libvtv/testsuite/other-tests/so.cc

   1 #include <dlfcn.h>
   2 #include <assert.h>
   3 #include <unistd.h>
   4 #include <vtv_fail.h>
   5
   6 extern "C" int printf(const char *, ...);
   7 extern "C" int sprintf(char *, const char*, ...);
   8
   9 static int counter = 0;
  10 extern int failures;
  11
  12 template <int i> struct base
  13 {
  14   virtual char * whoami() {
  15     static char sl[100];
  16     sprintf(sl, "I am base %d", i);
  17     return sl;
  18   }
  19   virtual void inc() { counter += i; }
  20 };
  21
  22 template <int i> struct derived: base<i>
  23 {
  24   virtual char * whoami() {
  25     static char sl[100];
  26     sprintf(sl, "I am derived %d", i);
  27     return sl;
  28   }
  29   virtual void inc() { counter += (10*i); }
  30 };
  31
  32 // We don't use this class. It is just here so that the
  33 // compiler does not devirtualize calls to derived::inc()
  34 template <int i> struct derived2: derived<i>
  35 {
  36   virtual void inc() { counter += (20*i); }
  37 };
  38
  39 static base<TPID> * bp = new base<TPID>();
  40 static derived<TPID> * dp = new derived<TPID>();
  41 static base<TPID> * dbp = new derived<TPID>();
  42
  43
  44 // Given 2 pointers to C++ objects (non PODs), exchange the pointers to vtable
  45 static void exchange_vtptr(void * object1_ptr, void * object2_ptr)
  46 {
  47   void ** object1_vtptr_ptr = (void **)object1_ptr;
  48   void ** object2_vtptr_ptr = (void **)object2_ptr;
  49   void * object1_vtptr = *object1_vtptr_ptr;
  50   void * object2_vtptr = *object2_vtptr_ptr;
  51   *object1_vtptr_ptr = object2_vtptr;
  52   *object2_vtptr_ptr = object1_vtptr;
  53 }
  54
  55 #define BUILD_NAME(NAME,ID) NAME##ID
  56 #define EXPAND(NAME,X) BUILD_NAME(NAME,X)
  57 extern "C" void EXPAND(so_entry_,TPID)(void)
  58 {
  59   int prev_counter;
  60   int prev_failures;
  61
  62   counter = 0;
  63   bp->inc();
  64   dp->inc();
  65   dbp->inc();
  66   assert(counter == (TPID + 10*TPID + 10*TPID));
  67
  68   prev_counter = counter;
  69   exchange_vtptr(bp, dp);
  70   bp->inc(); // This one should succeed but it is calling the wrong member
  71   if (counter != (prev_counter + 10*TPID))
  72   {
  73     printf("TPID=%d whoami=%s wrong counter value prev_counter=%d counter=%d\n", TPID, bp->whoami(), prev_counter, counter);
  74     sleep(2);
  75   }
  76   assert(counter == (prev_counter + 10*TPID));
  77   //  printf("Pass first attack!\n");
  78
  79  // This one should fail verification!. So it should jump to __vtv_verify_fail above.
  80   prev_failures = failures;
  81   dp->inc();
  82   // this code may be executed by multiple threads at the same time. So, just verify the number of failures has
  83   // increased as opposed to check for increase by 1.
  84   assert(failures > prev_failures);
  85   assert(counter == (prev_counter + 10*TPID + TPID));
  86   //  printf("TPDI=%d counter %d\n", TPID, counter);
  87   //  printf("Pass second attack!\n");
  88
  89   // restore the vtable pointers to the original state.
  90   // This is very important. For some reason the dlclose is not "really" closing the library so when we reopen it we are
  91   // getting the old memory state.
  92   exchange_vtptr(bp, dp);
  93 }