Hi, On Wed, Jul 04, 2018 at 02:30:32PM +0900, Chanwoo Choi wrote: > I didn't see any framework which exporting the class instance. > It is very dangerous. Unknown device drivers is able to reset > the 'devfreq_class' instance. I can't agree this approach. While I agree that it is potential dangerous it is actually a common practice to export the class: grep "extern struct class " include/linux/ -R include/linux/rio.h:extern struct class rio_mport_class; include/linux/tty.h:extern struct class *tty_class; include/linux/fb.h:extern struct class *fb_class; include/linux/ide.h:extern struct class *ide_port_class; include/linux/device.h:extern struct class * __must_check __class_create(struct module *owner, include/linux/devfreq.h:extern struct class *devfreq_class; include/linux/switchtec.h:extern struct class *switchtec_class; include/linux/input.h:extern struct class input_class; include/linux/genhd.h:extern struct class block_class; include/linux/power_supply.h:extern struct class *power_supply_class; include/linux/rtc.h:extern struct class *rtc_class; struct class_interface and class_interface_register() would be pointless without exported classes. My understanding is that the kernel is often lax on encapsulation and exposes private/delicate data pragmatically within the kernel when needed because "the kernel trusts itself". Thanks Matthias -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
