On Sun, Jul 4, 2021 at 2:47 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > > How about the following ? > > WARN_ON_ONCE(IS_ENABLED(CONFIG_MMU) && uaccess_kernel()); Nope, that doesn't work either, because there are no-MMU setups that don't make the same mistake no-mmu arm and m68k do. Example: xtensa. But afaik also generic-asm/uaccess.h unless the architecture overrides something. So this literally seems like just an arm/m68k bug. Linus