On Mon, Dec 19, 2022 at 04:15:32PM +0800, Chao Peng wrote: > Tamping down with error number a bit: > > if (attrs->flags) > return -ENXIO; > if (attrs->attributes & ~supported_attrs) > return -EOPNOTSUPP; > if (!PAGE_ALIGNED(attrs->address) || !PAGE_ALIGNED(attrs->size) || > attrs->size == 0) > return -EINVAL; > if (attrs->address + attrs->size < attrs->address) > return -E2BIG; Yap, better. I guess you should add those to the documentation of the ioctl too so that people can find out why it fails. Or, well, they can look at the code directly too but still... imagine some blurb about user-friendliness here... :-) -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette