free_race.c revision 6a211c5814e25d6745a5058cc0e499e5235d3821 
1// RUN: %clang_tsan -O1 %s -o %t
2// RUN: %deflake %run %t | FileCheck %s --check-prefix=CHECK-NOZUPP
3// RUN: TSAN_OPTIONS="suppressions=%s.supp print_suppressions=1" %run %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
11int *mem;
12pthread_mutex_t mtx;
13
14void *Thread1(void *x) {
15  pthread_mutex_lock(&mtx);
16  free(mem);
17  pthread_mutex_unlock(&mtx);
18  return NULL;
19}
20
21void *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
29int 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$
50