Re: [PATCH] fs/proc/kcore.c: Omit kernel text area for hardened usercopy feature

[Linus Torvalds]

On Wed, Sep 7, 2016 at 10:17 AM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> !DEVKMEM is easy to represent, but STRICT_DEVMEM=y gets a little ugly,

I think you can just do

   config STRICT_DEVMEM
        bool "Filter access to /dev/mem" if !HARDENED_USERCOPY
        depends on MMU
        depends on ARCH_HAS_DEVMEM_IS_ALLOWED
        default y

ie you put the "if !HARDENED_USERCOPY" on the *question*, so that if
HARDENED_USERCOPY is set you'll never actually ask it.

Or you just make it go the other way, and make HARDENED_USERCOPY
depend on STRICT_DEVMEM.

                  Linus