On Fri, Nov 10, 2017 at 10:12:36AM +0100, Ingo Molnar wrote:
>
> * Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
>
> > We are going to put few helpers into pagetable.c that are not specific
> > to KASLR.
> >
> > Let's make compilation of the file independent of KASLR and wrap
> > KASLR-depended code into ifdef.
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> > ---
> > arch/x86/boot/compressed/Makefile | 2 +-
> > arch/x86/boot/compressed/pagetable.c | 5 +++++
> > 2 files changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
> > index 65a150a7f15c..f7b64ecd09b3 100644
> > --- a/arch/x86/boot/compressed/Makefile
> > +++ b/arch/x86/boot/compressed/Makefile
> > @@ -77,7 +77,7 @@ vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/head_$(BITS).o $(obj)/misc.o \
> > vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
> > vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
> > ifdef CONFIG_X86_64
> > - vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/pagetable.o
> > + vmlinux-objs-y += $(obj)/pagetable.o
> > endif
> >
> > $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
> > diff --git a/arch/x86/boot/compressed/pagetable.c b/arch/x86/boot/compressed/pagetable.c
> > index f1aa43854bed..a15bbfcb3413 100644
> > --- a/arch/x86/boot/compressed/pagetable.c
> > +++ b/arch/x86/boot/compressed/pagetable.c
> > @@ -27,6 +27,9 @@
> > /* These actually do the work of building the kernel identity maps. */
> > #include <asm/init.h>
> > #include <asm/pgtable.h>
> > +
> > +#ifdef CONFIG_RANDOMIZE_BASE
> > +
> > /* Use the static base for this part of the boot process */
> > #undef __PAGE_OFFSET
> > #define __PAGE_OFFSET __PAGE_OFFSET_BASE
> > @@ -149,3 +152,5 @@ void finalize_identity_maps(void)
> > {
> > write_cr3(top_level_pgt);
> > }
> > +
> > +#endif /* CONFIG_RANDOMIZE_BASE */
>
> The #ifdeffery becomes really ugly in this file. I think we should split these
> into separate .c files:
>
> arch/x86/boot/compressed/kaslr.c
> arch/x86/boot/compressed/5-level-paging.c
>
> With core data structures and code and a well defined interface:
>
> arch/x86/boot/compressed/pagetable.c
> arch/x86/boot/compressed/pagetable.h
>
> or so.
Okay, I'll do this.
--
Kirill A. Shutemov
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