Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1311828 > unrolled thread

Re: [PATCH 1/2] x86/kasan: clear kasan_zero_page after TLB flush

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [PATCH 1/2] x86/kasan: clear kasan_zero_page after TLB flush Andy Lutomirski <luto@amacapital.net> - 2016-01-18 23:30 +0100

#1311828 — Re: [PATCH 1/2] x86/kasan: clear kasan_zero_page after TLB flush

On Mon, Jan 11, 2016 at 4:51 AM, Andrey Ryabinin
<aryabinin@virtuozzo.com> wrote:
> Currently we clear kasan_zero_page before __flush_tlb_all(). This
> works with current implementation of native_flush_tlb[_global]()
> because it doesn't cause do any writes to kasan shadow memory.
> But any subtle change made in native_flush_tlb*() could break this.
> Also current code seems doesn't work for paravirt guests (lguest).
>
> Only after the TLB flush we can be sure that kasan_zero_page is not
> used as early shadow anymore (instrumented code will not write to it).
> So it should cleared it only after the TLB flush.

This seems to fix the issue with my patch set.  Thanks.

Tested-by: Andy Lutomirski <luto@kernel.org>

--Andy

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web