service_runtime/sel_rt.c

   1 /*
   2  * Copyright 2008, Google Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  *     * Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *     * Redistributions in binary form must reproduce the above
  12  * copyright notice, this list of conditions and the following disclaimer
  13  * in the documentation and/or other materials provided with the
  14  * distribution.
  15  *     * Neither the name of Google Inc. nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * NaCl Secure Runtime
  34  */
  35
  36 #include "native_client/service_runtime/sel_ldr.h"
  37 #include "native_client/service_runtime/sel_rt.h"
  38 #include "native_client/service_runtime/nacl_ldt.h"
  39
  40 int NaClThreadContextCtor(struct NaClThreadContext  *ntcp,
  41                           uintptr_t                 eip,
  42                           uintptr_t                 esp,
  43                           uint16_t                  des_seg,
  44                           uint16_t                  gs,
  45                           uint16_t                  cs)
  46 {
  47   /*
  48    * initialize registers to appropriate values.  most registers just
  49    * get zero, but for the segment register we allocate segment
  50    * selectors for the NaCl app, based on its address space.
  51    */
  52   ntcp->ebx = 0;
  53   ntcp->esi = 0;
  54   ntcp->edi = 0;
  55   ntcp->ebp = 0;
  56   ntcp->esp = esp;
  57   ntcp->eip = eip;
  58
  59   ntcp->cs = cs;
  60   ntcp->ds = des_seg;
  61
  62   ntcp->es = des_seg;
  63   ntcp->fs = 0;  /* windows use this for TLS and SEH; linux does not */
  64   ntcp->gs = gs;
  65   ntcp->ss = des_seg;
  66
  67   return 1;
  68 }