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 XFAIL: FreeBSD
10 UNSUPPORTED: powerpc
11
12 // Reports use-of-uninitialized-value, not analyzed
13 XFAIL: netbsd
14
15 // This is known to be broken with glibc-2.27+
16 // https://bugs.llvm.org/show_bug.cgi?id=37804
17 XFAIL: glibc-2.27
18
19 */
20
21 #ifndef BUILD_SO
22 #include <assert.h>
23 #include <dlfcn.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <pthread.h>
27
28 typedef long *(* get_t)();
29 get_t GetTls;
Thread1(void * unused)30 void *Thread1(void *unused) {
31 long uninitialized;
32 long *x = GetTls();
33 if (*x)
34 fprintf(stderr, "bar\n");
35 *x = uninitialized;
36 fprintf(stderr, "stack: %p dtls: %p\n", &x, x);
37 return 0;
38 }
39
Thread2(void * unused)40 void *Thread2(void *unused) {
41 long *x = GetTls();
42 fprintf(stderr, "stack: %p dtls: %p\n", &x, x);
43 if (*x)
44 fprintf(stderr, "foo\n"); // False negative here.
45 return 0;
46 }
47
main(int argc,char * argv[])48 int main(int argc, char *argv[]) {
49 char path[4096];
50 snprintf(path, sizeof(path), "%s-so.so", argv[0]);
51 int i;
52
53 void *handle = dlopen(path, RTLD_LAZY);
54 if (!handle) fprintf(stderr, "%s\n", dlerror());
55 assert(handle != 0);
56 GetTls = (get_t)dlsym(handle, "GetTls");
57 assert(dlerror() == 0);
58
59 pthread_t t;
60 pthread_create(&t, 0, Thread1, 0);
61 pthread_join(t, 0);
62 pthread_create(&t, 0, Thread2, 0);
63 pthread_join(t, 0);
64 return 0;
65 }
66 #else // BUILD_SO
67 __thread long huge_thread_local_array[1 << 17];
GetTls()68 long *GetTls() {
69 return &huge_thread_local_array[0];
70 }
71 #endif
72