compiler-rt/test/msan/dtls_test.c

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