Hello Tomasz Nowicki,
The patch 4bf2efd26d76: "ACPI: Add new IORT functions to support MSI
domain handling" from Sep 12, 2016, leads to the following static
checker warning:
drivers/acpi/arm64/iort.c:628 iort_dev_find_its_id()
warn: array off by one? 'its->identifiers[idx]'
drivers/acpi/arm64/iort.c
589 /**
590 * iort_dev_find_its_id() - Find the ITS identifier for a device
591 * @dev: The device.
592 * @req_id: Device's requester ID
593 * @idx: Index of the ITS identifier list.
594 * @its_id: ITS identifier.
595 *
596 * Returns: 0 on success, appropriate error value otherwise
597 */
598 static int iort_dev_find_its_id(struct device *dev, u32 req_id,
599 unsigned int idx, int *its_id)
600 {
601 struct acpi_iort_its_group *its;
602 struct acpi_iort_node *node;
603
604 node = iort_find_dev_node(dev);
605 if (!node)
606 return -ENXIO;
607
608 node = iort_node_map_id(node, req_id, NULL, IORT_MSI_TYPE);
609 if (!node)
610 return -ENXIO;
611
612 /* Move to ITS specific data */
613 its = (struct acpi_iort_its_group *)node->node_data;
614 if (idx > its->its_count) {
^^^^^^^^^^^^^^^^^^^^
I wasn't able to find any information about how its->its_count is set
but it looks to me that is off by one.
615 dev_err(dev, "requested ITS ID index [%d] is greater than available [%d]\n",
616 idx, its->its_count);
617 return -ENXIO;
618 }
619
620 *its_id = its->identifiers[idx];
621 return 0;
622 }
regards,
dan carpenter
