void
offline_instru_t::insert_save_addr(void *drcontext, instrlist_t *ilist, instr_t *where,
reg_id_t reg_ptr, reg_id_t reg_addr, int adjust,
opnd_t ref)
{
bool ok;
int disp = adjust;
if (opnd_uses_reg(ref, reg_ptr))
drreg_get_app_value(drcontext, ilist, where, reg_ptr, reg_ptr);
if (opnd_uses_reg(ref, reg_addr))
drreg_get_app_value(drcontext, ilist, where, reg_addr, reg_addr);
// We use reg_ptr as scratch to get the address.
ok = drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg_addr, reg_ptr);
DR_ASSERT(ok);
// drutil_insert_get_mem_addr may clobber reg_ptr, so we need to re-load reg_ptr.
// XXX i#2001: determine whether we have to and avoid it when we don't.
insert_load_buf_ptr(drcontext, ilist, where, reg_ptr);
MINSERT(ilist, where,
XINST_CREATE_store(drcontext,
OPND_CREATE_MEMPTR(reg_ptr, disp),
opnd_create_reg(reg_addr)));
// We allow either 0 or all 1's as the type so no need to write anything else.
}
static reg_id_t
instrument_mem(void *drcontext, instrlist_t *ilist, instr_t *where, opnd_t ref)
{
reg_id_t reg_ptr, reg_tmp, reg_addr;
ushort type, size;
bool ok;
if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_tmp) !=
DRREG_SUCCESS) {
DR_ASSERT(false);
return DR_REG_NULL;
}
if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_ptr) !=
DRREG_SUCCESS) {
DR_ASSERT(false);
return DR_REG_NULL;
}
/* i#2449: In the situation that instrument_post_write, instrument_mem and ref all
* have the same register reserved, drutil_insert_get_mem_addr will compute the
* address of an operand using an incorrect register value, as drreg will elide the
* save/restore.
*/
if (opnd_uses_reg(ref, reg_tmp) &&
drreg_get_app_value(drcontext, ilist, where, reg_tmp, reg_tmp) != DRREG_SUCCESS) {
DR_ASSERT(false);
return DR_REG_NULL;
}
if (opnd_uses_reg(ref, reg_ptr) &&
drreg_get_app_value(drcontext, ilist, where, reg_ptr, reg_ptr) != DRREG_SUCCESS) {
DR_ASSERT(false);
return DR_REG_NULL;
}
/* We use reg_ptr as scratch to get addr. Note we do this first as reg_ptr or reg_tmp
* may be used in ref.
*/
ok = drutil_insert_get_mem_addr(drcontext, ilist, where, ref, reg_tmp, reg_ptr);
DR_ASSERT(ok);
drx_buf_insert_load_buf_ptr(drcontext, trace_buffer, ilist, where, reg_ptr);
/* inserts memref addr */
drx_buf_insert_buf_store(drcontext, trace_buffer, ilist, where, reg_ptr, DR_REG_NULL,
opnd_create_reg(reg_tmp), OPSZ_PTR,
offsetof(mem_ref_t, addr));
if (IF_AARCHXX_ELSE(true, false)) {
/* At this point we save the write address for later, because reg_tmp's value
* will get clobbered on ARM.
*/
if (drreg_reserve_register(drcontext, ilist, where, NULL, ®_addr) !=
DRREG_SUCCESS) {
DR_ASSERT(false);
return DR_REG_NULL;
}
MINSERT(ilist, where,
XINST_CREATE_move(drcontext, opnd_create_reg(reg_addr),
opnd_create_reg(reg_tmp)));
}
/* inserts type */
type = (ushort)instr_get_opcode(where);
drx_buf_insert_buf_store(drcontext, trace_buffer, ilist, where, reg_ptr, reg_tmp,
OPND_CREATE_INT16(type), OPSZ_2, offsetof(mem_ref_t, type));
/* inserts size */
size = (ushort)drutil_opnd_mem_size_in_bytes(ref, where);
drx_buf_insert_buf_store(drcontext, trace_buffer, ilist, where, reg_ptr, reg_tmp,
OPND_CREATE_INT16(size), OPSZ_2, offsetof(mem_ref_t, size));
drx_buf_insert_update_buf_ptr(drcontext, trace_buffer, ilist, where, reg_ptr,
DR_REG_NULL, sizeof(mem_ref_t));
if (instr_is_call(where)) {
app_pc pc;
/* Note that on ARM the call instruction writes only to the link register, so
* we would never even get into instrument_mem() on ARM if this was a call.
*/
IF_AARCHXX(DR_ASSERT(false));
/* We simulate the call instruction's written memory by writing the next app_pc
* to the written buffer, since we can't do this after the call has happened.
*/
drx_buf_insert_load_buf_ptr(drcontext, write_buffer, ilist, where, reg_ptr);
pc = decode_next_pc(drcontext, instr_get_app_pc(where));
/* note that for a circular buffer, we don't need to specify a scratch register */
drx_buf_insert_buf_store(drcontext, trace_buffer, ilist, where, reg_ptr,
DR_REG_NULL, OPND_CREATE_INTPTR((ptr_int_t)pc), OPSZ_PTR,
0);
drx_buf_insert_update_buf_ptr(drcontext, write_buffer, ilist, where, reg_ptr,
reg_tmp, sizeof(app_pc));
/* we don't need to persist reg_tmp to the next instruction */
if (drreg_unreserve_register(drcontext, ilist, where, reg_tmp) != DRREG_SUCCESS)
DR_ASSERT(false);
reg_tmp = DR_REG_NULL;
} else if (IF_AARCHXX_ELSE(true, false)) {
/* Now reg_tmp has the address of the write again. */
MINSERT(ilist, where,
XINST_CREATE_move(drcontext, opnd_create_reg(reg_tmp),
opnd_create_reg(reg_addr)));
if (drreg_unreserve_register(drcontext, ilist, where, reg_addr) != DRREG_SUCCESS)
DR_ASSERT(false);
}
if (drreg_unreserve_register(drcontext, ilist, where, reg_ptr) != DRREG_SUCCESS)
DR_ASSERT(false);
return reg_tmp;
}
