Re: [PATCH v2 0/5] x86/kasan: Bug fixes for recent CEA changes

From: Peter Zijlstra
Date: Mon Nov 14 2022 - 07:01:02 EST


On Thu, Nov 10, 2022 at 08:34:59PM +0000, Sean Christopherson wrote:
> Three fixes for the recent changes to how KASAN populates shadows for
> the per-CPU portion of the CPU entry areas. The v1 versions were posted
> independently as I kept root causing issues after posting individual fixes.
>
> v2:
> - Map the entire per-CPU area in one shot. [Andrey]
> - Use the "early", i.e. read-only, variant to populate the shadow for
> the shared portion (read-only IDT mapping) of the CEA. [Andrey]
>
> v1:
> - https://lore.kernel.org/all/20221104212433.1339826-1-seanjc@xxxxxxxxxx
> - https://lore.kernel.org/all/20221104220053.1702977-1-seanjc@xxxxxxxxxx
> - https://lore.kernel.org/all/20221104183247.834988-1-seanjc@xxxxxxxxxx
>
> Sean Christopherson (5):
> x86/mm: Recompute physical address for every page of per-CPU CEA
> mapping
> x86/mm: Populate KASAN shadow for entire per-CPU range of CPU entry
> area
> x86/kasan: Rename local CPU_ENTRY_AREA variables to shorten names
> x86/kasan: Add helpers to align shadow addresses up and down
> x86/kasan: Populate shadow for shared chunk of the CPU entry area
>
> arch/x86/mm/cpu_entry_area.c | 10 +++-----
> arch/x86/mm/kasan_init_64.c | 50 +++++++++++++++++++++++-------------
> 2 files changed, 36 insertions(+), 24 deletions(-)

Thanks for cleaning up that mess!