linux/arch/x86/platform/efi/efi_stub_64.S
Arvind Sankar 14b864f4b5 efi/x86: Check number of arguments to variadic functions
On x86 we need to thunk through assembler stubs to call the EFI services
for mixed mode, and for runtime services in 64-bit mode. The assembler
stubs have limits on how many arguments it handles. Introduce a few
macros to check that we do not try to pass too many arguments to the
stubs.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Matthew Garrett <mjg59@google.com>
Cc: linux-efi@vger.kernel.org
Link: https://lkml.kernel.org/r/20200103113953.9571-16-ardb@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-01-10 18:55:04 +01:00

28 lines
524 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Function calling ABI conversion from Linux to EFI for x86_64
*
* Copyright (C) 2007 Intel Corp
* Bibo Mao <bibo.mao@intel.com>
* Huang Ying <ying.huang@intel.com>
*/
#include <linux/linkage.h>
#include <asm/nospec-branch.h>
SYM_FUNC_START(__efi_call)
pushq %rbp
movq %rsp, %rbp
and $~0xf, %rsp
mov 16(%rbp), %rax
subq $48, %rsp
mov %r9, 32(%rsp)
mov %rax, 40(%rsp)
mov %r8, %r9
mov %rcx, %r8
mov %rsi, %rcx
CALL_NOSPEC %rdi
leave
ret
SYM_FUNC_END(__efi_call)