On Sun, 24 May 2020 at 00:15, Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote: > > Instead of using efi_gdt64 to switch back to 64-bit mode and then > switching to the real boot-time GDT, just switch to the boot-time GDT > directly. The two GDT's are identical other than efi_gdt64 not including > the 32-bit code segment. > > Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx> Queued, thanks. > --- > arch/x86/boot/compressed/efi_thunk_64.S | 19 +++---------------- > 1 file changed, 3 insertions(+), 16 deletions(-) > > diff --git a/arch/x86/boot/compressed/efi_thunk_64.S b/arch/x86/boot/compressed/efi_thunk_64.S > index 2b2049259619..c4bb0f9363f5 100644 > --- a/arch/x86/boot/compressed/efi_thunk_64.S > +++ b/arch/x86/boot/compressed/efi_thunk_64.S > @@ -28,8 +28,6 @@ SYM_FUNC_START(__efi64_thunk) > push %rbx > > leaq 1f(%rip), %rbp > - leaq efi_gdt64(%rip), %rbx > - movl %ebx, 2(%rbx) /* Fixup the gdt base address */ > > movl %ds, %eax > push %rax > @@ -48,7 +46,8 @@ SYM_FUNC_START(__efi64_thunk) > movl %r8d, 0xc(%rsp) > movl %r9d, 0x10(%rsp) > > - sgdt 0x14(%rsp) > + leaq 0x14(%rsp), %rbx > + sgdt (%rbx) > > /* > * Switch to gdt with 32-bit segments. This is the firmware GDT > @@ -68,8 +67,7 @@ SYM_FUNC_START(__efi64_thunk) > pushq %rax > lretq > > -1: lgdt 0x14(%rsp) > - addq $32, %rsp > +1: addq $32, %rsp > movq %rdi, %rax > > pop %rbx > @@ -175,14 +173,3 @@ SYM_DATA_END(efi32_boot_cs) > SYM_DATA_START(efi32_boot_ds) > .word 0 > SYM_DATA_END(efi32_boot_ds) > - > -SYM_DATA_START(efi_gdt64) > - .word efi_gdt64_end - efi_gdt64 > - .long 0 /* Filled out by user */ > - .word 0 > - .quad 0x0000000000000000 /* NULL descriptor */ > - .quad 0x00af9a000000ffff /* __KERNEL_CS */ > - .quad 0x00cf92000000ffff /* __KERNEL_DS */ > - .quad 0x0080890000000000 /* TS descriptor */ > - .quad 0x0000000000000000 /* TS continued */ > -SYM_DATA_END_LABEL(efi_gdt64, SYM_L_LOCAL, efi_gdt64_end) > -- > 2.26.2 >
