Author: samsonov Date: Fri Jul 18 13:15:39 2014 New Revision: 213393 URL: http://llvm.org/viewvc/llvm-project?rev=213393&view=rev Log: [UBsan] Skip -fsanitize=vptr instrumentations when the pointer value is null.
Otherwise -fsanitize=vptr causes the program to crash when it downcasts a null pointer. Reviewed in http://reviews.llvm.org/D4412. Patch by Byoungyoung Lee! Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp 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=213393&r1=213392&r2=213393&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CGExpr.cpp (original) +++ cfe/trunk/lib/CodeGen/CGExpr.cpp Fri Jul 18 13:15:39 2014 @@ -463,7 +463,7 @@ void CodeGenFunction::EmitTypeCheck(Type llvm::Value *Cond = nullptr; llvm::BasicBlock *Done = nullptr; - if (SanOpts->Null) { + if (SanOpts->Null || TCK == TCK_DowncastPointer) { // The glvalue must not be an empty glvalue. Cond = Builder.CreateICmpNE( Address, llvm::Constant::getNullValue(Address->getType())); 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=213393&r1=213392&r2=213393&view=diff ============================================================================== --- cfe/trunk/test/CodeGenCXX/catch-undef-behavior.cpp (original) +++ cfe/trunk/test/CodeGenCXX/catch-undef-behavior.cpp Fri Jul 18 13:15:39 2014 @@ -1,5 +1,6 @@ // 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 +// RUN: %clang_cc1 -std=c++11 -fsanitize=vptr -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefix=DOWNCAST-NULL struct S { double d; @@ -190,10 +191,15 @@ int bad_enum_value() { } // CHECK-LABEL: @_Z20bad_downcast_pointer +// DOWNCAST-NULL-LABEL: @_Z20bad_downcast_pointer void bad_downcast_pointer(S *p) { // CHECK: %[[NONNULL:.*]] = icmp ne {{.*}}, null // CHECK: br i1 %[[NONNULL]], + // A null poiner access is guarded without -fsanitize=null. + // DOWNCAST-NULL: %[[NONNULL:.*]] = icmp ne {{.*}}, null + // DOWNCAST-NULL: br i1 %[[NONNULL]], + // CHECK: %[[SIZE:.*]] = call i64 @llvm.objectsize.i64.p0i8( // CHECK: %[[E1:.*]] = icmp uge i64 %[[SIZE]], 24 // CHECK: %[[MISALIGN:.*]] = and i64 %{{.*}}, 7 _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
