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x86: properly reset prefixPresent for prefix0/1 group

This commit is contained in:
Nguyen Anh Quynh 2014-06-20 11:15:58 +08:00
parent dab17fd0b1
commit eb2f3fb85a
1 changed files with 63 additions and 24 deletions
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87
arch/X86/X86DisassemblerDecoder.c
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@ -423,42 +423,81 @@ static int readPrefixes(struct InternalInstruction* insn)
switch (byte) {
case 0xf2: /* REPNE/REPNZ */
case 0xf3: /* REP or REPE/REPZ */
case 0xf0: /* LOCK */
// only accept the last prefix
insn->prefixPresent[0xf2] = 0;
insn->prefixPresent[0xf3] = 0;
case 0xf0: /* LOCK */
insn->prefixPresent[0xf0] = 0;
setPrefixPresent(insn, byte, prefixLocation);
insn->prefix0 = byte;
break;
case 0x2e: /* CS segment override -OR- Branch not taken */
insn->segmentOverride = SEG_OVERRIDE_CS;
// only accept the last prefix
insn->prefixPresent[0x2e] = 0;
insn->prefixPresent[0x36] = 0;
insn->prefixPresent[0x3e] = 0;
insn->prefixPresent[0x26] = 0;
insn->prefixPresent[0x64] = 0;
insn->prefixPresent[0x65] = 0;
setPrefixPresent(insn, byte, prefixLocation);
insn->prefix1 = byte;
break;
case 0x36: /* SS segment override -OR- Branch taken */
insn->segmentOverride = SEG_OVERRIDE_SS;
// only accept the last prefix
insn->prefixPresent[0x2e] = 0;
insn->prefixPresent[0x36] = 0;
insn->prefixPresent[0x3e] = 0;
insn->prefixPresent[0x26] = 0;
insn->prefixPresent[0x64] = 0;
insn->prefixPresent[0x65] = 0;
setPrefixPresent(insn, byte, prefixLocation);
insn->prefix1 = byte;
break;
case 0x3e: /* DS segment override */
insn->segmentOverride = SEG_OVERRIDE_DS;
// only accept the last prefix
insn->prefixPresent[0x2e] = 0;
insn->prefixPresent[0x36] = 0;
insn->prefixPresent[0x3e] = 0;
insn->prefixPresent[0x26] = 0;
insn->prefixPresent[0x64] = 0;
insn->prefixPresent[0x65] = 0;
setPrefixPresent(insn, byte, prefixLocation);
insn->prefix1 = byte;
break;
case 0x26: /* ES segment override */
insn->segmentOverride = SEG_OVERRIDE_ES;
// only accept the last prefix
insn->prefixPresent[0x2e] = 0;
insn->prefixPresent[0x36] = 0;
insn->prefixPresent[0x3e] = 0;
insn->prefixPresent[0x26] = 0;
insn->prefixPresent[0x64] = 0;
insn->prefixPresent[0x65] = 0;
setPrefixPresent(insn, byte, prefixLocation);
insn->prefix1 = byte;
break;
case 0x64: /* FS segment override */
insn->segmentOverride = SEG_OVERRIDE_FS;
// only accept the last prefix
insn->prefixPresent[0x2e] = 0;
insn->prefixPresent[0x36] = 0;
insn->prefixPresent[0x3e] = 0;
insn->prefixPresent[0x26] = 0;
insn->prefixPresent[0x64] = 0;
insn->prefixPresent[0x65] = 0;
setPrefixPresent(insn, byte, prefixLocation);
insn->prefix1 = byte;
break;
case 0x65: /* GS segment override */
switch (byte) {
case 0x2e:
insn->segmentOverride = SEG_OVERRIDE_CS;
break;
case 0x36:
insn->segmentOverride = SEG_OVERRIDE_SS;
break;
case 0x3e:
insn->segmentOverride = SEG_OVERRIDE_DS;
break;
case 0x26:
insn->segmentOverride = SEG_OVERRIDE_ES;
break;
case 0x64:
insn->segmentOverride = SEG_OVERRIDE_FS;
break;
case 0x65:
insn->segmentOverride = SEG_OVERRIDE_GS;
break;
default:
//debug("Unhandled override");
return -1;
}
insn->segmentOverride = SEG_OVERRIDE_GS;
// only accept the last prefix
insn->prefixPresent[0x2e] = 0;
insn->prefixPresent[0x36] = 0;