efi/libstub: Annotate firmware routines as __efiapi
Annotate all the firmware routines (boot services, runtime services and
protocol methods) called in the boot context as __efiapi, and make
it expand to __attribute__((ms_abi)) on 64-bit x86. This allows us
to use the compiler to generate the calls into firmware that use the
MS calling convention instead of the SysV one.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Borislav Petkov <bp@alien8.de>
Cc: James Morse <james.morse@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20191224151025.32482-13-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5e89499..ded73bb 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1991,11 +1991,12 @@
platforms.
config EFI_STUB
- bool "EFI stub support"
- depends on EFI && !X86_USE_3DNOW
- select RELOCATABLE
- ---help---
- This kernel feature allows a bzImage to be loaded directly
+ bool "EFI stub support"
+ depends on EFI && !X86_USE_3DNOW
+ depends on $(cc-option,-mabi=ms) || X86_32
+ select RELOCATABLE
+ ---help---
+ This kernel feature allows a bzImage to be loaded directly
by EFI firmware without the use of a bootloader.
See Documentation/admin-guide/efi-stub.rst for more information.