Hello Rafael J. Wysocki,
This is a semi-automatic email about new static checker warnings.
The patch a2b691772acd: "ACPI: EC: Avoid passing redundant argument
to functions" from Feb 27, 2020, leads to the following Smatch
complaint:
drivers/acpi/ec.c:1624 acpi_ec_add()
error: we previously assumed 'ec' could be null (see line 1595)
drivers/acpi/ec.c
1588
1589 strcpy(acpi_device_name(device), ACPI_EC_DEVICE_NAME);
1590 strcpy(acpi_device_class(device), ACPI_EC_CLASS);
1591
1592 if ((boot_ec && boot_ec->handle == device->handle) ||
^^^^^^^
Assume "boot_ec" is NULL.
1593 !strcmp(acpi_device_hid(device), ACPI_ECDT_HID)) {
And the strings math.
1594 /* Fast path: this device corresponds to the boot EC. */
1595 ec = boot_ec;
^^^^^^^^^^^^
so "ec" is NULL.
1596 } else {
1597 acpi_status status;
1598
1599 ec = acpi_ec_alloc();
1600 if (!ec)
1601 return -ENOMEM;
1602
1603 status = ec_parse_device(device->handle, 0, ec, NULL);
1604 if (status != AE_CTRL_TERMINATE) {
1605 ret = -EINVAL;
1606 goto err;
1607 }
1608
1609 if (boot_ec && ec->command_addr == boot_ec->command_addr &&
1610 ec->data_addr == boot_ec->data_addr) {
1611 /*
1612 * Trust PNP0C09 namespace location rather than
1613 * ECDT ID. But trust ECDT GPE rather than _GPE
1614 * because of ASUS quirks, so do not change
1615 * boot_ec->gpe to ec->gpe.
1616 */
1617 boot_ec->handle = ec->handle;
1618 acpi_handle_debug(ec->handle, "duplicated.\n");
1619 acpi_ec_free(ec);
1620 ec = boot_ec;
1621 }
1622 }
1623
1624 ret = acpi_ec_setup(ec, device);
^^
NULL dereference inside the function.
1625 if (ret)
1626 goto err;
regards,
dan carpenter
