@@ -139,12 +139,11 @@ SYM_FUNC_START(startup_32)
/*
* The GDT may get overwritten either during the copy we just did or
* during extract_kernel below. To avoid any issues, repoint the GDTR
- * to the new copy of the GDT. EAX still contains the previously
- * calculated relocation offset of init_size - _end.
+ * to the new copy of the GDT.
*/
- leal gdt(%ebx), %edx
- addl %eax, 2(%edx)
- lgdt (%edx)
+ leal gdt(%ebx), %eax
+ movl %eax, 2(%eax)
+ lgdt (%eax)
/*
* Jump to the relocated address.
@@ -456,8 +456,8 @@ trampoline_return:
* to the new copy of the GDT.
*/
leaq gdt64(%rbx), %rax
- subq %rbp, 2(%rax)
- addq %rbx, 2(%rax)
+ leaq gdt(%rbx), %rdx
+ movq %rdx, 2(%rax)
lgdt (%rax)
/*
Commit ef5a7b5eb13e ("efi/x86: Remove GDT setup from efi_main") introduced GDT setup into the 32-bit kernel's startup_32, and reloads the GDTR after relocating the kernel for paranoia's sake. Commit 32d009137a56 ("x86/boot: Reload GDTR after copying to the end of the buffer") introduced a similar GDTR reload in the 64-bit kernel. The GDTR is adjusted by init_size - _end, however this may not be the correct offset to apply if the kernel was loaded at a misaligned address or below LOAD_PHYSICAL_ADDR, as in that case the decompression buffer has an additional offset from the original load address. This should never happen for a conformant bootloader, but we're being paranoid anyway, so just store the new GDT address in there instead of adding any offsets, which is simpler as well. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Fixes: ef5a7b5eb13e ("efi/x86: Remove GDT setup from efi_main") Fixes: 32d009137a56 ("x86/boot: Reload GDTR after copying to the end of the buffer") --- arch/x86/boot/compressed/head_32.S | 9 ++++----- arch/x86/boot/compressed/head_64.S | 4 ++-- 2 files changed, 6 insertions(+), 7 deletions(-)