Re: [PATCH v3 0/3] arm64: Add CONFIG_KUSER_HELPERS

[Kees Cook]

On Mon, Sep 11, 2017 at 8:26 AM, Mark Salyzyn <salyzyn@xxxxxxxxxxx> wrote:
> Make it possible to disable the kuser helpers by adding a KUSER_HELPERS
> config option (enabled by default). When disabled, all kuser
> helpers-related code is removed from the kernel and no mapping is done
> at the fixed high address (0xffff0000); any attempt to use a kuser
> helper from a 32-bit process will result in a segfault.
>
> Signed-off-by: Mark Salyzyn <salyzyn@xxxxxxxxxxx>
>
> v2:
> - vectors_page and compat_vdso_spec as array of 2
> - free sigpage if vectors allocation failed
> - adjust makefile so one line for each of the assembler source modules
> - split off assembler changes to a new previous patch in series to reduce churn
> - modify slightly the feature documentation to reduce its reach
> - modify slightly the feature documentation to rationalize the yes default.
> - There are more ifdefs as a result of the rebase.
>
> v3:
> - rebase (minor conflicts)

This looks great to me. I'd love to see kuser helpers gone. :)

Catalin, Will, does this need anything else?

-Kees

-- 
Kees Cook
Pixel Security