diff options
Diffstat (limited to 'arch/x86/platform/efi/efi_thunk_64.S')
| -rw-r--r-- | arch/x86/platform/efi/efi_thunk_64.S | 34 |
1 files changed, 28 insertions, 6 deletions
diff --git a/arch/x86/platform/efi/efi_thunk_64.S b/arch/x86/platform/efi/efi_thunk_64.S index fd3dd1708eba..c4b1144f99f6 100644 --- a/arch/x86/platform/efi/efi_thunk_64.S +++ b/arch/x86/platform/efi/efi_thunk_64.S @@ -8,7 +8,7 @@ * The below thunking functions are only used after ExitBootServices() * has been called. This simplifies things considerably as compared with * the early EFI thunking because we can leave all the kernel state - * intact (GDT, IDT, etc) and simply invoke the the 32-bit EFI runtime + * intact (GDT, IDT, etc) and simply invoke the 32-bit EFI runtime * services from __KERNEL32_CS. This means we can continue to service * interrupts across an EFI mixed mode call. * @@ -20,12 +20,14 @@ */ #include <linux/linkage.h> +#include <linux/objtool.h> #include <asm/page_types.h> #include <asm/segment.h> .text .code64 -SYM_CODE_START(__efi64_thunk) +SYM_FUNC_START(__efi64_thunk) +STACK_FRAME_NON_STANDARD __efi64_thunk push %rbp push %rbx @@ -37,6 +39,17 @@ SYM_CODE_START(__efi64_thunk) push %rax /* + * Copy args passed via the stack + */ + subq $0x24, %rsp + movq 0x18(%rax), %rbp + movq 0x20(%rax), %rbx + movq 0x28(%rax), %rax + movl %ebp, 0x18(%rsp) + movl %ebx, 0x1c(%rsp) + movl %eax, 0x20(%rsp) + + /* * Calculate the physical address of the kernel text. */ movq $__START_KERNEL_map, %rax @@ -47,7 +60,6 @@ SYM_CODE_START(__efi64_thunk) subq %rax, %rbp subq %rax, %rbx - subq $28, %rsp movl %ebx, 0x0(%rsp) /* return address */ movl %esi, 0x4(%rsp) movl %edx, 0x8(%rsp) @@ -60,16 +72,26 @@ SYM_CODE_START(__efi64_thunk) pushq %rdi /* EFI runtime service address */ lretq -1: movq 24(%rsp), %rsp + // This return instruction is not needed for correctness, as it will + // never be reached. It only exists to make objtool happy, which will + // otherwise complain about unreachable instructions in the callers. + RET +SYM_FUNC_END(__efi64_thunk) + + .section ".rodata", "a", @progbits + .balign 16 +SYM_DATA_START(__efi64_thunk_ret_tramp) +1: movq 0x20(%rsp), %rsp pop %rbx pop %rbp - retq + ret + int3 .code32 2: pushl $__KERNEL_CS pushl %ebp lret -SYM_CODE_END(__efi64_thunk) +SYM_DATA_END(__efi64_thunk_ret_tramp) .bss .balign 8 |