firewire: core: check for missing struct update at build time, not run time

struct fw_attribute_group.attrs.[] must have enough room for all
attributes.  This can and should be checked at build time.

Our previous check at run time was a little late and not reliable since
most of the time less than the available attributes are populated.

Furthermore, omit an increment of an index at its last usage.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index a38a68b..98ce084 100644 (file)
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -292,8 +292,7 @@ static void init_fw_attribute_group(struct device *dev,
                group->attrs[j++] = &attr->attr;
        }
 
-       BUG_ON(j >= ARRAY_SIZE(group->attrs));
-       group->attrs[j++] = NULL;
+       group->attrs[j] = NULL;
        group->groups[0] = &group->group;
        group->groups[1] = NULL;
        group->group.attrs = group->attrs;
@@ -570,9 +569,13 @@ static void create_units(struct fw_device *device)
                unit->device.parent = &device->device;
                dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
 
+               BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
+                               ARRAY_SIZE(fw_unit_attributes) +
+                               ARRAY_SIZE(config_rom_attributes));
                init_fw_attribute_group(&unit->device,
                                        fw_unit_attributes,
                                        &unit->attribute_group);
+
                if (device_register(&unit->device) < 0)
                        goto skip_unit;
 
@@ -849,9 +852,13 @@ static void fw_device_init(struct work_struct *work)
        device->device.devt = MKDEV(fw_cdev_major, minor);
        dev_set_name(&device->device, "fw%d", minor);
 
+       BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
+                       ARRAY_SIZE(fw_device_attributes) +
+                       ARRAY_SIZE(config_rom_attributes));
        init_fw_attribute_group(&device->device,
                                fw_device_attributes,
                                &device->attribute_group);
+
        if (device_add(&device->device)) {
                fw_error("Failed to add device.\n");
                goto error_with_cdev;