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; }