Index: compiler-rt/trunk/test/builtins/Unit/compiler_rt_logb_test.c
===================================================================
--- compiler-rt/trunk/test/builtins/Unit/compiler_rt_logb_test.c
+++ compiler-rt/trunk/test/builtins/Unit/compiler_rt_logb_test.c
@@ -36,6 +36,10 @@
 };
 
 int main() {
+  // Do not the run the compiler-rt logb test case if using GLIBC version
+  // < 2.23. Older versions might not compute to the same value as the
+  // compiler-rt value.
+#if !defined(__GLIBC__) || (defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 23))
   const unsigned N = sizeof(cases) / sizeof(cases[0]);
   unsigned i;
   for (i = 0; i < N; ++i) {
@@ -57,6 +61,9 @@
     if (test__compiler_rt_logb(fromRep(signBit ^ x))) return 1;
     x >>= 1;
   }
+#else
+  printf("skipped\n");
+#endif
 
   return 0;
 }
Index: compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/getpw_getgr.cc
===================================================================
--- compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/getpw_getgr.cc
+++ compiler-rt/trunk/test/sanitizer_common/TestCases/Posix/getpw_getgr.cc
@@ -8,9 +8,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <string>
 
-std::string any_group;
+std::unique_ptr<char []> any_group;
 const int N = 123456;
 
 void Check(const char *str) {
@@ -48,8 +47,11 @@
   assert(result->gr_gid != N);
   for (char **mem = result->gr_mem; *mem; ++mem)
     Check(*mem);
-  if (any_group.empty())
-    any_group = result->gr_name;
+  if (!any_group) {
+    auto length = strlen(result->gr_name);
+    any_group.reset(new char[length + 1]);
+    memcpy(any_group.get(), result->gr_name, length + 1);
+  }
 }
 
 template <class T, class Fn, class... Args>
@@ -72,7 +74,7 @@
   test<passwd>(&getpwuid, 0);
   test<passwd>(&getpwnam, "root");
   test<group>(&getgrgid, 0);
-  test<group>(&getgrnam, any_group.c_str());
+  test<group>(&getgrnam, any_group.get());
 
 #if !defined(__ANDROID__)
   setpwent();
@@ -91,7 +93,7 @@
   test_r<passwd>(&getpwnam_r, "root");
 
   test_r<group>(&getgrgid_r, 0);
-  test_r<group>(&getgrnam_r, any_group.c_str());
+  test_r<group>(&getgrnam_r, any_group.get());
 
 #if defined(__linux__)
   auto pwd_file = [] {