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 // REQUIRES: x86_64-target-arch
   6
   7 #include <assert.h>
   8 #include <pthread.h>
   9 #include <sanitizer/dfsan_interface.h>
  10 #include <stdlib.h>
  11
  12 static unsigned char GlobalBuf[4096];
  13 static int ShutDownThread;
  14 static int StartFlush;
  15
  16 // Access GlobalBuf continuously, causing its shadow to be touched as well.
  17 // When main() calls dfsan_flush(), no segfault should be triggered.
  18 static void *accessGlobalInBackground(void *Arg) {
  19   __atomic_store_n(&StartFlush, 1, __ATOMIC_RELEASE);
  20
  21   while (!__atomic_load_n(&ShutDownThread, __ATOMIC_ACQUIRE))
  22     for (unsigned I = 0; I < sizeof(GlobalBuf); ++I)
  23       ++GlobalBuf[I];
  24
  25   return NULL;
  26 }
  27
  28 int main() {
  29   pthread_t Thread;
  30   pthread_create(&Thread, NULL, accessGlobalInBackground, NULL);
  31   while (!__atomic_load_n(&StartFlush, __ATOMIC_ACQUIRE))
  32     ; // Spin
  33
  34   dfsan_flush();
  35
  36   __atomic_store_n(&ShutDownThread, 1, __ATOMIC_RELEASE);
  37   pthread_join(Thread, NULL);
  38   return 0;
  39 }