[PATCH v3 0/3] add ima_arch support for ARM64

[Chester Lin]

Add IMA arch dependent support for ARM64. Some IMA functions can check
arch-specific status before running. For example, the ima_load_data
function or the boot param "ima_appraise=" should not be executed when
UEFI secure boot is enabled. We want to fill the gap in order to complete
the IMA support on ARM64.

Changes in v3:
- Generalize efi_get_secureboot() so both ima_arch and efistub can reuse
  it.
- Implement ima_get_efi_secureboot() as the replacement of get_sb_mode()
  so x86 and arm64 can share the same logic.

Changes in v2:
- Separate get_sb_mode() from x86 so all EFI-based architectures can reuse
  the same function.
- Refactor arch/arm64/kernel/ima_arch.c based on Ard's patch[1].

Test platforms:
- ARM64:  QEMU [aarch64-virt] + EDK2/OVMF
- ARM64:  NXP LX2160A-RDB + EDK2
- X86_64: Dell Lattitude 7490 + (BIOS 1.14.0 01/22/2020)

[1] https://www.spinics.net/lists/linux-efi/msg20645.html

Chester Lin (3):
  efi: generalize efi_get_secureboot
  ima: remove get_sb_mode() and create ima_get_efi_secureboot()
  arm64/ima: add ima_arch support

 arch/arm64/Kconfig                        |  1 +
 arch/arm64/kernel/Makefile                |  2 +
 arch/arm64/kernel/ima_arch.c              | 43 +++++++++++++
 arch/x86/kernel/ima_arch.c                | 69 +++++---------------
 drivers/firmware/efi/libstub/Makefile     |  2 +-
 drivers/firmware/efi/libstub/efi-stub.c   |  2 +-
 drivers/firmware/efi/libstub/efistub.h    | 22 ++++---
 drivers/firmware/efi/libstub/secureboot.c | 76 -----------------------
 drivers/firmware/efi/libstub/x86-stub.c   |  2 +-
 include/linux/efi.h                       | 41 +++++++++++-
 include/linux/ima.h                       | 10 +++
 security/integrity/ima/Makefile           |  1 +
 security/integrity/ima/ima_efi.c          | 26 ++++++++
 13 files changed, 154 insertions(+), 143 deletions(-)
 create mode 100644 arch/arm64/kernel/ima_arch.c
 delete mode 100644 drivers/firmware/efi/libstub/secureboot.c
 create mode 100644 security/integrity/ima/ima_efi.c

-- 
2.28.0