacklisted = SanitizerBL.isIn(*GV); - llvm::LLVMContext &LLVMCtx = TheModule.getContext(); - llvm::GlobalVariable *LocDescr = nullptr; + llvm::GlobalVariable *GlobalName = nullptr; if (!IsBlacklisted) { - // Don't generate source location if a global is blacklisted - it won't - // be instrumented anyway. + // Don't generate source location and global name if it is blacklisted - + // it won't be instrumented anyway. PresumedLoc PLoc = Context.getSourceManager().getPresumedLoc(Loc); if (PLoc.isValid()) { llvm::Constant *LocData[] = { GetAddrOfConstantCString(PLoc.getFilename()), - llvm::ConstantInt::get(llvm::Type::getInt32Ty(LLVMCtx), PLoc.getLine()), - llvm::ConstantInt::get(llvm::Type::getInt32Ty(LLVMCtx), + llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), + PLoc.getLine()), + llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), PLoc.getColumn()), }; auto LocStruct = llvm::ConstantStruct::getAnon(LocData); @@ -1990,14 +1991,17 @@ void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV, // the optimizer before the ASan instrumentation pass. addCompilerUsedGlobal(LocDescr); } + if (!Name.empty()) { + GlobalName = GetAddrOfConstantCString(Name); + // GlobalName shouldn't be removed by the optimizer. + addCompilerUsedGlobal(GlobalName); + } } llvm::Value *GlobalMetadata[] = { - GV, - LocDescr, - llvm::ConstantInt::get(llvm::Type::getInt1Ty(LLVMCtx), IsDynInit), - llvm::ConstantInt::get(llvm::Type::getInt1Ty(LLVMCtx), IsBlacklisted) - }; + GV, LocDescr, GlobalName, + llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsDynInit), + llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext), IsBlacklisted)}; llvm::MDNode *ThisGlobal = llvm::MDNode::get(VMContext, GlobalMetadata); llvm::NamedMDNode *AsanGlobals = @@ -2005,6 +2009,16 @@ void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV, AsanGlobals->addOperand(ThisGlobal); } +void CodeGenModule::reportGlobalToASan(llvm::GlobalVariable *GV, + const VarDecl &D, bool IsDynInit) { + if (!LangOpts.Sanitize.Address) + return; + std::string QualName; + llvm::raw_string_ostream OS(QualName); + D.printQualifiedName(OS); + reportGlobalToASan(GV, D.getLocation(), OS.str(), IsDynInit); +} + 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. @@ -2810,7 +2824,7 @@ CodeGenModule::GetAddrOfConstantStringFromLiteral(const StringLiteral *S) { if (Entry) Entry->setValue(GV); - reportGlobalToASan(GV, S->getStrTokenLoc(0)); + reportGlobalToASan(GV, S->getStrTokenLoc(0), ""); return GV; } diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h index 3425469746..d6b694a882 100644 --- a/lib/CodeGen/CodeGenModule.h +++ b/lib/CodeGen/CodeGenModule.h @@ -1015,8 +1015,10 @@ public: return SanitizerBL; } - void reportGlobalToASan(llvm::GlobalVariable *GV, SourceLocation Loc, + void reportGlobalToASan(llvm::GlobalVariable *GV, const VarDecl &D, bool IsDynInit = false); + void reportGlobalToASan(llvm::GlobalVariable *GV, SourceLocation Loc, + StringRef Name, bool IsDynInit = false); void addDeferredVTable(const CXXRecordDecl *RD) { DeferredVTables.push_back(RD); diff --git a/test/CodeGen/asan-globals.cpp b/test/CodeGen/asan-globals.cpp index 2702f1d450..d9ecc64615 100644 --- a/test/CodeGen/asan-globals.cpp +++ b/test/CodeGen/asan-globals.cpp @@ -6,27 +6,31 @@ int global; // CHECK: [[GLOBAL_LOC:@.asan_loc_descr[0-9]*]] = private unnamed_addr constant {{.