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[0/2] arm64: Expose kernel code size to EFI zboot code

Message ID 20230426141103.2464423-1-ardb@kernel.org (mailing list archive)
Headers show
Series arm64: Expose kernel code size to EFI zboot code | expand

Message

Ard Biesheuvel April 26, 2023, 2:11 p.m. UTC 
The EFI zboot code needs access to the kernel code size, in order to be
able to determine which part of the image needs to be cleaned to the
PoU, and does not tolerate being mapped with non-executable permissions.

Instead of adding [0] this to the kernel image header, which makes it
ABI, let's use Kbuild rules to inject this quantity into the zboot
payload ELF object.

[0] https://lore.kernel.org/all/20230418134952.1170141-1-ardb@kernel.org/

Ard Biesheuvel (2):
  efi/zboot: arm64: Inject kernel code size symbol into the zboot
    payload
  efi/zboot: arm64: Grab kernel code size from zboot payload

 arch/arm64/boot/Makefile                    |  3 +++
 arch/arm64/kernel/image-vars.h              |  4 ++++
 drivers/firmware/efi/libstub/Makefile.zboot | 16 ++++------------
 drivers/firmware/efi/libstub/arm64.c        | 19 +++++++++++++------
 drivers/firmware/efi/libstub/efistub.h      |  3 +--
 drivers/firmware/efi/libstub/zboot.c        | 15 ++++-----------
 drivers/firmware/efi/libstub/zboot.lds      |  7 +++++++
 7 files changed, 36 insertions(+), 31 deletions(-)