6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ard Biesheuvel <ardb@xxxxxxxxxx> commit 630f337f0c4fd80390e8600adcab31550aea33df upstream. Tweak the asm and remove some redundant instructions. While at it, fix the associated comment for style and correctness. Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lore.kernel.org/r/20221122161017.2426828-9-ardb@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/boot/compressed/efi_mixed.S | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) --- a/arch/x86/boot/compressed/efi_mixed.S +++ b/arch/x86/boot/compressed/efi_mixed.S @@ -96,24 +96,20 @@ SYM_FUNC_START(__efi64_thunk) leaq 0x20(%rsp), %rbx sgdt (%rbx) - - addq $16, %rbx - sidt (%rbx) + sidt 16(%rbx) leaq 1f(%rip), %rbp /* - * Switch to IDT and GDT with 32-bit segments. This is the firmware GDT - * and IDT that was installed when the kernel started executing. The - * pointers were saved by the efi32_entry() routine below. + * Switch to IDT and GDT with 32-bit segments. These are the firmware + * GDT and IDT that were installed when the kernel started executing. + * The pointers were saved by the efi32_entry() routine below. * * Pass the saved DS selector to the 32-bit code, and use far return to * restore the saved CS selector. */ - leaq efi32_boot_idt(%rip), %rax - lidt (%rax) - leaq efi32_boot_gdt(%rip), %rax - lgdt (%rax) + lidt efi32_boot_idt(%rip) + lgdt efi32_boot_gdt(%rip) movzwl efi32_boot_ds(%rip), %edx movzwq efi32_boot_cs(%rip), %rax @@ -187,9 +183,7 @@ SYM_FUNC_START_LOCAL(efi_enter32) */ cli - lidtl (%ebx) - subl $16, %ebx - + lidtl 16(%ebx) lgdtl (%ebx) movl %cr4, %eax
