Virtualization
/
capstone
mirror of https://gitlab.com/qemu-project/capstone.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

x86: prefix REP/REPNE are only relevant for MOVS/CMPS/SCAS/LDOS/STOS/INS/OUTS instructions

This commit is contained in:
Nguyen Anh Quynh 2014-05-21 12:38:10 +08:00
parent 7a75baa679
commit 1d6f7ee50e
1 changed files with 111 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

140
arch/X86/X86Mapping.c
View File

@ -41779,10 +41779,69 @@ x86_reg X86_insn_reg(unsigned int id)
return 0;
}
// given MCInst's id, find out if this insn is valid for REP/REPNE prefix
static bool valid_rep(cs_struct *h, unsigned int opcode)
{
unsigned int id;
int i = insn_find(insns, ARR_SIZE(insns), opcode, &h->insn_cache);
if (i != 0) {
id = insns[i].mapid;
switch(id) {
default:
return false;
case X86_REP_MOVSB_32:
case X86_REP_MOVSW_32:
case X86_REP_MOVSD_32:
case X86_REP_MOVSB_64:
case X86_REP_MOVSD_64:
case X86_REP_MOVSQ_64:
case X86_REP_MOVSW_64:
case X86_INS_CMPSB:
case X86_INS_CMPSW:
case X86_INS_CMPSD:
case X86_INS_CMPSQ:
case X86_INS_SCASB:
case X86_INS_SCASW:
case X86_INS_SCASD:
case X86_INS_SCASQ:
case X86_INS_LODSB:
case X86_INS_LODSW:
case X86_INS_LODSD:
case X86_INS_LODSQ:
case X86_REP_STOSB_32:
case X86_REP_STOSD_32:
case X86_REP_STOSW_32:
case X86_REP_STOSB_64:
case X86_REP_STOSD_64:
case X86_REP_STOSQ_64:
case X86_REP_STOSW_64:
case X86_INS_INSB:
case X86_INS_INSW:
case X86_INS_INSD:
case X86_INS_OUTSB:
case X86_INS_OUTSW:
case X86_INS_OUTSD:
return true;
}
}
// not found
return false;
}
// return true if we patch the mnemonic
bool X86_lockrep(MCInst *MI, SStream *O)
{
int i;
#ifndef CAPSTONE_X86_REDUCE
unsigned int opcode;
#endif
if (MI->x86_lock_rep) {
for(i = 0; i < ARR_SIZE(MI->x86_prefix); i++) {
@ -41794,42 +41853,65 @@ bool X86_lockrep(MCInst *MI, SStream *O)
SStream_concat(O, "lock|");
#endif
break;
case 0xf2:
#ifndef CAPSTONE_X86_REDUCE
if (MCInst_getOpcode(MI) == X86_MULPDrr) {
MCInst_setOpcode(MI, X86_MULSDrr);
#ifndef CAPSTONE_DIET
SStream_concat(O, "mulsd\t");
#endif
MI->x86_prefix[i] = 0;
// notify that we already patched mnemonic
return true;
}
#ifndef CAPSTONE_DIET
else
case 0xf2: // repne
#ifndef CAPSTONE_DIET // only care about memonic in standard (non-diet) mode
opcode = MCInst_getOpcode(MI);
if (valid_rep(MI->csh, opcode)) {
SStream_concat(O, "repne|");
} else {
// invalid prefix
MI->x86_prefix[i] = 0;
// handle special cases
#ifndef CAPSTONE_X86_REDUCE
if (opcode == X86_MULPDrr) {
MCInst_setOpcode(MI, X86_MULSDrr);
SStream_concat(O, "mulsd\t");
return true;
}
#endif
}
#else // diet mode -> only patch opcode in special cases
if (!valid_rep(MI->csh, opcode)) {
MI->x86_prefix[i] = 0;
}
#ifndef CAPSTONE_X86_REDUCE
// handle special cases
if (opcode == X86_MULPDrr) {
MCInst_setOpcode(MI, X86_MULSDrr);
}
#endif
#else
SStream_concat(O, "repne|");
#endif
break;
case 0xf3:
#ifndef CAPSTONE_X86_REDUCE
if (MCInst_getOpcode(MI) == X86_MULPDrr) {
MCInst_setOpcode(MI, X86_MULSSrr);
#ifndef CAPSTONE_DIET
SStream_concat(O, "mulss\t");
#endif
MI->x86_prefix[i] = 0;
// notify that we already patched mnemonic
return true;
}
#ifndef CAPSTONE_DIET
else
#ifndef CAPSTONE_DIET // only care about memonic in standard (non-diet) mode
opcode = MCInst_getOpcode(MI);
if (valid_rep(MI->csh, opcode)) {
SStream_concat(O, "rep|");
} else {
// invalid prefix
MI->x86_prefix[i] = 0;
// handle special cases
#ifndef CAPSTONE_X86_REDUCE
if (opcode == X86_MULPDrr) {
MCInst_setOpcode(MI, X86_MULSSrr);
SStream_concat(O, "mulss\t");
return true;
}
#endif
}
#else // diet mode -> only patch opcode in special cases
if (!valid_rep(MI->csh, opcode)) {
MI->x86_prefix[i] = 0;
}
#ifndef CAPSTONE_X86_REDUCE
// handle special cases
if (opcode == X86_MULPDrr) {
MCInst_setOpcode(MI, X86_MULSSrr);
}
#endif
#else
SStream_concat(O, "rep|");
#endif
break;
}