1                 : /*
       2                 :  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
       3                 :  * Use of this source code is governed by a BSD-style license that can be
       4                 :  * found in the LICENSE file.
       5                 :  */
       6                 : 
       7                 : /* Implement the functions common for ia32 and x86-64 architectures.  */
       8                 : #include "native_client/src/trusted/validator_ragel/dfa_validate_common.h"
       9                 : 
      10                 : #include <string.h>
      11                 : 
      12                 : #include "native_client/src/shared/platform/nacl_check.h"
      13                 : #include "native_client/src/trusted/service_runtime/nacl_config.h"
      14                 : #include "native_client/src/trusted/validator_ragel/validator.h"
      15                 : 
      16                 : /* Used as an argument to copy_func when unsupported instruction must be
      17                 :    replaced with HLTs.  */
      18                 : static const uint8_t kStubOutMem[MAX_INSTRUCTION_LENGTH] = {
      19                 :   NACL_HALT_OPCODE, NACL_HALT_OPCODE, NACL_HALT_OPCODE, NACL_HALT_OPCODE,
      20                 :   NACL_HALT_OPCODE, NACL_HALT_OPCODE, NACL_HALT_OPCODE, NACL_HALT_OPCODE,
      21                 :   NACL_HALT_OPCODE, NACL_HALT_OPCODE, NACL_HALT_OPCODE, NACL_HALT_OPCODE,
      22                 :   NACL_HALT_OPCODE, NACL_HALT_OPCODE, NACL_HALT_OPCODE, NACL_HALT_OPCODE,
      23                 :   NACL_HALT_OPCODE
      24                 : };
      25                 : 
      26               0 : Bool NaClDfaProcessValidationError(const uint8_t *begin, const uint8_t *end,
      27               0 :                                    uint32_t info, void *callback_data) {
      28               0 :   UNREFERENCED_PARAMETER(begin);
      29               0 :   UNREFERENCED_PARAMETER(end);
      30               0 :   UNREFERENCED_PARAMETER(info);
      31               0 :   UNREFERENCED_PARAMETER(callback_data);
      32                 : 
      33               0 :   return FALSE;
      34                 : }
      35                 : 
      36              59 : Bool NaClDfaStubOutCPUUnsupportedInstruction(const uint8_t *begin,
      37              59 :                                              const uint8_t *end,
      38              59 :                                              uint32_t info,
      39              59 :                                              void *callback_data) {
      40                 :   /* Stub-out instructions unsupported on this CPU, but valid on other CPUs.  */
      41              59 :   if ((info & VALIDATION_ERRORS_MASK) == CPUID_UNSUPPORTED_INSTRUCTION) {
      42               1 :     int *did_stubout = callback_data;
      43               1 :     *did_stubout = 1;
      44               3 :     memset((uint8_t *)begin, NACL_HALT_OPCODE, end - begin);
      45               1 :     return TRUE;
      46                 :   } else {
      47              58 :     return FALSE;
      48                 :   }
      49              59 : }
      50                 : 
      51             159 : Bool NaClDfaProcessCodeCopyInstruction(const uint8_t *begin_new,
      52             159 :                                        const uint8_t *end_new,
      53             159 :                                        uint32_t info_new,
      54             159 :                                        void *callback_data) {
      55             159 :   struct CodeCopyCallbackData *data = callback_data;
      56             159 :   size_t instruction_length = end_new - begin_new;
      57                 : 
      58                 :   /* Sanity check: instruction must be no longer than 17 bytes.  */
      59             477 :   CHECK(instruction_length <= MAX_INSTRUCTION_LENGTH);
      60                 : 
      61             477 :   return data->copy_func(
      62                 :       (uint8_t *)begin_new + data->existing_minus_new, /* begin_existing */
      63                 :       (info_new & VALIDATION_ERRORS_MASK) == CPUID_UNSUPPORTED_INSTRUCTION ?
      64                 :         (uint8_t *)kStubOutMem :
      65                 :         (uint8_t *)begin_new,
      66                 :       (uint8_t)instruction_length);
      67                 : }
      68                 : 
      69               0 : Bool NaClDfaCodeReplacementIsStubouted(const uint8_t *begin_existing,
      70               0 :                                        size_t instruction_length) {
      71                 : 
      72                 :   /* Unsupported instruction must have been replaced with HLTs.  */
      73               0 :   if (memcmp(kStubOutMem, begin_existing, instruction_length) == 0)
      74               0 :     return TRUE;
      75                 :   else
      76               0 :     return FALSE;
      77               0 : }