Re: [PATCH v8 0/2] x86/boot/KASLR: Restrict kernel to be randomized in mirror regions

Baoquan He
2017-08-04T09:22:45Z

On 08/04/17 at 03:52pm, Baoquan He wrote:
> Sorry, NACK this series, there's error to hang system. Before I just
> halt system intentionally with error() to check the efi memmap printing,
> didn't notice this. Checking the cause.

I rebuilt the code or change the one of the replacement back, hang never
seen again. Not sure if I copied the wrong kernel or any other mistakes.
Have got a hardware system with efi enabled to try again, see if
anything wrong will happen. It's really weird. And Chao also is helping
to try on his side.

>
> On 08/04/17 at 03:26pm, Baoquan He wrote:
> > Patch 1/2 is newly added to add efi_memdesc_ptr helper to wrap the
> > open code which gets the start of efi memmap descriptor and also
> > explain why it need be done like that, Ingo suggested it.
> >
> > And also replace several places of the open code with efi_memdesc_ptr
> > helper.
> >
> > And also use efi_memdesc_ptr in process_efi_entries() which handle efi
> > mirror issue during KASLR.
> >
> >
> > Change:
> > v7->v8:
> > Add efi_memdesc_ptr helper to wrap the open code which gets the
> > start of map descriptor according to Ingo's suggestion.
> >
> > v6->v7:
> > Ingo pointed out several incorrect line break issues and unclear
> > description of patch log. Correct them and rewrite patch log.
> >
> > And also rewrite the EFI warning message that if EFI memmap is above
> > 4G in 32bit system since 32bit system can not handle data above 4G at
> > kernel decompression stage. This is suggested by Ingo too.
> >
> > v5->v6:
> > Code style issue fix according to Kees's comment.
> >
> > This is based on tip/x86/boot, patch 1,2,3/4 in v5 post has
> > been put into tip/x86/boot now.
> >
> >
> >
> > Baoquan He (2):
> > efi: Introduce efi_memdesc_ptr to get pointer to memmap descriptor
> > x86/boot/KASLR: Restrict kernel to be randomized in mirror regions
> >
> > arch/x86/boot/compressed/eboot.c | 2 +-
> > arch/x86/boot/compressed/kaslr.c | 68 +++++++++++++++++++++++++-
> > drivers/firmware/efi/libstub/efi-stub-helper.c | 4 +-
> > include/linux/efi.h | 19 +++++++
> > 4 files changed, 88 insertions(+), 5 deletions(-)
> >
> > --
> > 2.5.5
> >