Add some stuff that got missed along the way:
- CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y so SCS vs PAC is hardware
selectable.
- CONFIG_X86_KERNEL_IBT=y while a default, just be sure.
- CONFIG_CFI_CLANG=y globally.
- CONFIG_PAGE_TABLE_CHECK=y for userspace mapping sanity.
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240501193709.make.982-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Inspired by Salvatore Mesoraca's earlier[1] efforts to provide some
in-tree guidance for kernel hardening Kconfig options, add a new fragment
named "hardening-basic.config" (along with some arch-specific fragments)
that enable a basic set of kernel hardening options that have the least
(or no) performance impact and remove a reasonable set of legacy APIs.
Using this fragment is as simple as running "make hardening.config".
More extreme fragments can be added[2] in the future to cover all the
recognized hardening options, and more per-architecture files can be
added too.
For now, document the fragments directly via comments. Perhaps .rst
documentation can be generated from them in the future (rather than the
other way around).
[1] https://lore.kernel.org/kernel-hardening/1536516257-30871-1-git-send-email-s.mesoraca16@gmail.com/
[2] https://github.com/KSPP/linux/issues/14
Cc: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Cc: x86@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
