On Mon, Feb 14, 2022 at 08:45:52PM +0100, Arnd Bergmann wrote:
As Al pointed out, they turned out to be necessary on sparc64, but the only definitions are on sparc64 and x86, so it's possible that they serve a similar purpose here, in which case changing the limit from TASK_SIZE to TASK_SIZE_MAX is probably wrong as well. So either I need to revert the original definition as I did on sparc64, or they can be removed completely. Hopefully Al or the x86 maintainers can clarify.
Looking at the x86 users I think: - valid_user_frame should go away and the caller should use get_user instead of __get_user - the one in copy_code can just go away, as there is another check in copy_from_user_nmi - copy_stack_frame should just use access_ok - as does copy_from_user_nmi but yes, having someone who actually knows this code look over it would be very helpful.
