[MIPS] Restore the trusted stack in NaClSyscallSeg.

src/trusted/service_runtime/arch/mips/sel_rt.c

 /*
- * Copyright 2012 The Native Client Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can
- * be found in the LICENSE file.
+ * Copyright (c) 2012 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
  */
 
 /*
  * NaCl Secure Runtime
  */
 #include "native_client/src/include/portability_string.h"
 #include "native_client/src/trusted/service_runtime/nacl_signal.h"
 #include "native_client/src/trusted/service_runtime/sel_ldr.h"
 #include "native_client/src/trusted/service_runtime/sel_rt.h"
 #include "native_client/src/trusted/service_runtime/arch/mips/sel_ldr_mips.h"
@@ skipping 68 matching lines @@
   sig_ctx->s2          = th_ctx->s2;
   sig_ctx->s3          = th_ctx->s3;
   sig_ctx->s4          = th_ctx->s4;
   sig_ctx->s5          = th_ctx->s5;
   sig_ctx->s6          = th_ctx->s6;
   sig_ctx->s7          = th_ctx->s7;
   sig_ctx->t8          = th_ctx->t8;
   sig_ctx->t9          = 0;
   sig_ctx->k0          = 0;
   sig_ctx->k1          = 0;
-  sig_ctx->global_ptr  = th_ctx->global_ptr;
+  sig_ctx->global_ptr  = 0;
   sig_ctx->stack_ptr   = th_ctx->stack_ptr;
   sig_ctx->frame_ptr   = th_ctx->frame_ptr;
   sig_ctx->return_addr = th_ctx->prog_ctr;
 }