[PATCH v2 0/2] efi: preserve NEON registers on UEFI services calls

[ard.biesheuvel@linaro.org (Ard Biesheuvel)]

The current UEFI implementation for arm64 fails to preserve/restore the contents
of the NEON register file, which may result in data corruption, especially now
that those contents are lazily restored for user processes.

This series proposes to fix this by wrapping all runtime services calls, and
adding kernel_neon_begin()/kernel_neon_end() pairs to the wrappers.

The first patch moves the existing x86 versions of those wrappers to generic
code, so that the second patch can easily enable them by supplying a definition
for efi_call_virt and adding a call to efi_native_runtime_setup().

Changes since v1:
- rename runtime.c -> runtime-wrappers.c
- make build depend on new Kconfig symbol EFI_RUNTIME_WRAPPERS to fix ia64
  breakage
- remove default #defines for efi_call_virt()/__efi_call_virt(), they are not
  needed anymore now that it is built conditionally
- add references to applicable UEFI/AAPCS spec sections

Ard Biesheuvel (2):
  efi/x86: move UEFI Runtime Services wrappers to generic code
  efi/arm64: preserve FP/SIMD registers on UEFI runtime services calls

 arch/arm64/Kconfig                      |   1 +
 arch/arm64/include/asm/efi.h            |  21 +++++
 arch/arm64/kernel/efi.c                 |  14 +--
 arch/x86/Kconfig                        |   1 +
 arch/x86/platform/efi/efi.c             | 144 +---------------------------
 drivers/firmware/efi/Kconfig            |   7 ++
 drivers/firmware/efi/Makefile           |   1 +
 drivers/firmware/efi/runtime-wrappers.c | 161 ++++++++++++++++++++++++++++++++
 include/linux/efi.h                     |   2 +
 9 files changed, 197 insertions(+), 155 deletions(-)
 create mode 100644 drivers/firmware/efi/runtime-wrappers.c

-- 
1.8.3.2