compiler-rt/test/dfsan/threaded_flush.c

   1 // Tests that doing dfsan_flush() while another thread is executing doesn't
   2 // segfault.
   3 // RUN: %clang_dfsan %s -o %t && %run %t
   4
   5 #include <assert.h>
   6 #include <pthread.h>
   7 #include <sanitizer/dfsan_interface.h>
   8 #include <stdlib.h>
   9
  10 static unsigned char GlobalBuf[4096];
  11 static int ShutDownThread;
  12 static int StartFlush;
  13
  14 // Access GlobalBuf continuously, causing its shadow to be touched as well.
  15 // When main() calls dfsan_flush(), no segfault should be triggered.
  16 static void *accessGlobalInBackground(void *Arg) {
  17   __atomic_store_n(&StartFlush, 1, __ATOMIC_RELEASE);
  18
  19   while (!__atomic_load_n(&ShutDownThread, __ATOMIC_ACQUIRE))
  20     for (unsigned I = 0; I < sizeof(GlobalBuf); ++I)
  21       ++GlobalBuf[I];
  22
  23   return NULL;
  24 }
  25
  26 int main() {
  27   pthread_t Thread;
  28   pthread_create(&Thread, NULL, accessGlobalInBackground, NULL);
  29   while (!__atomic_load_n(&StartFlush, __ATOMIC_ACQUIRE))
  30     ; // Spin
  31
  32   dfsan_flush();
  33
  34   __atomic_store_n(&ShutDownThread, 1, __ATOMIC_RELEASE);
  35   pthread_join(Thread, NULL);
  36   return 0;
  37 }