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@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> 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
