From ebiederm@xmission.com Tue Sep 21 14:08:44 2010 From: Eric W. Biederman To: Greg Kroah-Hartman Cc: "Hans J. Koch" Date: Tue, 14 Sep 2010 11:38:36 -0700 Message-ID: Subject: uio: Statically allocate uio_class and use class .dev_attrs. Instead of adding uio class attributes manually after the uio device has been created and we have sent a uevent to userspace, use the class attribute mechanism. This removes races and makes the code simpler. At the same time don't bother to dynamically allocate a struct class for uio, just declare one statically. Less code is needed and it is easier to set the class parameters.tune the class Signed-off-by: Eric W. Biederman Reviewed-by: Thomas Gleixner Signed-off-by: Hans J. Koch Signed-off-by: Greg Kroah-Hartman --- drivers/uio/uio.c | 53 ++++++++++++++++++----------------------------------- 1 file changed, 18 insertions(+), 35 deletions(-) --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -46,9 +46,6 @@ static struct cdev *uio_cdev; static DEFINE_IDR(uio_idr); static const struct file_operations uio_fops; -/* UIO class infrastructure */ -static struct class *uio_class; - /* Protect idr accesses */ static DEFINE_MUTEX(minor_lock); @@ -233,7 +230,6 @@ static ssize_t show_name(struct device * struct uio_device *idev = dev_get_drvdata(dev); return sprintf(buf, "%s\n", idev->info->name); } -static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); static ssize_t show_version(struct device *dev, struct device_attribute *attr, char *buf) @@ -241,7 +237,6 @@ static ssize_t show_version(struct devic struct uio_device *idev = dev_get_drvdata(dev); return sprintf(buf, "%s\n", idev->info->version); } -static DEVICE_ATTR(version, S_IRUGO, show_version, NULL); static ssize_t show_event(struct device *dev, struct device_attribute *attr, char *buf) @@ -249,17 +244,18 @@ static ssize_t show_event(struct device struct uio_device *idev = dev_get_drvdata(dev); return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); } -static DEVICE_ATTR(event, S_IRUGO, show_event, NULL); -static struct attribute *uio_attrs[] = { - &dev_attr_name.attr, - &dev_attr_version.attr, - &dev_attr_event.attr, - NULL, +static struct device_attribute uio_class_attributes[] = { + __ATTR(name, S_IRUGO, show_name, NULL), + __ATTR(version, S_IRUGO, show_version, NULL), + __ATTR(event, S_IRUGO, show_event, NULL), + {} }; -static struct attribute_group uio_attr_grp = { - .attrs = uio_attrs, +/* UIO class infrastructure */ +static struct class uio_class = { + .name = "uio", + .dev_attrs = uio_class_attributes, }; /* @@ -276,10 +272,6 @@ static int uio_dev_add_attributes(struct struct uio_port *port; struct uio_portio *portio; - ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp); - if (ret) - goto err_group; - for (mi = 0; mi < MAX_UIO_MAPS; mi++) { mem = &idev->info->mem[mi]; if (mem->size == 0) @@ -347,8 +339,6 @@ err_map: kobject_put(&map->kobj); } kobject_put(idev->map_dir); - sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); -err_group: dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); return ret; } @@ -374,8 +364,6 @@ static void uio_dev_del_attributes(struc kobject_put(&port->portio->kobj); } kobject_put(idev->portio_dir); - - sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp); } static int uio_get_minor(struct uio_device *idev) @@ -775,7 +763,6 @@ static void uio_major_cleanup(void) static int init_uio_class(void) { - struct class *class; int ret; /* This is the first time in here, set everything up properly */ @@ -783,16 +770,14 @@ static int init_uio_class(void) if (ret) goto exit; - class = class_create(THIS_MODULE, "uio"); - if (IS_ERR(class)) { - ret = IS_ERR(class); - printk(KERN_ERR "class_create failed for uio\n"); - goto err_class_create; + ret = class_register(&uio_class); + if (ret) { + printk(KERN_ERR "class_register failed for uio\n"); + goto err_class_register; } - uio_class = class; return 0; -err_class_create: +err_class_register: uio_major_cleanup(); exit: return ret; @@ -800,9 +785,7 @@ exit: static void release_uio_class(void) { - /* Ok, we cheat as we know we only have one uio_class */ - class_destroy(uio_class); - uio_class = NULL; + class_unregister(&uio_class); uio_major_cleanup(); } @@ -841,7 +824,7 @@ int __uio_register_device(struct module if (ret) goto err_get_minor; - idev->dev = device_create(uio_class, parent, + idev->dev = device_create(&uio_class, parent, MKDEV(uio_major, idev->minor), idev, "uio%d", idev->minor); if (IS_ERR(idev->dev)) { @@ -868,7 +851,7 @@ int __uio_register_device(struct module err_request_irq: uio_dev_del_attributes(idev); err_uio_dev_add_attributes: - device_destroy(uio_class, MKDEV(uio_major, idev->minor)); + device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); err_device_create: uio_free_minor(idev); err_get_minor: @@ -899,7 +882,7 @@ void uio_unregister_device(struct uio_in uio_dev_del_attributes(idev); - device_destroy(uio_class, MKDEV(uio_major, idev->minor)); + device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); kfree(idev); return;