[PATCH v4 1/2] arm64: Support execute-only permissions with Enhanced PAN

[Will Deacon]

On Fri, Mar 12, 2021 at 05:38:10PM +0000, Vladimir Murzin wrote:
> Enhanced Privileged Access Never (EPAN) allows Privileged Access Never
> to be used with Execute-only mappings.
> 
> Absence of such support was a reason for 24cecc377463 ("arm64: Revert
> support for execute-only user mappings"). Thus now it can be revisited
> and re-enabled.
> 
> Cc: Kees Cook <keescook at chromium.org>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
> ---
>  arch/arm64/Kconfig                    | 17 +++++++++++++++
>  arch/arm64/include/asm/cpucaps.h      |  3 ++-
>  arch/arm64/include/asm/pgtable-prot.h |  5 +++--
>  arch/arm64/include/asm/pgtable.h      | 31 ++++++++++++++++++++-------
>  arch/arm64/include/asm/sysreg.h       |  3 ++-
>  arch/arm64/kernel/cpufeature.c        | 12 +++++++++++
>  arch/arm64/mm/fault.c                 | 18 +++++++++++++++-
>  mm/mmap.c                             |  6 ++++++
>  8 files changed, 82 insertions(+), 13 deletions(-)

Acked-by: Will Deacon <will at kernel.org>

Will