*}} i32 [[@LINE-1]], i32 5 +// CHECK: [[GLOBAL_NAME:@.str[0-9]+]] = private unnamed_addr constant {{.*}} c"global\00" int dyn_init_global = global; // CHECK: [[DYN_INIT_LOC:@.asan_loc_descr[0-9]*]] = {{.*}} i32 [[@LINE-1]], i32 5 +// CHECK: [[DYN_INIT_NAME:@.str[0-9]+]] = private unnamed_addr constant {{.*}} c"dyn_init_global\00" int blacklisted_global; void func() { static int static_var = 0; // CHECK: [[STATIC_LOC:@.asan_loc_descr[0-9]*]] = {{.*}} i32 [[@LINE-1]], i32 14 + // CHECK: [[STATIC_NAME:@.str[0-9]+]] = private unnamed_addr constant {{.*}} c"static_var\00" const char *literal = "Hello, world!"; // CHECK: [[LITERAL_LOC:@.asan_loc_descr[0-9]*]] = {{.*}} i32 [[@LINE-1]], i32 25 + // CHECK: [[LITERAL_NAME:@.str[0-9]+]] = private unnamed_addr constant {{.*}} c"\00" } // CHECK: !llvm.asan.globals = !{![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]} -// CHECK: ![[GLOBAL]] = metadata !{{{.*}} [[GLOBAL_LOC]], i1 false, i1 false} -// CHECK: ![[DYN_INIT_GLOBAL]] = metadata !{{{.*}} [[DYN_INIT_LOC]], i1 true, i1 false} -// CHECK: ![[BLACKLISTED_GLOBAL]] = metadata !{{{.*}}, null, i1 false, i1 true} -// CHECK: ![[STATIC_VAR]] = metadata !{{{.*}} [[STATIC_LOC]], i1 false, i1 false} -// CHECK: ![[LITERAL]] = metadata !{{{.*}} [[LITERAL_LOC]], i1 false, i1 false} +// CHECK: ![[GLOBAL]] = metadata !{{{.*}} [[GLOBAL_LOC]], {{.*}} [[GLOBAL_NAME]], i1 false, i1 false} +// CHECK: ![[DYN_INIT_GLOBAL]] = metadata !{{{.*}} [[DYN_INIT_LOC]], {{.*}} [[DYN_INIT_NAME]], i1 true, i1 false} +// CHECK: ![[BLACKLISTED_GLOBAL]] = metadata !{{{.*}}, null, null, i1 false, i1 true} +// CHECK: ![[STATIC_VAR]] = metadata !{{{.*}} [[STATIC_LOC]], {{.*}} [[STATIC_NAME]], i1 false, i1 false} +// CHECK: ![[LITERAL]] = metadata !{{{.*}} [[LITERAL_LOC]], {{.*}} [[LITERAL_NAME]], i1 false, i1 false} // BLACKLIST-SRC: !llvm.asan.globals = !{![[GLOBAL:[0-9]+]], ![[DYN_INIT_GLOBAL:[0-9]+]], ![[BLACKLISTED_GLOBAL:[0-9]+]], ![[STATIC_VAR:[0-9]+]], ![[LITERAL:[0-9]+]]} -// BLACKLIST-SRC: ![[GLOBAL]] = metadata !{{{.*}} null, i1 false, i1 true} -// BLACKLIST-SRC: ![[DYN_INIT_GLOBAL]] = metadata !{{{.*}} null, i1 true, i1 true} -// BLACKLIST-SRC: ![[BLACKLISTED_GLOBAL]] = metadata !{{{.*}}, null, i1 false, i1 true} -// BLACKLIST-SRC: ![[STATIC_VAR]] = metadata !{{{.*}} null, i1 false, i1 true} -// BLACKLIST-SRC: ![[LITERAL]] = metadata !{{{.*}} null, i1 false, i1 true} +// BLACKLIST-SRC: ![[GLOBAL]] = metadata !{{{.*}} null, null, i1 false, i1 true} +// BLACKLIST-SRC: ![[DYN_INIT_GLOBAL]] = metadata !{{{.*}} null, null, i1 true, i1 true} +// BLACKLIST-SRC: ![[BLACKLISTED_GLOBAL]] = metadata !{{{.*}}, null, null, i1 false, i1 true} +// BLACKLIST-SRC: ![[STATIC_VAR]] = metadata !{{{.*}} null, null, i1 false, i1 true} +// BLACKLIST-SRC: ![[LITERAL]] = metadata !{{{.*}} null, null, i1 false, i1 true}