compiler-rt/test/tsan/mmap_stress2.cpp

   1 // RUN: %clang_tsan -O1 %s -o %t && %env_tsan_opts=report_atomic_races=0 %run %t 2>&1 | FileCheck %s
   2 // This test exposed non-atomicity in mmap interceptor
   3 // which made shadow for the region temporarily unmapped.
   4 // This resulted in crashes in the Accesser thread.
   5 #include "test.h"
   6 #include <errno.h>
   7 #include <sys/mman.h>
   8
   9 // The size needs to be large enough to trigger
  10 // large region optimization in the runtime.
  11 const size_t kMmapSize = 16 << 20;
  12
  13 void *Remapper(void *arg) {
  14   for (;;) {
  15     void *p = mmap(arg, kMmapSize, PROT_READ | PROT_WRITE,
  16                    MAP_FIXED | MAP_PRIVATE | MAP_ANON, -1, 0);
  17     if (p == MAP_FAILED)
  18       exit(printf("mmap failed: %d\n", errno));
  19   }
  20   return 0;
  21 }
  22
  23 void *Accesser(void *arg) {
  24   unsigned rnd = time(0);
  25   for (;;) {
  26     int index = rand_r(&rnd) % kMmapSize;
  27     char *p = &((char *)arg)[index];
  28     __atomic_fetch_add(p, 1, __ATOMIC_ACQ_REL);
  29   }
  30   return 0;
  31 }
  32
  33 int main() {
  34   void *p = mmap(0, kMmapSize, PROT_READ | PROT_WRITE,
  35                  MAP_PRIVATE | MAP_ANON, -1, 0);
  36   if (p == MAP_FAILED)
  37     exit(printf("mmap failed: %d\n", errno));
  38   pthread_attr_t attr;
  39   pthread_attr_init(&attr);
  40   pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
  41   pthread_t th[2];
  42   if (pthread_create(&th[0], &attr, Remapper, p))
  43     exit(printf("pthread_create failed: %d\n", errno));
  44   if (pthread_create(&th[1], &attr, Accesser, p))
  45     exit(printf("pthread_create failed: %d\n", errno));
  46   pthread_attr_destroy(&attr);
  47   sleep(3);
  48   fprintf(stderr, "DONE\n");
  49 }
  50
  51 // CHECK: DONE