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

Message ID 20230206124938.272988-1-ardb@kernel.org (mailing list archive)
Headers show
Series efi: Enable BTI for EFI runtimes services | expand

Message

Ard Biesheuvel Feb. 6, 2023, 12:49 p.m. UTC
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@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>

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(-)

Comments

Ard Biesheuvel Feb. 8, 2023, 12:35 p.m. UTC | #1
On Mon, 6 Feb 2023 at 13:49, Ard Biesheuvel <ardb@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@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Dave Hansen <dave.hansen@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
>