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Basic code generation for MSan use-after-dtor. 

Under the -fsanitize-memory-use-after-dtor (disabled by default) insert
an MSan runtime library call at the end of every destructor.

Patch by Naomi Musgrave.

llvm-svn: 242097
This commit is contained in:
Evgeniy Stepanov 2015-07-14 00:34:50 +00:00
parent 2c4af3ead7
commit 7cacbe4d9e
2 changed files with 40 additions and 0 deletions
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23
clang/lib/CodeGen/CGClass.cpp
View File

@ -1357,6 +1357,25 @@ static bool CanSkipVTablePointerInitialization(ASTContext &Context,
return true;
}
// Generates function call for handling object poisoning, passing in
// references to 'this' and its size as arguments.
static void EmitDtorSanitizerCallback(CodeGenFunction &CGF,
const CXXDestructorDecl *Dtor) {
const ASTRecordLayout &Layout =
CGF.getContext().getASTRecordLayout(Dtor->getParent());
llvm::Value *Args[] = {
CGF.Builder.CreateBitCast(CGF.LoadCXXThis(), CGF.VoidPtrTy),
llvm::ConstantInt::get(CGF.SizeTy, Layout.getSize().getQuantity())};
llvm::Type *ArgTypes[] = {CGF.VoidPtrTy, CGF.SizeTy};
llvm::FunctionType *FnType =
llvm::FunctionType::get(CGF.VoidTy, ArgTypes, false);
llvm::Value *Fn =
CGF.CGM.CreateRuntimeFunction(FnType, "__sanitizer_dtor_callback");
CGF.EmitNounwindRuntimeCall(Fn, Args);
}
/// EmitDestructorBody - Emits the body of the current destructor.
void CodeGenFunction::EmitDestructorBody(FunctionArgList &Args) {
const CXXDestructorDecl *Dtor = cast<CXXDestructorDecl>(CurGD.getDecl());
@ -1444,6 +1463,10 @@ void CodeGenFunction::EmitDestructorBody(FunctionArgList &Args) {
// Exit the try if applicable.
if (isTryBody)
ExitCXXTryStmt(*cast<CXXTryStmt>(Body), true);
// Insert memory-poisoning instrumentation.
if (CGM.getCodeGenOpts().SanitizeMemoryUseAfterDtor)
EmitDtorSanitizerCallback(*this, Dtor);
}
void CodeGenFunction::emitImplicitAssignmentOperatorBody(FunctionArgList &Args) {

17
clang/test/CodeGenCXX/sanitize-dtor-callback.cpp Normal file
View File

@ -0,0 +1,17 @@
// Test -fsanitize-memory-use-after-dtor
// RUN: %clang_cc1 -fsanitize=memory -fsanitize-memory-use-after-dtor -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s
// RUN: %clang_cc1 -fsanitize=memory -triple=x86_64-pc-linux -emit-llvm -o - %s | FileCheck %s -check-prefix=NO_DTOR_CHECK
struct Simple {
~Simple() {}
};
Simple s;
// Simple internal member is poisoned by compiler-generated dtor
// CHECK-LABEL: @_ZN6SimpleD2Ev
// CHECK: call void @__sanitizer_dtor_callback
// CHECK: ret void
// Compiling without the flag does not generate member-poisoning dtor
// NO_DTOR_CHECK-LABEL: @_ZN6SimpleD2Ev
// NO_DTOR_CHECK-NOT: call void @sanitizer_dtor_callback
// NO_DTOR_CHECK: ret void