test/msan/wrap_indirect_calls_in_rtl.cc

   1 // Test indirect call wrapping in MemorySanitizer runtime.
   2
   3 // RUN: %clangxx_msan -O0 -g -rdynamic %s -o %t && %run %t
   4
   5 #include <assert.h>
   6 #include <math.h>
   7 #include <pthread.h>
   8 #include <stdio.h>
   9 #include <stdint.h>
  10 #include <sys/time.h>
  11
  12 extern "C" void __msan_set_indirect_call_wrapper(uintptr_t);
  13
  14 bool pthread_create_done;
  15
  16 void *ThreadFn(void *) {
  17   printf("bad threadfn\n");
  18   return 0;
  19 }
  20
  21 void *ThreadFn2(void *) {
  22   printf("good threadfn\n");
  23   pthread_create_done = true;
  24   return 0;
  25 }
  26
  27 bool in_gettimeofday;
  28 bool in_lgamma;
  29
  30 int my_gettimeofday(struct timeval *p, void *q) {
  31   p->tv_sec = 1;
  32   p->tv_usec = 2;
  33   return 42;
  34 }
  35
  36 double my_lgamma(double x) {
  37   return x;
  38 }
  39
  40 extern "C" uintptr_t my_wrapper(uintptr_t f) {
  41   if (f == (uintptr_t)ThreadFn)
  42     return (uintptr_t)&ThreadFn2;
  43   if (in_gettimeofday)
  44     return (uintptr_t)my_gettimeofday;
  45   if (in_lgamma)
  46     return (uintptr_t)my_lgamma;
  47   return f;
  48 }
  49
  50 int main(void) {
  51   __msan_set_indirect_call_wrapper((uintptr_t)my_wrapper);
  52
  53   // ThreadFn is called indirectly from a wrapper function in MSan rtl and
  54   // is subject to indirect call wrapping (it could be an native-to-translated
  55   // edge).
  56   pthread_t t;
  57   pthread_create(&t, 0, ThreadFn, 0);
  58   pthread_join(t, 0);
  59   assert(pthread_create_done);
  60
  61   // gettimeofday is intercepted in msan_interceptors.cc and the real one (from
  62   // libc) is called indirectly.
  63   struct timeval tv;
  64   in_gettimeofday = true;
  65   int res = gettimeofday(&tv, NULL);
  66   in_gettimeofday = false;
  67   assert(tv.tv_sec == 1);
  68   assert(tv.tv_usec == 2);
  69   assert(res == 42);
  70
  71   // lgamma is intercepted in sanitizer_common_interceptors.inc and is also
  72   // called indirectly.
  73   in_lgamma = true;
  74   double dres = lgamma(1.1);
  75   in_lgamma = false;
  76   assert(dres == 1.1);
  77
  78   return 0;
  79 }