src/compiler-rt/test/ubsan/TestCases/TypeCheck/vptr-corrupted-vtable-itanium.cpp

   1 // RUN: %clangxx -frtti -fsanitize=vptr -fno-sanitize-recover=vptr -g %s -O3 -o %t
   2 // RUN: not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-CORRUPTED-VTABLE --strict-whitespace
   3
   4 // UNSUPPORTED: win32
   5 // REQUIRES: stable-runtime, cxxabi
   6 #include <cstddef>
   7
   8 #include <typeinfo>
   9
  10 struct S {
  11   S() {}
  12   ~S() {}
  13   virtual int v() { return 0; }
  14 };
  15
  16 // See the proper definition in ubsan_type_hash_itanium.cc
  17 struct VtablePrefix {
  18   signed long Offset;
  19   std::type_info *TypeInfo;
  20 };
  21
  22 int main(int argc, char **argv) {
  23   // Test that we don't crash on corrupted vtable when
  24   // offset is too large or too small.
  25   S Obj;
  26   void *Ptr = &Obj;
  27   VtablePrefix* RealPrefix = reinterpret_cast<VtablePrefix*>(
  28       *reinterpret_cast<void**>(Ptr)) - 1;
  29
  30   VtablePrefix Prefix[2];
  31   Prefix[0].Offset = 1<<21; // Greater than VptrMaxOffset
  32   Prefix[0].TypeInfo = RealPrefix->TypeInfo;
  33
  34   // Hack Vtable ptr for Obj.
  35   *reinterpret_cast<void**>(Ptr) = static_cast<void*>(&Prefix[1]);
  36
  37   // CHECK-CORRUPTED-VTABLE: vptr-corrupted-vtable-itanium.cpp:[[@LINE+3]]:16: runtime error: member call on address [[PTR:0x[0-9a-f]*]] which does not point to an object of type 'S'
  38   // CHECK-CORRUPTED-VTABLE-NEXT: [[PTR]]: note: object has a possibly invalid vptr: abs(offset to top) too big
  39   S* Ptr2 = reinterpret_cast<S*>(Ptr);
  40   return Ptr2->v();
  41 }