static void
instrument_post_write(void *drcontext, instrlist_t *ilist, instr_t *where, opnd_t memref,
instr_t *write, reg_id_t reg_addr)
{
reg_id_t reg_ptr;
ushort stride = (ushort)drutil_opnd_mem_size_in_bytes(memref, write);
/* We want to use the same predicate as write when inserting the following
* instrumentation.
*/
instrlist_set_auto_predicate(ilist, instr_get_predicate(write));
if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_ptr) !=
DRREG_SUCCESS) {
DR_ASSERT(false);
return;
}
drx_buf_insert_load_buf_ptr(drcontext, write_buffer, ilist, where, reg_ptr);
/* drx_buf_insert_buf_memcpy() internally updates the buffer pointer */
drx_buf_insert_buf_memcpy(drcontext, write_buffer, ilist, where, reg_ptr, reg_addr,
stride);
if (drreg_unreserve_register(drcontext, ilist, where, reg_ptr) != DRREG_SUCCESS)
DR_ASSERT(false);
if (drreg_unreserve_register(drcontext, ilist, where, reg_addr) != DRREG_SUCCESS)
DR_ASSERT(false);
/* Set the predicate back to the default */
instrlist_set_auto_predicate(ilist, instr_get_predicate(where));
}
/* insert inline code to add an instruction entry into the buffer */
static void
instrument_instr(void *drcontext, instrlist_t *ilist, instr_t *where)
{
/* We need two scratch registers */
reg_id_t reg_ptr, reg_tmp;
/* we don't want to predicate this, because an instruction fetch always occurs */
instrlist_set_auto_predicate(ilist, DR_PRED_NONE);
if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_ptr) !=
DRREG_SUCCESS ||
drreg_reserve_register(drcontext, ilist, where, NULL, ®_tmp) !=
DRREG_SUCCESS) {
DR_ASSERT(false); /* cannot recover */
return;
}
insert_load_buf_ptr(drcontext, ilist, where, reg_ptr);
insert_save_type(drcontext, ilist, where, reg_ptr, reg_tmp,
(ushort)instr_get_opcode(where));
insert_save_size(drcontext, ilist, where, reg_ptr, reg_tmp,
(ushort)instr_length(drcontext, where));
insert_save_pc(drcontext, ilist, where, reg_ptr, reg_tmp, instr_get_app_pc(where));
insert_update_buf_ptr(drcontext, ilist, where, reg_ptr, sizeof(mem_ref_t));
/* Restore scratch registers */
if (drreg_unreserve_register(drcontext, ilist, where, reg_ptr) != DRREG_SUCCESS ||
drreg_unreserve_register(drcontext, ilist, where, reg_tmp) != DRREG_SUCCESS)
DR_ASSERT(false);
instrlist_set_auto_predicate(ilist, instr_get_predicate(where));
}
bool
instr_is_ubr_arch(instr_t *instr)
{
int opc = instr->opcode; /* caller ensures opcode is valid */
if (opc == OP_b || opc == OP_b_short) {
dr_pred_type_t pred = instr_get_predicate(instr);
return (pred == DR_PRED_NONE || pred == DR_PRED_AL);
}
return false;
}
bool
instr_is_cbr_arch(instr_t *instr)
{
int opc = instr->opcode; /* caller ensures opcode is valid */
if (opc == OP_cbnz || opc == OP_cbz)
return true;
/* We don't consider a predicated indirect branch to be a cbr */
if (opc == OP_b || opc == OP_b_short ||
/* Yes, conditional calls are considered cbr */
opc == OP_bl || opc == OP_blx) {
dr_pred_type_t pred = instr_get_predicate(instr);
return (pred != DR_PRED_NONE && pred != DR_PRED_AL);
}
/* XXX: should OP_it be considered a cbr? */
return false;
}