diff options
| -rw-r--r-- | opcodes/i386-dis.c | 72 |
1 files changed, 59 insertions, 13 deletions
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c index d731175..393522f 100644 --- a/opcodes/i386-dis.c +++ b/opcodes/i386-dis.c @@ -329,6 +329,49 @@ fetch_data (struct disassemble_info *info, bfd_byte *addr) return 1; } +static bool +fetch_code (struct disassemble_info *info, bfd_byte *until) +{ + int status = -1; + struct dis_private *priv = info->private_data; + bfd_vma start = priv->insn_start + (priv->max_fetched - priv->the_buffer); + + if (until <= priv->max_fetched) + return true; + + if (until <= priv->the_buffer + MAX_MNEM_SIZE) + status = (*info->read_memory_func) (start, + priv->max_fetched, + until - priv->max_fetched, + info); + if (status != 0) + { + /* If we did manage to read at least one byte, then + print_insn_i386 will do something sensible. Otherwise, print + an error. We do that here because this is where we know + STATUS. */ + if (priv->max_fetched == priv->the_buffer) + (*info->memory_error_func) (status, start, info); + return false; + } + + priv->max_fetched = until; + return true; +} + +static bool +fetch_modrm (instr_info *ins) +{ + if (!fetch_code (ins->info, ins->codep + 1)) + return false; + + ins->modrm.mod = (*ins->codep >> 6) & 3; + ins->modrm.reg = (*ins->codep >> 3) & 7; + ins->modrm.rm = *ins->codep & 7; + + return true; +} + static int fetch_error (const instr_info *ins) { @@ -9605,7 +9648,7 @@ get_valid_dis386 (const struct dis386 *dp, instr_info *ins) return get_valid_dis386 (dp, ins); } -static void +static bool get_sib (instr_info *ins, int sizeflag) { /* If modrm.mod == 3, operand must be register. */ @@ -9614,7 +9657,8 @@ get_sib (instr_info *ins, int sizeflag) && ins->modrm.mod != 3 && ins->modrm.rm == 4) { - FETCH_DATA (ins->info, ins->codep + 2); + if (!fetch_code (ins->info, ins->codep + 2)) + return false; ins->sib.index = (ins->codep[1] >> 3) & 7; ins->sib.scale = (ins->codep[1] >> 6) & 3; ins->sib.base = ins->codep[1] & 7; @@ -9622,6 +9666,8 @@ get_sib (instr_info *ins, int sizeflag) } else ins->has_sib = false; + + return true; } /* Like oappend (below), but S is a string starting with '%'. In @@ -9886,7 +9932,9 @@ print_insn (bfd_vma pc, disassemble_info *info, int intel_syntax) ins.insn_codep = ins.codep; - FETCH_DATA (info, ins.codep + 1); + if (!fetch_code (info, ins.codep + 1)) + return fetch_error (&ins); + ins.two_source_ops = (*ins.codep == 0x62) || (*ins.codep == 0xc8); if (((ins.prefixes & PREFIX_FWAIT) @@ -9906,7 +9954,8 @@ print_insn (bfd_vma pc, disassemble_info *info, int intel_syntax) unsigned char threebyte; ins.codep++; - FETCH_DATA (info, ins.codep + 1); + if (!fetch_code (info, ins.codep + 1)) + return fetch_error (&ins); threebyte = *ins.codep; dp = &dis386_twobyte[threebyte]; ins.need_modrm = twobyte_has_modrm[threebyte]; @@ -9929,17 +9978,13 @@ print_insn (bfd_vma pc, disassemble_info *info, int intel_syntax) sizeflag ^= DFLAG; ins.end_codep = ins.codep; - if (ins.need_modrm) - { - FETCH_DATA (info, ins.codep + 1); - ins.modrm.mod = (*ins.codep >> 6) & 3; - ins.modrm.reg = (*ins.codep >> 3) & 7; - ins.modrm.rm = *ins.codep & 7; - } + if (ins.need_modrm && !fetch_modrm (&ins)) + return fetch_error (&ins); if (dp->name == NULL && dp->op[0].bytemode == FLOATCODE) { - get_sib (&ins, sizeflag); + if (!get_sib (&ins, sizeflag)) + return fetch_error (&ins); dofloat (&ins, sizeflag); } else @@ -9947,7 +9992,8 @@ print_insn (bfd_vma pc, disassemble_info *info, int intel_syntax) dp = get_valid_dis386 (dp, &ins); if (dp != NULL && putop (&ins, dp->name, sizeflag) == 0) { - get_sib (&ins, sizeflag); + if (!get_sib (&ins, sizeflag)) + return fetch_error (&ins); for (i = 0; i < MAX_OPERANDS; ++i) { ins.obufp = ins.op_out[i]; |