test/tsan/free_race.c

   1 // RUN: %clang_tsan -O1 %s -o %t
   2 // RUN: not %t 2>&1 | FileCheck %s --check-prefix=CHECK-NOZUPP
   3 // RUN: TSAN_OPTIONS="suppressions=%s.supp print_suppressions=1" %t 2>&1 | FileCheck %s --check-prefix=CHECK-SUPP
   4
   5 #include <pthread.h>
   6 #include <stdlib.h>
   7 #include <stdio.h>
   8 #include <stddef.h>
   9 #include <unistd.h>
  10
  11 int *mem;
  12 pthread_mutex_t mtx;
  13
  14 void *Thread1(void *x) {
  15   pthread_mutex_lock(&mtx);
  16   free(mem);
  17   pthread_mutex_unlock(&mtx);
  18   return NULL;
  19 }
  20
  21 void *Thread2(void *x) {
  22   sleep(1);
  23   pthread_mutex_lock(&mtx);
  24   mem[0] = 42;
  25   pthread_mutex_unlock(&mtx);
  26   return NULL;
  27 }
  28
  29 int main() {
  30   mem = (int*)malloc(100);
  31   pthread_mutex_init(&mtx, 0);
  32   pthread_t t;
  33   pthread_create(&t, NULL, Thread1, NULL);
  34   Thread2(0);
  35   pthread_join(t, NULL);
  36   pthread_mutex_destroy(&mtx);
  37   return 0;
  38 }
  39
  40 // CHECK-NOZUPP: WARNING: ThreadSanitizer: heap-use-after-free
  41 // CHECK-NOZUPP:   Write of size 4 at {{.*}} by main thread{{.*}}:
  42 // CHECK-NOZUPP:     #0 Thread2
  43 // CHECK-NOZUPP:     #1 main
  44 // CHECK-NOZUPP:   Previous write of size 8 at {{.*}} by thread T1{{.*}}:
  45 // CHECK-NOZUPP:     #0 free
  46 // CHECK-NOZUPP:     #{{(1|2)}} Thread1
  47 // CHECK-NOZUPP: SUMMARY: ThreadSanitizer: heap-use-after-free{{.*}}Thread2
  48 // CHECK-SUPP:   ThreadSanitizer: Matched 1 suppressions
  49 // CHECK-SUPP:    1 race:^Thread2$