[PATCH v2 0/3] efi: Enable BTI for EFI runtimes services

[Ard Biesheuvel]

On Mon, 6 Feb 2023 at 13:49, Ard Biesheuvel <ardb at kernel.org> wrote:
>
> The EFI spec v2.10 introduces a global flag in the memory attributes
> table that indicates whether the EFI runtime code regions were emitted
> with BTI landing pads, and can therefore tolerate being mapped with BTI
> enforcement enabled.
>
> Add the generic plumbing for this, and wire it up for arm64.
>
> Changes since v1:
> - enable BTI in UEFI code regions even if CONFIG_ARM64_BIT_KERNEL=n
> - deal with BTI exceptions occuring in EFI code gracefully
> - add equivalent handling to x86
> - add Kees's R-b
>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: Kees Cook <keescook at chromium.org>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Peter Zijlstra <peterz at infradead.org>
> Cc: Thomas Gleixner <tglx at linutronix.de>
> Cc: Ingo Molnar <mingo at redhat.com>
> Cc: Borislav Petkov <bp at alien8.de>
> Cc: Dave Hansen <dave.hansen at linux.intel.com>
>

x86, arm64 maintainers: I'd like to queue these up in the EFI tree.
Any objections?



> Ard Biesheuvel (3):
>   efi: Discover BTI support in runtime services regions
>   efi: arm64: Wire up BTI annotation in memory attributes table
>   efi: x86: Wire up IBT annotation in memory attributes table
>
>  arch/arm/include/asm/efi.h     |  2 +-
>  arch/arm/kernel/efi.c          |  5 +++--
>  arch/arm64/include/asm/efi.h   |  3 ++-
>  arch/arm64/kernel/efi.c        | 17 ++++++++++++++---
>  arch/arm64/kernel/traps.c      |  6 ++++++
>  arch/riscv/include/asm/efi.h   |  2 +-
>  arch/riscv/kernel/efi.c        |  3 ++-
>  arch/x86/include/asm/efi.h     |  4 +++-
>  arch/x86/include/asm/ibt.h     |  4 ++--
>  arch/x86/kernel/apm_32.c       |  4 ++--
>  arch/x86/kernel/cpu/common.c   |  5 +++--
>  arch/x86/platform/efi/efi_64.c |  8 +++++++-
>  drivers/firmware/efi/memattr.c |  7 ++++++-
>  include/linux/efi.h            |  8 ++++++--
>  14 files changed, 58 insertions(+), 20 deletions(-)
>
> --
> 2.39.1
>