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[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.

llvm-svn: 212872
This commit is contained in:
Alexey Samsonov 2014-07-12 00:42:52 +00:00
parent fc31efe95a
commit 15c9669615
9 changed files with 86 additions and 47 deletions
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2
clang/lib/CodeGen/CGDecl.cpp
View File

@ -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();

42
clang/lib/CodeGen/CodeGenModule.cpp
View File

@ -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), "<string literal>");
return GV;
}

4
clang/lib/CodeGen/CodeGenModule.h
View File

@ -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);

24
clang/test/CodeGen/asan-globals.cpp
View File

@ -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"<string literal>\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}

2
compiler-rt/test/asan/TestCases/global-location.cc
View File

@ -27,7 +27,7 @@ int main(int argc, char **argv) {
case 'c': return C::array[one * 11];
case 'f':
static int array[10];
// FUNC_STATIC: 0x{{.*}} is located 4 bytes to the right of global variable 'main::array' defined in '{{.*}}global-location.cc:[[@LINE-1]]:16' {{.*}} of size 40
// FUNC_STATIC: 0x{{.*}} is located 4 bytes to the right of global variable 'array' defined in '{{.*}}global-location.cc:[[@LINE-1]]:16' {{.*}} of size 40
memset(array, 0, 10);
return array[one * 11];
case 'l':

29
llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
View File

@ -216,8 +216,11 @@ namespace {
class GlobalsMetadata {
public:
struct Entry {
Entry() : SourceLoc(nullptr), IsDynInit(false), IsBlacklisted(false) {}
Entry()
: SourceLoc(nullptr), Name(nullptr), IsDynInit(false),
IsBlacklisted(false) {}
GlobalVariable *SourceLoc;
GlobalVariable *Name;
bool IsDynInit;
bool IsBlacklisted;
};
@ -232,7 +235,7 @@ class GlobalsMetadata {
return;
for (auto MDN : Globals->operands()) {
// Metadata node contains the global and the fields of "Entry".
assert(MDN->getNumOperands() == 4);
assert(MDN->getNumOperands() == 5);
Value *V = MDN->getOperand(0);
// The optimizer may optimize away a global entirely.
if (!V)
@ -246,9 +249,14 @@ class GlobalsMetadata {
E.SourceLoc = GVLoc;
addSourceLocationGlobal(GVLoc);
}
ConstantInt *IsDynInit = cast<ConstantInt>(MDN->getOperand(2));
if (Value *Name = MDN->getOperand(2)) {
GlobalVariable *GVName = cast<GlobalVariable>(Name);
E.Name = GVName;
InstrumentationGlobals.insert(GVName);
}
ConstantInt *IsDynInit = cast<ConstantInt>(MDN->getOperand(3));
E.IsDynInit |= IsDynInit->isOne();
ConstantInt *IsBlacklisted = cast<ConstantInt>(MDN->getOperand(3));
ConstantInt *IsBlacklisted = cast<ConstantInt>(MDN->getOperand(4));
E.IsBlacklisted |= IsBlacklisted->isOne();
}
}
@ -1049,6 +1057,14 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M) {
for (size_t i = 0; i < n; i++) {
static const uint64_t kMaxGlobalRedzone = 1 << 18;
GlobalVariable *G = GlobalsToChange[i];
auto MD = GlobalsMD.get(G);
// Create string holding the global name unless it was provided by
// the metadata.
GlobalVariable *Name =
MD.Name ? MD.Name : createPrivateGlobalForString(M, G->getName(),
/*AllowMerging*/ true);
PointerType *PtrTy = cast<PointerType>(G->getType());
Type *Ty = PtrTy->getElementType();
uint64_t SizeInBytes = DL->getTypeAllocSize(Ty);
@ -1070,9 +1086,6 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M) {
NewTy, G->getInitializer(),
Constant::getNullValue(RightRedZoneTy), NULL);
GlobalVariable *Name =
createPrivateGlobalForString(M, G->getName(), /*AllowMerging*/true);
// Create a new global variable with enough space for a redzone.
GlobalValue::LinkageTypes Linkage = G->getLinkage();
if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
@ -1092,8 +1105,6 @@ bool AddressSanitizerModule::InstrumentGlobals(IRBuilder<> &IRB, Module &M) {
NewGlobal->takeName(G);
G->eraseFromParent();
auto MD = GlobalsMD.get(G);
Initializers[i] = ConstantStruct::get(
GlobalStructTy, ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
ConstantInt::get(IntptrTy, SizeInBytes),

