Date: Tue, 19 Sep 2006 20:32:54 -0700 From: Pete Zaitcev <zaitcev@redhat.com> Subject: [RHEL5 patch] Add uevent to ccw on s390 This patch actually changes existing uevent support to contain MODALIAS. Bug #199994. Although it seems incredible that anything would work with this bug at all, we did not notice it for a while, because initrd always loads all that you need, then networking loads with /etc/module.conf. I forgot to ask Bill what he did to hit it, maybe used nameif. Anyway, it seems like a patch we obviously should have. I tested that it works, and looked it over for sanity (e.g. blatant overflows after sprintf). This is not in Linus' tree as of 2.6.18-rc7, and wasn't even sent yet. But I think it shouldn't be a problem. IBMers have this patch registered. If it were Fedora, I'd hold until IBM posted it properly, but Bill says he needs this now. Please ack. -- Pete --- linux-2.6.17-1.2519.4.26.el5/drivers/s390/cio/device.c 2006-09-19 18:44:44.000000000 -0400 +++ linux-2.6.17-1.2519.4.26.el5.t1/drivers/s390/cio/device.c 2006-09-19 22:28:23.000000000 -0400 @@ -52,53 +52,81 @@ ccw_bus_match (struct device * dev, stru return 1; } -/* - * Hotplugging interface for ccw devices. - * Heavily modeled on pci and usb hotplug. - */ -static int -ccw_uevent (struct device *dev, char **envp, int num_envp, - char *buffer, int buffer_size) +/* Store modalias string delimited by prefix/suffix string into buffer with + * specified size. Return length of resulting string (excluding trailing '\0') + * even if string doesn't fit buffer (snprintf semantics). */ +static int snprint_alias(char *buf, size_t size, const char *prefix, + struct ccw_device_id *id, const char *suffix) +{ + int len; + + len = snprintf(buf, size, "%sccw:t%04Xm%02X", prefix, id->cu_type, + id->cu_model); + if (len > size) + return len; + buf += len; + size -= len; + + if (id->dev_type != 0) + len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type, + id->dev_model, suffix); + else + len += snprintf(buf, size, "dtdm%s", suffix); + + return len; +} + +/* Set up environment variables for ccw device uevent. Return 0 on success, + * non-zero otherwise. */ +static int ccw_uevent(struct device *dev, char **envp, int num_envp, + char *buffer, int buffer_size) { struct ccw_device *cdev = to_ccwdev(dev); + struct ccw_device_id *id = &(cdev->id); int i = 0; - int length = 0; + int len; - if (!cdev) - return -ENODEV; - - /* what we want to pass to /sbin/hotplug */ - - envp[i++] = buffer; - length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X", - cdev->id.cu_type); - if ((buffer_size - length <= 0) || (i >= num_envp)) + /* CU_TYPE= */ + len = snprintf(buffer, buffer_size, "CU_TYPE=%04X", id->cu_type) + 1; + if (len > buffer_size || i >= num_envp) return -ENOMEM; - ++length; - buffer += length; - envp[i++] = buffer; - length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X", - cdev->id.cu_model); - if ((buffer_size - length <= 0) || (i >= num_envp)) + buffer += len; + buffer_size -= len; + + /* CU_MODEL= */ + len = snprintf(buffer, buffer_size, "CU_MODEL=%02X", id->cu_model) + 1; + if (len > buffer_size || i >= num_envp) return -ENOMEM; - ++length; - buffer += length; + envp[i++] = buffer; + buffer += len; + buffer_size -= len; /* The next two can be zero, that's ok for us */ - envp[i++] = buffer; - length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X", - cdev->id.dev_type); - if ((buffer_size - length <= 0) || (i >= num_envp)) + /* DEV_TYPE= */ + len = snprintf(buffer, buffer_size, "DEV_TYPE=%04X", id->dev_type) + 1; + if (len > buffer_size || i >= num_envp) return -ENOMEM; - ++length; - buffer += length; + envp[i++] = buffer; + buffer += len; + buffer_size -= len; + /* DEV_MODEL= */ + len = snprintf(buffer, buffer_size, "DEV_MODEL=%02X", + (unsigned char) id->dev_model) + 1; + if (len > buffer_size || i >= num_envp) + return -ENOMEM; envp[i++] = buffer; - length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X", - cdev->id.dev_model); - if ((buffer_size - length <= 0) || (i >= num_envp)) + buffer += len; + buffer_size -= len; + + /* MODALIAS= */ + len = snprint_alias(buffer, buffer_size, "MODALIAS=", id, "") + 1; + if (len > buffer_size || i >= num_envp) return -ENOMEM; + envp[i++] = buffer; + buffer += len; + buffer_size -= len; envp[i] = NULL; @@ -251,16 +279,11 @@ modalias_show (struct device *dev, struc { struct ccw_device *cdev = to_ccwdev(dev); struct ccw_device_id *id = &(cdev->id); - int ret; + int len; - ret = sprintf(buf, "ccw:t%04Xm%02X", - id->cu_type, id->cu_model); - if (id->dev_type != 0) - ret += sprintf(buf + ret, "dt%04Xdm%02X\n", - id->dev_type, id->dev_model); - else - ret += sprintf(buf + ret, "dtdm\n"); - return ret; + len = snprint_alias(buf, PAGE_SIZE, "", id, "\n") + 1; + + return len > PAGE_SIZE ? PAGE_SIZE : len; } static ssize_t