libvtv/testsuite/temp_deriv2.cc

   1 // Compile with /home/llozano/local2/proj/vtable/gcc-root/usr/local/bin/g++ -m32 -fvtable-verify=std -fpic -rdynamic -Wl,-R,/home/llozano/local2/proj/vtable/gcc-root/usr/local/lib32:./lib32 -I/home/llozano/local2/proj/vtable/vt2/gcc-4_6-mobile-vtable-security//libstdc++-v3/libsupc++ temp_deriv.cc -O0 -ldl -lpthread -Wl,--whole-archive,-lvtv_init,--no-whole-archive,-z,relro -DTPID=0 -g
   2 // Look at assembly with: objdump -drl a.out
   3
   4 #include <dlfcn.h>
   5 #include <assert.h>
   6
   7 extern "C" int printf(const char *, ...);
   8
   9 static int counter = 0;
  10
  11 int i = TPID;
  12 struct base
  13 {
  14   virtual void inc() { counter += i; }
  15 };
  16
  17 struct derived: public base
  18 {
  19   virtual void inc() { counter += (10*i); }
  20 };
  21
  22 // We don't use this class. It is just here so that the
  23 // compiler does not devirtualize calls to derived::inc()
  24 struct derived2: public derived
  25 {
  26   virtual void inc() { counter += (20*i); }
  27 };
  28
  29 static base * bp = new base();
  30 static derived * dp = new derived();
  31 static base * dbp = new derived();
  32
  33 // Given 2 pointers to C++ objects (non PODs), exchange the pointers to vtable
  34 void exchange_vtptr(void * object1_ptr, void * object2_ptr)
  35 {
  36   typedef void * vtptr;
  37   vtptr * object1_vtptr_ptr = (vtptr *)object1_ptr;
  38   vtptr * object2_vtptr_ptr = (vtptr *)object2_ptr;
  39   vtptr object1_vtptr = *object1_vtptr_ptr;
  40   vtptr object2_vtptr = *object2_vtptr_ptr;
  41   *object1_vtptr_ptr = object2_vtptr;
  42   *object2_vtptr_ptr = object1_vtptr;
  43 }
  44
  45 main()
  46 {
  47   int prev_counter;
  48
  49   exchange_vtptr(bp, dp);
  50   exchange_vtptr(bp, dp);
  51   exchange_vtptr(bp, dbp);
  52   exchange_vtptr(bp, dbp);
  53
  54   counter = 0;
  55   bp->inc();
  56   dp->inc();
  57   dbp->inc();
  58   assert(counter == (TPID + 10*TPID + 10*TPID));
  59
  60   prev_counter = counter;
  61   exchange_vtptr(bp, dp);
  62   bp->inc(); // This one should succeed but it is calling the wrong member
  63   assert(counter == (prev_counter + 10*TPID));
  64   printf("Pass first attack!\n");
  65   dp->inc();
  66   printf("TPDI=%d counter %d\n", TPID, counter);
  67   printf("Pass second attack!\n");
  68
  69 }