1 /* RUN: %clang_msan -g %s -o %t
2 RUN: %clang_msan -g %s -DBUILD_SO -fPIC -o %t-so.so -shared
3 RUN: %run %t 2>&1
4
5 Regression test for a bug in msan/glibc integration,
6 see https://sourceware.org/bugzilla/show_bug.cgi?id=16291
7 and https://github.com/google/sanitizers/issues/547
8 */
9
10 #ifndef BUILD_SO
11 #include <assert.h>
12 #include <dlfcn.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <pthread.h>
16
17 typedef long *(* get_t)();
18 get_t GetTls;
Thread1(void * unused)19 void *Thread1(void *unused) {
20 long uninitialized;
21 long *x = GetTls();
22 if (*x)
23 fprintf(stderr, "bar\n");
24 *x = uninitialized;
25 fprintf(stderr, "stack: %p dtls: %p\n", &x, x);
26 return 0;
27 }
28
Thread2(void * unused)29 void *Thread2(void *unused) {
30 long *x = GetTls();
31 fprintf(stderr, "stack: %p dtls: %p\n", &x, x);
32 if (*x)
33 fprintf(stderr, "foo\n"); // False negative here.
34 return 0;
35 }
36
main(int argc,char * argv[])37 int main(int argc, char *argv[]) {
38 char path[4096];
39 snprintf(path, sizeof(path), "%s-so.so", argv[0]);
40 int i;
41
42 void *handle = dlopen(path, RTLD_LAZY);
43 if (!handle) fprintf(stderr, "%s\n", dlerror());
44 assert(handle != 0);
45 GetTls = (get_t)dlsym(handle, "GetTls");
46 assert(dlerror() == 0);
47
48 pthread_t t;
49 pthread_create(&t, 0, Thread1, 0);
50 pthread_join(t, 0);
51 pthread_create(&t, 0, Thread2, 0);
52 pthread_join(t, 0);
53 return 0;
54 }
55 #else // BUILD_SO
56 __thread long huge_thread_local_array[1 << 17];
GetTls()57 long *GetTls() {
58 return &huge_thread_local_array[0];
59 }
60 #endif
61