compiler-rt/test/tsan/ignored-interceptors-mmap.cpp

   1 // RUN: %clangxx_tsan -O0 %s -o %t
   2 // RUN: not %run %t          2>&1 | FileCheck %s --check-prefix=CHECK-RACE
   3 // Test size larger than clear_shadow_mmap_threshold, which is handled differently.
   4 // RUN: not %run %t - 262144 2>&1 | FileCheck %s --check-prefix=CHECK-RACE
   5 // RUN:     %run %t ignore   2>&1 | FileCheck %s --check-prefix=CHECK-IGNORE
   6
   7 #include <sys/mman.h>
   8 #include <string.h>
   9 #include <assert.h>
  10 #include <atomic>
  11
  12 #include "test.h"
  13
  14 // Use atomic to ensure we do not have a race for the pointer value itself.  We
  15 // only want to check races in the mmap'd memory to isolate the test that mmap
  16 // respects ignore annotations.
  17 std::atomic<int*> global_p;
  18
  19 void mmap_ignored(bool ignore, size_t size) {
  20   if (ignore) AnnotateIgnoreWritesBegin(__FILE__, __LINE__);
  21   void *p =
  22       mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
  23   if (ignore) AnnotateIgnoreWritesEnd(__FILE__, __LINE__);
  24
  25   // Use relaxed to retain the race between the mmap call and the memory write
  26   global_p.store((int *)p, std::memory_order_relaxed);
  27   barrier_wait(&barrier);
  28 }
  29
  30 void *WriteToMemory(void *unused) {
  31   barrier_wait(&barrier);
  32   global_p[0] = 7;
  33   return 0;
  34 }
  35
  36 // Create race between allocating (mmap) and writing memory
  37 int main(int argc, const char *argv[]) {
  38   bool ignore = (argc > 1) && (strcmp(argv[1], "ignore") == 0);
  39   size_t size = argc > 2 ? atoi(argv[2]) : sysconf(_SC_PAGESIZE);
  40
  41   barrier_init(&barrier, 2);
  42   pthread_t t;
  43   pthread_create(&t, 0, WriteToMemory, 0);
  44   mmap_ignored(ignore, size);
  45   pthread_join(t, 0);
  46
  47   assert(global_p[0] == 7);
  48   printf("OK\n");
  49   return 0;
  50 }
  51
  52 // CHECK-RACE: WARNING: ThreadSanitizer: data race
  53 // CHECK-RACE: OK
  54 // CHECK-IGNORE-NOT: WARNING: ThreadSanitizer: data race
  55 // CHECK-IGNORE: OK