Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_internal_defs.h
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_internal_defs.h
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_internal_defs.h
@@ -106,7 +106,12 @@
 #if (SANITIZER_WORDSIZE == 64) || SANITIZER_MAC
 typedef uptr operator_new_size_type;
 #else
+# if defined(__s390__) && !defined(__s390x__)
+// Special case: 31-bit s390 has unsigned long as size_t.
+typedef unsigned long operator_new_size_type;
+# else
 typedef u32 operator_new_size_type;
+# endif
 #endif
 
 
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_linux.cc
@@ -1339,6 +1339,15 @@
   *pc = ucontext->uc_mcontext.pc;
   *bp = ucontext->uc_mcontext.gregs[30];
   *sp = ucontext->uc_mcontext.gregs[29];
+#elif defined(__s390__)
+  ucontext_t *ucontext = (ucontext_t*)context;
+# if defined(__s390x__)
+  *pc = ucontext->uc_mcontext.psw.addr;
+# else
+  *pc = ucontext->uc_mcontext.psw.addr & 0x7fffffff;
+# endif
+  *bp = ucontext->uc_mcontext.gregs[11];
+  *sp = ucontext->uc_mcontext.gregs[15];
 #else
 # error "Unsupported arch"
 #endif
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_linux.cc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_linux.cc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_linux.cc
@@ -62,7 +62,7 @@
 }  // namespace __sanitizer
 
 #if !defined(__powerpc64__) && !defined(__x86_64__) && !defined(__aarch64__)\
-                            && !defined(__mips__)
+                            && !defined(__mips__) && !defined(__s390__)
 COMPILER_CHECK(struct___old_kernel_stat_sz == sizeof(struct __old_kernel_stat));
 #endif
 
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_posix.h
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_posix.h
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -81,6 +81,12 @@
                  SANITIZER_ANDROID ? FIRST_32_SECOND_64(104, 128) :
                                      FIRST_32_SECOND_64(144, 216);
   const unsigned struct_kernel_stat64_sz = 104;
+#elif defined(__s390__) && !defined(__s390x__)
+  const unsigned struct_kernel_stat_sz = 64;
+  const unsigned struct_kernel_stat64_sz = 104;
+#elif defined(__s390x__)
+  const unsigned struct_kernel_stat_sz = 144;
+  const unsigned struct_kernel_stat64_sz = 0;
 #endif
   struct __sanitizer_perf_event_attr {
     unsigned type;
@@ -101,7 +107,7 @@
 
 #if SANITIZER_LINUX || SANITIZER_FREEBSD
 
-#if defined(__powerpc64__)
+#if defined(__powerpc64__) || defined(__s390__)
   const unsigned struct___old_kernel_stat_sz = 0;
 #else
   const unsigned struct___old_kernel_stat_sz = 32;
@@ -188,7 +194,7 @@
     unsigned __seq;
     u64 __unused1;
     u64 __unused2;
-#elif defined(__mips__) || defined(__aarch64__)
+#elif defined(__mips__) || defined(__aarch64__) || defined(__s390x__)
     unsigned int mode;
     unsigned short __seq;
     unsigned short __pad1;
@@ -576,7 +582,11 @@
     int sa_flags;
     __sanitizer_sigset_t sa_mask;
 #else
+#if defined(__s390x__)
+    int sa_resv;
+#else
     __sanitizer_sigset_t sa_mask;
+#endif
 #ifndef __mips__
     int sa_flags;
 #endif
@@ -587,6 +597,9 @@
 #if defined(__mips__) && (SANITIZER_WORDSIZE == 32)
     int sa_resv[1];
 #endif
+#if defined(__s390x__)
+    __sanitizer_sigset_t sa_mask;
+#endif
   };
 #endif // !SANITIZER_ANDROID
 
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform_limits_posix.cc
@@ -1055,7 +1055,14 @@
 // Can't write checks for sa_handler and sa_sigaction due to them being
 // preprocessor macros.
 CHECK_STRUCT_SIZE_AND_OFFSET(sigaction, sa_mask);
+#ifndef __GLIBC_PREREQ
+#define __GLIBC_PREREQ(x, y) 0
+#endif
+#if !defined(__s390x__) || __GLIBC_PREREQ (2, 20)
+// On s390x glibc 2.19 and earlier sa_flags was unsigned long, and sa_resv
+// didn't exist.
 CHECK_STRUCT_SIZE_AND_OFFSET(sigaction, sa_flags);
+#endif
 #if SANITIZER_LINUX && (!SANITIZER_ANDROID || !SANITIZER_MIPS32)
 CHECK_STRUCT_SIZE_AND_OFFSET(sigaction, sa_restorer);
 #endif
@@ -1127,9 +1134,6 @@
 CHECK_SIZE_AND_OFFSET(ipc_perm, gid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, cuid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, cgid);
-#ifndef __GLIBC_PREREQ
-#define __GLIBC_PREREQ(x, y) 0
-#endif
 #if !defined(__aarch64__) || !SANITIZER_LINUX || __GLIBC_PREREQ (2, 21)
 /* On aarch64 glibc 2.20 and earlier provided incorrect mode field.  */
 CHECK_SIZE_AND_OFFSET(ipc_perm, mode);