bool
instr_is_cti_short_rewrite(instr_t *instr, byte *pc)
{
/* We assume all app's cbz/cbnz have been mangled.
* See comments in x86/'s version of this routine.
*/
dcontext_t *dcontext;
dr_isa_mode_t old_mode;
if (pc == NULL) {
if (instr == NULL || !instr_has_allocated_bits(instr) ||
instr->length != CTI_SHORT_REWRITE_LENGTH)
return false;
pc = instr_get_raw_bits(instr);
}
if (instr != NULL && instr_opcode_valid(instr)) {
int opc = instr_get_opcode(instr);
if (opc != OP_cbz && opc != OP_cbnz)
return false;
}
if ((*(pc+1) != CBNZ_BYTE_A && *(pc+1) != CBZ_BYTE_A) ||
/* Further verify by checking for a disp of 1 */
(*pc & 0xf8) != 0x08)
return false;
/* XXX: this would be easier if decode_raw_is_jmp took in isa_mode */
dcontext = get_thread_private_dcontext();
if (instr != NULL)
dr_set_isa_mode(dcontext, instr_get_isa_mode(instr), &old_mode);
if (!decode_raw_is_jmp(dcontext, pc + CTI_SHORT_REWRITE_B_OFFS))
return false;
if (instr != NULL)
dr_set_isa_mode(dcontext, old_mode, NULL);
return true;
}
static dr_emit_flags_t
event_basic_block(void *drcontext, void *tag, instrlist_t *bb,
bool for_trace, bool translating)
{
instr_t *instr, *next_instr;
#ifdef VERBOSE
dr_printf("in dr_basic_block(tag="PFX")\n", tag);
# if VERBOSE_VERBOSE
instrlist_disassemble(drcontext, tag, bb, STDOUT);
# endif
#endif
for (instr = instrlist_first_app(bb); instr != NULL; instr = next_instr) {
next_instr = instr_get_next_app(instr);
if (!instr_opcode_valid(instr))
continue;
/* instrument calls and returns -- ignore far calls/rets */
if (instr_is_call_direct(instr)) {
dr_insert_call_instrumentation(drcontext, bb, instr, (app_pc)at_call);
} else if (instr_is_call_indirect(instr)) {
dr_insert_mbr_instrumentation(drcontext, bb, instr, (app_pc)at_call_ind,
SPILL_SLOT_1);
} else if (instr_is_return(instr)) {
dr_insert_mbr_instrumentation(drcontext, bb, instr, (app_pc)at_return,
SPILL_SLOT_1);
}
}
return DR_EMIT_DEFAULT;
}
