Hello Stephen Boyd,
The patch bd6f2fd5a1d5: "of: Support parsing phandle argument lists
through a nexus node" from Jan 30, 2018, leads to the following
static checker warning:
drivers/of/base.c:1592 of_parse_phandle_with_args_map()
warn: loop overwrites return value 'ret'
drivers/of/base.c
1590
1591 ret = -EINVAL;
^^^^^^^^^^^^^
This return is only used until part way through the first iteration.
For subsequent iterations, the code will return success in the case of
an error.
1592 while (cur) {
1593 /* Get the <list>-map property */
1594 map = of_get_property(cur, map_name, &map_len);
1595 if (!map) {
1596 ret = 0;
1597 goto free;
1598 }
1599 map_len /= sizeof(u32);
1600
1601 /* Get the <list>-map-mask property (optional) */
1602 mask = of_get_property(cur, mask_name, NULL);
1603 if (!mask)
1604 mask = dummy_mask;
1605 /* Iterate through <list>-map property */
1606 match = 0;
1607 while (map_len > (list_size + 1) && !match) {
1608 /* Compare specifiers */
1609 match = 1;
1610 for (i = 0; i < list_size; i++, map_len--)
1611 match &= !((match_array[i] ^ *map++) & mask[i]);
1612
1613 of_node_put(new);
1614 new = of_find_node_by_phandle(be32_to_cpup(map));
1615 map++;
1616 map_len--;
1617
1618 /* Check if not found */
1619 if (!new)
1620 goto put;
1621
1622 if (!of_device_is_available(new))
1623 match = 0;
1624
1625 ret = of_property_read_u32(new, cells_name, &new_size);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
"ret" set to zero here.
1626 if (ret)
1627 goto put;
1628
1629 /* Check for malformed properties */
1630 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1631 goto put;
^^^^^^^^
Probably -EINVAL was intended here.
1632 if (map_len < new_size)
1633 goto put;
1634
1635 /* Move forward by new node's #<list>-cells amount */
1636 map += new_size;
1637 map_len -= new_size;
1638 }
1639 if (!match)
1640 goto put;
1641
1642 /* Get the <list>-map-pass-thru property (optional) */
1643 pass = of_get_property(cur, pass_name, NULL);
1644 if (!pass)
1645 pass = dummy_pass;
1646
1647 /*
1648 * Successfully parsed a <list>-map translation; copy new
1649 * specifier into the out_args structure, keeping the
1650 * bits specified in <list>-map-pass-thru.
1651 */
1652 match_array = map - new_size;
1653 for (i = 0; i < new_size; i++) {
1654 __be32 val = *(map - new_size + i);
1655
1656 if (i < list_size) {
1657 val &= ~pass[i];
1658 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1659 }
1660
1661 out_args->args[i] = be32_to_cpu(val);
1662 }
1663 out_args->args_count = list_size = new_size;
1664 /* Iterate again with new provider */
1665 out_args->np = new;
1666 of_node_put(cur);
1667 cur = new;
1668 }
1669 put:
1670 of_node_put(cur);
1671 of_node_put(new);
1672 free:
1673 kfree(mask_name);
1674 kfree(map_name);
1675 kfree(cells_name);
1676 kfree(pass_name);
1677
1678 return ret;
1679 }
regards,
dan carpenter
