On Wed, Jan 19, 2022 at 12:02:34PM +0100, Janis Schoetterl-Glausch wrote: > > That's a lot of code churn... I would have expected that the existing > > functions will be renamed, get an additional key parameter, and the > > current API is implemented by defines which map copy_to_user() & > > friends to the new functions, and add a zero key. > > I don't think I understand you. I can implement raw_copy_from/to_user > in terms of raw_copy_from/to_user_with_key, which does save a few lines, > but that's it, isn't it? Right you are. I only looked at your patch, and forgot about that all the wrapping is nowadays done in common code. So what I really don't like about this approach is that we get an arch specific copy_to_user() implementation back. This means that all those extra calls like might_fault(), instrument_copy_to_user(), and friends now have to be kept in sync by us again, if new instrumentation or security options are added to common code. Given that this is manual work / monitoring I'm sure this will not work in the mid or long term, like it has been proven several times in the past for other features. We need something better, which works out-of-the-box wrt common code changes / enhancements.
