src/native_client/src/trusted/validator/x86/decoder/nc_inst_iter.c

   1 /*
   2  * Copyright (c) 2011 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 /*
   8  * Defines an instruction (decoder) iterator that processes code segments.
   9  */
  10
  11 #include "native_client/src/trusted/validator/x86/decoder/nc_inst_iter.h"
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15
  16 #include "native_client/src/shared/platform/nacl_log.h"
  17 #include "native_client/src/trusted/validator/x86/decoder/nc_inst_state.h"
  18 #include "native_client/src/trusted/validator/x86/decoder/nc_inst_state_internal.h"
  19 #include "native_client/src/trusted/validator/x86/decoder/nc_inst_trans.h"
  20 #include "native_client/src/trusted/validator/x86/decoder/ncop_exps.h"
  21
  22 /* To turn on debugging of instruction decoding, change value of
  23  * DEBUGGING to 1.
  24  */
  25 #define DEBUGGING 0
  26
  27 #include "native_client/src/shared/utils/debugging.h"
  28
  29 #include "native_client/src/trusted/validator/x86/decoder/nc_inst_iter_inl.c"
  30
  31 static void NaClInstIterLogError(const char* error_message) {
  32   NaClLog(LOG_ERROR, "*ERROR* %s\n", error_message);
  33 }
  34
  35 void NaClInstIterFatal(const char* error_message) {
  36   NaClInstIterLogError(error_message);
  37   exit(1);
  38 }
  39
  40 /* Default handler for errors found while parsing the memory segment.*/
  41 static void NaClInstIterReportRemainingMemoryError(
  42     NCRemainingMemoryError error,
  43     struct NCRemainingMemory* memory) {
  44   NaClInstIterLogError(NCRemainingMemoryErrorMessage(error));
  45 }
  46
  47 NaClInstIter* NaClInstIterCreateWithLookback(
  48     const struct NaClDecodeTables* decoder_tables,
  49     NaClSegment* segment,
  50     size_t lookback_size) {
  51   NaClInstIter* iter;
  52   /* Guarantee we don't wrap around while computing buffer index updates. */
  53   assert(((lookback_size + 1) * 2 + 1) > lookback_size);
  54   iter = (NaClInstIter*) malloc(sizeof(NaClInstIter));
  55   if (NULL != iter) {
  56     iter->segment = segment;
  57     NCRemainingMemoryInit(segment->mbase, segment->size, &iter->memory);
  58     iter->memory.error_fn = NaClInstIterReportRemainingMemoryError;
  59     iter->index = 0;
  60     iter->inst_count = 0;
  61     iter->buffer_size = lookback_size + 1;
  62     iter->buffer_index = 0;
  63     iter->buffer = (NaClInstState*)
  64         calloc(iter->buffer_size, sizeof iter->buffer[0]);
  65     if (NULL == iter->buffer) {
  66       free(iter);
  67       iter = NULL;
  68     } else {
  69       size_t i;
  70       for (i = 0; i < iter->buffer_size; ++i) {
  71         iter->buffer[i].inst = NULL;
  72         NCInstBytesInitMemory(&iter->buffer[i].bytes, &iter->memory);
  73       }
  74     }
  75   }
  76   iter->decoder_tables = (struct NaClDecodeTables*) decoder_tables;
  77   return iter;
  78 }
  79
  80 NaClInstIter* NaClInstIterCreate(
  81     const struct NaClDecodeTables* decoder_tables,
  82     NaClSegment* segment) {
  83   return NaClInstIterCreateWithLookback(decoder_tables, segment, 0);
  84 }
  85
  86 void NaClInstIterDestroy(NaClInstIter* iter) {
  87   if (NULL != iter) {
  88     free(iter->buffer);
  89     free(iter);
  90   }
  91 }
  92
  93 NaClInstState* NaClInstIterGetUndecodedState(NaClInstIter* iter) {
  94   return NaClInstIterGetUndecodedStateInline(iter);
  95 }
  96
  97 NaClInstState* NaClInstIterGetState(NaClInstIter* iter) {
  98   return NaClInstIterGetStateInline(iter);
  99 }
 100
 101 Bool NaClInstIterHasLookbackState(NaClInstIter* iter, size_t distance) {
 102   return NaClInstIterHasLookbackStateInline(iter, distance);
 103 }
 104
 105 NaClInstState* NaClInstIterGetLookbackState(NaClInstIter* iter,
 106                                             size_t distance) {
 107   return NaClInstIterGetLookbackStateInline(iter, distance);
 108 }
 109
 110 Bool NaClInstIterHasNext(NaClInstIter* iter) {
 111   return NaClInstIterHasNextInline(iter);
 112 }
 113
 114 void NaClInstIterAdvance(NaClInstIter* iter) {
 115   NaClInstIterAdvanceInline(iter);
 116 }
 117
 118 uint8_t* NaClInstIterGetInstMemory(NaClInstIter* iter) {
 119   return NaClInstIterGetInstMemoryInline(iter);
 120 }