From: Johannes Berg > Sent: 09 October 2020 09:45 > > On Fri, 2020-10-09 at 08:34 +0000, David Laight wrote: > > ... > > Does it ever make any sense to set .owner to anything other than > > THIS_MODULE? > > No. But I believe THIS_MODULE is NULL for built-in code, so we can't > just WARN_ON(!fops->owner). ... > > I was also wondering if this affects normal opens? > > They should hold a reference on the module to stop it being unloaded. > > Does that rely on .owner being set? > > Yes. Sound like the module load code should be verifying it then. Looking at one of my modules (which does set .owner). Perhaps cdev_init() could be a #define that picks up THIS_MODULE. This could then be checked against the one in fops or saved in the 'struct cdev'. I presume debugfs (which I've not used) has some similar calls. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
