Joerg Roedel <joro@xxxxxxxxxx> writes: > + addq $8, %rsp > + > + /* > + * Make sure we return to __KERNEL_CS - the CS selector on > + * the IRET frame might still be from an old BIOS GDT > + */ > + movq $__KERNEL_CS, 8(%rsp) This doesn't make sense. Either it's running on the correct CS before the exception or not. Likely there's some other problem here that you patched over with this hack. -Andi