On Tue, Feb 15, 2022 at 07:29:42AM +0100, Christoph Hellwig wrote: > On Tue, Feb 15, 2022 at 12:37:41AM +0000, Al Viro wrote: > > Perhaps simply wrap that sucker into #ifdef CONFIG_CPU_HAS_ADDRESS_SPACES > > (and trim the comment down to "coldfire and 68000 will pick generic > > variant")? > > I wonder if we should invert CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE, > select the separate address space config for s390, sparc64, non-coldfire > m68k and mips with EVA and then just have one single access_ok for > overlapping address space (as added by Arnd) and non-overlapping ones > (always return true). parisc is also such... How about select ALTERNATE_SPACE_USERLAND for that bunch? While we are at it, how many unusual access_ok() instances are left after this series? arm64, itanic, um, anything else? FWIW, sparc32 has a slightly unusual instance (see uaccess_32.h there); it's obviously cheaper than generic and I wonder if the trick is legitimate (and applicable elsewhere, perhaps)...
