lib/msan/lit_tests/signal_stress_test.cc

   1 // RUN: %clangxx_msan -std=c++11 -O0 %s -o %t && %t
   2
   3 // Test that va_arg shadow from a signal handler does not leak outside.
   4
   5 #include <signal.h>
   6 #include <stdarg.h>
   7 #include <sanitizer/msan_interface.h>
   8 #include <assert.h>
   9 #include <sys/time.h>
  10 #include <stdio.h>
  11
  12 const int kSigCnt = 200;
  13
  14 void f(bool poisoned, int n, ...) {
  15   va_list vl;
  16   va_start(vl, n);
  17   for (int i = 0; i < n; ++i) {
  18     void *p = va_arg(vl, void *);
  19     if (!poisoned)
  20       assert(__msan_test_shadow(&p, sizeof(p)) == -1);
  21   }
  22   va_end(vl);
  23 }
  24
  25 int sigcnt;
  26
  27 void SignalHandler(int signo) {
  28   assert(signo == SIGPROF);
  29   void *p;
  30   void **volatile q = &p;
  31   f(true, 10,
  32     *q, *q, *q, *q, *q,
  33     *q, *q, *q, *q, *q);
  34   ++sigcnt;
  35 }
  36
  37 int main() {
  38   signal(SIGPROF, SignalHandler);
  39
  40   itimerval itv;
  41   itv.it_interval.tv_sec = 0;
  42   itv.it_interval.tv_usec = 100;
  43   itv.it_value.tv_sec = 0;
  44   itv.it_value.tv_usec = 100;
  45   setitimer(ITIMER_PROF, &itv, NULL);
  46
  47   void *p;
  48   void **volatile q = &p;
  49
  50   do {
  51     f(false, 20,
  52       nullptr, nullptr, nullptr, nullptr, nullptr,
  53       nullptr, nullptr, nullptr, nullptr, nullptr,
  54       nullptr, nullptr, nullptr, nullptr, nullptr,
  55       nullptr, nullptr, nullptr, nullptr, nullptr);
  56     f(true, 20,
  57       *q, *q, *q, *q, *q,
  58       *q, *q, *q, *q, *q,
  59       *q, *q, *q, *q, *q,
  60       *q, *q, *q, *q, *q);
  61   } while (sigcnt < kSigCnt);
  62
  63   itv.it_interval.tv_sec = 0;
  64   itv.it_interval.tv_usec = 0;
  65   itv.it_value.tv_sec = 0;
  66   itv.it_value.tv_usec = 0;
  67   setitimer(ITIMER_PROF, &itv, NULL);
  68
  69   signal(SIGPROF, SIG_DFL);
  70   return 0;
  71 }