20
llvm/test/Instrumentation/AddressSanitizer/global_metadata.ll
View File

@ -18,12 +18,20 @@ target triple = "x86_64-unknown-linux-gnu"
@.asan_loc_descr2 = private unnamed_addr constant { [22 x i8]*, i32, i32 } { [22 x i8]* @.str1, i32 12, i32 14 }
@.asan_loc_descr4 = private unnamed_addr constant { [22 x i8]*, i32, i32 } { [22 x i8]* @.str1, i32 14, i32 25 }
; Global names:
@.str2 = private unnamed_addr constant [7 x i8] c"global\00", align 1
@.str3 = private unnamed_addr constant [16 x i8] c"dyn_init_global\00", align 1
@.str4 = private unnamed_addr constant [11 x i8] c"static_var\00", align 1
@.str5 = private unnamed_addr constant [17 x i8] c"<string literal>\00", align 1
; Check that globals were instrumented, but sanitizer location descriptors weren't:
; CHECK: @global = global { i32, [60 x i8] } zeroinitializer, align 32
; CHECK: @.str = internal unnamed_addr constant { [14 x i8], [50 x i8] } { [14 x i8] c"Hello, world!\00", [50 x i8] zeroinitializer }, align 32
; CHECK: @.asan_loc_descr = private unnamed_addr constant { [22 x i8]*, i32, i32 } { [22 x i8]* @.str1, i32 5, i32 5 }
; CHECK: @.str2 = private unnamed_addr constant [7 x i8] c"global\00", align 1
; Check that location decriptors were passed into __asan_register_globals:
; Check that location decriptors and global names were passed into __asan_register_globals:
; CHECK: i64 ptrtoint ([7 x i8]* @.str2 to i64)
; CHECK: i64 ptrtoint ({ [22 x i8]*, i32, i32 }* @.asan_loc_descr to i64)
; Function Attrs: nounwind sanitize_address
@ -55,9 +63,9 @@ attributes #1 = { nounwind sanitize_address "less-precise-fpmad"="false" "no-fra
!llvm.asan.globals = !{!0, !1, !2, !3, !4}
!llvm.ident = !{!5}
!0 = metadata !{i32* @global, { [22 x i8]*, i32, i32 }* @.asan_loc_descr, i1 false, i1 false}
!1 = metadata !{i32* @dyn_init_global, { [22 x i8]*, i32, i32 }* @.asan_loc_descr1, i1 true, i1 false}
!2 = metadata !{i32* @blacklisted_global, null, i1 false, i1 true}
!3 = metadata !{i32* @_ZZ4funcvE10static_var, { [22 x i8]*, i32, i32 }* @.asan_loc_descr2, i1 false, i1 false}
!4 = metadata !{[14 x i8]* @.str, { [22 x i8]*, i32, i32 }* @.asan_loc_descr4, i1 false, i1 false}
!0 = metadata !{i32* @global, { [22 x i8]*, i32, i32 }* @.asan_loc_descr, [7 x i8]* @.str2, i1 false, i1 false}
!1 = metadata !{i32* @dyn_init_global, { [22 x i8]*, i32, i32 }* @.asan_loc_descr1, [16 x i8]* @.str3, i1 true, i1 false}
!2 = metadata !{i32* @blacklisted_global, null, null, i1 false, i1 true}
!3 = metadata !{i32* @_ZZ4funcvE10static_var, { [22 x i8]*, i32, i32 }* @.asan_loc_descr2, [11 x i8]* @.str4, i1 false, i1 false}
!4 = metadata !{[14 x i8]* @.str, { [22 x i8]*, i32, i32 }* @.asan_loc_descr4, [17 x i8]* @.str5, i1 false, i1 false}
!5 = metadata !{metadata !"clang version 3.5.0 (211282)"}

2
llvm/test/Instrumentation/AddressSanitizer/instrument_global.ll
View File

@ -69,7 +69,7 @@ entry:
!llvm.asan.globals = !{!0}
!0 = metadata !{[10 x i32]* @GlobDy, null, i1 true, i1 false}
!0 = metadata !{[10 x i32]* @GlobDy, null, null, i1 true, i1 false}
; CHECK-LABEL: define internal void @asan.module_ctor
; CHECK-NOT: ret

8
llvm/test/Instrumentation/AddressSanitizer/instrument_initializer_metadata.ll
View File

@ -7,10 +7,10 @@ target triple = "x86_64-unknown-linux-gnu"
@YYY = global i32 0, align 4 ; W/o dynamic initializer.
; Clang will emit the following metadata identifying @xxx as dynamically
; initialized.
!0 = metadata !{i32* @xxx, null, i1 true, i1 false}
!1 = metadata !{i32* @XXX, null, i1 true, i1 false}
!2 = metadata !{i32* @yyy, null, i1 false, i1 false}
!3 = metadata !{i32* @YYY, null, i1 false, i1 false}
!0 = metadata !{i32* @xxx, null, null, i1 true, i1 false}
!1 = metadata !{i32* @XXX, null, null, i1 true, i1 false}
!2 = metadata !{i32* @yyy, null, null, i1 false, i1 false}
!3 = metadata !{i32* @YYY, null, null, i1 false, i1 false}
!llvm.asan.globals = !{!0, !1, !2, !3}
define i32 @initializer() uwtable {