On Thu, Mar 19, 2020 at 10:13:09AM +0100, Joerg Roedel wrote: > From: Joerg Roedel <jroedel@xxxxxxx> > > Add code needed to setup an IDT in the early pre-decompression > boot-code. The IDT is loaded first in startup_64, which is after > EfiExitBootServices() has been called, and later reloaded when the > kernel image has been relocated to the end of the decompression area. > > This allows to setup different IDT handlers before and after the > relocation. > > Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> > --- > diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S > index 1f1f6c8139b3..d27a9ce1bcb0 100644 > --- a/arch/x86/boot/compressed/head_64.S > +++ b/arch/x86/boot/compressed/head_64.S > @@ -465,6 +470,16 @@ SYM_FUNC_END_ALIAS(efi_stub_entry) > .text > SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) > > +/* > + * Reload GDT after relocation - The GDT at the non-relocated position > + * might be overwritten soon by the in-place decompression, so reload > + * GDT at the relocated address. The GDT is referenced by exception > + * handling and needs to be set up correctly. > + */ > + leaq gdt(%rip), %rax > + movq %rax, gdt64+2(%rip) > + lgdt gdt64(%rip) > + > /* > * Clear BSS (stack is currently empty) > */ Note that this is now done in mainline as of commit c98a76eabbb6e, just prior to jumping to .Lrelocated, so this can be dropped on the next rebase. Thanks.
