[S390] handle incorrect values when writing to dasd sysfs attributes.

When writing to dasd attributes (e.g. readonly), all values besides '1'
are handled like '0'.
Other sysfs-attributes like 'online' are checking for '1' and for '0'
and do not accept other values. Therefore enhanced checking and error
handling in dasd_devmap attribute store functions.

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index 91cf971..b5e70c5 100644 (file)
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -684,21 +684,26 @@ dasd_ro_store(struct device *dev, struct device_attribute *attr,
              const char *buf, size_t count)
 {
        struct dasd_devmap *devmap;
-       int ro_flag;
+       int val;
+       char *endp;
 
        devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
        if (IS_ERR(devmap))
                return PTR_ERR(devmap);
-       ro_flag = buf[0] == '1';
+
+       val = simple_strtoul(buf, &endp, 0);
+       if (((endp + 1) < (buf + count)) || (val > 1))
+               return -EINVAL;
+
        spin_lock(&dasd_devmap_lock);
-       if (ro_flag)
+       if (val)
                devmap->features |= DASD_FEATURE_READONLY;
        else
                devmap->features &= ~DASD_FEATURE_READONLY;
        if (devmap->device)
                devmap->device->features = devmap->features;
        if (devmap->device && devmap->device->gdp)
-               set_disk_ro(devmap->device->gdp, ro_flag);
+               set_disk_ro(devmap->device->gdp, val);
        spin_unlock(&dasd_devmap_lock);
        return count;
 }
@@ -729,17 +734,22 @@ dasd_use_diag_store(struct device *dev, struct device_attribute *attr,
 {
        struct dasd_devmap *devmap;
        ssize_t rc;
-       int use_diag;
+       int val;
+       char *endp;
 
        devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
        if (IS_ERR(devmap))
                return PTR_ERR(devmap);
-       use_diag = buf[0] == '1';
+
+       val = simple_strtoul(buf, &endp, 0);
+       if (((endp + 1) < (buf + count)) || (val > 1))
+               return -EINVAL;
+
        spin_lock(&dasd_devmap_lock);
        /* Changing diag discipline flag is only allowed in offline state. */
        rc = count;
        if (!devmap->device) {
-               if (use_diag)
+               if (val)
                        devmap->features |= DASD_FEATURE_USEDIAG;
                else
                        devmap->features &= ~DASD_FEATURE_USEDIAG;
@@ -854,20 +864,25 @@ dasd_eer_store(struct device *dev, struct device_attribute *attr,
               const char *buf, size_t count)
 {
        struct dasd_devmap *devmap;
-       int rc;
+       int val, rc;
+       char *endp;
 
        devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
        if (IS_ERR(devmap))
                return PTR_ERR(devmap);
        if (!devmap->device)
-               return count;
-       if (buf[0] == '1') {
+               return -ENODEV;
+
+       val = simple_strtoul(buf, &endp, 0);
+       if (((endp + 1) < (buf + count)) || (val > 1))
+               return -EINVAL;
+
+       rc = count;
+       if (val)
                rc = dasd_eer_enable(devmap->device);
-               if (rc)
-                       return rc;
-       } else
+       else
                dasd_eer_disable(devmap->device);
-       return count;
+       return rc;
 }
 
 static DEVICE_ATTR(eer_enabled, 0644, dasd_eer_show, dasd_eer_store);