Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
@@ -104,15 +104,21 @@
   return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
 # elif defined(__mips64)
   return (1ULL << 40) - 1;  // 0x000000ffffffffffUL;
+# elif defined(__s390x__)
+  return (1ULL << 53) - 1;  // 0x001fffffffffffffUL;
 # else
   return (1ULL << 47) - 1;  // 0x00007fffffffffffUL;
 # endif
 #else  // SANITIZER_WORDSIZE == 32
+# if defined(__s390__)
+  return (1ULL << 31) - 1;  // 0x7fffffff;
+# else
   uptr res = (1ULL << 32) - 1;  // 0xffffffff;
   if (!common_flags()->full_address_space)
     res -= GetKernelAreaSize();
   CHECK_LT(reinterpret_cast<uptr>(&res), res);
   return res;
+# endif
 #endif  // SANITIZER_WORDSIZE
 }
 
Index: compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
+++ compiler-rt/trunk/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
@@ -42,6 +42,10 @@
 static const u64 kAddressSpaceSize = 1ULL << 40;
 #elif defined(__aarch64__)
 static const u64 kAddressSpaceSize = 1ULL << 39;
+#elif defined(__s390x__)
+static const u64 kAddressSpaceSize = 1ULL << 53;
+#elif defined(__s390__)
+static const u64 kAddressSpaceSize = 1ULL << 31;
 #else
 static const u64 kAddressSpaceSize = 1ULL << 32;
 #endif